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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. Using precipitation by polyamines as an alternative to chromatographic separation in antibody purification processes.

    PubMed

    Ma, Junfen; Hoang, Hai; Myint, Thomas; Peram, Thanmaya; Fahrner, Robert; Chou, Judy H

    2010-03-15

    Polyamine precipitation conditions for removing host cell protein impurities from the cell culture fluid containing monoclonal antibody were studied. We examined the impact of polyamine concentration, size, structure, cell culture fluid pH and ionic strength. A 96-well microtiter plate based high throughput screening method was developed and used for evaluating different polyamines. Polyallylamine, polyvinylamine, branched polyethyleneimine and poly(dimethylamine-co-epichlorohydrin-ethylenediamine) were identified as efficient precipitants in removing host cell protein impurities. Leveraging from the screening results, we incorporated a polyamine precipitation step into a monoclonal antibody purification process to replace the Protein A chromatography step. The optimization of the overall purification process was performed by taking the mechanisms of both precipitation and chromatographic separation into account. The precipitation-containing process removed a similar amount of process-related impurities, including host cell proteins, DNA, insulin and gentamicin and maintained similar product quality in respect of size and charge variants to chromatography based purification. Overall recovery yield was comparable to the typical Protein A affinity chromatography based antibody purification process.

  3. 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.

  4. 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.

  5. Separation of particles precipitated from (U,RE){sub 3}O{sub 8} powder oxidation by dry process

    SciTech Connect

    Lee Jae Won; Lee Jung Won; Yang Myung Seung; Song Kee Chan; Park Geun Il

    2007-07-01

    The phase separation characteristics of RE elements from SIMFUEL (simulated spent fuel) was investigated by a high temperature oxidation at 1174{approx}1673 K using a fuel powder of (U,RE){sub 3}O{sub 8} in a single RE element system. A typical oxidation and reduction treatment followed by a dry milling process was introduced and investigated for a separation of the precipitated RE-rich (U{sub 1-y}RE{sub y})O{sub 2+z} particles and RE-poor U{sub 3}O{sub 8} particles formed by a high temperature oxidation. The XRD and SEM results indicate that an increase of the oxidation temperature increases the amount of the (U{sub 1-y}RE{sub y})O{sub 2+z} phase, while decreasing that of the RE-poor U{sub 3}O{sub 8}-type phase. Since the solubility of RE in the U{sub 3}O{sub 8}-type phase was almost constant regardless of the oxidation temperature, the decrease of the RE concentration in the RE-rich (U{sub 1-y}RE{sub y})O{sub 2+z} phase with an increasing oxidation temperature seems to be due to a diffusion of the U ion from the RE-poor U{sub 3}O{sub 8}-type phase to the RE-rich (U{sub 1-y}RE{sub y})O{sub 2+z} phase. The RE-rich (U{sub 1-y}RE{sub y})O{sub 2+z} particle precipitated from the RE-poor U{sub 3}O{sub 8} particle is mostly separated by a reduction and oxidation treatment at a typical temperature of the powdering process of uranium dioxide and completely separated by a dry milling. (authors)

  6. 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.

  7. 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.

  8. 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.

  9. Near infrared spectroscopy combined with multivariate analysis for monitoring the ethanol precipitation process of fraction I + II + III supernatant in human albumin separation

    NASA Astrophysics Data System (ADS)

    Li, Can; Wang, Fei; Zang, Lixuan; Zang, Hengchang; Alcalà, Manel; Nie, Lei; Wang, Mingyu; Li, Lian

    2017-03-01

    Nowadays, as a powerful process analytical tool, near infrared spectroscopy (NIRS) has been widely applied in process monitoring. In present work, NIRS combined with multivariate analysis was used to monitor the ethanol precipitation process of fraction I + II + III (FI + II + III) supernatant in human albumin (HA) separation to achieve qualitative and quantitative monitoring at the same time and assure the product's quality. First, a qualitative model was established by using principal component analysis (PCA) with 6 of 8 normal batches samples, and evaluated by the remaining 2 normal batches and 3 abnormal batches. The results showed that the first principal component (PC1) score chart could be successfully used for fault detection and diagnosis. Then, two quantitative models were built with 6 of 8 normal batches to determine the content of the total protein (TP) and HA separately by using partial least squares regression (PLS-R) strategy, and the models were validated by 2 remaining normal batches. The determination coefficient of validation (Rp2), root mean square error of cross validation (RMSECV), root mean square error of prediction (RMSEP) and ratio of performance deviation (RPD) were 0.975, 0.501 g/L, 0.465 g/L and 5.57 for TP, and 0.969, 0.530 g/L, 0.341 g/L and 5.47 for HA, respectively. The results showed that the established models could give a rapid and accurate measurement of the content of TP and HA. The results of this study indicated that NIRS is an effective tool and could be successfully used for qualitative and quantitative monitoring the ethanol precipitation process of FI + II + III supernatant simultaneously. This research has significant reference value for assuring the quality and improving the recovery ratio of HA in industrialization scale by using NIRS.

  10. Near infrared spectroscopy combined with multivariate analysis for monitoring the ethanol precipitation process of fraction I+II+III supernatant in human albumin separation.

    PubMed

    Li, Can; Wang, Fei; Zang, Lixuan; Zang, Hengchang; Alcalà, Manel; Nie, Lei; Wang, Mingyu; Li, Lian

    2017-03-15

    Nowadays, as a powerful process analytical tool, near infrared spectroscopy (NIRS) has been widely applied in process monitoring. In present work, NIRS combined with multivariate analysis was used to monitor the ethanol precipitation process of fraction I+II+III (FI+II+III) supernatant in human albumin (HA) separation to achieve qualitative and quantitative monitoring at the same time and assure the product's quality. First, a qualitative model was established by using principal component analysis (PCA) with 6 of 8 normal batches samples, and evaluated by the remaining 2 normal batches and 3 abnormal batches. The results showed that the first principal component (PC1) score chart could be successfully used for fault detection and diagnosis. Then, two quantitative models were built with 6 of 8 normal batches to determine the content of the total protein (TP) and HA separately by using partial least squares regression (PLS-R) strategy, and the models were validated by 2 remaining normal batches. The determination coefficient of validation (Rp(2)), root mean square error of cross validation (RMSECV), root mean square error of prediction (RMSEP) and ratio of performance deviation (RPD) were 0.975, 0.501g/L, 0.465g/L and 5.57 for TP, and 0.969, 0.530g/L, 0.341g/L and 5.47 for HA, respectively. The results showed that the established models could give a rapid and accurate measurement of the content of TP and HA. The results of this study indicated that NIRS is an effective tool and could be successfully used for qualitative and quantitative monitoring the ethanol precipitation process of FI+II+III supernatant simultaneously. This research has significant reference value for assuring the quality and improving the recovery ratio of HA in industrialization scale by using NIRS.

  11. 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.

  12. 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.

  13. URANIUM SEPARATION PROCESS

    DOEpatents

    McVey, W.H.; Reas, W.H.

    1959-03-10

    The separation of uranium from an aqueous solution containing a water soluble uranyl salt is described. The process involves adding an alkali thiocyanate to the aqueous solution, contacting the resulting solution with methyl isobutyl ketons and separating the resulting aqueous and organic phase. The uranium is extracted in the organic phase as UO/sub 2/(SCN)/sub/.

  14. 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.

  15. 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.

  16. Process for phase separation

    DOEpatents

    Comolli, Alfred G.

    1979-01-01

    This invention provides a continuous process for separating a gaseous phase from a hydrocarbon liquid containing carbonaceous particulates and gases. The liquid is fed to a cylindrical separator, with the gaseous phase being removed therefrom as an overhead product, whereas the hydrocarbon liquid and the particulates are withdrawn as a bottoms product. By feeding the liquid tangentially to the separator and maintaining a particulate-liquid slurry downward velocity of from about 0.01 to about 0.25 fps in the separator, a total solids weight percent in the slurry of from about 0.1 to about 30%, a slurry temperature of from about 550.degree. to about 900.degree. F., a slurry residence time in the separator of from about 30 to about 360 seconds, and a length/diameter ratio for the separator of from about 20/1 to about 50/1, so that the characterization factor, .alpha., defined as ##STR1## DOES NOT EXCEED ABOUT 48 (.degree.R sec.sup.2)/ft, the deposit of carbonaceous materials on the interior surface of the separator may be substantially eliminated.

  17. 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.

  18. 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.

  19. Cyclic membrane separation process

    DOEpatents

    Bowser, John

    2004-04-13

    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 one 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 other part, the membrane is inoperative while gas pressure rises in the ullage. Ambient air is charged to the membrane separation unit during the latter part of the cycle.

  20. 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.

  1. 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.

  2. 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.

  3. Selective Separation of Similar Metals in Chloride Solution by Sulfide Precipitation Under Controlled Potential

    NASA Astrophysics Data System (ADS)

    Liu, Weifeng; Sun, Baiqi; Zhang, Duchao; Chen, Lin; Yang, Tianzu

    2017-08-01

    A new process of sulfide precipitation under controlled potential was proposed to separate selectively similar metals in a Bis(2-ethylhexyl) phosphoric acid (P204) stripping solution of the Co extraction system. Theoretical calculations revealed that Cu2+, Co2+, Zn2+, and Mn2+ could be separated by fractional precipitation with sulfide by controlling the solution potential and pH value simultaneously. The results demonstrated a Cu precipitation ratio reaching 99.9% during sulfide precipitation of Cu at the potential of 330 mV; the Cu/Co mass ratio in the Cu precipitate was 224. The Co precipitation ratio in the xanthate precipitation of Co, at a potential of 170 mV, was 99.9%, and the Co/Zn mass ratio in the Co precipitate was 28.0. The Zn precipitation ratio reached 99.9% for sulfide precipitation of Zn at the potential of 30 mV, and the Zn/Mn mass ratio in the Zn precipitate was 1.41. The Mn precipitation ratio reached 99.9% after neutralization.

  4. Precipitation phase separation schemes in the Naqu River basin, eastern Tibetan plateau

    NASA Astrophysics Data System (ADS)

    Liu, Shaohua; Yan, Denghua; Qin, Tianling; Weng, Baisha; Lu, Yajing; Dong, Guoqiang; Gong, Boya

    2016-11-01

    Precipitation phase has a profound influence on the hydrological processes in the Naqu River basin, eastern Tibetan plateau. However, there are only six meteorological stations with precipitation phase (rainfall/snowfall/sleet) before 1979 within and around the basin. In order to separate snowfall from precipitation, a new separation scheme with S-shaped curve of snowfall proportion as an exponential function of daily mean temperature was developed. The determinations of critical temperatures in the single/two temperature threshold (STT/TTT2) methods were explored accordingly, and the temperature corresponding to the 50 % snowfall proportion (SP50 temperature) is an efficiently critical temperature for the STT, and two critical temperatures in TTT2 can be determined based on the exponential function and SP50 temperature. Then, different separation schemes were evaluated in separating snowfall from precipitation in the Naqu River basin. The results show that the S-shaped curve methods outperform other separation schemes. Although the STT and TTT2 slightly underestimate and overestimate the snowfall when the temperature is higher and colder than SP50 temperature respectively, the monthly and annual separation snowfalls are generally consistent with the observed snowfalls. On the whole, S-shaped curve methods, STT, and TTT2 perform well in separating snowfall from precipitation with the Pearson correlation coefficient of annual separation snowfall above 0.8 and provide possible approaches to separate the snowfall from precipitation for hydrological modelling.

  5. Wax separation process

    SciTech Connect

    Broadhurst, T.E.

    1980-06-03

    Particles of solid wax are separated from a slurry comprising said wax particles and a hydrocarbon oil by filtering the slurry through a cloth filter medium. It has been found that using, as the filter medium, a needled-felt cloth fabricated from fibers fusible by means of an open flame and having a singed surface on which the wax is collected results in an unexpected reduction in filter cloth blinding thereby yielding up to 30% increased throughput through the filter cloth and greatly reducing the frequency of washing the filter cloth. The cloth is further characterized in that it has a permeability to air in excess of about 3 cubic feet per minute per square foot of cloth surface at a differential pressure of 0.5 inches of water, a root mean square surface roughness in excess of 500 rms microinches and a fouling factor in excess of about 75%. This improved process has been found to be particularly useful for separating wax particles from a dewaxed lube oil slurry.

  6. Radiation effects on separations materials and processes

    SciTech Connect

    Bibler, N.E.

    1991-12-31

    This paper briefly summarizes published information on the effects of ionizing radiation on separation processes and materials. Special emphasis is given those processes, solvent extraction, ion exchange, and precipitation, that may have application in removing radioactivity from nuclear waste solutions. The separation and eventual isolation of any radionuclide requires a knowledge of the effect of radiation on the separations process itself and on the materials used in the process. The higher the radiation dose rate, i.e. the more concentrated the radionuclides being processed, the more important is this knowledge. In some cases, such as the separation of intense alpha emitters or the treatment of concentrated solutions of fission products, consideration of the effects of the radiation is a critical factor in the design of the separations materials and in the implementation of the process.

  7. Radiation effects on separations materials and processes

    SciTech Connect

    Bibler, N.E.

    1991-01-01

    This paper briefly summarizes published information on the effects of ionizing radiation on separation processes and materials. Special emphasis is given those processes, solvent extraction, ion exchange, and precipitation, that may have application in removing radioactivity from nuclear waste solutions. The separation and eventual isolation of any radionuclide requires a knowledge of the effect of radiation on the separations process itself and on the materials used in the process. The higher the radiation dose rate, i.e. the more concentrated the radionuclides being processed, the more important is this knowledge. In some cases, such as the separation of intense alpha emitters or the treatment of concentrated solutions of fission products, consideration of the effects of the radiation is a critical factor in the design of the separations materials and in the implementation of the process.

  8. 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.

  9. 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.

  10. Identifying Anomality in Precipitation Processes

    NASA Astrophysics Data System (ADS)

    Jiang, P.; Zhang, Y.

    2014-12-01

    Safety, risk and economic analyses of engineering constructions such as storm sewer, street and urban drainage, and channel design are sensitive to precipitation storm properties. Whether the precipitation storm properties exhibit normal or anomalous characteristics remains obscure. In this study, we will decompose a precipitation time series as sequences of average storm intensity, storm duration and interstorm period to examine whether these sequences could be treated as a realization of a continuous time random walk with both "waiting times" (interstorm period) and "jump sizes" (average storm intensity and storm duration). Starting from this viewpoint, we will analyze the statistics of storm duration, interstorm period, and average storm intensity in four regions in southwestern United States. We will examine whether the probability distribution is temporal and spatial dependent. Finally, we will use fractional engine to capture the randomness in precipitation storms.

  11. 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.

  12. Can the D2007-80 with asphaltene precipitation (SARA) separation, size exclusion chromatography with element specific detection, and hydrogen distribution by NMR help at all in predicting residuum processability

    SciTech Connect

    Reynolds, J.G. )

    1989-04-01

    In refinery processing there has been need for quick simple, cost-effective methods to evaluate the effects of a process on a feed, and to evaluate specific feeds for processability. Correlations between various process parameters and product properties have been attempted, but few have been found adequate in heavy oil processing. The problem with finding usable correlations depends on indicating processability, and whether that indicator can be measured in a reasonable way. This indicator depends upon several factors, particularly the desired process aim (for example, boiling range reduction or heteroatom removal). Equally important is how the indicator is related to some measurable feed or process property. Such properties are preferable if measured easily through direct feed analysis. But often times, these properties are measured through actual process products derived from a test batch, or pilot plant performance. The impetus of this paper is not to present new data in the field of process parameter evaluation nor to do an extensive review of the literature, but to select parts of the literature and assess whether the D 2007-80 with asphaltene precipitation separation, size exclusion chromatography with element specific detection, or hydrogen distribution by NMR can predict residuum processability.

  13. 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)

  14. 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.

  15. Separation process using microchannel technology

    DOEpatents

    Tonkovich, Anna Lee [Dublin, OH; Perry, Steven T [Galloway, OH; Arora, Ravi [Dublin, OH; Qiu, Dongming [Bothell, WA; Lamont, Michael Jay [Hilliard, OH; Burwell, Deanna [Cleveland Heights, OH; Dritz, Terence Andrew [Worthington, OH; McDaniel, Jeffrey S [Columbus, OH; Rogers, Jr; William, A [Marysville, OH; Silva, Laura J [Dublin, OH; Weidert, Daniel J [Lewis Center, OH; Simmons, Wayne W [Dublin, OH; Chadwell, G Bradley [Reynoldsburg, OH

    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.

  16. Magnetic Separation Using HTS Bulk Magnet for Cs-Bearing Fe precipitates

    NASA Astrophysics Data System (ADS)

    Oka, T.; Ichiju, K.; Sasaki, S.; Ogawa, J.; Fukui, S.; Sato, T.; Ooizumi, M.; Yokoyama, K.; Aoki, S.; Ohnishi, N.

    2017-09-01

    A peculiar magnetic separation technique has been examined in order to remove the Cs-bearing Fe precipitates formed of the waste ash from the withdrawn incinerator furnaces in Fukushima. The separation system was constructed in combination with high temperature superconducting bulk magnets which generates the intensive magnetic field over 2 T, which was activated by the pulsed field magnetization process. The separation experiment has been operated with use of the newly-built alternating channel type magnetic separating device, which followed the high-gradient magnetic separation technique. The magnetic stainless steel filters installed in the water channels are magnetized by the applied magnetic fields, and are capable of attracting the precipitates bearing the Fe compound and thin Cs contamination. The experimental results clearly exhibited the positive feasibility of HTS bulk magnets.

  17. 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.

  18. 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.

  19. Global Precipitation Measurement (GPM) Mission: NASA Precipitation Processing System (PPS)

    NASA Technical Reports Server (NTRS)

    Stocker, Erich Franz

    2008-01-01

    NASA is contributing the precipitation measurement data system PPS to support the GPM mission. PPS will distribute all GPM data products including NASA s GMI data products freely and quickly. PPS is implementing no system mechanisms for restricting access to GPM data. PPS is implementing no system mechanisms for charging for GPM data products. PPS will provide a number of geographical and parameter subsetting features available to its users. The first implementation of PPS (called PPS--) will assume processing of TRMM data effective 1 June 2008. TRMM realtime data will be available via PPS- to all users requesting access

  20. 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.

  1. 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.

  2. Flocculation, coagulation, and precipitation of manure affecting three separation techniques.

    PubMed

    Hjorth, Maibritt; Christensen, Morten Lykkegaard; Christensen, Peter Vittrup

    2008-12-01

    The effects of polymer flocculation before manure separation were investigated, through testing both a linear and a branched polymer. Centrifugation removed 60% of phosphorus from raw manure (control), whereas raw manure clogged the filters during gravity drainage and pressure filtration. At optimum flocculation, 95% of phosphorus was removed using any of the three methods. Optimum flocculation was achieved when 2.8meq of polymer charge was added per kg of manure, corresponding to 0.6g/kg of highly charged, branched polymer or 0.85g/kg of less-charged, linear polymer. If 10mmol of ferric chloride was added per kg of manure, 2% more phosphorus was precipitated and removed. The linear polymer formed loose flocs and was superior for reducing turbidity, whereas the branched polymer formed compact flocs that deflocculated at high polymer doses. The branched polymer, however, was best for pressure filtration, as overdosing with the linear polymer resulted in high resistance.

  3. Process for separating bituminous materials

    SciTech Connect

    Roach, J.W.

    1981-07-21

    A process is claimed for separating a solvent from a bituminous material by pressure reduction and steam stripping without carry-over of entrained bituminous material. The fluid-like phase of bituminous material and solvent is reduced in pressure and introduced into a steam stripper. The solvent vaporizes upon pressure reduction and a mist of fine bituminous material particles forms and becomes dispersed in the vaporized solvent. The vaporized solvent and associated mist is separated from the bituminous material in the stripper and is withdrawn from the steam stripper and introduced into a condenser. The solvent and steam from the stripper condense, a substantial portion of the mist of entrained particles solidifies and an emulsion of water and fluid-like bituminous material from the mist forms. The liquid stream is withdrawn from the condenser and introduced into a separator. The liquid stream separates in the separator into an upper fraction of solvent, a middle fraction of emulsion and a lower fraction of water and the solidified particles of bituminous material. The liquid solvent is removed by passage over a weir in the separator and recovered. The emulsion, water and solids can be removed from the base of the separator for disposal.

  4. 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.

  5. 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.

  6. 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.

  7. Charge Generation and Separation Processes

    NASA Astrophysics Data System (ADS)

    Yair, Y.

    2008-06-01

    This paper presents a short overview of our current understanding of the generation of charged particles in different environments and circumstances (e.g. thunderclouds, dust storms, volcanic plumes, rings, and planetary surfaces) and the subsequent spatial separation that leads to the formation of electrical fields. Different mechanisms are involved on various scales, starting from the molecular level, through the single particle (droplet, crystal, solid) and finally the entraining volume (cloud, plume etc.). Encapsulated within a dynamic and turbulent medium, particles need to come into contact and to immediately separate, to be later transported away from each other. In order to explain the observed electrical fields and ensuing lightning or other forms of discharge, these processes need to be extremely effective. The section will briefly review laboratory results and modeling efforts of charge separation and electric field build-up in various planetary settings, and cite the appropriate observations of electrical activity on different planets.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Process for separating bituminous materials

    SciTech Connect

    Harris, S.W.; Roach, J.W.

    1981-06-16

    A process is disclosed for separating a solvent from a bituminous material by pressure reduction and steam stripping without carry-over of entrained bituminous material. A fluid-like phase comprising of bituminous material and solvent is reduced in pressure by passage through a pressure reduction valve to vaporize a portion of the solvent. The reduction in pressure also results in dispersing a mist of fine bituminous material particles in the vaporized solvent. The stream of vaporized solvent, mist and fluid-like bituminous material then is introduced into a static mixer. The static mixer intimately mixes the mist with the fluid-like material and causes the mist to recombine with the fluid-like material from which it was formed. The resulting stream is introduced into a steam stripper to separate the solvent remaining in the bituminous material. The vaporized solvent and steam are withdrawn from the stripper substantially free of entrained bituminous material and condensed. The liquid stream is introduced into a solvent surge vessel having a water draw. The solvent then is recycled in the process.

  14. 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). ).

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

    DOE PAGES

    Garfinkel, David A.; Tucker, Julie D.; Haley, Daniel A.; ...

    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

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

    SciTech Connect

    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 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).

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

    SciTech Connect

    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 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).

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

    PubMed

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

    2013-12-06

    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.

  19. 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.

  20. Treatment processes for source-separated urine.

    PubMed

    Maurer, M; Pronk, W; Larsen, T A

    2006-10-01

    The separate collection and treatment of urine has attracted considerable attention in the engineering community in the last few years and is seen as a viable option for enhancing the flexibility of wastewater treatment systems. This comprehensive review focuses on the status of current urine treatment processes and summarises the properties of collected urine. We distinguish between seven main purposes of urine-treatment processes: hygienisation (storage), volume reduction (evaporation, freeze-thaw, reverse osmosis), stabilisation (acidification, nitrification), P-recovery (struvite formation), N-recovery (ion-exchange, ammonia stripping, isobutylaldehyde-diurea (IBDU) precipitation), nutrient removal (anammox) and handling of micropollutants (electrodialysis, nanofiltration, ozonation). The review shows clearly that a wide range of technical options is available to treat collected urine effectively, but that none of these single options can accomplish all seven purposes. Depending on the overall goal of the treatment process, a specific technical solution or a combination of solutions can be found to meet the requirements. Such combinations are not discussed in this paper unless they are explicitly presented in the literature. Except for 'evaporation' and 'storage', none of the processes described have so far advanced beyond the laboratory stage. Considerable development work remains to be done to optimise urine-processing techniques in order to create marketable products.

  1. 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.

  2. 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.

  3. 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.

  4. Separation of americium, curium, and rare earths from high-level wastes by oxalate precipitation: experiments with synthetic waste solutions

    SciTech Connect

    Forsberg, C.W.

    1980-01-01

    The separation of trivalent actinides and rare earths from other fission products in high-level nuclear wastes by oxalate precipitation followed by ion exchange (OPIX) was experimentally investigated using synthetic wastes and a small-scale, continuous-flow oxalic acid precipitation and solid-liquid separation system. Trivalent actinide and rare earth oxalates are relatively insoluble in 0.5 to 1.0 M HNO/sub 3/ whereas other fission product oxalates are not. The continuous-flow system consisted of one or two stirred-tank reactors in series for crystal growth. Oxalic acid and waste solutions were mixed in the first tank, with the product solid-liquid slurry leaving the second tank. Solid-liquid separation was tested by filters and by a gravity settler. The experiments determined the fraction of rare earths precipitated and separated from synthetic waste streams as a function of number of reactors, system temperature, oxalic acid concentration, liquid residence time in the process, power input to the stirred-tank reactors, and method of solid-liquid separation. The crystalline precipitate was characterized with respect to form, size, and chemical composition. These experiments are only the first step in converting a proposed chemical flowsheet into a process flowsheet suitable for large-scale remote operations at high activity levels.

  5. Interactions between phase separation, mineral precipitation, and permeability variations in saline magmatic-hydrothermal system

    NASA Astrophysics Data System (ADS)

    Weis, P.

    2016-12-01

    Fluid flow through permeable rocks in saline magmatic-hydrothermal systems is influenced by non-linear fluid and rock properties as well as physical and chemical fluid-rock interactions. The same processes are of critical importance to a variety of different disciplines of Earth sciences such as volcanology, geothermal energy, hydrogeology and economic geology, and progress in understanding the relative importance of the interactions between different processes requires multi-method approaches investigating both active and fossil hydrothermal systems. Observations and model results suggest that many of these systems are highly dynamic and have a potential for self-organization, optimizing heat and mass transport by fluids in the upper crust. For example, numerical simulations in combination with oxygen isotopes of vein quartz suggest that ore precipitation in porphyry copper deposits occurs at the hydrological interface between a dynamic plume of ascending magmatic fluids and meteoric water convection, which is controlled by the transition from ductile to brittle rock behavior. With increasing ductile behavior, we infer that locally host rock permeability is reduced and the regional stress state is relaxed, resulting in fluid pressure build-up to near-lithostatic values with continued fluid expulsion, which eventually leads to episodic brittle failure of otherwise nominally ductile rocks. Sharp pressure drops and phase separation at this hydrological front can lead to saturation in solid halite, which is indicated to be a ubiquitous feature in hydrothermal systems associated with upper crustal plutons both by fluid inclusion studies and numerical simulations. Precipitation of solid halite can also lead to permeability reduction and evoke pulsating fluid migration. The presentation will show analytical and numerical results describing the role of non-linear fluid properties, phase separation, salt precipitation, fluid mixing, hydraulic fracturing and the brittle

  6. 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.

  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. 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.

  9. Fabrication of Separator Demonstration Facility process vessel

    SciTech Connect

    Oberst, E.F.

    1985-01-15

    The process vessel system is the central element in the Separator Development Facility (SDF). It houses the two major process components, i.e., the laser-beam folding optics and the separators pods. This major subsystem is the critical-path procurement for the SDF project. Details of the vaious parts of the process vessel are given.

  10. 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.

  11. Concentration and Separation of Active Proteins from Potato Industry Waste Based on Low-Temperature Evaporation and Ethanol Precipitation

    PubMed Central

    Ahokas, Mikko; Järvinen, Juho; Toivanen, Juho; Tanskanen, Juha P.

    2017-01-01

    Purpose. Potato fruit juice, a residue of starch industry, contains up to 2.5% [w/w] of proteins that are potentially valuable raw-materials of food, cosmetic, and pharma industries. The recovery of protein from the potato fruit juice is limited by the lack of industrially feasible concentration and separation technologies. The present research thus aimed at development of such process for the separation of active protease inhibitors from potato fruit juice. Methods. Low temperature mechanical vapor recompression evaporation was applied for concentration of potato fruit juice followed by ethanol precipitation for recovery of active proteins. The effects of precipitation temperature and precipitative agents were investigated employing response surface modeling methodology. Results. Concentration of potato fruit juice by evaporation was successful without loss of trypsin inhibition activity. Precipitation using 6.5 M ethanol at low temperature (0–+4°C) was found suitable for the recovery of active protease inhibitors from the concentrate. Piloting at starch industry yielded 50% of total proteins, with a high quantity of active protease inhibitors and a minor inclusion of other proteins. Conclusion. Concentration by low-temperature evaporation, followed by ethanol precipitation of protease inhibitors at optimized temperature, is an attractive option for valorization of potato fruit juice. PMID:28299232

  12. 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.

