WorldWideScience

Sample records for solid reaction products

  1. Gas-Solid Reaction Route toward the Production of Intermetallics from Their Corresponding Oxide Mixtures

    Directory of Open Access Journals (Sweden)

    Hesham Ahmed

    2016-08-01

    Full Text Available Near-net shape forming of metallic components from metallic powders produced in situ from reduction of corresponding pure metal oxides has not been explored to a large extent. Such a process can be probably termed in short as the “Reduction-Sintering” process. This methodology can be especially effective in producing components containing refractory metals. Additionally, in situ production of metallic powder from complex oxides containing more than one metallic element may result in in situ alloying during reduction, possibly at lower temperatures. With this motivation, in situ reduction of complex oxides mixtures containing more than one metallic element has been investigated intensively over a period of years in the department of materials science, KTH, Sweden. This review highlights the most important features of that investigation. The investigation includes not only synthesis of intermetallics and refractory metals using the gas solid reaction route but also study the reaction kinetics and mechanism. Environmentally friendly gases like H2, CH4 and N2 were used for simultaneous reduction, carburization and nitridation, respectively. Different techniques have been utilized. A thermogravimetric analyzer was used to accurately control the process conditions and obtain reaction kinetics. The fluidized bed technique has been utilized to study the possibility of bulk production of intermetallics compared to milligrams in TGA. Carburization and nitridation of nascent formed intermetallics were successfully carried out. A novel method based on material thermal property was explored to track the reaction progress and estimate the reaction kinetics. This method implies the dynamic measure of thermal diffusivity using laser flash method. These efforts end up with a successful preparation of nanograined intermetallics like Fe-Mo and Ni-W. In addition, it ends up with simultaneous reduction and synthesis of Ni-WN and Ni-WC from their oxide mixtures

  2. Mathematical modeling of the coupled transport and electrochemical reactions in solid oxide steam electrolyzer for hydrogen production

    International Nuclear Information System (INIS)

    Ni, Meng; Leung, Michael K.H.; Leung, Dennis Y.C.

    2007-01-01

    A mathematical model was developed to simulate the coupled transport/electrochemical reaction phenomena in a solid oxide steam electrolyzer (SOSE) at the micro-scale level. Ohm's law, dusty gas model (DGM), Darcy's law, and the generalized Butler Volmer equation were employed to determine the transport of electronic/ionic charges and gas species as well as the electrochemical reactions. Parametric analyses were performed to investigate the effects of operating parameters and micro-structural parameters on SOSE potential. The results substantiated the fact that SOSE potential could be effectively decreased by increasing the operating temperature. In addition, higher steam molar fraction would enhance the operation of SOSE with lower potential. The effect of particle sizes on SOSE potential was studied with due consideration on the SOSE activation and concentration overpotentials. Optimal particle sizes that could minimize the SOSE potential were obtained. It was also found that decreasing electrode porosity could monotonically decrease the SOSE potential. Besides, optimal values of volumetric fraction of electronic particles were found to minimize electrode total overpotentials. In order to optimize electrode microstructure to minimize SOSE electricity consumption, the concept of 'functionally graded materials (FGM)' was introduced to lower the SOSE potential. The advanced design of particle size graded SOSE was found effective for minimizing electrical energy consumption resulting in efficient SOSE hydrogen production. The micro-scale model was capable of predicting SOSE hydrogen production performance and would be a useful tool for design optimization

  3. Solid-Phase Iminium Cyclization Reactions for the Synthesis of Natural Product-Like Diketopiperazines

    DEFF Research Database (Denmark)

    Petersen, Rico

    The development of methodology for the solid-phase synthesis of fused 2,5-diketopiperazines with an emphasis on structural and stereochemical control, has been accomplished through two different approaches. The first approach was based on a highly trans-stereoselective (82% d.e.) intramolecular N...... inhibitors based on the 2,5-diketopiperazino[6,1-a]tetrahydroisoquinoline scaffold was prepared and subsequently evaluated for biologically activity. The compounds showed inhibitory activity against a nuclear extract of HeLa cells, on average 200-fold lower than the activity of SAHA. When screened towards...... HDAC 1 the compounds showed a lower inhibitor activity, compared to the nuclear extract, except for one of the compounds which showed increased activity. The compound represents a clear case of stereodifferentiation. Finally, and most importantly, when screening the compounds towards HDAC 8 an activity...

  4. Applications of solid-state nuclear track detectors (SSNTDs) for fast ion and fusion reaction product measurements in TEXTOR experiments

    Energy Technology Data Exchange (ETDEWEB)

    Szydlowski, A.; Malinowski, K.; Malinowska, A. [Association EURTOM-IPPLM Warsaw, The Andrzej Soltan Institute for Nuclear Studies, 05-400 Otwock-Swierk (Poland); Wassenhove, G. Van [EURATOM-Belgium State Association, LPP, ERM/KMS, Trilateral Euregio Cluster, B-1000 Brussels (Belgium); Schweer, B. [Association EURATOM-FZJ, Institutte of Plasma Physicx, Juelich (Germany)

    2011-07-01

    Full text of publication follows: The paper reports on measurements of fusion reaction protons which were performed on TEXTOR facility in January 2009. The basic experimental scheme was similar to that applied in the previous measurements [1, 2]. The main experimental tool equipment was a small ion pinhole camera which was equipped with a PM-355 detector sample and was attached to a water cooled manipulator. The camera was placed below the plasma ring in the direction of ion drifts, at a distance of 4.4 cm from LCFS. However, in the described experiment it was aligned at an angle to the mayor TEXTOR radius (contrary to previous experiments), so that the input pinhole was oriented first at {gamma} = 45 degrees (shots 108799 - 108818) and then {gamma} = 600 (shots 108832 - 108847). The discharges were executed with one neutral beam of the total power 0.6 - 1.0 MW. In the first series (Nos 108799 - 108818) the plasma was additionally heated by ICRH of frequency 38 MHz. The irradiated detector samples were subjected to the same interrupted etching procedure as the samples used in the CR-39/PM-355 detector calibration measurements [1, 2]. After that, track density distributions and track diameter histograms were measured under an optical microscope. By the use of the calibration curves, it was possible to distinguish craters produced by protons from other craters and to convert the obtained histograms into proton energy spectra. The craters induced by lower energy ions appeared to be concentrated in narrower areas, whereas higher energy ions were registered in a more diffused detector fields. The paper shows again that the CR-39/PM-355 detector is an useful diagnostic tool for tokamak experiments, for measurement of charged ions. References: [1] A. Szydlowski, A. Malinowska, M. Jaskola, A. Korman, M.J. Sadowski, G. Van Wassenhove, B. Schweer and the TEXTOR team, A. Galkowski, 'Application of Solid State Nuclear Track Detectors in TEXTOR Experiment for Measurements

  5. Chemical reaction on solid surface observed through isotope tracer technique

    International Nuclear Information System (INIS)

    Tanaka, Ken-ichi

    1983-01-01

    In order to know the role of atoms and ions on solid surfaces as the partners participating in elementary processes, the literatures related to the isomerization and hydrogen exchanging reaction of olefines, the hydrogenation of olefines, the metathesis reaction and homologation of olefines based on solid catalysts were reviewed. Various olefines, of which the hydrogen atoms were substituted with deuterium at desired positions, were reacted using various solid catalysts such as ZnO, K 2 CO 3 on C, MoS 2 (single crystal and powder) and molybdenum oxide (with various carriers), and the infra-red spectra of adsorbed olefines on catalysts, the isotope composition of reaction products and the production rate of the reaction products were measured. From the results, the bonding mode of reactant with the atoms and ions on solid surfaces, and the mechanism of the elementary process were considered. The author emphasized that the mechanism of the chemical reaction on solid surfaces and the role of active points or catalysts can be made clear to the considerable extent by combining isotopes suitably. (Yoshitake, I.)

  6. Analytical electron microscopy examination of solid reaction products in long-term test of SRL 200 waste glasses

    International Nuclear Information System (INIS)

    Buck, E.C.; Fortner, J.A.; Bates, J.K.; Feng, X.; Dietz, N.L.; Bradley, C.R.; Tani, B.S.

    1993-01-01

    Alteration phases, found on the leached surfaces and present as colloids in the leachates of 200-based frit (fully active and simulated) nuclear waste glass, reacted under static test conditions, at a surface area to leachate volume ratio of 20,000 m -1 for 15 days to 728 days, have been examined by analytical electron microscopy. The compositions of the secondary phases were determined using x-ray energy dispersive spectroscopy and electron energy loss spectroscopy, and structural analysis was accomplished by electron diffraction. Long-term samples of simulated glass, which had undergone an acceleration of reaction after 182 days, possessed a number of silicate secondary phases, including; smectite (iron silicate and potassium iron alumina-silicate, weeksite (uranium silicate), zeolite (calcium potassium alumino-silicate), tobermorite (calcium silicate), and a pure silica phase. However, uranium silicates and smectite have also been observed in tests, which have not undergone the acceleration of reaction, in both the leachate and leached layer, suggesting that these phases are not responsible for the acceleration of reaction

  7. The abundant excess heat production during low energy nuclear reaction in the nano scale solid state the cold fusion, 14 years' legacy

    International Nuclear Information System (INIS)

    Woo, Tae Ho; Miley, George H.; Lipson, Andrei; Kim, Sung O.; Luo, Nie; Castano, Carlos H.

    2002-01-01

    The quite abundant excess heat and radioactive materials are found during the solid state reaction. This phenomenon has done during the Low Energy Nuclear Reaction (LENR) in the nano scale molecular structure electrodes and Hydrogen compound electrolytes. The Palladium (or Nickel) and Platinum are incorporated as the electrode and the Light Water (H 2 O) as the electrolyte. The excess heat was produced up to 40% in year 2001. The Alpha particles are also detected. The computer code, Coherent Lattice Accelerator Inter-Ionic Reaction Enhancer (CLAIRE) Code System, is constructed for the simulation. The 0.1 A of the distance between two the Hydrogen ion (proton) and Palladium nucleus is the critical point for the nuclear fusion reaction

  8. The abundant excess heat production during low energy nuclear reaction in the nano scale solid state the cold fusion, 14 years' legacy

    Energy Technology Data Exchange (ETDEWEB)

    Woo, Tae Ho; Miley, George H.; Lipson, Andrei; Kim, Sung O.; Luo, Nie; Castano, Carlos H. [The University of Illinois, Urbana (United States)

    2002-05-01

    The quite abundant excess heat and radioactive materials are found during the solid state reaction. This phenomenon has done during the Low Energy Nuclear Reaction (LENR) in the nano scale molecular structure electrodes and Hydrogen compound electrolytes. The Palladium (or Nickel) and Platinum are incorporated as the electrode and the Light Water (H{sub 2}O) as the electrolyte. The excess heat was produced up to 40% in year 2001. The Alpha particles are also detected. The computer code, Coherent Lattice Accelerator Inter-Ionic Reaction Enhancer (CLAIRE) Code System, is constructed for the simulation. The 0.1 A of the distance between two the Hydrogen ion (proton) and Palladium nucleus is the critical point for the nuclear fusion reaction.

  9. Extraction products of solid carbonaceous materials

    Energy Technology Data Exchange (ETDEWEB)

    1937-11-04

    A method is described for the manufacture of liquid products from pressure extracts of solid carbon-containing material by destructive hydrogenation, characterized in that the pressure extracts are hydrogenated in admixture with products of high-molecular weight formed during a previous destructive hydrogenation of another part of the same or other pressure extract and which has been collected as liquid without extensive cooling of the hot products of the reaction, which came from the reaction chamber where the previous destructive hydrogenation took place.

  10. Reaction product imaging

    Energy Technology Data Exchange (ETDEWEB)

    Chandler, D.W. [Sandia National Laboratories, Livermore, CA (United States)

    1993-12-01

    Over the past few years the author has investigated the photochemistry of small molecules using the photofragment imaging technique. Bond energies, spectroscopy of radicals, dissociation dynamics and branching ratios are examples of information obtained by this technique. Along with extending the technique to the study of bimolecular reactions, efforts to make the technique as quantitative as possible have been the focus of the research effort. To this end, the author has measured the bond energy of the C-H bond in acetylene, branching ratios in the dissociation of HI, the energetics of CH{sub 3}Br, CD{sub 3}Br, C{sub 2}H{sub 5}Br and C{sub 2}H{sub 5}OBr dissociation, and the alignment of the CD{sub 3} fragment from CD{sub 3}I photolysis. In an effort to extend the technique to bimolecular reactions the author has studied the reaction of H with HI and the isotopic exchange reaction between H and D{sub 2}.

  11. Reactions of uranium hexafluoride photolysis products

    Science.gov (United States)

    Lyman, John L.; Laguna, Glenn; Greiner, N. R.

    1985-01-01

    This paper confirms that the ultraviolet photolysis reactions of UF6 in the B band spectral region is simple bond cleavage to UF5 and F. The photolysis products may either recombine to UF6 or the UF5 may dimerize, and ultimately polymerize, to solid UF5 particles. We use four methods to set an upper limit for the rate constant for recombination of krUF6 and UF5 after laser photolysis of the UF6 gas sample.

  12. Gas to liquid to solid transition in halogen hot atom chemistry. 6. Product formation routes and chemical selectivity of high energy iodine reactions with butyne isomers

    International Nuclear Information System (INIS)

    Garmestani, S.K.; Firouzbakht, M.L.; Rack, E.P.

    1979-01-01

    Reactions of recoil produced iodine-128 with isomers of butyne were studied in gaseous, high pressure, and condensed phase conditions, with rare gas additives and in the presence and absence of radical scavengers (I 2 and O 2 ). It was found that recoil iodine-128 reactions were initiated by thermal electronically excited I + species for both 1-butyne and 2-butyne systems. While the diverse and complex nature of the reactions cannot be explained by simple chemical parameters, comparisons among the alkyne systems demonstrate preferential attack of iodine at the triple bond resulting, mainly, in electronically excited intermediates. A comparison of the various product formation routes results in the characterization of general traits common to the alkynes. 6 figures, 4 tables

  13. Diffusion limited reactions in crystalline solids

    International Nuclear Information System (INIS)

    Fastenau, R.

    1982-01-01

    Diffusion limited reactions in crystal lattices are studied with diffusion and random walk theory. First the random walk on a crystal lattice is studied. These results are used in a formal study of diffusion limited reactions in which the following simplified traps are discussed: planes, cylinders, spheres, disks and rings. The traps are either present at the start of the process (annealing) or fed into the crystal at a constant rate (continuous production). For the study of trapping processes occurring in real crystals it was necessary to investigate the interaction of the reacting species on the atomic level. Using lattice relaxation calculations, several reactions were studied. These calculations result in a model for the potential energy of the crystal versus the separation of the reaction partners. This model is used in Monte Carlo simulations of the trapping process, which are made at a high trap density, since the extrapolation to the low density regime can be made using the formal part of this work. The following reactions were studied: the trapping of interstitial helium atoms by vacancies, self interstitial vacancy recombination, the trapping of vacancies by immobile, helium filled, vacancies and the capture of self interstitials and vacancies by dislocations. A part of these results is used in two models for the low temperature nucleation and growth of bubbles due to helium bombardment. The models described give the right bubble density versus helium dose, but differ widely in the fraction of helium present in the bubbles found. A mechanism of blistering based on a percolation effect is also discussed. (Auth.)

  14. Chemical degradation of proteins in the solid state with a focus on photochemical reactions.

    Science.gov (United States)

    Mozziconacci, Olivier; Schöneich, Christian

    2015-10-01

    Protein pharmaceuticals comprise an increasing fraction of marketed products but the limited solution stability of proteins requires considerable research effort to prepare stable formulations. An alternative is solid formulation, as proteins in the solid state are thermodynamically less susceptible to degradation. Nevertheless, within the time of storage a large panel of kinetically controlled degradation reactions can occur such as, e.g., hydrolysis reactions, the formation of diketopiperazine, condensation and aggregation reactions. These mechanisms of degradation in protein solids are relatively well covered by the literature. Considerably less is known about oxidative and photochemical reactions of solid proteins. This review will provide an overview over photolytic and non-photolytic degradation reactions, and specially emphasize mechanistic details on how solid structure may affect the interaction of protein solids with light. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Method for reactivating solid catalysts used in alkylation reactions

    Science.gov (United States)

    Ginosar, Daniel M.; Thompson, David N.; Coates, Kyle; Zalewski, David J.; Fox, Robert V.

    2003-06-17

    A method for reactivating a solid alkylation catalyst is provided which can be performed within a reactor that contains the alkylation catalyst or outside the reactor. Effective catalyst reactivation is achieved whether the catalyst is completely deactivated or partially deactivated. A fluid reactivating agent is employed to dissolve catalyst fouling agents and also to react with such agents and carry away the reaction products. The deactivated catalyst is contacted with the fluid reactivating agent under pressure and temperature conditions such that the fluid reactivating agent is dense enough to effectively dissolve the fouling agents and any reaction products of the fouling agents and the reactivating agent. Useful pressures and temperatures for reactivation include near-critical, critical, and supercritical pressures and temperatures for the reactivating agent. The fluid reactivating agent can include, for example, a branched paraffin containing at least one tertiary carbon atom, or a compound that can be isomerized to a molecule containing at least one tertiary carbon atom.

  16. Nanocrystalline spinel ferrites by solid state reaction route

    Indian Academy of Sciences (India)

    Wintec

    Nanocrystalline spinel ferrites by solid state reaction route. T K KUNDU* and S MISHRA. Department of Physics, Visva-Bharati, Santiniketan 731 235, India. Abstract. Nanostructured NiFe2O4, MnFe2O4 and (NiZn)Fe2O4 were synthesized by aliovalent ion doping using conventional solid-state reaction route. With the ...

  17. Solid-state reactions to synthesize nanostructured lead selenide semiconductor powders by high-energy milling

    Energy Technology Data Exchange (ETDEWEB)

    Rojas-Chavez, H., E-mail: uu_gg_oo@yahoo.com.mx [Centro de Investigacion e Innovacion Tecnologica - IPN, Cerrada de CECATI s/n, Col. Santa Catarina, Del. Azcapotzalco (Mexico) and Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada - IPN, Legaria 694, Col. Irrigacion, Del. Miguel Hidalgo (Mexico); Reyes-Carmona, F. [Facultad de Quimica - UNAM, Circuito de la Investigacion Cientifica s/n, C.U. Del. Coyoacan (Mexico); Jaramillo-Vigueras, D. [Centro de Investigacion e Innovacion Tecnologica - IPN, Cerrada de CECATI s/n, Col. Santa Catarina, Del. Azcapotzalco (Mexico)

    2011-10-15

    Highlights: {yields} PbSe synthesized from PbO instead of Pb powder do not require an inert atmosphere. {yields} During high-energy milling oxygen has to be chemically reduced from the lead oxide. {yields} Solid-state and solid-gas chemical reactions promote both solid and gaseous products. -- Abstract: Both solid-solid and gas-solid reactions have been traced during high-energy milling of Se and PbO powders under vial (P, T) conditions in order to synthesize the PbSe phase. Chemical and thermodynamic arguments are postulated to discern the high-energy milling mechanism to transform PbO-Se micropowders onto PbSe-nanocrystals. A set of reactions were evaluated at around room temperature. Therefore an experimental campaign was designed to test the nature of reactions in the PbO-Se system during high-energy milling.

  18. Solid-state reactions to synthesize nanostructured lead selenide semiconductor powders by high-energy milling

    International Nuclear Information System (INIS)

    Rojas-Chavez, H.; Reyes-Carmona, F.; Jaramillo-Vigueras, D.

    2011-01-01

    Highlights: → PbSe synthesized from PbO instead of Pb powder do not require an inert atmosphere. → During high-energy milling oxygen has to be chemically reduced from the lead oxide. → Solid-state and solid-gas chemical reactions promote both solid and gaseous products. -- Abstract: Both solid-solid and gas-solid reactions have been traced during high-energy milling of Se and PbO powders under vial (P, T) conditions in order to synthesize the PbSe phase. Chemical and thermodynamic arguments are postulated to discern the high-energy milling mechanism to transform PbO-Se micropowders onto PbSe-nanocrystals. A set of reactions were evaluated at around room temperature. Therefore an experimental campaign was designed to test the nature of reactions in the PbO-Se system during high-energy milling.

  19. Transport processes in exothermic gas-solid reactions

    International Nuclear Information System (INIS)

    Vijay, P.L.; Sathiyamoorthy, D.

    1997-01-01

    The variation of the concentration of gaseous reactant, temperature distribution for an exothermic reaction, the diffusivity factor and the reaction ratio profiles with various radial positions of a solid reactant have been computed and illustrated for a specific case of reduction reaction of UO 3 by hydrogen

  20. Electron transfer reactions in microporous solids

    Energy Technology Data Exchange (ETDEWEB)

    Mallouk, T.E.

    1993-01-01

    Basic thrust the research program involves use of microporous solids (zeolites, clays, layered and tunnel structure oxide semiconductors) as organizing media for artificial photosynthetic systems. Purpose of the microporous solid is twofold. First, it induces spatial organization of photoactive and electroactive components (sensitizers, semiconductor particles, electron relays, and catalysts) at the solid-solution interface, enhancing the quantum efficiency of charge separation and separating physically the ultimate electron donor and acceptor in the electron transport chain. Second, since the microcrystalline solid admits only molecules of a certain charge and size, it is possible to achieve permanent charge separation by sieving chemical photoproducts (e.g., H[sub 2] and I[sub 3][sup [minus

  1. The reductive decomposition of calcium sulphate I. Kinetics of the apparent solid-solid reaction

    NARCIS (Netherlands)

    Kamphuis, B.; Potma, A.W.; Prins, W.; van Swaaij, Willibrordus Petrus Maria

    1992-01-01

    The reductive decomposition of calcium sulphate by hydrogen is used for the regeneration of calcium-based atmospheric fluidized bed combustion (AFBC) SO2 sorbents. The apparent solid¿solid reaction between CaS and CaSO4, one of the steps involved in the reaction mechanism of the reductive

  2. A miniature CSTR cascade for continuous flow of reactions containing solids

    OpenAIRE

    Mo, Yiming; Jensen, Klavs F

    2016-01-01

    Continuous handling of solids creates challenges for realizing continuous production of pharmaceuticals and fine chemicals. We present a new miniature continuous stirred-tank reactor (CSTR) cascade to handle solid-forming reactions in flow. Single-phase residence time distribution (RTD) measurements of the CSTR cascade reveal nearly ideal CSTR mixing behavior of the individual units. Consistency of experimental and predicted conversions of a Diels–Alder reaction further confirms the CSTR perf...

  3. Simultaneous formation and detection of the reaction product of solid-state aspartame sweetener by FT-IR/DSC microscopic system.

    Science.gov (United States)

    Lin, S Y; Cheng, Y D

    2000-10-01

    The solid-state stability of aspartame hemihydrate (APM) sweetener during thermal treatment is important information for the food industry. The present study uses the novel technique of Fourier transform infrared microspectroscopy equipped with differential scanning calorimetry (FT-IR/DSC microscopic system) to accelerate and determine simultaneously the thermal-dependent impurity formation of solid-state APM. The results indicate a dramatic change in IR spectra from 50, 110 or 153 degrees C, which was respectively attributed to the onset temperature of water evaporation, dehydration and cyclization processes. It is suggested that the processes of dehydration and intramolecular cyclization occurred in the solid-state APM during the heating process. As an impurity, 3-carboxymethyl-6-benzyl-2,5-diketopiperazine (DKP) degraded from solid state APM via intramolecular cyclization and liberation of methanol. This was evidenced by this novel FT-IR/DSC microscopic system in a one-step procedure.

  4. Isotope exchange reaction on solid breeder materials

    International Nuclear Information System (INIS)

    Baba, A.; Nishikawa, M.; Eguchi, T.; Kawagoe, T.

    2000-01-01

    Lithium ceramic materials such as Li 2 O, LiAlO 2 , Li 2 ZrO 3 , Li 2 TiO 3 and Li 4 SiO 4 are considered to be as candidate for the tritium breeding material in a deuterium-tritium (D-T) fusion reactor. In the recent blanket designs, helium gas with hydrogen or deuterium is planned to be used as the blanket purge gas to reduce tritium inventory and promote tritium release from the breeding material. In addition, the rate of isotope exchange reaction between hydrogen isotopes in the purge gas and tritium on the surface of the breeding material is necessary to analyze the tritium release behavior from the breeding materials. However, the rate of isotope exchange reactions between hydrogen isotopes in the purge gas and tritium on the surface of those materials has not been quantified until recently. Recently, the present authors quantified the rate of isotope exchange reaction on Li 2 O and Li 2 ZrO 3 . The overall mass transfer coefficients representing the isotope exchange reaction between H 2 and D 2 O on breeding materials or the same between D 2 and H 2 O are experimentally obtained in this study. Comparison to isotope exchange reaction rates on various breeding materials is also performed in this study. Discussions about the effects of temperature, concentration of hydrogen in the purge gas or flow rate of the purge gas on the conversion of tritiated water to tritium gas are also performed

  5. Reaction diffusion and solid state chemical kinetics handbook

    CERN Document Server

    Dybkov, V I

    2010-01-01

    This monograph deals with a physico-chemical approach to the problem of the solid-state growth of chemical compound layers and reaction-diffusion in binary heterogeneous systems formed by two solids; as well as a solid with a liquid or a gas. It is explained why the number of compound layers growing at the interface between the original phases is usually much lower than the number of chemical compounds in the phase diagram of a given binary system. For example, of the eight intermetallic compounds which exist in the aluminium-zirconium binary system, only ZrAl3 was found to grow as a separate

  6. Contribution to the modelling of gas-solid reactions and reactors; Contribution a la modelisation des reactions et des reacteurs gaz-solide

    Energy Technology Data Exchange (ETDEWEB)

    Patisson, F

    2005-09-15

    Gas-solid reactions control a great number of major industrial processes involving matter transformation. This dissertation aims at showing that mathematical modelling is a useful tool for both understanding phenomena and optimising processes. First, the physical processes associated with a gas-solid reaction are presented in detail for a single particle, together with the corresponding available kinetic grain models. A second part is devoted to the modelling of multiparticle reactors. Different approaches, notably for coupling grain models and reactor models, are illustrated through various case studies: coal pyrolysis in a rotary kiln, production of uranium tetrafluoride in a moving bed furnace, on-grate incineration of municipal solid wastes, thermogravimetric apparatus, nuclear fuel making, steel-making electric arc furnace. (author)

  7. Catalytic and Gas-Solid Reactions Involving HCN over Limestone

    DEFF Research Database (Denmark)

    Jensen, Anker; Johnsson, Jan Erik; Dam-Johansen, Kim

    1997-01-01

    In coal-fired combustion systems solid calcium species may be present as ash components or limestone added to the combustion chamber. In this study heterogeneous reactions involving HCN over seven different limestones were investigated in a laboratory fixed-bed quartz reactor at 873-1,173 K...

  8. Kinetic concepts of thermally stimulated reactions in solids

    Science.gov (United States)

    Vyazovkin, Sergey

    Historical analysis suggests that the basic kinetic concepts of reactions in solids were inherited from homogeneous kinetics. These concepts rest upon the assumption of a single-step reaction that disagrees with the multiple-step nature of solid-state processes. The inadequate concepts inspire such unjustified anticipations of kinetic analysis as evaluating constant activation energy and/or deriving a single-step reaction mechanism for the overall process. A more adequate concept is that of the effective activation energy, which may vary with temperature and extent of conversion. The adequacy of this concept is illustrated by literature data as well as by experimental data on the thermal dehydration of calcium oxalate monohydrate and thermal decomposition of calcium carbonate, ammonium nitrate and 1,3,5,7- tetranitro-1,3,5,7-tetrazocine.

  9. Ambient Mechanochemical Solid-State Reactions of Carbon Nanotubes and Their Reactions via Covalent Coordinate Bond in Solution

    Science.gov (United States)

    Kabbani, Mohamad A.

    In its first part, this thesis deals with ambient mechanochemical solid-state reactions of differently functionalized multiple walled carbon nanotubes (MWCNTs) while in its second part it investigates the cross-linking reactions of CNTs in solution via covalent coordinate bonds with transitions metals and carboxylate groups decorating their surfaces. In the first part a series of mechanochemical reactions involving different reactive functionalities on the CNTs such as COOH/OH, COOH/NH2 and COCl/OH were performed. The solid-state unzipping of CNTs leading to graphene formation was confirmed using spectroscopic, thermal and electron microscopy techniques. The non-grapheme products were established using in-situ quadruple mass spectroscopy. The experimental results were confirmed by theoretical simulation calculations using the 'hot spots' protocol. The kinetics of the reaction between MWCNT-COOH and MWCNT-OH was monitored using variable temperature Raman spectroscopy. The low activation energy was discussed in terms of hydrogen bond mediated proton transfer mechanism. The second part involves the reaction of MWCNTII COOH with Zn (II) and Cu (II) to form CNT metal-organic frame (MOFs) products that were tested for their effective use as counter-electrodes in dyes sensitized solar cells (DSSC). The thesis concludes by the study of the room temperature reaction between the functionalized graphenes, GOH and G'-COOH followed by the application of compressive loads. The 3D solid graphene pellet product ( 0.6gm/cc) is conductive and reflective with a 35MPa ultimate strength as compared to 10MPa strength of graphite electrode ( 2.2gm/cc).

  10. Solid-phase vibrational redox reactions in coordinated oxides

    International Nuclear Information System (INIS)

    Kostikova, G.P.; Korol'kov, D.V.; Kostikov, Yu.P.

    1996-01-01

    The properties of multicomponent oxides (YBa 2 Cu 3 O 7-x , etc.), incorporating different valency forms of each of two (or more) different elements have been compared with the properties of the known chemical systems, where vibrational (periodic) redox-reactions are realized a fortiori. The essence of the new theoretical concept suggested consists in the following: high-T c superconductivity of the complex oxides and similar compounds originates from vibrational redox reaction proceeding in solid phase and involving different valency atoms of every element

  11. Workshop Report: Fundamental Reactions in Solid Propellant Combustion

    Science.gov (United States)

    1979-05-01

    combustion conditions. 6. What effect might a pressure-induced phase transition to a polymorph other than 6- HMX have on the pressure slope break during...pure HMX as well. Nevertheless, it is recommended that the high pressure polymorphs of HMX and RDX be determined. It was also felt that there...plateau burning phenomena E. Solid phase, surface, gas phase reactions F. Phase transitions : melting, vaporization, polymorphs G. Flame

  12. Electron stimulated reactions of methyl iodide coadsorbed with amorphous solid water

    International Nuclear Information System (INIS)

    Perry, C. C.; Faradzhev, N. S.; Madey, T. E.; Fairbrother, D. H.

    2007-01-01

    The electron stimulated reactions of methyl iodide (MeI) adsorbed on and suspended within amorphous solid water (ice) were studied using a combination of postirradiation temperature programmed desorption and reflection absorption infrared spectroscopy. For MeI adsorbed on top of amorphous solid water (ice), electron beam irradiation is responsible for both structural and chemical transformations within the overlayer. Electron stimulated reactions of MeI result principally in the formation of methyl radicals and solvated iodide anions. The cross section for electron stimulated decomposition of MeI is comparable to the gas phase value and is only weakly dependent upon the local environment. For both adsorbed MeI and suspended MeI, reactions of methyl radicals within MeI clusters lead to the formation of ethane, ethyl iodide, and diiodomethane. In contrast, reactions between the products of methyl iodide and water dissociation are responsible for the formation of methanol and carbon dioxide. Methane, formed as a result of reactions between methyl radicals and either parent MeI molecules or hydrogen atoms, is also observed. The product distribution is found to depend on the film's initial chemical composition as well as the electron fluence. Results from this study highlight the similarities in the carbon-containing products formed when monohalomethanes coadsorbed with amorphous solid water are irradiated by either electrons or photons

  13. Conditioning of radioactive ash residue in a wave of solid-phase exothermal reactions

    International Nuclear Information System (INIS)

    Karlina, O.K.; Varlakova, G.A.; Ozhovan, M.I.; Tivanskij, V.M.; Dmitriev, S.A.

    2001-01-01

    The abilities for utilization of exothermic reaction heat in solid phase for conditioning the ash residue produced as a result of solid radioactive waste burning are analyzed. It is shown that the process of ash residue making monolithic with obtaining the glass-like finish product containing 50-60 mass % of ash residue which meets the requirements for solidified radioactive wastes may be realized without energy supplying from external heat sources. The conditioning is realized in a special crucible furnace-container designed not only for the process conducting but also for subsequent storage or disposal of the finish product [ru

  14. Solid Catalysts and theirs Application in Biodiesel Production

    Directory of Open Access Journals (Sweden)

    Ramli Mat

    2012-12-01

    Full Text Available The reduction of oil resources and increasing petroleum price has led to the search for alternative fuel from renewable resources such as biodiesel. Currently biodiesel is produced from vegetable oil using liquid catalysts. Replacement of liquid catalysts with solid catalysts would greatly solve the problems associated with expensive separation methods and corrosion problems, yielding to a cleaner product and greatly decreasing the cost of biodiesel production. In this paper, the development of solid catalysts and its catalytic activity are reviewed. Solid catalysts are able to perform trans-esterification and esterification reactions simultaneously and able to convert low quality oils with high amount of Free Fatty Acids. The parameters that effect the production of biodiesel are discussed in this paper. Copyright © 2012 by BCREC UNDIP. All rights reservedReceived: 6th April 2012, Revised: 24th October 2012, Accepted: 24th October 2012[How to Cite: R. Mat, R.A. Samsudin, M. Mohamed, A. Johari, (2012. Solid Catalysts and Their Application in Biodiesel Production. Bulletin of Chemical Reaction Engineering & Catalysis, 7(2: 142-149. doi:10.9767/bcrec.7.2.3047.142-149] [How to Link / DOI: http://dx.doi.org/10.9767/bcrec.7.2.3047.142-149 ] | View in 

  15. Production, properties, and applications of hydrocolloid cellular solids.

    Science.gov (United States)

    Nussinovitch, Amos

    2005-02-01

    Many common synthetic and edible materials are, in fact, cellular solids. When classifying the structure of cellular solids, a few variables, such as open vs. closed cells, flexible vs. brittle cell walls, cell-size distribution, cell-wall thickness, cell shape, the uniformity of the structure of the cellular solid and the different scales of length are taken into account. Compressive stress-strain relationships of most cellular solids can be easily identified according to their characteristic sigmoid shape, reflecting three deformation mechanisms: (i) elastic distortion under small strains, (ii) collapse and/or fracture of the cell walls, and (iii) densification. Various techniques are used to produce hydrocolloid (gum) cellular solids. The products of these include (i) sponges, obtained when the drying gel contains the occasionally produced gas bubbles; (ii) sponges produced by the immobilization of microorganisms; (iii) solid foams produced by drying foamed solutions or gels containing oils, and (iv) hydrocolloid sponges produced by enzymatic reactions. The porosity of the manufactured cellular solid is subject to change and depends on its composition and the processing technique. The porosity is controlled by a range of methods and the resulting surface structures can be investigated by microscopy and analyzed using fractal methods. Models used to describe stress-strain behaviors of hydrocolloid cellular solids as well as multilayered products and composites are discussed in detail in this manuscript. Hydrocolloid cellular solids have numerous purposes, simple and complex, ranging from dried texturized fruits to carriers of vitamins and other essential micronutrients. They can also be used to control the acoustic response of specific dry food products, and have a great potential for future use in countless different fields, from novel foods and packaging to medicine and medical care, daily commodities, farming and agriculture, and the environmental, chemical

  16. Contribution to the modelling of gas-solid reactions and reactors

    International Nuclear Information System (INIS)

    Patisson, F.

    2005-09-01

    Gas-solid reactions control a great number of major industrial processes involving matter transformation. This dissertation aims at showing that mathematical modelling is a useful tool for both understanding phenomena and optimising processes. First, the physical processes associated with a gas-solid reaction are presented in detail for a single particle, together with the corresponding available kinetic grain models. A second part is devoted to the modelling of multiparticle reactors. Different approaches, notably for coupling grain models and reactor models, are illustrated through various case studies: coal pyrolysis in a rotary kiln, production of uranium tetrafluoride in a moving bed furnace, on-grate incineration of municipal solid wastes, thermogravimetric apparatus, nuclear fuel making, steel-making electric arc furnace. (author)

  17. In situ TEM observation of solid-gas reactions

    International Nuclear Information System (INIS)

    Kishita, K; Kamino, T; Watabe, A; Kuroda, K; Saka, H

    2008-01-01

    Under a gaseous atmosphere at high temperatures, almost all the materials (metal, catalysts, etc.) change their structures and properties. For the research and development of materials, it is of vital importance to clarify mechanisms of solid-gas and liquid-gas reactions. Recently an in situ TEM system combined with an environmental holder, which has a gas injection nozzle close to a specimen-heating element, has been developed. The gas injection nozzle permits gas to flow around the specimens sitting on the heating element made of a fine W filament. The newly developed in situ TEM has a differential pumping system; therefore, the pressure in the specimen chamber is maintained in the range of higher than 1 Pa, while the pressure in the electron gun chamber can be kept in the range of 10 -5 Pa. This system was applied to in situ observation of chemical reactions of metals with gases: Observation of oxidation and reduction under a gas pressure ranging from 10 -5 Pa to 1 Pa at high temperatures (room temperature to ∼1473 K) were successfully carried out on pure metal and rare metal catalysts at near-atomic resolution. This in situ environmental TEM system is promising for clarifying mechanisms of many solid-gas and liquid-gas reactions that take place at high temperatures under a gas atmosphere.

  18. Solid oxide fuel cells and hydrogen production

    International Nuclear Information System (INIS)

    Dogan, F.

    2009-01-01

    'Full text': A single-chamber solid oxide fuel cell (SC-SOFC), operating in a mixture of fuel and oxidant gases, provides several advantages over the conventional SOFC such as simplified cell structure (no sealing required). SC-SOFC allows using a variety of fuels without carbon deposition by selecting appropriate electrode materials and cell operating conditions. The operating conditions of single chamber SOFC was studied using hydrocarbon-air gas mixtures for a cell composed of NiO-YSZ / YSZ / LSCF-Ag. The cell performance and catalytic activity of the anode was measured at various gas flow rates. The results showed that the open-circuit voltage and the power density increased as the gas flow rate increased. Relatively high power densities up to 660 mW/cm 2 were obtained in a SC-SOFC using porous YSZ electrolytes instead of dense electrolytes required for operation of a double chamber SOFC. In addition to propane- or methane-air mixtures as a fuel source, the cells were also tested in a double chamber configuration using hydrogen-air mixtures by controlling the hydrogen/air ratio at the cathode and the anode. Simulation of single chamber conditions in double chamber configurations allows distinguishing and better understanding of the electrode reactions in the presence of mixed gases. Recent research efforts; the effect of hydrogen-air mixtures as a fuel source on the performance of anode and cathode materials in single-chamber and double-chamber SOFC configurations,will be presented. The presentation will address a review on hydrogen production by utilizing of reversible SOFC systems. (author)

  19. SOLID BIOFUEL UTILIZATION IN VEGETABLE OIL PRODUCTION

    Directory of Open Access Journals (Sweden)

    Slusarenko V.

    2016-08-01

    Full Text Available The paper deals with questions of creating at JSC “Alimentarmash "in the last 20 years the technological equipment for the production of vegetable oils from oilseeds: from the press for the final spin to mini oilfactory, using as an energy source for heating the liquid coolant (Thermal oil "Arian" of solid biofuels - husk of sunflower seeds.

  20. Synthesisofc-lifepo4 composite by solid state reaction method

    Science.gov (United States)

    Rahayu, I.; Hidayat, S.; Noviyanti, A. R.; Rakhmawaty, D.; Ernawati, E.

    2017-02-01

    In this research, the enhancement of LiFePO4 conductivity was conducted by doping method with carbon materials. Carbon-based materials were obtained from the mixture of sucrose, and the precursor of LiH2PO4 and α-Fe2O3 was synthesized by solid state reaction. Sintering temperature was varied at 700°C, 800°C, 900°C and 1,000°C. The result showed that C-LiFePO4 could be synthesized by using solid state reaction method. Based on the XRD and FTIR spectrums, C-LiFePO4 can be identified as the type of crystal, characterized by the appearance of sharp signal on (011), (211) and typical peak of LiFePO4 materials. The result of conductivity measurement from C-LiFePO4 at sintering temperature of 900°C and 1,000°C was 2×10-4 S/cm and 4×10-4S/cm, respectively. The conductivity value at sintering temperature of 700°C and 800°C was very small (<10-6 S/cm), which cannot be measured by the existing equipment.

  1. Low Energy Nuclear Reaction Products at Surfaces

    Science.gov (United States)

    Nagel, David J.

    2008-03-01

    This paper examines the evidence for LENR occurring on or very near to the surface of materials. Several types of experimental indications for LENR surface reactions have been reported and will be reviewed. LENR result in two types of products, energy and the appearance of new elements. The level of instantaneous power production can be written as the product of four factors: (1) the total area of the surface on which the reactions can occur, (2) the fraction of the area that is active at any time, (3) the reaction rate, that is, the number of reactions per unit active area per second, and (4) the energy produced per reaction. Each of these factors, and their limits, are reviewed. A graphical means of relating these four factors over their wide variations has been devised. The instantaneous generation of atoms of new elements can also be written as the product of the first three factors and the new elemental mass produced per reaction. Again, a graphical means of presenting the factors and their results over many orders of magnitude has been developed.

  2. Biogas production from solid pineapple waste

    Energy Technology Data Exchange (ETDEWEB)

    Tanticharoen, M.; Bhumiratana, S.; Tientanacom, S.; Pengsobha, L.

    1984-01-01

    Solid pineapple waste composed of shell and core was used as substrate in anaerobic fermentation producing CH4. The experiments were carried out using four 30-L vessels and no mixing, a 200-L plug-flow reactor, and a 5-cubic m stirred tank. Because of high acidity of the substrate, the loading rate is as low as 2.5 g dry solid added/L-day. The average gas yield is 0.3-0.5 L/g dry substrate. A pretreatment of wet solid with sludge effluent prior loading to the digester resulted in better stability of the biodigester than without pretreatment. These studies showed that loading rate can be much higher than those previously used. The 2-stage process was tested to determine a conversion efficiency of high loading and at much shorter reactor retention times. The results of the entire program indicated that biogas production from cannery pineapple waste is technically feasible.

  3. Preparation of molybdenum borides by combustion synthesis involving solid-phase displacement reactions

    International Nuclear Information System (INIS)

    Yeh, C.L.; Hsu, W.S.

    2008-01-01

    Preparation of molybdenum borides of five different phases in the Mo-B binary system (including Mo 2 B, MoB, MoB 2 , Mo 2 B 5 , and MoB 4 ) was performed by self-propagating high-temperature synthesis (SHS) with two kinds of the reactant samples. When elemental powder compacts with an exact stoichiometry corresponding to the boride phase were employed, self-sustaining reaction was only achieved in the sample with Mo:B = 1:1 and nearly single-phase MoB was yielded. Therefore, the other four boride compounds were prepared from the reactant compacts composed of MoO 3 , Mo, and B powders, within which the displacement reaction of MoO 3 with boron was involved in combustion synthesis. Experimental evidence shows that the extent of displacement reaction in the overall reaction has a significant impact on sustainability of the synthesis reaction, combustion temperature, reaction front velocity, and composition of the end product. An increase in the solid-phase displacement reaction taking place during the SHS process contributes more heat flux to the synthesis reaction, thus resulting in the increase of combustion temperature and enhancement of the reaction front velocity. Based upon the XRD analysis, formation of Mo 2 B, MoB 2 , and Mo 2 B 5 as the dominant boride phase in the end product was successful through the SHS reaction with powder compacts under appropriate stoichiometries between MoO 3 , Mo, and B. However, a poor conversion was observed in the synthesis of MoB 4 . The powder compact prepared for the production of MoB 4 yielded mostly Mo 2 B 5

  4. η production in proton-nucleus reactions

    International Nuclear Information System (INIS)

    Cassing, W.; Batko, G.; Vetter, T.; Wolf, G.

    1991-01-01

    The production of η-mesons in proton-nucleus reactions is analysed with respect to primary nucleon-nucleon (NN→NN η ) and secondary pion-nucleon (πN→ηN) production processes on the basis of Hartree-Fock groundstate momentum distributions and free on-shell production processes. The folding model adopted compares well for meson production with more involved simulations based on VUU transport equations. Similar to K + production in proton-nucleus reactions the η-mesons are primarily produced by the πN→ηN channel. However, η-mesons are absorbed in nuclei via excitation of the N * (1535) resonance which leads to strong distortions of the primordial spectra. On the other hand, the experimental mass dependence of the differential cross sections might yield information about the in-medium properties of this resonance. (orig.)

  5. High energy photons production in nuclear reactions

    International Nuclear Information System (INIS)

    Nifenecker, H.; Pinston, J.A.

    1990-01-01

    Hard photon production, in nucleus-nucleus collisions, were studied at beam energies between 10 and 125 MeV. The main characteristics of the photon emission are deduced. They suggest that the neutron-proton collisions in the early stage of the reaction are the main source of high energy gamma-rays. An overview of the theoretical approaches is given and compared with experimental results. Theoretical attempts to include the contribution of charged pion exchange currents to photon production, in calculations of proton-nucleus-gamma and nucleus-nucleus-gamma reactions, showed suitable fitting with experimental data

  6. Solid gas reaction phase diagram under high gas pressure

    International Nuclear Information System (INIS)

    Ishizaki, K.

    1992-01-01

    This paper reports that to evaluate which are the stable phases under high gas pressure conditions, a solid-gas reaction phase diagram under high gas pressure (HIP phase diagram) has been proposed by the author. The variables of the diagram are temperature, reactant gas partial pressure and total gas pressure. Up to the present time the diagrams have been constructed using isobaric conditions. In this work, the stable phases for a real HIP process were evaluated assuming an isochoric condition. To understand the effect of the total gas pressure on stability is of primary importance. Two possibilities were considered and evaluated, those are: the total gas pressure acts as an independent variable, or it only affects the fugacity values. The results of this work indicate that the total gas pressure acts as an independent variable, and in turn also affects the fugacity values

  7. Ultrasonic levitation for the examination of gas/solid reactions

    International Nuclear Information System (INIS)

    Kavouras, A.; Krammer, G.

    2003-01-01

    An experimental setup based on acoustic levitation for the examination of gas/solid reactions is presented. In this setup single particles in the diameter range 1 mm-30 μm can be held against gravity for any wanted time in a defined gas atmosphere at elevated temperatures. The change of particle size, shape, and position can be measured and recorded using an optical device, consisting of a camera and a long range microscope. Basic experiments with inert particles of different shape and solid density have shown that the axial position of a reacting particle can be employed to derive its weight change. A method to evaluate this change of the recorded position for the according weight change is proposed. Exemplary results in the context of dry flue gas cleaning using Ca(OH) 2 powder are presented. Single Ca(OH) 2 particles are exposed to a well defined gas atmosphere and after some time these particles are retrieved from the ultrasonic field for further analyses. Only an in situ measurement of the particle weight change (i.e., without removing the particle from the well defined reactive atmosphere) brings information regarding the uptake of water by the sorbent, which accompanies SO 2 and HCl absorption

  8. The Pictet-Spengler reaction in solid-phase combinatorial chemistry

    DEFF Research Database (Denmark)

    Nielsen, Thomas E; Diness, Frederik; Meldal, Morten

    2003-01-01

    The Pictet-Spengler reaction is an important reaction for the generation of tetrahydro-beta-carbolines and tetrahydroisoquinoline ring systems, which exhibit a range of biological and pharmacological properties. This review covers the solid-phase Pictet-Spengler reaction, as employed in solid...

  9. Enzymatic lignocellulose hydrolysis: Improved cellulase productivity by insoluble solids recycling

    Science.gov (United States)

    2013-01-01

    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. PMID:23336604

  10. Enzymatic lignocellulose hydrolysis: Improved cellulase productivity by insoluble solids recycling

    Directory of Open Access Journals (Sweden)

    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.

  11. Fusion reaction product diagnostics in ASDEX

    International Nuclear Information System (INIS)

    Bosch, H.S.

    1987-01-01

    A diagnostic method was developed to look for the charged fusion products from the D(D,p)T-reactions in the divertor tokamak ASDEX. With a semi-conductor detector it was possible to evaluate the ion temperature in thermal plasmas from the proton energy spectra as well as from the triton spectra. In lower-hybrid wave heated plasmas non-thermal (fast) ions were observed. These ions create fusion products with a characteristically different energy spectrum. (orig.)

  12. Solid-Phase Reactions of Iminium Ions: Cyclized Peptide Derivatives

    DEFF Research Database (Denmark)

    Wang, Yuanyuan

    formation of N,N’-aminals by nucleophilic attack of the peptide backbone is reversible under strongly acidic conditions and the N,N’-aminal is likely to be the kinetic product of many INCIC reactions. In addition, the N,N’-aminals are stable in the absence of acid but could be converted to the THIQ...... derivatives in solution phase under acid conditions in the presence of an active C-nucleophile in the side chain. The high yielding nature of the aminal formation is confirmed by solution phase synthesis. The introduced azide and alkyne residues in the side chain of N,N’-aminal products were further......BB may undergo auto-oxidation to quinazoline-2,4-diones in the absence of a suitable nucleophile on the side chain or backbone of the peptide (Chapter 4). The structure is confirmed by comparison with products obtained from solution-phase synthesis under the same conditions, one of which was confirmed...

  13. Solid targets for production of radioisotopes with cyclotron

    International Nuclear Information System (INIS)

    Paredes G, L.; Balcazar G, M.

    1999-01-01

    The design of targets for production of radioisotopes and radiopharmaceuticals of cyclotron to medical applications requires a detailed analysis of several variables such as: cyclotron operation conditions, choice of used materials as target and their physicochemical characteristics, activity calculation, the yielding of each radioisotope by irradiation, the competition of nuclear reactions in function of the projectiles energy and the collision processes amongst others. The objective of this work is to determine the equations for the calculation for yielding of solid targets at the end of the proton irradiation. (Author)

  14. Iron based superconductors and related compounds synthesized by solid state metathesis and high temperature reactions

    International Nuclear Information System (INIS)

    Frankovsky, Rainer

    2013-01-01

    The results of this thesis can be divided into three major topics, which can also be seen as different approaches of solid state chemistry to reveal interesting features of known and unknown compounds and to develop alternative synthesis routes. Firstly, known compounds with related structural motifs to the superconducting iron-arsenides were investigated regarding their structural and physical properties. In case of La 3 Pd 4 Ge 4 the influence of Fe doping on the properties was studied, whereas in the series ZrMAs (M=Ti,V) the physical properties have not yet been reported at all and were investigated for the first time. Secondly, an alternative synthesis route has been developed for the synthesis of superconducting LaFeAsO 1-x F x . This solid state metathesis reaction distinctly increased the quality of the samples compared to conventionally prepared products. Furthermore, the reaction pathway was investigated and clarified, which helps to understand the processes during high temperature solid state metathesis reactions in general. Thirdly, this alternative synthesis route was expanded to other systems and new compounds like co-substituted LaFe 1-x Mn x AsO 1-y F y were prepared and thoroughly investigated. This led to a complex study of the interplay of magnetism, electronic and structural conditions and the occurrence of superconducting properties. The investigation and understanding of such complex coherences will probably be decisive for the further understanding of the superconducting mechanism in iron based superconductors.

  15. Hydrothermal reactions of nuclear waste solids . A preliminary study

    International Nuclear Information System (INIS)

    Westsik, J.H. Jr.; Turcotte, R.P.

    1978-09-01

    A simulated high-level waste glass, Supercalcine, and some common ceramic and metallic solids were exposed to hydrothermal conditions at 250 and 350 0 C for time periods ranging from three days to three weeks. Most of the experiments were done in salt brine, but the glass study did include deionized water tests so that the influence of salt could be better understood. Under the extreme hydrothermal conditions of these tests, all of the materials examined underwent measurable changes. The glass is converted to a mixture of crystalline phases, depending upon conditions, giving NaFeSi 2 O 6 as the primary alteration product. The rate of alteration is higher in deionized water than in salt brine; however, under equivalent test conditions, 66% of the Cs originally in the glass is released to the salt brine, while only 6% is released to deionized water. Rb and Mo are the only other fission product elements significantly leached from the glass. Evidence is presented which shows that sintered Supercalcine undergoes chemical changes in salt brine that are qualitatively similar to those experienced by glass samples. High concentrations of Cs enter the aqueous phase, and Sn and Mo are mobilized. Scouting tests were made with a variety of materials including commercial glasses, granite, UO 2 , Al 2 O 3 , steel, and waste glasses. Weight losses under hydrothermal conditions are in a relatively narrow band, with glass and ceramic materials showing 3 to 20 times greater weight losses than 304L stainless steel in the 250 0 C test used. The conclusion from these studies is that virtually all solid materials show hydrothermal reactivity at temperatures between 250 and 350 0 C, and that these extreme conditions are not desirable

  16. Rotating solid foam reactors : mass transfer and reaction rate

    NARCIS (Netherlands)

    Tschentscher, R.

    2012-01-01

    In this thesis the performance and applicability of rotating solid foam stirrers is investigated. The stirrer consists, thereby of a solid, highly porous structure, which is used as stirrer and catalyst support simultaneously. The solid foam block occupies a large part of the reactor volume.

  17. Systems for production of polymer encapsuated solids

    Energy Technology Data Exchange (ETDEWEB)

    Bourcier, William L.; Aines, Roger D.; Baker, Sarah E.; Duoss, Eric B.; Maiti, Amitesh; Roberts, Jeffery J.; Spadaccini, Christopher M.; Stolaroff, Joshuah K.; Vericella, John J.; Lewis, Jennifer A.; Hardin, IV, James O.; Floyd, III, William C.

    2017-11-21

    Encapsulated solids are made by first encapsulating precursor materials in a polymer shell. The precursors are some combination of solids, liquids, gases, and/or gels. The precursors are then transformed into solids by emplacement of the capsule in an environment where gas or fluid transport into or out of the polymer shell causes transformation into solids.

  18. Solid state fermentation studies of citric acid production

    African Journals Online (AJOL)

    SERVER

    2008-03-04

    Mar 4, 2008 ... solid waste management, biomass energy conservation, production of high value products and little risk ... The carrier, sugarcane bagasse for solid state fermentation was procured from National Sugar Institute ... constant weight and designated as dry solid residue (DSR). The filtrate (consisting of biomass, ...

  19. Production and characterization of a Fe-Ni alloy by aqueous coloidal processing and solid state reaction; Producao e caracterizacao de uma liga Fe-Ni obtida por processamento coloidal aquoso e reacao de estado solido

    Energy Technology Data Exchange (ETDEWEB)

    Vieira Junior, Luiz Eloi; Rodrigues Neto, Joao Batista; Klein, AloIsio Nelmo; Hotza, Dachamir, E-mail: eloi_junior@hotmail.com, E-mail: jbrn.ufsc@gmail.com, E-mail: a.n.klein@ufsc.br, E-mail: d.hotza@ufsc.br [Universidade Federal de Santa Catarina (UFSC), Florianopolis, (Brazil); Moreno, Rodrigo, E-mail: rmoreno@icv.csic.es [Instituto de Ceramica y Vidrio (ICV/CSIC), Madri (Spain)

    2016-10-15

    Colloidal processing is a widely used technique to produce ceramic components. Several papers have been published in the last decade presenting the possibility to obtain aqueous concentrate stable suspension of metallic particles from their pH control and using dispersants. This paper aims to study the production of a steel with austenitic microstructure using elemental iron (Fe) and nickel (Ni) powders via colloidal route. For this, Zeta potential measurements were performed between pH 2 and 12 to Fe30Ni wt% composition. Aqueous suspensions reached solids concentrations of up to 45% v/v and processed by slip casting. The compacts were characterized by density (Archimedes), differential thermal analysis (DTA) and dilatometry. After sintering at 900°C to 1100°C/1h, the sintered bodies presented a microstructure with of annealing twins, porosity less than 10 %v/v approximate Vickers microhardness of 160 HV. (author)

  20. One-step simultaneous differential scanning calorimetry-FTIR microspectroscopy to quickly detect continuous pathways in the solid-state glucose/asparagine Maillard reaction.

    Science.gov (United States)

    Hwang, Deng-Fwu; Hsieh, Tzu-Feng; Lin, Shan-Yang

    2013-01-01

    The stepwise reaction pathway of the solid-state Maillard reaction between glucose (Glc) and asparagine (Asn) was investigated using simultaneous differential scanning calorimetry (DSC)-FTIR microspectroscopy. The color change and FTIR spectra of Glc-Asn physical mixtures (molar ratio = 1:1) preheated to different temperatures followed by cooling were also examined. The successive reaction products such as Schiff base intermediate, Amadori product, and decarboxylated Amadori product in the solid-state Glc-Asn Maillard reaction were first simultaneously evidenced by this unique DSC-FTIR microspectroscopy. The color changed from white to yellow-brown to dark brown, and appearance of new IR peaks confirmed the formation of Maillard reaction products. The present study clearly indicates that this unique DSC-FTIR technique not only accelerates but also detects precursors and products of the Maillard reaction in real time.

  1. Thermal theory of autowave processes in low-temperature solid-phase radiochemical reactions

    International Nuclear Information System (INIS)

    Barelko, V.V.; Barkalov, I.M.; Vaganov, D.A.; Zanin, A.M.; Kiryukhin, D.P.

    1982-01-01

    A new phenomenon in radiation cryochemistry concerning the class of autowave processes was previously discovered. It was observed in halogenation and hydrohalogenation of hydrocarbons and consisted of spontaneous, laminar propagation of a chemical transformation wave based on a frozen mixture of reagents previously irradiated with 60 Co γ-rays. The effect of the positive inverse correlation between the chemical conversion and brittle fracture of a solid sample of reagents is the phenomenological basis of the phenomenon; formation of fractures triggers a reactive process which takes place on their active surface (or in the layer adjacent to it), and the chemical reaction, in turn, stimulates the subsequent development of the process of decomposition. As a result, a single brittle fracture and chemical conversion wave which moves along the solid sample arises. Different mechanisms of generation of fracture surfaces under the effect of the reaction are possible. A difference in the densities of the initial reagents and the products of the reaction could be one of the causes of brittle fracture, and the thermal stresses induced by the exothermicity of the chemical processes could be another cause. The present work concerns the analysis of the features of the wave process which occurs based on the second, thermal mechanism. The analysis was conducted within the framework of a phenomenological approach which does not require specific definition of the nature of the chemical activation of the system during its brittle fracture

  2. Low-temperature synthesis of actinide tetraborides by solid-state metathesis reactions

    Science.gov (United States)

    Lupinetti, Anthony J [Los Alamos, NM; Garcia, Eduardo [Los Alamos, NM; Abney, Kent D [Los Alamos, NM

    2004-12-14

    The synthesis of actinide tetraborides including uranium tetraboride (UB.sub.4), plutonium tetraboride (PuB.sub.4) and thorium tetraboride (ThB.sub.4) by a solid-state metathesis reaction are demonstrated. The present method significantly lowers the temperature required to .ltoreq.850.degree. C. As an example, when UCl.sub.4 is reacted with an excess of MgB.sub.2, at 850.degree. C., crystalline UB.sub.4 is formed. Powder X-ray diffraction and ICP-AES data support the reduction of UCl.sub.3 as the initial step in the reaction. The UB.sub.4 product is purified by washing water and drying.

  3. Reaction of hydrogen atoms produced by radiolysis and photolysis in solid phase at 4 and 77 K

    International Nuclear Information System (INIS)

    Miyazaki, Tetsuo

    1991-01-01

    The behavior of H atoms in the solid phase has been reviewed with special attention to comparison of H atoms produced by radiolysis with those produced by photolysis. The paper consists of three parts. I -Production of H atoms: (1) the experimental results which indicate H-atom formation in the radiolysis of solid alkane are summarized; (2) ESR saturation behavior of trapped H atoms depends upon the method of H-atom-production, i.e. photolysis or radiolysis, and upon the initial energy of H atoms in the photolysis. II - Diffusion of H atoms: (1) activation energies for thermally-activated diffusion of H atoms are shown; (2) quantum diffusion of H atoms in solid H 2 is explained in terms of repetition of tunneling reaction H 2 + H → H + H 2 . III -Reaction of H atoms: (1) reactions and trapping processes of hot H atoms have been shown in solid methane and argon by use of hot H atoms with specified initial energy; (2) when H atoms are produced by the radiolysis of solvent alkane or by the photolysis of HI in the alkane mixtures at 77 K, the H atoms react very selectively with solute alkane at low concentration. The selective reaction of the H atom has been found in eight matrices; (3) activation energy for a hydrogen-atom-abstraction reaction by thermal H atoms at low temperatures is less than than several kJ mol -1 because of quantum tunneling. The absolute rate constants for H 2 (D 2 , HD) + H(D) tunneling reactions have been determined experimentally in solid hydrogen at 4.2K; (4) theoretical studies for tunneling reactions H 2 (D 2 ,HD) + H(D) at ultralow temperatures were reviewed. The calculated rate constants were compared with the rate constants obtained experimentally. (author)

  4. Reaction paths and equilibrium end-points in solid-solution aqueous-solution systems

    Science.gov (United States)

    Glynn, P.D.; Reardon, E.J.; Plummer, Niel; Busenberg, E.

    1990-01-01

    Equations are presented describing equilibrium in binary solid-solution aqueous-solution (SSAS) systems after a dissolution, precipitation, or recrystallization process, as a function of the composition and relative proportion of the initial phases. Equilibrium phase diagrams incorporating the concept of stoichiometric saturation are used to interpret possible reaction paths and to demonstrate relations between stoichiometric saturation, primary saturation, and thermodynamic equilibrium states. The concept of stoichiometric saturation is found useful in interpreting and putting limits on dissolution pathways, but there currently is no basis for possible application of this concept to the prediction and/ or understanding of precipitation processes. Previously published dissolution experiments for (Ba, Sr)SO4 and (Sr, Ca)C??O3orth. solids are interpreted using equilibrium phase diagrams. These studies show that stoichiometric saturation can control, or at least influence, initial congruent dissolution pathways. The results for (Sr, Ca)CO3orth. solids reveal that stoichiometric saturation can also control the initial stages of incongruent dissolution, despite the intrinsic instability of some of the initial solids. In contrast, recrystallisation experiments in the highly soluble KCl-KBr-H2O system demonstrate equilibrium. The excess free energy of mixing calculated for K(Cl, Br) solids is closely modeled by the relation GE = ??KBr??KClRT[a0 + a1(2??KBr-1)], where a0 is 1.40 ?? 0.02, a1, is -0.08 ?? 0.03 at 25??C, and ??KBr and ??KCl are the mole fractions of KBr and KCl in the solids. The phase diagram constructed using this fit reveals an alyotropic maximum located at ??KBr = 0.676 and at a total solubility product, ???? = [K+]([Cl-] + [Br-]) = 15.35. ?? 1990.

  5. Potential of solid state fermentation for production of ergot alkaloids

    OpenAIRE

    Trejo Hernandez, M.R.; Raimbault, Maurice; Roussos, Sevastianos; Lonsane, B.K.

    1992-01-01

    Production of total ergot alkaloids by #Claviceps fusiformis$ in solid state fermentation was 3.9 times higher compared to that in submerged fermentation. Production was equal in the case of #Claviceps purpurea$ but the spectra of alkaloids were advantageous with the use of solid state fermentation. The data establish potential of solid state fermentation which was not explored earlier for production of ergot alkaloids. (Résumé d'auteur)

  6. Cleaner production for solid waste management in leather industry ...

    African Journals Online (AJOL)

    Cleaner production for solid waste management in leather industry. ... From the processes, wastes are generated which include wastewater effluents, solid wastes, and hazardous wastes. In developing countries including Ethiopia, many ... The solid waste inventory of the factory has been carried out. The major problems ...

  7. Ion-beam mixing and solid-state reaction in Zr-Fe multilayers

    International Nuclear Information System (INIS)

    Paesano, A. Jr.; Motta, A.T.; Birtcher, R.C.; Ryan, E.A.; Teixeira, S.R.; Bruckmann, M.E.; Amaral, L.

    1997-01-01

    Vapor-deposited Zr-Fe multilayered thin films with various wavelengths and of overall composition either 50% Fe or Fe-rich up to 57% Fe were either irradiated with 300 keV Kr ions at temperatures from 25 K to 623 K to fluences up to 2 x 10 16 cm -2 , or simply annealed at 773 K in-situ in the Intermediate Voltage Electron microscope At Argonne National Laboratory. Under irradiation, the final reaction product is the amorphous phase in all cases studied, but the dose to amorphization depends on the temperature and on the wavelength. In the purely thermal case (annealing at 773 K), the 50-50 composition produces the amorphous phase but for the Fe-rich multilayers the reaction products depend on the multilayer wavelength. For small wavelength, the amorphous phase is still formed, but at large wavelength the Zr-Fe crystalline intermetallic compounds appear. These results are discussed in terms of existing models of irradiation kinetics and phase selection during solid state reaction

  8. A green synthesis of a layered titanate, potassium lithium titanate; lower temperature solid-state reaction and improved materials performance

    International Nuclear Information System (INIS)

    Ogawa, Makoto; Morita, Masashi; Igarashi, Shota; Sato, Soh

    2013-01-01

    A layered titanate, potassium lithium titanate, with the size range from 0.1 to 30 µm was prepared to show the effects of the particle size on the materials performance. The potassium lithium titanate was prepared by solid-state reaction as reported previously, where the reaction temperature was varied. The reported temperature for the titanate preparation was higher than 800 °C, though 600 °C is good enough to obtain single-phase potassium lithium titanate. The lower temperature synthesis is cost effective and the product exhibit better performance as photocatalysts due to surface reactivity. - Graphical abstract: Finite particle of a layered titanate, potassium lithium titanate, was prepared by solid-state reaction at lower temperature to show modified materials performance. Display Omitted - Highlights: • Potassium lithium titanate was prepared by solid-state reaction. • Lower temperature reaction resulted in smaller sized particles of titanate. • 600 °C was good enough to obtain single phased potassium lithium titanate. • The product exhibited better performance as photocatalyst

  9. Sodium-water reaction product flow system

    Energy Technology Data Exchange (ETDEWEB)

    Shirataki, K; Wada, H

    1978-11-18

    Purpose: To provide the subject equipments wherein thermal insulating layers which neither exfoliate nor react by the impact due to high temperature sodium and hydrogen gas and are used for mitigating the thermal impact are provided on the inner surfaces of the emission system equipments, thereby preventing the destruction of the emission system equipments. Constitution: Thermal insulating layers are formed on the inner surfaces of sodium-water reaction product emission system equipments, that is, the inner surface of the emission system pipeline, that of the accommodation vessel and the surface of the cyclone separator, by film treatment, coating or heat resisting coating, and these surfaces are covered with the layers. Each of the layers is made of a material which does not cause a rapid reaction with high temperature sodium or hydrogen gas nor exfoliates and is withstandable for several seconds in which the thermal impact of at least the emission system comes into question, and its thickness is more than one capable of securing the necessary thermal resistance computed by the thermal impact analysis of the emission system.

