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Sample records for reduction process reduccion

  1. Resist process optimization for further defect reduction

    NASA Astrophysics Data System (ADS)

    Tanaka, Keiichi; Iseki, Tomohiro; Marumoto, Hiroshi; Takayanagi, Koji; Yoshida, Yuichi; Uemura, Ryouichi; Yoshihara, Kosuke

    2012-03-01

    Defect reduction has become one of the most important technical challenges in device mass-production. Knowing that resist processing on a clean track strongly impacts defect formation in many cases, we have been trying to improve the track process to enhance customer yield. For example, residual type defect and pattern collapse are strongly related to process parameters in developer, and we have reported new develop and rinse methods in the previous papers. Also, we have reported the optimization method of filtration condition to reduce bridge type defects, which are mainly caused by foreign substances such as gels in resist. Even though we have contributed resist caused defect reduction in past studies, defect reduction requirements continue to be very important. In this paper, we will introduce further process improvements in terms of resist defect reduction, including the latest experimental data.

  2. Reduction of metal oxides through mechanochemical processing

    DOEpatents

    Froes, Francis H.; Eranezhuth, Baburaj G.; Senkov, Oleg N.

    2000-01-01

    The low temperature reduction of a metal oxide using mechanochemical processing techniques. The reduction reactions are induced mechanically by milling the reactants. In one embodiment of the invention, titanium oxide TiO.sub.2 is milled with CaH.sub.2 to produce TiH.sub.2. Low temperature heat treating, in the range of 400.degree. C. to 700.degree. C., can be used to remove the hydrogen in the titanium hydride.

  3. Carbon dioxide reduction by the Bosch process

    NASA Technical Reports Server (NTRS)

    Manning, M. P.; Reid, R. C.

    1975-01-01

    Prototype units for carrying out the reduction of carbon dioxide to elementary carbon have been built and operated successfully. In some cases, however, startup difficulties have been reported. Moreover, the recycle reactor product has been reported to contain only small amounts of water and undesirably high yields of methane. This paper presents the results of the first phase of an experimental study that was carried out to define the mechanisms occurring in the reduction process. Conclusions are drawn and possible modifications to the present recycle process are suggested.

  4. Toxicity reduction of photo processing wastewaters

    USGS Publications Warehouse

    Wang, W.

    1992-01-01

    The photo processing industry can be characterized by treatment processes and subsequent silver recovery. The effluents generated all contain various amounts of silver. The objectives of this study were to determine toxicity of photo processing effluents and to explore their toxicity mitigation. Six samples, from small shops to a major photo processing center, were studied. Two samples (I and VI) were found to be extremely toxic, causing 100 and 99% inhibition of duckweed frond reproduction, respectively, and were used for subsequent toxicity reduction experiments. Lime and sodium sulfide were effective for the toxicity reduction of Sample VI; both reduced its toxicity to negligible. Sample I was far more toxic and was first diluted to 2.2% and then treated with 0.5 g lime/100 mL, reducing toxicity from 100% to 12% inhibition.

  5. Process simulation of aluminum reduction cells

    SciTech Connect

    Tabsh, I.; Dupuis, M.; Gomes, A.

    1996-10-01

    A program was developed to model the dynamic behavior of an aluminum reduction cell. The program simulates the physical process by solving the heat and mass balance equations that characterize the behavior of eleven chemical species in the system. It also models operational events (such as metal tapping, anode change, etc.) and the process control logic including various alumina feeding policies and anode effect quenching. The program is a PC based Windows{reg_sign} application that takes full advantage of the Windows user interface. This paper describes the implementation of the process model and the control logic. Various results using the simulation are compared to measured data.

  6. Cataclasis and processes of particle size reduction

    NASA Astrophysics Data System (ADS)

    Blenkinsop, Tom G.

    1991-05-01

    The particle size distribution (P.S.D.) of fragmented geological materials is affected by the fragmentation process, initial size distribution, number of fracturing events, energy input, strain, and confining pressure. A summary of literature shows that the fractal dimension ( D) of the P.S.D. is increased by the number of fracturing events, energy input, strain, and confining pressure. Cenozoic cataclasis of granite, granodiorites, gneisses and arkose seen in cores from the Cajon Pass drillhole, southern California, produced P.S.D.s with values of D that varied from 1.88 to 3.08. Each rock type has a characteristic and more limited range of D. Areas of dilatant texture and mode I fracture-fillings have low average values (2.32 and 2.37) compared to an average value of 2.67 in shear fracture-fillings D has a good inverse correlation with average particle size. Data from fault rocks in the San Gabriel fault zone, southern California ( Anderson et al., 1983) have been reanalyzed to show that values of D are higher (2.10 5.52) and average particle size is lower than the Cajon Pass samples, but the ranges of values overlap, and the inverse correlation between D and average particle size is extended. Microstructural observations combined with these results suggest that three processes contributed to particle size reduction during cataclasis. The first process of feldspar alteration, which leads to low values of D, has not been previously recognized. The second process is probably constrained comminution ( Sammis et al., 1987), since the average D in shear fracture-fillings is close to the value of 2.58 predicted by this theory. A further stage of particle size reduction is demonstrated by an increase of D with cataclasis. This third process is selective fracture of larger particles, which may also operate during localization and the cataclastic flow-to-faulting transition as observed in experiments. A transition from constrained comminution to selective fracture of

  7. Process for energy reduction with flash fusing

    SciTech Connect

    Berkes, J.S.

    1987-10-06

    This patent describes a process for affecting a reduction in the energy needed for accomplishing the flash fusing of a developed image which comprises (1) providing a toner composition with resin particles, pigment articles, and wax. The wax possesses a lower melting temperature than the resin particles and is selected from the group consisting of polyethylene and polypropylene with a molecular weight of less than about 6,000; (2) introducing the aforementioned toner composition into a xerographic imaging apparatus having incorporated therein a flash fusing device; (3) generating an electrostatic latent image in the imaging apparatus, and subsequently developing this image with the toner composition; (4) transferring the image to a supporting substrate; and (5) permanently attaching the image to the substrate with energy emitted from a flash fusing device, and wherein there is formed between the supporting substrate and the toner composition during fusing a wax layer.

  8. Advanced Reduction Processes: A New Class of Treatment Processes

    PubMed Central

    Vellanki, Bhanu Prakash; Batchelor, Bill; Abdel-Wahab, Ahmed

    2013-01-01

    Abstract A new class of treatment processes called advanced reduction processes (ARPs) is proposed. ARPs combine activation methods and reducing agents to form highly reactive reducing radicals that degrade oxidized contaminants. Batch screening experiments were conducted to identify effective ARPs by applying several combinations of activation methods (ultraviolet light, ultrasound, electron beam, and microwaves) and reducing agents (dithionite, sulfite, ferrous iron, and sulfide) to degradation of four target contaminants (perchlorate, nitrate, perfluorooctanoic acid, and 2,4 dichlorophenol) at three pH-levels (2.4, 7.0, and 11.2). These experiments identified the combination of sulfite activated by ultraviolet light produced by a low-pressure mercury vapor lamp (UV-L) as an effective ARP. More detailed kinetic experiments were conducted with nitrate and perchlorate as target compounds, and nitrate was found to degrade more rapidly than perchlorate. Effectiveness of the UV-L/sulfite treatment process improved with increasing pH for both perchlorate and nitrate. We present the theory behind ARPs, identify potential ARPs, demonstrate their effectiveness against a wide range of contaminants, and provide basic experimental evidence in support of the fundamental hypothesis for ARP, namely, that activation methods can be applied to reductants to form reducing radicals that degrade oxidized contaminants. This article provides an introduction to ARPs along with sufficient data to identify potentially effective ARPs and the target compounds these ARPs will be most effective in destroying. Further research will provide a detailed analysis of degradation kinetics and the mechanisms of contaminant destruction in an ARP. PMID:23840160

  9. Application of lithium in molten-salt reduction processes.

    SciTech Connect

    Gourishankar, K. V.

    1998-11-11

    Metallothermic reductions have been extensively studied in the field of extractive metallurgy. At Argonne National Laboratory (ANL), we have developed a molten-salt based reduction process using lithium. This process was originally developed to reduce actinide oxides present in spent nuclear fuel. Preliminary thermodynamic considerations indicate that this process has the potential to be adapted for the extraction of other metals. The reduction is carried out at 650 C in a molten-salt (LiCl) medium. Lithium oxide (Li{sub 2}O), produced during the reduction of the actinide oxides, dissolves in the molten salt. At the end of the reduction step, the lithium is regenerated from the salt by an electrowinning process. The lithium and the salt from the electrowinning are then reused for reduction of the next batch of oxide fuel. The process cycle has been successfully demonstrated on an engineering scale in a specially designed pyroprocessing facility. This paper discusses the applicability of lithium in molten-salt reduction processes with specific reference to our process. Results are presented from our work on actinide oxides to highlight the role of lithium and its effect on process variables in these molten-salt based reduction processes.

  10. Coal fueled ported kiln direct reduction process in Norway

    SciTech Connect

    Rierson, D.W.

    1994-12-31

    Allis Mineral Systems (AMS), formerly the minerals processing group at Allis-Chalmers Corporation, developed a ported kiln process in the 1960`s specifically for the direct reduction of iron ore. The process is called ACCAR. This ported kiln technology has more recently been coupled with AMS` GRATE-KILN System for iron oxide pelletizing into the GRATE-CAR Process, for minerals reduction. The GRATE-CAR Process can handle a fine grained ore concentrate through the steps of agglomeration, induration and reduction in a single production line.

  11. Defective Reduction in Automotive Headlining Manufacturing Process

    NASA Astrophysics Data System (ADS)

    Rittichai, Saranya; Chutima, Parames

    2016-05-01

    In an automobile parts manufacturing company, currently the headlining process has a lot of wastes resulting in a high cost of quality per year. In this paper, the Six Sigma method is used to reduce the defects in the headlining process. Cause-and-effect matrix and failure mode and effect analysis (FMEA) were adopted to screen the factors that affect the quality of headlining. The 2k-1 fractional factorials design was also use to determine the potential preliminary root causes. The full factorial experiments was conducted to identify appropriate settings of the significant factors. The result showed that the process can reduce the defects of headlining from 12.21% to 6.95%

  12. Wet trimming process for critical dimension reduction

    NASA Astrophysics Data System (ADS)

    Sun, Sam X.; Smith, Brian A.; Qin, Anwei

    2008-03-01

    Plasma trimming is a method widely used to achieve small feature sizes beyond the capability of photolithography. Plasma processes reduce the dimensions of photoresist, anti-reflective coating, hardmask, or device substrate patterns with varying degrees of anisotropy. The vertical trim rate is higher than or equal to the lateral trim rate. As a result, much of the line-edge roughness from the resist pattern remains. High aspect-ratio resist patterns are subject to necking and collapse during this process. However, by using a developer-soluble hardmask in place of traditional anti-reflective layers, it is possible to achieve controllable, anisotropic trim rates, as well as reduced roughness. Moreover, the process benefits from a very thin resist, or imaging layer, instead of relying on a thicker mask with a high aspect-ratio. The hardmask is patterned during a standard resist develop step, and the resist may be stripped prior to substrate etching due to the high etch resistance of the hardmask. Many other advantages have been discovered from this wet trimming process, including high resolution, extended depth of focus, controllable trim rate, and lower cost than traditional methods.

  13. AMPERE Science Data Reduction and Processing

    NASA Astrophysics Data System (ADS)

    Korth, H.; Dyrud, L.; Anderson, B.; Waters, C. L.; Barnes, R. J.

    2010-12-01

    The Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) uses the constellation of Iridium Communications satellites in 780-km-altitude, circular, near-polar orbits to monitor the electro-dynamic coupling of the ionosphere to the surrounding space environment in real time. The constellation consists of 66 satellites plus on-orbit spares, and each satellite carries a magnetometer for attitude determination. The magnetometer data are continuously sent from Iridium Satellite Network Operations Center to the AMPERE Science Data Center, where they are processed to extract the magnetic perturbation signatures associated with the Birkeland currents. This is accomplished by first merging real-time telemetry packets from each satellite into time-ordered sets of records, formatting and compiling a database. Subsequent processing automatically evaluates baselines, inter-calibrates magnetic field data between satellites, and quantifies the magnetic field residuals with the goal to reduce errors to the 30-nT digitization resolution of the magnetometers. The magnetic field residuals are then used to rank the quality of the data from the individual satellites and weight the data in subsequent science processing. Because magnetic fields generated by the Birkeland currents represent typically less than one percent of the total magnetic field, numerous challenges must be overcome to derive reliable magnetic perturbation signals. For example, corrections to the IGRF magnetic field model must be applied and adverse effects due to missing data must be mitigated. In the final processing step the Birkeland currents are derived by applying Ampere's law to the spherical harmonic fit of the perturbation data. We present the processing methodology, discuss the sensitivity of the Birkeland currents on the accuracy of the derived magnetic perturbations, and show a preliminary analysis of the 3-5 August 2010 geomagnetic storm.

  14. Hybrid process for nitrogen oxides reduction

    SciTech Connect

    Epperly, W.R.; Sprague, B.N.

    1991-09-10

    This patent describes a process for reducing the nitrogen oxide concentration in the effluent from the combustion of a carbonaceous fuel. It comprises introducing into the effluent a first treatment agent comprising a nitrogenous composition selected from the group consisting of urea, ammonia, hexamethylenetetramine, ammonium salts of organic acids, 5- or 6-membered heterocyclic hydrocarbons having at least one cyclic nitrogen, hydroxy amino hydrocarbons, NH{sub 4}-lignosulfonate, fur-furylamine, tetrahydrofurylamine, hexamethylenediamine, barbituric acid, guanidine, guanidine carbonate, biguanidine, guanylurea sulfate, melamine, dicyandiamide, biuret, 1.1{prime}-azobisformamide, methylol urea, methylol urea-urea condensation product, dimethylol urea, methyl urea, dimethyl urea, calcium cyanamide, and mixtures thereof under conditions effective to reduce the nitrogen oxides concentration and ensure the presence of ammonia in the effluent; introducing into the effluent a second treatment agent comprising an oxygenated hydrocarbon at an effluent temperature of about 500{degrees} F. to about 1600{degrees} F. under conditions effective to oxidize nitric oxide in the effluent to nitrogen dioxide and ensure the presence of ammonia at a weight ratio of ammonia to nitrogen dioxide of about 1:5 to about 5:1; and contacting the effluent with an aqueous scrubbing solution having a pH of 12 or lower under conditions effective to cause nitrogen dioxide to be absorbed therein.

  15. Molecular Modeling of Environmentally Important Processes: Reduction Potentials

    ERIC Educational Resources Information Center

    Lewis, Anne; Bumpus, John A.; Truhlar, Donald G.; Cramer, Christopher J.

    2004-01-01

    The increasing use of computational quantum chemistry in the modeling of environmentally important processes is described. The employment of computational quantum mechanics for the prediction of oxidation-reduction potential for solutes in an aqueous medium is discussed.

  16. Evaluation of process for sludge particle size reduction

    SciTech Connect

    Precechtel, D.R.; Packer, M.J., Fluor Daniel Hanford

    1997-03-18

    This document evaluates the available technology for K Basin sludge particle size. The results can be used to demonstrate the sensitivity or lack thereof, of K Basin sludge to available reduction processes and TWRS proposed particle acceptance criteria.

  17. Reductive stripping process for uranium recovery from organic extracts

    DOEpatents

    Hurst, Jr., Fred J.

    1985-01-01

    In the reductive stripping of uranium from an organic extractant in a uranium recovery process, the use of phosphoric acid having a molarity in the range of 8 to 10 increases the efficiency of the reductive stripping and allows the strip step to operate with lower aqueous to organic recycle ratios and shorter retention time in the mixer stages. Under these operating conditions, less solvent is required in the process, and smaller, less expensive process equipment can be utilized. The high strength H.sub.3 PO.sub.4 is available from the evaporator stage of the process.

  18. Reductive stripping process for uranium recovery from organic extracts

    DOEpatents

    Hurst, F.J. Jr.

    1983-06-16

    In the reductive stripping of uranium from an organic extractant in a uranium recovery process, the use of phosphoric acid having a molarity in the range of 8 to 10 increases the efficiency of the reductive stripping and allows the strip step to operate with lower aqueous to organic recycle ratios and shorter retention time in the mixer stages. Under these operating conditions, less solvent is required in the process, and smaller, less expensive process equipment can be utilized. The high strength H/sub 3/PO/sub 4/ is available from the evaporator stage of the process.

  19. Computer program developed for flowsheet calculations and process data reduction

    NASA Technical Reports Server (NTRS)

    Alfredson, P. G.; Anastasia, L. J.; Knudsen, I. E.; Koppel, L. B.; Vogel, G. J.

    1969-01-01

    Computer program PACER-65, is used for flowsheet calculations and easily adapted to process data reduction. Each unit, vessel, meter, and processing operation in the overall flowsheet is represented by a separate subroutine, which the program calls in the order required to complete an overall flowsheet calculation.

  20. SELECTION AND PRELIMINARY EVALUATION OF ALTERNATIVE REDUCTANTS FOR SRAT PROCESSING

    SciTech Connect

    Stone, M.; Pickenheim, B.; Peeler, D.

    2009-06-30

    Defense Waste Processing Facility - Engineering (DWPF-E) has requested the Savannah River National Laboratory (SRNL) to perform scoping evaluations of alternative flowsheets with the primary focus on alternatives to formic acid during Chemical Process Cell (CPC) processing. The reductants shown below were selected for testing during the evaluation of alternative reductants for Sludge Receipt and Adjustment Tank (SRAT) processing. The reductants fall into two general categories: reducing acids and non-acidic reducing agents. Reducing acids were selected as direct replacements for formic acid to reduce mercury in the SRAT, to acidify the sludge, and to balance the melter REDuction/OXidation potential (REDOX). Non-acidic reductants were selected as melter reductants and would not be able to reduce mercury in the SRAT. Sugar was not tested during this scoping evaluation as previous work has already been conducted on the use of sugar with DWPF feeds. Based on the testing performed, the only viable short-term path to mitigating hydrogen generation in the CPC is replacement of formic acid with a mixture of glycolic and formic acids. An experiment using glycolic acid blended with formic on an 80:20 molar basis was able to reduce mercury, while also targeting a predicted REDuction/OXidation (REDOX) of 0.2 expressed as Fe{sup 2+}/{Sigma}Fe. Based on this result, SRNL recommends performing a complete CPC demonstration of the glycolic/formic acid flowsheet followed by a design basis development and documentation. Of the options tested recently and in the past, nitric/glycolic/formic blended acids has the potential for near term implementation in the existing CPC equipment providing rapid throughput improvement. Use of a non-acidic reductant is recommended only if the processing constraints to remove mercury and acidify the sludge acidification are eliminated. The non-acidic reductants (e.g. sugar) will not reduce mercury during CPC processing and sludge acidification would

  1. Sludge reduction and performance analysis of a modified sludge reduction process.

    PubMed

    Zhou, Zhen; Qiao, Weimin; Xing, Can; Wang, Yingjun; Wang, Chunying; Wang, Yifang; Wang, Yiru; Wang, Luochun

    2014-01-01

    A modified sludge process reduction activated sludge (SPRAS) technology was developed by inserting a sludge process reduction (SPR) module, composed of an aeration tank and a settler, before the activated sludge system was proposed in this study. Compared with the anaerobic/anoxic/aerobic (AAO) process, the SPRAS resulted in a remarkable decrease in sludge production by 76.6%; sludge decay owing to lengthy solids retention time (about 121.5 d) could be the major cause. During the 217-day operation, the oxidation-reduction potential (ORP) (from 54 to -198 mV) and pH (from 7.8 to 5.0) at the bottom of the SPR settler gradually decreased, and low ORP and pH were in favor of sludge reduction in the SPRAS system. The insertion of the SPR module improved the removal efficiencies of suspended solids, chemical oxygen demand and ammonium nitrogen, and total nitrogen concentration in the effluent was reduced from 23.89 ± 4.82 to 14.16 ± 3.98 mg/L by 50% influent bypassing the SPR module. These results indicated that the SPRAS process could produce much less excess sludge and guarantee better effluent quality than the AAO process.

  2. sIPV process development for costs reduction.

    PubMed

    Thomassen, Yvonne E; Bakker, Wilfried A M

    2015-08-20

    Polio is expected to be eradicated within only a few years from now. Upon polio eradication, the use of oral polio vaccines, which can cause circulating and virulent vaccine derived polio viruses, will be stopped. From this moment onwards, inactivated polio vaccines (IPV) will be used for worldwide vaccination against polio. An increased demand for IPV is thus anticipated. As a result, process development studies regarding the IPV production process, developed in the 1960s, have intensified. Studies on yield optimization aiming at costs reduction as well as the use of alternative polio viruses, which are more biosafe for manufacturing, are actual. Here our strategy to setup a new IPV production process using attenuated Sabin polio virus strains is presented. Moreover, aspects on reduction of the costs of goods and the impact of process optimization on sIPV costs are reviewed.

  3. Quantitative prediction of reduction in large pipe setting round process

    NASA Astrophysics Data System (ADS)

    Zhao, Jun; Zhan, Peipei; Ma, Rui; Zhai, Ruixue

    2013-07-01

    The control manner during the process to ensure the quality of pipe products mainly relies on the operator's experience, so it is very necessary to study the setting round process and obtain its spring-back law. The setting round process is shaping an oval section pipe into circular section, so it is difficult to provide a quantificational analysis for its spring-back process because of the curvature inequality of pipe section neutral layer. However, the spring-back law of the circle-oval process can be easily predicted. The experimental method is firstly used to establish the equivalent effect between the setting round process and the circle-oval process. The setting round process can be converted into the circle-oval process. There are two difficulties in the theoretical analysis for the circle-oval process: elastic-plastic bending problem of curved beam; statically indeterminate problem. A quantitative analytic method for the circle-oval process is presented on the basis of combination of the spring-back law of plane curved beam with the element dividing idea in finite element method. The ovality after unloading versus the relative reduction is plotted with analytical and experimental results respectively, which shows a fair agreement. Finally, the method of quantitative prediction of reduction for large pipe setting round is given based on the equivalent effect and the analytical results. Five pipes, which are needed to be set round, are used to carry out experiment so as to verify this method. The results of verification experiment indicates that, in the experimental range, the residual ovality are all under 0.35% after the once only setting round with the theoretical prediction reductions. It is much less than the 1% requirement of pipe standard. Applying the established theoretical analysis is able to correct the pipe ovality with sufficient accuracy, which provides theoretical direction to plant use.

  4. Pilot scale treatment of chromite ore processing residue using sodium sulfide in single reduction and coupled reduction/stabilization processes.

    PubMed

    Velasco, Antonio; Ramírez, Martha; Hernández, Sergio; Schmidt, Winfried; Revah, Sergio

    2012-03-15

    Single Cr(VI) reduction and coupled reduction/stabilization (R/S) processes were evaluated at pilot scale to determine their effectiveness to treat chromite ore processing residue (COPR). Sodium sulfide was used as the reducing agent and cement, gypsum and lime were tested as the stabilizing agents. The pilot experiments were performed in a helical ribbon blender mixer with batches of 250 kg of COPR and mixing time up to 30 min. Na2S/Cr(VI) mass ratios of 4.6, 5.7 and 6.8 were evaluated in the single reduction process to treat COPR with Cr(VI) concentration of ≈4.2 g/kg. The R/S process was tested with a Na2S/Cr(VI) mass ratio of 5.7 and including stabilizing agents not exceeding 5% (w/w(COPR)), to treat COPR with a Cr(VI) content of ≈5.1g/kg. The single reduction process with a ratio of 6.8, reached Cr(VI) reduction efficiencies up to 97.6% in the first days, however these values decreased to around 93% after 380 days of storage. At this point the total Cr level was around 12.5 mg/L. Cr(VI) removal efficiencies exceeding 96.5% were reached and maintained during 380 days when the coupled R/S process was evaluated. Total Cr levels lower than 5 mg/l were attained at the initials days in all R/S batch tested, however after 380 days, concentrations below the regulatory limit were only found with gypsum (2%) as single agent and with a blend of cement (4%) and lime (1%). These results indicated that the coupled R/S process is an excellent alternative to stabilize COPR.

  5. Investigation of reduction process and related impurities in ezetimibe.

    PubMed

    Zhang, Dengfeng; Su, Jiangtao

    2015-03-25

    During the synthesis of ezetimibe bulk drug, research for the impurities which especially come from the last two steps of synthetic route is of great significance for the quality by design (QbD) concept. The design spaces of last two steps of reduction reaction were established. The critical parameters were discussed under the QbD concept, which have noticeable impact on the impurity profile such as the new process related impurities mentioned in this paper. Three novel reduction process related impurities were prepared by designed synthetic route and co-injected with ezetimibe sample for identification. These novel process related impurities were also detected in different laboratory batches of ezetimibe bulk drug and characterized using MS, (1)H, (13)C, 2D NMR and IR techniques. The synthesis, isolation, identification, structural elucidation and formation of impurities were also discussed in detail.

  6. Reduction of nitrobenzene by the catalyzed Fe/Cu process.

    PubMed

    Xu, Wenying; Li, Ping; Fan, Jinhong

    2008-01-01

    The polarization behavior of the couple Fe/Cu in 100 mg/L nitrobenzene aqueous solution was studied using Evans coupling diagrams. The results indicated that the iron corrosion was limited by both anodic and cathodic half-cell reactions under the neutral conditions, and cathodically controlled under the alkaline conditions. Batch experiments were performed to study the effect of solution pH, reaction duration, concentration, type of electrolyte, and dissolved oxygen (DO) on the reduction of nitrobenzene by the catalyzed Fe/Cu process. This process proved effective in the pH range of 3 to 11. The conversion efficiency of nitrobenzene at pH around 10.1 was almost the same as that under highly acid conditions (pH around 3). The degradation of nitrobenzene fell into two phases: adsorption and surface reduction, and the influence of adsorption and mass transfer became more extensive with solution concentration. The reduction rate decreased in the presence of DO in the solution, indicating that a need for aeration was eliminated in the catalyzed Fe/Cu process. Accordingly, spending on energy consumption would be reduced. Economic analysis indicated that merely 0.05 kg was required for the treatment of a ton of nitrobenzene-containing water with pH from 3 to 11. The catalyzed Fe/Cu process is cost-effective and of practical value.

  7. Process for the reduction of nitrogen oxides in an effluent

    SciTech Connect

    Epperly, W.R.; Sullivan, J.C.; Sprague, B.N.

    1989-07-04

    This patent describes a process for the reduction of the concentration of nitrogen oxides in the effluent from the combustion of a carbonaceous fuel. The process comprises introducing a treatment agent which comprises a composition selected from the group consisting of NH/sub 4/-lignosulfonate, calcium lignosulfonate, 2-furoic acid, 1,3 dioxolane, tetrahydrofuran, furfurylamine, furfurylalcohol, gluconic acid, citric acid, n-butyl acetate, 1,3 butylene glycol, methylal, tetrahydrofuryl alcohol, furan, fish oil, coumalic acid, furfuryl acetate, tetrahydrofuran 2,3,4,5-tetracarboxylic acid, tetrahydrofurylamine, furylacrylic acid, tetrahydropyran, 2,5-furandimethanol, mannitol, hexamethylenediamine, barbituric acid, acetic anhydride, oxalic acid, mucic acid and d-galactose.

  8. Gene regulation and noise reduction by coupling of stochastic processes

    PubMed Central

    Hornos, José Eduardo M.; Reinitz, John

    2015-01-01

    Here we characterize the low noise regime of a stochastic model for a negative self-regulating binary gene. The model has two stochastic variables, the protein number and the state of the gene. Each state of the gene behaves as a protein source governed by a Poisson process. The coupling between the the two gene states depends on protein number. This fact has a very important implication: there exist protein production regimes characterized by sub-Poissonian noise because of negative covariance between the two stochastic variables of the model. Hence the protein numbers obey a probability distribution that has a peak that is sharper than those of the two coupled Poisson processes that are combined to produce it. Biochemically, the noise reduction in protein number occurs when the switching of genetic state is more rapid than protein synthesis or degradation. We consider the chemical reaction rates necessary for Poisson and sub-Poisson processes in prokaryotes and eucaryotes. Our results suggest that the coupling of multiple stochastic processes in a negative covariance regime might be a widespread mechanism for noise reduction. PMID:25768447

  9. Gene regulation and noise reduction by coupling of stochastic processes

    NASA Astrophysics Data System (ADS)

    Ramos, Alexandre F.; Hornos, José Eduardo M.; Reinitz, John

    2015-02-01

    Here we characterize the low-noise regime of a stochastic model for a negative self-regulating binary gene. The model has two stochastic variables, the protein number and the state of the gene. Each state of the gene behaves as a protein source governed by a Poisson process. The coupling between the two gene states depends on protein number. This fact has a very important implication: There exist protein production regimes characterized by sub-Poissonian noise because of negative covariance between the two stochastic variables of the model. Hence the protein numbers obey a probability distribution that has a peak that is sharper than those of the two coupled Poisson processes that are combined to produce it. Biochemically, the noise reduction in protein number occurs when the switching of the genetic state is more rapid than protein synthesis or degradation. We consider the chemical reaction rates necessary for Poisson and sub-Poisson processes in prokaryotes and eucaryotes. Our results suggest that the coupling of multiple stochastic processes in a negative covariance regime might be a widespread mechanism for noise reduction.

  10. The Reduction of Lunar Regolith by Carbothermal Processing Using Methane

    NASA Technical Reports Server (NTRS)

    Balasubramaniam, R.; Hegde, U.; Gokoglu, S.

    2010-01-01

    The processing of lunar regolith for the production of oxygen is a key component of the In-Situ Resource Utilization plans Currently being developed by NASA. In the carbothermal process, a portion of the surface of the regolith in a container is heated by exposure to a heat source so that a small zone of molten regolith is established. A continuous flow of methane is maintained over the molten regolith zone. In this paper, we discuss the development of a chemical conversion model of the carbothermal process to predict the rate of production of carbon monoxide. Our model is based on a mechanism where methane pyrolyzes when it comes in contact with the surface of the hot molten regolith to form solid carbon and hydrogen gas. Carbon is deposited on the surface of the melt, and hydrogen is released into the gas stream above the melt surface. We assume that the deposited carbon mixes in the molten regolith and reacts with metal oxides in a reduction reaction by which gaseous carbon monoxide is liberated. Carbon monoxide bubbles through the melt and is released into the gas stream. It is further processed downstream to ultimately produce oxygen.

  11. The Reduction of Lunar Regolith by Carbothermal Processing Using Methane

    NASA Technical Reports Server (NTRS)

    Balasubramaniam, R.; Gokoglu, S. A.; Hegde, U.

    2010-01-01

    The processing of lunar regolith for the production of oxygen is a key component of the In-Situ Resource Utilization plans currently being developed by NASA. In the carbothermal process, a portion of the surface of the regolith in a container is heated by exposure to a heat source so that a small zone of molten regolith is established. A continuous flow of methane is maintained over the molten regolith zone. In this paper, we discuss the development of a chemical conversion model of the carbothermal process to predict the rate of production of carbon monoxide. Our model is based on a mechanism where methane pyrolyzes when it comes in contact with the surface of the hot molten regolith to form solid carbon and hydrogen gas. Carbon is deposited on the surface of the melt, and hydrogen is released into the gas stream above the melt surface. We assume that the deposited carbon mixes in the molten regolith and reacts with metal oxides in a reduction reaction by which gaseous carbon monoxide is liberated. Carbon monoxide bubbles through the melt and is released into the gas stream. It is further processed downstream to ultimately produce oxygen.

  12. Reductive stripping process for the recovery of uranium from wet-process phosphoric acid

    DOEpatents

    Hurst, Fred J.; Crouse, David J.

    1984-01-01

    A reductive stripping flow sheet for recovery of uranium from wet-process phosphoric acid is described. Uranium is stripped from a uranium-loaded organic phase by a redox reaction converting the uranyl to uranous ion. The uranous ion is reoxidized to the uranyl oxidation state to form an aqueous feed solution highly concentrated in uranium. Processing of this feed through a second solvent extraction cycle requires far less stripping reagent as compared to a flow sheet which does not include the reductive stripping reaction.

  13. Multistep processing and stress reduction in CVD diamond films

    NASA Astrophysics Data System (ADS)

    Nijhawan, Sumit

    A serious impediment in the utility of diamond films is the large internal stresses that develop during growth. These stresses generally have thermal and growth components. The thermal component is determined by the mismatch in thermal expansion coefficients of film and substrate while the growth component may arise from several possible mechanisms during CVD growth. These growth stresses tend to be particularly large in diamond. The objective of this work is to understand and reduce the growth stresses in diamond films by tailoring the CVD process. Continuous, polycrystalline diamond films were deposited on Si by microwave plasma-assisted CVD. Very high internal stresses (>2 GPA) consisting of growth and thermal components were observed. The growth component is tensile and increases with growth time. We were able to reduce the evolution of growth stresses considerably by multistep processing of our films. An intermediate annealing step was included between successive growth periods. It is important to note that the annealing step must be conducted at key points during the growth process in order to effectively reduce stress. Maximum reduction in stress is achieved only if the sample is annealed when the diamond grains are partially coalesced (after 2--3 hours of growth). Annealing of continuous films does not produce a significant reduction in stress. The origin of growth stress in our films is attributed to non-equilibrated initial atomic positions during impingement and the successive relaxations to minimize interfacial energies. The film quality was monitored using Raman spectroscopy and electron microscopy. Based on our experimental results and analyses, it is hypothesized that rearrangements of strained boundary structures during the anneal can lower the interfacial energy change during subsequent growth and produce less stress. Multistep processing was also used to enhance diamond nucleation on Ni. An annealing pretreatment step, that consists of saturating

  14. Lead removal and toxicity reduction from industrial wastewater through biological sulfate reduction process.

    PubMed

    Teekayuttasakul, Paphungkorn; Annachhatre, Ajit P

    2008-10-01

    The practicability of lead removal from sulfate-rich wastewater through biological sulfate reduction process with hydrogen as electron donor was investigated. Sulfide, which was converted from sulfate by a sulfate-reducing bacteria (SRB) in a gas-lift reactor, was used to remove lead as lead sulfide precipitate. Furthermore, the toxicity of wastewater in terms of whole effluent toxicity (WET) before and after treatment was analyzed by using Microtox analyzer. The experiment was divided into three stages as follows: Stage I, startup and operation of sulfidogenic process fed with synthetic wastewater in a gas-lift reactor; Stage II, operation of sulfidogenic process fed with real wastewater in the same reactor and analysis of toxicity; and Stage III, separation of lead from wastewater. In stage I, the volumetric sulfate-sulfur loading rate was gradually increased from 1.0 g/L.d until no improvement of sulfide-sulfur production efficiency was evident at 2.58 g/L.d and maximum sulfide-sulfur concentration was set to 340 mg/L. In stage II, the results showed that the laboratory scale reactor could treat a real wastewater without inhibition or any remarkable problem. The produced sulfide-sulfur, 200 mg/L, was a little less in comparison with that of the previous stage. It could be due to the higher concentration of total dissolved solid (TDS). However, the sulfate concentration was still reduced by approximately 30%. The WET test by Microtox showed that toxicity was reduced more than 13 times. In stage III, the effluent from the reactor containing sulfide-sulfur of about 200 mg/L and lead-containing solution of 20 mg/L were fed with sulfide to lead ratio 3 moles: 1 mole into the precipitation chamber in which the optimum pH for lead sulfide precipitation of 8.0 was maintained. It was found that lead removal of 99% was attained.

  15. Carbon Dioxide Reduction Post-Processing Sub-System Development

    NASA Technical Reports Server (NTRS)

    Abney, Morgan B.; Miller, Lee A.; Greenwood, Zachary; Barton, Katherine

    2012-01-01

    The state-of-the-art Carbon Dioxide (CO2) Reduction Assembly (CRA) on the International Space Station (ISS) facilitates the recovery of oxygen from metabolic CO2. The CRA utilizes the Sabatier process to produce water with methane as a byproduct. The methane is currently vented overboard as a waste product. Because the CRA relies on hydrogen for oxygen recovery, the loss of methane ultimately results in a loss of oxygen. For missions beyond low earth orbit, it will prove essential to maximize oxygen recovery. For this purpose, NASA is exploring an integrated post-processor system to recover hydrogen from CRA methane. The post-processor, called a Plasma Pyrolysis Assembly (PPA) partially pyrolyzes methane to recover hydrogen with acetylene as a byproduct. In-flight operation of post-processor will require a Methane Purification Assembly (MePA) and an Acetylene Separation Assembly (ASepA). Recent efforts have focused on the design, fabrication, and testing of these components. The results and conclusions of these efforts will be discussed as well as future plans.

  16. Digital Image Processing for Noise Reduction in Medical Ultrasonics

    NASA Astrophysics Data System (ADS)

    Loupas, Thanasis

    Available from UMI in association with The British Library. Requires signed TDF. The purpose of this project was to investigate the application of digital image processing techniques as a means of reducing noise in medical ultrasonic imaging. Ultrasonic images suffer primarily from a type of acoustic noise, known as speckle, which is generally regarded as a major source of image quality degradation. The origin of speckle, its statistical properties as well as methods suggested to eliminate this artifact were reviewed. A simple model which can characterize the statistics of speckle on displays was also developed. A large number of digital noise reduction techniques was investigated. These include frame averaging techniques performed by commercially available devices and spatial filters implemented in software. Among the latter, some filters have been proposed in the scientific literature for ultrasonic, laser and microwave speckle or general noise suppression and the rest are original, developed specifically to suppress ultrasonic speckle. Particular emphasis was placed on adaptive techniques which adjust the processing performed at each point according to the local image content. In this way, they manage to suppress speckle with negligible loss of genuine image detail. Apart from preserving the diagnostically significant features of a scan another requirement a technique must satisfy before it is accepted in routine clinical practice is real-time operation. A spatial filter capable of satisfying both these requirements was designed and built in hardware using low-cost and readily available components. The possibility of incorporating all the necessary filter circuitry into a single VLSI chip was also investigated. In order to establish the effectiveness and usefulness of speckle suppression, a representative sample from the techniques examined here was applied to a large number of abdominal scans and their effect on image quality was evaluated. Finally, further

  17. Oxidation-reduction catalyst and its process of use

    NASA Technical Reports Server (NTRS)

    Jordan, Jeffrey D. (Inventor); Watkins, Anthony Neal (Inventor); Schryer, Jacqueline L. (Inventor); Oglesby, Donald M. (Inventor)

    2008-01-01

    This invention relates generally to a ruthenium stabilized oxidation-reduction catalyst useful for oxidizing carbon monoxide, and volatile organic compounds, and reducing nitrogen oxide species in oxidizing environments, substantially without the formation of toxic and volatile ruthenium oxide species upon said oxidizing environment being at high temperatures.

  18. Deciphering Piperidine Formation in Polyketide-Derived Indolizidines Reveals a Thioester Reduction, Transamination, and Unusual Imine Reduction Process.

    PubMed

    Peng, Haidong; Wei, Erman; Wang, Jiali; Zhang, Yanan; Cheng, Lin; Ma, Hongmin; Deng, Zixin; Qu, Xudong

    2016-12-16

    Piperidine and indolizidine are two basic units of alkaloids that are frequently observed in natural and synthetic compounds. Their biosynthesis in natural products is highly conserved and mostly derived from the incorporation of lysine cyclization products. Through in vitro reconstitution, we herein identified a novel pathway involving a group of polyketide-derived indolizidines, which comprises the processes of tandem two-electron thioester reduction, transamination, and imine reduction to convert acyl carrier protein (ACP)-tethered polyketide chains into the piperidine moieties of their indolizidine scaffolds. The enzymes that catalyze the imine reduction are distinct from previous known imine reductases, which have a fold of acyl-CoA dehydrogenase but do not require flavin for reduction. Our results not only provide a new way for the biosynthesis of the basic units of alkaloids but also show a novel class of imine reductases that may benefit the fields of biocatalysis and biomanufacturing.

  19. Regularized Embedded Multiple Kernel Dimensionality Reduction for Mine Signal Processing.

    PubMed

    Li, Shuang; Liu, Bing; Zhang, Chen

    2016-01-01

    Traditional multiple kernel dimensionality reduction models are generally based on graph embedding and manifold assumption. But such assumption might be invalid for some high-dimensional or sparse data due to the curse of dimensionality, which has a negative influence on the performance of multiple kernel learning. In addition, some models might be ill-posed if the rank of matrices in their objective functions was not high enough. To address these issues, we extend the traditional graph embedding framework and propose a novel regularized embedded multiple kernel dimensionality reduction method. Different from the conventional convex relaxation technique, the proposed algorithm directly takes advantage of a binary search and an alternative optimization scheme to obtain optimal solutions efficiently. The experimental results demonstrate the effectiveness of the proposed method for supervised, unsupervised, and semisupervised scenarios.

  20. Regularized Embedded Multiple Kernel Dimensionality Reduction for Mine Signal Processing

    PubMed Central

    Li, Shuang; Liu, Bing; Zhang, Chen

    2016-01-01

    Traditional multiple kernel dimensionality reduction models are generally based on graph embedding and manifold assumption. But such assumption might be invalid for some high-dimensional or sparse data due to the curse of dimensionality, which has a negative influence on the performance of multiple kernel learning. In addition, some models might be ill-posed if the rank of matrices in their objective functions was not high enough. To address these issues, we extend the traditional graph embedding framework and propose a novel regularized embedded multiple kernel dimensionality reduction method. Different from the conventional convex relaxation technique, the proposed algorithm directly takes advantage of a binary search and an alternative optimization scheme to obtain optimal solutions efficiently. The experimental results demonstrate the effectiveness of the proposed method for supervised, unsupervised, and semisupervised scenarios. PMID:27247562

  1. Process for reduction of volume of contaminated soil by compaction

    SciTech Connect

    Johanan, W.L.

    1994-12-31

    Burial costs for low-level radioactive waste are assessed by the volume of the waste. These costs are presently at $10 per cubic foot and will continue to increase with time. A reduction in waste volume can be directly converted to a reduction in burial costs. A large amount of low-level contaminated soil exists throughout the DOE complex. The Nuclear Complex Modernization Task Force has identified over 5 million cubic feet of contaminated soil for eventual clean-up at the Mound site ($50,000,000 to bury at FY 1991 costs). By using a combination of a rock separator (trommel), crusher, clay soil compactor, automatic loading system, specially designed dust enclosures, and specifically designed containers for both on-site haulage and shipment to the Nevada Test Site (NTS), the total waste volume, and burial cost, can be reduced by up to 30% by compacting the soil into high-density bricks (depending upon the compaction quality of the soil). Several tests have been performed on Mound`s cold on-site soils, with resulting densities of 131 pounds per cubic foot. When this is compared to normal LSA metal box filling of 80--90 pounds per cubic foot, one can readily see the savings.

  2. DESIGNING SUSTAINABLE PROCESSES WITH SIMULATION: THE WASTE REDUCTION (WAR) ALGORITHM

    EPA Science Inventory

    The WAR Algorithm, a methodology for determining the potential environmental impact (PEI) of a chemical process, is presented with modifications that account for the PEI of the energy consumed within that process. From this theory, four PEI indexes are used to evaluate the envir...

  3. Reduction in waste load from a meat processing plant: Beef

    SciTech Connect

    1986-10-31

    ;Contents: Introduction (Randolph Packing Company, Meat Plant Wastewaters, Slaughterhouses, Packing Houses, Sources of Wastewater, Secondary Manufacturing Processes, An Example of Water Conservation and Waste Control, Water Conservation Program); Plant Review and Survey (Survey for Product Losses and Wastes, Water Use and Waste Load, Wastewater Discharge Limitations and Costs); Waste Centers, Changes, Costs and Results (In-Plant Control Measures, Water Conservation, Recovery Products, By-Products and Reducing Waste Load, Blood Conservation, Paunch Handling and Processing, Summary of Process Changes, Pretreatment, Advantages and Disadvantages of Pretreatment, Pretreatment Systems).

  4. INCORPORATING ENVIRONMENTAL AND ECONOMIC CONSIDERATIONS INTO PROCESS DESIGN: THE WASTE REDUCTION (WAR) ALGORITHM

    EPA Science Inventory

    A general theory known as the WAste Reduction (WASR) algorithm has been developed to describe the flow and the generation of potential environmental impact through a chemical process. This theory integrates environmental impact assessment into chemical process design Potential en...

  5. PCDD/PCDF reduction by the co-combustion process.

    PubMed

    Lee, Vinci K C; Cheung, Wai-Hung; McKay, Gordon

    2008-01-01

    A novel process, termed the co-combustion process, has been developed and designed to utilise the thermal treatment of municipal solid waste (MSW) in cement clinker production and reduce PCDD/PCDF emissions. To test the conceptual design; detailed engineering design of the process and equipment was performed and a pilot plant was constructed to treat up to 40 tonnes MSW per day. The novel process features included several units external to the main traditional cement rotary kiln: an external calcinations unit in which the hot gas calcined the limestone thus making significant energy savings for this chemical reaction; the lime generated was used in a second chamber to act as a giant acid gas scrubber to remove SOx and particularly HCl (a source of chloride); an external rotary kiln and secondary combustion unit capable of producing a hot gas at 1200 degrees C; a gas cooler to simulate a boiler turbogenerator set for electricity generation; the incorporation of some of the bottom ash, calcined lime and dust collector solids into the cement clinker. A PCDD/PCDF inventory has been completed for the entire process and measured PCDD/PCDF emissions were 0.001 ng I-TEQ/Nm(3) on average which is 1% of the best practical means [Hong Kong Environmental Protection Department, 2001. A guidance note on the best practicable means for incinerators (municipal waste incineration), BPM12/1] MSW incineration emission limit values.

  6. A POLLUTION REDUCTION METHODOLOGY FOR CHEMICAL PROCESS SIMULATORS

    EPA Science Inventory

    A pollution minimization methodology was developed for chemical process design using computer simulation. It is based on a pollution balance that at steady state is used to define a pollution index with units of mass of pollution per mass of products. The pollution balance has be...

  7. A Non-Aqueous Reduction Process for Purifying 153Gd Produced in Natural Europium Targets

    SciTech Connect

    Johnsen, Amanda M.; Soderquist, Chuck Z.; McNamara, Bruce K.; Fisher, Darrell R.

    2013-08-01

    Gadolinium-153 is a low-energy gamma-emitter used in nuclear medicine imaging quality assurance. Produced in nuclear reactors using natural Eu2O3 targets, 153Gd is radiochemically separated from europium isotopes by europium reduction. However, conventional aqueous europium reduction produces hydrogen gas, a flammability hazard in radiological hot cells. We altered the traditional reduction method, using methanol as the process solvent to nearly eliminate hydrogen gas production. This new, non-aqueous reduction process demonstrates greater than 98% europium removal and gadolinium yields of 90%.

  8. Process for the reduction of nitrogen oxides in an effluent

    SciTech Connect

    Epperly, W.R.; Sullivan, J.C.

    1988-09-13

    A process is described for reducing the concentration of nitrogen oxides in an effluent from the combustion of a carbonaceous fuel, which process comprises injecting into the effluent ammonia and an enhancer selected from the group consisting of hexamethylenetetramine, a lower carbon alcohol, a hydroxyl amino hydrocarbon, sugar, furfural, furfural derivatives, an amino acid, a protein-containing composition, mixtures of ortho-, meta-, and para-methyl phenols, guanidine, guanidine carbonate, biguanidine, guanylurea sulfate, melamine, dicyandiamide, calcium cyanamide, biuret, 1,1'-azobisformamide, methylol urea, methylol urea-urea condensation product, dimethylol urea, methyl urea, dimethyl urea, and mixtures thereof, at an effluent temperature above about 1300/sup 0/F and a molar ratio of nitrogen in the ammonia and enhancer to the baseline nitrogen oxides level of about 1:5 to about 6:1 wherein the excess of oxygen in the effluent is no greater than about 6%.

  9. A pollution reduction methodology for chemical process simulators

    SciTech Connect

    Mallick, S.K.; Cabezas, H.; Bare, J.C.; Sikdar, S.K.

    1996-11-01

    A pollution minimization methodology was developed for chemical process design using computer simulation. It is based on a pollution balance that at steady state is used to define a pollution index with units of mass of pollution per mass of products. The pollution balance has been modified by weighing the mass flowrate of each pollutant by its potential environmental impact score. This converts the mass balance into an environmental impact balance. This balance defines an impact index with units of environmental impact per mass of products. The impact index measures the potential environmental effects of process wastes. Three different schemes for chemical ranking were considered: (1) no ranking, (2) simple ranking from 0 to 3, and (3) ranking by a scientifically derived measure of human health and environmental effects. Use of the methodology is illustrated with two examples from the production of (1) methyl ethyl ketone and (2) synthetic ammonia.

  10. Energy reduction in beet sugar processing by cossette liming

    SciTech Connect

    Randall, J.M.; Camirand, W.M.; Neumann, H.J.

    1981-01-01

    Under appropriate conditions of temperature and fresh Ca(OH)/sub 2/ application, demethylation occurs in the pectin in the cell walls of sugar beet cossettes, allowing Ca/sup 2 +/ to precipitate the pectin as calcium pectate. The calcium pectate will not degrade and pass into solution during subsequent hot extraction of sugar from the cossettes. This retention of pectin in the pulp was shown by 10 to 20% increases in solids weight in the pulp for a number of processing conditions. The toughened pulp produced by retention of calcium pectate allowed easier mechanical dewatering of the pulp which could save considerably on the heat normally required to dry the pulp for cattle feed. Beyond data reported in this paper, there are qualitative indications that the sugar juice extracted from limed cossettes is purer than standard juice, for pectin and colloidal materials remain in the pulp. Thus, much less purification of the juice with lime would be necessary than is required in standard beet-sugar processing, and the current 2% CaO used for purification may be cut almost in half. This represents another energy saving, for production of CaO at the factory is a major consumer of energy. These, along with other possible energy savings resulting from cossette liming (such as less water used for extraction, cold extraction, ion exchange of the purer juice), could produce an overall saving up to 20% of the energy currently used in beet-sugar processing. Some of these possibilities will be further investigated.

  11. Hazard Categorization Reduction via Nature of the Process Argument

    SciTech Connect

    Chelise A. Van De Graaff; Dr. Chad Pope; J. Todd Taylor

    2012-05-01

    This paper documents the Hazard Categorization (HC) and Critical Safety Evaluation (CSE) for activities performed using an Inspection Object (IO) in excess of the single parameter subcritical limit of 700 g of U-235. By virtue of exceeding the single parameter subcritical limit and the subsequent potential for criticality, the IO HC is initially categorized as HC2. However, a novel application of the nature of the process argument was employed to reduce the IO HC from HC2 to less than HC3 (LTHC3). The IO is composed of five separate uranium metal plates that total no greater than 3.82 kg of U-235 (U(20)). The IO is planned to be arranged in various configurations. As the IO serves as a standard for experimentation aimed at establishing techniques for detection of fissionable materials, it may be placed in close proximity to various reflectors, moderators, or both. The most reactive configurations of the IO were systematically evaluated and shown that despite the mass of U-235 and potential positioning near various reflectors and moderators, the IO cannot be assembled into a critical configuration. Therefore, the potential for criticality does not exist. With Department of Energy approval, a Hazards Assessment Document with high-level (facility-level) controls on the plates negates the potential for criticality and satisfies the nature of the process argument to reduce the HC from HC2 to LTHC3.

  12. Reduction in soil aggregation in response to dust emission processes

    NASA Astrophysics Data System (ADS)

    Swet, Nitzan; Katra, Itzhak

    2016-09-01

    Dust emission by aeolian (wind) soil erosion depends on the topsoil properties of the source area, especially on the nature of the aggregates where most dust particles are held. Although the key role of soil aggregates in dust emission, the response of soil aggregation to aeolian processes and its implications for dust emission remain unknown. This study focuses on aggregate size distribution (ASD) analyses before and after in-situ aeolian experiments in semiarid loess soils that are associated with dust emission. Wind tunnel simulations show that particulate matter (PM) emission and saltation rates depend on the initial ASD and shear velocity. Under all initial ASD conditions, the content of saltator-sized aggregates (63-250 μm) increased by 10-34% due to erosion of macro-aggregates (> 500 μm), resulting in a higher size ratio (SR) between the saltators and macro-aggregates following the aeolian erosion. The results revealed that the saltator production increases significantly for soils that are subjected to short-term (anthropogenic) disturbance of the topsoil. The findings highlight a decrease in soil aggregation for all initial ASD's in response to aeolian erosion, and consequently its influence on the dust emission potential. Changes in ASD should be considered as a key parameter in dust emission models of complex surfaces.

  13. Radon Reduction Experience at a Former Uranium Processing Facility

    SciTech Connect

    Eger, K. J.; Rutherford, L.; Rickett, K.; Fellman, R.; Hungate, S.

    2004-02-29

    Approximately 6,200 cubic meters of waste containing about 2.0E8 MBq of radium-226 are stored in two large silos at the Fernald Site in southwest Ohio. The material is scheduled for retrieval, packaging, off site shipment and disposal by burial. Air in the silos above the stored material contained radon-222 at a concentration of 7.4 E5 Bq/L. Short-lived daughters formed by decay in these headspaces generated dose rates at contact with the top of the silos up to 1.05 mSv/hr and there complicate the process of retrieval. A Radon Control System (RCS) employing carbon adsorption beds has been designed under contract with the Fluor Fernald to remove most of the radon in the headspaces and maintain lower concentrations during periods when work on or above the domes is needed. Removing the radon also removes the short-lived daughters and reduces the dose rate near the domes to 20 to 30 {mu}Sv/hr. Failing to remove the radon would be costly, in the exposure of personnel needed to work extended periods at these moderate dose rates, or in dollars for the application of remote retrieval techniques. In addition, the RCS minimizes the potential for environmental releases. This paper describes the RCS, its mode of operation, and early experiences. The results of the test described herein and the experience gained from operation of the RCS during its first phase of continuous operation, will be used to determine the best air flow, and air flow distribution, the most desirable number and sequence number and sequence of adsorption beds to be used and the optimum application of air recycle within the RCS.

  14. Survival in a Down Economy: A Budget Reduction Process for Superintendents

    ERIC Educational Resources Information Center

    Davis, E. E.; Coffland, Jack A.

    2010-01-01

    Dramatic reductions in the dollars available for public education require a new and systemic approach to balancing school district budgets. This manual provides numerous examples of successful budget reduction strategies based on a six-step process that has demonstrated its effectiveness in small, medium, and large school districts. Supported by…

  15. Effect of abiotic factors on the mercury reduction process by humic acids in aqueous systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mercury (Hg) in the environment can have serious toxic effects on a variety of living organisms, and is a pollutant of concern worldwide. The reduction of mercury from the toxic Hg2+ form to Hg0 is especially important. One pathway for this reduction to occur is through an abiotic process with humic...

  16. Oxidation-reduction processes in ground water at Naval Weapons Industrial Reserve Plant, Dallas, Texas

    USGS Publications Warehouse

    Jones, S.A.; Braun, Christopher L.; Lee, Roger W.

    2003-01-01

    Concentrations of trichloroethene in ground water at the Naval Weapons Industrial Reserve Plant in Dallas, Texas, indicate three source areas of chlorinated solvents?building 1, building 6, and an off-site source west of the facility. The presence of daughter products of reductive dechlorination of trichloroethene, which were not used at the facility, south and southwest of the source areas are evidence that reductive dechlorination is occurring. In places south of the source areas, dissolved oxygen concentrations indicated that reduction of oxygen could be the dominant process, particularly south of building 6; but elevated dissolved oxygen concentrations south of building 6 might be caused by a leaking water or sewer pipe. The nitrite data indicate that denitrification is occurring in places; however, dissolved hydrogen concentrations indicate that iron reduction is the dominant process south of building 6. The distributions of ferrous iron indicate that iron reduction is occurring in places south-southwest of buildings 6 and 1; dissolved hydrogen concentrations generally support the interpretation that iron reduction is the dominant process in those places. The generally low concentrations of sulfide indicate that sulfate reduction is not a key process in most sampled areas, an interpretation that is supported by dissolved hydrogen concentrations. Ferrous iron and dissolved hydrogen concentrations indicate that ferric iron reduction is the primary oxidation-reduction process. Application of mean first-order decay rates in iron-reducing conditions for trichloroethene, dichloroethene, and vinyl chloride yielded half-lives for those solvents of 231, 347, and 2.67 days, respectively. Decay rates, and thus half-lives, at the facility are expected to be similar to those computed. A weighted scoring method to indicate sites where reductive dechlorination might be likely to occur indicated strong evidence for anaerobic biodegradation of chlorinated solvents at six sites

  17. GREENER CHEMICAL PROCESS DESIGN ALTERNATIVES ARE REVEALED USING THE WASTE REDUCTION DECISION SUPPORT SYSTEM (WAR DSS)

    EPA Science Inventory

    The Waste Reduction Decision Support System (WAR DSS) is a Java-based software product providing comprehensive modeling of potential adverse environmental impacts (PEI) predicted to result from newly designed or redesigned chemical manufacturing processes. The purpose of this so...

  18. Processes affecting reductive dechlorination of chlorinated solvents by zero-valent iron

    SciTech Connect

    Matheson, L.J.; Tratnyek, P.G.

    1993-12-31

    Zero-valent iron may participate in the reductive dechlorination process by three different mechanisms: direct, electrolytic reduction; reduction by hydrogen produced during the corrosion process; and reduction by dissolved (ferrous) iron that is also produced by corroding iron. The first step of electrolytic reduction is presumably, the transfer of one electron from the metal surface to the organic molecule. This results in an organic anion radical that may then lose a halide anion to give a carbon-centered radical, and oxidized iron, which is eventually released to the solution as Fe{sup 2+}. The goal of this research is to provide a comprehensive survey of the mechanisms that affect the performance of this reactive barrier technology.

  19. Investigation of the reduction process of dopamine using paired pulse voltammetry

    PubMed Central

    Kim, Do Hyoung; Oh, Yoonbae; Shin, Hojin; Blaha, Charles D.; Bennet, Kevin E.; Lee, Kendall H.; Kim, In Young; Jang, Dong Pyo

    2014-01-01

    The oxidation of dopamine (DA) around +0.6V potential in anodic sweep and its reduction around −0.1V in cathodic sweep at a relatively fast scanning rate (300 V/s or greater) have been used for identification of DA oxidation in fast-scan cyclic voltammetry (FSCV). However, compared to the oxidation peak of DA, the reduction peak has not been fully examined in analytical studies, although it has been used as one of the representative features to identify DA. In this study, the reduction process of DA was investigated using paired pulse voltammetry (PPV), which consists of two identical triangle-shaped waveforms, separated by a short interval at the holding potential. Especially, the discrepancies between the magnitude of the oxidation and reduction peaks of DA were investigated based on three factors: (1) the instant desorption of the DA oxidation product (dopamine-o-quinone: DOQ) after production, (2) the effect of the holding potential on the reduction process, and (3) the rate-limited reduction process of DA. For the first test, the triangle waveform FSCV experiment was performed on DA with various scanrates (from 400 to 1000 V/s) and durations of switching potentials of the triangle waveform (from 0.0 to 6.0 ms) in order to vary the duration between the applied oxidation potential at +0.6V and the reduction potential at −0.2V. As a result, the ratio of reduction over oxidation peak current response decreased as the duration became longer. To evaluate the effect of holding potentials during the reduction process, FSCV experiments were conducted with holding potential from 0.0V to −0.8V. We found that more negative holding potentials lead to larger amount of reduction process. For evaluation of the rate-limited reduction process of DA, PPV with a 1Hz repetition rate and various delays (2, 8, 20, 40 and 80ms) between the paired scans were utilized to determine how much reduction process occurred during the holding potential (−0.4V). These tests showed that

  20. Investigation of the reduction process of dopamine using paired pulse voltammetry.

    PubMed

    Kim, Do Hyoung; Oh, Yoonbae; Shin, Hojin; Blaha, Charles D; Bennet, Kevin E; Lee, Kendall H; Kim, In Young; Jang, Dong Pyo

    2014-03-15

    The oxidation of dopamine (DA) around +0.6V potential in anodic sweep and its reduction around -0.1V in cathodic sweep at a relatively fast scanning rate (300 V/s or greater) have been used for identification of DA oxidation in fast-scan cyclic voltammetry (FSCV). However, compared to the oxidation peak of DA, the reduction peak has not been fully examined in analytical studies, although it has been used as one of the representative features to identify DA. In this study, the reduction process of DA was investigated using paired pulse voltammetry (PPV), which consists of two identical triangle-shaped waveforms, separated by a short interval at the holding potential. Especially, the discrepancies between the magnitude of the oxidation and reduction peaks of DA were investigated based on three factors: (1) the instant desorption of the DA oxidation product (dopamine-o-quinone: DOQ) after production, (2) the effect of the holding potential on the reduction process, and (3) the rate-limited reduction process of DA. For the first test, the triangle waveform FSCV experiment was performed on DA with various scanrates (from 400 to 1000 V/s) and durations of switching potentials of the triangle waveform (from 0.0 to 6.0 ms) in order to vary the duration between the applied oxidation potential at +0.6V and the reduction potential at -0.2V. As a result, the ratio of reduction over oxidation peak current response decreased as the duration became longer. To evaluate the effect of holding potentials during the reduction process, FSCV experiments were conducted with holding potential from 0.0V to -0.8V. We found that more negative holding potentials lead to larger amount of reduction process. For evaluation of the rate-limited reduction process of DA, PPV with a 1Hz repetition rate and various delays (2, 8, 20, 40 and 80ms) between the paired scans were utilized to determine how much reduction process occurred during the holding potential (-0.4V). These tests showed that

  1. Void reduction in autoclave processing of thermoset composites. I - High pressure effects on void reduction. II - Void reduction in a microwave curing process

    NASA Astrophysics Data System (ADS)

    Boey, F. Y. C.; Lye, S. W.

    1992-07-01

    Two novel methods for reducing void levels in thermoset composites are reported. The first procedure, which eliminates vacuum application, uses high pressure of up to 7000 kPa, by means of an isostatic press, effectively reducing the void levels to below 3 percent. The second process uses microwave curing by means of a modified approach involving vacuum bagging and applied autoclave pressure. This process achieves a void level of 4 percent.

  2. Mathematical modelling of magnesium reduction in a novel vertical Pidgeon process

    NASA Astrophysics Data System (ADS)

    Yu, Alfred; Hu, Henry; Li, Naiyi

    2002-07-01

    A mathematical model has been developed to simulate the phenomenon of heat transfer occurring during a novel magnesium reduction process - the vertical retort technology. The model was based on the control-volume finite difference approach. The simulations were run to determine the effect of various parameters, such as the diameter and thickness of the compound, and slot angle, on the magnesium reduction cycle time. The model predicted the temperature distributions, the heating curves, and the total process time. The predictions were used to optimize the magnesium reduction process including the dimensions of the retort, shapes of charged materials, and reduction cycle time. The computed results show that the utilization of the optimized process parameters leads to a decrease in reduction time and energy consumption, and an increase in production capacities and recovery rates. Consequently, the magnesium thermal reduction process is significantly improved in the vertical retort. The model has been verified in a demo-plant operation with an annual production capacity of 1200 ton magnesium.

  3. Reduction of Biological Sludge Production Applying an Alternating Oxic/anoxic Process in Water Line.

    PubMed

    Eusebi, Anna Laura; Panigutti, Maximiliano; Battistoni, Paolo

    2016-06-01

    Alternating oxic/anoxic process, applied for the main objective of the improvement of nitrogen performances, was studied in terms of secondary effect of biomass reduction. The process was carried out in one real water resource recovery facility and the data were compared with the previous conventional period when a conventional process was adopted. The main mechanism of the process for the sludge minimization is recognized in the metabolic uncoupling. In fact, an increase of the specific oxygen uptake rate in the biological reactor was recorded stimulated by the change of the oxidation reduction potential environment. Moreover, the heterotrophic growth yield was measured equal to 0.385 kgVSS/kgCOD. The global percentage of reduction was tested with the mass balance of solids. The process is able to decrease the observed sludge yield up to 20%. The specific energy consumption was evaluated.

  4. A modified oxic-settling-anaerobic activated sludge process using gravity thickening for excess sludge reduction

    PubMed Central

    Wang, Jun; Li, Shi-Yu; Jiang, Feng; Wu, Ke; Liu, Guang-Li; Lu, Hui; Chen, Guang-Hao

    2015-01-01

    Oxic-settling-anaerobic process (OSA) was known as a cost-effective way to reduce the excess sludge production with simple upgrade of conventional activated sludge process (CAS). A low oxidation-reduction potential (ORP) level was the key factor to sludge decay and lysis in the sludge holding tank of the OSA process. However, the ORP control with nitrogen purge or chemical dosing in the OSA process would induce extra expense and complicate the operation. Hence, in this study, a sludge holding tank using gravity thickening was applied to OSA process to reduce the excess sludge production without any ORP control. Results showed that the modified OSA process not only reduced the excess sludge production effectively but also improved the sludge settleability without affected the treatment capacity. The reduction of the excess sludge production in the modified OSA process resulted from interactions among lots of factors. The key element of the process was the gravity thickening sludge holding tank. PMID:26350761

  5. A modified oxic-settling-anaerobic activated sludge process using gravity thickening for excess sludge reduction

    NASA Astrophysics Data System (ADS)

    Wang, Jun; Li, Shi-Yu; Jiang, Feng; Wu, Ke; Liu, Guang-Li; Lu, Hui; Chen, Guang-Hao

    2015-09-01

    Oxic-settling-anaerobic process (OSA) was known as a cost-effective way to reduce the excess sludge production with simple upgrade of conventional activated sludge process (CAS). A low oxidation-reduction potential (ORP) level was the key factor to sludge decay and lysis in the sludge holding tank of the OSA process. However, the ORP control with nitrogen purge or chemical dosing in the OSA process would induce extra expense and complicate the operation. Hence, in this study, a sludge holding tank using gravity thickening was applied to OSA process to reduce the excess sludge production without any ORP control. Results showed that the modified OSA process not only reduced the excess sludge production effectively but also improved the sludge settleability without affected the treatment capacity. The reduction of the excess sludge production in the modified OSA process resulted from interactions among lots of factors. The key element of the process was the gravity thickening sludge holding tank.

  6. Modeling and sensitivity analysis study of the reduction of NO sub x by HNCO. [RAPRENOx process

    SciTech Connect

    Brown, N.J.; Garay, J.

    1992-05-01

    A chemical mechanism for the reduction of NO{sub x} by HNCO has been constructed to allow for the modeling of NO{sub x} in exhausts typical of natural gas combustion (RAPRENOx process). The reduction was modeled assuming plug flow, and either isothermal combustion or constant pressure adiabatic combustion. Variables were initial concentrations of NO, NO{sub 2}, CO, CH{sub 4}, H{sub 2}, and HNCO as well as initial temperatures. Exhaust residence time was nominally 1 s. Reduction was not achieved for prototypical natural gas exhaust'' for a reasonable residence time. Radical generation is crucial for reduction. H{sub 2} addition enhanced ignition and reduction. The final combustion temperature determines where NO{sub x} reduction ceases and NO{sub x} production increases. Reduction increases with HNCO, and breakthrough of NH{sub 3} and HNCO increses as well. N{sub 2}O production is due to NCO + NO, but the reduction of NO also occurs through reactions associated with the Thermal De-NOx chemistry. NH{sub 3} production and reactions are important to the reduction of NO. Sensitivity analysis under easy ignition conditions indicated that the same reactions involving nitrogen species, NH{sub 2} and NNH, important in De-NOx, are important when HNCO is used to reduce NO{sub x}. A real combustion exhaust would contain radicals, but it would be neither isothermal nor adiabatic, and heat release and loss would accompany the reduction process. Three-body recombination reactions are important and need further study.(DLC)

  7. Data reduction complex analog-to-digital data processing requirements for onsite test facilities

    NASA Technical Reports Server (NTRS)

    Debbrecht, J. D.

    1976-01-01

    The analog to digital processing requirements of onsite test facilities are described. The source and medium of all input data to the Data Reduction Complex (DRC) and the destination and medium of all output products of the analog-to-digital processing are identified. Additionally, preliminary input and output data formats are presented along with the planned use of the output products.

  8. Possibility of Alternaria toxins reduction by extrusion processing of whole wheat flour.

    PubMed

    Janić Hajnal, Elizabet; Čolović, Radmilo; Pezo, Lato; Orčić, Dejan; Vukmirović, Đuro; Mastilović, Jasna

    2016-12-15

    This study represents the first report about possibility of reduction of Alternaria toxins in wheat using the extrusion process. Effects of extrusion processing parameters - moisture content (w=16, 20, 24g/100g), feeding rate (q=15, 20, 25kg/h), and screw speed (v=300, 390, 480rpm), on reduction rate of tenuazonic acid (TeA), alternariol (AOH) and alternariol monomethyl ether (AME), in whole wheat flour were investigated. Temperature ranged between 111.1 and 160.8°C, while the absolute pressure was from 0.17 to 0.23MPa. The simultaneous influence of w and v was the most important for TeA reduction (p<0.05), while v and q were the most influential for AOH reduction (p<0.01). Level of AME reduction was mostly influenced by w and v (p<0.10). Optimal parameters for reduction of all three Alternaria toxins were as follows: w=24g/100g, q=25kg/h, v=390rpm, with a reduction of 65.6% for TeA, 87.9% for AOH and 94.5% for AME.

  9. Ceruloplasmin copper induces oxidant damage by a redox process utilizing cell-derived superoxide as reductant

    NASA Technical Reports Server (NTRS)

    Mukhopadhyay, C. K.; Fox, P. L.

    1998-01-01

    Oxidative damage by transition metals bound to proteins may be an important pathogenic mechanism. Ceruloplasmin (Cp) is a Cu-containing plasma protein thought to be involved in oxidative modification of lipoproteins. We have previously shown that Cp increased cell-mediated low-density lipoprotein (LDL) oxidation by a process requiring cell-derived superoxide, but the underlying chemical mechanism(s) is (are) unknown. We now show that superoxide reduction of Cp Cu is a critical reaction in cellular LDL oxidation. By bathocuproine disulfonate (BCS) binding and by superoxide utilization, we showed that exogenous superoxide reduces a single Cp Cu atom, the same Cu required for LDL oxidation. The Cu atom remained bound to Cp during the redox cycle. Three avenues of evidence showed that vascular cells reduce Cp Cu by a superoxide-dependent process. The 2-fold higher rate of Cp Cu reduction by smooth muscle cells (SMC) compared to endothelial cells (EC) was consistent with their relative rates of superoxide release. Furthermore, Cp Cu reduction by cells was blocked by Cu,Zn superoxide dismutase (SOD1). Finally, the level of superoxide produced by EC and SMC was sufficient to cause the amount of Cu reduction observed. An important role of Cp Cu reduction in LDL oxidation was suggested by results showing that SOD1 inhibited Cp Cu reduction and LDL oxidation by SMC with equal potency, while tumor necrosis factor-alpha stimulated both processes. In summary, these results show that superoxide is a critical cellular reductant of divalent transition metals involved in oxidation, and that protein-bound Cu is a substrate for this reaction. The role of these mechanisms in oxidative processes in vivo has yet to be defined.

  10. Orbiter data reduction complex data processing requirements for the OFT mission evaluation team (level C)

    NASA Technical Reports Server (NTRS)

    1979-01-01

    This document addresses requirements for post-test data reduction in support of the Orbital Flight Tests (OFT) mission evaluation team, specifically those which are planned to be implemented in the ODRC (Orbiter Data Reduction Complex). Only those requirements which have been previously baselined by the Data Systems and Analysis Directorate configuration control board are included. This document serves as the control document between Institutional Data Systems Division and the Integration Division for OFT mission evaluation data processing requirements, and shall be the basis for detailed design of ODRC data processing systems.

  11. NO x Reduction in the Iron Ore Sintering Process with Flue Gas Recirculation

    NASA Astrophysics Data System (ADS)

    Yu, Zhiyuan; Fan, Xiaohui; Gan, Min; Chen, Xuling; Lv, Wei

    2017-02-01

    Flue gas recirculation (FGR) has been implemented for exhaust gas emissions reduction in iron ore sintering. However, the mechanism of NO x reduction through FGR is still unclear. In this paper, the laboratory pot-grate sintering test showed a 30% reduction in gas flow and 15.51% reduction in NO x emissions achieved with a 30% FGR ratio, and the sinter indexes almost matched those of the conventional process. In the sinter zone, NO-CO catalytic reduction occurs in the range of 500-900°C. When the sinter temperature is 700°C, the highest nitrogen reduction ratio (NRR) achieved is 8%; however, the NO x reduction is inhibited as the post-combustion of CO starts when the temperature increases beyond 700°C. NO x in the flue gas is mainly a product of the fuel combustion in the combustion zone, as the nitrogen conversion rate reaches 50-60%, because the N-containing intermediates exist during the fuel combustion. The existence of NO in the FGR gas inhibits the NO x generation from the fuel combustion, and the NO elimination—through the NO-carbon reaction—is significant in the combustion zone. The NRR in the combustion zone reaches a range of 18-20%.

  12. Comparison of reduction disintegration characteristics of TiO2-rich burdens prepared with sintering process and composite agglomeration process

    NASA Astrophysics Data System (ADS)

    Yu, Zheng-wei; Li, Guang-hui; Liu, Chen; Zhou, Feng; Peng, Zhi-wei; Jiang, Tao

    2016-04-01

    To reveal the impact of the composite agglomeration process (CAP) on the reduction disintegration properties of TiO2-rich ironmaking burden for a blast furnace, the reduction disintegration indices (RDIs), mineral constituents, and microstructure of the products prepared by the CAP and the traditional sintering process (TSP) were investigated. The results showed that, compared to the sinter with a basicity of 2.0 prepared by the TSP, the RDI+6.3 and the RDI+3.15 of the CAP product with the same basicity increased by 28.2wt% and 13.7wt%, respectively, whereas the RDI-0.5 decreased by 2.7wt%. The analysis of the mineral constituents and microstructure of the products indicated that the decreasing titanohematite content decreased the volume expansion during reduction. Meanwhile, the decreasing perovskite content decreased its detrimental effect on the reduction disintegration properties. In addition, the higher silicoferrite of calcium and aluminum (SFCA) content improved the strength of the CAP product. Together, these factors result in an improvement of the RDI of the CAP products. In addition, compared to the sinter, the reduced CAP products clearly contained fewer cracks, which also led to mitigation of reduction disintegration.

  13. Optimization of process for reduction of antinutritional factors in edible cereal brans.

    PubMed

    Kaur, Satinder; Sharma, Savita; Dar, B N; Singh, Baljit

    2012-10-01

    Reduction of various antinutritional factors in cereal brans by different treatments (microwave heating, dry heating and wet heating) were studied. There was significant difference (p ≤ 0.05) in reduction of antinutritional factors of treated cereal brans except for dry heating at low temperature. Microwave heating at 2450 MHz for 2.5 min resulted in 53.85%, 57.21%, 65.00% and 100% reduction in phytic acid, polyphenols, oxalates and saponins, respectively. Wet heating resulted in maximum reduction in trypsin inhibitor activity (83.07%) at 110 °C for 25 min. Processing treatment resulted in increase in bulk density and slight darkening of the brans. The most effective method of detoxifying most of the toxicants was microwave heating for 2.5 min, and therefore it could be exploited for making treated brans an ideal source for potential food application.

  14. A process for the purification of organochlorine contaminated activated carbon: Sequential solvent purging and reductive dechlorination.

