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Sample records for aqueous ammonium chloride

  1. Surface tension measurements of aqueous ammonium chloride (NH4Cl) in air

    Science.gov (United States)

    Lowry, S. A.; Mccay, M. H.; Mccay, T. D.; Gray, P. A.

    1989-01-01

    Aqueous NH4Cl's solidification is often used to model metal alloy solidification processes. The present determinations of the magnitude of the variation of aqueous NH4Cl's surface tension as a function of both temperature and solutal concentration were conducted at 3, 24, and 40 C over the 72-100 wt pct water solutal range. In general, the surface tension increases 0.31 dyn/cm per percent decrease in wt pct of water, and decreases 0.13 dyn/cm for each increase in deg C. Attention is given to the experimental apparatus employed.

  2. 21 CFR 172.165 - Quaternary ammonium chloride combination.

    Science.gov (United States)

    2010-04-01

    ... HUMAN CONSUMPTION Food Preservatives § 172.165 Quaternary ammonium chloride combination. The food... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Quaternary ammonium chloride combination. 172.165 Section 172.165 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN...

  3. N-Chlorotaurine and ammonium chloride: an antiseptic preparation with strong bactericidal activity.

    Science.gov (United States)

    Gottardi, Waldemar; Arnitz, Roland; Nagl, Markus

    2007-04-20

    The bactericidal activity of the endogenous antiseptic N-chlorotaurine (NCT) is significantly enhanced in the presence of ammonium chloride which induces the formation of monochloramine (NH(2)Cl) whose strong bactericidal activity is well known. In this study the properties of NCT plus ammonium chloride have been investigated. The reaction of active chlorine compounds like chloramine-T (N-chlorotoluene-sulfonamide sodium), chloroisocyanuric acid derivatives, hypochlorites (NaOCl, CaOCl(2)) with ammonium chloride did not stop at the stage of monochloramine, and the pungent smelling by-products di- and trichloramine, NHCl(2) and NCl(3), were also formed. This was not the case with NCT where only monochloramine was generated. The equilibrium constant of the reaction of NCT with ammonium was found to be [Formula: see text] , which allows to estimate the equilibrium concentration of monochloramine in aqueous solutions of NCT and ammonium chloride. At concentrations each ranging between 0.01% and 1.0% it comes to [NH(2)Cl]=3.5-254 ppm. As an unexpected result the monochloramine containing formulation turned out to be most stable in plain water without buffer additives. Quantitative killing assays revealed complete inactivation of 10(6) to 10(7)CFU/mL of seven bacterial strains by 0.1% NCT plus 0.1% ammonium chloride within 5 min, while with plain 0.1% NCT an incubation time of 2-4h was needed to achieve the same effect. The highly significant increase of bactericidal activity (200-300-fold) could be assigned to the presence of monochloramine which could be isolated by vacuum distillation. Aqueous solutions of NCT and ammonium chloride provide a highly effective and well tolerable antiseptic preparation appropriate to a treatment cycle of at least 1 month if stored in the refrigerator.

  4. Alkali metal and ammonium chlorides in water and heavy water (binary systems)

    CERN Document Server

    Cohen-Adad, R

    1991-01-01

    This volume surveys the data available in the literature for solid-fluid solubility equilibria plus selected solid-liquid-vapour equilibria, for binary systems containing alkali and ammonium chlorides in water or heavy water. Solubilities covered are lithium chloride, sodium chloride, potassium chloride, rubidium chloride, caesium chloride and ammonium chloride in water and heavy water.

  5. Recovering germanium from coal ash by chlorination with ammonium chloride

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A new process of enriching germanium from coal ash was developed. The process involves in mixing the coal ash and ammonium chloride and then roasting the mixture to produce germanium chloride that is then absorbed by dilute hydrochloric acid and hydrolyzed to germanium oxide. The germanium recovery reached to 80.2% at the optimum condition: mass ratio of NH4Cl/coal ash is 0.15, roasting temperature 400℃ and roasting time 90 min.

  6. Hibiscus sabdariffa Affects Ammonium Chloride-Induced Hyperammonemic Rats

    OpenAIRE

    Subramanian, P.; M. Mohamed Essa

    2007-01-01

    Hibiscus sabdariffa (HS) is an edible medicinal plant, indigenous to India, China and Thailand and is used in Ayurveda and traditional medicine. Alcoholic extract of HS leaves (HSEt) was studied for its anti-hyperammonemic and antioxidant effects in brain tissues of ammonium chloride-induced hyperammonemic rats. Oral administration of HSEt (250 mg kg−1 body weight) significantly normalizes the levels of ammonia, urea, uric acid, creatinine and non-protein nitrogen in the blood. HSEt significa...

  7. The use of bis (-2-ethylhexyl) phosphoric acid for the extraction of zinc from concentrated ammonium chloride solutions

    Energy Technology Data Exchange (ETDEWEB)

    Amer, S.; Luis, A.; Cuadra, A. de la; Caravaca, C.

    1994-01-01

    The extraction of zinc from concentrated ammonium chloride solutions by means of the bis(-2-ethylhexyl) phosphoric acid is studied. Mass balances and chemical equilibria relating the different chemical species in both phases are presented in order to establish a model describing the behaviour of the different species. Good agreement between experimental data and theoretical curves is obtained. A comparison of the zinc extraction from a strong complexing medium as that of concentrated ammonium chloride solutions with an uncomplexing zinc perchlorate solution is made, in order to see the influence of the complexing effect of the aqueous phase on zinc extraction. (Author) 36 p.

  8. Hibiscus sabdariffa Affects Ammonium Chloride-Induced Hyperammonemic Rats

    Directory of Open Access Journals (Sweden)

    M. Mohamed Essa

    2007-01-01

    Full Text Available Hibiscus sabdariffa (HS is an edible medicinal plant, indigenous to India, China and Thailand and is used in Ayurveda and traditional medicine. Alcoholic extract of HS leaves (HSEt was studied for its anti-hyperammonemic and antioxidant effects in brain tissues of ammonium chloride-induced hyperammonemic rats. Oral administration of HSEt (250 mg kg−1 body weight significantly normalizes the levels of ammonia, urea, uric acid, creatinine and non-protein nitrogen in the blood. HSEt significantly reduced brain levels of lipid peroxidation products such as thiobarbituric acid and reactive substances (TBARS and hydroperoxides (HP. However, the administered extract significantly increased the levels of antioxidants such as catalase (CAT, superoxide dismutase (SOD, glutathione peroxidase (GPx and reduced glutathione (GSH in brain tissues of hyperammonemic rats. This investigation demonstrates significant anti-hyperammonemic and antioxidant activity of HS.

  9. Aqueous Media Oxidation of Alcohols with Ammonium Persulfate

    Institute of Scientific and Technical Information of China (English)

    IMANZADEH, Gholam Hassan; ZAMANLOO, Mohammad R.; MANSOORI, Yaghoob; KHODAYARI, Ali

    2007-01-01

    Oxidation of series of various primary and secondary alcohols to corresponding carbonyl compounds with ammonium persulfate in aqueous media was described. No over oxidation of primary alcohols to carboxylic acids and secondary alcohols to esters was observed. Under such conditions benzoin was converted to benzoic acid.

  10. Preparation and characteristic research of anhydrous magnesium chloride with dehydrated ammonium carnallite

    Institute of Scientific and Technical Information of China (English)

    ZHOU Ning-bo; CHEN Bai-zhen; HE Xin-kuai; LI Yi-bing

    2006-01-01

    Taking the saline lake bischofite and NH4Cl that was removed with the ammonia method and continuwas synthesized. And then the ammonium carnallite was dehydrated to some extent at 160℃ for 4 h. Ammonium carnallite reacted with ammonia at 240℃ for 150 min and the ammonation ammonium carnallite was produced. Finally, the ammonation ammonium carnallite was calcined at 750℃ into anhydrous magnesium chloride containing only 0.1% (mass fraction) of MgO. On the other hand, dehydrated ammonium carnallite was mixed with the solid ammonium chloride at mass ratio 1:4 at high temperature and with the differential pressure of HN3 above 30.5 kPa. The dehydrated ammonium carnallite of mixture was dehydrated at 410℃, and then calcined at 700℃ into anhydrous magnesium chloride with only 0. 087% (mass fraction) of MgO. X-ray diffraction and electron microscopy analysis results prove that anhydrous magnesium chloride obtained by both methods hasn't mixed phases, the particle is large and even has good dispersion, which is suitable for preparation of metal magnesium in the electrolysis.

  11. Preparation of anhydrous magnesium chloride in a gas-solid reaction with ammonium carnallite

    Institute of Scientific and Technical Information of China (English)

    Zhou Ningbo; Chen Baizhen; He Xinkuai; Li Yibing

    2006-01-01

    Dehydrated ammonium carnallite was synthesized with bischofite from salt lake and ammonium chloride solution in a 1:1 molar ratio of MgCl2:NH4Cl,dehydrated at 160℃ for about 4 h.The yield was above 85%.The product was then mixed with solid-state ammonium chloride with a 1:4 mass ratio for the further dehydration at 410℃.The decomposition of NH4Cl made a pressure of NH3 at 30.5 kPa to prevent the hydrolysis of ammonium carnallite.The anhydration of magnesium chloride was achieved at 700℃.The results showed that anhydrous magnesium chloride contains magnesium oxide in an amount that was less than 0.1% by weight.XRD pattern and SEM micrograph showed a good dispersion of ammonium carnallite and anhydrous magnesium chloride crystals with well-distributed big grains,just enough to meet the need for the production of magnesium metal in the electrolysis process.

  12. Antioxidant Potential of Momordica Charantia in Ammonium Chloride-Induced Hyperammonemic Rats

    OpenAIRE

    A. Justin Thenmozhi; Subramanian, P.

    2011-01-01

    The present study was aimed to investigate the antioxidant potential of Momordica charantia fruit extract (MCE) in ammonium chloride-induced (AC) hyperammonemic rats. Experimental hyperammonemia was induced in adult male Wistar rats (180–200 g) by intraperitoneal injections of ammonium chloride (100 mg kg−1 body weight) thrice a week. The effect of oral administration (thrice a week for 8 consecutive weeks) of MCE (300 mg kg−1 body weight) on blood ammonia, plasma urea, serum liver marker enz...

  13. (tert-Butyl)(2-hydroxyethyl)ammonium chloride

    OpenAIRE

    Cintya Valerio-Cárdenas; Simón Hernández-Ortega; David Morales-Morales

    2014-01-01

    In the cation of the title molecular salt, C6H16NO+·Cl−, the N—C—C—O torsion angle is 176.5 (2)°. In the crystal, the cations and chloride ions are linked by N—H...O and O—H...O hydrogen bonds, generating a two-dimensional network parallel to (100).

  14. Aqueous Chloride Operations Overview: Plutonium and Americium Purification/Recovery

    Energy Technology Data Exchange (ETDEWEB)

    Gardner, Kyle Shelton [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kimball, David Bryan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Skidmore, Bradley Evan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-09-28

    These are a set of slides intended for an information session as part of recruiting activities at Brigham Young University. It gives an overview of aqueous chloride operations, specifically on plutonium and americium purification/recovery. This presentation details the steps taken perform these processes, from plutonium size reduction, dissolution, solvent extraction, oxalate precipitation, to calcination. For Americium recovery, it details the CLEAR (chloride extraction and actinide recovery) Line, oxalate precipitation and calcination.

  15. High levan production by Bacillus licheniformis NS032 using ammonium chloride as the sole nitrogen source.

    Science.gov (United States)

    Kekez, B D; Gojgic-Cvijovic, G D; Jakovljevic, D M; Stefanovic Kojic, J R; Markovic, M D; Beskoski, V P; Vrvic, M M

    2015-03-01

    In this study, levan production by Bacillus licheniformis NS032 isolated from a petroleum sludge sample was investigated. High levan yield was obtained in a wide range of sucrose concentrations (up to 400 g/L) and, contrary to most levan-producing strains, using ammonium chloride as the sole N source. Interaction between sucrose, ammonium chloride, and initial pH of the medium in a low sucrose (60-200 g/L) and a high sucrose (300-400 g/L) system was analyzed by response surface methodology. According to the calculated model in the low sucrose system, maximum predicted levan yield was 47.8 g/L (sucrose 196.8 g/L, ammonium chloride 2.4 g/L, pH 7.0), while in the high sucrose system, levan yield was 99.2 g/L (sucrose 397.6 g/L, ammonium chloride 4.6 g/L, pH 7.4). In addition, protective effect of microbial levan against copper toxicity to Daphnia magna is observed for the first time. The acute toxicity (48 h EC50) of copper decreased from 0.14 to 0.44 mg/L by levan in concentration of 50 ppm. PMID:25592434

  16. The Influence of the Anionic Counter-Ion on the Activity of Ammonium Substituted Hoveyda-Type Olefin Metathesis Catalysts in Aqueous Media

    Science.gov (United States)

    Gułajski, Łukasz; Grela, Karol

    Polar olefin metathesis catalysts, bearing an ammonium group are presented. The electron withdrawing ammonium group not only activates the catalysts electronically, but at the same time makes the catalysts more hydrophilic. Catalysts can be therefore efficiently used not only in traditional media, such as methylene chloride and toluene, but also in technical-grade alcohols, alcohol— water mixtures and in neat water. Finally, in this overview the influence of the anionic counter-ion on the activity of ammonium substituted Hoveyda-type olefin metathesis catalysts in aqueous media is presented.

  17. Effect of Ammonium Chloride Solution on the Growth of Phosphorus Gypsum Whisker and Its Modification

    OpenAIRE

    Shouwei Jian; Mengqi Sun; Guihai He; Zhenzhen Zhi; Baoguo Ma

    2016-01-01

    Phosphogypsum is the by-product of phosphate of fertilizer or phosphate which causes serious environmental pollution. In this work, a series of phosphogypsum whiskers were prepared using phosphogypsum as raw materials and NH4Cl as additive through the atmospheric water solution method. The results showed that the ammonium chloride solution has a great influence on phosphogypsum whiskers growth and the solubility. The best whisker aspect ratio of phosphogypsum was preferred in 1 mol/L NH4Cl so...

  18. INTERACTION OF POLYVINYLPYRROLIDONE WITH METAL CHLORIDE AQUEOUS SOLUTIONS

    Institute of Scientific and Technical Information of China (English)

    Mohammad Saleem Khan; Khaista Gul; Najeeb Ur Rehman

    2004-01-01

    Interactions of polyvinylpyrrolidone (PVP) with metal chlorides (MgCl2, CaCl2, KC1 and BaC12) have been investigated by viscometric and spectrophotometric techniques in aqueous solutions. Intrinsic viscosity [η] of (PVP) has shown a discontinuity with varying concentration of metal chlorides. The decreasing order of effectiveness of cation is K1+>Ca2+> Mg2+> Ba2+ for poly(vinylpyrrolidone) solution. Changes in the absorption spectra of the cosolutes were observed in the presence of PVP in the lower limit of the UV-visible region i.e. 200-210 nm. These changes were attributed to interaction of PVP molecules with the cosolute molecules. As the concentration of the cosolute increased, a red shift in the peaks was observed, indicating an increase in interaction between PVP and cosolutes.

  19. Flotation of kaolinite and diaspore with hexadecyl dimethyl benzyl ammonium chloride

    Institute of Scientific and Technical Information of China (English)

    HU Yue-hua; OUYANG Kui; CAO Xue-feng; ZHANG Li-min

    2008-01-01

    Tertiary amine was synthesized from fatty amine and formaldehyde. And then the synthesized tertiary amine was used toreact with benzyl chloride to synthesize hexadecyl dimethyl benzyl ammonium chloride (1627) at ambient pressure. Using thesynthesized 1627 as collector, the flotation properties of diaspore and kaolinite were investigated by single mineral and mixedmineral test. The flotation mechanism of diaspore, kaolinite and 1627 was discussed based on FTIR spectra. The results show that themass ratio of aluminum to silicate achieves 15.02 and the recovery of alumina in concentrate is 43.07% using 1627 as a collector. The 1627 is found to be a more effective and a promising collector for reverse flotation to remove aluminum-silicate minerals frombauxite.

  20. Cloreto de n-(2-hidroxil propil-3-trimetil amônio quitosana como adsorvente de corantes reativos em solução aquosa Chitosan-n-2-hydroxypropyl trimethyl ammonium chloride as adsorbent for the removal of the reactive dye from aqueous solutions

    Directory of Open Access Journals (Sweden)

    Valfredo T. Fávere

    2010-01-01

    Full Text Available The quaternary chitosan was synthesized by reaction of chitosan with glycidyl trimethylammonium chloride. it was characterized by infrared spectra and conductometric titration. Adsorption of reactive blue 4 (RB4 and reactive red 120 (RR120 by quaternary chitosan was studied from aqueous medium. Two kinetic adsorption models were tested: pseudo first-order and pseudo second-order. The experimental data best fitted the pseudo second-order model. The Langmuir isotherm model provided the best fit to the equilibrium data in the concentration range investigated and the maximum adsorption capacity determined was 415 mg (RR120 and 637 mg (RB4 of reactive dye per gram of adsorbent.

  1. PREPARATION AND PHOTOSENSITIVITY OF WATER SOLUBLE PHENOLIC RESINS CONTAINING ACRYLOYL AND QUATERNARY AMMONIUM CHLORIDE GROUPS

    Institute of Scientific and Technical Information of China (English)

    Xiao-ming Tan; Hong-quan Xie; Nai-yu Huang

    2002-01-01

    New water soluble and photocrosslinkable prepolymers containing acrylate and quaternary ammonium salt groups were synthesized from epoxy phenolic resin via ring-opening reaction with acrylic acid and with aqueous solution of triethylamine hydrochloride successively. The second reaction needs no phase transfer catalyst to accelerate, since the product formed can act as a phase transfer catalyst. The prepolymer obtained contains both photocrosslinkable acrylate groups and hydrophilic quaternary ammonium salt groups. Optimum conditions for these reactions were studied. The photosensitivity of the prepolymer was also investigated. The effects of different photoinitiators, different crosslinkable diluent monomers and amine accelerator on the photosensitivity of the prepolymer were compared. The photoinitiator of hydrogen abstraction type is still effective without using amine or alcohol as accelerator, because the prepolymer contains α H beside the OH groups formed in the ring-opening reactions.

  2. Antioxidant Potential of Momordica Charantia in Ammonium Chloride-Induced Hyperammonemic Rats

    Directory of Open Access Journals (Sweden)

    A. Justin Thenmozhi

    2011-01-01

    Full Text Available The present study was aimed to investigate the antioxidant potential of Momordica charantia fruit extract (MCE in ammonium chloride-induced (AC hyperammonemic rats. Experimental hyperammonemia was induced in adult male Wistar rats (180–200 g by intraperitoneal injections of ammonium chloride (100 mg kg−1 body weight thrice a week. The effect of oral administration (thrice a week for 8 consecutive weeks of MCE (300 mg kg−1 body weight on blood ammonia, plasma urea, serum liver marker enzymes and oxidative stress biomarkers in normal and experimental animals was analyzed. Hyperammonemic rats showed a significant increase in the activities of thiobarbituric acid reactive substances, hydroperoxides and liver markers (alanine transaminase, aspartate transaminase and alkaline phosphatase, and the levels of glutathione peroxidase, superoxide dismutase, catalase and reduced glutathione were decreased in the liver and brain tissues. Treatment with MCE normalized the above-mentioned changes in hyperammonemic rats by reversing the oxidant-antioxidant imbalance during AC-induced hyperammonemia, and offered protection against hyperammonemia. Our results indicate that MCE exerting the antioxidant potentials and maintaining the cellular integrity of the liver tissue could offer protection against AC-induced hyperammonemia. However, the exact underlying mechanism is yet to be investigated, and examination of the efficacy of the active constituents of the M. charantia on hyperammonemia is desirable.

  3. Levels of ammonium, sulfate, chloride, calcium, and sodium in snow and ice from southern Greenland

    International Nuclear Information System (INIS)

    Chemical analysis of surface snows and dated ice core samples from Dye 3, Greenland, suggests that the ammonium cation is a major constituent in all samples and that the annual ammonium levels present in the south Greenland samples have varied from 3.3 to 26.3 μg/kg between the seventeenth century and the present time. The annual range of 1974--1975 surface samples was between 3.8 and 8.8 μg/kg, while the mean was 5.7 +- 1.8 μ/kg. The recent large-scale uses of fixed nitrogen fertilizers and industrial pollution have apparently not affected the levels of ammonia reaching southern Greenland. The sodium and chloride present are predominantly derived from ocean spray, while more than 90% of the calcium is of continental origin. The levels of these three elements have not apparently been affected by human activity since the industrial revolution. Sulfate levels have increased dramatically since the industrial revolution, suggesting that sulfate of anthropogenic origin is the most important source of sulfate in modern snows from southern Greenland. The amount of the sulfuric acid neutralized by the ammonium cations was approximately 100% in the seventeenth and eighteenth centuries, dropping to approximately 20% in the 1974--1975 samples. These figures imply that there has been in increase in the acidity of precipitation in southern Greenland since the end of the eighteenth ce

  4. Adsorption of Tetradecylpyridinium Chloride on Aqueous Surfaces of Sodium Chloride Solutions

    OpenAIRE

    Fujio, Katsuhiko; Hayashi, Koji; Suzuki, Maki

    2014-01-01

    Surface tension of aqueous NaCl solutions of tetradecylpyridinium chloride (TPC) has been measured by the drop weight method at different NaCl concentrations from 0 to 1.000 mol dm−3 at 25◦C. Surface excess densities of tetradecylpyridinium ion (TP+), Cl− and Na+ have been obtained as functions of TPC concentration at different NaCl concentrations by applying the Gibbs adsorption isotherm to the surface tension data below the critical micelle concentration (CMC) of TPC. Surface excess densiti...

  5. Adsorption of Dodecylpyridinium Chloride on Aqueous Surfaces of Sodium Chloride Solutions

    OpenAIRE

    Fujio, Katsuhiko; TAKEUCHI, Kumiko; Suzuki, Maki

    2012-01-01

    Surface tension of aqueous NaCl solutions of dodecylpyridinium chloride (DPC) has been measured by the drop weight method at different NaCl concentrations from 0 to 1.000 mol dm-3 at 25℃. Applying the Gibbs adsorption isotherm to the surface tension data at DPC concentrations below the critical micelle concentration (CMC), surface excess densities of dodecylpyridinium ion (DP+), Cl- and Na+ have been obtained as functions of DPC concentration at different NaCl concentrations. Surface excess d...

  6. A hybridization approach to efficient TiO{sub 2} photodegradation of aqueous benzalkonium chloride

    Energy Technology Data Exchange (ETDEWEB)

    Suchithra, Padmajan Sasikala, E-mail: schithraps@gmail.com [Research group of Applied and Analytical Chemistry, University Hasselt, Agoralaan, Gebouw D, BE-3590 Diepenbeek (Belgium); Carleer, Robert [Research group of Applied and Analytical Chemistry, University Hasselt, Agoralaan, Gebouw D, BE-3590 Diepenbeek (Belgium); Ananthakumar, Solaippan [Materials Science and Technology Division, National Institute for Interdisciplinary Science and Technology (CSIR), Trivandrum 695019 (India); Yperman, Jan, E-mail: jan.yperman@uhasselt.be [Research group of Applied and Analytical Chemistry, University Hasselt, Agoralaan, Gebouw D, BE-3590 Diepenbeek (Belgium)

    2015-08-15

    Graphical abstract: Hybridization of AC onto TiO{sub 2} tends the catalyst surface negatively charged besides providing highly favorable adsorptions sites for cationic surfactants. The photodegradation of benzalkonium chloride (BKC) is investigated. - Highlights: • Activated carbon-TiO{sub 2} composite (ACT) surface tends negative upon UV irradiation. • ACT effectively photodegrade cationic surfactant benzalkonium chloride (BKC). • Optimum pH for UV-photodegradation of BKC is 8 to 9 and reaction time is 2 h. • Aromatic moiety of BKC is degraded faster than long alkyl chain. • UV–vis spectroscopy is sensitive to detect aqueous BKC from 1 μg/mL. - Abstract: TiO{sub 2} get positively charged upon UV-irradiation and repel the cationic pollutants away from the surface. Hybridization of AC onto TiO{sub 2} (ACT) tends catalyst surface negatively charged besides providing highly favorable adsorptions sites for cationic pollutants. The photodegradation of benzalkonium chloride (BKC), a quaternary ammonium surfactant and a pharmaceutical, is investigated with ACT. The surface charge of the catalyst in surfactant and non-surfactant aqueous dispersion under UV-irradiation is investigated and explained. The anomalous increase in COD values at the beginning of BKC-photodegradation is explained. The intermediate products formed are identified in both solution and solid phase. Trace amount of dodecane remained adsorbed on the catalyst surface after 1 h UV-irradiation, but complete mineralization of BKC is achieved with 2 h UV-irradiation. We propose that BKC photodegradation starts by central fission of benzyl C−N bond followed by dealkylation, and demethylation steps.

  7. Epoxidation of Alkenes with Aqueous Hydrogen Peroxide and Quaternary Ammonium Bicarbonate Catalysts

    DEFF Research Database (Denmark)

    Mielby, Jerrik Jørgen; Kegnæs, Søren

    2013-01-01

    A range of solid and liquid catalysts containing bicarbonate anions were synthesised and tested for the epoxidation of alkenes with aqueous hydrogen peroxide. The combination of bicarbonate anions and quaternary ammonium cations opens up for new catalytic systems that can help to overcome challen...

  8. Radiolysis of aqueous solutions of ammonium bicarbonate over a large dose range

    DEFF Research Database (Denmark)

    Draganic, Z.D.; Negrón-Mendoza, A.; Sehested, K.;

    1991-01-01

    Oxygen-free aqueous solutions of 0.05 mol dm-3 ammonium and sodium bicarbonate were studied after receiving various doses of Co-60 gammas (0.01-400 kGy) or 0.5-20 Gy pulses of 10 Mev electrons. Formate and oxalate were found to be the main radiolytic products, in addition to trace amounts...

  9. Radiation Stability of Benzyl Tributyl Ammonium Chloride Towards Technetium-99 Extraction

    Energy Technology Data Exchange (ETDEWEB)

    Jared Horkley; Audrey Roman; Keri Campbell; Ana Nunez; Amparo Espartero

    2013-02-01

    investigate the suitability of new macrocompounds such as crown-ethers, aza-crown ethers, and resorcinarenes for the selective extraction of Tc-99 from nitric acid solutions. The selectivity of the ligand is important in evaluating potential separation processes and also the radiation stability of the molecule is essential for minimization of waste and radiolysis products. In this paper, we are reporting the extraction of TcO4- by benzyltributyl ammonium chloride (BTBA). Experimental efforts were focused on determining the best extraction conditions by varying the ligand’s matrix conditions and concentration, as well as varying the organic phase composition (i.e., diluent variation). Furthermore, the ligand has been investigated for radiation stability. The ?-irradiation was performed on the neat organic phases containing the ligand at different absorbed doses to a maximum of 200 kGy using external Co-60 source. Post-irradiation solvent extraction measurements will be discussed.

  10. Effect of Ammonium Chloride Solution on the Growth of Phosphorus Gypsum Whisker and Its Modification

    Directory of Open Access Journals (Sweden)

    Shouwei Jian

    2016-01-01

    Full Text Available Phosphogypsum is the by-product of phosphate of fertilizer or phosphate which causes serious environmental pollution. In this work, a series of phosphogypsum whiskers were prepared using phosphogypsum as raw materials and NH4Cl as additive through the atmospheric water solution method. The results showed that the ammonium chloride solution has a great influence on phosphogypsum whiskers growth and the solubility. The best whisker aspect ratio of phosphogypsum was preferred in 1 mol/L NH4Cl solution, in which the solubility achieved 6.434 mg/mL and the aspect ratio reached 69.29. Besides, NH4Cl was found to have a modified effect on gypsum whiskers’ growth and it can be used to get mesh or dendritic whiskers.

  11. Effects of propofol on ammonium chloride-exposed astrocyte morphology and aquaporin-4 expression

    Institute of Scientific and Technical Information of China (English)

    Hanjian Chen; Caifei Pan; Peng Guo; Yueying Zheng; Shengmei Zhu

    2011-01-01

    Ammonia induces astrocyte swelling, which is strongly associated with overexpression of aquaporin-4.However, the mechanisms by which ammonia induces astrocyte swelling, and subsequently upregulating aquaporin-4 expression, remain unknown.In the present study,astrocytes were cultured in vitro and exposed to ammonium chloride (NH4CI), followed by propofol,protein kinase C agonist, or antagonist, respectively.Astrocyte morphology was observed by light microscopy, and aquaporin-4 expression was detected by western blot analysis.Results showed that propofol or protein kinase C agonist significantly attenuated the degree of NH4CI-induced astrocyte swelling and inhibited increased aquaporin-4 expression.Propofol treatment inhibited aquaporin-4 overexpression in cultured astrocyte induced by NH4CI; protein kinase C pathway activation is potentially involved.

  12. β-CD assisted dissolution of quaternary ammonium permanganates in aqueous medium.

    Science.gov (United States)

    Bank, Suraj Prakash; Guru, Partha Sarathi; Dash, Sukalyan

    2014-10-13

    The non-polar internal cavity of β-cyclodextrin (β-CD) has been exploited for the entrapment of the hydrophobic tails of two water insoluble quaternary ammonium permanganates (QAPs): cetyltrimethylammonium permanganate (CTAP) and tetrabutylammonium permanganate (TBAP), for solubilization in aqueous medium. The solubilization and organizational behavior of the QAPs in aqueous β-CD solution have been determined from the comparison of their rates of self-oxidation in presence and in absence of β-CD. Effect of QAP concentration on their observed rate constants (k(obs)) at a fixed β-CD concentration, phase solubility analysis in varying β-CD concentration, impact of quaternary ammonium bromides (QABs) on the kobs values of CTAP and TBAP at fixed QAP and β-CD concentrations, and the temperature effect have been reported. A scheme to explain the solvation of QAPs in aqueous β-CD has been proposed based on dynamic light scattering (DLS) analysis of the samples.

  13. Monte Carlo Studies of the Orientational Order-Disorder Phase Transition in Solid Ammonium Chloride

    CERN Document Server

    Topper, R Q; Topper, Robert Q.; Freeman, David L.

    1994-01-01

    Monte Carlo methods are used to study the phase transition in ammonium chloride from the orientationally ordered $\\delta$ phase to the orientationally disordered $\\gamma$ phase. An effective pair potential is used to model the interaction between ions. Thermodynamic properties are computed in the canonical and isothermal-isobaric ensembles. Each ammonium ion is treated as a rigidly rotating body and the lattice is fixed in the low-temperature CsCl geometry. A simple extension of the Metropolis Monte Carlo method is used to overcome quasiergodicity in the rotational sampling. In the constant-$NVT$ calculations the lattice is held rigid; in the constant-$NpT$ calculations the lattice parameter is allowed to fluctuate. In both ensembles the order parameter rapidly falls to zero in the range (200 - 250)K, suggesting that the model disorders at a temperature in fair agreement with the experimental disordering temperature (243K). Peaks in the heat capacity and thermal expansivity curves are also found in the same t...

  14. Alanine synthesis from glyceraldehyde and ammonium ion in aqueous solution

    Science.gov (United States)

    Weber, A. L.

    1985-01-01

    The formation of alanine (ala) form C(14)-glyceraldehyde and ammonium phosphate in the presence or absence of a thiol is reported. At ambient temperature, ala synthesis was six times more rapid in the presence of 3-mercaptopropionic acid than in its absence (0.6 and 0.1 percent, respectively, after 60 days). Similarly, the presence of another thiol, N-acetylcysteinate, increased the production of ala, as well as of lactate. The reaction pathway of thiol-catalyzed synthesis of ala, with the lactic acid formed in a bypath, is suggested. In this, dehydration of glyceraldehyde is followed by the formation of hemithioacetal. In the presence of ammonia, an imine is formed, which eventually yields ala. This pathway is consistent with the observation that the rate ratio of ala/lactate remains constant throughout the process. The fact that the reaction takes place under anaerobic conditions in the presence of H2O and with the low concentrations of simple substrates and catalysts makes it an attractive model prebiotic reaction in the process of molecular evolution.

  15. The extraction of zinc and other minor metals from concentrated ammonium chloride solutions with D2EHPA and Cyanex 272

    Directory of Open Access Journals (Sweden)

    Amer, S.

    1995-12-01

    Full Text Available A comparative study is made of the extractants D2EHPA and Cyanex 272 for the zinc and minor metal extraction from aqueous concentrated ammonium chloride solutions, as those of the leaching liquors of the CENIM-LNETI process. Extraction equilibrium data for zinc are presented as extraction isotherms at constant pH and at a temperature of 50 °C. Zinc extraction and coextraction of minor metal ions as Cu, Ca, Pb, Mg, Cd, Co, Ni and Hg are studied. Mercury does not extract from concentrated ammonium chloride solutions. Cyanex 272 shows a better selectivity for zinc with regard to the minor metals than D2EHPA, which is especially remarkable for calcium, the most coextracted element by D2EHPA. Nickel and cadmium coextraction is negligible for both extractants. The possible use of the Cyanex 272 as an alternative to D2EHPA is considered.

    Se realiza un estudio comparativo del comportamiento del D2EHPA y del Cyanex 272 durante la extracción del cinc y otros metales minoritarios de soluciones acuosas concentradas de cloruro amónico, como las de las soluciones de lixiviación del proceso CENIM-LNETI. Se presentan los datos de equilibrio de extracción del cinc en forma de isotermas de extracción a una temperatura de 50 °C y pH constante y se estudia la coextracción de los metales minoritarios Cu, Ca, Pb, Mg, Cd, Co, Ni y Hg. El mercurio no se extrae de las soluciones concentradas de cloruro amónico. La selectividad del Cyanex 272 para el cinc respecto de esos metales minoritarios es mejor que la del D2EHPA, siendo verdaderamente notable para el calcio, que es la impureza que más se coextrae con el D2EHPA. La coextracción de níquel y de cadmio es muy pequeña para ambos extractantes. Se considera la posibilidad del uso alternativo del Cyanex 272 en lugar del D2EHPA.

  16. Impact of hydrotreaters ammonium chloride salt deposition of refinery operations; Formacao de depositos de sais de amonio em Unidades de Hidrotramento (HDT'S)

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Nelmo Furtado; Cunha, Fabiana A.; Alvise, Paulo Pio [PETROBRAS, Rio de Janeiro, RJ (Brazil)

    2008-07-01

    Fouling and consequent under deposit corrosion caused by ammonium salts, especially ammonium chloride, have serious impact on the reliability of operation of various process units. In hydrotreating units salt deposition on heat exchanger tubes causes a decrease in heat transfer efficiency, decrease hydrotreating efficiency, increased pressure drops, and corrosion. This paper will discuss the causes of ammonium chloride fouling,methods to help prevent and/or mitigate the fouling, and provide a case history demonstrating the effects of ammonium chloride formations in one refinery operation. (author)

  17. Phase and extraction equilibria in water-polyethyleneglycol ethers of monoethanolamides of synthetic fatty acid-ammonium chloride systems

    Science.gov (United States)

    Lesnov, A. E.; Golovkina, A. V.; Kudryashova, O. S.; Denisova, S. A.

    2016-08-01

    Phase equilibria in layering systems of water, polyethyleneglycol ethers of monoethanolamides of synthetic fatty acids (SFAs) (synthamide-5), and ammonium chloride are studied. The possibility of using such systems for the liquid extraction of metal ions is evaluated. The effect the nature of salting-out agents has on the processes of segregation of the systems has been considered.

  18. Aqueous ammonium thiocyanate solutions as refractive index-matching fluids with low density and viscosity

    CERN Document Server

    Borrero-Echeverry, Daniel

    2016-01-01

    We show that aqueous solutions of ammonium thiocyanate (NH4SCN) can be used to match the index of refraction of several transparent materials commonly used in experiments, while maintaining low viscosity and density compared to other common refractive index-matching liquids. We present empirical models for estimating the index of refraction, density, and kinematic viscosity of these solutions as a function of temperature and concentration. Finally, we summarize some of the chemical compatibility of ammonium thiocyanate with materials commonly used in apparatus.

  19. Floc flotation of jamesonite fines in aqueous suspensions induced by ammonium dibutyl dithiophosphate

    Institute of Scientific and Technical Information of China (English)

    张婷; 覃文庆

    2015-01-01

    The hydrophobic flocculation of jamesonite fines in aqueous suspensions induced by ammonium dibutyl dithiophosphate was investigated using laser particle size analysis, microscope analysis, electrophoretic light scattering and infrared spectroscopy. Single minerals of 4.607 µm for the 50% volumetric diameters were researched by varying several parameters, including pH, ammonium dibutyl dithiophosphate concentration, stirring strength and kerosene addition. It is found that the maximal floatability of jamesonite fines is induced by ammonium dibutyl dithiophosphate at pH 6, and the floc flotation increases with increasing ammonium dibutyl dithiophosphate concentration despite a simultaneous increase in the negativeζpotential of jamesonite, meaning that hydrophobic interaction between the particles increases much more strongly than electric double layer repulsion from the adsorption of ammonium dibutyl dithiophosphate. It is also found that the floc flotation is closely correlated with the size of flocs, which is strongly influenced by the stirring strength and enhanced by the addition of a small amount of kerosene. The results of FTIR spectra indicate that adsorption of ammonium dibutyl dithiophosphate onto jamesonite is chemical adsorption and the adsorption product is lead dibutyl dithiophosphate.