  10. Sodium-water reaction product flow system

    International Nuclear Information System (INIS)

    Shirataki, Koji; Wada, Hozumi.

    1978-01-01

    Purpose: To provide the subject equipments wherein thermal insulating layers which neither exfoliate nor react by the impact due to high temperature sodium and hydrogen gas and are used for mitigating the thermal impact are provided on the inner surfaces of the emission system equipments, thereby preventing the destruction of the emission system equipments. Constitution: Thermal insulating layers are formed on the inner surfaces of sodium-water reaction product emission system equipments, that is, the inner surface of the emission system pipeline, that of the accommodation vessel and the surface of the cyclone separator, by film treatment, coating or heat resisting coating, and these surfaces are covered with the layers. Each of the layers is made of a material which does not cause a rapid reaction with high temperature sodium or hydrogen gas nor exfoliates and is withstandable for several seconds in which the thermal impact of at least the emission system comes into question, and its thickness is more than one capable of securing the necessary thermal resistance computed by the thermal impact analysis of the emission system. (Yoshihara, H.)

  11. Hot reactions of 13N in solid methane at 77 K

    International Nuclear Information System (INIS)

    Fiergolla, J.; Nebeling, B.; Roessler, K.

    1987-09-01

    The chemical reactions of recoil- 13 N were studied in solid methane at 77 K. 13 N was generated via the the nuclear reaction 12 C(d,n) 13 N. The radiation dose deliverd by the 8.5 MeV deuterons amounted to D * = 0.6 eV per target molecule. The products formed by high energy chemical processes (hot chemistry) were analyzed by radio-gaschromatography. 13 NH 3 with 52% and CH 3 13 NH 2 with 25% radiochemical yield were found to be the main products. HC 13 N was not formed, but CH 3 13 CN amounts to 4%. For the more complex products carbon chain prolongation is prefered over multiple methylation such as show the yields of 8% for C 2 H 5 13 NH 2 and 3% (CH 3 ) 2 13 NH. (CH 3 ) 3 N was not detected. The formation of 13 NH 3 is due to hydrogen abstraction, that of CH 3 13 NH 2 due to insertion of NH radical into the C-H bond of CH 4 . Another, however, less probable pathway could be the insertion of 13 N into methane. The methylamine radical may react with another methane molecule via hydrogen transfer to methylamine or attack to CH 4 to dimethylamine. The 13 N-products were formed with high radiochemical purity and can potentially be applied for the synthesis of 13 N-radiopharmaceuticals. The reactions studied bear also informations on chemical processes in space (e.g. solar wind interactions with comets or interplanetary dust). 13 N-high energy chemical products are, however, of a less exobiological significance then those formed by hot carbon atoms, e.g. in the 'mirror' system 11 C/NH 3 (s). (orig.) [de

  12. Synthesis of Ca_3CO_4O_9 via solid state reaction

    International Nuclear Information System (INIS)

    Melo, K.P.; Dutra, R.P.S.; Marques, K.A.; Junior, S.M.S.; Brasileiro, C.T.; Coutinho, S.V.C.R.; Souza, T.; Chagas, T.F.; Silva, R.M.; Macedo, D.A.

    2016-01-01

    Solid oxide fuel cells (SOFCs) stand out as the most promising today's energy conversion technologies. In the development of cathode materials for SOFC, calcium cobaltate (Ca3Co4O9, C349) appears as a potential alternative to traditional lanthanum manganites. In this work, C349 was prepared via solid state reaction of stoichiometric mixtures containing CaCO3 from mollusk shells, in natura (M1) and heat treated at 550 ° C (M2), and Co3O4 obtained by citrate method. The M1 and M2 mixtures were calcined at 800 (powder) and 900 ° C (tablets) for 12 h. The crystal structure and phase composition of the powder and the reaction products were studied by X-ray diffraction Rietveld refinement of the diffraction data. The results showed the formation of free C349 secondary stages, showing a good alternative to use waste from seafood shells as raw material for obtaining high-value ceramics.(author)

  13. [Amylase production by Aureobasidium pullulans in liquid and solid media].

    Science.gov (United States)

    Lodato, P B; Forchiassin, F; Segovia de Huergo, M B

    1997-01-01

    Amylase production by a strain of Aureobasidium pullulans isolated in the laboratory was evaluated in liquid media (complex and synthetic) and in solid medium (wheat bran). There was an inhibitory effect in amylase production or amylase secretion by glucose. Asparagine was the best nitrogen source for amylase production (4-6 g/l). Only chlamidospores and melanin but not, amylase activity, were obtained with ammonium sulfate. Amylase production in solid culture was higher than the production obtained in the liquid media assayed. Optimum initial moisture content in solid culture ranged between 57 and 74%. No difference was observed in amylase production between solid media inoculated with cells grown in liquid or solid media.

  14. Pyrolysis-GCMS Analysis of Solid Organic Products from Catalytic Fischer-Tropsch Synthesis Experiments

    Science.gov (United States)

    Locke, Darren R.; Yazzie, Cyriah A.; Burton, Aaron S.; Niles, Paul B.; Johnson, Natasha M.

    2015-01-01

    Abiotic synthesis of complex organic compounds in the early solar nebula that formed our solar system is hypothesized to occur via a Fischer-Tropsch type (FTT) synthesis involving the reaction of hydrogen and carbon monoxide gases over metal and metal oxide catalysts. In general, at low temperatures (less than 200 C), FTT synthesis is expected to form abundant alkane compounds while at higher temperatures (greater than 200 C) it is expected to product lesser amounts of n-alkanes and greater amounts of alkene, alcohol, and polycyclic aromatic hydrocarbons (PAHs). Experiments utilizing a closed-gas circulation system to study the effects of FTT reaction temperature, catalysts, and number of experimental cycles on the resulting solid insoluble organic products are being performed in the laboratory at NASA Goddard Space Flight Center. These experiments aim to determine whether or not FTT reactions on grain surfaces in the protosolar nebula could be the source of the insoluble organic matter observed in meteorites. The resulting solid organic products are being analyzed at NASA Johnson Space Center by pyrolysis gas chromatography mass spectrometry (PY-GCMS). PY-GCMS yields the types and distribution of organic compounds released from the insoluble organic matter generated from the FTT reactions. Previously, exploratory work utilizing PY-GCMS to characterize the deposited organic materials from these reactions has been reported. Presented here are new organic analyses using magnetite catalyst to produce solid insoluble organic FTT products with varying reaction temperatures and number of experimental cycles.

  15. Near threshold two meson production in hardonic fusion reactions

    International Nuclear Information System (INIS)

    Jahn, R.

    1991-01-01

    An approved and funded exclusive COSY experiment is presented, which focuses on near threshold two meson production via the reactions p+d→ 3 He + π + π - and p+d→ 3 He+K + K-. It takes advantage of the high quality of the cooled external COSY beam and the existing spectrometer BIG KARL. The setup consists of a vertex wall and a scintillator cylinder and endcap covering a 4π solid angle. The large efficiency and high resolution of this detection method will yield precision data on the low energy (T 0 (975). Existing inclusive data as well as first results of a very recent 'semi-exclusive' experiment performed at SATURNE will be also be presented

  16. Hydrogen production from municipal solid waste

    Energy Technology Data Exchange (ETDEWEB)

    Wallman, P.H.; Richardson, J.H.; Thorsness, C.B. [and others

    1996-06-28

    We have modified a Municipal Solid Waste (MSW) hydrothermal pretreatment pilot plant for batch operation and blowdown of the treated batch to low pressure. We have also assembled a slurry shearing pilot plant for particle size reduction. Waste paper and a mixture of waste paper/polyethylene plastic have been run in the pilot plant with a treatment temperature of 275{degrees}C. The pilot-plant products have been used for laboratory studies at LLNL. The hydrothermal/shearing pilot plants have produced acceptable slurries for gasification tests from a waste paper feedstock. Work is currently underway with combined paper/plastic feedstocks. When the assembly of the Research Gasification Unit at Texaco (feed capacity approximately 3/4-ton/day) is complete (4th quarter of FY96), gasification test runs will commence. Laboratory work on slurry samples during FY96 has provided correlations between slurry viscosity and hydrothermal treatment temperature, degree of shearing, and the presence of surfactants and admixed plastics. To date, pumpable slurries obtained from an MSW surrogate mixture of treated paper and plastic have shown heating values in the range 13-15 MJ/kg. Our process modeling has quantified the relationship between slurry heating value and hydrogen yield. LLNL has also performed a preliminary cost analysis of the process with the slurry heating value and the MSW tipping fee as parameters. This analysis has shown that the overall process with a 15 MJ/kg slurry gasifier feed can compete with coal-derived hydrogen with the assumption that the tipping fee is of the order $50/ton.

  17. Rapid Synthesis of Lead Oxide Nanorods by One-step Solid-state Chemical Reaction at Room Temperature

    Institute of Scientific and Technical Information of China (English)

    CAO, Ya-Li(曹亚丽); JIA, Dian-Zeng(贾殿赠); LIU, Lang(刘浪); LUO, Jian-Min(骆建敏)

    2004-01-01

    A simple and facile method was reported to synthesize lead oxide nanorods. Nanorods of lead oxide were obtained directly from grinding solid metal salt and sodium hydroxide in agate mortar with the assistance of a suitable nonionic surfactant in only one step, which is different from the result of hydroxide in solution. The product has been characterized by XRD, TEM and SEM. The formation mechanism of rod-like morphology is discussed and the surfactant plays an important soft-template role in modifying the interface of solid-state reaction and according process of rod-formation.

  18. Hysteresis in the solid oxide fuel cell cathode reaction

    DEFF Research Database (Denmark)

    Jacobsen, Torben; Zachau-Christiansen, Birgit; Bay, Lasse

    2001-01-01

    The oxygen electrode reaction at the Pt/yttria-stabilised zirconia (YSZ) interface is investigated at 1000degreesC on Pt point electrodes on YSZ and YSZ point contacts on Pt. Linear potential sweeps show a pronounced non-linear current-voltage relation and inductive hysteresis, in particular at l...

  19. Compact hydrogen production systems for solid polymer fuel cells

    Science.gov (United States)

    Ledjeff-Hey, K.; Formanski, V.; Kalk, Th.; Roes, J.

    Generally there are several ways to produce hydrogen gas from carbonaceous fuels like natural gas, oil or alcohols. Most of these processes are designed for large-scale industrial production and are not suitable for a compact hydrogen production system (CHYPS) in the power range of 1 kW. In order to supply solid polymer fuel cells (SPFC) with hydrogen, a compact fuel processor is required for mobile applications. The produced hydrogen-rich gas has to have a low level of harmful impurities; in particular the carbon monoxide content has to be lower than 20 ppmv. Integrating the reaction step, the gas purification and the heat supply leads to small-scale hydrogen production systems. The steam reforming of methanol is feasible at copper catalysts in a low temperature range of 200-350°C. The combination of a small-scale methanol reformer and a metal membrane as purification step forms a compact system producing high-purity hydrogen. The generation of a SPFC hydrogen fuel gas can also be performed by thermal or catalytic cracking of liquid hydrocarbons such as propane. At a temperature of 900°C the decomposition of propane into carbon and hydrogen takes place. A fuel processor based on this simple concept produces a gas stream with a hydrogen content of more than 90 vol.% and without CO and CO2.

  20. Chemical cleavage reactions of DNA on solid support: application in mutation detection

    Directory of Open Access Journals (Sweden)

    Cotton Richard GH

    2003-05-01

    Full Text Available Abstract Background The conventional solution-phase Chemical Cleavage of Mismatch (CCM method is time-consuming, as the protocol requires purification of DNA after each reaction step. This paper describes a new version of CCM to overcome this problem by immobilizing DNA on silica solid supports. Results DNA test samples were loaded on to silica beads and the DNA bound to the solid supports underwent chemical modification reactions with KMnO4 (potassium permanganate and hydroxylamine in 3M TEAC (tetraethylammonium chloride solution. The resulting modified DNA was then simultaneously cleaved by piperidine and removed from the solid supports to afford DNA fragments without the requirement of DNA purification between reaction steps. Conclusions The new solid-phase version of CCM is a fast, cost-effective and sensitive method for detection of mismatches and mutations.

  1. Mitigating CO2 Leakage by Immobilizing CO2 into Solid Reaction Products: 13th International Conference on Greenhouse Gas Control Technologies, GHGT 2016. 14 November 2016 through 18 November 2016

    NARCIS (Netherlands)

    Wasch, L.J.; Wollenweber, J.; Neele, F.; Fleury, M.

    2017-01-01

    In the unlikely case of CO2 leakage from a storage reservoir, it is desirable to close the leak efficiently and permanently. This could be done by injecting a reactive solution into the leak path, thereby immobilizing migrating CO2 by consuming the gas and forming solid reactants. With regard to

  2. Solid acid zeolite catalysts for benzene/ ethylene alkylation reactions

    OpenAIRE

    2011-01-01

    Alkylation of benzene with ethylene to ethylbenzene is widely used in the petrochemical industry. Ethylbenzene is an important raw material in the petrochemical industry. It is used as feedstock for the production of styrene, an important material for plastic and rubber production.The conventional catalyst for this alkylation process is AlCl₃, which accounted for 24% of the worldwide ethylbenzene production in 2009.As utilization of this catalyst involves problems with separation, handling, s...

  3. Structure of fungal oxyluciferin, the product of the bioluminescence reaction.

    Science.gov (United States)

    Purtov, K V; Osipova, Z M; Petushkov, V N; Rodionova, N S; Tsarkova, A S; Kotlobay, A A; Chepurnykh, T V; Gorokhovatsky, A Yu; Yampolsky, I V; Gitelson, J I

    2017-11-01

    The structure of fungal oxyluciferin was determined, the enzymatic bioluminescence reaction under substrate saturation conditions with discrete monitoring of formed products was conducted, and the structures of the end products of the reaction were established. On the basis of these studies, the scheme of oxyluciferin degradation to the end products was developed. The structure of fungal oxyluciferin was confirmed by counter synthesis.

  4. Detection of different oxidation states of individual manganese porphyrins during their reaction with oxygen at a solid/liquid interface.

    Science.gov (United States)

    den Boer, Duncan; Li, Min; Habets, Thomas; Iavicoli, Patrizia; Rowan, Alan E; Nolte, Roeland J M; Speller, Sylvia; Amabilino, David B; De Feyter, Steven; Elemans, Johannes A A W

    2013-07-01

    Manganese porphyrins have been extensively investigated as model systems for the natural enzyme cytochrome P450 and as synthetic oxidation catalysts. Here, we report single-molecule studies of the multistep reaction of manganese porphyrins with molecular oxygen at a solid/liquid interface, using a scanning tunnelling microscope (STM) under environmental control. The high lateral resolution of the STM, in combination with its sensitivity to subtle differences in the electronic properties of molecules, allowed the detection of at least four distinct reaction species. Real-space and real-time imaging of reaction dynamics enabled the observation of active sites, immobile on the experimental timescale. Conversions between the different species could be tuned by the composition of the atmosphere (argon, air or oxygen) and the surface bias voltage. By means of extensive comparison of the results to those obtained by analogous solution-based chemistry, we assigned the observed species to the starting compound, reaction intermediates and products.

  5. Product removal and solids transport from fluidized-bed calciners

    International Nuclear Information System (INIS)

    Grimmett, E.S.; Munger, D.H.

    1978-09-01

    Methods of removing the solid product from pilot-plant and production fluidized-bed calciners, and transporting product to underground storage vaults are reported here. Testing of dense-phase solids transport systems in test loops during development of a 15-cm-diam. and 30-cm-diam. calciner are described. A lean-phase solid transport system is used with the Waste Calcining Facility. The results of some recent tests done in a lean-phase transport system connected to the 30-cm-diam. calciner are included in this report

  6. Multiparticle production in heavy-ion reactions

    International Nuclear Information System (INIS)

    Pelte, D.

    1980-01-01

    This lecture is concerned with the question how many particles and what kind of them are produced in heavy-ion collisions at energies about 10 MeV/n. We tend to assume that heavy-ion reactions at this energy are binary reactions. The experimental set consisting of two large ionization chambers serving to detection, in coincidence, the reaction fragments is described. With this set-up a number of reactions induced on 27 Al, 28 Si and 40 Ca by the 32 S beam of 135 and 190 MeV energy has been studied. Two-fragments inclusive and exclusive reactions were investigated. The assumption of a sequential statistical decay gives the best agreement with the data for all analyzed cases. (H.M.)

  7. Electric Energy production through Municipal solid wastes

    International Nuclear Information System (INIS)

    Agorio Comas, M.; Chediak Nunez, M.; Galan Prado, A.

    2010-01-01

    The main objective in this investment Project is to improve the integral management of urban solid waste in the city of Salto, Uruguay, obtaining favorable results for the environment and society, contributing moreover in Sustainable Development.First of all, it is recommended the remediation of the current Open air Municipal dumping site. Simultaneously with the Remediation process, a controlled dumping site with daily covers of the compacted solid waste has been designed, as a transition methodology with a lifetime of 3 years approximately.In addition to this, two sanitary landfills are designed wits29h a total lifetime of 7 years, for the operation after the controlled dumping site is closed. There is also a leachate treatment system to process the effluents of the landfills. In order to optimize the use of the landfills, is proposed the simultaneous implementation of a Separated Urban Solid Waste Collection System (SisRReVa). This consist in separating the Valuable Waste (VW) from wet or organic solid waste in origin (home, stores,etc)and collecting it separately.The VW are separated by type (paper, board, glass, plastic and metal) in a Valuable Waste Classification Plant. This plant is designed to process the VW generated in Salto and collected by the SisRReVa for about ten years from now on. (Author)

  8. Hydrothermal reaction of albite and a sodium aluminosilicate glass: A solid-state NMR study

    Science.gov (United States)

    Yang, Wang-hong Alex; Kirkpatrick, R. James

    1989-04-01

    We present here a solid-state NMR study of the structure and chemical composition of the products and mechanisms of the reaction of crystalline low albite and a glass of nearly albite composition with aqueous solutions of pH from 1 to 11 at 250°C. For the crystalline albite, there are no detectable bulk or surface structural changes due to aqueous attack, consistent with the idea that both cation exchange and disruption of the aluminosilicate framework occur only near the mineral/solution interface and that the hydrated surface layer, if it exists, is not more than about 30 Å thick. This reaction occurs by solution/reprecipitation, and its rate decreases with increasing solution pH, supporting the idea that the dissolution of feldspar is initiated by cation-exchange. For the glass, the reaction proceeds by cation exchange of protons for Na +, incorporation of molecular water into the bulk glass, and a small amount of depolymerization of the aluminosilicate framework in the interior of the glass. Cation exchange becomes less important with increasing solution pH. The incorporation of molecular water and cation-exchange cause structural changes in the glass via solidstate adjustment without dissolution/reprecipitation. The large cations in the hydrated glass (Na and K) probably have a shell of water molecules around them, with a maximum average coordination number of six. The secondary phases formed from both albite and the glass are often amorphous and can be well characterized by NMR. The compositional and structural variations of the amorphous phases are important factors in these reactions and cannot be ignored in theoretical models of aluminosilicate dissolution. As expected, the aluminum coordination in the secondary phases changes from six-fold to four-fold as the solution pH increases.

  9. Microanalysis of solid surfaces by nuclear reactions and elastic scattering

    International Nuclear Information System (INIS)

    Agius, B.

    1975-01-01

    The principles involved in the use of monokinetic light ions beams, of about 1MeV, to the study of surface phenomena are presented. Two complementary techniques are described: the use of elastic scattering, which allows the analysis of impurity elements heavier than the substrate components and the use of nuclear reactions specific of light elements. Typical sensitivities are of the order of 10 11 at/cm 2 in good cases. The depth resolution varies, according to the cases, from about a hundred angstroems to a few thousand angstroems [fr

  10. Solventless Substitution Reaction of Solid Phosphine Ligands with ...

    African Journals Online (AJOL)

    NJD

    the starting material into products at this temperature showed that the salt is the ... melt, since all the reactants are in the molten phase at this ..... an electron transfer chain (ETC) mechanism induced by the presence ... The heating device was.

  11. Developing and modelling of ohmic heating for solid food products

    DEFF Research Database (Denmark)

    Feyissa, Aberham Hailu; Frosch, Stina

    Heating of solid foods using the conventional technologies is time-consuming due to the fact that heat transfer is limited by internal conduction within the product. This is a big challenge to food manufactures who wish to heat the product faster to the desired core temperature and to ensure more...... uniform quality across the product. Ohmic heating is one of the novel technologies potentially solving this problem by allowing volumetric heating of the product and thereby reducing or eliminating temperature gradients within the product. However, the application of ohmic heating for solid food products...... such as meat and seafood is not industrially utilized yet. Therefore, the aim of the current work is to model and develop the ohmic heating technology for heating of solid meat and seafood. A 3D mathematical model of coupled heat transfer and electric field during ohmic heating of meat products has been...

  12. Computational modeling of chemical reactions and interstitial growth and remodeling involving charged solutes and solid-bound molecules.

    Science.gov (United States)

    Ateshian, Gerard A; Nims, Robert J; Maas, Steve; Weiss, Jeffrey A

    2014-10-01

    Mechanobiological processes are rooted in mechanics and chemistry, and such processes may be modeled in a framework that couples their governing equations starting from fundamental principles. In many biological applications, the reactants and products of chemical reactions may be electrically charged, and these charge effects may produce driving forces and constraints that significantly influence outcomes. In this study, a novel formulation and computational implementation are presented for modeling chemical reactions in biological tissues that involve charged solutes and solid-bound molecules within a deformable porous hydrated solid matrix, coupling mechanics with chemistry while accounting for electric charges. The deposition or removal of solid-bound molecules contributes to the growth and remodeling of the solid matrix; in particular, volumetric growth may be driven by Donnan osmotic swelling, resulting from charged molecular species fixed to the solid matrix. This formulation incorporates the state of strain as a state variable in the production rate of chemical reactions, explicitly tying chemistry with mechanics for the purpose of modeling mechanobiology. To achieve these objectives, this treatment identifies the specific theoretical and computational challenges faced in modeling complex systems of interacting neutral and charged constituents while accommodating any number of simultaneous reactions where reactants and products may be modeled explicitly or implicitly. Several finite element verification problems are shown to agree with closed-form analytical solutions. An illustrative tissue engineering analysis demonstrates tissue growth and swelling resulting from the deposition of chondroitin sulfate, a charged solid-bound molecular species. This implementation is released in the open-source program FEBio ( www.febio.org ). The availability of this framework may be particularly beneficial to optimizing tissue engineering culture systems by examining the

  13. Review on modeling development for multiscale chemical reactions coupled transport phenomena in solid oxide fuel cells

    International Nuclear Information System (INIS)

    Andersson, Martin; Yuan, Jinliang; Sunden, Bengt

    2010-01-01

    A literature study is performed to compile the state-of-the-art, as well as future potential, in SOFC modeling. Principles behind various transport processes such as mass, heat, momentum and charge as well as for electrochemical and internal reforming reactions are described. A deeper investigation is made to find out potentials and challenges using a multiscale approach to model solid oxide fuel cells (SOFCs) and combine the accuracy at microscale with the calculation speed at macroscale to design SOFCs, based on a clear understanding of transport phenomena, chemical reactions and functional requirements. Suitable methods are studied to model SOFCs covering various length scales. Coupling methods between different approaches and length scales by multiscale models are outlined. Multiscale modeling increases the understanding for detailed transport phenomena, and can be used to make a correct decision on the specific design and control of operating conditions. It is expected that the development and production costs will be decreased and the energy efficiency be increased (reducing running cost) as the understanding of complex physical phenomena increases. It is concluded that the connection between numerical modeling and experiments is too rare and also that material parameters in most cases are valid only for standard materials and not for the actual SOFC component microstructures.

  14. Chemical looping coal gasification with calcium ferrite and barium ferrite via solid–solid reactions

    International Nuclear Information System (INIS)

    Siriwardane, Ranjani; Riley, Jarrett; Tian, Hanjing; Richards, George

    2016-01-01

    Highlights: • BaFe 2 O 4 and CaFe 2 O 4 are excellent for chemical looping coal gasification. • BaFe 2 O 4 and CaFe 2 O 4 have minimal reactivity with synthesis gas. • Steam enhances the gasification process with these oxygen carriers. • Reaction rates of steam gasification of coal with CaFe 2 O 4 was better than with gaseous oxygen. • Coal gasification appears to be via solid–solid interaction with the oxygen carrier. - Abstract: Coal gasification to produce synthesis gas by chemical looping was investigated with two oxygen carriers, barium ferrite (BaFe 2 O 4 ) and calcium ferrite (CaFe 2 O 4 ). Thermo-gravimetric analysis (TGA) and fixed-bed flow reactor data indicated that a solid–solid interaction occurred between oxygen carriers and coal to produce synthesis gas. Both thermodynamic analysis and experimental data indicated that BaFe 2 O 4 and CaFe 2 O 4 have high reactivity with coal but have a low reactivity with synthesis gas, which makes them very attractive for the coal gasification process. Adding steam increased the production of hydrogen (H 2 ) and carbon monoxide (CO), but carbon dioxide (CO 2 ) remained low because these oxygen carriers have minimal reactivity with H 2 and CO. Therefore, the combined steam–oxygen carrier produced the highest quantity of synthesis gas. It appeared that neither the water–gas shift reaction nor the water splitting reaction promoted additional H 2 formation with the oxygen carriers when steam was present. Wyodak coal, which is a sub-bituminous coal, had the best gasification yield with oxygen carrier–steam while Illinois #6 coal had the lowest. The rate of gasification and selectivity for synthesis gas production was significantly higher when these oxygen carriers were present during steam gasification of coal. The rates and synthesis gas yields during the temperature ramps of coal–steam with oxygen carriers were better than with gaseous oxygen.

  15. Gas-Solid Reaction Properties of Fluorine Compounds and Solid Adsorbents for Off-Gas Treatment from Semiconductor Facility

    Directory of Open Access Journals (Sweden)

    Shinji Yasui

    2012-01-01

    Full Text Available We have been developing a new dry-type off-gas treatment system for recycling fluorine from perfluoro compounds present in off-gases from the semiconductor industry. The feature of this system is to adsorb the fluorine compounds in the exhaust gases from the decomposition furnace by using two types of solid adsorbents: the calcium carbonate in the upper layer adsorbs HF and converts it to CaF2, and the sodium bicarbonate in the lower layer adsorbs HF and SiF4 and converts them to Na2SiF6. This paper describes the fluorine compound adsorption properties of both the solid adsorbents—calcium carbonate and the sodium compound—for the optimal design of the fixation furnace. An analysis of the gas-solid reaction rate was performed from the experimental results of the breakthrough curve by using a fixed-bed reaction model, and the reaction rate constants and adsorption capacity were obtained for achieving an optimal process design.

  16. Solid-phase Synthesis of Combinatorial 2,4-Disubstituted-1,3,5-Triazine via Amine Nucleophilic Reaction

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Sung Won [KIST Gangneung Institute, Gangneung (Korea, Republic of); Ham, Jungyeob [Gangneung-Wonju National University, Gangneung (Korea, Republic of); Chang, Young-Tae [National University of Singapore, Singapore (Singapore); Lee, Jae Wook [University of Science and Technology, Daejon (Korea, Republic of)

    2015-01-15

    In combinatorial chemistry, solid-phase synthesis is a popular approach formass production of small molecules. Compared to solution-phase synthesis, it is easy to prepare and purify a large number of heterocyclic small molecules via solid-phase chemistry; the overall reaction time is decreased as well. 1,3,5-Triazine is a nitrogen-containing heterocyclic aromatic scaffold that was shown to be a druggable scaffold in recent studies. These structures have been reported as anticancer, antimicrobial, and antiretroviral compounds, as CDKs and p38 MAP kinase inhibitors, as estrogen receptor modulators, and as inosine monophosphate dehydrogenase inhibitors. we designed and synthesized disubstituted triazine compounds as an analog of disubstituted pyrimidine compounds. These disubstituted triazine compounds possess a linear structure which may have biological activity similar to that of disubstituted pyrimidine. Here we report the solid-phase synthesis of disubstituted triazine compounds.

  17. Solid-phase Synthesis of Combinatorial 2,4-Disubstituted-1,3,5-Triazine via Amine Nucleophilic Reaction

    International Nuclear Information System (INIS)

    Moon, Sung Won; Ham, Jungyeob; Chang, Young-Tae; Lee, Jae Wook

    2015-01-01

    In combinatorial chemistry, solid-phase synthesis is a popular approach formass production of small molecules. Compared to solution-phase synthesis, it is easy to prepare and purify a large number of heterocyclic small molecules via solid-phase chemistry; the overall reaction time is decreased as well. 1,3,5-Triazine is a nitrogen-containing heterocyclic aromatic scaffold that was shown to be a druggable scaffold in recent studies. These structures have been reported as anticancer, antimicrobial, and antiretroviral compounds, as CDKs and p38 MAP kinase inhibitors, as estrogen receptor modulators, and as inosine monophosphate dehydrogenase inhibitors. we designed and synthesized disubstituted triazine compounds as an analog of disubstituted pyrimidine compounds. These disubstituted triazine compounds possess a linear structure which may have biological activity similar to that of disubstituted pyrimidine. Here we report the solid-phase synthesis of disubstituted triazine compounds

  18. Methods for forming complex oxidation reaction products including superconducting articles

    International Nuclear Information System (INIS)

    Rapp, R.A.; Urquhart, A.W.; Nagelberg, A.S.; Newkirk, M.S.

    1992-01-01

    This patent describes a method for producing a superconducting complex oxidation reaction product of two or more metals in an oxidized state. It comprises positioning at least one parent metal source comprising one of the metals adjacent to a permeable mass comprising at least one metal-containing compound capable of reaction to form the complex oxidation reaction product in step below, the metal component of the at least one metal-containing compound comprising at least a second of the two or more metals, and orienting the parent metal source and the permeable mass relative to each other so that formation of the complex oxidation reaction product will occur in a direction towards and into the permeable mass; and heating the parent metal source in the presence of an oxidant to a temperature region above its melting point to form a body of molten parent metal to permit infiltration and reaction of the molten parent metal into the permeable mass and with the oxidant and the at least one metal-containing compound to form the complex oxidation reaction product, and progressively drawing the molten parent metal source through the complex oxidation reaction product towards the oxidant and towards and into the adjacent permeable mass so that fresh complex oxidation reaction product continues to form within the permeable mass; and recovering the resulting complex oxidation reaction product

  19. Direct determination of enthalpies of solid phase reactions by immersion method; Determination directe des enthalpies de reaction en phase solide par une methode de plongee

    Energy Technology Data Exchange (ETDEWEB)

    Roux, A; Richard, M; Eyraud, L; Stevanovic, M; Elston, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-07-01

    It is not generally possible to measure the enthalpy change corresponding to solid phase reactions using the dynamic differential thermal analysis method because these reactions are usually too slow at the temperature of operation of present equipment. A ballistic differential thermal analysis apparatus has been developed which is based on an immersion-compensation method; it overcomes the difficulties previously encountered. This apparatus has been used after calibration for determining the enthalpies of formation of calcium and cadmium titanates. and also the Wigner energies of BeO, MgO and Al{sub 2}O{sub 3} samples irradiated at variable dose at a temperature of under 100 deg. C. (authors) [French] Il n'est generalement pas possible de mesurer la variation d'enthalpie correspondant aux reactions en phase solide par la methode d'analyse thermique differentielle dynamique. En effet, ces reactions sont le plus souvent trop lentes aux temperatures d'utilisation des dispositifs actuels. Un appareil d'analyse thermique differentielle balistique, base sur une methode de plongee avec compensation, a ete mis au point et permet de surmonter les difficultes precedentes. Apres etalonnages, cet appareil a ete utilise pour la determination des enthalpies de formation du titanate de calcium et du titanate de cadmium ainsi que pour celle des energies Wigner emmagasinees dans des echantillons de BeO, MgO et Al{sub 2}O{sub 3} irradies a une temperature inferieure a 100 deg. C et a differentes doses. (auteurs)

  20. The Heck reaction in the production of fine chemicals

    NARCIS (Netherlands)

    Vries, Johannes G. de

    2001-01-01

    An overview is given of the use of the Heck reaction for the production of fine chemicals. Five commercial products have been identified that are produced on a scale in excess of 1 ton/year. The herbicide Prosulfuron™ is produced via a Matsuda reaction of 2-sulfonatobenzenediazonium on

  1. Comparative evaluation of torrefaction and hydrothermal carbonization of lignocellulosic biomass for the production of solid biofuel

    International Nuclear Information System (INIS)

    Kambo, Harpreet Singh; Dutta, Animesh

    2015-01-01

    Highlights: • A comparative characterization of HTC and torrefaction is proposed. • The reaction temperature is the most governing parameter in the HTC process. • The inorganic compositions of biomass were significantly reduced via HTC. • The hydrochar produced at 260 °C shows fuel qualities comparable to that of coal. - Abstract: The work presented in this study demonstrates the potential of using hydrothermal carbonization (HTC) on miscanthus feedstock for the production of a carbon-rich solid fuel, referred to as hydrochar, whose physicochemical properties are comparable to that of coal. The effects of the processing conditions on the mass yield, energy yield and higher heating values (HHVs) were examined by varying the reaction temperature (190, 225, and 260 °C), the reaction time (5, 15, and 30 min) and the feedstock-to-water ratio (1:6 and 1:12). The results show that the reaction temperature is the most significant parameter governing the physicochemical properties of biomass. Increasing reaction temperature reduces the mass yield; however, it also significantly enhances the energy density of solid products. The hydrochar samples produced at 260 °C show a maximum energy density of 26–30 MJ/kg, with 66–74% of energy retained in the solid product. In comparison, the energy density, grindability, and hydrophobicity of the solid samples produced via torrefaction (a conventional thermal pre-treatment) were considerably lower than the hydrochar samples, even if the reaction time was kept much higher than HTC. Furthermore, the inorganic metallic composition of miscanthus feedstock almost remained unaffected after torrefaction; however, it was significantly reduced (30–70%) via HTC.

  2. The effect of interfaces on solid-state reactions between oxides

    International Nuclear Information System (INIS)

    Johnson, M.T.; Carter, C.B.

    1998-01-01

    A thin-film geometry has been used to study fundamental solid-state reaction processes occurring at interfaces in two spinel-forming oxide systems. In the first system, NiO/Al 2 O 3 , epitactic NiO films were deposited on various orientations of single-crystal α-Al 2 O 3 . In this case, the reaction kinetics were studied and correlated with the interfacial structure (or substrate orientation). In the second, In 2 O 3 /MgO, solid-state reactions were studied under the influence of an electric field. The electric field provides a driving force for mass transport that affects both the reaction process and the morphological stability of an interface

  3. Curing reactions of bismaleimide resins catalyzed by triphenylphosphine. High resolution solid-state 13C NMR study

    International Nuclear Information System (INIS)

    Shibahara, Sumio; Enoki, Takashi; Yamamoto, Takahisa; Motoyoshiya, Jiro; Hayashi, Sadao.

    1996-01-01

    The curing reactions of bismaleimide resins consisted of N,N'-4,4'-diphenylmethanebismaleimide (BMI) and o,o'-diallylbisphenol-A (DABA) in the presence of triphenylphosphine (TPP) as a catalyst were investigated. DSC measurements showed that the catalytic effect of TPP on the curing reaction of BMI was more in the presence of DABA than in its absence. In order to explore this curing reaction, N-phenylmaleimide (PMI) and o-allylphenol (AP) were selected as model compounds. The products of the PMI/TPP system were oligomers and polymers of PMI, whereas the main product of the PMI/AP/TPP system was the PMI trimer which had the five-membered ring formed via the phosphonium ylide intermediate. In these model reactions, 13 C NMR was found to be useful to distinguish between trimerization and polymerization of PMI. On the basis of the results of the model reactions, the curing reactions of bismaleimide resins were investigated by high resolution solid state 13 C NMR techniques. In the BMI/TPP system, maleimides polymerize above 175degC, but the polymerization does not proceed at 120degC. On the other hand, maleimides trimerize above 120degC in the presence of DABA and TPP. The mechanism of the trimerization is briefly discussed. (author)

  4. Review of the Production of Biodiesel from Waste Cooking Oil using Solid Catalysts

    Directory of Open Access Journals (Sweden)

    N.H. Said

    2015-06-01

    Full Text Available The need for fossil fuels and the emissions generated from these fuels are increasing daily. Researchers are concerned with global warming as well as climate change; and energy sustainability and material usages are important issues today. Waste cooking oil (WCO can be processed into biodiesel as an alternative fuel to replace diesel. Production of biodiesel using WCO as the feedstock has been of growing interest for the last two decades. A number of research papers related to the improvements in production, raw materials and catalyst selection have been published. This paper reviews the various types of heterogeneous solid catalyst in the production of biodiesel via the transesterification of WCO. The catalysts used can be classified according to their state presence in the transesterification reaction as homogeneous or heterogeneous catalysts. Homogeneous catalysts act in the same liquid phase as the reaction mixture, whereas heterogeneous catalysts act in a solid phase with the reaction mixture. Heterogeneous catalysts are non-corrosive, a green process and environmentally friendly. They can be recycled and used several times, thus offering a more economic pathway for biodiesel production. The advantages and drawbacks of these heterogeneous catalysts are presented. Future work focuses on the application of economically and environmentally friendly solid catalysts in the production of biodiesel using WCO as the raw material.

  5. Electron transfer reactions in microporous solids. Progress report, September 1990--January 1993

    Energy Technology Data Exchange (ETDEWEB)

    Mallouk, T.E.

    1993-01-01

    Basic thrust the research program involves use of microporous solids (zeolites, clays, layered and tunnel structure oxide semiconductors) as organizing media for artificial photosynthetic systems. Purpose of the microporous solid is twofold. First, it induces spatial organization of photoactive and electroactive components (sensitizers, semiconductor particles, electron relays, and catalysts) at the solid-solution interface, enhancing the quantum efficiency of charge separation and separating physically the ultimate electron donor and acceptor in the electron transport chain. Second, since the microcrystalline solid admits only molecules of a certain charge and size, it is possible to achieve permanent charge separation by sieving chemical photoproducts (e.g., H{sub 2} and I{sub 3}{sup {minus}}, or H{sub 2} and O{sub 2)} from each other. Spectroscopic and electrochemical methods are used to study the kinetics of electron transfer reactions in these hybrid molecular/solid state assemblies.

  6. Maillard reaction products in pet foods

    NARCIS (Netherlands)

    Rooijen, van C.

    2015-01-01

    Pet dogs and cats around the world are commonly fed processed commercial foods throughout their lives. Often heat treatments are used during the processing of these foods to improve nutrient digestibility, shelf life, and food safety. Processing is known to induce the Maillard reaction, in which

  7. High energy gamma-ray production in nuclear reactions

    International Nuclear Information System (INIS)

    Pinston, J.A.; Nifenecker, H.; Nifenecker, H.

    1989-01-01

    Experimental techniques used to study high energy gamma-ray production in nuclear reactions are reviewed. High energy photon production in nucleus-nucleus collisions is discussed. Semi-classical descriptions of the nucleus-nucleus gamma reactions are introduced. Nucleon-nucleon gamma cross sections are considered, including theoretical aspects and experimental data. High energy gamma ray production in proton-nucleus reactions is explained. Theoretical explanations of photon emission in nucleus-nucleus collisions are treated. The contribution of charged pion currents to photon production is mentioned

  8. MgAl-Layered Double Hydroxide Solid Base Catalysts for Henry Reaction: A Green Protocol

    Directory of Open Access Journals (Sweden)

    Magda H. Abdellattif

    2018-03-01

    Full Text Available A series of MgAl-layered double hydroxide (MgAl-HT, the calcined form at 500 °C (MgAlOx, and the rehydrated one at 25 °C (MgAl-HT-RH were synthesized. Physicochemical properties of the catalysts were characterized by X-ray diffraction (XRD and scanning electron microscopy (SEM. Surface area of the as-synthesized, calcined, and rehydrated catalysts was determined by N2 physisorption at −196 °C. CO2 temperature-programmed desorption (CO2-TPD was applied to determine the basic sites of catalysts. The catalytic test reaction was carried out using benzaldehyde and their derivatives with nitromethane and their derivatives. The Henry products (1–15 were obtained in a very good yield using MgAl-HT-RH catalyst either by conventional method at 90 °C in liquid phase or under microwave irradiation method. The mesoporous structure and basic nature of the rehydrated solid catalyst were responsible for its superior catalytic efficiency. The robust nature was determined by using the same catalyst five times, where the product % yield was almost unchanged significantly.

  9. Photochemical reaction products in air pollution

    Energy Technology Data Exchange (ETDEWEB)

    Stephens, E R; Darley, E F; Taylor, O C; Scott, W E

    1961-01-01

    Isolation and purification of peroxyacetyl nitrate (PAN) from artificial photochemical reaction of olefins and NO/sub x/ in air are analyzed. Olefin splits at the double bond, one end forming carbonyl compound and the other yielding PAN, among others. At concentrations below 1 ppM, PAN causes plant damage. At a concentration of about 1 ppM, PAN is a strong eye irritant.

  10. Production of radioactive nuclides in inverse reaction kinematics

    International Nuclear Information System (INIS)

    Traykov, E.; Rogachevskiy, A.; Bosswell, M.; Dammalapati, U.; Dendooven, P.; Dermois, O.C.; Jungmann, K.; Onderwater, C.J.G.; Sohani, M.; Willmann, L.; Wilschut, H.W.; Young, A.R.

    2007-01-01

    Efficient production of short-lived radioactive isotopes in inverse reaction kinematics is an important technique for various applications. It is particularly relevant when the isotope of interest is only a few nucleons away from a stable isotope. In this article production via charge exchange and stripping reactions in combination with a magnetic separator is explored. The relation between the separator transmission efficiency, the production yield, and the choice of beam energy is discussed. The results of some exploratory experiments will be presented

  11. Production of Citric Acid from Solid State Fermentation of Sugarcane ...

    African Journals Online (AJOL)

    Aspergillus niger is the leading microorganism of choice for citric acid production. Sugarcane waste was used as substrate under solid state fermentation to comparatively evaluate the citric acid production capacity of Aspergillus niger isolates and the indigenous microflora in the sugarcane waste. Known optimal cultural ...

  12. Lovastatin production by Aspergillus terreus in solid state and ...

    African Journals Online (AJOL)

    user

    Department of Biochemistry of Physiologically Active Compounds, Institute of ... Keywords: lovastatin, submerged fermentation, solid state fermentation, production ... water need in up-stream processing which minimizes production expense (Holker .... authors, a slowly utilizable carbon source is preferable for high lovastatin ...

  13. Lovastatin production by Aspergillus terreus in solid state and ...

    African Journals Online (AJOL)

    user

    Department of Biochemistry of Physiologically Active Compounds, Institute of ... Keywords: lovastatin, submerged fermentation, solid state fermentation, production ... water need in up-stream processing which minimizes production expense (Holker et .... Effect of carbon and nitrogen sources on lovastatin yield by Aspergillus ...

  14. Banana peel: A novel substrate for cellulase production under solid ...

    African Journals Online (AJOL)

    These results indicated that banana peel provided necessary nutrients for cell growth and cellulase synthesis. It can be used as a potential substrate for cellulase production by T. viride GIM 3.0010 under solid-state fermentation. To the best of our knowledge, this is the first report on cellulase production using banana peel.

  15. Study of reaction sequences for formation of solid solution: 0,48 ...

    African Journals Online (AJOL)

    ... of a low concentration of ions forming the perovskite structure PZT (Pb2+, Zr4+ et Ti4+) by other ions (Zn2+, Cr3+ et Sb+5 in our study) alters the reaction sequences training of the solid solution PZT and especially the formation of intermediate phase. Keywords: PZT / Calcination / TGA / DTA / RX / Piezoelectric Ceramics ...

  16. Formation of amorphous Ti-50at.%Pt by solid state reactions during mechanical alloying

    CSIR Research Space (South Africa)

    Mahlatji, ML

    2013-10-01

    Full Text Available Mechanical alloying of an equiatomic mixture of crystalline elemental powders of Ti and Pt in a high-energy ball mill results in formation of an amorphous alloy by solid-state reactions. Mechanical alloying was carried out in an argon atmosphere...

  17. Biodiesel production from acid oils and ethanol using a solid basic resin as catalyst

    International Nuclear Information System (INIS)

    Marchetti, J.M.; Errazu, A.F.

    2010-01-01

    In the search of an alternative fuel to substitute diesel fuel, biodiesel appears as one of the most promising sources of energy for diesel engines because of its environmental advantages and also due to the evolution of the petroleum market. Refined oil is the conventional raw material for the production of this biofuel; however, its major disadvantage is the high cost of its production. Therefore, frying oils, waste oils, crude oils and/or acid oils are being tested as alternative raw materials; nevertheless, there will be some problems if a homogeneous basic catalyst (NaOH) is employed due to the high amount of free fatty acid present in the raw oil. In this work, the transesterification reaction of acid oil using solid resin, Dowex monosphere 550 A, was studied as an alternative process. Ethanol was employed to have a natural and sustainable final product. The reaction temperature's effects, the initial amount of free fatty acid, the molar ratio of alcohol/oil and the type of catalyst (homogeneous or heterogeneous) over the main reaction are analyzed and their effects compared. The results obtained show that the solid resin is an alternative catalyst to be used to produce fatty acid ethyl esters (FAEEs) by a transesterification reaction with a final conversion over 90%. On the other hand, the time required to achieve this conversion is bigger than the one required using conventional technology which employs a homogeneous basic catalyst. This reaction time needs to be optimized. (author)

  18. Exclusive hadron production in two photon reactions

    International Nuclear Information System (INIS)

    Poppe, M.

    1986-02-01

    This paper summarises experimental results on exclusive hadron production in two photon collisions at electron positron storage rings and attempts some interpretation. Experimental know how is described and new suggestions are made for future analyses. New model calculations on resonance form factors and pair production amplitudes are presented. The two photon vertex is decomposed such that experiments can be parameterised with the minimal number of free parameters. Selection rules for off shell photon collisions are given in addition to Yang's theorems. (orig.)

  19. In Situ Monitoring of Chemical Reactions at a Solid-Water Interface by Femtosecond Acoustics.

    Science.gov (United States)

    Shen, Chih-Chiang; Weng, Meng-Yu; Sheu, Jinn-Kong; Yao, Yi-Ting; Sun, Chi-Kuang

    2017-11-02

    Chemical reactions at a solid-liquid interface are of fundamental importance. Interfacial chemical reactions occur not only at the very interface but also in the subsurface area, while existing monitoring techniques either provide limited spatial resolution or are applicable only for the outmost atomic layer. Here, with the aid of the time-domain analysis with femtosecond acoustics, we demonstrate a subatomic-level-resolution technique to longitudinally monitor chemical reactions at solid-water interfaces, capable of in situ monitoring even the subsurface area under atmospheric conditions. Our work was proven by monitoring the already-known anode oxidation process occurring during photoelectrochemical water splitting. Furthermore, whenever the oxide layer thickness equals an integer  number of the effective atomic layer thickness, the measured acoustic echo will show higher signal-to-noise ratios with reduced speckle noise, indicating the quantum-like behavior of this coherent-phonon-based technique.

  20. An alternative preparation method for ion exchanged catalysts: Solid state redox reaction

    DEFF Research Database (Denmark)

    Schneider, E.; Hagen, A.; Grunwaldt, J.-D.

    2004-01-01

    A new method for modifying zeolites with zinc is proposed. The solid state redox reaction between metallic zinc and ZSM-5 zeolites with different Si/Al ratios was investigated by temperature programmed hydrogen evolution (TPHE), X-ray absorption near edge structure (XANES) and diffuse reflectance...... infrared Fourier transform spectroscopy (DRIFTS). The evolution of hydrogen was detected at temperatures above 620 K. The source of hydrogen was the solid state redox reaction of the metal with protons of the support. The samples exhibit catalytic activity in ethane aromatization indicating that zinc...... should be located at the same sites as in catalysts prepared by conventional methods. Combination of XANES and catalytic activity point to zinc being mainly present in tetrahedral geometry under reaction conditions....

  1. Production of solid deuterium targets by ion implantation

    International Nuclear Information System (INIS)

    Csikai, J.; Szegedi, S.; Olah, L.; El-Megrab, A.M.; Molla, N.I.; Rahman, M.M.; Miah, R.U.; Habbani, F.; Shaddad, I.

    1997-01-01

    Solid metal, semiconductor and metallic glass samples were irradiated with deuteron atomic ions between 60 and 180 keV incident energies. Accumulation rates of deuterons in different targets were recorded by the detection of protons and neutrons via the 2 H(d,p) and 2 H(d,n) reactions. A simple analytical expression is given to describe the kinetics of the accumulation. The dependence of the reaction rate on the deuteron energy gives information on the concentration profile in addition to the neutron flux density spectra. A varying distortion of the implanted deuteron profiles by a change in the beam energy were also observed for different targets. (orig.)

  2. Reaction kinetics, reaction products and compressive strength of ternary activators activated slag designed by Taguchi method

    NARCIS (Netherlands)

    Yuan, B.; Yu, Q.L.; Brouwers, H.J.H.

    2015-01-01

    This study investigates the reaction kinetics, the reaction products and the compressive strength of slag activated by ternary activators, namely waterglass, sodium hydroxide and sodium carbonate. Nine mixtures are designed by the Taguchi method considering the factors of sodium carbonate content

  3. Preparation and characterization of bismuth ruthenate pyrochlore via solid state reaction and sol-gel methods

    Directory of Open Access Journals (Sweden)

    Mayuree Sansernnivet

    2010-01-01

    Full Text Available Bismuth ruthenate pyrochlores, potential cathode materials for intermediate temperature solid oxide fuel cells(ITSOFCs, were prepared via solid-state and sol-gel method. Effects of the preparation routes and conditions on the phase and microstructures of the materials were investigated in this study using XRD and SEM. The study showed that the preparation method and the adding sequence of the starting meterials have a significant effect on the crystal phase and the particle size obtained. Sol-gel synthesis could yield a material with only pyrochlore structure, i.e. Bi2Ru2O7, while the solid state method yielded powder with a small amount of the secondary RuO2 phase. The sol-gel synthesis resulted in materialswith a finer particle size (~0.3-1.0 μm compared to powder synthesized via the solid state reaction method.

  4. Tritium production in neutron induced reactions

    International Nuclear Information System (INIS)

    Krasa, A.; Andreotti, E.; Hult, M.; Marissens, G.; Plompen, A.; Angelone, M.; Pillon, M.

    2011-01-01

    We present an overview of the present knowledge of (n,t) reaction excitation functions in the 14-21 MeV energy range for Cd, Cr, Fe, Mg, Mo, Ni, Pb, Pd, Ru, Sn, Ti, Zr. Experimental data are compared with evaluated data libraries, cross-section systematics, and TALYS calculations. The new values for the "5"0Cr(n,t)"4"8V cross-section measured using γ-spectrometry at 15, 16, 17.3 MeV are presented. The trend of the results confirms that while early experimental data at 14.6 MeV are strongly overestimated, the calculations performed with the default version of TALYS strongly underestimate the excitation curve in the measured energy region

  5. Quantitation of Maillard reaction products in commercially available pet foods

    NARCIS (Netherlands)

    Rooijen, van C.; Bosch, G.; Poel, van der A.F.B.; Wierenga, P.A.; Alexander, L.; Hendriks, W.H.

    2014-01-01

    During processing of pet food, the Maillard reaction occurs, which reduces the bioavailability of essential amino acids such as lysine and results in the formation of advanced Maillard reaction products (MRPs). The aim of this study was to quantitate MRPs (fructoselysine (FL), carboxymethyllysine

  6. Carbon-14 immobilization via the CO2-Ba(OH)2 hydrate gas-solid reaction

    International Nuclear Information System (INIS)

    Haag, G.L.

    1980-01-01

    Although no restrictions have been placed on the release of carbon-14, it has been identified as a potential health hazard due to the ease in which it may be assimilated into the biosphere. The intent of the Carbon-14 Immobilization Program, funded through the Airborne Waste Program Management Office, is to develop and demonstrate a novel process for restricting off-gas releases of carbon-14 from various nuclear facilities. The process utilizes the CO 2 -Ba(OH) 2 hydrate gas-solid reaction to directly remove and immobilize carbon-14. The reaction product, BaCO 3 , possesses both the thermal and chemical stability desired for long-term waste disposal. The process is capable of providing decontamination factors in excess of 1000 and reactant utilization of greater than 99% in the treatment of high volumetric, airlike (330 ppM CO 2 ) gas streams. For the treatment of an air-based off-gas stream, the use of packed beds of Ba(OH) 2 .8H 2 O flakes to remove CO 2 has been demonstrated. However, the operating conditions must be maintained between certain upper and lower limits with respect to the partial pressure of water. If the water vapor pressure in the gas is less than the dissociation vapor pressure of Ba(OH) 2 .8H 2 O, the bed will deactivate. If the vapor pressure is considerably greater, pressure drop problems will increase with increasing humidity as the particles curl and degrade. Results have indicated that when operated in the proper regime, the bulk of the increase in pressure drop results from the conversion of Ba(OH) 2 .8H 2 O to BaCO 3 and not from the hydration of the commercial Ba(OH) 2 .8H 2 O (i.e. Ba(OH) 2 .7.50H 2 O) to Ba(OH) 2 .8H 2 O

  7. Potential useful products from solid wastes.

    Science.gov (United States)

    Golueke, C G; Diaz, L F

    1991-10-01

    Wastes have been aptly defined as "items, i.e. resources, that have been discarded because their possessors no longer have an apparent use for them". Accordingly, "wastes" have a significance only in relation to the items and those who have discarded them. The discarded items now are resources awaiting reclamation. Reclamation usually involves either salvage or conversion--or in modern terminology, "reuse" or "recycling". Reclamation for reuse consists in refurbishing or other upgrading without significantly altering original form and composition. Examples of wastes amenable to reuse are containers (bottles, etc.), cartons and repairable tires. With "recycling" (i.e. conservation), the discarded items are processed such that they become raw material, i.e. resources in the manufacture of "new" products. The variety of processes is wide, ranging from simply physical (grinding) through thermal (melting, gasification, combustion), to biological (composting, biogasification, hydrolysis, microbial protein production). In the paper, reuse and recycling (conversion) are evaluated in terms of advantages and disadvantages (limitations) and their respective technologies are described and discussed in detail.

  8. Coherent π0 production in neutrino reactions

    International Nuclear Information System (INIS)

    Rein, D.; Sehgal, L.M.

    1983-01-01

    We have calculated the cross section and angular distribution of the neutral current process ν+K -> ν+K+π 0 involving the coherent interaction of a neutrino with a complex nucleus. A contrast is made to incoherent production ν+n -> ν+n+π 0 on a single nucleon. The results are compared with observations from some recent experiments. (orig.)

  9. EPR and NMR detection of transient radicals and reaction products

    International Nuclear Information System (INIS)

    Trifunac, A.D.

    1981-01-01

    Magnetic resonance methods in radiation chemistry are illustrated. The most recent developments in pulsed EPR and NMR studies in pulse radiolysis are outlined with emphasis on the study of transient radicals and their reaction products. 12 figures

  10. Influence of irradiation on reaction products of nitrite in foodstuffs

    International Nuclear Information System (INIS)

    Mirna, A.; Rau, G.

    1982-01-01

    Nitro alkanes and nitrolic acids are formed in foods by nitrosation reactions with nitrite. Among TEA-responsive compounds nitrolic acid behave to irradiation similar to N-nitrosamines. Some substances, extracted from spices, especially garlic, are also detectable by GC/TEA-chromatogramms of meat products and of reaction products from spices with nitrite show retention times not always clearly differentiated from those of NDMA, NDEA, NPIP and NPYR, respectively. Additional confirmation of such TEA positive compounds, therefore, is necessary. (orig.) [de

  11. Enhanced amylase production by fusarium solani in solid state fermentation

    International Nuclear Information System (INIS)

    Bakri, Y.; Jawhar, M.; Arabi, M.I.E.

    2014-01-01

    The present study illustrates the investigation carried out on the production of amylase by Fusarium species under solid state fermentation. All the tested Fusarium species were capable of producing amylase. A selected F. solani isolate SY7, showed the highest amylase production in solid state fermentation. Different substrates were screened for enzyme production. Among the several agronomic wastes, wheat bran supported the highest yield of amylase (141.18 U/g of dry substrate) after 3 days of incubation. Optimisation of the physical parameters revealed the optimum pH, temperature and moisture level for amylase production by the isolate as 8.0, 25 C and 70%, respectively. The above results indicate that the production of amylase by F. solani isolate SY7 could be improved by a further optimisation of the medium and culture conditions. (author)

  12. Energy conservation and maximal entropy production in enzyme reactions.

    Science.gov (United States)

    Dobovišek, Andrej; Vitas, Marko; Brumen, Milan; Fajmut, Aleš

    2017-08-01

    A procedure for maximization of the density of entropy production in a single stationary two-step enzyme reaction is developed. Under the constraints of mass conservation, fixed equilibrium constant of a reaction and fixed products of forward and backward enzyme rate constants the existence of maximum in the density of entropy production is demonstrated. In the state with maximal density of entropy production the optimal enzyme rate constants, the stationary concentrations of the substrate and the product, the stationary product yield as well as the stationary reaction flux are calculated. The test, whether these calculated values of the reaction parameters are consistent with their corresponding measured values, is performed for the enzyme Glucose Isomerase. It is found that calculated and measured rate constants agree within an order of magnitude, whereas the calculated reaction flux and the product yield differ from their corresponding measured values for less than 20 % and 5 %, respectively. This indicates that the enzyme Glucose Isomerase, considered in a non-equilibrium stationary state, as found in experiments using the continuous stirred tank reactors, possibly operates close to the state with the maximum in the density of entropy production. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Correlations between reaction product yields as a tool for probing heavy-ion reaction scenarios

    International Nuclear Information System (INIS)

    Gawlikowicz, W.; Agnihotri, D. K.; Baldwin, S. A.; Schroeder, W. U.; Toke, J.; Charity, R. J.; Sarantites, D. G.; Sobotka, L. G.; Souza, R. T. de; Barczyk, T.; Grotowski, K.; Micek, S.; Planeta, R.; Sosin, Z.

    2010-01-01

    Experimental multidimensional joint distributions of neutrons and charged reaction products were analyzed for 136 Xe + 209 Bi reactions at E/A=28, 40, and 62 MeV and were found to exhibit several different types of prominent correlation patterns. Some of these correlations have a simple explanation in terms of the system excitation energy and pose little challenge to most statistical decay theories. However, several other types of correlation patterns are difficult to reconcile with some, but not other, possible reaction scenarios. In this respect, correlations between the average atomic numbers of intermediate-mass fragments, on the one hand, and light particle multiplicities, on the other, are notable. This kind of multiparticle correlation provides a useful tool for probing reaction scenarios, which is different from the traditional approach of interpreting inclusive yields of individual reaction products.

  14. Product specific emissions from municipal solid waste landfills

    DEFF Research Database (Denmark)

    Nielsen, Per Henning; Exner, Stephan; Jørgensen, Anne-Mette

    1998-01-01

    This paper presents and verifies the computer tool LCA-LAND for estimation of emissions from specific waste products disposed in municipal solid waste landfills in European countries for use in the inventory analysis of LCA. Examples of input data (e.g. distribution of the waste product...... in different countries, composition of the product and physical/chemical/biological properties of waste product components) and output data (e.g. estimated emissions to atmosphere and water) are given for a fictive waste product made of representative types of components (toluene, cellulose, polyvinylchloride...... (PVC), copper and chloride). Since waste products from different processes in the product system may be disposed at different landfills where they are mixed with waste originating outside the product system, the estimated emissions from specific waste products cannot be compared with measured emissions...

  15. Preparation and Characterization of a Solid Acid Catalyst from Macro Fungi Residue for Methyl Palmitate Production

    Directory of Open Access Journals (Sweden)

    Min Wang

    2015-07-01

    Full Text Available During the process of fungal polysaccharide extraction for health care products and food factories, a large quantity of macro-fungi residues are produced, but most of the residues are abandoned and become environmental pollutants. A solid acid catalyst, prepared by sulfonating carbonized Phellinus igniarius residue, was shown to be an efficient and environmentally benign catalyst for the esterification of palmitate acid (PA and methanol. As a comparison, two types of common biomass catalysts, wheat straws and wood chips, were prepared. In this study, characterizations, including scanning electron microscopy, thermo-gravimetric analysis, Fourier transform infrared spectrometry, Brunauer-Emmett-Teller assays and elemental analysis, and reaction conditions for the synthesis of methyl palmitate (MP using solid acid catalysts were investigated. Experiments showed that the solid acid catalyst prepared from P. igniarius residue had a higher catalytic activity than the other two catalysts, and the highest yield of MP catalyzed by P. igniarius residue solid acid catalyst was 91.5% under the following optimum conditions: molar ratio of methanol/PA of 10:1, reaction temperature of 60 °C, mass ratio of catalyst/substrate of 2%, and a reaction time of 1.5 h. Thus, the use of this catalyst offers a method for producing MP.

  16. Production of gaseous or vaporous fuels from solid carbonaceous materials

    Energy Technology Data Exchange (ETDEWEB)

    1951-05-16

    A process for the production of gaseous or vaporous fuels from solid carbonaceous materials consists of subjecting the materials in separate zones to at least three successive thermal treatments at least two of which are carried out at different temperature levels. The materials being maintained in zones in the form of beds of finely divided particles fluidized by the passage of gases or vapors upwardly there-through, and recovering product vapors or gases overhead. The total hot gaseous or vaporous effluent and entrained solids from one of the zones is passed directly without separation to another of the zones situated closely adjacent to and vertically above the first named zone in the same vessel, and the heat required in at least one of the thermal treatment zones is supplied at least in part as the sensible heat of residual solids transferred from a thermal treatment zone operated at a higher temperature.

  17. Electrochemical characterisation of solid oxide cell electrodes for hydrogen production

    DEFF Research Database (Denmark)

    Bernuy-Lopez, Carlos; Knibbe, Ruth; He, Zeming

    2011-01-01

    Oxygen electrodes and steam electrodes are designed and tested to develop improved solid oxide electrolysis cells for H2 production with the cell support on the oxygen electrode. The electrode performance is evaluated by impedance spectroscopy testing of symmetric cells at open circuit voltage (OCV...

  18. Banana peel: A novel substrate for cellulase production under solid ...

    African Journals Online (AJOL)

    use

    2011-12-05

    Dec 5, 2011 ... The feasibility of using banana peel for the production of cellulase by Trichoderma viride GIM 3.0010 in solid-state fermentation was evaluated in this study. The effect of incubation time, incubation temperature, initial moisture content of the medium, inoculum size and supplementation of carbon sources ...

  19. Separation of volatile products from solid carbonaceous materials

    Energy Technology Data Exchange (ETDEWEB)

    White, W W

    1915-10-19

    A process is set forth for the separation of volatile products from solid carbonaceous materials, in which the vapors produced from the carbonaceous material at higher temperatures and withdrawn into the separate vapor chamber are led in succession through the lower temperature vapors as continuously to deposit their condensible ingredients in the chamber by the action of the successive cooler vapors.

  20. Production of lignin peroxidase by Ganoderma leucidum using solid ...

    African Journals Online (AJOL)

    The main objectives of this study were to optimize the culture conditions for the production of lignin peroxidase by Ganoderma leucidum, economic utilization of waste corn cobs as inducers substrate by pollution free fermentation technology and to optimize the solid state fermentation (SSF) process for lignin peroxidase ...

  1. Lovastatin production by Aspergillus terreus in solid state and ...

    African Journals Online (AJOL)

    At submerged cultivation of A. terreus 4 and A. terreus 20 on five different glucose and lactose based media the highest titer of lovastatin has been obtained on lactose based media, namely 276 mg/l and 236 mg/l, respectively. Five various types of bran have been tested as solid substrates for production of lovastatin in SSF ...

  2. Amylase production under solid state fermentation by a bacterial ...

    African Journals Online (AJOL)

    This study was concerned with the screening of a suitable isolate and optimization of cultural conditions for the biosynthesis of thermostable amylase under solid state fermentation (SSF). Twenty seven isolates were screened for amylase production out of which one isolate designated as W74 showed maximal amylase ...

  3. Solid-wood production from temperate eucalypt plantations: a ...

    African Journals Online (AJOL)

    Since 1988, there has been a major focus in Tasmania on research for the management of temperate eucalypt plantations for solid wood. This coincided with the formal transfer of large areas of native forest that had previously been part of the production forest estate into reserves, a decision that triggered the establishment ...

  4. Catalytic reaction in a porous solid subject to a boundary layer flow

    Energy Technology Data Exchange (ETDEWEB)

    Mihail, R; Teddorescu, C

    1978-01-01

    A mathematical model of a boundary layer flowing past a catalytic slab was developed which included an analysis of the coupled mass and heat transfer and the heterogeneous chemical reaction. The porous flat plate was used to illustrate the interaction of boundary layer flow with chemical reaction within a porous catalytic body. The model yielded systems of transcendental equations which were solved numerically by means of a superposition integral in connection with a norm reduction procedure. A parametric study was conducted and an analysis of the possible multiplicity of steady states was developed and illustrated for the extreme case of infinite solid thermal conductivity. Tables, diagrams, graphs, and 12 references.