    PubMed

    Lee, Matthew; Cord-Ruwisch, Ralf; Manefield, Mike

    2010-03-01

    A system for the purification of organochlorine contaminated activated carbon is described. The system involves a continuous flow of aqueous ethanol to purge organochlorines from activated carbon. The organochlorine laden solvent is simultaneously treated with zero valent zinc as the bulk electron source, water as the proton source and the electron shuttle cyanocobalamin as a catalyst for reductive dechlorination. The system was characterised by performing batch reactions and extractions before being applied in a continuous flow system. In particular the ratio of water to ethanol in the system needed to be optimised. Water is needed for the reductive dechlorination reaction whilst it is not conducive to the extraction process. An 80% ethanolic solution was found to give optimal reductive dechlorination rates without compromising extraction of organochlorines from activated carbon. Of three electron shuttles evaluated cyanocobalamin was discovered to be the most relevant to the system with respect to reductive dechlorination rates and its ability to avoid absorption to activated carbon.

  15. Study on emission characteristics and reduction strategy of nitrous oxide during wastewater treatment by different processes.

    PubMed

    Sun, Shichang; Bao, Zhiyuan; Sun, Dezhi

    2015-03-01

    Given the inexorable increase in global wastewater treatment, increasing amounts of nitrous oxide are expected to be emitted from wastewater treatment plants and released to the atmosphere. It has become imperative to study the emission and control of nitrous oxide in the various wastewater treatment processes currently in use. In the present investigation, the emission characteristics and the factors affecting the release of nitrous oxide were studied via full- and pilot-scale experiments in anoxic-oxic, sequencing batch reactor and oxidation ditch processes. We propose an optimal treatment process and relative strategy for nitrous oxide reduction. Our results show that both the bio-nitrifying and bio-denitrifying treatment units in wastewater treatment plants are the predominant sites for nitrous oxide production in each process, while the aerated treatment units are the critical sources for nitrous oxide emission. Compared with the emission of nitrous oxide from the anoxic-oxic (1.37% of N-influent) and sequencing batch reactor (2.69% of N-influent) processes, much less nitrous oxide (0.25% of N-influent) is emitted from the oxidation ditch process, which we determined as the optimal wastewater treatment process for nitrous oxide reduction, given the current technologies. Nitrous oxide emissions differed with various operating parameters. Controlling the dissolved oxygen concentration at a proper level during nitrification and denitrification and enhancing the utilization rate of organic carbon in the influent for denitrification are the two critical methods for nitrous oxide reduction in the various processes considered.

  16. The impact of the reduction of sodium content in processed foods in salt intake in Brazil.

    PubMed

    Souza, Amanda de Moura; Souza, Bárbara da Silva Nalin de; Bezerra, Ilana Nogueira; Sichieri, Rosely

    2016-02-01

    This study aimed at assessing the potential impact of the reduction of sodium content in processed foods in the average salt intake in the Brazilian population. A total of 32,900 participants of the first National Dietary Survey (NDS 2008-2009), age 10 years and older who provided information about food intake over two days were evaluated. The sodium reduction targets established by the Brazilian Ministry of Health in 2010 and 2013 were used as the reference to determine the maximum content of sodium in 21 groups of processed food. The results show that sodium reduction targets in processed food have small impact in mean Brazilian population intake of salt. For 2017, the expected mean reduction is of 1.5%, the average sodium intake being still above the recommended 2,000mg/day maximum. Therefore, it will hardly be possible to reach the necessary reduction in salt intake in Brazil from volunteer agreements like the ones made so far.

  17. Mineralization of 2-chlorophenol by sequential electrochemical reductive dechlorination and biological processes.

    PubMed

    Arellano-González, Miguel Ángel; González, Ignacio; Texier, Anne-Claire

    2016-08-15

    In this work, a novel approach was applied to obtain the mineralization of 2-chlorophenol (2-CP) in an electrochemical-biological combined system where an electrocatalytic dehydrogenation process (reductive dechlorination) was coupled to a biological denitrification process. Reductive dechlorination of 2-CP was conducted in an ECCOCEL-type reactor on a Pd-Ni/Ti electrode at a potential of -0.40V vs Ag/AgCl(s)/KCl(sat), achieving 100 percent transformation of 2-CP into phenol. The electrochemically pretreated effluent was fed to a rotating cylinder denitrifying bioreactor where the totality of phenol was mineralized by denitrification, obtaining CO2 and N2 as the end products. The total time required for 2-CP mineralization in the combined electrochemical-biological process was 7.5h. This value is close to those previously reported for electrochemical and advanced oxidation processes but in this case, an efficient process was obtained without accumulation of by-products or generation of excessive energy costs due to the selective electrochemical pretreatment. This study showed that the use of electrochemical reductive pretreatment combined with biological processes could be a promising technology for the removal of recalcitrant molecules, such as chlorophenols, from wastewaters by more efficient, rapid, and environmentally friendly processes.

  18. Adaptive sidelobe reduction in SAR and INSAR COSMO-SkyMed image processing

    NASA Astrophysics Data System (ADS)

    Lorusso, Rino; Lombardi, Nunzia; Milillo, Giovanni

    2016-10-01

    The main lobe and the side lobes of strong scatterers are sometimes clearly visible in SAR images. Sidelobe reduction is of particular importance when imaging scenes contain objects such as ships and buildings having very large radar cross sections. Amplitude weighting is usually used to suppress sidelobes of the images at the expense of broadening of mainlobe, loss of resolution and degradation of SAR images. The Spatial Variant Apodization (SVA) is an Adaptive SideLobe Reduction (ASLR) technique that provides high effective suppression of sidelobes without broadening mainlobe. In this paper, we apply SVA to process COSMO-SkyMed (CSK) StripMap and Spotlight X-band data and compare the images with the standard products obtained via Hamming window processing. Different test sites have been selected in Italy, Argentina, California and Germany where corner reflectors are installed. Experimental results show clearly the resolution improvement (20%) while sidelobe kept to a low level when SVA processing is applied compared with Hamming windowing one. Then SVA technique is applied to Interferometric SAR image processing (INSAR) using a CSK StripMap interferometric tandem-like data pair acquired on East-California. The interferometric coherence of image pair obtained without sidelobe reduction (SCS_U) and with sidelobe reduction performed via Hamming window and via SVA are compared. High resolution interferometric products have been obtained with small variation of mean coherence when using ASLR products with respect to hamming windowed and no windowed one.

  19. ECO LOGIC INTERNATIONAL GAS-PHASE CHEMICAL REDUCTION PROCESS - THE THERMAL DESORPTION UNIT - APPLICATIONS ANALYSIS REPORT

    EPA Science Inventory

    ELI ECO Logic International, Inc.'s Thermal Desorption Unit (TDU) is specifically designed for use with Eco Logic's Gas Phase Chemical Reduction Process. The technology uses an externally heated bath of molten tin in a hydrogen atmosphere to desorb hazardous organic compounds fro...

  20. A MIXED CHEMICAL REDUCTANT FOR TREATING HEXAVALENT CHROMIUM IN A CHROMITE ORE PROCESSING SOLID WASTE

    EPA Science Inventory

    We evaluated a method for delivering ferrous iron into the subsurface to enhance chemical reduction of Cr(VI) in a chromite ore processing solid waste (COPSW). The COPSW is characterized by high pH (8.5 -11.5), high Cr(VI) concentrations in the solid phase (up to 550 mg kg-1) and...

  1. User's guide to the UTIL-ODRC tape processing program. [for the Orbital Data Reduction Center

    NASA Technical Reports Server (NTRS)

    Juba, S. M. (Principal Investigator)

    1981-01-01

    The UTIL-ODRC computer compatible tape processing program, its input/output requirements, and its interface with the EXEC 8 operating system are described. It is a multipurpose orbital data reduction center (ODRC) tape processing program enabling the user to create either exact duplicate tapes and/or tapes in SINDA/HISTRY format. Input data elements for PRAMPT/FLOPLT and/or BATCH PLOT programs, a temperature summary, and a printed summary can also be produced.

  2. Modelling of the nitric acid reduction process: Application to materials behavior in reprocessing plants

    SciTech Connect

    Sicsic, D.; Balbaud-Celerier, F.; Tribollet, B.

    2012-07-01

    In France, the recycling process of nuclear waste fuels involves the use of hot concentrated nitric acid. The understanding and the prediction of the structural materials (mainly austenitic stainless steels) behaviour requires the determination of the nitric acid reduction process. Nitric acid is indirectly reduced by an autocatalytic mechanism depending on the cathodic overpotential and the acid concentration. This mechanism has been widely studied. All the authors agree on its autocatalytic nature, characterized by the predominant role of the reduction products. It is also generally admitted that nitric acid or the nitrate ion are not the electro-active species. However, uncertainties remain concerning the nature of the electro-active species, the place where the catalytic species regenerates and the thermodynamic and kinetic behaviour of the reaction intermediates. The aim of this study is to clarify some of these uncertainties by performing an electrochemical investigation of the 4 mol.L -1 nitric acid reduction process at 40 deg. C occurring on an inert electrode (platinum or gold). An inert electrode was chosen as a working electrode in a first step in order to avoid its oxidation and focus the research on the reduction mechanism. This experimental work enabled to suggest a coherent sequence of electrochemical and chemical reactions. Then, a kinetic modelling of this sequence was carried out for a gold rotating disk system. In this objective, a thermodynamic study at 25 deg. C led to the evaluation of the composition of liquid and gaseous phases for nitric acid solutions from 0.5 to 22 mol.L -1. The kinetics of the reduction process of nitric acid 4 mol.L -1 was investigated by cyclic voltammetry and chrono-amperometry on an inert electrode at 40 deg. C. A coupling of chrono-amperometry and FTIR in gaseous phase led to the identification of the gaseous reduction products as a function of the cathodic overpotential. These different results showed that for

  3. Reaction engineering for materials processing in space: Reduction of ilmenite by hydrogen and carbon monoxide

    NASA Technical Reports Server (NTRS)

    Zhao, Y.; Shadman, F.

    1991-01-01

    Oxygen is a consumable material which needs to be produced continuously in most space missions. Its use for propulsion as well as life support makes oxygen one of the largest volume chemicals to be produced in space. Production of oxygen from lunar materials is of particular interest and is very attractive possibility. The kinetics and mechanism of reduction of ilmenite by carbon monoxide and hydrogen at 800 to 1100 C were investigated. The temporal profiles of conversion for carbon monoxide have a sigmoidal shape and indicate the presence of three different stages (induction, acceleration, and deceleration) during the reduction reaction. The apparent activation energy decreases from 18 kcal/mole at 10 percent conversion to 10 kcal/mole at 50 percent conversion. The reaction is first order with respect to carbon monoxide under the experimental conditions studied. Both SEM and EDX analysis show that the diffusion of Fe product away from the reaction front and through the TiO2 phase, followed by the nucleation and growth of a separate Fe phase are important steps affecting the process kinetics. The results from hydrogen reduction show that the mechanism of ilmenite reduction by hydrogen is similar to that by carbon monoxide. However, the titanium dioxide can be further reduced by hydrogen at 800 to 1000 C. The detailed comparison and theoretical modeling of both reduction processes is presented.

  4. Study on the oxidation and reduction of tungsten surface for sub-50 nm patterning process

    SciTech Connect

    Kim, Jong Kyu; Nam, Seok Woo; Cho, Sung Il; Jhon, Myung S.; Min, Kyung Suk; Kim, Chan Kyu; Jung, Ho Bum; Yeom, Geun Young

    2012-11-15

    The oxidation characteristics of tungsten line pattern during the carbon-based mask-layer removal process using oxygen plasmas have been investigated for sub-50 nm patterning processes, in addition to the reduction characteristics of the WO{sub x} layer formed on the tungsten line surface using hydrogen plasmas. The surface oxidation of tungsten lines during the mask layer removal process could be minimized by using low-temperature (300 K) plasma processing for the removal of the carbon-based material. Using this technique, the thickness of WO{sub x} on the tungsten line could be decreased to 25% compared to results from high-temperature processing. The WO{sub x} layer could also be completely removed at a low temperature of 300 K using a hydrogen plasma by supplying bias power to the tungsten substrate to provide a activation energy for the reduction. When this oxidation and reduction technique was applied to actual 40-nm-CD device processing, the complete removal of WO{sub x} formed on the sidewall of tungsten line could be observed.

  5. Numerical Study of the Reduction Process in an Oxygen Blast Furnace

    NASA Astrophysics Data System (ADS)

    Zhang, Zongliang; Meng, Jiale; Guo, Lei; Guo, Zhancheng

    2016-02-01

    Based on computational fluid dynamics, chemical reaction kinetics, principles of transfer in metallurgy, and other principles, a multi-fluid model for a traditional blast furnace was established. The furnace conditions were simulated with this multi-fluid mathematical model, and the model was verified with the comparison of calculation and measurement. Then a multi-fluid model for an oxygen blast furnace in the gasifier-full oxygen blast furnace process was established based on this traditional blast furnace model. With the established multi-fluid model for an oxygen blast furnace, the basic characteristics of iron ore reduction process in the oxygen blast furnace were summarized, including the changing process of the iron ore reduction degree and the compositions of the burden, etc. The study found that compared to the traditional blast furnace, the magnetite reserve zone in the furnace shaft under oxygen blast furnace condition was significantly reduced, which is conducive to the efficient operation of blast furnace. In order to optimize the oxygen blast furnace design and operating parameters, the iron ore reduction process in the oxygen blast furnace was researched under different shaft tuyere positions, different recycling gas temperatures, and different allocation ratios of recycling gas between the hearth tuyere and the shaft tuyere. The results indicate that these three factors all have a substantial impact on the ore reduction process in the oxygen blast furnace. Moderate shaft tuyere position, high recycling gas temperature, and high recycling gas allocation ratio between hearth and shaft could significantly promote the reduction of iron ore, reduce the scope of the magnetite reserve zone, and improve the performance of oxygen blast furnace. Based on the above findings, the recommendations for improvement of the oxygen blast furnace design and operation were proposed.

  6. Dimension reduction of multivariable optical emission spectrometer datasets for industrial plasma processes.

    PubMed

    Yang, Jie; McArdle, Conor; Daniels, Stephen

    2013-12-19

    A new data dimension-reduction method, called Internal Information Redundancy Reduction (IIRR), is proposed for application to Optical Emission Spectroscopy (OES) datasets obtained from industrial plasma processes. For example in a semiconductor manufacturing environment, real-time spectral emission data is potentially very useful for inferring information about critical process parameters such as wafer etch rates, however, the relationship between the spectral sensor data gathered over the duration of an etching process step and the target process output parameters is complex. OES sensor data has high dimensionality (fine wavelength resolution is required in spectral emission measurements in order to capture data on all chemical species involved in plasma reactions) and full spectrum samples are taken at frequent time points, so that dynamic process changes can be captured. To maximise the utility of the gathered dataset, it is essential that information redundancy is minimised, but with the important requirement that the resulting reduced dataset remains in a form that is amenable to direct interpretation of the physical process. To meet this requirement and to achieve a high reduction in dimension with little information loss, the IIRR method proposed in this paper operates directly in the original variable space, identifying peak wavelength emissions and the correlative relationships between them. A new statistic, Mean Determination Ratio (MDR), is proposed to quantify the information loss after dimension reduction and the effectiveness of IIRR is demonstrated using an actual semiconductor manufacturing dataset. As an example of the application of IIRR in process monitoring/control, we also show how etch rates can be accurately predicted from IIRR dimension-reduced spectral data.

  7. Corrosion Testing of Monofrax K-3 Refractory in Defense Waste Processing Facility (DWPF) Alternate Reductant Feeds

    SciTech Connect

    Williams, M.; Jantzen, C.; Burket, P.

    2016-04-06

    The Defense Waste Processing Facility (DWPF) at the Savannah River Site (SRS) uses a combination of reductants and oxidants while converting high level waste (HLW) to a borosilicate waste form. A reducing flowsheet is maintained to retain radionuclides in their reduced oxidation states which promotes their incorporation into borosilicate glass. For the last 20 years of processing, the DWPF has used formic acid as the main reductant and nitric acid as the main oxidant. During reaction in the Chemical Process Cell (CPC), formate and formic acid release measurably significant H2 gas which requires monitoring of certain vessel’s vapor spaces. A switch to a nitric acid-glycolic acid (NG) flowsheet from the nitric-formic (NF) flowsheet is desired as the NG flowsheet releases considerably less H2 gas upon decomposition. This would greatly simplify DWPF processing from a safety standpoint as close monitoring of the H2 gas concentration could become less critical. In terms of the waste glass melter vapor space flammability, the switch from the NF flowsheet to the NG flowsheet showed a reduction of H2 gas production from the vitrification process as well. Due to the positive impact of the switch to glycolic acid determined on the flammability issues, evaluation of the other impacts of glycolic acid on the facility must be examined.

  8. Brushing Your Spacecrafts Teeth: A Review of Biological Reduction Processes for Planetary Protection Missions

    NASA Technical Reports Server (NTRS)

    Pugel, D.E. (Betsy); Rummel, J. D.; Conley, C. A.

    2017-01-01

    Much like keeping your teeth clean, where you brush away biofilms that your dentist calls plaque, there are various methods to clean spaceflight hardware of biological contamination, known as biological reduction processes. Different approaches clean your hardwares teeth in different ways and with different levels of effectiveness. We know that brushing at home with a simple toothbrush is convenient and has a different level of impact vs. getting your teeth cleaned at the dentist. In the same way, there are some approaches to biological reduction that may require simple tools or more complex implementation approaches (think about sonicating or just soaking your dentures, vs. brushing them). There are also some that are more effective for different degrees of cleanliness and still some that have materials compatibility concerns. In this article, we review known and NASA-certified approaches for biological reduction, pointing out materials compatibility concerns and areas where additional research is needed.

  9. Brushing Your Spacecrafts Teeth: A Review of Biological Reduction Processes for Planetary Protection Missions

    NASA Technical Reports Server (NTRS)

    Pugel, D. E. (Betsy); Rummel, J. D.; Conley, Catharine

    2017-01-01

    Much like keeping your teeth clean, where you brush away biofilms that your dentist calls "plaque," there are various methods to clean spaceflight hardware of biological contamination, known as biological reduction processes. Different approaches clean your hardware's "teeth" in different ways and with different levels of effectiveness. We know that brushing at home with a simple toothbrush is convenient and has a different level of impact vs. getting your teeth cleaned at the dentist. In the same way, there are some approaches to biological reduction that may require simple tools or more complex implementation approaches (think about sonicating or just soaking your dentures, vs. brushing them). There are also some that are more effective for different degrees of cleanliness and still some that have materials compatibility concerns. In this article, we review known and NASA-certified approaches for biological reduction, pointing out materials compatibility concerns and areas where additional research is needed.

  10. Sulfur Isotopes as Indicators of Bacterial Sulfate Reduction Processes Influencing Field Scale Uranium Bioremediation

    NASA Astrophysics Data System (ADS)

    Druhan, J. L.; Conrad, M. E.; Williams, K. H.; N'guessan, L.; Long, P. E.; Hubbard, S. S.

    2007-12-01

    An in-situ acetate amendment at a DOE Uranium Mill Tailings Remedial Action (UMTRA) site near Rifle, CO demonstrated successful reduction of aqueous U(VI), to less soluble U(IV) through stimulated microbial activity. U(VI) reduction rates were highest during iron reduction and decreased with the onset of sulfate reduction. However, sustained U(IV) attenuation was observed following subsequent termination of the acetate amendment. These findings illustrate the importance of the transition between iron and sulfate reducing conditions in stimulating bioreduction of uranium. The sulfur isotope compositions of sulfate and sulfide were measured through this transition in order to explore the utility of these data in tracking the extent of microbial sulfate reduction and to assess the stability of sulfide precipitates. Samples for isotopic analyses and aqueous measurements of sulfate, ferrous iron, U(VI) and acetate were collected in one background well and three monitoring wells down-gradient of the acetate injection. Results show an increase of up to 7‰ in the δ34S of sulfate at the onset of sulfate reduction, followed by a return to background δ34S values of -8‰ following cessation of the acetate amendment. The δ34S values of sulfide increased from roughly -20‰ at the onset of sulfate reduction to a maximum of -0.8‰ during peak sulfate removal, followed by a gradual return to values of roughly -28‰ upon cessation of the acetate amendment. These data present a unique perspective on the processes governing the bioreduction experiment in that the sulfate isotopes are a function of both transport and mixing processes, whereas the sulfide isotopes represent biogenic sulfide that is rapidly removed from the aqueous phase. Thus a comparable enrichment in sulfate isotopic data noted in the closest and furthest wells from the injection gallery suggest bioreduction in both of these locations, while a larger increase in sulfide isotopic values in the closest well

  11. Selective catalytic reduction system and process using a pre-sulfated zirconia binder

    DOEpatents

    Sobolevskiy, Anatoly; Rossin, Joseph A.

    2010-06-29

    A selective catalytic reduction (SCR) process with a palladium catalyst for reducing NOx in a gas, using hydrogen as a reducing agent is provided. The process comprises contacting the gas stream with a catalyst system, the catalyst system comprising (ZrO.sub.2)SO.sub.4, palladium, and a pre-sulfated zirconia binder. The inclusion of a pre-sulfated zirconia binder substantially increases the durability of a Pd-based SCR catalyst system. A system for implementing the disclosed process is further provided.

  12. Influence of physical and chemical aquifer heterogeneity on nitrate reduction processes by numerical simulations

    NASA Astrophysics Data System (ADS)

    Kalbacher, T.; Jang, E.; He, W.; Savoy, H.; Schueth, C.; Kolditz, O.

    2015-12-01

    Nitrate reduction reactions, as one of the most important redox reactions in a subsurface system, are strongly influenced by various heterogeneity factors which influence transport of chemical species and spatial distribution of redox substances and consequently have an effect on overall nitrate reduction capacity. In this presented work, the influence of two heterogeneity factors, spatially heterogeneity of hydrological parameters versus spatial heterogeneity of geochemical reactive substances distribution, are discussed with a focus on nitrate transport and redox transformation processes. For this purpose, a coupling interface OGS#IPhreeqc is employed. This code combines Finite-Element groundwater flow and multi-species transport code of OpenGeoSys (OGS) with the IPhreeqc module of open source geochemical solver PHREEQC. The resulting coupled model is applied for simulation of nitrate reduction processes with a series of hypothetical aquifer systems, built using exponentially-correlated log-normal distributed hydraulic conductivity and reactive substances. The spatially heterogeneous aquifer system is realized by a RandomFields package using a statistical program R. Results show that the heterogeneous hydraulics conductivity field has larger impact on nitrate reduction capacity than heterogeneous reactive substances distribution. Moreover, nitrate reduction capacity can be increased by enhanced mixing in heterogeneous hydraulic conductivity field however its overall reduction capacity has gradually decreased as a degree of heterogeneity has increased since accessibility of the chemical species by the reactive substances may be limited. These results support that appropriate characterization of the variance of hydraulic conductivity within the aquifer is important to predict contaminant fate and transport and quantify the impact of uncertainty on numerical groundwater simulation.

  13. Ochratoxin A reduction in meat sausages using processing methods practiced in households.

    PubMed

    Pleadin, Jelka; Perši, Nina; Kovačević, Dragan; Vulić, Ana; Frece, Jadranka; Markov, Ksenija

    2014-01-01

    The aim of this study was to investigate the possibilities of ochratoxin A (OTA) reduction in home-made meat products. Meat sausages (n = 50) produced from raw materials coming from pigs exposed to OTA-contaminated feed, were subject to common heat processes practiced in households (cooking, frying and baking). Concentrations of OTA in pre- and post-processed products were quantified using a validated immunoassay method, enzyme-linked immunosorbent assay, and confirmed using a high-performance liquid chromatography with fluorescence detection. In line with the differences in recipes used and the degree of OTA accumulation in raw materials, OTA concentrations established in Mediterranean and roast sausages were lower than those found in liver and blood sausages. Baking of contaminated sausages at the temperatures of 190-220°C (for 60 min) resulted in significant reduction of OTA levels (75.8%), while 30-min cooking (at 100°C) and frying (at 170°C) proved to be significantly less effective (e.g. yielding OTA reductions of 7.4% and 12.6%, respectively). The results pointed out that despite high OTA stability, heat processes are capable of reducing its concentration in home-made meat products, depending on the processing modality used.

  14. Westinghouse Modular Grinding Process - Enhancement of Volume Reduction for Hot Resin Supercompaction - 13491

    SciTech Connect

    Fehrmann, Henning; Aign, Joerg

    2013-07-01

    In nuclear power plants (NPP) ion exchange (IX) resins are used in several systems for water treatment. Spent resins can contain a significant amount of contaminates which makes treatment for disposal of spent resins mandatory. Several treatment processes are available such as direct immobilization with technologies like cementation, bitumisation, polymer solidification or usage of a high integrity container (HIC). These technologies usually come with a significant increase in final waste volume. The Hot Resin Supercompaction (HRSC) is a thermal treatment process which reduces the resin waste volume significantly. For a mixture of powdered and bead resins the HRSC process has demonstrated a volume reduction of up to 75 % [1]. For bead resins only the HRSC process is challenging because the bead resins compaction properties are unfavorable. The bead resin material does not form a solid block after compaction and shows a high spring back effect. The volume reduction of bead resins is not as good as for the mixture described in [1]. The compaction properties of bead resin waste can be significantly improved by grinding the beads to powder. The grinding also eliminates the need for a powder additive.Westinghouse has developed a modular grinding process to grind the bead resin to powder. The developed process requires no circulation of resins and enables a selective adjustment of particle size and distribution to achieve optimal results in the HRSC or in any other following process. A special grinding tool setup is use to minimize maintenance and radiation exposure to personnel. (authors)

  15. The relative importance of microbial nitrate reduction processes in an agriculturally-impacted estuary

    NASA Astrophysics Data System (ADS)

    Cardarelli, E.; Francis, C. A.

    2013-12-01

    Human activities are increasing reactive nitrogen levels worldwide. Reactive nitrogen exists largely as nitrate and may be ecologically harmful to nutrient-limited systems. Nitrate loadings to the environment may be transformed by the microbial nitrate reduction processes of denitrification (converting nitrate to dinitrogen gas), or of dissimilatory nitrate reduction to ammonium (DNRA) (allowing reactive nitrogen to persist). The predominant nitrate reduction pathway largely determines the nitrogen removal capacity of the estuary. Therefore, identifying the relative importance of denitrification and DNRA in a given system provides insight into how much nitrate is transformed to dinitrogen and ammonium. Estuary sediments often have high nitrate reduction rates, but the environmental factors that determine which process prevails are underexplored. Nitrate availability and salinity are thought to influence which nitrate reduction process predominates. Elkhorn Slough is a small California estuary that experiences a range of nitrate concentrations (0 to over 2,000 μM) and salinities (0 to 33.5) depending on the agricultural runoff introduced through the Old Salinas River and the tidal influence. This study investigates how the fluctuating nutrient and salinity conditions found over the diel cycle at the interface of the Old Salinas River and Elkhorn Slough influences the nitrogen transformation rates observed. Benthic denitrification and DNRA are evaluated using whole sediment core incubations amended with an overlying 15NO3- labeled pool. Rates of denitrification and DNRA in the sediment are calculated using the isotope pairing technique. The results of this research will help elucidate the relative importance of dissimilatory nitrate removal pathways in an agriculturally-impacted estuary and ultimately reveal whether anthropogenic nitrate inputs are preserved or removed from the system.

  16. Dissimilatory nitrate reduction processes in sediments of urban river networks: Spatiotemporal variations and environmental implications.

    PubMed

    Cheng, Lv; Li, Xiaofei; Lin, Xianbiao; Hou, Lijun; Liu, Min; Li, Ye; Liu, Sai; Hu, Xiaoting

    2016-12-01

    Urbanizations have increased the loadings of reactive nitrogen in urban riverine environments. However, limited information about dissimilatory nitrate reduction processes and associated contributions to nitrogen removal is available for urban riverine environments. In this study, sediment slurry experiments were conducted with nitrogen isotope-tracing technique to investigate the potential rates of denitrification, anaerobic ammonium oxidation (anammox) and dissimilatory nitrate reduction to ammonium (DNRA) and their contributions to nitrate reduction in sediments of urban river networks, Shanghai. The potential rates of denitrification, anammox and DNRA measured in the study area ranged from 0.193 to 98.7 nmol N g(-1) h(-1) dry weight (dw), 0.0387-23.7 nmol N g(-1) h(-1) dw and 0-10.3 nmol N g(-1) h(-1) dw, respectively. Denitrification and DNRA rates were higher in summer than in winter, while anammox rates were greater in winter than in summer for most sites. Dissolved oxygen, total organic carbon, nitrate, ammonium, sulfide, Fe(II) and Fe(III) were found to have significant influence on these nitrate reduction processes. Denitrification contributed 11.5-99.5%% to total nitrate reduction, as compared to 0.343-81.6% for anammox and 0-52.3% for DNRA. It is estimated that nitrogen loss of approximately 1.33 × 10(5) t N year(-1) was linked to both denitrification and anammox processes, which accounted for about 20.1% of total inorganic nitrogen transported annually into the urban river networks of Shanghai. Overall, these results show the potential importance of denitrification and anammox in nitrogen removal and provide new insight into the mechanisms of nitrogen cycles in urban riverine environments.

  17. Synthesis of Hierarchical Nanoporous Microstructures via the Kirkendall Effect in Chemical Reduction Process

    PubMed Central

    Gao, Ling; Pang, Chao; He, Dafang; Shen, Liming; Gupta, Arunava; Bao, Ningzhong

    2015-01-01

    A series of novel hierarchical nanoporous microstructures have been synthesized through one-step chemical reduction of micron size Cu2O and Co3O4 particles. By controlling the reduction time, non-porous Cu2O microcubes sequentially transform to nanoporous Cu/Cu2O/Cu dented cubic composites and hollow eightling-like Cu microparticles. The mechanism involved in the complex structural evolution is explained based on oxygen diffusion and Kirkendall effect. The nanoporous Cu/Cu2O/Cu dented cubic composites exhibit superior electrochemical performance as compared to solid Cu2O microcubes. The reduction of nonporous Co3O4 also exhibits a uniform sequential reduction process from nonporous Co3O4 to porous Co3O4/CoO composites, porous CoO, porous CoO/Co composites, and porous foam-like Co particles. Nanoscale channels originate from the particle surface and eventually develop inside the entire product, resulting in porous foam-like Co microparticles. The Kirkendall effect is believed to facilitate the formation of porous structures in both processes. PMID:26552845

  18. Development Of Chemical Reduction And Air Stripping Processes To Remove Mercury From Wastewater

    SciTech Connect

    Jackson, Dennis G.; Looney, Brian B.; Craig, Robert R.; Thompson, Martha C.; Kmetz, Thomas F.

    2013-07-10

    This study evaluates the removal of mercury from wastewater using chemical reduction and air stripping using a full-scale treatment system at the Savannah River Site. The existing water treatment system utilizes air stripping as the unit operation to remove organic compounds from groundwater that also contains mercury (C ~ 250 ng/L). The baseline air stripping process was ineffective in removing mercury and the water exceeded a proposed limit of 51 ng/L. To test an enhancement to the existing treatment modality a continuous dose of reducing agent was injected for 6-hours at the inlet of the air stripper. This action resulted in the chemical reduction of mercury to Hg(0), a species that is removable with the existing unit operation. During the injection period a 94% decrease in concentration was observed and the effluent satisfied proposed limits. The process was optimized over a 2-day period by sequentially evaluating dose rates ranging from 0.64X to 297X stoichiometry. A minimum dose of 16X stoichiometry was necessary to initiate the reduction reaction that facilitated the mercury removal. Competing electron acceptors likely inhibited the reaction at the lower 1 doses, which prevented removal by air stripping. These results indicate that chemical reduction coupled with air stripping can effectively treat large-volumes of water to emerging part per trillion regulatory standards for mercury.

  19. Synthesis of Hierarchical Nanoporous Microstructures via the Kirkendall Effect in Chemical Reduction Process

    NASA Astrophysics Data System (ADS)

    Gao, Ling; Pang, Chao; He, Dafang; Shen, Liming; Gupta, Arunava; Bao, Ningzhong

    2015-11-01

    A series of novel hierarchical nanoporous microstructures have been synthesized through one-step chemical reduction of micron size Cu2O and Co3O4 particles. By controlling the reduction time, non-porous Cu2O microcubes sequentially transform to nanoporous Cu/Cu2O/Cu dented cubic composites and hollow eightling-like Cu microparticles. The mechanism involved in the complex structural evolution is explained based on oxygen diffusion and Kirkendall effect. The nanoporous Cu/Cu2O/Cu dented cubic composites exhibit superior electrochemical performance as compared to solid Cu2O microcubes. The reduction of nonporous Co3O4 also exhibits a uniform sequential reduction process from nonporous Co3O4 to porous Co3O4/CoO composites, porous CoO, porous CoO/Co composites, and porous foam-like Co particles. Nanoscale channels originate from the particle surface and eventually develop inside the entire product, resulting in porous foam-like Co microparticles. The Kirkendall effect is believed to facilitate the formation of porous structures in both processes.

  20. Impacts of natural organic matter on perchlorate removal by an advanced reduction process.

    PubMed

    Duan, Yuhang; Batchelor, Bill

    2014-01-01

    Perchlorate can be destroyed by Advanced Reduction Processes (ARPs) that combine chemical reductants (e.g., sulfite) with activating methods (e.g., UV light) in order to produce highly reactive reducing free radicals that are capable of rapid and effective perchlorate reduction. However, natural organic matter (NOM) exists widely in the environment and has the potential to influence perchlorate reduction by ARPs that use UV light as the activating method. Batch experiments were conducted to obtain data on the impacts of NOM and wavelength of light on destruction of perchlorate by the ARPs that use sulfite activated by UV light produced by low-pressure mercury lamps (UV-L) or by KrCl excimer lamps (UV-KrCl). The results indicate that NOM strongly inhibits perchlorate removal by both ARP, because it competes with sulfite for UV light. Even though the absorbance of sulfite is much higher at 222 nm than that at 254 nm, the results indicate that a smaller amount of perchlorate was removed with the UV-KrCl lamp (222 nm) than with the UV-L lamp (254 nm). The results of this study will help to develop the proper way to apply the ARPs as practical water treatment processes.

  1. Deoxygenative C-C Bond-Forming Processes via a Net Four-Electron Reductive Coupling.

    PubMed

    Todd, David P; Thompson, Benjamin B; Nett, Alex J; Montgomery, John

    2015-10-14

    The nickel-catalyzed coupling of enones or enals with alkynes in the presence of silane and titanium alkoxide reductants provides direct access to skipped diene products. The process involves a net four-electron reductive coupling and proceeds with deoxygenation of the starting enone or enal. A new class of well-defined nickel(0) precatalysts bearing an unhindered N-heterocyclic carbene ligand, which was developed in optimization of the process, is essential for the efficiency of the transformation. The strategy allows the high reactivity of α,β-unsaturated carbonyl substrates to be utilized in couplings with simultaneous extrusion of the oxygen atom, thus enabling a traceless strategy for alkene installation.

  2. Microbial community in anoxic-oxic-settling-anaerobic sludge reduction process revealed by 454 pyrosequencing analysis.

    PubMed

    Ning, Xinqiang; Qiao, Wenwen; Zhang, Lei; Gao, Xu

    2014-12-01

    Modification of the anoxic-oxic (AO) process by inserting a sludge holding tank (SHT) into the sludge return line forms an anoxic-oxic-settling-anaerobic (A+OSA) process that can achieve a 48.98% sludge reduction rate. The 454 pyrosequencing method was used to obtain the microbial communities of the AO and A+OSA processes. Results showed that the microbial community structures of the 2 processes were different as a result of the SHT insertion. Bacteria assigned to the phyla Proteobacteria and Bacteroidetes commonly existed and dominated the microbial populations of the 2 processes. However, the relative abundance of these populations shifted in the presence of SHT. The relative abundance of Proteobacteria decreased during the A+OSA process. A specific comparison at the class level showed that Sphingobacteria was enriched in the A+OSA process. The result suggested that the fermentative bacteria Sphingobacteria may have key functions in reducing the sludge from the A+OSA process. Uncultured Nitrosomonadaceae gradually became the dominant ammonia-oxidizing bacteria, and the nitrite-oxidizing bacterium Nitrospira was enriched in the A+OSA process. Both occurrences were favorable for stabilized nitrogen removal. The known denitrifying species in the A+OSA process were similar to those in the AO process; however, their relative abundance also decreased.

  3. Processing Time Reduction: an Application in Living Human High-Resolution Diffusion Magnetic Resonance Imaging Data.

    PubMed

    Lori, Nicolás F; Ibañez, Augustin; Lavrador, Rui; Fonseca, Lucia; Santos, Carlos; Travasso, Rui; Pereira, Artur; Rossetti, Rosaldo; Sousa, Nuno; Alves, Victor

    2016-11-01

    High Angular Resolution Diffusion Imaging (HARDI) is a type of brain imaging that collects a very large amount of data, and if many subjects are considered then it amounts to a big data framework (e.g., the human connectome project has 20 Terabytes of data). HARDI is also becoming increasingly relevant for clinical settings (e.g., detecting early cerebral ischemic changes in acute stroke, and in pre-clinical assessment of white matter-WM anatomy using tractography). Thus, this method is becoming a routine assessment in clinical settings. In such settings, the computation time is critical, and finding forms of reducing the processing time in high computation processes such as Diffusion Spectrum Imaging (DSI), a form of HARDI data, is very relevant to increase data-processing speed. Here we analyze a method for reducing the computation time of the dMRI-based axonal orientation distribution function h by using Monte Carlo sampling-based methods for voxel selection. Results evidenced a robust reduction in required data sampling of about 50 % without losing signal's quality. Moreover, we show that the convergence to the correct value in this type of Monte Carlo HARDI/DSI data-processing has a linear improvement in data-processing speed of the ODF determination. Although further improvements are needed, our results represent a promissory step for future processing time reduction in big data.

  4. NO sub x reduction by the Econ-Nox trademark SCR process

    SciTech Connect

    Hardison, L.C.; Nagl, G.J.; Addison, G.E. )

    1991-11-01

    SCR systems are used extensively in Japan and West Germany to eliminate 80-90% NO{sub x} emissions from utility boilers and industrial furnace stacks. Costs have been lowered considerably over the past ten years. Further reduced costs and stringent regulations on NO{sub x} emission make this simple system attractive for refinery and industrial process heaters, boilers, and gas turbines. The Econ-Nox{trademark} process uses a fluidized catalyst bed to accomplish selective total reduction of oxides of nitrogen to elemental nitrogen using ammonia as a reactant. The process can be designed for operating temperatures between 550 F and 750 F and for a wide range of operating variables. The process brings together some old technology on selective reduction chemistry, relatively new fluidized bed oxidation techniques and a non-precious metal Econ-Acat{trademark} catalyst which permits operation over a broader temperature range than has been practical in the past. This paper reports some of the distinctions made between this reactor configuration and the historical thermal and catalytic systems used for this type of process.

  5. Monte Carlo simulations of safeguards neutron counter for oxide reduction process feed material

    NASA Astrophysics Data System (ADS)

    Seo, Hee; Lee, Chaehun; Oh, Jong-Myeong; An, Su Jung; Ahn, Seong-Kyu; Park, Se-Hwan; Ku, Jeong-Hoe

    2016-10-01

    One of the options for spent-fuel management in Korea is pyroprocessing whose main process flow is the head-end process followed by oxide reduction, electrorefining, and electrowining. In the present study, a well-type passive neutron coincidence counter, namely, the ACP (Advanced spent fuel Conditioning Process) safeguards neutron counter (ASNC), was redesigned for safeguards of a hot-cell facility related to the oxide reduction process. To this end, first, the isotopic composition, gamma/neutron emission yield and energy spectrum of the feed material ( i.e., the UO2 porous pellet) were calculated using the OrigenARP code. Then, the proper thickness of the gammaray shield was determined, both by irradiation testing at a standard dosimetry laboratory and by MCNP6 simulations using the parameters obtained from the OrigenARP calculation. Finally, the neutron coincidence counter's calibration curve for 100- to 1000-g porous pellets, in consideration of the process batch size, was determined through simulations. Based on these simulation results, the neutron counter currently is under construction. In the near future, it will be installed in a hot cell and tested with spent fuel materials.

  6. A Mathematical Model for the Reduction Stage of the CAS-OB Process

    NASA Astrophysics Data System (ADS)

    Sulasalmi, Petri; Visuri, Ville-Valtteri; Kärnä, Aki; Järvinen, Mika; Ollila, Seppo; Fabritius, Timo

    2016-12-01

    This paper proposes a novel method for modeling the reduction stage of the CAS-OB process (composition adjustment by sealed argon bubbling-oxygen blowing). Our previous study proposed a model for the heating stage of the CAS-OB process; the purpose of the present study is to extend this work toward a more comprehensive model for the process in question. The CAS-OB process is designed for homogenization and control of the composition and temperature of steel. During the reduction stage, the steel phase is stirred intensely by employing the gas nozzles at the bottom of the ladle, which blow argon gas. It is assumed that the reduction rate of the top slag is dictated by the formation of slag droplets at the steel-slag interface. Slag droplets, which are generated due to turning of the steel flow in the spout, contribute mainly by increasing the interfacial area between the steel and slag phases. This phenomenon has been taken into account based on our previous study, in which the droplet size distribution and generation rate at different steel flow velocities. The reactions considered between the slag and steel phases are assumed to be mass transfer controlled and reversible. We validated the results from the model against the measurements from the real CAS-OB process. The results indicate that the model accurately predicts the end compositions of slag and steel. Moreover, it was discovered that the cooling rate of steel during the gas stirring given by the model is consistent with the results reported in the literature.

  7. Nutritional impact of sodium reduction strategies on sodium intake from processed foods

    PubMed Central

    Hendriksen, M A H; Verkaik-Kloosterman, J; Noort, M W; van Raaij, J M A

    2015-01-01

    Background/objectives: Sodium intake in the Netherlands is substantially above the recommended intake of 2400 mg/day. This study aimed to estimate the effect of two sodium reduction strategies, that is, modification of the composition of industrially processed foods toward the technologically feasible minimum level or alteration of consumers' behavior on sodium intake in the Netherlands. Subjects/methods: Data from the Dutch National Food Consumption Survey (2007–2010) and the Food Composition Table (2011) were used to estimate the current sodium intake. In the first scenario, levels in processed foods were reduced toward their technologically feasible minimum level (sodium reduction in processed foods scenario). The minimum feasible levels were based on literature searches or expert judgment. In the second scenario, foods consumed were divided into similar food (sub)groups. Subsequently, foods were replaced by low-sodium alternatives (substitution of processed foods scenario). Sodium intake from foods was calculated based on the mean of two observation days for the current food consumption pattern and the scenarios. Results: Sodium levels of processed foods could be reduced in most food groups by 50%, and this may reduce median sodium intake from foods by 38% (from 3042 to 1886 mg/day in adult men). Substitution of foods may reduce sodium intake by 47% (from 3042 to 1627 mg/day in adult men), owing to many low-sodium alternatives within food groups. Conclusions: In the Netherlands, reduction of sodium intake by modification of food composition or by alteration of behavior may substantially reduce the median sodium intake from foods below the recommended sodium intake. PMID:25782426

  8. Environmental guideline for the reduction of volatile organic compound emissions from the plastics processing industry

    SciTech Connect

    1997-12-31

    The purpose of this document is to provide guidance to environmental regulatory agencies, manufacturers, and operators of plastics processing plants regarding the means of reducing emissions containing volatile organic compounds (VOCs) which are released to the environment in the course of production. Sectors covered by the guideline are expanded polystyrene, cellular polyethylene foams, polyvinyl chloride, and reinforced plastics and composites made from thermoset polyester resins. The guideline focuses on the reduction of VOC emissions from processing and clean-up operations, the handling and storage of VOC-containing materials, and the handling and disposal of wastes. The guideline contains material, equipment, process, and operating standards for plastics processing facilities, record keeping and training standards, recommended operating practices, and testing protocols.

  9. METHANE de-NOX process as a NO{sub x} reduction technology for stoker boilers

    SciTech Connect

    Rabovitser, I.; Roberts, M.; Chan, I.; Loviska, T.; Morrow, R.; Bonner, T.; Hall, D.

    1996-12-31

    The most common NO{sub x} control technology utilized in stokers is selective noncatalytic reduction (SNCR) systems. The natural gas industry has developed the patented METHANE de-NOX reburning process for stokers to reduce NO{sub x} emissions to the levels set by current EPA regulations without increasing the levels of other undesirable emissions. In contrast to conventional reburning, where the reburn fuel is injected above the combustion zone to create a fuel-rich reburn zone, with METHANE de-NOX, natural gas is injected directly into the combustion zone above the grate; this results in a reduction of NO{sub x} formed in the coal bed and also limits its formation through decomposition of the NO{sub x} precursors to form molecular nitrogen rather than nitrogen oxides. The METHANE de-NOX process was field tested at the Olmsted County waste-to-energy facility in Rochester, Minnesota, and at an incineration plant in Japan. Compared to baseline levels, about 60% NO{sub x} reduction and an increase in boiler efficiency were achieved. IGT, Detroit Stoker Company, and Cogentrix are presently demonstrating the METHANE de-NOX technology on a coal-fired 390 MM Btu/h stoker boiler at a 240 MW cogeneration plant in Richmond, Virginia. Baseline tests were conducted which indicated that 50 to 60% NO{sub x} can be reduced by utilization of METHANE de-NOX.

  10. Thermo-Mechanical Behavior of the Continuous Casting Bloom in the Heavy Reduction Process

    NASA Astrophysics Data System (ADS)

    Ji, Cheng; Wu, Chen-hui; Zhu, Miao-yong

    2016-12-01

    A two-stage sequential heavy reduction (HR) method, in which the reduction amount was increased both before and after the solidification end, is presented to simultaneously improve the homogeneity and compactness of the continuous casting bloom. With bearing steel GCr15 chosen as the specific research steel, a three-dimensional thermal-mechanical finite element model was developed to simulate and analyze the thermal and mechanical behaviors of the continuous casting bloom during the HR process. In order to ensure the accuracy of the simulation, the constitutive model parameters were derived from the experimental results. The predicted temperature distribution and shell thickness were verified using a thermal infrared camera and nail shooting results, respectively. The real measured relationship between the HR pressure and amount were applied to verify the mechanical model. The explorative application results showed that the quality of the bloom center and compactness of rolled bars have both been significantly improved after the HR was applied.

  11. Interim glycol flowsheet reduction/oxidation (redox) model for the Defense Waste Processing Facility (DWPF)

    SciTech Connect

    Jantzen, C. M.; Williams, M. S.; Zamecnik, J. R.; Missimer, D. M.

    2016-03-08

    Control of the REDuction/OXidation (REDOX) state of glasses containing high concentrations of transition metals, such as High Level Waste (HLW) glasses, is critical in order to eliminate processing difficulties caused by overly reduced or overly oxidized melts. Operation of a HLW melter at Fe+2/ΣFe ratios of between 0.09 and 0.33, a range which is not overly oxidizing or overly reducing, helps retain radionuclides in the melt, i.e. long-lived radioactive 99Tc species in the less volatile reduced Tc4+ state, 104Ru in the melt as reduced Ru+4 state as insoluble RuO2, and hazardous volatile Cr6+ in the less soluble and less volatile Cr+3 state in the glass. The melter REDOX control balances the oxidants and reductants from the feed and from processing additives such as antifoam. Currently, the Defense Waste Processing Facility (DWPF) is running a formic acid-nitric acid (FN) flowsheet where formic acid is the main reductant and nitric acid is the main oxidant. During decomposition formate and formic acid releases H2 gas which requires close control of the melter vapor space flammability. A switch to a nitric acid-glycolic acid (GN) flowsheet is desired as the glycolic acid flowsheet releases considerably less H2 gas upon decomposition. This would greatly simplify DWPF processing. Development of an EE term for glycolic acid in the GN flowsheet is documented in this study.

  12. Recharge processes drive sulfate reduction in an alluvial aquifer contaminated with landfill leachate

    USGS Publications Warehouse

    Scholl, M.A.; Cozzarelli, I.M.; Christenson, S.C.

    2006-01-01

    present in the root zone, and SO42- reduction may be coupled to methane oxidation. The results show that sulfur (and possibly nitrogen) redox processes within the top 2??m of the aquifer are directly related to recharge timing and seasonal water level changes in the aquifer. The results suggest that SO42- reduction associated with the infiltration of recharge may be a significant factor affecting natural attenuation of contaminants in alluvial aquifers. ?? 2006 Elsevier B.V. All rights reserved.

  13. Removal of PCBs in contaminated soils by means of chemical reduction and advanced oxidation processes.

    PubMed

    Rybnikova, V; Usman, M; Hanna, K

    2016-09-01

    Although the chemical reduction and advanced oxidation processes have been widely used individually, very few studies have assessed the combined reduction/oxidation approach for soil remediation. In the present study, experiments were performed in spiked sand and historically contaminated soil by using four synthetic nanoparticles (Fe(0), Fe/Ni, Fe3O4, Fe3 - x Ni x O4). These nanoparticles were tested firstly for reductive transformation of polychlorinated biphenyls (PCBs) and then employed as catalysts to promote chemical oxidation reactions (H2O2 or persulfate). Obtained results indicated that bimetallic nanoparticles Fe/Ni showed the highest efficiency in reduction of PCB28 and PCB118 in spiked sand (97 and 79 %, respectively), whereas magnetite (Fe3O4) exhibited a high catalytic stability during the combined reduction/oxidation approach. In chemical oxidation, persulfate showed higher PCB degradation extent than hydrogen peroxide. As expected, the degradation efficiency was found to be limited in historically contaminated soil, where only Fe(0) and Fe/Ni particles exhibited reductive capability towards PCBs (13 and 18 %). In oxidation step, the highest degradation extents were obtained in presence of Fe(0) and Fe/Ni (18-19 %). The increase in particle and oxidant doses improved the efficiency of treatment, but overall degradation extents did not exceed 30 %, suggesting that only a small part of PCBs in soil was available for reaction with catalyst and/or oxidant. The use of organic solvent or cyclodextrin to improve the PCB availability in soil did not enhance degradation efficiency, underscoring the strong impact of soil matrix. Moreover, a better PCB degradation was observed in sand spiked with extractable organic matter separated from contaminated soil. In contrast to fractions with higher particle size (250-500 and <500 μm), no PCB degradation was observed in the finest fraction (≤250 μm) having higher organic matter content. These findings

  14. Simple Process for the Reduction in the Nucleic Acid Content in Yeast

    PubMed Central

    Zee, J. A.; Simard, R. E.

    1975-01-01

    A simple one-step process for the nucleic acid reduction in Rhodotorula glutinis is described. The process consists of submitting the yeast cells to a heat treatment in an acidic (pH 2) spent medium. The optimal temperature for pH 2 medium is 90 C and the final nucleic acid content in treated yeasts was 1.2%. Heat treatment at acidic pH is preferred to that at alkaline pH because it offers a better protection for amino acids and crude protein, while being more efficient in lowering the nucleic acid level. The new process is economic and rapid and could be easily used for industrial application. PMID:234157

  15. Chemical treatment of plutonium with hydrogen peroxide before nitrate anion exchange processing. [Reduction to (IV)

    SciTech Connect

    Marsh, S.F.; Gallegos, T.D.

    1987-05-01

    The major aqueous process used to recover and purify plutonium at the Los Alamos Plutonium Facility is anion exchange in nitric acid. This process is highly selective for plutonium; however, all plutonium must be as Pu(IV) to form the strongly sorbed anionic nitrato complex. The previous ''full-reduction treatment'' used at Los Alamos to obtain Pu(IV) results in a three- to fourfold increase in the feed solution volume and the introduction of kilogram quantities of extraneous salts immediately before a process whose function is to remove such impurities. That treatment has been successfully replaced by a single reagent, hydrogen peroxide, which converts all plutonium to Pu(IV), minimally increases the feed volume, and introduces no residual impurities. Safety aspects of this revised chemical treatment are addressed.

  16. Reduction of chromium in Ni-base superalloys through element substitution and rapid solidification processing

    NASA Technical Reports Server (NTRS)

    Fraser, H. D.; Muddl, B. C.

    1982-01-01

    The reduction in the use of Cr in Ni base superalloys by the combined approaches of both elemental substitution and rapid solidification processing is studied. The elements Si, Zr, Y and Hf were chosen as potential partial substitutes for Cr in Waspaloy and IN 713LC sine their separate addition to other alloys has previously resulted in enhanced oxidation resistance. The roles of Cr and these replacement elements in determining the microstructure and properties are evaluated. The elements Si, Zr, and Y and Hf are used as partial replacements for Cr in the base superalloys and these resultant alloys are processed using rapid solidification techniques. The mechanical properties and oxidation resistance of the processed materials are evaluated. The microstructure is characterized using state of the art techniques (e.g. analytical transmission electron microscopy), and the mechanism by which these structures are produced is determined.

  17. Reduction of antibiotic resistance genes in municipal wastewater effluent by advanced oxidation processes.

    PubMed

    Zhang, Yingying; Zhuang, Yao; Geng, Jinju; Ren, Hongqiang; Xu, Ke; Ding, Lili

    2016-04-15

    This study investigated the reduction of antibiotic resistance genes (ARGs), intI1 and 16S rRNA genes, by advanced oxidation processes (AOPs), namely Fenton oxidation (Fe(2+)/H2O2) and UV/H2O2 process. The ARGs include sul1, tetX, and tetG from municipal wastewater effluent. The results indicated that the Fenton oxidation and UV/H2O2 process could reduce selected ARGs effectively. Oxidation by the Fenton process was slightly better than that of the UV/H2O2 method. Particularly, for the Fenton oxidation, under the optimal condition wherein Fe(2+)/H2O2 had a molar ratio of 0.1 and a H2O2 concentration of 0.01molL(-1) with a pH of 3.0 and reaction time of 2h, 2.58-3.79 logs of target genes were removed. Under the initial effluent pH condition (pH=7.0), the removal was 2.26-3.35 logs. For the UV/H2O2 process, when the pH was 3.5 with a H2O2 concentration of 0.01molL(-1) accompanied by 30min of UV irradiation, all ARGs could achieve a reduction of 2.8-3.5 logs, and 1.55-2.32 logs at a pH of 7.0. The Fenton oxidation and UV/H2O2 process followed the first-order reaction kinetic model. The removal of target genes was affected by many parameters, including initial Fe(2+)/H2O2 molar ratios, H2O2 concentration, solution pH, and reaction time. Among these factors, reagent concentrations and pH values are the most important factors during AOPs.

  18. Reduction of overestimation in interval arithmetic simulation of biological wastewater treatment processes

    NASA Astrophysics Data System (ADS)

    Rauh, Andreas; Kletting, Marco; Aschemann, Harald; Hofer, Eberhard P.

    2007-02-01

    A novel interval arithmetic simulation approach is introduced in order to evaluate the performance of biological wastewater treatment processes. Such processes are typically modeled as dynamical systems where the reaction kinetics appears as additive nonlinearity in state. In the calculation of guaranteed bounds of state variables uncertain parameters and uncertain initial conditions are considered. The recursive evaluation of such systems of nonlinear state equations yields overestimation of the state variables that is accumulating over the simulation time. To cope with this wrapping effect, innovative splitting and merging criteria based on a recursive uncertain linear transformation of the state variables are discussed. Additionally, re-approximation strategies for regions in the state space calculated by interval arithmetic techniques using disjoint subintervals improve the simulation quality significantly if these regions are described by several overlapping subintervals. This simulation approach is used to find a practical compromise between computational effort and simulation quality. It is pointed out how these splitting and merging algorithms can be combined with other methods that aim at the reduction of overestimation by applying consistency techniques. Simulation results are presented for a simplified reduced-order model of the reduction of organic matter in the activated sludge process of biological wastewater treatment.

  19. Persistence and effect of processing on reduction of chlorpyriphos residues in okra fruits.

    PubMed

    Samriti; Chauhan, Reena; Kumari, Beena

    2011-08-01

    Residue levels of chlorpyriphos were determined in unprocessed and processed okra fruits to evaluate the effect of different processes (washing and washing followed by boiling/cooking) on reduction of residues of this pesticide in okra. The study was carried out on okra crop (Variety, Varsha Uphar) in research farm of Chaudhary Charan Singh, Haryana Agricultural University, Hisar with application of chlorpyriphos (Radar 20 EC) at 200 g a.i./ha and 400g a.i./ha (Single Dose, T(1)) and 400 g a.i./ha (Double Dose, T(2)). Samples of okra fruits were collected on 0, 1, 3, 5, 7, 10, 15 days and at harvest after treatment. Residues were estimated by GC-ECD system and reached BDL of 0.010 mg kg(-1) on 7th and 15th day in case of single and double dose, respectively. The residues dissipated with half-life period of 3.15 days at lower dose and 3.46 days at higher dose following biphasic first order kinetics. Processing was found very effective in reducing the levels of chlorpyriphos residues in okra fruits. Maximum reduction (64-77%) was observed by washing + boiling followed by washing (13-35%).

  20. Decontamination and size reduction of plutonium contaminated process exhaust ductwork and glove boxes

    SciTech Connect

    LaFrate, P.; Elliott, J.; Valasquez, M.

    1996-11-15

    The Los Alamos National Laboratory (LANL) Decommissioning Program has decontaminated and demolished two filter plenum buildings at Technical Area 21 (TA-21). During the project a former hot cell was retrofitted to perform decontamination and size reduction of highly Pu contaminated process exhaust (1,100 ft) and gloveboxes. Pu-238/239 concentrations were as high a 1 Ci per linear foot and averaged approximately 1 mCi/ft. The Project decontamination objective was to reduce the plutonium contamination on surfaces below transuranic levels. If possible, metal surfaces were decontaminated further to meet Science and Ecology Group (SEG) waste classification guidelines to enable the metal to be recycled at their facility in oak Ridge, Tennessee. Project surface contamination acceptance criteria for low-level radioactive waste (LLRW), transuranic waste, and SEG waste acceptance criteria will be presented. Ninety percent of all radioactive waste for the project was characterized as LLRW. Twenty percent of this material was shipped to SEG. Process exhaust and glove boxes were brought to the project decontamination area, an old hot cell in Building 4 North. This paper focuses on process exhaust and glovebox decontamination methodology, size reduction techniques, waste characterization, airborne contamination monitoring, engineering controls, worker protection, lessons learned, and waste minimization. Decontamination objectives are discussed in detail.

  1. IMPACTS OF ANTIFOAM ADDITIONS AND ARGON BUBBLING ON DEFENSE WASTE PROCESSING FACILITY REDUCTION/OXIDATION

    SciTech Connect

    Jantzen, C.; Johnson, F.

    2012-06-05

    During melting of HLW glass, the REDOX of the melt pool cannot be measured. Therefore, the Fe{sup +2}/{Sigma}Fe ratio in the glass poured from the melter must be related to melter feed organic and oxidant concentrations to ensure production of a high quality glass without impacting production rate (e.g., foaming) or melter life (e.g., metal formation and accumulation). A production facility such as the Defense Waste Processing Facility (DWPF) cannot wait until the melt or waste glass has been made to assess its acceptability, since by then no further changes to the glass composition and acceptability are possible. therefore, the acceptability decision is made on the upstream process, rather than on the downstream melt or glass product. That is, it is based on 'feed foward' statistical process control (SPC) rather than statistical quality control (SQC). In SPC, the feed composition to the melter is controlled prior to vitrification. Use of the DWPF REDOX model has controlled the balanjce of feed reductants and oxidants in the Sludge Receipt and Adjustment Tank (SRAT). Once the alkali/alkaline earth salts (both reduced and oxidized) are formed during reflux in the SRAT, the REDOX can only change if (1) additional reductants or oxidants are added to the SRAT, the Slurry Mix Evaporator (SME), or the Melter Feed Tank (MFT) or (2) if the melt pool is bubble dwith an oxidizing gas or sparging gas that imposes a different REDOX target than the chemical balance set during reflux in the SRAT.

  2. Effects of imposed salinity gradients on dissimilatory arsenate reduction, sulfate reduction, and other microbial processes in sediments from two California soda lakes.

    PubMed

    Kulp, T R; Han, S; Saltikov, C W; Lanoil, B D; Zargar, K; Oremland, R S

    2007-08-01

    Salinity effects on microbial community structure and on potential rates of arsenate reduction, arsenite oxidation, sulfate reduction, denitrification, and methanogenesis were examined in sediment slurries from two California soda lakes. We conducted experiments with Mono Lake and Searles Lake sediments over a wide range of salt concentrations (25 to 346 g liter(-1)). With the exception of sulfate reduction, rates of all processes demonstrated an inverse relationship to total salinity. However, each of these processes persisted at low but detectable rates at salt saturation. Denaturing gradient gel electrophoresis analysis of partial 16S rRNA genes amplified from As(V) reduction slurries revealed that distinct microbial populations grew at low (25 to 50 g liter(-1)), intermediate (100 to 200 g liter(-1)), and high (>300 g liter(-1)) salinity. At intermediate and high salinities, a close relative of a cultivated As-respiring halophile was present. These results suggest that organisms adapted to more dilute conditions can remain viable at high salinity and rapidly repopulate the lake during periods of rising lake level. In contrast to As reduction, sulfate reduction in Mono Lake slurries was undetectable at salt saturation. Furthermore, sulfate reduction was excluded from Searles Lake sediments at any salinity despite the presence of abundant sulfate. Sulfate reduction occurred in Searles Lake sediment slurries only following inoculation with Mono Lake sediment, indicating the absence of sulfate-reducing flora. Experiments with borate-amended Mono Lake slurries suggest that the notably high (0.46 molal) concentration of borate in the Searles Lake brine was responsible for the exclusion of sulfate reducers from that ecosystem.

  3. Effects of imposed salinity gradients on dissimilatory arsenate reduction, sulfate reduction, and other microbial processes in sediments from two California soda lakes

    USGS Publications Warehouse

    Kulp, T.R.; Han, S.; Saltikov, C.W.; Lanoil, B.D.; Zargar, K.; Oremland, R.S.

    2007-01-01

    Salinity effects on microbial community structure and on potential rates of arsenate reduction, arsenite oxidation, sulfate reduction, denitrification, and methanogenesis were examined in sediment slurries from two California soda lakes. We conducted experiments with Mono Lake and Searles Lake sediments over a wide range of salt concentrations (25 to 346 g liter-1). With the exception of sulfate reduction, rates of all processes demonstrated an inverse relationship to total salinity. However, each of these processes persisted at low but detectable rates at salt saturation. Denaturing gradient gel electrophoresis analysis of partial 16S rRNA genes amplified from As(V) reduction slurries revealed that distinct microbial populations grew at low (25 to 50 g liter-1), intermediate (100 to 200 g liter-1), and high (>300 g liter-1) salinity. At intermediate and high salinities, a close relative of a cultivated As-respiring halophile was present. These results suggest that organisms adapted to more dilute conditions can remain viable at high salinity and rapidly repopulate the lake during periods of rising lake level. In contrast to As reduction, sulfate reduction in Mono Lake slurries was undetectable at salt saturation. Furthermore, sulfate reduction was excluded from Searles Lake sediments at any salinity despite the presence of abundant sulfate. Sulfate reduction occurred in Searles Lake sediment slurries only following inoculation with Mono Lake sediment, indicating the absence of sulfate-reducing flora. Experiments with borate-amended Mono Lake slurries suggest that the notably high (0.46 molal) concentration of borate in the Searles Lake brine was responsible for the exclusion of sulfate reducers from that ecosystem. Copyright ?? 2007, American Society for Microbiology. All Rights Reserved.

  4. A non-aqueous reduction process for purifying ¹⁵³Gd produced in natural europium targets.

    PubMed

    Johnsen, Amanda M; Soderquist, Chuck Z; McNamara, Bruce K; Fisher, Darrell R

    2013-12-01

    Gadolinium-153 is a low-energy gamma-emitter used in nuclear medicine imaging quality assurance. Produced in nuclear reactors using natural Eu₂O₃ targets, ¹⁵³Gd is radiochemically separated from europium isotopes by europium reduction. However, conventional aqueous europium reduction produces hydrogen gas, a flammability hazard in radiological hot cells. We altered the traditional reduction method, using methanol as the process solvent to nearly eliminate hydrogen gas production. This new, non-aqueous reduction process demonstrates greater than 98% europium removal and gadolinium yields of 90%.

  5. Analysis of civilian processing programs in reduction of excess separated plutonium and high-enriched uranium

    SciTech Connect

    Persiani, P.J.

    1995-12-31

    The purpose of this preliminary investigation is to explore alternatives and strategies aimed at the gradual reduction of the excess inventories of separated plutonium and high-enriched uranium (HEU) in the civilian nuclear power industry. The study attempts to establish a technical and economic basis to assist in the formation of alternative approaches consistent with nonproliferation and safeguards concerns. The analysis addresses several options in reducing the excess separated plutonium and HEU, and the consequences on nonproliferation and safeguards policy assessments resulting from the interacting synergistic effects between fuel cycle processes and isotopic signatures of nuclear materials.

  6. Advanced sewage treatment process with excess sludge reduction and phosphorus recovery.

    PubMed

    Saktaywin, W; Tsuno, H; Nagare, H; Soyama, T; Weerapakkaroon, J

    2005-03-01

    An advanced sewage treatment process has been developed, in which excess sludge reduction by ozonation and phosphorus recovery by crystallization process are incorporated to a conventional anaerobic/oxic (A/O) phosphorus removal process. The mathematical model was developed to describe the mass balance principal at a steady state of this process. Sludge ozonation experiments were carried out to investigate solubilization characteristics of sludge and change in microbial activity by using sludge cultured with feed of synthetic sewage under A/O process. Phosphorus was solubilized by ozonation as well as organics, and acid-hydrolyzable phosphorus (AHP) was the most part of solubilized phosphorus for phosphorus accumulating organisms (PAOs) containing sludge. At solubilization of 30%, around 70% of sludge was inactivated by ozonation. The results based on these studies indicated that the proposed process configuration has potential to reduce the excess sludge production as well as to recover phosphorus in usable forms. The system performance results show that this system is practical, in which 30% of solubilization degree was achieved by ozonation. In this study, 30% of solubilization was achieved at 30 mgO(3)/gSS of ozone consumption.

  7. Identifying the influential aquifer heterogeneity factor on nitrate reduction processes by numerical simulation

    NASA Astrophysics Data System (ADS)

    Jang, E.; He, W.; Savoy, H.; Dietrich, P.; Kolditz, O.; Rubin, Y.; Schüth, C.; Kalbacher, T.

    2017-01-01

    Nitrate reduction reactions in groundwater systems are strongly influenced by various aquifer heterogeneity factors that affect the transport of chemical species, spatial distribution of redox reactive substances and, as a result, the overall nitrate reduction efficiency. In this study, we investigated the influence of physical and chemical aquifer heterogeneity, with a focus on nitrate transport and redox transformation processes. A numerical modeling study for simulating coupled hydrological-geochemical aquifer heterogeneity was conducted in order to improve our understanding of the influence of the aquifer heterogeneity on the nitrate reduction reactions and to identify the most influential aquifer heterogeneity factors throughout the simulation. Results show that the most influential aquifer heterogeneity factors could change over time. With abundant presence of electron donors in the high permeable zones (initial stage), physical aquifer heterogeneity significantly influences the nitrate reduction since it enables the preferential transport of nitrate to these zones and enhances mixing of reactive partners. Chemical aquifer heterogeneity plays a comparatively minor role. Increasing the spatial variability of the hydraulic conductivity also increases the nitrate removal efficiency of the system. However, ignoring chemical aquifer heterogeneity can lead to an underestimation of nitrate removals in long-term behavior. With the increase of the spatial variability of the electron donor, i.e. chemical heterogeneity, the number of the "hot spots" i.e. zones with comparably higher reactivity, should also increase. Hence, nitrate removal efficiencies will also be spatially variable but overall removal efficiency will be sustained if longer time scales are considered and nitrate fronts reach these high reactivity zones.

  8. [Characterisation of excess sludge reduction in an anoxic + oxic-settling-anaerobic activated sludge process].

    PubMed

    Gao, Xu; Lu, Yan-Hua; Guo, Jin-Song

    2009-05-15

    An energy balance analysis method with auto calorimeter being adopted was introduced to determine calorific values of sludge samples in influent and effluent of uncoupling tank in an anoxic (A) + oxic-settling-anaerobic (OSA) process and a reference system. The affiliation of sludge amount change and its energy content were studied, as well as potential of excess sludge reduction was evaluated through modifying performance of uncoupling tank. The characteristi s and causes of sludge reduction in OSA system were deduced according to energy and matter balance analysis. Results show that when the hydraulic retention time (HRT) of uncoupling tank are 5.56 h, 7.14 h and 9 h, the excess sludge reduction of whole A + OS Asystem are 1.236 g/d, 0.771 g/d and 0.599 g/d respectively. Energy content of sludge flows into and out of the uncoupling tank changes, the specific calorific value of sludge in effluent is inclined to be higher than that in influent with the HRT of the tank increasing: there isn't any significant difference of sludge calorific values between influent and effluent at 5.56 h, while the differences are in 99-113 J/g at 7.14 h, and 191-329 J/g at 9 h. Sludge in uncoupling tank would decay and longer HRT will result in more attenuation. It could be concluded that excess sludge reduction of A + OSA system is caused by both of sludge decay in uncoupling tank and sludge proliferation in AO reaction zone.

  9. Influence of electrochemical reduction and oxidation processes on the decolourisation and degradation of C.I. Reactive Orange 4 solutions.

    PubMed

    del Río, A I; Molina, J; Bonastre, J; Cases, F

    2009-06-01

    The electrochemical treatment of wastewaters from textile industry is a promising treatment technique for substances which are resistant to biodegradation. This paper presents the results of the electrochemical decolourisation and degradation of C.I. Reactive Orange 4 synthetic solutions (commercially known as Procion Orange MX2R). Electrolyses were carried out under galvanostatic conditions in a divided or undivided electrolytic cell. Therefore, oxidation, reduction or oxido-reduction experiences were tested. Ti/SnO(2)-Sb-Pt and stainless steel electrodes were used as anode and cathode, respectively. Degradation of the dye was followed by TOC, total nitrogen, COD and BOD(5) analyses. TOC removal after an oxidation process was higher than after oxido-reduction while COD removal after this last process was about 90%. Besides, the biodegradability of final samples after oxido-reduction process was studied and an improvement was observed. UV-Visible spectra revealed the presence of aromatic structures in solution when an electro-reduction was carried out while oxido-reduction process degraded both azo group and aromatic structures. HPLC analyses indicated the presence of a main intermediate after the reduction process with a chemical structure closely similar to 2-amine-1, 5-naphthalenedisulfonic acid. The lowest decolourisation rate corresponded to electrochemical oxidation. In these experiences a higher number of intermediates were generated as HPLC analysis demonstrated. The decolourisation process for the three electrochemical processes studied presented a pseudo-first order kinetics.

  10. Effect of fruit and vegetable processing on reduction of synthetic pyrethroid residues.

    PubMed

    Chauhan, Reena; Kumari, Beena; Rana, M K

    2014-01-01

    In this review, we emphasize that the advantages associated with applying pesticides to enhance agricultural productivity must be weighed against the possible health hazards arising from the appearance of toxic pesticide residues in food. First and foremost, pesticides should be handled and applied in compliance with good agricultural practices to minimize environmental or food commodity contamination.In developing countries, good agricultural practices are not fully abided by.When vegetables are produced in such countries, pesticides are applied or prospectively applied at each growth stage of the crop. Hence, contamination of vegetables and other food commodities occur. It is well known that processing of food derived from pesticide treated crop commodities can serve to reduce residues that reach consumers. Food safety can therefore partially be enhanced by employing suitable food processing techniques and appropriate storage periods, even in developing countries. Even common and simple household processing techniques for certain foods acquire significance as means to reduce the intake of harmful pesticide food residues.Pesticide residue levels in post-harvest raw agricultural commodities (RAC) are affected by the storage, handling and the processing steps they pass through, while being prepared for human consumption. The review of cogent literature presented in this article demonstrated differences among the pyrethroid insecticide residues present on or in foods, depending on how the RAC from which they came were processed for consumption. Peeling vegetables or fruit reduced pyrethroid residues the most (60-100% ), and juicing was nearly as effective in reducing residues (70-100% ). The least reduction occurred for foodstuffs that were only washed with tap water (I 0-70% ). Washing RACs with saline water and detergent was more effective(34-60%) in reducing residues than was simple washing under tap water. Freezing is also effective in reducing residue levels and

  11. Facile synthesis of single-crystal silver nanowires through a tannin-reduction process

    NASA Astrophysics Data System (ADS)

    Tian, Xuelin; Li, Juan; Pan, Shilie

    2009-10-01

    A facile aqueous-phase approach for the synthesis of silver nanowires is reported, in which tannin (C76H52O46) is used as a mild reducing agent for silver nitrate. This synthesis is a root-temperature, seedless process, and does not need any surfactant or capping agent to direct the anisotropic growth of the nanoparticles. The obtained silver nanowires are about 25 nm in diameter and up to 20 μm in length. Unlike the usually reported cases of silver nanowires or nanorods, in which the silver nanocrystals were often generated with a multi-twinned structure, in our experiments the nanowires adopt a single-crystal structure with their growth direction along the [100] axis. Investigations on the influence of different experimental conditions indicate that slow rate of the reduction process is a key factor for inducing the anisotropic growth of the nanowires.

  12. Radiation dose reduction in digital radiography using wavelet-based image processing methods

    NASA Astrophysics Data System (ADS)

    Watanabe, Haruyuki; Tsai, Du-Yih; Lee, Yongbum; Matsuyama, Eri; Kojima, Katsuyuki

    2011-03-01

    In this paper, we investigate the effect of the use of wavelet transform for image processing on radiation dose reduction in computed radiography (CR), by measuring various physical characteristics of the wavelet-transformed images. Moreover, we propose a wavelet-based method for offering a possibility to reduce radiation dose while maintaining a clinically acceptable image quality. The proposed method integrates the advantages of a previously proposed technique, i.e., sigmoid-type transfer curve for wavelet coefficient weighting adjustment technique, as well as a wavelet soft-thresholding technique. The former can improve contrast and spatial resolution of CR images, the latter is able to improve the performance of image noise. In the investigation of physical characteristics, modulation transfer function, noise power spectrum, and contrast-to-noise ratio of CR images processed by the proposed method and other different methods were measured and compared. Furthermore, visual evaluation was performed using Scheffe's pair comparison method. Experimental results showed that the proposed method could improve overall image quality as compared to other methods. Our visual evaluation showed that an approximately 40% reduction in exposure dose might be achieved in hip joint radiography by using the proposed method.

  13. Oscillatory behavior of the surface reduction process of multilayer graphene oxide at room temperature

    NASA Astrophysics Data System (ADS)

    Voylov, Dmitry; Ivanov, Ilia; Bykov, Valerii; Tsybenova, Svetlana; Merkulov, Igor; Kurochkin, Sergei; Holt, Adam; Kisliuk, Alexandr

    The graphene oxide (GO) is one of 2D materials which continues to be studied intensively since it is thought can be used as a precursor of graphene. Recently, it was found that the chemical composition of multilayer GO is metastable on the time scale of one month even at room temperature. The observed changes in chemical composition were attributed to a reduction process controlled by the in-plane diffusion of functional groups which progresses through radical reactions. Here we report the observation of oscillatory oxidation-reduction (redox) reactions on the surface of multilayer GO films at room temperature. The redox reactions exhibited dampened oscillatory behavior with a period of about 5 days and found to be dependent on the time elapsed from GO deposition. The kinetic behavior of the processes and observed metastability of the surface functional groups are adequately described by two models involving reactions between functional groups of GO and reactant diffusion. US team acknowledges partial financial support from the Division of Materials Science and Engineering, U.S. Department of Energy, Office of Basic Energy Sciences.