  20. Determination of the Optimum Conditions for Leaching of Zinc Cathode Melting Furnace Slag in Ammonium Chloride Media

    Science.gov (United States)

    Behnajady, Bahram; Babaeidehkordi, Amin; Moghaddam, Javad

    2014-04-01

    This research is part of a continuing effort to leach zinc from zinc cathode melting furnace slags (ZCMFSs) to produce zinc oxide. The slag with an assay of 68.05 pct Zn was used in ammonium chloride leaching for zinc extraction. In this paper, the effects of influential factors on extraction efficiency of Zn from a ZCMFS were investigated. The Taguchi's method based on orthogonal array (OA) design has been used to arrange the experimental runs in order to maximize zinc extraction from a slag. The softwares named Excel and Design-Expert 7 have been used to design experiments and subsequent analysis. OA L 25 (55) consisting of five parameters, each with five levels, was employed to evaluate the effects of reaction time ( t = 10, 30, 50, 70, 90 minutes), reaction temperature [ T = 313, 323, 333, 343, 353 (40, 50, 60, 70, 80) K (°C)], pulp density ( S/ L = 20, 40, 60, 80, 100 g/L), stirring speed ( R = 300, 400, 500, 600, 700 rpm), and ammonium chloride concentration ( C = 10, 15, 20, 25, 30 pctwt), on zinc extraction percent. Statistical analysis, ANOVA, was also employed to determine the relationship between experimental conditions and yield levels. The results showed that the significant parameters affecting leaching of slag were ammonium chloride concentration and pulp density, and increasing pulp density reduced leaching efficiency of zinc. However, increasing ammonium chloride concentration promoted the extraction of zinc. The optimum conditions for this study were found to be t 4: 70 minutes, T 5: 353 K (80 °C), ( S/ L)2: 40 g/L, R 3: 500 rpm, and C 4: 25 pctwt. Under these conditions, the dissolution percentage of Zn in ammonium chloride media was 94.61 pct.

  1. An Electronic Tongue Designed to Detect Ammonium Nitrate in Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    Inmaculada Campos

    2013-10-01

    Full Text Available An electronic tongue has been developed to monitor the presence of ammonium nitrate in water. It is based on pulse voltammetry and consists of an array of eight working electrodes (Au; Pt; Rh; Ir; Cu; Co; Ag and Ni encapsulated in a stainless steel cylinder. In a first step the electrochemical response of the different electrodes was studied in the presence of ammonium nitrate in water in order to further design the wave form used in the voltammetric tongue. The response of the electronic tongue was then tested in the presence of a set of 15 common inorganic salts; i.e.; NH4NO3; MgSO4; NH4Cl; NaCl; Na2CO3; (NH42SO4; MgCl2; Na3PO4; K2SO4; K2CO3; CaCl2; NaH2PO4; KCl; NaNO3; K2HPO4. A PCA plot showed a fairly good discrimination between ammonium nitrate and the remaining salts studied. In addition Fuzzy Art map analyses determined that the best classification was obtained using the Pt; Co; Cu and Ni electrodes. Moreover; PLS regression allowed the creation of a model to correlate the voltammetric response of the electrodes with concentrations of ammonium nitrate in the presence of potential interferents such as ammonium chloride and sodium nitrate.

  2. Ammonium Chloride Ingestion Attenuates Exercise-Induced mRNA Levels in Human Muscle.

    Directory of Open Access Journals (Sweden)

    Johann Edge

    Full Text Available Minimizing the decrease in intracellular pH during high-intensity exercise training promotes greater improvements in mitochondrial respiration. This raises the intriguing hypothesis that pH may affect the exercise-induced transcription of genes that regulate mitochondrial biogenesis. Eight males performed 10x2-min cycle intervals at 80% VO2speak intensity on two occasions separated by ~2 weeks. Participants ingested either ammonium chloride (ACID or calcium carbonate (PLA the day before and on the day of the exercise trial in a randomized, counterbalanced order, using a crossover design. Biopsies were taken from the vastus lateralis muscle before and after exercise. The mRNA level of peroxisome proliferator-activated receptor co-activator 1α (PGC-1α, citrate synthase, cytochome c and FOXO1 was elevated at rest following ACID (P0.05; the difference in PGC-1α mRNA content 2 h post-exercise between ACID and PLA was not significant (P = 0.08. Thus, metabolic acidosis abolished the early post-exercise increase of PGC-1α mRNA and the mRNA of downstream mitochondrial and glucose-regulating proteins. These findings indicate that metabolic acidosis may affect mitochondrial biogenesis, with divergent responses in resting and post-exercise skeletal muscle.

  3. Phase equilibrium conditions of semi-calthrate hydrates of (tetra-n-butyl ammonium chloride + carbon dioxide)

    International Nuclear Information System (INIS)

    Highlights: • Carbon dioxide hydrate stability zone was enlarged with the help of TBAC. • Carbon dioxide uptake into TBAC semi-clathrate hydrates is confirmed. • Equilibrium pressure of hydrate decreased with the increase of TBAC mass concentration. • The addition of TBAC reduces the formation pressures of carbon dioxide hydrate by 2.5 MPa. - Abstract: In the present work, hydrate equilibrium conditions for (tetra-n-butyl ammonium chloride (TBAC) + carbon dioxide + water) mixtures were investigated. Tetra-n-butyl ammonium chloride was reported to form a semi-clathrate hydrate. The experiments were carried out within the TBAC mass fraction range of (0.05 to 0.3). The experimental results showed that the presence of TBAC decreased the formation pressure of carbon dioxide double hydrate within the experimental temperature range. Moreover, pressure reduction was dependent on the TBAC concentration

  4. EFFECT OF NONI (Morinda citrifolia EXTRACT ON TREATMENT OF ETHYLENE GLYCOL AND AMMONIUM CHLORIDE INDUCED KIDNEY DISEASE

    Directory of Open Access Journals (Sweden)

    R Bhavani

    2014-06-01

    Full Text Available Morinda citrifolia is one of the important medicinal plants having a lot of phytochemicals, which plays very important role in medicines. In this present investigation, the animals are induced to kidney stone by giving ethylene glycol mixed with water and given orally, and 0.5 % ammonium chloride are mixed with water and given orally for 28 days. The induced rats are treated with Noni (1 in 10 ml mixed with H2O and given to the rats for 28 days, and induced to kidney stone + ammonium chloride is treated with Noni extract mixed with water and given to the rats for 28 days. After the treatment the urinary parameters like creatinine, protein, calcium, oxalate, phosphate are decreased except magnesium, its level is increased and serum creatinine level is decreased. The results are shows the good medicinal properties of noni extract of Morinda citrifolia.

  5. Selective process of zinc extraction from spent Zn–MnO2 batteries by ammonium chloride leaching

    OpenAIRE

    Nogueira, C. A.; Margarido, F.

    2015-01-01

    Recycling of spent Zn-MnO2 batteries by hydrometallurgy is usually carried out by leaching in acid media, mainly with sulphuric acid solutions. Another type of leachant was used in this work, specifically solutions of concentrated ammonium chloride. The development of this study has relied on the prediction of the chemical behavior of the constituting phases based on data obtained from theoretical and experimental equilibrium values. The assessment of the effects of factors on leaching effici...

  6. Densities, refractive indices, and viscosities of N,N-diethylethanol ammonium chloride–glycerol or –ethylene glycol deep eutectic solvents and their aqueous solutions

    International Nuclear Information System (INIS)

    Highlights: • The densities, refractive indices, and viscosities of aqueous DES solutions were measured. • DES are made from N,N-diethylethanol ammonium chloride + glycerol or ethylene glycol. • The temperature studied was (298.15 to 343.15) K. • The measured data were reported as functions of temperature and composition. • The measured data were represented satisfactorily by the applied correlations. -- Abstract: In this work, we report new experimental data on density, ρ, refractive index, nD, and viscosity, η, of two deep eutectic solvents, N,N-diethylethanol ammonium chloride–glycerol (DEACG) and N,N-diethylethanol ammonium chloride–ethylene glycol (DEACEG), and their aqueous solutions, over the complete composition range, at temperatures from (298.15 to 343.15) K. Densities and viscosities were measured using the vibrating tube and the falling ball techniques, respectively, while the refractive index at the sodium D line was measured using an automatic refractometer. We aimed to represent the measured properties as a function of temperature and composition, and correlated them using the Redlich–Kister-type equation, for density, a polynomial function, for refractive index, and the Vogel–Fulcher–Tammann (VFT) equation, for viscosity

  7. Environmental assessment of an alkyl dimethyl benyzl ammonium chloride (ADBAC) based mollusicide using laboratory tests

    Energy Technology Data Exchange (ETDEWEB)

    Dobbs, M.G.; Cherry, D.S.; Scott, J.C. [Virginia Tech, Blacksburg, VA (United States); Petrille, J.C. [Betz Water Management Center, Trevose, PA (United States)

    1995-06-01

    A series of acute and chronic toxicity tests were conducted to estimate the potential environmental impact of n-alkyl dimethyl benzyl ammonium chloride (ADBAC) when used to control zebra mussels and other types of macrofouling organism in industrial cooling systems. The ADBAC-based molluscicide was tested as pure product and often detoxification with bentonite clay. Six flow-through acute tests were conducted to estimate the toxicity of ADBAC. In addition three chronic toxicity tests using Pimephales promelas, Daphnia magna and Selenastrum capricornutum were carried out to evaluate the efficacy of complexing the ADBAC-based molluscicide with a bentonite clay as a detoxification strategy. A 29-day CO{sub 2} Production test was also conducted to evaluate the biodegradability of the molluscicide. Of the six species tested in acute flow-through experiments, D. magna (LC{sub 50} = 0.02 mg ADBAC/L) was the most sensitive species followed by Mysidopsis bahia (LC{sub 50} = 0.08 mg ADBAC/L), Menidia beryllina (LC{sub 50} = 0.88 mg ADBAC/L), P. promelas (LC{sub 50} = 0.36 mg ADBAC/L), Cyprinodon variegatus (LC{sub 50} = 0.88 mg ADBAC/L), and Oncorhynchus mykiss (LC{sub 50} = 1.01 mg ADBAC/L). In the detoxification studies the three test species were exposed to treatment levels of: 0:0, 2.5:0, 2.5:25, 2.5:37.5, 2.5:50, 2.5:75, and 0:75 as mg/L ADBAC:clay. Bentonite clay was found to be an effective detoxification agent for this molluscicide at all treatment levels, except for the 2.5:25 treatment. In addition, a biodegradation study showed that the ADBAC-based molluscicide was readily biodegradable by unacclimated activated sludge microorganisms releasing 65.9% of the theoretical possible CO{sub 2} after 29 days.

  8. Cultivation of Spirulina platensis by continuous process using ammonium chloride as nitrogen source

    Energy Technology Data Exchange (ETDEWEB)

    Sassano, C.E.N.; Gioielli, L.A.; Almeida, K.A.; Sato, S.; Carvalho, J.C.M. [Department of Biochemical and Pharmaceutical Technology, Faculty of Pharmaceutical Sciences, University of Sao Paulo, Av. Prof. Lineu Prestes 580, Bloco 16, 05508-900 Sao Paulo-SP (Brazil); Perego, P.; Converti, A. [Department of Chemical and Process Engineering ' ' G.B. Bonino' ' , University of Genoa, via Opera Pia 15, 16145 Genoa (Italy)

    2007-08-15

    This work is focused on the influence of dilution rate (0.08{<=}D{<=}0.32 d{sup -1}) on the kinetics of continuous cultivation of Spirulina platensis at two different concentrations of ammonium chloride (N{sub 0}=1.0 and 10 mM) as nitrogen source. Cell productivity increased in both series of runs up to D{approx_equal}0.12-0.16 d{sup -1}, and then decreased. While at N{sub 0}=1.0 mM biomass washing was certainly the cause of progressive cell concentration decrease, a combination of this phenomenon with the toxic effect of excess ammonia was responsible, at N{sub 0}=10 mM and D{>=}0.20 d{sup -1}, for quick stop of cell growth just beyond the achievement of maximum cell productivity (92.4 mg l{sup -1} d{sup -1}). Similar profile was observed for protein productivity, that achieved a maximum value of 67.0 mg l{sup -1} d{sup -1}, because of the very high protein content (72.5%) of biomass produced under these conditions. The yield of nitrogen-to-biomass was much higher at the lower N{sub 0}, because of the low protein content, and reached a maximum value of 9.7 g g{sup -1} at D=0.08-0.12 d{sup -1}. The yield of nitrogen-to-protein showed less marked difference, being most of the nitrogen present in the cell as proteins or free amino-acids. (author)

  9. Aqueous Solution Preparation of Ruthenium Nanoparticles Using Ammonium Formate as the Reducing Agent

    Institute of Scientific and Technical Information of China (English)

    LIU Shaohong; CHEN Jialin; GUAN Weiming; BI Jun; CHEN Nanguang; CHEN Dengquan; LIU Manmen; SUN Xudong

    2012-01-01

    Ruthenium,one of the platinum group metals,has drawn much attention due to its catalytic behavior,hardness,electrical conductivity and density.Ruthenium particles are usually prepared on a small scale by the polyol process,however,the size of the obtained ruthenium nanoparticles is most below 10 nm.In this work,ruthenium particles about 200 nm in diameter were obtained in aqueous solution by using ammonium formate as the reducing agent.Tohave a better control of particle's size and shape,the effects of PVP,mixing mode,reaction temperature,solution pH and calcination temperature were investigated.

  10. 甲醇氯化铵法合成氯甲烷催化剂%Synthesis of Methyl Chloride from Methanol and Ammonium Chloride

    Institute of Scientific and Technical Information of China (English)

    魏士东; 张文娇; 孙玉捧; 刘玉敏; 胡永其; 付应利

    2012-01-01

    Metal-based catalysts carried on activated carbon support for synthesis of methyl chloride from methanol and ammonium chloride were prepared with /so-volumetric impregnation of Zn(NO3)2, Ni(CH3COO)2, Zn(CH3COO)2, Ni(NO3)2 and ZnCl2, respectively. The catalytic performance of the catalysts for synthesis of methyl chloride from methanol and ammonium chloride were evaluated in a laboratory fixed bed reactor fed. The experimental results showed that the catalyst prepared with ZnCb impregnation method exhibited the best catalytic performance under the conditions of temperature of 290-350 °C, molar ratio of methanol to hydrogen chloride of 1:1, and space velocity of 300 min-1. The yield of ammonium chloride reached up to 66%. Moreover, the catalyst was stable and had a long life time.%采用等体积浸渍法,分别以Zn(NO3)2,Ni(CH3COO)2,Zn(CH3COO)2,Ni(NO3)2和ZnCl2作为负载物制备了活性炭载体金属基催化剂,在自制的常压连续流动固定床反应器中,以氯化氢和甲醇为原料,在氨环境下模拟氯化铵与甲醇反应考察了不同催化剂在合成氯甲烷中的催化性能.结果表明,以活性炭为载体制备的氯化锌催化剂,在温度290~350℃,氯化氢和甲醇物质的量之比为1∶1和空速300 min-1的条件下,甲醇转化率、氯甲 烷选择性和收率较高,氯甲烷收率达到66%以上.催化剂性能稳定,且有较长的使用寿命.

  11. Adsorption of ammonium dinitramide (ADN) from aqueous solutions. 1. Adsorption on powdered activated charcoal.

    Science.gov (United States)

    Santhosh, G; Venkatachalam, S; Ninan, K N; Sadhana, R; Alwan, S; Abarna, V; Joseph, M A

    2003-03-17

    Investigations on the adsorption of ammonium dinitramide (NH(4)N(NO(2))(2)) (ADN) from aqueous solutions on powdered activated charcoal (PAC) were carried out in order to find out an effective and easier method of separating ADN from aqueous solutions. The effectiveness of PAC in the selective adsorption of ADN from aqueous solutions of ADN (ADN-F) and ADN in presence of sulfate (SO(4)(2-)) and nitrate (NO(3)(-)) ions (ADN-PS) was examined and compared using batch and column methods. The adsorption process follows both Langmuir and Freundlich adsorption isotherms and the isotherm parameters for the models were determined. The observed data favor the formation of monolayer adsorption. The adsorption capacities were found to be 63.3, 119, 105.3 and 82 mg of ADN per g of PAC for ADN-F (batch), ADN-PS (batch), ADN-F (column) and ADN-PS (column), respectively. Break-through curves for ADN-F and ADN-PS were obtained for the optimization of separation of ADN from aqueous solutions. Elution curves were generated for the desorption of ADN from PAC using hot water as eluent.

  12. Adsorption of ammonium dinitramide (ADN) from aqueous solutions. 1. Adsorption on powdered activated charcoal.

    Science.gov (United States)

    Santhosh, G; Venkatachalam, S; Ninan, K N; Sadhana, R; Alwan, S; Abarna, V; Joseph, M A

    2003-03-17

    Investigations on the adsorption of ammonium dinitramide (NH(4)N(NO(2))(2)) (ADN) from aqueous solutions on powdered activated charcoal (PAC) were carried out in order to find out an effective and easier method of separating ADN from aqueous solutions. The effectiveness of PAC in the selective adsorption of ADN from aqueous solutions of ADN (ADN-F) and ADN in presence of sulfate (SO(4)(2-)) and nitrate (NO(3)(-)) ions (ADN-PS) was examined and compared using batch and column methods. The adsorption process follows both Langmuir and Freundlich adsorption isotherms and the isotherm parameters for the models were determined. The observed data favor the formation of monolayer adsorption. The adsorption capacities were found to be 63.3, 119, 105.3 and 82 mg of ADN per g of PAC for ADN-F (batch), ADN-PS (batch), ADN-F (column) and ADN-PS (column), respectively. Break-through curves for ADN-F and ADN-PS were obtained for the optimization of separation of ADN from aqueous solutions. Elution curves were generated for the desorption of ADN from PAC using hot water as eluent. PMID:12628781

  13. Henry’s constant of carbon dioxide-aqueous deep eutectic solvent (choline chloride/ethylene glycol, choline chloride/glycerol, choline chloride/malonic acid) systems

    International Nuclear Information System (INIS)

    Highlights: • A new set of Henry’s constant for the system carbon dioxide-aqueous deep eutectic solvents were measured. • The DESs used were: ethaline, glyceline, and maline. • The measured data were reported as functions of temperature and composition. • The measured data were represented satisfactorily by the applied correlations. -- Abstract: In this study, we present a new set of Henry’s constant data for the system carbon dioxide-aqueous deep eutectic solvent (DES) (20 to 80 wt% DES) at T = (303.15, 308.15, and 313.15) K. The DESs used were choline chloride-based: ethaline (choline chloride/ethylene glycol), glyceline (choline chloride/glycerol), and maline (choline chloride/malonic acid). A differential Henry’s coefficient model was used to describe the behaviour of Henry’s constant, and correlate it with temperature and concentration of DES in the aqueous DES solution. The correlation was found satisfactory such that the proposed model can be used in engineering calculations with reasonable accuracy

  14. A facile synthesis of 2,4,6-trichloroborazine from boron trichloride-dimethylsulfide complex and ammonium chloride

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    2,4,6-Trichloroborazine has been recognized as a desirable monomer for the preparation of high-performance boron nitride fibers through polymer derived ceramics route.So a high yield and facile synthesis of 2,4,6-trichloroborazine is essential in practice. Using boron trichloride-dimethylsulfide complex((CH_3)_2S·BCl_3) and ammonium chloride(NH_4Cl) as starting materials and toluene(C_6H_5CH_3) as solvent,the synthesis of 2,4,6-trichloroborazine to give high yield is reported.

  15. Aqueous Chloride Operations Overview: Plutonium and Americium Purification/Recovery

    Energy Technology Data Exchange (ETDEWEB)

    Kimball, David Bryan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Skidmore, Bradley Evan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-06-22

    Acqueous Chloride mission is to recover plutonium and americium from pyrochemical residues (undesirable form for utilization and storage) and generate plutonium oxide and americium oxide. Plutonium oxide is recycled into Pu metal production flowsheet. It is suitable for storage. Americium oxide is a valuable product, sold through the DOE-OS isotope sales program.

  16. Ammonium removal from high-strength aqueous solutions by Australian zeolite

    DEFF Research Database (Denmark)

    Wijesinghe, D. Thushari N; Dassanayake, Kithsiri B.; Sommer, Sven G.;

    2016-01-01

    . Increased retention time and temperature generally had a positive impact on adsorption. Freundlich model fitted well with adsorption process of Australian natural zeolites; however, Langmuir model had best fitted for the adsorption process of sodium (Na+) treated zeolites. NaCl treatment increased the NH4...... to its high adsorption capacity of ammonium (NH4 +). However, detailed investigations on NH4 + adsorption and ion exchange capacities of Australian natural zeolites are rare, particularly under higher NH4 + concentrations in the medium. Therefore, this study was conducted to determine NH4 + adsorption...... characteristics of Australian natural zeolites at high NH4 + concentrations with and without other chemical compounds in an aqueous solution. Results showed that initial NH4 + concentration, temperature, reaction time, and pH of the solution had significant effects on NH4 + adsorption capacity of zeolite...

  17. INTERACTION OF POLY(SODIUM SULFODECYL METHACRYLATE) WITH CETYLTRIMETHYL AMMONIUM BROMIDE IN AQUEOUS SOLUTION

    Institute of Scientific and Technical Information of China (English)

    Cong-hua Lu; Chuan-qiou Luo; Wei-xiao Cao

    2003-01-01

    The interaction of poly(sodium sulfodecyl methacrylate) (PSSM) with cetyltrimethyl ammonium bromide (CTAB)was studied. It was found that the precipitate formed from PSSM and CTAB will be dissolved by excessive CTAB, resultingin the appearance of two maxima of the solution viscosity at the molar ratio (CTAB/-SO3-) of ≈ 0.68 and ≈ 1.30,respectively. The first one is related closely to the aggregation of polymer chains via CTAB molecules and the second oneshould be ascribed to the formation of the mixed micelles comprising surfactant and the polymer's hydrophobic chains. Theeffect of NaCl on the viscosity, the transmittance of the aqueous solution and the solubility of oil-soluble dye (dimethylyellow) in the mixed system were also investigated.

  18. Aqueous DMSO Mediated Conversion of (2-(Arylsulfonyl)vinyl)iodonium Salts to Aldehydes and Vinyl Chlorides.

    Science.gov (United States)

    Zawia, Eman; Moran, Wesley J

    2016-01-01

    Vinyl(aryl)iodonium salts are useful compounds in organic synthesis but they are under-utilized and their chemistry is under-developed. Herein is described the solvolysis of some vinyl(phenyl)iodonium salts, bearing an arylsulfonyl group, in aqueous DMSO leading to aldehyde formation. This unusual process is selective and operates under ambient conditions. Furthermore, the addition of aqueous HCl and DMSO to these vinyl(aryl)iodonium salts allows their facile conversion to vinyl chlorides. PMID:27537866

  19. Aqueous chloride stress corrosion cracking of titanium: A comparison with environmental hydrogen embrittlement

    Science.gov (United States)

    Nelson, H. G.

    1973-01-01

    The physical characteristics of stress corrosion cracking of titanium in an aqueous chloride environment are compared with those of embrittlement of titanium by a gaseous hydrogen environment in an effort to help contribute to the understanding of the possible role of hydrogen in the complex stress corrosion cracking process. Based on previous studies, the two forms of embrittlement are shown to be similar at low hydrogen pressures (100 N/sqm) but dissimilar at higher hydrogen pressures. In an effort to quantify this comparison, tests were conducted in an aqueous chloride solution using the same material and test techniques as had previously been employed in a gaseous hydrogen environment. The results of these tests strongly support models based on hydrogen as the embrittling species in an aqueous chloride environment. Further, it is shown that if hydrogen is the causal species, the effective hydrogen fugacity at the surface of titanium exposed to an aqueous chloride environment is equivalent to a molecular hydrogen pressure of approximately 10 N/sqm.

  20. 转化法制备氯化铵的条件优化%Optimization of Conditions for Preparation of Ammonium Chloride Based Transformation Method

    Institute of Scientific and Technical Information of China (English)

    周德望; 郭必豹; 李祖略; 李芳

    2015-01-01

    以氯化钠和硫酸铵为原料,采用正交设计法对氯化铵的制备条件进行了优化。实验结果表明:在物料比为21,冰浴冷却时间为20 min,蒸发水量为45%,冷却温度为35℃的条件下,单次结晶氯化铵的产率和纯度明显提高。%An experimental program was designed for preparing ammonium chloride from sodium chloride and ammonium sulfate based on the orthogonal design. The optimum conditions were determined as follows: material ratio 2:1, cooling time 20 min and temperature 35 ℃,water evaporation 45%. Under above conditions, the productivity and pure of ammonium chloride could be improved dramatically.

  1. Removal of ammonium ion from aqueous solution by natural Turkish (Yildizeli) zeolite for environmental quality

    International Nuclear Information System (INIS)

    The purposes of this study were to investigate the removal efficiency of ammonium (NH4+) ion from aqueous solution using the natural Turkish (Yildizeli) zeolite and to characterize equilibrium isotherms. Experiments were carried out using batch method as a function of the solution pH, shaking time, dosage of adsorbent, and temperature. All these factors affected NH4+ ion removal from aqueous solution. Equilibrium modelling data were fitted to linear Langmuir and Freundlich models. Dubinin-Redushckevich (D-R) isotherm was applied to describe the nature of ion exchange of NH4+ and found that it occurred physically. Thermodynamics parameters such as change in free energy (ΔGo), enthalpy (ΔHo) and entropy (ΔSo) were also calculated. These parameters confirmed that ion exchange of NH4+ by the zeolite was feasible, spontaneous and exothermic in nature. Based on the results, it can be concluded that the natural Turkish (Yildizeli) zeolite is suitable for the removal of NH4+ ions in wastewater treatments and agricultural purposes to in terms of sustainability of environmental quality

  2. Removal of ammonium ion from aqueous solution by natural Turkish (Yildizeli) zeolite for environmental quality

    Energy Technology Data Exchange (ETDEWEB)

    Saltali, Kadir [Department of Soil Science, Faculty of Agriculture, University of Gaziosmanpasa, 60240 Tokat (Turkey)]. E-mail: kadirs@gop.edu.tr; Sari, Ahmet [Department of Chemistry, Faculty of Art and Science, University of Gaziosmanpasa, 60240 Tokat (Turkey); Aydin, Mehmet [Graduate School of Natural and Applied Sciences, University of Gaziosmanpasa, 60240 Tokat (Turkey)

    2007-03-06

    The purposes of this study were to investigate the removal efficiency of ammonium (NH{sub 4} {sup +}) ion from aqueous solution using the natural Turkish (Yildizeli) zeolite and to characterize equilibrium isotherms. Experiments were carried out using batch method as a function of the solution pH, shaking time, dosage of adsorbent, and temperature. All these factors affected NH{sub 4} {sup +} ion removal from aqueous solution. Equilibrium modelling data were fitted to linear Langmuir and Freundlich models. Dubinin-Redushckevich (D-R) isotherm was applied to describe the nature of ion exchange of NH{sub 4} {sup +} and found that it occurred physically. Thermodynamics parameters such as change in free energy ({delta}G{sup o}), enthalpy ({delta}H{sup o}) and entropy ({delta}S{sup o}) were also calculated. These parameters confirmed that ion exchange of NH{sub 4} {sup +} by the zeolite was feasible, spontaneous and exothermic in nature. Based on the results, it can be concluded that the natural Turkish (Yildizeli) zeolite is suitable for the removal of NH{sub 4} {sup +} ions in wastewater treatments and agricultural purposes to in terms of sustainability of environmental quality.

  3. Enthalpic interactions of N-glycylglycine with xylitol in aqueous sodium chloride and potassium chloride solutions at T = 298.15 K

    International Nuclear Information System (INIS)

    The mixing enthalpies of N-glycylglycine with xylitol and their respective enthalpies of dilution in aqueous sodium chloride and potassium chloride solutions have been determined by using flow-mix isothermal microcalorimetry at the temperature of 298.15 K. These experimental results have been used to determine the heterotactic enthalpic interaction coefficients (hxy, hxxy, and hxyy) according to the McMillan-Mayer theory. It has been found that the heterotactic enthalpic pairwise interaction coefficients hxy between N-glycylglycine and xylitol in aqueous sodium chloride and potassium chloride solutions are negative and become less negative with an increase in the molality of sodium chloride or potassium chloride. The results are discussed in terms of solute-solute and solute-solvent interactions.

  4. Enthalpic interactions of N-glycylglycine with xylitol in aqueous sodium chloride and potassium chloride solutions at T = 298.15 K

    Energy Technology Data Exchange (ETDEWEB)

    Liu Min, E-mail: panpanliumin@163.co [College of Chemistry and Chemical Engineering, Liao Cheng University, Liaocheng, Shandong 252059 (China); Wang Lili [College of Chemistry and Chemical Engineering, Liao Cheng University, Liaocheng, Shandong 252059 (China); Zhu Lanying [College of Life Science and Bioengineering, Liao Cheng University, Liaocheng, Shandong 252059 (China); Li Hui; Sun Dezhi; Di Youying; Li Linwei [College of Chemistry and Chemical Engineering, Liao Cheng University, Liaocheng, Shandong 252059 (China)

    2010-07-15

    The mixing enthalpies of N-glycylglycine with xylitol and their respective enthalpies of dilution in aqueous sodium chloride and potassium chloride solutions have been determined by using flow-mix isothermal microcalorimetry at the temperature of 298.15 K. These experimental results have been used to determine the heterotactic enthalpic interaction coefficients (h{sub xy}, h{sub xxy}, and h{sub xyy}) according to the McMillan-Mayer theory. It has been found that the heterotactic enthalpic pairwise interaction coefficients h{sub xy} between N-glycylglycine and xylitol in aqueous sodium chloride and potassium chloride solutions are negative and become less negative with an increase in the molality of sodium chloride or potassium chloride. The results are discussed in terms of solute-solute and solute-solvent interactions.

  5. Ethyl­enedi­ammonium chloride thio­cyanate

    OpenAIRE

    Karoui, Sahel; Kamoun, Slaheddine; Michaud, François

    2013-01-01

    In the ethyl­enedi­ammonium dication of the title salt, C2H10N2 2+·Cl−·SCN−, the N—C—C—N torsion angle is 72.09 (12)°. In the crystal, an extensive three-dimensional hydrogen-bonding network, formed by N—H⋯Cl and N—H⋯N hydrogen bonds, holds all the ions together.

  6. Ammonium removal from high-strength aqueous solutions by Australian zeolite.

    Science.gov (United States)

    Wijesinghe, D Thushari N; Dassanayake, Kithsiri B; Sommer, Sven G; Jayasinghe, Guttila Y; J Scales, Peter; Chen, Deli

    2016-07-01

    Removal of ammonium nitrogen (NH4(+)-N) particularly from sources which are highly rich in nitrogen is important for addressing environmental pollution. Zeolites, aluminosilicate minerals, are commonly used as commercial adsorbents and ion-exchange medium in number of commercial applications due to its high adsorption capacity of ammonium (NH4(+)). However, detailed investigations on NH4(+) adsorption and ion exchange capacities of Australian natural zeolites are rare, particularly under higher NH4(+) concentrations in the medium. Therefore, this study was conducted to determine NH4(+) adsorption characteristics of Australian natural zeolites at high NH4(+) concentrations with and without other chemical compounds in an aqueous solution. Results showed that initial NH4(+) concentration, temperature, reaction time, and pH of the solution had significant effects on NH4(+) adsorption capacity of zeolite. Increased retention time and temperature generally had a positive impact on adsorption. Freundlich model fitted well with adsorption process of Australian natural zeolites; however, Langmuir model had best fitted for the adsorption process of sodium (Na(+)) treated zeolites. NaCl treatment increased the NH4(+) adsorption capacity of Australian zeolites by 25% at 1000 mg-N, NH4(+) solution. The maximum adsorption capacity of both natural Australian zeolites and Na(+) treated zeolites were estimated as 9.48 and 11.83 mg-N/g, respectively, which is lower than many zeolites from other sources. Compared to the NH4(+) only medium, presence of other competitive ions and acetic acid in the medium (resembling composition in digested swine manure slurries) reduced NH4(+) removal of natural and Na(+) treated zeolites by 44% and 57%, respectively. This suggests detailed investigations are required to determine practically achievable NH4(+) -N removal potential of zeolites for applications in complex mediums such as animal manure slurries. PMID:27050255

  7. Ammonium removal from high-strength aqueous solutions by Australian zeolite.

    Science.gov (United States)

    Wijesinghe, D Thushari N; Dassanayake, Kithsiri B; Sommer, Sven G; Jayasinghe, Guttila Y; J Scales, Peter; Chen, Deli

    2016-07-01

    Removal of ammonium nitrogen (NH4(+)-N) particularly from sources which are highly rich in nitrogen is important for addressing environmental pollution. Zeolites, aluminosilicate minerals, are commonly used as commercial adsorbents and ion-exchange medium in number of commercial applications due to its high adsorption capacity of ammonium (NH4(+)). However, detailed investigations on NH4(+) adsorption and ion exchange capacities of Australian natural zeolites are rare, particularly under higher NH4(+) concentrations in the medium. Therefore, this study was conducted to determine NH4(+) adsorption characteristics of Australian natural zeolites at high NH4(+) concentrations with and without other chemical compounds in an aqueous solution. Results showed that initial NH4(+) concentration, temperature, reaction time, and pH of the solution had significant effects on NH4(+) adsorption capacity of zeolite. Increased retention time and temperature generally had a positive impact on adsorption. Freundlich model fitted well with adsorption process of Australian natural zeolites; however, Langmuir model had best fitted for the adsorption process of sodium (Na(+)) treated zeolites. NaCl treatment increased the NH4(+) adsorption capacity of Australian zeolites by 25% at 1000 mg-N, NH4(+) solution. The maximum adsorption capacity of both natural Australian zeolites and Na(+) treated zeolites were estimated as 9.48 and 11.83 mg-N/g, respectively, which is lower than many zeolites from other sources. Compared to the NH4(+) only medium, presence of other competitive ions and acetic acid in the medium (resembling composition in digested swine manure slurries) reduced NH4(+) removal of natural and Na(+) treated zeolites by 44% and 57%, respectively. This suggests detailed investigations are required to determine practically achievable NH4(+) -N removal potential of zeolites for applications in complex mediums such as animal manure slurries.

  8. AN EFFECTIVE METHOD TO IMPROVE THE WET STRENGTH OF POLY(DIALLYLDIMETHYL-AMMONIUM CHLORIDE) HYDROGELS

    Institute of Scientific and Technical Information of China (English)

    Jing Ren; Hong-fei Ha

    2002-01-01

    New IPN hydrogels composed of diallyldimethylammonium chloride (DADMAC) and natural macromolecule,kappa-carrageenan (KC) were prepared by gamma irradiation and their properties were studied. The results show that both the gel strength and the swelling capacity of the IPN hydrogels were enhanced significantly as compared with those of the pure hydrogels of PDADMAC.

  9. Restraining Na-Montmorillonite Delamination in Water by Adsorption of Sodium Dodecyl Sulfate or Octadecyl Trimethyl Ammonium Chloride on the Edges

    Directory of Open Access Journals (Sweden)

    Hongliang Li

    2016-08-01

    Full Text Available The delamination of montmorillonite in water leads to sliming in ore slurry, which is detrimental to mineral flotation and solid/water separation. In this work, the delamination of Na-montmorillonite (Na-MMT has been restrained by sodium dodecyl sulfate (SDS or octadecyl trimethyl ammonium chloride (1831 through the adsorption on the edge of the mineral. The experimental results have shown that the pretreatment by adding SDS and 1831 could greatly reduce the Stokes size percentage of −1.1 µm particles in the aqueous Na-MMT suspension. From the X-ray diffractometer (XRD results, the interlayer spacing of the MMT pre-treated by SDS and 1831 is smaller than that of original MMT particles. Adsorption position of SDS and 1831 on MMT surfaces was analyzed by the measurements of adsorption capacity of SDS and 1831, inductively-coupled plasma spectra, and zeta potential before and after the plane surface of MMT was covered with tetraethylenepentaminecopper ([Cu(tetren]2+. The results indicated that SDS and 1831 are adsorbed on the edge and the whole surface of Na-MMT, respectively. Delamination of MMT could be well restrained by the adsorption of SDS and 1831 on the edges of MMT.

  10. BER OPTIC SENSOR MODIFIED BY GRAFTING OF THE MOLECULARLY IMPRINTED POLYMER FOR THE DETECTION OF AMMONIUM IN AQUEOUS MEDIA

    Directory of Open Access Journals (Sweden)

    N. Lopes,

    2015-07-01

    Full Text Available Subject of Research.The paper deals with novel chemical sensors based on the polymeric optical fibers modified by grafting of the molecularly imprinted polymer for the detection of ammonium in aqueous solutions. Elevated concentrations of ammonium in surface waters lead to their eutrophication, that’s why, monitoring of the content of this ion is very important for the evaluation of surface water quality. However, currently in situ monitoring of relevant parameters in surface waters is constrained by the availability and cost of commercial sensors. Attractive approach to the development of chemical sensors for remote controls is the use of polymeric optical fibers. Polymer optical fibers have high mechanical resistance and low cost, and give the possibility for multiplexing and remote sensing. Method. Polymeric layer imprinted with ammonium ions was grafted on the surface of the methylmethacrylate fiber. Methacrylic acid was used as a monomer, ethylene glycol dimethacylate as a cross-linker, 2.2'-Azobis (2-ethylpropionamidine dihydrochloride as a radical initiator, ammonium as a template and water:ethanol 4:1 mixture as a solvent. Optimization of the imprinted polymer synthesis conditions was carried out using intensity of transmitted light, uniformity of the grafted polymeric layer and response in the aqueous ammonium solutions as optimization criteria. Main Results. Chemical sensors based on the polymeric optical fibers modified by grafting of the molecularly imprinted polymer for the detection of ammonium in aqueous solutions have been developed. New method of the grafting of the molecularly imprinted polymer on the surface of the methylmethacrylate optical fiber has been developed. It was found out, that high concentrations of the monomer and cross-linker in the polymerization solutions cause optical fiber damage while longer polymerization times result in the decrease of the intensity of transmitted light. Optical sensor demonstrating

  11. Extraction of Caprolactam from Aqueous Ammonium Sulfate Solution in Pulsed Packed Column Using 250Y Meliapak Packings

    Institute of Scientific and Technical Information of China (English)

    谢方友; 朱明乔; 等

    2002-01-01

    Liquid-lquid equilbrium(LLE)data of water-caprolactam-benzene-(NH4)2SO4 system at 303K were measured for extraction of caprolactam from aqueous ammonium sulfate solution.The influence of fluid flow rate,pulsation intensity on flooding velocity and mass transfer was studied for extraction of caprolactam from ammonium sulfate solution in a laboratory pulsed packed column.The flooding velocities and overall apparent heght of a transfer unit were given under various operation conditions.An industrial column developed based on above study is operated well.The scale-up effect is discussed.