  5. Growth behavior of LiMn{sub 2}O{sub 4} particles formed by solid-state reactions in air and water vapor

    Energy Technology Data Exchange (ETDEWEB)

    Kozawa, Takahiro, E-mail: t-kozawa@jwri.osaka-u.ac.jp [Joining and Welding Research Institute, Osaka University, 11–1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan); Yanagisawa, Kazumichi [Research Laboratory of Hydrothermal Chemistry, Faculty of Science, Kochi University, 2–5-1 Akebono-cho, Kochi 780-8520 (Japan); Murakami, Takeshi; Naito, Makio [Joining and Welding Research Institute, Osaka University, 11–1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan)

    2016-11-15

    Morphology control of particles formed during conventional solid-state reactions without any additives is a challenging task. Here, we propose a new strategy to control the morphology of LiMn{sub 2}O{sub 4} particles based on water vapor-induced growth of particles during solid-state reactions. We have investigated the synthesis and microstructural evolution of LiMn{sub 2}O{sub 4} particles in air and water vapor atmospheres as model reactions; LiMn{sub 2}O{sub 4} is used as a low-cost cathode material for lithium-ion batteries. By using spherical MnCO{sub 3} precursor impregnated with LiOH, LiMn{sub 2}O{sub 4} spheres with a hollow structure were obtained in air, while angulated particles with micrometer sizes were formed in water vapor. The pore structure of the particles synthesized in water vapor was found to be affected at temperatures below 700 °C. We also show that the solid-state reaction in water vapor is a simple and valuable method for the large-scale production of particles, where the shape, size, and microstructure can be controlled. - Graphical abstract: This study has demonstrated a new strategy towards achieving morphology control without the use of additives during conventional solid-state reactions by exploiting water vapor-induced particle growth. - Highlights: • A new strategy to control the morphology of LiMn{sub 2}O{sub 4} particles is proposed. • Water vapor-induced particle growth is exploited in solid-state reactions. • The microstructural evolution of LiMn{sub 2}O{sub 4} particles is investigated. • The shape, size and microstructure can be controlled by solid-state reactions.

  6. Growth behavior of LiMn2O4 particles formed by solid-state reactions in air and water vapor

    International Nuclear Information System (INIS)

    Kozawa, Takahiro; Yanagisawa, Kazumichi; Murakami, Takeshi; Naito, Makio

    2016-01-01

    Morphology control of particles formed during conventional solid-state reactions without any additives is a challenging task. Here, we propose a new strategy to control the morphology of LiMn 2 O 4 particles based on water vapor-induced growth of particles during solid-state reactions. We have investigated the synthesis and microstructural evolution of LiMn 2 O 4 particles in air and water vapor atmospheres as model reactions; LiMn 2 O 4 is used as a low-cost cathode material for lithium-ion batteries. By using spherical MnCO 3 precursor impregnated with LiOH, LiMn 2 O 4 spheres with a hollow structure were obtained in air, while angulated particles with micrometer sizes were formed in water vapor. The pore structure of the particles synthesized in water vapor was found to be affected at temperatures below 700 °C. We also show that the solid-state reaction in water vapor is a simple and valuable method for the large-scale production of particles, where the shape, size, and microstructure can be controlled. - Graphical abstract: This study has demonstrated a new strategy towards achieving morphology control without the use of additives during conventional solid-state reactions by exploiting water vapor-induced particle growth. - Highlights: • A new strategy to control the morphology of LiMn 2 O 4 particles is proposed. • Water vapor-induced particle growth is exploited in solid-state reactions. • The microstructural evolution of LiMn 2 O 4 particles is investigated. • The shape, size and microstructure can be controlled by solid-state reactions.

  7. Solid-state polymerisation via [2+2] cycloaddition reaction involving coordination polymers.

    Science.gov (United States)

    Medishetty, Raghavender; Park, In-Hyeok; Lee, Shim Sung; Vittal, Jagadese J

    2016-03-14

    Highly crystalline metal ions containing organic polymers are potentially useful to manipulate the magnetic and optical properties to make advanced multifunctional materials. However, it is challenging to synthesise monocrystalline metal complexes of organic polymers and single-phase hybrid materials made up of both coordination and organic polymers by traditional solution crystallisation. This requires an entirely different approach in the solid-state by thermal or photo polymerisation of the ligands. Among the photochemical methods available, [2+2] cycloaddition reaction has been recently employed to generate cyclobutane based coordination polymers from the metal complexes. Cyclobutane polymers have also been integrated into coordination polymers in this way. Recent advancements in the construction of polymeric chains of cyclobutane rings through photo-dimerisation reaction in the monocrystalline solids containing metal complexes, coordination polymers and metal-organic framework structures are discussed here.

  8. Petrographic characterization of the solid products of coal- pitch coprocessing

    Energy Technology Data Exchange (ETDEWEB)

    Potter, J.; Kybett, B.D.; McDougall, W.J.; Nambudiri, E.M.V.; Rahimi, P.; Price, J.T.

    1986-06-01

    Petrographic studies were conducted on four solid residues resulting from the hydrogenation process of 1) Forestburg sub- bituminous coal alone, 2) the coal with a non-coking solvent (anthracene oil), 3) pitch (Cold Lake vacuum-bottom deposits), and 4) a mixture of coal and pitch. The purpose was to determine the amounts of coal and pitch-derived solids in the residues. All the residues were produced under identical severe conditions of liquefaction to promote the formation of solids. The coal processed with anthracene oil gives a residue consisting mainly of isotropic huminitic solids. If the coal is hydrogenated under similar conditions but without a solvent, the predominant residual solids are anisotropic semicokes displaying coarse mosaic textures, which form from vitroplast. The residual products from the hydrogenated Cold Lake vacuum- bottom deposits are also dominantly anisotropic semicokes; these display coarse mosaics and flow textures, and form by the growth and coalescence of mesophase spherules. Both coal- and pitch-derived solids are identified in a residue produced by coprocessing the Forestburg coal with the pitch from the Cold Lake vacuum-bottom deposits. It is concluded that the huminite macerals in the coal generate the fine-grained, mosaic-textured semicokes, whereas the pitch produces the coarse mosaics and flow-textured semicokes.

  9. Electricity production from municipal solid waste in Brazil.

    Science.gov (United States)

    Nordi, Guilherme Henrique; Palacios-Bereche, Reynaldo; Gallego, Antonio Garrido; Nebra, Silvia Azucena

    2017-07-01

    Brazil has an increasing production of municipal solid waste that, allied to the current waste management system, makes the search for alternatives of energy recovery essential. Thus, this work aims to study the incineration of municipal solid waste and the electricity production through steam cycles evaluating the influence of municipal solid waste composition. Several scenarios were studied, in which it was assumed that some fractions of municipal solid waste were removed previously. The municipal solid waste generated in Santo André city, São Paulo State, Brazil, was adopted for this study. Simulation results showed that the removal of organic matter and inert components impacts advantageously on the cycle performance, improving their parameters in some cases; in addition, there is the possibility of reusing the separated fractions. The separation of some recyclables, as plastic material, showed disadvantages by the reduction in the electricity generation potential owing to the high calorific value of plastics. Despite the high energy content of them, there are other possible considerations on this subject, because some plastics have a better recovery potential by recycling.

  10. Production and Innovative Applications of Cryogenic Solid Pellets

    International Nuclear Information System (INIS)

    Baylor, L.R.; Combs, S.K.; Fisher, P.W.; Foster, C.A.; Foust, C.R.; Gouge, M.J.; Milora, S.L.

    1999-01-01

    For over two decades Oak Ridge National Laboratory has been developing cryogenic pellet injectors for fueling hot, magnetic fusion plasmas. Cryogenic solid pellets of all three hydrogen isotopes have been produced in a size range of 1- to 10-mm diameter and accelerated to speeds from <100 to ∼3000 m/s. The pellets have been formed discretely by cryocondensation in gun barrels and also by extrusion of cryogenic solids at mass flow rates up to ∼0.26 g/s and production rates up to ten pellets per second. The pellets traverse the hot plasma in a fraction of a millisecond and continuously ablate, providing fresh hydrogenic fuel to the interior of the plasma. From this initial application, uses of this technology have expanded to include (1) cryogenic xenon drops or solids for use as a debris-less target in a laser plasma source of X-rays for advanced lithography systems, (2) solid argon and carbon dioxide pellets for surface cleaning or decontamination, and (3) methane pellets in a liquid hydrogen bath for use as an innovative moderator of cold neutrons. Methods of production and acceleration/transport of these cryogenic solids will be described, and examples will be given of their use in prototype systems

  11. Duff reaction on phenols: Characterization of non steam volatile products

    Digital Repository Service at National Institute of Oceanography (India)

    Wahidullah, S.; DeSouza, L.; Bhattacharya, J.

    New products having structures 1 and 2 have been characterized in the Duff reaction thymol arid carvacrol. These products have been identified as 2.6'-dithymylmethane 1 and 5.5' -dicarvacryl methane 2 respectively on the basis of spectral data...

  12. Secondary Metabolites Production by Solid-State Fermentation

    Directory of Open Access Journals (Sweden)

    Barrios-González, J.

    2005-01-01

    Full Text Available Microbial secondary metabolites are useful high value products with an enormous range of biological activities. Moreover, the past two decades have been a phase of rapid discovery of new activities and development of major compounds for use in different industrial fields, mainly pharmaceuticals, cosmetics, food, agriculture and farming. Many of these metabolites could be produced advantageously in industry by solid–state fermentation (SSF. Two types of SSF can be distinguished, depending on the nature of the solid phase used: 1 Solid cultures of one support-substrate phase in which solid phase is constituted by a material that assumes, simultaneously, the functions of support and of nutrients source; and 2 Solid cultures of two substrate-support phases: solid phase is constituted by an inert support impregnated with a liquid medium. Besides good production performance, two phases systems have provided a convenient model for basic studies. Studies in our laboratory, as well as in others, have shown that physiology of idiophase (production phase in SSF share several similarities with the physiology in liquid medium, so similar strategies must be adapted for efficient production processes. However, our studies indicate the need to develop special strains for SSF since overproducing strains, generated for liquid fermentation, cannot be relied upon to perform well in SSF. On the other hand, there are important parameters, specific for SSF, that have to be optimized (pretreatment, initial moisture content, medium concentration and aeration. Respiration studies of secondary metabolites SSF, performed in our laboratory, have shown more subtle aspects of efficient production in SSF. This indicates that there are certain particularities of physiology in SSF that represent the point that needs a better understanding, and that promise to generate knowledge that will be the basis for efficient processes development and control strategies, as well as for

  13. Mass formula dependence of calculated spallation reaction product distributions

    International Nuclear Information System (INIS)

    Nishida, Takahiko; Nakahara, Yasuaki

    1990-01-01

    A new version of the spallation reaction simulation code NUCLEUS was developed by incorporating Uno and Yamada's mass formula. This version was used to calculate the distribution of products from the spallation of uranium nuclei by high-energy protons. The dependence of the distributions on the mass formula was examined by comparing the results with those from the original version, which is based on Cameron's mass formula and the mass table compiled by Wapstra et al. As regards the fission component of spallation products, the new version reproduces the reaction product data obtained from thin foil experiments much better, especially on the neutron excess side. (orig.) [de

  14. Chemical Characterization and Reactivity of Fuel-Oxidizer Reaction Product

    Science.gov (United States)

    David, Dennis D.; Dee, Louis A.; Beeson, Harold D.

    1997-01-01

    Fuel-oxidizer reaction product (FORP), the product of incomplete reaction of monomethylhydrazine and nitrogen tetroxide propellants prepared under laboratory conditions and from firings of Shuttle Reaction Control System thrusters, has been characterized by chemical and thermal analysis. The composition of FORP is variable but falls within a limited range of compositions that depend on three factors: the fuel-oxidizer ratio at the time of formation; whether the composition of the post-formation atmosphere is reducing or oxidizing; and the reaction or post-reaction temperature. A typical composition contains methylhydrazinium nitrate, ammonium nitrate, methylammonium nitrate, and trace amounts of hydrazinium nitrate and 1,1-dimethylhydrazinium nitrate. Thermal decomposition reactions of the FORP compositions used in this study were unremarkable. Neither the various compositions of FORP, the pure major components of FORP, nor mixtures of FORP with propellant system corrosion products showed any unusual thermal activity when decomposed under laboratory conditions. Off-limit thruster operations were simulated by rapid mixing of liquid monomethylhydrazine and liquid nitrogen tetroxide in a confined space. These tests demonstrated that monomethylhydrazine, methylhydrazinium nitrate, ammonium nitrate, or Inconel corrosion products can induce a mixture of monomethylhydrazine and nitrogen tetroxide to produce component-damaging energies. Damaging events required FORP or metal salts to be present at the initial mixing of monomethylhydrazine and nitrogen tetroxide.

  15. Prospects of Optical Single Atom Detection in Noble Gas Solids for Measurements of Rare Nuclear Reactions

    Science.gov (United States)

    Singh, Jaideep; Bailey, Kevin G.; Lu, Zheng-Tian; Mueller, Peter; O'Connor, Thomas P.; Xu, Chen-Yu; Tang, Xiaodong

    2013-04-01

    Optical detection of single atoms captured in solid noble gas matrices provides an alternative technique to study rare nuclear reactions relevant to nuclear astrophysics. I will describe the prospects of applying this approach for cross section measurements of the ^22Ne,,),25Mg reaction, which is the crucial neutron source for the weak s process inside of massive stars. Noble gas solids are a promising medium for the capture, detection, and manipulation of atoms and nuclear spins. They provide stable and chemically inert confinement for a wide variety of guest species. Because noble gas solids are transparent at optical wavelengths, the guest atoms can be probed using lasers. We have observed that ytterbium in solid neon exhibits intersystem crossing (ISC) which results in a strong green fluorescence (546 nm) under excitation with blue light (389 nm). Several groups have observed ISC in many other guest-host pairs, notably magnesium in krypton. Because of the large wavelength separation of the excitation light and fluorescence light, optical detection of individual embedded guest atoms is feasible. This work is supported by DOE, Office of Nuclear Physics, under contract DE-AC02-06CH11357.

  16. Synthesising and comparing electrical properties of NTC thermistors prepared from nano powder and solid state reaction

    International Nuclear Information System (INIS)

    Azad, N.; Ghanbari Shohany, B.; Hosseini, S. M.; Kompany, A.

    2011-01-01

    In this research, NTC thermistors with composition of NiMn 2-x Co x O 4 (x = 0.4, 0.8, 1.2, 1.6) prepared by two methods: solid state reaction and sol-gel (gel-combustion). The average particle size was monitored and structure of the calcinated powders have been investigated using x-ray diffraction and tunneling electron microscopy techniques. The average particle size was estimated to be about 65 nm with the cubic and cubic + tetragonal phases for low and high cobalt concentrations, respectively. The grain size of samples verifies with scanning electron microscopy images. Upon increasing the cobalt fraction, the grain size of samples increases from about 2μm to a few μm in size. The electrical properties of these thermistors depend on the grain size. The grain size of samples made from sol-gel is smaller than from solid state reaction under the same condition. For longer sintering time of the samples prepared by gel-combustion method, the grain size was increased then the electrical parameters of nano powder improved and we obtain better results than the samples prepared from solid state reaction.

  17. Product specific emissions from municipal solid waste landfills

    DEFF Research Database (Denmark)

    Nielsen, Per Henning; Hauschild, Michael Zwicky

    1998-01-01

    For the inventory analysis of environmental impacts associated with products in LCA there is a great need for estimates of emissions from waste products disposed at municipal solid waste landfills (product specific emissions). Since product specific emissions can not be calculated or measured...... directly at the landfills, they must be estimated by modelling of landfill processes. This paper presents a landfill model based on a large number of assumptions and approximations concerning landfill properties, waste product properties and characteristics of various kinds of environmental protection...... systems (e.g. landfill gas combustion units and leachate treatment units). The model is useful for estimation of emissions from waste products disposed in landfills and it has been made operational in the computer tool LCA-LAND presented in a following paper. In the model, waste products are subdivided...

  18. Catalytic activation of molecular hydrogen in alkyne hydrogenation reactions by lanthanide metal vapor reaction products

    International Nuclear Information System (INIS)

    Evans, W.J.; Bloom, I.; Engerer, S.C.

    1983-01-01

    A rotary metal vapor was used in the synthesis of Lu, Er, Nd, Sm, Yb, and La alkyne, diene, and phosphine complexes. A typical catalytic hydrogenation experiment is described. The lanthanide metal vapor product is dissolved in tetrahydrofuran or toluene and placed in a pressure reaction vessel 3-hexyne (or another substrate) is added, the chamber attached to a high vacuum line, cooled to -196 0 C, evacuated, warmed to ambient temperature and hydrogen is added. The solution is stirred magnetically while the pressure in monitored. The reaction products were analyzed by gas chromatography. Rates and products of various systems are listed. This preliminary survey indicates that catalytic reaction chemistry is available to these metals in a wide range of coordination environments. Attempts to characterize these compounds are hampered by their paramagnetic nature and their tendency to polymerize

  19. Quantifying atom addition reactions on amorphous solid water: a review of recent laboratory advances

    Science.gov (United States)

    He, Jiao; Vidali, Gianfranco

    2018-06-01

    Complex organic molecules found in space are mostly formed on and in the ice mantle covering interstellar dust grains. In clouds where ionizing irradiation is insignificant, chemical reactions on the ice mantle are dominated by thermal processes. Modeling of grain surface chemistry requires detailed information from the laboratory, including sticking coefficients, binding energies, diffusion energy barriers, mechanism of reaction, and chemical desorption rates. In this talk, recent laboratory advances in obtaining these information would be reviewed. Specifically, this talk will focus on the efforts in our group in: 1) Determining the mechanism of atomic hydrogen addition reactions on amorphous solid water (ASW); 2) Measuring the chemical desorption coefficient of H+O3-->O2+OH using the time-resolved scattering technique; and 3) Measuring the diffusion energy barrier of volatile molecules on ASW. Further laboratory studies will be suggested.This research was supported by NSF Astronomy & Astrophysics Research Grant #1615897.

  20. Production of fungal antibiotics using polymeric solid supports in solid-state and liquid fermentation.

    Science.gov (United States)

    Bigelis, Ramunas; He, Haiyin; Yang, Hui Y; Chang, Li-Ping; Greenstein, Michael

    2006-10-01

    The use of inert absorbent polymeric supports for cellular attachment in solid-state fungal fermentation influenced growth, morphology, and production of bioactive secondary metabolites. Two filamentous fungi exemplified the utility of this approach to facilitate the discovery of new antimicrobial compounds. Cylindrocarpon sp. LL-Cyan426 produced pyrrocidines A and B and Acremonium sp. LL-Cyan416 produced acremonidins A-E when grown on agar bearing moist polyester-cellulose paper and generated distinctly different metabolite profiles than the conventional shaken or stationary liquid fermentations. Differences were also apparent when tenfold concentrated methanol extracts from these fermentations were tested against antibiotic-susceptible and antibiotic-resistant Gram-positive bacteria, and zones of inhibition were compared. Shaken broth cultures of Acremonium sp. or Cylindrocarpon sp. showed complex HPLC patterns, lower levels of target compounds, and high levels of unwanted compounds and medium components, while agar/solid support cultures showed significantly increased yields of pyrrocidines A and B and acremonidins A-E, respectively. This method, mixed-phase fermentation (fermentation with an inert solid support bearing liquid medium), exploited the increase in surface area available for fungal growth on the supports and the tendency of some microorganisms to adhere to solid surfaces, possibly mimicking their natural growth habits. The production of dimeric anthraquinones by Penicillium sp. LL-WF159 was investigated in liquid fermentation using various inert polymeric immobilization supports composed of polypropylene, polypropylene cellulose, polyester-cellulose, or polyurethane. This culture produced rugulosin, skyrin, flavomannin, and a new bisanthracene, WF159-A, after fermentation in the presence and absence of polymeric supports for mycelial attachment. The physical nature of the different support systems influenced culture morphology and relative

  1. Effect of the reaction medium on the properties of solid catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Boreskov, G.K.

    1980-01-01

    The effect of the reaction medium on the properties of solid catalysts, such as bulk or supported metals, alloys, or metal oxides, include variations in surface composition, structure, and catalytic properties due to catalyst interaction with the reactants. This interaction leads to the establishment of a steady state, which is determined by the composition of the reaction medium and temperature, but is independent of the initial state of the catalyst. This steady state for a catalyst of a given chemical composition is characterized by an approximately constant specific activity in most chemical reactions, which is almost independent of the preparation method, surface area, or crystal size of the catalyst. The structurally sensitive reactions, which occur only on limited segments of catalyst surface characterized by specific structures, are the exception. The effects of the variations in catalytic properties caused by the reaction medium on the steady-state and nonsteady-state reaction kinetics are also discussed based on the results obtained for oxidative dehydrogenation of 1-butene over an iron/antimony oxide catalyst.

  2. Tannase Production by Solid State Fermentation of Cashew Apple Bagasse

    Science.gov (United States)

    Podrigues, Tigressa H. S.; Dantas, Maria Alcilene A.; Pinto, Gustavo A. S.; Gonçalves, Luciana R. B.

    The ability of Aspergillus oryzae for the production of tannase by solid state fermentation was investigated using cashew apple bagasse (CAB) as substrate. The effect of initial water content was studied and maximum enzyme production was obtained when 60 mL of water was added to 100.0 g of CAB. The fungal strain was able to grow on CAB without any supplementation but a low enzyme activity was obtained, 0.576 U/g of dry substrate (gds). Optimization of process parameters such as supplementation with tannic acid, phosphorous, and different organic and inorganic nitrogen sources was studied. The addition of tannic acid affected the enzyme production and maximum tannase activity (2.40 U/gds) was obtained with 2.5% (w/w) supplementation. Supplementation with ammonium nitrate, peptone, and yeast extract exerted no influence on tannase production. Ammonium sulphate improved the enzyme production in 3.75-fold compared with control. Based on the experimental results, CAB is a promising substrate for solid state fermentation, enabling A. oryzae growth and the production of tannase, with a maximum activity of 3.42 U/gds and enzyme productivity of 128.5×10-3 U·gds -1·h-1.

  3. Sterochemical consequences of hydrogen exchange as a result of tritium atom reactions on solid aliphatic amino acids

    International Nuclear Information System (INIS)

    Ehrenkaufer, R.L.E.; Hembree, W.C.; Lieberman, S.; Wolf, A.P.

    1977-01-01

    The products of stereochemistry resulting from radicals generated by the interaction of tritium atoms with L-isoleucine and L-alloisoleucine in the solid phase were determined. Among the four possible tritiated stereoisomers for each amino acid the major product was the parent L-amino acid (approximately 70 percent in each case) with the major fraction of the labeling being in positions other than the α position. Approximately 30 percent of the labeling resulted in the diastereomeric product by reaction at either the α or β position, with the major pathway being β-inversion. The yield of products from α-carbon attack of L-isoleucine was minor (7.9 percent) and occurred with net retention. Labeling at the α-carbon of alloisoleucine was less than 1 percent. Tritiated glycine was formed from both amino acids by cleavage of the alkyl side chain. This may result from the excitation decomposition of the intermediates formed from recombination of α (or β) amino acid radicals with tritium. Determination of the stereochemical and chemical consequences of radical formation at chiral centers provides a sensitive probe for studying the consequences of tritium (hydrogen or deuterium) atom reactions

  4. Effect of reaction products on cathodic reduction of iodic acid

    International Nuclear Information System (INIS)

    Shtejnberg, G.V.; Urisson, N.A.; Revina, A.A.; Volod'ko, V.L.

    1988-01-01

    The effect of reaction products on kinetics of iodic acid reduction is investigated; reaction products are identified by the optical method. It is shown that although being similar from the qualitative viewpoint the effect on HIO 3 reduction of dissolved crystal and ''reduced'' iodine, certain quantitative differences take place, which are explained by the difference in their surface concentration. Explanation of certain sections of complex lgI, E-curve of HIO 3 reduction is given, in particular, advanced wave is related to the reduction from solution of unstable electroactive complex HIO 3 ) x (I 1 ) y or (HIO 3 ) x (I 2 ) y

  5. Solid state reaction in alumina nanoparticles/LZSA glass-ceramic composites

    International Nuclear Information System (INIS)

    Montedo, O.K.; Oliveira, A.N. de; Raupp-Pereira, F.

    2016-01-01

    Full text: The aim of this work is to present results related to solid state reactions on LZSA glass-ceramic composites containing alumina reinforcement nano-particles. A LZSA (Li2O-ZrO2-SiO2-Al2O3) glass-ceramic has been prepared by sintering of powders and characterized. Composites containing 0 to 77 vol.% of alumina nanoparticles (27-43 nm APS, 35 m2.g-1 SSA) and a 16.9Li2O•5.0ZrO2•65.1SiO2•8.6Al2O3 glass-ceramic matrix have been prepared. X-ray diffractometry studies have been performed in order of investigating the solid state reactions occurring in LZSA-based composites. Results of the XRD patterns have been related to the coefficient of thermal expansion (CTE), Young modulus, and dielectric constant, showing that, in comparison with the glass-ceramic composition, the composites showed a decrease of CTE with the alumina concentration increasing, due to the increasing of beta-spodumeness formation (solid solution of beta-spodumene, Li2O.Al2O3.4-10SiO2). The performance of the glass-ceramic was improved with the alumina nano-particles addition, showing potential of using in the preparation of Low Thermal Co-fired Ceramics (LTCC). (author)

  6. The study of biodiesel production using CaO as a heterogeneous catalytic reaction

    Directory of Open Access Journals (Sweden)

    Kamila Colombo

    2017-06-01

    Full Text Available With the aim of developing a process of biodiesel production that is environmentally benign much interest has been focused on the use of solid base catalysts, such as calcium oxide, for the transesterification of vegetable oils with methanol. In the study reported herein a recycling reactor was used in bench scale, with the capacity to produce 3 L of biodiesel. The reactor was designed especially for this research study. A full 23 factorial plan was used to evaluate the process parameters related to this study, in particular, the catalyst concentration, the alcohol to oil molar ratio and the reaction time. Using this equipment for the transesterification reaction resulted in the recovery of the excess alcohol. The reaction products were characterized using gas chromatography and liquid analysis to determine the ester and calcium concentrations, respectively. The main conclusions drawn were that the best conversion percentage (100% of biodiesel was reached when the methanol:oil molar ratio was 6:1, the reaction time was 75 min and the catalyst mass was 3% in relation to the oil mass used in this process. The CaO concentration determined exceeded the limit of concentration defined by legislation and thus a secondary operation was carried out to purify the reaction products obtained. The results of this study showed a high performance, and the proposed experiment could be used as a new and innovative way to produce biodiesel in the future.

  7. Excipient Usage Technical Risk Assessment for Generic Solid Dose Products

    Directory of Open Access Journals (Sweden)

    Ajay Babu Pazhayattil

    2017-09-01

    Full Text Available This paper proposes an assessment methodology for solid dose generic small molecule drug products. It addresses the ‘usage of the excipient’ portion of the trinomial by utilizing the systematic approach of Risk Identification, Risk Analysis and Risk Evaluation as per ICH Q9 Quality Risk Management outlined for developing risk control strategies. The assessment and maintenance of excipient risk profile is essential to minimize any potential risk associated to excipients impacting patients.

  8. Effectiveness and reaction networks of H2O2 vapor with NH3 gas for decontamination of the toxic warfare nerve agent, VX on a solid surface.

    Science.gov (United States)

    Gon Ryu, Sam; Wan Lee, Hae

    2015-01-01

    The nerve agent, O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothioate (VX) must be promptly eliminated following its release into the environment because it is extremely toxic, can cause death within a few minutes after exposure, acts through direct skin contact as well as inhalation, and persists in the environment for several weeks after release. A mixture of hydrogen peroxide vapor and ammonia gas was examined as a decontaminant for the removal of VX on solid surfaces at ambient temperature, and the reaction products were analyzed by gas chromatography-mass spectrometry (GC-MS) and nuclear magnetic resonance spectrometry (NMR). All the VX on glass wool filter disks was found to be eliminated after 2 h of exposure to the decontaminant mixtures, and the primary decomposition product was determined to be non-toxic ethyl methylphosphonic acid (EMPA); no toxic S-[2-(diisopropylamino)ethyl] methylphosphonothioic acid (EA-2192), which is usually produced in traditional basic hydrolysis systems, was found to be formed. However, other by-products, such as toxic O-ethyl S-vinyl methylphosphonothioate and (2-diisopropylaminoethyl) vinyl disulfide, were detected up to 150 min of exposure to the decontaminant mixture; these by-products disappeared after 3 h. The two detected vinyl byproducts were identified first in this study with the decontamination system of liquid VX on solid surfaces using a mixture of hydrogen peroxide vapor and ammonia gas. The detailed decontamination reaction networks of VX on solid surfaces produced by the mixture of hydrogen peroxide vapor and ammonia gas were suggested based on the reaction products. These findings suggest that the mixture of hydrogen peroxide vapor and ammonia gas investigated in this study is an efficient decontaminant mixture for the removal of VX on solid surfaces at ambient temperature despite the formation of a toxic by-product in the reaction process.

  9. Solid state reaction studies in Fe3O4–TiO2 system by diffusion couple method

    International Nuclear Information System (INIS)

    Ren, Zhongshan; Hu, Xiaojun; Xue, Xiangxin; Chou, Kuochih

    2013-01-01

    Highlights: •The solid state reactions of Fe2O3-TiO2 system was studied by the diffusion couple method. •Different products were formed by diffusion, and the FeTiO3 was more stable phase. •The inter-diffusion coefficients and diffusion activation energy were estimated. -- Abstract: The solid state reactions in Fe 3 O 4 –TiO 2 system has been studied by diffusion couple experiments at 1323–1473 K, in which the oxygen partial pressure was controlled by the CO–CO 2 gas mixture. The XRD analysis was used to confirm the phases of the inter-compound, and the concentration profiles were determined by electron probe microanalysis (EPMA). Based on the concentration profile of Ti, the inter-diffusion coefficients in Fe 3 O 4 phase, which were both temperature and concentration of Ti ions dependent, were calculated by the modified Boltzmann–Matano method. According to the relation between the thickness of diffusion layer and temperature, the diffusion coefficient of the Fe 3 O 4 –TiO 2 system was obtained. According to the Arrhenius equation, the estimated diffusion activation energy was about 282.1 ± 18.8 kJ mol −1

  10. The quantitative monitoring of mechanochemical reaction between solid L-tartaric acid and sodium carbonate monohydrate by terahertz spectroscopy

    Science.gov (United States)

    Liu, Xiaohong; Liu, Guifeng; Zhao, Hongwei; Zhang, Zengyang; Wei, Yongbo; Liu, Min; Wen, Wen; Zhou, Xingtai

    2011-11-01

    The solid-state reaction of chiral tartaric acid and alkali carbonate was studied by terahertz time-domain spectroscopy (THz-TDS). The sodium tartrate dihydrate was synthesized with high efficiency by mechanical grinding in the solid-state without waste that is particularly sustainable and environmentally benign. Distinct THz absorptions were observed for reactants and products. It indicates that THz spectroscopy is sensitive to different materials and crystal structures. The characteristic THz absorption peak at 1.09 THz of L (+)-Tartaric acid was selected for quantitative analysis. The reaction kinetics could be expressed by the Second-order equation and the Jander equation, which is consistent with a three-dimensional diffusion mechanism. The combination of multi-techniques including synchrotron radiation X-ray powder diffraction (SRXRPD), Fourier transform infrared (FT-IR) and scanning electron microscopy (SEM) was used to investigate the grinding process and presented supporting evidences. The results demonstrate that THz spectroscopy technique has great potential applications in process monitoring and analysis in pharmaceutical and chemical synthesis industry.

  11. A Monte Carlo simulation of the exchange reaction between gaseous molecules and the atoms on a heterogeneous solid surface

    International Nuclear Information System (INIS)

    Imai, Hisao

    1980-01-01

    A method of the Monte Carlo simulation of the isotopic exchange reaction between gaseous molecules and the atoms on an arbitrarily heterogeneous solid surface is described by employing hydrogen as an example. (author)

  12. Production behavior of irradiation defects in solid breeder materials

    Energy Technology Data Exchange (ETDEWEB)

    Moriyama, Hirotake; Moritani, Kimikazu [Kyoto Univ. (Japan)

    1998-03-01

    The irradiation effects in solid breeder materials are important for the performance assessment of fusion reactor blanket systems. For a clearer understanding of such effects, we have studied the production behavior of irradiation defects in some lithium ceramics by an in-situ luminescence measurement technique under ion beam irradiation. The luminescence spectra were measured at different temperatures, and the temperature-transient behaviors of luminescence intensity were also measured. The production mechanisms of irradiation defects were discussed on the basis of the observations. (author)

  13. Stochastic aspects of multiparticle production in relativistic nuclear reactions

    International Nuclear Information System (INIS)

    Tachung, M.

    1988-01-01

    Midrapidity multiparticle production process in ordinary hadron and heavy-ion induced reactions at sufficiently high incident energies are analyzed. It is shown that stochastic aspects of multiparticle production process in relativistic range plays a dominating role in understanding the observable phenomena. The basic idea and the main results of the multisource model for hadron-nucleus and nucleus-nucleus collisions are shown. The concept of the NES (number of effective sources) scaling is discussed. 16 refs.; 7 figs

  14. Charged Porous Polymers using a Solid C-O Cross-Coupling Reaction

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Pengfei; Jiang, Xueguang; Wan, Shun; Dai, Sheng

    2015-07-15

    Here in this paper, we report a green, fast, efficient mechanochemical strategy for charged porous polymers (CPPs). A cationic CPP with basic anions and an anionic CPP with Li+ cations were fabricated by solid grinding under solvent-free conditions. Compared with solution-based synthesis, mechanochemical grinding can shorten the reaction time from dozens of hours to several minutes (60–90 min) to form polymers possessing a high molecular mass and low polydispersity. During the construction of CPPs, a Pd-catalyzed solid polycondensation based on unactivated organic linkers was introduced. In particular, CPPs with basic phenolic or proline anions showed good activity and stability in SO2 capture, and Li+-functionalized CPPs can be post-modified to CPPs with other metal ions by ion exchange, highlighting the tailorable feature of ionic-modified CPPs.

  15. Charged Porous Polymers using a Solid C-O Cross-Coupling Reaction

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Pengfei; Jiang, Xueguang; Wan, Shun; Dai, Sheng

    2015-07-15

    Herein, we report a green, fast, efficient mechanochemical strategy for charged porous polymers (CPPs). A cationic CPP with basic anions and an anionic CPP with Li+ cations were fabricated by solid grinding under solvent-free conditions. Compared with solution-based synthesis, mechanochemical grinding can shorten the reaction time from dozens of hours to several minutes (60–90 min) to form polymers possessing a high molecular mass and low polydispersity. During the construction of CPPs, a Pd-catalyzed solid polycondensation based on unactivated organic linkers was introduced. In particular, CPPs with basic phenolic or proline anions showed good activity and stability in SO2 capture, and Li+-functionalized CPPs can be post-modified to CPPs with other metal ions by ion exchange, highlighting the tailorable feature of ionic-modified CPPs.

  16. The production of high energy neutrons by secondary reactions

    International Nuclear Information System (INIS)

    Nieschmidt, E.B.; Roney, T.J.; Staples, D.R.; Harmon, J.F.; Burkhart, J.H.

    1994-01-01

    The potential of using binary reactions in targets containing Be is discussed. Data are presented from the use of Be and BeF 2 targets bombarded with 1.5, 1.7, 1.8 and 1.9 MeV protons. Neutron production is enhanced by the presence of the F by factors of ∼4

  17. Two-pion production in photon-induced reactions

    Indian Academy of Sciences (India)

    A deeper understanding of the situation is anticipated from a detailed experimental study of meson photoproduction from nuclei in exclusive reactions. In the energy regime above the (1232) resonance, the dominant double pion production channels are of particular interest. Double pion photoproduction from nuclei is ...

  18. BIG-10 fission product generation and reaction rates

    International Nuclear Information System (INIS)

    Rogers, J.W.

    1976-01-01

    Fission product generation rates for high quality fission foils and reaction rates of nonfission foils have been measured by gamma ray activation analyses. These foils were irradiated in the BIG-10 facility and the activities were measured by NaI counting techniques

  19. Reaction products of densified silica fume agglomerates in concrete

    International Nuclear Information System (INIS)

    Diamond, Sidney; Sahu, Sadananda; Thaulow, Niels

    2004-01-01

    Most silica fume currently used in concrete is in the dry densified form and consists of agglomerates of sizes between 10 μm and several millimeters. Many of these agglomerates may break down only partially in normal concrete mixing. Examination of various mature silica-fume-bearing concretes using backscatter mode scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) analysis shows that such agglomerates have reacted in situ and given rise to recognizable types of reaction products filling the space within the original outline of the agglomerate. One type is 'quiescent', and usually shows no evidence of volume instability. EDX spectra indicate that the product formed within such grains is C-S-H of very low Ca/Si ratio, with modest alkali contents. Other silica fume agglomerates may undergo a distinct alkali-silica-type reaction (ASR), with the reaction product found within the original outline of the agglomerate having significantly less calcium and usually much higher alkali contents than the quiescent type. Such reacted agglomerates show evidence of local expansion, shrinkage cracking (on drying), and other features common to ASR. Both types may be found within the same concrete, sometimes in close proximity. It further appears that exposure to seawater may convert previously formed reaction products of silica fume agglomerates to magnesium silicate hydrates

  20. Fission-product SiC reaction in HTGR fuel

    International Nuclear Information System (INIS)

    Montgomery, F.

    1981-01-01

    The primary barrier to release of fission product from any of the fuel types into the primary circuit of the HTGR are the coatings on the fuel particles. Both pyrolytic carbon and silicon carbide coatings are very effective in retaining fission gases under normal operating conditions. One of the possible performance limitations which has been observed in irradiation tests of TRISO fuel is chemical interaction of the SiC layer with fission products. This reaction reduces the thickness of the SiC layer in TRISO particles and can lead to release of fission products from the particles if the SiC layer is completely penetrated. The experimental section of this report describes the results of work at General Atomic concerning the reaction of fission products with silicon carbide. The discussion section describes data obtained by various laboratories and includes (1) a description of the fission products which have been found to react with SiC; (2) a description of the kinetics of silicon carbide thinning caused by fission product reaction during out-of-pile thermal gradient heating and the application of these kinetics to in-pile irradiation; and (3) a comparison of silicon carbide thinning in LEU and HEU fuels

  1. Mass, energy and material balances of SRF production process. Part 3: solid recovered fuel produced from municipal solid waste.

    Science.gov (United States)

    Nasrullah, Muhammad; Vainikka, Pasi; Hannula, Janne; Hurme, Markku; Kärki, Janne

    2015-02-01

    This is the third and final part of the three-part article written to describe the mass, energy and material balances of the solid recovered fuel production process produced from various types of waste streams through mechanical treatment. This article focused the production of solid recovered fuel from municipal solid waste. The stream of municipal solid waste used here as an input waste material to produce solid recovered fuel is energy waste collected from households of municipality. This article presents the mass, energy and material balances of the solid recovered fuel production process. These balances are based on the proximate as well as the ultimate analysis and the composition determination of various streams of material produced in a solid recovered fuel production plant. All the process streams are sampled and treated according to CEN standard methods for solid recovered fuel. The results of the mass balance of the solid recovered fuel production process showed that 72% of the input waste material was recovered in the form of solid recovered fuel; 2.6% as ferrous metal, 0.4% as non-ferrous metal, 11% was sorted as rejects material, 12% as fine faction and 2% as heavy fraction. The energy balance of the solid recovered fuel production process showed that 86% of the total input energy content of input waste material was recovered in the form of solid recovered fuel. The remaining percentage (14%) of the input energy was split into the streams of reject material, fine fraction and heavy fraction. The material balances of this process showed that mass fraction of paper and cardboard, plastic (soft) and wood recovered in the solid recovered fuel stream was 88%, 85% and 90%, respectively, of their input mass. A high mass fraction of rubber material, plastic (PVC-plastic) and inert (stone/rock and glass particles) was found in the reject material stream. © The Author(s) 2014.

  2. PRODUCTION OF AN EXTRACELLULAR CELLOBIASE IN SOLID STATE FERMENTATION

    Directory of Open Access Journals (Sweden)

    Ruchi Agrawal

    2013-02-01

    Full Text Available The bioethanol production from lignocellulosic biomass has attracted wide interest globally in last decade. One of the main reasons for the high cost of bioethanol production from lignocellulosic biomass is the expensive enzymes involved in enzymatic hydrolysis of cellulose (cellulase. The utilization of agro-industrial waste as a potential substrate for producing enzymes may serve a dual purpose of reducing the environmental pollution along with producing a high value commercial product. Twelve different agro-industrial wastes were evaluated for extracellular cellobiose or β-glucosidase production by a mutant of Bacillus subtilis on solid state fermentations (SSF. The Citrus sinensis peel waste was found to be the most suitable substrate with highest BGL titre (35 U/gds. Optimum incubation time, inoculum size, moisture content and volume of buffer for enzyme extraction were 72 h, 40 % v/w, 10 mL and 20 mL respectively.

  3. Enhanced reversibility and durability of a solid oxide Fe-air redox battery by carbothermic reaction derived energy storage materials.

    Science.gov (United States)

    Zhao, Xuan; Li, Xue; Gong, Yunhui; Huang, Kevin

    2014-01-18

    The recently developed solid oxide metal-air redox battery is a new technology capable of high-rate chemistry. Here we report that the performance, reversibility and stability of a solid oxide iron-air redox battery can be significantly improved by nanostructuring energy storage materials from a carbothermic reaction.

  4. Elemental balance of SRF production process: solid recovered fuel produced from municipal solid waste.

    Science.gov (United States)

    Nasrullah, Muhammad; Vainikka, Pasi; Hannula, Janne; Hurme, Markku; Oinas, Pekka

    2016-01-01

    In the production of solid recovered fuel (SRF), certain waste components have excessive influence on the quality of product. The proportion of rubber, plastic (hard) and certain textiles was found to be critical as to the elemental quality of SRF. The mass flow of rubber, plastic (hard) and textiles (to certain extent, especially synthetic textile) components from input waste stream into the output streams of SRF production was found to play the decisive role in defining the elemental quality of SRF. This paper presents the mass flow of polluting and potentially toxic elements (PTEs) in SRF production. The SRF was produced from municipal solid waste (MSW) through mechanical treatment (MT). The results showed that of the total input chlorine content to process, 55% was found in the SRF and 30% in reject material. Of the total input arsenic content, 30% was found in the SRF and 45% in fine fraction. In case of cadmium, lead and mercury, of their total input content to the process, 62%, 38% and 30%, respectively, was found in the SRF. Among the components of MSW, rubber material was identified as potential source of chlorine, containing 8.0 wt.% of chlorine. Plastic (hard) and textile components contained 1.6 and 1.1. wt.% of chlorine, respectively. Plastic (hard) contained higher lead and cadmium content compared with other waste components, i.e. 500 mg kg(-1) and 9.0 mg kg(-1), respectively. © The Author(s) 2015.

  5. Theory of nuclear reactions with participation of slow charged particles in solids

    International Nuclear Information System (INIS)

    Barts, B.I.; Barts, D.B.; Grinenko, A.A.

    1992-01-01

    In the last two years, there has been a sharp increase of interest in various aspects of the interaction of nuclear particles in solids. This is due, above all, to the sensational reports of the possibility that deuteron fusion reactions take place at normal temperatures. At the present time, it is clear that, among the various factors, an important role for the understanding of this remarkable phenomenon is played by crystal fields that significantly change the tail of the Coulomb barrier and, thus, its penetrability. Here, in connection with the problem of the cold fusion of deuterons, an analysis is made of the influence of screening of the deuteron charges by electrons of the crystal on the penetrability of the Coulomb barrier. A study is made of the reaction-enhancement method in the case when the deuterons move in the general crystal potential well near one of the minima of the crystal potential

  6. Urban solid waste in the production of Lafoensia pacari seedlings

    Directory of Open Access Journals (Sweden)

    Alan H. M. de Abreu

    Full Text Available ABSTRACT This study aimed to verify the potential of urban solid wastes as substrate for production of seedlings of Lafoensia pacari. Five treatments were tested, four with solid wastes and one standard substrate, namely: sewage sludge from Alegria Wastewater Treatment Plant (WTP; sewage sludge from Ilha do Governador WTP; sewage sludge from Sarapuí WTP; domestic garbage compost (Fertlurb; and a commercial substrate made of biostabilized pine bark (standard substrate. The wastes received 20% (in volume of shredded coconut fiber. At 105 days after sowing, the seedlings were evaluated for different quality parameters. Seedlings produced with Sarapuí WTP sewage sludge showed the best results in all the parameters, followed by seedlings produced with sewage sludge from Alegria and Ilha do Governador WTPs, which did not differ. Seedlings produced with domestic garbage compost showed satisfactory results, higher than the ones observed for seedlings produced with commercial substrate. The urban solid wastes with 20% of coconut fiber showed high potential and can be recommended for the composition of substrate in the production of Lafoensia pacari seedlings.

  7. Stochastic thermodynamics and entropy production of chemical reaction systems

    Science.gov (United States)

    Tomé, Tânia; de Oliveira, Mário J.

    2018-06-01

    We investigate the nonequilibrium stationary states of systems consisting of chemical reactions among molecules of several chemical species. To this end, we introduce and develop a stochastic formulation of nonequilibrium thermodynamics of chemical reaction systems based on a master equation defined on the space of microscopic chemical states and on appropriate definitions of entropy and entropy production. The system is in contact with a heat reservoir and is placed out of equilibrium by the contact with particle reservoirs. In our approach, the fluxes of various types, such as the heat and particle fluxes, play a fundamental role in characterizing the nonequilibrium chemical state. We show that the rate of entropy production in the stationary nonequilibrium state is a bilinear form in the affinities and the fluxes of reaction, which are expressed in terms of rate constants and transition rates, respectively. We also show how the description in terms of microscopic states can be reduced to a description in terms of the numbers of particles of each species, from which follows the chemical master equation. As an example, we calculate the rate of entropy production of the first and second Schlögl reaction models.

  8. Solid Culturing of Bacillus amyloliquefaciens for α-Amylase Production

    Directory of Open Access Journals (Sweden)

    Dhanya Gangadharan

    2006-01-01

    Full Text Available Fourteen different agroresidues were screened for alpha amylase production using Bacillus amyloliquefaciens ATCC 23842. Among them, wheat bran (WB and groundnut oil cake (GOC in mass ratio of 1:1 was proved as the best substrate source. Supplementation with 0.01 M KH2PO4 and 1 % soluble starch enhanced the enzyme yield considerably. Maximum enzyme recovery from the solid mass was obtained when extracted with 0.1 M acetate buffer, pH=5.0. Maximum enzyme titer expressed as units per mass of dry substrate obtained was 62 470 U/g after 72 hours of fermentation at 37 °C by using the above solid substrate mixture (5 g with the initial moisture of 85 % and inoculated with Bacillus amyloliquefaciens of 2·109 CFU/mL.

  9. Synthesis and regulation of α-LiZnPO4.H2O via a solid-state reaction at low-heating temperatures

    International Nuclear Information System (INIS)

    Liao Sen; Chen Zhipeng; Tian Xiaozhen; Wu Wenwei

    2009-01-01

    A simple and novel route for the synthesis of a lithium zinc phosphate hydrate, α-LiZnPO 4 .H 2 O, was studied, and the target product was obtained with LiH 2 PO 4 .H 2 O and ZnCO 3 as raw materials and polyethylene glycol-400 (PEG-400) as a surfactant via a one step solid-state reaction at room temperature (25 deg. C). The product was characterized with X-ray powder diffraction (XRD), thermogravimetric analysis and the 1st derivativative of thermogravimetric analysis (TG/DTG) and Fourier transform infrared spectroscopy (FTIR). The comparison experimental results suggested that aging temperature controlled the products of the synthesis, that is, the α-LiZnPO 4 .H 2 O was formed when the reaction mixture was aged at room temperature, and the α-LiZnPO 4 was obtained when the reaction mixture was aged at 80 deg. C.

  10. Solid targets for production of radioisotopes with cyclotron; Blancos solidos para produccion de radioisotopos con ciclotron

    Energy Technology Data Exchange (ETDEWEB)

    Paredes G, L.; Balcazar G, M. [Instituto Nacional de Investigaciones Nucleares, Direccion de Investigacion Tecnologica, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1999-07-01

    The design of targets for production of radioisotopes and radiopharmaceuticals of cyclotron to medical applications requires a detailed analysis of several variables such as: cyclotron operation conditions, choice of used materials as target and their physicochemical characteristics, activity calculation, the yielding of each radioisotope by irradiation, the competition of nuclear reactions in function of the projectiles energy and the collision processes amongst others. The objective of this work is to determine the equations for the calculation for yielding of solid targets at the end of the proton irradiation. (Author)

  11. 1-4 Strangeness Production in Antiproton Induced Nuclear Reactions.

    Institute of Scientific and Technical Information of China (English)

    Feng; Zhaoqing[1

    2014-01-01

    More localized energy deposition is able to be produced in antiproton-nucleus collisions in comparison withheavy-ion collisions due to annihilation reactions. Searching for the cold quark-gluon plasma (QGP) with antiprotonbeamshas been considered as a hot topic both in experiments and in theretical calculations over the past severaldecades. Strangeness production and hypernucleus formation in antiproton-induced nuclear reactions are importancein exploring the hyperon (antihyperon)-nucleon (HN) potential and the antinucleon-nucleon interaction, whichhave been hot topics in the forthcoming experiments at PANDA in Germany.

  12. Studying reaction products in a lithium thionyl chloride cell

    International Nuclear Information System (INIS)

    Vol'fkovich, Yu.M.; Sosenkin, V.E.; Nikol'skaya, N.F.; Blinov, I.A.

    1999-01-01

    Change in the mass, volume and chemical composition of reaction insoluble products (RIP) formed in the course of discharge of thionyl chloride lithium cells under different conditions has been studied by the methods of gravimetry, volumetry and element analysis. It has been ascertained that the measured volume and mass of RIP essentially (by a factor of 1.1-1.8) exceed the calculated values, proceeding from the reaction stoichiometry. Besides lithium chloride and sulfur during discharge additional RIP is formed as LiAlCl 4 · SOCl 2 solvate, its share increasing with temperature decrease, increase in current density and electrolyte concentration [ru

  13. Identification of reaction products from reactions of free chlorine with the lipid-regulator gemfibrozil.

    Science.gov (United States)

    Krkošek, Wendy H; Koziar, Stephen A; White, Robert L; Gagnon, Graham A

    2011-01-01

    High global consumption rates have led to the occurrence of pharmaceutically active compounds (PhACs) in wastewater. The use of chlorine to disinfect wastewater prior to release into the environment may convert PhACs into uncharacterized chlorinated by-products. In this investigation, chlorination of a common pharmaceutical, the antihyperlipidemic agent gemfibrozil, was documented. Gemfibrozil (2,2-dimethyl-5-(2,5-dimethylphenoxy)pentanoic acid) was reacted with sodium hypochlorite and product formation was monitored by gas chromatography-mass spectrometry (GC-MS). The incorporation of one, two or three chlorine atoms into the aromatic region of gemfibrozil was demonstrated using negative-ion electrospray ionization mass spectrometry (ESI-MS) and tandem mass spectrometry (ESI-MS/MS). Further analysis using (1)H nuclear magnetic resonance (NMR) spectroscopy identified the reaction products as 4'-ClGem (5-(4-chloro-2,5-dimethylphenoxy)-2,2-dimethylpentanoic acid) 4',6'-diClGem (5-(4,6-dichloro-2,5-dimethylphenoxy)-2,2-dimethylpentanoic acid), and 3',4',6'-triClGem (5-(3,4,6-trichloro-2,5-dimethylphenoxy)-2,2-dimethylpentanoic acid), products consistent with electrophilic aromatic substitution reactions. The rapid reaction of gemfibrozil with free chlorine at pH conditions relevant to water treatment indicates that a mixture of chlorinated gemfibrozils is likely to be found in wastewater disinfected with chlorine. Copyright © 2010 Elsevier Ltd. All rights reserved.

  14. Ag_3PO_4 Microcrystals Synthesized by Room-Temperature Solid State Reaction: Enhanced Photocatalytic Activity and Photoelectronchemistry Performance

    International Nuclear Information System (INIS)

    Hao Chen-Chun; Xu Jie; Shi Hong-Long; Fu Jun-Li; Zou Bin; Meng Shan; Wang Wen-Zhong; Jia Ying

    2015-01-01

    Ag_3PO_4 microcrystals with highly enhanced visible light photocatalytic activity are prepared by a facile and simple solid state reaction at room temperature. The composition, morphology and optical properties of the as-prepared Ag_3PO_4 microcrystals are characterized by x-ray diffraction, scanning electron microscopy and UV-vis diffuse reflectance spectra. The photocatalytic properties of Ag_3PO_4 are investigated by the degradation of both methylene blue and methyl orange dyes under visible light irradiation. The as-prepared Ag_3PO_4 microcrystals possess high photocatalytic oxygen production with the rate of 673 μmolh"−"1 g"−"1. Moreover, the as-prepared Ag_3PO_4 microcrystals show an enhanced photoelectrochemistry performance under irradiation of visible light. (paper)

  15. Organic photochemical reactions on solid surfaces: Enrichment and separation of isotopes. Final report. SBIR-1988, Phase 2

    International Nuclear Information System (INIS)

    Ruderman, W.; Fehlner, J.; Spencer, J.

    1988-01-01

    The objectives of the Phase II program were to: (1) investigate organic photochemical reactions on solid porous silica surfaces, (2) utilize the magnetic isotope effect to develop a (13)C enrichment process using a fluidized bed reactor, and (3) investigate the possibility of enrichment of heavier isotopes having a nuclear spin. Although researchers were able to demonstrate a continuous fluidized bed (13)C enrichment process, analysis showed that the process could not compete with low temperature distillation of CO because of the high cost of the starting material, dibenzylketone (DBK), and the difficulty of converting the photochemical decomposition products back to DBK. However, the process shows promise for the separation of heavier isotopes such as (29)Si. The photochemical studies led to the discovery that the selectivity for terminal chlorination of alkanes can be increased more than 25 fold by sorbing the alkanes on ZSM-5 zeolites in a fluidized bed. The selectivity is ascribed to the presence of interfaces within the crystals

  16. Golden rule kinetics of transfer reactions in condensed phase: The microscopic model of electron transfer reactions in disordered solid matrices

    Science.gov (United States)

    Basilevsky, M. V.; Odinokov, A. V.; Titov, S. V.; Mitina, E. A.

    2013-12-01

    The algorithm for a theoretical calculation of transfer reaction rates for light quantum particles (i.e., the electron and H-atom transfers) in non-polar solid matrices is formulated and justified. The mechanism postulated involves a local mode (an either intra- or inter-molecular one) serving as a mediator which accomplishes the energy exchange between the reacting high-frequency quantum mode and the phonon modes belonging to the environment. This approach uses as a background the Fermi golden rule beyond the usually applied spin-boson approximation. The dynamical treatment rests on the one-dimensional version of the standard quantum relaxation equation for the reduced density matrix, which describes the frequency fluctuation spectrum for the local mode under consideration. The temperature dependence of a reaction rate is controlled by the dimensionless parameter ξ0 = ℏω0/kBT where ω0 is the frequency of the local mode and T is the temperature. The realization of the computational scheme is different for the high/intermediate (ξ0 conduction in photosensitive organic materials is considered, based on the above techniques. The electron transfer (ET) in active centers of such systems proceeds via local intra- and intermolecular modes. The active modes, as a rule, operate beyond the kinetic regimes, which are usually postulated in the existing theories of the ET. Our alternative dynamic ET model for local modes immersed in the continuum harmonic medium is formulated for both classical and quantum regimes, and accounts explicitly for the mode/medium interaction. The kinetics of the energy exchange between the local ET subsystem and the surrounding environment essentially determine the total ET rate. The efficient computer code for rate computations is elaborated on. The computations are available for a wide range of system parameters, such as the temperature, external field, local mode frequency, and characteristics of mode/medium interaction. The relation of the

  17. Study of Ni/Si(1 0 0) solid-state reaction with Al addition

    International Nuclear Information System (INIS)

    Huang Yifei; Jiang Yulong; Ru Guoping; Li Bingzong

    2008-01-01

    The characteristics of Ni/Si(1 0 0) solid-state reaction with Al addition (Ni/Al/Si(1 0 0), Ni/Al/Ni/Si(1 0 0) and Al/Ni/Si(1 0 0)) is studied. Ni and Al films were deposited on Si(1 0 0) substrate by ion beam sputtering. The solid-state reaction between metal films and Si was performed by rapid thermal annealing. The sheet resistance of the formed silicide film was measured by four-point probe method. The X-ray diffraction (XRD) was employed to detect the phases in the silicide film. The Auger electron spectroscopy was applied to reveal the element profiles in depth. The influence of Al addition on the Schottky barrier heights of the formed silicide/Si diodes was investigated by current-voltage measurements. The experimental results show that NiSi forms even with the addition of Al, although the formation temperature correspondingly changes. It is revealed that Ni silicidation is accompanied with Al diffusion in Ni film toward the film top surface and Al is the dominant diffusion species in Ni/Al system. However, no Ni x Al y phase is detected in the films and no significant Schottky barrier height modulation by the addition of Al is observed

  18. Behavior of solid fission products in irradiated fuel

    International Nuclear Information System (INIS)

    Song, Ung Sup; Jung, Yang Hong; Kim, Hee Moon; Yoo, Byun Gok; Kim, Do Sik; Choo, Yong Sun; Hong, Kwon Pyo

    2004-01-01

    Many fission products are generated by fission events in UO 2 fuel under irradiation in nuclear reactor. Concentration of each fission product is changed by conditions of neutron energy spectrum, fissile material, critical thermal power, irradiation period and cooling time. Volatile materials such as Cs and I, the fission products, degrade nuclear fuel rod by the decrease of thermal conductivity in pellet and the stress corrosion cracking in cladding. Metal fission products (white inclusion) make pellet be swelled and decrease volume of pellet by densification. It seems that metal fission products are filled in the pore in pellet and placed between UO 2 lattices as interstitial. In addition, metal oxide state may change structural lattice volume. Considering behavior of fission products mentioned above, concentration of them is important. Fission products could be classified as bellows; solid solution in matrix : Sr, Zr, Nb, Y, La, Ce, Pr, Nd, Pm, Sm - metal precipitates : Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sb, Te - oxide precipitates : Ba, Zr, Nb, Mo, (Rb, Cs, Te) - volatile and gases : Kr, Xe, Br, I, (Rb, Cs, Te)

  19. Maillard reaction products from chitosan-xylan ionic liquid solution.

    Science.gov (United States)

    Luo, Yuqiong; Ling, Yunzhi; Wang, Xiaoying; Han, Yang; Zeng, Xianjie; Sun, Runcang

    2013-10-15

    A facile method is reported to prepare Maillard reaction products (MRPs) from chitosan and xylan in co-solvent ionic liquid. UV absorbance and fluorescence changes were regarded as indicators of the occurrence of Maillard reaction. FT-IR, NMR, XRD and TG were used to investigate the structure of chitosan-xylan conjugate. The results revealed that when chitosan reacted with xylan in ionic liquid, the hydrogen bonds in chitosan were destroyed, the facts resulted in the formation of chitosan-xylan MRPs. Moreover, when the mass ratio of chitosan to xylan was 1:1, the Maillard reaction proceeded easily. In addition, relatively high antioxidant property was also noted for the chitosan-xylan conjugate with mass ratio 1:1. So the obtained chitosan-xylan MRP is a promising antioxidant agent for food industry. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Use of Incineration Solid Waste Bottom Ash as Cement Mixture in Cement Production

    Science.gov (United States)

    Jun, N. H.; Abdullah, M. M. A. B.; Jin, T. S.; Kadir, A. A.; Tugui, C. A.; Sandu, A. V.

    2017-06-01

    Incineration solid waste bottom ash was use to examine the suitability as a substitution in cement production. This study enveloped an innovative technology option for designing new equivalent cement that contains incineration solid waste bottom ash. The compressive strength of the samples was determined at 7, 14, 28 and 90 days. The result was compared to control cement with cement mixture containing incineration waste bottom ash where the result proved that bottom ash cement mixture able achieve its equivalent performance compared to control cement which meeting the requirement of the standards according to EN 196-1. The pozzolanic activity index of bottom ash cement mixture reached 0.92 at 28 days and 0.95 at 90 and this values can be concluded as a pozzolanic material with positive pozzolanic activity. Calcium hydroxide in Portland cement decreasing with the increasing replacement of bottom ash where the reaction occur between Ca(OH)2 and active SiO2.

  1. Thermophilic cellulase production by Taralomyces sp. in solid-state cultivation

    Energy Technology Data Exchange (ETDEWEB)

    Nishio, N; Kurisu, H; Nagai, S

    1981-01-01

    The effects of substrate moisture content and culture temperature on the production of carboxymethyl cellulase (CMCase) and avicel hydrolyzing activity (avicelase) by Taralomyces sp. were studied in solid state cultivation using wheat bran. The moisture content of wheat bran was maintained at 40, 45, 50, 55 and 58/sup 0/C throughout the solid state cultures. The maximum avicelase formation was observed when the substrate moisture content and the culture temperature were maintained at 60% and 45/sup 0/C, respectively. The maximum CMCase formation was observed when the moisture content was maintained between 60 and 70% at 50/sup 0/C. Optimum reaction temperatures of CMCase and avicelase were 80 and 60/sup 0/C, respectively.

  2. [Fission product yields of 60 fissioning reactions]. Final report

    International Nuclear Information System (INIS)

    Rider, B.F.

    1995-01-01

    In keeping with the statement of work, I have examined the fission product yields of 60 fissioning reactions. In co-authorship with the UTR (University Technical Representative) Talmadge R. England ''Evaluation and Compilation of Fission Product Yields 1993,'' LA-UR-94-3106(ENDF-349) October, (1994) was published. This is an evaluated set of fission product Yields for use in calculation of decay heat curves with improved accuracy has been prepared. These evaluated yields are based on all known experimental data through 1992. Unmeasured fission product yields are calculated from charge distribution, pairing effects, and isomeric state models developed at Los Alamos National Laboratory. The current evaluation has been distributed as the ENDF/B-VI fission product yield data set

  3. Methane productivity of manure, straw and solid fractions of manure

    DEFF Research Database (Denmark)

    Møller, H.B.; Sommer, S.G.; Ahring, Birgitte Kiær

    2004-01-01

    are in the same range (282-301 m(3) CH4 LU-1). Pre-treatment of manure by separation is a way of making fractions of the manure that have a higher gas potential per volume. Theoretical methane potential and biodegradability of three types of fractions deriving from manure separation were tested. The volumetric...... methane yield of straw was found to be higher than the yield from total manure and the solid fractions of manure, due to the higher VS content, and hence the use of straw as bedding material will increase the volumetric as well as the livestock-based methane productivity....

  4. Modifications of hemoglobin and myoglobin by Maillard reaction products (MRPs.

    Directory of Open Access Journals (Sweden)

    Aristos Ioannou

    Full Text Available High performance liquid chromatography (HPLC coupled with a Fraction Collector was employed to isolate Maillard reaction products (MRPs formed in model systems comprising of asparagine and monosaccharides in the 60-180°C range. The primary MRP which is detected at 60°C is important for Acrylamide content and color/aroma development in foods and also in the field of food biotechnology for controlling the extent of the Maillard reaction with temperature. The discrete fractions of the reaction products were reacted with Hemoglobin (Hb and Myoglobin (Mb at physiological conditions and the reaction adducts were monitored by UV-vis and Attenuated Total Reflection-Fourier transform infrared (FTIR spectrophotometry. The UV-vis kinetic profiles revealed the formation of a Soret transition characteristic of a low-spin six-coordinated species and the ATR-FTIR spectrum of the Hb-MRP and Mb-MRP fractions showed modifications in the protein Amide I and II vibrations. The UV-vis and the FTIR spectra of the Hb-MRPs indicate that the six-coordinated species is a hemichrome in which the distal E7 Histidine is coordinated to the heme Fe and blocks irreversibly the ligand binding site. Although the Mb-MRPs complex is a six-coordinated species, the 1608 cm-1 FTIR band characteristic of a hemichrome was not observed.

  5. Modifications of hemoglobin and myoglobin by Maillard reaction products (MRPs).

    Science.gov (United States)

    Ioannou, Aristos; Varotsis, Constantinos

    2017-01-01

    High performance liquid chromatography (HPLC) coupled with a Fraction Collector was employed to isolate Maillard reaction products (MRPs) formed in model systems comprising of asparagine and monosaccharides in the 60-180°C range. The primary MRP which is detected at 60°C is important for Acrylamide content and color/aroma development in foods and also in the field of food biotechnology for controlling the extent of the Maillard reaction with temperature. The discrete fractions of the reaction products were reacted with Hemoglobin (Hb) and Myoglobin (Mb) at physiological conditions and the reaction adducts were monitored by UV-vis and Attenuated Total Reflection-Fourier transform infrared (FTIR) spectrophotometry. The UV-vis kinetic profiles revealed the formation of a Soret transition characteristic of a low-spin six-coordinated species and the ATR-FTIR spectrum of the Hb-MRP and Mb-MRP fractions showed modifications in the protein Amide I and II vibrations. The UV-vis and the FTIR spectra of the Hb-MRPs indicate that the six-coordinated species is a hemichrome in which the distal E7 Histidine is coordinated to the heme Fe and blocks irreversibly the ligand binding site. Although the Mb-MRPs complex is a six-coordinated species, the 1608 cm-1 FTIR band characteristic of a hemichrome was not observed.

  6. Heating-induced inner-sphere substitution and reduction-oxidation reactions of the solid phenanthroline containing cobalt (2) and cobalt (3) complexes

    International Nuclear Information System (INIS)

    Palade, D.M.

    1996-01-01

    The results of the differential thermal and thermogravimetric analyses of solid phenanthroline-containing complexes of cobalt (2) and cobalt (3) in the atmosphere of the air have been analyzed. Mechanism of redox reactions occurring when cobalt (3) complexes are heated has been discussed. It is shown that some of gaseous products of the redox processes appear as a result of secondary reactions and not the processes of the ligands oxidation by Co 3+ . The influence of certain inner-sphere and coordinated anions (of I, inclusively) on cobalt (3) complexes behaviour during heating has been considered

  7. Products of the reaction between methylene iodide and tertiary arsines

    International Nuclear Information System (INIS)

    Gigauri, R.D.; Arabuli, L.G.; Machaidze, Z.I.; Rusiya, M.Sh.

