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Sample records for precipitation separations process

  1. SEPARATION PROCESS

    DOEpatents

    Stoughton, R.W.

    1961-10-24

    A process for separating tetravalent plutonium from aqueous solutions and from niobium and zirconium by precipitation on lanthanum oxalate is described. The oxalate ions of the precipitate may be decomposed by heating in the presence of an oxidizing agent, forming a plutonium compound readily soluble in acid. (AEC)

  2. PROCESS FOR SEPARATING PLUTONIUM BY REPEATED PRECIPITATION WITH AMPHOTERIC HYDROXIDE CARRIERS

    DOEpatents

    Faris, B.F.

    1960-04-01

    A multiple carrier precipitation method is described for separating and recovering plutonium from an aqueous solution. The hydroxide of an amphoteric metal is precipitated in an aqueous plutonium-containing solution. This precipitate, which carries plutonium, is then separated from the supernatant liquid and dissolved in an aqueous hydroxide solution, forming a second plutonium- containing solution. lons of an amphoteric metal which forms an insoluble hydroxide under the conditions existing in this second solution are added to the second solution. The precipitate which forms and which carries plutonium is separated from the supernatant liquid. Amphoteric metals which may be employed are aluminum, bibmuth, copper, cobalt, iron, lanthanum, nickel, and zirconium.

  3. PRECIPITATION METHOD OF SEPARATION OF NEPTUNIUM

    DOEpatents

    Magnusson, L.B.

    1958-07-01

    A process is described for the separation of neptunium from plutonium in an aqueous solution containing neptunium ions in a valence state not greater than +4, plutonium ioms in a valence state not greater than +4, and sulfate ions. The Process consists of adding hypochlorite ions to said solution in order to preferentially oxidize the neptunium and then adding lanthanum ions and fluoride ions to form a precipitate of LaF/sub 3/ carrying the plutonium, and thereafter separating the supernatant solution from the precipitate.

  4. URANIUM PRECIPITATION PROCESS

    DOEpatents

    Thunaes, A.; Brown, E.A.; Smith, H.W.; Simard, R.

    1957-12-01

    A method for the recovery of uranium from sulfuric acid solutions is described. In the present process, sulfuric acid is added to the uranium bearing solution to bring the pH to between 1 and 1.8, preferably to about 1.4, and aluminum metal is then used as a reducing agent to convert hexavalent uranium to the tetravalent state. As the reaction proceeds, the pH rises amd a selective precipitation of uranium occurs resulting in a high grade precipitate. This process is an improvement over the process using metallic iron, in that metallic aluminum reacts less readily than metallic iron with sulfuric acid, thus avoiding consumption of the reducing agent and a raising of the pH without accomplishing the desired reduction of the hexavalent uranium in the solution. Another disadvantage to the use of iron is that positive ferric ions will precipitate with negative phosphate and arsenate ions at the pH range employed.

  5. DISSOLUTION OF PLUTONIUM CONTAINING CARRIER PRECIPITATE BY CARBONATE METATHESIS AND SEPARATION OF SULFIDE IMPURITIES THEREFROM BY SULFIDE PRECIPITATION

    DOEpatents

    Duffield, R.B.

    1959-07-14

    A process is described for recovering plutonium from foreign products wherein a carrier precipitate of lanthanum fluoride containing plutonium is obtained and includes the steps of dissolving the carrier precipitate in an alkali metal carbonate solution, adding a soluble sulfide, separating the sulfide precipitate, adding an alkali metal hydroxide, separating the resulting precipitate, washing, and dissolving in a strong acid.

  6. BASIC PEROXIDE PRECIPITATION METHOD OF SEPARATING PLUTONIUM FROM CONTAMINANTS

    DOEpatents

    Seaborg, G.T.; Perlman, I.

    1959-02-10

    A process is described for the separation from each other of uranyl values, tetravalent plutonium values and fission products contained in an aqueous acidic solution. First the pH of the solution is adjusted to between 2.5 and 8 and hydrogen peroxide is then added to the solution causing precipitation of uranium peroxide which carries any plutonium values present, while the fission products remain in solution. Separation of the uranium and plutonium values is then effected by dissolving the peroxide precipitate in an acidic solution and incorporating a second carrier precipitate, selective for plutonium. The plutonium values are thus carried from the solution while the uranium remains flissolved. The second carrier precipitate may be selected from among the group consisting of rare earth fluorides, and oxalates, zirconium phosphate, and bismuth lihosphate.

  7. PRECIPITATION METHOD OF SEPARATING PLUTONIUM FROM CONTAMINATING ELEMENTS

    DOEpatents

    Sutton, J.B.

    1958-02-18

    This patent relates to an improved method for the decontamination of plutonium. The process consists broadly in an improvement in a method for recovering plutonium from radioactive uranium fission products in aqueous solutions by decontamination steps including byproduct carrier precipitation comprising the step of introducing a preformed aqueous slurry of a hydroxide of a metal of group IV B into any aqueous acidic solution which contains the plutonium in the hexavalent state, radioactive uranium fission products contaminant and a by-product carrier precipitate and separating the metal hydroxide and by-product precipitate from the solution. The process of this invention is especially useful in the separation of plutonium from radioactive zirconium and columbium fission products.

  8. IMPROVED PROCESS OF PLUTONIUM CARRIER PRECIPITATION

    DOEpatents

    Faris, B.F.

    1959-06-30

    This patent relates to an improvement in the bismuth phosphate process for separating and recovering plutonium from neutron irradiated uranium, resulting in improved decontamination even without the use of scavenging precipitates in the by-product precipitation step and subsequently more complete recovery of the plutonium in the product precipitation step. This improvement is achieved by addition of fluomolybdic acid, or a water soluble fluomolybdate, such as the ammonium, sodium, or potassium salt thereof, to the aqueous nitric acid solution containing tetravalent plutonium ions and contaminating fission products, so as to establish a fluomolybdate ion concentration of about 0.05 M. The solution is then treated to form the bismuth phosphate plutonium carrying precipitate.

  9. Gas-separation process

    DOEpatents

    Toy, Lora G.; Pinnau, Ingo; Baker, Richard W.

    1994-01-01

    A process for separating condensable organic components from gas streams. The process makes use of a membrane made from a polymer material that is glassy and that has an unusually high free volume within the polymer material.

  10. Isothermal separation processes

    NASA Technical Reports Server (NTRS)

    England, C.

    1982-01-01

    The isothermal processes of membrane separation, supercritical extraction and chromatography were examined using availability analysis. The general approach was to derive equations that identified where energy is consumed in these processes and how they compare with conventional separation methods. These separation methods are characterized by pure work inputs, chiefly in the form of a pressure drop which supplies the required energy. Equations were derived for the energy requirement in terms of regular solution theory. This approach is believed to accurately predict the work of separation in terms of the heat of solution and the entropy of mixing. It can form the basis of a convenient calculation method for optimizing membrane and solvent properties for particular applications. Calculations were made on the energy requirements for a membrane process separating air into its components.

  11. Gas-separation process

    DOEpatents

    Toy, L.G.; Pinnau, I.; Baker, R.W.

    1994-01-25

    A process is described for separating condensable organic components from gas streams. The process makes use of a membrane made from a polymer material that is glassy and that has an unusually high free volume within the polymer material. 6 figures.

  12. SEPARATION PROCESS FOR THORIUM SALTS

    DOEpatents

    Bridger, G.L.; Whatley, M.E.; Shaw, K.G.

    1957-12-01

    A process is described for the separation of uranium, thorium, and rare earths extracted from monazite by digesting with sulfuric acid. By carefully increasing the pH of the solution, stepwise, over the range 0.8 to 5.5, a series of selective precipitations will be achieved, with the thorium values coming out at lower pH, the rare earths at intermediate pH and the uranium last. Some mixed precipitates will be obtained, and these may be treated by dissolving in HNO/sub 3/ and contacting with dibutyl phosphate, whereby thorium or uranium are taken up by the organic phase while the rare earths preferentially remain in the aqueous solution.

  13. SEPARATION OF FISSION PRODUCTS FROM PLUTONIUM BY PRECIPITATION

    DOEpatents

    Seaborg, G.T.; Thompson, S.G.; Davidson, N.R.

    1959-09-01

    Fission product separation from hexavalent plutonium by bismuth phosphate precipitation of the fission products is described. The precipitation, according to this invention, is improved by coprecipitating ceric and zirconium phosphates (0.05 to 2.5 grams/liter) with the bismuth phosphate.

  14. ARSENATE CARRIER PRECIPITATION METHOD OF SEPARATING PLUTONIUM FROM NEUTRON IRRADIATED URANIUM AND RADIOACTIVE FISSION PRODUCTS

    DOEpatents

    Thompson, S.G.; Miller, D.R.; James, R.A.

    1961-06-20

    A process is described for precipitating Pu from an aqueous solution as the arsenate, either per se or on a bismuth arsenate carrier, whereby a separation from uranium and fission products, if present in solution, is accomplished.

  15. Membrane separation processes

    SciTech Connect

    Rautenbach, R.; Albrecht, R.

    1989-01-01

    The success of two membrane processes, reverse osmosis and ultrafiltration, has helped make membrane processes a central technique in solving separation problems for fluid systems. This book discusses the various applications and developments in membrane technology and shows how accurate membrane processes can be designed. Starting with the local transport phenomena, the behavior of individual elements such as tube or plate membrane and the behavior of the technical unit - the module - are discussed in detail. The book goes on to demonstrate the most effective ways of arranging modules for forming an optimal plant.

  16. Processes to separate enantiomers.

    PubMed

    Lorenz, Heike; Seidel-Morgenstern, Andreas

    2014-01-27

    The provision of pure enantiomers is of increasing importance not only for the pharmaceutical industry but also for agrochemistry and biotechnology. In general, there are two rival approaches to provide pure enantiomers. The "chiral" approach is based on developing an asymmetric synthesis of just one of the enantiomers, while the "racemic" approach is based on separating mixtures of the two enantiomers. In the last few years remarkable progress has been achieved in the latter area. This Review focuses in particular on enantioselective crystallization processes and preparative chromatography, including hybrid processes and the incorporation of racemization steps. Several examples from our research are used for illustration purposes.

  17. Cyclic membrane separation process

    DOEpatents

    Nemser, Stuart M.

    2005-05-03

    A cyclic process for controlling environmental emissions of volatile organic compounds (VOC) from vapor recovery in storage and dispensing operations of liquids maintains a vacuum in the storage tank ullage. In the first part of a two-part cyclic process ullage vapor is discharged through a vapor recovery system in which VOC are stripped from vented gas with a selectively gas permeable membrane. In the second part, the membrane is inoperative while gas pressure rises in the ullage. In one aspect of this invention, a vacuum is drawn in the membrane separation unit thus reducing overall VOC emissions.

  18. POLONIUM SEPARATION PROCESS

    DOEpatents

    Karraker, D.G.

    1959-07-14

    A liquid-liquid extraction process is presented for the recovery of polonium from lead and bismuth. According to the invention an acidic aqueous chloride phase containing the polonium, lead, and bismuth values is contacted with a tributyl phosphate ether phase. The polonium preferentially enters the organic phase which is then separated and washed with an aqueous hydrochloric solution to remove any lead or bismuth which may also have been extracted. The now highly purified polonium in the organic phase may be transferred to an aqueous solution by extraction with aqueous nitric acid.

  19. Precipitation Process and Apparatus Therefor

    DOEpatents

    Stang, Jr, L C

    1950-12-05

    This invention concerns an apparatus for remotely-controlled precipitation and filtration operations. Liquid within a precipitation chamber is maintained above a porous member by introducing air beneath the member; pressure beneath the porous member is reduced to suck the liquid through the member and effect filtration.

  20. PRECIPITATION METHOD OF SEPARATING PLUTONIUM FROM CONTAMINATING ELEMENTS

    DOEpatents

    Duffield, R.B.

    1959-02-24

    S>A method is described for separating plutonium, in a valence state of less than five, from an aqueous solution in which it is dissolved. The niethod consists in adding potassium and sulfate ions to such a solution while maintaining the solution at a pH of less than 7.1, and isolating the precipitate of potassium plutonium sulfate thus formed.

  1. Hydrogen separation process

    DOEpatents

    Mundschau, Michael; Xie, Xiaobing; Evenson, IV, Carl; Grimmer, Paul; Wright, Harold

    2011-05-24

    A method for separating a hydrogen-rich product stream from a feed stream comprising hydrogen and at least one carbon-containing gas, comprising feeding the feed stream, at an inlet pressure greater than atmospheric pressure and a temperature greater than 200.degree. C., to a hydrogen separation membrane system comprising a membrane that is selectively permeable to hydrogen, and producing a hydrogen-rich permeate product stream on the permeate side of the membrane and a carbon dioxide-rich product raffinate stream on the raffinate side of the membrane. A method for separating a hydrogen-rich product stream from a feed stream comprising hydrogen and at least one carbon-containing gas, comprising feeding the feed stream, at an inlet pressure greater than atmospheric pressure and a temperature greater than 200.degree. C., to an integrated water gas shift/hydrogen separation membrane system wherein the hydrogen separation membrane system comprises a membrane that is selectively permeable to hydrogen, and producing a hydrogen-rich permeate product stream on the permeate side of the membrane and a carbon dioxide-rich product raffinate stream on the raffinate side of the membrane. A method for pretreating a membrane, comprising: heating the membrane to a desired operating temperature and desired feed pressure in a flow of inert gas for a sufficient time to cause the membrane to mechanically deform; decreasing the feed pressure to approximately ambient pressure; and optionally, flowing an oxidizing agent across the membrane before, during, or after deformation of the membrane. A method of supporting a hydrogen separation membrane system comprising selecting a hydrogen separation membrane system comprising one or more catalyst outer layers deposited on a hydrogen transport membrane layer and sealing the hydrogen separation membrane system to a porous support.

  2. URANIUM SEPARATION PROCESS

    DOEpatents

    Lyon, W.L.

    1962-04-17

    A method of separating uranium oxides from PuO/sub 2/, ThO/sub 2/, and other actinide oxides is described. The oxide mixture is suspended in a fused salt melt and a chlorinating agent such as chlorine gas or phosgene is sparged through the suspension. Uranium oxides are selectively chlorinated and dissolve in the melt, which may then be filtered to remove the unchlorinated oxides of the other actinides. (AEC)

  3. URANIUM SEPARATION PROCESS

    DOEpatents

    Hyde, E.K.; Katzin, L.I.; Wolf, M.J.

    1959-07-14

    The separation of uranium from a mixture of uranium and thorium by organic solvent extraction from an aqueous solution is described. The uranium is separrted from an aqueous mixture of uranium and thorium nitrates 3 N in nitric acid and containing salting out agents such as ammonium nitrate, so as to bring ihe total nitrate ion concentration to a maximum of about 8 N by contacting the mixture with an immiscible aliphatic oxygen containing organic solvent such as diethyl carbinol, hexone, n-amyl acetate and the like. The uranium values may be recovered from the organic phase by back extraction with water.

  4. Separation process using microchannel technology

    DOEpatents

    Tonkovich, Anna Lee; Perry, Steven T.; Arora, Ravi; Qiu, Dongming; Lamont, Michael Jay; Burwell, Deanna; Dritz, Terence Andrew; McDaniel, Jeffrey S.; Rogers, Jr.; William A.; Silva, Laura J.; Weidert, Daniel J.; Simmons, Wayne W.; Chadwell, G. Bradley

    2009-03-24

    The disclosed invention relates to a process and apparatus for separating a first fluid from a fluid mixture comprising the first fluid. The process comprises: (A) flowing the fluid mixture into a microchannel separator in contact with a sorption medium, the fluid mixture being maintained in the microchannel separator until at least part of the first fluid is sorbed by the sorption medium, removing non-sorbed parts of the fluid mixture from the microchannel separator; and (B) desorbing first fluid from the sorption medium and removing desorbed first fluid from the microchannel separator. The process and apparatus are suitable for separating nitrogen or methane from a fluid mixture comprising nitrogen and methane. The process and apparatus may be used for rejecting nitrogen in the upgrading of sub-quality methane.

  5. Three phase downhole separator process

    DOEpatents

    Cognata, Louis John

    2008-06-24

    Three Phase Downhole Separator Process (TPDSP) is a process which results in the separation of all three phases, (1) oil, (2) gas, and (3) water, at the downhole location in the well bore, water disposal injection downhole, and oil and gas production uphole.

  6. PROCESS OF TREATING OR FORMING AN INSOLUBLE PLUTONIUM PRECIPITATE IN THE PRESENCE OF AN ORGANIC ACTIVE AGENT

    DOEpatents

    Balthis, J.H.

    1961-07-18

    Carrier precipitation processes for the separation of plutonium from fission products are described. In a process in which an insoluble precipitate is formed in a solution containing plutonium and fission products under conditions whereby plutonium is carried by the precipitate, and the precipitate is then separated from the remaining solution, an organic surface active agent is added to the mixture of precipitate and solution prior to separation of the precipitate from the supernatant solution, thereby improving the degree of separation of the precipitate from the solution.

  7. Methane/nitrogen separation process

    DOEpatents

    Baker, R.W.; Lokhandwala, K.A.; Pinnau, I.; Segelke, S.

    1997-09-23

    A membrane separation process is described for treating a gas stream containing methane and nitrogen, for example, natural gas. The separation process works by preferentially permeating methane and rejecting nitrogen. The authors have found that the process is able to meet natural gas pipeline specifications for nitrogen, with acceptably small methane loss, so long as the membrane can exhibit a methane/nitrogen selectivity of about 4, 5 or more. This selectivity can be achieved with some rubbery and super-glassy membranes at low temperatures. The process can also be used for separating ethylene from nitrogen. 11 figs.

  8. Methane/nitrogen separation process

    DOEpatents

    Baker, Richard W.; Lokhandwala, Kaaeid A.; Pinnau, Ingo; Segelke, Scott

    1997-01-01

    A membrane separation process for treating a gas stream containing methane and nitrogen, for example, natural gas. The separation process works by preferentially permeating methane and rejecting nitrogen. We have found that the process is able to meet natural gas pipeline specifications for nitrogen, with acceptably small methane loss, so long as the membrane can exhibit a methane/nitrogen selectivity of about 4, 5 or more. This selectivity can be achieved with some rubbery and super-glassy membranes at low temperatures. The process can also be used for separating ethylene from nitrogen.

  9. Efficient separations & processing crosscutting program

    SciTech Connect

    1996-08-01

    The Efficient Separations and Processing Crosscutting Program (ESP) was created in 1991 to identify, develop, and perfect chemical and physical separations technologies and chemical processes which treat wastes and address environmental problems throughout the DOE complex. The ESP funds several multiyear tasks that address high-priority waste remediation problems involving high-level, low-level, transuranic, hazardous, and mixed (radioactive and hazardous) wastes. The ESP supports applied research and development (R & D) leading to the demonstration or use of these separations technologies by other organizations within the Department of Energy (DOE), Office of Environmental Management.

  10. Magnetic precipitate separation for Ni plating waste liquid using HTS bulk magnets

    NASA Astrophysics Data System (ADS)

    Oka, T.; Kimura, T.; Mimura, D.; Fukazawa, H.; Fukui, S.; Ogawa, J.; Sato, T.; Ooizumi, M.; Yokoyama, K.; Tsujimura, M.; Terasawa, T.

    2013-01-01

    The magnetic separation experiment for recycling the nickel-bearing precipitates in the waste liquid from the electroless plating processes has been practically conducted under the high gradient magnetic separation technique with use of the face-to-face HTS bulk magnet system. A couple of facing magnetic poles containing Sm123 bulk superconductors were activated through the pulsed field magnetization process to 1.86 T at 38 K and 2.00 T at 37 K, respectively. The weakly magnetized metallic precipitates of Ni crystals and Ni-P compounds deposited from the waste solution after heating it and pH controlling. The high gradient magnetic separation technique was employed with the separation channels filled with the stainless steel balls with dimension of 1 and 3 mm in diameter, which periodically moved between and out of the facing magnetic poles. The Ni-bearing precipitates were effectively attracted to the magnetized ferromagnetic balls. We have succeeded in obtaining the separation ratios over 90% under the flow rates less than 1.35 L/min.

  11. PRECIPITATION METHOD FOR THE SEPARATION OF PLUTONIUM AND RARE EARTHS

    DOEpatents

    Thompson, S.G.

    1960-04-26

    A method of purifying plutonium is given. Tetravalent plutonium is precipitated with thorium pyrophosphate, the plutonium is oxidized to the tetravalent state, and then impurities are precipitated with thorium pyrophosphate.

  12. Continuous magnetic separator and process

    DOEpatents

    Oder, Robin R.; Jamison, Russell E.

    2008-04-22

    A continuous magnetic separator and process for separating a slurry comprising magnetic particles into a clarified stream and a thickened stream. The separator has a container with a slurry inlet, an overflow outlet for the discharge of the clarified slurry stream, and an underflow outlet for the discharge of a thickened slurry stream. Magnetic particles in the slurry are attracted to, and slide down, magnetic rods within the container. The slurry is thus separated into magnetic concentrate and clarified slurry. Flow control means can be used to control the ratio of the rate of magnetic concentrate to the rate of clarified slurry. Feed control means can be used to control the rate of slurry feed to the slurry inlet.

  13. 2006 AFS. Separations processes for the power generation industry

    SciTech Connect

    2006-07-01

    The presentations (viewgraph/overheads) or papers discussed separations processes for the power industry under the following subject headings: nuclear, advanced energy and pollution, control systems, FGD, hot gas filtration, air pollution, electrostatic precipitators for particulate removal, filter media, CO{sub 2} capture, advances in filter design and operation, water utilization and treatment and arsenic, and advances in filtration and separation.

  14. METHOD OF SEPARATION OF PLUTONIUM FROM CARRIER PRECIPITATES

    DOEpatents

    Dawson, I.R.

    1959-09-22

    The recovery of plutonium from fluoride carrier precipitates is described. The precipitate is dissolved in zirconyl nitrate, ferric nitrate, aluminum nitrate, or a mixture of these complexing agents, and the plutonium is then extracted from the aqueous solution formed with a water-immiscible organic solvent.

  15. Causal and causally separable processes

    NASA Astrophysics Data System (ADS)

    Oreshkov, Ognyan; Giarmatzi, Christina

    2016-09-01

    outcomes for each party, these correlations form a polytope whose facets define causal inequalities. The case of quantum correlations in this paradigm is captured by the process matrix formalism. We investigate the link between causality and the closely related notion of causal separability of quantum processes, which we here define rigorously in analogy with the link between Bell locality and separability of quantum states. We show that causality and causal separability are not equivalent in general by giving an example of a physically admissible tripartite quantum process that is causal but not causally separable. We also show that there are causally separable quantum processes that become non-causal if extended by supplying the parties with entangled ancillas. This motivates the concepts of extensibly causal and extensibly causally separable (ECS) processes, for which the respective property remains invariant under extension. We characterize the class of ECS quantum processes in the tripartite case via simple conditions on the form of the process matrix. We show that the processes realizable by classically controlled quantum circuits are ECS and conjecture that the reverse also holds.

  16. PROCESS OF SEPARATING PLUTONIUM FROM URANIUM

    DOEpatents

    Brown, H.S.; Hill, O.F.

    1958-09-01

    A process is presented for recovering plutonium values from aqueous solutions. It comprises forming a uranous hydroxide precipitate in such a plutonium bearing solution, at a pH of at least 5. The plutonium values are precipitated with and carried by the uranium hydroxide. The carrier precipitate is then redissolved in acid solution and the pH is adjusted to about 2.5, causing precipitation of the uranous hydroxide but leaving the still soluble plutonium values in solution.

  17. Olefin separation membrane and process

    DOEpatents

    Pinnau, I.; Toy, L.G.; Casillas, C.

    1997-09-23

    A membrane and process are disclosed for separating unsaturated hydrocarbons from fluid mixtures. The membrane and process differ from previously known membranes and processes, in that the feed and permeate streams can both be dry, the membrane need not be water or solvent swollen, and the membrane is characterized by a selectivity for an unsaturated hydrocarbon over a saturated hydrocarbon having the same number of carbon atoms of at least about 20, and a pressure-normalized flux of said unsaturated hydrocarbon of at least about 5{times}10{sup {minus}6}cm{sup 3}(STP)/cm{sup 2}{center_dot}s{center_dot}cmHg, said flux and selectivity being measured with a gas mixture containing said unsaturated and saturated hydrocarbons, and in a substantially dry environment. 4 figs.

  18. Olefin separation membrane and process

    DOEpatents

    Pinnau, Ingo; Toy, Lora G.; Casillas, Carlos

    1997-01-01

    A membrane and process for separating unsaturated hydrocarbons from fluid mixtures. The membrane and process differ from previously known membranes and processes, in that the feed and permeate streams can both be dry, the membrane need not be water or solvent swollen, and the membrane is characterized by a selectivity for an unsaturated hydrocarbon over a saturated hydrocarbon having the same number of carbon atoms of at least about 20, and a pressure-normalized flux of said unsaturated hydrocarbon of at least about 5.times.10.sup.-6 cm.sup.3 (STP)/cm.sup.2 .multidot.s.multidot.cmHg, said flux and selectivity being measured with a gas mixture containing said unsaturated and saturated hydrocarbons, and in a substantially dry environment.

  19. An atom probe perspective on phase separation and precipitation in duplex stainless steels.

    PubMed

    Guo, Wei; Garfinkel, David A; Tucker, Julie D; Haley, Daniel; Young, George A; Poplawsky, Jonathan D

    2016-06-24

    Three-dimensional chemical imaging of Fe-Cr alloys showing Fe-rich (α)/Cr-rich (α') phase separation is reported using atom probe tomography techniques. The extent of phase separation, i.e., amplitude and wavelength, has been quantitatively assessed using the Langer-Bar-on-Miller, proximity histogram, and autocorrelation function methods for two separate Fe-Cr alloys, designated 2101 and 2205. Although the 2101 alloy possesses a larger wavelength and amplitude after annealing at 427 °C for 100-10 000 h, it exhibits a lower hardness than the 2205 alloy. In addition to this phase separation, ultra-fine Ni-Mn-Si-Cu-rich G-phase precipitates form at the α/α' interfaces in both alloys. For the 2101 alloy, Cu clusters act to form a nucleus, around which a Ni-Mn-Si shell develops during the precipitation process. For the 2205 alloy, the Ni and Cu atoms enrich simultaneously and no core-shell chemical distribution was found. This segregation phenomenon may arise from the exact Ni/Cu ratio inside the ferrite. After annealing for 10 000 h, the number density of the G-phase within the 2205 alloy was found to be roughly one order of magnitude higher than in the 2101 alloy. The G-phase precipitates have an additional deleterious effect on the thermal embrittlement, as evaluated by the Ashby-Orowan equation, which explains the discrepancy between the hardness and the rate of phase separation with respect to annealing time (Gladman T 1999 Mater. Sci. Tech. Ser. 15 30-36). PMID:27181108

  20. An atom probe perspective on phase separation and precipitation in duplex stainless steels

    DOE PAGES

    Garfinkel, David A.; Tucker, Julie D.; Haley, Daniel A.; Young, George A.; Guo, Wei; Poplawsky, Jonathan D.

    2016-05-16

    Here, three-dimensional chemical imaging of Fe–Cr alloys showing Fe-rich (α)/Cr-rich (α') phase separation is reported using atom probe tomography techniques. The extent of phase separation, i.e., amplitude and wavelength, has been quantitatively assessed using the Langer-Bar-on-Miller, proximity histogram, and autocorrelation function methods for two separate Fe–Cr alloys, designated 2101 and 2205. Although the 2101 alloy possesses a larger wavelength and amplitude after annealing at 427 °C for 100–10 000 h, it exhibits a lower hardness than the 2205 alloy. In addition to this phase separation, ultra-fine Ni–Mn–Si–Cu-rich G-phase precipitates form at the α/α' interfaces in both alloys. For the 2101more » alloy, Cu clusters act to form a nucleus, around which a Ni–Mn–Si shell develops during the precipitation process. For the 2205 alloy, the Ni and Cu atoms enrich simultaneously and no core–shell chemical distribution was found. This segregation phenomenon may arise from the exact Ni/Cu ratio inside the ferrite. After annealing for 10 000 h, the number density of the G-phase within the 2205 alloy was found to be roughly one order of magnitude higher than in the 2101 alloy. The G-phase precipitates have an additional deleterious effect on the thermal embrittlement, as evaluated by the Ashby–Orowan equation, which explains the discrepancy between the hardness and the rate of phase separation with respect to annealing time (Gladman T 1999 Mater. Sci. Tech. Ser. 15 30–36).« less

  1. An atom probe perspective on phase separation and precipitation in duplex stainless steels

    NASA Astrophysics Data System (ADS)

    Guo, Wei; Garfinkel, David A.; Tucker, Julie D.; Haley, Daniel; Young, George A.; Poplawsky, Jonathan D.

    2016-06-01

    Three-dimensional chemical imaging of Fe–Cr alloys showing Fe-rich (α)/Cr-rich (α‧) phase separation is reported using atom probe tomography techniques. The extent of phase separation, i.e., amplitude and wavelength, has been quantitatively assessed using the Langer-Bar-on-Miller, proximity histogram, and autocorrelation function methods for two separate Fe–Cr alloys, designated 2101 and 2205. Although the 2101 alloy possesses a larger wavelength and amplitude after annealing at 427 °C for 100–10 000 h, it exhibits a lower hardness than the 2205 alloy. In addition to this phase separation, ultra-fine Ni–Mn–Si–Cu-rich G-phase precipitates form at the α/α‧ interfaces in both alloys. For the 2101 alloy, Cu clusters act to form a nucleus, around which a Ni–Mn–Si shell develops during the precipitation process. For the 2205 alloy, the Ni and Cu atoms enrich simultaneously and no core–shell chemical distribution was found. This segregation phenomenon may arise from the exact Ni/Cu ratio inside the ferrite. After annealing for 10 000 h, the number density of the G-phase within the 2205 alloy was found to be roughly one order of magnitude higher than in the 2101 alloy. The G-phase precipitates have an additional deleterious effect on the thermal embrittlement, as evaluated by the Ashby–Orowan equation, which explains the discrepancy between the hardness and the rate of phase separation with respect to annealing time (Gladman T 1999 Mater. Sci. Tech. Ser. 15 30–36). ).

  2. An atom probe perspective on phase separation and precipitation in duplex stainless steels

    NASA Astrophysics Data System (ADS)

    Guo, Wei; Garfinkel, David A.; Tucker, Julie D.; Haley, Daniel; Young, George A.; Poplawsky, Jonathan D.

    2016-06-01

    Three-dimensional chemical imaging of Fe-Cr alloys showing Fe-rich (α)/Cr-rich (α‧) phase separation is reported using atom probe tomography techniques. The extent of phase separation, i.e., amplitude and wavelength, has been quantitatively assessed using the Langer-Bar-on-Miller, proximity histogram, and autocorrelation function methods for two separate Fe-Cr alloys, designated 2101 and 2205. Although the 2101 alloy possesses a larger wavelength and amplitude after annealing at 427 °C for 100-10 000 h, it exhibits a lower hardness than the 2205 alloy. In addition to this phase separation, ultra-fine Ni-Mn-Si-Cu-rich G-phase precipitates form at the α/α‧ interfaces in both alloys. For the 2101 alloy, Cu clusters act to form a nucleus, around which a Ni-Mn-Si shell develops during the precipitation process. For the 2205 alloy, the Ni and Cu atoms enrich simultaneously and no core-shell chemical distribution was found. This segregation phenomenon may arise from the exact Ni/Cu ratio inside the ferrite. After annealing for 10 000 h, the number density of the G-phase within the 2205 alloy was found to be roughly one order of magnitude higher than in the 2101 alloy. The G-phase precipitates have an additional deleterious effect on the thermal embrittlement, as evaluated by the Ashby-Orowan equation, which explains the discrepancy between the hardness and the rate of phase separation with respect to annealing time (Gladman T 1999 Mater. Sci. Tech. Ser. 15 30-36). ).

  3. Alternative separation steps for monoclonal antibody purification: combination of centrifugal partitioning chromatography and precipitation.

    PubMed

    Oelmeier, Stefan A; Ladd-Effio, Christopher; Hubbuch, Jürgen

    2013-12-01

    Protein drugs continue to grow both in medicinal importance as in scale of their production. This furthers the interest in separation technologies that have the potential to replace chromatographic steps in a protein purification process. Two such unit operations that are employed in large scale in the chemical industry are extraction and precipitation. Their usefulness for the purification of proteins has been demonstrated, but the integration of such unit operations in a way that generate an output stream of high protein concentration and low process related impurities was missing. In this work, we employ centrifugal partitioning chromatography ('CPC') in combination with precipitation of the protein of interest to purify a cell culture supernatant of a monoclonal antibody producing cell line. Centrifugal partitioning chromatography was used as means of multi-step extraction using aqueous two-phase systems and was able to remove up to 88.2% of host cell protein ('HCP'). The following PEG driven precipitation and resolubilization of the protein of interest was use to condition the CPC output stream to suit subsequent chromatographic steps, to increase mAb concentration, remove the phase forming polymer, further improve HCP clearance, and integrate a low pH hold step for viral clearance. The entire process reduced HCP content by 99.4% while recovering 93% of the protein of interest. High throughput screening techniques were extensively employed during the development of the process.

  4. Alternative separation steps for monoclonal antibody purification: combination of centrifugal partitioning chromatography and precipitation.

    PubMed

    Oelmeier, Stefan A; Ladd-Effio, Christopher; Hubbuch, Jürgen

    2013-12-01

    Protein drugs continue to grow both in medicinal importance as in scale of their production. This furthers the interest in separation technologies that have the potential to replace chromatographic steps in a protein purification process. Two such unit operations that are employed in large scale in the chemical industry are extraction and precipitation. Their usefulness for the purification of proteins has been demonstrated, but the integration of such unit operations in a way that generate an output stream of high protein concentration and low process related impurities was missing. In this work, we employ centrifugal partitioning chromatography ('CPC') in combination with precipitation of the protein of interest to purify a cell culture supernatant of a monoclonal antibody producing cell line. Centrifugal partitioning chromatography was used as means of multi-step extraction using aqueous two-phase systems and was able to remove up to 88.2% of host cell protein ('HCP'). The following PEG driven precipitation and resolubilization of the protein of interest was use to condition the CPC output stream to suit subsequent chromatographic steps, to increase mAb concentration, remove the phase forming polymer, further improve HCP clearance, and integrate a low pH hold step for viral clearance. The entire process reduced HCP content by 99.4% while recovering 93% of the protein of interest. High throughput screening techniques were extensively employed during the development of the process. PMID:24182866

  5. [Separation and purification of Al13 by chemical precipitation and metathesis].

    PubMed

    Li, Guo-Hong; Shi, Bao-You; Wang, Dong-Sheng; Cui, Ya-Li

    2007-02-01

    PACls with different concentrations were prepared by adding sodium carbonate powder into AlCl13 solution. Medium concentration and high Al13 content of PACl was chosen to carry out Al13 separation processes. The influences of SO4/Al molar ratio and the initial total Al concentration on the precipitation reactions of sulfate with different Al species were investigated. The factors influencing the metathesis reaction between solid Al13-SO4 and Ba(NO3)2 were evaluated. Results showed that high Al13 PACl could be obtained at the medium high concentration range of 0.4 - 0.6 mol/L, the optimum SO4/Al ratio was 0.6:1 for precipitation- separation of Al13, Al13 -SO4 precipitates were mostly consisted of tetrahedral crystals. During the metathesis reaction, Ba/SO4 molar ratio of 1:1 is the optimal value. Small range temperature variation and ultrasonic action had no marked influence on metathesis reaction rate and final Al13 concentration. Higher initial Ba(NO3)2 concentration could produce higher concentration Al13 accordingly. The purity of Al13 solution could be reached to 92.1% statistically.

  6. Process for strontium-82 separation

    SciTech Connect

    Heaton, R.C.; Jamriska, D.J. Sr.; Taylor, W.A.

    1991-12-31

    The process is for the selective separation of Sr-82 and Sr-85 from a proton-irradiated Mo target. It includes dissolving the Mo in H2O2 to form a solution which is then passed through a cationic resin, whereby Mo, Nb, Tc, Se, V, As, Ge, Zr, Rb ions remain in the solution, while Rb, Zn, Be, Co, Fe, Mn, Cr, Sr, Y, Zr ions are adsorbed. The resin is contacted with an acid solution to remove the adsorbed ions, forming a second solution. The second solution is evaporated and the residue dissolved in a dilute acid to form a third solution. After adjusting the acid molarity, the third solution is passed through a second cationic resin; this resin is contacted first with a dilute sulfuric acid solution and then with a dilute acid solution to remove the adsorbed Sr ions. Zr, Rb, and Y radioisotopes can also be recovered with additional steps.

  7. Radioactive demonstration of the ``late wash`` Precipitate Hydrolysis Process

    SciTech Connect

    Bibler, N.E.; Ferrara, D.M.; Ha, B.C.

    1992-06-30

    This report presents results of the radioactive demonstration of the DWPF Precipitate Hydrolysis Process as it would occur in the ``late wash`` flowsheet in the absence of hydroxylamine nitrate. Radioactive precipitate containing Cs-137 from the April, 1983, in-tank precipitation demonstration in Tank 48 was used for these tests.

  8. Radioactive demonstration of the late wash'' Precipitate Hydrolysis Process

    SciTech Connect

    Bibler, N.E.; Ferrara, D.M.; Ha, B.C.

    1992-06-30

    This report presents results of the radioactive demonstration of the DWPF Precipitate Hydrolysis Process as it would occur in the late wash'' flowsheet in the absence of hydroxylamine nitrate. Radioactive precipitate containing Cs-137 from the April, 1983, in-tank precipitation demonstration in Tank 48 was used for these tests.

  9. Process for strontium-82 separation

    DOEpatents

    Heaton, R.C.; Jamriska, D.J. Sr.; Taylor, W.A.

    1992-12-01

    A process for selective separation of strontium-82 and strontium-85 from proton irradiated molybdenum targets comprises dissolving the molybdenum target in a hydrogen peroxide solution to form a first solution containing ions selected from a group consisting of molybdenum, niobium, technetium, selenium, vanadium, arsenic, germanium, zirconium, rubidium, zinc, beryllium, cobalt, iron, manganese, chromium, strontium, and yttrium; passing the solution through a first cationic resin whereby ions selected from a group consisting of zinc, beryllium, cobalt, iron, manganese, chromium, strontium, yttrium a portion of zirconium and a portion of rubidium are selectively absorbed by the first resin; contacting the first resin with an acid solution to strip and remove the absorbed ions from the first cationic exchange resin to form a second solution; evaporating the second solution for a time sufficient to remove substantially all of the acid and water from the solution whereby a residue remains; dissolving the residue in a dilute acid to form a third solution; passing the third solution through a second cationic resin whereby the ions are absorbed by the second resin; contacting the second resin with a dilute sulfuric acid solution whereby the absorbed ions selected from the group consisting of rubidium, zinc, beryllium, cobalt, iron, manganese, chromium and zirconium are selectively removed from the second resin; and contacting the second resin with a dilute acid solution whereby the absorbed strontium ions are selectively removed. 1 fig.

  10. Process for strontium-82 separation

    DOEpatents

    Heaton, Richard C.; Jamriska, Sr., David J.; Taylor, Wayne A.

    1992-01-01

    A process for selective separation of strontium-82 and strontium-85 from proton irradiated molybdenum targets comprises dissolving the molybdenum target in a hydrogen peroxide solution to form a first solution containing ions selected from a group consisting of molybdenum, niobium, technetium, selenium, vanadium, arsenic, germanium, zirconium, rubidium, zinc, beryllium, cobalt, iron, manganese, chromium, strontium, and yttrium; passing the solution through a first cationic resin whereby ions selected from a group consisting of zinc, beryllium, cobalt, iron, manganese, chromium, strontium, yttrium a portion of zirconium and a portion of rubidium are selectively absorbed by the first resin; contacting the first resin with an acid solution to strip and remove the absorbed ions from the first cationic exchange resin to form a second solution; evaporating the second solution for a time sufficient to remove substantially all of the acid and water from the solution whereby a residue remains; dissolving the residue in a dilute acid to form a third solution; passing the third solution through a second cationic resin whereby the ions are absorbed by the second resin; contacting the second resin with a dilute sulfuric acid solution whereby the absorbed ions selected from the group consisting of rubidium, zinc, beryllium, cobalt, iron, manganese, chromium and zirconium are selectively removed from the second resin; and contacting the second resin with a dilute acid solution whereby the absorbed strontium ions are selectively removed.

  11. Struvite precipitation thermodynamics in source-separated urine.

    PubMed

    Ronteltap, Mariska; Maurer, Max; Gujer, Willi

    2007-03-01

    Struvite (MgNH(4)PO(4).6H(2)O) precipitation eliminates phosphate efficiently from urine, a small but highly concentrated stream in the total flux of domestic wastewater. Precipitation experiments with hydrolysed urine evaluated the solubility product of struvite. The stored and fully hydrolysed urine had an ionic strength of between 0.33 and 0.56M and required the estimation of activity coefficients. From our data, we identified the Davies approximation with the two constants A=0.509 and B=0.3 as agreeing best with our laboratory results. The standard solubility product K(s)(0)=f(1)[NH4(+)]f(2)[Mg2+]f(3)[PO(4)(3-)] ([ ]=concentration of the species; f(x)=corresponding activity coefficient) of struvite in urine was found to be 10(-13.26+/-0.057) at 25 degrees C and the enthalpy of struvite formation DeltaH was 22.6(+/-1.1) kJmol(-1). The equilibrium calculations required the following dissolved complexes: [MgCO(3)](aq), [MgHCO(3)](+), [MgPO(4)](-), [NH4HPO4and [NaHPO(4)](-) and to a lesser extent [MgSO(4)](aq) and [NH(4)SO(4)](-). Organic complexes do not seem to influence the solubility product substantially. For practical purposes, a conditional solubility product K(s)(cond)=[Mg(aq)].[NH(4)(+)+NH(3)].[P(ortho)]=10(-7.57)M(3) was derived to calculate struvite solubility in urine at 25 degrees C, pH=9.0 and ionic strength I=0.4M directly from measured concentrations. PMID:17258264

  12. PROCESS FOR THE SEPARATION OF HEAVY METALS

    DOEpatents

    Gofman, J.W.; Connick, R.E.; Wahl, A.C.

    1959-01-27

    A method is presented for thc separation of plutonium from uranium and the fission products with which it is associated. The method is based on the fact that hexavalent plutonium forms an insoluble complex precipitate with sodium acetate, as does the uranyl ion, while reduced plutonium is not precipitated by sodium acetate. Several embodiments are shown, e.g., a solution containing plutonium and uranium in the hexavalent state may be contacted with sodium acetate causing the formation of a sodium uranyl acetate precipitate which carries the plutonium values while the fission products remain in solution. If the original solution is treated with a reducing agent, so that the plutonium is reduced while the uranium remains in the hexavalent state, and sodium and acetate ions are added, the uranium will precipitutc while the plutonium remains in solution effecting separation of the Pu from urarium.

  13. SEPARATION PROCESS FOR TRANSURANIC ELEMENT AND COMPOUNDS THEREOF

    DOEpatents

    Magnusson, L.B.

    1958-04-01

    A process is described for the separation of neptunium, from aqueous solutions of neptunium, plutonium, uraniunn, and fission prcducts. This separation from an acidic aqueous solution of a tetravalent neptuniunn can be made by contacting the solution with a certain type of chelating,; agent, preferably dissolved in an organic solvent, to form a neptunium chelate compound. When the organic solvent is present, the neptunium chelate compound is extracted; otherwise, it precipitates from the aqueous solution and is separated by any suitable means. The chelating agent is a fluorinated BETA -diketone. such as trifluoroacetyl acetone.

  14. Separation of Niobium and Tantalum Pentafluoride by Selective Precipitation Using p-Phenylenediamine

    NASA Astrophysics Data System (ADS)

    Nete, M.; Purcell, W.; Nel, J. T.

    2016-07-01

    The similarity between Ta and Nb chemistry makes it difficult to find the appropriate reagents and chemical reactions for the separation of the two elements. This study investigated the precipitation behavior of TaF5 and NbF5 with p-phenylenediamine (PPDA). PPDA preferentially precipitated Nb from a 1:1 ratio of NbF5 and TaF5. Niobium recoveries of >80%, and only 4% Ta, were found in the precipitate of the reaction between (Nb/Ta)F5 and PPDA in ethanol. A separation factor of 100(9) indicated the potential for successful separation of Nb and Ta in a fluoride environment. A spectrophotometric study of the formation ratio of the newly formed Nb compound indicated a 1:1 metal:ligand ratio.

  15. Mechanistic study and modeling of precipitation scale inhibitor squeeze processes

    SciTech Connect

    Malandrino, A.; Yuan, M.D.; Sorbie, K.S.; Jordan, M.M.

    1995-11-01

    A scale inhibitor precipitation squeeze is one of the two main types of treatment for preventing downhole scale deposition; the other type is an adsorption squeeze. However, unlike for the adsorption squeeze process, the mechanism for inhibitor retention within the formation through precipitation/re-dissolution is not fully understood and it is this issue that is considered in this work. Here, the central objective is to consider a range of possible models of the precipitation squeeze process and to determine which of these are consistent with the available laboratory core flood and field data. Such models range from pure precipitation through to more complex models which couple the precipitation process with an adsorption process or with a mechanical transport phenomenon. The various models are explained in terms of the chemical processes which are observed. Results from two inhibitor precipitation core floods and one field squeeze treatment are presented along with the modeled inhibitor return curves. Based on certain model assumptions, the authors understanding of the process allows them to optimize the squeeze design of both inhibitor solution and operational parameters for extending the precipitation squeeze life time.

  16. PROCESS FOR SEPARATION OF HEAVY METALS

    DOEpatents

    Duffield, R.B.

    1958-04-29

    A method is described for separating plutonium from aqueous acidic solutions of neutron-irradiated uranium and the impurities associated therewith. The separation is effected by adding, to the solution containing hexavalent uranium and plutonium, acetate ions and the ions of an alkali metal and those of a divalent metal and thus forming a complex plutonium acetate salt which is carried by the corresponding complex of uranium, such as sodium magnesium uranyl acetate. The plutonium may be separated from the precipitated salt by taking the same back into solution, reducing the plutonium to a lower valent state on reprecipitating the sodium magnesium uranyl salt, removing the latter, and then carrying the plutonium from ihe solution by means of lanthanum fluoride.

  17. PROCESS USING BISMUTH PHOSPHATE AS A CARRIER PRECIPITATE FOR FISSION PRODUCTS AND PLUTONIUM VALUES

    DOEpatents

    Finzel, T.G.

    1959-03-10

    A process is described for separating plutonium from fission products carried therewith when plutonium in the reduced oxidation state is removed from a nitric acid solution of irradiated uranium by means of bismuth phosphate as a carrier precipitate. The bismuth phosphate carrier precipitate is dissolved by treatment with nitric acid and the plutonium therein is oxidized to the hexavalent oxidation state by means of potassium dichromate. Separation of the plutonium from the fission products is accomplished by again precipitating bismuth phosphate and removing the precipitate which now carries the fission products and a small percentage of the plutonium present. The amount of plutonium carried in this last step may be minimized by addition of sodium fluoride, so as to make the solution 0.03N in NaF, prior to the oxidation and prccipitation step.

  18. Global Precipitation Measurement (GPM) Mission: Precipitation Processing System (PPS) GPM Mission Gridded Text Products Provide Surface Precipitation Retrievals

    NASA Technical Reports Server (NTRS)

    Stocker, Erich Franz; Kelley, O.; Kummerow, C.; Huffman, G.; Olson, W.; Kwiatkowski, J.

    2015-01-01

    In February 2015, the Global Precipitation Measurement (GPM) mission core satellite will complete its first year in space. The core satellite carries a conically scanning microwave imager called the GPM Microwave Imager (GMI), which also has 166 GHz and 183 GHz frequency channels. The GPM core satellite also carries a dual frequency radar (DPR) which operates at Ku frequency, similar to the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar, and a new Ka frequency. The precipitation processing system (PPS) is producing swath-based instantaneous precipitation retrievals from GMI, both radars including a dual-frequency product, and a combined GMIDPR precipitation retrieval. These level 2 products are written in the HDF5 format and have many additional parameters beyond surface precipitation that are organized into appropriate groups. While these retrieval algorithms were developed prior to launch and are not optimal, these algorithms are producing very creditable retrievals. It is appropriate for a wide group of users to have access to the GPM retrievals. However, for researchers requiring only surface precipitation, these L2 swath products can appear to be very intimidating and they certainly do contain many more variables than the average researcher needs. Some researchers desire only surface retrievals stored in a simple easily accessible format. In response, PPS has begun to produce gridded text based products that contain just the most widely used variables for each instrument (surface rainfall rate, fraction liquid, fraction convective) in a single line for each grid box that contains one or more observations.This paper will describe the gridded data products that are being produced and provide an overview of their content. Currently two types of gridded products are being produced: (1) surface precipitation retrievals from the core satellite instruments GMI, DPR, and combined GMIDPR (2) surface precipitation retrievals for the partner constellation

  19. Extraction of rare earth elements from hydrate-phosphate precipitates of apatite processing

    NASA Astrophysics Data System (ADS)

    Andropov, M. O.; Anufrieva, A. V.; Buynovskiy, A. S.; Makaseev, Y. N.; Mazov, I. N.; Nefedov, R. A.; Sachkov, V. I.; Stepanova, O. B.; Valkov, AV

    2016-01-01

    The features of extraction of rare earth elements (REE) were considered from hydrate-phosphate precipitates of REE of apatite processing by nitric acid technology. The preliminary purification of nitrate solution of REE from impurities of titanium, aluminum, iron, uranium and thorium was suggested to obtain stable solutions not forming precipitates. Washing the extract was recommended with the evaporated reextract that allows to obtain directly on the cascade of REE extraction the concentrated solutions suitable for the separation into groups by the extraction method. Technical decisions were suggested for the separation of REE in groups without the use of salting-out agent.

  20. SEPARATION PROCESS FOR PROTACTINIUM AND COMPOUNDS THEREOF

    DOEpatents

    Van Winkle, A.

    1959-07-21

    The separation of protactinium from aqueous solutions from its mixtures with thorium, uranium and fission products is described. The process for the separation comprises preparing an ion nitric acid solution containing protactinium in the pentavalent state and contacting the solution with a fluorinated beta diketone, such as trifluoroacetylacetone, either alone or as an organic solvent solution to form a pentavalent protactinium chelate compound. When the organic solvent is present the chelate compound is extracted; otherwise it is separated by filtration.

  1. Evaluation of separation and purification processes in the antibiotic industry

    SciTech Connect

    Bienkowski, P.R.; Lee, D.D.; Byers, C.H.

    1987-05-01

    The different separation and purification processes for three major types of antibiotics, Penicillins, Cephalosporins and Tetracyclines will be discussed. All antibiotic, processing plants contain two majors sections, a relatively small and highly specialized fermentation section and a very large (60-80% of the plant) separation and purification section. The fermentation sections for the different antibiotics are essentially identical, except for differences in growth media and operating variables, but there are vast differences in the separation and purification sections. Several different separation methods are used including filtration, ultrafiltration, centrifugation, precipitation, extraction, chromatography and various membrane methods. Variables affecting the specific separation and purification configurations include final fermentation broth concentration, by-product formed during fermentation, the physical properties and molecular structure of the various antibiotics and special purification requirements. Necessary reductions in the separation and purification processes required for rebuilding the antibiotic industry after a national emergency are discussed along with several relatively new separation/purification methods that hold great promise for effecting these reductions, chromatography, supercritical fluid extraction (SCF), and membranes. 35 refs., 10 figs., 2 tabs.

  2. Apparatus and process for separating hydrogen isotopes

    DOEpatents

    Heung, Leung K; Sessions, Henry T; Xiao, Xin

    2013-06-25

    The apparatus and process for separating hydrogen isotopes is provided using dual columns, each column having an opposite hydrogen isotopic effect such that when a hydrogen isotope mixture feedstock is cycled between the two respective columns, two different hydrogen isotopes are separated from the feedstock.

  3. 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.

  4. Atomic vapor laser isotope separation process

    DOEpatents

    Wyeth, R.W.; Paisner, J.A.; Story, T.

    1990-08-21

    A laser spectroscopy system is utilized in an atomic vapor laser isotope separation process. The system determines spectral components of an atomic vapor utilizing a laser heterodyne technique. 23 figs.

  5. Supercritical separation process for complex organic mixtures

    DOEpatents

    Chum, Helena L.; Filardo, Giuseppe

    1990-01-01

    A process is disclosed for separating low molecular weight components from complex aqueous organic mixtures. The process includes preparing a separation solution of supercritical carbon dioxide with an effective amount of an entrainer to modify the solvation power of the supercritical carbon dioxide and extract preselected low molecular weight components. The separation solution is maintained at a temperature of at least about 70.degree. C. and a pressure of at least about 1,500 psi. The separation solution is then contacted with the organic mixtures while maintaining the temperature and pressure as above until the mixtures and solution reach equilibrium to extract the preselected low molecular weight components from the organic mixtures. Finally, the entrainer/extracted components portion of the equilibrium mixture is isolated from the separation solution.

  6. Supercritical separation process for complex organic mixtures

    DOEpatents

    Chum, H.L.; Filardo, G.

    1990-10-23

    A process is disclosed for separating low molecular weight components from complex aqueous organic mixtures. The process includes preparing a separation solution of supercritical carbon dioxide with an effective amount of an entrainer to modify the solvation power of the supercritical carbon dioxide and extract preselected low molecular weight components. The separation solution is maintained at a temperature of at least about 70 C and a pressure of at least about 1,500 psi. The separation solution is then contacted with the organic mixtures while maintaining the temperature and pressure as above until the mixtures and solution reach equilibrium to extract the preselected low molecular weight components from the organic mixtures. Finally, the entrainer/extracted components portion of the equilibrium mixture is isolated from the separation solution. 1 fig.

  7. Impact of Urban Surfaces on Precipitation Processes

    NASA Technical Reports Server (NTRS)

    Shepherd, J. M.

    2004-01-01

    The Intergovernmental Panel on Climate Change (IPCC) was established in 1988 by two United Nations organizations, the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) to assess the "risk of human-induced climate change". Such reports are used by decision-makers around the world to assess how our climate is changing. Its reports are widely respected and cited and have been highly influential in forming national and international responses to climate change. The Fourth Assessment report includes a section on the effects of surface processes on climate. This sub-chapter provides an overview of recent developments related to the impact of cities on rainfall. It highlights the possible mechanisms that buildings, urban heat islands, urban aerosols or pollution, and other human factors in cities that can affect rainfall.

  8. The Role of Aerosols on Precipitation Processes

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo; Li, X.; Khain, A.; Simpson, S.

    2006-01-01

    Cloud physics is inevitably affected by the smoke particle (CCN, cloud condensation nuclei) size distribution below the clouds. Therefore, the size distributions parameterized as spectral bin microphysics are needed to explicitly study the effects of atmospheric aerosol concentration on cloud development, rainfall production, and rainfall rates for convective clouds. Recently, a detailed spectral--bin microphysical scheme was implemented into the Goddard Cumulus Ensemble (GCE) model. The formulation for the explicit spectral-bin microphysical processes is based on solving stochastic kinetic equations for the size distribution functions of water droplets (i.e., cloud droplets and raindrops), and several types of ice particles [i.e., pristine ice crystals (columnar and plate-like), snow (dendrites and aggregates), graupel and frozen drops/hail]. Each type is described by a special size distribution function containing many categories (i.e., 33 bins). Atmospheric aerosols are also described using number density size-distribution functions.

  9. PROCESSES FOR SEPARATING AND RECOVERING CONSTITUENTS OF NEUTRON IRRADIATED URANIUM

    DOEpatents

    Connick, R.E.; Gofman, J.W.; Pimentel, G.C.

    1959-11-10

    Processes are described for preparing plutonium, particularly processes of separating plutonium from uranium and fission products in neutron-irradiated uraniumcontaining matter. Specifically, plutonium solutions containing uranium, fission products and other impurities are contacted with reducing agents such as sulfur dioxide, uranous ion, hydroxyl ammonium chloride, hydrogen peroxide, and ferrous ion whereby the plutoninm is reduced to its fluoride-insoluble state. The reduced plutonium is then carried out of solution by precipitating niobic oxide therein. Uranium and certain fission products remain behind in the solution. Certain other fission products precipitate along with the plutonium. Subsequently, the plutonium and fission product precipitates are redissolved, and the solution is oxidized with oxidizing agents such as chlorine, peroxydisulfate ion in the presence of silver ion, permanganate ion, dichromate ion, ceric ion, and a bromate ion, whereby plutonium is oxidized to the fluoride-soluble state. The oxidized solution is once again treated with niobic oxide, thus precipitating the contamirant fission products along with the niobic oxide while the oxidized plutonium remains in solution. Plutonium is then recovered from the decontaminated solution.

  10. Precipitate hydrolysis process for the removal of organic compounds from nuclear waste slurries

    DOEpatents

    Doherty, J.P.; Marek, J.C.

    1987-02-25

    A process for removing organic compounds from a nuclear waste slurry comprising reacting a mixture of radioactive waste precipitate slurry and an acid in the presence of a catalytically effective amount of a copper(II) catalyst whereby the organic compounds in the precipitate slurry are hydrolyzed to form volatile organic compounds which are separated from the reacting mixture. The resulting waste slurry, containing less than 10 percent of the original organic compounds, is subsequently blended with high level radioactive sludge land transferred to a vitrification facility for processing into borosilicate glass for long-term storage. 2 figs., 3 tabs.

  11. Precipitate hydrolysis process for the removal of organic compounds from nuclear waste slurries

    DOEpatents

    Doherty, Joseph P.; Marek, James C.

    1989-01-01

    A process for removing organic compounds from a nuclear waste slurry comprising reacting a mixture of radioactive waste precipitate slurry and an acid in the presence of a catalytically effective amount of a copper (II) catalyst whereby the organic compounds in the precipitate slurry are hydrolyzed to form volatile organic compounds which are separated from the reacting mixture. The resulting waste slurry, containing less than 10 percent of the orginal organic compounds, is subsequently blended with high level radioactive sludge and transferred to a virtrification facility for processing into borosilicate glass for long-term storage.

  12. New separation and purification processes and equipment

    SciTech Connect

    Malyusov, V.A.

    1987-09-01

    The authors consider research carried out into new methods and processes for purifying and separating material and on modifying existing separation processes. Areas discussed include cycled mass transfer processes, three-phase liquid extraction, fines removal from suspended submicron particles, adsorption with variable pressure, crystallization from flowing liquid films, extraction by dense gases, combined processes, the application of electric fields, addition of surfactants and new hydrodynamic regimes. The authors discuss membrane distillation as the membrane separation technique in which the driving force is a temperature gradient. Membrane distillation incurs small energy costs and its applications include the production of boiler water, the desalination of sea water using the waste heat from diesel boilers, power stations, or solar energy, the concentration of product solutions, and the combination of concentration and production of desalinated water for industrial use.

  13. Process for separating nitrogen from methane using microchannel process technology

    DOEpatents

    Tonkovich, Anna Lee; Qiu, Dongming; Dritz, Terence Andrew; Neagle, Paul; Litt, Robert Dwayne; Arora, Ravi; Lamont, Michael Jay; Pagnotto, Kristina M.

    2007-07-31

    The disclosed invention relates to a process for separating methane or nitrogen from a fluid mixture comprising methane and nitrogen, the process comprising: (A) flowing the fluid mixture into a microchannel separator, the microchannel separator comprising a plurality of process microchannels containing a sorption medium, the fluid mixture being maintained in the microchannel separator until at least part of the methane or nitrogen is sorbed by the sorption medium, and removing non-sorbed parts of the fluid mixture from the microchannel separator; and (B) desorbing the methane or nitrogen from the sorption medium and removing the desorbed methane or nitrogen from the microchannel separator. The process is suitable for upgrading methane from coal mines, landfills, and other sub-quality sources.

  14. Optimization of the rapping process of an intermittent electrostatic precipitator

    NASA Astrophysics Data System (ADS)

    Miloua, F.; Tilmatine, A.; Gouri, R.; Kadous, N.; Dascalescu, L.

    2008-01-01

    Intermittent operation mode is specific to electrostatic precipitators (ESP) used in workshops where the polluting product is produced in a discontinuous way. The rapping system is necessary in order to ensure a continuous and effective operation of a dry electrostatic precipitator, but causes at the same time, a problem of re-entrainment of dust and thus the degradation of filtration efficiency. The objective of this paper is to propose a procedure based on the methodology of experimental designs (Tagushi's Methodology) aiming at optimizing the rapping process; it consists to determine optimal values of rapping, i.e. the moment, the position and the force of rapping. Several “one-factor-at-a-time" experimental designs followed by a Full Factorial design, made it possible to model the process and to analyze interactions between the factors. The experiments were carried out on a laboratory experimental device which simulates an industrial precipitator with intermittent operation.

  15. Diffusion and precipitation processes in iron-based silica gardens.

    PubMed

    Glaab, F; Rieder, J; García-Ruiz, J M; Kunz, W; Kellermeier, M

    2016-09-28

    Silica gardens are tubular structures that form along the interface of multivalent metal salts and alkaline solutions of sodium silicate, driven by a complex interplay of osmotic and buoyant forces together with chemical reaction. They display peculiar plant-like morphologies and thus can be considered as one of the few examples for the spontaneous biomimetic self-ordering of purely inorganic materials. Recently, we could show that silica gardens moreover are highly dynamic systems that remain far from equilibrium for considerable periods of time long after macroscopic growth is completed. Due to initial compartmentalisation, drastic concentration gradients were found to exist across the tube walls, which give rise to noticeable electrochemical potential differences and decay only slowly in a series of coupled diffusion and precipitation processes. In the present work, we extend these studies and investigate the effect of the nature of the used metal cations on the dynamic behaviour of the system. To that end, we have grown single macroscopic silica garden tubes by controlled addition of sodium silicate sol to pellets of iron(ii) and iron(iii) chloride. In the following, the concentrations of ionic species were measured as a function of time on both sides of the formed membranes, while electrochemical potentials and pH were monitored online by immersing the corresponding sensors into the two separated solution reservoirs. At the end of the experiments, the solid tube material was furthermore characterised with respect to composition and microstructure by a combination of ex situ techniques. The collected data are compared to the previously reported case of cobalt-based silica gardens and used to shed light on ion diffusion through the inorganic membranes as well as progressive mineralisation at both surfaces of the tube walls. Our results reveal important differences in the dynamics of the three studied systems, which can be explained based on the acidity of the

  16. Diffusion and precipitation processes in iron-based silica gardens.

    PubMed

    Glaab, F; Rieder, J; García-Ruiz, J M; Kunz, W; Kellermeier, M

    2016-09-28

    Silica gardens are tubular structures that form along the interface of multivalent metal salts and alkaline solutions of sodium silicate, driven by a complex interplay of osmotic and buoyant forces together with chemical reaction. They display peculiar plant-like morphologies and thus can be considered as one of the few examples for the spontaneous biomimetic self-ordering of purely inorganic materials. Recently, we could show that silica gardens moreover are highly dynamic systems that remain far from equilibrium for considerable periods of time long after macroscopic growth is completed. Due to initial compartmentalisation, drastic concentration gradients were found to exist across the tube walls, which give rise to noticeable electrochemical potential differences and decay only slowly in a series of coupled diffusion and precipitation processes. In the present work, we extend these studies and investigate the effect of the nature of the used metal cations on the dynamic behaviour of the system. To that end, we have grown single macroscopic silica garden tubes by controlled addition of sodium silicate sol to pellets of iron(ii) and iron(iii) chloride. In the following, the concentrations of ionic species were measured as a function of time on both sides of the formed membranes, while electrochemical potentials and pH were monitored online by immersing the corresponding sensors into the two separated solution reservoirs. At the end of the experiments, the solid tube material was furthermore characterised with respect to composition and microstructure by a combination of ex situ techniques. The collected data are compared to the previously reported case of cobalt-based silica gardens and used to shed light on ion diffusion through the inorganic membranes as well as progressive mineralisation at both surfaces of the tube walls. Our results reveal important differences in the dynamics of the three studied systems, which can be explained based on the acidity of the

  17. Thermodynamics for separation-process technology

    SciTech Connect

    Prausnitz, J.M.

    1995-10-01

    When contemplating or designing a separation process, every chemical engineer at once recognizes the thermodynamic boundary conditions that must be satisfied: when a mixture is continuously processed to yield at least partially purified products, energy and mass must be conserved and work must be done. In his daily tasks, a chemical engineer uses thermodynamic concepts as tacit, almost subconscious, knowledge. Thus, qualitative thermodynamics significantly informs process conception at its most fundamental level. However, quantitative design requires detailed knowledge of thermodynamic relations and physical chemistry. Most process engineers, concerned with flow sheets and economics, cannot easily command that detailed knowledge and therefore it is advantageous for them to maintain close contact with those specialists who do. Quantitative chemical thermodynamics provides an opportunity to evaluate possible separation processes not only because it may give support to the process engineer`s bold imagination but also because, when coupled with molecular models, it can significantly reduce the experimental effort required to determine an optimum choice of process alternatives. Six examples are presented to indicate the application of thermodynamics for conventional and possible future separation processes.

