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Sample records for cation-exchange regeneration brine

  1. Concentrations and environmental fate of Ra in cation-exchange regeneration brine waste disposed to septic tanks and accumulation in sludge, New Jersey Coastal Plain, USA

    International Nuclear Information System (INIS)

    Concentrations of Ra in liquid and solid wastes generated from 15 softeners treating domestic well waters from New Jersey Coastal Plain aquifers (where combined Ra (226Ra plus 228Ra) concentrations commonly exceed 0.185 Bq L-1) were determined. Softeners, when maintained, reduced combined Ra about 10-fold (-1). Combined Ra exceeded 0.185 Bq L-1 at 1 non-maintained system. Combined Ra was enriched in regeneration brine waste (maximum, 81.2 Bq L-1), but concentrations in septic-tank effluents receiving brine waste were less than in the untreated ground waters. The maximum combined Ra concentration in aquifer sands (40.7 Bq kg-1 dry weight) was less than that in sludge from the septic tanks (range, 84-363 Bq kg-1), indicating Ra accumulation in sludge from effluent. The combined Ra concentration in sludge from the homeowners' septic systems falls within the range reported for sludge samples from publicly owned treatment works within the region

  2. Denitrification of Spent Regenerated Brine Using Molasses

    OpenAIRE

    Tepuš, Brigita; Simonič, Marjana; Petrovič, Aleksandra; Filipič, Jasmina

    2014-01-01

    Spent BRINE from the regeneration of exhausted resins has to be properly treated before its disposal. The heterotrophic denitrification of regenerated brine was studied in present work. Molasses which served as a carbon source has until now not been applied during brine denitrification. The nitrate and nitrite consumptions were observed according to different ratios between total organic carbon and nitrate (TOC / NO3 ratios) and the influence of NaCl was studied during batch experiments. ...

  3. Photocatalytic reduction of nitrate using titanium dioxide for regeneration of ion exchange brine

    OpenAIRE

    Yang, Ting; Doudrick, Kyle; Westerhoff, Paul

    2012-01-01

    Nitrate is often removed from groundwater by ion exchange (IX) before its use as drinking water. Accumulation of nitrate in IX brine reduces the efficiency of IX regeneration and the useful life of the regeneration brine. For the first time, we present a strategy to photocatalytically reduce nitrate in IX brine, thereby extending the use of the brine. Titanium dioxide (Evonik P90), acting as photocatalyst, reduced nitrate effectively in both synthetic brines and sulfate-removed IX brine when ...

  4. Organometallic cation-exchanged phyllosilicates

    OpenAIRE

    Fleming, Shay

    1991-01-01

    Organotin (IV) complexes formed between 0 01 M dimethyltin dichloride solutions prepared at pH 2 6 and 4 0, and trimethyltin chloride prepared at pH 3 4, with Na- 119 montmori 1lonite clay have been characterised using Sn Mflssbauer spectroscopy, X-ray diffraction, thermogravimetric analysis and water sorption isotherms Following cation exchange, Mttssbauer spectroscopy identified two tin species in the dimethyltin (IV)-exchanged clay prepared at pH 2 6 A cis specie...

  5. Photocatalytic reduction of nitrate using titanium dioxide for regeneration of ion exchange brine.

    Science.gov (United States)

    Yang, Ting; Doudrick, Kyle; Westerhoff, Paul

    2013-03-01

    Nitrate is often removed from groundwater by ion exchange (IX) before its use as drinking water. Accumulation of nitrate in IX brine reduces the efficiency of IX regeneration and the useful life of the regeneration brine. For the first time, we present a strategy to photocatalytically reduce nitrate in IX brine, thereby extending the use of the brine. Titanium dioxide (Evonik P90), acting as photocatalyst, reduced nitrate effectively in both synthetic brines and sulfate-removed IX brine when formic acid (FA) was used as the hole scavenger (i.e., electron donor) and the initial FA to nitrate molar ratio (IFNR) was 5.6. Increasing the NaCl level in the synthetic brine slowed the nitrate reduction rate without affecting by-product selectivity of ammonium and gaseous N species (e.g., N(2), N(2)O). In a non-modified IX brine, nitrate removal was greatly inhibited owing to the presence of sulfate, which competed with nitrate for active surface sites on P90 and induced aggregation of P90 nanoparticles. After removing sulfate through barium sulfate precipitation, nitrate was effectively reduced; approximately 3.6 × 10(24) photons were required to reduce each mole of nitrate to 83% N Gases and 17% NH(4)(+). To make optimum use of FA and control the residual FA level in treated brine, the IFNR was varied. High IFNRs (e.g., 4, 5.6) were found to be more efficient for nitrate reduction but left higher residual FA in brine. IX column tests were performed to investigate the impact of residual FA for brine reuse. The residual FA in the brine did not significantly affect the nitrate removal capacity of IX resins, and formate contamination of treated water could be eliminated by rinsing with one bed volume of fresh brine. PMID:23276425

  6. Study on degradation of cation exchange resin for condensate polishing plant

    International Nuclear Information System (INIS)

    The degradation of condensate polisher resin might cause the deterioration of water chemistry in power plants. The cause of cation resin degradation was studied in laboratory tests which simulated actual operating condition in a condensate polishing plant. It was found that air-scrubbing and unregenerated storage accelerate the decomposition of the cation exchange resin. Decrease of air-scrubbing times and regenerated storage are suggested as countermeasures against cation exchange resin degradation. (author)

  7. Test procedure for cation exchange chromatography

    International Nuclear Information System (INIS)

    The purpose of this test plan is to demonstrate the synthesis of inorganic antimonate ion exchangers and compare their performance against the standard organic cation exchangers. Of particular interest is the degradation rate of both inorganic and organic cation exchangers. This degradation rate will be tracked by determining the ion exchange capacity and thermal stability as a function of time, radiation dose, and chemical reaction

  8. Cobalt 60 cation exchange with mexican clays

    International Nuclear Information System (INIS)

    Mexican clays can be used to remove radioactive elements from contaminated aqueous solutions. Cation exchange experiments were performed with 60 Co radioactive solution. In the present work the effect of contact time on the sorption of Co 2+ was studied. The contact time in hydrated montmorillonite was from 5 to 120 minutes and in dehydrated montmorillonite 5 to 1400 minutes. The Co 2+ uptake value was, in hydrated montmorillonite, between 0.3 to 0.85 m eq/g and in dehydrated montmorillonite, between 0.6 to 1.40 m eq/g. The experiments were done in a pH 5.1 to 5.7 and normal conditions. XRD patterns were used to characterize the samples. The crystallinity was determined by X-ray Diffraction and it was maintained before and after the cation exchange. DTA thermo grams showed the temperatures of the lost humidity and crystallization water. Finally, was observed that dehydrated montmorillonite adsorb more cobalt than hydrated montmorillonite. (Author)

  9. Cation-Exchange Equilibria with Fused Salts

    International Nuclear Information System (INIS)

    Solute distributions of alkali metal, alkaline- earth, transition metal, and actinide ions have been studied in fused salt-cation exchanger systems. The fused salts employed were alkali halides and nitrates. The cation exchangers used were natural zeolites, synthetic zeolites, high-porosity glasses, and molten oxide mixtures. The molten exchangers were composed of Na2O and B2O3 in various proportions. The relative quantities not only determined the exchanger capacity and electrolyte penetration but also produced distribution coefficients for a given solute which varied over several orders of magnitude. Moreover, they produced marked reversals in the selectivity series. Additional studies on the anion distributions, miscibility diagrams, vapour pressures and diffusion rates in these systems have elucidated the mechanisms involved and the relation of selectivity to solute properties, system thermodynamics, exchanger structure and available functional groups. In the region of high Na2O composition, the distribution coefficients for mono-, di- and trivalent cations in NaCl have not only the same order of selectivity found in Dowex 50-HCl systems but also similar values for the distribution coefficients. The results are summarized qualitatively and compared to behaviour in aqueous systems (Table VII). (author)

  10. Microscopic Theory of Cation Exchange in CdSe Nanocrystals

    OpenAIRE

    Ott, Florian D.; Spiegel, Leo L.; Norris, David J.; Erwin, Steven C.

    2014-01-01

    Although poorly understood, cation-exchange reactions are increasingly used to dope or transform colloidal semiconductor nanocrystals (quantum dots). We used density-functional theory and kinetic Monte Carlo simulations to develop a microscopic theory that explains structural, optical, and electronic changes observed experimentally in Ag-cation-exchanged CdSe nanocrystals. We find that Coulomb interactions, both between ionized impurities and with the polarized nanocrystal surface, play a key...

  11. Modeling cation exchange using EQ3/6

    International Nuclear Information System (INIS)

    Geochemical modeling codes must be able to predict solid-solution and ion-exchange behavior of zeolites and smectites in order to design and assess strategies for containing and cleaning up toxic and/or radioactive wastes. Cation-exchange and solid-solution models have been implemented in the EQ3/6 geochemical modeling package and used to predict the composition of clinoptilolite under a variety of conditions. Published free energies of cation exchange on clinoptilolite at 25 degrees C were combined with the calorimetric data for clinoptilolite to derive free energies of formation of the component end members of a solid solution in which mixing is allowed only on the exchange site. The solid-solution model and component end-member data were incorporated into EQ3/6 and its data base. An option to treat cation exchange independently of the solid-solution model was also developed and implemented in EQ3/6. This option allows the user to model mixed-phase exchangers, multisite exchangers, and systems in which the exchanger is not in overall equilibrium with the solution. Two open-quotes idealclose quotes cation-exchange conventions [Vanselow (mole fraction) and Gapon (equivalent fraction)] are currently implemented in the code. A description of the cation-exchange models and their implementation into EQ3/6 is presented, and the relationship between the exchange formalisms and the solid-solution models is discussed. The advantages and limitations of the models and currently available thermodynamic data are addressed by comparing cation-exchange compositions of clinoptilolites with (1) published binary exchange data; (2) compositions of coexisting clinoptilolites and formation waters at Yucca Mountain; and (3) experimental sorption isotherms of Cs and Sr on zeolitized tuff

  12. Denatured Thermodynamics of Proteins in Weak Cation-exchange Chromatography

    Institute of Scientific and Technical Information of China (English)

    LI Rong; CHEN Guo-Liang

    2003-01-01

    The thermostability of some proteins in weak cation-exchange chromatography was investigated at 20-80 ℃. The results show that there is a fixed thermal denaturation transition temperature for each protein. The appearance of the thermal transition temperature indicates that the conformations of the proteins are destroyed seriously. The thermal behavior of the proteins in weak cation-exchange and hydrophobic interaction chromatographies were compared in a wide temperature range. It was found that the proteins have a higher thermostability in a weak cation-exchange chromatography system. The thermodynamic parameters(ΔH0, ΔS0) of those proteins were determined by means of Vant Hoff relationship(lnk-1/T). According to standard entropy change(ΔS0), the conformational change of the proteins was judged in the chromatographic process. The linear relationships between ΔH0 and ΔS0 can be used to evaluate "compensation temperature"(β) at the protein denaturation and identify the identity of the protein retention mechanism in weak cation-exchange chromatography.

  13. Characterization of an aluminum pillared montmorillonite with cation exchange properties

    International Nuclear Information System (INIS)

    The methods of PIGE and XRF were used to determine the elemental composition and the structural formulae of a specially tailored PILC material during the steps of its preparation. The CEC, a crucial property for the characterization of a cation exchanger, was monitored through all stages of preparation. In addition, the charge carried by the pillars, a critical quantity of the pillaring process, was estimated. Exchange isotherms of strontium and cesium were performed through the use of radiotracers' exchange isotherms of 137Cs and 85Sr with typical γ-ray spectroscopy. These isotherms were of the Langmuir type and PILCs adsorption capacity was determined. The latter property was compared with the CEC determined by the elemental analysis and was found equal to the amount of the exchangeable interlamellar sodium ions. (author)

  14. Cation-exchange separation of uranium in dimethylsulphoxide medium.

    Science.gov (United States)

    Janauer, G E; Korkisch, J; Hubbard, S A

    1971-08-01

    Cation-exchange chromatography in a dimethylsulphoxide (DMSO) medium is a suitable means for separating uranium from metal ions, including copper, iron, nickel and molybdenum. Quantitative separations of uranium from 26 elements can best be effected on a column of Dowex 50W-X8 (200-400 mesh), using as the eluent a 20% v/v DMSO solution which is 0.6Min hydrochloric acid and 0.25M in sodium acetate. Only calcium is eluted with the uranium and all other elements studied are eluted either before or after uranium. The elution characteristics of uranium and of other metal ions were investigated with respect to changes in eluent and resin compositions. Separations were much less effective at higher concentrations of sodium ion or DMSO. None of the organic solvents methanol, ethanol, methyl glycol, acetone, dioxan or acetic acid was found to produce favourable separation conditions. Results with Dowex 50 resins of lower or higher cross-linkage were inferior to those obtained with the X8 resin. PMID:18960944

  15. Iridium containing honeycomb Delafossites by topotactic cation exchange.

    Science.gov (United States)

    Roudebush, John H; Ross, K A; Cava, R J

    2016-06-01

    We report the structure and magnetic properties of two new iridium-based honeycomb Delafossite compounds, Cu3NaIr2O6 and Cu3LiIr2O6, formed by a topotactic cation exchange reaction. The starting materials Na2IrO3 and Li2IrO3, which are based on layers of IrO6 octahedra in a honeycomb lattice separated by layers of alkali ions, are transformed to the title compounds by a topotactic exchange reaction through heating with CuCl below 450 °C; higher temperature reactions cause decomposition. The new compounds display dramatically different magnetic behavior from their parent compounds - Cu3NaIr2O6 has a ferromagnetic like magnetic transition at 10 K, while Cu3LiIr2O6 retains the antiferromagnetic transition temperature of its parent compound but displays significantly stronger dominance of antiferromagnetic coupling between spins. These results reveal that a surprising difference in the magnetic interactions between the magnetic Ir ions has been induced by a change in the non-magnetic interlayer species. A combination of neutron and X-ray powder diffraction is used for the structure refinement of Cu3NaIr2O6 and both compounds are compared to their parent materials. PMID:27147423

  16. Cation exchange interaction between antibiotic ciprofloxacin and montmorillonite

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Chih-Jen [Department of Earth Sciences, National Cheng Kung University, 1 University Road, Tainan 70101, Taiwan (China); Department of Geosciences, National Taiwan University, Taipei 10617, Taiwan (China); Li, Zhaohui, E-mail: li@uwp.edu [Department of Earth Sciences, National Cheng Kung University, 1 University Road, Tainan 70101, Taiwan (China); Department of Geosciences, University of Wisconsin - Parkside, Kenosha, WI 53144 (United States); Jiang, Wei-Teh, E-mail: atwtj@mail.ncku.edu.tw [Department of Earth Sciences, National Cheng Kung University, 1 University Road, Tainan 70101, Taiwan (China); Jean, Jiin-Shuh; Liu, Chia-Chuan [Department of Earth Sciences, National Cheng Kung University, 1 University Road, Tainan 70101, Taiwan (China)

    2010-11-15

    Exploring the interactions between antibiotics and soils/minerals is of great importance in resolving their fate, transport, and elimination in the environment due to their frequent detection in wastewater, river water, sewage sludge and soils. This study focused on determining the adsorption properties and mechanisms of interaction between antibiotic ciprofloxacin and montmorillonite (SAz-1), a swelling dioctahedral mineral with Ca{sup 2+} as the main interlayer cation. In acidic and neutral aqueous solutions, a stoichiometric exchange between ciprofloxacin and interlayer cations yielded an adsorption capacity as high as 330 mg/g, corresponding to 1.0 mmol/g. When solution pH was above its pK{sub a2} (8.7), adsorption of ciprofloxacin was greatly reduced due to the net repulsion between the negatively charged clay surfaces and the ciprofloxacin anion. The uptake of ciprofloxacin expanded the basal spacing (d{sub 001}) of montmorillonite from 15.04 to 17.23 A near its adsorption capacity, confirming cation exchange within the interlayers in addition to surface adsorption. Fourier transform infrared results further suggested that the protonated amine group of ciprofloxacin in its cationic form was electrostatically attracted to negatively charged sites of clay surfaces, and that the carboxylic acid group was hydrogen bonded to the basal oxygen atoms of the silicate layers. The results indicate that montmorillonite is an effective sorbent to remove ciprofloxacin from water.

  17. Cation exchange interaction between antibiotic ciprofloxacin and montmorillonite

    International Nuclear Information System (INIS)

    Exploring the interactions between antibiotics and soils/minerals is of great importance in resolving their fate, transport, and elimination in the environment due to their frequent detection in wastewater, river water, sewage sludge and soils. This study focused on determining the adsorption properties and mechanisms of interaction between antibiotic ciprofloxacin and montmorillonite (SAz-1), a swelling dioctahedral mineral with Ca2+ as the main interlayer cation. In acidic and neutral aqueous solutions, a stoichiometric exchange between ciprofloxacin and interlayer cations yielded an adsorption capacity as high as 330 mg/g, corresponding to 1.0 mmol/g. When solution pH was above its pKa2 (8.7), adsorption of ciprofloxacin was greatly reduced due to the net repulsion between the negatively charged clay surfaces and the ciprofloxacin anion. The uptake of ciprofloxacin expanded the basal spacing (d001) of montmorillonite from 15.04 to 17.23 A near its adsorption capacity, confirming cation exchange within the interlayers in addition to surface adsorption. Fourier transform infrared results further suggested that the protonated amine group of ciprofloxacin in its cationic form was electrostatically attracted to negatively charged sites of clay surfaces, and that the carboxylic acid group was hydrogen bonded to the basal oxygen atoms of the silicate layers. The results indicate that montmorillonite is an effective sorbent to remove ciprofloxacin from water.

  18. Adsorption behavior and mechanism of cadmium on strong-acid cation exchange resin

    Institute of Scientific and Technical Information of China (English)

    WANG Fei; WANG Lian-jun; LI Jian-sheng; SUN Xiu-yun; HAN Wei-qing

    2009-01-01

    The adsorption behavior of Cd2+ on 001×7 strong-acid cation exchange resin was studied with the static adsorption method. The adsorption process was analyzed from thermodynamics and kinetics aspects. The influences of experimental parameters such as pH, temperature, initial concentration and adsorption rate were investigated. The experimental results show that in the studied concentration range, 001×7 resin has a good sorption ability for Cd2+, and the equilibrium adsorption data fit to Freundlich isotherms. The adsorption is an exothermic process which runs spontaneously. Kinetic analysis shows that the adsorption rate is mainly governed by liquid film diffusion. The best adsorption condition is pH 4-5. The saturated resin can be regenerated by 3 mol/L nitric acid, and the desorption efficiency is over 98%. The maximal static saturated adsorption capacity is 355 mg/g (wet resin) at 293 K. The adsorption mechanism of Cd2+ on 001×7 resin was discussed based on IR spectra.

  19. Black Carbon Increases Cation Exchange Capacity in Soils

    International Nuclear Information System (INIS)

    Black Carbon (BC) may significantly affect nutrient retention and play a key role in a wide range of biogeochemical processes in soils, especially for nutrient cycling. Anthrosols from the Brazilian Amazon (ages between 600 and 8700 yr BP) with high contents of biomass-derived BC had greater potential cation exchange capacity (CEC measured at pH 7) per unit organic C than adjacent soils with low BC contents. Synchrotron-based near edge X-ray absorption fine structure (NEXAFS) spectroscopy coupled with scanning transmission X-ray microscopy (STXM) techniques explained the source of the higher surface charge of BC compared with non-BC by mapping cross-sectional areas of BC particles with diameters of 10 to 50 (micro)m for C forms. The largest cross-sectional areas consisted of highly aromatic or only slightly oxidized organic C most likely originating from the BC itself with a characteristic peak at 286.1 eV, which could not be found in humic substance extracts, bacteria or fungi. Oxidation significantly increased from the core of BC particles to their surfaces as shown by the ratio of carboxyl-C/aromatic-C. Spotted and non-continuous distribution patterns of highly oxidized C functional groups with distinctly different chemical signatures on BC particle surfaces (peak shift at 286.1 eV to a higher energy of 286.7 eV) indicated that non-BC may be adsorbed on the surfaces of BC particles creating highly oxidized surface. As a consequence of both oxidation of the BC particles themselves and adsorption of organic matter to BC surfaces, the charge density (potential CEC per unit surface area) was greater in BC-rich Anthrosols than adjacent soils. Additionally, a high specific surface area was attributable to the presence of BC, which may contribute to the high CEC found in soils that are rich in BC

  20. Method for in situ determination cation exchange capacities of subsurface formations

    International Nuclear Information System (INIS)

    A method is disclosed for the in situ examination of each subsurface formation penetrated by a borehole to ascertain the cation exchange capacity of such formations within a geological region. Natural γ ray logging is used to develop signals functionally related to the total γ radiation and to the potassium-40, uranium and thorium energy-band radiations. A first borehole is traversed by a potential γ ray spectrometer to provide selected measurements of natural γ radiation. Core samples are taken from the logged formation and laboratory tests performed to determine the cation exchange capacity thereof. The cation exchange capacities thus are developed then correlated with selected parameters provided by the γ ray spectrometer to establish functional relationships. Cation exchange capacities of formations in subsequent boreholes within the region are then determined in situ by use of the natural γ ray spectrometer and these established relationships. (author)

  1. Americium and samarium determination in aqueous solutions after separation by cation-exchange

    International Nuclear Information System (INIS)

    The concentration of trivalent americium and samarium in aqueous samples has been determined by means of alpha-radiometry and UV-Vis photometry, respectively, after chemical separation and pre-concentration of the elements by cation-exchange using Chelex-100 resin. Method calibration was performed using americium (241Am) and samarium standard solutions and resulted in a high chemical recovery for cation-exchange. Regarding, the effect of physicochemical parameters (e.g. pH, salinity, competitive cations and colloidal species) on the separation recovery of the trivalent elements from aqueous solutions by cation-exchange has also been investigated. The investigation was performed to evaluate the applicability of cation-exchange as separation and pre-concentration method prior to the quantitative analysis of trivalent f-elements in water samples, and has shown that the method could be successfully applied to waters with relatively low dissolved solid content. (author)

  2. Simultaneous Determination of Anions and Cations in Natural Water by Ion-exclusion/Cation-exchange Chromatography with a Weakly Acidic Cation-exchange Resin Column

    International Nuclear Information System (INIS)

    The simultaneous determination of anions (SO4 2-, Cl-, and NO3 -) and cations (Na+, NH4+, K+, Mg2+, and Ca2+) in natural water obtained by Nakdong River waters system in Korea were performed by ion-exclusion/cation exchange chromatography with conductimetric detection. The stationary phase was a polymethacrylate-based weakly acidic cation-exchange resin column in the H+-form and a weak-acid eluent. When using only a 1.4 mM sulfosalicylic acid/6 mM 18-crown-6 ether as an eluent, good resolution of both anions and cations, minimum time required for the separation, and satisfactory detection sensitivity were obtained in a reasonable time. The method was successfully applied to the simultaneous determination of anions and cations in natural waters

  3. Simultaneous Determination of Anions and Cations in Natural Water by Ion-exclusion/Cation-exchange Chromatography with a Weakly Acidic Cation-exchange Resin Column

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kwang Pill; Choi, Seong Ho; Park, Yu Chul; Bae, Zun Ung; Lee, Mu Sang; Lee, Sang Hak; Chang, Hye Yong [Graduate School, Kyungpook National University, Daegu (Korea, Republic of); Kwon, Se Mok [Ulsan City Health and Environmental Research Institute, Ulsan (Korea, Republic of); Tanaka, Kazuhiko [National Industrial Research Institute of Nagoya, Nagoya (Japan)

    2003-09-15

    The simultaneous determination of anions (SO{sub 4} {sup 2-}, Cl{sup -}, and NO{sub 3} {sup -}) and cations (Na{sup +}, NH{sup 4+}, K{sup +}, Mg{sup 2+}, and Ca{sup 2+}) in natural water obtained by Nakdong River waters system in Korea were performed by ion-exclusion/cation exchange chromatography with conductimetric detection. The stationary phase was a polymethacrylate-based weakly acidic cation-exchange resin column in the H{sup +}-form and a weak-acid eluent. When using only a 1.4 mM sulfosalicylic acid/6 mM 18-crown-6 ether as an eluent, good resolution of both anions and cations, minimum time required for the separation, and satisfactory detection sensitivity were obtained in a reasonable time. The method was successfully applied to the simultaneous determination of anions and cations in natural waters.

  4. Sulfonation Process and Desalination Effect of Polystyrene/PVDF Semi-Interpenetrating Polymer Network Cation Exchange Membrane

    OpenAIRE

    Yin-lin Lei; Yun-jie Luo; Fei Chen; Le-he Mei

    2014-01-01

    With the classical sulfonation method of polystyrene-based strongly acidic cation exchange resins, polystyrene/polyvinylidene fluoride (PVDF) alloy particles were sulfonated to obtain a cation exchange resin, which was then directly thermoformed to prepare a semi-interpenetrating polymer network (semi-IPN) cation exchange membrane. The effects of the swelling agent, sulfonation time and temperature and the relative contents of polystyrene and divinylbenzene (DVB) in the alloy particles on the...

  5. Atomistic understanding of cation exchange in PbS nanocrystals using simulations with pseudoligands

    Science.gov (United States)

    Fan, Zhaochuan; Lin, Li-Chiang; Buijs, Wim; Vlugt, Thijs J. H.; van Huis, Marijn A.

    2016-05-01

    Cation exchange is a powerful tool for the synthesis of nanostructures such as core-shell nanocrystals, however, the underlying mechanism is poorly understood. Interactions of cations with ligands and solvent molecules are systematically ignored in simulations. Here, we introduce the concept of pseudoligands to incorporate cation-ligand-solvent interactions in molecular dynamics. This leads to excellent agreement with experimental data on cation exchange of PbS nanocrystals, whereby Pb ions are partially replaced by Cd ions from solution. The temperature and the ligand-type control the exchange rate and equilibrium composition of cations in the nanocrystal. Our simulations reveal that Pb ions are kicked out by exchanged Cd interstitials and migrate through interstitial sites, aided by local relaxations at core-shell interfaces and point defects. We also predict that high-pressure conditions facilitate strongly enhanced cation exchange reactions at elevated temperatures. Our approach is easily extendable to other semiconductor compounds and to other families of nanocrystals.

  6. Nongeminate Radiative Recombination of Free Charges in Cation-Exchanged PbS Quantum Dot Films

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, Ashley R.; Beard, Matthew C.; Johnson, Justin C.

    2016-06-01

    Using photoluminescence (PL) spectroscopy we explore the radiative recombination pathways in PbS quantum dots (QDs) synthesized by two methods. We compare conventionally synthesized PbS from a PbO precursor to PbS synthesized using cation-exchange from CdS QDs. We show that strongly coupled films of PbS QDs from the cation-exchange luminesce with significant efficiency at room temperature. This is in stark contrast to conventional PbS QDs, which have exceedingly weak room temperature emission. Moreover, the power dependence of the emission is quadratic, indicating bimolecular radiative recombination that is reasonably competitive with trap-assisted recombination, a feature previously unreported in coupled PbS QD films. We interpret these results in terms of a greatly reduced defect concentration for cation-exchanged QDs that mitigates the influence of trap-assisted recombination. Cation-exchanged QDs have recently been employed in highly efficient and air-stable lead chalcogenide QD devices, and the reduced number of trap states inferred here may lead to improved current collection and higher open circuit voltage.

  7. Sulfonation Process and Desalination Effect of Polystyrene/PVDF Semi-Interpenetrating Polymer Network Cation Exchange Membrane

    Directory of Open Access Journals (Sweden)

    Yin-lin Lei

    2014-07-01

    Full Text Available With the classical sulfonation method of polystyrene-based strongly acidic cation exchange resins, polystyrene/polyvinylidene fluoride (PVDF alloy particles were sulfonated to obtain a cation exchange resin, which was then directly thermoformed to prepare a semi-interpenetrating polymer network (semi-IPN cation exchange membrane. The effects of the swelling agent, sulfonation time and temperature and the relative contents of polystyrene and divinylbenzene (DVB in the alloy particles on the feasibility of the membrane formation are discussed. The results indicate that a favorable sulfonation degree above 80% and a suitable ion exchange capacity of 1.5–2.4 mmol/g can be gained, with concentrated sulfuric acid as the sulfonation agent and 1,2-dichloroethane as the swelling agent. The running electrical resistance and desalination effect of the prepared cation exchange membrane were measured in a pilot-scale electrodialyser and not only obviously exceeded a commercial heterogeneous cation exchange membrane, but was also very close to a commercial homogenous membrane. In this way, the authors have combined the classical sulfonation method of polystyrene-based cation exchange resins with the traditional thermoforming manufacturing process of heterogeneous cation exchange membranes, to successfully develop a novel, low-price, but relatively high-performance polystyrene/PVDF cation exchange membrane with the semi-IPN structure.

  8. Selective separation of sodium ions from a mixture with phenylalanine by Donnan dialysis with a profiled sulfogroup cation exchange membrane

    Science.gov (United States)

    Vasil'eva, V. I.; Goleva, E. A.

    2013-11-01

    The possibility of separating ions of metal from a mixture with ampholyte (an amino acid) by Donnan dialysis with an MK-40 sulfogroup cation exchange membrane is demonstrated. Conditions ensuring the selectivity and intensity of the mass transfer of sodium ions from a mixture with bipolar phenylalanine ions into a diffusate containing hydrochloric acid through a cation exchange membrane are found.

  9. HTGR fuel development: loading of uranium on carboxylic acid cation-exchange resins using solvent extraction of nitrate

    International Nuclear Information System (INIS)

    The reference fuel kernel for recycle of 233U to HTGR's (High-Temperature Gas-Cooled Reactors) is prepared by loading carboxylic acid cation-exchange resins with uranium and carbonizing at controlled conditions. The purified 233UO2(NO3)2 solution from a fuel reprocessing plant contains excess HNO3 (NO3-/U ratio of approximately 2.2). The reference flowsheet for a 233U recycle fuel facility at Oak Ridge uses solvent extraction of nitrate by a 0.3 M secondary amine in a hydrocarbon diluent to prepare acid-deficient uranyl nitrate. This nitrate extraction, along with resin loading and amine regeneration steps, was demonstrated in 14 runs. No significant operating difficulties were encountered. The process is controlled via in-line pH measurements for the acid-deficient uranyl nitrate solutions. Information was developed on pH values for uranyl nitrate solution vs NO3-/U mole ratios, resin loading kinetics, resin drying requirements, and other resin loading process parameters. Calculations made to estimate the capacities of equipment that is geometrically safe with respect to control of nuclear criticality indicate 100 kg/day or more of uranium for single nitrate extraction lines with one continuous resin loading contactor or four batch loading contactors. (auth)

  10. Separation of Clay Minerals from Host Sediments Using Cation Exchange Resins

    Institute of Scientific and Technical Information of China (English)

    I.S. Ismael; H.M. Baioumy

    2003-01-01

    Classic physical and chemical treatments applied to separating clay minerals from the host sediments are often difficult or aggressive for clay minerals. A technique using cation exchange resins (amberlite IRC-50H and amberlite IR-120) is used to separate clay minerals from the host sediments. The technique is based on the exchange of cations in the minerals that may be associated clay minerals in sediments,such as Ca and Mg from dolomite; Ca from calcite,gypsum and francolite with cations carried by resin radicals. The associated minerals such as gypsum,calcite,dolomite and francolite are removed in descending order. Separation of clay minerals using cation exchange resins is less aggressive than that by other classic treatments.The efficiency of amberlite IRC-50H in the removal of associated minerals is greater than that of amberlite IR-120.

  11. Characterization and cation exchange capacity of seeds of Ziziphus spina-christi

    Directory of Open Access Journals (Sweden)

    Shadia M. Sirry

    2014-09-01

    Full Text Available There are several naturally existing materials have ability to utilize as ion-exchangers. Most of these materials are by-products of waste material from industry or agriculture. Agriculture ion exchange materials include: lemon orange, grapefruit, apple, peas, broad bean, and meddler peels, kernel core, and grape skins. This research deals with the utilization of agriculture waste biomass of napak seed as natural cation exchanger for removal of cationic pollutant from aqueous solution. Methylene blue dye method was used to determine the cation exchange capacity of the stone and it was characterized by IR and TGA methods. The results showed that the highest dye sorption capacity was found at pH 7, the equilibrium time was 60 min, sorbent dose = 0.1g, particle size 177μm and methylene blue concentration range 10-50 ppm. The equilibrium sorption data were analyzed by Langmuir and Freundlich isotherm models.

  12. Biochemical characterization of Extracellular Polymeric Substances extracted from an intertidal mudflat using a cation exchange resin.

    OpenAIRE

    Pierre, Guillaume; Graber, Marianne; Orvain, Francis; Dupuy, Christine; Maugard, Thierry

    2010-01-01

    The biochemical characterization of Extracellular Polymeric Substances (EPS) excreted in a European intertidal mudflat (Marennes-Oléron Bay) was performed. Experiments were carried out for the first time in situ, by using an improved extraction recently developed. This innovative procedure, using a cation exchange resin (Dowex), allows separating precisely different fractions of EPS, especially pure bound EPS. Moreover, it avoids the contamination of EPS fractions by residual and intracellula...

  13. Effects of Experimental Conditions on Extraction Yield of Extracellular Polymeric Substances by Cation Exchange Resin

    OpenAIRE

    Jinwoo Cho; Hermanowicz, Slawomir W; Jin Hur

    2012-01-01

    Effects of experimental conditions on the yield of extracellular polymeric substances (EPSs) extraction by cation exchange resin (CER) were investigated using activated sludge flocs. The experimental variables included resin dose, extraction time, sample dilution, and storage time. An empirical model was proposed to describe the kinetics of extraction process. The extraction yield increases with the extraction time and CER dose until it reached the maximum amount of EPS extraction. The maximu...

  14. Cation-exchange membranes: comparison of homopolymer, block copolymer, and heterogeneous membranes

    Czech Academy of Sciences Publication Activity Database

    Schauer, Jan; Llanos, J.; Žitka, Jan; Hnát, J.; Bouzek, K.

    2012-01-01

    Roč. 124, SI 1 (2012), E66-E72. ISSN 0021-8995 R&D Projects: GA MŠk(CZ) 7E08005 EU Projects: European Commission(XE) 212903 - WELTEMP Institutional research plan: CEZ:AV0Z40500505 Keywords : cation-exchange membranes * poly(phenylene oxide) * poly(ether ketones) Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.395, year: 2012

  15. Aspects of the super-equivalent sorption of glycine by cation exchanger KU-2-8

    Science.gov (United States)

    Khokhlova, O. N.; Khokhlov, V. Yu.; Trunaeva, E. S.; Nechaeva, L. S.

    2016-07-01

    The structure formed in a sorbent during the super-equivalent sorption of glycine by cation exchanger KU-2-8 is optimized via quantum chemical simulation. The differential thermodynamic characteristics of ion exchange and super-equivalent sorption in the studied system are calculated using a thermodynamic approach that allows us to describe the simultaneous exchange and super-equivalent sorption of compounds by ion-exchangers.

  16. Tuning light emission of PbS nanocrystals from infrared to visible range by cation exchange

    Science.gov (United States)

    Binetti, Enrico; Striccoli, Marinella; Sibillano, Teresa; Giannini, Cinzia; Brescia, Rosaria; Falqui, Andrea; Comparelli, Roberto; Corricelli, Michela; Tommasi, Raffaele; Agostiano, Angela; Curri, M. Lucia

    2015-10-01

    Colloidal semiconductor nanocrystals, with intense and sharp-line emission between red and near-infrared spectral regions, are of great interest for optoelectronic and bio-imaging applications. The growth of an inorganic passivation layer on nanocrystal surfaces is a common strategy to improve their chemical and optical stability and their photoluminescence quantum yield. In particular, cation exchange is a suitable approach for shell growth at the expense of the nanocrystal core size. Here, the cation exchange process is used to promote the formation of a CdS passivation layer on the surface of very small PbS nanocrystals (2.3 nm in diameter), blue shifting their optical spectra and yielding luminescent and stable nanostructures emitting in the range of 700-850 nm. Structural, morphological and compositional investigation confirms the nanocrystal size contraction after the cation-exchange process, while the PbS rock-salt crystalline phase is retained. Absorption and photoluminescence spectroscopy demonstrate the growth of a passivation layer with a decrease of the PbS core size, as inferred by the blue-shift of the excitonic peaks. The surface passivation strongly increases the photoluminescence intensity and the excited state lifetime. In addition, the nanocrystals reveal increased stability against oxidation over time. Thanks to their absorption and emission spectral range and the slow recombination dynamics, such highly luminescent nano-objects can find interesting applications in sensitized photovoltaic cells and light-emitting devices.

  17. Tuning light emission of PbS nanocrystals from infrared to visible range by cation exchange

    KAUST Repository

    Binetti, Enrico

    2015-10-27

    Colloidal semiconductor nanocrystals, with intense and sharp-line emission between red and near-infrared spectral regions, are of great interest for optoelectronic and bio-imaging applications. The growth of an inorganic passivation layer on nanocrystal surfaces is a common strategy to improve their chemical and optical stability and their photoluminescence quantum yield. In particular, cation exchange is a suitable approach for shell growth at the expense of the nanocrystal core size. Here, the cation exchange process is used to promote the formation of a CdS passivation layer on the surface of very small PbS nanocrystals (2.3 nm in diameter), blue shifting their optical spectra and yielding luminescent and stable nanostructures emitting in the range of 700–850 nm. Structural, morphological and compositional investigation confirms the nanocrystal size contraction after the cation-exchange process, while the PbS rock-salt crystalline phase is retained. Absorption and photoluminescence spectroscopy demonstrate the growth of a passivation layer with a decrease of the PbS core size, as inferred by the blue-shift of the excitonic peaks. The surface passivation strongly increases the photoluminescence intensity and the excited state lifetime. In addition, the nanocrystals reveal increased stability against oxidation over time. Thanks to their absorption and emission spectral range and the slow recombination dynamics, such highly luminescent nano-objects can find interesting applications in sensitized photovoltaic cells and light-emitting devices.

  18. Esterification of oleic acid with ethanol catalyzed by sulfonated cation exchange resin: Experimental and kinetic studies

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Esterification of oleic acid with ethanol was investigated in the presence of sulfonated cation exchange resin. • We studied kinetic model of the esterification of oleic acid with ethanol according to experimental data. • The proposed kinetic model can well predict oleic acid conversion. - Abstract: This paper investigated the effects of ethanol to oleic acid molar ratio, reaction temperature, catalyst loading, water content and catalyst recycling on sulfonated cation exchange resin in a stirred batch reactor under atmospheric pressure. When the esterification was carried out with an ethanol to oleic acid (42.4 g) molar ratio of 9:1, reflux of ethanol at 82 °C, 20 g of catalyst and 8 h of reaction time, the oleic acid conversion rate reached approximately 93%. A pseudo-homogeneous kinetic model for describing the esterification of oleic acid with ethanol by the sulfonated cation exchange resin was developed on the basis of laboratorial results. The kinetic model can well predict the oleic acid conversion

  19. Atomistic understanding of cation exchange in PbS nanocrystals using simulations with pseudoligands

    Science.gov (United States)

    Fan, Zhaochuan; Lin, Li-Chiang; Buijs, Wim; Vlugt, Thijs J. H.; van Huis, Marijn A.

    2016-01-01

    Cation exchange is a powerful tool for the synthesis of nanostructures such as core–shell nanocrystals, however, the underlying mechanism is poorly understood. Interactions of cations with ligands and solvent molecules are systematically ignored in simulations. Here, we introduce the concept of pseudoligands to incorporate cation-ligand-solvent interactions in molecular dynamics. This leads to excellent agreement with experimental data on cation exchange of PbS nanocrystals, whereby Pb ions are partially replaced by Cd ions from solution. The temperature and the ligand-type control the exchange rate and equilibrium composition of cations in the nanocrystal. Our simulations reveal that Pb ions are kicked out by exchanged Cd interstitials and migrate through interstitial sites, aided by local relaxations at core–shell interfaces and point defects. We also predict that high-pressure conditions facilitate strongly enhanced cation exchange reactions at elevated temperatures. Our approach is easily extendable to other semiconductor compounds and to other families of nanocrystals. PMID:27160371

  20. Radiation stability of macro-porous and gel-type cation exchangers

    International Nuclear Information System (INIS)

    Macro-porous cation exchange resin Dianion CPK-08 and gel-type cation exchange resin Dowex 50WX8 were irradiated with γ-rays from 60Co, while soaked in distilled water, 0.5 M HNO3 or 4 M HNO3, and the ion-exchange properties, such as strong- and weak-acid capacities, moisture content and wet resin volume, were examined in relation to absorbed dose. There was no appreciable difference between the radiation stabilities of the two cation exchangers. Increase of HNO3 concentration reduced the loss of strong-acid capacity and increased the decross-linkage and the weak-acid capacity. Elution characteristics of 137Cs and 99Sr from columns packed with γ-irradiated resin were examined and the column distribution ratio of these radionuclides and the theoretical plate number were calculated. These values decreased with the increase of absorbed dose. Dianion CPK-08 was packed into a pressurized column and irradiated with γ-rays at a dose rate of 2x1O6 R/hr, while water was passed through the column at a constant flow rate. The greatest change in the resin properties was observed at an upper stream position from the position of the highest radiation dose of 2x106 R/hr. (T.G.)

  1. A cation exchange model to describe Cs + sorption at high ionic strength in subsurface sediments at Hanford site, USA

    Science.gov (United States)

    Liu, Chongxuan; Zachara, John M.; Smith, Steve C.

    2004-02-01

    A theoretical and experimental study of cation exchange in high ionic strength electrolytes was performed using pristine subsurface sediments from the U.S. Department of Energy Hanford site. These sediments are representative of the site contaminated sediments impacted by release of high level waste (HLW) solutions containing 137Cs + in NaNO 3 brine. The binary exchange behavior of Cs +-Na +, Cs +-K +, and Na +-K + was measured over a range in electrolyte concentration. Vanselow selectivity coefficients ( Kv) that were calculated from the experimental data using Pitzer model ion activity corrections for aqueous species showed monotonic increases with increasing electrolyte concentrations. The influence of electrolyte concentration was greater on the exchange of Na +-Cs + than K +-Cs +, an observation consistent with the differences in ion hydration energy of the exchanging cations. A previously developed two-site ion exchange model [Geochimica et Cosmochimica Acta 66 (2002) 193] was modified to include solvent (water) activity changes in the exchanger phase through application of the Gibbs-Duhem equation. This water activity-corrected model well described the ionic strength effect on binary Cs + exchange, and was extended to the ternary exchange system of Cs +-Na +-K + on the pristine sediment. The model was also used to predict 137Cs + distribution between sediment and aqueous phase ( Kd) beneath a leaked HLW tank in Hanfordd's S-SX tank using the analytical aqueous data from the field and the binary ion exchange coefficients for the pristine sediment. The Kd predictions closely followed the trend in the field data and were improved by consideration of water activity effects that were considerable in certain regions of the vadose zone plume.

  2. Impact of sediment-seawater cation exchange on Himalayan chemical weathering fluxes

    Science.gov (United States)

    Lupker, Maarten; France-Lanord, Christian; Lartiges, Bruno

    2016-08-01

    Continental-scale chemical weathering budgets are commonly assessed based on the flux of dissolved elements carried by large rivers to the oceans. However, the interaction between sediments and seawater in estuaries can lead to additional cation exchange fluxes that have been very poorly constrained so far. We constrained the magnitude of cation exchange fluxes from the Ganga-Brahmaputra river system based on cation exchange capacity (CEC) measurements of riverine sediments. CEC values of sediments are variable throughout the river water column as a result of hydrological sorting of minerals with depth that control grain sizes and surface area. The average CEC of the integrated sediment load of the Ganga-Brahmaputra is estimated ca. 6.5 meq 100 g-1. The cationic charge of sediments in the river is dominated by bivalent ions Ca2+ (76 %) and Mg2+ (16 %) followed by monovalent K+ (6 %) and Na+ (2 %), and the relative proportion of these ions is constant among all samples and both rivers. Assuming a total exchange of exchangeable Ca2+ for marine Na+ yields a maximal additional Ca2+ flux of 28 × 109 mol yr-1 of calcium to the ocean, which represents an increase of ca. 6 % of the actual river dissolved Ca2+ flux. In the more likely event that only a fraction of the adsorbed riverine Ca2+ is exchanged, not only for marine Na+ but also Mg2+ and K+, estuarine cation exchange for the Ganga-Brahmaputra is responsible for an additional Ca2+ flux of 23 × 109 mol yr-1, while ca. 27 × 109 mol yr-1 of Na+, 8 × 109 mol yr-1 of Mg2+ and 4 × 109 mol yr-1 of K+ are re-absorbed in the estuaries. This represents an additional riverine Ca2+ flux to the ocean of 5 % compared to the measured dissolved flux. About 15 % of the dissolved Na+ flux, 8 % of the dissolved K+ flux and 4 % of the Mg2+ are reabsorbed by the sediments in the estuaries. The impact of estuarine sediment-seawater cation exchange appears to be limited when evaluated in the context of the long-term carbon cycle and

  3. A fast method for the determination of Sr-90 in liquid milk by solid phase extraction with cryptand 222 on cation exchange resin

    International Nuclear Information System (INIS)

    A method for determining the activity of Sr-90 in liquid milk samples that does not require the usual drying, ashing, acid leaching and precipitation procedures is described. Two solid phase extractants are used, namely: Cryptand 222 bound to a cation exchange resin, and Eichrome Industries' Sr.Spec Resin trademark. These are applied respectively to extract Sr-90 from the milk and to isolate it in a form suitable for measurement by low-level liquid scintillation counting. The results of analyses of 1 liter milk samples contaminated with a known activity of Sr-90 agreed well with the expected values. It was also found that Sr.Spec Resin trademark can be regenerated and re-used several times. As the method requires only minimal operator skill and time, many samples can be analyzed simultaneously. (orig.)

  4. Cation exchange abilities of nanocomposites based on ion exchange resin and zirconium hydrophosphate

    International Nuclear Information System (INIS)

    A modification of cation-exchange resin with nanoparticles of zirconium hydrophosphate leads to the synergism of ion-exchange properties. The exchange of Cu2+→H+ shows that the nanocomposite ion exchangers demonstrate a high affinity to d-metal ions due to the polymer matrix, as well as to the inorganic component. The best characteristics are obtained for materials containing spherical particles of zirconium hydrophosphate with a diameter of (1.4-1.7) x 10-8 m, these aggregates being the most porous.

  5. Determination of organoarsenic species in marine samples using gradient elution cation exchange HPLC-ICP-MS

    DEFF Research Database (Denmark)

    Sloth, Jens Jørgen; Larsen, Erik Huusfeldt; Julshamn, Kåre

    2003-01-01

    A method for the determination of arsenic species in marine samples using high performance liquid chromatography coupled to inductively coupled mass spectrometry (HPLC-ICP-MS) has been developed. Cation exchange HPLC with gradient elution using pyridine formate as the mobile phase was employed for...... the separation of a large number of arsenicals that occurred in the samples. The arsenic species were extracted using a 50% (v/v) methanol-water mixture and mechanical agitation overnight. The effect of the sample matrix on HPLC retention time was investigated and showed a dramatic effect for...

  6. Refolding of Denatured/Reduced Lysozyme Using Weak-Cation Exchange Chromatography

    Institute of Scientific and Technical Information of China (English)

    Yan WANG; Bo Lin GONG; Xin Du GENG

    2003-01-01

    Oxidative refolding of the denatured/reduced lysozyme was investigated by using weak-cation exchange chromatography (WCX). The stationary phase of WCX binds to the reduced lysozyme and prevented it from forming intermolecular aggregates. At the same time urea and ammonium sulfate were added to the mobile phase to increase the elution strength for lysozyme. Ammonium sulfate can more stabilize the native protein than a common eluting agent, sodium chloride. Refolding of lysozyme by using this WCX is successfully. It was simply carried out to obtain a completely and correctly refolding of the denatured lysozyme at high concentration of 20.0 mg/mL.

  7. Cation Exchange in Dynamic 3D Porous Magnets: Improvement of the Physical Properties.

    Science.gov (United States)

    Grancha, Thais; Acosta, Alvaro; Cano, Joan; Ferrando-Soria, Jesús; Seoane, Beatriz; Gascon, Jorge; Pasán, Jorge; Armentano, Donatella; Pardo, Emilio

    2015-11-16

    We report two novel three-dimensional porous coordination polymers (PCPs) of formulas Li4{Mn4[Cu2(Me3mpba)2]3}·68H2O (2) and K4{Mn4[Cu2(Me3mpba)2]3}·69H2O (3) obtained-via alkali cation exchange in a single-crystal to single-crystal process-from the earlier reported anionic manganese(II)-copper(II) PCP of formula Na4{Mn4[Cu2(Me3mpba)2]3}·60H2O (1) [Me3mpba(4-) = N,N'-2,4,6-trimethyl-1,3-phenylenebis(oxamate)]. This postsynthetic process succeeds where the direct synthesis in solution from the corresponding building blocks fails and affords significantly more robust PCPs with enhanced magnetic properties [long-range 3D magnetic ordering temperatures for the dehydrated phases (1'-3') of 2.0 (1'), 12.0 (2'), and 20.0 K (3')]. Changes in the adsorptive properties upon postsynthetic exchange suggest that the nature, electrostatic properties, mobility, and location of the cations within the framework are crucial for the enhanced structural stability. Overall, these results further confirm the potential of postsynthetic methods (including cation exchange) to obtain PCPs with novel or enhanced physical properties while maintaining unaltered their open-framework structures. PMID:26492551

  8. Preparation and characterization of high capacity, strong cation-exchange fiber based adsorbents.

    Science.gov (United States)

    Schwellenbach, Jan; Taft, Florian; Villain, Louis; Strube, Jochen

    2016-05-20

    Motivated by the demand for more economical capture and polishing steps in downstream processing of protein therapeutics, a novel strong cation-exchange chromatography stationary phase based on polyethylene terephthalate (PET) high surface area short-cut fibers is presented. The fiber surface is modified by grafting glycidyl methacrylate (GMA) via surface-initiated atom transfer radical polymerization (SI-ATRP) and a subsequent derivatization leading to sulfonic acid groups. The obtained cation-exchange fibers have been characterized and compared to commercially available resin and membrane based adsorbers. High volumetric static binding capacities for lysozyme (90mg/mL) and polyclonal human IgG (hIgG, 92mg/mL) were found, suggesting an efficient multi-layer binding within the grafted hydrogel layer. A packed bed of randomly orientated fibers has been tested for packing efficiency, permeability and chromatographic performance. High dynamic binding capacities for lysozyme (50mg/mL) and hIgG (54mg/mL) were found nearly independent of the bed-residence time, revealing a fast mass-transport mechanism. Height equivalent to a theoretical plate (HETP) values in the order of 0.1 cm and a peak asymmetry factor (AF) of 1.8 have been determined by tracer experiments. Additionally inverse size-exclusion chromatography (iSEC) revealed a bimodal structure within the fiber bed, consisting of larger transport channels, formed by the voidage between the fibers, and a hydrogel layer with porous properties. PMID:27106396

  9. Strongly reduced band gap in NiMn2O4 due to cation exchange

    International Nuclear Information System (INIS)

    NiMn2O4 is extensively used as a basis material for temperature sensors due to its negative temperature coefficient of resistance (NTCR), which is commonly attributed to the hopping mechanism involving coexisting octahedral-site Mn4+ and Mn3+. Using density-functional theory + Hubbard U calculations, we identify a ferrimagnetic inverse spinel phase as the collinear ground state of NiMn2O4. By a 12.5% cation exchange, a mixed phase with slightly higher energy can be constructed, accompanied by the formation of an impurity-like band in the original 1 eV band gap. This impurity-like band reduces the gap to 0.35 eV, suggesting a possible source of NTCR. - Highlights: • Density functional based calculations were used to study collinear phase of NiMn2O4. • The ground-state structure is a ferrimagnetic inverse spinel phase. • The tetrahedral and octahedral Mn cations have ferromagnetic interactions. • A 12.5% cation exchange introduces an impurity-like band in the original 1 eV gap. • The 0.35 eV gap suggests a source of negative temperature coefficient of resistance

  10. Solubility and cation exchange in phosphate rock and saturated clinoptilolite mixtures

    Science.gov (United States)

    Allen, E. R.; Hossner, L. R.; Ming, D. W.; Henninger, D. L.

    1993-01-01

    Mixtures of zeolite and phosphate rock (PR) have the potential to provide slow-release fertilization of plants in synthetic soils by dissolution and ion-exchange reactions. This study was conducted to examine solubility and cation-exchange relationships in mixtures of PR and NH4- and K-saturated clinoptilolite (Cp). Batch-equilibration experiments were designed to investigate the effect of PR source, the proportion of exchangeable K and NH4, and the Cp to PR ratio on solution N, P, K, and Ca concentrations. The dissolution and cation-exchange reactions that occurred after mixing NH4- and K-saturated Cp with PR increased the solubility of the PR and simultaneously released NH4 and K into solution. The more reactive North Carolina (NC) PR rendered higher solution concentrations of NH4 and K when mixed with Cp than did Tennessee (TN) PR. Solution P concentrations for the Cp-NC PR mixture and the Cp-TN PR mixture were similar. Solution concentrations of N, P, K, and Ca and the ratios of these nutrients in solution varied predictably with the type of PR, the Cp/PR ratio, and the proportions of exchangeable K and NH4 on the Cp. Our research indicated that slow-release fertilization using Cp/PR media may provide adequate levels of N, P, and K to support plant growth. Solution Ca concentrations were lower than optimum for plant growth.

  11. Some investigations on the radiation stability of a strongly acidic cation exchange resin

    Science.gov (United States)

    Dessouki, A. M.; Zahran, A. H.; Rabie, A. M.; Amer, S. I.

    The radiation-chemical stability of Merck Cation Exchanger I, a strongly acidic sulphonated cation exchanger of the polymerization type based on styrene-divinylbenze (DVB) copolymers was investigated. The radiation stability of the resin was assessed from the change in exchange capacity, loss in weight, change in swelling behaviour and formation of new exchange groups. The loss in capacity was 44 and 32% for resin specimens in the H +-form irradiated to 1000 Mrad in air and in vacuum, respectively. The Na +-form of the exchanger showed high resistance to radiation and the loss in capacity did not exceed 7% at a dose of 1000 Mrad. The loss in capacity was accompanied by a loss in weight and a decrease in the degree of swelling of the irradiated resin. The formation of new functional groups of the carboxylic and phenolic types was confirmed. The amount of these group increases with the increase in the integral dose. The amount of sulphuric acid formed as a result of irradiating the resin in the dry and moist states was determined. An increase in the moisture content of the resin resulted in a marked decrease in its radiation stability.

  12. Purification of urokinase by combined cation exchanger and affinity chromatographic cartridges.

    Science.gov (United States)

    Hou, K C; Zaniewski, R

    1990-02-23

    Crude urokinase from human urine processed through foam flotation and ammonium sulfate precipitation containing 720 National Health Institute Committee on Thrombolytic Agents U/mg activity was purified by an SP cation exchanger followed by a zinc-chelated affinity chromatographic cartridge. The cartridges were of a radial-flow type formed by using acrylic and cellulose composite matrices. The high rigidity of the matrix structure permits fast flow of protein solutions (liters per minute) and thus allows processing of a large volume of crude urokinase under low operating pressures. A greater than six-fold increase in specific enzyme activity of urokinase was achieved by adsorbing and eluting 1 l of a 3 mg/ml crude urokinase solution on an SP cartridge. The eluent was further purified by passing through a zinc-chelated affinity cartridge to achieve greater than a eighteen-fold increase in urokinase specific activity. This report demonstrates the combined use of a cation exchanger with zinc-chelated chromatographic cartridges in purifying urokinase on a relatively large scale. The relationship between the amount of zinc chelated in the matrix to its effect on urokinase purification is also discussed. PMID:2329161

  13. Preliminary studies of the total cation exchange capacity of sediments from two North Atlantic study sites

    International Nuclear Information System (INIS)

    Initially four different methods of measuring total cation exchange capacity were compared. There were two chemical methods (ammonium saturation with displacement into seawater, and barium saturation followed by replacement with magnesium) and two radiochemical methods (sodium-22 and caesium-134 saturation). The barium-magnesium and sodium-22 methods were then applied to sediment samples from Core D10164Pound1K from the Nares Fracture Valley, and Core D10554Pound11K from the eastern flank of the Great Meteor Rise. The material at site 10164 is a pelagic clay whereas at site 10554 it is carbonate ooze. The total cation exchange capacities (T.C.E.C.) of samples from the two sites are similar when measured by the sodium-22 method, the mean for Core 10164 was 21.7 meq/100g and 24.4 meq/100g for Core 10554. However for Core 10554 the barium-magnesium method gives a mean of 42.8 meq/100g. The difference in T.C.E.C. measured by the two methods appears to be due to the high calcite content of core 10554 sediment. Measured exchange capacities are lower than in coastal sediments. In deep sea sediments organic matter either makes a very small contribution to the T.C.E.C. (core 10164) or actually blocks exchange sites (Core 10554). Amorphous oxides of iron and manganese contribute between 20 and 50% of the T.C.E.C. (author)

  14. Light-induced cation exchange for copper sulfide based CO2 reduction.

    Science.gov (United States)

    Manzi, Aurora; Simon, Thomas; Sonnleitner, Clemens; Döblinger, Markus; Wyrwich, Regina; Stern, Omar; Stolarczyk, Jacek K; Feldmann, Jochen

    2015-11-11

    Copper(I)-based catalysts, such as Cu2S, are considered to be very promising materials for photocatalytic CO2 reduction. A common synthesis route for Cu2S via cation exchange from CdS nanocrystals requires Cu(I) precursors, organic solvents, and neutral atmosphere, but these conditions are not compatible with in situ applications in photocatalysis. Here we propose a novel cation exchange reaction that takes advantage of the reducing potential of photoexcited electrons in the conduction band of CdS and proceeds with Cu(II) precursors in an aqueous environment and under aerobic conditions. We show that the synthesized Cu2S photocatalyst can be efficiently used for the reduction of CO2 to carbon monoxide and methane, achieving formation rates of 3.02 and 0.13 μmol h(-1) g(-1), respectively, and suppressing competing water reduction. The process opens new pathways for the preparation of new efficient photocatalysts from readily available nanostructured templates. PMID:26479775

  15. Obtention of the cation exchange capacity of a natural kaolinite with radioactive tracers

    International Nuclear Information System (INIS)

    One of the more used techniques for the elimination of the heavy metals present in water systems is to use adsorbent mineral phases like zeolites and clays, among others. The clays are able to exchange easily the fixed ions in the external surface of its crystals or well the ions present in the interlaminar spaces of the structures, for other existent ones in the encircling aqueous solutions for that the Cation exchange capacity (CIC) is defined as the sum of all the cations exchange that a mineral can possess independent to the physicochemical conditions. The CIC is equal to the measure of the total of negative charges of the mineral by mass of the solid (meq/g). In this investigation work, the value of the CIC equal to 2.5 meq/100 g is obtained, of a natural kaolinite from the State of Hidalgo studying the retention of the sodium in the kaolinite with the aid of the radioactive isotope 24 Na and of the selective electrodes technique, making vary the pH value. So is experimentally demonstrated that the CIC is an intrinsic property of the mineral independent of the pH value of the solution and of the charges origin. (Author)

  16. Cu2Se and Cu Nanocrystals as Local Sources of Copper in Thermally Activated In Situ Cation Exchange

    KAUST Repository

    Casu, Alberto

    2016-01-27

    Among the different synthesis approaches to colloidal nanocrystals a recently developed toolkit is represented by cation exchange reactions, where the use of template nanocrystals gives access to materials that would be hardly attainable via direct synthesis. Besides, post-synthetic treatments, such as thermally activated solid state reactions, represent a further flourishing route to promote finely controlled cation exchange. Here, we report that, upon in situ heating in a transmission electron microscope, Cu2Se nanocrystals deposited on an amorphous solid substrate undergo partial loss of Cu atoms, which are then engaged in local cation exchange reactions with Cu “acceptors” phases represented by rod- and wire- shaped CdSe nanocrystals. This thermal treatment slowly transforms the initial CdSe nanocrystals into Cu2-xSe nanocrystals, through the complete sublimation of Cd and the partial sublimation of Se atoms. Both Cu “donor” and “acceptor” particles were not always in direct contact with each other, hence the gradual transfer of Cu species from Cu2Se or metallic Cu to CdSe nanocrystals was mediated by the substrate and depended on the distance between the donor and acceptor nanostructures. Differently from what happens in the comparably faster cation exchange reactions performed in liquid solution, this study shows that slow cation exchange reactions can be performed at the solid state, and helps to shed light on the intermediate steps involved in such reactions.

  17. Salbutamol versus cation-exchange resin (kayexalate) for the treatment of nonoliguric hyperkalemia in preterm infants.

    Science.gov (United States)

    Yaseen, Hakam; Khalaf, Mona; Dana, Ahmed; Yaseen, Noha; Darwich, Maha

    2008-03-01

    Our objective was to compare the efficacy and safety of rectal cation-exchange resin (Kayexalate) versus salbutamol infusion for the treatment of nonoliguric hyperkalemia (NOHK) in preterm infants. Data of all neonates born with NOHK during the study period of 6 years and 8 months were recorded. Diagnostic criteria of NOHK included serum potassium (SK) concentration > or = 7 mmol/L during the first 72 hours of life with urine output > or = 1 mL/kg/hour. This before-after study was divided according to the date of admission; the first 15 patients were treated with Kayexalate enema 1 g/kg every 4 hours, and the remaining 30 patients were treated with intravenous salbutamol infusion as 4 mug/kg every 4 hours. Treatment discontinued when SK became < 6 mmol/L. SK was measured every 4 hours. Daily urine was collected. Fluid intake and output, serum electrolytes, urea, creatinine, and glucose concentrations were obtained in all infants every 12 hours. All infants were observed with a cardiorespiratory monitor and oxygen saturation and blood pressure measurements. Perinatal characteristics in both groups were comparable. Mean gestational age was 26 and 28 weeks for salbutamol and Kayexalate, respectively. The peak of SK ranged between 7 and 9.3 mmol/L in the Kayexalate group and between 7 and 8.7 mmol/L in the salbutamol group ( P = 0.64). At 12 hours of treatment, SK became normal in only 4 patients (26%) in the Kayexalate group compared with 18 patients (60%) in the salbutamol group ( P = 0.003). The number of doses of Kayexalate administration was significantly higher than the doses of salbutamol ( P = 0.003). No significant side effects were detected in the salbutamol-treated infants. In contrast, there were two cases of severe ventricular tachycardia and one case of intestinal obstruction in the cation-exchange resin group. We concluded that salbutamol infusion is more effective with faster action and safer than cation-exchange resin (Kayexalate) for the treatment of

  18. Distillation Brine Purification for Resource Recovery Applications

    Science.gov (United States)

    Wheeler, Raymond M.

    2014-01-01

    Wastewater processing systems for space generate residual brine that contains water and salts that could be recovered to life support consumables. The project assessed the use of ion-exchange resins to selectively remove salts from wastewater treatment brines. The resins were then regenerated for additional use. The intention would be to generate a Na/K and CI rich or purified brine that would then be processed into high value chemicals, such as acids, bases, and/or bleach.

  19. The Cation Exchange Capacity of Fibrous Feedstuff and Its Nutritive Characteristics

    Institute of Scientific and Technical Information of China (English)

    XING Ting-xian

    2003-01-01

    Current researches on the nutritive characteristics of fibrous feedstuff through determining thefeedstuff cation exchange capacity (CEC) to evaluate its nutritive value at home and abroad were comprehen-sively discribed, and the methods of determining CEC value and the correlation between CEC value and chemi-cal compositions, pH value, and the effect of CEC value on the digestion kinetics in ruminants were also em-phatically introduced. The results of research showed that the CEC values of different feedstuff are different,closely correlated with nitrogen and acid detergent fibre (ADF) and lignin (LIG) content of the feedstuff. Atthe same time, there are markedly effect of CEC value in diet on the nutrients flow of digesta in the digestivetract of ruminants, the degradation rate and digestibility of nutrients in the rumen.

  20. Effect of α-irradiation on the properties of the phosphate cation exchange resin KFP

    International Nuclear Information System (INIS)

    The effect of α-irradiation in a solution of 2 M nitric acid on the properties of the cation-exchange resins KFP-8 and KFP-16 in the range of doses of irradiation up to 5.5 x 188 rad was investigated. It was shown that irradiation leads to a loss of porosity, a decrease in the mechanical strength of the grains, and dissolution of the resin in nitric acid. The exchange capacity of the resin with respect to phosphate groups is decreased: however, new functional groups with low basicity appear, which leads to an increase in the total exchange capacity when the resin is irradiated. The distribution coefficients of fragment elements between the resin and the nitric acid solutions are changed

  1. Complexation of americium(III) with humic acid by cation exchange and solvent extraction

    International Nuclear Information System (INIS)

    Complexation of Am(III) with humic acid was studied at various pHs in 0.1M NaClO4. The stability constants of the Am(III)-humate complexes were determined by a cation-exchange method. The values of logβ1 and logβ2 increased slightly with increases of pH from 4 to 6 and were found to be 6.9 and 11.6, respectively, at a pH of 5. Markedly larger values than these were obtained by a solvent extraction method. This discrepancy was also revealed by summarizing data from several literature sources. It is very likely that this can be ascribed to decreases in either humic acid and/or the extractant from the extraction system due to humate interactions at the aqueous-organic interface. (author)

  2. Potential sources of errors in cation-exchange chromatographic measurement of plasma taurine.

    Science.gov (United States)

    Connolly, B M; Goodman, H O

    1980-03-01

    We examined the potential sources of error in automated cation-exchange chromatographic quantitation of plasma taurine, both in sample preparation and in the analysis. Principal sources of error include: use of serum instead of plasma, which produces gross overestimates; use of tripotassium ethylenediaminetetraacetate (EDTA) as anticoagulant in systems involving ninhydrin detection (a ninhydrin-positive contaminant of EDTA emerges coincident with taurine); contamination with platelets; and placing volumes exceeding 20 microL on the cartridge used in the Technicon TSM Amino Acid Analyzer. We arrived at a simple technique in which we use EDTA as anticoagulant, micropore filtration to produce platelet-free plasma, and o-phthalaldehyde as the detection reagent for the sensitivity required to measure accurately the low concentration of taurine in plasma. PMID:6767571

  3. Synthetic crystalline calcium silicate hydrate (I): cation exchange and caesium selectivity

    International Nuclear Information System (INIS)

    Solid crystalline calcium silicate hydrate (I) synthesized from equimolar amounts of Ca and Si under hydrothermal conditions at 120 oC shows cation exchange properties towards divalent metal cations such as Ni, Cu, Cd, or Hg. It also exhibits caesium selectivity in the presence of Na+. The exchange capacity and selectivity of the solid can be increased by 10 and 28 %, respectively, upon substitution of 0.01 mol of the Ca2+ in its structure by Na+. The ability of metal cation uptake by the solid was found to obey the order Ni2+ > Hg2+ > Cu2+ > Cd2+. The different affinities of calcium silicate hydrate (I) towards these ions can be used for their separation from solutions and also in nuclear waste treatment. The mechanism of the exchange reaction is discussed. (author)

  4. Electrochemical catalytic treatment of wastewater by metal ion supported on cation exchange resin

    International Nuclear Information System (INIS)

    The electrochemical oxidation of phenol in synthetic wastewater and paper mill wastewater catalyzed by metal ion supported on cation exchange resin in suspended bed electrolytic reactor with graphite electrode has been investigated. The catalyst was characterized by SEM and XPS spectra and the effects of pH, the different metal ion and NaCl on the efficiency of the electrochemical oxidation phenol process were also studied. It was found that the catalyst containing Fe3+ had the highest electrochemical catalytic activity for the electrochemical oxidation of phenol. When the initial concentration of phenol was 200 ppm, up to 90% chemical oxygen demand (COD) removal was obtained in 10 min. When the catalyst containing Fe3+ was used to the paper mill wastewater, it still showed high efficiency. The COD removal could get to 75% in 60 min

  5. The treatment of liquid radioactive waste containing Americium by using a cation exchange method

    International Nuclear Information System (INIS)

    A research in the treatment of a liquid radioactive waste containing americium has been done. The liquid radioactive waste used in this research was standard solution of U dan Ce with the initial activity of 100 ppm. The experimental investigation is aimed at a study of the effects of the waste pH, the column dimension of IR-120 cation exchanger which is expressed as L/D, the flow rate of a liquid waste and the influence of thiocyanate as a complex agent against the efficiency of a decontamination for uranium and cerium element. The experiment was done by passing downward the feed of uranium and cerium solution into an IR-120 type of cation exchanger with the L/D of 11.37. From the experimental parameters done in this research where the influence of waste pH was varied from 3 - 8, the geometric column (L/D) 11.37, the liquid flow rate was from 2.5 - 10 ml/m and the thiocyanate concentration was between 100 ppm-500 ppm can be concluded that the optimum operational condition for the ion exchange achieved were the waste pH for uranium = 4 and the waste pH for cerium = 6, the flow rate = 2.5 ml/men. From the given maximum value of DF for uranium = 24 (DE = 95.83%) and of DF for cerium = 40 (DE = 97.5%), it can also be concluded that this investigation is to be continued in order that the greater value of DF/DE can be achieved

  6. CATION-EXCHANGE MEMBRANES WITH POLYANILINE SURFACE LAYER FOR WATER TREATMENT

    Directory of Open Access Journals (Sweden)

    Dinar Dilshatovich Fazullin

    2014-01-01

    Full Text Available Ion-exchange membranes are widely used in modern technologies, particularly in the field of water treatment and make it possible to considerably reduce expenses for wastewater treatment and ensure high degree of purification. Currently, perfluorinated sulfated proton-conducting membranes are often used, such as NAFION and its Russian analogue, MF-4SK based on co-polymerization product of a perfluorinated vinyl ether with tetrafluoroethylene. However, with development of the industry, materials with improved properties and lower cost are required. The aim is to obtain ion-exchange membranes for water treatment from metal ions and to study physico-chemical properties of obtained membranes. In this study, cation exchange composite membranes with modified polyaniline surface layer on nylon and PTFE substrate have been obtained. Changes in the structure of membranes were recorded using a microscope. Throughput capacity of the membranes was determined by passing a certain volume of distilled water through the membrane. The experiment intended to determine electivity of membranes was performed by passing a certain volume of metal salt solutions of a known concentration, after which the filtrate was collected. Concentrations of the studied metal ions in the original solution and in the filtrate were determined by the method of atomic adsorptive spectrometry with electro thermal atomization "Quantum Z.ETA". Prepared highly selective ion exchange membranes. Properties of modified membranes, such as selective permeability and ion-exchange capacity have been determined. The membranes feature high selectivity for heavy metal ions. Moisture-retaining power and swelling ability of the membranes have been studied. Selectivity of the membrane to heavy metal ions is between 70 and 99%. Ion-exchange capacity of the obtained nylon polyaniline membrane is not inferior to some commercially available cation-exchange membranes. Use of the modified membranes in the

  7. Quantification of unsaturated-zone alteration and cation exchange in zeolitized tuffs at Yucca Mountain, Nevada, USA

    Science.gov (United States)

    Vaniman, David T.; Chipera, Steve J.; Bish, David L.; Carey, J. William; Levy, Schön S.