  13. 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.

  14. Self-separation of freestanding diamond films using graphite interlayers precipitated from C-dissolved Ni substrates

    NASA Astrophysics Data System (ADS)

    Ito, Shinya; Nagai, Masatsugu; Matsumoto, Tsubasa; Inokuma, Takao; Tokuda, Norio

    2017-07-01

    Freestanding diamond films were fabricated by a new self-separation method. Thick poly-crystalline diamond films were grown on poly-crystalline Ni substrates by microwave plasma-enhanced chemical vapor deposition after the substrates were saturated with carbon via a saturation process using a carbon solid solution. This saturation process suppressed the erosion of diamond nuclei on the Ni substrates. During the cooling process after diamond growth, the carbon atoms dissolved in the Ni substrates became supersaturated and precipitated as graphite interlayers at the interfaces between the diamond films and Ni substrates. The graphite interlayers caused the thick diamond films to spontaneously separate from the Ni substrates without cracking, allowing the Ni substrates to be reused. This self-separation method provides a low-cost way to fabricate freestanding diamond films.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Computational simulation of the blood separation process.

    PubMed

    De Gruttola, Sandro; Boomsma, Kevin; Poulikakos, Dimos; Ventikos, Yiannis

    2005-08-01

    The aim of this work is to construct a computational fluid dynamics model capable of simulating the quasitransient process of apheresis. To this end a Lagrangian-Eulerian model has been developed which tracks the blood particles within a delineated two-dimensional flow domain. Within the Eulerian method, the fluid flow conservation equations within the separator are solved. Taking the calculated values of the flow field and using a Lagrangian method, the displacement of the blood particles is calculated. Thus, the local blood density within the separator at a given time step is known. Subsequently, the flow field in the separator is recalculated. This process continues until a quasisteady behavior is reached. The simulations show good agreement with experimental results. They shows a complete separation of plasma and red blood cells, as well as nearly complete separation of red blood cells and platelets. The white blood cells build clusters in the low concentrate cell bed.

  20. 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

  1. 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.

  2. Extractive condensation: A new separation process

    SciTech Connect

    Zeitsch, K.J.

    1999-10-01

    A new highly selective vapor-phase extraction process is described. Hydrogen bonding between a scavenging extractant and the substance to be extracted results in a high-boiling complex forming fog droplets readily separable from the remaining vapor. The process is exemplified by the extraction of acetic acid from the predominantly aqueous vapor stream of furfural reactors. Triethylamine is used as the extractant.

  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. Process for separating anthracite coal from impurities

    SciTech Connect

    Stiller, D.W.; Stiller, A.H.

    1985-05-06

    A process is described for separating a first mixture including previously mined anthracite coal, klinker-type cinder ash and other refuse consisting of: a. separating the first mixture to produce a refuse portion and a second mixture consisting of anthracite and klinker-type cinder ash, b. reducing the average particle size in the second mixture to a uniform size, c. subjecting the second mixture to a separating magnetic field to produce a klinker-type cinder ash portion and an anthracite coal portion.

  5. Some basic aspects of reaction engineering of precipitation processes

    SciTech Connect

    Gandhi, K.S.; Kumar, R. |; Ramkrishna, D.

    1995-10-01

    The technology of modern ceramic materials has provided a fresh breath to the reaction engineering of precipitation processes. Analysis of precipitation reactions is extremely important in the technology of production of fine particles from the liquid phase. The control of composition and particle size in precipitation processes requires careful analysis of the several reactions that comprise the precipitation system. Since precipitation systems involve several, rapid ionic dissociation reactions among other slower ones, the faster reactions may be assumed to be nearly at equilibrium. However, the elimination of species, and the consequent reduction of the system of equations, is an aspect of analysis fraught with the possibility of subtle errors related to the violation of conservation principles. This paper show how such errors may be avoided systematically by relying on the methods of linear algebra. Applications are demonstrated by analyzing the reactions leading to the precipitation of calcium carbonate in a stirred tank reactor as well as in single emulsion drop. Sample calculations show that supersaturation dynamics can assume forms that can lead to subsequent dissolution of particles that have once been precipitated.

  6. 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.

  7. Antisolvent precipitation of water-soluble hemicelluloses from TMP process water.

    PubMed

    Zasadowski, Dariusz; Yang, Jiayi; Edlund, Håkan; Norgren, Magnus

    2014-11-26

    During the thermomechanical pulping (TMP) of spruce, hemicelluloses (mainly galactoglucomannans, GGMs) are released into the process water at relatively low concentrations that are currently impossible to efficiently recover. This paper examines the recovery of hemicelluloses precipitated from TMP process water via solubility reduction by adding antisolvents such as methanol, ethanol, and acetone. The phase separation was monitored by turbidity measurements. Gravimetric analysis, FTIR, GC-MS, UV spectroscopy, and ICP-OES were used to determine the yield, purity, and composition of the precipitates. Gel permeation chromatography and pulsed field-gradient self-diffusion NMR were used to measure the molecular mass distribution of the precipitates. Acetone was found to be the most efficient antisolvent, giving the highest yield at the lowest addition. The contents of lipophilic extractives and lignin impurities were below 0.5% and 1.6%, respectively, and the metal content was approximately 2% in the precipitates obtained with acetone. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Air separation by the Moltox process

    SciTech Connect

    Erickson, D. C.

    1981-04-01

    The report describes results of a development program on a new and energy saving process for air separation. The Moltox process involves reversibly reacting oxygen in air with a recirculating salt solution, such that oxygen is extracted without depressurizing the remaining nitrogen. Energy savings of approximately 50% are indicated for this process compared to conventional cryogenic air separation. The development program consisted of design, construction, and operation of a 6 liter/minute pilot plant; optimization of the process flowsheet through computer modelling; investigation of engineering aspects of the process including corrosion, safety, and NO/sub x/ generation; and an economic comparison to conventional cryogenic practice. All objectives were satisfactorily achieved except for continuous operation of the pilot plant, and the modifications necessary to achieve that have been identified. Economically the Moltox process shows a substantial advantage over large scale cryogenic plants which are powered by fuel vice electricity.

  9. Integrated Precipitation and Hydrology Experiment (IPHEx)/Orographic Precipitation Processes Study Field Campaign Report

    SciTech Connect

    Barros, A. P.; Petersen, W.; Wilson, A. M.

    2016-04-01

    Three Microwave Radiometers (two 3-channel and one 2-channel) were deployed in the Southern Appalachian Mountains in western North Carolina as part of the Integrated Precipitation and Hydrology Experiment (IPHEx), which was the first National Aeronautics and Space Administration (NASA) Global Precipitation Mission (GPM) Ground Validation (GV) field campaign after the launch of the GPM Core Satellite (Barros et al. 2014). The radiometers were used along with other instrumentation to estimate the liquid water content of low-level clouds and fog. Specifically, data from the radiometers were collected to help, with other instrumentation, to characterize fog formation, evolution, and dissipation in the region (by monitoring the liquid water path in the column) and observe the effect of that fog on the precipitation regime. Data were collected at three locations in the Southern Appalachians, specifically western North Carolina: a valley in the inner mountain region, a valley in the open mountain pass region, and a ridge in the inner region. This project contributes to the U.S. Department of Energy (DOE)’s Atmospheric Radiation Measurement (ARM) Climate Research Facility mission by providing in situ observations designed to improve the understanding of clouds and precipitation processes in complex terrain. The end goal is to use this improved understanding of physical processes to improve remote-sensing algorithms and representations of orographic precipitation microphysics in climate and earth system models.

  10. Silicate Removal in Aluminum Hydroxide Co-Precipitation Process

    PubMed Central

    Tokoro, Chiharu; Suzuki, Shinya; Haraguchi, Daisuke; Izawa, Sayaka

    2014-01-01

    The removal mechanisms of silicate using an aluminum hydroxide co-precipitation process was investigated and compared with an adsorption process, in order to establish an effective and validated method for silicate removal from wastewater. Adsorption isotherms, XRD and FT-IR analyses showed that silicate uptake occurred by adsorption to boehmite for initial Si/Al molar ratios smaller than two, but by precipitation of poorly crystalline kaolinite for the ratios larger than two, in both co-precipitation and adsorption processes. Silicate was removed by two steps: (i) an initial rapid uptake in a few seconds; and (ii) a slow uptake over several hours in both processes. The uptake rate in the first step was higher in the co-precipitation process than in adsorption process, presumably due to increased silicate adsorption to boehmite and rapid precipitation of kaolinite. These results suggest that silicate removal using aluminum salts could be effectively achieved if the pH adjustment and aluminum concentration are strictly controlled. PMID:28788501

  11. 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.

  12. 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.

  13. Modeling Cloud and Precipitation Processes - Considerations for Future Satellite Missions

    NASA Astrophysics Data System (ADS)

    van den Heever, S. C.; Tao, W. K.; Saleeby, S. M.; Wu, D.

    2014-12-01

    Rapid developments in computing resources have allowed for cloud resolving model (CRM) simulations to be conducted over larger domains at higher spatial and temporal resolutions. Indeed, global CRMs are now a reality. Within such modeling frameworks, microphysical processes cannot be isolated from the vertical velocity that drives them, from the impact of energy exchanges due to phase changes, nor from the precipitation they produce, as has historically been the case with more highly parameterized frameworks. The increasing utilization of such high resolution, large-domain CRMs therefore introduces a new set of observational challenges. Instead of only taking into account global distributions of clouds and precipitation, observational strategies now need to be adapted to focus on the actual microphysical processes and feedbacks that are responsible for such cloud and precipitation distributions. Incorrectly representing such processes and feedbacks has significant implications for precipitation rates, efficiency and partitioning; the horizontal and vertical distribution of clouds; anvil ice properties; the partitioning between the liquid water and ice phase; and the location and amount of latent energy release associated with phase changes, all of which have subsequent implications for the global energy and water budget. Numerous microphysical and dynamical processes, and the feedbacks between them, are not well represented in CRMs. However, correctly simulating the magnitude of vertical velocity, as well as various ice processes appear to be particularly challenging. This talk will focus on the range of precipitation and cloud responses obtained within CRM simulations due to changes in the manner various ice processes are represented including melting, riming and shedding. Those parameters causing the greatest simulated cloud and precipitation responses will be identified. Factors impacting the representation of vertical velocity will also be addressed. Finally

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. a Numerical Study of Precipitation Processes in Stable Orographic Storms

    NASA Astrophysics Data System (ADS)

    Oolman, Larry David

    A numerical model has been developed to retrieve the microphysical and precipitation process of clouds utilizing the kinematic fields obtained from Doppler radar. This model uses parameterized bulk microphysics in which the water condensate is divided into three classes: cloud water, rain, and snow. The model was applied to a deep, stable orographic storm over the Sierra Nevada. The simulations indicated that these storms precipitate with a 90% efficiency. The time scale for a parcel to traverse the barrier is sufficiently long for precipitation processes to be effective. Modifying parameters in the model merely shifts the relative importance of various processes and has little effect on the precipitation efficiency. Only by shortening the parcel transit time, such as by increasing the wind velocity, does the precipitation efficiency decrease. The predicted ice particle spectra from the model agree quite well with the actual spectra from the Wyoming King Air aircraft through most of the interior of the cloud. The spectra does not agree as well near the cloud edges. Entrainment, which was not included in the model, may be an important process in these regions.

  19. [Trace Analysis of Lead in Copper Gluconate by Atomic Absorption Spectrometry after Separation by Co-Precipitation with Bismuth].

    PubMed

    Ito, Michio; Ishiguro, Satoshi; Takahashi, Fumihito; Nomura, Takakazu; Sugimoto, Toshiaki; Nishimura, Tsutomu

    2015-01-01

    In order to determine trace amounts of lead in copper gluconate by atomic absorption spectrometry (AAS), the authors investigated a separation and pre-concentration procedure using a co-precipitation technique with bismuth. After ashing 2.0 g of the sample by means of a dry process, the ash was dissolved in (1→100) nitric acid and 75 μg of bismuth was added. Lead was co-precipitated by using an ammonium solution controlled to pH 9.5-10.5. The precipitate was left at room temperature for over 15 minutes to age, and then washed with a (3→100) ammonium solution three times. The precipitate was dissolved in (1→100) nitric acid and then analyzed by AAS. The quantification limit of this method was 0.5 mg/kg, and the trueness, repeatability and intermediate precision were 99.6%, 4.2% and 4.2% at the spiked concentration of 0.5 mg/kg, and 94.4%, 2.8% and 4.0% at the spiked concentration of 5.0 mg/kg, respectively. Thus, the present method for trace analysis of lead in copper gluconate was validated.

  20. Separation of platinum and rhodium from chloride solutions containing aluminum, magnesium and iron using solvent extraction and precipitation methods.

    PubMed

    Raju, B; Kumar, J Rajesh; Lee, Jin-Young; Kwonc, Hyuk-Sung; Kantam, M Lakshmi; Reddy, B Ramachandra

    2012-08-15

    The solvent extraction and precipitation methods have been used to develop a process to separate platinum and rhodium from a synthetic chloride solutions containing other associated metals such as (mg/L): Pt-364, Rh-62, Al-13880, Mg-6980, Fe-1308 at <1M HCl acidity. At pH 3.4, the quantitative precipitation of Al and Fe was achieved using 10 wt% Na(3)PO(4)·12H(2)O, with ~4% loss of Pt and Rh due to adsorption phenomenon. The selective separation of platinum was carried out with 0.01 M Aliquat 336 (a quaternary ammonium salt) at an aqueous to organic ratio (A/O) of 3.3 in two stages. Stripping of Pt from loaded organic (LO) at O/A ratio 6 with 0.5 M thiourea (tu) and HCl indicated that ~99.9% stripping efficiency. In stripping studies, needle like crystals of Pt were found and identified as tetrakis (thiourea) platinum (II) chloride ([Pt(tu)(4)]Cl(2)). The selective precipitation of rhodium was performed with (NH(4))(2)S from platinum free raffinate with a recovery of >99%. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. 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.

  2. Numerical modeling of mineral dissolution - precipitation kinetics integrating interfacial processes

    NASA Astrophysics Data System (ADS)

    Azaroual, M. M.

    2016-12-01

    The mechanisms of mineral dissolution/precipitation are complex and interdependent. Within a same rock, the geochemical modelling may have to manage kinetic reactions with high ratios between the most reactive minerals (i.e., carbonates, sulfate salts, etc.) and less reactive minerals (i.e., silica, alumino-silicates, etc.). These ratios (higher than 10+6) induce numerical instabilities for calculating mass and energy transfers between minerals and aqueous phases at the appropriate scales of time and space. The current scientific debate includes: i) changes (or not) of the mineral reactive surface with the progress of the dissolution/precipitation reactions; ii) energy jumps (discontinuity) in the thermodynamic affinity function of some dissolution/precipitation reactions and iii) integration of processes at the "mineral - aqueous solution" interfaces for alumino-silicates, silica and carbonates. In recent works dealing with the specific case of amorphous silica, measurements were performed on nano-metric cross-sections indicating the presence of surface layer between the bulk solution and the mineral. This thin layer is composed by amorphous silica and hydrated silica "permeable" to the transfer of water and ionic chemical constituents. The boundary/interface between the initial mineral and the silica layer is characterized by a high concentration jump of chemical products at the nanoscale and some specific interfacial dissolution/precipitation processes.In this study, the results of numerical simulations dealing with different mechanisms of silicate and carbonate dissolution/precipitation reactions and integrating interfacial processes will be discussed. The application of this approach to silica precipitation is based on laboratory experiments and it highlights the significant role of the "titration" surface induced by surface complexation reactions in the determination of the kinetics of precipitation.

  3. 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.

  4. 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

  5. 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.

  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. 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.

  8. 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.

  9. Optimization of magnetite carrier precipitation process for transuranic waste reduction

    SciTech Connect

    Slater, S.A.; Chamberlain, D.B.; Aase, S.A.; Babcock, B.D.; Conner, C.; Sedlet, J.; Vandegrift, G.F.

    1995-12-31

    Transuranic (TRU) waste that is being generated at Argonne National Laboratory has a TRU activity ranging from 10{sup 2} to 10{sup 7} nCi/g with a wide variety of chemical compositions. Currently, the waste is stored in highly acidic solutions that must be neutralized for intermediate storage. A magnetite carrier precipitation process has been adapted to concentrate TRU isotopes in a noncorrosive solid phase. In this paper, the authors report the results of a series of laboratory tests done to optimize the process. The parameters they optimized included (1) magnetite concentration used to precipitate the TRUs from solution, (2) formation of magnetite (in situ or ex situ), (3) processing pH, and (4) temperature and mixing time of the carrier precipitation. They also studied the effects of anions, cations, and complexing agents in the waste solutions on the carrier precipitation and the effect of magnetite solids loading on the filtration equipment. An overview is given of the planned full-scale process, which will be operated in a glovebox.

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. Metal separation from mixed types of batteries using selective precipitation and liquid-liquid extraction techniques.

    PubMed

    Provazi, Kellie; Campos, Beatriz Amaral; Espinosa, Denise Crocce Romano; Tenório, Jorge Alberto Soares

    2011-01-01

    The purpose of this paper is to study metal separation from a sample composed of a mixture of the main types of spent household batteries, using a hydrometallurgical route, comparing selective precipitation and liquid-liquid extraction separation techniques. The preparation of the solution consisted of: grinding the waste of mixed batteries, reduction and volatile metals elimination using electric furnace and acid leaching. From this solution two different routes were studied: selective precipitation with sodium hydroxide and liquid-liquid extraction using Cyanex 272 [bis(2,4,4-trimethylpentyl) phosphoric acid] as extracting agent. The best results were obtained from liquid-liquid extraction in which Zn had a 99% extraction rate at pH 2.5. More than 95% Fe was extracted at pH 7.0, the same pH at which more than 90% Ce was extracted. About 88% Mn, Cr and Co was extracted at this pH. At pH 3.0, more than 85% Ni was extracted, and at pH 3.5 more than 80% of Cd and La was extracted.

  15. Efficient Separations and Processing Integrated Program

    SciTech Connect

    Fryberger, T.

    1994-12-31

    The Efficient Separations and Processing Integrated Program (ESP-IP) was created in 1991 to support the Department of Energy`s (DOE) weapons complex cleanup effort. The Office within DOE responsible for the cleanup is the Office of Environmental Restoration and Waste Management (EM). The goal of EM is to minimize risks to human health and the environment, and bring DOE sites in regulatory compliance by the year 2019. EM established the Office of Technology Development (OTD) to develop new technologies that are safer, faster, more effective and less expensive than current methods. In an effort to focus resources and address opportunities, OTD has developed Integrated Programs (IPs) to support applied research activities in key application areas required in each stage of the remediation process (e.g. characterization, treatment, disposal). The mission of the ESP-IP is to identify, develop, and coordinate technologies for economical separation of toxic components from wastes that have accumulated at DOE sites since the mid-1940s. 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. These wastes include: high-level radioactive wastes stored in underground tanks, transuranic wastes, low-level radioactive wastes and mixed wastes buried in landfills, contaminated soils, and contaminated groundwater.

  16. 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

  17. Novel disk modules for membrane separation processes

    SciTech Connect

    Siler, J.L.

    1993-12-06

    The reverse osmosis (RO) system at the Effluent Treatment Facility (ETF) at the Savannah River Site, Aiken, South Carolina has experienced fouling from trace quantities of inorganics (Al, Fe, and Si) and l.E5-l.E7/ml bacteria. The bacteria are primarily produced in an upstream Hg-removal resin bed/activated carbon bed process. The bacteria adhere to the colloidal inorganics that are in the membrane feed at their solubility limits (having been precipitated and removed upstream by a ceramic microfilter system). The resulting bacterial/inorganic foulant adheres to the membrane surface and results in high feed pressures and poor salt rejection. The feed pressure increases because the membrane system at the ETF is designed to produce a constant rate of treated water, or permeate. This is accomplished by increasing the membrane feed pressure whenever permeate flow drops. These performance losses have been attributed to bacteria present in the feed, and several potential solutions have been proposed and demonstrated here at the Savannah River Technology Center (SRTC). Advanced hybrid plate-and-frame modules have been developed that increase the applicability of membrane systems by using hydrodynamics rather than pretreatment to prevent membrane fouling.

  18. 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.

  19. 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.

  20. Liquid-liquid phase separation in supersaturated lysozyme solutions and associated precipitate formation/crystallization

    NASA Astrophysics Data System (ADS)

    Muschol, Martin; Rosenberger, Franz

    1997-08-01

    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% (w/v) 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.

  1. 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.

  2. 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.

  3. 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.

  4. Development of an ELP-Z based mAb affinity precipitation process using scaled-down filtration techniques.

    PubMed

    Sheth, Rahul D; Bhut, Bharat V; Jin, Mi; Li, Zhengjian; Chen, Wilfred; Cramer, Steven M

    2014-12-20

    In this work, a proof of concept elastin-like polypeptide-Z domain fusion (ELP-Z) based monoclonal antibody (mAb) affinity precipitation process is developed using scaled-down filtration techniques. Tangential flow filtration (TFF) is examined for the recovery of ELP-Z-mAb precipitates formed during the mAb binding step and the ELP-Z precipitates formed during the mAb elution step. TFF results in complete precipitate recovery during both stages of the process and high host cell protein and DNA impurity clearance after diafiltration. Total recycle TFF experiments are then employed to determine permeate flux as a function of the precipitate concentration for both stages of the process. While the ELP-Z-mAb precipitate recovery step resulted in high permeate flux (550-600L/m(2)/h/bar), the ELP-Z precipitates are shown to severely foul the TFF membrane, causing rapid flux decay. Confocal microscopy of the ELP-Z-mAb and ELP-Z precipitates suggests significant differences in the morphology and the kinetics of formation of these precipitates, which is likely responsible for their different behavior during TFF. Finally, an alternative normal flow filtration strategy is developed for the ELP-Z precipitate recovery step during mAb elution, using a combination of 5μm and a 0.45/0.2μm filters. Using this approach, the ELP-Z precipitates are separated from the final mAb elution pool at high volumetric throughputs and high ELP-Z recovery (96%) is obtained after resolubilization from the filter. This study demonstrates that the ELP-Z affinity precipitation process can be readily scaled up using conventional membrane processing.

  5. 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.

  6. A novel method for separation of caseins from milk by phosphates precipitation.

    PubMed

    Yen, Chon-Ho; Lin, Yin-Shen; Tu, Ching-Fu

    2015-01-01

    Milk protein of farm animals is difficult to isolate because of the presence of casein micelles, which are hard to separate from whey by using centrifugation or filtration. Insoluble casein micelles also create an obstacle for purification instruments to operate efficiently. The conventional method, to precipitate caseins by lowering pH to 4.6 and then recover the whey fraction for further purification using chromatography techniques, is not applicable to proteins having an isoelectric point similar to caseins. In addition, the acid condition used for casein removal usually leads to significantly poor yields and reduced biological activities. In this study, a novel method of precipitating caseins under neutral or weak acidic conditions is presented. The method employs a phosphate salt and a freeze-thaw procedure to obtain a casein-free whey protein fraction. This fraction contains more than 90% yield with little loss of bioactivity of the target protein, and is readily available for further chromatographic purification. This method was successfully applied to purify recombinant human factor IX and recombinant hirudin from the milk of transgenic pigs in the presented study. It is an efficient pretreatment approach prior to chromatographic purification of milk protein from farm animals and particularly of great value to collect those recombinants secreted from transgenic livestock.

  7. 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 %).

  8. 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.

  9. Process for the separation of landfill gas

    SciTech Connect

    O'Brien, J.V.; Holmes, A.S.; Hopewell, R.B.

    1987-07-21

    A recycle process is described for the separation of a landfill feed gas stream, having a high concentration of methane and carbon dioxide and containing undesirable trace gas impurities, into a fuel-or sales-grade gas methane product stream and a liquid carbon dioxide product stream, which process comprises: (a) introducing an essentially hydrogen-free, dried, compressed, landfill feed gas stream into a cryogenic distillation column; (b) withdrawing a methane-enriched overhead product stream from the distillation column; (c) withdrawing an enriched liquid carbon dioxide bottom product stream, containing a major amount of the undesirable impurities, from the distillation column; (d) introducing the methane-enriched overhead product stream into a gas-permeation membrane apparatus; (e) withdrawing from the membrane apparatus a sales- or fuel-grade gas methane product stream; (f) withdrawing from the membrane apparatus a carbon-dioxide-enriched gas permeate stream; (g) compressing the carbon-dioxide-enriched gas permeate stream; and (h) recycling the compressed permeate stream for use in the process.

  10. 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

  11. Liquid antisolvent precipitation process for solubility modulation of bicalutamide.

    PubMed

    Meer, Tarique Ali; Sawant, Kiran P; Amin, Purnima D

    2011-12-01

    Liquid antisolvent process was explored as a solubility modulating tool. Bicalutamide, a poorly water soluble drug, was used as a candidate. Low aqueous solubility and poor dissolution of bicalutamide results into poor and variable bioavailability. Therefore, the objective of the present work was to modify the solubility of bicalutamide using the liquid antisolvent precipitation process. HPMC E5 and Poloxamer 407 were shortlisted as a hydrophilic polymer and surfactant, respectively, for the process. Process optimization was done with respect to the hydrophilic polymer, surfactant and drug loading concentration. The resultant microcrystals were characterized with various instrumental techniques for material characterization such as IR, DSC, SEM, XRD, particle size, specific surface area and dissolution kinetics.

  12. 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

  13. 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.

  14. Actinide and lanthanide separation process (ALSEP)

    DOEpatents

    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).

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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).

  5. 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).

  6. 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.

  7. 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.

  8. 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.

  9. Wet separation processes as method to separate limestone and oil shale

    NASA Astrophysics Data System (ADS)

    Nurme, Martin; Karu, Veiko

    2015-04-01

    Biggest oil shale industry is located in Estonia. Oil shale usage is mainly for electricity generation, shale oil generation and cement production. All these processes need certain quality oil shale. Oil shale seam have interlayer limestone layers. To use oil shale in production, it is needed to separate oil shale and limestone. A key challenge is find separation process when we can get the best quality for all product types. In oil shale separation typically has been used heavy media separation process. There are tested also different types of separation processes before: wet separation, pneumatic separation. Now oil shale industry moves more to oil production and this needs innovation methods for separation to ensure fuel quality and the changes in quality. The pilot unit test with Allmineral ALLJIG have pointed out that the suitable new innovation way for oil shale separation can be wet separation with gravity, where material by pulsating water forming layers of grains according to their density and subsequently separates the heavy material (limestone) from the stratified material (oil shale)bed. Main aim of this research is to find the suitable separation process for oil shale, that the products have highest quality. The expected results can be used also for developing separation processes for phosphorite rock or all others, where traditional separation processes doesn't work property. This research is part of the study Sustainable and environmentally acceptable Oil shale mining No. 3.2.0501.11-0025 http://mi.ttu.ee/etp and the project B36 Extraction and processing of rock with selective methods - http://mi.ttu.ee/separation; http://mi.ttu.ee/miningwaste/

  10. 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,…

  11. 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,…

  12. 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.

  13. Responses of Precipitation and Hydrologic Processes to Tropical SST

    NASA Technical Reports Server (NTRS)

    Sui, C.-H.; Lau, K.-M.; Li, X.