  18. PROCESS OF SEPARATING PLUTONIUM VALUES BY ELECTRODEPOSITION

    DOEpatents

    Whal, A.C.

    1958-04-15

    A process is described of separating plutonium values from an aqueous solution by electrodeposition. The process consists of subjecting an aqueous 0.1 to 1.0 N nitric acid solution containing plutonium ions to electrolysis between inert metallic electrodes. A current density of one milliampere io one ampere per square centimeter of cathode surface and a temperature between 10 and 60 d C are maintained. Plutonium is electrodeposited on the cathode surface and recovered.

  19. Separation process using pervaporation and dephlegmation

    DOEpatents

    Vane, Leland M.; Mairal, Anurag P.; Ng, Alvin; Alvarez, Franklin R.; Baker, Richard W.

    2004-06-29

    A process for treating liquids containing organic compounds and water. The process includes a pervaporation step in conjunction with a dephlegmation step to treat at least a portion of the permeate vapor from the pervaporation step. The process yields a membrane residue stream, a stream enriched in the more volatile component (usually the organic) as the overhead stream from the dephlegmator and a condensate stream enriched in the less volatile component (usually the water) as a bottoms stream from the dephlegmator. Any of these may be the principal product of the process. The membrane separation step may also be performed in the vapor phase, or by membrane distillation.

  20. Actinide Lanthanide Separation Process – ALSEP

    SciTech Connect

    Gelis, Artem V.; Lumetta, Gregg J.

    2014-01-29

    Separation of the minor actinides (Am, Cm) from the lanthanides at an industrial scale remains a significant technical challenge for closing the nuclear fuel cycle. To increase the safety of used nuclear fuel (UNF) reprocessing, as well as reduce associated costs, a novel solvent extraction process has been developed. The process allows for partitioning minor actinides, lanthanides and fission products following uranium/plutonium/neptunium removal; minimizing the number of separation steps, flowsheets, chemical consumption, and waste. This new process, Actinide Lanthanide SEParation (ALSEP), uses an organic solvent consisting of a neutral diglycolamide extractant, either N,N,N',N'-tetra(2 ethylhexyl)diglycolamide (T2EHDGA) or N,N,N',N'-tetraoctyldiglycolamide (TODGA), and an acidic extractant 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (HEH[EHP]), dissolved in an aliphatic diluent (e.g. n-dodecane). The An/Ln co-extraction is conducted from moderate-to-strong nitric acid, while the selective stripping of the minor actinides from the lanthanides is carried out using a polyaminocarboxylic acid/citrate buffered solution at pH anywhere between 3 and 4.5. The extraction and separation of the actinides from the fission products is very effective in a wide range of HNO3 concentrations and the minimum separation factors for lanthanide/Am exceed 30 for Nd/Am, reaching > 60 for Eu/Am under some conditions. The experimental results presented here demonstrate the great potential for a combined system, consisting of a neutral extractant such as T2EHDGA or TODGA, and an acidic extractant such as HEH[EHP], for separating the minor actinides from the lanthanides.

  1. UPGRADING NATURAL GAS VIA MEMBRANE SEPARATION PROCESSES

    SciTech Connect

    S.A.Stern; P.A. Rice; J. Hao

    2000-03-01

    The objective of the present study is to assess the potential usefulness of membrane separation processes for removing CO{sub 2} and H{sub 2}S from low-quality natural gas containing substantial amounts of both these ''acid'' gases, e.g., up to 40 mole-% CO{sub 2} and 10 mole-% H{sub 2}S. The membrane processes must be capable of upgrading the crude natural gas to pipeline specifications ({le} 2 mole-% CO{sub 2}, {le} 4 ppm H{sub 2}S). Moreover, these processes must also be economically competitive with the conventional separation techniques, such as gas absorption, utilized for this purpose by the gas industry.

  2. Modelling and dynamic simulation of struvite precipitation from source-separated urine.

    PubMed

    Schneider, Philip A; Wallace, James W; Tickle, Julian C

    2013-01-01

    A model of a mixed-mode nutrient recovery reactor is developed for a urine feed, incorporating complex solution thermodynamics, dynamic conservation relations and a power-law kinetic expression for crystal growth from seed crystals. Simulations at nominal operating conditions predict phosphorus recoveries greater than 99%, based on existing process kinetic parameters and operating conditions employed in previously published studies. The overall rate of nutrient recovery depends on the saturation index of the precipitating solid, the available surface area for mass transfer and the feed rate of the limiting constituent ion. Under the conditions considered, the nutrient feed rate appears to be the limiting factor for precipitation. Simulations demonstrate that diurnal feed flow variations of ±50% have a small effect on the rate of nutrient recovery. Overall, the study shows that valuable insights are gained in relation to process performance predictions, which should lead to more confident process design, operation and control.

  3. The Actinide-Lanthanide Separation Process

    SciTech Connect

    Lumetta, Gregg J.; Gelis, Artem V.; Carter, Jennifer C.; Niver, Cynthia M.; Smoot, Margaret R.

    2014-02-21

    The Actinide-Lanthanide SEParation (ALSEP) process is described. The process uses an extractant phase consisting of either N,N,N',N'-tetraoctyldiglycolamide (TODGA) or N,N,N',N'-tetra(2 ethylhexyl)diglycolamide (T2EHDGA) combined with 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (HEH[EHP]). The neutral TODGA or T2EHDGA serves to co-extract the trivalent actinide and lanthanide ions from nitric acid media. Switching the aqueous phase chemistry to a citrate buffered diethylenetriaminepentaacetic acid (DTPA) solution at pH 2.5 to 4 results in selective transfer of the actinides to the aqueous phase, thus resulting in separation of these two groups of elements.

  4. SEPARATION PROCESS USING COMPLEXING AND ADSORPTION

    DOEpatents

    Spedding, J.H.; Ayers, J.A.

    1958-06-01

    An adsorption process is described for separating plutonium from a solution of neutron-irradiated uranium containing ions of a compound of plutonium and other cations. The method consists of forming a chelate complex compound with plutoniunn ions in the solution by adding a derivative of 8- hydroxyquinoline, which derivative contains a sulfonic acid group, and adsorbing the remaining cations from the solution on a cation exchange resin, while the complexed plutonium remains in the solution.

  5. Foam flotation as a separation process

    NASA Technical Reports Server (NTRS)

    Currin, B. L.

    1986-01-01

    The basic principles of foam separation techniques are discussed. A review of the research concerning bubble-particle interaction and its role in the kinetics of the flotation process is given. Most of the research in this area deals with the use of theoretical models to predict the effects of bubble and particle sizes, of liquid flow, and of various forces on the aperture and retention of particles by bubbles. A discussion of fluid mechanical aspects of particle flotation is given.

  6. FLUORINE PROCESS FOR SEPARATION OF MATERIALS

    DOEpatents

    Seaborg, G.T.; Brown, H.S.

    1958-05-01

    A process is described for separating plutoniunn from neutron-irradiated uranium, which consists of reacting the irradiated uranium mass with HF to form the tetrafluorides of U, Pu, and Np, and then reacting this mixture of tetrafluorides with fiuorine at temperature between 140 and 315 d C. This causes volatile hexafluorides of U and Np to form while at the temperature employed the Pu tetrafluoride is unaffected and remains as a residue.

  7. Separation of spatial and temporal structure of auroral particle precipitation (Invited)

    NASA Astrophysics Data System (ADS)

    Boudouridis, A.; Spence, H.

    2013-12-01

    Knowledge of the dominant temporal and spatial scales of auroral features is instrumental in understanding the various mechanisms responsible for auroral particle precipitation. Single spacecraft data suffer from temporal/spatial ambiguity. In an effort to separate the temporal and spatial variations of the aurora, we use electron and ion precipitation data from two co-orbiting satellites, F6 and F8 of the Defense Meteorological Satellite Program (DMSP). The two spacecraft have almost identical polar orbits with a small difference in period. As a result the time difference between the two measurements varies with time. We use two statistical tools in order to determine the most probable lifetimes and spatial dimensions of the prevalent auroral features, Cross Correlation Analysis (CCA) and Cross Spectral Analysis (CSA). The CCA is applied to the magnetic latitude series of electron and ion, integral number and energy fluxes measured by the two DMSP spacecraft. As one spacecraft overtakes the other, the variable time lag between the two measurements results in different cross correlation of the two series. We explore the dependence of this variation on the time lag between the satellites. We find that the electron precipitation exhibits a decreasing correlation between the two spacecraft with increasing time lag, whereas there is only a small similar effect for the ion precipitation data. For the CSA we compute the so-called coherence function as a function of frequency (or inverse wavelength), and hence size of the auroral features. The coherence function is a measure of the stability of auroral features of different sizes. We investigate its variation as a function of the time separation between the two DMSP spacecraft measurements. We show that the coherence function of both electrons and ions remains high for up to 1.5 min spacecraft separations for all features larger than about 100 km in width. For smaller features the coherence is lower even for time lags of

  8. ION EXCHANGE ADSORPTION PROCESS FOR PLUTONIUM SEPARATION

    DOEpatents

    Boyd, G.E.; Russell, E.R.; Taylor, M.D.

    1961-07-11

    Ion exchange processes for the separation of plutonium from fission products are described. In accordance with these processes an aqueous solution containing plutonium and fission products is contacted with a cation exchange resin under conditions favoring adsorption of plutonium and fission products on the resin. A portion of the fission product is then eluted with a solution containing 0.05 to 1% by weight of a carboxylic acid. Plutonium is next eluted with a solution containing 2 to 8 per cent by weight of the same carboxylic acid, and the remaining fission products on the resin are eluted with an aqueous solution containing over 10 per cent by weight of sodium bisulfate.

  9. Membrane Separation Processes at Low Temperatures

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde

    2002-01-01

    The primary focus of Kennedy Space Center's gas separation activities has been for carbon dioxide, nitrogen, and argon used in oxygen production technologies for Martian in-situ resource utilization (ISRU) projects. Recently, these studies were expanded to include oxygen for regenerative life support systems. Since commercial membrane systems have been developed for separation of carbon dioxide, nitrogen, and oxygen, initially the studies focused on these membrane systems, but at lower operating temperatures and pressures. Current investigations art examining immobilized liquids and solid sorbents that have the potential for higher selectivity and lower operating temperatures. The gas separation studies reported here use hollow fiber membranes to separate carbon dioxide, nitrogen, and argon in the temperature range from 230 to 300 K. Four commercial membrane materials were used to obtain data at low feed and permeate pressures. These data were used with a commercial solution-diffusion modeling tool to design a system to prepare a buffer gas from the byproduct of a process to capture Martian carbon dioxide. The system was designed to operate, at 230 K with a production rate 0.1 sLpm; Feed composition 30% CO2, 44% N2, and 26% Ar; Feed pressure 104 kPa (780); and Permeate pressure 1 kPa (6 torr); Product concentration 600 ppm CO2. This new system was compared with a similar system designed to operate at ambient temperatures (298 K). The systems described above, along with data, test apparatus, and models are presented.

  10. Process Control for Precipitation Prevention in Space Water Recovery Systems

    NASA Technical Reports Server (NTRS)

    Sargusingh, Miriam; Callahan, Michael R.; Muirhead, Dean

    2015-01-01

    The ability to recover and purify water through physiochemical processes is crucial for realizing long-term human space missions, including both planetary habitation and space travel. Because of their robust nature, rotary distillation systems have been actively pursued by NASA as one of the technologies for water recovery from wastewater primarily comprised of human urine. A specific area of interest is the prevention of the formation of solids that could clog fluid lines and damage rotating equipment. To mitigate the formation of solids, operational constraints are in place that limits such that the concentration of key precipitating ions in the wastewater brine are below the theoretical threshold. This control in effected by limiting the amount of water recovered such that the risk of reaching the precipitation threshold is within acceptable limits. The water recovery limit is based on an empirically derived worst case wastewater composition. During the batch process, water recovery is estimated by monitoring the throughput of the system. NASA Johnson Space Center is working on means of enhancing the process controls to increase water recovery. Options include more precise prediction of the precipitation threshold. To this end, JSC is developing a means of more accurately measuring the constituent of the brine and/or wastewater. Another means would be to more accurately monitor the throughput of the system. In spring of 2015, testing will be performed to test strategies for optimizing water recovery without increasing the risk of solids formation in the brine.

  11. The effect of small scale variablity in isotopic composition of precipitation on hydrograph separation results

    NASA Astrophysics Data System (ADS)

    Fischer, Benjamin; van Meerveld, Ilja; Seibert, Jan

    2016-04-01

    Understanding runoff processes is important for predictions of streamflow quantity and quality. The two-component isotope hydrograph separation (IHS) method is a valuable tool to study how catchments transform rainfall into runoff. IHS allows the stormflow hydrograph to be separated into rainfall (event water) and water that was stored in the catchment before the event (pre-event water). To be able to perform an IHS, water samples of baseflow (pre-event water) and stormflow are collected at the stream outlet. Rainfall is usually collected at one location by hand as an event total or sampled sequentially during the event. It is usually assumed that the spatial variability in rainfall and the isotopic composition of rainfall are negligible for small (<10km2) catchments. However, different studies have shown that precipitation can vary within short distances. Subsequently it remains unclear how the spatio-temproal variability of rainfall and the stable isotope composition of rainfall affect the results of an IHS. In this study, we investigated the effects of the spatio-temporal variability in the isotopic composition of rainfall across a small headwater catchment in Switzerland. Rainfall was measured at eight locations and three streams (catchment area of 0.15, 0.23, and 0.7 km2). The isotopic composition of rainfall and streamflow were sampled for 10 different rain events (P: 5 mm intervals, Q: 12 to 51 samples per events). This dataset was used to perform a two-component isotope hydrograph separation. The results show that for some events the spatial variability in total rainfall, mean and maximum rainfall intensity and stable isotope composition of rainfall was high. There was no relation between the stable isotope composition of rainfall and the rainfall sum, rainfall intensity or altitude. The spatial variability of the isotopic composition of rainfall was for 4 out of the 10 events as large as the temporal variability in the isotopic composition. Different

  12. Precipitation softening: a pretreatment process for seawater desalination.

    PubMed

    Ayoub, George M; Zayyat, Ramez M; Al-Hindi, Mahmoud

    2014-02-01

    Reduction of membrane fouling in reverse osmosis systems and elimination of scaling of heat transfer surfaces in thermal plants are a major challenge in the desalination of seawater. Precipitation softening has the potential of eliminating the major fouling and scaling species in seawater desalination plants, thus allowing thermal plants to operate at higher top brine temperatures and membrane plants to operate at a reduced risk of fouling, leading to lower desalinated water costs. This work evaluated the use of precipitation softening as a pretreatment step for seawater desalination. The effectiveness of the process in removing several scale-inducing materials such as calcium, magnesium, silica, and boron was investigated under variable conditions of temperature and pH. The treatment process was also applied to seawater spiked with other known fouling species such as iron and bacteria to determine the efficiency of removal. The results of this work show that precipitation softening at a pH of 11 leads to complete elimination of calcium, silica, and bacteria; to very high removal efficiencies of magnesium and iron (99.6 and 99.2 %, respectively); and to a reasonably good removal efficiency of boron (61 %). PMID:24151028

  13. Precipitation softening: a pretreatment process for seawater desalination.

    PubMed

    Ayoub, George M; Zayyat, Ramez M; Al-Hindi, Mahmoud

    2014-02-01

    Reduction of membrane fouling in reverse osmosis systems and elimination of scaling of heat transfer surfaces in thermal plants are a major challenge in the desalination of seawater. Precipitation softening has the potential of eliminating the major fouling and scaling species in seawater desalination plants, thus allowing thermal plants to operate at higher top brine temperatures and membrane plants to operate at a reduced risk of fouling, leading to lower desalinated water costs. This work evaluated the use of precipitation softening as a pretreatment step for seawater desalination. The effectiveness of the process in removing several scale-inducing materials such as calcium, magnesium, silica, and boron was investigated under variable conditions of temperature and pH. The treatment process was also applied to seawater spiked with other known fouling species such as iron and bacteria to determine the efficiency of removal. The results of this work show that precipitation softening at a pH of 11 leads to complete elimination of calcium, silica, and bacteria; to very high removal efficiencies of magnesium and iron (99.6 and 99.2 %, respectively); and to a reasonably good removal efficiency of boron (61 %).

  14. Indian summer monsoon precipitating clouds: role of microphysical process rates

    NASA Astrophysics Data System (ADS)

    Hazra, Anupam; Chaudhari, Hemantkumar S.; Pokhrel, Samir; Saha, Subodh K.

    2016-04-01

    The budget analysis of microphysical process rates based on Modern Era Retrospective-analysis for Research and Applications (MERRA) products are presented in the study. The relative importance of different microphysical process rates, which is crucial for GCMs, is investigated. The autoconversion and accretion processes are found to be vital for Indian Summer Monsoon (ISM). The map-to-map correlations are examined between observed precipitation and MERRA reanalysis. The pattern correlations connote the fidelity of the MERRA datasets used here. Results of other microphysical parameters (e.g. ice water content from CloudSat, high cloud fraction from CALIPSO and MODIS, latent heating from TRMM, cloud ice mixing ratio from MERRA) are presented in this study. The tropospheric temperature from reanalysis product of MERRA and NCEP are also analyzed. Furthermore, the linkages between cloud microphysics production rates and dynamics, which are important for North-South tropospheric temperature gradient for maintaining the ISM circulation, are also discussed. The study demonstrates the microphysical process rates, which are actually responsible for the cloud hydrometeors and precipitation formation on the monsoon intraseasonal oscillations timescale. Cloud to rain water auto-conversion and snow accretion rates are the dominant processes followed by the rain accretion. All these tendency terms replicates the similar spatial patterns as that of precipitation. The quantification of microphysical process rates and precipitation over different regions are shown here. The freezing rate is also imperative for the formation of cloud ice as revealed by the observation. Freezing rates at upper level and snow accretion at middle level may have effect on latent heating release. Further it can modulate the north-south temperature gradient which can influence the large-scale monsoon dynamics. The rain water evaporation is also considered as a key aspect for controlling the low level

  15. Liquid-Liquid Phase Separation in Supersaturated Lysozyme Solutions and Associated Precipitate Formation/Crystallization

    NASA Technical Reports Server (NTRS)

    Muschol, Martin; Rosenberger, Franz

    1997-01-01

    Using cloud point determinations, the phase boundaries (binodals) for metastable liquid-liquid (L-L) separation in supersaturated hen egg white lysozyme solutions with 3%, 5%, and 7% (wlv) NaCl at pH= 4.5 and protein concentrations c between 40 and 400 mg/ml were determined. The critical temperature for the binodal increased approximately linearly with salt concentration. The coexisting liquid phases both remained supersaturated but differed widely in protein concentration. No salt repartitioning was observed between the initial and the two separated liquid phases. After the L-L separation, due to the presence of the high protein concentration phase, crystallization occurred much more rapidly than in the initial solution. At high initial protein concentrations, a metastable gel phase formed at temperatures above the liquid binodal. Both crystal nucleation and gel formation were accelerated in samples that had been cycled through the binodal. Solutions in the gel and L-L regions yielded various types of precipitates. Based on theoretical considerations, previous observations with other proteins, and our experimental results with lysozyme, a generic phase diagram for globular proteins is put forth. A limited region in the (T,c) plane favorable for the growth of protein single crystals is delineated.

  16. Benzene/nitrous oxide flammability in the precipitate hydrolysis process

    SciTech Connect

    Jacobs, R A

    1989-09-18

    The HAN (hydroxylamine nitrate) process for destruction of nitrite in precipitate hydrolysis produces nitrous oxide (N2O) gas as one of the products. N2O can form flammable mixtures with benzene which is also present due to radiolysis and hydrolysis of tetraphenylborate. Extensive flame modeling and explosion testing was undertaken to define the minimum oxidant for combustion of N2O/benzene using both nitrogen and carbon dioxide as diluents. The attached memorandum interprets and documents the results of the studies.

  17. Unmasking the effect of a precipitation pulse on the biological processes composing Net Ecosystem Carbon Exchange

    NASA Astrophysics Data System (ADS)

    Lopez-Ballesteros, Ana; Sanchez-Cañete, Enrique P.; Serrano-Ortiz, Penelope; Oyonarte, Cecilio; Kowalski, Andrew S.; Perez-Priego, Oscar; Domingo, Francisco

    2015-04-01

    Drylands occupy 47.2% of the global terrestrial area and are key ecosystems that significantly determine the inter-annual variability of the global carbon balance. However, it is still necessary to delve into the functional behavior of arid and semiarid ecosystems due to the complexity of drivers and interactions between underpinning processes (whether biological or abiotic) that modulate net ecosystem CO2 exchange (NEE). In this context, water inputs are crucial to biological organisms survival in arid ecosystems and frequently arrive via rain events that are commonly stochastic and unpredictable (i.e. precipitation pulses) and strongly control arid land ecosystem structure and function. The eddy covariance technique can be used to investigate the effect of precipitation pulses on NEE, but provide limited understanding of what exactly happens after a rain event. The chief reasons are that, firstly, we cannot measure separately autotrophic and heterotrophic components, and secondly, the partitioning techniques widely utilized to separate Gross Primary Production and Total Ecosystem Respiration, do not work properly in these water-limited ecosystems, resulting in biased estimations of plant and soil processes. Consequently, it is essential to combine eddy covariance measurements with other techniques to disentangle the different biological processes composing NEE that are activated by a precipitation pulse. Accordingly, the main objectives of this work were: (i) to quantify the contribution of precipitation pulse events to annual NEE using the eddy covariance technique in a semiarid steppe located in Almería (Spain), and (ii) to simulate a realistic precipitation pulse in order to understand its effect on the ecosystem, soil and plant CO2 exchanges by using a transitory-state closed canopy chamber, soil respiration chambers and continuous monitoring CO2 sensors inserted in the subsoil. Preliminary results showed, as expected, a delay between soil and plant

  18. Separation processes during binary monotectic alloy production

    NASA Technical Reports Server (NTRS)

    Frazier, D. O.; Facemire, B. R.; Kaukler, W. F.; Witherow, W. K.; Fanning, U.

    1984-01-01

    Observation of microgravity solidification processes indicates that outside of sedimentation, at least two other important effects can separate the phases: critical-point wetting and spreading; and thermal migration of second-phase droplets due to interfacial tension gradients. It is difficult to study these surface tension effects while in a unit gravity field. In order to investigate the processes occurring over a temperature range, i.e., between a consolute point and the monotectic temperature, it is necessary to use a low-gravity environment. The MSFC drop tube (and tower), the ballistic trajectory KC-135 airplane, and the Space Shuttle are ideal facilities to aid formation and testing of hypotheses. Much of the early work in this area focuses on transparent materials so that process dynamics may be studied by optical techniques such as photography for viewing macro-processes; holography for studying diffusional growth; spinodal decomposition and coalescence; ellipsometry for surface wetting and spreading effects; and interferometry and spectroscopy for small-scale spatial resolution of concentration profiles.

  19. Plutonium Chemistry in the UREX+ Separation Processes

    SciTech Connect

    ALena Paulenova; George F. Vandegrift, III; Kenneth R. Czerwinski

    2009-10-01

    The project "Plutonium Chemistry in the UREX+ Separation Processes” is led by Dr. Alena Paulenova of Oregon State University under collaboration with Dr. George Vandegrift of ANL and Dr. Ken Czerwinski of the University of Nevada at Las Vegas. The objective of the project is to examine the chemical speciation of plutonium in UREX+ (uranium/tributylphosphate) extraction processes for advanced fuel technology. Researchers will analyze the change in speciation using existing thermodynamics and kinetic computer codes to examine the speciation of plutonium in aqueous and organic phases. They will examine the different oxidation states of plutonium to find the relative distribution between the aqueous and organic phases under various conditions such as different concentrations of nitric acid, total nitrates, or actinide ions. They will also utilize techniques such as X-ray absorbance spectroscopy and small-angle neutron scattering for determining plutonium and uranium speciation in all separation stages. The project started in April 2005 and is scheduled for completion in March 2008.

  20. Process, including membrane separation, for separating hydrogen from hydrocarbons

    DOEpatents

    Baker, Richard W.; Lokhandwala, Kaaeid A.; He, Zhenjie; Pinnau, Ingo

    2001-01-01

    Processes for providing improved methane removal and hydrogen reuse in reactors, particularly in refineries and petrochemical plants. The improved methane removal is achieved by selective purging, by passing gases in the reactor recycle loop across membranes selective in favor of methane over hydrogen, and capable of exhibiting a methane/hydrogen selectivity of at least about 2.5 under the process conditions.

  1. Separation of isotopes by cyclical processes

    DOEpatents

    Hamrin, Jr., Charles E.; Weaver, Kenny

    1976-11-02

    Various isotopes of hydrogen are separated by a cyclic sorption process in which a gas stream containing the isotopes is periodically passed through a high pressure column containing a palladium sorbent. A portion of the product from the high pressure column is passed through a second column at lower pressure to act as a purge. Before the sorbent in the high pressure column becomes saturated, the sequence is reversed with the stream flowing through the former low-pressure column now at high pressure, and a portion of the product purging the former high pressure column now at low pressure. The sequence is continued in cyclic manner with the product being enriched in a particular isotope.

  2. Evaluation of Co-precipitation Processes for the Synthesis of Mixed-Oxide Fuel Feedstock Materials

    SciTech Connect

    Collins, Emory D; Voit, Stewart L; Vedder, Raymond James

    2011-06-01

    processes include (1) feed solution concentration adjustment, (2) precipitant concentration and addition methods, (3) pH, temperature, mixing method and time, (4) valence adjustment, (5) solid precipitate separation from the filtrate 'mother liquor,' generally by means of centrifugation or filtration, and (6) temperatures and times for drying, calcination, and reduction of the MOX product powder. Also a recovery step is necessary because of low, but finite solubility of the U/TRU metals in the mother liquor. The recovery step usually involves destruction of the residual precipitant and disposal of by-product wastes. Direct denitrations of U/TRU require fewer steps, but must utilize various methods to enable production of MOX with product characteristics that are acceptable for recycle fuel fabrication. The three co-precipitation processes considered for evaluation are (1) the ammonia co-precipitation process being developed in Russia, (2) the oxalate co-precipitation process, being developed in France, and (3) the ammonium-uranyl-plutonyl-carbonate (AUPuC) process being developed in Germany. Two direct denitration processes are presented for comparison: (1) the 'Microwave Heating (MH)' automated multi-batch process developed in Japan and (2) the 'Modified Direct Denitration (MDD)' continuous process being developed in the USA. Brief comparative descriptions of the U/TRU co-conversion processes are described. More complete details are provided in the references.

  3. [Network analysis of ethanol precipitation process for Schisandrae chinensis fructus].

    PubMed

    Zhong, Yi; Zhu, Jie-Qiang; Fan, Xiao-Hui; Kang, Li-Yuan; Li, Zheng

    2014-09-01

    A set of central composite design experiments were designed by using four factors which were ethanol amount, ethanol concentration, refrigeration temperature and refrigeration time. The relation between these factors with the target variables of the retention rate of schizandrol A, the soluble solids content, the removal rate of fructose and the removal rate of glucose were analyzed with Bayesian networks, and ethanol amount and ethanol concentration were found as the critical process parameters. Then a network model was built with 2 inputs and 4 outputs using back propagation artificial neural networks which was optimized by genetic algorithms. The R2 and MSE from the training set were 0.983 8 and 0.001 1. The R2 and MSE from the test set were 0.975 9 and 0.001 8. The results showed that network analysis method could be used for modeling of Schisandrae Chinensis Fructus ethanol precipitation process and identify critical operating parameters. PMID:25522613

  4. Stochastic investigation of precipitation process for climatic variability identification

    NASA Astrophysics Data System (ADS)

    Sotiriadou, Alexia; Petsiou, Amalia; Feloni, Elisavet; Kastis, Paris; Iliopoulou, Theano; Markonis, Yannis; Tyralis, Hristos; Dimitriadis, Panayiotis; Koutsoyiannis, Demetris

    2016-04-01

    The precipitation process is important not only to hydrometeorology but also to renewable energy resources management. We use a dataset consisting of daily and hourly records around the globe to identify statistical variability with emphasis on the last period. Specifically, we investigate the occurrence of mean, maximum and minimum values and we estimate statistical properties such as marginal probability distribution function and the type of decay of the climacogram (i.e., mean process variance vs. scale). Acknowledgement: This research is conducted within the frame of the undergraduate course "Stochastic Methods in Water Resources" of the National Technical University of Athens (NTUA). The School of Civil Engineering of NTUA provided moral support for the participation of the students in the Assembly.

  5. Experimental investigation of Mars meandering rivers: Chemical precipitation process

    NASA Astrophysics Data System (ADS)

    Kim, W.; Lim, Y.; Cleveland, J.; Reid, E.; Jew, C.

    2014-12-01

    On Earth, meandering streams occur where the banks are resistant to erosion, which enhances narrow and deep channels. Often this is because the stream banks are held firm by vegetation. The ancient, highly sinuous channels with cutoffs found on Mars are enigmatic because vegetation played no role in providing bank cohesion and enhancing fine sediment deposition. Possible causes of the meandering therefore include ice under permafrost conditions and chemical processes. We conducted carbonate flume experiments to investigate possible mechanisms creating meandering channels other than vegetation. The experiment includes a tank that dissolves limestone by adding CO2 gas and produces artificial spring water, peristaltic pumps to drive water through the system, a heater to control the temperature of the spring water, and a flume where carbonate sediment deposits. Spring water containing dissolved calcium and carbonate ions moves through a heater to increase temperature, and then into the flume. The flume surface is open to the air to allow CO2 degassing, decrease temperature, and increase pH, which promotes carbonate precipitation. A preliminary experiment was done and successfully created a meander pattern that evolved over a 3-day experiment. The experiment showed lateral migration of the bend and avulsion of the stream, similar to a natural meander. The lateral variation in flow speed increased the local residence time of water, thus increasing the degassing of CO2 on the two sides of the flow and promoting more precipitation. This enhanced precipitation on the sides provided a mechanism to build levees along the channel and created a stream confined in a narrow path. This mechanism also potentially applies to Earthly single thread and/or meandering rivers developed and recorded before vegetation appeared on Earth's surface.

  6. IPHEx 2014: Observations of Orographic Precipitation Processes in the Southern Appalachians

    NASA Astrophysics Data System (ADS)

    Barros, A. P.; Petersen, W. A.; Lang, T. J.; Wilson, A. M.; Duan, Y.; Nesbitt, S. W.; Cifelli, R.; Schwaller, M.; Wolff, D. B.; Miller, D. K.; Gourley, J. J.; Petters, M.

    2014-12-01

    The focus of the Integrated Precipitation and Hydrology Experiment (IPHEx) in the Southern Appalachians and including the Piedmont and Coastal Plain regions of North Carolina was to characterize warm season orographic precipitation regimes, and to investigate the relationship between precipitation regimes and hydrologic processes in regions of complex terrain. IPHEX consisted of two phases: 1) an extended observing period (EOP) from October 2013 through October 2014 including a science-grade high elevation raingauge network, in addition to the fixed regional observing system; a disdrometer network consisting of twenty separate clusters; three mobile profiling facilities including MicroRain Radars, microwave radiometers, radiosondes, and microphysics characterization instruments; and 2) an intense observing period (IOP) from May-July of 2014 post GPM launch focusing on 4D mapping of precipitation structure during which NASA's NPOL S-band scanning dual-polarization radar, the dual-frequency Ka-Ku, dual polarimetric, Doppler radar (D3R), four additional MRRs, and the NOAA NOXP radar were deployed along with the long-term fixed instrumentation. During the IOP, high altitude and "in the column" measurements were conducted using the NASA ER-2 and the UND Citation aircraft. By taking place after the launch of the GPM satellite, IPHEx provided the first opportunity for coordinated observations among all platforms. Here, we present a first synthesis of ground-based observations of precipitation processes and science findings from IPHEx, including a 4D physically-based integration of multisensor observations incorporating DPR Level 1 products in the inner mountain region that captures the complex vertical structure of microphysical processes modulated by orography, and a first interrogation of GMI and DPR Level 2 products in the IPHEX domain.

  7. Technical bases for precipitate hydrolysis process operating parameters

    SciTech Connect

    Bannochie, C.J.

    1992-10-05

    This report provides the experimental data and rationale in support of the operating parameters for precipitate hydrolysis specified in WSRC-RP-92737. The report is divided into two sections, the first dealing with lab-scale precipitate hydrolysis experimentation while the second part addresses large-scale runs conducted to demonstrate the revised operating parameters in the Precipitate Hydrolysis Experimental Facility (PHEF).

  8. Separation of aromatic precipitates from simulated high level radioactive waste by hydrolysis, evaporation and liquid-liquid extraction

    SciTech Connect

    Young, S.R.; Shah, H.B.; Carter, J.T.

    1991-01-01

    The Defense Waste Processing Facility (DWPF) at the SRS will be the United States' first facility to process High Level radioactive Waste (HLW) into a borosilicate glass matrix. The removal of aromatic precipitates by hydrolysis, evaporation and liquid-liquid extraction will be a key step in the processing of the HLW. This step, titled the Precipitate Hydrolysis Process, has been demonstrated by the Savannah River Laboratory with the Precipitate Hydrolysis Experimental Facility (PHEF). The mission of the PHEF is to demonstrate processing of simulated high level radioactive waste which contains tetraphenylborate precipitates and nitrite. Reduction of nitrite by hydroxylamine nitrate and hydrolysis of the tetraphenylborate by formic acid is discussed. Gaseous production, which is primarily benzene, nitrous oxide and carbon dioxide, has been quantified. Production of high-boiling organic compounds and the accumulation of these organic compounds within the process are addressed.

  9. Separation of aromatic precipitates from simulated high level radioactive waste by hydrolysis, evaporation and liquid-liquid extraction

    SciTech Connect

    Young, S.R.; Shah, H.B.; Carter, J.T.

    1991-12-31

    The Defense Waste Processing Facility (DWPF) at the SRS will be the United States` first facility to process High Level radioactive Waste (HLW) into a borosilicate glass matrix. The removal of aromatic precipitates by hydrolysis, evaporation and liquid-liquid extraction will be a key step in the processing of the HLW. This step, titled the Precipitate Hydrolysis Process, has been demonstrated by the Savannah River Laboratory with the Precipitate Hydrolysis Experimental Facility (PHEF). The mission of the PHEF is to demonstrate processing of simulated high level radioactive waste which contains tetraphenylborate precipitates and nitrite. Reduction of nitrite by hydroxylamine nitrate and hydrolysis of the tetraphenylborate by formic acid is discussed. Gaseous production, which is primarily benzene, nitrous oxide and carbon dioxide, has been quantified. Production of high-boiling organic compounds and the accumulation of these organic compounds within the process are addressed.

  10. The use of stream flow routing for direct channel precipitation with isotopically-based hydrograph separations: the role of new water in stormflow generation

    NASA Astrophysics Data System (ADS)

    Renshaw, Carl E.; Feng, Xiahong; Sinclair, Kelsey J.; Dums, Raymond H.

    2003-03-01

    Understanding the pathways by which event water contributes to stream stormflow provides insight into stormflow generation mechanisms. We analyze the impact of storm size on the relative contribution of event water to stormflow by using natural variations in the oxygen isotopic composition of precipitation and stream water to separate multiple stormflow hydrographs from a single fourth-order, 1212 ha catchment. We extend previous isotope-based hydrograph separations by independently accounting for the contribution of event water via direct channel precipitation to the stream hydrograph. The direct channel precipitation contribution is determined using a numerical model of stream flow routing though the catchment, taking precipitation and digital elevation data as input variables. For the range of storm sizes sampled, having recurrence intervals ranging from less than a week to ˜4 months, essentially all the event water in stream stormflow can be attributed to direct channel precipitation. Event water not directly falling on the stream channel indirectly contributes to stormflow by increasing the subsurface discharge of pre-event water to the stream. Neither the hydrograph separation data, field observations during the precipitation events, nor experimental observations of flow in a large-scale natural soil column extracted from the watershed are consistent with macropore flow or groundwater ridging as the primary mechanism responsible for increasing subsurface discharge. Results from a series of artificial rain experiments using the unsaturated natural soil column are consistent with a preferential kinematic flow model and indicate that the discharge of pre-event water to the stream during a storm event may be controlled by kinematic flow processes within the watershed soils.

  11. Actinide and lanthanide separation process (ALSEP)

    SciTech Connect

    Guelis, Artem V.

    2013-01-15

    The process of the invention is the separation of minor actinides from lanthanides in a fluid mixture comprising, fission products, lanthanides, minor actinides, rare earth elements, nitric acid and water by addition of an organic chelating aid to the fluid; extracting the fluid with a solvent comprising a first extractant, a second extractant and an organic diluent to form an organic extractant stream and an aqueous raffinate. Scrubbing the organic stream with a dicarboxylic acid and a chelating agent to form a scrubber discharge. The scrubber discharge is stripped with a simple buffering agent and a second chelating agent in the pH range of 2.5 to 6.1 to produce actinide and lanthanide streams and spent organic diluents. The first extractant is selected from bis(2-ethylhexyl)hydrogen phosphate (HDEHP) and mono(2-ethylhexyl)2-ethylhexyl phosphonate (HEH(EHP)) and the second extractant is selected from N,N,N,N-tetra-2-ethylhexyl diglycol amide (TEHDGA) and N,N,N',N'-tetraoctyl-3-oxapentanediamide (TODGA).

  12. Integration of advanced nuclear materials separation processes

    SciTech Connect

    Jarvinen, G.D.; Worl, L.A.; Padilla, D.D.; Berg, J.M.; Neu, M.P.; Reilly, S.D.; Buelow, S.

    1998-12-31

    This is the final report of a two-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). This project has examined the fundamental chemistry of plutonium that affects the integration of hydrothermal technology into nuclear materials processing operations. Chemical reactions in high temperature water allow new avenues for waste treatment and radionuclide separation.Successful implementation of hydrothermal technology offers the potential to effective treat many types of radioactive waste, reduce the storage hazards and disposal costs, and minimize the generation of secondary waste streams. The focus has been on the chemistry of plutonium(VI) in solution with carbonate since these are expected to be important species in the effluent from hydrothermal oxidation of Pu-containing organic wastes. The authors investigated the structure, solubility, and stability of the key plutonium complexes. Installation and testing of flow and batch hydrothermal reactors in the Plutonium Facility was accomplished. Preliminary testing with Pu-contaminated organic solutions gave effluent solutions that readily met discard requirements. A new effort in FY 1998 will build on these promising initial results.

  13. Segregation, precipitation, and α -α' phase separation in Fe-Cr alloys

    NASA Astrophysics Data System (ADS)

    Kuronen, A.; Granroth, S.; Heinonen, M. H.; Perälä, R. E.; Kilpi, T.; Laukkanen, P.; Lâng, J.; Dahl, J.; Punkkinen, M. P. J.; Kokko, K.; Ropo, M.; Johansson, B.; Vitos, L.

    2015-12-01

    Iron-chromium alloys, the base components of various stainless steel grades, have numerous technologically and scientifically interesting properties. However, these features are not yet sufficiently understood to allow their full exploitation in technological applications. In this work, we investigate segregation, precipitation, and phase separation in Fe-Cr systems analyzing the physical mechanisms behind the observed phenomena. To get a comprehensive picture of Fe-Cr alloys as a function of composition, temperature, and time the present investigation combines Monte Carlo simulations using semiempirical interatomic potential, first-principles total energy calculations, and experimental spectroscopy. In order to obtain a general picture of the relation of the atomic interactions and properties of Fe-Cr alloys in bulk, surface, and interface regions several complementary methods have to be used. Using the exact muffin-tin orbitals method with the coherent potential approximation (CPA-EMTO) the effective chemical potential as a function of Cr content (0-15 at. % Cr) is calculated for a surface, second atomic layer, and bulk. At ˜10 at. % Cr in the alloy the reversal of the driving force of a Cr atom to occupy either bulk or surface sites is obtained. The Cr-containing surfaces are expected when the Cr content exceeds ˜10 at. %. The second atomic layer forms about a 0.3 eV barrier for the migration of Cr atoms between the bulk and surface atomic layer. To get information on Fe-Cr in larger scales we use semiempirical methods. However, for Cr concentration regions less than 10 at. %, the ab initio (CPA-EMTO) result of the important role of the second atomic layer to the surface is not reproducible from the large-scale Monte Carlo molecular dynamics (MCMD) simulation. On the other hand, for the nominal concentration of Cr larger than 10 at. % the MCMD simulations show the precipitation of Cr into isolated pockets in bulk Fe-Cr and the existence of the upper limit of

  14. Processing of tetraphenylborate precipitates in the Savannah River Site Defense Waste Processing Facility

    SciTech Connect

    Eibling, R.E.

    1990-12-31

    The Savannah River Site has generated 77 million gallons of high level radioactive waste since the early 1950`s. By 1987, evaporation had reduced the concentration of the waste inventory to 35 million gallons. Currently, the wastes reside in large underground tanks as a soluble fraction stored, crystallized salts, and an insoluble fraction, sludge, which consists of hydrated transition metal oxides. The bulk of the radionuclides, 67 percent, are in the sludge while the crystallized salts and supernate are composed of the nitrates, nitrites, sulfates and hydroxides of sodium, potassium, and cesium. The principal radionuclide in the soluble waste is {sup 137}Cs with traces of {sup 90}Sr. The transformation of the high level wastes into a borosilicate glass suitable for permanent disposal is the goal of the Defense Waste Processing Facility (DWPF). To minimize the volume of glass produced, the soluble fraction of the waste is treated with sodium tetraphenylborate and sodium titanate in the waste tanks to precipitate the radioactive cesium ion and absorb the radioactive strontium ion. The precipitate is washed in the waste tanks and is then pumped to the DWPF. The precipitate, as received, is incompatible with the vitrification process because of the high aromatic carbon content and requires further chemical treatment. Within the DWPF, the precipitate is processed in the Salt Processing Cell to remove the aromatic carbon as benzene. The precipitate hydrolysis process hydrolyzes the tetraphenylborate anion to produce borate anion and benzene. The benzene is removed by distillation, decontaminated and transferred out of the DWPF for disposal.

  15. Using Doppler spectra to separate hydrometeor populations and analyze ice precipitation in multilayered mixed-phase clouds

    SciTech Connect

    Rambukkange, Mahlon P.; Verlinde, J.; Eloranta, E. W.; Flynn, Connor J.; Clothiaux, Eugene E.

    2011-01-31

    Multimodality of cloud radar Doppler spectra is used to partition cloud particle phases and to separate distinct ice populations in the radar sample volume, thereby facilitating analysis of individual ice showers in multilayered mixed-phase clouds. A 35-GHz cloud radar located at Barrow, Alaska, during the Mixed-Phase Arctic Cloud Experiment collected the Doppler spectra. Data from a pair of collocated depolarization lidars confirmed the presence of two liquid cloud layers reported in this study. Surprisingly, both of these cloud layers were embedded in ice precipitation yet maintained their liquid. Our spectral separation of the ice precipitation yielded two distinct ice populations: ice initiated within the two liquid cloud layers and ice precipitation formed in higher cloud layers. Comparisons of ice fall velocity versus radar reflectivity relationships derived for distinct showers reveal that a single relationship might not properly represent the ice showers during this period.

  16. PEROXIDE PROCESS FOR SEPARATION OF RADIOACTIVE MATERIALS

    DOEpatents

    Seaborg, G.T.; Perlman, I.

    1958-09-16

    reduced state, from hexavalent uranium. It consists in treating an aqueous solution containing such uranium and plutonium ions with sulfate ions in order to form a soluble uranium sulfate complex and then treating the solution with a soluble thorium compound and a soluble peroxide compound in order to ferm a thorium peroxide carrier precipitate which carries down with it the plutonium peroxide present. During this treatment the pH of the solution must be maintained between 2 and 3.

  17. Technical bases for precipitate hydrolysis process operating parameters. Revision 1

    SciTech Connect

    Bannochie, C.J.; Lambert, D.P.

    1992-11-09

    This report provides the experimental data and rationale in support of the operating parameters for tetraphenylborate precipitate hydrolysis specified in WSRC-RP-92-737. The report is divided into two sections, the first dealing with lab-scale precipitate hydrolysis experimentation while the second part addresses large-scale runs conducted to demonstrate the revised operating parameters in the Precipitate Hydrolysis Experimental Facility (PHEF). The program was in conjunction with reducing the nitrite ion level in DWPF feed.

  18. Technical bases for precipitate hydrolysis process operating parameters

    SciTech Connect

    Bannochie, C.J.; Lambert, D.P.

    1992-11-09

    This report provides the experimental data and rationale in support of the operating parameters for tetraphenylborate precipitate hydrolysis specified in WSRC-RP-92-737. The report is divided into two sections, the first dealing with lab-scale precipitate hydrolysis experimentation while the second part addresses large-scale runs conducted to demonstrate the revised operating parameters in the Precipitate Hydrolysis Experimental Facility (PHEF). The program was in conjunction with reducing the nitrite ion level in DWPF feed.

  19. Processing energetic materials with supercritical fluid precipitation techniques

    NASA Astrophysics Data System (ADS)

    Essel, Jonathan

    Research has shown that nano-sized particles of explosives have a reduced sensitivity to impact and shock. Nano-sized energetic particles have also shown promise in improving the performance of propellants and explosives. Therefore, a method to produce nano-sized explosive particles could be ideal for sensitivity and performance reasons. Supercritical fluid precipitation has been shown to produce nano-sized explosive particles effectively. This research explores the feasibility of processing energetic materials using three different supercritical fluid precipitation techniques. The first technique is called the Rapid Expansion of a Supercritical Solution (RESS). The RESS process dissolves a solute in a supercritical fluid and then rapidly expands the resulting solution through a nozzle to produce small (nano-sized) and uniform particles from a high degree of supersaturation. The second technique is the Rapid Expansion of a Supercritical Solution into a Liquid Solvent (RESOLV) Process. This process is similar to the RESS process except the supercritical solution is expanded into a liquid and dispersant solution to reduce particle agglomeration and to reduce the size of the particles further. The final technique investigated is the Rapid Expansion of a Supercritical Solution with a Nonsolute (RESS-N) process in which the precipitating solute is used to encapsulate or coat a nonsoluble substance by heterogeneous nucleation. This works takes both a theoretical an empirical approach. On the theoretical side, a numerical code that accounts for nucleation and condensation in the RESS process was written in FORTRAN to predict how altering pre-expansion pressures and pre-expansion temperatures in the RESS process could affect the final particle size of the produced RDX. It was determined that pre-expansion temperature had a marginal impact on final particle size but higher pre-expansion pressures were beneficial in forming smaller particles. Also, a software program called

  20. Life cycle comparison of centralized wastewater treatment and urine source separation with struvite precipitation: Focus on urine nutrient management.

    PubMed

    Ishii, Stephanie K L; Boyer, Treavor H

    2015-08-01

    Alternative approaches to wastewater management including urine source separation have the potential to simultaneously improve multiple aspects of wastewater treatment, including reduced use of potable water for waste conveyance and improved contaminant removal, especially nutrients. In order to pursue such radical changes, system-level evaluations of urine source separation in community contexts are required. The focus of this life cycle assessment (LCA) is managing nutrients from urine produced in a residential setting with urine source separation and struvite precipitation, as compared with a centralized wastewater treatment approach. The life cycle impacts evaluated in this study pertain to construction of the urine source separation system and operation of drinking water treatment, decentralized urine treatment, and centralized wastewater treatment. System boundaries include fertilizer offsets resulting from the production of urine based struvite fertilizer. As calculated by the Tool for the Reduction and Assessment of Chemical and Other Environmental Impacts (TRACI), urine source separation with MgO addition for subsequent struvite precipitation with high P recovery (Scenario B) has the smallest environmental cost relative to existing centralized wastewater treatment (Scenario A) and urine source separation with MgO and Na3PO4 addition for subsequent struvite precipitation with concurrent high P and N recovery (Scenario C). Preliminary economic evaluations show that the three urine management scenarios are relatively equal on a monetary basis (<13% difference). The impacts of each urine management scenario are most sensitive to the assumed urine composition, the selected urine storage time, and the assumed electricity required to treat influent urine and toilet water used to convey urine at the centralized wastewater treatment plant. The importance of full nutrient recovery from urine in combination with the substantial chemical inputs required for N recovery

  1. Life cycle comparison of centralized wastewater treatment and urine source separation with struvite precipitation: Focus on urine nutrient management.

    PubMed

    Ishii, Stephanie K L; Boyer, Treavor H

    2015-08-01

    Alternative approaches to wastewater management including urine source separation have the potential to simultaneously improve multiple aspects of wastewater treatment, including reduced use of potable water for waste conveyance and improved contaminant removal, especially nutrients. In order to pursue such radical changes, system-level evaluations of urine source separation in community contexts are required. The focus of this life cycle assessment (LCA) is managing nutrients from urine produced in a residential setting with urine source separation and struvite precipitation, as compared with a centralized wastewater treatment approach. The life cycle impacts evaluated in this study pertain to construction of the urine source separation system and operation of drinking water treatment, decentralized urine treatment, and centralized wastewater treatment. System boundaries include fertilizer offsets resulting from the production of urine based struvite fertilizer. As calculated by the Tool for the Reduction and Assessment of Chemical and Other Environmental Impacts (TRACI), urine source separation with MgO addition for subsequent struvite precipitation with high P recovery (Scenario B) has the smallest environmental cost relative to existing centralized wastewater treatment (Scenario A) and urine source separation with MgO and Na3PO4 addition for subsequent struvite precipitation with concurrent high P and N recovery (Scenario C). Preliminary economic evaluations show that the three urine management scenarios are relatively equal on a monetary basis (<13% difference). The impacts of each urine management scenario are most sensitive to the assumed urine composition, the selected urine storage time, and the assumed electricity required to treat influent urine and toilet water used to convey urine at the centralized wastewater treatment plant. The importance of full nutrient recovery from urine in combination with the substantial chemical inputs required for N recovery

  2. SEPARATION PROCESS FOR ZIRCONIUM AND COMPOUNDS THEREOF

    DOEpatents

    Crandall, H.W.; Thomas, J.R.

    1959-06-30

    The separation of zirconium from columbium, rare earths, yttrium and the alkaline earth metals, such mixtures of elements occurring in zirconium ores or neutron irradiated uranium is described. According to the invention a suitable separation of zirconium from a one normal acidic aqueous solution containing salts, nitrates for example, of tetravalent zirconium, pentavalent columbium, yttrium, rare earths in the trivalent state and alkaline earths can be obtained by contacting the aqueous solution with a fluorinated beta diketonc alone or in an organic solvent solution, such as benzene, to form a zirconium chelate compound. When the organic solvent is present the zirconium chelate compound is directly extracted; otherwise it is separated by filtration. The zirconium may be recovered from contacting the organic solvent solution containing the chelated compound by back extraction with either an aqueous hydrofluoric acid or an oxalic acid solution.

  3. SEPARATION OF FISSION PRODUCT VALUES FROM THE HEXAVALENT PLUTONIUM BY CARRIER PRECIPITATION

    DOEpatents

    Davies, T.H.

    1959-12-15

    An improved precipitation of fission products on bismuth phosphate from an aqueous mineral acid solution also containing hexavalent plutonium by incorporating, prior to bismuth phosphate precipitation, from 0.05 to 2.5 grams/ liter of zirconium phosphate, niobium oxide. and/or lanthanum fluoride is described. The plutonium remains in solution.

  4. Using Visualization and Computation in the Analysis of Separation Processes

    ERIC Educational Resources Information Center

    Joo, Yong Lak; Choudhary, Devashish

    2006-01-01

    For decades, every chemical engineer has been asked to have a background in separations. The required separations course can, however, be uninspiring and superficial because understanding many separation processes involves conventional graphical methods and commercial process simulators. We utilize simple, user-­friendly mathematical software,…

  5. Sample selection and testing of separation processes

    NASA Technical Reports Server (NTRS)

    Karr, L. J.

    1985-01-01

    Phase partitioning, which has become an important tool for the separation and purification of biological materials, was studied. Instruments available for this technique were researched and a countercurrent distribution apparatus, the Biosheff MK2N, was purchased. Various proteins, polysaccharides and cells were studied as models to determine operating procedures and conditions for this piece of equipment. Results were compared with those obtained from other similar equipment, including a nonsynchronous coil planet centrifuge device. Additionally, work was done with affinity ligands attached to PEG, which can further enhance the separation capabilities of phase partitioning.

  6. PROCESS FOR SEPARATING PLUTONIUM FROM IMPURITIES

    DOEpatents

    Wahl, A.C.

    1957-11-12

    A method is described for separating plutonium from aqueous solutions containing uranium. It has been found that if the plutonium is reduced to its 3+ valence state, and the uranium present is left in its higher valence state, then the differences in solubility between certain salts (e.g., oxalates) of the trivalent plutonium and the hexavalent uranium can be used to separate the metals. This selective reduction of plutonium is accomplished by adding iodide ion to the solution, since iodide possesses an oxidation potential sufficient to reduce plutonium but not sufficient to reduce uranium.

  7. Separation of Am-Cm from Al(NO/sub 3/)/sub 3/ waste solutions by in-canyon-tank precipitation as oxalates

    SciTech Connect

    Gray, L.W.; Burney, G.A.; Wilson, T.W.; McKibben, J.M.; Bibler, N.E.; Holtzscheiter, E.W.; Campbell, T.G.

    1982-04-01

    A process for recovery of Am-Cm residues from high-activity waste concentrates has been developed specifically for application in Savannah River Plant (SRP) canyon tanks. The Am-Cm residues were collected from a campaign to produce plutonium containing high isotopic concentrations of /sup 242/Pu. The separation of Am-Cm from the high-activity waste stream, containing about 2M Al(NO/sub 3/)/sub 3/, is necessary to produce an acceptable feed solution for a later pressurized cation exchange chromatography separation and purification step. The new process includes formic acid denitration, adjustment of contaminating cations by evaporation and water dilution, and oxalate precipitation of the actinides and lanthanides. After washing, the precipitate was dissolved in 8M nitric acid and the oxalate was destroyed by nitric acid oxidation that was catalyzed by manganous ions. This new process generates about one-fourth the waste of the californium solvent extraction process, which it replaced. The new process also produces a cleaner feed solution for the pressurized cation exchange chromatography separation and purification step.

  8. PROCESS FOR SEPARATING URANIUM FISSION PRODUCTS

    DOEpatents

    Spedding, F.H.; Butler, T.A.; Johns, I.B.

    1959-03-10

    The removal of fission products such as strontium, barium, cesium, rubidium, or iodine from neutronirradiated uranium is described. Uranium halide or elemental halogen is added to melted irradiated uranium to convert the fission products to either more volatile compositions which vaporize from the melt or to higher melting point compositions which separate as solids.

  9. Process, including PSA and membrane separation, for separating hydrogen from hydrocarbons

    DOEpatents

    Baker, Richard W.; Lokhandwala, Kaaeid A.; He, Zhenjie; Pinnau, Ingo

    2001-01-01

    An improved process for separating hydrogen from hydrocarbons. The process includes a pressure swing adsorption step, a compression/cooling step and a membrane separation step. The membrane step relies on achieving a methane/hydrogen selectivity of at least about 2.5 under the conditions of the process.

  10. Disentangling the disabling process: insights from the precipitating events project.

    PubMed

    Gill, Thomas M

    2014-08-01

    Among older persons, disability in activities of daily living is common and highly morbid. The Precipitating Events Project (PEP Study), an ongoing longitudinal study of 754 initially nondisabled, community-living persons, aged 70 or older, was designed to further elucidate the epidemiology of disability, with the goal of informing the development of effective interventions to maintain and restore independent function. Over the past 16 years, participants have completed comprehensive, home-based assessments at 18-month intervals and have been interviewed monthly to reassess their functional status and ascertain intervening events, other health care utilization, and deaths. Findings from the PEP Study have demonstrated that the disabling process for many older persons is characterized by multiple and possibly interrelated disability episodes, even over relatively short periods of time, and that disability often results when an intervening event is superimposed upon a vulnerable host. Given the frequency of assessments, long duration of follow-up, and recent linkage to Medicare data, the PEP Study will continue to be an outstanding platform for disability research in older persons. In addition, as the number of decedents accrues, the PEP Study will increasingly become a valuable resource for investigating symptoms, function, and health care utilization at the end of life.

  11. Disentangling the Disabling Process: Insights From the Precipitating Events Project

    PubMed Central

    Gill, Thomas M.

    2014-01-01

    Among older persons, disability in activities of daily living is common and highly morbid. The Precipitating Events Project (PEP Study), an ongoing longitudinal study of 754 initially nondisabled, community-living persons, aged 70 or older, was designed to further elucidate the epidemiology of disability, with the goal of informing the development of effective interventions to maintain and restore independent function. Over the past 16 years, participants have completed comprehensive, home-based assessments at 18-month intervals and have been interviewed monthly to reassess their functional status and ascertain intervening events, other health care utilization, and deaths. Findings from the PEP Study have demonstrated that the disabling process for many older persons is characterized by multiple and possibly interrelated disability episodes, even over relatively short periods of time, and that disability often results when an intervening event is superimposed upon a vulnerable host. Given the frequency of assessments, long duration of follow-up, and recent linkage to Medicare data, the PEP Study will continue to be an outstanding platform for disability research in older persons. In addition, as the number of decedents accrues, the PEP Study will increasingly become a valuable resource for investigating symptoms, function, and health care utilization at the end of life. PMID:25035454

  12. Gas separation using membranes. 1: Optimization of the separation process using new cost parameters

    SciTech Connect

    Hinchliffe, A.B.; Porter, K.E.

    1997-03-01

    This is the first in a series of papers presenting new concepts for the development of membranes for gas separation. In this paper two new cost parameters, which are useful for costing and optimization of membrane gas separation systems, are described. The new parameters, cost permeability and effective selectivity, can be used to show the direction to be taken in membrane research and development. The new parameters are shown to predict accurately the cost of membrane separation plant by correlating bids from membrane plant suppliers using the new parameters with cross-flow design equations. The parameters are used to optimize the membrane gas separation of hydrogen and carbon monoxide for two commercially available membrane systems. The membrane separation is compared with the currently used method, cryogenic flash distillation. Economic evaluation methods are developed to compare different separation methods so that the process as a whole can be optimized. The evaluation shows that, for membrane gas separation, it is important to find the optimum degree of separation; when membrane separation is evaluated at the separation specification for the established cryogenic method, membranes are not competitive; however, when the process is optimized for membrane separation, the cost of separation reduces to less than 60% of the cryogenic separation.

  13. Conceptual design of distillation-based hybrid separation processes.

    PubMed

    Skiborowski, Mirko; Harwardt, Andreas; Marquardt, Wolfgang

    2013-01-01

    Hybrid separation processes combine different separation principles and constitute a promising design option for the separation of complex mixtures. Particularly, the integration of distillation with other unit operations can significantly improve the separation of close-boiling or azeotropic mixtures. Although the design of single-unit operations is well understood and supported by computational methods, the optimal design of flowsheets of hybrid separation processes is still a challenging task. The large number of operational and design degrees of freedom requires a systematic and optimization-based design approach. To this end, a structured approach, the so-called process synthesis framework, is proposed. This article reviews available computational methods for the conceptual design of distillation-based hybrid processes for the separation of liquid mixtures. Open problems are identified that must be addressed to finally establish a structured process synthesis framework for such processes.

  14. Focused beam reflectance measurement to monitor nimodipine precipitation process.

    PubMed

    Xu, Xiaoming; Siddiqui, Akhtar; Khan, Mansoor A

    2013-11-18

    Crystallization of nimodipine in liquid-filled soft gelatin capsule during storage was reported for some commercial products, resulting in product recalls due to product quality and more importantly safety concerns. In this study, a real time particle monitoring tool, focused beam reflectance measurement, was used to evaluate the precipitation conditions of nimodipine in co-solvents. Upon water addition, two particle populations were discovered, appearing at different percentage of water content. Two transitions (i.e. sudden increase in particle counts) were observed, possibility related to nucleation and crystal growth of nimodipine. Furthermore, lowering storage temperature increased the tendency of nimodipine precipitation. Most critically, it was determined that with certain excipient, the drug precipitation occurred at approximately 7% (w/w) water content. Considering that all the orally administered liquid filled soft gelatin capsule shells contain residue water content as plasticizer, moisture transfer from the shell to the formulation may occur during long term storage, resulting in drug precipitation, particularly under cold temperature conditions.

  15. PRECIPITATION OF PROTACTINIUM

    DOEpatents

    Moore, R.L.

    1958-07-15

    An lmprovement in the separation of protactinium from aqueous nitric acid solutions is described. 1t covers the use of lead dioxide and tin dioxide as carrier precipitates for the protactinium. In carrying out the process, divalent lead or divalent tin is addcd to the solution and oxidized, causing formation of a carrier precipitate of lead dioxide or stannic oxide, respectively.

  16. Multi-Element Preconcentration/Separation of Some Metal Ions in Environmental Samples by Using Co-precipitation.

    PubMed

    Soylak, Mustafa; Aydin, Ayse; Kizil, Nebiye

    2016-01-01

    A preconcentration/separation system for cadmium(II), nickel(II), copper(II), lead(II), iron(II), cobalt(II), and manganese(II) ions has been established prior to their atomic absorption spectrometric determinations. The procedure is based on the co-precipitation of these ions by the aid of a praseodymium hydroxide (Pr(OH)3) precipitate. The precipitate was dissolved in 0.5 mL of concentrated HNO3, and made up to 10.0 mL with water. The analytes were determined by a flame atomic absorption spectrometer. The effects of analytical parameters including pH, amounts of praseodymium as carrier element, sample volume, etc. on the recoveries of heavy metals were investigated. The effects of matrix ions were also examined. The limits of detection for analyte ions were found in the range between 0.7-5.2 μg/L. The validation of this present procedure was verified by the analysis of certified reference materials, TMDA-54.4 (fortified water) and NIST 1570a (spinach leaves). The proposed co-precipitation procedure was applied for the determination of cadmium(II), nickel(II), copper(II), lead(II), iron(II), cobalt(II), and manganese(II) ions in various environmental water samples.

  17. Multi-Element Preconcentration/Separation of Some Metal Ions in Environmental Samples by Using Co-precipitation.

    PubMed

    Soylak, Mustafa; Aydin, Ayse; Kizil, Nebiye

    2016-01-01

    A preconcentration/separation system for cadmium(II), nickel(II), copper(II), lead(II), iron(II), cobalt(II), and manganese(II) ions has been established prior to their atomic absorption spectrometric determinations. The procedure is based on the co-precipitation of these ions by the aid of a praseodymium hydroxide (Pr(OH)3) precipitate. The precipitate was dissolved in 0.5 mL of concentrated HNO3, and made up to 10.0 mL with water. The analytes were determined by a flame atomic absorption spectrometer. The effects of analytical parameters including pH, amounts of praseodymium as carrier element, sample volume, etc. on the recoveries of heavy metals were investigated. The effects of matrix ions were also examined. The limits of detection for analyte ions were found in the range between 0.7-5.2 μg/L. The validation of this present procedure was verified by the analysis of certified reference materials, TMDA-54.4 (fortified water) and NIST 1570a (spinach leaves). The proposed co-precipitation procedure was applied for the determination of cadmium(II), nickel(II), copper(II), lead(II), iron(II), cobalt(II), and manganese(II) ions in various environmental water samples. PMID:27053469

  18. EVALUATION OF ALTERNATIVE STRONIUM AND TRANSURANIC SEPARATION PROCESSES

    SciTech Connect

    SMALLEY CS

    2011-04-25

    In order to meet contract requirements on the concentrations of strontium-90 and transuranic isotopes in the immobilized low-activity waste, strontium-90 and transuranics must be removed from the supernate of tanks 241-AN-102 and 241-AN-107. The process currently proposed for this application is an in-tank precipitation process using strontium nitrate and sodium permanganate. Development work on the process has not proceeded since 2005. The purpose of the evaluation is to identify whether any promising alternative processes have been developed since this issue was last examined, evaluate the alternatives and the baseline process, and recommend which process should be carried forward.

  19. Thermodynamic Analysis of Nanoporous Membrane Separation Processes

    NASA Astrophysics Data System (ADS)

    Rogers, David; Rempe, Susan

    2011-03-01

    We give an analysis of desalination energy requirements in order to quantify the potential for future improvements in desalination membrane technology. Our thermodynamic analysis makes it possible to draw conclusions from the vast array of equilibrium molecular dynamics simulations present in the literature as well as create a standardized comparison for measuring and reporting experimental reverse osmosis material efficiency. Commonly employed methods for estimating minimum desalination energy costs have been revised to include operations at positive input stream recovery ratios using a thermodynamic cycle analogous to the Carnot cycle. Several gaps in the statistical mechanical theory of irreversible processes have also been identified which may in the future lead to improved communication between materials engineering models and statistical mechanical simulation. Simulation results for silica surfaces and nanochannels are also presented. Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  20. Analysis and computer tools for separation processes involving nonideal mixtures

    SciTech Connect

    Lucia, A.

    1992-05-01

    The objectives of this research, were to continue to further both the theoretical understanding of and the development of computer tools (algorithms) for separation processes involving nonideal mixtures. These objectives were divided into three interrelated major areas -- the mathematical analysis of the number of steady-state solutions to multistage separation processes, the numerical analysis of general, related fixed-point methods, and the development and implementation of computer tools for process simulation.