    2005-01-01

    Iodides of iodomethylenetrialkyl(aryl) arsonium were synthesized with high yields as a result of interaction between methylene iodide and tertiary arsines. Exchange reactions of the iodides prepared with lead(II) nitrate in water-alcohol solutions gave rise to formation of iodomethylenetrialkyl(aryl) arsonium nitrates. All the products prepared were characterized by data of elementary analysis, IR spectroscopy, conductometry and melting points measurements [ru

  8. Reactions of newly formed fission products in the gas phase

    International Nuclear Information System (INIS)

    Strickert, R.G.

    1976-01-01

    A dynamic gas-flow system was constructed which stopped fission products in the gas phase and rapidly separated (in less than 2 sec) volatile compounds from non-volatile ones. The filter assembly designed and used was shown to stop essentially all non-volatile fission products. Between 5 percent and 20 percent of tellurium fission-product isotopes reacted with several hydrocarbon gases to form volatile compounds, which passed through the filter. With carbon monoxide gas, volatile tellurium compound(s) (probably TeCO) were also formed with similar efficiencies. The upper limits for the yields of volatile compounds formed between CO and tin and antimony fission products were shown to be less than 0.3 percent, so tellurium nuclides, not their precursors, reacted with CO. It was found that CO reacted preferentially with independently produced tellurium atoms; the reaction efficiency of beta-produced atoms was only 27 +- 3 percent of that of the independently formed atoms. The selectivity, which was independent of the over-all reaction efficiency, was shown to be due to reaction of independently formed atoms in the gas phase. The gas phase reactions are believed to occur mainly at thermal energies because of the independence of the yield upon argon moderator mole-fraction (up to 80 percent). It was shown in some experiments that about one-half of the TeCO decomposed in passing through a filter and that an appreciable fraction (approximately 20 percent) of the tellurium atoms deposited on the filter reacted agin with CO. Other tellurium atoms on the filter surface (those formed by beta decay and those formed independently but not reacting in the gas phase) also reacted with CO, but probably somewhat less efficiently than atoms formed by TeCO decomposition. No evidence was found for formation of TeCO as a direct result of beta-decay

  9. Formation kinetics of gemfibrozil chlorination reaction products: analysis and application.

    Science.gov (United States)

    Krkosek, Wendy H; Peldszus, Sigrid; Huck, Peter M; Gagnon, Graham A

    2014-07-01

    Aqueous chlorination kinetics of the lipid regulator gemfibrozil and the formation of reaction products were investigated in deionized water over the pH range 3 to 9, and in two wastewater matrices. Chlorine oxidation of gemfibrozil was found to be highly dependent on pH. No statistically significant degradation of gemfibrozil was observed at pH values greater than 7. Gemfibrozil oxidation between pH 4 and 7 was best represented by first order kinetics. At pH 3, formation of three reaction products was observed. 4'-C1Gem was the only reaction product formed from pH 4-7 and was modeled with zero order kinetics. Chlorine oxidation of gemfibrozil in two wastewater matrices followed second order kinetics. 4'-C1Gem was only formed in wastewater with pH below 7. Deionized water rate kinetic models were applied to two wastewater effluents with gemfibrozil concentrations reported in literature in order to calculate potential mass loading rates of 4'C1Gem to the receiving water.

  10. Influence of transesterification reaction temperature on biodiesel production

    Energy Technology Data Exchange (ETDEWEB)

    Pighinelli, Anna Leticia Montenegro Turtelli; Zorzeto, Thais Queiroz; Park, Kil Jin [Universidade Estadual de Campinas (FEAGRI/UNICAMP), SP (Brazil). Fac. de Engenharia Agricola], E-mail: annalets@agr.unicamp.br; Bevilaqua, Gabriela [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Inst. de Quimica

    2008-07-01

    Brazilian government policy has authorized the introduction of biodiesel into the national energy matrix, law no.11.097 of January 13th, 2005. It is necessary, like any new product, to invest in research which is able to cover its entire production chain (planting of oilseeds, vegetable oils extraction and chemical reactions), providing data and relevant information in order to optimize the process and solve critical issues. The objective of this work was to study the effects of temperature on crude sunflower transesterification reaction with ethanol. A central composite experimental design with five variation levels (25 deg, 32 deg, 47.5 deg, 64 deg and 70 deg C) was used and response surface methodology applied for the data analysis. The statistical analysis of the results showed that the production suffered the influence of temperature (linear and quadratic effects) and reaction time (linear and quadratic). The generated models did not show significant regression. The model generated was not well suited to the experimental data and the value of the coefficient of determination (R{sup 2}=0.52) was low. Consequently it was not possible to build the response surface. (author)

  11. Golden rule kinetics of transfer reactions in condensed phase: The microscopic model of electron transfer reactions in disordered solid matrices

    International Nuclear Information System (INIS)

    Basilevsky, M. V.; Mitina, E. A.; Odinokov, A. V.; Titov, S. V.

    2013-01-01

    The algorithm for a theoretical calculation of transfer reaction rates for light quantum particles (i.e., the electron and H-atom transfers) in non-polar solid matrices is formulated and justified. The mechanism postulated involves a local mode (an either intra- or inter-molecular one) serving as a mediator which accomplishes the energy exchange between the reacting high-frequency quantum mode and the phonon modes belonging to the environment. This approach uses as a background the Fermi golden rule beyond the usually applied spin-boson approximation. The dynamical treatment rests on the one-dimensional version of the standard quantum relaxation equation for the reduced density matrix, which describes the frequency fluctuation spectrum for the local mode under consideration. The temperature dependence of a reaction rate is controlled by the dimensionless parameter ξ 0 =ℏω 0 /k B T where ω 0 is the frequency of the local mode and T is the temperature. The realization of the computational scheme is different for the high/intermediate (ξ 0 0 ≫ 1) temperature ranges. For the first (quasi-classical) kinetic regime, the Redfield approximation to the solution of the relaxation equation proved to be sufficient and efficient in practical applications. The study of the essentially quantum-mechanical low-temperature kinetic regime in its asymptotic limit requires the implementation of the exact relaxation equation. The coherent mechanism providing a non-vanishing reaction rate has been revealed when T→ 0. An accurate computational methodology for the cross-over kinetic regime needs a further elaboration. The original model of the hopping mechanism for electronic conduction in photosensitive organic materials is considered, based on the above techniques. The electron transfer (ET) in active centers of such systems proceeds via local intra- and intermolecular modes. The active modes, as a rule, operate beyond the kinetic regimes, which are usually postulated in the

  12. Golden rule kinetics of transfer reactions in condensed phase: The microscopic model of electron transfer reactions in disordered solid matrices

    Energy Technology Data Exchange (ETDEWEB)

    Basilevsky, M. V.; Mitina, E. A. [Photochemistry Center, Russian Academy of Sciences, 7a, Novatorov ul., Moscow (Russian Federation); Odinokov, A. V. [Photochemistry Center, Russian Academy of Sciences, 7a, Novatorov ul., Moscow (Russian Federation); National Research Nuclear University “MEPhI,” 31, Kashirskoye shosse, Moscow (Russian Federation); Titov, S. V. [Karpov Institute of Physical Chemistry, 3-1/12, Building 6, Obuha pereulok, Moscow (Russian Federation)

    2013-12-21

    The algorithm for a theoretical calculation of transfer reaction rates for light quantum particles (i.e., the electron and H-atom transfers) in non-polar solid matrices is formulated and justified. The mechanism postulated involves a local mode (an either intra- or inter-molecular one) serving as a mediator which accomplishes the energy exchange between the reacting high-frequency quantum mode and the phonon modes belonging to the environment. This approach uses as a background the Fermi golden rule beyond the usually applied spin-boson approximation. The dynamical treatment rests on the one-dimensional version of the standard quantum relaxation equation for the reduced density matrix, which describes the frequency fluctuation spectrum for the local mode under consideration. The temperature dependence of a reaction rate is controlled by the dimensionless parameter ξ{sub 0}=ℏω{sub 0}/k{sub B}T where ω{sub 0} is the frequency of the local mode and T is the temperature. The realization of the computational scheme is different for the high/intermediate (ξ{sub 0} < 1 − 3) and for low (ξ{sub 0}≫ 1) temperature ranges. For the first (quasi-classical) kinetic regime, the Redfield approximation to the solution of the relaxation equation proved to be sufficient and efficient in practical applications. The study of the essentially quantum-mechanical low-temperature kinetic regime in its asymptotic limit requires the implementation of the exact relaxation equation. The coherent mechanism providing a non-vanishing reaction rate has been revealed when T→ 0. An accurate computational methodology for the cross-over kinetic regime needs a further elaboration. The original model of the hopping mechanism for electronic conduction in photosensitive organic materials is considered, based on the above techniques. The electron transfer (ET) in active centers of such systems proceeds via local intra- and intermolecular modes. The active modes, as a rule, operate beyond the

  13. Golden rule kinetics of transfer reactions in condensed phase: the microscopic model of electron transfer reactions in disordered solid matrices.

    Science.gov (United States)

    Basilevsky, M V; Odinokov, A V; Titov, S V; Mitina, E A

    2013-12-21

    The algorithm for a theoretical calculation of transfer reaction rates for light quantum particles (i.e., the electron and H-atom transfers) in non-polar solid matrices is formulated and justified. The mechanism postulated involves a local mode (an either intra- or inter-molecular one) serving as a mediator which accomplishes the energy exchange between the reacting high-frequency quantum mode and the phonon modes belonging to the environment. This approach uses as a background the Fermi golden rule beyond the usually applied spin-boson approximation. The dynamical treatment rests on the one-dimensional version of the standard quantum relaxation equation for the reduced density matrix, which describes the frequency fluctuation spectrum for the local mode under consideration. The temperature dependence of a reaction rate is controlled by the dimensionless parameter ξ0 = ℏω0/k(B)T where ω0 is the frequency of the local mode and T is the temperature. The realization of the computational scheme is different for the high/intermediate (ξ0 regime, the Redfield approximation to the solution of the relaxation equation proved to be sufficient and efficient in practical applications. The study of the essentially quantum-mechanical low-temperature kinetic regime in its asymptotic limit requires the implementation of the exact relaxation equation. The coherent mechanism providing a non-vanishing reaction rate has been revealed when T → 0. An accurate computational methodology for the cross-over kinetic regime needs a further elaboration. The original model of the hopping mechanism for electronic conduction in photosensitive organic materials is considered, based on the above techniques. The electron transfer (ET) in active centers of such systems proceeds via local intra- and intermolecular modes. The active modes, as a rule, operate beyond the kinetic regimes, which are usually postulated in the existing theories of the ET. Our alternative dynamic ET model for local

  14. Mathematical modeling of ethanol production in solid-state fermentation based on solid medium' dry weight variation.

    Science.gov (United States)

    Mazaheri, Davood; Shojaosadati, Seyed Abbas; Zamir, Seyed Morteza; Mousavi, Seyyed Mohammad

    2018-04-21

    In this work, mathematical modeling of ethanol production in solid-state fermentation (SSF) has been done based on the variation in the dry weight of solid medium. This method was previously used for mathematical modeling of enzyme production; however, the model should be modified to predict the production of a volatile compound like ethanol. The experimental results of bioethanol production from the mixture of carob pods and wheat bran by Zymomonas mobilis in SSF were used for the model validation. Exponential and logistic kinetic models were used for modeling the growth of microorganism. In both cases, the model predictions matched well with the experimental results during the exponential growth phase, indicating the good ability of solid medium weight variation method for modeling a volatile product formation in solid-state fermentation. In addition, using logistic model, better predictions were obtained.

  15. SOLID-STATE FERMENTATIVE PRODUCTION AND BIOACTIVITY OF FUNGAL CHITOSAN

    Directory of Open Access Journals (Sweden)

    Barry Aigbodion Omogbai

    2013-10-01

    Full Text Available Chitosan production was investigated using a laboratory-scale solid substrate fermentation (SSF technique with four species of fungi: Penicillium expansum, Aspergillus niger, Rhizopus oryzae and Fusarium moniliforme.The peak growth for the organisms was after 16 days. Aspergillus niger had the highest growth with a maximal dry cell biomass of 15.8g/kg after 16 days cultivation on corn straw under solid substrate fermentation. This was closely followed by Rhizopus oryzae (14.6g/kg, Penicillium expansum (13.8g/kg and Fusarium moniliforme (10.6g/kg respectively. The fungus Rhizopus oryzae had the highest chitosan production with a maximum of 8.57g/kg in 16 days under solid substrate fermentation (SSF with a medium containing corn straw. Aspergillus niger showed a modest chitosan yield of 6.8g/kg. Penicillium expansum and Fusarium moniliforme had low chitosan yields of 4.31g/kg and 3.1g/kg respectively. The degree of deacetylation of fungal chitosans ranged between 75.3-91.5% with a viscosity of 3.6-7.2 centipoises (Cp.Chitosan extracted from Rhizopus oryzae was found to have antibacterial activity on some bacterial isolates. At a concentration of 50mg/L, Rhizopus oryzae chitosan paralleled crab chitosan in susceptibility testing against some food-borne bacterial pathogens. Escherichia coli, Salmonella typhi, Pseudomonas aeruginosa and Bacillus subtilis showed inhibition rates of 83.2%, 67.9%, 63.8% and 62.4% respectively in response to 50mg/l Rhizopus oryzae chitosan in 24 h. The rate of inhibition (% increased with increase in chitosan concentration.

  16. Coupling Solid Oxide Electrolyser (SOE) and ammonia production plant

    International Nuclear Information System (INIS)

    Cinti, Giovanni; Frattini, Domenico; Jannelli, Elio; Desideri, Umberto; Bidini, Gianni

    2017-01-01

    Highlights: • An innovative NH 3 production plant was designed. • CO 2 emissions and energy consumption are studied in three different designs. • High temperature electrolysis allows to achieve high efficiency and heat recovery. • The coupling permits storage of electricity into a liquid carbon free chemical. - Abstract: Ammonia is one of the most produced chemicals worldwide and is currently synthesized using nitrogen separated from air and hydrogen from natural gas reforming with consequent high consumption of fossil fuel and high emission of CO 2 . A renewable path for ammonia production is desirable considering the potential development of ammonia as energy carrier. This study reports design and analysis of an innovative system for the production of green ammonia using electricity from renewable energy sources. This concept couples Solid Oxide Electrolysis (SOE), for the production of hydrogen, with an improved Haber Bosch Reactor (HBR), for ammonia synthesis. An air separator is also introduced to supply pure nitrogen. SOE operates with extremely high efficiency recovering high temperature heat from the Haber-Bosch reactor. Aspen was used to develop a model to study the performance of the plant. Both the SOE and the HBR operate at 650 °C. Ammonia production with zero emission of CO 2 can be obtained with a reduction of 40% of power input compared to equivalent plants.

  17. A study on production of biodiesel using a novel solid oxide catalyst derived from waste.

    Science.gov (United States)

    Majhi, Samrat; Ray, Srimanta

    2016-05-01

    The issues of energy security, dwindling supply and inflating price of fossil fuel have shifted the global focus towards fuel of renewable origin. Biodiesel, having renewable origin, has exhibited great potential as substitute for fossil fuels. The most common route of biodiesel production is through transesterification of vegetable oil in presence of homogeneous acid or base or solid oxide catalyst. But, the economics of biodiesel is not competitive with respect to fossil fuel due to high cost of production. The vegetable oil waste is a potential alternative for biodiesel production, particularly when disposal of used vegetable oil has been restricted in several countries. The present study evaluates the efficacy of a low-cost solid oxide catalyst derived from eggshell (a food waste) in transesterification of vegetable oil and simulated waste vegetable oil (SWVO). The impact of thermal treatment of vegetable oil (to simulate frying operation) on transesterification using eggshell-derived solid oxide catalyst (ESSO catalyst) was also evaluated along with the effect of varying reaction parameters. The study reported that around 90 % biodiesel yield was obtained with vegetable oil at methanol/oil molar ratio of 18:1 in 3 h reaction time using 10 % ESSO catalyst. The biodiesel produced with ESSO catalyst from SWVO, thermally treated at 150 °C for 24 h, was found to conform with the biodiesel standard, but the yield was 5 % lower compared to that of the untreated oil. The utilization of waste vegetable oil along with waste eggshell as catalyst is significant for improving the overall economics of the biodiesel in the current market. The utilization of waste for societal benefit with the essence of sustainable development is the novelty of this work.

  18. Chemical transport reactions

    CERN Document Server

    Schäfer, Harald

    2013-01-01

    Chemical Transport Reactions focuses on the processes and reactions involved in the transport of solid or liquid substances to form vapor phase reaction products. The publication first offers information on experimental and theoretical principles and the transport of solid substances and its special applications. Discussions focus on calculation of the transport effect of heterogeneous equilibria for a gas motion between equilibrium spaces; transport effect and the thermodynamic quantities of the transport reaction; separation and purification of substances by means of material transport; and

  19. Production and decay of baryonic resonances in pion induced reactions

    Directory of Open Access Journals (Sweden)

    Przygoda Witold

    2016-01-01

    Full Text Available Pion induced reactions give unique opportunities for an unambiguous description of baryonic resonances and their coupling channels. A systematic energy scan and high precision data, in conjunction with a partial wave analysis, allow for the study of the excitation function of the various contributions. A review of available world data unravels strong need for modern facilities delivering measurements with a pion beam. Recently, HADES collaboration collected data in pion-induced reactions on light (12C and heavy (74W nuclei at a beam momentum of 1.7 GeV/c dedicated to strangeness production. It was followed by a systematic scan at four different pion beam momenta (0.656, 0.69, 0.748 and 0.8 GeV/c in π− − p reaction in order to tackle the role of N(1520 resonance in conjunction with the intermediate ρ production. First results on exclusive channels with one pion (π− p and two pions (nπ+π−, pπ−π0 in the final state are discussed.

  20. Plasma fluctuations and confinement of fusion reaction products

    International Nuclear Information System (INIS)

    Coppi, B.; Pegoraro, F.

    1981-01-01

    The interaction between the fluctuations that can be excited in a magnetically confined plasma and the high-energy-particle population produced by fusion reactions is analyzed in view of its relevance to the process of thermonuclear ignition. The spectrum of the perturbations that, in the absence of fusion reaction products, would be described by the incompressible ideal magnetohydrodynamic approximation is studied considering finite value of the plasma pressure relative ot the magnetic pressure. The combined effects of the magnetic field curvature and shear are taken into account and the relevant spectrum is shown to consist of a continuous portion, that could be identified as a mixture of shear-Alfven and interchange oscillations, and a discrete unstable part corresponding to the so-called ballooning modes. The rate of diffusion of the fusion reaction products induced by oscillations in the continuous part of the spectrum, as estimated from the appropriate quasi-linear theory, is found to be significantly smaller than could be expected if normal modes (i.e., nonconvective solutions) were excited. However, a relatively wide intermediate region is identified where opalescent fluctuations, capable of achieving significant amplitudes and corresponding to a quasi-discrete spectrum, can be excited

  1. Maillard Reaction in Natural Rubber Latex: Characterization and Physical Properties of Solid Natural Rubber

    Directory of Open Access Journals (Sweden)

    S. Montha

    2016-01-01

    Full Text Available Maillard reaction in Natural Rubber (NR latex was investigated by treating fresh NR latex with glutaraldehyde (C5H8O2 in amounts of 0, 50, 100, and 200 mmol/kg of latex. Protein cross-linking in fresh NR latex and solid NR was confirmed by using sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE and attenuated total reflection infrared (ATR-IR spectroscopy, respectively. It was found that degree of protein cross-linking in NR increased with increasing C5H8O2 concentration. Physical properties of untreated and treated NR substances in terms of gel content, initial Wallace plasticity (P0, plasticity retention index (PRI, Mooney viscosity, and tensile strength were carefully explored. Results clearly showed that the Maillard cross-linking of proteins had remarkable effect on bulk NR properties, that is, solvent resistance, hardness, resistance to oxidation, rheological behavior, and resistance to stretching out.

  2. Evolution of weak perturbations in gas-solid suspension with chemical reaction

    Energy Technology Data Exchange (ETDEWEB)

    Sharypov, O.V. [Russian Academy of Sciences, Novosibirsk (Russian Federation). Inst. of Thermophysics; Novosibirsk State Univ. (Russian Federation); Anufriev, I.S. [Novosibirsk State Univ. (Russian Federation)

    2013-07-01

    Dynamics of weak finite-amplitude perturbations in two-phase homogeneous medium (gas + solid particles) with non-equilibrium chemical reaction in gas is studied theoretically. Non-linear model of plane perturbation evolution is substantiated. The model takes into account wave-kinetic interaction and dissipation effects, including inter-phase heat and momentum transfer. Conditions for uniform state of the system are analyzed. Non-linear equation describing evolution of plane perturbation is derived under weak dispersion and dissipation effects. The obtained results demonstrate self-organization in the homogeneous system: steady-state periodic structure arises, its period, amplitude and velocity depends on the features of the medium. The dependencies of these parameters on dissipation and chemical kinetics are analyzed.

  3. Chromium 51 em K2CrO4: reactions of dopant atoms in solid state

    International Nuclear Information System (INIS)

    Valim, J.B.; Nascimento, R.L.G. do; Collins, C.H.; Collins, K.E.

    1986-01-01

    The study of the chemistry of 'dopant' 51 Cr(III) atoms in crystalline Cr(VI) compounds began as a sub-field of Hot Atom Chemistry. We shall review the attempts to use 'dopant' chromium-51 atoms as surrogate chromium recoil atoms with the special property of having a low-energy, recoil-dam-age-free history. These dopant atoms have shown behaviors very similar to those of high energy recoil 51 Gr atoms, thus offering little hope of learning about special damage site structures and reactions by behavioral differences. Recent work has shown that at least some of the 'dopant' 51 Cr(III) is present as a second, non-chromate solid phase in 'doped crystal' experiments. Monodisperse 51 Cr(OH) 3 particles mixed with pure K 2 CrO 4 are very reactive. (Author) [pt

  4. Formation of barium strontium titanate powder by solid state reaction using different calcination temperatures

    International Nuclear Information System (INIS)

    Teoh Wah Tzu; Ahmad Fauzi Mohd Noor; Zainal Arifin Ahmad

    2002-01-01

    The unique electrical properties of large permittivity in Barium Strontium Titanate have been widely used to make capacitors; it can be produced by solid state reaction. In this study, the mixture of Barium Carbonate, Strontium Carbonate and Titanium Dioxide was calcined at 500 degree C, 1000 degree C, 1100 degree C , 1150 degree C, 1200 degree C, 1250 degree C and 1300 degree C. The results of the phases change in each stage were investigated via X ay Diffraction. The results show that the formation of Barium Strontium Titanate started at 1100 degree C with the presence of other phases. The mixture is fully reacted to form Barium Strontium Titanate at 1150 degree C. Only Barium Strontium Titanate was formed as the calcination temperature was set higher. (Author)

  5. Transport phenomena in solid oxide fuel cell electrodes focusing on heat transfer related to chemical reactions

    International Nuclear Information System (INIS)

    Navasa, M; Andersson, M; Yuan, J; Sundén, B

    2012-01-01

    Solid oxide fuel cells (SOFCs) are widely studied for their advantages especially at high temperatures. However, operating at high temperatures represents a high cost due to the strict requirements the materials are expected to fulfill. Thus, the main goal in SOFC research has been to decrease the operating temperature so that the range of available materials is widened and hence, the operating cost can be reduced. In this paper, the different heat sources that contribute to the cell energy balance are presented with strong emphasis on the chemical reactions that take place in SOFCs. The knowledge of which heat sources or sinks taking place and their locations within the SOFC can provide useful information for further design and efficiency improvements.

  6. The international symposium on 'chemical engineering of gas-liquid-solid catalyst reactions'

    Energy Technology Data Exchange (ETDEWEB)

    Hammer, H

    1978-06-01

    A report on the International Symposium on ''Chemical Engineering of Gas-Liquid-Solid Catalyst Reactions'', sponsored by the University of Liege (3/2-3/78), covers papers on the hydrodynamics, modeling and simulation, operating behavior, and chemical kinetics of trickle-bed reactors; scale-up of a trickle-bed reactor for hydrotreating Kuwait vacuum distillate; experimental results obtained in trickle-bed reactors for hydroprocessing atmospheric residua, hydrogenation of methylstyrene, hydrogenation of butanone, and hydrodemetallization of petroleum residua; advantages and disadvantages of various three-phase reactor types (e.g., for the liquid-phase hydrogenation of carbon monoxide to benzene, SNG, or methanol) and hydrodynamics, mass and heat transfer, and modeling of bubble columns with suspended catalysts (slurry reactors), and their applications (e.g., in SNG and fermentation processes).

  7. Coherent diffractive imaging of solid state reactions in zinc oxide crystals

    Science.gov (United States)

    Leake, Steven J.; Harder, Ross; Robinson, Ian K.

    2011-11-01

    We investigated the doping of zinc oxide (ZnO) microcrystals with iron and nickel via in situ coherent x-ray diffractive imaging (CXDI) in vacuum. Evaporated thin metal films were deposited onto the ZnO microcrystals. A single crystal was selected and tracked through annealing cycles. A solid state reaction was observed in both iron and nickel experiments using CXDI. A combination of the shrink wrap and guided hybrid-input-output phasing methods were applied to retrieve the electron density. The resolution was 33 nm (half order) determined via the phase retrieval transfer function. The resulting images are nevertheless sensitive to sub-angstrom displacements. The exterior of the microcrystal was found to degrade dramatically. The annealing of ZnO microcrystals coated with metal thin films proved an unsuitable doping method. In addition the observed defect structure of one crystal was attributed to the presence of an array of defects and was found to change upon annealing.

  8. [Studies of chemical reactions in solid matrices]. Final report, December 1,, 1979-November 30, 1984

    International Nuclear Information System (INIS)

    Willard, J.E.

    1984-12-01

    This program, which has been supported for 35 years by the Atomic Energy Commission and its successor agencies, has produced significant advances in the understanding of the mechanisms of: (1) chemical activation by nuclear processes; (2) radiation chemistry; and (3) photochemistry. It has advanced knowledge of the reactions of electrons, hydrogen atoms and small free radicals, particularly in solids at cryogenic temperatures. It has applied radioisotopes as a tool in the solution of a number of chemical problems, has developed useful new techniques, and has contributed to the training of approximately 150 scientists at various levels. This final report includes a review of the evolution of areas of research emphasized, tabulations of the publications (chronologically and by research area) and Ph.D. theses resulting from the program, and tabulations of the research personnel (by academic category, by dates in the program and by subsequent employment)

  9. 21 CFR 330.3 - Imprinting of solid oral dosage form drug products.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 5 2010-04-01 2010-04-01 false Imprinting of solid oral dosage form drug products... AS SAFE AND EFFECTIVE AND NOT MISBRANDED General Provisions § 330.3 Imprinting of solid oral dosage form drug products. A requirement to imprint an identification code on solid oral dosage form drug...

  10. Package selection for moisture protection for solid, oral drug products.

    Science.gov (United States)

    Waterman, Kenneth C; MacDonald, Bruce C

    2010-11-01

    This review describes how best to select the appropriate packaging options for solid, oral drug products based on both chemical and physical stability, with respect to moisture protection. This process combines an accounting for the initial moisture content of dosage form components, moisture transfer into (out of) packaging based on a moisture vapor transfer rate (MVTR), and equilibration between drug products and desiccants based on their moisture sorption isotherms to provide an estimate of the instantaneous relative humidity (RH) within the packaging. This time-based RH is calculationally combined with a moisture-sensitive Arrhenius equation (determined using the accelerated stability assessment program, ASAP) to predict the drug product's chemical stability over time as a function of storage conditions and packaging options. While physical stability of dosage forms with respect to moisture has been less well documented, a process is recommended based on the threshold RH at which changes (e.g., dosage form dissolution, tablet hardness, drug form) become problematic. The overall process described allows packaging to be determined for a drug product scientifically, with the effect of any changes to storage conditions or packaging to be explicitly accounted for. © 2010 Wiley-Liss, Inc. and the American Pharmacists Association

  11. An optics-based variable-temperature assay system for characterizing thermodynamics of biomolecular reactions on solid support

    Energy Technology Data Exchange (ETDEWEB)

    Fei, Yiyan; Landry, James P.; Zhu, X. D., E-mail: xdzhu@physics.ucdavis.edu [Department of Physics, University of California, One Shields Avenue, Davis, California 95616 (United States); Li, Yanhong; Yu, Hai; Lau, Kam; Huang, Shengshu; Chokhawala, Harshal A.; Chen, Xi [Department of Chemistry, University of California, One Shields Avenue, Davis, California 95616 (United States)

    2013-11-15

    A biological state is equilibrium of multiple concurrent biomolecular reactions. The relative importance of these reactions depends on physiological temperature typically between 10 °C and 50 °C. Experimentally the temperature dependence of binding reaction constants reveals thermodynamics and thus details of these biomolecular processes. We developed a variable-temperature opto-fluidic system for real-time measurement of multiple (400–10 000) biomolecular binding reactions on solid supports from 10 °C to 60 °C within ±0.1 °C. We illustrate the performance of this system with investigation of binding reactions of plant lectins (carbohydrate-binding proteins) with 24 synthetic glycans (i.e., carbohydrates). We found that the lectin-glycan reactions in general can be enthalpy-driven, entropy-driven, or both, and water molecules play critical roles in the thermodynamics of these reactions.

  12. Reaction of hydrogen peroxide with uranium zirconium oxide solid solution - Zirconium hinders oxidative uranium dissolution

    Science.gov (United States)

    Kumagai, Yuta; Takano, Masahide; Watanabe, Masayuki

    2017-12-01

    We studied oxidative dissolution of uranium and zirconium oxide [(U,Zr)O2] in aqueous H2O2 solution to estimate (U,Zr)O2 stability to interfacial reactions with H2O2. Studies on the interfacial reactions are essential for anticipating how a (U,Zr)O2-based molten fuel may chemically degrade after a severe accident. The fuel's high radioactivity induces water radiolysis and continuous H2O2 generation. Subsequent reaction of the fuel with H2O2 may oxidize the fuel surface and facilitate U dissolution. We conducted our experiments with (U,Zr)O2 powder (comprising Zr:U mole ratios of 25:75, 40:60, and 50:50) and quantitated the H2O2 reaction via dissolved U and H2O2 concentrations. Although (U,Zr)O2 reacted more quickly than UO2, the dissolution yield relative to H2O2 consumption was far less for (U,Zr)O2 compared to that of UO2. The reaction kinetics indicates that most of the H2O2 catalytically decomposed to O2 at the surface of (U,Zr)O2. We confirmed the H2O2 catalytic decomposition via O2 production (quantitative stoichiometric agreement). In addition, post-reaction Raman scattering spectra of the undissolved (U,Zr)O2 showed no additional peaks (indicating a lack of secondary phase formation). The (U,Zr)O2 matrix is much more stable than UO2 against H2O2-induced oxidative dissolution. Our findings will improve understanding on the molten fuels and provide an insight into decommissioning activities after a severe accident.

  13. Solid targets for 99mTc production on medical cyclotrons

    International Nuclear Information System (INIS)

    Hanemaayer, V.; Buckley, K.R.; Klug, J.; Ruth, T.J.; Schaffer, P.; Zeisler, S.K.; Benard, F.; Kovacs, M.; Leon, C.

    2014-01-01

    Recent disruptions in the molybdenum-technetium generator supply chain prompted a review of non-reactor based production methods for both 99 Mo and 99m Tc. Small medical cyclotrons (E p ∼ 16-24 MeV) are capable of producing Curie quantities of 99m Tc from isotopically enriched 100 Mo using the 100 Mo(p,2n) 99m Tc reaction. Unlike most other metallic target materials for routine production of medical radioisotopes, molybdenum cannot be deposited by reductive electroplating from aqueous salt solutions. To overcome this issue, we developed a new process for solid molybdenum targets based on the electrophoretic deposition of fine 100 Mo powder onto a tantalum plate, followed by high temperature sintering. The targets obtained were mechanically robust and thermally stable when irradiated with protons at high power density. (author)

  14. Method of conversion of caustic liquid radioactive wastes containing sodium nitrates into solid insoluble products

    International Nuclear Information System (INIS)

    Barney, G.S.; Brownell, L.E.

    1975-01-01

    A proposal is made to convert caustic, liquid, radioactive wastes containing sodium nitrate into a solid product by reaction with powdered aluminium silicate at temperatures between 30 0 and 100 0 C, which is practically insoluble (10 -7 to 10 -10 g/cm 2 -day) and is thermally stable. A cancrinite is formed which binds the radioactive salts in the cage-like structure of its crystal lattice. The method is also suitable for liquid wastes from the Purex method as well as for wastes containing fission products of Cs 137 and Sr 90 in concentrations of 0.37 M to 0.01 M. Numerous detailed examples explain the invention. (UW/LH) [de

  15. Solid-Solid Vacuum Regolith Heat-Exchanger for Oxygen Production, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase-1 project will demonstrate the feasibility of using a novel coaxial counterflow solid-solid heat exchanger to recover heat energy from spent regolith...

  16. Multiphasic Reaction Modeling for Polypropylene Production in a Pilot-Scale Catalytic Reactor

    Directory of Open Access Journals (Sweden)

    Mohammad Jakir Hossain Khan

    2016-06-01

    Full Text Available In this study, a novel multiphasic model for the calculation of the polypropylene production in a complicated hydrodynamic and the physiochemical environments has been formulated, confirmed and validated. This is a first research attempt that describes the development of the dual-phasic phenomena, the impact of the optimal process conditions on the production rate of polypropylene and the fluidized bed dynamic details which could be concurrently obtained after solving the model coupled with the CFD (computational fluid dynamics model, the basic mathematical model and the moment equations. Furthermore, we have established the quantitative relationship between the operational condition and the dynamic gas–solid behavior in actual reaction environments. Our results state that the proposed model could be applied for generalizing the production rate of the polymer from a chemical procedure to pilot-scale chemical reaction engineering. However, it was assumed that the solids present in the bubble phase and the reactant gas present in the emulsion phase improved the multiphasic model, thus taking into account that the polymerization took place mutually in the emulsion besides the bubble phase. It was observed that with respect to the experimental extent of the superficial gas velocity and the Ziegler-Natta feed rate, the ratio of the polymer produced as compared to the overall rate of production was approximately in the range of 9%–11%. This is a significant amount and it should not be ignored. We also carried out the simulation studies for comparing the data of the CFD-dependent dual-phasic model, the emulsion phase model, the dynamic bubble model and the experimental results. It was noted that the improved dual-phasic model and the CFD model were able to predict more constricted and safer windows at similar conditions as compared to the experimental results. Our work is unique, as the integrated developed model is able to offer clearer ideas

  17. CuInSe2 nano-crystallite reaction kinetics using solid state reaction from Cu2Se and In2Se3 powders

    International Nuclear Information System (INIS)

    Hsiang, Hsing-I; Lu, Li-Hsin; Chang, Yu-Lun; Ray, Dahtong; Yen, Fu-Su

    2011-01-01

    Highlights: → CuInSe 2 phase increased gradually accompanied with a decrease in γ-In 2 Se 3 and no intermediate phase during calcination. → CuInSe 2 formation from Cu 2 Se and In 2 Se 3 powders follows a one-dimensional diffusion-controlled reaction with apparent activation energy of about 122.5 kJ/mol. → The solid reaction kinetics may be dominated by the diffusion of In 3+ ions. - Abstract: The reaction mechanism and CuInSe 2 formation kinetics using a solid state reaction from Cu 2 Se and In 2 Se 3 powders synthesized using a heating up process were investigated using X-ray diffractomy (XRD) and transmission electron microscopy (TEM). It was observed that the CuInSe 2 phase increased gradually, accompanied with a decrease in γ-In 2 Se 3 with no intermediate phase as the calcination temperature and soaking time were increased. The reaction kinetics was analyzed using the Avrami and polynomial kinetic model, suggesting that CuInSe 2 formation from Cu 2 Se and In 2 Se 3 powders follows a diffusion-controlled reaction with an apparent activation energy of about 122.5-182.3 kJ/mol. Cu 2 Se and In 2 Se 3 phases react and directly transform into CIS without the occurrence of any intermediate phase and the size of the newly formed CuInSe 2 crystallites was close to that of the Cu 2 Se reactant particle based on the TEM results, which indicated that the solid reaction kinetics may be dominated by the diffusion of In 3+ ions.

  18. Production of Energetic Light Fragments in Spallation Reactions

    Directory of Open Access Journals (Sweden)

    Mashnik Stepan G.

    2014-03-01

    Full Text Available Different reaction mechanisms contribute to the production of light fragments (LF from nuclear reactions. Available models cannot accurately predict emission of LF from arbitrary reactions. However, the emission of LF is important formany applications, such as cosmic-ray-induced single event upsets, radiation protection, and cancer therapy with proton and heavy-ion beams, to name just a few. The cascade-exciton model (CEM and the Los Alamos version of the quark-gluon string model (LAQGSM, as implemented in the CEM03.03 and LAQGSM03.03 event generators used in the Los Alamos Monte Carlo transport code MCNP6, describe quite well the spectra of fragments with sizes up to 4He across a broad range of target masses and incident energies. However, they do not predict high-energy tails for LF heavier than 4He. The standard versions of CEM and LAQGSM do not account for preequilibrium emission of LF larger than 4He. The aim of our work is to extend the preequilibrium model to include such processes. We do this by including the emission of fragments heavier than 4He at the preequilibrium stage, and using an improved version of the Fermi Break-up model, providing improved agreement with various experimental data.

  19. Solid Base Catalysis

    CERN Document Server

    Ono, Yoshio

    2011-01-01

    The importance of solid base catalysts has come to be recognized for their environmentally benign qualities, and much significant progress has been made over the past two decades in catalytic materials and solid base-catalyzed reactions. The book is focused on the solid base. Because of the advantages over liquid bases, the use of solid base catalysts in organic synthesis is expanding. Solid bases are easier to dispose than liquid bases, separation and recovery of products, catalysts and solvents are less difficult, and they are non-corrosive. Furthermore, base-catalyzed reactions can be performed without using solvents and even in the gas phase, opening up more possibilities for discovering novel reaction systems. Using numerous examples, the present volume describes the remarkable role solid base catalysis can play, given the ever increasing worldwide importance of "green" chemistry. The reader will obtain an overall view of solid base catalysis and gain insight into the versatility of the reactions to whic...

  20. NUCLEAR MAGNETIC RESONANCE THE GELLED PRODUCT OF CANNIZZARO REACTION

    Directory of Open Access Journals (Sweden)

    Lilia Fernández-Sánchez

    2015-03-01

    Full Text Available The paper presents the nuclear magnetic resonance (NMR of proton 1H, carbon 13C and two dimensional spectrums, product of a green organic synthesis of redox on the Cannizzaro reaction. The product was reported as a tribochemical gel (heterogeneous mixture and confirmed by Infrared Spectroscopy IR, X-ray and scanning electron microscope (SEM. The results in this paper confirm its structure through various techniques of NMR and evaluate the content of sodium benzoate and benzyl alcohol in the spectroscopy sample, examining the values of the integrals on 1H NMR signals. The result of analysis indicates that benzyl alcohol (dispersed phase is in 33.44% mol in comparison with sodium benzoate content (continuous phase. These results confirm that the gel structure over time loses the dispersed phase of the benzyl alcohol producing a xerogel.

  1. Studies of evaporation residue products from krypton and argon reactions

    International Nuclear Information System (INIS)

    Plasil, F.; Ferguson, R.L.; Britt, H.C.; Erkkila, B.H.; Blann, M.; Gutbrod, H.H.; California Univ., Berkeley

    1978-01-01

    Mass distributions of evaporation residue (ER) products from 86 Kr-bombardments of 70 Ge and 74 Ge have been obtained by a time-of-flight method at energies ranging from the interaction barrier to 706 MeV. ER excitation functions have also been obtained for a variety of target and projectile combinations. Results are compared with statistical model calculations and with results obtained from γ-measurements. It is deduced that at the lowest impact parameters, the reaction products belong to the ER group, in contrast with the angular momentum hypothesis of Lefort. Cross sections were found to be consistent with an angular momentum limit arising from the onset of fission. (orig.) [de

  2. Kinetics of the direct sulfation of limestone at the initial stage of crystal growth of the solid product

    DEFF Research Database (Denmark)

    Hu, Guilin; Dam-Johansen, Kim; Wedel, Stig

    2011-01-01

    The direct sulfation of limestone was studied in a quartz bench scale fixed‐bed reactor with the technique of data deconvolution. The obtained results show that the direct sulfation of limestone has a two‐period kinetic behavior: a short initial sulfation period with high but fast decreasing...... such as SO2, O2, and CO2 and the temperature. The sulfation process in the initial stage of the period with product crystal growth can be described by the combination of the sulfation reaction at the gas–solid interface, diffusion of the product ions toward the product crystal grains, diffusion of carbonate...

  3. Enzymatic lignocellulose hydrolysis: Improved cellulase productivity by insoluble solids recycling

    DEFF Research Database (Denmark)

    Weiss, Noah Daniel; Börjesson, Johan; Pedersen, Lars Saaby

    2013-01-01

    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 enzym...

  4. Lipase production by Penicillium restrictum using solid waste of industrial babassu oil production as substrate.

    Science.gov (United States)

    Palma, M B; Pinto, A L; Gombert, A K; Seitz, K H; Kivatinitz, S C; Castilho, L R; Freire, D M

    2000-01-01

    Lipase, protease, and amylase production by Penicillium restrictum in solid-state fermentation was investigated. The basal medium was an industrial waste of babassu oil (Orbignya oleifera) production. It was enriched with peptone, olive oil, and Tween-80. The supplementation positively influenced both enzyme production and fungal growth. Media enriched with Tween-80 provided the highest protease activity (8.6 U/g), whereas those enriched with peptone and olive oil led to the highest lipase (27.8 U/g) and amylase (31.8 U/g) activities, respectively.

  5. Durability of solid oxide electrolysis cells for hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Hauch, A.; Hoejgaard Jensen, S.; Dalgaard Ebbesen, S.

    2007-05-15

    In the perspective of the increasing interest in renewable energy and hydrogen economy, the reversible solid oxide cells (SOCs) is a promising technology as it has the potential of providing efficient and cost effective hydrogen production by high temperature electrolysis of steam (HTES). Furthermore development of such electrolysis cells can gain from the results obtained within the R and D of SOFCs. For solid oxide electrolysis cells (SOEC) to become interesting from a technological point of view, cells that are reproducible, high performing and long-term stable need to be developed. In this paper we address some of the perspectives of the SOEC technology i.e. issues such as a potential H2 production price as low as 0.71 US dollar/kg H{sub 2} using SOECs for HTES; is there a possible market for the electrolysers? and what R and D steps are needed for the realisation of the SOEC technology? In the experimental part we present electrolysis test results on SOCs that have been optimized for fuel cell operation but applied for HTES. The SOCs are produced on a pre-pilot scale at Risoe National Laboratory. These cells have been shown to have excellent initial electrolysis performance, but the durability of such electrolysis cells are not optimal and examples of results from SOEC tests over several hundreds of hours are given here. The long-term tests have been run at current densities of -0.5 A/cm{sup 2} and -1 A/cm{sup 2}, temperatures of 850 deg. C and 950 deg. C and p(H{sub 2}O)/p(H{sub 2}) of 0.5/0.5 and 0.9/0.1. Long-term degradation rates are shown to be up to 5 times higher for SOECs compared to similar SOFC testing. Furthermore, hydrogen and synthetic fuel production prices are calculated using the experimental results from long-term electrolysis test as input and a short outlook for the future work on SOECs will be given as well. (au)

  6. Composition, production rate and characterization of Greek dental solid waste.

    Science.gov (United States)

    Mandalidis, Alexandros; Topalidis, Antonios; Voudrias, Evangelos A; Iosifidis, Nikolaos

    2018-05-01

    The overall objective of this work is to determine the composition, characterization and production rate of Greek dental solid waste (DSW). This information is important to design and cost management systems for DSW, for safety and health considerations and for assessing environmental impact. A total of 141 kg of DSW produced by a total of 2542 patients in 20 dental practices from Xanthi, Greece was collected, manually separated and weighed over a period of four working weeks. The waste was separated in 19 sub fractions, which were classified in 2 major categories, according to Greek regulations: Domestic-type waste comprising 8% and hazardous waste comprising 92% by weight of total DSW. The latter was further classified in infectious waste, toxic waste and mixed type waste (infectious and toxic together), accounting for 88.5%, 3.5% and 0.03% of total DSW by weight, respectively. The overall unit production rates (mean ± standard error of the mean) were 381 ± 15 g/practice/d and 53.3 ± 1.4 g/patient/d for total DSW, 337 ± 14 g/practice/d and 46.6 ± 1.2 g/patient/d for total infectious DSW, 13.4 ± 0.7 g/practice/d and 2.1 ± 0.1 g/patient/d for total toxic DSW and 30.4 ± 2.5 g/practice/d and 4.6 ± 0.4 g/patient/d for domestic-type waste. Daily DSW production was correlated with daily number of patients and regression correlations were produced. DSW was subject to laboratory characterization in terms of bulk density, calorific value, moisture, ash and volatile solids content. Measured calorific values were compared to predictions from empirical models. Copyright © 2018 Elsevier Ltd. All rights reserved.

  7. Thermal conversion of municipal solid waste via hydrothermal carbonization: comparison of carbonization products to products from current waste management techniques.

    Science.gov (United States)

    Lu, Xiaowei; Jordan, Beth; Berge, Nicole D

    2012-07-01

    Hydrothermal carbonization (HTC) is a novel thermal conversion process that may be a viable means for managing solid waste streams while minimizing greenhouse gas production and producing residual material with intrinsic value. HTC is a wet, relatively low temperature (180-350 °C) thermal conversion process that has been shown to convert biomass to a carbonaceous residue referred to as hydrochar. Results from batch experiments indicate HTC of representative waste materials is feasible, and results in the majority of carbon (45-75% of the initially present carbon) remaining within the hydrochar. Gas production during the batch experiments suggests that longer reaction periods may be desirable to maximize the production of energy-favorable products. If using the hydrochar for applications in which the carbon will remain stored, results suggest that the gaseous products from HTC result in fewer g CO(2)-equivalent emissions than the gases associated with landfilling, composting, and incineration. When considering the use of hydrochar as a solid fuel, more energy can be derived from the hydrochar than from the gases resulting from waste degradation during landfilling and anaerobic digestion, and from incineration of food waste. Carbon emissions resulting from the use of the hydrochar as a fuel source are smaller than those associated with incineration, suggesting HTC may serve as an environmentally beneficial alternative to incineration. The type and extent of environmental benefits derived from HTC will be dependent on hydrochar use/the purpose for HTC (e.g., energy generation or carbon storage). Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Electrolytic Production of Ti5Si3/TiC Composites by Solid Oxide Membrane Technology

    Science.gov (United States)

    Zheng, Kai; Zou, Xingli; Xie, Xueliang; Lu, Changyuan; Chen, Chaoyi; Xu, Qian; Lu, Xionggang

    2018-02-01

    This paper investigated the electrolytic production of Ti5Si3/TiC composites from TiO2/SiO2/C in molten CaCl2. The solid-oxide oxygen-ion-conducting membrane tube filled with carbon-saturated liquid tin was served as the anode, and the pressed spherical TiO2/SiO2/C pellet was used as the cathode. The electrochemical reduction process was carried out at 1273 K and 3.8 V. The characteristics of the obtained cathode products and the reaction mechanism of the electroreduction process were studied by a series of time-dependent electroreduction experiments. It was found that the electroreduction process generally proceeds through the following steps: TiO2/SiO2/C → Ti2O3, CaTiO3, Ca2SiO4, SiC → Ti5Si3, TiC. The morphology observation and the elemental distribution analysis indicate that the reaction routes for Ti5Si3 and TiC products are independent during the electroreduction process.

  9. Flavin-catalyzed redox tailoring reactions in natural product biosynthesis.

    Science.gov (United States)

    Teufel, Robin

    2017-10-15

    Natural products are distinct and often highly complex organic molecules that constitute not only an important drug source, but have also pushed the field of organic chemistry by providing intricate targets for total synthesis. How the astonishing structural diversity of natural products is enzymatically generated in biosynthetic pathways remains a challenging research area, which requires detailed and sophisticated approaches to elucidate the underlying catalytic mechanisms. Commonly, the diversification of precursor molecules into distinct natural products relies on the action of pathway-specific tailoring enzymes that catalyze, e.g., acylations, glycosylations, or redox reactions. This review highlights a selection of tailoring enzymes that employ riboflavin (vitamin B2)-derived cofactors (FAD and FMN) to facilitate unusual redox catalysis and steer the formation of complex natural product pharmacophores. Remarkably, several such recently reported flavin-dependent tailoring enzymes expand the classical paradigms of flavin biochemistry leading, e.g., to the discovery of the flavin-N5-oxide - a novel flavin redox state and oxygenating species. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Renewable Energy Production from DoD Installation Solid Wastes by Anaerobic Digestion

    Science.gov (United States)

    2016-06-01

    ENGINEERING GUIDANCE REPORT Renewable Energy Production from DoD Installation Solid Wastes by Anaerobic Digestion ESTCP Project ER-200933 JUNE...Defense. Page Intentionally Left Blank Renewable Energy Production From DoD Installation Solid Wastes by Anaerobic Digestion ii June 2016 REPORT...3. DATES COVERED (2009 – 2016) 4. TITLE AND SUBTITLE Renewable Energy Production from DoD Installation Solid Wastes by Anaerobic Digestion 5a

  11. An Overview of Natural Gas Conversion Technologies for Co-Production of Hydrogen and Value-Added Solid Carbon Products

    Energy Technology Data Exchange (ETDEWEB)

    Dagle, Robert A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Dagle, Vanessa [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bearden, Mark D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Holladay, Jamelyn D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Krause, Theodore R. [Argonne National Lab. (ANL), Argonne, IL (United States); Ahmed, Shabbir [Argonne National Lab. (ANL), Argonne, IL (United States)

    2017-11-16

    This report was prepared in response to the U.S. Department of Energy Fuel Cell Technologies Office Congressional Appropriation language to support research on carbon-free production of hydrogen using new chemical processes that utilize natural gas to produce solid carbon and hydrogen. The U.S. produces 9-10 million tons of hydrogen annually with more than 95% of the hydrogen produced by steam-methane reforming (SMR) of natural gas. SMR is attractive because of its high hydrogen yield; but it also converts the carbon to carbon dioxide. Non-oxidative thermal decomposition of methane to carbon and hydrogen is an alternative to SMR and produces CO2-free hydrogen. The produced carbon can be sold as a co-product, thus providing economic credit that reduces the delivered net cost of hydrogen. The combination of producing hydrogen with potentially valuable carbon byproducts has market value in that this allows greater flexibility to match the market prices of hydrogen and carbon. That is, the higher value product can subsidize the other in pricing decisions. In this report we highlight the relevant technologies reported in the literature—primarily thermochemical and plasma conversion processes—and recent research progress and commercial activities. Longstanding technical challenges include the high energetic requirements (e.g., high temperatures and/or electricity requirements) necessary for methane activation and, for some catalytic processes, the separation of solid carbon product from the spent catalyst. We assess current and new carbon product markets that could be served given technological advances, and we discuss technical barriers and potential areas of research to address these needs. We provide preliminary economic analysis for these processes and compare to other emerging (e.g., electrolysis) and conventional (e.g., SMR) processes for hydrogen production. The overarching conclusion of this study is that the cost of hydrogen can be potentially

  12. Preparation of Ultra-Fine Nickel Manganite Powders and Ceramics by a Solid-State Coordination Reaction

    NARCIS (Netherlands)

    Fang, Dao-lai; Wang, Zhongbing; Wang, Zhichun; Yang, Pinghua; Liu, W.; Liu, Wei; Winnubst, Aloysius J.A.; Chen, Chusheng

    2006-01-01

    A solid-state coordination reaction was adopted to prepare negative temperature coefficient ceramics. A mixed oxalate NiMn2(C2O4)3·6H2O, a coordination compound, was synthesized by milling a mixture of nickel acetate, manganese acetate, and oxalic acid for 5 h at room temperature. An ultrafine

  13. A model for a countercurrent gas—solid—solid trickle flow reactor for equilibrium reactions. The methanol synthesis

    NARCIS (Netherlands)

    Westerterp, K.R.; Kuczynski, M.

    1987-01-01

    The theoretical background for a novel, countercurrent gas—solid—solid trickle flow reactor for equilibrium gas reactions is presented. A one-dimensional, steady-state reactor model is developed. The influence of the various process parameters on the reactor performance is discussed. The physical

  14. Electrode Reaction Pathway in Oxide Anode for Solid Oxide Fuel Cells

    Science.gov (United States)

    Li, Wenyuan

    Oxide anodes for solid oxide fuel cells (SOFC) with the advantage of fuel flexibility, resistance to coarsening, small chemical expansion and etc. have been attracting increasing interest. Good performance has been reported with a few of perovskite structure anodes, such as (LaSr)(CrMn)O3. However, more improvements need to be made before meeting the application requirement. Understanding the oxidation mechanism is crucial for a directed optimization, but it is still on the early stage of investigation. In this study, reaction mechanism of oxide anodes is investigated on doped YCrO 3 with H2 fuel, in terms of the origin of electrochemical activity, rate-determining steps (RDS), extension of reactive zone, and the impact from overpotential under service condition to those properties. H2 oxidation on the YCs anodes is found to be limited by charge transfer and H surface diffusion. A model is presented to describe the elementary steps in H2 oxidation. From the reaction order results, it is suggested that any models without taking H into the charge transfer step are invalid. The nature of B site element determines the H2 oxidation kinetics primarily. Ni displays better adsorption ability than Co. However, H adsorption ability of such oxide anode is inferior to that of Ni metal anode. In addition, the charge transfer step is directly associated with the activity of electrons in the anode; therefore it can be significantly promoted by enhancement of the electron activity. It is found that A site Ca doping improves the polarization resistance about 10 times, by increasing the activity of electrons to promote the charge transfer process. For the active area in the oxide anode, besides the traditional three-phase boundary (3PB), the internal anode surface as two-phase boundary (2PB) is proven to be capable of catalytically oxidizing the H2 fuel also when the bulk lattice is activated depending on the B site elements. The contribution from each part is estimated by switching

  15. Evaluation of Neutron Induced Reactions for 32 Fission Products

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyeong Il

    2007-02-15

    Neutron cross sections for 32 fission products were evaluated in the neutron-incident energy range from 10{sup -5} eV to 20 MeV. The list of fission products consists of the priority materials for several applications, extended to cover complete isotopic chains for three elements. The full list includes 8 individual isotopes, {sup 95}Mo, {sup 101}Ru, {sup 103}Rh, {sup 105}Pd, {sup 109}Ag, {sup 131}Xe, {sup 133}Cs, {sup 141}Pr, and 24 isotopes in complete isotopic chains for Nd (8), Sm (9) and Dy (7). Our evaluation methodology covers both the low energy region and the fast neutron region.In the low energy region, our evaluations are based on the latest data published in the Atlas of Neutron Resonances. This resource was used to infer both the thermal values and the resolved resonance parameters that were validated against the capture resonance integrals. In the unresolved resonance region we performed the additional evaluation by using the averages of the resolved resonances and adjusting them to the experimental data.In the fast neutron region our evaluations are based on the nuclear reaction model code EMPIRE-2.19 validated against the experimental data. EMPIRE is the modular system of codes consisting of many nuclear reaction models, including the spherical and deformed Optical Model, Hauser-Feshbach theory with the width fluctuation correction and complete gamma-ray emission cascade, DWBA, Multi-step Direct and Multi-step Compound models, and several versions of the phenomenological preequilibrium models. The code is equipped with a power full GUI, allowing an easy access to support libraries such as RIPL and CSISRS, the graphical package, as well the utility codes for formatting and checking. In general, in our calculations we used the Reference Input Parameter Library, RIPL, for the initial set model parameters. These parameters were properly adjusted to reproduce the available experimental data taken from the CSISRS library. Our evaluations cover cross

  16. Evaluation of Neutron Induced Reactions for 32 Fission Products

    International Nuclear Information System (INIS)

    Kim, Hyeong Il

    2007-02-01

    Neutron cross sections for 32 fission products were evaluated in the neutron-incident energy range from 10 -5 eV to 20 MeV. The list of fission products consists of the priority materials for several applications, extended to cover complete isotopic chains for three elements. The full list includes 8 individual isotopes, 95 Mo, 101 Ru, 103 Rh, 105 Pd, 109 Ag, 131 Xe, 133 Cs, 141 Pr, and 24 isotopes in complete isotopic chains for Nd (8), Sm (9) and Dy (7). Our evaluation methodology covers both the low energy region and the fast neutron region.In the low energy region, our evaluations are based on the latest data published in the Atlas of Neutron Resonances. This resource was used to infer both the thermal values and the resolved resonance parameters that were validated against the capture resonance integrals. In the unresolved resonance region we performed the additional evaluation by using the averages of the resolved resonances and adjusting them to the experimental data.In the fast neutron region our evaluations are based on the nuclear reaction model code EMPIRE-2.19 validated against the experimental data. EMPIRE is the modular system of codes consisting of many nuclear reaction models, including the spherical and deformed Optical Model, Hauser-Feshbach theory with the width fluctuation correction and complete gamma-ray emission cascade, DWBA, Multi-step Direct and Multi-step Compound models, and several versions of the phenomenological preequilibrium models. The code is equipped with a power full GUI, allowing an easy access to support libraries such as RIPL and CSISRS, the graphical package, as well the utility codes for formatting and checking. In general, in our calculations we used the Reference Input Parameter Library, RIPL, for the initial set model parameters. These parameters were properly adjusted to reproduce the available experimental data taken from the CSISRS library. Our evaluations cover cross sections for almost all reaction channels

  17. Flavor production in bar pp reactions at low energies

    International Nuclear Information System (INIS)

    Eisenstein, R.A.

    1994-01-01

    Associated production processes have been known since the 1050's. The solution to the puzzle they presented was to introduce the 'strangeness' quantum number, along with the notion of its conservation in strong interactions. For example, the reaction π + n → K + Λ is described both as the t-channel exchange of a K 0 meson, ans as an s-channel process involving the annihilation of a d bar d quark pair and the subsequent production of an s bar s pair. This basic 'flavor-production' process and ones like it are the focus of widespread interest and the subject of this talk. The physics to be addressed is the nature of the quark annihilation and the creation process, which is expected to proceed according to the rules of quantum chromodynamics (QCD). According to these ideas, it will be dominated by perturbative QCD (essentially single-gluon exchange) at high momentum; at low momentum the process is expected to involve a very complicated multiple gluon exchange since it is in the nonperturbative regime

  18. Chlorine in solid fuels fired in pulverized fuel boilers sources, forms, reactions, and consequences: a literature review

    Energy Technology Data Exchange (ETDEWEB)

    David A. Tillman; Dao Duong; Bruce Miller [Foster Wheeler North America Corp. (United States)

    2009-07-15

    Chlorine is a significant source of corrosion and deposition, both from coal and from biomass, and in PF boilers. This investigation was designed to highlight the potential for corrosion risks associated with once-through units and advanced cycles. The research took the form of a detailed literature investigation to evaluate chlorine in solid fuels: coals of various ranks and origins, biomass fuels of a variety of types, petroleum cokes, and blends of the above. The investigation focused upon an extensive literature review of documents dating back to 1991. The focus is strictly corrosion and deposition. To address the deposition and corrosion issues, this review evaluates the following considerations: concentrations of chlorine in available solid fuels including various coals and biomass fuels, forms of chlorine in those fuels, and reactions - including reactivities - of chlorine in such fuels. The assessment includes consideration of alkali metals and alkali earth elements as they react with, and to, the chlorine and other elements (e.g., sulfur) in the fuel and in the gaseous products of combustion. The assessment also includes other factors of combustion: for example, combustion conditions including excess O{sub 2} and combustion temperatures. It also considers analyses conducted at all levels: theoretical calculations, bench scale laboratory data and experiments, pilot plant experiments, and full scale plant experience. Case studies and plant surveys form a significant consideration in this review. The result of this investigation focuses upon the concentrations of chlorine acceptable in coals burned exclusively, in coals burned with biomass, and in biomass cofired with coal. Values are posited based upon type of fuel and combustion technology. Values are also posited based upon both first principles and field experience. 86 refs., 8 figs., 7 tabs.

  19. Maillard reaction products as antimicrobial components for packaging films.

    Science.gov (United States)

    Hauser, Carolin; Müller, Ulla; Sauer, Tanja; Augner, Kerstin; Pischetsrieder, Monika

    2014-02-15

    Active packaging foils with incorporated antimicrobial agents release the active ingredient during food storage. Maillard reaction products (MRPs) show antimicrobial activity that is at least partially mediated by H2O2. De novo generation of H2O2 by an MRP fraction, extracted from a ribose/lysine Maillard reaction mixture by 85% ethanol, was monitored at three concentrations (1.6, 16.1, and 32.3g/L) and three temperatures (4, 25, and 37 °C) between 0 and 96 h, reaching a maximum of 335 μM H2O2 (32.3g/L, 37 °C, 96 h). The active MRP fraction (16.1g/L) completely inhibited the growth of Escherichia coli for 24h and was therefore incorporated in a polyvinyl acetate-based lacquer and dispersed onto a low-density polyethylene film. The coated film generated about 100 μM H2O2 and resulted in a log-reduction of >5 log-cycles against E. coli. Thus, MRPs can be considered as active ingredients for antimicrobial packaging materials. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Production cross sections of proton-induced reactions on yttrium

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Sung-Chul; Song, Tae-Yung; Lee, Young-Ouk [Nuclear Data Center, Korea Atomic Energy Research Institute, Daejeon 34057 (Korea, Republic of); Kim, Guinyun, E-mail: gnkim@knu.ac.kr [Department of Physics, Kyungpook National University, Daegu 41566 (Korea, Republic of)

    2017-05-01

    The production cross sections of residual radionuclides such as {sup 86,88,89g}Zr, {sup 86g,87m,87g,88}Y, {sup 83g,85g}Sr, and {sup 83,84g}Rb in the {sup 89}Y(p,x) reaction were measured using a stacked-foil activation and offline γ-ray spectrometric technique with proton energies of 57 MeV and 69 MeV at the 100 MeV proton linac in the Korea Multi-purpose Accelerator Complex (KOMAC), Gyeongju, Korea. The induced activities of the activated samples were measured using a high purity germanium (HPGe) detector, and the proton flux was determined using the {sup nat}Cu(p,x){sup 62}Zn reaction. The measured data was compared with other experimental data and the data from the TENLD-2015 library based on the TALYS code. The present results are generally lower than those in literature, but are found to be in agreement with the shape of the excitation functions. The integral yields for the thick target using the measured cross sections are given.

  1. Microstructure, ferromagnetic and photoluminescence properties of ITO and Cr doped ITO nanoparticles using solid state reaction

    Energy Technology Data Exchange (ETDEWEB)

    Babu, S. Harinath [Thin Films Laboratory, Centre for Crystal Growth, VIT University, Vellore-632014, Tamilnadu, India. (India); Kaleemulla, S., E-mail: skaleemulla@gmail.com [Thin Films Laboratory, Centre for Crystal Growth, VIT University, Vellore-632014, Tamilnadu, India. (India); Rao, N. Madhusudhana [Thin Films Laboratory, Centre for Crystal Growth, VIT University, Vellore-632014, Tamilnadu, India. (India); Rao, G. Venugopal [Materials Physics Division, Indira Gandhi Centre for Atomic Research, Kalpakkam-603102, Tamilnadu (India); Krishnamoorthi, C. [Thin Films Laboratory, Centre for Crystal Growth, VIT University, Vellore-632014, Tamilnadu, India. (India)

    2016-11-01

    Indium-tin-oxide (ITO) (In{sub 0.95}Sn{sub 0.05}){sub 2}O{sub 3} and Cr doped indium-tin-oxide (In{sub 0.90}Sn{sub 0.05}Cr{sub 0.05}){sub 2}O{sub 3} nanoparticles were prepared using simple low cost solid state reaction method and characterized by different techniques to study their structural, optical and magnetic properties. Microstructures, surface morphology, crystallite size of the nanoparticles were studied using X-ray diffractometer (XRD), field emission scanning electron microscope (FE-SEM). From these methods it was found that the particles were about 45 nm. Chemical composition and valence states of the nanoparticles were studied using energy dispersive analysis of X-rays (EDAX) and X-ray photoelectron spectroscopy (XPS). From these techniques it was observed that the elements of indium, tin, chromium and oxygen were present in the system in appropriate ratios and they were in +3, +4, +3 and −2 oxidation states. Raman studies confirmed that the nanoparticle were free from unintentional impurities. Two broad emission peaks were observed at 330 nm and 460 nm when excited wavelength of 300 nm. Magnetic studies were carried out at 300 K and 100 K using vibrating sample magnetometer (VSM) and found that the ITO nanoparticles were ferromagnetic at 100 K and 300 K. Where-as the room temperature ferromagnetism completely disappeared in Cr doped ITO nanoparticles at 100 K and 300 K.

  2. Microstructure, ferromagnetic and photoluminescence properties of ITO and Cr doped ITO nanoparticles using solid state reaction

    Science.gov (United States)

    Babu, S. Harinath; Kaleemulla, S.; Rao, N. Madhusudhana; Rao, G. Venugopal; Krishnamoorthi, C.

    2016-11-01

    Indium-tin-oxide (ITO) (In0.95Sn0.05)2O3 and Cr doped indium-tin-oxide (In0.90Sn0.05Cr0.05)2O3 nanoparticles were prepared using simple low cost solid state reaction method and characterized by different techniques to study their structural, optical and magnetic properties. Microstructures, surface morphology, crystallite size of the nanoparticles were studied using X-ray diffractometer (XRD), field emission scanning electron microscope (FE-SEM). From these methods it was found that the particles were about 45 nm. Chemical composition and valence states of the nanoparticles were studied using energy dispersive analysis of X-rays (EDAX) and X-ray photoelectron spectroscopy (XPS). From these techniques it was observed that the elements of indium, tin, chromium and oxygen were present in the system in appropriate ratios and they were in +3, +4, +3 and -2 oxidation states. Raman studies confirmed that the nanoparticle were free from unintentional impurities. Two broad emission peaks were observed at 330 nm and 460 nm when excited wavelength of 300 nm. Magnetic studies were carried out at 300 K and 100 K using vibrating sample magnetometer (VSM) and found that the ITO nanoparticles were ferromagnetic at 100 K and 300 K. Where-as the room temperature ferromagnetism completely disappeared in Cr doped ITO nanoparticles at 100 K and 300 K.