    2001-10-01

    Zeolitized horizons in the unsaturated zone (UZ) at Yucca Mountain, Nevada, USA, are an important component in concepts for a high-level nuclear waste repository at this site. The use of combined quantitative X-ray diffraction and geochemical analysis allows measurement of the chemical changes that accompanied open-system zeolitization at Yucca Mountain. This approach also provides measures of the extent of chemical migration that has occurred in these horizons as a result of subsequent cation exchange. Mass-balance analysis of zeolitized horizons with extensive cation exchange (drill hole UZ-16) and with only minimal cation exchange (drill hole SD-9) shows that Al is essentially immobile. Although zeolitization occurred in an open system, the mass transfer of constituents other than water is relatively small in initial zeolitization, in contrast to the larger scales of cation exchange that can occur after zeolites have formed. Cation exchange in the clinoptilolite ± mordenite zeolitized horizons is seen in downward-diminishing concentration gradients of Ca, Mg, and Sr exchanged for Na and (to lesser extent) K. Comparison with data from drill hole SD-7, which has multiple zeolitized horizons above the water table, shows that the upper horizons accumulate Ca, Mg, and Sr to such an extent that transport of these elements to the deepest UZ zeolitized horizon can be blocked. Quantitative analysis of zeolite formation yields insight into processes that are implied from laboratory studies and modeling efforts but are otherwise unverified at the site. Such analysis also yields information not provided by or contradicted by some models of flow and transport. The results include the following: (1) evidence of effective downward flow through zeolitic horizons despite the low permeability of these horizons, (2) evidence that alkaline-earth elements accumulated by zeolites are mostly derived from eolian materials in surface soils, (3) validation of the very effective

  8. Assessing the role of cation exchange in controlling groundwater chemistry during fluid mixing in fractured granite at Aespoe, Sweden

    International Nuclear Information System (INIS)

    Geochemical modeling was used to simulate the mixing of dilute shallow groundwater with deeper more saline groundwater in the fractured granite of the Redox Zone at the Aespoe underground Hard Rock Laboratory (HRL). Fluid mixing simulations were designed to assess the role that cation exchange plays in controlling the composition of fluids entering the HRL via fracture flow. Mixing simulations included provision for the effects of mineral precipitation and cation exchange on fluid composition. Because the predominant clay mineral observed in fractures in the Redox Zone has been identified as illite or mixed layer illite smectite, an exchanger with the properties of illite was used to simulate cation exchange. Cation exchange on illite was modeled using three exchange sites, a planar or basal plane site with properties similar to smectite, and two edge sites that have very high affinities for K, Rb, and Cs. Each site was assumed to obey an ideal Vanselow exchange model, and exchange energies for each site were taken from the literature. The predicted behaviors of Na, Ca, and Mg during mixing were similar to those reported in a previous study in which smectite was used as the model for the exchanger. The trace elements Cs and Rb were predicted to be strongly associated with the illite exchanger, and the predicted concentrations of Cs in fracture fill were in reasonable agreement with reported chemical analyses of exchangeable Cs in fracture fill. The results of the geochemical modeling suggest that Na, Ca, and Sr concentrations in the fluid phase may be controlled by cation exchange reactions that occur during mixing, but that Mg appears to behave conservatively. There is currently not enough data to make conclusions regarding the behavior of Cs and Rb

  9. Bandgap tunable colloidal Cu-based ternary and quaternary chalcogenide nanosheets via partial cation exchange

    Science.gov (United States)

    Ramasamy, Parthiban; Kim, Miri; Ra, Hyun-Soo; Kim, Jinkwon; Lee, Jong-Soo

    2016-04-01

    Copper based ternary and quaternary semiconductor nanostructures are of great interest for the fabrication of low cost photovoltaics. Although well-developed syntheses are available for zero dimensional (0D) nanoparticles, colloidal synthesis of two dimensional (2D) nanosheets remains a big challenge. Here we report, for the first time, a simple and reproducible cation exchange approach for 2D colloidal Cu2GeSe3, Cu2ZnGeSe4 and their alloyed Cu2GeSxSe3-x, Cu2ZnGeSxSe4-x nanosheets using pre-synthesized Cu2xSe nanosheets as a template. A mechanism for the formation of Cu2-xSe nanosheets has been studied in detail. In situ oxidation of Cu+ ions to form a CuSe secondary phase facilitates the formation of Cu2-xSe NSs. The obtained ternary and quaternary nanosheets have average lateral size in micrometers and thickness less than 5 nm. This method is general and can be extended to produce other important ternary semiconductor nanosheets such as CuIn1-xGaxSe2. The optical band gap of these nanosheets is tuned from 1 to 1.48 eV, depending on their composition.Copper based ternary and quaternary semiconductor nanostructures are of great interest for the fabrication of low cost photovoltaics. Although well-developed syntheses are available for zero dimensional (0D) nanoparticles, colloidal synthesis of two dimensional (2D) nanosheets remains a big challenge. Here we report, for the first time, a simple and reproducible cation exchange approach for 2D colloidal Cu2GeSe3, Cu2ZnGeSe4 and their alloyed Cu2GeSxSe3-x, Cu2ZnGeSxSe4-x nanosheets using pre-synthesized Cu2xSe nanosheets as a template. A mechanism for the formation of Cu2-xSe nanosheets has been studied in detail. In situ oxidation of Cu+ ions to form a CuSe secondary phase facilitates the formation of Cu2-xSe NSs. The obtained ternary and quaternary nanosheets have average lateral size in micrometers and thickness less than 5 nm. This method is general and can be extended to produce other important ternary

  10. Synthesis of Grafted Hydrogels as Mono-Divalent Cation Exchange and Drug Delivery

    International Nuclear Information System (INIS)

    ph-sensitive grafted poly vinyl alcohol-poly acrylic acid (PVA-PAA) hydrogels has been prepared by direct radiation grafting of acrylic acid (AA) onto PVA hydrogels. The grafting percent increase as the monomer concentration and irradiation dose increase. The maximum grafting yield was obtained at monomer concentration 50 % and irradiation dose 50 kGy. The swelling, thermogravimetric analysis, activation energy and scanning electron microscope of the grafted copolymer hydrogels were studied. The swelling of co-polymeric hydrogel was studied at different ph, and the gel demonstrate high swelling at ph 6.8. The de swelling of the swollen hydrogel in Ni2+ and Cu2+ cations solution was explained on the basis of mono-divalent cation exchange. The hydrogel was loaded by antihistaminic chlorphenamine maleate hydrochloride (CPM) as drug model. The release of (CPM) was faster in stimulated gastric fluid (SGF) of ph 1.1 than in stimulated intestinal fluid (SIF) of ph 6.8

  11. Effects of biofouling on ion transport through cation exchange membranes and microbial fuel cell performance.

    Science.gov (United States)

    Choi, Mi-Jin; Chae, Kyu-Jung; Ajayi, Folusho F; Kim, Kyoung-Yeol; Yu, Hye-Weon; Kim, Chang-Won; Kim, In S

    2011-01-01

    This study examines the effects of biofouling on the electrochemical properties of cation exchange membranes (CEMs), such as membrane electrical resistance (MER), specific proton conductivity (SC), and ion transport number (t(+)), in addition to on microbial fuel cell (MFC) performance. CEM biofouling using a 15.5 ± 4.6 μm biofilm was found to slightly increase the MER from 15.65 Ω cm(2) (fresh Nafion) to 19.1 Ω cm(2), whereas an increase of almost two times was achieved when the electrolyte was changed from deionized water to an anolyte containing a high cation concentration supporting bacterial growth. The simple physical cleaning of CEMs had little effect on the Coulombic efficiency (CE), whereas replacing a biofouled CEM with new one resulted in considerable increase of up to 59.3%, compared to 45.1% for a biofouled membrane. These results clearly suggest the internal resistance increase of MFC was mainly caused by the sulfonate functional groups of CEM being occupied with cations contained in the anolyte, rather than biofouling itself. PMID:20659795

  12. Effect of ionophores on the rate of intramolecular cation exchange in durosemiquinone ion pairs

    Science.gov (United States)

    Eastman, M. P.; Bruno, G. V.; Mcguyer, C. A.; Gutierrez, A. R.; Shannon, J. M.

    1979-01-01

    The effects of the ionophores 15-crown-5 (15C5), 18-crown-6 (18C6), dibenzo-18-crown-6 (DBC) and cryptand 222 (C222) on intramolecular cation exchange in ion pairs of the sodium salt of the durosemiquinone anion in benzene solution are investigated. Electron paramagnetic resonance spectra of the 18C6 and 15C5 complexes with durosemiquinone reduced by contact with a sodium mirror show an alternating line width which indicates that the sodium ion is being exchanged between equivalent sites near the oxygens of the semiquinone with activation energies of 8.7 and 6.0 kcal/mole and Arrhenius preexponential factors of 9 x 10 to the 12th/sec and 10 to the 12th/sec, respectively. Spectra obtained for the DBC complexes show no evidence of exchange, while those of C222 indicate rapid exchange. It is also noted that the hyperfine splitting constants measured do not change over the 50-K temperature interval studied.

  13. Ultrathin Sicopion Composite Cation-Exchange Membranes: Characteristics and Electrodialytic Performance following a Conditioning Procedure

    Directory of Open Access Journals (Sweden)

    Erik Ayala-Bribiesca

    2012-01-01

    Full Text Available The aim of this work was to investigate the properties of Sicopion membranes: an ultrathin (≈20 μm composite cation-exchange membrane (CEM made from sulphonated poly(ether-ether-ketone (SPEEK containing different levels of sulphonic-functionalized silica particles (SFSPs. Sicopion membranes were conditioned according to the French Normalization Association procedure, consisting in a series of acid and alkaline washes, and their electrodialytic characteristics were compared to an existent commercial food-grade membrane (CMX-SB. Electrical conductivity of Sicopion membranes was higher than that of CMX-SB membranes (9.92 versus 6.98 mS/cm, as well as their water content (34.0 versus 27.6%. As the SFSP level was reduced, the ion-exchange capacity (IEC of Sicopion membranes increased. Concerning their electrodialytic performances, Sicopion membranes presented a lower demineralization rate than CMX-SB membranes (35.9 versus 45.5%, due to an OH− leakage through the pores created by dislodging the SFSP particles during the conditioning procedure.

  14. Use of Cation Exchange Membrane in Soil Potassium Release and Wheat Response to Potassium

    Institute of Scientific and Technical Information of China (English)

    LIGUI-BAO; J.J.SCHOENAU; 等

    1995-01-01

    A pot experiment was conducted in the growth chamber on Saskatchewan soils with different texture to determine the K release status and wheat K demand.The relationship between K uptake and soil available K extracted by cation exchange membrane(CEM-K) and the effcet of K fertilizer on wheat growth and soil available K was also evaluated.Treatments of 0,60 and 120mg K/kg were applied to sandy,low and high K loamy and clay soils,The highest yields were acieved with the application of 120mg K/kg in sandy soil and 60 mg K/kg in other soils.On the whole,the clay soil contributed K more than other soils from slowly available fraction.Regression revealed a linear relationship between the soil available K extracted by NH4OAc(Ka) and CEM-K in suspensions(r=0.93).Results also showed that CEM-K in burial and in suspensions were different not only in the amount but also in correlation with Ka or K uptake.

  15. Preparation of Medium Cation Exchange Stationary Phase of Polymeric Matrix and Their Chromatographic Properties

    Institute of Scientific and Technical Information of China (English)

    CHEN,Gang; GONG,Bo-Lin; BAI,Quan; GENG,Xin-Du

    2007-01-01

    Based on the monodisperse poly(glycidyl methacrylate-co-ethylenedimethacrylate) beads (PGMA/EDMA) with macropore as a medium, a new hydrophilic medium cation exchange (MCX) stationary phase for HPLC was synthesized by a new chemically modified method. The stationary phase was evaluated with the property of ion exchange, separability, reproducibility, hydrophilicity, effect of salt concentration, salt types, column loading and pH on the separation and retention of proteins in detail. It was found that it follows ion exchange chromatographic (IEC)retention mechanism. The measured bioactivity recovery for lysozyme was (96±5)%. The dynamic protein loading capacity of the synthesized MCX packings was 21.8 mg/g. Five proteins were almost completely separated within 6.0 min at a flow rate of 4 mL/min using the synthesized MCX resin. The MCX resin was also used for the rapid separation and purification of lysozyme from egg white with only one step. The purity and specific bioactivity of the purified lysozyme was found more than 95% and 70345 U/mg, respectively.

  16. Effects of Experimental Conditions on Extraction Yield of Extracellular Polymeric Substances by Cation Exchange Resin

    Directory of Open Access Journals (Sweden)

    Jinwoo Cho

    2012-01-01

    Full Text Available Effects of experimental conditions on the yield of extracellular polymeric substances (EPSs extraction by cation exchange resin (CER were investigated using activated sludge flocs. The experimental variables included resin dose, extraction time, sample dilution, and storage time. An empirical model was proposed to describe the kinetics of extraction process. The extraction yield increases with the extraction time and CER dose until it reached the maximum amount of EPS extraction. The maximum yield of EPS was affected as well by the sample dilution, exhibiting a decreasing trend with increasing dilution factor. It was also found that the amount of EPS extracted from a raw sample depends on the storage time. Once EPS was extracted from the sample, however, the EPS keeps its original quantity under storage at 4°C. Based on the model, the maximum amount of EPS extraction and yield rate could be estimated for different conditions. Comparing the model parameters allows one to quantitatively compare the extraction efficiencies under various extracting conditions. Based on the results, we recommend the original sample should be diluted with the volume ratio of above 1 : 2 and a raw sample should be treated quickly to prevent the reduction of sample homogeneity and original integrity.

  17. Cation exchange resin immobilized bimetallic nickel-iron nanoparticles to facilitate their application in pollutants degradation.

    Science.gov (United States)

    Ni, Shou-Qing; Yang, Ning

    2014-04-15

    Nanoscale zerovalent iron (nZVI) usually suffers from reduction of reactivity by aggregation, difficulty of assembling, environmental release and health concerns. Furthermore, data are lacking on the effect of cheap nickel on debromination of decabromodiphenyl ether (DBDE) by immobilized nZVI in aqueous system. In this study, strong acid polystyrene cation-exchange resins with particle diameter from 0.4 to 0.6 mm were utilized as matrices to immobilize bimetallic nickel-iron nanoparticles in order to minimize aggregation and environmental leakage risks of nZVI and to enhance their reactivity. Elemental distribution mapping showed that iron particles distributed uniformly on the surface of the resin and nickel particles were dispersed homogeneously into Fe phase. The reaction rate of resin-bound nZVI is about 55% higher than that of dispersed nZVI. The immobilized bimetallic nanoparticles with 9.69% Ni had the highest debromination percent (96%) and reaction rate (0.493 1/h). The existence of Ni significantly improved the debromination rate, due to the surface coverage of catalytic metal on the reductive metal and the formation of a galvanic cell. The environmental dominant congeners, such as BDE 154, 153, 100, 99 and 47, were produced during the process. Outstanding reactive performance, along with magnetic separation assured that resin-bound bimetallic nickel-iron nanoparticles are promising material that can be utilized to remediate a wide variety of pollutants contaminated sites including polybrominated diphenyl ethers. PMID:24559714

  18. Effects of experimental conditions on extraction yield of extracellular polymeric substances by cation exchange resin.

    Science.gov (United States)

    Cho, Jinwoo; Hermanowicz, Slawomir W; Hur, Jin

    2012-01-01

    Effects of experimental conditions on the yield of extracellular polymeric substances (EPSs) extraction by cation exchange resin (CER) were investigated using activated sludge flocs. The experimental variables included resin dose, extraction time, sample dilution, and storage time. An empirical model was proposed to describe the kinetics of extraction process. The extraction yield increases with the extraction time and CER dose until it reached the maximum amount of EPS extraction. The maximum yield of EPS was affected as well by the sample dilution, exhibiting a decreasing trend with increasing dilution factor. It was also found that the amount of EPS extracted from a raw sample depends on the storage time. Once EPS was extracted from the sample, however, the EPS keeps its original quantity under storage at 4°C. Based on the model, the maximum amount of EPS extraction and yield rate could be estimated for different conditions. Comparing the model parameters allows one to quantitatively compare the extraction efficiencies under various extracting conditions. Based on the results, we recommend the original sample should be diluted with the volume ratio of above 1:2 and a raw sample should be treated quickly to prevent the reduction of sample homogeneity and original integrity. PMID:22919352

  19. Effect of Lanthanum Accumulation on Cation Exchange Capacity and Solution Composition of Red Soil

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Pot and adsorption-exchange experiments were carried out by collecting the soil samples from the surface layer (0~15 cm) of red soil at the Ecological Experiment Station of Red Soil, the Chinese Academy of Sciences, in Jiangxi Province of China. When concentration of the exogenous La3+ exceeded 400 mg kg-1, there was less non-exchangeable La3+ than exchangeable La3+ in the soil. Cation exchange capacity of the soil changed slightly with increasing concentration of the exogenous La3+ in both experiments. However, in the adsorption-exchange experiment, when concentration of the exogenous La3+ was higher than 300 mg kg-1, exchangeable basic cations decreased significantly, while exchangeable hydrogen and exchangeable aluminum increased significantly compared with the control treatments. The amounts of base cations (Ca2+, Mg2+, K+ and Na+) exchanged by La3+ in the supernatant solution increased with the concentration of the exogenous La3+, especially when concentration of the exogenous La3+ was higher than 50 mg kg-1.

  20. DecorporatinC facilities of cation-exchange resins with different characteristics on radioactive strontium

    International Nuclear Information System (INIS)

    Efficiency in promoting radiostrontium elimination from the body was studied comparatively for cation-exchange resins differing in type of exchanging moieties, mesh sizes, or extent of cross-linkage in the polymere molecule. The experiments were performed on rats receiving each an oral dose of 5 μCi or 85Sr in a 10 μCi/ml aqueous solution of strontium bichloride. The resins, suspended in sodium carboxymethyl cellulose solution, were administered either 10 or 30 minutes after radionuclide ingestion. From 2 hours to 72 hours after treatment, the animals were whole-body counted, and shortly thereafter their femur radioactivity was measured. All of the resin types tested were found to decrease strontium body burdens, with Amberlite IR-120 and Amberlite IRC-50 showing the most favourable effect. Tne efficiency of the resins did not appear to depend on the type of ion-exchange site. Similarly, no relation was observed with the amount of cross-linkage. It was the resins with minimum mesh sizes that proved more effective. (A.B.)

  1. Adsorption equilibrium and kinetics of monomer-dimer monoclonal antibody mixtures on a cation exchange resin.

    Science.gov (United States)

    Reck, Jason M; Pabst, Timothy M; Hunter, Alan K; Wang, Xiangyang; Carta, Giorgio

    2015-07-10

    Adsorption equilibrium and kinetics are determined for a monoclonal antibody (mAb) monomer and dimer species, individually and in mixtures, on a macroporous cation exchange resin both under the dilute limit of salt gradient elution chromatography and at high protein loads and low salt based on batch adsorption equilibrium and confocal laser scanning microscopy (CLSM) experiments. In the dilute limit and weak binding conditions, the dimer/monomer selectivity in 10mM phosphate at pH 7 varies between 8.7 and 2.3 decreasing with salt concentration in the range of 170-230mM NaCl. At high protein loads and strong binding conditions (0-60mM NaCl), the selectivity in the same buffer is near unity with no NaCl added, but increases gradually with salt concentration reaching high values between 2 and 15 with 60mM added NaCl. For these conditions, the two-component adsorption kinetics is controlled by pore diffusion and is predicted approximately by a dual shrinking core model using parameters based on single component equilibrium and kinetics measurements. PMID:26028510

  2. Relative activities of siloxane monomers toward the cation exchange resin-catalyst in the equilibration reactions

    Directory of Open Access Journals (Sweden)

    M. N. GOVEDARICA

    2001-07-01

    Full Text Available The relative activities of a number of siloxane monomers, both cyclic and linear, toward the cation exchange resin-equilibration catalyst were determined. The determination was based on the fact that when a particular siloxane compound is added to an arbitrarily chosen equilibrate, it takes part in the equilibration process, provoking certain viscosity changes of the reaction mixture. Taking these viscosity changes as a measure of activities, the following order was obtained: hexamethylcyclotrisiloxane > hexamethyldisiloxane > octamethylcyclotetrasiloxane > one linear all-methyl oligosiloxane of number average molecular weight of approximately 800 > decamethylcyclopentasiloxane. The results obtained by using the described viscosimetrical determination method were controlled by measuring the number average molecular weights of the reaction mixtures at the beginning and at the end of the equilibration process. The deviations of the experimentally measured from the calculated values were less than 20 %, as was found in one equilibration system. In most other systems the deviations were about 10 % which is a very good result which strengthens the validity of the applied determination method.

  3. Short communication: Predicting cation exchange capacity from hygroscopic moisture in agricultural soils of Western Europe

    Directory of Open Access Journals (Sweden)

    José Torrent

    2015-12-01

    Full Text Available Soil cation exchange capacity (CEC depends on the extent and negative charge density of surfaces of soil mineral and organic components. Soil water sorption also depends on the extent of such surfaces, giving thus way to significant relationships between CEC and hygroscopic moisture (HM in many soils. In this work, we explored whether CEC could be accurately predicted from HM in agricultural soils of Mediterranean and humid temperate areas in Western Europe. For this purpose, we examined 243 soils across a wide variation range of their intrinsic properties. Soil CEC was determined using 1 M ammonium acetate at pH 7 and HM at an equilibrium air relative humidity (RH of 43% (HM43. Most of the variation of soil CEC was explained by HM43 through a linear function (CEC = 1.4 + 0.78HM43; R2 = 0.962; standard deviation = 2.30 cmolc/kg. Coefficients of the regression equation were similar for subgroups of soils differing in moisture regime, clay mineralogy, carbonate content and organic carbon content. Therefore, soil hygroscopic moisture measurements at a fixed RH level provided a simple, robust, inexpensive method for predicting soil CEC.

  4. A study on Sn4+ cation exchange natural zeolite treated at different temperatures

    International Nuclear Information System (INIS)

    The samples of Sn4+ zeolite are obtained by cation exchange between natural zeolite and SnCl4, and then treated at different temperatures (70 -1000 deg C). By using Moessbauer spectroscopy, X-ray diffraction and infra-red spectroscopy, the change of position of Sn4+ in the zeolite structure with the temperature is studied. The results show that the Sn4+ is situated in the main duct (channel) of the zeolite structure, but with the increase of the temperature the zeolite is dehydrated gradually, then the Sn4+ begins to move from the center of the duct to the walls of the duct, consequently, owing to the increase of the asymmetry of the electric field where the Sn4+ is situated, the quadruple splitting increase with the increase of the temperature. At the same time the SnO2 component increases with the increase of temperature. When heat-treatment temperature reached 1000 deg C the long range order structure of zeolite may be destroyed completely

  5. chromatographic studies for separation of light lanthanides using Dowex-50X8 cation exchanger

    International Nuclear Information System (INIS)

    chromatographic elution of light lanthanides (La, Ce, Nd and Sm) using the strong cation exchange resin, Dowex-50X8 has been investigated through certain elution parameters. elution profiles of La, Ce, Nd and Sm were studied with three different mobile phases: oxalic acid, citric acid and sodium hexameta phosphate. considering % recovered, sodium hexameta phosphate showed the highest values with all investigated elements but it has some disadvantages like tailing, low separation and resolution values that indicating a poor separation pattern and long elution time. on other side citric acid showed many advantages as an eluent over the other eluents, where it has narrow and symmetrical elution peaks compared to those of the other eluents. increasing citric acid concentration , it was observed that the separation factor decreased although the % recovered increased. from ph 3.5-6.5 the retention volumes of the investigated ions decreased drastically, indicating that the separation factor between each neighboring element also decreased . it was also observed that, the distribution coefficient not affected by changing the flow rate from 1 to 10 ml/min. for easy detection and identification , the ion chromatography technique was used.

  6. Independent control of the shape and composition of ionic nanocrystals through sequential cation exchange reactions

    Energy Technology Data Exchange (ETDEWEB)

    Luther, Joseph Matthew; Zheng, Haimei; Sadtler, Bryce; Alivisatos, A. Paul

    2009-07-06

    Size- and shape-controlled nanocrystal growth is intensely researched for applications including electro-optic, catalytic, and medical devices. Chemical transformations such as cation exchange overcome the limitation of traditional colloidal synthesis, where the nanocrystal shape often reflects the inherent symmetry of the underlying lattice. Here we show that nanocrystals, with established synthetic protocols for high monodispersity, can be templates for independent composition control. Specifically, controlled interconversion between wurtzite CdS, chalcocite Cu2S, and rock salt PbS occurs while preserving the anisotropic dimensions unique to the as-synthesized materials. Sequential exchange reactions between the three sulfide compositions are driven by the disparate solubilites of the metal ion exchange pair in specific coordinating molecules. Starting with CdS, highly anisotropic PbS nanorods are created, which serve as an important material for studying strong 2-dimensional quantum confinement, as well as for optoelectronic applications. Furthermore, interesting nanoheterostructures of CdS|PbS are obtained by precise control over ion insertion and removal.

  7. Synthesis of high capacity cation exchangers from a low-grade Chinese natural zeolite

    International Nuclear Information System (INIS)

    The Chinese natural zeolite, in which clinoptilolite coexists with quartz was treated hydrothermally with NaOH solutions, either with or without fusion with NaOH powder as pretreatment. Zeolite Na-P, Na-Y and analcime were identified as the reacted products, depending on the reaction conditions such as NaOH concentration, reaction time and hydrothermal temperature. The products were identified by X-ray diffraction, and characterized by Fourier transform IR and ICP. With hydrothermal treatment after fusion of natural zeolite with NaOH, high purity of zeolite Na-Y and Na-P can be selectively formed, their cation exchange capacity (CEC) are 275 and 355 meq/100 g respectively, which are greatly higher than that of the natural zeolite (97 meq/100 g). Furthermore, the ammonium removal by the synthetic zeolite Na-P in aqueous solution was also studied. The equilibrium isotherms have been got and the influence of other cations present in water upon the ammonia uptake suggested an order of preference Ca2+ > K+ > Mg2+.

  8. Strong cation exchange resin for improving physicochemical properties and sustaining release of ranitidine hydrochloride

    Directory of Open Access Journals (Sweden)

    Khan S

    2007-01-01

    Full Text Available In the present study strong cation exchange resin (Amberlite IRP69 was used to improve the physicochemical properties of ranitidine hydrochloride such as taste and bulk properties and to sustain dissolution rate. Drug-resin complexes were prepared using batch method. Drug loading was done under different processing conditions such as temperature, pH, drug-resin ratio, and drug concentration to get the optimum condition for resinate preparation. Resinate prepared under optimized condition was tested for taste, bulk properties and release rate. Degree of bitterness of ranitidine was found to reduce to zero after complexation with resin. Improvement in flow properties was also observed. Angle of repose for resinate was found to be 33.21 o as compared to 42.27 o for ranitidine HCl. Effect of dissolution medium and particle size on in vitro release of drug from resinate was also investigated. Resinate with drug to resin ratio of 2:3 and particle size> 90 µm showed about 90% of drug release within 12 h. The orodispersible tablet formulated from the resinate containing 10% croscarmellose sodium disintegrated within 35 sec in oral cavity and showed similar dissolution profile as the resinate. Tablets were found stable after stability studies with no change in dissolution profile.

  9. Influence of the Ion Coordination Number on Cation Exchange Reactions with Copper Telluride Nanocrystals

    CERN Document Server

    Tu, Renyong; Bertoni, Giovanni; Lak, Aidin; Gaspari, Roberto; Rapallo, Arnaldo; Cavalli, Andrea; De Trizio, Luca; Manna, Liberato

    2016-01-01

    Cu2-xTe nanocubes were used as starting seeds to access metal telluride nanocrystals by cation exchanges at room temperature. The coordination number of the entering cations was found to play an important role in dictating the reaction pathways. The exchanges with tetrahedrally coordinated cations (i.e. with coordination number 4), such as Cd2+ or Hg2+, yielded monocrystalline CdTe or HgTe nanocrystals with Cu2-xTe/CdTe or Cu2-xTe/HgTe Janus-like heterostructures as intermediates. The formation of Janus-like architectures was attributed to the high diffusion rate of the relatively small tetrahedrally coordinated cations, which could rapidly diffuse in the Cu2-xTe NCs and nucleate the CdTe (or HgTe) phase in a preferred region of the host structure. Also, with both Cd2+ and Hg2+ ions the exchange led to wurtzite CdTe and HgTe phases rather than the more stable zinc-blende ones, indicating that the anion framework of the starting Cu2- xTe particles could be more easily deformed to match the anion framework of t...

  10. Measurement of the acidities of several cation-exchange resins using hydrogen-isotope exchange reaction

    International Nuclear Information System (INIS)

    The hydrogen-isotope exchange reaction between ethanol (unlabeled) and one of three cation-exchange resins labeled with tritium has been observed at 40-80degC. The acidity (acidity based on kinetic logic) at each temperature has been obtained from a A'-McKay plot based on the respective data obtained. The following results have been obtained on the basis of both the acidities obtained in this work and the acidities (of several materials) obtained previously. (1) The order of the reactivity is (Amberlite IRC-76)>(Dowex A-1)>(PVA2000>(Amberlite IRC-50) at 60degC. (2) The higher the temperature, the larger is the reactivity of each material. (3) The temperature dependence of the reactivity of Dowex A-1 is the largest in the four. (4) The reactivity of the functional group (i.e., COOH group or OH group) bonded to the polymer chain can be clarified using the A'-McKay plot method. (5) It seems that method can be applied to analyze other reactions, e.g., other isotope-exchange reactions, surface reactions, catalytic reactions, etc. (author)

  11. Selective sorption of lead, cadmium and zinc ions by a polymeric cation exchanger containing nano-Zr(HPO3S)2.

    Science.gov (United States)

    Zhang, Qingrui; Pan, Bingcai; Pan, Bingjun; Zhang, Weiming; Jia, Kun; Zhang, Quanxing

    2008-06-01

    A novel polymeric hybrid sorbent, namely ZrPS-001, was fabricated for enhanced sorption of heavy metal ions by impregnating Zr(HPO3S)2 (i.e., ZrPS) nanoparticles within a porous polymeric cation exchanger D-001. The immobilized negatively charged groups bound to the polymeric matrix D-001 would result in preconcentration and permeation enhancement of target metal ions prior to sequestration, and ZrPS nanoparticles are expected to sequester heavy metals selectively through an ion-exchange process. Highly effective sequestration of lead, cadmium, and zinc ions from aqueous solution can be achieved by ZrPS-001 even in the presence of competing calcium ion at concentration several orders of magnitude greater than the target species. The exhausted ZrPS-001 beads are amenable to regeneration with 6 M HCI solution for repeated use without any significant capacity loss. Fixed-bed column treatment of simulated waters containing heavy metals at high or trace levels was also performed. The content of heavy metals in treated effluent approached or met the WHO drinking water standard. PMID:18589978

  12. The role of cation exchange in the sorption of cadmium, copper and lead by soils saturated with magnesium

    International Nuclear Information System (INIS)

    The displacement of Ca2+, Mg2+, K+ and Al3+ from the A and Bw or Bt horizons of two soils developed over serpentinized amphibolites when equilibrated in Cu2+, Cd2+ or Pb2+ solutions was determined, together with the concomitant sorption of the heavy metal. The contributions of Mg2+ to the effective cation exchange capacities of the A and Bt horizons of the Endoleptic Luvisol were 57% and 94%, respectively, and its contributions to those of the A and Bw horizons of the Mollic Cambisol were 70% and 77%, respectively. In all four horizons, cation exchange, chiefly with Mg2+ and Ca2+, was the process chiefly responsible for sorption of Cd2+, Cu2+ and Pb2+. Al3+ and K+ were hardly implicated, especially in the case of Cd2+.

  13. Energy storage in evaporated brine

    Energy Technology Data Exchange (ETDEWEB)

    MacDonald, R. Ian

    2010-09-15

    We propose storage of electrical energy in brine solutions by using the energy to enhance natural evaporation. Using properties of existing industrial evaporation technologies and estimates of power regeneration from brine by pressure retarded osmosis, efficiency near 100% is calculated. Modelling indicates that systems ranging from 50kW to 50MW output may be practical, with storage capacities of hours to days. The method appears to have potential to be economically competitive with other technologies over a wide range of capacity. It may present a large new application area that could aid the development of salinity-based power generation technology.

  14. Uranium adsorption from the sulphuric acid leach liquor containing more chlorides with cation-exchange resin SL-406

    International Nuclear Information System (INIS)

    The feasibility of uranium adsorption was studied from the sulphuric acid leach liquor of a uranium ore containing more chlorides with cation-exchange resin SL-406. The influence of some factors on uranium adsorption was investigated. It was shown that the resin possesses better selectivity, stability and higher capacity. It can be effectively used to recovery uranium from leach liquors of uranium ores containing more chlorides

  15. A comparison between three methods for the determination of cation exchange capacity and exchangeable cations in soils

    OpenAIRE

    Ciesielski, H.; Sterckeman, T.

    1997-01-01

    The object of this study is to compare the results obtained with three standardized methods of determination of cationic exchange capacity (CEC) and exchangeable cations (Ca, Mg, K) in soils. The three methods are based on different exchange reagents: cobalt hexamine (Cohex) trichloride, barium chloride and ammonium acetate. Exchange procedures are different as well; they are, respectively, single extraction, successive extractions and percolation. Values measured with barium and Cohex as ind...

  16. Ergot alkaloids in rye flour determined by solid phase cation-exchange and high pressure liquid chromatography with fluorescence detection

    OpenAIRE

    Storm, Ida Drejer; Have Rasmussen, Peter; Strobel, Bjarne W.; Hansen, Hans Christian Bruun

    2008-01-01

    Abstract Ergot alkaloids (EAs) are mycotoxins which are unavoidable contaminants of cereal products, particularly rye. A method was compiled employing clean-up by cation-exchange solid phase extraction, separation by high-pressure liquid chromatography under alkaline conditions and fluorescence detection. It is capable of separating and quantifying both C8-isomers of ergocornine, a-ergocryptine, ergocristine, ergonovine, and ergotamine. The average recovery was 61?10 % with limits ...

  17. Superparamagnetic cation-exchange adsorbents for bioproduct recovery from crude process liquors by high-gradient magnetic fishing

    DEFF Research Database (Denmark)

    Heebøll-Nielsen, Anders; Justesen, S.F.L; Hobley, Timothy John;

    2004-01-01

    Different routes were screened for the preparation of superparamagnetic cation-exchange adsorbents for the capture of proteins using high-gradient magnetic fishing. Starting from a polyglutaraldehyde-coated base particle, the most successful of these involved attachment of sulphite to oligomers of...... from sweet bovine whey. Subsequently, a high-gradient magnetic fishing process was constructed for the fractionation of whey, in which lactoperoxidase was purified 36-fold and concentrated 4.7-fold...

  18. Optimization of acidified oil esterification catalyzed by sulfonated cation exchange resin using response surface methodology

    International Nuclear Information System (INIS)

    Highlights: • As lipid source, acidified oil are from industrial wastes for renewable energy. • The predicted conversion rate of FFAs was 75.24% under the RSM optimized conditions. • The adsorption system was employed to remove the water produced to shift the equilibrium toward ethyl ester production. • Maximum conversion rate of 98.32% was obtained using adsorption system at optimum process parameters. • Compared with tradition methods, molecular sieve dehydration method improved the conversion rate by 23.08%. - Abstract: The esterification of acidified oil with ethanol catalyzed by sulfonated cation exchange resins (SCER) was optimized using the response surface methodology (RSM). The effects of the molar ratio of ethanol to acidified oil, reaction time and catalyst loading on the conversion rate of free fatty acids (FFAs) were investigated at the temperature of the boiling point of ethanol. Results showed that the highest conversion rate of 75.24% was obtained at the molar ratio of ethanol to acidified oil of 23.2, reaction time of 8.0 h and catalyst loading of 35.0 wt.%. Moreover, the conversion rate of FFAs was increased to 98.32% by using a water adsorption apparatus under the RSM optimized conditions. Scanning electronic microscopic–energy dispersive spectrometric (SEM–EDS), X-ray diffractometric (XRD) and thermogravimetric–derivative thermogravimetric (TG–DTG) analyses confirmed that the morphology of catalysts did not change much and the mechanical and thermal stabilities were still good after the reaction. Furthermore, SCER exhibited a high catalytic activity and stability after being reused for five successive times. The fuel properties of the biodiesel were comparable to that of ASTM, EN and GB biodiesel standard

  19. Separation of proteins by cation-exchange sequential injection chromatography using a polymeric monolithic column.

    Science.gov (United States)

    Masini, Jorge Cesar

    2016-02-01

    Since sequential injection chromatography (SIC) emerged in 2003, it has been used for separation of small molecules in diverse samples, but separations of high molar mass compounds such as proteins have not yet been described. In the present work a poly(glycidyl methacrylate-co-ethylene dimethacrylate) (GMA-co-EDMA) monolithic column was prepared by free radical polymerization inside a 2.1-mm-i.d. activated fused silica-lined stainless steel tubing and modified with iminodiacetic acid (IDA). The column was prepared from a mixture of 24% GMA, 16% EDMA, 20% cyclohexanol, and 40% 1-dodecanol (all% as w/w) containing 1% of azobisisobutyronitrile (AIBN) (in relation to monomers). Polymerization was done at 60 °C for 24 h. The polymer was modified with 1.0 M IDA (in 2 M Na2CO3, pH 10.5) at 80 °C for 16 h. Separation of myoglobin, ribonuclease A, cytochrome C, and lysozyme was achieved at pH 7.0 (20 mM KH2PO4/K2HPO4) using a salt gradient (NaCl). Myoglobin was not retained, and the other proteins were separated by a gradient of NaCl created inside the holding coil (4 m of 0.8-mm-i.d. PTFE tubing) by sequential aspiration of 750 and 700 μL of 0.2 and 0.1 M NaCl, respectively. As the flow was reversed toward the column (5 μL s(-1)) the interdispersion of these solutions created a reproducible gradient which separated the proteins in 10 min, with the following order of retention: ribonuclease A < cytochrome C < lysozyme. The elution order was consistent with a cation-exchange mechanism as the retention increased with the isoelectric points. PMID:26677024

  20. Probing the Complementarity of FAIMS and Strong Cation Exchange Chromatography in Shotgun Proteomics

    Science.gov (United States)

    Creese, Andrew J.; Shimwell, Neil J.; Larkins, Katherine P. B.; Heath, John K.; Cooper, Helen J.

    2013-03-01

    High field asymmetric waveform ion mobility spectrometry (FAIMS), also known as differential ion mobility spectrometry, coupled with liquid chromatography tandem mass spectrometry (LC-MS/MS) offers benefits for the analysis of complex proteomics samples. Advantages include increased dynamic range, increased signal-to-noise, and reduced interference from ions of similar m/ z. FAIMS also separates isomers and positional variants. An alternative, and more established, method of reducing sample complexity is prefractionation by use of strong cation exchange chromatography. Here, we have compared SCX-LC-MS/MS with LC-FAIMS-MS/MS for the identification of peptides and proteins from whole cell lysates from the breast carcinoma SUM52 cell line. Two FAIMS approaches are considered: (1) multiple compensation voltages within a single LC-MS/MS analysis (internal stepping) and (2) repeat LC-MS/MS analyses at different and fixed compensation voltages (external stepping). We also consider the consequence of the fragmentation method (electron transfer dissociation or collision-induced dissociation) on the workflow performance. The external stepping approach resulted in a greater number of protein and peptide identifications than the internal stepping approach for both ETD and CID MS/MS, suggesting that this should be the method of choice for FAIMS proteomics experiments. The overlap in protein identifications from the SCX method and the external FAIMS method was ~25 % for both ETD and CID, and for peptides was less than 20 %. The lack of overlap between FAIMS and SCX highlights the complementarity of the two techniques. Charge state analysis of the peptide assignments showed that the FAIMS approach identified a much greater proportion of triply-charged ions.

  1. Cation exchange resins labeled with holmium-166 for treatment of liver malignancy

    International Nuclear Information System (INIS)

    The increasing interest in new therapeutic radiopharmaceuticals is prompting investigators to utilize isotopes with more focused capabilities for treating various tumors, reducing the negative effects on neighboring healthy cells. Local radionuclide therapy using radioactive microspheres is a promising therapy for non-operable group of patients suffering from liver malignancies. Many publications have shown the success of this technique. The emphasis in the present work is the resin-based microspheres labeled with 166Ho. The production of 166Ho is feasible in the IEA-R1 Reactor at IPEN-CNEN/SP, because it does not need high power and high neutron fluxes. Samples of Ho2O3 were irradiated in selected positions of the nuclear reactor IEA-R1 at IPEN/CNEN-SP. The neutron flux was 1.0 x1013 n.s-1.cm-2 for 1 hour. The dissolution of Ho2O3 was studied with different volumes of 0.1M HCl and also varying the heating temperature. The AG50W-X8 200-400 mesh and CM Sephadex C-25 cation exchange resins were labeled with 166Ho. The retention of 166Ho in the resins was studied and also its stability. The results of the dissolution experiments of Ho2O3 showed that there is a direct relation between the increasing volumes needed to dissolve higher masses, and also the positive effect of raising the temperature. The results show very good retention of 166Ho in both columns, even when high volumes of 0.1M HCl are passed through the column containing the resins and its good stability towards saline solution, PBS solution and glucose.Although the resins employed in this work did not have the right particle size (20-50μm), the chemical behavior showed the very good labeling of the resins with 166Ho, and its stability. (author)

  2. Effect of cation exchange of major cation chemistry in the large scale redox experiment at Aespoe. Revision 1

    International Nuclear Information System (INIS)

    Geochemical modeling was used to test the hypothesis that cation exchange with fracture-lining clays during fluid mixing in the Aespoe Hard Rock Laboratory can significantly affect major element chemistry. Conservative mixing models do not adequately account for changes in Na, Ca and Mg concentrations during mixing. Mixing between relatively dilute shallow waters and more concentrated waters at depth along fracture zones was modeled using the EQ3/6 geochemical modeling package. A cation exchange model was added to the code to describe simultaneously aqueous speciation, mineral precipitation/dissolution, and equilibration between a fluid and a cation exchanger. Fluid chemistries predicted to result from mixing were compared with those monitored from boreholes intersecting the fracture zone. Modeling results suggest that less than 0.1 equivalent of a smectite exchanger per liter of groundwater is necessary to account for discrepancies between predictions from a conservative mixing model and measured Na and Ca concentrations. This quantity of exchanger equates to an effective fracture coating thickness of 20 microm or less given a fracture aperture width of 1,000 microm or less. Trends in cation ratios in the fluid cannot be used to predict trends in cation ratios on the exchanger because of the influence of ionic strength on heterovalent exchange equilibrium. It is expected that Na for Ca exchange will dominate when shallow waters such as HBHO2 are mixed with deeper waters. In contrast, Na for Mg exchange will dominate mixing between deeper waters

  3. Development of low cost ceramic separator using mineral cation exchanger to enhance performance of microbial fuel cells

    International Nuclear Information System (INIS)

    This study deals with the development of ceramic separator (CS) made from red soil blended with cation exchanger, Montmorillonite and Kaolinite, for its application in microbial fuel cells (MFCs). The separators were characterized in terms of conductivity, oxygen, acetate and proton diffusion, and ion transport ability. Performance of MFCs using different CS was evaluated under batch mode of operation. MFC M-20 (CS blended with 20% Montmorillonite) exhibited maximum power density of 7.5 W/m3 which was 48% higher than MFC without exchanger (Control) and 30%, 9%, 27% higher than MFC M-10 (10% Montmorillonite), MFC M-15 (15% Montmorillonite), MFC K-20 (20% Kaolinite), respectively. Coulombic efficiency of MFC M-20 (30%) and MFC K-20 (23%) was higher compared to control (18%). Use of cation exchangers improved properties of ceramic separators compared to control. Higher cation exchange capacity (CEC) of Montmorillonite (150 meq/100 g) resulted in 4 fold decrease in charge transfer resistance (3.4 Ω) and 1.8 fold increase in conductivity (5.56 × 10−4 S/cm) of CS as compared to Kaolinite. This study demonstrates that Montmorillonite incorporated CS proved to be suitable alternative to replace costly polymeric membrane to increase power output of MFC at reduced cost

  4. FACTORS AFFECT THE RELEASE OF PSEUDOEPHDRINE HYDROCHLORIDE FROM THE UNCOATED CATION EXCHANGE RESIN-BASED DRUG DELIVERY SYSTEM IN VITRO

    Institute of Scientific and Technical Information of China (English)

    LI Zhenhua; PI Hongqiong; HE Binglin

    2001-01-01

    In this paper, it was investigated that the effect of parameters such as the ionic strength,pH, counter-ion type of release medium, particle size, and cross linkage of cation exchange resin on the release of model drug pseudoephedrine hydrochloride (PE) from uncoated drug-resin complex.The drug-resin complex was prepared by the reaction of PE with strongly acidic cation exchange resin (001 ×4, 001 ×7, 001 ×14). The result showed that the loading of PE increased with the increase of temperatures. The release of PE from drug-resin complex at 37 ℃ was monitored in vitro.From the experiments, it was found that the release rate of PE depends on the pH, composition of the releasing media, increased at lower pH media or with increase of ionic strength of media. Moreover,the release rate of PE was inversely proportional to the cross-linkage and particle size of the cation exchange resin.

  5. Preparation of poly(glycidylmethacrylate-divinylbenzene) weak acid cation exchange stationary phases with succinic anhydride, phthalic anhydride, and maleic anhydride for ion chromatography.

    Science.gov (United States)

    Liu, Junwei; Wang, Yong; Wu, Shuchao; Zhang, Peimin; Zhu, Yan

    2016-08-01

    In this work, poly(glycidylmethacrylate-divinylbenzene) microspheres were prepared and applied for the preparation of weak acid cation exchange stationary phases. Succinic anhydride, phthalic anhydride, and maleic anhydride were selected as carboxylation reagents to prepare three weak acid cation exchangers by direct chemical derivatization reaction without solvent or catalyst. The diameters and dispersity of the microspheres were characterized by scanning electron microscopy; the amount of accessible epoxy groups and mechanical stability were also measured. The weak acid cation exchangers were characterized by Fourier transform infrared spectroscopy; the content of carboxyl groups was measured by traditional acid base titration method. The chromatographic properties were characterized and compared by separating alkali, alkaline earth metal ions and ammonium and polar amines. The separation properties enhanced in the order of succinic anhydride, phthalic anhydride, and maleic anhydride modified poly(glycidylmethacrylate-divinylbenzene) cation exchangers. PMID:27288092

  6. Removal and Recovery of Chromium from Solutions Simulating Tannery Wastewater by Strong Acid Cation Exchanger

    Directory of Open Access Journals (Sweden)

    Gulten Cetin

    2013-01-01

    Full Text Available The process in this study was conducted on removal of chromium(III in a solution simulating a typical spent chrome tanning bath by the resin having matrix of styrene-divinylbenzene-based macroporous sulphonate, Amberjet 1200Na. The column experiments were carried out with the bed volumes of the resin as 751 mL and 1016 mL for different installation systems of the laboratory-scale pilot plant. The feeding solutions in the bed volumes of 200 and 190 were used for each installation system. The regeneration behaviour of the resin was determined by using reverse regeneration procedure with the solution of hydrogen peroxide in alkaline. The regeneration kinetics of the exhausted resin was examined with a range of the solutions having different concentration series of the alkaline hydrogen peroxide. The solutions of the basic chromium sulphate were recycled for each installation system following the regeneration cycles. The chromium ions in effluent were quantitatively eluted, and satisfactory removal of chromium(III and recovery of chromium(VI were achieved.

  7. Simple cation-exchange separation for ICP-MS measurement of 79Se in spent nuclear fuel sample

    International Nuclear Information System (INIS)

    A simple separation using a single cation-exchange column has been developed for the measurement of 79Se in a spent nuclear fuel solution with inductively coupled plasma mass spectrometry (ICP-MS). An irradiated UO2 pellet cut out from a PWR fuel rod was dissolved and used as a standard sample. A known amount of 82Se (20 ng) was added to the sample solution for the determination of the amount of 79Se by isotope dilution mass spectrometry (IDMS). The 82Se-spiked and non-spiked sample solutions were fed to each cation-exchange resin-packed column, followed by 1 M nitric acid for washing. The first 3 mL of the effluent was directly injected to the ICP-MS for obtaining the isotopic ratio of 79Se/82Se. The recovery of Se in the effluent was 92%, while no leakage of Gd3+ (158Gd) and Dy3+ (164Dy) which cause major isobaric interferences on 79Se and 82Se determinations by forming 158Gd2+ and 164Dy2+, respectively, was observed. In addition, the highly radioactive coexisting components e.g., Sr2+, Y3+, Cs+, and Ba2+ were retained on the cation-exchange resin, leading to the decrease in the surface dose rate of the sample solution from 0.3 mSv/h to a background level. The isotopic ratio 82Se/79Se of the non-spiked and the spiked fractions were 5.4 ± 1.0 and 13.7 ± 2.2, respectively. From these isotopic ratios, the amounts of 79Se and 82Se in the sample solution were calculated to be 2.4 ± 0.7 and 13.3 ± 4.6 ng, respectively. (author)

  8. Anion- or Cation-Exchange Membranes for NaBH4/H2O2 Fuel Cells?

    Science.gov (United States)

    Sljukić, Biljana; Morais, Ana L; Santos, Diogo M F; Sequeira, César A C

    2012-01-01

    Direct borohydride fuel cells (DBFC), which operate on sodium borohydride (NaBH4) as the fuel, and hydrogen peroxide (H2O2) as the oxidant, are receiving increasing attention. This is due to their promising use as power sources for space and underwater applications, where air is not available and gas storage poses obvious problems. One key factor to improve the performance of DBFCs concerns the type of separator used. Both anion- and cation-exchange membranes may be considered as potential separators for DBFC. In the present paper, the effect of the membrane type on the performance of laboratory NaBH4/H2O2 fuel cells using Pt electrodes is studied at room temperature. Two commercial ion-exchange membranes from Membranes International Inc., an anion-exchange membrane (AMI-7001S) and a cation-exchange membrane (CMI-7000S), are tested as ionic separators for the DBFC. The membranes are compared directly by the observation and analysis of the corresponding DBFC's performance. Cell polarization, power density, stability, and durability tests are used in the membranes' evaluation. Energy densities and specific capacities are estimated. Most tests conducted, clearly indicate a superior performance of the cation-exchange membranes over the anion-exchange membrane. The two membranes are also compared with several other previously tested commercial membranes. For long term cell operation, these membranes seem to outperform the stability of the benchmark Nafion membranes but further studies are still required to improve their instantaneous power load. PMID:24958292

  9. Effect of efficient microorganisms on cation exchange capacity in acacia seedlings (Acacia melanoxylon) for soil recovery in Mondonedo, Cundinamarca

    International Nuclear Information System (INIS)

    We determined the effect of efficient microorganisms (EM) on the cation exchange capacity for soil recovery in the municipality of Mondonedo, Cundinamarca. A greenhouse unit was installed in order to maintain stable conditions. After harvesting, sifted and homogenization of the soil sample, initial physical and chemical analyses were made. For the experimental units we used Acacia melanoxylon seedlings from Zabrinsky. A completely randomized design was done with eight treatments and three repetitions. For the maintenance and monitoring of the seedlings behaviour, a frequency of irrigation of three times per week was found. The application of the EM was done during three months: in the first month, it was applied four times (once a week); during the second month, it was applied twice (biweekly), and during the third month there was only one application. Additionally, every 15 days morphological analyses were made (number of leaves, branches and stem diameter). In the end, soil samples were taken from each plant pot. In the laboratory we analysed the cation exchange capacity, alkali ion exchange, saturation alkali, relations between elements and plant tissue. These were done using an atomic absorption spectrophotometer. Statistical analyses consisted on multiple comparisons test and variance tests, in order to find whether or not treatments exhibited significant differences. In that way, the best alternative for improving environmental quality of eroded soils as the Zabrinsky desert is the efficient microorganisms in 5% doses in irrigation water. Additionally, the cation exchange capacity must be enhanced using organic fertilizers (compost, mulch and gallinaza) in one pound doses, and chemical fertilizers: electrolytic Mn (0.0002 g), Cu (0.0002 g), Zn (0.0001 g), URFOS 44 (166.66 g) and klip-boro (5 g).

  10. The elution of erbium from a cation exchanger bed by means of the N-hydroxyethyl-ethylene-diamine triacetic acid

    International Nuclear Information System (INIS)

    A physicochemical study of the phenomena resulting when erbium is eluted from a cation-exchanger bed at a steady by means of the N-hydroxyethyl-ethylene-diamine-triacetic acid (HEDTA) is made. Two different retaining beds are used, a hydrogen bed, in which no ammonium passes through, and a zinc bed, which leaks ammonium ion. Good agreement between experimental and calculated values by using the equations deduced for the concentrations of the main species has been achieved, with errors around 1-2% in most of the experiments. (Author) 69 refs

  11. Preparation of decarboxylic-functionalized weak cation exchanger and application for simultaneous separation of alkali, alkaline earth and transition metals.

    Science.gov (United States)

    Peng, Yahui; Gan, Yihui; He, Chengxia; Yang, Bingcheng; Guo, Zhimou; Liang, Xinmiao

    2016-06-01

    A novel weak cation exchanger (WCX) with dicarboxyl groups functionalized has been developed by clicking mercaptosuccinic acid onto silica gel. The simple synthesis starts with modification of silica gel with triethoxyvinylsilane, followed by efficient coupling vinyl-bonded silica with mercaptosuccinic acid via a "thiol-ene" click reaction. The obtained WCX demonstrated good separation and high selectivity towards common metals. Simultaneous separation of 10 alkali, alkaline earth and transition metals was achieved within 12min. Ion exchange and complex mechanism dominates the separation process. Its utility was demonstrated for determination of metals in tap water. PMID:27130093

  12. Enhanced Transport of U(Vi) and Th(IV) Through Cation Exchange Membrane Using Electric Field

    International Nuclear Information System (INIS)

    Transport of ionic species through ion exchange membrane found several applications for water effluents purification and metal ion separation. To enhance the transport performance, the effect of electric field was introduced in this work. The transport of U (Vi) and Th(IV) species in nitric acid solutions across cation exchange membrane was investigated. In this concern, different parameters affecting the transport were studied. These parameters include; nitric acid concentration in the feed solution, stripping solution concentration and applied electric field. From the results obtained the permeability coefficient of U(Vi) and Th(IV) were calculated. Based on these information, a process for separation of thorium from uranium is developed

  13. Applications of Time-Resolved Synchrotron X-ray Diffraction to Cation Exchange, Crystal Growth and Biomineralization Reactions

    International Nuclear Information System (INIS)

    Advances in the design of environmental reaction cells and in the collection of X-ray diffraction data are transforming our ability to study mineral-fluid interactions. The resulting increase in time resolution now allows for the determination of rate laws for mineral reactions that are coupled to atomic-scale changes in crystal structure. Here we address the extension of time-resolved synchrotron diffraction techniques to four areas of critical importance to the cycling of metals in soils: (1) cation exchange; (2) biomineralization; (3) stable isotope fractionation during redox reactions; and (4) nucleation and growth of nanoscale oxyhydroxides.

  14. Application of silica hydrogel and silica gel comprising chromium(III) ions for synthesis of organo mineral cation exchangers

    International Nuclear Information System (INIS)

    Present article is devoted to application of silica hydrogel and silica gel comprising chromium(III) ions for synthesis of organo mineral cation exchangers. Thus, the polymerization of methacrylic acid on the surface of porous silica is studied. Porous sorbents are obtained by polymerizing of methacrylic acid in the medium of precipitated silica hydrogel treated by Cr(III) salts. The dependence of sorbents porosity on different factors, including conditions of hydrogel precipitation, its treatment by chromium salts, its ageing in the medium of methacrylic acid, quantity of methacrylic acid is studied as well.

  15. Coiled Brine Recovery Assembly (CoBRA) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Coiled Brine Recovery Assembly (CoBRA) project will result in a proof-of-concept demonstration for a lightweight, compact, affordable, regenerable and...

  16. Improvement of the thermochemical water splitting IS process by an electrochemical cell using a cation exchange membrane

    International Nuclear Information System (INIS)

    One of the key reactions for efficient hydrogen production through the water splitting IS (Iodine-Sulfur) process is the Bunsen reaction (SO2 + I2 + 2H2O = H2SO4 + 2HI). The Bunsen reaction was examined by an electrochemical cell featuring a cation exchange membrane as the separator, using sulfuric acid dissolving sulfur dioxide as the anolyte hydriodic acid dissolving iodine as the catholyte. In galvanostatic electrolysis, molality of H2SO4 in the anolyte and that of HI in the catholyte were increased up to 17.8 mol kg-H2O-1 and 14.9 mol kg-H2O-1 at I2/HI=1, respectively. These concentrations were far higher than the reported ones that were obtained by the Bunsen reaction carried out in the presence of large amount of iodine (e.g. I2/HI=4). The optimal concentrations of anolyte and catholyte were discussed by changing only one parameter. I2/HI ratio had little effects on the required total voltage suggesting that lower I2 concentration is desired for the efficient operation. H2SO4 concentration was found to be lower than 16 mol kg-H2O2-1 for anolyte. One of the important parameter that should be corrected was water content of the cation exchange membrane during the experimental especially for the higher concentrations of anolyte and catholyte. (author)

  17. Cation exchange reactions controlling desorption of 90Sr 2+ from coarse-grained contaminated sediments at the Hanford site, Washington

    Science.gov (United States)

    McKinley, J. P.; Zachara, J. M.; Smith, S. C.; Liu, C.

    2007-01-01

    Nuclear waste that bore 90Sr 2+ was accidentally leaked into the vadose zone at the Hanford site, and was immobilized at relatively shallow depths in sediments containing little apparent clay or silt-sized components. Sr 2+, 90Sr 2+, Mg 2+, and Ca 2+ was desorbed and total inorganic carbon concentration was monitored during the equilibration of this sediment with varying concentrations of Na +, Ca 2+. A cation exchange model previously developed for similar sediments was applied to these results as a predictor of final solution compositions. The model included binary exchange reactions for the four operant cations and an equilibrium dissolution/precipitation reaction for calcite. The model successfully predicted the desorption data. The contaminated sediment was also examined using digital autoradiography, a sensitive tool for imaging the distribution of radioactivity. The exchanger phase containing 90Sr was found to consist of smectite formed from weathering of mesostasis glass in basaltic lithic fragments. These clasts are a significant component of Hanford formation sands. The relatively small but significant cation exchange capacity of these sediments was thus a consequence of reaction with physically sequestered clays in sediment that contained essentially no fine-grained material. The nature of this exchange component explained the relatively slow (scale of days) evolution of desorption solutions. The experimental and model results indicated that there is little risk of migration of 90Sr 2+ to the water table.

  18. Uncertainties of Gaseous Oxidized Mercury Measurements Using KCl-Coated Denuders, Cation-Exchange Membranes, and Nylon Membranes: Humidity Influences.

    Science.gov (United States)

    Huang, Jiaoyan; Gustin, Mae Sexauer

    2015-05-19

    Quantifying the concentration of gaseous oxidized mercury (GOM) and identifying the chemical compounds in the atmosphere are important for developing accurate local, regional, and global biogeochemical cycles. The major hypothesis driving this work was that relative humidity affects collection of GOM on KCl-coated denuders and nylon membranes, both currently being applied to measure GOM. Using a laboratory manifold system and ambient air, GOM capture efficiency on 3 different collection surfaces, including KCl-coated denuders, nylon membranes, and cation-exchange membranes, was investigated at relative humidity ranging from 25 to 75%. Recovery of permeated HgBr2 on KCl-coated denuders declined by 4-60% during spikes of relative humidity (25 to 75%). When spikes were turned off GOM recoveries returned to 60 ± 19% of permeated levels. In some cases, KCl-coated denuders were gradually passivated over time after additional humidity was applied. In this study, GOM recovery on nylon membranes decreased with high humidity and ozone concentrations. However, additional humidity enhanced GOM recovery on cation-exchange membranes. In addition, reduction and oxidation of elemental mercury during experiments was observed. The findings in this study can help to explain field observations in previous studies. PMID:25877790

  19. An Investigation into the Effect of Cation-exchange on the Adsorption Performance of Indium-based Sodalite-ZMOF

    KAUST Repository

    Samin, Umer A.

    2016-04-13

    There is a pressing need for advanced solid-state materials that can be implemented in industrial gas separation processes to achieve separations with a significantly reduced energy input compared to what is typically required from current technologies. Although certain porous materials like zeolites bear some commercial significance for gas separation; their inherent lack of tunability limits the extent to which these materials may be exploited in industry. Zeolite-like Metal-Organic Frameworks (ZMOFs) are a sub-class of Metal-Organic Framework materials (MOFs) that show a structural semblance to zeolites while possessing the tunability advantages of MOF materials. ZMOFs which are topologically similar to certain zeolites can be functionalised and tuned in numerous ways to improve their gas separation properties. In this work, indium-based sod-ZMOF was tuned by cation-exchange and then characterised by different experimental tools such as single-crystal x-ray diffraction, elemental analysis and gas adsorption. It was found that various parameters like the choice of cation, the concentration of salt solution and the choice of solvent had a significant bearing on the cation-exchange of sod-ZMOF and its subsequent adsorption properties.

  20. Toward Separating Alpha-lactalbumin and Beta-lactoglobulin Proteins from Whey through Cation-exchange Adsorption

    Science.gov (United States)

    El-Sayed, Mayyada; Chase, Howard

    2009-05-01

    This paper describes the cation-exchange adsorption of the two major whey proteins, alpha-lactalbumin (ALA) and beta-lactoglobulin (BLG) with the purpose of establishing a process for isolating them from cow's milk whey. The single- and two-component adsorption of 1.5 mg/ml ALA and 3 mg/ml BLG to the cation-exchanger SP Sepharose FF at 20° C using 0.1 M acetate buffer of pH 3.7 was studied. Langmuir isotherm parameters were determined for the pure proteins. In two-component systems, BLG breakthrough curve exhibited an overshoot phenomenon that gave evidence for the presence of a competitive adsorption between the two proteins. Complete separation occurred and it was possible to obtain each of the two proteins in a pure form. The process was then applied to a whey concentrate mixture where incomplete separation took place. However, BLG was produced with 95% purity and a recovery of 80%, while ALA showed an 84% recovery with low purity.

  1. Synthesis, dehydration studies, and cation-exchange behavior of a new phase of niobium(V) phosphate

    International Nuclear Information System (INIS)

    Twenty-three samples of niobium(V) phosphate have been synthesized under different conditions using niobium sulfate and phosphoric acid solutions. The amorphous sample having the ion-exchange capacity of 1.06 mEq g-1 and niobium to phosphorus mole ratio of 0.670 was studied in detail for its cation-exchange behavior. Molar distribution coefficients for 25 cations have been studied on this gel at pH 1,2,3, and 5.5. Four quantitative separations of Mg2+-Ca2+, Mg2+-Ba2+, Zn2+-Cd2+, and Bi3+-Zn2+ have successfully been achieved on it. The properties of this sample have been compared with those of niobium arsenate, niobium antimonate, and niobium molybdate. A tentative structural formula is proposed for this sample of niobium phosphate on the basis of chemical composition, cation-exchange capacity, pH-titration, IR spectra, T.G.A., water absorption, and heat treatment data. (author)

  2. Coiled Brine Recovery Assembly (CoBRA): A New Approach to Recovering Water from Wastewater Brines

    Science.gov (United States)

    Pensinger, Stuart J.

    2015-01-01

    Brine water recovery represents a current technology gap in water recycling for human spaceflight. The role of a brine processor is to take the concentrated discharge from a primary wastewater processor, called brine, and recover most of the remaining water from it. The current state-of-the-art primary processor is the ISS Urine Processor Assembly (UPA) that currently achieves 70% water recovery. Recent advancements in chemical pretreatments are expected to increase this to 85% in the near future. This is a welcome improvement, yet is still not high enough for deep space transit. Mission architecture studies indicate that at least 95% is necessary for a Mars mission, as an example. Brine water recovery is the technology that bridges the gap between 85% and 95%, and moves life support systems one step closer to full closure of the water loop. Several brine water recovery systems have been proposed for human spaceflight, most of them focused on solving two major problems: operation in a weightless environment, and management and containment of brine residual. Brine residual is the leftover byproduct of the brine recovery process, and is often a viscous, sticky paste, laden with crystallized solid particles. Due to the chemical pretreatments added to wastewater prior to distillation in a primary processor, these residuals are typically toxic, which further complicates matters. Isolation of crewmembers from these hazardous materials is paramount. The Coiled Brine Recovery Assembly (CoBRA) is a recently developed concept from the Johnson Space Center that offers solutions to these challenges. CoBRA is centered on a softgoods evaporator that enables a passive fill with brine, and regeneration by discharging liquid brine residual to a collection bag. This evaporator is meant to be lightweight, which allows it to be discarded along with the accumulated brine solids contained within it. This paper discusses design and development of a first CoBRA prototype, and reports

  3. Transport of Zinc and Copper through Impregnated Cation-Exchange Membrane with 8-Hydroxyquinoline Using Electric Field

    International Nuclear Information System (INIS)

    The transport of Zn(II) and Cu(II) species across impregnated cation-exchange membrane with 8-hydroxy-quinoline in xylene was investigated. To accelerate the transport of ions, the effect of electric field was introduced. Certain parameters that affect the transport were studied. These parameters include; hydrochloric acid concentration in the feed solution, stripping solution concentration, voltage and 8-hydroxyquinoline concentration. The flux values of Zn(II) and Cu(II) were 3.7x10-9and 3.6x10-10g-eq.cm-2s-1, respectively. The separation of Zn(II) from Cu(II)was performed selectively by this technique and the use of electric field accelerated the ions transport

  4. Comparison of Reactive Mercury Concentrations Measured Simultaneously Using KCl-coated Denuders, Nylon Membranes, and Cation Exchange Membranes

    Science.gov (United States)

    Gustin, M. S.; Huang, J.; Miller, M. B.; Weiss-Penzias, P. S.

    2012-12-01

    There is much debate about the chemistry of reactive gaseous and particle bound mercury (Hg) in the atmosphere, and the processes associated with formation. In addition, there are concerns regarding the interferences and calibration of the widely used Tekran® 2537/1130/1135 Hg measurement system. To investigate these we developed simple laboratory and field sampling systems designed to collect and analyze reactive Hg (Hg (II), Hg (I) and/or particle bound). A manifold system was applied in the laboratory, and in the field, in-series and -parallel membranes, flow controllers and pumps were utilized. Both systems actively collected reactive Hg using nylon membranes and cation exchange membranes alongside measurements made using the Tekran® system. The analytical system consisted of step wise 2.5 minute thermo-desorption and Hg quantification by cold vapor atomic fluorescence. In the laboratory, we compared the efficiency of these surfaces for collection of HgO, HgCl2, and HgBr2 when permeated into Hg and oxidant free air, and ambient filtered air. Other tests are ongoing. Thus far, results show concentrations measured by the cation exchange membrane were two-to-three fold greater than that measured by the nylon membranes, and three-to -four fold greater than that measured by the KCl-coated annual denuder. Thermo-desorption profiles obtained using nylon membranes show slightly different patterns associated with the reactive Hg compounds as permeated and tested. Field measurements were made at two locations in Reno, Nevada (a high traffic site and an agricultural area) and at Elkhorn Slough, California (marine site). Desorption profiles from nylon membrane differed by site and by time of year. Although the influence of aerosol on this measurement has not been explored, field results suggest different forms of reactive Hg were present in the atmosphere as a function of season and location.

  5. Advance chromatin extraction enhances performance and productivity of cation exchange chromatography-based capture of Immunoglobulin G monoclonal antibodies.