  1. Effects of separate urine collection on advanced nutrient removal processes.

    PubMed

    Wilsenach, J A; van Loosdrecht, M C M

    2004-02-15

    Municipal wastewater contains a mixture of minerals from different origins. Urine contributes 80% of the nitrogen (N) and 45% of the phosphate (P) load in wastewater. Effects of separate urine collection on BNR processes were evaluated by using a simulation model for an existing state-of-the-art biological nutrient removal process. It was found that increasing urine separation efficiency leads to lower nitrate effluent concentrations, while ammonium and phosphorus concentrations remain more or less the same. The improved nitrate effluent quality is most notable up to 50-60% urine separation. Urine separation allows primary sedimentation without an increase in the nitrate effluent concentration. Furthermore, urine separation increases the potential treatment capacity for raw and settled wastewater by 20% and 60%, respectively. Urine separation provides options for increasing the lifetime of existing treatment works.

  2. Pore-scale modeling of multiphase reactive transport with phase transitions and dissolution-precipitation processes in closed systems.

    PubMed

    Chen, Li; Kang, Qinjun; Robinson, Bruce A; He, Ya-Ling; Tao, Wen-Quan

    2013-04-01

    A pore-scale model based on the lattice Boltzmann (LB) method is developed for multiphase reactive transport with phase transitions and dissolution-precipitation processes. The model combines the single-component multiphase Shan-Chen LB model [X. Shan and H. Chen, Phys. Rev. E 47, 1815 (1993)], the mass transport LB model [S. P. Sullivan et al., Chem. Eng. Sci. 60, 3405 (2005)], and the dissolution-precipitation model [Q. Kang et al., J. Geophys. Res. 111, B05203 (2006)]. Care is taken to handle information on computational nodes undergoing solid-liquid or liquid-vapor phase changes to guarantee mass and momentum conservation. A general LB concentration boundary condition is proposed that can handle various concentration boundaries including reactive and moving boundaries with complex geometries. The pore-scale model can capture coupled nonlinear multiple physicochemical processes including multiphase flow with phase separations, mass transport, chemical reactions, dissolution-precipitation processes, and dynamic evolution of the pore geometries. The model is validated using several multiphase flow and reactive transport problems and then used to study the thermal migration of a brine inclusion in a salt crystal. Multiphase reactive transport phenomena with phase transitions between liquid-vapor phases and dissolution-precipitation processes of the salt in the closed inclusion are simulated and the effects of the initial inclusion size and temperature gradient on the thermal migration are investigated.

  3. Wavefield separation in the process of transform between data domains

    SciTech Connect

    Wei, X.; Wu, L.

    1994-12-31

    This paper describes a method of wave field separation. As the matrix of wave field separation is the function of the apparent slowness p and velocities, using the matrix in the processes of {tau}-p transform, f-k transform or discrete Radon transform, the velocities of Vp and Vs can vary with depth. The analysis and a practical example given in the paper show that the method is an efficient means in wave field separation.

  4. Technical and economical assessment of formic acid to recycle phosphorus from pig slurry by a combined acidification-precipitation process.

    PubMed

    Daumer, M-L; Picard, S; Saint-Cast, P; Dabert, P

    2010-08-15

    Dissolution by acidification followed by a liquid/solid separation and precipitation of phosphorus from the liquid phase is one possibility to recycle phosphorus from livestock effluents. To avoid increase of effluent salinity by using mineral acids in the recycling process, the efficiency of two organic acids, formic and acetic acid, in dissolving the mineral phosphorus from piggery wastewater was compared. The amount of formic acid needed to dissolve the phosphorus was reduced three fold, compared to acetic acid. The amount of magnesium oxide needed for further precipitation was decreased by two with formic acid. Neither the carbon load nor the effluent salinity was significantly increased by using formic acid. An economical comparison was performed for the chemical recycling process (mineral fertilizer) vs. centrifugation (organic fertilizer) considering the centrifugation and the mineral fertilizers sold in the market. After optimisation of the process, the product could be economically competitive with mineral fertilizer as superphosphate in less than 10 years. PMID:20471746

  5. Systematic investigation of the cavi-precipitation process for the production of ibuprofen nanocrystals.

    PubMed

    Sinha, Biswadip; Müller, Rainer H; Möschwitzer, Jan P

    2013-12-31

    Cavi-precipitation process is a combinative particle size reduction technology based on solvent-anti-solvent precipitation coupled high pressure homogenization (HPH). The cavi-precipitation can be used for the efficient production of drug nanocrystals (NC) with improved dissolution rate leading to better bioavailability. The work presented here demonstrates the advantage of cavi-precipitation process over the standard HPH processes and standard combination process (decoupled process) where precipitation is performed outside the homogenizer. The model compound ibuprofen (IBP) was solubilized in isopropanol (IPA) to constitute the solvent phase and mixed with the anti-solvent phase (0.1% (w/v) hydroxypropyl methylcellulose with 0.2% (w/v) sodium dodecyl sulphate) at different ratios to carry out the precipitation step. IBP-IPA-Water composition was selected from ternary diagram for a highly supersaturated zone to obtain smaller size particles. The mean particle size [d(0.5)] obtained by this process (300nm) was much smaller when compared to that obtained from the decoupled process (1.5μm). Optimization of the solvent-anti-solvent ratio and drug concentration was necessary to achieve a smaller particle size. PXRD and DSC results revealed that the solid state properties of the original IBP and the prepared NC samples by cavi-precipitation samples were similar.

  6. Metal-affinity separations: A new dimension in protein processing

    SciTech Connect

    Arnold, F.H. )

    1991-02-01

    Rapid growth in the preparative and high-resolution analytical applications of metal-affinity chromatography demonstrate the appeal of metal recognition as a basis for protein separations. Stable, inexpensive chelated metals effectively mimic biospecific interactions, providing selective ligands for protein binding. This article reviews recent progress in understanding the mechanisms of metal-protein recognition that underlie metal-affinity separations. Also discussed are schemes for integrating metal-affinity purifications into the expression and bioprocessing of recombinant proteins. Promising future developments include new metal-affinity processes for analytical and preparative-scale separations and a range of techniques for enhancing the selectivity of metal-affinity separations.

  7. Separation processes using expulsion from dilute supercritical solutions

    DOEpatents

    Cochran, Jr., Henry D.

    1993-01-01

    A process for separating isotopes as well as other mixtures by utilizing the behavior of dilute repulsive or weakly attractive elements of the mixtures as the critical point of the solvent is approached.

  8. Separation processes using expulsion from dilute supercritical solutions

    DOEpatents

    Cochran, H.D. Jr.

    1993-04-20

    A process is described for separating isotopes as well as other mixtures by utilizing the behavior of dilute repulsive or weakly attractive elements of the mixtures as the critical point of the solvent is approached.

  9. Automated separation process for radioanalytical purposes at nuclear power plants.

    PubMed

    Nagy, L G; Vajda, N; Vodicska, M; Zagyvai, P; Solymosi, J

    1987-10-01

    Chemical separation processes have been developed to remove the matrix components and thus to determine fission products, especially radioiodine nuclides, in the primary coolant of WWER-type nuclear reactors. Special procedures have been elaborated to enrich long-lived nuclides in waste waters to be released and to separate and enrich caesium isotopes in the environment. All processes are based mainly on ion-exchange separations using amorphous zirconium phosphate. Automated equipment was constructed to meet the demands of the plant personnel for serial analysis.

  10. Precipitation-adsorption process for the decontamination of nuclear waste supernates

    DOEpatents

    Lee, Lien-Mow; Kilpatrick, Lester L.

    1984-01-01

    High-level nuclear waste supernate is decontaminated of cesium by precipitation of the cesium and potassium with sodium tetraphenyl boron. Simultaneously, strontium-90 is removed from the waste supernate sorption of insoluble sodium titanate. The waste solution is then filtered to separate the solution decontaminated of cesium and strontium.

  11. Precipitation-adsorption process for the decontamination of nuclear waste supernates

    DOEpatents

    Lee, L.M.; Kilpatrick, L.L.

    1982-05-19

    High-level nuclear waste supernate is decontaminated of cesium by precipitation of the cesium and potassium with sodium tetraphenyl boron. Simultaneously, strontium-90 is removed from the waste supernate sorption of insoluble sodium titanate. The waste solution is then filtered to separate the solution decontaminated of cesium and strontium.

  12. Design of a continuous process setup for precipitated calcium carbonate production from steel converter slag.

    PubMed

    Mattila, Hannu-Petteri; Zevenhoven, Ron

    2014-03-01

    A mineral carbonation process "slag2PCC" for carbon capture, utilization, and storage is discussed. Ca is extracted from steel slag by an ammonium salt solvent and carbonated with gaseous CO2 after the separation of the residual slag. The solvent is reused after regeneration. The effects of slag properties such as the content of free lime, fractions of Ca, Si, Fe, and V, particle size, and slag storage on the Ca extraction efficiency are studied. Small particles with a high free-lime content and minor fractions of Si and V are the most suitable. To limit the amount of impurities in the process, the slag-to-liquid ratio should remain below a certain value, which depends on the slag composition. Also, the design of a continuous test setup (total volume ∼75 L) is described, which enables quick process variations needed to adapt the system to the varying slag quality. Different precipitated calcium carbonate crystals (calcite and vaterite) are generated in different parts of the setup.

  13. CONCENTRATION OF Pu USING AN IODATE PRECIPITATE

    DOEpatents

    Fries, B.A.

    1960-02-23

    A method is given for separating plutonium from lanthanum in a lanthanum fluoride carrier precipitation process for the recovery of plutonium values from an aqueous solution. The carrier precipitation process includes the steps of forming a lanthanum fluoride precipi- . tate, thereby carrying plutonium out of solution, metathesizing the fluoride precipitate to a hydroxide precipitate, and then dissolving the hydroxide precipitate in nitric acid. In accordance with the invention, the nitric acid solution, which contains plutonium and lanthanum, is made 0.05 to 0.15 molar in potassium iodate. thereby precipitating plutonium as plutonous iodate and the plutonous iodate is separated from the lanthanum- containing supernatant solution.

  14. Performance of biofuel processes utilising separate lignin and carbohydrate processing.

    PubMed

    Melin, Kristian; Kohl, Thomas; Koskinen, Jukka; Hurme, Markku

    2015-09-01

    Novel biofuel pathways with increased product yields are evaluated against conventional lignocellulosic biofuel production processes: methanol or methane production via gasification and ethanol production via steam-explosion pre-treatment. The novel processes studied are ethanol production combined with methanol production by gasification, hydrocarbon fuel production with additional hydrogen produced from lignin residue gasification, methanol or methane synthesis using synthesis gas from lignin residue gasification and additional hydrogen obtained by aqueous phase reforming in synthesis gas production. The material and energy balances of the processes were calculated by Aspen flow sheet models and add on excel calculations applicable at the conceptual design stage to evaluate the pre-feasibility of the alternatives. The processes were compared using the following criteria: energy efficiency from biomass to products, primary energy efficiency, GHG reduction potential and economy (expressed as net present value: NPV). Several novel biorefinery concepts gave higher energy yields, GHG reduction potential and NPV. PMID:26056782

  15. Performance of biofuel processes utilising separate lignin and carbohydrate processing.

    PubMed

    Melin, Kristian; Kohl, Thomas; Koskinen, Jukka; Hurme, Markku

    2015-09-01

    Novel biofuel pathways with increased product yields are evaluated against conventional lignocellulosic biofuel production processes: methanol or methane production via gasification and ethanol production via steam-explosion pre-treatment. The novel processes studied are ethanol production combined with methanol production by gasification, hydrocarbon fuel production with additional hydrogen produced from lignin residue gasification, methanol or methane synthesis using synthesis gas from lignin residue gasification and additional hydrogen obtained by aqueous phase reforming in synthesis gas production. The material and energy balances of the processes were calculated by Aspen flow sheet models and add on excel calculations applicable at the conceptual design stage to evaluate the pre-feasibility of the alternatives. The processes were compared using the following criteria: energy efficiency from biomass to products, primary energy efficiency, GHG reduction potential and economy (expressed as net present value: NPV). Several novel biorefinery concepts gave higher energy yields, GHG reduction potential and NPV.

  16. Bone marrow processing for transplantation using Cobe Spectra cell separator.

    PubMed

    Veljković, Dobrila; Nonković, Olivera Šerbić; Radonjić, Zorica; Kuzmanović, Miloš; Zečević, Zeljko

    2013-06-01

    Concentration of bone marrow aspirates is an important prerequisite prior to infusion of ABO incompatible allogeneic marrow and prior to cryopreservation and storage of autologous marrow. In this paper we present our experience in processing 15 harvested bone marrow for ABO incompatible allogeneic and autologous bone marrow (BM) transplantation using Cobe Spectra® cell separator. BM processing resulted in the median recovery of 91.5% CD34+ cells, erythrocyte depletion of 91% and volume reduction of 81%. BM processing using cell separator is safe and effective technique providing high rate of erythrocyte depletion and volume reduction, and acceptable recovery of the CD34+ cells.

  17. SOLVENT EXTRACTION PROCESS FOR SEPARATING ACTINIDE AND LANTHANIDE METAL VALUES

    DOEpatents

    Hildebrandt, R.A.; Hyman, H.H.; Vogler, S.

    1962-08-14

    A process of countercurrently extracting an aqueous mineral acid feed solution for the separation of actinides from lanthanides dissolved therern is described. The feed solution is made acid-defrcient with alkali metal hydroxide prior to.contact with acid extractant; during extraction, however, acid is transferred from organic to aqueous solution and the aqueous solution gradually becomes acid. The acid-deficient phase ' of the process promotes the extraction of the actinides, while the latter acid phase'' of the process improves retention of the lanthanides in the aqueous solution. This provides for an improved separation. (AEC)

  18. EFFECT OF SEPARATION PROCESSES ON THE FORMATION OF BROMINATED THMS

    EPA Science Inventory

    Separation treatment processes are being investigated as a way to control the formation of disinfection by-products (DBPs) in finished waters. These processes remove natural organic matter before a disinfection is applied, thus limiting the amount of material available to form D...

  19. A Reverse Osmosis System for an Advanced Separation Process Laboratory.

    ERIC Educational Resources Information Center

    Slater, C. S.; Paccione, J. D.

    1987-01-01

    Focuses on the development of a pilot unit for use in an advanced separations process laboratory in an effort to develop experiments on such processes as reverse osmosis, ultrafiltration, adsorption, and chromatography. Discusses reverse osmosis principles, the experimental system design, and some experimental studies. (TW)

  20. PRECP: the Department of Energy's program on the nonlinearity of acid precipitation processes

    SciTech Connect

    Tanner, R.L.; Tichler, J.; Brown, R.; Davis, W.; Johnson, S.; Patrinos, A.A.N.; Sisterson, D.; Slinn, W.G.N.

    1986-09-01

    During the period of 1 April to 3 May 1985, staff from Argonne National Laboratory (ANL), Brookhaven National Laboratory (BNL), and Pacific Northwest Laboratory (PNL), participated in a multifaceted, coordinated set of field studies from an aircraft logistical base in Columbus, OH, and a surface precipitation and air chemistry network in the Philadelphia area. The general goals of these activities, conducted within the DOE-sponsored PRocessing of Emissions by Clouds and Precipitation (PRECP) program were to obtain information concerning scavenging ratios and the vertical distribution of cloud and precipitation chemistry for sulfur and nitrogen oxides and oxyacids, and for oxidant species in the vicinity of precipitating and nonprecipitating clouds. Profiling of pollutant concentrations and phase distributions, and studies of scavenging processes were accomplished principally by airborne measurements of aerosol and gaseous species in pre-cloud and below-cloud air and of aqueous-phase species in clouds and precipitation, accompanied by documentation of meteorological and cloud physics parameters in the sampled regimes. Studies in the Midwest utilized only limited surface precipitation collection and chemical measurements, whereas a more extensive ground precipitation network was deployed in the Philadelphia area studies together with surface air chemistry measurements at a single nonurban site.

  1. A NEW PROCESS DEVELOPED FOR SEPARATION OF LIGNIN FROM AMMONIUM HYDROXIDE PRETREATMENT SOLUTIONS

    SciTech Connect

    Sherman, S.; Gorensek, M.; Milliken, C.

    2010-12-14

    A method is described for separating lignin from liquid solutions resulting from the pretreatment of lignocellulosic materials such as switchgrass with ammonium hydroxide. The method involves a sequence of steps including acidification, evaporation, and precipitation or centrifugation that are performed under defined conditions, and results in a relatively pure, solid lignin product. The method is tested on ammonium hydroxide solutions containing lignin extracted from switchgrass. Experimental results show that the method is capable of recovering between 66-95% of dissolved lignin as a precipitated solid. Cost estimates of pilot-scale and industrial-scale expressions of the process indicate that breakeven lignin prices of $2.36/kg and $0.78/kg, respectively, may be obtainable with this recovery method.

  2. Identification of RNase-resistant RNAs in Saccharomyces cerevisiae extracts: Separation from chromosomal DNA by selective precipitation.

    PubMed

    Rodriguez, Blanca V; Malczewskyj, Eric T; Cabiya, Joshua M; Lewis, L Kevin; Maeder, Corina

    2016-01-01

    High-quality chromosomal DNA is a requirement for many biochemical and molecular biological techniques. To isolate cellular DNA, standard protocols typically lyse cells and separate nucleic acids from other biological molecules using a combination of chemical and physical methods. After a standard chemical-based protocol to isolate chromosomal DNA from Saccharomyces cerevisiae and then treatment with RNase A to degrade RNA, two RNase-resistant bands persisted when analyzed using gel electrophoresis. Interestingly, such resistant bands did not appear in preparations of Escherichia coli bacterial DNA after RNase treatment. Several enzymatic, chemical, and physical methods were employed in an effort to remove the resistant RNAs, including use of multiple RNases and alcohol precipitation, base hydrolysis, and chromatographic methods. These experiments resulted in the development of a new method for isolation of S. cerevisiae chromosomal DNA. This method utilizes selective precipitation of DNA in the presence of a potassium acetate/isopropanol mixture and produces high yields of chromosomal DNA without detectable contaminating RNAs.

  3. Separation of products from mild coal gasification processes

    SciTech Connect

    Wallman, P.H.

    1991-09-11

    The primary mild coal gasification product mixture containing noncondensible gas, high-boiling hydrocarbon vapors and entrained fines is difficult to process into the desired pure products: gas, liquids, and dry solids. This challenge for mild coal gasification process development has been studied by surveying the technical literature for suitable separations processes and for similar issues in related processes. The choice for a first-stage solids separation step is standard cyclones, arranged in parallel trains for large-volume applications in order to take advantage of the higher separation efficiency of smaller cyclones. However, mild gasification pilot-plant data show entrainment of ultrafine particles for which standard cyclones have poor separation efficiency. A hot secondary solids separation step is needed for the ultrafine entrainment in order to protect the liquid product from excessive amounts of contaminating solids. The secondary solids separation step is similar to many high-temperature flue-gas applications with an important complicating condition: Mild gasifier vapors form coke on surfaces in contact with the vapors. Plugging of the filter medium by coke deposition is concluded to be the main product separation problem for mild gasification. Three approaches to solution of this problem are discussed in the order of preference: (1) a barrier filter medium made of a perforated foil that is easy to regenerate, (2) a high-efficiency cyclone coupled with recycle of a solids-containing tar fraction for coking/cracking in the gasifier, and (3) a granular moving bed filter with regeneration of the bed material. The condensation of oil vapors diluted by noncondensible gas is analyzed thermodynamically, and the conclusion is that existing commercial oil fractionator designs are adequate as long as the vapor stream does not contain excessive amounts of solids. 34 refs., 4 figs.

  4. Enhanced synergistic denitrification and chemical precipitation in a modified BAF process by using Fe2+.

    PubMed

    Wang, Hongjie; Dong, Wengyi; Li, Ting; Liu, Tongzhou

    2014-01-01

    A series of laboratory-scale experiments for examining the feasibility and suitability of using Fe(2+) as the precipitant dosed in the pre-denitrification stage of a modified BAF process employing simultaneous chemical precipitation of TSS and phosphorus were carried out. The effects of dosing Fe(2+) on effluent quality and sludge characteristics of the pre-denitrification stage were assessed with comparing to the cases of no additional chemical dosing and dosing Fe(3+). Results obtained demonstrated a sound performance of synergistic denitrification and chemical precipitation in pre-denitrification of the modified BAF process when dosing Fe salts, which showed enhanced by using Fe(2+) as the dosed precipitant in increasing the denitrification loading rate, exhibiting a better controlling of the residual phosphorus in pre-denitrification effluent, and improving sludge settleability. Dosing Fe salt showed no adverse impact in removing COD, but resulted in a relatively higher SS content in the pre-denitrification effluent.

  5. Soda ash improves lead removal in lime precipitation process

    SciTech Connect

    Hsu, D.Y.; Riddell, M.D.R.; Bonamico, B.

    1982-01-01

    Both laboratory-scale and plant-scale studies were conducted to evaluate the feasibility of using soda ash as a supplemental chemical in the existing lime neutralization-sedimentation process. The purpose was to improve the efficiency of lead removal from a metal finishing wastewater by taking advantage of the lower solubility of lead carbonate. Plant-scale studies indicated that addition of soda ash at about 2 mg Na/sub 2/CO/sub 3/ per mg Pb and at a pH between 8 and 11.5 reduced lead content in the settled effluent consistently to less than 0.3 mg/l. This is considerably lower than the 0.5 mg/1 specified in the sewer use ordinance. After about one year's operation, this modified lime neutralization-sedimentation process has been found to be more stable and reliable, and requires less attendance than the simple lime process. The process can also now be operated at a lower pH (minimum: 7.0) with the addition of soda ash, which has resulted in a lower amount of sludge production, lower lime usage and significantly lower manpower requirements.

  6. Tributylphosphate in the In-Tank Precipitation Process Facilities

    SciTech Connect

    Barnes, M.J.; Hobbs, D.T.; Swingle, R.F.

    1993-11-23

    A material balance investigation and evaluation of n- tributylphosphate (TBP) recycle throughout ITP and its carryover to Defense Waste Processing Facility (DWPF) was performed. Criticality and DWPF-related issues were determined to pose no adverse consequences due to TBP addition. Effects of decomposition products were also considered. Flammability of 1-butanol, a TBP decomposition product, in Tank 22 was investigated. Calculations show that Tank 22 would be ventilated with air at a rate sufficient to maintain a 1-butanol concentration (volume percent) well below 25 percent of the lower flammability limit (LFL) for 1-butanol.

  7. Separate and combined effects of temperature and precipitation change on maize yields in sub-Saharan Africa for mid- to late-21st century

    NASA Astrophysics Data System (ADS)

    Waha, K.; Müller, C.; Rolinski, S.

    2013-07-01

    Maize (Zea mays L.) is one of the most important food crops and very common in all parts of sub-Saharan Africa. In 2010 53 million tons of maize were produced in sub-Saharan Africa on about one third of the total harvested cropland area (~ 33 million ha). Our aim is to identify the limiting agroclimatic variable for maize growth and development in sub-Saharan Africa by analyzing the separated and combined effects of temperature and precipitation. Under changing climate, both climate variables are projected to change severely, and their impacts on crop yields are frequently assessed using process-based crop models. However it is often unclear which agroclimatic variable will have the strongest influence on crop growth and development under climate change and previous studies disagree over this question.

  8. Production of stable isotopes utilizing the plasma separation process

    NASA Astrophysics Data System (ADS)

    Bigelow, T. S.; Tarallo, F. J.; Stevenson, N. R.

    2005-12-01

    A plasma separation process (PSP) is being operated at Theragenics Corporation's®, Oak Ridge, TN, facility for the enrichment of stable isotopes. The PSP utilizes ion cyclotron mass discrimination to separate isotopes on a relatively large scale. With a few exceptions, nearly any metallic element could be processed with PSP. Output isotope enrichment factor depends on natural abundance and mass separation and can be fairly high in some cases. The Theragenics™ PSP facility is believed to be the only such process currently in operation. This system was developed and formerly operated under the US Department of Energy Advanced Isotope Separation program. Theragenics™ also has a laboratory at the PSP site capable of harvesting the isotopes from the process and a mass spectrometer system for analyzing enrichment and product purity. Since becoming operational in 2002, Theragenics™ has utilized the PSP to separate isotopes of several elements including: dysprosium, erbium, gadolinium, molybdenum and nickel. Currently, Theragenics™ is using the PSP for the separation of 102Pd, which is used as precursor for the production of 103Pd. The 103Pd radioisotope is the active ingredient in TheraSeed®, which is used in the treatment of early stage prostate cancer and being investigated for other medical applications. New industrial, medical and research applications are being investigated for isotopes that can be enriched on the PSP. Pre-enrichment of accelerator or reactor targets offers improved radioisotope production. Theragenics operates 14 cyclotrons for proton activation and has access to HFIR at ORNL for neutron activation of radioisotopes.

  9. A Preliminary Analysis of Precipitation Properties and Processes during NASA GPM IFloodS

    NASA Technical Reports Server (NTRS)

    Carey, Lawrence; Gatlin, Patrick; Petersen, Walt; Wingo, Matt; Lang, Timothy; Wolff, Dave

    2014-01-01

    The Iowa Flood Studies (IFloodS) is a NASA Global Precipitation Measurement (GPM) ground measurement campaign, which took place in eastern Iowa from May 1 to June 15, 2013. The goals of the field campaign were to collect detailed measurements of surface precipitation using ground instruments and advanced weather radars while simultaneously collecting data from satellites passing overhead. Data collected by the radars and other ground instruments, such as disdrometers and rain gauges, will be used to characterize precipitation properties throughout the vertical column, including the precipitation type (e.g., rain, graupel, hail, aggregates, ice crystals), precipitation amounts (e.g., rain rate), and the size and shape of raindrops. The impact of physical processes, such as aggregation, melting, breakup and coalescence on the measured liquid and ice precipitation properties will be investigated. These ground observations will ultimately be used to improve rainfall estimates from satellites and in particular the algorithms that interpret raw data for the upcoming GPM mission's Core Observatory satellite, which launches in 2014. The various precipitation data collected will eventually be used as input to flood forecasting models in an effort to improve capabilities and test the utility and limitations of satellite precipitation data for flood forecasting. In this preliminary study, the focus will be on analysis of NASA NPOL (S-band, polarimetric) radar (e.g., radar reflectivity, differential reflectivity, differential phase, correlation coefficient) and NASA 2D Video Disdrometers (2DVDs) measurements. Quality control and processing of the radar and disdrometer data sets will be outlined. In analyzing preliminary cases, particular emphasis will be placed on 1) documenting the evolution of the rain drop size distribution (DSD) as a function of column melting processes and 2) assessing the impact of range on ground-based polarimetric radar estimates of DSD properties.

  10. Process of treating cellulosic membrane and alkaline with membrane separator

    NASA Technical Reports Server (NTRS)

    Hoyt, H. E.; Pfluger, H. L. (Inventor)

    1970-01-01

    The improvement of water-soluble cellulose ether membranes for use as separators in concentrated alkaline battery cells is discussed. The process of contacting membranes with an aqueous alkali solution of concentration less than that of the alkali solution to be used in the battery but above that at which the membrane is soluble is described.

  11. Efficient Separations and Processing Crosscutting Program. Technology summary

    SciTech Connect

    1995-06-01

    The Efficient Separations and Processing (ESP) Crosscutting Program was created in 1991 to identify, develop, and perfect separations technologies and processes to treat wastes and address environmental problems throughout the DOE Complex. The ESP funds several multi-year tasks that address high-priority waste remediation problems involving high-level, low-level, transuranic, hazardous, and mixed (radioactive and hazardous) wastes. The ESP supports applied research and development (R and D) leading to demonstration or use of these separations technologies by other organizations within DOE-EM. Treating essentially all DOE defense wastes requires separation methods that concentrate the contaminants and/or purify waste streams for release to the environment or for downgrading to a waste form less difficult and expensive to dispose of. Initially, ESP R and D efforts focused on treatment of high-level waste (HLW) from underground storage tanks (USTs) because of the potential for large reductions in disposal costs and hazards. As further separations needs emerge and as waste management and environmental restoration priorities change, the program has evolved to encompass the breadth of waste management and environmental remediation problems.

  12. Development of the Actinide-Lanthanide Separation (ALSEP) Process

    SciTech Connect

    Lumetta, Gregg J.; Carter, Jennifer C.; Niver, Cynthia M.; Gelis, Artem V.

    2014-09-30

    Separating the minor actinide elements (Am and Cm) from acidic high-level raffinates arising from the reprocessing of irradiated nuclear fuel is an important step in closing the nuclear fuel cycle. Most proposed approaches to this problem involve two solvent extraction steps: 1) co-extraction of the trivalent lanthanides and actinides, followed by 2) separation of the actinides from the lanthanides. The objective of our work is to develop a single solvent-extraction process for isolating the minor actinide elements. We report here a solvent containing N,N,N',N'-tetra(2 ethylhexyl)diglycolamide (T2EHDGA) combined with 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (HEH[EHP]) that can be used to separate the minor actinides in a single solvent-extraction process. T2EHDGA serves to co-extract the trivalent actinide and lanthanide ions from nitric acid solution. Switching the aqueous phase chemistry to a citrate buffered solution of N-(2-hydroxyethyl)ethylenediamine-N,N',N'-triacetic acid at pH 2.5 to 4 results in selective transfer of the actinides to the aqueous phase, thus affecting separation of the actinides from the lanthanides. Separation factors between the lanthanides and actinides are approximately 20 in the pH range of 3 to 4, and the distribution ratios are not highly dependent on the pH in this system.

  13. An Improved Process for Precipitating Cyanide Ions from the Barren Solution at Different pHs

    NASA Astrophysics Data System (ADS)

    Figueroa, Gabriela V.; Parga, José R.; Valenzuela, Jesus L.; Vázquez, Victor; Valenzuela, Alejandro; Rodriguez, Mario

    2016-02-01

    In recent decades, the use of metal sulfides instead of hydroxide precipitation in hydrometallurgical processes has gained prominence. Some arguments for its preferential use are as follows: a high degree of metal removal at relatively low pH values, the sparingly soluble nature of sulfide precipitates, favorable dewatering characteristics, and the stability of the formed metal sulfides. The Merrill-Crowe zinc-precipitation process has been applied worldwide in a large number of operations for the recovery of gold and silver from cyanide solutions. However, in some larger plants, the quality of this precious precipitate is low because copper, zinc and especially lead are precipitated along with gold and silver. This results in higher consumption of zinc dust and flux during the smelting of the precipitate, the formation of the matte, and a shorter crucible life. The results show that pH has a significant effect on the removal efficiency of zinc and copper cyanide ions. The optimal pH range was determined to be 3-4, and the removal efficiency of zinc and copper cyanide ions was up to 99%.

  14. PROCESS USING POTASSIUM LANTHANUM SULFATE FOR FORMING A CARRIER PRECIPITATE FOR PLUTONIUM VALUES

    DOEpatents

    Angerman, A.A.

    1958-10-21

    A process is presented for recovering plutonium values in an oxidation state not greater than +4 from fluoride-soluble fission products. The process consists of adding to an aqueous acidic solution of such plutonium values a crystalline potassium lanthanum sulfate precipitate which carries the plutonium values from the solution.

  15. Process to remove actinides from soil using magnetic separation

    DOEpatents

    Avens, Larry R.; Hill, Dallas D.; Prenger, F. Coyne; Stewart, Walter F.; Tolt, Thomas L.; Worl, Laura A.

    1996-01-01

    A process of separating actinide-containing components from an admixture including forming a slurry including actinide-containing components within an admixture, said slurry including a dispersion-promoting surfactant, adjusting the pH of the slurry to within a desired range, and, passing said slurry through a pretreated matrix material, said matrix material adapted to generate high magnetic field gradients upon the application of a strong magnetic field exceeding about 0.1 Tesla whereupon a portion of said actinide-containing components are separated from said slurry and remain adhered upon said matrix material is provided.

  16. CATIONIC EXCHANGE PROCESS FOR THE SEPARATION OF RARE EARTHS

    DOEpatents

    Choppin, G.R.; Thompson, S.G.; Harvey, B.G.

    1960-02-16

    A process for separating mixtures of elements in the lanthanum and actinium series of the periodic table is described. The mixture of elements is dissolved in 0.05 M HCI, wherein the elements exist as tripositive ions. The resulting solution is then transferred to a column of cationic exchange resin and the column eluted with 0.1 to 0.6 M aqueous ammonium alpha hydroxy isobutyrate solution of pH 3.8 to 5.0. The use of ammonium alpha hydroxy isobutyrate as an eluting agent results in sharper and more rapid separations than previously obtainable with eluants such as citric, tartaric, glycolic, and lactic acids.

  17. Optimization of tetanus toxoid ammonium sulfate precipitation process using response surface methodology.

    PubMed

    Brgles, Marija; Prebeg, Pero; Kurtović, Tihana; Ranić, Jelena; Marchetti-Deschmann, Martina; Allmaier, Günter; Halassy, Beata

    2016-10-01

    Tetanus toxoid (TTd) is a highly immunogenic, detoxified form of tetanus toxin, a causative agent of tetanus disease, produced by Clostridium tetani. Since tetanus disease cannot be eradicated but is easily prevented by vaccination, the need for the tetanus vaccine is permanent. The aim of this work was to investigate the possibility of optimizing TTd purification, i.e., ammonium sulfate precipitation process. The influence of the percentage of ammonium sulfate, starting amount of TTd, buffer type, pH, temperature, and starting purity of TTd on the purification process were investigated using optimal design for response surface models. Responses measured for evaluation of the ammonium sulfate precipitation process were TTd amount (Lf/mL) and total protein content. These two parameters were used to calculate purity (Lf/mgPN) and the yield of the process. Results indicate that citrate buffer, lower temperature, and lower starting amount of TTd result in higher purities of precipitates. Gel electrophoresis combined with matrix-assisted laser desorption ionization-mass spectrometric analysis of precipitates revealed that there are no inter-protein cross-links and that all contaminating proteins have pIs similar to TTd, so this is most probably the reason for the limited success of purification by precipitation.

  18. Magnetic separation as a plutonium residue enrichment process

    SciTech Connect

    Avens, L.R.; McFarlan, J.T.; Gallegos, U.F.

    1989-01-01

    We have subjected several plutonium contaminated residues to Open Gradient Magnetic Separation (OGMS) on an experimental scale. Separation of graphite, bomb reduction sand, and bomb reduction sand, and bomb reduction sand, slag, and crucible, resulted in a plutonium rich fraction and a plutonium lean fraction. The lean fraction varied between about 20% to 85% of the feed bulk. The plutonium content of the lean fraction can be reduced from about 2% in the feed to the 0.1% to 0.5% range dependent on the portion of the feed rejected to this lean fraction. These values are low enough in plutonium to meet economic discard limits and be considered for direct discard. Magnetic separation of direct oxide reduction and electrorefining pyrochemical salts gave less favorable results. While a fraction very rich in plutonium could be obtained, the plutonium content of the lean fraction was to high for direct discard. This may still have chemical processing applications. OGMS experiments at low magnetic field strength on incinerator ash did give two fractions but the plutonium content of each fraction was essentially identical. Thus, no chemical processing advantage was identified for magnetic separation of this residue. The detailed results of these experiments and the implications for OGMS use in recycle plutonium processing are discussed. 4 refs., 3 figs., 9 tabs.

  19. Prediction of Separation Performance of Dry High Intensity Magnetic Separator for Processing of Para-Magnetic Minerals

    NASA Astrophysics Data System (ADS)

    Tripathy, Sunil Kumar; Singh, Veerendra; Suresh, Nikkam

    2015-10-01

    High intensity dry magnetic separators are gaining popularity for the separation of para-magnetic minerals due to the cost economic factor. Induced roll magnetic separator is found to be an effective dry separator for the separation of fine particles. Separation efficiency of this separator depends on mineral characteristics and the design features of equipment along with the optimization of process variables. Present investigation focuses on the prediction and validation of separation performance of minerals while treating in induced roll magnetic separator. Prediction of the separation is expressed in terms of separation angle at which a particle leaves the rotor surface by using a modified particle flow model derived by Cakir. The validation of the model is carried by capturing the particle trajectory using an image analyzer. It is found that Cakir's mathematical model produces reliable results and a new model is proposed to increase the reliability of separation angle prediction by including the particle shape factor.

  20. DECONTAMINATION OF PLUTONIUM FOR FLUORIDE AND CHLORIDE DURING OXALATE PRECIPITATION, FILTRATION AND CALCINATION PROCESSES

    SciTech Connect

    Kyser, E.

    2012-07-25

    Due to analytical limitations for the determination of fluoride (F) and chloride (Cl) in a previous anion exchange study, an additional study of the decontamination of Pu from F and Cl by oxalate precipitation, filtration and calcination was performed. Anion product solution from the previous impurity study was precipitated as an oxalate, filtered, and calcined to produce an oxide for analysis by pyrohydrolysis for total Cl and F. Analysis of samples from this experiment achieved the purity specification for Cl and F for the proposed AFS-2 process. Decontamination factors (DF's) for the overall process (including anion exchange) achieved a DF of {approx}5000 for F and a DF of {approx}100 for Cl. Similar experiments where both HF and HCl were spiked into the anion product solution to a {approx}5000 {micro}g /g Pu concentration showed a DF of 5 for F and a DF of 35 for Cl across the combined precipitation-filtration-calcination process steps.

  1. Pressure swing permeation: Novel process for gas separation by membranes

    SciTech Connect

    Feng, X.; Pan, C.Y.; Ivory, J.

    2000-04-01

    A novel process for gas separation, called pressure swing permeation, was investigated to elevate the relatively low permeate pressure by pressurization with high-pressure feed gas, thereby reducing or eliminating additional permeate compression costs where a pressurized permeate is required. This process uses two or more membrane modules and operates in a cyclic fashion, with each module repeatedly undergoing the sequential steps of feed admission and permeation, residual removal, permeate reception, permeate pressurization, and product withdrawal. The unsteady-state permeation associated with pressure swing permeation was studied parametrically, and a bench-scale unit compromising two hollow-fiber membrane modules in parallel was tested for H{sub 2}/N{sub 2} separation to demonstrate the effectiveness of the process. The permeate product at a pressure as high as the feed pressure can be produced without using a compressor. This is impossible with traditional steady-state processes where a pressure differential across the membrane must be maintained. The pressure swing permeation is analogous to pressure swing adsorption and has the potential to be synergistically integrated with the pressure swing adsorption process for enhanced separation of gases.

  2. CSER 00-003 Criticality Safety Evaluation report for PFP Magnesium Hydroxide Precipitation Process for Plutonium Stabilization Glovebox 3

    SciTech Connect

    LAN, J.S.

    2000-07-13

    This Criticality Safety Evaluation Report analyzes the stabilization of plutonium/uranium solutions in Glovebox 3 using the magnesium hydroxide precipitation process at PFP. The process covered are the receipt of diluted plutonium solutions into three precipitation tanks, the precipitation of plutonium from the solution, the filtering of the plutonium precipitate from the solution, the scraping of the precipitate from the filter into boats, and the initial drying of the precipitated slurry on a hot plate. A batch (up to 2.5 kg) is brought into the glovebox as plutonium nitrate, processed, and is then removed in boats for further processing. This CSER establishes limits for the magnesium hydroxide precipitation process in Glovebox 3 to maintain criticality safety while handling fissionable material.

  3. Automated process for solvent separation of organic/inorganic substance

    DOEpatents

    Schweighardt, Frank K.

    1986-01-01

    There is described an automated process for the solvent separation of organic/inorganic substances that operates continuously and unattended and eliminates potential errors resulting from subjectivity and the aging of the sample during analysis. In the process, metered amounts of one or more solvents are passed sequentially through a filter containing the sample under the direction of a microprocessor control apparatus. The mixture in the filter is agitated by ultrasonic cavitation for a timed period and the filtrate is collected. The filtrate of each solvent extraction is collected individually and the residue on the filter element is collected to complete the extraction process.

  4. Automated process for solvent separation of organic/inorganic substance

    DOEpatents

    Schweighardt, F.K.

    1986-07-29

    There is described an automated process for the solvent separation of organic/inorganic substances that operates continuously and unattended and eliminates potential errors resulting from subjectivity and the aging of the sample during analysis. In the process, metered amounts of one or more solvents are passed sequentially through a filter containing the sample under the direction of a microprocessor control apparatus. The mixture in the filter is agitated by ultrasonic cavitation for a timed period and the filtrate is collected. The filtrate of each solvent extraction is collected individually and the residue on the filter element is collected to complete the extraction process. 4 figs.

  5. Forecasting and nowcasting process: A case study analysis of severe precipitation event in Athens, Greece

    NASA Astrophysics Data System (ADS)

    Matsangouras, Ioannis; Nastos, Panagiotis; Avgoustoglou, Euripides; Gofa, Flora; Pytharoulis, Ioannis; Kamberakis, Nikolaos

    2016-04-01

    An early warning process is the result of interplay between the forecasting and nowcasting interactions. Therefore, (1) an accurate measurement and prediction of the spatial and temporal distribution of rainfall over an area and (2) the efficient and appropriate description of the catchment properties are important issues in atmospheric hazards (severe precipitation, flood, flash flood, etc.). In this paper, a forecasting and nowcasting analysis is presented, regarding a severe precipitation event that took place on September 21, 2015 in Athens, Greece. The severe precipitation caused a flash flood event at the suburbs of Athens, with significant impacts to the local society. Quantitative precipitation forecasts from European Centre for Medium-Range Weather Forecasts and from the COSMO.GR atmospheric model, including ensemble forecast of precipitation and probabilistic approaches are analyzed as tools in forecasting process. Satellite remote sensing data close and six hours prior to flash flood are presented, accompanied with radar products from Hellenic National Meteorological Service, illustrating the ability to depict the convection process.

  6. Precipitation process in a Mg–Gd–Y alloy grain-refined by Al addition

    SciTech Connect

    Dai, Jichun; Zhu, Suming; Easton, Mark A.; Xu, Wenfan; Wu, Guohua; Ding, Wenjiang

    2014-02-15

    The precipitation process in Mg–10Gd–3Y (wt.%) alloy grain-refined by 0.8 wt.% Al addition has been investigated by transmission electron microscopy. The alloy was given a solution treatment at 520 °C for 6 h plus 550 °C for 7 h before ageing at 250 °C. Plate-shaped intermetallic particles with the 18R-type long-period stacking ordered structure were observed in the solution-treated state. Upon isothermal ageing at 250 °C, the following precipitation sequence was identified for the α-Mg supersaturated solution: β″ (D0{sub 19}) → β′ (bco) → β{sub 1} (fcc) → β (fcc). The observed precipitation process and age hardening response in the Al grain-refined Mg–10Gd–3Y alloy are compared with those reported in the Zr grain-refined counterpart. - Highlights: • The precipitation process in Mg–10Gd–3Y–0.8Al (wt.%) alloy has been investigated. • Particles with the 18R-type LPSO structure were observed in the solution state. • Upon ageing at 250 °C, the precipitation sequence is: β″ → β′ → β1 (fcc) → β. • The Al grain-refined alloy has a lower hardness than the Zr refined counterpart.

  7. Isothermal separation processes update. Energy Conversion and Utilization Technologies Program

    SciTech Connect

    England, C.

    1984-08-01

    The isothermal processes of membrane separation, supercritical extraction and condensed-phase chromatography were examined using availability analysis, a method which addresses the thermodynamic value of energy as well as its amount. The general approach was to derive equations that identified where energy, expressed in terms of thermodynamic work, is consumed in these processes and how they compare with conventional separation methods. These separation methods are characterized by pure work inputs, chiefly in the form of a pressure drop which supplies the required energy. Equations were derived for the energy requirement in terms of the theories of ideal and regular solutions. This approach is believed to accurately predict the work of separation in terms of the heat of solution and the entropy of mixing. It can form the basis of a convenient calculation method for optimizing membrane and solvent properties for particular applications. Close examination of supercritical extraction found a relatively simple thermodynamic relationship among the thermodynamic properties of the solvent, the entropy of mixing, and the heat of solution. This allows a direct estimate of the work requirements. The actual work, however, is largely due to the requirement to cycle pressure at high levels in this method. Still, the energy requirements are very low, making up for usually high capital costs for equipment. 12 references, 9 figures, 2 tables.

  8. Combined heat and mass transfer device for improving separation process

    SciTech Connect

    Tran, Thanh Nhon

    1997-12-01

    A two-phase small channel heat exchange matrix for providing simultaneous heat transfer and mass transfer at a single, predetermined location within a separation column, whereby the thermodynamic efficiency of the separation process is significantly improved. The small channel heat exchange matrix is comprised of a series of channels having a hydraulic diameter no greater than 5.0 mm. The channels are connected to an inlet header for supplying a two-phase coolant to the channels and an outlet header for receiving the coolant horn the channels. In operation, the matrix provides the liquid-vapor contacting surfaces within a separation column, whereby liquid descends along the exterior surfaces of the cooling channels and vapor ascends between adjacent channels within the matrix. Preferably, a perforated and concave sheet connects each channel to an adjacent channel, such that liquid further descends along the concave surfaces of the sheets and the vapor further ascends through the perforations in the sheets. The size and configuration of the small channel heat exchange matrix allows the heat and mass transfer device to be positioned within the separation column, thereby allowing precise control of the local operating conditions within the column and increasing the energy efficiency of the process.

  9. NEST-GENERATION TCAP HYDROGEN ISOTOPE SEPARATION PROCESS

    SciTech Connect

    Heung, L; Henry Sessions, H; Anita Poore, A; William Jacobs, W; Christopher Williams, C

    2007-08-07

    A thermal cycling absorption process (TCAP) for hydrogen isotope separation has been in operation at Savannah River Site since 1994. The process uses a hot/cold nitrogen system to cycle the temperature of the separation column. The hot/cold nitrogen system requires the use of large compressors, heat exchanges, valves and piping that is bulky and maintenance intensive. A new compact thermal cycling (CTC) design has recently been developed. This new design uses liquid nitrogen tubes and electric heaters to heat and cool the column directly so that the bulky hot/cold nitrogen system can be eliminated. This CTC design is simple and is easy to implement, and will be the next generation TCAP system at SRS. A twelve-meter column has been fabricated and installed in the laboratory to demonstrate its performance. The design of the system and its test results to date is discussed.

  10. Countercurrent Process for Lignin Separation from Biomass Matrix

    SciTech Connect

    Kiran Kadam; Ed Lehrburger

    2006-03-31

    The overall goal of the project was to test the concept of using a twin-screw extruder to conduct autohydrolysis pretreatment of wheat straw in countercurrent fashion, demonstrate in situ solid/liquid separation, and produce a low-lignin cellulose product using ethanol as an extractant. The resultant solid product is suitable for sugar production through enzymatic hydrolysis and for pulp applications. Pilot-scale equipment was used to successfully demonstrate the process both for sugar and pulp applications.

  11. COLUMBIC OXIDE ADSORPTION PROCESS FOR SEPARATING URANIUM AND PLUTONIUM IONS

    DOEpatents

    Beaton, R.H.

    1959-07-14

    A process is described for separating plutonium ions from a solution of neutron irradiated uranium in which columbic oxide is used as an adsorbert. According to the invention the plutonium ion is selectively adsorbed by Passing a solution containing the plutonium in a valence state not higher than 4 through a porous bed or column of granules of hydrated columbic oxide. The adsorbed plutonium is then desorbed by elution with 3 N nitric acid.

  12. Assessing Precipitation Isotope Variations during Atmospheric River Events to Reveal Dominant Atmospheric/Hydrologic Processes

    NASA Astrophysics Data System (ADS)

    McCabe-Glynn, S. E.; Johnson, K. R.; Yoshimura, K.; Buenning, N. H.; Welker, J. M.

    2015-12-01

    Extreme precipitation events across the Western US commonly associated with atmospheric rivers (ARs), whereby extensive fluxes of moisture are transported from the subtropics, can result in major damage and are projected by most climate models to increase in frequency and severity. However, they are difficult to project beyond ~ten days and the location of landfall and topographically induced precipitation is even more uncertain. Water isotopes, often used to reconstruct past rainfall variability, are useful natural tracers of atmospheric hydrologic processes. Because of the typical tropical and sub-tropical origins, ARs can carry unique water isotope (δ18O and δ2H, d-excess) signatures that can be utilized to provide source and process information that can lead to improving AR predictions. Recent analysis of the top 10 weekly precipitation total samples from Sequoia National Park, CA, of which 9 contained AR events, shows a high variability in the isotopic values. NOAA Hysplit back trajectory analyses reveals a variety of trajectories and varying latitudinal source regions contributed to moisture delivered to this site, which may explain part of the high variability (δ2H = -150.03 to -49.52 ‰, δ18O = -19.27 to -7.20 ‰, d-excess = 4.1 to 25.8). Here we examine the top precipitation totals occurring during AR events and the associated isotopic composition of precipitation samples from several sites across the Western US. We utilize IsoGSM, an isotope-enabled atmospheric general circulation model, to characterize the hydrologic processes and physical dynamics contributing to the observed isotopic variations. We investigate isotopic influences from moisture source location, AR speed, condensation height, and associated temperature. We explore the dominant controls on spatial and temporal variations of the isotopic composition of AR precipitation which highlights different physical processes for different AR events.

  13. SEPARATION OF AMERICIUM FROM PROMETHIUM

    DOEpatents

    Pressly, R.E.

    1959-07-01

    Promethium-147 is separated from americium in acidic aqueous solution by adding fluosilicic acid to the solution, heating the solution to form a promethium precipitate and separating the precipitate from solution. The precipitate is then re-dissolved by ihe addition of boric acid and nitric acid, and re-precipitated by the addition of fluosilicic acid. This procedure is repeated six or more times to obtain a relatively americium-free promeihium precipitate. Americium may be separately recovered from the supernatant liquids. This process is applicable to the recovery of promethium from fission-product solutions which have been allowed to decay for a period of two to four years.

  14. Removing tannins from medicinal plant extracts using an alkaline ethanol precipitation process: a case study of Danshen injection.

    PubMed

    Gong, Xingchu; Li, Yao; Qu, Haibin

    2014-01-01

    The alkaline ethanol precipitation process is investigated as an example of a technique for the removal of tannins extracted from Salviae miltiorrhizae Radix et Rhizoma for the manufacture of Danshen injection. More than 90% of the tannins can be removed. However, the recoveries of danshensu, rosmarinic acid, and salvianolic acid B were less than 60%. Total tannin removal increased as the refrigeration temperature decreased or the amount of NaOH solution added increased. Phenolic compound recoveries increased as refrigeration temperature increased or the amount of NaOH solution added decreased. When operated at a low refrigeration temperature, a relative high separation selectivity can be realized. Phenolic compound losses and tannin removal were mainly caused by precipitation. The formation of phenol salts, whose solubility is small in the mixture of ethanol and water used, is probably the reason for the precipitation. A model considering dissociation equilibrium and dissolution equilibrium was established. Satisfactory correlation results were obtained for phenolic compound recoveries and total tannin removal. Two important parameters in the model, which are the water content and pH value of alkaline supernatant, are suggested to be monitored and controlled to obtain high batch-to-batch consistency.

  15. A stepwise recovery of metals from hybrid cathodes of spent Li-ion batteries with leaching-flotation-precipitation process

    NASA Astrophysics Data System (ADS)

    Huang, Yanfang; Han, Guihong; Liu, Jiongtian; Chai, Wencui; Wang, Wenjuan; Yang, Shuzhen; Su, Shengpeng

    2016-09-01

    The recovering of valuable metals in spent lithium-ion battery cathodes brings about economic and environmental benefits. A stepwise leaching-flotation-precipitation process is adopted to separate and recover Li/Fe/Mn from the mixed types of cathode materials (hybrid wastes of LiFePO4 and LiMn2O4). The optimal operating conditions for the stepwise recovery process are determined and analyzed by factorial design, thermodynamics calculation, XRD and SEM characterization in this study. First, Li/Fe/Mn ions are released from the cathode using HCl assisted with H2O2 in the acid leaching step. The leachability of metals follows the series Li > Fe > Mn in the acidic environment. Then Fe3+ ions are selectively floated and recovered as FeCl3 from the leachate in the flotation step. Finally, Mn2+/Mn3+ and Li+ ions are sequentially precipitated and separated as MnO2/Mn2O3 and Li3PO4 using saturated KMnO4 solution and hot saturated Na3PO4 solution, respectively. Under the optimized and advisable conditions, the total recovery of Li, Fe and Mn is respectively 80.93 ± 0.16%, 85.40 ± 0.12% and 81.02 ± 0.08%. The purity for lithium, ferrum and manganese compounds is respectively 99.32 ± 0.07%, 97.91 ± 0.05% and 98.73 ± 0.05%. This stepwise process could provide an alternative way for the effective separation and recovery of metal values from spent Li-ion battery cathodes in industry.

  16. Economics of recombinant antibody production processes at various scales: Industry-standard compared to continuous precipitation.

    PubMed

    Hammerschmidt, Nikolaus; Tscheliessnig, Anne; Sommer, Ralf; Helk, Bernhard; Jungbauer, Alois

    2014-06-01

    Standard industry processes for recombinant antibody production employ protein A affinity chromatography in combination with other chromatography steps and ultra-/diafiltration. This study compares a generic antibody production process with a recently developed purification process based on a series of selective precipitation steps. The new process makes two of the usual three chromatographic steps obsolete and can be performed in a continuous fashion. Cost of Goods (CoGs) analyses were done for: (i) a generic chromatography-based antibody standard purification; (ii) the continuous precipitation-based purification process coupled to a continuous perfusion production system; and (iii) a hybrid process, coupling the continuous purification process to an upstream batch process. The results of this economic analysis show that the precipitation-based process offers cost reductions at all stages of the life cycle of a therapeutic antibody, (i.e. clinical phase I, II and III, as well as full commercial production). The savings in clinical phase production are largely attributed to the fact that expensive chromatographic resins are omitted. These economic analyses will help to determine the strategies that are best suited for small-scale production in parallel fashion, which is of importance for antibody production in non-privileged countries and for personalized medicine.

  17. Nitrogen Trifluoride-Based Fluoride- Volatility Separations Process: Initial Studies

    SciTech Connect

    McNamara, Bruce K.; Scheele, Randall D.; Casella, Andrew M.; Kozelisky, Anne E.

    2011-09-28

    This document describes the results of our investigations on the potential use of nitrogen trifluoride as the fluorinating and oxidizing agent in fluoride volatility-based used nuclear fuel reprocessing. The conceptual process uses differences in reaction temperatures between nitrogen trifluoride and fuel constituents that produce volatile fluorides to achieve separations and recover valuable constituents. We provide results from our thermodynamic evaluations, thermo-analytical experiments, kinetic models, and provide a preliminary process flowsheet. The evaluations found that nitrogen trifluoride can effectively produce volatile fluorides at different temperatures dependent on the fuel constituent.

  18. Understanding runoff processes in a semi-arid environment through isotope and hydrochemical hydrograph separations

    NASA Astrophysics Data System (ADS)

    Camacho, V. V.; Saraiva Okello, A. M. L.; Wenninger, J. W.; Uhlenbrook, S.

    2015-01-01

    The understanding of runoff generation mechanisms is crucial for the sustainable management of river basins such as the allocation of water resources or the prediction of floods and droughts. However, identifying the mechanisms of runoff generation has been a challenging task, even more so in arid and semi-arid areas where high rainfall and streamflow variability, high evaporation rates, and deep groundwater reservoirs increase the complexity of hydrological process dynamics. Isotope and hydrochemical tracers have proven to be useful in identifying runoff components and their characteristics. Moreover, although widely used in humid-temperate regions, isotope hydrograph separations have not been studied in detail in arid and semi-arid areas. Thus the purpose of this study is to determine if isotope hydrograph separations are suitable for the quantification and characterization of runoff components in a semi-arid catchment considering the hydrological complexities of these regions. Through a hydrochemical characterization of the surface water and groundwater sources of the catchment and two and three component hydrograph separations, runoff components of the Kaap Catchment in South Africa were quantified using both, isotope and hydrochemical tracers. No major disadvantages while using isotope tracers over hydrochemical tracers were found. Hydrograph separation results showed that runoff in the Kaap catchment is mainly generated by groundwater sources. Two-component hydrograph separations revealed groundwater contributions between 64 and 98% of total runoff. By means of three-component hydrograph separations, runoff components were further separated into direct runoff, shallow and deep groundwater components. Direct runoff, defined as the direct precipitation on the stream channel and overland flow, contributed up to 41% of total runoff during wet catchment conditions. Shallow groundwater defined as the soil water and near-surface water component, contributed up to 45

  19. Understanding runoff processes in a semi-arid environment through isotope and hydrochemical hydrograph separations

    NASA Astrophysics Data System (ADS)

    Camacho Suarez, V. V.; Saraiva Okello, A. M. L.; Wenninger, J. W.; Uhlenbrook, S.

    2015-10-01

    The understanding of runoff generation mechanisms is crucial for the sustainable management of river basins such as the allocation of water resources or the prediction of floods and droughts. However, identifying the mechanisms of runoff generation has been a challenging task, even more so in arid and semi-arid areas where high rainfall and streamflow variability, high evaporation rates, and deep groundwater reservoirs may increase the complexity of hydrological process dynamics. Isotope and hydrochemical tracers have proven to be useful in identifying runoff components and their characteristics. Moreover, although widely used in humid temperate regions, isotope hydrograph separations have not been studied in detail in arid and semi-arid areas. Thus the purpose of this study is to determine whether isotope hydrograph separations are suitable for the quantification and characterization of runoff components in a semi-arid catchment considering the hydrological complexities of these regions. Through a hydrochemical characterization of the surface water and groundwater sources of the catchment and two- and three-component hydrograph separations, runoff components of the Kaap catchment in South Africa were quantified using both isotope and hydrochemical tracers. No major disadvantages while using isotope tracers over hydrochemical tracers were found. Hydrograph separation results showed that runoff in the Kaap catchment is mainly generated by groundwater sources. Two-component hydrograph separations revealed groundwater contributions of between 64 and 98 % of total runoff. By means of three-component hydrograph separations, runoff components were further separated into direct runoff, shallow and deep groundwater components. Direct runoff, defined as the direct precipitation on the stream channel and overland flow, contributed up to 41 % of total runoff during wet catchment conditions. Shallow groundwater defined as the soil water and near-surface water component (and

  20. Used nuclear fuel separations process simulation and testing

    SciTech Connect

    Pereira, C.; Krebs, J.F.; Copple, J.M.; Frey, K.E.; Maggos, L.E.; Figueroa, J.; Willit, J.L.; Papadias, D.D.

    2013-07-01

    Recent efforts in separations process simulation at Argonne have expanded from the traditional focus on solvent extraction flowsheet design in order to capture process dynamics and to simulate other components, processing and systems of a used nuclear fuel reprocessing plant. For example, the Argonne Model for Universal Solvent Extraction (AMUSE) code has been enhanced to make it both more portable and more readily extensible. Moving away from a spreadsheet environment makes the addition of new species and processes simpler for the expert user, which should enable more rapid implementation of chemical models that simulate evolving processes. The dyAMUSE (dynamic AMUSE) version allows the simulation of transient behavior across an extractor. Electrochemical separations have now been modeled using spreadsheet codes that simulate the electrochemical recycle of fast reactor fuel. The user can follow the evolution of the salt, products, and waste compositions in the electro-refiner, cathode processors, and drawdown as a function of fuel batches treated. To further expand capabilities in integrating multiple unit operations, a platform for linking mathematical models representing the different operations that comprise a reprocessing facility was adapted to enable systems-level analysis and optimization of facility functions. (authors)

  1. FORMATION PROCESSES AND CONSEQUENCES OF REACTIVE AND NON-REACTIVE MINERAL PRECIPITATES IN PERMEABLE REACTIVE BARRIERS

    EPA Science Inventory

    Mineral precipitates in zero-valent iron PRBs can be classified by formation processes into three groups: 1) those that result from changes in chemical conditions (i.e., change in pH, e.g., calcite); 2) those that are a consequence of microbial activity (i.e., sulfate reduction, ...

  2. Effect of some organic solvent-water mixtures composition on precipitated calcium carbonate in carbonation process

    NASA Astrophysics Data System (ADS)

    Konopacka-Łyskawa, Donata; Kościelska, Barbara; Karczewski, Jakub

    2015-05-01

    Precipitated calcium carbonate particles were obtained during carbonation of calcium hydroxide slurry with carbon dioxide. Aqueous solutions of isopropyl alcohol, n-butanol and glycerol were used as solvents. Concentration of organic additives in the reactive mixture was from 0% to 20% (vol). Precipitation process were performed in a stirred tank reactor equipped with gas distributor. Multimodal courses of particles size distribution were determined for produced CaCO3 particles. Calcium carbonate as calcite was precipitated in all experiments. The mean Sauter diameter of CaCO3 particles decreased when the concentration of all used organic additives increased. The amount of small particle fraction in the product increased with the increasing concentration of organic solvents. Similar physical properties of used liquid phase resulted in the similar characteristics of obtained particles.

  3. Process for separation and preconcentration of radium from water

    DOEpatents

    Dietz, Mark; Horwitz, E. Philip; Chiarizia, Renato; Bartsch, Richard A.

    1999-01-01

    A process for preconcentrating and separating radium from a contaminated solution containing at least water and radium includes the steps of adding a quantity of a water-soluble macrocyclic polyether to the contaminated solution to form a combined solution. An acid is added to the combined solution to form an acidic combined solution having an ›H.sup.+ ! concentration of about 0.5M. The acidic combined solution is contacted with a sulfonic acid-based strong acid cation exchange medium or a organophilic sulfonic acid medium having a plurality of binding sites thereon to bind the radium thereto and to form a radium-depleted solution. The radium-depleted solution is separated from the strong acid cation exchange medium or organophilic sulfonic acid medium. The radium remaining bound to the exchange medium or organophilic reagent is then stripped from the exchange medium or organophilic medium and the activity of the radium is measured.

  4. Process for separation and preconcentration of radium from water

    DOEpatents

    Dietz, M.; Horwitz, E.P.; Chiarizia, R.; Bartsch, R.A.

    1999-01-26

    A process for preconcentrating and separating radium from a contaminated solution containing at least water and radium includes the steps of adding a quantity of a water-soluble macrocyclic polyether to the contaminated solution to form a combined solution. An acid is added to the combined solution to form an acidic combined solution having an [H{sup +}] concentration of about 0.5M. The acidic combined solution is contacted with a sulfonic acid-based strong acid cation exchange medium or a organophilic sulfonic acid medium having a plurality of binding sites thereon to bind the radium thereto and to form a radium-depleted solution. The radium-depleted solution is separated from the strong acid cation exchange medium or organophilic sulfonic acid medium. The radium remaining bound to the exchange medium or organophilic reagent is then stripped from the exchange medium or organophilic medium and the activity of the radium is measured. 24 figs.

  5. Large-scale superconducting separator for Kaolin processing

    SciTech Connect

    Winters, A.J, Jr. ); Selvaggi, J.A. )

    1990-01-01

    Currently, high gradient magnetic separators (HGMSs) are used almost exclusively by the clay processing industry, particularly in producing an extremely white kaolin for the paper, coatings and rubber industries where a bright additive is desirable. As mined, the clay is a light cream color-not white. Many of these impurities can be removed chemically using a reducing agent such as sodium hydrosulfite in low pH, sulfuric acid, and alum. High purity, however, can be obtained by removing trace amounts of paramagnetic particles (100% finer than 2 {mu}m). This is accomplished by separating these particles from 28 wt% kaolin in a water slurry retaining them on magnetic wool, which is then periodically regenerated.

  6. Formation of asymmetrical structured silica controlled by a phase separation process and implication for biosilicification.

    PubMed

    Shi, Jia-Yuan; Yao, Qi-Zhi; Li, Xi-Ming; Zhou, Gen-Tao; Fu, Sheng-Quan

    2013-01-01

    Biogenetic silica displays intricate patterns assembling from nano- to microsize level and interesting non-spherical structures differentiating in specific directions. Several model systems have been proposed to explain the formation of biosilica nanostructures. Of them, phase separation based on the physicochemical properties of organic amines was considered to be responsible for the pattern formation of biosilica. In this paper, using tetraethyl orthosilicate (TEOS, Si(OCH2CH3)4) as silica precursor, phospholipid (PL) and dodecylamine (DA) were introduced to initiate phase separation of organic components and influence silica precipitation. Morphology, structure and composition of the mineralized products were characterized using a range of techniques including field emission scanning electron microscopy (FESEM), transmission electron microscope (TEM), X-ray diffraction (XRD), thermogravimetric and differential thermal analysis (TG-DTA), infrared spectra (IR), and nitrogen physisorption. The results demonstrate that the phase separation process of the organic components leads to the formation of asymmetrically non-spherical silica structures, and the aspect ratios of the asymmetrical structures can be well controlled by varying the concentration of PL and DA. On the basis of the time-dependent experiments, a tentative mechanism is also proposed to illustrate the asymmetrical morphogenesis. Therefore, our results imply that in addition to explaining the hierarchical porous nanopatterning of biosilica, the phase separation process may also be responsible for the growth differentiation of siliceous structures in specific directions. Because organic amine (e.g., long-chair polyamines), phospholipids (e.g., silicalemma) and the phase separation process are associated with the biosilicification of diatoms, our results may provide a new insight into the mechanism of biosilicification.