  12. Stepwise aggregation of dimethyl-di-n-octylammonium chloride in aqueous solutions: from dimers to vesicles.

    Science.gov (United States)

    Leclercq, Loïc; Nardello-Rataj, Véronique; Turmine, Mireille; Azaroual, Nathalie; Aubry, Jean-Marie

    2010-02-01

    The self-aggregation of dimethyl-di-n-octylammonium chloride, in diluted aqueous solutions, was studied with various experimental and theoretical techniques: zetametry, conductimetry, dimethyl-di-n-octylammonium and chloride-selective electrodes, tensiometry, NMR spectroscopy ((1)H and DOSY), and molecular modeling (PM3 and molecular dynamic). The combination of the data obtained by these techniques led us to propose a stepwise aggregation process with increasing concentration: dimers (0.2-10 mM), bilayers (10-30 mM), and finally vesicles (>30 mM).

  13. Identification and Characterization of Visible Absorption Components in Aqueous Methylglyoxal-Ammonium Sulfate Mixtures

    Science.gov (United States)

    McGivern, W. S.; Allison, T. C.; Radney, J. G.; Zangmeister, C. D.

    2014-12-01

    The aqueous reaction of methylglyoxal (MG) with ammonium sulfate has been suggested as a source of atmospheric ``brown carbon.'' We have utilized high-performance liquid chromatography coupled to ultraviolet-visible spectroscopy and tandem mass spectrometry to study the products of this reaction at high concentrations. The overall product spectrum shows a large number of distinct components; however, the visible absorption from this mixture is derived a very small number of components. The largest contributor is an imine-substituted (C=N-H) product of aldol condensation/facile dehydration reaction between the parent MG and a hydrated product of the MG + ammonia reaction. The asymmetric nature of this compound relative to the aldol condensation of two MG results in a sufficiently large redshift of the UV absorption spectrum that absorption of visible radiation can occur in the long-wavelength tail. The simplicity of the imine products is a result of a strong bias toward ketimine products due to the extensive hydration of the aldehydic moiety in the parent in aqueous solution. In addition, a strong pH dependence of the absorption cross section was observed with significantly greater absorption under more basic conditions. We have performed time-dependent density functional theory calculations to evaluate the absorption spectra of all of the possible condensation products and their respective ions, and the results are consistent with the experimental observations. We have also observed smaller concentrations of other condensation products of the imine-substituted parent species that do not contribute significantly to the visible absorption but have not been previously discussed.

  14. Impact of Bicarbonate, Ammonium Chloride, and Acetazolamide on Hepatic and Renal SLC26A4 Expression

    OpenAIRE

    Alesutan, Ioana; Daryadel, Arezoo; Mohebbi, Nilufar; Pelzl, Lisann; Leibrock, Christina; Voelkl, Jakob; Bourgeois, Soline; Dossena, Silvia; Nofziger, Charity; Paulmichl, Markus; Carsten A Wagner; Lang, Florian

    2011-01-01

    SLC26A4 encodes pendrin, a transporter exchanging anions such as chloride, bicarbonate, and iodide. Loss of function mutations of SLC26A4 cause Pendred syndrome characterized by hearing loss and enlarged vestibular aqueducts as well as variable hypothyroidism and goiter. In the kidney, pendrin is expressed in the distal nephron and accomplishes HCO(3)(-) secretion and Cl(-) reabsorption. Renal pendrin expression is regulated by acid-base balance. The liver contributes to acid-base regulation ...

  15. Aqueous ammonium thiocyanate solutions as refractive index-matching fluids with low density and viscosity

    Science.gov (United States)

    Morrison, Benjamin C.; Borrero-Echeverry, Daniel

    2015-11-01

    Index-matching fluids play an important role in many fluid dynamics experiments, particularly those involving particle tracking, as they can be used to minimize errors due to distortion from the refraction of light across interfaces of the apparatus. Common index-matching fluids, such as sodium iodide solutions or mineral oils, often have densities or viscosities very different from those of water. This can make them undesirable for use as a working fluid when using commercially available tracer particles or at high Reynolds numbers. A solution of ammonium thiocyanate (NH4SCN) can be used for index-matching common materials such as borosilicate glass and acrylic, and has material properties similar to those of water (ν ~ 1 . 6 cSt and ρ ~ 1 . 1 g/cc). We present an empirical model for predicting the refractive index of aqueous NH4SCN solutions as a function of temperature and NH4SCN concentration that allows experimenters to develop refractive index matching solutions for various common materials. This work was supported by the National Science Foundation (CBET-0853691) and by the James Borders Physics Student Fellowship at Reed College.

  16. Application of Ozone Related Processes to Mineralize Tetramethyl Ammonium Hydroxide in Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Chyow-San Chiou

    2013-01-01

    Full Text Available Tetramethyl ammonium hydroxide (TMAH is an anisotropic etchant used in the wet etching process of the semiconductor industry and is hard to degrade by biotreatments when it exists in wastewater. This study evaluated the performance of a system combined with ultraviolet, magnetic catalyst (SiO2/Fe3O4 and O3, denoted as UV/O3, to TMAH in an aqueous solution. The mineralization efficiency of TMAH under various conditions follows the sequence: UV/O3 > UV/H2O2/O3 > H2O2/SiO2/Fe3O4/O3 > H2O2/O3 > SiO2/Fe3O4/O3 > O3 > UV/H2O2. The results suggest that UV/O3 process provides the best condition for the mineralization of TMAH (40 mg/L, resulting in 87.6% mineralization, at 60 min reaction time. Furthermore, the mineralization efficiency of SiO2/Fe3O4/H2O2/O3 was significantly higher than that of O3, H2O2/O3, and UV/H2O2. More than 90% of the magnetic catalyst was recovered and easily redispersed in a solution for reuse.

  17. Sorption of ammonium and phosphate from aqueous solution by biochar derived from phytoremediation plants

    Institute of Scientific and Technical Information of China (English)

    Zheng ZENG; Muhammad Tariq RAFIQ; Song-da ZHANG; Ting-qiang LI; Feng-liang ZHAO; Zhen-li HE; He-ping ZHAO; Xiao-e YANG; Hai-long WANG; Jing ZHAO

    2013-01-01

    The study on biochar derived from plant biomass for environmental applications is attracting more and more attention. Twelve sets of biochar were obtained by treating four phytoremediation plants, Salix rosthorni Seemen, Thalia dealbata, Vetiveria zizanioides, and Phragmites sp., sequential y through pyrolysis at 500 °C in a N2 environ-ment, and under different temperatures (500, 600, and 700 °C) in a CO2 environment. The cation exchange capacity and specific surface area of biochar varied with both plant species and pyrolysis temperature. The magnesium (Mg) content of biochar derived from T. dealbata (TC) was obviously higher than that of the other plant biochars. This bi-ochar also had the highest sorption capacity for phosphate and ammonium. In terms of biomass yields, adsorption capacity, and energy cost, T. dealbata biochar produced at 600 °C (TC600) is the most promising sorbent for removing contaminants (N and P) from aqueous solution. Therefore, T. dealbata appears to be the best candidate for phyto-remediation application as its biomass can make a good biochar for environmental cleaning.

  18. Molecular Modeling of Ammonium, Calcium, Sulfur, and Sodium Lignosulphonates in Acid and Basic Aqueous Environments

    Science.gov (United States)

    Salazar Valencia, P. J.; Bolívar Marinez, L. E.; Pérez Merchancano, S. T.

    2015-12-01

    Lignosulphonates (LS), also known as lignin sulfonates or sulfite lignin, are lignins in sulfonated forms, obtained from the "sulfite liquors," a residue of the wood pulp extraction process. Their main utility lies in its wide range of properties, they can be used as additives, dispersants, binders, fluxing, binder agents, etc. in fields ranging from food to fertilizer manufacture and even as agents in the preparation of ion exchange membranes. Since they can be manufactured relatively easy and quickly, and that its molecular size can be manipulated to obtain fragments of very low molecular weight, they are used as transport agents in the food industry, cosmetics, pharmaceutical and drug development, and as molecular elements for the treatment of health problems. In this paper, we study the electronic structural and optical characteristics of LS incorporating ammonium, sulfur, calcium, and sodium ions in acidic and basic aqueous media in order to gain a better understanding of their behavior and the very interesting properties exhibit. The studies were performed using the molecular modeling program HyperChem 5 using the semiempirical method PM3 of the NDO Family (neglect of differential overlap), to calculate the structural properties. We calculated the electronic and optical properties using the semiempirical method ZINDO / CI.

  19. Effect of polyester blends in hydroentangled raw and bleached cotton nonwoven fabrics on the adsorption of alkyl-dimethyl-benzyl-ammonium chloride

    Science.gov (United States)

    The adsorption kinetics and isotherms of alkyl-dimethyl-benzyl-ammonium chloride (ADBAC), a cationic surfactant commonly employed as an antimicrobial agent, on hydroentangled nonwoven fabrics (applicable for wipes) including raw cotton, bleached cotton, and their blends with polyester (PES) were stu...

  20. Determination of standard enthalpies of formation and lattice energies of ammonium chloride and ammonium sulfate%氯化铵和硫酸铵生成焓与晶格能测定

    Institute of Scientific and Technical Information of China (English)

    杨春; 成文玉; 王庆伦; 刘晓莉; 王桂香; 杨津

    2013-01-01

    A new inorganic chemistry experiment of “Determination of standard enthalpies of formation and lattice energies of ammonium chloride and ammonium sulfate” has been designed . To reduce the measurement error , temperature was measured by digital Beckman thermometer and the experimental data were passed to computer for drawing and linear regress by means of software Origin . As a result , the mass of ammonium chloride used for measurement of enthalpy of dissolution decreased to about 40% .The designing experiment on ammonium sulfate can cultivate the integrated ability of students .Calculations of the lattice energies of ammonium chloride and ammonium sulfate based on their enthalpies of dissolution are introduced ,which can guide the students to research the relationship between the ionic crystal structures and physicochemical properties .%设计改进了一个新的无机化学实验“氯化铵和硫酸铵生成焓与晶格能的测定”。用数字贝克曼温度计代替水银温度计以减小测量的误差;用作图法对温度-时间曲线进行校正,提高了温度测量的准确度;在测定N H4 C1溶解焓的实验中使N H4 C1的用量减少为原来的40%,硫酸铵的设计性实验可以培养学生的综合能力,所得硫酸铵溶液可用作制备硫酸亚铁铵的原料;通过溶解热求晶格能,引导学生探究离子晶体结构与物性间的关系。

  1. Chemical treatment of aqueous radioactive Cesium-137 waste using Ferri Chloride

    International Nuclear Information System (INIS)

    Ferric Chloride 6H2O was used for treatment of liquid radioactive wastes containing Cesium-137. Various concentration of ferric chloride 6H2O have been added into the waste at different pH and speed of stirrer. The treatment was based on the coagulans-flocculation and coprecipitation mechanisms. The best result of this experiment was achieved by adding 300 ppm of Ferric chloride 6 H2O into liquid waste on following condition the rate Stirrer was 250 rpm. At this condition, it was found that the separation efficiency and the decontamination factor were 83.32 % and 5.99. The activity of decreasing of aqueous radioactive Cesium-137 waste was 2.10 x 10-4 Ci/l to 3.50 x 10-5 Ci/l

  2. Direct hydride derivatization of methyl- and ethylmercury chlorides in aqueous solution with KBH4

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A convenient hydride derivatization procedure of methyl-and ethylmercury chlorides to volatile hydrides was reported. In sealed vials methylmercury and ethylmercury compounds in acidic aqueous solutions were converted into their volatile forms by the reaction with potassium tetrahydroborate(KBH4) and elvolved to the headspace of the vials. The gaseous analytes in the headspace were extracted and concentrated by solid phase microextraction(SPME) and injected into gas chromatography (GC) for separation and identified by mass selective detector(MS).

  3. Pressure-induced unfolding of lysozyme in aqueous guanidinium chloride solution

    OpenAIRE

    Sasahara, K; Nitta, K

    1999-01-01

    The pressure-induced unfolding of lysozyme was investigated in an aqueous guanidinium chloride solution by means of ultraviolet spectroscopy. Assuming a two-state transition model, volume changes were calculated from the slope of free energy vs. pressure plots over a temperature range of 10 to 60 degrees C. Between 25 and 60 degrees C, almost constant volume changes were observed in the transition region, which was reflected in almost identical slopes of the free energy change vs. pressure pl...

  4. Pressure-induced unfolding of lysozyme in aqueous guanidinium chloride solution.

    OpenAIRE

    Sasahara, K; Nitta, K

    1999-01-01

    The pressure-induced unfolding of lysozyme was investigated in an aqueous guanidinium chloride solution by means of ultraviolet spectroscopy. Assuming a two-state transition model, volume changes were calculated from the slope of free energy vs. pressure plots over a temperature range of 10 to 60 degrees C. Between 25 and 60 degrees C, almost constant volume changes were observed in the transition region, which was reflected in almost identical slopes of the free energy change vs. pressure pl...

  5. Separation of chloride and sulfate ions in univalent and divalent cation forms from aqueous streams.

    Science.gov (United States)

    Bader, M S

    2000-04-28

    The precipitation and separation of chloride and sulfate in several cation forms (sodium, potassium, magnesium, calcium, strontium, and barium) from aqueous streams were studied using isopropylamine (IPA) and ethylamine (EA) as precipitation solvents. The precipitation fractions (P) of the tested chloride salts at 5000 and 10,000 ppm by both IPA and EA over the studied range of solvents volume ratio (V(R)) were relatively identical (18-60%) and their small variations were within their experimental uncertainty. The P of combined sulfate at 1000 ppm (56-99.5%) and chloride at 5000 ppm (28-62%) in the form of calcium by IPA over the studied range of V(R) were appreciably higher than the P of sulfate (10-98.5%) from calcium sulfate in the absence of calcium chloride, or the P of chloride (18-58%) from calcium chloride in the absence of calcium sulfate. The P of chloride from oil-field-produced waters at 106,654 ppm (20-88%) by both IPA and EA were higher than the P of chloride from diluted produced water at 20,000 (17-68%) and 10,000 ppm (16-65%) over the studied range of V(R). The small amounts of sulfate present in the produced waters (e.g., 435 ppm) were completely removed at V(R) of 0.1 (the first stage of precipitation). Consistency tests performed on the acquired data indicated a good level of experimental consistency. Two model equations (2-Suffix and 3-Suffix) derived from thermodynamic principles of solid-liquid equilibrium (SLE) criteria were employed to correlate the acquired data. While both equations were adequate for correlating the precipitation data, the 3-Suffix equation was more accurate.

  6. Bi(TFA3 and Bi(OTf3 Catalyzed Conversions of Epoxides to Thiiranes with Ammonium Thiocyanate and Thiourea under Non-Aqueous Conditions

    Directory of Open Access Journals (Sweden)

    Ahmad R. Khosropour

    2001-11-01

    Full Text Available Various epoxides are converted to their corresponding thiiranes in excellent yields with ammonium thiocyanate and thiourea under non-aqueous conditions in the presence of catalytic amounts of Bi(TFA3 and Bi(OTf3.

  7. Bi(TFA)3 and Bi(OTf)3 Catalyzed Conversions of Epoxides to Thiiranes with Ammonium Thiocyanate and Thiourea under Non-Aqueous Conditions

    OpenAIRE

    Khosropour, Ahmad R.; Iraj Mohammadpoor-Baltork

    2001-01-01

    Various epoxides are converted to their corresponding thiiranes in excellent yields with ammonium thiocyanate and thiourea under non-aqueous conditions in the presence of catalytic amounts of Bi(TFA)3 and Bi(OTf)3.

  8. Coacervation and aggregate transitions of a cationic ammonium gemini surfactant with sodium benzoate in aqueous solution.

    Science.gov (United States)

    Wang, Ruijuan; Tian, Maozhang; Wang, Yilin

    2014-03-21

    Coacervation in an aqueous solution of cationic ammonium gemini surfactant hexamethylene-1,6-bis(dodecyldimethylammonium bromide) (C12C6C12Br2) with sodium benzoate (NaBz) has been investigated at 25 °C by turbidity titration, light microscopy, dynamic light scattering, cryogenic temperature transmission electron microscopy (Cryo-TEM), scanning electron microscopy (SEM), isothermal titration calorimetry, ζ potential and (1)H NMR measurements. There is a critical NaBz concentration of 0.10 M, only above which coacervation can take place. However, if the NaBz concentration is too large, coacervation also becomes difficult. Coacervation takes place at a very low concentration of C12C6C12Br2 and exists in a very wide concentration region of C12C6C12Br2. The phase behavior in the NaBz concentration from 0.15 to 0.50 M includes spherical micelles, threadlike micelles, coacervation, and precipitation. With increasing NaBz concentration, the phase boundaries of coacervation shift to higher C12C6C12Br2 concentration. Moreover, the C12C6C12Br2-NaBz aggregates in the coacervate are found to be close to charge neutralized. The Cryo-TEM and SEM images of the coacervate shows a layer-layer stacking structure consisting of a three-dimensional network formed by the assembly of threadlike micelles. Long, dense and almost uncharged threadlike micelles are the precursors of coacervation in the system. PMID:24651935

  9. Removal of ammonium chloride generated by ammonia slip from the SNCR process in municipal solid waste incinerators.

    Science.gov (United States)

    Hwang, In-Hee; Minoya, Hiroshi; Matsuto, Toshihiko; Matsuo, Takayuki; Matsumoto, Akihiro; Sameshima, Ryoji

    2009-03-01

    The selective non-catalytic reduction (SNCR) process is one of the methods used to reduce NO(x) to N(2) and H(2)O by injecting NH(3) or urea solution into a high-temperature furnace. Merits of this method include simple handling, low cost, and energy savings. However, a critical problem of the SNCR process is the generation of ammonia slip; in reactions with HCl in flue gas, ammonium chloride is generated and forms detached white plumes near the stack. Using a laboratory-scale experimental apparatus, we examined the possibility of NH(4)Cl collection and removal by a bag filter (BF). The molar NH(3)/HCl ratio of the compound collected at the filter was nearly one, regardless of gas temperature, retention time, and concentration, confirming the formation of NH(4)Cl. The NH(4)Cl generation ratio increased as reaction temperature decreased, indicating that the collection efficiency of NH(4)Cl should increase if the BF is operated at the lowest possible temperature while avoiding the critical point causing low-temperature corrosion (e.g., 150 degrees C). In addition, the use of activated carbon injection in the front of the BF and the dust layer on the BF are expected to capture slipped ammonia at the BF and reduce NH(4)Cl fume generation in the stack.

  10. Methacryloxylethyl Cetyl Ammonium Chloride Induces DNA Damage and Apoptosis in Human Dental Pulp Cells via Generation of Oxidative Stress.

    Science.gov (United States)

    Jiao, Yang; Ma, Sai; Wang, Yirong; Li, Jing; Shan, Lequn; Sun, Jinlong; Chen, Jihua

    2016-01-01

    The polymerizable antibacterial monomer methacryloxylethyl cetyl ammonium chloride (DMAE-CB) has provided an effective strategy to combat dental caries. However, the application of such material raises the question about the biological safety and the question remains open. The mechanism of this toxic action, however, is not yet clearly understood. The present study aims at providing novel insight into the possible causal link between cellular oxidative stress and DNA damage, as well as apoptosis in human dental pulp cells exposed to DMAE-CB. The enhanced formation of reactive oxygen species and depletion of glutathione, as well as differential changes in activities of superoxide dismutase, glutathione peroxidase, and catalase in DMAE-CB-treated cells indicated oxidative stress. By using substances that can alter GSH synthesis, we found that GSH was the key component in the regulation of cell response towards oxidative stress induced by DMAE-CB. The increase in oxidative stress-sensitive 8-Oxo-2'-deoxyguanosine (8-OHdG) content, formation of γ-H2AX and cell cycle G1 phase arrest indicated that DNA damage occurred as a result of the interaction between DNA base and ROS beyond the capacities of antioxidant mechanisms in cells exposed to DMAE-CB. Such oxidative DNA damage thus triggers the activation of ataxia telangiectasia-mutated (ATM) signaling, the intrinsic apoptotic pathway, and destruction of mitochondrial morphology and function. PMID:27143955

  11. Crystal structure of tetra­ethyl­ammonium chloride 3,4,5,6-tetra­fluoro-1,2-di­iodo­benzene

    OpenAIRE

    Viger-Gravel, Jasmine; Korobkov, Ilia; Bryce, David L.

    2015-01-01

    Equimolar qu­anti­ties of tetra­ethyl­ammonium chloride (Et4NCl) and 3,4,5,6-tetra­fluoro-1,2-di­iodo­benzene (o-DITFB or o-C6F4I2) have been co-crystallized in a solution of di­chloro­methane yielding a pure halogen-bonded compound, 3,4,5,6-tetra­fluoro-1,2-di­iodo­benzene–tetra­ethyl ammonium chloride (2/1), Et4N+·Cl−·2C6F4I2, in the form of translucent needles. [(Et4NCl)(o-C6F4I2)2] packs in the C2/c space group. The asymmetric unit includes one mol­ecule of DITFB, one Et4N+ cation located...

  12. Photochemical oxidation of chloride ion by ozone in acid aqueous solution.

    Science.gov (United States)

    Levanov, Alexander V; Isaykina, Oksana Ya; Amirova, Nazrin K; Antipenko, Ewald E; Lunin, Valerii V

    2015-11-01

    The experimental investigation of chloride ion oxidation under the action of ozone and ultraviolet radiation with wavelength 254 nm in the bulk of acid aqueous solution at pH 0-2 has been performed. Processes of chloride oxidation in these conditions are the same as the chemical reactions in the system O3 - OH - Cl(-)(aq). Despite its importance in the environment and for ozone-based water treatment, this reaction system has not been previously investigated in the bulk solution. The end products are chlorate ion ClO3(-) and molecular chlorine Cl2. The ions of trivalent iron have been shown to be catalysts of Cl(-) oxidation. The dependencies of the products formation rates on the concentrations of O3 and H(+) have been studied. The chemical mechanism of Cl(-) oxidation and Cl2 emission and ClO3(-) formation has been proposed. According to the mechanism, the dominant primary process of chloride oxidation represents the complex interaction with hydroxyl radical OH with the formation of Cl2(-) anion-radical intermediate. OH radical is generated on ozone photolysis in aqueous solution. The key subsequent processes are the reactions Cl2(-) + O3 → ClO + O2 + Cl(-) and ClO + H2O2 → HOCl + HO2. Until the present time, they have not been taken into consideration on mechanistic description and modelling of Cl(-) oxidation. The final products are formed via the reactions 2ClO → Cl2O2, Cl2O2 + H2O → 2H(+) + Cl(-) + ClO3(-) and HOCl + H(+) + Cl(-) ⇄ H2O + Cl2. Some portion of chloride is oxidized directly by O3 molecule with the formation of molecular chlorine in the end.

  13. Partition of Chiral pharmaceutical intermediate R(-)-Mandelic Acid in Aqueous Two-Phase System of Poly(ethylene glycol)-Ammonium Sulfate

    Institute of Scientific and Technical Information of China (English)

    Xu Xiaoping; Li Zhongqin; Chen Jiebo; Huang Xinghua

    2004-01-01

    An aqueous two-phase system of poly (ethylene glycol)-ammonium sulfate was employed to separate R (-)-mandelic acid.The result showed that R (-)-mandelic acid has priority to partition in PEG-rich top phase. This indicated that aqueous two-phase is a very suitable system for separation of R(-)-mandelic acid.

  14. Extraction of Palladium (Ⅱ) with p-Methylphenylalkylsulfide from Aqueous Chloride Media

    Institute of Scientific and Technical Information of China (English)

    杨立; 章正熙; 刘旭辉; 郭亚莉; 二井晋; 竹内宽

    2005-01-01

    p-Methylphenylalkylsulfide of various alkyl chain length as extractant were synthesized and the extraction of palladium was examined in terms of equilibrium and kinetics. Distribution ratio of Pd was independent of alkyl chain length. For aqueous chloride media, there was a significant difference in distribution ratios for the solution of NaC1 and HC1. The results of loading test and the slope analysis suggest that the extractant and Pd (Ⅱ) form 2:1 complex. Furthermore, the extraction rate based on the volume of aqueous phase was obtained in a stirred vessel, and the rate equation was presented. Unfortunately, it was difficult to construct surfactant liquid membrane system by use of the present extractant.

  15. Effect of Electrochemical Treatment in Aqueous Ammonium Bicarbonate on Surface Properties of PAN-based Carbon Fibers

    Institute of Scientific and Technical Information of China (English)

    曹海琳; 黄玉东; 张志谦; 孙举涛

    2004-01-01

    The surface properties of PAN-based carbon fibers electrochemically treated in aqueous ammonium bicarbonate before and after treatment were characterized by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and Dynamic Contact Angle Analysis (DCAA). The results of characterization indicated that the oxygen and nitrogen contents in carbon fiber surface were significantly increased by electrochemical treatment, and amide groups was introduced onto it, which was related with the electrolyte. The AFM photographs illustrated that the roughness of the fiber surface was also increased. The wettibality of the fibers was improved after treatment because the surface energy especially the polar part of it was increased.

  16. Reentrant condensation of lysozyme: Implications for studying dynamics of lysozyme in aqueous solutions of lithium chloride

    Energy Technology Data Exchange (ETDEWEB)

    Mamontov, Eugene [ORNL; O' Neill, Hugh Michael [ORNL

    2014-01-01

    Recent studies have outlined the use of eutectic solution of lithium chloride in water to study microscopic dynamics of lysozyme in an aqueous solvent that is remarkably similar to pure water in many respects, yet allows experiments over a wide temperature range without the solvent crystallization. The eutectic point in (H2O)R(LiCl) system corresponds to R 7.3, and it is of interest to investigate whether less concentrated aqueous solutions of LiCl could be employed in low-temperature studies of a solvated protein. We have investigated a range of concentrations of lysozyme and LiCl in aqueous solutions to identify systems that do not show phase separation and avoid solvent crystallization on cooling down. Compared to the lysozyme concentration in solution, the concentration of LiCl in the aqueous solvent plays the major role in determining systems suitable for low-temperature studies. We have observed interesting and rich phase behavior reminiscent of reentrant condensation of proteins.

  17. Reentrant condensation of lysozyme: Implications for studying dynamics of lysozyme in aqueous solutions of lithium chloride.

    Science.gov (United States)

    Mamontov, Eugene; O'Neill, Hugh

    2014-06-01

    Recent studies have outlined the use of eutectic solutions of lithium chloride in water to study microscopic dynamics of lysozyme in an aqueous solvent that is remarkably similar to pure water in many respects, yet allows experiments over a wide temperature range without solvent crystallization. The eutectic point in a (H2O)R(LiCl) system corresponds to R ≈ 7.3, and it is of interest to investigate whether less-concentrated aqueous solutions of LiCl could be used in low-temperature studies of a solvated protein. We have investigated a range of concentrations of lysozyme and LiCl in aqueous solutions to identify systems that do not show phase separation and avoid solvent crystallization on cooling down. Compared to the lysozyme concentration in solution, the concentration of LiCl in the aqueous solvent plays the major role in determining systems suitable for low-temperature studies. We have observed interesting and rich phase behavior reminiscent of reentrant condensation of proteins. PMID:26819974

  18. Use of zeolitized coal fly ash in the simultaneous removal of ammonium and phosphate from aqueous solution

    Institute of Scientific and Technical Information of China (English)

    WU Deyi; HU Zhanbo; WANG Xinze; HE Shengbing; KONG Hainan

    2007-01-01

    Discharge of wastewater containing nitrogen and phosphate can cause cutrophication.Therefore,the development of an efficient material for the immobilization of the nutrients is important.In this study,a low calcium fly ash and high calcium fly ash were converted into zeolite using the hydrothermal method.The removal of ammonium and phosphate that coexist in aqueous solution by the synthesized zeolites were studied.The results showed that zeolitized fly ash could efficiently eliminate ammonium and phosphate at the same time.Saturation of zeolite with Ca2+ rather than Na+ favored the removal of both ammonium and Phosphate because the cation exchange reaction by the NH4+ resulted in the release of Ca2+ into the solution and precipitation of Ca2+ with POd43- followed.An increase in the temperature elevated the immobilization of phosphate whereas it abated the removal of ammonium.Nearly 60% removal efficiency for ammonium was achieved in the neutral pH range from 5.5 to 10.5.while the increase or decrease in pH out of the neutral range lowered the adsorption.In contrast,the removal of phosphate approached 100% at a pH lower than 5.0 or higher than 9.0,and less phosphate was immobilized at neutral pH.However,there was still a narrow pH range from 9.0 to 10.5 favoring the removal of both ammonium and phosphate.It was concluded that the removal of ammonium was caused by cation exchange;the contribution Of NH3 volatilization to immobilization at alkaline conditions(up to pH level of 11.4)was limited.with respect to phosphate immobilization,the mechanism was mainly the formation of precipitate as Ca3(PO4)2 within the basic pH range or as FePO4 and AlPO4 within acidic pH range.

  19. A chemical probe technique for the determination of reactive halogen species in aqueous solution: Part 2 – chloride solutions and mixed bromide/chloride solutions

    Directory of Open Access Journals (Sweden)

    C. Anastasio

    2006-02-01

    Full Text Available Although reactive halogen species (X*=X●, ●X2−, X2 and HOX, where X=Br, Cl, or I are important environmental oxidants, relatively little is known about their kinetics in condensed phases such as seawater and sea-salt particles. Here we describe a new technique to determine reactive chlorine and bromine species in aqueous solutions by using allyl alcohol (CH2=CHCH2OH as a chemical probe. This probe is combined with competition kinetics in order to determine steady state concentrations of X*(aq. In some cases the technique also can be used to determine the rates of formation and lifetimes of X* in aqueous solution. In a companion paper we reported the results of our method development for aqueous solutions containing only bromide (Br−. In this paper, we discuss method development for solutions containing chloride (Cl− alone, and for solutions containing both bromide and chloride.

  20. EQCM study of the electrodeposition of manganese in the presence of ammonium thiocyanate in chloride-based acidic solutions

    Energy Technology Data Exchange (ETDEWEB)

    Diaz-Arista, P. [Centro de Investigacion y Desarrollo Tecnologico en Electroquimica (CIDETEQ), Parque Tecnologico Sanfandila, Pedro Escobedo, Queretaro, A.P. 064, C.P. 76700, Queretaro (Mexico); Antano-Lopez, R. [Centro de Investigacion y Desarrollo Tecnologico en Electroquimica (CIDETEQ), Parque Tecnologico Sanfandila, Pedro Escobedo, Queretaro, A.P. 064, C.P. 76700, Queretaro (Mexico); Meas, Y. [Centro de Investigacion y Desarrollo Tecnologico en Electroquimica (CIDETEQ), Parque Tecnologico Sanfandila, Pedro Escobedo, Queretaro, A.P. 064, C.P. 76700, Queretaro (Mexico); Ortega, R. [Centro de Investigacion y Desarrollo Tecnologico en Electroquimica (CIDETEQ), Parque Tecnologico Sanfandila, Pedro Escobedo, Queretaro, A.P. 064, C.P. 76700, Queretaro (Mexico); Chainet, E. [LEPMI, ENSEEG, 1130, rue de la piscine, BP 45, 38402 Saint Martin d' Heres (France); Ozil, P. [LEPMI, ENSEEG, 1130, rue de la piscine, BP 45, 38402 Saint Martin d' Heres (France); Trejo, G. [Centro de Investigacion y Desarrollo Tecnologico en Electroquimica (CIDETEQ), Parque Tecnologico Sanfandila, Pedro Escobedo, Queretaro, A.P. 064, C.P. 76700, Queretaro (Mexico)]. E-mail: gtrejo@cideteq.mx

    2006-06-01

    The influence of ammonium thiocyanate (NH{sub 4}SCN) on the mechanism of manganese electrodeposition from a chloride-based acidic solution was investigated by cyclic voltammetry and electrochemical quartz crystal microbalance (EQCM). The EQCM data were represented as plots d{delta}m dt {sup -1} versus E, known as massograms. Because massograms are not affected by interference from the hydrogen evolution reaction, they clearly show the manganese reduction and oxidation processes. By comparing the voltammograms with their corresponding massograms, it was possible to differentiate mass changes due to faradaic processes from those due to non-faradaic processes. Morphology, chemical composition and structure of the manganese deposits formed in different potential ranges were analyzed by scanning electron microscopy (SEM), energy dispersion spectroscopy (EDS), and X-ray diffraction (XRD). The results showed that in the absence of NH{sub 4}SCN, Mn(OH){sub 2(s)} is formed in the potential range -1.1 to -0.9 V due to the hydrogen evolution reaction in this region. At more cathodic potentials, the deposition of {beta}-manganese and the inclusion of Mn(OH){sub 2(s)} into the deposit occur; both of these species underwent dissolution by non-faradaic processes during the anodic scan. In the presence of NH{sub 4}SCN, the formation of {alpha}- and {gamma}-manganese was observed. When the potential was {<=}-1.8 V and [NH{sub 4}SCN] exceeded 0.3 M, the {alpha}-manganese phase was favored.

  1. Aqueous Ammonia or Ammonium Hydroxide? Identifying a Base as Strong or Weak

    Science.gov (United States)

    Sanger, Michael J.; Danner, Matthew

    2010-01-01

    When grocery stores sell solutions of ammonia, they are labeled "ammonia"; however, when the same solution is purchased from chemical supply stores, they are labeled "ammonium hydroxide". The goal of this experiment is for students to determine which name is more appropriate. In this experiment, students use several different experimental methods…

  2. Leaching of lead from zinc leach residue in acidic calcium chloride aqueous solution

    Science.gov (United States)

    Wang, Le; Mu, Wen-ning; Shen, Hong-tao; Liu, Shao-ming; Zhai, Yu-chun

    2015-05-01

    A process with potentially reduced environmental impacts and occupational hazards of lead-bearing zinc plant residue was studied to achieve a higher recovery of lead via a cost-effective and environmentally friendly process. This paper describes an optimization study on the leaching of lead from zinc leach residue using acidic calcium chloride aqueous solution. Six main process conditions, i.e., the solution pH value, stirring rate, concentration of CaCl2 aqueous solution, liquid-to-solid (L/S) ratio, leaching temperature, and leaching time, were investigated. The microstructure and components of the residue and tailing were characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD). On the basis of experimental results, the optimum reaction conditions were determined to be a solution pH value of 1, a stirring rate of 500 r·min-1, a CaCl2 aqueous solution concentration of 400 g·L-1, a liquid-to-solid mass ratio of 7:1, a leaching temperature of 80°C, and a leaching time of 45 min. The leaching rate of lead under these conditions reached 93.79%, with an iron dissolution rate of 19.28%. Silica did not take part in the chemical reaction during the leaching process and was accumulated in the residue.

  3. Prediction of Swelling Behavior of N-Isopropylacrylamide Hydrogels in Aqueous Solution of Sodium Chloride

    Institute of Scientific and Technical Information of China (English)

    许小平; 李忠琴; 黄兴华; 王绪绪; 付贤; HiitherAndreas; MaurerGerd

    2004-01-01

    In this paper, a model is presented to correlate and predict the swelling behavior of hydrogels in aqueous solutions of electrolytes. The model is a combination of VERS-model, "phantom network" theory and "free-volume" contribution. The VERS-model is used to calculate Gibbs excess energy; "phantom network" theory to describe the elastic properties of polymer network, and "free-volume" contribution to account for additional difference in the size of the species. To test the model, a series of N-isopropylacrylamide based hydrogels are synthesized by free radical polymerization in oxygen-free, deionized water at 25~C under nitrogen atmosphere. Then, the degree of swelling of all investigated gels as well as the partition of the solute between the gel phase and the surrounding coexisting liquid phase are measured in aqueous solution of sodium chloride. The model test demonstrates that the swelling behavior correlated and predicted by the model agrees with the experimental data within the experimental uncertainty. The phase transition appeared in the experiment, and the influences of the total mass fraction of polymerizable materials ξgel as well as the mole fraction of the crosslinking agent YCR on the swelling behavior of IPAAm-gels can also be predicted correctly. All these show the potential of such model for correlation and prediction of the swelling behavior of hydrogels in aqueous solutions of electrolytes.

  4. Tailoring the optical properties of poly(diallyl dimethyl ammonium chloride) polyelectrolyte by incorporation of 2-mercaptoethanol capped CdSe nanoparticles

    Science.gov (United States)

    Tyagi, Chetna; Sharma, Ambika

    2016-10-01

    The present work deals with the preparation and characterization of 2-mercaptoethanol capped cadmium selenide (CdSe) nanoparticles, dispersed in poly(diallyl dimethyl ammonium chloride) (PDADMAC) polyelectrolyte aqueous solution. X-ray diffraction spectra, scanning electron microscopy and energy-dispersive x-ray have been used to determine the structure, particle size (d), surface morphology and composition of various constituents. The absorption spectra of pure PDADMAC and the CdSe/PDADMAC polymer nanocomposite (PNC) are analyzed to determine the values of the absorption coefficient (α) and energy band gap (E g) which are found to be 4 eV and 3.26 eV respectively. A red shift in the spectrum of the PNC, as compared to the pure polymer, has been observed. With the addition of CdSe nanoparticles in the PDADMAC polyelectrolyte, a remarkable change in the optical parameters of the pure polymer has been observed. The refractive index (n) obtained by using Swanepoel’s method decreases in the case of the PNC as compared to the pure polymer. The value of the static refractive index (n 0) is found to be 4.29 for the pure polymer and 1.52 for the PNC. The extinction coefficient, dielectric constants, optical conductivity and relaxation time have been evaluated. The Wemple–DiDomenico model has been used to evaluate the dispersion parameters such as the average energy gap (E 0) and dispersion energy (E d). The values of the nonlinear refractive index (n 2) of the pure polymer and PNC have been determined using the theoretical approaches suggested by Boling and Tichy and Ticha. n 2 increases in the case of PNC, which relates to the decreased energy band gap. Photoluminescence (PL) spectra have been studied to explore the energy band structure and interaction between CdSe nanoparticles and PDADMAC. The PL peaks obtained at 437 nm and 461 nm correspond to the pure polymer whereas the peak at 577 nm is attributed to CdSe.