    Science.gov (United States)

    Nian, Rui; Gagnon, Pete

    2016-07-01

    The impact of host cell-derived chromatin was investigated on the performance and productivity of cation exchange chromatography as a method for capture-purification of an IgG monoclonal antibody. Cell culture supernatant was prepared for loading by titration to pH 6.0, dilution with water to a conductivity of 4mS/cm, then microfiltration to remove solids. DNA content was reduced 99% to 30ppm, histone host cell protein content by 76% to 6300ppm, non-histone host cell protein content by 15% to 321,000ppm, and aggregates from 33% to 15%. IgG recovery was 83%. An alternative preparation was performed, adding octanoic acid, allantoin, and electropositive particles to the harvest at pH 5.3, then removing solids. DNA content was reduced to<1 ppb, histones became undetectable, non-histones were reduced to 24,000ppm, and aggregates were reduced to 2.4%. IgG recovery was 95%. This treatment increased dynamic capacity (DBC) of cation exchange capture to 173g/L and enabled the column to reduce non-histone host proteins to 671ppm. Step recovery was 99%. A single multimodal polishing step further reduced them to 15ppm and aggregates to <0.1%. Overall process recovery was 89%. Productivity at feed stream IgG concentrations of 5-10g/L was roughly double the productivity of a same-size protein A column with a DBC of 55g/L. PMID:27247214

  6. Common Ion Effects In Zeoponic Substrates: Dissolution And Cation Exchange Variations Due to Additions of Calcite, Dolomite and Wollastonite

    Science.gov (United States)

    Beiersdorfer, R. E.; Ming, D. W.; Galindo, C., Jr.

    2003-01-01

    c1inoptilolite-rich tuff-hydroxyapatite mixture (zeoponic substrate) has the potential to serve as a synthetic soil-additive for plant growth. Essential plant macro-nutrients such as calcium, phosphorous, magnesium, ammonium and potassium are released into solution via dissolution of the hydroxyapatite and cation exchange on zeolite charged sites. Plant growth experiments resulting in low yield for wheat have been attributed to a Ca deficiency caused by a high degree of cation exchange by the zeolite. Batch-equilibration experiments were performed in order to determine if the Ca deficiency can be remedied by the addition of a second Ca-bearing, soluble, mineral such as calcite, dolomite or wollastonite. Variations in the amount of calcite, dolomite or wollastonite resulted in systematic changes in the concentrations of Ca and P. The addition of calcite, dolomite or wollastonite to the zeoponic substrate resulted in an exponential decrease in the phosphorous concentration in solution. The exponential rate of decay was greatest for calcite (5.60 wt. % -I), intermediate for wollastonite (2.85 wt.% -I) and least for dolomite (1.58 wt.% -I). Additions of the three minerals resulted in linear increases in the calcium concentration in solution. The rate of increase was greatest for calcite (3.64), intermediate for wollastonite (2.41) and least for dolomite (0.61). The observed changes in P and Ca concentration are consistent with the solubilities of calcite, dolomite and wollastonite and with changes expected from a common ion effect with Ca. Keywords: zeolite, zeoponics, common-ion effect, clinoptilolite, hydroxyapatite

  7. Enhanced photocatalytic activity of chromium(VI) reduction and EDTA oxidization by photoelectrocatalysis combining cationic exchange membrane processes

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Hung-Te, E-mail: der11065@hotmail.com [Institute of Environmental Engineering and Management, National Taipei University of Technology, No. 1, Sec. 3, Chung-Hsiao E. Rd., Taipei 106, Taiwan (China); Chen, Shiao-Shing, E-mail: f10919@ntut.edu.tw [Institute of Environmental Engineering and Management, National Taipei University of Technology, No. 1, Sec. 3, Chung-Hsiao E. Rd., Taipei 106, Taiwan (China); Tang, Yi-Fang, E-mail: sweet39005@hotmail.com [Institute of Environmental Engineering and Management, National Taipei University of Technology, No. 1, Sec. 3, Chung-Hsiao E. Rd., Taipei 106, Taiwan (China); Hsi, Hsing-Cheng, E-mail: hchsi@ntut.edu.tw [Institute of Environmental Engineering and Management, National Taipei University of Technology, No. 1, Sec. 3, Chung-Hsiao E. Rd., Taipei 106, Taiwan (China)

    2013-03-15

    Highlights: ► Chromium(VI) reduction and EDTA oxidization were conducted by photoelectrocatalysis. ► Apply the concept of cationic exchange membrane to enhance the conversion efficiency. ► The optimum TiO{sub 2} loading of 1 g/L was observed at acidic pH with current density 4 mA/cm{sup 2}. ► Transformation pathway of EDTA was determined from analyzed byproducts and molecular orbital package analysis. -- Abstract: A novel technology of photoelectrocatalysis (PEC) combining with cationic exchange membrane (CEM) was proposed for simultaneous reduction of chromium(VI) and oxidization of EDTA. The application of CEM was used to enhance the efficiency for prevention of the re-oxidation of reduced chromium with the electron–hole pairs. In this study, effects of current density, pH, TiO{sub 2} dosage, hydraulic retention time (HRT), light intensity and EDTA/Cr(VI) molar ratio were all investigated. The results showed that the optimum conversion efficiency occurred at 4 mA/cm{sup 2} with the presence of CEM. Higher conversion efficiencies were observed at lower pH due to the electrostatic attractions between positive charged Ti-OH{sub 2}{sup +}, and negatively charged Cr(VI) and EDTA. The optimum TiO{sub 2} loading of 1 g/L was depended mainly on the acidic pH range, especially at higher HRT and irradiation intensity. In addition, higher EDTA/Cr(VI) molar ratio enhanced the reduction efficiency of Cr(VI), indicating EDTA plays the role of hole scavenger in this system. Moreover, incomplete EDTA decomposition contributes to the occurrence of intermediates, including nitrilotriacetic acid, iminodiacetic acid, glycine, oxamic acid, lyoxylic acid, oxalic acid, acetic acid and formic acid, as identified by GC/MS. Consequently, transformation pathway was determined from these analyzed byproducts and molecular orbital package analysis.

  8. Quantification of melamine in human urine using cation-exchange based high performance liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Panuwet, Parinya; Nguyen, Johnny V; Wade, Erin L; D'Souza, Priya E; Ryan, P Barry; Barr, Dana Boyd

    2012-03-01

    Melamine and cyanuric acid have been implicated as adulterants in baby formula in China and pet foods in North America. In China, the effect of melamine or melamine-cyanuric acid adulteration lead to kidney stone development and acute renal failure in thousands of Chinese infants. A selective and sensitive analytical method was developed to measure melamine in human urine in order to evaluate the extent of potential health implications resulting from the consumption of these types of adulterated products in the general US population. This method involves extracting melamine from human urine using cation-exchange solid-phase extraction, chromatographically separating it from its urinary matrix co-extractants on a silica-based, strong-cation exchange analytical column using high performance liquid chromatography, and analysis using positive mode electrospray ionization tandem mass spectrometry. Quantification was performed using modified, matrix-based isotope dilution calibration covering the concentration range of 0.50-100 ng/mL. The limit of detection, calculated using replicates of blank and low level spiked samples, was 0.66 ng/mL and the relative standard deviations were between 6.89 and 14.9%. The relative recovery of melamine was 101-106%. This method was tested for viability by analyzing samples collected from the general US population. Melamine was detected in 76% of the samples tested, with a geometric mean of 2.37 ng/mL, indicating that this method is suitable for reliably detecting background exposures to melamine or other chemicals from which it can be derived. PMID:22309774

  9. Enhanced photocatalytic activity of chromium(VI) reduction and EDTA oxidization by photoelectrocatalysis combining cationic exchange membrane processes

    International Nuclear Information System (INIS)

    Highlights: ► Chromium(VI) reduction and EDTA oxidization were conducted by photoelectrocatalysis. ► Apply the concept of cationic exchange membrane to enhance the conversion efficiency. ► The optimum TiO2 loading of 1 g/L was observed at acidic pH with current density 4 mA/cm2. ► Transformation pathway of EDTA was determined from analyzed byproducts and molecular orbital package analysis. -- Abstract: A novel technology of photoelectrocatalysis (PEC) combining with cationic exchange membrane (CEM) was proposed for simultaneous reduction of chromium(VI) and oxidization of EDTA. The application of CEM was used to enhance the efficiency for prevention of the re-oxidation of reduced chromium with the electron–hole pairs. In this study, effects of current density, pH, TiO2 dosage, hydraulic retention time (HRT), light intensity and EDTA/Cr(VI) molar ratio were all investigated. The results showed that the optimum conversion efficiency occurred at 4 mA/cm2 with the presence of CEM. Higher conversion efficiencies were observed at lower pH due to the electrostatic attractions between positive charged Ti-OH2+, and negatively charged Cr(VI) and EDTA. The optimum TiO2 loading of 1 g/L was depended mainly on the acidic pH range, especially at higher HRT and irradiation intensity. In addition, higher EDTA/Cr(VI) molar ratio enhanced the reduction efficiency of Cr(VI), indicating EDTA plays the role of hole scavenger in this system. Moreover, incomplete EDTA decomposition contributes to the occurrence of intermediates, including nitrilotriacetic acid, iminodiacetic acid, glycine, oxamic acid, lyoxylic acid, oxalic acid, acetic acid and formic acid, as identified by GC/MS. Consequently, transformation pathway was determined from these analyzed byproducts and molecular orbital package analysis

  10. The importance of cerium substituted phosphates as cation exchanger some unique properties and related application potentials

    International Nuclear Information System (INIS)

    Seven different samples of an inorganic ion exchanger, cerium phosphate, suitable for column use have been prepared under varying conditions. The property of these exchangers has been characterized by Inductively Coupled Plasma Spectroscopy. These exchangers are stable in water, dilute mineral acids, ethanol, methanol, acetone and ether. However, in concentrated HCl and HNO3 they decompose. They retain about 50% of their exchange value after drying at 80 degC, and can be regenerated twice without any decrease in exchange capacity. The distribution coefficient measurements for alkaline earth metals, tellurium, iodine and molybdenum using these seven ion exchangers were studied. This revealed the relative affinity for each exchanger, where the sorption in general was most effective at P H 6-8. The titration curves of cerium phosphate (disodium) with alkaline earth metals showed that the selectivity sequence Ba2+>Sr2+>CA2+>Mg2+ is observed. Furthermore, it could be deduced that the adsorption of alkaline earth metal cations greatly depends on the cation. These studies have also shown that cerium phosphates with divalent ions are strongly preferred to monovalent ones. Therefore, as for the cerium phosphates with large monovalent ions, the lack of exchange for Ba2+, Mg2+ or other alkaline earth metal ions should be essentially due to steric hindrance and this could include any one of the following: the large crystalline radius of metal ions or large hydrated ionic radius and high energy of hydration for other divalent ions. Three binary separations of TeIV - MoIV, TeIV -I1 has been developed and the recovery ranging from 90 to 100% has been achieved on cerium phosphate (disodium) columns

  11. Ergot alkaloids in rye flour determined by solid-phase cation-exchange and high-pressure liquid chromatography with fluorescence detection

    DEFF Research Database (Denmark)

    Storm, Ida Marie Lindhardt Drejer; Rasmussen, Peter Have; Strobel, B.W.;

    2008-01-01

    Ergot alkaloids are mycotoxins that are undesirable contaminants of cereal products, particularly rye. A method was developed employing clean-up by cation-exchange solid-phase extraction, separation by high-performance liquid chromatography under alkaline conditions and fluorescence detection. It...

  12. Onset of size independent cationic exchange in nano-sized CoFe2O4 induced by electronic excitation

    International Nuclear Information System (INIS)

    Highlights: • Electronic excitation induced crystalline order in CoFe2O4. • No change of metallic valence state under dense electronic excitation. • Size independent control of cations in CoFe2O4. - Abstract: Present work investigates electronic excitation induced cationic exchange phenomena in nano-sized cobalt ferrites using Mössabaur and X-ray absorption spectroscopies. The electronic excitations were produced by irradiation of 100 MeV O+7 at different fluences ranging from 1 × 1011 to 1 × 1014 ions/cm2. Cubic spinel phase of cobalt ferrite remains preserved after irradiation. However, attributes of crystalline disorder were observed in irradiated materials. Crystallite size remain almost same for pristine and irradiated materials. X-ray absorption fine structure measurements show the preservation of valence state and spin state of metal ions under intense electronic excitation. These measurements also envisage bond breaking process induced by the electronic excitation. Mössbauer spectroscopic measurements also corroborate with the fine structure measurements that the valence state of Fe remains same after irradiation. Paramagnetic doublet which presents in the Mössabaur spectrum of pristine material disappears after irradiation, showing the evolution of irradiation induced magnetic ordering. Fe3+ ion increases with irradiation at octahedral site of spinel lattice. Magnetization of the material slightly increases after irradiation at the fluence of 5 × 1013 and 1 × 1014 ions/cm2

  13. A continuous process for biodiesel production in a fixed bed reactor packed with cation-exchange resin as heterogeneous catalyst.

    Science.gov (United States)

    Feng, Yaohui; Zhang, Aiqing; Li, Jianxin; He, Benqiao

    2011-02-01

    Continuous esterification of free fatty acids (FFA) from acidified oil with methanol was carried out with NKC-9 cation-exchange resin in a fixed bed reactor with an internal diameter of 25 mm and a height of 450 mm to produce biodiesel. The results showed that the FFA conversion increased with increases in methanol/oil mass ratio, reaction temperature and catalyst bed height, whereas decreased with increases in initial water content in feedstock and feed flow rate. The FFA conversion kept over 98.0% during 500 h of continuous esterification processes under 2.8:1 methanol to oleic acid mass ratio, 44.0 cm catalyst bed height, 0.62 ml/min feed flow rate and 65°C reaction temperature, showing a much high conversion and operational stability. Furthermore, the loss of sulfonic acid groups from NKC-9 resin into the production was not found during continuous esterification. In sum, NKC-9 resin shows the potential commercial applications to esterification of FFA. PMID:21078550

  14. Cation Exchange Strategy for the Encapsulation of a Photoactive CO-Releasing Organometallic Molecule into Anionic Porous Frameworks.

    Science.gov (United States)

    Carmona, Francisco J; Rojas, Sara; Sánchez, Purificación; Jeremias, Hélia; Marques, Ana R; Romão, Carlos C; Choquesillo-Lazarte, Duane; Navarro, Jorge A R; Maldonado, Carmen R; Barea, Elisa

    2016-07-01

    The encapsulation of the photoactive, nontoxic, water-soluble, and air-stable cationic CORM [Mn(tacn)(CO)3]Br (tacn = 1,4,7-triazacyclononane) in different inorganic porous matrixes, namely, the metalorganic framework bio-MOF-1, (NH2(CH3)2)2[Zn8(adeninate)4(BPDC)6]·8DMF·11H2O (BPDC = 4,4'-biphenyldicarboxylate), and the functionalized mesoporous silicas MCM-41-SO3H and SBA-15-SO3H, is achieved by a cation exchange strategy. The CO release from these loaded materials, under simulated physiological conditions, is triggered by visible light. The results show that the silica matrixes, which are unaltered under physiological conditions, slow the kinetics of CO release, allowing a more controlled CO supply. In contrast, bio-MOF-1 instability leads to the complete leaching of the CORM. Nevertheless, the degradation of the MOF matrix gives rise to an enhanced CO release rate, which is related to the presence of free adenine in the solution. PMID:27291890

  15. Enhanced photocatalytic activity of chromium(VI) reduction and EDTA oxidization by photoelectrocatalysis combining cationic exchange membrane processes.

    Science.gov (United States)

    Hsu, Hung-Te; Chen, Shiao-Shing; Tang, Yi-Fang; Hsi, Hsing-Cheng

    2013-03-15

    A novel technology of photoelectrocatalysis (PEC) combining with cationic exchange membrane (CEM) was proposed for simultaneous reduction of chromium(VI) and oxidization of EDTA. The application of CEM was used to enhance the efficiency for prevention of the re-oxidation of reduced chromium with the electron-hole pairs. In this study, effects of current density, pH, TiO2 dosage, hydraulic retention time (HRT), light intensity and EDTA/Cr(VI) molar ratio were all investigated. The results showed that the optimum conversion efficiency occurred at 4mA/cm(2) with the presence of CEM. Higher conversion efficiencies were observed at lower pH due to the electrostatic attractions between positive charged TiOH2(+), and negatively charged Cr(VI) and EDTA. The optimum TiO2 loading of 1g/L was depended mainly on the acidic pH range, especially at higher HRT and irradiation intensity. In addition, higher EDTA/Cr(VI) molar ratio enhanced the reduction efficiency of Cr(VI), indicating EDTA plays the role of hole scavenger in this system. Moreover, incomplete EDTA decomposition contributes to the occurrence of intermediates, including nitrilotriacetic acid, iminodiacetic acid, glycine, oxamic acid, lyoxylic acid, oxalic acid, acetic acid and formic acid, as identified by GC/MS. Consequently, transformation pathway was determined from these analyzed byproducts and molecular orbital package analysis. PMID:23380448

  16. CO 2 adsorption in mono-, di- and trivalent cation-exchanged metal-organic frameworks: A molecular simulation study

    KAUST Repository

    Chen, Yifei

    2012-02-28

    A molecular simulation study is reported for CO 2 adsorption in rho zeolite-like metal-organic framework (rho-ZMOF) exchanged with a series of cations (Na +, K +, Rb +, Cs +, Mg 2+, Ca 2+, and Al 3+). The isosteric heat and Henry\\'s constant at infinite dilution increase monotonically with increasing charge-to-diameter ratio of cation (Cs + < Rb + < K + < Na + < Ca 2+ < Mg 2+ < Al 3+). At low pressures, cations act as preferential adsorption sites for CO 2 and the capacity follows the charge-to-diameter ratio. However, the free volume of framework becomes predominant with increasing pressure and Mg-rho-ZMOF appears to possess the highest saturation capacity. The equilibrium locations of cations are observed to shift slightly upon CO 2 adsorption. Furthermore, the adsorption selectivity of CO 2/H 2 mixture increases as Cs + < Rb + < K + < Na + < Ca 2+ < Mg 2+ ≈ Al 3+. At ambient conditions, the selectivity is in the range of 800-3000 and significantly higher than in other nanoporous materials. In the presence of 0.1% H 2O, the selectivity decreases drastically because of the competitive adsorption between H 2O and CO 2, and shows a similar value in all of the cation-exchanged rho-ZMOFs. This simulation study provides microscopic insight into the important role of cations in governing gas adsorption and separation, and suggests that the performance of ionic rho-ZMOF can be tailored by cations. © 2012 American Chemical Society.

  17. Kinetics, thermodynamics and surface heterogeneity assessment of uranium(VI) adsorption onto cation exchange resin derived from a lignocellulosic residue

    International Nuclear Information System (INIS)

    A new cation exchange resin (PGTFS-COOH) having a carboxylate functional group at the chain end was prepared by grafting poly(hydroxyethylmethacrylate) onto tamarind fruit shell, TFS (a lignocellulosic residue) using potassium peroxydisulphate-sodium thiosulphate redox initiator, and in the presence of N,N'-methylenebisacrylamide (MBA) as a crosslinking agent, followed by functionalisation. The adsorbent was characterized with the help of FTIR, XRD, scanning electron micrographs (SEM), and potentiometric titrations. The kinetic and isotherm data, obtained at optimum pH value 6.0 at different temperatures could be fitted with pseudo-second-order equation and Sips isotherm model, respectively. An increase in temperature induces positive effect on the adsorption process. The calculated activation energy of adsorption (Ea, 18.67 kJ/mol) indicates that U(VI) adsorption was largely due to diffusion-controlled process. The values of adsorption enthalpy, Gibbs free energy, and entropy were calculated using thermodynamic function relationships. The decrease in adsorption enthalpy with increasing U(VI) uploading on the adsorbent, reflects the surface energetic heterogeneity of the adsorbent. The isosteric heat of adsorption was quantitatively correlated with the fractional loading for the U(VI) ions adsorption onto PGTFS-COOH. The results showed that the PGTFS-COOH possessed heterogeneous surface with sorption sites having different activities.

  18. Cation exchange capacity (Qv) estimation in shaly sand reservoirs: case studies in the Junggar Basin, northwest China

    Science.gov (United States)

    Wang, Liang; Mao, Zhi-Qiang; Sun, Zhong-Chun; Luo, Xing-Ping; Deng, Ren-Shuang; Zhang, Ya-Hui; Ren, Bing

    2015-10-01

    Cation exchange capacity (Qv) is a key parameter in resistivity-based water saturation models of shaly sand reservoirs, and the accuracy of Qv calculation is crucial to the prediction of saturations of oil and gas. In this study, a theoretical expression of Qv in terms of shaly sand permeability (Kshaly-sand), total porosity (ϕt), and salinity of formation water (S) is deduced based on the capillary tube model and the physics volume model. Meanwhile, the classical Schlumberger-Doll research (SDR) model has been introduced to estimate Kshaly-sand. On this basis, a novel technique to estimate Qv from nuclear magnetic resonance (NMR) logs is proposed, and the corresponding model is also established, whose model parameters are calibrated by laboratory Qv and NMR measurements of 15 core samples from the Toutunhe formation of the Junggar Basin, northwest China. Based on the experimental data sets, this technique can be extended to reservoir conditions to estimate continuous Qv along the intervals. The processing results of field examples illustrate that the Qv calculated from field NMR logs are consistent with the analyzed results, with the absolute errors within the scope of  ±0.1 mmol cm-3 for the majority of core samples.

  19. Simultaneous determinations of Cr(VI) and Cr(III) by ion-exclusion/cation-exchange chromatography with an unmodified silica-gel column.

    Science.gov (United States)

    Hirata, Shizuko; Kozaki, Daisuke; Sakanishi, Kinya; Nakagoshi, Nobukazu; Tanaka, Kazuhiko

    2010-01-01

    In order to characterize the ion-exclusion and cation-exchange properties of an unmodified silica-gel column, the retention behaviors of Cr(VI) and Cr(III) ions were investigated using a Develosil 30-5 (150 x 4.6 mm i.d.) in the acidic region. Cr(VI) was separated from other anions by an ion-exclusion and ion-adsorption mechanism, and Cr(III) was separated from other cations with a cation-exchange mechanism. When using 2.0 mM oxalic acid (pH 2.6) as an eluent, a good separation of Cr(VI) and Cr(III) was obtained using conductimetric detection in 12 min. The method was successfully applied to the simultaneous determinations of Cr(VI) and Cr(III) added into tap-water and river-water samples. PMID:20215693

  20. Cation exchange separation of 61Cu2+ from natCo targets and preparation of 61Cu-DOTA-HSA as a blood pool agent

    International Nuclear Information System (INIS)

    An improved method for isolation of 61Cu2+ from a natCo target using cation exchange was developed. 61Cu2+ was eluted from a cation exchange resin column by 0.2 M HCl with 90% acetone, while Co2+ remained on the column. The whole separation process was completed within 50 min at more than 72% yield. The Co2+ impurity level in 61Cu2+ solution was reduced to less than 0.1 ppm. Highly pure 61Cu2+ solution was then applied to prepare 61Cu-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA)-human serum albumin (HSA) which showed good blood pool imaging properties

  1. Application of mixed-mode, solid-phase extraction in environmental and clinical chemistry. Combining hydrogen-bonding, cation-exchange and Van der Waals interactions

    Science.gov (United States)

    Mills, M.S.; Thurman, E.M.; Pedersen, M.J.

    1993-01-01

    Silica- and styrene-divinylbenzene-based mixed-mode resins that contain C8, C18 and sulphonated cation-exchange groups were compared for their efficiency in isolation of neutral triazine compounds from water and of the basic drug, benzoylecgonine, from urine. The triazine compounds were isolated by a combination of Van der Waals and hydrogen-bonding interactions, and benzoylecgonine was isolated by Van der Waals interactions and cation exchange. All analytes were eluted with a polar organic solvent contaning 2% ammonium hydroxide. Larger recoveries (95%) were achieved on copolymerized mixed-mode resins where C18 and sulfonic acid are in closer proximity than on 'blended' mixed-mode resins (60-70% recovery).

  2. Improved brine recycling during nitrate removal using ion exchange.

    Science.gov (United States)

    Bae, Byung-Uk; Jung, Yoo-Hoon; Han, Woon-Woo; Shin, Hang-Sik

    2002-07-01

    Ion exchange technology is currently the best for removing nitrate from drinking water. However, problems related to the disposal of spent brine from regeneration of exhausted resins must be overcome so that ion exchange can be applied more widely and economically, especially in small communities. For this purpose, a novel spent brine recycling system using combined biological denitrification and sulfate reduction processes was developed for more efficient reuse of brine. A granular activated carbon (GAC) adsorption column was introduced as an additional step to prevent contamination of resins by bio-polymers and dissolved organics present in the bio-reactor effluent. Two upflow sludge blanket reactors (USBRs) were operated in series for 166 days to provide denitrification and sulfate reduction. The denitrification reactor provided a nitrate removal efficiency of 96% at a nitrate-N loading rate of 5.4 g NO3(-)-N/l d. The sulfate reduction efficiency of the sulfate reduction reactor remained approximately 62% at a sulfate loading rate of 1.8 g SO4(2-)/l d. Five ion exchange columns containing A520E resins were repeatedly operated in up to 25 cycles of service and regeneration using five kinds of brine: one virgin 3% NaCl and four differently recycled spent brines. Throughput decreased remarkably when the biologically recycled brine was not treated with the GAC column, probably due to the presence of bio-polymers and dissolved organic compounds. The sulfate reduction reactor placed after the denitrification step increased the bicarbonate concentration, which could be used as a co-regenerant with chloride. The inclusion of the sulfate reduction reactor into the conventional brine recycling system allowed more efficient reuse of brine, resulting in both reduced salt consumption and brine discharge. PMID:12188132

  3. 离子色谱分离法提纯异麦芽低聚糖%Purification of isomalto-oligosaccharide by cation exchange chromatography

    Institute of Scientific and Technical Information of China (English)

    姜守霞; 励雯波; 钟振声

    2003-01-01

    The purification of isomalto-oligsaccharide syrup using cation exchange resin was smdiied. The experiments showed that, when 35 ml raw material was used, the optimal purification result could be achieved on the resin column of 9 × 4000 mm with eluting rate 9 ml/min at 71℃ .The content of gluecose could be decreased whist the content of active components would be relatively increased.The purity of isomalto-oligsaccharide could be further increased by re-purification.

  4. Effects of Land Use Practices on the Organic Carbon Content, Cation Exchange Capacity and Aggregate Stability of Soils in the Catchment Zones

    OpenAIRE

    Mosayeb Heshmati; Arifin Abdu; Shamshuddin Jusop; Nik M. Majid

    2011-01-01

    Problem statement: Land use practice leads to changes in the physico-chemical properties of soils, such as Soil Organic Carbon (SOC), Cation Exchange Capacity (CEC) and Soil Aggregate Stability (SAS) that cause soil erosion. Approach: Merek catchment, Iran suffers from land degradation due to poor land use practice. A study was carried out with the objectives: (i) to determine soil nutrient status in different agro-ecological zones in Merek catchment; and (ii) to evaluate the influence of lan...

  5. Ionic Liquid Synergistic Cation-Exchange System for the Selective Extraction of Lanthanum(III) Using 2-Thenoyltrifluoroacetone and 18-Crown-6

    OpenAIRE

    Hirayama, Naoki; Okamura, Hiroyuki; Kidani, Keiji; Imura, Hisanori

    2008-01-01

    A novel synergistic extraction system was investigated for the possible selective separation of light lanthanoids using an ionic liquid, 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, as an extraction solvent and 2-thenoyltrifluoroacetone and 18-crown-6 as extractants. Trivalent lanthanum was efficiently extracted as a cationic ternary complex by the cation-exchange process, whereas europium and lutetium showed relatively low extractability without forming respective ternary ...

  6. On-line coupling of an ion chromatograph to the ICP-MS: Separations with a cation exchange chromatography column

    Energy Technology Data Exchange (ETDEWEB)

    Roellin, Stefan [Studsvik Nuclear AB, Nykoeping (Sweden)

    1999-12-01

    An ion chromatography system was coupled on-line to the ICP-MS. All separations were made with a cation exchange chromatography column. Fundamental laws about elution parameters affecting individual retention times and elution forms are explained by applying a proper ion exchange mechanism for the isocratic elution (separations with constant eluent concentration) of mono-, di-, tri-, and tetravalent cations and the actinide species MO{sub 2}{sup +} and MO{sub 2}{sup 2+}. A separation method with two eluents has been investigated to separate mono- from divalent ions in order to separate isobaric overlaps of Rb/Sr and Cs/Ba. The ions normally formed by actinides in aqueous solutions in the oxidation states III to VI are M{sup 3+}, M{sup 4+}, MO{sub 2}{sup +} and MO{sub 2}{sup 2+} respectively. Elution parameters were investigated to separate all four actinide species from each other in order to separate isobaric overlaps of the actinides Np, Pu, U and Am. A major question of concern over the possible release of actinides to the environment is the speciation of actinides within their four possible oxidation states. To check the possibility of speciation analysis with ion chromatography, a separation method was investigated to separate U{sup 4+} and UO{sub 2}{sup 2+} without changing the redox species composition during the separation. First results of Pu speciation analysis showed that Pu could be eluted as three different species. Pu(VI) was always eluting at the same time as Np(V). This was surprising as Pu(VI) is expected to have the same chemical characteristics as U(VI) and thus was expected to elute at the same time as U(VI)

  7. Estimation of soil cation exchange capacity using Genetic Expression Programming (GEP) and Multivariate Adaptive Regression Splines (MARS)

    Science.gov (United States)

    Emamgolizadeh, S.; Bateni, S. M.; Shahsavani, D.; Ashrafi, T.; Ghorbani, H.

    2015-10-01

    The soil cation exchange capacity (CEC) is one of the main soil chemical properties, which is required in various fields such as environmental and agricultural engineering as well as soil science. In situ measurement of CEC is time consuming and costly. Hence, numerous studies have used traditional regression-based techniques to estimate CEC from more easily measurable soil parameters (e.g., soil texture, organic matter (OM), and pH). However, these models may not be able to adequately capture the complex and highly nonlinear relationship between CEC and its influential soil variables. In this study, Genetic Expression Programming (GEP) and Multivariate Adaptive Regression Splines (MARS) were employed to estimate CEC from more readily measurable soil physical and chemical variables (e.g., OM, clay, and pH) by developing functional relations. The GEP- and MARS-based functional relations were tested at two field sites in Iran. Results showed that GEP and MARS can provide reliable estimates of CEC. Also, it was found that the MARS model (with root-mean-square-error (RMSE) of 0.318 Cmol+ kg-1 and correlation coefficient (R2) of 0.864) generated slightly better results than the GEP model (with RMSE of 0.270 Cmol+ kg-1 and R2 of 0.807). The performance of GEP and MARS models was compared with two existing approaches, namely artificial neural network (ANN) and multiple linear regression (MLR). The comparison indicated that MARS and GEP outperformed the MLP model, but they did not perform as good as ANN. Finally, a sensitivity analysis was conducted to determine the most and the least influential variables affecting CEC. It was found that OM and pH have the most and least significant effect on CEC, respectively.

  8. Modification of polyamide-CdS-CdSe composite material films with Ag using a cation–cation exchange reaction

    International Nuclear Information System (INIS)

    Highlights: • We investigated deposition of a mixed CdSe-CdS-Ag2Se-Ag2S on polyamide. • A single chalcogen precursor – K2SeS2O6 – was used. • AAS showed five- to ten-fold excess of chalcogens diffused into PA. • Addition of AgNO3 resulted in subsurface Ag2Se–Ag2S formation. - Abstract: Thin mixed CdSe-CdS-Ag2Se-Ag2S films were deposited on a polyamide 6 (PA) surface by successfully using a cation-exchange reaction between Cd2+ and Ag+ to convert CdSe-CdS into Ag2Se-Ag2S. These were deposited using a K2SeS2O6 precursor solution at 60 °C followed by cadmium acetate (Cd(CH3COO)2). An aqueous AgNO3 solution was used as the Ag source. XRD patterns showed a complex PA-Cd-S-Se-Ag film crystalline composition with CdS, CdSe, Ag2S and Ag2Se peaks. Calculated dislocation density ranged within 5–15 × 1013 lines·m−2 indicating high quality atomic layers. Atomic Absorption Spectroscopy (AAS) showed five- to ten-fold excess of chalcogens to metals in the thin films formed. No chalcogenides were observed on the sample surface during XPS analysis after Ag exchange due to the desorption of CdS and CdSe layers, not diffused into the bulk of the polymer suggesting that silver chalcogenides were located subsurface, as opposed to the outermost layer, likely comprised of Ag2O

  9. Modification of polyamide-CdS-CdSe composite material films with Ag using a cation–cation exchange reaction

    Energy Technology Data Exchange (ETDEWEB)

    Krylova, V.; Žalenkienė, S.; Dukstienė, N. [Department of Physical and Inorganic Chemistry, Kaunas University of Technology, Radvilenu st. 19, LT-50254, Kaunas (Lithuania); Baltrusaitis, J., E-mail: job314@lehigh.edu [Department of Chemical and Biomolecular Engineering, Lehigh University, B336 Iacocca Hall, 111 Research Drive, Bethlehem, PA 18015 (United States)

    2015-10-01

    Highlights: • We investigated deposition of a mixed CdSe-CdS-Ag{sub 2}Se-Ag{sub 2}S on polyamide. • A single chalcogen precursor – K{sub 2}SeS{sub 2}O{sub 6} – was used. • AAS showed five- to ten-fold excess of chalcogens diffused into PA. • Addition of AgNO{sub 3} resulted in subsurface Ag{sub 2}Se–Ag{sub 2}S formation. - Abstract: Thin mixed CdSe-CdS-Ag{sub 2}Se-Ag{sub 2}S films were deposited on a polyamide 6 (PA) surface by successfully using a cation-exchange reaction between Cd{sup 2+} and Ag{sup +} to convert CdSe-CdS into Ag{sub 2}Se-Ag{sub 2}S. These were deposited using a K{sub 2}SeS{sub 2}O{sub 6} precursor solution at 60 °C followed by cadmium acetate (Cd(CH{sub 3}COO){sub 2}). An aqueous AgNO{sub 3} solution was used as the Ag source. XRD patterns showed a complex PA-Cd-S-Se-Ag film crystalline composition with CdS, CdSe, Ag{sub 2}S and Ag{sub 2}Se peaks. Calculated dislocation density ranged within 5–15 × 10{sup 13} lines·m{sup −2} indicating high quality atomic layers. Atomic Absorption Spectroscopy (AAS) showed five- to ten-fold excess of chalcogens to metals in the thin films formed. No chalcogenides were observed on the sample surface during XPS analysis after Ag exchange due to the desorption of CdS and CdSe layers, not diffused into the bulk of the polymer suggesting that silver chalcogenides were located subsurface, as opposed to the outermost layer, likely comprised of Ag{sub 2}O.

  10. Synthesis and characterization of a new inorganic cation-exchanger-Zr(IV) tungstomolybdate: Analytical applications for metal content determination in real sample and synthetic mixture

    International Nuclear Information System (INIS)

    An amorphous sample of inorganic cation-exchanger Zr(IV) tungstomolybdate was prepared by mixing varying ratios of 0.1 M aqueous solution of sodium tungstate and 0.1 M aqueous solution of sodium molybdate into 0.1 M aqueous solution of zirconium oxychloride at pH 1. This cation-exchanger was found to have a good ion-exchange capacity (2.40 mequiv. g-1 for Na+), high thermal and chemical stability. A tentative structural formula was proposed on the basis of chemical composition, FTIR and thermogravimetric analysis. Distribution coefficients (K d) values of metal ions in various solvent systems were determined. Some important and analytically difficult quantitative binary separations viz. Ni(II)-Pb(II), Ni(II)-Zn(II), Ni(II)-Cd(II), Mg(II)-Al(III), etc. were achieved. The practical applicability of the cation-exchanger was demonstrated in the separation of Cu(II)-Zn(II) from a synthetic mixture as well as from real samples of pharmaceutical formulation and brass alloy

  11. Suitability of the methylene blue test for determination of cation exchange capacity of clay minerals related to ammonium acetate method

    Science.gov (United States)

    Milošević, Maja; Logar, Mihovil; Dojčinović, Biljana; Erić, Suzana

    2015-04-01

    Cation exchange capacity (CEC) represents one of the most important parameters of clay minerals which reflects their ability to exchange cations with liquid phases in near contact. Measurement of CEC is used for characterizing sample plasticity, adsorbing and swelling properties which later define their usage in industrial purposes. Several methods have been developed over the years for determination of layer charge, charge density, charge distribution, etc. and have been published in numerous papers (Czimerova et al., 2006; Yukselen and Kaya, 2008). The main goal of present study is comparison of suitability of more recent method - methylene blue test in regard to older method - ammonium acetate for determination of CEC. For this study, we selected one montmorillonite clay (Bogovina, Serbia) and two mainly kaolinite clays (Miličinica, Serbia). Chemicals used for CEC determinations were solution of methylene blue (MB)(14*10-6M/ml) and ammonium acetate (AA) solution (1M). The obtained results are showing generally lower values in case of MB method. The main difference is due to molecular aggregation of MB on the clay surface. AA method is highly sensitive to the presence of CaO. Release of Ca ion from the sample into the solution can limit the saturation of exchange sites by the ammonium ion. This is clearly visible in case of montmorillonite clay. Fe2+ and Mg ions are difficult to move by the ammonium ion because of their ion radius, but in case of MB molecule there is no such restriction in removing them from the exchange sites. MB solution, even in a low concentration (2*10-6M/ml), is showing preferable results in moving the ions from their positions which is already visible after adding a small quantity of solution (25cm3). Both MB-titration and MB-spot test yield similar results and are much simpler methods than AA and they also give other information such as specific surface area (external and internal) whereas AA method only provides information about

  12. Ion chromatographic separation of inorganic ions using a combination of hydrophilic interaction chromatographic column and cation-exchange resin column

    Institute of Scientific and Technical Information of China (English)

    Kaori ARAI; Masanobu MORI; Takahiro HIRONAGA; Hideyuki ITABASHI; Kazuhiko TANAKA

    2012-01-01

    A combination of hydrophilic interaction chromatographic ( HILIC ) column and a weakly acidic cation-exchange resin (WCX) column was used for simultaneous separation of inorganic anions and cations by ion chromatography ( IC ).Firstly,the capability of HILIC column for the separation of analyte ions was evaluated under acidic eluent conditions.The columns used were SeQuant ZIC-HILIC (ZIC-HILIC) with a sulfobetainezwitterion stationary phase (ZIC-HILIC) and Acclaim HILIC-10 with a diol stationary phase (HILIC-10).When using tartaric acid as the eluent,the HILIC columns indicated strong retentions for anions,based on ion-pair interaction.Especially,HILIC-10 could strongly retain anions compared with ZIC-HILIC. The selectivity for analyte anions of HILIC-10 with 5 mmol/L tartaric acid eluent was in the order of I- > NO3- > Br- > Cl- >H2PO4-.However,since HILIC-10 could not separate analyte cations,a WCX column (TSKgel Super IC-A/C) was connected after the HILIC column in series.The combination column system of HILIC and WCX columns could successfully separate ten ions (Na+,NH4+,K+,Mg2+,Ca2+,H2PO4-,Cl-,Br-,NO3- and I-) with elution of 4 mmol/L tartaric acid plus 8 mmol/L 18-crown-6.The relative standard deviations (RSDs) of analyte ions by the system were in the ranges of 0.02% - 0.05% in retention times and 0.18% - 5.3% in peak areas through three-time successive injections.The limits of detection at signal-to-noise ratio of 3 were 0.24 - 0.30 μmol/L for the cations and 0.31 - 1.2 μmol/L for the anions.This system was applied for the simultaneous determination of the cations and the anions in a vegetable juice sample with satisfactory results.

  13. Anion- or Cation-Exchange Membranes for NaBH4/H2O2 Fuel Cells?

    Directory of Open Access Journals (Sweden)

    César A. C. Sequeira

    2012-07-01

    Full Text Available Direct borohydride fuel cells (DBFC, which operate on sodium borohydride (NaBH4 as the fuel, and hydrogen peroxide (H2O2 as the oxidant, are receiving increasing attention. This is due to their promising use as power sources for space and underwater applications, where air is not available and gas storage poses obvious problems. One key factor to improve the performance of DBFCs concerns the type of separator used. Both anion- and cation-exchange membranes may be considered as potential separators for DBFC. In the present paper, the effect of the membrane type on the performance of laboratory NaBH4/H2O2 fuel cells using Pt electrodes is studied at room temperature. Two commercial ion-exchange membranes from Membranes International Inc., an anion-exchange membrane (AMI-7001S and a cation-exchange membrane (CMI-7000S, are tested as ionic separators for the DBFC. The membranes are compared directly by the observation and analysis of the corresponding DBFC’s performance. Cell polarization, power density, stability, and durability tests are used in the membranes’ evaluation. Energy densities and specific capacities are estimated. Most tests conducted, clearly indicate a superior performance of the cation-exchange membranes over the anion-exchange membrane. The two membranes are also compared with several other previously tested commercial membranes. For long term cell operation, these membranes seem to outperform the stability of the benchmark Nafion membranes but further studies are still required to improve their instantaneous power load.

  14. Liquid-liquid extraction and separation of VIII group elements, especially ruthenium, by synergic combinations or aromatic polyimines and micellar cationic exchangers

    International Nuclear Information System (INIS)

    This thesis aims to characterize and to quantify the chemical equilibria involved in d-elements liquid-liquid extraction systems, especially elements belonging to the VIII group (Fe, Ni, Co, Ru, Rh, Pd, Pt). These systems are composed of synergic combination of aromatic polyimines and micellar cationic exchangers. Substitutions are first performed in aqueous acidic media by aromatic polyimines; then extractions are operated using micellic canionic exchangers. Chemical equilibria, selectivity effects, especially those due to ion-pair formations, kinetics, extractant behaviour are analysed and quantified

  15. Ionic liquid synergistic cation-exchange system for the selective extraction of lanthanum(III) using 2-thenoyltrifluoroacetone and 18-crown-6.

    Science.gov (United States)

    Hirayama, Naoki; Okamura, Hiroyuki; Kidani, Keiji; Imura, Hisanori

    2008-06-01

    A novel synergistic extraction system was investigated for the possible selective separation of light lanthanoids using an ionic liquid, 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, as an extraction solvent and 2-thenoyltrifluoroacetone and 18-crown-6 as extractants. Trivalent lanthanum was efficiently extracted as a cationic ternary complex by the cation-exchange process, whereas europium and lutetium showed relatively low extractability without forming respective ternary complexes. This result is thought to originate in a size-fitting effect of 18-crown-6 to lanthanum and the unique nature of the ionic liquid as a chelate extraction solvent. PMID:18544855

  16. Thermodynamics of the extraction of scandium(III) by the liquid cation exchangers dinonylnaphthalenesulfonic acid and bis(2-ethylhexyl) phosphoric acid

    International Nuclear Information System (INIS)

    The thermodynamic functions for the extraction of Sc3+ by liquid cation exchangers HD and HDEHP are determined radiometrically by the temperature coefficient method. The role of the diluent dielectric constant on the extraction of Sc3+ by HD is also studied. The thermodynamic parameters determined indicated that the free energy variation for the extraction of Sc3+ by HD is mainly determined by the entropic terms arising from the hydration-dehydration process of the exchanged ions. In the case of HDEHP as extractant, the free energy variations are determined mainly by the entalpic terms of the system. (author)

  17. Studies on the removal of trace amounts of 137Cs and 90Sr from low level effluents using PSS type cation exchanger

    International Nuclear Information System (INIS)

    Usability of commercial polystyrene sulphonate cation exchanger, for the removal of trace concentrations of 137Cs and 90Sr from low level effluent stream generated from nuclear installations is studied. Batch sorption experiments are carried out under different experimental conditions from 137Cs and 90Sr spiked aqueous solutions of varied pH to evaluate and establish suitable operating parameters for the removal of the two most potentially mobile radionuclides. Results show that the resin can be used for the sorption of these radionuclide from spent fuel pond as well as from waste streams containing low concentrations of salt. (author)

  18. A cation exchange method for separation of 111In from inactive silver, copper, traces of iron and radioactive gallium and zinc isotopes

    International Nuclear Information System (INIS)

    111In was produced by the 109Ag(α, 2n)111In reaction. A simple radiochemical separation technique, using Dowex-50 cation exchange resin (with prior removal of copper bulk, if present), has been employed to separate radioindium from inactive contaminants like Ag, Cu, Fe and active contaminant like 67Ga and 65Zn. The radiochemical separation yield was 90-99%. The radionuclide purity of 111In was >99% at 60 h after EOB. The level of all the inactive contaminants was <5 μg/mL in the final product. (Author)

  19. Fabrication, characterization and photocatalytic properties of Ag/AgI/BiOI heteronanostructures supported on rectorite via a cation-exchange method

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yunfang [School of Chemistry and Environment, South China Normal University, Guangzhou 510006, Guangdong (China); Fang, Jianzhang, E-mail: fangjzh@scnu.edu.cn [School of Chemistry and Environment, South China Normal University, Guangzhou 510006, Guangdong (China); Guangdong Technology Research Center for Ecological Management and Remediation of Urban Water System, Guangzhou 510006 (China); Lu, Shaoyou [Shenzhen Center for Disease Control and Prevention, Shenzhen 518055 (China); Wu, Yan; Chen, Dazhi; Huang, Liyan [Institute of Engineering Technology of Guangdong Province, Key Laboratory of Water Environmental Pollution Control of Guangdong Province, Guangzhou 510440 (China); Xu, Weicheng; Zhu, Ximiao [School of Chemistry and Environment, South China Normal University, Guangzhou 510006, Guangdong (China); Fang, Zhanqiang [School of Chemistry and Environment, South China Normal University, Guangzhou 510006, Guangdong (China); Guangdong Technology Research Center for Ecological Management and Remediation of Urban Water System, Guangzhou 510006 (China)

    2015-04-15

    Highlights: • Ag/AgI/BiOI-rectorite was prepared by twice cation-exchange process. • Ag/AgI/BiOI-rectorite photocatalyst possessed SPR and adsorption capacity. • Ag/AgI/BiOI-rectorite exhibited highly photocatalytic activity. • Trapped holes and ·O{sub 2}{sup −} were formed active species in the photocatalytic system. - Abstract: In this work, a new plasmonic photocatalyst Ag/AgI/BiOI-rectorite was prepared via a cation exchange process. The photocatalyst had been characterized by X-ray powder diffraction (XRD), Raman spectra, nitrogen sorption (BET), field-emission scanning electron microscope (FE-SEM), X-ray photoelectron spectroscopy (XPS) and UV–vis diffuse reflectance spectroscopy (DRS). The photocatalytic activity, which was evaluated by degradation of rhodamine B (RhB) and bisphenol A (BPA) under visible light irradiation, was enhanced significantly by loading Ag/AgI/BiOI nanoparticles onto rectorite. The photogenerated holes and superoxide radical (·O{sub 2}{sup −}) were both formed as active species for the photocatalytic reactions under visible light irradiation. The existence of metallic Ag particles, which possess the surface plasmon resonance effect, acted as an indispensable role in the photocatalytic reaction.

  20. Determination of some aliphatic carboxylic acids in anaerobic digestion process waters by ion-exclusion chromatography with conductimetric detection on a weakly acidic cation-exchange resin column.

    Science.gov (United States)

    Ito, Kazuaki; Takayama, Yohichi; Ikedo, Mikaru; Mori, Masanobu; Taoda, Hiroshi; Xu, Qun; Hu, Wenzhi; Sunahara, Hiroshi; Hayashi, Tsuneo; Sato, Shinji; Hirokawa, Takeshi; Tanaka, Kazuhiko

    2004-06-11

    The determination of seven aliphatic carboxylic acids, formic, acetic, propionic, isobutyric, n-butyric, isovaleric and n-valeric acids in anaerobic digestion process waters was examined using ion-exclusion chromatography with conductimetric detection. The analysis of these biologically important carboxylic acids is necessary as a measure for evaluating and controlling the process. The ion-exclusion chromatography system employed consisted of polymethacrylate-based weakly acidic cation-exchange resin columns (TSKgel OApak-A or TSKgel Super IC-A/C). weakly acidic eluent (benzoic acid), and conductimetric detection. Particle size and cation-exchange capacity were 5 microm and 0.1 meq./ml for TSKgel OApak-A and 3 microm and 0.2 meq./ml for TSKgel Super IC-A/C, respectively. A dilute eluent (1.0-2.0 mM) of benzoic acid was effective for the high resolution and highly conductimetric detection of the carboxylic acids. The good separation of isobutyric and n-butyric acids was performed using the TSKgel Super IC-A/C column (150 mm x 6.0 mm i.d. x 2). The simple and good chromatograms were obtained by the optimized ion-exclusion chromatography conditions for real samples from mesophilic anaerobic digestors, thus the aliphatic carboxylic acids were successfully determined without any interferences. PMID:15250416

  1. Ion-exclusion chromatography with conductimetric detection of aliphatic carboxylic acids on a weakly acidic cation-exchange resin by elution with benzoic acid-beta-cyclodextrin.

    Science.gov (United States)

    Tanaka, Kazuhiko; Mori, Masanobu; Xu, Qun; Helaleh, Murad I H; Ikedo, Mikaru; Taoda, Hiroshi; Hu, Wenzhi; Hasebe, Kiyoshi; Fritz, James S; Haddad, Paul R

    2003-05-16

    In this study, an aqueous solution consisting of benzoic acid with low background conductivity and beta-cyclodextrin (beta-CD) of hydrophilic nature and the inclusion effect to benzoic acid were used as eluent for the ion-exclusion chromatographic separation of aliphatic carboxylic acids with different pKa values and hydrophobicity on a polymethacrylate-based weakly acidic cation-exchange resin in the H+ form. With increasing concentration of beta-cyclodextrin in the eluent, the retention times of the carboxylic acids decreased due to the increased hydrophilicity of the polymethacrylate-based cation-exchange resin surface from the adsorption of OH groups of beta-cyclodextrin. Moreover, the eluent background conductivity decreased with increasing concentration of beta-cyclodextrin in 1 mM benzoic acid, which could result in higher sensitivity for conductimetric detection. The ion-exclusion chromatographic separation of carboxylic acids with high resolution and sensitivity was accomplished successfully by elution with a 1 mM benzoic acid-10 mM cyclodextrin solution without chemical suppression. PMID:12830884

  2. Superconductivity of 132 K in HgBa2Ca2Cu3O8+δ thin films fabricated using a cation exchange method

    International Nuclear Information System (INIS)

    A cation exchange method was applied to convert epitaxial TlBa2Ca2Cu3O8 (Tl-1223) and Tl2Ba2Ca2Cu3O10 (Tl-2223) precursor superconducting thin films to epitaxial HgBa2Ca2Cu3O8+δ (Hg-1223) films on LaAlO3 (001) substrates. While the conversion of Tl-1223 to Hg-1223 was partially successful, high-quality epitaxial Hg-1223 films were obtained from Tl-2223 precursor films. A critical transition temperature Tc of up to 132 K has been demonstrated for the Hg-1223 films, which is close to the optimal value of 135 K reported on Hg-1223 bulk samples. The critical current density Jc of the Hg-1223 films was up to 0.25 MA cm−2 at 77 K and self-field. This work represents the first success in achieving the highest-Tc epitaxial Hg-1223 films using the cation exchange method, which are promising candidates for device applications with operational temperatures significantly above the temperature of liquid nitrogen. (paper)

  3. Modeling the competition between solid solution formation and cation exchange on the retardation of aqueous radium in an idealized bentonite column

    International Nuclear Information System (INIS)

    Clays and clay rocks are considered viable geotechnical barriers in radioactive waste disposal. One reason for this is the propensity for cation exchange reactions in clay minerals to retard the migration of radionuclides. Although another retardation mechanism, namely the incorporation of radionuclides into sulfate or carbonate solid solutions, has been known for a long time, only recently has it been examined systematically. In this work, we investigate the competitive effect of both mechanisms on the transport of radium (Ra) in the near-field of a low- and intermediate level nuclear waste repository. In our idealized geochemical model, numerical simulations show that barium (Ba) and strontium (Sr) needed for Ra sulfate solid solutions also partition to the cation exchange sites of montmorillonite (Mont), which is the major mineral constituent of bentonite that is used for tunnel backfill. At high Mont content, most Ra tends to attach to Mont, while incorporation of Ra in sulfate solid solutions is more important at low Monte content. To explore the effect of the Mont content on the transport of radium, a multi-component reactive transport model was developed and implemented in the scientific software OpenGeoSys-GEM. It was found that a decrease of fixation capacity due to low Mont content is compensated by the formation of solid solutions and that the migration distance of aqueous Ra is similar at different Mont/water ratios. (author)

  4. Obtention of the cation exchange capacity of a natural kaolinite with radioactive tracers; Obtencion de la capacidad de intercambio cationico de una kaolinita natural con trazadores radioactivos

    Energy Technology Data Exchange (ETDEWEB)

    Uribe I, A.; Badillo A, V.E. [Universidad Autonoma de Zacatecas, 98000 Zacatecas (Mexico); Monroy G, F. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)]. e-mail: Adrya81@hotmail.com

    2005-07-01

    One of the more used techniques for the elimination of the heavy metals present in water systems is to use adsorbent mineral phases like zeolites and clays, among others. The clays are able to exchange easily the fixed ions in the external surface of its crystals or well the ions present in the interlaminar spaces of the structures, for other existent ones in the encircling aqueous solutions for that the Cation exchange capacity (CIC) is defined as the sum of all the cations exchange that a mineral can possess independent to the physicochemical conditions. The CIC is equal to the measure of the total of negative charges of the mineral by mass of the solid (meq/g). In this investigation work, the value of the CIC equal to 2.5 meq/100 g is obtained, of a natural kaolinite from the State of Hidalgo studying the retention of the sodium in the kaolinite with the aid of the radioactive isotope {sup 24} Na and of the selective electrodes technique, making vary the pH value. So is experimentally demonstrated that the CIC is an intrinsic property of the mineral independent of the pH value of the solution and of the charges origin. (Author)

  5. Cation Exchange Combined with Kirkendall Effect in the Preparation of SnTe/CdTe and CdTe/SnTe Core/Shell Nanocrystals.

    Science.gov (United States)

    Jang, Youngjin; Yanover, Diana; Čapek, Richard Karel; Shapiro, Arthur; Grumbach, Nathan; Kauffmann, Yaron; Sashchiuk, Aldona; Lifshitz, Efrat

    2016-07-01

    Controlling the synthesis of narrow band gap semiconductor nanocrystals (NCs) with a high-quality surface is of prime importance for scientific and technological interests. This Letter presents facile solution-phase syntheses of SnTe NCs and their corresponding core/shell heterostructures. Here, we synthesized monodisperse and highly crystalline SnTe NCs by employing an inexpensive, nontoxic precursor, SnCl2, the reactivity of which was enhanced by adding a reducing agent, 1,2-hexadecanediol. Moreover, we developed a synthesis procedure for the formation of SnTe-based core/shell NCs by combining the cation exchange and the Kirkendall effect. The cation exchange of Sn(2+) by Cd(2+) at the surface allowed primarily the formation of SnTe/CdTe core/shell NCs. Further continuation of the reaction promoted an intensive diffusion of the Cd(2+) ions, which via the Kirkendall effect led to the formation of the inverted CdTe/SnTe core/shell NCs. PMID:27331900

  6. Fabrication, characterization and photocatalytic properties of Ag/AgI/BiOI heteronanostructures supported on rectorite via a cation-exchange method

    International Nuclear Information System (INIS)

    Highlights: • Ag/AgI/BiOI-rectorite was prepared by twice cation-exchange process. • Ag/AgI/BiOI-rectorite photocatalyst possessed SPR and adsorption capacity. • Ag/AgI/BiOI-rectorite exhibited highly photocatalytic activity. • Trapped holes and ·O2− were formed active species in the photocatalytic system. - Abstract: In this work, a new plasmonic photocatalyst Ag/AgI/BiOI-rectorite was prepared via a cation exchange process. The photocatalyst had been characterized by X-ray powder diffraction (XRD), Raman spectra, nitrogen sorption (BET), field-emission scanning electron microscope (FE-SEM), X-ray photoelectron spectroscopy (XPS) and UV–vis diffuse reflectance spectroscopy (DRS). The photocatalytic activity, which was evaluated by degradation of rhodamine B (RhB) and bisphenol A (BPA) under visible light irradiation, was enhanced significantly by loading Ag/AgI/BiOI nanoparticles onto rectorite. The photogenerated holes and superoxide radical (·O2−) were both formed as active species for the photocatalytic reactions under visible light irradiation. The existence of metallic Ag particles, which possess the surface plasmon resonance effect, acted as an indispensable role in the photocatalytic reaction

  7. Brine Distribution after Vacuum Saturation

    DEFF Research Database (Denmark)

    Hedegaard, Kathrine; Andersen, Bertel Lohmann

    1999-01-01

    Experiments with the vacuum saturation method for brine in plugs of chalk showed that a homogeneous distribution of brine cannot be ensured at saturations below 20% volume. Instead of a homogeneous volume distribution the brine becomes concentrated close to the surfaces of the plugs......Experiments with the vacuum saturation method for brine in plugs of chalk showed that a homogeneous distribution of brine cannot be ensured at saturations below 20% volume. Instead of a homogeneous volume distribution the brine becomes concentrated close to the surfaces of the plugs...

  8. Silica in alkaline brines

    Science.gov (United States)

    Jones, B.F.; Rettig, S.L.; Eugster, H.P.

    1967-01-01

    Analysis of sodium carbonate-bicarbonate brines from closed basins in volcanic terranes of Oregon and Kenya reveals silica contents of up to 2700 parts per million at pH's higher than 10. These high concentrations of SiO 2 can be attributed to reaction of waters with silicates, and subsequent evaporative concentration accompanied by a rise in pH. Supersaturation with respect to amorphous silica may occur and persist for brines that are out of contact with silicate muds and undersaturated with respect to trona; correlation of SiO2 with concentration of Na and total CO2 support this interpretation. Addition of moredilute waters to alkaline brines may lower the pH and cause inorganic precipitation of substantial amounts of silica.

  9. Cation exchanged Fe(II) and Sr compared to other divalent cations (Ca, Mg) in the bure Callovian-Oxfordian formation: Implications for porewater composition modelling

    International Nuclear Information System (INIS)

    Iron and Sr bearing phases were thoroughly investigated by means of spectrometric and microscopic techniques in Callovian-Oxfordian (COX) samples originating from the ANDRA Underground Research Laboratory (URL) in Bure (France). Strontium was found to be essentially associated with celestite, whereas Fe was found to be distributed over a wide range of mineral phases. Iron was mainly present as Fe(II) in the studied samples (∼93% from Moessbauer results). Most of the Fe(II) was found to be in pyrite, sideroplesite/ankerite and clay minerals. Iron(III), if present, was associated with clay minerals (probably illite, illite-smectite mixed layer minerals and chlorite). No Fe(III) oxy(hydro)xide could be detected in the samples. Strontianite was not observed either. Based on these observations, it is likely that the COX porewater is in equilibrium with the following carbonate minerals, calcite, dolomite and ankerite/sideroplesite, but not with strontianite. It is shown that this equilibrium information can be combined with clay cation exchange composition information in order to give direct estimates or constraints on the solubility products of the carbonate minerals dolomite, siderite and strontianite. As a consequence, an experimental method was developed to retrieve the cation exchanged Fe(II) in very well preserved COX samples. The very homogeneous cation exchange composition of the formation is completely in agreement with a homogeneous presence of calcite and dolomite minerals whose equilibrium reactions control part of the porewater composition. Amongst the broad range of values available for dolomite solubility products in thermodynamic databases, the value of log Kdolomite = -3.57 is the most appropriate for the one present in the COX formation. With regard to strontianite, it appears that the equilibrium constant tabulated in the Llnl database is not valid for natural clay systems. The value given by Busenberg et al. used by most of the other available

  10. A study on equilibrium and kinetics of ion exchange of alkaline earth metals using an inorganic cation exchanger - zirconium titanium phosphate

    Indian Academy of Sciences (India)

    Amin Jignasa; Thakkar Rakesh; Chudasama Uma

    2006-03-01

    An advanced inorganic cation exchange material of the class of tetravalent metal acid (TMA) salt, zirconium titanium phosphate (ZTP), has been synthesized by a modified sol-gel technique. ZTP has been characterized by elemental analysis (ICP-AES), thermal analysis (TGA), FTIR and X-ray diffraction studies. The Nernst-Planck equation has been used to study the forward and reverse ion exchange kinetics of Mg (II), Ca (II), Sr (II) and Ba (II) with H (I) at four different temperatures. The mechanism of exchange is particle diffusion, as confirmed by the linear (dimensionless time parameter) vs (time) plots. The exchange process is thus controlled by the diffusion within the exchanger particles for the systems studied herein. Further, various kinetic parameters like self-diffusion coefficient (0), energy of activation () and entropy of activation (*) have been evaluated under conditions favouring a particle diffusion-controlled mechanism.

  11. Synthesis and characterization of a novel hybrid nano composite cation exchanger poly-o-toluidine Sn(IV) tungstate: Its analytical applications as ion-selective electrode

    Science.gov (United States)

    Khan, Asif Ali; Shaheen, Shakeeba

    2013-02-01

    A novel organic-inorganic nano composite cation exchanger poly-o-toluidine Sn(IV) tungstate has been synthesized by incorporation of a polymer material into inorganic precipitate. The material is a class of hybrid ion-exchanger with good ion-exchange properties, reproducibility, stability and good selectivity for heavy metals. The physico-chemical properties of this nano composite material were characterized by using XRD, TGA, FTIR, SEM and TEM. The ion-exchange capacity, pH titrations, elution behavior and chemical stability were also carried out to study ion-exchange properties of the material. Distribution studies for various metal ions revealed that the nano composite is highly selective for Cd(II). An ion-selective membrane electrode was fabricated using this material for the determination of Cd(II) ions in solutions. The analytical utility of this electrode was established by employing it as an indicator electrode in electrometric titrations.

  12. Cation exchange synthesis of uniform PbSe/PbS core/shell tetra-pods and their use as near-infrared photodetectors

    Science.gov (United States)

    Mishra, N.; Mukherjee, B.; Xing, G.; Chakrabortty, S.; Guchhait, A.; Lim, J. Y.

    2016-07-01

    In this work we explore the preparation of complex-shaped semiconductor nanostructures composed of different materials via a cationic exchange process in which the cations of the original semiconductor nanostructure are replaced by cations of different metals with preservation of the shape and the anionic framework of the nanocrystals. Utilizing this cation exchange method, we synthesized two new tetrapods for the first time: Cu2-xSe/Cu2-xS and PbSe/PbS, both prepared from CdSe/CdS tetrapods as `templates'. We also fabricated near-infrared (NIR) photodetectors with a very simple architecture comprising a PbSe/PbS tetrapod layer between two Au electrodes on a glass substrate. When illuminated by a NIR laser, these devices are capable of achieving a responsivity of 11.9 A W-1 without the use of ligand-exchange processes, thermal annealing or hybrid device architecture. Transient absorption spectroscopy was carried out on these PbSe/PbS tetrapods, the results of which suggest that the branched morphology contributes in part to device performance. Investigation of the charge dynamics of the PbSe/PbS tetrapods revealed an extremely long-lived exciton recombination lifetime of ~17 ms, which can result in enhanced photoconductive gain. Overall, these heterostructured tetrapods showcase simultaneously the importance of nanoparticle shape, band structure, and surface chemistry in the attainment of NIR photodetection.In this work we explore the preparation of complex-shaped semiconductor nanostructures composed of different materials via a cationic exchange process in which the cations of the original semiconductor nanostructure are replaced by cations of different metals with preservation of the shape and the anionic framework of the nanocrystals. Utilizing this cation exchange method, we synthesized two new tetrapods for the first time: Cu2-xSe/Cu2-xS and PbSe/PbS, both prepared from CdSe/CdS tetrapods as `templates'. We also fabricated near-infrared (NIR) photodetectors

  13. Effect of bore fluid composition on microstructure and performance of a microporous hollow fibre membrane as a cation-exchange substrate.

    Science.gov (United States)

    Lazar, R A; Mandal, I; Slater, N K H

    2015-05-15

    Micro-capillary film (MCF) membranes are effective platforms for bioseparations and viable alternatives to established packed bed and membrane substrates at the analytical and preparative chromatography scales. Single hollow fibre (HF) MCF membranes with varied microstructures were produced in order to evaluate the effect of the bore fluid composition used during hollow fibre extrusion on their structure and performance as cation-exchange adsorbers. Hollow fibres were fabricated from ethylene-vinyl alcohol (EVOH) copolymer through solution extrusion followed by nonsolvent induced phase separation (NIPS) using bore fluids of differing composition (100wt.% N-methyl-2-pyrrolidone (NMP), 100wt.% glycerol, 100wt.% water). All HFs displayed highly microporous and mesoporous microstructures, with distinct regions of pore size membrane performance as a result of inner surface porosity was established with a view to applying this parameter for the optimisation of multi-capillary MCF performance in future studies. PMID:25840664

  14. Investigating Brine Shrimp.

    Science.gov (United States)

    Duran, Lena Ballone

    2003-01-01

    Presents a brine shrimp activity designed for students in grades 5-12 to foster authentic scientific inquiry in addition to providing an engaging and exciting avenue for student exploration. Emphasizes that inquiry should be a critical component in the science classroom. (KHR)

  15. On the real performance of cation exchange resins in wastewater treatment under conditions of cation competition: the case of heavy metal pollution.

    Science.gov (United States)

    Prelot, Benedicte; Ayed, Imen; Marchandeau, Franck; Zajac, Jerzy

    2014-01-01

    Sorption performance of cation-exchange resins Amberlite® IRN77 and Amberlite™ IRN9652 toward Cs(I) and Sr(II) has been tested in single-component aqueous solutions and simulated waste effluents containing other monovalent (Effluent 1) or divalent (Effluent 2) metal cations, as well as nitrate, borate, or carbonate anions. The individual sorption isotherms of each main component were measured by the solution depletion method. The differential molar enthalpy changes accompanying the ion-exchange between Cs+ or Sr2+ ions and protons at the resin surface from single-component nitrate solutions were measured by isothermal titration calorimetry and they showed a higher specificity of the two resins toward cesium. Compared to the retention limits of both resins under such idealized conditions, an important depression in the maximum adsorption capacity toward each main component was observed in multication systems. The overall effect of ion exchange process appeared to be an unpredictable outcome of the individual sorption capacities of the two resins toward various cations as a function of the cation charge, size, and concentration. The cesium retention capacity of the resins was diminished to about 25% of the "ideal" value in Effluent 1 and 50% in Effluent 2; a further decrease to about 15% was observed upon concomitant strontium addition. The uptake of strontium by the resins was found to be less sensitive to the addition of other metal components: the greatest decrease in the amount adsorbed was 60% of the ideal value in the two effluents for Amberlite® IRN77 and 75% for Amberlite™ IRN9652. It was therefore demonstrated that any performance tests carried out under idealized conditions should be exploited with much caution to predict the real performance of cation exchange resins under conditions of cation competition. PMID:24728575

  16. Synthesis of Capsule-like Porous Hollow Nanonickel Cobalt Sulfides via Cation Exchange Based on the Kirkendall Effect for High-Performance Supercapacitors.

    Science.gov (United States)

    Tang, Yongfu; Chen, Shunji; Mu, Shichun; Chen, Teng; Qiao, Yuqing; Yu, Shengxue; Gao, Faming

    2016-04-20

    To construct a suitable three-dimensional structure for ionic transport on the surface of the active materials for a supercapacitor, porous hollow nickel cobalt sulfides are successfully synthesized via a facile and efficient cation-exchange reaction in a hydrothermal process involving the Kirkendall effect with γ-MnS nanorods as a sacrificial template. The formation mechanism of the hollow nickel cobalt sulfides is carefully illustrated via the tuning reaction time and reaction temperature during the cation-exchange process. Due to the ingenious porous hollow structure that offers a high surface area for electrochemical reaction and suitable paths for ionic transport, porous hollow nickel cobalt sulfide electrodes exhibit high electrochemical performance. The Ni1.77Co1.23S4 electrode delivers a high specific capacity of 224.5 mAh g(-1) at a current density of 0.25 A g(-1) and a high capacity retention of 87.0% at 10 A g(-1). An all-solid-state asymmetric supercapacitor, assembled with a Ni1.77Co1.23S4 electrode as the positive electrode and a homemade activated carbon electrode as the negative electrode (denoted as NCS//HMC), exhibits a high energy density of 42.7 Wh kg(-1) at a power density of 190.8 W kg(-1) and even 29.4 Wh kg(-1) at 3.6 kW kg(-1). The fully charged as-prepared asymmetric supercapacitor can light up a light emitting diode (LED) indicator for more than 1 h, indicating promising practical applications of the hollow nickel cobalt sulfides and the NCS//HMC asymmetric supercapacitor. PMID:27031254

  17. Extraction of lithium from salt lake brine using room temperature ionic liquid in tributyl phosphate

    International Nuclear Information System (INIS)

    Highlights: • We proposed a new system for Li recovery from salt lake brine by extraction using an ionic liquid. • Cation exchange was proposed to be the mechanism of extraction followed in ionic liquid. • This ionic liquid system shown considerable extraction ability for lithium and the single extraction efficiency of lithium reached 87.28% under the optimal conditions. - Abstract: Lithium is known as the energy metal and it is a key raw material for preparing lithium isotopes which have important applications in nuclear energy source. In this work, a typical room temperature ionic liquid (RTILs), 1-butyl-3-methyl-imidazolium hexafluorophosphate ([C4mim][PF6]), was used as an alternative solvent to study liquid/liquid extraction of lithium from salt lake brine. In this system, the ionic liquid, NaClO4 and tributyl phosphate (TBP) were used as extraction medium, co-extraction reagent and extractant respectively. The effects of solution pH value, phase ratio, ClO4− amount and other factors on lithium extraction efficiency had been investigated. Optimal extraction conditions of this system include the ratio of TBP/IL at 4/1 (v/v), O/A at 2:1, n(ClO4−)/n(Li+) at 2:1, the equilibration time of 10 min and unadjusted pH. Under the optimal conditions, the single extraction efficiency of lithium was 87.28% which was much higher than the conventional extraction system. Total extraction efficiency of 99.12% was obtained by triple-stage countercurrent extraction. Study on the mechanism revealed that the use of ionic liquid increased the extraction yield of lithium through cation exchange in this system. Preliminary results indicated that the use of [C4mim][PF6] as an alternate solvent to replace traditional organic solvents (VOCs) in liquid/liquid extraction was very promising

  18. Soil washing for brine removal

    International Nuclear Information System (INIS)

    During the exploration for oil and thereafter, brine transfer lines get ruptured releasing the brine which contaminates the surrounding soil. The salinity level in brine is very high, sometimes approaching or exceeding that of sea water. Soils contaminated with brine are unproductive and unsuitable for plant growth. Several investigators have documented the pollution of surface water and groundwater due to brine disposal from oil and needed to clean up such sites. The objective of this study is to develop a soil washing technique that can be used to remove brine sites were collected and used in the study. This paper reports on results which indicate that soil washing using various surface active agents is effective in removing the brine

  19. Use of Cation Exchange Resins for Production of U{sub 3}O{sub 8} Suitable for the Al-U{sub 3}O{sub 8} Powder Metallurgy Process

    Energy Technology Data Exchange (ETDEWEB)

    Mosley, W.C.