  3. Aromatic C-Nitroso Compounds and Their Dimers: A Model for Probing the Reaction Mechanisms in Crystalline Molecular Solids

    Directory of Open Access Journals (Sweden)

    Ivana Biljan

    2017-12-01

    Full Text Available This review is focused on the dimerization and dissociation of aromatic C-nitroso compounds and their dimers, the reactions that could be used as a convenient model for studying the thermal organic solid-state reaction mechanisms. This molecular model is simple because it includes formation or breaking of only one covalent bond between two nitrogen atoms. The crystalline molecular solids of nitroso dimers (azodioxides dissociate by photolysis under the cryogenic conditions, and re-dimerize by slow warming. The thermal re-dimerization reaction is examined under the different topotactic conditions in crystals: disordering, surface defects, and phase transformations. Depending on the conditions, and on the molecular structure, aromatic C-nitroso compounds can associate to form one-dimensional polymeric structures and are able to self-assemble on gold surfaces.

  4. Removal of triclosan via peroxidases-mediated reactions in water: Reaction kinetics, products and detoxification

    International Nuclear Information System (INIS)

    Li, Jianhua; Peng, Jianbiao; Zhang, Ya; Ji, Yuefei; Shi, Huanhuan; Mao, Liang; Gao, Shixiang

    2016-01-01

    Highlights: • Enzymatic treatment of triclosan in water by soybean and horseradish peroxidases. • pH, H_2O_2 concentration and enzyme dosage affected the removal efficiency of TCS. • The removal of TCS by SBP was more efficient than that of HRP. • K_C_A_T and K_C_A_T/K_M values for SBP toward TCS were much higher than those for HRP. • Polymers formed via radical coupling mechanism were nontoxic to the growth of alga. - Abstract: This study investigated and compared reaction kinetics, product characterization, and toxicity variation of triclosan (TCS) removal mediated by soybean peroxidase (SBP), a recognized potential peroxidase for removing phenolic pollutants, and the commonly used horseradish peroxidase (HRP) with the goal of assessing the technical feasibility of SBP-catalyzed removal of TCS. Reaction conditions such as pH, H_2O_2 concentration and enzyme dosage were found to have a strong influence on the removal efficiency of TCS. SBP can retain its catalytic ability to remove TCS over broad ranges of pH and H_2O_2 concentration, while the optimal pH and H_2O_2 concentration were 7.0 and 8 μM, respectively. 98% TCS was removed with only 0.1 U mL"−"1 SBP in 30 min reaction time, while an HRP dose of 0.3 U mL"−"1 was required to achieve the similar conversion. The catalytic performance of SBP towards TCS was more efficient than that of HRP, which can be explained by catalytic rate constant (K_C_A_T) and catalytic efficiency (K_C_A_T/K_M) for the two enzymes. MS analysis in combination with quantum chemistry computation showed that the polymerization products were generated via C−C and C−O coupling pathways. The polymers were proved to be nontoxic through growth inhibition of green alga (Scenedesmus obliquus). Taking into consideration of the enzymatic treatment cost, SBP may be a better alternative to HRP upon the removal and detoxification of TCS in water/wastewater treatment.

  5. Removal of triclosan via peroxidases-mediated reactions in water: Reaction kinetics, products and detoxification

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jianhua; Peng, Jianbiao [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023 (China); Zhang, Ya [Nanjing Institute of Environmental Sciences, Ministry of Environmental Protection of the People’s Republic of China, Nanjing 210042 (China); Ji, Yuefei [College of Resources and Environmental Science, Nanjing Agricultural University, Nanjing 210095 (China); Shi, Huanhuan; Mao, Liang [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023 (China); Gao, Shixiang, E-mail: ecsxg@nju.edu.cn [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023 (China)

    2016-06-05

    Highlights: • Enzymatic treatment of triclosan in water by soybean and horseradish peroxidases. • pH, H{sub 2}O{sub 2} concentration and enzyme dosage affected the removal efficiency of TCS. • The removal of TCS by SBP was more efficient than that of HRP. • K{sub CAT} and K{sub CAT}/K{sub M} values for SBP toward TCS were much higher than those for HRP. • Polymers formed via radical coupling mechanism were nontoxic to the growth of alga. - Abstract: This study investigated and compared reaction kinetics, product characterization, and toxicity variation of triclosan (TCS) removal mediated by soybean peroxidase (SBP), a recognized potential peroxidase for removing phenolic pollutants, and the commonly used horseradish peroxidase (HRP) with the goal of assessing the technical feasibility of SBP-catalyzed removal of TCS. Reaction conditions such as pH, H{sub 2}O{sub 2} concentration and enzyme dosage were found to have a strong influence on the removal efficiency of TCS. SBP can retain its catalytic ability to remove TCS over broad ranges of pH and H{sub 2}O{sub 2} concentration, while the optimal pH and H{sub 2}O{sub 2} concentration were 7.0 and 8 μM, respectively. 98% TCS was removed with only 0.1 U mL{sup −1} SBP in 30 min reaction time, while an HRP dose of 0.3 U mL{sup −1} was required to achieve the similar conversion. The catalytic performance of SBP towards TCS was more efficient than that of HRP, which can be explained by catalytic rate constant (K{sub CAT}) and catalytic efficiency (K{sub CAT}/K{sub M}) for the two enzymes. MS analysis in combination with quantum chemistry computation showed that the polymerization products were generated via C−C and C−O coupling pathways. The polymers were proved to be nontoxic through growth inhibition of green alga (Scenedesmus obliquus). Taking into consideration of the enzymatic treatment cost, SBP may be a better alternative to HRP upon the removal and detoxification of TCS in water

  6. Microbial diversity and dynamics during methane production from municipal solid waste

    Energy Technology Data Exchange (ETDEWEB)

    Bareither, Christopher A., E-mail: christopher.bareither@colostate.edu [Civil and Environmental Engineering, Colorado State University, Ft. Collins, CO 80532 (United States); Geological Engineering, University of Wisconsin-Madison, Madison, WI 53706 (United States); Wolfe, Georgia L., E-mail: gwolfe@wisc.edu [Bacteriology, University of Wisconsin-Madison, Madison, WI 53706 (United States); McMahon, Katherine D., E-mail: tmcmahon@engr.wisc.edu [Bacteriology, Civil and Environmental Engineering, University of Wisconsin-Madison, Madison, WI 53706 (United States); Benson, Craig H., E-mail: chbenson@wisc.edu [Civil and Environmental Engineering, Geological Engineering, University of Wisconsin-Madison, Madison, WI 53706 (United States)

    2013-10-15

    Highlights: ► Similar bacterial communities developed following different start-up operation. ► Total methanogens in leachate during the decelerated methane phase reflected overall methane yield. ► Created correlations between methanogens, methane yield, and available substrate. ► Predominant bacteria identified with syntrophic polysaccharide degraders. ► Hydrogenotrophic methanogens were dominant in the methane generation process. - Abstract: The objectives of this study were to characterize development of bacterial and archaeal populations during biodegradation of municipal solid waste (MSW) and to link specific methanogens to methane generation. Experiments were conducted in three 0.61-m-diameter by 0.90-m-tall laboratory reactors to simulate MSW bioreactor landfills. Pyrosequencing of 16S rRNA genes was used to characterize microbial communities in both leachate and solid waste. Microbial assemblages in effluent leachate were similar between reactors during peak methane generation. Specific groups within the Bacteroidetes and Thermatogae phyla were present in all samples and were particularly abundant during peak methane generation. Microbial communities were not similar in leachate and solid fractions assayed at the end of reactor operation; solid waste contained a more abundant bacterial community of cellulose-degrading organisms (e.g., Firmicutes). Specific methanogen populations were assessed using quantitative polymerase chain reaction. Methanomicrobiales, Methanosarcinaceae, and Methanobacteriales were the predominant methanogens in all reactors, with Methanomicrobiales consistently the most abundant. Methanogen growth phases coincided with accelerated methane production, and cumulative methane yield increased with increasing total methanogen abundance. The difference in methanogen populations and corresponding methane yield is attributed to different initial cellulose and hemicellulose contents of the MSW. Higher initial cellulose and

  7. Microbial diversity and dynamics during methane production from municipal solid waste

    International Nuclear Information System (INIS)

    Bareither, Christopher A.; Wolfe, Georgia L.; McMahon, Katherine D.; Benson, Craig H.

    2013-01-01

    Highlights: ► Similar bacterial communities developed following different start-up operation. ► Total methanogens in leachate during the decelerated methane phase reflected overall methane yield. ► Created correlations between methanogens, methane yield, and available substrate. ► Predominant bacteria identified with syntrophic polysaccharide degraders. ► Hydrogenotrophic methanogens were dominant in the methane generation process. - Abstract: The objectives of this study were to characterize development of bacterial and archaeal populations during biodegradation of municipal solid waste (MSW) and to link specific methanogens to methane generation. Experiments were conducted in three 0.61-m-diameter by 0.90-m-tall laboratory reactors to simulate MSW bioreactor landfills. Pyrosequencing of 16S rRNA genes was used to characterize microbial communities in both leachate and solid waste. Microbial assemblages in effluent leachate were similar between reactors during peak methane generation. Specific groups within the Bacteroidetes and Thermatogae phyla were present in all samples and were particularly abundant during peak methane generation. Microbial communities were not similar in leachate and solid fractions assayed at the end of reactor operation; solid waste contained a more abundant bacterial community of cellulose-degrading organisms (e.g., Firmicutes). Specific methanogen populations were assessed using quantitative polymerase chain reaction. Methanomicrobiales, Methanosarcinaceae, and Methanobacteriales were the predominant methanogens in all reactors, with Methanomicrobiales consistently the most abundant. Methanogen growth phases coincided with accelerated methane production, and cumulative methane yield increased with increasing total methanogen abundance. The difference in methanogen populations and corresponding methane yield is attributed to different initial cellulose and hemicellulose contents of the MSW. Higher initial cellulose and

  8. Sorption enhanced reaction process (SERP) for the production of hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Hufton, J.; Mayorga, S.; Gaffney, T.; Nataraj, S.; Rao, M.; Sircar, S. [Air Products and Chemicals, Inc., Allentown, PA (United States)

    1998-08-01

    The novel Sorption Enhanced Reaction Process has the potential to decrease the cost of hydrogen production by steam methane reforming. Current effort for development of this technology has focused on adsorbent development, experimental process concept testing, and process development and design. A preferred CO{sub 2} adsorbent, K{sub 2}CO{sub 3} promoted hydrotalcite, satisfies all of the performance targets and it has been scaled up for process testing. A separate class of adsorbents has been identified which could potentially improve the performance of the H{sub 2}-SER process. Although this material exhibits improved CO{sub 2} adsorption capacity compared to the HTC adsorbent, its hydrothermal stability must be improved. Single-step process experiments (not cyclic) indicate that the H{sub 2}-SER reactor performance during the reaction step improves with decreasing pressure and increasing temperature and steam to methane ratio in the feed. Methane conversion in the H{sub 2}-SER reactor is higher than for a conventional catalyst-only reactor operated at similar temperature and pressure. The reactor effluent gas consists of 90+% H{sub 2}, balance CH{sub 4}, with only trace levels (< 50 ppm) of carbon oxides. A best-case process design (2.5 MMSCFD of 99.9+% H{sub 2}) based on the HTC adsorbent properties and a revised SER process cycle has been generated. Economic analysis of this design indicates the process has the potential to reduce the H{sub 2} product cost by 25--31% compared to conventional steam methane reforming.

  9. One-step production of biodiesel from Nannochloropsis sp. on solid base Mg-Zr catalyst

    International Nuclear Information System (INIS)

    Li, Yuesong; Lian, Shuang; Tong, Dongmei; Song, Ruili; Yang, Wenyan; Fan, Yong; Qing, Renwei; Hu, Changwei

    2011-01-01

    Nannochloropsis sp., one kind of green microalgae cultivated autotrophically and axenically in laboratory, is used as raw material to produce biodiesel by one-step method in an amended reactor. The effects of several reaction parameters on transesterification over Mg-Zr solid base catalyst were investigated through both conventional method and one-step method. One-step method could give a higher yield of methyl ester than conventional two-step method, which demonstrates that the present one-step method is suitable for biodiesel production from the microalgae Nannochloropsis sp. Moreover, the present one-step method realizes the convenient in situ separation of catalyst from microalgae residue which can be easily used consequently, reducing the procedure units as well as the overall costs.

  10. Hydrogen production by gasification of municipal solid waste

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, R. III

    1994-05-20

    As fossil fuel reserves run lower and lower, and as their continued widespread use leads toward numerous environmental problems, the need for clean and sustainable energy alternatives becomes ever clearer. Hydrogen fuel holds promise as such as energy source, as it burns cleanly and can be extracted from a number of renewable materials such as municipal solid waste (MSW), which can be considered largely renewable because of its high content of paper and biomass-derived products. A computer model is being developed using ASPEN Plus flow sheeting software to simulate a process which produces hydrogen gas from MSW; the model will later be used in studying the economics of this process and is based on an actual Texaco coal gasification plant design. This paper gives an overview of the complete MSW gasification process, and describes in detail the way in which MSW is modeled by the computer as a process material. In addition, details of the gasifier unit model are described; in this unit modified MSW reacts under pressure with oxygen and steam to form a mixture of gases which include hydrogen.

  11. Sorption Enhanced Reaction Process (SERP) for production of hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Anand, M.; Hufton, J.; Mayorga, S. [Air Products and Chemicals, Inc., Allentown, PA (United States)] [and others

    1996-10-01

    Sorption Enhanced Reaction Process (SERP) is a novel process that is being developed for the production of lower cost hydrogen by steam-methane reforming (SMR). In this process the reaction of methane with steam is carried out in the presence of an admixture of a catalyst and a selective adsorbent for carbon dioxide. The key consequences of SERP are: (i) reformation reaction is carried out at a significantly lower temperature (300-500{degrees}C) than that in a conventional SMR reactor (800-1100{degrees}C), while achieving the same conversion of methane to hydrogen, (ii) the product hydrogen is obtained at reactor pressure (200-400 psig) and at 98+% purity directly from the reactor (compared to only 70-75% H{sub 2} from conventional SMR reactor), (iii) downstream hydrogen purification step is either eliminated or significantly reduced in size. The first phase of the program has focused on the development of a sorbent for CO{sub 2} which has (a) reversible CO{sub 2} capacity >0.3 mmol/g at low partial pressures of CO{sub 2} (0.1 - 1.0 atm) in the presence of excess steam (pH{sub 2}O/pCO{sub 2}>20) at 400-500{degrees}C and (b) fast sorption-desorption kinetics for CO{sub 2}, at 400-500{degrees}C. Several families of supported sorbents have been identified that meet the target CO{sub 2} capacity. A few of these sorbents have been tested under repeated sorption/desorption cycles and extended exposure to high pressure steam at 400-500{degrees}C. One sorbent has been scaled up to larger quantities (2-3 kg) and tested in the laboratory process equipment for sorption and desorption kinetics of CO{sub 2}. The CO{sub 2}, sorption and desorption kinetics are desirably fast. This was a critical path item for the first phase of the program and now has been successfully demonstrated. A reactor has been designed that will allow nearly isothermal operation for SERP-SMR. This reactor was integrated into an overall process flow diagram for the SERP-SMR process.

  12. Transfusion reactions in pediatric compared with adult patients: a look at rate, reaction type, and associated products.

    Science.gov (United States)

    Oakley, Fredrick D; Woods, Marcella; Arnold, Shanna; Young, Pampee P

    2015-03-01

    The majority of reports on transfusion reactions address adult patients. Less is known about the types, incidence, and other clinical details of transfusion reactions in pediatric populations. Furthermore, to our knowledge, there have been no previous reports directly comparing these aspects between adults and pediatric patient populations to assess if there are differences. Between the period of January 1, 2011, and February 1, 2013, all reported adult and pediatric transfusion reactions at Vanderbilt University Medical Center (VUMC) were evaluated by transfusion medicine clinical service. The information was subsequently shared with the hemovigilance database. Data provided to hemovigilance included age, sex, blood product associated with the reaction, severity of the reaction, and the type of transfusion reactions. These were collated with hospital and blood bank information system-acquired data on overall admission and product transfusion. A total of 133,671 transfusions were performed at VUMC during the study period including 20,179 platelet (PLT) transfusions, 31,605 plasma transfusions, 79,933 red blood cell (RBC) transfusions, and 2154 cryoprecipitate transfusions. Over the same period, 108 pediatric and 277 adult transfusion reactions were recorded. This corresponds to an incidence of 6.2 reactions per 1000 transfusions within the pediatric (age reactions per 1000 transfusions within the adult population. In both adult and pediatric populations, transfusion reactions were most commonly associated with PLT, followed by RBC, and then plasma transfusions. Within the pediatric population, subset analysis identified multiple differences when compared to the adult population, including an increased incidence of allergic transfusion reactions (2.7/1000 vs. 1.1/1000, p reactions (1.9/1000 vs. 0.47/1000, p reactions (0.29/1000 vs. 0.078/1000, p reaction incidence was the same between sexes in adults, in pediatric patients, reactions were more common in male

  13. Study of the obtainment of Mo_2C by gas-solid reaction in a fixed and rotary bed reactor

    International Nuclear Information System (INIS)

    Araujo, C.P.B. de; Souza, C.P. de; Souto, M.V.M.; Barbosa, C.M.; Frota, A.V.V.M.

    2016-01-01

    Carbides' synthesis via gas-solid reaction overcomes many of the difficulties found in other processes, requiring lower temperatures and reaction times than traditional metallurgic routes, for example. In carbides' synthesis in fixed bed reactors (FB) the solid precursor is permeated by the reducing/carburizing gas stream forming a packed bed without mobility. The use of a rotary kiln reactor (RK) adds a mixing character to this process, changing its fluid-particle dynamics. In this work ammonium molybdate was subjected to carbo-reduction reaction (CH4 / H2) in both reactors under the same gas flow (15L / h) and temperature (660 ° C) for 180 minutes. Complete conversion was observed Mo2C (dp = 18.9nm modal particles sizes' distribution) in the fixed bed reactor. In the RK reactor this conversion was only partial (∼ 40%) and Mo2C and MoO3 (34nm dp = bimodal) could be observed on the produced XRD pattern. Partial conversion was attributed to the need to use higher solids loading in the reactor CR (50% higher) to avoid solids to centrifuge. (author)

  14. Calculations of long-lived isomer production in neutron reactions

    International Nuclear Information System (INIS)

    Chadwick, M.B.; Young, P.G.

    1992-01-01

    We present theoretical calculations for the production of the long-lived isomers 93m Nb (1/2-, 16 yr), 121m Sn (11/2-, 55 yr), 166m Ho (7-, 1200 yr), 184m Re (8+, 165 d), 186m Re (8+, 2x10 5 yr), 178 Hf (16+, 31 yr), 179m Hf (25/2-, 25 d), and 192m Ir (9+, 241 yr), all of which pose potential radiation activation problems in nuclear fusion reactors if produced in 14-MeV neutron-induced reactions. We consider (n,2n), (n,n'), and (n,γ) production modes and compare our results both with experimental data (where available) and systematics. We also investigate the dependence of the isomeric cross section ratio on incident neutron energy for the isomers under consideration. The statistical Hauser-Feshbach plus preequilibrium code GNASH was used for the calculations. Where discrete state experimental information was lacking, rotational band members above the isomeric state, which can be justified theoretically but have not been experimentally resolved, were reconstructed. (author). 16 refs, 10 figs, 4 tabs

  15. Solar Thermochemical Hydrogen Production via Terbium Oxide Based Redox Reactions

    Directory of Open Access Journals (Sweden)

    Rahul Bhosale

    2016-01-01

    Full Text Available The computational thermodynamic modeling of the terbium oxide based two-step solar thermochemical water splitting (Tb-WS cycle is reported. The 1st step of the Tb-WS cycle involves thermal reduction of TbO2 into Tb and O2, whereas the 2nd step corresponds to the production of H2 through Tb oxidation by water splitting reaction. Equilibrium compositions associated with the thermal reduction and water splitting steps were determined via HSC simulations. Influence of oxygen partial pressure in the inert gas on thermal reduction of TbO2 and effect of water splitting temperature (TL on Gibbs free energy related to the H2 production step were examined in detail. The cycle (ηcycle and solar-to-fuel energy conversion (ηsolar-to-fuel efficiency of the Tb-WS cycle were determined by performing the second-law thermodynamic analysis. Results obtained indicate that ηcycle and ηsolar-to-fuel increase with the decrease in oxygen partial pressure in the inert flushing gas and thermal reduction temperature (TH. It was also realized that the recuperation of the heat released by the water splitting reactor and quench unit further enhances the solar reactor efficiency. At TH=2280 K, by applying 60% heat recuperation, maximum ηcycle of 39.0% and ηsolar-to-fuel of 47.1% for the Tb-WS cycle can be attained.

  16. A Review of Microwave-Assisted Reactions for Biodiesel Production

    Directory of Open Access Journals (Sweden)

    Saifuddin Nomanbhay

    2017-06-01

    Full Text Available The conversion of biomass into chemicals and biofuels is an active research area as trends move to replace fossil fuels with renewable resources due to society’s increased concern towards sustainability. In this context, microwave processing has emerged as a tool in organic synthesis and plays an important role in developing a more sustainable world. Integration of processing methods with microwave irradiation has resulted in a great reduction in the time required for many processes, while the reaction efficiencies have been increased markedly. Microwave processing produces a higher yield with a cleaner profile in comparison to other methods. The microwave processing is reported to be a better heating method than the conventional methods due to its unique thermal and non-thermal effects. This paper provides an insight into the theoretical aspects of microwave irradiation practices and highlights the importance of microwave processing. The potential of the microwave technology to accomplish superior outcomes over the conventional methods in biodiesel production is presented. A green process for biodiesel production using a non-catalytic method is still new and very costly because of the supercritical condition requirement. Hence, non-catalytic biodiesel conversion under ambient pressure using microwave technology must be developed, as the energy utilization for microwave-based biodiesel synthesis is reported to be lower and cost-effective.

  17. Measurement of charmed particle production in hadronic reactions

    CERN Multimedia

    2002-01-01

    The aim of the experiment is to measure the production cross-section for charmed particles in hadronic reactions, study their production mechanism, and search for excited charmed hadrons.\\\\ \\\\ Charmed Mesons and Baryons will be measured in $\\pi$ and $p$ interactions on Beryllium between 100 and 200 GeV/c. The trigger will be on an electron from the leptonic decay of one charmed particle by signals from the Cerenkov counter (Ce), the electron trigger calorimeter (eCal), scintillation counters, and proportional wire chambers. The accompanying charmed particle will be measured via its hadronic decay in a two-stage magnetic spectrometer with drift chambers (arms 2, 3a, 3b, 3c), two large-area multicell Cerenkov counters (C2, C3) and a large-area shower counter ($\\gamma$-CAL). The particles which can be measured and identified include $\\gamma, e, \\pi^{\\pm}, \\pi^{0}, K^{\\pm}, p, \\bar{p}$ so that a large number of hadronic decay modes of charmed particles can be studied. \\\\ \\\\ A silicon counter telescope with 5 $\\m...

  18. Niobium carbide synthesis by solid-gas reaction using a rotating cylinder reactor

    International Nuclear Information System (INIS)

    Fontes, F.A.O.; Gomes, K.K.P.; Oliveira, S.A.; Souza, C.P.; Sousa, J.F.; Rio Grande do Norte Univ., Natal, RN

    2004-01-01

    A rotating cylinder reactor was designed for the synthesis of niobium carbide powders at 1173 K. Niobium carbide, NbC, was prepared by carbothermal reduction starting from commercial niobium pentoxide powders. The reactor was heated using a custom-made, two-part, hinged, electric furnace with programmable temperature control. The design and operational details of the reactor are presented. The longitudinal temperature gradient inside the reactor was determined. Total reaction time was monitored by a gas chromatograph equipped with an FID detector for determination of methane concentrations. The results show that time of reaction depended on rotation speed. NbC was also prepared in a static-bed alumina reactor using the same conditions as in the previous case. The niobium carbide powders were characterized by X-ray diffraction and compared with commercially available products. Morphological, particle size distribution and surface area analyses were obtained using SEM, LDPS and BET, respectively. Therefore, the present study offers a significant technological contribution to the synthesis of NbC powders in a rotating cylinder reactor. (author)

  19. Thermodynamic analysis and experimental study on the chlorination of uranium oxide by gas-solid reaction

    International Nuclear Information System (INIS)

    Shin, Y.J.; Kim, I.S.; Shin, H.S.; Ro, S.G.; Park, H.S.

    1998-01-01

    In order to determine the operating condition of an uranium chlorination process with U 3 O 8 -C-Cl 2 system, the experimental conditions have been evaluated preliminarily by the thermochemical analysis and experimentally confirmed in this study. The dry-type chlorination of U 3 O 8 occurs as irreversible and exothermic reaction and produces many kinds of chloride compounds such as UCl 3 , UCl 4 , UCl 5 , and UCl 6 in the air and humidity controlled argon environment. Taking account of Gibbs free energy and vapor pressure for various chloride compounds, the proper temperature range of chlorination appears to be 863 to 953 K in aspects of increasing reaction rate and the yield of nonvolatile product. In the course of the experimental confirmation the powder of U 3 O 8 is perfectly converted into uranium chlorides within 4 hours above 863 K, and then the maximum fraction of uranium chloride remaining in the reactor is about 30% of total conversion mass. (author)

  20. Chemical Reaction and Flow Modeling in Fullerene and Nanotube Production

    Science.gov (United States)

    Scott, Carl D.; Farhat, Samir; Greendyke, Robert B.

    2004-01-01

    The development of processes to produce fullerenes and carbon nanotubes has largely been empirical. Fullerenes were first discovered in the soot produced by laser ablation of graphite [1]and then in the soot of electric arc evaporated carbon. Techniques and conditions for producing larger and larger quantities of fullerenes depended mainly on trial and error empirical variations of these processes, with attempts to scale them up by using larger electrodes and targets and higher power. Various concepts of how fullerenes and carbon nanotubes were formed were put forth, but very little was done based on chemical kinetics of the reactions. This was mainly due to the complex mixture of species and complex nature of conditions in the reactors. Temperatures in the reactors varied from several thousand degrees Kelvin down to near room temperature. There are hundreds of species possible, ranging from atomic carbon to large clusters of carbonaceous soot, and metallic catalyst atoms to metal clusters, to complexes of metals and carbon. Most of the chemical kinetics of the reactions and the thermodynamic properties of clusters and complexes have only been approximated. In addition, flow conditions in the reactors are transient or unsteady, and three dimensional, with steep spatial gradients of temperature and species concentrations. All these factors make computational simulations of reactors very complex and challenging. This article addresses the development of the chemical reaction involved in fullerene production and extends this to production of carbon nanotubes by the laser ablation/oven process and by the electric arc evaporation process. In addition, the high-pressure carbon monoxide (HiPco) process is discussed. The article is in several parts. The first one addresses the thermochemical aspects of modeling; and considers the development of chemical rate equations, estimates of reaction rates, and thermodynamic properties where they are available. The second part

  1. Solid-state reaction synthesis and aqueous durability of Ce-doped zirconolite-rich ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Guanjun [State Key Laboratory Cultivation Base for Nonmetal Composite and Functional Materials, Southwest University of Science and Technology, Mianyang, Sichuan 621010 (China); Zhang, Kuibao, E-mail: xiaobao320@163.com [State Key Laboratory Cultivation Base for Nonmetal Composite and Functional Materials, Southwest University of Science and Technology, Mianyang, Sichuan 621010 (China); Yin, Dan [State Key Laboratory Cultivation Base for Nonmetal Composite and Functional Materials, Southwest University of Science and Technology, Mianyang, Sichuan 621010 (China); Zhang, Haibin, E-mail: hbzhang@imr.ac.cn [Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900 (China)

    2015-11-15

    In this study, Ce-doped zirconolite-rich ceramics were prepared by solid-state reaction process using cerium as the surrogate of tetravalence actinide nuclide. The occupancy of Ce in the waste forms was investigated. The aqueous durability of Ce-doped zirconolite-rich ceramic was examined as well. The results show that zirconolite and pseudobrookite coexisted after being sintered at 1200 °C for 6 h. Meanwhile, perovskite is inevitable generated during the process. CeO{sub 2} can be successfully incorporated into the lattice structure of the zirconolite-rich ceramics. The maximum containing capacity of CeO{sub 2} is up to 14.95 wt% or y = 0.4. The normalized elemental leaching rates of Ce and Ca are fairly constant in low values of 1.2 × 10{sup −6} and 2.3 × 10{sup −2} g m{sup −2} d{sup −1} after 28 days. The normalized leaching rate of Fe is also in a low value of 2.9 × 10{sup −4} g m{sup −2} d{sup −1} after 7 days. - Highlights: • Ce-doped zirconolite-rich ceramic was produced at 1200 °C. • Pseudobrookite-type Fe{sub 2}TiO{sub 5} was employed to incorporate Fe element. • Ce{sup 3+} and Ce{sup 4+} coexisted in the Ce-doped zirconolite-rich waste form after being sintered at 1200 °C for 6 h. • The leaching rate of Ca was relatively higher than that of borosilicate glasses.

  2. A novel mesoporous sulfated zirconium solid acid catalyst for Friedel-Crafts benzylation reaction

    International Nuclear Information System (INIS)

    Miao, Zhichao; Zhou, Jin; Zhao, Jinping; Liu, Dandan; Bi, Xu; Chou, Lingjun; Zhuo, Shuping

    2017-01-01

    Highlights: • A novel mesoporous ZrO_2/SO_4"2"− has been prepared via a facile one-pot EISA strategy. • The M-ZrO_2/SO_4"2"− exhibited excellent textural and acidic properties. • The introduced S species were homogeneously dispersed in mesoporous skeleton. • The M-ZrO_2/SO_4"2"− exhibited excellent catalytic performance and reusability. - Abstract: In this paper, a novel mesoporous sulfated zirconium (M-ZrO_2/SO_4"2"−) has been gotten by one-pot evaporation-induced self-assembly (one-pot EISA) strategy. The SXRD, N_2-physisorption and TEM characterization techniques indicated that M-ZrO_2/SO_4"2"− possessed distinct mesostructure with big specific surface area (133.5 m"2 g"−"1), large pore volume (0.18 cm"3 g"−"1) and narrow pore size distribution (4.90 nm). Moreover, the existing states and the influence in mesostructure of introduced S species were detailedly investigated by the XRD, N_2-physisorption, TEM, TG-DSC, FT-IR and XPS techniques and the results showed that the S species, which existed as the type of SO_4"2"−, improved the textural properties of prepared materials. In addition, the NH_3-TPD and IR spectra of adsorbed pyridine indicated the existence of strong Brønsted and Lewis acid sites in M-ZrO_2/SO_4"2"− even evacuated at 400 °C. Furthermore, the M-ZrO_2/SO_4"2"− was used as a promise solid acid catalyst and displayed excellent catalytic performance and reusability in Friedel-Crafts benzylation reaction.

  3. Synthesis and characterization of ZnGa2O4 particles prepared by solid state reaction

    International Nuclear Information System (INIS)

    Can, Musa Mutlu; Hassnain Jaffari, G.; Aksoy, Seda; Shah, S. Ismat; Fırat, Tezer

    2013-01-01

    Highlights: ► Synthesis of ZnGa 2 O 4 particles produced from metallic Zn and Ga particles. ► The structural comparison of spinel and partially inverse spinel structure in ZnGa 2 O 4 . ► The Ga atoms occupied 13% of tetrahedral site in ZnGa 2 O 4 . ► The band gap, calculated from climate point of UV–visible, was found as 4.6 ± 0.1 eV. ► The optical analyses were shown defective ZnO structure in ZnGa 2 O 4 . - Abstract: We employed solid state reaction technique to synthesize ZnGa 2 O 4 particles, produced in steps of mixing/milling the ingredients in H 2 O following thermal treating under 1200 °C. We compare spinel and partially inverse spinel structure in ZnGa 2 O 4 particles using Rietveld refinement. Crystal structure of ZnGa 2 O 4 particles was identified with two structural phases; normal spinel structure and partially inverse spinel structure using Rietveld refinement. It is found that the partially inverse spinel structures occupy nearly 13% and the rest is normal spinel structure. The obtained X-ray diffraction data show that lattice constant and the position of Oxygen atoms remain almost constant in both structures. The characterization of the particles was also improved using X-ray photoelectron spectroscopy and Fourier transforms infrared spectroscopy measurements. The optical analyses were done with UV–visible spectroscopy. The band gap, calculated from climate point of UV–visible data, was found as 4.6 ± 0.1 eV. Despite no unexpected compound (such as ZnO and Ga 2 O 3 ) in the structure, the optical analyses were shown defective ZnO structure in ZnGa 2 O 4 .

  4. Advances in solid-catalytic and non-catalytic technologies for biodiesel production

    International Nuclear Information System (INIS)

    Islam, Aminul; Taufiq-Yap, Yun Hin; Chan, Eng-Seng; Moniruzzaman, M.; Islam, Saiful; Nabi, Md. Nurun

    2014-01-01

    Highlights: • The recent technologies for promoting biodiesel synthesis were elucidated. • The design of catalyst consideration of biodiesel production was proposed. • The recent advances and remaining difficulties in biodiesel synthesis were outlined. • The future research trend in biodiesel synthesis was highlighted. - Abstract: The insecure supply of fossil fuel coerces the scientific society to keep a vision to boost investments in the renewable energy sector. Among the many renewable fuels currently available around the world, biodiesel offers an immediate impact in our energy. In fact, a huge interest in related research indicates a promising future for the biodiesel technology. Heterogeneous catalyzed production of biodiesel has emerged as a preferred route as it is environmentally benign needs no water washing and product separation is much easier. The number of well-defined catalyst complexes that are able to catalyze transesterification reactions efficiently has been significantly expanded in recent years. The activity of catalysts, specifically in application to solid acid/base catalyst in transesterification reaction depends on their structure, strength of basicity/acidity, surface area as well as the stability of catalyst. There are various process intensification technologies based on the use of alternate energy sources such as ultrasound and microwave. The latest advances in research and development related to biodiesel production is represented by non-catalytic supercritical method and focussed exclusively on these processes as forthcoming transesterification processes. The latest developments in this field featuring highly active catalyst complexes are outlined in this review. The knowledge of more extensive research on advances in biofuels will allow a deeper insight into the mechanism of these technologies toward meeting the critical energy challenges in future

  5. PRODUCTION OF NEW BIOMASS/WASTE-CONTAINING SOLID FUELS

    Energy Technology Data Exchange (ETDEWEB)

    David J. Akers; Glenn A. Shirey; Zalman Zitron; Charles Q. Maney

    2001-04-20

    CQ Inc. and its team members (ALSTOM Power Inc., Bliss Industries, McFadden Machine Company, and industry advisors from coal-burning utilities, equipment manufacturers, and the pellet fuels industry) addressed the objectives of the Department of Energy and industry to produce economical, new solid fuels from coal, biomass, and waste materials that reduce emissions from coal-fired boilers. This project builds on the team's commercial experience in composite fuels for energy production. The electric utility industry is interested in the use of biomass and wastes as fuel to reduce both emissions and fuel costs. In addition to these benefits, utilities also recognize the business advantage of consuming the waste byproducts of customers both to retain customers and to improve the public image of the industry. Unfortunately, biomass and waste byproducts can be troublesome fuels because of low bulk density, high moisture content, variable composition, handling and feeding problems, and inadequate information about combustion and emissions characteristics. Current methods of co-firing biomass and wastes either use a separate fuel receiving, storage, and boiler feed system, or mass burn the biomass by simply mixing it with coal on the storage pile. For biomass or biomass-containing composite fuels to be extensively used in the U.S., especially in the steam market, a lower cost method of producing these fuels must be developed that includes both moisture reduction and pelletization or agglomeration for necessary fuel density and ease of handling. Further, this method of fuel production must be applicable to a variety of combinations of biomass, wastes, and coal; economically competitive with current fuels; and provide environmental benefits compared with coal. Notable accomplishments from the work performed in Phase I of this project include the development of three standard fuel formulations from mixtures of coal fines, biomass, and waste materials that can be used in

  6. CFD Model Of A Planar Solid Oxide Electrolysis Cell For Hydrogen Production From Nuclear Energy

    International Nuclear Information System (INIS)

    Grant L. Hawkes; James E. O'Brien; Carl M. Stoots; J. Stephen Herring

    2005-01-01

    A three-dimensional computational fluid dynamics (CFD) model has been created to model high temperature steam electrolysis in a planar solid oxide electrolysis cell (SOEC). The model represents a single cell as it would exist in an electrolysis stack. Details of the model geometry are specific to a stack that was fabricated by Ceramatec2, Inc. and tested at the Idaho National Laboratory. Mass, momentum, energy, and species conservation and transport are provided via the core features of the commercial CFD code FLUENT2. A solid-oxide fuel cell (SOFC) model adds the electrochemical reactions and loss mechanisms and computation of the electric field throughout the cell. The FLUENT SOFC user-defined subroutine was modified for this work to allow for operation in the SOEC mode. Model results provide detailed profiles of temperature, Nernst potential, operating potential, anode-side gas composition, cathode-side gas composition, current density and hydrogen production over a range of stack operating conditions. Mean model results are shown to compare favorably with experimental results obtained from an actual ten-cell stack tested at INL

  7. An overview of renewable hydrogen production from thermochemical process of oil palm solid waste in Malaysia

    International Nuclear Information System (INIS)

    Hosseini, Seyed Ehsan; Wahid, Mazlan Abdul; Ganjehkaviri, A.

    2015-01-01

    Highlights: • 40% of energy demand of Malaysia could be supplied by thermochemical process of PSR. • SCWG of PSR is preferable thermochemical process due to char and tar elimination. • Potential of H 2 production from SCWG of PSR is 1.05 × 10 10 kgH 2 per year in Malaysia. • Highly moisturized PSR could be used in hydrogen production by SCWG process. - Abstract: Hydrogen is one of the most promising energy carriers for the future of the world due to its tremendous capability of pollution reduction. Hydrogen utilization is free of toxic gases formation as well as carbon dioxide (CO 2 ) emission. Hydrogen production can be implemented using a wide variety of resources including fossil fuels, nuclear energy and renewable and sustainable energy (RSE). Amongst various RSE resources, biomass has great capacity to be employed for renewable hydrogen production. Hydrogen production from palm solid residue (PSR) via thermochemical process is a perfect candidate for waste-to-well strategy in palm oil mills in Malaysia. In this paper, various characteristics of hydrogen production from thermochemical process of PSR includes pyrolysis and gasification are reviewed. The annual oil palm fruits production in Malaysia is approximately 100 million tonnes which the solid waste of the fruits is capable to generate around 1.05 × 10 10 kgH 2 (1.26 EJ) via supercritical water gasification (SCWG) process. The ratio of energy output to energy input of SCWG process of PSR is about 6.56 which demonstrates the priority of SCWG to transform the energy of PSR into a high energy end product. The high moisture of PSR which is the most important barrier for its direct combustion, emerges as an advantage in thermochemical reactions and highly moisturized PSR (even more than 50%) is utilized directly in SCWG without application of any high cost drying process. Implementation of appropriate strategies could lead Malaysia to supply about 40% of its annual energy demand by hydrogen yield from

  8. Synthesis of GaN Nanorods by a Solid-State Reaction

    Directory of Open Access Journals (Sweden)

    Keyan Bao

    2010-01-01

    Full Text Available An atom-economical and eco-friendly chemical synthetic route was developed to synthesize wurtzite GaN nanorods by the reaction of NaNH2 and the as-synthesized orthorhombic GaOOH nanorods in a stainless steel autoclave at 600∘C. The lengths of the GaN nanorods are in the range of 400–600 nm and the diameters are about 80–150 nm. The process of orthorhombic GaOOH nanorods transformation into wurtzite GaN nanorods was investigated by powder X-ray diffraction (XRD and field emission scanning electron microscope (FESEM, indicating that the GaN product retained essentially the same basic topological morphology in contrast to that of the GaOOH precursor. It was found that rhombohedral Ga2O3 was the intermediate between the starting orthorhombic GaOOH precursor and the final wurtzite GaN product. The photoluminescence measurements reveal that the as-prepared wurtzite GaN nanorods showed strong blue emission.

  9. Electron momentum spectroscopy of solids by the (e,2e) reaction

    International Nuclear Information System (INIS)

    Kheifets, A.S.; Vos, M.; Canney, S.A.; Guo, X.; McCarthy, I.E.

    1996-08-01

    Recent developments in (e,2e) momentum spectroscopy have resulted in the study of a diverse range of solid targets. These studies have revealed the electronic structure of solids in much more detail that was previously available using this technique. The method is now capable of producing quantitative data on energy-resolved momentum density of solids. A summary of these results is presented, in particular for aluminium, aluminium oxides and graphite. 26 refs., 9 figs

  10. Solid-State Fermentation vs Submerged Fermentation for the Production of l-Asparaginase.

    Science.gov (United States)

    Doriya, K; Jose, N; Gowda, M; Kumar, D S

    l-Asparaginase, an enzyme that catalyzes l-asparagine into aspartic acid and ammonia, has relevant applications in the pharmaceutical and food industry. So, this enzyme is used in the treatment of acute lymphoblastic leukemia, a malignant disorder in children. This enzyme is also able to reduce the amount of acrylamide found in carbohydrate-rich fried and baked foods which is carcinogenic to humans. The concentration of acrylamide in food can be reduced by deamination of asparagine using l-Asparaginase. l-Asparaginase is present in plants, animals, and microbes. Various microorganisms such as bacteria, yeast, and fungi are generally used for the production of l-Asparaginase as it is difficult to obtain the same from plants and animals. l-Asparaginase from bacteria causes anaphylaxis and other abnormal sensitive reactions. To overcome this, eukaryotic organisms such as fungi can be used for the production of l-Asparaginase. l-Asparaginase can be produced either by solid-state fermentation (SSF) or by submerged fermentation (SmF). SSF is preferred over SmF as it is cost effective, eco-friendly and it delivers high yield of enzyme. SSF process utilizes agricultural and industrial wastes as solid substrate. The contamination level is substantially reduced in SSF through low moisture content. Current chapter will discuss in detail the chemistry and applications of l-Asparaginase enzyme and various methods available for the production of the enzyme, especially focusing on the advantages and limitations of SSF and SmF processes. © 2016 Elsevier Inc. All rights reserved.

  11. Fabrication of a Schottky junction diode with direct growth graphene on silicon by a solid phase reaction

    International Nuclear Information System (INIS)

    Kalita, Golap; Hirano, Ryo; Ayhan, Muhammed E; Tanemura, Masaki

    2013-01-01

    We demonstrate fabrication of a Schottky junction diode with direct growth graphene on n-Si by the solid phase reaction approach. Metal-assisted crystallization of a-C thin film was performed to synthesize transfer-free graphene directly on a SiO 2 patterned n-Si substrate. Graphene formation at the substrate and catalyst layer interface is achieved in presence of a Co catalytic and CoO carbon diffusion barrier layer. The as-synthesized material shows a linear current–voltage characteristic confirming the metallic behaviour of the graphene structure. The direct grown graphene on n-Si substrate creates a Schottky junction with a potential barrier of 0.44 eV and rectification diode characteristic. Our finding shows that the directly synthesized graphene on Si substrate by a solid phase reaction process can be a promising technique to fabricate an efficient Schottky junction device. (paper)

  12. Dynamics of O(3P) Reactions with Gaseous Liquid and Solid Hydrocarbons

    National Research Council Canada - National Science Library

    Hase, William L

    2006-01-01

    ...) were applied to model reactions, including 0 + ethane and related reactions. In the second phase, a semiempirical quantum chemistry method, PM3-SRP, was developed by modifying and reparametrizing the standard PM3 method to fit the ab initio data...

  13. Failure criterion effect on solid production prediction and selection of completion solution

    Directory of Open Access Journals (Sweden)

    Dariush Javani

    2017-12-01

    Full Text Available Production of fines together with reservoir fluid is called solid production. It varies from a few grams or less per ton of reservoir fluid posing only minor problems, to catastrophic amount possibly leading to erosion and complete filling of the borehole. This paper assesses solid production potential in a carbonate gas reservoir located in the south of Iran. Petrophysical logs obtained from the vertical well were employed to construct mechanical earth model. Then, two failure criteria, i.e. Mohr–Coulomb and Mogi–Coulomb, were used to investigate the potential of solid production of the well in the initial and depleted conditions of the reservoir. Using these two criteria, we estimated critical collapse pressure and compared them to the reservoir pressure. Solid production occurs if collapse pressure is greater than pore pressure. Results indicate that the two failure criteria show different estimations of solid production potential of the studied reservoir. Mohr–Coulomb failure criterion estimated solid production in both initial and depleted conditions, where Mogi–Coulomb criterion predicted no solid production in the initial condition of reservoir. Based on Mogi–Coulomb criterion, the well may not require completion solutions like perforated liner, until at least 60% of reservoir pressure was depleted which leads to decrease in operation cost and time.

  14. By-products from the biodiesel chain as a substrate to citric acid production by solid-state fermentation.

    Science.gov (United States)

    Schneider, Manuella; Zimmer, Gabriela F; Cremonese, Ezequiel B; de C de S Schneider, Rosana; Corbellini, Valeriano A

    2014-07-01

    In this study, we propose the use of tung cake for the production of organic acids, with an emphasis on citric acid by solid-state fermentation. We evaluated the conditions of production and the by-products from the biodiesel chain as raw materials involved in this bioprocess. First, we standardized the conditions of solid-state fermentation in tung cake with and without residual fat and with different concentrations of glycerine using the fungus Aspergillus niger The solid-state fermentation process was monitored for 7 days considering the biomass growth and pH level. Citric acid production was determined by high-performance liquid chromatography. Fungal development was better in the crude tung cake, consisting of 20% glycerine. The highest citric acid yield was 350 g kg(-1) of biomass. Therefore, the solid-state fermentation of the tung cake with glycerine led to citric acid production using the Aspergillus niger fungus. © The Author(s) 2014.

  15. Hydrogen Oxidation Reaction at the Ni/YSZ Anode of Solid Oxide Fuel Cells from First Principles

    Science.gov (United States)

    Cucinotta, Clotilde S.; Bernasconi, Marco; Parrinello, Michele

    2011-11-01

    By means of ab initio simulations we here provide a comprehensive scenario for hydrogen oxidation reactions at the Ni/zirconia anode of solid oxide fuel cells. The simulations have also revealed that in the presence of water chemisorbed at the oxide surface, the active region for H oxidation actually extends beyond the metal/zirconia interface unraveling the role of water partial pressure in the decrease of the polarization resistance observed experimentally.

  16. Proposal on ''standardized high current solid targets for cyclotron production of diagnostic and therapeutic radionuclides''

    International Nuclear Information System (INIS)

    Suparman, Ibon

    2000-01-01

    The Center for the Development of Radioisotopes and Radiopharmaceuticals - National Nuclear Energy Agency (P2RR-BATAN) has one Cyclotron type CS-30 with maximum 30 MeV proton energy. It is used since 1990 for 201 Tl production. The main use of 201 Tl in Indonesia is for diagnosis and assessment of myocardial ischaemia, especially diagnosis of coronary artery disease, viability of the heart muscle and forecasting the outcome for patients with coronary disease. The Cyclotron facility is supported with a solid target station, two hot cells and the chemical equipment for electroplating. The yield of 201 Tl production currently achieved around 40-50%. The irradiation technique and chemical separation should be improved. We are also very interested in the development of the production of 103 Pd via 103 Rh (p,n) 103 Pd reaction. The objective of this proposal will support the main program of the National Nuclear Energy Agency (BATAN) in enhancement of health care and in providing Cyclotron produced radiopharmaceuticals for hospitals

  17. Analysis of reaction products formed in the gas phase reaction of E,E-2,4-hexadienal with atmospheric oxidants: Reaction mechanisms and atmospheric implications

    Science.gov (United States)

    Colmenar, I.; Martin, P.; Cabañas, B.; Salgado, S.; Martinez, E.

    2018-03-01

    An analysis of reaction products for the reaction of E,E-2,4-hexadienal with chlorine atoms (Cl) and OH and NO3 radicals has been carried out at the first time with the aim of obtaining a better understanding of the tropospheric reactivity of α,β-unsaturated carbonyl compounds. Fourier Transform Infrared (FTIR) spectroscopy and Gas Chromatography-Mass Spectrometry with a Time of Flight detector (GC-TOFMS) were used to carry out the qualitative and/or quantitative analyses. Reaction products in gas and particulate phase were observed from the reactions of E,E-2,4- hexadienal with all oxidants. E/Z-Butenedial and maleic anhydride were the main products identified in gas phase. E-butenedial calculated molar yield ranging from 4 to 10%. A significant amount of multifunctional compounds (chloro and hydroxy carbonyls) was identified. These compounds could be formed in particulate phase explaining the ∼90% of unaccounted carbon in gas phase. The reaction with Cl atoms in the presence of NOx with a long reaction time gave Peroxy Acetyl Nitrate (PAN) as an additional product, which is known for being an important specie in the generation of the photochemical smog. Nitrated compounds were the major organic products from the reaction with the NO3 radical. Based on the identified products, the reaction mechanisms have been proposed. In these mechanisms a double bond addition of the atmospheric oxidant at C4/C5 of E,E-2,4-hexadienal is the first step for tropospheric degradation.

  18. Convoy electron production by heavy ions in solids

    International Nuclear Information System (INIS)

    Sellin, I.A.

    1984-01-01

    The term convoy electron refers to those electrons ejected in fast ion-atom and ion-solid collisions closely matched in vector velocity to that of the incident heavy particles responsible for their ejection. Similarities and differences among electrons ejected into such states through binary electron capture to continuum and electron loss to continuum processes in single ion-atom encounters are compared and contrasted to more complex ejection processes occurring in solid targets. Puzzles posed by the apparent strong projectile Z dependence but weak emergent ion charge dependence of the yield in the case of solid targets are reviewed. Very recent progress in resolving these puzzles has been made by recent observations that the apparent mean free path for electron scattering out of the forward direction within the target is observed to be an order of magnitude greater than that for free electrons of equal velocity provided the projectile charge is high. 13 references, 2 figures, 1 table

  19. A novel mesoporous sulfated zirconium solid acid catalyst for Friedel-Crafts benzylation reaction

    Energy Technology Data Exchange (ETDEWEB)

    Miao, Zhichao; Zhou, Jin; Zhao, Jinping; Liu, Dandan; Bi, Xu [School of Chemical Engineering, Shandong University of Technology, Zibo, 255049 (China); Chou, Lingjun, E-mail: ljchou@licp.cas.cn [State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000 (China); Zhuo, Shuping, E-mail: zhuosp_academic@yahoo.com [School of Chemical Engineering, Shandong University of Technology, Zibo, 255049 (China)

    2017-07-31

    Highlights: • A novel mesoporous ZrO{sub 2}/SO{sub 4}{sup 2−} has been prepared via a facile one-pot EISA strategy. • The M-ZrO{sub 2}/SO{sub 4}{sup 2−} exhibited excellent textural and acidic properties. • The introduced S species were homogeneously dispersed in mesoporous skeleton. • The M-ZrO{sub 2}/SO{sub 4}{sup 2−} exhibited excellent catalytic performance and reusability. - Abstract: In this paper, a novel mesoporous sulfated zirconium (M-ZrO{sub 2}/SO{sub 4}{sup 2−}) has been gotten by one-pot evaporation-induced self-assembly (one-pot EISA) strategy. The SXRD, N{sub 2}-physisorption and TEM characterization techniques indicated that M-ZrO{sub 2}/SO{sub 4}{sup 2−} possessed distinct mesostructure with big specific surface area (133.5 m{sup 2} g{sup −1}), large pore volume (0.18 cm{sup 3} g{sup −1}) and narrow pore size distribution (4.90 nm). Moreover, the existing states and the influence in mesostructure of introduced S species were detailedly investigated by the XRD, N{sub 2}-physisorption, TEM, TG-DSC, FT-IR and XPS techniques and the results showed that the S species, which existed as the type of SO{sub 4}{sup 2−}, improved the textural properties of prepared materials. In addition, the NH{sub 3}-TPD and IR spectra of adsorbed pyridine indicated the existence of strong Brønsted and Lewis acid sites in M-ZrO{sub 2}/SO{sub 4}{sup 2−} even evacuated at 400 °C. Furthermore, the M-ZrO{sub 2}/SO{sub 4}{sup 2−} was used as a promise solid acid catalyst and displayed excellent catalytic performance and reusability in Friedel-Crafts benzylation reaction.

  20. Luminescence properties of dysprosium doped calcium magnesium silicate phosphor by solid state reaction method

    Energy Technology Data Exchange (ETDEWEB)

    Sahu, Ishwar Prasad, E-mail: ishwarprasad1986@gmail.com [School of Studies in Physics & Astrophysics, Pt. Ravishankar Shukla University, Raipur, C.G. 492010 (India); Chandrakar, Priya; Baghel, R.N.; Bisen, D.P.; Brahme, Nameeta [School of Studies in Physics & Astrophysics, Pt. Ravishankar Shukla University, Raipur, C.G. 492010 (India); Tamrakar, Raunak Kumar [Department of Applied Physics, Bhilai Institute of Technology, Durg, C.G. 491001 (India)

    2015-11-15

    Dysprosium doped calcium magnesium silicate (CaMgSi{sub 2}O{sub 6}:Dy{sup 3+}) white light emitting phosphor was synthesized by solid state reaction process. The crystal structure of sintered phosphor was monoclinic structure with space group C2/c. Chemical composition of the sintered CaMgSi{sub 2}O{sub 6}:Dy{sup 3+} phosphor was confirmed by EDX. The prepared CaMgSi{sub 2}O{sub 6}:Dy{sup 3+} phosphor was excited from 352 nm and their corresponding emission spectra were recorded at blue (470 nm), yellow (570 nm) and red (675 nm) line due to the {sup 4}F{sub 9/2} → {sup 6}H{sub 15/2}, {sup 4}F{sub 9/2} → {sup 6}H{sub 13/2}, {sup 4}F{sub 9/2} → {sup 6}H{sub 11/2} transitions of Dy{sup 3+} ions. The combination of these three emissions constituted as white light confirmed by the Commission Internationale de L'Eclairage (CIE) chromatic coordinate diagram. The possible mechanism of the white light emitting long lasting CaMgSi{sub 2}O{sub 6}:Dy{sup 3+} phosphor was also investigated. Investigation on afterglow property show that phosphor held fast and slow decay process. The peak of mechanoluminescence (ML) intensity increases linearly with increasing impact velocity of the moving piston. Thus the present investigation indicates that the local piezoelectricity-induced electron bombardment model is responsible to produce ML in prepared CaMgSi{sub 2}O{sub 6}:Dy{sup 3+} phosphor. - Highlights: • The crystal structure of CaMgSi{sub 2}O{sub 6}:Dy{sup 3+} phosphor is consistent with standard monoclinic structure. • CIE coordinates of CaMgSi{sub 2}O{sub 6}:Dy{sup 3+} phosphor is suitable as white light emitting phosphor. • The local piezoelectricity-induced electron bombardment model is responsible to produce ML in CaMgSi{sub 2}O{sub 6}:Dy{sup 3+} phosphor.

  1. A COMBINED REACTION/PRODUCT RECOVERY PROCESS FOR THE CONTINUOUS PRODUCTION OF BIODIESEL

    Energy Technology Data Exchange (ETDEWEB)

    Birdwell, J.F., Jr.; McFarlane, J.; Schuh, D.L.; Tsouris, C; Day, J.N. (Nu-Energie, LLC); Hullette, J.N. (Nu-Energie, LLC)

    2009-09-01

    Oak Ridge National Laboratory (ORNL) and Nu-Energie, LLC entered into a Cooperative Research And Development Agreement (CRADA) for the purpose of demonstrating and deploying a novel technology for the continuous synthesis and recovery of biodiesel from the transesterification of triglycerides. The focus of the work was the demonstration of a combination Couette reactor and centrifugal separator - an invention of ORNL researchers - that facilitates both product synthesis and recovery from reaction byproducts in the same apparatus. At present, transesterification of triglycerides to produce biodiesel is performed in batch-type reactors with an excess of a chemical catalyst, which is required to achieve high reactant conversions in reasonable reaction times (e.g., 1 hour). The need for long reactor residence times requires use of large reactors and ancillary equipment (e.g., feed and product tankage), and correspondingly large facilities, in order to obtain the economy of scale required to make the process economically viable. Hence, the goal of this CRADA was to demonstrate successful, extended operation of a laboratory-scale reactor/separator prototype to process typical industrial reactant materials, and to design, fabricate, and test a production-scale unit for deployment at the biodiesel production site. Because of its ease of operation, rapid attainment of steady state, high mass transfer and phase separation efficiencies, and compact size, a centrifugal contactor was chosen for intensification of the biodiesel production process. The unit was modified to increase the residence time from a few seconds to minutes*. For this application, liquid phases were introduced into the reactor as separate streams. One was composed of the methanol and base catalyst and the other was the soy oil used in the experiments. Following reaction in the mixing zone, the immiscible glycerine and methyl ester products were separated in the high speed rotor and collected from separate

  2. A COMBINED REACTION/PRODUCT RECOVERY PROCESS FOR THE CONTINUOUS PRODUCTION OF BIODIESEL

    International Nuclear Information System (INIS)

    Birdwell, J.F. Jr.; McFarlane, J.; Schuh, D.L.; Tsouris, C.; Day, J.N.; Hullette, J.N.

    2009-01-01

    Oak Ridge National Laboratory (ORNL) and Nu-Energie, LLC entered into a Cooperative Research And Development Agreement (CRADA) for the purpose of demonstrating and deploying a novel technology for the continuous synthesis and recovery of biodiesel from the transesterification of triglycerides. The focus of the work was the demonstration of a combination Couette reactor and centrifugal separator - an invention of ORNL researchers - that facilitates both product synthesis and recovery from reaction byproducts in the same apparatus. At present, transesterification of triglycerides to produce biodiesel is performed in batch-type reactors with an excess of a chemical catalyst, which is required to achieve high reactant conversions in reasonable reaction times (e.g., 1 hour). The need for long reactor residence times requires use of large reactors and ancillary equipment (e.g., feed and product tankage), and correspondingly large facilities, in order to obtain the economy of scale required to make the process economically viable. Hence, the goal of this CRADA was to demonstrate successful, extended operation of a laboratory-scale reactor/separator prototype to process typical industrial reactant materials, and to design, fabricate, and test a production-scale unit for deployment at the biodiesel production site. Because of its ease of operation, rapid attainment of steady state, high mass transfer and phase separation efficiencies, and compact size, a centrifugal contactor was chosen for intensification of the biodiesel production process. The unit was modified to increase the residence time from a few seconds to minutes*. For this application, liquid phases were introduced into the reactor as separate streams. One was composed of the methanol and base catalyst and the other was the soy oil used in the experiments. Following reaction in the mixing zone, the immiscible glycerine and methyl ester products were separated in the high speed rotor and collected from separate

  3. Determination of 68Ga production parameters by different reactions ...

    Indian Academy of Sciences (India)

    function of 68Zn(p, n)68Ga reaction was compared with the reported ... 2.1.1 Brief description of nuclear models applied for cross-section calculations ... tion of isotope impurities is not possible by chemical methods, so this reaction is.

  4. Kinetics of solid-gas reactions characterized by scanning AC nano-calorimetry with application to Zr oxidation

    International Nuclear Information System (INIS)

    Xiao, Kechao; Lee, Dongwoo; Vlassak, Joost J.

    2014-01-01

    Scanning AC nano-calorimetry is a recently developed experimental technique capable of measuring the heat capacity of thin-film samples of a material over a wide range of temperatures and heating rates. Here, we describe how this technique can be used to study solid-gas phase reactions by measuring the change in heat capacity of a sample during reaction. We apply this approach to evaluate the oxidation kinetics of thin-film samples of zirconium in air. The results confirm parabolic oxidation kinetics with an activation energy of 0.59 ± 0.03 eV. The nano-calorimetry measurements were performed using a device that contains an array of micromachined nano-calorimeter sensors in an architecture designed for combinatorial studies. We demonstrate that the oxidation kinetics can be quantified using a single sample, thus enabling high-throughput mapping of the composition-dependence of the reaction rate.

  5. Optimization of production of subtilisin in solid substrate ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-07-04

    Jul 4, 2008 ... Subtilisin being stable over a wide range of. pH and ... yield of this enzyme needs to be optimized for cost effective ... contrast to more biochemical environments, where the ... An example is the two-component regulatory .... fifth day onward in case of solid substrate using wheat ... The analysis of variance of.

  6. Evaluation of conidia production and mycelial growth in solid culture ...

    African Journals Online (AJOL)

    It is important to know the ability of native strains to carry out the process of sporulation and growth in different conditions and to determine their possible potential as biological control of pests of agricultural importance, mainly in citrus areas. The objective of this study was to evaluate five different solid culture media for the ...

  7. Production of Solid Fuel Briquettes from Agricultural and Wood ...

    African Journals Online (AJOL)

    Fibrous agricultural and wood waste materials have been compressed with suitable adhesive into solid fuel briquettes in a compressing machine, which was designed and constructed for this purpose. Nine samples of fibrous waste materials were prepared into different categories:- Category A (100% saw-dust, 100% ...

  8. Non-affine fields in solid-solid transformations: the structure and stability of a product droplet.

    Science.gov (United States)

    Paul, Arya; Sengupta, Surajit; Rao, Madan

    2014-01-08

    We describe the microstructure, morphology, and dynamics of growth of a droplet of martensite nucleating in a parent austenite during a solid-solid transformation, using a Landau theory written in terms of both conventional affine elastic deformations and non-affine deformations. Non-affineness, φ, serves as a source of strain incompatibility and screens long-ranged elastic interactions. It is produced wherever the local stress exceeds a threshold and anneals diffusively thereafter. Using a variational calculation, we find three types of stable solution (labeled I, II, and III) for the structure of the product droplet, depending on the stress threshold and the scaled mobilities of φ parallel and perpendicular to the parent-product interface. The profile of the non-affine field φ is different in these three solutions: I is characterized by a vanishingly small φ, II admits large values of φ localized in regions of high stress within the parent-product interface, and III is a structure in which φ completely wets the parent-product interface. The width l and size W of the twins follow the relation l is proportional to √W in solution I; this relation does not hold for II or III. We obtain a dynamical phase diagram featuring these solutions, and argue that they represent specific solid-state microstructures.

  9. ON THE SYNTHESIS OF MOLYBDENUM CARBIDE WITH COBALT ADDITION VIA GAS-SOLID REACTIONS IN A CH4/H2 ATMOSPHERE

    Directory of Open Access Journals (Sweden)

    C. P. B. Araujo

    Full Text Available Abstract Due to ever more severe environmental regulations regarding SOx, NOx and other pollutants' emissions, there has been an interest in developing new and improved catalysts for hydroprocessing reactions. Mo2C has been reported to display good selectivity and activity for those reactions, especially for HDS. Addition of another metal to the carbide structure may improve catalytic properties. Mo2C with low cobalt addition (2.5 and 5% was obtained via gas-solid reaction in a fixed bed reactor with CH4 (5%/H2 atmosphere. XRD and TG/DTA analysis of the precursors were carried out in order to understand its mass loss profile, doping metal presence and phase distributions. CoMoO4 as well as MoO3 were identified after calcining doped precursors at 600 °C/180min. SEM, XRD, XRF, TOC, BET and laser granulometric analysis of the reaction products were also performed. Compositions verified by XRF and theoretical values were compatible. At 700 °C both carbide (Mo2C and oxide (MoO2 phases are present, as identified in XRD analysis and observed by SEM. At 750 °C only single phase Mo2C was verified by XRD, indicating Co dispersion on the carbide matrix. Morphology at this temperature is compatible with pure Mo2C, though XRF indicates Co presence on the material.

  10. Surface Solid Dispersion and Solid Dispersion of Meloxicam: Comparison and Product Development.

    Science.gov (United States)

    Chaturvedi, Mayank; Kumar, Manish; Pathak, Kamla; Bhatt, Shailendra; Saini, Vipin

    2017-12-01

    Purpose: A comparative study was carried out between surface solid dispersion (SSD) and solid dispersion (SD) of meloxicam (MLX) to assess the solubility and dissolution enhancement approach and thereafter develop as patient friendly orodispersible tablet. Methods: Crospovidone (CPV), a hydrophilic carrier was selected for SSD preparation on the basis of 89% in- vitro MLX adsorption, 19% hydration capacity and high swelling index. SD on the other hand was made with PEG4000. Both were prepared by co-grinding and solvent evaporation method using drug: carrier ratios of 1:1, 1:4, and 1:8. Formulation SSDS3 (MLX: CPV in 1:8 ratio) made by solvent evaporation method showed t 50% of 28 min and 80.9% DE 50min which was higher in comparison to the corresponding solid dispersion, SDS3 (t 50% of 35min and 76.4% DE 50min ). Both SSDS3 and SDS3 were developed as orodispersible tablets and evaluated. Results: Tablet formulation F3 made with SSD3 with a disintegration time of 11 secs, by wetting time= 6 sec, high water absorption of 78%by wt and cumulative drug release of 97% proved to be superior than the tablet made with SD3. Conclusion: Conclusively, the SSD of meloxicam has the potential to be developed as fast acing formulation that can ensure almost complete release of drug.