  7. Formation of Asymmetrical Structured Silica Controlled by a Phase Separation Process and Implication for Biosilicification

    PubMed Central

    Shi, Jia-Yuan; Yao, Qi-Zhi; Li, Xi-Ming; Zhou, Gen-Tao; Fu, Sheng-Quan

    2013-01-01

    Biogenetic silica displays intricate patterns assembling from nano- to microsize level and interesting non-spherical structures differentiating in specific directions. Several model systems have been proposed to explain the formation of biosilica nanostructures. Of them, phase separation based on the physicochemical properties of organic amines was considered to be responsible for the pattern formation of biosilica. In this paper, using tetraethyl orthosilicate (TEOS, Si(OCH2CH3)4) as silica precursor, phospholipid (PL) and dodecylamine (DA) were introduced to initiate phase separation of organic components and influence silica precipitation. Morphology, structure and composition of the mineralized products were characterized using a range of techniques including field emission scanning electron microscopy (FESEM), transmission electron microscope (TEM), X-ray diffraction (XRD), thermogravimetric and differential thermal analysis (TG-DTA), infrared spectra (IR), and nitrogen physisorption. The results demonstrate that the phase separation process of the organic components leads to the formation of asymmetrically non-spherical silica structures, and the aspect ratios of the asymmetrical structures can be well controlled by varying the concentration of PL and DA. On the basis of the time-dependent experiments, a tentative mechanism is also proposed to illustrate the asymmetrical morphogenesis. Therefore, our results imply that in addition to explaining the hierarchical porous nanopatterning of biosilica, the phase separation process may also be responsible for the growth differentiation of siliceous structures in specific directions. Because organic amine (e.g., long-chair polyamines), phospholipids (e.g., silicalemma) and the phase separation process are associated with the biosilicification of diatoms, our results may provide a new insight into the mechanism of biosilicification. PMID:23585878

  8. A Data System Architecture for Measurement Based Systems: Precipitation Processing System

    NASA Technical Reports Server (NTRS)

    Stocker, Erich Franz

    2003-01-01

    NASA s Earth Science Enterprise (ESE) is changing focus from single satellite missions to measurement oriented programs. An example of this paradigm shift is the Global Precipitation Measurement (GPM) project. GPM is conceptualized as a rolling-wave of measurement possibilities all focused on the key precipitation parameter. In response to this shift to measurement programs and also integral to the ESE s new strategy for processing and management its data, a measurement based approach is also critical for data processing system that support measurement programs like GPM. This paper provides an overview of the paradigm shift from mission to measurement. It also presents a summary of the ESE s new strategy for its data systems. Building on this background the paper details the architectural, design and implementation aspects of the Precipitation Processing System (PPS). The PPS is an evolution of a single point system developed for the Tropical Rainfall Measurement Mission to a generic precipitation data system. The paper provides the context within which PPS will support the GPM program.

  9. Heavy Oil Process Monitor: Automated On-Column Asphaltene Precipitation and Re-Dissolution

    SciTech Connect

    John F. Schabron; Joseph F. Rovani; Mark Sanderson

    2007-03-31

    An automated separation technique was developed that provides a new approach to measuring the distribution profiles of the most polar, or asphaltenic components of an oil, using a continuous flow system to precipitate and re-dissolve asphaltenes from the oil. Methods of analysis based on this new technique were explored. One method based on the new technique involves precipitation of a portion of residua sample in heptane on a polytetrafluoroethylene-packed (PTFE) column. The precipitated material is re-dissolved in three steps using solvents of increasing polarity: cyclohexane, toluene, and methylene chloride. The amount of asphaltenes that dissolve in cyclohexane is a useful diagnostic of the thermal history of oil, and its proximity to coke formation. For example, about 40 % (w/w) of the heptane asphaltenes from unpyrolyzed residua dissolves in cyclohexane. As pyrolysis progresses, this number decrease to below 15% as coke and toluene insoluble pre-coke materials appear. Currently, the procedure for the isolation of heptane asphaltenes and the determination of the amount of asphaltenes soluble in cyclohexane spans three days. The automated procedure takes one hour. Another method uses a single solvent, methylene chloride, to re-dissolve the material that precipitates on heptane on the PTFE-packed column. The area of this second peak can be used to calculate a value which correlates with gravimetric asphaltene content. Currently the gravimetric procedure to determine asphaltenes takes about 24 hours. The automated procedure takes 30 minutes. Results for four series of original and pyrolyzed residua were compared with data from the gravimetric methods. Methods based on the new on-column precipitation and re-dissolution technique provide significantly more detail about the polar constituent's oils than the gravimetric determination of asphaltenes.

  10. Bone marrow processing on the Haemonetics V50 cell separator.

    PubMed

    Anderson, N A; Cornish, J M; Godwin, V; Gunstone, M J; Oakhill, A; Pamphilon, D H

    1990-01-01

    We have processed 27 bone marrow (BM) harvests using the Haemonetics V50 cell separator with a paediatric plasmapheresis set and programmed for lymphocyte collection. The mean starting volume of 843 mL was processed in 6-8 cycles to a buffy coat (BC) with a mean volume of 230 mL. The mean starting mononuclear cell (MNC) count was 1.22 x 10 8/kg recipient weight, and recovery was 92%. Clonogenic potential of the BC was assessed using CFU-GM assays and recovery was measured after cryopreservation or purging. On 4 occasions where major ABO incompatibility existed between donor and recipient, both BM and BC were consecutively diluted in compatible blood and processed twice. This achieved a calculated reduction in donor erythrocytes of 98%. The procedure was efficient and yielded a BC fraction suitable for cryopreservation and purging. Adequate stem-cells were retained as verified by CFU-GM assays and documentation of stable engraftment.

  11. Process for the separation of components from gas mixtures

    DOEpatents

    Merriman, J.R.; Pashley, J.H.; Stephenson, M.J.; Dunthorn, D.I.

    1973-10-01

    A process for the removal, from gaseous mixtures of a desired component selected from oxygen, iodine, methyl iodide, and lower oxides of carbon, nitrogen, and sulfur is described. The gaseous mixture is contacted with a liquid fluorocarbon in an absorption zone maintained at superatmospheric pressure to preferentially absorb the desired component in the fluorocarbon. Unabsorbed constituents of the gaseous mixture are withdrawn from the absorption zone. Liquid fluorocarbon enriched in the desired component is withdrawn separately from the zone, following which the desired component is recovered from the fluorocarbon absorbent. (Official Gazette)

  12. Synthesis of crystallization-distillation hybrid separation processes

    SciTech Connect

    Berry, D.A.; Ng, K.M.

    1997-07-01

    A systematic method to synthesize crystallization-distillation hybrid separation processes is presented. Two classes of hybrids are identified for binary mixtures. The first bypasses azeotropes and tangent pinches, while the second bypasses eutectics. Guidelines for flow-sheet selection are proposed based on an analysis of simple eutectic, constant relative volatility systems. In addition, the hybrids are compared to both extractive and adductive crystallization in order to determine the conditions under which solvent-based crystallization techniques outperform the proposed hybrid configurations. The method is extended to ternary mixture. The use of stream combination and complex distillation columns is also considered.

  13. SEPARATION PROCESS FOR TRANSURANIC ELEMENT AND COMPOUNDS THEREOF

    DOEpatents

    Calvin, M.

    1958-10-14

    S> A process is presented for the separation of pluto nium from uranium and fission products in an aqueous acidic solution by use of a chelating agent. The plutonium is maintained in the tetravalent state and the uranium in the hexavalent state, and the acidic concentration is adjusted to about 1 N bar. The aqueous solution is then contacted with a water-immiscible organic solvent solution and the chelating agent. The chelating agents covered by this invention comprise a group of compounds characterized as fluorinated beta-diketones.

  14. Combined heat and mass transfer device for improving separation process

    DOEpatents

    Tran, Thanh Nhon

    1999-01-01

    A two-phase small channel heat exchange matrix simultaneously provides for heat transfer and mass transfer between the liquid and vapor phases of a multi-component mixture at a single, predetermined location within a separation column, significantly improving the thermodynamic efficiency of the separation process. The small channel heat exchange matrix is composed of a series of channels having a hydraulic diameter no greater than 5.0 millimeters for conducting a two-phase coolant. In operation, the matrix provides the liquid-vapor contacting surfaces within the separation column, such that heat and mass are transferred simultaneously between the liquid and vapor phases. The two-phase coolant allows for a uniform heat transfer coefficient to be maintained along the length of the channels and across the surface of the matrix. Preferably, a perforated, concave sheet connects each channel to an adjacent channel to facilitate the flow of the liquid and vapor phases within the column and to increase the liquid-vapor contacting surface area.

  15. Combined heat and mass transfer device for improving separation process

    DOEpatents

    Tran, T.N.

    1999-08-24

    A two-phase small channel heat exchange matrix simultaneously provides for heat transfer and mass transfer between the liquid and vapor phases of a multi-component mixture at a single, predetermined location within a separation column, significantly improving the thermodynamic efficiency of the separation process. The small channel heat exchange matrix is composed of a series of channels having a hydraulic diameter no greater than 5.0 millimeters for conducting a two-phase coolant. In operation, the matrix provides the liquid-vapor contacting surfaces within the separation column, such that heat and mass are transferred simultaneously between the liquid and vapor phases. The two-phase coolant allows for a uniform heat transfer coefficient to be maintained along the length of the channels and across the surface of the matrix. Preferably, a perforated, concave sheet connects each channel to an adjacent channel to facilitate the flow of the liquid and vapor phases within the column and to increase the liquid-vapor contacting surface area. 12 figs.

  16. Citrate based ``TALSPEAK`` lanthanide-actinide separation process

    SciTech Connect

    Del Cul, G.D.; Bond, W.D.; Toth, L.M.; Davis, G.D.; Dai, S.; Metcalf, D.H.

    1994-09-01

    The potential hazard posed to future generations by long-lived radionuclides such as the transuranic elements (TRU) is perceived as a major problem associated with the use of nuclear power. TRU wastes have to remain isolated from the environment for ``geological`` periods of time. The costs of building, maintaining, and operating a ``geological TRU repository`` can be very high. Therefore, there are significant economical advantages in segregating the relatively low volume of TRU wastes from other nuclear wastes. The chemical behavior of lanthanides and actinides, 4f and 5f elements respectively, is rather similar. As a consequence, the separation of these two groups is difficult. The ``TALSPEAK`` process (Trivalent Actinide Lanthanide Separations by Phosphorus-reagent Extraction from Aqueous Complexes) is one of the few means available to separate the trivalent actinides from the lanthanides. The method is based on the preferential complexation of the trivalent actinides by an aminopolyacetic acid. Cold experiments showed that by using citric acid the deleterious effects produced by impurities such as zirconium are greatly reduced.

  17. Separate neural processing of timbre dimensions in auditory sensory memory.

    PubMed

    Caclin, Anne; Brattico, Elvira; Tervaniemi, Mari; Näätänen, Risto; Morlet, Dominique; Giard, Marie-Hélène; McAdams, Stephen

    2006-12-01

    Timbre is a multidimensional perceptual attribute of complex tones that characterizes the identity of a sound source. Our study explores the representation in auditory sensory memory of three timbre dimensions (acoustically related to attack time, spectral centroid, and spectrum fine structure), using the mismatch negativity (MMN) component of the auditory event-related potential. MMN is elicited by a discriminable change in a sound sequence and reflects the detection of the discrepancy between the current stimulus and traces in auditory sensory memory. The stimuli used in the present study were carefully controlled synthetic tones. MMNs were recorded after changes along each of the three timbre dimensions and their combinations. Additivity of unidimensional MMNs and dipole modeling results suggest partially separate MMN generators for different timbre dimensions, reflecting their mainly separate processing in auditory sensory memory. The results expand to timbre dimensions a property of separation of the representation in sensory memory that has already been reported between basic perceptual attributes (pitch, loudness, duration, and location) of sound sources.

  18. X-band radar field campaign data analysis for orographic/warm-rain precipitation processes

    NASA Astrophysics Data System (ADS)

    Porcacchia, Leonardo; Kirstetter, Pierre-Emmanuel; Gourley, Jonathan J.; Anagnostou, Marios N.; Anagnostou, Emmanouil N.; Bousquet, Olivier; Cheong, Boon-Leng; Maggioni, Viviana; Hong, Yang

    2016-04-01

    Accurate quantitative precipitation estimation over mountainous basins is of great importance because of their susceptibility to hazards such as flash floods, shallow landslides, and debris flows. It is usually hard to obtain reliable weather radar information in mountainous areas, due to difficulties connected to non-meteorological scattering and the elevation of the study sites. Such regions are particularly interested by orographic/warm-rain precipitation processes, characterized by no ice phase in the cloud and prevailing concentration of small drops in the drop size distribution. Field campaigns are able to provide complete and solid datasets in mountainous regions, thanks to mobile radars and the complementary information provided by rain gauges and disdrometers. This study analyzes datasets collected during the Hymex, IPHEX, and Colorado field campaigns in mountainous areas in Italy, France, North Carolina, and Colorado. Mobile X-band radars from the NOAA National Severe Storm Laboratory and the Advanced Radar Research Center at the University of Oklahoma are utilized. The X-band dual polarimetric radar data are corrected for attenuation through the SCOP algorithm, and evaluated against disdrometer and rain-gauge data. Warm-rain events are identified by looking at the Gorgucci, Cao-Zhang, and Kumjian-Ryzhkov parameter spaces relating polarimetric radar variables to precipitation development processes in the cloud and rain size distributions. A conceptual model for the vertical profile of precipitation and microphysical structure of the cloud is also derived, to be contrasted against other typical convective and stratiform profiles.

  19. The Goddard Cumulus Ensemble Model (GCE): Improvements and Applications for Studying Precipitation Processes

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo; Lang, Stephen E.; Zeng, Xiping; Li, Xiaowen; Matsui, Toshi; Mohr, Karen; Posselt, Derek; Chern, Jiundar; Peters-Lidard, Christa; Norris, Peter M.; Kang, In-Sik; Choi, Ildae; Hou, Arthur; Lau, K.-M.; Yang, Young-Min

    2014-01-01

    Convection is the primary transport process in the Earth's atmosphere. About two-thirds of the Earth's rainfall and severe floods derive from convection. In addition, two-thirds of the global rain falls in the tropics, while the associated latent heat release accounts for three-fourths of the total heat energy for the Earth's atmosphere. Cloud-resolving models (CRMs) have been used to improve our understanding of cloud and precipitation processes and phenomena from micro-scale to cloud-scale and mesoscale as well as their interactions with radiation and surface processes. CRMs use sophisticated and realistic representations of cloud microphysical processes and can reasonably well resolve the time evolution, structure, and life cycles of clouds and cloud systems. CRMs also allow for explicit interaction between clouds, outgoing longwave (cooling) and incoming solar (heating) radiation, and ocean and land surface processes. Observations are required to initialize CRMs and to validate their results. The Goddard Cumulus Ensemble model (GCE) has been developed and improved at NASA/Goddard Space Flight Center over the past three decades. It is amulti-dimensional non-hydrostatic CRM that can simulate clouds and cloud systems in different environments. Early improvements and testing were presented in Tao and Simpson (1993) and Tao et al. (2003a). A review on the application of the GCE to the understanding of precipitation processes can be found in Simpson and Tao (1993) and Tao (2003). In this paper, recent model improvements (microphysics, radiation and land surface processes) are described along with their impact and performance on cloud and precipitation events in different geographic locations via comparisons with observations. In addition, recent advanced applications of the GCE are presented that include understanding the physical processes responsible for diurnal variation, examining the impact of aerosols (cloud condensation nuclei or CCN and ice nuclei or IN) on

  20. DISSOLUTION OF LANTHANUM FLUORIDE PRECIPITATES

    DOEpatents

    Fries, B.A.

    1959-11-10

    A plutonium separatory ore concentration procedure involving the use of a fluoride type of carrier is presented. An improvement is given in the derivation step in the process for plutonium recovery by carrier precipitation of plutonium values from solution with a lanthanum fluoride carrier precipitate and subsequent derivation from the resulting plutonium bearing carrier precipitate of an aqueous acidic plutonium-containing solution. The carrier precipitate is contacted with a concentrated aqueous solution of potassium carbonate to effect dissolution therein of at least a part of the precipitate, including the plutonium values. Any remaining precipitate is separated from the resulting solution and dissolves in an aqueous solution containing at least 20% by weight of potassium carbonate. The reacting solutions are combined, and an alkali metal hydroxide added to a concentration of at least 2N to precipitate lanthanum hydroxide concomitantly carrying plutonium values.

  1. Separation and Fixation of Toxic Components in Salt Brines Using a Water-Based Process

    SciTech Connect

    Franks, C.; Quach, A.; Birnie III, D.; Ela, W.; Saez, A.E.; Zelinski, B.; Smith, H.; Smith, G.

    2004-01-01

    Efforts to implement new water quality standards, increase water reuse and reclamation, and minimize the cost of waste storage motivate the development of new processes for stabilizing wastewater residuals that minimize waste volume, water content and the long-term environmental risk from related by-products. This work explores the use of an aqueous-based emulsion process to create an epoxy/rubber matrix for separating and encapsulating waste components from salt laden, arsenic contaminated, amorphous iron hydrate sludges. Such sludges are generated from conventional water purification precipitation/adsorption processes, used to convert aqueous brine streams to semi-solid waste streams, such as ion exchange/membrane separation, and from other precipitative heavy metal removal operations. In this study, epoxy and polystyrene butadiene (PSB) rubber emulsions are mixed together and then combined with a surrogate sludge. The surrogate sludge consists of amorphous iron hydrate with 1 part arsenic fixed to the surface of the hydrate per 10 parts iron mixed with sodium nitrate and chloride salts and water. The resulting emulsion is cured and dried at 80 °C to remove water. Microstructure characterization by electron microscopy confirms that the epoxy/PSB matrix surrounds and encapsulates the arsenic laden amorphous iron hydrate phase while allowing the salt to migrate to internal and external surfaces of the sample. Salt extraction studies indicate that the porous nature of the resulting matrix promotes the separation and removal of as much as 90% of the original salt content in only one hour. Long term leaching studies based on the use of the infinite slab diffusion model reveal no evidence of iron migration or, by inference, arsenic migration, and demonstrate that the diffusion coefficients of the unextracted salt yield leachability indices within regulations for non-hazardous landfill disposal. Because salt is the most mobile species, it is inferred that arsenic

  2. Evaluating shallow convective mixing and precipitation processes using isotope ratios in water vapor

    NASA Astrophysics Data System (ADS)

    Raudzens Bailey, Adriana

    Water vapor and clouds both respond to and influence global temperature. Consequently, understanding the processes that control humidity patterns and cloudiness is key for predicting future climate accurately. To elucidate the physical processes controlling water cycle feedbacks in the subtropics, this thesis applies new observational techniques to evaluate moisture and pollutant transport between the Hawaiian boundary layer--near ocean surface--and the dry free troposphere above. Beginning with a case study, paired measurements of humidity and the ratio of heavy-to-light oxygen isotopes in vapor are used to characterize vertical moisture transport as a simple mixing process. Strong mixing events are found to shape moisture transport for multiple days at a time, highlighting the need to understand which factors control the strength of convective mixing. Large-scale dynamical controls on convective mixing near Hawaii are subsequently evaluated, and the relative importance of large-scale transport and microphysical processes in modifying humidity and pollutant distributions is investigated. Based on isotopic theory, strong convective events are classified as having either high or low precipitation efficiency. While the latter are associated with a branching of the subtropical jet, which facilitates advection of relatively high concentrations of methane and ozone from Eurasia, the former are associated with tropical plumes that transport relatively clean and moist air. Particle number concentrations, in comparison, exhibit clear sensitivity to the precipitation processes associated with convection, with higher precipitation efficiency events resulting in scavenging of pre-existing aerosol that, in turn, appears to facilitate new particle formation at higher altitudes. To determine whether the resultant variations in vertical distributions of moisture and pollutants influence cloud fields, isotopic retrievals from satellite are used to define precipitation efficiency

  3. Evaluating Cloud and Precipitation Processes in Numerical Models using Current and Potential Future Satellite Missions

    NASA Astrophysics Data System (ADS)

    van den Heever, S. C.; Tao, W. K.; Skofronick Jackson, G.; Tanelli, S.; L'Ecuyer, T. S.; Petersen, W. A.; Kummerow, C. D.

    2014-12-01

    Cloud, aerosol and precipitation processes play a fundamental role in the water and energy cycle. It is critical to accurately represent these microphysical processes in numerical models if we are to better predict cloud and precipitation properties on weather through climate timescales. Much has been learned about cloud properties and precipitation characteristics from NASA satellite missions such as TRMM, CloudSat, and more recently GPM. Furthermore, data from these missions have been successfully utilized in evaluating the microphysical schemes in cloud-resolving models (CRMs) and global models. However, there are still many uncertainties associated with these microphysics schemes. These uncertainties can be attributed, at least in part, to the fact that microphysical processes cannot be directly observed or measured, but instead have to be inferred from those cloud properties that can be measured. Evaluation of microphysical parameterizations are becoming increasingly important as enhanced computational capabilities are facilitating the use of more sophisticated schemes in CRMs, and as future global models are being run on what has traditionally been regarded as cloud-resolving scales using CRM microphysical schemes. In this talk we will demonstrate how TRMM, CloudSat and GPM data have been used to evaluate different aspects of current CRM microphysical schemes, providing examples of where these approaches have been successful. We will also highlight CRM microphysical processes that have not been well evaluated and suggest approaches for addressing such issues. Finally, we will introduce a potential NASA satellite mission, the Cloud and Precipitation Processes Mission (CAPPM), which would facilitate the development and evaluation of different microphysical-dynamical feedbacks in numerical models.

  4. Evaluating Cloud and Precipitation Processes in Numerical Models using Current and Potential Future Satellite Missions

    NASA Astrophysics Data System (ADS)

    van den Heever, S. C.; Tao, W. K.; Skofronick Jackson, G.; Tanelli, S.; L'Ecuyer, T. S.; Petersen, W. A.; Kummerow, C. D.

    2015-12-01

    Cloud, aerosol and precipitation processes play a fundamental role in the water and energy cycle. It is critical to accurately represent these microphysical processes in numerical models if we are to better predict cloud and precipitation properties on weather through climate timescales. Much has been learned about cloud properties and precipitation characteristics from NASA satellite missions such as TRMM, CloudSat, and more recently GPM. Furthermore, data from these missions have been successfully utilized in evaluating the microphysical schemes in cloud-resolving models (CRMs) and global models. However, there are still many uncertainties associated with these microphysics schemes. These uncertainties can be attributed, at least in part, to the fact that microphysical processes cannot be directly observed or measured, but instead have to be inferred from those cloud properties that can be measured. Evaluation of microphysical parameterizations are becoming increasingly important as enhanced computational capabilities are facilitating the use of more sophisticated schemes in CRMs, and as future global models are being run on what has traditionally been regarded as cloud-resolving scales using CRM microphysical schemes. In this talk we will demonstrate how TRMM, CloudSat and GPM data have been used to evaluate different aspects of current CRM microphysical schemes, providing examples of where these approaches have been successful. We will also highlight CRM microphysical processes that have not been well evaluated and suggest approaches for addressing such issues. Finally, we will introduce a potential NASA satellite mission, the Cloud and Precipitation Processes Mission (CAPPM), which would facilitate the development and evaluation of different microphysical-dynamical feedbacks in numerical models.

  5. Using Multi-Scale Modeling Systems to Study the Precipitation Processes

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo

    2010-01-01

    In recent years, exponentially increasing computer power has extended Cloud Resolving Model (CRM) integrations from hours to months, the number of computational grid points from less than a thousand to close to ten million. Three-dimensional models are now more prevalent. Much attention is devoted to precipitating cloud systems where the crucial 1-km scales are resolved in horizontal domains as large as 10,000 km in two-dimensions, and 1,000 x 1,000 km2 in three-dimensions. Cloud resolving models now provide statistical information useful for developing more realistic physically based parameterizations for climate models and numerical weather prediction models. It is also expected that NWP and mesoscale model can be run in grid size similar to cloud resolving model through nesting technique. Recently, a multi-scale modeling system with unified physics was developed at NASA Goddard. It consists of (1) a cloud-resolving model (Goddard Cumulus Ensemble model, GCE model), (2) a regional scale model (a NASA unified weather research and forecast, WRF), (3) a coupled CRM and global model (Goddard Multi-scale Modeling Framework, MMF), and (4) a land modeling system. The same microphysical processes, long and short wave radiative transfer and land processes and the explicit cloud-radiation, and cloud-land surface interactive processes are applied in this multi-scale modeling system. This modeling system has been coupled with a multi-satellite simulator to use NASA high-resolution satellite data to identify the strengths and weaknesses of cloud and precipitation processes simulated by the model. In this talk, a review of developments and applications of the multi-scale modeling system will be presented. In particular, the results from using multi-scale modeling system to study the interactions between clouds, precipitation, and aerosols will be presented. Also how to use of the multi-satellite simulator to improve precipitation processes will be discussed.

  6. Using Multi-Scale Modeling Systems and Satellite Data to Study the Precipitation Processes

    NASA Technical Reports Server (NTRS)

    Tao, Wei--Kuo; Chern, J.; Lamg, S.; Matsui, T.; Shen, B.; Zeng, X.; Shi, R.

    2010-01-01

    In recent years, exponentially increasing computer power extended Cloud Resolving Model (CRM) integrations from hours to months, the number of computational grid points from less than a thousand to close to ten million. Three-dimensional models are now more prevalent. Much attention is devoted to precipitating cloud systems where the crucial 1-km scales are resolved in horizontal domains as large as 10,000 km in two-dimensions, and 1,000 x 1,000 sq km in three-dimensions. Cloud resolving models now provide statistical information useful for developing more realistic physically based parameterizations for climate models and numerical weather prediction models. It is also expected that NWP and mesoscale models can be run in grid size similar to cloud resolving models through nesting technique. Recently, a multi-scale modeling system with unified physics was developed at NASA Goddard. It consists of (1) a cloud-resolving model (Goddard Cumulus Ensemble model, GCE model). (2) a regional scale model (a NASA unified weather research and forecast, W8F). (3) a coupled CRM and global model (Goddard Multi-scale Modeling Framework, MMF), and (4) a land modeling system. The same microphysical processes, long and short wave radiative transfer and land processes and the explicit cloud-radiation and cloud-land surface interactive processes are applied in this multi-scale modeling system. This modeling system has been coupled with a multi-satellite simulator to use NASA high-resolution satellite data to identify the strengths and weaknesses of cloud and precipitation processes simulated by the model. In this talk, a review of developments and applications of the multi-scale modeling system will be presented. In particular, the results from using multi-scale modeling systems to study the interactions between clouds, precipitation, and aerosols will be presented. Also how to use the multi-satellite simulator to improve precipitation processes will be discussed.

  7. An isotope dilution-precipitation process for removing radioactive cesium from wastewater.

    PubMed

    Rogers, Harold; Bowers, John; Gates-Anderson, Dianne

    2012-12-01

    A novel isotope dilution-precipitation method has been developed to remove cesium-137 from radioactive wastewater. The process involves adding stable cesium chloride to wastewater in order to raise the total cesium concentration, which then allows both the stable and radioactive cesium ions to be precipitated together using sodium tetraphenylborate. This process was investigated utilizing laboratory solutions to determine stable cesium dose rates, mixing times, effects of pH, and filtration requirements. Once optimized, the process was then tested on synthetic wastewater and aqueous low-level waste. Experiments showed the reaction to be very quick and stable in the pH range tested, 2.5-11.5. The wastewater may need to be filtered using a 0.45-μm filter, though ferric sulfate has been shown to promote coagulation and settling, thereby eliminating the necessity for filtration. This investigation showed that this isotope dilution-precipitation process can remove Cs-37 levels below the U.S. Department of Energy's (DOE) Derived Concentration Standard (DCS) of 3.0 × 10(-6) μCi/mL using a single dosage, potentially allowing the wastewater to be discharged directly to sanitary sewers.

  8. Development of an Automated Precipitation Processing Model and Applications in Hydrologic Investigations

    NASA Astrophysics Data System (ADS)

    Milewski, A. M.; Markondiah Jayaprakash, S.; Sultan, M.; Becker, R.

    2006-12-01

    Given the advances in new technologies, more and more scientists are beginning to utilize remote sensing or satellite imagery in their research applications. Remote sensing data offer a synoptic view and observational quantitative parameters over large domains and thus provide cost-effective solutions by reducing the labor involved in collecting extensive field observations. One of the valuable data sets that can be extracted from remote sensing observations is precipitation. Prior to the deployment of the relevant satellite-based sensors, users had to resort to rainfall stations to obtain precipitation data. Currently, users can freely download digital Tropical Rainfall Measuring Mission (TRMM) and Special Spectral Measuring Imager (SSM/I) precipitation data, however, the process of data extraction is not user friendly as it requires computer programming to fully utilize these datasets. We have developed the Automated Precipitation Processing Module (APPM) to simplify the tedious manual process needed to retrieve rainfall estimates via satellite measurements. The function of the APPM is to process the TRMM and SSM/I data according to the user's spatial and temporal inputs. Using APPM, we processed all available TRMM and SSM/I data for six continents (processed data is available on six compact discs: one/continent: refer to www.esrs.wmich.edu). The input data includes global SSM/I (1987-1998) and TRMM (1998-2005) covering an area extending from 50 degrees North to 50 degrees South. Advantages of using our software include: (1) user friendly technology, (2) reduction in processing time (e.g., processing of the entire TRMM & SSM/I dataset (1987-2005) for Africa was reduced from one year to one week), and (3) reduction in required computer resources (original TRMM & SSM/I data: 1.5 terabytes; processed: 300 megabytes). The APPM reads raw binary data and allows for: (1) sub-setting global dataset given user-defined boundaries (latitude and longitude), (2) selection of

  9. Treatment of effluents arising from a material characterization laboratory, using chemical precipitation and reverse osmosis processes

    SciTech Connect

    Bello, S.M.G.; Mierzwa, J.C.

    1995-11-01

    Owing to the restrictions imposed by the Regulations, mainly in the field of effluent release into a water body, it`s necessary to use a set of technologies that will help meeting the standards established by these regulations. Taking into account what was exposed above, a process for treating the effluents arising from a Material Characterization Laboratory, that will characterize nuclear materials is proposed in this paper. The process proposed uses chemical precipitation for removing chemicals which can be removed by this means (Chromium, Calcium and Sulfate for instance), and reverse osmosis process to purify the filtrate from precipitation process. The reverse osmosis process is used to remove dissolved chemicals (Nitrates and Chlorides). A synthetic solution with a COD of 8000 mg/l was used to simulate the treatment process. After treatment was finished, a purified stream, which represents 90 % of the intake stream have presented a COD of less then 10 mg/l, showing that this process can be utilized to minimize the impact caused to the environment. The characterization of all streams involved in the treatment process as well as the process description is presented in this paper.

  10. Process study and exergy analysis of a novel air separation process cooled by LNG cold energy

    NASA Astrophysics Data System (ADS)

    Xu, Wendong; Duan, Jiao; Mao, Wenjun

    2014-02-01

    In order to resolve the problems of the current air separation process such as the complex process, cumbersome operation and high operating costs, a novel air separation process cooled by LNG cold energy is proposed in this paper, which is based on high-efficiency heat exchanger network and chemical packing separation technology. The operating temperature range of LNG cold energy is widened from 133K-203K to 113K-283K by high-efficiency heat exchanger network and air separation pressure is declined from 0.5MPa to about 0.35MPa due to packing separation technology, thereby greatly improve the energy efficiency. Both the traditional and novel air separation processes are simulated with air handling capacity of 20t·h-1. Comparing with the traditional process, the LNG consumption is reduced by 44.2%, power consumption decrease is 211.5 kWh per hour, which means the annual benefit will be up to 1.218 million CNY. And the exergy efficiency is also improved by 42.5%.

  11. Microstructure, Precipitation, and Mechanical Properties of V-N-Alloyed Steel After Different Cooling Processes

    NASA Astrophysics Data System (ADS)

    Zhang, Jing; Wang, Fu-Ming; Yang, Zhan-Bing; Li, Chang-Rong

    2016-09-01

    Three cooling processes (direct air cooling, water cooling to 1023 K and 873 K (750 °C and 600 °C) followed by air cooling) after hot rolling are designed to develop V-N-alloyed 600 MPa grade high-strength steel for architectural construction. Microstructural characteristics, precipitation behavior, and mechanical properties were investigated. Experimental results indicate that all microstructures are composed of polygonal ferrite and pearlite. Compared to the microstructure obtained from traditional direct air cooling, the grain size of ferrite is refined from 6.5 to 4.6 μm and the interlamellar spacing of pearlite decreases from 136 to 45 nm, respectively, by the application of accelerated cooling and lower finish cooling temperature. The number fraction of high misorientation angle boundaries increases from 44 to 51 pct. Moreover, the sheet spacing of interphase precipitates decreases from (23 to 26 nm) to (14 to 17 nm) and the size of V(C,N) particles reduces from (5 to 8 nm) to (2 to 5 nm). Furthermore, the optimal mechanical properties are obtained in the steel water cooled to 873 K (600 °C), of which the yield strength, tensile strength, total elongation, uniform elongation, and impact energy at room temperature are 753 MPa, 922 MPa, 22 pct, 11 pct, and 36 J, respectively. Besides, the high yield strength is primarily attributed to the refined grains and precipitation hardening from interphase and random precipitation of nano-scale V(C,N) particles.

  12. The Doubting Process: A Longitudinal Study of the Precipitants and Consequences of Religious Doubt

    PubMed Central

    Krause, Neal; Ellison, Christopher G.

    2010-01-01

    Religious doubt arises from a process in which there is a precipitant, the experience of doubt, a coping response, and a health-related outcome. We explore this process by assessing whether social factors precipitate doubt and the coping responses that are invoked to deal with it. Moreover, we evaluate whether these coping responses are, in turn, associated with health. The data reveal that, over time, people who encounter more negative interaction with fellow congregants have more doubts about religion, whereas more spiritual support and greater involvement in prayer groups are associated with less religious doubt. The findings further indicate that people who encounter more negative interaction are more likely to suppress religious doubts, but people who attend Bible study groups are more likely to seek spiritual growth when faced with doubt. Finally, the results suggest that suppressing religious doubt is associated with less favorable health, whereas seeking spiritual growth does not have a significant effect. PMID:20300487

  13. Engineering evaluation of neutralization and precipitation processes applicable to sludge treatment project

    SciTech Connect

    Klem, M.J.

    1998-08-25

    Engineering evaluations have been performed to determine likely unit operations and methods required to support the removal, storage, treatment and disposal of solids/sludges present in the K Basins at the Hanford Site. This evaluation was initiated to select a neutralization process for dissolver product solution resulting from nitric acid treatment of about 50 m{sup 3} of Hanford Site K Basins sludge. Neutralization is required to meet Tank Waste Remediation Waste System acceptance criteria for storage of the waste in the double shell tanks after neutralization, the supernate and precipitate will be transferred to the high level waste storage tanks in 200E Area. Non transuranic (TRU) solids residue will be transferred to the Environmental Restoration Disposal Facility (ERDF). This report presents an overview of neutralization and precipitation methods previously used and tested. This report also recommends a neutralization process to be used as part of the K Basins Sludge Treatment Project and identifies additional operations requiring further evaluation.

  14. Overview of the PRECP (PRocessing of Emissions by Clouds and Precipitation) Program

    SciTech Connect

    Hales, J.M.

    1988-02-01

    The PRocessing of Emissions by Clouds and Precipitation (PRECP) Program addresses the scientific understanding and quantitative description of the physical and chemical storm processes that lead to deposition of pollutants to the earth's surface. These processes are primary determinants of source-receptor transport distances and of the chemical forms, concentrations, and wet-deposition loadings of pollutants at receptor sites. The importance of each of these features to NAPAP, both for policy analysis and for input to scientific studies of receptor response, are largely self-evident. A brief description of the program is presented.

  15. Study of benzene release from Savannah River in-tank precipitation process slurry simulant

    SciTech Connect

    Rappe, K.G.; Gauglitz, P.A.

    1998-08-01

    At the Savannah River Site, the in-tank precipitation (ITP) process uses sodium tetraphenylborate (NaTPB) to precipitate radioactive cesium from alkaline wastes. During this process, potassium is also precipitated to form 4-wt% KTPB/CsTPB slurry. Residual NaTPB decomposes to form benzene, which is retained by the waste slurry. The retained benzene is also readily released from the waste during subsequent waste processing. While the release of benzene certainly poses flammability and toxicological safety concerns, the magnitude of the hazard depends on the rate of release. Currently, the mechanisms controlling the benzene release rates are not well understood, and predictive models for estimating benzene release rates are not available. The overall purpose of this study is to obtain quantitative measurements of benzene release rates from a series of ITP slurry simulants. This information will become a basis for developing a quantitative mechanistic model of benzene release rates. The transient benzene release rate was measured from the surface of various ITP slurry (solution) samples mixed with benzene. The benzene release rate was determined by continuously purging the headspace of a sealed sample vessel with an inert gas (nitrogen) and analyzing that purged headspace vapor for benzene every minute.

  16. Recovery of ammonia in digestates of calf manure through a struvite precipitation process using unconventional reagents.

    PubMed

    Siciliano, A; De Rosa, S

    2014-01-01

    Land spreading of digestates causes the discharge of large quantities of nutrients into the environment, which contributes to eutrophication and depletion of dissolved oxygen in water bodies. For the removal of ammonia nitrogen, there is increasing interest in the chemical precipitation of struvite, which is a mineral that can be reused as a slow-release fertilizer. However, this process is an expensive treatment of digestate because large amounts of magnesium and phosphorus reagents are required. In this paper, a struvite precipitation-based process is proposed for an efficient recovery of digestate nutrients using low-cost reagents. In particular, seawater bittern, a by-product of marine salt manufacturing and bone meal, a by-product of the thermal treatment of meat waste, have been used as low-cost sources of magnesium and phosphorus, respectively. Once the operating conditions are defined, the process enables the removal of more than 90% ammonia load, the almost complete recovery of magnesium and phosphorus and the production of a potentially valuable precipitate containing struvite crystals.

  17. Synthesis of nano precipitated calcium carbonate by using a carbonation process through a closed loop reactor

    NASA Astrophysics Data System (ADS)

    Thriveni, Thenepalli; Ahn, Ji Whan; Ramakrishna, Chilakala; Ahn, Young Jun; Han, Choon

    2016-01-01

    Nano calcium carbonate particles have a wide range of industrial applications due to their beneficial properties such as high porosity and high surface area to volume ratio and due to their strengthening the mechanical properties of plastics and paper. Consequently, significant research has been done to deliver a new approach for the synthesis of precipitated nano calcium carbonate by using a carbonation process through a closed loop reactor. Both the experimental and the instrumental parameters, i.e. the CO2 flow rate, the concentration of the starting materials (Ca(OH)2 and CaO), the pH, the orifice diameter, etc., were investigated. The carbonation efficiency was increased due to the diffusion process involved in the loop reactor. The particle size was affected by the CO2 flow rate, reaction time, and orifice diameter. Finally, precipitated nano calcite calcium carbonate (50 to 100 nm) was synthesized by optimizing all the experimental and the instrumental parameters. The synthesized precipitated nano calcium carbonate was characterized by using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy. This study has proved that the carbonation efficiency can be enhanced for a short time by using a loop reactor and that the carbonation process was more energy efficient and cost effective than other conventional methods.

  18. Polymeric membrane and process for separation of aliphatically unsaturated hydrocarbons

    SciTech Connect

    Ho, W.S.W.

    1991-11-05

    This patent describes a process for separating at least one unsaturated hydrocarbon from a hydrocarbon feed steam containing the unsaturated hydrocarbon. It comprises contacting the feed stream against a first side of a solid, homogeneous membrane comprising a hydrophilic polymer selected from the group consisting of a polyvinylalcohol, polyvinylacetate, sulfonyl-containing polymers, polyvinylpyrrolidone, polyethylene oxide, polyacrylamide, copolymers thereof, and blends thereof a transition metal or transition metal ion capable of reversibly complexing with the unsaturated hydrocarbon, and a hydrophilic salt of a Group I metal; and withdrawing at a second side of the membrane a permeate comprising the unsaturated hydrocarbon in higher concentration than in the feed stream. This patent also describes a solid, homogeneous membrane for separating at least one unsaturated hydrocarbon from a hydrocarbon stream containing the unsaturated hydrocarbon. It comprises a hydrophilic polymer selected from the group consisting of polyvinylalcohol, polyvinylacetate, sulfonyl-containing polymers, polyvinylpyrrolidone, polyethylene oxide, polyacrylamide, copolymers thereof, and blends thereof, a transition metal or transition metal ion capable of reversibly complexing with the unsaturated hydrocarbon, and a hydrophilic salt of a Group I metal.

  19. The Impact of Aerosols on Cloud and Precipitation Processes: Cloud-Resolving Model Simulations

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo; Li, Xiaowen; Khain, Alexander; Matsui, Toshihisa; Lang, Stephen; Simpson, Joanne

    2008-01-01

    Aerosols and especially their effect on clouds are one of the key components of the climate system and the hydrological cycle [Ramanathan et al., 2001]. Yet, the aerosol effect on clouds remains largely unknown and the processes involved not well understood. A recent report published by the National Academy of Science states "The greatest uncertainty about the aerosol climate forcing - indeed, the largest of all the uncertainties about global climate forcing - is probably the indirect effect of aerosols on clouds [NRC, 2001]." The aerosol effect on clouds is often categorized into the traditional "first indirect (i.e., Twomey)" effect on the cloud droplet sizes for a constant liquid water path [Twomey, 1977] and the "semi-direct" effect on cloud coverage [e.g., Ackerman et al ., 2001]." Enhanced aerosol concentrations can also suppress warm rain processes by producing a narrow droplet spectrum that inhibits collision and coalescence processes [e.g., Squires and Twomey, 1961; Warner and Twomey, 1967; Warner, 1968; Rosenfeld, 19991. The aerosol effect on precipitation processes, also known as the second type of aerosol indirect effect [Albrecht, 1989], is even more complex, especially for mixed-phase convective clouds. Table 1 summarizes the key observational studies identifying the microphysical properties, cloud characteristics, thermodynamics and dynamics associated with cloud systems from high-aerosol continental environments. For example, atmospheric aerosol concentrations can influence cloud droplet size distributions, warm-rain process, cold-rain process, cloud-top height, the depth of the mixed phase region, and occurrence of lightning. In addition, high aerosol concentrations in urban environments could affect precipitation variability by providing an enhanced source of cloud condensation nuclei (CCN). Hypotheses have been developed to explain the effect of urban regions on convection and precipitation [van den Heever and Cotton, 2007 and Shepherd, 2005

  20. Using Multi-Scale Modeling Systems and Satellite Data to Study the Precipitation Processes

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo; Chern, J.; Lamg, S.; Matsui, T.; Shen, B.; Zeng, X.; Shi, R.

    2011-01-01

    In recent years, exponentially increasing computer power has extended Cloud Resolving Model (CRM) integrations from hours to months, the number of computational grid points from less than a thousand to close to ten million. Three-dimensional models are now more prevalent. Much attention is devoted to precipitating cloud systems where the crucial 1-km scales are resolved in horizontal domains as large as 10,000 km in two-dimensions, and 1,000 x 1,000 km2 in three-dimensions. Cloud resolving models now provide statistical information useful for developing more realistic physically based parameterizations for climate models and numerical weather prediction models. It is also expected that NWP and mesoscale model can be run in grid size similar to cloud resolving model through nesting technique. Recently, a multi-scale modeling system with unified physics was developed at NASA Goddard. It consists of (l) a cloud-resolving model (Goddard Cumulus Ensemble model, GCE model), (2) a regional scale model (a NASA unified weather research and forecast, WRF), (3) a coupled CRM and global model (Goddard Multi-scale Modeling Framework, MMF), and (4) a land modeling system. The same microphysical processes, long and short wave radiative transfer and land processes and the explicit cloud-radiation, and cloud-land surface interactive processes are applied in this multi-scale modeling system. This modeling system has been coupled with a multi-satellite simulator to use NASA high-resolution satellite data to identify the strengths and weaknesses of cloud and precipitation processes simulated by the model. In this talk, the recent developments and applications of the multi-scale modeling system will be presented. In particular, the results from using multi-scale modeling system to study the precipitating systems and hurricanes/typhoons will be presented. The high-resolution spatial and temporal visualization will be utilized to show the evolution of precipitation processes. Also how to

  1. Polymeric membrane and process for separating aliphatically unsaturated hydrocarbons

    SciTech Connect

    Ho, W.S.W.

    1991-05-14

    This patent describes a process for separating at least one unsaturated hydrocarbon from a hydrocarbon feed stream containing. It comprises: contacting the feed stream against a first side of a solid, homogeneous membrane consisting essentially of a hydrophilic polymer selected from the group consisting of polyvinylalcohol, polyvinylacetate, sulfonyl containing polymers, polyvinylpyrrolidone, polyethylene oxide, polyacrylamide, copolymers thereof, and blends thereof, and a metal or metal ion capable of reversibly complexing with the unsaturated hydrocarbon, the metal or metal ion is distributed homogeneously in the hydrophilic polymer; and withdrawing at a second side of the membrane a permeate comprising the unsaturated hydrocarbon in higher concentration than in the feed stream; whereby the membrane provides high permeability and selectivity for unsaturated hydrocarbons and substantially increases the rate at which the permeate is withdrawn.

  2. Tools for efficient design of multicomponent separation processes

    NASA Astrophysics Data System (ADS)

    Huff, Joshua Lee

    formulation and the relative effect of capital and operating cost is weighed for an example feed. Previous methods based on Underwood's equations have no accounting for the temperature at which utilities are required. To account for this, a thermodynamic efficiency function is developed which allows the complete search space to be ranklisted in order of the exergy loss occurring within the configuration. Examining these results shows that this objective function favors configurations which move their reboiler and condenser duties to milder temperature exchangers. A graphical interface is presented which allows interpretation of any of the above results in a quick and intuitive fashion, complete with system flow and composition data and the ability to filter the complete search space based on numerical and structural criteria. This provides a unique way to compare and contrast configurations as well as allowing considerations like column retrofit and maximum controllability to be considered. Using all five of these screening techniques, the traditional intuition-based methods of separations process design can be augmented with analytical and algorithmic tools which enable selection of a process design with low cost and high efficiency.

  3. Process for separating carbon dioxide from flue gas using sweep-based membrane separation and absorption steps

    DOEpatents

    Wijmans, Johannes G.; Baker, Richard W.; Merkel, Timothy C.

    2012-08-21

    A gas separation process for treating flue gases from combustion processes, and combustion processes including such gas separation. The invention involves routing a first portion of the flue gas stream to be treated to an absorption-based carbon dioxide capture step, while simultaneously flowing a second portion of the flue gas across the feed side of a membrane, flowing a sweep gas stream, usually air, across the permeate side, then passing the permeate/sweep gas to the combustor.

  4. Mapping the Interplay of ET and Topography on Precipitation Processes in the Eastern Andes

    NASA Astrophysics Data System (ADS)

    Sun, Xiaoming; Barros, Ana

    2015-04-01

    We present recent work toward elucidating the role of evapotranspiration in the hydrometeorology of the eastern Andes Mountains using realistic and quasi-idealized ET withdrawal experiments with WRF at very high resolution (~1 km grid spacing). The results show that evapotranspiration fluxes modulated by landform govern moist processes in the lower troposphere, including cloud formation and precipitation processes that account for daily precipitation amounts as high as 50-70% depending on synoptic conditions and season. Using parsimonious model experiments and observations for the Amazon basin and the Central Andes, we demonstrate that vegetation acts as a "terrestrial hydrostat" regulating precipitation locally by controlling atmospheric moist instability, and remotely through changes in atmospheric transport patterns. References Sun, X., and A. P. Barros, 2014a: Isolating the role of surface evapotranspiration on moist convection along the eastern flanks of the tropical Andes using a quasi-idealized approach. J. Atmos. Sci., 72, 243-261. Sun, X., and A. P. Barros, 2014b: Impact of Amazonian evapotranspiration on moisture transport and convection along the eastern flanks of the Andes. Q. J. R. Meteorol. Soc., In Review.

  5. Decomposition and Precipitation Process During Thermo-mechanical Fatigue of Duplex Stainless Steel

    NASA Astrophysics Data System (ADS)

    Weidner, Anja; Kolmorgen, Roman; Kubena, Ivo; Kulawinski, Dirk; Kruml, Tomas; Biermann, Horst

    2016-05-01

    The so-called 748 K (475 °C) embrittlement is one of the main drawbacks for the application of ferritic-austenitic duplex stainless steels (DSS) at higher temperatures caused by a spinodal decomposition of the ferritic phase. Thermo-mechanical fatigue tests performed on a DSS in the temperature range between 623 K and 873 K (350 °C and 600 °C) revealed no negative influence on the fatigue lifetime. However, an intensive subgrain formation occurred in the ferritic phase, which was accompanied by formation of fine precipitates. In order to study the decomposition process of the ferritic grains due to TMF testing, detailed investigations using scanning and transmission electron microscopy are presented. The nature of the precipitates was determined as the cubic face centered G-phase, which is characterized by an enrichment of Si, Mo, and Ni. Furthermore, the formation of secondary austenite within ferritic grains was observed.

  6. A Family of Poisson Processes for Use in Stochastic Models of Precipitation

    NASA Astrophysics Data System (ADS)

    Penland, C.

    2013-12-01

    Both modified Poisson processes and compound Poisson processes can be relevant to stochastic parameterization of precipitation. This presentation compares the dynamical properties of these systems and discusses the physical situations in which each might be appropriate. If the parameters describing either class of systems originate in hydrodynamics, then proper consideration of stochastic calculus is required during numerical implementation of the parameterization. It is shown here that an improper numerical treatment can have severe implications for estimating rainfall distributions, particularly in the tails of the distributions and, thus, on the frequency of extreme events.

  7. Doubly stochastic Poisson process models for precipitation at fine time-scales

    NASA Astrophysics Data System (ADS)

    Ramesh, Nadarajah I.; Onof, Christian; Xie, Dichao

    2012-09-01

    This paper considers a class of stochastic point process models, based on doubly stochastic Poisson processes, in the modelling of rainfall. We examine the application of this class of models, a neglected alternative to the widely-known Poisson cluster models, in the analysis of fine time-scale rainfall intensity. These models are mainly used to analyse tipping-bucket raingauge data from a single site but an extension to multiple sites is illustrated which reveals the potential of this class of models to study the temporal and spatial variability of precipitation at fine time-scales.

  8. Development and validation of process models for minor actinide separations processes using centrifugal contactors

    SciTech Connect

    Fox, O.D.; Carrott, M.J.; Gaubert, E.; Maher, C.J.; Mason, C.; Taylor, R.J.; Woodhead, D.A.

    2007-07-01

    As any future spent fuel treatment facility is likely to be based on intensified solvent extraction equipment it is important to understand the chemical and mass transfer kinetics of the processes involved. Two candidate minor actinide separations processes have been examined through a programme of modeling and experimental work to illustrate some of the issues to address in turning these technologies in to fully optimized processes suitable for industrialization. (authors)

  9. [Baseflow separation methods in hydrological process research: a review].

    PubMed

    Xu, Lei-Lei; Liu, Jing-Lin; Jin, Chang-Jie; Wang, An-Zhi; Guan, De-Xin; Wu, Jia-Bing; Yuan, Feng-Hui

    2011-11-01

    Baseflow separation research is regarded as one of the most important and difficult issues in hydrology and ecohydrology, but lacked of unified standards in the concepts and methods. This paper introduced the theories of baseflow separation based on the definitions of baseflow components, and analyzed the development course of different baseflow separation methods. Among the methods developed, graph separation method is simple and applicable but arbitrary, balance method accords with hydrological mechanism but is difficult in application, whereas time series separation method and isotopic method can overcome the subjective and arbitrary defects caused by graph separation method, and thus can obtain the baseflow procedure quickly and efficiently. In recent years, hydrological modeling, digital filtering, and isotopic method are the main methods used for baseflow separation.

  10. Effect of grassland vegetation type on the responses of hydrological processes to seasonal precipitation patterns

    NASA Astrophysics Data System (ADS)

    Salve, Rohit; Sudderth, Erika A.; St. Clair, Samuel B.; Torn, Margaret S.

    2011-11-01

    SummaryUnder future climate scenarios, rainfall patterns and species composition in California grasslands are predicted to change, potentially impacting soil-moisture dynamics and ecosystem function. The primary objective of this study was to assess the impact of altered rainfall on soil-moisture dynamics in three annual grassland vegetation types. We monitored seasonal changes in soil moisture under three different rainfall regimes in mesocosms planted with: (1) a mixed forb-grass community, (2) an Avena barbata monoculture, and (3) an Erodium botrys monoculture. We applied watering treatments in pulses, followed by dry periods that are representative of natural rainfall patterns in California annual grasslands. While rainfall was the dominant treatment, its impact on hydrological processes varied over the growing season. Surprisingly, there were only small differences in the hydrologic response among the three vegetation types. We found significant temporal variability in evapotranspiration, seepage, and soil-moisture content. Both Water Use Efficiency (WUE) and Rain Use Efficiency (RUE) decreased as annual precipitation totals increased. Results from this investigation suggest that both precipitation and vegetation have a significant interactive effect on soil-moisture dynamics. When combined, seasonal precipitation and grassland vegetation influence near-surface hydrology in ways that cannot be predicted from manipulation of a single variable.

  11. Novel platform for minimizing cell loss on separation process: Droplet-based magnetically activated cell separator.

    PubMed

    Kim, Youngho; Hong, Su; Lee, Sang Ho; Lee, Kangsun; Yun, Seok; Kang, Yuri; Paek, Kyeong-Kap; Ju, Byeong-Kwon; Kim, Byungkyu

    2007-07-01

    To reduce the problem of cell loss due to adhesion, one of the basic phenomena in microchannel, we proposed the droplet-based magnetically activated cell separator (DMACS). Based on the platform of the DMACS-which consists of permanent magnets, a coverslip with a circle-shaped boundary, and an injection tube-we could collect magnetically (CD45)-labeled (positive) cells with high purity and minimize cell loss due to adhesion. To compare separation efficiency between the MACS and the DMACS, the total number of cells before and after separation with both the separators was counted by flow cytometry. We could find that the number (3241/59 940) of cells lost in the DMACS is much less than that (22 360/59 940) in the MACS while the efficiency of cell separation in the DMACS (96.07%) is almost the same as that in the MACS (96.72%). Practically, with fluorescent images, it was visually confirmed that the statistical data are reliable. From the viability test by using Hoechst 33 342, it was also demonstrated that there was no cell damage on a gas-liquid interface. Conclusively, DMACS will be a powerful tool to separate rare cells and applicable as a separator, key component of lab-on-a-chip.

  12. Aspergillus carbonarius polygalacturonases purified by integrated membrane process and affinity precipitation for apple juice production.

    PubMed

    Nakkeeran, Ekambaram; Umesh-Kumar, Sukumaran; Subramanian, Rangaswamy

    2011-02-01

    Aspergillus carbonarius, when grown by submerged and solid-state fermentation, produces different molecular forms of polygalacturonase (PG; EC 3.2.1.15), among them a 42 kDa PG with a high specific activity of 7000 U/mg protein. When the enzymes were purified by integrated membrane process (IMP) and alginate affinity precipitation (AAP), the two processes concentrated different forms of the enzyme. The AAP process selectively purified and concentrated the high active PG whereas the IMP yielded different PGs and also amylase and protease. Evaluation of the AAP enzyme preparations for apple juice preparation under conditions usually employed commercially demonstrated that the high activity PG did not result in good juice clarity. With IMP processed enzymes, juice yields and clarity were similar to that obtained with commercial PG from A. niger.

  13. Process for the recovery and separation of plastics

    DOEpatents

    Jody, Bassam J.; Daniels, Edward J.; Pomykala Jr., Joseph A.

    2003-07-29

    A method of separating a portion of acrylonitrile-butadiene-styrene (ABS) from a mixture containing ABS and for separating a portion of ABS and polycarbonate (PC) from a mixture of plastics containing ABS and PC is disclosed. The method includes shredding and/or granulating the mixture of plastics containing ABS and PC to provide a selected particle size; sequentially dispersing the shredded mixture of plastics in a series aqueous solutions having different specific gravities and separating the floating fraction until the desired separation is obtained. Surface tension and pH are also variable to be controlled.

  14. A Coupled GCM-Cloud Resolving Modeling System to Study Precipitation Processes

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo; Chern, Jiundar; Atlas, Robert; Peters-Lidard, Christa; Hou, Arthur; Lin, Xin

    2006-01-01

    Recent GEWEX Cloud System Study (GCSS) model comparison projects have indicated that cloud resolving models (CRMs) agree with observations better than traditional single column models in simulating various types of clouds and cloud systems from different geographic locations. Current and future NASA satellite programs can provide cloud, precipitation, aerosol and other data at very fine spatial and temporal scales. It requires a coupled global circulation model (GCM) and cloud-scale model (termed a super-parameterization or multi-scale modeling framework, MMF) to use these satellite data to improve the understanding of the physical processes that are responsible for the variation in global and regional climate and hydrological systems. The use of a GCM will enable global coverage and the use of a CRM will allow for better and more sophisticated physical parameterization. NASA Satellite and field campaign cloud related data sets can provide initial conditions as well as validation for both the MMF and CRMs. Also we have implemented a Land Information System (LIS that includes the CLM and NOAH land surface models into the MMF. The Goddard MMF is based on the 2D Goddard Cumulus Ensemble (GCE) model and the Goddard finite volume general circulation model (fvGCM) This modeling system has been applied and tested its performance for two different climate scenarios, El Nino (1998) and La Nina (1999). The coupled new modeling system produced more realistic propagation and intensity of tropical rainfall systems and intraseasonal oscillations, and diurnal variation of precipitation that are very difficult to forecast using even the state-of-the-art GCMs. In this talk I will present: (1) a brief review on GCE model and its applications on precipitation processes (both Microphysical and land processes) and (2) The Goddard MMF and the Major difference between two existing MMFs (CSU MMF and Goddard MMF) and preliminary results (the comparison with traditional GCMs).

  15. Efficient separations and processing crosscutting program: Develop and test sorbents

    SciTech Connect

    Bray, L.A.

    1995-09-01

    This report summarizes work performed during FY 1995 under the task {open_quotes}Develop and Test Sorbents,{close_quotes} the purpose of which is to develop high-capacity, selective solid extractants to recover cesium, strontium, and technetium from nuclear wastes. This work is being done for the Efficient Separations and Processing Crosscutting Program (ESP), operated by the U.S. Department of Energy`s Office of Environmental Management`s Office of Technology Development. The task is under the direction of staff at Pacific Northwest Laboratory (PNL) with key participation from industrial and university staff at 3M, St. Paul, Minnesota; IBC Advanced Technologies, Inc., American Forks, Utah; AlliedSignal, Inc., Des Plaines, Illinois, and Texas A&M University, College Station, Texas. 3M and IBC are responsible for ligand and membrane technology development; AlliedSignal and Texas A&M are developing sodium titanate powders; and PNL is testing the materials developed by the industry/university team members. Major accomplishments for FY 1995 are summarized in this report.

  16. PROCESS FOR CONTINUOUSLY SEPARATING IRRADIATION PRODUCTS OF THORIUM

    DOEpatents

    Hatch, L.P.; Miles, F.T.; Sheehan, T.V.; Wiswall, R.H.; Heus, R.J.

    1959-07-01

    A method is presented for separating uranium-233 and protactinium from thorium-232 containing compositions which comprises irradiating finely divided particles of said thorium with a neutron flux to form uranium-233 and protactinium, heating the neutron-irradiated composition in a fluorine and hydrogen atmosphere to form volatile fluorides of uranium and protactinium and thereafter separating said volatile fluorides from the thorium.

  17. Integrated Modeling of Aerosol, Cloud, Precipitation and Land Processes at Satellite-Resolved Scales

    NASA Technical Reports Server (NTRS)

    Peters-Lidard, Christa; Tao, Wei-Kuo; Chin, Mian; Braun, Scott; Case, Jonathan; Hou, Arthur; Kumar, Anil; Kumar, Sujay; Lau, William; Matsui, Toshihisa; Miller, Tim; Santanello, Joseph, Jr.; Shi, Jainn; Starr, David; Tao, Qian; Zaitchik, Benjamin

    2012-01-01

    In this talk, I will present recent results from a project led at NASA/GSFC, in collaboration with NASA/MSFC and JHU, focused on the development and application of an observation-driven integrated modeling system that represents aerosol, cloud, precipitation and land processes at satellite-resolved scales. The project, known as the NASA Unified WRF (NU-WRF), is funded by NASA's Modeling and Analysis Program, and leverages prior investments from the Air Force Weather Agency and NASA's Earth Science Technology Office (ESTO). We define "satellite-resolved" scales as being within a typical mesoscale atmospheric modeling grid (roughly 1-25 km), although this work is designed to bridge the continuum between local (microscale), regional (mesoscale) and global (synoptic) processes. NU-WRF is a superset of the standard NCAR Advanced Research WRF model, achieved by fully integrating the GSFC Land Information System (LIS, already coupled to WRF), the WRF/Chem enabled version of the Goddard Chemistry Aerosols Radiation Transport (GOCART) model, the Goddard Satellite Data Simulation Unit (SDSU), and boundary/initial condition preprocessors for MERRA and GEOS-5 into a single software release (with source code available by agreement with NASA/GSFC). I will show examples where the full coupling between aerosol, cloud, precipitation and land processes is critical for predicting local, regional, and global water and energy cycles, including some high-impact phenomena such as floods, hurricanes, mesoscale convective systems, droughts, and monsoons.

  18. Precipitation, deformation and fracture behaviour of a thermomechanically processed nimonic PE 16 superalloy

    NASA Astrophysics Data System (ADS)

    Rao, K. Bhanusankara; Seetharaman, V.; Mannan, S. L.; Rodriguez, P.

    1981-11-01

    Nimonic alloy PE 16 was subjected to a specific thermomechanical processing designed to improve its post-irradiation ductility. The precipitation behaviour of the carbides and the γ'[Ni 3(Al, Ti)] phase at each stage of the thermomechanical treatment was studied with the help of optical and transmission electron microscopy. At the end of this processing, the alloy contained a uniform dispersion of fine and equiaxed TiC particles throughout the matrix, with a relatively small number of M 23C 6 particles precipitated mainly along the grain boundaries. In addition, a uniform dispersion of spherical γ' particles with a duplex size distribution was obtained. Tensile properties of the thermomechanically processed alloy, evaluated at different temperatures, showed a gradual decrease in the strength properties up to 773 K followed by a rapid decline above this temperature. In addition, a ductility trough was noticed at 773 K. An attempt has been made in this paper to correlate the mechanical properties of the alloy with the microstructural features and with the deformation and fracture behaviour observed at different temperatures.

  19. Annual and average estimates of water-budget components based on hydrograph separation and PRISM precipitation for gaged basins in the Appalachian Plateaus Region, 1900-2011

    USGS Publications Warehouse

    Nelms, David L.; Messinger, Terence; McCoy, Kurt J.

    2015-01-01

    As part of the U.S. Geological Survey’s Groundwater Resources Program study of the Appalachian Plateaus aquifers, annual and average estimates of water-budget components based on hydrograph separation and precipitation data from parameter-elevation regressions on independent slopes model (PRISM) were determined at 849 continuous-record streamflow-gaging stations from Mississippi to New York and covered the period of 1900 to 2011. Only complete calendar years (January to December) of streamflow record at each gage were used to determine estimates of base flow, which is that part of streamflow attributed to groundwater discharge; such estimates can serve as a proxy for annual recharge. For each year, estimates of annual base flow, runoff, and base-flow index were determined using computer programs—PART, HYSEP, and BFI—that have automated the separation procedures. These streamflow-hydrograph analysis methods are provided with version 1.0 of the U.S. Geological Survey Groundwater Toolbox, which is a new program that provides graphing, mapping, and analysis capabilities in a Windows environment. Annual values of precipitation were estimated by calculating the average of cell values intercepted by basin boundaries where previously defined in the GAGES–II dataset. Estimates of annual evapotranspiration were then calculated from the difference between precipitation and streamflow.

  20. Annual and average estimates of water-budget components based on hydrograph separation and PRISM precipitation for gaged basins in the Appalachian Plateaus Region, 1900-2011

    USGS Publications Warehouse

    Nelms, David L.; Messinger, Terence; McCoy, Kurt J.