    2001-01-01

    The goal of the research is to identify the mechanisms in the response of tropical precipitation and atmospheric hydrologic cycle to sea surface temperature (SST) variability at seasonal-to-interannual time scales, and to utilize the knowledge for better understanding of climate feedback processes relevant to global change. As a first step to achieve the goal, we characterize the inter-relationship among convective/stratiform rain, ice/water clouds water vapor, and SST using TRMM satellite data and a cloud-resolving model. We examined the daily hydrologic variables [column water vapor (PW), cloud liquid water (CW), rainfall rates (RR)] as a function of SST using high-resolution data (0.25 x 0.25, daily) derived from TRMM satellite measurements. Comparing the winter of 97/98 (El Nino condition) against the winter of 99/00 (La Nina condition), area-mean values of all four hydrologic variables in cloudy areas within the tropical Pacific are higher in the El Nino winter than in the La Nina winter. This is consistent with previous observational analyses and SST warming experiments (idealized or ENSO-like) that showed the interaction between hydrologic cyclic and radiation at the seasonal to interannual time scales leads to intensified tropical circulation and hydrologic cycle. However, there is evidence that the enhanced hydrologic cycle over the warm pool is accompanied by an expansion of radiatively -driven subsidence in response to a stronger SST gradient between warm pool and surrounding cold pool. The expanding subsidence effectively reduces cloud amounts over the warm pool. Our analysis of daily variability further indicates a more vigorous water cycle characterized by higher PW, CW, and RR in response to overall warming. This is expected from the Clausius Clapeyron relation as a thermodynamic response to warming. However cloudy areas decrease in response to overall warming. This may be due to factors that are fundamentally different. One possibility is that in a

  14. 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.

  15. Two-Stage Process for Precipitating Coarse Boehmite from Sodium Aluminate Solution

    NASA Astrophysics Data System (ADS)

    Liu, Guihua; Li, Zheng; Qi, Tiangui; Li, Xiaobin; Zhou, Qiusheng; Peng, Zhihong

    2017-10-01

    To increase the precipitation rate significantly and obtain sandy alumina, a two-stage seeded precipitation process for preparing coarse boehmite was studied. In the first stage, which involved gibbsite precipitation, the fresh fine gibbsite, along with the active seed of less than 20 g L-1, acted as seed. An estimated 70% precipitation rate was achieved in the concentrated sodium aluminate solution at 45°C for 20 h. In the second stage, which involved boehmite precipitation, the fine gibbsite played a dual function in dissolution and as seed. After gibbsite was dissolved into the solution and boehmite was precipitated, uniform coarse boehmite was precipitated from sodium aluminate solution at 95°C for 20 h. Extending the duration and adding boehmite as seed benefitted the formation of coarse boehmite and the transformation of gibbsite into boehmite. Finally, a precipitation process that remarkably increased the precipitation rate was presented.

  16. Two-Stage Process for Precipitating Coarse Boehmite from Sodium Aluminate Solution

    NASA Astrophysics Data System (ADS)

    Liu, Guihua; Li, Zheng; Qi, Tiangui; Li, Xiaobin; Zhou, Qiusheng; Peng, Zhihong

    2017-08-01

    To increase the precipitation rate significantly and obtain sandy alumina, a two-stage seeded precipitation process for preparing coarse boehmite was studied. In the first stage, which involved gibbsite precipitation, the fresh fine gibbsite, along with the active seed of less than 20 g L-1, acted as seed. An estimated 70% precipitation rate was achieved in the concentrated sodium aluminate solution at 45°C for 20 h. In the second stage, which involved boehmite precipitation, the fine gibbsite played a dual function in dissolution and as seed. After gibbsite was dissolved into the solution and boehmite was precipitated, uniform coarse boehmite was precipitated from sodium aluminate solution at 95°C for 20 h. Extending the duration and adding boehmite as seed benefitted the formation of coarse boehmite and the transformation of gibbsite into boehmite. Finally, a precipitation process that remarkably increased the precipitation rate was presented.

  17. 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.

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. Alternative washing strategy during in-tank precipitation processing

    SciTech Connect

    Walker, D.D.; Hobbs, D.T.

    1992-10-30

    If late washing of precipitate is available, it is possible to modify the normal washing phase of the ITP process so that tank corrosion is prevented by inhibiting with sodium hydroxide rather than sodium nitrite. Hydroxide inhibition has numerous advantages to a hydroxide/nitrite flowsheet.1 However, the rate of hydroxide depletion due to radiolysis and C0[sub 2] absorption were uncertainties. Based on recent experiments and calculations: hydroxide consumption by radiolysis will be 0.01 molar per month during Tank 49 storage, hydroxide depletion due to C0[sub 2] absorption will vary from 0.0006 to 0.025 molar per month for waste volumes between 50,000 and 1 million gallons and air flowrates between 100 and 200 cfm. A nominal rate of 0.006 molar/month (or less) is expected in Tank 49 after the first two ITP cycles have been completed. A material balance for the ITP process based on hydroxide inhibition has been calculated and the potential savings have been estimated.

  5. Alternative washing strategy during in-tank precipitation processing

    SciTech Connect

    Walker, D.D.; Hobbs, D.T.

    1992-10-30

    If late washing of precipitate is available, it is possible to modify the normal washing phase of the ITP process so that tank corrosion is prevented by inhibiting with sodium hydroxide rather than sodium nitrite. Hydroxide inhibition has numerous advantages to a hydroxide/nitrite flowsheet.1 However, the rate of hydroxide depletion due to radiolysis and C0{sub 2} absorption were uncertainties. Based on recent experiments and calculations: hydroxide consumption by radiolysis will be 0.01 molar per month during Tank 49 storage, hydroxide depletion due to C0{sub 2} absorption will vary from 0.0006 to 0.025 molar per month for waste volumes between 50,000 and 1 million gallons and air flowrates between 100 and 200 cfm. A nominal rate of 0.006 molar/month (or less) is expected in Tank 49 after the first two ITP cycles have been completed. A material balance for the ITP process based on hydroxide inhibition has been calculated and the potential savings have been estimated.

  6. Changes in chemical processes in soils caused by acid precipitation

    Treesearch

    Stephen A. Norton

    1976-01-01

    The acidification of precipitation is an accomplished fact. The only question that remains is whether the present trend of acidification is to continue into the future, and if so, to what degree. A related question is, are the consequences of acid precipitation reversible and to what extent, or over what time period? Research conducted over the last twenty years has...

  7. Feasibility studies for separation processes using environmentally sensitive hydrogels

    SciTech Connect

    Sassi, A.P.; Blanch, H.W.; Prausnitz, J.M.

    1994-12-01

    Temperature- and pH-sensitive hydrogels can be used to separate or concentrate proteins from dilute solution. Two possible separation processes are discussed here. Experimental partitioning data are used to compare the efficiencies of neutral, weakly acidic, weakly basic, and polyampholytic poly-N-isopropylacrylamide copolymer gels for separating cytochrome c from ovalbumin. For each process, attention is given to the influence of the solute partition coefficient and swelling equilibria on process efficiency.

  8. Membrane separation processes in the petrochemical industry

    SciTech Connect

    Li, N.N.; Funk, E.W.; Chang, Y.A.; Kulkarni, S.S.; Swamikannu, A.X.; White, L.S.

    1987-09-30

    This report provides an overview of a project with Allied-Signal which focused on developing new membrane technology with potential for energy conservation in the petrochemical industry. Three applications were investigated: (1) bulk removal of polar (sour) gases from natural gas using spiral-wound, cellulose acetate membranes; (2) recovery of solvent from solvent/heavy oil mixtures using polysulfone ultrafiltration membranes; and (3) separation of polar gases (e.g., H{sub 2}S and NH{sub 3} from H{sub 2}) using mixed-matrix, facilitated-transport membranes. This report summarizes laboratory research results performed in an earlier phase of this project and provides results from pilot-scale, field test studies and economic assessments.

  9. Glycerol extracting dealcoholization for the biodiesel separation process.

    PubMed

    Ye, Jianchu; Sha, Yong; Zhang, Yun; Yuan, Yunlong; Wu, Housheng

    2011-04-01

    By means of utilizing sunflower oil and Jatropha oil as raw oil respectively, the biodiesel transesterification production and the multi-stage extracting separation were carried out experimentally. Results indicate that dealcoholized crude glycerol can be utilized as the extracting agent to achieve effective separation of methanol from the methyl ester phase, and the glycerol content in the dealcoholized methyl esters is as low as 0.02 wt.%. For the biodiesel separation process utilizing glycerol extracting dealcoholization, its technical and equipment information were acquired through the rigorous process simulation in contrast to the traditional biodiesel distillation separation process, and results show that its energy consumption decrease about 35% in contrast to that of the distillation separation process. The glycerol extracting dealcoholization has sufficient feasibility and superiority for the biodiesel separation process.

  10. Microphase Separated Block Copolymers in Pervaporation Membranes for Biofuels Processing

    NASA Astrophysics Data System (ADS)

    Greer, Douglas; Shin, Chae-Young; Ozcam, Evren; Skerker, Jeffrey; Basso, Thalita; Leon, Dacia; Bauer, Stefan; Balsara, Nitash; Energy Biosciences Institute Collaboration

    2014-03-01

    The production of transportation biofuels requires numerous continuous separation processes. We designed block copolymer membranes for pervaporation as a means to achieve these separations. These block copolymers contain a glassy structure block for support and a rubbery transport block for sorption and diffusion. We create membranes with nanoscale conducting channels using the unique trait of block copolymers to assemble into ordered morphologies. We have previously used nanostructured membranes to separate ethanol/water binary mixtures [J. Membr. Sci. 373, 112 (2011)], [J. Membr. Sci. 401, 125 (2012)]. We report this type of membranes is effective in other, more complex separations important to biofuel production. These separations increase yield and decrease process time.

  11. Morphology, mineralogy, and solid-liquid phase separation characteristics of Cu and Zn precipitates produced with biogenic sulfide.

    PubMed

    Villa-Gomez, D K; van Hullebusch, E D; Maestro, R; Farges, F; Nikitenko, S; Kramer, H; Gonzalez-Gil, G; Lens, P N L

    2014-01-01

    The morphology, mineralogy, and solid-liquid phase separation of the Cu and Zn precipitates formed with sulfide produced in a sulfate-reducing bioreactor were studied at pH 3, 5, and 7. The precipitates formed at pH 7 display faster settling rates, better dewaterability, and higher concentrations of settleable solids as compared to the precipitates formed at pH 3 and 5. These differences were linked to the agglomeration of the sulfidic precipitates and coprecipitation of the phosphate added to the bioreactor influent. The Cu and Zn quenched the intensity of the dissolved organic matter peaks identified by fluorescence-excitation emission matrix spectroscopy, suggesting a binding mechanism that decreases supersaturation, especially at pH 5. X-ray absorption fine structure spectroscopy analyses confirmed the precipitation of Zn-S as sphalerite and Cu-S as covellite in all samples, but also revealed the presence of Zn sorbed on hydroxyapatite. These analyses further showed that CuS structures remained amorphous regardless of the pH, whereas the ZnS structure was more organized at pH 5 as compared to the ZnS formed at pH 3 and 7, in agreement with the cubic sphalerite-type structures observed through scanning electron microscopy at pH 5.

  12. A Course in Separations and Recovery Processes.

    ERIC Educational Resources Information Center

    Belfort, Georges

    1985-01-01

    Describes a course designed to: use approaches developed in the study of transport phenomena as a unifying foundation; provide students with an understanding of the design and operation of these proceses; and review particular advantages and limitations of the processes being studied. Course content and teaching methods are included. (JN)

  13. Precipitation Processes in the New Growth Zone of Alberta Hailstorms.

    NASA Astrophysics Data System (ADS)

    Krauss, Terrence William

    1981-06-01

    An investigation was made into the precipitation processes operating within the convective zone located upwind (with respect to the mid-level winds) of four severe Alberta hailstorms which occurred on 12 August 1978, 7 July 1979, 21 July 1979, and 22 July 1979. The main research tools employed were the University of Wyoming instrumented Queen-Air aircraft and the Alberta Research Council S-Band polarization diversity meteorological radar. The microphysical observations suggested that: (1) The hydrometeors in the shelf cloud were typically cloud droplets only. (2) Ice appeared only after turrets (feeder clouds) grew to temperatures colder than approximately -10 C. (3) Embryo sized particles formed as a result of the accretional growth of ice particles. (4) The first radar echo greater than 20 dBZ was due to 1 to 2 mm size graupel particles in concentrations from about 0.1 to .01 L('-1). A conceptual model was developed for each storm by synthesizing the aircraft data with the radar data. Evidence exists for a two stage hail growth process i.e. the embryos developed in the feeder clouds and then interacted with the weak-echo region (WER) of the main storm to grow to large hail. Observations showed that graupel particles produced by the feeder clouds were transported by the mid-level winds towards the WER of the main storm. Feeder clouds which merged with the storm produced fine-scale reflectivity patterns. The transfer of melted graupel particles from the feeder clouds to the WER at levels warmer than 0 C is thought to be the source of the frozen drop embryos found within some of the hailstones from these Alberta storms.

  14. 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.

  15. Processes of carbonate precipitation in modern microbial mats

    NASA Astrophysics Data System (ADS)

    Dupraz, Christophe; Reid, R. Pamela; Braissant, Olivier; Decho, Alan W.; Norman, R. Sean; Visscher, Pieter T.

    2009-10-01

    Microbial mats are ecosystems that arguably greatly affected the conditions of the biosphere on Earth through geological time. These laminated organosedimentary systems, which date back to > 3.4 Ga bp, are characterized by high metabolic rates, and coupled to this, rapid cycling of major elements on very small (mm-µm) scales. The activity of the mat communities has changed Earth's redox conditions (i.e. oxidation state) through oxygen and hydrogen production. Interpretation of fossil microbial mats and their potential role in alteration of the Earth's geochemical environment is challenging because these mats are generally not well preserved. Preservation of microbial mats in the fossil record can be enhanced through carbonate precipitation, resulting in the formation of lithified mats, or microbialites. Several types of microbially-mediated mineralization can be distinguished, including biologically-induced and biologically influenced mineralization. Biologically-induced mineralization results from the interaction between biological activity and the environment. Biologically-influenced mineralization is defined as passive mineralization of organic matter (biogenic or abiogenic in origin), whose properties influence crystal morphology and composition. We propose to use the term organomineralization sensu lato as an umbrella term encompassing biologically influenced and biologically induced mineralization. Key components of organomineralization sensu lato are the "alkalinity" engine (microbial metabolism and environmental conditions impacting the calcium carbonate saturation index) and an organic matrix comprised of extracellular polymeric substances (EPS), which may provide a template for carbonate nucleation. Here we review the specific role of microbes and the EPS matrix in various mineralization processes and discuss examples of modern aquatic (freshwater, marine and hypersaline) and terrestrial microbialites.

  16. 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.

  17. Preliminary evaluation of alternative ethanol/water separation processes

    SciTech Connect

    Eakin, D.E.; Donovan, J.M.; Cysewski, G.R.; Petty, S.E.; Maxham, J.V.

    1981-05-01

    Preliminary evaluation indicates that separation of ethanol and water can be accomplished with less energy than is now needed in conventional distillation processes. The state of development for these methods varies from laboratory investigation to commercially available processes. The processes investigated were categorized by type of separation depending on their ability to achieve varying degrees of ethanol/water separation. The following methods were investigated: ethanol extraction with CO/sub 2/ (the A.D. Little process); solvent extraction of ethanol; vacuum distillation; vapor recompression distillation; dehydration with fermentable grains; low temperature blending with gasoline; molecular sieve adsorption; and reverse osmosis.

  18. A pilot-scale study of cryolite precipitation from high fluoride-containing wastewater in a reaction-separation integrated reactor.

    PubMed

    Jiang, Ke; Zhou, Kanggen; Yang, Youcai; Du, Hu

    2013-07-01

    Fluoride removal by traditional precipitation generates huge amounts of a water-rich sludge with low quality, which has no commercial or industrial value. The present study evaluated the feasibility of recovering fluoride as low water content cryolite from industrial fluoride-containing wastewater. A novel pilot-scale reaction-separation integrated reactor was designed. The results showed that the seed retention time in the reactor was prolonged to strengthen the induced crystallization process. The particle size of cryolite increased with increasing seed retention time, which decreased the water content. The recovery rate of cryolite was above 75% under an influent fluoride concentration of 3500 mg/L, a reaction temperature of 500C, and an influent flow of 40 L/hr. The cryolite products that precipitated from the reactor were small in volume, large in particle size, low in water content, high in crystal purity, and recyclable.

  19. Cryogenic methane separation/catalytic hydrogasification process analysis. Quarterly report

    SciTech Connect

    Klosek, J.

    1981-08-01

    In both the Rockwell and the Exxon gasification processors, the desired product methane needs to be separated from the reaction products and some of the other synthesis gas products recycled. This separation is not easy and cryogenic methane separation results from the Rockwell process gas at 932 psia and containing 3725 ppM of benzene are reported. The benzene was recovered by partial condensation and carbon adsorption. Other details are given. In the Exxon process three preliminary plant designs for acid gas removal and cryogenic methane separation from the raw gas at 250 psig were evaluated. (LTN)

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. Recovery of metals from Cuban nickel tailings by leaching with organic acids followed by precipitation and magnetic separation.

    PubMed

    Hernández, C M F; Banza, A N; Gock, E

    2007-01-02

    The percolation leaching of the Cuban nickel tailings containing 0.34% Ni, 0.08% Co and 44.2% Fe was investigated by using tartaric and oxalic acids at different concentrations. About 70% Ni, 80% Co and 30% Fe were extracted after 5 days of leaching with the mixture of 0.15 mol/L tartaric acid and 0.05 mol/L oxalic acid at ambient temperature and normal pressure. Nickel and cobalt extraction of 80% as well as iron extraction of 50% were achieved from the pregnant solution by means of precipitation at 80 degrees C for 2h. The precipitation at ambient temperature led to a similar result after 16 days. Cobalt, nickel and iron oxalates were found in the precipitate by using the X-ray diffraction method. The regeneration of acids during the precipitation step made possible the reuse of the raffinate at the leaching step. Heating of the precipitate at 200 degrees C increased the metal concentration to 1.22% Ni and 0.33% Co, which can be fed in the existing nickel plant in Moa, Cuba. The magnetic processing of the leaching residues led to a non-magnetic product containing less than 20% Fe and a magnetic product containing more than 50% Fe.

  5. 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.

  6. 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.

  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. Unsteady separation process and vorticity balance on unsteady airfoils

    NASA Technical Reports Server (NTRS)

    Ho, Chih-Ming; Gursul, Ismet; Shih, Chiang; Lin, Hank

    1992-01-01

    Low momentum fluid erupts at the unsteady separation region and forms a local shear layer at the viscous-inviscid interface. At the shear layer, the vorticity lumps into a vortex and protrudes into the inviscid region. This process initiates the separation process. The response of airfoils in unsteady free stream was investigated based on this vortex generation and convection concept. This approach enabled us to understand the complicated unsteady aerodynamics from a fundamental point of view.

  9. 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.

  10. 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.

  11. 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.

  12. Treatment of a waste salt delivered from an electrorefining process by an oxidative precipitation of the rare earth elements

    NASA Astrophysics Data System (ADS)

    Cho, Yung-Zun; Yang, Hee-Chul; Park, Gil-Ho; Lee, Han-Soo; Kim, In-Tae

    2009-02-01

    For the reuse of a waste salt from an electrorefining process of a spent oxide fuel, a separation of rare earth elements by an oxidative precipitation in a LiCl-KCl molten salt was tested without using precipitate agents. From the results obtained from the thermochemical calculations by HSC Chemistry software, the most stable rare earth compounds in the oxygen-used rare earth chlorides system were oxychlorides (EuOCl, NdOCl, PrOCl) and oxides (CeO 2, PrO 2), which coincide well with results of the Gibbs free energy of the reaction. In this study, similar to the thermochemical results, regardless of the sparging time and molten salt temperature, oxychlorides and oxides were formed as a precipitant by a reaction with oxygen. The structure of the rare earth precipitates was divided into two shapes: small cubic (oxide) and large plate-like (tetragonal) structures. The conversion efficiencies of the rare earth elements to their molten salt-insoluble precipitates were increased with the sparging time and temperature, and Ce showed the best reactivity. In the conditions of 650 °C of the molten salt temperature and 420 min of the sparging time, the final conversion efficiencies were over 99.9% for all the investigated rare earth chlorides.

  13. 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)

  14. Comparative proteomic analysis of casein and whey as prepared by chymosin-induced separation, isoelectric precipitation or ultracentrifugation.

    PubMed

    Jensen, Hanne B; Poulsen, Nina A; Møller, Hanne S; Stensballe, Allan; Larsen, Lotte B

    2012-11-01

    Fractionation of bovine milk was performed using chymosin-induced separation, isoelectric precipitation or ultracentrifugation as separation techniques prior to gel-based proteomic analysis. This approach allowed for comparative display and identification of proteins partitioned into casein and whey, respectively. Initially, three different staining methods (silver staining, colloidal Coomassie Blue G-250 or fluorescent Flamingo Pink staining) for two-dimensional gel electrophoresis (2-DGE) analysis were compared for their suitability as staining agent, especially in relation to their suitability to reveal differences in the casein fractions. Fluorescent staining proved to be the most appropriate for this purpose, giving a high sensitivity, and using this staining method, characteristic 2-DGE fingerprints were obtained for each casein and whey fraction from each separation method. A number of protein spots in both casein and whey fractions varied with separation method and these spots were subsequently identified using tandem mass spectrometry (MS). In rennet casein, proteolytic fragmentation of caseins (α(s1)-, α(s2),-, β- and κ-) was identified as a result of chymosin hydrolysis, whereas the 2-DGE profile of acid and ultracentrifuged casein was dominated by the presence of multiple isoforms of κ-caseins. Furthermore, casein remnants were identified in milk serum after ultracentrifugation. This study shows that gel-based proteomic analysis is suitable for characterisation of subtle variations in protein composition of milk fractions that occur as a consequence of different milk fractionation strategies.

  15. 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)

  16. 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)

  17. PROCESS OF SEPARATING URANIUM FROM AQUEOUS SOLUTION BY SOLVENT EXTRACTION

    DOEpatents

    Warf, J.C.

    1958-08-19

    A process is described for separating uranium values from aqueous uranyl nitrate solutions. The process consists in contacting the uramium bearing solution with an organic solvent, tributyl phosphate, preferably diluted with a less viscous organic liquida whereby the uranyl nitrate is extracted into the organic solvent phase. The uranvl nitrate may be recovered from the solvent phase bv back extracting with an aqueous mediuin.

  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. Preparative fractionation of protein, RNA, and plasmid DNA using centrifugal precipitation chromatography with tubular dialysis membrane inside a convoluted tubing as separation channel.

    PubMed

    Tomanee, Panarat; Hsu, James T; Ito, Yoichiro

    2006-01-01

    Fractionation of clarified E. coli lysate components in bench-scale and preparative-scale centrifugal precipitation chromatography (CPC), using a solution of cationic surfactant cetyltrimethylammonium bromide (CTAB) containing 0.5 M NaCl as precipitant, are compared here. Step gradient of CTAB from 0.50% to 0.16% (w/v) gave a successful fractionation in bench-scale CPC; however, a linear gradient of lower CTAB concentration, 0.20-0% (w/v), was used in the preparative scale and resulted in similar fractionation. The preparative-scale CPC has a superior sample loading capacity by the use of tubular dialysis membrane inside convoluted tubing as the separation channel. In this study, the quantity of the sample loaded into the preparative CPC was about 15 times more than that in the bench scale, and in a single run the preparative CPC could prepare approximately 3 mg of plasmid DNA with about 96% of RNA removed. The higher surface area per length of the separation channel in the preparative CPC was believed to benefit mass transfer of CTAB across the membrane, leading to less CTAB being required in the process.

  20. Advanced process for precipitation of lignin from ethanol organosolv spent liquors.

    PubMed

    Schulze, Peter; Seidel-Morgenstern, Andreas; Lorenz, Heike; Leschinsky, Moritz; Unkelbach, Gerd

    2016-01-01

    An advanced process for lignin precipitation from organosolv spent liquors based on ethanol evaporation was developed. The process avoids lignin incrustations in the reactor, enhances filterability of the precipitated lignin particles and significantly reduces the liquor mass in downstream processes. Initially, lignin solubility and softening properties were understood, quantified and exploited to design an improved precipitation process. Lignin incrustations were avoided by targeted precipitation of solid lignin at specific conditions (e.g. 100 mbar evaporation pressure, 43°C and 10%wt. of ethanol in lignin dispersion) in fed-batch operation at lab and pilot scale. As result of evaporation the mass of spent liquor was reduced by about 50%wt., thus avoiding large process streams. By controlled droplet coalescence the mean lignin particle size increased from below 10 μm to sizes larger than 10 μm improving the significantly filterability.

  1. Purification of antibodies by precipitating impurities using Polyethylene Glycol to enable a two chromatography step process.

    PubMed

    Giese, Glen; Myrold, Adam; Gorrell, Jeffrey; Persson, Josefine

    2013-11-01

    The purification of antibodies by precipitating impurities using Polyethylene Glycol (PEG) was assessed with the objective of developing a two chromatography column purification process. A PEG precipitation method was evaluated for use in the industrial purification of recombinant monoclonal antibodies (MAbs). Effective and robust precipitation conditions including PEG concentration, pH, temperature, time, and protein concentration were identified for several different MAbs. A recovery process using two chromatography steps in combination with PEG precipitation gave acceptable yield and purity levels for IgG1 and IgG4 antibodies with a broad range of isoelectric points (pI). PEG precipitation removed host cell proteins (HCPs), high molecular weight species (HMWS), leached Protein A ligand, and host cell DNA to acceptable levels when run under appropriate conditions, and some endogenous virus removal was achieved.

  2. Air separation by the Moltox process. Interim final report

    SciTech Connect

    Erickson, D.C.

    1981-04-01

    Results are described of a development program on a new and energy-saving process for air separation. The Moltox process involves reversibly reacting oxygen in air with a recirculating salt solution, such that oxygen is extracted without depressurizing the remaining nitrogen. Energy savings of approximately 50% are indicated for this process compared to conventional cryogenic air separation. The development program consisted of design, construction, and operation of a 6 liter/minute pilot plant; optimization of the process flowsheet through computer modelling; investigation of engineering aspects of the process including corrosion, safety, and NO/sub x/ generation; and an economic comparison to conventional cryogenic practice. All objectives were satisfactorily achieved except for continuous operation of the pilot plant, and the modifications necessary to achieve that have been identified. Economically the Moltox process shows a substantial advantage over large scale cryogenic plants which are powered by fuel vice electricity.

  3. Cryogenic methane separation/catalytic hydrogasification process analysis. Final report

    SciTech Connect

    Cassano, A.A.; Hilton, M.F.; Li, T.C.; Tsao, T.R.

    1980-02-14

    The objective of this program was to recommend the most attractive combinations of acid gas removal methane separation systems for the Exxon Catalytic Coal Gasification (CCG) and the Rockwell Hydrogasification process currently undergoing development supported by DOE. The program was comprised of the following tasks. Screening to define the most promising integration scheme for each gasification process; development of a process flowsheet, heat and material balance, P and ID, equipment specification, utility summary, and plot plan for the process combination selected; and preparation of detailed economic and final report. The results of the study are documented in this report. The evaluations were performed using data supplied by the prime coal gasification contractors and the vendors of proprietary acid gas removal processes. This information, combined with Air Products' in-house capabilities in acid gas and cryogenic separation processses, was used to develop process designs and cost estimates for each integrated system. The design based and economic criteria employed in the study are described.

  4. Hydrogen-methane separation processes and related phenomena. [112 references

    SciTech Connect

    Saunders, J.T.; Wang, S.S.; Yang, R.T.

    1981-01-01

    A thorough and up-dated literature survey has been conducted on processes for separating hydrogen and methane. This was done in conjunction with our work of developing a more energy-efficient and lower-cost process based on cyclic, fixed-bed processes using coal chars as the sorbents. Although the review has covered all hydrocarbon separation processes, the focuses were on physical adsorption phenomena and theories (for both single and mixed gases), surface and pore characteristics of coals and heat-treated coals, and the continuous or semi-continuous chromatographic separation methods. There has been a sharply increasing interest in the past 10 to 15 years in developing processes for hydrocarbon separation based on adsorption/desorption; this is particularly true since the energy costs became increasingly higher recently. The rigorous work on competitive adsorption and on the cyclic (including parametric pumping) processes has all been done in the past 13 years. On the other hand, it is disappointing to find the absence of knowledge on adsorption on coal chars and the lack of it on adsorption on raw coals as well.

  5. 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.

  6. 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.

  7. 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.