  11. Surface Solid Dispersion and Solid Dispersion of Meloxicam: Comparison and Product Development

    Directory of Open Access Journals (Sweden)

    Mayank Chaturvedi

    2017-12-01

    Full Text Available Purpose: A comparative study was carried out between surface solid dispersion (SSD and solid dispersion (SD of meloxicam (MLX to assess the solubility and dissolution enhancement approach and thereafter develop as patient friendly orodispersible tablet. Methods: Crospovidone (CPV, a hydrophilic carrier was selected for SSD preparation on the basis of 89% in- vitro MLX adsorption, 19% hydration capacity and high swelling index. SD on the other hand was made with PEG4000. Both were prepared by co-grinding and solvent evaporation method using drug: carrier ratios of 1:1, 1:4, and 1:8. Formulation SSDS3 (MLX: CPV in 1:8 ratio made by solvent evaporation method showed t50% of 28 min and 80.9% DE50min which was higher in comparison to the corresponding solid dispersion, SDS3 (t50% of 35min and 76.4% DE50min. Both SSDS3 and SDS3 were developed as orodispersible tablets and evaluated. Results: Tablet formulation F3 made with SSD3 with a disintegration time of 11 secs, by wetting time= 6 sec, high water absorption of 78%by wt and cumulative drug release of 97% proved to be superior than the tablet made with SD3. Conclusion: Conclusively, the SSD of meloxicam has the potential to be developed as fast acing formulation that can ensure almost complete release of drug.

  12. Ecological toxicity estimation of solid waste products of Tekely Ore Mining and Processing Enterprise of OJSC 'Kaztsink' using biological testing methods

    International Nuclear Information System (INIS)

    Vetrinskaya, N.I.; Goldobina, E.A.; Kosmukhambetov, A.R.; Kulikova, O.V.; Ismailova, Zh.B.; Gurikova, N.D.; Kozlova, N.V.

    2001-01-01

    Results are examined of solid waste products estimation using methods of biological testing at testing-objects of different phylogenetic development levels (simple aqua animals, algae, supreme water plants). Correlation is found between lead and zinc content in the extract of leaching out and exact reaction of all under-test objects. Conclusion is made that performing of the complex express economical analysis is necessary using methods of biological testing of industrial waste products monitoring and other man-made pollutants. (author)

  13. Evaluation of the LTQ-Orbitrap mass spectrometer for the analysis of polymerase chain reaction products.

    Science.gov (United States)

    Manduzio, Hélène; Ezan, Eric; Fenaille, François

    2010-12-30

    We have investigated the potential and robustness of the off-line coupling of polymerase chain reaction (PCR) with electrospray ionization mass spectrometry (ESI-MS), for further applications in the screening of single-nucleotide polymorphisms (SNPs). This was based on recently reported data demonstrating that anion-exchange solid-phase extraction was the most efficient technique for efficiently desalting PCR products, with a recovery of ∼70%. Results showed that this purification approach efficiently removes almost all the chemicals commonly added to PCR buffers. ESI-MS analysis of a model 114-bp PCR product performed on the LTQ-Orbitrap instrument demonstrated that detection limits in the nM range along with an average mass measurement uncertainty of 9.15 ± 7.11 ppm can be routinely obtained using an external calibration. The PCR/ESI-MS platform was able to detect just a few copies of a targeted oligonucleotide. However, it was shown that if two PCR products are present in a mixture in a ratio higher than 10 to 1, the lower abundance one might not be reproducibly detected. Applications to SNPs demonstrated that an LTQ-Orbitrap with a resolution of 30 000 (at m/z 400) easily identified a single (A ↔ G) switch, i.e. a 16 Da difference, in binary mixtures of ∼ 35 kDa PCR products. Complementary experiments also showed that the combination of endonucleases and ESI-MS could be used to confirm base composition and sequence, and thus to screen for unknown polymorphisms in specific sequences. For example, a single (T ↔ A) switch (9 Da mass difference) was successfully identified in a 114-bp PCR product. Copyright © 2010 John Wiley & Sons, Ltd.

  14. Electrical and Dielectric Properties of Polyaniline and Polyaniline/Montmorillonite Nanocomposite Prepared by Solid Reaction Using Spectroscopy Impedance

    Directory of Open Access Journals (Sweden)

    Imene Bekri-Abbes

    2015-01-01

    Full Text Available The combination of two components with uniform distribution in nanoscale is expected to facilitate wider applications of the material. In this study, polyaniline (PAn and polyaniline/montmorillonite (Mt nanocomposite were prepared by solid reaction using persulfate of ammonium as oxidant. The phase composition and morphology of the nanocomposite were characterized by FTIR, UV-visible spectroscopy, X-ray diffractometer, thermal gravimetric analysis, and scanning electron microscopy. The electrical and dielectric properties were determined using spectroscopy impedance. The analysis of UV-visible and FTIR spectroscopy demonstrated that aniline chloride has been polymerized into PAn in its conducting emeraldine form. Thermogravimetric analysis suggested that PAn chains intercalated in the clay host are more thermally stable than those of free PAn prepared by solid-solid reaction. Electrical measurements were carried out using the complex impedance technique in the frequency range of 10−2 to 104 Hz at different temperatures. The ac conductivity data of different nanocomposites were analyzed as a function of frequency and temperature. It has been found that the incorporation of inorganic clay phase into polyaniline matrix has an effect on the electrical and dielectric properties of the nanomaterial.

  15. Arrowroot as a novel substrate for ethanol production by solid state simultaneous saccharification and fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Tian-xiang; Tang, Qing-li; Zhu, Zuo-hua [School of Chemical Engineering, Guizhou University, Guizhou, Guiyang 550003 (China); Wang, Feng [National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190 (China)

    2010-08-15

    Ethanol production from Canna edulis Ker was successfully carried out by solid state simultaneous saccharification and fermentation. The enzymatic hydrolysis conditions of C. edulis were optimized by Plackett-Burman design. The effect of inert carrier (corncob and rice bran) on ethanol fermentation and the kinetics of solid state simultaneous saccharification and fermentation was investigated. It was found that C. edulis was an alternative substrate for ethanol production, 10.1% (v/v) of ethanol concentration can attained when 40 g corncob and 10 g rice bran per 100 g C. edulis powder were added for ethanol fermentation. No shortage of fermentable sugars was observed during solid state simultaneous saccharification and fermentation. There was no wastewater produced in the process of ethanol production from C. edulis with solid state simultaneous saccharification and fermentation and the ethanol yield of more than 0.28 tonne per one tonne feedstock was achieved. This is first report for ethanol production from C. edulis powder. (author)

  16. Advanced fusion welding processes, solid state joining and a successful marriage. [production of aerospace structures

    Science.gov (United States)

    Miller, F. R.

    1972-01-01

    Joining processes for aerospace systems combine fusion welding and solid state joining during production of metal structures. Detailed characteristics of electron beam welding, plasma arc welding, diffusion welding, inertia welding and weldbond processes are discussed.

  17. Selective production of aromatics from alkylfurans over solid acid catalysts

    DEFF Research Database (Denmark)

    Wang, Dong; Dumesic, James A.; Osmundsen, Christian Mårup

    2013-01-01

    to deactivation by carbon deposition than do microporous materials. Results from Raman spectroscopy and the trend of turnover frequency with varying tungsten surface densities for a series of WOx-ZrO2 catalysts are consistent with previous investigations of other acid-catalyzed reactions; this suggests...

  18. Solid state reaction studies in Fe{sub 3}O{sub 4}–TiO{sub 2} system by diffusion couple method

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Zhongshan [State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, Beijing 100083 (China); School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Hu, Xiaojun, E-mail: huxiaojun@ustb.edu.cn [State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, Beijing 100083 (China); School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Xue, Xiangxin [School of Materials and Metallurgy, Northeastern University, Shenyang 110006 (China); Chou, Kuochih [State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, Beijing 100083 (China); School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083 (China)

    2013-12-15

    Highlights: •The solid state reactions of Fe2O3-TiO2 system was studied by the diffusion couple method. •Different products were formed by diffusion, and the FeTiO3 was more stable phase. •The inter-diffusion coefficients and diffusion activation energy were estimated. -- Abstract: The solid state reactions in Fe{sub 3}O{sub 4}–TiO{sub 2} system has been studied by diffusion couple experiments at 1323–1473 K, in which the oxygen partial pressure was controlled by the CO–CO{sub 2} gas mixture. The XRD analysis was used to confirm the phases of the inter-compound, and the concentration profiles were determined by electron probe microanalysis (EPMA). Based on the concentration profile of Ti, the inter-diffusion coefficients in Fe{sub 3}O{sub 4} phase, which were both temperature and concentration of Ti ions dependent, were calculated by the modified Boltzmann–Matano method. According to the relation between the thickness of diffusion layer and temperature, the diffusion coefficient of the Fe{sub 3}O{sub 4}–TiO{sub 2} system was obtained. According to the Arrhenius equation, the estimated diffusion activation energy was about 282.1 ± 18.8 kJ mol{sup −1}.

  19. Tannase production by Aspergillus aculeatus DBF9 through solid-state fermentation.

    Science.gov (United States)

    Banerjee, D; Mondal, K C; Pati, B R

    2007-06-01

    Tannase an industrially important enzyme was produced by Aspergillus aculeatus DBF9 through a solid-state fermentation (SSF). The organism produced good amount of enzyme and gallic acid in wheat bran among the solid substrate used in SSF. Maximum enzyme and gallic acid production occurred in 5% tannic acid after 72 h. Eighty percent initial substrate moisture and 30 degrees C temperature was found suitable for tannase production.

  20. Biogas production from the mechanically pretreated, liquid fraction of sorted organic municipal solid wastes.

    Science.gov (United States)

    Alvarado-Lassman, A; Méndez-Contreras, J M; Martínez-Sibaja, A; Rosas-Mendoza, E S; Vallejo-Cantú, N A

    2017-06-01

    The high liquid content in fruit and vegetable wastes makes it convenient to mechanically separate these wastes into mostly liquid and solid fractions by means of pretreatment. Then, the liquid fraction can be treated using a high-rate anaerobic biofilm reactor to produce biogas, simultaneously reducing the amount of solids that must be landfilled. In this work, the specific composition of municipal solid waste (MSW) in a public market was determined; then, the sorted organic fraction of municipal solid waste was treated mechanically to separate and characterize the mostly liquid and solid fractions. Then, the mesophilic anaerobic digestion for biogas production of the first fraction was evaluated. The anaerobic digestion resulted in a reduced hydraulic retention time of two days with high removal of chemical oxygen demand, that is, 88% on average, with the additional benefit of reducing the mass of the solids that had to be landfilled by about 80%.

  1. Radiation-induced reactions of amino acids adsorbed on solid surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Esquivel Kranksith, L.; Negron-Mendoza, A. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, UNAM. Cd. Universitaria, A.P. 70-543, 04510 Mexico D.F. (Mexico); Mosqueira, F.G. [Direcion General de Divulgacion de la Ciencia, Universidad Nacional Autonoma de Mexico, Cd. Universitaria, AP. 70-487 Mexico D.F. (Mexico); Ramos-Bernal, Sergio, E-mail: ramos@nucleares.unam.m [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, UNAM. Cd. Universitaria, A.P. 70-543, 04510 Mexico D.F. (Mexico)

    2010-07-21

    The purpose of this work is to study the adsorption of compounds such as amino acids on clays and carbon nanotubes (CNTs) as a possible phase in the chemical evolution that may have occurred on the primitive Earth or in extraterrestrial environments. We further study the behavior of amino acids adsorbed on these solid surfaces at different conditions of pH and levels of irradiation, simulating a high-radiation field at early Earth conditions. The relevance of this work is to explain the possible contribution of solids (clays and CNTs) as promoters of polymerization and as shields for the adsorbed organic compounds against external sources of energy. To this end, tryptophan, aspartic acid, and glutamic acid were adsorbed on fixed amounts of solid surfaces and were irradiated by a {sup 60}Co source for different periods of time at fixed dose rates. After irradiation, the amino acids were extracted from the solid and analyzed with UV and IR spectroscopes and high-performance liquid chromatography. The most efficient surface for adsorption of amino acids was clay, followed by CNTs. Studies of the gamma irradiation of amino acids adsorbed on clay (in the solid phase) show a low yield of recovery of the amino acid.

  2. Bimolecular reaction of CH3 + CO in solid p-H2: Infrared absorption of acetyl radical (CH3CO) and CH3-CO complex

    Science.gov (United States)

    Das, Prasanta; Lee, Yuan-Pern

    2014-06-01

    We have recorded infrared spectra of acetyl radical (CH3CO) and CH3-CO complex in solid para-hydrogen (p-H2). Upon irradiation at 248 nm of CH3C(O)Cl/p-H2 matrices, CH3CO was identified as the major product; characteristic intense IR absorption features at 2990.3 (ν9), 2989.1 (ν1), 2915.6 (ν2), 1880.5 (ν3), 1419.9 (ν10), 1323.2 (ν5), 836.6 (ν7), and 468.1 (ν8) cm-1 were observed. When CD3C(O)Cl was used, lines of CD3CO at 2246.2 (ν9), 2244.0 (ν1), 1866.1 (ν3), 1046.7 (ν5), 1029.7 (ν4), 1027.5 (ν10), 889.1 (ν6), and 723.8 (ν7) cm-1 appeared. Previous studies characterized only three vibrational modes of CH3CO and one mode of CD3CO in solid Ar. In contrast, upon photolysis of a CH3I/CO/p-H2 matrix with light at 248 nm and subsequent annealing at 5.1 K before re-cooling to 3.2 K, the CH3-CO complex was observed with characteristic IR features at 3165.7, 3164.5, 2150.1, 1397.6, 1396.4, and 613.0 cm-1. The assignments are based on photolytic behavior, observed deuterium isotopic shifts, and a comparison of observed vibrational wavenumbers and relative IR intensities with those predicted with quantum-chemical calculations. This work clearly indicates that CH3CO can be readily produced from photolysis of CH3C(O)Cl because of the diminished cage effect in solid p-H2 but not from the reaction of CH3 + CO because of the reaction barrier. Even though CH3 has nascent kinetic energy greater than 87 kJ mol-1 and internal energy ˜42 kJ mol-1 upon photodissociation of CH3I at 248 nm, its energy was rapidly quenched so that it was unable to overcome the barrier height of ˜27 kJ mol-1 for the formation of CH3CO from the CH3 + CO reaction; a barrierless channel for formation of a CH3-CO complex was observed instead. This rapid quenching poses a limitation in production of free radicals via bimolecular reactions in p-H2.

  3. KEMOD: A mixed chemical kinetic and equilibrium model of aqueous and solid phase geochemical reactions

    International Nuclear Information System (INIS)

    Yeh, G.T.; Iskra, G.A.

    1995-01-01

    This report presents the development of a mixed chemical Kinetic and Equilibrium MODel in which every chemical species can be treated either as a equilibrium-controlled or as a kinetically controlled reaction. The reaction processes include aqueous complexation, adsorption/desorption, ion exchange, precipitation/dissolution, oxidation/reduction, and acid/base reactions. Further development and modification of KEMOD can be made in: (1) inclusion of species switching solution algorithms, (2) incorporation of the effect of temperature and pressure on equilibrium and rate constants, and (3) extension to high ionic strength

  4. Radiation-induced reactions in D, L-α-alanine adsorbed in solid surfaces

    International Nuclear Information System (INIS)

    Aguilar, E; Negrón-Mendoza, A.; Camargo, C.

    2013-01-01

    The aim of this work is to study the behavior under irradiation of D, L and D-L α-alanine adsorbed in solid surfaces, as possible phase in the chemical evolution that may have occurred on the primitive Earth or in extraterrestrial environments and to evaluate the contribution of solids (a clay mineral) as shields for the adsorbed amino acids against a external energy source. The results show that α-alanine is adsorbed in the surfaces as function of pH and its yield of decomposition in mineral suspension is lower than the system without the solid surface. These results show the importance of nuclear techniques in these types of studies. (author)

  5. Deactivation of solid catalysts in liquid media: the case of leaching of active sites in biomass conversion reactions

    DEFF Research Database (Denmark)

    Sádaba, Irantzu; Lopez Granados, Manuel; Riisager, Anders

    2015-01-01

    This review is aimed to be a brief tutorial covering the deactivation of solid catalysts in the liquid phase, with specific focus on leaching, which can be especially helpful to researchers not familiarized with catalytic processes in the liquid phase. Leaching refers to the loss of active species....... However, as a consequence of the development of new processes for biorefineries, an increasing number of reactions deal with liquid media, and thus, the stability and reusability of a solid catalyst in this situation represent a huge challenge that requires specific attention. Leaching of active phases...... is particularly problematic because of its irreversibility and it can be one of the main causes of catalyst deactivation in liquid media, threatening the sustainability of the process. This tutorial review presents a survey of the main aspects concerning the deactivation due to leaching of active species from...

  6. Process and device for energy production from thermonuclear fusion reactions

    International Nuclear Information System (INIS)

    Bussard, R.W.; Coppi, Bruno.

    1977-01-01

    An energy generating system is described using a fusion reaction. It includes several contrivances for confining a plasma in an area, a protective device around a significant part of each of these confinement contrivances, an appliance for introducing a fusion reaction fuel in each of the confinements so that the plasma may be formed. Each confinement can be separated from the protective device so that it may be replaced by another. The system is connected to the confinements, to the protective devices or to both. It enables the thermal energy to be extracted and transformed into another form, electric, mechanical or both [fr

  7. Production of nanocrystalline metal powders via combustion reaction synthesis

    Science.gov (United States)

    Frye, John G.; Weil, Kenneth Scott; Lavender, Curt A.; Kim, Jin Yong

    2017-10-31

    Nanocrystalline metal powders comprising tungsten, molybdenum, rhenium and/or niobium can be synthesized using a combustion reaction. Methods for synthesizing the nanocrystalline metal powders are characterized by forming a combustion synthesis solution by dissolving in water an oxidizer, a fuel, and a base-soluble, ammonium precursor of tungsten, molybdenum, rhenium, or niobium in amounts that yield a stoichiometric burn when combusted. The combustion synthesis solution is then heated to a temperature sufficient to substantially remove water and to initiate a self-sustaining combustion reaction. The resulting powder can be subsequently reduced to metal form by heating in a reducing gas environment.

  8. Thermally activated reaction–diffusion-controlled chemical bulk reactions of gases and solids

    Directory of Open Access Journals (Sweden)

    S. Möller

    2015-01-01

    Full Text Available The chemical kinetics of the reaction of thin films with reactive gases is investigated. The removal of thin films using thermally activated solid–gas to gas reactions is a method to in-situ control deposition inventory in vacuum and plasma vessels. Significant scatter of experimental deposit removal rates at apparently similar conditions was observed in the past, highlighting the need for understanding the underlying processes. A model based on the presence of reactive gas in the films bulk and chemical kinetics is presented. The model describes the diffusion of reactive gas into the film and its chemical interaction with film constituents in the bulk using a stationary reaction–diffusion equation. This yields the reactive gas concentration and reaction rates. Diffusion and reaction rate limitations are depicted in parameter studies. Comparison with literature data on tokamak co-deposit removal results in good agreement of removal rates as a function of pressure, film thickness and temperature.

  9. Liquid and Solid Meal Replacement Products Differentially Affect Postprandial Appetite and Food Intake in Older Adults

    Science.gov (United States)

    Stull, April J.; Apolzan, John W.; Thalacker-Mercer, Anna E.; Iglay, Heidi B.; Campbell, Wayne W.

    2008-01-01

    Liquid and solid foods are documented to elicit differential appetitive and food intake responses. This study was designed to assess the influences of liquid vs solid meal replacement products on postprandial appetite ratings and subsequent food intake in healthy older adults. This study used a randomized and crossover design with two 1-day trials (1 week between trials), and 24 adults (12 men and 12 women) aged 50 to 80 years with body mass index (calculated as kg/m2) between 22 and 30 participated. After an overnight fast, the subjects consumed meal replacement products as either a beverage (liquid) or a bar (solid). The meal replacement products provided 25% of each subject's daily estimated energy needs with comparable macro-nutrient compositions. Subjects rated their appetite on a 100 mm quasilogarithmic visual analog scale before and 15, 30, 45, 60, 90, 120, and 150 minutes after consuming the meal replacement product. At minute 120, each subject consumed cooked oatmeal ad libitum to a “comfortable level of fullness.” Postprandial composite (area under the curve from minute 15 to minute 120) hunger was higher (P=0.04) for the liquid vs solid meal replacement products and desire to eat (P=0.15), preoccupation with thoughts of food (P=0.07), and fullness (P=0.25) did not differ for the liquid vs solid meal replacement products. On average, the subjects consumed 13.4% more oatmeal after the liquid vs solid (P=0.006) meal replacement product. These results indicate that meal replacement products in liquid and solid form do not elicit comparable appetitive and ingestive behavior responses and that meal replacement products in liquid form blunt the postprandial decline in hunger and increase subsequent food intake in older adults. PMID:18589034

  10. High-pressure synthesis of rhombohedral α-AgGaO{sub 2} via direct solid state reaction

    Energy Technology Data Exchange (ETDEWEB)

    Akhtar, Meysam [Department of Physics and Astronomy, University of Louisville, 102 Natural Science Building, Louisville, KY 40292 (United States); Menon, Madhu [Center for Computational Sciences, University of Kentucky, 325 McVey Hall, Lexington, KY 40506 (United States); Sunkara, Mahendra [Conn Center for Renewable Energy Research, University of Louisville, Ernst Hall Room 102A, Louisville, KY 40292 (United States); Sumanasekera, Gamini [Department of Physics and Astronomy, University of Louisville, 102 Natural Science Building, Louisville, KY 40292 (United States); Conn Center for Renewable Energy Research, University of Louisville, Ernst Hall Room 102A, Louisville, KY 40292 (United States); Durygin, Andriy [Center for the Study of Matter at Extreme Conditions, Florida International University, VH 140, University Park, Miami, FL 33199 (United States); Jasinski, Jacek B., E-mail: jacek.jasinski@louisville.edu [Conn Center for Renewable Energy Research, University of Louisville, Ernst Hall Room 102A, Louisville, KY 40292 (United States)

    2015-08-25

    Highlights: • Direct synthesis of α-AgGaO{sub 2} via a solid state reaction of Ag{sub 2}O and Ga{sub 2}O{sub 3} powders. • Utilizing high pressure diamond anvil cell to facilitate solid state reaction. • Experimental and theoretical study of vibrational modes for α-AgGaO{sub 2}. • Extensive characterization of synthesized α-AgGaO{sub 2} samples. • GGA + U formalism-based DFT calculations of electronic structure and band gap in α-AgGaO{sub 2}. - Abstract: In this work, we demonstrate the application of high pressure conditions to enable the direct synthesis of α-AgGaO{sub 2} via a solid state reaction of Ag{sub 2}O and Ga{sub 2}O{sub 3}. Synthesis experiments were carried out at pressures and temperatures up to ∼10 GPa and ∼600 °C, respectively, using a resistively-heated diamond anvil cell. Thus synthesized α-AgGaO{sub 2} samples were characterized and their chemical composition and crystal structure were confirmed. In particular, electron diffraction confirmed the rhombohedral delafossite crystal structure of the synthesized AgGaO{sub 2} and its corresponding lattice parameters of a = 2.99 Å and c = 18.43 Å. The vibrational modes analysis was also conducted using a combination of ab initio density functional theory (DFT) and Raman spectroscopy. This analysis yielded good agreement between the calculated Raman-active modes and experimental Raman data. Finally, the application of the GGA + U formalism-based on DFT to calculate the electronic band structure of α-AgGaO{sub 2} provided a more realistic theoretical band gap value than those reported previously.

  11. Bio-charcoal production from municipal organic solid wastes

    Science.gov (United States)

    AlKhayat, Z. Q.

    2017-08-01

    The economic and environmental problems of handling the increasingly huge amounts of urban and/or suburban organic municipal solid wastes MSW, from collection to end disposal, in addition to the big fluctuations in power supply and other energy form costs for the various civilian needs, is studied for Baghdad city, the ancient and glamorous capital of Iraq, and a simple control device is suggested, built and tested by carbonizing these dried organic wastes in simple environment friendly bio-reactor in order to produce low pollution potential, economical and local charcoal capsules that might be useful for heating, cooking and other municipal uses. That is in addition to the solve of solid wastes management problem which involves huge human and financial resources and causes many lethal health and environmental problems. Leftovers of different social level residential campuses were collected, classified for organic materials then dried in order to be supplied into the bio-reactor, in which it is burnt and then mixed with small amounts of sugar sucrose that is extracted from Iraqi planted sugar cane, to produce well shaped charcoal capsules. The burning process is smoke free as the closed burner’s exhaust pipe is buried 1m underground hole, in order to use the subsurface soil as natural gas filter. This process has proved an excellent performance of handling about 120kg/day of classified MSW, producing about 80-100 kg of charcoal capsules, by the use of 200 l reactor volume.

  12. Densification of Ce0.9Gd0.1O1.95 barrier layer by in-situ solid state reaction

    DEFF Research Database (Denmark)

    Ni, De Wei; Esposito, Vincenzo

    2014-01-01

    A novel methodology, called in-situ solid state reaction (SSR), is developed and achieved for the densification of gadolinia doped ceria (CGO) barrier layer (BL) within the solid oxide fuel cell (SOFC) technology. The method is based on the combined use of impregnation technique and a designed two...

  13. Synthesis of CaTiO3:Pr persistent phosphors by a modified solid-state reaction

    International Nuclear Information System (INIS)

    Yin Shengyu; Chen Donghua; Tang Wanjun; Peng Yuhua

    2007-01-01

    Using tetra-n-butyl titanate and calcium nitrate as raw materials, the praseodymium-doped calcium titanates have been synthesized via a modified solid-state reaction. The decomposition process of the precursor, crystallization, and particle sizes of CaTiO 3 :Pr have been investigated by using thermal analysis, powder X-ray diffraction and transmission electron microscopy (TEM). TG-DTG curves and X-ray diffraction analysis indicate that crystalline calcium titanate has been synthesized at calcining temperature of 600 deg. C for 2 h. Photoluminescence and decay curves show that the sample obtained at the sintering temperature of 900 deg. C exhibited the optimal luminous property

  14. In situ57Fe Moessbauer Investigation of Solid-State Redox Reactions of Lithium Insertion Electrodes for Advanced Batteries

    International Nuclear Information System (INIS)

    Sakai, Yoichi; Ariyoshi, Kingo; Ohzuku, Tsutomu

    2002-01-01

    A novel in situ electrochemical cell for 57 Fe Moessbauer measurements was developed in order to clarify the mechanisms of solid-state redox reactions in lithium insertion materials containing iron. Our in situ Moessbauer technique was successfully applied to the determination as to which transition metal ion was a redox center in the insertion electrodes, such as LiFe 0.5 Mn 1.5 O 4 , LiFeTiO 4 , or LiFe 0.25 Ni 0.75 O 2 , for the lithium-ion batteries.

  15. Two-pion production in photon-induced reactions

    Indian Academy of Sciences (India)

    photoproduction from nuclei is also used to investigate the in-medium modification of meson–meson interactions. ... the observation of an in-medium modification of the vector meson masses can pro- vide a unique .... similar behavior is found in (γ,π+π0) reactions, shown in the right panel of figure 3. Additionally, the peak in ...

  16. Determination of 68Ga production parameters by different reactions ...

    Indian Academy of Sciences (India)

    Gallium-68 (1/2 = 68 min, + = 89%) is an important positron-emitting radionuclide for positron emission tomography and used in nuclear medicine for diagnosing tumours. This study gives a suitable reaction to produce 68Ga. Gallium-68 excitation function via 68Zn(, ) 68Ga, 68Zn(, 2) 68Ga, 70Zn(, 3) 68Ga and ...

  17. Protonation Reaction of Benzonitrile Radical Anion and Absorption of Product

    DEFF Research Database (Denmark)

    Holcman, Jerzy; Sehested, Knud

    1975-01-01

    The rate constant for the protonation of benzonitrile radical anions formed in pulse radiolysis of aqueous benzonitrile solutions is (3.5 ± 0.5)× 1010 dm3 mol–1 s–1. A new 270 nm absorption band is attributed to the protonated benzonitrile anion. The pK of the protonation reaction is determined t...

  18. Structures of the particles of the condensed dispersed phase in solid fuel combustion products plasma

    International Nuclear Information System (INIS)

    Samaryan, A.A.; Chernyshev, A.V.; Nefedov, A.P.; Petrov, O.F.; Fortov, V.E.; Mikhailov, Yu.M.; Mintsev, V.B.

    2000-01-01

    The results of experimental investigations of a type of dusty plasma which has been least studied--the plasma of solid fuel combustion products--were presented. Experiments to determine the parameters of the plasma of the combustion products of synthetic solid fuels with various compositions together with simultaneous diagnostics of the degree of ordering of the structures of the particles of the dispersed condensed phase were performed. The measurements showed that the charge composition of the plasma of the solid fuels combustion products depends strongly on the easily ionized alkali-metal impurities which are always present in synthetic fuel in one or another amount. An ordered arrangement of the particles of a condensed dispersed phase in structures that form in a boundary region between the high-temperature and condensation zones was observed for samples of aluminum-coated solid fuels with a low content of alkali-metal impurities

  19. Solid-state reactions during mechanical milling of Fe-Al under nitrogen atmosphere

    Czech Academy of Sciences Publication Activity Database

    Jirásková, Yvonna; Buršík, Jiří; Čížek, J.; Jančík, D.

    2013-01-01

    Roč. 568, AUG (2013), s. 106-111 ISSN 0925-8388 R&D Projects: GA ČR(CZ) GAP108/11/1350 Institutional support: RVO:68081723 Keywords : milling * mechanical alloying * Mössbauer phase analysis * Fe-Al alloy * microstructure Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.726, year: 2013

  20. Determination of the percentage of quitine desacetilation reaction by solid state carbon-13 NMR

    International Nuclear Information System (INIS)

    Ferracin, Ricardo J.; Cass, Quezia B.; Bassi, Ana L.

    1997-01-01

    Quitine is a bi-polymer largely found in invertebrates. As most compounds of this class are insoluble in common organic solvents, the des-acetylation percentile was obtained by carbon-13 solid state nuclear magnetic resonance. The methodology is presented. Results are presented

  1. In Situ Insight into Reversible O2 Gas-Solid Reactions

    DEFF Research Database (Denmark)

    Wegeberg, Christina

    2016-01-01

    Non-porous crystalline solids containing a series of cationic tetracobalt complexes reversibly, selectively and stoichiometrically chemisorb dioxygen in temperature/O2 partial pressure induced processes involving the oxidation of cobalt with concurrent reduction of two equivalents of sorbed O2 to...

  2. Production of proteases from organic wastes by solid-state fermentation: downstream and zero waste strategies.

    Science.gov (United States)

    Marín, Maria; Artola, Adriana; Sánchez, Antoni

    2018-04-01

    Production of enzymes through solid-state fermentation (SSF) of agro-industrial wastes reports high productivity with low investment. The extraction of the final product from the solid waste and solid disposal represent the main cost of the process. In this work, the complete downstream processes of SSF of two industrial residues for the production of proteases, soy fibre (SF) and a mixture of hair and sludge (HS), were studied in terms of activity recovery, using different extraction parameters (extracting solvent, ratio solid: solvent and extraction mode). Activity after lyophilisation was tested. Solid waste valorisation after extraction was studied using respiration techniques and biogas production tests, as part of a zero waste strategy. Results showed a maximum extraction yield of 91% for SF and 121% for HS, both in agitated mode and distilled water as extraction agent. An average activity recovery of 95 ± 6 and 94 ± 6% for SF and HS, respectively, was obtained after lyophilisation and redissolution. To reduce the cost of extraction, a ratio 1:3 w : v solid-solvent in static mode is advised for SF, and 1:2 w : v extraction ratio in agitated mode for HS, both with distilled water as extracting agent. Both composting and anaerobic digestion are suitable techniques for valorisation of the waste material.

  3. Oxidation kinetics of reaction products formed in uranium metal corrosion

    International Nuclear Information System (INIS)

    Totemeier, T. C.

    1998-01-01

    The oxidation behavior of uranium metal ZPPR fuel corrosion products in environments of Ar-4%O 2 and Ar-20%O 2 were studied using thermo-gravimetric analysis (TGA). These tests were performed to extend earlier work in this area specifically, to assess plate-to-plate variations in corrosion product properties and the effect of oxygen concentration on oxidation behavior. The corrosion products from two relatively severely corroded plates were similar, while the products from a relatively intact plate were not reactive. Oxygen concentration strongly affected the burning rate of reactive products, but had little effect on low-temperature oxidation rates

  4. Oxidation kinetics of reaction products formed in uranium metal corrosion.

    Energy Technology Data Exchange (ETDEWEB)

    Totemeier, T. C.

    1998-04-22

    The oxidation behavior of uranium metal ZPPR fuel corrosion products in environments of Ar-4%O{sub 2} and Ar-20%O{sub 2} were studied using thermo-gravimetric analysis (TGA). These tests were performed to extend earlier work in this area specifically, to assess plate-to-plate variations in corrosion product properties and the effect of oxygen concentration on oxidation behavior. The corrosion products from two relatively severely corroded plates were similar, while the products from a relatively intact plate were not reactive. Oxygen concentration strongly affected the burning rate of reactive products, but had little effect on low-temperature oxidation rates.

  5. 29Si solid state NMR investigation of pozzolanic reaction occurring in lime-treated Ca-bentonite

    International Nuclear Information System (INIS)

    Pomakhina, Elena; Deneele, Dimitri; Gaillot, Anne-Claire; Paris, Michael; Ouvrard, Guy

    2012-01-01

    Lime is widely used as additive to improve the mechanical properties of natural soil used in earthworks. However, the physico-chemical mechanisms involved are yet not well understood. In order to develop and optimize this treatment method, a better understanding of the interaction between lime and the minerals of the soils, in particular clay minerals, is required. In this study, Ca-bentonite was treated with 2, 5 and 10 wt.% of lime during 1 to 98 days. Modifications in the Si local environment were then monitored by solid state nuclear magnetic resonance to investigate the pozzolanic reaction. All the soil mineral phases contribute to the release of Si and to the pozzolanic reaction, with a rapid and total consumption of Si-polymorph and an exacerbated dissolution of montmorillonite. Mechanism of C–S–H formation, function of the Ca content in the system, was found to match the sorosilicate-tobermorite model described in cement systems.

  6. The operation of a single-sided linear induction motor with squirrel-cage and solid-steel reaction rails

    Science.gov (United States)

    Eastham, A. R.; Katz, R. M.

    1980-09-01

    Two test programs have been conducted to evaluate the performance of a single-sided linear induction motor with a squirrel-cage reaction rail and with a solid steel reaction rail. A 1.73-m-long six-pole stator interacted with the rails mounted on the rim of a 7.6-m-diam wheel. A 64-channel data acquisition system allowed tests to be performed over a wide range of operating conditions at speeds up to 20 m/sec. Typical test results which compare and contrast the mechanical, electrical and magnetic behavior of the SLIMs are presented. The test data are being used to assess the SLIM as an integrated suspension/propulsion system and for other transportation applications.

  7. A compact Ultra High Vacuum (UHV) compatible instrument for time of flight energy measurements of slow heavy reaction products

    International Nuclear Information System (INIS)

    Kuznetsov, A.V.; Loveland, W.; Jakobsson, B.; Whitlow, H.J.; Bouanani, M. El; Univ. of North Texas, Denton, TX

    2000-01-01

    A compact Ultra High Vacuum (UHV) compatible instrument for time of flight energy measurements of slow heavy reaction products from nuclear reactions has been designed and tested at the CELSIUS storage ring in Uppsala. The construction is based on MicroChannel Plate time detectors of the electron mirror type and silicon p-i-n diodes, and permits the detectors to be stacked side-by-side to achieve large solid angle coverage. This kind of telescope measures the Time of Flight (ToF) and Energy (E) of the particle from which one can reconstruct mass. The combination of an ultra-thin cluster gas-jet target and thin carbon emitter foils allows one to measure heavy residues down to an energy of ∼ 35 keV/nucleon from the interactions of 400 MeV/nucleon 16 O with nat Xe gas targets

  8. A compact Ultra High Vacuum (UHV) compatible instrument for time of flight energy measurements of slow heavy reaction products

    Energy Technology Data Exchange (ETDEWEB)

    Kuznetsov, A.V. [V.G.Khlopin Radium Institute, St. Petersburg (Russian Federation); Uppsala Univ. (Sweden). The Svedberg Lab.; Veldhuizen, E.J. van; Aleklett, K. [Uppsala Univ., (Sweden). Dept. of Radiation Sciences; Westerberg, L. [Uppsala University (Sweden). The Svedberg Lab.; Lyapin, V.G. [V.G.Khlopin Radium Institute, St. Petersburg (Russian Federation); Loveland, W. [Oregon State Univ., Corvallis, OR (United States). Dept. of Chemistry; Bondorf, J. [Niels Bohr Inst., Copenhagen (Denmark); Jakobsson, B. [Lund Univ. (Sweden). Dept. of Physics; Whitlow, H.J. [Lund Univ. (Sweden). Dept. of Nuclear Physics; Bouanani, M. El [Lund Univ. (Sweden). Dept. of Nuclear Physics; Univ. of North Texas, Denton, TX (United States). Dept. of Physics

    2000-07-01

    A compact Ultra High Vacuum (UHV) compatible instrument for time of flight energy measurements of slow heavy reaction products from nuclear reactions has been designed and tested at the CELSIUS storage ring in Uppsala. The construction is based on MicroChannel Plate time detectors of the electron mirror type and silicon p-i-n diodes, and permits the detectors to be stacked side-by-side to achieve large solid angle coverage. This kind of telescope measures the Time of Flight (ToF) and Energy (E) of the particle from which one can reconstruct mass. The combination of an ultra-thin cluster gas-jet target and thin carbon emitter foils allows one to measure heavy residues down to an energy of {approx} 35 keV/nucleon from the interactions of 400 MeV/nucleon {sup 16}O with {sup nat} Xe gas targets.

  9. Hydrogen production via thermochemical water-splitting by lithium redox reaction

    International Nuclear Information System (INIS)

    Nakamura, Naoya; Miyaoka, Hiroki; Ichikawa, Takayuki; Kojima, Yoshitsugu

    2013-01-01

    Highlights: •Hydrogen production via water-splitting by lithium redox reactions possibly proceeds below 800 °C. •Entropy control by using nonequilibrium technique successfully reduces the reaction temperature. •The operating temperature should be further reduced by optimizing the nonequilibrium condition to control the cycle. -- Abstracts: Hydrogen production via thermochemical water-splitting by lithium redox reactions was investigated as energy conversion technique. The reaction system consists of three reactions, which are hydrogen generation by the reaction of lithium and lithium hydroxide, metal separation by thermolysis of lithium oxide, and oxygen generation by hydrolysis of lithium peroxide. The hydrogen generation reaction completed at 500 °C. The metal separation reaction is thermodynamically difficult because it requires about 3400 °C in equilibrium condition. However, it was indicated from experimental results that the reaction temperature was drastically reduced to 800 °C by using nonequilibrium technique. The hydrolysis reaction was exothermic reaction, and completed by heating up to 300 °C. Therefore, it was expected that the water-splitting by lithium redox reactions was possibly operated below 800 °C under nonequilibrium condition

  10. Evaluation of conidia production and mycelial growth in solid culture ...

    African Journals Online (AJOL)

    FATIMAYALBERTO

    2012-10-02

    Oct 2, 2012 ... liquid culture media of different species of ..... Jackson MA, McGuire MR, Lacey LA, Wraight SP (1997). Liquid culture ... fermentation and the substrate in the production of Trichoderma ... Conidiation induction in Penicillium.

  11. Hydrolysis of proteinaceous tannery solid waste for the production of ...

    African Journals Online (AJOL)

    user

    2012-07-12

    Jul 12, 2012 ... microbial system. ... second-order mathematical model using the equation: .... experimental and predicted values of protease production by Selenomonas ruminantium. ..... The purified protease was found to be resistant to.

  12. Synthesis of high-purity Li{sub 8}ZrO{sub 6} powder by solid state reaction under hydrogen atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Shin-mura, Kiyoto; Otani, Yu; Ogawa, Seiya [Course of Mechanical Engineering, Graduate School of Engineering, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292 (Japan); Niwa, Eiki; Hashimoto, Takuya [Department of Physics, College of Humanities and Sciences, Nihon University, 3-8-1 Sakurajousui, Setagaya-ku, Tokyo 156-8550 (Japan); Hoshino, Tsuyoshi [Breeding Functional Materials Development Group, Department of Blanket Systems Research, Rokkasho Fusion Institute, Sector of Fusion Research and Development, Japan Atomic Energy Agency, 2-166 Obuchi, Omotedate, Rokkasho-mura, Kamikita-gun, Aomori 039-3212 (Japan); Sasaki, Kazuya, E-mail: k_sasaki@tokai-u.ac.jp [Course of Mechanical Engineering, Graduate School of Engineering, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292 (Japan); Department of Prime Mover Engineering, School of Engineering, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292 (Japan)

    2016-11-01

    Highlights: • A fine pure Li{sub 8}ZrO{sub 6} powder was synthesized by using Li{sub 2}CO{sub 3} and ZrO{sub 2} via a solid state reaction. • Influences on the purity of product powder, lattice defect, and crystal orientation were revealed. • The suitable synthesis conditions of the fine and high purity Li{sub 8}ZrO{sub 6} powder were found. • The reaction process of the synthesis of Li{sub 8}ZrO{sub 6} was estimated. - Abstract: Li{sub 8}ZrO{sub 6} contains a large amount of Li and has a significant potential as a tritium breeder. However, few syntheses of fine-grain, high-purity Li{sub 8}ZrO{sub 6} powder have been reported. In this study, a high-purity powder of Li{sub 8}ZrO{sub 6} was synthesized by solid state reaction under hydrogen atmosphere combined with an effective lithium source and a suitable initial Li:Zr molar ratio. Mixed powders of Li{sub 2}CO{sub 3} and ZrO{sub 2} were fired at around 630 °C in H{sub 2} for several hours and several firing cycles. The low firing temperature inhibited the vaporization of Li during the heating, so that excessive amounts of Li were not needed for the synthesis, and the Li:Zr ratio in the starting material was 10:1 (mol:mol). In this synthesis, Li{sub 2}O was generated via the decomposition of Li{sub 2}CO{sub 3} during firing in H{sub 2}, and reacted with ZrO{sub 2} to form Li{sub 6}Zr{sub 2}O{sub 7}, which reacted with itself to form Li{sub 8}ZrO{sub 6}.

  13. Utility of spectral measurements of secondary reaction products

    International Nuclear Information System (INIS)

    Heidbrink, W.E.

    1986-02-01

    The spectra of 15 MeV protons and 14 MeV neutrons produced in the burnup of 0.8 MeV 3 He ions and 1 MeV tritons through the d( 3 He,p)α and d(t,n)α fusion reactions contain information on the velocity distributions of the energetic 3 He ions and tritons. 11 refs., 2 figs

  14. CONTINUOUS AND SEMICONTINUOUS REACTION SYSTEMS FOR HIGH-SOLIDS ENZYMATIC HYDROLYSIS OF LIGNOCELLULOSICS

    Directory of Open Access Journals (Sweden)

    A. González Quiroga

    2015-12-01

    Full Text Available Abstract An attractive operation strategy for the enzymatic hydrolysis of lignocellulosics results from dividing the process into three stages with complementary goals: continuous enzyme adsorption at low-solids loading (5% w/w with recycling of the liquid phase; continuous liquefaction at high-solids content (up to 20% w/w; and, finally, continuous or semicontinuous hydrolysis with supplementation of fresh enzymes. This paper presents a detailed modeling and simulation framework for the aforementioned operation strategies. The limiting micromixing situations of macrofluid and microfluid are used to predict conversions. The adsorption and liquefaction stages are modeled as a continuous stirred tank and a plug flow reactor, respectively. Two alternatives for the third stage are studied: a train of five cascading stirred tanks and a battery of batch reactors in parallel. Simulation results show that glucose concentrations greater than 100 g L-1 could be reached with both of the alternatives for the third stage.

  15. Origin of Nanobubbles Electrochemically Formed in a Magnetic Field: Ionic Vacancy Production in Electrode Reaction

    Science.gov (United States)

    Aogaki, Ryoichi; Sugiyama, Atsushi; Miura, Makoto; Oshikiri, Yoshinobu; Miura, Miki; Morimoto, Ryoichi; Takagi, Satoshi; Mogi, Iwao; Yamauchi, Yusuke

    2016-07-01

    As a process complementing conventional electrode reactions, ionic vacancy production in electrode reaction was theoretically examined; whether reaction is anodic or cathodic, based on the momentum conservation by Newton’s second law of motion, electron transfer necessarily leads to the emission of original embryo vacancies, and dielectric polarization endows to them the same electric charge as trans- ferred in the reaction. Then, the emitted embryo vacancies immediately receive the thermal relaxation of solution particles to develop steady-state vacancies. After the vacancy production, nanobubbles are created by the collision of the vacancies in a vertical magnetic field.

  16. Analysis of a Buchwald-Hartwig amination: reaction for pharmaceutical production

    DEFF Research Database (Denmark)

    Christensen, Henrik

    The Buchwald-Hartwig amination reaction is widely used in the production of N-arylated amines in the pharmaceutical industry. The reaction is betweenan aryl halogen and a primary or secondary amine in the presence of a base and a homogeneous catalyst giving the desired N-arylated amine. Due to mild...... is to increase the understanding of the chem­ical reaction mechanisms and kinetics for the Buchwald-Hartwig amination reaction. Also, to develop methods for application of these mechanisms and kinetics to optimize and scale up an organic synthesis to an industrial phar­maceutical production. The Buchwald...

  17. Analysis of a Buckwald-Hartwig amination: reaction for pharmaceutical production

    DEFF Research Database (Denmark)

    Christensen, Henrik; Kiil, Søren; Dam-Johansen, Kim

    The Buchwald-Hartwig amination reaction is widely used in the production of N-arylated amines in the pharmaceutical industry. The reaction is betweenan aryl halogen and a primary or secondary amine in the presence of a base and a homogeneous catalyst giving the desired N-arylated amine. Due to mild...... is to increase the understanding of the chem­ical reaction mechanisms and kinetics for the Buchwald-Hartwig amination reaction. Also, to develop methods for application of these mechanisms and kinetics to optimize and scale up an organic synthesis to an industrial phar­maceutical production. The Buchwald...

  18. Stoichiometric control in Bi4Ti3O12 synthesis by novel hybrid solid state reaction

    DEFF Research Database (Denmark)

    Gadea, C.; Phatharapeetranun, N.; Ksapabutr, B.

    2018-01-01

    The synthesis of bismuth titanate Bi4Ti3O12 (BiT) is performed via a novel solid state reaction. The reaction is designed to control the stoichiometric content of the highly volatile element, i.e. Bi. The chemical route consists in trapping bismuth oxide colloids in a stabilized titanium based sol...

  19. Effect of reverse Boudouard reaction catalyst on the performance of solid oxide carbon fuel cells integrated with a dry gasifier

    International Nuclear Information System (INIS)

    Kim, Sun-Kyung; Mehran, Muhammad Taqi; Mushtaq, Usman; Lim, Tak-Hyoung; Lee, Jong-Won; Lee, Seung-Bok; Park, Seok-Joo; Song, Rak-Hyun

    2016-01-01

    Highlights: • The addition of K_2CO_3 catalyst in carbon fuel improves the performance of SO-CFC. • Thermal and electrochemical analyses done to elucidate the catalytic enhancement. • Material characterization of SO-CFC performed after long-term degradation test. - Abstract: A solid oxide carbon fuel cell (SO-CFC) integrated with a dry gasifier was operated on activated carbon fuel and the effect of adding a reverse Boudouard gasification catalyst on the performance and long-term operation characteristics of the SO-CFC was investigated. The reactivity of the carbon fuels for the Boudouard gasification reaction was analyzed by a thermal analysis at various operating conditions. The SO-CFC was then operated on gasified fuel gas consisting of CO_2 and CO obtained from the integrated dry gasifier. The SO-CFC operated on activated carbon fuel with 5 wt.% K_2CO_3 achieved a maximum power density of 202, 262, and 271 mW/cm"2 at 750, 800, and 850 °C, respectively; the SO-CFC fueled with activated carbon fuel without a catalyst meanwhile yielded maximum power density of 168 mW/cm"2 at 850 °C. By using electrochemical impedance spectroscopy, the effect of adding the catalyst on the gasification products and subsequently on the performance of the SO-CFC was studied. A long-term degradation test was conducted by continuously operating the SO-CFC at 50 mA/cm"2 for 518 h at 750 °C. During the long-term degradation test, the average degradation rate of the SO-CFC was found to be 183 mV/kh. The post-mortem SEM and XRD analyses of the SO-CFC after the long-term test revealed the presence of carbon deposits and oxidation of Ni at the anode, causing a relatively higher degree of degradation in the SO-CFC integrated with the dry gasifier during the long-term operation. The addition of the K_2CO_3 based dry gasification catalyst significantly enhances the performance of the SO-CFC integrated with dry gasification, but during long-term operation, the degradation rate is found

  20. A new chemical route to a hybrid nanostructure: room-temperature solid-state reaction synthesis of Ag@AgCl with efficient photocatalysis.

    Science.gov (United States)

    Hu, Pengfei; Cao, Yali

    2012-08-07

    The room-temperature solid-state chemical reaction technique has been used to synthesize the silver nanoparticle-loaded semiconductor silver@silver chloride for the first time. It has the advantages of convenient operation, lower cost, less pollution, and mass production. This simple technique created a wide array of nanosized silver particles which had a strong surface plasmon resonance effect in the visible region, and built up an excellent composite structure of silver@silver chloride hybrid which exhibited high photocatalytic activity and stability towards decomposition of organic methyl orange under visible-light illumination. Moreover, this work achieved the control of composition of the silver@silver chloride composite simply by adjusting the feed ratio of reactants. It offers an alternative method for synthesising metal@semiconductor composites.

  1. Solid-state reaction in Ti/Ni multilayered films studied by using magneto-optical spectroscopy

    CERN Document Server

    Lee, Y P; Kim, K W; Kim, C G; Kudryavtsev, Y V; Nemoshkalenko, V V; Szymanski, B

    2000-01-01

    A comparative study of the solid-state reaction (SSR) in a series of Ti/Ni multilayered films (MLDs) with bilayer periods of 0.65-22.2 nm and a constant Ti to Ni sublayer thickness ratio was performed by using experimental and computer-simulated magneto-optical (MO) spectroscopy based on different models of MLFs, as well as x-ray diffraction (XRD). The spectral and sublayer thickness dependences of the MO properties of the Ti/Ni MLFs were explained on the basis of the electromagnetic theory. The existence of a threshold nominal Ni-sublayer thickness of about 3 nm for the as-deposited Ti/Ni MLF to observe of the equatorial Kerr effect was explained by a solid-state reaction which formed nonmagnetic alloyed regions between pure components during the MLF deposition. The SSR in the Ti/Ni MLFs, which was caused by the low temperature annealing, led to the formation of an amorphous Ti-Ni alloy and took place mainly in the Ti/Ni MLFs with ''thick'' sublayers. For the caes of Ti/Ni MLFs, the MO approach turned out to...

  2. Volatilization and reaction of fission products in flowing steam

    International Nuclear Information System (INIS)

    Johnson, I.; Steidl, D.V.; Johnson, C.E.

    1985-01-01

    The principal risk to the public from nuclear power plants derives from the highly radioactive atoms (fission products) generated as energy is produced in the nuclear fuel. The revolatilization of fission products from reactor system surfaces due to self-heating by radioactive decay has become a complicating factor in the source-term redefinition effort. It has had a major impact on calculations of fission product distributions in accident safety analyses. The focus of this research effort was to investigate the volatilization and transport of fission products and control rod materials in a flowing gaseous steam-hydrogen mixture. Fission product and control rod materials in various combinations were studied including CsI, CsOH, TeO 2 , SrO, Ag, In, Cd and Mn. The vaporization behavior of the deposits were characterized with respect to vaporization rates, chemical species and downstream transport behavior

  3. Biological diversity of photosynthetic reaction centers and the solid-state photo-CIDNP effect

    NARCIS (Netherlands)

    Roy, Esha

    2007-01-01

    Photosynthetic reaction centers (RCs) from plants, heliobacteria and green sulphur bacteria has been investigated with photochemically induced dynamic nuclear polarization (photo-CIDNP) MAS NMR. In photosystem (PS) I of spinach, all signals appear negative which is proposed by a predominance of the

  4. Impeded solid state reactions and transformations in ceramic catalysts supports and catalysts

    Directory of Open Access Journals (Sweden)

    Ernő E. Kiss

    2012-12-01

    Full Text Available Impeded chemical reactions and impeded polymorphous transformation in materials are discussed, as desired effects, for stabilization of ceramic catalyst supports and ceramic based catalysts. This paper gives a short overview about the possibilities of slowing down the aging processes in ceramic catalyst supports and catalysts. Special attention is given to alumina and titania based catalysts.

  5. Sulfur Poisoning of the Water Gas Shift Reaction on Anode Supported Solid Oxide Fuel Cells

    DEFF Research Database (Denmark)

    Hagen, Anke

    2013-01-01

    resistance increased both in the high and low frequency region, which indicates a strong poisoning of the water gas shift reaction and thus a lack of hydrogen fuel in addition to the poisoning of the electrochemical hydrogen oxidation. All poisoning effects are reversible under the applied operating...

  6. Application of the aza-Diels-Alder reaction in the synthesis of natural products.

    Science.gov (United States)

    Cao, Min-Hui; Green, Nicholas J; Xu, Sheng-Zhen

    2017-04-11

    The Diels-Alder reaction that involves a nitrogen atom in the diene or dienophile is termed the aza-Diels-Alder reaction. As well as the powerful all-carbon Diels-Alder reaction, the aza-Diels-Alder reaction has also played an important role in the total synthesis of natural products. Herein, we review various natural products using an aza-Diels-Alder reaction as a key step to their total synthesis, and divide the syntheses into inter- and intra-molecular aza-Diels-Alder reactions and a retro-aza-Diels-Alder reaction. Inter- and intra-molecular aza-Diels-Alder reactions involve an imine as an electron deficient dienophile and an imine as an electron deficient azadiene. The significance of the aza-Diels-Alder reaction for the construction of a six-membered ring containing nitrogen is tremendous, but the development of asymmetric, in particular catalytic enantioselective intramolecular aza-Diels-Alder reaction in the total synthesis of natural products remains highly challenging, and will no doubt see enormous advances in the future.

  7. Defined media and inert supports : their potential as solid-state fermentation production systems

    NARCIS (Netherlands)

    Ooijkaas, L.P.; Weber, F.J.; Buitelaar, R.M.; Tramper, J.; Rinzema, A.

    2000-01-01

    Solid-state fermentation (SSF) using inert supports impregnated with chemically defined liquid media has several potential applications in both scientific studies and in the industrial production of high-value products, such as metabolites, biological control agents and enzymes. As a result of its

  8. COMPARATIVE EVALUTION OF CEPHALOSPORIN-C PRODUCTION IN SOLID STATE FERMENTATION AND SUBMERGED LIQUID CULTURE

    Directory of Open Access Journals (Sweden)

    Mahdi Rezazarandi

    2012-08-01

    Full Text Available The advantages of solid state fermentation (SSF utilization in producing enzymes & secondary metabolites have been shown, whereas, submerged liquid fermentation (SLF condition has the major usage in industrial production of antibiotics. As an antibiotic of B-lactams group, cephalosporin-C (CPC is indicated due to its wide effect and broad convention in treatment of infectious diseases. Regarding industrial production of CPC regularly done in SLF condition, we compared CPC production sum in SLF and SSF conditions. In this analysis, A. chrysogenum was employed, which was inoculated to SLF and SSF, while internal fermenter conditions were totally under control. After extraction of CPC, productions in two states of SLF and SSF were compared using the cylinder plate method. According to Antibiotic assay and production amount comparison, results expressed a ratio of development of production in SSF conditions to SLF conditions. Regarding previous studies on a solid state fermenter and its advantages, in this study, convenience of SSF conditions compared to SLF conditions was experimented. Also mentioning that maintaining the condition of solid state fermenter is more comfortable and practical than liquid state fermenter, using a solid based fermenter to produce antibiotics, especially CPC, can be appropriate. Considering appropriate control conditions of SSF to produce secondary metabolites, decrease in expenses, and increase of production, taking advantage of it in order to increase production parallel to modern methods, such as genetically manipulating CPC producing microorganisms are recommended to pharmacological industries. Also, to make this method applicable, further studies in industrial criterion seem necessary.

  9. Production of α-amylase by solid state fermentation by Rhizopus ...

    African Journals Online (AJOL)

    2015-02-18

    Feb 18, 2015 ... However, only a few strains of fungi and bacteria meet the criteria for production of ... amylase production, but solid-state fermentation (SSF) is emerging as a ..... synthesis of lactic acid in R. oryzae and Rhizopus arrhizus using ...

  10. GRANULATION AND BRIQUETTING OF SOLID PRODUCTS FROM FLUE GAS DESULFURIZATION

    Directory of Open Access Journals (Sweden)

    Jan J. Hycnar

    2015-11-01

    Full Text Available Most flue gas desulfurization products can be characterized by significant solubility in water and dusting in dry state. These characteristics can cause a considerable pollution of air, water, and soil. Among many approaches to utilization of this waste, the process of agglomeration using granulation or briquetting has proved very effective. Using desulfurization products a new material of aggregate characteristics has been acquired, and this material is resistant to water and wind erosion as well as to the conditions of transportation and storage. The paper presents the results of industrial trials granulation and briquetting of calcium desulphurization products. The granulation of a mixture of phosphogypsum used with fly ash (in the share 1:5. The resulting granules characterized by a compressive strength of 41.6 MPa, the damping resistance of 70% and 14.2% abrasion. The granulate was used for the production of cement mix. The produced concrete mortar have a longer setting and hardening time, as compared to the traditional ash and gypsum mortar, and have a higher or comparable flexural and compressive strength during hardening. Briquetting trials made of a product called synthetic gypsum or rea-gypsum both in pure form and with the addition of 5% and 10% of the limestone dust. Briquettes have a high initial strength and resistance to abrasion. The values ​​of these parameters increased after 72 hours of seasoning. It was found that higher hardiness of briquettes with rea-gypsum was obtained with the impact of atmospheric conditions and higher resistance to elution of water-soluble components in comparison to ash briquettes.

  11. Solid recovered fuel production through the mechanical-biological treatment of wastes

    OpenAIRE

    Velis, C. A.

    2010-01-01

    This thesis is concerned with the production of solid recovered fuel (SRF) from municipal solid waste using mechanical biological treatment (MBT) plants. It describes the first in-depth analysis of a UK MBT plant and addresses the fundamental research question: are MBT plants and their unit operations optimised to produce high quality SRF in the UK? A critical review of the process science and engineering of MBT provides timely insights into the quality management and standa...

  12. Carbonyl atmospheric reaction products of aromatic hydrocarbons in ambient air

    Science.gov (United States)

    Obermeyer, Genevieve; Aschmann, Sara M.; Atkinson, Roger; Arey, Janet

    To convert gaseous carbonyls to oximes during sampling, an XAD-4 resin denuder system pre-coated with O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine and followed by analysis with methane positive chemical ionization gas chromatography/mass spectrometry was used to measure carbonyls in ambient air samples in Riverside, CA. In conjunction with similar analyses of environmental chamber OH radical-initiated reactions of o- and p-xylene, 1,2,4-trimethylbenzene, ethylbenzene, 4-hydroxy-2-butanone and 1,4-butanediol, we identified benzaldehyde, o-, m- and p-tolualdehyde and acetophenone and the dicarbonyls glyoxal, methylglyoxal, biacetyl, ethylglyoxal, 1,4-butenedial, 3-hexene-2,5-dione, 3-oxo-butanal, 1,4-butanedial and malonaldehyde in the ambient air samples. As discussed, these carbonyls and dicarbonyls can be formed from the OH radical-initiated reactions of aromatic hydrocarbons and other volatile organic compounds emitted into the atmosphere, and we conclude that in situ atmospheric formation is a major source of these carbonyls in our Riverside, CA, ambient air samples.

  13. Isotope effects of reactions in quantum solids initiated by IR + UV lasers: quantum model simulations for Cl((2)P(3/2)) + X(2)(ν) → XCl + X in X(2) matrices (X = H, D).

    Science.gov (United States)

    Korolkov, M V; Manz, J; Schild, A

    2010-09-16

    Six isotope effects (i)-(vi) are discovered for the reactions Cl + H(2)(ν) → HCl + H in solid para-H(2) ( 1 ) versus Cl + D(2)(ν) → DCl + D in ortho-D(2) ( 2 ), by means of quantum reaction dynamics simulations, within the frame of our simple model ( J. Phys. Chem. A 2009 , 113 , 7630 . ). Experimentally, the reactions may be initiated for ν = 0 and ν ≥ 1, by means of "UV only" photodissociation of the matrix-isolated precursor, Cl(2), or by "IR + UV" coirradiation ( Kettwich , S. C. , Raston , P. L. , and Anderson , D. T. J. Phys. Chem. A 2009 , 113 , 7621 . ), respectively. Specifically, (i) various shape and Feshbach reaction resonances correlate with vibrational thresholds of reactants and products, due to the near-thermoneutrality and low barrier of the system. The energetic density of resonances increases as the square root of mass, from M(X) = M(H) to M(D). (ii) The state selective reaction ( 1 ), ν = 1, is supported by a shape resonance, whereas this type of resonance is absent in ( 2 ), ν = 1. As a consequence, time-resolved measurements should monitor different three-step versus direct error-function type evolutions of the formation of the products. (iii) The effective barrier is lower for reaction 1 , ν = 0, enhancing the tunneling rate, as compared to that for reaction 2 , ν = 0. (iv) For reference, the reaction probabilities P versus total energy E(tot) in the gas exhibit sharp resonance peaks or zigzag behaviors of the reaction probability P versus total energy, near the levels of resonances ( Persky , A. and Baer , M. J. Chem. Phys . 1974 , 60 , 133 . ). These features tend to be washed out and broadened for reaction 1 , and even more so for reaction 2 . For comparison, they disappear for reactions in classical solids. (v) The slopes of P versus E(tot) below the potential barrier increase more steeply for reaction 1 , ν = 0, than for reaction 2 , ν = 0. This enhances the tunneling rate of the heavier isotopomer, reaction 2 , ν = 0

  14. Metal Organic Frameworks as Solid Catalysts in Condensation Reactions of Carbonyl Groups

    Czech Academy of Sciences Publication Activity Database

    Dhakshinamoorthy, A.; Opanasenko, Maksym; Čejka, Jiří; Garcia, H.

    2013-01-01

    Roč. 355, 2-3 (2013), s. 247-268 ISSN 1615-4150 R&D Projects: GA ČR GBP106/12/G015 Grant - others:European Commission(XE) FP7/2007-2013, contract 228862 Institutional support: RVO:61388955 Keywords : alcohol condensation * green chemistry * Henry reaction Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 5.542, year: 2013

  15. Solid state diffusion and reaction in ZnO/SiO{sub 2} in thin films

    Energy Technology Data Exchange (ETDEWEB)

    Jakob, A; Stucki, S; Schnyder, B; Koetz, R [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-06-01

    Detoxification of fly ash from waste incineration by evaporating harmful heavy metals is limited by the formation of stable heavy metal-matrix compounds. To study the rate of these heavy metal-matrix reactions, experiments were performed with the diffusion couple ZnO (heavy metal)-SiO{sub 2} (matrix). The atomic concentration profiles after different annealing treatments were analysed by X-ray photoelectron spectroscopy (XPS). (author) 3 figs., 4 refs.

  16. Reaction

    African Journals Online (AJOL)

    abp

    19 oct. 2017 ... Reaction to Mohamed Said Nakhli et al. concerning the article: "When the axillary block remains the only alternative in a 5 year old child". .... Bertini L1, Savoia G, De Nicola A, Ivani G, Gravino E, Albani A et al ... 2010;7(2):101-.

  17. Propulsion of a Molecular Machine by Asymmetric Distribution of Reaction Products

    Science.gov (United States)

    Golestanian, Ramin; Liverpool, Tanniemola B.; Ajdari, Armand

    2005-06-01

    A simple model for the reaction-driven propulsion of a small device is proposed as a model for (part of) a molecular machine in aqueous media. The motion of the device is driven by an asymmetric distribution of reaction products. The propulsive velocity of the device is calculated as well as the scale of the velocity fluctuations. The effects of hydrodynamic flow as well as a number of different scenarios for the kinetics of the reaction are addressed.

  18. A nanojet: propulsion of a molecular machine by an asymmetric distribution of reaction--products

    Science.gov (United States)

    Liverpool, Tanniemola; Golestanian, Ramin; Ajdari, Armand

    2006-03-01

    A simple model for the reaction-driven propulsion of a small device is proposed as a model for (part of) a molecular machine in aqueous media. Motion of the device is driven by an asymmetric distribution of reaction products. We calculate the propulsive velocity of the device as well as the scale of the velocity fluctuations. We also consider the effects of hydrodynamic flow as well as a number of different scenarios for the kinetics of the reaction.

  19. Reactions of 3-Formylchromone with Active Methylene and Methyl Compounds and Some Subsequent Reactions of the Resulting Condensation Products

    Directory of Open Access Journals (Sweden)

    M. Lácova

    2005-08-01

    Full Text Available This review presents a survey of the condensations of 3-formylchromone with various active methylene and methyl compounds, e.g. malonic or barbituric acid derivatives, five-membered heterocycles, etc. The utilisation of the condensation products for the synthesis of different heterocyclic systems, which is based on the ability of the γ-pyrone ring to be opened by the nucleophilic attack is also reviewed. Finally, the applications of microwave irradiation as an unconventional method of reaction activation in the synthesis of condensation products is described and the biological activity of some chromone derivatives is noted.

  20. The effects of reactants ratios, reaction temperatures and times on Maillard reaction products of the L-ascorbic acid/L-glutamic acid system

    Directory of Open Access Journals (Sweden)

    Yong-Yan ZHOU

    2016-01-01

    Full Text Available Abstract The transformation law of the Maillard reaction products with three different reactants ratios - equimolar reactants, excess L-glutamic acid and excess L-ascorbic acid reaction respectively, five different temperatures, and different time conditions for the L-ascorbic acid / L-glutamic acid system were investigated. Results showed that, the increase of the reaction time and temperature led to the increase of the browning products, uncoloured intermediate products, as well as aroma compounds. Compared with the equimolar reaction system, the excess L-ascorbic acid reaction system produced more browning products and uncoloured intermediate products, while the aroma compounds production remained the same. In the excess L-glutamic acid system, the uncoloured intermediate products increased slightly, the browning products remained the same, while the aroma compounds increased.