  14. [Sulfate reduction and microbial processes of the methane cycle in the sediments of the Sevastopol bay].

    PubMed

    Pimenov, N V; Egorov, V N; Kanapatskiĭ, T A; Malakhova, T V; Artemov, Iu G; Sigalevich, P A; Malakhova, L V

    2013-01-01

    The rates of microbial processes of sulfate reduction and of the methane cycle were measured in the bottom sediments of the Sevastopol basin, where seeps of gaseous methane have been previously found. Typically for marine environments, sulfate reduction played the major role in the terminal phase of decomposition of organic matter (OM) in reduced sediments of this area. The rate of this process depended on the amount of available OM. The rate of methanogenesis in the sediments increased with depth, peaking in the subsurface horizons, where decreased sulfate concentration was detected in the pore water. The highest rates of sulfate-dependent anaerobic methane oxidation were found close to the methane-sulfate transition zone as is typical of most investigated marine sediments. The data on the carbon isotopic composition of gaseous methane from the seeps and dissolved CH4 from the bottom sediments, as well as on the rates of microbial methanogenesis and methane oxidation indicate that the activity of the methane seeps results from accumulation of biogenic methane in the cavities of the underlying geological structures with subsequent periodic release of methane bubbles into the water column.

  15. A Biophysicochemical Model for NO Removal by the Chemical Absorption-Biological Reduction Integrated Process.

    PubMed

    Zhao, Jingkai; Xia, Yinfeng; Li, Meifang; Li, Sujing; Li, Wei; Zhang, Shihan

    2016-08-16

    The chemical absorption-biological reduction (CABR) integrated process is regarded as a promising technology for NOx removal from flue gas. To advance the scale-up of the CABR process, a mathematic model based on mass transfer with reaction in the gas, liquid, and biofilm was developed to simulate and predict the NOx removal by the CABR system in a biotrickling filter. The developed model was validated by the experimental results and subsequently was used to predict the system performance under different operating conditions, such as NO and O2 concentration and gas and liquid flow rate. NO distribution in the gas phase along the biotrickling filter was also modeled and predicted. On the basis of the modeling results, the liquid flow rate and total iron concentration were optimized to achieve >90% NO removal efficiency. Furthermore, sensitivity analysis of the model revealed that the performance of the CABR process was controlled by the bioreduction activity of Fe(III)EDTA. This work will provide the guideline for the design and operation of the CABR process in the industrial application.

  16. Kinetics of the Reduction of Hematite Concentrate Particles by Carbon Monoxide Relevant to a Novel Flash Ironmaking Process

    NASA Astrophysics Data System (ADS)

    Chen, Feng; Mohassab, Yousef; Zhang, Shengqin; Sohn, Hong Yong

    2015-08-01

    A novel ironmaking process is under development at the University of Utah to produce iron directly from iron oxides concentrates by the gas-solid flash reaction using gaseous fuels and reductants. This process will reduce energy consumption and minimize carbon dioxide emissions. Having investigated the hydrogen reduction kinetics of magnetite and hematite concentrate particles relevant to the novel flash ironmaking process, the carbon monoxide reduction kinetics of hematite concentrate particles (average particle size 21 µm) was determined in the temperature range 1473 K to 1623 K (1200 °C to 1350 °C) under various carbon monoxide partial pressures. At 1623 K (1350 °C) and residence time 5 seconds, the reduction degree of hematite concentrate particles was more than 90 pct under a pure carbon monoxide. This is slower than reduction by hydrogen but still significant, indicating that CO will contribute to the reduction of hematite concentrate in the flash process. The kinetics of CO reduction separately from hydrogen is important for understanding and analyzing the complex kinetics of hematite reduction by the H2 + CO mixtures. The nucleation and growth rate equation with the Avrami parameter n = 1.0 adequately described the carbon monoxide reduction kinetics of hematite concentrate particles. The reduction rate is of 1st order with respect to the partial pressure of carbon monoxide and the activation energy of the reaction was 231 kJ/mol, indicating strong temperature dependence. The following complete rate equation was developed that can satisfactorily predict the carbon monoxide reduction kinetics of hematite concentrate particles and is suitable for the design of a flash reactor where X is the fraction of oxygen removed from iron oxide, R is 8.314 J/mol K, T is in K, p is in atm, and t is in seconds.

  17. Low-temperature NOx reduction processes using combined systems of pulsed corona discharge and catalysts

    NASA Astrophysics Data System (ADS)

    Kim, H. H.; Takashima, K.; Katsura, S.; Mizuno, A.

    2001-02-01

    In this paper, we will report NOx removal via reduction processes using two types of combined system of pulse corona discharge and catalysts: the single-stage plasma-driven catalyst (PDC) system, and the two-stage plasma-enhanced selective catalytic reduction (PE-SCR) system. Several catalysts, such as γ-alumina catalysts, mechanically mixed catalysts of γ-alumina with BaTiO3 or TiO2, and Co-ZSM-5 were tested. In the PDC system, which is directly activated by the discharge plasma, it was found that the use of additives was necessary to achieve NOx removal by reduction. Removal rates of NO and NOx were linearly increased as the molar ratio of additive to NOx increased. The dependence of NO and NOx removal on the gas hourly space velocity (GHSV) at a fixed specific input energy (SIE) indicates that plasma-induced surface reaction on the catalyst plays an important role in the PDC system. It was found that the optimal GHSV of the PDC system with the γ-alumina catalyst was smaller than 6000 h-1. Mechanical mixing of γ-alumina with BaTiO3 or TiO2 did not enhance NO and NOx removal and γ-alumina alone was found to be the most suitable catalyst. The dielectric constant of the catalyst only influenced the plasma intensity, not the NOx removal. In the PE-SCR system, plasma-treated NOx (mostly NO2) was reduced effectively with NH3 over the Co-ZSM-5 catalyst at a relatively low temperature of 150 °C. Under optimal conditions the energy cost and energy yield were 25 eV/molecule and 21 g-N (kWh)-1, respectively.

  18. Long-term treatment issues with chromite ore processing residue (COPR): Cr(6+) reduction and heave.

    PubMed

    Moon, Deok Hyun; Wazne, Mahmoud; Dermatas, Dimitris; Christodoulatos, Christos; Sanchez, Adriana M; Grubb, Dennis G; Chrysochoou, Maria; Kim, Min Gyu

    2007-05-17

    A pugmill treatability study was conducted to remediate chromite ore processing residue (COPR) using ferrous sulfate heptahydrate (FeSO(4) x 7H(2)O) as a reductant. Two different types of COPR, with respect to particle size and mineralogy, were tested in this study. Two different stoichiometric ratios of FeSO(4) x 7H(2)O to Cr(6+) (5x and 8x) were applied to reduce Cr(6+) to Cr(3+). The effectiveness of FeSO(4).7H(2)O treatment was assessed using the toxicity characteristic leaching procedure (TCLP) tests and X-ray absorption near edge structure (XANES) analyses. TCLP results obtained from the pugmill treatability study showed that TCLP Cr concentrations were less than the TCLP regulatory limit of 5mg/L upon 8x FeSO(4) x 7H(2)O treatment for up to 420 days but may fail to meet this regulatory limit in the long-term. XANES results obtained from samples cured for 300 days showed that all of the treated samples failed the New Jersey Department of Environmental Protection (NJDEP) clean up level for Cr(6+) of 240 mg/kg. However, the Cr(6+) concentration from the sample with the smaller particle size approached 240 mg/kg (338 mg/kg), suggesting that particle size reduction prior to the addition of reductant may improve the effectiveness of the treatment. COPR heaving was investigated with unconfined swell tests upon 5x and 8x FeSO(4) x 7H(2)O treatment. The formation of ettringite, an expansive material, was investigated following the swell tests using X-ray powder diffraction (XRPD). Significant heaving (>50 vol%) was observed at curing times of 138 days for the 5x treatment and the ettringite formation was identified by XRPD analyses.

  19. Determination of 5-log pathogen reduction times for heat-processed, acidified vegetable brines.

    PubMed

    Breidt, F; Hayes, J S; Osborne, J A; McFeeters, R F

    2005-02-01

    Recent outbreaks of acid-resistant food pathogens in acid foods, including apple cider and orange juice, have raised concerns about the safety of acidified vegetable products. We determined pasteurization times and temperatures needed to assure a 5-log reduction in the numbers of Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella strains in acidified cucumber pickle brines. Cocktails of five strains of each pathogen were (separately) used for heat-inactivation studies between 50 and 60 degrees C in brines that had an equilibrated pH value of 4.1. Salmonella strains were found to be less heat resistant than E. coli O157:H7 or L. monocytogenes strains. The nonlinear killing curves generated during these studies were modeled using a Weibull function. We found no significant difference in the heat-killing data for E. coli O157:H7 and L. monocytogenes (P = 0.9709). The predicted 5-log reduction times for E. coli O157:H7 and L. monocytogenes were found to fit an exponential decay function. These data were used to estimate minimum pasteurization times and temperatures needed to ensure safe processing of acidified pickle products and show that current industry pasteurization practices offer a significant margin of safety.

  20. Sequential reductive and oxidative biodegradation of chloroethenes stimulated in a coupled bioelectro-process.

    PubMed

    Lohner, Svenja T; Becker, Dirk; Mangold, Klaus-Michael; Tiehm, Andreas

    2011-08-01

    This article for the first time demonstrates successful application of electrochemical processes to stimulate sequential reductive/oxidative microbial degradation of perchloroethene (PCE) in mineral medium and in contaminated groundwater. In a flow-through column system, hydrogen generation at the cathode supported reductive dechlorination of PCE to cis-dichloroethene (cDCE), vinyl chloride (VC), and ethene (ETH). Electrolytically generated oxygen at the anode allowed subsequent oxidative degradation of the lower chlorinated metabolites. Aerobic cometabolic degradation of cDCE proved to be the bottleneck for complete metabolite elimination. Total removal of chloroethenes was demonstrated for a PCE load of approximately 1.5 μmol/d. In mineral medium, long-term operation with stainless steel electrodes was demonstrated for more than 300 days. In contaminated groundwater, corrosion of the stainless steel anode occurred, whereas DSA (dimensionally stable anodes) proved to be stable. Precipitation of calcareous deposits was observed at the cathode, resulting in a higher voltage demand and reduced dechlorination activity. With DSA and groundwater from a contaminated site, complete degradation of chloroethenes in groundwater was obtained for two months thus demonstrating the feasibility of the sequential bioelectro-approach for field application.

  1. Defining Constellation Suit Helmet Field of View Requirements Employing a Mission Segment Based Reduction Process

    NASA Technical Reports Server (NTRS)

    McFarland, Shane

    2009-01-01

    Field of view has always been a design feature paramount to helmets, and in particular space suits, where the helmet must provide an adequate field of view for a large range of activities, environments, and body positions. For Project Constellation, a different approach to helmet requirement maturation was utilized; one that was less a direct function of body position and suit pressure and more a function of the mission segment in which the field of view will be required. Through taxonimization of various parameters that affect suited field of view, as well as consideration for possible nominal and contingency operations during that mission segment, a reduction process was employed to condense the large number of possible outcomes to only six unique field of view angle requirements that still captured all necessary variables while sacrificing minimal fidelity.

  2. High-temperature corrosion observed in austenitic coils and tubes in a direct reduction process

    SciTech Connect

    Campillo, B.; Gonzalez, C.; Hernandez-Duque, G.; Juarez-Islas, J.A.

    2000-02-01

    The subject of this study is related to the performance of austenitic steel coils and tubes, in a range of temperatures between 425 and 870 C for the transport of reducing gas, in an installation involving the direct reduction of iron-ore by reforming natural gas. Evidence is presented that metal dusting is not the only unique high-temperature corrosion mechanism that caused catastrophic failures of austenitic 304 (UNS S30400) coils and HK-40 (UNS J94204) tubes. Sensitization as well as stress corrosion cracking occurred in 304 stainless steel coils and metal dusting took place in HK-40 tubes, a high resistance alloy. The role of continuous injection of H{sub 2}S into the process is suggested to avoid the high resistance metal dusting corrosion mechanism found in this kind of installation.

  3. An Interactive Procedure to Preserve the Desired Edges during the Image Processing of Noise Reduction

    NASA Astrophysics Data System (ADS)

    Hsu, Chih-Yu; Huang, Hsuan-Yu; Lee, Lin-Tsang

    2010-12-01

    The paper propose a new procedure including four stages in order to preserve the desired edges during the image processing of noise reduction. A denoised image can be obtained from a noisy image at the first stage of the procedure. At the second stage, an edge map can be obtained by the Canny edge detector to find the edges of the object contours. Manual modification of an edge map at the third stage is optional to capture all the desired edges of the object contours. At the final stage, a new method called Edge Preserved Inhomogeneous Diffusion Equation (EPIDE) is used to smooth the noisy images or the previously denoised image at the first stage for achieving the edge preservation. The Optical Character Recognition (OCR) results in the experiments show that the proposed procedure has the best recognition result because of the capability of edge preservation.

  4. A hybrid ED/RO process for TDS reduction of produced waters

    SciTech Connect

    Tsai, S.P.; Datta, R.; Frank, J.R.

    1995-12-31

    Large volumes of produced waters are generated from natural gas production. In the United States the prevailing management practice for produced waters is deep well injection, but this practice is costly. Therefore minimizing the need for deep well injection is desirable. A major treatment issue for produced waters is the reduction of total dissolved solids (TDS), which consist mostly of inorganic salts. A hybrid electrodialysis/reverse-osmosis (ED/RO) treatment process is being developed to concentrate the salts in produced waters and thereby reduce the volume of brine that needs to be managed for disposal. The desalted water can be used beneficially or discharged. In this study, laboratory feasibility experiments were conducted by using produced waters from multiple sites. A novel-membrane configuration approach to prevent fouling and scale formation was developed and demonstrated. Results of laboratory experiments and plans for field demonstration are discussed.

  5. The Effect of Mechanical Milling and Temperature to the Carbothermal Reduction Process of Silica Sand

    SciTech Connect

    Ghapur, E. A.; Mustapha, M.; Ismail, F.; Sidek, I.; Meh, B.

    2008-05-20

    This paper presents the investigation carried out to study the formation of silicon nitride and silicon carbide compound from the reaction of silica sand powders with carbon in nitrogen with 5% hydrogen atmosphere at temperatures between 1350 deg. C to 1550 deg. C. The effect of mechanical milled silica sand and different temperature during carbothermal reduction process was determined. The morphology of the synthesis products was characterized using scanning electron microscopy and its composition was determined by elemental and X-ray phase analysis. The formation of silicon nitride compound was facilitated by using silica sand with distorted structure by mechanical milling method. Further increased on temperature will lead to the formation of silicon carbide compound.

  6. Electron spin resonance studies on reduction process of nitroxyl spin radicals used in molecular imaging

    SciTech Connect

    Dhas, M. Kumara; Benial, A. Milton Franklin; Jawahar, A.

    2014-04-24

    The Electron spin resonance studies on the reduction process of nitroxyl spin probes were carried out for 1mM {sup 14}N labeled nitroxyl radicals in pure water and 1 mM concentration of ascorbic acid as a function of time. The electron spin resonance parameters such as signal intensity ratio, line width, g-value, hyperfine coupling constant and rotational correlation time were determined. The half life time was estimated for 1mM {sup 14}N labeled nitroxyl radicals in 1 mM concentration of ascorbic acid. The ESR study reveals that the TEMPONE has narrowest line width and fast tumbling motion compared with TEMPO and TEMPOL. From the results, TEMPONE has long half life time and high stability compared with TEMPO and TEMPOL radical. Therefore, this study reveals that the TEMPONE radical can act as a good redox sensitive spin probe for molecular imaging.

  7. Speckle reduction process based on digital filtering and wavelet compounding in optical coherence tomography for dermatology

    NASA Astrophysics Data System (ADS)

    Gómez Valverde, Juan J.; Ortuño, Juan E.; Guerra, Pedro; Hermann, Boris; Zabihian, Behrooz; Rubio-Guivernau, José L.; Santos, Andrés.; Drexler, Wolfgang; Ledesma-Carbayo, Maria J.

    2015-07-01

    Optical Coherence Tomography (OCT) has shown a great potential as a complementary imaging tool in the diagnosis of skin diseases. Speckle noise is the most prominent artifact present in OCT images and could limit the interpretation and detection capabilities. In this work we propose a new speckle reduction process and compare it with various denoising filters with high edge-preserving potential, using several sets of dermatological OCT B-scans. To validate the performance we used a custom-designed spectral domain OCT and two different data set groups. The first group consisted in five datasets of a single B-scan captured N times (with N<20), the second were five 3D volumes of 25 Bscans. As quality metrics we used signal to noise (SNR), contrast to noise (CNR) and equivalent number of looks (ENL) ratios. Our results show that a process based on a combination of a 2D enhanced sigma digital filter and a wavelet compounding method achieves the best results in terms of the improvement of the quality metrics. In the first group of individual B-scans we achieved improvements in SNR, CNR and ENL of 16.87 dB, 2.19 and 328 respectively; for the 3D volume datasets the improvements were 15.65 dB, 3.44 and 1148. Our results suggest that the proposed enhancement process may significantly reduce speckle, increasing SNR, CNR and ENL and reducing the number of extra acquisitions of the same frame.

  8. Effect of home processing on the distribution and reduction of pesticide residues in apples.

    PubMed

    Kong, Z; Shan, W; Dong, F; Liu, X; Xu, J; Li, M; Zheng, Y

    2012-08-01

    The effect of home processing (washing, peeling, coring and juicing) on residue levels of chlorpyrifos, β-cypermethrin, tebuconazole, acetamiprid and carbendazim in apple segments was investigated. The pesticide residues were determined by UPLC-MS/MS and GC with a flame photometric (FPD) and electron capture detection (ECD). The results indicated that the pesticide residue levels in the apple peel and core were higher compared with in the apple flesh. After peeled and cored apple was processed into apple juice and pomace, chlorpyrifos, β-cypermethrin and tebuconazole were concentrated in the apple pomace. However, residues of acetamiprid and carbendazim were exceptions. The apple pomace was free of acetamiprid, which was mainly present in the apple juice. After washing the mean loss of chlorpyrifos, β-cypermethrin, tebuconazole, acetamiprid and carbendazim from apples under recommended dosage and twofold higher dosage were 17-21%, 6.7-7.1%, 13-32%, 42-67% and 47-50%, respectively. The pesticide residues were significantly reduced in the edible part of the apple except for β-cypermethrin during peeling and coring process. The removal effect of apple juicing was found to be the most pronounced on β-cypermethrin residue, which was reduced in the range of 81-84%, and the reductions of chlorpyrifos, tebuconazole, acetamiprid and carbendazim upon apple juicing were in the range of 15-36%.

  9. Sulfonamide antibiotic reduction in aquatic environment by application of fenton oxidation process

    PubMed Central

    2013-01-01

    Presence of antibiotics in the environment may cause potential risk for aquatic environment and organisms. In this research, Fenton oxidation process was offered as an effective method for removal of antibiotic sulfamethoxazole from aqueous solutions. The experiments were performed on laboratory-scale study under complete mixing at 25±2°C. The effects of initial antibiotic concentration, molar ratio of H2O2/Fe+2, solution pH, concentration of H2O2, Fe+2 and reaction time was studied on the oxidation of sulfamethoxazole in three level. The results indicated that the optimal parameters for Fenton process were as follows: molar ratio of [H2O2]/[Fe+2] = 1.5, pH= 4.5, and contact time= 15 min. In this situation, the antibiotic removal and COD reduction were achieved 99.99% and 64.7-70.67%, respectively. Although, Fenton reaction could effectively degrade antibiotic sulfamethoxazole under optimum experimental conditions, however, the rate of mineralization was not completed. This process can be considered to eliminate other refractory antibiotics with similar structure or to increase their biodegradability. PMID:23570238

  10. Photomask defect tracing, analysis, and reduction with chemically amplified resist process

    NASA Astrophysics Data System (ADS)

    Lin, Cheng-ming; Lai, Rick; Huang, W. H.; Wang, B. C.; Chen, C. Y.; Kung, C. H.; Yoo, Chue-San; Chen, Jieh-Jang; Lee, Sheng-Cha

    2003-08-01

    The features of optical proximity correction are becoming very aggressive as production technology migrates into 90nm/130 nm regime. The complicated optical proximity correction (OPC) patterns often result in un-repairable defects, a major yield loss mechanisms in a mask production line. Defect control is increasingly important. A methodology for identifying defect sources and reduction is demonstrated in this paper. The mechanisms and causes of defect formation could be determined with corresponding process step on the strength of sequence inspections. The cause of half-etched opaque defect on negative CAR process was found from PR fragment contamination of e-beam exposure step. After clean-up of e-beam chamber, yield was increased over 20%. Big pinhole defect and contact of AttPSM positive process was found on ADI step. The possible cause was poor CAR adhesion. These two type defects were decreased by modification of developing recipe, special on rinse step. Design experiment with Taguchi method was used to optimize the interactive recipe of plasma descum and rinse step on developing step of implanted layer. Average defect density was decreased from 0.99 to 0.27, and percentage of zero defect rate has been increased from 29.5 to 63.3%.

  11. Streamlining an IRAF data reduction process Pythonically with Astropy and NDMapper

    NASA Astrophysics Data System (ADS)

    Turner, James

    2016-03-01

    In the course of re-writing my typical top-level GMOS-IFU data reduction sequence in Python for a research project, I have developed a small module that helps express the scientific process in a relatively intuitive way as a Pythonic series of operations on NDData collections, mapped to files, with existing IRAF steps integrated almost seamlessly (pending their eventual replacement). For scientific end-user purposes, this experiment aims to obviate a need for pipeline machinery, favouring simple control flow in the main script and retaining a smooth transition from high-level process description to lower-level libraries by encapsulating necessary bookeeping within the data representation and simple wrappers. The I/O abstraction should make support for file formats other than FITS (eg. ASDF) straightforward to add. This work-in-progress can be found at https://github.com/jehturner/ndmapper and I intend to split its functionality involving IRAF or instrument processing into a separate "ndprocess" module as the prototype nears completion, leaving a core "ndmapper" package, without any special dependencies, as a general add-on for nddata.

  12. Potential of front-face fluorescence to monitor OM reduction in drinking water during potabilization process

    NASA Astrophysics Data System (ADS)

    Lacotte, Pierre

    2014-05-01

    Elimination of OM in drinking water represents a great challenge for municipalities and technical actors to ensure that it can be safely used for consumption purposes. Indeed, current indicators such as Total Organic Carbon (TOC), turbidity or UV-Absorbance at 254 nm (UVA254) enable only non-specific overview of the amount of organic residuals in water. Fluorescence EEMs are a potent tool for discrimination and deep analysis of OM detailed composition and behaviour. It has been shown that several forms of OM co-exist in raw water, and come from various origins (bacteria, humic compounds…). Potabilization operation is composed of different steps that aim at decreasing all forms of OM using chemical as well as physical methods (ozone oxidation, filtration on activated carbon or sand, flocculation etc.). Unfortunately, it has been observed that reduction of OM during this process was not identical for all the forms, and the process showed a particular lack of efficiency during raining periods. 130 samples of water at various stages of potabilization were analyzed using home-made compact fluorometer, an apparatus composed of UV excitation LEDs. Using chemometrical treatment of spectral data, we put into highlight 5 different forms of OM that were identified according to litterature data. We evidenced the critical steps of the purification on OM reduction, as well as the relative content of each form from raw to product water. In particular, we showed that two forms were less reduced than the other three, so that progressive enrichment of total OM in the former was observed throughout the process. Moreover, a study was carried out in order to establish calibration models over conventional analyses using the spectral information. Highly satisfying models were thus obtained over TOC, turbidity and UVA254, with average RMSEC values of 13%, 7% and 16% respectively. These results demonstrate the potential of the fluorescence analyzer to simultaneously predict three major

  13. Array Processing for Radar Clutter Reduction and Imaging of Ice-Bed Interface

    NASA Astrophysics Data System (ADS)

    Gogineni, P.; Leuschen, C.; Li, J.; Hoch, A.; Rodriguez-Morales, F.; Ledford, J.; Jezek, K.

    2007-12-01

    A major challenge in sounding of fast-flowing glaciers in Greenland and Antarctica is surface clutter, which masks weak returns from the ice-bed interface. The surface clutter is also a major problem in sounding and imaging sub-surface interfaces on Mars and other planets. We successfully applied array-processing techniques to reduce clutter and image ice-bed interfaces of polar ice sheets. These techniques and tools have potential applications to planetary observations. We developed a radar with array-processing capability to measure thickness of fast-flowing outlet glaciers and image the ice-bed interface. The radar operates over the frequency range from 140 to 160 MHz with about an 800- Watt peak transmit power with transmit and receive antenna arrays. The radar is designed such that pulse width and duration are programmable. The transmit-antenna array is fed with a beamshaping network to obtain low sidelobes. We designed the receiver such that it can process and digitize signals for each element of an eight- channel array. We collected data over several fast-flowing glaciers using a five-element antenna array, limited by available hardpoints to mount antennas, on a Twin Otter aircraft during the 2006 field season and a four-element array on a NASA P-3 aircraft during the 2007 field season. We used both adaptive and non-adaptive signal-processing algorithms to reduce clutter. We collected data over the Jacobshavn Isbrae and other fast-flowing outlet glaciers, and successfully measured the ice thickness and imaged the ice-bed interface. In this paper, we will provide a brief description of the radar, discuss clutter-reduction algorithms, present sample results, and discuss the application of these techniques to planetary observations.

  14. Research and Industrial Application of a Process for Direct Reduction of Molten High-Lead Smelting Slag

    NASA Astrophysics Data System (ADS)

    Li, Weifeng; Zhan, Jing; Fan, Yanqing; Wei, Chang; Zhang, Chuanfu; Hwang, Jiann-Yang

    2017-01-01

    A pyrometallurgical process for the direct reduction of molten high-lead smelting slag obtained by the Shuikoushan (SKS) method was reported in this article using solid anthracite as the fuel and reductant. The chemical composition, the lead phase composition, and the physical properties of the molten high-lead slag were examined. The effects of the process parameters on the recovery rate of valued metals were investigated in the laboratory. According to the experimental results, a new efficient bottom blow reduction furnace was employed in the pilot-scale test for high-lead slag reduction. The results showed the average recovery rate of lead was more than 96.0% with lower Pb and high Zn content of the reducing slag under the condition of reduction temperature 1100-1200°C, coal ratio 5.5-7.5%, reduction time 90-150 min, CaO/SiO2 ratio 0.35-0.45, and FeO/SiO2 ratio 1.4-1.55. Moreover, nearly 250 kg of standard coal per ton of crude Pb output was reduced compared with the blast furnace reduction process.

  15. ANION ANALYSES BY ION CHROMATOGRAPHY FOR THE ALTERNATE REDUCTANT DEMONSTRATION FOR THE DEFENSE WASTE PROCESSING FACILITY

    SciTech Connect

    Best, D.

    2010-08-04

    The Process Science Analytical Laboratory (PSAL) at the Savannah River National Laboratory was requested by the Defense Waste Processing Facility (DWPF) to develop and demonstrate an Ion Chromatography (IC) method for the analysis of glycolate, in addition to eight other anions (fluoride, formate, chloride, nitrite, nitrate, sulfate, oxalate and phosphate) in Sludge Receipt and Adjustment Tank (SRAT) and Slurry Mix Evaporator (SME) samples. The method will be used to analyze anions for samples generated from the Alternate Reductant Demonstrations to be performed for the DWPF at the Aiken County Technology Laboratory (ACTL). The method is specific to the characterization of anions in the simulant flowsheet work. Additional work will be needed for the analyses of anions in radiological samples by Analytical Development (AD) and DWPF. The documentation of the development and demonstration of the method fulfills the third requirement in the TTQAP, SRNL-RP-2010-00105, 'Task Technical and Quality Assurance Plan for Glycolic-Formic Acid Flowsheet Development, Definition and Demonstrations Tasks 1-3'.

  16. In Situ Reduction of Hexavalent Chromium in Alkaline Soils Enriched with Chromite Ore Processing Residue.

    PubMed

    Higgins, Thomas E; Halloran, Amy R; Dobbins, Maribeth E; Pittignano, Alex J

    1998-11-01

    In investigating chromium sites in New Jersey, it has been observed that an organic-rich 0.5- to 4-foot-thick layer of decayed vegetation (locally known as "meadowmat") underlying the chromium-containing material acts as a natural barrier to the migration of Cr(VI). The groundwater in a sand layer directly beneath the meadowmat has been shown to contain low or nondetectable levels of chromium. The meadowmat is under highly reduced conditions due to bacterial activity associated with the organic material. Based on the observed ability of the meadowmat to reduce Cr(VI) to Cr(III), the feasibility of in situ reduction of Cr(VI) to Cr(III) at chromite ore processing residue (COPR) sites was investigated in biologically-active, laboratory-scale test columns. COPR typically has a high pH (in excess of 12) and may contain total chromium concentrations as high as 70,000 mg/kg. Experimental results demonstrated that the addition of a mineral acid (to lower the pH to between 7.0 and 9.5) and a bacteria-rich organic substrate (fresh manure) resulted in the reduction of Cr(VI) to the less toxic and less mobile trivalent form. Pore water Cr(VI) was reduced from approximately 800 mg/L to less than 0.05 mg/L over a period of eight months. This is less than the U.S. Environmental Protection Agency's (EPA) Maximum Contaminant Level (MCL) for chromium in drinking water of 0.1 mg/L. Solid phase Cr(VI) concentrations decreased from approximately 2,000 mg/kg to less than 10 mg/kg in the columns over a period of 11 months while the total chromium concentrations remained unchanged. Toxicity Characteristic Leaching Procedure (TCLP) extract from the treated columns met the regulatory limit of 5 mg/L of Cr, whereas the untreated samples had TCLP extract concentrations greater than 40 mg/L. This study demonstrated the potential applicability of in situ reduction to soils contaminated with Cr(VI) by adjusting the pH to between 7.0 and 9.5 and mixing in a bacteria-rich organic substrate.

  17. In situ reduction of hexavalent chromium in alkaline soils enriched with chromite ore processing residue

    PubMed

    Higgins; Halloran; Dobbins; Pittignano

    1998-11-01

    In investigating chromium sites in New Jersey, it has been observed that an organic-rich 0.5- to 4-foot-thick layer of decayed vegetation (locally known as "meadowmat") underlying the chromium-containing material acts as a natural barrier to the migration of Cr(VI). The groundwater in a sand layer directly beneath the meadowmat has been shown to contain low or nondetectable levels of chromium. The meadowmat is under highly reduced conditions due to bacterial activity associated with the organic material. Based on the observed ability of the meadowmat to reduce Cr(VI) to Cr(III), the feasibility of in situ reduction of Cr(VI) to Cr(III) at chromite ore processing residue (COPR) sites was investigated in biologically-active, laboratory-scale test columns. COPR typically has a high pH (in excess of 12) and may contain total chromium concentrations as high as 70,000 mg/kg. Experimental results demonstrated that the addition of a mineral acid (to lower the pH to between 7.0 and 9.5) and a bacteria-rich organic substrate (fresh manure) resulted in the reduction of Cr(VI) to the less toxic and less mobile trivalent form. Pore water Cr(VI) was reduced from approximately 800 mg/L to less than 0.05 mg/L over a period of eight months. This is less than the U.S. Environmental Protection Agency's (EPA) Maximum Contaminant Level (MCL) for chromium in drinking water of 0.1 mg/L. Solid phase Cr(VI) concentrations decreased from approximately 2,000 mg/kg to less than 10 mg/kg in the columns over a period of 11 months while the total chromium concentrations remained unchanged. Toxicity Characteristic Leaching Procedure (TCLP) extract from the treated columns met the regulatory limit of 5 mg/L of Cr, whereas the untreated samples had TCLP extract concentrations greater than 40 mg/L. This study demonstrated the potential applicability of in situ reduction to soils contaminated with Cr(VI) by adjusting the pH to between 7.0 and 9.5 and mixing in a bacteria-rich organic substrate.

  18. Reduction of Interhemispheric Functional Connectivity in Sensorimotor and Visual Information Processing Pathways in Schizophrenia

    PubMed Central

    Lang, Xu; Wang, Le; Zhuo, Chuan-Jun; Jia, Feng; Wang, Li-Na; Wang, Chun-Li

    2016-01-01

    Background: Previous studies have demonstrated interhemispheric functional connectivity alterations in schizophrenia. However, the relationship between these alterations and the disease state of schizophrenia is largely unknown. Therefore, we aimed to investigate this relationship using voxel-mirrored homotopic connectivity (VMHC) method. Methods: This study enrolled 36 schizophrenia patients with complete remission, 58 schizophrenia patients with incomplete remission and 55 healthy controls. The VMHC was calculated based on resting-state functional magnetic resonance imaging data. Differences in VMHC among three groups were compared using one-way analysis of variance. A brain region with a significant difference in VMHC was defined as a region of interest (ROI), and the mean VMHC value in the ROI was extracted for the post hoc analysis, i.e., pair-wise comparisons across the three groups. Results: VMHC in the visual region (inferior occipital and fusiform gyri) and the sensorimotor region (paracentral lobule) showed significant differences among the three groups (P < 0.05, a false discovery rate method corrected). Pair-wise comparisons in the post hoc analysis showed that VMHC of the visual and sensorimotor regions in schizophrenia patients with complete remission and incomplete remission was lower than that in healthy controls (P < 0.05, Bonferroni corrected); however, there was no significant difference between the two patient subgroups. Conclusions: Interhemispheric functional connectivity in the sensorimotor and visual processing pathways was reduced in patients with schizophrenia, but this reduction was unrelated to the disease state; thus, this reduction may serve as a trait marker of schizophrenia. PMID:27748333

  19. Defining Constellation Suit Helmet Field of View Requirements Employing a Mission Segment Based Reduction Process

    NASA Technical Reports Server (NTRS)

    McFarland, Shane M.

    2008-01-01

    Field of view has always been a design feature paramount to helmet design, and in particular space suit design, where the helmet must provide an adequate field of view for a large range of activities, environments, and body positions. For Project Constellation, a slightly different approach to helmet requirement maturation was utilized; one that was less a direct function of body position and suit pressure and more a function of the mission segment in which the field of view is required. Through taxonimization of various parameters that affect suited FOV, as well as consideration for possible nominal and contingency operations during that mission segment, a reduction process was able to condense the large number of possible outcomes to only six unique field of view angle requirements that still captured all necessary variables without sacrificing fidelity. The specific field of view angles were defined by considering mission segment activities, historical performance of other suits, comparison between similar requirements (pressure visor up versus down, etc.), estimated requirements from other teams for field of view (Orion, Altair, EVA), previous field of view tests, medical data for shirtsleeve field of view performance, and mapping of visual field data to generate 45degree off-axis field of view requirements. Full resolution of several specific field of view angle requirements warranted further work, which consisted of low and medium fidelity field of view testing in the rear entry ISuit and DO27 helmet prototype. This paper serves to document this reduction progress and followup testing employed to write the Constellation requirements for helmet field of view.

  20. High-performance Bi-stage process in reduction of graphene oxide for transparent conductive electrodes

    NASA Astrophysics Data System (ADS)

    Alahbakhshi, Masoud; Fallahi, Afsoon; Mohajerani, Ezeddin; Fathollahi, Mohammad-Reza; Taromi, Faramarz Afshar; Shahinpoor, Mohsen

    2017-02-01

    A novel and innovative approach to develop reduction of graphene oxide (GO) solution for fabrication of highly and truly transparent conductive electrode (TCE) has been presented. Thanks to outstanding mechanical and electronic properties of graphene which offer practical applications in synthesizing composites as well as fabricating various optoelectronic devices, in this study, conductive reduced graphene oxide (r-GO) thin films were prepared through sequential chemical and thermal reduction process of homogeneously dispersed GO solutions. The conductivity and transparency of r-GO thin film is regulated using hydroiodic acid (HI) as reducing agent following by vacuum thermal annealing. The prepared r-GO is characterized by XRD, AFM, UV-vis and Raman spectroscopy. the AFM topographic images reveal surface roughness almost ∼11 nm which became less than 2 nm for the 4 mg/mL solution. Moreover, XRD analysis and Raman spectra substantiate the interlayer spacing between rGO layers has been reduced dramatically and also electronic conjugation has been ameliorated after using HI chemical agent and 700 °C thermal annealing sequentially. Subsequently providing r-GO transparent electrode with decent and satisfactory transparency, acceptable conductivity and suitable work function, it has been exploited as the anode in organic light emitting diode (OLED). The maximum luminance efficiency and maximum power efficiency reached 4.2 cd/A and 0.83 lm/W, respectively. We believe that by optimizing the hole density, sheet resistance, transparency and surface morphology of the r-GO anodes, the device efficiencies can be remarkably increased further.

  1. Investigation of Mercury Reduction in Gold Stripping Process at Elevated Temperature

    NASA Astrophysics Data System (ADS)

    Pramudya, Irawan

    Mercury is present in many gold ores. By processing these ores, there is a potential of emitting mercury to the environment. Carbon regeneration kiln stacks have been observed as one of the primary source of mercury emission into the atmosphere. Before it is recycled back into the carbon in leach (CIL) or carbon in columns (CIC), carbon used in the gold extraction process needs to be reactivated thermally. Emission of mercury can be minimized by keeping the mercury left in the carbon low before it goes to the carbon regeneration kiln stacks. The objective of this study is establishing the optimum elution conditions of mercury cyanide from loaded carbon (which includes the eluent, concentration, temperature and elution time) with respect to gold stripping. Several methods such as acid washing (UNR-100, HCl or ethanol/UNR-100) were investigated prior to the stripping process. Furthermore, conventional pressurized Zadra and modified Zadra were also studied with regards to mercury concentration in the solution and vapor state as well as maximizing the gold stripping from industrial loaded carbon. 7% UNR-100 acid washing of loaded carbon at 80°C was able to wash out approximately 90% of mercury while maintaining the gold adsorption on the carbon (selective washing). The addition of alcohol in the UNR-100 acid washing solution was able to enhance mercury washing from 90% to 97%. Furthermore, mercury stripping using conventional pressurized (cyanide-alkaline) Zadra was best performed at 80°C (minimal amount of mercury reduced and volatilized) whereas using the same process only 40% of gold was stripped, which makes this process not viable. When alcohol was added to the stripping solution, at 80°C, 95% of gold was detected in the solution while keeping the reduction and volatilization of mercury low. The outcome of this study provides a better understanding of mercury behavior during the acid washing and stripping processes so that the risk of mercury exposure and

  2. Hexavalent chromium reduction in solution and in chromite ore processing residue-enriched soil by tartaric Acid with isopropyl alcohol and divalent manganese as co-reductants.

    PubMed

    Brose, Dominic A; James, Bruce R

    2013-01-01

    Chromite ore processing residue (COPR), the solid waste product from the high-temperature alkaline processing of ferrochromite (FeO·CrO), contains Cr(VI) in soluble and insoluble compounds formed in the roasting process. This research investigated tartaric acid in combination with Mn and isopropyl alcohol (IPOH ) as co-reductants for reagent- and COPR-derived Cr(VI). The reduction of Cr(VI) by tartaric acid alone at pH 5.0 or greater was negligible; however, in the presence of Mn or IPOH, reduction occurred in hours. Isopropyl alcohol enhanced Cr(VI) reduction, probably via formation of a termolecular complex with the alcohol, tartaric acid, and Cr(VI). In aqueous solutions of reagent-derived Cr(VI) at pH 4, 12 mmol L tartaric acid with 1.0 mmol L Mn or 1.0 mmol L Mn and 0.29 mol L (2% v/v) IPOH reduced 1.0 mmol L Cr(VI) in 48 h. The same treatments at pH 5.5 reduced 0.60 and 0.58 mmol L Cr(VI) (60%) in 96 h, respectively. A minimum half-life of 10.2 h was calculated from first-order rate constants obtained from Mn and IPOH-Mn co-reductant treatments with tartaric acid at pH 4. The most COPR-derived Cr(VI) reduced in suspension was by IPOH and Mn at high acidity (pH 5.8), which reduced 0.52 mmol L (52%) of the COPR-derived soluble Cr(VI) at 96 h. The enhanced reduction of soluble Cr(VI) by tartaric acid by the addition of Mn proceeds within a complex formed by an esterification reaction between tartaric acid and Cr(VI) with Mn bound to tartaric acid. The combined treatment of tartaric acid, IPOH, Mn, and a strong acid to lower the pH of COPR-enriched soils would be effective in field applications of this chemistry. By creating a slurry of the field soil with these amendments, mass transfer limitations would be overcome, and Cr(VI) would be reduced to Cr(III) in days.

  3. EPIC: A C++ Service Oriented Inter-process Messaging Framework and its Usage in the PFS Reduction Pipeline

    NASA Astrophysics Data System (ADS)

    Vidal, C.; Chabaud, P.-Y.

    2015-09-01

    We present EPIC: a C++ library for managing inter process communication in the Prime Focus Spectrograph Data Reduction Pipeline (PFS/DRP). The aim of EPIC is to provide a consistent framework for building distributed softwares that can be efficiently used in various kind of astronomical data processing pipeline. The Prime Focus Spectrograph multi-fiber system will allow more than 2000 simultaneous spectral observations of astronomical targets at the same time, leading the need of a high throughput system for processing data reduction of each observations. This framework provide a load balanced, messages and services oriented system, where nodes communicate with each other using a set of C++ APIs.

  4. The Validation of Vapor Phase Hydrogen Peroxide Microbial Reduction for Planetary Protection and a Proposed Vacuum Process Specification

    NASA Technical Reports Server (NTRS)

    Chung, Shirley; Barengoltz, Jack; Kern, Roger; Koukol, Robert; Cash, Howard

    2006-01-01

    The Jet Propulsion Laboratory, in conjunction with the NASA Planetary Protection Officer, has selected the vapor phase hydrogen peroxide sterilization process for continued development as a NASA approved sterilization technique for spacecraft subsystems and systems. The goal is to include this technique, with an appropriate specification, in NPR 8020.12C as a low temperature complementary technique to the dry heat sterilization process.To meet microbial reduction requirements for all Mars in-situ life detection and sample return missions, various planetary spacecraft subsystems will have to be exposed to a qualified sterilization process. This process could be the elevated temperature dry heat sterilization process (115 C for 40 hours) which was used to sterilize the Viking lander spacecraft. However, with utilization of such elements as highly sophisticated electronics and sensors in modern spacecraft, this process presents significant materials challenges and is thus an undesirable bioburden reduction method to design engineers. The objective of this work is to introduce vapor hydrogen peroxide (VHP) as an alternative to dry heat microbial reduction to meet planetary protection requirements.The VHP process is widely used by the medical industry to sterilize surgical instruments and biomedical devices, but high doses of VHP may degrade the performance of flight hardware, or compromise material properties. Our goal for this study was to determine the minimum VHP process conditions to achieve microbial reduction levels acceptable for planetary protection.

  5. Mercury Reduction and Removal from High Level Waste at the Defense Waste Processing Facility - 12511

    SciTech Connect

    Behrouzi, Aria; Zamecnik, Jack

    2012-07-01

    The Defense Waste Processing Facility processes legacy nuclear waste generated at the Savannah River Site during production of enriched uranium and plutonium required by the Cold War. The nuclear waste is first treated via a complex sequence of controlled chemical reactions and then vitrified into a borosilicate glass form and poured into stainless steel canisters. Converting the nuclear waste into borosilicate glass is a safe, effective way to reduce the volume of the waste and stabilize the radionuclides. One of the constituents in the nuclear waste is mercury, which is present because it served as a catalyst in the dissolution of uranium-aluminum alloy fuel rods. At high temperatures mercury is corrosive to off-gas equipment, this poses a major challenge to the overall vitrification process in separating mercury from the waste stream prior to feeding the high temperature melter. Mercury is currently removed during the chemical process via formic acid reduction followed by steam stripping, which allows elemental mercury to be evaporated with the water vapor generated during boiling. The vapors are then condensed and sent to a hold tank where mercury coalesces and is recovered in the tank's sump via gravity settling. Next, mercury is transferred from the tank sump to a purification cell where it is washed with water and nitric acid and removed from the facility. Throughout the chemical processing cell, compounds of mercury exist in the sludge, condensate, and off-gas; all of which present unique challenges. Mercury removal from sludge waste being fed to the DWPF melter is required to avoid exhausting it to the environment or any negative impacts to the Melter Off-Gas system. The mercury concentration must be reduced to a level of 0.8 wt% or less before being introduced to the melter. Even though this is being successfully accomplished, the material balances accounting for incoming and collected mercury are not equal. In addition, mercury has not been effectively

  6. Role of DDL processes during electrolytic reduction of Cu(II) in a low oxygen environment.

    PubMed

    Brosky, Rebekah T; Pamukcu, Sibel

    2013-11-15

    Heavy metals typically accumulate in reduced bottom sediments after being discharged into waterways by industrial and municipal processes. A laboratory experiment was conducted in order to determine if abundance of clay in the bottom sediments of a Cu-contaminated aqueous ecosystem could enhance electrolytic reduction of the heavy metal. Cu(NO3)2 · 2.5H2O was added to simulate a moderately contaminated system with 650 μg Cu/ml kaolinite clay-water slurry. A constant electrical potential of 1.0 V/cm was applied across platinum wire electrodes inserted into the continuously stirred system for four days while the system ORP(2) was monitored and periodic sub-samples were taken for analysis. The electrical as well as the chemical results indicate that the quantity of Cu(II) being reduced to Cu(I), especially within the aqueous phase, is increased within the first 48 h of experimentation by the presence of kaolinite clay up to 0.05 mg clay/l slurry.

  7. Apparatus and process for the electrolytic reduction of uranium and plutonium oxides

    DOEpatents

    Poa, David S.; Burris, Leslie; Steunenberg, Robert K.; Tomczuk, Zygmunt

    1991-01-01

    An apparatus and process for reducing uranium and/or plutonium oxides to produce a solid, high-purity metal. The apparatus is an electrolyte cell consisting of a first container, and a smaller second container within the first container. An electrolyte fills both containers, the level of the electrolyte in the first container being above the top of the second container so that the electrolyte can be circulated between the containers. The anode is positioned in the first container while the cathode is located in the second container. Means are provided for passing an inert gas into the electrolyte near the lower end of the anode to sparge the electrolyte and to remove gases which form on the anode during the reduction operation. Means are also provided for mixing and stirring the electrolyte in the first container to solubilize the metal oxide in the electrolyte and to transport the electrolyte containing dissolved oxide into contact with the cathode in the second container. The cell is operated at a temperature below the melting temperature of the metal product so that the metal forms as a solid on the cathode.

  8. Deposition of silver nanoparticles on multiwalled carbon nanotubes by chemical reduction process and their antimicrobial effects

    NASA Astrophysics Data System (ADS)

    Haider, Adawiya J.; Thamir, Amin D.; Ahmed, Duha S.; Mohammad, M. R.

    2016-07-01

    In this paper, the functionalization of raw-MWCNTs involves oxidation reaction using concentrated acid mixture of HNO3:H2SO4 (1:3), via ultrasonic bath (170 W, 50 kHz) to obtain functional groups. Then Ag nanoparticles are decorated the outside over the surface of functionalized MWCNTs using a chemical reduction process resulting in the formation of(Ag/ MWCNTs) hybrid material. The results showed that outer diameter functionalized F-MWCNTs andAg nanoparticles size was about (11-80) nm and (10 to 25) nm, respectively using TEM and HRTEM. The crystallographic structure of MWCNTs using X-ray diffraction (XRD) analysis proved diffraction peaks at 38.1°, 44.3°, 64.7° and 77.4° degrees namely, Ag (111), Ag (200), Ag (220), and Ag (311) of the face-centered cubic lattice of Ag, respectively, excepting the peak at 2θ =25.6°, which correspond to the (0 0 2) reflection of the MWNTs are corresponding to Ag/MWNTs. The antimicrobial activities of Ag/MWCNTs hybrid using plate count method showed that decreasing a large number of bacteria colonies of E. coli and S. aureu with increasing the hybrid concentrations after incubation for 24h in shaker incubator with percentage of inhibition approaching 100%.

  9. Reduction and immobilization of chromate in chromite ore processing residue with nanoscale zero-valent iron.

    PubMed

    Du, Jingjing; Lu, Jinsuo; Wu, Qiong; Jing, Chuanyong

    2012-05-15

    Chromite ore processing residue (COPR) poses a great environmental and health risk with persistent Cr(VI) leaching. To reduce Cr(VI) and subsequently immobilize in the solid matrix, COPR was incubated with nanoscale zero-valent iron (nZVI) and the Cr(VI) speciation and leachability were studied. Multiple complementary analysis methods including leaching tests, X-ray powder diffraction, X-ray absorption near edge structure (XANES) spectroscopy, and X-ray photoelectron spectroscopy (XPS) were employed to investigate the immobilization mechanism. Geochemical PHREEQC model calculation agreed well with our acid neutralizing capacity experimental results and confirmed that when pH was lowered from 11.7 to 7.0, leachate Cr(VI) concentrations were in the range 358-445mgL(-1) which contributed over 90% of dissolved Cr from COPR. Results of alkaline digestion, XANES, and XPS demonstrated that incubation COPR with nZVI under water content higher than 27% could result in a nearly complete Cr(VI) reduction in solids and less than 0.1mgL(-1) Cr(VI) in the TCLP leachate. The results indicated that remediation approaches using nZVI to reduce Cr(VI) in COPR should be successful with sufficient water content to facilitate electron transfer from nZVI to COPR.

  10. Reduction, partial evaporation, and spattering - Possible chemical and physical processes in fluid drop chondrule formation

    NASA Technical Reports Server (NTRS)

    King, E. A.

    1983-01-01

    The major chemical differences between fluid drop chondrules and their probable parent materials may have resulted from the loss of volatiles such as S, H2O, Fe, and volatile siderophile elements by partial evaporation during the chondrule-forming process. Vertical access solar furnace experiments in vacuum and hydrogen have demonstrated such chemical fractionation trends using standard rock samples. The formation of immiscible iron droplets and spherules by in situ reduction of iron from silicate melt and the subsequent evaporation of the iron have been observed directly. During the time that the main sample bead is molten, many small spatter spherules are thrown off the main bead, thereby producing many additional chondrule-like melt spherules that cool rapidly and generate a population of spherules with size frequency distribution characteristics that closely approximate some populations of fluid drop chondrules in chondrites. It is possible that spatter-produced fluid drop chondrules dominate the meteoritic fluid drop chondrule populations. Such meteoritic chondrule populations should be chemically related by various relative amounts of iron and other volatile loss by vapor fractionation.

  11. Degradation of diclofenac by advanced oxidation and reduction processes: kinetic studies, degradation pathways and toxicity assessments.

    PubMed

    Yu, Hui; Nie, Er; Xu, Jun; Yan, Shuwen; Cooper, William J; Song, Weihua

    2013-04-01

    Many pharmaceutical compounds and metabolites are found in surface and ground waters suggesting their ineffective removal by conventional wastewater treatment technologies. Advanced oxidation/reduction processes (AO/RPs), which utilize free radical reactions to directly degrade chemical contaminants, are alternatives to traditional water treatment. This study reports the absolute rate constants for reaction of diclofenac sodium and model compound (2, 6-dichloraniline) with the two major AO/RP radicals: the hydroxyl radical (•OH) and hydrated electron (e(aq)(-)). The bimolecular reaction rate constants (M(-1) s(-1)) for diclofenac for •OH was (9.29 ± 0.11) × 10(9), and for e(-)(aq) was (1.53 ± 0.03) ×10(9). To provide a better understanding of the decomposition of the intermediate radicals produced by hydroxyl radical reactions, transient absorption spectra are observed from 1 - 250 μs. In addition, preliminary degradation mechanisms and major products were elucidated using (60)Co γ-irradiation and LC-MS. The toxicity of products was evaluated using luminescent bacteria. These data are required for both evaluating the potential use of AO/RPs for the destruction of these compounds and for studies of their fate and transport in surface waters where radical chemistry may be important in assessing their lifetime.

  12. Development of strategies for saving energy by temperature reduction in warm forging processes

    NASA Astrophysics Data System (ADS)

    Varela, Sonia; Santos, Maite; Vadillo, Leire; Idoyaga, Zuriñe; Valbuena, Óscar

    2016-10-01

    This paper is associated to the European policy of increasing efficiency in raw material and energy usage. This policy becomes even more important in sectors consuming high amount of resources, like hot forging industry, where material costs sums up to 50% of component price and energy ones are continuously raising. The warm forging shows a clear potential of raw material reduction (near-net-shape components) and also of energy saving (forging temperature under 1000°C). However and due to the increment of the energy costs, new solutions are required by the forging sector in order to reduce the temperature below 900°C. The reported research is based on several approaches to reduce the forging temperature applied to a flanged shaft of the automotive sector as demonstration case. The developed investigations have included several aspects: raw material, process parameters, tools and dies behavior during forging process and also metallographic evaluation of the forged parts. This paper summarizes analysis of the ductility and the admissible forces of the flanged shaft material Ck45 in as-supplied state (as-rolled) and also in two additional heat treated states. Hot compression and tensile tests using a GLEEBLE 3800C Thermo mechanical simulator have been performed pursuing this target. In the same way, a coupled numerical model based on Finite Element Method (FEM) has been developed to predict the material flow, the forging loads and the stresses on the tools at lower temperature with the new heat treatments of the raw material. In order to validate the previous development, experimental trials at 850 °C and 750 °C were carried out in a mechanical press and the results were very promising.

  13. A Processing-Centered Look at the Contribution of Givenness to Durational Reduction

    ERIC Educational Resources Information Center

    Kahn, Jason M.; Arnold, Jennifer E.

    2012-01-01

    Givenness tends to lead to acoustic reduction in speech, but little is known about whether linguistic and non-linguistic givenness affect reduction similarly, and there is little consensus about the underlying psychological mechanisms. We examined speakers' pronunciations of target object nouns in an instruction-giving task, where speakers saw…

  14. Reductive leaching of low-grade manganese ore with pre-processed cornstalk

    NASA Astrophysics Data System (ADS)

    Yi, Ai-fei; Wu, Meng-ni; Liu, Peng-wei; Feng, Ya-li; Li, Hao-ran

    2015-12-01

    Cornstalk is usually directly used as a reductant in reductive leaching manganese. However, low utilization of cornstalk makes low manganese dissolution ratio. In the research, pretreatment for cornstalk was proposed to improve manganese dissolution ratio. Cornstalk was preprocessed by a heated sulfuric acid solution (1.2 M of sulfuric acid concentration) for 10 min at 80°C. Thereafter, both the pretreated solution and the residue were used as a reductant for manganese leaching. This method not only exhibited superior activity for hydrolyzing cornstalk but also enhanced manganese dissolution. These effects were attributed to an increase in the amount of reductive sugars resulting from lignin hydrolysis. Through acid pretreatment for cornstalk, the manganese dissolution ratio was improved from 50.14% to 83.46%. The present work demonstrates for the first time the effective acid pretreatment of cornstalk to provide a cost-effective reductant for manganese leaching.

  15. Current advances of integrated processes combining chemical absorption and biological reduction for NO x removal from flue gas.

    PubMed

    Zhang, Shihan; Chen, Han; Xia, Yinfeng; Liu, Nan; Lu, Bi-Hong; Li, Wei

    2014-10-01

    Anthropogenic nitrogen oxides (NO x ) emitted from the fossil-fuel-fired power plants cause adverse environmental issues such as acid rain, urban ozone smoke, and photochemical smog. A novel chemical absorption-biological reduction (CABR) integrated process under development is regarded as a promising alternative to the conventional selective catalytic reduction processes for NO x removal from the flue gas because it is economic and environmentally friendly. CABR process employs ferrous ethylenediaminetetraacetate [Fe(II)EDTA] as a solvent to absorb the NO x following microbial denitrification of NO x to harmless nitrogen gas. Meanwhile, the absorbent Fe(II)EDTA is biologically regenerated to sustain the adequate NO x removal. Compared with conventional denitrification process, CABR not only enhances the mass transfer of NO from gas to liquid phase but also minimize the impact of oxygen on the microorganisms. This review provides the current advances of the development of the CABR process for NO x removal from the flue gas.

  16. [Treatment processes of pre-alcoholism and alcohol dependence targeted towards drinking reduction].

    PubMed

    Yoshimura, Atsushi; Maesato, Hitoshi; Hisatomi, Nobuko; Higuchi, Susumu

    2013-02-01

    Since the 1990s, we have suggested the concept of pre-alcoholism which encompasses patients who have drunk a great deal of alcohol leading to alcohol related problems such as health issues, domestic violence, drunken driving and black-outs. Pre-alcoholism excludes alcohol-dependent patients who have experienced continuous drinking or withdrawal symptoms. We have treated many outpatients with pre-alcoholism for several years. Our regimen demands that the patients must be abstinent for half a year at the beginning of their treatment. After half a year they can choose whether they will continue to be abstinent or they will resume drinking with the aim of reducing their total alcohol consumption. The study clarified the character of pre-alcoholism by investigation of the patients' background and re-diagnosis of the patients based on the International Classification of Diseases, 10th Revision (ICD-10). A remarkable ratio of pre-alcoholic patients was diagnosed with alcohol dependence under ICD-10. We classified pre-alcoholic patients into two groups, one diagnosed as having ICD-10-classed alcohol dependence and the other which did not fulfill the ICD-10 diagnostic criteria of alcohol dependence, and examined the therapeutic processes of the two groups. It was shown that most pre-alcoholic patients could finally take required courses of treatment by themselves without regard to diagnosis under ICD-10, even if they chose any treatment and made alcohol related mistakes on the way. Our findings suggested that pre-alcoholic patients, a portion of whom may have exhibited mild alcohol dependence, could select drinking reduction as a primary goal of treatment after a certain period of abstinence.

  17. Evaluating best practices for Campylobacter and Salmonella reduction in poultry processing plants.

    PubMed

    Wideman, N; Bailey, M; Bilgili, S F; Thippareddi, H; Wang, L; Bratcher, C; Sanchez-Plata, M; Singh, M

    2016-02-01

    Poultry processing plants in the United States were surveyed on their current Campylobacter and Salmonella control practices. Following surveys, data were collected to develop a baseline for prevalence rates of Salmonella and Campylobacter; then changes in practices were implemented and evaluated for improvements in pathogen control. Surveys were sent to the plant Quality Assurance managers to determine production levels, antimicrobial interventions, and current pathogen testing practices. Initial sampling was performed at 6 plants with similar production volumes, at sites that included carcass samples before any pre-evisceration intervention, after exiting the inside-outside bird washer (IOBW), after exiting the pre-chiller, after exiting the primary chiller, and after exiting any post-chill intervention, as well as a water sample from each scalder, pre-chiller, primary chiller, and post-chill dip tank or finishing chiller. Enumerations and enrichments were performed for Campylobacter and Salmonella. Following the baseline sampling, changes in practices were suggested for each plant and a second sampling was conducted to determine their effectiveness. Results demonstrated that peracetic acid (PAA) was the most effective (P < 0.05) antimicrobial currently in use. The use of a post-chill antimicrobial immersion tank and/or use of a cetylpyridinium chloride (CPC) spray cabinet also displayed a further reduction in microbial levels (P < 0.05) when the primary chiller was not sufficient (P > 0.05). Microbial buildup in the immersion tanks demonstrates the need for effective cleaning, sanitation practices, and chiller maintenance to reduce contamination of poultry with Campylobacter and Salmonella.

  18. Greek "red mud" residue: a study of microwave reductive roasting followed by magnetic separation for a metallic iron recovery process.

    PubMed

    Samouhos, Michail; Taxiarchou, Maria; Tsakiridis, Petros E; Potiriadis, Konstantinos

    2013-06-15

    The present research work is focused on the development of an alternative microwave reductive roasting process of red mud using lignite (30.15 wt.%Cfix), followed by wet magnetic separation, in order to produce a raw material suitable for sponge or cast iron production. The reduction degree of iron was controlled by both the reductive agent content and the microwave heating time. The reduction followed the Fe₂O₃ → Fe₃O₄ → FeO → Fe sequence. The dielectric constants [real (ε') and imaginary (ε″) permittivities] of red mud-lignite mixture were determined at 2.45 GHz, in the temperature range of 25-1100 °C. The effect of parameters such as temperature, intensity of reducing conditions, intensity of magnetic field and dispersing agent addition rate on the result of both processes was investigated. The phase's transformations in reduction process with microwave heating were determined by X-ray diffraction analysis (XRD) in combination with thermogravimetric/differential thermal analysis (TGA/DTA). The microstructural and morphological characterization of the produced calcines was carried out by scanning electron microscopy (SEM). At the optimum conditions a magnetic concentrate with total iron concentration of 35.15 and 69.3 wt.% metallization degree was obtained.

  19. Microfinance institutions and a coastal community's disaster risk reduction, response, and recovery process: a case study of Hatiya, Bangladesh.

    PubMed

    Parvin, Gulsan Ara; Shaw, Rajib

    2013-01-01

    Several researchers have examined the role of microfinance institutions (MFIs) in poverty alleviation, but the part that they play in disaster risk reduction remains unaddressed. Through an empirical study of Hatiya Island, one of the most vulnerable coastal communities of Bangladesh, this research evaluates perceptions of MFI support for the disaster risk reduction, response, and recovery process. The findings reveal no change in relation to risk reduction and income and occupation aspects for more than one-half of the clients of MFIs. In addition, only 26 per cent of them have witnessed less damage as a result of being members of MFIs. One can argue, though, that the longer the membership time period the better the disaster preparedness, response, and recovery process. The outcomes of this study could help to guide the current efforts of MFIs to enhance the ability of coastal communities to prepare for and to recover from disasters efficiently and effectively.

  20. Treatment of artificial soybean wastewater anaerobic effluent in a continuous aerobic-anaerobic coupled (CAAC) process with excess sludge reduction.

    PubMed

    Wang, Jun; Li, Xiaoxia; Fu, Weichao; Wu, Shihan; Li, Chun

    2012-12-01

    In this study, treatment of artificial soybean wastewater anaerobic effluent was studied in a continuous aerobic-anaerobic coupled (CAAC) process. The focus was on COD and nitrogen removal as well as excess sludge reduction. During the continuous operation without reflux, the COD removal efficiency was 96.5% at the optimal hydraulic retention time (HRT) 1.3 days. When HRT was shortened to 1.0 day, reflux from anaerobic zone to moving bed biofilm reactor (MBBR) was introduced. The removal efficiencies of COD and TN were 94.4% and 76.0% at the optimal reflux ratio 30%, respectively. The sludge yield coefficient of CAAC was 0.1738, the simultaneous removal of COD and nitrogen with in situ sludge reduction could be achieved in this CAAC process. The sludge reduction mechanism was discussed by soluble components variation along the water flow.

  1. Preparation of Nd-Fe-B by nitrate-citrate auto-combustion followed by the reduction-diffusion process

    NASA Astrophysics Data System (ADS)

    Ma, Hao Xuan; Kim, Chang Woo; Kim, Dong Soo; Jeong, Ji Hun; Kim, In Ho; Kang, Young Soo

    2015-04-01

    The Nd2Fe14B alloy has been successfully synthesized by nitrate-citrate auto-combustion followed by the reduction and diffusion process with low energy consumption. H3BO3, Fe(NO3)3.9H2O, and Nd(NO3)3.6H2O were used as precursors and citric acid was used as the chelating ligand of metal ions. Ammonia water was used to adjust pH to 7. CaH2 was used as a reducing agent for the reduction and diffusion process. NdFeO3 and Fe2O3 were produced during auto-combustion of gel. The combustion process of the gel was investigated by TGA/DTA curve measurements. The phase compositions were studied by XRD measurements. The differences of the overall morphology and magnetic properties were measured by SEM, TEM and vibrating sample magnetometry (VSM) at 300 K. The comparison of the magnetic properties of the reduced samples between the pellet type and the random powder type was done with VSM and it showed better magnetic properties of the pellet type Nd2Fe14B. Making a compact pellet type sample for reduction is more efficient for solid reduction and phase transition for higher coercivity.The Nd2Fe14B alloy has been successfully synthesized by nitrate-citrate auto-combustion followed by the reduction and diffusion process with low energy consumption. H3BO3, Fe(NO3)3.9H2O, and Nd(NO3)3.6H2O were used as precursors and citric acid was used as the chelating ligand of metal ions. Ammonia water was used to adjust pH to 7. CaH2 was used as a reducing agent for the reduction and diffusion process. NdFeO3 and Fe2O3 were produced during auto-combustion of gel. The combustion process of the gel was investigated by TGA/DTA curve measurements. The phase compositions were studied by XRD measurements. The differences of the overall morphology and magnetic properties were measured by SEM, TEM and vibrating sample magnetometry (VSM) at 300 K. The comparison of the magnetic properties of the reduced samples between the pellet type and the random powder type was done with VSM and it showed better

  2. Implementation of the U.S. Environmental Protection Agency's Waste Reduction (WAR) Algorithm in Cape-Open Based Process Simulators

    EPA Science Inventory

    The Sustainable Technology Division has recently completed an implementation of the U.S. EPA's Waste Reduction (WAR) Algorithm that can be directly accessed from a Cape-Open compliant process modeling environment. The WAR Algorithm add-in can be used in AmsterChem's COFE (Cape-Op...

  3. APPLICATIONS OF SOLVENT EXTRACTION IN THE HIGH-YIELD MULTI-PROCESS REDUCTION/SEPARATION OF Eu FROM EXCESS Sm

    SciTech Connect

    Schwantes, Jon M.; Sudowe, Ralf; Nitsche, Heino; Hoffman, Darleane C.

    2008-05-15

    A novel multi-process method for separating Eu from neighbouring lanthanides (Ln) has been developed that chemically reduces Eu(III) to Eu(II) prior to solvent extraction of Ln(III) with thenoyltrifluoroacetone in benzene. This method is capable of achieving higher purities (>99%) and separation yields than previously published multi-process methods that stabilize and separate the reduced Eu(II) as a sulphate solid and is ideal for enriching materials of high-value. Results from a variety of combinations of a chemical or electrochemical reduction process preceding a separation process using either ion exchange chromatography, reversed phase chromatography, or solvent extraction are discussed.

  4. Selective catalytic reduction system and process for treating NOx emissions using a palladium and rhodium or ruthenium catalyst

    DOEpatents

    Sobolevskiy, Anatoly; Rossin, Joseph A.; Knapke, Michael J.

    2011-07-12

    A process for the catalytic reduction of nitrogen oxides (NOx) in a gas stream (29) in the presence of H.sub.2 is provided. The process comprises contacting the gas stream with a catalyst system (38) comprising zirconia-silica washcoat particles (41), a pre-sulfated zirconia binder (44), and a catalyst combination (40) comprising palladium and at least one of rhodium, ruthenium, or a mixture of ruthenium and rhodium.

  5. Effects of post-processing treatments on sensory quality and Shiga toxigenic Escherichia coli reductions in dry-fermented sausages.

    PubMed

    Heir, E; Holck, A L; Omer, M K; Alvseike, O; Måge, I; Høy, M; Rode, T M; Sidhu, M S; Axelsson, L

    2013-05-01

    The effects of post-processing treatments on sensory quality and reduction of Shiga toxigenic Escherichia coli (STEC) in three formulations of two types of dry-fermented sausage (DFS; salami and morr) were evaluated. Tested interventions provided only marginal changes in sensory preference and characteristics. Total STEC reductions in heat treated DFS (32°C, 6days or 43°C, 24h) were from 3.5 to >5.5 log from production start. Storing of sausages (20°C, 1month) gave >1 log additional STEC reduction. Freezing and thawing of sausages in combination with storage (4°C, 1month) gave an additional 0.7 to 3.0 log reduction in STEC. Overall >5.5 log STEC reductions were obtained after storage and freezing/thawing of DFS with increased levels of glucose and salt. This study suggests that combined formulation optimisation and post-process strategies should be applicable for implementation in DFS production to obtain DFS with enhanced microbial safety and high sensory acceptance and quality.

  6. Free sulfurous acid (FSA) inhibition of biological thiosulfate reduction (BTR) in the sulfur cycle-driven wastewater treatment process.

    PubMed

    Qian, Jin; Wang, Lianlian; Wu, Yaoguo; Bond, Philip L; Zhang, Yuhan; Chang, Xing; Deng, Baixue; Wei, Li; Li, Qin; Wang, Qilin

    2017-06-01

    A sulfur cycle-based bioprocess for co-treatment of wet flue gas desulfurization (WFGD) wastes with freshwater sewage has been developed. In this process the removal of organic carbon is mainly associated with biological sulfate or sulfite reduction. Thiosulfate is a major intermediate during biological sulfate/sulfite reduction, and its reduction to sulfide is the rate-limiting step. In this study, the impacts of saline sulfite (the ionized form: HSO3(-) + SO3(2-)) and free sulfurous acid (FSA, the unionized form: H2SO3) sourced from WGFD wastes on the biological thiosulfate reduction (BTR) activities were thoroughly investigated. The BTR activity and sulfate/sulfite-reducing bacteria (SRB) populations in the thiosulfate-reducing up-flow anaerobic sludge bed (UASB) reactor decreased when the FSA was added to the UASB influent. Batch experiment results confirmed that FSA, instead of saline sulfite, was the true inhibitor of BTR. And BTR activities dropped by 50% as the FSA concentrations were increased from 8.0 × 10(-8) to 2.0 × 10(-4) mg H2SO3-S/L. From an engineering perspective, the findings of this study provide some hints on how to ensure effective thiosulfate accumulation in biological sulfate/sulfite reduction for the subsequent denitrification/denitritation. Such manipulation would result in higher nitrogen removal rates in this co-treatment process of WFGD wastes with municipal sewage.

  7. Microstructural changes in NiO–ScSZ composite following reduction processes in pure and diluted hydrogen

    SciTech Connect

    Andrzejczuk, M.; Vasylyev, O.; Brodnikovskyi, I.; Podhurska, V.; Vasyliv, B.; Ostash, O.; Lewandowska, M.; Kurzydłowski, K.J.

    2014-01-15

    A Ni–ScSZ cermet is widely used as the anode in a solid oxide fuel cell because it possesses the appropriate electrochemical properties. However, it is susceptible to degradation during operation. Samples of a NiO–ScSZ composite were reduced in pure and diluted hydrogen to determine the microstructural evolution and the degradation behavior of the material. The resulting changes in microstructure were investigated using scanning transmission electron microscopy, X-ray energy dispersive spectroscopy and electron energy loss spectroscopy. The resulting data revealed that the various conditions during the reduction processes had a significant effect on the microstructures. The high porosity of the reduced nickel phase and cracking between the Ni and the ZrO{sub 2} phases after reduction resulted in a reduction in the strength of the anode material. - Highlights: • Structure of NiO/Ni strongly depends on the concentration of reduction atmosphere • Scandium rich precipitations are visible in YSZ phase after reduction process • Nanopores and nanograins are formed in reduced Ni phase.

  8. U(VI) reduction at the nano, meso and meter scale: concomitant transition from simpler to more complex biogeochemical processes

    NASA Astrophysics Data System (ADS)

    Veeramani, H.; Hochella, M. F.

    2012-12-01

    Reduction of aqueous hexavalent U(VI) to the sparingly soluble nanoparticulate mineral uraninite [UO2] represents a promising strategy for the in situ immobilization of uranium in contaminated subsurface sediments and groundwater. Studies related to uranium reduction have been extensively carried out at various scales ranging from nano to meso to the meter scale with varying degrees of success. While nanoscale processes involving simple two-electron transfer reactions such as enzymatic microbial U(VI) reduction results in biogenic UO2 formation, mesoscale processes involving minerals and U(VI) are a step up in complexity and have shown varying results ranging from partial uranium reduction to the formation of mixed U(IV)/U(V) species. Although nano- and meso-scale biogeochemical processes have been helpful in predicting the contaminant dynamics at the meter scale, their occurrence is not necessarily apparent in soils and aquifers given the enormous volume of contaminated groundwater to be remediated, among other factors. The formation and long-term stability of biologically reduced uranium at the meter scale is also determined in addition by the complex interplay of aqueous geochemistry, hydrology, soil and sediment mineralogy and microbial community dynamics. For instance, indigenous subsurface microbes often encounter multiple electron acceptors in heterogeneous environments during biostimulation and can catalyze the formation of various reactive biogenic minerals. In such cases, abiotic interactions between U(VI) and reactive biogenic minerals is potentially important because the success of a remediation strategy is contingent upon the speciation of reduced uranium. This presentation will give an overview of uranium reduction ranging from simple nanoscale biological processes to increasingly complex meso and meter scale processes involving abiotic interactions between aqueous uranium and nano-biogenic minerals and the effect of mineralogy and aqueous

  9. The reduction process of phytic acid silver ion system: A pulse radiolysis study

    NASA Astrophysics Data System (ADS)

    Joshi, Ravi; Mukherjee, Tulsi

    2007-05-01

    Reduction of silver ion in a silver-phytic acid (1:1 ratio) system has been studied using pulse radiolysis technique. Time-resolved transformation of the intermediates, Ag +→Ag 0→Ag 2+→Ag 32+, has been clearly observed in the reduction of silver-phytic acid (1:1) system. The effect of phytic acid on the formation and decay of initial silver clusters has been also studied. The surface plasmon absorption band of stable silver nanoparticle (410 nm) and dynamic light scattering technique has been used to characterize the nanoparticles and measure the average size ( Rav=100 nm).

  10. Material and system for catalytic reduction of nitrogen oxide in an exhaust stream of a combustion process

    DOEpatents

    Gardner, Timothy J.; Lott, Stephen E.; Lockwood, Steven J.; McLaughlin, Linda I.

    1998-01-01

    A catalytic material of activated hydrous metal oxide doped with platinum, palladium, or a combination of these, and optionally containing an alkali or alkaline earth metal, that is effective for NO.sub.X reduction in an oxidizing exhaust stream from a combustion process is disclosed. A device for reduction of nitrogen oxides in an exhaust stream, particularly an automotive exhaust stream, the device having a substrate coated with the activated noble-metal doped hydrous metal oxide of the invention is also provided.