    2001-09-17

    This report describes the production of U{sub 3}O{sub 8} powders from three types of cation exchange resins: Dowex 50W, a strong acid, sulfonate resin; AG MP-50, a macroporous form of sulfonate resin; and Bio-Rex 70, a weak acid, carboxylic resin.

  20. Brine Sampling and Evaluation Program

    International Nuclear Information System (INIS)

    The Brine Sampling and Evaluation Program (BSEP) Phase II Report is an interim report which updates the data released in the BSEP Phase I Report. Direct measurements and observations of the brine that seeps into the WIPP repository excavations were continued through the period between August 1986 and July 1987. That data is included in Appendix A, which extends the observation period for some locations to approximately 900 days. Brine observations at 87 locations are presented in this report. Although WIPP underground workings are considered ''dry,'' small amounts of brine are present. Part of that brine migrates into the repository in response to pressure gradients at essentially isothermal conditions. The data presented in this report is a continuation of moisture content studies of the WIPP facility horizon that were initiated in 1982, as soon as underground drifts began to be excavated. Brine seepages are manifested by salt efflorescences, moist areas, and fluid accumulations in drillholes. 35 refs., 6 figs., 11 tabs

  1. Lanthanide N,N'-piperazine-bis(methylenephosphonates) (Ln=La, Ce, Nd) that display flexible frameworks, reversible hydration and cation exchange

    International Nuclear Information System (INIS)

    Hydrothermal syntheses of lanthanide bisphosphonate metal organic frameworks comprising the light lanthanides lanthanum, cerium and neodymium and N,N'-piperazine bis(methylenephosphonic acid) (H2L(1) and its 2-methyl and 2,5-dimethyl derivatives (H2L(2) and H2L(3)) gives three new structure types. At elevated starting pH (ca. 5 and above) syntheses give 'type I' materials with all metals and acids of the study (MLnLxH2O, M=Na, K, Cs; Ln=La, Ce, Nd; x∼4: KCeL(1).4H2O, C2/c, a=23.5864(2) A, b=12.1186(2) A, c=5.6613(2) A, β=93.040(2)o). The framework of structure type I shows considerable flexibility as the ligand is changed, due mainly to rotation around the -N-CH2- bond of the linker in response to steric considerations. Type I materials demonstrate cation exchange and dehydration and rehydration behaviour. Upon dehydration of KCeL.4H2O, the space group changes to P21/n, a=21.8361(12) A, b=9.3519(4) A, c=5.5629(3) A, β=96.560(4)o, as a result of a change of the piperazine ring from chair to boat configuration. When syntheses are performed at lower pH, two other structure types crystallise. With the 'non-methyl' ligand 1, type II materials result (LnL(1)H2L(1).4.5H2O: Ln=La, P-1, a=5.7630(13) A, b=10.213(2) A, c=11.649(2) A, α=84.242(2)o, β=89.051(2)o, γ=82.876(2)o) in which one half of the ligands coordinate via the piperazine nitrogen atoms. With the 2-methyl ligand, structure type III crystallises (LnHL(2).4H2O: Ln=Nd, Ce, P21/c, a=5.7540(9) A, b=14.1259(18) A, c=21.156(5) A, β=90.14(2)o) due to unfavourable steric interactions of the methyl group in structure type II. - Graphical abstract: The lanthanides La, Ce and Nd give a family of metal organic frameworks based on N,N'-piperazinebismethylenephosphonate ligands: these display reversible dehydration, structural flexibility and cation exchange.

  2. Electrochemical regeneration of spent ion exchange resin

    International Nuclear Information System (INIS)

    CAN-DECON™, CAN-DEREM™ and CAN-DEREM Plus™ processes developed by Atomic Energy of Canada Limited (AECL) are dilute regenerative chemical decontamination processes that employ ion exchange resin to remove dissolved metals and radionuclides and to regenerate the reagents. Depending on the system volume and oxide and radionuclide inventories, a large volume of spent ion exchange resin may be generated. Storage and long term disposal of spent resin may be one of the impediments to routine use of chemical decontamination processes. An electrochemical method is being developed by AECL for the regeneration of spent ion exchange resin generated during application of CAN-DECON, CAN-DEREM and CAN-DEREM Plus processes. In addition, some of the work being carried out is directed at methods for liquid waste treatment. This paper will describe the three-compartment electrochemical cell developed for laboratory tests. The cell consists of an anode, cathode and central compartment, the latter containing either solid spent resin or spent solution. The anode and the cathode compartments are separated from the central section by cation exchange membranes which allow cations to transport from anode to cathode compartments through the membranes. The paper will discuss the results of cyclic voltammetry tests performed in CAN-DEREM reagents to determine the iron redox potential in these electrolytes. The results of iron deposition tests performed in simulated spent CAN-DEREM reagents to study the current efficiency of iron deposition as a function of iron concentration, pH, cathode material and temperature will be presented. The results of tests of several commercial cation exchange membranes to study transport efficiency of iron through these membranes will also be discussed. (author)

  3. A comparative study on textural characterization: cation-exchange and sorption properties of crystalline alpha-zirconium(IV), tin(IV), and titanium(IV) phosphates.

    Science.gov (United States)

    Parida, K M; Sahu, B B; Das, D P

    2004-02-15

    Tetravalent metal phosphates (M=Zr, Ti, and Sn) were prepared and characterized by XRD, surface properties, and TG-DTA. The cation exchange and sorption behavior of these metal phosphates toward transition metal ions such as Cu(2+), Co(2+), and Ni(2+) have been studied comparatively as a function of temperature and concentration. The adsorption process was found to increases with increase in temperature and concentration. The selectivity order for alpha-titanium and alpha-tin phosphates is Cu(2+)>Co(2+)>Ni(2+), whereas for alpha-zirconium phosphate it is Cu(2+)>Ni(2+)>Co(2+). The ion exchange capacity of alpha-titanium phosphate is greater than those of other phosphates, which is explained on the basis of the surface behavior, disorderness of the system, degree of hydrolysis of incoming guest adsorbate metal ions, and structural steric hindrance of the exchangers during adsorption and sorption. The distribution coefficient, Gibbs free energy, enthalpy, and entropy values indicate that the ion-exchange processes are spontaneous. PMID:14697711

  4. Experimental Characterization and Modelization of Ion Exchange Kinetics for a Carboxylic Resin in Infinite Solution Volume Conditions. Application to Monovalent-Trivalent Cations Exchange

    International Nuclear Information System (INIS)

    This study is devoted to the characterization of ion exchange inside a microsphere of carboxylic resin. It aims at describing the kinetics of this exchange reaction which is known to be controlled by interdiffusion in the particle. The fractional attainment of equilibrium function of time depends on the concentration of the cations in the resin which can be modelled by the Nernst-Planck equation. A powerful approach for the numerical resolution of this equation is introduced in this paper. This modeling is based on the work of Helfferich but involves an implicit numerical scheme which reduces the computational cost. Knowing the diffusion coefficients of the cations in the resin and the radius of the spherical exchanger, the kinetics can be hence completely determined. When those diffusion parameters are missing, they can be deduced by fitting experimental data of fractional attainment of equilibrium. An efficient optimization tool coupled with the implicit resolution has been developed for this purpose. A monovalent/trivalent cation exchange had been experimentally characterized for a carboxylic resin. Diffusion coefficients and concentration profiles in the resin were then deduced through this new model. (authors)

  5. Recover of some rare earth elements from leach liquor of the Saghand uranium ore using combined precipitation and cation exchange methods

    International Nuclear Information System (INIS)

    In this research work, the recovery and separation of La(III), Ce(III), Sm(III), Dy(III) and Nd(III) from Saghand uranium ore have been studied by precipitation and ion-exchange chromatography methods using Dowex 50 W-X 8 cation exchanger. At first, some preliminary and preconcentration experiments such as comminution, sieve analysis, gravity table and electrostatic in preconcentration of lanthanides were performed. Then, acidic digesting and leaching procedure were used. The results of experiments showed that rare earth elements, along with interfering ions such as Al(III), Fe(III), Mg(II) and Mn(II) present in the leach liquor solution. The investigation of separation process by precipitation method revealed that precipitation and then fast separation using centrifugal technique had the best results in the elimination of interference elements. In order to separate the lanthanides and to obtain their elution curves, the chromatographic column containing Dowex 50 W-X 8 resin was employed. For efficient separation of lanthanides from interference elements the hydrochloric acid with concentration of two and six molar was used respectively. Recovery of lanthanides from the leach liquor solution was achieved more than 85%

  6. Effect of the intercalated cation-exchanged on the properties of nanocomposites prepared by 2-aminobenzene sulfonic acid with aniline and montmorillonite

    International Nuclear Information System (INIS)

    Polymer/montmorillonite nanocomposites were prepared. Intercalation of 2-aminobenzene sulfonic acid with aniline monomers into montmorillonite modified by cation was followed by subsequent oxidative polymerization of monomers in the interlayer spacing. The clay was prepared by cation exchange process between sodium cation in (M–Na) and copper cation (M–Cu). XRD analyses show the manifestation of a basal spacing (d-spacing) for M–Cu changes depending on the inorganic cation and the polymer intercalated in the M–Cu structure. TGA analyses reveal that polymer/M–Cu composites is less stable than M–Cu. The conductivity of the composites is found to be 103 times higher than that for M–Cu. The microscopic examinations including TEM picture of the nanocomposite demonstrated an entirely different and more compatible morphology. Remarkable differences in the properties of the polymers have also been observed by UV–Vis and FTIR, suggesting that the polymer produced with presence of aniline has a higher degree of branching. The electrochemical behavior of the polymers extracted from the nanocomposites has been studied by cyclic voltammetry which indicates the electroactive effect of nanocomposite gradually increased with aniline in the polymer chain.

  7. [Effects of biochar amendment on cropland soil bulk density, cation exchange capacity, and particulate organic matter content in the North China Plain].

    Science.gov (United States)

    Chen, Hong-Xia; Du, Zhang-Liu; Guo, Wei; Zhang, Qing-Zhong

    2011-11-01

    A 3-year field experiment with randomized block design was conducted to study the effects of biochar amendment on the soil bulk density, cation exchange capacity (CEC), and particulate organic matter C (POM-C) and N (POM-N) contents in a high-yielding cropland in the North China Plain. Four treatments were installed, i.e., chemical NPK (CK), chemical NPK plus 2250 kg x hm(-2) of biochar (C1), chemical NPK plus 4500 kg x hm(-2) of biochar (C2), and 750 kg x hm(-2) of biochar-based slow release fertilizer (CN). Comparing with CK, treatments C1 and C2 significantly decreased the bulk density of 0-7.5 cm soil layer by 4.5% and 6.0%, respectively, and the treatments with biochar amendment increased the CEC in 0-15 cm soil layer, with an increment of 24.5% in treatment C2. Biochar amendment also increased the C (POM-C) and N (POM-N) contents in 0-7.5 cm soil layer, e.g., the POM-C and N contents in treatment C1 and C2 were 250% and 85%, and 260% and 120% higher than those of the CK, respectively. After three years of biochar amendment, the soil had obvious improvement in its physical and chemical properties, and played more active roles in soil carbon sequestration and greenhouse gases emission reduction. PMID:22303671

  8. High-purity isolation of anthocyanins mixtures from fruits and vegetables--a novel solid-phase extraction method using mixed mode cation-exchange chromatography.

    Science.gov (United States)

    He, Jian; Giusti, M Monica

    2011-11-01

    Research on biological activity of anthocyanins requires the availability of high purity materials. However, current methods to isolate anthocyanins or anthocyanin mixtures are tedious and expensive or insufficient for complete isolation. We applied a novel cation-exchange/reversed-phase combination solid-phase extraction (SPE) technique, and optimized the use of water/organic buffer mobile phases to selectively separate anthocyanins. Crude extracts of various representative anthocyanin sources were purified with this technique and compared to 3 commonly used SPE techniques: C(18), HLB, and LH-20. Purified anthocyanin fractions were analyzed with high performance liquid chromatography (HPLC) coupled to photodiode array (PDA) and mass spectrometry (MS) detectors and by Fourier transform infrared (FT-IR) spectroscopy. The UV-visible chromatograms quantitatively demonstrated that our novel technique achieved significantly higher (Pmethod, for 11 of the 12 anthocyanin sources tested. Among them, eight were purified to greater than 99% purity (based on UV-visible chromatograms). The new method efficiently removed non-anthocyanin phenolics. MS and FT-IR results semi-quantitatively confirmed extensive reduction of impurities. Due to strong ionic interaction, our sorbent capacity was superior to others, resulting in the highest throughput and least use of organic solvents. This new methodology for isolation of anthocyanin mixtures drastically increased purity and efficiency while maintaining excellent recovery rate and low cost. The availability of high purity anthocyanin mixtures will facilitate anthocyanin studies and promote the application of anthocyanins in the food and nutraceutical industries. PMID:21968344

  9. A comparative account of the wet oxidation of cation exchange resin with hydrogen peroxide using titanium, vanadium, and molybdenum doped MCM-41 as catalysts

    International Nuclear Information System (INIS)

    Ion exchange resins are widely used in the nuclear industry for treatment of radioactive waste as well as for the upgrading of heavy water used in the primary heat transport system and moderator system. Repeated usage of the resins calls for replacement and treatment before disposal. The present work involves the application of metal-doped MCM-41 material as a catalyst for the wet oxidation of cation exchange resins using hydrogen peroxide as an oxidizing agent. The sulfate produced from the exchangeable group of the resin reflects the extent of decomposition and the carbonate produced reflects the extent of oxidation of the ion exchange resin. Results indicate that the percentage decomposition and oxidation increase with the weight of the catalyst and the volume of the oxidant, i.e., hydrogen peroxide. As much as 0.5 g of the resin could be decomposed by 12 mL of 30% hydrogen peroxide to 98.7% and oxidized to 99.25% using molybdenum doped MCM-41. Vanadium doped and titanium doped MCM-41 required 14 to 16 mL for complete decomposition and 18 to 20 mL for complete oxidation of the ion exchange resin. (orig.)

  10. Review of the thermal stability and cation exchange properties of the zeolite minerals clinoptilolite, mordenite, and analcime; applications to radioactive waste isolation in silicic tuff

    International Nuclear Information System (INIS)

    Silicic tuffs of the southern Great Basin and basalts of the Columbia River Plateau are under investigation as potential host rocks for high- and intermediate-level radioactive wastes. Nonwelded and partially welded tuffs may contain major amounts (> 50%) of the zeolite minerals clinoptilolite, mordenite, and analcime. Densely welded tuffs and some basalt flows may contain clinoptilolite as fracture filling that limits the permeability of these rocks. The cation exchange properties of these zeolite minerals allow them to pose a formidable natural barrier to the migration of cationic species of various radionuclides in aqueous solutions. However, these minerals are unstable at elevated temperatures and at low water-vapor pressures and may break down either by reversible dehydration or by irreversible mineralogical reactions. All the breakdown reactions occurring at increased temperature involve a net volume reduction and evolution of fluids. Thus, they may provide a pathway (shrinkage fractures) and a driving force (fluid pressure) for release of radionuclides to the biosphere. These reactions may be avoided by keeping zeolite-bearing horizons saturated with water and below about 850C. This may restrict allowable gross thermal loadings in waste repositories in volcanic rocks

  11. Preparation and characterization of electrically conducting polypyrrole Sn(IV phosphate cation-exchanger and its application as Mn(II ion selective membrane electrode

    Directory of Open Access Journals (Sweden)

    A.A. Khan

    2011-10-01

    Full Text Available Polypyrrole Sn(IV phosphate, an organic–inorganic composite cation-exchanger was synthesized via sol-gel mixing of an organic polymer, polypyrrole, into the matrices of the inorganic precipitate of Sn(IV phosphate. The physico-chemical properties of the material were determined using Atomic Absorption Spectrometry (AAS, CHN elemental analysis (inductively coupled plasma mass spectrometry, ICP-MS, UV–VIS spectrophotometry, FTIR (Fourier Transform Infra-Red, SEM (Scanning Electron Microscopy, TGA–DTA (Thermogravimetric Analysis–Differential Thermal Analysis, and XRD (X-ray diffraction. Ion-exchange behavior was observed to characterize the material. On the basis of distribution studies, the material was found to be highly selective for toxic heavy metal ion Mn2+. Due to its selective nature, the material was used as an electroactive component for the construction of an ion-selective membrane electrode. The proposed electrode shows fairly good discrimination of mercury ion over several other inorganic ions. The analytical utility of this electrode was established by employing it as an indicator electrode in electrometric titrations for Mn(II in water.

  12. Sequential Determination of Total Arsenic and Cadmium in Concentrated Cadmium Sulphate Solutions by Flow-Through Stripping Chronopotentiometry after Online Cation Exchanger Separation

    Directory of Open Access Journals (Sweden)

    Frantisek Cacho

    2012-01-01

    Full Text Available Flow-through stripping chronopotentiometry with a gold wire electrode was used for the determination of total arsenic and cadmium in cadmium sulphate solutions for cadmium production. The analysis is based on the online separation of arsenic as arsenate anion from cadmium cations by means of a cation exchanger. On measuring arsenate in the effluent, the trapped cadmium is eluted by sodium chloride solution and determined in a small segment of the effluent by making use of the same electrode. The elaborated protocol enables a full automatic measurement of both species in the same sample solution. The accuracy of the results was confirmed by atomic absorption spectrometry. The LOD and LOQ for Arsenic were found to be 0.9 μg dm-3 and 2.7 μg dm-3, respectively. A linear response range was observed in the concentration range of 1 to 300 μg dm-3 for sample volumes of 4 mL. The repeatability and reproducibility were found to be 2.9% and 5.2%, respectively. The linear response range for cadmium was found to be 0.5 to 60 g/L. The method was tested on samples from a cadmium production plant.

  13. Effect of the intercalated cation-exchanged on the properties of nanocomposites prepared by 2-aminobenzene sulfonic acid with aniline and montmorillonite

    Energy Technology Data Exchange (ETDEWEB)

    Toumi, I. [Laboratoire de Chimie Organique, Macromoleculaire et des Materiaux, Universite de Mascara, Bp 763 Mascara 29000 (Algeria); Benyoucef, A., E-mail: ghani29000@yahoo.fr [Laboratoire de Chimie Organique, Macromoleculaire et des Materiaux, Universite de Mascara, Bp 763 Mascara 29000 (Algeria); Yahiaoui, A. [Laboratoire de Chimie Organique, Macromoleculaire et des Materiaux, Universite de Mascara, Bp 763 Mascara 29000 (Algeria); Quijada, C. [Departamento de Ingenieria Textil y Papelera, Universidad Politecnica de Valencia, Pza Ferrandiz i Carbonel, E-03801 Alcoy, Alicante (Spain); Morallon, E. [Departamento de Quimica Fisica e Instituto Universitario de Materiales, Universidad de Alicante, Apartado 99, E-03080 Alicante (Spain)

    2013-02-25

    Polymer/montmorillonite nanocomposites were prepared. Intercalation of 2-aminobenzene sulfonic acid with aniline monomers into montmorillonite modified by cation was followed by subsequent oxidative polymerization of monomers in the interlayer spacing. The clay was prepared by cation exchange process between sodium cation in (M-Na) and copper cation (M-Cu). XRD analyses show the manifestation of a basal spacing (d-spacing) for M-Cu changes depending on the inorganic cation and the polymer intercalated in the M-Cu structure. TGA analyses reveal that polymer/M-Cu composites is less stable than M-Cu. The conductivity of the composites is found to be 10{sup 3} times higher than that for M-Cu. The microscopic examinations including TEM picture of the nanocomposite demonstrated an entirely different and more compatible morphology. Remarkable differences in the properties of the polymers have also been observed by UV-Vis and FTIR, suggesting that the polymer produced with presence of aniline has a higher degree of branching. The electrochemical behavior of the polymers extracted from the nanocomposites has been studied by cyclic voltammetry which indicates the electroactive effect of nanocomposite gradually increased with aniline in the polymer chain.

  14. Cation exchange-based post-processing of 68Ga-eluate: A comparison of three solvent systems for labelling of DOTATOC, NO2APBP and DATAm

    International Nuclear Information System (INIS)

    Interest in 68Ga has led to a number of innovations for its provision suitable for clinical application. Several post-processing methods are available to reduce eluate volume and remove metal trace impurities. In this work three cation exchange resin based post-processing methods (acetone, ethanol and NaCl) have been compared, using three model precursors (DOTATOC, NO2APBP and DATAm), in terms of labelling yield and reproducibility. The acetone and ethanol based methods provided greater reproducibility and yields that makes subsequent purification unnecessary. - Highlights: • Comparison of different 68Ga post-processing methods through the labelling of DOTATOC, NO2APBP and DATAm. • Comparison in terms of radiochemical yield, reproducibility and radiolysis. • Ethanol and acetone post-processed 68Ga facilitated the highest yields and reproducibility. • Ethanol post-processed 68Ga resulted in the lowest degree of radiolysis of 68Ga-DOTATOC. • Experimenting with different post-processing methods is an important optimisation step. • Ethanol-post processed 68Ga is suitable for clinical application

  15. Use of potassium-form cation-exchange resin as a conductimetric enhancer in ion-exclusion chromatography of aliphatic carboxylic acids.

    Science.gov (United States)

    Iwata, Tomotaka; Mori, Masanobu; Itabashi, Hideyuki; Tanaka, Kazuhiko

    2009-09-15

    In this study, a cation-exchange resin (CEX) of the K(+)-form, i.e., an enhancer resin, is used as a postcolumn conductimetric enhancer in the ion-exclusion chromatography of aliphatic carboxylic acids. The enhancer resin is filled in the switching valve of an ion chromatograph; this valve is usually used as a suppressor valve in ion-exchange chromatography. An aliphatic carboxylic acid (e.g., CH(3)COOH) separated by a weakly acidic CEX column of the H(+)-form converts into that of the K(+)-form (e.g., CH(3)COOK) by passing through the enhancer resin. In contrast, the background conductivity decreases because a strong acid (e.g., HNO(3)) with a higher conductimetric response in an eluent converts into a salt (e.g., KNO(3)) with a lower conductimetric response. Since the pH of the eluent containing the resin enhancer increases from 3.27 to 5.85, the enhancer accelerates the dissociations of analyte acids. Consequently, peak heights and peak areas of aliphatic carboxylic acids (e.g., acetic acid, propionic acid, butyric acid, and valeric acid) with the enhancer resin are 6.3-8.0 times higher and 7.2-9.2 times larger, respectively, than those without the enhancer resin. Calibrations of peak areas for injected analytes are linear in the concentration range of 0.01-1.0mM. The detection limits (signal-to-noise ratio=3) range from 0.10 microM to 0.39 microM in this system, as opposed to those in the range of 0.24-7.1 microM in the separation column alone. The developed system is successfully applied to the determination of aliphatic carboxylic acids in a chicken droppings sample. PMID:19615503

  16. Onset of size independent cationic exchange in nano-sized CoFe{sub 2}O{sub 4} induced by electronic excitation

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Hemaunt [Department of Physics, Govind Ballabh Pant University of Agriculture and Technology, Pantnagar, Uttarakhand 263145 (India); Singh, Jitendra Pal, E-mail: jitendra_singh2029@rediffmail.com [Advanced Analysis Canter, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Srivastava, R.C.; Negi, P.; Agrawal, H.M. [Department of Physics, Govind Ballabh Pant University of Agriculture and Technology, Pantnagar, Uttarakhand 263145 (India); Asokan, Kandasami [Materials Science Division, Inter University Accelerator Centre, New Delhi 110067 (India); Won, Sung Ok [Advanced Analysis Canter, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Chae, Keun Hwa, E-mail: khchae@kist.re.kr [Advanced Analysis Canter, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of)

    2015-10-05

    Highlights: • Electronic excitation induced crystalline order in CoFe{sub 2}O{sub 4}. • No change of metallic valence state under dense electronic excitation. • Size independent control of cations in CoFe{sub 2}O{sub 4}. - Abstract: Present work investigates electronic excitation induced cationic exchange phenomena in nano-sized cobalt ferrites using Mössabaur and X-ray absorption spectroscopies. The electronic excitations were produced by irradiation of 100 MeV O{sup +7} at different fluences ranging from 1 × 10{sup 11} to 1 × 10{sup 14} ions/cm{sup 2}. Cubic spinel phase of cobalt ferrite remains preserved after irradiation. However, attributes of crystalline disorder were observed in irradiated materials. Crystallite size remain almost same for pristine and irradiated materials. X-ray absorption fine structure measurements show the preservation of valence state and spin state of metal ions under intense electronic excitation. These measurements also envisage bond breaking process induced by the electronic excitation. Mössbauer spectroscopic measurements also corroborate with the fine structure measurements that the valence state of Fe remains same after irradiation. Paramagnetic doublet which presents in the Mössabaur spectrum of pristine material disappears after irradiation, showing the evolution of irradiation induced magnetic ordering. Fe{sup 3+} ion increases with irradiation at octahedral site of spinel lattice. Magnetization of the material slightly increases after irradiation at the fluence of 5 × 10{sup 13} and 1 × 10{sup 14} ions/cm{sup 2}.

  17. Changes of mineralogical-chemical composition, cation exchange capacity, and phosphate immobilization capacity during the hydrothermal conversion process of coal fly ash into zeolite

    Energy Technology Data Exchange (ETDEWEB)

    Deyi Wu; Yanming Sui; Xuechu Chen; Shengbing He; Xinze Wang; Hainan Kong [Shanghai Jiao Tong University, Shanghai (China). School of Environmental Science and Engineering

    2008-08-15

    In the search for a technique to augment the nutrient removal capacity of zeolite synthesized from fly ash (ZFA), the present study investigated the changes of mineralogical-chemical composition, cation exchange capacity (CEC), and phosphate immobilization capacity (PIC) during the synthesis process. The ZFAs were obtained as a function of temperature (40-120{sup o}C), liquid/solid ratio (1-18 ml/g), NaOH concentration (0.5-4 mol/L) and reaction time (2-72 h). The formation of low-silica zeolites (P1, hydroxysodalite, and chabazite) and the stability of mullite were observed, causing a marked decrease in SiO{sub 2} content but roughly no change in Al{sub 2}O{sub 3} content during the synthesis process. The decrease in K{sub 2}O, MgO content and the insignificant change in Fe{sub 2}O{sub 3} and TiO{sub 2} content were related to the solubility of the oxides while the increase in Na{sub 2}O and CaO was due to the increase in CEC. A high CEC was achieved under a high temperature, a high liquid/solid ratio, a long reaction time, and an appropriate NaOH concentration (2 mol/L), while a maximum PIC was achieved under relatively mild synthesis conditions instead (e.g., a reasonably short reaction time 10 h). This discrepancy was explained by the fact that different controlling factors/components in ZFA are responsible for CEC (content and kind of zeolite) and PIC (Ca component, specific surface area, and dissociated Fe{sub 2}O{sub 3} and Al{sub 2}O{sub 3}). 20 refs., 4 figs., 2 tabs.

  18. chemical studies and sorption behavior of some hazardous metal ions on polyacrylamide stannic (IV) molybdophosphate as 'organic - inorganic' composite cation - exchanger

    International Nuclear Information System (INIS)

    compsite materials formed by the combination of multivalent metal acid salts and organic polymers provide a new class of (organic-inorganic) hypride ion exchangers with better mechanical and granulometric properties, good ion-exchange capacity, higher chemical and radiation stabilites, reproducibility and selectivity for heavy metals. this material was characterized using X-ray (XRD and XRF), IR, TGA-DTA and total elemental analysis studies. on the basis of distribution studies, the material has been found to be highly selective for pb(II). thermodynamic parameters (i.e δG0, δ S0 and δH0) have also been calculated for the adsorption of Pb2+, Cs+, Fe3+, Cd2+, Cu+2, Zn2+, Co2+ and Eu3+ions on polyacrylamide Sn(IV) molybdophosphate showing that the overall adsorption process is spontaneous endothermic. the mechanism of diffusion of Fe3+, Co2+, Cu+2, Zn2+, Cd2+, Cs+, Pb2+ and Eu3+ in the H-form of polyacrylamide Sn(IV) molybdophosphate composite as cation exchanger was studied as a function of particle size, concentration of the exchanging ions, reaction temperature, dring temperature and pH. the exchange rate was controlled by particle diffusion mechanism as a limited batch techneque and is confirmed from straight lines of B versus 1/r2 polts. the values of diffusion coefficients, activation energy and entropy of activation were calculated and their significance was discussed. the data obtained have been comared with that reported for other organic and inorganic exchangers.

  19. A novel approach to measure elemental concentrations in cation exchange resins using XRF-scanning technique, and its potential in water pollution studies

    Science.gov (United States)

    Huang, Jyh-Jaan; Lin, Sheng-Chi; Löwemark, Ludvig; Liou, Ya-Hsuan; Chang, Queenie; Chang, Tsun-Kuo; Wei, Kuo-Yen; Croudace, Ian W.

    2016-04-01

    X-ray fluorescence (XRF) core-scanning is a fast, and convenient technique to assess elemental variations for a wide variety of research topics. However, the XRF scanning counts are often considered a semi-quantitative measurement due to possible absorption or scattering caused by down core variability in physical properties. To overcome this problem and extend the applications of XRF-scanning to water pollution studies, we propose to use cation exchange resin (IR-120) as an "elemental carrier", and to analyze the resins using the Itrax-XRF core scanner. The use of resin minimizes the matrix effects during the measurements, and can be employed in the field in great numbers due to its low price. Therefore, the fast, and non-destructive XRF-scanning technique can provide a quick and economical method to analyze environmental pollution via absorption in the resin. Five standard resin samples were scanned by the Itrax-XRF core scanner at different exposure times (1 s, 5 s, 15 s, 30 s, 100 s) to allow the comparisons of scanning counts with the absolute concentrations. The regression lines and correlation coefficients of elements that are generally used in pollution studies (Ca, Ti, Cr, Ni, Cu, Zn, and Pb) were examined for the different exposure times. The result shows that within the test range (from few ppm to thousands ppm), the correlation coefficients are all higher than 0.97, even at the shortest exposure time (1 s). Therefore, we propose to use this method in the field to monitor for example sewage disposal events. The low price of resin, and fast, multi elements and precise XRF-scanning technique provide a viable, cost- and time-effective approach that allows large sample numbers to be processed. In this way, the properties and sources of wastewater pollution can be traced for the purpose of environmental monitoring and environmental forensics.

  20. 2-Acrylamido-2-methyl-1-propanesulfonic Acid Grafted Poly(vinylidene fluoride-co-hexafluoropropylene)-Based Acid-/Oxidative-Resistant Cation Exchange for Membrane Electrolysis.

    Science.gov (United States)

    Pandey, Ravi P; Das, Arindam K; Shahi, Vinod K

    2015-12-30

    For developing acid-/oxidative-resistant aliphatic-polymer-based cation-exchange membrane (CEM), macromolecular modification of poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-co-HFP) was carried out by controlled chemical grafting of 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS). To introduce the unsaturation suitable for chemical grafting, dehydrofluorination of commercially available PVDF-co-HFP was achieved under alkaline medium. Sulfonated copolymer (SCP) was prepared by the free radical copolymerization of dehydofluorinated PVDF-co-HFP (DHPVDF-co-HFP) and AMPS in the presence of free radical initiator. Prepared SCP-based CEMs were analyzed for their morphological characteristics, ion-exchange capacity (IEC), water uptake, conductivity, and stabilities (mechanical, chemical, and thermal) in comparison with state-of-art Nafion117 membrane. High bound water content avoids the membrane dehydration, and most optimal (SCP-1.33) membrane exhibited about ∼2.5-fold high bound water content in comparison with that of Nafion117 membrane. Bunsen reaction of iodine-sulfur (I-S) was successfully performed by direct-contact-mode membrane electrolysis in a two-compartment electrolytic cell using different SCP membranes. High current efficiency (83-99%) confirmed absence of any side reaction and 328.05 kJ mol-H2(-1) energy was required for to produce 1 mol of H2 by electrolytic cell with SCP-1.33 membrane. In spite of low conductivity for reported SCP membrane in comparison with that of Nafion117 membrane, SCP-1.33 membrane was assessed as suitable candidate for electrolysis because of its low-cost nature and excellent stabilities in highly acidic environment may be due to partial fluorinated segments in the membrane structure. PMID:26642107

  1. 襄阳市农田土壤阳离子交换量的测定及分析%Measurement and analysis of farmland soil cation exchange capacity in Xiangyang

    Institute of Scientific and Technical Information of China (English)

    赵翔

    2016-01-01

    Soil cation exchange capacity ( CEC) can reflect the level of soil fertility, fertilizer retention capacity and buffering capacity. Throughinvestigation, sampling and laboratory analysis of soil cation exchange capacity of 16 spot in Xiangyang city, we discovered that the CEC of Xiangyang soil are concentrated in the 15-20 cmol/kg , which belongs to the medium fertility soil. At the same time, through the determination of soil physiochemical indexes, such as the content of soil organic matter,PH value, we discovery that they are very good cor-relation to soil cation exchange capacity.%土壤阳离子交换量CEC能够综合反映土壤肥力水平、保肥能力和缓冲能力。通过对襄阳市16个点位农田土壤实地调查、采集及实验室分析测定土壤阳离子交换量,发现襄阳市农田土壤阳离子交换量多集中在15-20 cmol/kg,属于中等偏上保肥能力土壤,同时通过测定土壤有机质含量,PH值等土壤理化指标,发现与土壤阳离子交换量存在很好的相关性。

  2. Heart Regeneration

    OpenAIRE

    Laflamme, Michael A.; Charles E. Murry

    2011-01-01

    Heart failure plagues industrialized nations, killing more people than any other disease. Heart failure usually results from a deficiency of cardiomyocytes, and a robust therapy to regenerate lost myocardium could help millions of patients a year. Heart regeneration is well documented in lower vertebrates and in developing mammals. After we are born, however, human heart regeneration becomes limited. In this article, Laflamme and Murry review the innate barriers to heart regeneration, the evi...

  3. Cryogenic regenerators

    International Nuclear Information System (INIS)

    Importance of regenerators in cryogenic refrigerators is highlighted. Design aspects of regenerator are reviewed and the factors involved in the selection of regenerator material are enumerated. Various methods used to calculate the heat transfer coefficient and regenerator effectiveness are mentioned. Variation of effectiveness with various parameters is calculated by a computer programme using the ideal, Ackermann and Tipler formulae. Results are presented in graphical form. Listing of the computer programme is given in the Appendix. (author)

  4. Enhanced Brine Dewatering System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The purpose of the Enhanced Brine Dewatering System (EBDS) is to provide an easily scalable means of completely recovering usable water from byproducts created by...

  5. Enhanced Brine Dewatering System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The purpose of the Enhanced Brine Dewatering System (EBDS) is to provide a scalable means of completely recovering usable water from byproducts created by reverse...

  6. SURFACE CONTAINMENT FOR GEOTHERMAL BRINES

    Science.gov (United States)

    This report examines the probability of significant releases of geothermal brine to the surface environment through unplanned or accidental events. It then evaluates the containment measures that may be used to prevent environmental damage. The results indicate that major spills ...

  7. Applying reactive models to column experiments to assess the hydrogeochemistry of seawater intrusion: Optimising ACUAINTRUSION and selecting cation exchange coefficients with PHREEQC

    Science.gov (United States)

    Boluda-Botella, N.; Valdes-Abellan, J.; Pedraza, R.

    2014-03-01

    Three sets of laboratory column experimental results concerning the hydrogeochemistry of seawater intrusion have been modelled using two codes: ACUAINTRUSION (Chemical Engineering Department, University of Alicante) and PHREEQC (U.S.G.S.). These reactive models utilise the hydrodynamic parameters determined using the ACUAINTRUSION TRANSPORT software and fit the chloride breakthrough curves perfectly. The ACUAINTRUSION code was improved, and the instabilities were studied relative to the discretisation. The relative square errors were obtained using different combinations of the spatial and temporal steps: the global error for the total experimental data and the partial error for each element. Good simulations for the three experiments were obtained using the ACUAINTRUSION software with slight variations in the selectivity coefficients for both sediments determined in batch experiments with fresh water. The cation exchange parameters included in ACUAINTRUSION are those reported by the Gapon convention with modified exponents for the Ca/Mg exchange. PHREEQC simulations performed using the Gains-Thomas convention were unsatisfactory, with the exchange coefficients from the database of PHREEQC (or range), but those determined with fresh water - natural sediment allowed only an approximation to be obtained. For the treated sediment, the adjusted exchange coefficients were determined to improve the simulation and are vastly different from those from the database of PHREEQC or batch experiment values; however, these values fall in an order similar to the others determined under dynamic conditions. Different cation concentrations were simulated using two different software packages; this disparity could be attributed to the defined selectivity coefficients that affect the gypsum equilibrium. Consequently, different calculated sulphate concentrations are obtained using each type of software; a smaller mismatch was predicted using ACUAINTRUSION. In general, the presented

  8. A versatile reversed phase-strong cation exchange-reversed phase (RP-SCX-RP) multidimensional liquid chromatography platform for qualitative and quantitative shotgun proteomics.

    Science.gov (United States)

    Law, Henry C H; Kong, Ricky P W; Szeto, Samuel S W; Zhao, Yun; Zhang, Zaijun; Wang, Yuqiang; Li, Guohui; Quan, Quan; Lee, Simon M Y; Lam, Herman C; Chu, Ivan K

    2015-02-21

    An automatable, robust, high-performance online multidimensional liquid chromatography (MDLC) platform comprising of pH 10 reversed-phase (RP), strong cation exchange (SCX), and pH 2 RP separation stages has been integrated into a modified commercial off-the-shelf LC instrument with a simple rewiring, enabling accelerated routine qualitative and quantitative proteomics analyses. This system has been redesigned with a dual-trap column configuration to improve the throughput by greatly decreasing the system idle time. The performance of this new design has been benchmarked through analysis of the total lysate of S. cerevisiae, in comparison with that of the former tailor-made system featuring more complicated components; the total run time per "load-and-go" LC/MS analysis was approximately 24 h, with minimal idle time and no labor-intensive steps. This platform features high-resolution fractionations, ease of use and a high degree of user programmability in the first two chromatographic dimensions, allowing flexible and effective sampling with (RP-SCX-RP) or without (RP-RP) the inclusion of SCX sub-fractionation; good proteome coverage and reproducibility was demonstrated through the analyses of bacterial, cell culture, and monkey brain tissue proteomes. The viability of the 3D RP-SCX-RP has been proven in proteome-wide studies of STO fibroblasts and yeast tryptic digests, resulting in extended proteome and protein coverages with high reproducibility-in particular, discovering extra-hydrophilic peptides-at the expense of the acquisition time. The identified inventory of the rat pheochromocytoma PC12 cell proteome-a total of 6345 proteins and 97 309 unique peptides is the most comprehensive dataset to date-provides an example of the value of the 3D RP-SCX-RP. The use of orthogonal chromatographic dimensions in the 3D RP-SCX-RP also circumvents the issues of isobaric interference of mass-tagging background contaminations, while significantly improving the accuracy of

  9. Effects of Land Use Practices on the Organic Carbon Content, Cation Exchange Capacity and Aggregate Stability of Soils in the Catchment Zones

    Directory of Open Access Journals (Sweden)

    Mosayeb Heshmati

    2011-01-01

    Full Text Available Problem statement: Land use practice leads to changes in the physico-chemical properties of soils, such as Soil Organic Carbon (SOC, Cation Exchange Capacity (CEC and Soil Aggregate Stability (SAS that cause soil erosion. Approach: Merek catchment, Iran suffers from land degradation due to poor land use practice. A study was carried out with the objectives: (i to determine soil nutrient status in different agro-ecological zones in Merek catchment; and (ii to evaluate the influence of land use practices on SOC, CEC and SAS. Results: It was found that soil texture was silty and clay, while soil reaction was alkaline (pH was 7.75. The respective amount of carbonates was 32 and 36% in the top-soil and sub-soil respectively, indicating high level of alkalinity in the soils of the study area. The mean SAS of the surface soil layer for agriculture, rangeland and forest was 53, 61 and 64%, respectively with its mean in the topsoil of agriculture is significantly lower (P≤0.05 than the other zones. SOC level in the agriculture, rangeland and forest were 1.35, 1.56, 2.14 % in the topsoil and 1.03, 1.33 and 1.45%, in the subsoil of the respective areas. The results of t-test and ANOVA analyses showed that SOC means are significantly different from each other within soil depth and among agro-ecological zones. The CEC in the agriculture, rangeland and forest areas were 25.8, 24.6 and 35.1 cmolckg-1 for the top-soil and 31.1, 26.8 and 26.9 cmolckg-1 in the sub-soil, respectively. All the above changes are due to the negative effects of agricultural activities. Conclusion: Improper tillage practice (up-down the slope, conversion of the rangeland and forest to rain-fed areas, crop residue burning, over grazing and forest clearance contribute to reduction in SOC and SAS in the Merek catchment, Iran.

  10. Tandem anion and cation exchange solid phase extraction for the enrichment of micropollutants and their transformation products from ozonation in a wastewater treatment plant.

    Science.gov (United States)

    Deeb, Ahmad A; Schmidt, Torsten C

    2016-06-01

    The presence of organic micropollutants and their transformation products (TPs) from biotic and abiotic processes in aquatic environments is receiving intense public and scientific attention. Yet a suitable sample preparation method that would enable extraction and enrichment of a wide range of such compounds from water is missing. The focus of this paper was to develop an enhanced solid phase extraction (SPE) protocol which enabled isolation of parent compounds and low molecular weight transformation products (that are produced after treatment of water with ozone) from different water matrices. Ten SPE sorbents were evaluated with regard to their ability to extract acidic, neutral, and basic compounds from water at several pH values. Highest recoveries (91-99 %) for all analytes in pure water were obtained by combining strong anion and cation exchangers of two manufacturers in a tandem mode without pH adjustment. Tandem Oasis (MAX+MCX) was finally applied to extract the spiked analytes from tap water, surface water, and several wastewater samples. The efficiency of the used SPE procedure was examined using an optimized liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) method using multiple reaction monitoring (MRM) mode. The occurrence of some of the investigated TPs in environmental water matrices was proven for the first time in this study. Method quantification limits (MQLs) for all compounds ranged from 3.7 to 15.3 ng/L in all matrices. Recoveries (%RE) were between 90 and 110 %. Intraday and interday precision, expressed as relative standard deviation, varied from 0.7 to 5.9 % and 1.8 to 10.3 %, respectively. Matrix effect (%ME) evaluation demonstrated that even complex sample matrices did not show significant ion suppression or enhancement. The applicability of the method was shown during two sampling campaigns at Ruhr river and a wastewater treatment plant (WWTP) equipped with an ozonation step after regular

  11. Extraction of lithium from salt lake brine using room temperature ionic liquid in tributyl phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Chenglong [Key Laboratory of Salt Lake Resources and Chemistry, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, 810008 Xining (China); University of Chinese Academy of Sciences, 100049 Beijing (China); Jia, Yongzhong [Key Laboratory of Salt Lake Resources and Chemistry, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, 810008 Xining (China); Zhang, Chao [Key Laboratory of Salt Lake Resources and Chemistry, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, 810008 Xining (China); University of Chinese Academy of Sciences, 100049 Beijing (China); Liu, Hong [Qinghai Salt Chemical Products Supervision and Inspection Center, 816000 Golmud (China); Jing, Yan, E-mail: 1580707906@qq.com [Key Laboratory of Salt Lake Resources and Chemistry, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, 810008 Xining (China)

    2015-01-15

    Highlights: • We proposed a new system for Li recovery from salt lake brine by extraction using an ionic liquid. • Cation exchange was proposed to be the mechanism of extraction followed in ionic liquid. • This ionic liquid system shown considerable extraction ability for lithium and the single extraction efficiency of lithium reached 87.28% under the optimal conditions. - Abstract: Lithium is known as the energy metal and it is a key raw material for preparing lithium isotopes which have important applications in nuclear energy source. In this work, a typical room temperature ionic liquid (RTILs), 1-butyl-3-methyl-imidazolium hexafluorophosphate ([C{sub 4}mim][PF{sub 6}]), was used as an alternative solvent to study liquid/liquid extraction of lithium from salt lake brine. In this system, the ionic liquid, NaClO{sub 4} and tributyl phosphate (TBP) were used as extraction medium, co-extraction reagent and extractant respectively. The effects of solution pH value, phase ratio, ClO{sub 4}{sup −} amount and other factors on lithium extraction efficiency had been investigated. Optimal extraction conditions of this system include the ratio of TBP/IL at 4/1 (v/v), O/A at 2:1, n(ClO{sub 4}{sup −})/n(Li{sup +}) at 2:1, the equilibration time of 10 min and unadjusted pH. Under the optimal conditions, the single extraction efficiency of lithium was 87.28% which was much higher than the conventional extraction system. Total extraction efficiency of 99.12% was obtained by triple-stage countercurrent extraction. Study on the mechanism revealed that the use of ionic liquid increased the extraction yield of lithium through cation exchange in this system. Preliminary results indicated that the use of [C{sub 4}mim][PF{sub 6}] as an alternate solvent to replace traditional organic solvents (VOCs) in liquid/liquid extraction was very promising.

  12. The elution of erbium from a cation exchanger bed by means of the N-hydroxyethyl-ethylene-diamine triacetic acid; Mecanismo de la elucion del erbio en un cambiador cationico con el acido n-hidroxietil-etilen-diamono-triacetico

    Energy Technology Data Exchange (ETDEWEB)

    Amer Amezaga, S.

    1963-07-01

    A physicochemical study of the phenomena resulting when erbium is eluted from a cation-exchanger bed at a steady by means of the N-hydroxyethyl-ethylene-diamine-triacetic acid (HEDTA) is made. Two different retaining beds are used, a hydrogen bed, in which no ammonium passes through, and a zinc bed, which leaks ammonium ion. Good agreement between experimental and calculated values by using the equations deduced for the concentrations of the main species has been achieved, with errors around 1-2% in most of the experiments. (Author) 69 refs.

  13. Brine Sampling and Evaluation Program, 1991 report

    Energy Technology Data Exchange (ETDEWEB)

    Deal, D.E.; Abitz, R.J.; Myers, J.; Martin, M.L.; Milligan, D.J.; Sobocinski, R.W.; Lipponer, P.P.J. [International Technology Corp., Albuquerque, NM (United States); Belski, D.S. [Westinghouse Electric Corp., Carlsbad, NM (United States). Waste Isolation Div.

    1993-09-01

    The data presented in this report are the result of Brine Sampling and Evaluation Program (BSEP) activities at the Waste Isolation Pilot Plan (WIPP) during 1991. These BSEP activities document and investigate the origins, hydraulic characteristics, extent, and composition of brine occurrences in the Permian Salado Formation and seepage of that brine into the excavations at the WIPP. When excavations began at the WIPP in 1982, small brine seepages (weeps) were observed on the walls. Brine studies began as part of the Site Validation Program and were formalized as a program in its own right in 1985. During nine years of observations (1982--1991), evidence has mounted that the amount of brine seeping into the WIPP excavations is limited, local, and only a small fraction of that required to produce hydrogen gas by corroding the metal in the waste drums and waste inventory. The data through 1990 is discussed in detail and summarized by Deal and others (1991). The data presented in this report describes progress made during the calendar year 1991 and focuses on four major areas: (1) quantification of the amount of brine seeping across vertical surfaces in the WIPP excavations (brine ``weeps); (2) monitoring of brine inflow, e.g., measuring brines recovered from holes drilled downward from the underground drifts (downholes), upward from the underground drifts (upholes), and from subhorizontal holes; (3) further characterization of brine geochemistry; and (4) preliminary quantification of the amount of brine that might be released by squeezing the underconsolidated clays present in the Salado Formation.

  14. Use of a polystyrene-divinylbenzene-based weakly acidic cation-exchange resin column and propionic acid as an eluent in ion-exclusion/adsorption chromatography of aliphatic carboxylic acids and ethanol in food samples.

    Science.gov (United States)

    Mori, Masanobu; Hironaga, Takahiro; Kajiwara, Hiroe; Nakatani, Nobutake; Kozaki, Daisuke; Itabashi, Hideyuki; Tanaka, Kazuhiko

    2011-01-01

    We developed an ion-exclusion/adsorption chromatography (IEAC) method employing a polystyrene-divinylbenzene-based weakly acidic cation-exchange resin (PS-WCX) column with propionic acid as the eluent for the simultaneous determination of multivalent aliphatic carboxylic acids and ethanol in food samples. The PS-WCX column well resolved mono-, di-, and trivalent carboxylic acids in the acidic eluent. Propionic acid as the eluent gave a higher signal-to-noise ratio, and enabled sensitive conductimetric detection of analyte acids. We found the optimal separation condition to be the combination of a PS-WCX column and 20-mM propionic acid. Practical applicability of the developed method was confirmed by using a short precolumn with a strongly acidic cation-exchange resin in the H(+)-form connected before the separation column; this was to remove cations from food samples by converting them to hydrogen ions. Consequently, common carboxylic acids and ethanol in beer, wine, and soy sauce were successfully separated by the developed method. PMID:21558657

  15. Brine Sampling and Evaluation Program, 1990 report

    International Nuclear Information System (INIS)

    The data presented in this report are the result of Brine Sampling and Evaluation Program (BSEP) activities at the Waste Isolation Pilot Plant (WIPP) during 1990. When excavations began in 1982, small brine seepages (weeps) were observed on the walls. These brine occurrences were initially described as part of the Site Validation Program. Brine studies were formalized in 1985. The BSEP activities document and investigate the origins, hydraulic characteristics, extent, and composition of brine occurrences in the Permian Salado Formation and seepage of that brine into the excavations at the WIPP. The brine chemistry is important because it assists in understanding the origin of the brine and because it may affect possible chemical reactions in the buried waste after sealing the repository. The volume of brine and the hydrologic system that drives the brine seepage also need to be understood to assess the long-term performance of the repository. After more than eight years of observations (1982--1990), no credible evidence exists to indicate that enough naturally occurring brine will seep into the WIPP excavations to be of practical concern. The detailed observations and analyses summarized herein and in previous BSEP reports confirm the evidence apparent during casual visits to the underground workings -- that the excavations are remarkably dry

  16. Brine Sampling and Evaluation Program, 1990 report

    Energy Technology Data Exchange (ETDEWEB)

    Deal, D.E.; Abitz, R.J.; Myers, J.; Case, J.B.; Martin, M.L.; Roggenthen, W.M. [International Technology Corp., Albuquerque, NM (United States); Belski, D.S. [Westinghouse Electric Corp., Carlsbad, NM (United States). Waste Isolation Div.

    1991-08-01

    The data presented in this report are the result of Brine Sampling and Evaluation Program (BSEP) activities at the Waste Isolation Pilot Plant (WIPP) during 1990. When excavations began in 1982, small brine seepages (weeps) were observed on the walls. These brine occurrences were initially described as part of the Site Validation Program. Brine studies were formalized in 1985. The BSEP activities document and investigate the origins, hydraulic characteristics, extent, and composition of brine occurrences in the Permian Salado Formation and seepage of that brine into the excavations at the WIPP. The brine chemistry is important because it assists in understanding the origin of the brine and because it may affect possible chemical reactions in the buried waste after sealing the repository. The volume of brine and the hydrologic system that drives the brine seepage also need to be understood to assess the long-term performance of the repository. After more than eight years of observations (1982--1990), no credible evidence exists to indicate that enough naturally occurring brine will seep into the WIPP excavations to be of practical concern. The detailed observations and analyses summarized herein and in previous BSEP reports confirm the evidence apparent during casual visits to the underground workings -- that the excavations are remarkably dry.

  17. Lessons learned from the Febex in situ test: modifications at cation exchange positions by effect of a thermo-hydraulic gradient and the bentonite pore water

    International Nuclear Information System (INIS)

    -hydraulic tests at different scales. From this work, different conclusions have been obtained: 1) although the carbonate content in the FEBEX bentonite is about 0.6 wt.%, an extracting solution at pH 8.2 must be used for avoiding the dissolution of carbonates, due to this dissolution alters the concentration of exchangeable cations increasing and decreasing the calcium and sodium content, respectively; 2) the use of cations highly selective overestimates the potassium at exchange sites due to the liberation of this ion from the illitic layers from the R0 I/S mixed layered clay minerals; 3) the cation composition at interlayers is a powerful buffer of the pH of the pore water, 4) carbonates are dissolved during the process of heating and hydration and sodium at exchange sites is replaced by calcium from the solution; 5) the temperature alone does not have a large effect on the bulk cation exchange complex but affects the distribution of the exchangeable cations; 6) the degree of hydration (enhanced by temperature) joint together with the temperature effect has a large effect on the concentration of exchangeable cations. An increase of magnesium concentration at exchange sites is found, as well as a decrease of exchangeable sodium by the interaction of the bentonite with the high ionic strength pore water (Cl-Na-Mg water-type; 7) an overall increase of potassium at exchange sites is found as a consequence of heating and hydration processes; and 8) in those zones with a high water content the CEC increases probably due to pore water pH changes above the zero charge point (ZPC). The increase of potassium and magnesium at exchange sites as a consequence of heating and hydration might be an starting point to a hydrothermal alteration of the bentonite, precluding crystallochemical changes in the smectite: Mg substitution in octahedral sheet and some collapse phenomena in the interlayer region (redistribution of potassium from adjacent crystals). These processes are under study

  18. The Brine Shrimp's Butterfly Stroke

    OpenAIRE

    Johnson, Brennan; Garrity, Deborah; Dasi, Lakshmi Prasad

    2011-01-01

    We investigate the fluid dynamics of brine shrimp larvae swimming in this gallery of fluid motion video. Time resolved particle image velocimetry was performed using nano-particles as seeding material to measure the time dependent velocity and vorticity fields. The Reynolds number of the flow was roughly 8 and the Womerseley number (ratio of periodic forcing to viscous forcing) was about 5. Vorticity dynamics reveals the formation of a vortex ring structure at the tip of each arm at the begin...

  19. NASA TechPort Entry for Coiled Brine Recovery Assembly (CoBRA) CL IR&D Project

    Science.gov (United States)

    Pensinger, Stuart

    2014-01-01

    The Coiled Brine Recovery Assembly (CoBRA) project will result in a proof-of-concept demonstration for a lightweight, compact, affordable, regenerable and disposable solution to brine water recovery. The heart of CoBRA is an evaporator that produces water vapor from brine. This evaporator leverages a novel design that enables passive transport of brine from place to place within the system. While it will be necessary to build or modify a system for testing the CoBRA concept, the emphasis of this project will be on developing the evaporator itself. This project will utilize a “test early, test often” approach, building at least one trial evaporator to guide the design of the final product.

  20. Mechanism of Electrochemical Catalytic Treatment of Phenol Wastewater Catalyzed by Metal Ion Supported on Cation Exchange Resin%苯酚水在离子交换树脂电化学降解中的机理研究

    Institute of Scientific and Technical Information of China (English)

    王莹; 侯党社; 韩莉萍

    2011-01-01

    The electrochemical oxidation of phenol in synthetic wastewater catalyzed by metal ion supported on cation exchange resin has been investigated.It was found that in the process of the phenol oxidation, hydroxyl radicals and Fe were all attribute to the phenol oxidation.%本文以负载金属的离子交换树脂为催化剂,采用电化学降解的方法研究了苯酚水的降解机理.研究表明苯酚水在离子交换树脂电化学降解中可能是由羟基自由基、金属氧化物、金属离子、电絮凝等协同作用下进行降解.

  1. Brine disposal process for Morcinek coal mine

    Energy Technology Data Exchange (ETDEWEB)

    Tait, J.H. [Aquatech Services, Inc., Citrus Heights, CA (United States)

    1995-04-01

    This paper describes the work to develop a commercial brine disposal process for the Morcinek mine, located 45 km south of the city of Katowice in Poland. Currently, brine is discharged into the Odra river and methane from the mine is released into the atmosphere. The process would use the released methane and convert a large percentage of the brine into potable water for commercial use. Thus, the proposed process has two environmental benefits. The brine salinity is about 31,100 ppm. Major brine components are Na (10,300 ppm), Ca (1,170 ppm), Mg (460 ppm), Cl (18,500 ppm) and SO{sub 4}{sup 2-} (252 ppm). Present in smaller amounts are K, S, Sr, B, Ba and NO{sub 3}. The process integrates a reverse osmosis (RO) unit and a submerged combustion evaporator. Extensive studies made at the Lawrence Livermore National Laboratory established the pretreatment method of the brine before it enters the RO unit. Without adequate pretreatment, mineral phases in the brine would become super-saturated and would precipitate in the RO unit. The pretreatment consists of first adding sodium carbonate to increase both the pH and the carbonate concentration of the brine. This addition causes precipitation of carbonate solids containing Ca, Mg, Sr, and Ba. After filtration of these precipitates, the fluid is acidified with HCl to prevent precipitation in the RO unit as the brine increases in salinity.

  2. Origin of the yellow brine and the black brine in Sichuan Basin

    International Nuclear Information System (INIS)

    The spring water, geothermal water and Cretaceous brine in the outer zone of the Sichuan Basin has the Craig relationship, and they are cycling waters. The brine in the inner zone is mainly metasedimentary water. A basic feature of them is poor in 2H, but rich in 18O. The δD-values of the yellow brine in Jurassic and Upper Triassic aquifer of continental facies varies from -62.25 to -22.4, and the δ18O-values are -6.72 - +6.02. The δD-values of the black brine in marine aquifer (T2,T1,P,C,O and so on) varies from -49 to -25.1, and the 18O values are +3.89 - +6.14. The δD of yellow brine is similar to that of meteoric water, and the δD of the black brine is around that of crystallization water expelled from gypsum by anhydritization. Increases of salinity in Jurassic yellow brine result primarily from the evapotranspiration process. The salinity in Upper Triassic yellow brine in Aa sub-area originated from underlying rock salt which was leached by paleometeoric water. Triassic black brine derived from the mixing of the crystallization water leached from rock salt with the residual sea water after salt crystallization. In Zhigong, the composition of yellow brine has mainly been changed by the mixing of the yellow brine with the black brine. (author). 2 refs, 2 figs, 2 tabs

  3. Mercury(II) removal from aqueous solutions and wastewaters using a novel cation exchanger derived from coconut coir pith and its recovery

    International Nuclear Information System (INIS)

    A new adsorbent (PGCP-COOH) having carboxylate functional group at the chain end was synthesized by grafting poly(hydroxyethylmethacrylate) onto coconut coir pith, CP (a coir industry-based lignocellulosic residue), using potassium peroxydisulphate as an initiator and in the presence of N,N'-methylenebisacrylamide as a cross-linking agent. The adsorbent was characterized with the help of infrared spectroscopy, powder X-ray diffraction, scanning electron microscopy, and potentiometric titrations. The ability of PGCP-COOH to remove Hg(II) from aqueous solutions was assessed using batch adsorption technique under kinetic and equilibrium conditions. Adsorbent exhibits very high adsorption potential for Hg(II) and more than 99.0% removal was achieved in the pH range 5.5-8.0. Adsorption process was found to follow first-order-reversible kinetics. An increase of ionic strength of the medium caused a decrease in metal removal, indicating the occurrence of outer-sphere surface complex mechanism. The equilibrium data were fitted well by the Freundlich isotherm model (R2 = 0.99; χ2 1.81). The removal efficiency was tested using chlor-alkali industry wastewater. Adsorption isotherm experiments were also conducted for comparison using a commercial carboxylate-functionalized ion exchanger, Ceralite IRC-50. Regeneration experiments were tried for four cycles and results indicate a capacity loss of <9.0%

  4. On the physico-chemical characteristics of brines

    Digital Repository Service at National Institute of Oceanography (India)

    Shirodkar, P.V.; Rao, P.V.S.S.D.P.; Singbal, S.Y.S.

    Analyses of the natural brines form the salt lakes, salt pans and the artificial brines obtained after the solar desalination of seawater respectively, showed wide differences in their physico-chemical characteristics. The natural brines are markEd...

  5. REFUSE OF FERMENTATION BRINES IN THE CUCUMBER PICKLING INDUSTRY

    Science.gov (United States)

    The project evaluated on a commercial scale the technological and economic feasibility of recycling spent cucumber fermentation brine. Two brine treatment procedures, heat treatment and chemical treatment, were used. The results showed that brine recycling was practical on a comm...

  6. A Novel Ion Exchange System to Purify Mixed ISS Waste Water Brines for Chemical Production and Enhanced Water Recovery

    Science.gov (United States)

    Lunn, Griffin; Spencer, LaShelle; Ruby, Anna-Maria; McCaskill, Andrew

    2014-01-01

    Current International Space Station water recovery regimes produce a sizable portion of waste water brine. This brine is highly toxic and water recovery is poor: a highly wasteful proposition. With new biological techniques that do not require waste water chemical pretreatment, the resulting brine would be chromium-free and nitrate rich which can allow possible fertilizer recovery for future plant systems. Using a system of ion exchange resins we can remove hardness, sulfate, phosphate and nitrate from these brines to leave only sodium and potassium chloride. At this point modern chlor-alkali cells can be utilized to produce a low salt stream as well as an acid and base stream. The first stream can be used to gain higher water recovery through recycle to the water separation stage while the last two streams can be used to regenerate the ion exchange beds used here, as well as other ion exchange beds in the ISS. Conveniently these waste products from ion exchange regeneration would be suitable as plant fertilizer. In this report we go over the performance of state of the art resins designed for high selectivity of target ions under brine conditions. Using ersatz ISS waste water we can evaluate the performance of specific resins and calculate mass balances to determine resin effectiveness and process viability. If this system is feasible then we will be one step closer to closed loop environmental control and life support systems (ECLSS) for current or future applications.

  7. Influência da matéria orgânica na capacidade de troca de cations do solo Cation-exchange capacity of the organic fraction of soils

    Directory of Open Access Journals (Sweden)

    F. da Costa Verdade

    1956-01-01

    . The cation-exchange capacity and other data on these soils show that the organic fraction must play an important role in the cation-exchange process. The study of the adsorptive capacity of the organic matter was done by destruction of the organic fraction of the soil by 12% hydrogen peroxide. For heavy textured soils the results show that the organic fraction most resistant to oxidation had a higher cation-exchange capacity than the portion first oxidized. For sandy soils all organic fractions had the same magnitude in the base adsorbing power. It was observed that the organic matter seems to inhibit the base-exchange capacity of the mineral fraction. Plotting the percentage of cation-exchange capacity of the organic fraction against the percentage of organic carbon in the soil, a curve is determined which shows the inhibition phenomenon. The results were rather scattered and the experiments are now being repeated to elucidate these observations. The organic cation-exchange capacity of soils in São Paulo is 30-40% for fine textured soils and 50-60% for sandy soils. Since most of the farming land in São Paulo belongs to the sandy soil group called Bauru, the problem of maintaining or increasing the fertility of these soils is dependent on their organic matter content.

  8. Chemically regenerable redox fuel cell and method of operating the same

    International Nuclear Information System (INIS)

    A chemically regenerable redox fuel cell is disclosed. This fuel cell is one in which the oxidant is oxygen and the fuel is hydrogen. A catholyte solution is used. The catholyte solution is one which is reoxidized from a reduced state to an oxidized state by direct exposure of the catholyte solution to oxygen. An anolyte solution is also used. This anolyte solution is one which is reduced from an oxidized state to a reduced state by direct exposure of the catholyte solution to hydrogen. Structure is provided for containing in separate containers the catholyte solution and the anolyte solution, and for providing oxygen to the catholyte solution and hydrogen to the anolyte solution. A suitable cationic exchange membrane is housed in a housing and provided with volumes on opposite sides of the membrane for the catholyte solution and anolyte solution so that the necessary exchanges may take place to form the redox cell. All necessary plumbing and electrical systems are provided to supply the catholyte and anolyte solutions to the cationic exchange membrane and to obtain from the exchange which takes place at the membrane the electrical potential generated

  9. Effect of Brine Solution Containing Ginger Extracts on the Properties of Egyptian White Brined Cheese

    Directory of Open Access Journals (Sweden)

    M. Abd El-Aziz

    2015-01-01

    Full Text Available The present study aims to investigate the physico-chemicals properties of white cheese pickled in brine solution containing ginger extracts. After cows milk coagulation and whey drained, fresh white cheese block was cut and divided into 3 equal portions. The first portion covered with 16.0% brine aqueous ginger extract and the second portion was covered with 16.0% brine ethanol ginger extract. The later was covered with 16.0% plain brine serves as a control. All white brined cheese treatments were stored at 5±2°C for the ripening period of 60 days. The results revealed that brine solution containing aqueous ginger extract or ethanol ginger extract enhances the growth of starter culture, protein proteolysis (WSN/TN, total volatile fatty acids (TVFAs, oxidative stability (reduced TBA and sensory properties of white brined cheese compared with control cheese. In addition, brine solution containing aqueous ginger extract or ethanol ginger extract caused an increase in reddish and yellowish color degree and decrease in hardness of white cheese. However, most of these observations were more pronounced in white cheese pickled in brine aqueous ginger extract compared with that pickled in brine ethanol ginger extract; the differences were not significant.

  10. The Brine Shrimp's Butterfly Stroke

    CERN Document Server

    Johnson, Brennan; Dasi, Lakshmi Prasad

    2011-01-01

    We investigate the fluid dynamics of brine shrimp larvae swimming in this gallery of fluid motion video. Time resolved particle image velocimetry was performed using nano-particles as seeding material to measure the time dependent velocity and vorticity fields. The Reynolds number of the flow was roughly 8 and the Womerseley number (ratio of periodic forcing to viscous forcing) was about 5. Vorticity dynamics reveals the formation of a vortex ring structure at the tip of each arm at the beginning of the power stroke. This two vortex system evolves dramatically with time as the stroke progresses. The outer circulation is noted to weaken while the inner circulation strengthens over the power stroke. The gaining strength of the inner vortex correlates with the acceleration and forward movement of the larvae.

  11. Zooplankton at deep Red Sea brine pools

    KAUST Repository

    Kaartvedt, Stein

    2016-03-02

    The deep-sea anoxic brines of the Red Sea comprise unique, complex and extreme habitats. These environments are too harsh for metazoans, while the brine–seawater interface harbors dense microbial populations. We investigated the adjacent pelagic fauna at two brine pools using net tows, video records from a remotely operated vehicle and submerged echosounders. Waters just above the brine pool of Atlantis II Deep (2000 m depth) appeared depleted of macrofauna. In contrast, the fauna appeared to be enriched at the Kebrit Deep brine–seawater interface (1466 m).

  12. Ice Control with Brine on Highways

    DEFF Research Database (Denmark)

    Bolet, Lars

    of interpreting this information. The improvements gained by the county of Funen were mainly due to the use of technologies (brine spreading with nozzles) giving a more precise spread pattern than the traditional gritting of pre-wetted salt. Major challenges in the process have been to verify the higher quality...... of the nozzles spread pattern, to ensure maximum utilization of volume of brine carried by the spreading vehicles and to control the mixing of brine without getting stratification in the mixture. Moreover, of course, to ensure political approval of abandoning a well-served technology and to organize...

  13. Simultaneous determination of sub μg·g-1 levels of nine impurities in high purity iron by horizontal cation exchange resin mini-column and ICP-atomic emission spectrometry

    International Nuclear Information System (INIS)

    Inductively coupled plasma-atomic emission spectrometry (ICP-AES) has been applied to the simultaneous determination of trace impurities in high purity iron after simultaneous separation. Sub μg·g-1 levels of Ca, Cd, Co, Cu, Mg, Mn, Ni, Pb and Zn in high purity iron which had been dissolved in hydrofluoric acid and hydrogen peroxide were separated from the iron matrix using a horizontal cation exchange resin mini-column. Flow rates and flow directions of solutions through the mini-column were controlled by a peristaltic pump. Adsorbed elements on the resin mini-column were rapidly eluted using a reverse flow of the eluant against the flow for the adsorption. The eluted elements were determined by ICP-AES using an internal standard method and good results were obtained. A 100-fold enrichment of analytes was obtained with this preconcentration system using 1 g of the sample in comparison with an ordinary sample solution in which 0.5 g of the sample was dissolved in 100 cm3 without separation. (author)

  14. Nearly 1000 Protein Identifications from 50 ng of Xenopus laevis Zygote Homogenate Using Online Sample Preparation on a Strong Cation Exchange Monolith Based Microreactor Coupled with Capillary Zone Electrophoresis.