    2015-07-14

    As part of the U.S. Geological Survey’s Groundwater Resources Program study of the Appalachian Plateaus aquifers, annual and average estimates of water-budget components based on hydrograph separation and precipitation data from parameter-elevation regressions on independent slopes model (PRISM) were determined at 849 continuous-record streamflow-gaging stations from Mississippi to New York and covered the period of 1900 to 2011. Only complete calendar years (January to December) of streamflow record at each gage were used to determine estimates of base flow, which is that part of streamflow attributed to groundwater discharge; such estimates can serve as a proxy for annual recharge. For each year, estimates of annual base flow, runoff, and base-flow index were determined using computer programs—PART, HYSEP, and BFI—that have automated the separation procedures. These streamflow-hydrograph analysis methods are provided with version 1.0 of the U.S. Geological Survey Groundwater Toolbox, which is a new program that provides graphing, mapping, and analysis capabilities in a Windows environment. Annual values of precipitation were estimated by calculating the average of cell values intercepted by basin boundaries where previously defined in the GAGES–II dataset. Estimates of annual evapotranspiration were then calculated from the difference between precipitation and streamflow.

  1. Simultaneous measurements of stable water isotopes in near-surface vapor and precipitation to constrain below-cloud processes

    NASA Astrophysics Data System (ADS)

    Graf, Pascal; Sodemann, Harald; Pfahl, Stephan; Schneebeli, Marc; Ventura, Jordi Figueras i.; Leuenberger, Andreas; Grazioli, Jacopo; Raupach, Tim; Berne, Alexis; Wernli, Heini

    2016-04-01

    Present-day observations of stable water isotopes (SWI) in precipitation on monthly time scales are abundant and the processes governing the variation of SWI on these time scales have been investigated by many studies. However, also on much shorter time scales of hours mesoscale meteorological processes lead to significant variations of SWIs, which are important to understand. There are only few studies investigating the variations of SWI on this short time scale, for which, e.g., frontal dynamics, convection and cloud microphysics play an essential role. In particular, the isotopic composition of both near-surface vapor and precipitation is significantly influenced by below-cloud processes that include precipitation evaporation and isotopic exchange between falling precipitation and surrounding vapor. In this study, simultaneous measurements of SWI in near-surface vapor and precipitation with high (sub-hourly) temporal resolution in combination with observational data from radars, disdrometers, radiosondes and standard meteorological instruments are used for a detailed analysis of the relative importance of below-cloud and in-cloud (i.e., precipitation formation) processes during the course of three rain events in Switzerland in spring 2014. Periods are identified when the isotopic composition of near-surface vapor and equilibrium vapor above liquid rain drops agree and when they differ due to either evaporation of precipitation or incomplete equilibration of precipitation with surrounding vapor. These findings are verified by the supporting observational data. In addition, calculations with a simple rain-shaft model fed with observational data are compared to the actual isotopic composition of precipitation. This combination of isotope measurements and model calculations allows us to test the sensitivity of the precipitation isotope signal to rain intensity, drop-size distribution and temperature and humidity profiles.

  2. Interactions in the Geo-Biosphere: Processes of Carbonate Precipitation in Microbial Mats

    NASA Astrophysics Data System (ADS)

    Dupraz, C.; Visscher, P. T.

    2009-12-01

    Microbial communities are situated at the interface between the biosphere, the lithosphere and the hydrosphere. These microbes are key players in the global carbon cycle, where they influence the balance between the organic and inorganic carbon reservoirs. Microbial populations can be organized in microbial mats, which can be defined as organosedimentary biofilms that are dominated by cyanobacteria, and exhibit tight coupling of element cycles. Complex interactions between mat microbes and their surrounding environment can result in the precipitation of carbonate minerals. This process refers as ‘organomineralization sensu lato' (Dupraz et al. in press), which differs from ‘biomineralization’ (e.g., in shells and bones) by lacking genetic control on the mineral product. Organomineralization can be: (1) active, when microbial metabolic reactions are responsible for the precipitation (“biologically-induced” mineralization) or (2) passive, when mineralization within a microbial organic matrix is environmentally driven (e.g., through degassing or desiccation) (“biologically-influenced” mineralization). Studying microbe-mineral interactions is essential to many emerging fields of the biogeoscience, such as the study of life in extreme environments (e.g, deep biosphere), the origin of life, the search for traces of extraterrestrial life or the seek of new carbon sink. This research approach combines sedimentology, biogeochemistry and microbiology. Two tightly coupled components that control carbonate organomineralization s.l.: (1) the alkalinity engine and (2) the extracellular organic matter (EOM), which is ultimately the location of mineral nucleation. Carbonate alkalinity can be altered both by microbial metabolism and environmental factors. In microbial mats, the net accumulation of carbonate minerals often reflect the balance between metabolic activities that consume/produce CO2 and/or organic acids. For example, photosynthesis and sulfate reduction

  3. Microstructure and Mechanical Behavior of 17-4 Precipitation Hardenable Steel Processed by Selective Laser Melting

    NASA Astrophysics Data System (ADS)

    Rafi, H. Khalid; Pal, Deepankar; Patil, Nachiket; Starr, Thomas L.; Stucker, Brent E.

    2014-12-01

    The mechanical behavior and the microstructural evolution of 17-4 precipitation hardenable (PH) stainless steel processed using selective laser melting have been studied. Test coupons were produced from 17-4 PH stainless steel powder in argon and nitrogen atmospheres. Characterization studies were carried out using mechanical testing, optical microscopy, scanning electron microscopy, and x-ray diffraction. The results show that post-process heat treatment is required to obtain typically desired tensile properties. Columnar grains of smaller diameters (<2 µm) emerged within the melt pool with a mixture of martensite and retained austenite phases. It was found that the phase content of the samples is greatly influenced by the powder chemistry, processing environment, and grain diameter.

  4. A potential DSD retrieval process for dual-frequency precipitation radar (DPR) on board GPM

    NASA Astrophysics Data System (ADS)

    Le, Minda; Chandresekar, V.

    2012-11-01

    Global Precipitation Measurement (GPM) is poised to be the next generation precipitation monitoring system from space after the Tropical rainfall measurement (TRMM) mission. The GPM mission is centered on the deployment of a core observatory satellite with an active dual-frequency radar DPR, operating at Ku- and Ka- band. Two independent observations from DPR provide the possibility to retrieve two independent parameters from gamma drop size distribution (DSD), namely median volume diameter (D0) and scaled intercept (NW), at each resolution volume. Dual-frequency method proposed for the DPR radar can be formulated in terms of integral equations and the two DSD parameters D0 and NW can be estimated at each bin based on the assumed microphysical models of hydrometeors. One known error in the dual frequency retrievals is the dual-valued problem when retrieving D0 from DFR for rain. Rose and Chandrasekar (2006)[1], remedied the bi-valued problem by assuming a linear model with height for D0 as well as NW (in log scale) in rain. The algorithm with the linear assumption was evaluated by Le et al. (2009) [2] based on the whole vertical profile including rain, melting ice, and ice region through a hybrid method. The hybrid method combines forward retrieval by Meneghini et al (1997) [3] in frozen and melting region and the linear assumption in rain region. The retrieval process uses recursive procedure to optimize DSD parameters at the bottom of rain by constructing the cost function along the vertical profile. This retrieval algorithm is applied to tropical storm Earl, a category 4 hurricane captured by APR-2 precipitation radar during the Genesis and Rapid Intensification Processes (GRIP) campaign in 2010.

  5. Layer-by-layer modification of high surface curvature nanoparticles with weak polyelectrolytes using a multiphase solvent precipitation process.

    PubMed

    Nagaraja, Ashvin T; You, Yil-Hwan; Choi, Jeong-Wan; Hwang, Jin-Ha; Meissner, Kenith E; McShane, Michael J

    2016-03-15

    The layer-by-layer modification of ≈5 nm mercaptocarboxylic acid stabilized gold nanoparticles was studied in an effort to illustrate effective means to overcome practical issues in handling and performing surface modification of such extremely small materials. To accomplish this, each layer deposition cycle was separated into a multi-step process wherein solution pH was controlled in two distinct phases of polyelectrolyte adsorption and centrifugation. Additionally, a solvent precipitation step was introduced to make processing more amenable by concentrating the sample and exchanging solution pH before ultracentrifugation. The pH-dependent assembly on gold nanoparticles was assessed after each layer deposition cycle by monitoring the plasmon peak absorbance location, surface charge, and the percentage of nanoparticles recovered. The selection of solution pH during the adsorption phase was found to be a critical parameter to enhance particle recovery and maximize surface charge when coating with weak polyelectrolytes. One bilayer was deposited with a high yield and the modified particles exhibited enhanced colloidal stability across a broad pH range and increased ionic strength. These findings support the adoption of this multi-step processing approach as an effective and generalizable approach to improve stability of high surface curvature particles. PMID:26771506

  6. Multiscale Precipitation Processes Over Mountain Terrain - Landform and Vegetation Controls of Microphysics and Convection in Complex Terrain

    NASA Astrophysics Data System (ADS)

    Barros, A. P.; Wilson, A. M.; Sun, X.; Duan, Y.

    2015-12-01

    Recent precipitation observations in mountainous regions do not exhibit the classical orographic enhancement with elevation, especially where fog and multi-layer clouds are persistent. The role of landform in modulating moisture convergence patterns and constraining the thermodynamic environment that supports the development of complex vertical structures of clouds and precipitation is discussed first using observations and model results from the IPHEx (Integrated Precipitation and Hydrology Experiment) field campaign in the Southern Appalachian Mountains (SAM). Analysis of the complex spatial heterogeneity of precipitation microphysics in the SAM suggests that seeder-feeder interactions (SFI) among stratiform precipitation, low level clouds (LLC), and fog play a governing role on the diurnal and seasonal cycles of observed precipitation regimes. Further, in the absence of synoptic-scale forcing, results suggest that evapotranspiration makes a significant contribution to the moisture budget in the lower atmosphere, creating super-saturation conditions favorable to CCN activation, LLC formation, and light rainfall. To investigate the role of evapotranspiration on the diurnal cycle of mountain precipitation further, range-scale modeling studies were conducted in the Central Andes. Specifically, high resolution WRF simulations for realistic and quasi-idealized ET withdrawal case-studies show that evapotranspiration fluxes modulated by landform govern convective activity in the lower troposphere, including cloud formation and precipitation processes that account for daily precipitation amounts as high as 50-70% depending on synoptic conditions and season. These studies suggest multiscale vegetation controls of orographic precipitation processes via atmospheric instability on the one hand, and low level super-saturation and local microphysics on the other. A conceptual model of multiscale interactions among vegetation, landform and moist processes over complex

  7. Effectiveness of coagulation and acid precipitation processes for the pre-treatment of diluted black liquor.

    PubMed

    Garg, Anurag; Mishra, I M; Chand, S

    2010-08-15

    The effectiveness of coagulation (using aluminium-based chemicals and ferrous sulfate) and acid precipitation (using H(2)SO(4)) processes for the pre-treatment of diluted black liquor obtained from a pulp and paper mill is reported. Commercial alum was found to be the most economical among all the aluminium and ferrous salts used as a coagulant. A maximum removal of chemical oxygen demand (COD) (ca. 63%) and colour reduction (ca. 90%) from the wastewater (COD = 7000 mg l(-1)) at pH 5.0 was obtained with alum. During the acid precipitation process, at pH < 5.0, significant COD reductions (up to 64%) were observed. Solid residue obtained from the alum treatment at a temperature of 95 degrees C showed much better (3 times) settling rate than that for the residue obtained after treatment with the same coagulant at a temperature of 25 degrees C. The settling curves had three parts, namely, hindered, transition and compression zones. Tory plots were used to determine the critical height of suspension-supernatant interface that is used in the design of a clarifier-thickener unit. High heating values and large biomass fraction of the solid residues can encourage the fuel users to use this waste derived sludge as a potential renewable energy source.

  8. Cloud processes of the main precipitation systems in Brazil- CHUVA Project

    NASA Astrophysics Data System (ADS)

    Angelis, C. F.; Sakuragi, J.; Vila, D. A.; Carvalho, I.; Schneebeli, M.

    2011-12-01

    The project CHUVA (Cloud processes of the main precipitation systems in Brazil: A contribution to cloud resolving modeling and to the GPM) is been carrying and its main goal is understand the physical processes involved on the precipitating systems which occur over Brazil. The project plans the setting up of a series of instruments in different parts of Brazil and so far many instruments had been deployed over the three field campaigns. Among the instruments, a dual polarization X band radar, two micro rain radars, a multi-channel ground radiometer, disdrometers, pluviometers are the more important equipments used to collect rainfall information from both: warn and cold clouds. Preliminary results show evident differences in some cloud microphysics observed in different rain events during the campaigns. Besides, rainfall maps produced by the radar data were compared to those similar maps produced by satellite. The X band radar radome, when wet, imposed some attenuation on the radar reflectivities values and an algorithm to compensate such attenuation had been developed based on data observed by disdrometers and micro rain radars. The preliminary results will be shown during the conference and it is expected that the community could discuss and evaluate them under the light of the GPM purposes.

  9. SULFIDE METHOD PLUTONIUM SEPARATION

    DOEpatents

    Duffield, R.B.

    1958-08-12

    A process is described for the recovery of plutonium from neutron irradiated uranium solutions. Such a solution is first treated with a soluble sullide, causing precipitation of the plutoniunn and uraniunn values present, along with those impurities which form insoluble sulfides. The precipitate is then treated with a solution of carbonate ions, which will dissolve the uranium and plutonium present while the fission product sulfides remain unaffected. After separation from the residue, this solution may then be treated by any of the usual methods, such as formation of a lanthanum fluoride precipitate, to effect separation of plutoniunn from uranium.

  10. SALICYLATE PROCESS FOR THORIUM SEPARATION FROM RARE EARTHS

    DOEpatents

    Cowan, G.A.

    1959-08-25

    The separation of thorium from rare earths is accomplished by forming an aqueous solution of salts of thorium and rare earths and sufficient acetate buffer to provide a pH of between 2 and 5, adding an ammonium salicylate to the aqueous buffered solution, contacting the resultant solution with a substantially water-immiscible organic solvent mixture of an ether and an ester, and separating the solvent extract phase containing thorium salicylate from the aqueous phase containing the rare earths.

  11. Volatile fluoride process for separating plutonium from other materials

    DOEpatents

    Spedding, F. H.; Newton, A. S.

    1959-04-14

    The separation of plutonium from uranium and/or fission products by formation of the higher fluorides off uranium and/or plutonium is described. Neutronirradiated uranium metal is first converted to the hydride. This hydrided product is then treated with fluorine at about 315 deg C to form and volatilize UF/sub 6/ leaving plutonium behind. Thc plutonium may then be separated by reacting the residue with fluorine at about 5004DEC and collecting the volatile plutonium fluoride thus formed.

  12. VOLATILE FLUORIDE PROCESS FOR SEPARATING PLUTONIUM FROM OTHER MATERIALS

    DOEpatents

    Spedding, F.H.; Newton, A.S.

    1959-04-14

    The separation of plutonium from uranium and/or tission products by formation of the higher fluorides of uranium and/or plutonium is discussed. Neutronirradiated uranium metal is first convcrted to the hydride. This hydrided product is then treatced with fluorine at about 315 deg C to form and volatilize UF/sup 6/ leaving plutonium behind. The plutonium may then be separated by reacting the residue with fluorine at about 500 deg C and collecting the volatile plutonium fluoride thus formed.

  13. Studying Precipitation Processes in WRF with Goddard Bulk Microphysics in Comparison with Other Microphysical Schemes

    NASA Technical Reports Server (NTRS)

    Tao, W.K.; Shi, J.J.; Braun, S.; Simpson, J.; Chen, S.S.; Lang, S.; Hong, S.Y.; Thompson, G.; Peters-Lidard, C.

    2009-01-01

    A Goddard bulk microphysical parameterization is implemented into the Weather Research and Forecasting (WRF) model. This bulk microphysical scheme has three different options, 2ICE (cloud ice & snow), 3ICE-graupel (cloud ice, snow & graupel) and 3ICE-hail (cloud ice, snow & hail). High-resolution model simulations are conducted to examine the impact of microphysical schemes on different weather events: a midlatitude linear convective system and an Atlantic hurricane. The results suggest that microphysics has a major impact on the organization and precipitation processes associated with a summer midlatitude convective line system. The Goddard 3ICE scheme with the cloud ice-snow-hail configuration agreed better with observations ill of rainfall intensity and having a narrow convective line than did simulations with the cloud ice-snow-graupel and cloud ice-snow (i.e., 2ICE) configurations. This is because the Goddard 3ICE-hail configuration has denser precipitating ice particles (hail) with very fast fall speeds (over 10 m/s) For an Atlantic hurricane case, the Goddard microphysical scheme (with 3ICE-hail, 3ICE-graupel and 2ICE configurations) had no significant impact on the track forecast but did affect the intensity slightly. The Goddard scheme is also compared with WRF's three other 3ICE bulk microphysical schemes: WSM6, Purdue-Lin and Thompson. For the summer midlatitude convective line system, all of the schemes resulted in simulated precipitation events that were elongated in southwest-northeast direction in qualitative agreement with the observed feature. However, the Goddard 3ICE-hail and Thompson schemes were closest to the observed rainfall intensities although the Goddard scheme simulated more heavy rainfall (over 48 mm/h). For the Atlantic hurricane case, none of the schemes had a significant impact on the track forecast; however, the simulated intensity using the Purdue-Lin scheme was much stronger than the other schemes. The vertical distributions of

  14. New, Improved Goddard Bulk-Microphysical Schemes for Studying Precipitation Processes in WRF

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo

    2007-01-01

    An improved bulk microphysical parameterization is implemented into the Weather Research and Forecasting ()VRF) model. This bulk microphysical scheme has three different options, 2ICE (cloud ice & snow), 3ICE-graupel (cloud ice, snow & graupel) and 3ICE-hail (cloud ice, snow & hail). High-resolution model simulations are conducted to examine the impact of microphysical schemes on two different weather events (a midlatitude linear convective system and an Atlantic hurricane). The results suggest that microphysics has a major impact on the organization and precipitation processes associated with a summer midlatitude convective line system. The Goddard 3ICE scheme with a cloud ice-snow-hail configuration agreed better with observations in terms of rainfall intensity and a narrow convective line than did simulations with a cloud ice-snow-graupel or cloud ice-snow (i.e., 2ICE) configuration. This is because the 3ICE-hail scheme includes dense ice precipitating (hail) particle with very fast fall speed (over 10 in For an Atlantic hurricane case, the Goddard microphysical schemes had no significant impact on the track forecast but did affect the intensity slightly. The improved Goddard schemes are also compared with WRF's three other 3ICE bulk microphysical schemes: WSM6, Purdue-Lin and Thompson. For the summer midlatitude convective line system, all of the schemes resulted in simulated precipitation events that were elongated in the southwest-northeast direction in qualitative agreement with the observed feature. However, the Goddard 3ICE scheme with the hail option and the Thompson scheme agree better with observations in terms of rainfall intensity, expect that the Goddard scheme simulated more heavy rainfall (over 48 mm/h). For the Atlantic hurricane case, none of the schemes had a significant impact on the track forecast; however, the simulated intensity using the Purdue-Lin scheme was much stronger than the other schemes. The vertical distributions of model

  15. The relationship between latent heating, vertical velocity, and precipitation processes: The impact of aerosols on precipitation in organized deep convective systems

    NASA Astrophysics Data System (ADS)

    Tao, Wei-Kuo; Li, Xiaowen

    2016-06-01

    A high-resolution, two-dimensional cloud-resolving model with spectral-bin microphysics is used to study the impact of aerosols on precipitation processes in both a tropical oceanic and a midlatitude continental squall line with regard to three processes: latent heating (LH), cold pool dynamics, and ice microphysics. Evaporative cooling in the lower troposphere is found to enhance rainfall in low cloud condensation nuclei (CCN) concentration scenarios in the developing stages of a midlatitude convective precipitation system. In contrast, the tropical case produced more rainfall under high CCN concentrations. Both cold pools and low-level convergence are stronger for those configurations having enhanced rainfall. Nevertheless, latent heat release is stronger (especially after initial precipitation) in the scenarios having more rainfall in both the tropical and midlatitude environment. Sensitivity tests are performed to examine the impact of ice and evaporative cooling on the relationship between aerosols, LH, and precipitation processes. The results show that evaporative cooling is important for cold pool strength and rain enhancement in both cases. However, ice microphysics play a larger role in the midlatitude case compared to the tropics. Detailed analysis of the vertical velocity-governing equation shows that temperature buoyancy can enhance updrafts/downdrafts in the middle/lower troposphere in the convective core region; however, the vertical pressure gradient force (PGF) is of the same order and acts in the opposite direction. Water loading is small but of the same order as the net PGF-temperature buoyancy forcing. The balance among these terms determines the intensity of convection.

  16. Strong and Biostable Hyaluronic Acid-Calcium Phosphate Nanocomposite Hydrogel via in Situ Precipitation Process.

    PubMed

    Jeong, Seol-Ha; Koh, Young-Hag; Kim, Suk-Wha; Park, Ji-Ung; Kim, Hyoun-Ee; Song, Juha

    2016-03-14

    Hyaluronic acid (HAc) hydrogel exhibits excellent biocompatibility, but it has limited biomedical application due to its poor biomechanical properties as well as too-fast enzymatic degradation. In this study, we have developed an in situ precipitation process for the fabrication of a HAc-calcium phosphate nanocomposite hydrogel, after the formation of the glycidyl methacrylate-conjugated HAc (GMHA) hydrogels via photo-cross-linking, to improve the mechanical and biological properties under physiological conditions. In particular, our process facilitates the rapid incorporation of calcium phosphate (CaP) nanoparticles of uniform size and with minimal agglomeration into a polymer matrix, homogeneously. Compared with pure HAc, the nanocomposite hydrogels exhibit improved mechanical behavior. Specifically, the shear modulus is improved by a factor of 4. The biostability of the nanocomposite hydrogel was also significantly improved compared with that of pure HAc hydrogels under both in vitro and in vivo conditions. PMID:26878437

  17. Process Optimization of Seed Precipitation Tank with Multiple Impellers Using Computational Fluid Dynamics

    NASA Astrophysics Data System (ADS)

    Zhao, Hong-Liang; Lv, Chao; Liu, Yan; Zhang, Ting-An

    2015-07-01

    The complex fluid flow in a large-scale tank stirred with multiple Ekato Intermig impellers used in the seed precipitation process was numerically analyzed by the computational fluid dynamics method. The flow field, liquid-solid mixing, and power consumption were simulated by adopting the Eulerian granular multiphase model and standard k- ɛ turbulence model. A steady multiple reference frame approach was used to represent impeller rotation. The simulated results showed that the five-stage multiple Intermig impeller coupled with sloped baffles could generate circulation loops in axial, which is good for solid uniform mixing. The fluid is overmixed under the current industrial condition. Compared with the current process conditions, a three-stage impeller with L/ D of 1.25 not only could meet the industrial requirements, but also more than 20% power could be saved. The results have important implications for reliable design and optimal performance for industry.

  18. Development and Demonstration of a Sulfate Precipitation Process for Hanford Waste Tank 241-AN-107

    SciTech Connect

    SK Fiskum; DE Kurath; BM Rapko

    2000-08-16

    A series of precipitation experiments were conducted on Hanford waste tank 241-AN-107 samples in an effort to remove sulfate from the matrix. Calcium nitrate was added directly to AN-107 sub-samples to yield several combinations of Ca:CO{sub 3} mole ratios spanning a range of 0:1 to 3:1 to remove carbonate as insoluble CaCO{sub 3}. Similarly barium nitrate was added directly to the AN-107 aliquots, or to the calcium pretreated AN-107 aliquots, giving of Ba:SO{sub 4} mole ratios spanning a range of 1:1 to 5:1 to precipitate sulfate as BaSO{sub 4}. Initial bulk carbonate removal was required for successful follow-on barium sulfate precipitation. A {ge} 1:1 mole ratio of Ca:CO{sub 3} was found to lower the carbonate concentration such that Ba would react preferentially with the sulfate. A follow-on 1:1 mole ratio of Ba:SO{sub 4} resulted in 70% sulfate removal. The experiment was scaled up with a 735-mL aliquot of AN-107 for more complete testing. Calcium carbonate and barium sulfate settling rates were determined and fates of selected cations, anions, and radionuclides were followed through the various process steps. Seventy percent of the sulfate was removed in the scale-up test while recovering 63% of the filtrate volume. Surprisingly, during the scale-up test a sub-sample of the CaCO{sub 3}/241-AN-107 slurry was found to lose fluidity upon standing for {le} 2 days. Metathesis with BaCO{sub 3} at ambient temperature was also evaluated using batch contacts at various BaCO{sub 3}:SO{sub 4} mole ratios with no measurable success.

  19. Describing the catchment-averaged precipitation as a stochastic process improves parameter and input estimation

    NASA Astrophysics Data System (ADS)

    Del Giudice, Dario; Albert, Carlo; Rieckermann, Jörg; Reichert, Peter

    2016-04-01

    Rainfall input uncertainty is one of the major concerns in hydrological modeling. Unfortunately, during inference, input errors are usually neglected, which can lead to biased parameters and implausible predictions. Rainfall multipliers can reduce this problem but still fail when the observed input (precipitation) has a different temporal pattern from the true one or if the true nonzero input is not detected. In this study, we propose an improved input error model which is able to overcome these challenges and to assess and reduce input uncertainty. We formulate the average precipitation over the watershed as a stochastic input process (SIP) and, together with a model of the hydrosystem, include it in the likelihood function. During statistical inference, we use "noisy" input (rainfall) and output (runoff) data to learn about the "true" rainfall, model parameters, and runoff. We test the methodology with the rainfall-discharge dynamics of a small urban catchment. To assess its advantages, we compare SIP with simpler methods of describing uncertainty within statistical inference: (i) standard least squares (LS), (ii) bias description (BD), and (iii) rainfall multipliers (RM). We also compare two scenarios: accurate versus inaccurate forcing data. Results show that when inferring the input with SIP and using inaccurate forcing data, the whole-catchment precipitation can still be realistically estimated and thus physical parameters can be "protected" from the corrupting impact of input errors. While correcting the output rather than the input, BD inferred similarly unbiased parameters. This is not the case with LS and RM. During validation, SIP also delivers realistic uncertainty intervals for both rainfall and runoff. Thus, the technique presented is a significant step toward better quantifying input uncertainty in hydrological inference. As a next step, SIP will have to be combined with a technique addressing model structure uncertainty.

  20. Fractionation of atmospheric acid and base components within storm events by precipitation scavenging processes.

    PubMed

    Liljestrand, H M

    1992-01-01

    Concentrations of ions in storm rainwater in Texas have been monitored for each 0.254 mm increment of precipitation. The changes in concentrations have been analyzed to investigate the role of differential rates of scavenging of particulate matter of differing particle size, and especially the major acid and base components. The empirical trend at the onset of rainfall is a chemical fractionation of acids and bases with correspondingly wide pH variations. These results are confirmed by model calculations, which show a significant preferential scavenging of calcium relative to sulfate in the first 10 mm of rainfall, resulting in fractionation of bases and acids from their atmospheric concentrations. Previous studies, using Target Transformation Factor Analysis of ion concentrations in storm precipitation and regional ambient aerosol data, statistically determined the average source for acidic secondary species and alkaline particulate matter. Two types of crustal sources were identified as western and eastern soil dust. In this study, an alternate physical explanation for these two soil dust factors is offered. As a storm progresses, the elements in the local soil dust are fractionated as a result of their differential rates of precipitation scavenging, enriching species predominantly in the fine particle size and depleting elements predominantly in the coarse particle size. This fractionation process results in a single source having different elemental ratios at the beginning and at the end of a rain event. For Austin, Dallas, and Tyler, Texas, the soil dust previously identified as being from eastern sources could, instead, be a fractionated form of the western soil source.

  1. Aerosol-radiation-cloud and precipitation processes during dust events (Invited)

    NASA Astrophysics Data System (ADS)

    Kallos, G. B.; Solomos, S.; Kushta, J.; Mitsakou, C.; Athanasiadis, P.; Spyrou, C.; Tremback, C.

    2010-12-01

    In places like the Mediterranean region where anthropogenic aerosols coexist with desert dust the aerosol-radiation-cloud processes are rather complicated. The mixture of different age of air pollutants of anthropogenic origin with Saharan dust and sea salt may lead to the formation of other particles with different characteristics. The mixture of the aerosols and gases from anthropogenic and natural origin (desert dust and sea salt) results in the formation of new types of PM with different physico-chemical properties and especially hygroscopicity (e.g. inside clouds or within the marine boundary layer) through heterogeneous processes. The new particle formation has different characteristics and therefore they have different impacts on cloud formation and precipitation. In an attempt to better understand links and feedbacks between air pollution and climate the new Integrated Community Limited Area Modeling System - ICLAMS has been developed. ICLAMS is an enhanced version of RAMS.v6 modeling system. It includes sub-models for the dust and sea salt cycles, gas and aqueous phase chemistry, gas to particle conversion and heterogeneous chemistry processes. All these processes are directly coupled with meteorology. RAMS has an explicit cloud microphysical scheme with eight categories of hydrometeors. The cloud droplets spectrum is explicitly calculated from model meteorology and prognostic CCN and IN properties (total number concentration, size distribution properties and chemical composition). Sulphate coated dust particles are efficient CCN because of their increased hygroscopicity while uncoated dust particles are efficient IN. The photochemical processes are directly linked to the RAMS radiative transfer scheme, which in the new model is RRTM. Absorption of short wave solar radiation from airborne dust leads to heating of the dust layer which can also affect the cloud processes. Mid and low tropospheric warming by dust is one of the new features that the model can

  2. Robust design of binary countercurrent adsorption separation processes

    SciTech Connect

    Storti, G. ); Mazzotti, M.; Morbidelli, M.; Carra, S. )

    1993-03-01

    The separation of a binary mixture, using a third component having intermediate adsorptivity as desorbent, in a four section countercurrent adsorption separation unit is considered. A procedure for the optimal and robust design of the unit is developed in the frame of Equilibrium Theory, using a model where the adsorption equilibria are described through the constant selectivity stoichiometric model, while mass-transfer resistances and axial mixing are neglected. By requiring that the unit achieves complete separation, it is possible to identify a set of implicity constraints on the operating parameters, that is, the flow rate ratios in the four sections of the unit. From these constraints explicit bounds on the operating parameters are obtained, thus yielding a region in the operating parameters space, which can be drawn a priori in terms of the adsorption equilibrium constants and the feed composition. This result provides a very convenient tool to determine both optimal and robust operating conditions. The latter issue is addressed by first analyzing the various possible sources of disturbances, as well as their effect on the separation performance. Next, the criteria for the robust design of the unit are discussed. Finally, these theoretical findings are compared with a set of experimental results obtained in a six port simulated moving bed adsorption separation unit operated in the vapor phase.

  3. Evolutionary multi-objective optimization based comparison of multi-column chromatographic separation processes for a ternary separation.

    PubMed

    Heinonen, Jari; Kukkonen, Saku; Sainio, Tuomo

    2014-09-01

    Performance characteristics of two advanced multi-column chromatographic separation processes with discontinuous feed, Multi-Column Recycling Chromatogrphy (MCRC) and Japan Organo (JO), were investigated for a ternary separation using multi-objective optimization with an evolutionary algorithm. Conventional batch process was used as a reference. Fractionation of a concentrated acid hydrolysate of wood biomass into sulfuric acid, monosaccharide, and acetic acid fractions was used as a model system. Comparison of the separation processes was based on selected performance parameters in their optimized states. Flow rates and step durations were taken as decision variables whereas the column configuration and dimensions were fixed. The MCRC process was found to be considerably more efficient than the other processes with respect to eluent consumption. The batch process gave the highest productivity and the JO process the lowest. Both of the multi-column processes gave significantly higher monosaccharide yield than the batch process. When eluent consumption and monosaccharide yield are taken into account together with productivity, the MCRC process was found to be the most efficient in the studied case. PMID:25060000

  4. CHARACTERIZATION OF A PRECIPITATE REACTOR FEED TANK (PRFT) SAMPLE FROM THE DEFENSE WASTE PROCESSING FACILITY (DWPF)

    SciTech Connect

    Crawford, C.; Bannochie, C.

    2014-05-12

    A sample of from the Defense Waste Processing Facility (DWPF) Precipitate Reactor Feed Tank (PRFT) was pulled and sent to the Savannah River National Laboratory (SRNL) in June of 2013. The PRFT in DWPF receives Actinide Removal Process (ARP)/ Monosodium Titanate (MST) material from the 512-S Facility via the 511-S Facility. This 2.2 L sample was to be used in small-scale DWPF chemical process cell testing in the Shielded Cells Facility of SRNL. A 1L sub-sample portion was characterized to determine the physical properties such as weight percent solids, density, particle size distribution and crystalline phase identification. Further chemical analysis of the PRFT filtrate and dissolved slurry included metals and anions as well as carbon and base analysis. This technical report describes the characterization and analysis of the PRFT sample from DWPF. At SRNL, the 2.2 L PRFT sample was composited from eleven separate samples received from DWPF. The visible solids were observed to be relatively quick settling which allowed for the rinsing of the original shipping vials with PRFT supernate on the same day as compositing. Most analyses were performed in triplicate except for particle size distribution (PSD), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and thermogravimetric analysis (TGA). PRFT slurry samples were dissolved using a mixed HNO3/HF acid for subsequent Inductively Coupled Plasma Atomic Emission Spectroscopy (ICPAES) and Inductively Coupled Plasma Mass Spectroscopy (ICP-MS) analyses performed by SRNL Analytical Development (AD). Per the task request for this work, analysis of the PRFT slurry and filtrate for metals, anions, carbon and base were primarily performed to support the planned chemical process cell testing and to provide additional component concentrations in addition to the limited data available from DWPF. Analysis of the insoluble solids portion of the PRFT slurry was aimed at detailed characterization of these solids (TGA, PSD

  5. METHOD FOR RECOVERING PLUTONIUM VALUES FROM SOLUTION USING A BISMUTH HYDROXIDE CARRIER PRECIPITATE

    DOEpatents

    Faris, B.F.

    1961-04-25

    Carrier precipitation processes for separating plutonium values from aqueous solutions are described. In accordance with the invention a bismuth hydroxide precipitate is formed in the plutonium-containing solution, thereby carrying plutonium values from the solution.

  6. Separation: An Integral Aspect of the Staffing Process.

    ERIC Educational Resources Information Center

    Conley, Valerie Martin

    2001-01-01

    The model of staffing in higher education proposed by Winston and Creamer (1997) includes essential components of recruitment and selection, orientation, supervision, staff development, and performance appraisal. Proposes that the model has a significant oversight-when staff leave their position. Separation is proposed as a necessary component of…

  7. Easing the Separation Process for Infants, Toddlers, and Families

    ERIC Educational Resources Information Center

    Balaban, Nancy

    2006-01-01

    Attachment and separation are the stuff of which life is made. The bonds between family and child promote resilience, self-regulation, and a positive sense of self. In this article, the author focuses her discussion on the importance of attachment to children's development. She has cited some theories that can help her explain further. For…

  8. Experimental Validation of Hybrid Distillation-Vapor Permeation Process for Energy Efficient Ethanol-Water Separation

    EPA Science Inventory

    The energy demand of distillation-based systems for ethanol recovery and dehydration can be significant, particularly for dilute solutions. An alternative separation process integrating vapor stripping with a vapor compression step and a vapor permeation membrane separation step...

  9. Experimental Validation of Hybrid Distillation-Vapor Permeation Process for Energy Efficient Ethanol-Water Separation

    EPA Science Inventory

    The energy demand of distillation-based systems for ethanol recovery and dehydration can be significant, particularly for dilute solutions. An alternative separation process integrating vapor stripping with a vapor compression step and a vapor permeation membrane separation step,...

  10. HEAVY OIL PROCESS MONITOR: AUTOMATED ON-COLUMN ASPHALTENE PRECIPITATION AND RE-DISSOLUTION

    SciTech Connect

    John F. Schabron; Joseph F. Rovani Jr; Mark Sanderson

    2006-06-01

    About 37-50% (w/w) of the heptane asphaltenes from unpyrolyzed residua dissolve in cyclohexane. As pyrolysis progresses, this number decrease to below 15% as coke and toluene insoluble pre-coke materials appear. This solubility measurement can be used after coke begins to form, unlike the flocculation titration, which cannot be applied to multi-phase systems. Currently, the procedure for the isolation of heptane asphaltenes and the determination of the amount of asphaltenes soluble in cyclohexane spans three days. A more rapid method to measure asphaltene solubility was explored using a novel on-column asphaltene precipitation and re-dissolution technique. This was automated using high performance liquid chromatography (HPLC) equipment with a step gradient sequence using the solvents: heptane, cyclohexane, toluene:methanol (98:2). Results for four series of original and pyrolyzed residua were compared with data from the gravimetric method. The measurement time was reduced from three days to forty minutes. The separation was expanded further with the use of four solvents: heptane, cyclohexane, toluene, and cyclohexanone or methylene chloride. This provides a fourth peak which represents the most polar components, in the oil.

  11. 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).

  12. Using Multi-scale Modeling Systems to Study the Precipitation Processes

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo

    2007-01-01

    Numerical cloud models, which are based the non-hydrostatic equations of motion, have been extensively applied to cloud-scale and mesoscale processes during the past four decades. Because cloud-scale dynamics are treated explicitly, uncertainties stemming from convection that have to be parameterized in (hydrostatic) large-scale models are obviated, or at least mitigated, in cloud models. Global models will use the non-hydrostatic framework when their horizontal resolution becomes about 10 km, the theoretical limit for the hydrostatic approximation. This juncture will be reached one to two decades from now. Recently, a multi-scale modeling system with unified physics was developed at NASA Goddard. It consists of (1) a cloud-resolving model (CRM), (2) a regional scale model, (3) a coupled CRM and global model, and (4) a land modeling system. The same microphysical processes, long and short wave radiative transfer processes and the explicit cloud-radiation, and cloudland surface interactive processes are applied in this multi-scale modeling system. In this talk, a review of developments and applications of the multi-scale modeling system will be presented. In particular, the results from using multi-scale modeling system to study the interactions between clouds, precipitation, and aerosols will be presented.

  13. Interface-coupled dissolution-precipitation processes allow a photonic crystal to replace an ionic crystal along lattice planes

    NASA Astrophysics Data System (ADS)

    Liesegang, Moritz; Milke, Ralf

    2015-04-01

    Nanocolloidal amorphous silica (SiO2×nH2O) is a major component of environmental aqueous solutions and surface coatings on rocks or mineral grains. Detailed knowledge of amorphous silica formation is indispensable for a better understanding of silicate rock alteration and diagenetic processes. We analyzed a wide range of samples from the Australian precious opal fields in South Australia and Queensland using petrographic microscopy, XRPD, SEM, and EPMA to characterize opaline silica, the mineral assemblage, and the host rock. Over the past 90 Ma the Lower Cretaceous lithologies of central Australia have undergone a weathering regime ranging from sub-tropical to arid, in which pH fluctuated from alkaline to acidic. The prolonged chemical alteration of sedimentary rocks derived from andesitic volcaniclastics and organic matter liberated large volumes of silica into solution, eventually leading to precipitation of nanocolloidal amorphous silica and formation of opal-A. A regular arrangement of close-packed uniform (monodisperse) spheres permits diffraction of white light and gives rise to the famous play-of-color. The opals in this study consist of silica spheres with an average diameter of 100-320 nm and often show a prominent core-shell structure. Two groups are separated by their relative standard deviation (RSD): monodisperse spheres (RSD<6%) and polydisperse spheres (RDS>10%). Monodisperse and polydisperse spheres are separated by their Na/K ratio, restricting the appearance of monodisperse spheres to values <1.2 and polydisperse spheres to values >3.0. We suggest that the Na/K ratio represents significant differences in the overall solution characteristics. The associated minerals (e.g., alunite, gypsum, kaolinite, K feldspar) indicate large variations of fluid composition and pH. Probably, uniform spheres grew at acidic pH, with repulsive forces large enough to arrange them in an ordered array prior to the evaporation of interstitial fluids. The investigation

  14. Process for separating hydrocarbon pollution from a hydroorganic medium

    SciTech Connect

    Sader, G.

    1980-01-22

    Water, polluted with hydrocarbons and similar pollutants in which separation occurs into an upper layer, rich in hydrocarbons and residues, and a lower layer consisting of a hydrocarbon suspension or emulsion in water, is treated to remove the pollutants from the water. The upper layer is treated with quaternary ammonium salts to separate the heavy residue from a clear (or ligh-colored) supernatant layer, analogous to fuel oil and reusable; the lower layer is then treated with a mixture of a polyose (starch, for example) and a coagulant (for example, ordinary alum) to obtain a practically pure water. This treatment may be applied to water containing oil products and, in particular, water collected from degreasing and dewaxing plants.

  15. Process for separation of the rare earths by solvent extraction

    DOEpatents

    Mason, George W.; Lewey, Sonia

    1977-04-05

    Production rates for solvent extraction separation of the rare earths and yttrium from each other can be improved by the substitution of di(2-ethylhexyl) mono-thiophosphoric acid for di(2-ethylhexyl) phosphoric acid. The di(2-ethylhexyl) mono-thiophosphoric acid does not form an insoluble polymer at approximately 50% saturation as does the former extractant, permitting higher feed solution concentration and thus greater throughput.

  16. The separation of convective and stratiform precipitation regions of simulated Typhoon Chanchu and its sensitivity to the number concentration of cloud droplets

    NASA Astrophysics Data System (ADS)

    Xu, Suishan; Lin, Wenshi; Sui, C.-H.

    2013-03-01

    Following a numerical simulation study, we analyze the effect of the parameter of the cloud condensation nuclei concentration (CNP) on Typhoon Chanchu in convective, stratiform, and mixed precipitation areas based on the following three experiments: (1) a control (CTL) experiment using a mesoscale model and the Reisner-2 cloud scheme with the CNP value specified as 100 cm- 3; (2) a very clean marine (VCM) CNP experiment (CNP = 25 cm- 3); (3) and a severe contamination (SC) CNP experiment (CNP = 1000 cm- 3). We compare and analyze the simulated cloud structure and microphysical processes of the three experiments within the convective, stratiform, and mixed areas. The three precipitating areas are classified based on the ratio of cloud ice content to cloud water content at all precipitating grids proposed by Sui et al. (2007). The results show that the intensities of most microphysical processes are the largest in the convective area and the smallest in the stratiform area. Ice is dominant in the stratiform region and the water hydrometeor is dominant in the convective region. Furthermore, cloud water develops more quickly than cloud ice do in the mixed area. The response of the convective area to a varying CNP is greater than that of the stratiform area, and the mixed area is only slightly sensitive to the CNP. The dominance of cloud microphysical processes related to the growth of water hydrometeors weakens as the CNP increases.

  17. The mechanism underlying calcium phosphate precipitation on titanium via ultraviolet, visible, and near infrared laser-assisted biomimetic process

    NASA Astrophysics Data System (ADS)

    Mahanti, Moumita; Nakamura, Maki; Pyatenko, Alexander; Sakamaki, Ikuko; Koga, Kenji; Oyane, Ayako

    2016-08-01

    We recently developed a rapid single-step calcium phosphate (CaP) precipitation technique on several substrates using a laser-assisted biomimetic process (LAB process). In this process, ultraviolet (UV, λ  =  355 nm) pulsed laser irradiation has been applied to a substrate that is immersed in a supersaturated CaP solution. In the present study, the LAB process for CaP precipitation on a titanium substrate was successfully expanded to include not only UV but also visible (VIS, λ  =  532 nm) and near infrared (NIR, λ  =  1064 nm) lasers. Surface heating and plasma-mediated surface reactions (micro-deformation, oxidization, photoexcitation, and wetting) generated by UV, VIS, or NIR lasers are considered to be involved in the CaP precipitation on the titanium surface in the LAB process. The kinetics of these reactions and consequently of CaP precipitation were dependent on the laser wavelength and fluence. The higher laser fluence did not always accelerate CaP precipitation on the substrate; rather, it was found that an optimal range of fluence exists for each laser wavelength. These results suggest that for efficient CaP precipitation, a suitable laser wavelength should be selected according to the optical absorption properties of the substrate material and the laser fluence should also be adjusted to induce surface heating and plasma-mediated surface reactions that are favorable for CaP precipitation.

  18. Linear Friction Welding Process Model for Carpenter Custom 465 Precipitation-Hardened Martensitic Stainless Steel

    NASA Astrophysics Data System (ADS)

    Grujicic, M.; Yavari, R.; Snipes, J. S.; Ramaswami, S.; Yen, C.-F.; Cheeseman, B. A.

    2014-06-01

    An Arbitrary Lagrangian-Eulerian finite-element analysis is combined with thermo-mechanical material constitutive models for Carpenter Custom 465 precipitation-hardened martensitic stainless steel to develop a linear friction welding (LFW) process model for this material. The main effort was directed toward developing reliable material constitutive models for Carpenter Custom 465 and toward improving functional relations and parameterization of the workpiece/workpiece contact-interaction models. The LFW process model is then used to predict thermo-mechanical response of Carpenter Custom 465 during LFW. Specifically, temporal evolutions and spatial distribution of temperature within, and expulsion of the workpiece material from, the weld region are examined as a function of the basic LFW process parameters, i.e., (a) contact-pressure history, (b) reciprocation frequency, and (c) reciprocation amplitude. Examination of the results obtained clearly revealed the presence of three zones within the weld, i.e., (a) Contact-interface region, (b) Thermo-mechanically affected zone, and (c) heat-affected zone. While there are no publicly available reports related to Carpenter Custom 465 LFW behavior, to allow an experiment/computation comparison, these findings are consistent with the results of our ongoing companion experimental investigation.

  19. NEXRAD quantitative precipitation estimates, data acquisition, and processing for the DuPage County, Illinois, streamflow-simulation modeling system

    USGS Publications Warehouse

    Ortel, Terry W.; Spies, Ryan R.

    2015-11-19

    Next-Generation Radar (NEXRAD) has become an integral component in the estimation of precipitation (Kitzmiller and others, 2013). The high spatial and temporal resolution of NEXRAD has revolutionized the ability to estimate precipitation across vast regions, which is especially beneficial in areas without a dense rain-gage network. With the improved precipitation estimates, hydrologic models can produce reliable streamflow forecasts for areas across the United States. NEXRAD data from the National Weather Service (NWS) has been an invaluable tool used by the U.S. Geological Survey (USGS) for numerous projects and studies; NEXRAD data processing techniques similar to those discussed in this Fact Sheet have been developed within the USGS, including the NWS Quantitative Precipitation Estimates archive developed by Blodgett (2013).

  20. NEXRAD quantitative precipitation estimates, data acquisition, and processing for the DuPage County, Illinois, streamflow-simulation modeling system

    USGS Publications Warehouse

    Ortel, Terry W.; Spies, Ryan R.

    2015-01-01

    Next-Generation Radar (NEXRAD) has become an integral component in the estimation of precipitation (Kitzmiller and others, 2013). The high spatial and temporal resolution of NEXRAD has revolutionized the ability to estimate precipitation across vast regions, which is especially beneficial in areas without a dense rain-gage network. With the improved precipitation estimates, hydrologic models can produce reliable streamflow forecasts for areas across the United States. NEXRAD data from the National Weather Service (NWS) has been an invaluable tool used by the U.S. Geological Survey (USGS) for numerous projects and studies; NEXRAD data processing techniques similar to those discussed in this Fact Sheet have been developed within the USGS, including the NWS Quantitative Precipitation Estimates archive developed by Blodgett (2013).

  1. A continuous and highly effective static mixing process for antisolvent precipitation of nanoparticles of poorly water-soluble drugs.

    PubMed

    Dong, Yuancai; Ng, Wai Kiong; Hu, Jun; Shen, Shoucang; Tan, Reginald B H

    2010-02-15

    Rapid and homogeneous mixing of the solvent and antisolvent is critical to achieve submicron drug particles by antisolvent precipitation technique. This work aims to develop a continuous and highly effective static mixing process for antisolvent precipitation of nanoparticles of poorly water-soluble drugs with spironolactone as a model drug. Continuous antisolvent production of drug nanoparticles was carried out with a SMV DN25 static mixer comprising 6-18 mixing elements. The total flow rate ranged from 1.0 to 3.0 L/min while the flow rate ratio of solvent to antisolvent was maintained at 1:9. It is found that only 6 mixing elements were sufficient to precipitate the particles in the submicron range. Increasing the number of elements would further reduce the precipitated particle size. Increasing flow rate from 1.0 to 3.0 L/min did not further reduce the particle size, while higher drug concentrations led to particle size increase. XRD and SEM results demonstrated that the freshly precipitated drug nanoparticles are in the amorphous state, which would, in presence of the mixture of solvent and antisolvent, change to crystalline form in short time. The lyophilized spironolactone nanoparticles with lactose as lyoprotectant possessed good redispersibility and showed 6.6 and 3.3 times faster dissolution rate than that of lyophilized raw drug formulation in 5 and 10 min, respectively. The developed static mixing process exhibits high potential for continuous and large-scale antisolvent precipitation of submicron drug particles. PMID:19922777

  2. Formation of regular structures in the process of phase separation.

    PubMed

    Krekhov, Alexei

    2009-03-01

    Phase separation under directional quenching has been studied in a Cahn-Hilliard model. In distinct contrast to the disordered patterns which develop under a homogeneous quench, periodic stripe patterns are generated behind the quench front. Their wavelength is uniquely defined by the velocity of the quench interface in a wide range. Numerical simulations match perfectly analytical results obtained in the limit of small and large velocities of the quench interface. Additional periodic modulation of the quench interface may lead to cellular patterns. The quenching protocols analyzed are expected to be an effective tool in technological applications to design nanostructured materials. PMID:19392008

  3. Mission Operations Center (MOC) - Precipitation Processing System (PPS) Interface Software System (MPISS)

    NASA Technical Reports Server (NTRS)

    Ferrara, Jeffrey; Calk, William; Atwell, William; Tsui, Tina

    2013-01-01

    MPISS is an automatic file transfer system that implements a combination of standard and mission-unique transfer protocols required by the Global Precipitation Measurement Mission (GPM) Precipitation Processing System (PPS) to control the flow of data between the MOC and the PPS. The primary features of MPISS are file transfers (both with and without PPS specific protocols), logging of file transfer and system events to local files and a standard messaging bus, short term storage of data files to facilitate retransmissions, and generation of file transfer accounting reports. The system includes a graphical user interface (GUI) to control the system, allow manual operations, and to display events in real time. The PPS specific protocols are an enhanced version of those that were developed for the Tropical Rainfall Measuring Mission (TRMM). All file transfers between the MOC and the PPS use the SSH File Transfer Protocol (SFTP). For reports and data files generated within the MOC, no additional protocols are used when transferring files to the PPS. For observatory data files, an additional handshaking protocol of data notices and data receipts is used. MPISS generates and sends to the PPS data notices containing data start and stop times along with a checksum for the file for each observatory data file transmitted. MPISS retrieves the PPS generated data receipts that indicate the success or failure of the PPS to ingest the data file and/or notice. MPISS retransmits the appropriate files as indicated in the receipt when required. MPISS also automatically retrieves files from the PPS. The unique feature of this software is the use of both standard and PPS specific protocols in parallel. The advantage of this capability is that it supports users that require the PPS protocol as well as those that do not require it. The system is highly configurable to accommodate the needs of future users.

  4. Stability investigations of zinc and cobalt precipitates immobilized by in situ bioprecipitation (ISBP) process.

    PubMed

    Satyawali, Yamini; Schols, Edo; Van Roy, Sandra; Dejonghe, Winnie; Diels, Ludo; Vanbroekhoven, Karolien

    2010-09-15

    In situ bioprecipitation (ISBP), which involves immobilizing the metals as precipitates (mainly sulphides) in the solid phase, is an effective method of metal removal from contaminated groundwater. This study investigated the stability of metal precipitates formed after ISBP in two different solid-liquid matrices (artificial and natural). The artificial matrix consisted of sand, Zn (200 mg L(-1)), artificial groundwater and a carbon source (electron donor). Here the stability of the Zn precipitates was evaluated by manipulation of redox and pH. The natural system matrices included aquifer material and groundwater samples collected from three different metal (Zn and Co) contaminated sites and different carbon sources were provided as electron donors. In the natural matrices, metal precipitates stability was assessed by changing aquifer redox conditions, sequential extraction, and BIOMET assay. The results indicated that, in the artificial matrix, redox manipulation did not impact the Zn precipitates. However the sequential pH change proved detrimental, releasing 58% of the precipitated Zn back into liquid phase. In natural matrices, the applied carbon source largely affected the stability of metal precipitates. Elemental analysis performed on the precipitates formed in natural matrix showed that the main elements of the precipitates were sulphur with Zn and Co.

  5. 40 CFR 63.137 - Process wastewater provisions-oil-water separators.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Chemical Manufacturing Industry for Process Vents, Storage Vessels, Transfer Operations, and Wastewater § 63.137 Process wastewater provisions—oil-water separators. (a) For each oil-water separator that... 40 Protection of Environment 10 2014-07-01 2014-07-01 false Process wastewater...

  6. 40 CFR 63.137 - Process wastewater provisions-oil-water separators.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Manufacturing Industry for Process Vents, Storage Vessels, Transfer Operations, and Wastewater § 63.137 Process wastewater provisions—oil-water separators. (a) For each oil-water separator that receives, manages, or... 40 Protection of Environment 9 2011-07-01 2011-07-01 false Process wastewater...

  7. 40 CFR 63.137 - Process wastewater provisions-oil-water separators.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Chemical Manufacturing Industry for Process Vents, Storage Vessels, Transfer Operations, and Wastewater § 63.137 Process wastewater provisions—oil-water separators. (a) For each oil-water separator that... 40 Protection of Environment 10 2012-07-01 2012-07-01 false Process wastewater...

  8. 40 CFR 63.137 - Process wastewater provisions-oil-water separators.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Chemical Manufacturing Industry for Process Vents, Storage Vessels, Transfer Operations, and Wastewater § 63.137 Process wastewater provisions—oil-water separators. (a) For each oil-water separator that... 40 Protection of Environment 10 2013-07-01 2013-07-01 false Process wastewater...

  9. Migration and Growth: Separation-Individuation Processes in Immigrant Students in Israel.

    ERIC Educational Resources Information Center

    Mirsky, Julia; Kaushinsky, Frieda

    1989-01-01

    Describes and analyzes central experiences of immigrant students in Israel, suggesting that immigration entails process of separation from homeland and from internal representations of objects and self linked to homeland. Conceptualizes process in terms of Mahler's separation-individuation model. Notes that for immigrant students, process occurs…

  10. Application of membrane processes to alcohol-water separation: Improving the energy efficiency of biofuel production

    EPA Science Inventory

    Pervaporation • Membrane-based separation process • Not filtration Separation based on solution-diffusion transport through non-porous or “molecularly-porous” membrane Permeate is a vapor • Permeate contains only volatile compounds • Able to separate mixtures of mis...

  11. Bibliography of articles and reports on mineral-separation techniques, processes, and applications

    NASA Technical Reports Server (NTRS)

    Harmon, R. S.

    1971-01-01

    A bibliography of published articles and reports on mineral-separation techniques, processes, and applications is presented along with an author and subject index. This information is intended for use in the mineral-separation facility of the Lunar Receiving Laboratory at the NASA Manned Spacecraft Center and as an aid and reference to persons involved or interested in mineral separation.

  12. Modeling wildfire impact on hydrologic processes using the Precipitation Runoff Modeling System

    NASA Astrophysics Data System (ADS)

    Logan, R. J.; Hogue, T. S.; Hay, L.

    2015-12-01

    As large magnitude wildfires persist across the western United States, understanding their impact on hydrologic behavior and predicting regional streamflow response is increasingly important. Sediment and debris flows, as well as elevated flood levels in burned watersheds are often addressed, but wildfires also alter the timing and overall volume of both short and long-term runoff, making the prediction of post-fire streamflow critical for water resources management. Watershed models are a powerful tool for both representing wildfire runoff response and discerning the processes that induce that response. In the current study, selected wildfire-impacted basins across the western United States are modeled using the Precipitation Runoff Modeling System (PRMS) in order to develop a generalized approach. This distributed-parameter, physical process based watershed model allows us to target specific processes, while still having the flexibility to account for uncertainty and complex physical interactions that are not explicitly represented in model parameterization. Two change detection modeling approaches are considered. First, models calibrated using pre-fire data are applied to the post-fire period and residuals between simulated and observed flow are examined to quantify the response in each specific watershed. Here an analysis of the model's ability to detect long-term response is also presented. Second, the post-fire conditions are modeled by adjusting appropriate parameters, and the parameter differences are used to guide process learning. In this latter method, parameters are specifically tailored to represent processes affected by wildfire, and scenarios with different parameter interactions are statistically compared. The results of these analyses are synthesized to provide a framework for predicting wildfire runoff response using PRMS, which will ultimately empower water resource decisions.

  13. Process for separating dissolved solids from a liquid using an anti-solvent and multiple effect evaporators

    DOEpatents

    Daniels, Edward J.; Jody, Bassam J.; Bonsignore, Patrick V.

    1994-01-01

    A process and system for treating aluminum salt cake containing water soluble halide salts by contacting the salt cake with water to dissolve water soluble halide salts forming a saturated brine solution. Transporting a portion of about 25% of the saturated brine solution to a reactor and introducing into the saturated brine solution at least an equal volume of a water-miscible low-boiling organic material such as acetone to precipitate a portion of the dissolved halide salts forming a three-phase mixture of an aqueous-organic-salt solution phase and a precipitated salt phase and an organic rich phase. The precipitated salt phase is separated from the other phases and the organic rich phase is recycled to the reactor. The remainder of the saturated brine solution is sent to a multiple effect evaporator having a plurality of stages with the last stage thereof producing low grade steam which is used to boil off the organic portion of the solution which is recycled.

  14. Process for separating dissolved solids from a liquid using an anti-solvent and multiple effect evaporators

    DOEpatents

    Daniels, E.J.; Jody, B.J.; Bonsignore, P.V.

    1994-07-19

    A process and system are disclosed for treating aluminum salt cake containing water soluble halide salts by contacting the salt cake with water to dissolve water soluble halide salts forming a saturated brine solution. Transporting a portion of about 25% of the saturated brine solution to a reactor and introducing into the saturated brine solution at least an equal volume of a water-miscible low-boiling organic material such as acetone to precipitate a portion of the dissolved halide salts forming a three-phase mixture of an aqueous-organic-salt solution phase and a precipitated salt phase and an organic rich phase. The precipitated salt phase is separated from the other phases and the organic rich phase is recycled to the reactor. The remainder of the saturated brine solution is sent to a multiple effect evaporator having a plurality of stages with the last stage thereof producing low grade steam which is used to boil off the organic portion of the solution which is recycled. 3 figs.

  15. STRONTIUM PRECIPITATION

    DOEpatents

    McKenzie, T.R.

    1960-09-13

    A process is given for improving the precipitation of strontium from an aqueous phosphoric-acid-containing solution with nickel or cobalt ferrocyanide by simultaneously precipitating strontium or calcium phosphate. This is accomplished by adding to the ferrocyanide-containing solution calcium or strontium nitrate in a quantity to yield a concentration of from 0.004 to 0.03 and adjusting the pH of the solution to a value of above 8.

  16. Development of observed precipitation and meteorological database to understand the wet deposition and dispersion processes in March 2011

    NASA Astrophysics Data System (ADS)

    Yatagai, Akiyo; Watanabe, Akira; Ishihara, Masahito; Ishihara, Hirohiko; Takara, Kaoru

    2014-05-01

    The transport and diffusion of the radioactive pollutants from the Fukushima-Daiichi NPP inthe atmosphere caused a disaster for residents in and around Fukushima. Studies have sought to understand the transport, diffusion, and deposition process, and to understand the movement of radioactive pollutants through the soil, vegetation, rivers, and groundwater. However, a detailed simulation and understanding of the distribution of radioactive compounds depend on a simulation of precipitation and on the information on the timing of the emission of these radioactive pollutants from the NPP. Further, precipitation type and its amount affect the various transport process of the radioactive nuclides. Hence, this study first examine the qualitative precipitation pattern and timing in March 2011 using X-band radar data from Fukushima University and three dimensional C-band radar data network of Japan Meteorological Agency. Second, by collecting rain-gauge network and other surface meteorological data, we estimate quantitative precipitation and its type (rain/snow) according to the same method used to create APHRODITE daily grid precipitation (Yatagai et al., 2012) and judge of rain/snow (Yasutomi et al., 2011). For example, the data clarified that snowfall was observed on the night of Mar 15 into the morning of Mar 16 throughout Fukushima prefecture. This had an important effect on the radioactive contamination pattern in Fukushima prefecture. The precipitation pattern itself does not show one-on-one correspondence with the contamination pattern. While the pollutants transported northeast of the NPP and through north Kanto (about 200 km southwest of Fukushima and, 100 km north of Tokyo) went to the northeast, the timing of the precipitation causing the fallout, i.e., wet-deposition, is important. Although the hourly Radar-AMeDAS 1-km-mesh precipitation data of JMA are available publically, it does not represent the precipitation pattern in Nakadori, in central Fukushima

  17. System and process for efficient separation of biocrudes and water in a hydrothermal liquefaction system

    DOEpatents

    Elliott, Douglas C.; Hart, Todd R.; Neuenschwander, Gary G.; Oyler, James R.; Rotness, Jr, Leslie J.; Schmidt, Andrew J.; Zacher, Alan H.

    2016-08-02

    A system and process are described for clean separation of biocrudes and water by-products from hydrothermal liquefaction (HTL) product mixtures of organic and biomass-containing feedstocks at elevated temperatures and pressures. Inorganic compound solids are removed prior to separation of biocrude and water by-product fractions to minimize formation of emulsions that impede separation. Separation may be performed at higher temperatures that reduce heat loss and need to cool product mixtures to ambient. The present invention thus achieves separation efficiencies not achieved in conventional HTL processing.

  18. PROCESS FOR SEPARATING AMERICIUM AND CURIUM FROM RARE EARTH ELEMENTS

    DOEpatents

    Baybarz, R.D.; Lloyd, M.H.

    1963-02-26

    This invention relates to methods of separating americium and curium values from rare earth values. In accordance with the invention americium, curium, and rare earth values are sorbed on an anion exchange resin. A major portion of the rare earth values are selectively stripped from the resin with a concentrated aqueous solution of lithium chloride, and americium, curium, and a minor portion of rare earth values are then stripped from the resin with a dilute aqueous solution of lithium chloride. The americium and curium values are further purified by increasing the concentration of lithium chloride in the solution to at least 8 molar and selectively extracting rare earth values from the resulting solution with a monoalkylphosphoric acid. (AEC)

  19. Novel catalytic process for flue gas conditioning in electrostatic precipitators of coal-fired power plants.

    PubMed

    Zagoruiko, Andrey; Balzhinimaev, Bair; Vanag, Sergey; Goncharov, Vladimir; Lopatin, Sergey; Zykov, Alexander; Anichkov, Sergey; Zhukov, Yurii; Yankilevich, Vassily; Proskokov, Nikolay; Hutson, Nick

    2010-08-01

    One of the most important environmental protection problems for coal-fired power plants is prevention of atmospheric pollution of flying ash. The ash particles are typically removed from flue gases by means of electrostatic precipitators, for which the efficiency may be significantly increased by lowering the resistance of fly ash, which may be achieved by controlled addition of microamounts of sulfur trioxide (SO3) into the flue gases. This paper describes the novel technology for production of SO3 by sulfur dioxide (SO2) oxidation using the combined catalytic system consisting of conventional vanadium catalyst and novel platinum catalyst on the base of silicazirconia glass-fiber supports. This combination provides highly efficient SO, oxidation in a wide temperature range with achievement of high SO, conversion. The performed pilot tests have demonstrated reliable and stable operation, excellent resistance of the novel catalytic system to deactivation, and high overall efficiency of the proposed process. The scale of the plant was equivalent to the commercial prototype; therefore, no further scale-up of the oxidation process is required. PMID:20842940

  20. PRECIPITATION OF PLUTONOUS PEROXIDE

    DOEpatents

    Barrick, J.G.; Manion, J.P.

    1961-08-15

    A precipitation process for recovering plutonium values contained in an aqueous solution is described. In the process for precipitating plutonium as plutonous peroxide, hydroxylamine or hydrazine is added to the plutoniumcontaining solution prior to the addition of peroxide to precipitate plutonium. The addition of hydroxylamine or hydrazine increases the amount of plutonium precipitated as plutonous peroxide. (AEC)

  1. Birth order effects on the separation process in young adults: an evolutionary and dynamic approach.

    PubMed

    Ziv, Ido; Hermel, Orly

    2011-01-01

    The present study analyzes the differential contribution of a familial or social focus in imaginative ideation (the personal fable and imagined audience mental constructs) to the separation-individuation process of firstborn, middleborn, and lastborn children. A total of 160 young adults were divided into 3 groups by birth order. Participants' separation-individuation process was evaluated by the Psychological Separation Inventory, and results were cross-validated by the Pathology of Separation-Individuation Inventory. The Imaginative Ideation Inventory tested the relative dominance of the familial and social environments in participants' mental constructs. The findings showed that middleborn children had attained more advanced separation and were lower in family-focused ideation and higher in nonfamilial social ideation. However, the familial and not the social ideation explained the variance in the separation process in all the groups. The findings offer new insights into the effects of birth order on separation and individuation in adolescents and young adults.

  2. Precipitation process for the removal of technetium values from nuclear waste solutions

    DOEpatents

    Walker, D.D.; Ebra, M.A.

    1985-11-21

    High efficiency removal of techetium values from a nuclear waste stream is achieved by addition to the waste stream of a precipitant contributing tetraphenylphosphonium cation, such that a substantial portion of the technetium values are precipitated as an insoluble pertechnetate salt.