  11. Gaussian processes with built-in dimensionality reduction: Applications to high-dimensional uncertainty propagation

    SciTech Connect

    Tripathy, Rohit Bilionis, Ilias Gonzalez, Marcial

    2016-09-15

    Uncertainty quantification (UQ) tasks, such as model calibration, uncertainty propagation, and optimization under uncertainty, typically require several thousand evaluations of the underlying computer codes. To cope with the cost of simulations, one replaces the real response surface with a cheap surrogate based, e.g., on polynomial chaos expansions, neural networks, support vector machines, or Gaussian processes (GP). However, the number of simulations required to learn a generic multivariate response grows exponentially as the input dimension increases. This curse of dimensionality can only be addressed, if the response exhibits some special structure that can be discovered and exploited. A wide range of physical responses exhibit a special structure known as an active subspace (AS). An AS is a linear manifold of the stochastic space characterized by maximal response variation. The idea is that one should first identify this low dimensional manifold, project the high-dimensional input onto it, and then link the projection to the output. If the dimensionality of the AS is low enough, then learning the link function is a much easier problem than the original problem of learning a high-dimensional function. The classic approach to discovering the AS requires gradient information, a fact that severely limits its applicability. Furthermore, and partly because of its reliance to gradients, it is not able to handle noisy observations. The latter is an essential trait if one wants to be able to propagate uncertainty through stochastic simulators, e.g., through molecular dynamics codes. In this work, we develop a probabilistic version of AS which is gradient-free and robust to observational noise. Our approach relies on a novel Gaussian process regression with built-in dimensionality reduction. In particular, the AS is represented as an orthogonal projection matrix that serves as yet another covariance function hyper-parameter to be estimated from the data. To train the

  12. Gaussian processes with built-in dimensionality reduction: Applications to high-dimensional uncertainty propagation

    NASA Astrophysics Data System (ADS)

    Tripathy, Rohit; Bilionis, Ilias; Gonzalez, Marcial

    2016-09-01

    Uncertainty quantification (UQ) tasks, such as model calibration, uncertainty propagation, and optimization under uncertainty, typically require several thousand evaluations of the underlying computer codes. To cope with the cost of simulations, one replaces the real response surface with a cheap surrogate based, e.g., on polynomial chaos expansions, neural networks, support vector machines, or Gaussian processes (GP). However, the number of simulations required to learn a generic multivariate response grows exponentially as the input dimension increases. This curse of dimensionality can only be addressed, if the response exhibits some special structure that can be discovered and exploited. A wide range of physical responses exhibit a special structure known as an active subspace (AS). An AS is a linear manifold of the stochastic space characterized by maximal response variation. The idea is that one should first identify this low dimensional manifold, project the high-dimensional input onto it, and then link the projection to the output. If the dimensionality of the AS is low enough, then learning the link function is a much easier problem than the original problem of learning a high-dimensional function. The classic approach to discovering the AS requires gradient information, a fact that severely limits its applicability. Furthermore, and partly because of its reliance to gradients, it is not able to handle noisy observations. The latter is an essential trait if one wants to be able to propagate uncertainty through stochastic simulators, e.g., through molecular dynamics codes. In this work, we develop a probabilistic version of AS which is gradient-free and robust to observational noise. Our approach relies on a novel Gaussian process regression with built-in dimensionality reduction. In particular, the AS is represented as an orthogonal projection matrix that serves as yet another covariance function hyper-parameter to be estimated from the data. To train the

  13. Preparation of Nd-Fe-B by nitrate-citrate auto-combustion followed by the reduction-diffusion process.

    PubMed

    Ma, Hao Xuan; Kim, Chang Woo; Kim, Dong Soo; Jeong, Ji Hun; Kim, In Ho; Kang, Young Soo

    2015-05-07

    The Nd2Fe14B alloy has been successfully synthesized by nitrate-citrate auto-combustion followed by the reduction and diffusion process with low energy consumption. H3BO3, Fe(NO3)3·9H2O, and Nd(NO3)3·6H2O were used as precursors and citric acid was used as the chelating ligand of metal ions. Ammonia water was used to adjust pH to 7. CaH2 was used as a reducing agent for the reduction and diffusion process. NdFeO3 and Fe2O3 were produced during auto-combustion of gel. The combustion process of the gel was investigated by TGA/DTA curve measurements. The phase compositions were studied by XRD measurements. The differences of the overall morphology and magnetic properties were measured by SEM, TEM and vibrating sample magnetometry (VSM) at 300 K. The comparison of the magnetic properties of the reduced samples between the pellet type and the random powder type was done with VSM and it showed better magnetic properties of the pellet type Nd2Fe14B. Making a compact pellet type sample for reduction is more efficient for solid reduction and phase transition for higher coercivity.

  14. Dye-sensitized solar cells with reduced graphene oxide as the counter electrode prepared by a green photothermal reduction process.

    PubMed

    Yeh, Min-Hsin; Lin, Lu-Yin; Chang, Ling-Yu; Leu, Yow-An; Cheng, Wan-Yu; Lin, Jiang-Jen; Ho, Kuo-Chuan

    2014-04-14

    Highly conductive reduced graphene oxide (rGO) with good electrocatalytic ability for reducing triiodide ions (I3(-)) is a promising catalyst for the counter electrode (CE) of dye-sensitized solar cells (DSSCs). However, hazardous chemical reducing agents or energy-consuming thermal treatments are required for preparing rGO from graphene oxide (GO). Therefore, it is necessary to find other effective and green reduction processes for the preparation of rGO and to fabricate rGO-based DSSCs. In this study, GO was prepared using a modified Hummers method from graphite powder, and further reduced to rGO through a photothermal reduction process (to give P-rGO). P-rGO shows better electrocatalytic ability due mainly to its high standard heterogeneous rate constant for I3(-) reduction and in part to its considerable electrochemical surface area. The corresponding DSSC shows a higher cell efficiency (η) of 7.62% than that of the cell with a GO-based CE (η=0.03%). When the low-temperature photothermal reduction process is applied to all-flexible plastic DSSCs, the DSSC with a P-rGO CE shows an η of 4.16%.

  15. Optimization of palm oil physical refining process for reduction of 3-monochloropropane-1,2-diol (3-MCPD) ester formation.

    PubMed

    Zulkurnain, Musfirah; Lai, Oi Ming; Tan, Soo Choon; Abdul Latip, Razam; Tan, Chin Ping

    2013-04-03

    The reduction of 3-monochloropropane-1,2-diol (3-MCPD) ester formation in refined palm oil was achieved by incorporation of additional processing steps in the physical refining process to remove chloroester precursors prior to the deodorization step. The modified refining process was optimized for the least 3-MCPD ester formation and acceptable refined palm oil quality using response surface methodology (RSM) with five processing parameters: water dosage, phosphoric acid dosage, degumming temperature, activated clay dosage, and deodorization temperature. The removal of chloroester precursors was largely accomplished by increasing the water dosage, while the reduction of 3-MCPD esters was a compromise in oxidative stability and color of the refined palm oil because some factors such as acid dosage, degumming temperature, and deodorization temperature showed contradictory effects. The optimization resulted in 87.2% reduction of 3-MCPD esters from 2.9 mg/kg in the conventional refining process to 0.4 mg/kg, with color and oil stability index values of 2.4 R and 14.3 h, respectively.

  16. The NCBI Prejudice Reduction Model: A Process for Building a Multicultural Campus Community.

    ERIC Educational Resources Information Center

    Oliver, Erin A.; Slavin, Dvora

    1989-01-01

    The National Coalition Building Institute Prejudice Reduction Model, a tool for campuses to use in bringing about change in attitude and to enable people of diverse backgrounds to work together toward shared goals, is described. It teaches skills in interrupting prejudice and in conflict resolution. (MLW)

  17. Electrochemical reduction of carbon dioxide to formate with Fe-C electrodes in anaerobic sludge digestion process.

    PubMed

    Zhao, Zisheng; Zhang, Yaobin; Li, Yang; Zhao, Huimin; Quan, Xie

    2016-12-01

    Electrochemical reduction of carbon dioxide (CO2) to useful chemicals is an attractive strategy to cut its emission in atmosphere. However, high overpotential and energy consumption required in the electrochemical reduction are the major barriers of this process. In this study, a new CO2 reduction technique for production of formic acid was proposed from waste activated sludge digestion in a microbial electrosynthesis system (MES) with iron plate and carbon pillar as the electrodes. Compared with other reactors, methane production of the Fe-C MES reactor was slightly lower and CO2 was undetectable. Instead, considerable formate (672.3 mg/L) and H2 (45.8 mL) were produced in this Fe-C MES reactor, but not found in the other reactors. It should be ascribed to the reduction of CO2 and H(+) at cathode. The reduction of H(+) resulted in a weak alkaline pH (9.3), which made the methanogenesis slightly lower in Fe-C MES.

  18. Optimisation of Lime-Soda process parameters for reduction of hardness in aqua-hatchery practices using Taguchi methods.

    PubMed

    Yavalkar, S P; Bhole, A G; Babu, P V Vijay; Prakash, Chandra

    2012-04-01

    This paper presents the optimisation of Lime-Soda process parameters for the reduction of hardness in aqua-hatchery practices in the context of M. rosenbergii. The fresh water in the development of fisheries needs to be of suitable quality. Lack of desirable quality in available fresh water is generally the confronting restraint. On the Indian subcontinent, groundwater is the only source of raw water, having varying degree of hardness and thus is unsuitable for the fresh water prawn hatchery practices (M. rosenbergii). In order to make use of hard water in the context of aqua-hatchery, Lime-Soda process has been recommended. The efficacy of the various process parameters like lime, soda ash and detention time, on the reduction of hardness needs to be examined. This paper proposes to determine the parameter settings for the CIFE well water, which is pretty hard by using Taguchi experimental design method. Orthogonal Arrays of Taguchi, Signal-to-Noise Ratio, the analysis of variance (ANOVA) have been applied to determine their dosage and analysed for their effect on hardness reduction. The tests carried out with optimal levels of Lime-Soda process parameters confirmed the efficacy of the Taguchi optimisation method. Emphasis has been placed on optimisation of chemical doses required to reduce the total hardness using Taguchi method and ANOVA, to suit the available raw water quality for aqua-hatchery practices, especially for fresh water prawn M. rosenbergii.

  19. Selective recovery of pure copper nanopowder from indium-tin-oxide etching wastewater by various wet chemical reduction process: Understanding their chemistry and comparisons of sustainable valorization processes.

    PubMed

    Swain, Basudev; Mishra, Chinmayee; Hong, Hyun Seon; Cho, Sung-Soo

    2016-05-01

    Sustainable valorization processes for selective recovery of pure copper nanopowder from Indium-Tin-Oxide (ITO) etching wastewater by various wet chemical reduction processes, their chemistry has been investigated and compared. After the indium recovery by solvent extraction from ITO etching wastewater, the same is also an environmental challenge, needs to be treated before disposal. After the indium recovery, ITO etching wastewater contains 6.11kg/m(3) of copper and 1.35kg/m(3) of aluminum, pH of the solution is very low converging to 0 and contain a significant amount of chlorine in the media. In this study, pure copper nanopowder was recovered using various reducing reagents by wet chemical reduction and characterized. Different reducing agents like a metallic, an inorganic acid and an organic acid were used to understand reduction behavior of copper in the presence of aluminum in a strong chloride medium of the ITO etching wastewater. The effect of a polymer surfactant Polyvinylpyrrolidone (PVP), which was included to prevent aggregation, to provide dispersion stability and control the size of copper nanopowder was investigated and compared. The developed copper nanopowder recovery techniques are techno-economical feasible processes for commercial production of copper nanopowder in the range of 100-500nm size from the reported facilities through a one-pot synthesis. By all the process reported pure copper nanopowder can be recovered with>99% efficiency. After the copper recovery, copper concentration in the wastewater reduced to acceptable limit recommended by WHO for wastewater disposal. The process is not only beneficial for recycling of copper, but also helps to address environment challenged posed by ITO etching wastewater. From a complex wastewater, synthesis of pure copper nanopowder using various wet chemical reduction route and their comparison is the novelty of this recovery process.

  20. Pyrolysis Treatment of Chromite Ore Processing Residue by Biomass: Cellulose Pyrolysis and Cr(VI) Reduction Behavior.

    PubMed

    Zhang, Da-Lei; Zhang, Mei-Yi; Zhang, Chu-Hui; Sun, Ying-Jie; Sun, Xiao; Yuan, Xian-Zheng

    2016-03-15

    The pyrolysis treatment with biomass is a promising technology for the remediation of chromite-ore-processing residue (COPR). However, the mechanism of this process is still unclear. In this study, the behavior of pyrolysis reduction of Cr(VI) by cellulose, the main component of biomass, was elucidated. The results showed that the volatile fraction (VF) of cellulose, ie. gas and tar, was responsible for Cr(VI) reduction. All organic compounds, as well as CO and H2 in VF, potentially reduced Cr(VI). X-ray absorption near-edge structure (XANES) spectroscopy and extended X-ray absorption fine-structure (EXAFS) spectroscopy confirmed the reduction of Cr(VI) to Cr(III) and the formation of amorphous Cr2O3. The remnant Cr(VI) content in COPR can be reduced below the detection limit (2 mg/kg) by the reduction of COPR particle and extension of reaction time between VF and COPR. This study provided a deep insight on the co-pyrolysis of cellulose with Cr(VI) in COPR and an ideal approach by which to characterize and optimize the pyrolysis treatment for COPR by other organics.

  1. Recovery of iron and calcium aluminate slag from high-ferrous bauxite by high-temperature reduction and smelting process

    NASA Astrophysics Data System (ADS)

    Zhang, Ying-yi; Lü, Wei; Qi, Yuan-hong; Zou, Zong-shu

    2016-08-01

    A high-temperature reduction and smelting process was used to recover iron and calcium aluminate slag from high-ferrous bauxite. The effects of w(CaO)/ w(SiO2) ratio, anthracite ratio, and reduction temperature and time on the recovery and size of iron nuggets and on the Al2O3 grade of the calcium aluminate slag were investigated through thermodynamic calculations and experiments. The optimized process conditions were the bauxite/anthracite/slaked lime weight ratio of 100:16.17:59.37, reduction temperature of 1450°C and reduction time of 20 min. Under these conditions, high-quality iron nuggets and calcium aluminate slag were obtained. The largest size and the highest recovery rate of iron nuggets were 11.42 mm and 92.79wt%, respectively. The calcium aluminate slag mainly comprised Ca2SiO4 and Ca12Al14O33, with small amounts of FeAl2O4, CaAl2O4, and Ca2Al2SiO7.

  2. Identification of the sources of nitrous oxide produced by oxidative and reductive processes in Nitrosomonas europaea

    PubMed Central

    Ritchie, G. A. F.; Nicholas, D. J. D.

    1972-01-01

    1. Cells of Nitrosomonas europaea produced N2O during the oxidation of ammonia and hydroxylamine. 2. The end-product of ammonia oxidation, nitrite, was the predominant source of N2O in cells. 3. Cells also produced N2O, but not N2 gas, by the reduction of nitrite under anaerobic conditions. 4. Hydroxylamine was oxidized by cell-free extracts to yield nitrite and N2O aerobically, but to yield N2O and NO anaerobically. 5. Cell extracts reduced nitrite both aerobically and anaerobically to NO and N2O with hydroxylamine as an electron donor. 6. The relative amounts of NO and N2O produced during hydroxylamine oxidation and/or nitrite reduction are dependent on the type of artificial electron acceptor utilized. 7. Partially purified hydroxylamine oxidase retained nitrite reductase activity but cytochrome oxidase was absent. 8. There is a close association of hydroxylamine oxidase and nitrite reductase activities in purified preparations. PMID:5073730

  3. Fabrication of ultrafine tungsten-based alloy powders by novel soda reduction process

    SciTech Connect

    Lee, Dong-Won; Turaev, Farkhod; Kim, Ju-Hyeong; Yang, Mingchuan

    2010-03-15

    A novel reduction method has been developed to fabricate ultrafine tungsten heavy alloy powders, with ammonium metatungstate (AMT), iron(II) chloride tetrahydrate (FeCl{sub 2}.4H{sub 2}O), nickel(II) chloride hexahydrate (NiCl{sub 2}.6H{sub 2}O) as source materials and sodium tungstate dihydrate (Na{sub 2}WO{sub 4}.2H{sub 2}O) as a reductant. In the preparation of mixtures the amounts of the source components were chosen so as to obtain alloy of 93W-5Ni-2Fe composition (wt.%). The obtained powders were characterized by X-ray diffraction, XPS, field-emission scanning microscope (FESEM), and chemical composition was analyzed by EDX.

  4. Field Demonstration of a Novel Biotreatment Process for Perchlorate Reduction in Groundwater

    DTIC Science & Technology

    2010-06-01

    biological reduction and/or reaction with ZVI, and arsenic hexavalent chromium and/or uranium by adsorption on corrosion products. • Simple rugged...problems and troubleshooting measures ................................... 22 5.2 Laboratory Evaluation of Porosity Decrease and Corrosion Products...reactor when it was dismantled showing the heavy deposits of iron corrosion products and quasi total loss of porosity. Figure 5.14 Picture of the column

  5. Interaction of abiotic and microbial processes in hexachloroethane reduction in groundwater

    USGS Publications Warehouse

    Roberts, A. Lynn; Gschwend, Philip M.

    1994-01-01

    In order to gain insight into mechanisms of hexachloroethane reduction, hexa- and pentachloroethane transformation rates were measured in anaerobic groundwater samples. For samples spiked with pentachloroethane, disappearance of pentachloroethane was accompanied by tetrachloroethylene production. Transformation rates were similar in unpoisoned and in HgCl2-poisoned samples, and rates were within ±20% of predictions based on measured pH and second-order dehydrochlorination rate constants determined in clean laboratory systems, indicating that the fate of pentachloroethane in this system is dominated by abiotic reactions. No hexachloroethane transformation was observed in HgCl2-poisoned samples, whereas in unpoisoned samples, hexachloroethane disappearance was accompanied by production of tetrachloroethylene as well as traces of pentachloroethane. Although only minor amounts of pentachloroethane accumulated, as much as 30% of the hexachloroethane transformation pathway proceeds via a pentachloroethane intermediate. This suggests that the microbial reduction of hexachloroethane proceeds at least in part through a free-radical mechanism. To the extent that hexachloroethane reduction to tetrachloroethylene occurs through a pentachloroethane intermediate, the first step in the sequence, the microbially-mediated step, is the slow step; the subsequent abiotic dehydrohalogenation step occurs much more rapidly.

  6. Reduction of greenhouse gases emissions during anoxic wastewater treatment by strengthening nitrite-dependent anaerobic methane oxidation process.

    PubMed

    Ma, Ru; Hu, Zhen; Zhang, Jian; Ma, Hao; Jiang, Liping; Ru, Dongyun

    2017-03-20

    Nitrite-dependent anaerobic methane oxidation (n-damo) is a recently discovered process performed by NC10 phylum, which plays an important role in greenhouse gases (GHG) reduction. In this study, co-existence of n-damo bacteria and methanogens was successfully achieved by using upflow anaerobic sludge blanket (UASB) reactor. Reactor with inorganic carbon source (CO2/H2) showed the highest abundance of n-damo bacteria and the highest n-damo potential activity, resulted in its highest nitrogen removal rate. Significant reduction in GHG was obtained after introduction of n-damo process, especially for N2O. Furthermore, GHG emissions decreased with the increase of n-damo bacteria abundance. Community structure analysis found carbon source could influence the diversity of n-damo bacteria indirectly. And phylogenetic analysis showed that all the obtained sequences were assigned to group B, mainly due to in situ production and consumption of CH4.

  7. Assessment of the GHG Reduction Potential from Energy Crops Using a Combined LCA and Biogeochemical Process Models: A Review

    PubMed Central

    Jiang, Dong; Hao, Mengmeng; Wang, Qiao; Huang, Yaohuan; Fu, Xinyu

    2014-01-01

    The main purpose for developing biofuel is to reduce GHG (greenhouse gas) emissions, but the comprehensive environmental impact of such fuels is not clear. Life cycle analysis (LCA), as a complete comprehensive analysis method, has been widely used in bioenergy assessment studies. Great efforts have been directed toward establishing an efficient method for comprehensively estimating the greenhouse gas (GHG) emission reduction potential from the large-scale cultivation of energy plants by combining LCA with ecosystem/biogeochemical process models. LCA presents a general framework for evaluating the energy consumption and GHG emission from energy crop planting, yield acquisition, production, product use, and postprocessing. Meanwhile, ecosystem/biogeochemical process models are adopted to simulate the fluxes and storage of energy, water, carbon, and nitrogen in the soil-plant (energy crops) soil continuum. Although clear progress has been made in recent years, some problems still exist in current studies and should be addressed. This paper reviews the state-of-the-art method for estimating GHG emission reduction through developing energy crops and introduces in detail a new approach for assessing GHG emission reduction by combining LCA with biogeochemical process models. The main achievements of this study along with the problems in current studies are described and discussed. PMID:25045736

  8. Assessment of the GHG reduction potential from energy crops using a combined LCA and biogeochemical process models: a review.

    PubMed

    Jiang, Dong; Hao, Mengmeng; Fu, Jingying; Wang, Qiao; Huang, Yaohuan; Fu, Xinyu

    2014-01-01

    The main purpose for developing biofuel is to reduce GHG (greenhouse gas) emissions, but the comprehensive environmental impact of such fuels is not clear. Life cycle analysis (LCA), as a complete comprehensive analysis method, has been widely used in bioenergy assessment studies. Great efforts have been directed toward establishing an efficient method for comprehensively estimating the greenhouse gas (GHG) emission reduction potential from the large-scale cultivation of energy plants by combining LCA with ecosystem/biogeochemical process models. LCA presents a general framework for evaluating the energy consumption and GHG emission from energy crop planting, yield acquisition, production, product use, and postprocessing. Meanwhile, ecosystem/biogeochemical process models are adopted to simulate the fluxes and storage of energy, water, carbon, and nitrogen in the soil-plant (energy crops) soil continuum. Although clear progress has been made in recent years, some problems still exist in current studies and should be addressed. This paper reviews the state-of-the-art method for estimating GHG emission reduction through developing energy crops and introduces in detail a new approach for assessing GHG emission reduction by combining LCA with biogeochemical process models. The main achievements of this study along with the problems in current studies are described and discussed.

  9. Method for oxygen reduction in a uranium-recovery process. [US DOE patent application

    DOEpatents

    Hurst, F.J.; Brown, G.M.; Posey, F.A.

    1981-11-04

    An improvement in effecting uranium recovery from phosphoric acid solutions is provided by sparging dissolved oxygen contained in solutions and solvents used in a reductive stripping stage with an effective volume of a nonoxidizing gas before the introduction of the solutions and solvents into the stage. Effective volumes of nonoxidizing gases, selected from the group consisting of argon, carbon dioxide, carbon monoxide, helium, hydrogen, nitrogen, sulfur dioxide, and mixtures thereof, displace oxygen from the solutions and solvents thereby reduce deleterious effects of oxygen such as excessive consumption of elemental or ferrous iron and accumulation of complex iron phosphates or cruds.

  10. Application of Carbon Isotope Fractionation during the Reduction Process from CO 2 to CH 4

    NASA Astrophysics Data System (ADS)

    Li, Jin; Hu, Guoyi; Zhang, Ying; Yang, Guifang; Cui, Huiying; Cao, Hongming; Hu, Xülong

    The CO 2 reduced to CH 4 pathway is important for the generation of biogas in the geological history. The Quaternary biogenic gas fields in Qaidam Basin of China belong to the CO 2/H 2 reduction biogenic gas. According to the theory of H 2/CO 2 reduction, we have carried out the biosimulation experiments with different occurrences and different initial carbon isotope values of carbon sources. The experimental results indicate that there is a positive correlation between the δ 13C methane values and the δ 13C values of the substrate in products; In response to the existence of excessive substrate, the occurrence of substrate has its effect on the δ 13C methane values. The δ 13C methane values from free CO 2 reduced to CH 4 is relatively lower than those coming from HCO 3- and CO 32- ions. By applying to the Quaternary biogenic gas filed in the east of Qaidam Basin, the source and occurrences of the main substrate CO 2 are discussed, and these have import reference significance for evaluating the biogas resources and searching for favorable exploration areas.

  11. Effect of calcination temperature on the photocatalytic reduction and oxidation processes of hydrothermally synthesized titania nanotubes.

    SciTech Connect

    Viayan, B.; Dimitrijevic, N. M.; Rajh, T.; Gray, K.; Northwestern Univ.

    2010-08-05

    Titania nanotubes having diameters 8 to 12 nm and lengths of 50-300 nm were prepared using a hydrothermal method. Further, the titania nanotubes were calcined over the temperature range 200-800 C in order to enhance their photocatalytic properties by altering their morphology. The calcined titania nanotubes were characterized by using X-ray diffraction and surface area analysis and their morphological features were studied by scanning and transmission electron microscopy. Nanotubes calcined at 400 C showed the maximum extent of photocatalyitc reduction of carbon dioxide to methane, whereas samples calcined at 600 C produced maximum photocatalytic oxidation of acetaldehyde. Electron paramagnetic resonance (EPR) spectroscopy was used to interrogate the effects of nanotube structure on the charge separation and trapping as a function of calcination temperature. EPR results indicated that undercoordinated titania sites are associated with maximum CO{sub 2} reduction occurring in nanotubes calcined at 400 C. Despite the collapse of the nantube structure to form nanorods and the concomitant loss of surface area, the enhanced charge separation associated with increased crystallinity promoted high rates of oxidation of acetaldehyde in titania materials calcined at 600 C. These results illustrate that calcination temperature allows us to tune the morphological and surface features of the titania nanostructures for particular photocatalytic reactions.

  12. Immobilized redox mediator on metal-oxides nanoparticles and its catalytic effect in a reductive decolorization process.

    PubMed

    Alvarez, L H; Perez-Cruz, M A; Rangel-Mendez, J R; Cervantes, F J

    2010-12-15

    Different metal-oxides nanoparticles (MONP) including α-Al(2)O(3), ZnO and Al(OH)(3), were utilized as adsorbents to immobilize anthraquinone-2,6-disulfonate (AQDS). Immobilized AQDS was subsequently tested as a solid-phase redox mediator (RMs) for the reductive decolorization of the azo dye, reactive red 2 (RR2), by anaerobic sludge. The highest adsorption capacity of AQDS was achieved on Al(OH)(3) nanoparticles, which was ∼0.16 mmol g(-1) at pH 4. Immobilized AQDS increased up to 7.5-fold the rate of decolorization of RR2 by anaerobic sludge as compared with sludge incubations lacking AQDS. Sterile controls including immobilized AQDS did not show significant (<3.5%) RR2 decolorization, suggesting that physical-chemical processes (e.g. adsorption or chemical reduction) were not responsible for the enhanced decolorization achieved. Immobilization of AQDS on MONP was very stable under the applied experimental conditions and spectrophotometric screening did not detect any detachment of AQDS during the reductive decolorization of RR2, confirming that immobilized AQDS served as an effective RMs. The present study constitutes the first demonstration that immobilized quinones on MONP can serve as effective RMs in the reductive decolorization of an azo dye. The immobilizing technique developed could be applied in anaerobic wastewater treatment systems to accelerate the redox biotransformation of recalcitrant pollutants.

  13. Comparative reduction of Giardia cysts, F+ coliphages, sulphite reducing clostridia and fecal coliforms by wastewater treatment processes.

    PubMed

    Nasser, Abidelfatah M; Benisti, Neta-Lee; Ofer, Naomi; Hovers, Sivan; Nitzan, Yeshayahu

    2017-01-28

    Advanced wastewater treatment processes are applied to prevent the environmental dissemination of pathogenic microorganisms. Giardia lamblia causes a severe disease called giardiasis, and is highly prevalent in untreated wastewater worldwide. Monitoring the microbial quality of wastewater effluents is usually based on testing for the levels of indicator microorganisms in the effluents. This study was conducted to compare the suitability of fecal coliforms, F+ coliphages and sulfide reducing clostridia (SRC) as indicators for the reduction of Giardia cysts in two full-scale wastewater treatment plants. The treatment process consists of activated sludge, coagulation, high rate filtration and either chlorine or UV disinfection. The results of the study demonstrated that Giardia cysts are highly prevalent in raw wastewater at an average concentration of 3600 cysts/L. Fecal coliforms, F+ coliphages and SRC were also detected at high concentrations in raw wastewater. Giardia cysts were efficiently removed (3.6 log10) by the treatment train. The greatest reduction was observed for fecal coliforms (9.6 log10) whereas the least reduction was observed for F+ coliphages (2.1 log10) following chlorine disinfection. Similar reduction was observed for SRC by filtration and disinfection by either UV (3.6 log10) or chlorine (3.3 log10). Since F+ coliphage and SRC were found to be more resistant than fecal coliforms for the tertiary treatment processes, they may prove to be more suitable as indicators for Giardia. The results of this study demonstrated that advanced wastewater treatment may prove efficient for the removal of Giardia cysts and may prevent its transmission when treated effluents are applied for crop irrigation or streams restoration.

  14. 40 CFR 63.1427 - Process vent requirements for processes using extended cookout as an epoxide emission reduction...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... process knowledge, reaction kinetics, and engineering knowledge, in accordance with paragraph (a)(2)(i) of... accordance with paragraph (f)(1)(i) of this section, or reaction kinetics in accordance with paragraph (f)(1... epoxide in the reactor liquid at the beginning of the time period, weight percent. k = Reaction...

  15. Reduction of nitrous oxide emissions from biological nutrient removal processes by thermal decomposition.

    PubMed

    Pedros, Philip B; Askari, Omid; Metghalchi, Hameed

    2016-12-01

    During the last decade municipal wastewater treatment plants have been regulated with increasingly stringent nutrient removal requirements including nitrogen. Typically biological treatment processes are employed to meet these limits. Although the nitrogen in the wastewater stream is reduced, certain steps in the biological processes allow for the release of gaseous nitrous oxide (N2O), a greenhouse gas (GHG). A comprehensive study was conducted to investigate the potential to mitigate N2O emissions from biological nutrient removal (BNR) processes by means of thermal decomposition. The study examined using the off gases from the biological process, instead of ambient air, as the oxidant gas for the combustion of biomethane. A detailed analysis was done to examine the concentration of N2O and 58 other gases that exited the combustion process. The analysis was based on the assumption that the exhaust gases were in chemical equilibrium since the residence time in the combustor is sufficiently longer than the chemical characteristics. For all inlet N2O concentrations the outlet concentrations were close to zero. Additionally, the emission of hydrogen sulfide (H2S) and ten commonly occurring volatile organic compounds (VOCs) were also examined as a means of odor control for biological secondary treatment processes or as potential emissions from an anaerobic reactor of a BNR process. The sulfur released from the H2S formed sulfur dioxide (SO2) and eight of the ten VOCs were destroyed.

  16. Waste reduction and process improvements in the analysis of plutonium by x-ray fluorescence

    SciTech Connect

    Worley, Christopher G; Sodweberg, Constance B; Townsend, Lisa E

    2009-01-01

    Significant modifications were made to a sample preparation process for quantifying gallium in plutonium metal by wavelength dispersive X-ray fluorescence. These changes were made to minimize waste and improve process safety and efficiency. Sample sizes were reduced, cheaper sample preparation acids were used, and safety improvements were implemented. Using this modified process, results from analyzing a batch oftest samples indicated that relative precision and accuracy were {approx}0.2% and {approx}0.1% respectively, which is comparable to that obtained using the older, established sample preparation method.

  17. Learning Processes and Trajectories for the Reduction of Antibiotic Use in Pig Farming: A Qualitative Approach

    PubMed Central

    Fortané, Nicolas; Bonnet-Beaugrand, Florence; Hémonic, Anne; Samedi, Carole; Savy, Arnaud; Belloc, Catherine

    2015-01-01

    Since 2011, French public policy has been encouraging a reduction in the use of antibiotics in animal farming. The aim of this article is to look at how some farms have already managed to lower their consumption of antibiotics, and to highlight the levers of change in farming health practices. Our research uses a qualitative study based on 21 semi-structured interviews with farmers and veterinarians in the French pig-farming sector. We use the notion of “trajectory of change” to examine, over time, the intersection of the technical, economic, social and organisational determinants which affect the reduced use of antibiotics. The “learning process” concept makes it possible to take account of the way in which the actors assimilate, appropriate and implement new health practices. We have identified three interdependent levels of learning: technical learning, cognitive learning and organisational learning. PMID:27025634

  18. Preparation of Si3N4 Form Diatomite via a Carbothermal Reduction-Nitridation Process

    NASA Astrophysics Data System (ADS)

    Ma, Bin; Huang, Zhaohui; Mei, Lefu; Fang, Minghao; Liu, Yangai; Wu, Xiaowen; Hu, Xiaozhi

    2016-05-01

    Si3N4 was produced using diatomite and sucrose as silicon and carbon sources, respectively. The effect of the C/SiO2 molar ratio, heating temperature and soaking time on the morphology and phase compositions of the final products was investigated by scanning electron microscopy, x-ray diffraction analysis and energy dispersive spectroscopy. The phase equilibrium relationships of the system at different heating temperatures were also investigated based on the thermodynamic analysis. The results indicate that the phase compositions depended on the C/SiO2 molar ratio, heating temperature and soaking time. Fabrication of Si3N4 from the precursor via carbothermal reduction nitridation was achieved at 1550°C for 1-8 h using a C/SiO2 molar ratio of 3.0. The as-prepared Si3N4 contained a low amount of Fe3Si (<1 wt.%).

  19. Pyrite oxidation and reduction - Molecular orbital theory considerations. [for geochemical redox processes

    NASA Technical Reports Server (NTRS)

    Luther, George W., III

    1987-01-01

    In this paper, molecular orbital theory is used to explain a heterogeneous reaction mechanism for both pyrite oxidation and reduction. The mechanism demonstrates that the oxidation of FeS2 by Fe(3+) may occur as a result of three important criteria: (1) the presence of a suitable oxidant having a vacant orbital (in case of liquid phase) or site (solid phase) to bind to the FeS2 via sulfur; (2) the initial formation of a persulfido (disulfide) bridge between FeS2 and the oxidant, and (3) an electron transfer from a pi(asterisk) orbital in S2(2-) to a pi or pi(asterisk) orbital of the oxidant.

  20. Post-Harvest Processing Methods for Reduction of Silica and Alkali Metals in Wheat Straw

    SciTech Connect

    Thompson, David Neal; Lacey, Jeffrey Alan; Shaw, Peter Gordon

    2002-04-01

    Silica and alkali metals in wheat straw limit its use for bioenergy and gasification. Slag deposits occur via the eutectic melting of SiO2 with K2O, trapping chlorides at surfaces and causing corrosion. A minimum melting point of 950°C is desirable, corresponding to SiO2:K2O of about 3:1. Mild chemical treatments were used to reduce Si, K, and Cl, while varying temperature, concentration, %-solids, and time. Dilute acid was more effective at removing K and Cl, while dilute alkali was more effective for Si. Reduction of minerals in this manner may prove economical for increasing utilization of the straw for combustion or gasification.

  1. Post-harvest processing methods for reduction of silica and alkali metals in wheat straw.

    PubMed

    Thompson, David N; Shaw, Peter G; Lacey, Jeffrey A

    2003-01-01

    Silica and alkali metals in wheat straw limit its use for bioenergy and gasification. Slag deposits occur via the eutectic melting of SiO2 with K2O, trapping chlorides at surfaces and causing corrosion. A minimum melting point of 950 degrees C is desirable, corresponding to an SiO2:K2O weight ratio of about 3:1. Mild chemical treatments were used to reduce Si, K, and Cl, while varying temperature, concentration, % solids, and time. Dilute acid was more effective at removing K and Cl, while dilute alkali was more effective for Si. Reduction of minerals in this manner may prove economical for increasing utilization of the straw for combustion or gasification.

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

    USGS Publications Warehouse

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

    1998-01-01

    The mineralogy, contents, and isotopic compositions of sulfur in oceanic serpentinites reflect variations in temperatures and fluid fluxes. Serpentinization of <1 Ma peridotites at Hess Deep occurred at high temperatures (200??-400??C) and low water/rock ratios. Oxidation of ferrous iron to magnetite maintained low fO2and produced a reduced, low-sulfur assemblage including NiFe alloy. Small amounts of sulfate reduction by thermophilic microbes occurred as the system cooled, producing low-??34S sulfide (1.5??? to -23.7???). In contrast, serpentinization of Iberian Margin peridotites occurred at low temperatures (???20??-200??C) and high water/rock ratios. Complete serpentinization and consumption of ferrous iron allowed evolution to higher fO2. Microbial reduction of seawater sulfate resulted in addition of low-??34S sulfide (-15 to -43???) and formation of higher-sulfur assemblages that include valleriite and pyrite. The high SO4/total S ratio of Hess Deep serpentinites (0.89) results in an increase of total sulfur and high ??34S of total sulfur (mean ??? 8???). In contrast, Iberian Margin serpentinites gained large amounts of 34S-poor sulfide (mean total S = 3800 ppm), and the high sulfide/total S ratio (0.61) results in a net decrease in ??34S of total sulfur (mean ??? -5???). Thus serpentinization is a net sink for seawater sulfur, but the amount fixed and its isotopic composition vary significantly. Serpentinization may result in uptake of 0.4-14 ?? 1012 g S yr-1 from the oceans, comparable to isotopic exchange in mafic rocks of seafloor hydrothermal systems and approaching global fluxes of riverine sulfate input and sedimentary sulfide output.

  3. MERCURY REDUCTION IN PRODUCTS AND PROCESSES: A REVIEW OF THE ELECTRICAL AND ELECTRONIC INDUSTRIES

    EPA Science Inventory

    The electrical and electronics industries have significantly reduced the amount of mercury from various products and processes. However, the unique electromechanical and photoelectronic properties of mercury and mercury compounds have made replacement of mercury difficult in some...

  4. Exploring the fundamentals of radical assisted NO{sub x} reduction processes of coal combustors. Final report

    SciTech Connect

    Chess, K.; Yao, S.C.; Russell, A.G.

    1996-05-31

    This report describes experimental studies performed at Carnegie Mellon University to study the parameters that affect the performance of plasma-assisted ammonia radical injection for NO{sub x} control from stationary combustion sources. First, the NO{sub x} reduction potential of hot ammonia injection was studied to determine whether the use of the plasma for radical generation was key to the high NO{sub x} reduction potential of the plasma deNO{sub x} process. It was found that while some of the NO{sub x} reduction in the plasma deNO{sub x} demonstration experiments could be attributed to the enhanced thermal breakdown of NH{sub 3} into NO{sub x} reducing radicals, the effect of using the plasma accounted for 15--35% absolute additional NO{sub x} reduction beyond any thermal benefit. This benefit of using the plasma increases with increased excess air and decreased flue gas temperature. With the benefit of using the plasma verified on the larger scale of a demonstration experiment, two additional experiments were performed to study the parameters that affect plasma deNO{sub x} performance on the local level. The opposed flow experiment failed to produce significant NO{sub x} reduction, although it did highlight some key aspects of plasma performance with ammonia injection. The reverse injection experiment successfully demonstrated the effects of NO-stream temperature, plasma power, and ammonia flow rate on plasma deNO{sub x} performance. Finally, a preliminary study of the chemical kinetics of the plasma deNO{sub x} system was performed. This study highlighted the importance of effective plasma temperature and the residence time of the reagent at that temperature to efficient radical generation.

  5. Experimental and modeling study of the effects of multicomponent gas additives on selective non-catalytic reduction process.

    PubMed

    Cao, Qingxi; Wu, Shaohua; Lui, Hui; Liu, Dunyu; Qiu, Penghua

    2009-08-01

    The influence of multicomponent additives on NO reduction by selective non-catalytic reduction process has been investigated experimentally in an electricity-heated tube reactor. The multicomponent additives are composed of two species of CO, CH(4) and H(2), and the molar ratio of their two components varies from 1/3 to 3/1. The results show that all the investigated additives could decrease the optimal temperature for NO reduction effectively, but the contributions of their components are different. The performance of multicomponent additive composed of CO and CH(4) depends mainly on CH(4) component. The function of CO component is shifting the temperature window for NO reduction to lower temperature slightly and narrowing the temperature window a little. The temperature window with multicomponent additive composed of H(2) and CH(4) is distinct from that with its each component, so both H(2) and CH(4) component make important contributions. While the fraction of CO is no more than that of H(2) in multicomponent additives composed of them, the performance of multicomponent additives is dominated by H(2) component; while the fraction of CO becomes larger, the influence of CO component becomes notable. Qualitatively the modeling results using a detailed chemical kinetic mechanism exhibit the same characteristics of the temperature window shift as observed experimentally. By reaction mechanism analysis, the distinct influences of CO, CH(4) or H(2) component on the property of multicomponent additive are mainly caused by the different production rates of (*)OH radical in their own oxidation process.

  6. The demonstration of a novel sulfur cycle-based wastewater treatment process: sulfate reduction, autotrophic denitrification, and nitrification integrated (SANI®) biological nitrogen removal process.

    PubMed

    Lu, Hui; Wu, Di; Jiang, Feng; Ekama, George A; van Loosdrecht, Mark C M; Chen, Guang-Hao

    2012-11-01

    Saline water supply has been successfully practiced for toilet flushing in Hong Kong since 1950s, which saves 22% of freshwater in Hong Kong. In order to extend the benefits of saline water supply into saline sewage management, we have recently developed a novel biological organics and nitrogen removal process: the Sulfate reduction, Autotrophic denitrification, and Nitrification Integrated (SANI®) process. The key features of this novel process include elimination of oxygen demand in organic matter removal and production of minimal sludge. Following the success of a 500-day lab-scale trial, this study reports a pilot scale evaluation of this novel process treating 10 m(3) /day of 6-mm screened saline sewage in Hong Kong. The SANI® pilot plant consisted of a sulfate reduction up-flow sludge bed (SRUSB) reactor, an anoxic bioreactor for autotrophic denitrification and an aerobic bioreactor for nitrification. The plant was operated at a steady state for 225 days, during which the average removal efficiencies of both chemical oxygen demand (COD) and total suspended solids (TSS) at 87% and no excess sludge was purposefully withdrawn. Furthermore, a tracer test revealed 5% short circuit flow and a 34.6% dead zone in the SRUSB, indicating a good possibility to further optimize the treatment capacity of the process for full-scale application. Compared with conventional biological nitrogen removal processes, the SANI® process reduces 90% of waste sludge, which saves 35% of the energy and reduces 36% of fossil CO(2) emission. The SANI® process not only eliminates the major odor sources originating from primary treatment and subsequent sludge treatment and disposal during secondary saline sewage treatment, but also promotes saline water supply as an economic and sustainable solution for water scarcity and sewage treatment in water-scarce coastal areas.

  7. Energy Saving Melting and Revert Reduction Technology: Innovative Semi-Solid Metal (SSM) Processing

    SciTech Connect

    Diran Apelian

    2012-08-15

    Semi-solid metal (SSM) processing has emerged as an attractive method for near-net-shape manufacturing due to the distinct advantages it holds over conventional near-net-shape forming technologies. These advantages include lower cycle time, increased die life, reduced porosity, reduced solidification shrinkage, improved mechanical properties, etc. SSM processing techniques can not only produce the complex dimensional details (e.g. thin-walled sections) associated with conventional high-pressure die castings, but also can produce high integrity castings currently attainable only with squeeze and low-pressure permanent mold casting processes. There are two primary semi-solid processing routes, (a) thixocasting and (b) rheocasting. In the thixocasting route, one starts from a non-dendritic solid precursor material that is specially prepared by a primary aluminum manufacturer, using continuous casting methods. Upon reheating this material into the mushy (a.k.a. "two-phase") zone, a thixotropic slurry is formed, which becomes the feed for the casting operation. In the rheocasting route (a.k.a. "slurry-on-demand" or "SoD"), one starts from the liquid state, and the thixotropic slurry is formed directly from the melt via careful thermal management of the system; the slurry is subsequently fed into the die cavity. Of these two routes, rheocasting is favored in that there is no premium added to the billet cost, and the scrap recycling issues are alleviated. The CRP (Trade Marked) is a process where the molten metal flows through a reactor prior to casting. The role of the reactor is to ensure that copious nucleation takes place and that the nuclei are well distributed throughout the system prior to entering the casting cavity. The CRP (Trade Marked) has been successfully applied in hyper-eutectic Al-Si alloys (i.e., 390 alloy) where two liquids of equal or different compositions and temperatures are mixed in the reactor and creating a SSM slurry. The process has been mostly

  8. Gamma radiation in the reduction of S almonella spp. inoculated on minimally processed watercress ( Nasturtium officinalis)

    NASA Astrophysics Data System (ADS)

    Martins, C. G.; Behrens, J. H.; Destro, M. T.; Franco, B. D. G. M.; Vizeu, D. M.; Hutzler, B.; Landgraf, M.

    2004-09-01

    Consumer attitudes towards foods have changed in the last two decades increasing requirements for freshlike products. Consequently, less extreme treatments or additives are being required. Minimally processed foods have freshlike characteristics and satisfy this new consumer demand. Besides freshness, the minimally processing also provide convenience required by the market. Salad vegetables can be source of pathogen such as Salmonella, Escherichia coli O157:H7, Shigella spp. The minimal processing does not reduce the levels of pathogenic microorganisms to safe levels. Therefore, this study was carried out in order to improve the microbiological safety and the shelf-life of minimally processed vegetables using gamma radiation. Minimally processed watercress inoculated with a cocktail of Salmonella spp was exposed to 0.0, 0.2, 0.5, 0.7, 1.0, 1.2 and 1.5 kGy. Irradiated samples were diluted 1:10 in saline peptone water and plated onto tryptic soy agar that were incubated at 37°C/24 h. D 10 values for Salmonella spp. inoculated in watercress varied from 0.29 to 0.43 kGy. Therefore, a dose of 1.7 kGy will reduce Salmonella population in watercress by 4 log 10. The shelf-life was increased by 1 {1}/{2} day when the product was exposed to 1 kGy.

  9. High Permeate Recovery for Concentrate Reduction by Integrated Membrane Process in Textile Effluent.

    PubMed

    Sudhakar, M; Vijayalakshmi, P; Nilavunesan, D; Thiruvengadaravi, K V; Baskaralingam, P; Sivanesan, S

      The textile dyeing industry consumes a significant amount of high-quality water for processing, which stresses water resources. In recent decades, technologies have been developed to recover water from wastewater. This study describes the high recovery (greater than 92%) of reusable water from an industrial-scale hosiery dye-water recovery facility, consisting of three stages of reverse osmosis and ultrafiltration. The effluent was pre-treated before the membrane process was performed to prevent biofouling. The process performance results in the generation of a consistent water quality that is required for dyeing operations. An average feed flux of 15 l/m(2)h was maintained in the reverse osmosis membrane by regular chemical dosing and cleaning. The integrated membrane process achieved a permeate with a pH of 6.5 and total dissolved solids (TDS) of 160 mg/l, with no other contaminants, which is of sufficient quality for reuse in the cotton hosiery dyeing process.

  10. Bioaugmentation process of secondary effluents for reduction of pathogens, heavy metals and antibiotics.

    PubMed

    Al-Gheethi, A A; Mohamed, R M S R; Efaq, A N; Norli, I; Abd Halid, Abdullah; Amir, H K; Ab Kadir, M O

    2016-10-01

    The study probed into reducing faecal indicators and pathogenic bacteria, heavy metals and β-lactam antibiotics, from four types of secondary effluents by bioaugmentation process, which was conducted with Bacillus subtilis strain at 45 °C. As a result, faecal indicators and pathogenic bacteria were reduced due to the effect of thermal treatment process (45 °C), while the removal of heavy metals and β-lactam antibiotics was performed through the functions of bioaccumulation and biodegradation processes of B. subtilis. Faecal coliform met the guidelines outlined by WHO and US EPA standards after 4 and 16 days, respectively. Salmonella spp. and Staphylococcus aureus were reduced to below the detection limits without renewed growth in the final effluents determined by using a culture-based method. Furthermore, 13.5% and 56.1% of cephalexin had been removed, respectively, from secondary effluents containing 1 g of cephalexin L(-1) (secondary effluent 3), as well as 1 g of cephalexin L(-1) and 10 mg of Ni(2+) L(-1) (secondary effluent 4) after 16 days. The treatment process, eventually, successfully removed 96.6% and 66.3% of Ni(2+) ions from the secondary effluents containing 10 mg of Ni(2+) L(-1) (secondary effluent 2) and E4, respectively. The bioaugmentation process improved the quality of secondary effluents.

  11. Application of Hollow Fiber Forward Osmosis Membranes for Produced and Process Water Volume Reduction: An Osmotic Concentration Process.

    PubMed

    Minier-Matar, Joel; Santos, Ana; Hussain, Altaf; Janson, Arnold; Wang, Rong; Fane, Anthony G; Adham, Samer

    2016-06-07

    Produced and process water (PPW) from oil and gas operations, specifically in Qatar, are disposed of by deep well injection in onshore facilities. Disposing large volumes of PPW may affect deep well formation sustainability highlighting the need for effective PPW management. Forward osmosis (FO) was applied as an "osmotic concentration" process to reduce PPW injection volumes by 50% using brines and seawater as draw solutions (DS). The energy intensive step of restoring the salinity of the DS was eliminated; the diluted DS would be simply discharged to the ocean. Both hollow fiber and flat sheet FO membranes were tested and the former exhibited better flux and rejection; they are the focus of this study. Optimization experiments, conducted using Box-Behnken statistical design, confirmed that temperature and DS concentration had a substantial effect on performance. To validate the concept, a long-term experiment, under optimized conditions, was conducted with PPW as feed and brine from thermal desalination plant as DS which yielded an average flux of 24 L/m(2)h. The results confirmed that low-energy osmotic concentration FO has the potential for full-scale implementation to reduce PPW injection volumes. Pilot testing opportunities are being evaluated to demonstrate the effectiveness of this technology under field conditions.

  12. Biomass waste gasification - Can be the two stage process suitable for tar reduction and power generation?

    SciTech Connect

    Sulc, Jindrich; Stojdl, Jiri; Richter, Miroslav; Popelka, Jan; Svoboda, Karel; Smetana, Jiri; Vacek, Jiri; Skoblja, Siarhei; Buryan, Petr

    2012-04-15

    Highlights: Black-Right-Pointing-Pointer Comparison of one stage (co-current) and two stage gasification of wood pellets. Black-Right-Pointing-Pointer Original arrangement with grate-less reactor and upward moving bed of the pellets. Black-Right-Pointing-Pointer Two stage gasification leads to drastic reduction of tar content in gas. Black-Right-Pointing-Pointer One stage gasification produces gas with higher LHV at lower overall ER. Black-Right-Pointing-Pointer Content of ammonia in gas is lower in two stage moving bed gasification. - Abstract: A pilot scale gasification unit with novel co-current, updraft arrangement in the first stage and counter-current downdraft in the second stage was developed and exploited for studying effects of two stage gasification in comparison with one stage gasification of biomass (wood pellets) on fuel gas composition and attainable gas purity. Significant producer gas parameters (gas composition, heating value, content of tar compounds, content of inorganic gas impurities) were compared for the two stage and the one stage method of the gasification arrangement with only the upward moving bed (co-current updraft). The main novel features of the gasifier conception include grate-less reactor, upward moving bed of biomass particles (e.g. pellets) by means of a screw elevator with changeable rotational speed and gradual expanding diameter of the cylindrical reactor in the part above the upper end of the screw. The gasifier concept and arrangement are considered convenient for thermal power range 100-350 kW{sub th}. The second stage of the gasifier served mainly for tar compounds destruction/reforming by increased temperature (around 950 Degree-Sign C) and for gasification reaction of the fuel gas with char. The second stage used additional combustion of the fuel gas by preheated secondary air for attaining higher temperature and faster gasification of the remaining char from the first stage. The measurements of gas composition and tar

  13. Reduction of azinphos-methyl, chlorpyrifos, esfenvalerate, and methomyl residues in processed apples.

    PubMed

    Zabik, M J; El-Hadidi, M F; Cash, J N; Zabik, M E; Jones, A L

    2000-09-01

    McIntosh, Red Delicious, and Golden Delicious from two years of experimental spray programs using azinphos-methyl, chlorpyrifos, esfenvalerate, and methomyl were processed into frozen apple slices, applesauce, single-strength juice, and juice concentrate. Residue levels were expressed as micrograms per 150 g of apple or the equivalent amount of apple product to calculate the percentage change in these pesticides brought about by processing. Producing single-strength apple juice reduced azinphos-methyl, chlorpyrifos, esfenvalerate, and methomyl residues by 97.6, 100, 97.8, and 78.1%, respectively. Production of applesauce reduced all four compounds by >/=95%. Azinphos-methyl, chlorpyrifos, esfenvalerate, and methomyl residues were reduced in apple slices by 94.1, 85.7, 98.6, and 94.7%, respectively. Processing is shown to be very effective in reducing the levels of these pesticides.

  14. Reduction of acute toxicity and genotoxicity of dye effluent using Fenton-coagulation process.

    PubMed

    Zhang, Jing; Chen, Shuo; Zhang, Ying; Quan, Xie; Zhao, Huimin; Zhang, Yaobin

    2014-06-15

    Dye wastewater exhibits significant ecotoxicity even though its physico-chemical parameters meet the discharge standards. In this work, the acute toxicity and genotoxicity of dye effluent were tested, and the Fenton-coagulation process was carried out to detoxify this dye effluent. The acute toxicity was evaluated according to the mortality rate of zebrafish, and genotoxicity was evaluated by micronucleus (MN) and comet assays. Removal of color and chemical oxygen demand (COD) was also investigated. The results indicated that the dye effluent showed strong acute toxicity and genotoxicity to zebrafish. After 4h of treatment by Fenton-coagulation process, the dye effluent exhibited no significant acute toxicity and genotoxicity to zebrafish. In addition, its COD was less than 50mg/L, which met the discharge standard. It demonstrates that Fenton-coagulation process can comprehensively reduce the acute toxicity and genotoxicity as well as the COD of the dye effluent.

  15. Reduction of iron oxides during the pyrometallurgical processing of red mud

    NASA Astrophysics Data System (ADS)

    Raspopov, N. A.; Korneev, V. P.; Averin, V. V.; Lainer, Yu. A.; Zinoveev, D. V.; Dyubanov, V. G.

    2013-01-01

    The results of experiments on the use of red mud in traditional pyrometallurgical processes and plants are presented. The red muds of the Ural Aluminum Plant (UAZ, Kamensk-Ural'skii) and the Alyum Plant (Tul'chiya) are shown to have similar phase and chemical compositions. The morphology of the iron oxides in red mud samples taken from mud storage is studied by Mössbauer spectroscopy. It is found that the metallic (cast iron) and slag phases that form during the pyrometallurgical processing of red mud by melting with a carbon reducer in the temperature range 1200-1500°C are clearly separated. Cast iron can be used in steelmaking, and the slag can be used for hydrometallurgical processing and extraction of nonferrous metals and for the building industry after correcting its composition.

  16. Uptake of non-transferrin-bound iron by both reductive and nonreductive processes is modulated by intracellular iron.

    PubMed

    Randell, E W; Parkes, J G; Olivieri, N F; Templeton, D M

    1994-06-10

    Non-transferrin-bound iron (NTBI) uptake occurs in a variety of cells by a saturable, specific and temperature-sensitive process. Our previous studies indicated that NTBI uptake by cardiac myocytes and Hep G2 cells was reversibly up-regulated by iron deposition. In the present work we have characterized this up-regulation and examined its mechanism by comparing the uptake of oxidized (Fe3+) and ascorbate-reduced (Fe2+) forms of iron. Iron loading markedly enhanced the uptake of iron both in the presence and absence of ascorbate, but the increment was greater when ascorbate was absent. This up-regulation is partially inhibited by actinomycin D and cycloheximide, indicating a requirement for protein synthesis. Uptake by the iron-loaded cells was less sensitive to thiol-alkylating agents and competing metal ions, but was more sensitive to proteolysis. Iron loading causes an increase in both Km and Vmax for uptake of both Fe2+ and Fe3+, although the values differ, suggesting distinct rate-limiting steps for uptake of Fe2+ and Fe3+. Consistent with this idea, uptake of the two ions showed differential sensitivity to thiol reagents, competing metal ions and monensin. The Fe(2+)-specific chelators bathophenanthroline disulfonate and ferrozine markedly inhibited iron uptake whether ascorbate was present or not, indicating that Fe3+ uptake is dependent on reduction to the ferrous state. This requirement for reduction was independent of the iron status of the cells, demonstrating that the process of up-regulation is not due to the appearance of a new mechanism for translocation of Fe3+ without reduction. Taken together, the evidence favors a model of NTBI transport where an obligate and rate-determining reduction of Fe3+ occurs prior to or during uptake, followed by translocation through an Fe2+ carrier. The distinct translocation mechanisms of uptake in the presence and absence of ascorbate suggest that exogenous Fe2+ does not access the carrier available to the nascent

  17. A new process for volume reduction of radwaste, drying and calcination of crystals

    SciTech Connect

    Krapukhin, V.B.; Kareta, V.I.; Zurin, V.D.; Lavricov, V.A.; Grushevsky, S.E.

    1993-12-31

    The facility COMPLEX-1 designed for carrying out the processes of mass crystallization from solutions, separation of the resulting solid phase from mother liquor, drying of crystals, their calcination and loading the product obtained into containers, is described. The facility is entirely hermetic. It works in vacuum and has an autonomous system of gas purification, excluding the carryover of dust during the thermal treatment of the product obtained. All the technological processes are continuous and carried out in a minimum volume without pumping the products from apparatus to apparatus. The facility is compact and ecologically safer than the familiar analogous facilities. Each unit of the facility may be of special interest for users.

  18. Demonstration of innovative applications of technology for cost reductions to the CT-121 FGD process

    SciTech Connect

    Not Available

    1991-02-15

    The objective of this project is to demonstrate on a commercial scale several innovative applications of cost-reducing technology to the Chiyoda Thoroughbred-121 (CT-121) process. CT-121 is a second generation flue gas desulfurization (FGD) process which is considered by the Electric Power Research Institute (EPRI) and Southern Company Services (SCS) to be one of the most reliable and lowest cost FGD options for high-sulfur coal-fired utility boiler applications. Demonstrations of the innovative design approaches will further reduce the cost and provide a clear advantage to CT121 relative to competing technology.

  19. Demonstration of innovative applicatiions of technology for cost reductions to the CT-121 FGD process

    SciTech Connect

    Not Available

    1991-05-15

    The objective of this project is to demonstrate on a commercial scale several innovative applications of cost-reducing technology to the Chiyoda Thoroughbred-121 (CT-121) process. CT-121 is a second generation flue gas desulfurization (FGD) process which is considered by the Electric Power Research Institute (EPRI) and Southern Company Services (SCS) to be one of the most reliable and lowest cost FGD options for high-sulfur coal-fired utility boiler applications. Demonstrations of the innovative design approaches will further reduce the cost and provide a clear advantage to CT121 relative to competing technology.

  20. Abatement and toxicity reduction of antimicrobials by UV/H2O2 process.

    PubMed

    Urbano, Vanessa Ribeiro; Peres, Marcela Souza; Maniero, Milena Guedes; Guimarães, José Roberto

    2017-05-15

    Antimicrobials are continuously detected in environmental waters and their removal is important to avoid health and microorganisms damage. In this work, the peroxidation assisted by ultraviolet radiation (UV/H2O2) was studied to verify if the process was able to degrade sulfaquinoxaline and ofloxacin antimicrobials and to remove the toxicity and the antimicrobial activity of the solution. This process was effective on degradation of the antimicrobials, despite the antimicrobial activity removal, the toxicity of the solution increased throughout the reaction time.

  1. Integration of the CERCLA and RCRA processes at an industrial facility using Texas risk reduction standards

    SciTech Connect

    Crossley, D.B.; Rogers, W.J.

    1995-12-31

    Industrial facilities in Texas that use, store and/or treat hazardous materials operate pursuant to the conditions of a Resource Conservation and Recovery Act (RCRA) permit and must also ensure compliance with provisions of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) if nominated to the National Priorities List of contaminated sites. While the CERCLA and RCRA programs have differing approaches, their objective is similar, i.e., mitigation of releases or threatened releases of toxic substances that may adversely impact human health or the environment. Recognizing the similarities in regulatory intent, a regulated facility may use Texas-promulgated risk reduction standards to establish risk-based contaminant specific cleanup levels for corrective actions pursuant to RCRA authority. Simultaneously, the facility will be evaluated for risk to human and ecological endpoints pursuant to CERCLA. A Baseline Risk Assessment (BRA) must be conducted to establish site-wide objectives that will be applied to individual solid waste management units ensuring compliance with all substantive requirements of CERCLA. The authors conclude that the parallel, integrated approach to these regulatory requirements will accelerate characterization/remediation of potential waste disposal sites, thereby reducing Environmental Restoration program expenditures.

  2. Portal imaging: Performance improvement in noise reduction by means of wavelet processing.

    PubMed

    González-López, Antonio; Morales-Sánchez, Juan; Larrey-Ruiz, Jorge; Bastida-Jumilla, María-Consuelo; Verdú-Monedero, Rafael

    2016-01-01

    This paper discusses the suitability, in terms of noise reduction, of various methods which can be applied to an image type often used in radiation therapy: the portal image. Among these methods, the analysis focuses on those operating in the wavelet domain. Wavelet-based methods tested on natural images--such as the thresholding of the wavelet coefficients, the minimization of the Stein unbiased risk estimator on a linear expansion of thresholds (SURE-LET), and the Bayes least-squares method using as a prior a Gaussian scale mixture (BLS-GSM method)--are compared with other methods that operate on the image domain--an adaptive Wiener filter and a nonlocal mean filter (NLM). For the assessment of the performance, the peak signal-to-noise ratio (PSNR), the structural similarity index (SSIM), the Pearson correlation coefficient, and the Spearman rank correlation (ρ) coefficient are used. The performance of the wavelet filters and the NLM method are similar, but wavelet filters outperform the Wiener filter in terms of portal image denoising. It is shown how BLS-GSM and NLM filters produce the smoothest image, while keeping soft-tissue and bone contrast. As for the computational cost, filters using a decimated wavelet transform (decimated thresholding and SURE-LET) turn out to be the most efficient, with calculation times around 1 s.

  3. Phyto-crystallization of palladium through reduction process using Cinnamom zeylanicum bark extract.

    PubMed

    Sathishkumar, M; Sneha, K; Kwak, In Seob; Mao, Juan; Tripathy, S J; Yun, Y-S

    2009-11-15

    In this paper we studied the potential of nanocrystalline palladium particle production using Cinnamom zeylanicum bark extract (CBE) as the biomaterial for the first time. We studied the effects of biomaterial dosage, pH and temperature on nanoparticle formation; none of these factors had a major effect on the size and shape of the nanoparticles formed. Transmission electron microscopy (TEM) observations confirmed the synthesis of nano-sized palladium particles. More or less uniformly sized palladium nanoparticles were synthesized with an average size ranging from 15 to 20 nm. It was found that the zeta potential of these formed palladium nanoparticles was negative, and that it increased with an increase in pH. Energy dispersive X-ray (EDX) analysis results confirmed the significant presence of palladium. Of the palladium ions, 60% were reduced to a zero valent form by CBE. Terpenoids are believed to play an important role in palladium nanoparticle biosynthesis through the reduction of palladium ions. Currently, however, the exact mechanism for the synthesis of palladium nanoparticles is unclear. Our protocol for the phyto-synthesis of palladium nanoparticles under moderate pH and room temperature offers a new means to develop environmentally benign nanoparticles.

  4. Initiation process of earthquakes and its implications for seismic hazard reduction strategy.

    PubMed

    Kanamori, H

    1996-04-30

    For the average citizen and the public, "earthquake prediction" means "short-term prediction," a prediction of a specific earthquake on a relatively short time scale. Such prediction must specify the time, place, and magnitude of the earthquake in question with sufficiently high reliability. For this type of prediction, one must rely on some short-term precursors. Examinations of strain changes just before large earthquakes suggest that consistent detection of such precursory strain changes cannot be expected. Other precursory phenomena such as foreshocks and nonseismological anomalies do not occur consistently either. Thus, reliable short-term prediction would be very difficult. Although short-term predictions with large uncertainties could be useful for some areas if their social and economic environments can tolerate false alarms, such predictions would be impractical for most modern industrialized cities. A strategy for effective seismic hazard reduction is to take full advantage of the recent technical advancements in seismology, computers, and communication. In highly industrialized communities, rapid earthquake information is critically important for emergency services agencies, utilities, communications, financial companies, and media to make quick reports and damage estimates and to determine where emergency response is most needed. Long-term forecast, or prognosis, of earthquakes is important for development of realistic building codes, retrofitting existing structures, and land-use planning, but the distinction between short-term and long-term predictions needs to be clearly communicated to the public to avoid misunderstanding.

  5. A Simple Reduction Process for the Normal Vibrational Modes Occurring in Linear Molecules

    ERIC Educational Resources Information Center

    McInerny, William

    2005-01-01

    The students in molecular spectroscopy courses are often required to determine the permitted normal vibrations for linear molecules that belong to particular groups. The reducible group representations generated by the use of Cartesian coordinates can be reduced by the use of a simple algebraic process applied to the group representations. The…

  6. Direct Electrolytic Reduction of Solid Ta2O5 to Ta with SOM Process

    NASA Astrophysics Data System (ADS)

    Chen, Chaoyi; Yang, Xiaqiong; Li, Junqi; Lu, Xionggang; Yang, Shufeng

    2016-06-01

    A process that uses the solid-oxide-oxygen-ion conducting membrane has been investigated to produce tantalum directly from solid Ta2O5 in molten CaCl2 or a molten mixture of 55.5MgF2-44.5CaF2 (in wt pct). The sintered porous Ta2O5 pellet was employed as the cathode, while the liquid copper alloy, saturated with graphite powder and encased in a one-end-closed yttria-stabilized-zirconia (YSZ) tube, acted as the anode. The electrolysis potential in this method is higher than that of the Fray-Farthing-Chen Cambridge process because the YSZ membrane tube blocks the melts to electrolyze, and only Ta2O5 is will be electrolyzed. The microstructures of reduced pellets and a cyclic voltammogram of solid Ta2O5 in molten CaCl2 were analyzed. In addition, the influence of particle size and porosity of the cathode pellets on metal-oxide-electrolyte, three-phase interlines was also discussed. The results demonstrate that the sintering temperature of cathode pellets and electrolytic temperature play important roles in the electrochemical process. Furthermore, this process can be used to produce Ta metal efficiently without the expensive cost of pre-electrolysis and generation of harmful by-products.

  7. CRITICAL EVALUATION OF THE EFFECTIVENESS OF SEWAGE SLUDGE DISINFECTION AND VECTOR ATTRACTION REDUCTION PROCESSES

    EPA Science Inventory

    What is the current state of management practices for biosolids production and application, and how can those be made more effective? How effective are Class B disinfection and vector attraction processes, and public access and harvesting restrictions at reducing the public's exp...

  8. UV/chlorine process for ammonia removal and disinfection by-product reduction: comparison with chlorination.

    PubMed

    Zhang, Xinran; Li, Weiguang; Blatchley, Ernest R; Wang, Xiaoju; Ren, Pengfei

    2015-01-01

    The combined application of UV irradiation at 254 nm and chlorination (UV/chlorine process) was investigated for ammonia removal in water treatment. The UV/chlorine process led to higher ammonia removal with less chlorine demand, as compared to breakpoint chlorination. Chlorination of NH₃ led to NH₂Cl formation in the first step. The photolysis of NH₂Cl and radical- mediated oxidation of ammonia appeared to represent the main pathways for ammonia removal. The trivalent nitrogen of ammonia was oxidized, presumably by reactions with aminyl radicals and chlorine radicals. Measured products included NO₃⁻and NO₂⁻; it is likely that N₂ and N₂O were also generated. In addition, UV irradiation appeared to have altered the reactivity of NOM toward free chlorine. The UV/chlorine process had lower chlorine demand, less C-DBPs (THMs and HAAs), but more HANs than chlorination. These results indicate that the UV/chlorine process could represent an alternative to conventional breakpoint chlorination for ammonia-containing water, with several advantages in terms of simplicity, short reaction time, and reduced chemical dosage.

  9. Effect of high pressure processing on reduction of Listeria monocytogenes in packaged Queso Fresco

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of high hydrostatic pressure processing (HPP) on the survival of a five-strain rifampicin-resistant cocktail of Listeria monocytogenes in Queso Fresco (QF) was evaluated as a post-packaging intervention. QF was made using pasteurized, homogenized milk, was starter-free and was not pressed...

  10. ECO LOGIC INTERNATIONAL GAS-PHASE CHEMICAL REDUCTION PROCESS - THE REACTOR SYSTEM - APPLICATIONS ANALYSIS REPORT

    EPA Science Inventory

    The ELI Eco Logic International Inc. (Eco Logic) process thermally separates organics, then chemically reduces them in a hydrogen atmosphere, converting them to a reformed gas that consists of light hydrocarbons and water. A scrubber treats the reformed gas to remove hydrogen chl...

  11. Phosphorus removal performance and population structure of phosphorus-accumulating organisms in HA-A/A-MCO sludge reduction process.

    PubMed

    Zuo, Ning; He, Jinchao; Ma, Xiqin; Peng, Yongqin; Li, Xia

    2016-09-02

    We developed a new sludge reduction HA-A/A-MCO (Hydrolysis-Acidogenosis-Anaerobic/Anoxic -Multistep Continuous Oxic tank) process, which has improved phosphate (P) and nitrogen (N) removal. Its biological treatment unit uses an A(2)/O P & N removal process with hydrolysis acidification, multistep continuous aeration, and continuous flow, coupled with sidestream P removal by draining out anaerobic P-bearing wastewater. The process has advanced synchronization of P and N removal and sludge reduction. The improved performance is closely associated with the population structure of P-accumulating organisms (PAOs). This study investigated the relationship between P removal performance and the population structure of PAOs. The results show that the average effluent P content of HA-A/A-MCO process was only 0.44 mg/L, when the influent P concentration was 8∼12 mg/L. The effluent met the A standard set by GB18918-2002. PAOs were able to effectively release 1 mg of P and absorb 2.8 mg of P. The system removed P by draining out anaerobic P-rich wastewater, as P had been reduced in the aerobic absorption process. This reduced the need for excess P uptake ability of the PAOs. The bacterial pure culture method was applied to isolate 5 PAOs with typical P absorption and removel features. 16SrDNA amplification and sequence analysis revealed that Acinetobacter sp. and Lampropedia sp played dominant roles in anaerobic P-releasing process. Moreover, Devosia sp. and Bdellovibrio sp were the primary strains in the aerobic tank, and, they were the major stains for P absorption. Uncultured Bacterium and other uncultured strains were detected in the anoxic tank.

  12. Modeling of a CeO2 thermochemistry reduction process for hydrogen production by solar concentrated energy

    NASA Astrophysics Data System (ADS)

    Valle-Hernández, Julio; Romero-Paredes, Hernando; Arancibia-Bulnes, Camilo A.; Villafan-Vidales, Heidi I.; Espinosa-Paredes, Gilberto

    2016-05-01

    In this paper the simulation of the thermal reduction for hydrogen production through the decomposition of cerium oxide is presented. The thermochemical cycle for hydrogen production consists of the endothermic reduction of CeO2 at high temperature, where concentrated solar energy is used as a source of heat; and of the subsequent steam hydrolysis of the resulting cerium oxide to produce hydrogen. For the thermochemical process, a solar reactor prototype is proposed; consisting of a cubic receptacle made of graphite fiber thermally insulated. Inside the reactor a pyramidal arrangement with nine tungsten pipes is housed. The pyramidal arrangement is made respect to the focal point where the reflected energy is concentrated. The solar energy is concentrated through the solar furnace of high radiative flux. The endothermic step is the reduction of the cerium oxide to lower-valence cerium oxide, at very high temperature. The exothermic step is the hydrolysis of the cerium oxide (III) to form H2 and the corresponding initial cerium oxide made at lower temperature inside the solar reactor. For the modeling, three sections of the pipe where the reaction occurs were considered; the carrier gas inlet, the porous medium and the reaction products outlet. The mathematical model describes the fluid mechanics; mass and energy transfer occurring therein inside the tungsten pipe. Thermochemical process model was simulated in CFD. The results show a temperature distribution in the solar reaction pipe and allow obtaining the fluid dynamics and the heat transfer within the pipe. This work is part of the project "Solar Fuels and Industrial Processes" from the Mexican Center for Innovation in Solar Energy (CEMIE-Sol).

  13. Experimental and modeling study of the effect of CH(4) and pulverized coal on selective non-catalytic reduction process.

    PubMed

    Zhang, Yanwen; Cai, Ningsheng; Yang, Jingbiao; Xu, Bo

    2008-10-01

    The reduction of nitric oxide using ammonia combined with methane and pulverized coal additives has been studied in a drop tube furnace reactor. Simulated flue gas with 1000 ppm NO(x) and 3.4% excess oxygen was generated by cylinder gas. Experiments were performed in the temperature range of 700-1200 degrees C to investigate the effects of additives on the DeNO(x) performance. Subsequently, a kinetic mechanism was modified and validated based on experimental results, and a computational kinetic modeling with CHEMKIN was conducted to analyze the secondary pollutants. For both methane and pulverized coal additives, the temperature window is shifted towards lower temperatures. The appropriate reaction temperature is shifted to about 900 and 800 degrees C, respectively with 1000 ppm methane and 0.051 g min(-1) pulverized lignite coal. The addition of methane and pulverized coal widens the temperature window towards lower temperature suggesting a low temperature application of the process. Furthermore, selective non-catalytic reduction (SNCR) reaction rate is accelerated evidently with additives and the residence time to complete the reaction is shortened distinctly. NO(x) reduction efficiency with 80% is achieved in about 0.3s without additive at 1000 degrees C. However, it is achieved in only about 0.2s with 100 ppm methane as additive, and only 0.07 and 0.05s are needed respectively for the cases of 500 and 1000 ppm methane. The modified kinetic modeling agrees well with the experimental results and reveals additional information about the process. Investigation on the byproducts where NO(2) and N(2)O were analyzed by modeling and the others were investigated by experimental means indicates that emissions would not increase with methane and pulverized coal additions in SNCR process and the efficacious temperature range of SNCR reaction is widened approximately with 100 degrees C.

  14. Toxicity reduction and biodegradability enhancement of cork processing wastewaters by ozonation.

    PubMed

    Gomes, A C; Silva, L; Simões, R; Canto, N; Albuquerque, A

    2013-01-01

    Biodegradability enhancement and detoxification of cork boiling wastewater (CBW) are required for the successful implementation of biological treatment options. We studied the possibility of achieving these goals through ozonation pre-treatment by experimenting on the effect of ozone dose and pH. The CBW used had a pH of 5.81, a chemical oxygen demand (COD) of 1,865 mg L(-1), a biochemical oxygen demand (BOD5) of 498 mg L(-1) and total phenol (TP) and tannin compounds concentrations of 523 and 399 mg L(-1), respectively. The ozone doses ranged from 0.27 to 2.63 for the O3(applied)/COD0 ratios with samples at natural pH and set to 3.33 and 9.96. Ozonation allowed the BOD20/COD ratio (biodegradability index) to increase from 0.37 to 0.63 and a toxicity reduction from 3.08 to 1.24 TU (Microtox). The corresponding removals obtained were 15.2-62.0%, 38.4-83.2% and 56.7-92.1% for COD, TP and colour, respectively. The best outcome of ozonation pre-treatment requires O3(applied)/COD0 ratios over 1.5 and an acid pH. The increase of TP removals with ozone dose at acid pH led to biodegradability enhancement and CBW detoxification. However, for similar conditions the highest COD removals were obtained at alkaline pH due to the hydroxyl radicals' high oxidation ability but lack of selectivity.

  15. The process of the reduction of azo dyes used in dyeing textiles on the basis of infrared spectroscopy analysis

    NASA Astrophysics Data System (ADS)

    Pielesz, A.

    1999-11-01

    Nowadays the world observes a widespread campaign against the use in yarn of dangerous, carcinogenic amines which penetrate human organisms. Their source in organisms is the process of biological reduction of azo dyes which are used in dyeing yarn. The current obligatory methods of aromatic amine identification are the widely understood chromatographic methods. In this work, the identification of amines through the fourier transform infrared spectroscopy has been suggested. The results of the experiments have allowed the use of the same method in aromatic amine identification.

  16. Numerical simulation of casting process to assist in defects reduction in complex steel tidal power component

    NASA Astrophysics Data System (ADS)

    Guo, E. J.; Zhao, S. C.; Wang, L. P.; Wu, T.; Xin, B. P.; Tan, J. J.; Jia, H. L.