  5. Aromatic quinoxaline as corrosion inhibitor for bronze in aqueous chloride solution

    Indian Academy of Sciences (India)

    N Saoudi; A Bellaouchou; A Guenbour; A Ben Bachir; E M Essassi; M El Achouri

    2010-06-01

    A new corrosion inhibitor, viz. 3-ethyl-6-méthyl-quinoxalin-2-one, 1-benzyl-6-methyl-quinoxalin- 2-one, 2-benzyloxy-3,6-dimethyl-quinoxaline, 1-benzyl-3-methyl-quinoxalin-2-one, were synthesized in the laboratory. Their influence on the inhibition on corrosion of bronze in aqueous chloride solution (3% NaCl) was studied by electrochemical polarization methods and weight-loss measurements. The impact of temperature on the effectiveness of the substances mentioned above has been determined between 20 and 60°C. The results showed that the corrosion resistance was greatly enhanced in the presence of inhibitor and that the effectiveness depends on some physicochemical properties of the molecule, related to its functional groups. These compounds act through the formation of a protective film on the surface of the alloy.

  6. Interfacial behavior of perchlorate versus chloride ions in saturated aqueous salt solutions

    Energy Technology Data Exchange (ETDEWEB)

    Ghosal, S; Kuo, I W; Baer, M D; Bluhm, H

    2009-04-14

    In recent years combination of theoretical and experimental work have presented a novel view of the aqueous interface wherein hard and/or multiply charged ions are excluded from the interface, but large polarizable anions show interfacial enhancement relative to the bulk. The observed trend in the propensity of anions to adsorb at the air/water interface appears to be reverse of the Hofmeister series for anions. This study focuses on experimental and theoretical examination of the partitioning behavior of perchlorate (ClO{sub 4}{sup -}) and chloride (Cl{sup -}) ions at the air/water interface. We have used ambient pressure X-ray photoelectron spectroscopy technique to directly probe the interfacial concentrations of ClO{sub 4}{sup -} and Cl{sup -} ions in sodium perchlorate and sodium chloride solutions, respectively. Experimental observations are compared with first principles molecular dynamics simulations. Both experimental and simulation results show enhancement of ClO{sub 4}{sup -} ion at the interface, compared with the absence of such enhancement in the case of Cl{sup -} ion. These observations are in agreement with the expected trend in the interfacial propensity of anions based on the Hofmeister series.

  7. A CATIONIC POLYACRYLAMIDE DISPERSION SYNTHESIS BY DISPERSION POLYMERIZATION IN AQUEOUS SOLUTION

    OpenAIRE

    Yufeng Wang; Kefu Chen; Lihuan Mo; Huiren Hu,

    2011-01-01

    A cationic polyacrylamide (CPAM) dispersion, the copolymer of acrylamide (AM) and acryloyloxyethyltrimethyl ammonium chloride (DAC), has been synthesized through dispersion polymerization in aqueous ammonium sulfate ((NH4)2SO4) solution. The polymerization was initiated by tert-butyl hydroperoxide (TBHP) and ferrisulfas (FeSO4) using poly(dimethyl diallyl ammonium chloride) (PDMDAAC) as the stabilizer. At the optimal reaction conditions, the relative molecular weight of the CPAM dispersion wa...

  8. Dechlorination of Aromatic Chlorides in Aqueous System Catalyzed by Functionalized MontK10 Supported Palladium-tin

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A novel bisupporter bimetal catalyst PVP-PdCl2-SnCl4/MontK10-PEG400, using for dehalogenation of insoluable aromatic halides in aqueous system, has shown high dechlorination activity and selectivity, without any organic solvent or phase transfer catalyst. The conversion of aromatic chlorides can reach 100%. The catalyst is easy to prepare and has good reusability.

  9. Extraction of Ca (II) and Mg (II) from Hydrochloric Acid Solutions by N, N-Dioctyl-1-Octan Ammonium Chloride in Methyl Isobutyl Ketone

    OpenAIRE

    Fatmir Faiku; Arben Haziri; Imer Haziri; Sali Aliu; Nita Sopa

    2012-01-01

    Problem statement: Amines as organic molecules are able to form complexes with metals ions and this is the reason why we can use them to extract metals ions from hydrometallurgical solutions. Approach: Based on that, we have investigated the extraction of Calcium and Magnesium with N, N-dioctyl-1-octan ammonium chloride from the mixture of elements (Ca and Mg) prepared in artificial manner. We have investigated the influence of HCl concentration and salts (NaCl, NaI and CH3COONa) concentratio...

  10. Controlling the structure and rheology of TEMPO-oxidized cellulose in zinc chloride aqueous suspensions for fabricating advanced nanopaper

    Science.gov (United States)

    Wang, Sha; Zhang, Xin; Hu, Liangbing; Briber, Robert; Wang, Howard; Zhong, Linxin

    Due to its abundance, low-cost, biocompatibility and renewability, cellulose has become an attractive candidate as a functional material for various advanced applications. A key to novel applications is the control of the structure and rheology of suspensions of fibrous cellulose. Among many different approaches of preparing cellulose suspensions, zinc chloride addition to aqueous suspensions is regarded an effective practice. In this study, effects of ZnCl2 concentration on TEMPO-oxidized cellulose (TOC) nanofiber suspensions have been investigated. Highly-transparent cellulose nanofiber suspension can be rapidly obtained by dissolving TOC in 65 wt.% zinc chloride aqueous solutions at room temperature, whereas a transparent zinc ion cross-linked TOC gel could be obtained with zinc chloride concentration as low as 10 wt. %. The structural and rheological characteristics of TOC/ZnCl2 suspensions have been measured to correlate to the performance of thetransparent and flexible nanocellulose paper subsequently produced via vacuum filtration or wet-casting processes.

  11. Aqueous Solutions of the Ionic Liquid 1-butyl-3-methylimidazolium Chloride Denature Proteins

    Energy Technology Data Exchange (ETDEWEB)

    Baker, Gary A [ORNL; Heller, William T [ORNL

    2009-01-01

    As we advance our understanding, ionic liquids (ILs) are finding ever broader scope within the chemical sciences including, most recently, pharmaceutical, enzymatic, and bioanalytical applications. With examples of enzymatic activity reported in both neat ILs and in IL/water mixtures, enzymes are frequently assumed to adopt a quasi-native conformation, even if little work has been carried out to date toward characterizing the conformation, dynamics, active-site perturbation, cooperativity of unfolding transitions, free energy of stabilization, or aggregation/oligomerization state of enzymes in the presence of an IL solvent component. In this study, human serum albumin and equine heart cytochrome c were characterized in aqueous solutions of the fully water-miscible IL 1-butyl-3-methylimidazolium chloride, [bmim]Cl, by small-angle neutron and X-ray scattering. At [bmim]Cl concentrations up to 25 vol.%, these two proteins were found to largely retain their higher-order structures whereas both proteins become highly denatured at the highest IL concentration studied here (i.e., 50 vol.% [bmim]Cl). The response of these proteins to [bmim]Cl is analogous to their behavior in the widely studied denaturants guanidine hydrochloride and urea which similarly lead to random coil conformations at excessive molar concentrations. Interestingly, human serum albumin dimerizes in response to [bmim]Cl, whereas cytochrome c remains predominantly in monomeric form. These results have important implications for enzymatic studies in aqueous IL media, as they suggest a facile pathway through which biocatalytic activity can be altered in these nascent and potentially green electrolyte systems.

  12. The interaction of polycrystalline copper films with dilute aqueous solutions of cupric chloride

    Science.gov (United States)

    Walsh, Lois Harper

    1989-10-01

    In the electronics industry, thin films of copper deposited on substrates are used as electrically conductive paths to interconnect semiconductor devices and other computer components. The dissolution of copper in a dilute aqueous cupric chloride solution was studied to achieve an understanding of the role microstructure plays in the dissolution process. A multi-technique approach was taken using combinations of solution chemistry, computer modeling, and microstructural characterization techniques to analyze as-received samples and to monitor the dissolution process. This latter approach allowed reaction rates and activation energies to be calculated from speciation concentrations derived from computer modeling of known thermochemical reactions. In conjunction with the solution analysis, surface techniques were used to analyze the concentration distribution of the various elements after sample exposure to the etchant. The etching characteristics of the polycrystalline thin copper films are dependent on the film's microstructure. A procedure is suggested that will aid future researchers in the correlation of microstructure and dissolution characteristics of different copper samples prior to mass production of metallization for microelectronic circuits.

  13. Lithium chloride ionic association in dilute aqueous solution: a constrained molecular dynamics study

    Science.gov (United States)

    Zhang, Zhigang; Duan, Zhenhao

    2004-02-01

    Constrained molecular dynamics simulations were carried out to investigate the lithium chloride ionic associations in dilute aqueous solutions over a wide temperature range. Solvent mediated potentials of mean force have been carefully calculated at different thermodynamic conditions. Two intermediate states of ionic association can be well identified with an energy barrier from the oscillatory free energy profile. Clear pictures for the microscopic association structures are presented with a remarkable feature of strong hydration effect of lithium ion and the bridging role of its hydrating complex. Experimental association constants have been reasonably reproduced and a general trend of the increasing ionic association at high temperatures and low densities was observed. Additional simulations with different numbers of water molecules have been performed to check the possible artifacts introducing from periodic and finite size effects and confirm the reliability of our simulation results. Marginal differences of the simulated curves are believed to result from the significant compensation and canceling effect between the bare ionic forces and solvent induced mean force. Finally we confirmed the importance of accurate descriptions of dielectric properties of solvent in the ionic association study.

  14. Removal of Ammonium from Aqueous Solutions by Syrian Natural Ores Containing Zeolite

    International Nuclear Information System (INIS)

    In this paper we study the removal of ammonia from aqueous solutions which have the same concentration of ammonia in the Wady-Kandel water in Lattakia. We used natural Syrian ores containing zeolite. The mechanism was according to ion-exchange process. The results show that the ion-exchange capacity (IEC) has a clear relation with the equilibrium concentration and it was 0.88mg/g when Ce=0.5mg/l. This work shows that for purification 1 m3 of the solution which has 2.3mg/l, we need 2kg of zeolite. The bedvoleum equals 4 in breakthrough point and the exchanged amount of ammonia was 0.2mg/g.(author)

  15. Thermophysical properties of aqueous solution of ammonium-based ionic liquids.

    Science.gov (United States)

    Umapathi, Reddicherla; Attri, Pankaj; Venkatesu, Pannuru

    2014-06-01

    Experimental densities (ρ), ultrasonic sound velocities (u), viscosities (η), and refractive indices (n(D)) of binary mixtures of ammonium-based ionic liquids (ILs) such as diethylammonium acetate (DEAA) [(CH3CH2)2NH][CH3COO], triethylammonium acetate (TEAA) [(CH3CH2)3NH][CH3COO], diethylammonium hydrogen sulfate (DEAS) [(CH3CH2)2NH][HSO4], triethylammonium hydrogen sulfate (TEAS) [(CH3CH2)3NH][HSO4], trimethylammonium acetate (TMAA) [(CH3)3NH][CH3COO], and trimethylammonium hydrogen sulfate (TMAS) [(CH3)3NH][HSO4] with water are reported over the wide composition range at 25 °C under atmospheric pressure. The excess molar volumes (V(E)), deviation in isentropic compressibilities (Δκ(s)), deviation in viscosities (Δη) and deviation in refractive indices (Δn(D)) are calculated from experimental values and are correlated by Redlich-Kister polynomial equations. The V(E) and Δκ(s) values for the aforesaid systems are negative over the entire composition range while the Δη and Δn(D) values are positive under the same experimental conditions. The intermolecular interactions and structural effects were analyzed on the basis of measured and derived properties. A qualitative analysis of the results is discussed in terms of the ion-dipole, ion-pair interactions and hydrogen bonding between ILs and water. Furthermore, the hydrogen bonding features between ILs with water were analyzed by using a molecular modeling program with the help of HyperChem7. PMID:24830564

  16. A microcalorimetric study of {beta}-cyclodextrin with 3-alkoxyl-2-hydroxypropyl trimethyl ammonium bromides in aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Sun Dezhi [Department of Chemistry, Liaocheng University, Wenhua Road, Liaocheng, Shandong 252059 (China)]. E-mail: sundezhisdz@163.com; Wang Shibing [Department of Chemistry, Liaocheng University, Wenhua Road, Liaocheng, Shandong 252059 (China); Wei Xilian [Department of Chemistry, Liaocheng University, Wenhua Road, Liaocheng, Shandong 252059 (China); Yin Baolin [Department of Chemistry, Liaocheng University, Wenhua Road, Liaocheng, Shandong 252059 (China)

    2005-05-15

    We have investigated with titration microcalorimetry {beta}-cyclodextrin with 3-alkoxyl-2-hydroxypropyl trimethyl ammonium bromides, which is a new surfactant synthesized in this laboratory, in aqueous solutions at a temperature of 298.15 K. The results are discussed in the light of amphiphilic interaction and the complex formed of water molecules around a hydrophobic surfactant tail. The stoichiometry of the (host + guest) complex changes from 1:1 to 2:1, as the number of carbon atoms n in the hydrophobic chain, C{sub n}H{sub 2n+1}O, increases from 8 to 14. All the complexes are stable with the apparent experimentally determined stability constants of {beta}{sub 1} 1.08 . 10{sup 3} dm{sup 3} . mol{sup -1}, {beta}{sub 1} = 28.66 . 10{sup 3} dm{sup 3} . mol{sup -1} and {beta}{sub 2} = 141.9 . 10{sup 3} dm{sup 6} . mol{sup -2} for n = 8, 12 and 14, respectively. The enthalpy decreases with increasing n of the hydrophobic chain.

  17. Nontoxic, Inexpensive, Ammonium Chloride-Mediated (In Water) Synthesis of Some Novel 1,5-benzothiazepine Derivatives and Their Antimicrobial Activity

    International Nuclear Information System (INIS)

    In the present study, a new, nontoxic, easy and inexpensive method for the synthesis of 1,5-benzothiazepine derivatives was described and a mechanism for this reactions was proposed. Ammonium chloride which is inexpensive and readily available reagent catalyzes the thia-michael addition reaction of thiols in water efficiently. 1,5-benzothiazepines derivatives were synthesized by the condensation reactions of o-aminothiophenol (o-ATP) with chalcone derivatives by using saturated solution of NH/sub 4/Cl in water. The products were characterized by the elemental analysis, NMR and FT-IR techniques. Synthesized compounds were tested for antimicrobial activity against. Staphylococcus aureus ATCC 6538, Escherichia coli ATCC 25922, Bacillus subtilis IMG22 and Candida albicans ATCC 10231. Among the synthesized compounds 2b was found to be most active derivative against Escherichia coli ATCC 25922 and Candida albicans ATCC 10231. The other compounds didn't exhibit any activity against the other test microorganisms. (author)

  18. Synthesis of his-quaternary ammonium peroxotungstates (peroxomolybdates)and their catalytic activity in oxidation of alcohols by aqueous H2O2

    Institute of Scientific and Technical Information of China (English)

    SHI Xianying; WEI Junfa

    2007-01-01

    Three kinds of bis-quaternary ammonium salts of peroxotungstate and peroxomolybdate,such as PhCH2NO(O2)2(C2O4)] and PhCH2N(CH2)6NCH2Ph [MoO(O2)2(C2Oa)],have been synthesized and characterized.Their catalytic activity in the oxidation of cyclohexanol and benzyl alcohol was investigated with only aqueous 30% hydrogen peroxide.The results show that the bis-quaternary ammonium peroxotungstates are excellent catalysts in the oxidation of benzyl alcohol and cyclohexanol under moderate conditions.However,the catalytic ability of bis-quaternary ammonium peroxomolybadates is relatively poor.The yields of benzyl acid,benzaldehyde,and cyclohexanone reached up to 93.0%,93.6%,and 91.7%,respectively.

  19. Study of an aqueous lithium chloride desiccant system Part II: Desiccant regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Fumo, Nelson [Universidad Nacional Experimental del Tachira, San Cristobal (Venezuela); Goswami, Yogi [University of Florida, Gainesville (United States)

    2000-07-01

    Desiccant systems have been proposed as alternative to handle the latent load in vapor compression air conditioning for energy saving. The air dehumidification occurs because of the difference in vapor pressure which let the moisture diffuse from the air to the liquid desiccant. The diffused moisture cause a dilution of the desiccant which must be regenerated to return it to the original conditions. This paper presents the results from a study of the performance of a packed tower regenerator for an aqueous lithium chloride desiccant dehumidification system. The rate of water evaporation, as well as the effectiveness of the regeneration process were assessed under the effects of variables such as air and desiccant flow rates, air temperature and humidity, and desiccant temperature and concentration. A variation of the oeberg and Goswami mathematical model was used to predict the experimental findings given satisfactory results. [Spanish] Se han propuesto sistemas desecantes para hacerse cargo de la carga latente en acondicionamiento de aire por compresion de vapor para el ahorro de energia. La deshumidificacion del aire ocurre en razon de la diferencia de presion de vapor que deja la humedad difusa del aire en el desecante liquido. La humedad difusa del aire origina una dilucion del desecante el cual debe de ser regenerado para regresarlo a sus condiciones originales. Este documento presenta los resultados de un estudio sobre el comportamiento de un regenerador de torre empacada para un sistema de deshumidificacion de solucion desecante de cloruro de litio. El regimen de evaporacion de agua, asi como tambien la efectividad del proceso de regeneracion que se evaluo bajo los efectos de variables tales como los regimenes de flujo de aire y de desecante, temperatura del aire y humedad, y temperatura y concentracion del desecante. Una variacion del modelo matematico de Oberg y Goswami se uso para predecir los resultados experimentales que dieron resultados satisfactorios.

  20. Study of an aqueous lithium chloride desiccant system Part I: Air dehumidification

    Energy Technology Data Exchange (ETDEWEB)

    Fumo, Nelson [Universidad Nacional Experimental del Tachira, San Cristobal (Venezuela); Goswami, Yogi [University of Florida, Gainesville (United States)

    2000-07-01

    Desiccant systems have been proposed as energy saving alternative to vapor compression air conditioning for handling the latent load. Use of liquid desiccants offers several design and performance advantages over solid desiccants, especially when solar energy is used for regeneration. For liquid-gas contact, packed towers with low pressure drop have offered good heat and mass transfer characteristics for compact designs. This paper presents the results from a study of the performance of a packed tower absorber for an aqueous lithium chloride desiccant dehumidification system. The rate of dehumidification, as well as the effectiveness of the dehumidification process were assessed under the effects of variables such as air and desiccant flow rates, air temperature and humidity, and desiccant temperature and concentration. A variation of the oeberg and Goswami mathematical model was used to predict the experimental findings given satisfactory results. [Spanish] Se han propuesto sistemas de desecacion como una alternativa de ahorro de energia para el acondicionamiento de aire mediante la compresion de vapor para manejar la carga latente. El uso de desecantes liquidos ofrece varias ventajas de diseno y de rendimiento sobre los desecantes solidos, especialmente cuando la energia solar se usa para la regeneracion. Para el contacto liquido-gas han dado buenas caracteristicas de transferencia de masa para disenos compactos las torres empacadas con baja caida de presion. Este documento presenta los resultados de un estudio del comportamiento de un absorbedor de torre empacada para una solucion acuosa de desecante de cloruro de litio como sistema de deshumidificacion. El regimen de deshumidificacion asi como tambien la eficiencia del proceso de deshumidificacion se evaluo bajo los efectos de variables tales como regimenes de flujo de aire y de desecante, temperatura del aire y humedad, y concentracion y temperatura del desecante. Se uso una variante de modelo matematico de

  1. Experimental and numerical study on effects of airflow and aqueous ammonium solution temperature on ammonia mass transfer coefficient.

    Science.gov (United States)

    Rong, Li; Nielsen, Peter V; Zhang, Guoqiang

    2010-04-01

    This paper reports the results of an investigation, based on fundamental fluid dynamics and mass transfer theory, carried out to obtain a general understanding of ammonia mass transfer from an emission surface. The effects of airflow and aqueous ammonium solution temperature on ammonia mass transfer are investigated by using computational fluid dynamics (CFD) modeling and by a mechanism modeling using dissociation constant and Henry's constant models based on the parameters measured in the experiments performed in a wind tunnel. The validated CFD model by experimental data is used to investigate the surface concentration distribution and mass transfer coefficient at different temperatures and velocities for which the Reynolds number is from 1.36 x 10(4) to 5.43 x 10(4) (based on wind tunnel length). The surface concentration increases as velocity decreases and varies greatly along the airflow direction on the emission surface. The average mass transfer coefficient increases with higher velocity and turbulence intensity. However, the mass transfer coefficient estimated by CFD simulation is consistently larger than the calculated one by the method using dissociation constant and Henry's constant models. In addition, the results show that the liquid-air temperature difference has little impact on the simulated mass transfer coefficient by CFD modeling, whereas the mass transfer coefficient increases with higher liquid temperature using the other method under the conditions that the liquid temperature is lower than the air temperature. Although there are differences of mass transfer coefficients between these two methods, the mass transfer coefficients determined by these two methods are significantly related.

  2. Effects of cationic ammonium gemini surfactant on micellization of PEO-PPO-PEO triblock copolymers in aqueous solution.

    Science.gov (United States)

    Wang, Ruijuan; Tang, Yongqiang; Wang, Yilin

    2014-03-01

    Effects of cationic ammonium gemini surfactant hexamethylene-1,6-bis(dodecyldimethylammonium bromide) (12-6-12) on the micellization of two triblock copolymers of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide), F127 (EO97PO69EO97) and P123 (EO20PO70EO20), have been studied in aqueous solution by differential scanning calorimetry (DSC), dynamic light scattering (DLS), isothermal titration calorimetry (ITC), and NMR techniques. Compared with traditional single-chain ionic surfactants, 12-6-12 has a stronger ability of lowering the CMT of the copolymers, which should be attributed to the stronger aggregation ability and lower critical micelle concentration of 12-6-12. The critical micelle temperature (CMT) of the two copolymers decreases as the 12-6-12 concentration increases and the ability of 12-6-12 in lowering the CMT of F127 is slightly stronger than that of P123. Moreover, a combination of ITC and DLS has shown that 12-6-12 binds to the copolymers at the temperatures from 16 to 40 °C. At the temperatures below the CMT of the copolymers, 12-6-12 micelles bind on single copolymer chains and induce the copolymers to initiate aggregation at very low 12-6-12 concentration. At the temperatures above the CMT of the copolymers, the interaction of 12-6-12 with both monomeric and micellar copolymers leads to the formation of the mixed copolymer/12-6-12 micelles, then the mixed micelles break into smaller mixed micelles, and finally free 12-6-12 micelles form with the increase of the 12-6-12 concentration. PMID:24528103

  3. Computational Study of the Structure and Thermodynamic Properties of Ammonium Chloride Clusters Using a Parallel J-Walking Approach

    CERN Document Server

    Matro, A; Topper, R Q; Matro, Alexander; Freeman, David L.; Topper, Robert Q.

    1996-01-01

    The thermodynamic and structural properties of (NH$_4$Cl)$_n$ clusters, n=3-10 are studied. Using the method of simulated annealing, the geometries of several isomers for each cluster size are examined. Jump-walking Monte Carlo simulations are then used to compute the constant-volume heat capacity for each cluster size over a wide temperature range. To carry out these simulations a new parallel algorithm is developed using the Parallel Virtual Machine (PVM) software package. Features of the cluster potential energy surfaces, such as energy differences among isomers and rotational barriers of the ammonium ions, are found to play important roles in determining the shape of the heat capacity curves.

  4. Shock Hugoniot and equations of states of water, castor oil, and aqueous solutions of sodium chloride, sucrose and gelatin

    Science.gov (United States)

    Gojani, A. B.; Ohtani, K.; Takayama, K.; Hosseini, S. H. R.

    2016-01-01

    This paper reports a result of experiments for the determination of reliable shock Hugoniot curves of liquids, in particular, at relatively low pressure region, which are needed to perform precise numerical simulations of shock wave/tissue interaction prior to the development of shock wave related therapeutic devices. Underwater shock waves were generated by explosions of laser ignited 10 mg silver azide pellets, which were temporally and spatially well controlled. Measuring temporal variation of shock velocities and over-pressures in caster oil, aqueous solutions of sodium chloride, sucrose and gelatin with various concentrations, we succeeded to determine shock Hugoniot curves of these liquids and hence parameters describing Tait type equations of state.

  5. Growth kinetics for the precipitation of zirconium hydroxide from aqueous zirconium and tin bearing solutions by the addition of ammonium hydroxide

    Energy Technology Data Exchange (ETDEWEB)

    Carleson, T.E. [Idaho Univ., Moscow, ID (United States). Dept. of Chemical Engineering; Chipman, N.A. [Westinghouse Idaho Nuclear Co., Inc., Idaho Falls, ID (United States)

    1989-09-11

    The precipitation of zirconium hydroxide from an aqueous solution of ammonium hexafluorozirconate occurs rapidly upon addition of ammonium hydroxide. Experimental data indicate growth and nucleation rates between 0.06 and 0.28 microns/minute and around 10 {times} 107 number/L-min, respectively. Experiments with a mixed suspension mixed product removal crystallizer for concentrations of reactants of about 0.05 M ammonium hexafluorozirconate precipitating with 0.002 M ammonium hydroxide showed apparent nonlinear growth rates in some cases but not others. Batch studies indicated that growth rate dispersion is probably not present. When the AFL nonlinear model was used to fit the data, the power coefficient obtained was greater than 1, in disagreement with theory. In addition, for some of the data ``S`` shaped curves of the logarithm of the cumulative number greater than versus size were obtained. These curves can not be fit by the AFL model. A program developed at the University of Arizona was used to simulate the crystallization runs. The program results indicated that some of the nonlinear behavior may be attributed to transient conditions. Experimental data also illustrated this behavior. The effect of trace amounts of tin fluoride (0.008 M) on the nucleation and growth kinetics was also evaluated. For some residence times, the presence of tin resulted in reduced median particle diameters, higher growth rates, and lower number counts.

  6. 氯化铵和氯化钾对太湖黄泥土磷的吸持动力学影响的研究%Effects of ammonium chloride and potassium chloride on kinetics of phosphorus sorption of Taihu Paddy soil

    Institute of Scientific and Technical Information of China (English)

    李寿田; 周健民; 王火焰; 杜昌文; 陈小琴

    2012-01-01

    土壤中磷的移动性、植物有效性和对水体环境的潜在危害性与土壤对磷的吸持反应有关,而铵钾磷共施是农业生产中的普遍现象,因此,本文通过批量培养法,研究了相同摩尔数的氯化铵和氯化钾对磷的吸持动力学的影响,并对磷的吸持动力学进行了不同模型的拟合.结果表明,氯化铵、氯化钾均显著增加了土壤对磷的吸持,在培养初期(5 min),相同摩尔数的氯化铵、氯化钾对磷的吸持量无显著差异,但在15 min ~ 10 d阶段,相同摩尔数的氯化钾对磷吸持量的影响显著大于相同摩尔数的氯化铵.而铵钾共施时,两者对磷的吸持具有协同作用,并主要表现为氯化钾的作用.氯化铵对土壤磷吸持总量无显著影响,氯化钾则显著增加了土壤磷吸持总量,氯化钾和氯化铵处理土壤磷吸收总量则无显著差异.通过比较不同模型拟合的决定系数(R2)大小,不同模型拟合效果顺序为Elovich方程>双常数方程>Parabolic扩散方程>零级方程>一级方程>二级方程.%Translocation, plant availability, and hazard potential to water environment of soil phosphorus are related with phosphorus sorption of soil, and it is very common to apply fertilizer by compounding ammonium, potassium and phosphorus together in agricultural production. In this article, the effects of ammonium chloride and potassium chloride on kinetics of phosphorus sorption of paddy soil were conducted by the batch culture, and kinetics of phosphorus sorption was fitted to different models. The results showed that amounts of adsorbed phosphorus were significantly increased by the addition of ammonium chloride and potassium chloride, and there is no significant difference in amounts of phosphorus sorption between ammonium chloride and potassium chloride at the same mole number at the initial culture period, but amounts of phosphorus sorption treated with potassium chloride was significantly more than

  7. Ammonium chloride salting out extraction/cleanup for trace-level quantitative analysis in food and biological matrices by flow injection tandem mass spectrometry.

    Science.gov (United States)

    Nanita, Sergio C; Padivitage, Nilusha L T

    2013-03-20

    A sample extraction and purification procedure that uses ammonium-salt-induced acetonitrile/water phase separation was developed and demonstrated to be compatible with the recently reported method for pesticide residue analysis based on fast extraction and dilution flow injection mass spectrometry (FED-FI-MS). The ammonium salts evaluated were chloride, acetate, formate, carbonate, and sulfate. A mixture of NaCl and MgSO4, salts used in the well-known QuEChERS method, was also tested for comparison. With thermal decomposition/evaporation temperature of residual under typical electrospray conditions, leading to consistent method performance and less instrument cleaning. Although all ammonium salts tested induced acetonitrile/water phase separation, NH4Cl yielded the best performance, thus it was the preferred salting out agent. The NH4Cl salting out method was successfully coupled with FI/MS/MS and tested for fourteen pesticide active ingredients: chlorantraniliprole, cyantraniliprole, chlorimuron ethyl, oxamyl, methomyl, sulfometuron methyl, chlorsulfuron, triflusulfuron methyl, azimsulfuron, flupyrsulfuron methyl, aminocyclopyrachlor, aminocyclopyrachlor methyl, diuron and hexazinone. A validation study was conducted with nine complex matrices: sorghum, rice, grapefruit, canola, milk, eggs, beef, urine and blood plasma. The method is applicable to all analytes, except aminocyclopyrachlor. The method was deemed appropriate for quantitative analysis in 114 out of 126 analyte/matrix cases tested (applicability rate=0.90). The NH4Cl salting out extraction/cleanup allowed expansion of FI/MS/MS for analysis in food of plant and animal origin, and body fluids with increased ruggedness and sensitivity, while maintaining high-throughput (run time=30s/sample). Limits of quantitation (LOQs) of 0.01mgkg(-1) (ppm), the 'well-accepted standard' in pesticide residue analysis, were achieved in >80% of cases tested; while limits of detection (LODs) were typically in the range of 0

  8. Effect of electrolytes on surface tension and surface adsorption of 1-hexyl-3-methylimidazolium chloride ionic liquid in aqueous solution

    International Nuclear Information System (INIS)

    Surface and bulk properties of 1-hexyl-3-methylimidazolium chloride [C6mim][Cl] as an ionic liquid (IL) have been investigated by surface tension and electrical conductivity techniques at various temperatures. Results reveal that the ionic liquid behaves as surfactant-like and aggregates in aqueous solution. Critical aggregation concentration (cac) values obtained by conductivity and surface tension measurements are in good agreement with values found in the literature. A series of important and useful adsorption parameters including cac, surface excess concentration (Γ), and minimum surface area per molecule (Amin) at the air + water interface were estimated from surface tension in the presence and absence of different electrolytes. Obtained data show that the surface tension as well as the cac of [C6mim][Cl] is reduced by electrolytes. Also, values of surface excess concentration (Γ) show that the IL ions in the presence of electrolyte have much larger affinity to adsorption at the surface and this affinity increased in aqueous electrolyte solution in the order of I- > Br- > Cl- for counter ion of salts that was explained in terms of a larger repulsion of chloride anions from interface to the bromide and iodide anion as well as difference in their excess polarizability.

  9. Slow dynamics of water molecules in an aqueous solution of lithium chloride probed by neutron spin-echo.

    Science.gov (United States)

    Mamontov, E; Ohl, M

    2013-07-14

    Aqueous solutions of lithium chloride are uniquely similar to pure water in the parameters such as glass transition temperature, Tg, yet they could be supercooled without freezing down to below 200 K even in the bulk state. This provides advantageous opportunity to study low-temperature dynamics of water molecules in water-like environment in the bulk rather than nano-confined state. Using high-resolution neutron spin-echo data, we argue that the critical temperature, Tc, which is also common between lithium chloride aqueous solutions and pure water, is associated with the split of a secondary relaxation from the main structural relaxation on cooling down. Our results do not allow distinguishing between a well-defined separate secondary relaxation process and the "excess wing" scenario, in which the temperature dependence of the secondary relaxation follows the main relaxation. Importantly, however, in either of these scenarios the secondary relaxation is associated with density-density fluctuations, measurable in a neutron scattering experiment. Neutron scattering could be the only experimental technique with the capability of providing information on the spatial characteristics of the secondary relaxation through the dependence of the signal on the scattering momentum transfer. We propose a simple method for such analysis. PMID:23689686

  10. Stability enhancement of PbSe quantum dots via post-synthetic ammonium chloride treatment for a high-performance infrared photodetector.

    Science.gov (United States)

    Fu, Chunjie; Wang, Haowei; Song, Taojian; Zhang, Li; Li, Weile; He, Bo; sulaman, Muhammad; Yang, Shengyi; Zou, Bingsuo

    2016-02-12

    Infrared (IR) emission lead selenide (PbSe) quantum dots (QDs) have gained considerable attention in the last decade due to their potential applications in optoelectronic devices. However, the comprehensive applications of PbSe QDs have not been realized yet due to their high susceptibility to oxidation in air. In this paper, we demonstrate the stability enhancement of PbSe colloidal QDs via a post-synthetic ammonium chloride treatment and its applications in a solution-processed high-performance IR photodetector with a field-effect transistor (FET) configuration by reversely fabricating the PbSe active layer and polymethylmethacrylate (PMMA) dielectric layer. The responsivity and the specific detectivity of the FET-based photodetector Au(source, drain)/PbSe(52 nm)/PMMA(930 nm)/Au(gate) reached 64.17 mA W(-1) and 5.08 × 10(10) Jones, respectively, under 980 nm laser illumination with an intensity of 0.1 mW cm(-2). Therefore, it provides a promising way to make a high-sensitivity near-IR/mid-IR photodetector.

  11. Stability enhancement of PbSe quantum dots via post-synthetic ammonium chloride treatment for a high-performance infrared photodetector

    Science.gov (United States)

    Fu, Chunjie; Wang, Haowei; Song, Taojian; Zhang, Li; Li, Weile; He, Bo; sulaman, Muhammad; Yang, Shengyi; Zou, Bingsuo

    2016-02-01

    Infrared (IR) emission lead selenide (PbSe) quantum dots (QDs) have gained considerable attention in the last decade due to their potential applications in optoelectronic devices. However, the comprehensive applications of PbSe QDs have not been realized yet due to their high susceptibility to oxidation in air. In this paper, we demonstrate the stability enhancement of PbSe colloidal QDs via a post-synthetic ammonium chloride treatment and its applications in a solution-processed high-performance IR photodetector with a field-effect transistor (FET) configuration by reversely fabricating the PbSe active layer and polymethylmethacrylate (PMMA) dielectric layer. The responsivity and the specific detectivity of the FET-based photodetector Au(source, drain)/PbSe(52 nm)/PMMA(930 nm)/Au(gate) reached 64.17 mA W-1 and 5.08 × 1010 Jones, respectively, under 980 nm laser illumination with an intensity of 0.1 mW cm-2. Therefore, it provides a promising way to make a high-sensitivity near-IR/mid-IR photodetector.

  12. Application of In-Line Mid-Infrared (MIR) Spectroscopy Coupled with Calorimetry for the Determination of the Molar Enthalpy of Reaction between Ammonium Chloride and Sodium Nitrite.

    Science.gov (United States)

    Kartnaller, Vinicius; Mariano, Danielly C O; Cajaiba, João

    2016-03-01

    The reaction between ammonium chloride and sodium nitrite has been known for its application as a source of heat because of its large enthalpy of reaction, for which it has been used by the oil industry. There have been no known calorimetric studies for the experimental determination of its molar enthalpy of reaction, which is necessary in order to predict the limits achieved for up-scale applications. Attenuated total reflection Fourier transform infrared spectroscopy (ATR FT-IR) and reaction calorimetry were used to determine this value by using a simple methodology. Both techniques were used concomitantly as a source of information regarding the time-dependent moles converted (Δn) and the amount of exchanged heat (ΔH). The molar enthalpy of reaction was calculated to be -74 ± 4 kcal mol(-1). The percentage between the confidence interval and the calculated value was 5.4%, which shows that the methodology was precise. After the determination of the molar enthalpy of reaction, it was proved that the ATR FT-IR alone was able to be used as a substitute for the reaction calorimetry technique, in which the IR signal is converted to the heat information, presenting as an easier technique for the monitoring of the heat released by this system for future applications.

  13. Extraction of Ca (II and Mg (II from Hydrochloric Acid Solutions by N, N-Dioctyl-1-Octan Ammonium Chloride in Methyl Isobutyl Ketone

    Directory of Open Access Journals (Sweden)

    Fatmir Faiku

    2012-01-01

    Full Text Available Problem statement: Amines as organic molecules are able to form complexes with metals ions and this is the reason why we can use them to extract metals ions from hydrometallurgical solutions. Approach: Based on that, we have investigated the extraction of Calcium and Magnesium with N, N-dioctyl-1-octan ammonium chloride from the mixture of elements (Ca and Mg prepared in artificial manner. We have investigated the influence of HCl concentration and salts (NaCl, NaI and CH3COONa concentration in extraction of two elements (Ca and Mg from water solutions. All extractions were done from HCl water solutions with c = 3, 6 and 9 mol L-1 and in presence of NaCl, NaI and CH3COONa salts, which we prepared in different concentrations. Results: Extraction of Calcium from NaCl solution move from 18-30%, from NaI solution 55-77% and from CH3COONa solution 50-71%. Extraction of Magnesium from NaCl solution move from 3-12%, from NaI solution 0-11% and from CH3COONa solution 0-8%. Conclusion: As optimal condition to separate Calcium from Magnesium is the extraction of Calcium from HCl solution with concentration 9 mol L-1 in presence of NaI with concentration of 60 g L-1. Using these condition 77% of Calcium was in organic phase and all of magnesium remains in water phase.