  8. STRONTIUM & TRANSURANIC (TRU) SEPARATION PROCESS IN THE DOUBLE SHELL TANK (DST) SYSTEM

    SciTech Connect

    JOHNSON; SWANSON; BOECHLER

    2005-06-10

    The supernatants stored in tanks 241-AN-102 (AN-102) and 241-AN-107 (AN-107) contain soluble strontium-90 ({sup 90}Sr) and transuranic (TRU) elements that require removal prior to vitrification to comply with the Waste Treatment and Immobilization Plant (WTP) immobilized low-activity waste (ILAW) specification and with the 1997 agreement with the Nuclear Regulatory Commission on incidental waste. A precipitation process has been developed and tested with tank waste samples and simulants using strontium nitrate (Sr(NO{sub 3}){sub 2}) and sodium permanganate (NaMnO{sub 4}) to separate {sup 90}Sr and TRU from these wastes. This report evaluates removing Sr/TRU from AN-102 and AN-107 supernates in the DST system before delivery to the WTP. The in-tank precipitation is a direct alternative to the baseline WTP process, using the same chemical separations. Implementing the Sr/TRU separation in the DST system beginning in 2012 provides {approx}6 month schedule advantage to the overall mission, without impacting the mission end date or planned SST retrievals.

  9. 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.

  10. Calcium phosphate precipitation in a SBR operated for EBPR: interactions with the biological process.

    PubMed

    Barat, R; Montoya, T; Borras, L; Ferrer, J; Seco, A

    2008-01-01

    The aim of this paper is to study the precipitation process in a sequencing batch reactor (SBR) operated for EBPR (enhanced biological phosphorus removal) and the possible effects of this phosphorus precipitation in the biological process. Four experiments were carried out under different influent calcium concentration. The experimental results and the equilibrium study, based on the Saturation Index calculation, confirm that the process controlling the calcium behaviour in a SBR operated for EBPR is the calcium phosphate precipitation. This precipitation takes place at two stages initially precipitation of the ACP and later crystallization of HAP. Also the accumulation of phosphorus precipitated was observed when the influent Ca concentration was increased. In all the experiments the influent wastewater ratio P/COD was kept constant. It has been observed that at high Ca concentration the amount of poly-P granules decrease, decreasing the ratio between phosphate release and acetate uptake (P(rel)/Ac(uptake)). Changes on PAO and GAO populations during the experimental period were ruled out by means of methilene blue stains for poly-P detection. These results confirmed the phosphate precipitation as a process that can affect to the PAO metabolism and the EBPR performance.

  11. 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.

  12. 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.

  13. Equilibrium theory-based analysis of nonlinear waves in separation processes.

    PubMed

    Mazzotti, Marco; Rajendran, Arvind

    2013-01-01

    Different areas of engineering, particularly separation process technology, deal with one-dimensional, nonstationary processes that under reasonable assumptions, namely negligible dispersion effects and transport resistances, are described by mathematical models consisting of systems of first-order partial differential equations. Their behavior is characterized by continuous or discontinuous composition (or thermal) fronts that propagate along the separation unit. The equilibrium theory (i.e., the approach discussed here to determine the solution to these model equations) predicts this with remarkable accuracy, despite the simplifications and assumptions. Interesting applications are in adsorption, chromatography and ion-exchange, distillation, gas injection, heat storage, sedimentation, precipitation, and dissolution waves. We show how mathematics can enlighten the engineering aspects, and we guide the researcher not only to reach a synthetic understanding of properties of fundamental and applicative interest but also to discover new, unexpected, and fascinating phenomena. The tools presented here are useful to teachers, researchers, and practitioners alike.

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

    PubMed Central

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

    2015-01-01

    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 using 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 E. 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 to isolate 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. PMID:26416692

  15. 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.

  16. 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.

  17. Membranes: Separation and drying processes: Technical briefing report, technology transfer

    SciTech Connect

    Not Available

    1987-09-01

    Membrane technology now being developed for separation and drying applications will save energy in industrial processes, both by reducing the amount of energy used and by recovering energy that would normally be lost. A new membrane separation process that is projected for use in the corn sweetener industry could preconcentrate waste water streams, reducing the need for conventional evaporation. Net energy savings may be as much as 50%. A membrane system proposed for drying applications could be combined with vapor recompression to recover energy that is normally lost when water vapor in dryer exhaust streams is vented to the atmosphere. Preliminary tests indicate this membrane process may recover 30% of the energy contained in the latent heat of the water vapor. Under the sponsorship of the US Department of Energy's Office of Industrial Programs, Bend Research, Inc., of Bend, Oregon, investigated the technical and economic feasibility of these two membrane processes. 9 refs.

  18. Membrane device and process for mass exchange, separation, and filtration

    DOEpatents

    Liu, Wei; Canfield, Nathan L.

    2016-11-15

    A membrane device and processes for fabrication and for using are disclosed. The membrane device may include a number of porous metal membranes that provide a high membrane surface area per unit volume. The membrane device provides various operation modes that enhance throughput and selectivity for mass exchange, mass transfer, separation, and/or filtration applications between feed flow streams and permeate flow streams.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. Coal gasification process wastewater reusability: separation of organics by membranes

    SciTech Connect

    Bhattacharyya, D.; Kermode, R.I.; Dickinson, R.L.

    1983-02-01

    The developing coal-gasification technologies generate gaseous process streams laden with water-soluble species such as H/sub 2/S, NH/sub 3/, HCN, phenols, cresols etc. The primary raw gas clean-up (gas quenching) results in large volumes of highly contaminated wastewaters. The development of a membrane separation process for the removal of selected organics, salts, and scale-forming compounds from stripped coal-conversion process wastewaters, will minimise surface-water pollution and decrease water consumption by permeate recycling. The recent industrial development of non-cellulosic thin-film composite membranes has provided membranes with high salt and low molecular weight organic separation characteristics and insignificant compaction problems. The low pressure membranes (used for brackish water) have definite advantages in terms of energy saving and lower capital cost. The composite membranes perform better than cellulose-acetate membranes. 24 references.

  7. Coal preparation process using true-heavy-liquid separation

    SciTech Connect

    Baltich, L.K.; Malhotra, D.

    1990-12-20

    The Pittsburgh Energy Technology Center (PETC) is supporting work to develop advanced fine-coal cleaning processes including the exploitation of differences in specific gravity through the use of heavy-liquid media in hydrocyclones. The true-heavy-liquid media used for this program are solutions of sulfuric acid (H{sub 2}SO{sub 4}) and water. This concept takes advantage of the miscibility of the acid water to produce a range of heavy liquids up to a specific gravity of 1.84 for pure sulfuric acid. The main objective of this research program was to develop a true-heavy-liquid separation process to clean ultrafine coal using smelter-guide sulfuric acid. Three bituminous coals and one subbituminous coal were selected for testing. In general, single-stage true-heavy-liquid hydrocyclone process demonstrated similar performance characteristics to heavy-media separation processes under study by other investigators. True-heavy-liquid media has the advantage of allowing additional separation steps at other specific gravities for cleaning and scavenging without the introduction of another heavy liquid to the flowsheet. In addition, sulfuric acid is inorganic and can be neutralized and disposed of without the toxicity problems associated with the other type of heavy liquids under consideration. Preliminary economics analysis indicates that the cost for sulfuric acid makeup to the process may be prohibitive. 4 refs., 11 figs., 61 tabs.

  8. Sound Source Separation with Two Spectrograms by Image Processing

    NASA Astrophysics Data System (ADS)

    Higuchi, Hiroaki; Asahi, Kensaku; Sagawa, Yuji; Sugie, Noboru

    We propose a method for separating speeches using two spectrograms. First, two spectrograms are generated from voices recorded with a pair of microphones. The onsets and the offsets of the frequency components are extracted as the features using image processing techniques. Then the correspondences of the features between the spectrograms are determined and the intermicrophone time differences are calculated. Each of frequency components with the common onset/offset occurrences and time difference are grouped together as originating one of the speech signals. A set of band-pass filters are generated corresponding to each group of frequency components. Finally, each of the separated speech signals is extracted by applying the set of band-pass filters to the voice signal recorded by a microphone. Experiments were conducted with the mixture of a male speech sound and a female speech sound consisting of Japanese vowel and contain consonant. The evaluation results demonstrated that the separation was done reasonably well with the proposed method.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Potential Applications of Zeolite Membranes in Reaction Coupling Separation Processes

    PubMed Central

    Daramola, Michael O.; Aransiola, Elizabeth F.; Ojumu, Tunde V.

    2012-01-01

    Future production of chemicals (e.g., fine and specialty chemicals) in industry is faced with the challenge of limited material and energy resources. However, process intensification might play a significant role in alleviating this problem. A vision of process intensification through multifunctional reactors has stimulated research on membrane-based reactive separation processes, in which membrane separation and catalytic reaction occur simultaneously in one unit. These processes are rather attractive applications because they are potentially compact, less capital intensive, and have lower processing costs than traditional processes. Therefore this review discusses the progress and potential applications that have occurred in the field of zeolite membrane reactors during the last few years. The aim of this article is to update researchers in the field of process intensification and also provoke their thoughts on further research efforts to explore and exploit the potential applications of zeolite membrane reactors in industry. Further evaluation of this technology for industrial acceptability is essential in this regard. Therefore, studies such as techno-economical feasibility, optimization and scale-up are of the utmost importance.

  14. 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.

  15. 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.

  16. Process for separating aggressive gases from gas mixtures

    SciTech Connect

    Graham, T.E.

    1984-03-06

    A process for separating large percentages of aggressive gases such as carbon dioxide from low temperature gas mixtures wherein the gas mixture is passed through a plurality of treatment zones in series. In each treatment zone the gas mixture is first compressed to a pressure such that the partial pressure of the carbon dioxide is not greater than the critical carbon dioxide partial pressure and the compressed gas mixture is then brought into contact with a membrane more permeable to carbon dioxide than other gases of the mixture such that carbon dioxide permeates the membrane to the other side thereof. The gas mixture is maintained in contact with the membrane a sufficient time to lower the partial pressure of the carbon dioxide in the non-permeated gas mixture to less than about 40 percent of said critical carbon dioxide partial pressure. The process is especially useful for separating carbon dioxide from methane and other gases.

  17. Coalification process waste water reusability: separation of organics by membranes

    SciTech Connect

    Bhattacharyya, D.; Kermode, R.I.; Dickinson, R.L.

    1983-02-01

    The overall objective of this investigation is to provide a critical evaluation of the current information concerning coal-gasification wastewaters and to establish experimentally the extent of separation of phenolics and polynuclear aromatic hydrocarbons (from single and multi-solute synthetic systems) by low-and high-pressure composite membranes. The compounds selected for experimental investigation were: phenol, O-cresol, 2,3-dimethylphenol, catechol, resorcinol, 2-naphthol, naphthalene, and indole. The development of membrane separation processes is gaining considerable importance because of the feasibility of simultaneous removal of organics and inorganic dissolved solids. Cellulose-acetate membranes developed for desalination processes show no rejection of phenolics; however, recently developed thin-film, noncellulosic composite membranes (even at low-pressure operation) may be useful in gasification wastewater reuse schemes. 24 references, 11 figures, 5 tables.

  18. Role of pH controlled DNA secondary structures in the reversible dispersion/precipitation and separation of metallic and semiconducting single-walled carbon nanotubes.

    PubMed

    Maji, Basudeb; Samanta, Suman K; Bhattacharya, Santanu

    2014-04-07

    Single-stranded DNA (ss-DNA) oligomers (dA20, d[(C3TA2)3C3] or dT20) are able to disperse single-walled carbon nanotubes (SWNTs) in water at pH 7 through non-covalent wrapping on the nanotube surface. At lower pH, an alteration of the DNA secondary structure leads to precipitation of the SWNTs from the dispersion. The structural change of dA20 takes place from the single-stranded to the A-motif form at pH 3.5 while in case of d[(C3TA2)3C3] the change occurs from the single-stranded to the i-motif form at pH 5. Due to this structural change, the DNA is no longer able to bind the nanotube and hence the SWNT precipitates from its well-dispersed state. However, this could be reversed on restoring the pH to 7, where the DNA again relaxes in the single-stranded form. In this way the dispersion and precipitation process could be repeated over and over again. Variable temperature UV-Vis-NIR and CD spectroscopy studies showed that the DNA-SWNT complexes were thermally stable even at ∼90 °C at pH 7. Broadband NIR laser (1064 nm) irradiation also demonstrated the stability of the DNA-SWNT complex against local heating introduced through excitation of the carbon nanotubes. Electrophoretic mobility shift assay confirmed the formation of a stable DNA-SWNT complex at pH 7 and also the generation of DNA secondary structures (A/i-motif) upon acidification. The interactions of ss-DNA with SWNTs cause debundling of the nanotubes from its assembly. Selective affinity of the semiconducting SWNTs towards DNA than the metallic ones enables separation of the two as evident from spectroscopic as well as electrical conductivity studies.

  19. 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.

  20. 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.

  1. PRECP: PRocessing of Emissions by Clouds and Precipitation. The Department of Energy's program on the nonlinearity of acid precipitation processes. Summary of FY 1984-1985 Operational Plan

    SciTech Connect

    Michael, P.

    1984-05-01

    This report presents a summary of the FY 1984-1985 Operational Plan for the US Department of Energy's Program on the PRocessing of Emissions by Clouds and Precipitation (PRECP). Activities scheduled through 1985 are spelled out in some detail; the FY 1986 activities are sketched in somewhat less detail; and the plans for beyond FY 1986 are outlined in rather general terms. The full Operational Plan will be the third report in this series; the first report was the Preliminary Program Plan, which bore the title Nonlinearity of Acid Precipitation Processes (Michael, 1983). The objective and strategy of this project can be stated as follows: to determine how the wet deposition of acidic and other pollutants depends upon inputs to individual storms, by understanding the chemical and physical PRocessing of Emissions by Clouds and Precipitation (PRECP), through analysis of appropriate data, model development and testing, and laboratory and field studies, and for applications in the definition of the relationships between pollutant releases and subsequent deposition. 2 references, 4 figures, 5 tables.

  2. Contributions of TRMM to Our Understanding of Precipitation Processes and Climate Variability

    NASA Technical Reports Server (NTRS)

    Adler, Robert F.

    2005-01-01

    The Tropical Rainfall Measuring Mission (TRMM), a joint U.S./Japan effort, has completed seven and a half years in orbit. This successful research mission studying precipitation processes and climatology has also become a key element in the routine monitoring of global precipitation. The package of rain measuring instrumentation, including the first rain radar and microwave radiometer combination in space, continues to function perfectly, and the satellite has the capability to operate for a number of additional years, providing a unique, long-term record of global tropical precipitation characteristics. A summary of research highlights will be presented covering topics ranging over climate analysis, improving forecasts, and storm and precipitation processes. A focus of the talk will be the important role of TRMM data in multi-satellite precipitation analyses at fine time scales and in improving our understanding of the validity of climate-scale variations through comparison with, and eventual improvement of, the GEWEX Global Precipitation Climatology Project (GPCP) 25-year data set.

  3. 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%.

  4. 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.

  5. 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.

  6. Mathematical Model of Nonstationary Separation Processes Proceeding in the Cascade of Gas Centrifuges in the Process of Separation of Multicomponent Isotope Mixtures

    NASA Astrophysics Data System (ADS)

    Orlov, A. A.; Ushakov, A. A.; Sovach, V. P.

    2017-03-01

    We have developed and realized on software a mathematical model of the nonstationary separation processes proceeding in the cascades of gas centrifuges in the process of separation of multicomponent isotope mixtures. With the use of this model the parameters of the separation process of germanium isotopes have been calculated. It has been shown that the model adequately describes the nonstationary processes in the cascade and is suitable for calculating their parameters in the process of separation of multicomponent isotope mixtures.

  7. 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)

  8. Post-processing Seasonal Precipitation Forecasts via Integrating Climate Indices and the Analog Approach

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Zhang, Y.; Wood, A.; Lee, H. S.; Wu, L.; Schaake, J. C.

    2016-12-01

    Seasonal precipitation forecasts are a primary driver for seasonal streamflow prediction that is critical for a range of water resources applications, such as reservoir operations and drought management. However, it is well known that seasonal precipitation forecasts from climate models are often biased and also too coarse in spatial resolution for hydrologic applications. Therefore, post-processing procedures such as downscaling and bias correction are often needed. In this presentation, we discuss results from a recent study that applies a two-step methodology to downscale and correct the ensemble mean precipitation forecasts from the Climate Forecast System (CFS). First, CFS forecasts are downscaled and bias corrected using monthly reforecast analogs: we identify past precipitation forecasts that are similar to the current forecast, and then use the finer-scale observational analysis fields from the corresponding dates to represent the post-processed ensemble forecasts. Second, we construct the posterior distribution of forecast precipitation from the post-processed ensemble by integrating climate indices: a correlation analysis is performed to identify dominant climate indices for the study region, which are then used to weight the analysis analogs selected in the first step using a Bayesian approach. The methodology is applied to the California Nevada River Forecast Center (CNRFC) and the Middle Atlantic River Forecast Center (MARFC) regions for 1982-2015, using the North American Land Data Assimilation System (NLDAS-2) precipitation as the analysis. The results from cross validation show that the post-processed CFS precipitation forecast are considerably more skillful than the raw CFS with the analog approach only. Integrating climate indices can further improve the skill if the number of ensemble members considered is large enough; however, the improvement is generally limited to the first couple of months when compared against climatology. Impacts of

  9. 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

    2016-10-02

    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.

  10. 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.

  11. FAHP ranking and selection of pretreatment module for membrane separation processes in textile cluster.

    PubMed

    Manekar, Pravin; Nandy, Tapas; Sargaonkar, Abha; Rathi, Barkha; Karthik, Manikavasagam

    2011-01-01

    Recent development in membrane manufacturing and extensive application of membranes in effluent treatment has opened up a new water resource. The effluent pretreatment module plays a critical role in membrane performance. Appropriate selection of conventional and advanced pretreatment modules in membrane separation processes (MSP) is significant to the success of zero effluent discharge (ZED). This study addresses performance assessment of eight conventional and advanced pretreatment modules implemented for wastewater management in a textile cluster in South India. The comparative pollutant reduction, capital, operation and maintenance (OM) cost of pretreatment modules are discussed. The ranking and interdependence of the pretreatment modules were analyzed through fuzzy analytical hierarchy process (FAHP) with MATLAB software. The pretreatment module IV ranked third with a composite weight of 15.46%. The integrated study of performance assessment and FAHP resulted in an optimum pretreatment module IV comprising the sequence of chemical precipitation, bio-oxidation processes (activated sludge processes) followed by chemical precipitation, to achieve the ZED. This study provides a techno-economically feasible solution for selection of an effective pretreatment module for MSP in the textile cluster.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Separate Evaluation of the Kinetics of Carbide Precipitation Occurring at the Interface of Preexisting Particles and Within the Austenitic Matrix in a Microalloyed Steel

    NASA Astrophysics Data System (ADS)

    Jung, Jae-Gil; Shin, Eunjoo; Lee, Young-Kook

    2017-01-01

    The isothermal kinetics of carbide precipitation occurring at the interface of preexisting (Ti,Nb)(N,C) particles and within the deformed γ-austenite matrix were separately evaluated using a Nb-Ti-V microalloyed steel through small-angle neutron scattering and transmission electron microscopy. While the specimen was isothermally held after deformation at 1223 K (950 °C), (Nb,Ti)(C,N) particles were precipitated at the interface of coarse (Ti,Nb)(N,C) particles preexisting in the recrystallized γ matrix. This resulted in a single size distribution curve, which was converted from the measured magnetic scattering cross section. However, during isothermal holding after deformation at 1123 K (850 °C), fine (Nb,Ti,V)(C,N) particles formed mainly within the deformed γ matrix, although some of them were precipitated at the interface of preexisting coarse (Ti,Nb)(N,C) particles. Accordingly, the specimens held at 1123 K (850 °C) exhibited double size distribution curves. The separate evaluation between matrix and interface precipitation kinetics was successfully performed using the size distribution curves due to the difference in particle size according to the nucleation site. The reliability of carbide precipitation kinetics was confirmed by comparing the measured ratio between magnetic and nuclear scattering cross sections with the ratio calculated based on the measured chemical composition of precipitates.

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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)

  3. 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.

  4. 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.

  5. 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.

  6. Cryogenic methane separation/catalytic hydrogasification process analysis. Quarterly report

    SciTech Connect

    Klosek, J.

    1981-02-13

    The objective of this coordinated research program is to obtain the most attractive combinations of acid gas removal, methane separation for the Exxon Catalytic Coal Gasification (CCG) and the Rockwell/Cities Service Hydrogasification processes. The program is divided into nine subtasks with each subtask studying the effect of variation of a key design parameter on the treatment cost of the SNG produced. Progress reports of 8 subtasks are presented. The following are some of the highlights. Subtask 1 - Heat and material balance and equipment sizing was completed for the cryogenic methane separation. The overall material balance is presented in a table. Subtask 2 - Preliminary designs for MEA and DEA gas removal systems were established. Subtasks 3 to 5 - Economic evaluation is in proress. Subtask 6 - The SNG product compressor train was simulated for the case where sufficient SNG fuel is withdrawn from the product compressors to fire the dryer reactivation heater. Subtask 7 - Acid gas removal and cryogenic separation equipment was resized to accommodate Exxon's request for a two-train plant design. Subtask 8 - The Benfield and Selexol systems will be evaluated for acid gas removal.

  7. 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.

  8. Vanadium recovery from oil fly ash by leaching, precipitation and solvent extraction processes.

    PubMed

    Navarro, R; Guzman, J; Saucedo, I; Revilla, J; Guibal, E

    2007-01-01

    In order to reduce the environmental impact due to land disposal of oil fly ash from power plants and to valorize this waste material, the removal of vanadium was investigated using leaching processes (acidic and alkaline treatments), followed by a second step of metal recovery from leachates involving either solvent extraction or selective precipitation. Despite a lower leaching efficiency (compared to sulfuric acid), sodium hydroxide was selected for vanadium leaching since it is more selective for vanadium (versus other transition metals). Precipitation was preferred to solvent extraction for the second step in the treatment since: (a) it is more selective; enabling complete recovery of vanadate from the leachate in the form of pure ammonium vanadate; and (b) stripping of the loaded organic phase (in the solvent extraction process) was not efficient. Precipitation was performed in a two-step procedure: (a) aluminum was first precipitated at pH 8; (b) then ammonium chloride was added at pH 5 to bring about vanadium precipitation.

  9. Vanadium recovery from oil fly ash by leaching, precipitation and solvent extraction processes

    SciTech Connect

    Navarro, R.; Guzman, J.; Saucedo, I.; Guibal, E.

    2007-07-01

    In order to reduce the environmental impact due to land disposal of oil fly ash from power plants and to valorize this waste material, the removal of vanadium was investigated using leaching processes (acidic and alkaline treatments), followed by a second step of metal recovery from leachates involving either solvent extraction or selective precipitation. Despite a lower leaching efficiency (compared to sulfuric acid), sodium hydroxide was selected for vanadium leaching since it is more selective for vanadium (versus other transition metals). Precipitation was preferred to solvent extraction for the second step in the treatment since: (a) it is more selective; enabling complete recovery of vanadate from the leachate in the form of pure ammonium vanadate; and (b) stripping of the loaded organic phase (in the solvent extraction process) was not efficient. Precipitation was performed in a two-step procedure: (a) aluminum was first precipitated at pH 8; (b) then ammonium chloride was added at pH 5 to bring about vanadium precipitation.

  10. 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

    2014-11-14

    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.

  11. Optimization of struvite precipitation in synthetic biologically treated swine wastewater--determination of the optimal process parameters.

    PubMed

    Capdevielle, Aurélie; Sýkorová, Eva; Biscans, Béatrice; Béline, Fabrice; Daumer, Marie-Line

    2013-01-15

    A sustainable way to recover phosphorus (P) in swine wastewater involves a preliminary step of P dissolution followed by the separation of particulate organic matter. The next two steps are firstly the precipitation of struvite crystals done by adding a crystallization reagent (magnesia) and secondly the filtration of the crystals. A design of experiments with five process parameters was set up to optimize the size of the struvite crystals in a synthetic swine wastewater. More than 90% of P was recovered as large crystals of struvite in optimal conditions which were: low Mg:Ca ratio (2.25:1), the leading parameter, high N:P ratio (3:1), moderate stirring rate (between 45 and 90 rpm) and low temperature (below 20 °C).These results were obtained despite the presence of a large amount of calcium and using a cheap reactant (MgO). The composition of the precipitates was identified by Raman analysis and solid dissolution. Results showed that amorphous calcium phosphate (ACP) co-precipitated with struvite and that carbonates were incorporated with solid fractions. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. 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.

  13. 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.

  14. 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, ...

  15. 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, ...

  16. Towards an improved ensemble precipitation forecast: A probabilistic post-processing approach

    NASA Astrophysics Data System (ADS)

    Khajehei, Sepideh; Moradkhani, Hamid

    2017-03-01

    Recently, ensemble post-processing (EPP) has become a commonly used approach for reducing the uncertainty in forcing data and hence hydrologic simulation. The procedure was introduced to build ensemble precipitation forecasts based on the statistical relationship between observations and forecasts. More specifically, the approach relies on a transfer function that is developed based on a bivariate joint distribution between the observations and the simulations in the historical period. The transfer function is used to post-process the forecast. In this study, we propose a Bayesian EPP approach based on copula functions (COP-EPP) to improve the reliability of the precipitation ensemble forecast. Evaluation of the copula-based method is carried out by comparing the performance of the generated ensemble precipitation with the outputs from an existing procedure, i.e. mixed type meta-Gaussian distribution. Monthly precipitation from Climate Forecast System Reanalysis (CFS) and gridded observation from Parameter-Elevation Relationships on Independent Slopes Model (PRISM) have been employed to generate the post-processed ensemble precipitation. Deterministic and probabilistic verification frameworks are utilized in order to evaluate the outputs from the proposed technique. Distribution of seasonal precipitation for the generated ensemble from the copula-based technique is compared to the observation and raw forecasts for three sub-basins located in the Western United States. Results show that both techniques are successful in producing reliable and unbiased ensemble forecast, however, the COP-EPP demonstrates considerable improvement in the ensemble forecast in both deterministic and probabilistic verification, in particular in characterizing the extreme events in wet seasons.

  17. IDA: a peptide ligand regulating cell separation processes in Arabidopsis.

    PubMed

    Aalen, Reidunn B; Wildhagen, Mari; Stø, Ida M; Butenko, Melinka A

    2013-12-01

    In contrast to animals, plants continuously produce new organs, such as leaves, flowers, and lateral roots (LRs), and may shed organs that have served their purpose. In the model plant Arabidopsis thaliana the peptide INFLORESCENCE DEFICIENT IN ABSCISSION (IDA) signals through the leucine-rich repeat-receptor-like kinases (LRR-RLKs) HAESA (HAE), and HAESA-LIKE2 (HSL2) to control the abscission of floral organs after pollination. Recent work from other plant species indicates that this signalling system is conserved and could regulate leaf abscission in soybean and tomato. Abscission is a cell separation process involving the breakdown of cell walls between adjacent files of abscission zone (AZ) cells at the base of organs to be shed. The emergence of new lateral root primordia (LRP), initiated deep inside the root under the influence of the phytohormone auxin, is similarly dependent on cell wall dissolution to separate cells in the overlying tissues. It has been shown that this process also requires IDA, HAE, and HSL2. The receptors are redundant in function during floral organ abscission, but during lateral root emergence (LRE) they are differentially involved in regulating cell wall remodelling (CWR) genes. An overview is given here of the similarities and differences of IDA signalling during floral organ abscission and LRE.