    Science.gov (United States)

    Zhang, Zhenbin; Sun, Liangliang; Zhu, Guijie; Cox, Olivia F; Huber, Paul W; Dovichi, Norman J

    2016-01-01

    A sulfonate-silica hybrid strong cation exchange monolith microreactor was synthesized and coupled to a linear polyacrylamide coated capillary for online sample preparation and capillary zone electrophoresis-tandem mass spectrometry (CZE-MS/MS) bottom-up proteomic analysis. The protein sample was loaded onto the microreactor in an acidic buffer. After online reduction, alkylation, and digestion with trypsin, the digests were eluted with 200 mM ammonium bicarbonate at pH 8.2 for CZE-MS/MS analysis using 1 M acetic acid as the background electrolyte. This combination of basic elution and acidic background electrolytes results in both sample stacking and formation of a dynamic pH junction. 369 protein groups and 1274 peptides were identified from 50 ng of Xenopus laevis zygote homogenate, which is comparable with an offline sample preparation method, but the time required for sample preparation was decreased from over 24 h to less than 40 min. Dramatically improved performance was produced by coupling the reactor to a longer separation capillary (∼100 cm) and a Q Exactive HF mass spectrometer. 975 protein groups and 3749 peptides were identified from 50 ng of Xenopus protein using the online sample preparation method. PMID:26670623

  15. Development and validation of a UHPLC-MS/MS assay for colistin methanesulphonate (CMS) and colistin in human plasma and urine using weak-cation exchange solid-phase extraction.

    Science.gov (United States)

    Zhao, Miao; Wu, Xiao-Jie; Fan, Ya-Xin; Guo, Bei-Ning; Zhang, Jing

    2016-05-30

    A rapid ultra high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) assay method was developed for determination of CMS and formed colistin in human plasma and urine. After extraction on a 96-well SPE Supra-Clean Weak Cation Exchange (WCX) plate, the eluents were mixed and injected into the UHPLC-MS/MS system directly. A Phonomenex Kinetex XB-C18 analytical column was employed with a mobile phase consisting of solution "A" (acetonitrile:methanol, 1:1, v/v) and solution "B" (0.1% formic acid in water, v/v). The flow rate was 0.4mL/min with gradient elution over 3.5min. Ions were detected in ESI positive ion mode and the precursor-product ion pairs were m/z 390.7/101.3 for colistin A, m/z 386.0/101.2 for colistin B, and m/z 402.3/101.2 for polymyxin B1 (IS), respectively. The lower limit of quantification (LLOQ) was 0.0130 and 0.0251mg/L for colistin A and colistin B in both plasma and urine with accuracy (relative error, %)colistin, which offers a highly efficient tool for the analysis of a large number of clinical samples as well as routine therapeutic drug monitoring. PMID:26970986

  16. Recovery of soil pH, cation-exchange capacity and the saturation of exchange sites from stemflow-induced soil acidification in three Swedish beech (Fagus sylvatica L.) forests

    International Nuclear Information System (INIS)

    Stemflow water acidifies the soil in beech stands impacted by atmospheric deposition. To investigate whether the soil recovers from acidification, stemflow was experimentally removed. A horizon material was sampled at a distance of 10-250 cm from the stems. Before the onset of the experiment, there were stemflow-induced gradients in the saturation of exchange sites with K+, H+ and Na+ that were larger near the stems, while the pHKCl, the cation-exchange capacity, and the saturation with Ca2+, Mg2+ and Mn2+ were smaller. After 8 yrs of recovery, the pHKCl and the saturation with Ca2+ and Mg2+ had increased close to the stems, while the saturation with Na+, H+, Mn2+ and Fe2+ and the C/N ratio had decreased. With some exceptions, e.g. base saturation, the recovery was not complete after 8 yrs. Soil far from stems had also changed similarly, probably because of the ongoing decrease in overall deposition in southern Sweden

  17. Brine Dewatering Using Ultrasonic Nebulization Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Recovery of water from brine is critically important for future manned space exploration. Resupply of water is prohibitively costly for such extended missions....

  18. Brine Dewatering Using Ultrasonic Nebulization Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Recovery of water from brine is critically important for manned space exploration. Resupply of water is prohibitively costly for extended missions. It is...

  19. Echinoderms as indicators of brine discharge impacts

    OpenAIRE

    Fernández-Torquemada, Yolanda; González-Correa, José Miguel; Sánchez-Lizaso, José Luis

    2013-01-01

    Echinoderms are osmoconformer organisms and are expected to be very sensitive to brine discharges. The objective of this study is to examine the use of echinoderms as early warning indicators of the impact of brine discharges and its application in the management of desalination discharges. We sampled using visual census along transect lines, for nine consecutive years and in three different stations, i.e. before the seawater reverse osmosis desalination plant began operating and thereafter. ...

  20. Comparison of brines relevant to nuclear waste experimentation

    International Nuclear Information System (INIS)

    The ionic compositions of 18 brines used in nuclear waste-related laboratory tests or obtained from field tests are described and compared. Also described are the origin of each brine, its predominant use for laboratory testing, and its relavancy for future testing. The brines include Brines A and B (Waste Isolation Pilot Plant (WIPP)/generic), Office of Nuclear Waste Isolation (ONWI) Composite Permian Brine P and Equilibrated Permian P No. 2, Battelle Pacific Northwest Laboratory (PNL)-Sandia High-Level Waste (HLW) package interactions test brines (flow and downhole), ERDA-6 brines (flow and downhole), WIPP Inclusions No. 1 and No. 2, Materials Characterization Center (MCC) brine, German quinare Brine Q, US Geological Survey bittern NBT-6a, saturated NaCl (200 and 1000C), and standard seawater

  1. Regeneration of clinoptilolite zeolite used for the ammonium removal

    International Nuclear Information System (INIS)

    The use of zeolites has been increased in the last years with different applications and with a great boom in the environmental area, but a little had been make about the regeneration of such zeolites. The presence of nitrogen-ammonia in water may cause serious pollution problems since it results to be toxic for fishes and other aquatic life forms, also it provokes the algae growing. The natural clinoptilolite contains interchangeable ions such as the sodium (Na+), potassium (K+), magnesium (Mg2+) and calcium (Ca2+) in different proportions depending on the mineral origin When the zeolite is upgraded to its sodium form, the cation exchange capacity and the preference by the nitrogen-ammonia are increased, allowing the reversible process of sorption. In this work it was proposed the regeneration to its sodium form about the ammonia clinoptilolite zeolite. The natural mineral was characterized using the methods such as: X-ray diffraction, Infrared spectroscopy, Thermal gravimetric analysis and surface area. The results show that the ammonium sorption was between 95% and 98.7% such an ambient temperature as a flow back. the zeolite was regenerated approximately from 60% in the first cycle up to 97% in the last cycle at flow back temperature and of 59.2% up to 96.9% at ambient temperature, it was not presented any significant effect which could be attributed to the temperature. During the exchange process, the cations present in the natural zeolite were exchanged with the ammonium ions, this process was not completed due to that retained ammonium quantity was major that of the desorpted ions, what shows that in addition of ion exchange, another type of sorption process exists. (Author)

  2. Brine flow in heated geologic salt.

    Energy Technology Data Exchange (ETDEWEB)

    Kuhlman, Kristopher L.; Malama, Bwalya

    2013-03-01

    This report is a summary of the physical processes, primary governing equations, solution approaches, and historic testing related to brine migration in geologic salt. Although most information presented in this report is not new, we synthesize a large amount of material scattered across dozens of laboratory reports, journal papers, conference proceedings, and textbooks. We present a mathematical description of the governing brine flow mechanisms in geologic salt. We outline the general coupled thermal, multi-phase hydrologic, and mechanical processes. We derive these processes' governing equations, which can be used to predict brine flow. These equations are valid under a wide variety of conditions applicable to radioactive waste disposal in rooms and boreholes excavated into geologic salt.

  3. BIOCHEMICAL PROCESSES FOR GEOTHERMAL BRINE TREATMENT

    Energy Technology Data Exchange (ETDEWEB)

    PREMUZIC,E.T.; LIN,M.S.; BOHENEK,M.; JOSHI-TOPE,G.; ZHOU,W.; SHELENKOVA,L.; WILKE,R.

    1998-09-20

    As part of the DOE Geothermal Energy Program, BNL's Advanced Biochemical Processes for Geothermal Brines (ABPGB) project is aimed at the development of cost-efficient and environmentally acceptable technologies for the disposal of geothermal wastes. Extensive chemical studies of high and low salinity brines and precipitates have indicated that in addition to trace quantities of regulated substances, e.g., toxic metals such as arsenic and mercury, there are significant concentrations of valuable metals, including gold, silver and platinum. Further chemical and physical studies of the silica product have also shown that the produced silica is a valuable material with commercial potential. A combined biochemical and chemical technology is being developed which (1) solubilizes, separates, and removes environmentally regulated constituents in geothermal precipitates and brines (2) generates an amorphous silica product which may be used as feedstock for the production of revenue generating materials, (3) recover economically valuable trace metals and salts. Geothermal power resources which utilize low salinity brines and use the Stretford process for hydrogen sulfide abatement generate a contaminated sulfur cake. Combined technology converts such sulfur to a commercial grade sulfur, suitable for agricultural use. The R and D activities at BNL are conducted jointly with industrial parties in an effort focused on field applications.

  4. Biochemical processes for geothermal brine treatment

    Energy Technology Data Exchange (ETDEWEB)

    Premuzic, E.T.; Lin, M.S.; Bohenek, M.; Joshi-Tope, G.; Zhou, W.; Shelenkova, L.; Wilke, R.

    1998-08-01

    As part of the DOE Geothermal Energy Program, BNL`s Advanced Biochemical Processes for Geothermal Brines (ABPGB) project is aimed at the development of cost-efficient and environmentally acceptable technologies for the disposal of geothermal wastes. Extensive chemical studies of high and low salinity brines and precipitates have indicated that in addition to trace quantities of regulated substances, e.g., toxic metals such as arsenic and mercury, there are significant concentrations of valuable metals, including gold, silver and platinum. Further chemical and physical studies of the silica product have also shown that the produced silica is a valuable material with commercial potential. A combined biochemical and chemical technology is being developed which (1) solubilizes, separates, and removes environmentally regulated constituents in geothermal precipitates and brines, (2) generates an amorphous silica product which may be used as feedstock for the production of revenue generating materials, (3) recover economically valuable trace metals and salts. Geothermal power resources which utilize low salinity brines and use the Stretford process for hydrogen sulfide abatement generate a contaminated sulfur cake. Combined technology converts such sulfur to a commercial grade sulfur, suitable for agricultural use. The R and D activities at BNL are conducted jointly with industrial parties in an effort focused on field applications.

  5. Calcite solubility in simulated geothermal brines

    Energy Technology Data Exchange (ETDEWEB)

    Pool, K.H.; Raney, P.J.; Shannon, D.W.

    1987-02-01

    The deposition of scale on geothermal piping surfaces has been recognized as a cause of increased pressure drop and diminished fluid flow. The two most common scales encountered in the geothermal energy field are silica and calcite. The main purpose of this study was to obtain accurate, reliable calcite solubility data in brines similar to natural geothermal brines over the temperature range of most known exploitable geothermal resources. In addition, geothermal fluid equilibrium modeling efforts and data bases can be refined and fine-turned with respect to the commercially important calcite-geothermal fluid stability problem with these data. The effect of sodium chloride and sodium bicarbonate on the solubility of CaCO/sub 3/ (calcite) in high temperature solutions was measured over the 100 to 300/sup 0/C temperature range. The brines studied contained 0 to 5 wt % NaCl, 0 to 5 mM NaHCO/sub 3/, and 0.003 to 0.1 M CO/sub 2/. The data detailing calcite solubility at various temperatures are presented in tabular, graphical, and regression-equation form for each brine composition tested.

  6. Rheological Properties of Silica Nanoparticles in Brine and Brine-Surfactant Systems

    Science.gov (United States)

    Pales, Ashley; Kinsey, Erin; Li, Chunyan; Mu, Linlin; Bai, Lingyun; Clifford, Heather; Darnault, Christophe

    2016-04-01

    Rheological Properties of Silica Nanoparticles in Brine and Brine-Surfactant Systems Ashley R. Pales, Erin Kinsey, Chunyan Li, Linlin Mu, Lingyun Bai, Heather Clifford, and Christophe J. G. Darnault Department of Environmental Engineering and Earth Sciences, Laboratory of Hydrogeoscience and Biological Engineering, L.G. Rich Environmental Laboratory, Clemson University, Clemson, SC, USA Nanofluids are suspensions of nanometer sized particles in any fluid base, where the nanoparticles effect the properties of the fluid base. Commonly, nanofluids are water based, however, other bases such as ethylene-glycol, glycerol, and propylene-glycol, have been researched to understand the rheological properties of the nanofluids. This work aims to understand the fundamental rheological properties of silica nanoparticles in brine based and brine-surfactant based nanofluids with temperature variations. This was done by using variable weight percent of silica nanoparticles from 0.001% to 0.1%. Five percent brine was used to create the brine based nanofluids; and 5% brine with 2CMC of Tween 20 nonionic surfactant (Sigma-Aldrich) was used to create the brine-surfactant nanofluid. Rheological behaviors, such as shear rate, shear stress, and viscosity, were compared between these nanofluids at 20C and at 60C across the varied nanoparticle wt%. The goal of this work is to provide a fundamental basis for future applied testing for enhanced oil recovery. It is hypothesized that the addition of surfactant will have a positive impact on nanofluid properties that will be useful for enhance oil recovery. Differences have been observed in preliminary data analysis of the rheological properties between these two nanofluids indicating that the surfactant is having the hypothesized effect.

  7. Mirabilite solubility in equilibrium sea ice brines

    Science.gov (United States)

    Butler, Benjamin Miles; Papadimitriou, Stathys; Santoro, Anna; Kennedy, Hilary

    2016-06-01

    The sea ice microstructure is permeated by brine channels and pockets that contain concentrated seawater-derived brine. Cooling the sea ice results in further formation of pure ice within these pockets as thermal equilibrium is attained, resulting in a smaller volume of increasingly concentrated residual brine. The coupled changes in temperature and ionic composition result in supersaturation of the brine with respect to mirabilite (Na2SO4·10H2O) at temperatures below -6.38 °C, which consequently precipitates within the sea ice microstructure. Here, mirabilite solubility in natural and synthetic seawater derived brines, representative of sea ice at thermal equilibrium, has been measured in laboratory experiments between 0.2 and -20.6 °C, and hence we present a detailed examination of mirabilite dynamics within the sea ice system. Below -6.38 °C mirabilite displays particularly large changes in solubility as the temperature decreases, and by -20.6 °C its precipitation results in 12.90% and 91.97% reductions in the total dissolved Na+ and SO42- concentrations respectively, compared to that of conservative seawater concentration. Such large non-conservative changes in brine composition could potentially impact upon the measurement of sea ice brine salinity and pH, whilst the altered osmotic conditions may create additional challenges for the sympagic organisms that inhabit the sea ice system. At temperatures above -6.38 °C, mirabilite again displays large changes in solubility that likely aid in impeding its identification in field samples of sea ice. Our solubility measurements display excellent agreement with that of the FREZCHEM model, which was therefore used to supplement our measurements to colder temperatures. Measured and modelled solubility data were incorporated into a 1D model for the growth of first-year Arctic sea ice. Model results ultimately suggest that mirabilite has a near ubiquitous presence in much of the sea ice on Earth, and illustrate the

  8. Novel Regenerated Solvent Extraction Processes for the Recovery of Carboxylic Acids or Ammonia from Aqueous Solutions Part I. Regeneration of Amine-Carboxylic Acid Extracts

    Energy Technology Data Exchange (ETDEWEB)

    Poole, L.J.; King, C.J.

    1990-03-01

    Two novel regenerated solvent extraction processes are examined. The first process has the potential to reduce the energy costs inherent in the recovery of low-volatility carboxylic acids from dilute aqueous solutions. The second process has the potential for reducing the energy costs required for separate recovery of ammonia and acid gases (e.g. CO{sub 2} and H{sub 2}S) from industrial sour waters. The recovery of carboxylic acids from dilute aqueous solution can be achieved by extraction with tertiary amines. An approach for regeneration and product recovery from such extracts is to back-extract the carboxylic acid with a water-soluble, volatile tertiary amine, such as trimethylamine. The resulting trimethylammonium carboxylate solution can be concentrated and thermally decomposed, yielding the product acid and the volatile amine for recycle. Experimental work was performed with lactic acid, succinic acid, and fumaric acid. Equilibrium data show near-stoichiometric recovery of the carboxylic acids from an organic solution of Alamine 336 into aqueous solutions of trimethylamine. For fumaric and succinic acids, partial evaporation of the aqueous back extract decomposes the carboxylate and yields the acid product in crystalline form. The decomposition of aqueous solutions of trimethylammonium lactates was not carried out to completion, due to the high water solubility of lactic acid and the tendency of the acid to self-associate. The separate recovery of ammonia and acid gases from sour waters can be achieved by combining steam-stripping of the acid gases with simultaneous removal of ammonia by extraction with a liquid cation exchanger. The use of di-2,4,4-trimethylpentyl phosphinic acid as the liquid cation exchanger is explored in this work. Batch extraction experiments were carried out to measure the equilibrium distribution ratio of ammonia between an aqueous buffer solution and an organic solution of the phosphinic acid (0.2N) in Norpar 12. The concentration

  9. Expected brine movement at potential nuclear waste repository salt sites

    Energy Technology Data Exchange (ETDEWEB)

    McCauley, V.S.; Raines, G.E.

    1987-08-01

    The BRINEMIG brine migration code predicts rates and quantities of brine migration to a waste package emplaced in a high-level nuclear waste repository in salt. The BRINEMIG code is an explicit time-marching finite-difference code that solves a mass balance equation and uses the Jenks equation to predict velocities of brine migration. Predictions were made for the seven potentially acceptable salt sites under consideration as locations for the first US high-level nuclear waste repository. Predicted total quantities of accumulated brine were on the order of 1 m/sup 3/ brine per waste package or less. Less brine accumulation is expected at domal salt sites because of the lower initial moisture contents relative to bedded salt sites. Less total accumulation of brine is predicted for spent fuel than for commercial high-level waste because of the lower temperatures generated by spent fuel. 11 refs., 36 figs., 29 tabs.

  10. Geophysical and geochemical signatures of Gulf of Mexico seafloor brines

    Directory of Open Access Journals (Sweden)

    S. B. Joye

    2005-05-01

    Full Text Available Geophysical, temperature, and discrete depth-stratified geochemical data illustrate differences between an actively venting mud volcano and a relatively quiescent brine pool in the Gulf of Mexico along the continental slope. Geophysical data, including laser-line scan mosaics and sub-bottom profiles, document the dynamic nature of both environments. Temperature profiles, obtained by lowering a CTD into the brine fluid, show that the venting brine was at least 10°C warmer than the bottom water. At the brine pool, two thermoclines were observed, one directly below the brine-seawater interface and a second about one meter below the first. At the mud volcano, substantial temperature variability was observed, with the core brine temperature being either slightly (~2°C in 1997 or substantially (19°C in 1998 elevated above bottom water temperature. Geochemical samples were obtained using a device called the "brine trapper" and concentrations of dissolved gases, major ions and nutrients were determined using standard techniques. Both brines contained about four times as much salt as seawater and steep concentration gradients of dissolved ions and nutrients versus brine depth were apparent. Differences in the concentrations of calcium, magnesium and potassium between the two brine fluids suggests that the fluids are derived from different sources or that brine-sediment reactions are more important at the mud volcano than the brine pool. Substantial concentrations of methane and ammonium were observed in both brines, suggesting that fluids expelled from deep ocean brines are important sources of methane and dissolved inorganic nitrogen to the surrounding environment.

  11. Evolution of hydrologic systems and brine geochemistry in a deforming salt medium: Data from WIPP brine seeps

    Energy Technology Data Exchange (ETDEWEB)

    Deal, D.E. (I. T. Corp., Carlsbad, NM (USA)); Roggenthen, W.M. (South Dakota School of Mines and Technology, Rapid City, SD (USA). Dept. of Geology and Geological Engineering)

    1991-01-01

    The Brine Sampling and Evaluation Program (BSEP) is a formalized continuation of studies that began in 1982 as part of the Site Validation Program. The program was established in 1985. The mission was to document and investigate the origins, hydraulic characteristics, extent, and composition of brine occurrences in the Permian Salado Formation and the seepage of that brine into the WIPP excavations. This document focuses on the cumulative data obtained from the BSEP. The overall activities of the BSEP described and quantified the brine. It includes documentation and study of brine inflow into boreholes in the facility. The BSEP investigated the occurrence and development of brine weeps, crusts, and brine geochemistry. The presence of salt-tolerant bacteria in the workings was recorded and their possible interactions with experiments and operations, was assessed. The formation properties associated with the occurrence of brine was characterized. The determination of formation properties included the water content of various geologic units, direct examination of these units in boreholes using a video camera system, and measurement of electrical properties relatable to the brine contents. Modeling examined the interaction of salt deformation near the workings and the flow of brine through the deforming rocks. 34 refs.

  12. Evolution of hydrologic systems and brine geochemistry in a deforming salt medium: Data from WIPP brine seeps

    International Nuclear Information System (INIS)

    The Brine Sampling and Evaluation Program (BSEP) is a formalized continuation of studies that began in 1982 as part of the Site Validation Program. The program was established in 1985. The mission was to document and investigate the origins, hydraulic characteristics, extent, and composition of brine occurrences in the Permian Salado Formation and the seepage of that brine into the WIPP excavations. This document focuses on the cumulative data obtained from the BSEP. The overall activities of the BSEP described and quantified the brine. It includes documentation and study of brine inflow into boreholes in the facility. The BSEP investigated the occurrence and development of brine weeps, crusts, and brine geochemistry. The presence of salt-tolerant bacteria in the workings was recorded and their possible interactions with experiments and operations, was assessed. The formation properties associated with the occurrence of brine was characterized. The determination of formation properties included the water content of various geologic units, direct examination of these units in boreholes using a video camera system, and measurement of electrical properties relatable to the brine contents. Modeling examined the interaction of salt deformation near the workings and the flow of brine through the deforming rocks. 34 refs

  13. Desulfurization sorbent regeneration

    Science.gov (United States)

    Jalan, V.M.; Frost, D.G.

    1982-07-07

    A spent solid sorbent resulting from the removal of hydrogen sulfide from a fuel gas flow is regenerated with a steam-air mixture. The mixture of steam and air may also include additional nitrogen or carbon dioxide. The gas mixture contacts the spent sorbent containing metal sulfide at a temperature above 500/sup 0/C to regenerate the sulfide to metal oxide or carbonate. Various metal species including the period four transition metals and the lanthanides are suitable sorbents that may be regenerated by this method. In addition, the introduction of carbon dioxide gas permits carbonates such as those of strontium, barium and calcium to be regenerated. The steam permits regeneration of spent sorbent without formation of metal sulfate. Moreover, the regeneration will proceed with low oxygen concentrations and will occur without the increase in temperature to minimize the risk of sintering and densification of the sorbent. This method may be used for high-temperature fuel cells.

  14. Stirling convertor regenerators

    CERN Document Server

    Ibrahim, Mounir B

    2011-01-01

    Stirling Convertor Regenerators addresses the latest developments and future possibilities in the science and practical application of Stirling engine regenerators and technology. Written by experts in the vanguard of alternative energy, this invaluable resource presents integral scientific details and design concepts associated with Stirling converter regenerators. Content is reinforced with novel insights and remarkable firsthand experience that the authors and their colleagues acquired while working at the National Aeronautics and Space Administration (NASA) and other leading organizations.

  15. OUT Success Stories: Chemical Treatments for Geothermal Brines

    International Nuclear Information System (INIS)

    DOE research helped develop the large, untapped geothermal resource beneath the Salton Sea in California's Imperial Valley. The very hot brines under high pressure make them excellent for electric power production. The brines are very corrosive and contain high concentrations of dissolved silica. DOE worked with San Diego Gas and Electric Company to find a solution to the silica-scaling problem. This innovative brine treatment eliminated scaling and made possible the development of the Salton Sea geothermal resource

  16. Geophysical and geochemical signatures of Gulf of Mexico seafloor brines

    OpenAIRE

    Joye, S. B.; Macdonald, I. R.; Montoya, J. P.; Peccini, M.

    2005-01-01

    Geophysical, temperature, and discrete depth-stratified geochemical data illustrate differences between an actively venting mud volcano and a relatively quiescent brine pool in the Gulf of Mexico along the continental slope. Geophysical data, including laser-line scan mosaics and sub-bottom profiles, document the dynamic nature of both environments. Temperature profiles, obtained by lowering a CTD into the brine fluid, show that the venting brine was at least 10°C warmer than the bottom w...

  17. Geophysical and geochemical signatures of Gulf of Mexico seafloor brines

    Directory of Open Access Journals (Sweden)

    S. B. Joye

    2005-01-01

    Full Text Available Geophysical, temperature, and discrete depth-stratified geochemical data illustrate differences between an actively venting mud volcano and a relatively quiescent brine pool in the Gulf of Mexico along the continental slope. Geophysical data, including laser-line scan mosaics and sub-bottom profiles, document the dynamic nature of both environments. Temperature profiles, obtained by lowering a CTD into the brine fluid, show that the venting brine was at least 10°C warmer than the bottom water. At the brine pool, thermal stratification was observed and only small differences in stratification were documented between three sampling times (1991, 1997 and 1998. In contrast, at the mud volcano, substantial temperature variability was observed, with the core brine temperature being slightly higher than bottom water (by 2°C in 1997 but substantially higher than bottom water (by 19°C in 1998. Detailed geochemical samples were obtained in 2002 using a device called the 'brine trapper' and concentrations of dissolved gases, major ions and nutrients were determined. Both brines contained about four times as much salt as seawater and steep concentration gradients of dissolved ions and nutrients versus brine depth were apparent. Differences in the concentrations of calcium, magnesium and potassium between the two brine fluids suggest that the fluids are derived from different sources, have different dilution/mixing histories, or that brine-sediment reactions are more important at the mud volcano. Substantial concentrations of methane, ammonium, and silicate were observed in both brines, suggesting that fluids expelled from deep ocean brines are important sources of these constituents to the surrounding environment.

  18. Evaluation of Brine Processing Technologies for Spacecraft Wastewater

    Science.gov (United States)

    Shaw, Hali L.; Flynn, Michael; Wisniewski, Richard; Lee, Jeffery; Jones, Harry; Delzeit, Lance; Shull, Sarah; Sargusingh, Miriam; Beeler, David; Howard, Jeanie; Howard, Kevin; Harris, Linden; Parodi, Jurek; Kawashima, Brian

    2015-01-01

    Brine drying systems may be used in spaceflight. There are several advantages to using brine processing technologies for long-duration human missions including a reduction in resupply requirements and achieving high water recovery ratios. The objective of this project was to evaluate four technologies for the drying of spacecraft water recycling system brine byproducts. The technologies tested were NASA's Forward Osmosis Brine Drying (FOBD), Paragon's Ionomer Water Processor (IWP), NASA's Brine Evaporation Bag (BEB) System, and UMPQUA's Ultrasonic Brine Dewatering System (UBDS). The purpose of this work was to evaluate the hardware using feed streams composed of brines similar to those generated on board the International Space Station (ISS) and future exploration missions. The brine formulations used for testing were the ISS Alternate Pretreatment and Solution 2 (Alt Pretreat). The brines were generated using the Wiped-film Rotating-disk (WFRD) evaporator, which is a vapor compression distillation system that is used to simulate the function of the ISS Urine Processor Assembly (UPA). Each system was evaluated based on the results from testing and Equivalent System Mass (ESM) calculations. A Quality Function Deployment (QFD) matrix was also developed as a method to compare the different technologies based on customer and engineering requirements.

  19. Modeling of brine migration in halite

    International Nuclear Information System (INIS)

    Four different models of the migration process have been reviewed to determine their suitability as a working model. While there are several common factors in the models additional factors are included to account for several possible effects. The detail of each model leads to a certain degree of difficulty in applying the model to the problem at hand. One model predicts that inclusions smaller than 0.1 mm dimension probably will not migrate. The other models do not consider size as a factor. Thermal diffusion (Soret effect) is considered insignificant in three models, while in the fourth model it is added to the concentration diffusion term. The following conclusions are made: (1) Temperature is the most significant parameter in all models and must be known as a function of time, and distance from the canister. (2) All four models predict about the same migration velocity for a given set of conditions. For 1000C and 10C/cm thermal gradient, the individual values are 3.0, 4.8, 5.6 and 6.4 mm/y. (3) The diffusion of ions through the brine inclusions is the rate controlling mechanism. (4) The difference between the thermal gradients in the liquid and in the solid should always be considered, and is a function of droplet shape. (5) The model based upon work by Nernst is easiest to use since all necessary parameters are readily available in the literature. However, of the four models is predicts the lowest migration rate. (6) The maximum volume of pure brine accumulated at the canister surface would be less than 20-40 liters in 50 years, for a canister initial thermal power of 3.5 kW. Bitterns would migrate proportionately less volume. A compuber code, BRINE, was developed to make these calculations by means of any of the four models

  20. Power production via North Sea Hot Brines

    International Nuclear Information System (INIS)

    Traditionally the power demand of offshore oil platforms is delivered by on-platform gas turbines. Natural gas to fuel these turbines is usually separated from the produced oil. However, in ageing fields as oil production declines so does the associated gas. Ultimately gas supply becomes insufficient; in order to continue producing fuel is imported at great expense. This study proposes the power demand of a platform could be met or supplemented by an on-platform ORC (organic Rankine cycle ) fuelled by coproduced hot brines. This could extend the operating life of oil platforms and reduce both cost and emissions. The potential power output of an ORC is modelled for fields in the North Sea's Brent Province. Results show 6 fields have the potential to generate more than 10 MW via an organic Rankine cycle fuelled by hot brines, with a maximum of 31 MW predicted for the Ninian field. Analysis of simulations for the Eider field shows that ORC plants can scale to size constraints. The cost of a 10 MW ORC is compared to cost of continued use of gas turbines. Payback times of between 3.09 and 4.53 years are predicted for an ORC, without accounting for greenhouse gas emissions levies. - Highlights: • We model organic Rankine cycles fuelled by hot brines produced in the North Sea. • Organic Rankine cycles could provide all an off-shore platform's power demand. • 6 fields in the Brent province have the potential to produce >10 MW via an ORC system. • Payback time calculated for a 10 MW organic Rankine cycle is 3.09–4.53 years

  1. Consolidation and permeability of salt in brine

    Energy Technology Data Exchange (ETDEWEB)

    Shor, A.J.; Baes, C.F. Jr.; Canonico, C.M.

    1981-07-01

    The consolidation and loss of permeability of salt crystal aggregates, important in assessing the effects of water in salt repositories, has been studied as a function of several variables. The kinetic behavior was similar to that often observed in sintering and suggested the following expression for the time dependence of the void fraction: phi(t) = phi(0) - (A/B)ln(1 + Bt/z(0)/sup 3/), where A and B are rate constants and z(0) is initial average particle size. With brine present, A and phi(0) varied linearly with stress. The initial void fraction was also dependent to some extent on the particle size distribution. The rate of consolidation was most rapid in brine and least rapid in the presence of only air as the fluid. A brine containing 5 m MgCl/sub 2/ showed an intermediate rate, presumably because of the greatly reduced solubility of NaCl. A substantial wall effect was indicated by an observed increase in the void fraction of consolidated columns with distance from the top where the stress was applied and by a dependence of consolidation rate on the column height and radius. The distance through which the stress fell by a factor of phi was estimated to change inversely as the fourth power of the column diameter. With increasing temperature (to 85/sup 0/C), consolidation proceeded somewhat more rapidly and the wall effect was reduced. The permeability of the columns dropped rapidly with consolidation, decreasing with about the sixth power of the void fraction. In general, extrapolation of the results to repository conditions confirms the self-sealing properties of bedded salt as a storage medium for radioactive waste.

  2. Brine Transport Experiments in Granular Salt

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, Amy B. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Boukhalfa, Hakim [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Caporuscio, Florie Andre [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Stauffer, Philip H. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-06-06

    To gain confidence in the predictive capability of numerical models, experimental validation must be performed to ensure that parameters and processes are correctly simulated. The laboratory investigations presented herein aim to address knowledge gaps for heat-generating nuclear waste (HGNW) disposal in bedded salt that remain after examination of prior field and laboratory test data. Primarily, we are interested in better constraining the thermal, hydrological, and physicochemical behavior of brine, water vapor, and salt when moist salt is heated. The target of this work is to use run-of-mine (RoM) salt; however during FY2015 progress was made using high-purity, granular sodium chloride.

  3. Pressure-driven brine migration in a salt repository

    International Nuclear Information System (INIS)

    The traditional view is that salt is the ideal rock for isolation of nuclear waste because it is ''dry'' and probably ''impermeable.'' The existence of salt through geologic time is prima facie evidence of such properties. Experiments and experience at potential salt sites for geologic repositories have indicated that while porosity and permeability of salt are low, the salt may be saturated with brine. If this hypothesis is correct, then it is possible to have brine flow due to pressure differences within the salt. If there is pressure-driven brine migration in salt repositories then it is paramount to know the magnitude of such flow because inward brine flow would affect the corrosion rate of nuclear waste containers and outward brine flow might affect radionuclide transport rates. Brine exists in natural salt as inclusions in salt crystals and in grain boundaries. Brine inclusions in crystals move to nearby grain boundaries when subjected to a temperature gradient, because of temperature-dependent solubility of salt. Brine in grain boundaries moves under the influence of a pressure gradient. When salt is mined to create a waste repository, brine from grain boundaries will migrate into the rooms, tunnels and boreholes because these cavities are at atmospheric pressure. After a heat-emitting waste package is emplaced and backfilled, the heat will impose a temperature gradient in the surrounding salt that will cause inclusions in the nearby salt to migrate to grain boundaries within a few years, adding to the brine that was already present in the grain boundaries. The formulation of brine movement with salt as a thermoelastic porous medium, in the context of the continuum theory of mixtures, has been described. In this report we show the mathematical details and discuss the results predicted by this analysis

  4. Moisture variations in brine-salted pasta filata cheese.

    Science.gov (United States)

    Kindstedt, P S

    2001-01-01

    A study was made of the moisture distribution in brine-salted pasta filata cheese. Brine-salted cheeses usually develop reasonably smooth and predictable gradients of decreasing moisture from center to surface, resulting from outward diffusion of moisture in response to inward diffusion of salt. However, patterns of moisture variation within brine-salted pasta filata cheeses, notably pizza cheese, are more variable and less predictable because of the peculiar conditions that occur when warm cheese is immersed in cold brine. In this study, cold brining resulted in less moisture loss from the cheese surface to the brine. Also it created substantial temperature gradients within the cheese, which persisted after brining and influenced the movement of moisture within the cheese independently of that caused by the inward diffusion of salt. Depending on brining conditions and age, pizza cheese may contain decreasing, increasing, or irregular gradients of moisture from center to surface, which may vary considerably at different locations within a single block. This complicates efforts to obtain representative samples for moisture and composition testing. Dicing the entire block into small (e.g., 1.5 cm) cubes and collecting a composite sample after thorough mixing may serve as a practical sampling approach for manufacturers and users of pizza cheese that have ready access to dicing equipment. PMID:11324629

  5. Research on Purification Process of Vindoline and Catharanthine from Catharanthus roseus by Means of Cation Exchange Resin%阳离子交换树脂纯化长春花中文多灵和长春质碱的工艺优选

    Institute of Scientific and Technical Information of China (English)

    柏道鸣; 周广涛; 代龙

    2012-01-01

    Objective: To select the optimum purifying process of Vindoline and Catharanthine from Catharanthus roseus by means of cation exchange resin. Method: The purifying process of Vindoline and Catharanthine from Catharanthus roseus was performed by cation exchange resin of LSD-001 type, with the solvent of ammonia water, the mixture of ammonia water and ethanol, acid water, the mixture of acid water and ethanol, the mixture of sodium chloride and ethanol, and the content of two alkaloids were determined to choose the optimal technological parameters. Result: The ideal concentration of solvent was: with 80% ethanol ( containing 1% sodium chloride ) eluent elution, two alkaloids eluting attained the highest rate. Conclusion : The purification process has well effect.It can be used for purifying Vindoline and Catharanthine from Catharanthus roseus by means of cation exchange resin.%目的:考察阳离子交换树脂不同洗脱溶剂纯化长春花中文多灵和长春质碱的效果,优选最佳工艺条件.方法:采用LSD-001大孔型阳离子交换树脂对长春花中文多灵和长春质碱进行纯化,以两种生物碱含量为指标,考察以氨水、氨性乙醇、酸水、酸性乙醇、盐醇为洗脱剂纯化两种生物碱的效果.结果:经过优选,离子交换树脂的最佳洗脱条件为:以80%乙醇(含1%氯化钠)洗脱剂洗脱时,两种生物碱的洗脱率最高.结论:优选得到的工艺纯化长春花中文多灵和长春质碱效果好,节省溶剂,工艺简单,可用于长春花中两种生物碱的分离纯化.

  6. Strategies for lung regeneration

    Directory of Open Access Journals (Sweden)

    Thomas H. Petersen

    2011-05-01

    Full Text Available Due to the limited ability of the adult lung to regenerate and the frequency of lung disease, the lung is a tissue that can especially benefit from regenerative medicine. Prospects for lung regeneration have made great strides in the past year. In this review, we summarize recent progress and key challenges for approaches in lung regenerative medicine. With a focus on the matrix components critical for the development of regenerative lung tissues, we discuss possible cell sources for lung regeneration, key matrix effects on cell repopulation, and physical stimuli that will aid in the growth of lung tissues in vitro.

  7. Hidrólise parcial da superfície do polyethylene terephthalate (PET: transformando um rejeito em um material de troca catiônica para aplicação ambiental Partial hydrolysis of pet surface: transforming a plastic waste into a material with cationic exchange properties for environmental application

    Directory of Open Access Journals (Sweden)

    Marcelo G. Rosmaninho

    2009-01-01

    Full Text Available In this work it is proposed a simple and versatile undergraduate chemical experiment in polymer and environmental technology based on the process of polyethylene terephthalate (PET hydrolysis. Polyethylene terephthalate from post-consume bottles is submitted to a controlled partial hydrolysis which allows the students to follow the reaction by a simple procedure. The students can explore the reaction kinetics, the effect of catalysts and the exposed polyethylene terephthalate surface area on the hydrolysis reaction. The second and innovative part of this experiment is the technological and environmental application of the hydrolyzed polyethylene terephthalate as a material with cation exchange properties. The surface hydrolyzed polyethylene terephthalate can be used as adsorbent for cationic contaminants.

  8. Radionuclide transport in sandstones with WIPP brine

    International Nuclear Information System (INIS)

    Retardation factors (R) have been measured for the transport of 3H, /sup 95m/Tc, and 85Sr in WIPP brine using St. Peter, Berea, Kayenta, and San Felipe sandstone cores. If tritium is assumed to have R=1, /sup 95m/Tc has R=1.0 to 1.3 and therefore is essentially not retarded. Strontium-85 has R = 1.0 to 1.3 on St. Peter, Berea, and Kayenta, but R=3 on San Felipe. This is attributed to sorption on the matrix material of San Felipe, which has 45 volume % matrix compared with 1 to 10 volume % for the others. Retardation factors (R/sub s/) for 85Sr calculated from static sorption measurements are unity for all the sandstones. Therefore, the static and transport results for 85Sr disagree in the case of San Felipe, but agree for St. Peter, Berea, and Kayenta

  9. Brine migration in hot-pressed polycrystalline sodium chloride

    International Nuclear Information System (INIS)

    This report describes experiments designed to provide data on brine migration in polycrystalline salt. Polycrystalling samples of various grain sizes, density, and purity were prepared from several commercial-grade salts by hot-pressing. Three distinct experimental set-ups were used to place salt billets in an induced thermal gradient in contact with brine source. The test designs varied primarily in the way in which the thermal gradient was applied and monitored and the way in which brine migration was determined. All migration was in enclosed vessels which precluded visual observation of brine movement through the microstructure. Migration velocities were estimated either by the timed appearance of brine at the hot face of the sample, or by determination of the penetration distance of migration artifacts in the microstructure after tests of fixed duration. For various reasons both of these methods were subject to a large degree of error. Our results suggest, however, that the migration velocity in dense polycrystalline salt may be at least an order of magnitude greater than that suggested by single-crystal experiments. Microstructural analysis shows that brine prefers to migrate along paths of high crystalline activity such as grain and subgrain boundaries and is dispersed rather quickly in the microstructure. A series of tests were performed using various types of tracers in brine in order to flag migration paths and locate brine in the microstructure more decisively. These attempts failed and it appears that only the aqueous portion of the brine moves through the microstructure with the dissolved ions being lost and replaced rather quickly. This suggests the use of deuterium as a tracer in future work

  10. Performance and life cycle environmental benefits of recycling spent ion exchange brines by catalytic treatment of nitrate.

    Science.gov (United States)

    Choe, Jong Kwon; Bergquist, Allison M; Jeong, Sangjo; Guest, Jeremy S; Werth, Charles J; Strathmann, Timothy J

    2015-09-01

    Salt used to make brines for regeneration of ion exchange (IX) resins is the dominant economic and environmental liability of IX treatment systems for nitrate-contaminated drinking water sources. To reduce salt usage, the applicability and environmental benefits of using a catalytic reduction technology to treat nitrate in spent IX brines and enable their reuse for IX resin regeneration were evaluated. Hybrid IX/catalyst systems were designed and life cycle assessment of process consumables are used to set performance targets for the catalyst reactor. Nitrate reduction was measured in a typical spent brine (i.e., 5000 mg/L NO3(-) and 70,000 mg/L NaCl) using bimetallic Pd-In hydrogenation catalysts with variable Pd (0.2-2.5 wt%) and In (0.0125-0.25 wt%) loadings on pelletized activated carbon support (Pd-In/C). The highest activity of 50 mgNO3(-)/(min - g(Pd)) was obtained with a 0.5 wt%Pd-0.1 wt%In/C catalyst. Catalyst longevity was demonstrated by observing no decrease in catalyst activity over more than 60 days in a packed-bed reactor. Based on catalyst activity measured in batch and packed-bed reactors, environmental impacts of hybrid IX/catalyst systems were evaluated for both sequencing-batch and continuous-flow packed-bed reactor designs and environmental impacts of the sequencing-batch hybrid system were found to be 38-81% of those of conventional IX. Major environmental impact contributors other than salt consumption include Pd metal, hydrogen (electron donor), and carbon dioxide (pH buffer). Sensitivity of environmental impacts of the sequencing-batch hybrid reactor system to sulfate and bicarbonate anions indicate the hybrid system is more sustainable than conventional IX when influent water contains catalyst reactor systems have potential to reduce resource consumption and improve environmental impacts associated with treating nitrate-contaminated water sources. PMID:26005787

  11. Empirical formula for the refractive index of freezing brine

    DEFF Research Database (Denmark)

    Frisvad, Jeppe Revall

    2009-01-01

    The refractive index of freezing brine is important for example in order to estimate oceanic scattering as sea ice develops. Previously, no simple continuous expression was available for estimating the refractive index of brine at subzero temperatures. I show that extrapolation of the empirical f...... formula for the refractive index of seawater by Quan and Fry [Appl. Opt. 34(18), 3477-3480 (1995)] provides a good fit to the refractive index of freezing brine for temperatures above -24 degrees celsius and salinities below 180 parts per thousand....

  12. Electromagnetic mapping of brine contamination in petroleum producing areas

    International Nuclear Information System (INIS)

    Geophysical electromagnetic devices are well suited to mapping soil and groundwater contamination by oilfield brines. Frequency domain devices such as ground conductivity meters are used for quick assessment of the lateral extent of contamination in the near surface. Time domain devices can accurately define the depth and thickness of the contaminated horizons. Three cases are reviewed which involve the use of geophysical electromagnetic mapping to evaluate brine contamination around a disused drilling pit and an evaporation pond, and to investigate the occurrence of brine relative to local geology in the Michigan Basin. 11 refs., 8 figs

  13. Coastal Plain Soil Fertility Degradation And Natural Forest Ecosystem Regeneration

    Science.gov (United States)

    Casagrande, J. C.; Sato, C. A.; Reis-Duarte, R. M.; Soares, M. R.; Galvão Bueno, M. S.

    2009-04-01

    The sand coastal plain vegetation (Restinga Forest) has been described as an ecosystem associated with the Atlantic Forest, constituted of mosaics, which occur in areas of great ecological diversity, particularly the features of the soil which mostly influence the forest, therefore assigned as edaphic community. The Restinga forest is one of the most fragile, showing low resilience to human damage This work was carried out in several points (14) of Restinga Forest (six low - trees from 3 to 10 m high - and eight high forest - trees from 10 to 15 m high) in the litoral coast of the state of São Paulo. Each sample was made of 15 subsamples of each area collected in each depth (one in 0 - 5, 5 - 10, 10 - 15, 15 - 20, and another in 0 - 20, 20 - 40, 40 and 60 cm). Soil characteristics analyzed were pH, P, Na, K, Ca, Mg, S, H + Al, Al, B, Cu, Fe, Mn, Zn contents and base saturation, cation exchange capacity and aluminum saturation. The vegetation physiognomies of Restinga forest (low and high) were associated with soil results and with the history of human occupation. The soils are sandy (2 to 4% of clay), resulting in a low capacity of nutrient retention. Soil fertility analysis to low and high Restinga forest were similar and showed very low contents of phosphorous, calcium and magnesium in all areas investigated. The base saturation was low due to low amounts of Na, K, Ca and Mg. Base saturation presents low level in all cases, less than 10, indicating low nutritional reserve in the soil. The aluminum saturation values varied from 58 to 69%. The level of calcium and magnesium were low in the subsurface soil layer mainly, associate with high aluminum saturation, representing an limiting factor for the root system development in depth. If soil fertility parameters do not show any significant difference between low and high Restinga physiognomy, what make distinction is the recuperation time. In the areas of high Forest can be note a too long time of recuperation

  14. Occurrence of aspartyl proteases in brine after herring marinating.

    Science.gov (United States)

    Szymczak, Mariusz; Lepczyński, Adam

    2016-03-01

    Herrings are marinated in a brine consisting of salt and acetic acid. During marinating, various nitrogen fractions diffuse from fish flesh to the brine, causing significant nutritional quality losses of the raw material. In this study, it has been demonstrated for the first time that proteases diffuse from the fish to the marinating brine. Using ammonium sulphate precipitation and affinity chromatography on pepstatin-A agarose bed the aspartyl proteases were purified and concentrated over 2600-fold from a marinating brine. Pepstatin-A completely inhibited the activity of the purified preparation. The preparation was active against fluorogenic substrates specific for cathepsin D and E and inactive against substrates specific for cysteine cathepsins. Depending on incubation time, the preparation showed pH-optimum at 2.0 or 4.5. The 2D SDS-PAGE separation demonstrated the presence of a few proteins with molecular weights and pI values typical of cathepsin D, E and pepsin. PMID:26471581

  15. Migration of brine and nitrogen in creeping salt

    International Nuclear Information System (INIS)

    Although the excavations in bedded salt at the Waste Isolation Pilot Plant (WIPP) are, for all practical purposes, dry, small amounts of brine have been observed to weep from exposed surfaces in the repository horizon and seep into drill holes in the underground excavations. As part of the Brine Sampling and Evaluation Program (BSEP) at the WIPP, this study has been made to formulate the complex problem of brine and nitrogen flow through deforming salt as completely as possible. The derived equations are coupled where appropriate in order to closely describe the natural phenomena. The main objective of this paper is to suggest a method by which the formulation might be solved in order to estimate the brine inflow rate into the excavated rooms at the WIPP repository level. The suggested solution method requires the modification and combination of two finite element codes which may necessitate a large amount of computer memory for data storage

  16. Development of the brine shrimp Artemia is accelerated during spaceflight

    Science.gov (United States)

    Spooner, B. S.; Metcalf, J.; DeBell, L.; Paulsen, A.; Noren, W.; Guikema, J. A.

    1994-01-01

    Developmentally arrested brine shrimp cysts have been reactivated during orbital spaceflight on two different Space Shuttle missions (STS-50 and STS-54), and their subsequent development has been compared with that of simultaneously reactivated ground controls. Flight and control brine shrimp do not significantly differ with respect to hatching rates or larval morphology at the scanning and transmission EM levels. A small percentage of the flight larvae had defective nauplier eye development, but the observation was not statistically significant. However, in three different experiments on two different flights, involving a total of 232 larvae that developed in space, a highly significant difference in degree of flight to control development was found. By as early as 2.25 days after reactivation of development, spaceflight brine shrimp were accelerated, by a full instar, over ground control brine shrimp. Although developing more rapidly, flight shrimp grew as long as control shrimp at each developmental instar or stage.

  17. Dense, viscous brine behavior in heterogeneous porous medium systems.

    Science.gov (United States)

    Wright, D Johnson; Pedit, J A; Gasda, S E; Farthing, M W; Murphy, L L; Knight, S R; Brubaker, G R; Miller, C T

    2010-06-25

    The behavior of dense, viscous calcium bromide brine solutions used to remediate systems contaminated with dense nonaqueous phase liquids (DNAPLs) is considered in laboratory and field porous medium systems. The density and viscosity of brine solutions are experimentally investigated and functional forms fit over a wide range of mass fractions. A density of 1.7 times, and a corresponding viscosity of 6.3 times, that of water is obtained at a calcium bromide mass fraction of 0.53. A three-dimensional laboratory cell is used to investigate the establishment, persistence, and rate of removal of a stratified dense brine layer in a controlled system. Results from a field-scale experiment performed at the Dover National Test Site are used to investigate the ability to establish and maintain a dense brine layer as a component of a DNAPL recovery strategy, and to recover the brine at sufficiently high mass fractions to support the economical reuse of the brine. The results of both laboratory and field experiments show that a dense brine layer can be established, maintained, and recovered to a significant extent. Regions of unstable density profiles are shown to develop and persist in the field-scale experiment, which we attribute to regions of low hydraulic conductivity. The saturated-unsaturated, variable-density groundwater flow simulation code SUTRA is modified to describe the system of interest, and used to compare simulations to experimental observations and to investigate certain unobserved aspects of these complex systems. The model results show that the standard model formulation is not appropriate for capturing the behavior of sharp density gradients observed during the dense brine experiments. PMID:20444520

  18. Brine shrimp cytotoxic activities of Hippophae rhamnoides Linn leaves extracts

    OpenAIRE

    Javid Ali; Bashir Ahmad

    2015-01-01

    Objective: To evaluate brine shrimp lethality assay of solvent extracts (aqueous, methanol, ethanol, acetone, ethyl acetate, chloroform and n-hexane) of Hippophae rhamnoides (H. rhamnoides) leaves. Methods: Brine shrimp cytotoxicity assay was used to assess the cytotoxic potential of H. rhamnoides leaves extracts. Three vials for concentration of each extract were made and 10 shrimps per vial (30 shrimps per dilution) were transferred to specific concentration of each extrac...

  19. Brine Shrimp Ecology In The Great Salt Lake, Utah

    OpenAIRE

    Wurtsbaugh, Wayne A.

    1995-01-01

    Hypersaline lakes are noted for their simple communities which facilitate understanding ecological interactions (Williams et al. 1990; Wurtsbaugh 1992; Jellison and Melack 1988). Nevertheless, we still cannot easily predict how environmental changes will effect the population dynamics in these lakes, at least in part because even these simple ecosystems may be more complex than we .realize. Many hypersaline lakes are dominated by the brine shrimp Artemia spp. The production of brine shrimp is...

  20. Characterization of brines and evaporites of Lake Katwe, Uganda

    Science.gov (United States)

    Kasedde, Hillary; Kirabira, John Baptist; Bäbler, Matthäus U.; Tilliander, Anders; Jonsson, Stefan

    2014-03-01

    Lake Katwe brines and evaporites were investigated to determine their chemical, mineralogical and morphological composition. 30 brine samples and 3 solid salt samples (evaporites) were collected from different locations of the lake deposit. Several analytical techniques were used to determine the chemical composition of the samples including Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES), Inductively Coupled Plasma-Sector Field Mass Spectrometry (ICP-SFMS), ion chromatography, and potentiometric titration. The mineralogical composition and morphology of the evaporites was determined using X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. Physical parameters of the lake brines such as density, electrical conductivity, pH, and salinity were also studied. The results show that the lake brines are highly alkaline and rich in Na+, Cl-, CO32-, SO42-, and HCO3- with lesser amounts of K+, Mg2+, Ca2+, Br-, and F- ions. The brines show an intermediate transition between Na-Cl and Na-HCO3 water types. Among the trace metals, the lake brines were found to be enriched in B, I, Sr, Fe, Mo, Ba, and Mn. The solid salts are composed of halite mixed with other salts such as hanksite, burkeite and trona. It was also observed that the composition of the salts varies considerably even within the same grades.

  1. Regeneration under shelterwood

    OpenAIRE

    Erefur, Charlotta

    2007-01-01

    The objectives of this work were to quantify the effects of stand stem density (SSD), orientation and distance with respect to shelter tree, and fertilisation on the establishment of Pinus sylvestris L. and Picea abies (L.) Karst. regenerated by direct seeding and planting at different soil preparations. The field experiments were performed on South (64°14ʼN, 19°46ʼE, 225 m a.s.l.) and North (64°09ʼN, 19°36ʼE, 274 m a.s.l.) slopes in boreal Sweden. Regeneration and early growth in three stand ...

  2. Brine: a computer program to compute brine migration adjacent to a nuclear waste canister in a salt repository

    International Nuclear Information System (INIS)

    This report presents a mathematical model used to predict brine migration toward a nuclear waste canister in a bedded salt repository. The mathematical model is implemented in a computer program called BRINE. The program is written in FORTRAN and executes in the batch mode on a CDC 7600. A description of the program input requirements and output available is included. Samples of input and output are given

  3. An active magnetic regenerator device

    DEFF Research Database (Denmark)

    2015-01-01

    A rotating active magnetic regenerator (AMR) device comprising two or more regenerator beds, a magnet arrangement and a valve arrangement. The valve arrangement comprises a plurality of valve elements arranged substantially immovably with respect to the regenerator beds along a rotational direction...

  4. Infection and Pulp Regeneration

    Directory of Open Access Journals (Sweden)

    Sahng G. Kim

    2016-03-01

    Full Text Available The regeneration of the pulp-dentin complex has been a great challenge to both scientists and clinicians. Previous work has shown that the presence of prior infection may influence the characteristics of tissues formed in the root canal space after regenerative endodontic treatment. The formation of ectopic tissues such as periodontal ligament, bone, and cementum has been observed in the root canal space of immature necrotic teeth with apical periodontitis, while the regeneration of dentin and pulp has been identified in previously non-infected teeth. The current regenerative endodontic therapy utilizes disinfection protocols, which heavily rely on chemical irrigation using conventional disinfectants. From a microbiological point of view, the current protocols may not allow a sufficiently clean root canal microenvironment, which is critical for dentin and pulp regeneration. In this article, the significance of root canal disinfection in regenerating the pulp-dentin complex, the limitations of the current regenerative endodontic disinfection protocols, and advanced disinfection techniques designed to reduce the microorganisms and biofilms in chronic infection are discussed.

  5. Seed recovery and regeneration

    International Nuclear Information System (INIS)

    Magnetohydrodynamic's (MHD) electric power generation capability depends on Faraday's law of induction. An ionized gas, called plasma, passes through a fixed magnetic field. The plasma is produced by seeding flue gases at a temperature of around 2500 deg C with potassium carbonate or formate. In a coal-fired open cycle MHD power plant the potassium seed material is in direct contact with the polluted flue gas from coal combustion. The molten slag droplets will capture a certain amount of potassium. The sulphur dioxide in the flue gases will react with potassium to potassium sulphate. The spent seed material has to be recovered and reprocessed so that the potassium can be reused as seed material. We can distinguish a preprocessing and a regeneration step. Seed preprocessing removes the minerals and volatile coal constituents from the potassium salts. Seed regeneration transforms the purified potassium sulphate into potassium carbonate or formate. Eight regeneration processes have been evaluated. The processes that convert the sulphur of the coal into saleable sulphur or sulphuric acid are still at an early stage of development. Considering all pros and cons, the Formate/Econoseed process appears most suited for seed regeneration purposes in coal-fired MHD systems. For an advanced MHD power plant the mass flow rates of the flue gas and of the potassium containing off-product streams will be calculated. It will be shown that the sulphur content of coal will influence the economical efficiency of the power plant

  6. Regenerated Fe is tasty!

    Science.gov (United States)

    Nuester, J.; Twining, B. S.

    2012-12-01

    Bioavailability of nutrients is an essential factor controlling primary productivity in the ocean. In addition to macronutrients such as nitrogen and phosphorous, availability of the trace element iron unequivocally affects growth rates and community structure of phytoplankton and thereby primary productivity in many ocean regions. External sources of iron such as Aeolian dust, upwelling of Fe-rich waters, and hydrothermal are reduced in high-nutrient low-chlorophyll regions, and most Fe used by phytoplankton has been regenerated by zooplankton. While zooplankton regeneration of Fe was first shown two decades ago, major factors controlling this process such as chemical composition of prey and grazer taxonomy are not well constrained. As pH varies significantly in digestive systems between protozoa and mesozooplankton, we hypothesize that the extent and the bioavailability of regenerated Fe is a function of the digestive physiology. Furthermore, major element components such as silica for diatoms and calcium carbonate for cocolithophores may be able to buffer the pH of digestive systems of different grazer taxa. Such effects may further influence the magnitude and bioavailability of regenerated Fe. In order to constrain the effect of grazer taxonomy and chemical composition of prey on Fe bioavailability, 55Fe-labeled phytoplankton were fed to different grazers and unlabeled phytoplankton were subsequently inoculated to the filtrate of the grazing experiment in the regrowth phase of the experiment, and the uptake of 55Fe into the phytoplankton biomass was monitored over time. A parallel uptake experiment using inorganic 55Fe was used to compare the bioavailability of regenerated and inorganic Fe to the same phytoplankton species. Furthermore, some samples of the inorganic and the regenerated uptake experiments were treated with an oxalate rinse to remove any adsorbed Fe. This allowed us to estimate the adsorption of 55Fe from either source to the cell walls of

  7. Effects of brine migration on waste storage systems. Final report

    International Nuclear Information System (INIS)

    Processes which can lead to mobilization of brine adjacent to spent fuel or nuclear waste canisters and some of the thermomechanical consequences have been investigated. Velocities as high as 4 x 10-7 m s-1 (13 m y-1) are calculated at the salt/canister boundary. As much as 40 liters of pure NaCl brine could accumulate around each canister during a 10-year storage period. Accumulations of bittern brines would probably be less, in the range of 2 to 5 liters. With 0.5% water, NaCl brine accumulation over a 10-year storage cycle around a spent fuel canister producing 0.6 kW of heat is expected to be less than 1 liter for centimeter-size inclusions and less than 0.5 liter for millimeter-size inclusions. For bittern brines, about 25 years would be required to accumulate 0.4 liter. The most serious mechanical consequence of brine migration would be the increased mobility of the waste canister due to pressure solution. In pressure solution enhanced deformation, the existence of a thin film of fluid either between grains or between media (such as between a canister and the salt) provides a pathway by which the salt can be redistributed leading to a marked increase in strain rates in wet rock relative to dry rock. In salt, intergranular water will probably form discontinuous layers rather than films so that they would dominate pressure solution. A mathematical model of pressure solution indicates that pressure solution will not lead to appreciable canister motions except possibly in fine grained rocks (less than 10-4 m). In fine grained salts, details of the contact surface between the canister and the salt bed may lead to large pressure solution motions. A numerical model indicates that heat transfer in the brine layer surrounding a spent fuel canister is not conduction dominated but has a significant convective component

  8. Stimulating endogenous cardiac regeneration

    Directory of Open Access Journals (Sweden)

    Amanda eFinan

    2015-09-01

    Full Text Available The healthy adult heart has a low turnover of cardiac myocytes. The renewal capacity, however, is augmented after cardiac injury. Participants in cardiac regeneration include cardiac myocytes themselves, cardiac progenitor cells, and peripheral stem cells, particularly from the bone marrow compartment. Cardiac progenitor cells and bone marrow stem cells are augmented after cardiac injury, migrate to the myocardium, and support regeneration. Depletion studies of these populations have demonstrated their necessary role in cardiac repair. However, the potential of these cells to completely regenerate the heart is limited. Efforts are now being focused on ways to augment these natural pathways to improve cardiac healing, primarily after ischemic injury but in other cardiac pathologies as well. Cell and gene therapy or pharmacological interventions are proposed mechanisms. Cell therapy has demonstrated modest results and has passed into clinical trials. However, the beneficial effects of cell therapy have primarily been their ability to produce paracrine effects on the cardiac tissue and recruit endogenous stem cell populations as opposed to direct cardiac regeneration. Gene therapy efforts have focused on prolonging or reactivating natural signaling pathways. Positive results have been demonstrated to activate the endogenous stem cell populations and are currently being tested in clinical trials. A potential new avenue may be to refine pharmacological treatments that are currently in place in the clinic. Evidence is mounting that drugs such as statins or beta blockers may alter endogenous stem cell activity. Understanding the effects of these drugs on stem cell repair while keeping in mind their primary function may strike a balance in myocardial healing. To maximize endogenous cardiac regeneration,a combination of these approaches couldameliorate the overall repair process to incorporate the participation ofmultiple cell players.

  9. Effects of a brine discharge over soft bottom Polychaeta assemblage

    Energy Technology Data Exchange (ETDEWEB)

    Pilar-Ruso, Yoana del [Dpto. de Ciencias del Mar y Biologia Aplicada, Universidad de Alicante, Campus de San Vicente del Raspeig, Ap. 99, E-03080, Alicante (Spain)], E-mail: yoana.delpilar@ua.es; Ossa-Carretero, Jose Antonio de la; Gimenez-Casalduero, Francisca; Sanchez-Lizaso, Jose Luis [Dpto. de Ciencias del Mar y Biologia Aplicada, Universidad de Alicante, Campus de San Vicente del Raspeig, Ap. 99, E-03080, Alicante (Spain)

    2008-11-15

    Desalination is a growing activity that has introduced a new impact, brine discharge, which may affect benthic communities. Although the role of polychaetes as indicators to assess organic pollution is well known, their tolerance to salinity changes has not been examined to such a great extent. The aim of this study was to examine the effect of brine discharge over soft bottom polychaete assemblage along the Alicante coast (Southeast Spain) over a two year period. Changes in the polychaete assemblage was analysed using univariate and multivariate techniques. We compared a transect in front of the discharge with two controls. At each transect we sampled at three depths (4, 10 and 15 m) during winter and summer. We have observed different sensitivity of polychaete families to brine discharges, Ampharetidae being the most sensitive, followed by Nephtyidae and Spionidae. Syllidae and Capitellidae showed some resistance initially, while Paraonidae proved to be a tolerant family. - The Polychaete assemblage is affected by the brine discharge of the Alicante desalination plant and we detect different sensitivity levels in polychaete families to brine impact.

  10. Chemistry of glass corrosion in high saline brines

    International Nuclear Information System (INIS)

    Corrosion data obtained in laboratory tests can be used for the performance assessment of nuclear waste glasses in a repository if the data are quantitatively described in the frame of a geochemical model. Experimental data were obtained for conventional pH values corrected for liquid junction, amorphous silica solubility and glass corrosion in concentrated salt brines. The data were interpreted with a geochemical model. The brine chemistry was described with the Pitzer formalism using a data base which allows calculation of brine compositions in equilibrium with salt minerals at temperatures up to 200C. In MgCl2 dominated brines Mg silicates form and due to the consumption of Mg the pH decreases with proceeding reaction. A constant pH (about 4) and composition of alteration products is achieved, when the alkali release from the glass balances the Mg consumption. The low pH results in high release of rare earth elements REE (rare earth elements) and U from the glass. In the NaCl dominated brine MgCl2 becomes exhausted by Mg silicate formation. As long as there is still Mg left in solution the pH decreases. After exhaustion of Mg the pH rises with the alkali release from the glass and analcime is formed

  11. Tissue regeneration with photobiomodulation

    Science.gov (United States)

    Tang, Elieza G.; Arany, Praveen R.

    2013-03-01

    Low level light therapy (LLLT) has been widely reported to reduce pain and inflammation and enhance wound healing and tissue regeneration in various settings. LLLT has been noted to have both stimulatory and inhibitory biological effects and these effects have been termed Photobiomodulation (PBM). Several elegant studies have shown the key role of Cytochrome C oxidase and ROS in initiating this process. The downstream biological responses remain to be clearly elucidated. Our work has demonstrated activation of an endogenous latent growth factor complex, TGF-β1, as one of the major biological events in PBM. TGF-β1 has critical roles in various biological processes especially in inflammation, immune responses, wound healing and stem cell biology. This paper overviews some of the studies demonstrating the efficacy of PBM in promoting tissue regeneration.

  12. Biomaterials for cardiac regeneration

    CERN Document Server

    Ruel, Marc

    2015-01-01

    This book offers readers a comprehensive biomaterials-based approach to achieving clinically successful, functionally integrated vasculogenesis and myogenesis in the heart. Coverage is multidisciplinary, including the role of extracellular matrices in cardiac development, whole-heart tissue engineering, imaging the mechanisms and effects of biomaterial-based cardiac regeneration, and autologous bioengineered heart valves. Bringing current knowledge together into a single volume, this book provides a compendium to students and new researchers in the field and constitutes a platform to allow for future developments and collaborative approaches in biomaterials-based regenerative medicine, even beyond cardiac applications. This book also: Provides a valuable overview of the engineering of biomaterials for cardiac regeneration, including coverage of combined biomaterials and stem cells, as well as extracellular matrices Presents readers with multidisciplinary coverage of biomaterials for cardiac repair, including ...

  13. Bionanomaterials for skin regeneration

    CERN Document Server

    Leonida, Mihaela D

    2016-01-01

    This book gives a concise overview of bionanomaterials with applications for skin regeneration. The advantages and challenges of nanoscale materials are covered in detail, giving a basic view of the skin structure and conditions that require transdermal or topical applications. Medical applications, such as wound healing, care for burns, skin disease, and cosmetic care, such as aging of the skin and photodamage, and how they benefit from bionanomaterials, are described in detail. A final chapter is devoted to the ethical and social issues related to the use of bionanomaterials for skin regeneration. This is an ideal book for researchers in materials science, medical scientists specialized in dermatology, and cosmetic chemists working in formulations. It can also serve as a reference for nanotechnologists, dermatologists, microbiologists, engineers, and polymer chemists, as well as students studying in these fields.

  14. Actinide (III) solubility in WIPP Brine: data summary and recommendations

    Energy Technology Data Exchange (ETDEWEB)

    Borkowski, Marian; Lucchini, Jean-Francois; Richmann, Michael K.; Reed, Donald T.

    2009-09-01

    The solubility of actinides in the +3 oxidation state is an important input into the Waste Isolation Pilot Plant (WIPP) performance assessment (PA) models that calculate potential actinide release from the WIPP repository. In this context, the solubility of neodymium(III) was determined as a function of pH, carbonate concentration, and WIPP brine composition. Additionally, we conducted a literature review on the solubility of +3 actinides under WIPP-related conditions. Neodymium(III) was used as a redox-invariant analog for the +3 oxidation state of americium and plutonium, which is the oxidation state that accounts for over 90% of the potential release from the WIPP through the dissolved brine release (DBR) mechanism, based on current WIPP performance assessment assumptions. These solubility data extend past studies to brine compositions that are more WIPP-relevant and cover a broader range of experimental conditions than past studies.

  15. Prospects of the complex development of highly parameter geothermal brines

    Science.gov (United States)

    Alkhasov, A. B.; Alkhasova, D. A.; Ramazanov, A. Sh.; Kasparova, M. A.

    2015-06-01

    The high efficiency of complex processing of high-temperature hydrothermal brines with utilization of heat energy in a binary geothermal power plant and subsequent extraction of solved chemical compounds is shown. Promising technological schemes are given, where electric power, which is generated in the binary geothermal power plant, is used in a block to recover chemistry components. The technology for integrated processing of geothermal brines of the chloride-sodium-calcium type is developed, which provides the manufacture not only of marketable products but also of practically overall reagents of processed water that are necessary to realize the technology. Priority areas for development are indicated, and the preliminary estimates for a Berikey geothermal deposit are given. It is shown that only established resources of thermal brines of the Berikey deposit make it possible to produce more than 2000 t of lithium carbonate and, thereby, to completely provide Russian industry requirements for it.

  16. Bone regeneration in dentistry

    OpenAIRE

    Tonelli, Paolo; Duvina, Marco; Barbato, Luigi; Biondi, Eleonora; Nuti, Niccolò; Brancato, Leila; Rose, Giovanna Delle

    2011-01-01

    The edentulism of the jaws and the periodontal disease represent conditions that frequently leads to disruption of the alveolar bone. The loss of the tooth and of its bone of support lead to the creation of crestal defects or situation of maxillary atrophy. The restoration of a functional condition involves the use of endosseous implants who require adequate bone volume, to deal with the masticatory load. In such situations the bone need to be regenerated, taking advantage of the biological p...

  17. Determinants of axonal regeneration

    OpenAIRE

    Frisén, J

    1997-01-01

    Axons often regrow to their targets and lost functions may be restored after an injury in the peripheral nervous system. In contrast, axonal regeneration is generally very limited after injuries in the central nervous system, and functional impairment is usually permanent. The regenerative capacity depends on intrinsic neuronal factors as weil as the interaction of neurons with other cells. Glial cells may, in different situations, either support or inhibit axo...