  14. Guest gas enclathration in tetra-n-butyl ammonium chloride (TBAC) semiclathrates: Potential application to natural gas storage and CO2 capture

    International Nuclear Information System (INIS)

    Highlights: • TBAC forms semiclathrates with CH4 and CO2. • The highest stabilization of TBAC semiclathrates was observed at 3.3 mol%. • The inclusion of CH4 and CO2 in semiclathrates was examined via spectroscopic methods. • TBAC semiclathrates can be applied to gas storage and CO2 capture. - Abstract: The enclathration of guest gases such as CH4 and CO2 in tetra-n-butyl ammonium chloride (TBAC) semiclathrates and their potential application to natural gas storage and CO2 capture were examined with a primary focus on stability condition measurements and cage filling characteristics. The phase behaviors clearly demonstrated that the double CH4 (or CO2) + TBAC semiclathrates yielded a significantly enhanced thermodynamic stability. In particular, the highest stabilization occurred at 3.3 mol%, the stoichiometric concentration of TBAC·29.7H2O. The cage-dependent 13C NMR chemical shift identified CH4 molecules enclathrated in the small 512 cages of the double TBAC semiclathrates. CO2 inclusion in the double TBAC semiclathrate was also confirmed using Raman spectroscopy. In addition, the dissociation enthalpy and the dissociation temperature of the TBAC semiclathrate under atmospheric pressure were measured to be 204.8 ± 1.7 J/g and 288.0 K, respectively, by a differential scanning calorimeter. The experimental results demonstrate that TBAC semiclathrates can potentially be used for gas storage and CO2 capture due to their high thermodynamic stability and favorable enclathration characteristics of guest gases

  15. Processo de organofilização de vermiculia brasileira com cloreto de cetiltrimetilamônio Organophilization process of Brazilian vermiculite with cetyltrimethyl ammonium chloride

    Directory of Open Access Journals (Sweden)

    E. V. D Gomes

    2010-03-01

    Full Text Available A vermiculita, argila da família dos aluminossilicatos 2:1 proveniente do estado de Goiás, Brasil, foi utilizada para a produção de uma argila organofílica. A vermiculita foi primeiramente submetida ao tratamento com cloreto de sódio para a obtenção de uma argila homoiônica sódica. A argila organofílica foi, então, obtida a partir da síntese com o sal de amônio quaternário, cloreto de cetiltrimetil amônio. As argilas, tratada com o sal orgânico e a não tratada, foram caracterizadas por espectrometria de fluorescência de raios X, espectroscopia de absorção na região do infravermelho, difração de raios X e análise termogravimétrica. Os resultados de fluorescência de raios X evidenciaram a mudança na composição química da vermiculita após as reações de troca com NaCl e sal orgânico. Os resultados obtidos por espectroscopia de absorção na região do infravermelho mostraram a presença dos grupos característicos do sal na argila e os de difração de raios X confirmaram sua intercalação entre as camadas da argila. Os resultados de análise termogravimétrica mostraram que a argila organofílica apresentou outras faixas de decomposição, além daquelas apresentadas pela vermiculita natural, correspondentes à decomposição do sal de amônio quaternário.The vermiculite (VMT, 2:1 aluminosilicate family clay from the state of Goiás, Brazil, was used for the production of an organophilic clay. First, the VMT was treated with sodium chloride to obtain the homo-ionic sodium clay. The organophilic clay was, then, obtained from the reaction with the quaternary ammonium salt, cetyltrimethyl ammonium chloride. The clay treated with organic salt and the untreated one were characterized by X-ray fluorescence spectrometry (XRF, Fourier transform infrared spectroscopy (FTIR, X-ray diffraction (XRD and thermogravimetric analysis (TGA. The results of XRF evidenced the change in the chemical composition of the VMT after the

  16. Viscosity of aqueous-glyceric solutions of potassium, rubidium and cesium chlorides

    International Nuclear Information System (INIS)

    Results of viscometric investigation of the solutions of rubidium and cesium chlorides (also potassium chloride for comparison) in mixtures water-glycerine at 15, 25, 35 and 45 deg C are presented. Glycerine content constituted 0.01; 0.03; 0.05; 0.07; 0.11 molar fractions. It is shown that the range of viscosity values lower as compared to the ones for pure solvent are the wider the lower the temperature and glycerine content are (in the range of 0.01-0.11 molar fractions). The composition-viscosity, temperature-viscosity diagrams are presented

  17. Slow strain rate behavior of TiCode 12 (ASTM Gr.12) in aqueous chloride solutions

    International Nuclear Information System (INIS)

    Slow strain rate testing has shown that the macroscopic tensile properties of mill-annealed TiCode 12 are not affected by exposure to either a synthetic seawater or high chloride brine environment. However, microscopic examination indicates that the fracture mode may be sensitive to environment. This sensitivity appears to be related to hydrogen ingress during prolonged exposure

  18. Efficient adsorption of both methyl orange and chromium from their aqueous mixtures using a quaternary ammonium salt modified chitosan magnetic composite adsorbent.

    Science.gov (United States)

    Li, Kun; Li, Pei; Cai, Jun; Xiao, Shoujun; Yang, Hu; Li, Aimin

    2016-07-01

    A quaternary ammonium salt modified chitosan magnetic composite adsorbent (CS-CTA-MCM) was prepared by combination of Fe3O4 nanoparticles. Various techniques were used to characterize the molecular structure, surface morphology, and magnetic feature of this composite adsorbent. CS-CTA-MCM was employed for the removal of Cr(VI) and methyl orange (MO), an anionic dye, from water in respective single and binary systems. Compared with chitosan magnetic adsorbent (CS-MCM) without modification, CS-CTA-MCM shows evidently improved adsorption capacities for both pollutants ascribed to the additional quaternary ammonium salt groups. Based on the adsorption equilibrium study, MO bears more affinity to CS-CTA-MCM than Cr(VI) causing a considerable extent of preferential adsorption of dye over metal ions in their aqueous mixture. However, at weak acidic solutions, Cr(VI) adsorption is evidently improved due to more efficient Cr(VI) forms, i.e. dichromate and monovalent chromate, binding to this chitosan-based adsorbent. Thus chromium could be efficient removal together with MO at suitable pH conditions. The adsorption isotherms and kinetics indicate that adsorptions of Cr(VI) and MO by CS-CTA-MCM both follow a homogeneous monolayer chemisorption process. This magnetic adsorbent after saturated adsorption could be rapidly separated from water and easily regenerated using dilute NaOH aqueous solutions then virtually reused with little adsorption capacity loss. PMID:27060639

  19. Aqueous systems of ethanolamine hydrochlorides and of chlorides of cerium, terbium, dysprosium, erbium

    International Nuclear Information System (INIS)

    The isothermal method of cross sections has been used to study the solubility at 25 and 50 deg C in ternary water-salt systems consisting of cerium chloride and mono-(1), di-(2) and triethanolamine (3) hydrochlorides as well as diethanolamine hydrochloride and terbium, dysprosium and erbium chlorides. Solubility isotherms testify to the formation in the system (1) of a congruently dissolved compound of the CeCl3x2(C2H4OHNN2HCl)x2H2O composition. Individual peculiarities of a new solid phase are proved by the DTA method by means of derivatograph ODL-106, while the composition is confirmed by chemical analysis. The rest of the systems - are of simple eutonic type

  20. Removal of sodium and chloride ions from aqueous solutions using fique fibers (Furcraea spp.).

    Science.gov (United States)

    Agudelo, Nikolay; Hinestroza, Juan P; Husserl, Johana

    2016-01-01

    Fique fibers obtained from the leaves of Furcraea spp., a highly abundant plant in the mountains of South America, may offer an alternative as biosorbents in desalination processes as they exhibit high removal capacities (13.26 meq/g for chloride ions and 15.52 meq/g for sodium ions) up to four times higher than exchange capacities commonly observed in synthetic resins. The ion removal capacity of the fibers was also found to be a function of the pH of the solution with the maximum removal of ions obtained at pH 8. Unlike most commercial ion exchange resins, our results suggest that fique fibers allow simultaneous removal of chloride and sodium ions.

  1. Accounting for Electronic Polarization Effects in Aqueous Sodium Chloride via Molecular Dynamics Aided by Neutron Scattering.

    Science.gov (United States)

    Kohagen, Miriam; Mason, Philip E; Jungwirth, Pavel

    2016-03-01

    Modeled ions, described by nonpolarizable force fields, can suffer from unphysical ion pairing and clustering in aqueous solutions well below their solubility limit. The electronic continuum correction takes electronic polarization effects of the solvent into account in an effective way by scaling the charges on the ions, resulting in a much better description of the ionic behavior. Here, we present parameters for the sodium ion consistent with this effective polarizability approach and in agreement with experimental data from neutron scattering, which could be used for simulations of complex aqueous systems where polarization effects are important.

  2. Cooling and Freezing Behaviors of Aqueous Sodium Chloride Solution in a Closed Rectangular Container

    Science.gov (United States)

    Narumi, Akira; Kashiwagi, Takao; Nakane, Ichirou

    This paper investigates cooling and freezing behaviors of NaCl aqueous solution in a rectangular container equipped with horizontal partitions of micro porous film in order to determine the mechanisms of heat and mass transfer through cell wall for the purpose of freezing food. For comparison, experiments were performed using partitions of copper plate, no partition, and water. These processes were visualized and measured using real-time laser holographic interferometry. It was found that there was very little difference in the cooling process due to partitions, but that there were significant differences in freezing process when NaCl aqueous solution is used.

  3. Biological evaluation of N-2-hydroxypropyl trimethyl ammonium chloride chitosan as a carrier for the delivery of live Newcastle disease vaccine.

    Science.gov (United States)

    Zhao, Kai; Sun, Yanwei; Chen, Gang; Rong, Guangyu; Kang, Hong; Jin, Zheng; Wang, Xiaohua

    2016-09-20

    Mucosal immune system plays a very important role in antiviral immune response. We prepared Newcastle disease viruses (NDV) encapsulated in N-2-hydroxypropyl trimethyl ammonium chloride chitosan (N-2-HACC) nanoparticles (NDV/La Sota-N-2-HACC-NPs) by an ionic cross linking method, and assessed the potential of N-2-HACC-NPs as a mucosal immune delivery carrier. The properties of the nanoparticles were determined by transmission electron microscopy, Zeta potential and particle size analysis, encapsulation efficiency and loading capacity. NDV/La Sota-N-2-HACC-NPs have regular spherical morphologies and high stability; with 303.88±49.8nm mean diameter, 45.77±0.75mV Zeta potential, 94.26±0.42% encapsulation efficiency and 54.06±0.21% loading capacity. In vitro release assay indicated that the release of NDV from NDV/La Sota-N-2-HACC-NPs is slow. The NDV/La Sota-N-2-HACC-NPs have good biological characteristics, very low toxicity and high level of safety. Additionally, specific pathogen-free chickens immunized with NDV/La Sota-N-2-HACC-NPs showed much stronger cellular, humoral and mucosal immune responses than commercial attenuated live Newcastle disease vaccine, and NDV/La Sota-N-2-HACC-NPs reached the sustainable release effect. Our study here provides a foundation for the further development of mucosal vaccines and drugs, and the N-2-HACC-NPs should be a potential drug delivery carrier with immense potential in medical applications.

  4. Biological evaluation of N-2-hydroxypropyl trimethyl ammonium chloride chitosan as a carrier for the delivery of live Newcastle disease vaccine.

    Science.gov (United States)

    Zhao, Kai; Sun, Yanwei; Chen, Gang; Rong, Guangyu; Kang, Hong; Jin, Zheng; Wang, Xiaohua

    2016-09-20

    Mucosal immune system plays a very important role in antiviral immune response. We prepared Newcastle disease viruses (NDV) encapsulated in N-2-hydroxypropyl trimethyl ammonium chloride chitosan (N-2-HACC) nanoparticles (NDV/La Sota-N-2-HACC-NPs) by an ionic cross linking method, and assessed the potential of N-2-HACC-NPs as a mucosal immune delivery carrier. The properties of the nanoparticles were determined by transmission electron microscopy, Zeta potential and particle size analysis, encapsulation efficiency and loading capacity. NDV/La Sota-N-2-HACC-NPs have regular spherical morphologies and high stability; with 303.88±49.8nm mean diameter, 45.77±0.75mV Zeta potential, 94.26±0.42% encapsulation efficiency and 54.06±0.21% loading capacity. In vitro release assay indicated that the release of NDV from NDV/La Sota-N-2-HACC-NPs is slow. The NDV/La Sota-N-2-HACC-NPs have good biological characteristics, very low toxicity and high level of safety. Additionally, specific pathogen-free chickens immunized with NDV/La Sota-N-2-HACC-NPs showed much stronger cellular, humoral and mucosal immune responses than commercial attenuated live Newcastle disease vaccine, and NDV/La Sota-N-2-HACC-NPs reached the sustainable release effect. Our study here provides a foundation for the further development of mucosal vaccines and drugs, and the N-2-HACC-NPs should be a potential drug delivery carrier with immense potential in medical applications. PMID:27261727

  5. Optimization of structural and dielectric properties of CdSe loaded poly(diallyl dimethyl ammonium chloride) polymer in a desired frequency and temperature window

    Energy Technology Data Exchange (ETDEWEB)

    Tyagi, Chetna, E-mail: ctyagi05@gmail.com; Sharma, Ambika, E-mail: ambikasharma2004@yahoo.com [Department of Applied Sciences, The NorthCap University (Formerly ITM University), Gurgaon, 122017 Haryana (India)

    2016-01-07

    In the present paper, investigations of CdSe loaded poly(diallyl dimethyl ammonium chloride) (PDADMAC) nanocomposites and pure PDADMAC synthesized by wet chemical technique have been carried out. Fourier transform infrared and X-ray diffraction analysis have been performed to reveal the structural details of pure polymer and polymer nanocomposite (PNC). The dielectric behavior of pure polymer and PNC has been recorded, which results in higher value of the real and imaginary part of dielectric constant for PNC, as compared with pure PDADMAC. The increase is attributed to the addition of CdSe quantum dots to the pure polymer. The contribution of ionic and electronic polarization has been observed at higher frequency. The theoretical fitting of Cole-Cole function to the experimental data of dielectric constant of PNC and pure PDADMAC results in the determination of relaxation time and conductivity of space charge carriers. The CdSe loaded polymer nanocomposite has been used as an electrolyte in the battery fabrication with configuration Al/PNC/Ag{sub 2}O. The ac conductivity measurements have been carried out for both samples in a frequency window of 1 kHz–5 MHz and at different temperatures varying from 298 K to 523 K. Activation energy (E{sub a}) has been determined for pure polymer as well as PNC and is found to be less for PNC, as compared with pure polymer. Further, impedance measurement at different temperatures results in two frequency ranges corresponding to ionic conduction and blocking electrode effect. The value of bulk resistance for pure polymer and PNC has been found to be 3660 Ω and 442 Ω, respectively, at 298 K temperature. Electric modulus has been determined and is observed to support the dielectric constant data; it further reveals the deviation from Debye behavior at a higher frequency.

  6. Optimization of structural and dielectric properties of CdSe loaded poly(diallyl dimethyl ammonium chloride) polymer in a desired frequency and temperature window

    Science.gov (United States)

    Tyagi, Chetna; Sharma, Ambika

    2016-01-01

    In the present paper, investigations of CdSe loaded poly(diallyl dimethyl ammonium chloride) (PDADMAC) nanocomposites and pure PDADMAC synthesized by wet chemical technique have been carried out. Fourier transform infrared and X-ray diffraction analysis have been performed to reveal the structural details of pure polymer and polymer nanocomposite (PNC). The dielectric behavior of pure polymer and PNC has been recorded, which results in higher value of the real and imaginary part of dielectric constant for PNC, as compared with pure PDADMAC. The increase is attributed to the addition of CdSe quantum dots to the pure polymer. The contribution of ionic and electronic polarization has been observed at higher frequency. The theoretical fitting of Cole-Cole function to the experimental data of dielectric constant of PNC and pure PDADMAC results in the determination of relaxation time and conductivity of space charge carriers. The CdSe loaded polymer nanocomposite has been used as an electrolyte in the battery fabrication with configuration Al/PNC/Ag2O. The ac conductivity measurements have been carried out for both samples in a frequency window of 1 kHz-5 MHz and at different temperatures varying from 298 K to 523 K. Activation energy (Ea) has been determined for pure polymer as well as PNC and is found to be less for PNC, as compared with pure polymer. Further, impedance measurement at different temperatures results in two frequency ranges corresponding to ionic conduction and blocking electrode effect. The value of bulk resistance for pure polymer and PNC has been found to be 3660 Ω and 442 Ω, respectively, at 298 K temperature. Electric modulus has been determined and is observed to support the dielectric constant data; it further reveals the deviation from Debye behavior at a higher frequency.

  7. An investigation into the use of cuprous chloride for the removal of radioactive iodide from aqueous solutions.

    Science.gov (United States)

    Liu, Yang; Gu, Ping; Jia, Lin; Zhang, Guanghui

    2016-01-25

    Cuprous chloride (CuCl) was examined as a precipitant to remove iodide (I(-)) from aqueous solutions. The effects of the dosage of CuCl, reaction time, initial concentrations of I(-) and bicarbonate (HCO3(-)) on I(-) removal were investigated. The results showed that the optimized removal efficiency of I(-) reached approximately 95.8% when the dosage was 150 mg/L, the initial I(-) concentration ranged from 5 to 40 mg/L and the reaction time was 15 min. The removal efficiency decreased from 95.8% to 76.0% with the addition of HCO3(-) at a concentration in the range of 0-107 mg/L. Furthermore, the dissociation of CuCl, the disproportionation reaction of Cu(+), the precipitation of cuprous iodide (CuI) and cuprous oxide (Cu2O), and the formations of copper sulfide (CuxS, 1≤xradioactive I(-) pollution in water.

  8. The phosphine oxides Cyanex 921 and Cyanex 923 as carriers for facilitated transport of chromium (VI)-chloride aqueous solutions.

    Science.gov (United States)

    Alguacil, Francisco José; López-Delgado, Aurora; Alonso, Manuel; Sastre, Ana Maria

    2004-11-01

    The behaviour of the phosphine oxides Cyanex 921 and Cyanex 923 in the facilitated transport of chromium (VI) from chloride solutions is described. Transport is studied as a function of several variables such as stirring speeds of the aqueous phases, membrane phase diluent, hydrochloric acid concentration in the source phase and chromium and carrier concentrations. The separation of chromium (VI) from other metals presented in the source phase as well as the behaviour of phosphine oxides with respect to other neutral organophosphorous derivatives (tri-n-butylphosphate (TBP) and dibutyl butylphosphonate (DBBP)) are also investigated. Moreover, by using hydrazine sulphate in the receiving phase, Cr(VI) is immediately reduced to the less toxic Cr(III).

  9. Sodium Chloride interaction with solvated and crystalline cellulose : sodium ion affects the tetramer and fibril in aqueous solution

    CERN Document Server

    Bellesia, Giovanni

    2013-01-01

    Inorganic salts are a natural component of biomass which have a significant effect on the product yields from a variety of biomass conversion processes. Understanding their effect on biomass at the microscopic level can help discover their mechanistic role. We present a study of the effect of aqueous sodium chloride (NaCl) on the largest component of biomass, cellulose, focused on the thermodynamic and structural effect of a sodium ion on the cellulose tetramer, and fibril. Replica exchange molecular dynamics simulations of a cellulose tetramer reveal a number of preferred cellulose-Na contacts and bridging positions. Large scale MD simulations on a model cellulose fibril find that Na+ perturbs the hydroxymethyl rotational state population and consequently disrupts the "native" hydrogen bonding network.

  10. Structural transformations of the synthetic salt 4`, 7-dihydroxyflavylium chloride in acid and basic aqueous solutions. Part 1-Ground state

    Energy Technology Data Exchange (ETDEWEB)

    Pina, F.; Benedito, L.; Melo, M.J.; Parola, A.J. [Centro de Quimica Fina e Biotecnologia. Departamento de Quimica FCT/UNL, Portugal (Portugal); Lima, J.C.; Macanita, A.L. [Instituto de Tecnologia Quimica e Biologica, Portugal (Portugal)

    1997-09-01

    A complete study of the structural pH dependent transformations of the synthetic flavylium salt 4`-7-dihydroxyflavylium chloride (DHF), occurring in aqueous solutions, including the basic region, is described. The kinetics study of the transformations occurring in acidic media (quinoidal base (A) {l_reversible} flavylium cation (AH{sup +}) {l_reversible} hemiacetal (B) {l_reversible} cis-chalcone (C-cis) {l_reversible} trans-chalcone (C-trans)) allowed to conclude that the cis-transisomerization is faster than the tautomerization and the hydration processes, which is unique in the anthocyanins family. Results obtained with the parent compound 4`-7-dimethoxyflavylium chloride (DMF)with relevance to this study are also presented. In equilibrated basic solutions the existence of acid-base equilibria involving the trans-Chalcone (C-trans) and its conjugated bases, (C-trans, and C``2-trans), was detected. Freshly prepared solutions at pH>7 show also the presence of a transient species identified as the ionized quinoidal base (A``-), which is almost completely converted into C``2-trans with a Ph dependent rate constant, (Author) 17 refs.

  11. Anodic behaviour of the stainless steel AISI 430 in aqueous solutions of chloride and sulphate ions

    International Nuclear Information System (INIS)

    The kinetics of the dissolution of stainless steel AISI 430 in the presence of chloride and sulphate ions has been studied in terms of the ion concentration, the pH variation, and the velocity of the working electrode. The experimental method utilized was the potentiostatic anodic polarization, and the reactants used were NaCl and Na2 SO4 at room temperature. Atomic Absorption spectrophotometry and Auger Electrons spectroscopy (AES) analyses were made in order to support the interpretation of results obtained by means of the potentiostatic polarization method. (author)

  12. Effects of the protein denaturant guanidinium chloride on aqueous hydrophobic contact-pair interactions.

    Science.gov (United States)

    Macdonald, Ryan D; Khajehpour, Mazdak

    2015-01-01

    Guanidinium chloride (GdmCl) is one of the most common protein denaturants. Although GdmCl is well known in the field of protein folding, the mechanism by which it denatures proteins is not well understood. In fact, there are few studies looking at its effects on hydrophobic interactions. In this work the effect of GdmCl on hydrophobic interactions has been studied by observing how the denaturant influences model systems of phenyl and alkyl hydrophobic contact pairs. Contact pair formation is monitored through the use of fluorescence spectroscopy, i.e., measuring the intrinsic phenol fluorescence being quenched by carboxylate ions. Hydrophobic interactions are isolated from other interactions through a previously developed methodology. The results show that GdmCl does not significantly affect hydrophobic interactions between small moieties such as methyl groups and phenol; while on the other hand, the interaction of larger hydrophobes such as hexyl and heptyl groups with phenol is significantly destabilized.

  13. Calix[4]arene based dipodal receptor nanohybrids for selective determination of chloride ions in aqueous media.

    Science.gov (United States)

    Kaur, Harpreet; Singh, Jasminder; Chopra, Shweta; Kaur, Navneet

    2016-01-01

    A chemical sensor based on p-tert butyl calix[4]arene has been synthesized and characterized using an assortment of spectroscopic techniques such as (1)H NMR, (13)C NMR, and elemental analysis. For sensor application, organic nanoparticles (N1) of 1 have been primed by implementing re-precipitation technique, which were further employed for preparing organic-inorganic hybrid (H1) by decorating N1 with gold nanoparticles. Both N1 and H1 were characterized using UV-visible, fluorescence, and DLS studies. Photo-physical changes due to anion binding with H1 were scrutinized using UV-visible absorption spectrometer and found it to promptly and selectively recognize Cl(-) ions in aqueous media. Thus, H1 can be effectively used for recognition of Cl(-) ions in aqueous media over a wide pH range, in samples of real time importance with a detection limit of 2.84×10(-9) M with a linear detection range up to 50 μM.

  14. Solubility of the Sodium and Ammonium Salts of Oxalic Acid in Water with Ammonium Sulfate.

    Science.gov (United States)

    Buttke, Lukas G; Schueller, Justin R; Pearson, Christian S; Beyer, Keith D

    2016-08-18

    The solubility of the sodium and ammonium salts of oxalic acid in water with ammonium sulfate present has been studied using differential scanning calorimetry, X-ray crystallography, and infrared spectroscopy. The crystals that form from aqueous mixtures of ammonium sulfate/sodium hydrogen oxalate were determined to be sodium hydrogen oxalate monohydrate under low ammonium sulfate conditions and ammonium hydrogen oxalate hemihydrate under high ammonium sulfate conditions. Crystals from aqueous mixtures of ammonium sulfate/sodium oxalate were determined to be ammonium oxalate monohydrate under moderate to high ammonium sulfate concentrations and sodium oxalate under low ammonium sulfate concentrations. It was also found that ammonium sulfate enhances the solubility of the sodium oxalate salts (salting in effect) and decreases the solubility of the ammonium oxalate salts (salting out effect). In addition, a partial phase diagram for the ammonium hydrogen oxalate/water system was determined. PMID:27482644

  15. SYNTHESIS AND CATALYTIC PROPERTIES OF HYDROPHOBICALLY-MODIFIED POLY(ALKYLMETHYLDIALLYLAMMONIUM CHLORIDES)

    NARCIS (Netherlands)

    Wang, G.J; Engberts, J.B.F.N.

    1995-01-01

    Novel non-cross-linked and cross-linked, hydrophobically modified homo- and copolymers were synthesized by free-radical cyclo(co)polymerization of alkylmethyldiallylammonium chloride monomers in aqueous solution using ammonium persulfate as the initiator. Cross-linking was brought about by addition

  16. Kinetic and equilibrium studies of the removal of ammonium ions from aqueous solution by rice husk ash-synthesized zeolite Y and powdered and granulated forms of mordenite

    International Nuclear Information System (INIS)

    The removal of ammonium from aqueous solutions using zeolite NaY prepared from a local agricultural waste, rice husk ash waste was investigated and a naturally occurring zeolite mordenite in powdered and granulated forms was used as comparison. Zeolite NaY and mordenite were well characterized by powder X-ray diffraction (XRD), energy dispersive X-ray (EDX) analysis and the total cation exchange capacity (CEC). CEC of the zeolites were measured as 3.15, 1.46 and 1.34 meq g-1 for zeolite Y, powdered mordenite and granular mordenite, respectively. Adsorption kinetics and equilibrium data for the removal of NH4+ ions were examined by fitting the experimental data to various models. Kinetic studies showed that the adsorption followed a pseudo-second-order reaction. The equilibrium pattern fits well with the Langmuir isotherm compared to the other isotherms. The monolayer adsorption capacity for zeolite Y (42.37 mg/g) was found to be higher than that powdered mordenite (15.13 mg/g) and granular mordenite (14.56 mg/g). Thus, it can be concluded that the low cost and economical rice husk ash-synthesized zeolite NaY could be a better sorbent for ammonium removal due to its rapid adsorption rate and higher adsorption capacity compared to natural mordenite.

  17. Temperature- and pH-dependent aqueous-phase kinetics of the reactions of glyoxal and methylglyoxal with atmospheric amines and ammonium sulfate

    Science.gov (United States)

    Sedehi, Nahzaneen; Takano, Hiromi; Blasic, Vanessa A.; Sullivan, Kristin A.; De Haan, David O.

    2013-10-01

    Reactions of glyoxal (Glx) and methylglyoxal (MG) with primary amines and ammonium salts may produce brown carbon and N-containing oligomers in aqueous aerosol. 1H NMR monitoring of reactant losses and product appearance in bulk aqueous reactions were used to derive rate constants and quantify competing reaction pathways as a function of pH and temperature. Glx + ammonium sulfate (AS) and amine reactions generate products containing C-N bonds, with rates depending directly on pH: rate = (70 ± 60) M-1 s-1fAld [Glx]totfAm [Am]tot, where fAld is the fraction of aldehyde with a dehydrated aldehyde functional group, and fAm is the fraction of amine or ammonia that is deprotonated at a given pH. MG + amine reactions generate mostly aldol condensation products and exhibit less pH dependence: rate = 10[(0.36 ± 0.06) × pH - (3.6 ± 0.3)] M-1 s-1fAld [MG]tot [Am]tot. Aldehyde + AS reactions are less temperature-dependent (Ea = 18 ± 8 kJ mol-1) than corresponding amine reactions (Ea = 50 ± 11 kJ mol-1). Using aerosol concentrations of [OH] = 10-12 M, [amine]tot = [AS] = 0.1 M, fGlx = 0.046 and fMG = 0.09, we estimate that OH radical reactions are normally the major aerosol-phase sink for both dicarbonyl compounds. However, reactions with AS and amines together can account for up to 12 and 45% of daytime aerosol-phase glyoxal and methylglyoxal reactivity, respectively, in marine aerosol at pH 5.5. Reactions with AS and amines become less important in acidic or non-marine aerosol, but may still be significant atmospheric sources of brown carbon, imidazoles, and nitrogen-containing oligomers.

  18. Removal of blue 1 dye of aqueous solutions with a modified clay with iron chloride

    International Nuclear Information System (INIS)

    At the present time, several technologies have been proposed to remove dyes from water, adsorption is one of the most feasible methods and adsorbents with different properties, such as activated carbon, zeolites, clays and hydrogels among others. In this work, the sorption behavior of blue 1 dye by a natural clay from a site located in the Center-East of Mexico, and other modified with iron chloride were determined. The materials were characterized by X-ray diffraction to analyze its crystal structure, by scanning electron microscopy and elemental microanalysis of energy dispersive X-ray spectrometry to determine the composition and morphology, and the zero point charges were also determined to know the charge distribution on the surface of the clay. The ph effect, contact time, dye concentration and temperature were the parameters considered in this study. The results showed that clay does not suffer any important changes in its structure after the chemical treatments (modification with ferric chloride and contact with blue 1 solutions). The ph influences lightly the adsorption of the dye with natural clay, but the same effect is not observed in the ferric modified clay among the factor ph 6 and 8. The equilibrium time and the sorption capacity for natural clay were 48 hours and 6.16 mg/g, while for the ferric clay were 24 hours and 14.22 mg/g. Adsorption kinetics results were best adjusted to the pseudo first and pseudo second order models. Adsorption isotherms were best adjusted to the Langmuir model, indicating that both clays have a homogeneous surface. Thermodynamic parameters (E, ΔS and ΔG and ΔH) were calculated for the dye adsorption by the natural clay using data of the adsorption kinetics at temperatures between 20 and 50 C, indicating that the adsorption process is exothermic. For the case of ferric clay, it was not possible to calculate these thermodynamic parameters because the adsorption capacities were similar in the range of selected

  19. A Fiber-Optic Sensor Using an Aqueous Solution of Sodium Chloride to Measure Temperature and Water Level Simultaneously

    Science.gov (United States)

    Yoo, Wook Jae; Sim, Hyeok In; Shin, Sang Hun; Jang, Kyoung Won; Cho, Seunghyun; Moon, Joo Hyun; Lee, Bongsoo

    2014-01-01

    A fiber-optic sensor system using a multiplexed array of sensing probes based on an aqueous solution of sodium chloride (NaCl solution) and an optical time-domain reflectometer (OTDR) for simultaneous measurement of temperature and water level is proposed. By changing the temperature, the refractive index of the NaCl solution is varied and Fresnel reflection arising at the interface between the distal end of optical fiber and the NaCl solution is then also changed. We measured the modified optical power of the light reflected from the sensing probe using a portable OTDR device and also obtained the relationship between the temperature of water and the optical power. In this study, the water level was simply determined by measuring the signal difference of the optical power due to the temperature difference of individual sensing probes placed inside and outside of the water. In conclusion, we demonstrate that the temperature and water level can be obtained simultaneously by measuring optical powers of light reflected from sensing probes based on the NaCl solution. It is anticipated that the proposed fiber-optic sensor system makes it possible to remotely monitor the real-time change of temperature and water level of the spent fuel pool during a loss of power accident. PMID:25310471

  20. Removal of malachite green dye from aqueous solution using mesoporous silica synthesized from 1-octyl-3-methylimidazolium chloride ionic liquid

    Science.gov (United States)

    Ekka, Basanti; Nayak, Soumitra Ranjan; Dash, Priyabrat; Patel, Raj Kishore

    2016-04-01

    In this research, mesoporous silica was synthesized via a modified sol-gel route using 1-octyl-3-methylimidazolium chloride and was employed to remove malachite green (MG) dye from aqueous solution. Subsequently, this material was characterized and identified by different techniques such as Fourier transform infrared spectroscopy (FT-IR), N2 adsorption-desorption method, scanning electron microscopy (SEM), and thermosgravimetric analysis (TGA). Unique properties such as high surface area and pore diameter, in addition to highly reactive atoms and presence of various functional groups make the mesoporous silica possible for efficient removal of malachite green (MG). In batch experimental set-up, optimum conditions for quantitative removal of MG by mesoporous silica was attained by varying different variables such as adsorbent dosage, initial dye concentration, contact time, and pH. Optimum values were set as pH of 8.0, 0.5 g of adsorbent at contact time of 120 min. The adsorption of MG follows the pseudo-second-order rate equation. Equilibrium data fitted well with the Freundlich model at all amount of adsorbent, while maximum adsorption capacity was 5.981 mg g-1 for 0.5 g mesoporous silica synthesized in IL.

  1. Role of Citrate Ions in the Phosphonate-based Inhibitor System for Mild Steel in Aqueous Chloride Media

    Directory of Open Access Journals (Sweden)

    G. Gunasekaran

    2005-01-01

    Full Text Available The corrosion inhibition efficiency of phosphonic acid and its derivatives for the inhibition of corrosion of mild steel in neutral chloride media is decided by its ability to form protectivefilm over the surface. In this context, the effect of addition of metal cations and certain organic compounds, such as citrate in conjugation with phosphonic acid to impart synergistic corrosion inhibition has been explored. The experiments were carried out using various concentrations of trisodium citrate and zinc ions in an aqueous solution of 2-carboxyethyl phosphonic acid (2CEPA at 25 ppm. The corrosion characteristics have been determined using electrochemical impedance spectroscopy together with determination of corrosion rate by weight-loss method. It has been observed that a combination of inhibitive ions, namely citrate, ZCEPA, and zinc ions at 25 ppm gives 96 per cent inhibition efficiency and this corrosion inhibition is due to the formation of a protective film. By increasing the concentration of citrate beyond 25 ppm, the corrosion inhibition efficiency decreases. This paper discusses the role of citrate and zinc ions in imparting added corrosion inhibition ability using 2CEPA on the basis of experimental results.

  2. A Fiber-Optic Sensor Using an Aqueous Solution of Sodium Chloride to Measure Temperature and Water Level Simultaneously

    Directory of Open Access Journals (Sweden)

    Wook Jae Yoo

    2014-10-01

    Full Text Available A fiber-optic sensor system using a multiplexed array of sensing probes based on an aqueous solution of sodium chloride (NaCl solution and an optical time-domain reflectometer (OTDR for simultaneous measurement of temperature and water level is proposed. By changing the temperature, the refractive index of the NaCl solution is varied and Fresnel reflection arising at the interface between the distal end of optical fiber and the NaCl solution is then also changed. We measured the modified optical power of the light reflected from the sensing probe using a portable OTDR device and also obtained the relationship between the temperature of water and the optical power. In this study, the water level was simply determined by measuring the signal difference of the optical power due to the temperature difference of individual sensing probes placed inside and outside of the water. In conclusion, we demonstrate that the temperature and water level can be obtained simultaneously by measuring optical powers of light reflected from sensing probes based on the NaCl solution. It is anticipated that the proposed fiber-optic sensor system makes it possible to remotely monitor the real-time change of temperature and water level of the spent fuel pool during a loss of power accident.

  3. Modeling phase equilibria of semiclathrate hydrates of CH4, CO2 and N2 in aqueous solution of tetra-(n)-butyl ammonium bromide

    Institute of Scientific and Technical Information of China (English)

    Abhishek Joshi; Prathyusha Mekala; Jitendra S.Sangwai

    2012-01-01

    Semiclathrate hydrates of tetra-(n)-butyl ammonium bromide (TBAB) offer potential solution for gas storage,transportation,separation of flue gases and CO2 sequestration.Models for phase equilibria for these systems have not yet been developed in open literatures and thus require urgent attention.In this work,the first attempt has been made to model phase equilibria of semiclathrate hydrates of CH4,CO2 and N2 in aqueous solution of TBAB.A thermodynamic model for gas hydrate system as proposed by Chen and Guo has been extended for semiclathrate hydrates of gases in aqueous solution of TBAB.A correlation for the activity of water relating to the system temperature,concentration of TBAB in the system and the nature of guest gas molecule has been proposed.The model results have been validated against available experimental data on phase equilibria of semiclathrate hydrate systems of aqueous TBAB with different gases as guest molecule.The extended Chen and Guo's model is found to be suitable to explain the promotion effect of TBAB for the studied gaseous system such as,methane,carbon dioxide and nitrogen as a guest molecule.Additionally,a correlation for the increase in equilibrium formation temperature (hydrate promotion temperature,△Tp) of semiclathrate hydrate system with respect to pure gas hydrate system has been developed and applied to semiclathrate hydrate of TBAB with several gases as guest molecules.The developed correlation is found to predict the promotion effect satisfactorily for the system studied.

  4. Effects of reactive oxygen and nitrogen species induced by ammonium dinitramide decomposition in aqueous solutions of deoxyribose nucleic acid.