  18. Influence of powder metallurgy route on precipitation processes in MgTbNd alloy

    SciTech Connect

    Stulikova, Ivana Smola, Bohumil; Vlach, Martin; Kudrnova, Hana; Piesova, Jaroslava

    2016-02-15

    Solution treated MgTb3Nd2 alloy (nominal composition in wt.%) (ST) and the alloy prepared by hot extrusion of isostatically pressed powder (PM) were isochronally heat treated and studied by electrical resistivity and hardness measurements and by differential scanning calorimetry. Microstructure development was investigated in transmission electron microscopy. Successive precipitation of transient phases in the sequence β″ (D0{sub 19} plates) → β′(cbco) → β{sub 1} (Mg{sub 3}Gd type, fcc) → β (Mg{sub 5}Gd type, fcc) known from the ST alloy was identified also in the PM alloy. The early precipitation stage (D0{sub 19} clusters) revealed in the ST alloy as well as precipitation of equilibrium β{sub e} phase Mg{sub 41}(Tb,Nd){sub 5} manifest themselves only slightly in the PM alloy. Powder metallurgy route does not change the values of activation energies but shifts the temperature ranges of these processes. Vickers hardness of the as prepared state is higher in the PM alloy and is very resistant against the heat treatment up to 510 °C. Contrary to the ST alloy precipitation due to isochronal annealing does not lead to pronounced hardness changes in the PM alloy. - Highlights: • Powder metallurgy (PM) does not change precipitation sequence in MgTbNd alloy. • Temperature ranges of transient phase precipitations are shifted in PM alloy. • Hardness is resistant against isochronal heat treatment up to 510 °C in the PM alloy. • PM procedure does not change activation energies of precipitation.

  19. Recovery of residual soluble protein by two-step precipitation process with concomitant COD reduction from the yeast-cultivated cheese whey.

    PubMed

    Yadav, J S S; Yan, S; More, T T; Tyagi, R D; Surampalli, R Y

    2014-09-01

    The present study was conducted to recover the residual soluble protein after cultivation of yeast (K. marxianus) in cheese whey. Cheese whey continuous fermentation with cell recycle system was carried out at 40 °C and pH 3.5. The yeast biomass was separated from the fermented broth by centrifugation and residual soluble protein from fermented whey supernatant was precipitated by heat treatment (at 100 °C, pH 4.5 and 10 min incubation). The maximum soluble protein recovery up to 53 % was achieved at pH 4.5 with 54 % residual COD removal. However, gravity sedimentable precipitates were obtained at pH 3.5 with 47 % protein recovery. Therefore, the reactor (scale up) study was conducted at pH 3.5 with agitation, which resulted in 68 % of residual soluble protein recovery and simultaneously residual COD removal of 62 %. Further precipitation/coagulation of soluble protein was also evaluated using carboxymethylcellulose (CMC) and then two precipitation (thermal followed by CMC precipitation) processes were combined to increase the protein precipitation, which finally reached up to 81 % of total soluble protein recovery from the supernatant. This optimized process could be applied to recover the residual protein left after fermentation of cheese whey without centrifugation.

  20. 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

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

    SciTech Connect

    Franks, Carrie J.; Quach, Anh P.; Birnie, Dunbar P.; Ela, Wendell P.; Saez, Avelino E.; Zelinski, Brian J.; Smith, Harry D.; Smith, Gary Lynn L.

    2004-12-01

    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 waste water 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 hours time. 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. 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. 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.

  4. Centrifugal precipitation chromatography.

    PubMed

    Ito, Yoichiro; Qi, Lin

    2010-01-15

    Centrifugal precipitation chromatography separates analytes according their solubility in ammonium sulfate (AS) solution and other precipitants. The separation column is made from a pair of long spiral channels partitioned with a semipermeable membrane. In a typical separation, concentrated ammonium sulfate is eluted through one channel while water is eluted through the other channel in the opposite direction. This countercurrent process forms an exponential AS concentration gradient through the water channel. Consequently, protein samples injected into the water channel is subjected to a steadily increasing AS concentration and at the critical AS concentration they are precipitated and deposited in the channel bed by the centrifugal force. Then the chromatographic separation is started by gradually reducing the AS concentration in the AS channel which lowers the AS gradient concentration in the water channel. This results in dissolution of deposited proteins which are again precipitated at an advanced critical point as they move through the channel. Consequently, proteins repeat precipitation and dissolution through a long channel and finally eluted out from the column in the order of their solubility in the AS solution. The present method has been successfully applied to a number of analytes including human serum proteins, recombinant ketosteroid isomerase, carotenoid cleavage enzymes, plasmid DNA, polysaccharide, polymerized pigments, PEG-protein conjugates, etc. The method is capable to single out the target species of proteins by affinity ligand or immunoaffinity separation.

  5. Detection of non-stationarity in precipitation extremes using a max-stable process model

    NASA Astrophysics Data System (ADS)

    Westra, S.; Sisson, S.

    2011-12-01

    The question of how extreme precipitation will change under a future climate represents an urgent research problem, not least because of the significant societal impacts that would result from an increase in precipitation-induced flooding. To better constrain future projections, an important line of evidence comes from statistical assessments of change to extreme precipitation in the observational record, as a significant amount of warming since pre-industrial times has already taken place. In this study we address this problem by applying a max-stable process model to evaluate whether extreme precipitation at sub-daily and daily timescales has changed at various locations around Australia. This max-stable process approach, which was developed to simulate spatial fields comprising observations from multiple point locations, significantly increases the precision of a statistical inference compared to standard univariate methods. Applying the technique to a field of annual maxima derived from 30 sub-daily gauges in east Australia from 1965 to 2005, we find a statistically significant increase of 18% for 6-minute rainfall over this period, with smaller increases for longer duration events. We also find an increase of 5.6% and 22.5% per degree of Australian land surface temperature and global sea surface temperature at 6-minute durations, respectively, again with smaller scaling relationships for longer durations. In contrast, limited change could be observed in daily rainfall at most locations, with the exception of a statistically significant decline of 7.4% per degree land surface temperature in southwest Western Australia. These results suggest both the importance of better understanding changes to precipitation at the sub-daily timescale, as well as the need to more precisely simulate temporal variability by accounting for the spatial nature of precipitation in any statistical model.

  6. 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.

  7. 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. Copyright 2010 Elsevier B.V. All rights reserved.

  8. 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%.

  9. 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.

  10. 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.

  11. Ground Motions Induced by Precipitation and Fluvial Processes: An Example from Taiwan

    NASA Astrophysics Data System (ADS)

    Yang, Chu-Fang; Chi, Wu-Cheng; Lai, Ying-Ju

    2016-04-01

    Ground motions can be induced by weather-related processes. Analyzing such signals might help quantify those natural processes. Here, we used continuous seismic, meteorological and stream data to analyze broadband ground motions during heavy precipitation events in Taiwan. We detected long period seismic signals in drainage basins during two meteorological cases: Typhoon Morakot in 2009 and East Asian rainy season in 2012. The amplitudes of the seismic waveform correlate well with the amount of the precipitation and the derivative of water level and discharge in a nearby river. We proposed that these seismic signals were induced by ground tilt induced by the loading from the increased water volume in the nearby river. Furthermore, we used the seismic data to estimate and quantify the strength of precipitation during such events. The seismically derived precipitation correlates well with the observed meteorological data. It shows that the long period seismic data may be used to monitor rainfall in real-time. Next, we will try to test our tilt hypothesis using other independent datasets.

  12. Martian Air Separation for In-Situ Resource Utilization Processes

    NASA Astrophysics Data System (ADS)

    MacArthur, J. R.; Way, J. D.; Baldwin, R. M.; Mason, L. W.

    2002-01-01

    We will introduce the concept of using synthetic organic and inorganic membranes for the separation and purification of carbon dioxide (CO2) from mixtures of gases, such as those found in the Martian atmosphere. The class of applications targeted in this project are known as In Situ Resource Utilization (ISRU). ISRU involves the use of resources present on Mars, such as atmospheric gases, a concept that will dramatically reduce the amount of material that must be transferred from Earth to support a mission. ISRU technologies will provide many of the consumables required for a manned mission, such as rocket propellant, water, oxygen and buffer gases. The Martian atmosphere is primarily CO2, and also contains a few percent nitrogen and argon. Martian CO2 is a principal component of several ISRU processes that may be used in a manned Mars mission. For example, the Sabatier/Electrolysis (SE) process reacts atmospheric CO2 with hydrogen to produce methane (fuel), water, and oxygen. Pure gas and mixed gas permeation tests with CO2, Ar, N2, and O2 were performed over the temperature range 243 K to 295 K with a several candidate membrane materials including rubbery polymers (silicone rubber and PEBAX) and supported faujasite zeolite membranes. In experiments with commercially available silicone rubber membranes, the pure gas CO2 permeance (flux/driving force) increases from 460 GPUs to 655 GPUs as the temperature decreases from 295 K to 243 K. A GPU is a commonly used unit of permeance and is defined as 10-6 cm3(STP)/cm2-s-cm Hg. The ideal carbon dioxide/nitrogen separation factor (ratio of pure gas permeances) increases from 7.5 to 17.5 over the same temperature range. However, in mixed gas experiments, the CO2/N2 separation factor was much lower, increasing from 4.5 to 6 as the temperature decreased from 295 K to 243 K. This difference was attributed to plasticization of the rubbery polymer membrane by CO2.

  13. 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.

  14. 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.; hide

    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

  15. Unusual Atmospheric Processes: Implications for the Unusual Isotope Effect in Precipitation

    NASA Astrophysics Data System (ADS)

    Hurst, S.; Krishnamurthy, R. V.

    2016-12-01

    Several samples associated in particular with thunderstorms collected from Kalamazoo, Michigan reveal oxygen and hydrogen isotope ratios that are not compatible with known thermodynamic fractionation or the so-called Raleigh Distillation Effect. Data gathered from April 2014 to February 2016 can be separated into two categories: (1) samples with expected isotopic values based on previous work, (2) samples with unusually high δ18O and δ2H values. Values as high as 42‰ and 25‰ for δ2H and δ18O respectively are obtained. Recent studies suggest that precipitation produced by deep convection can produce moderately enriched oxygen isotopic values, although no hydrogen values for those precipitations are available. Moreover, no values have been recorded that are as high as some of those presented here. The unusual isotope values cannot be attributed to air mass contributions. It is argued that changes in atmospheric chemistry, most likely induced by lightning associated with thunderstorms are responsible. This is likely since temperatures associated with lightning can reach 40000°K. Several studies have indicated that lightning can significantly impact atmospheric chemistry producing, among other species, ozone and NOx. Atmospheric ozone has enriched isotopic values and likely contributes to enriched Oxygen-18 seen in precipitation. An explanation for enrichment in hydrogen is somewhat elusive, but a likely candidate is ion molecular reactions produced by extremely high temperatures in the corona of lightning.

  16. 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.

  17. 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.

  18. 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.

  19. Atmospheric circulation processes contributing to a multidecadal variation in reconstructed and modeled Indian monsoon precipitation

    NASA Astrophysics Data System (ADS)

    Wu, Qianru; Hu, Qi

    2015-01-01

    analysis of the recently reconstructed gridded May-September total precipitation in the Indian monsoon region for the past half millennium discloses significant variations at multidecadal timescales. Meanwhile, paleo-climate modeling outputs from the National Center for Atmospheric Research Community Climate System Model 4.0 show similar multidecadal variations in the monsoon precipitation. One of those variations at the frequency of 40-50 years per cycle is examined in this study. Major results show that this variation is a product of the processes in that the meridional gradient of the atmospheric enthalpy is strengthened by radiation loss in the high-latitude and polar region. Driven by this gradient and associated baroclinicity in the atmosphere, more heat/energy is generated in the tropical and subtropical (monsoon) region and transported poleward. This transport relaxes the meridional enthalpy gradient and, subsequently, the need for heat production in the monsoon region. The multidecadal timescale of these processes results from atmospheric circulation-radiation interactions and the inefficiency in generation of kinetic energy from the potential energy in the atmosphere to drive the eddies that transport heat poleward. This inefficiency creates a time delay between the meridional gradient of the enthalpy and the poleward transport. The monsoon precipitation variation lags that in the meridional gradient of enthalpy but leads that of the poleward heat transport. This phase relationship, and underlining chasing process by the transport of heat to the need for it driven by the meridional enthalpy gradient, sustains this multidecadal variation. This mechanism suggests that atmospheric circulation processes can contribute to multidecadal timescale variations. Interactions of these processes with other forcing, such as sea surface temperature or solar irradiance anomalies, can result in resonant or suppressed variations in the Indian monsoon precipitation.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. [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.

  6. 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

    2016-12-01

    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.

  7. Reuse of washing effluent containing oxalic acid by a combined precipitation-acidification process.

    PubMed

    Lim, Mihee; Kim, Myoung-Jin

    2013-01-01

    This study aims at evaluating the reuse feasibility of effluent produced by the soil washing of mine tailings with oxalic acid. Alkaline chemicals such as NaOH, Ca(OH)(2), and Na(2)CO(3) are used for the precipitation of arsenic and heavy metals in the effluent containing oxalic acid. All of the target contaminants are removed with very high efficiency (up to 100%) at high pH. The precipitation using NaOH at pH 9 is determined to be the most cost-effective method for the removal of arsenic as well as heavy metals in the effluent. The effluent decontaminated by NaOH is consecutively reused for the soil washing of raw mine tailings, resulting in considerable efficiency. Furthermore, even more arsenic and heavy metals are extracted from raw mine tailings by acidifying the decontaminated effluent under the alkaline condition, compared with direct reuse of the decontaminated effluent. Here, the oxalic acid, which is a weak complex-forming ligand as well as a weak acid, has noticeable effects on both soil washing and effluent treatment by precipitation. It extracts efficiently the contaminants from the mine tailings without adverse change of soil and also makes possible the precipitation of the contaminants in the effluent unlike strong chelating reagent. Reuse of the washing effluent containing oxalic acid would make the existing soil washing process more environment-friendly and cost-effective. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. 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.

  9. 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

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

    NASA Astrophysics Data System (ADS)

    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 (3241/59940) of cells lost in the DMACS is much less than that (22360/59940) 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.

  11. A dynamical process study of intense precipitation events over the East Antarctic ice sheet and Southern Ocean

    NASA Astrophysics Data System (ADS)

    Terpstra, Annick; Gorodetskaya, Irina

    2017-04-01

    Extreme precipitation events over the Antarctic coastal and escarpment zones strongly influences regional accumulation patterns and thereby the Antarctic ice-sheet mass balance. Several recent intense precipitation events in Dronning Maud Land (leading to anomalous regional snow accumulation in 2009 and 2011) were preceded by episodes of intense poleward moisture transport organised in narrow, elongated bands. These so-called atmospheric rivers, linking moisture uptake in tropical regions and the deposition at high-latitudes, provide favourable conditions for intense precipitation events over the ice sheet. However, the poleward extent of such moisture plumes is not always sufficient for precipitation formation over the continent, resulting in precipitation over the ocean thus failing to contribute to the surface mass balance of the Antarctic ice sheet. In this study we compare and contrast moisture transport events resulting in either precipitation over the Southern Ocean at the sea-ice/ice-shelf margin or over the Antarctic continent. Identification of the ocean precipitation cases is based on atmospheric river events during the Antarctic Circumnavigation Expedition (ACE, austral summer 2016-2017). We combine ECMWF products analysis with high-resolution regional numerical simulations using Polar-WRF, to gain insight in factors influencing the ability for moisture to reach the Antarctic ice sheet. In particular we focus on (1) moisture sources for precipitation, separating between the transport of moisture originating from lower-latitudes and local moisture recycling, (2) underlying dynamical mechanism for moisture transport, and (3) the production of precipitation.

  12. 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.

  13. Should we use quantile mapping to post-process seasonal GCM precipitation forecasts?

    NASA Astrophysics Data System (ADS)

    Zhao, Tongtiegang; Schepen, Andrew; Bennett, James; Wang, Qj; Wood, Andy; Robertson, David; Ramos, Maria-Helena

    2017-04-01

    Quantile mapping (QM) - the correction of cumulative distribution functions - has been widely used to correct biases in seasonal ensemble precipitation forecasts from coupled global climate models (GCMs). The literature commonly demonstrates QM's efficacy for bias-correction, particularly in climate change studies. A crucial difference between climate change projections and seasonal GCM forecasts is that seasonal forecasts are synchronous with observations. This opens the possibility for more sophisticated post-processing methods that 1) correct biases but also 2) correct ensemble spread and, crucially, 3) ensure forecasts are at least as skilful as climatology - a property termed 'coherence'. Coherence is a necessary precursor for forecasts to have economic value. Through a case study of precipitation predictions from the Australian POAMA GCM, we show that QM does not guarantee reliable ensemble forecasts, nor can it ensure 'coherent' forecasts. Further, we show that a formal statistical calibration using the Bayesian Joint Probability (BJP) modelling approach ensures unbiased, reliable and coherent forecasts. In choosing a post-processing method for GCM precipitation forecasts, the technical benefits of formal calibration methods over QM have to be weighed against their added complexity. In general, however, we caution against the use of quantile mapping to post-process GCM forecasts and recommend the use of more rigorous methods.

  14. Role of pH controlled DNA secondary structures in the reversible dispersion/precipitation and separation of metallic and semiconducting single-walled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Maji, Basudeb; Samanta, Suman K.; Bhattacharya, Santanu

    2014-03-01

    Single-stranded DNA (ss-DNA) oligomers (dA20, d[(C3TA2)3C3] or dT20) are able to disperse single-walled carbon nanotubes (SWNTs) in water at pH 7 through non-covalent wrapping on the nanotube surface. At lower pH, an alteration of the DNA secondary structure leads to precipitation of the SWNTs from the dispersion. The structural change of dA20 takes place from the single-stranded to the A-motif form at pH 3.5 while in case of d[(C3TA2)3C3] the change occurs from the single-stranded to the i-motif form at pH 5. Due to this structural change, the DNA is no longer able to bind the nanotube and hence the SWNT precipitates from its well-dispersed state. However, this could be reversed on restoring the pH to 7, where the DNA again relaxes in the single-stranded form. In this way the dispersion and precipitation process could be repeated over and over again. Variable temperature UV-Vis-NIR and CD spectroscopy studies showed that the DNA-SWNT complexes were thermally stable even at ~90 °C at pH 7. Broadband NIR laser (1064 nm) irradiation also demonstrated the stability of the DNA-SWNT complex against local heating introduced through excitation of the carbon nanotubes. Electrophoretic mobility shift assay confirmed the formation of a stable DNA-SWNT complex at pH 7 and also the generation of DNA secondary structures (A/i-motif) upon acidification. The interactions of ss-DNA with SWNTs cause debundling of the nanotubes from its assembly. Selective affinity of the semiconducting SWNTs towards DNA than the metallic ones enables separation of the two as evident from spectroscopic as well as electrical conductivity studies.Single-stranded DNA (ss-DNA) oligomers (dA20, d[(C3TA2)3C3] or dT20) are able to disperse single-walled carbon nanotubes (SWNTs) in water at pH 7 through non-covalent wrapping on the nanotube surface. At lower pH, an alteration of the DNA secondary structure leads to precipitation of the SWNTs from the dispersion. The structural change of dA20 takes place

  15. 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

  16. 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

  17. 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.

  18. 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.

  19. Multi-wavelength dual polarisation lidar for monitoring precipitation process in the cloud seeding technique

    NASA Astrophysics Data System (ADS)

    Sudhakar, P.; Sheela, K. Anitha; Ramakrishna Rao, D.; Malladi, Satyanarayana

    2016-05-01

    In recent years weather modification activities are being pursued in many countries through cloud seeding techniques to facilitate the increased and timely precipitation from the clouds. In order to induce and accelerate the precipitation process clouds are artificially seeded with suitable materials like silver iodide, sodium chloride or other hygroscopic materials. The success of cloud seeding can be predicted with confidence if the precipitation process involving aerosol, the ice water balance, water vapor content and size of the seeding material in relation to aerosol in the cloud is monitored in real time and optimized. A project on the enhancement of rain fall through cloud seeding is being implemented jointly with Kerala State Electricity Board Ltd. Trivandrum, Kerala, India at the catchment areas of the reservoir of one of the Hydro electric projects. The dual polarization lidar is being used to monitor and measure the microphysical properties, the extinction coefficient, size distribution and related parameters of the clouds. The lidar makes use of the Mie, Rayleigh and Raman scattering techniques for the various measurement proposed. The measurements with the dual polarization lidar as above are being carried out in real time to obtain the various parameters during cloud seeding operations. In this paper we present the details of the multi-wavelength dual polarization lidar being used and the methodology to monitor the various cloud parameters involved in the precipitation process. The necessary retrieval algorithms for deriving the microphysical properties of clouds, aerosols characteristics and water vapor profiles are incorporated as a software package working under Lab-view for online and off line analysis. Details on the simulation studies and the theoretical model developed in this regard for the optimization of various parameters are discussed.

  20. Integrated separation process for isolation and purification of biosuccinic acid.

    PubMed

    Kurzrock, Tanja; Schallinger, Stefan; Weuster-Botz, Dirk

    2011-01-01

    Biotechnologically produced succinic acid has the potential to displace maleic acid and its uses. Therefore, it is of high interest for the chemical, pharmaceutical, and food industry.In addition to optimized production strains and fermentation processes, an efficient separation of succinic acid from the aqueous fermentation broth is indispensable to compete with the current petrochemical production of succinic acid. Isolation and purification of succinic acid from an Escherichia coli fermentation broth were studied with two amine-based reactive extraction systems: (i) trihexylamine in 1-octanol and (ii) diisooctylamine and dihexylamine in a mixture of 1-octanol and 1-hexanol. Back extraction of succinic acid from the organic phase was carried out using an aqueous trimethylamine solution. The trimethylammonium succinate generated after back extraction was split with an evaporation-based crystallization.The focus was on process integration, for example, reuse of the applied amines for extraction and back extraction. It was shown that the maximum trimethylamine concentration for back extraction should not exceed the stoichiometric amount (2 mol trimethylamine/mol the succinic acid in the organic phase) to ensure maximal extraction yields with the reused organic phase in subsequent extractions. Moreover, mixer-settler extraction and back extraction of succinic acid were scaled up from the milliliter- to the liter-scale making use of liquid–liquid centrifuges. The overall yield was 83.5% of the succinic acid from thefermentation supernatant. The final purity of the succinic acid crystals was 99.5%. Organic phase and amines can easily be recycled and reused. © 2011 American Institute of Chemical Engineers

  1. 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.

  2. Separation of phthalate esters from bio-oil derived from rice husk by a basification-acidification process and column chromatography.

    PubMed

    Zeng, Fanxin; Liu, Wujun; Jiang, Hong; Yu, Han-Qing; Zeng, Raymond J; Guo, Qingxiang

    2011-01-01

    Solid precipitate containing phthalate esters was obtained from rice-husk-derived oil through a basification-acidification process. After separation by column chromatography, the solid precipitate was divided into two mono-component fractions, two bi-component fractions and a tetra-component fraction. The major compounds of the five fractions were all consisted of phthalate esters. Especially, phthalate esters accounted for a proportion higher than 80% in both Fractions I and II. The generation and precipitation mechanisms of phthalate esters were proposed. Phthalate esters were considered to be derived from a series of complicated chemical reactions of small molecules in the biomass pyrolysis process, and precipitated from bio-oil by catalytic hydrolysis and esterification. Copyright © 2010 Elsevier Ltd. All rights reserved.

  3. [Optimization of alcohol precipitation process for extract of Carthamus tinctorius by multiple guidelines grading method].

    PubMed

    Yuan, Jia; Li, Ye-rui; Chen, Yong; Wang, Long-hu; Liu, Xue-song

    2011-01-01

    To investigate the optimal alcohol precipitation parameters for extract of Carthamus tinctorius. The effects of different factors on the transfer rate of hydroxy safflower yellow A (HSYA) was studied via single factor experiments, including the final alcohol concentration of the liquor, the speed of stirring, the initial density of the extract, the temperature and the pH of the liquor. Based on the results of single factor experiments, the final alcohol concentration of the liquor, the speed of stirring, the initial density of the extract and the pH of the liquor were studied by an orthogonal test and a multiple guidelines grading method, and the transfer rate of HSYA, the yield and the purity of extract in the supernatant were used as comprehensive evaluation index. The optimal alcohol precipitation process of Carthamus tinctorius extract was as follows: the final alcohol concentration of the liquor 50%, the speed of stirring 500 r/min, the initial density of the extract 1.15 g/ml and the pH of the liquor 5.0. The proposed alcohol precipitation process is convenient and steady with high transfer rate of HSYA, high yield and purity of extract in the supernatant.

  4. a Numerical Study of Cloud and Precipitation Processes in Mesoscale Rainbands.

    NASA Astrophysics Data System (ADS)

    Rutledge, Steven Allan

    Field studies conducted during the University of Washington's CYCLES PROJECT have investigated the dynamical and microphysical processes operating in mesoscale rainbands within extratropical cyclones. Conceptual models of the cloud and precipitation mechanisms present in the various types of rainbands have been developed. The test these conceptual models, a numerical modeling study was undertaken. The numerical simulations centered on warm-frontal rainbands, characterized by a "seeder-feeder" process, and the convective -like narrow cold-frontal rainband. The warm-frontal rainband simulations were divided into two categories based on the observed vertical motions in the feeder zone. In the first category (TYPE 1), the vertical air motions are typical of those associated with the widespread lifting in the vicinity of warm fronts ((TURN)10 cm s('-1)). In the second category (TYPE 2), the vertical motions are stronger ((TURN)70 cm s('-1)). In the TYPE 1 situation the growth of "seed" ice crystals within the feeder zone occurs through vapor deposition. In the TYPE 2 case, seed ice crystals grow by accreting cloud water. In both cases the seed ice crystals provide the necessary particles for the efficient removal of condensate in the feeder zone. The model simulations for the narrow cold-frontal rainband are also divided into two categories. In the first category (non-embedded case) the narrow cold-frontal rainband is considered to be independent of any surrounding precipitation. In the second case (considered more realistic), the narrow cold-frontal rainband is embedded within a region of stratiform precipitation. In the non-embedded case, graupel develops when frozen raindrops grow rapidly by accreting cloud water within the updraft region. In the embedded case snow particles (originating in the stratiform clouds) are swept into the updraft region and are converted rapidly to graupel through riming. The efficient removal of cloud water by snow particles entering the

  5. Separation of water-soluble polysaccharides from Cyclocarya paliurus by ultrafiltration process.

    PubMed

    Xie, Jian-Hua; Shen, Ming-Yue; Nie, Shao-Ping; Zhao, Qiang; Li, Chang; Xie, Ming-Yong

    2014-01-30

    In this study, ultrafiltration membrane process was employed to separate polysaccharides from Cyclocarya paliurus (Batal.) Iljinskaja (C. paliurus) to simulate industrial production. Meanwhile, the molecular weight distribution of C. paliurus polysaccharides was investigated by gel permeation chromatography. Four fractions were obtained and named as CPPS-A, CPPS-B, CPPS-C and CPPS-D, respectively. CPPS-A and CPPS-B contained approximately 69.5% and 12.7% of polysaccharides, whose molecular weight were in the range of 100-300 kDa and 120 kDa, respectively. CPPS-C was comprised of two polysaccharides with average molecular weight of 40 kDa and 15 kDa. Results showed that ultrafiltration resulted in the removal of parts of small molecule weight polysaccharides, the increase of proportion of high molecule weight ones and the obvious improvement of quality of products. Compared with ethanol precipitation and gel permeation chromatography techniques, ultrafiltration showed many advantages, and also provided theoretical support for industrial manufacturing of C. paliurus polysaccharides in separation.

  6. Separation of lignocellulosic materials by combined processes of pre-hydrolysis and ethanol extraction.

    PubMed

    Liu, Zehua; Fatehi, Pedram; Jahan, M Sarwar; Ni, Yonghao

    2011-01-01

    In this paper, we proposed a new modification for an ethanol-based pulping process, which would consist of the pre-hydrolysis (pre-extraction) of wood chips for removing hemicelluloses; the ethanol extraction of pre-hydrolyzed wood chips for removing lignin; and the post purification of cellulose, leading to the production of pure cellulose. We also experimentally evaluated the separation of hemicelluloses from the pre-hydrolysis liquor (PHL) obtained from a pulp mill. To remove lignin from the PHL, it was acidified to a pH of 2, which resulted in 47% lignin precipitation. The lignin separation from the acidified PHL was further improved via adding polyethylene oxide and poly aluminum chloride or adding ethyl acetate. To recover the hemicelluloses from the acidified PHL, ethanol was added to the acidified PHL with a volumetric ratio of 4 to 1. The isolated lignin and hemicelluloses were characterized by a Fourier transform infrared spectroscopy (FTIR) and a gas permeation chromatography (GPC). Copyright © 2010 Elsevier Ltd. All rights reserved.