  1. Hydrogen and methane production from household solid waste in the two-stage fermentation process

    DEFF Research Database (Denmark)

    Lui, D.; Liu, D.; Zeng, Raymond Jianxiong

    2006-01-01

    A two-stage process combined hydrogen and methane production from household solid waste was demonstrated working successfully. The yield of 43 mL H-2/g volatile solid (VS) added was generated in the first hydrogen production stage and the methane production in the second stage was 500 mL CH4/g VS...... added. This figure was 21% higher than the methane yield from the one-stage process, which was run as control. Sparging of the hydrogen reactor with methane gas resulted in doubling of the hydrogen production. PH was observed as a key factor affecting fermentation pathway in hydrogen production stage....... Furthermore, this study also provided direct evidence in the dynamic fermentation process that, hydrogen production increase was reflected by acetate to butyrate ratio increase in liquid phase. (c) 2006 Elsevier Ltd. All rights reserved....

  2. Chemistry by nanocatalysis: First example of a solid-supported RAPTA complex for organic reactions in aqueous medium

    KAUST Repository

    García-Garrido, Sergio E.

    2010-11-18

    A ruthenium-arene-PTA (RAPTA) complex has been supported for the first time on an inorganic solid, that is, silica-coated ferrite nanoparticles. The resulting magnetic material proved to be a general, very efficient and easily reusable catalyst for three synthetically useful organic transformations; selective nitrile hydration, redox isomerization of allylic alcohols, and heteroannulation of (Z)-enynols. The use of low metal concentration, environmentally friendly water as a reaction medium, with no use at all of organic solvent during or after the reactions, and microwaves as an alternative energy source renders the synthetic processes reported herein "truly" green and sustainable. RAPTA\\'s delight: A nano-RAPTA complex supported on silica-coated ferrite nanoparticles proved to be a general, very efficient and easily reusable catalyst for three synthetically useful organic transformations; selective nitrile hydration, redox isomerization of allylic alcohols, and heteroannulation of (Z)-enynols. The use of low metal concentrations, water as a reaction medium, and microwaves as an energy source renders these processes green and sustainable. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Tri-potassium phosphate as a solid catalyst for biodiesel production from waste cooking oil

    Energy Technology Data Exchange (ETDEWEB)

    Guan, Guoqing; Kusakabe, Katsuki; Yamasaki, Satoko [Department of Living Environmental Science, Fukuoka Women' s University, 1-1-1 Kasumigaoka, Higashi-ku, Fukuoka 813-8529 (Japan)

    2009-04-15

    Transesterification of waste cooking oil with methanol, using tri-potassium phosphate as a solid catalyst, was investigated. Tri-potassium phosphate shows high catalytic properties for the transesterification reaction, compared to CaO and tri-sodium phosphate. Transesterification of waste cooking oil required approximately two times more solid catalyst than transesterification of sunflower oil. The fatty acid methyl ester (FAME) yield reached 97.3% when the transesterification was performed with a catalyst concentration of 4 wt.% at 60 C for 120 min. After regeneration of the used catalyst with aqueous KOH solution, the FAME yield recovered to 88%. Addition of a co-solvent changed the reaction state from three-phase to two-phase, but reduced the FAME yield, contrary to the results with homogeneous catalysts. The catalyst particles were easily agglomerated by the glycerol drops derived from the homogeneous liquid in the presence of co-solvents, reducing the catalytic activity. (author)

  4. Advances of zeolite based membrane for hydrogen production via water gas shift reaction

    Science.gov (United States)

    Makertihartha, I. G. B. N.; Zunita, M.; Rizki, Z.; Dharmawijaya, P. T.

    2017-07-01

    Hydrogen is considered as a promising energy vector which can be obtained from various renewable sources. However, an efficient hydrogen production technology is still challenging. One technology to produce hydrogen with very high capacity with low cost is through water gas shift (WGS) reaction. Water gas shift reaction is an equilibrium reaction that produces hydrogen from syngas mixture by the introduction of steam. Conventional WGS reaction employs two or more reactors in series with inter-cooling to maximize conversion for a given volume of catalyst. Membrane reactor as new technology can cope several drawbacks of conventional reactor by removing reaction product and the reaction will favour towards product formation. Zeolite has properties namely high temperature, chemical resistant, and low price makes it suitable for membrane reactor applications. Moreover, it has been employed for years as hydrogen selective layer. This review paper is focusing on the development of membrane reactor for efficient water gas shift reaction to produce high purity hydrogen and carbon dioxide. Development of membrane reactor is discussed further related to its modification towards efficient reaction and separation from WGS reaction mixture. Moreover, zeolite framework suitable for WGS membrane reactor will be discussed more deeply.

  5. Recent applications of intramolecular Diels-Alder reactions to natural product synthesis

    DEFF Research Database (Denmark)

    Juhl, M.; Tanner, David Ackland

    2009-01-01

    This tutorial review presents some recent examples of intramolecular Diels-Alder (IMDA) reactions as key complexity-generating steps in the total synthesis of structurally intricate natural products. The opportunities afforded by transannular (TADA) versions of the IMDA reaction in complex molecu...... comprehensive, reviews....

  6. Mapping Students' Conceptual Modes When Thinking about Chemical Reactions Used to Make a Desired Product

    Science.gov (United States)

    Weinrich, M. L.; Talanquer, V.

    2015-01-01

    The central goal of this qualitative research study was to uncover major implicit assumptions that students with different levels of training in the discipline apply when thinking and making decisions about chemical reactions used to make a desired product. In particular, we elicited different ways of conceptualizing why chemical reactions happen…

  7. Chemical methods and techniques to monitor early Maillard reaction in milk products; A review.

    Science.gov (United States)

    Aalaei, Kataneh; Rayner, Marilyn; Sjöholm, Ingegerd

    2018-01-23

    Maillard reaction is an extensively studied, yet unresolved chemical reaction that occurs as a result of application of the heat and during the storage of foods. The formation of advanced glycation end products (AGEs) has been the focus of several investigations recently. These molecules which are formed at the advanced stage of the Maillard reaction, are suspected to be involved in autoimmune diseases in humans. Therefore, understanding to which extent this reaction occurs in foods, is of vital significance. Because of their composition, milk products are ideal media for this reaction, especially when application of heat and prolonged storage are considered. Thus, in this work several chemical approaches to monitor this reaction in an early stage are reviewed. This is mostly done regarding available lysine blockage which takes place in the very beginning of the reaction. The most popular methods and their applications to various products are reviewed. The methods including their modifications are described in detail and their findings are discussed. The present paper provides an insight into the history of the most frequently-used methods and provides an overview on the indicators of the Maillard reaction in the early stage with its focus on milk products and especially milk powders.

  8. Change in enzyme production by gradually drying culture substrate during solid-state fermentation.

    Science.gov (United States)

    Ito, Kazunari; Gomi, Katsuya; Kariyama, Masahiro; Miyake, Tsuyoshi

    2015-06-01

    The influence of drying the culture substrate during solid-state fermentation on enzyme production was investigated using a non-airflow box. The drying caused a significant increase in enzyme production, while the mycelium content decreased slightly. This suggests that changes in the water content in the substrate during culture affect enzyme production in fungi. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  9. Optimization of culture conditions for tannase production by Aspergillus sp. gm4 in solid state fermentation

    OpenAIRE

    Souza, Patrícia Nirlane da Costa; Universidade Federal de Lavras; Maia, Natália da Costa; Universidade Federal de Lavras; Guimarães, Luís Henrique Souza; Universidade de São Paulo; Resende, Mário Lúcio Vilela de; Universidade Federal de Lavras; Cardoso, Patrícia Gomes; Universidade Federal de Lavras

    2015-01-01

    The production of tannase by Aspergillus sp. GM4 under solid-state fermentation (SSF)  was investigated using different vegetables leaves such as mango, jamun, coffee and agricultural residues such as coffee husks, rice husks and wheat bran. Among substrates used jamun leaves yielded high tannase production. The Plackett-Burman design was conducted to evaluate the effects of 12 independent variables on the production of tannase under SSF using jamun leaves as substrate. Among these variables,...

  10. Standardized high current solid targets for cyclotron production of radionuclides

    International Nuclear Information System (INIS)

    Al-Jammaz, Ibrahim

    2000-01-01

    The Cyclotron and Radiopharmaceuticals Department (CRP) is an advanced and modern facility that encompasses two essential components: radioisotope research, and radiopharmaceuticals manufacturing. Radiopharmaceuticals manufacturing program is not only quite unique, but also an essential component of King Faisal Specialist Hospital and Research Center (KFSH and RC) in providing quality patient care for the population of the Kingdom. Accurate diagnosis and therapy with medical imaging equipment requires quality radiopharmaceuticals that are available readily and with reliability. The CRP Department provides that quality and reliability. Research activities of the CRP Department are focused on developing new radiotracers with potential usefulness in biomedical research and clinical applications. Research projects consist of: developing cyclotron targetry for radioisotope production; developing synthesis methods for radiolabeling biomolecules; and developing analytical methods for quality control. The CRP Department operates a semi-commercial radiopharmaceuticals manufacturing program that supplies the diagnostic radioactive products to several hospitals in the Kingdom and neighboring countries. These products for clinical applications are produced according to the international standards of Good Manufacturing Practices of quality and efficacy. At the heart of the radioisotope program is a medium energy cyclotron capable of accelerating a number of particles for transformation of non-radioactive atoms into radionuclides that are the primary sources for research and development activities, and for preparing radiopharmaceuticals. In addition to having the only cyclotron facility in the region, KFSH and RC also has the only Positron Emission Tomography Center (PET) in this part of the world. This combination of cyclotron and the ultra modern PET facility translates into advanced and specialized care for the patients at KFSH and RC

  11. BIOLEACH: Coupled modeling of leachate and biogas production on solid waste landfills

    Science.gov (United States)

    Rodrigo-Clavero, Maria-Elena; Rodrigo-Ilarri, Javier

    2015-04-01

    One of the most important factors to address when performing the environmental impact assessment of urban solid waste landfills is to evaluate the leachate production. Leachate management (collection and treatment) is also one of the most relevant economical aspects to take into account during the landfill life. Leachate is formed as a solution of biological and chemical components during operational and post-operational phases on urban solid waste landfills as a combination of different processes that involve water gains and looses inside the solid waste mass. Infiltration of external water coming from precipitation is the most important component on this water balance. However, anaerobic waste decomposition and biogas formation processes play also a role on the balance as water-consuming processes. The production of leachate one biogas is therefore a coupled process. Biogas production models usually consider optimal conditions of water content on the solid waste mass. However, real conditions during the operational phase of the landfill may greatly differ from these optimal conditions. In this work, the first results obtained to predict both the leachate and the biogas production as a single coupled phenomenon on real solid waste landfills are shown. The model is applied on a synthetic case considering typical climatological conditions of Mediterranean catchments.

  12. Radioactive nuclide production and isomeric state branching ratios in P + W reactions to 200 mev

    International Nuclear Information System (INIS)

    Young, P.G.; Chadwick, M.B.

    1995-01-01

    Calculations of nuclide yields from spallation reactions usually assume that the products are formed in their ground states. We are performing calculations of product yields from proton reactions on tungsten isotopes that explicitly account for formation of the residual nuclei in excited states. The Hauser-Feshbach statistical/preequilibrium code GNASH, with full accounting for angular momentum conservation and electromagnetic transitions, is utilized in the calculations. We present preliminary results for isomer branching ratios for proton reactions to 200 MeV for several products including the 31-y, 16+ state in l78 Hf and the 25-d, 25/2- state in 179 Hf. Knowledge of such branching ratios, might be important for concepts such as accelerator production of tritium that utilize intermediate-energy proton reactions on tungsten

  13. A new branch of advertising: reviewing factors that influence reactions to product placement

    NARCIS (Netherlands)

    van Reijmersdal, E.; Neijens, P.; Smit, E.G.

    2009-01-01

    This iiterature review presents a quantitative synthesis of 57 studies on product placement and shows which factors are most effective, it shows that placement characteristics, such as placement commerciality, modality, and prominence, have a strong impact on audience reactions. Audience

  14. Liquid composition having ammonia borane and decomposing to form hydrogen and liquid reaction product

    Science.gov (United States)

    Davis, Benjamin L; Rekken, Brian D

    2014-04-01

    Liquid compositions of ammonia borane and a suitably chosen amine borane material were prepared and subjected to conditions suitable for their thermal decomposition in a closed system that resulted in hydrogen and a liquid reaction product.

  15. Large fragment production calculations in relativistic heavy-ion reactions

    International Nuclear Information System (INIS)

    Seixas de Oliveira, L.F.

    1978-12-01

    The abrasion-ablation model is briefly described and then used to calculate cross sections for production of large fragments resulting from target or projectile fragmentation in high-energy heavy-ion collisions. The number of nucleons removed from the colliding nuclei in the abrasion stage and the excitation energy of the remaining fragments (primary products) are calculated with the geometrical picture of two different models: the fireball and the firestreak models. The charge-to-mass dispersion of the primary products is calculated using either a model which assumes no correlations between proton and neutron positions inside the nucleus (hypergeometric distribution) or a model based upon the zero-point oscillations of the giant dipole resonance (NUC-GDR). Standard Weisskopf--Ewing statistical evaporation calculations are used to calculate final product distributions. Results of the pure abrasion-ablation model are compared with a variety of experimental data. The comparisons show the insufficiency of the extra-surface energy term used in the abrasion calculations. A frictional spectator interaction (FSI) is introduced which increases the average excitation energy of the primary products, and improves the results considerably in most cases. Agreements and discrepancies of the results calculated with the different theoretical assumptions and the experimental data are studied. Of particular relevance is the possibility of observing nuclear ground-state correlations.Results of the recently completed experiment of fragmentation of 213 Mev/A 40 Ar projectiles are studied and shown not to be capable of answering that question unambiguously. But predictions for the upcoming 48 Ca fragmentation experiment clearly show the possibility of observing correlation effects. 78 references

  16. New paradigm for simplified combustion modeling of energetic solids: Branched chain gas reaction

    Energy Technology Data Exchange (ETDEWEB)

    Brewster, M.Q.; Ward, M.J. [Univ. of Illinois, Urbana, IL (United States); Son, S.F. [Los Alamos National Lab., NM (United States)

    1997-09-01

    Two combustion models with simple but rational chemistry are compared: the classical high gas activation energy (E{sub g}/RT {much_gt} 1) Denison-Baum-Williams (DBW) model, and a new low gas activation energy (E{sub g}/RT {much_lt} 1) model recently proposed by Ward, Son, and Brewster (WSB). Both models make the same simplifying assumptions of constant properties, Lewis number unity, single-step, second order gas phase reaction, and single-step, zero order, high activation energy condensed phase decomposition. The only difference is in the gas reaction activation energy E{sub g} which is asymptotically large for DBW and vanishingly small for WSB. For realistic parameters the DBW model predicts a nearly constant temperature sensitivity {sigma}{sub p} and a pressure exponent n approaching 1. The WSB model predicts generally observed values of n = 0.7 to 0.9 and {sigma}{sub p}(T{sub o},P) with the generally observed variations with temperature (increasing) and pressure (decreasing). The WSB temperature profile also matches measured profiles better. Comparisons with experimental data are made using HMX as an illustrative example (for which WSB predictions for {sigma}{sub p}(T{sub o},P) are currently more accurate than even complex chemistry models). WSB has also shown good agreement with NC/NG double base propellant and HNF, suggesting that at the simplest level of combustion modeling, a vanishingly small gas activation energy is more realistic than an asymptotically large one. The authors conclude from this that the important (regression rate determining) gas reaction zone near the surface has more the character of chain branching than thermal decomposition.

  17. Evaluated kinetic and photochemical data for atmospheric chemistry: Volume V – heterogeneous reactions on solid substrates

    Directory of Open Access Journals (Sweden)

    J. N. Crowley

    2010-09-01

    Full Text Available This article, the fifth in the ACP journal series, presents data evaluated by the IUPAC Subcommittee on Gas Kinetic Data Evaluation for Atmospheric Chemistry. It covers the heterogeneous processes on surfaces of solid particles present in the atmosphere, for which uptake coefficients and adsorption parameters have been presented on the IUPAC website in 2010. The article consists of an introduction and guide to the evaluation, giving a unifying framework for parameterisation of atmospheric heterogeneous processes. We provide summary sheets containing the recommended uptake parameters for the evaluated processes. Four substantial appendices contain detailed data sheets for each process considered for ice, mineral dust, sulfuric acid hydrate and nitric acid hydrate surfaces, which provide information upon which the recommendations are made.

  18. Solid-state reaction in Fe/V multilayers by ion beam mixing with thermal annealing

    International Nuclear Information System (INIS)

    Borges, J.F.M.; Costa, M.I. da Jr.; Teixeira, S.R.; Cunha, J.B.M. da; Alves, M.C.M.

    2001-01-01

    We report a study on the structural and magnetic properties of iron-vanadium thin films, originally grown in multilayer form [Fe(20 A)/V(20 A)] 20 , and mixed by ion beam mixing (IBM) and a subsequent thermal treatment. The samples were structurally characterised by X-ray diffraction (XRD) in the θ-2θ geometry and X-ray absorption spectroscopy (XAS). The magnetic characterisation was made using conversion electron Moessbauer spectroscopy (CEMS). The XRD result for the as-deposited multilayer shows a high-degree crystallinity, while CEMS suggests abrupt interface, since no significant contribution from vanadium in iron is observed. After the IBM and thermal treatment, the results from XRD show an FeV solid solution indexed as a bcc-disordered structure (α phase). XAS structural results are consistent with the XRD observations. CEMS results show a magnetic moment reduction for mixed samples

  19. Granular flow considerations in the design of a cascade solid breeder reaction chamber

    International Nuclear Information System (INIS)

    Walton, O.R.

    1983-10-01

    Both horizontally and vertically oriented rotating chambers with granular material held on the inner surface by centrifugal action are examined. Modifications to the condition for controlled quasi-static flow on an incline plane, phi/sub w/ 0 +- 10 0 for ceramic particles and metal surfaces. For vertical orientations the maximum half-angle of the top cone is slightly less than the wall friction angle phi/sub w/ while the lower portion can have a half angle as large as (90 0 - phi/sub w). Percolation of fines through shearing granular solids is briefly discussed and recommended experimental and calculational studies to obtain a better understanding of this behavior are described

  20. Nanoscale formation of new solid-state compounds by topochemical effects: The interfacial reactions ZnO with Al2O3 as a model system

    International Nuclear Information System (INIS)

    Pin, Sonia; Ghigna, Paolo; Spinolo, Giorgio; Quartarone, Eliana; Mustarelli, Piercarlo; D'Acapito, Francesco; Migliori, Andrea; Calestani, Gianluca

    2009-01-01

    The chemical reactivity of thin layers (ca. 10 nm thick) of ZnO deposited onto differently oriented Al 2 O 3 single crystals has been investigated by means of atomic force microscopy inspections and X-ray absorption spectroscopy at the Zn-K edge. The (0001) ZnO -parallel (112-bar0) sapphire interface yields the ZnAl 2 O 4 spinel and a quite stable film morphology. Instead, the (112-bar0) ZnO -parallel (11-bar02) sapphire and (0001) ZnO -parallel (0001) sapphire interfaces give origin to a new compound (or, possibly, even two new compounds), whose chemical nature is most likely that of a ZnO/Al 2 O 3 phase, with still unknown composition and crystal structure. In addition, in the last two cases, films collapse into prismatic twins of ca. 1 μm in dimension. These experimental findings demonstrate that in a solid-state reaction, the topotactical relationships between the reacting solids are of crucial importance not only in determining the kinetic and mechanisms of the process in its early stages, but even the chemical nature of the product. - Graphical abstract: EXAFS Fourier transforms and morphology of different reactive interfaces between ZnO and Al 2 O 3 .

  1. Preparation and characterization of mechanically alloyed AB3-type based material LaMg2Ni5Al4 and its solid-gaz hydrogen storage reaction

    Science.gov (United States)

    Jaafar, Hassen; Aymard, Luc; Dachraoui, Walid; Demortière, Arnaud; Abdellaoui, Mohieddine

    2018-04-01

    We developed in the present paper the synthesis of a new AB3-type compound LaMg2Ni5Al4 by mechanical alloying (MA) process. ​​X-ray diffraction analysis (XRD) was used to determine the structural properties and the phase evolution of the powder mixtures. Two different synthesis pathways have been investigated. The first starting from elemental metals and the second from a mixture of two binary compounds LaNi5 (CaCu5-type structure, P6/mmm space group) and Al(Mg) solid solution (cubic Fm-3 m space group). The results show multiphase alloys which contain LaMg2Ni5Al4 main phase with hexagonal PuNi3-type structure (R-3 m space group). Rietveld analysis shows that using a planetary ball mill, we obtain a good yield of LaMg2Ni5Al4 compound after 5 h of mechanical alloying for both synthesis pathways. TEM analysis confirmed XRD results. SEM-EDX analysis of the final product was in agreement with the nominal chemical formula. A setup of possible solid-gaz hydrogenation reaction will be described so far at the end of this work. Electrochemical results demonstrate evidence on hydrogen absorption in the AB3 material and the discharge capacity was equal to 5.9 H/f.u.

  2. The unexpected product of Diels-Alder reaction between "indanocyclon" and maleimide

    Science.gov (United States)

    Dobrowolski, Michał A.; Roszkowski, Piotr; Struga, Marta; Szulczyk, Daniel

    2017-02-01

    A heterocyclic compound commonly known as "indanocyclon" undergoes an unexpected Diels-Alder addition with maleimide. The resulting product has been isolated and characterized in order to get an information about its structure and possible mechanism of the reaction. Extensive comparison of single crystal properties of 3-(2,8-dioxo-1,3-diphenyl-2,8-dihydrocyclopenta[a]inden-8a(1H)-yl)pyrrolidine-2,5-dione and favorable product of the reaction has been also performed.

  3. Durable solid oxide electrolysis cells for hydrogen production

    DEFF Research Database (Denmark)

    Sun, Xiufu; Chen, Ming; Hendriksen, Peter Vang

    2014-01-01

    production is required for promoting commercialization of the SOEC technology. In this work, we report a recent 4400 hours test of a state-of-the-art Ni-YSZ electrode supported SOEC cell. The cell consists of a Ni-YSZ (YSZ: yttria stabilized zirconia) support and active fuel electrode, an YSZ electrolyte...... that except for the first 250 hours fast initial degradation, for the rest of the testing period, the cell showed rather stable performance with an moderate degradation rate of around 25 mV/1000 h. The electrochemical impedance spectra show that both serial resistance and polarization resistance of the cell...... and changing of porosity inside the active layer. The degree of these microstructural changes becomes less and less severe along the hydrogen-steam flow path. The present test results show that this type of cell can be used for early demonstration electrolysis at 1A/cm2. Future work should be focus on reducing...

  4. Batch Fermentative Biohydrogen Production Process Using Immobilized Anaerobic Sludge from Organic Solid Waste

    Directory of Open Access Journals (Sweden)

    Patrick T. Sekoai

    2016-12-01

    Full Text Available This study examined the potential of organic solid waste for biohydrogen production using immobilized anaerobic sludge. Biohydrogen was produced under batch mode at process conditions of 7.9, 30.3 °C and 90 h for pH, temperature and fermentation time, respectively. A maximum biohydrogen fraction of 48.67%, which corresponded to a biohydrogen yield of 215.39 mL H2/g Total Volatile Solids (TVS, was achieved. Therefore, the utilization of immobilized cells could pave the way for a large-scale biohydrogen production process.

  5. Modelling biogas production of solid waste: application of the BGP model to a synthetic landfill

    Science.gov (United States)

    Rodrigo-Ilarri, Javier; Segura-Sobrino, Francisco

    2013-04-01

    Production of biogas as a result of the decomposition of organic matter included on solid waste landfills is still an issue to be understood. Reports on this matter are rarely included on the engineering construction projects of solid waste landfills despite it can be an issue of critical importance while operating the landfill and after its closure. This paper presents an application of BGP (Bio-Gas-Production) model to a synthetic landfill. The evolution in time of the concentrations of the different chemical compounds of biogas is studied. Results obtained show the impact on the air quality of different management alternatives which are usually performed in real landfills.

  6. Lambda-HYPERNUCLEAR PRODUCTION IN (K(stop)(-), pi) REACTIONS

    Czech Academy of Sciences Publication Activity Database

    Krejčiřík, Vojtěch; Cieplý, Aleš

    2011-01-01

    Roč. 26, 3-4 (2011), s. 663-664 ISSN 0217-751X. [11th International Workshop on Meson Production, Properties and Interaction. Krakow, 10.06.2010-15.06.2010] R&D Projects: GA ČR GA202/09/1441 Institutional research plan: CEZ:AV0Z10480505 Keywords : Hypernuclei * DWIA * chiral model Subject RIV: BE - Theoretical Physics Impact factor: 1.053, year: 2011

  7. Laser application for nuclear reaction product detecting system alignment

    International Nuclear Information System (INIS)

    Grantsev, V.I.; Dryapachenko, I.P.; Kornilov, V.A.; Nemets, O.F.; Rudenko, B.A.; Sokolov, M.V.; Struzhko, B.G.; Gnatovskij, A.V.; Bojchuk, V.N.

    1982-01-01

    A method for optical alignment of nuclear particle detector system using a laser beam and hologram is described. The method permits to arrange detectors very precisely in accordance with any chosen space coordinate values. The results of modelling the geometry of an experiment based on using the suggested method on cyclotron beams are described. A gas helium-neon laser with wavelength of 0.63 μm radiation power of an order of 2 MW and angular beam divergence less than 10 angular minutes is used for modelling. It is concluded that the laser and hologram application provides large possibilities for the modelling the geometry of experiments on nuclear reaction investigation. When necessary it is possible to obtain small nonius scale of reference beams by means of multiplicating properties of the wave front modulator-hologram system. It is also possible to record holograms shaping the reference beams in two or several planes crossing along the central beam direction. Such holograms can be used for modelling the noncoplanar geometry of correlation experiments [ru

  8. Aromatic products from reaction of lignin model compounds with UV-alkaline peroxide

    International Nuclear Information System (INIS)

    Sun, Y.P.; Wallis, A.F.A.; Nguyen, K.L.

    1997-01-01

    A series of guaiacyl and syringyl lignin model compounds and their methylated analogues were reacted with alkaline hydrogen peroxide while irradiating with UV light at 254 nm. The aromatic products obtained were investigated by gas chromatography-mass spectrometry (GC-MS). Guaiacol, syringol and veratrol gave no detectable aromatic products. However, syringol methyl ether gave small amounts of aromatic products, resulting from ring substitution and methoxyl displacement by hydroxyl radicals. Reaction of vanillin and syringaldehyde gave the Dakin reaction products, methoxy-1,4-hydroquinones, while reaction of their methyl ethers yielded benzoic acids. Acetoguaiacone, acetosyringone and their methyl ethers afforded several hydroxylated aromatic products, but no aromatic products were identified in the reaction mixtures from guaiacylpropane and syringylpropane. In contrast, veratrylpropane gave a mixture from which 17 aromatic hydroxylated compounds were identified. It is concluded that for phenolic lignin model compounds, particularly those possessing electrondonating aromatic ring substituents, ring-cleavage reactions involving superoxide radical anions are dominant, whereas for non-phenolic lignin models, hydroxylation reactions through attack of hydroxyl radicals prevail

  9. Estimation of product specific emissions from municipal solid waste landfills for the inventory phase in LCA

    DEFF Research Database (Denmark)

    Nielsen, Per Henning; Hauschild, Michael Zwicky

    1998-01-01

    is frequently given as a quantity of solid wasteand possibly some recovered energy from waste incineration.Since product specific emissions can not be calculated or measured directly at the landfills, they must be estimated by modeling oflandfill processes. This paper presents a landfill model based on a large......), and inorganic non-metals (e.g. chlorine,) which are considered individually. The computer toolLCA-LAND is useful for estimation of emissions from specific waste products disposed in municipal solid waste landfills in Europeancountries (for the present Denmark, Germany and The Netherlands). Input data...... of materials and components and the manufacture, transportation and use of the product to thefinal disposal and possible recycling of the product. Although LCA has developed significantly during recent years, product specific emissions from disposed waste have only got minorattention in the literature leaving...

  10. Origin of stabilization and destabilization in solid-state redox reaction of oxide ions for lithium-ion batteries.

    Science.gov (United States)

    Yabuuchi, Naoaki; Nakayama, Masanobu; Takeuchi, Mitsue; Komaba, Shinichi; Hashimoto, Yu; Mukai, Takahiro; Shiiba, Hiromasa; Sato, Kei; Kobayashi, Yuki; Nakao, Aiko; Yonemura, Masao; Yamanaka, Keisuke; Mitsuhara, Kei; Ohta, Toshiaki

    2016-12-23

    Further increase in energy density of lithium batteries is needed for zero emission vehicles. However, energy density is restricted by unavoidable theoretical limits for positive electrodes used in commercial applications. One possibility towards energy densities exceeding these limits is to utilize anion (oxide ion) redox, instead of classical transition metal redox. Nevertheless, origin of activation of the oxide ion and its stabilization mechanism are not fully understood. Here we demonstrate that the suppression of formation of superoxide-like species on lithium extraction results in reversible redox for oxide ions, which is stabilized by the presence of relatively less covalent character of Mn 4+ with oxide ions without the sacrifice of electronic conductivity. On the basis of these findings, we report an electrode material, whose metallic constituents consist only of 3d transition metal elements. The material delivers a reversible capacity of 300 mAh g -1 based on solid-state redox reaction of oxide ions.

  11. Multifilamentary superconducting (NbTa)-Sn composite wire by solid-liquid reaction for possible application above 20 tesla

    International Nuclear Information System (INIS)

    Hong, M.; Hull, G.W. Jr.; Fuchs, E.O.; Holthuis, J.T.

    1983-01-01

    Nb alloyed with Ta was employed in fabricating multifilamentary composite wires of (NbTa)-Sn using the liquid-infiltration process. The superconducting A15 phase was formed with subsequent heat treatments at 800-950 0 C by the solid-liquid reaction. High inductive Tsub(c)'s of 18.2 K with sharp transition width ( 4 A/cm 2 at 2O T and 4.2 K were obtained. It was found that 2 wt.% Ta in the Nb was sufficient in the enhancement of the overall Jsub(c) at the high fields and in increasing the Hsub(c2) (4.2 K) to 25 T. (Auth.)

  12. Multifilamentary superconducting (NbTa)-Sn composite wire by solid-liquid reaction for possible application above 20 tesla

    International Nuclear Information System (INIS)

    Hong, M.; Hull, G.W. Jr.; Fuchs, E.O.; Holthuis, J.T.

    1983-01-01

    Nb alloyed with Ta was employed in fabricating multifilamentary composite wires of (NbTa)-Sn using the liquid-infiltration process. The superconducting A15 phase was formed with subsequent heat treatments at 800-950 0 C by the solid-liquid reaction. High inductive Tsub(c)'s of 18.2 K with sharp transition width ( 4 A/cm 2 at 20 T and 4.2 K were obtained. It was found that 2 wt.% Ta in the Nb was sufficient in the enhancement of the overall Jsub(c) at the high fields and in increasing the Hsub(c2) (4.2 K) to 25 T. (orig.)

  13. Origin of stabilization and destabilization in solid-state redox reaction of oxide ions for lithium-ion batteries

    Science.gov (United States)

    Yabuuchi, Naoaki; Nakayama, Masanobu; Takeuchi, Mitsue; Komaba, Shinichi; Hashimoto, Yu; Mukai, Takahiro; Shiiba, Hiromasa; Sato, Kei; Kobayashi, Yuki; Nakao, Aiko; Yonemura, Masao; Yamanaka, Keisuke; Mitsuhara, Kei; Ohta, Toshiaki

    2016-01-01

    Further increase in energy density of lithium batteries is needed for zero emission vehicles. However, energy density is restricted by unavoidable theoretical limits for positive electrodes used in commercial applications. One possibility towards energy densities exceeding these limits is to utilize anion (oxide ion) redox, instead of classical transition metal redox. Nevertheless, origin of activation of the oxide ion and its stabilization mechanism are not fully understood. Here we demonstrate that the suppression of formation of superoxide-like species on lithium extraction results in reversible redox for oxide ions, which is stabilized by the presence of relatively less covalent character of Mn4+ with oxide ions without the sacrifice of electronic conductivity. On the basis of these findings, we report an electrode material, whose metallic constituents consist only of 3d transition metal elements. The material delivers a reversible capacity of 300 mAh g−1 based on solid-state redox reaction of oxide ions. PMID:28008955

  14. User's guide to PROTOCOL, a numerical simulator for the dissolution reactions of inorganic solids in aqueous solutions

    International Nuclear Information System (INIS)

    Pickrell, G.; Jackson, D.D.

    1984-10-01

    This report provides a user's manual for PROTOCOL, a comprehensive coupled kinetic/equilibrium computer program for analyzing the dissolution reactions of solids with aqueous solutions, specifically applied to the potential corrosion of vitrified nuclear waste by groundwater. The capabilities and available options are summarized as well as instructions for setting up and running problems. Also described in this report and included in the PROTOCOL software package are MASTER, a master file of species thermodynamic data, MANEQL, a preprocessor program and POSTP, a postprocessor. POSTP provides offline plotting using the CRAY-1 DISSPLA 9.0 graphics library. PROTOCOL is operational on the CDC-7600 and CRAY-1 computers at the Lawrence Livermore National Laboratory. 7 references, 10 figures, 2 tables

  15. Spectroscopic and Electrochemical Properties of Lithium-Rich LiFePO4 Cathode Synthesized by Solid-State Reaction

    Science.gov (United States)

    Rosaiah, P.; Hussain, O. M.; Zhu, Jinghui; Qiu, Yejun

    2017-08-01

    Lithium iron phosphate (Li x FePO4) is synthesized by a solid-state reaction method. The structural, electrical and electrochemical properties are studied in detail. It is found that the increment of lithium concentration (up to x = 1.05) does not affect the structure of LiFePO4 but improves its electrical conductivity as well as electrochemical performance. Surface morphological studies exhibited the formation of rod-like nanoparticles with small size. Electric and dielectric properties are also investigated over a frequency range of 1 Hz-1 MHz at different temperatures. The conductivity increased with increasing temperature, which follows the Arrhenius relation with the activation energy of about 0.31 eV. And the electrochemical tests found that the Li1.05FePO4 cathode possessed improved discharge capacity with better cycling performance.

  16. In situ Spectroscopy of Solid-State Chemical Reaction in PbBr2-Deposited CsBr Crystals

    Science.gov (United States)

    Kondo, Shin-ichi; Matsunaga, Toshihiro; Saito, Tadaaki; Asada, Hiroshi

    2003-09-01

    It is possible to measure the fundamental optical absorption spectra of CsPbBr3 and Cs4PbBr6, whose stability is predicted by the study of phase diagram in the binary system CsBr-PbBr2, by means of in situ optical absorption and reflection spectroscopy of thermally induced solid-state chemical reaction in PbBr2-deposited CsBr crystals. On heavy annealing of the crystals, the Pb2+ ions are uniformly dispersed in the crystal matrix. The present experiment provides a novel method for measuring intrinsic optical absorption of ternary metal halides and also for in situ monitoring of doping metal halide crystal with impurities (metal ions or halogen ions).

  17. Application of radioanalytical techniques in the study of the products of heavy-ion reactions

    International Nuclear Information System (INIS)

    Hoffman, D.C.

    1989-01-01

    The use of heavy ions to induce nuclear reactions was reported as early as 1950. Since then it has been one of the most active areas of nuclear research. Intense beams of ions as heavy as uranium with energies high enough to overcome the Coulomb barriers of even the heaviest elements are available. The large variety of possible reactions gives rise to a multitude of products, which have been studied by many chemical and physical techniques. Chemical techniques have been of special value for the separation and unequivocal identification of low-yield species from the plethora of other nuclides present. Heavy-ion reactions have been essential for the production of the transmendelevium elements and a host of new isotopes. The systematics of compound nucleus reactions, transfer reactions and deeply inelastic reactions have been elucidated using chemical techniques. The variety of chemical procedures and techniques which have been developed for the study of heavy-ion reactions and their products has been examined. The determination of the chemical properties of the transmendelevium elements, which are very short-lived and can only be produced an ''atom at a time'' via heavy-ion reactions, is discussed. (author)

  18. Forest products decomposition in municipal solid waste landfills

    International Nuclear Information System (INIS)

    Barlaz, Morton A.

    2006-01-01

    Cellulose and hemicellulose are present in paper and wood products and are the dominant biodegradable polymers in municipal waste. While their conversion to methane in landfills is well documented, there is little information on the rate and extent of decomposition of individual waste components, particularly under field conditions. Such information is important for the landfill carbon balance as methane is a greenhouse gas that may be recovered and converted to a CO 2 -neutral source of energy, while non-degraded cellulose and hemicellulose are sequestered. This paper presents a critical review of research on the decomposition of cellulosic wastes in landfills and identifies additional work that is needed to quantify the ultimate extent of decomposition of individual waste components. Cellulose to lignin ratios as low as 0.01-0.02 have been measured for well decomposed refuse, with corresponding lignin concentrations of over 80% due to the depletion of cellulose and resulting enrichment of lignin. Only a few studies have even tried to address the decomposition of specific waste components at field-scale. Long-term controlled field experiments with supporting laboratory work will be required to measure the ultimate extent of decomposition of individual waste components

  19. Synthesis and Characterization of Co (OH)2 Nanorods by Solid-state Chemical Reaction at Room Temperature%氢氧化钴纳米棒的室温固相化学合成及其表征

    Institute of Scientific and Technical Information of China (English)

    贾殿赠; 曹亚丽; 刘浪; 周杰; 肖定全

    2005-01-01

    Cobahous hydroxide nanorods were synthesized by solid-state chemical reactions of Co(Ac)2·4H2O, and NaOH at room temperature in the presence of polyethylene glycol 400 (PEG-400). The compositions and morphologies of the products were characterized by XRD, TEM, IR and TG-DTA. The results show that Co(OH)2 nanorods can be obtained only in one-step by means of surfactant-assisted soft-template solid-state chemical reaction method. The surfactant (PEG-400) plays a soft-template like role in the process of Co(OH)2 nanorods formation and leads nanocrystallines to grow along certain direction into nanorods.

  20. Dilepton and vector meson production in heavy-ion reactions

    International Nuclear Information System (INIS)

    Wolf, Gy.

    1997-01-01

    A nonperturbative dynamical study of dilepton an vector meson production in heavy-ion collisions from 1 to 2 GeV/A bombarding energies is presented incorporating all known sources relevant in this energy range. The dynamical evolution of the nucleus-nucleus collision is described by a transport equation of the Boltzmann-Uehling-Uhlenbeck type evolving phase-space distribution functions for nucleons, baryon resonances, pions, η's, ρ's and σ's with their isospin degrees of freedom. In particular, the sensitivity of the calculated yields to predicted changes of the ρ and ω mesons in dense matter is investigated. (author)

  1. The Phase Behavior Effect on the Reaction Engineering of Transesterification Reactions and Reactor Design for Continuous Biodiesel Production

    Science.gov (United States)

    Csernica, Stephen N.

    transitions from two phases to a single phase, or pseudo-single phase. The transition to a single phase or pseudo-single phase is a function of the methanol content. Regardless, the maximum observed reaction rate occurs at the point of the phase transition, when the concentration of triglycerides in the methanol phase is largest. The phase transition occurs due to the accumulation of the primary product, biodiesel methyl esters. Through various experiments, it was determined that the rate of the triglyceride mass transfer into the methanol phase, as well as the solubility of triglycerides in methanol, increases with increasing methyl ester concentration. Thus, there exists some critical methyl ester concentration which favors the formation of a single or pseudo-single phase system. The effect of the by-product glycerol on the reaction kinetics was also investigated. It was determined that at low methanol to triglyceride molar ratios, glycerol acts to inhibit the reaction rate and limit the overall triglyceride conversion. This occurs because glycerol accumulates in the methanol phase, i.e. the primary reaction volume. When glycerol is at relatively high concentrations within the methanol phase, triglycerides become excluded from the reaction volume. This greatly reduces the reaction rate and limits the overall conversion. As the concentration of methanol is increased, glycerol becomes diluted and the inhibitory effects become dampened. Assuming pseudo-homogeneous phase behavior, a simple kinetic model incorporating the inhibitory effects of glycerol was proposed based on batch reactor data. The kinetic model was primarily used to theoretically compare the performance of different types of continuous flow reactors for continuous biodiesel production. It was determined that the inhibitory effects of glycerol result in the requirement of very large reactor volumes when using continuous stirred tank reactors (CSTR). The reactor volume can be greatly reduced using tubular style

  2. Optimization of Laccase Production using White Rot Fungi and Agriculture Wastes in Solid State Fermentation

    Directory of Open Access Journals (Sweden)

    Hendro Risdianto

    2012-07-01

    Full Text Available Laccase has been produced in a solid state fermentation (SSF using white rot fungi and various lignocellulosic based substrates. White rot fungi used were Marasmius sp, Trametes hirsuta, Trametes versicolor and Phanerochaete crysosporium. The solid substrates employed in this research were collected from agriculture waste which were empty fruit bunches (EFB, rice straw, corn cob, and rice husk. The objective of this research was to determine the most promising fungus, the best solid substrate and the optimal conditions for the production of laccase. The results showed that Marasmius sp. on all solid substrates displayed higher laccase activity than that of any other strain of white rot fungi. Marasmius sp. and solid substrate of rice straw demonstrated the highest laccase activity of 1116.11 U/L on day 10. Three significant factors, i.e. pH, temperature and yeast extract concentration were studied by response surface method on laccase production using Marasmius sp and rice straw. The optimized conditions were pH, temperature and yeast extract concentration of 4.9, 31ºC and 0.36 g/L respectively. The fermentation of Marasmius sp. in SSF on agricultural waste shows a great potential for the production of laccase.

  3. Catalytic Upgrading of Bio-Oil by Reacting with Olefins and Alcohols over Solid Acids: Reaction Paths via Model Compound Studies

    Directory of Open Access Journals (Sweden)

    Qingwen Wang

    2013-03-01

    Full Text Available Catalytic refining of bio-oil by reacting with olefin/alcohol over solid acids can convert bio-oil to oxygen-containing fuels. Reactivities of groups of compounds typically present in bio-oil with 1-octene (or 1-butanol were studied at 120 °C/3 h over Dowex50WX2, Amberlyst15, Amberlyst36, silica sulfuric acid (SSA and Cs2.5H0.5PW12O40 supported on K10 clay (Cs2.5/K10, 30 wt. %. These compounds include phenol, water, acetic acid, acetaldehyde, hydroxyacetone, d-glucose and 2-hydroxymethylfuran. Mechanisms for the overall conversions were proposed. Other olefins (1,7-octadiene, cyclohexene, and 2,4,4-trimethylpentene and alcohols (iso-butanol with different activities were also investigated. All the olefins and alcohols used were effective but produced varying product selectivities. A complex model bio-oil, synthesized by mixing all the above-stated model compounds, was refined under similar conditions to test the catalyst’s activity. SSA shows the highest hydrothermal stability. Cs2.5/K10 lost most of its activity. A global reaction pathway is outlined. Simultaneous and competing esterification, etherfication, acetal formation, hydration, isomerization and other equilibria were involved. Synergistic interactions among reactants and products were determined. Acid-catalyzed olefin hydration removed water and drove the esterification and acetal formation equilibria toward ester and acetal products.

  4. Experimental investigation of solid sodium-water reaction: tests results and phenomenological analysis

    International Nuclear Information System (INIS)

    Daudin, K.; Beauchamp, F.; Proust, C.

    2014-01-01

    Sodium-Water Reaction (SWR) is an issue one has to be capable to deal with for the next generation of nuclear reactors (SFR for GEN IV). The background of these experiments is the improvement of safety demonstration regarding SWR in an open volume. This experimental campaign is conducted at the CEA Cadarache inside a cylindrical reactor filled with inert gas. The sodium is inside a loading pot and water comes into contact by immersion. SWR and its physical effects are followed by different pressure and temperature sensors. The results show a limit to the overpressure increasing sodium mass. Global assessment of physical effects of SWR contributes to put forward the relative nature of phenomena with geometric configuration, and the importance of scale effects. (authors)

  5. Determination of gamma production from (n, gamma) reactions

    International Nuclear Information System (INIS)

    Kostal, M.

    2007-06-01

    Calculation of gamma production by interaction of neutrons with materials requires a reasonable accuracy of the nuclear libraries, i. e. effective cross sections, nuclear levels and probabilities of transitions between them. Accurate data enable accurate calculations to be performed, e.g. for PGNAA. First, gamma production in a thick 56 Fe target was examined. Appreciable discrepancies were found among the nuclear libraries available. Additional calculations were performed and compared with the observed data. The fluence of photons observed behind a thick iron target was investigated, the target being irradiated with neutrons from the front side. The results were evaluated for the various nuclear libraries. It is concluded that the libraries ENDF/B VI.2., i.e. data embedded in the MCNPX code, are sufficient for a number of applications. However, their accuracy is insufficient for prompt gamma neutron activation analysis. This is also true of data from the libraries JEFF 3.1. a JENDL 3.3, so that other libraries will have to be used for PGNAA. Specifically for 56 Fe, the data from the libraries ENDF/B VII.0 seem to be usable. (P.A.)

  6. Synthesis of Cubic Phase-Co Microspheres by Mechanical Solid-State Reaction-Thermal Decomposition and Research on Its Growth Kinetics

    Directory of Open Access Journals (Sweden)

    Ying Deng

    2016-01-01

    Full Text Available Cubic phase cobalt (Co, which can be used as a key component for composite materials given its excellent ductility and internal structure, is not easy to obtain at room temperature. In this study, oxalic acid and cobalt nitrate are used as raw materials to synthesize the cobalt oxalate precursor, which has a stable structure with a five-membered chelate ring. Cobalt oxalate microspheres, having a high internal energy content, were prepared by using mechanical solid-state reaction in the presence of a surfactant, which can produce spherical micelles. The thermal decomposition of the precursor was carried out by maintaining it in a nitrogen atmosphere at 450°C for 3 h. At the end of the procedure, 100 nm cubic phase-Co microspheres, stable at room temperature, were obtained. Isothermal and nonisothermal kinetic mechanisms of cobalt grain growth were investigated. The cubic-Co grain growth activation energy, Q, was calculated in this study to be 71.47 kJ/mol. The required reaction temperature was low, making the production process simple and suitable for industrial applications.

  7. Microstructure and growth kinetics of nickel silicide ultra-thin films synthesized by solid-state reactions

    Science.gov (United States)

    Coia, Cedrik

    The objective of the thesis is to develop a detailed fundamental understanding of the thermally induced solid-state reactions that lead to the formation of the NiSi. We use in situ synchrotron x-ray diffraction as well as wafer curvature measurements to monitor reactions as they occur during the annealing treatment. These analyses are complemented by ex situ transmission electron microscopy, Rutherford backscattering spectroscopy, and secondary ions mass spectroscopy. The solid-state reactions between 4 to 500 nm-thick Ni films and Si (001) are considerably more complex than previously believed. In addition to the commonly observed phases listed above, we observe the formation of three additional compounds---θ-Ni2Si, Ni31Si12 and Ni3Si2---before the complete transformation of the reacted film into NiSi. These compounds are found to co-exist laterally (within the same layer) with delta-Ni2Si and/or NiSi. The metastable compound θ-Ni2Si, which formation results from texture inheritance and rapid growth through vacancy diffusion, is present in all samples and forms at the same temperature (300+/-10°C) regardless of the initial Ni thickness. Indeed, this compound forms rapidly during ramps anneals, apparently consuming all the delta-Ni2Si for initial Ni films thickness of up to 10 nm. Its disappearance is also rapid and is correlated to both the growth of NiSi and to a surprising return of the orthorhombic delta-Ni 2Si. The formation sequence is therefore not monotonic in composition in contrast to what is usually expected in solid-state reactions. An investigation of the effect of alloying elements (Pt and Co) and impurities (B, P, As, F, N) on the Ni-Si reactions enables us to determine that nucleation plays a limiting role in the growth of metastable θ-Ni2Si and that the template provided by delta-Ni2Si is crucial in promoting this nucleation. Furthermore, reactions with amorphized and amorphous substrates indicate that the possibility of epitaxy with the Si

  8. 40 CFR 721.6181 - Fatty acid, reaction product with substituted oxirane, formaldehyde-phenol polymer glycidyl ether...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Fatty acid, reaction product with... Specific Chemical Substances § 721.6181 Fatty acid, reaction product with substituted oxirane, formaldehyde... as fatty acid, reaction product with substituted oxirane, formaldehyde-phenol polymer glycidyl ether...

  9. Projectile like fragment production in Ar induced reactions around the Fermi energy

    International Nuclear Information System (INIS)

    Borrel, V.; Gatty, B.; Jacquet, D.; Galin, J.

    1986-01-01

    The production of projectile like fragments (PLF) has been studied in Ar induced reactions on various targets. It shows very clearly, that besides the predominance of fragmentation for most of the products, the transfer process is still a very strong component for products nearby the projectile. The influence of the target neutron excess on the PLF production is investigated as well as the evolution with incident energy of the characteristics of the different competing processes

  10. Operando Solid-State NMR Observation of Solvent-Mediated Adsorption-Reaction of Carbohydrates in Zeolites

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Long; Alamillo, Ricardo; Elliott, William A.; Andersen, Amity; Hoyt, David W.; Walter, Eric D.; Han, Kee Sung; Washton, Nancy M.; Rioux, Robert M.; Dumesic, James A.; Scott, Susannah L.

    2017-04-18

    Liquid-phase processing of molecules using heterogeneous catalysts – an important strategy for obtaining renewable chemicals sustainably from biomass – involves reactions that occur at solid-liquid interfaces. In glucose isomerization catalyzed by basic faujasite zeolites, the catalytic activity depends strongly on the solvent composition: initially, it declines precipitously when water is mixed with a small amount of the organic co-solvent γ-valerolactone (GVL), then recovers as the GVL content increases. Using solid-state 13C NMR spectroscopy, we observed glucose isomers located inside the zeolite pores directly, and followed their transformations into fructose and mannose in real time. At low GVL concentrations, glucose is depleted in the zeolite pores relative to the liquid phase, while higher GVL concentrations in solution drive glucose inside the pores, resulting in up to a 32 enhancement in the local glucose concentration. Although their populations exchange rapidly, molecules present at the reactive interface experience a significantly different environment from the bulk solution.

  11. Synthesis of monoclinic Celsian from Coal Fly Ash by using a one-step solid-state reaction process

    Energy Technology Data Exchange (ETDEWEB)

    Long-Gonzalez, D.; Lopez-Cuevas, J.; Gutierrez-Chavarria, C.A.; Pena, P.; Baudin, C.; Turrillas, X. [CINVESTAV, Coahuila (Mexico)

    2010-03-15

    Monoclinic (Celsian) and hexagonal (Hexacelsian) Ba1-xSrxAl{sub 2}Si2O8 solid solutions, where x=0, 0.25, 0.375, 0.5, 0.75 or 1, were synthesized by using Coal Fly Ash (CFA) as main raw material, employing a simple one-step solid-state reaction process involving thermal treatment for 5 h at 850-1300{sup o}C. Fully monoclinic Celsian was obtained at 1200{sup o} C/5 h, for SrO contents of 0.25 {<=} x {<=} 0.75. However, an optimum SrO level of 0.25 {<=} x {<=} 0.375 was recommended for the stabilization of Celsian. These synthesis conditions represent a significant improvement over the higher temperatures, longer times and/or multi-step processes needed to obtain fully monoclinic Celsian, when other raw materials are used for this purpose, according to previous literature. These results were attributed to the role of the chemical and phase constitution of CFA as well as to a likely mineralizing effect of CaO and TiO{sub 2} present in it, which enhanced the Hexacelsian to Celsian conversion.

  12. Effect of Degassing Treatment on the Interfacial Reaction of Molten Aluminum and Solid Steel

    Directory of Open Access Journals (Sweden)

    Triyono T.

    2017-06-01

    Full Text Available The gas porosity is one of the most serious problems in the casting of aluminum. There are several degassing methods that have been studied. During smelting of aluminum, the intermetallic compound (IMC may be formed at the interface between molten aluminum and solid steel of crucible furnace lining. In this study, the effect of degassing treatment on the formations of IMC has been investigated. The rectangular substrate specimens were immersed in a molten aluminum bath. The holding times of the substrate immersions were in the range from 300 s to 1500 s. Two degassing treatments, argon degassing and hexachloroethane tablet degassing, were conducted to investigate their effect on the IMC formation. The IMC was examined under scanning electron microscope with EDX attachment. The thickness of the IMC layer increased with increasing immersion time for all treatments. Due to the high content of hydrogen, substrate specimens immersed in molten aluminum without degasser had IMC layer which was thicker than others. Argon degassing treatment was more effective than tablet degassing to reduce the IMC growth. Furthermore, the hard and brittle phase of IMC, FeAl3, was formed dominantly in specimens immersed for 900 s without degasser while in argon and tablet degasser specimens, it was formed partially.

  13. GC of catalytic reactions products involved in the promising fuel synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Zheivot, V.; Sazonova, N. [Russian Academy of Sciences, Novosibirsk (Russian Federation). Boreskov Inst. of Catalysis

    2012-09-15

    Catalytic reactions involved in the synthesis of the promising kinds of novel fuel and products formed in these reactions were systematized according to the resulting fuel type. Generalization of the retention of the substances comprising these products is presented. Chromatograms exhibiting their separation on chromatographic materials with the surface of different chemical properties are summarized. We propose procedures for gas-chromatographic analysis of the catalytic reactions products formed in the synthesis of hydrogen, methanol, dimethyl ether and hydrocarbons as a new generation of fuel alternative to petroleum and coal. For partial oxidation of methane into synthesis gas, on-line determination of the components obtained in the reaction was carried out by gas chromatography and gas analyzer based on different physicochemical methods (IR spectroscopy and electrochemical methods). Similarity of the results obtained using these methods is demonstrated. (orig.)

  14. Modelling of different enzyme productions by solid-state fermentation on several agro-industrial residues.

    Science.gov (United States)

    Diaz, Ana Belen; Blandino, Ana; Webb, Colin; Caro, Ildefonso

    2016-11-01

    A simple kinetic model, with only three fitting parameters, for several enzyme productions in Petri dishes by solid-state fermentation is proposed in this paper, which may be a valuable tool for simulation of this type of processes. Basically, the model is able to predict temporal fungal enzyme production by solid-state fermentation on complex substrates, maximum enzyme activity expected and time at which these maxima are reached. In this work, several fermentations in solid state were performed in Petri dishes, using four filamentous fungi grown on different agro-industrial residues, measuring xylanase, exo-polygalacturonase, cellulose and laccase activities over time. Regression coefficients after fitting experimental data to the proposed model turned out to be quite high in all cases. In fact, these results are very interesting considering, on the one hand, the simplicity of the model and, on the other hand, that enzyme activities correspond to different enzymes, produced by different fungi on different substrates.

  15. Perspectives of advanced thermal management in solar thermochemical syngas production using a counter-flow solid-solid heat exchanger

    Science.gov (United States)

    Falter, Christoph; Sizmann, Andreas; Pitz-Paal, Robert

    2017-06-01

    A modular reactor model is presented for the description of solar thermochemical syngas production involving counter-flow heat exchangers that recuperate heat from the solid phase. The development of the model is described including heat diffusion within the reactive material as it travels through the heat exchanger, which was previously identified to be a possibly limiting factor in heat exchanger design. Heat transfer within the reactive medium is described by conduction and radiation, where the former is modeled with the three-resistor model and the latter with the Rosseland diffusion approximation. The applicability of the model is shown by the analysis of heat exchanger efficiency for different material thicknesses and porosities in a system with 8 chambers and oxidation and reduction temperatures of 1000 K and 1800 K, respectively. Heat exchanger efficiency is found to rise strongly for a reduction of material thickness, as the element mass is reduced and a larger part of the elements takes part in the heat exchange process. An increase of porosity enhances radiation heat exchange but deteriorates conduction. The overall heat exchange in the material is improved for high temperatures in the heat exchanger, as radiation dominates the energy transfer. The model is shown to be a valuable tool for the development and analysis of solar thermochemical reactor concepts involving heat exchange from the solid phase.

  16. Cultivation and Characterization of Cynara Cardunculus for Solid Biofuels Production in the Mediterranean Region

    Directory of Open Access Journals (Sweden)

    Nicholas G. Danalatos

    2008-07-01

    Full Text Available Technical specifications of solid biofuels are continuously improved towards the development and promotion of their market. Efforts in the Greek market are limited, mainly due to the climate particularity of the region, which hinders the growth of suitable biofuels. Taking also into account the increased oil prices and the high inputs required to grow most annual crops in Greece, cardoon (Cynara cardunculus L. is now considered the most important and promising sources for solid biofuel production in Greece in the immediate future. The reason is that cardoon is a perennial crop of Mediterranean origin, well adapted to the xerothermic conditions of southern Europe, which can be utilized particularly for solid biofuel production. This is due to its minimum production cost, as this perennial weed may perform high biomass productivity on most soils with modest or without any inputs of irrigation and agrochemicals. Within this framework, the present research work is focused on the planning and analysis of different land use scenarios involving this specific energy crop and the combustion behaviour characterization for the solid products. Such land use scenarios are based on quantitative estimates of the crop’s production potential under specific soil-climatic conditions as well as the inputs required for its realization in comparison to existing conventional crops. Concerning its decomposition behaviour, devolatilisation and char combustion tests were performed in a non-isothermal thermogravimetric analyser (TA Q600. A kinetic analysis was applied and accrued results were compared with data already available for other lignocellulosic materials. The thermogravimetric analysis showed that the decomposition process of cardoon follows the degradation of other lignocellulosic fuels, meeting high burnout rates. This research work concludes that Cynara cardunculus, under certain circumstances, can be used as a solid biofuel of acceptable quality.

  17. A batch assay to measure microbial hydrogen sulfide production from sulfur-containing solid wastes

    International Nuclear Information System (INIS)

    Sun, Mei; Sun, Wenjie; Barlaz, Morton A.

    2016-01-01

    Large volumes of sulfur-containing wastes enter municipal solid waste landfills each year. Under the anaerobic conditions that prevail in landfills, oxidized forms of sulfur, primarily sulfate, are converted to sulfide. Hydrogen sulfide (H 2 S) is corrosive to landfill gas collection and treatment systems, and its presence in landfill gas often necessitates the installation of expensive removal systems. For landfill operators to understand the cost of managing sulfur-containing wastes, an estimate of the H 2 S production potential is needed. The objective of this study was to develop and demonstrate a biochemical sulfide potential (BSP) test to measure the amount of H 2 S produced by different types of sulfur-containing wastes in a relatively fast (30 days) and inexpensive (125 mL serum bottles) batch assay. This study confirmed the toxic effect of H 2 S on both sulfate reduction and methane production in batch systems, and demonstrated that removing accumulated H 2 S by base adsorption was effective for mitigating inhibition. H 2 S production potentials of coal combustion fly ash, flue gas desulfurization residual, municipal solid waste combustion ash, and construction and demolition waste were determined in BSP assays. After 30 days of incubation, most of the sulfate in the wastes was converted to gaseous or aqueous phase sulfide, with BSPs ranging from 0.8 to 58.8 mL H 2 S/g waste, depending on the chemical composition of the samples. Selected samples contained solid phase sulfide which contributed to the measured H 2 S yield. A 60 day incubation in selected samples resulted in 39–86% additional sulfide production. H 2 S production measured in BSP assays was compared with that measured in simulated landfill reactors and that calculated from chemical analyses. H 2 S production in BSP assays and in reactors was lower than the stoichiometric values calculated from chemical composition for all wastes tested, demonstrating the importance of assays to estimate the

  18. A batch assay to measure microbial hydrogen sulfide production from sulfur-containing solid wastes

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Mei, E-mail: msun8@uncc.edu [Department of Civil, Construction, and Environmental Engineering, North Carolina State University, Campus Box 7908, Raleigh, NC (United States); Sun, Wenjie, E-mail: wsun@smu.edu [Department of Civil, Construction, and Environmental Engineering, North Carolina State University, Campus Box 7908, Raleigh, NC (United States); Department of Civil and Environmental Engineering, Southern Methodist University, PO Box 750340, Dallas, TX (United States); Barlaz, Morton A., E-mail: barlaz@ncsu.edu [Department of Civil, Construction, and Environmental Engineering, North Carolina State University, Campus Box 7908, Raleigh, NC (United States)

    2016-05-01

    Large volumes of sulfur-containing wastes enter municipal solid waste landfills each year. Under the anaerobic conditions that prevail in landfills, oxidized forms of sulfur, primarily sulfate, are converted to sulfide. Hydrogen sulfide (H{sub 2}S) is corrosive to landfill gas collection and treatment systems, and its presence in landfill gas often necessitates the installation of expensive removal systems. For landfill operators to understand the cost of managing sulfur-containing wastes, an estimate of the H{sub 2}S production potential is needed. The objective of this study was to develop and demonstrate a biochemical sulfide potential (BSP) test to measure the amount of H{sub 2}S produced by different types of sulfur-containing wastes in a relatively fast (30 days) and inexpensive (125 mL serum bottles) batch assay. This study confirmed the toxic effect of H{sub 2}S on both sulfate reduction and methane production in batch systems, and demonstrated that removing accumulated H{sub 2}S by base adsorption was effective for mitigating inhibition. H{sub 2}S production potentials of coal combustion fly ash, flue gas desulfurization residual, municipal solid waste combustion ash, and construction and demolition waste were determined in BSP assays. After 30 days of incubation, most of the sulfate in the wastes was converted to gaseous or aqueous phase sulfide, with BSPs ranging from 0.8 to 58.8 mL H{sub 2}S/g waste, depending on the chemical composition of the samples. Selected samples contained solid phase sulfide which contributed to the measured H{sub 2}S yield. A 60 day incubation in selected samples resulted in 39–86% additional sulfide production. H{sub 2}S production measured in BSP assays was compared with that measured in simulated landfill reactors and that calculated from chemical analyses. H{sub 2}S production in BSP assays and in reactors was lower than the stoichiometric values calculated from chemical composition for all wastes tested, demonstrating

  19. Graphite Carbon-Supported Mo2C Nanocomposites by a Single-Step Solid State Reaction for Electrochemical Oxygen Reduction.

    Science.gov (United States)

    Huang, K; Bi, K; Liang, C; Lin, S; Wang, W J; Yang, T Z; Liu, J; Zhang, R; Fan, D Y; Wang, Y G; Lei, M

    2015-01-01

    Novel graphite-molybdenum carbide nanocomposites (G-Mo2C) are synthesized by a typical solid state reaction with melamine and MoO3 as precursors under inert atmosphere. The characterization results indicate that G-Mo2C composites are composed of high crystallization and purity of Mo2C and few layers of graphite carbon. Mo2C nanoparticles with sizes ranging from 5 to 50 nm are uniformly supported by surrounding graphite layers. It is believed that Mo atom resulting from the reduction of MoO3 is beneficial to the immobilization of graphite carbon. Moreover, the electrocatalytic performances of G-Mo2C for ORR in alkaline medium are investigated by cyclic voltammetry (CV), rotating disk electrode (RDE) and chronoamperometry test with 3M methanol. The results show that G-Mo2C has a considerable catalytic activity and superior methanol tolerance performance for the oxygen reduction reaction (ORR) benefiting from the chemical interaction between the carbide nanoparticles and graphite carbon.

  20. Implications of Industrial Processing Strategy on Cellulosic Ethanol Production at High Solids Concentrations

    DEFF Research Database (Denmark)

    Cannella, David

    The production of cellulosic ethanol is a biochemical process of not edible biomasses which contain the cellulose. The process involves the use of enzymes to hydrolyze the cellulose in fermentable sugars to finally produce ethanol via fermentative microorganisms (i.e. yeasts). These biomasses...... are the leftover of agricultural productions (straws), not edible crops (giant reed) or wood, thus the ethanol so produced is also called second generation (or 2G ethanol), which differs from the first generation produced from starch (sugar beets mostly). In the industrial production of cellulosic ethanol high...... solids strategy resulted critical for its cost effectiveness: high concentration of initial biomass it will lead to high concentration of the final product (ethanol), thus more convenient to isolate. This thesis investigate the implementation of a high solids loading concept into cellulosic ethanol...

  1. Dispersive solid-phase imprinting of proteins for the production of plastic antibodies

    DEFF Research Database (Denmark)

    Ashley, Jon; Feng, Xiaotong; Halder, Arnab

    2018-01-01

    We describe a novel dispersive solid-phase imprinting technique for the production of nano-sized molecularly imprinted polymers (nanoMIPs) as plastic antibodies. The template was immobilized on in-house synthesized magnetic microspheres instead of conventional glass beads. As a result, high...

  2. Fungal pretreatment of albizia chips for enhanced biogas production by solid-state anaerobic digestion

    Science.gov (United States)

    Albizia biomass is a forestry waste, and holds a great potential in biogas production by solid-state anaerobic digestion (SS-AD). However, low methane yields from albizia chips were observed due to their recalcitrant structure. In this study, albizia chips were pretreated by Ceriporiopsis subvermisp...

  3. Growth and lipid production of Umbelopsis isabellina on a solid substrate - Mechanistic modeling and validation

    NARCIS (Netherlands)

    Meeuwse, P.; Klok, A.J.; Haemers, S.; Tramper, J.; Rinzema, A.

    2012-01-01

    Microbial lipids are an interesting feedstock for biodiesel. Their production from agricultural waste streams by fungi cultivated in solid-state fermentation may be attractive, but the yield of this process is still quite low. In this article, a mechanistic model is presented that describes growth,

  4. Production and partial characterisation of feruloyl esterase by Sporotrichum thermophile in solid-state fermentation

    DEFF Research Database (Denmark)

    Topakas, E.; Kalogeris, E.; Kekos, D.

    2003-01-01

    A number of factors affecting production of feruloyl esterase an enzyme that hydrolyse ester linkages of ferulic acid (FA) in plant cell walls, by the thermophylic fungus Sporotrichum thermophile under solid state fermentation (SSF) were investigated. Initial moisture content and type of carbon...

  5. Two-stage medium chain fatty acid (MCFA) production from municipal solid waste and ethanol

    NARCIS (Netherlands)

    Grootscholten, T.I.M.; Strik, D.P.B.T.B.; Steinbusch, K.J.J.; Buisman, C.J.N.; Hamelers, B.