    Science.gov (United States)

    Steel-Goodwin, L; Kuhlman, K J; Miller, C; Pace, M D; Carmichael, A J

    1997-01-01

    Ammonium dinitramide (ADN), a potential rocket fuel, decomposes in water forming NO2. The chemistry of this ADN-released NO2 in oxygenated biological systems is complex both in the number of potential chemical species and in the number of parallel and consecutive reactions that can theoretically occur. High-pressure liquid chromatography (HPLC) studies revealed ADN fragmented deoxyribose nucleic acid (DNA). Damage to DNA standard solutions was caused by at least two major pathways, one arising from reactions of NO2 with oxygen and one arising from a reaction with superoxide (O2-.). The radical species generated when ADN is incubated with standard solutions of DNA, pH 7.5, in the presence of the spin trap agent n-tert-butyl-alpha-nitrone (PBN) was compared with the PBN-radical adducts generated in the presence of ADN and O2-. or of ADN and hydrogen peroxide (H2O2). The ADN-induced PBN radical adducts increased linearly over the 90-minute study period. The values of peak intensity in the presence of O2-. and in the presence of H2O2, were 828% and 7.08%, respectively, of the ADN-induced radicals alone. The synergistic effect of ADN with O2- may provide an understanding of the sensitivity of the rat blastocyst to aDN at the preimplantation stage of development and the lack of toxicity in in vivo studies in tissues high in catalase. PMID:9142377

  5. Adsorption of chromium(VI) from aqueous solutions by glycidylmethacrylate-grafted-densified cellulose with quaternary ammonium groups

    Science.gov (United States)

    Anirudhan, T. S.; Nima, J.; Divya, P. L.

    2013-08-01

    This study successfully synthesized a new adsorbent by ethylation of glycidylmethacrylate grafted aminated titanium dioxide densified cellulose (Et-AMPGDC), to remove chromium(VI) from aqueous solutions. The adsorbent was characterized by the FTIR, XRD, SEM and TG-DTG measurements. Batch adsorption technique using Et-AMPGDC was applied for the removal of Cr(VI) from aqueous solution and waste water. The contact time necessary to attain equilibrium and the optimum pH were found to be 1 h and 4.5, respectively. The kinetics of sorption of Cr(VI) ions was described by a pseudo-second-order kinetic model. The equilibrium isotherm data were analyzed using the Langmuir and Freundlich isotherm equations and the adsorption process was reflected by Langmuir isotherm. The maximum adsorption capacity was evaluated to be 123.60 mg/g. The electroplating industrial wastewater samples were treated with Et-AMPGDC to demonstrate its efficiency in removing Cr(VI) from wastewater. Almost complete removal was possible with 100 mg of the adsorbent from 50 mL of wastewater sample. Desorption efficiency was achieved by treatment with 0.1 M NaOH and five adsorption-desorption cycles were performed without significant decrease in adsorption capacity.

  6. Precipitation of gold by the reaction of aqueous gold(III)-chloride with cyanobacteria at 25-80 C -- Studied by x-ray absorption spectroscopy

    International Nuclear Information System (INIS)

    The mechanisms of gold precipitation by the interaction of cyanobacteria (Plectonema boryanum UTEX 485) and gold(III) chloride aqueous solutions (7.6 mmol/L final gold) have been studied at 25, 60, and 80 C, using both laboratory and real-time synchrotron radiation absorption spectroscopy experiments. Addition of aqueous gold(III) chloride to the cyanobacterial culture initially promoted the precipitation of amorphous gold(I) sulfide at the cell walls and finally caused the formation of octahedral (111) platelets (<1 to 6 (micro)m) of gold metal near cell surfaces and in solutions. X-ray absorption spectroscopy results confirmed that the reduction mechanism of gold(III) chloride to elemental gold by cyanobacteria involves the formation of an intermediate Au(I) species, gold(I) sulfide, with sulfur originating from cyanobacterial proteins, presumably cysteine or methionine. Although the bioreduction of gold(III) chloride to gold(I) sulfide was relatively rapid at all temperatures, the reaction rate increased with the increase in temperature. At the completion of the experiments, elemental gold was the major species present at all temperatures

  7. 2-羟丙基三甲基氯化铵壳聚糖的制备及其抗菌性分析%Characterization and Antimicrobial Activity of 2-Hydroxypropyltrimethyl Ammonium Chloride Chitosan

    Institute of Scientific and Technical Information of China (English)

    龚安华; 吴涛; 吴静; 钱琛

    2012-01-01

    The water-soluble quaternary ammonium salt of 2-hydroxypropyltrimethyl ammonium chloride chitosan (HTCC) was successfully prepared by the reaction of chitosan with 2, 3-epoxypropyl trimethyl ammonium chloride (CTA). The structure of HTCC was characterized by FTIR and 1H NMR, and in vitro antimicrobial activities of HTCC were investigated systematically. The results indicated that the non-woven fabrics which had been immersed in HTCC solution demonstrated good antimicrobial activity against Escherichia coli and Campylobacter jejuni. The minimum inhibitory concentration (MIC) of HTCC solution against C. Jejuni was 8 mg/mL. The results indicated that HTCC was a potential polymeric antimicrobial.%以2,3-环氧丙基三甲基氯化铵(GTA)和壳聚糖为原料制备水溶性的壳聚糖季铵盐2-羟丙基三甲基氯化铵壳聚糖(HTCC),采用傅立叶红外光谱仪(FTIR谱图)和核磁共振仪(1H-NMR图谱)表征HTCC的结构,并进行抗菌性研究.结果表明,HTCC溶液和浸泡过HTCC的无纺布对大肠杆菌(Escherichia coli)和空肠弯曲菌(Campylobacter jejuni)有抑菌效果,其中对空肠弯曲菌的最低抑菌浓度(MIC)为8mg/mL,说明HTCC是一种具有应用潜力的高分子抗菌剂.

  8. Extraction of Caprolactam from Aqueous Ammonium Sulfate Solution in Pulsed Packed Column Using 250Y Mellapak Packings%在脉冲填料柱中萃取硫酸铵溶液中的己内酰胺

    Institute of Scientific and Technical Information of China (English)

    谢方友; 朱明乔; 刘建青; 何潮洪

    2002-01-01

    Liquid-liquid equilibrium (LLE) data of water-caprolactam-benzene-(NH4)2SO4 system at 303 K were measured for extraction of caprolactam from aqueous ammonium sulfate solution. The influence of fluid flow rate, pulsation intensity on flooding velocity and mass transfer was studied for extraction of caprolactam from ammonium sulfate solution in a laboratory pulsed packed column. The flooding velocities and overall apparent height of a transfer unit were given under various operation conditions. An industrial column developed based on above study is operated well. The scale-up effect is discussed.

  9. Ion-pair formation in aqueous strontium chloride and strontium hydroxide solutions under hydrothermal conditions by AC conductivity measurements.

    Science.gov (United States)

    Arcis, H; Zimmerman, G H; Tremaine, P R

    2014-09-01

    Frequency-dependent electrical conductivities of solutions of aqueous strontium hydroxide and strontium chloride have been measured from T = 295 K to T = 625 K at p = 20 MPa, over a very wide range of ionic strength (3 × 10(-5) to 0.2 mol kg(-1)), using a high-precision flow AC conductivity instrument. Experimental values for the concentration-dependent equivalent conductivity, Λ, of the two electrolytes were fitted with the Turq-Blum-Bernard-Kunz ("TBBK") ionic conductivity model, to determine ionic association constants, K(A,m). The TBBK fits yielded statistically significant formation constants for the species SrOH(+) and SrCl(+) at all temperatures, and for Sr(OH)2(0) and SrCl2(0) at temperatures above 446 K. The first and second stepwise association constants for the ion pairs followed the order K(A1)(SrOH(+)) > K(A1)(SrCl(+)) > K(A2)[Sr(OH)2(0)] > K(A2)[SrCl2(0)], consistent with long-range solvent polarization effects associated with the lower static dielectric constant and high compressibility of water at elevated temperatures. The stepwise association constants to form SrCl(+) agree with previously reported values for CaCl(+) to within the combined experimental error at high temperatures and, at temperatures below ∼375 K, the values of log10 KA1 for strontium are lower than those for calcium by up to ∼0.3-0.4 units. The association constants for the species SrOH(+) and Sr(OH)2(0) are the first accurate values to be reported for hydroxide ion pairs with any divalent cation under these conditions.

  10. The adsorption of alkyl-dimethyl-benzyl-ammonium chloride onto cotton nonwoven hydroentangled substrates at the solid-liquid interface is minimized by additive chemistries

    Science.gov (United States)

    Quaternary ammonium compounds, commonly referred to as quats, are cationic surfactants widely used as the active biocide ingredient for disposable disinfecting wipes. The cationic nature of quats results in a strong ionic interaction and adsorption onto wipes materials that have an anionic surface ...

  11. Temperature-Induced Aggregate Transitions in Mixtures of Cationic Ammonium Gemini Surfactant with Anionic Glutamic Acid Surfactant in Aqueous Solution.

    Science.gov (United States)

    Ji, Xiuling; Tian, Maozhang; Wang, Yilin

    2016-02-01

    The aggregation behaviors of the mixtures of cationic gemini surfactant 1,4-bis(dodecyl-N,N-dimethylammonium bromide)-2,3-butanediol (C12C4(OH)2C12Br2) and anionic amino acid surfactant N-dodecanoylglutamic acid (C12Glu) in aqueous solution of pH = 10.0 have been studied. The mixture forms spherical micelles, vesicles, and wormlike micelles at 25 °C by changing mixing ratios and/or total surfactant concentration. Then these aggregates undergo a series of transitions upon increasing the temperature. Smaller spherical micelles transfer into larger vesicles, vesicles transfer into solid spherical aggregates and then into larger irregular aggregates, and entangled wormlike micelles transfer into branched wormlike micelles. Moreover, the larger irregular aggregates and branched micelles finally lead to precipitation and clouding phenomenon, respectively. All these transitions are thermally reversible, and the transition temperatures can be tuned by varying the mixing ratios and/or total concentration. These temperature-dependent aggregate transitions can be elucidated on the basis of the temperature-induced variations in the dehydration, electrostatic interaction, and hydrogen bonds of the headgroup area and in the hydrophobic interaction between the hydrocarbon chains. The results suggest that the surfactants carrying multiple binding sites will greatly improve the regulation ability and temperature sensitivity. PMID:26750978

  12. Evaluation of aqueous and alcohol-based quaternary ammonium sanitizers for inactivating Salmonella spp., Escherichia coli O157:H7, and Listeria monocytogenes on peanut and pistachio shells.

    Science.gov (United States)

    McEgan, Rachel; Danyluk, Michelle D

    2015-05-01

    This study evaluated the efficacy of aqueous (aQUAT) and isopropyl alcohol-based quaternary ammonium (ipQUAT) sanitizers for reducing Salmonella spp., Escherichia coli O157:H7, or Listeria monocytogenes populations on peanut and pistachio shell pieces. Inoculated nutshells were mixed with QUAT sanitizers, water, or 70% ethanol and enumerated immediately or after incubation at 30 °C for 48 h. None of the treatments had any immediate effect on Salmonella or E. coli O157:H7 populations on the peanut or pistachio shells. L. monocytogenes populations declined immediately on the peanut and pistachio shells treated with aQUAT or ipQUAT. After incubation, Salmonella and E. coli O157:H7 populations increased significantly on the water- or aQUAT-treated peanut and pistachio shells. L. monocytogenes populations also increased significantly on the water- or aQUAT-treated peanut shells, but levels did not change on the water-treated pistachio shells and levels were just above the limit of detection on the aQUAT-treated pistachio shells. After treatment with ipQUAT and 48-h incubation, Salmonella and E. coli O157:H7 populations decreased to or below the limit of detection on both shell types; L. monocytogenes populations remained at or below the limit of detection on both shell types.

  13. Cr(VI) sorption behavior from aqueous solutions onto polymeric microcapsules containing a long-chain quaternary ammonium salt: Kinetics and thermodynamics analysis

    Energy Technology Data Exchange (ETDEWEB)

    Barassi, Giancarlo; Valdes, Andrea; Araneda, Claudio; Basualto, Carlos; Sapag, Jaime; Tapia, Cristian [Laboratorio de Operaciones Unitarias, Facultad de Ciencias Quimicas y Farmaceuticas, Universidad de Chile, Av. Vicuna Mackenna 20, Santiago (Chile); Valenzuela, Fernando, E-mail: fvalenzu@uchile.cl [Laboratorio de Operaciones Unitarias, Facultad de Ciencias Quimicas y Farmaceuticas, Universidad de Chile, Av. Vicuna Mackenna 20, Santiago (Chile)

    2009-12-15

    This work studies the adsorption of Cr(VI) ions from an aqueous acid solution on hydrophobic polymeric microcapsules containing a long-chain quaternary ammonium salt-type extractant immobilized in their pore structure. The microcapsules were synthesized by adding the extractant Aliquat 336 during the in situ radical copolymerization of the monomers styrene (ST) and ethylene glycol dimethacrylate (EGDMA). The microcapsules, which had a spherical shape with a rough surface, behaved as efficient adsorbents for Cr(VI) at the tested temperatures. The results of kinetics experiments carried out at different temperatures showed that the adsorption process fits well to a pseudo-second-order with an activation energy of 82.7 kJ mol{sup -1}, confirming that the sorption process is controlled by a chemisorption mechanism. Langmuir's isotherms were found to represent well the experimentally observed sorption data. Thermodynamics parameters, namely, changes in standard free energy ({Delta}G{sup 0}), enthalpy ({Delta}H{sup 0}), and entropy ({Delta}S{sup 0}), are also calculated. The results indicate that the chemisorption process is spontaneous and exothermic. The entropy change value measured in this study shows that metal adsorbed on microcapsules leads to a less chaotic system than a liquid-liquid extraction system.

  14. 氯化铵对泌乳奶牛生产性能及血尿代谢的影响%Effects of Ammonium Chloride on Performance, Serum and Urine Metabolism of Lactating Cows

    Institute of Scientific and Technical Information of China (English)

    王坤; 赵圃毅; 刘威; 卜登攀; 刘士杰; 张开展

    2016-01-01

    The present study evaluated the effects of ammonium chloride on performance, serum and urine me⁃tabolism of lactating cows to determine the optimal supplemental level for lactating dairy cows. Forty⁃eight Hol⁃stein dairy cows, similarly in days in milk, body weight, milk yield and parity, were randomly assigned to 1 of 4 groups with 12 cows according to a completely randomized design. The supplemental level of ammonium chloride was 0 ( control) , 150, 300 and 450 g/d, respectively. The pre⁃trial lasted for 14 days and the trial lasted 56 days. The results showed as follows:1) dry matter intake ( P=0.012) and milk yield ( P=0.008) decreased linearly as the supplemental level of ammonium chloride increased, and 300 and 450 g/d groups were significantly lower than control group (P0.05) , while milk protein percentage tended to be linearly increased ( P=0.094). 2) Urine pH decreased quadratically as ammonium chloride supplemental level increased ( P =0.012), and 300 and 450 g/d groups were significantly lower than control group (P<0.05); the concentra⁃tions of serum Cl-(P=0.002) and urine Cl-(P=0.004), Ca2+(P<0.001), P5+(P=0.017) and Mg2+(P=0.048) increased linearly as the supplemental level of ammonium chloride increased. 3) Serum urea concentra⁃tion increased linearly as ammonium chloride supplemental level increased ( P=0.018) , and 300 and 450 g/d groups were significantly higher than control group ( P<0.05) . In conclusion, ammonium chloride supplemen⁃tal level of lactating dairy cows should not exceed 300 g/d, and a more appropriate supplemental level is 150 g/d.%本试验通过探究饲粮添加不同水平的氯化铵对泌乳奶牛生产性能及血尿代谢的影响,旨在确定氯化铵在泌乳奶牛饲粮中的适宜添加量。采用完全随机设计,将48头泌乳日龄、体重、胎次及产奶量相近的中国荷斯坦奶牛随机分为4组,每组12头,各组氯化铵添加量分别为每头牛0(对照)、150、300和450 g

  15. Manufacture and research of acrylamide-methyl acryloyl oxygen ethyl trimethyl ammonium chloride copolymer%丙烯酰胺-甲基丙烯酰氧乙基三甲基氯化铵共聚物的制备研究

    Institute of Scientific and Technical Information of China (English)

    钱涛; 李梦耀; 马岚; 王莹; 张晓松

    2014-01-01

    Using ammonium persulfate( KPS )trigger with methacryloyl ethyl trimethyl ammonium chlo-ride( DMC)and acrylamide( AM)in a single aqueous phase to prepare a cationic polyacrylamide lactic flocculent(CPAM)and used in the wastewater. Discussing about total monomer,initiator dosage,pH,reaction time and other factors affect the intrinsic viscosity and viscosity-average molecular weight of polymer. The results show that P( DMC-AM)viscosity-average molecular weight can be up to 1. 72 × 107 g/mol, the effluent turbidity removal rate reached more than 80%,the product is a kind of flocculant of excel-lent performance.%用过硫酸铵( KPS)引发甲基丙烯酰氧乙基三甲基氯化铵( DMC)与丙烯酰胺( AM)单水相共聚,制备了阳离子聚丙烯酰胺类絮凝剂P( DMC-AM),并应用于废水。探讨了单体总量、引发剂用量、pH值、反应时间等因素对聚合物的特性粘数和粘均分子量的影响。结果表明,P(DMC-AM)粘均分子量可达1.72×107 g/mol,对废水浊度的去除率达到80%以上,是一种性能优良的絮凝剂。

  16. Study on aqueous two-phase systems of the mixture SDS/CTAB surfactants

    Institute of Scientific and Technical Information of China (English)

    LI Ying; CHEN Yah-ming; ZHAO Kong-shuang; Takumi HIKIDA

    2004-01-01

    The phenomenon of two dilute aqueous phases composed of sodium dodecylsulfate (SDS) and cetyltrimethyl ammonium bromide(CTAB) was investigated under various conditions such as concentrations and molarratios of the two surfactants, the addition of sodium chloride and temperature. Vesicles formation was found in theboth phases by TEM image.

  17. Efeito do dimetildioctadecilamônio na resposta imune humoral e celular de cobaios inoculados com o herpesvírus bovino-1 inativado Effect of dimethyl dioctadecyl ammonium chloride on the humoral and cellular response to inactivated bovine herpesvirus-1 in guinea pigs

    Directory of Open Access Journals (Sweden)

    L.C. Silva

    2004-06-01

    Full Text Available Avaliou-se o potencial adjuvante do cloreto de dimetildioctadecilamônio (DDA cloreto em estimular as respostas imune humoral e celular, do tipo hipersensibilidade cutânea tardia (DTH, em cobaios que receberam preparações de antígeno contendo o herpesvírus bovino tipo 1 (BHV-1 inativado. Os animais foram vacinados com o BHV-1 em cinco diferentes formulações, representadas pelos grupos: A- adjuvante completo / incompleto de Freund, B- hidróxido de alumínio (Al(OH3, C- DDA cloreto, D- associação Al(OH3 / DDA cloreto e E- BHV-1 em solução aquosa sem adjuvante. Os animais do grupo F, grupo-controle negativo, foram inoculados apenas com meio de cultivo celular. Os maiores títulos de anticorpos neutralizantes do BHV-1, expressos em log2, foram obtidos nos grupos D, A e C, com títulos de 6,25, 6,0 e 5,25, respectivamente. Na avaliação da DTH, os maiores aumentos na espessura da dobra da pele foram observados nos grupos A (2,4mm, C (1,8mm e D (1,1mm. O DDA cloreto, utilizado tanto de forma isolada quanto em associação, determinou a potencialização das respostas imunológicas humoral e celular de cobaios imunizados com o BHV-1 inativado.The adjuvanticity of dimethyl dioctadecyl ammonium chloride (DDA chloride to induce humoral and cell mediated (delayed type hypersensitivity - DTH - immune responses was assessed in guinea pigs that received antigen preparations containing inactivated bovine herpesvirus type 1 (BHV-1. The animals were vaccinated with five different formulations, containing BHV-1 represented by groups: A- complete/incomplete Freund adjuvant, B- aluminum hydroxide (Al(OH3, C- DDA chloride, D- association Al(OH3/DDA and E- BHV-1 in aqueous solution without adjuvant. Group F was the negative control group and the animals received only cell culture medium. The higher titers of BHV-1 neutralizing antibodies, expressed in log2, were obtained in groups D, A and C with values of 6.25, 6.0 and 5.25, respectively. In the DTH

  18. Complete dechlorination of 2,4-dichlorophenol in aqueous solution on palladium/polymeric pyrrole-cetyl trimethyl ammonium bromide/foam-nickel composite electrode

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Zhirong, E-mail: zrsun@bjut.edu.cn [College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124 (China); Wei, Xuefeng; Han, Yanbo; Tong, Shan [College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124 (China); Hu, Xiang, E-mail: huxiang99@163.com [College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029 (China)

    2013-01-15

    Highlights: ► Pd/PPy-CTAB/foam-Ni electrode with high surface area and low Pd content was prepared. ► The composite electrode was applied to dechlorination of 2,4-DCP in aqueous solution. ► Complete dechlorination of 2,4-DCP was achieved with higher current efficiency. ► Removal efficiency kept 100% after 10 times dechlorination on the stable electrode. ► The electrochemically reductive activation energy was 25.8 kJ mol{sup −1} in this system. -- Abstract: The electrochemically reductive dechlorination of 2,4-dichlorophenol (2,4-DCP) in aqueous solution on palladium/polymeric pyrrole-cetyl trimethyl ammonium bromide/foam-nickel electrode (Pd/PPy-CTAB/foam-Ni electrode) was investigated in this paper. Pd/PPy-CTAB/foam-Ni electrode was prepared and characterized by cyclic voltammetry (CV), scanning electron microscope (SEM), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) adsorption and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). The influences of some experimental factors such as the dechlorination current, dechlorination time and the initial pH on the removal efficiency and the current efficiency of 2,4-DCP dechlorination on Pd/PPy-CTAB/foam-Ni electrode were studied. Complete removal of 2,4-DCP was achieved and the current efficiency of 47.4% could be obtained under the conditions of the initial pH of 2.2, the dechlorination current of 5 mA and the dechlorination time of 50 min when the initial 2,4-DCP concentration was 100 mg L{sup −1}. The analysis of high performance liquid chromatography (HPLC) identified that the intermediate products were 2-chlorophenol (2-CP) and 4-chlorophenol (4-CP). The final products were mainly phenol. Its further reduction product cyclohexanone was also detected. The electrocatalytic dechlorination pathways of 2,4-DCP on Pd/PPy-CTAB/foam-Ni electrode were discussed. The stability of the electrode was favorable that it could keep dechlorination efficiency at 100% after having been reused

  19. Modification of an Iranian clinoptilolite nano-particles by hexadecyltrimethyl ammonium cationic surfactant and dithizone for removal of Pb(II) from aqueous solution.

    Science.gov (United States)

    Anari-Anaraki, Mostafa; Nezamzadeh-Ejhieh, Alireza

    2015-02-15

    Natural clinoptilolite tuff was mechanically converted to micro (MCP) and nano (NCP) particles. The MCP and NCP powders were respectively modified with hexadecyltrimethyl ammonium bromide (HDTMA) and dithizone (DTZ). The raw and modified samples were characterized by X-ray diffraction (XRD), Fourier transformation infra red (FT-IR), scanning electron microscope (SEM), transmission electron microscope (TEM) and thermogravimetry (TG) and used for the removal of Pb(II) from aqueous solution. The results confirm that both ion exchange and complexation processes are responsible for removal of Pb(II) cations in the modified samples, while Pb(II) cations were only removed via an ion exchange process by the raw clinoptilolite. In this sorbent, the anionic removal property of surfactant modified zeolites (SMZs) changed to cationic removal property by an additional modification step. The best removal efficiency was observed by NCP-HDTMA-DTZ at the following experimental conditions: C(Pb(II)): 800 mg L(-1), HDTMA dosage: 0.2 mol L(-1), DTZ dosage: 5 mmol L(-1), contact time of DTZ with NCP-HDTMA: 1800 min and contact time of the sorbent with Pb(II): 360 min. The NCP-HDTMA-DTZ sorbent showed good efficiency for the removal of lead in the presence of different multivalent cations. Adsorption isotherms of Pb(II) ions obey the Langmuir equation that indicate the monolayer sorption of Pb(II). The adsorption kinetics based on the pseudo-second-order rate equation indicates that the rate limiting step involving a chemical reaction. The negative ΔH and ΔG indicate an exothermic and spontaneous process. PMID:25460715

  20. 氯化钠-正丙醇-硫氰酸铵-水体系析相萃取分离和富集锡(Ⅳ)%Separation and enrichment of stannum (Ⅳ) by phase extraction in sodium chloride-1-propanol-ammonium thiocyanate-water system

    Institute of Scientific and Technical Information of China (English)

    李玉玲; 陈彬; 马万山

    2013-01-01

    The behavior and conditions for extraction separation and enrichment of stannum (Ⅳ) from other metal ions in sodium chloride-1-propanol-ammonium thiocyanate-water system were investigated.The results showed that 1-propanol aqueous solution could be well divided into two phases in presence of sodium chloride.During the phase separation process,[Sn(SCN)5~6] [(5~6)-4]-formed from stannum (Ⅳ) and ammonium thiocyanate could reacted with protonized 1-propanol of C3H7OH2 + to form associated complex of [Sn(SCN)5~6][C3 H7OH2]1-2,which could be fully extracted by 1-propanol phase.When acidity of the solution was fixed at pH 2.0,and the concentration of 1-propanol,ammonium thiocyanate and sodium chloride was 30%(V/V),0.09 mol/L and 0.17 g/mL,respectively,the extraction yield of stannum(Ⅳ) was more than 98.3%.Simultaneously,Fe(Ⅱ),Ni(Ⅱ),Pb(Ⅱ),Al (Ⅲ),Mg(Ⅱ),Mn(Ⅱ),Ce(Ⅲ),Cr(Ⅲ),Zn(Ⅱ),Ag(Ⅰ),Cd(Ⅱ)and V(V) could not be extracted,realizing the separation of stannum (Ⅳ) from these metal ions.The method has been applied to the separation and determination of stannum (Ⅳ) in Pb-Ca-Sn-Al alloy sample with recovery of 97.4% and relative standard deviation(n=7) of 2.1%.%研究了氯化钠-正丙醇-硫氰酸铵-水体系析相萃取分离和富集Sn(Ⅳ)的行为及与一些金属离子分离的条件.结果表明,氯化钠能使正丙醇的水溶液分成两相,在分相过程中,Sn(Ⅳ)和硫氰酸铵生成的[Sn(SCN)5~6][(5~6)-4]-与质子化正丙醇C3H7OH2+形成的缔合物[Sn (SCN)5~6][C3H7OH2]1-2能被正丙醇相完全萃取.固定溶液酸度为pH 2,当正丙醇、硫氰酸铵和氯化钠的浓度分别为30% (V/V)、0.09 mol/L和0.17 g/mL时,Sn(Ⅳ)的萃取率在98.3%以上,Fe(Ⅱ)、Ni(Ⅱ)、Pb(Ⅱ)、Al(Ⅲ)、Mg(Ⅱ)、Mn(Ⅱ)、Ce(Ⅲ)、Cr(Ⅲ)、Zn(Ⅱ)、Ag(Ⅰ)、Cd(Ⅱ)和V(Ⅴ)不被萃取,实现了Sn(Ⅳ)与上述金属离子的分离.方法用于Pb-Ca-Sn-Al合金中Sn的分离和测定,平均回收率为97.4

  1. Calibration and measurement uncertainties of a continuous-flow cloud condensation nuclei counter (DMT-CCNC: CCN activation of ammonium sulfate and sodium chloride aerosol particles in theory and experiment

    Directory of Open Access Journals (Sweden)

    D. Rose

    2007-06-01

    Full Text Available Experimental and theoretical uncertainties in the measurement of cloud condensation nuclei (CCN with a continuous-flow thermal-gradient CCN counter from Droplet Measurement Technologies (DMT-CCNC have been assessed by model calculations and calibration experiments with ammonium sulfate and sodium chloride aerosol particles in the diameter range of 20–220 nm. Experiments have been performed in the laboratory and during field measurement campaigns, extending over a period of more than one year and covering a wide range of operating conditions (650–1020 hPa ambient pressure, 0.5–1.0 L min−1 aerosol flow rate, 20–30°C inlet temperature, 4–34 K m−1 temperature gradient. For each set of conditions, the effective water vapor supersaturation (Seff in the CCNC was determined from the measured CCN activation spectra and Köhler model calculations.

    High measurement precision was achieved under stable laboratory conditions, where relative variations of Seff in the CCNC were generally less than ±2%. During field measurements, however, the relative variability increased up to ±5–7%, which can be mostly attributed to variations of the CCNC column top temperature with ambient temperature.

    To assess the accuracy of the Köhler models used to calculate Seff, we have performed a comprehensive comparison and uncertainty analysis of the various Köhler models and thermodynamic parameterizations commonly used in CCN studies. For the relevant supersaturation range (0.05–2%, the relative deviations between different modeling approaches were as high as 25% for (NH42SO4 and 16% for NaCl. The deviations were mostly caused by the different parameterizations for the activity of water in aqueous solutions of (NH42SO4 and NaCl (activity parameterization, osmotic coefficient, and van't Hoff

  2. Apparent and partial molar volumes of long-chain alkyldimethylbenzylammonium chlorides and bromides in aqueous solutions at T=15 deg. C and T=25 deg. C[Alkyldimethylbenzylammonium chlorides; Alkyldimethylbenzylammonium bromides; Micellization; Density; Apparent molar volumes

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Perez, A.; Ruso, J.M.; Nimo, J.; Rodriguez, J.R. E-mail: fmjulio@usc.es

    2003-12-01

    Density measurements of dodecyl- (C{sub 12}DBACl), tetradecyl- (C{sub 14}DBACl), hexadecyldimethylbenzylammonium chloride (C{sub 16}DBACl) and of decyl- (C{sub 10}DBABr) and dodecyldimethylbenzylammonium bromide (C{sub 12}DBABr) in aqueous solutions at T=15 deg. C and T=25 deg. C have been carried out. From these results, apparent and partial molar volumes were calculated. Positive deviations from the Debye-Hueckel limiting law provide evidence for limited association at concentrations below the critical micelle concentration. The change of the apparent molar volume upon micellization was calculated. The relevant parameters have been presented in function of the alkyl chain length. Apparent molar volumes of the present compounds in the micellar phase, V{sub phi}{sup m}, and the change upon micellization, {delta}V{sub phi}{sup m}, have been discussed in terms of temperature and type of counterion.

  3. Determination of Ephedrine and Ammonium Chloride in Tingke Syrups%停咳糖浆中盐酸麻黄碱与氯化铵的含量测定

    Institute of Scientific and Technical Information of China (English)

    区洁雯; 吕冠欣; 孙俊军; 廖永清

    2013-01-01

    Objective:To establish a method for the determination of ephedrine and ammonium chloride in Tingke syrups by HPLC and nitrometry.Method:The analysis of ephedrine was performed on an Agilent ZORBAX SB-C18 (250 mm ×4.6 mm,5 μm)column with 0.1% phosphoric acid (containing 0.1% triethylamine)-methyl cyanides (95∶5) as the mobile phase.The flow rate was 1.0 ml · min-1 and the detection wavelength was 205 nm at 30℃.The analysis of ammonium chloride was performed by nitrometry with 0.05 mol · l-1 sulfuric acid titrant.Result:The linear range of ephedrine was 8.176-65.408 μg · ml-1 (r =0.999 9),and the average recovery was 102.0% (RSD =0.6%,n =6).The average recovery of ammonium chloride was 99.25% (RSD =0.3%,n =6).Conclusion:The methods are accurate and reproducible,and can be used in the quality control of the preparation.%目的:分别建立HPLC法和氮测定法对停咳糖浆中的盐酸麻黄碱和氯化铵进行含量测定.方法:盐酸麻黄碱的测定采用Agilent ZORBAX SB-C18(250 mm×4.6 mm,5μm)色谱柱,0.1%磷酸溶液(含0.1%三乙胺)-乙腈(95∶5)为流动相,流速为1.0ml·min-1,检测波长为205 nm,柱温为30℃.氯化铵的测定以0.05 mol·L-1硫酸滴定液采用氮测定法测定.结果:盐酸麻黄碱在8.176~65.408 μg· ml-1范围内呈良好的线性关系(r=0.999 9),平均回收率为102.0%,RSD为0.6%(n=6),氯化铵的平均回收率为99.25%,RSD为0.3%(n=6).结论:该方法重复性好,准确,可用于该制剂的质量控制.

  4. Removal of copper (II) from aqueous solutions by flotation using polyaluminum chloride silicate (PAX-XL60 S) as coagulant and carbonate ion as activator.

    Science.gov (United States)

    Ghazy, S E; Mahmoud, I A; Ragab, A H

    2006-01-01

    Flotation is a separation technology for removing toxic heavy metal ions from aqueous solutions. Here a simple and rapid flotation procedure is presented for the removal of copper(II) from aqueous solutions. It is based on the use of polyaluminum chloride silicate (PAX-XL60 S) as coagulant and flocculent, carbonate ion as activator and oleic acid (HOL) as surfactant. Both ion and precipitate flotation are included depending on the solution pH. Ion and precipitate flotation in the aqueous HOL-PAX-XL60 S-Cu2+-CO3(2-) system gave powerful preferential removal of Cu2+ (F -100%) over the HOL-PAX-XL60 S-Cu2+ system containing no CO3(2+) ion (F approximately 86%). The role of CO3(2-) ion is also evident from decreasing the dose of PAX-XL60 S from 700 mg l(-1) to 200 mg l(-1). The other parameters, influencing the flotation process, namely: metal ion, surfactant and PAX-XL60 S concentrations, ionic strength, temperature and foreign ions were examined. Moreover, the procedure was successfully applied to recover Cu2+ ions from different volumes up to 11 and from natural water samples.

  5. Liquid-liquid extraction of cadmium(II) by TIOACl (tri-iso-octyl ammonium chloride) ionic liquid and its application to a TIOACl impregnated carbon nanotubes system

    International Nuclear Information System (INIS)

    The extraction of cadmium(II) by the ionic liquid (R3NH+Cl-) (R: tri-iso-octyl) in Exxsol D100 from hydrochloric acid solution has been investigated. The extraction reaction is exothermic. The numerical analysis of metal distribution data suggests the formation of R3NH+CdCl-3 - and (R3NH+)2CdCl42- species in the organic phase. The results obtained for cadmium(II) distribution have been implemented in an impregnated multi-walled carbon nanotubes system. The influence of aqueous solution stirring speed (250-2000 min-1), adsorbent dosage (0.05-0.2 g) and temperature (20 degree centigrade-60 degree centigrade) on cadmium adsorption have been investigated. (Author)

  6. Liquid-liquid extraction of cadmium(II) by TIOACl (tri-iso-octyl ammonium chloride) ionic liquid and its application to a TIOACl impregnated carbon nanotubes system

    Energy Technology Data Exchange (ETDEWEB)

    Alguacil, F. J.; Garcia-Diaz, I.; Lopez, F. A.; Rodriguez, O.

    2015-07-01

    The extraction of cadmium(II) by the ionic liquid (R{sub 3}NH{sup +}Cl{sup -}) (R: tri-iso-octyl) in Exxsol D100 from hydrochloric acid solution has been investigated. The extraction reaction is exothermic. The numerical analysis of metal distribution data suggests the formation of R{sub 3}NH{sup +}CdCl{sup -}{sub 3} - and (R{sub 3}NH{sup +}){sub 2}CdCl{sub 4}{sup 2}- species in the organic phase. The results obtained for cadmium(II) distribution have been implemented in an impregnated multi-walled carbon nanotubes system. The influence of aqueous solution stirring speed (250-2000 min{sup -}1), adsorbent dosage (0.05-0.2 g) and temperature (20 degree centigrade-60 degree centigrade) on cadmium adsorption have been investigated. (Author)

  7. Correlation of biological value of feed phosphates with their solubility in water, dilute hydrogen chloride, dilute citric acid, and neutral ammonium citrate.

    Science.gov (United States)

    Sullivan, T W; Douglas, J H; Gonzalez, N J; Bond, P L

    1992-12-01

    Relative biological values (BV) of 36 feed phosphates were determined with female turkeys in bioassays of 21-day duration using three response criteria: weight gain, tibia ash percentage, and gain:feed ratio. Calcium phosphate, dibasic dihydrate (United States Pharmacopeia) was the reference standard. Nine mono-dicalcium phosphates (M-DCP, 21.0% phosphorus), 13 di-monocalcium phosphates (D-MCP, 18.5% phosphorus), and 14 defluorinated phosphates (DFP, 18.0% phosphorus) were evaluated. The average relative BV for M-DCP, D-MCP, and DFP samples were 97.6, 94.6, and 90.8%, respectively. Solubility of phosphates was determined by four recognized methods. The solvents were water, .4% HCl, 2.0% citric acid (CA), and neutral ammonium citrate (NAC). Water solubility of M-DCP samples was greater (67.5%) than that of D-MCP (38.8%) and DFP (8.9%) samples. Correlation of water solubility of phosphates to their relative BV was quite low, and water solubility was a poor indicator of BV. When .4% HCl was the solvent, correlation coefficients (r) were .55, .33, and .72 for M-DCP, D-MCP, and DFP, respectively. Based on these results and prediction equations, .4% HCl solubility would be inappropriate for estimating BV of M-DCP and D-MCP samples. Solubility of feed phosphates (mainly D-MCP and DFP) in 2.0% CA or NAC was positively correlated with BV; the r values were .87 to .95. Both of these solubility tests provided a good index of BV. However, it would seem inappropriate and risky to replace bioassays totally with these tests. Feed phosphate users could perform either the 2.0% CA or NAC solubility test easily as a screen for BV along with other quality control procedures (i.e., phosphorus, calcium, sodium, and fluoride determinations).