  7. Enhanced dissolution of megestrol acetate microcrystals prepared by antisolvent precipitation process using hydrophilic additives.

    PubMed

    Cho, Eunbi; Cho, Wonkyung; Cha, Kwang-Ho; Park, Junsung; Kim, Min-Soo; Kim, Jeong-Soo; Park, Hee Jun; Hwang, Sung-Joo

    2010-08-30

    Microcrystals of megestrol acetate (MA), a poorly water-soluble drug, were successfully prepared using an antisolvent precipitation technique for improving the dissolution rate. The effective hydrophilic polymers and surfactants used were screened for their abilities to produce smaller particle sizes. Raw micronized MA and processed MA microcrystals were ranked by the Student-Newman-Keuls test in order of increasing particle size and SPAN values as follows: processed MA microcrystals in the presence of polymer and surfactant (mean diameter 1048nm)<processed MA microcrystals in the presence of polymer (1654nm)<processed MA microcrystals in the absence of polymer and surfactant (3491nm)Processed MA microcrystals in the presence of polymer and surfactant slightly decreased crystallinity and altered crystal habit and preferred orientation without change in polymorph. In addition, the dissolution properties of the processed MA microcrystals in the presence of polymer and surfactant were significantly enhanced as compared to that of the raw micronized MA. This effect is mainly due to a reduction in particle size resulting in an increased surface area. Therefore, it was concluded that the antisolvent precipitation technique in mild conditions could be a simple and useful technique to prepare poorly water-soluble drug particles with reduction in particle size, a narrow particle size distribution and enhanced dissolution properties. Copyright 2010 Elsevier B.V. All rights reserved.

  8. Characterization of nanocrystalline (Th 1- xCe x)O y powders synthesized by co-precipitation process

    NASA Astrophysics Data System (ADS)

    Yildiz, Ö.

    2007-06-01

    Nanocrystalline thoria-ceria (Th 1- xCe x)O y powders in a ratio of x = 0.05-0.5 mol% were prepared by a co-precipitation process, which employs thorium and cerium nitrate as thorium and cerium source material, deionized water as solvent and ammonia gas as precipitant. Cerium was used as a simulator for plutonium and the other actinides with a +4 valency. After co-precipitation the aqueous (Th 1- xCe x)(OH) y · nH 2O cakes had been dried at 110 °C, these powders were separately milled in acetone, carbon tetrachloride, n-dodecane, isopropanol and water before and/or after calcination at different temperatures (300-600 °C). DTA-TG, XRD, TEM and BET analyses were performed to characterize the produced powders. Characterization results revealed that the materials were not crystallized, even the temperature reached up to 600 °C. The crystallization of (Th 1- xCe x)O y began at about 600 °C. The crystal growth took place between the temperatures 600 °C and 1200 °C. The powders have a range average crystallite sizes from 5 to 115 nm, with a specific surface area from 6 to 111 m 2/g depending on the calcination temperature and Ce mol%. In this way the crystallized nano (Th 1- xCe x)O 2 powder with a higher specific surface area is able to be produced to obtain the pellets in very high density.

  9. The large-scale process of microbial carbonate precipitation for nickel remediation from an industrial soil.

    PubMed

    Zhu, Xuejiao; Li, Weila; Zhan, Lu; Huang, Minsheng; Zhang, Qiuzhuo; Achal, Varenyam

    2016-12-01

    Microbial carbonate precipitation is known as an efficient process for the remediation of heavy metals from contaminated soils. In the present study, a urease positive bacterial isolate, identified as Bacillus cereus NS4 through 16S rDNA sequencing, was utilized on a large scale to remove nickel from industrial soil contaminated by the battery industry. The soil was highly contaminated with an initial total nickel concentration of approximately 900 mg kg(-1). The soluble-exchangeable fraction was reduced to 38 mg kg(-1) after treatment. The primary objective of metal stabilization was achieved by reducing the bioavailability through immobilizing the nickel in the urease-driven carbonate precipitation. The nickel removal in the soils contributed to the transformation of nickel from mobile species into stable biominerals identified as calcite, vaterite, aragonite and nickelous carbonate when analyzed under XRD. It was proven that during precipitation of calcite, Ni(2+) with an ion radius close to Ca(2+) was incorporated into the CaCO3 crystal. The biominerals were also characterized by using SEM-EDS to observe the crystal shape and Raman-FTIR spectroscopy to predict responsible bonding during bioremediation with respect to Ni immobilization. The electronic structure and chemical-state information of the detected elements during MICP bioremediation process was studied by XPS. This is the first study in which microbial carbonate precipitation was used for the large-scale remediation of metal-contaminated industrial soil. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Indirect Abuse Involving Children During the Separation Process.

    PubMed

    Hayes, Brittany E

    2015-07-27

    Separation is believed to be an antidote to risk abusers pose to their partners and children and underlines many interventions in family, juvenile, and criminal court proceedings. Countering this belief is the claim that many abusers respond to the felt loss of power and control occasioned by separation by changing or escalating abusive tactics. This study complements research on post-separation by asking whether separation is associated with an increase in threats of indirect abuse, which relies on third parties to manipulate the victim. Children, and threats made against them, can be used as a proxy to control or intimidate the victim. Using data from the Chicago Women Health Risk Study (N = 339), the current study examined whether mothers who were separated were at greater risk of abuse through threats against the children when compared with mothers who were still in a relationship with their abuser. Results indicated that separated mothers were four times more likely to report threats to take and threats to harm the children, Exp(B) = 4.05, p < .05; Exp(B) = 3.93, p < .05, than non-separated mothers. Findings can be used to inform child custody procedures and the design of Family Justice Centers.

  11. The Separation-Individuation Process and Developmental Disabilities.

    ERIC Educational Resources Information Center

    Mordock, John B.

    1979-01-01

    The four stages of separation individuation--symbosis, differentiation, practice, and rapprochement--are examined and the early stages of childhood development are discussed in relation to the education of developmentally disabled children. (PHR)

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Processes involving selective precipitation for the recovery of purified pectins from mango peel.

    PubMed

    Nagel, Andreas; Winkler, Carina; Carle, Reinhold; Endress, Hans-Ulrich; Rentschler, Christine; Neidhart, Sybille

    2017-10-15

    Three methods for the recovery of purified pectins from directly dried mango peel were developed, using selective precipitation of mango pectin in propan-2-ol (IPA) of adequate volume concentrations for purification. Yields, composition, macromolecular and gelling properties of the resultant pectins were compared. Effluent analyses proved postextractive removal of fruit exudate arabinogalactans. The recovery processes involved (A) washing of raw-pectin powder in IPA of defined volume concentration, (B) fractional alcoholic precipitation of dissolved raw pectin, or (C) selective pectin precipitation from the hot-acid extract of mango peel in adequately diluted IPA. High galacturonic acid contents (≥ 721g/kg) and intrinsic viscosities (≥ 320mL/g) enabled ∼2.2-fold gelling capacities compared to raw mango pectin, which resulted from the standard procedure mimicking industrial pectin recovery from established sources. Removal of the predominant impurities (coextractable exudate arabinogalactans, ash) diminished the yields to ∼49% of the raw-pectin yield. Technical feasibility of the proposed procedures was discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. 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.

  18. 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.

  19. [Design space approach to optimize first ethanol precipitation process of Dangshen].

    PubMed

    Xu, Zhi-lin; Huang, Wen-hua; Gong, Xing-chu; Ye, Tian-tian; Qu, Hai-bin; Song, Yan-gang; Hu, Dong-lai; Wang, Guo-xiang

    2015-11-01

    Design space approach is applied in this study to enhance the robustness of first ethanol precipitation process of Codonopsis Radix (Dangshen) by optimizing parameters. Total flavonoid recovery, dry matter removal, and pigment removal were defined as the process critical quality attributes (CQAs). Plackett-Burman designed experiments were carried out to find the critical process parameters (CPPs). Dry matter content of concentrated extract (DMCE), mass ratio of ethanol to concentrated extract (E/C ratio) and concentration of ethanol (CEA) were identified as the CPPs. Box-Behnken designed experiments were performed to establish the quantitative models between CPPs and CQAs. Probability based design space was obtained and verified using Monte-Carlo simulation method. According to the verification results, the robustness of first ethanol precipitation process of Dangshen can be guaranteed by operating within the design space parameters. Recommended normal operation space are as follows: dry matter content of concentrated extract of 45.0% - 48.0%, E/C ratio of 2.48-2.80 g x g(-1), and the concentration of ethanol of 92.0% - 92.7%.

  20. 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.

  1. 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.

  2. 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).

  3. 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).

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

    PubMed

    Heinonen, Jari; Kukkonen, Saku; Sainio, Tuomo

    2014-09-05

    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.

  5. 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.

  6. 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; hide

    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.

  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. 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…

  9. 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

  10. 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.

  11. 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.

  12. Quantitative examination of carbide and sulphide precipitates in chemically complex steels processed by direct strip casting

    SciTech Connect

    Dorin, Thomas; Wood, Kathleen; Taylor, Adam; Hodgson, Peter; Stanford, Nicole

    2016-02-15

    A high strength low alloy steel composition has been melted and processed by two different routes: simulated direct strip casting and slow cooled ingot casting. The microstructures were examined with scanning and transmission electron microscopy, atom probe tomography and small angle neutron scattering (SANS). The formation of cementite (Fe{sub 3}C), manganese sulphides (MnS) and niobium carbo-nitrides (Nb(C,N)) was investigated in both casting conditions. The sulphides were found to be significantly refined by the higher cooling rate, and developed an average diameter of only 100 nm for the fast cooled sample, and a diameter too large to be measured with SANS in the slow cooled condition (> 1.1 μm). Slow cooling resulted in the development of classical Nb(C,N) precipitation, with an average diameter of 7.2 nm. However, after rapid cooling both the SANS and atom probe tomography data indicated that the Nb was retained in the matrix as a random solid solution. There was also some evidence that O, N and S are also retained in solid solution in levels not found during conventional processing. - Highlights: • The influence of cooling rate on microstructure is investigated in a HSLA steel. • SANS, TEM and APT are used to characterise the sulphides and Nb(C,N) precipitates. • The slow cooling rate result in the formation of Nb(C,N) precipitates. • The fast cooling rate results in a microstructure supersaturated in Nb, C and N. • The sulphides are 100 nm in the fast cooled sample and > 1 μm in the slow cooled one.

  13. 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

  14. 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...

  15. 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,...

  16. 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...

  17. 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,...

  18. Quality-by-Design (QbD): An integrated process analytical technology (PAT) approach for a dynamic pharmaceutical co-precipitation process characterization and process design space development.

    PubMed

    Wu, Huiquan; White, Maury; Khan, Mansoor A

    2011-02-28

    The aim of this work was to develop an integrated process analytical technology (PAT) approach for a dynamic pharmaceutical co-precipitation process characterization and design space development. A dynamic co-precipitation process by gradually introducing water to the ternary system of naproxen-Eudragit L100-alcohol was monitored at real-time in situ via Lasentec FBRM and PVM. 3D map of count-time-chord length revealed three distinguishable process stages: incubation, transition, and steady-state. The effects of high risk process variables (slurry temperature, stirring rate, and water addition rate) on both derived co-precipitation process rates and final chord-length-distribution were evaluated systematically using a 3(3) full factorial design. Critical process variables were identified via ANOVA for both transition and steady state. General linear models (GLM) were then used for parameter estimation for each critical variable. Clear trends about effects of each critical variable during transition and steady state were found by GLM and were interpreted using fundamental process principles and Nyvlt's transfer model. Neural network models were able to link process variables with response variables at transition and steady state with R(2) of 0.88-0.98. PVM images evidenced nucleation and crystal growth. Contour plots illustrated design space via critical process variables' ranges. It demonstrated the utility of integrated PAT approach for QbD development. Published by Elsevier B.V.

  19. 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.

  20. Chromatographic separation of neodymium isotopes by using chemical exchange process.

    PubMed

    Ismail, I M; Ibrahim, M; Aly, H F; Nomura, M; Fujii, Y

    2011-05-20

    The neodymium isotope effects were investigated in Nd-malate ligand exchange system using the highly porous cation exchange resin SQS-6. The temperature of the chromatographic columns was kept constant at 50°C by temperature controlled water passed through the columns jackets. The separation coefficient of neodymium isotopes, ɛ's, was calculated from the isotopic ratios precisely measured by means of an ICP mass spectrometer equipped with nine collectors as ion detectors. The separation coefficient, ɛ×10(5), were calculated and found to be 1.4, 4.8, 5.4, 10.6, 16.8 and 20.2 for (143)Nd, (144)Nd, (145)Nd, (146)Nd, (148)Nd and (150)Nd, respectively.

  1. 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.

  2. 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.

  3. 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

  4. The Relationship Between Latent Heating, Vertical Velocity, and Precipitation Processes: the Impact of Aerosols on Precipitation in Organized Deep Convective Systems

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo; Li, Xiaowen

    2016-01-01

    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 updraftsdowndrafts in the middlelower 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. A hybrid liquid-phase precipitation (LPP) process in conjunction with membrane distillation (MD) for the treatment of the INEEL sodium-bearing liquid waste.

    PubMed

    Bader, M S H

    2005-05-20

    A novel hybrid system combining liquid-phase precipitation (LPP) and membrane distillation (MD) is integrated for the treatment of the INEEL sodium-bearing liquid waste. The integrated system provides a "full separation" approach that consists of three main processing stages. The first stage is focused on the separation and recovery of nitric acid from the bulk of the waste stream using vacuum membrane distillation (VMD). In the second stage, polyvalent cations (mainly TRU elements and their fission products except cesium along with aluminum and other toxic metals) are separated from the bulk of monovalent anions and cations (dominantly sodium nitrate) by a front-end LPP. In the third stage, MD is used first to concentrate sodium nitrate to near saturation followed by a rear-end LPP to precipitate and separate sodium nitrate along with the remaining minor species from the bulk of the aqueous phase. The LPP-MD hybrid system uses a small amount of an additive and energy to carry out the treatment, addresses multiple critical species, extracts an economic value from some of waste species, generates minimal waste with suitable disposal paths, and offers rapid deployment. As such, the LPP-MD could be a valuable tool for multiple needs across the DOE complex where no effective or economic alternatives are available.

  10. The MAGSORB process for bulk separation of carbon dioxide

    SciTech Connect

    Knight, R.A.; Carty, R.H. ); Duthie, R.G.; Pechtl, P.A. )

    1992-04-01

    The experimental work performed in this program has revealed the impact of formulation procedure on MAGSORB properties, and has shown that the sorbent has adequate potential as a CO{sub 2} sorbent for synthesis gas production. MAGSORB is a highly selective CO{sub 2} sorbent that does not react with other synthesis gas components (H{sub 2}, CO, H{sub 2}O, H{sub 2}S, or NH{sub 3}), nor is its performance adversely affected by these components. A technoeconomic analysis has shown that the integration of MAGSORB into a syngas conditioning train can result in significant capital and operating cost benefits when compared with conventional technology. Several areas of further development are still needed. The laboratory preparation method used in this program may not be optimal in terms of sorbent properties and practicality on a commercial scale. Alternative methods involving co-precipitation or co-crystallization of MgCO{sub 3} and K{sub 2}CO{sub 3} should be investigated. The life-cycle tests have shown that the sorbent as make in this study loses reactivity after absorption/desorption cycling. A fundamental study of surface properties should be made to determine the cause of deactivation. Specific recommendations for future MAGSORB development activities are given.

  11. The Separative Bioreactor: A Continuous Separation Process for the Simultaneous Production and Direct Capture of Organic Acids

    PubMed Central

    Arora, M. B.; Hestekin, J. A.; Snyder, S. W.; St. Martin, E. J.; Lin, Y. J.; Donnelly, M. I.; Millard, C. Sanville

    2007-01-01

    Abstract The replacement of petrochemicals with biobased chemicals requires efficient bioprocesses, biocatalysis, and product recovery. Biocatalysis (e.g., enzyme conversion and fermentation) offers an attractive alternative to chemical processing because biocatalysis utilize renewable feedstocks under benign reaction conditions. One class of chemical products that could be produced in large volumes by biocatalysis is organic acids. However, biocatalytic reactions to produce organic acids typically result in only dilute concentrations of the product because of product inhibition and acidification that drives the reaction pH outside of the optimal range for the biocatalyst. Buffering or neutralization results in formation of the acid salt rather than the acid, which requires further processing to recover the free acid product. To address these barriers to biocatalytic organic acid production, we developed the “separative bioreactor” based on resin wafer electrodeionization, which is an electro-deionization platform that uses resin wafers fabricated from ion exchange resins. The separative bioreactor simultaneously separates the organic acid from the biocatalyst as it is produced, thus it avoids product inhibition enhancing reaction rates. In addition, the separative bioreactor recovers the product in its acid form to avoid neutralization. The instantaneous separation of acid upon formation in the separative bioreactor is one of the first truly one-step systems for producing organic acids. The separative bioreactor was demonstrated with two systems. In the first demonstration, the enzyme glucose fructose oxidoreductase (GFOR) was immobilized in the reactor and later regenerated in situ. GFOR produced gluconic acid (in its acid form) continuously for 7 days with production rates up to 1000 mg/L/hr at >99% product recovery and GFOR reactivity >30mg gluconic acid/mg GFOR/hour. In the second demonstration, the E. coli strain CSM1 produced lactic acid for up to 24

  12. The process of separation in the turbulent friction layer

    NASA Technical Reports Server (NTRS)

    Gruschwitz, E

    1933-01-01

    The separation of the flow which occurs at large angles of attack on the suction side of an airplane wing is attributable to phenomena in the flowing fluid layer adjacent to the surface; the fluid particles slowed up by the friction on the surface can no longer advance against an unduly great pressure rise. It is of vital importance that there exist two types of flow - laminar and turbulent - in the fluid layer flowing in the immediate vicinity of a body. According to Prandtl, by whom the whole theory was developed, we speak in the first case of a laminar boundary layer, in the second, of a turbulent friction layer. (author)

  13. Imaging wet gas separation process by capacitance tomography

    NASA Astrophysics Data System (ADS)

    Yang, Wuqiang; Nguyen, Van T.; Betting, Marco; Chondronasios, Athanasios; Nattras, Steve; Okimoto, Fred; McCann, Hugh

    2002-03-01

    Natural gas from a well contains water and hydrocarbons. It is necessary to separate the liquid components from such gas streams before use. An innovative type of separation facility, called Twister, has been developed for this purpose, and CFD models have been developed to assist in the design of Twister. However, it is difficult to verify the mathematical models directly and experimentally. To investigate the behavior of Twister and to verify the CFD models, a simulator using air and water vapor was set up in the laboratory. This simulator was instrumented with a highly sensitive electrical capacitance tomography (ECT) system based on an HP LCR meter and a purpose-designed multiplexer. Two ECT sensors, each with 8 measurement electrodes, were built taking into consideration the demanding operational conditions, such as sensitivity, temperature, pressure, geometry and location. This paper presents the first experimental results, showing that water droplets distributions in a flowing gas can be visualized using ECT, and the tomography system developed is robust and offers the possibility for further development to field operations.

  14. An innovative antisolvent precipitation process as a promising technique to prepare ultrafine rifampicin particles

    NASA Astrophysics Data System (ADS)

    Viçosa, Alessandra; Letourneau, Jean-Jacques; Espitalier, Fabienne; Inês Ré, Maria

    2012-03-01

    Many existing and new drugs fail to be fully utilized because of their limited bioavailability due to poor solubility in aqueous media (BCS drug classes II and IV). In this work, for accelerating dissolution of this kind of poorly water-soluble drugs, an antisolvent precipitation method that does not require the use of conventional volatile organic solvents is proposed. To demonstrate this technique, ultrafine particles of rifampicin were prepared using a room temperature ionic liquid (1-ethyl 3- methyl imidazolium methyl-phosphonate) as an alternative solvent and a phosphate buffer as an antisolvent. Rifampicin solubility was measured in various solvents (1-ethyl 3-methyl imidazolium methylphosphonate, water and phosphate buffer), showing the RTIL good solvency for the model drug: rifampicin solubility was found to be higher than 90 mg/g in RTIL at 30 °C and lower than 1 mg/g in water at 25 °C. Additionally, it was demonstrated that introduction of rifampicin solution in 1-ethyl 3- methyl imidazolium methyl-phosphonate into the aqueous solution antisolvent can produce particles in the submicron range with or without hydroxypropyl methylcellulose as the stabilizer. The ultrafine particles (280-360 nm) are amorphous with enhanced solubility and faster dissolution rate. To our knowledge, this is the first published work examining the suitability of using RTILs for ultrafine drug nanoparticles preparation by an antisolvent precipitation process.

  15. 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…

  16. Synthesis and photocatalytic performances of BiVO{sub 4} by ammonia co-precipitation process

    SciTech Connect

    Yu Jianqiang Zhang Yan; Kudo, Akihiko

    2009-02-15

    This paper reports the preparation and photocatalytic performance of Bismuth vanadate (BiVO{sub 4}) by a facile and inexpensive approach. An amorphous BiVO{sub 4} was first prepared by a co-precipitation process from aqueous solutions of Bi(NO{sub 3}){sub 3} and NH{sub 4}VO{sub 3} using ammonia. Followed by heating treatment at various temperatures, the amorphous phase converted to crystalline BiVO{sub 4} with a structure between monoclinic and tetragonal scheelite. The crystallization of BiVO{sub 4} occurred at about 523 K, while the nanocrystalline BiVO{sub 4} were formed with a heat-treatment of lower than 673 K. However, when the heat-treatment was carried out at 773 K, the accumulation of nanocrystals to bulk particles was observed. The photocatalytic performances of the materials were investigated by O{sub 2} evolution under visible-light, and MB decomposition under solar simulator. The results demonstrated that the crystalline structure is still the vital factor for the activities of both reactions. However, the crystallinity of BiVO{sub 4} gives a major influence on the activity of O{sub 2} evolution, whereas the surface area, plays an important role for photocatalytic MB decomposition. - Abstract: BiVO{sub 4} was prepared by a co-precipitation process using aqueous ammonia solution, followed by heating treatment at various temperatures. The crystalline structure and crystallization process, and their influences on photocatalytic O{sub 2} evolution and organic pollutants degradation were investigated. It demonstrated that the crystalline structure is still the vital factor for the activities of both reactions. However, the crystallinity of BiVO{sub 4} gives a major influence on the activity of O{sub 2} evolution, whereas the surface area, plays an important role for photocatalytic MB decomposition. Display Omitted.

  17. 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.

  18. 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

  19. Precipitation-enhanced diffusion of nickel in dislocation-free silicon studied by in-diffusion and annealing processes

    NASA Astrophysics Data System (ADS)

    Tanaka, Shuji; Kitagawa, Hajime; Ikari, Tetsuo

    2001-12-01

    To examine the site-exchange mechanism of nickel atoms in dislocation-free silicon, the effect of nickel precipitates on the in-diffusion and annealing rates has been investigated. The variation of the concentration of substitutional nickel atoms with time in these processes follow well the theoretical prediction for the dissociative mechanism. It is suggested that nickel atoms in dislocation-free silicon exchange their sites via the dissociative mechanism, or the dominant point defects mediating the site exchange are vacancies. In-diffusion and annealing processes of nickel atoms are accelerated by the presence of the nickel precipitation, indicating that nickel precipitates, or precipitation-induced lattice defects play a role of sinks and sources of vacancies in the bulk.

  20. 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)

  1. Physico-chemical separation process of nanoparticles in cosmetic formulations

    NASA Astrophysics Data System (ADS)

    Retamal Marín, R. R.; Babick, F.; Stintz, M.

    2017-06-01

    Understanding the world of nanoparticles, especially their interactions with the environment, begins with their correct detection and successive quantification. To achieve this purpose, one needs to perform correctly developed standard operating procedures (SOPs). Furthermore, the study of nanoparticles frequently requires their characterisation in complex media (e.g. in cosmetic formulations). In this study, a set of sample preparation procedures for the detection and extraction of NMs in emulsion-based formulations is proposed and their performance for model and real-life products is discussed. A separation or extraction of lipid phases is achieved by means of organic solvents. The polarity of the lipid phases is decisive for selecting an optimum solvent. The use of the Hansen Solubility Parameters (HSP) may clearly support this decision.

  2. Microfluidic separation process by the Soret effect in biological fluids

    NASA Astrophysics Data System (ADS)

    Martin, Alain; Bou-Ali, M. Mounir; Barrutia, Haritz; Alonso de Mezquia, David

    2011-05-01

    In this article the thermophysical and transport properties of mixtures composed of glucose and sucrose in dimethylsulfoxide (DMSO) are determined. The studied mass concentrations are 5%, 10%, 15%, 20% and 25% of glucose or sucrose in DMSO at an average temperature of 25 °C. The properties studied experimentally are the dynamic viscosity, density, mass and thermal expansion coefficient and thermodiffusion coefficient. The thermogravitational technique in flat configuration is used in order to obtain the thermodiffusion coefficients. Once these properties are known, the work is focused on the numerical study of applying a temperature gradient in microdevices in order to optimize the extraction of DMSO using the CFD Ansys Fluent software. The results show an improvement even of 35% on microfluidic separation techniques that are based on a purely diffusive regime.

  3. 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...

  4. 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.

  5. 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...

  6. 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.

  7. 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.

  8. Cryogenic methane separation/catalytic hydrogasification process analysis. Quarterly report

    SciTech Connect

    Klosek, J.

    1981-05-01

    The objective of this coordinated research program is optimization of the Rockwell/Cities Service Short Residence Time Hydrogasification (SRTH) and the Exxon Catalytic Coal Gasification (CCG) processes in the acid gas removal and cryogenic areas. Progress reports of eight subtasks are presented along with process flowsheets, heat and material balances and economic evaluation, summarized in tables. Each subtask studied the effect of variation of a key design parameter on the treatment cost of the SNG produced.

  9. 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.

  10. Process control measurements in the SRP fuel separations plants

    SciTech Connect

    McKibben, J.M.; Pickett, C.E.; Dickert, H.D.

    1982-02-01

    Programs were started to develop new in-line and at-line analytical techniques. Among the more promising techniques being investigated are: (1) an in-line instrument to analyze for percent tributyl phosphate in process solvent, (2) remote laser optrode techniques (using lazer light transmitted to and from the sample cell via light pipes) for a variety of possible analyses, and (3) sonic techniques for concentration analyses in two component systems. A subcommittee was also formed to investigate state-of-the-technology for process control. The final recommendation was to use a distributed control approach to upgrade the process control sytem. The system selected should be modular, easy to expand, and simple to change control strategies. A distributed system using microprocessorbased controllers would allow installation of the control intelligence near the process, thereby simplifying field wiring. Process information collected and stored in the controllers will be transmitted to operating consoles, via a data highway, for process management and display. The overall program has a number of distinct benefits. There are a number of cost savings that will be realized. Excellent annual return on investment - up to 110% - has been predicted for several of the projects in this program that are already funded. In addition, many of the instrument modifications will improve safety performance and production throughput in the specific ways shown.

  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. Segmentation-free image processing and analysis of precipitate shapes in 2D and 3D

    NASA Astrophysics Data System (ADS)

    Bales, Ben; Pollock, Tresa; Petzold, Linda

    2017-06-01

    Segmentation based image analysis techniques are routinely employed for quantitative analysis of complex microstructures containing two or more phases. The primary advantage of these approaches is that spatial information on the distribution of phases is retained, enabling subjective judgements of the quality of the segmentation and subsequent analysis process. The downside is that computing micrograph segmentations with data from morphologically complex microstructures gathered with error-prone detectors is challenging and, if no special care is taken, the artifacts of the segmentation will make any subsequent analysis and conclusions uncertain. In this paper we demonstrate, using a two phase nickel-base superalloy microstructure as a model system, a new methodology for analysis of precipitate shapes using a segmentation-free approach based on the histogram of oriented gradients feature descriptor, a classic tool in image analysis. The benefits of this methodology for analysis of microstructure in two and three-dimensions are demonstrated.

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

    SciTech Connect

    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.

  14. 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.