    2016-03-01

    In order to reduce defects and improve casting quality, ProCAST software is performed to study the solidification process of discharge bowl. Simulated results of original casting process show that the hot tearing is serious at the intersection of blades and outer or inner rings. The shrinkage porosity appears at the bottom of discharge bowl and the transition area of wall thickness. Based on the formation mechanisms of the defects, the structure of chills attached on the outer surface of discharge bowl casting is optimized. The thickness of chills ranges from 25mm to 35mm. The positions of chills corresponded to the outer surface of the T-shaped parts. Compared to the original casting design (without chills), the hot tearing and shrinkage porosity of the discharge bowl are greatly improved with addition of chills.

  17. Comparison between ozonation and the OSA process: analysis of excess sludge reduction and biomass activity in two different pilot plants.

    PubMed

    Torregrossa, Michele; Di Bella, Gaetano; Di Trapani, Daniele

    2012-01-01

    The excess biomass produced during biological treatment of municipal wastewater represents a major issue worldwide, as its disposal implies environmental, economic and social impacts. Therefore, there has been a growing interest in developing technologies to reduce sludge production. The main proposed strategies can be categorized according to the place inside the wastewater treatment plant (WWTP) where the reduction takes place. In particular, sludge minimization can be achieved in the wastewater line as well as in the sludge line. This paper presents the results of two pilot scale systems, to evaluate their feasibility for sludge reduction and to understand their effect on biomass activity: (1) a pilot plant with an ozone contactor in the return activated sludge (RAS) stream for the exposition of sludge to a low ozone dosage; and (2) an oxic-settling-anaerobic (OSA) process with high retention time in the anaerobic sludge holding tank have been studied. The results showed that both technologies enabled significant excess sludge reduction but produced a slight decrease of biomass respiratory activity.

  18. Model reduction for the dynamics and control of large structural systems via neutral network processing direct numerical optimization

    NASA Technical Reports Server (NTRS)

    Becus, Georges A.; Chan, Alistair K.

    1993-01-01

    Three neural network processing approaches in a direct numerical optimization model reduction scheme are proposed and investigated. Large structural systems, such as large space structures, offer new challenges to both structural dynamicists and control engineers. One such challenge is that of dimensionality. Indeed these distributed parameter systems can be modeled either by infinite dimensional mathematical models (typically partial differential equations) or by high dimensional discrete models (typically finite element models) often exhibiting thousands of vibrational modes usually closely spaced and with little, if any, damping. Clearly, some form of model reduction is in order, especially for the control engineer who can actively control but a few of the modes using system identification based on a limited number of sensors. Inasmuch as the amount of 'control spillover' (in which the control inputs excite the neglected dynamics) and/or 'observation spillover' (where neglected dynamics affect system identification) is to a large extent determined by the choice of particular reduced model (RM), the way in which this model reduction is carried out is often critical.

  19. Engineering Test Report: Paint Waste Reduction Fluidized Bed Process Demonstration at Letterkenny Army Depot Chambersburg, Pennsylvania

    DTIC Science & Technology

    1991-07-01

    dimensions to determine the weight of media, The FBM carried out into the cyclone was ignored in this calculation. Furthermore, the cadmium accountability is...thus avoiding thermal- chemical damage to the product being cleaned, I The molten bath chemistry is selected for a given application and consists of a...commonly used solvent, is especially volatile (boiling point 40 OC or 104 OF ). The chemical paint stripping process and the solvent procaess both generate

  20. Forest fire effects on transpiration: process modeling of sapwood area reduction

    NASA Astrophysics Data System (ADS)

    Michaletz, Sean; Johnson, Edward

    2010-05-01

    Transpiration is a hydrological process that is strongly affected by forest fires. In crown fires, canopy fine fuels (foliage, buds, and small branches) combust, which kills individual trees and stops transpiration of the entire stand. In surface fires (intensities ≤ 2500 kW m-1), however, effects on transpiration are less predictable becuase heat transfer from the passing fireline can injure or kill fine roots, leaves, and sapwood; post-fire transpiration of forest stands is thus governed by fire effects on individual tree water budgets. Here, we consider fire effects on cross-sectional sapwood area. A two-dimensional model of transient bole heating is used to estimate radial isotherms for a range of fireline intensities typical of surface fires. Isotherms are then used to drive three processes by which heat may reduce sapwood area: 1) necrosis of living cells in contact with xylem conduits, which prevents repair of natural embolism; 2) relaxation of viscoelastic conduit wall polymers (cellulose, hemicelloluse, and lignin), which reduces cross-sectional conduit area; and 3) boiling of metastable water under tension, which causes conduit embolism. Results show that these processes operate on different time scales, suggesting that fire effects on transpiration vary with time since fire. The model can be linked with a three-dimensional physical fire spread model to predict size-dependent effects on individual trees, which can be used to estimate scaling of individual tree and stand-level transpiration.

  1. Model reduction and physical understanding of slowly oscillating processes : the circadian cycle.

    SciTech Connect

    Goussis, Dimitris A.; Najm, Habib N.

    2006-01-01

    A differential system that models the circadian rhythm in Drosophila is analyzed with the computational singular perturbation (CSP) algorithm. Reduced nonstiff models of prespecified accuracy are constructed, the form and size of which are time-dependent. When compared with conventional asymptotic analysis, CSP exhibits superior performance in constructing reduced models, since it can algorithmically identify and apply all the required order of magnitude estimates and algebraic manipulations. A similar performance is demonstrated by CSP in generating data that allow for the acquisition of physical understanding. It is shown that the processes driving the circadian cycle are (i) mRNA translation into monomer protein, and monomer protein destruction by phosphorylation and degradation (along the largest portion of the cycle); and (ii) mRNA synthesis (along a short portion of the cycle). These are slow processes. Their action in driving the cycle is allowed by the equilibration of the fastest processes; (1) the monomer dimerization with the dimer dissociation (along the largest portion of the cycle); and (2) the net production of monomer+dimmer proteins with that of mRNA (along the short portion of the cycle). Additional results (regarding the time scales of the established equilibria, their origin, the rate limiting steps, the couplings among the variables, etc.) highlight the utility of CSP for automated identification of the important underlying dynamical features, otherwise accessible only for simple systems whose various suitable simplifications can easily be recognized.

  2. Flotation process for removal of precipitates from electrochemical chromate reduction unit

    DOEpatents

    DeMonbrun, James R.; Schmitt, Charles R.; Williams, Everett H.

    1976-01-01

    This invention is an improved form of a conventional electrochemical process for removing hexavalent chromium or other metal-ion contaminants from cooling-tower blowdown water. In the conventional process, the contaminant is reduced and precipitated at an iron anode, thus forming a mixed precipitate of iron and chromium hydroxides, while hydrogen being evolved copiously at a cathode is vented from the electrochemical cell. In the conventional process, subsequent separation of the fine precipitate has proved to be difficult and inefficient. In accordance with this invention, the electrochemical operation is conducted in a novel manner permitting a much more efficient and less expensive precipitate-recovery operation. That is, the electrochemical operation is conducted under an evolved-hydrogen partial pressure exceeding atmospheric pressure. As a result, most of the evolved hydrogen is entrained as bubbles in the blowdown in the cell. The resulting hydrogen-rich blowdown is introduced to a vented chamber, where the entrained hydrogen combines with the precipitate to form a froth which can be separated by conventional techniques. In addition to the hydrogen, two materials present in most blowdown act as flotation promoters for the precipitate. These are (1) air, with which the blowdown water becomes saturated in the course of normal cooling-tower operation, and (2) surfactants which commonly are added to cooling-tower recirculating-water systems to inhibit the growth of certain organisms or prevent the deposition of insoluble particulates.

  3. Mass transfer characteristics in structured packing for CO{sub 2} emission reduction processes

    SciTech Connect

    van Loo, S.; van Elk, E.P.; Raynal, L.; Versteeg, G.F.

    2007-05-15

    Acid gas treating and CO{sub 2} capture from flue gas by absorption have gained wide importance over the past few decades. With the implementation of more stringent environmental regulations and the awareness of the greenhouse effect, the need for efficient removal of acid gases such as CO{sub 2} (carbon dioxide) has increased significantly. Therefore, additional effort for research in this field is inevitable. For flue gas processes the ratio of absorption solvent to gas throughput is very different compared to acid gas treating processes owing to the atmospheric pressures and the dilution effect of combustion air. Moreover, in flue gas applications pressure drop is a very important process parameter. Packing types are required that allow for low pressure drop in combination with high interfacial areas at low liquid loading per square meter. An extended absorption model is required to determine the conditions at which the interfacial area can be measured without detailed knowledge of the values of the liquid-side mass transfer coefficient, k{sub 1}, beforehand.

  4. Data Reduction Processes Using FPGA for MicroBooNE Liquid Argon Time Projection Chamber

    SciTech Connect

    Wu, Jinyuan

    2010-05-26

    MicroBooNE is a liquid Argon time projection chamber to be built at Fermilab for an accelerator-based neutrino physics experiment and as part of the R&D strategy for a large liquid argon detector at DUSEL. The waveforms of the {approx}9000 sense wires in the chamber are continuously digitized at 2 M samples/s - which results in a large volume of data coming off the TPC. We have developed a lossless data reduction scheme based on Huffman Coding and have tested the scheme on cosmic ray data taken from a small liquid Argon time projection chamber, the BO detector. For sense wire waveforms produced by cosmic ray tracks, the Huffman Coding scheme compresses the data by a factor of approximately 10. The compressed data can be fully recovered back to the original data since the compression is lossless. In addition to accelerator neutrino data, which comes with small duty cycle in sync with the accelerator beam spill, continuous digitized waveforms are to be temporarily stored in the MicroBooNE data-acquisition system for about an hour, long enough for an external alert from possible supernova events. Another scheme, Dynamic Decimation, has been developed to compress further the potential supernova data so that the storage can be implemented within a reasonable budget. In the Dynamic Decimation scheme, data are sampled at the full sampling rate in the regions-of-interest (ROI) containing waveforms of track-hits and are decimated down to lower sampling rate outside the ROI. Note that unlike in typical zerosuppression schemes, in Dynamic Decimation, the data in the pedestal region are not thrown away but kept at a lower sampling rate. An additional factor of 10 compression ratio is achieved using the Dynamic Decimation scheme on the BO detector data, making a total compression rate of approximate 100 when the Dynamic Decimation and the Huffman Coding functional blocks are cascaded. Both of the blocks are compiled in low-cost FPGA and their silicon resource usages are low.

  5. Biomass waste gasification - can be the two stage process suitable for tar reduction and power generation?

    PubMed

    Sulc, Jindřich; Stojdl, Jiří; Richter, Miroslav; Popelka, Jan; Svoboda, Karel; Smetana, Jiří; Vacek, Jiří; Skoblja, Siarhei; Buryan, Petr

    2012-04-01

    A pilot scale gasification unit with novel co-current, updraft arrangement in the first stage and counter-current downdraft in the second stage was developed and exploited for studying effects of two stage gasification in comparison with one stage gasification of biomass (wood pellets) on fuel gas composition and attainable gas purity. Significant producer gas parameters (gas composition, heating value, content of tar compounds, content of inorganic gas impurities) were compared for the two stage and the one stage method of the gasification arrangement with only the upward moving bed (co-current updraft). The main novel features of the gasifier conception include grate-less reactor, upward moving bed of biomass particles (e.g. pellets) by means of a screw elevator with changeable rotational speed and gradual expanding diameter of the cylindrical reactor in the part above the upper end of the screw. The gasifier concept and arrangement are considered convenient for thermal power range 100-350 kW(th). The second stage of the gasifier served mainly for tar compounds destruction/reforming by increased temperature (around 950°C) and for gasification reaction of the fuel gas with char. The second stage used additional combustion of the fuel gas by preheated secondary air for attaining higher temperature and faster gasification of the remaining char from the first stage. The measurements of gas composition and tar compound contents confirmed superiority of the two stage gasification system, drastic decrease of aromatic compounds with two and higher number of benzene rings by 1-2 orders. On the other hand the two stage gasification (with overall ER=0.71) led to substantial reduction of gas heating value (LHV=3.15 MJ/Nm(3)), elevation of gas volume and increase of nitrogen content in fuel gas. The increased temperature (>950°C) at the entrance to the char bed caused also substantial decrease of ammonia content in fuel gas. The char with higher content of ash leaving the

  6. ORGANIC-CONTAMINANT DESTRUCTION UNIT ECO LOGIC PROCESS GAS PHASE CHEMICAL REDUCTION

    SciTech Connect

    Unknown

    1998-06-17

    This report describes the Eco Logic Process and discusses the procedures and results of a pilot-scale treatability study on explosives in shell casings. The study was conducted as part of a contract which was awarded to Science Applications International Corporation (SAIC) and Eco Logic by the Department of Energy's Federal Energy Technology Center (FETC) in Morgantown, West Virginia to conduct treatability studies on complex hazardous wastes, energetic and low level mixed wastes. The U.S. Army currently decontaminates spent shell casings using a bailout or high pressure wash process that removes a large amount of the propellant from the casing but not enough to allow recycle of the entire casing intact; the U.S. Army currently projects the use of a metal parts furnace to completely decontaminate the shell casings. Use of the Eco Logic Process to decontaminate the shell casings would allow the shell casing to be reused intact. In addition to explosives commonly used by the Army such as TNT and Composition B, ARDEC personnel also were interested in the decontamination of shell casings with a residual of the propellant Yellow D which is a common energetic in artillery shell casings used by the Navy. A series of treatability tests on neat samples of explosive as well as shell casings containing each explosive were performed between June 9 and June 20, 1997 at the US Army's Edgewood Research Development, Engineering Center (ERDEC) toxic test chamber facility located at Aberdeen Proving Ground, Maryland., including a 2 gram neat sample of TNT and lO gram samples of TNT, composition B and Yellow D to determine optimal treatment conditions for each explosive followed by two tests on washed shell casings containing trace amounts of TNT and a total of six tests, two each on shell casings lined with 10 grams of TNT, composition B and Yellow D.

  7. Error reduction during visual processing by the retina—a paradigm for sensor design

    NASA Astrophysics Data System (ADS)

    Liess, Martin; Nippert, Klaus

    2006-04-01

    We use a general second-order mathematical description of sensing, sensory information acquisition and pre-processing to treat biological vision in analogy to a technical sensor. Using very early visual processing by the retina, i.e. the retinal receptive fields, we compare the structure of interconnection of photoreceptors, bipolar and ganglion cells that evolved in vertebrates with other structures of interconnections that would serve the same purpose of generating an image of contrasts and supplying it to the brain. We are able to show that the ladder-type structure of the vertebrate retina approaches ideal behaviour (with respect to high linearity and low error sensitivity) and is the structure most tolerant to imperfection of its constituent elements, the different nerve cells. Since the model presented is very general, it can be applied to other sensory systems as well. The application of the sensory structure of the retina (which, from the biological modelling point of view, derives in a straightforward way from known facts about retina physiology) is useful if applied to sensor design. In particular it shows how nonlinearities, error- and cross sensitivities of the entire sensor system can be reduced by the structure among its elements.

  8. Performance Evaluation of Staged Bosch Process for CO2 Reduction to Produce Life Support Consumables

    NASA Technical Reports Server (NTRS)

    Vilekar, Saurabh A.; Hawley, Kyle; Junaedi, Christian; Walsh, Dennis; Roychoudhury, Subir; Abney. Morgan B.; Mansell, James M.

    2012-01-01

    Utilizing carbon dioxide to produce water and hence oxygen is critical for sustained manned missions in space, and to support both NASA's cabin Atmosphere Revitalization System (ARS) and In-Situ Resource Utilization (ISRU) concepts. For long term missions beyond low Earth orbit, where resupply is significantly more difficult and costly, open loop ARS, like Sabatier, consume inputs such as hydrogen. The Bosch process, on the other hand, has the potential to achieve complete loop closure and is hence a preferred choice. However, current single stage Bosch reactor designs suffer from a large recycle penalty due to slow reaction rates and the inherent limitation in approaching thermodynamic equilibrium. Developmental efforts are seeking to improve upon the efficiency (hence reducing the recycle penalty) of current single stage Bosch reactors which employ traditional steel wool catalysts. Precision Combustion, Inc. (PCI), with support from NASA, has investigated the potential for utilizing catalysts supported over short-contact time Microlith substrates for the Bosch reaction to achieve faster reaction rates, higher conversions, and a reduced recycle flows. Proof-of-concept testing was accomplished for a staged Bosch process by splitting the chemistry in two separate reactors, first being the reverse water-gas-shift (RWGS) and the second being the carbon formation reactor (CFR) via hydrogenation and/or Boudouard. This paper presents the results from this feasibility study at various operating conditions. Additionally, results from two 70 hour durability tests for the RWGS reactor are discussed.

  9. A new process for NOx reduction in combustion systems for the generation of energy from waste.

    PubMed

    Gohlke, Oliver; Weber, Toralf; Seguin, Philippe; Laborel, Yann

    2010-07-01

    In the EU, emissions from energy from waste plants are largely reduced by applying the Waste Incineration Directive with its limit of 200 mg/m3(s) for NO(x) emissions. The need for further improvement is reflected by new German legislation effective as of 27 January 2009, requiring 100 mg/m3(s). Other countries are expected to follow this example due to the national emission ceilings of the Gothenburg protocol and the concluding EU directive 2001/81/EC. On the other hand, an increase in energy efficiency will be encouraged by the EU Waste Framework Directive. This is why there is a need for new technologies that make it possible to reconcile both requirements: reduced emissions and increased energy efficiency. A new process combining the internal recirculation of flue gas with ammonia or urea injection in order to achieve less then 80 mg/m3(s) of NO(x) is described. Important additional features of the process are an R1 efficiency above the required 0.65 of the EU Waste Framework Directive even with standard steam parameters of 40 bar/380 degrees C as well as low ammonia slip in the flue gas at the boiler outlet of below 10 mg/m3(s).

  10. Modeling to Improve the Risk Reduction Process for Command File Errors

    NASA Technical Reports Server (NTRS)

    Meshkat, Leila; Bryant, Larry; Waggoner, Bruce

    2013-01-01

    The Jet Propulsion Laboratory has learned that even innocuous errors in the spacecraft command process can have significantly detrimental effects on a space mission. Consequently, such Command File Errors (CFE), regardless of their effect on the spacecraft, are treated as significant events for which a root cause is identified and corrected. A CFE during space mission operations is often the symptom of imbalance or inadequacy within the system that encompasses the hardware and software used for command generation as well as the human experts and processes involved in this endeavor. As we move into an era of increased collaboration with other NASA centers and commercial partners, these systems become more and more complex. Consequently, the ability to thoroughly model and analyze CFEs formally in order to reduce the risk they pose is increasingly important. In this paper, we summarize the results of applying modeling techniques previously developed to the DAWN flight project. The original models were built with the input of subject matter experts from several flight projects. We have now customized these models to address specific questions for the DAWN flight project and formulating use cases to address their unique mission needs. The goal of this effort is to enhance the project's ability to meet commanding reliability requirements for operations and to assist them in managing their Command File Errors.

  11. Carbene-catalysed reductive coupling of nitrobenzyl bromides and activated ketones or imines via single-electron-transfer process

    PubMed Central

    Li, Bao-Sheng; Wang, Yuhuang; Proctor, Rupert S. J.; Zhang, Yuexia; Webster, Richard D.; Yang, Song; Song, Baoan; Chi, Yonggui Robin

    2016-01-01

    Benzyl bromides and related molecules are among the most common substrates in organic synthesis. They are typically used as electrophiles in nucleophilic substitution reactions. These molecules can also be activated via single-electron-transfer (SET) process for radical reactions. Representative recent progress includes α-carbon benzylation of ketones and aldehydes via photoredox catalysis. Here we disclose the generation of (nitro)benzyl radicals via N-heterocyclic carbene (NHC) catalysis under reductive conditions. The radical intermediates generated via NHC catalysis undergo formal 1,2-addition with ketones to eventually afford tertiary alcohol products. The overall process constitutes a formal polarity-inversion of benzyl bromide, allowing a direct coupling of two initially electrophilic carbons. Our study provides a new carbene-catalysed reaction mode that should enable unconventional transformation of (nitro)benzyl bromides under mild organocatalytic conditions. PMID:27671606

  12. Influence of punch face angle and reduction on flow mode in backward and combined radial backward extrusion process

    NASA Astrophysics Data System (ADS)

    Noh, Jeong-hoon; Hwang, Beong Bok; Lee, Ho Yong

    2015-11-01

    This paper is concerned with the analysis on the flow mode which determines lubrication limit such as stiction onto or sliding over punch face. The main goal of this study is to examine the influence of geometrical parameters such as punch face angle, reduction in area, and the gap height in radial direction in backward and combined radial-backward extrusion process on the flow mode and surface stresses such as sliding velocity, sliding distance and surface expansion. Annealed steel 17Cr3 was selected as a model material, a rigid-plastic material, for simulation, which was conducted using a commercially available FEA tool, Deform 2-D, programmed in a rigid plasticity theory. Change of flow mode during deformation was also investigated to find under which conditions of process parameter adopted the flow mode changes from stiction to transition or transition to sliding. In this paper, sliding velocities were quantitatively analyzed to determine the flow mode.

  13. Carbene-catalysed reductive coupling of nitrobenzyl bromides and activated ketones or imines via single-electron-transfer process

    NASA Astrophysics Data System (ADS)

    Li, Bao-Sheng; Wang, Yuhuang; Proctor, Rupert S. J.; Zhang, Yuexia; Webster, Richard D.; Yang, Song; Song, Baoan; Chi, Yonggui Robin

    2016-09-01

    Benzyl bromides and related molecules are among the most common substrates in organic synthesis. They are typically used as electrophiles in nucleophilic substitution reactions. These molecules can also be activated via single-electron-transfer (SET) process for radical reactions. Representative recent progress includes α-carbon benzylation of ketones and aldehydes via photoredox catalysis. Here we disclose the generation of (nitro)benzyl radicals via N-heterocyclic carbene (NHC) catalysis under reductive conditions. The radical intermediates generated via NHC catalysis undergo formal 1,2-addition with ketones to eventually afford tertiary alcohol products. The overall process constitutes a formal polarity-inversion of benzyl bromide, allowing a direct coupling of two initially electrophilic carbons. Our study provides a new carbene-catalysed reaction mode that should enable unconventional transformation of (nitro)benzyl bromides under mild organocatalytic conditions.

  14. Reduction of VOC emissions by a membrane-based gas absorption process.

    PubMed

    Li, Rui; Xu, Jun; Wang, Lianjun; Li, Jiansheng; Sun, Xiuyun

    2009-01-01

    A membrane-based gas absorption (MGA) process was evaluated for the removal of volatile organic compounds (VOCs) based on C6H6/N2 mixture. The absorption of C6H6 from a C6H6/N2 mixture was investigated using a hydrophobic polypropylene hollow fiber membrane contactor and the aqueous solution of N-formyl morpholine (NFM) as absorbent. The effects of various factors on the overall mass transfer coefficient was investigated. The experimental results showed that the removal efficiency of C6H6 could reach 99.5% in present studied system. A mathematical model based on resistance-in-series concept was presented to predict the value of overall mass transfer coefficient. The average error between the predicted and experimental values is 7.9%. In addition, conventional packed columns for VOCs removal was also evaluated for comparison.

  15. PROCESS FOR RECOVERY OF URANIUM AND VANADIUM FROM CARBONATE SOLUTIONS BY REDUCTION-PRECIPITATION

    DOEpatents

    Ellis, D.A.; Lindblom, R.O.

    1957-09-24

    A process employing carbonate leaching of ores and an advantageous methcd of recovering the uranium and vanadium from the leach solution is described. The uranium and vanadium can be precipitated from carbonate leach solutions by reaction with sodium amalgam leaving the leach solution in such a condition that it is economical to replenish for recycling. Such a carbonate leach solution is treated with a dilute sodium amalgam having a sodium concentration within a range of about 0.01 to 0.5% of sodium. Efficiency of the treatment is dependent on at least three additional factors, intimacy of contact of the amalgam with the leach solution, rate of addition of the amalgam and exclusion of oxygen (air).

  16. Effect of high-pressure processing on reduction of Listeria monocytogenes in packaged Queso Fresco.

    PubMed

    Tomasula, P M; Renye, J A; Van Hekken, D L; Tunick, M H; Kwoczak, R; Toht, M; Leggett, L N; Luchansky, J B; Porto-Fett, A C S; Phillips, J G

    2014-03-01

    The effect of high-hydrostatic-pressure processing (HPP) on the survival of a 5-strain rifampicin-resistant cocktail of Listeria monocytogenes in Queso Fresco (QF) was evaluated as a postpackaging intervention. Queso Fresco was made using pasteurized, homogenized milk, and was starter-free and not pressed. In phase 1, QF slices (12.7 × 7.6 × 1 cm), weighing from 52 to 66 g, were surface inoculated with L. monocytogenes (ca. 5.0 log10 cfu/g) and individually double vacuum packaged. The slices were then warmed to either 20 or 40°C and HPP treated at 200, 400, and 600 MPa for hold times of 5, 10, 15, or 20 min. Treatment at 600 MPa was most effective in reducing L. monocytogenes to below the detection level of 0.91 log10 cfu/g at all hold times and temperatures. High-hydrostatic-pressure processing at 40°C, 400 MPa, and hold time ≥ 15 min was effective but resulted in wheying-off and textural changes. In phase 2, L. monocytogenes was inoculated either on the slices (ca. 5.0 log10 cfu/g; ON) or in the curds (ca. 7.0 log10 cfu/g; IN) before the cheese block was formed and sliced. The slices were treated at 20°C and 600 MPa at hold times of 3, 10, and 20 min, and then stored at 4 and 10°C for 60 d. For both treatments, L. monocytogenes became less resistant to pressure as hold time increased, with greater percentages of injured cells at 3 and 10 min than at 20 min, at which the lethality of the process increased. For the IN treatment, with hold times of 3 and 10 min, growth of L. monocytogenes increased the first week of storage, but was delayed for 1 wk, with a hold time of 20 min. Longer lag times in growth of L. monocytogenes during storage at 4°C were observed for the ON treatment at hold times of 10 and 20 min, indicating that the IN treatment may have provided a more protective environment with less injury to the cells than the ON treatment. Similarly, HPP treatment for 10 min followed by storage at 4°C was the best method for suppressing the growth of

  17. Photochemical reduction of methyl viologen in silicate xerogels obtained by the sol gel process

    NASA Astrophysics Data System (ADS)

    Maruszewski, Krzysztof; Jasiorski, Marek; Hreniak, Dariusz; Stręk, Wiesław

    2001-10-01

    Mixture of ruthenium (II) tris-bipyridine complex (Ru(bpy) 32+ — photosensitizer), methyl viologen (MV 2+ — electron acceptor) and EDTA (sacrificial electron donor) has been immobilized in silicate xerogels obtained by the sol-gel technique. Mixtures of Ru(bpy) 32+, MV 2+ and EDTA are capable of formation of the blue photoreduced MV rad + cation radical in aqueous solutions upon UV (around 280 nm) or visible (around 450 nm) excitations. However, when entrapped in silicate xerogels they do not exhibit blue coloration at all. On the other hand, UV excitation of xerogels doped only with MV 2+ results in appearance of blue color indicative of the paraquat photoreduction. It has been shown that in the case of the xerogel-entrapped methyl viologen the source of the reducing photoelectron is ethanol. The alcohol molecules are produced during the tetraethoxysilane (precursor) hydrolysis step of the silicate matrix production occurring via the sol-gel process.

  18. Reduction of antiproliferative capacities, cell-based antioxidant capacities and phytochemical contents of common beans and soybeans upon thermal processing.

    PubMed

    Xu, Baojun; Chang, Sam K C

    2011-12-01

    The effects of boiling and steaming processes on the antiproliferative and cellular antioxidant properties, as well as phytochemicals, of two types of common beans (pinto and black beans) and two types of soybeans (yellow and black) were investigated. All thermal-processing methods caused significant (p<0.05) decreases in total phenolic content (TPC), total saponin content (TSC) and phytic acid content (PAC) values in all bean types (except for TPC values in pressure-steamed yellow soybeans) as compared to those of the raw beans. All types of uncooked raw beans exhibited cellular antioxidant activities (CAA) in dose-dependent manners. Black soybeans exhibited the greatest CAA, followed by black beans, pinto beans and yellow soybeans. The CAA of cooked beans were generally diminished or eliminated by thermal processing. The hydrophilic extracts from raw pinto beans, black beans and black soybeans exhibited antiproliferation capacities against human gastric (AGS) and colorectal (SW480) cancer cells in dose-dependent manners. The raw yellow soybeans exhibited dose-dependent antiproliferation activities against the SW480 cells. Most of the cooked beans lost their antiproliferation capacities as observed in the raw beans. These results indicate that different processing methods may have various effects on phytochemical profiles and bioactivities. Overall, thermal processing caused a significant reduction of the health-promotion effects of beans.

  19. The Relationship of the Facial Nerve to the Condylar Process: A Cadaveric Study with Implications for Open Reduction Internal Fixation.

    PubMed

    Barham, H P; Collister, P; Eusterman, V D; Terella, A M

    2015-01-01

    Introduction. The mandibular condyle is the most common site of mandibular fracture. Surgical treatment of condylar fractures by open reduction and internal fixation (ORIF) demands direct visualization of the fracture. This project aimed to investigate the anatomic relationship of the tragus to the facial nerve and condylar process. Materials and Methods. Twelve fresh hemicadavers heads were used. An extended retromandibular/preauricular approach was utilized, with the incision being based parallel to the posterior edge of the ramus. Measurements were obtained from the tragus to the facial nerve and condylar process. Results. The temporozygomatic division of the facial nerve was encountered during each approach, crossing the mandible at the condylar neck. The mean tissue depth separating the facial nerve from the condylar neck was 5.5 mm (range: 3.5 mm-7 mm, SD 1.2 mm). The upper division of the facial nerve crossed the posterior border of the condylar process on average 2.31 cm (SD 0.10 cm) anterior to the tragus. Conclusions. This study suggests that the temporozygomatic division of the facial nerve will be encountered in most approaches to the condylar process. As visualization of the relationship of the facial nerve to condyle is often limited, recognition that, on average, 5.5 mm of tissue separates condylar process from nerve should help reduce the incidence of facial nerve injury during this procedure.

  20. Knife grid size reduction to pre-process packed beds of high- and low-moisture switchgrass.

    PubMed

    Igathinathane, C; Womac, A R; Sokhansanj, S; Narayan, S

    2008-05-01

    A linear knife grid device was developed for first-stage size reduction of high- and low-moisture switchgrass (Panicum virgatum L.), a tough, fibrous perennial grass being considered as a feedstock for bioenergy. The size reduction is by a shearing action accomplished by forcing a thick packed bed of biomass against a grid of sharp knives. The system is used commercially for slicing forages for drying or feed mixing. No performance data or engineering equations are available in published literature to optimize the machine and the process for biomass size reductions. Tests of a linear knife grid with switchgrass quantified the combined effect of shearing stresses, packed bed consolidation, and frictional resistance to flow through a knife grid. A universal test machine (UTM) measured load-displacement of switchgrass at two moisture contents: 51%, and 9% wet basis; three knife grid spacings: 25.4, 50.8, and 101.6mm; and three packed bed depths: 50.8, 101.6, and 152.4mm. Results showed that peak load, ultimate shear stress, and cutting energy values varied inversely with knife grid spacing and directly with packed bed depth (except ultimate shear stress). Mean ultimate shear stresses of high- and low-moisture switchgrass were 0.68+/-0.24, and 0.41+/-0.21 MPa, mass-based cutting energy values were 4.50+/-4.43, and 3.64+/-3.31 MJ/dry Mg, and cutting energy based on new surface area, calculated from packed-circle theory, were 4.12+/-2.06, and 2.53+/-0.45 kJ/m2, respectively. The differences between high- and low-moisture switchgrass were significant (P<0.05), such that high-moisture switchgrass required increased shear stress and cutting energy. Reduced knife grid spacing and increased packed bed depths required increased cutting energy. Overall, knife grid cutting energy was much less than energy values published for rotary equipment. A minimum knife grid spacing of 25.4mm appears to be a practical lower limit, considering the high ram force that would be needed for

  1. Reduction of nitrous oxide emissions from partial nitrification process by using innovative carbon source (mannitol).

    PubMed

    Zhang, Xinwen; Wang, Xiaoqing; Zhang, Jian; Huang, Xiaoyu; Wei, Dong; Lan, Wei; Hu, Zhen

    2016-10-01

    The purpose of this study was to evaluate the effect of mannitol as carbon source on nitrogen removal and nitrous oxide (N2O) emission during partial nitrification (PN) process. Laboratory-scale PN sequencing batch reactors (SBRs) were operated with mannitol and sodium acetate as carbon sources, respectively. Results showed that mannitol could remarkably reduce N2O-N emission by 41.03%, without influencing the removal efficiency of NH4(+)-N. However, it has a significant influence on nitrite accumulation ratio (NAR) and TN removal, which were 19.97% and 13.59% lower than that in PN with sodium acetate, respectively. Microbial analysis showed that the introduction of mannitol could increase the abundance of bacteria encoding nosZ genes. In addition, anti-oxidant enzymes (T-SOD, POD and CAT) activities were significantly reduced and the dehydrogenase activity had an obvious increase in mannitol system, indicating that mannitol could alleviate the inhibition of N2O reductase (N2OR) activities caused by high NO2(-)-N concentration.

  2. Facile Synthesis of Nb3Sn Via a Hydrogen Reduction Process

    NASA Astrophysics Data System (ADS)

    Zhu, Jun; Jiao, Shuqiang; Zhang, Long; Li, Yanxiang; Zhu, Hongmin

    2017-02-01

    A controllable and facile process for the preparation of Nb3Sn intermetallic compound nanopowders using NbCl5 and SnCl2 vapors reduced by hydrogen has been developed. The vaporizing rates of the two chlorides are controlled by measuring their mass loss as a function of carrier gas (argon) flow rate at certain vaporization temperatures, respectively. X-ray diffraction (XRD) patterns indicate that hydrogenous Nb3Sn products are obtained under the vaporizing rate of 0.155 g min-1 for NbCl5 and 0.036 g min-1 for SnCl2 with the hydrogen flow rate of 2100 ml min-1 at 1273 K (1000 °C). Results of semi-quantitative analysis by X-ray fluorescence (XRF) demonstrate that the atomic ratio of Nb to Sn in the as-synthesized products is 3.48:1, and the content of (Nb + Sn) is taken up to 89.61 wt pct from the total weight of the products. The products can be purified by vacuum heat treatment. Images of transmission electron microscopy (TEM) show that the products are homogenous particles with a mean diameter of 31 nm. In addition, the reaction ratio of the chlorides and the powder yield are controllable by hydrogen flow rate.

  3. Hubble Space Telescope: cost reduction by re-engineering telemetry processing and archiving

    NASA Astrophysics Data System (ADS)

    Miebach, Manfred P.

    1998-05-01

    The Hubble Space Telescope (HST), the first of NASA's Great Observatories, was launched on April 24, 1990. The HST was designed for a minimum fifteen-year mission with on-orbit servicing by the Space Shuttle System planned at approximately three-year intervals. Major changes to the HST ground system are planned to be in place for the third servicing mission in December 1999. The primary objectives of the ground system reengineering effort, a project called 'vision December 1999. The primary objectives of the ground system re-engineering effort, a project called 'vision 2000 control center systems (CCS)', are to reduce both development and operating costs significantly for the remaining years of HST's lifetime. Development costs will be reduced by providing a modern hardware and software architecture and utilizing commercial of f the shelf (COTS) products wherever possible. Operating costs will be reduced by eliminating redundant legacy systems and processes and by providing an integrated ground system geared toward autonomous operation. Part of CCS is a Space Telescope Engineering Data Store, the design of which is based on current Data Warehouse technology. The purpose of this data store is to provide a common data source of telemetry data for all HST subsystems. This data store will become the engineering data archive and will include a queryable database for the user to analyze HST telemetry. The access to the engineering data in the Data Warehouse is platform- independent from an office environment using commercial standards. Latest internet technology is used to reach the HST engineering community. A WEB-based user interface allows easy access to the data archives. This paper will provide a high level overview of the CCS system and will illustrate some of the CCS telemetry capabilities. Samples of CCS user interface pages will be given. Vision 2000 is an ambitious project, but one that is well under way. It will allow the HST program to realize reduced

  4. Development of scribing process of coated conductors for reduction of AC losses

    NASA Astrophysics Data System (ADS)

    Suzuki, K.; Yoshizumi, M.; Izumi, T.; Shiohara, Y.; Iwakuma, M.; Ibi, A.; Miyata, S.; Yamada, Y.

    2008-09-01

    Coated conductors (CCs) are prospective for electric power applications intended for not only better cost performance but also high critical current density ( Jc) under magnetic fields comparing with Bi 2Sr 2Ca 2Cu 3O y (BSCCO) tapes. Furthermore, they also have a possibility to reduce AC losses by various methods of post-treatments since the CCs are of a laminated structure with the insulating buffer layers. Multifilamentation by narrowing the tape width is quite effective to reduce the AC losses and therefore this approach is valid for the standard process to fabricate practical CCs with an appropriate architecture. In this study, we developed a tape scribing technique applying a technique of YAG laser with/without chemical etching to control the filament width in YBa 2Cu 3O y (YBCO) CCs for the multifilament. The AC loss was reducible to one-twentieth by 20-multifilament structure in a short sample test, and to one-third by 3-multifilament structure in the coil using 28 m long tapes in total. The authors measured the resistance between the filaments at 60-300 K after post-treatment to investigate the effective bridged materials, which is essential for decoupling of the filaments. We improved the resistance value between the filaments at liquid nitrogen temperature up to the order of 10 Ω/cm using the YAG laser with high-temperature oxygen anneals. Furthermore, the resistance over 10 6 Ω/cm was evident by the combination of laser scribing and chemical etching, which is much higher than the requirements of all the applications.

  5. Effects of dissolved oxygen on performance and microbial community structure in a micro-aerobic hydrolysis sludge in situ reduction process.

    PubMed

    Niu, Tianhao; Zhou, Zhen; Shen, Xuelian; Qiao, Weimin; Jiang, Lu-Man; Pan, Wei; Zhou, Jijun

    2016-03-01

    A sludge process reduction activated sludge (SPRAS), with a sludge process reduction module composed of a micro-aerobic tank and a settler positioned before conventional activated sludge process, showed good performance of pollutant removal and sludge reduction. Two SPRAS systems were operated to investigate effects of micro-aeration on sludge reduction performance and microbial community structure. When dissolved oxygen (DO) concentration in the micro-aerobic tank decreased from 2.5 (SPH) to 0.5 (SPL) mg/L, the sludge reduction efficiency increased from 42.9% to 68.3%. Compared to SPH, activated sludge in SPL showed higher contents of extracellular polymeric substances and dissolved organic matter. Destabilization of floc structure in the settler, and cell lysis in the sludge process reduction module were two major reasons for sludge reduction. Illumina-MiSeq sequencing showed that microbial diversity decreased under high DO concentration. Proteobacteria, Bacteroidetes and Chloroflexi were the most abundant phyla in the SPRAS. Specific comparisons down to the class and genus level showed that fermentative, predatory and slow-growing bacteria in SPL community were more abundant than in SPH. The results revealed that micro-aeration in the SPRAS improved hydrolysis efficiency and enriched fermentative and predatory bacteria responsible for sludge reduction.

  6. TiO2 Processed by pressurized hot solvents as a novel photocatalyst for photocatalytic reduction of carbon dioxide

    NASA Astrophysics Data System (ADS)

    Reli, Martin; Kobielusz, Marcin; Matějová, Lenka; Daniš, Stanislav; Macyk, Wojciech; Obalová, Lucie; Kuśtrowski, Piotr; Rokicińska, Anna; Kočí, Kamila

    2017-01-01

    Anatase-brookite TiO2 photocatalysts were prepared by the sol-gel process controlled within reverse micelles and processing by pressurized hot solvents-water/methanol/water (TiO2(M)) and water/ethanol/water (TiO2(E)), as an unconventional alternative to common calcination. The main goal of this work was to prepare anatase-brookite mixtures by processing by two different alcohols (methanol and ethanol) and evaluate the influence of the alcohol on the photocatalytic activity. Prepared photocatalysts were characterized by organic elemental analysis, nitrogen physisorption, XRD, UV-vis, photoelectrochemical and spectroelectrochemical measurements and XPS. The prepared photocatalysts efficiency was tested on the photocatalytic reduction of carbon dioxide and compared with commercial TiO2 Evonik P25. Both prepared nanocomposites were more efficient towards methane production but Evonik P25 was the most efficient towards hydrogen generated through water splitting. The higher performance of anatase-brookite mixture towards methane production can be explained by (i) a higher photocatalytic activity of brookite than rutile; (ii) a large surface area of anatase-brookite composites enabling better carbon dioxide adsorption; (iii) the photoinduced electron transfer from the brookite conduction band to the anatase conduction band. On the other hand, a higher production of hydrogen in the presence of Evonik P25 is caused by a better charge separation in anatase-rutile than anatase-brookite phase compositions. TiO2(M) appeared more active than TiO2(E) in the photocatalytic reduction of carbon dioxide due to a lower density of defects created in the crystal lattice.

  7. Magnesium production by the Pidgeon process involving dolomite calcination and MgO silicothermic reduction: Thermodynamic and environmental analyses

    SciTech Connect

    Halmann, M.; Frei, A.; Steinfeld, A.

    2008-04-15

    Thermochemical equilibrium calculations indicate the possibility of considerable fuel savings and CO{sub 2} emission avoidance in the three steps of the Pidgeon process: (a) calcination of dolomite; (b) production of ferrosilicon from quartz sand, coal, and iron oxide; (c) silicothermic reduction of calcined dolomite by ferrosilicon to magnesium. All three steps should benefit from application of concentrated solar energy as the source of high-temperature process heat, while the first two steps may be adapted to the coproduction of syngas. For the production of ferrosilicon, an experimental study was carried out by thermogravimetry as a model for a solar-driven process. The net reaction at 1823 K was shown to be represented by Fe{sub 2}O{sub 3} + 4SiO{sub 2} + 11C {yields} 2FeSi{sub s} + 10CO{sub g} + SiC{sub s} + SiO{sub g}, confirmed by gas chromatographic analysis of the evolved CO and by XRD identification of the solid products FeSi and SiC. This product mixture agrees with that predicted for the thermochemical equilibrium, but differs from that reported in the literature for the electric arc process.

  8. Rapid Automated Treatment Planning Process to Select Breast Cancer Patients for Active Breathing Control to Achieve Cardiac Dose Reduction

    SciTech Connect

    Wang Wei; Purdie, Thomas G.; Rahman, Mohammad; Marshall, Andrea; Liu Feifei; Fyles, Anthony

    2012-01-01

    Purpose: To evaluate a rapid automated treatment planning process for the selection of patients with left-sided breast cancer for a moderate deep inspiration breath-hold (mDIBH) technique using active breathing control (ABC); and to determine the dose reduction to the left anterior descending coronary artery (LAD) and the heart using mDIBH. Method and Materials: Treatment plans were generated using an automated method for patients undergoing left-sided breast radiotherapy (n = 53) with two-field tangential intensity-modulated radiotherapy. All patients with unfavorable cardiac anatomy, defined as having >10 cm{sup 3} of the heart receiving 50% of the prescribed dose (V{sub 50}) on the free-breathing automated treatment plan, underwent repeat scanning on a protocol using a mDIBH technique and ABC. The doses to the LAD and heart were compared between the free-breathing and mDIBH plans. Results: The automated planning process required approximately 9 min to generate a breast intensity-modulated radiotherapy plan. Using the dose-volume criteria, 20 of the 53 patients were selected for ABC. Significant differences were found between the free-breathing and mDIBH plans for the heart V{sub 50} (29.9 vs. 3.7 cm{sup 3}), mean heart dose (317 vs. 132 cGy), mean LAD dose (2,047 vs. 594 cGy), and maximal dose to 0.2 cm{sup 3} of the LAD (4,155 vs. 1,507 cGy, all p <.001). Of the 17 patients who had a breath-hold threshold of {>=}0.8 L, 14 achieved a {>=}90% reduction in the heart V{sub 50} using the mDIBH technique. The 3 patients who had had a breath-hold threshold <0.8 L achieved a lower, but still significant, reduction in the heart V{sub 50}. Conclusions: A rapid automated treatment planning process can be used to select patients who will benefit most from mDIBH. For selected patients with unfavorable cardiac anatomy, the mDIBH technique using ABC can significantly reduce the dose to the LAD and heart, potentially reducing the cardiac risks.

  9. Chromate reduction in Fe(II)-containing soil affected by hyperalkaline leachate from chromite ore processing residue.

    PubMed

    Whittleston, Robert A; Stewart, Douglas I; Mortimer, Robert J G; Tilt, Zana C; Brown, Andrew P; Geraki, Kalotina; Burke, Ian T

    2011-10-30

    Highly alkaline (pH 12.2) chromate contaminated leachate (990 μmol L(-1)) has been entering soils below a chromite ore processing residue disposal (COPR) site for over 100 years. The soil immediately beneath the waste has a pH of 11→12.5, contains 0.3→0.5% (w/w) chromium, and 45→75% of the microbially available iron is Fe(II). Despite elevated pH, a viable microbial consortium of Firmicutes dominated iron reducers was isolated from this COPR affected soil. Soil pH and Cr concentration decrease with distance from the waste. XAS analysis of soil samples indicated that Cr is present as a mixed Cr(III)-Fe(III) oxy-hydroxide phase, suggesting that the elevated soil Cr content is due to reductive precipitation of Cr(VI) by Fe(II). Microcosm results demonstrate the capacity of COPR affected soil to abiotically remove all Cr(VI) from the leachate within 40 days. In air oxidation experiments less than 2% of the total Cr in the soil was remobilised despite significant Fe(II) oxidation. XAS analysis after air oxidation showed no change in Cr-speciation, indicating the Cr(III)-containing phase is a stable long term host for Cr. This work suggests that reductive precipitation of Cr(VI) is an effective method of contaminant immobilisation in soils where microbially produced Fe(II) is present.

  10. Heterotrophic and elemental-sulfur-based autotrophic denitrification processes for simultaneous nitrate and Cr(VI) reduction.

    PubMed

    Sahinkaya, Erkan; Kilic, Adem

    2014-03-01

    Nitrate and chromate can be present together in water resources as nitrate is a common co-contaminant in surface and ground waters. This study aims at comparatively evaluating simultaneous chromate and nitrate reduction in heterotrophic and sulfur-based autotrophic denitrifying column bioreactors. In sulfur-based autotrophic denitrification process, elemental sulfur and nitrate act as an electron donor and an acceptor, respectively, without requirement of organic supplementation. Autotrophic denitrification was complete and not adversely affected by chromate up to 0.5 mg/L. Effluent chromate concentration was <50 μg/L provided that influent chromate concentration was ≤0.5 mg/L. Heterotrophic denitrification performance was not adversely affected even at 20 mg/L chromate and complete chromate reduction was attained up to 10 mg/L. Although autotrophic denitrification rate was much lower compared with heterotrophic one, it may be preferred in drinking water treatment due to the elimination of organic supplementation and the risk of treated effluent contamination.

  11. Effect of process variables on the sulfate reduction process in bioreactors treating metal-containing wastewaters: factorial design and response surface analyses.

    PubMed

    Villa-Gomez, D K; Pakshirajan, K; Maestro, R; Mushi, S; Lens, P N L

    2015-07-01

    The individual and combined effect of the pH, chemical oxygen demand (COD) and SO4 (2-) concentration, metal to sulfide (M/S(2-)) ratio and hydraulic retention time (HRT) on the biological sulfate reduction (SR) process was evaluated in an inverse fluidized bed reactor by factorial design analysis (FDA) and response surface analysis (RSA). The regression-based model of the FDA described the experimental results well and revealed that the most significant variable affecting the process was the pH. The combined effect of the pH and HRT was barely observable, while the pH and COD concentration positive effect (up to 7 and 3 gCOD/L, respectively) enhanced the SR process. Contrary, the individual COD concentration effect only enhanced the COD removal efficiency, suggesting changes in the microbial pathway. The RSA showed that the M/S(2-) ratio determined whether the inhibition mechanism to the SR process was due to the presence of free metals or precipitated metal sulfides.

  12. Reduction of chromate from electroplating wastewater from pH 1 to 2 using fluidized zero valent iron process.

    PubMed

    Chen, Shiao-Shing; Cheng, Chih-Yu; Li, Chi-Wang; Chai, Pao-Hsuan; Chang, Yu-Min

    2007-04-02

    Fluidized zero valent iron (ZVI) process was conducted to reduce hexavalent chromium (chromate, CrO(4)(2-)) to trivalent chromium (Cr(3+)) from electroplating wastewater due to the following reasons: (1) Extremely low pH (1-2) for the electroplating wastewater favoring the ZVI reaction. (2) The ferric ion, produced from the reaction of Cr(VI) and ZVI, can act as a coagulant to assist the precipitation of Cr(OH)(3(s)) to save the coagulant cost. (3) Higher ZVI utilization for fluidized process due to abrasive motion of the ZVI. For influent chromate concentration of 418 mg/L as Cr(6+), pH 2 and ZVI dosage of 3g (41 g/L), chromate removal was only 29% with hydraulic detention time (HRT) of 1.2 min, but was increased to 99.9% by either increasing HRT to 5.6 min or adjusting pH to 1.5. For iron species at pH 2 and HRT of 1.2 min, Fe(3+) was more thermodynamically stable since oxidizing agent chromate was present. However, if pH was adjusted to 1.5 or 1, where chromate was completely removed, high Fe(2+) but very low Fe(3+) was present. It can be explained that ZVI reacted with chromate to produce Fe(2+) first and the presence of chromate would keep converting Fe(2+) to Fe(3+). Therefore, Fe(2+) is an indicator for complete reduction from Cr(VI) to Cr(III). X-ray diffraction (XRD) was conducted to exam the remained species at pH 2. ZVI, iron oxide and iron sulfide were observed, indicating the formation of iron oxide or iron sulfide could stop the chromate reduction reaction.

  13. Revisiting Training and Verification Process Implementation for Risk Reduction on New Missions at NASA Jet Propulsion Laboratory

    NASA Technical Reports Server (NTRS)

    Bryant, Larry W.; Fragoso, Ruth S.

    2007-01-01

    In 2003 we proposed an effort to develop a core program of standardized training and verification practices and standards against which the implementation of these practices could be measured. The purpose was to provide another means of risk reduction for deep space missions to preclude the likelihood of a repeat of the tragedies of the 1998 Mars missions. We identified six areas where the application of standards and standardization would benefit the overall readiness process for flight projects at JPL. These are Individual Training, Team Training, Interface and Procedure Development, Personnel Certification, Interface and procedure Verification, and Operations Readiness Testing. In this paper we will discuss the progress that has been made in the tasks of developing the proposed infrastructure in each of these areas. Specifically we will address the Position Training and Certification Standards that are now available for each operational position found on our Flight Operations Teams (FOT). We will also discuss the MGSS Baseline Flight Operations Team Training Plan which can be tailored for each new flight project at JPL. As these tasks have been progressing, the climate and emphasis for Training and for V and V at JPL has changed, and we have learned about the expansion, growth, and limitations in the roles of traditional positions at JPL such as the Project's Training Engineer, V and V Engineer, and Operations Engineer. The need to keep a tight rein on budgets has led to a merging and/or reduction in these positions which pose challenges to individual capacities and capabilities. We examine the evolution of these processes and the roles involved while taking a look at the impact or potential impact of our proposed training related infrastructure tasks. As we conclude our examination of the changes taking place for new flight projects, we see that the importance of proceeding with our proposed tasks and adapting them to the changing climate remains an important

  14. Energy Saving Melting and Revert Reduction Technology: Improved Die Casting Process to Preserve the Life of the Inserts

    SciTech Connect

    David Schwam, PI; Xuejun Zhu, Sr. Research Associate

    2012-09-30

    lubricants and technical support. Experiments conducted with these lubricants demonstrated good protection of the substrate steel. Graphite and boron nitride used as benchmarks are capable of completely eliminating soldering and washout. However, because of cost and environmental considerations these materials are not widely used in industry. The best water-based die lubricants evaluated in this program were capable of providing similar protection from soldering and washout. In addition to improved part quality and higher production rates, improving die casting processes to preserve the life of the inserts will result in energy savings and a reduction in environmental wastes. Improving die life by means of optimized cooling line placement, baffles and bubblers in the die will allow for reduced die temperatures during processing, saving energy associated with production. The utilization of optimized die lubricants will also reduce heat requirements in addition to reducing waste associated with soldering and washout. This new technology was predicted to result in an average energy savings of 1.1 trillion BTU's/year over a 10 year period. Current (2012) annual energy saving estimates, based on commercial introduction in 2010, a market penetration of 70% by 2020 is 1.26 trillion BTU's/year. Along with these energy savings, reduction of scrap and improvement in casting yield will result in a reduction of the environmental emissions associated with the melting and pouring of the metal which will be saved as a result of this technology. The average annual estimate of CO2 reduction per year through 2020 is 0.025 Million Metric Tons of Carbon Equivalent (MM TCE).

  15. Challenges and Recent Developments in Hearing Aids: Part II. Feedback and Occlusion Effect Reduction Strategies, Laser Shell Manufacturing Processes, and Other Signal Processing Technologies

    PubMed Central

    Chung, King

    2004-01-01

    This is the second part of a review on the challenges and recent developments in hearing aids. Feedback and the occlusion effect pose great challenges in hearing aid design and usage. Yet, conventional solutions to feedback and the occlusion effect often create a dilemma: the solution to one often leads to the other. This review discusses the advanced signal processing strategies to reduce feedback and some new approaches to reduce the occlusion effect. Specifically, the causes of three types of feedback (acoustic, mechanical, and electromagnetic) are discussed. The strategies currently used to reduce acoustic feedback (i.e., adaptive feedback reduction algorithms using adaptive gain reduction, notch filtering, and phase cancellation strategies) and the design of new receivers that are built to reduce mechanical and electromagnetic feedback are explained. In addition, various new strategies (i.e., redesigned sound delivery devices and receiver-in-the-ear-canal hearing aid configuration) to reduce the occlusion effect are reviewed. Many manufacturers have recently adopted laser shell-manufacturing technologies to overcome problems associated with manufacturing custom hearing aid shells. The mechanisms of selected laser sintering and stereo lithographic apparatus and the properties of custom shells produced by these two processes are reviewed. Further, various new developments in hearing aid transducers, telecoils, channel-free amplification, open-platform programming options, rechargeable hearing aids, ear-level frequency modulated (FM) receivers, wireless Bluetooth FM systems, and wireless programming options are briefly explained and discussed. Finally, the applications of advanced hearing aid technologies to enhance other devices such as cochlear implants, hearing protectors, and cellular phones are discussed. PMID:15735871

  16. On the Development of a Zinc Vapor Condensation Process for the Solar Carbothermal Reduction of Zinc Oxide

    NASA Astrophysics Data System (ADS)

    Tzouganatos, N.; Dell'amico, M.; Wieckert, C.; Hinkley, J.; Steinfeld, A.

    2015-05-01

    In the conventional Imperial Smelting Process, the dominating pyrometallurgical zinc production process, zinc vapor is recovered from the furnace off-gas by absorption into an intense spray of molten lead droplets in a splash condenser, followed by separation of zinc from the Zn-Pb alloy upon cooling from 550°C to 450°C by taking advantage of the decrease in the solubility of zinc in lead at lower temperatures. The adaptation of this condenser technology into a solar-driven thermochemical plant using concentrated solar energy faces several drawbacks owing to its mechanical complications and the continuous recirculation of large quantities of lead. An alternative zinc condenser concept involving gas bubbling through a zinc liquid bath of the off-gas evolved from the carbothermal reduction of ZnO is thus proposed and numerically modeled for transient heat and mass transfer. Condensation of bubbles containing 53.5% of noncondensable gases yielded chemical conversions of Zn(g) to Zn(l) in the range of 95.6-99.8% for operation in the temperature range 500-650°C while conversions of Zn(g) to ZnO in the order of 10-6 were obtained, thus predicting successful suppression of Zn(g) reoxidation by CO2 and CO.

  17. Influence of Ca amount on the synthesis of Nd2Fe14B particles in reduction-diffusion process

    NASA Astrophysics Data System (ADS)

    Chen, Chun-Qiang; Kim, Dongsoo; Choi, Chuljin

    2014-04-01

    Nd2Fe14B alloy particles with high coercivity of more than 10 kOe were successfully synthesized by adjusting the amount of Calcium (Ca) in reduction-diffusion (R-D) process. Calcium oxide (CaO) and unreacted Ca remained after R-D process in particles prepared by heat treatment in Hydrogen (H2) atmosphere at previous step. In the ratio of 0.4 of Ca to powders (Ca/powders, wt%), residual Ca was not detected from X-ray diffraction pattern. On the other hand, Ca appeared above the ratio of 1.0 and below the ratio of 0.2, amount of Ca was not enough to reduce Nd oxide. Moreover, excess Ca affected magnetic property of final products obtained after washing, because residual Ca gave rise to evolution of H2 gas during disintegration with water and it led to the formation of Nd2Fe14BHx (x=1-5). Finally, Nd2Fe14B magnetic particles were synthesized after washing in de-ionized water with a mean size of 2 μm and their maximum energy product showed 15.5 MGOe.

  18. Reduction of the interfacial trap density of indium-oxide thin film transistors by incorporation of hafnium and annealing process

    SciTech Connect

    Lin, Meng-Fang E-mail: TSUKAGOSHI.Kazuhito@nims.go.jp; Gao, Xu; Mitoma, Nobuhiko; Kizu, Takio; Ou-Yang, Wei; Tsukagoshi, Kazuhito E-mail: TSUKAGOSHI.Kazuhito@nims.go.jp; Aikawa, Shinya; Nabatame, Toshihide

    2015-01-15

    The stable operation of transistors under a positive bias stress (PBS) is achieved using Hf incorporated into InO{sub x}-based thin films processed at relatively low temperatures (150 to 250 °C). The mobilities of the Hf-InO{sub x} thin-film transistors (TFTs) are higher than 8 cm{sup 2}/Vs. The TFTs not only have negligible degradation in the mobility and a small shift in the threshold voltage under PBS for 60 h, but they are also thermally stable at 85 °C in air, without the need for a passivation layer. The Hf-InO{sub x} TFT can be stable even annealed at 150 °C for positive bias temperature stability (PBTS). A higher stability is achieved by annealing the TFTs at 250 °C, originating from a reduction in the trap density at the Hf-InO{sub x}/gate insulator interface. The knowledge obtained here will aid in the realization of stable TFTs processed at low temperatures.

  19. Extracellular synthesis of cuprous selenide nanospheres by a biological-chemical coupling reduction process in an anaerobic microbial system.

    PubMed

    Yue, Lei; Wang, Jia; Qi, Shiyue; Xin, Baoping

    2016-09-01

    Biosynthesis of metal nanoparticles represents a clean, eco-friendly and sustainable "green chemistry" engineering. Lately, a number of metal selenides were successfully synthesized by biological methods. Here, cuprous selenide (Cu2 Se) nanospheres were prepared under mild conditions by a novel biological-chemical coupling reduction process. The simple process takes place between EDTA-Cu and Na2 SeO3 in presence of an alkaline solution containing NaBH4 and a selenite-reducing bacteria, Pantoea agglomerans. It is noteworthy that the isolated Pantoea agglomerans and Cu(+) ions, where the latter are obtained from reducing Cu(2+) ions by NaBH4 , play a key role, and Cu(+) ions not only can promote the generation of Se(2-) ions as a catalyst, but also can react with Se(2-) ions to form Cu2 Se. XRD pattern, SEM, and TEM images indicated that Cu2 Se nanoparticles were tetragonal crystal structure and the nanospheres diameter were about 100 nm. EDX, UV-vis, and FTIR spectra show that the biosynthesized Cu2 Se nanospheres are wrapped by protein and have a better stability. This work first proposes a new biosynthesis mechanism, and has important reference value for biological preparation of metal selenide nanomaterials. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1264-1270, 2016.

  20. Preserving the Self: The Process of Decision Making About Hereditary Breast Cancer and Ovarian Cancer Risk Reduction

    PubMed Central

    Howard, A. Fuchsia; Balneaves, Lynda G.; Bottorff, Joan L.; Rodney, Patricia

    2016-01-01

    Women who carry BRCA1 or BRCA2 (BRCA1/2) gene mutations have up to an 88% lifetime risk of breast cancer and up to a 65% lifetime risk of ovarian cancer. Strategies to address these risks include cancer screening and risk-reducing surgery (i.e., mastectomy and salpingo-oophorectomy). We conducted a grounded theory study with 22 BRCA1/2 mutation-carrier women to understand how women make decisions about these risk-reducing strategies. Preserving the self was the overarching decision-making process evident in the participants’ descriptions. This process was shaped by contextual conditions including the characteristics of health services, the nature of hereditary breast and ovarian cancer risk-reduction decisions, gendered roles, and the women’s perceived proximity to cancer. The women engaged in five decision-making styles, and these were characterized by the use of specific decision-making approaches. These findings provide theoretical insights that could inform the provision of decisional support to BRCA1/2 carriers. PMID:20980697

  1. XPS study of reductive dissolution of birnessite by oxalate: Rates and mechanistic aspects of dissolution and redox processes

    SciTech Connect

    Banerjee, D.; Nesbitt, H.W.

    1999-10-01

    Reductive dissolution of synthetic 7{angstrom}-birnessite [MnO{sub 1.7}(OH){sub 0.25} or MnO{sub 1.95}] by Na-oxalate produces a Mn(III) intermediate reaction product (here represented as MnOOH) which subsequently reacts with sorbed (COO){sub 2}{sup {minus}2} to form an unreactive Mn(III)-oxalate surface complex at the solution-mineral interface. X-ray Photoelectron Spectroscopy (XPS) results from Mn2p{sub 3/2}, C1s and O1s spectra of reacted surfaces reveal that initially rapid production of CO{sub 2} results in accumulation of CO{sub 2} at the reaction interface. After about 15 min, the reaction rate decreases to the point where CO{sub 2} desorption keeps pace with accumulation. Surface concentrations of CO{sub 2} suggest that the rate of CO{sub 2} production decreases with time, until after 10 hr of reaction, it is undetectable. Reduction of Mn(IV) to Mn(III) suggests that the MnO{sub 2}-oxalate redox reaction proceeds as a transfer of one electron per metal center. There is no XPS evidence for reduction of Mn(III) from birnessite to Mn(II) in the presence of oxalate. Although this reaction proceeds in presence of arsenite, it is inhibited by oxalate, probably through formation of a strong Mn(III)-oxalate surface complex (either monodentate or bidentate). This hypothesis is consistent with Mn{sup 3+} (aq) stabilization by oxalate in aqueous solutions. Further study using X-ray absorption spectroscopy (XAS) is required for a better understanding of the structure of the surface complexes. Rate of release of soluble Mn(II) to dilute oxalate solutions (5 x 10{sup {minus}4} M) is lower by an order of magnitude than the rate of release to aerated, distilled water at similar pH. Apparently, the process of proton-promoted dissolution of the soluble Mn(II) component of birnessite in distilled water is impeded by the addition of oxalate, probably by formation of a binuclear, bidentate surface complex between Mn(II, III) and adsorbed oxalate ions.

  2. Adaptive Iterative Dose Reduction Using Three Dimensional Processing (AIDR3D) Improves Chest CT Image Quality and Reduces Radiation Exposure

    PubMed Central

    Yamashiro, Tsuneo; Miyara, Tetsuhiro; Honda, Osamu; Kamiya, Hisashi; Murata, Kiyoshi; Ohno, Yoshiharu; Tomiyama, Noriyuki; Moriya, Hiroshi; Koyama, Mitsuhiro; Noma, Satoshi; Kamiya, Ayano; Tanaka, Yuko; Murayama, Sadayuki

    2014-01-01

    Objective To assess the advantages of Adaptive Iterative Dose Reduction using Three Dimensional Processing (AIDR3D) for image quality improvement and dose reduction for chest computed tomography (CT). Methods Institutional Review Boards approved this study and informed consent was obtained. Eighty-eight subjects underwent chest CT at five institutions using identical scanners and protocols. During a single visit, each subject was scanned using different tube currents: 240, 120, and 60 mA. Scan data were converted to images using AIDR3D and a conventional reconstruction mode (without AIDR3D). Using a 5-point scale from 1 (non-diagnostic) to 5 (excellent), three blinded observers independently evaluated image quality for three lung zones, four patterns of lung disease (nodule/mass, emphysema, bronchiolitis, and diffuse lung disease), and three mediastinal measurements (small structure visibility, streak artifacts, and shoulder artifacts). Differences in these scores were assessed by Scheffe's test. Results At each tube current, scans using AIDR3D had higher scores than those without AIDR3D, which were significant for lung zones (p<0.0001) and all mediastinal measurements (p<0.01). For lung diseases, significant improvements with AIDR3D were frequently observed at 120 and 60 mA. Scans with AIDR3D at 120 mA had significantly higher scores than those without AIDR3D at 240 mA for lung zones and mediastinal streak artifacts (p<0.0001), and slightly higher or equal scores for all other measurements. Scans with AIDR3D at 60 mA were also judged superior or equivalent to those without AIDR3D at 120 mA. Conclusion For chest CT, AIDR3D provides better image quality and can reduce radiation exposure by 50%. PMID:25153797

  3. Decolorization of anthraquinone dye intermediate and its accelerating effect on reduction of azo acid dyes by Sphingomonas xenophaga in anaerobic-aerobic process.

    PubMed

    Lu, Hong; Zhou, Jiti; Wang, Jing; Ai, Haixin; Zheng, Chunli; Yang, Yusuo

    2008-09-01

    Decolorization of 1-aminoanthraquinone-2-sulfonic acid (ASA-2) and its accelerating effect on the reduction of azo acid dyes by Sphingomonas xenophaga QYY were investigated. The study showed that ASA-2 could be efficiently decolorized by strain QYY under aerobic conditions according to the analysis of total organic carbon removal and UV-VIS spectra changes. Moreover, strain QYY was able to reduce azo acid dyes under anaerobic conditions. The effects of various operating conditions such as carbon sources, temperature, and pH on the reduction rate were studied. It was demonstrated that ASA-2 used as a redox mediator could accelerate the reduction process. Consequently the reduction of azo acid dyes mediated by ASA-2 and the decolorization of ASA-2 with strain QYY could be achieved in an anaerobic-aerobic process.

  4. Multi-scale study on process of contravariant and covariant polymer elongation and drag reduction in viscoelastic turbulence

    NASA Astrophysics Data System (ADS)

    Horiuti, Kiyosi; Suzuki, Shu

    2014-11-01

    We study the elongation process of polymers released in the Newtonian homogeneous isotropic turbulence by connecting a mesoscopic description of ensemble of elastic dumbbells using Brownian dynamics (BDS) to the macroscopic description for the fluid using DNS. The dumbbells are allowed to be advected non-affinely with the macroscopically-imposed deformation. More drastic drag reduction is achieved when non-affinity is maximum than in the complete affine case. In the former case, the dumbbell is convected as a covariant vector, and in the latter as a contravariant vector. We derive the exact solution for the governing equation of the motion of dumbbells. The maximum stretching of dumbbell is achieved when the dumbbell aligns in the direction of vorticity in the contravariant case, and when the dumbbell directs outward perpendicularly on the vortex sheet in the covariant case. Alignment in the BDS-DNS data agrees with the theoretical results. In the mixture of contravariant and covariant dumbbells, the covariant dumbbells are transversely aligned with the contravariant dumbbells. Compared with the cases without mixture, stretching of covariant dumbbell is enhanced, while that of contravariant dumbbell is reduced. Application of this phenomenon is discussed.

  5. Evaluation of sludge reduction of three metabolic uncouplers in laboratory-scale anaerobic-anoxic-oxic process.

    PubMed

    Li, Ping; Li, Hechao; Li, Jin; Guo, Xuesong; Liu, Junxin; Xiao, Benyi

    2016-12-01

    To evaluate the sludge reduction of three metabolic uncouplers (3,3',4',5-tetrachlorosalicylanilide (TCS), 2,4-dichlorophenol (DCP), and tetrakis (hydroxymethyl) phosphonium sulfate (THPS)), we conducted continuous experiments on laboratory-scale anaerobic-anoxic-oxic processes. The three metabolic uncouplers were separately added in each oxic tank of the three systems, and a system without uncoupler addition was used as control. During the 85-day operation, sludge production and observed growth yields decreased to 38.6% and 16.98%, 43.4% and 17.55%, and 39.3% and 17.04% by the addition of TCS, DCP, and THPS, respectively. The addition of metabolic uncouplers slightly reduced the wastewater treatment efficiencies of the system (about 1.1-8.7%) and increased sludge SVIs (about 69.9-80.6%). Meanwhile, the differences among three metabolic uncouplers were little. Besides metabolic uncoupling and maintenance metabolism, which exist in the TCS- and DCP-added systems, lysis-cryptic growth also exists in the THPS-added system.

  6. Evaluation of various antimicrobial interventions for the reduction of Escherichia coli O157:H7 on bovine heads during processing.

    PubMed

    Kalchayanand, Norasak; Arthur, Terrance M; Bosilevac, Joseph M; Brichta-Harhay, Dayna M; Guerini, Michael N; Wheeler, Tommy L; Koohmaraie, Mohammad

    2008-03-01

    The effectiveness of electrolyzed oxidizing water, FreshFx, hot water, DL-lactic acid, and ozonated water was determined using a model carcass spray-washing cabinet. A total of 140 beef heads obtained from a commercial processing line were inoculated with Escherichia coli O157:H7 on the cheek areas. Each head was exposed to a simulated preevisceration wash and then had antimicrobial wash treatments. Hot water, lactic acid, and FreshFx treatments reduced E. coli O157:H7 on inoculated beef heads by 1.72, 1.52, and 1.06 log CFU/cm2, respectively, relative to the simulated preevisceration wash. Electrolyzed oxidizing water and ozonated water reduced E. coli O157:H7 less than 0.50 log CFU/cm2. Hot water, lactic acid, and FreshFx could be used as decontamination washes for the reduction of E. coli O157:H7 on bovine head and cheek meat.

  7. Longevity of granular iron in groundwater treatment processes: solution composition effects on reduction of organohalides and nitroaromatic compounds.

    PubMed

    Klausen, Jörg; Vikesland, Peter J; Kohn, Tamar; Burris, David R; Ball, William P; Roberts, A Lynn

    2003-03-15

    Although granular iron permeable reactive barriers (PRBs) are increasingly employed to contain subsurface contaminants, information pertaining to system longevity is sparse. The present investigation redresses this situation by examining the long-term effects of carbonate, silica, chloride, and natural organic matter (NOM) on reactivity of Master Builders iron toward organohalides and nitroaromatic contaminants. Six columns were operated for 1100 days (approximately 4500 pore volumes) and five others for 407 days (approximately 1800 pore volumes). Nine were continuously exposed to mixtures of contaminant species, while the other two were only intermittently exposed in order to differentiate deactivation induced by water (and inorganic cosolutes) from that resulting from contaminant reduction. Contaminants investigated were trichloroethylene, 1,2,3-trichloropropane, 1,1-dichloroethane, 2-nitrotoluene, 4-nitroacetophenone, and 4-nitroanisole. Column reactivity declined substantially over the first 300 days and was dependent on the feed solution chemistry. High carbonate concentrations enhanced reactivity slightly within the first 90 days but produced poorer performance over the long term. Both silica and NOM adversely affected reactivity, while chloride evinced a somewhat mixed effect. Observed contrasts in relative reactivities suggest that trichloroethylene, 1,2,3-trichloropropane, and nitroaromatic compounds all react at different types of reactive sites. Our results indicate that differences in groundwater chemistry should be considered in the PRB design process.

  8. Characterization of a Marine Microbial Community Used for Enhanced Sulfate Reduction and Copper Precipitation in a Two-Step Process.

    PubMed

    García-Depraect, Octavio; Guerrero-Barajas, Claudia; Jan-Roblero, Janet; Ordaz, Alberto

    2016-11-23

    Marine microorganisms that are obtained from hydrothermal vent sediments present a great metabolic potential for applications in environmental biotechnology. However, the work done regarding their applications in engineered systems is still scarce. Hence, in this work, the sulfate reduction process carried out by a marine microbial community in an upflow anaerobic sludge blanket (UASB) reactor was investigated for 190 days under sequential batch mode. The effects of 1000 to 5500 mg L(-1) of SO4(-2) and the chemical oxygen demand (COD)/SO4(-2) ratio were studied along with a kinetic characterization with lactate as the electron donor. Also, the feasibility of using the sulfide produced in the UASB for copper precipitation in a second column was studied under continuous mode. The system presented here is an alternative to sulfidogenesis, particularly when it is necessary to avoid toxicity to sulfide and competition with methanogens. The bioreactor performed better with relatively low concentrations of sulfate (up to 1100 mg L(-1)) and COD/SO4(-2) ratios between 1.4 and 3.6. Under the continuous regime, the biogenic sulfide was sufficient to precipitate copper at a removal rate of 234 mg L(-1) day(-1). Finally, the identification of the microorganisms in the sludge was carried out; some genera of microorganisms identified were Desulfitobacterium and Clostridium.

  9. Antibacterial and hemolysis activity of polypyrrole nanotubes decorated with silver nanoparticles by an in-situ reduction process.

    PubMed

    Upadhyay, J; Kumar, A; Gogoi, B; Buragohain, A K

    2015-09-01

    Polypyrrole nanotube-silver nanoparticle nanocomposites (PPy-NTs:Ag-NPs) have been synthesized by in-situ reduction of silver nitrate (AgNO3) to suppress the agglomeration of Ag-NPs. The morphology and chemical structure of the nanocomposites have been studied by HRTEM, SEM, XRD, FTIR and UV-vis spectroscopy. The average diameter of the polypyrrole nanotubes (PPy-NTs) is measured to be 130.59±5.5 nm with their length in the micrometer range, while the silver nanoparticles (Ag-NPs) exhibit spherical shape with an average diameter of 23.12±3.23 nm. In-vitro blood compatibility of the nanocomposites has been carried out via hemolysis assay. Antimicrobial activity of the nanocomposites has been investigated with Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) bacteria. The results depict that the hemolysis and antimicrobial activities of the nanocomposites increase with increasing Ag-NP concentration that can be controlled by the AgNO3 precursor concentration in the in-situ process.

  10. Oxidative decolorization of methylene blue by leached sea-nodule residues generated by the reduction-roasting ammoniacal leaching process.

    PubMed

    Satapathy, P K; Randhawa, N S; Das, N N

    2012-01-01

    The leached residue, generated after selective extraction of Cu, Ni and Co by reductive-roasting ammoniacal leaching of sea nodules, was characterized by various physicochemical methods. The finely divided residue, containing mainly manganese carbonate/silicates and manganese (III, IV) (hydr)oxides along with iron oxides, showed a lower surface area (66.3 m2 g(-1)) than that of the parent sea nodule (130 m2 g(-1)). The catalytic efficiency of water-washed sea nodule residue (WSNR) was evaluated taking oxidative decolorization of methylene blue (MB) as the test reaction. The extent of decolorization was decreased with increase in pH but increased in the presence of H2O2 or NaCl. Decolorization of MB occurred in two consecutive steps; the rate constant of the first step was -10 times higher than that of the second step. The formation of a surface precursor complex between WSNR and MB at a rate-limiting step, followed by electron transfer from MB to the active metal centre of WSNR and release of product(s), was proposed as the decolorization process.