  8. Decolourisation of palm oil mill biogas plant wastewater using Poly-Diallyldimethyl Ammonium Chloride (polyDADMAC) and other chemical coagulants

    Science.gov (United States)

    Zahrim, A. Y.; Dexter, Z. D.

    2016-06-01

    Palm oil mill effluent was expected as a future source of renewable biogas. Nevertheless,colours in palm oil mill biogas plant wastewater (POMBPW) causes negative perception among the public and the wastewater is difficult to be treated biologically. In this study, the performance of various chemical coagulants i.e., calcium lactate, magnesium hydroxide, ferric chloride, aluminium chlorohydrate i.e. CK-800, CK-1000, and polyDADMAC, forPOMBPW colour removal were investigated. PolyDADMAC (1,000 mg/L) shows best colour removal (∼48%). The main coagulation process with polyDADMACcould be due to charge neutralization-bridging mechanism. The zeta potential analysis supports the finding where the value became positive as the dosage increases. The addition of polyDADMAC has increased the conductivity of the treated wastewater up to 9.22%; however, the final pH is maintained (8.0-8.3). It can be deduced that polyDADMAC has potential to treat POMBPW at low dosage.

  9. A novel water-soluble anionic conjugated copolymer containing poly(p-phenylene vinylene) segments: Copolymer synthesis and multilayer construction by assembling poly(diallyl dimethyl ammonium chloride)

    Institute of Scientific and Technical Information of China (English)

    ZHANG Bao; LIN Hang; TANG Jun; LIU JunSong

    2009-01-01

    This paper reports the synthesis of a water soluble conjugated polymer poly(p-phenylene vinylene-co-sodium methacrylate) (ws-P(PV-co-SMA)) and the multilayer of the derived copolymer assembling poly(diallyl dimethyl ammanium chloride) (PDDA). The self-assembling process of the mulUlayer was monitored by UV-vis absorption spectroscopy, and the data indicated a linear increase in film thick-ness with a number of ws-P(PV-co-SMA)/PDDA bilayers. The alternative deposition of ws-P (PV-co-SMA) and PDDA allowed the insertion of a non-conjugated layer between the conjugated layers, thus the migration of the photogenerated polarons was effectively confined in the isolated ws-P (PV-co-SMA) chains. Consequently, the photoluminescence quantum yield reached 0.68, 30 times higher than that of pure poly(p-phenylen vinylene). The distinct electronic interactions between conjugated segments were confirmed by comparative analyses of the excitation spectra and time-resolved photolumines-cence spectra of ws-P(PV-co-SMA) solid film and the assembled multilayers. The confinement effect of the PDDA layer on the photogenerated carriers was verified by the surface photovoltage spectroscopic measurement on both ws-P(PV-co-SMA) solid film and self-assembled multilayers.

  10. 蒸汽再压缩技术回收废水中氯化铵的工程实例%Engineering Example of Recovery Ammonium Chloride from Wastewater by MVR

    Institute of Scientific and Technical Information of China (English)

    弋万

    2016-01-01

    在化工农药产品生产中产生的高氨氮含量废水,具有生物毒性大,可生化性差等特点,属较难降解有机废水。本文利用机械式蒸汽再压缩技术处理某胺化反应产生的高氨氮废水,回收富含的氯化铵晶体,实现了废弃物资源化以及排放量最小化。此废水预处理装置运行结果分析表明,该技术属“源头治理”-“废弃物资源化”的废水治理模式,具有环境-经济双重效益。%High ammonia-n wastewater in the production of chemical pesticide products has characteristics of biological toxicity and poor biodegradability, was refractory organic wastewater. Mechanical Vapor Recompression technology was used to manage high ammonia-n wastewater in amination reaction production, and recycle rich contains ammonium chloride crystals and implemente minimizing wastes and emissions. The analysis of the wastewater pretreatment plant operation showed that the technology was a "source governance"-"waste resource recovery" mode of wastewater treatment, had environmental and economic co-benefits.

  11. Engineering Example of Recovery Ammonium Chloride from Wastewater by MVR%蒸汽再压缩技术回收废水中氯化铵的工程实例

    Institute of Scientific and Technical Information of China (English)

    弋万

    2016-01-01

    High ammonia-n wastewater in the production of chemical pesticide products has characteristics of biological toxicity and poor biodegradability, was refractory organic wastewater. Mechanical Vapor Recompression technology was used to manage high ammonia-n wastewater in amination reaction production, and recycle rich contains ammonium chloride crystals and implemente minimizing wastes and emissions. The analysis of the wastewater pretreatment plant operation showed that the technology was a "source governance"-"waste resource recovery" mode of wastewater treatment, had environmental and economic co-benefits.%在化工农药产品生产中产生的高氨氮含量废水,具有生物毒性大,可生化性差等特点,属较难降解有机废水。本文利用机械式蒸汽再压缩技术处理某胺化反应产生的高氨氮废水,回收富含的氯化铵晶体,实现了废弃物资源化以及排放量最小化。此废水预处理装置运行结果分析表明,该技术属“源头治理”-“废弃物资源化”的废水治理模式,具有环境-经济双重效益。

  12. Hepatoprotective and immunomodulatory properties of aqueous extract of Curcuma longa in carbon tetra chloride intoxicated Swiss albino mice

    Institute of Scientific and Technical Information of China (English)

    Mahuya Sengupta; Gauri Dutta Sharma; Biswajit Chakraborty

    2011-01-01

    Objective: To evaluate the hepatoprotective and immunotherapeutic effects of aqueous extract of turmeric rhizome in CCl4 intoxicated Swiss albino mice. Methods: First group of mice (n=5) received CCl4 treatment at a dose of 0.5 mL/kg bw (i.p.) for 7 days. Second group was fed orally the aqueous extract of turmeric at a dose of 50 mg/kg bw for 15 days. The third group was given both the turmeric extract (for 15 days, orally) and CCl4 (for last 7 days, i.p.). The fourth group was kept as a control. To study the liver function, the transaminase enzymes (SGOT and SGPT) and bilirubin level were measured in the serum of respective groups. For assaying the immunotherapeutic action of Curcuma longa (C. longa), non specific host response parameters like morphological alteration, phagocytosis, nitric oxide release, myeloperoxidase release and intracellular killing capacity of peritoneal macrophages were studied from the respective groups. Results: The result of present study suggested that CCl4 administration increased the level of SGOT and SGPT and bilirubin level in serum. However, the aqueous extract of turmeric reduced the level of SGOT, SGPT and bilirubin in CCl4 intoxicated mice. Apart from damaging the liver system, CCl4 also reduced non specific host response parameters like morphological alteration, phagocytosis, nitric oxide release, myeloperoxidase release and intracellular killing capacity of peritoneal macrophages. Administration of aqueous extract of C. longa offered significant protection from these damaging actions of CCl4 on the non specific host response in the peritoneal macrophages of CCl4 intoxicated mice. Conclusions: In conclusion, the present study suggests that C. longa has immunotherapeutic properties along with its ability to ameliorate hepatotoxicity.

  13. Batch sorption dynamics and equilibrium for the removal of lead ions from aqueous phase using activated carbon developed from coffee residue activated with zinc chloride.

    Science.gov (United States)

    Boudrahem, F; Aissani-Benissad, F; Aït-Amar, H

    2009-07-01

    Lignocellulosic materials are good precursors for the production of activated carbon. In this work, coffee residue has been used as raw material in the preparation of powder activated carbon by the method of chemical activation with zinc chloride for the sorption of Pb(II) from dilute aqueous solutions. The influence of impregnation ratio (ZnCl2/coffee residue) on the physical and chemical properties of the prepared carbons was studied in order to optimize this parameter. The optimum experimental condition for preparing predominantly microporous activated carbons with high pore surface area (890 m2/g) and micropore volume (0.772 cm3/g) is an impregnation ratio of 100%. The developed activated carbon shows substantial capability to sorb lead(II) ions from aqueous solutions and for relative impregnation ratios of 75 and 100%, the maximum uptake is practically the same. Thus, 75% represents the optimal impregnation ratio. Batch experiments were conducted to study the effects of the main parameters such as contact time, initial concentration of Pb(II), solution pH, ionic strength and temperature. The maximum uptake of lead(II) at 25 degrees C was about 63 mg/g of adsorbent at pH 5.8, initial Pb(II) concentration of 10 mg/L, agitation speed of 200 rpm and ionic strength of 0.005 M. The kinetic data were fitted to the models of pseudo-first order and pseudo-second order, and follow closely the pseudo-second order model. Equilibrium sorption isotherms of Pb(II) were analyzed by the Langmuir, Freundlich and Temkin isotherm models. The Freundlich model gives a better fit than the others. Results from this study suggest that activated carbon produced from coffee residue is an effective adsorbent for the removal of lead from aqueous solutions and that ZnCl2 is a suitable activating agent for the preparation of high-porosity carbons. PMID:19447542

  14. Zmiany w składzie chemicznym ściany komórkowej źdźbła pszenicy traktomanej chlorkiem chlorocholiny (CCC [Changes in the cell walls of wheat culms treated utith 2-chloroethyl-trime-thyl-ammonium chloride (CCC

    Directory of Open Access Journals (Sweden)

    Maria Przeszlakowska

    2015-06-01

    Full Text Available The influence of 2-chloroethyl-trimethyl-ammonium chloride (CCC on the content of various constituents of the cell wall of the wheat culms var. Eka Nowa was investigated. Chromatographic analysis of the polysaccharides obtained from the cell wall of the wheat culms has been carried out. The content of pectic substances (pectins and protopectins in nodes and internodes of the wheat culms treated with CCC was determined.

  15. Removal of lead from aqueous solution by activated carbon prepared from Enteromorpha prolifera by zinc chloride activation

    International Nuclear Information System (INIS)

    Activated carbon was prepared from Enteromorpha prolifera (EP) by zinc chloride activation. The physico-chemical properties of EP-activated carbon (EPAC) were characterized by thermal stability, zeta potential and Boehm titration methods. The examination showed that EPAC has a porous structure with a high surface area of 1688 m2/g. Batch adsorption experiments were carried out to study the effect of various parameters such as initial pH, adsorbent dosage, contact time and temperature on Pb(II) ions adsorption properties by EPAC. The kinetic studies showed that the adsorption data followed a pseudo second-order kinetic model. The isotherm analysis indicated that the adsorption data can be represented by Freundlich isotherm model. Thermodynamic studies indicated that the adsorption reaction was a spontaneous and endothermic process.

  16. Formation of La3+, Pr3+, Eu3+, Er3+, and Lu3+ complexes with chloride ions, in aqueous medium

    International Nuclear Information System (INIS)

    The constants of stability of the complexes of La3+, Pr3+, Eu3+, Er3+, and Lu3+ with Cl- ions, its were determined, in the aqueous medium of HCI - HClO4 and by a solvent extraction method. The dinonyl naphtalene sulfonic acid in n-heptane was used as extractant. The lanthanides concentration, it was measured by a VIS spectrophotometry method and by another radiochemical. The ions specific interaction theory (SIT) it was used for the extrapolation to ionic force 0 M. The results indicate that the stability constants of the LnCI2+ species diminishes when increasing the ion force and the charge density. (Author)

  17. 十二烷基二甲基苄基氯化铵对生物除磷的影响研究%EFFECT OF BENZYL DIMETHYL DODECYL AMMONIUM CHLORIDE ON BIOLOGICAL PHOSPHORUS REMOVAL

    Institute of Scientific and Technical Information of China (English)

    乔婧; 刘东方; 李克勋; 陶芸; 张国威; 孙洁

    2011-01-01

    利用静态研究了十二烷基二甲基苄基氯化铵(DDBAC)对生物除磷的影响,通过设置不同DDBAC含量及空白对照对好氧吸磷和厌氧释磷进行了分析.结果表明,厌氧初始COD在400mg·L-1左右时,随着DDBAC负荷的增加,系统释磷能力增强;随着DDBAC含量的增加,吸磷速率降低直至丧失了吸磷特性;DDBAC的存在对生物除磷系统带来了不利影响,使试验污泥的电导率增加,质量浓度40mg·L-1时能明显影响细胞膜的通透性.%Batch experiments were conducted to investigate the effect ofbenzyl dimethyl dodecyl ammonium chloride (DDBAC) on biological phosphorus removal. Different concentrations of DDBAC were acted on the tested sludge under anaerobic and aerobic phase respectively. Results showed that the presence of DDBAC promoted the release of phosphorus while inhibited the uptake of phosphorus. When initial COD was 400 mg·L-1, the increment of P under the aerobic condition acted by 40 mg·L-1 DDBAC which was three times as many as that in control; the phosphorus uptake rate under the aerobic phase decreased until the phenomenon of p-uptake disappeared when the DDBAC reached 10 mg·L-1. ThepresenceoftheQAC negatively affected the performance of biological phosphorus removal. The electrical conductivity of the tested sludge increased sharply with the addition of 40 mg·L-1 DDBAC, which elucidated that DDBAC had an obvious influence on membrane permeability.

  18. Automated determination of nitrate plus nitrite in aqueous samples with flow injection analysis using vanadium (III) chloride as reductant.

    Science.gov (United States)

    Wang, Shu; Lin, Kunning; Chen, Nengwang; Yuan, Dongxing; Ma, Jian

    2016-01-01

    Determination of nitrate in aqueous samples is an important analytical objective for environmental monitoring and assessment. Here we report the first automatic flow injection analysis (FIA) of nitrate (plus nitrite) using VCl3 as reductant instead of the well-known but toxic cadmium column for reducing nitrate to nitrite. The reduced nitrate plus the nitrite originally present in the sample react with the Griess reagent (sulfanilamide and N-1-naphthylethylenediamine dihydrochloride) under acidic condition. The resulting pink azo dye can be detected at 540 nm. The Griess reagent and VCl3 are used as a single mixed reagent solution to simplify the system. The various parameters of the FIA procedure including reagent composition, temperature, volume of the injection loop, and flow rate were carefully investigated and optimized via univariate experimental design. Under the optimized conditions, the linear range and detection limit of this method are 0-100 µM (R(2)=0.9995) and 0.1 µM, respectively. The targeted analytical range can be easily extended to higher concentrations by selecting alternative detection wavelengths or increasing flow rate. The FIA system provides a sample throughput of 20 h(-1), which is much higher than that of previously reported manual methods based on the same chemistry. National reference solutions and different kinds of aqueous samples were analyzed with our method as well as the cadmium column reduction method. The results from our method agree well with both the certified value and the results from the cadmium column reduction method (no significant difference with P=0.95). The spiked recovery varies from 89% to 108% for samples with different matrices, showing insignificant matrix interference in this method. PMID:26695325

  19. Mixed micellar properties of sodium n-octanoate(SOC) with n-octylammonium chloride(OAC) in aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byung Hwan [Korea University of Technology, Chonan (Korea, Republic of)

    2002-12-01

    The critical concentration(CMC) and the counterion binding constant(B) for the mixed micellization of sodium n-octanoate(SOC) with n-octylammonium chloride(OAC) were determined as a function of the overall mole fraction of SOC({alpha}{sub 1}). Various thermodynamic parameters(X{sub i}, {gamma}{sub i}, C{sub i}, a{sub i}{sup M}, and {delta}H{sub mix}) for the mixed micellization of the SOC/OAC systems have been calculated and analyzed by means of the equations derived from the nonideal mixed micellar model. The results show that there are great deviations from the ideal behavior for the mixed micellization of these systems. And other thermodynamic parameters({delta}G{sub m}{sup o}, {delta}H{sub m}{sup o}, and {delta}S{sub m}{sup o}) associated with the micellization of SOC, OAC, and their mixture({alpha}{sub 1}=0.5) have been also estimated from the temperature dependence of CMC and B values, and the significance of these parameters and their relation to the theory of the micelle formation have been considered and analyzed by comparing each other.

  20. Micelle-Vesicle Transition by Cleavage of Disulfide Spacer Chain for Gemini Surfactant in Didodecyldimethylammonium Chloride Aqueous Solutions.

    Science.gov (United States)

    Mizuhashi, Toshinari; Asakawa, Tsuyoshi; Ohta, Akio

    2015-01-01

    We examined the "micelle-vesicle transition" through the mixing effect of single-tailed thiol surfactants produced by the cleavage of gemini surfactants, [C12H25N(CH3)2CH2CH2SSCH2CH2N(CH3)2C12H25] 2Cl (C12SSC12), which have a disulfide bond in the spacer chain. Phase diagrams of C12H25N(CH3)2CH2CH2SHCl-didodecyldimethylammonium chloride (C12SH-DDAC) and C12SSC12-DDAC were determined by conductivity and pyrene fluorescence probe methods. The aggregate diameters were evaluated by dynamic light scattering (DLS). The critical vesicle concentration (CVC) was confirmed by the abrupt increase in the intensity of light scattering with excitation at 335 nm. Vesicle formation was confined to the DDAC-rich region of the C12SSC12-DDAC system, while the vesicle formation region for the C12SH-DDAC system spread out with the addition of dithiothreitol (DTT) to C12SSC12-DDAC. This implies that single-tailed surfactants can induce a more favorable environment for molecular packing of the vesicular surface. The micelle-vesicle transition occurs with disulfide spacer chain cleavage of gemini surfactants at a particular specific concentration range. PMID:26250426

  1. A CATIONIC POLYACRYLAMIDE DISPERSION SYNTHESIS BY DISPERSION POLYMERIZATION IN AQUEOUS SOLUTION

    Directory of Open Access Journals (Sweden)

    Yufeng Wang

    2011-07-01

    Full Text Available A cationic polyacrylamide (CPAM dispersion, the copolymer of acrylamide (AM and acryloyloxyethyltrimethyl ammonium chloride (DAC, has been synthesized through dispersion polymerization in aqueous ammonium sulfate ((NH42SO4 solution. The polymerization was initiated by tert-butyl hydroperoxide (TBHP and ferrisulfas (FeSO4 using poly(dimethyl diallyl ammonium chloride (PDMDAAC as the stabilizer. At the optimal reaction conditions, the relative molecular weight of the CPAM dispersion was 4.2×106, its charge density was 2.2 mmol•g-1, its average particle size was 6.01 μm, and its stability and dissolvability were both excellent. The CPAM dispersion was characterized using Fourier-transform infrared (FTIR spectroscopy, nuclear magnetic resonance (NMR spectroscopy, and differential scanning calorimeter (DSC. Results indicated that the copolymerization was successful.

  2. Contribution to the study to the stress corrosion susceptibility of austenitic stainless steel AISI 304 in aqueous solutions containing chlorides

    International Nuclear Information System (INIS)

    The anodic behaviour of type 304 austenitic stainless steel, stressed in aqueous neutral and acid NaCl solutions, was studied. The experimental technique of the straining electrode, with constant speed and high strain rate, was applied at room temperature and at 900C. The current density on the bare metal, which is exposed to the medium during the straining the specimen, was determined at various potentials for 1N; 0,1N and 0,001N NaCl, at both temperatures, and for 1N H2SO4 + 0,1N NaCl at room temperature. In the 1N NaCl solution, tests were also carried with slightly sensitizes material at 250C and 900C. The possible crack propagation rates were estimated from these data, and parameters related with stress corrosion cracking susceptibility were analised. Potentiodynamic polarization curves were done at several potential scanning rates with and without simultaneous straining of the electrode at the same temperature, in some of the NaCl concentrations, with the aim of comparing the current values with those found in the method described above. These curves were also performed in boiling MgCl2 solutions with and without addition of NaNO3 with the purpose of compare its stress corrosion prognostic capacity in relation of that other types of tests reported. (Author)

  3. Synchrotron-based in situ soft X-ray microscopy of Ag corrosion in aqueous chloride solution

    Science.gov (United States)

    Bozzini, B.; D'Urzo, L.; Gianoncelli, A.; Kaulich, B.; Kiskinova, M.; Prasciolu, M.; Tadjeddine, A.

    2009-09-01

    In this paper we report an in situ X-ray microscopy study of a model metal electrochemistry system, incorporating faradaic reactivity: the anodic corrosion and cathodic electrodeposition of Ag in aqueous systems. The information at sub-μm scale about morpho-chemical evolution of the electrified interface, provided by this novel electroanalytical approach fosters fundamental understanding of important issues concerning material fabrication and stability, which are crucial in developing the next generation electrochemical technologies, such as fuel cells and biosensors. The key methodology challenge faced in this pilot electrochemical experiments is combining a three-electrode configuration and wet environment, which required metal electrodes suitable for transmitting soft X-rays and a sealed cell allowing working in high vacuum. This has been solved via lithographic fabrication route fabricating 75 nm thick Ag electrodes and using Si3N4 membranes as X-ray windows and electrode support. Imaging in the STXM mode with phase contrast allowed us to monitor the corrosion morphologies and metal outgrowth features. Localised thickness variation and the build-up of reaction products of electron density different from that of the starting material have been detected with high sensitivity.

  4. Synchrotron-based in situ soft X-ray microscopy of Ag corrosion in aqueous chloride solution

    Energy Technology Data Exchange (ETDEWEB)

    Bozzini, B; D' Urzo, L [Dipartimento di Ingegneria dell' Innovazione, Universita del Salento, via Monteroni, 73100 Lecce (Italy); Gianoncelli, A; Kaulich, B; Kiskinova, M [Sincrotrone Trieste S.C.p.A., ELETTRA, s.s. 14 km 163.5 in Area Science Park, 34012 Basovizza, Trieste (Italy); Prasciolu, M [CNR-INFM TASC National Laboratory S.S.14 Km 163.5, Area Science Park, 34012 Basovizza, Trieste (Italy); Tadjeddine, A, E-mail: alessandra.gianoncelli@elettra.trieste.i [3UDIL/CNRS, BP34 91898 Orsay Cedex (France)

    2009-09-01

    In this paper we report an in situ X-ray microscopy study of a model metal electrochemistry system, incorporating faradaic reactivity: the anodic corrosion and cathodic electrodeposition of Ag in aqueous systems. The information at sub-{mu}m scale about morpho-chemical evolution of the electrified interface, provided by this novel electroanalytical approach fosters fundamental understanding of important issues concerning material fabrication and stability, which are crucial in developing the next generation electrochemical technologies, such as fuel cells and biosensors. The key methodology challenge faced in this pilot electrochemical experiments is combining a three-electrode configuration and wet environment, which required metal electrodes suitable for transmitting soft X-rays and a sealed cell allowing working in high vacuum. This has been solved via lithographic fabrication route fabricating 75 nm thick Ag electrodes and using Si{sub 3}N{sub 4} membranes as X-ray windows and electrode support. Imaging in the STXM mode with phase contrast allowed us to monitor the corrosion morphologies and metal outgrowth features. Localised thickness variation and the build-up of reaction products of electron density different from that of the starting material have been detected with high sensitivity.

  5. Interfacial Properties of Quaternary Ammonium Gemini Surfactants in Aqueous Solutions%季铵盐型Gemini表面活性剂水溶液的表面和油-水界面特性

    Institute of Scientific and Technical Information of China (English)

    林梅钦; 丁波; 郑晓宇; 毛雷霆; 李明远

    2011-01-01

    用DCAT-21型表面张力及接触角仪测定了不同结构的季铵盐型Gemini表面活性剂Cn-s-Cn·2Br溶液的表面张力和界面张力变化,为选择一种较好的表面活性剂作为驱油剂提供基础.结果表明,烷基链长n均为12时,随联接基团数s的增加,季铵盐型Gemini表面活性剂降低表面和界面张力能力减小.s相同时,随着烷基链长n增加,Gemini表面活性剂的临界胶束浓度(CMC)减小.加入无机盐可以进一步降低Gemini表面活性剂的CMC值.季铵盐型Gemini表面活性剂的CMC值较类似结构的单链单头普通表面活性剂的CMC值低,且达到最低界面张力时的浓度比单链单头普通表面活性剂低2个数量级.Gemini表面活性剂的高表面活性主要由其特殊的分子结构所决定.%Interfacial properties of quaternary ammonium Gemini surfactants in aqueous solution were studied due to their special excellent surface activity in surfactant flooding system. DCAT-21 surface tension meter were adopted to determine the variation of surface tension and interfacial tension of different molecular structures of Cn-s-Cn·2Br in aqueous solution. Effect of mineral salt on the surface activity of Gemini surfactants aqueous solutions were investigated as well. Experiments indicated that the surface and interfacial tension reduction of Cn-s-Cn·2Br aqueous solution decreased as the length of spacer(s) increased while the length of alkyl chain(n) was 12. Critical micelle concentration (CMC) of quaternary ammonium Gemini surfactants decreased as the length of alkyl chain(n) increased. Their CMC were much lower (about 2 orders of magnitude) than that of corresponding common surfactants, and could be lowered by mineral salt. The outstanding surface activity of Gemini surfactants was owing to their unique molecular structure.

  6. Determination of arsenate in aqueous samples by precipitation of the arsenic(V)-molybdate complex with tetraphenylphosphonium chloride and neutron activation analysis or hydride generation atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Elteren, J.T. van; Haselager, N.G.; Das, H.A. (Netherlands Energy Research Foundation, Petten (Netherlands)); Ligny, C.L. de; Agterdenbos, J. (Rijksuniversiteit Utrecht (Netherlands). Analytisch Chemisch Lab.)

    1991-11-05

    Precipitation of As(V) from aqueous samples is achieved by complexation of As(V) with molybdate followed by formation of an insoluble precipitate with tetraphenylphosphonium chloride (TPP{sup +}Cl{sup -}). The selectivity of the method was studied by investigating the behavior of other arsenic species (As(III), monomethylarsonic acid and dimethyl-arsinic acid) using {sup 73}As-labelled species. It follows that differen-tiation between As(V) and the methylated arsenic acids is excellent, but that some As(III) may precipitate. Combination with selective co-precipitation using dibenzyldithiocarbamate for preliminary As(III) removal yields accurate results when used with neutron activation analysis or hydride generation atomic absorption spectrometry. The competition of phosphate with As(V) for complexation with molybdate limits the use to samples with phosphate concentrations ,6 {mu}g ml{sup -1}. Results for some real water samples are presented. The results of both detection methods are in good agreement. (author). 18 refs.; 3 figs.; 5 tabs.

  7. Determination of arsenate in aqueous samples by precipitation of the arsenic(V)-molybdate complex with tetraphenylphosphonium chloride and neutron activation analysis or hydride generation atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Precipitation of As(V) from aqueous samples is achieved by complexation of As(V) with molybdate followed by formation of an insoluble precipitate with tetraphenylphosphonium chloride (TPP+Cl-). The selectivity of the method was studied by investigating the behavior of other arsenic species [As(III), monomethylarsonic acid and dimethyl-arsinic acid] using 73As-labelled species. It follows that differen-tiation between As(V) and the methylated arsenic acids is excellent, but that some As(III) may precipitate. Combination with selective co-precipitation using dibenzyldithiocarbamate for preliminary As(III) removal yields accurate results when used with neutron activation analysis or hydride generation atomic absorption spectrometry. The competition of phosphate with As(V) for complexation with molybdate limits the use to samples with phosphate concentrations ,6 μg ml-1. Results for some real water samples are presented. The results of both detection methods are in good agreement. (author). 18 refs.; 3 figs.; 5 tabs

  8. Solvent extraction-separation of La(III), Eu(III) and Er(III) ions from aqueous chloride medium using carbamoyl-carboxylic acid extractants

    Institute of Scientific and Technical Information of China (English)

    Reyhaneh Safarbali; Mohammad Reza Yaftian; Abbasali Zamani

    2016-01-01

    N,N-dibutyldiglycol amic acid (HLI) and N,N-dioctyldiglycol amic acid (HLI) were synthesized and characterized by con-ventional spectroscopic methods. These molecules were examined as extractants for extraction-separation of La(III), Eu(III) and Er(III), as representative ions of light, middle and heavy rare earths, from aqueous chloride solutions. The analysis of the extraction equilibria revealed that the extracted species of lanthanum and europium ions by both of the extractants had a 1:3 metal to ligand ratio. It was suggested that erbium ions were extracted into the organic phase via the formation of Er(LI or I)2Cl complexes. The effect of the organic diluents on the extraction-separation efficiency of the studied rare earths by HLI and HLI was investigated by comparing the results obtained in dichloromethane and carbon tetrachloride. Regardless to the diluent used, the order of selectivity presented by the investigated extractants was Er(III)>Eu(III)>La(III). It is noteworthy that, a significant enhancement in separation of the studied rare earths by the extractants was achieved in their competitive extraction experiments with respect to that obtained in single component extraction experiments. Applicability of the extractants for the removal of rare earth ions from spent Ni-MH batteries was tested by removal of La(III), Eu(III) and Er(III) ions from simulated leach solution of such batteries.

  9. Solution behavior of iron(III-N,N'-ethylene-bis-(salicylideneiminato-chloride in aqueous methanol at 298.15, 303.15 and 313.15K

    Directory of Open Access Journals (Sweden)

    Brahman Dhiraj

    2014-01-01

    Full Text Available In this study partial molar volumes (φV0 and viscosity B-coefficients of iron(III-N, N'-ethylene-bis(salicylideneiminato-chloride, abbreviated as FeIII(salenCl, in different aqueous methanol solutions were determined from solution density and viscosity measurements at temperatures 298.15, 303.15, and 313.15 K under ambient pressure. Apparent molar volumes (φV and densities (ρ were used to calculate the apparent molar expansibilities (φE, the partial molar expansibilities (φE0 and the temperature dependence of the partial molar expansibilities (φE0 at constant pressure, (δφE0/δTP of FeIII(salenCl solutions to reveal the nature of different interactions in the ternary solutions. The transition state theory was applied to analyze the viscosity B-coefficients on the basis of the activation parameters of viscous flow. The overall results indicated strong solute-solvent interactions between FeIII(salenCl and the solvent molecules, preferentially with water molecules and that FeIII(salenCl acts as a net structure promoter in the ternary solutions. UV-VIS absorption spectra of the ternary solutions also stand in support of the results obtained.

  10. Viscosity and density tables of sodium chloride solutions

    Energy Technology Data Exchange (ETDEWEB)

    Fair, J.A.; Ozbek, H. (comps.)

    1977-04-01

    A file is presented containing tabulated data extracted from the scientific literature on the density and viscosity of aqueous sodium chloride solutions. Also included is a bibliography of the properties of aqueous sodium chloride solutions. (MHR)

  11. 丙烯酰胺与季铵类阳离子单体双水相共聚的二次相分离%DOUBLE PHASE SEPARATION OF AQUEOUS TWO-PHASE COPOLYMERIZATION OF ACRYLAMIDE WITH QUATERNARY AMMONIUM CATIONIC MONOMERS

    Institute of Scientific and Technical Information of China (English)

    商宽祥; 单国荣

    2012-01-01

    以(2-甲基丙烯酰氧乙基)三甲基氯化铵(DMC)为例,用分光光度法研究了丙烯酰胺(AM)与季铵类阳离子单体在聚乙二醇(PEG)水溶液中双水相共聚的二次相分离.提出了二次相分离的机理,认为是阳离子单体单元的电离使得聚合物带上了正电荷,大分子间的静电排斥作用增加了其在PEG相中的溶解性(增容作用).讨论了反应条件对体系二次相分离的影响,发现二次相分离在一定的单体浓度和PEG浓度、以及适当的单体比例和PEG分子量条件下才能发生.总单体用量或PEG用量增加,第二次分相先出现后消失;PEG分子量增大,第二次分相逐渐明显;反应温度升高,两次分相更快完成.DMC摩尔分率为0.25~ 0.60时,第一次分相的临界转化率很小,第二次分相的临界转化率则随DMC摩尔分率的增加而增大;DMC摩尔分率超过0.60后,聚合反应主要在过渡区完成,第二次分相难以发生.%In the aqueous two-phase copolymerization of acrylamide ( AM ) with quaternary ammonium cationic monomers, such as 2-methylacryloylxyethyl trimethyl ammonium chloride (DMC),in aqueous poly-(ethylene glycol) (PEG) solution a double phase separation process was observed. In order to fix the critical points,the spectrophotometer was employed to detect the transmittance of the copolymerization system on-line. The transmittance curves showed three intervals. At the first interval, the transmittance keeps constant at the beginning,and then drops off quickly. At the second interval, the transmittance stops dropping and begins to increase. And at the last interval,the transmittance stops to keep constant for a moment,and then drops rapidly to nearly zero. When acrylamide was copolymerized with different monomers, the double phase separation process can be observed only for DMC and acryloylxyethyl trimethyl ammonium chloride ( DAC ) . It confirms that the double phase separation is attributed to the cationic nature of

  12. Thermodynamic and Spectroscopic Investigation of Interactions between Reactive Red 223 and Reactive Orange 122 Anionic Dyes and Cetyltrimethyl Ammonium Bromide (CTAB Cationic Surfactant in Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Muhammad Irfan

    2014-01-01

    Full Text Available The present study describes the conductometric and spectroscopic study of the interaction of reactive anionic dyes, namely, reactive red 223 and reactive orange 122 with the cationic surfactant cetyltrimethyl ammonium bromide (CTAB. In a systematic investigation, the electrical conductivity data was used to calculate various thermodynamic parameters such as free energy (ΔG, enthalpy (ΔH, and the entropy (ΔS of solubilization. The trend of change in these thermodynamic quantities indicates toward the entropy driven solubilization process. Moreover, the results from spectroscopic data reveal high degree of solubilization, with strong interactions observed in the cases of both dyes and the CTAB. The spontaneous nature of solubilization and binding was evident from the observed negative values of free energies (ΔGp and ΔGb.

  13. Thermodynamic and spectroscopic investigation of interactions between reactive red 223 and reactive orange 122 anionic dyes and cetyltrimethyl ammonium bromide (CTAB) cationic surfactant in aqueous solution.

    Science.gov (United States)

    Irfan, Muhammad; Usman, Muhammad; Mansha, Asim; Rasool, Nasir; Ibrahim, Muhammad; Rana, Usman Ali; Siddiq, Mohammad; Zia-Ul-Haq, Muhammad; Jaafar, Hawa Z E; Khan, Salah Ud-Din

    2014-01-01

    The present study describes the conductometric and spectroscopic study of the interaction of reactive anionic dyes, namely, reactive red 223 and reactive orange 122 with the cationic surfactant cetyltrimethyl ammonium bromide (CTAB). In a systematic investigation, the electrical conductivity data was used to calculate various thermodynamic parameters such as free energy (ΔG), enthalpy (ΔH), and the entropy (ΔS) of solubilization. The trend of change in these thermodynamic quantities indicates toward the entropy driven solubilization process. Moreover, the results from spectroscopic data reveal high degree of solubilization, with strong interactions observed in the cases of both dyes and the CTAB. The spontaneous nature of solubilization and binding was evident from the observed negative values of free energies (ΔG p and ΔG b).

  14. The role of radiolytically generated species in radiation-induced polymerization of vinylbenzyltrimethylammonium chloride (VBT) in aqueous solution. Steady-state and pulse radiolysis study

    International Nuclear Information System (INIS)

    Radiation-induced polymerization of vinylbenzyltrimethylammonium chloride (VBT) in aqueous solution has been investigated by steady-state and pulse radiolysis techniques. The effects of dose, dose rate, monomer concentration, pH, and ambient conditions on steady state polymerization were investigated. The reactions of primary radicals of water radiolysis, such as OH radical, e-aq, and H atom, were studied. The reactions of other chemically active species such as O.-, oxidizing radicals such as N3., Cl2.-, Br2.-, SO4.-, and a reducing specie such as CO2.- with VBT were also investigated. The reaction of VBT with OH radical and H atom were investigated by formation kinetics and by competition kinetics. The rate constant values for the reaction of OH radical with VBT were 4.7 x 109 dm3 mol-1 s-1 and 1.7 x 1010 dm3 mol-1 s-1 by formation kinetics and by competition kinetics, respectively. The results indicate that OH radicals undergo electron transfer reactions (resulting in a radical cation) and addition reactions. The hydrated electron reacts with VBT with a rate constant of 1.9 x 1010 dm3 mol-1 s-1 to form an anion. At pH ∼1, H atom reaction with VBT is diffusion controlled with a rate constant of 5.1 x 109 dm3 mol-1 s-1 as determined by formation kinetics and 1.7 x 1010 dm3 mol-1 s-1 as determined by competition kinetics. VBT radical anion reacts with VBT at a rate that is almost twice the rate at which VBT radical cation reacts with VBT, indicating anionic initiation of the polymerization of VBT. VBT undergoes very fast steady-state polymerization and dose rate; the presence of efficient radical quenchers such as oxygen and concentration of VBT in the aqueous solution affects the extent of polymerization. Typically, a dose of 4 kGy is sufficient to achieve 80-85% polymerization. The monomer solution shows a drastic increase in the viscosity of the solution, which finally gels to a soft rubbery mass. (author)

  15. Photo-Fenton oxidation of phenol and organochlorides (2,4-DCP and 2,4-D) in aqueous alkaline medium with high chloride concentration.

    Science.gov (United States)

    Luna, Airton J; Chiavone-Filho, Osvaldo; Machulek, Amilcar; de Moraes, José Ermírio F; Nascimento, Cláudio A O

    2012-11-30

    A highly concentrated aqueous saline-containing solution of phenol, 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4-dichlorophenol (2,4-DCP) was treated by the photo-Fenton process in a system composed of an annular reactor with a quartz immersion well and a medium-pressure mercury lamp (450 W). The study was conducted under special conditions to minimize the costs of acidification and neutralization, which are usual steps in this type of process. Photochemical reactions were carried out to investigate the influence of some process variables such as the initial concentration of Fe(2+) ([Fe(2+)](0)) from 1.0 up to 2.5 mM, the rate in mmol of H(2)O(2) fed into the system (FH(2)O(2);in) from 3.67 up to 7.33 mmol of H(2)O(2)/min during 120 min of reaction time, and the initial pH (pH(0)) from 3.0 up to 9.0 in the presence and absence of NaCl (60.0 g/L). Although the optimum pH for the photo-Fenton process is about 3.0, this particular system performed well in experimental conditions starting at alkaline and neutral pH. The results obtained here are promising for industrial applications, particularly in view of the high concentration of chloride, a known hydroxyl radical scavenger and the main oxidant present in photo-Fenton processes. PMID:22809483

  16. Photo-Fenton oxidation of phenol and organochlorides (2,4-DCP and 2,4-D) in aqueous alkaline medium with high chloride concentration.