  3. SEPARATION OF PLUTONYL IONS

    DOEpatents

    Connick, R.E.; McVey, Wm.H.

    1958-07-15

    A process is described for separating plutonyl ions from the acetate ions with which they are associated in certaln carrier precipitation methods of concentrating plutonium. The method consists in adding alkaline earth metal ions and subsequently alkalizing the solution, causing formation of an alkaltne earth plutonate precipitate. Barium hydroxide is used in a preferred embodiment since it provides alkaline earth metal ion and alkalizes the solution in one step forming insoluble barium platonate.

  4. Phase separation and ordering process in Al-Li alloys studied by small-angle neutron scattering and neutron diffraction

    SciTech Connect

    Furusaka, M.; Fujikawa, S.I.; Tranquada, J.M.

    1993-07-01

    To study phase separation kinetics of Al-9.5at.%Li polycrystalline alloys in which precipitates have ordered Al{sub 3}Li ({delta}{prime}) structure, profile analysis of small-angle neutron scattering and superlattice reflections (100) and (110) were done. A small-angle scattering instrument and a triple-axis spectrometer in elastic mode were used in the measurements. Strong texture was observed in the reflections. Therefore, measurements were done using the crystal orientation where the intensity of the reflection was at the maximum. Profiles of small-angle scattering and superlattice reflections were almost identical at higher momentum transfer side. At lower momentum transfer side, small-angle scattering showed interference effects, but superlattice reflection did not show any sign of interference. Integrated intensities of superlattice reflections were obtained and compared with small-angle scattering intensity. The order parameter was not saturated in the {delta}{prime} precipitates at the early stage of the phase separation process.

  5. Remote Sensing of Precipitation Using Multiparameter Radar: Statistics, Processing Algorithms and Analysis Techniques.

    NASA Astrophysics Data System (ADS)

    Liu, Li.

    With the advent of the multiparameter weather radar, i.e., dual-polarization, dual-frequency, Doppler radar, radar meteorologists have been able to study physical processes in precipitation in more detail, and the quantitative measurement of rainfall as well as the identification of different types of hydrometeors have become possible. However, the effects of propagation through the rain medium must be carefully considered whenever dual-polarization techniques are considered. The correction of propagation effects such as attenuation, differential attenuation and differential propagation phase in precipitation are very important for quantitative interpretation of echo powers at high frequencies. In this dissertation, a simplified scattering matrix with propagation effects is described. A number of parameters are derived based on the covariance matrix of the scattering element array. The processing techniques for estimating some specific parameters, such as K_{dp }, A_{x} and intrinsic LDR using the CSU-CHILL and CP-2 radar measurements, are discussed. Recent research has suggested that the copolar correlation coefficient termed rho_ {hv}(0) can be used to identify large hail and improve polarization estimates of rainfall. The typical measured values of rho_{hv }(0) at S-band vary between 0.8-1.0. For applications to hail identification the required accuracy should be within +/-0.01 while for rainfall improvement a higher accuracy is necessary, e.g., within +/-0.001. We discuss the statistics of several estimators of rho_{hv }(0) using the Gaussian spectrum approximation from both an analytical approach and via simulations. The standard deviation and bias in rho _{hv}(0) are computed as a function of number of samples, Doppler spectral width and mean rho_{hv}(0). The effect of finite signal-to-noise ratio (SNR) and phase noise are also studied via simulations. Time series data collected with the CSU-CHILL radar are analyzed and compared with the simulations. Antenna

  6. [Near infrared spectroscopy on-line and real-time monitoring of alcohol precipitation process of reduning injection].

    PubMed

    Wang, Yong-Xiang; Mi, Hui-Juan; Zhang, Chuan-Li; Su, Guang; Bi, Yu-An; Wang, Zhen-Zhong; Xiao, Wei

    2014-12-01

    Near infrared (NIR) spectroscopy as a kind of rapid process analysis technology has been successfully applied in Chinese medicine pharmaceutical process. In this research, the technology was adopted to establish the rapid quantitative analysis models of main indicators from the Lonicera japonica and Artemisia annua alcohol precipitation process of Reduning injection. On-line NIR spectra of 142 samples from alcohol precipitation process were collected and the content of main indicators for each sample were detected through off-line HPLC. With eliminating outliers, determination of spectra pretreatment method and selecting optimal band, the NIR quantitative calibration model for each indicator was established using partial least squares (PLS). These models were used to predict the unknown samples from precipitation process of Reduning injection to achieve the goal of rapid detection. The results showed that the models were ideal. The correlation coefficients of models for neochlorogenic acid, chlorogenic acid, 4-O-caffeoylquinic acid and secoxyloganin were 0.973 872, 0.985 449, 0.975 509 and 0.979 790, respectively and their relative standard errors of prediction (RSEP) were 2.922 49%, 2.341 37%, 2.930 40% and 2.184 60%, respectively. This study indicated that the NIR quantitative calibration model showed good stability and precision, and it can be used in rapid quantitative detection of main indicators of efficacy in order to on-line monitor the alcohol precipitation process of Reduning injection. PMID:25911810

  7. Need for constraints in component-separable color image processing

    NASA Astrophysics Data System (ADS)

    Thomas, Bruce A.

    1995-03-01

    The component-wise processing of color image data in performed in a variety of applications. These operations are typically carried out using Lookup Table (LUT) based processing techniques, making them well suited for digital implementation. A general exposition of this type of processing is provided, indicating it's remarkable utility along with some of the practical issues that can arise. These motivate a call for the use of constraints in the types of operators that are used during the construction of LUTs. Several particularly useful classes of constrained operators are identified. These lead to an object-oriented approach generalized to operated in a variety of color spaces. The power of this type of framework is then demonstrated via several novel applications in the HSL color space.

  8. Functionalized sorbent for chemical separations and sequential forming process

    DOEpatents

    Fryxell, Glen E.; Zemanian, Thomas S.

    2012-03-20

    A highly functionalized sorbent and sequential process for making are disclosed. The sorbent includes organic short-length amino silanes and organic oligomeric polyfunctional amino silanes that are dispersed within pores of a porous support that form a 3-dimensional structure containing highly functionalized active binding sites for sorption of analytes.

  9. Precipitation Recycling

    NASA Technical Reports Server (NTRS)

    Eltahir, Elfatih A. B.; Bras, Rafael L.

    1996-01-01

    The water cycle regulates and reflects natural variability in climate at the regional and global scales. Large-scale human activities that involve changes in land cover, such as tropical deforestation, are likely to modify climate through changes in the water cycle. In order to understand, and hopefully be able to predict, the extent of these potential global and regional changes, we need first to understand how the water cycle works. In the past, most of the research in hydrology focused on the land branch of the water cycle, with little attention given to the atmospheric branch. The study of precipitation recycling which is defined as the contribution of local evaporation to local precipitation, aims at understanding hydrologic processes in the atmospheric branch of the water cycle. Simply stated, any study on precipitation recycling is about how the atmospheric branch of the water cycle works, namely, what happens to water vapor molecules after they evaporate from the surface, and where will they precipitate?

  10. WATER-GAS SHIFT WITH INTEGRATED HYDROGEN SEPARATION PROCESS

    SciTech Connect

    Maria Flytzani-Stephanopoulos; Xiaomei Qi; Scott Kronewitter

    2004-02-01

    This project involved fundamental research and development of novel cerium oxide-based catalysts for the water-gas-shift reaction and the integration of these catalysts with Pd-alloy H{sub 2} -separation membranes supplying high purity hydrogen for fuel cell use. Conditions matching the requirements of coal gasifier-exit gas streams were examined in the project. Cu-cerium oxide was identified as the most promising high-temperature water-gas shift catalyst for integration with H{sub 2}-selective membranes. Formulations containing iron oxide were found to deactivate in the presence of CO{sub 2}. Cu-containing ceria catalysts, on the other hand, showed high stability in CO{sub 2}-rich gases. This type gas will be present over much of the catalyst, as the membrane removes the hydrogen produced from the shift reaction. The high-temperature shift catalyst composition was optimized by proper selection of dopant type and amount in ceria. The formulation 10at%Cu-Ce(30at%La)O{sub x} showed the best performance, and was selected for further kinetic studies. WGS reaction rates were measured in a simulated coal-gas mixture. The apparent activation energy, measured over aged catalysts, was equal to 70.2 kJ/mol. Reaction orders in CO, H{sub 2}O, CO{sub 2} and H{sub 2} were found to be 0.8, 0.2, -0.3, and -0.3, respectively. This shows that H{sub 2}O has very little effect on the reaction rate, and that both CO{sub 2} and H{sub 2} weakly inhibit the reaction. Good stability of catalyst performance was found in 40-hr long tests. A flat (38 cm{sup 2}) Pd-Cu alloy membrane reactor was used with the catalyst washcoated on oxidized aluminum screens close coupled with the membrane. To achieve higher loadings, catalyst granules were layered on the membrane itself to test the combined HTS activity/ H{sub 2} -separation efficiency of the composite. Simulated coal gas mixtures were used and the effect of membrane on the conversion of CO over the catalyst was evidenced at high space

  11. Implementing New Quality Control and Processing Systems for Hourly Precipitation Data

    NASA Astrophysics Data System (ADS)

    Rennie, J.; Wilson, A.; Lawrimore, J. H.; Ray, R.; Menne, M. J.

    2011-12-01

    ://www.ncdc.noaa.gov/hrlyhpd/ These data have been quality controlled using a set of checks including checks for spikes, global extremes, gaps, and climatological outliers. Efforts are ongoing to implement a complete suite of quality control procedures developed through empirical assessments of false positive and flag rates. Once completed these new quality control procedures will replace the current process of manual review and editing which is part of the DSI-3240 Hourly Precipitation Dataset. This paper will provide a synopsis of the new processing system, including data ingest, as well as an extensive overview of the current and proposed quality control algorithms.

  12. Identifying Hydrologic Processes in Agricultural Watersheds Using Precipitation-Runoff Models

    USGS Publications Warehouse

    Linard, Joshua I.; Wolock, David M.; Webb, Richard M.T.; Wieczorek, Michael E.

    2009-01-01

    Understanding the fate and transport of agricultural chemicals applied to agricultural fields will assist in designing the most effective strategies to prevent water-quality impairments. At a watershed scale, the processes controlling the fate and transport of agricultural chemicals are generally understood only conceptually. To examine the applicability of conceptual models to the processes actually occurring, two precipitation-runoff models - the Soil and Water Assessment Tool (SWAT) and the Water, Energy, and Biogeochemical Model (WEBMOD) - were applied in different agricultural settings of the contiguous United States. Each model, through different physical processes, simulated the transport of water to a stream from the surface, the unsaturated zone, and the saturated zone. Models were calibrated for watersheds in Maryland, Indiana, and Nebraska. The calibrated sets of input parameters for each model at each watershed are discussed, and the criteria used to validate the models are explained. The SWAT and WEBMOD model results at each watershed conformed to each other and to the processes identified in each watershed's conceptual hydrology. In Maryland the conceptual understanding of the hydrology indicated groundwater flow was the largest annual source of streamflow; the simulation results for the validation period confirm this. The dominant source of water to the Indiana watershed was thought to be tile drains. Although tile drains were not explicitly simulated in the SWAT model, a large component of streamflow was received from lateral flow, which could be attributed to tile drains. Being able to explicitly account for tile drains, WEBMOD indicated water from tile drains constituted most of the annual streamflow in the Indiana watershed. The Nebraska models indicated annual streamflow was composed primarily of perennial groundwater flow and infiltration-excess runoff, which conformed to the conceptual hydrology developed for that watershed. The hydrologic

  13. Feedbacks between climate change, surface processes, and extreme convective precipitation events (Invited)

    NASA Astrophysics Data System (ADS)

    Galewsky, J.

    2009-12-01

    In a classic 1951 paper, Luna Leopold showed that the ratio of rainfall extrema to rainfall averages increases as the climate becomes more arid. This line of thinking has influenced much geomorphology research, but the basic meteorological mechanisms involved remain unknown. The potential for drought to increase both precipitation intensity and slope erodibility, which further decreases soil and vegetation cover, suggests the potential for previously unrecognized feedbacks between climate and landscape dynamics in semi-arid regions. The modeling framework used here is similar to that used for studies of oceanic radiative-convective equilibrium but uses surface sensible and latent heat fluxes derived from GCM projections of future climate change for the American Southwest. The model is run for 30 days until an equilibrium is established between radiative cooling and convective heating in the atmosphere. Prelimary analysis based on extreme value theory shows potentially important changes in the characteristics of convection over semi-arid landscapes as a result of projected anthropogenic climate change. The concept of an equilibrium convective ensemble, and its sensitivity to changing surface processes, may thus be a useful complement to geomorphic studies of landscape-climate interactions.

  14. Classical nucleation theory for solute precipitation amended with diffusion and reaction processes near the interface

    NASA Astrophysics Data System (ADS)

    Borisenko, Alexander

    2016-05-01

    During the processes of nucleation and growth of a precipitate cluster from a supersaturated solution, the diffusion flux between the cluster and the solution changes the solute concentration near the cluster-solution interface from its average bulk value. This feature affects the rates of attachment and detachment of solute atoms at the interface, and, therefore, the entire nucleation-growth kinetics is altered. Unless quite obvious, this effect has been ignored in classical nucleation theory. To illustrate the results of this approach, for the case of homogeneous nucleation, we calculate the total solubility and the nucleation rate as functions of two parameters of the model (the reduced interface energy and the inverse second Damköhler number), and we compare these results to the classical ones. One can conclude that discrepancies with classical nucleation theory are great in the diffusion-limited regime, when the rate of bulk diffusion is small compared to the rate of interface reactions, while in the opposite interface-limited case they vanish.

  15. Classical nucleation theory for solute precipitation amended with diffusion and reaction processes near the interface.

    PubMed

    Borisenko, Alexander

    2016-05-01

    During the processes of nucleation and growth of a precipitate cluster from a supersaturated solution, the diffusion flux between the cluster and the solution changes the solute concentration near the cluster-solution interface from its average bulk value. This feature affects the rates of attachment and detachment of solute atoms at the interface, and, therefore, the entire nucleation-growth kinetics is altered. Unless quite obvious, this effect has been ignored in classical nucleation theory. To illustrate the results of this approach, for the case of homogeneous nucleation, we calculate the total solubility and the nucleation rate as functions of two parameters of the model (the reduced interface energy and the inverse second Damköhler number), and we compare these results to the classical ones. One can conclude that discrepancies with classical nucleation theory are great in the diffusion-limited regime, when the rate of bulk diffusion is small compared to the rate of interface reactions, while in the opposite interface-limited case they vanish.

  16. A mathematical process model for cadmium precipitation by sulfate-reducing bacterial biofilms.

    PubMed

    White, Christopher; Dennis, John S; Gadd, Geoffrey M

    2003-04-01

    Sulfate-reducing bacterial (SRB) biofilms were grown in a flowcell in which the biofilm was grown on a fixed area of support which was supplied with recirculating medium of defined composition, volume and circulation rate. Utilization rates for substrates, production rates for products and material mass-balances for substrates and Cd were determined and a mathematical model constructed based on theoretical considerations and experimental data. The rate of sulfate reduction was zero-order with respect to sulfate concentration and unaffected by the presence of 250 microM Cd. However, Cd reacted with the sulfide produced by the SRB to produce solid CdS, removing sulfide from solution. A significant fraction of colloidal CdS was formed which flocculated relatively slowly, limiting the overall rate of Cd bioprecipitation. Experiments using chemically-synthesised colloidal CdS indicated that the biofilm did not influence colloidal Cd flocculation but stimulated sedimentation of the CdS precipitate once flocculated. A mathematical model of bioprecipitation was developed in which the CdS formation rate was determined by two steps: sulfide production by the biofilm and colloidal CdS flocculation. This model accurately predicted the behaviour of further experimental runs which indicated the adequacy of the overall process description. The model also indicated that the rate of sulfate reduction and the rate of flocculation were the key variables in optimising the biofilm system for metal removal.

  17. Removal of an anionic dye by adsorption/precipitation processes using alkaline white mud.

    PubMed

    Zhu, Mao-Xu; Lee, Li; Wang, Hai-Hua; Wang, Zheng

    2007-11-19

    Alkaline white mud (AWM) has been investigated as a low-cost material for removal of an anionic dye, acid blue 80. The effects of contact time, initial pH of dye solution, AWM dosage, and the presence of inorganic anion sulphate or phosphate ion on removal of the dye were evaluated. The results show that AWM could be used as an effective material for removal of acid blue 80 in a pre or main process, particularly at high dye concentration (>300 mgL(-1)), reaching maximum removal efficiency of 95%. At low dye concentration, surface adsorption is mainly responsible for the dye removal, while chemical precipitation of the dye anions with soluble Ca(2+) and Mg(2+) may play a dominant role for the dye removal at high concentration, producing much less sludge than conventional adsorption method. Solution pH has only a limited effect on the dye removal due to high alkalinity and large pH buffer capacity of AWM suspension and thereby pH is not a limiting factor in pursuing high dye removal. The presence of SO(4)(2-) could reduce the dye removal by AWM only when SO(4)(2-) concentration is beyond 0.7 mmolL(-1). The dye removal may be significantly suppressed by the presence of phosphate with increasing concentration, and the reduction in the dye removal is much larger at high dye concentrations than at low ones. PMID:17532132

  18. Treatment of anaerobic digester effluents of nylon wastewater through chemical precipitation and a sequencing batch reactor process.

    PubMed

    Huang, Haiming; Song, Qianwu; Wang, Wenjun; Wu, Shaowei; Dai, Jiankun

    2012-06-30

    Chemical precipitation, in combination with a sequencing batch reactor (SBR) process, was employed to remove pollutants from anaerobic digester effluents of nylon wastewater. The effects of the chemicals along with various Mg:N:P ratios on the chemical precipitation (struvite precipitation) were investigated. When brucite and H(3)PO(4) were applied at an Mg:N:P molar ratio of 3:1:1, an ammonia-removal rate of 81% was achieved, which was slightly more than that (80%) obtained with MgSO(4)·7H(2)O and Na(2)HPO(4)·12H(2)O at Mg:N:P molar ratios greater than the stoichiometric ratio. To further reduce the ammonia loads of the successive biotreatment, an overdose of phosphate with brucite and H(3)PO(4) was applied during chemical precipitation. The ammonia-removal rate at the Mg:N:P molar ratio of 3.5:1:1.05 reached 88%, with a residual PO(4)-P concentration of 16 mg/L. The economic analysis showed that the chemical cost of chemical precipitation could be reduced by about 41% when brucite and H(3)PO(4) were used instead of MgSO(4)·7H(2)O and Na(2)HPO(4)·12H(2)O. The subsequent biological process that used a sequencing batch reactor showed high removal rates of contaminants. The quality of the final effluent met the requisite effluent-discharging standards.

  19. A novel chemical oxo-precipitation (COP) process for efficient remediation of boron wastewater at room temperature.

    PubMed

    Shih, Yu-Jen; Liu, Chia-Hsun; Lan, Wei-Cheng; Huang, Yao-Hui

    2014-09-01

    Chemical oxo-precipitation (COP), which combines treatment with an oxidant and precipitation using metal salts, was developed for treating boron-containing water under milder conditions (room temperature, pH 10) than those of conventional coagulation processes. The concentration of boron compounds was 1000mg-BL(-1). They included boric acid (H3BO3) and perborate (NaBO3). Precipitation using calcium chloride eliminated 80% of the boron from the perborate solution, but was unable to treat boric acid. COP uses hydrogen peroxide (H2O2) to pretreat boric acid, substantially increasing the removal of boron from boric acid solution by chemical precipitation from less than 5% to 80%. Furthermore, of alkaline earth metals, barium ions are the most efficient precipitant, and can increase the 80% boron removal to 98.5% at [H2O2]/[B] and [Ba]/[B] molar ratios of 2 and 1, respectively. The residual boron in the end water of COP contained 15ppm-B: this value cannot be achieved using conventional coagulation processes.

  20. Warming and increased precipitation frequency on the Colorado Plateau: implications for biological soil crusts and soil processes

    SciTech Connect

    Zelikova, Tamara J.; Housman, David C.; Grote, Ed E.; Neher, Deborah A.; Belnap, Jayne

    2012-01-20

    Changes in temperature and precipitation are expected to influence ecosystem processes worldwide. Despite their globally large extent, few studies to date have examined the effects of climate change in desert ecosystems, where biological soil crusts are key nutrient cycling components. The goal of this work was to assess how increased temperature and frequency of summertime precipitation affect the contributions of crust organisms to soil processes. With a combination of experimental 2°C warming and altered summer precipitation frequency applied over 2 years, we measured soil nutrient cycling and the structure and function of crust communities. We saw no change in crust cover, composition, or other measures of crust function in response to 2°C warming and no effects on any measure of soil chemistry. In contrast, crust cover and function responded to increased frequency of summer precipitation, shifting from moss to cyanobacteria-dominated crusts; however, in the short timeframe we measured, there was no accompanying change in soil chemistry. Total bacterial and fungal biomass was also reduced in watered plots, while the activity of two enzymes increased, indicating a functional change in the microbial community. Taken together, our results highlight the limited effects of warming alone on biological soil crust communities and soil chemistry, but demonstrate the substantially larger effects of altered summertime precipitation.

  1. Process to separate transuranic elements from nuclear waste

    DOEpatents

    Johnson, Terry R.; Ackerman, John P.; Tomczuk, Zygmunt; Fischer, Donald F.

    1989-01-01

    A process for removing transuranic elements from a waste chloride electrolytic salt containing transuranic elements in addition to rare earth and other fission product elements so the salt waste may be disposed of more easily and the valuable transuranic elements may be recovered for reuse. The salt is contacted with a cadmium-uranium alloy which selectively extracts the transuranic elements from the salt. The waste salt is generated during the reprocessing of nuclear fuel associated with the Integral Fast Reactor (IFR).

  2. Corrosion study in the chemical air separation (MOLTOX trademark ) process

    SciTech Connect

    Kang, Doohee; Wong, Kai P.; Archer, R.A.; Cassano, A.A.

    1988-12-01

    This report presents the results of studies aimed at solving the corrosion problems encountered during operation of the MOLTOX{trademark} pilot plant. These studies concentrated on the screening of commercial and developmental alloys under conditions simulating operation conditions in this high temperature molten salt process. Process economic studies were preformed in parallel with the laboratory testing to ensure that an economically feasible solution would be achieved. In addition to the above DOE co-funded studies, Air Products and Chemicals pursued proprietary studies aimed at developing a less corrosive salt mixture which would potentially allow the use of chemurgically available alloys such as stainless steels throughout the system. These studies will not be reported here; however, the results of corrosion tests in the new less corrosive salt mixtures are reported. Because our own studies on salt chemistry impacts heavily on the overall process and thereby has an influence on the experimental work conducted under this contract, some of the studies discussed here were impacted by our own proprietary data. Therefore, the reasons behind some of the experiments presented herein will not be explained because that information is proprietary to Air Products. 14 refs., 42 figs., 21 tabs.

  3. AMERICIUM SEPARATIONS FROM NITRIC ACID PROCESS EFFLUENT STREAMS

    SciTech Connect

    M. BARR; G. JARVINEN; ET AL

    2000-08-01

    The aging of the US nuclear stockpile presents a number of challenges, including the ever-increasing radioactivity of plutonium residues from {sup 241}Am. Minimization of this weak gamma-emitter in process and waste solutions is desirable to reduce both worker exposure and the effects of radiolysis on the final waste product. Removal of americium from plutonium nitric acid processing effluents, however, is complicated by the presence of large.quantities of competing metals, particularly Fe and Al, and-strongly oxidizing acidic solutions. The reprocessing operation offers several points at which americium removal maybe attempted, and we are evaluating two classes of materials targeted at different steps in the process. Extraction chromatography resin materials loaded with three different alkylcarbamoyl phosphinates and phosphine oxides were accessed for Am removal efficiency and Am/Fe selectivity from 1-7 molar nitric acid solutions. Commercial and experimental mono- and bifunctional anion-exchange resins were evaluated for total alpha-activity removal from post-evaporator solutions whose composition, relative to the original nitric acid effluent, is reduced in acid and greatly increased in total salt content. With both classes of materials, americium/total alpha emission removal is sufficient to meet regulatory requirements even under sub-optimal conditions. Batch distribution coefficients, column performance data, and the effects of Fe-masking agents will be presented.

  4. Cloud Modeling Using Field Project Data for the Study of Precipitation Processes

    NASA Technical Reports Server (NTRS)

    Tao, W.-K.; Shie, C.-H.; Lang, S.; Simpson, J.

    2003-01-01

    The use of cloud-resolving models (CRMs) in the study of precipitation process and their relation to the large-scale environment can be generally categorized into two approaches. The first approach is so called "cloud ensemble modeling". In this approach, many clouds of different size in various stages of their lifecycles can be present at any model simulation time. Large-scale effects are derived from observations and imposed into the model as the main forcing. The advantage of this approach is that the modeled convection will be forced to have the same intensity, thermodynamic budget and organization as the obserations.This approach will also allow CRMs to perform multi-day or multi-week time integrations. The second approach usually requires initial temperature and water vapor profiles that have a medium to large CAPE, and open lateral boundary conditions are used. The modeled clouds could be termed "self-forced convection". Model improvements, such as in the microphysics, are achieved using the second approach. In cloud ensemble modeling, accurate large-scale advective tendencies for temperature and water vapor are the main forcing for the CRMs. We found that the large-scale advective terms for temperature and water vapor are not always consistent, For example, large-scale forcing could indicate strong drying which would produce cooling in the model through evaporation but not contain large-scale advective heating to compensate. This discrepancy in forcing would cause differences between the observed and modeled latent heating profiles. Good measurements of other quantities (i.e., surface fluxes and radiation) are also required to perform variational objective analysis that computes and minimizes a "cost function" that constrains the difference between the large-scale advective forcing in temperature and water vapor. With self-forced convection, accurate vertical distributions of temperature, moisture (water vapor), and horizontal winds are required. The timing

  5. The Role of Aerosols on Precipitation Processes: Cloud Resolving Model Simulations

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo; Li, X.; Matsui, T.

    2012-01-01

    identify the impact of ice processes, radiation and large-scale influence on cloud-aerosol interactive processes, especially regarding surface rainfall amounts and characteristics (i.e., heavy or convective versus light or stratiform types). In addition, an inert tracer was included to follow the vertical redistribution of aerosols by cloud processes. We will also give a brief review from observational evidence on the role of aerosol on precipitation processes.

  6. PROCESS FOR SEPARATING IODINE-132 FROM FISSION PRODUCTS

    DOEpatents

    Greene, M.W.; Tucker, W.D.; Samos, G.

    1960-06-28

    A process is given for isolating I/sup 132/ in substantially pure form. Te/sup 132/, which is the radioactive parent of I/sup 132/, is adsorbed on a finely divided mass of a chromatographic grade of refractory metal oxide. i.e., alumina, zirconia, titania, and ceria. After a period of time is allowed for the Te/sup 132/ to decay, a 0.001 to 0.01 molar solution of ammonium hydroxide is passed over the finely divided oxides and the I/sup 132/ values are eluted.

  7. Process to separate transuranic elements from nuclear waste

    DOEpatents

    Johnson, T.R.; Ackerman, J.P.; Tomczuk, Z.; Fischer, D.F.

    1989-03-21

    A process is described for removing transuranic elements from a waste chloride electrolytic salt containing transuranic elements in addition to rare earth and other fission product elements so the salt waste may be disposed of more easily and the valuable transuranic elements may be recovered for reuse. The salt is contacted with a cadmium-uranium alloy which selectively extracts the transuranic elements from the salt. The waste salt is generated during the reprocessing of nuclear fuel associated with the Integral Fast Reactor (IFR). 2 figs.

  8. Process to separate transuranic elements from nuclear waste

    DOEpatents

    Johnson, T.R.; Ackerman, J.P.; Tomczuk, Z.; Fischer, D.F.

    1988-07-12

    A process for removing transuranic elements from a waste chloride electrolytic salt containing transuranic elements in addition to rare earth and other fission product elements so the salt waste may be disposed of more easily and the valuable transuranic elements may be recovered for reuse. The salt is contacted with a cadmium-uranium alloy which selectively extracts the transuranic elements from the salt. The waste salt is generated during the reprocessing of nuclear fuel associated with the Integral Fast Reactor (IFR). 2 figs.

  9. Demonstration of Small Tank Tetraphenylborate Precipitation Process Using Savannah River Site High Level Waste

    SciTech Connect

    Peters, T.B.

    2001-09-10

    This report details the experimental effort to demonstrate the continuous precipitation of cesium from Savannah River Site High Level Waste using sodium tetraphenylborate. In addition, the experiments examined the removal of strontium and various actinides through addition of monosodium titanate.

  10. CO{sub 2} HYDRATE PROCESS FOR GAS SEPARATION

    SciTech Connect

    G. Deppe; R. Currier; D. Spencer

    2004-01-01

    Modifications were implemented to the hydrogen flow test rig per safety review comments, and the apparatus was tested for leaks. Tests were then done using Helium/CO{sub 2} mixtures to re-verify performance prior to hydrogen testing. It was discovered that hydrate formation was more difficult to initiate, and new initiation methods were developed to improve the tests. Delivery of ETM hardware continued and buildup of the ETM system continued, the ETM is now mechanically complete. The STU (pilot plant) site selection process was resumed because Tennessee Eastman declined to participate in the program. Two potential sites were visited: The Global Energy/Conoco-Phillips Wabash River Plant, and the Tampa Electric Polk Power Plant.

  11. Catalytic hydrogenation process and apparatus with improved vapor liquid separation

    DOEpatents

    Chervenak, Michael C.; Comolli, Alfred G.

    1980-01-01

    A continuous hydrogenation process and apparatus wherein liquids are contacted with hydrogen in an ebullated catalyst reaction zone with the liquids and gas flowing vertically upwardly through that zone into a second zone substantially free of catalyst particles and wherein the liquid and gases are directed against an upwardly inclining surface through which vertical conduits are placed having inlet ends at different levels in the liquid and having outlet ends at different levels above the inclined surface, such that vapor-rich liquid is collected and discharged through conduits terminating at a higher level above the inclined surface than the vapor-poor liquid which is collected and discharged at a level lower than the inclined surface.

  12. Efficient separations and processing crosscutting program 1996 technical exchange meeting. Proceedings

    SciTech Connect

    1996-02-01

    This document contains summaries of technology development presented at the 1996 Efficient Separations and Processing Crosscutting Program Technical Exchange Meeting. This meeting is held annually to promote a free exchange of ideas among technology developers, potential users and other interested parties within the EM community. During this meeting the following many separation processes technologies were discussed such as ion exchange, membrane separation, vacuum distillation, selective sorption, and solvent extraction. Other topics discussed include: waste forms; testing or inorganic sorbents for radionuclide and heavy metal removal; selective crystallization; and electrochemical treatment of liquid wastes. This is the leading abstract, individual papers have been indexed separately for the databases.

  13. Tropical Oceanic Precipitation Processes over Warm Pool: 2D and 3D Cloud Resolving Model Simulations

    NASA Technical Reports Server (NTRS)

    Tao, W.- K.; Johnson, D.

    1998-01-01

    Rainfall is a key link in the hydrologic cycle as well as the primary heat source for the atmosphere, The vertical distribution of convective latent-heat release modulates the large-scale circulations of the tropics, Furthermore, changes in the moisture distribution at middle and upper levels of the troposphere can affect cloud distributions and cloud liquid water and ice contents. How the incoming solar and outgoing longwave radiation respond to these changes in clouds is a major factor in assessing climate change. Present large-scale weather and climate models simulate cloud processes only crudely, reducing confidence in their predictions on both global and regional scales. One of the most promising methods to test physical parameterizations used in General Circulation Models (GCMS) and climate models is to use field observations together with Cloud Resolving Models (CRMs). The CRMs use more sophisticated and physically realistic parameterizations of cloud microphysical processes, and allow for their complex interactions with solar and infrared radiative transfer processes. The CRMs can reasonably well resolve the evolution, structure, and life cycles of individual clouds and cloud systems, The major objective of this paper is to investigate the latent heating, moisture and momenti,im budgets associated with several convective systems developed during the TOGA COARE IFA - westerly wind burst event (late December, 1992). The tool for this study is the Goddard Cumulus Ensemble (CCE) model which includes a 3-class ice-phase microphysical scheme, The model domain contains 256 x 256 grid points (using 2 km resolution) in the horizontal and 38 grid points (to a depth of 22 km depth) in the vertical, The 2D domain has 1024 grid points. The simulations are performed over a 7 day time period. We will examine (1) the precipitation processes (i.e., condensation/evaporation) and their interaction with warm pool; (2) the heating and moisture budgets in the convective and

  14. Electrically Conductive Diamond Membrane for Electrochemical Separation Processes.

    PubMed

    Gao, Fang; Nebel, Christoph E

    2016-07-20

    Electrochemically switchable selective membranes play an important role in selective filtration processes such as water desalination, industrial waste treatment, and hemodialysis. Currently, membranes for these purposes need to be optimized in terms of electrical conductivity and stability against fouling and corrosion. In this paper, we report the fabrication of boron-doped diamond membrane by template diamond growth on quartz fiber filters. The morphology and quality of the diamond coating are characterized via SEM and Raman spectroscopy. The membrane is heavily boron doped (>10(21) cm(-3)) with >3 V potential window in aqueous electrolyte. By applying a membrane potential against the electrolyte, the redox active species can be removed via flow-through electrolysis. Compared to planar diamond electrodes, the ∼250 times surface enlargement provided by such a membrane ensures an effective removal of target chemicals from the input electrolyte. The high stability of diamond enables the membrane to not only work at high membrane bias but also to be self-cleaning via in situ electrochemical oxidation. Therefore, we believe that the diamond membrane presented in this paper will provide a solution to future selective filtration applications especially in extreme conditions.

  15. Electrically Conductive Diamond Membrane for Electrochemical Separation Processes.

    PubMed

    Gao, Fang; Nebel, Christoph E

    2016-07-20

    Electrochemically switchable selective membranes play an important role in selective filtration processes such as water desalination, industrial waste treatment, and hemodialysis. Currently, membranes for these purposes need to be optimized in terms of electrical conductivity and stability against fouling and corrosion. In this paper, we report the fabrication of boron-doped diamond membrane by template diamond growth on quartz fiber filters. The morphology and quality of the diamond coating are characterized via SEM and Raman spectroscopy. The membrane is heavily boron doped (>10(21) cm(-3)) with >3 V potential window in aqueous electrolyte. By applying a membrane potential against the electrolyte, the redox active species can be removed via flow-through electrolysis. Compared to planar diamond electrodes, the ∼250 times surface enlargement provided by such a membrane ensures an effective removal of target chemicals from the input electrolyte. The high stability of diamond enables the membrane to not only work at high membrane bias but also to be self-cleaning via in situ electrochemical oxidation. Therefore, we believe that the diamond membrane presented in this paper will provide a solution to future selective filtration applications especially in extreme conditions. PMID:27396448

  16. Effects of solvent and alkaline earth metals on the heat-induced precipitation process of sodium caseinate.

    PubMed

    Lopez, Francesco; Cuomo, Francesca; Nostro, Pierandrea Lo; Ceglie, Andrea

    2013-01-01

    The precipitation temperatures of sodium caseinate in H(2)O and D(2)O in the presence of Mg(2+), Ca(2+), Sr(2+) and Ba(2+) were investigated through fluorescence, turbidity and conductivity experiments. As for the ability of the divalent cations (1-17.5mM) to induce the precipitation process in H(2)O, the sequence Ba(2+) ≥ Ca(2+)>Mg(2+)>Sr(2+) was found. Remarkably, while at low salt concentrations (<10mM) precipitation temperatures (T(Ps)) were found to change significantly depending on the specific cation, at higher concentrations (>10mM) the differences among the different cations were greatly reduced. By fitting these results with a modified Jones-Dole equation, we confirmed that the less hydrated ions possess a greater capacity to induce precipitation. In D(2)O, the order of ion ability to induce caseinate precipitation was Ba(2+)>Ca(2+)>Sr(2+)>Mg(2+). The different hydrophobicity between D(2)O and H(2)O was shown to affect significantly the T(Ps) of caseinate in the presence of calcium, strontium and barium.

  17. A modelling study on the effects of air quality on cloud processes and precipitation

    NASA Astrophysics Data System (ADS)

    Solomos, Stavros; Kushta, Jonilda; Kallos, George

    2010-05-01

    unique characteristics. The amount, size distribution and chemical composition of airborne particles is important for the cloud droplets nucleation process. Proper handling of those quantities is expected to improve our understanding on cloud microphysical processes and on the links between air quality and precipitation. The sensitivity of cloud and rain fields on the aerosol properties is discussed in this presentation.

  18. Investigation of Carbide Precipitation Process and Chromium Depletion during Thermal Treatment of Alloy 690

    NASA Astrophysics Data System (ADS)

    Jiao, S. Y.; Zhang, M. C.; Zheng, L.; Dong, J. X.

    2010-01-01

    For the purpose of studying the effect of heat treatment on carbide morphology and chromium concentration distribution, which are critical to the resistance of alloy 690 to stress corrosion cracking (SCC), a series of thermal treatments was performed. A model taking into account the intercorrelated dynamic process between the carbide precipitation and chemical diffusion of the chromium atom from matrix to grain boundary (GB) was constructed on the basis of classical nucleation theory, Kolmogorov-Johnson-Mehl-Avrami law, and diffusion theory. The validity of this model was evaluated by comparing the simulated results of the carbide average size and chromium concentration near the GB with the corresponding measured results. A discontinuous factor was introduced based on the relation linking the interdistance between the carbides and the carbide average size; thus, the carbide morphology and chromium concentration could be predicted by this model. According to the results of the experiments and simulations, a carbide discontinuous factor smaller than 2.2 together with the chromium concentration at the GB higher than a critical value (21 wt pct) were essential for the corrosion resistance ability of the alloy, and then some proper heat-treatment conditions were obtained through predicting the value of the two variables. In addition, the effects of the grain size and composition variation on the carbide discontinuous factor and chromium concentration profile were simulated. The results indicated that an intermediate grain size of approximately 31.8 to ~63.5 μm was beneficial for effectively improving the resistance of the alloy to SCC. Simultaneously, the carbon content should be adjusted near 0.02 pct, and the chromium content should be the highest possible in its chemical composition scale.

  19. Notice of Construction for the Magnesium Hydroxide Precipitation Process at the Plutonium Finishing Plant (PFP)

    SciTech Connect

    JANSKY, M.T.

    1999-12-01

    The following description and any attachments and references are provided to the Washington State Department of Health (WDOH), Division of Radiation Protection, Air Emissions & Defense Waste (WAC) 246-247, Radiation Protection-Air Emissions. The WAC 246-247-060, ''Applications, registration, and licensing'', states ''This section describes the information requirements for approval to construct, modify, and operate an emission unit. Any NOC requires the submittal of information listed in Appendix A.'' Appendix A (WAC 246-247-1 10) lists the requirements that must be addressed. Additionally, the following description, attachments and references are provided to the US Environmental Protection Agency (EPA) as an NOC, in accordance with Title 40, Code of Federal Regulations (CFR), Part 61, ''National Emission Standards for Hazardous Air Pollutants.'' The information required for submittal to the EPA is specified in 40 CFR 61.07. The potential emissions from this activity are estimated to provide greater than 0.1 millirem per year total effective dose equivalent (TEDE) to the hypothetical offsite maximally exposed individual (MEI), and commencement is needed within a short time. Therefore, this application also is intended to provide notification of the anticipated date of initial startup in accordance with the requirement listed in 40 CFR 61.09(a)(1), and it is requested that approval of this application also will constitute EPA acceptance of this initial startup notification. Written notification of the actual date of initial startup, in accordance with the requirement listed in 40 CFR 61.09(a)(2) will be provided at a later date. This NOC covers the activities associated with the Construction and operation activities involving the magnesium hydroxide precipitation process of plutonium solutions within the Plutonium Finishing Plant (PFP).

  20. Convective and Stratiform Precipitation Processes and their Relationship to Latent Heating

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo; Lang, Steve; Zeng, Xiping; Shige, Shoichi; Takayabu, Yukari

    2009-01-01

    The global hydrological cycle is central to the Earth's climate system, with rainfall and the physics of its formation acting as the key links in the cycle. Two-thirds of global rainfall occurs in the Tropics. Associated with this rainfall is a vast amount of heat, which is known as latent heat. It arises mainly due to the phase change of water vapor condensing into liquid droplets; three-fourths of the total heat energy available to the Earth's atmosphere comes from tropical rainfall. In addition, fresh water provided by tropical rainfall and its variability exerts a large impact upon the structure and motions of the upper ocean layer. An improved convective -stratiform heating (CSH) algorithm has been developed to obtain the 3D structure of cloud heating over the Tropics based on two sources of information: 1) rainfall information, namely its amount and the fraction due to light rain intensity, observed directly from the Precipitation Radar (PR) on board the TRMM satellite and 2) synthetic cloud physics information obtained from cloud-resolving model (CRM) simulations of cloud systems. The cloud simulations provide details on cloud processes, specifically latent heating, eddy heat flux convergence and radiative heating/cooling, that. are not directly observable by satellite. The new CSH algorithm-derived heating has a noticeably different heating structure over both ocean and land regions compared to the previous CSH algorithm. One of the major differences between new and old algorithms is that the level of maximum cloud heating occurs 1 to 1.5 km lower in the atmosphere in the new algorithm. This can effect the structure of the implied air currents associated with the general circulation of the atmosphere in the Tropics. The new CSH algorithm will be used provide retrieved heating data to other heating algorithms to supplement their performance.

  1. Efficient Separations and Processing Integrated Program (ESP-IP): Technology summary

    SciTech Connect

    Not Available

    1994-02-01

    The Efficient Separations and Processing Integrated Program (ESPIP) was created in 1991 to identify, develop and perfect separations technologies and processes to treat wastes and address environmental problems throughout the DOE Complex. These wastes and environmental problems, located at more than 100 contaminated installations in 36 states and territories, are the result of half a century of nuclear processing activities by DOE and its predecessor organizations. The cost of cleaning up this legacy has been estimated to be of the order of hundreds of billions of dollars, and ESPIP`s origin came with the realization that if new separations and processes can produce even a marginal reduction in cost then billions of dollars will be saved. The ultimate mission for ESPIP, as outlined in the ESPIP Strategic Plan, is: to provide Separations Technologies and Processes (STPS) to process and immobilize a wide spectrum of radioactive and hazardous defense wastes; to coordinate STP research and development efforts within DOE; to explore the potential uses of separated radionuclides; to transfer demonstrated separations and processing technologies developed by DOE to the US industrial sector, and to facilitate competitiveness of US technology and industry in the world market. Technology research and development currently under investigation by ESPIP can be divided into four broad areas: cesium and strontium removal; TRU and other HLW separations; sludge technology, and other technologies.

  2. Atmospheric processes sustaining a multidecadal variation in reconstructed and model-simulated Indian monsoon precipitation during the past half millennium

    NASA Astrophysics Data System (ADS)

    Wu, Qianru

    Analyses of recently reconstructed and model-simulated Indian May-September precipitation disclose a statistically significant multidecadal variation at the frequency of 40-50 year per cycle during the last half millennium. To understand the mechanism of this variation, we examined the energy and dynamic processes in the atmosphere, and the potential forcings from the sea surface temperature (SST) variations around the globe. Comparisons of paleo-SST and the paleo-precipitation simulations suggest that the SST is not a significant forcing of the multidecadal variation found in the Indian monsoon precipitation. Instead, analyses suggest that atmospheric processes characterized by phase differences between the meridional enthalpy gradient and poleward eddy enthalpy transport are important to sustain this variation. In this phase relationship, the meridional enthalpy gradient is strengthened by radiative loss in high latitudes. Driven by this enlarged gradient and associated changes in baroclinicity in the mid-latitude atmosphere, more energy is generated in the tropical and subtropical (monsoon) regions and transported poleward. The monsoon is strengthened to allow more energy being transported poleward. The increased enthalpy transport, in turn, weakens the meridional enthalpy gradient and, subsequently, softens the demand for energy production in the monsoon region. The monsoon weakens and the transport decreases. The variation in monsoon precipitation lags that in the meridional enthalpy gradient, but leads that in the poleward heat transport. This phase relationship and underlining chasing process by the heat transport to the gradient sustain this variation at the multidecadal timescale. This mechanism suggests that atmospheric circulation processes can contribute to multidecadal timescale variations in the Indian monsoon precipitation.

  3. Formation of nanometric HT-LiCoO(2) by a precipitation and aging process in an alcoholic solution.

    PubMed

    Larcher, Dominique; Delobel, Bruno; Dantras-Laffont, Lydia; Simon, Evelyne; Blach, Jean-François; Baudrin, Emmanuel

    2010-12-01

    In this paper, we detailed the formation/evolution of precipitates in alcoholic media containing Co(II+) and Li(+) species, together with the evolution of the composition and structure/texture of the resulting solid phases during the aging process at controlled constant temperature. While the end product is found to be well-crystallized HT-LiCoO(2), its formation is shown to result from a two-step process enlisting the initial fast precipitation of β-HCoO(2) and then its slow dissolution followed by recrystallization of the lithium-containing material. These results were obtained through combined X-ray diffraction, Raman and IR spectroscopy, elemental and oxidation-state analysis, and high-resolution transmission electron microscopy/selected-area electron diffraction observations. Depending on the cationic concentration, the size of the precipitated material can be controlled within the nanometric range. The electrochemical performances of these aged materials are slightly improved compared to those of the directly precipitated ones that we previously reported. The main limitation of these materials remains the presence of surface protons.

  4. Use NU-WRF and GCE Model to Simulate the Precipitation Processes During MC3E Campaign

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo; Wu, Di; Matsui, Toshi; Li, Xiaowen; Zeng, Xiping; Peter-Lidard, Christa; Hou, Arthur

    2012-01-01

    One of major CRM approaches to studying precipitation processes is sometimes referred to as "cloud ensemble modeling". This approach allows many clouds of various sizes and stages of their lifecycles to be present at any given simulation time. Large-scale effects derived from observations are imposed into CRMs as forcing, and cyclic lateral boundaries are used. The advantage of this approach is that model results in terms of rainfall and QI and Q2 usually are in good agreement with observations. In addition, the model results provide cloud statistics that represent different types of clouds/cloud systems during their lifetime (life cycle). The large-scale forcing derived from MC3EI will be used to drive GCE model simulations. The model-simulated results will be compared with observations from MC3E. These GCE model-simulated datasets are especially valuable for LH algorithm developers. In addition, the regional scale model with very high-resolution, NASA Unified WRF is also used to real time forecast during the MC3E campaign to ensure that the precipitation and other meteorological forecasts are available to the flight planning team and to interpret the forecast results in terms of proposed flight scenarios. Post Mission simulations are conducted to examine the sensitivity of initial and lateral boundary conditions to cloud and precipitation processes and rainfall. We will compare model results in terms of precipitation and surface rainfall using GCE model and NU-WRF

  5. Precipitation and microphysical processes observed by three polarimetric X-band radars and ground-based instrumentation during HOPE

    NASA Astrophysics Data System (ADS)

    Xie, Xinxin; Evaristo, Raquel; Simmer, Clemens; Handwerker, Jan; Trömel, Silke

    2016-06-01

    This study presents a first analysis of precipitation and related microphysical processes observed by three polarimetric X-band Doppler radars (BoXPol, JuXPol and KiXPol) in conjunction with a ground-based network of disdrometers, rain gauges and vertically pointing micro rain radars (MRRs) during the High Definition Clouds and Precipitation for advancing Climate Prediction (HD(CP)2) Observational Prototype Experiment (HOPE) during April and May 2013 in Germany. While JuXPol and KiXPol were continuously observing the central HOPE area near Forschungszentrum Jülich at a close distance, BoXPol observed the area from a distance of about 48.5 km. MRRs were deployed in the central HOPE area and one MRR close to BoXPol in Bonn, Germany. Seven disdrometers and three rain gauges providing point precipitation observations were deployed at five locations within a 5 km × 5 km region, while three other disdrometers were collocated with the MRR in Bonn. The daily rainfall accumulation at each rain gauge/disdrometer location estimated from the three X-band polarimetric radar observations showed very good agreement. Accompanying microphysical processes during the evolution of precipitation systems were well captured by the polarimetric X-band radars and corroborated by independent observations from the other ground-based instruments.

  6. Process for separating an ethylenically unsaturated hydrocarbon from a hydrocarbon mixture

    SciTech Connect

    vanEijl, A.T.

    1986-06-24

    A process is described for separating an ethylenically unsaturated hydrocarbon from a hydrocarbon mixture characterized by: (a) distilling a hydrocarbon mixture containing the unsaturated hydrocarbon with an N-(aminoalkyl) piperazine; and (b) separating the amine/hydrocarbon mixture into at least two factions, one of which contains the amine and the unsaturated hydrocarbon.

  7. 40 CFR 63.137 - Process wastewater provisions-oil-water separators.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Process wastewater provisions-oil-water... wastewater provisions—oil-water separators. (a) For each oil-water separator that receives, manages, or treats a Group 1 wastewater stream or a residual removed from a Group 1 wastewater stream, the owner...

  8. Dissolution-precipitation processes governing the carbonation and silicification of the serpentinite sole of the New Caledonia ophiolite

    NASA Astrophysics Data System (ADS)

    Ulrich, Marc; Muñoz, Manuel; Guillot, Stéphane; Cathelineau, Michel; Picard, Christian; Quesnel, Benoit; Boulvais, Philippe; Couteau, Clément

    2014-01-01

    The weathering of mantle peridotite tectonically exposed to the atmosphere leads commonly to natural carbonation processes. Extensive cryptocrystalline magnesite veins and stock-work are widespread in the serpentinite sole of the New Caledonia ophiolite. Silica is systematically associated with magnesite. It is commonly admitted that Mg and Si are released during the laterization of overlying peridotites. Thus, the occurrence of these veins is generally attributed to a per descensum mechanism that involves the infiltration of meteoric waters enriched in dissolved atmospheric CO2. In this study, we investigate serpentinite carbonation processes, and related silicification, based on a detailed petrographic and crystal chemical study of serpentinites. The relationships between serpentine and alteration products are described using an original method for the analysis of micro-X-ray fluorescence images performed at the centimeter scale. Our investigations highlight a carbonation mechanism, together with precipitation of amorphous silica and sepiolite, based on a dissolution-precipitation process. In contrast with the per descensum Mg/Si-enrichment model that is mainly concentrated in rock fractures, dissolution-precipitation process is much more pervasive. Thus, although the texture of rocks remains relatively preserved, this process extends more widely into the rock and may represent a major part of total carbonation of the ophiolite.

  9. Dissolution-precipitation processes governing the carbonation and silicification of the serpentinite sole of the New Caledonia ophiolite

    NASA Astrophysics Data System (ADS)

    Ulrich, M.; Munoz, M.; Guillot, S.; Cathelineau, M.; Picard, C.; Quesnel, B.; Boulvais, P.; Couteau, C.

    2014-12-01

    The weathering of mantle peridotite tectonically exposed to the atmosphere leads commonly to natural carbonation processes. Extensive cryptocrystalline magnesite veins and stock-work are widespread in the serpentinite sole of the New Caledonia ophiolite. Silica is systematically associated with magnesite. It is commonly admitted that Mg and Si are released during the laterization of overlying peridotites. Thus, the occurrence of these veins is generally attributed to a per descensum mechanism that involves the infiltration of meteoric waters enriched in dissolved atmospheric CO2. In this study, we investigate serpentinite carbonation processes, and related silicification, based on a detailed petrographic and crystal chemical study of serpentinites. The relationships between serpentine and alteration products are described using an original method for the analysis of micro-X-ray fluorescence images performed at the centimeter scale. Our investigations highlight a carbonation mechanism, together with precipitation of amorphous silica and sepiolite, based on a dissolution-precipitation process. In contrast with the per descensum Mg/Si-enrichment model that is mainly concentrated in rock fractures, dissolution-precipitation process is much more pervasive. Thus, although the texture of rocks remains relatively preserved, this process extends more widely into the rock and may represent a major part of total carbonation of the ophiolite.

  10. METHOD OF SEPARATING NEPTUNIUM

    DOEpatents

    Seaborg, G.T.

    1961-10-24

    plutonium in an aqueous solution containing sulfate ions. The process consists of contacting the solution with an alkali metal bromate, digesting the resulting mixture at 15 to 25 deg C for a period of time not more than that required to oxidize the neptunium, adding lanthanum ions and fluoride ions, and separating the plutonium-containing precipitate thus formed from the supernatant solution. (AEC)

  11. Pervaporation & Vapor Permeation Membrane Processes for the Selective Separation of Liquid and Vapor Mixtures

    EPA Science Inventory

    Pervaporation and vapor permeation are membrane-based processes which have been proposed as alternatives to conventional separation technologies. Applications range from organic solvent removal from water, ethanol or butanol recovery from dilute fermentation broths, solvent/biofu...

  12. Pervaporation and Vapor Permeation Tutorial: Membrane Processes for the Selective Separation of Liquid and Vapor Mixtures

    EPA Science Inventory

    Pervaporation and vapor permeation are membrane-based processes proposed as alternatives to conventional separation technologies. Applications range from organic solvent removal from water, ethanol or butanol recovery from fermentation broths, solvent/biofuel dehydration to meet ...

  13. Comprehensive understanding of nano-sized particle separation processes using nanoparticle tracking analysis.

    PubMed

    Lawler, Desmond F; Youn, Sungmin; Zhu, Tongren; Kim, Ijung; Lau, Boris L T

    2015-01-01

    The understanding of nano-sized particle separation processes has been limited by difficulties of nanoparticle characterization. In this study, nanoparticle tracking analysis (NTA) was deployed to evaluate the absolute particle size distributions in laboratory scale flocculation and filtration experiments with silver nanoparticles. The results from NTA were consistent with standard theories of particle destabilization and transport. Direct observations of changes in absolute particle size distributions from NTA enhance both qualitative and quantitative understanding of particle separation processes of nano-sized particles.

  14. Process for the production of ultrahigh purity silane with recycle from separation columns

    NASA Technical Reports Server (NTRS)

    Coleman, Larry M. (Inventor)

    1982-01-01

    Tri- and dichlorosilanes formed by hydrogenation in the course of the reaction of metallurgical silicon, hydrogen and recycle silicon tetrachloride are employed as feed into a separation column arrangement of sequential separation columns and redistribution reactors which processes the feed into ultrahigh purity silane and recycle silicon tetrachloride. A slip stream is removed from the bottom of two sequential columns and added to the recycle silicon tetrachloride process stream causing impurities in the slip streams to be subjected to reactions in the hydrogenation step whereby waste materials can be formed and readily separated.

  15. Process for the production of ultrahigh purity silane with recycle from separation columns

    DOEpatents

    Coleman, Larry M.

    1982-07-20

    Tri- and dichlorosilanes formed by hydrogenation in the course of the reaction of metallurgical silicon, hydrogen and recycle silicon tetrachloride are employed as feed into a separation column arrangement of sequential separation columns and redistribution reactors which processes the feed into ultrahigh purity silane and recycle silicon tetrachloride. A slip stream is removed from the bottom of two sequential columns and added to the recycle silicon tetrachloride process stream causing impurities in the slip streams to be subjected to reactions in the hydrogenation step whereby waste materials can be formed and readily separated.

  16. Artery-vein separation via MRA--an image processing approach.

    PubMed

    Lei, T; Udupa, J K; Saha, P K; Odhner, D

    2001-08-01

    This paper presents a near-automatic process for separating vessels from background and other clutter as well as for separating arteries and veins in contrast-enhanced magnetic resonance angiographic (CE-MRA) image data, and an optimal method for three-dimensional visualization of vascular structures. The separation process utilizes fuzzy connected object delineation principles and algorithms. The first step of this separation process is the segmentation of the entire vessel structure from the background and other clutter via absolute fuzzy connectedness. The second step is to separate artery from vein within this entire vessel structure via iterative relative fuzzy connectedness. After seed voxels are specified inside artery and vein in the CE-MRA image, the small regions of the bigger aspects of artery and vein are separated in the initial iterations, and further detailed aspects of artery and vein are included in later iterations. At each iteration, the artery and vein compete among themselves to grab membership of each voxel in the vessel structure based on the relative strength of connectedness of the voxel in the artery and vein. This approach has been implemented in a software package for routine use in a clinical setting and tested on 133 CE-MRA studies of the pelvic region and two studies of the carotid system from six different hospitals. In all studies, unified parameter settings produced correct artery-vein separation. When compared with manual segmentation/separation, our algorithms were able to separate higher order branches, and therefore produced vastly more details in the segmented vascular structure. The total operator and computer time taken per study is on the average about 4.5 min. To date, this technique seems to be the only image processing approach that can be routinely applied for artery and vein separation.

  17. The effect of polymer-surfactant interaction on the rheological properties of surfactant enhanced alkaline flooding formulations. [Phase separation, precipitation and viscosity loss

    SciTech Connect

    French, T.R.; Josephson, C.B.

    1993-02-01

    Surfactant-enhanced, lower pH (weak) alkaline chemicals are effective for mobilizing residual oil. Polymer is used for mobility control because if mobility control is lost, then oil recovery is reduced. The ability to maintain mobility control during surfactant-alkaline flooding can be adversely affected by chemical interaction. In this work, interaction between polymers and surfactants was shown to be affected by pH, ionic strength, crude oil, and the properties of the polymers and surfactants. Polymer-surfactant interaction (phase separation, precipitation, and viscosity loss) occurred between most of the polymers and surfactants that were tested. Polymer-surfactant interaction is difficult to eliminate, and no method was found for completely eliminating interaction. Polymer-surfactant interaction occurred at optimal salinity and below optimal salinity. Polymer-surfactant interaction had an adverse effect on polymer rheology; however, the adverse effect of interaction on polymer rheology was lessened when oil was present. Increasing the pH of chemical systems further reduced the adverse effects of interaction on polymer rheology.

  18. A pilot-scale study of struvite precipitation in a stirred tank reactor: conditions influencing the process.

    PubMed

    Pastor, L; Mangin, D; Barat, R; Seco, A

    2008-09-01

    Currently, the two most developed techniques for recovering phosphorus from wastewater consist of the formation of calcium phosphates and struvite (MgNH(4)PO(4).6H(2)O). In this work the influence of the operational conditions on the struvite precipitation process (pH in the reactor, hydraulic retention time, and magnesium:phosphorus, nitrogen:phosphorus, and calcium:magnesium molar ratios) have been studied. Twenty-three experiments with artificial wastewater were performed in a stirred reactor. In order to obtain the pH value maintenance during the crystallization process, a fuzzy logic control has been developed. High phosphorus removal efficiencies were reliably achieved precipitating the struvite as easily dried crystals or as pellets made up of agglomerated crystals.

  19. DEMONSTRATION OF THE NEXT-GENERATION TCAP HYDROGEN ISOTOPE SEPARATION PROCESS

    SciTech Connect

    Heung, L; Henry Sessions, H; Steve Xiao, S; Heather Mentzer, H

    2009-01-09

    The first generation of TCAP hydrogen isotope separation process has been in service for tritium separation at the Savannah River Site since 1994. To prepare for replacement, a next-generation TCAP process has been developed. This new process simplifies the column design and reduces the equipment requirements of the thermal cycling system. An experimental twelve-meter column was fabricated and installed in the laboratory to demonstrate its performance. This new design and its initial test results were presented at the 8th International Conference on Tritium Science and Technology and published in the proceedings. We have since completed the startup and demonstration the separation of protium and deuterium in the experimental unit. The unit has been operated for more than 200 cycles. A feed of 25% deuterium in protium was separated into two streams each better than 99.7% purity.

  20. Processes and mechanisms of persistent extreme precipitation events in East China

    NASA Astrophysics Data System (ADS)

    Zhai, Panmao; Chen, Yang

    2014-11-01

    This study mainly presents recent progresses on persistent extreme precipitation events (PEPEs) in East China. A definition focusing both persistence and extremity of daily precipitation is firstly proposed. An identification method for quasi-stationary regional PEPEs is then designed. By utilizing the identified PEPEs in East China, typical circulation configurations from the lower to the upper troposphere are confirmed, followed by investigations of synoptic precursors for key components with lead time of 1-2 weeks. Two characteristic circulation patterns responsible for PEPEs in East China are identified: a double blocking high type and a single blocking high type. They may account for occurrence of nearly 80% PEPEs during last 60 years. For double blocking high type, about two weeks prior to PEPEs, two blockings developed and progressed towards the Ural Mountains and the Sea of Okhotsk, respectively. A northwestward progressive anomalous anticyclone conveying abundant moisture and eastward-extended South Asia High favoring divergence can be detected about one week in advance. A dominant summertime teleconnection over East Asia, East Asia/ Pacific (EAP) pattern, is deemed as another typical regime inducing PEPEs in the East China. Key elements of the EAP pattern initiated westward movement since one week prior to PEPEs. Eastward energy dispersion and poleward energy dispersion contributed to early development and subsequent maintenance of this teleconnection pattern, respectively. These typical circulation patterns and significant precursors may offer local forecasters some useful clues in identifying and predicting such high-impact precipitation events about 1-2 weeks in advance.

  1. Synthesis of strontium hexaferrite nanoparticles prepared using co-precipitation method and microemulsion processing

    NASA Astrophysics Data System (ADS)

    Drmota, A.; Žnidaršič, A.; Košak, A.

    2010-01-01

    Strontium hexaferrite (SrFe12O19) nanoparticles have been prepared with co-precipitation in aqueous solutions and precipitation in microemulsion system water/SDS/n-butanol/cyclohexane, using iron and strontium nitrates in different molar rations as a starting materials. The mixed Sr2+, Fe3+ hydroxide precursors obtained during the reaction between corresponding metal nitrates and tetramethylammonium hydroxide (TMAH), which served as a precipitating reagent, were calcined in a wide temperature range, from 350 °C to 1000 °C in a static air atmosphere. The influence of the Sr2+/Fe3+ molar ratio and the calcination temperature to the chemistry of the product formation, its crystallite size, morphology and magnetic properties were investigated. It was found that the formation of single phase SrFe12O19 with relatively high specific magnetization (54 Am2/kg) was achieved at the Sr2+/Fe3+ molar ration of 6.4 and calcination at 800 °C for 3h with heating/cooling rate 5 °C/min. The prepared powders were characterized using X-ray diffractometry (XRD) and specific surface area measurements (BET). The specific magnetization (DSM-10, magneto-susceptometer) of the prepared samples was measured.

  2. Process for separating and recovering an anionic dye from an aqueous solution

    DOEpatents

    Rogers, R.; Horwitz, E.P.; Bond, A.H.

    1998-01-13

    A solid/liquid phase process for the separation and recovery of an anionic dye from an aqueous solution is disclosed. The solid phase comprises separation particles having surface-bonded poly(ethylene glycol) groups, whereas the aqueous solution from which the anionic dye molecules are separated contains a poly(ethylene glycol) liquid/liquid biphase-forming amount of a dissolved lyotropic salt. After contact between the aqueous solution and separation particles, the anionic dye is bound to the particles. The bound anionic dye molecules are freed from the separation particles by contacting the anionic dye-bound particles with an aqueous solution that does not contain a poly(ethylene glycol) liquid/liquid biphase-forming amount of a dissolved lyotropic salt to form an aqueous anionic dye solution whose anionic dye concentration is preferably higher than that of the initial dye-containing solution. 7 figs.

  3. Process for separating and recovering an anionic dye from an aqueous solution

    DOEpatents

    Rogers, Robin; Horwitz, E. Philip; Bond, Andrew H.

    1998-01-01

    A solid/liquid phase process for the separation and recovery of an anionic dye from an aqueous solution is disclosed. The solid phase comprises separation particles having surface-bonded poly(ethylene glycol) groups, whereas the aqueous solution from which the anionic dye molecules are separated contains a poly(ethylene glycol) liquid/liquid biphase-forming amount of a dissolved lyotropic salt. After contact between the aqueous solution and separation particles, the anionic dye is bound to the particles. The bound anionic dye molecules are freed from the separation particles by contacting the anionic dye-bound particles with an aqueous solution that does not contain a poly(ethylene glycol) liquid/liquid biphase-forming amount of a dissolved lyotropic salt to form an aqueous anionic dye solution whose anionic dye concentration is preferably higher than that of the initial dye-containing solution.

  4. Early Attachment-Figure Separation and Increased Risk for Later Depression: Potential Mediation by Proinflammatory Processes

    PubMed Central

    Hennessy, Michael B.; Deak, Terrence; Schiml-Webb, Patricia A.

    2009-01-01

    Early maternal separation and other disruptions of attachment relations are known to increase risk for the later onset of depressive illness in vulnerable individuals. It is suggested here that sensitization involving proinflammatory processes may contribute to this effect. This argument is based on: (1) current notions of the role of proinflammatory cytokines in depressive illness; (2) evidence that proinflammatory cytokines mediate depressive-like behavior during separation in a rodent model of infant attachment; and (3) comparisons of the effects of early proinflammatory activation versus maternal separation on later proinflammatory activity and biobehavioral processes related to depression. The possible interaction of proinflammatory processes and corticotropin-releasing factor in the sensitization process is discussed. PMID:20359585

  5. Process for coal liquefaction by separation of entrained gases from slurry exiting staged dissolvers

    DOEpatents

    Givens, Edwin N.; Ying, David H. S.