  11. Preparation of a carbon-based solid acid catalyst by sulfonating activated carbon in a chemical reduction process.

    PubMed

    Liu, Xiao-Yan; Huang, Miao; Ma, Hai-Long; Zhang, Zeng-Qiang; Gao, Jin-Ming; Zhu, Yu-Lei; Han, Xiao-Jin; Guo, Xiang-Yun

    2010-10-18

    Sulfonated (SO(3)H-bearing) activated carbon (AC-SO(3)H) was synthesized by an aryl diazonium salt reduction process. The obtained material had a SO(3)H density of 0.64 mmol·g-1 and a specific surface area of 602 m2·g-1. The catalytic properties of AC-SO(3)H were compared with that of two commercial solid acid catalysts, Nafion NR50 and Amberlyst-15. In a 10-h esterification reaction of acetic acid with ethanol, the acid conversion with AC-SO(3)H (78%) was lower than that of Amberlyst-15 (86%), which could be attributed to the fact that the SO(3)H density of the sulfonated carbon was lower than that of Amberlyst-15 (4.60 mmol·g-1). However, AC-SO(3)H exhibited comparable and even much higher catalytic activities than the commercial catalysts in the esterification of aliphatic acids with longer carbon chains such as hexanoic acid and decanoic acid, which may be due to the large specific surface area and mesoporous structures of the activated carbon. The disadvantage of AC-SO(3)H is the leaching of SO(3)H group during the reactions.

  12. Wet chemical synthesis of intermetallic Pt3Zn nanocrystals via weak reduction reaction together with UPD process and their excellent electrocatalytic performances.

    PubMed

    Chen, Qiaoli; Zhang, Jiawei; Jia, Yanyan; Jiang, Zhiyuan; Xie, Zhaoxiong; Zheng, Lansun

    2014-06-21

    Platinum based alloy nanocrystals are promising catalysts for a variety of important practical process. However, it remains a great challenge to synthesize platinum-based intermetallic compound nanocrystals with well-defined surface structures. In this communication, taking the synthesis of concave cubic intermetallic Pt3Zn nanocrystals with {hk0} facets as an example, we proposed a new synthesis strategy for intermetallic compounds by reduction of noble metal precursors via a slow reduction process and reduction of transition metal ions via an underpotential deposition (UPD) process in wet chemical synthesis. The as-prepared intermetallic Pt3Zn nanocrystals exhibited superior CO poisoning tolerance and high electro-catalytic activity in both methanol and formic acid oxidation reactions in comparison with solid solution Pt3Zn nanocrystals and Pt/C.

  13. Wet chemical synthesis of intermetallic Pt3Zn nanocrystals via weak reduction reaction together with UPD process and their excellent electrocatalytic performances

    NASA Astrophysics Data System (ADS)

    Chen, Qiaoli; Zhang, Jiawei; Jia, Yanyan; Jiang, Zhiyuan; Xie, Zhaoxiong; Zheng, Lansun

    2014-05-01

    Platinum based alloy nanocrystals are promising catalysts for a variety of important practical process. However, it remains a great challenge to synthesize platinum-based intermetallic compound nanocrystals with well-defined surface structures. In this communication, taking the synthesis of concave cubic intermetallic Pt3Zn nanocrystals with {hk0} facets as an example, we proposed a new synthesis strategy for intermetallic compounds by reduction of noble metal precursors via a slow reduction process and reduction of transition metal ions via an underpotential deposition (UPD) process in wet chemical synthesis. The as-prepared intermetallic Pt3Zn nanocrystals exhibited superior CO poisoning tolerance and high electro-catalytic activity in both methanol and formic acid oxidation reactions in comparison with solid solution Pt3Zn nanocrystals and Pt/C.Platinum based alloy nanocrystals are promising catalysts for a variety of important practical process. However, it remains a great challenge to synthesize platinum-based intermetallic compound nanocrystals with well-defined surface structures. In this communication, taking the synthesis of concave cubic intermetallic Pt3Zn nanocrystals with {hk0} facets as an example, we proposed a new synthesis strategy for intermetallic compounds by reduction of noble metal precursors via a slow reduction process and reduction of transition metal ions via an underpotential deposition (UPD) process in wet chemical synthesis. The as-prepared intermetallic Pt3Zn nanocrystals exhibited superior CO poisoning tolerance and high electro-catalytic activity in both methanol and formic acid oxidation reactions in comparison with solid solution Pt3Zn nanocrystals and Pt/C. Electronic supplementary information (ESI) available: Additional characterization data. See DOI: 10.1039/c4nr00313f

  14. Biogeochemical Processes Related to Metal Removal and Toxicity Reduction in the H-02 Constructed Wetland, Savannah River Site

    NASA Astrophysics Data System (ADS)

    Burgess, E. A.; Mills, G. L.; Harmon, M.; Samarkin, V.

    2011-12-01

    The H-02 wetland system was designed to treat building process water and storm water runoff from multiple sources associated with the Tritium Facility at the DOE-Savannah River Site, Aiken, SC. The wetland construction included the addition of gypsum (calcium sulfate) to foster a sulfate-reducing bacterial population. Conceptually, the wetland functions as follows: ? Cu and Zn initially bind to both dissolved and particulate organic detritus within the wetland. ? A portion of this organic matter is subsequently deposited into the surface sediments within the wetland. ? The fraction of Cu and Zn that is discharged in the wetland effluent is organically complexed, less bioavailable, and consequently, less toxic. ? The Cu and Zn deposited in the surface sediments are eventually sequestered into insoluble sulfide minerals in the wetland. Development of the H-02 system has been closely monitored; sampling began in August 2007, shortly after its construction. This monitoring has included the measurement of water quality parameters, Cu and Zn concentrations in surface water and sediments, as well as, characterization of the prokaryotic (e.g., bacterial) component of wetland biogeochemical processes. Since the beginning of the study, the mean influent Cu concentration was 31.5±12.1 ppb and the mean effluent concentration was 11.9±7.3 ppb, corresponding to an average Cu removal of 64%. Zn concentrations were more variable, averaging 39.2±13.8 ppb in the influent and 25.7±21.3 ppb in the effluent. Average Zn removal was 52%. The wetland also ameliorated high pH values associated with influent water to values similar to those measured at reference sites. Seasonal variations in DOC concentration corresponded to seasonal variations in Cu and Zn removal efficiency. The concentration of Cu and Zn in the surface layer of the sediments has increased over the lifetime of the wetland and, like removal efficiency, demonstrated seasonal variation. Within its first year, the H-02

  15. BACKGROUND TRACK DENSITY REDUCTION OF 50-HZ-HV ECE-PROCESSED THICK POLYCARBONATE DETECTORS TO IMPROVE LOWER DETECTION LIMIT.

    PubMed

    Sohrabi, M; Hakimi, A; Soltani, Z

    2016-12-01

    A recent novel development of 50-Hz-HV ECE of 1-mm-thick and 250-µm-thick polycarbonate track detectors (PCTDs) has proved some promising results for some health physics, dosimetry and ion-beam-related applications. The method while proved having some good characteristics for some applications provided a relatively higher background track density (BGTD) in particular when very high voltages are applied to the PCTDs. In order to decrease the minimum detection limit (MDL) of the PCTDs and to further promote its applications for low dose, the BGTD was reduced by applying a layer removal methodology applying ethylendiamine (EDA). The effects of EDA concentrations (50, 60, 65, 70, 75, 80, 85 and 90 %) in water at room temperature (26°C) and soaking durations up to 100 min at different EDA concentration on BGTD reduction were studied. The thickness of the layer removed from the surface of a PCTD highly depends on the soaking time and EDA concentration; it increases as the EDA concentration increases up to for example 700 µm after 2 h of soaking in the EDA solution. After ∼10 min of soaking duration at any of the above-stated concentrations, the BGTD reaches its minimum value, a value which differs from concentration to concentration. An EDA concentration of 85 % in water provided the lowest BGTD of 64.06 ± 3.12 tracks cm(- 2); ∼6 times lower than that of its original value. It is shown that the layer removal process does not change the registration characteristics of the PCTD and its appearance significantly. The MDL of the PCTDs depends strongly on the BGTD. The MDL values for a desired confidence level were also studied by three calculation methods. The results of the BGTD and the MDL studies under different conditions applied are presented and discussed.

  16. Reduction-melting combined with a Na₂CO₃ flux recycling process for lead recovery from cathode ray tube funnel glass.

    PubMed

    Okada, Takashi; Yonezawa, Susumu

    2014-08-01

    With large quantity of flux (Na2CO3), lead can be recovered from the funnel glass of waste cathode-ray tubes via reduction-melting at 1000°C. To reduce flux cost, a technique to recover added flux from the generated oxide phase is also important in order to recycle the flux recovered from the reduction-melting process. In this study, the phase separation of sodium and the crystallization of water-soluble sodium silicates were induced after the reduction-melting process to enhance the leachability of sodium in the oxide phase and to extract the sodium from the phase for the recovery of Na2CO3 as flux. A reductive atmosphere promoted the phase separation and crystallization, and the leachability of sodium from the oxide phase was enhanced. The optimum temperature and treatment time for increasing the leachability were 700°C and 2h, respectively. After treatment, more than 90% of the sodium in the oxide phase was extracted in water. NaHCO3 can be recovered by carbonization of the solution containing sodium ions using carbon dioxide gas, decomposed to Na2CO3 at 50°C and recycled for use in the reduction-melting process.

  17. Enhanced magnetic properties of NiO powders by the mechanical activation of aluminothermic reduction of NiO prepared by a ball milling process

    NASA Astrophysics Data System (ADS)

    Padhan, Aneeta Manjari; Ravikumar, P.; Saravanan, P.; Alagarsamy, Perumal

    2016-11-01

    We report the effect of mechanical activation on NiO-Al (x wt%) reduction reaction and resulting structural and magnetic properties by carrying out high-energy planetary ball milling. The pure NiO (un-milled) and milled NiO-Al (x≤2.5) powders exhibit face centered cubic structure, but the antiferromagnetic nature of pure NiO powder shows significant room temperature ferromagnetism with moderate moment and coercivity after milling due to non-stoichiometry in NiO caused by the defects, size reduction and oxidation of Ni. On the other hand, the addition of Al between 2.5 and 10% in NiO forms solid solution of NiO-Al with considerable reduction in the moment due to the atomic disorder. With increasing Al above 10%, NiO reduction reaction progresses gradually and as a result, the average magnetization increases from 0.57 to 4.3 emu/g with increasing Al up to 25%. A maximum of 91% reduction was observed for NiO-Al (40%) powders in 30 h of milling with a large increase in magnetization (~24 emu/g) along with the development of α-Al2O3. Thermomagnetization data reveal the presence of mixed magnetic phases in milled NiO powders and the component of induced ferromagnetic phase fades out with increasing Al due to the formation of Ni from the NiO-Al reduction reaction. The changes in the structural and magnetic properties are discussed on the basis of mechanical activation on the reduction of NiO by Al. The controlled reduction reaction with different Al content in NiO-Al is encouraging for the applications in catalysis and process of ore reduction.

  18. Whole-leaf wash improves chlorine efficacy for microbial reduction and prevents pathogen cross-contamination during fresh-cut lettuce processing.

    PubMed

    Nou, Xiangwu; Luo, Yaguang

    2010-06-01

    Currently, most fresh-cut processing facilities in the United States use chlorinated water or other sanitizer solutions for microbial reduction after lettuce is cut. Freshly cut lettuce releases significant amounts of organic matter that negatively impacts the effectiveness of chlorine or other sanitizers for microbial reduction. The objective of this study is to evaluate whether a sanitizer wash before cutting improves microbial reduction efficacy compared to a traditional postcutting sanitizer wash. Romaine lettuce leaves were quantitatively inoculated with E. coli O157:H7 strains and washed in chlorinated water before or after cutting, and E. coli O157:H7 cells that survived the washing process were enumerated to determine the effectiveness of microbial reduction for the 2 cutting and washing sequences. Whole-leaf washing in chlorinated water improved pathogen reduction by approximately 1 log unit over traditional cut-leaf sanitization. Similar improvement in the reduction of background microflora was also observed. Inoculated "Lollo Rossa" red lettuce leaves were mixed with noninoculated Green-Leaf lettuce leaves to evaluate pathogen cross-contamination during processing. High level (96.7% subsamples, average MPN 0.6 log CFU/g) of cross-contamination of noninoculated green leaves by inoculated red leaves was observed when mixed lettuce leaves were cut prior to washing in chlorinated water. In contrast, cross-contamination of noninoculated green leaves was significantly reduced (3.3% of subsamples, average MPN reduction and cross-contamination prevention.

  19. TREATMENT OF HEXAVALENT CHROMIUM IN CHROMITE ORE PROCESSING SOLID WASTE USING A MIXED REDUCTANT SOLUTION OF FERROUS SULFATE AND SODIUM DITHIONITE

    EPA Science Inventory

    We developed a method for disseminating ferrous iron in the subsurface to enhance chemical reduction of hexavalent chromium (Cr(VI)) in a chromite ore processing solid waste derived from the production of ferrochrome alloy. The method utilizes ferrous sulfate (FeSO4) in combinati...

  20. Core flooding tests to investigate the effects of IFT reduction and wettability alteration on oil recovery during MEOR process in an Iranian oil reservoir.

    PubMed

    Rabiei, Arash; Sharifinik, Milad; Niazi, Ali; Hashemi, Abdolnabi; Ayatollahi, Shahab

    2013-07-01

    Microbial enhanced oil recovery (MEOR) refers to the process of using bacterial activities for more oil recovery from oil reservoirs mainly by interfacial tension reduction and wettability alteration mechanisms. Investigating the impact of these two mechanisms on enhanced oil recovery during MEOR process is the main objective of this work. Different analytical methods such as oil spreading and surface activity measurements were utilized to screen the biosurfactant-producing bacteria isolated from the brine of a specific oil reservoir located in the southwest of Iran. The isolates identified by 16S rDNA and biochemical analysis as Enterobacter cloacae (Persian Type Culture Collection (PTCC) 1798) and Enterobacter hormaechei (PTCC 1799) produce 1.53 g/l of biosurfactant. The produced biosurfactant caused substantial surface tension reduction of the growth medium and interfacial tension reduction between oil and brine to 31 and 3.2 mN/m from the original value of 72 and 29 mN/m, respectively. A novel set of core flooding tests, including in situ and ex situ scenarios, was designed to explore the potential of the isolated consortium as an agent for MEOR process. Besides, the individual effects of wettability alteration and IFT reduction on oil recovery efficiency by this process were investigated. The results show that the wettability alteration of the reservoir rock toward neutrally wet condition in the course of the adsorption of bacteria cells and biofilm formation are the dominant mechanisms on the improvement of oil recovery efficiency.

  1. Implementation of a Community-Based Secondhand Smoke Reduction Intervention for Caregivers of Urban Children with Asthma: Process Evaluation, Successes and Challenges

    ERIC Educational Resources Information Center

    Blaakman, Susan; Tremblay, Paul J.; Halterman, Jill S.; Fagnano, Maria; Borrelli, Belinda

    2013-01-01

    Many children, including those with asthma, remain exposed to secondhand smoke. This manuscript evaluates the process of implementing a secondhand smoke reduction counseling intervention using motivational interviewing (MI) for caregivers of urban children with asthma, including reach, dose delivered, dose received and fidelity. Challenges,…

  2. An improved stereoselective reduction of a bicyclic diketone by Saccharomyces cerevisiae combining process optimization and strain engineering.

    PubMed

    Katz, M; Sarvary, I; Frejd, T; Hahn-Hägerdal, B; Gorwa-Grauslund, M F

    2002-09-01

    The stereoselective reduction of the bicyclic diketone bicyclo[2.2.2]octane-2,6-dione, to the ketoalcohol (1R,4S,6S)-6-hydroxybicyclo[2.2.2]octane-2-one, was used as a model reduction to optimize parameters involved in NADPH-dependent reductions in Saccharomyces cerevisiae with glucose as co-substrate. The co-substrate yield (ketoalcohol formed/glucose consumed) was affected by the initial concentration of bicyclic diketone, the ratio of yeast to glucose, the medium composition, and the pH. The reduction of 5 g l(-1) bicyclic diketone was completed in less than 20 h in complex medium (pH 5.5) under oxygen limitation with an initial concentration of 200 g l(-1) glucose and 5 g l(-1) yeast. The co-substrate yield was further enhanced by genetically engineered strains with reduced phosphoglucose isomerase activity and with the gene encoding alcohol dehydrogenase deleted. Co-substrate yields were increased 2.3-fold and 2.4-fold, respectively, in these strains.

  3. Pretreatment of 2,4-dinitroanisole (DNAN) producing wastewater using a combined zero-valent iron (ZVI) reduction and Fenton oxidation process.

    PubMed

    Shen, Jinyou; Ou, Changjin; Zhou, Zongyuan; Chen, Jun; Fang, Kexiong; Sun, Xiuyun; Li, Jiansheng; Zhou, Lin; Wang, Lianjun

    2013-09-15

    A combined zero-valent iron (ZVI) reduction and Fenton oxidation process was tested for the pretreatment of 2,4-dinitroanisole (DNAN) producing wastewater. Operating conditions were optimized and overall performance of the combined process was evaluated. For ZVI process, almost complete reduction of nitroaromatic compounds was observed at empty bed contact time (EBCT) of 8h. For Fenton process, the optimal pH, H₂O₂ to Fe(II) molar ratio, H₂O₂ dosage and hydraulic retention time (HRT) were found to be 3.0, 15, 0.216 mol/L and 5h, respectively. After pretreatment by the combined ZVI-Fenton process under the optimal conditions, aromatic organic compound removal was as high as 77.2%, while the majority of COD remained to be further treated by sequent biological process. The combined anaerobic-aerobic process consisted of an anaerobic baffled reactor (ABR) and a moving-bed biofilm reactor (MBBR) was operated for 3 months, fed with ZVI-Fenton effluent. The results revealed that the coupled ZVI-Fenton-ABR-MBBR system was significantly efficient in terms of correcting the effluent's main parameters of relevance, mainly aromatic compounds concentration, COD concentration, color and acute toxicity. These results indicate that the combined ZVI-Fenton process offers bright prospects for the pretreatment of wastewater containing nitroaromatic compounds.

  4. The involvement of ATP sulfurylase in Se(VI) and Cr(VI) reduction processes in the fission yeast Schizosaccharomyces pombe.

    PubMed

    Raspor, P; Fujs, S; Banszky, L; Maraz, A; Batic, M

    2003-11-01

    The response of Schizosaccharomyces pombe towards the oxyanions selenate [Se(VI)] and dichromate [Cr(VI)] was investigated in order to establish the involvement of the yeast ATP sulfurylase in their reduction. An ATP sulfurylase-defective/selenate-resistant mutant of S. pombe (B-579 Se(R) -2) and an ATP sulfurylase-active/selenate-sensitive strain of S. pombe (B-579 Se(S)) were included in this study. The inhibitory effect of Se(VI) and Cr(VI) oxyanions on growth and bioaccumulation was measured. The sensitive strain showed natural sensitivity to selenate while the resistant mutant tolerated a 100-fold higher concentration of selenate. These results indicate that selenate toxicity to microorganisms is connected with the reduction of selenate to selenite. Both strains showed similar sensitivity to Cr(VI) and in this study there was no evidence that ATP sulfurylase participates in the reduction process of Cr(VI).

  5. THE SECOND GENERATION OF THE WASTE REDUCTION (WAR) ALGORITHM: A DECISION SUPPORT SYSTEM FOR GREENER CHEMICAL PROCESSES

    EPA Science Inventory

    chemical process designers using simulation software generate alternative designs for one process. One criterion for evaluating these designs is their potential for adverse environmental impacts due to waste generated, energy consumed, and possibilities for fugitive emissions. Co...

  6. Evaluation Of In Situ Steam-Injection Processes For Reduction Of Petroleum Compounds Within An Abandoned Canal

    EPA Science Inventory

    A conceptual approach of a novel application of in-situ thermal processes that would either use a steam injection process or a steam/surfactant injection process was considered to remediate petroleum contaminated sediment residing in an abandoned canal. Laboratory tests were c...

  7. New Applications of Gamma Spectroscopy: Characterization Tools for D&D Process Development, Inventory Reduction Planning & Shipping, Safety Analysis & Facility Management During the Heavy Element Facility Risk Reduction Program

    SciTech Connect

    Mitchell, M; Anderson, B; Gray, L; Vellinger, R; West, M; Gaylord, R; Larson, J; Jones, G; Shingleton, J; Harris, L; Harward, N

    2006-01-23

    Novel applications of gamma ray spectroscopy for D&D process development, inventory reduction, safety analysis and facility management are discussed in this paper. These applications of gamma spectroscopy were developed and implemented during the Risk Reduction Program (RPP) to successfully downgrade the Heavy Element Facility (B251) at Lawrence Livermore National Laboratory (LLNL) from a Category II Nuclear Facility to a Radiological Facility. Non-destructive assay in general, gamma spectroscopy in particular, were found to be important tools in project management, work planning, and work control (''Expect the unexpected and confirm the expected''), minimizing worker dose, and resulted in significant safety improvements and operational efficiencies. Inventory reduction activities utilized gamma spectroscopy to identify and confirm isotopics of legacy inventory, ingrowth of daughter products and the presence of process impurities; quantify inventory; prioritize work activities for project management; and to supply information to satisfy shipper/receiver documentation requirements. D&D activities utilize in-situ gamma spectroscopy to identify and confirm isotopics of legacy contamination; quantify contamination levels and monitor the progress of decontamination efforts; and determine the point of diminishing returns in decontaminating enclosures and glove boxes containing high specific activity isotopes such as {sup 244}Cm and {sup 238}Pu. In-situ gamma spectroscopy provided quantitative comparisons of several decontamination techniques (e.g. TLC-free Stripcoat{trademark}, Radiac{trademark} wash, acid wash, scrubbing) and was used as a part of an iterative process to determine the appropriate level of decontamination and optimal cost to benefit ratio. Facility management followed a formal, rigorous process utilizing an independent, state certified, peer-reviewed gamma spectroscopy program, in conjunction with other characterization techniques, process knowledge, and

  8. Revising the role of pH and thermal treatments in aflatoxin content reduction during the tortilla and deep frying processes.

    PubMed

    Torres, P; Guzmán-Ortiz, M; Ramírez-Wong, B

    2001-06-01

    Naturally aflatoxin-contaminated corn (Zea mays L.) was made into tortillas, tortilla chips, and corn chips by the traditional and commercial alkaline cooking processes. The traditional nixtamalization (alkaline-cooking) process involved cooking and steeping the corn, whereas the commercial nixtamalization process only steeps the corn in a hot alkaline solution (initially boiling). A pilot plant that includes the cooker, stone grinder, celorio cutter, and oven was used for the experiments. The traditional process eliminated 51.7, 84.5, and 78.8% of the aflatoxins content in tortilla, tortilla chips, and corn chips, respectively. The commercial process was less effective: it removed 29.5, 71.2, and 71.2 of the aflatoxin in the same products. Intermediate and final products did not reach a high enough pH to allow permanent aflatoxin reduction during thermal processing. The cooking or steeping liquor (nejayote) is the only component of the system with a sufficiently high pH (10.2-10.7) to allow modification and detoxification of aflatoxins present in the corn grain. The importance of removal of tip, pericarp, and germ during nixtamalization for aflatoxin reduction in tortilla is evident.

  9. Modes of Large-Scale Brain Network Organization during Threat Processing and Posttraumatic Stress Disorder Symptom Reduction during TF-CBT among Adolescent Girls

    PubMed Central

    Cisler, Josh M.; Sigel, Benjamin A.; Kramer, Teresa L.; Smitherman, Sonet; Vanderzee, Karin; Pemberton, Joy; Kilts, Clinton D.

    2016-01-01

    Posttraumatic stress disorder (PTSD) is often chronic and disabling across the lifespan. The gold standard treatment for adolescent PTSD is Trauma-Focused Cognitive-Behavioral Therapy (TF-CBT), though treatment response is variable and mediating neural mechanisms are not well understood. Here, we test whether PTSD symptom reduction during TF-CBT is associated with individual differences in large-scale brain network organization during emotion processing. Twenty adolescent girls, aged 11–16, with PTSD related to assaultive violence completed a 12-session protocol of TF-CBT. Participants completed an emotion processing task, in which neutral and fearful facial expressions were presented either overtly or covertly during 3T fMRI, before and after treatment. Analyses focused on characterizing network properties of modularity, assortativity, and global efficiency within an 824 region-of-interest brain parcellation separately during each of the task blocks using weighted functional connectivity matrices. We similarly analyzed an existing dataset of healthy adolescent girls undergoing an identical emotion processing task to characterize normative network organization. Pre-treatment individual differences in modularity, assortativity, and global efficiency during covert fear vs neutral blocks predicted PTSD symptom reduction. Patients who responded better to treatment had greater network modularity and assortativity but lesser efficiency, a pattern that closely resembled the control participants. At a group level, greater symptom reduction was associated with greater pre-to-post-treatment increases in network assortativity and modularity, but this was more pronounced among participants with less symptom improvement. The results support the hypothesis that modularized and resilient brain organization during emotion processing operate as mechanisms enabling symptom reduction during TF-CBT. PMID:27505076

  10. Evaluation of virus reduction efficiency in wastewater treatment unit processes as a credit value in the multiple-barrier system for wastewater reclamation and reuse.

    PubMed

    Ito, Toshihiro; Kato, Tsuyoshi; Hasegawa, Makoto; Katayama, Hiroyuki; Ishii, Satoshi; Okabe, Satoshi; Sano, Daisuke

    2016-12-01

    The virus reduction efficiency of each unit process is commonly determined based on the ratio of virus concentration in influent to that in effluent of a unit, but the virus concentration in wastewater has often fallen below the analytical quantification limit, which does not allow us to calculate the concentration ratio at each sampling event. In this study, left-censored datasets of norovirus (genogroup I and II), and adenovirus were used to calculate the virus reduction efficiency in unit processes of secondary biological treatment and chlorine disinfection. Virus concentration in influent, effluent from the secondary treatment, and chlorine-disinfected effluent of four municipal wastewater treatment plants were analyzed by a quantitative polymerase chain reaction (PCR) approach, and the probabilistic distributions of log reduction (LR) were estimated by a Bayesian estimation algorithm. The mean values of LR in the secondary treatment units ranged from 0.9 and 2.2, whereas those in the free chlorine disinfection units were from -0.1 and 0.5. The LR value in the secondary treatment was virus type and unit process dependent, which raised the importance for accumulating the data of virus LR values applicable to the multiple-barrier system, which is a global concept of microbial risk management in wastewater reclamation and reuse.

  11. Application of hybrid coal reburning/SNCR processes for NOx reduction in a coal-fired boiler

    SciTech Connect

    Yang, W.J.; Zhou, Z.J.; Zhou, J.H.; Hongkun, L.V.; Liu, J.Z.; Cen, K.F.

    2009-07-01

    Boilers in Beijing Thermal Power Plant of Zhongdian Guohua Co. in China are coal-fired with natural circulation and tangential fired method, and the economical continuous rate is 410 ton per hour of steam. Hybrid coal reburning/SNCR technology was applied and it successfully reduced NOx to about 170 mg/Nm{sup 3} from about 540 mg/Nm{sup 3}, meanwhile ammonia slip was lower than 10 ppm at 450-210 t/h load and the total reduction efficiency was about 70%. Normal fineness pulverized coal from the bin was chosen as the reburning fuel and the nozzles of the upper primary air were retrofitted to be used as the reburning fuel nozzles. The reducing agent of SNCR was an urea solution, and it was injected by the four layer injectors after online dilution. At 410 t/h load, NOx emission was about 300 mg/Nm{sup 3} when the ratio of reburning fuel to the total fuel was 25.9%-33.4%. Controlling the oxygen content of the gas in the reversal chamber to less than 3.4% resulted in not only low NOx emission but also high combustion efficiency. Ammonia slip distribution in the down gas pass was uneven and ammonia slip was higher in the front of the down gas pass than in the rear of the down gas pass. NSR and NOx reduction were proportional to each other and usually resulted in more ammonia slip with reduction in NOx. About 100 mg/Nm{sup 3} NOx emission could be achieved with about 40 ppm NH{sub 3} slip at 300-450 t/h, and ammonia slip from the SNCR reactions could be used as reducing agent of SCR, which was favorable for the future SCR retrofit.

  12. Flow processes in overexpanded chemical rocket nozzles. Part 3: Methods for the aimed flow separation and side load reduction

    NASA Technical Reports Server (NTRS)

    Schmucker, R. H.

    1983-01-01

    Methods aimed at reduction of overexpansion and side load resulting from asymmetric flow separation for rocket nozzles with a high opening ratio are described. The methods employ additional measures for nozzles with a fixed opening ratio. The flow separation can be controlled by several types of nozzle inserts, the properties of which are discussed. Side loads and overexpansion can be reduced by adapting the shape of the nozzle and taking other additional measures for controlled separation of the boundary layer, such as trip wires.

  13. Selective catalytic reduction system and process for control of NO.sub.x emissions in a sulfur-containing gas stream

    DOEpatents

    Sobolevskiy, Anatoly

    2015-08-11

    An exhaust gas treatment process, apparatus, and system for reducing the concentration of NOx, CO and hydrocarbons in a gas stream, such as an exhaust stream (29), via selective catalytic reduction with ammonia is provided. The process, apparatus and system include a catalytic bed (32) having a reducing only catalyst portion (34) and a downstream reducing-plus-oxidizing portion (36). Each portion (34, 36) includes an amount of tungsten. The reducing-plus-oxidizing catalyst portion (36) advantageously includes a greater amount of tungsten than the reducing catalyst portion (36) to markedly limit ammonia salt formation.

  14. Characteristics and kinetic analysis of AQS transformation and microbial goethite reduction: Insight into “redox mediator-microbe-iron oxide” interaction process

    DOE PAGES

    Zhu, Weihuang; Shi, Mengran; Yu, Dan; ...

    2016-03-29

    Here, the characteristics and kinetics of redox transformation of a redox mediator, anthraquinone-2-sulfonate (AQS), during microbial goethite reduction by Shewanella decolorationis S12, a dissimilatory iron reduction bacterium (DIRB), were investigated to provide insights into “redox mediator-iron oxide” interaction in the presence of DIRB. Two pre-incubation reaction systems of the “strain S12-goethite” and the “strain S12-AQS” were used to investigate the dynamics of goethite reduction and AQS redox transformation. Results show that the concentrations of goethite and redox mediator, and the inoculation cell density all affect the characteristics of microbial goethite reduction, kinetic transformation between oxidized and reduced species of themore » redox mediator. Both abiotic and biotic reactions and their coupling regulate the kinetic process for “Quinone-Iron” interaction in the presence of DIRB. Our results provide some new insights into the characteristics and mechanisms of interaction among “quinone-DIRB- goethite” under biotic/abiotic driven.« less

  15. Characteristics and kinetic analysis of AQS transformation and microbial goethite reduction: Insight into “redox mediator-microbe-iron oxide” interaction process

    SciTech Connect

    Zhu, Weihuang; Shi, Mengran; Yu, Dan; Liu, Chongxuan; Huang, Tinglin; Wu, Fengchang

    2016-03-29

    Here, the characteristics and kinetics of redox transformation of a redox mediator, anthraquinone-2-sulfonate (AQS), during microbial goethite reduction by Shewanella decolorationis S12, a dissimilatory iron reduction bacterium (DIRB), were investigated to provide insights into “redox mediator-iron oxide” interaction in the presence of DIRB. Two pre-incubation reaction systems of the “strain S12-goethite” and the “strain S12-AQS” were used to investigate the dynamics of goethite reduction and AQS redox transformation. Results show that the concentrations of goethite and redox mediator, and the inoculation cell density all affect the characteristics of microbial goethite reduction, kinetic transformation between oxidized and reduced species of the redox mediator. Both abiotic and biotic reactions and their coupling regulate the kinetic process for “Quinone-Iron” interaction in the presence of DIRB. Our results provide some new insights into the characteristics and mechanisms of interaction among “quinone-DIRB- goethite” under biotic/abiotic driven.

  16. DOWNSTREAM IMPACTS OF SLUDGE MASS REDUCTION VIA ALUMINUM DISSOLUTION ON DWPF PROCESSING OF SAVANNAH RIVER SITE HIGH LEVEL WASTE - 9382

    SciTech Connect

    Pareizs, J; Cj Bannochie, C; Michael Hay, M; Daniel McCabe, D

    2009-01-14

    The SRS sludge that was to become a major fraction of Sludge Batch 5 (SB5) for the Defense Waste Processing Facility (DWPF) contained a large fraction of H-Modified PUREX (HM) sludge, containing a large fraction of aluminum compounds that could adversely impact the processing and increase the vitrified waste volume. It is beneficial to reduce the non-radioactive fraction of the sludge to minimize the number of glass waste canisters that must be sent to a Federal Repository. Removal of aluminum compounds, such as boehmite and gibbsite, from sludge can be performed with the addition of NaOH solution and heating the sludge for several days. Preparation of SB5 involved adding sodium hydroxide directly to the waste tank and heating the contents to a moderate temperature through slurry pump operation to remove a fraction of this aluminum. The Savannah River National Laboratory (SRNL) was tasked with demonstrating this process on actual tank waste sludge in our Shielded Cells Facility. This paper evaluates some of the impacts of aluminum dissolution on sludge washing and DWPF processing by comparing sludge processing with and without aluminum dissolution. It was necessary to demonstrate these steps to ensure that the aluminum removal process would not adversely impact the chemical and physical properties of the sludge which could result in slower processing or process upsets in the DWPF.

  17. Postharvest Reduction of Coliphage MS2 from Romaine Lettuce during Simulated Commercial Processing with and without a Chlorine-Based Sanitizer.

    PubMed

    Wengert, Samantha L; Aw, Tiong Gim; Ryser, Elliot T; Rose, Joan B

    2017-02-01

    Viral foodborne outbreaks are a serious threat to public health, and fresh produce is becoming increasingly recognized as a transmission vehicle. To limit foodborne disease, ready-to-eat leafy greens are typically washed with a chlorine-based sanitizer during commercial production. This study assessed the efficacy of a chlorine-based sanitizer against coliphage MS2, as a potential surrogate for foodborne viruses, on fresh-cut romaine lettuce during simulated commercial production using a small-scale processing line. Before processing, romaine lettuce was inoculated to contain approximately 10(5) and 10(6) PFU/g of MS2 for experiments with and without sanitizer, respectively. Lettuce samples were collected following each stage of processing, which included mechanical shredding, 2 min of flume washing (with or without 25 ppm of free chlorine), shaker table dewatering, and centrifugal drying. In addition, the spent centrifuge water and flume wash water were collected, with the flume water concentrated using hollow-fiber ultrafiltration. MS2 was recovered from lettuce in Tris-glycine buffer and quantified as PFUs in a double-agar overlay assay. The greatest reduction in MS2 occurred between shredding and flume washing, with levels remaining relatively stable following flume washing with or without 25 ppm of free chlorine. Average total reductions of 0.8 and 1.0 log PFU/g were seen after processing with and without the sanitizer, respectively, with no statistical difference observed between the two treatments (P > 0.05). The average MS2 level in the spent centrifugation water started at 4.0 log PFU/ml for experiments with sanitizer and the average MS2 reduction in the flume wash water was 4 log (PFU) for experiments with sanitizer, demonstrating that removals could be achieved in the water itself. These findings suggest that the currently recommended commercial production practices are unable to effectively decrease viruses once they have attached to leafy greens during

  18. Preparation of Mn-Based Selective Catalytic Reduction Catalysts by Three Methods and Optimization of Process Conditions

    PubMed Central

    Xing, Yi; Hong, Chen; Cheng, Bei; Zhang, Kun

    2013-01-01

    Mn-based catalysts enable high NOx conversion in the selective catalytic reduction of NOx with NH3. Three catalyst-production methods, namely, co-precipitation, impregnation, and sol-gel, were used in this study to determine the optimum method and parameters. The maximum catalytic activity was found for the catalyst prepared by sol-gel with a 0.5 Mn/Ti ratio. The denitrification efficiency using this catalyst was >90%, which was higher than those of catalysts prepared by the two other methods. The critical temperature of catalytic activity was 353 K. The optimum manganese acetate concentration and weathering time were 0.10 mol and 24 h, respectively. The gas hourly space velocity and O2 concentration were determined to be 12000 h-1 and 3%, respectively. PMID:24023841

  19. Reduction of Tantalum Pentoxide Using Graphite and Tin-Oxide-Based Anodes via the FFC-Cambridge Process

    NASA Astrophysics Data System (ADS)

    Barnett, Roger; Kilby, Kamal Tripuraneni; Fray, Derek J.

    2009-04-01

    An investigation into the electrochemical reduction of tantalum pentoxide (Ta2O5) to tantalum metal in molten calcium chloride was performed. The oxide was made the cathode, and either graphite or tin oxide rods were selected as the anodes. The experiments were terminated after 8 hours of potentiostatic electrolysis using a two-electrode setup, with the current and anodic potential recorded. The cathode products were analyzed by means of X-ray diffraction, scanning electron microscopy (SEM), and inert-gas fusion analysis. The key result is that tantalum can be produced using either anode, but the tin oxide anode leads to greater current efficiency and a cleaner melt with no significant differences in the product microstructure.

  20. Synthesis of copper-core/carbon-sheath nanocables by a surfactant-assisted hydrothermal reduction/carbonization process.

    PubMed

    Deng, Bin; Xu, An-Wu; Chen, Guang-Yi; Song, Rui-Qi; Chen, Liuping

    2006-06-22

    A simple hydrothermal method has been developed for the one-step synthesis of copper-core/carbon-sheath nanocables in solution. The obtained nanostructures were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and high-resolution TEM (HRTEM), Raman, and UV-vis spectrum analysis. These copper@carbon nanocables formed through the hydrothermal reduction/carbonization in the presence of surfactant cetyltrimethylammonium bromide (CTAB) acting as the structure-directing agent by hydrothermal treatment. HRTEM and selected-area electron diffraction (SAED) indicate that the resulted Cu nanowires had the preferred [110] growth direction. The influence of the reaction temperature, reaction time, and pH on the final products was investigated in detail. The possible formation mechanism for copper-core/carbon-sheath nanocables was also proposed. Amorphous carbon nanotubes can be obtained by etching the copper core in the nanocables.

  1. Facile synthesis of reduced graphene oxide nanosheets by a sodium diphenylamine sulfonate reduction process and its electrochemical property.

    PubMed

    Ji, Yunzhou; Liu, Qi; Cheng, Meiling; Lai, Lifang; Li, Zhanfeng; Peng, Yuxin; Yang, Yong

    2013-10-01

    We report a new method to convert graphene oxide (GO) to stable colloidal dispersion of reduced graphene oxide nanosheets (RGONS) using sodium diphenylamine sulfonate (SDAS) as a reductant, as well as itself and its redox product as the stabilizer. The as-prepared RGONS have been characterized by X-ray diffraction, Fourier transform infrared spectroscopy, UV-visible spectroscopy, thermo-gravimetric analysis, scanning and transmission electron microscopy, X-ray photoelectron spectroscopy, atomic force microscopy and Raman spectroscopy. The results indicate that the bulk of oxygen-containing functional groups from GO have been removed. Based on the cyclic voltammogram (CV) analyses, it is found that the RGONS-based material exhibits better electrochemical activity in sensing ascorbic acid than GO. The simple method provides a new efficient route for the synthesis of water-soluble RGONS on a large scale and novel composites.

  2. Pilot-scale test of an advanced, integrated wastewater treatment process with sludge reduction, inorganic solids separation, phosphorus recovery, and enhanced nutrient removal (SIPER).

    PubMed

    Yan, Peng; Ji, Fangying; Wang, Jing; Fan, Jianping; Guan, Wei; Chen, Qingkong

    2013-08-01

    Sludge reduction technologies are increasingly important in wastewater treatment, but have some defects. In order to remedy them, a novel, integrated process including sludge reduction, inorganic solids separation, phosphorus recovery, and enhanced nutrient removal was developed. The pilot-scale system was operated steadily at a treatment scale of 10 m(3)/d for 90 days. The results showed excellent nutrient removal, with average removal efficiencies for NH4(+)-N, TN, TP, and COD reaching 98.2 ± 1.34%, 75.5 ± 3.46%, 95.3 ± 1.65%, and 92.7 ± 2.49%, respectively. The ratio of mixed liquor volatile suspended solids (MLVSS) to mixed liquor suspended solids (MLSS) in the system gradually increased, from 0.33 to 0.52. The process effectively prevented the accumulation of inert or inorganic solids in activated sludge. Phosphorus was recovered as a crystalline product with aluminum ion from wastewater. The observed sludge yield Yobs of the system was 0.103 gVSS/g COD, demonstrating that the system's sludge reduction potential is excellent.

  3. Reduction in Hospital-Wide Clinical Laboratory Specimen Identification Errors following Process Interventions: A 10-Year Retrospective Observational Study

    PubMed Central

    Ning, Hsiao-Chen; Lin, Chia-Ni; Chiu, Daniel Tsun-Yee; Chang, Yung-Ta; Wen, Chiao-Ni; Peng, Shu-Yu; Chu, Tsung-Lan; Yu, Hsin-Ming; Wu, Tsu-Lan

    2016-01-01

    Background Accurate patient identification and specimen labeling at the time of collection are crucial steps in the prevention of medical errors, thereby improving patient safety. Methods All patient specimen identification errors that occurred in the outpatient department (OPD), emergency department (ED), and inpatient department (IPD) of a 3,800-bed academic medical center in Taiwan were documented and analyzed retrospectively from 2005 to 2014. To reduce such errors, the following series of strategies were implemented: a restrictive specimen acceptance policy for the ED and IPD in 2006; a computer-assisted barcode positive patient identification system for the ED and IPD in 2007 and 2010, and automated sample labeling combined with electronic identification systems introduced to the OPD in 2009. Results Of the 2000345 specimens collected in 2005, 1023 (0.0511%) were identified as having patient identification errors, compared with 58 errors (0.0015%) among 3761238 specimens collected in 2014, after serial interventions; this represents a 97% relative reduction. The total number (rate) of institutional identification errors contributed from the ED, IPD, and OPD over a 10-year period were 423 (0.1058%), 556 (0.0587%), and 44 (0.0067%) errors before the interventions, and 3 (0.0007%), 52 (0.0045%) and 3 (0.0001%) after interventions, representing relative 99%, 92% and 98% reductions, respectively. Conclusions Accurate patient identification is a challenge of patient safety in different health settings. The data collected in our study indicate that a restrictive specimen acceptance policy, computer-generated positive identification systems, and interdisciplinary cooperation can significantly reduce patient identification errors. PMID:27494020

  4. Local reduction in physics

    NASA Astrophysics Data System (ADS)

    Rosaler, Joshua

    2015-05-01

    A conventional wisdom about the progress of physics holds that successive theories wholly encompass the domains of their predecessors through a process that is often called "reduction." While certain influential accounts of inter-theory reduction in physics take reduction to require a single "global" derivation of one theory's laws from those of another, I show that global reductions are not available in all cases where the conventional wisdom requires reduction to hold. However, I argue that a weaker "local" form of reduction, which defines reduction between theories in terms of a more fundamental notion of reduction between models of a single fixed system, is available in such cases and moreover suffices to uphold the conventional wisdom. To illustrate the sort of fixed-system, inter-model reduction that grounds inter-theoretic reduction on this picture, I specialize to a particular class of cases in which both models are dynamical systems. I show that reduction in these cases is underwritten by a mathematical relationship that follows a certain liberalized construal of Nagel/Schaffner reduction, and support this claim with several examples. Moreover, I show that this broadly Nagelian analysis of inter-model reduction encompasses several cases that are sometimes cited as instances of the "physicist's" limit-based notion of reduction.

  5. Selective catalytic reduction system and process for treating NOx emissions using a zinc or titanium promoted palladium-zirconium catalyst

    DOEpatents

    Sobolevskiy, Anatoly; Rossin, Joseph A.; Knapke, Michael J.

    2011-08-02

    A process and system (18) for reducing NO.sub.x in a gas using hydrogen as a reducing agent is provided. The process comprises contacting the gas stream (29) with a catalyst system (38) comprising sulfated zirconia washcoat particles (41), palladium, a pre-sulfated zirconia binder (44), and a promoter (45) comprising at least one of titanium, zinc, or a mixture thereof. The presence of zinc or titanium increases the resistance of the catalyst system to a sulfur and water-containing gas stream.

  6. Electroless Pt deposition on Mn3O4 nanoparticles via the galvanic replacement process: electrocatalytic nanocomposite with enhanced performance for oxygen reduction reaction.

    PubMed

    Kim, Ki Woong; Kim, Soo Min; Choi, Suhee; Kim, Jongwon; Lee, In Su

    2012-06-26

    A novel electroless Pt deposition method was exploited by employing the galvanic replacement process occurring between the Mn(3)O(4) surface and PtCl(4)(2-) complexes. The newly discovered process provides a simple protocol to produce the catalytic nanocomposite, in which a high density of ultrafine Pt nanocrystals is stably immobilized in a homogeneously dispersive state on the surface of Mn(3)O(4) nanoparticles. When the eletrocatalytic activity was tested for the oxygen reduction reaction, which limits the rate of the overall process in proton-exchange membrane fuel cells, the resulting Pt/Mn(3)O(4) nanocomposite showed highly enhanced specific activity and durability, compared with those of the commercial Pt/C catalyst.

  7. Proceedings of waste stream minimization and utilization innovative concepts: An experimental technology exchange. Volume 1, Industrial solid waste processing municipal waste reduction/recycling

    SciTech Connect

    Lee, V.E.; Watts, R.L.

    1993-04-01

    This two-volume proceedings summarizes the results of fifteen innovations that were funded through the US Department of Energy`s Innovative Concept Program. The fifteen innovations were presented at the sixth Innovative Concepts Fair, held in Austin, Texas, on April 22--23, 1993. The concepts in this year`s fair address innovations that can substantially reduce or use waste streams. Each paper describes the need for the proposed concept, the concept being proposed, and the concept`s economics and market potential, key experimental results, and future development needs. The papers are divided into two volumes: Volume 1 addresses innovations for industrial solid waste processing and municipal waste reduction/recycling, and Volume 2 addresses industrial liquid waste processing and industrial gaseous waste processing. Selected papers have been indexed separately for inclusion in the Energy Science and Technology Database.

  8. Nurse-Driven Catheter-Associated Urinary Tract Infection Reduction Process and Protocol: Development Through an Academic-Practice Partnership.

    PubMed

    Johnson, Pamela; Gilman, Anna; Lintner, Alicia; Buckner, Ellen

    2016-01-01

    Translating evidence-based practices to the bedside can be facilitated by an active academic-practice partnership between nursing faculty and frontline nursing staff. A collaborative effort between the university's academic nurses and the medical center's clinical nurses explored, created, implemented, and evaluated an evidence-based nurse-driven protocol for decreasing the rate of catheter-associated urinary tract infections. The nurse-driven protocol was piloted in 4 intensive care units and included nurse-driven orders for catheter discontinuation, utilization of smaller bore urinary catheters, addition of silver-based cleansing products for urinary catheter care, and education of staff on routine catheter care and maintenance. Data were collected for more than 8 months pre- and postimplementation of the nurse-driven protocol. Postimplementation data revealed a 28% reduction in catheter-associated urinary tract infections in the intensive care units as compared with preimplementation. Secondary benefits of this academic-practice partnership included strengthening the legitimacy of classroom content as lessons learned were integrated into courses in the nursing curriculum. The result of the partnership was a stronger sense of collaboration and collegiality between hospital staff and the university faculty. Transformative leadership engaged numerous stakeholders through collaborative efforts to realize best practices. An academic-practice partnership facilitates transformative change and provides structural stability and sustainability.

  9. Studies on plutonium-zirconium co-precipitation and carbothermal reduction in the internal gelation process for nitride fuel preparation

    NASA Astrophysics Data System (ADS)

    Hedberg, Marcus; Ekberg, Christian

    2016-10-01

    Sol-gel based techniques are one way to lower the handling of highly radioactive powders when producing transuranium-containing fuel. In this work inert matrix (Zr0.6,Pu0.4)N fuel has been produced by internal gelation followed by carbothermal reduction. No co-gelation was observed during internal gelation and a two phase material could be detected by scanning electron microscopy in the nitrided microspheres. Sintering has been performed in both Ar and N2. X-ray diffraction revealed that sintering in N2 produced a solid solution, while sintering in Ar did not. The final metal composition in the microspheres was determined by ICP-MS to be about 41% Pu and 59% Zr. Vegard's law was applied to estimate the nitride purity in the solid solution pellet to be Zr0.6Pu0.4N0.87C0.13 making the final material more of a carbonitride than a pure nitride.

  10. Optimization of Cu/activated carbon catalyst in low temperature selective catalytic reduction of NO process using response surface methodology.

    PubMed

    Amanpour, Javad; Salari, Dariush; Niaei, Aligholi; Mousavi, Seyed Mahdi; Panahi, Parvaneh Nakhostin

    2013-01-01

    Preparation of Cu/Activated Carbon (Cu/AC) catalyst was optimized for low temperature selective catalytic reduction of NO by using response surface methodology. A central composite design (CCD) was used to investigate the effects of three independent variables, namely pre-oxidization degree (HNO3%), Cu loading (wt.%) and calcination temperature on NO conversion efficiency. The CCD was consisted of 20 different preparation conditions of Cu/AC catalysts. The prepared catalysts were characterized by XRD and SEM techniques. Predicting NO conversion was carried out using a second order model obtained from designed experiments and statistical software Minitab 14. Regression and Pareto graphic analysis showed that all of the chosen parameters and some interactions were effective on the NO conversion. The optimal values were pre-oxidization in 10.2% HNO3, 6.1 wt.% Cu loading and 480°C for calcination temperature. Under the optimum condition, NO conversion (94.3%) was in a good agreement with predicted value (96.12%).

  11. Degradation and antibiotic activity reduction of chloramphenicol in aqueous solution by UV/H2O2 process.

    PubMed

    Zuorro, Antonio; Fidaleo, Marco; Fidaleo, Marcello; Lavecchia, Roberto

    2014-01-15

    The efficacy of the UV/H2O2 process to degrade the antibiotic chloramphenicol (CHL) was investigated at 20 °C using a low-pressure mercury lamp as UV source. A preliminary analysis of CHL degradation showed that the process followed apparent first-order kinetics and that an optimum H2O2 concentration existed for the degradation rate. The first-order rate constant was used as the response variable and its dependence on initial CHL and H2O2 concentrations, UV light intensity and reaction time was investigated by a central composite design based on the response surface methodology. Analysis of response surface plots revealed a large positive effect of radiation intensity, a negative effect of CHL concentration and that there was a region of H2O2 concentration leading to maximum CHL degradation. CHL solutions submitted to the UV/H2O2 process were characterized by TOC and their activity against Escherichia coli and Staphylococcus aureus was assessed. No residual antibiotic activity was detected, even at CHL concentrations higher than those used in the designed experiments. Overall, the obtained results strongly support the possibility of reducing the risks associated with the release of CHL into the environment, including the spread of antibiotic resistance, by the UV/H2O2 process.

  12. The influence of oxidation reduction potential and water treatment processes on quartz lamp sleeve fouling in ultraviolet disinfection reactors.

    PubMed

    Wait, Isaac W; Johnston, Cliff T; Blatchley, Ernest R

    2007-06-01

    Ultraviolet (UV) disinfection systems are incorporated into drinking water production facilities because of their broad-spectrum antimicrobial capabilities, and the minimal disinfection by-product formation that generally accompanies their use. Selection of an optimal location for a UV system within a drinking water treatment facility depends on many factors; a potentially important consideration is the effect of system location on operation and maintenance issues, including the potential for fouling of quartz surfaces. To examine the effect of system location on fouling, experiments were conducted at a groundwater treatment facility, wherein aeration, chlorination, and sand filtration were applied sequentially for treatment. In this facility, access to the water stream was available prior to and following each of the treatment steps. Therefore, it was possible to examine the effects of each of these unit operations on fouling dynamics within a UV system. Results indicated zero-order formation kinetics for the fouling reactions at all locations. Increases in oxidation reduction potential, caused by water treatment steps such as aeration and chlorination, increased the rate of sleeve fouling and the rate of irradiance loss within the reactor. Analysis of metals in the sleeve foulant showed that calcium and iron predominate, and relative comparisons of foulant composition to water chemistry highlighted a high affinity for incorporation into the foulant matrix for both iron and manganese, particularly after oxidizing treatment steps. Fouling behavior was observed to be in qualitative agreement with representations of the degree of saturation, relative to the metal:ligand combinations that are believed to comprise a large fraction of the foulants that accumulate on the surfaces of quartz jackets in UV systems used to treat water.

  13. Numerical Study about the Influence of Wall Angle about Main Strains, Thickness Reduction and Forces on Single Point Incremental Forming Process

    NASA Astrophysics Data System (ADS)

    Oleksik, Valentin

    2016-12-01

    The current paper aims to study, using numerical simulation, the influence of the wall angle on the single point incremental forming process. For the analysis there has been used the LS-Dyna software and three explicit dynamic analyses were run for three parts with wall angles of 450, 550 and 650. The factors taken into account are the main strains, the thickness reduction and the forces on three directions. The material data introduced into the simulation were determined based on an uniaxial traction test on an Instron 5587 testing machine and the Aramis system was used as optical extensometer.

  14. Giardia duodenalis: Number and Fluorescence Reduction Caused by the Advanced Oxidation Process (H2O2/UV)

    PubMed Central

    Guimarães, José Roberto; Franco, Regina Maura Bueno; Guadagnini, Regiane Aparecida; dos Santos, Luciana Urbano

    2014-01-01

    This study evaluated the effect of peroxidation assisted by ultraviolet radiation (H2O2/UV), which is an advanced oxidation process (AOP), on Giardia duodenalis cysts. The cysts were inoculated in synthetic and surface water using a concentration of 12 g H2O2 L−1 and a UV dose (λ = 254 nm) of 5,480 mJcm−2. The aqueous solutions were concentrated using membrane filtration, and the organisms were observed using a direct immunofluorescence assay (IFA). The AOP was effective in reducing the number of G. duodenalis cysts in synthetic and surface water and was most effective in reducing the fluorescence of the cyst walls that were present in the surface water. The AOP showed a higher deleterious potential for G. duodenalis cysts than either peroxidation (H2O2) or photolysis (UV) processes alone. PMID:27379301

  15. Waste reduction process improvements in the analysis of plutonium by x-ray fluorescence: results from multiple data sets

    SciTech Connect

    Worley, Christopher G; Soderberg, Constance B; Townsend, Lisa E

    2010-01-01

    To minimize waste, improve process safety, and minimize costs, modifications were implemented to a method for quantifying gallium in plutonium metal using wavelength dispersive X-ray fluorescence. These changes included reducing sample sizes, reducing ion exchange process volumes, using cheaper reagent grade acids, eliminating the use of HF acid, and using more robust containment film for sample analysis. Relative precision and accuracy achieved from analyzing multiple aliquots from a single parent sample were {approx}0.2% and {approx}0.1% respectively. The same precision was obtained from analyzing a total of four parent materials, and the average relative accuracy from all the samples was 0.4%, which is within programmatic uncertainty requirements.

  16. A fast-settling frequency-presetting PLL frequency synthesizer with process variation compensation and spur reduction

    NASA Astrophysics Data System (ADS)

    Xiaozhou, Yan; Xiaofei, Kuang; Nanjian, Wu

    2009-04-01

    This paper proposes a fast-settling frequency-presetting PLL frequency synthesizer. A mixed-signal VCO and a digital processor are developed to accurately preset the frequency of VCO and greatly reduce the settling time. An auxiliary tuning loop is introduced in order to reduce reference spur caused by leakage current. The digital processor can automatically compensate presetting frequency variation with process and temperature, and control the operation of the auxiliary tuning loop. A 1.2 GHz integer-N synthesizer with 1 MHz reference input was implemented in a 0.18 μm process. The measured results demonstrate that the typical settling time of the synthesizer is less than 3 μs, and the phase noise is -108 dBc/Hz@ 1MHz. The reference spur is -52 dBc.

  17. Giardia duodenalis: Number and Fluorescence Reduction Caused by the Advanced Oxidation Process (H2O2/UV).

    PubMed

    Guimarães, José Roberto; Franco, Regina Maura Bueno; Guadagnini, Regiane Aparecida; Dos Santos, Luciana Urbano

    2014-01-01

    This study evaluated the effect of peroxidation assisted by ultraviolet radiation (H2O2/UV), which is an advanced oxidation process (AOP), on Giardia duodenalis cysts. The cysts were inoculated in synthetic and surface water using a concentration of 12 g H2O2 L(-1) and a UV dose (λ = 254 nm) of 5,480 mJcm(-2). The aqueous solutions were concentrated using membrane filtration, and the organisms were observed using a direct immunofluorescence assay (IFA). The AOP was effective in reducing the number of G. duodenalis cysts in synthetic and surface water and was most effective in reducing the fluorescence of the cyst walls that were present in the surface water. The AOP showed a higher deleterious potential for G. duodenalis cysts than either peroxidation (H2O2) or photolysis (UV) processes alone.

  18. The enhancement effect of pre-reduction using zero-valent iron on the solidification of chromite ore processing residue by blast furnace slag and calcium hydroxide.

    PubMed

    Li, Jinchunzi; Chen, Zhonglin; Shen, Jimin; Wang, Binyuan; Fan, Leitao

    2015-09-01

    A bench scale study was performed to assess the effectiveness of the solidification of chromite ore processing residue (COPR) by blast furnace slag and calcium hydroxide, and investigate the enhancement effect of pre-reduction using zero-valent iron (ZVI) on the solidification treatment. The degree of Cr immobilization was evaluated using the Toxicity Characteristic Leaching Procedure (TCLP) as well as the solid waste-extraction procedure for leaching toxicity-sulfuric acid & nitric acid method (Chinese standard HJ/T299-2007). Strength tests and semi-dynamic leaching tests were implemented to investigate the potential for reusing the final treatment product as a readily available construction material. The experimental results showed that the performance of pre-reduction/solidification (S/S) was superior to that of solidification alone. After pre-reduction, all of the S/S treated COPR samples met the TCLP limit for total Cr (5 mg L(-1)), whereas the samples with a COPR content below 40% met the pollution control limit of bricks and building block products (Chinese standard HJ/T 301-2007) produced with COPR for total Cr (0.3 mg L(-1)). At the same time, all of the S/S treated specimens tested were suitable for utilization at certain levels.

  19. Footprint Reduction Process: Using Remote Sensing and GIS Technologies to Identify Non-Contaminated Land Parcels on the Oak Ridge Reservation National Priorities List Site

    SciTech Connect

    Halsey, P.A.; Kendall, D.T.; King, A.L.; Storms, R.A.

    1998-12-09

    In 1989, the Agency for Toxic Substances and Disease Registry evaluated the entire 35,000-acre U. S: Department of Energy (DOE) Oak Ridge Reservation (ORR, located in Oak Ridge, TN) and placed it on the National Priorities List (NPL), making the ORR subject to Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) regulations. Although much of the ORR has not been impacted by previous federal activities, without investigation it is difficult to discern which parcels of land are free of surface contamination. In 1996, the DOE Oak Ridge Environmental Management Program (EM) funded the Footprint Reduction Project to: 1) develop a process to study the large areas of the ORR that are believed to be free of surface contamination and 2) initiate the delisting of the "clean" areas from the NPL. Although this project's goals do not include the transfer of federal property to non-federal entities, the process development team aimed to provide a final product with multiple uses. Therefore, the process was developed to meet the requirements of NPL delisting and the transfer of non- contaminated federal lands to future land users. Section 120 (h) of the CERCLA law identifies the requirements for the transfer of federal property that is currently part of an NPL site. Reviews of historical information (including aerial photography), field inspections, and the recorded chain of title documents for the property are required for the delisting of property prior to transfer from the federal government. Despite the widespread availability of remote sensing and other digital geographic data and geographic information systems (GIS) for the analysis of such data, historical aerial photography is the only geographic data source required for review under the CERCLA 120 (h) process. However, since the ORR Environmental Management Program had an established Remote Sensing Program, the Footprint Reduction Project included the development and application of a methodology

  20. The Integrated Field-Scale Subsurface Research Challenge Site (IFC) at Rifle, Colorado: Preliminary Results on Microbiological, Geochemical and Hydrologic Processes Controlling Iron Reduction and Uranium Mobility

    NASA Astrophysics Data System (ADS)

    Long, P. E.; Banfield, J.; Bush, R.; Campbell, K.; Chandler, D. P.; Davis, J. A.; Dayvault, R.; Druhan, J.; Elifantz, H.; Englert, A.; Hettich, R. L.; Holmes, D.; Hubbard, S.; Icenhower, J.; Jaffe, P. R.; Kerkhof, L. J.; Kukkadapu, R. K.; Lesher, E.; Lipton, M.; Lovley, D.; Morris, S.; Morrison, S.; Mouser, P.; Newcomer, D.; N'guessan, L.; Peacock, A.; Qafoku, N.; Resch, C. T.; Spane, F.; Spaulding, B.; Steefel, C.; Verberkmoes, N.; Wilkins, M.; Williams, K. H.; Yabusaki, S. B.

    2007-12-01

    The IFC at Rifle, Colorado was recently funded by the U.S. Department of Energy to address knowledge gaps in 1) geochemical and microbial controls on stimulated U(VI) bioreduction by iron-reducers, 2) U(VI) sorption under Fe-reducing conditions, 3) post-biostimulation U(VI) stability and removal, and 4) rates of natural bioreduction of U(VI). The over-arching goal of the project is to develop a mechanistic understanding of bioreductive and abiotic processes that control uranium mobility targeting new knowledge that can be translated into scientifically defensible flow and reactive transport process models. The Rifle IFC will conduct a focused set of field and lab experiments that use recently developed sciences of proteogenomics and stable isotope probing to track microbial metabolic status during acetate amendment. This information will be linked to changes in Fe redox status and sulfide minerals, with field-scale changes detected by non-invasive hydrogeophysics, including 3-D resistivity tomography. A key goal of the project is to combine abiotic sorption processes under reducing conditions with biotic processes controlling U(VI) reduction. The initial field-scale experiment for the Rifle IFC was conducted during the summer of 2007 with the objectives of collecting simultaneous metagenomic and proteomic samples during acetate amendment and to assess the impact of intentionally decreasing electron donor concentration on the metabolic processes of iron reducers. The 2007 experiment replicated previous field experiments, producing dominance of Geobacter sp. in groundwater within 10 days after the start of acetate amendment. The experiment also confirmed the importance of heterogeneities in controlling the flux of electron donor and the impact of naturally reduced zones on the duration of Fe reduction.

  1. A General Probabilistic Framework (GPF) for process-based models: blind validation, total error decomposition and uncertainty reduction.

    NASA Astrophysics Data System (ADS)

    Baroni, Gabriele; Jolley, Richard P.; Graeff, Thomas; Oswald, Sascha E.

    2014-05-01

    Process-based models are useful tools supporting research, policy analysis, and decision making. Ideally, they would only include input data and parameters having physical meaning and they could be applied in various conditions and scenario analysis. However, applicability of these models can be limited because they are affected by many sources of uncertainty, from scale issues to lack of knowledge. To overcome this limitation, a General Probabilistic Framework (GPF) for the application of process-based models is proposed. A first assessment of the performance of the model is conducted in a blind validation, assuming all the possible sources of uncertainty. The Sobol/Saltelli global sensitivity analysis is used to decompose the total uncertainty of the model output. Based on the results of the sensitivity analysis, improvements of the model application are considered in a goal-oriented approach, in which monitoring and modeling are related in a continuous learning process. This presentation describes the GPF and its application to two hydrological models. Firstly, the GPF is applied at field scale using a 1D physical-based hydrological model (SWAP). Secondly, the framework is applied at small catchment scale in combination with a spatially distributed hydrological model (SHETRAN). The models are evaluated considering different components of the water balance. The framework is conceptually simple, relatively easy to implement and it requires no modifications to existing source codes of simulation models. It can take into account all the various sources of uncertainty i.e. input data, parameters, model structures and observations. It can be extended to a wide variety of modelling applications, also when direct measurements of model output are not available. Further research will focus on the methods to account for correlation between the different sources of uncertainty.

  2. Reduction of organic trace compounds and fresh water consumption by recovery of advanced oxidation processes treated industrial wastewater.

    PubMed

    Bierbaum, S; Öller, H-J; Kersten, A; Klemenčič, A Krivograd

    2014-01-01

    Ozone (O(3)) has been used successfully in advanced wastewater treatment in paper mills, other sectors and municipalities. To solve the water problems of regions lacking fresh water, wastewater treated by advanced oxidation processes (AOPs) can substitute fresh water in highly water-consuming industries. Results of this study have shown that paper strength properties are not impaired and whiteness is slightly impaired only when reusing paper mill wastewater. Furthermore, organic trace compounds are becoming an issue in the German paper industry. The results of this study have shown that AOPs are capable of improving wastewater quality by reducing organic load, colour and organic trace compounds.

  3. Synchronistic preparation of fibre-like SiC and cubic-ZrO{sub 2}/SiC composite from zircon via carbothermal reduction process

    SciTech Connect

    Xu, Youguo; Liu, Yangai; Huang, Zhaohui; Fang, Minghao; Hu, Xiaozhi; Yin, Li; Huang, Juntong

    2013-01-15

    Graphical abstract: Display Omitted Highlights: ► Zircon carbothermal reduction was carried out in a tailor-made device at high-temperature air atmosphere. ► Fibre-like SiC and cubic-ZrO{sub 2}/SiC composite were obtained synchronically. ► Zirconium and silicon in zircon ore was initial separated. ► [SiO{sub 4}] was mutated to fibre-like SiC, while [ZrO{sub 8}] was transformed to cubic ZrO{sub 2}. ► The SiC were surprisingly enriched in the reducing atmosphere charred coal particles layers by gas–solid reaction. -- Abstract: Fibre-like SiC and cubic-ZrO{sub 2}/SiC composite were prepared respectively from zircon with yttrium oxide addition via carbothermal reduction process at 1600 °C for 4 h in an air atmosphere furnace, where the green samples were immerged in charred coal particles inside a high-temperature enclosed corundum crucible. The reaction products were characterized by XRD, XRF, XPS and SEM. The results indicate that ZrO{sub 2} in the products was mainly existed in the form of cubic phase. The reacted samples mainly contain cubic ZrO{sub 2}, β-SiC and trace amounts of zircon, with the SiC accounting for 14.8 wt%. Furthermore, a large quantity of fibre-like SiC was surprisingly found to concentrate in the charred coal particles layers around the samples. This study obtains fibre-like SiC and cubic-ZrO{sub 2}/SiC composite synchronically from zircon via carbothermal reduction process, which also bring a value-added high-performance application for natural zircon.

  4. Hydrogen production from the steam-iron process with direct reduction of iron oxide by chemical looping combustion of coal char

    SciTech Connect

    Jing-biao Yang; Ning-sheng Cai; Zhen-shan Li

    2008-07-15

    Experimental results performed with a fluidized-bed reactor supported the feasibility of the three processes including direct reduction of iron oxide by char, H{sub 2} production by the steam-iron process, and the oxidation of Fe{sub 3}O{sub 4} resulting from the steam-iron process to the original Fe{sub 2}O{sub 3} by air. Chars resulting from a Chinese lignite loaded with K{sub 2}CO{sub 3} were used successfully as a reducing material, leading to the reduction of Fe{sub 2}O{sub 3} to FeO and Fe for the steam-iron process, which was confirmed by both the off-gases concentrations and X-ray diffractometer analysis. The reduction of Fe{sub 2}O{sub 3} by K-10-char at 1073 K is desirable from the perspective of the carbon conversion rate and high concentration of CO{sub 2}. The carbon in char was completely converted to CO{sub 2} when the mass ratio of Fe{sub 2}O{sub 3}/K-10-char was increased to 10/0.3. The oxidation rate of K-10-char by Fe{sub 2}O{sub 3} without a gasifying agent was comparable to the K-10-char steam gasification rate. The fractions of FeO and Fe in the reduced residue were 43 and 57%, respectively, in the case of 3 g of Fe{sub 2}O{sub 3} and 0.5 g of K-10-char, which was verified by the total H{sub 2} yield equaling 1000 mL/g K-10-char from the steam-iron process. The time that it took to achieve complete oxidation of Fe{sub 3}O{sub 4} to Fe{sub 2}O{sub 3} by air with an 8.7% O{sub 2} concentration at 1073 K was about 15 min. 53 refs., 19 figs., 5 tabs.

  5. An optimal policy for a single-vendor and a single-buyer integrated system with setup cost reduction and process-quality improvement

    NASA Astrophysics Data System (ADS)

    Shu, Hui; Zhou, Xideng

    2014-05-01

    The single-vendor single-buyer integrated production inventory system has been an object of study for a long time, but little is known about the effect of investing in reducing setup cost reduction and process-quality improvement for an integrated inventory system in which the products are sold with free minimal repair warranty. The purpose of this article is to minimise the integrated cost by optimising simultaneously the number of shipments and the shipment quantity, the setup cost, and the process quality. An efficient algorithm procedure is proposed for determining the optimal decision variables. A numerical example is presented to illustrate the results of the proposed models graphically. Sensitivity analysis of the model with respect to key parameters of the system is carried out. The paper shows that the proposed integrated model can result in significant savings in the integrated cost.

  6. Cooperative catalysis of noncompatible catalysts through compartmentalization: wacker oxidation and enzymatic reduction in a one-pot process in aqueous media.

    PubMed

    Sato, Hirofumi; Hummel, Werner; Gröger, Harald

    2015-04-07

    A Wacker oxidation using CuCl/PdCl2 as a catalyst system was successfully combined with an enzymatic ketone reduction to convert styrene enantioselectively into 1-phenylethanol in a one-pot process, although the two reactions conducted in aqueous media are not compatible due to enzyme deactivation by Cu ions. The one-pot feasibility was achieved via compartmentalization of the reactions. Conducting the Wacker oxidation in the interior of a polydimethylsiloxane thimble enables diffusion of only the organic substrate and product into the exterior where the biotransformation takes place. Thus, the Cu ions detrimental to the enzyme are withheld from the reaction media of the biotransformation. In this one-pot process, which formally corresponds to an asymmetric hydration of alkenes, a range of 1-arylethanols were formed with high conversions and 98-99 % ee. In addition, the catalyst system of the Wacker oxidation was recycled 15 times without significant decrease in conversion.

  7. A New Mechanism in Electrochemical Process for Arsenic Oxidation: Production of H2O2 from Anodic O2 Reduction on the Cathode under Automatically Developed Alkaline Conditions.

    PubMed

    Qian, Ao; Yuan, Songhu; Zhang, Peng; Tong, Man

    2015-05-05

    Electrochemical cathodes are often used to reduce contaminants or produce oxidizing substances (i.e., H2O2). Alkaline conditions develop automatically around the cathode in electrochemical processes, and O2 diffuses onto the cathode easily. However, limited attention is paid to contaminant transformation by the reactive species produced on the cathode under oxic and alkaline conditions due to the inapplicability of pH for Fenton reaction. In this study, a new oxidation mechanism on the cathode is presented for contaminant transformation under automatically developed alkaline conditions. In an electrochemical sand column, 6.67 μM As(III) was oxidized by 36% when it passed through the cathode under the conditions of 30 mA current, an initial pH of 7.5 and a flow rate of 2 mL/min. Under the alkaline conditions (pH 10.0-11.0) that developed automatically around the cathode, the reduction potential of As(III) decreased greatly, allowing a pronounced oxidation by the small quantities of H2O2 produced from O2 reduction on the cathode. As(III) oxidation was further increased by the presence of soil pore water and groundwater solutes of HCO3-, Ca2+, Mg2+ and humic acid. The new oxidation mechanism found for the cathode under localized alkaline conditions supplements the fundamentals of contaminant transformation in electrochemical processes.

  8. On oscillation reduction in feedback control for processes with an uncertain dead time and internal-external disturbances.

    PubMed

    Zhang, Yuqiong; Li, Donghai; Gao, Zhiqiang; Zheng, Qinling

    2015-11-01

    This paper aims to find a practical solution to reduce oscillation on the Smith Predictor (SP) based design with the dead time (DT) uncertainty, making it less sensitive to DT change and more effective in disturbance rejection. First, a conditional feedback mechanism is introduced in SP to reduce the amount of oscillation caused by the model inaccuracies in the DT parameter. Then, to address the oscillation caused by the phase lag in traditional PI controller and uncertain dynamics, this conditional SP is combined with active disturbance rejection control (ADRC), assisted by the knowledge of process dynamics. A practical tuning method is provided for the practicing engineers. The proposed approach is validated in extensive simulation studies with different types of plants and in frequency domain analysis. The simulation results show significant improvements in performance robustness and transient response.

  9. Reduction of acrylamide level through blanching with treatment by an extremely thermostable L-asparaginase during French fries processing.

    PubMed

    Zuo, Shaohua; Zhang, Tao; Jiang, Bo; Mu, Wanmeng

    2015-07-01

    Bacterial L-asparaginase catalyzes the hydrolysis of L-asparagine to L-aspartic acid. It is normally used as an antineoplastic drug applied in lymphoblastic leukemia chemotherapy and as a food processing aid in baked or fried food industry to inhibit the formation of acrylamide. The present study demonstrates cloning, expression, and characterization of a thermostable L-asparaginase from Thermococcus zilligii AN1 TziAN1_1 and also evaluates the potential for enzymatic acrylamide mitigation in French fries using this enzyme. The recombinant L-asparaginase was purified to homogeneity by nickel-affinity chromatography. The purified enzyme displayed the maximum activity at pH 8.5 and 90 °C, and the optimum temperature was the highest ever reported. The K m, k cat, and k cat/K m values toward L-asparagine were measured to be 6.08 mM, 3267 s(-1), and 537.3 mM(-1) s(-1), respectively. The enzyme retained 70 % of its original activity after 2 h of incubation at 85 °C. When potato samples were treated with 10 U/mL of L-asparaginase at 80 °C for only 4 min, the acrylamide content in final French fries was reduced by 80.5 % compared with the untreated control. Results of this study revealed that the enzyme was highly active at elevated temperatures, reflecting the potential of the T. zilligii L-asparaginase in the food processing industry.

  10. Energy Conservation/Waste Reduction in the Processing of Soft (Unfired) Ceramic Particles Via Dynamic Cyclone Classification

    SciTech Connect

    Wright, Steve R.