  15. Application of the "VARICOL" process to the separation of the isomers of the SB-553261 racemate.

    PubMed

    Ludemann-Hombourger, O; Pigorini, G; Nicoud, R M; Ross, D S; Terfloth, G

    2002-02-15

    A new continuous chromatographic process (VARICOL) has been presented recently. The basic principle of the new VARICOL process consists of an asynchronous shift of the inlet/outlet lines in a multi-column system on a recycle loop. This process has been used to perform the separation of the optical isomers of the SB-553261 racemate. In this paper, we illustrate that for this specific separation, the VARICOL process is more efficient than the well-known SMB process.

  16. 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

  17. Barotropic processes associated with the development of the Mei-yu precipitation system

    NASA Astrophysics Data System (ADS)

    Li, Tingting; Li, Xiaofan

    2016-05-01

    The barotropic processes associated with the development of a precipitation system are investigated through analysis of cloud-resolving model simulations of Mei-yu torrential rainfall events over eastern China in mid-June 2011. During the model integration period, there were three major heavy rainfall events: 9-12, 13-16 and 16-20 June. The kinetic energy is converted from perturbation to mean circulations in the first and second period, whereas it is converted from mean to perturbation circulations in the third period. Further analysis shows that kinetic energy conversion is determined by vertical transport of zonal momentum. Thus, the prognostic equation of vertical transport of zonal momentum is derived, in which its tendency is associated with dynamic, pressure gradient and buoyancy processes. The kinetic energy conversion from perturbation to mean circulations in the first period is mainly associated with the dynamic processes. The kinetic energy conversion from mean to perturbation circulations in the third period is generally related to the pressure gradient processes.

  18. 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.

  19. Development and characterization of a scalable controlled precipitation process to enhance the dissolution of poorly water-soluble drugs.

    PubMed

    Rogers, True L; Gillespie, Ian B; Hitt, James E; Fransen, Kevin L; Crowl, Cindy A; Tucker, Christopher J; Kupperblatt, Gary B; Becker, Joe N; Wilson, Deb L; Todd, Clifford; Broomall, Charles F; Evans, Jonathan C; Elder, Edmund J

    2004-11-01

    Poorly water-soluble compounds are being found with increasing frequency among pharmacologically active new chemical entities, which is a major concern to the pharmaceutical industry. Some particle engineering technologies have been shown to enhance the dissolution of many promising new compounds that perform poorly in formulation and clinical studies (Rogers et. al., Drug Dev Ind Pharm 27:1003-1015). One novel technology, controlled precipitation, shows significant potential for enhancing the dissolution of poorly soluble compounds. In this study, controlled precipitation is introduced; and process variables, such as mixing zone temperature, are investigated. Finally, scale-up of controlled precipitation from milligram or gram to kilogram quantities is demonstrated. Dissolution enhancement capabilities were established using two poorly water-soluble model drugs, danazol and naproxen. Stabilized drug particles from controlled precipitation were compared to milled, physical blend, and bulk drug controls using particle size analysis (Coulter), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), dissolution testing (USP Apparatus 2), and residual solvent analysis. Stabilized nano- and microparticles were produced from controlled precipitation. XRD and SEM analyses confirmed that the drug particles were crystalline. Furthermore, the stabilized particles from controlled precipitation exhibited significantly enhanced dissolution properties. Residual solvent levels were below FDA limits. Controlled precipitation is a viable and scalable technology that can be used to enhance the dissolution of poorly water-soluble pharmaceutical compounds.

  20. Spatiotemporal signal processing for blind separation of multichannel signals

    NASA Astrophysics Data System (ADS)

    Tugnait, Jitendra K.

    1996-06-01

    This paper is concerned with the problem of blind separation of independent signals (sources) from their linear convolutive mixtures. The problem consists of recovering the sources up to shaping filters from the observations of multiple-input multiple-output (MIMO) system output. The various signals are assumed to be linear but not necessarily i.i.d. (independent and identically distributed). The problem is cast into the framework of spatio-temporal equalization and estimation of the matrix impulse response function of MIMO channels (systems). An iterative, Godard cost based approach is considered for spatio-temporal equalization and MIMO impulse response estimation. Stationary points of the cost function are investigated and it is shown that all stable local minima correspond to desirable minima when doubly infinite equalizers are used. Analysis is also provided for the case when finite-length equalizers exist. The various input sequences are extracted and cancelled one-by-one. The matrix impulse response is then obtained by cross-correlating the extracted inputs with the observed outputs. Identifiability conditions are analyzed. Computer simulation examples are presented to illustrate the proposed approach.

  1. Separating Item and Order Information through Process Dissociation

    ERIC Educational Resources Information Center

    Nairne, James S.; Kelley, Matthew R.

    2004-01-01

    In the present paper, we develop and apply a technique, based on the logic of process dissociation, for obtaining numerical estimates of item and order information. Certain variables, such as phonological similarity, are widely believed to produce dissociative effects on item and order retention. However, such beliefs rest on the questionable…

  2. Functionalized sorbent for chemical separations and sequential forming process

    DOEpatents

    Fryxell, Glen E [Kennewick, WA; Zemanian, Thomas S [Richland, WA

    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.

  3. 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

  4. 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.

  5. 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).

  6. Electric currents couple spatially separated biogeochemical processes in marine sediment.

    PubMed

    Nielsen, Lars Peter; Risgaard-Petersen, Nils; Fossing, Henrik; Christensen, Peter Bondo; Sayama, Mikio

    2010-02-25

    Some bacteria are capable of extracellular electron transfer, thereby enabling them to use electron acceptors and donors without direct cell contact. Beyond the micrometre scale, however, no firm evidence has previously existed that spatially segregated biogeochemical processes can be coupled by electric currents in nature. Here we provide evidence that electric currents running through defaunated sediment couple oxygen consumption at the sediment surface to oxidation of hydrogen sulphide and organic carbon deep within the sediment. Altering the oxygen concentration in the sea water overlying the sediment resulted in a rapid (<1-h) change in the hydrogen sulphide concentration within the sediment more than 12 mm below the oxic zone, a change explicable by transmission of electrons but not by diffusion of molecules. Mass balances indicated that more than 40% of total oxygen consumption in the sediment was driven by electrons conducted from the anoxic zone. A distinct pH peak in the oxic zone could be explained by electrochemical oxygen reduction, but not by any conventional sets of aerobic sediment processes. We suggest that the electric current was conducted by bacterial nanowires combined with pyrite, soluble electron shuttles and outer-membrane cytochromes. Electrical communication between distant chemical and biological processes in nature adds a new dimension to our understanding of biogeochemistry and microbial ecology.

  7. 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.

  8. 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.

  9. Electro-separations: Efficient processing for the twenty-first century

    SciTech Connect

    Byers, C.H.; Amarnath, A.

    1994-04-18

    Electro-separations, the separation of mixtures driven by electricity, either directly or indirectly are shown to have significant application to the process industries. Categories discussed include, electric current phenomena, field-driving processes, convective transport enhancement, and flow stabilization. In each case, the status of a currently significant separation technique is reviewed, A general discussion of developing techniques and research and development needs and opportunities concludes the discussion.

  10. 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.

  11. 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).

  12. Sensitivity of Precipitation Processes to Microphysics and Resolution in a Cloud-Resolving Model

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kao

    2003-01-01

    The Goddard Cumulus Ensemble (GCE) model is used to examine the impact of various microphysical schemes, and vertical and horizontal resolution on the development, intensity and rainfall associated with mesoscale convective systems, idealized hurricanes and an ensemble of clouds. The model variables include horizontal and vertical velocities, potential temperature, perturbation pressure, turbulent kinetic energy, and mixing ratios of all water phases (vapor, liquid, and ice). The major characteristics of the GCE model are the explicit representation of warm rain and ice microphysical processes, and their complex interactions with solar and infrared radiative transfer processes, and with surface processes. For idealized hurricane, an axisymmetric version of the GCE model was developed and used successfully to simulate the tropical cyclogenesis process using both a Rankin vortex and saturated air within a specified radius as initial conditions. For mesoscale convective systems, the 3-D version of the GCE model was used to simulate squall lines that developed in the western Pacific, South China Sea, eastern Atlantic, South America and central U.S. For the cloud ensemble, the GCE model was integrated for several days in order to have good sampling of cloud statistics. In this paper, the sensitivities of hurricane intensity to various microphysical processes and model grid resolution will be examined. This will be mainly achieved by performing sensitivity tests using various horizontal (from 1- to 5-kilometers) and vertical resolutions (from 20- to 200-meters in the lower troposphere to 200- to 500-m in the middle and upper troposphere). Sensitivity tests using various microphysical schemes (warm rain only, and three ice with either graupel or hail) will also be performed. The PBL and diurnal variation of precipitation processes will also be evaluated. The budgets will be calculated for different regions (i.e., convective and stratiform regions).

  13. 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.

  14. Effects of Family Structure on the Adolescent Separation-Individuation Process.

    ERIC Educational Resources Information Center

    McCurdy, Susan J.; Scherman, Avraham

    1996-01-01

    Examined the effects of college students' (n=90) family structures on the separation-individuation process. Family structure groups investigated were intact; divorced, mother-custody, no remarriage; and divorced, mother-custody, remarried. The components of the separation-individuation process examined were attachment to parents, conflictual…

  15. The Separation-Individuation Process and Culture: A Study on Taiwan's College Students.

    ERIC Educational Resources Information Center

    Tam, Wai-Cheong Carl; Shiah, Yung-Jong; Chiang, Shih-Kuang

    The separation-individuation process of individuals is mediated by cultural factors of the society to which the individuals belong. Since the Chinese culture emphasizes collectivism rather than the individualism of Western culture, it is believed that there are differences in the separation-individuation process of individuals between the two…

  16. Effects of Family Structure on the Adolescent Separation-Individuation Process.

    ERIC Educational Resources Information Center

    McCurdy, Susan J.; Scherman, Avraham

    1996-01-01

    Examined the effects of college students' (n=90) family structures on the separation-individuation process. Family structure groups investigated were intact; divorced, mother-custody, no remarriage; and divorced, mother-custody, remarried. The components of the separation-individuation process examined were attachment to parents, conflictual…

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. Optimal separation of jojoba protein using membrane processes

    SciTech Connect

    Nabetani, Hiroshi; Abbott, T.P.; Kleiman, R.

    1995-05-01

    The efficiency of a pilot-scale membrane system for purifying and concentrating jojoba protein was estimated. In this system, a jojoba extract was first clarified with a microfiltration membrane. The clarified extract was diafiltrated and the protein was purified with an ultrafiltration membrane. Then the protein solution was concentrated with the ultrafiltration membrane. Permeate flux during microfiltration was essentially independent of solids concentration in the feed, in contrast with the permeate flux during ultrafiltration which was a function of protein concentration. Based on these results, a mathematical model which describes the batchwise concentration process with ultrafiltration membranes was developed. Using this model, the combination of batchwise concentration with diafiltration was optimized, and an industrial-scale process was designed. The effect of ethylenediaminetetraacetic acid (EDTA) on the performance of the membrane system was also investigated. The addition of EDTA increased the concentration of protein in the extract and improved the recovery of protein in the final products. The quality of the final product (color and solubility) was also improved. However, EDTA decreased permeate flux during ultrafiltration.

  2. 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.

  3. Sensitivity of Precipitation Processes of Microphysics and Resolution in a Cloud-Resolving Model

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo

    2003-01-01

    The Goddard Cumulus Ensemble (GCE) model is used to examine the impact of various microphysical schemes, and vertical and horizontal resolution ion the development, intensity and rainfall associated with mesoscale convective systems, idealized hurricanes and an ensemble f clouds. The model variables include horizontal and vertical velocities, potential temperatures, perturbation pressure, turbulent kinetic energy, and mixing ratios of all water phases (vapor, liquid, and ice). The major characteristics of the GCE model are the explicit representation of warm rain and ice microphysical processes, and their complex interactions with solar and infrared radiative transfer processes, and with surface processes. For idealized hurricane, an axisymmetric version of the GCE model was developed and used successfully to simulate the tropical cyclogenesis process using both a Rankin vortex and saturated air within a specified radius as initial conditions. For mesoscale convective systems, the 3-D version of the GCE model was used to simulated squall lines that developed in the western Pacific, eastern Atlantic and central US. For the cloud ensemble, the GCE model was integrated for several days in order to have good sampling of cloud statistics. In this paper, the sensitivities of hurricane intensity to various microphysical processes and model grid resolution will be examined. This will be mainly achieved by performing sensitivity tests using various horizontal (from 1- to 5-km) and vertical resolutions (from 20- to 200-m in the lower troposphere to 200- to 500-m in the middle and upper troposphere). Sensitivity tests using various microphysical schemes (warm rain only, and three ice with either graupel or hail) will also be performed. The thermodynamic and water budget associated with various types of precipitation systems will also be evaluated. The budgets will be calculated for different regions (i.e., convective and stratiform regions).

  4. Sensitivity of Precipitation Processes to Microphysics and Resolution in a Cloud Resolving Model

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo

    2003-01-01

    The Goddard Cumulus Ensemble (GCE) model examines the impact of various microphysical schemes, and vertical and horizontal resolution in the development, intensity and rainfall associated with mesoscale convective systems, idealized hurricanes and an ensemble of clouds. The model variables include horizontal and vertical velocities, potential temperature, perturbation pressure, turbulent kinetic energy, and mixing rations of all water phases (vapor, liquid and ice). The major characteristics of the GCE model are the explicit representation of warm rain and ice microphysical processes, and their complex interactions with solar and infrared radiative transfer processes and with surface processes. For idealized hurricanes, an axisymmetric version of the GCE model was developed and used to simulate the tropical cyclogenesis process using both a Rankin vortex and saturated air within a specified radius as initial conditions. For mesoscale convective systems, the 3-D version of the GCE model was use to simulate squall lines that developed in the western Pacific, South China Sea, eastern Atlantic, South America and central U.S. FOr the cloud ensemble, the GCE model was integrated for several days in order to have a good sampling of cloud statistics. In this paper, the sensitivities of hurricane intensity to various microphysical processes and model grid resolutio will be examined. This will be mainly achieved by performing sensitivity tests using various horizontal (from 1-to 5-km) and vertical resolutions (from 20- to 200-m in the lower troposphere to 200- to 500m in the middle and upper troposphere). Sensitivity test using various microphysical schemes (warm rain only, and three ice with either graupel or hail) will also be performed. The thermodynamic and water budget associated with various types of precipitation systems will also be evaluated. The budgets will be calculated for different regions (i.e., convective and stratiform regions).

  5. 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

  6. 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.

  7. Weathering processes and pickeringite formation in a sulfidic schist: a consideration in acid precipitation neutralization studies

    SciTech Connect

    Parnell, R.A. Jr.

    1983-01-01

    Extremely low abrasion pH values (2.8-3.3) characterize the weathering products of the Partridge Formation, a Middle-Ordovician metamorphosed, black, sulfidic shale. The local occurrence is observed of two sulfates that are rare in the Northeast: pickeringite and jarosite. X-ray diffraction studies of the weathering residues and the sulfate efflorescences have also identified dioctahedral and trioctahedral illite, kaolinite, vermiculite, and an 11-12 Angstrom phase, thought to be a type of randomly-interstratified biotite-vermiculite. From the mineralogical studies, qualitative weathering processes for the schist are formulated. A probable mechanism for the intense chemical weathering of the schist appears to be oxidation of iron sulfides to form iron oxide-hydroxides, sulfates, and sulfuric acid. This natural weathering process is proposed as an analog to anthropogenic low pH rock weathering resulting from acid precipitation. In the Northeast, natural weathering rates, may, in places, significantly affect the water chemistry and mineralogy used to quantify total (natural plus anthropogenic) weathering and leaching rates. 27 references, 4 figures.

  8. Sb-Doped SnO2 Nanoparticles Synthesized by Sonochemical-Assisted Precipitation Process.

    PubMed

    Noonuruk, Russameeruk; Vittayakorn, Naratip; Mekprasart, Wanichaya; Sritharathikhun, Jaran; Pecharapa, Wisanu

    2015-03-01

    Sb-doped SnO2 nanopowders were synthesized by sonochemical-assisted precipitation process using stannic chloride pentahydrate (SnCl4.5H2O) and antimony chloride (SbC3) as starting precursors. Effect of sonication and Sb doping concentrations on physical structures and electrical properties of Sb-doped SnO2 nanoparticles were investigated by X-ray diffraction, transmission electron microscope, X-ray photoelectron spectroscopy, Raman spectroscopy and two-point probe method. The results indicated that the good dispersion with less agglomeration of particles in SnO2 phase can be obtained by single step sonochemical-assisted process. Moreover, XRD results indicated that the crystallinity of Sb-doped SnO2 nanopowders deteriorated with increasing Sb content, suggesting that Sb dopant significantly prevent SnO2 crystallite growth. The XPS spectra of Sb-doped SnO2 obviously confirmed the existence of Sb ion incorporated into SnO2 matrix. These results revealed that incorporation of Sb ions into SnO2 lattice with specific concentration has significant influence on formation and crystallization and can dramatically enhance the conductivity of tin oxide.

  9. 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)

  10. 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.

  11. Application of chemical precipitation and membrane bioreactor hybrid process for piggery wastewater treatment.

    PubMed

    Kornboonraksa, Thipsuree; Lee, Hong Shin; Lee, Seung Hwan; Chiemchaisri, Chart

    2009-03-01

    This study was conducted to investigate the chemical precipitation (CP) and membrane bioreactor (MBR) hybrid process for the treatment of piggery wastewater. Average removal efficiencies for BOD, COD and turbidity in CP process were 64.3%, 77.3% and 96.4%, respectively. CP process had a moderate effect on NH(3)-N removal (40.4%) which improved up to 98.2% mainly due to nitrification and filtration processes in MBR. The average removal efficiencies of BOD, COD and turbidity in MBR were 99.5%, 99.4% and 99.8%, respectively. Monod equation was used to explain the microbial activities in terms of specific growth rate. The specific growth rate of bacteria in aeration tank (N-batch) and anoxic tank (D-batch) were 0.013 and 0.005d(-1) with a biomass yield of 0.78 and 0.43mg MLSS produced/mg COD utilized, respectively. Microorganisms from the N-batch and D-batch showed a low-level of nitrifying and moderate-level of denitrifying capabilities which were 1.08mg NH(3)-N/(g MLVSS.h) and 2.82mg NO(3)-N/(g MLVSS.h), respectively. Carbohydrates were the main component in extracellular polymeric substance (EPS) compounds that could be attached to the membrane surface easily and led to membrane biofouling. The increase of MLSS, EPS and sludge viscosity concentration, decrease of sludge floc size and incomplete chemical cleaning procedure resulted in the increase of membrane resistance. Total membrane resistance increased from 3.19x10(12)m(-1) to 5.43x10(14)m(-1).

  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. Continuous precipitation of process related impurities from clarified cell culture supernatant using a novel coiled flow inversion reactor (CFIR).

    PubMed

    Kateja, Nikhil; Agarwal, Harshit; Saraswat, Aditya; Bhat, Manish; Rathore, Anurag S

    2016-10-01

    Coiled Flow Inverter Reactor (CFIR) has recently been explored for facilitating continuous operation of several unit operations involved in downstream processing of biopharmaceuticals such as viral inactivation and protein refolding. The application of CFIR for continuous precipitation of clarified cell culture supernatant has been explored. The pH based precipitation is optimized in the batch mode and then in the continuous mode in CFIR using a design of experiments (DOE) study. Improved clearance of host cell DNA (52× vs. 39× in batch), improved clearance of host cell proteins (HCP) (7× vs. 6× in batch) and comparable recovery (90 vs. 91.5 % in batch) are observed along with six times higher productivity. To further demonstrate wider applicability of CFIR in performing continuous precipitation, two more case studies involving use of two different precipitation protocols (CaCl2 based and caprylic acid based) are also performed. In both cases, clearance of host cell DNA, HCP, and product recovery are found to be comparable or better in CFIR than in batch operations. Moreover, increase in productivity of 16 times (CaCl2 based) and eight times (caprylic acid based) is obtained for the two precipitation protocols, respectively. The data clearly demonstrate that CFIR can be seamlessly integrated into a continuous bioprocess train for performing continuous precipitation of clarified cell culture supernatant. To our knowledge this is the first report of such use.

  14. Effect of Processing Scheme on Precipitation Mechanisms and Evolution of Microstructures and Properties of CuAgZr alloy

    NASA Astrophysics Data System (ADS)

    Piyawit, Waraporn

    CuAgZr alloy is a variant of the CuAg alloy that is developed for high strength and high conductivity applications. With Zr addition, the discontinuous precipitation at the grain boundaries is decreased due to slower Ag diffusion rate. Mechanical and electrical properties of copper alloys can be influenced by many factors including alloying elements, mechanical processing, heat treatment and their microstructures. For high strength and high conductivity applications, Cu-Ag alloys are one of the good candidate materials for these used because of their excellent combinations of high strength and high electrical conductivity. The primary strengthening mechanism is precipitation hardening due to the formation of Ag precipitates during the heat treatment process. Its strengthening is accomplished mainly by the precipitation of Ag precipitates, which tend to align on the {111} planes in the Cu matrix. The evolutions of hardness and electrical conductivity of the aged samples showed that the Ag particles precipitated out from the Cu matrix in the early stage of aging. The hardness of the aged samples is significantly increased from 95 HV0.1 to the maximum at 193 HV0.1 after 2 hours of aging. The density of Ag precipitates is increased with increased aging time. Ag precipitation occurs in particular Cu matrix planes due to the minimization of elastic energy. The Ag precipitates were formed by clustering of Ag atoms while maintaining the fcc crystal structure of the matrix. They have faceted {111} interfaces with the matrix. The thickening of the precipitates appears to be by the ledge growth mechanism, which is promoted by misfit dislocation networks on the interface. The ledge movement and growth were compensated with the existence of interfacial misfit dislocations. During diffusional growth, misfit dislocation arrays along the precipitate/matrix interface accommodated the lattice mismatch. Therefore, precipitate growth involves the formation and migration of ledges

  15. [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.

  16. Influence of formulation and processing variables on properties of itraconazole nanoparticles made by advanced evaporative precipitation into aqueous solution.

    PubMed

    Bosselmann, Stephanie; Nagao, Masao; Chow, Keat T; Williams, Robert O

    2012-09-01

    Nanoparticles, of the poorly water-soluble drug, itraconazole (ITZ), were produced by the Advanced Evaporative Precipitation into Aqueous Solution process (Advanced EPAS). This process combines emulsion templating and EPAS processing to provide improved control over the size distribution of precipitated particles. Specifically, oil-in-water emulsions containing the drug and suitable stabilizers are sprayed into a heated aqueous solution to induce precipitation of the drug in form of nanoparticles. The influence of processing parameters (temperature and volume of the heated aqueous solution; type of nozzle) and formulation aspects (stabilizer concentrations; total solid concentrations) on the size of suspended ITZ particles, as determined by laser diffraction, was investigated. Furthermore, freeze-dried ITZ nanoparticles were evaluated regarding their morphology, crystallinity, redispersibility, and dissolution behavior. Results indicate that a robust precipitation process was developed such that size distribution of dispersed nanoparticles was shown to be largely independent across the different processing and formulation parameters. Freeze-drying of colloidal dispersions resulted in micron-sized agglomerates composed of spherical, sub-300-nm particles characterized by reduced crystallinity and high ITZ potencies of up to 94% (w/w). The use of sucrose prevented particle agglomeration and resulted in powders that were readily reconstituted and reached high and sustained supersaturation levels upon dissolution in aqueous media.

  17. 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.

  18. North American monsoon precipitation and its precursors: Processes at the seasonal and diurnal scale

    NASA Astrophysics Data System (ADS)

    Gaynor, Nicole June Schiffer

    The Weather Research and Forecasting (WRF) model was run at 100 km, 25 km, and 10 km resolution for the 2000 and 2004 monsoon seasons (July-September), a dry year and a wet year. These years were chosen to represent contrasting precipitation outcomes to assure that results were robust across different monsoon conditions. Model precipitation was compared to precipitation from the Modern-Era Retrospective Reanalysis (MERRA), the North American Regional Reanalysis (NARR), and Tropical Rainfall Measuring Mission (TRMM). Then WRF, MERRA, and NARR were used to investigate the relationships between precipitation and the other moisture budget variables, the large-scale flow, and atmospheric stability on the seasonal and diurnal scales. On both the seasonal and diurnal scale, flow was key to the location and intensity of precipitation. In 2004, the subtropical high over the south-central United States was about 300 km west of its location in 2000 at 700 hPa. The shift was also evident in vertically-integrated moisture flux, which then changed the pattern and intensity of moisture flux convergence (MFC), convective available potential energy (CAPE) and convective inhibition (CIN), and precipitation over Mexico and the Gulf of California. Over Arizona and New Mexico, transient disturbances, like tropical waves, were more important than the diurnal cycle to precipitation. Despite similar spatial distributions of precipitation, WRF, NARR, MERRA, and TRMM showed very different frequencies of light and heavy rain. Such uncertainty in the character of rainfall can impact a variety of stakeholders and decision makers across the NAM region. The WRF model tended to produce heavier precipitation across the NAM region compared to MERRA, NARR, and TRMM as a result of stronger MFC and higher CAPE, especially over the Gulf of California. Beyond the resolution needed to adequately reproduce the Baja California and Gulf of California, higher model resolution tended to increase and localize

  19. 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.

  20. 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.

  1. 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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. 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.

  3. 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

    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

  4. 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?

  5. 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?

  6. 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.

  7. Synthesis and photocatalytic performances of BiVO 4 by ammonia co-precipitation process

    NASA Astrophysics Data System (ADS)

    Yu, Jianqiang; Zhang, Yan; Kudo, Akihiko

    2009-02-01

    This paper reports the preparation and photocatalytic performance of Bismuth vanadate (BiVO 4) by a facile and inexpensive approach. An amorphous BiVO 4 was first prepared by a co-precipitation process from aqueous solutions of Bi(NO 3) 3 and NH 4VO 3 using ammonia. Followed by heating treatment at various temperatures, the amorphous phase converted to crystalline BiVO 4 with a structure between monoclinic and tetragonal scheelite. The crystallization of BiVO 4 occurred at about 523 K, while the nanocrystalline BiVO 4 were formed with a heat-treatment of lower than 673 K. However, when the heat-treatment was carried out at 773 K, the accumulation of nanocrystals to bulk particles was observed. The photocatalytic performances of the materials were investigated by O 2 evolution under visible-light, and MB decomposition under solar simulator. The results demonstrated that the crystalline structure is still the vital factor for the activities of both reactions. However, the crystallinity of BiVO 4 gives a major influence on the activity of O 2 evolution, whereas the surface area, plays an important role for photocatalytic MB decomposition.

  8. 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

  9. Separation of high-purity syringol and acetosyringone from rice straw-derived bio-oil by combining the basification-acidification process and column chromatography.

    PubMed

    Hao, Shilai; Chen, Kaifei; Cao, Leichang; Zhu, Xiangdong; Luo, Gang; Zhang, Shicheng; Chen, Jianmin

    2016-10-01

    Numerous technologies have been used to reclaim valuable chemicals from bio-oil. In this study, a combination of the basification-acidification process and column chromatography was employed for the separation of high-purity syringol and acetosyringone from rice straw-derived bio-oil. The optimal conditions for the basification-acidification process and the possible precipitation mechanism of the basification were explored. The results showed the following as the optimal conditions for the basification process: mass ratio of calcium hydroxide (Ca(OH)2 ) to bio-oil, 2.0; reaction temperature, 70°C; and reaction time, 30 min. The results also showed that 1.6 mol of hydrochloric acid (HCl) per gram of bio-oil was optimal for the acidification. The precipitation was found to proceed via a possible mechanism involving the reaction of the phenolic compounds in the bio-oil with Ca(OH)2 to produce a precipitate. After further separation by column chromatography, purities of 91.4 and 96.2% (from gas chromatography-mass spectrometry) were obtained for syringol and acetosyringone, respectively. Their recoveries for the whole process were 73.0 and 39.3%, respectively.

  10. 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.

  11. 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.

  12. The effect of weak chelating agents on the removal of heavy metals by precipitation processes

    SciTech Connect

    Ku, Y.; Peters, W.