  18. Regeneration of clinoptilolite zeolite used for the ammonium removal; Regeneracion de zeolita clinoptilolita empleada para la remocion de amonio

    Energy Technology Data Exchange (ETDEWEB)

    Garcia G, M.C

    2002-07-01

    The use of zeolites has been increased in the last years with different applications and with a great boom in the environmental area, but a little had been make about the regeneration of such zeolites. The presence of nitrogen-ammonia in water may cause serious pollution problems since it results to be toxic for fishes and other aquatic life forms, also it provokes the algae growing. The natural clinoptilolite contains interchangeable ions such as the sodium (Na{sup +}), potassium (K{sup +}), magnesium (Mg{sup 2+}) and calcium (Ca{sup 2+}) in different proportions depending on the mineral origin When the zeolite is upgraded to its sodium form, the cation exchange capacity and the preference by the nitrogen-ammonia are increased, allowing the reversible process of sorption. In this work it was proposed the regeneration to its sodium form about the ammonia clinoptilolite zeolite. The natural mineral was characterized using the methods such as: X-ray diffraction, Infrared spectroscopy, Thermal gravimetric analysis and surface area. The results show that the ammonium sorption was between 95% and 98.7% such an ambient temperature as a flow back. the zeolite was regenerated approximately from 60% in the first cycle up to 97% in the last cycle at flow back temperature and of 59.2% up to 96.9% at ambient temperature, it was not presented any significant effect which could be attributed to the temperature. During the exchange process, the cations present in the natural zeolite were exchanged with the ammonium ions, this process was not completed due to that retained ammonium quantity was major that of the desorpted ions, what shows that in addition of ion exchange, another type of sorption process exists. (Author)

  19. Heat gradient induced migration of brine inclusions in rock salt

    International Nuclear Information System (INIS)

    A mathematical model for the brine migration in rock salt around an infinite line heat source is set up. The temperature field around the time dependent heat source is calculated by use of Green functions. Numerical solutions are obtained by the computer PSAMA and results are compared with hand calculations for certain simple cases. By general considerations of the migration field approximate values of the brine inflow, which are independent of the source shape, is obtained and these results are used to estimate the agreement with the experimental results from Project Salt Vault. (author)

  20. Assessing Radium Activity in Shale Gas Produced Brine

    Science.gov (United States)

    Fan, W.; Hayes, K. F.; Ellis, B. R.

    2015-12-01

    The high volumes and salinity associated with shale gas produced water can make finding suitable storage or disposal options a challenge, especially when deep well brine disposal or recycling for additional well completions is not an option. In such cases, recovery of commodity salts from the high total dissolved solids (TDS) of the brine wastewater may be desirable, yet the elevated concentrations of the naturally occurring radionuclides such as Ra-226 and Ra-228 in produced waters (sometimes substantially greater than the EPA limit of 5 pCi/L) may concentrate during these steps and limit salt recovery options. Therefore, assessing the potential presence of these Ra radionuclides in produced water from shale gas reservoir properties is desirable. In this study, we seek to link U and Th content within a given shale reservoir to the expected Ra content of produced brine by accounting for secular equilibrium within the rock and subsequent release to Ra to native brines. Produced brine from a series of Antrim shale wells and flowback from a single Utica-Collingwood shale well in Michigan were sampled and analyzed via ICP-MS to measure Ra content. Gamma spectroscopy was used to verify the robustness of this new Ra analytical method. Ra concentrations were observed to be up to an order of magnitude higher in the Antrim flowback water samples compared to those collected from the Utica-Collingwood well. The higher Ra content in Antrim produced brines correlates well with higher U content in the Antrim (19 ppm) relative to the Utica-Collingwood (3.5 ppm). We also observed an increase in Ra activity with increasing TDS in the Antrim samples. This Ra-TDS relationship demonstrates the influence of competing divalent cations in controlling Ra mobility in these clay-rich reservoirs. In addition, we will present a survey of geochemical data from other shale gas plays in the U.S. correlating shale U, Th content with produced brine Ra content. A goal of this study is to develop a

  1. Pressure-induced brine migration into an open borehole in a salt repository

    International Nuclear Information System (INIS)

    This report provides some solutions to models that predict the brine accumulation in an open borehole. In this model, brine flow rates are controlled by pressure differences between the salt and the borehole

  2. Guidelines for using HEC polymers for increasing viscosity of solids-free completion and workover brines

    Energy Technology Data Exchange (ETDEWEB)

    Scheuerman, R.F.

    1983-02-01

    Solids-free brines are used increasingly in well completion and workover operations. One technique to minimize downhole losses of expensive, high-density brine is to spot a pill of thickened brine across the thief zone. Hydroxyethylcellulose (HEC) is the polymer used most frequently for this purpose. This report discusses the properties of HEC-thickened brines and presents guidelines for their use for completion and workover fluid-loss control.

  3. Guidelines for using HEC polymers for viscosifying solids free completion and workover brines

    Energy Technology Data Exchange (ETDEWEB)

    Scheuerman, R.F.

    1982-01-01

    Solids free brines are increasingly used in well completion and workover operations. One technique to minimize downhole losses of expensive, high density brine is to spot a pill of viscosified brine across the thief zone. Hydroxyethylcellulose (HEC) is the polymer most frequently used for this purpose. This report discusses the properties of HEC thickened brines and presents guidelines for their use for completion and workover fluid loss control. 2 refs.

  4. UNDERSTANDING AND MANAGING RISKS POSED BY BRINES CONTAINING DISSOLVED CARBON DIOXIDE

    Science.gov (United States)

    Geologic disposal of supercritical carbon dioxide in saline aquifers and depleted oil and gas fields will cause large volumes of brine to become saturated with dissolved CO2 at concentrations of 50 g/l or more.  As CO2 dissolves in brine, the brine de...

  5. Microbial changes and growth of Listeria monocytogenes during chilled storage of brined shrimp ( Pandalus borealis )

    DEFF Research Database (Denmark)

    Mejlholm, Ole; Kjeldgaard, J.; Modberg, A.;

    2008-01-01

    Thirteen storage trials and ten challenge tests were carried out to examine microbial changes, spoilage and the potential growth of Listeria monocytogenes in brined shrimp (Pandalus borealis). Shrimp in brine as well as brined and drained shrimp in modified atmosphere packaging (MAP) were produce...

  6. Approaches Towards Endogenous Pancreatic Regeneration

    OpenAIRE

    Banerjee, Meenal; Kanitkar, Meghana; Bhonde, Ramesh R.

    2005-01-01

    The phenomenon of pancreatic regeneration in mammals has been well documented. It has been shown that pancreatic tissue is able to regenerate in several species of mammal after surgical insult. This tissue is also known to have the potential to maintain or increase its β-cell mass in response to metabolic demands during pregnancy and obesity. Since deficiency in β-cell mass is the hallmark of most forms of diabetes, it is worthwhile understanding pancreatic regeneration in the context of this...

  7. URBAN REGENERATION PROCESSES IN RIGA

    OpenAIRE

    Guntis Šolks

    2013-01-01

    URBAN REGENERATION PROCESSES IN RIGA ANNOTATION Urban regeneration is characterized by various forms and implications and it is an important research issue for modern urban geography. Riga also has experienced various transformations since the reestablishment of the independence of Latvia. Urban regeneration have an important role in the urban transformation processes, what are providing the revitalization and reuse of urban brownfields, thus contributing to sustainable u...

  8. Understanding Urban Regeneration in Turkey

    Science.gov (United States)

    Candas, E.; Flacke, J.; Yomralioglu, T.

    2016-06-01

    In Turkey, rapid population growth, informal settlements, and buildings and infrastructures vulnerable to natural hazards are seen as the most important problems of cities. Particularly disaster risk cannot be disregarded, as large parts of various cities are facing risks from earthquakes, floods and landslides and have experienced loss of lives in the recent past. Urban regeneration is an important planning tool implemented by local and central governments in order to reduce to disaster risk and to design livable environments for the citizens. The Law on the Regeneration of Areas under Disaster Risk, commonly known as the Urban Regeneration Law, was enacted in 2012 (Law No.6306, May 2012). The regulation on Implementation of Law No. 6306 explains the fundamental steps of the urban regeneration process. The relevant institutions furnished with various authorities such as expropriation, confiscation and changing the type and place of your property which makes urban regeneration projects very important in terms of property rights. Therefore, urban regeneration projects have to be transparent, comprehensible and acceptable for all actors in the projects. In order to understand the urban regeneration process, the legislation and projects of different municipalities in Istanbul have been analyzed. While some steps of it are spatial data demanding, others relate to land values. In this paper an overview of the urban regeneration history and activities in Turkey is given. Fundamental steps of the urban regeneration process are defined, and particularly spatial-data demanding steps are identified.

  9. Selective oxidation of bromide in wastewater brines from hydraulic fracturing.

    Science.gov (United States)

    Sun, Mei; Lowry, Gregory V; Gregory, Kelvin B

    2013-07-01

    Brines generated from oil and natural gas production, including flowback water and produced water from hydraulic fracturing of shale gas, may contain elevated concentrations of bromide (~1 g/L). Bromide is a broad concern due to the potential for forming brominated disinfection byproducts (DBPs) during drinking water treatment. Conventional treatment processes for bromide removal is costly and not specific. Selective bromide removal is technically challenging due to the presence of other ions in the brine, especially chloride as high as 30-200 g/L. This study evaluates the ability of solid graphite electrodes to selectively oxidize bromide to bromine in flowback water and produced water from a shale gas operation in Southwestern PA. The bromine can then be outgassed from the solution and recovered, as a process well understood in the bromine industry. This study revealed that bromide may be selectively and rapidly removed from oil and gas brines (~10 h(-1) m(-2) for produced water and ~60 h(-1) m(-2) for flowback water). The electrolysis occurs with a current efficiency between 60 and 90%, and the estimated energy cost is ~6 kJ/g Br. These data are similar to those for the chlor-alkali process that is commonly used for chlorine gas and sodium hydroxide production. The results demonstrate that bromide may be selectively removed from oil and gas brines to create an opportunity for environmental protection and resource recovery. PMID:23726709

  10. Solar desalination, brine and fine chemicals - a preliminary report

    Digital Repository Service at National Institute of Oceanography (India)

    Shirodkar, P.V.; Nagarajan, R.

    Solar stills put into operation by taking known quantities of sea water of different salinities varying from 27. 75 - 36.27 x 103 during April-May 1990, indicated fresh water yield of 55-68% (av. 64) The volumes of brine as well as those of bitterns...

  11. Solar desalination, brine and fine chemicals - a preliminary report

    Digital Repository Service at National Institute of Oceanography (India)

    Shirodkar, P.V.; Nagarajan, R.

    Solar stills put into operation by taking known quantities of sea water of different salinities varying from 27.75-36.27 x 10 super(3) during April-May 1990, indicated fresh water yield of 55-68% (av. 64). The volumes of brine as well as those...

  12. THE BRINE SHRIMP (ARTMA SALINA) LETHALITY OF SOME FERULAGO SPECIES

    OpenAIRE

    F. HIRLAK, S. DOĞANCA, E. GÜRKAN, O.T. TÜZÜN,

    2015-01-01

    In this work the bio-activities of the extracts obtained from F. asparagifoliaBoiss., F. humilis Boiss., F. aucheri Boiss. (Umbelliferae) are investigatedusing the Brine shrimp method.Key words: Ferulago aucheri, F. humilis, F. asparagifolia, Brineshrimp (Artemia salina).

  13. Treatment of RO brine-towards sustainable water reclamation practice.

    Science.gov (United States)

    Ng, H Y; Lee, L Y; Ong, S L; Tao, G; Viawanath, B; Kekre, K; Lay, W; Seah, H

    2008-01-01

    Treatment and disposal of RO brine is an important part in sustaining the water reclamation practice. RO brine generated from water reclamation contains high concentration of organic and inorganic compounds. Cost-effective technologies for treatment of RO brine are still relatively unexplored. Thus, this study aim to determine a feasible treatment process for removal of both organic and inorganic compounds in RO brine generated from NEWater production. The proposed treatment consists of biological activated carbon (BAC) column followed by capacitive deionization (CDI) process for organic and inorganic removals, respectively. Preliminary bench-scale study demonstrated about 20% TOC removal efficiency was achieved using BAC at 40 mins empty bed contact time (EBCT) while the CDI process was able to remove more than 90% conductivity reducing it from 2.19 mS/cm to only about 164 microS/cm. More than 90% cations and anions in the BAC effluent were removed using CDI process. In addition, TOC and TN removals of 78% and 91%, respectively were also attained through this process. About 90% water recovery was achieved. This process shows the potential of increased water recovery in the reclamation process while volume for disposal can be further minimized. Further studies on the sustainable operation and process optimization are ongoing. PMID:18776632

  14. Durability of concrete materials in high-magnesium brine

    International Nuclear Information System (INIS)

    Cement pastes and mortars representing 11 combinations of candidate concrete materials were cast in the laboratory and monitored for susceptibility to chemical deterioration in high-magnesium brine. Mixtures were selected to include materials included in the current leading candidate concrete for seals at the Waste Isolation Pilot Plant (WIPP). Some materials were included in the experimental matrix to answer questions that had arisen during study of the concrete used for construction of the liner of the WIPP waste-handling shaft. Mixture combinations compared Class C and Class F fly ashes, presence or absence of an expansive component, and presence or absence of salt as a mixture component. Experimental conditions exposed the pastes and mortars to extreme conditions, those being very high levels of Mg ion and an effectively unlimited supply of brine. All pastes and mortars showed deterioration with brine exposure. In general, mortars deteriorated more extensively than the corresponding pastes. Two-inch cube specimens of mortar were not uniformly deteriorated, but showed obvious zoning even after a year in the brine, with a relatively unreacted zone remaining at the center of each cube. Loss of calcium from the calcium hydroxide of paste/aggregate interfaces caused measurable strength loss in the reacted zone comprising the outer portion of every mortar specimen. The current candidate mass concrete for WIPP seals includes salt as an initial component, and has a relatively closed initial microstructure. Both of these features contribute to its suitability for use in large placements within the Salado Formation

  15. Talking about Brine Shrimps: Three Ways of Analysing Pupil Conversations.

    Science.gov (United States)

    Tunnicliffe, Sue Dale; Reiss, Michael J.

    1999-01-01

    Applies three distinct analyses to recorded and transcribed student conversations (n=240) about brine shrimps. The complementary analytic methods provide information on the content of pupils' conversations in terms of the observations made, the ways in which pupils make sense of their observations, and the ways in which students use conversation…

  16. Brine Shrimp and Their Habitat, An Environmental Investigation.

    Science.gov (United States)

    National Wildlife Federation, Washington, DC.

    This environmental unit is one of a series designed for integration within the existing curriculum. The unit is self-contained and students are encouraged to work at their own speed. The philosophy of the unit is based on an experience-oriented process that encourages independent student work. This unit explores the life cycle of brine shrimp and…

  17. Durability of concrete materials in high-magnesium brine

    Energy Technology Data Exchange (ETDEWEB)

    Wakeley, L.D.; Poole, T.S.; Burkes, J.P. [Army Engineer Waterways Experiment Station, Vicksburg, MS (United States). Structures Lab.

    1994-03-01

    Cement pastes and mortars representing 11 combinations of candidate concrete materials were cast in the laboratory and monitored for susceptibility to chemical deterioration in high-magnesium brine. Mixtures were selected to include materials included in the current leading candidate concrete for seals at the Waste Isolation Pilot Plant (WIPP). Some materials were included in the experimental matrix to answer questions that had arisen during study of the concrete used for construction of the liner of the WIPP waste-handling shaft. Mixture combinations compared Class C and Class F fly ashes, presence or absence of an expansive component, and presence or absence of salt as a mixture component. Experimental conditions exposed the pastes and mortars to extreme conditions, those being very high levels of Mg ion and an effectively unlimited supply of brine. All pastes and mortars showed deterioration with brine exposure. In general, mortars deteriorated more extensively than the corresponding pastes. Two-inch cube specimens of mortar were not uniformly deteriorated, but showed obvious zoning even after a year in the brine, with a relatively unreacted zone remaining at the center of each cube. Loss of calcium from the calcium hydroxide of paste/aggregate interfaces caused measurable strength loss in the reacted zone comprising the outer portion of every mortar specimen. The current candidate mass concrete for WIPP seals includes salt as an initial component, and has a relatively closed initial microstructure. Both of these features contribute to its suitability for use in large placements within the Salado Formation.

  18. Progress on radiometric dating of Wolfcamp brines using 4He and 40Ar

    International Nuclear Information System (INIS)

    Ground water samples (brines) from deep wells in the Palo Duro Basin, Texas are being analyzed for noble gases in an attempt to obtain radiometric ages for these brines. The brines contain radiogenic 4He and 40Ar produced from the radioactive decay of U, Th, and K. Consideration of hydrochemical data for the brines, various isotopic, chemical, and mineralogical data for the aquifer rocks and noble gas production rates allow estimating the age of the brines to be about 130 million years at two wells. At a third well interaquifer mixing has occurred and the age is presently indeterminate. 9 references, 3 figures, 1 table

  19. Brine migration in salt and its implications in the geologic disposal of nuclear waste

    International Nuclear Information System (INIS)

    This report respresents a comprehensive review and analysis of available information relating to brine migration in salt surrounding radioactive waste in a salt repository. The topics covered relate to (1) the characteristics of salt formations and waste packages pertinent to considerations of rates, amounts, and effects of brine migration, (2) experimental and theoretical information on brine migration, and (3) means of designing to minimize any adverse effects of brine migration. Flooding, brine pockets, and other topics were not considered, since these features will presumably be eliminated by appropriate site selection and repository design. 115 references

  20. Brine migration in salt and its implications in the geologic disposal of nuclear waste

    Energy Technology Data Exchange (ETDEWEB)

    Jenks, G.H.; Claiborne, H.C.

    1981-12-01

    This report respresents a comprehensive review and analysis of available information relating to brine migration in salt surrounding radioactive waste in a salt repository. The topics covered relate to (1) the characteristics of salt formations and waste packages pertinent to considerations of rates, amounts, and effects of brine migration, (2) experimental and theoretical information on brine migration, and (3) means of designing to minimize any adverse effects of brine migration. Flooding, brine pockets, and other topics were not considered, since these features will presumably be eliminated by appropriate site selection and repository design. 115 references.

  1. Progesterone and peripheral nerve regeneration

    Institute of Scientific and Technical Information of China (English)

    Fei Fan; Haichao Li; Yuwei Wang; Yanglin Zheng; Lianjun Jia; Zhihui Wang

    2006-01-01

    OBJECTIVE: To explore the effect of progesterone on peripheral nerve regeneration.DATA SOURCES: An online search of Medline and OVID databases was under taken to identify articles about progesterone and peripheral nerve regeneration published in English between January 1990 and June 2004 by using the keywords of "peripheral nerve, injury, progesterone, regeneration".STUDY SELECTION: The data were primarily screened, those correlated with progesterone and peripheral nerve regeneration were involved, and their original articles were further searched, the repetitive studies or reviews were excluded.DATA EXTRACTION: Totally 59 articles about progesterone and peripheral nerve regeneration were collected, and 26 of them were involved, the other 33 excluded ones were the repetitive studies or reviews.DATA SYNTHESIS: Recent researches found that certain amount of progesterone could be synthetized in peripheral nervous system, and the expression of progesterone receptor could be found in sensory neurons and Schwann cells. After combined with the receptor, endogenous and exogenous progesterone can accelerate the formation of peripheral nerve myelin sheath, also promote the axonal regeneration.CONCLUSION: Progesterone plays a role in protecting neurons, increasing the sensitivity of nerve tissue to nerve growth factor, and accelerating regeneration of nerve in peripheral nerve regeneration, which provides theoretical references for the treatment of demyelinated disease and nerve injury, as well as the prevention of neuroma, especially that the in vivo level of progesterone should be considered for the elderly people accompanied by neuropathy and patients with congenital luteal phase defect, which is of positive significance in guiding the treatment.

  2. The Basis of Muscle Regeneration

    Directory of Open Access Journals (Sweden)

    Antonio Musarò

    2014-01-01

    Full Text Available Muscle regeneration recapitulates many aspects of embryonic myogenesis and is an important homeostatic process of the adult skeletal muscle, which, after development, retains the capacity to regenerate in response to appropriate stimuli, activating the muscle compartment of stem cells, namely, satellite cells, as well as other precursor cells. Moreover, significant evidence suggests that while stem cells represent an important determinant for tissue regeneration, a “qualified” environment is necessary to guarantee and achieve functional results. It is therefore plausible that the loss of control over these cell fate decisions could lead to a pathological transdifferentiation, leading to pathologic defects in the regenerative process. This review provides an overview about the general aspects of muscle development and discusses the cellular and molecular aspects that characterize the five interrelated and time-dependent phases of muscle regeneration, namely, degeneration, inflammation, regeneration, remodeling, and maturation/functional repair.

  3. Cation exchange and adsorption on clays and clay minerals

    OpenAIRE

    Ammann, Lars

    2003-01-01

    The specific surface area of a clay mineral comprises the external and internal surface area and, finally, the surface area which is exposed to the solution (Chap. 6.1). The aim of this study was to correlate adsorption data of common clays with these specific surface areas.

  4. Sulfonated hydrocarbon graft architectures for cation exchange membranes

    DEFF Research Database (Denmark)

    Nielsen, Mads Møller; Jankova Atanasova, Katja; Hvilsted, Søren

    2013-01-01

    to various degrees. Series of grafting densities and graft lengths are prepared, and membranes are solvent cast from DMSO. The membrane properties in aqueous environments are evaluated from their water swelling behavior, and their thermal properties and stability are investigated by thermogravimetric...

  5. PEMFC contamination model: Foreign cation exchange with ionomer protons

    Science.gov (United States)

    St-Pierre, Jean

    2011-08-01

    A generic, transient fuel cell ohmic loss mathematical model was developed for the case of contaminants that ion exchange with ionomer protons. The model was derived using step changes in contaminant concentration, constant operating conditions and foreign cation transport via liquid water droplets. In addition, the effect of ionomer cations redistribution within the ionomer on thermodynamic, kinetic and mass transport losses and migration were neglected. Thus, a simpler, ideal, ohmic loss case is defined and is applicable to uncharged contaminant species and gas phase contaminants. The closed form solutions were validated using contamination data from a membrane exposed to NH3. The model needs to be validated against contamination and recovery data sets including an NH4+ contaminated membrane exposed to a water stream. A method is proposed to determine model parameters and relies on the prior knowledge of the initial ionomer resistivity. The model expands the number of previously derived cases. Most models in this inventory, derived with the assumption that the reactant is absent, lead to different dimensionless current vs. time behaviors similar to a fingerprint. These model characteristics facilitate contaminant mechanism identification. Separation between membrane and catalyst (electroinactive contaminant) contamination is conceivably possible using additional indicative cell resistance measurements. Contamination is predicted to be significantly more severe under low relative humidity conditions.

  6. Nanocomposites and bone regeneration

    Science.gov (United States)

    James, Roshan; Deng, Meng; Laurencin, Cato T.; Kumbar, Sangamesh G.

    2011-12-01

    This manuscript focuses on bone repair/regeneration using tissue engineering strategies, and highlights nanobiotechnology developments leading to novel nanocomposite systems. About 6.5 million fractures occur annually in USA, and about 550,000 of these individual cases required the application of a bone graft. Autogenous and allogenous bone have been most widely used for bone graft based therapies; however, there are significant problems such as donor shortage and risk of infection. Alternatives using synthetic and natural biomaterials have been developed, and some are commercially available for clinical applications requiring bone grafts. However, it remains a great challenge to design an ideal synthetic graft that very closely mimics the bone tissue structurally, and can modulate the desired function in osteoblast and progenitor cell populations. Nanobiomaterials, specifically nanocomposites composed of hydroxyapatite (HA) and/or collagen are extremely promising graft substitutes. The biocomposites can be fabricated to mimic the material composition of native bone tissue, and additionally, when using nano-HA (reduced grain size), one mimics the structural arrangement of native bone. A good understanding of bone biology and structure is critical to development of bone mimicking graft substitutes. HA and collagen exhibit excellent osteoconductive properties which can further modulate the regenerative/healing process following fracture injury. Combining with other polymeric biomaterials will reinforce the mechanical properties thus making the novel nano-HA based composites comparable to human bone. We report on recent studies using nanocomposites that have been fabricated as particles and nanofibers for regeneration of segmental bone defects. The research in nanocomposites, highlight a pivotal role in the future development of an ideal orthopaedic implant device, however further significant advancements are necessary to achieve clinical use.

  7. Brine crude oil interactions at the oil-water interface

    DEFF Research Database (Denmark)

    Chakravarty, Krishna Hara; Fosbøl, Philip Loldrup; Thomsen, Kaj

    2015-01-01

    mechanisms. The ion specific interaction between fines and polar fractions of crude oil at the oil-water interface has been less explored. In this study the relative affinity between different ions and the oil surface was determined. The experiments prove the importance of Ca2+, SO42-, and HPO42- ions......-, HPO42-, and HCO3- (anions), were studied through gas chromatographic analysis. Crude oil from the North Sea was doped with various fractions of organic acids to mimic different polar behavior. Increased brine concentration showed up to 15% upsurge of polar fractions on the oil-water emulsion formation......The impact of brine salinity and its ionic composition on oil displacement efficiency has been investigated extensively in recent years due to the potential of enhanced oil recovery (EOR). Wettability alterations through relative interactions at the mineral surface have been the basis of proposed...

  8. Stabilization of high mercury contaminated brine purification sludge.

    Science.gov (United States)

    Zhuang, J Ming; Lo, Tony; Walsh, Tony; Lam, Tak

    2004-09-10

    The highly leachable mercury contaminants of brine purification sludge (BPS) generated from the Hg-cell electrolysis process in chlorine production can be stabilized in the treatment procedure employing ferric-lignin derivatives (FLD) (Ligmet binder) and Portland cement (PC). The stabilization effectiveness has been examined by time-based multiple toxicity characteristic leaching procedure (TCLP) tests and sequential TCLP tests. In a period of 50 days, the multiple TCLP tests showed a variation of less than 90 microg l(-1) for the leachable mercury level, and the sequential TCLP tests for the same sample displayed a declining TCLP mercury level. Based on this study, the stabilization of approximately 2000 t of brine purification sludge has been successfully processed with the ferric-lignin derivatives treatment. PMID:15363526

  9. Linear polarization measurements at high temperatures in hypersaline geothermal brines

    Energy Technology Data Exchange (ETDEWEB)

    Cramer, S.D.; Needham, P.B. Jr.

    1978-01-01

    The Bureau of Mines conducted a series of in situ linear polarization measurements in high-temperature, high-pressure hypersaline geothermal brines at the Bureau of Mines Geothermal Test Facility in the Imperial Valley of California. The measurements represented an evaluation of the linear polarization technique for obtaining instantaneous corrosion rates of materials of construction in flowing hypersaline hydrothermal fluids that rapidly form scales on exposed surfaces. A special method was devised for use with the linear polarization technique that resulted in obtaining corrosion rates for 1020 carbon steel, 316 and 430 stainless steel, titanium, various nickel-based alloys, and aluminum 6061 under strong scale-forming conditions. The measurements also provided information on scale-deposition rates in various geothermal environments. Exploratory in situ potentiostatic polarization measurements were made in the flowing brines to qualitatively determine scale-deposition effects on the electrochemical measurements.

  10. Ice Control with Brine Spread with Nozzles on Highways

    DEFF Research Database (Denmark)

    Bolet, Lars; Fonnesbech, Jens Kristian

    2010-01-01

    During the years 1996-2006, the former county of Funen, Denmark, gradually replaced pre-wetted salt with brine spread with nozzles as anti-icing agent in all her ice control activities. The replacement related to 1000 kilometres of highways. Jeopardizing neither road safety nor traffic flow...... the spread rate of pure sodium chloride (and thus the environmental impact) compared to neighbouring counties was less than fifty percent per square meter. Successful pre-salting is, of course, dependent on reliable weather forecasts and on staff well trained in the art of interpreting this information....... The improvements gained by the county of Funen were mainly due to the use of technologies (brine spreading with nozzles) giving a more precise spread pattern than the traditional gritting of pre-wetted salt. The spread pattern for every spreader, tested in The County of Funen, has been meassured 3 hours after...

  11. Amine Solvent Regeneration for CO2 Capture Using Geothermal Energy with Advanced Stripper Configurations

    International Nuclear Information System (INIS)

    Absorption/stripping using alkanol-amine solvents for removing CO2 from the flue gas of coal-fired power plants requires a substantial amount of energy. Typical designs anticipate the use of steam extraction between the Intermediate Pressure (IP) and Low Pressure (LP) turbines to provide heat for the re-boiler. Geothermal energy in the form of hot brine offers an alternative to this large parasitic load on the power generation cycle. We investigate the requirements (number and spacing of extraction/injection well pairs) to provide heat at 150 deg. C for a pilot scale (60 MWe) and a full scale (900 MWe) capture process for thirty years. The calculations are based on properties of a geopressured/geothermal aquifer near the Texas Gulf Coast. In the vicinity of a large coal-fired power plant in South Texas, this aquifer lies between 3 050 and 3 350 m (10 000 and 11 000 ft) below the surface. We present a novel design of the stripper/regenerator process based on heat exchange with the brine, discharging the brine at 100 deg. C. The results indicate that the overall process is feasible and that costs are of similar magnitude to standard designs. (authors)

  12. Amine Solvent Regeneration for CO2 Capture Using Geothermal Energy with Advanced Stripper Configurations

    Directory of Open Access Journals (Sweden)

    Van Wagener D.H.

    2014-11-01

    Full Text Available Absorption/stripping using alkanolamine solvents for removing CO2 from the flue gas of coal-fired power plants requires a substantial amount of energy. Typical designs anticipate the use of steam extraction between the Intermediate Pressure (IP and Low Pressure (LP turbines to provide heat for the reboiler. Geothermal energy in the form of hot brine offers an alternative to this large parasitic load on the power generation cycle. We investigate the requirements (number and spacing of extraction/injection well pairs to provide heat at 150°C for a pilot scale (60 MWe and a full scale (900 MWe capture process for thirty years. The calculations are based on properties of a geopressured/geothermal aquifer near the Texas Gulf Coast. In the vicinity of a large coal-fired power plant in South Texas, this aquifer lies between 3 050 and 3 350 m (10 000 and 11 000 ft below the surface. We present a novel design of the stripper/regenerator process based on heat exchange with the brine, discharging the brine at 100°C. The results indicate that the overall process is feasible and that costs are of similar magnitude to standard designs.

  13. Dispersion of brine discharge from seawater reverse osmosis desalination plants

    OpenAIRE

    Fernández-Torquemada, Yolanda; González-Correa, José Miguel; Loya-Fernández, Angel; Ferrero-Vicente, Luis Miguel; Díaz Valdés, Marta; Sánchez-Lizaso, José Luis

    2008-01-01

    Desalination of seawater has been considered as a potential solution for the water shortage problem in coastal areas and the number of projected and constructed desalination plants has significantly increased in recent years. The challenge of the desalination industry is to produce new water resources without increasing the pressure on the marine environment. Environmental impact of SWRO desalination plants is mainly associated with the discharge into the sea of the brine produced. To estimat...

  14. Modelling of lactic fermentation of carrot slices in salted brines

    OpenAIRE

    Nabais, R.M.; Malcata, F. X.

    1997-01-01

    Increases in suspended biomass and variation in the concentrations of reducing sugars, salt, and lactic acid in brine containing sliced carrots were followed for a period of several days. A tentative unstructured, unsegregated model for the metabolism of suspended Lactobacillus plan tarum coupled with Fick's second law of diffusion for the transport of solutes within the carrot material was postulated. This general model was fitted by non-linear multiresponse regression analysis to an extensi...

  15. Modeling acid-gas generation from boiling chloride brines

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Guoxiang; Spycher, Nicolas; Sonnenthal, Eric; Steefel, Carl

    2009-11-16

    This study investigates the generation of HCl and other acid gases from boiling calcium chloride dominated waters at atmospheric pressure, primarily using numerical modeling. The main focus of this investigation relates to the long-term geologic disposal of nuclear waste at Yucca Mountain, Nevada, where pore waters around waste-emplacement tunnels are expected to undergo boiling and evaporative concentration as a result of the heat released by spent nuclear fuel. Processes that are modeled include boiling of highly concentrated solutions, gas transport, and gas condensation accompanied by the dissociation of acid gases, causing low-pH condensate. Simple calculations are first carried out to evaluate condensate pH as a function of HCl gas fugacity and condensed water fraction for a vapor equilibrated with saturated calcium chloride brine at 50-150 C and 1 bar. The distillation of a calcium-chloride-dominated brine is then simulated with a reactive transport model using a brine composition representative of partially evaporated calcium-rich pore waters at Yucca Mountain. Results show a significant increase in boiling temperature from evaporative concentration, as well as low pH in condensates, particularly for dynamic systems where partial condensation takes place, which result in enrichment of HCl in condensates. These results are in qualitative agreement with experimental data from other studies. The combination of reactive transport with multicomponent brine chemistry to study evaporation, boiling, and the potential for acid gas generation at the proposed Yucca Mountain repository is seen as an improvement relative to previously applied simpler batch evaporation models. This approach allows the evaluation of thermal, hydrological, and chemical (THC) processes in a coupled manner, and modeling of settings much more relevant to actual field conditions than the distillation experiment considered. The actual and modeled distillation experiments do not represent

  16. Modeling acid-gas generation from boiling chloride brines

    International Nuclear Information System (INIS)

    This study investigates the generation of HCl and other acid gases from boiling calcium chloride dominated waters at atmospheric pressure, primarily using numerical modeling. The main focus of this investigation relates to the long-term geologic disposal of nuclear waste at Yucca Mountain, Nevada, where pore waters around waste-emplacement tunnels are expected to undergo boiling and evaporative concentration as a result of the heat released by spent nuclear fuel. Processes that are modeled include boiling of highly concentrated solutions, gas transport, and gas condensation accompanied by the dissociation of acid gases, causing low-pH condensate. Simple calculations are first carried out to evaluate condensate pH as a function of HCl gas fugacity and condensed water fraction for a vapor equilibrated with saturated calcium chloride brine at 50-150 C and 1 bar. The distillation of a calcium-chloride-dominated brine is then simulated with a reactive transport model using a brine composition representative of partially evaporated calcium-rich pore waters at Yucca Mountain. Results show a significant increase in boiling temperature from evaporative concentration, as well as low pH in condensates, particularly for dynamic systems where partial condensation takes place, which result in enrichment of HCl in condensates. These results are in qualitative agreement with experimental data from other studies. The combination of reactive transport with multicomponent brine chemistry to study evaporation, boiling, and the potential for acid gas generation at the proposed Yucca Mountain repository is seen as an improvement relative to previously applied simpler batch evaporation models. This approach allows the evaluation of thermal, hydrological, and chemical (THC) processes in a coupled manner, and modeling of settings much more relevant to actual field conditions than the distillation experiment considered. The actual and modeled distillation experiments do not represent

  17. Brine shrimp lethality bioassay of selected Centaurea L. species (Asteraceae)

    OpenAIRE

    Janaćković P.; Tešević V.; Marin P.D.; Milosavljević S.; Duletić-Laušević Sonja; Janaćković Slavica; Veljić M.

    2008-01-01

    Ether extracts of 15 Centaurea L. species (Asteraceae) methanol extracts of 12species, and cnicin isolated from C. derventana were tested for general bioactivity using the brine shrimp lethality test. Cnicin showed the most potent activity with LC50 0.2. Also, ether extract of C. splendens showed significant activity with LC50 7.3, as did methanol extract of C. arenaria with LC50 12.4.

  18. Cyanobacterial cytotoxicity versus toxicity to brine shrimp Artemia salina

    Czech Academy of Sciences Publication Activity Database

    Hisem, D.; Hrouzek, Pavel; Tomek, P.; Tomšíčková, J.; Zapomělová, Eliška; Skácelová, K.; Lukešová, Alena; Kopecký, Jiří

    2011-01-01

    Roč. 57, č. 1 (2011), s. 76-83. ISSN 0041-0101 R&D Projects: GA ČR GAP504/10/1501 Institutional research plan: CEZ:AV0Z50200510; CEZ:AV0Z60170517; CEZ:AV0Z60660521 Keywords : Secondary metabolites * Brine shrimp bioassay * Health risk assessment Subject RIV: EE - Microbiology, Virology Impact factor: 2.508, year: 2011

  19. Inhibition of Weld Corrosion in Flowing Brines Containing Carbon Dioxide

    OpenAIRE

    Alawadhi, Khaled

    2009-01-01

    The aim of this research was to study the effectiveness of a typical oilfield corrosion inhibitor, which is considered to be a green inhibitor (non toxic to the environment) in controlling internal corrosion of welded X65 pipeline steel in brines saturated with carbon dioxide at one bar pressure, under dynamic flowing conditions, over a range of temperatures. Several experimental configurations were used ranging from a simple flat plate design to a novel rotating cylinder electrode, to all...

  20. Long term corrosion of glasses in salt brines

    OpenAIRE

    Roggendorf, Hans; Schmidt, Helmut K.

    1989-01-01

    Borosilicate glasses are supposed to be a suitable matrix for the fixation of calcined radioactive wastes. For the safety assessment of the disposal of these glasses in geological formations like carnallite or rock salt, their chemical durability in saturated salt brines has been investigated. Temperatures up to 200° C, pressures up to 130 bar, and corrosion times up to 5 years were applied. Special attention was given to the long term corrosion which is mainly characterized by the saturation...

  1. Modeling acid-gas generation from boiling chloride brines

    Directory of Open Access Journals (Sweden)

    Sonnenthal Eric

    2009-11-01

    Full Text Available Abstract Background This study investigates the generation of HCl and other acid gases from boiling calcium chloride dominated waters at atmospheric pressure, primarily using numerical modeling. The main focus of this investigation relates to the long-term geologic disposal of nuclear waste at Yucca Mountain, Nevada, where pore waters around waste-emplacement tunnels are expected to undergo boiling and evaporative concentration as a result of the heat released by spent nuclear fuel. Processes that are modeled include boiling of highly concentrated solutions, gas transport, and gas condensation accompanied by the dissociation of acid gases, causing low-pH condensate. Results Simple calculations are first carried out to evaluate condensate pH as a function of HCl gas fugacity and condensed water fraction for a vapor equilibrated with saturated calcium chloride brine at 50-150°C and 1 bar. The distillation of a calcium-chloride-dominated brine is then simulated with a reactive transport model using a brine composition representative of partially evaporated calcium-rich pore waters at Yucca Mountain. Results show a significant increase in boiling temperature from evaporative concentration, as well as low pH in condensates, particularly for dynamic systems where partial condensation takes place, which result in enrichment of HCl in condensates. These results are in qualitative agreement with experimental data from other studies. Conclusion The combination of reactive transport with multicomponent brine chemistry to study evaporation, boiling, and the potential for acid gas generation at the proposed Yucca Mountain repository is seen as an improvement relative to previously applied simpler batch evaporation models. This approach allows the evaluation of thermal, hydrological, and chemical (THC processes in a coupled manner, and modeling of settings much more relevant to actual field conditions than the distillation experiment considered. The actual

  2. Muscle regeneration in mitochondrial myopathies

    DEFF Research Database (Denmark)

    Krag, T O; Hauerslev, S; Jeppesen, T D;

    2013-01-01

    Mitochondrial myopathies cover a diverse group of disorders in which ragged red and COX-negative fibers are common findings on muscle morphology. In contrast, muscle degeneration and regeneration, typically found in muscular dystrophies, are not considered characteristic features of mitochondrial...... myopathies. We investigated regeneration in muscle biopsies from 61 genetically well-defined patients affected by mitochondrial myopathy. Our results show that the perturbed energy metabolism in mitochondrial myopathies causes ongoing muscle regeneration in a majority of patients, and some were even affected...

  3. Axonal regeneration through arterial grafts.

    OpenAIRE

    Anderson, P. N.; Turmaine, M.

    1986-01-01

    The left common peroneal nerves of adult inbred mice were severed and allowed to regenerate through the lumina of Y-shaped tubes comprising grafts of abdominal aorta and its bifurcation. Very little regeneration took place within the grafts unless the distal nerve stump was inserted into one limb of the Y-tube. Using syngeneic grafts virtually all the axons regenerating through the lumen grew down the limb of the Y-tube containing the distal nerve. Using non-syngeneic grafts, however, a subst...

  4. Survival of foodborne pathogens in natural cracked olive brines.

    Science.gov (United States)

    Medina, Eduardo; Romero-Gil, Verónica; Garrido-Fernández, Antonio; Arroyo-López, Francisco Noé

    2016-10-01

    This work reports the survival (challenge tests) of foodborne pathogen species (Escherichia coli, Staphylococcus aureus, Listeria monocytogenes, and Salmonella enterica) in Aloreña de Málaga table olive brines. The inhibitions were fit using a log-linear model with tail implemented in GInaFIT excel software. The olive brine had a considerable inhibitory effect on the pathogens. The residual (final) populations (Fp) after 24 h was below detection limit (monocytogenes and S. enterica, respectively. Brine dilutions increased Fp and 4Dr, while decreased kmax. A cluster analysis showed that E. coli had an overall quite different behaviour being the most resistant species, but the others bacteria behaved similarly, especially S. aureus and S. enterica. Partial Least Squares regression showed that the most influential phenols on microbial survival were EDA (dialdehydic form of decarboxymethyl elenolic acid), HyEDA (EDA linked to hydroxytyrosol), hydroxytyrosol 4-glucoside, tyrosol, and oleoside 11-methyl ester. Results confirm the adverse habitats of table olives for foodborne pathogenic microorganisms. PMID:27375250

  5. Brine migration test - Asse salt mine, Federal Republic of Germany

    International Nuclear Information System (INIS)

    This document is the final report on the Cooperative German-American 'Brine Migration Tests' that were performed at the Asse Salt Mine in the Federal Republic of Germany (FRG), the Office of Nuclear Waste Isolation (ONWI), Columbus, Ohio, and the Institut fuer Tieflagerung (IfT), Braunschweig, of the Gesellschaft fuer Strahlen- und Umweltforschung mbH Muenchen (GSF). Final test and equipment design as well as manufacturing and installation was carried out by Westinghouse Electric Corporation. The tests were designed to simulate a nuclear waste repository to measure the effects of heat and gamma radiation on brine migration, salt decrepitation, disassociation of brine, and gases collected. The thermal mechanical behavior of salt, such as room closure, stresses and changes of the properties of salt are measured and compared with predicted behavior. The performance of an array of candidate waste package materials, test equipment and procedures under repository conditions will be evaluated with a view towards future in-depth testing of potential repository sites. (orig./RB)

  6. Brine shrimp cytotoxic activities of Hippophae rhamnoides Linn leaves extracts

    Institute of Scientific and Technical Information of China (English)

    JavidAli; BashirAhmad

    2015-01-01

    Objective: To evaluate brine shrimp lethality assay of solvent extracts (aqueous, methanol, ethanol, acetone, ethyl acetate, chloroform and n-hexane) of Hippophae rhamnoides (H. rhamnoides) leaves. Methods: Brine shrimp cytotoxicity assay was used to assess the cytotoxic potential of H. rhamnoides leaves extracts. Three vials for concentration of each extract were made and 10 shrimps per vial (30 shrimps per dilution) were transferred to specific concentration of each extract. Results: The mortality of aqueous extract was 46.7%, methanol extract was 46.7%, ethanolic extract was 50.0%, ethyl acetate was 26.7%, acetone extract was 33.3%, chloroform extract was 40.0% and n-hexane extract was 33.3%. The lowest LD50 was found in methanol extracts (1199.97 µg/mL). Brine shrimp cytotoxicity of tested extracts of H. rhamnoides showed that mortality rate was concentration dependent. Conclusions: It is concluded that bioactive components are present in all leaves extracts of H. rhamnoides, which could be accounted for its pharmacological effects. Thus, the results support the uses of this plant species in traditional medicine.

  7. Ice Control with Brine Spread with Nozzles on Highways:Implementation of Brine Spreading Technologies in Denmark

    OpenAIRE

    Bolet, Lars; Fonnesbech, Jens Kristian

    2010-01-01

    During the years 1996-2006, the former county of Funen, Denmark, gradually replaced pre-wetted salt with brine spread with nozzles as anti-icing agent in all her ice control activities. The replacement related to 1000 kilometres of highways. Jeopardizing neither road safety nor traffic flow the spread rate of pure sodium chloride (and thus the environmental impact) compared to neighbouring counties was less than fifty percent per square meter.Successful pre-salting is, of course, dependent on...

  8. The Effect Of Picking Period And Brining Applications On Fungicide Residue Levels In Brined Vine Leaves Production

    OpenAIRE

    CANGİ, Rüstem; YANAR, Yusuf; YAĞCI, Adem; TOPÇU, Neval; SUCU, Seda; DÜLGEROĞLU, Yağmur

    2014-01-01

    Especially at the time then the leaves are harvested contact and systemic fungicides are applied frequently to protect the grapevine agaist downy mildew and powdery mildew. Intensive pesticide use in vineyard resulted in residue problem on brined vine leaves that are used as food. This study was aimed at development of a proper chemical control program to reduce the pesticide residue problem on vine (Vitis vinifera) leaves in vineyards during the growing period. In this study two fungicides ...

  9. Parameterization of and Brine Storage in MOR Hydrothermal Systems

    Science.gov (United States)

    Hoover, J.; Lowell, R. P.; Cummings, K. B.

    2009-12-01

    Single-pass parameterized models of high-temperature hydrothermal systems at oceanic spreading centers use observational constraints such as vent temperature, heat output, vent field area, and the area of heat extraction from the sub-axial magma chamber to deduce fundamental hydrothermal parameters such as total mass flux Q, bulk permeability k, and the thickness of the conductive boundary layer at the base of the system, δ. Of the more than 300 known systems, constraining data are available for less than 10%. Here we use the single pass model to estimate Q, k, and δ for all the seafloor hydrothermal systems for which the constraining data are available. Mean values of Q, k, and δ are 170 kg/s, 5.0x10-13 m2, and 20 m, respectively; which is similar to results obtained from the generic model. There is no apparent correlation with spreading rate. Using observed vent field lifetimes, the rate of magma replenishment can also be calculated. Essentially all high-temperature hydrothermal systems at oceanic spreading centers undergo phase separation, yielding a low chlorinity vapor and a high salinity brine. Some systems such as the Main Endeavour Field on the Juan de Fuca Ridge and the 9°50’N sites on the East Pacific Rise vent low chlorinity vapor for many years, while the high density brine remains sequestered beneath the seafloor. In an attempt to further understand the brine storage at the EPR, we used the mass flux Q determined above, time series of vent salinity and temperature, and the depth of the magma chamber to determine the rate of brine production at depth. We found thicknesses ranging from 0.32 meters to ~57 meters over a 1 km2 area from 1994-2002. These calculations suggest that brine maybe being stored within the conductive boundary layer without a need for lateral transport or removal by other means. We plan to use the numerical code FISHES to further test this idea.

  10. Regenerable Contaminant Removal System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Regenerable Contaminant Removal System (RCRS) is an innovative method to remove sulfur and halide compounds from contaminated gas streams to part-per-billion...

  11. 阳离子交换树脂催化制备纳米纤维素晶体的谱学性能与流变行为%Spectrum and Rheological Properties of Nanocellulose Crystal Prepared with Cation Exchange Resin

    Institute of Scientific and Technical Information of China (English)

    唐丽荣; 黄彪; 戴达松; 欧文; 李涛; 周东东; 陈学榕

    2011-01-01

    采用强酸型阳离子交换树脂在超声波辅助作用下制备了纳米纤维素晶体(NCC).采用场发射环境扫描电子显微镜(ESEM-FEG)、场发射透射电子显微镜(HR-TEM)、X射线粉末衍射仪(XRD)、傅利叶红外光谱仪(FT-IR)和转子式流变仪对所制备NCC的形貌、谱学和流变学行为进行了研究.结果表明,所制备NCC为近球形,颗粒尺寸约为25nm~50nm,样品属于纤维素Ⅰ型,结晶度为84.26%,晶粒平均由6个晶胞组成.由FT-IR分析可知,NCC仍具有纤维素的基本化学结构.NCC胶体为剪切变稀的假塑性流体,随着温度的升高,其黏度逐渐减小,并最终趋于平缓,结果表明NCC胶体具有较好的稳定性.%Nanocellulose crystal (NCC) was prepared by ultrasonic-assisted hydrolysis with strong acidic cation exchange resin. The size and morphology, crystal structure, spectrum properties and rheological behavior of nanocellulose crystal were investigated by field emission gun environment scanning electron microscopes (ESEM-FEG), field emission transmission electron microscopy (HR-TEM), X-ray diffraction (XRD), Fourier transform infrared spectrometry(FT-IR) and rotor rheometer. The results indicate that the nanocellulose crystal is spherical and the size is about 25 nm~50 nm. The samples have the crystalline cellulose I structure, the crystallinity is 84.26% , and the grain is composed of 6 unit crystal cell. Moreover, the results of FT-IR show that NCC still has the basic chemical structure of cellulose. NCC is the shear thinned pseudoplastic fluid. Futhermore, as the temperature increases, its viscosity decreases, and gradually tends to flat, the results indicate that the samples enjoy nice stability.

  12. 基于阳离子交换-反相混合分离模式的液相色谱-质谱联用检测河豚毒素新方法%Determination of tetrodotoxin using a cation exchange-reverse phase liquid chromatography-mass spectrometric method

    Institute of Scientific and Technical Information of China (English)

    刘希; 陈佳; 刘勤; 郭磊; 毛军文; 谢剑炜

    2012-01-01

    Objective To establish a highly sensitive method suitable for detection of intoxicated biomedical samples with regard to tetrodotoxin ,one of the most toxic non-proteins as well as a hydrophilic small biotoxin . Methods A novel method for detection of tetrodotoxin in human blood plasma by liquid chromatography -time of flight/mass spectrometry ( LC-TOF/MS) technique was established using a cation exchange -reverse phase separation mode. The LC-MS analysis and extraction conditions were systematically optimized. Results For the tetrodotoxin standard sample , the linear calibration curve ranged from 0.1 to 50 mg/L and the limit of detection ( LOD) was 0.01 mg/L. For the tetrodotoxin exposed human plasma sample, the linear calibration curve ranged from 0.5 to 10 mg/L and the LOD was 0.25 mg/L, respectively. Conclusion Such an LC-TOF/MS established for the detection of tetrodotoxin is highly specific and sensitive , and it can be feasible for the detection of tetrodotoxin at mg/L level in puffer fish biosamples.%目的 建立一种可用于检测中毒生物医学样品中小分子生物毒素--河豚毒素的高灵敏度分析方法.方法 选用阳离子交换-反相混合色谱柱,针对河豚毒素亲水性强的特点,建立了一种新型的液相色谱-飞行时间质谱方法对人血浆中河豚毒素进行检测,优化了液相色谱-质谱条件,考察了血浆中河豚毒素的提取方法.结果 对于参考品溶液,河豚毒素的线性范围为0.1~50 mg/L,检测限为0.01 mg/L;对于染毒人血浆样品,河豚毒素的线性范围为0.5~10 mg/L,检测限为0.25 mg/L.结论 所建立的液相色谱-飞行时间质谱方法专属性强、灵敏度高,可适用于实际测定河豚鱼头样品中 mg/L水平的河豚毒素.

  13. Survival of Listeria monocytogenes, Listeria innocua, and Lactic acid bacteria species in chill brine

    OpenAIRE

    Meadows, Bridget Archibald

    2004-01-01

    SURVIVAL OF LISTERIA MONOCYTOGENES, LISTERIA INNOCUA, AND LACTIC ACID BACTERIA SPECIES IN CHILL BRINES Bridget Archibald Meadows (ABSTRACT) Listeria monocytogenes is the major pathogen in ready-to-eat meat products such as deli meats and frankfurters. Contamination can occur via the salt brines that are used to cool thermally processed meats. Both L. monocytogenes and lactic acid bacteria can grow and thrive under these brine conditions, and may become competitive with each ot...

  14. The American brine shrimp as an exotic invasive species in the western Mediterranean

    OpenAIRE

    Amat, Francisco; Hontoria, Francisco; Ruiz, Olga; Green, Andy J.; Sánchez, Marta I.; Figuerola, Jordi; Hortas, F.

    2005-01-01

    The hypersaline environments and salterns present in the western Mediterranean region (including Italy, southern France, the Iberian Peninsula and Morocco) contain autochthonous forms of the brine shrimp Artemia, with parthenogenetic diploid and tetraploid strains coexisting with the bisexual species A. sal- ina. Introduced populations of the American brine shrimp A. franciscana have also been recorded in these Mediterranean environments since the 1980s. Based on brine shrimp cyst samples...

  15. Potentials of converting microalgae into brine shrimp Artemia

    OpenAIRE

    Sorgeloos, P

    1985-01-01

    High densities of brine shrimp Artemia can be cultured in flow-through systems using the effluent of microalgae cultures as a combined source of culture medium and food. It has been proven at the "St. Croix Artificial Upwelling Mariculture Project" that in comparison with the fast growing clam Tapes japonica, brine shrimp assure a much more efficient conversion of plant into animal biomass. It appears from the given examples that microalgae conversion into brine shrimp Artemia offers efficien...

  16. Modeling the interaction of mine brines with chloride minerals of potassium-magnesium deposits

    Science.gov (United States)

    Fetisov, V. V.

    2016-03-01

    The article is devoted to study of dynamics of saturation degree of suprasalt brines with respect to major chloride minerals of salt strata in the initial phase of an accident related to discontinuity of waterproof stratum in the mine of the Verkhnekamskoe salt deposit (Berezniki-3 mine, 1986). Physicochemical modeling has showed that the brines discharged into mine are in equilibrium with halite during all period of observation. At the same time, their degree of saturation with respect to sylvite and carnallite regularly decreases with the increase in inflow of the suprasalt Cl-Na brines. The initial stage of suprasalt brine penetration into mine is characterized by an increase in the saturation degree with respect to the considered chloride minerals, which is showed on the chart presented in the article. However, there are brines oversaturated with respect to halite, which occurs over a brief period. In contrast to the mine brines of different genesis being in equilibrium or close to equilibrium with sylvite, saturation index (SI) for this mineral decreases in the suprasalt brine. This allows one to recommend the use of this parameter in the study of the mine brines to timely detect suprasalt brines entering the mine.

  17. Diverse methane concentrations in anoxic brines and underlying sediments, eastern Mediterranean Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Karisiddaiah, S.M.

    of the brines are extremely high, 2692]103 nM at 3493m, and are 20 times higher than the Bannock Basin values. Thus, based on available physical pro"les (oxygen, temperature and salinity) of water masses in these brines, the approximate boundary of the brine... Atlantis II (mer Rouge). Oceanologica Acta 13, 187}197. Boldrin, A., Rabitti, S., 1990. Hydrography of the brines in the Bannock and Tyro anoxic basins (Eastern Mediterranean). Marine Chemistry 31, 21}33. Camerlenghi, A., Cita, M.B., Hieke, W., Ricchuito, T...

  18. Pressure-induced brine migration in consolidated salt in a repository

    International Nuclear Information System (INIS)

    This report describes a mathematical model for brine migration through intact salt near a radioactive waste package emplaced in salt. Solutions indicate limited movement following ten years emplacement

  19. Strontium isotope evidence on the history of oilfield brines, Mediterranean Coastal Plain, Israel

    Energy Technology Data Exchange (ETDEWEB)

    Starinsky, A.; Bielski, M.; Lazar, B. (Hebrew Univ., Jerusalem (Israel). Dept. of Geology); Steinitz, G.; Raab, M. (Geological Survey of Israel, Jerusalem)

    1983-04-01

    The isotopic composition of Sr in oil field brines from the Mediterranean Coastal Plain was determined in 18 drillholes. The brines are characterized by salinities ranging from 35 to 93 g/l (TDS), Sr from 28 to 350 mg/l, Sr/Ca molar ratios from 0.011 to 0.053 and /sup 87/Sr//sup 86/Sr ratios from 0.7075 to 0.7090. E and A = 0.7081 +- 0.0004 (2sigma). The brines are classified into two groups: (a) Mavqi'im group - brines with relatively high /sup 87/Sr//sup 86/Sr ratios, sampled from clastics, dolomites and anhydrites of Upper Miocene age. (b) Heletz group - brines with relatively low /sup 87/Sr//sup 86/Sr ratios, sampled from sandstones and dolomites of Lower Cretaceous age. Equations were derived to show the relations between /sup 87/Sr//sup 86/Sr ratio of the brines and the processes through which they evolved. It is suggested that both groups of brines originated from Mediterranean evaporated seawater during the Messinian desiccation. The strontium isotope composition of the seawater is reflected in that of both groups of brines, the Mavqi'im group containing the original /sup 87/Sr//sup 86/Sr ratio. The Heletz group evolved later on, through exchange reactions of those primary brines with a carbonate sequence of Cretaceous age and consequently new /sup 87/Sr//sup 86/Sr ratios could have been developed.

  20. Atlantis II Deep geothermal brine system. Hydrographic situation in 1977 and changes since 1965

    Science.gov (United States)

    Hartmann, M.

    1980-02-01

    The geothermal brine system of the Atlantis II Deep in the Red Sea was reinvestigated hydrographically and chemically in November 1977. A comparison with results from earlier investigations confirms an increase of the hot brine volume, as suggested by the 1972 measurements ( SCHOELL, Bundesanstalt für Bodenforschung, Hannover, 1063 pp. 1974). The rate of increase is evidently parallel to the rate of temperature increase. The salinity of the lower brine was nearly constant during this period. The nearby Discovery Deep brine is evidently unaffected by the changes in the Atlantis II Deep as its temperature was constant within ±0.1°C during this time.

  1. Augmenter of liver regeneration

    Directory of Open Access Journals (Sweden)

    Gandhi Chandrashekhar R

    2012-07-01

    Full Text Available Abstract ‘Augmenter of liver regeneration’ (ALR (also known as hepatic stimulatory substance or hepatopoietin was originally found to promote growth of hepatocytes in the regenerating or injured liver. ALR is expressed ubiquitously in all organs, and exclusively in hepatocytes in the liver. ALR, a survival factor for hepatocytes, exhibits significant homology with ERV1 (essential for respiration and viability protein that is essential for the survival of the yeast, Saccharomyces cerevisiae. ALR comprises 198 to 205 amino acids (approximately 22 kDa, but is post-translationally modified to three high molecular weight species (approximately 38 to 42 kDa found in hepatocytes. ALR is present in mitochondria, cytosol, endoplasmic reticulum, and nucleus. Mitochondrial ALR may be involved in oxidative phosphorylation, but also functions as sulfhydryl oxidase and cytochrome c reductase, and causes Fe/S maturation of proteins. ALR, secreted by hepatocytes, stimulates synthesis of TNF-α, IL-6, and nitric oxide in Kupffer cells via a G-protein coupled receptor. While the 22 kDa rat recombinant ALR does not stimulate DNA synthesis in hepatocytes, the short form (15 kDa of human recombinant ALR was reported to be equipotent as or even stronger than TGF-α or HGF as a mitogen for hepatocytes. Altered serum ALR levels in certain pathological conditions suggest that it may be a diagnostic marker for liver injury/disease. Although ALR appears to have multiple functions, the knowledge of its role in various organs, including the liver, is extremely inadequate, and it is not known whether different ALR species have distinct functions. Future research should provide better understanding of the expression and functions of this enigmatic molecule.

  2. Mucosal regeneration during radiotherapy

    International Nuclear Information System (INIS)

    Background and purpose: Regeneration of the aerodigestive mucosa is known to occur during conventionally fractionated radiotherapy. The circumstances surrounding its time of onset and magnitude are not well understood, however. Material and methods: Mucosal reactions were observed in 100 patients undergoing conventionally fractionated treatment at 2 Gy/day over 7 weeks and 88 receiving accelerated treatment at 1.8 Gy twice daily over 3(1(2)) weeks on the Trans Tasman Radiation Oncology Group head and neck cancer trials. Similar observations in 61 patients treated palliatively at dose rates between 0.8 and 240 Gy/h using ten 3.0-4.2 Gy fractions over 2 weeks are compared. Results: Several findings emerged from these studies: 1. Reactions evolved more quickly at oropharyngeal sites than in the hypopharynx. 2. Reactions at both sites evolved more rapidly at greater rates of dose accumulation. 3. The timing of reactions suggested the presence of a strong regenerative mucosal response that started before the manifestation of 'patchy' (grade II) mucosal reactions. 4. The regenerative response was strong enough to 'make good' damage accumulated at a rate of 2 Gy/day in over a third of cases. 5. The linear quadratic model without time correction failed to provide an adequate prediction of the frequency or intensity of mucosal reactions produced by any of the regimes. A simple model of the regenerative response is presented. Conclusions: This study suggests that the timing and magnitude of the regenerative response vary between sites and individuals but are linked to the amount of epithelial cellular depletion occurring during treatment

  3. TOUGHREACT Testing in High Ionic Strength Brine Sandstone Systems

    International Nuclear Information System (INIS)

    Deep saline formations and oil and gas reservoirs often contain concentrated brine solutions of ionic strength greater than 1 (I > 1 M). Geochemical modeling, involving high ionic strength brines, is a challenge. In the original TOUGHREACT code (Xu et al., 2004; Xu et al., 2006), activity coefficients of charged aqueous species are computed using an extended Debye-Huckel (DH) equation and parameters derived by Helgeson et al. (1981). The DH model can deal with ionic strengths from dilute to moderately saline water (up to 6 molal for an NaCl-dominant solution). The equations implemented for the DH model are presented in Appendix A. During the course of the Yucca Mountain project, a Pitzer ion-interaction model was implemented into TOUGHREACT. This allows the application of this simulator to problems involving much more concentrated aqueous solutions, such as those involving geochemical processes in and around high-level nuclear waste repositories where fluid evaporation and/or boiling is expected to occur (Zhang et al., 2007). The Pitzer ion-interaction model, which we refer to as the Pitzer virial approach, and associated ion-interaction parameters have been applied successfully to study non-ideal concentrated aqueous solutions. The formulation of the Pitzer model is presented in Appendix B; detailed information can be founded in Zhang et al. (2007). For CO2 geological sequestration, the Pitzer ion-interaction model for highly concentrated brines was incorporated into TOUGHREACT/ECO2N, then was tested and compared with a previously implemented extended Debye-Hueckel (DH) ion activity model. The comparison was made through a batch geochemical system using a Gulf Coast sandstone saline formation

  4. Transition and separation process in brine channels formation

    Energy Technology Data Exchange (ETDEWEB)

    Berti, Alessia, E-mail: alessia.berti@unibs.it [Facoltà di Ingegneria, Università e-Campus, Via Isimbardi 10, 22060 Novedrate, CO (Italy); Bochicchio, Ivana, E-mail: ibochicchio@unisa.it [Dipartimento di Matematica, Universitá degli Studi di Salerno, Via Giovanni Paolo II, 84084 Fisciano, SA (Italy); Fabrizio, Mauro, E-mail: mauro.fabrizio@unibo.it [Dipartimento di Matematica, Università di Bologna, Piazza di Porta S. Donato, 40126 Bologna (Italy)

    2016-02-15

    In this paper, we discuss the formation of brine channels in sea ice. The model includes a time-dependent Ginzburg-Landau equation for the solid-liquid phase change, a diffusion equation of the Cahn-Hilliard kind for the solute dynamics, and the heat equation for the temperature change. The macroscopic motion of the fluid is also considered, so the resulting differential system couples with the Navier-Stokes equation. The compatibility of this system with the thermodynamic laws and a maximum theorem is proved.

  5. Bone morphogenetic proteins: Periodontal regeneration

    Directory of Open Access Journals (Sweden)

    Subramaniam M Rao

    2013-01-01

    Full Text Available Periodontitis is an infectious inflammatory disease that results in attachment loss and bone loss. Regeneration of the periodontal tissues entails de novo formation of cementum, periodontal ligament, and alveolar bone. Several different approaches are currently being explored to achieve complete, reliable, and reproducible regeneration of periodontal tissues. The therapeutic management of new bone formation is one of the key issues in successful periodontal regeneration. Bone morphogenetic proteins form a unique group of proteins within the transforming growth factor superfamily of genes and have a vital role in the regulation in the bone induction and maintenance. The activity of bone morphogenetic proteins was first identified in the 1960s, but the proteins responsible for bone induction were unknown until the purification and cloning of human bone morphogenetic proteins in the 1980s, because of their osteoinductive potential. Bone morphogenetic proteins have gained a lot of interest as therapeutic agents for treating periodontal defects. A systematic search for data related to the use of bone morphogenetic proteins for the regeneration of periodontal defects was performed to recognize studies on animals and human (PUBMED, MEDLINE, COCHRANE, and Google search. All the studies included showed noticeable regeneration of periodontal tissues with the use of BMP.

  6. Contemporaryperspective on endogenous myocardial regeneration

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Considering the complex nature of the adult heart,it is no wonder that innate regenerative processes,while maintaining adequate cardiac function, fall shortin myocardial jeopardy. In spite of these enchaining limitations, cardiac rejuvenation occurs as well asrestricted regeneration. In this review, the backgroundas well as potential mechanisms of endogenousmyocardial regeneration are summarized. We presentand analyze the available evidence in three subsequentsteps. First, we examine the experimental researchdata that provide insights into the mechanisms andorigins of the replicating cardiac myocytes, includingcell populations referred to as cardiac progenitor cells(i.e. , c-kit+ cells). Second, we describe the role ofclinical settings such as acute or chronic myocardialischemia, as initiators of pathways of endogenousmyocardial regeneration. Third, the hitherto conductedclinical studies that examined different approachesof initiating endogenous myocardial regeneration infailing human hearts are analyzed. In conclusion, wepresent the evidence in support of the notion thatregaining cardiac function beyond cellular replacementof dysfunctional myocardium via initiation of innateregenerative pathways could create a new perspectiveand a paradigm change in heart failure therapeutics.Reinitiating cardiac morphogenesis by reintroducingdevelopmental pathways in the adult failing heart mightprovide a feasible way of tissue regeneration. Basedon our hypothesis "embryonic recall", we present firstsupporting evidence on regenerative impulses in themyocardium, as induced by developmental processes.

  7. Microwave regeneration of molecular sieves

    International Nuclear Information System (INIS)

    Molecular sieve driers have been included in the design of tritium handling systems for fusion reactors. In these systems there is a need to maintain extremely low exit dew points from the driers as well as a capability to rapidly reduce tritium concentrations following an accident. The required capacity of the driers is very high. The conventional method of regenerating these sieves after a water adsorption cycle is with hot air. However, because water is rapidly heated by microwave energy, this technology may be suitable for decreasing the bed regeneration time and hence may allow reduced capital and operating costs associated with a smaller bed. The present study was conducted to obtain preliminary information on the technical feasibility of regenerating molecular sieves with microwave energy. The study concentrated on Type 4A molecular sieve with a few tests on Type 13X sieve and also a silica gel adsorbent

  8. Ice Control with Brine on Highways:Implementation of Brine Spreading Technologies in County of Funen, Denmark

    OpenAIRE

    Bolet, Lars

    2008-01-01

    During the years 1996-2006, the Division of Highways and Transportation in the former county of Funen gradually replaced pre-wetted salt with brine as de-icing agent in all her ice control activities. The replacement related to 1000 kilometres of highways. Jeopardizing neither road safety nor traffic flow the spread rate of pure sodium chloride (and thus the environmental impact) in the pre-salting operations was cut back by more than one third. Compared to neighbouring counties the use of sa...

  9. Analysis of radiolabelled thiocyanate tracer in oil field brines

    International Nuclear Information System (INIS)

    Thiocyanate (SCN-) labelled with 14C or 35S is applicable for the tracing of the water flow in water-driven oil production. This work describes two improved methods for increasing the concentration of S14CN- with sample sizes up to 1000 ml of sampled brine. The radioactivity detection is carried out by low-background liquid scintillation counting using standard-size counting vials of 20 ml. The first method is based on solvent extraction: two extraction/strip steps reduce the volume by the required factor of 100 down to 10 ml. The extraction agent is 0.5M tri-isooctylamine (TiOA) in Solvesso-150 and the stripping agent is 5M NH3. A chemical yield of 70-75%, a somewhat unfavourable quenching factor and a moderate reproducibility lead to a detection limit LD of 0.04 Bq/1. The second method is based on anion exchange. 1000 ml tracer-containing brine may be loaded onto 6.1 ml of the anion-exchange resin AG1-x8 before significant breakthrough of the tracer. More than 98.4% is absorbed. By elution with 2.8M sodiumperchlorate, more than 99.5% of the absorbed tracer is concentrated in a sharp elution peak of 10 ml. With a total chemical yield of 98%, a lower quenching factor and higher reproducibility than for the solvent extraction method, an LD-value of 0.005 Bq/1 is obtained. (orig.)

  10. Selection of a Brine Processor Technology for NASA Manned Missions

    Science.gov (United States)

    Carter, Donald L.; Gleich, Andrew F.

    2016-01-01

    The current ISS Water Recovery System (WRS) reclaims water from crew urine, humidity condensate, and Sabatier product water. Urine is initially processed by the Urine Processor Assembly (UPA) which recovers 75% of the urine as distillate. The remainder of the water is present in the waste brine which is currently disposed of as trash on ISS. For future missions this additional water must be reclaimed due to the significant resupply penalty for missions beyond Low Earth Orbit (LEO). NASA has pursued various technology development programs for a brine processor in the past several years. This effort has culminated in a technology down-select to identify the optimum technology for future manned missions. The technology selection is based on various criteria, including mass, power, reliability, maintainability, and safety. Beginning in 2016 the selected technology will be transitioned to a flight hardware program for demonstration on ISS. This paper summarizes the technology selection process, the competing technologies, and the rationale for the technology selected for future manned missions.