    2003-04-15

    The objective of this project was to advance the development of a novel inertial classifier technology to a full-scale industrial product by sequentially evaluating performance of pre-commercial prototypes. The technology, termed a ''Dynamic Cyclone Classifier'' (DCC), utilizes boundary layers on rotating annular disks to effect particle separation with minimal particle-rotor impaction. Although a large (2-ton/hr) DCC was originally envisioned for use within the mining industry, a smaller (kg/hr) sub-10-mm ''Fine Particle Dynamic Cyclone Classifier'' (FPDCC) was subsequently developed as a result of market research that showed higher commercialization potential for classifying ultrafine powders. Modified FPDCC prototypes were iteratively tested and evaluated in the sub-10-mm particle size range using standardized test particles (i.e., ISO Fine test dust). Classification performance tests were assessed by varying device parameters to define the operational envelope of the device to obtain sharp classification cuts, to maximize particle dispersion, to limit particle attrition and to increase production yields. The FPDCC exhibited sub-10-mm performance using both ideal (ISO test dust) and pharmaceutical excipient (calcium carbonate) ultrafine powders. Performance was compared with conventional classification technologies having the ability to process sub-10-mm ultrafine powders, specifically high-efficiency cyclones (HECs) and rotary vane classifiers (RVCs). The FPDCC can generate sharper classification cuts than high-pressure/high efficiency cyclones (HECs), since there is no turbulent particle re-entrainment, while using as much as 95% less energy. Being vaneless, particle impact with high RPM rotor components in the FPDCC is much less severe than in rotary vane classifiers (RVCs), leading to less critical component wear/erosion and concomitantly reducing potential product attrition and contamination. FPDCC energy usage is also less than in RVCs, since rotating

  11. SU-C-18C-06: Radiation Dose Reduction in Body Interventional Radiology: Clinical Results Utilizing a New Imaging Acquisition and Processing Platform

    SciTech Connect

    Kohlbrenner, R; Kolli, KP; Taylor, A; Kohi, M; Fidelman, N; LaBerge, J; Kerlan, R; Gould, R

    2014-06-01

    Purpose: To quantify the patient radiation dose reduction achieved during transarterial chemoembolization (TACE) procedures performed in a body interventional radiology suite equipped with the Philips Allura Clarity imaging acquisition and processing platform, compared to TACE procedures performed in the same suite equipped with the Philips Allura Xper platform. Methods: Total fluoroscopy time, cumulative dose area product, and cumulative air kerma were recorded for the first 25 TACE procedures performed to treat hepatocellular carcinoma (HCC) in a Philips body interventional radiology suite equipped with Philips Allura Clarity. The same data were collected for the prior 85 TACE procedures performed to treat HCC in the same suite equipped with Philips Allura Xper. Mean values from these cohorts were compared using two-tailed t tests. Results: Following installation of the Philips Allura Clarity platform, a 42.8% reduction in mean cumulative dose area product (3033.2 versus 1733.6 mGycm∧2, p < 0.0001) and a 31.2% reduction in mean cumulative air kerma (1445.4 versus 994.2 mGy, p < 0.001) was achieved compared to similar procedures performed in the same suite equipped with the Philips Allura Xper platform. Mean total fluoroscopy time was not significantly different between the two cohorts (1679.3 versus 1791.3 seconds, p = 0.41). Conclusion: This study demonstrates a significant patient radiation dose reduction during TACE procedures performed to treat HCC after a body interventional radiology suite was converted to the Philips Allura Clarity platform from the Philips Allura Xper platform. Future work will focus on evaluation of patient dose reduction in a larger cohort of patients across a broader range of procedures and in specific populations, including obese patients and pediatric patients, and comparison of image quality between the two platforms. Funding for this study was provided by Philips Healthcare, with 5% salary support provided to authors K. Pallav

  12. Dilemmas in the process of weight reduction: Exploring how women experience training as a means of losing weight

    PubMed Central

    Groven, Karen Synne; Engelsrud, Gunn

    2010-01-01

    Patients diagnosed with obesity are usually offered group-based behavior interventions which include dietary advice and exercise programs. In particular, high-intensity training—combining weight lifting with aerobic exercising—has been proven effective for losing weight. Moreover, recent studies have shown that persons participating in high-intensity training are more likely to maintain their weight loss compared to persons with lower levels of physical activity. However, most of the research in the field has made use of quantitative methods focusing on the measurable effect of such interventions. Therefore, the aim of this study was to show how the training is experienced from a first-person perspective, namely the patients themselves. Our hope was to shed some new light on the process of weight loss that concerns more than the measurable “impacts” of the training. A qualitative approach was used based on interviews with five women selected from a primary healthcare clinic in Norway. Our results show that experiences of training are connected to the participants' general experience of being overweight. Both relationships to other people and earlier experiences are important for how the training is carried out and perceived. Five themes were identified supporting this line of argument: (1) the gaze of others; (2) a common ground; (3) dependence of close-follow up; (4) bodily discomfort as painful; and (5) aiming for results—an ambivalent experience. The results highlight the importance of finding the proper context and support for each patient's needs. PMID:20640017

  13. Evaluation of sludge reduction by an environmentally friendly chemical uncoupler in a pilot-scale anaerobic/anoxic/oxic process.

    PubMed

    Guo, Xuesong; Yang, Jianming; Liang, Yuan; Liu, Junxin; Xiao, Benyi

    2014-03-01

    An environmentally friendly chemical, tetrakis(hydroxymethyl)phosphonium sulfate (THPS), was used as a metabolic uncoupler to reduce sludge production in a pilot-scale anaerobic/anoxic/oxic process. The results show that the addition of THPS (1.08-1.86 mL/m(3) influent) in the sludge return section could reduce waste activated sludge by about 22.5 %, and decrease the sludge yield by about 14.7 % at the end of a run. At the same time, the addition of THPS slightly lowered the removal of chemical oxygen demand (COD), soluble COD and NH4 (+)-N, and slightly improved removal of total nitrogen. The effects of THPS addition on two characteristics of activated sludge in oxic tank are discussed in detail and the results suggest that the settleability of sludge was reduced by addition of THPS, while the specific oxygen uptake rate was increased. Molecular biology analysis shows that the addition of THPS had little effect on the microbial communities of sludge.

  14. Reduction in phytic acid content and enhancement of antioxidant properties of nutricereals by processing for developing a fermented baby food.

    PubMed

    Rasane, Prasad; Jha, Alok; Kumar, Arvind; Sharma, Nitya

    2015-06-01

    Cereal blends containing pearl millet (Pennisetum glaucum), sorghum (Sorghum bicolor) and oat (Avena sativa) in different ratios were processed (roasted and germinated) and also used as unprocessed flours followed by fermentation with Lactobacillus sp. (Lactobacillus casei and Lactobacillus plantarum). They were screened for total phenolic content (TPC), phytic acid content (PAC) and free radical scavenging activity (FRSA). A formulation with the highest TPC, FRSA and the lowest PAC was selected to optimize a nutricereal based fermented baby food containing selected fermented cereal blends (FCB), rice-corn cooked flour (RCF), whole milk powder (WMP), whey protein concentrate (WPC) and sugar. The optimized baby food formulation contained 37.41 g 100 g(-1) FCB, 9.75 g 100 g(-1) RCF, 27.84 g 100 g(-1) WMP, 5 g 100 g(-1) WPC and 20 g 100 g(-1) sugar. It had high protein, vitamin, minerals, as well as good quantity of carbohydrates and fat, to fulfil the nutritional needs of preschool children of age 1-3 years. The nutricereal based fermented baby food showed high water absorption capacity, dispersibility, wettability and flowability indicating good reconstitution properties.

  15. A Doping Lattice of Aluminum and Copper with Accelerated Electron Transfer Process and Enhanced Reductive Degradation Performance

    NASA Astrophysics Data System (ADS)

    Zhang, Lin; Gao, Xue; Zhang, Zhixuan; Zhang, Mingbo; Cheng, Yiqian; Su, Jixin

    2016-08-01

    Treatment of azo dye effluents has received increasing concerns over the years due to their potential harms to natural environment and human health. The present study described the degrading ability of the as-synthesized crystalline Al-Cu alloys for removal of high-concentration Acid Scarlet 3R in alkaline aqueous solutions and its degradation mechanism. Al-Cu alloy particles with Al/Cu ratios 19:1 were successfully synthesized by high-energy mechanical milling. Characterization results showed that 10 h mechanical alloying process could lead to the formation of crystalline Al(Cu) solid solution. Batch experiment results confirmed the excellent ability of Al-Cu alloy particles for the degradation of 3R in aqueous solution. Under a certain condition ([Al-Cu]0 = 2 g/L, [3R]0 = 200 mg/L, [NaCl]0 = 25 g/L, initial pH = 10.9), the 3R could be completely degraded within only 3 min. It was also found that the degradation reaction followed zero-order kinetics model with respect to the initial dye concentration. The intermediate compounds were identified by UV-vis, FT-IR and HPLC-MS, and a pathway was proposed. Additionally, post-treatment Al-Cu alloy particles were characterized by SEM and TEM, and the results showed that the degradation might be attributed to the corrosion effect of Al-Cu alloys.

  16. A Doping Lattice of Aluminum and Copper with Accelerated Electron Transfer Process and Enhanced Reductive Degradation Performance

    PubMed Central

    Zhang, Lin; Gao, Xue; Zhang, Zhixuan; Zhang, Mingbo; Cheng, Yiqian; Su, Jixin

    2016-01-01

    Treatment of azo dye effluents has received increasing concerns over the years due to their potential harms to natural environment and human health. The present study described the degrading ability of the as-synthesized crystalline Al-Cu alloys for removal of high-concentration Acid Scarlet 3R in alkaline aqueous solutions and its degradation mechanism. Al-Cu alloy particles with Al/Cu ratios 19:1 were successfully synthesized by high-energy mechanical milling. Characterization results showed that 10 h mechanical alloying process could lead to the formation of crystalline Al(Cu) solid solution. Batch experiment results confirmed the excellent ability of Al-Cu alloy particles for the degradation of 3R in aqueous solution. Under a certain condition ([Al-Cu]0 = 2 g/L, [3R]0 = 200 mg/L, [NaCl]0 = 25 g/L, initial pH = 10.9), the 3R could be completely degraded within only 3 min. It was also found that the degradation reaction followed zero-order kinetics model with respect to the initial dye concentration. The intermediate compounds were identified by UV-vis, FT-IR and HPLC-MS, and a pathway was proposed. Additionally, post-treatment Al-Cu alloy particles were characterized by SEM and TEM, and the results showed that the degradation might be attributed to the corrosion effect of Al-Cu alloys. PMID:27535800

  17. Influence of electron donors and copper concentration on geochemical and mineralogical processes under conditions of biological sulphate reduction

    NASA Astrophysics Data System (ADS)

    Wolicka, Dorota; Borkowski, Andrzej

    2014-03-01

    Sulphidogenous microorganism communities were isolated from soil polluted by crude oil. The study was focused on determining the influence of 1) copper (II) concentration on the activity of selected microorganism communities and 2) the applied electron donor on the course and evolution of mineral-forming processes under conditions favouring growth of sulphate-reducing bacteria (SRB). The influence of copper concentration on the activity of selected microorganism communities and the type of mineral phases formed was determined during experiments in which copper (II) chloride at concentrations of 0.1, 0.2, 0.5 and 0.7 g/L was added to SRB cultures. The experiments were performed in two variants: with ethanol (4 g/L) or lactate (4 g/L) as the sole carbon source. In order to determine the taxonomic composition of the selected microorganism communities, the 16S rRNA method was used. Results of this analysis confirmed the presence of Desulfovibrio, Desulfohalobium, Desulfotalea, Thermotoga, Solibacter, Gramella, Anaeromyxobacter and Myxococcus sp. in the stationary cultures. The post-culture sediments contained covelline (CuS) and digenite (Cu9S5 ). Based on the results, it can be stated that the type of carbon source applied during incubation plays a crucial role in determining the mineral composition of the post-culture sediments. Thus, regardless of the amount of copper ion introduced to a culture with lactate as the sole carbon source, no copper sulphide was observed in the post-culture sediments. Cultures with ethanol as the sole carbon source, on the other hand, yielded covelline or digenite in all post-culture sediments.

  18. A Doping Lattice of Aluminum and Copper with Accelerated Electron Transfer Process and Enhanced Reductive Degradation Performance.

    PubMed

    Zhang, Lin; Gao, Xue; Zhang, Zhixuan; Zhang, Mingbo; Cheng, Yiqian; Su, Jixin

    2016-08-18

    Treatment of azo dye effluents has received increasing concerns over the years due to their potential harms to natural environment and human health. The present study described the degrading ability of the as-synthesized crystalline Al-Cu alloys for removal of high-concentration Acid Scarlet 3R in alkaline aqueous solutions and its degradation mechanism. Al-Cu alloy particles with Al/Cu ratios 19:1 were successfully synthesized by high-energy mechanical milling. Characterization results showed that 10 h mechanical alloying process could lead to the formation of crystalline Al(Cu) solid solution. Batch experiment results confirmed the excellent ability of Al-Cu alloy particles for the degradation of 3R in aqueous solution. Under a certain condition ([Al-Cu]0 = 2 g/L, [3R]0 = 200 mg/L, [NaCl]0 = 25 g/L, initial pH = 10.9), the 3R could be completely degraded within only 3 min. It was also found that the degradation reaction followed zero-order kinetics model with respect to the initial dye concentration. The intermediate compounds were identified by UV-vis, FT-IR and HPLC-MS, and a pathway was proposed. Additionally, post-treatment Al-Cu alloy particles were characterized by SEM and TEM, and the results showed that the degradation might be attributed to the corrosion effect of Al-Cu alloys.

  19. Lead recovery and high silica glass powder synthesis from waste CRT funnel glasses through carbon thermal reduction enhanced glass phase separation process.

    PubMed

    Xing, Mingfei; Fu, Zegang; Wang, Yaping; Wang, Jingyu; Zhang, Zhiyuan

    2017-01-15

    In this study, a novel process for the removal of toxic lead from the CRT funnel glass and synchronous preparation of high silica glass powder was developed by a carbon-thermal reduction enhanced glass phase separation process. CRT funnel glass was remelted with B2O3 in reducing atmosphere. In the thermal process, a part of PbO contained in the funnel glass was reduced into metallic Pb and detached from the glass phase. The rest of PbO and other metal oxides (including Na2O, K2O, Al2O3, BaO and CaO) were mainly concentrated in the boric oxide phase. The metallic Pb phase and boric oxide phase were completely leached out by 5mol/L HNO3. The lead removal rate was 99.80% and high silica glass powder (SiO2 purity >95wt%) was obtained by setting the temperature, B2O3 added amount and holding time at 1000°C, 20% and 30mins, respectively. The prepared high silicate glass powders can be used as catalyst carrier, semipermeable membranes, adsorbents or be remelted into high silicate glass as an ideal substitute for quartz glass. Thus this study proposed an eco-friendly and economical process for recycling Pb-rich electronic glass waste.

  20. Facile preparation of carbon coated magnetic Fe{sub 3}O{sub 4} particles by a combined reduction/CVD process

    SciTech Connect

    Tristao, Juliana C.; Oliveira, Aline A.S.; Ardisson, Jose D.; Dias, Anderson; Lago, Rochel M.

    2011-05-15

    Graphical abstract: Magnetic carbon coated Fe{sub 3}O{sub 4} particles are prepared by a one step combined reduction of Fe{sub 2}O{sub 3} together with a CVD process of using methane. Analyses show that the Fe{sub 2}O{sub 3} is reduced by methane to produce mainly Fe{sub 3}O{sub 4} particles coated with amorphous carbon. These materials can be separated into two fractions by simple dispersion in water and can be used as adsorbents, catalyst supports and rapid coagulation systems. Research highlights: {yields} Magnetic Fe{sub 3}O{sub 4} particles coated with a very thin layer of amorphous carbon (4 wt%). {yields} Combined reduction of Fe{sub 2}O{sub 3} with a Chemical Vapor Deposition process using methane. {yields} Nanoparticles with an average size of 100-200 nm. {yields} Uses as adsorbent, catalyst support and rapid coagulation systems. -- Abstract: In this work, we report a simple method for the preparation of magnetic carbon coated Fe{sub 3}O{sub 4} particles by a single step combined reduction of Fe{sub 2}O{sub 3} together with a Chemical Vapor Deposition process using methane. The temperature programmed reaction monitored by Moessbauer, X-ray Diffraction and Raman analyses showed that Fe{sub 2}O{sub 3} is directly reduced by methane at temperatures between 600 and 900 {sup o}C to produce mainly Fe{sub 3}O{sub 4} particles coated with up to 4 wt% of amorphous carbon. These magnetic materials can be separated into two fractions by simple dispersion in water, i.e., a settled material composed of large magnetic particles and a suspended material composed of nanoparticles with an average size of 100-200 nm as revealed by Scanning Electron Microscopy and High-resolution Transmission Electron Microscopy. Different uses for these materials, e.g., adsorbents, catalyst supports, rapid coagulation systems, are proposed.

  1. Managing Faculty Reductions

    ERIC Educational Resources Information Center

    Alm, Kent F.; And Others

    1977-01-01

    A process for the management of reductions in the number of faculty positions available to a university is described. It considers staffing by projections, the evolution of personnel planning, and the balance of reductions in faculty and administration, along with coping strategies and advice growing out of five years of enrollment decline…

  2. Metal and alloy nanoparticles by amine-borane reduction of metal salts by solid-phase synthesis: atom economy and green process.

    PubMed

    Sanyal, Udishnu; Jagirdar, Balaji R

    2012-12-03

    A new solid state synthetic route has been developed toward metal and bimetallic alloy nanoparticles from metal salts employing amine-boranes as the reducing agent. During the reduction, amine-borane plays a dual role: acts as a reducing agent and reduces the metal salts to their elemental form and simultaneously generates a stabilizing agent in situ which controls the growth of the particles and stabilizes them in the nanosize regime. Employing different amine-boranes with differing reducing ability (ammonia borane (AB), dimethylamine borane (DMAB), and triethylamine borane (TMAB)) was found to have a profound effect on the particle size and the size distribution. Usage of AB as the reducing agent provided the smallest possible size with best size distribution. Employment of TMAB also afforded similar results; however, when DMAB was used as the reducing agent it resulted in larger sized nanoparticles that are polydisperse too. In the AB mediated reduction, BNH(x) polymer generated in situ acts as a capping agent whereas, the complexing amine of the other amine-boranes (DMAB and TMAB) play the same role. Employing the solid state route described herein, monometallic Au, Ag, Cu, Pd, and Ir and bimetallic CuAg and CuAu alloy nanoparticles of <10 nm were successfully prepared. Nucleation and growth processes that control the size and the size distribution of the resulting nanoparticles have been elucidated in these systems.

  3. Calculation of energy recovery and greenhouse gas emission reduction from palm oil mill effluent treatment by an anaerobic granular-sludge process.

    PubMed

    Show, K Y; Ng, C A; Faiza, A R; Wong, L P; Wong, L Y

    2011-01-01

    Conventional aerobic and low-rate anaerobic processes such as pond and open-tank systems have been widely used in wastewater treatment. In order to improve treatment efficacy and to avoid greenhouse gas emissions, conventional treatment can be upgraded to a high performance anaerobic granular-sludge system. The anaerobic granular-sludge systems are designed to capture the biogas produced, rendering a potential for claims of carbon credits under the Kyoto Protocol for reducing emissions of greenhouse gases. Certified Emission Reductions (CERs) would be issued, which can be exchanged between businesses or bought and sold in international markets at the prevailing market prices. As the advanced anaerobic granular systems are capable of handling high organic loadings concomitant with high strength wastewater and short hydraulic retention time, they render more carbon credits than other conventional anaerobic systems. In addition to efficient waste degradation, the carbon credits can be used to generate revenue and to finance the project. This paper presents a scenario on emission avoidance based on a methane recovery and utilization project. An example analysis on emission reduction and an overview of the global emission market are also outlined.

  4. A Cinchona Alkaloid-Functionalized Mesostructured Silica for Construction of Enriched Chiral β-Trifluoromethyl-β-Hydroxy Ketones over An Epoxidation-Relay Reduction Process.

    PubMed

    Li, Cuibao; Shu, Xiaomin; Li, Liang; Zhang, Genwei; Jin, Ronghua; Cheng, Tanyu; Liu, Guohua

    2016-07-20

    A cinchona alkaloid-functionalized heterogeneous catalyst is prepared through a thiol-ene click reaction of chiral N-(3,5-ditrifluoromethylbenzyl)quininium bromide and a mesostructured silica, which is obtained by co-condensation of 1,2-bis(triethoxysilyl)ethane and 3-(triethoxysilyl)propane-1-thiol. Structural analyses and characterizations disclose its well-defined chiral single-site active center, and electron microscopy images reveal its monodisperse property. As a heterogenous catalyst, it enables an efficient asymmetric epoxidation of achiral β-trifluoromethyl-β,β-disubstituted enones, the obtained chiral products can then be converted easily into enriched chiral β-trifluoromethyl-β-hydroxy ketones through a sequential epoxidation-relay reduction process. Furthermore, such a heterogeneous catalyst can be recovered conveniently and reused in asymmetric epoxidation of 4,4,4-trifluoro-1,3-diphenylbut-2-enone, showing an attractive feature in a practical construction of enriched chiral β-CF3 -substituted molecules.

  5. Enhanced nitrogen and phosphorus removal by an advanced simultaneous sludge reduction, inorganic solids separation, phosphorus recovery, and enhanced nutrient removal wastewater treatment process.

    PubMed

    Yan, Peng; Guo, Jin-Song; Wang, Jing; Chen, You-Peng; Ji, Fang-Ying; Dong, Yang; Zhang, Hong; Ouyang, Wen-juan

    2015-05-01

    An advanced wastewater treatment process (SIPER) was developed to simultaneously decrease sludge production, prevent the accumulation of inorganic solids, recover phosphorus, and enhance nutrient removal. The feasibility of simultaneous enhanced nutrient removal along with sludge reduction as well as the potential for enhanced nutrient removal via this process were further evaluated. The results showed that the denitrification potential of the supernatant of alkaline-treated sludge was higher than that of the influent. The system COD and VFA were increased by 23.0% and 68.2%, respectively, after the return of alkaline-treated sludge as an internal C-source, and the internal C-source contributed 24.1% of the total C-source. A total of 74.5% of phosphorus from wastewater was recovered as a usable chemical crystalline product. The nitrogen and phosphorus removal were improved by 19.6% and 23.6%, respectively, after incorporation of the side-stream system. Sludge minimization and excellent nutrient removal were successfully coupled in the SIPER process.

  6. Innovative Clean Coal Technology (ICCT): Demonstration of innovative applications of technology for cost reductions to the CT-121 FGD process. Quarterly report No. 6, July--September 1991

    SciTech Connect

    Not Available

    1991-11-15

    The project`s objective is to demonstrate innovative applications of technology for cost reduction for the Chiyoda Thoroughbred-121 (CT-121) process. The CT-121 process is a wet FGD process that removes SO{sub 2}, can achieve simultaneous particulate control, and can produce a salable by-product gypsum thereby reducing or even eliminating solid waste disposal problems. Figure 1 shows a flow schematic of the process. CT-121 removes SO{sub 2} and particulate matter in a unique limestone-based scrubber called the Jet Bubbling Reactor (JBR). IN the JBR, flue gas bubbles beneath the slurry, SO{sub 2} is absorbed, and particulate matter is removed from the gas. The agitator circulates limestone slurry to ensure that fresh reactant is always available in the bubbling or froth zone sot that SO{sub 2} removal can proceed at a rapid rate. Air is introduced into the bottom of the JBR to oxidize the absorbed SO{sub 2} to sulfate, and limestone is added continuously to neutralize the acid slurry and form gypsum. The JBR is designed to allow ample time for complete oxidation of the SO{sub 2}, for complete reaction of the limestone, and for growth of large gypsum crystals. The gypsum slurry is continuously withdrawn from the JBR and is to be dewatered in a gypsum stack. The stacking technique involves filing a diked area with gypsum slurry, allowing the gypsum solids to settle, and removing clear liquid from the top of the stack for recycle back to the process.

  7. Continuous read-out of cytochrome b, flavin and pyridine nucleotide oxido-reduction processes in the perfused frog heart and contracting skeletal muscle.

    PubMed

    Rossini, L; Rossini, P; Chance, B

    1991-05-01

    The time-sharing instrument for continuous read-out of the fluorescence levels of NAD(P)H and oxidized-flavoproteins, which also makes simultaneous dual beam differential absorption measurements of cytochrome b, has been applied to the study of the metabolic control of the frog heart, perfused in vitro with normal and variously modified Ringer solutions, and to the frog skeletal muscle in situ. In the ionically depolarized resting heart, the long term kinetic analysis of the redox processes during oxygen/anoxia transitions has proved to be an adequate method for identifying and following three fundamental intracellular redox compartments: (1) the respiratory system, (2) the microsomal system, and (3) the glycolytic system. The provision of substrates and/or suitable inhibitors has allowed the description of functional interrelationships within the mitochondrial and the cytoplasmic spaces. The ouabain major site of response has been located on the cytosolic pyridine nucleotides, with a very small response in the mitochondrial space. The switching on and off of substantial fractions of the NAD(P)+/NAD(P)H and Fpoxidized/Fpreduced pools has been observed, which helps to clarify the large phase shift between the overall pyridine nucleotide and flavin oxidation-reduction processes, during the cycle of the spontaneously beating heart and during skeletal muscle contraction and recovery, here originally prompted out.

  8. Pathway of FeEDTA transformation and its impact on performance of NOx removal in a chemical absorption-biological reduction integrated process

    NASA Astrophysics Data System (ADS)

    Li, Wei; Zhao, Jingkai; Zhang, Lei; Xia, Yinfeng; Liu, Nan; Li, Sujing; Zhang, Shihan

    2016-01-01

    A novel chemical absorption-biological reduction (CABR) integrated process, employing ferrous ethylenediaminetetraacetate (Fe(II)EDTA) as a solvent, is deemed as a potential option for NOx removal from the flue gas. Previous work showed that the Fe(II)EDTA concentration was critical for the NOx removal in the CABR process. In this work, the pathway of FeEDTA (Fe(III)/Fe(II)-EDTA) transformation was investigated to assess its impact on the NOx removal in a biofilter. Experimental results revealed that the FeEDTA transformation involved iron precipitation and EDTA degradation. X-ray photoelectron spectroscopy analysis confirmed the iron was precipitated in the form of Fe(OH)3. The iron mass balance analysis showed 44.2% of the added iron was precipitated. The EDTA degradation facilitated the iron precipitation. Besides chemical oxidation, EDTA biodegradation occurred in the biofilter. The addition of extra EDTA helped recover the iron from the precipitation. The transformation of FeEDTA did not retard the NO removal. In addition, EDTA rather than the iron concentration determined the NO removal efficiency.

  9. A 400 MHz Wireless Neural Signal Processing IC With 625 × On-Chip Data Reduction and Reconfigurable BFSK/QPSK Transmitter Based on Sequential Injection Locking.

    PubMed

    Teng, Kok-Hin; Wu, Tong; Liu, Xiayun; Yang, Zhi; Heng, Chun-Huat

    2017-03-03

    An 8-channel wireless neural signal processing IC, which can perform real-time spike detection, alignment, and feature extraction, and wireless data transmission is proposed. A reconfigurable BFSK/QPSK transmitter (TX) at MICS/MedRadio band is incorporated to support different data rate requirement. By using an Exponential Component-Polynomial Component (EC-PC) spike processing unit with an incremental principal component analysis (IPCA) engine, the detection of neural spikes with poor SNR is possible while achieving 625× data reduction. For the TX, a dual-channel at 401 MHz and 403.8 MHz are supported by applying sequential injection locked techniques while attaining phase noise of -102 dBc/Hz at 100 kHz offset. From the measurement, error vector magnitude (EVM) of 4.60%/9.55% with power amplifier (PA) output power of -15 dBm is achieved for the QPSK at 8 Mbps and the BFSK at 12.5 kbps. Fabricated in 65 nm CMOS with an active area of 1 mm (2), the design consumes a total current of 5  ∼ 5.6 mA with a maximum energy efficiency of 0.7 nJ/b.

  10. Pathway of FeEDTA transformation and its impact on performance of NOx removal in a chemical absorption-biological reduction integrated process.

    PubMed

    Li, Wei; Zhao, Jingkai; Zhang, Lei; Xia, Yinfeng; Liu, Nan; Li, Sujing; Zhang, Shihan

    2016-01-08

    A novel chemical absorption-biological reduction (CABR) integrated process, employing ferrous ethylenediaminetetraacetate (Fe(II)EDTA) as a solvent, is deemed as a potential option for NOx removal from the flue gas. Previous work showed that the Fe(II)EDTA concentration was critical for the NOx removal in the CABR process. In this work, the pathway of FeEDTA (Fe(III)/Fe(II)-EDTA) transformation was investigated to assess its impact on the NOx removal in a biofilter. Experimental results revealed that the FeEDTA transformation involved iron precipitation and EDTA degradation. X-ray photoelectron spectroscopy analysis confirmed the iron was precipitated in the form of Fe(OH)3. The iron mass balance analysis showed 44.2% of the added iron was precipitated. The EDTA degradation facilitated the iron precipitation. Besides chemical oxidation, EDTA biodegradation occurred in the biofilter. The addition of extra EDTA helped recover the iron from the precipitation. The transformation of FeEDTA did not retard the NO removal. In addition, EDTA rather than the iron concentration determined the NO removal efficiency.

  11. Role of intensive milling in the processing of barium ferrite/magnetite/iron hybrid magnetic nano-composites via partial reduction of barium ferrite

    SciTech Connect

    Molaei, M.J.; Ataie, A.; Raygan, S.; Picken, S.J.

    2015-03-15

    In this research a mixture of barium ferrite and graphite was milled for different periods of time and then heat treated at different temperatures. The effects of milling time and heat treatment temperature on the phase composition, thermal behavior, morphology and magnetic properties of the samples have been investigated using X-ray diffraction, differential thermal analysis, high resolution transmission electron microscopy and vibrating sample magnetometer techniques, respectively. X-ray diffraction results revealed that BaFe{sub 12}O{sub 19}/Fe{sub 3}O{sub 4} nanocomposites form after a 20 h milling due to the partial reduction of BaFe{sub 12}O{sub 19}. High resolution transmission electron microscope images of a 40 h milled sample showed agglomerated structure consisting of nanoparticles with a mean particle size of 30 nm. Thermal analysis of the samples via differential thermal analysis indicated that for un-milled samples, heat treatment up to 900 °C did not result in α-Fe formation, while for a 20 h milled sample heat treatment at 700 °C resulted in reduction process progress to the formation of α-Fe. Wustite was disappeared in an X-ray diffraction pattern of a heat treated sample at 850 °C, by increasing the milling time from 20 to 40 h. By increasing the milling time, the structure of heat treated samples becomes magnetically softer due to an increase in saturation magnetization and a decrease in coercivity. Saturation magnetization and coercivity of a sample milled for 20 h and heat treated at 850 °C were 126.3 emu/g and 149.5 Oe which by increasing the milling time to 40 h, alter to 169.1 emu/g and 24.3 Oe, respectively. High coercivity values of milled and heat treated samples were attributed to the nano-scale formed iron particles. - Graphical abstract: Display Omitted - Highlights: • Barium ferrite and graphite were treated mechano-thermally. • Increasing milling time increases reduction progress after heat treatment. • Composites

  12. Acute toxicity reduction and toxicity identification in pigment-contaminated wastewater during anaerobic-anoxic-oxic (A/A/O) treatment process.

    PubMed

    Deng, Minjie; Zhang, Ying; Quan, Xie; Na, Chunhong; Chen, Shuo; Liu, Wei; Han, Shuping; Masunaga, Shigeki

    2017-02-01

    In China, a considerable part of industrial wastewater effluents are discharged into the municipal wastewater treatment plants (WWTPs) after pretreatment in their own wastewater treatment plants. Even though the industrial effluents meet the professional emission standards, many micro-pollutants still remained, and they could be resistant in the municipal WWTPs with conventional activated sludge process. Pigment wastewater was chosen in this study, and the acute toxicity reduction and identification of the pigment-contaminated wastewater treated by the conventional anaerobic-anoxic-oxic (A/A/O) process were evaluated. Results indicated that the raw pigment-contaminated wastewater was acutely toxic to Photobacterium phosphoreum (P. phosphoreum), Daphnia magna (D. magna) and Danio rerio (D. rerio). The acute toxicity was decreased in some degree after A/A/O treatment, but the final effluent still exhibited acute toxicity to D. magna and D. rerio with the toxic units (TU) of 1.1 and 2.0, respectively. Chemical analyses showed the presence of various refractory and toxic nitrogen-containing polycyclic and heterocyclic compounds in the pigment-contaminated wastewater. Toxicity identification by combining chemical analyses and correlation analysis showed that N-containing refractory organic toxicants were the main toxicity source for the pigment-contaminated wastewater, and several toxicants showed significant correlation with P. phosphoreum and D. magna. This study indicated that the A/A/O process was not efficient for pigment-contaminated wastewater treatment, and it was irradiative for technology improvement in the WWTPs receiving pretreated industrial wastewater effluents.

  13. Partitioning of mercury, arsenic, selenium, boron, and chloride in a full-scale coal combustion process equipped with selective catalytic reduction, electrostatic precipitation, and flue gas desulfurization systems

    SciTech Connect

    Chin-Min Cheng; Pauline Hack; Paul Chu; Yung-Nan Chang; Ting-Yu Lin; Chih-Sheng Ko; Po-Han Chiang; Cheng-Chun He; Yuan-Min Lai; Wei-Ping Pan

    2009-09-15

    A full-scale field study was carried out at a 795 MWe coal-fired power plant equipped with selective catalytic reduction (SCR), an electrostatic precipitator (ESP), and wet flue gas desulfurization (FGD) systems to investigate the distribution of selected trace elements (i.e., mercury, arsenic, selenium, boron, and chloride) from coal, FGD reagent slurry, makeup water to flue gas, solid byproduct, and wastewater streams. Flue gases were collected from the SCR outlet, ESP inlet, FGD inlet, and stack. Concurrent with flue gas sampling, coal, bottom ash, economizer ash, and samples from the FGD process were also collected for elemental analysis. By combining plant operation parameters, the overall material balances of selected elements were established. The removal efficiencies of As, Se, Hg, and B by the ESP unit were 88, 56, 17, and 8%, respectively. Only about 2.5% of Cl was condensed and removed from flue gas by fly ash. The FGD process removed over 90% of Cl, 77% of B, 76% of Hg, 30% of Se, and 5% of As. About 90% and 99% of the FGD-removed Hg and Se were associated with gypsum. For B and Cl, over 99% were discharged from the coal combustion process with the wastewater. Mineral trona (trisodium hydrogendicarbonate dehydrate, Na{sub 3}H(CO{sub 3}){sub 2}.2H{sub 2}O) was injected before the ESP unit to control the emission of sulfur trioxide (SO{sub 3}). By comparing the trace elements compositions in the fly ash samples collected from the locations before and after the trona injection, the injection of trona did not show an observable effect on the partitioning behaviors of selenium and arsenic, but it significantly increased the adsorption of mercury onto fly ash. The stack emissions of mercury, boron, selenium, and chloride were for the most part in the gas phase. 47 refs., 3 figs., 11 tabs.

  14. Chemically induced reduction: A viable process for synthesizing {gamma}-TiAl based intermetallic matrix composite powders containing nanocrystalline TiC

    SciTech Connect

    Kim, J.Y.; Chang, K.; Kumta, P.N.

    2000-02-01

    A chemically induced reduction process has been developed for synthesizing intermetallic matrix composites (IMCs) consisting of titanium aluminide and titanium carbide. The process involves the reduction of metal chlorides (TiCl{sub 4} and AlCl{sub 3}) with metallic lithium in polar organic solvents such as acetonitrile (MeCN) and tetrahydrofuran (THF) to form a colloidal precursor. The as-prepared precursors have been either directly heat treated in ultra-high-purity argon (UHP-Ar) or pretreated in hydrogen (H{sub 2}) followed by further heat treatment in UHP-Ar. The powders have been characterized primarily using X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Results of the structural analyses conducted on the heat-treated precursors derived using MeCN as a solvent indicate the formation of either single-phase titanium carbide (TiC) or a composite mixture of {gamma}-TiAl and nanocrystalline TiC, depending on the heat-treatment conditions. The formation of TiC is related to the strong interaction between TiCl{sub 4} and the polar organic solvents resulting in the formation of adducts which contain primary Ti-C linkages. Pretreatment of the precursors derived using MeCN as a solvent in H{sub 2} promotes the removal of carbon and results in the formation of the composite mixture of {gamma}-TiAl and TiC after subsequent Ar treatment at 1200 C. At this stage, washing the pretreated powders in water helps to minimize and even eliminate any impurity phases to a large extent, leaving behind phase-pure composites containing {gamma}-TiAl and TiC after the final Ar treatment. However, extended pretreatment in H{sub 2} appears to be ineffective toward removal of additional carbon and leads to formation of hydride-phase impurities. On the other hand, the reductive reaction conducted using THF as a solvent results in minimizing the amount of carbon while inducing the formation of {gamma}-TiAl during direct Ar treatment

  15. Biogenic hydrogen conversion of de-oiled jatropha waste via anaerobic sequencing batch reactor operation: process performance, microbial insights, and CO2 reduction efficiency.

    PubMed

    Kumar, Gopalakrishnan; Lin, Chiu-Yue

    2014-01-01

    We report the semicontinuous, direct (anaerobic sequencing batch reactor operation) hydrogen fermentation of de-oiled jatropha waste (DJW). The effect of hydraulic retention time (HRT) was studied and results show that the stable and peak hydrogen production rate of 1.48 L/L ∗ d and hydrogen yield of 8.7 mL H2/g volatile solid added were attained when the reactor was operated at HRT 2 days (d) with a DJW concentration of 200 g/L, temperature 55 °C, and pH 6.5. Reduced HRT enhanced the production performance until 1.75 d. Further reduction has lowered the process efficiency in terms of biogas production and hydrogen gas content. The effluent from hydrogen fermentor was utilized for methane fermentation in batch reactors using pig slurry and cow dung as seed sources. The results revealed that pig slurry was a feasible seed source for methane generation. Peak methane production rate of 0.43 L CH4/L ∗ d and methane yield of 20.5 mL CH4/g COD were observed at substrate concentration of 10 g COD/L, temperature 30 °C, and pH 7.0. PCR-DGGE analysis revealed that combination of cellulolytic and fermentative bacteria were present in the hydrogen producing ASBR.

  16. Biogenic Hydrogen Conversion of De-Oiled Jatropha Waste via Anaerobic Sequencing Batch Reactor Operation: Process Performance, Microbial Insights, and CO2 Reduction Efficiency

    PubMed Central

    Lin, Chiu-Yue

    2014-01-01

    We report the semicontinuous, direct (anaerobic sequencing batch reactor operation) hydrogen fermentation of de-oiled jatropha waste (DJW). The effect of hydraulic retention time (HRT) was studied and results show that the stable and peak hydrogen production rate of 1.48 L/L∗d and hydrogen yield of 8.7 mL H2/g volatile solid added were attained when the reactor was operated at HRT 2 days (d) with a DJW concentration of 200 g/L, temperature 55°C, and pH 6.5. Reduced HRT enhanced the production performance until 1.75 d. Further reduction has lowered the process efficiency in terms of biogas production and hydrogen gas content. The effluent from hydrogen fermentor was utilized for methane fermentation in batch reactors using pig slurry and cow dung as seed sources. The results revealed that pig slurry was a feasible seed source for methane generation. Peak methane production rate of 0.43 L CH4/L∗d and methane yield of 20.5 mL CH4/g COD were observed at substrate concentration of 10 g COD/L, temperature 30°C, and pH 7.0. PCR-DGGE analysis revealed that combination of celluloytic and fermentative bacteria were present in the hydrogen producing ASBR. PMID:24672398

  17. Ultrasonic Waves and Strength Reduction Indexes for the Assessment of the Advancement of Deterioration Processes in Travertines from Pamukkale and Hierapolis (Turkey)

    NASA Astrophysics Data System (ADS)

    Bobrowska, Alicja; Domonik, Andrzej

    2015-09-01

    In constructions, the usefulness of modern technical diagnostics of stone as a raw material requires predicting the effects of long-term environmental impact of its qualities and geomechanical properties. The paper presents geomechanical research enabling presentation of the factors for strength loss of the stone and forecasting the rate of development of destructive phenomena on the stone structure on a long-time basis. As research material Turkish travertines were selected from the Denizli-Kaklık Basin (Pamukkale and Hierapolis quarries), which have been commonly used for centuries in global architecture. The rock material was subjected to testing of the impact of various environmental factors, as well as European standards recommended by the author of the research program. Their resistance to the crystallization of salts from aqueous solutions and the effects of SO2, as well as the effect of frost and high temperatures are presented. The studies allowed establishing the following quantitative indicators: the ultrasonic waves index (IVp) and the strength reduction index (IRc). Reflections on the assessment of deterioration effects indicate that the most active factors decreasing travertine resistance in the aging process include frost and sulphur dioxide (SO2). Their negative influence is particularly intense when the stone material is already strongly weathered.

  18. Effect of reduction in yeast and enzyme concentrations in a simultaneous- saccharification-and-fermentation-based bioethanol process: technical and economic evaluation.

    PubMed

    Wingren, Anders; Galbe, Mats; Roslander, Christian; Rudolf, Andreas; Zacchi, Guido

    2005-01-01

    The ethanol production cost in a simultaneous saccharification and fermentation-based bioethanol process is influenced by the requirements for yeast production and for enzymes. The main objective of this study was to evaluate--technically and economically--the influence of these two factors on the production cost. A base case with 5 g/L of baker's yeast and an initial concentration of water-insoluble solids of 5% resulted in an experimental yield of 85%. When these data were implemented in Aspen Plus, yeast was assumed to be produced from sugars in the hydrolysate, reducing the overall ethanol yield to 69%. The ethanol production cost was 4.80 SEK/L (2.34 US$/gal). When adapted yeast was used at 2 g/L, an experimental yield of 74% was achieved and the estimated ethanol production cost was the same as in the base case. A 50% reduction in enzyme addition resulted in an increased production cost, to 5.06 SEK/L (2.47 US$/gal) owing to reduced ethanol yield.

  19. 2009 PILOT SCALE FLUIDIZED BED STEAM REFORMING TESTING USING THE THOR (THERMAL ORGANIC REDUCTION) PROCESS: ANALYTICAL RESULTS FOR TANK 48H ORGANIC DESTRUCTION - 10408

    SciTech Connect

    Williams, M.; Jantzen, C.; Burket, P.; Crawford, C.; Daniel, G.; Aponte, C.; Johnson, C.

    2009-12-28

    TTT steam reforming process ability to destroy organics in the Tank 48 simulant and produce a soluble carbonate waste form. The ESTD was operated at varying feed rates and Denitration and Mineralization Reformer (DMR) temperatures, and at a constant Carbon Reduction Reformer (CRR) temperature of 950 C. The process produced a dissolvable carbonate product suitable for processing downstream. ESTD testing was performed in 2009 at the Hazen facility to demonstrate the long term operability of an integrated FBSR processing system with carbonate product and carbonate slurry handling capability. The final testing demonstrated the integrated TTT FBSR capability to process the Tank 48 simulant from a slurry feed into a greater than 99.9% organic free and primarily dissolved carbonate FBSR product slurry. This paper will discuss the SRNL analytical results of samples analyzed from the 2008 and 2009 THOR{reg_sign} steam reforming ESTD performed with Tank 48H simulant at HRI in Golden, Colorado. The final analytical results will be compared to prior analytical results from samples in terms of organic, nitrite, and nitrate destruction.

  20. Reduction of N2O and NO generation in anaerobic-aerobic (low dissolved oxygen) biological wastewater treatment process by using sludge alkaline fermentation liquid.

    PubMed

    Zhu, Xiaoyu; Chen, Yinguang

    2011-03-15

    This paper reported an efficient method to significantly reduce nitrous oxide (N(2)O) and nitric oxide (NO) generation in anaerobic-aerobic (low dissolved oxygen) processes. It was found that by the use of waste-activated sludge alkaline fermentation liquid as the synthetic wastewater-carbon source, compared with the commonly used carbon source in the literature (e.g., acetic acid), the generation of N(2)O and NO was reduced by 68.7% and 50.0%, respectively, but the removal efficiencies of total phosphorus (TP) and total nitrogen (TN) were improved. Both N(2)O and NO were produced in the low dissolved oxygen (DO) stage, and the use of sludge fermentation liquid greatly reduced their generation from the denitrification. The presences of Cu(2+) and propionic acid in fermentation liquid were observed to play an important role in the reduction of N(2)O and NO generation. The analysis of the activities of denitrifying enzymes suggested that sludge fermentation liquid caused the significant decrease of both nitrite reductase activity to NO reductase activity ratio and NO reductase activity to N(2)O reductase activity ratio, which resulted in the lower generation of NO and N(2)O. Fluorescence in situ hybridization analysis indicated that the number of glycogen accumulating bacteria, which was reported to be relevant to nitrous oxide generation, in sludge fermentation liquid reactor was much lower than that in acetic acid reactor. The quantitative detection of the nosZ gene, encoding nitrous oxide reductase, showed that the use of fermentation liquid increased the number of bacteria capable of reducing N(2)O to N(2). The feasibility of using sludge fermentation liquid to reduce NO and N(2)O generation in an anaerobic-low DO process was finally confirmed for a municipal wastewater.

  1. Treatment of hexavalent chromium in chromite ore processing solid waste using a mixed reductant solution of ferrous sulfate and sodium dithionite.

    PubMed

    Su, Chunming; Ludwig, Ralph D

    2005-08-15

    We investigated a method for delivering ferrous iron into the subsurface to enhance chemical reduction of Cr(VI) in chromite ore processing solid waste (COPSW) derived from the production of ferrochrome alloy. The COPSW is characterized by high pH (8.5-11.5) and high Cr(VI) concentrations in the solid phase (up to 550 mg kg(-1)) and dissolved phase (3-57 mg L(-1)). The dominant solid-phase minerals are forsterite (Mg2SiO4), brucite (Mg-(OH)2), and hydrocalumite [Ca4(Al, Fe)2(OH)12X x 6H2O), X = (OH)2(2-), SO4(2-), CrO4(2-)]. The method utilizes FeSO4 in combination with Na2S2O4 to inhibit oxidation and precipitation of the ferrous iron, thereby preventing well and formation clogging. Laboratory batch tests using a 0.05 M FeSO4 + 0.05 M Na2S2O4 solution indicated effective treatment of both dissolved and solid-phase Cr(VI). Contrary to treatments with FeSO4 and FeCl2 alone, the combination resulted in both complete removal of Cr(VI) from solution and sustained Fe(ll) concentrations in solution after a 24 h period. A field test involving injection of 5700 L of a 0.07 M FeSO4 + 0.07 M Na2S2O4 solution into a COPSW saturated zone (pH 11.5) indicated no well and formation clogging during injection. Examination of a core collected 0.46 m from the injection well following injection indicated effective treatment of the solid phase Cr(VI) based on analysis of water, phosphate solution, and high temperature alkaline extracts. The combined reductant solution also imparted a residual treatment capacity to the COPSW allowing for subsequent treatment of dissolved phase Cr(VI); however, dissemination of the iron in the highly alkaline environment appeared to be impeded by the inability to sufficiently lower the pH with distance from the injection well to avoid precipitation of Fe(OH)2 and likely also FeCO3. Injection of a 0.2 M FeSO4 + 0.2 M Na2S2O4 solution into another COPSW saturated zone (pH 9) indicated much more effective dissemination of the injected iron.

  2. Microbial reductive dehalogenation.

    PubMed Central

    Mohn, W W; Tiedje, J M

    1992-01-01

    A wide variety of compounds can be biodegraded via reductive removal of halogen substituents. This process can degrade toxic pollutants, some of which are not known to be biodegraded by any other means. Reductive dehalogenation of aromatic compounds has been found primarily in undefined, syntrophic anaerobic communities. We discuss ecological and physiological principles which appear to be important in these communities and evaluate how widely applicable these principles are. Anaerobic communities that catalyze reductive dehalogenation appear to differ in many respects. A large number of pure cultures which catalyze reductive dehalogenation of aliphatic compounds are known, in contrast to only a few organisms which catalyze reductive dehalogenation of aromatic compounds. Desulfomonile tiedjei DCB-1 is an anaerobe which dehalogenates aromatic compounds and is physiologically and morphologically unusual in a number of respects, including the ability to exploit reductive dehalogenation for energy metabolism. When possible, we use D. tiedjei as a model to understand dehalogenating organisms in the above-mentioned undefined systems. Aerobes use reductive dehalogenation for substrates which are resistant to known mechanisms of oxidative attack. Reductive dehalogenation, especially of aliphatic compounds, has recently been found in cell-free systems. These systems give us an insight into how and why microorganisms catalyze this activity. In some cases transition metal complexes serve as catalysts, whereas in other cases, particularly with aromatic substrates, the catalysts appear to be enzymes. Images PMID:1406492

  3. Integrating sodium reduction strategies in the procurement process and contracting of food venues in the County of Los Angeles government, 2010-2012.

    PubMed

    Cummings, Patricia L; Kuo, Tony; Gase, Lauren N; Mugavero, Kristy

    2014-01-01

    Since sodium is ubiquitous in the food supply, recent approaches to sodium reduction have focused on increasing the availability of lower-sodium products through system-level and environmental changes. This article reviews integrated efforts by the Los Angeles County Sodium Reduction Initiative to implement these strategies at food venues in the County of Los Angeles government. The review used mixed methods, including a scan of the literature, key informant interviews, and lessons learned during 2010-2012 to assess program progress. Leveraging technical expertise and shared resources, the initiative strategically incorporated sodium reduction strategies into the overall work plan of a multipartnership food procurement program in Los Angeles County. To date, 3 County departments have incorporated new or updated nutrition requirements that included sodium limits and other strategies. The strategic coupling of sodium reduction to food procurement and general health promotion allowed for simultaneous advancement and acceleration of the County's sodium reduction agenda.

  4. Harm reduction

    PubMed Central

    Normand, Jacques; Li, Jih-Heng; Thomson, Nicholas; Jarlais, Don Des

    2014-01-01

    The “Harm Reduction” session was chaired by Dr. Jacques Normand, Director of the AIDS Research Program of the U.S. National Institute on Drug Abuse. The three presenters (and their presentation topics) were: Dr. Don Des Jarlais (High Coverage Needle/Syringe Programs for People Who Inject Drugs in Low and Middle Income Countries: A Systematic Review), Dr. Nicholas Thomson (Harm Reduction History, Response, and Current Trends in Asia), and Dr. Jih-Heng Li (Harm Reduction Strategies in Taiwan). PMID:25278732

  5. Waste Reduction.

    ERIC Educational Resources Information Center

    Bray, Marilyn; And Others

    1996-01-01

    Presents activities that focus on waste reduction in the school and community. The ideas are divided into grade level categories. Sample activities include Techno-Trash, where children use tools to take apart broken appliances or car parts, then reassemble them or build new creations. Activities are suggested for areas including language arts and…

  6. Degradation mechanisms and kinetic studies for the treatment of X-ray contrast media compounds by advanced oxidation/reduction processes.

    PubMed

    Jeong, Joonseon; Jung, Jinyoung; Cooper, William J; Song, Weihua

    2010-08-01

    The presence of iodinated X-ray contrast media compounds (ICM) in surface and ground waters has been reported. This is likely due to their biological inertness and incomplete removal in wastewater treatment processes. The present study reports partial degradation mechanisms based on elucidating the structures of major reaction by-products using gamma-irradiation and LC-MS. Studies conducted at concentrations higher than observed in natural waters is necessary to elucidate the reaction by-product structures and to develop destruction mechanisms. To support these mechanistic studies, the bimolecular rate constants for the reaction of OH and e(-)(aq) with one ionic ICM (diatrizoate), four non-ionic ICM (iohexol, iopromide, iopamidol, and iomeprol), and the several analogues of diatrizoate were determined. The absolute bimolecular reaction rate constants for diatrizoate, iohexol, iopromide, iopamidol, and iomeprol with OH were (9.58 +/- 0.23)x10(8), (3.20 +/- 0.13)x10(9), (3.34 +/- 0.14)x10(9), (3.42 +/- 0.28)x10(9), and (2.03 +/- 0.13) x 10(9) M(-1) s(-1), and with e(-)(aq) were (2.13 +/- 0.03)x10(10), (3.35 +/- 0.03)x10(10), (3.25 +/- 0.05)x10(10), (3.37 +/- 0.05)x10(10), and (3.47 +/- 0.02) x 10(10) M(-1) s(-1), respectively. Transient spectra for the intermediates formed by the reaction of OH were also measured over the time period of 1-100 micros to better understand the stability of the radicals and for evaluation of reaction rate constants. Degradation efficiencies for the OH and e(-)(aq) reactions with the five ICM were determined using steady-state gamma-radiolysis. Collectively, these data will form the basis of kinetic models for application of advanced oxidation/reduction processes for treating water containing these compounds.

  7. The Mental Health Association of San Francisco Partner Organizations Meet Their Goals in Stigma Reduction Efforts: Results of a Qualitative Evaluation of the Technical Assistance Process.

    PubMed

    Cerully, Jennifer L; Collins, Rebecca L; Wong, Eunice C; Yu, Jennifer

    2016-01-29

    This article describes the results of RAND's evaluation of the San Francisco-based Center for Dignity, Recovery, and Empowerment's technical assistance program for stigma-reduction programs through interviews with community-partner participants.

  8. Reduction of image noise in low tube current dynamic CT myocardial perfusion imaging using HYPR processing: A time-attenuation curve analysis

    PubMed Central

    Speidel, Michael A.; Bateman, Courtney L.; Tao, Yinghua; Raval, Amish N.; Hacker, Timothy A.; Reeder, Scott B.; Van Lysel, Michael S.

    2013-01-01

    Purpose: This study describes a HighlY constrained backPRojection (HYPR) image processing method for the reduction of image noise in low tube current time-resolved CT myocardial perfusion scans. The effect of this method on myocardial time-attenuation curve noise and fidelity is evaluated in an animal model, using varying levels of tube current. Methods: CT perfusion scans of four healthy pigs (42–59 kg) were acquired at 500, 250, 100, 50, 25, and 10 mA on a 64-slice scanner (4 cm axial coverage, 120 kV, 0.4 s/rotation, 50 s scan duration). For each scan a sequence of ECG-gated images centered on 75% R-R was reconstructed using short-scan filtered back projection (FBP). HYPR processing was applied to the scans acquired at less than 500 mA using parameters designed to maintain the voxel noise level in the 500-mA FBP images. The processing method generates a series of composite images by averaging over a sliding time window and then multiplies the composite images by weighting images to restore temporal fidelity to the image sequence. HYPR voxel noise relative to FBP noise was measured in AHA myocardial segment numbers 1, 5, 6, and 7 at each mA. To quantify the agreement between HYPR and FBP time-attenuation curves (TACs), Bland-Altman analysis was performed on TACs measured in full myocardial segments. The relative degree of TAC fluctuation in smaller subvolumes was quantified by calculating the root mean square deviation of a TAC about the gamma variate curve fit to the TAC data. Results: HYPR image sequences were produced using 2, 7, and 20 beat composite windows for the 250, 100, and 50 mA scans, respectively. At 25 and 10 mA, all available beats were used in the composite (41–60; average 50). A 7-voxel-wide 3D cubic filter kernel was used to form weighting images. The average ratio of HYPR voxel noise to 500-mA FBP voxel noise was 1.06, 1.10, 0.97, 1.11, and 2.15 for HYPR scans at 250, 100, 50, 25, and 10 mA. The average limits-of-agreement between HYPR and

  9. Reduction Corporoplasty

    PubMed Central

    Hakky, Tariq S.; Martinez, Daniel; Yang, Christopher; Carrion, Rafael E.

    2015-01-01

    Objective Here we present the first video demonstration of reduction corporoplasty in the management of phallic disfigurement in a 17 year old man with a history sickle cell disease and priapism. Introduction Surgical management of aneurysmal dilation of the corpora has yet to be defined in the literature. Materials and Methods: We preformed bilateral elliptical incisions over the lateral corpora as management of aneurysmal dilation of the corpora to correct phallic disfigurement. Results The patient tolerated the procedure well and has resolution of his corporal disfigurement. Conclusions Reduction corporoplasty using bilateral lateral elliptical incisions in the management of aneurysmal dilation of the corpora is a safe an feasible operation in the management of phallic disfigurement. PMID:26005988

  10. Nitrate reduction

    DOEpatents

    Dziewinski, Jacek J.; Marczak, Stanislaw

    2000-01-01

    Nitrates are reduced to nitrogen gas by contacting the nitrates with a metal to reduce the nitrates to nitrites which are then contacted with an amide to produce nitrogen and carbon dioxide or acid anions which can be released to the atmosphere. Minor amounts of metal catalysts can be useful in the reduction of the nitrates to nitrites. Metal salts which are formed can be treated electrochemically to recover the metals.

  11. Reductions in Natural Microbial Flora, Nonpathogenic Escherichia coli , and Pathogenic Salmonella on Jalapeno Peppers Processed in a Commercial Antimicrobial Cabinet: A Pilot Plant Trial.

    PubMed

    Adler, Jeremy M; Cain-Helfrich, Erin D; Shen, Cangliang

    2016-11-01

    This experiment aimed to validate the use of antimicrobial solutions in a spray cabinet to inactivate natural microbial flora, nonpathogenic Escherichia coli , and Salmonella on jalapeno peppers. Jalapeno peppers, uninoculated or inoculated with a five-strain mixture of rifampin-resistant E. coli (3.9 log CFU/g) or novobiocin- and nalidixic acid-resistant Salmonella (4.2 log CFU/g), were passed through a commercial antimicrobial cabinet containing both a top and bottom bar spraying (1.38 bar and 2 liters/min) water, sodium hypochlorite (50 ppm), sodium hypochlorite with pH adjusted to 6.7, peroxyacetic acid (PAA; 80 ppm), PAA with pH adjusted to 6.7, lactic with citric acid (1%), lactic with citric acid with sodium lauryl sulfate (1,200 ppm), or chlorine dioxide (5 ppm). Bacteria were recovered in 0.1% buffered peptone water plus 0.1% sodium thiosulfate, which was followed by spread plating onto tryptic soy agar (TSA), TSA plus rifampin (100 μg/ml), and TSA plus novobiocin (25 μg/ml) and nalidixic acid (20 μg/ml). There were no significant differences (P ≥ 0.05) in recovered natural microbial flora, E. coli , and Salmonella populations between untreated peppers (3.5 to 4.2 log CFU/g) and peppers treated with water (3.4 to 3.8 log CFU/g). Significantly fewer (P < 0.05) natural microbial flora, E. coli , and Salmonella populations were recovered on the peppers after they were treated with a majority of the antimicrobials applied in the commercial antimicrobial cabinet. The largest population reduction was observed on peppers sprayed with PAA. Interestingly, the pH adjustment did not make a difference (P ≥ 0.05) in the recovered bacterial populations. These results validate the use of a commercial antimicrobial spray cabinet, and they are useful for developing application protocols for antimicrobials to control Salmonella during the postharvest processing of jalapeno peppers.

  12. Low-frequency noise reduction in vertical MOSFETs having tunable threshold voltage fabricated with 60 nm CMOS technology on 300 mm wafer process

    NASA Astrophysics Data System (ADS)

    Imamoto, Takuya; Ma, Yitao; Muraguchi, Masakazu; Endoh, Tetsuo

    2015-04-01

    In this paper, DC and low-frequency noise (LFN) characteristics have been investigated with actual measurement data in both n- and p-type vertical MOSFETs (V-MOSFETs) for the first time. The V-MOSFETs which was fabricated on 300 mm bulk silicon wafer process have realized excellent DC performance and a significant reduction of flicker (1/f) noise. The measurement results show that the fabricated V-MOSFETs with 60 nm silicon pillar and 100 nm gate length achieve excellent steep sub-threshold swing (69 mV/decade for n-type and 66 mV/decade for p-type), good on-current (281 µA/µm for n-type 149 µA/µm for p-type), low off-leakage current (28.1 pA/µm for n-type and 79.6 pA/µm for p-type), and excellent on-off ratio (1 × 107 for n-type and 2 × 106 for p-type). In addition, it is demonstrated that our fabricated V-MOSFETs can control the threshold voltage (Vth) by changing the channel doping condition, which is the useful and low-cost technique as it has been widely used in the conventional bulk planar MOSFET. This result indicates that V-MOSFETs can control Vth more finely and flexibly by the combined the use of the doping technique with other techniques such as work function engineering of metal-gate. Moreover, it is also shown that V-MOSFETs can suppress 1/f noise (L\\text{gate}WS\\text{Id}/I\\text{d}2 of 10-13-10-11 µm2/Hz for n-type and 10-12-10-10 µm2/Hz for p-type) to one or two order lower level than previously reported nanowire type MOSFET, FinFET, Tri-Gate, and planar MOSFETs. The results have also proved that both DC and 1/f noise performances are independent from the bias voltage which is applied to substrate or well layer. Therefore, it is verified that V-MOSFETs can eliminate the effects from substrate or well layer, which always adversely affects the circuit performances due to this serial connection.

  13. Production of aluminum-silicon alloy and ferrosilicon and commercial-purity aluminum by the direct-reduction process. Third annual technical report, 1980 January 1-1980 December 31

    SciTech Connect

    Bruno, M.J.

    1981-01-01

    Progress on the program to demonstrate the technical feasibility of a pilot-sized Direct Reduction Process for producing aluminium and aluminium-silicon alloy is reported for Phase C. Progress is reported on reduction including the following tasks: supply burden material; burden beneficiation; effects of pilot operating parameters; pilot modifications; reactor scale-up design; calculating heat and mass balance; processing mathematical modeling; effects of process variables; information on supportive analytical, phase identification, and mechanical engineering data. Progress on alloy purification is reported in the following tasks: pilot unit installation; effects of pilot operating parameters; pilot unit modifications; and supportive mechanical engineering. Progress on purification to commercial grade aluminum is reported on: pilot unit installation; effects of pilot operating parameters; pilot unit modifications; support pilot operations; and supportive expended man-hours. Plans for Phase D are noted. (MCW)

  14. Characterization and study of reduction and sulfurization processing in phase transition from molybdenum oxide (MoO2) to molybdenum disulfide (MoS2) chalcogenide semiconductor nanoparticles prepared by one-stage chemical reduction method

    NASA Astrophysics Data System (ADS)

    Shomalian, K.; Bagheri-Mohagheghi, M.-M.; Ardyanian, M.

    2017-01-01

    In this research, molybdenum disulfide (MoS2) nanoparticles were prepared by chemical reduction method using MoO3 and thiourea as a precursor. The physical properties of the synthesized MoO2-MoS2 nanoparticles annealed at different temperatures of 200, 300, 750 °C have been investigated, before and after exposure to sulfur vapor. The nanostructure of nanoparticles has been characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM) analyses and UV-Vis spectrophotometer. The X-ray diffraction analysis showed the formation of MoS2 single phase at annealing temperature of 750 °C in the presence of sulfur vapor. The Raman spectrum of the nanoparticles revealed that the formation of MoS2 at 750 °C after annealing in sulfur vapor. The values of band gap were obtained in the range of 3.64-3.17 eV and 3.47-1.95 eV for MoS2 nanoparticles before and after exposure to sulfur vapor, respectively. According to SEM images, the grain size decreases with increasing annealing temperature up to 750 °C. Also, nanoplate-nanoparticles of MoS2 are formed at annealing temperature of 200-750 °C. The TEM images of MoS2 nanoparticles at T a = 750 °C confirm that the nanoparticles have a homogeneous distribution with a hexagonal structure. The FTIR spectra of the MoS2 nanoparticles showed the peaks at about 467 cm-1 belong to the characteristic bands of Mo-S.

  15. Sequential Process Combination of Photocatalytic Oxidation and Dark Reduction for the Removal of Organic Pollutants and Cr(VI) using Ag/TiO2.

    PubMed

    Choi, Yeoseon; Koo, Min Seok; Bokare, Alok D; Kim, Dong-Hyo; Bahnemann, Detlef W; Choi, Wonyong

    2017-03-09

    We investigated a sequential photocatalysis-dark reaction, wherein organic pollutants were degraded on Ag/TiO2 under UV irradiation and the dark reduction of hexavalent chromium (Cr(VI)) was subsequently followed. The photocatalytic oxidation of 4-chlorophenol (4-CP), a test organic substrate, induced the generation of degradation intermediates and the storage of electrons in Ag/TiO2 which were then utilized for reducing Cr(VI) in the post-irradiation period. The dark reduction efficiency of Cr(VI) was much higher with Ag/TiO2 (87%), compared with bare TiO2 (27%) and Pt/TiO2 (22%). The Cr(VI) removal by Ag/TiO2 (87%) was contributed by adsorption (31%), chemical reduction by intermediates of 4-CP degradation (26%), and reduction by electrons stored in Ag (30%). When formic acid, humic acid or ethanol was used as an alternative organic substrate, the electron storage effect was also observed. The post-irradiation removal of Cr(VI) on Ag/TiO2 continued for hours, which is consistent with the observation that a residual potential persisted on the Ag/TiO2 electrode in the dark whereas little residual potential was observed on bare TiO2 and Pt/TiO2 electrodes. The stored electrons in Ag/TiO2 and their transfer to Cr(VI) were also indicated by the UV-visible absorption spectral change. Moreover, the electrons stored in the pre-irradiated Ag/TiO2 reacted with O2 with showing a sign of low-level OH radical generation in the dark period.

  16. Cochlear implant optimized noise reduction.

    PubMed

    Mauger, Stefan J; Arora, Komal; Dawson, Pam W

    2012-12-01

    Noise-reduction methods have provided significant improvements in speech perception for cochlear implant recipients, where only quality improvements have been found in hearing aid recipients. Recent psychoacoustic studies have suggested changes to noise-reduction techniques specifically for cochlear implants, due to differences between hearing aid recipient and cochlear implant recipient hearing. An optimized noise-reduction method was developed with significantly increased temporal smoothing of the signal-to-noise ratio estimate and a more aggressive gain function compared to current noise-reduction methods. This optimized noise-reduction algorithm was tested with 12 cochlear implant recipients over four test sessions. Speech perception was assessed through speech in noise tests with three noise types; speech-weighted noise, 20-talker babble and 4-talker babble. A significant speech perception improvement using optimized noise reduction over standard processing was found in babble noise and speech-weighted noise and over a current noise-reduction method in speech-weighted noise. Speech perception in quiet was not degraded. Listening quality testing for noise annoyance and overall preference found significant improvements over the standard processing and over a current noise-reduction method in speech-weighted and babble noise types. This optimized method has shown significant speech perception and quality improvements compared to the standard processing and a current noise-reduction method.

  17. Reaction Times of Aging Subjects to Monaural Verbal Stimuli: Some Evidence for a Reduction in Right-Hemisphere Linguistic Processing Capacity.

    ERIC Educational Resources Information Center

    Rastatter, Michael P.; Lawson-Brill, Cindy

    1987-01-01

    Effects of advanced aging on hemispheric organization for linguistic processing was investigated with 24 geriatric subjects. Findings indicated that only the left hemisphere was used in language processing, suggesting that right hemispheric language processing ability is inhibited in the elderly. (Author/DB)

  18. Principal Components as a Data Reduction and Noise Reduction Technique

    NASA Technical Reports Server (NTRS)

    Imhoff, M. L.; Campbell, W. J.

    1982-01-01

    The potential of principal components as a pipeline data reduction technique for thematic mapper data was assessed and principal components analysis and its transformation as a noise reduction technique was examined. Two primary factors were considered: (1) how might data reduction and noise reduction using the principal components transformation affect the extraction of accurate spectral classifications; and (2) what are the real savings in terms of computer processing and storage costs of using reduced data over the full 7-band TM complement. An area in central Pennsylvania was chosen for a study area. The image data for the project were collected using the Earth Resources Laboratory's thematic mapper simulator (TMS) instrument.

  19. Microbial reduction of SO{sub 2} and NO{sub x} as a means of by-product recovery/disposal from regenerable processes for the desulfurization of flue gas. Technical progress report, March 11, 1993--June 11, 1993

    SciTech Connect

    Sublette, K.L.

    1993-11-01

    There are two basic approaches to addressing the problem of SO{sub 2} and NO{sub x} emissions: (1) desulfurize (and denitrogenate) the feedstock prior to or during combustion; or (2) scrub the resultant SO{sub 2} and oxides of nitrogen from the boiler flue gases. The flue gas processing alternative has been addressed in this project via microbial reduction of SO{sub 2} and NO{sub x} by sulfate-reducing bacteria

  20. Reduction-Fired Seedpod Bowls.

    ERIC Educational Resources Information Center

    Beyke, Rod

    2001-01-01

    Focuses on a reduction-firing process with an aim of producing high-quality blackware similar to the black-on-black pottery of Maria Martinez and other American Indian potters. Includes a lesson on creating reduction-fired seedpod bowls, lists of instructional resources and materials, and the objectives and evaluation. (CMK)

  1. Development of Waste Reduction System of Wastewater Treatment Process Using a Moss: Production of Useful Materials from Remainder of a Moss

    NASA Astrophysics Data System (ADS)

    Fumihisa, Kobayashi

    Landfill leachate pollution presents a serious environmental problem. It would be valuable to develop a sustainable method, one that is inexpensive and requires little energy, to eliminate the pollution and dispose of the waste. In a previous study, we reported the results of a leachate treatment for landfills in which we relied on the moss, Scopelophia cataractae, to support a sustainable method of waste reduction. In this study, for the development of a waste reduction system of landfill leachate treatment, we attempted to produce zinc as useful metal and ethanol as fuel from the remainder of moss after wastewater treatment. Steam explosions, which were used as physicochemical pretreatments to expose the raw material to saturated steam under high pressure and temperature, were used to pretreat the moss. By electrolysis, zinc recovered, and the maximum zinc recovery after wastewater treatment was 0.504 at 2.0 MPa steam pressure (211 °C) and 5 min steaming time. After that time, by simultaneous saccharification and fermentation using a Meicelase and Saccharomyces cerevisiae AM12, 0.42 g dm-3 of the maximum ethanol concentration was produced from 10 g dm-3 of exploded moss at 2.5 MPa steam pressure (223 °C) and 1 min steaming time.

  2. Somatic reduction in cycads.

    PubMed

    Storey, W B

    1968-02-09

    Recurrent somatic reduction is a normal ontogenetic process in apogeotropic roots of cycads, which develop into dichotomously branching coralloid masses. The reduced cells make up part of a ring of differentiated cortical tissue lying midway between the pericycle and the epidermis; they serve as fillers among the large cells and become charged with slime. The differentiated tissue is colonized by a species of blue-green algae.

  3. Study of an Energy Storage and Recovery Concept Based on the W/WO3 Redox Reaction: Part I. Kinetic Study and Modeling of the WO3 Reduction Process for Energy Storage

    NASA Astrophysics Data System (ADS)

    Haboury, Romain; Pal, Uday B.; Zink, Peter A.; Gopalan, Srikanth; Basu, Soumendra N.

    2012-08-01

    Energy storage and recovery using the redox reaction of tungsten/tungsten-oxide is proposed. The system will store energy as tungsten metal by reducing the tungsten oxide with hydrogen. Thereafter, steam will be used to reoxidize the metal and recover the hydrogen. The volumetric energy density of W for storing hydrogen by this process is 21 kWh/L based on the lower heating value (LHV) of hydrogen. The main objective of this investigation was to study the kinetics of the reduction process of tungsten oxide (WO3) and determine the optimum parameters for rapid and complete reduction. Theoretical treatment of isothermal kinetics has been extended in the current work to the reduction of tungsten oxide in powder beds. Experiments were carried out using a thermogravimetric technique under isothermal conditions at different temperatures. The reaction at 1073 K (800 °C) was found to take place in the following sequence: WO3 → WO2.9 → WO2.72 → WO2 → W. Expressions for the last three reaction rate constants and activation energies have been calculated based on the fact that the intermediate reactions proceed as a front moving at a certain velocity while the first reaction occurs in the entire bulk of the oxide. The gas-solid reaction kinetics were modeled mathematically in terms of the process parameters. This model of the reduction has been found to be accurate for bed heights above 1.5 mm and hydrogen partial pressures greater than 3 pct, which is ideal for implementing the energy storage concept.

  4. Using a Systematic Conceptual Model for a Process Evaluation of a Middle School Obesity Risk-Reduction Nutrition Curriculum Intervention: "Choice, Control & Change"

    ERIC Educational Resources Information Center

    Lee, Heewon; Contento, Isobel R.; Koch, Pamela

    2013-01-01

    Objective: To use and review a conceptual model of process evaluation and to examine the implementation of a nutrition education curriculum, "Choice, Control & Change", designed to promote dietary and physical activity behaviors that reduce obesity risk. Design: A process evaluation study based on a systematic conceptual model. Setting: Five…

  5. Analysis of metal Bioleaching from thermal power plant fly ash by Aspergillus niger 34770 culture supernatant and reduction of phytotoxicity during the process.

    PubMed

    Jadhav, Umesh U; Hocheng, Hong

    2015-01-01

    Aspergillus niger culture supernatant is used for bioleaching process. Before starting bioleaching process, fly ash was washed with distilled water. This removed 100 % sodium, 47 % (±0.45) boron, 38.07 % (±0.12) calcium, 29.89 % (±0.78) magnesium, and 11.8 % (±0.05) potassium. The pH was reduced from 10.5 to 8.5 after water washing. During bioleaching process, around 100 % metal removal was achieved in 4 h for all metals except chromium 93 % (±1.18), nickel 83 % (±0.32), arsenic 78 % (±0.52), and lead 70 % (±0.20). The process parameters including temperature, shaking speed, and solid/liquid ratio were optimized for bioleaching process. Experiments were conducted to evaluate effect of fly ash on growth of mung bean (Vigna radiata). At 20 g/100 ml fly ash concentration no germination of V. radiata seeds was observed. With an increasing concentration of untreated fly ash, a gradual decrease in root/shoot length was observed. After bioleaching process 78 % (±0.19) germination of V. radiata was observed with 20 g/100 ml fly ash. This study will help to develop an efficient process to remove the toxic metals from fly ash.

  6. The combination of coagulation, acid cracking and Fenton-like processes for olive oil mill wastewater treatment: phytotoxicity reduction and biodegradability augmentation.

    PubMed

    Yazdanbakhsh, Ahmadreza; Mehdipour, Fayyaz; Eslami, Akbar; Maleksari, Hajar Sharifi; Ghanbari, Farshid

    2015-01-01

    Olive oil mill wastewater (OOMW) is one of the most important industrial wastewaters in the world due to high organic load and phenolic compounds. In this study, an integration of three processes including coagulation, acid cracking and Fenton-like was evaluated to treat OOMW. The performance of alum, ferric chloride and polyaluminum chloride was studied as coagulants. Among coagulants, ferric chloride showed the best results in comparison with the others. Coagulation process with FeCl3 removed 91.2% chemical oxygen demand (COD), 91.3% phenol, 98.9% total suspended solids and 99.2% turbidity at condition of pH = 6 and 3,000 mg/L coagulant dosage. Acid cracking process following the coagulation process with ferric chloride could slightly degrade organic compounds and provided suitable condition for the next process. Fenton-like process with zero valent iron (ZVI) was applied after coagulation and acid cracking. The optimal removal efficiency was achieved by Fenton-like process which was accomplished in condition of 7 g/L ZVI, 1,000 mg/L H2O2 and 180 min reaction time. The biodegradability of final effluent of this integration was improved significantly and biochemical oxygen demand5/COD value increased from 0.14 to 0.83. The results of germination tests revealed that phytotoxicity of the final effluent decreased.