    2014-01-01

    Chain elongation is an anaerobic fermentation that produces medium chain fatty acids (MCFAs) from volatile fatty acids and ethanol. These MCFAs can be used as biochemical building blocks for fuel production and other chemical processes. Producing MCFAs from the organic fraction of municipal solid

  6. Managing plastic waste in East Africa: Niche innovations in plastic production and solid waste

    NARCIS (Netherlands)

    Ombis, L.O.; Vliet, van B.J.M.; Mol, A.P.J.

    2015-01-01

    This paper assesses the uptake of environmental innovation practices to cope with plastic waste in Kenyan urban centres at the interface of solid waste management and plastic production systems. The Multi Level Perspective on Technological Transitions is used to evaluate 7 innovation pathways of

  7. Petrographic and mineral characterization of Balkan coals and their solid waste products from coal preparation

    International Nuclear Information System (INIS)

    Yossifova, M.

    1995-01-01

    This paper is part of a complex petrographic, mineralogical and chemical investigation on Balkan bituminous coals and their solid waste products from coal preparation. The petrographic and phase-mineralogical composition in ten composite samples and four water extracts have been studied by optical microscopy, scanning electron microscopy and X-ray diffraction. 4 refs., 4 tabs

  8. Characterizations of self-combustion reactions (SCR) for the production of nanomaterials used as advanced cathodes in Li-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Haik, Ortal; Martha, Surendra K.; Sclar, Hadar; Samuk-Fromovich, Zvi; Zinigrad, Ella; Markovsky, Boris [Department of Chemistry, Bar-Ilan University, Ramat-Gan 52900 (Israel); Kovacheva, Daniela; Saliyski, Nikolay [Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Sofia (Bulgaria); Aurbach, Doron, E-mail: aurbach@mail.biu.ac.il [Department of Chemistry, Bar-Ilan University, Ramat-Gan 52900 (Israel)

    2009-09-10

    In this work, self-combustion reactions (SCR) for the preparation of important cathode materials for rechargeable Li-ion batteries were investigated by thermal analytical tools (DSC, ARC, TGA), electron microscopy, XRD, various spectroscopies (MS, Raman, FTIR) and elemental analysis by ICP. The systems studied include solutions containing metal nitrates at the right stoichiometry and sucrose as a fuel, for the preparation of LiMn{sub 0.5}Ni{sub 0.5}O{sub 2} (layered), LiMn{sub 1.5}Ni{sub 0.5}O{sub 4} (spinel), LiMn{sub 0.33}Ni{sub 0.33}Co{sub 0.33}O{sub 2} (layered), and LiMn{sub 0.4}Ni{sub 0.4}Co{sub 0.2}O{sub 2} (layered). Similar products, which do not depend on the atmosphere of the processes (air or inert) were obtained by spontaneous SCR and the gradual heating of the same solutions by DSC, ARC, and TGA. The reactions involve the partial caramelization of sucrose, complicated by red-ox reactions with the nitrates that form solid products, whose organic part is finally decomposed around 400 {sup o}C. The presence of cobalt ions has a stabilizing effect, which is expressed by the low dissolution rates of Li ions from the solid products thus formed, into aqueous solutions. The reaction mechanisms are discussed herein.

  9. Life Time Performance Characterization of Solid Oxide Electrolysis Cells for Hydrogen Production

    DEFF Research Database (Denmark)

    Sun, Xiufu; Chen, Ming; Liu, Yi-Lin

    2015-01-01

    Solid oxide electrolysis cells (SOECs) offer a promising technological solution for efficient energy conversion and production of hydrogen or syngas. The commercialization of the SOEC technology can be promoted if SOECs can be operated at high current density with stable performance over ~5 years...... - 3 years (continuous operation, setting 1.5 V as the upper voltage defining “end of life”). The results provide technological input to future design of electrolysis plants for hydrogen production. © 2015 ECS - The Electrochemical Society...

  10. Growth evaluation of Lentinula edodes in solid medium cultures for mycelium production as inoculum

    OpenAIRE

    Villegas E Valeska; Pérez Ana Milena; Arredondo Clara

    2007-01-01

    Shitake (Lentinula edodes) Pegler jumbo strain growth was evaluated in different solid mediums and growth substrates for spawn production. Mycelium growth was tested in three culture mediums (MYA, OMYA, PDYA) at two pHs (5, 5.5), using two eucalyptus sawdust percentages (0.3%, 0.2%). Analysing variance revealed significant differences in culture medium (P0.05). The liquid inoculation technique was used for evaluating mushroom spawn production using five different combinations of eucalyptus sa...

  11. Limonene ozonolysis in the presence of nitric oxide: Gas-phase reaction products and yields

    Science.gov (United States)

    Ham, Jason E.; Harrison, Joel C.; Jackson, Stephen R.; Wells, J. R.

    2016-05-01

    The reaction products from limonene ozonolysis were investigated using the new carbonyl derivatization agent, O-tert-butylhydroxylamine hydrochloride (TBOX). With ozone (O3) as the limiting reagent, five carbonyl compounds were detected. The yields of the carbonyl compounds are discussed with and without the presence of a hydroxyl radical (OHrad) scavenger, giving insight into the influence secondary OH radicals have on limonene ozonolysis products. The observed reaction product yields for limonaketone (LimaKet), 7-hydroxyl-6-oxo-3-(prop-1-en-2-yl)heptanal (7H6O), and 2-acetyl-5-oxohexanal (2A5O) were unchanged suggesting OHrad generated by the limonene + O3 reaction does not contribute to their formation. The molar yields of 3-isopropenyl-6-oxo-heptanal (IPOH) and 3-acetyl-6-oxoheptanal (3A6O) decreased by 68% and >95%; respectively, when OHrad was removed. This suggests that OHrad radicals significantly impact the formation of these products. Nitric oxide (NO) did not significantly affect the molar yields of limonaketone or IPOH. However, NO (20 ppb) considerably decreased the molar reaction product yields of 7H6O (62%), 2A5O (63%), and 3A6O (47%), suggesting NO reacted with peroxyl intermediates, generated during limonene ozonolysis, to form other carbonyls (not detected) or organic nitrates. These studies give insight into the transformation of limonene and its reaction products that can lead to indoor exposures.

  12. Flow-injection determination of total organic fluorine with off-line defluorination reaction on a solid sorbent bed.

    Science.gov (United States)

    Musijowski, Jacek; Trojanowicz, Marek; Szostek, Bogdan; da Costa Lima, José Luis Fontes; Lapa, Rui; Yamashita, Hiroki; Takayanagi, Toshio; Motomizu, Shoji

    2007-09-26

    Considering recent reports on widespread occurrence and concerns about perfluoroalkyl substances (PFAS) in environmental and biological systems, analysis of these compounds have gained much attention in recent years. Majority of analyte-specific methods are based on a LC/MS/MS or a GC/MS detection, however many environmental or biological studies would benefit from a total organic fluorine (TOF) determination. Presented work was aimed at developing a method for TOF determination. TOF is determined as an amount of inorganic fluoride obtained after defluorination reaction conducted off-line using sodium biphenyl reagent directly on the sorbent without elution of retained analytes. Recovered fluoride was analyzed using flow-injection system with either fluorimetric or potentiometric detection. The TOF method was tested using perfluorocarboxylic acids (PFCA), including perfluorooctanoic acid (PFOA), as model compounds. Considering low concentrations of PFAS in natural samples, solid-phase extraction as a preconcentration procedure was evaluated. Several carbon-based sorbents were tested, namely multi-wall carbon nanotubes, carbon nanofibres and activated carbon. Good sorption of all analytes was achieved and defluorination reaction was possible to carry out directly on a sorbent bed. Recoveries obtained for PFCAs, adsorbed on an activated carbon sorbent, and measured as TOF, were 99.5+/-1.7, 110+/-9.4, 95+/-26, 120+/-32, 110+/-12 for C4, C6, C8, C10 and C12-PFCA, respectively. Two flow systems that would enable the defluorination reaction and fluoride determination in a single system were designed and tested.

  13. Animal DNA identification in food products and animal feed by real time polymerase chain reaction method

    Directory of Open Access Journals (Sweden)

    Людмила Мар’янівна Іщенко

    2016-11-01

    Full Text Available Approbation of diagnostic tests for species identification of beef, pork and chicken by real time polymerase chain reaction method was done. Meat food, including heat treated and animal feed, was used for research. The fact of inconsistencies was revealed for product composition of some meat products that is marked by manufacturer 

  14. Maillard reaction products of rice protein hydrolysates with mono-, oligo- and polysaccharides

    Science.gov (United States)

    Rice protein, a byproduct of rice syrup production, is abundant but, its lack of functionality prevents its wide use as a food ingredient. Maillard reaction products of (MRPs) hydrolysates from the limited hydrolysis of rice protein (LHRP) and various mono-, oligo- and polysaccharides were evaluat...

  15. Reactions

    DEFF Research Database (Denmark)

    Søndergaard, Morten

    2011-01-01

      My concern is to understand augmentation as an emergent modality - among many others in ‘the expanding digital field' (Søndergaard M. , Transformative Creativity in the Expanded Digital Field, 2009)' - attributed to the production of contemporary art and the ‘archive of knowledge' in the (art) ...

  16. On the angular distributions of the heavy products of (HI, xn) reactions

    International Nuclear Information System (INIS)

    Sagajdak, R.N.

    1989-01-01

    The effects of neutron evaporation and scattering in the target on the angular distribution of the heavy products of (HI, xn) reactions is considered. Based on the analysis of the experimental angular distributions and their calculated parameters a simple phenomenological approach to the description of these distributions is proposed. The calculated distributions are compared with the experimental ones cited in the literature. The possibilities of using the proposed approach to calculate the integrated angular distributions of heavy products and to determine the efficiency of collecting (HI, xn) reaction products under the conditions of the kinematic separation of recoil nuclei are outlined. 28 refs.; 9 figs

  17. BIOGAS PRODUCTION IN DAIRY CATTLE SYSTEMS, USING BATCH DIGESTERS WITH AND WITHOUT SOLIDS SEPARATION IN THE SUBSTRATES

    OpenAIRE

    Anjos, Isis Dos; Toneli, Juliana T. C. L.; Sagula, Alex L.; Lucas Junior, Jorge de

    2017-01-01

    ABSTRACT This research aimed to evaluate the biogas production during the anaerobic biodigestion process of dairy cattle manure, with and without solids separation. Sixteen biodigesters of the batch type were used, each one with 2L of capacity, supplied with manure in four different conditions: (1) pure manure, after washing the floors of the free stall system; (2) manure after the solids separator; (3) manure after the solids separator and sand decanter and (4) manure with the solid retained...

  18. Utilization of solid catfish manure waste as carbon and nutrient source for lactic acid production.

    Science.gov (United States)

    Shi, Suan; Li, Jing; Blersch, David M

    2018-04-19

    The aim of this work was to study the solid waste (manure) produced by catfish as a potential feedstock for the production of lactic acid (LA) via fermentation. The solid waste contains high levels of both carbohydrates and nutrients that are sufficient for LA bacteria. Simultaneous saccharification and co-fermentation (SSCF) was applied using enzyme and Lactobacillus pentosus, and different loadings of enzyme and solid waste were tested. Results showed LA concentrations of 35.7 g/L were obtained at 15% solids content of catfish waste. Because of the high nutrient content in the fish waste, it could also be used as supplementary substrate for nitrogen and carbon sources with other lignocellulosic materials. A combined feedstock of catfish waste and paper mill sludge was tested, increasing the final LA concentration to 43.1 g/L at 12% solids loading. The catfish waste was shown to be a potential feedstock to provide both carbon and nutrients for LA production, suggesting its use as a sole substrate or in combination with other lignocellulosic materials.

  19. Atmospheric reactions of methylcyclohexanes with Cl atoms and OH radicals: determination of rate coefficients and degradation products.

    Science.gov (United States)

    Ballesteros, Bernabé; Ceacero-Vega, Antonio A; Jiménez, Elena; Albaladejo, José

    2015-04-01

    As the result of biogenic and anthropogenic activities, large quantities of chemical compounds are emitted into the troposphere. Alkanes, in general, and cycloalkanes are an important chemical class of hydrocarbons found in diesel, jet and gasoline, vehicle exhaust emissions, and ambient air in urban areas. In general, the primary atmospheric fate of organic compounds in the gas phase is the reaction with hydroxyl radicals (OH). The oxidation by Cl atoms has gained importance in the study of atmospheric reactions because they may exert some influence in the boundary layer, particularly in marine and coastal environments, and in the Arctic troposphere. The aim of this paper is to study of the atmospheric reactivity of methylcylohexanes with Cl atoms and OH radicals under atmospheric conditions (in air at room temperature and pressure). Relative kinetic techniques have been used to determine the rate coefficients for the reaction of Cl atoms and OH radicals with methylcyclohexane, cis-1,4-dimethylcyclohexane, trans-1,4-dimethylcyclohexane, and 1,3,5-trimethylcyclohexane at 298 ± 2 K and 720 ± 5 Torr of air by Fourier transform infrared) spectroscopy and gas chromatography-mass spectrometry (GC-MS) in two atmospheric simulation chambers. The products formed in the reaction under atmospheric conditions were investigated using a 200-L Teflon bag and employing the technique of solid-phase microextraction coupled to a GC-MS. The rate coefficients obtained for the reaction of Cl atoms with the studied compounds are the following ones (in units of 10(-10) cm(3) molecule(-1) s(-1)): (3.11 ± 0.16), (2.89 ± 0.16), (2.89 ± 0.26), and (2.61 ± 0.42), respectively. For the reactions with OH radicals the determined rate coefficients are (in units of 10(-11) cm(3) molecule(-1) s(-1)): (1.18 ± 0.12), (1.49 ± 0.16), (1.41 ± 0.15), and (1.77 ± 0.23), respectively. The reported error is twice the standard deviation. A detailed

  20. Syngas (CO-H2) production using high temperature micro-tubular solid oxide electrolysers

    International Nuclear Information System (INIS)

    Kleiminger, L.; Li, T.; Li, K.; Kelsall, G.H.

    2015-01-01

    Highlights: • CO 2 and/or H 2 O reduced to CO/H 2 in micro-tubular solid oxide electrolyser (MT-SOE). • MT-SOE: CO 2 , H 2 O | Ni-(ZrO 2 ) 0.92 (Y 2 O 3 ) 0.08 (YSZ) | YSZ | YSZ- La 0.8 Sr 0.2 MnO 3-δ |O 2. • −0.76 A cm −2 achieved at 1.5V and ca. 820°C for H 2 O electrolysis. • Ni wire cathode current collector gave better performance than (Ag wire+Ag paste). • C 18 O 2 in co-electrolysis could not distinguish cathodic and chemical reduction. - Abstract: CO 2 and/or H 2 O were reduced to CO/H 2 in micro-tubular solid oxide electrolysers with yttria-stabilized zirconia (YSZ) electrolyte, Ni-YSZ cermet cathode and strontium(II)-doped lanthanum manganite (LSM) oxygen-evolving anode. At 822 °C, the kinetics of CO 2 reduction were slower (ca. −0.49 A cm −2 at 1.8 V) than H 2 O reduction or co-reduction of CO 2 and H 2 O, which were comparable (ca. −0.83 to −0.77 A cm −2 at 1.8 V). Performances were improved (−0.85 and −1.1 A cm −2 for CO 2 and H 2 O electrolysis, respectively) by substituting the silver current collector with nickel and avoiding blockage of entrances to pores on the inner lumen of micro-tubes induced by silver paste applied previously to decrease contact losses. The change in current collector materials increased ohmic potential losses due to substituting the lower resistance Ag with Ni wire, but decreased electrode polarization losses by 80–93%. For co-electrolysis of CO 2 and H 2 O, isotopically-labelled C 18 O 2 was used to try to distinguish between direct cathodic reduction of CO 2 and its Ni-catalysed chemical reaction with hydrogen from reduction of steam. Unfortunately, oxygen was exchanged between C 18 O 2 and H 2 16 O, enriching oxygen-18 in the steam and substituting oxygen-16 in the carbon dioxide, so the anode off-gas isotopic fractions were meaningless. This occurred even in alumina and YSZ tubes without the micro-tubular reactor, i.e. in the absence of Ni catalyst, though not in quartz tubes

  1. Re-fermentation of washed spent solids from batch hydrogenogenic fermentation for additional production of biohydrogen from the organic fraction of municipal solid waste.

    Science.gov (United States)

    Muñoz-Páez, Karla M; Ríos-Leal, Elvira; Valdez-Vazquez, Idania; Rinderknecht-Seijas, Noemí; Poggi-Varaldo, Héctor M

    2012-03-01

    In the first batch solid substrate anaerobic hydrogenogenic fermentation with intermittent venting (SSAHF-IV) of the organic fraction of municipal solid waste (OFMSW), a cumulative production of 16.6 mmol H(2)/reactor was obtained. Releases of hydrogen partial pressure first by intermittent venting and afterward by flushing headspace of reactors with inert gas N(2) allowed for further hydrogen production in a second to fourth incubation cycle, with no new inoculum nor substrate nor inhibitor added. After the fourth cycle, no more H(2) could be harvested. Interestingly, accumulated hydrogen in 4 cycles was 100% higher than that produced in the first cycle alone. At the end of incubation, partial pressure of H(2) was near zero whereas high concentrations of organic acids and solvents remained in the spent solids. So, since approximate mass balances indicated that there was still a moderate amount of biodegradable matter in the spent solids we hypothesized that the organic metabolites imposed some kind of inhibition on further fermentation of digestates. Spent solids were washed to eliminate organic metabolites and they were used in a second SSAHF-IV. Two more cycles of H(2) production were obtained, with a cumulative production of ca. 2.4 mmol H(2)/mini-reactor. As a conclusion, washing of spent solids of a previous SSAHF-IV allowed for an increase of hydrogen production by 15% in a second run of SSAHF-IV, leading to the validation of our hypothesis. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Understanding the mechanisms of solid-water reactions through analysis of surface topography.

    Science.gov (United States)

    Bandstra, Joel Z; Brantley, Susan L

    2015-12-01

    The topography of a reactive surface contains information about the reactions that form or modify the surface and, therefore, it should be possible to characterize reactivity using topography parameters such as surface area, roughness, or fractal dimension. As a test of this idea, we consider a two-dimensional (2D) lattice model for crystal dissolution and examine a suite of topography parameters to determine which may be useful for predicting rates and mechanisms of dissolution. The model is based on the assumption that the reactivity of a surface site decreases with the number of nearest neighbors. We show that the steady-state surface topography in our model system is a function of, at most, two variables: the ratio of the rate of loss of sites with two neighbors versus three neighbors (d(2)/d(3)) and the ratio of the rate of loss of sites with one neighbor versus three neighbors (d(1)/d(3)). This means that relative rates can be determined from two parameters characterizing the topography of a surface provided that the two parameters are independent of one another. It also means that absolute rates cannot be determined from measurements of surface topography alone. To identify independent sets of topography parameters, we simulated surfaces from a broad range of d(1)/d(3) and d(2)/d(3) and computed a suite of common topography parameters for each surface. Our results indicate that the fractal dimension D and the average spacing between steps, E[s], can serve to uniquely determine d(1)/d(3) and d(2)/d(3) provided that sufficiently strong correlations exist between the steps. Sufficiently strong correlations exist in our model system when D>1.5 (which corresponds to D>2.5 for real 3D reactive surfaces). When steps are uncorrelated, surface topography becomes independent of step retreat rate and D is equal to 1.5. Under these conditions, measures of surface topography are not independent and any single topography parameter contains all of the available mechanistic

  3. Analysis of reaction cross-section production in neutron induced fission reactions on uranium isotope using computer code COMPLET.

    Science.gov (United States)

    Asres, Yihunie Hibstie; Mathuthu, Manny; Birhane, Marelgn Derso

    2018-04-22

    This study provides current evidence about cross-section production processes in the theoretical and experimental results of neutron induced reaction of uranium isotope on projectile energy range of 1-100 MeV in order to improve the reliability of nuclear stimulation. In such fission reactions of 235 U within nuclear reactors, much amount of energy would be released as a product that able to satisfy the needs of energy to the world wide without polluting processes as compared to other sources. The main objective of this work is to transform a related knowledge in the neutron-induced fission reactions on 235 U through describing, analyzing and interpreting the theoretical results of the cross sections obtained from computer code COMPLET by comparing with the experimental data obtained from EXFOR. The cross section value of 235 U(n,2n) 234 U, 235 U(n,3n) 233 U, 235 U(n,γ) 236 U, 235 U(n,f) are obtained using computer code COMPLET and the corresponding experimental values were browsed by EXFOR, IAEA. The theoretical results are compared with the experimental data taken from EXFOR Data Bank. Computer code COMPLET has been used for the analysis with the same set of input parameters and the graphs were plotted by the help of spreadsheet & Origin-8 software. The quantification of uncertainties stemming from both experimental data and computer code calculation plays a significant role in the final evaluated results. The calculated results for total cross sections were compared with the experimental data taken from EXFOR in the literature, and good agreement was found between the experimental and theoretical data. This comparison of the calculated data was analyzed and interpreted with tabulation and graphical descriptions, and the results were briefly discussed within the text of this research work. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  4. Scientific and Regulatory Considerations in Solid Oral Modified Release Drug Product Development.

    Science.gov (United States)

    Li, Min; Sander, Sanna; Duan, John; Rosencrance, Susan; Miksinski, Sarah Pope; Yu, Lawrence; Seo, Paul; Rege, Bhagwant

    2016-11-01

    This review presents scientific and regulatory considerations for the development of solid oral modified release (MR) drug products. It includes a rationale for patient-focused development based on Quality-by-Design (QbD) principles. Product and process understanding of MR products includes identification and risk-based evaluation of critical material attributes (CMAs), critical process parameters (CPPs), and their impact on critical quality attributes (CQAs) that affect the clinical performance. The use of various biopharmaceutics tools that link the CQAs to a predictable and reproducible clinical performance for patient benefit is emphasized. Product and process understanding lead to a more comprehensive control strategy that can maintain product quality through the shelf life and the lifecycle of the drug product. The overall goal is to develop MR products that consistently meet the clinical objectives while mitigating the risks to patients by reducing the probability and increasing the detectability of CQA failures.

  5. Nanosized aluminum nitride hollow spheres formed through a self-templating solid-gas interface reaction

    International Nuclear Information System (INIS)

    Zheng Jie; Song Xubo; Zhang Yaohua; Li Yan; Li Xingguo; Pu Yikang

    2007-01-01

    Nanosized aluminum nitride hollow spheres were synthesized by simply heating aluminum nanoparticles in ammonia at 1000 deg. C. The as-synthesized sphere shells are polycrystalline with cavity diameters ranging from 15 to 100 nm and shell thickness from 5 to 15 nm. The formation mechanism can be explained by the nanoscale Kirkendall effect, which results from the difference in diffusion rates between aluminum and nitrogen. The Al nanoparticles served as both reactant and templates for the hollow sphere formation. The effects of precursor particle size and temperature were also investigated in terms of product morphology. Room temperature cathode luminescence spectrum of the nanosized hollow spheres showed a broad emission band centered at 415 nm, which is originated from oxygen related luminescence centers. The hollow structure survived a 4-h heat treatment at 1200 deg. C, exhibiting excellent thermal stability. - Graphical abstract: Nanosized aluminum nitride hollow spheres were synthesized by nitridation of aluminum nanoparticles at 1000 deg. C using ammonia

  6. Utilization of Solid Waste as a Substrate for Production of Oil from Oleaginous Microorganisms

    Directory of Open Access Journals (Sweden)

    Fortunate Laker

    2018-01-01

    Full Text Available The overwhelming demand of oil and fats to meet the ever increasing needs for biofuel, cosmetics production, and other industrial purposes has enhanced a number of innovations in this industry. One such innovation is the use of microorganisms as alternative sources of oil and fats. Organic solid waste that is causing a big challenge of disposal worldwide is biodegradable and can be utilized as substrate for alternative oil production. The study evaluated the potential of isolated yeast-like colonies to grow and accumulate oil by using organic solid waste as substrate. Of the 25 yeast-like colonies isolated from the soil samples collected from three different suburbs in Kampala district, Uganda, 20 were screened positive for accumulation of lipid but only 2 were oleaginous. The NHC isolate with the best oil accumulation potential of 48.8% was used in the central composite design (CCD experiments. The CCD experimental results revealed a maximum oil yield of 61.5% from 1.25 g/L cell biomass at 10 g/L of solid waste and temperature of 25°C. The study revealed that organic solid waste could be used as a substrate for microbial oil production.

  7. Utilization of Solid Waste as a Substrate for Production of Oil from Oleaginous Microorganisms.

    Science.gov (United States)

    Laker, Fortunate; Agaba, Arnold; Akatukunda, Andrew; Gazet, Robert; Barasa, Joshua; Nanyonga, Sarah; Wendiro, Deborah; Wacoo, Alex Paul

    2018-01-01

    The overwhelming demand of oil and fats to meet the ever increasing needs for biofuel, cosmetics production, and other industrial purposes has enhanced a number of innovations in this industry. One such innovation is the use of microorganisms as alternative sources of oil and fats. Organic solid waste that is causing a big challenge of disposal worldwide is biodegradable and can be utilized as substrate for alternative oil production. The study evaluated the potential of isolated yeast-like colonies to grow and accumulate oil by using organic solid waste as substrate. Of the 25 yeast-like colonies isolated from the soil samples collected from three different suburbs in Kampala district, Uganda, 20 were screened positive for accumulation of lipid but only 2 were oleaginous. The NHC isolate with the best oil accumulation potential of 48.8% was used in the central composite design (CCD) experiments. The CCD experimental results revealed a maximum oil yield of 61.5% from 1.25 g/L cell biomass at 10 g/L of solid waste and temperature of 25°C. The study revealed that organic solid waste could be used as a substrate for microbial oil production.

  8. Sorghum bagasse as substrate for cellulase production by submerged and solid-state cultures of Trichoderma

    Directory of Open Access Journals (Sweden)

    Teodor Vintilă

    2014-05-01

    Full Text Available Sweet sorghum bagasse was used as cellulosic substrate in submerged and solid-state cultures of Trichoderma for cellulase production. Submerged liquid cultures (SLC were obtained by inoculation of Mandels media containing 1% cellulose with spores suspension of Trichoderma. Solid-state cultures (SSC were carried out in Erlenmayer flasks, where the substrate was distributed 1 cm layers. Comparing the yields of cellulases produced by Trichoderma strains in the systems applied in this study, using as substrate sorghum bagasse, we found the solid-state cultures as the system to produce the highest cellulase yields. The local strain of T. viride CMIT3.5. express high productivity in SSC system in laboratory conditions. The cellulolytic enzymes have maximum activity at 50oC, pH 4,8. The results recommend solid-state cultures of Trichoderma on sorghum bagasse as systems for producing cellulolytic products with higher activity than submerged cultures of Trichoderma on the same substrate.

  9. Investigation of heterogeneous solid acid catalyst performance on low grade feedstocks for biodiesel production: A review

    International Nuclear Information System (INIS)

    Mansir, Nasar; Taufiq-Yap, Yun Hin; Rashid, Umer; Lokman, Ibrahim M.

    2017-01-01

    Highlights: • Solid acid catalysts are proficient to esterifying high free fatty acid feedstocks to biodiesel. • Heterogeneous catalysts have the advantage of easy separation and reusability. • Heterogeneous basic catalysts have limitations due to high FFA of low cost feedstocks. • Solid catalysts having acid and base sites reveal better catalyst for biodiesel production. - Abstract: The conventional fossil fuel reserves are continually declining worldwide and therefore posing greater challenges to the future of the energy sources. Biofuel alternatives were found promising to replace the diminishing fossil fuels. However, conversion of edible vegetable oils to biodiesel using homogeneous acids and base catalysts is now considered as indefensible for the future particularly due to food versus fuel competition and other environmental problems related to catalyst system and feedstock. This review has discussed the progression in research and growth related to heterogeneous catalysts used for biodiesel production for low grade feedstocks. The heterogeneous base catalysts have revealed effective way to produce biodiesel, but it has the limitation of being sensitive to high free fatty acid (FFA) or low grade feedstocks. Alternatively, solid acid catalysts are capable of converting the low grade feedstocks to biodiesel in the presence of active acid sites. The paper presents a comprehensive review towards the investigation of solid acid catalyst performance on low grade feedstock, their category, properties, advantages, limitations and possible remedy to their drawbacks for biodiesel production.

  10. Light-Baryon Production in Binary $pd$ Annihilation Reactions at Rest

    CERN Document Server

    Denisov, O Yu; Balestra, F; Botta, E; Bressani, Tullio; Bussa, M P; Busso, L; Calvo, D; Cerello, P G; Costa, S; D'Isep, D; Fava, L; Feliciello, A; Ferrero, L; Filippi, A; Garfagnini, R; Grasso, A; Iazzi, F; Maggiora, A; Marcello, S; Minetti, B; Mirfakhraee, N; Panzarasa, A; Panzieri, D; Piragino, G; Tosello, F; Zosi, G; Alberico, V; Bertin, A; Bruschi, M; Capponi, M; D'Antone, I; De Castro, S; Ferretti, A; Galli, D; Giacobbe, B; Marconi, U; Piccinini, M; Poli, M; Semprini-Cesari, N; Spighi, R; Vecchi, S; Vagnoni, V M; Vigotti, F; Villa, M; Vitale, A; Zoccoli, A; Bianconi, A; Corradini, M; Lodi-Rizzini, E; Venturelli, L; Zenoni, A; Cicalò, C; Masoni, A; Mauro, S; Puddu, G; Serci, S; Temnikov, P P; Usai, G L; Gortchakov, O E; Prakhov, S N; Rozhdestvensky, A M; Sapozhnikov, M G; Tretyak, V I; Gianotti, P; Guaraldo, C; Lanaro, A; Lucherini, V; Nichitiu, F; Petrascu, C; Ableev, V G; Cavion, C; Gastaldi, Ugo; Lombardi, M; Maron, G; Vannucci, Luigi; Vedovato, G; Bendiscioli, G; Filippini, V; Fontana, A; Montagna, P; Rotondi, A; Salvini, P; Pauli, G; Tessaro, S; Santi, L

    1999-01-01

    We report the study of light baryon production in two-prong annihilation reactions due to antiprotons stopping in gaseous deuterium and detected by the OBELIX spectrometer (LEAR, CERN). A clear signal of the Delta (1232) production in binary reactions was found in both annihilation channels: pd to pi /sup -/ Delta /sup +/( Delta /sup +/ to pi /sup 0/p) and pd to pi /sup 0/ Delta /sup 0/( Delta /sup 0/ to pi /sup -/p). The annihilation probabilities for these reactions turned out to be Y=(1.01+or-0.08)*10/sup -5/ and Y= (1.12+or-0.20)*10/sup -5/, respectively. In addition, the annihilation probability for the prototype Pontecorvo reaction pd to pi /sup -/p was measured with the best world statistics: Y= (1.46+or-0.08)*10/sup -5/. (16 refs).

  11. Reaction Acceleration in Thin Films with Continuous Product Deposition for Organic Synthesis.

    Science.gov (United States)

    Wei, Zhenwei; Wleklinski, Michael; Ferreira, Christina; Cooks, R Graham

    2017-08-01

    Thin film formats are used to study the Claisen-Schmidt base-catalyzed condensation of 6-hydroxy-1-indanone with substituted benzaldehydes and to compare the reaction acceleration relative to the bulk. Relative acceleration factors initially exceeded 10 3 and were on the order of 10 2 at steady state, although the confined volume reaction was not electrostatically driven. Substituent effects were muted compared to those in the corresponding bulk and microdroplet reactions and it is concluded that the rate-limiting step at steady state is reagent transport to the interface. Conditions were found that allowed product deposition from the thin film to occur continuously as the reaction mixture was added and as the solvent evaporated. Yields of 74 % and production rates of 98 mg h -1 were reached in a very simple experimental system that could be multiplexed to greater scales. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Theoretical and experimental study on solid chemical reaction between BaCO3 and TiO2 in microwave field

    International Nuclear Information System (INIS)

    Liu Hanxing; Guo, Liling; Zou Long; Cao Minhe; Zhou Jian; Ouyang Shixi

    2004-01-01

    Solid-state chemical reaction mechanism for the reaction between BaCO 3 and TiO 2 in microwave field was investigated based on X-ray power diffraction (XRD) data and theory of diffusion. The compositions of the resultant after reaction under different conditions were studied by employing XRD. The quantitative analyses based on XRD data showed the reaction in microwave field was quite different from that in the conventional method. A model was proposed to explain the change of the ratio between the reactant BaCO 3 , TiO 2 and the resultant BaTiO 3 for the chemical reaction. The formation kinetic of BaTiO 3 from the BaCO 3 and TiO 2 was calculated by employing this theoretical model. The reaction rate between BaCO 3 and TiO 2 in microwave field was much higher than that in conventional method. The activation energy of the atomic diffusions in this solid chemical reaction is only 58 kJ/mol, which was only about 1/4 of 232 kJ/mol in the conventional value. The result suggests that the microwave field enhance atomic diffusion during the reaction

  13. Bioactive Properties of Maillard Reaction Products Generated From Food Protein-derived Peptides.

    Science.gov (United States)

    Arihara, K; Zhou, L; Ohata, M

    Food protein-derived peptides are promising food ingredients for developing functional foods, since various bioactive peptides are released from food proteins. The Maillard reaction, which plays an important role in most processed foods, generates various chemical components during processing. Although changes of amino acids or proteins and reduced sugars by the Maillard reaction have been studied extensively, such changes of peptides by the Maillard reaction are still not resolved enough. Since food protein-derived peptides are widely utilized in many processed foods, it deserves concern and research on the changes of peptides by the Maillard reaction in foods during processing or storage. This chapter initially overviewed food protein-derived bioactive peptides. Then, Maillard reaction products generated from peptides are discussed. We focused particularly on their bioactivities. © 2017 Elsevier Inc. All rights reserved.

  14. Effects of polyurethane matrices on fungal tannase and gallic acid production under solid state culture

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The influence of the physical structure of polyurethane matrix as a support in a solid state culture in tannase production and gallic acid accumulation by Aspergillus niger Aa-20 was evaluated. Three different polyurethane matrices were used as the support: continuous, semi-discontinuous and discontinuous. The highest tannase production at 2479.59 U/L during the first 12 h of culture was obtained using the discontinuous matrix. The gallic acid was accumulated at 7.64 g/L at the discontinuous matrix. The results show that the discontinuous matrix of polyurethane is better for tannase production and gallic acid accumulation in a solid state culture bioprocess than the continuous and semi-discontinuous matrices.

  15. Solid-state fermentation from dried sweet sorghum stalk for bioethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Almodares, A.; Etemadifar, Z.; Omidi, A. [Univ. of Isfahan, Biology Dept., Univ. of Isfahan, Isfahan (Iran, Islamic Republic of)], e-mail: aalmodares@yahoo.com

    2012-11-01

    Due to depletion of global crude oil, countries are interested to alternate fuel energy resources. Presently bioethanol as a source of energy has been a subject of great interest for the industrialized countries. Therefore, there is need for efficient bioethanol production with low cost raw material and production process. Among energy crops, sweet sorghum is the best candidate for bioethanol production. It has been identified as having higher drought tolerance, lower input cost and higher biomass yield than other energy crops. In addition it has wide adoptability and tolerance to abiotic stresses. Moreover due to the shortage of water in dry and hot countries there is a need to reduce water requirement for bioethanol production and solid state fermentation could be the best process for making bioethanol in these countries. The purpose of this study is to achieve the highest ethanol production with lowest amount of water in solid state fermentation using sweet sorghum stalk. In this study the sweet sorghum particles were used for solid state fermentation. Fermentation medium were: sweet sorghum particles with nutrient media, active yeast powder and different moisture contents. The fermentation medium was incubated for 2-3 days at 30 deg C temperature. The results showed sweet sorghum particles (15% w/w) fermented in medium containing 0.5% yeast inoculums, 73.5% moisture content and 3 days incubation period produced the highest amount of ethanol (13% w/w sorghum)

  16. Formation of doubly and triply bonded unsaturated compounds HCN, HNC, and CH2NH via N + CH4 low-temperature solid state reaction: from molecular clouds to solar system objects

    Science.gov (United States)

    Mencos, Alejandro; Krim, Lahouari

    2018-06-01

    We show in the current study carried out in solid phase at cryogenic temperatures that methane (CH4) ice exposed to nitrogen atoms is a source of two acids HCN, HNC, and their corresponding hydrogenated unsaturated species CH2NH, in addition to CH3, C2H6, CN-, and three nitrogen hydrides NH, NH2, and NH3. The solid state N + CH4 reaction taken in the ground state seems to be strongly temperature dependent. While at temperatures lower than 10 K only CH3, NH, NH2, and NH3 species formation is promoted due to CH bond dissociation and NH bond formation, stable compounds with CN bonds are formed at temperatures ranged between 10 and 40 K. Many of these reaction products, resulting from CH4 + N reaction, have already been observed in N2-rich regions such as the atmospheres of Titan, Kuiper belt objects, and molecular clouds of the interstellar medium. Our results show the power of the solid state N-atom chemistry in the transformation of simple astrochemical relevant species, such as CH4 molecules and N atoms into complex organic molecules which are also potentially prebiotic species.

  17. Optimization of the production of ethyl esters by ultrasound assisted reaction of soybean oil and ethanol

    OpenAIRE

    Rodrigues,S.; Mazzone,L. C. A.; Santos,F. F. P.; Cruz,M. G. A.; Fernandes,F. A. N.

    2009-01-01

    Biodiesel is a renewable liquid fuel that can be produced by a transesterification reaction between a vegetable oil and an alcohol. This paper evaluates and optimizes the production of ethyl esters (biodiesel) from soybean oil and ethanol. The reaction was carried out by applying ultrasound under atmospheric pressure and ambient temperature. Response surface methodology was used to evaluate the influence of alcohol to oil molar ratio and catalyst concentration on the yield of conversion of so...

  18. SCALP: Scintillating ionization chamber for ALPha particle production in neutron induced reactions

    Science.gov (United States)

    Galhaut, B.; Durand, D.; Lecolley, F. R.; Ledoux, X.; Lehaut, G.; Manduci, L.; Mary, P.

    2017-09-01

    The SCALP collaboration has the ambition to build a scintillating ionization chamber in order to study and measure the cross section of the α-particle production in neutron induced reactions. More specifically on 16O and 19F targets. Using the deposited energy (ionization) and the time of flight measurement (scintillation) with a great accuracy, all the nuclear reaction taking part on this project will be identify.

  19. Reactions of the CN Radical with Benzene and Toluene: Product Detection and Low-Temperature Kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Trevitt, Adam J.; Goulay, Fabien; Taatjes, Craig A.; Osborn, David L.; Leone, Stephen R.

    2009-12-23

    Low temperature rate coefficients are measured for the CN + benzene and CN + toluene reactions using the pulsed Laval nozzle expansion technique coupled with laser-induced fluorescence detection. The CN + benzene reaction rate coefficient at 105, 165 and 295 K is found to be relatively constant over this temperature range, 3.9 - 4.9 x 10-10 cm3 molecule-1 s-1. These rapid kinetics, along with the observed negligible temperature dependence, are consistent with a barrierless reaction entrance channel and reaction efficiencies approaching unity. The CN + toluene reaction is measured to have a slower rate coefficient of 1.3 x 10-10 cm3 molecule-1 s-1 at 105 K. At room temperature, non-exponential decay profiles are observed for this reaction that may suggest significant back-dissociation of intermediate complexes. In separate experiments, the products of these reactions are probed at room temperature using synchrotron VUV photoionization mass spectrometry. For CN + benzene, cyanobenzene (C6H5CN) is the only product recorded with no detectable evidence for a C6H5 + HCN product channel. In the case of CN + toluene, cyanotoluene (NCC6H4CH3) constitutes the only detected product. It is not possible to differentiate among the ortho, meta and para isomers of cyanotoluene because of their similar ionization energies and the ~;; 40 meV photon energy resolution of the experiment. There is no significant detection of benzyl radicals (C6H5CH2) that would suggest a H-abstraction or a HCN elimination channel is prominent at these conditions. As both reactions are measured to be rapid at 105 K, appearing to have barrierless entrance channels, it follows that they will proceed efficiently at the temperatures of Saturn?s moon Titan (~;;100 K) and are also likely to proceed at the temperature of interstellar clouds (10-20 K).

  20. Study of reactions for the production of uranium titrafluoride and uranium hexafluoride

    International Nuclear Information System (INIS)

    Guzella, M.F.R.

    1985-01-01

    The main production processes of uranium hexafluoride in pilot plants and industrial facilities are described. The known reactions confirmed in laboratory experiments that lead to Uf 6 or other intermediate fluorides are discussed. For the purpose of determining a thermodinamically feasible reaction involving the sulfur hexafluoride as fluorinating agent, a mock-up facility was designed and constructed as a part of the R and D work planned at the CDTN (Nuclebras Center for Nuclear Technology Development). IN the uranium tatrafluoride synthesis employing U 3 O 8 and SF 6 several experimental parameters are studied. The reaction time, gasflow, temperature and stoechiometic relations among reagents are described in detail. (Author) [pt

  1. Complex nuclear-structure phenomena revealed from the nuclide production in fragmentation reactions

    International Nuclear Information System (INIS)

    Ricciardi, M.V.; Kelic, A.; Napolitani, P.; Schmidt, K.H.; Yordanov, O.; Ignatyuk, A.V.; Rejmund, F.

    2003-12-01

    Complex structural effects in the nuclide production from the projectile fragmentation of 1 A GeV 238 U nuclei in a titanium target are reported. The structure seems to be insensitive to the excitation energy induced in the reaction. This is in contrast to the prominent structural features found in nuclear fission and in transfer reactions, which gradually disappear with increasing excitation energy. Using the statistical model of nuclear reactions, relations to structural effects in nuclear binding and in the nuclear level density are demonstrated. (orig.)

  2. Comprehensive characterisation of products from cobalt catalysed Fischer-Tropsch reaction

    Energy Technology Data Exchange (ETDEWEB)

    Marion, M.C.; Bertoncini, F.; Hugues, F.; Forestiere, A. [IFP, Vernaison (France)

    2006-07-01

    Fischer-Tropsch reaction synthesis has been studied in presence of supported cobalt catalysts. The experimental work has been performed by using a slurry pilot plant. All the gaseous and liquid products, including by-products recovered in the water phase produced, have been analysed in order to determine the whole products distribution and the catalyst selectivity. Apart from paraffin which are the main products obtained via cobalt-catalyzed Fischer-Tropsch synthesis, olefins and oxygenates by-products present also their own distribution. These detailed data are available thanks to new dedicated analytical methods developed in IFP laboratories. (orig.)

  3. Solid-state fermentation: a continuous process for fungal tannase production.

    Science.gov (United States)

    van de Lagemaat, J; Pyle, D L

    2004-09-30

    Truly continuous solid-state fermentations with operating times of 2-3 weeks were conducted in a prototype bioreactor for the production of fungal (Penicillium glabrum) tannase from a tannin-containing model substrate. Substantial quantities of the enzyme were synthesized throughout the operating periods and (imperfect) steady-state conditions seemed to be achieved soon after start-up of the fermentations. This demonstrated for the first time the possibility of conducting solid-state fermentations in the continuous mode and with a constant noninoculated feed. The operating variables and fermentation conditions in the bioreactor were sufficiently well predicted for the basic reinoculation concept to succeed. However, an incomplete understanding of the microbial mechanisms, the experimental system, and their interaction indicated the need for more research in this novel area of solid-state fermentation. Copyright 2004 Wiley Periodicals, Inc.

  4. Accelerated carbonation using municipal solid waste incinerator bottom ash and cold-rolling wastewater: Performance evaluation and reaction kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Chang, E-E [Department of Biochemistry, Taipei Medical University, 250 Wu-Hsing Street, Taipei City, Taiwan 110, Taiwan, ROC (China); Pan, Shu-Yuan [Graduate Institute of Environmental Engineering, National Taiwan University, 71 Chou-Shan Rd., Taipei City, Taiwan 10673, Taiwan, ROC (China); Yang, Liuhanzi [School of Environment, Tsinghua University, Haidin District, Beijing 100084 (China); Chen, Yi-Hung [Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, 1, Sec. 3, Zhongxiao E. Rd., Taipei City, Taiwan 10608, Taiwan, ROC (China); Kim, Hyunook [Department of Energy and Environmental System Engineering, University of Seoul (Korea, Republic of); Chiang, Pen-Chi, E-mail: pcchiang@ntu.edu.tw [Graduate Institute of Environmental Engineering, National Taiwan University, 71 Chou-Shan Rd., Taipei City, Taiwan 10673, Taiwan, ROC (China)

    2015-09-15

    Highlights: • Carbonation was performed using CO{sub 2}, wastewater and bottom ash in a slurry reactor. • A maximum capture capacity of 102 g CO{sub 2} per kg BA was achieved at mild conditions. • A maximum carbonation conversion of MSWI-BA was predicted to be 95% by RSM. • The CO{sub 2} emission from Bali incinerator could be expected to reduce by 6480 ton/y. • The process energy consumption per ton CO{sub 2} captured was estimated to be 180 kW h. - Abstract: Accelerated carbonation of alkaline wastes including municipal solid waste incinerator bottom ash (MSWI-BA) and the cold-rolling wastewater (CRW) was investigated for carbon dioxide (CO{sub 2}) fixation under different operating conditions, i.e., reaction time, CO{sub 2} concentration, liquid-to-solid ratio, particle size, and CO{sub 2} flow rate. The MSWI-BA before and after carbonation process were analyzed by the thermogravimetry and differential scanning calorimetry, X-ray diffraction, and scanning electron microscopy equipped with energy dispersive X-ray spectroscopy. The MSWI-BA exhibits a high carbonation conversion of 90.7%, corresponding to a CO{sub 2} fixation capacity of 102 g per kg of ash. Meanwhile, the carbonation kinetics was evaluated by the shrinking core model. In addition, the effect of different operating parameters on carbonation conversion of MSWI-BA was statistically evaluated by response surface methodology (RSM) using experimental data to predict the maximum carbonation conversion. Furthermore, the amount of CO{sub 2} reduction and energy consumption for operating the proposed process in refuse incinerator were estimated. Capsule abstract: CO{sub 2} fixation process by alkaline wastes including bottom ash and cold-rolling wastewater was developed, which should be a viable method due to high conversion.

  5. Products eco-sustainability analysis using CAD SolidWorks software

    Directory of Open Access Journals (Sweden)

    Popa Luminița I.

    2017-01-01

    Full Text Available This article is focused on the analysis of environmental impact and Eco-sustainability of models designed using CAD SolidWorks software. We have evaluated the material it was made the whole ansamble, in terms of strength, durability and environmental pollution considering the carbon footprint, energy consumption, air acidification and eutrophication. We considered the whole product life-cycle management, from raw material extraction, processing it, piece production, assembly it, and use it until the end of his life, considering the mode of transport and the distance between these stages. The case study presents the virtual model of the product and Sustainability Report.

  6. Toxicological analysis of limonene reaction products using an in vitro exposure system

    Science.gov (United States)

    Anderson, Stacey E.; Khurshid, Shahana S.; Meade, B. Jean; Lukomska, Ewa; Wells, J.R.

    2015-01-01

    Epidemiological investigations suggest a link between exposure to indoor air chemicals and adverse health effects. Consumer products contain reactive chemicals which can form secondary pollutants which may contribute to these effects. The reaction of limonene and ozone is a well characterized example of this type of indoor air chemistry. The studies described here characterize an in vitro model using an epithelial cell line (A549) or differentiated epithelial tissue (MucilAir™). The model is used to investigate adverse effects following exposure to combinations of limonene and ozone. In A549 cells, exposure to both the parent compounds and reaction products resulted in alterations in inflammatory cytokine production. A one hour exposure to limonene + ozone resulted in decreased proliferation when compared to cells exposed to limonene alone. Repeated dose exposures of limonene or limonene + ozone were conducted on MucilAir™ tissue. No change in proliferation was observed but increases in cytokine production were observed for both the parent compounds and reaction products. Factors such as exposure duration, chemical concentration, and sampling time point were identified to influence result outcome. These findings suggest that exposure to reaction products may produce more severe effects compared to the parent compound. PMID:23220291

  7. Optimization and kinetic studies of sea mango (Cerbera odollam) oil for biodiesel production via supercritical reaction

    International Nuclear Information System (INIS)

    Ang, Gaik Tin; Ooi, San Nee; Tan, Kok Tat; Lee, Keat Teong; Mohamed, Abdul Rahman

    2015-01-01

    Highlights: • Sea mango oil as feedstock for biodiesel via non-catalytic supercritical reaction. • Extracted sea mango oil with high FFA could produce high yield of FAME. • Employment of Response Surface Methodology for optimization of FAME. • Kinetic study for reversible transesterification and esterification reactions. - Abstract: Sea mango (Cerbera odollam) oil, which is rich in free fatty acids, was utilized to produce fatty acid methyl esters (FAME) via supercritical transesterification reaction. Sea mango oil was extracted from seeds and was subsequently reacted with methanol in a batch-type supercritical reactor. Response surface methodology (RSM) analysis was used to optimize important parameters, including reaction temperature, reaction time and the molar ratio of methanol to oil. The optimum conditions were found as 380 °C, 40 min and 45:1 mol/mol, respectively, to achieve 78% biodiesel content. The first kinetic modelling of FAME production from sea mango oil incorporating reversible transesterification and reversible esterification was verified simultaneously. The kinetic parameters, including reaction rate constants, k, the pre-exponential constant, A, and the activation energy, Ea, for transesterification and esterification were determined using an ordinary differential equation (ODE45) solver. The highest activation energy of 40 kJ/mol and the lowest reaction rate constant of 2.50 × 10 −5 dm 3 /mol s verified that the first stepwise reaction of TG to produce DG was the rate-limiting step

  8. Hydrogen production characteristics of the organic fraction of municipal solid wastes by anaerobic mixed culture fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Li; Yu, Zhang [Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640 (China)]|[Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Zhenhong, Yuan; Yongming, Sun; Xiaoying, Kong [Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640 (China)

    2009-01-15

    The hydrogen production from the organic fraction of municipal solid waste (OFMSW) by anaerobic mixed culture fermentation was investigated using batch experiments at 37 C. Seven varieties of typical individual components of OFMSW including rice, potato, lettuce, lean meat, oil, fat and banyan leaves were selected to estimate the hydrogen production potential. Experimental results showed that the boiling treated anaerobic sludge was effective mixed inoculum for fermentative hydrogen production from OFMSW. Mechanism of fermentative hydrogen production indicates that, among the OFMSW, carbohydrates is the most optimal substrate for fermentative hydrogen production compared with proteins, lipids and lignocelluloses. This conclusion was also substantiated by experimental results of this study. The hydrogen production potentials of rice, potato and lettuce were 134 mL/g-VS, 106 mL/g-VS, and 50 mL/g-VS respectively. The hydrogen percentages of the total gas produced from rice, potato and lettuce were 57-70%, 41-55% and 37-67%. (author)

  9. Light quality and efficiency of consumer grade solid state lighting products

    DEFF Research Database (Denmark)

    Dam-Hansen, Carsten; Corell, Dennis Dan; Thorseth, Anders

    2013-01-01

    The rapid development in flux and efficiency of Light Emitting Diodes (LED) has resulted in a flooding of the lighting market with Solid State Lighting (SSL) products. Many traditional light sources can advantageously be replaced by SSL products. There are, however, large variations in the quality...... of these products, and some are not better than the ones they are supposed to replace. A lack of quality demands and standards makes it difficult for consumers to get an overview of the SSL products. Here the results of a two year study investigating SSL products on the Danish market are presented. Focus has been...... on SSL products for replacement of incandescent lamps and halogen spotlights. The warm white light and good color rendering properties of these traditional light sources are a must for lighting in Denmark and the Nordic countries. 266 SSL replacement lamps have been tested for efficiency and light...

  10. Evaluation of Productivity of Zymotis Solid-State Bioreactor Based on Total Reactor Volume

    Directory of Open Access Journals (Sweden)

    Oscar F. von Meien

    2002-01-01

    Full Text Available In this work a method of analyzing the performance of solid-state fermentation bioreactors is described. The method is used to investigate the optimal value for the spacing between the cooling plates of the Zymotis bioreactor, using simulated fermentation data supplied by a mathematical model. The Zymotis bioreactor has good potential for those solid-state fermentation processes in which the substrate bed must remain static. The current work addresses two design parameters introduced by the presence of the internal heat transfer plates: the width of the heat transfer plate, which is governed by the amount of heat to be removed and the pressure drop of the cooling water, and the spacing between these heat transfer plates. In order to analyze the performance of the bioreactor a productivity term is introduced that takes into account the volume occupied within the bioreactor by the heat transfer plates. As part of this analysis, it is shown that, for logistic growth kinetics, the time at which the biomass reaches 90 % of its maximum possible value is a good estimate of the optimum harvesting time for maximizing productivity. Application of the productivity analysis to the simulated fermentation results suggests that, with typical fast growing fungi ( = 0.324 h–1, the optimal spacing between heat transfer plates is of the order of 6 cm. The general applicability of this approach to evaluate the productivity of solid-state bioreactors is demonstrated.

  11. Co-digestion of solid waste: Towards a simple model to predict methane production.

    Science.gov (United States)

    Kouas, Mokhles; Torrijos, Michel; Schmitz, Sabine; Sousbie, Philippe; Sayadi, Sami; Harmand, Jérôme

    2018-04-01

    Modeling methane production is a key issue for solid waste co-digestion. Here, the effect of a step-wise increase in the organic loading rate (OLR) on reactor performance was investigated, and four new models were evaluated to predict methane yields using data acquired in batch mode. Four co-digestion experiments of mixtures of 2 solid substrates were conducted in semi-continuous mode. Experimental methane yields were always higher than the BMP values of mixtures calculated from the BMP of each substrate, highlighting the importance of endogenous production (methane produced from auto-degradation of microbial community and generated solids). The experimental methane productions under increasing OLRs corresponded well to the modeled data using the model with constant endogenous production and kinetics identified at 80% from total batch time. This model provides a simple and useful tool for technical design consultancies and plant operators to optimize the co-digestion and the choice of the OLRs. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. Solid-state fermentation of Mortierella isabellina for lipid production from soybean hull.

    Science.gov (United States)

    Zhang, Jianguo; Hu, Bo

    2012-02-01

    Soybean hull, generated from soybean processing, is a lignocellulosic material with limited industrial applications and little market value. This research is exploring a new application of soybean hull to be converted to fungal lipids for biodiesel production through solid-state fermentation. Mortierella isabellina was selected as the oil producer because of its high lipid content at low C/N ratio. Several cultivation factors were investigated, including moisture content, inoculums size, fungal spore age, and nutrient supplements, in an attempt to enhance the lipid production of the solid-state fermentation process. The results showed that lipid production with the increase of the moisture content and the spore age, while decreased as the size of inoculums increased. Nutrients addition (KH₂PO₄ 1.2 mg and MgSO₄ 0.6 mg/g soybean hull) improved the lipid production. The total final lipid reached 47.9 mg lipid from 1 g soybean hull after the conversion, 3.3-fold higher than initial lipid reserve in the soybean hull. The fatty acid profile analysis indicated that fatty acid content consisted of 30.0% of total lipid, and 80.4% of total fatty acid was C16 and C18. Therefore, lipid production from soybean hull is a possible option to enable soybean hull as a new resource for biodiesel production and to enhance the overall oil production from soybeans.

  13. Production of Biodiesel by Esterification of Free Fatty Acid over Solid Catalyst from Biomass Waste

    Science.gov (United States)

    Mukti, N. I. F.; Sutrisno, B.; Hidayat, A.

    2018-05-01

    Recently, low cost feedstocks have been utilized to replace vegetable oils in order to improve the economic feasibility of biodiesel. The esterification of free fatty acid (FFA) on Palm Fatty Acid Distillate (PFAD) with methanol using solid catalyst generated from bagasse fly ash is a promising method to convert FFA into biodiesel. In this research, the esterification of FFA on PFAD using the sulfonated bagasse fly ash catalyst was studied. The performances of the catalysts were evaluated in terms of the reaction temperatures, the molar ratios of methanol to PFAD, and the catalyst loading. The effects of the mass ratio of catalyst to oil (1-10%), the molar ratio of methanol to oil (6:1-12:1), and the reaction temperature (40-60°C) were studied for the conversion of PFAD to optimize the reaction conditions. The results showed that the optimum conditions were methanol to PFAD molar ratio of 12:1, the amount of catalyst of 10%wt. of PFAD, and reaction temperature of 6°C. The reusability of the solid acid carbon catalysts was also studied in this work. The catalytic activity decreased up to 38% after third cycle. The significant decline in catalyst esterification activity was due to acid site leaching. The physico-characteristics and acid site densities were analyzed by Nitrogen gas adsorption, surface functional groups by Fourier transform infrared spectroscopy (FT-IR), elemental analysis using X-ray fluorescent (XRF), and acid-base back titration methods for determination of acid density.

  14. Dietary Maillard reaction products and their fermented products reduce cardiovascular risk in an animal model.

    Science.gov (United States)

    Oh, N S; Park, M R; Lee, K W; Kim, S H; Kim, Y

    2015-08-01

    This study examined the effects of Maillard reaction products (MRP) and MRP fermented by lactic acid bacteria on antioxidants and their enhancement of cardiovascular health in ICR mouse and rat models. In previous in vitro studies, the selected lactic acid bacteria were shown to significantly affect the activity of MRP. The expression of genes (e.g., superoxide dismutase, catalase, and glutathione peroxidase) related to antioxidant activity was upregulated by Maillard-reacted sodium caseinate (cMRP), and cMRP fermented by Lactobacillus fermentum H9 (F-cMRP) synergistically increased the expression of catalase and superoxide dismutase when compared with the high-cholesterol-diet group. Bleeding time, the assay for determination of antithrombotic activity, was significantly prolonged by Maillard-reacted whey protein concentration (wMRP) and wMRP fermented by Lactobacillus gasseri H10 (F-wMRP), similar to the bleeding time of the aspirin group (positive control). In addition, the acute pulmonary thromboembolism-induced mice overcame severe body paralysis or death in both the wMRP and the F-wMRP groups. In the serum-level experiment, cMRP and F-cMRP significantly reduced the serum total and low-density lipoprotein cholesterol levels and triglycerides but had only a slight effect on high-density lipoprotein cholesterol. The levels of aspartate transaminase and alanine transaminase also declined in the cMRP and F-cMRP intake groups compared with the high-cholesterol-diet group. In particular, F-cMRP showed the highest reducing effects on triglycerides, aspartate transaminase, and alanine transaminase. Moreover, the expression of cholesterol-related genes in the F-cMRP group demonstrated greater effects than for the cMRP group in the level of cholesterol 7 α-hydroxylase (CYP7A1), 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR), and low-density lipoprotein receptors compared with the high-cholesterol-diet group. The protective role of cMRP and F-cMRP in the high

  15. Production of krypton isotopes by (p,xn) reactions on bromine

    International Nuclear Information System (INIS)

    Chiengmai, S.N.; Hans, L.; Petter, M.

    1976-06-01

    Radioactive isotopes of the halogens are of great importance when preparing radiopharmaceuticals. 77 Br has mainly been produced by a direct reaction 75 As(α,2n) 77 Br. Recently an indirect way, producing 77 Kr which then decays to 77 Br, has been suggested. Since this provides a convenient method of separation this work develops this idea further making use of high energy protons on bromine Br(p,xn) 77 Kr→ 77 Br. The production cross-section for this reaction has been studied in the proton-energy interval of 20-80 MeV and the optimal production procedures considered. (Auth.)

  16. Production of lactic acid from C6-polyols by alkaline hydrothermal reactions

    International Nuclear Information System (INIS)

    Zhou Huazhen; Jin Fangming; Wu Bing; Cao Jianglin; Duan Xiaokun; Kishita, Atsushi

    2010-01-01

    Production of lactic acid from C6-polyols (Mannitol) under alkaline hydrothermal conditions was investigated. Experiments were performed to examine the difference in the production of lactic acid between C6-polyols and C3-polyols (glycerine), as well as C6-aldoses (glucose). Results showed that the yield of lactic acid from C6-polyols was lower than that from both glycerine and glucose. It indicated that long chain polyols might follow a different reaction pathway from that of glycerine. Further investigation is needed to clarify the reaction mechanism and improve the relatively low lactic acid acid yield from C6-polyols.

  17. Improvements in or relating to process for the production of fuel gas from a carbonaceous solid

    Energy Technology Data Exchange (ETDEWEB)

    1952-12-03

    A process was designed for the generation of fuel gas from a solid carbonaceous fuel containing volatilizable constituents, which comprises admixing the solid carbonaceous fuel in particle form with sufficient water to form a fluid suspension, passing the suspension through a heating zone at an elevated temperature such that substantially all of the water is vaporized, thereby forming a dispersion of coal in steam and causing the dispersion to attain a velocity of at least 60 ft. per second to shatter the particles of coal by collision, passing the resulting dispersion into a fluidized bed of solid carbonaceous material in a methanization zone into contact with carbon monoxide and hydrogen at a temperature within the range of from 900/sup 0/ to 1,800/sup 0/F whereby carbon monoxide and hydrogen are converted to methane and volatilizable constituents of the solid carbonaceous material are distilled therefrom, withdrawing carbonaceous material from the methanization zone and passing it into contact with oxygen and steam in dilute phase in a gasification zone maintained at a temperature within the range of 2,000/sup 0/ to about 3,000/sup 0/F, passing the resulting gases comprising carbon monoxide and hydrogen from the gasification zone into the methanization zone as the source of carbon monoxide and hydrogen, and discharging the gaseous products of the methanization zone as the raw-product fuel gas.

  18. Biodiesel production from esterification of free fatty acid over PA/NaY solid catalyst

    International Nuclear Information System (INIS)

    Liu, Wei; Yin, Ping; Zhang, Jiang; Tang, Qinghua; Qu, Rongjun

    2014-01-01

    Highlights: • Biodiesel production from esterification of oleic acid was catalyzed by PA/NaY. • The influences of the process operating parameters were studied. • RSM was employed to optimize the experimental conditions. • The kinetic equation of the esterification reaction was investigated. - Abstract: Because of the incitements from increasing petroleum prices, diminishing petroleum reserves and the environmental consequences of exhaust gases from petroleum fueled engines, biodiesel has been used as a substitute of the regular diesel in recent years. In this paper, biodiesel production from the esterification of the free fatty oil oleic acid with ethanol catalyzed by PA/NaY (PA = organic phosphonic acid) was investigated, and the effect of reaction conditions such as PA loading, catalyst amount, molar ratio of alcohol to acid, reaction temperature and reaction time on the esterification reaction was examined. The process optimization using response surface methodology (RSM) was performed and the interactions between the operational variables were elucidated. The optimum values for maximum conversion ratio of oleic acid could be obtained by using a Box–Behnken center-united design with a minimum of experimental work. The oleic acid conversion reached 79.51 ± 0.68% with the molar ratio of alcohol to oleic acid being 7:1 and 1.7 g PA/NaY catalyst (20 ml of PA loading) at 105 °C for 7 h. Moreover, a kinetic model for the esterification catalyzed by PA/NaY catalyst was established. By fitting the kinetic model with the experimental results, the reaction order n = 2, activation energy of the positive reaction Ea + = 43.41 kJ/mol and that of the reverse reaction Ea − = 59.74 kJ/mol were obtained

  19. Mathematical model to analyze the dissolution behavior of metastable crystals or amorphous drug accompanied with a solid-liquid interface reaction.

    Science.gov (United States)

    Hirai, Daiki; Iwao, Yasunori; Kimura, Shin-Ichiro; Noguchi, Shuji; Itai, Shigeru

    2017-04-30

    Metastable crystals and the amorphous state of poorly water-soluble drugs in solid dispersions (SDs), are subject to a solid-liquid interface reaction upon exposure to a solvent. The dissolution behavior during the solid-liquid interface reaction often shows that the concentration of drugs is supersaturated, with a high initial drug concentration compared with the solubility of stable crystals but finally approaching the latter solubility with time. However, a method for measuring the precipitation rate of stable crystals and/or the potential solubility of metastable crystals or amorphous drugs has not been established. In this study, a novel mathematical model that can represent the dissolution behavior of the solid-liquid interface reaction for metastable crystals or amorphous drug was developed and its validity was evaluated. The theory for this model was based on the Noyes-Whitney equation and assumes that the precipitation of stable crystals at the solid-liquid interface occurs through a first-order reaction. Moreover, two models were developed, one assuming that the surface area of the drug remains constant because of the presence of excess drug in the bulk and the other that the surface area changes in time-dependency because of agglomeration of the drug. SDs of Ibuprofen (IB)/polyvinylpyrrolidone (PVP) were prepared and their dissolution behaviors under non-sink conditions were fitted by the models to evaluate improvements in solubility. The model assuming time-dependent surface area showed good agreement with experimental values. Furthermore, by applying the model to the dissolution profile, parameters such as the precipitation rate and the potential solubility of the amorphous drug were successfully calculated. In addition, it was shown that the improvement in solubility with supersaturation was able to be evaluated quantitatively using this model. Therefore, this mathematical model would be a useful tool to quantitatively determine the supersaturation

  20. Modern microbial solid state fermentation technology for future biorefineries for the production of added-value products

    Directory of Open Access Journals (Sweden)

    Musaalbakri Abdul Manan

    2017-12-01

    Full Text Available The promise of industrial biotechnology has been around since Chaim Weizmann developed acetone–butanol–ethanol fermentation at the University of Manchester in 1917 and the prospects nowadays look brighter than ever. Today’s biorefinery technologies would be almost unthinkable without biotechnology. This is a growing trend and biorefineries have also increased in importance in agriculture and the food industry. Novel biorefinery processes using solid state fermentation (SSF technology have been developed as alternative to conventional processing routes, leading to the production of added-value products from agriculture and food industry raw materials. SSF involves the growth of microorganisms on moist solid substrate in the absence of free-flowing water. Future biorefineries based on SSF aim to exploit the vast complexity of the technology to modify biomass produced by agriculture and the food industry for valuable by-products through microbial bioconversion. In this review, a summary has been made of the attempts at using modern microbial SSF technology for future biorefineries for the production of many added-value products ranging from feedstock for the fermentation process and biodegradable plastics to fuels and chemicals.