    1986-01-01

    Particle size distributions and heavy metal removals are presented for hydroxide precipitation and sulfide precipitation of zinc and cadmium in the presence of several weak complexing agents, namely citrate, tartrate, and ammonia. The pH was held constant at pH 10.0 in these experiments. The presence of these weak complexing agents had little effect on the chemical equilibrium for both the hydroxide and sulfide systems due to their weak complexing ability with metal ions. The presence of the complexing agents does affect the particle size distribution, generally forming smaller particles. Particle size distributions are presented for the Zn(OH)/sub 2/, ZnS, Cd(OH)/sub 2/, and CdS systems (at pH 10.0) in the presence of the chelating agents citrate, tartrate, and ammonia. Sulfide precipitation exhibits a better particle size distribution and settling characteristics than the corresponding metal hydroxide precipitation for both zinc and cadmium.

  13. Characterization of a nutrient feed precipitate from an E. coli fermentation process.

    PubMed

    Speciner, Lauren; Mallon, Erin; Leung, Susan; Laird, Michael W; Esue, Osigwe

    2010-01-01

    Metalloproteins require soluble metal ions such as zinc to properly fold into their native and active state to maintain stability and biological activity. When protein products are produced during microbial fermentations, metals are made available to the metalloproteins via nutrient supplements. During the production at the manufacturing-scale of a recombinant product that required zinc as a cofactor, an insoluble precipitate formed in the preparation tank after steam sterilization of the nutrient feed containing methionine, glycerophosphate, and zinc sulfate (MGZ). The precipitated nutrient feed was believed to be the cause for not enough zinc delivered to the production fermentor, leading to poor product assembly and stabilization. This article explores several analytical techniques such as capillary zone electrophoresis, inductively coupled plasma and phosphate molybdate assays to identify and quantify the composition of the precipitate. Our results show that the glycerophosphate component of the combined MGZ nutrient feed contains inorganic phosphate, which precipitates zinc from the feed media.

  14. Interface-coupled dissolution-precipitation processes during acidic weathering of multicomponent minerals

    NASA Astrophysics Data System (ADS)

    Ruiz-Agudo, Encarnacion; King, Helen E.; Patiño-López, Luis D.; Putnis, Christine V.; Geisler, Thorsten; Rodriguez-Navarro, Carlos M.; Putnis, Andrew

    2015-04-01

    The chemical weathering of carbonate and silicate minerals on the Earth's surface controls important geochemical processes such as erosion rates and soil formation, ore genesis or climate evolution. The dissolution of most of these minerals is typically incongruent, and results in the formation of surface coatings (altered layers, also known as leached layers). These coatings may significantly affect mineral dissolution rates over geological timescales, and therefore a great deal of research has been conducted on them. However, the mechanism of leached layer formation is a matter of vigorous debate. Here we report on an in situ atomic force microscopy (AFM) and real-time Mach-Zehnder phase-shift interferometry (PSI) study of the dissolution of wollastonite, CaSiO3, and dolomite, CaMg(CO3)2, as an example of surface coating formation during acidic weathering of multicomponent minerals. Our in situ results provide clear direct experimental evidence that leached layers are formed in a tight interface-coupled two-step process: stoichiometric dissolution of the pristine mineral surfaces and subsequent precipitation of a secondary phase (silica in the case of wollastonite, or hydrated magnesium carbonate in the case of dolomite) from a supersaturated boundary layer of fluid in contact with the mineral surface. This occurs despite the bulk solution remaining undersaturated with respect to the secondary phase. The validation of such a mechanism given by the results reported here completely changes the conceptual framework concerning the mechanism of chemical weathering, and differs significantly from the concept of preferential leaching of cations postulated by most currently accepted incongruent dissolution models.

  15. 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)

  16. Understanding the influence of orography on the precipitation diurnal cycle and the associated atmospheric processes in the central Andes

    NASA Astrophysics Data System (ADS)

    Junquas, C.; Takahashi, K.; Condom, T.; Espinoza, J.-C.; Chavez, S.; Sicart, J.-E.; Lebel, T.

    2017-08-01

    In the tropical Andes, the identification of the present synoptic mechanisms associated with the diurnal cycle of precipitation and its interaction with orography is a key step to understand how the atmospheric circulation influences the patterns of precipitation variability on longer time-scales. In particular we aim to better understand the combination of the local and regional mechanisms controlling the diurnal cycle of summertime (DJF) precipitation in the Northern Central Andes (NCA) region of Southern Peru. A climatology of the diurnal cycle is obtained from 15 wet seasons (2000-2014) of 3-hourly TRMM-3B42 data (0.25° × 0.25°) and swath data from the TRMM-2A25 precipitation radar product (5 km × 5 km). The main findings are: (1) in the NCA region, the diurnal cycle shows a maximum precipitation occurring during the day (night) in the western (eastern) side of the Andes highlands, (2) in the valleys of the Cuzco region and in the Amazon slope of the Andes the maximum (minimum) precipitation occurs during the night (day). The WRF (Weather Research and Forecasting) regional atmospheric model is used to simulate the mean diurnal cycle in the NCA region for the same period at 27 km and 9 km horizontal grid spacing and 3-hourly output, and at 3 km only for the month of January 2010 in the Cuzco valleys. Sensitivity experiments were also performed to investigate the effect of the topography on the observed rainfall patterns. The model reproduces the main diurnal precipitation features. The main atmospheric processes identified are: (1) the presence of a regional-scale cyclonic circulation strengthening during the afternoon, (2) diurnal thermally driven circulations at local scale, including upslope (downslope) wind and moisture transport during the day (night), (3) channelization of the upslope moisture transport from the Amazon along the Apurimac valleys toward the western part of the cordillera.

  17. 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

  18. 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

  19. 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 ...

  20. 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...

  1. 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 ...

  2. 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...

  3. Fine coal fractionation using a magnetohydrostatic separation process CRADA 91-003. Final report

    SciTech Connect

    Cho, Heechan; Killmeyer, R. P.

    1992-10-31

    The magnetohydrostatic separation (MHS) process uses a magnetic fluid which has the ability to float a submerged particle in a magnetic field. The objective of this project was to develop a technique for laboratory gravity fractionation of coal using MHS.

  4. A Review of Biorefinery Separations for Bioproduct Production via Thermocatalytic Processing.

    PubMed

    Nguyen, Hannah; DeJaco, Robert F; Mittal, Nitish; Siepmann, J Ilja; Tsapatsis, Michael; Snyder, Mark A; Fan, Wei; Saha, Basudeb; Vlachos, Dionisios G

    2017-03-15

    With technological advancement of thermocatalytic processes for valorizing renewable biomass carbon, development of effective separation technologies for selective recovery of bioproducts from complex reaction media and their purification becomes essential. The high thermal sensitivity of biomass intermediates and their low volatility and high reactivity, along with the use of dilute solutions, make the bioproducts separations energy intensive and expensive. Novel separation techniques, including solvent extraction in biphasic systems and reactive adsorption using zeolite and carbon sorbents, membranes, and chromatography, have been developed. In parallel with experimental efforts, multiscale simulations have been reported for predicting solvent selection and adsorption separation. We summarize various separations that can be valuable to future biorefineries and the factors controlling separation performance. Particular emphasis is given to current gaps and opportunities for future development. Expected final online publication date for the Annual Review of Chemical and Biomolecular Engineering Volume 8 is June 7, 2017. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

  5. 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.

  6. Dynamic strain aging precipitation of Mg17Al12 in AZ80 magnesium alloy during multi-directional forging process

    NASA Astrophysics Data System (ADS)

    Zhu, Q. F.; Wang, G. S.; Wang, X. J.; Liu, F. Z.; Ban, C. Y.; Cui, J. Z.

    2017-05-01

    Dynamic aging precipitation of Mg17Al12 phases in AZ80 magnesium alloy was studied by multi-directional forging (MDF) with decreasing temperatures from 410 to 300 °C. The results show that the morphology of the dynamically precipitated β-Mg17Al12 phases (formed during forging process) exhibited granular shape. During the multi-directional forging process, the inhomogeneous dynamic precipitation of the β-Mg17Al12 phases result in the coexistence of the fine grains (with many granular Mg17Al12 phases) and coarse grains (without Mg17Al12 phases) in the samples. The fine grains (with many granular Mg17Al12 phases) area expands with the decreasing of final forging temperature. The inhomogenous Al content distribution in the Mg matrix leads to the non-uniform dynamic precipitation of the Mg17Al12 phase. These Mg17Al12 phase retards the growth of the DRX grains, which in turns results in the formation fine grains area during the during the MDF process with temperature decreasing.

  7. Separation-Individuation Process of Taiwan High School Students and Its Implications in Counseling.

    ERIC Educational Resources Information Center

    Shiah, Yung-Jong; Tam, Wai-Cheong Carl; Chiang, Shih-Kuang

    The separation-individuation process is an important developmental process of the individual self, and disturbances in this process may lead to the manifestation of borderline personality symptoms. Previous studies have shown that the psychological developmental stages of the Chinese children and adolescents in Taiwan occur at an older age…

  8. Adsorptive process design for the separation of hexane isomers using zeolites.

    PubMed

    Luna-Triguero, A; Gómez-Álvarez, P; Calero, S

    2017-02-15

    The product of catalytic isomerization is a mixture of linear and branched hydrocarbons that are in thermodynamic equilibrium, and their separation becomes necessary in the petrochemical industry. Zeolite 5A is usually industrially used to sieve alkane isomers, but its pore size allows only the separation of linear alkanes from the monobranched and dibranched alkanes by a kinetic mechanism. A more efficient approach to improve the average research octane number would be to adsorptively separate the di-methyl alkanes as products and recycle both the linear and mono-methyl alkanes to the isomerization reactor. Since the microscopic processes of adsorbates in zeolites are generally difficult or impossible to determine by experiments, especially in the case of mixtures, molecular simulation represents an attractive alternative. In this computational study, we propose a conceptual separation process for hexane isomers consisting of several adsorptive steps. Different zeolite topologies were examined for their ability to conduct this separation based on adsorption equilibrium and kinetics.

  9. Development and demonstration of solvent extraction processes for the separation of radionuclides from acidic radioactive waste

    SciTech Connect

    Law, J.D.; Brewer, K.N.; Herbst, R.S.; Todd, T.A.; Wood, D.J.

    1999-06-01

    The presence of long-lived radionuclides presents a challenge to the management of radioactive wastes. Immobilization of these radionuclides must be accomplished prior to long-term, permanent disposal. Separation of the radionuclides from the waste solutions has the potential of significantly decreasing the costs associated with the immobilization and disposal of the radioactive waste by minimizing waste volumes. Several solvent extraction processes have been developed and demonstrated at the Idaho National Engineering and Environmental Laboratory for the separation of transuranic element (TRUs), {sup 90}Sr, and/or {sup 137}Cs from acidic radioactive waste solutions. The Transuranic Extraction (TRUEX) and phosphine oxide (POR) processes for the separation of TRUs, the Strontium Extraction (SREX) process for the separation of {sup 90}Sr, the chlorinated cobalt dicarbollide (ChCoDiC) process for the separation of {sup 137}Cs and {sup 90}Sr, and a universal solvent extraction process for the simultaneous separation of TRUs, {sup 90}Sr, and {sup 137}Cs have all been demonstrated in centrifugal contactors using actual radioactive waste solutions. This article summarizes the most recent results of each of the flowsheet demonstrations and allows for comparison of the technologies. The successful demonstration of these solvent extraction processes indicates that they are all viable for the treatment of acidic radioactive waste solutions.

  10. 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.

  11. 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.

  12. 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.

  13. 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).

  14. Single-channel mixed signal blind source separation algorithm based on multiple ICA processing

    NASA Astrophysics Data System (ADS)

    Cheng, Xiefeng; Li, Ji

    2017-01-01

    Take separating the fetal heart sound signal from the mixed signal that get from the electronic stethoscope as the research background, the paper puts forward a single-channel mixed signal blind source separation algorithm based on multiple ICA processing. Firstly, according to the empirical mode decomposition (EMD), the single-channel mixed signal get multiple orthogonal signal components which are processed by ICA. The multiple independent signal components are called independent sub component of the mixed signal. Then by combining with the multiple independent sub component into single-channel mixed signal, the single-channel signal is expanded to multipath signals, which turns the under-determined blind source separation problem into a well-posed blind source separation problem. Further, the estimate signal of source signal is get by doing the ICA processing. Finally, if the separation effect is not very ideal, combined with the last time's separation effect to the single-channel mixed signal, and keep doing the ICA processing for more times until the desired estimated signal of source signal is get. The simulation results show that the algorithm has good separation effect for the single-channel mixed physiological signals.

  15. 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.

  16. Comparison of precipitate behaviors in ultra-low carbon, titanium-stabilized interstitial free steel sheets under different annealing processes

    SciTech Connect

    Shi, J.; Wang, X.

    1999-12-01

    Ultra-low carbon, titanium-stabilized interstitial free (ULC Ti-IF) steel sheets are widely used in the automobile industry because of excellent deep drawability. The annealing process is critical to their final property, and there are two different annealing processes used in industrial production of interstitial free (IF) steel sheets, namely batch annealing and continuous annealing. In this study, precipitation behaviors of titanium IF steels, that is, TiN, TiS, Ti{sub 4}(CS){sub 2}, and TiC, the size and dispersion of TiN, TiS, and Ti{sub 4}(CS){sub 2} remained almost unchanged after either annealing process. Conversely, the average size of a TiC particle increased substantially after both annealing processes, while TiC after continuous annealing was larger than that after batch annealing due to the higher heating temperature of continuous annealing. Two new particles, FeTiP and (Ti, Mn)S, were also observed in the batch annealing process but not in continuous annealing. The structure of FeTiP and (Ti, Mn)S were studied, and furthermore the evolution of FeTiP precipitation was found to be closely related to recrystallization in batch annealing. Finally, the interrelation among processing parameters, precipitation behaviors, and final property was studied.

  17. 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.

  18. 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

  19. 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.

  20. Kinetic crystallization separation process of the inositol isomers by controlling metastable zones

    NASA Astrophysics Data System (ADS)

    Konuki, Kaname; Hirasawa, Izumi

    2013-06-01

    D-chiro-inositol (DCI) is prepared by the immobilized enzyme reaction which uses myo-inositol (MI) as the substrate and the conversion rate is about 13%. The aim of this study was to develop a separation method for high purity DCI crystals from a reaction solution including low purity DCI only by the crystallization process. We succeeded in separating DCI crystals of 96% purity by water cooling crystallization, but it was presumed that scale-up was difficult. Although we tried anti-solvent crystallization similar to water cooling crystallization, high purity DCI crystals were not obtained. Therefore, we proposed the crystallization separation process by controlling metastable zones. The purity of a desired compound is controlled by this process, because solid-liquid separation is achieved before crystallization of compound in metastable zone. By the crystallization using this method, the DCI crystals of 97% purity were obtained. Although the yield per batch is about 50%, the actual yield is improved as the last mother liquor returns into the process of the following batch. When this process was repeated, the purity and the yield of DCI were reproduced and the robustness of this process was proved. It is expected that scale-up of this process will be successful, and this purification method could be applicable to similar systems such as separation of isomers and analogs.

  1. Exploring geophysical processes influencing U.S. West Coast precipitation and water supply

    USGS Publications Warehouse

    Ralph, F.M.; Prather, K.; Cayan, D.

    2011-01-01

    CalWater Science Workshop; La Jolla, California, 8-10 June 2011 CalWater is a multiyear, multiagency research project with two primary research themes: the effects of changing climate on atmospheric rivers (ARs) and associated extreme events, and the potential role of aerosols in modulating cloud properties and precipitation, especially regarding orographic precipitation and water supply. Advances made in CalWater have implications for both water supply and flood control in California and other West Coast areas, both in the near term and in a changing climate.

  2. Exploring geophysical processes influencing U.S. West Coast precipitation and water supply

    NASA Astrophysics Data System (ADS)

    Ralph, F. Martin; Prather, Kim; Cayan, Dan

    2011-10-01

    CalWater Science Workshop; La Jolla, California, 8-10 June 2011 CalWater is a multiyear, multiagency research project with two primary research themes: the effects of changing climate on atmospheric rivers (ARs) and associated extreme events, and the potential role of aerosols in modulating cloud properties and precipitation, especially regarding orographic precipitation and water supply. Advances made in CalWater have implications for both water supply and flood control in California and other West Coast areas, both in the near term and in a changing climate.

  3. Hypersorption process for separation of components of a medium -Btu gas. Final report. [Gas obtained from Lurgi process, Texaco gasification process, and Foster-Wheeler process

    SciTech Connect

    Not Available

    1982-07-17

    This study has been performed to determine the technical and economic feasibility of employing hypersorption process technology to separate and purify a medium - Btu gas, derived from oxygen-blown gasifiers, to obtain a H/sub 2//CO ratio of 2:1 as a feed to a Fischer-Tropsch type plant. Technical feasibility is a measure of the ability to design a hypersorption separation and purification process from available data. Economic feasibility can be made through comparisons with commercially available process technology. Three gasification processes have been used as a basis for this study. These processes are based upon EPRI Report AF-244 for the Lurgi moving bed, oxygen-blown, dry bottom gasifier, and EPRI Report AF-642 for the Texaco, slurry fed, oxygen-blown, entrained bed gasifier and for the Foster-Wheeler, oxygen-blown, entrained bed gasifier. Process designs for the hypersorption separation and purification for each case have been made using engineering judgments based on the available adsorption isotherms, which have been obtained from the Calgon Corporation. No attempt has been made to optimize these designs although some additional studies have been done where it has been deemed desirable. Cryogenic separation and acid gas purification for each case have been supplied by Lotepro as a packaged unit. Economic evaluations are ambiguous. All plant investments are within the +- 30% accuracy of this study. No clear cut choice between cryogenic separation - acid gas purification and hypersorptive separation - purification can be made based on plant investment. Operating costs are within the +- 30% accuracy. However, in the Foster-Wheeler case the operating costs are 28% greater for the hypersorption process. 12 figures, 42 tables.

  4. Probabilistic forecasts of extreme local precipitation using HARMONIE predictors and comparing 3 different post-processing methods

    NASA Astrophysics Data System (ADS)

    Whan, Kirien; Schmeits, Maurice

    2017-04-01

    Statistical post-processing of deterministic weather forecasts allows production of the full forecast distribution, and thus probabilistic forecasts, to be derived from that deterministic model output. We focus on local extreme precipitation amounts, as these are one predictand used in the KNMI weather warning system. As such, the predictand is based on the maximum hourly calibrated radar precipitation in a 3x3 km2 area within 12 large regions covering The Netherlands in a 6-hour afternoon period in summer (12-18 UTC). We compare three statistical methods when post-processing output from the operational high-resolution forecast model at KNMI, HARMONIE. These methods are 1) extended logistic regression (ELR), 2) an ensemble model output statistics approach where the parameters of a zero-adjusted gamma (ZAGA) distribution depends on a set of covariates and 3) quantile random forests (QRF). The set of predictors used as covariates includes model precipitation and indices capturing a variety of processes associated with deep convection. We use stepwise selection to select predictors for ELR and ZAGA based on the AIC. Predictors and coefficients are selected in a cross-validation framework based one two-years of training data and the skill of the forecasts are assessed on one-year of test data. The inclusion of additional predictors results in more skilfull forecasts, as expected, particularly for higher precipitation thresholds and for forecasts using the QRF method. We also assess the value of using a time-lagged ensemble. Forecasts derived from ZAGA and QRF are generally more skilfull, as defined by the Brier Skill Score, than ELR and lower precipitation amounts are skillfully predicted.

  5. In situ imaging and height reconstruction of phase separation processes in polymer blends during spin coating.

    PubMed

    Ebbens, Stephen; Hodgkinson, Richard; Parnell, Andrew J; Dunbar, Alan; Martin, Simon J; Topham, Paul D; Clarke, Nigel; Howse, Jonathan R

    2011-06-28

    Spin coating polymer blend thin films provides a method to produce multiphase functional layers of high uniformity covering large surface areas. Applications for such layers include photovoltaics and light-emitting diodes where performance relies upon the nanoscale phase separation morphology of the spun film. Furthermore, at micrometer scales, phase separation provides a route to produce self-organized structures for templating applications. Understanding the factors that determine the final phase-separated morphology in these systems is consequently an important goal. However, it has to date proved problematic to fully test theoretical models for phase separation during spin coating, due to the high spin speeds, which has limited the spatial resolution of experimental data obtained during the coating process. Without this fundamental understanding, production of optimized micro- and nanoscale structures is hampered. Here, we have employed synchronized stroboscopic illumination together with the high light gathering sensitivity of an electron-multiplying charge-coupled device camera to optically observe structure evolution in such blends during spin coating. Furthermore the use of monochromatic illumination has allowed interference reconstruction of three-dimensional topographies of the spin-coated film as it dries and phase separates with nanometer precision. We have used this new method to directly observe the phase separation process during spinning for a polymer blend (PS-PI) for the first time, providing new insights into the spin-coating process and opening up a route to understand and control phase separation structures.

  6. Coupling of Spinosad Fermentation and Separation Process via Two-Step Macroporous Resin Adsorption Method.

    PubMed

    Zhao, Fanglong; Zhang, Chuanbo; Yin, Jing; Shen, Yueqi; Lu, Wenyu

    2015-08-01

    In this paper, a two-step resin adsorption technology was investigated for spinosad production and separation as follows: the first step resin addition into the fermentor at early cultivation period to decrease the timely product concentration in the broth; the second step of resin addition was used after fermentation to adsorb and extract the spinosad. Based on this, a two-step macroporous resin adsorption-membrane separation process for spinosad fermentation, separation, and purification was established. Spinosad concentration in 5-L fermentor increased by 14.45 % after adding 50 g/L macroporous at the beginning of fermentation. The established two-step macroporous resin adsorption-membrane separation process got the 95.43 % purity and 87 % yield for spinosad, which were both higher than that of the conventional crystallization of spinosad from aqueous phase that were 93.23 and 79.15 % separately. The two-step macroporous resin adsorption method has not only carried out the coupling of spinosad fermentation and separation but also increased spinosad productivity. In addition, the two-step macroporous resin adsorption-membrane separation process performs better in spinosad yield and purity.

  7. 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.

  8. Development of a process for separation of mogroside V from Siraitia grosvenorii by macroporous resins.

    PubMed

    Zhang, Min; Yang, Huihua; Zhang, Hongyang; Wang, Yuerong; Hu, Ping

    2011-08-25

    A separation method was developed for the preparative separation and enrichment of the non-caloric sweetener mogroside V from Siraitia grosvenorii. The adsorption properties of six macroporous resins were evaluated. Results showed that HZ 806 resin offered the best adsorption and desorption capacities. Based on the adsorption experiments on HZ 806, the adsorption data were found to fit the Freundlich model well. The pseudo-second-order kinetic model showed the highest correlation with the experimental results. Separation was performed with deionized water and 40% aqueous ethanol solution as mobile phases. In a typical run, 100 g of herb was processed and 3.38 g of mogroside V with a purity of 10.7% was harvested. This separation method provided a 15.1-fold increase in the purification factor from 0.5% to 10.7%. The present study showed that HZ 806 resins were effective for the separation and enrichment of mogroside V from S. grosvenorii.

  9. Fraction transfer process in on-line comprehensive two-dimensional liquid-phase separations.

    PubMed

    Česla, Petr; Křenková, Jana

    2017-01-01

    Two-dimensional liquid-phase separations have gained increasing attention for their ability to separate complex sample mixtures. Among the experimental setups used, an on-line approach is preferred to reduce the probability of sample contamination, for easier automation and high-sample throughput. The interfacing of the separation techniques in the on-line mode brings additional demands on proper optimization of the two-dimensional system. In this review, the possibilities of the on-line coupling of liquid chromatography and liquid chromatography with capillary electrophoresis in two-dimensional systems are discussed. Special attention is paid to the fraction transfer process, which includes an overview of interfaces and experimental setups applied, the compatibility issues of separation systems, and instrumental parameters. The benefits and drawbacks of using electromigration separations in combination with liquid chromatography are presented as well.

  10. 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.

  11. 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.

  12. To Catch a Cloud - Multiscale Precipitation Processes in the Andes and in the Himalayas

    NASA Astrophysics Data System (ADS)

    Barros, A. P.; Eghdami, M.; Duan, Y.; Wilson, A. M.

    2016-12-01

    A synthesis from ground- and satellite-based observations and modeling studies in the Central Himalayas and in the Central Andes toward characterizing the altitudinal organization of precipitation regimes in High-Mountains is presented focusing on local and remote controls of the seasonality of moisture transport, terrain topology (connectivity, gradients and barriers) and vegetation controls on the diurnal cycle cloudiness and precipitation, and cloud-rainfall interaction controls of precipitation intensity and duration. Detailed observations and modeling studies of selected events during the monsoon and in the transition seasons will be anaflyzed as follows: 1) the inter-annual variability of monsoon onset and winter storms with implications for the spatial dynamics of flooding and drought in the Himalayas, 2) cloud runup at the treeline with implications for the altitudinal capping of rainfall in the Andes, and 3) extreme precipitation from "super-cloudbursts" with implications for flashfloods and landslides in the Himalayas and in the Andes. A matrix of observational and modeling needs with traceability to key science questions is suggested.

  13. 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

  14. 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.

  15. Separation of Silver from a Zinc Sulfide Concentrate by a Co-smelting Process

    NASA Astrophysics Data System (ADS)

    Yang, Jian-Guang; Zhang, Xu-Liang; Yang, Jian-Ying

    2015-02-01

    The main purpose of this study is to characterize and separate silver from a zinc sulfide concentrate through co-smelting with lead oxide dust. This article reports the optimization of process parameters, such as flux composition, co-smelting temperature, flux dosage, and charging material compositions, on the silver separation rate and resultant zinc sulfide concentrate grade. A maximum silver recovery of 97.36%, zinc sulfide concentrate grade of 43.91%, and 98.25% crude lead enriched silver are obtained under the optimized condition of temperature 900°C, smelting duration 120 min, 27.5 wt.% zinc sulfide concentrate, and 15.0 wt.% lead oxide dust, flux composition . This co-smelting process was proven effective to separate silver from zinc sulfide concentrate and produce a higher grade zinc sulfide concentrate. Especially, it was found to be effective to separate some associated impurities from zinc sulfide concentrate, such as arsenic, cadmium, fluorine, and chlorine etc.

  16. A method for separating water soluble organics from a process stream by aqueous biphasic extraction

    SciTech Connect

    Chaiko, David J.; Mego, William A.

    1997-12-01

    The present invention relates to a method for separating water-miscible organic species from a process stream by aqueous biphasic extraction. In particular, the method includes extracting the organic species into a polymer-rich phase of an aqueous biphase system in which the process stream comprises the salt-rich phase, and, next, separating the polymer from the extracted organic species by contacting the loaded, polymer-rich phase with a water-immiscible organic phase. Alternatively, the polymer can be separated from the extracted organic species by raising the temperature of the loaded, polymer-rich phase above the cloud point, such that the polymer and the water-soluble organic species separate into two distinct aqueous phases. In either case, a substantially salt-free, concentrated aqueous solution containing the organic species is recovered.

  17. 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.

  18. 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…

  19. 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…

  20. [Application of membrane separation technology in extraction process of Chuanxiong Chatiao granules].

    PubMed

    Zhang, Liyan; Mei, Jixiong; Xie, Yu; Li, Menglin; Liu, Dejiang; He, Changqing

    2012-04-01

    To apply the membrane separation process in the concentration process of Chuanxiong Chatiao granules and to lay the foundation for its industrialized application. The type of membrane, the optimal pressure, the optimal temperature and the optimal detergent were selected by the single factor method. A comparative study was conducted between qualities of extracts from Chuanxiong Chatiao granules by new and traditional processes. The type of membrane was determined to be SMN-130A2350054. The optimal pressure was 1.7 MPa. The optimal temperature was 36 degrees C and the optimal detergent was 1% sodium polyphosphate. The qualities of extracts from Chuanxiong Chatiao granules by new and traditional processes showed no difference. The selected membrane separation process can effectively achieve concentration and save energy. The extracts from Chuanxiong Chatiao granules by the new process show no difference with traditional processes. Therefore, it provides basis for the industrialized application of Chuanxiong Chatiao granules.