  7. Laser surface texturing of cast iron steel: dramatic edge burr reduction and high speed process optimisation for industrial production using DPSS picosecond lasers

    NASA Astrophysics Data System (ADS)

    Bruneel, David; Kearsley, Andrew; Karnakis, Dimitris

    2015-07-01

    In this work we present picosecond DPSS laser surface texturing optimisation of automotive grade cast iron steel. This application attracts great interest, particularly in the automotive industry, to reduce friction between moving piston parts in car engines, in order to decrease fuel consumption. This is accomplished by partially covering with swallow microgrooves the inner surface of a piston liner and is currently a production process adopting much longer pulse (microsecond) DPSS lasers. Lubricated interface conditions of moving parts require from the laser process to produce a very strictly controlled surface topography around the laser formed grooves, whose edge burr height must be lower than 100 nm. To achieve such a strict tolerance, laser machining of cast iron steel was investigated using an infrared DPSS picosecond laser (10ps duration) with an output power of 16W and a repetition rate of 200 kHz. The ultrashort laser is believed to provide a much better thermal management of the etching process. All studies presented here were performed on flat samples in ambient air but the process is transferrable to cylindrical geometry engine liners. We will show that reducing significantly the edge burr below an acceptable limit for lubricated engine production is possible using such lasers and remarkably the process window lies at very high irradiated fluences much higher that the single pulse ablation threshold. This detailed experimental work highlights the close relationship between the optimised laser irradiation conditions as well as the process strategy with the final size of the undesirable edge burrs. The optimised process conditions are compatible with an industrial production process and show the potential for removing extra post)processing steps (honing, etc) of cylinder liners on the manufacturing line saving time and cost.

  8. Formation of colloidal silver nanoparticles stabilized by Na+-poly(gamma-glutamic acid)-silver nitrate complex via chemical reduction process.

    PubMed

    Yu, Da-Guang

    2007-10-01

    Macromolecular and polyanionic Na(+)-poly(gamma-glutamic acid) (PGA) silver nitrate complex acted as both a metal ion provider and a particle protector to fabricate nanosized silver colloids under chemical reduction by dextrose. The formation and size of particles have been characterized from transmission electron microscopy (TEM), dynamic light scattering analysis and UV-vis spectrophotometer. The results showed that the average particle size was 17.2+/-3.4 to 37.3+/-5.5 nm, apparently depending on the complex concentration. It was found that the rate constant and conversion of silver nanoparticles were proportional to the concentration of PGA. The growth mechanism of nanosized silver colloid was fully discussed. In addition, the in vitro cytotoxicity evaluated by L929 fibroblasts proliferation and antibacterial activity against Gram-positive strain (methicillin-resistant S. aureus (MRSA)) and Gram-negative strain (P. aeruginosa) bacteria have been assessed.

  9. Influence of relative rolling reduction and thickness layers bimetallic plate at the non-uniformity of the strain after rolling process

    NASA Astrophysics Data System (ADS)

    Rydz, D.; Stradomski, G.; Dyja, H.

    2017-02-01

    In the article were made numerical and laboratory tests of two-layers rolling process sheet composed of Al99,8 + M1E. Laboratory tests made with use of 150 mm diameter working rolls mill. To the modeling of the bimetallic plate rolling were taken the FEM Forge 2D software based on the theory of plasticity and MathCad program (in which to the rolling process modeling were used the mathematical model developed in the work [5] based on the theory of viscoelasticity). The aim of study was to determine the influence of layer thickness HT0/HM0 and relative deformation ε on the uneven distribution of steel sheet deformation after rolling process. Calculations based on the theory of viscoelasticity allowed additionally take into account the impact of the delayed effects of the variation of viscoelastic deformation of layers of the bimetallic plate rolling process.

  10. Nagel on reduction.

    PubMed

    Sarkar, Sahotra

    2015-10-01

    This paper attempts a critical reappraisal of Nagel's (1961, 1970) model of reduction taking into account both traditional criticisms and recent defenses. This model treats reduction as a type of explanation in which a reduced theory is explained by a reducing theory after their relevant representational items have been suitably connected. In accordance with the deductive-nomological model, the explanation is supposed to consist of a logical deduction. Nagel was a pluralist about both the logical form of the connections between the reduced and reducing theories (which could be conditionals or biconditionals) and their epistemological status (as analytic connections, conventions, or synthetic claims). This paper defends Nagel's pluralism on both counts and, in the process, argues that the multiple realizability objection to reductionism is misplaced. It also argues that the Nagel model correctly characterizes reduction as a type of explanation. However, it notes that logical deduction must be replaced by a broader class of inferential techniques that allow for different types of approximation. Whereas Nagel (1970), in contrast to his earlier position (1961), recognized the relevance of approximation, he did not realize its full import for the model. Throughout the paper two case studies are used to illustrate the arguments: the putative reduction of classical thermodynamics to the kinetic theory of matter and that of classical genetics to molecular biology.

  11. Microbial reduction of SO{sub 2} and NO{sub x} as a means of by-product recovery/disposal from regenerable processes for the desulfurization of flue gas. Technical progress report, September 11, 1992--December 11, 1992

    SciTech Connect

    Sublette, K.L.

    1992-12-31

    With the continual increase in the utilization of high sulfur and high nitrogen containing fossil fuels, the release of airborne pollutants into the environment has become a critical problem. The fuel sulfur is converted to SO{sub 2} during combustion. Fuel nitrogen and a fraction of the nitrogen from the combustion air are converted to nitric oxide and nitrogen dioxide, NO{sub x}. For the past five years Combustion Engineering (now Asea Brown Boveri or ABB) and, since 1986, the University of Tulsa (TU) have been investigating the oxidation of H{sub 2}S by the facultatively anaerobic and autotrophic bacterium Thiobacillus denitrificans and have developed a process, concept for the microbial removal of H{sub 2}S from a gas stream the simultaneous removal of SO{sub 2} and NO by D. desulfuricans and T. denitrificans co-cultures and cultures-in-series was demonstrated. These systems could not be sustained due to NO inhibition of D. desulfuricans. However, a preliminary economic analysis has shown that microbial reduction of SO{sub 2} to H{sub 2}S with subsequent conversion to elemental sulfur by the Claus process is both technically and economically feasible if a less expensive carbon and/or energy source can be found. It has also been demonstrated that T. denitrificans can be grown anaerobically on NO(g) as a terminal electron acceptor with reduction to elemental nitrogen. Microbial reduction of NO{sub x} is a viable process concept for the disposal of concentrated streams of NO{sub x} as may be produced by certain regenerable processes for the removal of SO{sub 2} and NO{sub x} from flue gas.

  12. Submicron e-beam lithography process using an overcoating conducting polymer for the reduction of beam charging effects on lithium niobate and quartz

    NASA Astrophysics Data System (ADS)

    Kondek, Christine A.; Poli, Louis C.

    1994-05-01

    This paper presents a processing methodology for direct write E-beam lithography on insulating substrates. Processes suitable for use with negative tone SAL-601-ER7 and positive tone PMMA are presented. Both are three level processes and are used for fabrication of surface acoustic wave (SAW) devices with transducer electrode line space dimensions of 0.7 and 0.4 micron, respectively. The authors method involves spinning a film of a commercially available conductive polymer, known as TQV-501, as the final coating. A Leica Instruments EBMF 10.5 electron beam tool operating at an energy of 30 keV is used to perform lithography. SAW devices were patterned with these processes and then realized by metallization with aluminum via lift-off. A two level positive tone process was used consisting of a film of P(MMA-MAA) followed by a film of PMMA. This is followed by a final spin coating of TQV-501 to provide a discharge medium. The negative tone process consists of a film of SAL-601-ER7 which is followed by a film of polyvinyl alcohol (PVA). A final film layer of TQV-501 is then applied. The PVA serves as both a diffusion barrier to prevent intermixing of the TQV-501 and SAL-601-ER7 during layering and later to prevent stripping the SAL-601-ER7 during the solvent strip of the TQV-501. Patterns are written in reversed tone form on negative resist to provide the proper final positive image tone suitable for lift-off. TQV-501 offers the advantage of simple application via spin coating and a soft bake and easy removal by stripping in solvent.

  13. Demonstration of innovative applications of technology for cost reductions to the CT-121 FGD process. Quarterly report No. 3, October--December 1990

    SciTech Connect

    Not Available

    1991-02-15

    The objective of this project is to demonstrate on a commercial scale several innovative applications of cost-reducing technology to the Chiyoda Thoroughbred-121 (CT-121) process. CT-121 is a second generation flue gas desulfurization (FGD) process which is considered by the Electric Power Research Institute (EPRI) and Southern Company Services (SCS) to be one of the most reliable and lowest cost FGD options for high-sulfur coal-fired utility boiler applications. Demonstrations of the innovative design approaches will further reduce the cost and provide a clear advantage to CT121 relative to competing technology.

  14. Demonstration of innovative applicatiions of technology for cost reductions to the CT-121 FGD process. Quarterly report No. 4, January--March 1991

    SciTech Connect

    Not Available

    1991-05-15

    The objective of this project is to demonstrate on a commercial scale several innovative applications of cost-reducing technology to the Chiyoda Thoroughbred-121 (CT-121) process. CT-121 is a second generation flue gas desulfurization (FGD) process which is considered by the Electric Power Research Institute (EPRI) and Southern Company Services (SCS) to be one of the most reliable and lowest cost FGD options for high-sulfur coal-fired utility boiler applications. Demonstrations of the innovative design approaches will further reduce the cost and provide a clear advantage to CT121 relative to competing technology.

  15. Performance evaluation of the UV/H2O2 process on selected nitrogenous organic compounds: reductions of organic contents vs. corresponding C-, N-DBPs formations.

    PubMed

    Chen, Huei-Wen; Chen, Chia-Yang; Wang, Gen-Shuh

    2011-10-01

    The presence of various organic contaminants in water sources is of concern due to their direct threats to human health and potential to react with disinfectants to form carcinogenic byproducts including trihalomethanes, haloacetic acids and nitrosamines in finished water. This study applied both medium-pressure and low-pressure ultraviolet light coupled with hydrogen peroxide (UV/H2O2) to evaluate its efficacy for degradation of selected nitrogenous organic compounds and corresponding disinfection byproduct (DBP) formation. Six organic compounds were chosen as target precursors based on their nitrogen contents and molecular structures. The results showed that higher oxidation capacity resulted in better reduction of organic matters and DBP formation potentials (DBPFPs). However, insufficient contact time and oxidant doses could lead to a rise of DBPFPs in the early stages of UV/H2O2 reactions. A greater percentage removal was achieved for organic carbon than organic nitrogen after UV/H2O2 treatment, especially for compounds with complicated structure such as diltiazem. During the UV/H2O2 treatment, the intermediate products include tertiary amine, dimethyl amine (DMA) or DMA-like structures, which are N-nitrosodimethylamine (NDMA) precursors after chlorination or chloramination. Furthermore, it was observed that using dissolved organic nitrogen and DMA to predict NDMAFP could lead to biased conclusions because of the complex nature of nitrogenous matters in aqueous environments.

  16. A process to provide harmonised criteria for the selection of indicators for pesticide risk reduction within the framework of the sustainable use directive.

    PubMed

    Calliera, Maura; Marchis, Alex; Bollmohr, Silke; Sacchettini, Gabriele; Lamastra, Lucrezia; Capri, Ettore

    2013-04-01

    In October 2009, the Council of the European Union adopted the Directive on Sustainable Use of Pesticides (EU 128/2009/EC). This directive establishes a framework to achieve the sustainable use of pesticides by reducing the risk and impacts of pesticide use on both human health and the environment, and promoting the use of integrated pest management and of alternative approaches or techniques. These risks thus need to be assessed using appropriate risk indicators. The OPERA Research Centre organised an expert working group and has had several consultations with stakeholders in order to identify a common way of thinking in evaluating and identifying the factors that should be considered in selecting each indicator. Harmonised criteria have been suggested to allow the selection of the most appropriate indicators, focusing on the use phase of pesticide, as requested by the sustainable use directive. The proposed methodology has led to a sharing of perspectives and knowledge between the experts involved, and some principles have been identified to help national regulatory institutions to estimate general trends in pesticide risk reduction.

  17. Reduction of pertechnetate by acetohydroxamic acid: Formation of [TcNO(AHA)2(H2O)]+ and implications for the UREX process.

    SciTech Connect

    1Harry Reid Center for Environmental Studies, Nuclear Science and Technology Division, University of Nevada, Las Vegas, Las Vegas, NV, 89154-4006; Gong, Cynthia-May S; Poineau, Frederic; Lukens, Wayne W; Czerwinski, Kenneth R.

    2008-02-26

    Reductive nitrosylation and complexation of ammonium pertechnetate by acetohydroxamic acid has been achieved in aqueous nitric and perchloric acid solutions. The kinetics of the reaction depend on the relative concentrations of the reaction components and are accelerated at higher temperatures. The reaction does not occur unless conditions are acidic. Analysis of the x-ray absorption fine structure spectroscopic data is consistent with a pseudo-octahedral geometry with the linear Tc-N-O bond typical of technetium nitrosyl compounds, and electron spin resonance spectroscopy is consistent with a the d{sup 5} Tc(II) nitrosyl complex. The nitrosyl source is generally AHA, but may be augmented by products of reaction with nitric acid. The resulting low-valency trans-aquonitrosyl(diacetohydroxamic)-technetium(II) complex (1) is highly soluble in water, extremely hydrophilic, and is not extracted by tri-n-butylphosphate in a dodecane diluent. Its extraction properties are not pH-dependent; titration studies indicate a single species from pH 4.5 down to -0.6 (calculated). This molecule is resistant to oxidation by H{sub 2}O{sub 2}, even at high pH, and can undergo substitution to form other technetium nitrosyl complexes. The formation of 1 may strongly impact the fate of technetium in the nuclear fuel cycle.

  18. Reduction of Pertechnetate By Acetohydroxamic Acid: Formation of [tc**II(NO)(AHA)(2)(H(2)O)]**+ And Implications for the UREX Process

    SciTech Connect

    Gong, C.-M.S.; Lukens, W.W.; Poineau, F.; Czerwinski, K.R.

    2009-05-18

    Reductive nitrosylation and complexation of ammonium pertechnetate by acetohydroxamic acid has been achieved in aqueous nitric and perchloric acid solutions. The kinetics of the reaction depend on the relative concentrations of the reaction components and are accelerated at higher temperatures. The reaction does not occur unless conditions are acidic. Analysis of the X-ray absorption fine structure spectroscopic data is consistent with a pseudo-octahedral geometry and the linear Tc-N-O bond typical of technetium nitrosyl compounds, and electron spin resonance spectroscopy is consistent with a d{sup 5} Tc(II) nitrosyl complex. The nitrosyl source is generally AHA, but it may be augmented by some products of the reaction with nitric acid. The resulting low-valency trans-aquonitrosyl(diacetohydroxamic)-technetium(II) complex ([Tc{sup II}(NO)(AHA){sub 2}H{sub 2}O]{sup +}, 1) is highly soluble in water, extremely hydrophilic, and is not extracted by tri-n-butylphosphate in a dodecane diluent. Its extraction properties are not pH-dependent: potentiometric-spectrophotometric titration studies indicate a single species from pH 4 down to -0.6 (calculated). This molecule is resistant to oxidation by H{sub 2}O{sub 2}, even at high pH, and can undergo substitution to form other technetium nitrosyl complexes. The potential formation of 1 during reprocessing may strongly impact the fate of technetium in the nuclear fuel cycle.

  19. Production of aluminum-silicon alloy and ferrosilicon and commercial purity aluminum by the direct reduction process. First interim technical report, Phase D, January 1-March 31, 1981

    SciTech Connect

    Bruno, M.J.

    1981-04-01

    Operation of the bench AF-reactor on burden with all reducing carbon exterior to the ore pellet resulted in low metal alloy product yields and prematurely terminated runs, indicating the need for intimate contact between alumina and carbon to produce oxycarbide liquid prior to reaction with solid silicon carbide. Carbon solubility tests made on 60Al-40Si alloys at 2200/sup 0/C in graphite crucibles indicated continued reaction to form SiC for one hour. Efficiency of reduction to SiC ranged from 68 to 100%. The A-C two-electrode submerged arc reactor pilot, SAR-II, was successfully operated on both alumina-clay-coke and alumina-silicon carbide-coke (from the VSR prereduction) burdens. Metal alloy was produced and tapped in each of four runs. The pilot crystallizer was operated to evalute the two-stage (stop and go) crystallization technique on obtaining high yields of Al in Al-Si eutectic, with a limit of 1.0% Fe and 0.1% Ti in the alloy product. 18 figures, 19 tables. (DLC)

  20. A process for containment removal and waste volume reduction to remediate groundwater containing certain radionuclides, toxic metals and organics. Final report

    SciTech Connect

    Buckley, L.P.; Killey, D.R.W.; Vijayan, S.; Wong, P.C.F.

    1992-09-01

    A project to remove groundwater contaminants by an improved treatment process was performed during 1990 October--1992 March by Atomic Energy of Canada Limited for the United States Department of Energy, managed by Argonne National Laboratory. The goal was to generate high-quality effluent while minimizing secondary waste volume. Two effluent target levels, within an order of magnitude, or less than the US Drinking Water Limit, were set to judge the process effectiveness. The program employed mixed waste feeds containing cadmium, uranium, lead, iron, calcium, strontium-85-90, cesium-137, benzene and trichlorethylene in simulated and actual groundwater and soil leachate solutions. A combination of process steps consisting of sequential chemical conditioning, cross-flow microfiltration and dewatering by low temperature-evaporation, or filter pressing were effective for the treatment of mixed waste having diverse physico-chemical properties. A simplified single-stage version of the process was implemented to treat ground and surface waters contaminated with strontium-90 at the Chalk River Laboratories site. Effluent targets and project goals were met successfully.

  1. Digital computer modeling of the process of reduction of redundancy in multichannel telemetry information by the method of adaptive discretization with associative sorting

    NASA Technical Reports Server (NTRS)

    Tolmadzheva, T. A.; Kantor, A. V.; Rozhkovskiy, L. V.

    1974-01-01

    Digital computer modeling of the process of adaptive discretization with associative sorting of actual multichannel telemetry information is discussed. The main task in modeling is production of initial data for determination of dependences describing the operation of the on-board information compression device. Conclusions are presented including the shortcomings of telemetric information used in modeling.

  2. Using a Systematic Conceptual Model for a Process Evaluation of a Middle School Obesity Risk-Reduction Nutrition Curriculum Intervention: Choice, Control & Change

    PubMed Central

    Lee, Heewon; Contento, Isobel R.; Koch, Pamela

    2012-01-01

    Objective To use and review a conceptual model of process evaluation and to examine the implementation of a nutrition education curriculum, Choice, Control & Change, designed to promote dietary and physical activity behaviors that reduce obesity risk. Design A process evaluation study based on a systematic conceptual model. Setting Five middle schools in New York City. Participants 562 students in 20 classes and their science teachers (n=8). Main Outcome Measures Based on the model, teacher professional development, teacher implementation, and student reception were evaluated. Also measured were teacher characteristics, teachers’ curriculum evaluation, and satisfaction with teaching the curriculum. Analysis Descriptive statistics and Spearman’s Rho Correlation for quantitative analysis and content analysis for qualitative data were used. Results Mean score of the teacher professional development evaluation was 4.75 on a 5-point scale. Average teacher implementation rate was 73%, and student reception rate was 69%. Ongoing teacher support was highly valued by teachers. Teachers’ satisfaction with teaching the curriculum was highly correlated with students’ satisfaction (p <.05). Teachers’ perception of amount of student work was negatively correlated with implementation and with student satisfaction (p<.05). Conclusions and implications Use of a systematic conceptual model and comprehensive process measures improves understanding of the implementation process and helps educators to better implement interventions as designed. PMID:23321021

  3. Reduction of Surface Errors over a Wide Range of Spatial Frequencies Using a Combination of Electrolytic In-Process Dressing Grinding and Magnetorheological Finishing

    NASA Astrophysics Data System (ADS)

    Kunimura, Shinsuke; Ohmori, Hitoshi

    We present a rapid process for producing flat and smooth surfaces. In this technical note, a fabrication result of a carbon mirror is shown. Electrolytic in-process dressing (ELID) grinding with a metal bonded abrasive wheel, then a metal-resin bonded abrasive wheel, followed by a conductive rubber bonded abrasive wheel, and finally magnetorheological finishing (MRF) were performed as the first, second, third, and final steps, respectively in this process. Flatness over the whole surface was improved by performing the first and second steps. After the third step, peak to valley (PV) and root mean square (rms) values in an area of 0.72 x 0.54 mm2 on the surface were improved. These values were further improved after the final step, and a PV value of 10 nm and an rms value of 1 nm were obtained. Form errors and small surface irregularities such as surface waviness and micro roughness were efficiently reduced by performing ELID grinding using the above three kinds of abrasive wheels because of the high removal rate of ELID grinding, and residual small irregularities were reduced by short time MRF. This process makes it possible to produce flat and smooth surfaces in several hours.

  4. The reduction of gas phase air toxics from combustion and incineration sources using the GE-MITSUI-BE activated coke process

    SciTech Connect

    Olson, D.G.

    1995-12-31

    The dry desulfurization, denitrification and air toxics removal process using activated coke (AC) was originally researched and developed during the 1960s by Bergbau Forschung (BF), now called Deutsche Montan Technologies. Mitsui Mining Company (MMC) signed a licensing agreement with BF in 1982 to investigate, test and adapt the system to the facilities in Japan. Japanese regulations are stricter than in the U.S. toward SO{sub x}/NO{sub x} pollutants, as well as flyash emissions from the utility industry, oil refineries and other industries. This process is installed on flour coal-fired boilers and Fluidized Catalytic Cracker (FCC) units. These plants were constructed by MCC in Japan and Uhde GmbH in Germany. General Electric Environmental Systems, Inc. (GEESI) signed a license agreement in 1992 with MMC and Mitsui and Company, Ltd. of Tokyo. Under this agreement, GEESI will market, design, fabricate and install the Mitsui-BF press for flue gas cleaning applications in North America. MMC also developed a technology to produce AC used in the dry DeSO{sub x}/DeNO{sub x}/Air Toxics removal process based on their own metallurgical coke manufacturing technology. This paper provides information on the details of MMC`s AC used in the dry DeSO{sub x}/DeNO{sub x}/Air Toxics removal process.

  5. Human Factor Investigation of Waste Processing System During the HI-SEAS 4 Month Mars Analog Mission in Support of NASA's Logistic Reduction and Repurposing Project: Trash to Gas

    NASA Technical Reports Server (NTRS)

    Caraccio, Anne; Hintze, Paul; Miles, John D.

    2014-01-01

    NASAs Logistics Reduction and Repurposing (LRR) project is a collaborative effort in which NASA is tasked with reducing total logistical mass through reduction, reuse and recycling of various wastes and components of long duration space missions and habitats. Trash to Gas (TtG) is a sub task to LRR with efforts focused on development of a technology that converts wastes generated during long duration space missions into high-value products such as methane, water for life support, raw material production feedstocks, and other energy sources. The reuse of discarded materials is a critical component to reducing overall mission mass. The 120 day Hawaii Space Exploration and Analog Simulation provides a unique opportunity to answer questions regarding crew interface and system analysis for designing and developing future flight-like versions of a TtG system. This paper will discuss the human factors that would affect the design of a TtG or other waste processing systems. An overview of the habitat, utility usage, and waste storage and generation is given. Crew time spent preparing trash for TtG processing was recorded. Gas concentrations were measured near the waste storage locations and at other locations in the habitat. In parallel with the analog mission, experimental processing of waste materials in a TtG reactor was performed in order to evaluate performance with realistic waste materials.

  6. Human Factor Investigation of Waste Processing System During the HI-SEAS 4-month Mars Analog Mission in Support of NASA's Logistic Reduction and Repurposing Project: Trash to Gas

    NASA Technical Reports Server (NTRS)

    Caraccio, Anne; Hintze, Paul E.; Miles, John D.

    2014-01-01

    NASA's Logistics Reduction and Repurposing (LRR) project is a collaborative effort in which NASA is tasked with reducing total logistical mass through reduction, reuse and recycling of various wastes and components of long duration space missions and habitats. Trash to Gas (TtG) is a sub task to LRR with efforts focused on development of a technology that converts wastes generated during long duration space missions into high-value products such as methane, water for life support, raw material production feedstocks, and other energy sources. The reuse of discarded materials is a critical component to reducing overall mission mass. The 120 day Hawaii Space Exploration and Analog Simulation provides a unique opportunity to answer questions regarding crew interface and system analysis for designing and developing future flight-like versions of a TtG system. This paper will discuss the human factors that would affect the design of a TtG or other waste processing systems. An overview of the habitat, utility usage, and waste storage and generation is given. Crew time spent preparing trash for TtG processing was recorded. Gas concentrations were measured near the waste storage locations and at other locations in the habitat. In parallel with the analog mission, experimental processing of waste materials in a TtG reactor was performed in order to evaluate performance with realistic waste materials.

  7. The efficacy of short and repeated high-pressure processing treatments on the reduction of non-O157:H7 Shiga-toxin producing Escherichia coli in ground beef patties.

    PubMed

    Jiang, Yun; Scheinberg, Joshua A; Senevirathne, Reshani; Cutter, Catherine N

    2015-04-01

    High pressure processing (HPP) has previously been shown to be effective at reducing Escherichia coli O157:H7 in meat products. However, few studies have determined whether HPP may be effective at reducing non-O157:H7 Shiga toxin-producing E. coli (STEC) in ground beef. This study investigated the efficacy of short and repeated HPP treatments to reduce non-O157:H7 STEC inoculated into ground beef. Irradiated ground beef patties (80:20, 90:10 [lean:fat]) were inoculated with pairs of E. coli serogroups O103, O111, O26, O145, O121, O45, O157:H7, and DH5α, vacuum-packaged and high-pressure processed (four, 60 s cycles, 400 MPa, 17°C). Surviving E. coli populations were enumerated on Rainbow Agar O157 and Tryptic Soy Agar. HPP treatments produced >2.0 log₁₀ CFU/g reductions of each E. coli serogroup, and reductions ranged from 2.35-3.88 and 2.26-4.31 log₁₀ CFU/g in 80:20 and 90:10 samples, respectively. These results suggest that HPP could be an effective, post-processing intervention to reduce the risk of non-O157:H7 STEC contamination in ground beef.

  8. Microbial reduction of SO{sub 2} and NO{sub x} as a means of by- product recovery/disposal from regenerable processes for the desulfurization of flue gas. Technical progress report, June 11, 1992--September 11, 1992

    SciTech Connect

    Sublette, K.L.

    1992-12-31

    Based on the work described simultaneous SO{sub 2}/No{sub x} removal from flue gas based on direct contact of the gas with SRB and T. denitrificans co-cultures or cultures-in-series has been eliminated as a viable process concept at this time. The technical reasons are as follows: (1) NO inhibition of SO{sub 2} reduction by D. desulfuricans - Although the NO concentrations used in the experiments described above are somewhat higher than that found in a typical flue gas, it is quite possible that at lower NO concentrations (or partial pressures) the inhibiting effects will simply take longer to become apparent. (2) Nitrate suppression of NO removal - As noted previously, the cultivation of T. denitrificans in a microbial flue gas treatment system (either one or two stages) would require sulfide-limiting conditions. Therefore, the electron acceptor must be in excess, requiring nitrate in the T. denitrificans process culture. As shown in experiments described above, nitrate significantly suppresses the removal of NO from a feed gas making simultaneous SO{sub 2}/NO{sub x} removal impractical by microbial means. (3) O{sub 2} inhibition of SO{sub 2} and NO reduction - It has been demonstrated that D. desulfuricans working cultures are tolerant of up to 1.7% O{sub 2} in the feed gas. However, further increases in the O{sub 2} partial pressure in the feed gas resulted in O{sub 2} inhibition of SO{sub 2} reduction. These inhibiting levels of O{sub 2} are comparable to those concentrations found in flue gases (3). Therefore, in any process in which raw flue gas contacts a D. desulfuricans culture marginal stability at best can be expected.

  9. Microbial reduction of SO[sub 2] and NO[sub x] as a means of by- product recovery/disposal from regenerable processes for the desulfurization of flue gas

    SciTech Connect

    Sublette, K.L.

    1992-01-01

    Based on the work described simultaneous SO[sub 2]/No[sub x] removal from flue gas based on direct contact of the gas with SRB and T. denitrificans co-cultures or cultures-in-series has been eliminated as a viable process concept at this time. The technical reasons are as follows: (1) NO inhibition of SO[sub 2] reduction by D. desulfuricans - Although the NO concentrations used in the experiments described above are somewhat higher than that found in a typical flue gas, it is quite possible that at lower NO concentrations (or partial pressures) the inhibiting effects will simply take longer to become apparent. (2) Nitrate suppression of NO removal - As noted previously, the cultivation of T. denitrificans in a microbial flue gas treatment system (either one or two stages) would require sulfide-limiting conditions. Therefore, the electron acceptor must be in excess, requiring nitrate in the T. denitrificans process culture. As shown in experiments described above, nitrate significantly suppresses the removal of NO from a feed gas making simultaneous SO[sub 2]/NO[sub x] removal impractical by microbial means. (3) O[sub 2] inhibition of SO[sub 2] and NO reduction - It has been demonstrated that D. desulfuricans working cultures are tolerant of up to 1.7% O[sub 2] in the feed gas. However, further increases in the O[sub 2] partial pressure in the feed gas resulted in O[sub 2] inhibition of SO[sub 2] reduction. These inhibiting levels of O[sub 2] are comparable to those concentrations found in flue gases (3). Therefore, in any process in which raw flue gas contacts a D. desulfuricans culture marginal stability at best can be expected.

  10. Anxiety Sensitivity and Pre-Cessation Smoking Processes: Testing the Independent and Combined Mediating Effects of Negative Affect–Reduction Expectancies and Motives

    PubMed Central

    Farris, Samantha G.; Leventhal, Adam M.; Schmidt, Norman B.; Zvolensky, Michael J.

    2015-01-01

    Objective: Anxiety sensitivity appears to be relevant in understanding the nature of emotional symptoms and disorders associated with smoking. Negative-reinforcement smoking expectancies and motives are implicated as core regulatory processes that may explain, in part, the anxiety sensitivity–smoking interrelations; however, these pathways have received little empirical attention. Method: Participants (N = 471) were adult treatment-seeking daily smokers assessed for a smoking-cessation trial who provided baseline data; 157 participants provided within-treatment (pre-cessation) data. Anxiety sensitivity was examined as a cross-sectional predictor of several baseline smoking processes (nicotine dependence, perceived barriers to cessation, severity of prior withdrawal-related quit problems) and pre-cessation processes including nicotine withdrawal and smoking urges (assessed during 3 weeks before the quit day). Baseline negative-reinforcement smoking expectancies and motives were tested as simultaneous mediators via parallel multiple mediator models. Results: Higher levels of anxiety sensitivity were related to higher levels of nicotine dependence, greater perceived barriers to smoking cessation, more severe withdrawal-related problems during prior quit attempts, and greater average withdrawal before the quit day; effects were indirectly explained by the combination of both mediators. Higher levels of anxiety sensitivity were not directly related to pre-cessation smoking urges but were indirectly related through the independent and combined effects of the mediators. Conclusions: These empirical findings bolster theoretical models of anxiety sensitivity and smoking and identify targets for nicotine dependence etiology research and cessation interventions. PMID:25785807

  11. Novel route for rapid sol-gel synthesis of hydroxyapatite, avoiding ageing and using fast drying with a 50-fold to 200-fold reduction in process time.

    PubMed

    Ben-Arfa, Basam A E; Salvado, Isabel M Miranda; Ferreira, José M F; Pullar, Robert C

    2017-01-01

    We have developed an innovative, rapid sol-gel method of producing hydroxyapatite nanopowders that avoids the conventional lengthy ageing and drying processes (over a week), being 200 times quicker in comparison to conventional aqueous sol-gel preparation, and 50 times quicker than ethanol based sol-gel synthesis. Two different sets of experimental conditions, in terms of pH value (5.5 and 7.5), synthesis temperature (45 and 90°C), drying temperature (60 and 80°C) and calcination temperature (400 and 700°C) were explored. The products were characterised by X-ray diffraction (XRD) Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and specific surface area (SSA) measurements. Pure hydroxyapatite (Ca10(PO4)6(OH)2, HAp) was obtained for the powders synthesised at pH7.5 and calcined at 400°C, while biphasic mixtures of HAp/β-tricalcium phosphate (β-Ca3(PO4)2, TCP) were produced at pH5.5 and (pH7.5 at elevated temperature). The novel rapid drying was up to 200 times faster than conventional drying, only needing 1h with no prior ageing step, and favoured the formation of smaller/finer nanopowders, while producing pure HAp or phase mixtures virtually identical to those obtained from the slow conventional drying method, despite the absence of a slow ageing process. The products of this novel rapid process were actually shown to have smaller crystallite sizes and larger SSA, which should result in increased bioactivity.

  12. Minority-carrier lifetime enhancement in edge-defined film-fed grown Si through rapid thermal processing-assisted reduction of hydrogen-defect dissociation

    NASA Astrophysics Data System (ADS)

    Nakayashiki, Kenta; Rohatgi, Ajeet; Ostapenko, Sergei; Tarasov, Igor

    2005-01-01

    This paper demonstrates that a very short, 1-s, simultaneous firing of screen-printed Al at the back and SiNx antireflection (AR) coating at the front can significantly enhance the minority-carrier lifetime in edge-defined film-fed grown (EFG) ribbon Si via SiNx-induced hydrogen passivation of defects. It was found that 1-s firing in a rapid thermal processing system at an optimum temperature improved the average minority-carrier lifetime from 3to>80μs, resulting in ˜16% efficient 4-cm2 screen-printed EFG Si cells. It is proposed that rapid thermal firing enhances the retention of hydrogen at defect sites by minimizing the hydrogen-defect dissociation. A combination of simulations and experiments reveals that the dissociation of hydrogen is extremely rapid at conventional firing temperatures of ˜700°C. An activation energy of 2.4-2.6eV was determined for the hydrogen-defect dissociation in EFG Si. This activation energy, in conjunction with the room-temperature photoluminescence data, suggests that the impurity-decorated dislocations are the dominant hydrogenation and dehydrogenation sites in the EFG Si. Based on the above understanding, a manufacturable process, involving rapid co-firing of SiNx AR coating, screen-printed Al-doped back surface field (Al-BSF), and screen-printed Ag front grid, was developed in a conventional belt furnace to minimize the degree of dehydrogenation while producing good Al-BSF and ohmic contacts. This process produced 4-cm2 screen-printed EFG Si cells with an efficiency of 15.9%.

  13. Use of a fluidized bed hammer mill for size reduction and classification: effects of process variables and starting materials on the particle size distribution of milled lactose batches.

    PubMed

    Lee, C C; Chan, L W; Heng, Paul W S

    2003-01-01

    The process capability of a fluidized bed hammer mill was investigated with respect to four process variables, namely, rotational speeds of beater system and classifier wheel, airflow rates and length of grinding zones, as well as the particle size and flow property of the starting materials. The size distributions of all the milled lactose batches could be fitted to the Rosin Rammler distribution (RRD) function. The characteristic particle size (De) and uniform coefficient (n), which were derived from the RRD function, complemented the size at the 99th percentile of the cumulative undersize distribution (D99) to characterize the lactose batches. Lower De and D99 values indicate a finer powder while a higher n value indicates a narrower size distribution. The beater speed played a critical role. Increasing the beater speed from 12000 to 21000 rpm generally resulted in an increase in n and a decrease in D99 values due to the greater amount of milling energy supplied. The particle size and flow property of the starting material also played an important role at beater speed of 12000 rpm, where the lowest amount of milling energy was supplied. When a higher amount of milling energy was provided, the effect of particle size of the starting material was less significant. The other process variables exerted varying effects. Increasing the classifier wheel speed from 5000 to 15000 rpm decreased the De and D99 and increased the n values of the milled lactose batches, provided sufficient milling energy was supplied to the lactose particles. Changing airflow rates from 80 to 90 m3/h generally resulted in larger De and D99 values and lower n values as the higher airflow rate provided greater airflow-induced kinetic energy that facilitated the passage of lactose through the classifier wheel. However, changing the long grinding zone to a short one did not significantly affect the De, D99 and n values of the milled lactose batches produced. Small lactose particles of narrow size

  14. Performing a local reduction operation on a parallel computer

    SciTech Connect

    Blocksome, Michael A.; Faraj, Daniel A.

    2012-12-11

    A parallel computer including compute nodes, each including two reduction processing cores, a network write processing core, and a network read processing core, each processing core assigned an input buffer. Copying, in interleaved chunks by the reduction processing cores, contents of the reduction processing cores' input buffers to an interleaved buffer in shared memory; copying, by one of the reduction processing cores, contents of the network write processing core's input buffer to shared memory; copying, by another of the reduction processing cores, contents of the network read processing core's input buffer to shared memory; and locally reducing in parallel by the reduction processing cores: the contents of the reduction processing core's input buffer; every other interleaved chunk of the interleaved buffer; the copied contents of the network write processing core's input buffer; and the copied contents of the network read processing core's input buffer.

  15. Performing a local reduction operation on a parallel computer

    DOEpatents

    Blocksome, Michael A; Faraj, Daniel A

    2013-06-04

    A parallel computer including compute nodes, each including two reduction processing cores, a network write processing core, and a network read processing core, each processing core assigned an input buffer. Copying, in interleaved chunks by the reduction processing cores, contents of the reduction processing cores' input buffers to an interleaved buffer in shared memory; copying, by one of the reduction processing cores, contents of the network write processing core's input buffer to shared memory; copying, by another of the reduction processing cores, contents of the network read processing core's input buffer to shared memory; and locally reducing in parallel by the reduction processing cores: the contents of the reduction processing core's input buffer; every other interleaved chunk of the interleaved buffer; the copied contents of the network write processing core's input buffer; and the copied contents of the network read processing core's input buffer.

  16. Thermal analysis and 454 pyrosequencing to evaluate the performance and mechanisms for deep stabilization and reduction of high-solid anaerobically digested sludge using biodrying process.

    PubMed

    Li, Xiaowei; Dai, Xiaohu; Yuan, Shijie; Li, Ning; Liu, Zhigang; Jin, Jingwei

    2015-01-01

    Biodrying was firstly used for post-treatment of anaerobically digested sludge (ADS) with wheat residues (WR) as bulking agents to improve its quality and reduce its amount. After 18days of biodrying, water was removed at a rate of 664.4gkg(-1) initial water at the typical ratio of ADS/WR. A separate aerobic incubation test showed that 8.11-14.84% of volatile solid (VS) was degraded in the ADS. The degradation of C- and H-containing materials (e.g., carboxylic acid) accounted for oxygen consumption and VS loss. The WR also showed strong biodegradability, and contributed approximately 86.01% of biogenerated heat during the process. Thermal balance analysis showed that the produced heat was primarily consumed through water evaporation and conductive transfer. 454 pyrosequencing implied the obvious succession from the anaerobic to aerobic microorganisms during the process. Some dominant Firmicutes, such as Clostridium and Bacillales, seemed to relate with organic matter degradation of the substrates.

  17. Improved critical current density in ex situ processed MgB2 tapes by the size reduction of grains and crystallites by high-energy ball milling

    NASA Astrophysics Data System (ADS)

    Fujii, Hiroki; Ishitoya, Akira; Itoh, Shinji; Ozawa, Kiyoshi; Kitaguchi, Hitoshi

    2017-03-01

    We have fabricated Fe-sheathed MgB2 tapes through an ex situ process in a powder-in-tube (PIT) technique using powders ball milled under various conditions. Although the ex situ processed wires and tapes using the high-energy ball milled MgB2 powders have been studied and the decrease of grain and crystallite sizes of MgB2 and the critical current density (Jc) improvement of those conductors were reported so far, the use of filling powders milled at a higher rotation speed than previously reported further decreases the crystallite size and improves the Jc properties. The improved Jc values at 4.2 K and 10 T were nearly twice as large as those previously reported. Those milled powders and hence as-rolled tapes easily receive contamination in air. Thus, the transport Jc properties are easily deteriorated and scattered unless the samples are handled with care. The optimized heat treatment temperature (Topt) of those tape samples at which best performance in the Jc property is obtained decreases by more than 100 °C, compared with that of tapes using the as-received MgB2 powder.

  18. Recovery of residual soluble protein by two-step precipitation process with concomitant COD reduction from the yeast-cultivated cheese whey.

    PubMed

    Yadav, J S S; Yan, S; More, T T; Tyagi, R D; Surampalli, R Y

    2014-09-01

    The present study was conducted to recover the residual soluble protein after cultivation of yeast (K. marxianus) in cheese whey. Cheese whey continuous fermentation with cell recycle system was carried out at 40 °C and pH 3.5. The yeast biomass was separated from the fermented broth by centrifugation and residual soluble protein from fermented whey supernatant was precipitated by heat treatment (at 100 °C, pH 4.5 and 10 min incubation). The maximum soluble protein recovery up to 53 % was achieved at pH 4.5 with 54 % residual COD removal. However, gravity sedimentable precipitates were obtained at pH 3.5 with 47 % protein recovery. Therefore, the reactor (scale up) study was conducted at pH 3.5 with agitation, which resulted in 68 % of residual soluble protein recovery and simultaneously residual COD removal of 62 %. Further precipitation/coagulation of soluble protein was also evaluated using carboxymethylcellulose (CMC) and then two precipitation (thermal followed by CMC precipitation) processes were combined to increase the protein precipitation, which finally reached up to 81 % of total soluble protein recovery from the supernatant. This optimized process could be applied to recover the residual protein left after fermentation of cheese whey without centrifugation.

  19. 50 CFR 600.1012 - Reduction loan.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., DEPARTMENT OF COMMERCE MAGNUSON-STEVENS ACT PROVISIONS Fishing Capacity Reduction Framework § 600.1012... not exceed the maximum principal amount in the fishing capacity reduction specifications; (2) At an... projected, for the purpose of any aspect of reduction planning or processing under this subpart, before...

  20. Uranium Reduction by Clostridia

    SciTech Connect

    Francis, A.J.; Dodge, Cleveland J.; Gillow, Jeffrey B.

    2006-04-05

    The FRC groundwater and sediment contain significant concentrations of U and Tc and are dominated by low pH, and high nitrate and Al concentrations where dissimilatory metal reducing bacterial activity may be limited. The presence of Clostridia in Area 3 at the FRC site has been confirmed and their ability to reduce uranium under site conditions will be determined. Although the phenomenon of uranium reduction by Clostridia has been firmly established, the molecular mechanisms underlying such a reaction are not very clear. The authors are exploring the hypothesis that U(VI) reduction occurs through hydrogenases and other enzymes (Matin and Francis). Fundamental knowledge of metal reduction using Clostridia will allow us to exploit naturally occurring processes to attenuate radionuclide and metal contaminants in situ in the subsurface. The outline for this report are as follows: (1) Growth of Clostridium sp. under normal culture conditions; (2) Fate of metals and radionuclides in the presence of Clostridia; (3) Bioreduction of uranium associated with nitrate, citrate, and lepidocrocite; and (4) Utilization of Clostridium sp. for immobilization of uranium at the FRC Area 3 site.

  1. Effect of process parameters on succinic acid production in Escherichia coli W3110 and enzymes involved in the reductive tricarboxylic acid cycle.

    PubMed

    Isar, Jasmine; Agarwal, Lata; Saran, Saurabh; Gupta, Pritesh; Saxena, Rajendra Kumar

    2006-09-01

    The effect of process optimization on succinic acid production by Escherichia coli W3110 and on enzymes involved in the reverse tricarboxylic acid cycle was studied. Approximately, 7.02 g L-1 of succinic acid was produced in 60 h at pH 7.0 in 500 mL anaerobic bottles containing 300 mL of the medium, wherein the sucrose concentration was 2.5%, the ratio of tryptone to ammonium hydrogen phosphate was 1:1, and the concentration of magnesium carbon ate was 1.5%. When these optimized fermentation conditions were employed in a 10 L bioreactor, 11.2 g L-1 of succinic acid was produced in 48 h. This is a 10-fold increase in succinic acid production from the initial titer of 0.94 g L-1. This clearly indicates the importance of process optimization, where by manipulating the media composition and production conditions, a remarkable increase in the production of the desired biomolecule can be obtained. The production of succinic acid is a multi-step reaction through the reverse tricarboxylic acid cycle. A linear relationship was observed between succinic acid production and the enzyme activities. The enzyme activities were found to increase in the order phospho-enol-pyruvate carboxylase

  2. Breast Reduction Surgery

    MedlinePlus

    ... considering breast reduction surgery, consult a board-certified plastic surgeon. It's important to understand what breast reduction ... risk of complications from breast reduction surgery. Your plastic surgeon will likely: Evaluate your medical history and ...

  3. Quantitative comparison of post-processing methods for reduction of frequency modulation sidebands in non-water suppression 1H MRS.

    PubMed

    Lin, Jyh-Miin; Chuang, Tzu-Chao; Chung, Hsiao-Wen; Tsai, Shang-Yueh

    2013-04-01

    Non-water suppression MRS (NWS MRS) has several advantages. First, the unsuppressed water signal can be used as internal calibration for metabolite quantification and as a reliable frequency/phase reference for retrospective motion correction. Second, it avoids the potential artifacts caused by incomplete water suppression (WS) and extra radiofrequency deposition from WS pulses. However, the frequency modulation (FM) sidebands originating from a large water signal will distort the spectrum. Among the methods proposed to solve the problems caused by FM sidebands, post-acquisition processing methods are superior in flexibility for general use compared with experimental methods. In this study, we propose two algorithms based on advanced matrix decomposition to remove the FM sidebands. These methods, the simultaneous diagonalization (QZ) algorithm and its subsequent variant, the simultaneously generalized Schur decomposition (SGSD) algorithm, were numerically evaluated using computer simulations. In addition, we quantitatively compared the performance of these methods and the modulus method in an in vitro experiment and in vivo NWS MRS against conventional WS data. Our results show that the proposed SGSD algorithm can reduce the FM sidebands to achieve superior estimation of concentration on three major metabolites. This method can be applied directly to spectra pre-acquired under various experimental conditions without modifying the acquisition sequences.

  4. Separation behavior of impurities and selenium reduction by the reactive zone refining process using high-frequency induction heating to purify Te

    NASA Astrophysics Data System (ADS)

    Shim, Moonsoo; Kim, Young-Min; Lee, Huk-Hee; Hong, Soon-Jik; Lee, Jong-Hyeon

    2016-12-01

    A zone refining processing was utilized to purify tellurium (Te) metal using a locally melted zone caused by high-frequency induction heating. The travel rate of the molten zone was set as a parameter. The purification efficiency for each impurity (Bi, Sb, Sn, and Se) in the tellurium sample was analyzed by inductively coupled plasma optical emission spectroscopy (ICP-OES), and the experimental results were compared with the theoretical results furnished by the proposed model to validate its predictions. The experimental results indicated that a lower travel rate of the molten zone and repetition of passes were more efficient for purification. The effective distribution coefficient keff and the keff values of bismuth, antimony, tin, and selenium were 0.5, 0.35, 0.22, and 0.58, respectively. These elements were effective for the purification of Te by zone refining. The obtained distribution coefficient keff values of impurities can be used as standards for the purification of Te by zone refining. The Vickers hardness was measured, and a correlation between hardness and concentration was observed, with an average Vickers hardness was 62 Hv.

  5. Role of carbon substrates in facilitating energy reduction and resource recovery in a traditional activated sludge process: investigation from a biokinetics modeling perspective.

    PubMed

    Wang, Xu; Liu, Junxin; Qu, Bo; Ren, Nan-Qi; Qu, Jiuhui

    2013-07-01

    Three activated sludge processes (ASPs) were modeled and driven by dissolved complex organics (F-ASP), propionic acid (P-ASP), and acetic acid (A-ASP), and various parameters were subsequently estimated. The energy depletion for carbon removal was 0.146, 0.120, and 0.119 kWh/m(3) of treated wastewater for F-ASP, P-ASP, and A-ASP, respectively, suggesting that acetic acid can forward energy conservation. The ratio of substrate storage to oxidation in F-ASP, P-ASP, and A-ASP was 0, 0.25, and 0.52, respectively, further demonstrating that substrate eliminations from P-ASP and A-ASP were both dominated by substrate storage for polymer production, not by total oxidation; thus, they exhibited lower energy-consuming levels than F-ASP. Quantification of bioenergy production and nutrient acquisition from the excess sludge of the three ASPs were conducted subsequently, and A-ASP was found to facilitate phosphorus capture.

  6. Lymphedema Risk Reduction Practices

    MedlinePlus

    ... now! Position Paper: Lymphedema Risk Reduction Practices Category: Position Papers Tags: Risks Archives Treatment risk reduction garments surgery obesity infection blood pressure trauma morbid obesity body weight ...

  7. Study on Toxicity Reduction and Potency Induction in Whole-cell Pertussis Vaccine by Developing a New Optimal Inactivation Condition Processed on Bordetella pertussis

    PubMed Central

    Mohammadpour Dounighi, Naser; Razzaghi-Abyane, Mehdi; Nofeli, Mojtaba; Zolfagharian, Hossein; Shahcheraghi, Fereshteh

    2016-01-01

    Background Whooping cough is caused by Bordetella pertussis, and it remains a public health concern. Whole-cell pertussis vaccines have been commonly employed for expanded immunization. There is no doubt of the efficacy of whole cell pertussis vaccine, but it is necessary to improve the vaccine to decrease its toxicity. Objectives In this study, an inactivation process of dealing with pertussis bacteria is optimized in order to decrease the bacteria content in human doses of vaccines and reduce the vaccine’s toxicity. Materials and Methods The bacterial suspensions of pertussis strains 509 and 134 were divided into 21 sample parts from F1 to F21 and inactivated under different conditions. The inactivated suspensions of both strains were tested for opacity, non-viability, agglutination, purity, and sterility; the same formulation samples that passed quality tests were then pooled together. The pool of inactivated suspensions were analyzed for sterility, agglutination, opacity, specific toxicity, and potency. Results The harvest of both bacterial strains showed purity. The opacity of various samples were lost under different treatment conditions by heat from 8% to 12%, formaldehyde 6% to 8%, glutaraldehyde 6% to 8%, and thimerosal 5% to 8%. Tests on suspensions after inactivation and on pooled suspensions showed inactivation conditions not degraded agglutinins of both strains. The samples of F2, F4, F8, F12, F15, and F17 passed the toxicity test. The potency (ED50) of these samples showed following order F17 > F12 > F8 > F15, F4 > F2, and F17 revealed higher potency compared to other formulations. Conclusions It can be concluded that F17 showed desirable outcomes in the toxicity test and good immunogenicity with a low bacterial number content. Consequently, lower adverse effects and good immunogenicity are foreseeable for vaccine preparation with this method. PMID:27679704

  8. Tritium Emissions Reduction Facility

    SciTech Connect

    Wieneke, R.E.; Bowser, R.P.; Hedley, W.H.; Kissner, T.J.; Lamberger, P.H.; Morgan, F.G.; Van Patten, J.F.; Williams, M.A.

    1988-01-01

    The Tritium Emissions Reduction Facility (TERF) will be a system for the continuous processing of tritium containing gases collected from various operations at Mound. The basis of the system operation will be the oxidation of elemental hydrogen isotopes and organic molecules at elevated temperatures on precious metal catalyst beds, and the adsorption of the resulting oxide (water) on molecular sieve dryers. The TERF will be expected to handle from 400,000 to 1,000,000 curies of tritium per year in the process gas stream and release no more than 200 curies per year to the atmosphere. Consequently, the TERF will need to convert and capture tritium at low concentrations in gas efficiently and reliably. 5 refs., 2 figs.

  9. The effects of Fe-oxidizing microorganisms on post-biostimulation permeability reduction and oxidative processes at the Rifle IFRC site

    SciTech Connect

    Chan, Clara Sze-Yue

    2015-07-02

    through the aquifer. Our work shows that microbial mineralization impacts in aquifers are dynamic, and that the fate and transport of biomineral-associated elements depend not only on geochemical conditions, but also physical pore-scale processes.

  10. The Reductive Dehydration of Cellulose by Solid/Gas Reaction with TiCl4 at Low Temperature: A Cheap, Simple, and Green Process for Preparing Anatase Nanoplates and TiO2 /C Composites.

    PubMed

    Plumejeau, Sandrine; Rivallin, Matthieu; Brosillon, Stephan; Ayral, André; Heux, Laurent; Boury, Bruno

    2016-11-21

    Metal oxides and metal oxide/carbon composites are entering the development of new technologies and should therefore to be prepared by sustainable chemistry processes. Therefore, a new aspect of the reactivity of cellulose is presented through its solid/gas reaction with vapour of titanium(IV) chloride in anhydrous conditions at low temperature (80 °C). This reaction leads to two transformations both for cellulose and titanium(IV) chloride. A reductive dehydration of cellulose is seen at the lowest temperature ever reported and results in the formation of a carbonaceous fibrous solid as the only carbon-containing product. Simultaneously, the in situ generation of water leads to the formation of titanium dioxide with an unexpected nanoplate morphology (ca. 50 nm thickness) and a high photocatalytic activity. We present the evidence showing the evolution of the cellulose and the TiO2 nanostructure formation, along with its photocatalytic activity. This low-temperature process avoids any other reagents and is among the greenest processes for the preparation of anatase and also for TiO2 /carbon composites. The anisotropic morphology of TiO2 questions the role of the cellulose on the growing process of these nanoparticles.

  11. Production of aluminum-silicon alloy and ferrosilicon and commercial purity aluminum by the direct reduction process. First interim technical report, Phase C for the period 1980 January 1-1980 March 31

    SciTech Connect

    Bruno, M.J.

    1980-10-01

    Pilot reactor VSR-3 was operated with 75 to 120 SCFH O/sub 2/ to supply part of the process heat requirements by combustion of coke. No alloy was made and burden bridging persistently stopped operations. Burning larger coke particles, -3/8 in. +6 mesh, with O/sub 2/ injected through a larger diameter tuyere orifice resulted in oxygen attack on the reactor graphite liner. Updated thermochemical data for Al/sub 2/O/sub 3/ significantly changed the calculated reflux loading for a one-atm blast furnace, predicting almost total reflux and no alloy recovery. Based on these calculations and the experimental problems with combustion heated operation, VSR-3 was modified to study an alternate reduction concept - the blast-arc - which utilizes combustion heat to reduce SiO/sub 2/ to SiC at 1600/sup 0/C, and electrical heat to complete the reduction of Al/sub 2/O/sub 3/ and the production of alloy. Design, fabrication, and installation of most of the pilot crystallizer sytem was completed.

  12. Microbial reduction of SO{sub 2} and NO{sub x} as a means of by-product recovery/disposal from regenerable processes for the desulfurization of flue gas. Final report

    SciTech Connect

    Sublette, K.L.

    1994-03-01

    The main objective of this research was to investigate microorganisms capable of fossil fuel flue gas desulfurization and denitrification. The study used municipal sewage sludge as a carbon and energy source for SO{sub 2}-reducing cultures. The individual tasks developed a consortium of sulfate-reducing bacteria, investigated the design parameters for a continuous process, preformed a cost analysis, and screened sulfate-reducing bacteria. In the investigation of microbial reduction of NO{sub x} to nitrogen, tasks included screening denitrifying bacteria for NO and NO{sub 2} activity, developing optimum NO-reducing cultures, and investigating design parameters for a continuous system. This final report reviews the work previous to the current project, describes project objectives and the specific work plan, and reports results from the work completed during the previous reporting periods.

  13. Influence of the hot-fill water-spray-cooling process after continuous pasteurization on the number of decimal reductions and on Alicyclobacillus acidoterrestris CRA 7152 growth in orange juice stored at 35 degrees C.

    PubMed

    Spinelli, Ana Cláudia N F; Sant'Ana, Anderson S; Pacheco-Sanchez, Cristiana P; Massaguer, Pilar R

    2010-02-28

    In this study, the influence of the hot-fill water-spray-cooling process after continuous pasteurization on the number of decimal reductions (gamma) and growth parameters (lag time; lambda, ratio N(f)/N(o); kappa, maximum growth rate; mu) of Alicyclobacillus acidoterrestris CRA 7152 in orange juice stored at 35 degrees C were investigated. Two different inoculum levels of A. acidoterrestris CRA 7152 (10(2) and 10(3) spores/mL) in orange juice (11(0)Brix, pH 3.7) and a Microthermics UHT-HTST pilot plant were used to simulate industrial conditions. Results have shown that regardless of the inoculum level (10(2) or 10(3) spores/mL), the pasteurization processes were unable to cause even 1 gamma. Predictive modeling using the Baranyi model showed that only kappa and time to reach 10(4)spores/mL (t10(4) - time to juice spoilage) were affected by the spore inoculum used (p<0.05). It has been concluded that A. acidoterrestris was able to survive the hot-fill process and to grow and spoil orange juice in 5-6 days when the final storage temperature was 35 degrees C.

  14. Thermodynamics of lunar ilmenite reduction

    NASA Technical Reports Server (NTRS)

    Altenberg, B. H.; Franklin, H. A.; Jones, C. H.

    1993-01-01

    With the prospect of returning to the moon, the development of a lunar occupation would fulfill one of the goals of the Space Exploration Initiative (SEI) of the late 1980's. Processing lunar resources into useful products, such as liquid oxygen for fuel and life support, would be one of many aspects of an active lunar base. ilmenite (FeTiO3) is found on the lunar surface and can be used as a feed stock to produce oxygen. Understanding the various ilmenite-reduction reactions elucidates many processing options. Defining the thermodynamic chemical behavior at equilibrium under various conditions of temperature and pressures can be helpful in specifying optimal operating conditions. Differences between a previous theoretical analysis and experimentally determined results has sparked interest in trying to understand the effect of operating pressure on the hydrogen-reduction-of-ilmenite reaction. Various aspects of this reduction reaction are discussed.

  15. Induction slag reduction process for purifying metals

    DOEpatents

    Traut, Davis E.; Fisher, II, George T.; Hansen, Dennis A.

    1991-01-01

    A continuous method is provided for purifying and recovering transition metals such as neodymium and zirconium that become reactive at temperatures above about 500.degree. C. that comprises the steps of contacting the metal ore with an appropriate fluorinating agent such as an alkaline earth metal fluosilicate to form a fluometallic compound, and reducing the fluometallic compound with a suitable alkaline earth or alkali metal compound under molten conditions, such as provided in an induction slag metal furnace. The method of the invention is advantageous in that it is simpler and less expensive than methods used previously to recover pure metals, and it may be employed with a wide range of transition metals that were reactive with enclosures used in the prior art methods and were hard to obtain in uncontaminated form.

  16. Industrial waste reduction: The process problem

    SciTech Connect

    Valentino, F.W.; Walmet, G.E.

    1986-09-01

    Industrial waste problems, especially those involving hazardous waste, seem to be pervasive. The national media report newly discovered waste problems and sites with alarming regularity. Examples that immediately come to mind are Love Canal, New York; Times Beach, Missouri; and Seveso, Italy. Public perceptions of the industrial waste problem, reflecting the media's focus, appear to be that: large corporations are solely responsible for creating waste dumps, and the only role of government is to prevent illegal dumping and to regulate, fine, and require corporations to rectify the problem; all efforts should be directed toward preventing illegal dumping and treatment of the existing waste dumps; all industrial wastes can be classified as hazardous in nature. This general impression is both inaccurate and incomplete. All industrial waste is not hazardous (although most of it is not benign). All waste producers are not large corporations: nearly all industries produce some wastes. And, while existing waste sites must be effectively treated, additional efforts are needed at other points in the industrial waste cycle. Most people would agree both that waste dumping must be carefully regulated because of its negative impacts on the environment and that the less waste the better, even with carefully regulated disposal. Since nearly all industry now produces some waste and no one expects industry to shut down to resolve the waste problem, other strategies need to be available to deal with the problem at the front end. This paper discusses alternative strategies.

  17. Uranium isotopes fingerprint biotic reduction.

    PubMed

    Stylo, Malgorzata; Neubert, Nadja; Wang, Yuheng; Monga, Nikhil; Romaniello, Stephen J; Weyer, Stefan; Bernier-Latmani, Rizlan

    2015-05-05

    Knowledge of paleo-redox conditions in the Earth's history provides a window into events that shaped the evolution of life on our planet. The role of microbial activity in paleo-redox processes remains unexplored due to the inability to discriminate biotic from abiotic redox transformations in the rock record. The ability to deconvolute these two processes would provide a means to identify environmental niches in which microbial activity was prevalent at a specific time in paleo-history and to correlate specific biogeochemical events with the corresponding microbial metabolism. Here, we demonstrate that the isotopic signature associated with microbial reduction of hexavalent uranium (U), i.e., the accumulation of the heavy isotope in the U(IV) phase, is readily distinguishable from that generated by abiotic uranium reduction in laboratory experiments. Thus, isotope signatures preserved in the geologic record through the reductive precipitation of uranium may provide the sought-after tool to probe for biotic processes. Because uranium is a common element in the Earth's crust and a wide variety of metabolic groups of microorganisms catalyze the biological reduction of U(VI), this tool is applicable to a multiplicity of geological epochs and terrestrial environments. The findings of this study indicate that biological activity contributed to the formation of many authigenic U deposits, including sandstone U deposits of various ages, as well as modern, Cretaceous, and Archean black shales. Additionally, engineered bioremediation activities also exhibit a biotic signature, suggesting that, although multiple pathways may be involved in the reduction, direct enzymatic reduction contributes substantially to the immobilization of uranium.

  18. Uranium isotopes fingerprint biotic reduction

    DOE PAGES

    Stylo, Malgorzata; Neubert, Nadja; Wang, Yuheng; ...

    2015-04-20

    Knowledge of paleo-redox conditions in the Earth’s history provides a window into events that shaped the evolution of life on our planet. The role of microbial activity in paleo-redox processes remains unexplored due to the inability to discriminate biotic from abiotic redox transformations in the rock record. The ability to deconvolute these two processes would provide a means to identify environmental niches in which microbial activity was prevalent at a specific time in paleo-history and to correlate specific biogeochemical events with the corresponding microbial metabolism. Here, we demonstrate that the isotopic signature associated with microbial reduction of hexavalent uranium (U),more » i.e., the accumulation of the heavy isotope in the U(IV) phase, is readily distinguishable from that generated by abiotic uranium reduction in laboratory experiments. Thus, isotope signatures preserved in the geologic record through the reductive precipitation of uranium may provide the sought-after tool to probe for biotic processes. Because uranium is a common element in the Earth’s crust and a wide variety of metabolic groups of microorganisms catalyze the biological reduction of U(VI), this tool is applicable to a multiplicity of geological epochs and terrestrial environments. The findings of this study indicate that biological activity contributed to the formation of many authigenic U deposits, including sandstone U deposits of various ages, as well as modern, Cretaceous, and Archean black shales. In addition, engineered bioremediation activities also exhibit a biotic signature, suggesting that, although multiple pathways may be involved in the reduction, direct enzymatic reduction contributes substantially to the immobilization of uranium.« less

  19. Uranium isotopes fingerprint biotic reduction

    SciTech Connect

    Stylo, Malgorzata; Neubert, Nadja; Wang, Yuheng; Monga, Nikhil; Romaniello, Stephen J.; Weyer, Stefan; Bernier-Latmani, Rizlan

    2015-04-20

    Knowledge of paleo-redox conditions in the Earth’s history provides a window into events that shaped the evolution of life on our planet. The role of microbial activity in paleo-redox processes remains unexplored due to the inability to discriminate biotic from abiotic redox transformations in the rock record. The ability to deconvolute these two processes would provide a means to identify environmental niches in which microbial activity was prevalent at a specific time in paleo-history and to correlate specific biogeochemical events with the corresponding microbial metabolism. Here, we demonstrate that the isotopic signature associated with microbial reduction of hexavalent uranium (U), i.e., the accumulation of the heavy isotope in the U(IV) phase, is readily distinguishable from that generated by abiotic uranium reduction in laboratory experiments. Thus, isotope signatures preserved in the geologic record through the reductive precipitation of uranium may provide the sought-after tool to probe for biotic processes. Because uranium is a common element in the Earth’s crust and a wide variety of metabolic groups of microorganisms catalyze the biological reduction of U(VI), this tool is applicable to a multiplicity of geological epochs and terrestrial environments. The findings of this study indicate that biological activity contributed to the formation of many authigenic U deposits, including sandstone U deposits of various ages, as well as modern, Cretaceous, and Archean black shales. In addition, engineered bioremediation activities also exhibit a biotic signature, suggesting that, although multiple pathways may be involved in the reduction, direct enzymatic reduction contributes substantially to the immobilization of uranium.

  20. Uranium isotopes fingerprint biotic reduction

    PubMed Central

    Stylo, Malgorzata; Neubert, Nadja; Wang, Yuheng; Monga, Nikhil; Romaniello, Stephen J.; Weyer, Stefan; Bernier-Latmani, Rizlan

    2015-01-01

    Knowledge of paleo-redox conditions in the Earth’s history provides a window into events that shaped the evolution of life on our planet. The role of microbial activity in paleo-redox processes remains unexplored due to the inability to discriminate biotic from abiotic redox transformations in the rock record. The ability to deconvolute these two processes would provide a means to identify environmental niches in which microbial activity was prevalent at a specific time in paleo-history and to correlate specific biogeochemical events with the corresponding microbial metabolism. Here, we demonstrate that the isotopic signature associated with microbial reduction of hexavalent uranium (U), i.e., the accumulation of the heavy isotope in the U(IV) phase, is readily distinguishable from that generated by abiotic uranium reduction in laboratory experiments. Thus, isotope signatures preserved in the geologic record through the reductive precipitation of uranium may provide the sought-after tool to probe for biotic processes. Because uranium is a common element in the Earth’s crust and a wide variety of metabolic groups of microorganisms catalyze the biological reduction of U(VI), this tool is applicable to a multiplicity of geological epochs and terrestrial environments. The findings of this study indicate that biological activity contributed to the formation of many authigenic U deposits, including sandstone U deposits of various ages, as well as modern, Cretaceous, and Archean black shales. Additionally, engineered bioremediation activities also exhibit a biotic signature, suggesting that, although multiple pathways may be involved in the reduction, direct enzymatic reduction contributes substantially to the immobilization of uranium. PMID:25902522

  1. Solving Problems Reductively

    ERIC Educational Resources Information Center

    Armoni, Michal; Gal-Ezer, Judith; Tirosh, Dina

    2005-01-01

    Solving problems by reduction is an important issue in mathematics and science education in general (both in high school and in college or university) and particularly in computer science education. Developing reductive thinking patterns is an important goal in any scientific discipline, yet reduction is not an easy subject to cope with. Still,…

  2. Microbial reduction of iron ore

    DOEpatents

    Hoffmann, M.R.; Arnold, R.G.; Stephanopoulos, G.

    1989-11-14

    A process is provided for reducing iron ore by treatment with microorganisms which comprises forming an aqueous mixture of iron ore, microorganisms operable for reducing the ferric iron of the iron ore to ferrous iron, and a substrate operable as an energy source for the microbial reduction; and maintaining the aqueous mixture for a period of time and under conditions operable to effect the reduction of the ore. Preferably the microorganism is Pseudomonas sp. 200 and the reduction conducted anaerobically with a domestic wastewater as the substrate. An aqueous solution containing soluble ferrous iron can be separated from the reacted mixture, treated with a base to precipitate ferrous hydroxide which can then be recovered as a concentrated slurry. 11 figs.

  3. Microbial reduction of iron ore

    DOEpatents

    Hoffmann, Michael R.; Arnold, Robert G.; Stephanopoulos, Gregory

    1989-01-01

    A process is provided for reducing iron ore by treatment with microorganisms which comprises forming an aqueous mixture of iron ore, microorganisms operable for reducing the ferric iron of the iron ore to ferrous iron, and a substrate operable as an energy source for the microbial reduction; and maintaining the aqueous mixture for a period of time and under conditions operable to effect the reduction of the ore. Preferably the microorganism is Pseudomonas sp. 200 and the reduction conducted anaerobically with a domestic wastewater as the substrate. An aqueous solution containing soluble ferrous iron can be separated from the reacted mixture, treated with a base to precipitate ferrous hydroxide which can then be recovered as a concentrated slurry.

  4. Characterization of nickel laterite reduction from Pomalaa, Sulawesi Tenggara

    NASA Astrophysics Data System (ADS)

    Rhamdani, Ahmad Rizky; Petrus, Himawan T. B. M.; Fahrurrozi, Moh.

    2015-12-01

    The effect of using different reductors in the reduction process of nickel laterite was investigated. In this work, the author conducted the reduction of nickel laterite ores by anthracite coal, lamtoro charcoal, and carbon raiser, in air and CO2 atmosphere, within the temperature ranged from 800°C and 1000°C. The results indicate that at higher temperatures, the reduction reactions proceed more complete. According to the X-ray powder diffraction (XRD) analysis, the type of carbon used greatly influence the rate of the reduction of nickel laterite. The order of reactivity is anthracite coal, lamtoro charcoal, and carbon raiser, respectively. The reduction atmospheric condition also greatly influences the reduction process. The reduction process in CO2 atmospheric condition gives a lot of significant decrease in hematite and magnetite presence, means that the reduction reactions proceed more complete compared to the reduction process in the air atmospheric condition.

  5. Characterization of nickel laterite reduction from Pomalaa, Sulawesi Tenggara

    SciTech Connect

    Rhamdani, Ahmad Rizky; Petrus, Himawan T. B. M. Fahrurrozi, Moh.

    2015-12-29

    The effect of using different reductors in the reduction process of nickel laterite was investigated. In this work, the author conducted the reduction of nickel laterite ores by anthracite coal, lamtoro charcoal, and carbon raiser, in air and CO{sub 2} atmosphere, within the temperature ranged from 800°C and 1000°C. The results indicate that at higher temperatures, the reduction reactions proceed more complete. According to the X-ray powder diffraction (XRD) analysis, the type of carbon used greatly influence the rate of the reduction of nickel laterite. The order of reactivity is anthracite coal, lamtoro charcoal, and carbon raiser, respectively. The reduction atmospheric condition also greatly influences the reduction process. The reduction process in CO{sub 2} atmospheric condition gives a lot of significant decrease in hematite and magnetite presence, means that the reduction reactions proceed more complete compared to the reduction process in the air atmospheric condition.

  6. Iodine retention during evaporative volume reduction

    DOEpatents

    Godbee, H.W.; Cathers, G.I.; Blanco, R.E.

    1975-11-18

    An improved method for retaining radioactive iodine in aqueous waste solutions during volume reduction is disclosed. The method applies to evaporative volume reduction processes whereby the decontaminated (evaporated) water can be returned safely to the environment. The method generally comprises isotopically diluting the waste solution with a nonradioactive iodide and maintaining the solution at a high pH during evaporation.

  7. Late-onset temperature reduction can retard the aging process in aged fish via a combined action of an anti-oxidant system and the insulin/insulin-like growth factor 1 signaling pathway.

    PubMed

    Wang, Xia; Chang, Qingyun; Wang, Yu; Su, Feng; Zhang, Shicui

    2014-12-01

    Two different mechanisms are considered to be related to aging. Cumulative molecular damage caused by reactive oxygen species (ROS), the by-products of oxidative phosphorylation, is one of these mechanisms (ROS concept). Deregulated nutrient sensing by the insulin/insulin-like growth factor 1 (IGF-1) signaling (IIS) pathway is the second mechanism (IIS concept). Temperature reduction (TR) is known to modulate aging and prolong life span in a variety of organisms, but the mechanisms remain poorly defined. Here we first demonstrate that late-onset TR from 26 °C to 22 °C extends mean life span and maximum life span by approximately 5.2 and 3 weeks, respectively, in the annual fish Nothobranchius guentheri. We then show that TR is able to decrease the accumulation of the histological aging markers senescence-associated β-galactosidase (SA-β-Gal) in the epithelium and lipofuscin (LF) in the liver and to reduce protein oxidation and lipid peroxidation levels in the muscle. We also show that TR can enhance the activities of catalase, glutathione peroxidase, and superoxide dismutase, and stimulate the synthesis of SirT1 and FOXO3A/FOXO1A, both of which are the downstream regulators of the IIS pathway. Taken together, our findings suggest that late-onset TR, a simple non-intrusion intervention, can retard the aging process in aged fish, resulting in their life span extension, via a synergistic action of an anti-oxidant system and the IIS pathway. This also suggests that combined assessment of the ROS and IIS concepts will contribute to providing a more comprehensive view of the anti-aging process.

  8. Late-Onset Temperature Reduction Can Retard the Aging Process in Aged Fish Via a Combined Action of an Anti-Oxidant System and the Insulin/Insulin-Like Growth Factor 1 Signaling Pathway

    PubMed Central

    Wang, Xia; Chang, Qingyun; Wang, Yu; Su, Feng

    2014-01-01

    Abstract Two different mechanisms are considered to be related to aging. Cumulative molecular damage caused by reactive oxygen species (ROS), the by-products of oxidative phosphorylation, is one of these mechanisms (ROS concept). Deregulated nutrient sensing by the insulin/insulin-like growth factor 1 (IGF-1) signaling (IIS) pathway is the second mechanism (IIS concept). Temperature reduction (TR) is known to modulate aging and prolong life span in a variety of organisms, but the mechanisms remain poorly defined. Here we first demonstrate that late-onset TR from 26°C to 22°C extends mean life span and maximum life span by approximately 5.2 and 3 weeks, respectively, in the annual fish Nothobranchius guentheri. We then show that TR is able to decrease the accumulation of the histological aging markers senescence-associated β-galactosidase (SA-β-Gal) in the epithelium and lipofuscin (LF) in the liver and to reduce protein oxidation and lipid peroxidation levels in the muscle. We also show that TR can enhance the activities of catalase, glutathione peroxidase, and superoxide dismutase, and stimulate the synthesis of SirT1 and FOXO3A/FOXO1A, both of which are the downstream regulators of the IIS pathway. Taken together, our findings suggest that late-onset TR, a simple non-intrusion intervention, can retard the aging process in aged fish, resulting in their life span extension, via a synergistic action of an anti-oxidant system and the IIS pathway. This also suggests that combined assessment of the ROS and IIS concepts will contribute to providing a more comprehensive view of the anti-aging process. PMID:25298234

  9. The Effect of Carbonaceous Reductant Selection on Chromite Pre-reduction

    NASA Astrophysics Data System (ADS)

    Kleynhans, E. L. J.; Beukes, J. P.; Van Zyl, P. G.; Bunt, J. R.; Nkosi, N. S. B.; Venter, M.

    2016-12-01

    Ferrochrome (FeCr) production is an energy-intensive process. Currently, the pelletized chromite pre-reduction process, also referred to as solid-state reduction of chromite, is most likely the FeCr production process with the lowest specific electricity consumption, i.e., MWh/t FeCr produced. In this study, the effects of carbonaceous reductant selection on chromite pre-reduction and cured pellet strength were investigated. Multiple linear regression analysis was employed to evaluate the effect of reductant characteristics on the aforementioned two parameters. This yielded mathematical solutions that can be used by FeCr producers to select reductants more optimally in future. Additionally, the results indicated that hydrogen (H)- (24 pct) and volatile content (45.8 pct) were the most significant contributors for predicting variance in pre-reduction and compressive strength, respectively. The role of H within this context is postulated to be linked to the ability of a reductant to release H that can induce reduction. Therefore, contrary to the current operational selection criteria, the authors believe that thermally untreated reductants (e.g., anthracite, as opposed to coke or char), with volatile contents close to the currently applied specification (to ensure pellet strength), would be optimal, since it would maximize H content that would enhance pre-reduction.

  10. The Effect of Carbonaceous Reductant Selection on Chromite Pre-reduction

    NASA Astrophysics Data System (ADS)

    Kleynhans, E. L. J.; Beukes, J. P.; Van Zyl, P. G.; Bunt, J. R.; Nkosi, N. S. B.; Venter, M.

    2017-04-01

    Ferrochrome (FeCr) production is an energy-intensive