  11. Geochemistry of Salado Formation brines recovered from the Waste Isolation Pilot Plant (WIPP) repository

    International Nuclear Information System (INIS)

    Intergranular brines recovered from the repository horizon of the Waste Isolation Pilot Plant (WIPP) have major- and trace-element compositions that reflect seawater evaporation and diagenetic processes. Brines obtained from repository drill holes are heterogenous with respect to composition, but their compositional fields are distinct from those obtained from fluid inclusions in WIPP halite. The heterogeneity of brine compositions within the drill-hole population indicates a lack of mixing and fluid homogenization within the salt at the repository level. Compositional differences between intergranular (drill hole) and intragranular (fluid inclusions) brines is attributed to isolation of the latter from diagenetic fluids that were produced from dehydration reactions involving gypsum and clay minerals. Modeling of brine-rock equilibria indicates that equilibration with evaporite minerals controls the concentrations of major elements in the brine. Drill-hole brines are in equilibrium with the observed repository minerals halite, anhydrite, magnesite, polyhalite and quartz. The equilibrium model supports the derivation of drill-hole brines from near-field fluid, rather than large-scale vertical migration of fluids from the overlying Rustler or underlying Castile Formations. 13 refs., 6 figs., 6 tabs

  12. Water Recovery from Brine in the Short and Long Term: A KSC Approach

    Science.gov (United States)

    Lunn, Griffin; Melendez, Orlando; Anthony, Steve

    2014-01-01

    KSC has spent many years researching Hollow Fiber Membrane Bioreactors as well as research encompassing: Alternate ammonia removal, Advanced oxidation, Brine purification technologies. KSC-ISRU has built an electrolysis cell for the removal of acids in ISRU mining brines. Our goal is to combine all such technologies.

  13. The isotopic composition of strontium in brines from petroleum fields of southeastern Ohio

    International Nuclear Information System (INIS)

    87Sr/86Sr ratios were determined for one oil and fourteen brines collected from three petroleum reservoirs in southeastern Ohio: the North Logan and Triadelphia fields, both of which are contained within the Clinton sandstone; and the Macksburg field which is contained within the Berea and Macksburg sandstones. Only the Clinton sandstone yields brines that could reasonably be assumed to be uncontaminated with other fluids. The data suggest that in the North Logan field this brine has a characteristic value of 0.7103 +- 0.0005 which persists for distances of at least several kilometers. This persistence, however, does not extend to the Triadelphia field 125 km away where the brine from the Clinton sandstone has a somewhat lower ratio of 0.7092. The 87Sr/86Sr ratio in one sample of oil from the Clinton sandstone in the North Logan field is identical to that in the associated brine. The data from the brines collected from the Macksburg and Berea sandstones in the Macksburg field indicate that these brines are severely contaminated with other fluids. The ratios in all the brines are generally similar to those in the local ground and stream waters, so that the ratios in all the fluids may be governed by the same factors. In southeastern Ohio, the presence of carbonate minerals in the enclosing rocks seems to be the dominant factor in controlling the 87Sr/86Sr ratios of the fluids. (Auth.)

  14. Bag-in-box technology: Membrane filtration of cucumber fermentation brine

    Science.gov (United States)

    A major goal in producing process-ready, brined cucumbers is the reclaiming of the brine obtained from the fermentation for use in other products. This article summarizes research results obtained from the use of membrane filtration technology to remove microbial cells and other sediments from cucu...

  15. Corrosion and hydrogen permeation of A216 Grade WCA steel in hydrothermal magnesium-containing brines

    International Nuclear Information System (INIS)

    Corrosion rates determined at 1 month in 150/degree/C brine increased with magnesium concentration. The structure of the corrosion product, as determined by x-ray diffraction, depended upon the magnesium concentration. In brines with less than 10,000 ppM magnesium, the primary corrosion product had a spinel structure characteristic of magnetite or magnesioferrite. In brines containing magnesium concentrations greater than 20,000 ppM, the primary corrosion product had the amakinite structure characteristic of a complex iron-magnesium hydroxide. The high corrosion rates observed in brines containing high magnesium concentrations suggest that the corrosion products having the amakinite structure is less protective than corrosion products having the spinel structure. Corrosion rates in high-magnesium (inclusion) brine determined over a 6-month test duration were essentially constant. Hydrogen permeation rates observed in exposing mild steel to high-Mg/sup 2/plus// brine at 150/degree/C could be potentially damaging to a mild steel waste package container. The rate of hydrogen permeation was proportional to the brine flow rate in the autoclave. Thiourea additions to the brine increased the hydrogen permeation rate; sulfate and bromide ion additions did not. The maximum gaseous hydrogen pressure attainable is not known (based on 3Fe /plus/ 4H2O /plus/ Fe(sub 3)O /plus/ 4H2, would be /approximately/900 atmospheres), and the dependence of permeation rate on temperature is not known. 8 refs., 13 figs., 3 tabs

  16. Comparison of Phosphoproteomic Separation Strategies Based on Strong Cation Exchange Chromatography-Isoelectric Focusing Techniques%基于强阳离子交换色谱与等电聚焦的磷酸化蛋白质组学分离策略比较

    Institute of Scientific and Technical Information of China (English)

    隋少卉; 董俊军; 王京兰; 蔡耘; 钱小红

    2012-01-01

    Efficient pre-purification steps for the enrichment of phosphorylated proteins or phos-phopeptides are necessary for better detection of phosphorylation sites in phosphoproteomic analysis. Currently, the most common first-dimensional separation technique used is strong cation exchange (SCX). A potential alternative to SCX-based separation is to use isoelectric focusing (IEF) as a first-dimensional separation technique, which has been demonstrated recently. In this study, we present a direct comparison between SCX and IEF based on IPG strips (IPG-IEF) for the phosphoproteomic separation. The comparison experiments discussed in this study utilized standard phosphoproteins and a real sample of HepG2 cell. Then the comparison of 18O labeling phosphopeptides' stability under immobilized pH gradient gel (IPG)-IEF with under SCX was made. Fractions from both technique (SCX and IPG-IEF) were analyzed using the High Mass Accuracy LTQ-FTICR-MS/MS. The results demonstrate that SCX-LTQ-FT and IPG-IEF-LTQ-FT are useful in the phosphopeptides enrichment analysis on a large scale. And SCX-LTQ-FT is relative superior to IPG-IEF-LTQ-FT, whereas the 18 O labeling phosphopeptides'stability under SCX-LTQ-FT is relatively poor with that under IPG-IEF-LTQ-FT.%比较分析了强阳离子交换(SCX)与等电聚焦(IPG-IEF)技术在磷酸化蛋白质组学中的应用.采用3种标准磷酸化蛋白对SCX与IPG-IEF两种技术对磷酸化肽段富集的有效性进行考察.以HepG2细胞为复杂样本,考察SCX与IPG-IEF在实际样本中的应用情况.对SCX与IPG-IEF技术在18O标记的磷酸化蛋白质组定量研究中的应用情况进行考察.蛋白鉴定采用高准确度、高灵敏度、高分辨率的LTQ-FTICR-MS/MS质谱仪.实验表明:SCX和IPG- IEF在大规模磷酸化肽段分离过程中均有效;在复杂样本中,SCX技术的分离效果优于IPG- IEF; IPG- IEF的重复性好于SCX;在磷酸化蛋白质组定量分析结果表明,IPG-IEF技术的稳定性优

  17. 弱酸型聚合物微球固相萃取填料的制备及水中杀虫剂的测定%Preparation of weak acid cation exchange polymer microspheres solid-phase extraction packing and determination of pesticides in river water

    Institute of Scientific and Technical Information of China (English)

    申书昌; 徐雅雯; 马柏凤

    2015-01-01

    The polymer microspheres with lipotropy and weak cation exchange performance were prepared through suspension poly-merization method using styrene and divinyl benzene and methyl acrylate as monomers,PVA as dispersant,benzoyl peroxide as the initiator. The structure and morphology of microspheres were examined by infrared spectrum and scanning electron micro-scope. While observing the structure and morphology of the filler. The composite microspheres were used as solid-phase extraction ( SPE) sorbents for selective extraction nitroclofene,bithionol,praziquantel and albendazole in the river water. Acetonitrile was used as eluent,and the eluate was determined by high performance liquid chromatography. The effects of the sample flow rate and pH, volume and flow rate of eluent on adsorption ratios were investigated,the best solid phase extraction conditions were obtained. The best HPLC condition was chosen. The results show that SiO2/PS composite microspheres have a uniform monodispersity in particle size. The SPE sorbents have good adsorption performance to nitroclofene,bithionol,praziquantel and albendazole in water,and the method of SPE-HPLC for determining the four pesticides has good reproducibility, the detection limits for nitroclofene, bithionol, praziquantel and albendazole were 0. 26μg·L-1 ,0. 31μg·L-1 ,0. 42μg·L-1 and 0. 63μg·L-1 respectively.%本文制备了聚合物基质弱酸型阳离子交换固相萃取填料,以甲基丙烯酸和苯乙烯为原料,二乙烯基苯为交联剂,聚乙烯醇为分散剂,过氧化苯甲酰为引发剂,采用悬浮聚合法制备了具有亲脂和弱阳离子交换性能的球形固相萃取填料,并对其结构和形貌进行了表征。以该聚合物微球作为填料制备固相萃取小柱,萃取水中联硝氯酚、硫双二氯酚、吡喹酮和丙硫苯咪唑4种杀虫剂,乙腈为洗脱剂,洗脱液采用液相色谱分析。分别考察了样品的pH值和流速、洗脱剂的体积和流

  18. Indoor tests to investigate the effect of brine depth on the performance of solar still

    Directory of Open Access Journals (Sweden)

    Marwah AW. Ali, Abdul Jabbar N. Khalifa

    2013-01-01

    Full Text Available Many experimental and numerical studies have been done on different configurations of solar stills to optimize the design by examining the effect of climatic, operational and design parameters on its performance. One of the most important of the operational parameters that has received a considerable attention in the literature is the brine depth. This paper reports indoor experimental investigations on the effect of brine depth on the productivity and efficiency of the solar stills at four different brine depths of 1.5, 2, 4 and 5.5 cm. Indoor tests were used by simulating the solar input by proper electric heaters located at the bottom of the still for heating the water contained in the basin of the still. The present study validated the decreasing trend in productivity with the increase of brine depth and showed that the still productivity could be influenced by the brine depth by up to 24%.

  19. Indoor tests to investigate the effect of brine depth on the performance of solar still

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Marwah A.W.; Jabbar N. Khalifa, Abdul [Nahrain University, College of Engineering, Jadiriya, P.O. Box 64040, Baghdad (Iraq)

    2013-07-01

    Many experimental and numerical studies have been done on different configurations of solar stills to optimize the design by examining the effect of climatic, operational and design parameters on its performance. One of the most important of the operational parameters that has received a considerable attention in the literature is the brine depth. This paper reports indoor experimental investigations on the effect of brine depth on the productivity and efficiency of the solar stills at four different brine depths of 1.5, 2, 4 and 5.5 cm. Indoor tests were used by simulating the solar input by proper electric heaters located at the bottom of the still for heating the water contained in the basin of the still. The present study validated the decreasing trend in productivity with the increase of brine depth and showed that the still productivity could be influenced by the brine depth by up to 24%.

  20. Scanning electron microscope observations of brine shrimp larvae from space shuttle experiments

    Science.gov (United States)

    DeBell, L.; Paulsen, A.; Spooner, B.

    1992-01-01

    Brine shrimp are encysted as gastrula stage embryos, and may remain dehydrated and encysted for years without compromising their viability. This aspect of brine shrimp biology is desirable for studying development of animals during space shuttle flight, as cysts placed aboard a spacecraft may be rehydrated at the convenience of an astronaut, guaranteeing that subsequent brine shrimp development occurs only on orbit and not on the pad during launch delays. Brine shrimp cysts placed in 5 ml syringes were rehydrated with salt water and hatched during a 9 day space shuttle mission. Subsequent larvae developed to the 8th larval stage in the sealed syringes. We studied the morphogenesis of the brine shrimp larvae and found the larvae from the space shuttle experiments similar in rate of growth and extent of development, to larvae grown in sealed syringes on the ground. Extensive differentiation and development of embryos and larvae can occur in a microgravity environment.

  1. Measurement and modeling of CO2 solubility in NaCl brine and CO2–saturated NaCl brine density

    DEFF Research Database (Denmark)

    Yan, Wei; Huang, Shengli; Stenby, Erling Halfdan

    2011-01-01

    over climate change and energy security. This work is an experimental and modeling study of two fundamental properties in high pressure CO2–NaCl brine equilibrium, i.e., CO2 solubility in NaCl brine and CO2–saturated NaCl brine density. A literature review of the available data was presented first to......Phase equilibrium for CO2–NaCl brine is of general interest to many scientific disciplines and technical areas. The system is particularly important to CO2 sequestration in deep saline aquifers and CO2 enhanced oil recovery, two techniques discussed intensively in recent years due to the concerns...... illustrate the necessity of experimental measurements of the two properties at high pressures. An experimental method for measuring high pressure CO2 solubility in NaCl brine was then developed. With the method, CO2 solubilities in 0, 1, and 5m NaCl brines were measured at 323, 373, and 413K from 5 to 40MPa...

  2. Investigations of inorganic and organic fouling behaviors, antifouling and cleaning strategies for pressure retarded osmosis (PRO) membrane using seawater desalination brine and wastewater.

    Science.gov (United States)

    Han, Gang; Zhou, Jieliang; Wan, Chunfeng; Yang, Tianshi; Chung, Tai-Shung

    2016-10-15

    By employing seawater desalination brine (SWBr) and wastewater brine (WWBr) as the feed pair, membrane fouling behaviors as well as antifouling and cleaning strategies for the state-of-the-art thin-film composite polyethersulfone (TFC-PES) hollow fiber membrane have been systematically investigated under pressure retarded osmosis (PRO) operations. Fouling on the polyamide selective layer induced by the SWBr draw solution is relatively mild because of the outstanding membrane rejection and the hydration antifouling layer formed by the permeating water. However, using WWBr as the feed causes fast and severe internal concentration polarization (ICP) and fouling within the porous PES substrate, which result in dramatic flux and power density declines. In addition, the PRO fouling upon and within the porous substrate is highly irreversible. Experimental data show that both anti-scalant pretreatment and pH adjustment of WWBr could effectively mitigate inorganic fouling, while increasing feed flow velocity along the substrate surface is ineffective for fouling control. To clean the fouled membranes, hydraulic-pressure induced backwash and flushing with alkaline and NaOCl solutions on the fouled surface are effective strategies to remove foulants and regenerate membranes with a flux recovery of 83-90%. However, osmotic backwash shows low cleaning efficiency in PRO. In summary, a proper combination of feed pretreatment and membrane cleaning strategies has been demonstrated in this study to sustain PRO operations with a high water flux and power density. PMID:27470469

  3. Clinical implications of advances in liver regeneration

    OpenAIRE

    Kwon, Yong Jin; Lee, Kyeong Geun; Choi, Dongho

    2015-01-01

    Remarkable advances have been made recently in the area of liver regeneration. Even though liver regeneration after liver resection has been widely researched, new clinical applications have provided a better understanding of the process. Hepatic damage induces a process of regeneration that rarely occurs in normal undamaged liver. Many studies have concentrated on the mechanism of hepatocyte regeneration following liver damage. High mortality is usual in patients with terminal liver failure....

  4. Survival of Escherichia coli O157:H7 during manufacture and storage of white brined cheese.

    Science.gov (United States)

    Osaili, Tareq M; Al-Nabulsi, Anas A; Olaimat, Amin N; Shaker, Reyad R; Taha, Mohammad; Holley, Richard A

    2014-09-01

    Escherichia coli O157:H7 is a major foodborne pathogen that causes severe disease in humans. Survival of E. coli O157:H7 during processing and storage of white brined cheese was investigated. Cheeses were prepared using pasteurized milk inoculated with a 4 strain E. coli O157:H7 cocktail (7 log(10) CFU/g) with or without yogurt starter culture (Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus salivarius ssp. thermophilus) and stored in 10% or 15% NaCl brine at 10 and 21 ºC for 28 d. NaCl concentration, water activity (a(w)), pH, and numbers of E. coli O157:H7 and lactic acid bacteria (LAB) were determined in cheese and brine. E. coli O157:H7 was able to survive in cheese stored in both brines at 10 and 21 ºC regardless of the presence of starter LAB, although the latter significantly enhanced E. coli O157:H7 reduction in cheese or its brine at 10 ºC. E. coli O157:H7 numbers were reduced by 2.6 and 3.4 log(10) CFU/g in cheese stored in 10% and 15% NaCl brine, respectively, in the presence of starter LAB and by 1.4 and 2.3 log(10) CFU/g, respectively, in the absence of starter LAB at 10 ºC. The pathogen survived, but at lower numbers in the brines. The salt concentration of cheese stored in 10% brine remained about 5% during ripening, but in 15% brine, the NaCl level increased 1.6% to 8.1% (w/w) by 28 d. Values of pH and a(w) slightly decreased 1 d after exposure to brine and reached 5.5 to 6.6 and 0.88 to 0.94, respectively, in all treatments. PMID:25134419

  5. All optical regeneration using semiconductor devices

    DEFF Research Database (Denmark)

    Mørk, Jesper; Öhman, Filip; Tromborg, Bjarne

    All-optical regeneration is a key functionality for implementing all-optical networks. We present a simple theory for the bit-error-rate in links employing all-optical regenerators, which elucidates the interplay between the noise and and nonlinearity of the regenerator. A novel device structure ...... analyzed, emphasizing general aspects of active semiconductor waveguides....

  6. Semiconductor devices for all-optical regeneration

    DEFF Research Database (Denmark)

    Öhman, Filip; Bischoff, Svend; Tromborg, Bjarne;

    2003-01-01

    We review different implementations of semiconductor devices for all-optical regeneration. A general model will be presented for all-optical regeneration in fiber links, taking into consideration the trade-off between non-linearity and noise. Furthermore we discuss a novel regenerator type, based...

  7. An experimental study of passive regenerator geometries

    DEFF Research Database (Denmark)

    Engelbrecht, Kurt; Nielsen, Kaspar Kirstein; Pryds, Nini

    2011-01-01

    experimental uncertainty associated with magnetocaloric material properties, all regenerators are made of aluminum. The performance of corrugated plates and dimpled plates are compared to traditional flat plate regenerators for a range of cycle times and utilizations. Each regenerator is built using 18...

  8. Cytoskeletal regulation of dermal regeneration.

    Science.gov (United States)

    Strudwick, Xanthe L; Cowin, Allison J

    2012-01-01

    Wound healing results in the repair of injured tissues however fibrosis and scar formation are, more often than not the unfortunate consequence of this process. The ability of lower order vertebrates and invertebrates to regenerate limbs and tissues has been all but lost in mammals; however, there are some instances where glimpses of mammalian regenerative capacity do exist. Here we describe the unlocked potential that exists in mammals that may help us understand the process of regeneration post-injury and highlight the potential role of the actin cytoskeleton in this process. The precise function and regulation of the cytoskeleton is critical to the success of the healing process and its manipulation may therefore facilitate regenerative healing. The gelsolin family of actin remodelling proteins in particular has been shown to have important functions in wound healing and family member Flightless I (Flii) is involved in both regeneration and repair. Understanding the interactions between different cytoskeletal proteins and their dynamic control of processes including cellular adhesion, contraction and motility may assist the development of therapeutics that will stimulate regeneration rather than repair. PMID:24710556

  9. Mechanical device for tissue regeneration

    NARCIS (Netherlands)

    Herder, J.L.; Maij, E.

    2010-01-01

    The invention relates to a mechanical device for tissue- regeneration inside a patient, comprising means (2, 3) to place a scaffold for the tissue under mechanical stress. Said means comprise a first device-part (2) and a second device-part (3) which parts are arranged to be movable with respect to

  10. Electrochemical Ion-Exchange Regeneration and Fluidized Bed Crystallization for Zero-Liquid-Discharge Water Softening.

    Science.gov (United States)

    Chen, Yingying; Davis, Jake R; Nguyen, Chi H; Baygents, James C; Farrell, James

    2016-06-01

    This research investigated the use of an electrochemical system for regenerating ion-exchange media and for promoting the crystallization of hardness minerals in a fluidized bed crystallization reactor (FBCR). The closed-loop process eliminates the creation of waste brine solutions that are normally produced when regenerating ion-exchange media. A bipolar membrane electrodialysis stack was used to generate acids and bases from 100 mM salt solutions. The acid was used to regenerate weak acid cation (WAC) ion-exchange media used for water softening. The base solutions were used to absorb CO2 gas and to provide a source of alkalinity for removing noncarbonate hardness by WAC media operated in H(+) form. The base solutions were also used to promote the crystallization of CaCO3 and Mg(OH)2 in a FBCR. The overall process removes hardness ions from the water being softened and replaces them with H(+) ions, slightly decreasing the pH value of the softened water. The current utilization efficiency for acid and base production was ∼75% over the operational range of interest, and the energy costs for producing acids and bases were an order of magnitude lower than the costs for purchasing acid and base in bulk quantities. Ion balances indicate that the closed-loop system will accumulate SO4(2-), Cl(-), and alkali metal ions. Acid and base balances indicate that for a typical water, small amounts of base will be accumulated. PMID:27161852

  11. Optical Regeneration and Noise in Semiconductor Devices

    DEFF Research Database (Denmark)

    Öhman, Filip

    2005-01-01

    In this report all-optical 2R-regeneration in optical communication systems is investigated. A simple regenerator device based on concatenated semiconductor optical amplifiers (SOAs) and electro absorbers (EAs) is introduced and examined. Experiments show that the monolithic SOA-EA 2R-regenerator......In this report all-optical 2R-regeneration in optical communication systems is investigated. A simple regenerator device based on concatenated semiconductor optical amplifiers (SOAs) and electro absorbers (EAs) is introduced and examined. Experiments show that the monolithic SOA-EA 2R...

  12. Microprobe analysis of brine shrimp grown on meteorite extracts

    International Nuclear Information System (INIS)

    Nuclear microprobe methods have been used to investigate the uptake and distribution of various elements by brine shrimps and their unhatched eggs when grown in extracts of the Murchison and Allende carbonaceous meteorites, which were selected as model space resources. Measurements were carried out using a focussed 2 MeV proton beam raster scanned over the samples in order to obtain the average elemental concentrations. Line scans across the egg and shrimp samples show uptake of elements such as Mg, Ni, S and P which are present in the meteorites. The results confirmed that carbonaceous chondrite materials can provide nutrients, including high levels of the essential nutrient phosphate. The concentrations of these elements varied significantly between shrimp and eggs grown in extracts of the two meteorite types, which can help in identifying optimal growth media. Our results illustrate that nuclear microprobe techniques can determine elemental concentrations in organisms exposed to meteorite derived media and thus help in identifying useful future resources

  13. Effect of electroosmotic flow on brine imbibition in porous media

    Institute of Scientific and Technical Information of China (English)

    Rui WANG; Xiang-an YUE; Xu WEI; Wei ZHANG

    2009-01-01

    Based on Darcy's Law and the Helmholta-Smoluchowski equation, an imbibition velocity formula for the water phase with an electric field was deduced, showing that the imbibition velocity with an electric field is to various extents not only-related to the rock permeability and characteristic length, the fluid viscosity, the oil-water interface tension and the gravity of the imbibing brine, but also to the fluid dielectric permittivity, zeta potential, applied electric field direction, and strength. Imbibition experiments with electric fields that are different in direction and strength were conducted, showing that application of a positive electric field enhances the imbibition velocity and increases the imbibition recovery ratio, while application of a negative electric field reduces the imbibition velocity and decreases the imbibition recovery ratio. The imbibition recovery ratio with a positive electric field increases with the strength of the electric field, and the imbibition recovery ratio with a negative electric field is lower than that without an electric field.

  14. Study of photon attenuation coefficient in brine using MCNP code

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, Caroline M.; Salgado, Cesar M.; Brandao, Luis E.B., E-mail: carolmattosb@yahoo.com.br, E-mail: otero@ien.gov.br, E-mail: brandao@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    In petroleum industry, multiphase flows are common and the relative salt content of the water component depends on the location of oil extraction. The salt present in the water component causes incrustations in the pipeline and may interfere in the flow measurement. This paper presents an elaborate model using MCNP code to simulate a narrow beam gamma ray source, a brine sample and a NaI(Tl) detector, with beam energies ranging from 59,54 keV to 662 keV. Through this model, we can relate the photon attenuation coefficient to the salinity of water. This model can be experimentally reproduced, and used to measure the salinity in situ without affecting the medium. (author)

  15. Microprobe analysis of brine shrimp grown on meteorite extracts

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, J. [National Isotope Centre, GNS Science, 30 Gracefield Road, Lower Hutt (New Zealand)]. E-mail: j.kennedy@gns.cri.nz; Mautner, M.N. [Soil, Plant and Ecological Sciences Division, Lincoln University (New Zealand) and Department of Chemistry, University of Canterbury, Christchurch 8001 (New Zealand)]. E-mail: m.mautner@solis1.com; Barry, B. [National Isotope Centre, GNS Science, 30 Gracefield Road, Lower Hutt (New Zealand); Markwitz, A. [National Isotope Centre, GNS Science, 30 Gracefield Road, Lower Hutt (New Zealand)

    2007-07-15

    Nuclear microprobe methods have been used to investigate the uptake and distribution of various elements by brine shrimps and their unhatched eggs when grown in extracts of the Murchison and Allende carbonaceous meteorites, which were selected as model space resources. Measurements were carried out using a focussed 2 MeV proton beam raster scanned over the samples in order to obtain the average elemental concentrations. Line scans across the egg and shrimp samples show uptake of elements such as Mg, Ni, S and P which are present in the meteorites. The results confirmed that carbonaceous chondrite materials can provide nutrients, including high levels of the essential nutrient phosphate. The concentrations of these elements varied significantly between shrimp and eggs grown in extracts of the two meteorite types, which can help in identifying optimal growth media. Our results illustrate that nuclear microprobe techniques can determine elemental concentrations in organisms exposed to meteorite derived media and thus help in identifying useful future resources.

  16. Microprobe analysis of brine shrimp grown on meteorite extracts

    Science.gov (United States)

    Kennedy, J.; Mautner, M. N.; Barry, B.; Markwitz, A.

    2007-07-01

    Nuclear microprobe methods have been used to investigate the uptake and distribution of various elements by brine shrimps and their unhatched eggs when grown in extracts of the Murchison and Allende carbonaceous meteorites, which were selected as model space resources. Measurements were carried out using a focussed 2 MeV proton beam raster scanned over the samples in order to obtain the average elemental concentrations. Line scans across the egg and shrimp samples show uptake of elements such as Mg, Ni, S and P which are present in the meteorites. The results confirmed that carbonaceous chondrite materials can provide nutrients, including high levels of the essential nutrient phosphate. The concentrations of these elements varied significantly between shrimp and eggs grown in extracts of the two meteorite types, which can help in identifying optimal growth media. Our results illustrate that nuclear microprobe techniques can determine elemental concentrations in organisms exposed to meteorite derived media and thus help in identifying useful future resources.

  17. Guiding brine shrimp through mazes by solving reaction diffusion equations

    Science.gov (United States)

    Singal, Krishma; Fenton, Flavio

    Excitable systems driven by reaction diffusion equations have been shown to not only find solutions to mazes but to also to find the shortest path between the beginning and the end of the maze. In this talk we describe how we can use the Fitzhugh-Nagumo model, a generic model for excitable media, to solve a maze by varying the basin of attraction of its two fixed points. We demonstrate how two dimensional mazes are solved numerically using a Java Applet and then accelerated to run in real time by using graphic processors (GPUs). An application of this work is shown by guiding phototactic brine shrimp through a maze solved by the algorithm. Once the path is obtained, an Arduino directs the shrimp through the maze using lights from LEDs placed at the floor of the Maze. This method running in real time could be eventually used for guiding robots and cars through traffic.

  18. CO2/ brine substitution experiments at simulated reservoir conditions

    Science.gov (United States)

    Kummerow, Juliane; Spangenberg, Erik

    2015-04-01

    Capillary properties of rocks affect the mobility of fluids in a reservoir. Therefore, the understanding of the capillary pressure behaviour is essential to assess the long-term behaviour of CO2 reservoirs. Beyond this, a calibration of the petrophysical properties on water saturation of reservoir rocks at simulated in situ conditions is crucial for a proper interpretation of field monitoring data. We present a set-up, which allows for the combined measurements of capillary pressure, electric resistivity, and elastic wave velocities under controlled reservoir conditions (pconf = 400 bar, ppore = 180 bar, T = 65 ° C) at different brine-CO2 saturations. The capillary properties of the samples are measured using the micropore membrane technique. The sample is jacketed with a Viton tube (thickness = 4 mm) and placed between two current electrode endcaps, which as well contain pore fluid ports and ultrasonic P and S wave transducers. Between the sample and the lower endcap the hydrophilic semi-permeable micro-pore membrane (pore size = 100 nm) is integrated. It is embedded into filter papers to establish a good capillary contact and to protect the highly sensitive membrane against mechanical damage under load. Two high-precision syringe pumps are used to displace a quantified volume of brine by CO2 and determine the corresponding sample saturation. The fluid displacement induces a pressure gradient along the sample, which corresponds to the capillary pressure at a particular sample saturation. It is measured with a differential pressure sensor in the range between 0 - 0.2 MPa. Drainage and imbibition cycles are performed to provide information on the efficiency of capillary trapping and to get a calibration of the petrophysical parameters of the sample.

  19. Brine Organisms and the Question of Habitat Specific Adaptation

    Science.gov (United States)

    Siegel, B. Z.; Siegel, S. M.; Speitel, Thomas; Waber, Jack; Stoecker, Roy

    1984-12-01

    Among the well-known ultrasaline terrestrial habitats, the Dead Sea in the Jordan Rift Valley and Don Juan Pond in the Upper Wright Valley represent two of the most extreme. The former is a saturated sodium chloride-magnesium sulfate brine in a hot desert, the latter a saturated calcium chloride brine in an Antarctic desert. Both Dead Sea and Don Juan water bodies themselves are limited in microflora, but the saline Don Juan algal mat and muds contain abundant nutrients and a rich and varied microbiota, including Oscillatoria, Gleocapsa, Chlorella, diatoms, Penicillium and bacteria. In such environments, the existence of an array of specific adaptations is a common, and highly reasonable, presumption, at least with respect to habitat-obligate forms. Nevertheless, many years of ongoing study in our laboratory have demonstrated that lichens (e.g. Cladonia), algae (e.g. Nostoc) and fungi (e.g. Penicillium, Aspergillus) from the humid tropics can sustain metabolism down to -40°C and growth down to -10°C in simulated Dead Sea or Don Juan (or similar) media without benefit of selection or gradual acclimation. Non-selection is suggested in fungi by higher growth rates from vegetative inocula than spores. The importance of nutrient parameters was also evident in responses to potassium and reduced nitrogen compounds. In view of the saline performance of tropical Nostoc, and its presence in the Antarctic dry valley soils, its complete absence in our Don Juan mat samples was and remains a puzzle. We suggest that adaptive capability is already resident in many terrestrial life forms not currently in extreme habitats, a possible reflection of evolutionary selection for wide spectrum environmental adaptability.

  20. Composition of brine discharge from tunisian desalination plants

    International Nuclear Information System (INIS)

    Use of unconventional water resources such as desalination is becoming inevitable sources to alleviate water scarcity in the world. Desalination of brackish water is one of the non conventional water resources that the Tunisian government developed in order to enhance the quality of water distributed in the south. Despite the many benefits desalination technology has to offer a list of potential environmental like the emissions of air pollutant, the energy demand, land use but the main impact of desalination plant is caused by the discharge of an effluent of very high salinity. The constant discharge of reject streams with high salinity and temperature can be fatal for marine life. The purpose of this study is to evaluate the chemical composition of reject brine from Gabes desalination plant and Jerba desalination plant. Both desalination plants are planted to securing the fresh water supply for consumer consumption to the respectively government Gabes and Jerba when the level of salinity is exceeded 3g /l. The average capacity of these plants varied between 25000m3/d and 30 000m3/d. Water samples were collected from several locations at reject site of both desalination plant Jerba and Gabes. All samples have been analysed for major, nutritive and minor constituents The analyses reveal a difference between the compositions of brine of the both stations, The comparison between quality of the effluent discharged and Tunisian norms of reject in hydraulic areas (NT 106 002) showed that the concentration of calcium, chlorides sodium sulphates are higher than the allowable limits the norms.

  1. Buoyancy-driven CO2/brine flow at reservoir conditions

    Science.gov (United States)

    Oh, J.; Kim, K.; Han, W.; Kim, T.; Kim, J.; Park, E.

    2013-12-01

    Suitable geological formations should guarantee a long-term safe and reliable storage of the injected supercritical CO2. In this study we targeted the cases of gravity-driven CO2 plume migration in a storage formation and the resulting CO2 leakage to overlying formation through a possible fractures or abandoned wells. A laboratory experiment and numerical model for two-phase core-flooding tests were designed to understand the buoyancy effect on supercritical CO2 migration under reservoir conditions. A series of core flooding tests were performed with Berea sandstone cores which have 20 % porosity and 1.7×10-13 m2 permeability. Unlike the normal core-flooding tests, the core was set up in a vertical direction and the CO2 was released at the bottom of the core to investigate the gravity effect on CO2 migration. During the test, the downstream pressure was maintained at 10 MPa, and the confining pressure was kept at 20 MPa. The temperature was set to be 40 °C to reflect the 1 km subsurface environment. The CO2-flooding (drainage) tests with brine-saturated core were performed with various CO2-release periods. The CO2 saturation was measured with a linear X-ray scanner. In addition to laboratory experiments, numerical simulations were performed to provide further insight into the CO2 migration behavior. TOUGH2 with ECO2N module was used to simulate CO2/brine core-flooding tests. Dimensionless numbers (Capillary number and Bond number) were calculated with the simulation results at various time points covering both the release and monitoring period.

  2. Multimeric hemoglobin of the Australian brine shrimp Parartemia.

    Science.gov (United States)

    Coleman, M; Matthews, C M; Trotman, C N

    2001-04-01

    The hemoglobin molecule of the commercially important brine shrimp Artemia sp. has been used extensively as a model for the study of molecular evolution. It consists of nine globin domains joined by short linker sequences, and these domains are believed to have originated through a series of duplications from an original globin gene. In addition, in Artemia, two different polymers of hemoglobin, called C and T, are found which differ by 11.7% at the amino acid level and are believed to have diverged about 60 MYA. This provides a set of data of 18 globin domain sequences that have evolved in the same organism. The pattern of amino acid substitution between these two polymers is unusual, with pairs of equivalent domains displaying differences of up to 2.7-fold in total amino acid substitution. Such differences would reflect a similar range of molecular-clock rates in what appear to be duplicate, structurally equivalent domains. In order to provide a reference outgroup, we sequenced the cDNA for a nine-domain hemoglobin (P) from another genus of brine shrimp, Parartemia zietziana, which differs morphologically and ecologically from Artemia and is endemic to Australia. Parartemia produces only one hundredth the amount of hemoglobin that Artemia produces and does not upregulate production in response to low oxygen partial pressure. Comparison of the globin domains at the amino acid and DNA levels suggests that the Artemia globin T gene has accumulated substitutions differently from the Parartemia P and Artemia C globin genes. We discuss the questions of accelerated evolution after duplication and possible functions for the Parartemia globin. PMID:11264409

  3. On the viscosity of natural hyper-saline solutions and its importance: The Dead Sea brines

    Science.gov (United States)

    Weisbrod, Noam; Yechieli, Yoseph; Shandalov, Semion; Lensky, Nadav

    2016-01-01

    The relationship between the density, temperature and viscosity of hypersaline solutions, both natural and synthetic, is explored. An empirical equation of the density-viscosity relationship as a function of temperature was developed for the Dead Sea brine and its dilutions. The viscosity levels of the Dead Sea brine (density of 1.24 ṡ 103 kg/m3; viscosity of 3.6 mPa s at 20 °C) and of the more extremely saline natural brine (density of 1.37 ṡ 103 kg/m3) were found to be ∼3 and ∼10 times greater than that of fresh water, respectively. The combined effect of the above changes in viscosity and density on the hydraulic conductivity is reduction by a factor of 3-7. The chemical composition significantly affects the viscosity of brines with similar densities, whereby solutions with a higher Mg/Na ratio have higher viscosity. This explains the extremely high viscosity of the Dead Sea and related Mg-rich brines in comparison with the much lower values of NaCl and KCl brines with similar density. Possible impacts of the results include reduced settling velocity of grains in hypersaline viscous brines and changing hydraulic dynamics at the freshwater-saltwater and the vicinity of sinkholes.

  4. Capillarity and wetting of carbon dioxide and brine during drainage in Berea sandstone at reservoir conditions

    Science.gov (United States)

    Al-Menhali, Ali; Niu, Ben; Krevor, Samuel

    2015-10-01

    The wettability of CO2-brine-rock systems will have a major impact on the management of carbon sequestration in subsurface geological formations. Recent contact angle measurement studies have reported sensitivity in wetting behavior of this system to pressure, temperature, and brine salinity. We report observations of the impact of reservoir conditions on the capillary pressure characteristic curve and relative permeability of a single Berea sandstone during drainage—CO2 displacing brine—through effects on the wetting state. Eight reservoir condition drainage capillary pressure characteristic curves were measured using CO2 and brine in a single fired Berea sandstone at pressures (5-20 MPa), temperatures (25-50°C), and ionic strengths (0-5 mol kg-1 NaCl). A ninth measurement using a N2-water system provided a benchmark for capillarity with a strongly water wet system. The capillary pressure curves from each of the tests were found to be similar to the N2-water curve when scaled by the interfacial tension. Reservoir conditions were not found to have a significant impact on the capillary strength of the CO2-brine system during drainage through a variation in the wetting state. Two steady-state relative permeability measurements with CO2 and brine and one with N2 and brine similarly show little variation between conditions, consistent with the observation that the CO2-brine-sandstone system is water wetting and multiphase flow properties invariant across a wide range of reservoir conditions.

  5. Purification of High Salinity Brine by Multi-Stage Ion Concentration Polarization Desalination.

    Science.gov (United States)

    Kim, Bumjoo; Kwak, Rhokyun; Kwon, Hyukjin J; Pham, Van Sang; Kim, Minseok; Al-Anzi, Bader; Lim, Geunbae; Han, Jongyoon

    2016-01-01

    There is an increasing need for the desalination of high concentration brine (>TDS 35,000 ppm) efficiently and economically, either for the treatment of produced water from shale gas/oil development, or minimizing the environmental impact of brine from existing desalination plants. Yet, reverse osmosis (RO), which is the most widely used for desalination currently, is not practical for brine desalination. This paper demonstrates technical and economic feasibility of ICP (Ion Concentration Polarization) electrical desalination for the high saline water treatment, by adopting multi-stage operation with better energy efficiency. Optimized multi-staging configurations, dependent on the brine salinity values, can be designed based on experimental and numerical analysis. Such an optimization aims at achieving not just the energy efficiency but also (membrane) area efficiency, lowering the true cost of brine treatment. ICP electrical desalination is shown here to treat brine salinity up to 100,000 ppm of Total Dissolved Solids (TDS) with flexible salt rejection rate up to 70% which is promising in a various application treating brine waste. We also demonstrate that ICP desalination has advantage of removing both salts and diverse suspended solids simultaneously, and less susceptibility to membrane fouling/scaling, which is a significant challenge in the membrane processes. PMID:27545955

  6. Wettability from Capillarity of CO2-Brine-Rock Systems at Reservoir Conditions

    Science.gov (United States)

    Al-Menhali, Ali; Niu, Ben; Krevor, Samuel

    2015-04-01

    The wettability of CO2-brine-rock systems will have a major impact on the management of carbon sequestration in subsurface geological formations. Recent contact angle measurement studies have reported sensitivity in wetting behaviour of this system to pressure, temperature and brine salinity. We report results of an investigation into the impact of reservoir conditions on wetting through direct observations of their impact on the capillary strength of the system. Eight capillary pressure characteristic curves were measured using CO2 and brine in a single fired Berea sandstone at pressures (5 to 20 MPa), temperatures (25 to 50 °C) and ionic strengths (0 to 5 M kg-1 NaCl) representative of subsurface reservoirs. A ninth measurement using an N2-water system provided a benchmark for capillarity with a strongly water wet system. The semi-dynamic capillary pressure core flooding technique was used with in situ saturation monitoring. In all cases, the capillarity of the system, scaled by the interfacial tension, were equivalent to the N2-water system within measurement uncertainty. Thus reservoir conditions did not have a significant impact on the capillary strength of the CO2-brine system through a variation in wetting. Two steady-state relative permeability measurements with CO2 and brine and one with N2 and brine similarly show little variation between conditions, consistent with the observation that the CO2-brine-sandstone system is strongly water wetting and invariant across a wide range of reservoir conditions.

  7. Deep well injection of brine from Paradox Valley, Colorado: Potential major precipitation problems remediated by nanofiltration

    Science.gov (United States)

    Kharaka, Y.K.; Ambats, G.; Thordsen, J.J.; Davis, R.A.

    1997-01-01

    Groundwater brine seepage into the Dolores River in Paradox Valley, Colorado, increases the dissolved solids load of the Colorado River annually by ~2.0 x 108 kg. To abate this natural contamination, the Bureau of Reclamation plans to pump ~3540 m3/d of brine from 12 shallow wells located along the Dolores River. The brine, with a salinity of 250,000 mg/L, will be piped to the deepest (4.9 km) disposal well in the world and injected mainly into the Mississippian Leadville Limestone. Geochemical modeling indicates, and water-rock experiments confirm, that a huge mass of anhydrite (~1.0 x 104 kg/d) likely will precipitate from the injected brine at downhole conditions of 120??C and 500 bars. Anhydrite precipitation could increase by up to 3 times if the injected brine is allowed to mix with the highly incompatible formation water of the Leadville Limestone and if the Mg in this brine dolomitizes the calcite of the aquifer. Laboratory experiments demonstrate that nanofiltration membranes, which are selective to divalent anions, provide a new technology that remediates the precipitation problem by removing ~98% of dissolved SO4 from the hypersaline brine. The fluid pressure used (50 bars) is much lower than would be required for traditional reverse osmosis membranes because nanofiltration membranes have a low rejection efficiency (5-10%) for monovalent anions. Our results indicate that the proportion of treatable brine increases from ~60% to >85% with the addition of trace concentrations of a precipitation inhibitor and by blending the raw brine with the effluent stream.

  8. Weeks Island brine diffuser site study: baseline conditions and environmental assessment technical report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-12-12

    This technical report presents the results of a study conducted at two alternative brine diffuser sites (A and B) proposed for the Weeks Island salt dome, together with an analysis of the potential physical, chemical, and biological effects of brine disposal for this area of the Gulf of Mexico. Brine would result from either the leaching of salt domes to form or enlarge oil storage caverns, or the subsequent use of these caverns for crude oil storage in the Strategic Petroleum Reserve (SPR) program. Brine leached from the Weeks Island salt dome would be transported through a pipeline which would extend from the salt dome either 27 nautical miles (32 statute miles) for Site A, or 41 nautical miles (47 statute miles) for Site B, into Gulf waters. The brine would be discharged at these sites through an offshore diffuser at a sustained peak rate of 39 ft/sup 3//sec. The disposal of large quantities of brine in the Gulf could have a significant impact on the biology and water quality of the area. Physical and chemical measurements of the marine environment at Sites A and B were taken between September 1977 and July 1978 to correlate the existing environmental conditions with the estimated physical extent of tthe brine discharge as predicted by the MIT model (US Dept. of Commerce, 1977a). Measurements of wind, tide, waves, currents, and stratification (water column structure) were also obtained since the diffusion and dispersion of the brine plume are a function of the local circulation regime. These data were used to calculate both near- and far-field concentrations of brine, and may also be used in the design criteria for diffuser port configuration and verification of the plume model. Biological samples were taken to characterize the sites and to predict potential areas of impact with regard to the discharge. This sampling focused on benthic organisms and demersal fish. (DMC)

  9. Hydrological and geochemical monitoring for a CO2 sequestration pilot in a brine formation

    OpenAIRE

    Doughty, Christine; Pruess, Karsten; Benson, Sally M.; Freifeld, Barry M.; Gunter, William D.

    2004-01-01

    Hydrological and geochemical monitoring are key components of site characterization and CO2 plume monitoring for a pilot test to inject CO2 into a brine-bearing sand of the fluvial-deltaic Frio formation in the upper Texas Gulf Coast. In situ, injected CO2 forms a supercritical phase that has gas-like properties (low density and viscosity) compared to the surrounding brine, while some CO2 dissolves in the brine. The pilot test employs one injection well and one monitor well, with contin...

  10. Examination of brine contamination risk to aquatic resources from petroleum development in the Williston Basin

    Science.gov (United States)

    Gleason, Robert A.; Thamke, Joanna N.; Smith, Bruce D.; Tangen, Brian A.; Chesley-Preston, Tara; Preston, Todd M.

    2011-01-01

    U.S. Geological Survey scientists and cooperating partners are examining the potential risk to aquatic resources (for example, wetlands, streams) by contamination from saline waters (brine) produced by petroleum development in the Williston Basin of Montana, North Dakota, and South Dakota. The primary goals of this study are to provide a science-based approach to assess potential risk of brine contamination to aquatic systems and to help focus limited monitoring and mitigation resources on the areas of greatest need. These goals will be accomplished through field investigations that quantify brine movement and risk assessments using remotely-sensed and other spatial datasets.

  11. Synthesis of hydroxy sodalite from coal fly ash using waste industrial brine solution.

    Science.gov (United States)

    Musyoka, Nicholas M; Petrik, Leslie F; Balfour, Gillian; Gitari, Wilson M; Hums, Eric

    2011-01-01

    The effect of using industrial waste brine solution instead of ultra pure water was investigated during the synthesis of zeolites using three South African coal fly ashes as Si feedstock. The high halide brine was obtained from the retentate effluent of a reverse osmosis mine water treatment plant. Synthesis conditions applied were; ageing of fly ash was at 47 ° C for 48 hours, and while the hydrothermal treatment temperature was set at 140 ° C for 48 hours. The use of brine as a solvent resulted in the formation of hydroxy sodalite zeolite although unconverted mullite and hematite from the fly ash feedstock was also found in the synthesis product. PMID:22175873

  12. Buoyancy effects on upward brine displacement caused by CO2 injection

    Energy Technology Data Exchange (ETDEWEB)

    Oldenburg, C.M.; Rinaldi, A.

    2010-01-15

    Upward displacement of brine from deep reservoirs driven by pressure increases resulting from CO{sub 2} injection for geologic carbon sequestration may occur through improperly sealed abandoned wells, through permeable faults, or through permeable channels between pinch-outs of shale formations. The concern about upward brine flow is that, upon intrusion into aquifers containing groundwater resources, the brine may degrade groundwater. Because both salinity and temperature increase with depth in sedimentary basins, upward displacement of brine involves lifting fluid that is saline but also warm into shallower regions that contain fresher, cooler water. We have carried out dynamic simulations using TOUGH2/EOS7 of upward displacement of warm, salty water into cooler, fresher aquifers in a highly idealized two-dimensional model consisting of a vertical conduit (representing a well or permeable fault) connecting a deep and a shallow reservoir. Our simulations show that for small pressure increases and/or high-salinity-gradient cases, brine is pushed up the conduit to a new static steady-state equilibrium. On the other hand, if the pressure rise is large enough that brine is pushed up the conduit and into the overlying upper aquifer, flow may be sustained if the dense brine is allowed to spread laterally. In this scenario, dense brine only contacts the lower-most region of the upper aquifer. In a hypothetical case in which strong cooling of the dense brine occurs in the upper reservoir, the brine becomes sufficiently dense that it flows back down into the deeper reservoir from where it came. The brine then heats again in the lower aquifer and moves back up the conduit to repeat the cycle. Parameter studies delineate steady-state (static) and oscillatory solutions and reveal the character and period of oscillatory solutions. Such oscillatory solutions are mostly a curiosity rather than an expected natural phenomenon because in nature the geothermal gradient prevents the

  13. Deep brine recognition upstream the EBE syndicate. Geochemical and isotopic investigations. Final report

    International Nuclear Information System (INIS)

    The authors report and discuss the results obtained after performing a drilling upstream the drinkable water harnessing field of a water supply syndicate in Alsace (Ensisheim, Bollwiller and surroundings), in order to confirm the existence of a deep brine source. This brine is diluted by recent waters. The first isotopic investigations do not allow the origin of this brine to be identified, but fractures due to some seismic events are suspected. The report presents the drilling and the various aspects of the chemical and isotopic studies (sampling, physico-chemical analysis, dating, identification of various isotopes)

  14. Evaluation of the bioactivities of some Myanmar medicinal plants using brine shrimp (Artemia salina) toxicity test

    International Nuclear Information System (INIS)

    For a variety of toxic substances, brine shrimp larvae (Artemia salina) are usually used as a simple bioassay method and it is also applied for natural product research. The brine shrimp larvae (nauplii) are obtained by natural hatching method from Artemia cysts. By using the larvae, the results from these experiments lead to the lethal dose, LD50 values of extracts of selected medicinal plants. Activities of a broad range of plant extracts are manifested as toxicity to the brine shrimp. Screening results with six plant extracts are compared with pure caffeine. This method is rapid, reliable, inexpensive and convenient. (author)

  15. A Brine Shrimp Bioassay for Measuring Toxicity and Remediation of Chemicals

    Science.gov (United States)

    Lieberman, Marya

    1999-12-01

    A bioassay using Artemia franciscana (brine shrimp) was adapted to measure the toxicity of household chemicals. One project is described in which students collect dose-response curves for seven commercial flea-killing products. Next, groups of students researched the insecticidal ingredients of the flea products. On the basis of the structures of the active ingredients, they chose remediation methods to make the flea product less toxic to brine shrimp; procedures included copper-catalyzed hydrolysis, adsorption onto activated charcoal, bleach treatment, and photodegradation. No special equipment or supplies are necessary for the bioassay other than the brine shrimp eggs, which can be obtained at any aquarium store.

  16. Financing Property's Contribution to Regeneration

    OpenAIRE

    Alastair Adair; Jim Berry; Stanley McGreal

    2003-01-01

    Attracting investment and finance into inner-city and other renewal areas poses particular difficulties and is frequently reliant on strong public-sector commitment through special incentives or other mechanisms to provide the conditions to lever private-sector activity. This paper initially links the concept of market failure and the rationale for regeneration and examines policy responses from UK, European and US perspectives, followed by a consideration of public- and private-sector financ...

  17. Progenitor Cells and Podocyte Regeneration

    OpenAIRE

    Shankland, Stuart J.; Pippin, Jeffrey W.; Duffield, Jeremy S.

    2014-01-01

    The very limited ability of adult podocytes to proliferate in vivo is clinically significant because: podocytes form a vascular barrier which is functionally critical to the nephron; podocyte hypoplasia is a characteristic of disease; and inadequate regeneration of podocytes is a major cause of persistent podocyte hypoplasia. Excessive podocyte loss or inadequate replacement leads to glomerulosclerosis in many progressive kidney diseases. Thus, restoration of podocyte cell density is almost c...

  18. Cell Therapy for Cardiovascular Regeneration

    OpenAIRE

    Takehara, Naofumi

    2013-01-01

    A great numbers of cardiovascular disease patients all over the world are suffering in the poor outcomes. Under this situation, cardiac regeneration therapy to reorganize the postnatal heart that is defined as a terminal differentiated-organ is a very important theme and mission for human beings. However, the temporary success of several clinical trials using usual cell types with uncertain cell numbers has provided the transient effect of cell therapy to these patients. We therefore should r...

  19. Regeneration of Pelargonium in vitro

    OpenAIRE

    Agnieszka Wojtania; Wiesław Szafrański

    2013-01-01

    Pelargonium sp. has been a subject of numerous studies to deterimine the effec tiveness of in vitro techniques to produce a large number of pathogen-free plants. Regeneration of pelargonium plants from the different initial explants as well via organogenesis as via somatic embryogenesis has been obtained. The most effective adventitious shoot formation has been achieved from shoot tips and axillary buds using cytokinin or cytokinin/auxin combinations. Leaf explants, whose general have lower o...

  20. Quo vadis, hair cell regeneration?

    OpenAIRE

    Brigande, John V; Heller, Stefan

    2009-01-01

    Hearing loss is a global health problem with profound socioeconomic impact. We contend that acquired hearing loss is mainly a modern disorder caused by man-made noise and modern drugs, among other causes. These factors, combined with increasing lifespan, have exposed a deficit in cochlear self-regeneration that was irrelevant for most of mammalian evolution. Nevertheless, the mammalian cochlea has evolved from phylogenetically older structures, which do have the capacity for self-repair. More...

  1. Contribuição de constituintes de solo à capacidade de troca de cátions obtida por diferentes métodos de extração Contribution of soil constituents to the cation exchange capacity as determined by different extraction methods

    Directory of Open Access Journals (Sweden)

    Edson Campanhola Bortoluzzi

    2009-06-01

    Full Text Available A capacidade de troca de cátions (CTC é uma propriedade físico-química intrínseca aos constituintes minerais e orgânicos do solo. Apesar do uso de diferentes extratores e procedimentos, a CTC é normalmente expressa considerando apenas o controle ou não do pH na solução extratora. O objetivo deste trabalho foi discutir o significado da contribuição da matéria orgânica do solo prepresentada pelo carbono orgânico total (COT e da argila à capacidade de troca de cátions de um Argissolo quando diferentes métodos estão envolvidos na determinação desse parâmetro. Para isso, utilizaram-se 75 amostras de um Argissolo Vermelho-Amarelo distrófico abrúptico da área do Departamento de Solos da Universidade Federal de Santa Maria, representando, em triplicata, cinco profundidades e cinco sistemas de uso e manejo de solo. A CTC efetiva (CTC E foi estimada pelo cloreto de hexamina cobalto (CTC E Cohex e pela soma de cátions Al3+, Ca2+, Mg2+ e K+ (CTC E SB + AlKCl, os três primeiros extraídos por KCl e o último por Mehlich-1; a CTC em pH 7,0 (CTC7 foi estimada por acetato de amônio (CTC7 Metson e pela soma de cátions Ca2+, Mg2+ e K+ e H + Al estimado pelo índice SMP (CTC7 SB + H + AlSMP. Os valores de CTC obtidos pelos diferentes métodos se relacionam entre si, com coeficientes de correlação linear simples acima de 0,93. Os valores de CTC7 Metson são subestimados quando comparados com o método CTC7 (SB + H + AlSMP. Nesse sentido, as contribuições da argila e do COT à CTC7 foram, respectivamente, menores para a CTC7 Metson, 19 e 256 cmol c kg-1, que para a CTC7 (SB + H + AlSMP, 23 e 399 cmol c kg-1. A contribuição dos constituintes de solo depende, então, do cátion extrator e da capacidade de extração dos métodos empregados.The cation exchange capacity (CEC is a physicochemical property dependent on mineral and organic soil constituents. Despite the use of different procedures and extractors the CEC is normally

  2. Contribuição dos constituintes da fração argila de solos subtropicais à área superficial específica e à capacidade de troca catiônica Contribution of clay fraction minerals of subtropical soils to the specific surface area and cation exchange capacity

    Directory of Open Access Journals (Sweden)

    Ivan Granemann de Souza Junior

    2007-12-01

    area (SSA is related to several properties that define the soil physico-chemical behavior. In this research, 23 soil samples developed from different parent materials found in the southern Brazil were used. They were evaluated for the contribution of the main soil constituents to the effective cation exchange capacity (CECe and SSA. The clay fraction minerals were identified by X ray diffraction (XRD and quantified by thermal analysis; the CECe, the SSAt (total by the ethylene glycol monoethyl ether method (EGME, the SSAe (external by the BET-N2 method, and the ASEi (internal by the difference of the values obtained with the two methods. The clay fraction samples were determined before and after the following sequential selective dissolution procedures: removal of organic matter (clay-NaOCl; removal of organic matter and free iron oxides (clay-NaOCl + DCB; removal of kaolinite, gibbsite and low cristalinity aluminosilicate minerals (clay-NaOCl+DCB + NaOH 5 mol L-1. The mineralogy of the clay fraction of the soils varied considerably, as verified by X ray diffraction, thermogravimetric analysis, and SSA and CECe values. For most soils kaolinite is the predominant mineral in the clay fraction, followed by expandable 2:1 clay mineral or iron and aluminum oxihydroxides. SSA and CECe of the natural clay fraction were not correlated due to the occlusion of the clay surface by organic matter. Iron oxide aggregate effects reduced SSAe by 21 %. For the studied samples, the 2:1 clay minerals were present in concentrations varying from 3 to 65 % of the silicate fraction and presented average values of 1.054 mmol c kg-1 and 202 m² g-1 for CECe and SSEt, respectively. SSAi contributed with 58 % of SSAt of the clay fraction, mostly due to 2:1 clay type minerals.

  3. Cátions trocáveis, capacidade de troca de cátions e saturação por bases em solos brasileiros adubados com composto de lixo urbano Exchangeable cations, cation exchange capacity and base saturation in Brazilian soils amended with urban waste compost

    Directory of Open Access Journals (Sweden)

    Cassio Hamilton Abreu Jr.

    2001-12-01

    +, and Na+, on cation exchangeable capacity (CEC, and on base saturation (BS% of 21 acid and 5 alkaline soils. The organic compost (collected at the São Matheus Plant Treatment, São Paulo, Brazil was applied with or without dolomitic lime and mineral fertilizers. For alkaline soils, lime was substituted by gypsum. The experiment was carried out on a split-plot, completely randomized block design with three replicates. The compost application increased the exchangeable content of potassium, calcium, magnesium, and sodium on average of 195%, 200%, 86%, and 1200%, respectively, and elevated the CEC by 42% in acid soils. Consequently the BS% was increased 39%. A lower, but significant, increase on CEC was observed in alkaline soils in response to the compost application. Average CEC and BS% increases were of 8.4% and 2%, respectively. The highest effects on the evaluated soil properties were verified for compost + fertilizer + lime and compost + fertilizer + gypsum applications in acid and alkaline soils, respectively. It is concluded that the use of urban waste compost in agricultural lands is viable only if its effects on chemical properties are properly monitored.

  4. Self-oscillations in large storages of highly mineralized brines

    Science.gov (United States)

    Lyubimova, Tatyana; Lepikhin, Anatoly; Tsiberkin, Kirill; Parshakova, Yanina

    2014-05-01

    One of the stages of the production process at large enrichment plants is settling of aqueous solutions in large technological storages. The present work is devoted to the modeling of hydrodynamic regimes of large storage of highly mineralized brines. The density of brines in these objects depends not only on the content of dissolved macrocomponents, but also on the concentration of fine particulate matter. This leads to the need to consider the dynamics of the suspended sediment under significant density stratification, which greatly complicates the problem. Because of that it is important to develop hydrodynamical models of these objects. A peculiarity of these systems is the possibility of self-oscillatory regimes the mechanism of which is as follows. In warm sunny days, with high solar insolation, the heating of the sediments and bottom water takes place. The bottom water warming and the decrease of its density give rise to flow. The slurry particles composing the sediments are involved in the flow. The heated particles entrained by the flow transfer the heat to the surrounding liquid and increase the absorption of the solar radiation in the volume, which leads to equalization of temperature and convective flow damping. After the particle settling on the bottom the process is repeated. We study the stability of equilibrium of the horizontal liquid layer containing heavy insoluble particles in the presence of evaporation from the free surface and solar radiation absorption by insoluble particles. The time-dependent solution of heat transfer problem is obtained and used for estimate of time of instability onset. It is found that for the layer of saturated brines of potassium chloride of the thickness about 10 m the time for instability onset is about one hour. By using analytical estimates based on the empirical model of turbulence by Prandtl we confirmed the time for the onset of instability and obtained the estimates for the period of self

  5. Interim report for defining brine and oil threats in the Patoka River National Wildlife Refuge [2001

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The following interim report is a list of activities being performed in conjunction with the study of oil brine effects on crayfish in the Patoka River National...

  6. Corrosion studies of A216 grade WCA steel in hydrothermal magnesium-containing brines

    International Nuclear Information System (INIS)

    The US Department of Energy's Salt Repository Project (SRP) is investigating the general corrosion resistance of cast mild steel as a candidate material for waste package containers. Evaluation of this material is being performed at the Pacific Northwest Laboratory in environments simulating expected repository conditions. General corrosion studies of mild steel (ASTM A216 grade WCA) in the as-cast and normalized conditions were conducted in hydrothermal halite-saturated (saturated at ambient temperature) brine environments simulating a ''dissolution'' and an ''inclusion'' brine. Corrosion tests were also performed in brines similar to the inclusion brine but containing magnesium concentrations ranging from 1000 to 30,000 ppM to investigate the effect of magnesium on the corrosion behavior. Corrosion rates of the cast mild steel were found to increase with increasing temperature and with increasing magnesium concentration. Some possible mechanisms that explain the observed behavior are presented. 8 refs., 7 figs., 2 tabs

  7. Antioxidative low molecular weight compounds in marinated herring (Clupea harengus) salt brine

    DEFF Research Database (Denmark)

    Gringer, Nina; Safafar, Hamed; du Mesnildot, Axelle;

    2016-01-01

    This study aimed at unravelling the antioxidative capacity of low molecular weight compounds (LMWC) (peptides, amino acids and phenolic acids) present in salt brines from the marinated herring production. Brines were fractionated into <10 kDa fractions using dialysis and further into 94 fractions...... salt brines contain LMWC holding ABTS-radical scavenging activity, reducing power and iron chelating activity. Generally, a strong correlation between TPC and ABTSradical scavenging was found. In contrast, reducing power and iron chelating activity seemed to be caused by peptides. Protein....../peptide sequencing revealed 1 kDa peptides with the presence of HDFmotif which could be responsible for some of the antioxidant capacity observed in marinated herring salt brine....

  8. Interim report for defining brine and oil threats in the Patoka River National Wildlife Refuge [2002

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The following interim report is a list of activities being performed in conjunction with the study of oil brine effects on crayfish in the Patoka River National...

  9. THE BRINE SHRIMP (ARTEMIA SALINA) LETHALITY OF Brassica oleracea var. capitata

    OpenAIRE

    O. T. TÜZÜN, E. GÜRKAN, S. DOĞANCA, F. HIRLAK,

    2015-01-01

    This work covers up the bio-activities of the five fractions obtained from the ethanolic extract of Brassica oleracea var. capitata (Cruciferae).Key Words: Brassica oleracea var. capitata, Brine shrimp (Artemia salina)

  10. Use of a Brine Shrimp Assay to Study Herbal Teas in the Classroom.

    Science.gov (United States)

    Opler, Annette; Mizell, Rebecca; Robert, Alexander; Cervantes-Cervantes, Miguel; Kincaid, Dwight; Kennelly, Edward J.

    2002-01-01

    Introduces a brine shrimp assay to demonstrate the effects of the biological activity of herbal remedies. Describes two protocols, one using aqueous extracts and the other using methanol extracts. (Contains 21 references.) (YDS)

  11. Brine shrimp lethality and antibacterial activity of extracts from the bark of Schleichera oleosa

    Institute of Scientific and Technical Information of China (English)

    Laxman Pokhrel; Bigyan Sharma; Gan B Bajracharya

    2015-01-01

    Objective: To determine the antibacterial efficacy and brine shrimp toxicity of extracts (hexane, dichloromethane, ethyl acetate, methanol and water) obtained from the bark of Schleichera oleosa. Methods: The powdered bark sample was Soxhlet extracted sequentially in hexanes, dichloromethane, ethyl acetate, methanol and water. Antibacterial evaluation was carried out by following the agar diffusion method and amoxicillin disc was used as a reference. Slightly modified Meyer’s method was used to determine the toxicity of the extracts in brine shrimps. Results: Among the nine bacterial strains tested, the methanolic and aqueous extracts showed promising antibacterial efficacy against Serratia marcescens, Escherarichia coli, Bacillus subtilis and Micrococcus luteus. None of the extracts were found significantly toxic to brine shrimps. Conclusions: Strong antibacterial activity and low brine shrimp toxicity of methanolic and aqueous extracts can provide new antibacterial compounds.

  12. Brine shrimp lethality and antibacterial activity of extracts from the bark of Schleichera oleosa

    Directory of Open Access Journals (Sweden)

    Laxman Pokhrel

    2015-08-01

    Full Text Available Objective: To determine the antibacterial efficacy and brine shrimp toxicity of extracts (hexane, dichloromethane, ethyl acetate, methanol and water obtained from the bark of Schleichera oleosa. Methods: The powdered bark sample was Soxhlet extracted sequentially in hexanes, dichloromethane, ethyl acetate, methanol and water. Antibacterial evaluation was carried out by following the agar diffusion method and amoxicillin disc was used as a reference. Slightly modified Meyer’s method was used to determine the toxicity of the extracts in brine shrimps. Results: Among the nine bacterial strains tested, the methanolic and aqueous extracts showed promising antibacterial efficacy against Serratia marcescens, Escherarichia coli, Bacillus subtilis and Micrococcus luteus. None of the extracts were found significantly toxic to brine shrimps. Conclusions: Strong antibacterial activity and low brine shrimp toxicity of methanolic and aqueous extracts can provide new antibacterial compounds.

  13. Production dynamics of Brine Shrimp (Artemia franciscana) in the San Francisco Bay National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Abundance, stage structure and population dynamics of brine shrimp Artemia franciscana in pond M4 of the San Francisco Bay National Wildlife Refuge were documented...

  14. Bead Evaporator for Complete Water and Salt Recovery from Brine Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A microgravity-compatible Brine Evaporation and Mineralization System (BEMS) is proposed for 100% water recovery from highly contaminated wastewater as well as...

  15. An experimental study of diopside- CO2 -brine interaction

    Science.gov (United States)

    Zhou, Bing; Liu, Li; Ming, Xiaoran; Guo, Yanjun

    2014-05-01

    Diopside is one of the main minerals that consist igneous rock. It is characterized by high content of divalent cations like Ca, Mg, and Fe and relatively fast dissolution rate. These features make it an expected mineral of releasing metal ions for mineral carbonation during the research of mineral trapping of CO2. This study focus on the dissolution amount and micro-scale observing of diopside after the reaction with CO2 and brine under 100, 150, and 200°C. Each of the three experiments are carried out with 2 pieces of diopside (10mm*10mm*4mm) and 500ml Nacl (1mol/L) for 72h, and the pressure inside is 7Mp after injecting of CO2. SEM analysis of the surface of diopside before and after the experiments shows that the degree of corrosion increase with the rising of temperature. The slices of diopside lose 0.8% of its weight at the end of the experiments of 100°C, about 1.8% at 150°C, and about 3.92% at 200°C. Silicon concentrations after reaction are 14.55 mg/L (100°C), 47.02 mg/L (150°C), and 65.32 mg/L (200°C), which also prove the elevated temperature has a positive influence on dissolution of solid. Concentration of calcium and bicarbonate increase with temperature, while magnesium and iron are not. This may due to the heterogeneity of the composition in each piece of solid, or the precipitation of some compounds during the experiments. There are some amorphous compounds are found under SEM, which are mostly consisted of C, O, Na, Mg, Si, and Ca. A simple numerical simulation of CO2-diopside-brine interaction is carried out by TOUGHREACT. The setting of parameters are based on the experiments. Diopside reacts with 1mol/L Nacl under the CO2 partial pressure of 10Mp and the temperature keeps 100°C. The results present that the volume percent of precipitated carbonates (calcite and magnesite) reaches 1.23% after 100 years, which means 1m3 diopside could capture 16.76kg CO2 after 100 years by the means of mineral carbonation. This study reveals the

  16. Field evaluation of membrane distillation technologies for desalination of highly saline brines

    OpenAIRE

    Minier-Matar, J.; Hussain, A; Janson, A; Benyahia, F.; Adham, S.

    2014-01-01

    Membrane distillation (MD) is a hybrid thermal-membrane desalination process that uses low-grade waste heat and hydrophobic membrane to produce high quality distillate. The MD process can treat highly saline brines that other conventional desalination processes cannot treat. These unique features of the MD process make it an ideal candidate to desalinate concentrated brines from thermal desalination plants to augment fresh water production from existing facilities. A consortium consisting of ...

  17. Study of thermal-gradient-induced migration of brine inclusions in salt. Final report

    International Nuclear Information System (INIS)

    Natural salt deposits, which are being considered for high-level waste disposal, contain a small volume fraction of water in the form of brine inclusions distributed throughout the salt. Radioactive decay heating of the nuclear wastes will impose a temperature gradient on the surrounding salt which mobilizes the brine inclusions. Inclusions filled completely with brine (the all-liquid inclusions) migrate up the temperature gradient and eventually accumulate brine near the buried waste forms. The brine may slowly corrode or degrade the waste forms, which is undesirable. Therefore it is important to consider the migration of brine inclusions in salt under imposed temperature gradients to properly evaluate the performance of a future salt repository for nuclear wastes. The migration velocities of the inclusions were found to be dependent on temperature, temperature gradient, and inclusion shape and size. The velocities were also dictated by the interfacial mass transfer resistance at brine/solid interface. This interfacial resistance depends on the dislocation density in the crystal, which in turn, depends on the axial compressive loading of the crystal. At low axial loads, the dependence between the velocity and temperature gradient is nonlinear. At high axial loads, the interfacial resistance is reduced and the migration velocity depends linearly on the temperature gradient. All-liquid inclusions filled with mixed brines were also studied. For gas-liquid inclusions, helium, air and argon were compared. Migration studies were also conducted on single crystallites of natural salt as well as in polycrystalline natural salt samples. The behavior of the inclusions at large-ange grain boundaries was observed

  18. BRINE SHRIM LETHALITY BIOASSAY OF METHANOLIC CRUDE EXTRACTS OF TERMINALIA ARJUNA

    OpenAIRE

    Maruf Anayet and Mohammad Musarraf Hussain

    2012-01-01

    The aim of this work is to determine the cytotoxic activities of Terminalia arjuna (Family: Combretaceae) by brine shrimp lethality bioassay. The leaves of Terminalia arjuna were extracted with methanol and the methanolic extract was fractionated into three fractions by using organic solvents like n-hexane, ethyl acetate and chloroform. The n-hexane, ethyl acetate and chloroform soluble fractions of methanolic crude extract were screened for antitumor properties using brine shrimp lethality b...