    1983-01-01

    There is described an improved liquefaction process by which coal is converted to a low ash and low sulfur carbonaceous material that can be used as a fuel in an environmentally acceptable manner without costly gas scrubbing equipment. In the process, coal is slurried with a solvent, passed through a preheater and at least two dissolvers in series in the presence of hydrogen-rich gases at elevated temperatures and pressures. Solids, including mineral ash and unconverted coal macerals are separated from the condensed dissolver effluent. In accordance with the improved process, fresh hydrogen is fed to each dissolver and the entrained gas from each dissolver is separated from the slurry phase and removed from the reactor system before the condensed phase is passed to the next dissolver in the series. In accordance with another process, the feeds to the dissolvers are such that the top of each downstream dissolver is used as a gas-liquid separator.

  6. CORROSION ISSUES ASSOCIATED WITH AUSTENITIC STAINLESS STEEL COMPONENTS USED IN NUCLEAR MATERIALS EXTRACTION AND SEPARATION PROCESSES

    SciTech Connect

    Mickalonis, J.; Louthan, M.; Sindelar, R.

    2012-12-17

    This paper illustrated the magnitude of the systems, structures and components used at the Savannah River Site for nuclear materials extraction and separation processes. Corrosion issues, including stress corrosion cracking, pitting, crevice corrosion and other corrosion induced degradation processes are discussed and corrosion mitigation strategies such as a chloride exclusion program and corrosion release testing are also discussed.

  7. Analysis of the operation of a packed rectifying column in the process of binary mixture separation

    NASA Astrophysics Data System (ADS)

    Moshinskii, A. I.

    2013-09-01

    On the basis of a continuum mathematical model, the operation of a packed rectifying column in the stationary (continuous) and nonstationary (periodic) regimes in the process of binary mixture separation under certain conditions has been analyzed. We have considered examples of the realization of the above process, for which analytical expressions convenient for calculations have been obtained.

  8. Temporal Integration in Face Perception: Evidence of Configural Processing of Temporally Separated Face Parts

    ERIC Educational Resources Information Center

    Anaki, David; Boyd, Jennifer; Moscovitch, Morris

    2007-01-01

    Temporal integration is the process by which temporally separated visual components are combined into a unified representation. Although this process has been studied in object recognition, little is known about temporal integration in face perception and recognition. In the present study, the authors investigated the characteristics and time…

  9. Pulsed-Neutron-Gamma (PNG) saturation monitoring at the Ketzin pilot site considering displacement and evaporation/precipitation processes

    NASA Astrophysics Data System (ADS)

    Baumann, Gunther; Henninges, Jan

    2013-04-01

    The storage of carbon dioxide (CO2) in saline aquifers is a promising option to reduce emissions of greenhouse gases to the atmosphere and to mitigate global climate change. During the proposed CO2 injection process, application of suitable techniques for monitoring of the induced changes in the subsurface is required. Existing models for the spreading of the CO2, as well as mixing of the different fluids associated with saturation changes or resulting issues from mutual solubility between brine and CO2, need to be checked. For well logging in cased boreholes, which would be the standard situation encountered under the given conditions, only a limited number of techniques like pulsed neutron-gamma (PNG) logging are applicable. The PNG technique uses controlled neutron bursts, which interact with the nuclei of the surrounding borehole and formation. Due to the collision with these neutrons, atoms from the surrounding environment emit gamma rays. The main PNG derived parameter is the capture cross section (Σ) which is derived from the decline of gamma rays with time from neutron capture processes. The high Σ contrast between brine and CO2 results in a high sensitivity to evaluate saturation changes. This makes PNG monitoring favourable for saturation profiling especially in time-lapse mode. Previously, the conventional PNG saturation model based on a displacement process has been used for PNG interpretation in different CO2 storage projects in saline aquifers. But in addition to the displacement process, the mutual solubility between brine and CO2 adds further complex processes like evaporation and salt precipitation, which are not considered in PNG saturation models. These evaporation and precipitation processes are relevant in the vicinity of an injection well, where dry CO2 enters the reservoir. The Σ brine value depends strongly on the brine salinity e.g. its chlorine content which makes PNG measurements suitable for evaporation and salt precipitation

  10. SEPARATION OF PLUTONIUM FROM FISSION PRODUCTS BY A COLLOID REMOVAL PROCESS

    DOEpatents

    Schubert, J.

    1960-05-24

    A method is given for separating plutonium from uranium fission products. An acidic aqueous solution containing plutonium and uranium fission products is subjected to a process for separating ionic values from colloidal matter suspended therein while the pH of the solution is maintained between 0 and 4. Certain of the fission products, and in particular, zirconium, niobium, lanthanum, and barium are in a colloidal state within this pH range, while plutonium remains in an ionic form, Dialysis, ultracontrifugation, and ultrafiltration are suitable methods of separating plutonium ions from the colloids.

  11. Evaluation, engineering and development of advanced cyclone processes. Final separating media evaluation and test report (FSMER)

    SciTech Connect

    1995-05-19

    {open_quotes}Evaluation Engineering and Development of Advanced Cyclone Processes{close_quotes} is one of the DOE-PETC sponsored advanced coal cleaning projects, which share a number of specific goals. These goals are to produce a 6% ash product, reject 85% of the parent coal`s pyritic sulfur, recover 85% of the parent coal`s Btu value, and provide products that are less than 30% moisture. The process in this project, as the name implies, relies on a cyclone or cyclonic separator to achieve physical beneficiation based on the gravimetric differences between clean coal and its impurities. Just as important as the cyclonic separator, if not more so, is the selection of a parting liquid or medium for use in the separator. Selection of a separating medium is regarded as a significant portion of the project because it has a profound impact on the required unit operations, the performance of the separator, and economics of the process. The choice of medium especially influences selection of media recovery system(s), and the characteristics of clean coal and refuse products. Since medium selection is such an important aspect of the project, portions of the project are dedicated to the study, evaluation, and selection of the most desirable medium. Though separators are an important component, this project initially focused on media study, rather than the separators themselves. In coal processing, discussion of media requires description of the handling and recovery system(s), separation performance, interaction with coal, cost, and health, environmental and safety issues. In order to be effective, a candidate must perform well in all of these categories.

  12. Fate of 17β-Estradiol as a model estrogen in source separated urine during integrated chemical P recovery and treatment using partial nitritation-anammox process.

    PubMed

    Huang, Pei; Mukherji, Sachiyo T; Wu, Sha; Muller, James; Goel, Ramesh

    2016-10-15

    Recently, research on source separation followed by the treatment of urine and/or resource recovery from human urine has shown promise as an emerging management strategy. Despite contributing only 1% of the total volume of wastewater, human urine contributes about 80% of the nitrogen, 70% of the potassium, and up to 50% of the total phosphorus in wastewater. It is also a known fact that many of the micropollutants, especially selected estrogens, get into municipal wastewater through urine excretion. In this research, we investigated the fate of 17β-estradiol (E2) as a model estrogen during struvite precipitation from synthetic urine followed by the treatment of urine using a partial nitritation-anammox (PN/A) system. Single-stage and two-stage suspended growth PN/A configurations were used to remove the nitrogen in urine after struvite precipitation. The results showed an almost 95% phosphorous and 5% nitrogen recovery/removal from the synthetic urine due to struvite precipitation. The single and two stage PN/A processes were able to remove around 50% and 75% of ammonia and nitrogen present in the post struvite urine solution, respectively. After struvite precipitation, more than 95% of the E2 remained in solution and the transformation of E2 to E1 happened during urine storage. Most of the E2 removal that occurred during the PN/A process was due to sorption on the biomass and biodegradation (transformation of E2 to E1, and slow degradation of E1 to other metabolites). These results demonstrate that a combination of chemical and biological unit processes will be needed to recover and manage nutrients in source separated urine. PMID:27566951

  13. Nuclear criticality safety bounding analysis for the in-tank-precipitation (ITP) process, impacted by fissile isotopic weight fractions

    SciTech Connect

    Bess, C.E.

    1994-04-22

    The In-Tank Precipitation process (ITP) receives High Level Waste (HLW) supernatant liquid containing radionuclides in waste processing tank 48H. Sodium tetraphenylborate, NaTPB, and monosodium titanate (MST), NaTi{sub 2}O{sub 5}H, are added for removal of radioactive Cs and Sr, respectively. In addition to removal of radio-strontium, MST will also remove plutonium and uranium. The majority of the feed solutions to ITP will come from the dissolution of supernate that had been concentrated by evaporation to a crystallized salt form, commonly referred to as saltcake. The concern for criticality safety arises from the adsorption of U and Pt onto MST. If sufficient mass and optimum conditions are achieved then criticality is credible. The concentration of u and Pt from solution into the smaller volume of precipitate represents a concern for criticality. This report supplements WSRC-TR-93-171, Nuclear Criticality Safety Bounding Analysis For The In-Tank-Precipitation (ITP) Process. Criticality safety in ITP can be analyzed by two bounding conditions: (1) the minimum safe ratio of MST to fissionable material and (2) the maximum fissionable material adsorption capacity of the MST. Calculations have provided the first bounding condition and experimental analysis has established the second. This report combines these conditions with canyon facility data to evaluate the potential for criticality in the ITP process due to the adsorption of the fissionable material from solution. In addition, this report analyzes the potential impact of increased U loading onto MST. Results of this analysis demonstrate a greater safety margin for ITP operations than the previous analysis. This report further demonstrates that the potential for criticality in the ITP process due to adsorption of fissionable material by MST is not credible.

  14. Magnetically assisted chemical separation (MACS) process: Preparation and optimization of particles for removal of transuranic elements

    SciTech Connect

    Nunez, L.; Kaminski, M.; Bradley, C.; Buchholz, B.A.; Aase, S.B.; Tuazon, H.E.; Vandegrift, G.F.; Landsberger, S.

    1995-05-01

    The Magnetically Assisted Chemical Separation (MACS) process combines the selectivity afforded by solvent extractants with magnetic separation by using specially coated magnetic particles to provide a more efficient chemical separation of transuranic (TRU) elements, other radionuclides, and heavy metals from waste streams. Development of the MACS process uses chemical and physical techniques to elucidate the properties of particle coatings and the extent of radiolytic and chemical damage to the particles, and to optimize the stages of loading, extraction, and particle regeneration. This report describes the development of a separation process for TRU elements from various high-level waste streams. Polymer-coated ferromagnetic particles with an adsorbed layer of octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) diluted with tributyl phosphate (TBP) were evaluated for use in the separation and recovery of americium and plutonium from nuclear waste solutions. Due to their chemical nature, these extractants selectively complex americium and plutonium contaminants onto the particles, which can then be recovered from the solution by using a magnet. The partition coefficients were larger than those expected based on liquid[liquid extractions, and the extraction proceeded with rapid kinetics. Extractants were stripped from the particles with alcohols and 400-fold volume reductions were achieved. Particles were more sensitive to acid hydrolysis than to radiolysis. Overall, the optimization of a suitable NMCS particle for TRU separation was achieved under simulant conditions, and a MACS unit is currently being designed for an in-lab demonstration.

  15. Separating the Effects of Northern Hemisphere Ice-Sheets, CO2 Concentrations and Orbital Parameters on Global Precipitation During the Late Pleistocene Glacial Cycles

    NASA Astrophysics Data System (ADS)

    Elison Timm, O.; Friedrich, T.; Timmermann, A.; Ganopolski, A.

    2015-12-01

    Global-scale changes in the hydrological cycle have been reconstructed in many parts of the world using various archives of proxy information. The signals found in proxies allow us to study the complex response of the global hydrological cycle to the combined forcing and feedback mechanisms. However, it remains a challenge to attribute the observed variations to specific causes, in particular, it is difficult to distinguish CO2 and ice-sheet response in time series. Here, we present new results from a set of transient paleoclimate simulation of the last eight glacial cycles (784,000 years) using accelerated forcing. In order to isolate the ice-sheet forcing from the CO2 -driven response and orbital forcing, we made use of additional transient experiments with varying forcing combinations covering the last 408,000 years: (a) keeping CO2 concentrations constant, (b) keeping the ice-sheet fixed, (c) orbital forcing only. The simulations show that orbital forcing has strongest impact in the tropical and subtropical regions. The northern hemisphere ice-sheets stamp a characteristic spatial footprint on the global precipitation variability. The ice-sheets mainly affect the extratropical northern hemisphere, but the cone of influence extends further into the North African monsoon regions, and to a weaker extent into the Asian monsoon. In an attempt to validate our model-specific results we compared our results with existing hydrological paleo proxy records. Despite the growing number of proxy archives, the aim to identify the ice-sheet influence in spatially limited networks of proxy time series remains as challenge. More records that cover at least two full glacial cycles could significantly increase the signal separation. In conclusion, our results suggest that the northern hemisphere ice-sheets played an important role in modulating the global hydrological cycle.

  16. Effect of antiscalants on precipitation of an RO concentrate: metals precipitated and particle characteristics for several water compositions.

    PubMed

    Greenlee, Lauren F; Testa, Fabrice; Lawler, Desmond F; Freeman, Benny D; Moulin, Philippe

    2010-04-01

    Inland brackish water reverse osmosis (RO) is economically and technically limited by the large volume of salty waste (concentrate) produced. The use of a controlled precipitation step, followed by solid/liquid separation (filtration), has emerged as a promising side-stream treatment process to treat reverse osmosis concentrate and increase overall system recovery. The addition of antiscalants to the RO feed prevents precipitation within the membrane system but might have a deleterious effect on a concentrate treatment process that uses precipitation to remove problematic precipitates. The effects of antiscalant type and concentration on salt precipitation and precipitate particle morphology were evaluated for several water compositions. The primary precipitate for the synthetic brackish waters tested was calcium carbonate; the presence of magnesium, sulfate, minor ions, and antiscalant compounds affected the amount of calcium precipitated, as well as the phases of calcium carbonate formed during precipitation. Addition of antiscalant decreased calcium precipitation but increased incorporation of magnesium and sulfate into precipitating calcium carbonate. Antiscalants prevented the growth of nucleated precipitates, resulting in the formation of small (100-200 nm diameter) particles, as well as larger (6-10 microm) particles. Elemental analysis revealed changes in composition and calcium carbonate polymorph with antiscalant addition and antiscalant type. Results indicate that the presence of antiscalants does reduce the extent of calcium precipitation and can worsen subsequent filtration performance.

  17. Effect of antiscalants on precipitation of an RO concentrate: metals precipitated and particle characteristics for several water compositions.

    PubMed

    Greenlee, Lauren F; Testa, Fabrice; Lawler, Desmond F; Freeman, Benny D; Moulin, Philippe

    2010-04-01

    Inland brackish water reverse osmosis (RO) is economically and technically limited by the large volume of salty waste (concentrate) produced. The use of a controlled precipitation step, followed by solid/liquid separation (filtration), has emerged as a promising side-stream treatment process to treat reverse osmosis concentrate and increase overall system recovery. The addition of antiscalants to the RO feed prevents precipitation within the membrane system but might have a deleterious effect on a concentrate treatment process that uses precipitation to remove problematic precipitates. The effects of antiscalant type and concentration on salt precipitation and precipitate particle morphology were evaluated for several water compositions. The primary precipitate for the synthetic brackish waters tested was calcium carbonate; the presence of magnesium, sulfate, minor ions, and antiscalant compounds affected the amount of calcium precipitated, as well as the phases of calcium carbonate formed during precipitation. Addition of antiscalant decreased calcium precipitation but increased incorporation of magnesium and sulfate into precipitating calcium carbonate. Antiscalants prevented the growth of nucleated precipitates, resulting in the formation of small (100-200 nm diameter) particles, as well as larger (6-10 microm) particles. Elemental analysis revealed changes in composition and calcium carbonate polymorph with antiscalant addition and antiscalant type. Results indicate that the presence of antiscalants does reduce the extent of calcium precipitation and can worsen subsequent filtration performance. PMID:20172582

  18. Audio signal separation via a combination procedure of time-reversal and deconvolution process

    NASA Astrophysics Data System (ADS)

    Wu, Bo-Hsien; Too, Gee-Pinn; Lee, Sony

    2010-07-01

    Time-reversal method (TRM) is based on principle of reciprocity of sound by propagating of a reversal signal in time series to compensate distortion due to path effect in propagation and to focus the signal at the original source location. In recent years, the technique has been applied in optics, ultrasound and underwater acoustic communication. In the present study, a procedure for audio signal separation is developed by applying time-reversal and deconvolution process. The procedure separates sources from audio signal in time domain. The advantages of this procedure are to separate a specific source from a combination signal of multiple sources and to reduce reverberation effectively. Finally, a deconvolution process of finding impulse response function (IRF) is developed where single value decomposition (SVD) and Tikhonov regularization process are used to solve ill-conditioned and singular linear systems. In addition, the effect of signal-to-noise ratio (SNR) and number of array sensors are discussed in details.

  19. Membrane loop process for separating carbon dioxide for use in gaseous form from flue gas

    SciTech Connect

    Wijmans, Johannes G; Baker, Richard W; Merkel, Timothy C

    2014-10-07

    The invention is a process involving membrane-based gas separation for separating and recovering carbon dioxide emissions from combustion processes in partially concentrated form, and then transporting the carbon dioxide and using or storing it in a confined manner without concentrating it to high purity. The process of the invention involves building up the concentration of carbon dioxide in a gas flow loop between the combustion step and a membrane separation step. A portion of the carbon dioxide-enriched gas can then be withdrawn from this loop and transported, without the need to liquefy the gas or otherwise create a high-purity stream, to a destination where it is used or confined, preferably in an environmentally benign manner.

  20. Microstructure and Crystallographic Texture Evolution During the Friction-Stir Processing of a Precipitation-Hardenable Aluminum Alloy

    NASA Astrophysics Data System (ADS)

    Nadammal, Naresh; Kailas, Satish V.; Szpunar, Jerzy; Suwas, Satyam

    2015-05-01

    Friction-stir processing (FSP) has been proven as a successful method for the grain refinement of high-strength aluminum alloys. The most important attributes of this process are the fine-grain microstructure and characteristic texture, which impart suitable properties in the as-processed material. In the current work, FSP of the precipitation-hardenable aluminum alloy 2219 has been carried out and the consequent evolution of microstructure and texture has been studied. The as-processed materials were characterized using electron back-scattered diffraction, x-ray diffraction, and electron probe microanalysis. Onion-ring formation was observed in the nugget zone, which has been found to be related to the precipitation response and crystallographic texture of the alloy. Texture development in the alloy has been attributed to the combined effect of shear deformation and dynamic recrystallization. The texture was found heterogeneous even within the nugget zone. A microtexture analysis revealed the dominance of shear texture components, with C component at the top of nugget zone and the B and A2* components in the middle and bottom. The bulk texture measurement in the nugget zone revealed a dominant C component. The development of a weaker texture along with the presence of some large particles in the nugget zone indicates particle-stimulated nucleation as the dominant nucleation mechanism during FSP. Grain growth follows the Burke and Turnbull mechanism and geometrical coalescence.

  1. Critical material and process issues for CO2 separation from coal-powered plants

    NASA Astrophysics Data System (ADS)

    Liu, Wei; King, David; Liu, Jun; Johnson, Brad; Wang, Yong; Yang, Zhenguo

    2009-04-01

    Concentrating CO2 from the dilute coal combustion or gasification gas stream to a level suitable for sequestration purposes represents a major cost factor to curtail CO2 emissions by capture and sequestration. This paper provides a short review of CO2 capture incentives, current separation processes, and research progress of various new technologies. Scientifically, CO2 can be separated from a gas mixture by all the methods reviewed in this work: distillation, absorption, adsorption, gas/solid reaction, membrane, electrochemical pump, hydrate formation, etc. The challenge lies in practical feasibility and ultimately the cost. Important material issues and their impacts to the process viability will be discussed.

  2. Simulation of a Novel Single-column Cryogenic Air Separation Process Using LNG Cold Energy

    NASA Astrophysics Data System (ADS)

    Jieyu, Zheng; Yanzhong, Li; Guangpeng, Li; Biao, Si

    In this paper, a novel single-column air separation process is proposed with the implementation of heat pump technique and introduction of LNG coldenergy. The proposed process is verifiedand optimized through simulation on the Aspen Hysys® platform. Simulation results reveal that thepower consumption per unit mass of liquid productis around 0.218 kWh/kg, and the total exergy efficiency of the systemis 0.575. According to the latest literatures, an energy saving of 39.1% is achieved compared with those using conventional double-column air separation units.The introduction of LNG cold energy is an effective way to increase the system efficiency.

  3. Comprehensive understanding of nano-sized particle separation processes using nanoparticle tracking analysis.

    PubMed

    Lawler, Desmond F; Youn, Sungmin; Zhu, Tongren; Kim, Ijung; Lau, Boris L T

    2015-01-01

    The understanding of nano-sized particle separation processes has been limited by difficulties of nanoparticle characterization. In this study, nanoparticle tracking analysis (NTA) was deployed to evaluate the absolute particle size distributions in laboratory scale flocculation and filtration experiments with silver nanoparticles. The results from NTA were consistent with standard theories of particle destabilization and transport. Direct observations of changes in absolute particle size distributions from NTA enhance both qualitative and quantitative understanding of particle separation processes of nano-sized particles. PMID:26676021

  4. Documents containing operating data for Hanford separations processes, 1944--1972. Hanford Environmental Dose Reconstruction Project

    SciTech Connect

    Gydesen, S.P.

    1992-09-01

    The purpose of this letter report is to identify documents that record batch, daily, or selected monthly separations processes operating information at the Hanford Site for the years 1944-1972. The information found in these documents is needed to develop the source terms necessary to make dose estimates. The documents have been identified, located, declassified if necessary, evaluated, and made available to the HEDR Project in general, the HEDR Task 03 (Source Terms) in particular, and the public. Complete bibliographic citations and some sample pages from the Hanford separations processes documents are included.

  5. Documents containing operating data for Hanford separations processes, 1944--1972

    SciTech Connect

    Gydesen, S.P.

    1992-09-01

    The purpose of this letter report is to identify documents that record batch, daily, or selected monthly separations processes operating information at the Hanford Site for the years 1944-1972. The information found in these documents is needed to develop the source terms necessary to make dose estimates. The documents have been identified, located, declassified if necessary, evaluated, and made available to the HEDR Project in general, the HEDR Task 03 (Source Terms) in particular, and the public. Complete bibliographic citations and some sample pages from the Hanford separations processes documents are included.

  6. Method for improving separation of carbohydrates from wood pulping and wood or biomass hydrolysis liquors

    DOEpatents

    Griffith, William Louis; Compere, Alicia Lucille; Leitten, Jr., Carl Frederick

    2010-04-20

    A method for separating carbohydrates from pulping liquors includes the steps of providing a wood pulping or wood or biomass hydrolysis pulping liquor having lignin therein, and mixing the liquor with an acid or a gas which forms an acid upon contact with water to initiate precipitation of carbohydrate to begin formation of a precipitate. During precipitation, at least one long chain carboxylated carbohydrate and at least one cationic polymer, such as a polyamine or polyimine are added, wherein the precipitate aggregates into larger precipitate structures. Carbohydrate gel precipitates are then selectively removed from the larger precipitate structures. The method process yields both a carbohydrate precipitate and a high purity lignin.

  7. The Impact of Aerosols on Cloud and Precipitation Processes: Cloud-Resolving Model Simulations

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo; Li, Xiaowen; Khain, Alexander; Matsui, Toshihisa; Lang, Stephen; Simpson, Joanne

    2012-01-01

    Recently, a detailed spectral-bin microphysical scheme was implemented into the Goddard Cumulus Ensemble (GCE) model. Atmospheric aerosols are also described using number density size-distribution functions. A spectral-bin microphysical model is very expensive from a computational point of view and has only been implemented into the 2D version of the GCE at the present time. The model is tested by studying the evolution of deep tropical clouds in the west Pacific warm pool region and summertime convection over a mid-latitude continent with different concentrations of CCN: a low clean concentration and a high dirty concentration. The impact of atmospheric aerosol concentration on cloud and precipitation will be investigated.

  8. Aging processes in precipitation-hardening composite materials based on a D16 aluminum alloy

    NASA Astrophysics Data System (ADS)

    Chernyshova, T. A.; Kobeleva, L. I.

    2010-09-01

    Aging of composite materials (CMs) based on an aluminum D16 alloy and reinforced by Al3Ti intermetallic inclusions (0-10 vol %) having formed upon an in situ reaction and by SiC particles (0-30 vol %) ≤3 or 28 μm in size is studied. Oxide ceramic nanoparticles (0.1 wt %) are used to modify the structure of the CMs. The structures of the CMs before and after aging are analyzed by optical microscopy and scanning electron microscopy on a microscope equipped with an X-ray energy dispersive spectrometer. The hardness of the CMs is measured. The overall hardening of aged CMs is shown to result from a competition between the hardening effects induced by the formation of Guinier-Preston zones and the precipitation of the high-temperature θ and S phases. These effects are controlled by the dislocation density in the matrix.

  9. Optimisation of the Fischer-Tropsch process using zeolites for tail gas separation.

    PubMed

    Perez-Carbajo, J; Gómez-Álvarez, P; Bueno-Perez, R; Merkling, P J; Calero, S

    2014-03-28

    This work is aimed at optimizing a Fischer-Tropsch Gas To Liquid (GTL) process by recycling compounds of the expelled gas mixture using zeolites for the separation. To that end, we have performed a computational study on four structures widely used in industry. A range of Si/Al ratios have been explored and the effects of their distribution assessed. The ability of the considered force fields and molecular models to reproduce experimental results has been widely proved in previously reported studies. Since this tail gas is formed by a five-component mixture, namely carbon dioxide, methane, carbon monoxide, nitrogen and hydrogen, molecular simulations present clear advantages over experiments. In addition, the viability of the Ideal Adsorption Solution Theory (IAST) has been evaluated to easily handle further separation steps. On the basis of the obtained results, we provide a separation scheme to perform sequentially the separation of CO2, CH4, CO, N2 and H2.

  10. Apparatus and process for the separation of gases using supersonic expansion and oblique wave compression

    DOEpatents

    VanOsdol, John G.

    2014-07-08

    The disclosure provides an apparatus and method for gas separation through the supersonic expansion and subsequent deceleration of a gaseous stream. The gaseous constituent changes phase from the gaseous state by desublimation or condensation during the acceleration producing a collectible constituent, and an oblique shock diffuser decelerates the gaseous stream to a subsonic velocity while maintain the collectible constituent in the non-gaseous state. Following deceleration, the carrier gas and the collectible constituent at the subsonic velocity are separated by a separation means, such as a centrifugal, electrostatic, or impingement separator. In an embodiment, the gaseous stream issues from a combustion process and is comprised of N.sub.2 and CO.sub.2.

  11. Extensive separations (CLEAN) processing strategy compared to TRUEX strategy and sludge wash ion exchange

    SciTech Connect

    Knutson, B.J.; Jansen, G.; Zimmerman, B.D.; Seeman, S.E.; Lauerhass, L.; Hoza, M.

    1994-08-01

    Numerous pretreatment flowsheets have been proposed for processing the radioactive wastes in Hanford`s 177 underground storage tanks. The CLEAN Option is examined along with two other flowsheet alternatives to quantify the trade-off of greater capital equipment and operating costs for aggressive separations with the reduced waste disposal costs and decreased environmental/health risks. The effect on the volume of HLW glass product and radiotoxicity of the LLW glass or grout product is predicted with current assumptions about waste characteristics and separations processes using a mass balance model. The prediction is made on three principal processing options: washing of tank wastes with removal of cesium and technetium from the supernatant, with washed solids routed directly to the glass (referred to as the Sludge Wash C processing strategy); the previous steps plus dissolution of the solids and removal of transuranic (TRU) elements, uranium, and strontium using solvent extraction processes (referred to as the Transuranic Extraction Option C (TRUEX-C) processing strategy); and an aggressive yet feasible processing strategy for separating the waste components to meet several main goals or objectives (referred to as the CLEAN Option processing strategy), such as the LLW is required to meet the US Nuclear Regulatory Commission Class A limits; concentrations of technetium, iodine, and uranium are reduced as low as reasonably achievable; and HLW will be contained within 1,000 borosilicate glass canisters that meet current Hanford Waste Vitrification Plant glass specifications.

  12. Use of Separator with Regular Granular Filling in Extraction Processes - 12209

    SciTech Connect

    Volk, Vladimir; Veselov, Sergey; Zherebtsov, Alexander

    2012-07-01

    The separator with a regular granular filling has been developed to be used for the operations of the removal of carbon-black impurities from the aqueous flow; the intra-cycle regeneration of back-extractants; and the concentrating back-extraction of plutonium in the extraction SNF reprocessing technology. The process conditions for those operations have been experimentally tested using this separator. Thus, the separator for operations of concentrating reextraction of plutonium and regeneration recycling extractant allows to: - derive plutonium from the organic stream into an extremely concentrated form, reducing the amount of liquid radioactive waste (raffinate, decantate) plutonium branches to a minimum; - controlling the processes of concentration of uranium and plutonium, get uranium-plutonium product with required concentration and the amount of metal with required ratio; - eliminate contamination of the emulsion flows; - simplify the purification of uranium from the extract plutonium; - test results showed that when working on a solution 'hydrazine-DTPA' in the separator it is achieved the extraction of plutonium re-extract - 82% TC - at 56-65%. With the transition to the reextraction by solution 'U (IV)-hydrazine', of plutonium into re-extract increases to 95%, technetium - up to 83%; - regenerate the extractant recycling minimizing the amount of liquid radioactive waste generated as a technology used as well as alternative 'salt-free' systems; - it is found that the regeneration of the extractant solution of soda and EDA in the separator at a load of 3.2 m{sup 3} / (m{sup 2}.h) it can be achieved almost complete phase separation. Residual carryover of 0,005-0,006% emulsion is on the verge of analytical detection. - It is shown that in the depth of separation phase a separation of the extractant regeneration of quality superior is more than 5-7 times to the extraction. (authors)

  13. Apparatus and process for the refrigeration, liquefaction and separation of gases with varying levels of purity

    DOEpatents

    Bingham, Dennis N.; Wilding, Bruce M.; McKellar, Michael G.

    2002-01-01

    A process for the separation and liquefaction of component gasses from a pressurized mix gas stream is disclosed. The process involves cooling the pressurized mixed gas stream in a heat exchanger so as to condensing one or more of the gas components having the highest condensation point; separating the condensed components from the remaining mixed gas stream in a gas-liquid separator; cooling the separated condensed component stream by passing it through an expander; and passing the cooled component stream back through the heat exchanger such that the cooled component stream functions as the refrigerant for the heat exchanger. The cycle is then repeated for the remaining mixed gas stream so as to draw off the next component gas and further cool the remaining mixed gas stream. The process continues until all of the component gases are separated from the desired gas stream. The final gas stream is then passed through a final heat exchanger and expander. The expander decreases the pressure on the gas stream, thereby cooling the stream and causing a portion of the gas stream to liquify within a tank. The portion of the gas which is hot liquefied is passed back through each of the heat exchanges where it functions as a refrigerant.

  14. Apparatus and process for the refrigeration, liquefaction and separation of gases with varying levels of purity

    DOEpatents

    Bingham, Dennis N.; Wilding, Bruce M.; McKellar, Michael G.

    2000-01-01

    A process for the separation and liquefaction of component gasses from a pressurized mix gas stream is disclosed. The process involves cooling the pressurized mixed gas stream in a heat exchanger so as to condense one or more of the gas components having the highest condensation point; separating the condensed components from the remaining mixed gas stream in a gas-liquid separator; cooling the separated condensed component stream by passing it through an expander; and passing the cooled component stream back through the heat exchanger such that the cooled component stream functions as the refrigerant for the heat exchanger. The cycle is then repeated for the remaining mixed gas stream so as to draw off the next component gas and further cool the remaining mixed gas stream. The process continues until all of the component gases are separated from the desired gas stream. The final gas stream is then passed through a final heat exchanger and expander. The expander decreases the pressure on the gas stream, thereby cooling the stream and causing a portion of the gas stream to liquify within a tank. The portion of the gas which is not liquefied is passed back through each of the heat exchanges where it functions as a refrigerant.

  15. Method for separating water soluble organics from a process stream by aqueous biphasic extraction

    DOEpatents

    Chaiko, David J.; Mego, William A.

    1999-01-01

    A method for separating water-miscible organic species from a process stream by aqueous biphasic extraction is provided. An aqueous biphase system is generated by contacting a process stream comprised of water, salt, and organic species with an aqueous polymer solution. The organic species transfer from the salt-rich phase to the polymer-rich phase, and the phases are separated. Next, the polymer is recovered from the loaded polymer phase by selectively extracting the polymer into an organic phase at an elevated temperature, while the organic species remain in a substantially salt-free aqueous solution. Alternatively, the polymer is recovered from the loaded polymer by a temperature induced phase separation (cloud point extraction), whereby the polymer and the organic species separate into two distinct solutions. The method for separating water-miscible organic species is applicable to the treatment of industrial wastewater streams, including the extraction and recovery of complexed metal ions from salt solutions, organic contaminants from mineral processing streams, and colorants from spent dye baths.

  16. Semi-industrial experimental study on bauxite separation using a cell-column integration process

    NASA Astrophysics Data System (ADS)

    Zhang, Ning-ning; Zhou, Chang-chun; Cong, Long-fei; Cao, Wen-long; Zhou, You

    2016-01-01

    The cyclonic-static micro-bubble flotation column (FCSMC) is a highly efficient mineral processing equipment. In this study, a cell-column (FCSMC) integration process was investigated for the separation of bauxite and its feasibility was analyzed on a theoretical basis. The properties of low-grade bauxite ore from Henan Province, China were analyzed. Parameters such as reagent dosage, scraping bubble time, and pressure of the circulating pump during the sorting process were investigated and optimized to improve the flotation efficiency. On the basis of these parameters, continuous separation experiments were conducted. Bauxite concentrate with an aluminum-to-silicon (A/S) mass ratio of 6.37 and a 77.63wt% recovery rate were achieved via a flow sheet consisting of "fast flotation using a flotation cell, one roughing flotation and one cleaning flotation using flotation columns". Compared with the full-flotation-cells process, the cell-column integration process resulted in an increase of the A/S ratio by 0.41 and the recovery rate by 17.58wt%. Cell-column integration separation technology represents a new approach for the separation of middle-to-low-grade bauxite ore.

  17. Microfluidic chemical processing with on-chip washing by deterministic lateral displacement arrays with separator walls

    PubMed Central

    Chen, Yu; D'Silva, Joseph; Austin, Robert H.; Sturm, James C.

    2015-01-01

    We describe a microfluidic device for on-chip chemical processing, such as staining, and subsequent washing of cells. The paper introduces “separator walls” to increase the on-chip incubation time and to improve the quality of washing. Cells of interest are concentrated into a treatment stream of chemical reagents at the first separator wall for extended on-chip incubation without causing excess contamination at the output due to diffusion of the unreacted treatment chemicals, and then are directed to the washing stream before final collections. The second separator wall further reduces the output contamination from diffusion to the washing stream. With this approach, we demonstrate on-chip leukocyte staining with Rhodamine 6G and washing. The results suggest that other conventional biological and analytical processes could be replaced by the proposed device. PMID:26396659

  18. Advancing adsorption and membrane separation processes for the gigaton carbon capture challenge.

    PubMed

    Wilcox, Jennifer; Haghpanah, Reza; Rupp, Erik C; He, Jiajun; Lee, Kyoungjin

    2014-01-01

    Reducing CO2 in the atmosphere and preventing its release from point-source emitters, such as coal and natural gas-fired power plants, is a global challenge measured in gigatons. Capturing CO2 at this scale will require a portfolio of gas-separation technologies to be applied over a range of applications in which the gas mixtures and operating conditions will vary. Chemical scrubbing using absorption is the current state-of-the-art technology. Considerably less attention has been given to other gas-separation technologies, including adsorption and membranes. It will take a range of creative solutions to reduce CO2 at scale, thereby slowing global warming and minimizing its potential negative environmental impacts. This review focuses on the current challenges of adsorption and membrane-separation processes. Technological advancement of these processes will lead to reduced cost, which will enable subsequent adoption for practical scaled-up application. PMID:24702296

  19. Advancing adsorption and membrane separation processes for the gigaton carbon capture challenge.

    PubMed

    Wilcox, Jennifer; Haghpanah, Reza; Rupp, Erik C; He, Jiajun; Lee, Kyoungjin

    2014-01-01

    Reducing CO2 in the atmosphere and preventing its release from point-source emitters, such as coal and natural gas-fired power plants, is a global challenge measured in gigatons. Capturing CO2 at this scale will require a portfolio of gas-separation technologies to be applied over a range of applications in which the gas mixtures and operating conditions will vary. Chemical scrubbing using absorption is the current state-of-the-art technology. Considerably less attention has been given to other gas-separation technologies, including adsorption and membranes. It will take a range of creative solutions to reduce CO2 at scale, thereby slowing global warming and minimizing its potential negative environmental impacts. This review focuses on the current challenges of adsorption and membrane-separation processes. Technological advancement of these processes will lead to reduced cost, which will enable subsequent adoption for practical scaled-up application.

  20. Modeling of Convective-Stratiform Precipitation Processes: Sensitivity to Partitioning Methods and Numerical Advection Schemes

    NASA Technical Reports Server (NTRS)

    Lang, Steve; Tao, W.-K.; Simpson, J.; Ferrier, B.; Einaudi, Franco (Technical Monitor)

    2001-01-01

    Six different convective-stratiform separation techniques, including a new technique that utilizes the ratio of vertical and terminal velocities, are compared and evaluated using two-dimensional numerical simulations of a tropical [Tropical Ocean Global Atmosphere Coupled Ocean-Atmosphere Response Experiment (TOGA COARE)] and midlatitude continental [Preliminary Regional Experiment for STORM-Central (PRESTORM)] squall line. The simulations are made using two different numerical advection schemes: 4th order and positive definite advection. Comparisons are made in terms of rainfall, cloud coverage, mass fluxes, apparent heating and moistening, mean hydrometeor profiles, CFADs (Contoured Frequency with Altitude Diagrams), microphysics, and latent heating retrieval. Overall, it was found that the different separation techniques produced results that qualitatively agreed. However, the quantitative differences were significant. Observational comparisons were unable to conclusively evaluate the performance of the techniques. Latent heating retrieval was shown to be sensitive to the use of separation technique mainly due to the stratiform region for methods that found very little stratiform rain. The midlatitude PRESTORM simulation was found to be nearly invariant with respect to advection type for most quantities while for TOGA COARE fourth order advection produced numerous shallow convective cores and positive definite advection fewer cells that were both broader and deeper penetrating above the freezing level.

  1. Comment on 'Modeling of Convective-Stratiform Precipitation Processes: Sensitivity to Partitioning Methods' by Matthias Steiner

    NASA Technical Reports Server (NTRS)

    Lang, Steve; Tao, W.-K.; Simpson, J.; Ferrier, B.

    2003-01-01

    Despite the obvious notion that the presence of hail or graupel is a good indication of convection, the model results show this does not provide an objective benchmark partly due to the unrealistic presence of small amounts of hail or graupel throughout the anvil in the model but mainly because of the significant amounts of hail or graupel, especially in the tropical TOGA COARE simulation, in the transition zone. Without use of a "transition" category, it is open to debate as how this region should best be defined, as stratiform or as convective. So, the presence of significant hail or graupel contents in this zone significantly degrades its use an objective benchmark for convection. The separation algorithm comparison was done in the context of a cloud-resolving model. These models are widely used and serve a variety of purposes especially with regard to retrieving information that cannot be directly measured by providing synthetic data sets that are consistent and complete. Separation algorithms are regularly applied in these models. However, as with any modeling system, these types 'of models are constantly being improved to overcome any known deficiencies and make them more accurate representations of observed systems. The presence of hail and graupel in the anvil and the bias towards heavy rainfall rates are two such examples of areas that need improvement. Since, both of these can effect the perceived performance of the separation algorithms, the Lang et al. (2003) study did not want to overstate the relative performance of any specific algorithms.

  2. Precipitation-runoff processes in the Feather River basin, northeastern California, and streamflow predictability, water years 1971-97

    USGS Publications Warehouse

    Koczot, Kathryn M.; Jeton, Anne E.; McGurk, Bruce; Dettinger, Michael D.

    2005-01-01

    Precipitation-runoff processes in the Feather River Basin of northern California determine short- and long-term streamflow variations that are of considerable local, State, and Federal concern. The river is an important source of water and power for the region. The basin forms the headwaters of the California State Water Project. Lake Oroville, at the outlet of the basin, plays an important role in flood management, water quality, and the health of fisheries as far downstream as the Sacramento-San Joaquin Delta. Existing models of the river simulate streamflow in hourly, daily, weekly, and seasonal time steps, but cannot adequately describe responses to climate and land-use variations in the basin. New spatially detailed precipitation-runoff models of the basin have been developed to simulate responses to climate and land-use variations at a higher spatial resolution than was available previously. This report characterizes daily rainfall, snowpack evolution, runoff, water and energy balances, and streamflow variations from, and within, the basin above Lake Oroville. The new model's ability to predict streamflow is assessed. The Feather River Basin sits astride geologic, topographic, and climatic divides that establish a hydrologic character that is relatively unusual among the basins of the Sierra Nevada. It straddles a north-south geologic transition in the Sierra Nevada between the granitic bedrock that underlies and forms most of the central and southern Sierra Nevada and volcanic bedrock that underlies the northernmost parts of the range (and basin). Because volcanic bedrock generally is more permeable than granitic, the northern, volcanic parts of the basin contribute larger fractions of ground-water flow to streams than do the southern, granitic parts of the basin. The Sierra Nevada topographic divide forms a high altitude ridgeline running northwest to southeast through the middle of the basin. The topography east of this ridgeline is more like the rain

  3. PURIFICATION OF PLUTONIUM USING A CERIUM PRECIPITATE AS A CARRIER FOR FISSION PRODUCTS

    DOEpatents

    Faris, B.F.; Olson, C.M.

    1961-07-01

    Bismuth phosphate carrier precipitation processes are described for the separation of plutonium from fission products wherein in at least one step bismuth phosphate is precipitated in the presence of hexavalent plutonium thereby carrying a portion of the fission products from soluble plu tonium values. In this step, a cerium phosphate precipitate is formed in conjunction with the bismuth phosphate precipitate, thereby increasing the amount of fission products removed from solution.

  4. Numerical Simulation of Tuff Dissolution and Precipitation Experiments: Validation of Thermal-Hydrologic-Chemical (THC) Coupled-Process Modeling

    NASA Astrophysics Data System (ADS)

    Dobson, P. F.; Kneafsey, T. J.

    2001-12-01

    to evaluate larger-scale silica sealing observed in a portion of the Yellowstone geothermal system, a natural analog for the precipitation-experiment processes.

  5. Precipitation of jarosite-type double salts from spent acid solutions from a chemical coal cleaning process

    SciTech Connect

    Norton, G.

    1990-09-21

    The precipitation of jarosite compounds to remove Na, K, Fe, and SO{sub 4}{sup 2{minus}} impurities from spent acid solutions from a chemical coal cleaning process was studied. Simple heating of model solutions containing Fe{sub 2}(SO{sub 4}){sub 3}, Na{sub 2}SO{sub 4}, and K{sub 2}SO{sub 4} caused jarosite (KFe{sub 3}(SO{sub 4}){sub 2}(OH){sub 6}) to form preferentially to natrojarosite (NaFe{sub 3}(SO{sub 4}){sub 2}(OH){sub 6}). Virtually all of the K, about 90% of the Fe, and about 30% of the SO{sub 4}{sup 2{minus}} could be precipitated from those solutions at 95{degree}C, while little or no Na was removed. However, simple heating of model solutions containing only Fe{sub 2}(SO{sub 4}){sub 3} and Na{sub 2}SO{sub 4} up to 95{degree}C for {le}12 hours produced low yields of jarosite compounds, and the Fe concentration in the solution had to be increased to avoid the formation of undesirable Fe compounds. Precipitate yields could be increased dramatically in model solutions of Na{sub 2}SO{sub 4}/Fe{sub 2}(SO{sub 4}){sub 3} containing excess Fe by using either CaCO{sub 3}, Ca(OH){sub 2}, or ZnO to neutralize H{sub 2}SO{sub 4} released during hydrolysis of the Fe{sub 2}(SO{sub 4}){sub 3} and during the precipitation reactions. Results obtained from the studies with model solutions were applied to spent acids produced during laboratory countercurrent washing of coal which had been leached with a molten NaOH/KOH mixture. Results indicated that jarosite compounds can be precipitated effectively from spent acid solutions by heating for 6 hours at 80{degree}C while maintaining a pH of about 1.5 using CaCO{sub 3}.

  6. Processing, structure and magnetic properties correlation in co-precipitated Ca-ferrite

    NASA Astrophysics Data System (ADS)

    Abasht, Behzad; Beitollahi, Ali; Mirkazemi, Seyyed Mohammad

    2016-12-01

    La-substituted hexagonal calcium ferrite, Ca1-XLaXFe12O19 (x varies from 0 to 0.6 with the step of 0.2), was synthesized by applying co-precipitation method, in which the molar ratio of Fe3+/(Ca2++La2+) was 11. The ferrite precursors were prepared from aqueous solution of calcium nitrate, ferric nitrate and lanthanum nitrate by co-precipitation of calcium, iron and lanthanum ions by using an aqueous base of sodium hydroxide (1.5 M) at the pH of 14 and at room temperature. These precursors were calcinated with different amount of La at different temperature of 700, 1100 and 1200 °C for constant calcination time of 1 h in a static air atmosphere. Some tests such as simultaneous thermal analysis (STA), X-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM) were carried out to investigate the thermal behavior, crystallographic properties, morphology and magnetic properties of the precursor powders which were calcinated at different temperatures. The powder XRD patterns of samples which consisted of La as dopant and were calcinated at 1200 °C for 1 h, indicates the formation of calcium hexaferrite and also α-Fe2O3 besides Magnetoplumbite-phase (M-phase). However, the results showed that CaFe4O7 and α-Fe2O3 phases were formed in the sample with the same condition but without using any dopant. The results of SEM showed that the calcium hexaferrite particle were regular hexagonal platelets with the size range of 1-2 μm. The magnetic properties such as maximum magnetization (MMax), remanent magnetization (Mr) and coercivity (Hc) were measured from the hysteresis loops. Low values of coercive field (16.3 kA m-1) and maximum magnetization (50.6 A m2 kg-1) were obtained from calcium hexaferrite particle in optimum amount of La (X=0.4) which calcinated at the temperature of 1200 °C.

  7. DMS cyclone separation processes for optimization of plastic wastes recycling and their implications.

    PubMed

    Gent, Malcolm Richard; Menendez, Mario; Toraño, Javier; Torno, Susana

    2011-06-01

    It is demonstrated that substantial reductions in plastics presently disposed of in landfills can be achieved by cyclone density media separation (DMS). In comparison with the size fraction of plastics presently processed by industrial density separations (generally 6.4 to 9.5 mm), cyclone DMS methods are demonstrated to effectively process a substantially greater range of particle sizes (from 0.5 up to 120 mm). The purities of plastic products and recoveries obtained with a single stage separation using a cylindrical cyclone are shown to attain virtually 100% purity and recoveries >99% for high-density fractions and >98% purity and recoveries were obtained for low-density products. Four alternative schemas of multi-stage separations are presented and analyzed as proposed methods to obtain total low- and high-density plastics fraction recoveries while maintaining near 100% purities. The results of preliminary tests of two of these show that the potential for processing product purities and recoveries >99.98% of both density fractions are indicated. A preliminary economic comparison of capital costs of DMS systems suggests cyclone DMS methods to be comparable with other DMS processes even if the high volume capacity for recycling operations of these is not optimized.

  8. SEPARATION OF URANYL AND RUTHENIUM VALUES BY THE TRIBUTYL PHOSPHATE EXTRACTION PROCESS

    DOEpatents

    Wilson, A.S.

    1961-05-01

    A process is given for separating uranyl values from ruthenium values contained in an aqueous 3 to 4 M nitric acid solution. After the addition of hydrogen peroxide to obtain a concentration of 0.3 M, the uranium is selectively extracted with kerosene-diluted tributyl phosphate.

  9. Compound Cue Processing within the Fast and Frugal Heuristics Approach in Nonlinearly Separable Environments

    ERIC Educational Resources Information Center

    Garcia-Retamero, Rocio; Hoffrage, Ulrich; Dieckmann, Anja; Ramos, Manuel

    2007-01-01

    Three experiments investigated whether participants used Take The Best (TTB) Configural, a fast and frugal heuristic that processes configurations of cues when making inferences concerning which of two alternatives has a higher criterion value. Participants were presented with a compound cue that was nonlinearly separable from its elements. The…

  10. Principles of Stagewise Separation Process Calculations: A Simple Algebraic Approach Using Solvent Extraction.

    ERIC Educational Resources Information Center

    Crittenden, Barry D.

    1991-01-01

    A simple liquid-liquid equilibrium (LLE) system involving a constant partition coefficient based on solute ratios is used to develop an algebraic understanding of multistage contacting in a first-year separation processes course. This algebraic approach to the LLE system is shown to be operable for the introduction of graphical techniques…

  11. Improvement for the multi-scale periodic characteristics revealing of precipitation signals and its impact assessment on soil hydrological process by combining HHT and CWT approaches

    NASA Astrophysics Data System (ADS)

    Yu, S.; Yang, J.; Liu, G.; Yao, R.; Wang, X.

    2015-03-01

    This study conducts a detailed analysis of multi-scale periodic features involved in the annual and seasonal precipitation signals at the typical coastal reclamation region in China by selecting the suitable continuous wavelet transform (CWT) and innovatively combining the improved Hilbert-Huang transform (HHT), and further deduces the precipitation trend and its impacts on the future soil hydrological process. The Morlet wavelet transform is proved suitable in revealing the precipitation signals broad-scale periodicities, however, the critical mode mixing problem in CWT causes the poor significance in the fine-scale periodicities, which cannot well match the climate background. By combining the HHT approach, the fine-scale mode mixing drawback in CWT is effectively eliminated, and the the studied precipitation signals multi-scale periodicities are accurately revealed. Consequently, an overall decreasing trend of annual and seasonal precipitation in future years is demonstrated. Furthermore, by novelly using the cross wavelet transform (XWT) and wavelet transform coherence (WTC) approaches, the prominent correlations between the precipitation dynamics and soil and groundwater salinities dynamics, it is demonstrated that the precipitation increase can effectively leach the surface soil salt downwards into the deeper soil layers and groundwater with 5-7-day lag in the new cultivated tidal land. The revealed future decreasing trend of precipitation, especially in spring and summer, may aggravate the soil salinization at the coastal reclamation region, thus some reasonable salt leaching and evaporation suppression measures need to be taken to prevent the possible soil secondary salinization process.

  12. New, Improved Bulk-microphysical Schemes for Studying Precipitation Processes in WRF. Part 1; Comparisons with Other Schemes

    NASA Technical Reports Server (NTRS)

    Tao, W.-K.; Shi, J.; Chen, S. S> ; Lang, S.; Hong, S.-Y.; Thompson, G.; Peters-Lidard, C.; Hou, A.; Braun, S.; Simpson, J.

    2007-01-01

    Advances in computing power allow atmospheric prediction models to be mn at progressively finer scales of resolution, using increasingly more sophisticated physical parameterizations and numerical methods. The representation of cloud microphysical processes is a key component of these models, over the past decade both research and operational numerical weather prediction models have started using more complex microphysical schemes that were originally developed for high-resolution cloud-resolving models (CRMs). A recent report to the United States Weather Research Program (USWRP) Science Steering Committee specifically calls for the replacement of implicit cumulus parameterization schemes with explicit bulk schemes in numerical weather prediction (NWP) as part of a community effort to improve quantitative precipitation forecasts (QPF). An improved Goddard bulk microphysical parameterization is implemented into a state-of the-art of next generation of Weather Research and Forecasting (WRF) model. High-resolution model simulations are conducted to examine the impact of microphysical schemes on two different weather events (a midlatitude linear convective system and an Atllan"ic hurricane). The results suggest that microphysics has a major impact on the organization and precipitation processes associated with a summer midlatitude convective line system. The 31CE scheme with a cloud ice-snow-hail configuration led to a better agreement with observation in terms of simulated narrow convective line and rainfall intensity. This is because the 3ICE-hail scheme includes dense ice precipitating (hail) particle with very fast fall speed (over 10 m/s). For an Atlantic hurricane case, varying the microphysical schemes had no significant impact on the track forecast but did affect the intensity (important for air-sea interaction)

  13. The use of safeguards data for process monitoring in the Advanced Test Line for Actinide Separations

    SciTech Connect

    Barnes, J.W.; Yarbro, S.L.

    1987-01-01

    Los Alamos is constructing an integrated process monitoring/materials control and accounting (PM/MC and A) system in the Advanced Testing Line for Actinide Separations (ATLAS) at the Los Alamos Plutonium Facility. The ATLAS will test and demonstrate new methods for aqueous processing of plutonium. The ATLAS will also develop, test, and demonstrate the concepts for integrated process monitoring/materials control and accounting. We describe how this integrated PM/MC and A system will function and provide benefits to both process research and materials accounting personnel.

  14. Energy minimization of separation processes using conventional/membrane hybrid systems

    SciTech Connect

    Gottschlich, D.E.; Roberts, D.L. )

    1990-09-28

    The purpose of this study was to identify the general principles governing the choice of hybrid separation systems over straight membrane or straight nonmembrane systems and to do so by examining practical applications (process design and economics). Our focus was to examine the energy consumption characteristics and overall cost factors of the membrane and nonmembrane technologies that cause hybrid systems to be preferred over nonhybrid systems. We evaluated four cases studies, chosen on the basis of likelihood of commercial viability of a hybrid system and magnitude of energy savings: (1) propane/propylene separation; (2) removal of nitrogen from natural gas; (3) concentration of Kraft black liquor; and (4)solvent deasphalting. For propane/propylene splitting, the membrane proved to be superior to distillation in both thermodynamic efficiency and processing cost (PC) when the product was 95% pure propylene. However, to produce higher purity products, the membrane alone could not perform the separation, and a membrane/distillation hybrid was required. In these cases, there is an optimum amount of separation to be accomplished by the membrane (expressed as the fraction of the total availability change of the membrane/distillation hybrid that takes place in the membrane and defined as {phi}{sub m}, the thermodynamic extent of separation). Qualitative and quantitative guidelines are discussed with regard to choosing a hybrid system. 54 refs., 66 figs., 36 tabs.

  15. Usage of multivariate geostatistics in interpolation processes for meteorological precipitation maps

    NASA Astrophysics Data System (ADS)

    Gundogdu, Ismail Bulent

    2015-09-01

    Long-term meteorological data are very important both for the evaluation of meteorological events and for the analysis of their effects on the environment. Prediction maps which are constructed by different interpolation techniques often provide explanatory information. Conventional techniques, such as surface spline fitting, global and local polynomial models, and inverse distance weighting may not be adequate. Multivariate geostatistical methods can be more significant, especially when studying secondary variables, because secondary variables might directly affect the precision of prediction. In this study, the mean annual and mean monthly precipitations from 1984 to 2014 for 268 meteorological stations in Turkey have been used to construct country-wide maps. Besides linear regression, the inverse square distance and ordinary co-Kriging (OCK) have been used and compared to each other. Also elevation, slope, and aspect data for each station have been taken into account as secondary variables, whose use has reduced errors by up to a factor of three. OCK gave the smallest errors (1.002 cm) when aspect was included.

  16. Precipitation Processes Derived from TRMM Satellite Data, Cloud Resolving Model and Field Campaigns

    NASA Technical Reports Server (NTRS)

    Tao, W.-K.; Lang, S.; Simpson, J.; Meneghini, R.; Halverson, J.; Johnson, R.; Adler, R.; Einaudi, Franco (Technical Monitor)

    2001-01-01

    Rainfall is a key link in the hydrologic cycle and is a primary heat source for the atmosphere. The vertical distribution of latent-heat release, which is accompanied by rainfall, modulates the large-scale circulations of the tropics and in turn can impact midlatitude weather. This latent heat release is a consequence of phase changes between vapor, liquid. and solid water. Present large-scale weather and climate models can simulate cloud latent heat release only crudely thus reducing their confidence in predictions on both global and regional scales. In this paper, NASA Tropical Rainfall Measuring (TRMM) precipitation radar (PR) derived rainfall information and the Goddard Convective and Stratiform Heating (CSH) algorithm used to estimate the four-dimensional structure of global monthly latent heating and rainfall profiles over the global tropics from December 1997 to October 2000. Rainfall latent heating and radar reflectively structure between ENSO (1997-1998 winter) and non-ENSO (1998-1999 winter) periods are examined and compared. The seasonal variation of heating over various geographic locations (i.e. Indian ocean vs west Pacific; Africa vs S. America) are also analyzed. In addition, the relationship between rainfall latent heating maximum heating level), radar reflectively and SST are examined.

  17. Effect of temperature and active biogas process on passive separation of digested manure.

    PubMed

    Kaparaju, P; Angelidaki, I

    2008-03-01

    The objective of the study was to identify the optimum time interval for effluent removal after temporarily stopping stirring in otherwise continuously stirred tank reactors. Influence of temperature (10 and 55 degrees C) and active biogas process on passive separation of digested manure, where no outside mechanical or chemical action was used, within the reactor was studied in three vertical settling columns (100 cm deep). Variations in solids and microbial distribution at top, middle and bottom layers of column were assessed over a 15 day settling period. Results showed that best solids separation was achieved when digested manure was allowed to settle at 55 degrees C with active biogas process (pre-incubated at 55 degrees C) compared to separation at 55 degrees C without active biogas process (autoclaved at 120 degrees C, for 20 min) or at 10 degrees C with active biogas process. Maximum solids separation was noticed 24h after settling in column incubated at 55 degrees C, with active biogas process. Microbiological analyses revealed that proportion of Archaea and Bacteria, absent in the autoclaved material, varied with incubation temperature, time and sampling depth. Short rod shaped bacteria dominated at 55 degrees C, while long rod shaped bacteria dominated at 10 degrees C. Methanosarcinaceae were seen more abundant in the surface layer at 55 degrees C while it was seen more common in the top and bottom layers at 10 degrees C. Thus, passive separation of digester contents within the reactor can be used effectively as an operating strategy to optimize biogas production by increasing the solids and biomass retention times. A minimum of 1-2h "non-stirring" period appears to be optimal time before effluent removal in plants where extraction is batch-wise 2-4 times a day.

  18. Separation and Purification of Mineral Salts from Spacecraft Wastewater Processing via Electrostatic Beneficiation

    NASA Technical Reports Server (NTRS)

    Miles, John D., II; Lunn, Griffin

    2013-01-01

    Electrostatic separation is a class of material processing technologies commonly used for the sorting of coarse mixtures by means of electrical forces acting on charged or polarized particles. Most if not all of the existing tribo-electrostatic separators had been initially developed for mineral ores beneficiation. It is a well-known process that has been successfully used to separate coal from minerals. Potash (potassium) enrichment where underground salt mines containing large amounts of sodium is another use of this techno logy. Through modification this technology can be used for spacecraft wastewater brine beneficiation. This will add in closing the gap beeen traveling around Earth's Gravity well and long-term space explorations. Food has been brought on all man missions, which is why plant growth for food crops continues to be of interest to NASA. For long-term mission considerations food productions is one of the top priorities. Nutrient recovery is essential for surviving in or past low earth orbit. In our advance bio-regenerative process instead of nitrogen gas produced; soluble nitrate salts that can be recovered for plant fertilizer would be produced instead. The only part missing is the beneficiation of brine to separate the potassium from the sodium. The use of electrostatic beneficiation in this experiment utilizes the electrical charge differences between aluminum and dried brine by surface contact. The helixes within the aluminum tribocharger allows for more surface contact when being agitated. When two materials are in contact, the material with the highest affinity for electrons becomes negatively charged, while the other becomes positively charged. This contact exchange of charge may cause the particles to agglomerate depending on their residence time within the tribocharger, compromising the efficiency of separation. The aim of this experiment is to further the development in electrostatic beneficiation by optimizing the separation of ersatz and

  19. Process for liquefying carbonaceous materials of high molecular weight and for separating liquefaction products

    DOEpatents

    Malek, John M.

    1977-01-01

    Process characterized by comprising successively a dissolution zone fed with carbonaceous solids and with a solvent, a high pressure hydrogenation zone provided with a source of hydrogen, and a hydrogenation products separation zone, wherein the improvement consists mainly in chemical upgrading of the liquidform products derived from the separation zone, and recycling a part of the upgraded products to the dissolution zone, this recycled part being of either positively acidic or positively basic properties for enhancing the dissolution - decomposition of base-acid structures present in the carbonaceous solid feed.

  20. 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.

  1. Development of a process for treating red water by organic/inorganic separation and biodegradation

    SciTech Connect

    Chaiko, D.J.; Reichley-Yinger, L.; Orth, E.R.; Van Deventer, E.H.; Vandegrift, G.F.; Krumpole, M.; Helt, J.E.; Coleman, R.D.; Kakar, S.N.; Tsai, T.S.; Horken, K.; Killian, W.; Sather, N.F.

    1989-01-01

    The final stage of TNT production involves the purification of TNT by selective conversion of the unsymmetrical isomers into water-soluble sulfonates by reaction of the crude TNT with an aqueous sulfite (sellite) solution. This treatment generates an intense, red-colored waste stream commonly referred to as red water,'' which has been listed as a hazardous waste by the EPA. Its composition is primarily soluble organic sulfonates and the sodium salts of sulfate, sulfite, nitrate and nitrite. Argonne National Laboratory (ANL) is developing a process for treating red water. This process couples the separation of the organic and inorganic constituents of red water, followed by treatment of the organics by biodegradation to nonhazardous products. Sludge formation in the biotreatment step is further minimized by conversion of the sodium-containing organics to their respective acidic forms during the organic/inorganic separation. The level of separation will be such that the inorganic residues can qualify as nonhazardous byproducts. Initial efforts have been directed towards performing proof-of-concept demonstrations of processes that can achieve these goals. Candidate technologies that are being examined for separating the organic constituents from actual red water samples are (1) flocculation, (2) foam fractionation, and (3) aqueous biphasic solvent extraction. 22 refs.

  2. Shared and separate systems in bilingual language processing: converging evidence from eyetracking and brain imaging.

    PubMed

    Marian, Viorica; Spivey, Michael; Hirsch, Joy

    2003-07-01

    The neurological and cognitive aspects of bilingual language processing were examined in late Russian-English bilinguals using headband-mounted eyetracking and functional neuroimaging. A series of three eyetracking studies suggested that, at early stages of word recognition, bilinguals can activate both languages in parallel, even when direct linguistic input is in one language only. A functional neuroimaging study suggested that, although the same general structures are active for both languages, differences within these general structures are present across languages and across levels of processing. For example, different centers of activation were associated with first versus second language processing within the left Inferior Frontal Gyrus, but not within the Superior Temporal Gyrus. We suggest that parallel activation (as found with eyetracking) and shared cortical structures (as found with fMRI) may be characteristic of early stages of language processing (such as phonetic processing), but the two languages may be using separate structures at later stages of processing (such as lexical processing).

  3. Optimization of an improved single-column chromatographic process for the separation of enantiomers.

    PubMed

    Kazi, Monzure-Khoda; Medi, Bijan; Amanullah, Mohammad

    2012-03-30

    This work addresses optimization of an improved single-column chromatographic (ISCC) process for the separation of guaifenesin enantiomers. Conventional feed injection and fraction collection systems have been replaced with customized components facilitating simultaneous separation and online monitoring with the ultimate objective of application of an optimizing controller. Injection volume, cycle time, desorbent flow rate, feed concentration, and three cut intervals are considered as decision variables. A multi-objective optimization technique based on genetic algorithm (GA) is adopted to achieve maximum productivity and minimum desorbent requirement in the region constrained by product specifications and hardware limitations. The optimization results along with the contribution of decision variables are discussed using Pareto fronts that identify non-dominated solutions. Optimization results of a similar simulated moving bed process have also been included to facilitate comparison with a continuous chromatographic process. PMID:22364669

  4. Optimization of an improved single-column chromatographic process for the separation of enantiomers.

    PubMed

    Kazi, Monzure-Khoda; Medi, Bijan; Amanullah, Mohammad

    2012-03-30

    This work addresses optimization of an improved single-column chromatographic (ISCC) process for the separation of guaifenesin enantiomers. Conventional feed injection and fraction collection systems have been replaced with customized components facilitating simultaneous separation and online monitoring with the ultimate objective of application of an optimizing controller. Injection volume, cycle time, desorbent flow rate, feed concentration, and three cut intervals are considered as decision variables. A multi-objective optimization technique based on genetic algorithm (GA) is adopted to achieve maximum productivity and minimum desorbent requirement in the region constrained by product specifications and hardware limitations. The optimization results along with the contribution of decision variables are discussed using Pareto fronts that identify non-dominated solutions. Optimization results of a similar simulated moving bed process have also been included to facilitate comparison with a continuous chromatographic process.