  19. Brine shrimp lethality and acute oral toxicity studies on Swietenia mahagoni (Linn.) Jacq. seed methanolic extract

    OpenAIRE

    Geethaa Sahgal; Surash Ramanathan; Sreenivasan Sasidharan; Mohd. Nizam Mordi; Sabariah Ismail; Sharif Mahsufi Mansor

    2010-01-01

    Background: The seeds of Swietenia mahagoni have been applied in folk medicine for the treatment of hypertension, diabetes, malaria, amoebiasis, cough, chest pain, and intestinal parasitism. Here we are the first to report on the toxicity of the Swietenia mahagoni crude methanolic (SMCM) seed extract. Methods: SMCM seed extract has been studied for its brine shrimp lethality and acute oral toxicity, in mice. Results: The brine shrimp lethality bioassay shows a moderate cytotoxicity at high co...

  20. Comparing the potential for dispersal via waterbirds of a native and an invasive brine shrimp

    OpenAIRE

    Sánchez, Marta I.; Hortas, F.; Figuerola, Jordi; Green, Andy J.

    2012-01-01

    Migratory waterbirds are likely to have a major role in the spread of many exotic aquatic invertebrates by passive dispersal. However, in the field, this has so far only been confirmed in the case of the American brine shrimp Artemia franciscana, which is spreading quickly around the Mediterranean region. We compared experimentally the capacity of A. franciscana and the native brine shrimp Artemia parthenogenetica to disperse via migratory shorebirds. After Artemia resting eggs (cysts) were f...

  1. A comparison between two brine shrimp assays to detect in vitro cytotoxicity in marine natural products

    OpenAIRE

    Pérez Pilar; Hernández-Inda Zaira L; Carballo José; García-Grávalos María D

    2002-01-01

    Abstract Background The brine shrimp lethality assay is considered a useful tool for preliminary assessment of toxicity. It has also been suggested for screening pharmacological activities in plant extracts. However, we think that it is necessary to evaluate the suitability of the brine shrimp methods before they are used as a general bio-assay to test natural marine products for pharmacological activity. Material and Methods The bioactivity of the isopropanolic (2-PrOH) extracts of 14 specie...

  2. Acute toxicity, brine shrimp cytotoxicity, anthelmintic and relaxant potentials of fruits of Rubus fruticosus Agg

    OpenAIRE

    Ali, Niaz; Aleem, Umer; Ali Shah, Syed Wadood; Shah, Ismail; Junaid, Muhammad; Ahmed, Ghayour; Ali, Waqar; Ghias, Mehreen

    2013-01-01

    Background Rubus fruticosus is used in tribal medicine as anthelmintic and an antispasmodic. In the current work, we investigated the anthelmintic and antispasmodic activities of crude methanol extract of fruits of R. fruticosus on scientific grounds. Acute toxicity and brine shrimp cytotoxicity activity of the extract were also performed. Methods Acute toxicity study of crude methanol extract of R. fruticosus was performed on mice. In vitro Brine shrimp cytotoxicity assay was performed on sh...

  3. Study of thermal-gradient-induced migration of brine inclusions in salt. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Olander, D.R.

    1984-08-01

    Natural salt deposits, which are being considered for high-level waste disposal, contain a small volume fraction of water in the form of brine inclusions distributed throughout the salt. Radioactive decay heating of the nuclear wastes will impose a temperature gradient on the surrounding salt which mobilizes the brine inclusions. Inclusions filled completely with brine (the all-liquid inclusions) migrate up the temperature gradient and eventually accumulate brine near the buried waste forms. The brine may slowly corrode or degrade the waste forms, which is undesirable. Therefore it is important to consider the migration of brine inclusions in salt under imposed temperature gradients to properly evaluate the performance of a future salt repository for nuclear wastes. The migration velocities of the inclusions were found to be dependent on temperature, temperature gradient, and inclusion shape and size. The velocities were also dictated by the interfacial mass transfer resistance at brine/solid interface. This interfacial resistance depends on the dislocation density in the crystal, which in turn, depends on the axial compressive loading of the crystal. At low axial loads, the dependence between the velocity and temperature gradient is nonlinear. At high axial loads, the interfacial resistance is reduced and the migration velocity depends linearly on the temperature gradient. All-liquid inclusions filled with mixed brines were also studied. For gas-liquid inclusions, helium, air and argon were compared. Migration studies were also conducted on single crystallites of natural salt as well as in polycrystalline natural salt samples. The behavior of the inclusions at large-ange grain boundaries was observed.

  4. New aspects of the use of inert diets for high density culturing of brine shrimp

    OpenAIRE

    Dobbeleir, J.; Adam, N.(Princeton University, Princeton, U.S.A); Bossuyt, E.; Bruggeman, E.; Sorgeloos, P

    1980-01-01

    Brine shrimp being non-selective filter-feeders, cheap agricultural waste products should be evaluated as potential food sources for their controlled mass culturing. Preliminary results of screening tests performed with wheat bran, soybean meal , rice bran and whey powder in culturing systems of various size are reported. Wheat bran appears to be unsuitable as monodiet for brine shrimp. The other products tested support good growth although specific precautions have to be taken with some food...

  5. Effects of brine addition on effluent toxicity and marine toxicity identification evaluation (TIE) manipulations

    Energy Technology Data Exchange (ETDEWEB)

    Ho, K.T.; Burgess, R.M. (Environmental Protection Agency, Narragansett, RI (United States)); Mitchell, K. (Xavier Univ. of Louisiana, New Orleans, LA (United States). Biology Dept.); Zappala, M. (Univ. of Rhode Island, Kingston, RI (United States))

    1995-02-01

    Little information is available concerning the effect of salinity adjustment on effluent storage and toxicity identification evaluation (TIE) performance. These factors are important for accurate assessments of potential toxicity to marine organisms. The objective of this study was to determine (a) the effect of salinity adjustment using hypersaline brine on the toxicity of effluents stored up to 40 d, and (b) to determine the effect of salinity adjustment on TIE manipulations. Changes in effluent toxicity over time were examined by using a municipal and an industrial effluent. A toxicity time series was performed for 16 d for the industrial effluent and 40 d for the municipal effluent. Toxicity was measured with modified 48-h acute Mysidopsis bahia and Menidia beryllina tests. Results indicate that, compared to day 0 test results, effluent stored with brine had fewer significant changes in toxicity than did effluent stored without brine. To determine the effects of brine addition on TIE manipulations, the authors conducted a series of manipulations in which one aliquot of an effluent had brine added prior to the TIE manipulations and the other aliquot had brine added after the TIE manipulation. The manipulations conducted were EDTA addition, sodium thiosulfate addition, C[sub 18] extraction, aeration, filtration, and graduated pH manipulations. Toxicity was measured with the modified 48-h acute mysid test. Addition of brine had no effect on the outcome of TIE manipulations. They have concluded that it is operationally easier to add brine as soon as possible after sampling and that effluent tests should be conducted as soon as practical.

  6. Antagonism Between Osmophilic Lactic Acid Bacteria and Yeasts in Brine Fermentation of Soy Sauce

    OpenAIRE

    Noda, Fumio; HAYASHI, Kazuya; Mizunuma, Takeji

    1980-01-01

    Brine fermentation by osmophilic lactic acid bacteria and yeasts for long periods of time is essential to produce a good quality of shoyu (Japanese fermented soy sauce). It is well known that lactic acid fermentation by osmophilic lactic acid bacteria results in the depression of alcoholic fermentation by osmophilic yeasts, but the nature of the interaction between osmophilic lactic acid bacteria and yeasts in brine fermentation of shoyu has not been revealed. The inhibitory effect of osmophi...

  7. Exact Regenerating Codes for Distributed Storage

    CERN Document Server

    V., Rashmi K; Kumar, P Vijay; Ramachandran, Kannan

    2009-01-01

    Erasure coding techniques are used to increase the reliability of distributed storage systems while minimizing storage overhead. The bandwidth required to repair the system after a node failure also plays a crucial role in the system performance. In [1] authors have shown that a tradeoff exists between storage and repair bandwidth. They also have introduced the scheme of regenerating codes which meet this tradeoff. In this paper, a scheme of Exact Regenerating Codes is introduced, which are regenerating codes with an additional property of regenerating back the same node upon failure. For the minimum bandwidth point, which is suitable for applications like distributed mail servers, explicit construction for exact regenerating codes is provided. A subspace approach is provided, using which the necessary and sufficient conditions for a linear code to be an exact regenerating code are derived. This leads to the uniqueness of our construction. For the minimum storage point which suits applications such as storage...

  8. Dendrite Injury Triggers DLK-Independent Regeneration

    Directory of Open Access Journals (Sweden)

    Michelle C. Stone

    2014-01-01

    Full Text Available Axon injury triggers regeneration through activation of a conserved kinase cascade, which includes the dual leucine zipper kinase (DLK. Although dendrites are damaged during stroke, traumatic brain injury, and seizure, it is not known whether mature neurons monitor dendrite injury and initiate regeneration. We probed the response to dendrite damage using model Drosophila neurons. Two larval neuron types regrew dendrites in distinct ways after all dendrites were removed. Dendrite regeneration was also triggered by injury in adults. Next, we tested whether dendrite injury was initiated with the same machinery as axon injury. Surprisingly, DLK, JNK, and fos were dispensable for dendrite regeneration. Moreover, this MAP kinase pathway was not activated by injury to dendrites. Thus, neurons respond to dendrite damage and initiate regeneration without using the conserved DLK cascade that triggers axon regeneration.

  9. Nuclear waste repository simulation experiments (brine migration), Asse Mine of the Federal Republic of Germany: Quarterly brine migration data report, October--December 1985

    International Nuclear Information System (INIS)

    The tenth brine migration data report describes experiments simulating a nuclear waste repository at the 800-m (2624-ft) level of the Asse Salt Mine in the Federal Republic of Germany from May 1983 through December 1985. This report describes the test equipment, the Asse Salt Mine, and the pretest properties of the salt in the test gallery. This report includes test data for 31 months of operations on brine migration rates, borehole pressure, salt temperatures and thermomechanical behavior of the salt. 3 refs., 118 figs., 93 tabs

  10. Quarterly brine migration data report, May-September 1983: Nuclear Waste Repository simulation experiments (brine migration), Asse Mine of the Federal Republic of Germany

    International Nuclear Information System (INIS)

    The first quarterly brine migration data report describes experiments simulating a nuclear waste repository at the 800-m (2624-ft) level of the Asse Salt Mine in the Federal Republic of Germany from May 1983 through September 1983. This report describes the test equipment, the Asse Salt Mine, and the pretest properties of the salt in the test gallery. This report also includes test data for the first 4 months of operations on brine migration rates, borehole pressure, salt temperatures, and thermomechanical behavior of the salt. The duration of the experiments will be approximately 2 years, ending in December 1985. 83 figs., 55 tabs

  11. Regeneration of Pinus pinaster forests after wildfire

    OpenAIRE

    Castro, José; Bento, João Manuel; Rego, Francisco

    1990-01-01

    Wildfires are of extreme importance in Pinus pinaster forests of central and northern Portugal. Reforestation plans after wildfires are generally made without consideration for the possibility of natural regeneration. This paper addresses the question of the factors responsible for the occurrence of natural regeneration and concludes that litter accumulation, rock outcrops, slope, aspect, harvest, fire characteristics, and stand age are well related to the regeneration observed. Limitations o...

  12. Managing reindeer lichen during forest regeneration procedures

    OpenAIRE

    Roturier, Samuel

    2009-01-01

    In northern Sweden, conventional forest regeneration procedures applied in modern commercial forestry can disturb terricolous lichen (Cladina spp.) pastures. This has become a source of conflicts with Sámi reindeer herders. The overall aim of this thesis was to investigate forest regeneration strategies that may minimise the disturbance to, and promote the regeneration of, reindeer lichen pastures. The Sámi herders’ practices and knowledge related to the lichen resources were also analysed. E...

  13. A review of degradation modes of low carbon steel in brine environments

    International Nuclear Information System (INIS)

    A literature search was conducted to review information on degradation modes of low carbon steel in brine solutions. A computer search was used to obtain articles from 1970 to present while a manual search was conducted for articles published prior to 1970. The published articles and reports indicated that uniform corrosion occurred in sea water, geothermal brines and simulated repository brines. The uniform corrosion rate increased with decreasing pH, increasing oxygen contest of brine and increasing temperature. Pitting of low carbon steel in brine solutions was related to scale formation due to presences of sulfur and heavy metal ions or mill scale present prior to exposure. Low carbon steel did not appear to be susceptible to stress corrosion cracking, but data was limited. The presence of anaerobic bacteria greatly increased the rate of corrosion of low carbon steel as compared to sterile conditions. If sufficient hydrogen is present, low carbon steel could fail due to hydrogen embrittlement in brine solutions. However, this is an area where experimental work needs to be done under more specific conditions related to salt repositories. Corrosion fatigue and stray current corrosion require specific conditions to occur which can be avoided during waste storage and were there fore not addressed. Also, galvanic effects were not addressed as it will be possible to minimize galvanic effects by design. 226 refs., 4 tabs

  14. About effect of magnesium chloride and some ions in brines on boron coprecipitation by iron hydroxide

    International Nuclear Information System (INIS)

    Studies were made of conditions of precipitation of boron with iron hydroxide from the brines of the mixing zone of the Kara-Bogaz Gol, the mother liquor after the precipitation of potassium salts and artificial manganese chloride solutions at a temperature of 7-45 dee C. The maximum extraction of boron from the brines investigated is observed both in a weakly acid and a weakly alkaline medium. The extraction intensity increases drastically in the range of the maximum with an increase in brine concentration. The anions Cl-, SO42-, and HCO3- present in the brines produce the maximum effect on boron precipitation at a definite pH. This effect depends on the nature of the anions and their ratio in the brine. With a rise in temperature the degree of boron precipitations from the magnesium chloride brine and the precipitate capacity increase as a result of the release of active magnesium hydroxide. When the ratio of Fe2O3 to 100 ml initial solution changes towards increase in precipitating agent at a constant temperature, the precipitate capacity for B2O3 decreases

  15. Chemical Analyses of Geothermal Waters and Strategic Petroleum Reserve Brines for Strategic and Precious Metals

    Energy Technology Data Exchange (ETDEWEB)

    Harrar, Jackson E.; Raber, Ellen

    1983-06-01

    Water form seven hydrothermal-geothermal, one geopressured-geothermal, and six Strategic Petroleum Reserve wells have been surveyed for twelve metals of special strategic and economic importance using trace chemical analysis techniques. The elements sought were Cr, Co, Mn, Ta, Sn, V, Nb, Li, Sr, Pt, Au, and Ag. Platinum was found at a concentration of ~50 ppb in a brine from the Salton Sea geothermal area. Brine from this region, as has been known from previous studies, is also rich in Li, Sr, and Mn. Higher concentrations (~900) of Sr are found in the high-salinity geopressured brines. None of the fluids contained interesting concentrations of the other metals. Good recovery of precious metals at sub-ppm concentrations from synthetic high salinity brines was achieved using Amborane resin, but similar recovery in the laboratory using real brines could not be demonstrated. Several analytical techniques were compared in sensitivity for the determination of the precious metals; neutron activation analysis with carrier separation is the best for gold and platinum in geothermal brines. (DJE-2005)

  16. Evolution of Hydrate Dissociation by Warm Brine Stimulation Combined Depressurization in the South China Sea

    Directory of Open Access Journals (Sweden)

    Zhao-Yang Chen

    2013-10-01

    Full Text Available To evaluate the gas production performance of the hydrate accumulations in the South China Sea, a numerical simulation with warm brine stimulation combined depressurization has been conducted. A dual horizontal well system is considered as the well configuration in this work. In order to reduce energy input and improve energy utilization, warm brine (50 °C is injected into the reservoir for hydrate dissociation. The effect of the intrinsic permeability of the hydrate reservoir, the salinity and the temperature of the injected brine to gas hydrate exploitation have been investigated. The numerical simulation results indicate that the average gas production rate Qavg is about 1.23 ´ 105 ST m3/day for the entire hydrate deposit, which has the same order of magnitude compared with the commercially viable production rate. The injected brine can be pumped out from the upper production well directly after the hydrate between the two wells is dissociated completely. Thus, the effective region of heat and inhibitor stimulation is limited. The sensitivity analyses indicate that the dissociation rate of hydrate can be enhanced by increasing the temperature of the injected brine and raising the salinity of the injected brine. The parametric study of permeability shows that the hydrate of the reservoir with the larger permeability has a higher dissociation rate.

  17. Brine Sampling and Evaluation Program 1992--1993 report and summary of BSEP data since 1982

    International Nuclear Information System (INIS)

    This report is the last one that is currently scheduled in the sequence of reports of new data, and therefore, also includes summary comments referencing important data obtained by BSEP since 1983. These BSEP activities document and investigate the origins, hydraulic characteristics, extent, and composition of brine occurrences in the Permian Salado Formation and seepage of that brine into the excavations at the (WIPP) Waste Isolation Pilot Plant. A project concern is that enough brine might be present after sealing and closure to generate large quantities of hydrogen gas by corroding the metal in the waste drums and waste inventory. This report describes progress made during the calendar years 1992 and 1993 and focuses on four major areas: (1) monitoring of brine inflow, e.g., measuring brines recovered from holes drilled downward from the underground drifts (downholes), upward from the underground drifts (upholes), and from subhorizontal holes from the underground drifts; (2) observations of weeps in the Air Intake Shaft (AIS); (3) further characterization of brine geochemistry; and (4) additional characterization of the hydrologic conditions in the fractured zone beneath the excavations

  18. Comparison of the Wear Behavior of UHMWPE Lubricated by Human Plasma and Brine

    Institute of Scientific and Technical Information of China (English)

    WANG Shi-bo; GE Shi-rong; NORM Gitis; MICHAEL Vinogradov; XIAO Jun

    2007-01-01

    The effect of plasma and brine lubricants on the friction and wear behavior of UHMWPE were studied by using the geometry of a Si3N4 ball sliding on a UHMWPE disc under patterns of uni-directional reciprocation and bi-directional sliding motions. The worn surface and wear particles produced in these two lubricants were analyzed. Sliding motion pattern affected the friction coefficients lubricated with plasma, while seldom affected that lubricated with brine. UHMWPE lubricated with plasma showed about half of the wear rate of that lubricated with brine. The two rates were 0.75 pg/m and 2.19 pg/m for the two motion patterns, respectively. However, wear particles generated in plasma included a greater amount of small particles, compared to that in brine. In uni-directional reciprocation, the main wear mechanism is ploughing both in plasma and in brine. In bi-directional sliding modes, the significant characteristic is ripples on the worn surface in plasma, while there are oriented fibers on the worn surface in brine.

  19. Brine Sampling and Evaluation Program 1992--1993 report and summary of BSEP data since 1982

    Energy Technology Data Exchange (ETDEWEB)

    Deal, D.E.; Abitz, R.J. [I. T. Corp., Carlsbad, NM (United States); Belski, D.S. [USDOE Albuquerque Operations Office, Carlsbad, NM (United States). Waste Isolation Pilot Plant Project Office

    1995-04-01

    This report is the last one that is currently scheduled in the sequence of reports of new data, and therefore, also includes summary comments referencing important data obtained by BSEP since 1983. These BSEP activities document and investigate the origins, hydraulic characteristics, extent, and composition of brine occurrences in the Permian Salado Formation and seepage of that brine into the excavations at the (WIPP) Waste Isolation Pilot Plant. A project concern is that enough brine might be present after sealing and closure to generate large quantities of hydrogen gas by corroding the metal in the waste drums and waste inventory. This report describes progress made during the calendar years 1992 and 1993 and focuses on four major areas: (1) monitoring of brine inflow, e.g., measuring brines recovered from holes drilled downward from the underground drifts (downholes), upward from the underground drifts (upholes), and from subhorizontal holes from the underground drifts; (2) observations of weeps in the Air Intake Shaft (AIS); (3) further characterization of brine geochemistry; and (4) additional characterization of the hydrologic conditions in the fractured zone beneath the excavations.

  20. Emerin increase in regenerating muscle fibers

    Directory of Open Access Journals (Sweden)

    S Squarzoni

    2009-06-01

    Full Text Available The fate of emerin during skeletal muscle regeneration was investigated in an animal model by means of crush injury. Immunofluorescence, immunoblotting and mRNA analysis demonstrated that emerin level is increased in regenerating rat muscle fibers with respect to normal mature myofibers. This finding suggests an involvement of emerin during the muscle fiber regeneration process, in analogy with its reported involvement in muscle cell differentiation in vitro. The impairment of skeletal muscle physiological regeneration or reorganization could be a possible pathogenetic mechanism for Emery Dreifuss muscular dystrophy.

  1. Plant regeneration: cellular origins and molecular mechanisms.

    Science.gov (United States)

    Ikeuchi, Momoko; Ogawa, Yoichi; Iwase, Akira; Sugimoto, Keiko

    2016-05-01

    Compared with animals, plants generally possess a high degree of developmental plasticity and display various types of tissue or organ regeneration. This regenerative capacity can be enhanced by exogenously supplied plant hormones in vitro, wherein the balance between auxin and cytokinin determines the developmental fate of regenerating organs. Accumulating evidence suggests that some forms of plant regeneration involve reprogramming of differentiated somatic cells, whereas others are induced through the activation of relatively undifferentiated cells in somatic tissues. We summarize the current understanding of how plants control various types of regeneration and discuss how developmental and environmental constraints influence these regulatory mechanisms. PMID:27143753

  2. Actinide Biocolloid Formation in Brine by Halophilic Bacteria

    International Nuclear Information System (INIS)

    We examined the ability of a halophilic bacterium (WFP 1A) isolated from the Waste Isolation Pilot Plant (WIPP) site to accumulate uranium in order to determine the potential for biocolloid facilitated actinide transport. The bacterial cell Surface functional groups involved in the complexation of the actinide were determined by titration. Uranium, added as uranyl nitrate, was removed from solution at pH 5 by cells but at pH 7 and 9 very little uranium was removed due to its limited volubility. Although present as soluble species, uranyl citrate at pH 5, 7, and 9, and uranyl carbonate at pH 9 were not removed by the bacterium because they were not bioavailable due to their neutral or negative charge. Addition of uranyl EDTA to brine at pH 5, 7, and 9 resulted in the immediate precipitation of U. Transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS) analysis revealed that uranium was not only associated with the cell surface but also accumulated intracellulary as uranium-enriched granules. Extended X-ray absorption fine structure (EXAFS) analysis, of the bacterial cells indicated the bulk sample contained more than one uranium phase. Nevertheless these results show the potential for the formation of actinide bearing bacterial biocolloids that are strictly regulated by the speciation and bioavailability of the actinide

  3. [Regeneration of planarians: experimental object].

    Science.gov (United States)

    Sheĭman, I M; Kreshchenko, I D

    2015-01-01

    We discuss the expediency of using invertebrates, such as flatworms and planarians, as experimental objects. Free-living planarian flatworms (phylum Platyhelminthes, class Turbellaria) are invertebrate animals in which a bilateral symmetry appears for the first time in evolution and organs and tissues form. As the highest ecological link of the food chain--predators--these animals are characterized by a set of behavioral reactions controlled by a differentiated central nervous system. Planarians have unsurpassed ability to regenerate lost or damaged body parts. Owing to the ease of their breeding and their convenience for manipulations, these animals are used to study the influence of chemical and physical factors on the processes of life, growth, and reproduction. Currently, planarians are recognized as a model for biological research in the field of regeneration, stem cell biology, study of their proliferation and differentiation, as well as the regulatory mechanisms of morphogenetic processes. The genome of the planarian Schmidtea mediterranea was fully sequenced, which opened up the opportunity to work with this object at the molecular biological level. Furthermore, planarians are used in neurobiological and toxicological studies, in studying the evolutionary aspects of centralization of the nervous system, mechanisms of muscle contraction, and in the development of new antiparasitic drugs. This review aims to demonstrate the relevance and diversity of research conducted on simple biological objects--planarians--to awider audience to show the historical continuity of these studies and their wide geographical distribution and to focus on the studies carried out in Russia, which, as a rule, are not included in the foreign reviews on planarian regeneration. PMID:25898529

  4. The Amount of Regenerated Heat Inside the Regenerator of a Stirling Engine

    Directory of Open Access Journals (Sweden)

    J. Škorpík

    2008-01-01

    Full Text Available The paper deals with analytical computing of the regenerated heat inside the regenerator of a Stirling engine. The total sum of the regenerated heat is constructed as a function of the crank angle in the case of Schmidt’s idealization. 

  5. The Amount of Regenerated Heat Inside the Regenerator of a Stirling Engine

    OpenAIRE

    J. Škorpík

    2008-01-01

    The paper deals with analytical computing of the regenerated heat inside the regenerator of a Stirling engine. The total sum of the regenerated heat is constructed as a function of the crank angle in the case of Schmidt’s idealization. 

  6. The urban question and regeneration

    OpenAIRE

    Bianchi A.

    2014-01-01

    The «urban regeneration» which is emerging today in Italy was founded in the wake of a line which has risen in Great Britain since the mid-70s of the twentieth century. Among the many European experiences, those of Glasgow and Bilbao are cited, where between the middle and the end of the '80s economic, social and cultural processes have triggered related to living within the cities, which have changed not only their physical appearance but also their functionality and the same structure. More...

  7. Bone regeneration and stem cells

    DEFF Research Database (Denmark)

    Arvidson, K; Abdallah, B M; Applegate, L A;

    2011-01-01

    This invited review covers research areas of central importance for orthopedic and maxillofacial bone tissue repair, including normal fracture healing and healing problems, biomaterial scaffolds for tissue engineering, mesenchymal and fetal stem cells, effects of sex steroids on mesenchymal stem...... cells, use of platelet rich plasma for tissue repair, osteogenesis and its molecular markers. A variety of cells in addition to stem cells, as well as advances in materials science to meet specific requirements for bone and soft tissue regeneration by addition of bioactive molecules, are discussed....

  8. Regeneration performance of CO2-rich solvents by using membrane vacuum regeneration technology: Relationships between absorbent structure and regeneration efficiency

    International Nuclear Information System (INIS)

    Highlights: ► MVR may be viable to successfully use less valuable heat to replace high grade steam. ► Increasing OH and amine groups will increase the regeneration efficiency. ► Absorbents with a four carbon chain length will be more attractive to MVR. ► Amino acid salts will be more appropriate for MVR. ► HRM conducted at ambient pressure and low temperature is inferior to MVR. -- Abstract: In order to give a better understanding for the selection of suitable absorbents for the novel membrane vacuum regeneration technology (MVR) which has the potential to reduce CO2 energy requirement by utilizing the waste heat or low-grade energy, an experimental study to determine the relationships between chemical structure and vacuum regeneration behavior of CO2 absorbents at 70 °C and 10 kPa was performed. Eleven typical absorbents with different functional groups in their chemical structures were investigated in terms of vacuum regeneration efficiencies. Results showed that the regeneration efficiency decreased with an increase of number of activated hydrogen atom in amine group and decreased with the number of hydroxyl group. Especially, more attention should be paid to these alkanolamines with one hydrogen atom in amine group and two or more hydroxyl groups in the structures due to their better comprehensive performance in regeneration, absorbent loss and CO2 absorption aspects. Increasing the carbon chain length and amine groups in the absorbent structure contributed to the improvement of regeneration performance and reduction of absorbent volatile loss. These absorbents with a four carbon chain length bonded at amine group might be more attractive to MVR. Furthermore, polyamines were superior to monoamines in terms of higher regeneration efficiencies and lower absorbent losses. Additionally, the individual effects of the potassium carboxylate group and hydroxymethylene group were also compared in this study. Results showed that amino acid salts were more

  9. Liver Development, Regeneration, and Carcinogenesis

    Directory of Open Access Journals (Sweden)

    Janet W. C. Kung

    2010-01-01

    Full Text Available The identification of putative liver stem cells has brought closer the previously separate fields of liver development, regeneration, and carcinogenesis. Significant overlaps in the regulation of these processes are now being described. For example, studies in embryonic liver development have already provided the basis for directed differentiation of human embryonic stem cells and induced pluripotent stem cells into hepatocyte-like cells. As a result, the understanding of the cell biology of proliferation and differentiation in the liver has been improved. This knowledge can be used to improve the function of hepatocyte-like cells for drug testing, bioartificial livers, and transplantation. In parallel, the mechanisms regulating cancer cell biology are now clearer, providing fertile soil for novel therapeutic approaches. Recognition of the relationships between development, regeneration, and carcinogenesis, and the increasing evidence for the role of stem cells in all of these areas, has sparked fresh enthusiasm in understanding the underlying molecular mechanisms and has led to new targeted therapies for liver cirrhosis and primary liver cancers.

  10. Progenitor Cells and Podocyte Regeneration

    Science.gov (United States)

    Shankland, Stuart J.; Pippin, Jeffrey W.; Duffield, Jeremy S.

    2014-01-01

    The very limited ability of adult podocytes to proliferate in vivo is clinically significant because: podocytes form a vascular barrier which is functionally critical to the nephron; podocyte hypoplasia is a characteristic of disease; and inadequate regeneration of podocytes is a major cause of persistent podocyte hypoplasia. Excessive podocyte loss or inadequate replacement leads to glomerulosclerosis in many progressive kidney diseases. Thus, restoration of podocyte cell density is almost certainly reliant on regeneration by podocyte progenitors. However such putative progenitors have remained elusive until recently. In this review we describe the developmental processes leading to podocyte and parietal epithelial cell (PEC) formation during glomerulogenesis. We compare evidence that in normal human kidneys PECs expressing ‘progenitor’ markers CD133 and CD24 can differentiate into podocytes in vitro and in vivo with evidence from animal models suggesting a more limited role of PEC-capacity to serve as podocyte progenitors in adults. We will highlight tantalizing new evidence that specialized vascular wall cells of afferent arterioles including those which produce renin in healthy kidney, provide a novel local progenitor source of new PECs and podocytes in response to podocyte hypoplasia in the adult, and draw comparisons with glomerulogenesis. PMID:25217270

  11. Microwave Regenerable Air Purification Device

    Science.gov (United States)

    Atwater, James E.; Holtsnider, John T.; Wheeler, Richard R., Jr.

    1996-01-01

    The feasibility of using microwave power to thermally regenerate sorbents loaded with water vapor, CO2, and organic contaminants has been rigorously demonstrated. Sorbents challenged with air containing 0.5% CO2, 300 ppm acetone, 50 ppm trichloroethylene, and saturated with water vapor have been regenerated, singly and in combination. Microwave transmission, reflection, and phase shift has also been determined for a variety of sorbents over the frequency range between 1.3-2.7 GHz. This innovative technology offers the potential for significant energy savings in comparison to current resistive heating methods because energy is absorbed directly by the material to be heated. Conductive, convective and radiative losses are minimized. Extremely rapid heating is also possible, i.e., 1400 C in less than 60 seconds. Microwave powered thermal desorption is directly applicable to the needs of Advance Life Support in general, and of EVA in particular. Additionally, the applicability of two specific commercial applications arising from this technology have been demonstrated: the recovery for re-use of acetone (and similar solvents) from industrial waste streams using a carbon based molecular sieve; and the separation and destruction of trichloroethylene using ZSM-5 synthetic zeolite catalyst, a predominant halocarbon environmental contaminant. Based upon these results, Phase II development is strongly recommended.

  12. Extracellular Control of Limb Regeneration

    Science.gov (United States)

    Calve, S.; Simon, H.-G.

    Adult newts possess the ability to completely regenerate organs and appendages. Immediately after limb loss, the extracellular matrix (ECM) undergoes dramatic changes that may provide mechanical and biochemical cues to guide the formation of the blastema, which is comprised of uncommitted stem-like cells that proliferate to replace the lost structure. Skeletal muscle is a known reservoir for blastema cells but the mechanism by which it contributes progenitor cells is still unclear. To create physiologically relevant culture conditions for the testing of primary newt muscle cells in vitro, the spatio-temporal distribution of ECM components and the mechanical properties of newt muscle were analyzed. Tenascin-C and hyaluronic acid (HA) were found to be dramatically upregulated in the amputated limb and were co-expressed around regenerating skeletal muscle. The transverse stiffness of muscle measured in situ was used as a guide to generate silicone-based substrates of physiological stiffness. Culturing newt muscle cells under different conditions revealed that the cells are sensitive to both matrix coating and substrate stiffness: Myoblasts on HA-coated soft substrates display a rounded morphology and become more elongated as the stiffness of the substrate increases. Coating of soft substrates with matrigel or fibronectin enhanced cell spreading and eventual cell fusion.

  13. Regeneration of Pelargonium in vitro

    Directory of Open Access Journals (Sweden)

    Agnieszka Wojtania

    2013-12-01

    Full Text Available Pelargonium sp. has been a subject of numerous studies to deterimine the effec tiveness of in vitro techniques to produce a large number of pathogen-free plants. Regeneration of pelargonium plants from the different initial explants as well via organogenesis as via somatic embryogenesis has been obtained. The most effective adventitious shoot formation has been achieved from shoot tips and axillary buds using cytokinin or cytokinin/auxin combinations. Leaf explants, whose general have lower organogenic potency, regenerate better in the presence of thidiazuron. This growth regulator stimulate the somatic embryos production from hypocotyl and cotyledone explants too. The main problem in tissue culture propagation of Pelargonium has been the high tendency to formation of vigorously growing callus with low organogenic potency and rapid senescence of cultures. Moreover, the significant differen ces in requirements to the medium composition (minerals, organic compounds and growth regulators between Pelargonium cultivars has been observed. This makes difficult to develop an universaI method of Pelargonium micropropagation.

  14. Long-term monitoring of arsenic, copper, selenium, and other elements in Great Salt Lake (Utah, USA) surface water, brine shrimp, and brine flies.

    Science.gov (United States)

    Adams, William J; DeForest, David K; Tear, Lucinda M; Payne, Kelly; Brix, Kevin V

    2015-03-01

    This paper presents long-term monitoring data for 19 elements with a focus on arsenic (As), copper (Cu), and selenium (Se), in surface water (2002-2011), brine shrimp (2001-2011), and brine flies (1995-1996) collected from Great Salt Lake (GSL, Utah, USA). In open surface waters, mean (±standard deviation [SD]; range; n) As concentrations were 112 (±22.1; 54.0-169; 47) and 112 μg/L (±35.6; 5.1-175; 68) in filtered and unfiltered surface water samples, respectively, and 16.3 μg/g (±5.6; 5.1-35.2; 62) dry weight (dw) in brine shrimp. Mean (±SD; range; n) Cu concentrations were 4.2 (±2.1; 1.3-12.5; 47) and 6.9 μg/L (±6.6; 1.9-38.1; 68) in filtered and unfiltered surface water samples, respectively, and 20.6 μg/g (±18.4; 5.4-126; 62) dw in brine shrimp. Finally, mean (±SD; range; n) dissolved and total recoverable Se concentrations were 0.6 (±0.1; 0.4-1.2; 61) and 0.9 μg/L (±0.7; 0.5-3.6; 89), respectively, and 3.6 μg/g (±2.2; 1.1-14.9; 98) dw in brine shrimp. Thus, Se in open lake surface waters was most often in the range of 0.5-1 μg/L, and concentrations in both surface water and brine shrimp were comparable to concentrations measured in other monitoring programs for the GSL. Temporally, the statistical significance of differences in mean dissolved or total recoverable As, Cu, and Se concentrations between years was highly variable depending which test statistic was used, and there was no clear evidence of increasing or decreasing trends. In brine shrimp, significant differences in annual mean concentrations of As, Cu, and Se were observed using both parametric and nonparametric statistical approaches, but, as for water, there did not appear to be a consistent increase or decrease in concentrations of these elements over time. PMID:25690606

  15. West Hackberry Strategic Petroleum Reserve site brine-disposal monitoring, Year I report. Volume III. Biological oceanography. Final report

    Energy Technology Data Exchange (ETDEWEB)

    DeRouen, L.R.; Hann, R.W.; Casserly, D.M.; Giammona, C.; Lascara, V.J. (eds.)

    1983-02-01

    The Department of Energy's Strategic Petroleum Reserve Program began discharging brine into the Gulf of Mexico from its West Hackberry site near Cameron, Louisiana in May 1981. The brine originates from underground salt domes being leached with water from the Intracoastal Waterway, making available vast underground storage caverns for crude oil. The effects of brine discharge on aquatic organisms are presented in this volume. The topics covered are: benthos; nekton; phytoplankton; zooplankton; and data management.

  16. Bioencapsulation of the antibacterial drug sarafloxacin in nauplii of the brine shrimp Artemia franciscana

    OpenAIRE

    Dixon, B.A.; Van Poucke, S; Chair, M; Dehasque, M.; Nelis, H J; Sorgeloos, P.; De Leenheer, A P

    1995-01-01

    Nauplii of the brine shrimp Artemia franciscana were enriched with the antibacterial drug sarafloxacin hydrochloride to determine if levels effective against four pathogenetic strains of Vibrio spp. would accumulate in brine shrimp. Three vibrio strains were Vibrio anguillarum; the fourth was V. vulnificus. Concentrations of sarafloxacin ranging from 1 to 40% (weight: volume) were incorporated into the oil phase of Super Selco brine shrimp diets. Enriched nauplii and controls were sampled at ...

  17. Modeling brine and nutrient dynamics in Antarctic sea ice: The case of dissolved silica

    Science.gov (United States)

    Vancoppenolle, Martin; Goosse, Hugues; de Montety, Anne; Fichefet, Thierry; Tremblay, Bruno; Tison, Jean-Louis

    2010-02-01

    Sea ice ecosystems are characterized by microalgae living in brine inclusions. The growth rate of ice algae depends on light and nutrient supply. Here, the interactions between nutrients and brine dynamics under the influence of algae are investigated using a one-dimensional model. The model includes snow and ice thermodynamics with brine physics and an idealized sea ice biological component, characterized by one nutrient, namely, dissolved silica (DSi). In the model, DSi follows brine motion and is consumed by ice algae. Depending on physical ice characteristics, the brine flow is either advective, diffusive, or turbulent. The vertical profiles of ice salinity and DSi concentration are solutions of advection-diffusion equations. The model is configured to simulate the typical thermodynamic regimes of first-year Antarctic pack ice. The simulated vertical profiles of salinity and DSi qualitatively reproduce observations. Analysis of results highlights the role of convection in the lowermost 5-10 cm of ice. Convection mixes saline, nutrient-poor brine with comparatively fresh, nutrient-rich seawater. This implies a rejection of salt to the ocean and a flux of DSi to the ice. In the presence of growing algae, the simulated ocean-to-ice DSi flux increases by 0-115% compared to an abiotic situation. In turn, primary production and brine convection act in synergy to form a nutrient pump. The other important processes are the flooding of the surface by seawater and the percolation of meltwater. The former refills nutrients near the ice surface in spring. The latter, if present, tends to expell nutrients from the ice in summer.

  18. Sorption of cesium and strontium from concentrated brines by backfill barrier materials

    International Nuclear Information System (INIS)

    The sorption of radionuclides from potentially intruding groundwater at a nuclear waste repository is a major chemical function of backfill barriers. In this study, various materials (including clays, zeolites and an inorganic ion exchanger) were screened for the sorption of the fission products cesium and strontium in concentrated brines. Representative brines A and B for the Waste Isolation Pilot Plant (WIPP), a proposed radioactive waste repository and test facility in bedded salt were used. Sorption properties were quantified using empirical distribution coefficients, k/sub d/. Of the materials examined, sodium titanate had the highest k/sub d/ for the sorption of Sr(II) in both brine A (k/sub d/ = 125 ml/g) and brine B(k/sub d/ = 500 to 600 ml/g). A mordenite-type zeolite was the most effective getter for Cs(I) in brine A (k/sub d = 27 ml/g), while illite yielded the highest k/sub d/ for Cs(I) in brine B (k/sub d/ = 115 ml/g). The relative merit of these k/sub d/ values is evaluated in terms of calculated estimates of breakthrough times for a backfill barrier containing the getter. Results show that a backfill mixture containing these getters is potentially an effective barrier to the migration of Sr(II) and Cs(I), although further study (especially for the sorption of cesium from brine A) is recommended. Initial mechanistic studies revealed competing ion effects which would support an ion exchange mechanism. K/sub d/'s were constant over a Sr(II) concentration range of 10-11 to 10-5 M and a Cs(I) concentration range of 10-8 to 10-5 M, supporting the choice of a linear sorption isotherm as a model for the results. Constant batch composition was shown to be attained within one week

  19. Sorption of cesium and strontium from concentrated brines by backfill barrier materials

    Energy Technology Data Exchange (ETDEWEB)

    Winslow, C D

    1981-03-01

    The sorption of radionuclides from potentially intruding groundwater at a nuclear waste repository is a major chemical function of backfill barriers. In this study, various materials (including clays, zeolites and an inorganic ion exchanger) were screened for the sorption of the fission products cesium and strontium in concentrated brines. Representative brines A and B for the Waste Isolation Pilot Plant (WIPP), a proposed radioactive waste repository and test facility in bedded salt were used. Sorption properties were quantified using empirical distribution coefficients, k/sub d/. Of the materials examined, sodium titanate had the highest k/sub d/ for the sorption of Sr(II) in both brine A (k/sub d/ = 125 ml/g) and brine B(k/sub d/ = 500 to 600 ml/g). A mordenite-type zeolite was the most effective getter for Cs(I) in brine A (k/sub d = 27 ml/g), while illite yielded the highest k/sub d/ for Cs(I) in brine B (k/sub d/ = 115 ml/g). The relative merit of these k/sub d/ values is evaluated in terms of calculated estimates of breakthrough times for a backfill barrier containing the getter. Results show that a backfill mixture containing these getters is potentially an effective barrier to the migration of Sr(II) and Cs(I), although further study (especially for the sorption of cesium from brine A) is recommended. Initial mechanistic studies revealed competing ion effects which would support an ion exchange mechanism. K/sub d/'s were constant over a Sr(II) concentration range of 10/sup -11/ to 10/sup -5/ M and a Cs(I) concentration range of 10/sup -8/ to 10/sup -5/ M, supporting the choice of a linear sorption isotherm as a model for the results. Constant batch composition was shown to be attained within one week.

  20. Corrosion and hydrogen permeation of A216 grade WCA steel in hydrothermal magnesium-containing brines

    International Nuclear Information System (INIS)

    The US Department of Energy's Salt Repository Project (SRP) is investigating the general corrosion resistance of cast mild steel as a candidate material for waste package containers. Evaluation of this material is being performed at the Pacific Northwest Laboratory in environments simulating expected repository conditions. The present work addresses two potential failure modes of the reference waste package container: failure by general corrosion processes, and failure by internal hydrogen pressurization by permeation of corrosion product hydrogen. General corrosion studies of mild steel (ASTM A216 grade WCA) in the as-cast and normalized conditions were conducted in hydrothermal halite-saturated (saturated at ambient temperature) brine environments simulating a dissolution and an inclusion brine. Corrosion tests were also performed in brines similar to the inclusion brine but containing magnesium concentrations ranging from 1,000 to 30,000 ppm to investigate the effect of magnesium on the corrosion behavior. In addition, long-term (to 18 months) corrosion tests have been carried out using two-phase salt/brine environments (excess salt tests). Corrosion rates of the cast mild steel in brine were found to increase with increasing temperature and with increasing magnesium concentration. Some possible mechanisms that explain the observed behavior are presented. The corrosion rates observed in the excess-salt tests tend to decrease with time, at 200 degree and 150 degree C; and as-cast material corrodes more slowly than does normalized material. Corrosion-product hydrogen rapidly permeated a mild steel tubing corrosion/permeation specimen immersed in brine. The rate of permeation at 150 degree C was high enough to cause concern regarding potential container overpressurization

  1. Design Status of the Capillary Brine Residual in Containment Water Recovery System

    Science.gov (United States)

    Callahan, Michael R.; Sargusingh, Miriam

    2016-01-01

    One of the goals of the AES Life Support System (LSS) Project is to achieve 98% water loop closure for long duration human exploration missions beyond low Earth orbit. To meet this objective, the AES LSS Project is developing technologies to recover water from wastewater brine; highly concentrated waste products generated from a primary water recovery system. The state of the art system used aboard the International Space Station (ISS) has the potential to recover up to 85% water from unine wastewater, leaving a significant amounts of water in the waste brine, the recovery of which is a critical technology gap that must be filled in order to enable long duration human exploration. Recovering water from the urine wastewater brine is complicated by the concentration of solids as water is removed from the brine, and the concentration of the corrosive, toxic chemicals used to stabilize the urine which fouls and degrades water processing hardware, and poses a hazard to operators and crew. Brine Residual in Containment (BRIC) is focused on solids management through a process of "in-place" drying - the drying of brines within the container used for final disposal. Application of in-place drying has the potential to improve the safety and reliability of the system by reducing the exposure to crew and hardware to the problematic brine residual. Through a collaboration between the NASA Johnson Space Center and Portland Status University, a novel water recovery system was developed that utilizes containment geometry to support passive capillary flow and static phase separation allowing free surface evaporation to take place in a microgravity environment. A notional design for an ISS demonstration system was developed. This paper describes the concept for the system level design.

  2. Carbonation of brine impacted fractionated coal fly ash: implications for CO2 sequestration.

    Science.gov (United States)

    Nyambura, Muriithi Grace; Mugera, Gitari Wilson; Felicia, Petrik Leslie; Gathura, Ndungu Patrick

    2011-03-01

    Coal combustion by-products such as fly ash (FA), brine and CO(2) from coal fired power plants have the potential to impact negatively on the environment. FA and brine can contaminate the soil, surface and ground water through leaching of toxic elements present in their matrices while CO(2) has been identified as a green house gas that contributes significantly towards the global warming effect. Reaction of CO(2) with FA/brine slurry can potentially provide a viable route for CO(2) sequestration via formation of mineral carbonates. Fractionated FA has varying amounts of CaO which not only increases the brine pH but can also be converted into an environmentally benign calcite. Carbonation efficiency of fractionated and brine impacted FA was investigated in this study. Controlled carbonation reactions were carried out in a reactor set-up to evaluate the effect of fractionation on the carbonation efficiency of FA. Chemical and mineralogical characteristics of fresh and carbonated ash were evaluated using XRF, SEM, and XRD. Brine effluents were characterized using ICP-MS and IC. A factorial experimental approach was employed in testing the variables. The 20-150 μm size fraction was observed to have the highest CO(2) sequestration potential of 71.84 kg of CO(2) per ton of FA while the >150 μm particles had the lowest potential of 36.47 kg of CO(2) per ton of FA. Carbonation using brine resulted in higher degree of calcite formation compared to the ultra-pure water carbonated residues. PMID:20970918

  3. Aerobic methanotrophic communities at the Red Sea brine-seawater interface

    Directory of Open Access Journals (Sweden)

    Rehab Z. Abdallah

    2014-09-01

    Full Text Available The central rift of the Red Sea contains 25 brine pools with different physicochemical conditions, dictating the diversity and abundance of the microbial community. Three of these pools, the Atlantis II, Kebrit and Discovery Deeps, are uniquely characterized by a high concentration of hydrocarbons. The brine-seawater interface, described as an anoxic-oxic (brine-seawater boundary, is characterized by a high methane concentration, thus favoring aerobic methane oxidation. The current study analyzed the aerobic free–living methane-oxidizing bacterial communities that potentially contribute to methane oxidation at the brine-seawater interfaces of the three aforementioned brine pools, using metagenomic pyrosequencing, 16S rRNA pyrotags and pmoA library constructs. The sequencing of 16S rRNA pyrotags revealed that these interfaces are characterized by high microbial community diversity. Signatures of aerobic methane-oxidizing bacteria were detected in the Atlantis II Interface (ATII-I and the Kebrit Deep Upper (KB-U and Lower (KB-L brine-seawater interfaces. Through phylogenetic analysis of pmoA, we further demonstrated that the ATII-I aerobic methanotroph community is highly diverse. We propose four ATII-I pmoA clusters. Most importantly, cluster 2 groups with marine methane seep methanotrophs, and cluster 4 represent a unique lineage of an uncultured bacterium with divergent alkane monooxygenases. Moreover, non-metric multidimensional scaling (NMDS based on the ordination of putative enzymes involved in methane metabolism showed that the Kebrit interface layers were distinct from the ATII-I and DD-I brine-seawater interfaces.

  4. The Brine Shrimp Artemia: Adapted to Critical Life Conditions

    Science.gov (United States)

    Gajardo, Gonzalo M.; Beardmore, John A.

    2012-01-01

    The brine shrimp Artemia is a micro-crustacean, well adapted to the harsh conditions that severely hypersaline environments impose on survival and reproduction. Adaptation to these conditions has taken place at different functional levels or domains, from the individual (molecular-cellular-physiological) to the population level. Such conditions are experienced by very few equivalent macro-planktonic organisms; thus, Artemia can be considered a model animal extremophile offering a unique suite of adaptations that are the focus of this review. The most obvious is a highly efficient osmoregulation system to withstand up to 10 times the salt concentration of ordinary seawater. Under extremely critical environmental conditions, for example when seasonal lakes dry-out, Artemia takes refuge by producing a highly resistant encysted gastrula embryo (cyst) capable of severe dehydration enabling an escape from population extinction. Cysts can be viewed as gene banks that store a genetic memory of historical population conditions. Their occurrence is due to the evolved ability of females to “perceive” forthcoming unstable environmental conditions expressed by their ability to switch reproductive mode, producing either cysts (oviparity) when environmental conditions become deleterious or free-swimming nauplii (ovoviviparity) that are able to maintain the population under suitable conditions. At the population level the trend is for conspecific populations to be fragmented into locally adapted populations, whereas species are restricted to salty lakes in particular regions (regional endemism). The Artemia model depicts adaptation as a complex response to critical life conditions, integrating and refining past and present experiences at all levels of organization. Although we consider an invertebrate restricted to a unique environment, the processes to be discussed are of general biological interest. Finally, we highlight the benefits of understanding the stress response of

  5. The brine shrimp Artemia: adapted to critical life conditions

    Directory of Open Access Journals (Sweden)

    Gonzalo M Gajardo

    2012-06-01

    Full Text Available The brine shrimp Artemia is a micro-crustacean, well adapted to the harsh conditions that severely hypersaline environments impose on survival and reproduction. Adaptation to these conditions has taken place at different functional levels or domains, from the individual (molecular-cellular-physiological to the population level. Such conditions are experienced by very few equivalent macro-planktonic organisms; thus, Artemia can be considered a model animal extremophile offering a unique suite of adaptations that are the focus of this review. The most obvious is a highly efficient osmoregulation system to withstand up to 10 times the salt concentration of ordinary seawater. Under extremely critical environmental conditions, for example when seasonal lakes dry out, Artemia takes refuge by producing a highly resistant encysted gastrula embryo (cyst capable of severe dehydration enabling an escape from population extinction. Cysts can be viewed as gene banks that store a genetic memory of historical population conditions. Their occurrence is due to the evolved ability of females to perceive forthcoming unstable environmental conditions expressed by their ability to switch reproductive mode, producing either cysts (oviparity when environmental conditions become deleterious or free-swimming nauplii (ovoviviparity that are able to maintain the population under suitable conditions.At the population level the trend is for conspecific populations to be fragmented into locally adapted populations, whereas species are restricted to salty lakes in particular regions (regional endemism. The Artemia model depicts adaptation as a complex response to critical life conditions, integrating and refining past and present experiences at all levels of organization. Although we consider an invertebrate restricted to a unique environment, the processes to be discussed are of general biological interest. Finally, we highlight the benefits of understanding the stress

  6. Complement components of nerve regeneration conditioned fluid influence the microenvironment of nerve regeneration

    Directory of Open Access Journals (Sweden)

    Guang-shuai Li

    2016-01-01

    Full Text Available Nerve regeneration conditioned fluid is secreted by nerve stumps inside a nerve regeneration chamber. A better understanding of the proteinogram of nerve regeneration conditioned fluid can provide evidence for studying the role of the microenvironment in peripheral nerve regeneration. In this study, we used cylindrical silicone tubes as the nerve regeneration chamber model for the repair of injured rat sciatic nerve. Isobaric tags for relative and absolute quantitation proteomics technology and western blot analysis confirmed that there were more than 10 complement components (complement factor I, C1q-A, C1q-B, C2, C3, C4, C5, C7, C8ß and complement factor D in the nerve regeneration conditioned fluid and each varied at different time points. These findings suggest that all these complement components have a functional role in nerve regeneration.

  7. The Concept about the Regeneration of Spent Borohydrides and Used Catalysts from Green Electricity

    Directory of Open Access Journals (Sweden)

    Cheng-Hong Liu

    2015-06-01

    Full Text Available Currently, the Brown-Schlesinger process is still regarded as the most common and mature method for the commercial production of sodium borohydride (NaBH4. However, the metallic sodium, currently produced from the electrolysis of molten NaCl that is mass-produced by evaporation of seawater or brine, is probably the most costly raw material. Recently, several reports have demonstrated the feasibility of utilizing green electricity such as offshore wind power to produce metallic sodium through electrolysis of seawater. Based on this concept, we have made improvements and modified our previously proposed life cycle of sodium borohydride (NaBH4 and ammonia borane (NH3BH3, in order to further reduce costs in the conventional Brown-Schlesinger process. In summary, the revision in the concept combining the regeneration of the spent borohydrides and the used catalysts with the green electricity is reflected in (1 that metallic sodium could be produced from NaCl of high purity obtained from the conversion of the byproduct in the synthesis of NH3BH3 to devoid the complicated purification procedures if produced from seawater; and (2 that the recycling and the regeneration processes of the spent NaBH4 and NH3BH3 as well as the used catalysts could be simultaneously carried out and combined with the proposed life cycle of borohydrides.

  8. Current Bioengineering Methods for Whole Kidney Regeneration

    Directory of Open Access Journals (Sweden)

    Shuichiro Yamanaka

    2015-01-01

    Full Text Available Kidney regeneration is likely to provide an inexhaustible source of tissues and organs for immunosuppression-free transplantation. It is currently garnering considerable attention and might replace kidney dialysis as the ultimate therapeutic strategy for renal failure. However, anatomical complications make kidney regeneration difficult. Here, we review recent advances in the field of kidney regeneration, including (i the directed differentiation of induced pluripotent stem cells/embryonic stem cells into kidney cells; (ii blastocyst decomplementation; (iii use of a decellularized cadaveric scaffold; (iv embryonic organ transplantation; and (v use of a nephrogenic niche for growing xenoembryos for de novo kidney regeneration from stem cells. All these approaches represent potentially promising therapeutic strategies for the treatment of patients with chronic kidney disease. Although many obstacles to kidney regeneration remain, we hope that innovative strategies and reliable research will ultimately allow the restoration of renal function in patients with end-stage kidney disease.

  9. NOx adsorber and method of regenerating same

    Science.gov (United States)

    Endicott, Dennis L.; Verkiel, Maarten; Driscoll, James J.

    2007-01-30

    New technologies, such as NOx adsorber catalytic converters, are being used to meet increasingly stringent regulations on undesirable emissions, including NOx emissions. NOx adsorbers must be periodically regenerated, which requires an increased fuel consumption. The present disclosure includes a method of regenerating a NOx adsorber within a NOx adsorber catalytic converter. At least one sensor positioned downstream from the NOx adsorber senses, in the downstream exhaust, at least one of NOx, nitrous oxide and ammonia concentrations a plurality of times during a regeneration phase. The sensor is in communication with an electronic control module that includes a regeneration monitoring algorithm operable to end the regeneration phase when a time rate of change of the at least one of NOx, nitrous oxide and ammonia concentrations is after an expected plateau region begins.

  10. Changes of washing water during debittering and the brine during storage of irradiated olive fruits (Olea europea. L.)

    International Nuclear Information System (INIS)

    Olive fruits (Olea europea. var. Surrany) treated with 0, 1, 2 and 3 kGy of gamma irradiation were debittered in distilled water for 8 days and stored in brine for 12 months at room temperature. Total dissolved and inorganic dissolved solids, Na, K, Ca, electric conductivity (EC) and pH values were evaluated in washing wastewater (daily), and in brine (after 6 and 12 months). The results showed that gamma irradiation increased the total and inorganic dissolved solids, Na and K in washing wastewater, and in brine throughout debittering and storage periods. Also, gamma irradiation had an effect on EC and pH values of washing wastewater and brine

  11. Effects of a Pre-Filter and Electrolysis Systems on the Reuse of Brine in the Chinese Cabbage Salting Process

    OpenAIRE

    Kim, Dong-Ho; Yoo, Jae Yeol; Jang, Keum-Il

    2016-01-01

    In this study, the effects of a pre-filter system and electrolysis system on the safe and efficient reuse of brine in the cabbage salting process were investigated. First, sediment filter-electrolyzed brine (SF-EB) was selected as brine for reuse. Then, we evaluated the quality and microbiological properties of SF-EB and Chinese cabbage salted with SF-EB. The salinity (9.4%) and pH (4.63) of SF-EB were similar to those of control brine (CB). SF-EB turbidity was decreased (from 0.112 to 0.062)...

  12. Behavior of natural uranium, thorium, and radium isotopes in the Wolfcamp brine aquifers, Palo Duro Basin, Texas

    International Nuclear Information System (INIS)

    Previously reported results for Palo Duro deep brines show that Ra is highly soluble and not retarded. Relative to Ra, U and Th are highly sorbed. Uranium, like thorium, is in the +4 valence state, indicating a reducing environment. Additional data reported here support these results. However, one Wolfcamp brine sample gives somewhat different results. Radium appears to be somewhat sorbed. Uranium is largely in the +6 valence state, indicating a less reducing condition. In all brines, kinetics for sorption (228Th) and desorption (224Ra) are rapid. This Wolfcamp brine was tested for the effects of colloids for Ra, U, and Th concentrations. No effects were found

  13. Experimental Work Conducted on MgO Inundated Hydration in WIPP-Relevant Brines

    Science.gov (United States)

    Deng, H.; Xiong, Y.; Nemer, M. B.; Johnsen, S.

    2009-12-01

    Magnesium oxide (MgO) is being emplaced in the Waste Isolation Pilot Plant (WIPP) as an engineered barrier to mitigate the effect of microbial CO2 generation on actinide mobility in a postclosure repository environment. MgO will sequester CO2 and consume water in brine or water vapor in the gaseous phase. Martin Marietta (MM) MgO is currently being emplaced in the WIPP. A fractional-factorial experiment has been performed to study the inundated-hydration of MM MgO as a function of its particle size, solid-to-liquid ratio, and brine type. MgO hydration experiments have been carried out with three MgO particle sizes and two solid-to-liquid ratios in three WIPP-related brines: ERDA-6, GWB and simplified GWB. ERDA-6 is a synthetic NaCl-rich brine typical of a Castile brine reservoir below the repository. GWB is a synthetic MgCl2- and NaCl-rich brine representative of intergranular brines from the Salado Formation at or near the stratigraphic horizon of the repository. Simplified GWB contains amounts of Mg, Na, and Cl similar to those in GWB without other minor constituents. The hydration products include brucite (Mg(OH)2) and phase 5 (Mg3(OH)5Cl4H2O). In addition to phase 5, MgO hydration in GWB or simplified GWB produces brucite, whereas MgO hydrated in ERDA-6 only produces brucite. The MgO particle size has had a significant effect on the formation of hydration products: small MgO particles have hydrated before the large particles. MgO has hydrated faster in simplified GWB than in the other two brines. In ERDA-6, the solid-to-liquid ratio has affected the brine pH due to the presence of CaO (~1 wt %) as an impurity in MM MgO. GWB has sufficient dissolved Mg to buffer pH despite small amounts of CaO. Both our results and thermodynamic modeling indicate that phase-5 is the stable Mg-OH-Cl phase in Mg-Na-Cl-dominated brines with ionic strengths and chemical compositions similar to that of GWB. In contrast, phase-3 (Mg2(OH)3Cl4H2O) is the stable phase in the MgCl2

  14. The origin of brines and salts in Chilean salars: a hydrochemical review

    Science.gov (United States)

    Risacher, François; Alonso, Hugo; Salazar, Carlos

    2003-11-01

    Northern Chile is characterized by a succession of north-south-trending ranges and basins occupied by numerous saline lakes and salt crusts, collectively called salars. Fossil salt crusts are found to the west in the extremely arid Central Valley, while active salars receiving permanent inflows fill many intravolcanic basins to the east in the semiarid Cordillera. Sea salts and desert dust are blown eastward over the Cordillera, where they constitute an appreciable fraction of the solute load of very dilute waters (salt contentsalars. Saline lakes and subsurface brines are under steady-state regime. The average residence time of conservative components ranges from a few years to some thousands years, which indicates a permanent leakage of the brines through bottom sediments. The infiltrating brines are recycled in the hydrologic system where they mix with dilute meteoric waters. High heat flow is the likely driving force that moves the deep waters in this magmatic arc region. Active Chilean salars cannot be considered as terminal lakes nor, strictly speaking, as closed basin lakes. Almost all incoming salts leave the basin and are transported elsewhere. Moreover, the dissolution of fossil salt crusts in some active salars also carries away important fluxes of components in percolating brines. Evaporative concentration of inflow waters leads to sulfate-rich or calcium-rich, near-neutral brines. Alkaline brines are almost completely lacking. The alkalinity/calcium ratio of inflow waters is lowered by the oxidation of native sulfur (reducing alkalinity) and the deposition of eolian gypsum (increasing Ca concentration). Theoretically, SO 4-rich inflow waters and their derived SO 4-rich brines should be found in the intravolcanic basins of the Cordillera because of the ubiquity of native sulfur, while Ca-rich brines should prevail in sedimentary basins where Ca-rich minerals are abundant. This relation is perfectly observed in the salar de Atacama, the largest in Chile

  15. Distinctive Microbial Community Structure in Highly Stratified Deep-Sea Brine Water Columns

    KAUST Repository

    Bougouffa, Salim

    2013-03-29

    Atlantis II and Discovery are two hydrothermal and hypersaline deep-sea pools in the Red Sea rift that are characterized by strong thermohalo-stratification and temperatures steadily peaking near the bottom. We conducted comprehensive vertical profiling of the microbial populations in both pools and highlighted the influential environmental factors. Pyrosequencing of the 16S rRNA genes revealed shifts in community structures vis-à-vis depth. High diversity and low abundance were features of the deepest convective layers despite the low cell density. Surprisingly, the brine interfaces had significantly higher cell counts than the overlying deep-sea water, yet they were lowest in diversity. Vertical stratification of the bacterial populations was apparent as we moved from the Alphaproteobacteria-dominated deep sea to the Planctomycetaceae- or Deferribacteres-dominated interfaces to the Gammaproteobacteria-dominated brine layers. Archaeal marine group I was dominant in the deep-sea water and interfaces, while several euryarchaeotic groups increased in the brine. Across sites, microbial phylotypes and abundances varied substantially in the brine interface of Discovery compared with Atlantis II, despite the near-identical populations in the overlying deep-sea waters. The lowest convective layers harbored interestingly similar microbial communities, even though temperature and heavy metal concentrations were very different. Multivariate analysis indicated that temperature and salinity were the major influences shaping the communities. The harsh conditions and the low-abundance phylotypes could explain the observed correlation in the brine pools.

  16. Effects of gamma radiation on the survival and growth of brine shrimp, Artemia salina

    International Nuclear Information System (INIS)

    To determine the effects of gamma radiation on the survival and growth of brine shrimp, nauplii and adults were exposed to different doses of radiation and maintained at different salinities and temperatures. The LD50 determination demonstrated that nauplii were thirty to forty times more sensitive than the adults and had a 25-day LD50 of 450 rads. Radiation and salinity reduced survival of adult female brine shrimp more than the males. The interaction of salinity, 5 and 50 ppt, temperature, 10, 20 and 300C, and radiation, 25 to 100 kilorads, decreased the survival of both male and female brine shrimp, with the males having the greater sensitivity. Brine shrimp nauplii irradiated with doses of 500 and 2,500 rads had accelerated growth and matured earlier than the controls. A test of the effect of crowding on growth showed that volume per individual was important, and a dose of 500 rads accelerated brine shrimp growth in all concentrations, with the greatest increase at 8 ml/nauplius

  17. Geochemical evaluation of flowback brine from Marcellus gas wells in Pennsylvania, USA

    International Nuclear Information System (INIS)

    Large quantities of highly saline brine flow from gas wells in the Marcellus Formation after hydraulic stimulation (“fracking”). This study assesses the composition of these flowback waters from the Marcellus shale in Pennsylvania, USA. Concentrations of most inorganic components of flowback water (Cl, Br, Na, K, Ca, Mg, Sr, Ba, Ra, Fe, Mn, total dissolved solids, and others) increase with time from a well after hydraulic stimulation. Based on results in several datasets reported here, the greatest concentration of Cl− in flowback water is 151,000 mg/L. For total Ra (combined 226Ra and 228Ra) in flowback, the highest level reported is 6540 pCi/L. Flowback waters from hydraulic fracturing of Marcellus wells resemble brines produced from conventional gas wells that tap into other Paleozoic formations in the region. The Br/Cl ratio and other parameters indicate that both types of brine formed by the evaporation of seawater followed by dolomitization, sulfate reduction and subsurface mixing with seawater and/or freshwater. Trends and relationships in brine composition indicate that (1) increased salt concentration in flowback is not mainly caused by dissolution of salt or other minerals in rock units, (2) the flowback waters represent a mixture of injection waters with highly concentrated in situ brines similar to those in the other formations, and (3) these waters contain concentrations of Ra and Ba that are commonly hundreds of times the US drinking water standards.

  18. Inhibitors of lactic acid fermentation in Spanish-style green olive brines of the Manzanilla variety.

    Science.gov (United States)

    Medina, Eduardo; Romero, Concepción; de Castro, Antonio; Brenes, Manuel; García, Aranzazu

    2008-10-15

    Frequently, a delay or lack of lactic acid fermentation occurs during the processing of Spanish-style green olives, in particular of the Manzanilla variety. Many variables can affect the progress of fermentation such as temperature, nutrients, salt concentration, antimicrobials in brines, and others. In this study, it was demonstrated that an inappropriate alkaline treatment (low NaOH strength and insufficient alkali penetration) allowed for the presence of several antimicrobial compounds in brines, which inhibited the growth of Lactobacillus pentosus. These substances were the dialdehydic form of decarboxymethyl elenolic acid either free or linked to hydroxytyrosol and an isomer of oleoside 11-methyl ester. Olive brines, from olives treated with a NaOH solution of low concentration up to 1/2 the distance to the pit, contained these antimicrobials, and no lactic acid fermentation took place in them. By contrast, a more intense alkaline treatment (2/3 lye depth penetration) gave rise to an abundant growth of lactic acid bacteria without any antimicrobial in brines. Therefore, the precise cause of stuck fermentation in Manzanilla olive brines was demonstrated for the first time and this finding will contribute to better understand the table olive fermentation process. PMID:26047282

  19. Highly selective lithium recovery from brine using a λ-MnO2-Ag battery.

    Science.gov (United States)

    Lee, Jaehan; Yu, Seung-Ho; Kim, Choonsoo; Sung, Yung-Eun; Yoon, Jeyong

    2013-05-28

    The demand for lithium has greatly increased with the rapid development of rechargeable batteries. Currently, the main lithium resource is brine lakes, but the conventional lithium recovery process is time consuming, inefficient, and environmentally harmful. Rechargeable batteries have been recently used for lithium recovery, and consist of lithium iron phosphate as a cathode. These batteries feature promising selectivity between lithium and sodium, but they suffer from severe interference from coexisting magnesium ions, an essential component of brine, which has prompted further study. This study reports on a highly selective and energy-efficient lithium recovery system using a rechargeable battery that consists of a λ-MnO2 positive electrode and a chloride-capturing negative electrode. This system can be used to recover lithium from brine even in the presence of magnesium ions as well as other dissolved cations. In addition, lithium recovery from simulated brine is successfully demonstrated, consuming 1.0 W h per 1 mole of lithium recovered, using water similar to that from the artificial brine, which contains various cations (mole ratio: Na/Li ≈ 15.7, K/Li ≈ 2.2, Mg/Li ≈ 1.9). PMID:23595419

  20. Evaporative Evolution of Carbonate-Rich Brines from Synthetic Topopah Spring Tuff Pore Water, Yucca Mountain

    Energy Technology Data Exchange (ETDEWEB)

    Sutton, M; Alai, M; Carroll, S A

    2004-04-14

    The evaporation of a range of synthetic pore water solutions representative of the potential high-level-nuclear-waste repository at Yucca Mountain, NV is being investigated. The motivation of this work is to understand and predict the range of brine compositions that may contact the waste containers from evaporation of pore waters, because these brines could form corrosive thin films on the containers and impact their long-term integrity. A relatively complex synthetic Topopah Spring Tuff pore water was progressively concentrated by evaporation in a closed vessel, heated to 95 C in a series of sequential experiments. Periodic samples of the evaporating solution were taken to determine the evolving water chemistry. According to chemical divide theory at 25 C and 95 C our starting solution should evolve towards a high pH carbonate brine. Results at 95 C show that this solution evolves towards a complex brine that contains about 99 mol% Na{sup +} for the cations, and 71 mol% Cl{sup -}, 18 mol% {Sigma}CO{sub 2}(aq), 9 mol%SO{sub 4}{sup 2-} for the anions. Initial modeling of the evaporating solution indicates precipitation of aragonite, halite, silica, sulfate and fluoride phases. The experiments have been used to benchmark the use of the EQ3/6 geochemical code in predicting the evolution of carbonate-rich brines during evaporation.