  5. Separation of technetium and rare earth metals for co-decontamination process

    SciTech Connect

    Riddle, Catherine; Martin, Leigh

    2015-05-01

    Poster. In the US there are several technologies under consideration for the separation of the useful components in used nuclear fuel. One such process is the co-decontamination process to separate U, Np and Pu in a single step and produce a Np/ Pu and a U product stream. Although the behavior of the actinide elements is reasonably well defined in this system, the same is not true for the fission products, mainly Zr, Mo, Ru and Tc. As these elements are cationic and anionic they may interact with each other to extract in a manner not predicted by empirical models such as AMUSE. This poster presentation will discuss the initial results of batch contact testing under flowsheet conditions and as a function of varying acidity and flowsheet conditions to optimize recovery of Tc and minimize extraction of Mo, Zr and Ru with the goal of developing a better understanding of the behavior of these elements in the co-decontamination process.

  6. Spectroscopic and physicochemical measurements for on-line monitoring of used nuclear fuel separation processes

    SciTech Connect

    Nee, Ko; Nilsson, M.; Bryan, S.; Levitskaia, T.

    2013-07-01

    Separation processes for used nuclear fuel are often complicated and challenging due to the high constraints in purity of the products and safeguards of the process streams. In order to achieve a safe, secure and efficient separation process, the liquid streams in the separation process require close monitoring. Due to the high radiation environment, sampling of the materials is difficult. Availability of a detection technique that is remote, non-destructive and can avoid time-delay caused by retrieving samples would be beneficial and could minimize the exposure to personnel and provide material accountancy to avoid diversion (non-proliferation). For example, Ultra Violet (UV), Visible (Vis), Near-Infrared (NIR) and Raman spectroscopy that detect and quantify elements present in used nuclear fuel, e.g. lanthanides, actinides and molecules such as nitrate, can be used. In this work, we have carried out NIR and Raman spectroscopy to study aqueous solutions composed of different concentrations of nitric acid, sodium nitrate, and neodymium at varied temperatures. A chemometric model for online monitoring based on the PLS-Toolbox (MATLAB) software has been developed and validated to provide chemical composition of process streams based on spectroscopic data. In conclusion, both of our NIR and Raman spectra were useful for H{sup +} and NO{sub 3} prediction, and only NIR was helpful for the Nd{sup 3+} prediction.

  7. Rubber-modified epoxies: Analysis of the phase-separation process

    SciTech Connect

    Verchere, D.; Sautereau, H.; Pascault, J.P.; Moschiar, S.M.; Riccardi, C.C.; Williams, R.J.J.

    1993-12-31

    The phase-separation process of a diepoxide based on bisphenol A diglycidyl ether cured with a cycloaliphatic diamine in the presence of an epoxy-terminated butadiene-acrylonitrile random copolymer (ETBN) was experimentally studied and theoretically simulated. The increase in the average molecular weight of the epoxy-amine polymer is shown to be the main thermodynamic factor leading to phase separation. The competition between nucleation-growth and spinodal decomposition is analyzed. Low values of interfacial tensions and polymerization rates favor the first mechanism in most cases. A secondary phase separation must occur inside the dispersed particles, leading to a segregated epoxy-amine phase. The theoretical simulation explains the increase of the average diameter of dispersed-phase particles with increasing polymerization temperature. The volume fraction of dispersed phase is the dominating factor affecting fracture toughness. 49 refs., 16 figs.

  8. Insights Into Precipitation Processes As Revealed By Profiling Radar, Disdrometer and Aircraft Observations During The MC3E Campaign.

    NASA Astrophysics Data System (ADS)

    Giangrande, S. E.; Toto, T.; Mishra, S.; Ryzhkov, A.; Bansemer, A.; Kumjian, M.

    2014-12-01

    The Midlatitude Continental Convective Clouds Experiment (MC3E) was a collaborative campaign led by the National Aeronautic and Space Administration's (NASA's) Global Precipitation Measurement (GPM) mission and the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) program. This campaign was held at the DOE ARM Southern Great Plains (SGP) Central Facility (CF) in north-central Oklahoma, with the programs joining forces to deploy an extensive array of airborne, radiosonde and ground-based instrumentation towards an unprecedented set of deep convective environment and cloud property observations. An overarching motivation was to capitalize on the wealth of aircraft observations and new multi-frequency dual-polarization radars to provide insights for improving the treatments of cloud processes in convective models. This study considers a coupled aircraft, radar and surface disdrometer approach for identifying key cloud processes and linking those to possible radar-based microphysical fingerprints and/or cloud properties. Our emphasis is on the MC3E observations collected during aircraft spirals over the column of the ARM CF. We focus on those spirals associated with radar 'bright band' signatures and Doppler spectral anomalies observed within trailing stratifrom precipitation. Two cases are highlighted, one following a weaker convective event, and one following a stronger squall line. For each event, we investigate the usefulness of radar to inform on processes including aggregation and riming as viewed by the vertically-pointing ARM wind profiler (915 MHz) and cloud radar Doppler spectral observations (35 GHz). Matching dual-polarization radar signatures from nearby cm-wavelength radar are also consulted for complementary insights. For one event, the successive Citation II aircraft spirals through the melting layer and associated ground observations indicate a fortunate capture of the transition from a region of riming to one favoring aggregation

  9. Optimizing and developing a continuous separation system for the wet process separation of aluminum and polyethylene in aseptic composite packaging waste.

    PubMed

    Yan, Dahai; Peng, Zheng; Liu, Yuqiang; Li, Li; Huang, Qifei; Xie, Minghui; Wang, Qi

    2015-01-01

    The consumption of milk in China is increasing as living standards rapidly improve, and huge amounts of aseptic composite milk packaging waste are being generated. Aseptic composite packaging is composed of paper, polyethylene, and aluminum. It is difficult to separate the polyethylene and aluminum, so most of the waste is currently sent to landfill or incinerated with other municipal solid waste, meaning that enormous amounts of resources are wasted. A wet process technique for separating the aluminum and polyethylene from the composite materials after the paper had been removed from the original packaging waste was studied. The separation efficiency achieved using different separation reagents was compared, different separation mechanisms were explored, and the impacts of a range of parameters, such as the reagent concentration, temperature, and liquid-solid ratio, on the separation time and aluminum loss ratio were studied. Methanoic acid was found to be the optimal separation reagent, and the suitable conditions were a reagent concentration of 2-4 mol/L, a temperature of 60-80°C, and a liquid-solid ratio of 30 L/kg. These conditions allowed aluminum and polyethylene to be separated in less than 30 min, with an aluminum loss ratio of less than 3%. A mass balance was produced for the aluminum-polyethylene separation system, and control technique was developed to keep the ion concentrations in the reaction system stable. This allowed a continuous industrial-scale process for separating aluminum and polyethylene to be developed, and a demonstration facility with a capacity of 50t/d was built. The demonstration facility gave polyethylene and aluminum recovery rates of more than 98% and more than 72%, respectively. Separating 1t of aluminum-polyethylene composite packaging material gave a profit of 1769 Yuan, meaning that an effective method for recycling aseptic composite packaging waste was achieved.

  10. Process for separating a fluid feed mixture containing hydrocarbon oil and an organic solvent

    SciTech Connect

    Bitter, J.G.A.; Haan, J.P.

    1989-03-07

    This patent describes a process for separating a fluid feed mixture containing a hydrocarbon lubricating base oil and an organic solvent selected from furfural and mixture of toluene and methyl ethyl ketone which process comprises subjecting the fluid feed mixture to reverse osmosis in a reverse osmosis zone with a membrane comprising a layer of a silicone polymer. The process provides a retentate stream having an organic solvent content higher than the feed mixture, and a permeate stream having an organic solvent content less than the amount of solvent in the feed mixture, and permits recovering hydrocarbon oil from the permeate stream.

  11. Effect of Inlet and Outlet Flow Conditions on Natural Gas Parameters in Supersonic Separation Process

    PubMed Central

    Yang, Yan; Wen, Chuang; Wang, Shuli; Feng, Yuqing

    2014-01-01

    A supersonic separator has been introduced to remove water vapour from natural gas. The mechanisms of the upstream and downstream influences are not well understood for various flow conditions from the wellhead and the back pipelines. We used a computational model to investigate the effect of the inlet and outlet flow conditions on the supersonic separation process. We found that the shock wave was sensitive to the inlet or back pressure compared to the inlet temperature. The shock position shifted forward with a higher inlet or back pressure. It indicated that an increasing inlet pressure declined the pressure recovery capacity. Furthermore, the shock wave moved out of the diffuser when the ratio of the back pressure to the inlet one was greater than 0.75, in which the state of the low pressure and temperature was destroyed, resulting in the re-evaporation of the condensed liquids. Natural gas would be the subsonic flows in the whole supersonic separator, if the mass flow rate was less than the design value, and it could not reach the low pressure and temperature for the condensation and separation of the water vapor. These results suggested a guidance mechanism for natural gas supersonic separation in various flow conditions. PMID:25338207

  12. Effect of inlet and outlet flow conditions on natural gas parameters in supersonic separation process.

    PubMed

    Yang, Yan; Wen, Chuang; Wang, Shuli; Feng, Yuqing

    2014-01-01

    A supersonic separator has been introduced to remove water vapour from natural gas. The mechanisms of the upstream and downstream influences are not well understood for various flow conditions from the wellhead and the back pipelines. We used a computational model to investigate the effect of the inlet and outlet flow conditions on the supersonic separation process. We found that the shock wave was sensitive to the inlet or back pressure compared to the inlet temperature. The shock position shifted forward with a higher inlet or back pressure. It indicated that an increasing inlet pressure declined the pressure recovery capacity. Furthermore, the shock wave moved out of the diffuser when the ratio of the back pressure to the inlet one was greater than 0.75, in which the state of the low pressure and temperature was destroyed, resulting in the re-evaporation of the condensed liquids. Natural gas would be the subsonic flows in the whole supersonic separator, if the mass flow rate was less than the design value, and it could not reach the low pressure and temperature for the condensation and separation of the water vapor. These results suggested a guidance mechanism for natural gas supersonic separation in various flow conditions.

  13. Separating and stabilizing phosphate from high-level radioactive waste: process development and spectroscopic monitoring.

    PubMed

    Lumetta, Gregg J; Braley, Jenifer C; Peterson, James M; Bryan, Samuel A; Levitskaia, Tatiana G

    2012-06-01

    Removing phosphate from alkaline high-level waste sludges at the Department of Energy's Hanford Site in Washington State is necessary to increase the waste loading in the borosilicate glass waste form that will be used to immobilize the highly radioactive fraction of these wastes. We are developing a process which first leaches phosphate from the high-level waste solids with aqueous sodium hydroxide, and then isolates the phosphate by precipitation with calcium oxide. Tests with actual tank waste confirmed that this process is an effective method of phosphate removal from the sludge and offers an additional option for managing the phosphorus in the Hanford tank waste solids. The presence of vibrationally active species, such as nitrate and phosphate ions, in the tank waste processing streams makes the phosphate removal process an ideal candidate for monitoring by Raman or infrared spectroscopic means. As a proof-of-principle demonstration, Raman and Fourier transform infrared (FTIR) spectra were acquired for all phases during a test of the process with actual tank waste. Quantitative determination of phosphate, nitrate, and sulfate in the liquid phases was achieved by Raman spectroscopy, demonstrating the applicability of Raman spectroscopy for the monitoring of these species in the tank waste process streams. PMID:22571620

  14. Separating and stabilizing phosphate from high-level radioactive waste: process development and spectroscopic monitoring.

    PubMed

    Lumetta, Gregg J; Braley, Jenifer C; Peterson, James M; Bryan, Samuel A; Levitskaia, Tatiana G

    2012-06-01

    Removing phosphate from alkaline high-level waste sludges at the Department of Energy's Hanford Site in Washington State is necessary to increase the waste loading in the borosilicate glass waste form that will be used to immobilize the highly radioactive fraction of these wastes. We are developing a process which first leaches phosphate from the high-level waste solids with aqueous sodium hydroxide, and then isolates the phosphate by precipitation with calcium oxide. Tests with actual tank waste confirmed that this process is an effective method of phosphate removal from the sludge and offers an additional option for managing the phosphorus in the Hanford tank waste solids. The presence of vibrationally active species, such as nitrate and phosphate ions, in the tank waste processing streams makes the phosphate removal process an ideal candidate for monitoring by Raman or infrared spectroscopic means. As a proof-of-principle demonstration, Raman and Fourier transform infrared (FTIR) spectra were acquired for all phases during a test of the process with actual tank waste. Quantitative determination of phosphate, nitrate, and sulfate in the liquid phases was achieved by Raman spectroscopy, demonstrating the applicability of Raman spectroscopy for the monitoring of these species in the tank waste process streams.

  15. Separating and Stabilizing Phosphate from High-Level Radioactive Waste: Process Development and Spectroscopic Monitoring

    SciTech Connect

    Lumetta, Gregg J.; Braley, Jenifer C.; Peterson, James M.; Bryan, Samuel A.; Levitskaia, Tatiana G.

    2012-05-09

    Removing phosphate from alkaline high-level waste sludges at the Department of Energy's Hanford Site in Washington State is necessary to increase the waste loading in the borosilicate glass waste form that will be used to immobilize the highly radioactive fraction of these wastes. We are developing a process which first leaches phosphate from the high-level waste solids with aqueous sodium hydroxide, and then isolates the phosphate by precipitation with calcium oxide. Tests with actual tank waste confirmed that this process is an effective method of phosphate removal from the sludge and offers an additional option for managing the phosphorus in the Hanford tank waste solids. The presence of vibrationally active species, such as nitrate and phosphate ions, in the tank waste processing streams makes the phosphate removal process an ideal candidate for monitoring by Raman or infrared spectroscopic means. As a proof-of-principle demonstration, Raman and Fourier transform infrared (FTIR) spectra were acquired for all phases during a test of the process with actual tank waste. Quantitative determination of phosphate, nitrate, and sulfate in the liquid phases was achieved by Raman spectroscopy, demonstrating the applicability of Raman spectroscopy for the monitoring of these species in the tank waste process streams.

  16. Are Phonological Processes Separate from the Processes Underlying Naming Speed in a Shallow Orthography?

    ERIC Educational Resources Information Center

    Lopez-Escribano, Carmen; Katzir, Tami

    2008-01-01

    Introduction: The present study examined the contributions of phonological decoding skills and rapid naming to the prediction of reading skills in Spanish-speaking children with dyslexia. Method: Thirty-eight dyslexic readers with phonological decoding processing deficits (mean age 9;11) were assessed on reading speed, reading comprehension, word…

  17. Screening of bacteria for self-healing of concrete cracks and optimization of the microbial calcium precipitation process.

    PubMed

    Zhang, J L; Wu, R S; Li, Y M; Zhong, J Y; Deng, X; Liu, B; Han, N X; Xing, F

    2016-08-01

    A novel high-throughput strategy was developed to determine the calcium precipitation activity (CPA) of mineralization bacteria used for self-healing of concrete cracks. A bacterial strain designated as H4 with the highest CPA of 94.8 % was screened and identified as a Bacillus species based on 16S rDNA sequence and phylogenetic tree analysis. Furthermore, the effects of certain influential factors on the microbial calcium precipitation process of H4 were evaluated. The results showed that lactate and nitrate are the best carbon and nitrogen sources, with optimal concentrations of approximately 25 and 18 mM, respectively. The H4 strain is able to maintain a high CPA in the pH range of 9.5-11.0, and a suitable initial spore concentration is 4.0 × 10(7) spores/ml. Moreover, an ambient Ca(2+) concentration greater than 60 mM resulted in a serious adverse impact not only on the CPA but also on the growth of H4, suggesting that the maintenance of the Ca(2+) concentration at a low level is necessary for microbial self-healing of concrete cracks.

  18. Screening of bacteria for self-healing of concrete cracks and optimization of the microbial calcium precipitation process.

    PubMed

    Zhang, J L; Wu, R S; Li, Y M; Zhong, J Y; Deng, X; Liu, B; Han, N X; Xing, F

    2016-08-01

    A novel high-throughput strategy was developed to determine the calcium precipitation activity (CPA) of mineralization bacteria used for self-healing of concrete cracks. A bacterial strain designated as H4 with the highest CPA of 94.8 % was screened and identified as a Bacillus species based on 16S rDNA sequence and phylogenetic tree analysis. Furthermore, the effects of certain influential factors on the microbial calcium precipitation process of H4 were evaluated. The results showed that lactate and nitrate are the best carbon and nitrogen sources, with optimal concentrations of approximately 25 and 18 mM, respectively. The H4 strain is able to maintain a high CPA in the pH range of 9.5-11.0, and a suitable initial spore concentration is 4.0 × 10(7) spores/ml. Moreover, an ambient Ca(2+) concentration greater than 60 mM resulted in a serious adverse impact not only on the CPA but also on the growth of H4, suggesting that the maintenance of the Ca(2+) concentration at a low level is necessary for microbial self-healing of concrete cracks. PMID:26883348

  19. A Coupled GCM-Cloud Resolving Modeling System, and A Regional Scale Model to Study Precipitation Processes

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo

    2006-01-01

    Recent GEWEX Cloud System Study (GCSS) model comparison projects have indicated that cloud-resolving models (CRMs) agree with observations better than traditional single-column models in simulating various types of clouds and cloud systems from different geographic locations. Current and future NASA satellite programs can provide cloud, precipitation, aerosol and other data at very fine spatial and temporal scales. It requires a coupled global circulation model (GCM) and cloud-scale model (termed a super-parameterization or multi-scale modeling framework, MMF) to use these satellite data to improve the understanding of the physical processes that are responsible for the variation in global and regional climate and hydrological systems. The use of a GCM will enable global coverage, and the use of a CRM will allow for better and more sophisticated physical parameterization. NASA satellite and field campaign cloud related datasets can provide initial conditions as well as validation for both the MMF and CRMs. The Goddard MMF is based on the 2D Goddard Cumulus Ensemble (GCE) model and the Goddard finite volume general circulation model (fvGCM), and it has started production runs with two years results (1998 and 1999). Also, at Goddard, we have implemented several Goddard microphysical schemes (21CE, several 31CE), Goddard radiation (including explicitly calculated cloud optical properties), and Goddard Land Information (LIS, that includes the CLM and NOAH land surface models) into a next generation regional scale model, WRF. In this talk, I will present: (1) A brief review on GCE model and its applications on precipitation processes (microphysical and land processes), (2) The Goddard MMF and the major difference between two existing MMFs (CSU MMF and Goddard MMF), and preliminary results (the comparison with traditional GCMs), and (3) A discussion on the Goddard WRF version (its developments and applications).

  20. A Coupled GCM-Cloud Resolving Modeling System, and a Regional Scale Model to Study Precipitation Processes

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo

    2006-01-01

    Recent GEWEX Cloud System Study (GCSS) model comparison projects have indicated that cloud-resolving models (CRMs) agree with observations better than traditional single-column models in simulating various types of clouds and cloud systems from different geographic locations. Current and future NASA satellite programs can provide cloud, precipitation, aerosol and other data at very fine spatial and temporal scales. It requires a coupled global circulation model (GCM) and cloud-scale model (termed a super-parameterization or multi-scale modeling framework, MMF) to use these satellite data to improve the understanding of the physical processes that are responsible for the variation in global and regional climate and hydrological systems. The use of a GCM will enable global coverage, and the use of a CRM will allow for better and more sophisticated physical parameterization. NASA satellite and field campaign cloud related datasets can provide initial conditions as well as validation for both the MMF and CFWs. The Goddard MMF is based on the 2D Goddard Cumulus Ensemble (GCE) model and the Goddard finite volume general circulation model (fvGCM), and it has started production runs with two years results (1 998 and 1999). In this talk, I will present: (1) A brief review on GCE model and its applications on precipitation processes (microphysical and land processes), (2) The Goddard MMF and the major difference between two existing MMFs (CSU MMF and Goddard MMF), and preliminary results (the comparison with traditional GCMs), and (3) A discussion on the Goddard WRF version (its developments and applications).

  1. A Coupled GCM-Cloud Resolving Modeling System, and a Regional Scale Model to Study Precipitation Processes

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo

    2007-01-01

    Recent GEWEX Cloud System Study (GCSS) model comparison projects have indicated that cloud-resolving models (CRMs) agree with observations better than traditional single-column models in simulating various types of clouds and cloud systems from different geographic locations. Current and future NASA satellite programs can provide cloud, precipitation, aerosol and other data at very fine spatial and temporal scales. It requires a coupled global circulation model (GCM) and cloud-scale model (termed a superparameterization or multi-scale modeling framework, MMF) to use these satellite data to improve the understanding of the physical processes that are responsible for the variation in global and regional climate and hydrological systems. The use of a GCM will enable global coverage, and the use of a CRM will allow for better and more sophisticated physical parameterization. NASA satellite and field campaign cloud related datasets can provide initial conditions as well as validation for both the MMF and CRMs. The Goddard MMF is based on the 2D Goddard Cumulus Ensemble (GCE) model and the Goddard finite volume general circulation model (fvGCM), and it has started production runs with two years results (1998 and 1999). Also, at Goddard, we have implemented several Goddard microphysical schemes (2ICE, several 31CE), Goddard radiation (including explicitly calculated cloud optical properties), and Goddard Land Information (LIS, that includes the CLM and NOAH land surface models) into a next generatio11 regional scale model, WRF. In this talk, I will present: (1) A brief review on GCE model and its applications on precipitation processes (microphysical and land processes), (2) The Goddard MMF and the major difference between two existing MMFs (CSU MMF and Goddard MMF), and preliminary results (the comparison with traditional GCMs), and (3) A discussion on the Goddard WRF version (its developments and applications).

  2. Microbially induced carbonate precipitation (MICP) by denitrification as ground improvement method - Process control in sand column experiments

    NASA Astrophysics Data System (ADS)

    Pham, Vinh; van Paassen, Leon; Nakano, Akiko; Kanayama, Motohei; Heimovaara, Timo

    2013-04-01

    Calcite precipitation induced by microbes has been proven to be efficient in stabilizing granular soils, especially with urea hydrolysis, as it has been successfully demonstrated in a pilot application 2010. However, as a byproduct highly concentrated ammonium chloride (NH4Cl) solution is produced, which has to be removed and disposed and forms a significant disadvantage of the technique that makes an alternative process like denitrification preferred. The proof of principle of microbially induced calcite precipitation (MICP) by denitrification has been demonstrated by Van Paassen et al (2010) who suggested that instead of producing waste as a byproduct, different pre-treated waste streams could be used as substrates for in situ growth of denitrifying bacteria and simultaneous cementation without producing waste to be removed. In this study sand column experiments are performed in which calcium carbonate was successfully precipitated by indigenous denitrifying micro-organisms, which were supplied weekly with a pulse of a substrate solution containing calcium acetate and calcium nitrate. Besides the production of calcite and the growth of bacteria in biofilms, the reduction of nitrate resulted in the production of (nitrogen) gas. It was observed that this gas partly fills up the pore space and consequently contributed to a reduction of the permeability of the treated sand. The presence of gas in the pore space affected the flow of the injected substrates and influenced to the distribution of calcium carbonate. The effect of the mean particle size (D50) on the flow and transport of solutes and gas in the porous media has been evaluated by treating several columns with varying grain size distribution and comparing the change in permeability after each incubation period and analyzing the distribution of the gas throughout the columns using X-ray computed tomography (CT) scanning. The present results show that there is a considerable decrease of permeability - a

  3. Precipitation and dissolution of calcium carbonate: key processes bridging the bio- and geosciences (Vladimir Ivanovich Vernadsky Medal Lecture)

    NASA Astrophysics Data System (ADS)

    Gattuso, J.-P.

    2012-04-01

    In this Vladimir Ivanovich Vernadsky medal lecture, I will focus on the biogeochemical cycle of calcium carbonate (CaCO3) which is arguably one of the best example of a set processes that bridge the bio- and geosciences. The main reactions involved are calcification and dissolution that, respectively, manufacture and destroy calcium carbonate. Biology is intimately involved in these two processes which are key controls of the Earth's climate and leave remains that are of great use to human societies (as building materials) and geoscientists. I will illustrate the bridge between the bio- and geosciences by providing brief examples for each of the following four issues. (1) The marine cycle of CaCO3 and its relationship with climate. The release of CO2 by the precipitation of calcium carbonate and the uptake of CO2 by its dissolution are important controls of atmospheric CO2 and climate. The vertical distribution of Ψ, the ratio of CO2 released/used per CaCO3 precipitated/dissolved in the ocean will be shown to be consistent with the Högbom-Urey reactions. (2) The use of CaCO3 in paleooceanography. The remains of calcium carbonate shells and skeletons are wonderful archives of past environmental changes. Their isotopic composition and the concen-tration of trace elements are invaluable in the reconstruction of past climate. I will address the challenge of calibrating one of the proxies used to reconstruct past ocean pH. (3) The challenge of understanding calcification. Despite having been investigated for decades, many aspects of the physiological and molecular processes involved in calcification by marine organisms remain obscure. Recent breakthroughs, mostly on reef-building corals, will be briefly reviewed. (4) The response of calcification and dissolution to environmental change. The critical importance of CaCO3 precipitation and dissolution as climate controls makes it vital to understand their response to global environmental changes such as ocean warming and

  4. NOVEL COMPOSITE MEMBRANES FOR HYDROGEN SEPARATION IN GASIFICATION PROCESSES IN VISION 21 ENERGY PLANTS

    SciTech Connect

    Michael Schwartz

    2004-12-01

    This report describes the work performed, accomplishments and conclusion obtained from the project entitled ''Novel Composite Membranes for Hydrogen Separation in Gasification Processes in Vision 21 Energy Plants'' under the United States Department of Energy Contract DE-FC26-01NT40973. ITN Energy Systems was the prime contractor. Team members included: the Idaho National Engineering and Environmental Laboratory; Nexant Consulting; Argonne National Laboratory and Praxair. The objective of the program was to develop a novel composite membrane structure for hydrogen separation as a key technology module within the future ''Vision 21'' fossil fuel plants. The separation technology module is targeted for use within the gasification module of the ''Vision 21'' fossil fuel plant. The high performance and low-cost manufacturing of the proposed technology will benefit the deployment of ''Vision 21'' fossil fuel plant processes by improving the energy efficiency, flexibility and environmental performance of these plants. Of particular importance is that this technology will also produce a stream of pure carbon dioxide. This allows facile sequestration or other use of this greenhouse gas. These features will benefit the U.S. in allowing for the continued use of domestic fossil fuels in a more energy efficient and environmentally acceptable manner. The program developed and evaluated composite membranes and catalysts for hydrogen separation. Components of the monolithic modules were fabricated by plasma spray processing. The engineering and economic characteristics of the proposed Ion Conducting Ceramic Membrane (ICCM) approach, including system integration issues, were also assessed. This resulted in a comprehensive evaluation of the technical and economic feasibility of integration schemes of ICCM hydrogen separation technology within Vision 21 fossil fuel plants. Several results and conclusion were obtained during this program. In the area of materials synthesis, novel

  5. Process for the continuous separation of maleic anhydride from process gases

    SciTech Connect

    Ceisel, S.C.; Conrad, J.F.; Lestan, E.M.; Nelson, A.P.

    1990-07-17

    This patent describes a process for recovery of maleic anhydride from a gaseous mixture of a reactor effluent gas stream containing maleic anhydride. It comprises: contacting the mixture with maleic anhydride in a gas phase wherein the maleic anhydride is injected into a gas stream effluent from an oxidation reactor. The gas stream effluent is at a temperature of from about 200{degrees}F. to about 350{degrees}F., and maleic anhydride is recovered in a condenser.

  6. Spectroscopic methods of process monitoring for safeguards of used nuclear fuel separations

    NASA Astrophysics Data System (ADS)

    Warburton, Jamie Lee

    To support the demonstration of a more proliferation-resistant nuclear fuel processing plant, techniques and instrumentation to allow the real-time, online determination of special nuclear material concentrations in-process must be developed. An ideal materials accountability technique for proliferation resistance should provide nondestructive, realtime, on-line information of metal and ligand concentrations in separations streams without perturbing the process. UV-Visible spectroscopy can be adapted for this precise purpose in solvent extraction-based separations. The primary goal of this project is to understand fundamental URanium EXtraction (UREX) and Plutonium-URanium EXtraction (PUREX) reprocessing chemistry and corresponding UV-Visible spectroscopy for application in process monitoring for safeguards. By evaluating the impact of process conditions, such as acid concentration, metal concentration and flow rate, on the sensitivity of the UV-Visible detection system, the process-monitoring concept is developed from an advanced application of fundamental spectroscopy. Systematic benchtop-scale studies investigated the system relevant to UREX or PUREX type reprocessing systems, encompassing 0.01-1.26 M U and 0.01-8 M HNO3. A laboratory-scale TRansUranic Extraction (TRUEX) demonstration was performed and used both to analyze for potential online monitoring opportunities in the TRUEX process, and to provide the foundation for building and demonstrating a laboratory-scale UREX demonstration. The secondary goal of the project is to simulate a diversion scenario in UREX and successfully detect changes in metal concentration and solution chemistry in a counter current contactor system with a UV-Visible spectroscopic process monitor. UREX uses the same basic solvent extraction flowsheet as PUREX, but has a lower acid concentration throughout and adds acetohydroxamic acid (AHA) as a complexant/reductant to the feed solution to prevent the extraction of Pu. By examining

  7. Critical Material and Process Issues for CO2 Separation from Coal-Powered Plants

    SciTech Connect

    Liu, Wei; King, David L.; Liu, Jun; Johnson , Brad R.; Wang, Yong; Yang, Zhenguo

    2009-04-30

    Concentrating CO2 from the dilute coal combustion or gasification gas stream to a level suitable for sequestration purposes represents a major cost factor to curtail CO2 emissions by capture and sequestration schemes. This paper provides a short review of CO2 capture incentives, current separation processes, and research progress of various new technologies. Technically, CO2 can be separated out of a gas mixture by all the methods discussed in this work, such as distillation, absorption, adsorption, gas/solid reaction, membrane, electrochemical pump, hydrate formation, etc. The challenge lies in determining which approach is the most practical or feasible, and ultimately the most cost-efficient. Important material issues and their impacts on the process viability will be discussed.

  8. Critical material and process issues for CO{sub 2} separation from coal-powered plants

    SciTech Connect

    Liu, W.; King, D.; Liu, J.; Johnson, B.; Wang, Y.; Yang, Z.G.

    2009-04-15

    Concentrating CO{sub 2} from the dilute coal combustion or gasification gas stream to a level suitable for sequestration purposes represents a major cost factor to curtail CO{sub 2} emissions by capture and sequestration. This paper provides a short review of CO{sub 2} capture incentives, current separation processes, and research progress of various new technologies. Scientifically, CO{sub 2} can be separated from a gas mixture by all the methods reviewed in this work: distillation, absorption, adsorption, gas/solid reaction, membrane, electrochemical pump, hydrate formation, etc. The challenge lies in practical feasibility and ultimately the cost. Important material issues and their impacts to the process viability will be discussed.

  9. Laboratory Tests on Post-Filtration Precipitation in the WTP Pretreatment Process

    SciTech Connect

    Russell, Renee L.; Peterson, Reid A.; Rinehart, Donald E.; Crum, Jarrod V.

    2009-11-20

    Pacific Northwest National Laboratory (PNNL) has been tasked by Bechtel National Inc. (BNI) on the River Protection Project-Hanford Tank Waste Treatment and Immobilization Plant (RPP-WTP) project to perform research and development activities to resolve technical issues identified for the Pretreatment Facility (PTF). The Pretreatment Engineering Platform (PEP) was designed, constructed, and operated as part of a plan to respond to issue M12, "Undemonstrated Leaching Processes," of the External Flowsheet Review Team (EFRT) issue response plan (Barnes et al. 2006). The PEP is a 1/4.5-scale test platform designed to simulate the WTP pretreatment caustic leaching, oxidative leaching, ultrafiltration solids concentration, and slurry washing processes. The PEP replicates the WTP leaching processes using prototypic equipment and control strategies. A simplified flow diagram of the PEP system is shown in Figure 1.1. Two operating scenarios are currently being evaluated for the ultrafiltration process (UFP) and leaching operations. The first scenario has caustic leaching performed in the UFP-2 ultrafiltration feed vessels (i.e., vessel UFP-VSL-T02A in the PEP; and vessels UFP-VSL-00002A and B in the WTP PTF). The second scenario has caustic leaching conducted in the UFP-1 ultrafiltration feed preparation vessels (i.e., vessels UFP-VSL-T01A and B in the PEP; vessels UFP-VSL-00001A and B in the WTP PTF).

  10. Biosorption for the separation of radionuclides from drainage and process waters of the uranium mining industry

    SciTech Connect

    Glombitza, F.; Eckardt, L.; Hummel, A.

    1995-12-31

    Biosorption means the storage of substances at the cell envelope. Different microbial biomasses were tested for the separation of radionuclides from mining waters. Results of a pilot plant demonstrate the ability of these techniques for water cleaning processes. An effluent concentration of lower than 1 mg/l (in most cases 0.1 mg/1) could be realized in a pilot plant by using pure cells of a methylotrophic strain of bacteria as well as using of a fungal mycelia.

  11. Dynamical theory of primary processes of charge separation in the photosynthetic reaction center.

    PubMed

    Lakhno, Victor D

    2005-05-01

    A dynamical theory has been developed for primary separation of charges in the course of photosynthesis. The theory deals with both hopping and superexchange transfer mechanisms. Dynamics of electron transfer from dimeric bacteriochlorophyll to quinone has been calculated. The results obtained agree with experimental data and provide a unified explanation of both the hierarchy of the transfer time in the photosynthetic reaction center and the phenomenon of coherent oscillations accompanying the transfer process.

  12. Intensification of heat and mass transfer by ultrasound: application to heat exchangers and membrane separation processes.

    PubMed

    Gondrexon, N; Cheze, L; Jin, Y; Legay, M; Tissot, Q; Hengl, N; Baup, S; Boldo, P; Pignon, F; Talansier, E

    2015-07-01

    This paper aims to illustrate the interest of ultrasound technology as an efficient technique for both heat and mass transfer intensification. It is demonstrated that the use of ultrasound results in an increase of heat exchanger performances and in a possible fouling monitoring in heat exchangers. Mass transfer intensification was observed in the case of cross-flow ultrafiltration. It is shown that the enhancement of the membrane separation process strongly depends on the physico-chemical properties of the filtered suspensions.

  13. A calcium oxide sorbent process for bulk separation of carbon dioxide

    SciTech Connect

    Harrison, D.P.

    1992-10-01

    Objective is to investigate the feasibility of a high-temperature, high-pressure process for bulk separation of CO[sub 2] from coal- derived gas. An electrobalance reactor was used in Phase I; in Phase II, the switch was made to a fixed-bed reactor with capability for feed and product gas analysis. A gas chromatograph was delivered, installed, and operator training carried out. The sampling valve sequence is discussed.

  14. Process for the separation of sulfur oxides from a gaseous mixture containing sulfur oxides and oxygen

    SciTech Connect

    Derosset, A.J.; Ginger, E.A.

    1980-12-23

    An improved process for the separation of sulfur oxides from a gaseous mixture containing sulfur oxides and oxygen is disclosed. The gaseous mixture is contacted with a solid sulfur oxide acceptor comprising copper, copper oxide, or a mixture thereof dispersed on a carrier material in combination with a platinum group metal component and a component selected from the group consisting of rhenium, germanium and tin.

  15. PROCESS OF TREATING URANIUM HEXAFLUORIDE AND PLUTONIUM HEXAFLUORIDE MIXTURES WITH SULFUR TETRAFLUORIDE TO SEPARATE SAME

    DOEpatents

    Steindler, M.J.

    1962-07-24

    A process was developed for separating uranium hexafluoride from plutonium hexafluoride by the selective reduction of the plutonium hexafluoride to the tetrafluoride with sulfur tetrafluoride at 50 to 120 deg C, cooling the mixture to --60 to -100 deg C, and volatilizing nonreacted sulfur tetrafluoride and sulfur hexafluoride formed at that temperature. The uranium hexafluoride is volatilized at room temperature away from the solid plutonium tetrafluoride. (AEC)

  16. Minor actinide separation: simplification of the DIAMEX-SANEX strategy by means of novel SANEX processes

    SciTech Connect

    Geist, A.; Modolo, G.; Wilden, A.; Kaufholz, P.

    2013-07-01

    The separation of An(III) from PUREX raffinate has previously been demonstrated by applying a DIAMEX process (i.e., co-extraction of An(III) and Ln(III) from HAR) followed by a SANEX process (i.e., selective extraction of An(III) from the DIAMEX product containing An(III) + Ln(III)). In line with process intensification issues, more compact processes have been developed: Recently, a 1c-SANEX process test was successfully performed, directly extracting An(III) from PUREX HAR. More recently, a new i-SANEX process was successfully tested. This process is based on the co-extraction of An(III) + Ln(III) into a TODGA solvent, followed by a selective back-extraction of An(III) by a water soluble complexing agent, in this case SO{sub 3}-Ph-BTP. In both cases, good recoveries were achieved, and very pure product solutions were obtained. However, both 1c-SANEX and i-SANEX used non-CHON chemicals. Nevertheless, these processes are a simplification to the DIAMEX + SANEX process as only one solvent is used. Finally, the new i-SANEX process is the most compact process. (authors)

  17. 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.

  18. Distinct constrictive processes, separated in time and space, divide caulobacter inner and outer membranes.

    PubMed

    Judd, Ellen M; Comolli, Luis R; Chen, Joseph C; Downing, Kenneth H; Moerner, W E; McAdams, Harley H

    2005-10-01

    Cryoelectron microscope tomography (cryoEM) and a fluorescence loss in photobleaching (FLIP) assay were used to characterize progression of the terminal stages of Caulobacter crescentus cell division. Tomographic cryoEM images of the cell division site show separate constrictive processes closing first the inner membrane (IM) and then the outer membrane (OM) in a manner distinctly different from that of septum-forming bacteria. FLIP experiments had previously shown cytoplasmic compartmentalization (when cytoplasmic proteins can no longer diffuse between the two nascent progeny cell compartments) occurring 18 min before daughter cell separation in a 135-min cell cycle so the two constrictive processes are separated in both time and space. In the very latest stages of both IM and OM constriction, short membrane tether structures are observed. The smallest observed pre-fission tethers were 60 nm in diameter for both the inner and outer membranes. Here, we also used FLIP experiments to show that both membrane-bound and periplasmic fluorescent proteins diffuse freely through the FtsZ ring during most of the constriction procession.

  19. Application of Electromagnetic (EM) Separation Technology to Metal Refining Processes: A Review

    NASA Astrophysics Data System (ADS)

    Zhang, Lifeng; Wang, Shengqian; Dong, Anping; Gao, Jianwei; Damoah, Lucas Nana Wiredu

    2014-12-01

    Application of electromagnetic (EM) force to metal processing has been considered as an emerging technology for the production of clean metals and other advanced materials. In the current paper, the principle of EM separation was introduced and several schemes of imposing EM field, such as DC electric field with a crossed steady magnetic field, AC electric field, AC magnetic field, and traveling magnetic field were reviewed. The force around a single particle or multi-particles and their trajectories in the conductive liquid under EM field were discussed. Applications of EM technique to the purification of different liquid metals such as aluminum, zinc, magnesium, silicon, copper, and steel were summarized. Effects of EM processing parameters, such as the frequency of imposed field, imposed magnetic flux density, processing time, particle size, and the EM unit size on the EM purification efficiency were discussed. Experimental and theoretical investigations have showed that the separation efficiency of inclusions from the molten aluminum using EM purification could as high as over 90 pct. Meanwhile, the EM purification was also applied to separate intermetallic compounds from metal melt, such as α-AlFeMnSi-phase from the molten aluminum. And then the potential industrial application of EM technique was proposed.

  20. K Basin Sludge Conditioning Process Testing Partitioning of PCBs in Dissolver Solution After Neutralization/Precipitation (Caustic Adjustment)

    SciTech Connect

    Schmidt, A.J.; Thornton, B.M.; Hoppe, E.W.; Mong, G.M.; Silvers, K.L.; Slate, S.O.

    1999-01-04

    The purpose of the work described in this report was to gain a better understanding of how PCB congeners present in a simulated K Basin sludge dissolver solution will partition upon neutralization and precipitation (i.e., caustic adjustment). In a previous study (Mong et al. 1998),the entire series of sludge conditioning steps (acid dissolution, filtration, and caustic adjustment) were examined during integrated testing. In the work described here, the caustic adjustment step was isolated to examine the fate of PCBs in more detail within this processing step. For this testing, solutions of dissolver simulant (containing no solids) with a known initial concentration of PCB congeners were neutralized with caustic to generate a clarified supernatant and a settled sludge phase. PCBs were quantified in each phase (including the PCBs associated with the test vessel rinsates), and material balance information was collected.

  1. Insights into collaborative separation process of photogenerated charges and superior performance of solar cells

    NASA Astrophysics Data System (ADS)

    Liu, Xiangyang; Wang, Shun; Zheng, Haiwu; Gu, Yuzong

    2016-07-01

    ZnO nanowires/Cu4Bi4S9 (ZnO/CBS) and ZnO nanowires/CBS-graphene nanoplates (ZnO/CBS-GNs), as well as two types of solar cells were prepared. The photovoltaic responses of CBS-GNs and ZnO/CBS-GNs can be improved with incorporation of GNs. The transient surface photovoltage (TPV) can provide detailed information on the separation and transport of photogenerated carriers. The multichannel separation process from the TPVs indicates that the macro-photoelectric signals can be attributed to the photogenerated charges separated at the interface of CBS/GNs, rather than CBS/ZnO. The multi-interfacial recombination is the major carrier loss, and the hole selective p-V2O5 can efficiently accelerate the charge extraction to the external circuit. The ZnO/CBS-GNs cell exhibits the superior performance, and the highest efficiency is 10.9%. With the adequate interfaces of CBS/GNs, GNs conductive network, energy level matching, etc., the excitons can easily diffuse to the interface of CBS/GNs, and the separated electrons and holes can be collected quickly, inducing the high photoelectric properties. Here, a facile strategy for solid state solar cells with superior performance presents a potential application.

  2. Study of the instabilities induced near the separator plate in atomization processes

    NASA Astrophysics Data System (ADS)

    Fuster, Daniel; Zaleski, Stephane

    2008-11-01

    This work presents current advances in the simulation of the primary atomization zone, paying a special attention to the effect of the separator plate on the flow patterns observed downstream. Gerris, a CFD Open Source code, is used to perform the simulations. The methods implemented on it combining adaptive quad/octree spatial discretisation, geometrical Volume-Of-Fluid interface representation, balanced-force continuum-surface-force surface tension formulation and height-function curvature estimation, have allowed us to carry out accurate simulations near the separator plate. The inclusion of the separator plate in the analysis have been shown to have a capital importance on the instabilities generated just after it. The influence of some operational parameters like the momentum ratio, the gas and liquid Reynolds numbers based on the thickness of the boundary layer, the density and viscosity ratios or the thickness and angle of the separator plate are investigated. The analysis of these phenomena is aimed at shedding some new insight into the physical mechanisms controlling atomization processes and to provide better basis for future theoretical analysis.

  3. Modelling evapotranspiration during precipitation deficits: identifying critical processes in a land surface model

    NASA Astrophysics Data System (ADS)

    Ukkola, Anna M.; Pitman, Andy J.; Decker, Mark; De Kauwe, Martin G.; Abramowitz, Gab; Kala, Jatin; Wang, Ying-Ping

    2016-06-01

    Surface fluxes from land surface models (LSMs) have traditionally been evaluated against monthly, seasonal or annual mean states. The limited ability of LSMs to reproduce observed evaporative fluxes under water-stressed conditions has been previously noted, but very few studies have systematically evaluated these models during rainfall deficits. We evaluated latent heat fluxes simulated by the Community Atmosphere Biosphere Land Exchange (CABLE) LSM across 20 flux tower sites at sub-annual to inter-annual timescales, in particular focusing on model performance during seasonal-scale rainfall deficits. The importance of key model processes in capturing the latent heat flux was explored by employing alternative representations of hydrology, leaf area index, soil properties and stomatal conductance. We found that the representation of hydrological processes was critical for capturing observed declines in latent heat during rainfall deficits. By contrast, the effects of soil properties, LAI and stomatal conductance were highly site-specific. Whilst the standard model performs reasonably well at annual scales as measured by common metrics, it grossly underestimates latent heat during rainfall deficits. A new version of CABLE, with a more physically consistent representation of hydrology, captures the variation in the latent heat flux during seasonal-scale rainfall deficits better than earlier versions, but remaining biases point to future research needs. Our results highlight the importance of evaluating LSMs under water-stressed conditions and across multiple plant functional types and climate regimes.

  4. A Robust Multi-Scale Modeling System for the Study of Cloud and Precipitation Processes

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo

    2012-01-01

    During the past decade, numerical weather and global non-hydrostatic models have started using more complex microphysical schemes originally developed for high resolution cloud resolving models (CRMs) with 1-2 km or less horizontal resolutions. These microphysical schemes affect the dynamic through the release of latent heat (buoyancy loading and pressure gradient) the radiation through the cloud coverage (vertical distribution of cloud species), and surface processes through rainfall (both amount and intensity). Recently, several major improvements of ice microphysical processes (or schemes) have been developed for cloud-resolving model (Goddard Cumulus Ensemble, GCE, model) and regional scale (Weather Research and Forecast, WRF) model. These improvements include an improved 3-ICE (cloud ice, snow and graupel) scheme (Lang et al. 2010); a 4-ICE (cloud ice, snow, graupel and hail) scheme and a spectral bin microphysics scheme and two different two-moment microphysics schemes. The performance of these schemes has been evaluated by using observational data from TRMM and other major field campaigns. In this talk, we will present the high-resolution (1 km) GeE and WRF model simulations and compared the simulated model results with observation from recent field campaigns [i.e., midlatitude continental spring season (MC3E; 2010), high latitude cold-season (C3VP, 2007; GCPEx, 2012), and tropical oceanic (TWP-ICE, 2006)].

  5. Modelling evapotranspiration during precipitation deficits: Identifying critical processes in a land surface model

    DOE PAGES

    Ukkola, Anna M.; Pitman, Andy J.; Decker, Mark; De Kauwe, Martin G.; Abramowitz, Gab; Kala, Jatin; Wang, Ying -Ping

    2016-06-21

    Surface fluxes from land surface models (LSMs) have traditionally been evaluated against monthly, seasonal or annual mean states. The limited ability of LSMs to reproduce observed evaporative fluxes under water-stressed conditions has been previously noted, but very few studies have systematically evaluated these models during rainfall deficits. We evaluated latent heat fluxes simulated by the Community Atmosphere Biosphere Land Exchange (CABLE) LSM across 20 flux tower sites at sub-annual to inter-annual timescales, in particular focusing on model performance during seasonal-scale rainfall deficits. The importance of key model processes in capturing the latent heat flux was explored by employing alternative representations of hydrology, leafmore » area index, soil properties and stomatal conductance. We found that the representation of hydrological processes was critical for capturing observed declines in latent heat during rainfall deficits. By contrast, the effects of soil properties, LAI and stomatal conductance were highly site-specific. Whilst the standard model performs reasonably well at annual scales as measured by common metrics, it grossly underestimates latent heat during rainfall deficits. A new version of CABLE, with a more physically consistent representation of hydrology, captures the variation in the latent heat flux during seasonal-scale rainfall deficits better than earlier versions, but remaining biases point to future research needs. Lastly, our results highlight the importance of evaluating LSMs under water-stressed conditions and across multiple plant functional types and climate regimes.« less

  6. Modelling evapotranspiration during precipitation deficits: identifying critical processes in a land surface model

    NASA Astrophysics Data System (ADS)

    Ukkola, A.; Pitman, A.; Decker, M. R.; De Kauwe, M. G.; Abramowitz, G.; Wang, Y.; Kala, J.

    2015-12-01

    Surface fluxes from land surface models (LSM) have traditionally been evaluated against monthly, seasonal or annual mean states. Previous studies have noted the limited ability of LSMs to reproduce observed evaporative fluxes under water-stressed conditions but very few studies have systematically evaluated LSMs during rainfall deficits. We investigate the performance of the Community Atmosphere Biosphere Land Exchange (CABLE) LSM in simulating latent heat fluxes in offline mode. CABLE is evaluated against eddy covariance measurements of latent heat flux across 20 flux tower sites at sub-annual to inter-annual time scales, with a focus on model performance during seasonal-scale rainfall deficits. The importance of key model processes in capturing the latent heat flux is explored by employing alternative representations of hydrology, soil properties, leaf area index and stomatal conductance. We demonstrate the critical role of hydrological processes for capturing observed declines in latent heat. The effects of soil, LAI and stomatal conductance are shown to be highly site-specific. The default CABLE performs reasonably well at annual scales despite grossly underestimating latent heat during rainfall deficits, highlighting the importance for evaluating models explicitly under water-stressed conditions across multiple vegetation and climate regimes. A new version of CABLE, with a more physically consistent representation of hydrology, captures the variation in the latent heat flux during seasonal-scale rainfall deficits better than earlier versions but remaining deficiencies point to future research needs.

  7. Modelling evapotranspiration during precipitation deficits: identifying critical processes in a land surface model

    NASA Astrophysics Data System (ADS)

    Ukkola, A. M.; Pitman, A. J.; Decker, M.; De Kauwe, M. G.; Abramowitz, G.; Kala, J.; Wang, Y.-P.

    2015-10-01

    Surface fluxes from land surface models (LSM) have traditionally been evaluated against monthly, seasonal or annual mean states. The limited ability of LSMs to reproduce observed evaporative fluxes under water-stressed conditions has been previously noted, but very few studies have systematically evaluated these models during rainfall deficits. We evaluated latent heat flux simulated by the Community Atmosphere Biosphere Land Exchange (CABLE) LSM across 20 flux tower sites at sub-annual to inter-annual time scales, in particular focusing on model performance during seasonal-scale rainfall deficits. The importance of key model processes in capturing the latent heat flux are explored by employing alternative representations of hydrology, leaf area index, soil properties and stomatal conductance. We found that the representation of hydrological processes was critical for capturing observed declines in latent heat during rainfall deficits. By contrast, the effects of soil properties, LAI and stomatal conductance are shown to be highly site-specific. Whilst the standard model performs reasonably well at annual scales as measured by common metrics, it grossly underestimates latent heat during rainfall deficits. A new version of CABLE, with a more physically consistent representation of hydrology, captures the variation in the latent heat flux during seasonal-scale rainfall deficits better than earlier versions but remaining biases point to future research needs. Our results highlight the importance of evaluating LSMs under water-stressed conditions and across multiple plant functional types and climate regimes.

  8. A calcium oxide sorbent process for bulk separation of carbon dioxide

    SciTech Connect

    Silaban, A.; Narcida, M.; Harrison, D.P.

    1992-02-01

    The expected commercialization of coal gasification technology in the US and world-wide will create a need for advanced gas purification and separation processes capable of operating at higher temperatures and in more hostile environments than is common today. For example, a high-temperature, high-pressure process capable of separating CO{sub 2} from coal-derived gas may find application in purifying synthesis gas for H{sub 2}, NH{sub 3}, or CH{sub 3}OH production. High temperature CO{sub 2} removal has the potential for significantly improving the operating efficiency of integrated gasification-molten carbonate fuel cells for electric power generation. This study proved the technical feasibility of a CO{sub 2}-separation process based upon the regenerable noncatalytic gas-solid reaction between CaO and CO{sub 2} to form CACO{sub 3}. Such a process operating at 650{degree}C and 15 atm with 15% CO{sub 2} in the coal gas has the potential for removing in excess of 99% of the CO{sub 2} fed. Selection of a sorbent precursor which, upon calcination, produces high-porosity CaO is important for achieving rapid and complete reaction. The addition of magnesium to the sorbent appears to improve the multicycle durability at a cost of reduced CO{sub 2} capacity per unit mass of sorbent. Reaction conditions, principally calcination and carbonation temperatures, are important factors in multicycle durability. Reaction pressure and CO{sub 2} concentration are important in so far as the initial rapid reaction rate is concerned, but are relatively unimportant in terms of sorbent capacity and durability. Indirect evidence for the simultaneous occurrence of the shift reaction and CO{sub 2}-removal reaction creates the possibility of a direct one-step process for the production of hydrogen from coal-derived gas.

  9. An Improved Bulk Microphysical Scheme for Studying Precipitation Processes: Comparisons with Other Schemes

    NASA Technical Reports Server (NTRS)

    Tao, W. K.; Shi, J. J.; Lang, S.; Chen, S.; Hong, S-Y.; Peters-Lidard, C.

    2007-01-01

    Cloud microphysical processes play an important role in non-hydrostatic high-resolution simulations. Over the past decade both research and operational numerical weather prediction models have started using more complex cloud microphysical schemes that were originally developed for high-resolution cloud-resolving models. An improved bulk microphysical parameterization (adopted from the Goddard microphysics schemes) has recently implemented into the Weather Research and Forecasting (WRF) model. This bulk microphysical scheme has three different options --- 2ICE (cloud ice & snow), 3ICE-graupel (cloud ice, snow & graupel) and 3ICE-hail (cloud ice, snow & hail). High-resolution model simulations are conducted to examine the impact of microphysical schemes on two different weather events (a midlatitude linear convective system and an Atlantic hurricane). In addition, this bulk microphysical parameterization is compared with WIRF's three other bulk microphysical schemes.

  10. Precipitation of Scale-Forming Species During Processing of High-Level Wastes

    SciTech Connect

    Mattigod, Shas V.; Hobbs, David T.; Parker, Kent E.; McCready, David E.

    2004-03-29

    High-level wastes from fuel-reprocessing operations are being evaporated at the DOE Savannah River Site to concentrate the liquids to about 30 to 40% of their original volume before they are discharged into a holding tank. Recently, the operation of one of the evaporators became progressively more difficult due to more frequent buildup of limited solubility aluminosilicate compounds resulting in the shutdown of the evaporator. Our research objectives were to identify and characterize the chemistry and microstructure of these scale-forming species and to determine the kinetics of formation and transformation of these solids under evaporator conditions. The data we obtained from these tests showed that hydroxide concentration and process temperature are the key factors that control the rate of formation and transformation of the scale forming solids such as zeolite A, sodalite and cancrinite.

  11. The Impact of Aerosols on Cloud and Precipitation Processes: Cloud-Resolving Model Simulations

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo; Li, X.; Khain, A.; Simpson, S.

    2005-01-01

    Cloud microphysics are inevitable affected by the smoke particle (CCN, cloud condensation nuclei) size distributions below the clouds, Therefore, size distributions parameterized as spectral bin microphysics are needed to explicitly study the effect of atmospheric aerosol concentration on cloud development, rainfall production, and rainfall rates for convective clouds. Recently, a detailed spectral-bin microphysical scheme was implemented into the the Goddard Cumulus Ensemble (GCE) model. The formulation for the explicit spectral-bim microphysical processes is based on solving stochastic kinetic equations for the size distribution functions of water droplets (i.e., cloud droplets and raindrops), and several types of ice particles [i.e., pristine ice crystals (columnar and plate-like), snow (dendrites and aggregates), graupel and frozen drops/hail]. Each type is described by a special size distribution function containing many categories (i.e., 33 bins). Atmospheric aerosols are also described using number density size-distribution functions.

  12. Coal-gold agglomeration: an alternative separation process in gold recovery

    SciTech Connect

    Akcil, A.; Wu, X.Q.; Aksay, E.K.

    2009-07-01

    Considering the increasing environmental concerns and the potential for small gold deposits to be exploited in the future, the uses of environmentally friendly processes are essential. Recent developments point to the potential for greatly increased plant performance through a separation process that combines the cyanide and flotation processes. In addition, this kind of alternative treatment processes to the traditional gold recovery processes may reduce the environmental risks of present small-scale gold mining. Gold recovery processes that applied to different types of gold bearing ore deposits show that the type of deposits plays an important role for the selection of mineral processing technologies in the production of gold and other precious metals. In the last 25 years, different alternative processes have been investigated on gold deposits located in areas where environmental issues are a great concern. In 1988, gold particles were first recovered by successful pilot trial of coal-gold agglomeration (CGA) process in Australia. The current paper reviews the importance of CGA in the production of gold ore and identifies areas for further development work.

  13. Design and testing of small scale fish meat bone separator useful for fish processing.

    PubMed

    Ali Muhammed, M; Manjunatha, N; Murthy, K Venkatesh; Bhaskar, N

    2015-06-01

    The present study relates to the food processing machinery and, more specifically machine for producing boneless comminuted meat from raw fish fillet. This machine is of belt and drum type meat bone separator designed for small scale fish processing in a continuous mode. The basic principal involved in this machine is compression force. The electric geared motor consists of 1HP and the conveyor belt has a linear velocity of 19 to 22 m min(-1), which was sufficient to debone the fish effectively. During the meat bone separation trials an efficiency up to 75 % on dressed fish weight basis was observed and with a capacity to separate 70 kg h(-1) of meat from fish at the machine speed of 25 rpm. During the trials, it was demonstrated that there was no significant change in the proximate composition of comminuted fish meat when compared to unprocessed fish meat. This design has a greater emphasis on hygiene, provision for cleaning-in-place (CIP) and gives cost effective need and reliability for small scale industries to produce fish meat in turn used for their value added products.

  14. Design and testing of small scale fish meat bone separator useful for fish processing.

    PubMed

    Ali Muhammed, M; Manjunatha, N; Murthy, K Venkatesh; Bhaskar, N

    2015-06-01

    The present study relates to the food processing machinery and, more specifically machine for producing boneless comminuted meat from raw fish fillet. This machine is of belt and drum type meat bone separator designed for small scale fish processing in a continuous mode. The basic principal involved in this machine is compression force. The electric geared motor consists of 1HP and the conveyor belt has a linear velocity of 19 to 22 m min(-1), which was sufficient to debone the fish effectively. During the meat bone separation trials an efficiency up to 75 % on dressed fish weight basis was observed and with a capacity to separate 70 kg h(-1) of meat from fish at the machine speed of 25 rpm. During the trials, it was demonstrated that there was no significant change in the proximate composition of comminuted fish meat when compared to unprocessed fish meat. This design has a greater emphasis on hygiene, provision for cleaning-in-place (CIP) and gives cost effective need and reliability for small scale industries to produce fish meat in turn used for their value added products. PMID:26028734

  15. Process and apparatus for separation of components of a gas stream

    DOEpatents

    Bryan, Charles R.; Torczynski, John R.; Brady, Patrick V.; Gallis, Michail; Brooks, Carlton F.

    2014-06-17

    A process and apparatus for separating a gas mixture comprising providing a slot in a gas separation channel (conceptualized as a laterally elongated Clusius-Dickel column), having a length through which a net cross-flow of the gas mixture may be established; applying a higher temperature to one side of the channel and a lower temperature on an opposite side of the channel thereby causing thermal-diffusion and buoyant-convection flow to occur in the slot; and establishing a net cross-flow of a gas mixture comprising at least one higher density gas component and at least one lower density gas component along the length of the slot, wherein the cross-flow causes, in combination with the convection flow, a spiraling flow in the slot; and wherein the spiral flow causes an increasing amount of separation of the higher density gas from the lower density gas along the length of the channel. The process may use one or more slots and/or channels.

  16. Process and apparatus for separation of components of a gas stream

    DOEpatents

    Bryan, Charles R; Torczynski, John R; Brady, Patrick V; Gallis, Michail; Brooks, Carlton F

    2013-09-17

    A process and apparatus for separating a gas mixture comprising providing a slot in a gas separation channel (conceptualized as a laterally elongated Clusius-Dickel column), having a length through which a net cross-flow of the gas mixture may be established; applying a higher temperature to one side of the channel and a lower temperature on an opposite side of the channel thereby causing thermal-diffusion and buoyant-convection flow to occur in the slot; and establishing a net cross-flow of a gas mixture comprising at least one higher density gas component and at least one lower density gas component along the length of the slot, wherein the cross-flow causes, in combination with the convection flow, a spiraling flow in the slot; and wherein the spiral flow causes an increasing amount of separation of the higher density gas from the lower density gas along the length of the channel. The process may use one or more slots and/or channels.

  17. Process and apparatus for separation of components of a gas stream

    DOEpatents

    Bryan, Charles R; Torczynski, John R; Brady, Patrick V; Gallis, Michail; Brooks, Carlton F

    2013-11-19

    A process and apparatus for separating a gas mixture comprising providing a slot in a gas separation channel (conceptualized as a laterally elongated Clusius-Dickel column), having a length through which a net cross-flow of the gas mixture may be established; applying a higher temperature to one side of the channel and a lower temperature on an opposite side of the channel thereby causing thermal-diffusion and buoyant-convection flow to occur in the slot; and establishing a net cross-flow of a gas mixture comprising at least one higher density gas component and at least one lower density gas component along the length of the slot, wherein the cross-flow causes, in combination with the convection flow, a spiraling flow in the slot; and wherein the spiral flow causes an increasing amount of separation of the higher density gas from the lower density gas along the length of the channel. The process may use one or more slots and/or channels.

  18. Reconstructing climate processes driving variability in precipitation sources from mid to late Holocene speleothem δ18O records from the Southwest US

    NASA Astrophysics Data System (ADS)

    Wong, C. I.; Nusbaumer, J. M.; Banner, J.

    2015-12-01

    Independent co-variation of speleothem δ18O values and other moisture-sensitive speleothem proxies (e.g., growth rate, trace element concentrations) in recently published Holocene stalagmite records from Texas and New Mexico suggest a decoupling between precipitation amounts and precipitation sources over the southwest US. There is, however, limited understanding of the relation between precipitation sources and precipitation amounts and the climate processes governing variability in the region's precipitation sources. To address this, we use source water tags to track precipitation derived from Pacific and Atlantic Oceans during a simulation of modern (1975-2013) climate. We find distinct patterns in the spatial distribution of the fraction of Pacific-derived winter precipitation are associated with unique atmospheric states. High pressure ridging reflected by 500 hPa geopotential heights result in weaker zonal winds and stronger northerly winds over the western US. Under these conditions, Pacific-derived moisture propagates further to the east, and Atlantic-derived moisture is suppressed over southern US. Conversely, 500 hPa geopotential heights that are latitudinally streamline result in strong zonal winds across the entire US. Under these conditions, the fraction of West Pacific-derived precipitation is limited to higher latitudes, and the fraction of far East Pacific- and Atlantic-derived precipitation is enhanced across the Southwest and Southern US, respectively. Further analysis of this data set will assess the teleconnections that link the distinct atmospheric conditions over the US with the state of the ocean and atmosphere over the Pacific and Atlantic Oceans. The results will be applied to reconstructing variability in the climate dynamics governing moisture transport to the southwest US during the mid to late Holocene as reflected by speleothem δ18O records in the region.

  19. Adsorption compared with sulfide precipitation as metal removal processes from acid mine drainage in a constructed wetland

    NASA Astrophysics Data System (ADS)

    Machemer, Steven D.; Wildeman, Thomas R.

    1992-01-01

    Metal removal processes from acid mine drainage were studied in an experimental constructed wetland in the Idaho Springs-Central City mining district of Colorado. The wetland was designed to passively remove heavy metals from the mine drainage flowing from the Big Five Tunnel. Concurrent studies were performed in the field on the waters flowing from the wetland and in the laboratory on the wetland substrate. Both studies suggest that there is competition for organic adsorption sites among Fe, Cu, Zn and Mn. Iron and Cu appear to be more strongly adsorbed than Zn and Mn. The adsorption of metals varies with the fluctuation of pH in the outflow water. Also indicated by field and laboratory studies is the microbial reduction of sulfate with a corresponding increase in the sulfide concentration of the water. As sulfide is generated. Cu and Zn are completely removed. The field results suggest that upon start up of a constructed wetland, the adsorption of dissolved metals onto organic sites in the substrate material will be an important process. Over time, sulfide precipitation becomes the dominant process for metal removal from acid mine drainage.

  20. The Impact of Aerosols on Cloud and Precipitation Processes: Cloud-Resolving Model Simulations

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo; Li, X.; Khain, A.; Simpson, S.

    2004-01-01

    Cloud microphysics are inevitably affected by the smoke particle (CCN, cloud condensation nuclei) size distributions below the clouds. Therefore, size distributions parameterized as spectral bin microphysics are needed to explicitly study the effects of atmospheric aerosol concentration on cloud development, rainfall production, and rainfall rates for convective clouds. Recently, two detailed spectral-bin microphysical schemes were implemented into the Goddard Cumulus Ensemble (GCE) model. The formulation for the explicit spectral-bin microphysical processes is based on solving stochastic kinetic equations for the size distribution functions of water droplets (i.e., cloud droplets and raindrops), and several types of ice particles (i.e., pristine ice crystals (columnar and plate-like), snow (dendrites and aggregates), graupel and frozen drops/hail). Each type is described by a special size distribution function containing many categories (i.e. 33 bins). Atmospheric aerosols are also described using number density size-distribution functions. A spectral-bin microphysical model is very expensive from a computational point of view and has only been implemented into the 2D version of the GCE at the present time. The model is tested by studying the evolution of deep cloud systems in the west Pacific warm pool region, in the sub-tropics (Florida) and in the mid-latitude using identical thermodynamic conditions but with different concentrations of CCN: a low 'clean' concentration and a high 'dirty' concentration.