    Science.gov (United States)

    Luna, Airton J; Chiavone-Filho, Osvaldo; Machulek, Amilcar; de Moraes, José Ermírio F; Nascimento, Cláudio A O

    2012-11-30

    A highly concentrated aqueous saline-containing solution of phenol, 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4-dichlorophenol (2,4-DCP) was treated by the photo-Fenton process in a system composed of an annular reactor with a quartz immersion well and a medium-pressure mercury lamp (450 W). The study was conducted under special conditions to minimize the costs of acidification and neutralization, which are usual steps in this type of process. Photochemical reactions were carried out to investigate the influence of some process variables such as the initial concentration of Fe(2+) ([Fe(2+)](0)) from 1.0 up to 2.5 mM, the rate in mmol of H(2)O(2) fed into the system (FH(2)O(2);in) from 3.67 up to 7.33 mmol of H(2)O(2)/min during 120 min of reaction time, and the initial pH (pH(0)) from 3.0 up to 9.0 in the presence and absence of NaCl (60.0 g/L). Although the optimum pH for the photo-Fenton process is about 3.0, this particular system performed well in experimental conditions starting at alkaline and neutral pH. The results obtained here are promising for industrial applications, particularly in view of the high concentration of chloride, a known hydroxyl radical scavenger and the main oxidant present in photo-Fenton processes.

  17. Pectinases partitioning in aqueous two-phase systems: an integration of the systems poly(ethylene glycol/crude dextran and poly(ethylene glycol/ammonium sulphate

    Directory of Open Access Journals (Sweden)

    STANA N. PEJIN

    2004-04-01

    Full Text Available The partitioning of pectinases in the poly(ethylene glucol4000/ammonium sulpohate system was studied and also its application for enzymes extraction from the top phase of the poly(ethylene glucol4000/crude dextran system. Almost complete one-sided partition of endo-pectinase and exo-pectinase to the bottom phase of the polymer/salt system was achieved at a tie-line length of 37.16 %. The concentration factors were 1.73 and 3.25, respectively. The highest total endo- and exo-pectinase yields (72.41 % and 69.46 %, respectively were obtained by integration of the polymer/polymer system at a tie-line of 8.61 % and a high phase volume ratio and the polymer/salt system at a tie-line of 30.23 % and a low phase volume ratio. Integration of the partitioning at a high tie-line length in the polymer/polimer and a low tie-line length in the polymer/salt system resulted in a total concentration factor of 1.5 and a purification of 1.66 fold for exo-pectinase. The addition of phosphate to this integrated system improved the total concentration factor and purification fold of the activity to 1.73 and 2.14, respectively.

  18. Molecular dynamics simulation study of ionic hydration and ion association in dilute and 1 molal aqueous sodium chloride solutions from ambient to supercritical conditions

    Science.gov (United States)

    Driesner, T.; Seward, T. M.; Tironi, I. G.

    1998-09-01

    The increasing demand for accurate equations of state of fluids under extreme conditions and the need for a detailed microscopic picture of aqueous fluids in some areas of geochemistry (e.g., mineral dissolution/precipitation kinetics) potentially make molecular dynamics (MD) simulations a powerful tool for theoretical geochemistry. We present MD simulations of infinitely dilute and 1 molal aqueous NaCl solutions that have been carried out in order to study the systematics of hydration and ion association over a wide range of conditions from ambient to supercritical and compare them to the available experimental data. In the dilute case, the hydration number of the Na + ion remains essentially constant around 5.5 from ambient to supercritical temperatures when the density is kept constant at 1 g cm -3 but decreases to below 5 along the liquid-vapor curve. In both cases, the average ion-first shell water distance decreases by about 0.03 Å from ambient to near critical temperatures. The Cl - ion shows a slight expansion of the first hydration shell by about 0.02 Å from ambient to near critical temperatures. The geometric definition of the first hydration shell becomes ambiguous due to a shift of the position of the first minimum of the Cl-O radial distribution function. In the case of the 1 molal solution, the contraction of the Na + first hydration shell is similar to that in the dilute case whereas the hydration number decreases drastically from 4.9 to 2.8 due to strong ion association. The released waters are replaced on a near 1:1 basis by chloride ions. Polynuclear clusters as predicted by Oelkers and Helgeson (1993b) are observed in the high temperature systems. The hydration shell of the Cl --ion shows significant deviation from the behavior in dilute systems, that is, at near vapor saturated conditions, the expansion of the hydration shell is significantly larger (0.12 Å from ambient to near critical temperatures). Due to a very large shift of the first

  19. Immersion freezing of water and aqueous ammonium sulfate droplets initiated by humic-like substances as a function of water activity

    Directory of Open Access Journals (Sweden)

    Y. J. Rigg

    2013-07-01

    Full Text Available Immersion freezing of water and aqueous (NH42SO4 droplets containing leonardite (LEO and Pahokee peat (PP serving as surrogates for humic-like substances (HULIS has been investigated. Organic aerosol containing HULIS are ubiquitous in the atmosphere; however, their potential for ice cloud formation is uncertain. Immersion freezing has been studied for temperatures as low as 215 K and solution water activity, aw, from 0.85 to 1.0. The freezing temperatures of water and aqueous solution droplets containing LEO and PP are 5–15 K warmer than homogeneous ice nucleation temperatures. Heterogeneous freezing temperatures can be represented by a horizontal shift of the ice melting curve as a function of solution aw by Δaw = 0.2703 and 0.2466, respectively. Corresponding hetrogeneous ice nucleation rate coefficients, Jhet, are (9.6 ± 2.5×104 and (5.4 ± 1.4×104 cm−2 s−1 for LEO and PP containing droplets, respectively, and remain constant along freezing curves characterized by Δaw. Consequently predictions of freezing temperatures and kinetics can be made without knowledge of the solute type when relative humidity and ice nuclei (IN surface areas are known. The acquired ice nucleation data are applied to evaluate different approaches to fit and reproduce experimentally derived frozen fractions. In addition, we apply a basic formulation of classical nucleation theory (α(T-model to calculate contact angles and frozen fractions. Contact angles calculated for each ice nucleus as a function of temperature, α(T-model, reproduce exactly experimentally derived frozen fractions without involving free-fit parameters. However, assigning the IN a single contact angle for the entire population (single-α model is not suited to represent the frozen fractions. Application of α-PDF, active sites, and deterministic model approaches to measured frozen fractions yield similar good representations. Furthermore, when using a single parameterization of α-PDF or

  20. Crystal structure of the inclusion complex 25-benzo-ylmeth-oxy-5,11,17,23-tetra-tert-butyl-26,27,28-trihy-droxy-2,8,14,20-tetra-thia-calix[4]arene-tetra-ethyl-ammonium chloride (1/1).

    Science.gov (United States)

    Akkurt, Mehmet; Jasinski, Jerry P; Mohamed, Shaaban K; Omran, Omran A; Albayati, Mustafa R

    2015-11-01

    The asymmetric unit of the title compound, C48H54O5S4·N(C2H5)4 (+)·Cl(-), contains two tetra-tert-butyl-[(benzo-yl)meth-oxy]-trihy-droxy-tetra-thia-calix[4]arene mol-ecules, two tetra-ethyl-ammonium cations and two chloride anions. The two calixarene molecules in the asymmetric unit each display a cone conformation. There are no significant differences between the two independent molecules. The guest species do not sit within the calixarene 'buckets'. In the crystal, extensive O-H⋯O, O-H⋯S and O-H⋯Cl hydrogen bonds and weak C-H⋯O, C-H⋯S and C-H⋯Cl inter-actions link the thia-calixarene mol-ecules, tetra-ethyl-ammonium cations and chloride anions, forming a three-dimensional network encompassing channels running parallel to the a-axis direction. The structure contains a solvent-accessible void of 76 (3) Å(3), but no solvent mol-ecule could reasonably be located. The crystal studied was an inversion twin with a 0.57 (8):0.43 (8) domain ratio. PMID:26594550

  1. On the evaporation of ammonium sulfate solution

    Energy Technology Data Exchange (ETDEWEB)

    Drisdell, Walter S.; Saykally, Richard J.; Cohen, Ronald C.

    2009-07-16

    Aqueous evaporation and condensation kinetics are poorly understood, and uncertainties in their rates affect predictions of cloud behavior and therefore climate. We measured the cooling rate of 3 M ammonium sulfate droplets undergoing free evaporation via Raman thermometry. Analysis of the measurements yields a value of 0.58 {+-} 0.05 for the evaporation coefficient, identical to that previously determined for pure water. These results imply that subsaturated aqueous ammonium sulfate, which is the most abundant inorganic component of atmospheric aerosol, does not affect the vapor-liquid exchange mechanism for cloud droplets, despite reducing the saturation vapor pressure of water significantly.

  2. On the evaporation of ammonium sulfate solution.

    Science.gov (United States)

    Drisdell, Walter S; Saykally, Richard J; Cohen, Ronald C

    2009-11-10

    Aqueous evaporation and condensation kinetics are poorly understood, and uncertainties in their rates affect predictions of cloud behavior and therefore climate. We measured the cooling rate of 3 M ammonium sulfate droplets undergoing free evaporation via Raman thermometry. Analysis of the measurements yields a value of 0.58 +/- 0.05 for the evaporation coefficient, identical to that previously determined for pure water. These results imply that subsaturated aqueous ammonium sulfate, which is the most abundant inorganic component of atmospheric aerosol, does not affect the vapor-liquid exchange mechanism for cloud droplets, despite reducing the saturation vapor pressure of water significantly. PMID:19861551

  3. Effects of Temperature and Drying and Wetting Alternation on Ammonium Fixation in Manured Loessial Soil

    Institute of Scientific and Technical Information of China (English)

    FANXIAOLIN; LILING; 等

    1996-01-01

    Effects of temperature and drying and wetting alternation (DWA) on ammonium fixation in manured loessial soil were studied by means of Batch Equilibrium with varying concentration solutions of ammonium chloride.ammonium fixation time,and soil clay contents.The purpose of the research was to find out the pattern of ammonium fixation affected by the varying factors.The results showed a remarkable variation in ammonium fixation.Fixed ammonium increased with temperature and treatments of DWA.The ammonium fixation in manured loessial soil was characterized by the effect of temperature and DWA.

  4. Synthesis and structure characterization of diethyldiallylammonium chloride

    Institute of Scientific and Technical Information of China (English)

    刘立华; 龚竹青; 郑雅杰

    2003-01-01

    The unsaturated quaternary ammonium salt diethyldiallylammonium chloride(DEDAAC) was synthesized in a two-step synthetic method. The influences of the adding method of raw materials and temperature on the yields of diethylallylamine (DEAA), and drying and temperature on the synthesis of DEDAAC were investigated. The content of in-process product DEAA was determined by non-aqueous titration. The structure of product DEDAAC was identified with IR, 1 H NMR and elemental analysis. The results show that adding allyl chloride and sodium hydroxide alternately can increase the yield of DEAA and decrease by-products. In further synthesizing of DEDAAC from DEAA, the step of drying DEAA is very necessary. When DEAA is dried by solid sodium hydroxide, good columnar crystals with a high purity(mp 199.5-201.0 ℃) are obtained; when DEAA is undried or the content of water in DEAA is above 20%, only platelets with bad quality are obtained even without crystals. The suitable synthesis conditions for DEAA and DEDAAC are 35 ℃, 6 h and 40 ℃, 36 h, respectively, and their yields are 69.7% and 67.3%, respectively.

  5. Preparation and Characterization of Anhydrous Magnesium Chloride in Organic Solvent%有机溶剂法无水氯化镁的制备与表征

    Institute of Scientific and Technical Information of China (English)

    周宁波; 陈白珍; 何新快; 李义兵

    2005-01-01

    Ammonium carnallite was synthesized by hydrated magnesium chloride in salt lake and ammonium chloride solution. Dehydrated ammonium carnallite was dissolved in methanol under low temperature by feeding ammonia, to prepare anhydrous magnesium chloride. The results show that anhydrous magnesium chloride contains magnesium oxide in an amount less than 0.1% by weight, the yield of magnesium chloride was above 99.5%. Ammonium carnallite, ammoniation magnesium chloride and anhydrous magnesium chloride were characterized by thermoanalysis, X-ray powder diffraction and scanning electron microscopy.

  6. Molecular interactions of 1,2-dihydroxyethyl-3,4-dihydroxyfuran-2-one in aqueous N-cetyl-N,N,N-trimethyl ammonium bromide solutions with reference to manifestation of solvation

    International Nuclear Information System (INIS)

    Highlights: ► φv0 values for ascorbic acid indicate the presence of strong solute–solvent interactions. ► B-coefficient values for ascorbic acid also indicate the presence of strong solute–solvent interactions. ► These interactions are further strengthened at higher temperatures and higher concentrations of cetrimonium bromide in ternary solutions. ► This study also reveals that ascorbic acid acts as a structure breaker in the solvent mixtures studied. - Abstract: Apparent molar volumes (φv) and viscosity B-coefficients for 1,2-dihydroxyethyl-3,4-dihydroxyfuran-2-one (ascorbic acid) in (0.001, 0.003, and 0.005) mol · dm−3 aqueous cetrimonium bromide (N-cetyl-N,N,N-trimethyl ammonium bromide) (C19H42BrN) solutions have been determined from solution density, ρ, and viscosity, η, measurements at T = (298.15, 308.15, and 318.15) K as a function of the concentration of ascorbic acid. Within the investigated temperature range, the relation: φv0=a0+a1T+a2T2 , hase been used to describe the partial molar volume φv0. These results, in conjunction with the results obtained in pure water, have been used to calculate the standard volumes of transfer Δφv0 and viscosity B-coefficients of transfer for ascorbic acid from water to aqueous cetrimonium bromide solutions for rationalizing various interactions in the ternary solutions. The structure making or breaking ability of ascorbic acid has been discussed in terms of the sign of (∂2φv0/∂T2)P. An increase in the transfer volume of ascorbic acid with increasing cetrimonium bromide concentration has been explained by the Friedman–Krishnan co-sphere model. The activation parameters of viscous flow for the ternary solutions studied have also been calculated and explained by the application of transition state theory. The 3-D representation of the investigated molecules concerned with this paper is shown below for a better understanding.▪

  7. 焙烧硼钠钙石在高固液化比氯化铵溶液中的熔解动力学%Dissolution Kinetics of Calcined Ulexite in Ammonium Chloride Solutions at High Solid-to-Liquid Ratios

    Institute of Scientific and Technical Information of China (English)

    G(U)R; Aycan

    2006-01-01

    The dissolution kinetics of calcined ulexite in ammonium chloride solutions at high solid-to-liquid ratios were investigated. In the experiments, calcination temperature, solution concentration, reaction temperature, and prehydration were chosen as parameters. It was observed that the dissolution rate increased with increasing calcination temperature, solution concentration, and reaction temperature, whereas it was not affected by pre-hydration. Employing graphical and statistic methods, the dissolution rate, based on homogeneous reaction model,can be given as: (1-X(B2O3))-1-1=k(c(NH4Cl))1.982t. The activation energy for the dissolution of the ulexite sample calcined at 160 ℃ was found to be

  8. Crystal structure of the inclusion complex 25-benzo­ylmeth­oxy-5,11,17,23-tetra-tert-butyl-26,27,28-trihy­droxy-2,8,14,20-tetra­thia­calix[4]arene–tetra­ethyl­ammonium chloride (1/1)

    OpenAIRE

    Akkurt, Mehmet; Jerry P. Jasinski; Shaaban K. Mohamed; Omran, Omran A.; Mustafa R. Albayati

    2015-01-01

    The asymmetric unit of the title compound, C48H54O5S4·N(C2H5)4 +·Cl−, contains two tetra-tert-butyl-[(benzo­yl)meth­oxy]-trihy­droxy-tetra­thia­calix[4]arene mol­ecules, two tetra­ethyl­ammonium cations and two chloride anions. The two calixarene molecules in the asymmetric unit each display a cone conformation. There are no significant differences between the two independent molecules. The guest species do not sit within the calixarene ‘buckets’. In the crystal, extensive O—H⋯O, O—H⋯S and O—...

  9. Synthesis of high molecular weight polylactic acid from aqueous lactic acid co-catalyzed by tin(II)chloride dihydrate and succinic anhydride

    Institute of Scientific and Technical Information of China (English)

    LEI Ziqiang; BAI Yanbin; WANG Shoufeng

    2005-01-01

    Polylactic acid was synthesized from commercial available cheap aqueous lactic acid (85%―90% w/w) using succinic anhydride and SnCl2·2H2O as catalyst in the absence of organic solvents. As a result, polylactic acid with a molecular weight of 60000 was prepared in 10 h. The new procedure is much simple, cheap and outstanding in that the start material is aqueous lactic acid; the catalytic system is environmentally benign.

  10. The Study on Detection of Chloride Ion in Flue Gas Ammonium Sulfate Slurry by Automatic Potentiometric Titration Method%自动电位滴定法测定烟气氨法脱硫模拟浆液中氯离子的研究

    Institute of Scientific and Technical Information of China (English)

    杭蕾; 吕程; 陈慧慧; 连洲洋; 袁礼锐; 魏无际

    2015-01-01

    Chloride ion content of ammonia desulfurization process is an important monitoring indicators and this paper dis-cusses the detection of chloride ions in ammonium sulfate slurry by automatic potentiometric titration .The results show that :adding ethanol helps to increase the magnitude of the potential jump ;when pH=3-5 ,the result is accurate ;the recovery rate keeps between 90% and 110% ;compared with the Mohr method ,the test result is more accurate and precise and free from ash color;also the tested result is close to ion chromatography detection result ,but the high concentrations of chloride ion potentiometric titration is more advantageous .%氯离子含量是氨法脱硫工艺中的一个重要监控指标,用自动电位滴定法测定氨法脱硫浆液中的氯离子。结果表明,实验加入乙醇有利于增大电位突跃幅度;pH值为3~5时实验结果准确;加标回收率为90%~110%;与莫尔法相比,测定结果准确度、精密度更高,且不受灰分颜色干扰;与离子色谱法测定结果准确度、精密度相近,但测定高浓度氯离子电位滴定法更有优势。

  11. Ammonium Bicarbonate Transport in Anion Exchange Membranes for Salinity Gradient Energy

    KAUST Repository

    Geise, Geoffrey M.

    2013-09-17

    Many salinity gradient energy technologies such as reverse electrodialysis (RED) rely on highly selective anion transport through polymeric anion exchange membranes. While there is considerable interest in using thermolytic solutions such as ammonium bicarbonate (AmB) in RED processes for closed-loop conversion of heat energy to electricity, little is known about membrane performance in this electrolyte. The resistances of two commercially available cation exchange membranes in AmB were lower than their resistances in NaCl. However, the resistances of commercially available anion exchange membranes (AEMs) were much larger in AmB than in NaCl, which would adversely affect energy recovery. The properties of a series of quaternary ammonium-functionalized poly(phenylene oxide) and Radel-based AEMs were therefore examined to understand the reasons for increased resistance in AmB to overcome this performance penalty due to the lower mobility of bicarbonate, 4.59 × 10-4 cm2/(V s), compared to chloride, 7.90 × 10-4 cm2/(V s) (the dilute aqueous solution mobility ratio of HCO3 - to Cl- is 0.58). Most membrane resistances were generally consistent with the dilute solution mobilities of the anions. For a few key samples, however, increased water uptake in AmB solution reduced the ionic resistance of the polymer compared to its resistance in NaCl solution. This increased water uptake was attributed to the greater hydration of the bicarbonate ion compared to the chloride ion. The increased resistance due to the use of bicarbonate as opposed to chloride ions in AEMs can therefore be mitigated by designing polymers that swell more in AmB compared to NaCl solutions, enabling more efficient energy recovery using AmB thermolytic solutions in RED. © 2013 American Chemical Society.

  12. Elevated ammonium levels

    DEFF Research Database (Denmark)

    Søgaard, Rikke; Novak, Ivana; MacAulay, Nanna

    2012-01-01

    Increased ammonium (NH(4)(+)/NH(3)) in the brain is a significant factor in the pathophysiology of hepatic encephalopathy, which involves altered glutamatergic neurotransmission. In glial cell cultures and brain slices, glutamate uptake either decreases or increases following acute ammonium expos...

  13. New Data on Activity Coefficients of Potassium, Nitrate, and Chloride Ions in Aqueous Solutions of KNO3 and KCl by Ion Selective Electrodes

    OpenAIRE

    Debasmita Dash; Shekhar Kumar; C. Mallika; U. Kamachi Mudali

    2012-01-01

    Ion selective electrodes (ISEs) are used to measure the single-ion activity coefficients in aqueous solutions of KNO3 and KCl at 298.15 K against a double-junction reference electrode. The EMF responses of ISEs up to 0.01 m are plotted to obtain the slope and intercept values. The obtained slopes and intercepts are used in Nernst equation for higher concentrated solutions for calculation of individual ion activity coefficient. The mean ionic activity coefficients are estimated from single ion...

  14. Light-absorbing secondary organic material formed by glyoxal in aqueous aerosol mimics

    Directory of Open Access Journals (Sweden)

    E. L. Shapiro

    2009-04-01

    Full Text Available Light-absorbing and high-molecular-weight secondary organic products were observed to result from the reaction of glyoxal in mildly acidic (pH=4 aqueous inorganic salt solutions mimicking aqueous tropospheric aerosol particles. High-molecular-weight (500–600 amu products were observed when ammonium sulfate ((NH42SO4 or sodium chloride (NaCl was present in the aqueous phase. The products formed in (NH42SO4 or ammonium nitrate (NH4NO3 solutions absorb light at UV and visible wavelengths. Substantial absorption at 300–400 nm develops within two hours, and absorption between 400–600 nm develops within days. Pendant drop tensiometry measurements show that the products are not surface-active. The experimental results along with ab initio predictions of the UV/Vis absorption of potential products suggest a mechanism involving the participation of the ammonium ion. If similar products are formed in atmospheric aerosol particles, they could change the optical properties of the seed aerosol over its lifetime.

  15. Structural parameters of concentrated aqueous solutions of lithium chloride under extreme conditions from the data of integral equations method. The effect of isothermal compression

    International Nuclear Information System (INIS)

    Structure formation of aqueous solutions LiCl:nH2O (n = 3.15, 8.05, 14.90) under conditions of isothermal compression (T 523 K, P 100-1500 bar) was studied in the framework of integral equations method. It was ascertained that isothermal compression produces a weak effect on the structure of volumetric solvent in the systems considered. Irrespective of solution concentration the tetrahedral ordering of water molecules is absent in the entire range of pressures, while the number of OH bonds actually does not change. In all the solutions compression involves inessential strengthening of coordinating ability of both ions. In the context described a slight growth of the number of hydrate-separated ionic pairs and an insignificant decrease in the number of contact ionic pairs are observed

  16. Protective effect of an aqueous extract of Harpagophytum procumbens upon Escherichia coli strains submitted to the lethal action of stannous chloride.

    Science.gov (United States)

    Almeida, M C; Soares, S F; Abreu, P R C; Jesus, L M; Brito, L C; Bernardo-Filho, M

    2007-01-01

    Regardless of its lethal effects upon Escherichia coli (E. coli) cultures trough the production of free radicals (FR), stannous chloride (SnCl2) remains to be the most used reducing agent on the production of technetium-99m radiopharmaceuticals, to obtain images on nuclear medicine. Moreover, authors have reported that vegetal extracts are able to protect Escherichia coli cultures against the cytotoxicity of this agent. Harpagophytum procumbens, also known as Devil's Claw, is a plant used in folk medicine, as an analgesic and anti-inflammatory in cases of joint and back pain, on the treatment of degenerative rheumatoid arthritis, osteoarthritis, kidney inflammation and heart diseases. The presence of this extract reduced the lesive effects of SnCl2 upon E. coli AB1157 (proficient in DNA repair), BW9091 (deficient in the xthA gene) and BH110 (deficient in the xthA, nfo and fpg genes) cultures, and the deficient strains (BW9091 e BH110) were more sensible to this SnCl2 action than the proficient one. The substances in the extract could be acting as: (i) chelator of the stannous ions, avoiding the generation of FR, (ii) FR scavenger, protecting the cells against the oxidation, and/or (iii) an oxidant compound acting upon the stannous ions, reducing the SnCl2 cytotoxicity. PMID:17531166

  17. Evaluation of bishexadecyltrimethyl ammonium palladium tetrachloride based dual functional colloidal carrier as an antimicrobial and anticancer agent.

    Science.gov (United States)

    Kaur, Gurpreet; Kumar, Sandeep; Dilbaghi, Neeraj; Kaur, Baljinder; Kant, Ravi; Guru, Santosh Kumar; Bhushan, Shashi; Jaglan, Sundeep

    2016-04-12

    We have developed a dual function carrier using bishexadecyltrimethyl ammonium palladium tetrachloride, which has anticancer as well as antibacterial activity, using a ligand insertion method with a simple and easy work procedure. The complex is prepared by a simple and cost effective method using hexadecyltrimethyl ammonium chloride and palladium chloride under controlled stoichiometry. Herein, we report the aggregation (self assembly) of the metallosurfactant having palladium as a counter ion, in aqueous medium along with its binding affinity with bovine serum albumin. The palladium surfactant has exhibited excellent antimicrobial efficacy against fungus and bacteria (both Gram-positive and Gram-negative bacteria). Cytotoxicity of palladium surfactant against cancerous (Human leukemia HL-60, pancreatic MIA-Pa-Ca-2 and prostate cancer PC-3) and healthy cells (fR2 human breast epithelial cells) was also evaluated using MTT assay. The present dual functional moiety shows a low IC50 value and has potential to be used as an anticancer agent. Our dual function carrier which itself possesses antimicrobial and anticancer activity represents a simple and effective system and can also be utilized as a drug carrier in the future. PMID:26961498

  18. Physicochemical and friccohesity study of glycine, L-alanine and L-phenylalanine with aqueous methyltrioctylammonium and cetylpyridinium chloride from T = (293.15 to 308.15) K

    International Nuclear Information System (INIS)

    Graphical abstract: Figure depicts response of amino acids towards cationic surfactants in aqueous solution at constant temperatures. Apparent isentropic compressibilities at infinite dilution (κs,ϕ0/1012 m5 · N−1 · mol−1) for amino acids are as L-Ala aq.CPC > aq.MTOAC. • Positive Vϕ0 inferred stronger solute–solvent interactions. • Glycine and L-phenylalanine transfer volumes are positive. • κs,ϕ0 of glycine and L-phenylalanine with surfactants > with water. • Weaker electrostriction produced positive Δκs,ϕ0 for glycine and L-phenylalanine. -- Abstract: Density ρ, sound velocity u, viscosity η, apparent molar volume Vϕ, isentropic compressibility κs, and apparent molar isentropic compressibility κs,ϕ of glycine, L-alanine and L-phenylalanine: (0.05 to 0.15 mol · kg−1) with water, 0.002 mol · kg−1 aqueous methyltrioctylammonium chloride (MTOAC) and cetylpyridinium chloride (CPC) are reported at T = (293.15, 298.15, 303.15 and 308.15) K. The data were regressed against composition and regression constants: apparent molar volume at infinite dilution Vϕ0, apparent molar isentropic compressibility at infinite dilution κs,ϕ0 and viscosity B-coefficient are studied. Surface tension γ and friccohesity σ data were calculated from density, pendant drop number and viscous flow time. The Vϕ0 values are found as Vϕ(gly,l-phalwithwater)0 ϕ(gly,l-phalwithsurfactatnt)0, Vϕ(l-alawithsurfactatnt)0 ϕ(l-alawithwater)0 and κs,ϕ0 values as κϕ(gly,l-phalwithwater)0 ϕ(gly,l-phalwithsurfactatnt)0, κϕ(l-alawithsurfactatnt)0 ϕ(l-alawithwater)0. Surface tension of the solvents are found as water > CPC > MTOAC. Amino acids with surfactants have produced higher friccohesity than with water whereas the friccohesityof amino acids with water and surfactants is found as L-phal > L-Ala > gly over the entire temperature range but with CPC at T = 298.15 K, the order is L-phal > gly > L-Ala. The variations in physicochemical data with temperature

  19. Comparative Study of Laterite and Bentonite Based Organoclays: Implications of Hydrophobic Compounds Remediation from Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    Muhammad Nafees

    2013-01-01

    Full Text Available Four cost effective organoclays were synthesized, characterized, and studied for the sorption of hydrophobic compounds (edible oil/grease and hydrocarbon oil from aqueous solutions. Organoclays were prepared by cation exchange reaction of lattice ions (present onto the surface of laterite and bentonite clay minerals with two surfactants, hexadecyl trimethyl ammonium chloride (HDTMA-Cl and tetradecyl trimethyl ammonium bromide (TDTMA-Br. Fourier transform infrared spectroscopy and scanning electron microscopy were used for the characterization of synthesized organoclays. It was found that the amount of surfactant loading and the nature of the surfactant molecules used in the syntheses of organoclay strongly affect the sorption capacity of the clay mineral. Further, it was found that both the laterite and bentonite based organoclays efficiently removed the edible and hydrocarbon oil content from lab prepared emulsions; however, the adsorption capacity of clay mineral was greatly influenced by the nature of hydrophobic compounds as well.

  20. Influence of Ammonium Salts and Cane Molasses on Growth of Alcaligenes eutrophus and Production of Polyhydroxybutyrate

    OpenAIRE

    Beaulieu, M.; Beaulieu, Y.; Melinard, J.; Pandian, S.; GOULET, J.

    1995-01-01

    The production of polyhydroxybutyrate (PHB) by Alcaligenes eutrophus DSM 545 was studied in a synthetic medium with 3% glucose at pH 7.0 supplemented with several ammonium substrates and cane molasses. Growth was measured by dry cell weight, and the PHB content was measured by gas chromatography. The effects of ammonium sources such as sulfate, nitrate, phosphate, and chloride salts and those of different ammonium sulfate concentrations were evaluated. The best growth and PHB production were ...

  1. Synthesis, characterization, and self-assembly with plasmid DNA of a quaternary ammonium derivative of pectic galactan and its fluorescent labeling for bioimaging applications.

    Science.gov (United States)

    Chintakunta, Ramesh; Buaron, Nitsa; Kahn, Nicole; Moriah, Amana; Lifshiz, Rinat; Goldbart, Riki; Traitel, Tamar; Tyler, Betty; Brem, Henry; Kost, Joseph

    2016-10-01

    Quaternized derivatives of pectic galactan (QPG) were synthesized by a reaction of pectic galactan (PG) with 3-chloro-2-hydroxypropyl trimethyl ammonium chloride (CHPTAC) in the presence of aqueous sodium hydroxide solution under mild reaction conditions. The results showed that the concentration of CHPTAC and NaOH has great impact on the quaternization reaction. QPG was found to interact electrostatically with plasmid DNA in aqueous solution to form complexes in globular condensed morphology in a nanometer scale size ranging from 60 to 160nm. Complexes formed with QPG fluorescently labeled with 5-DTAF (QPG-5-DTAF) were introduced to the C6 rat glioma cell line, and were found to be able to enter the cell and approach the nucleus within 24h. The results suggest that this type of modified natural polysaccharide may have an advantage as a biocompatible and biodegradable gene delivery carrier and furthermore may serve as a cell specific carrier. PMID:27312642

  2. Effect of secondary structure on the interactions of peptide T4 LYS (11-36) in mixtures of aqueous sodium chloride and 2,2,2,-Trifluoroethanol

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Camille O.; Spiegelberg, Susanne; Prausnitz, John M.; Blanch, Harvey W.

    2001-10-01

    The potential of mean force for protein-protein interactions is key to the development of a statistical-mechanical model for salt-induced protein precipitation and crystallization, and for understanding certain disease states, including cataract formation and {beta}-amyloid pathology in Alzheimer's disease. Fluorescence anisotropy provides a method for quantitative characterization of intermolecular interactions due to reversible association. Monomer-dimer equilibria for the peptide T4 LYS(11-36) were studied by fluorescence anisotropy. This peptide, derived from the {beta}-sheet region of the T4 lysozyme molecule, has the potential to form amyloid fibrils. 2,2,2-trifluoroethanol (TFE) induces a change in peptide secondary structure, and was used in aqueous solutions at concentrations from 0 to 50% (v/v) at 25 and 37 C to examine the role of peptide conformation on peptide-peptide interactions. The association constant for dimerization increased with rising TFE concentration and with falling temperature. The peptide-peptide potential of mean force was computed from these association constants. Circular-dichroism measurements showed that the secondary structure of the peptide plays an important role in these strong attractive interactions due to intermolecular hydrogen-bond formation and hydrophobic interactions.

  3. Studies on the Extraction of Gold(I) Cyanide by Quaternary Ammonium Salt Using 198Au as Tracer

    Institute of Scientific and Technical Information of China (English)

    ZHANGTianxi; CHENJing; 等

    2002-01-01

    The solvent extraction of KAu(CN)2 from alkaline solution by quaternary ammonium salts (trialkylmethylammonium chloride or cetyltrimethylammonium bromide) waw investigated by means of 198Au radioactive tracer method. Various parameters,such as the gold (I) concentration in aqueous phase,the modiffer,emulsifiation at the interface of two phases, and phase ratio used in the extraction of gold (I) were studied. The results demonstrate that almost all gold (I) in the aqueous phase was practically extracted into the organic phase. The water content in the organic phase decreased significantly with increase of gold (I) concentration using long chain alcohol as modifier,in contrast with the system with tributyl phosphate (TBP) as modifier. Emulsification at the interface of two phases decreases with an increase of modifier concentration in the organic phase or with the addition of a small amount of lysozyme into the aqueous phase. The method with 198Au tracer can be directly used to determine the Au(I) concentration both in aqueous and organic phases, which is especially suitable for the low concentration of Au(I).

  4. Removal of iron contaminant from zirconium chloride solution

    International Nuclear Information System (INIS)

    This patent describes a process for eliminating iron contaminant from an aqueous zirconium chloride solution that has been contaminated with FeCl3 in a plant in which zirconium and hafnium chloride solutions are separated by a main MINK solvent extraction system and the FeCl3 is normally removed from the zirconium chloride solution by a secondary MINK solvent extraction system

  5. Photoelectrocatalysis based on Ti/TiO2 nanotubes removes toxic properties of the azo dyes Disperse Red 1, Disperse Red 13 and Disperse Orange 1 from aqueous chloride samples.

    Science.gov (United States)

    Ferraz, E R A; Oliveira, G A R; Grando, M D; Lizier, T M; Zanoni, M V B; Oliveira, D P

    2013-07-30

    This work describes the efficiency of photoelectrocatalysis based on Ti/TiO2 nanotubes in the degradation of the azo dyes Disperse Red 1, Disperse Red 13 and Disperse Orange 1 and to remove their toxic properties, as an alternative method for the treatment of effluents and water. For this purpose, the discoloration rate, total organic carbon (TOC) removal, and genotoxic, cytotoxic and mutagenic responses were determined, using the comet, micronucleus and cytotoxicity assays in HepG2 cells and the Salmonella mutagenicity assay. In a previous study it was found that the surfactant Emulsogen could contribute to the low mineralization of the dyes (60% after 4 h of treatment), which, in turn, seems to account for the mutagenicity of the products generated. Thus this surfactant was not added to the chloride medium in order to avoid this interference. The photoelectrocatalytic method presented rapid discoloration and the TOC reduction was ≥87% after 240 min of treatment, showing that photoelectrocatalysis is able to mineralize the dyes tested. The method was also efficient in removing the mutagenic activity and cytotoxic effects of these three dyes. Thus it was concluded that photoelectrocatalysis was a promising method for the treatment of aqueous samples.

  6. Electron transfer between excited states of some sulfonated phtha-locyanines and tyrosine as well as trptophan in homogeneous aqueous solution and aqueous micellar media

    Institute of Scientific and Technical Information of China (English)

    张先付; 许慧君; 沈涛

    1995-01-01

    Rate constants for electron transfer between excited states of several tetrasulfonated phthalocyanines (MTSPC, M = H2, Zn, ClAl, ClGa) and tyrosine or trptophan have been measured in homogeneous aqueous and aqueous micellar media. Cationic micelles formed by surfactant cetyl trimethyl ammonium chloride (CTAC) promote the electron transfer reaction, whereas neutral micelles formed by Triton X-100 depress this process. The calculated free energy change shows that phthalocyanines act as electron donors in the electron transfer reaction of its excited singlet states with tyrosine or trptophan (Type Is), whereas they act as electron acceptors in the reaction of its excited triplet states with tyrosine or trptophan (type IT). The two different electron transfer processes involving singlet and triplet of sensitizer respectively compete with each other and form different intermediates which may induce the formation of different products. Factors that govern the importance of Type Is in the whole reaction includ

  7. 乙醇-硫酸铵双水相萃取镉-碘化钾-罗丹明B离子缔合物%Extraction of cadmium-potassium iodide-rhodamine B ion association complex by alcohol-ammonium sulfate aqueous two-phase

    Institute of Scientific and Technical Information of China (English)

    曾云; 覃事栋; 姚康康; 王影; 肖苗

    2012-01-01

    In the presence of ammonium sulphate, the extraction behavior of Cd (Ⅱ) based on potassium iodide-Rhodamine B-alcohol system was studied and the optimal condition of phase separation was selected. Results showed that in the pH1 ~3 media, the extraction rate of [CdI4]2- by alcohol-ammonium sulfate aqueous two-phase system is only 35.5% , and the ion association complex, which is formed by adding rhodamine B, can be extracted completely by the aqueous two-phase system. In the system, Cd2+ can be dissociated completely from Zn2+, Fe3+, Co2+, Cu2+, and Ni2+.%研究了在( NH4) 2SO4存在下,碘化钾-罗丹明B-乙醇体系萃取Cd(Ⅱ)的行为及最佳分相条件.实验表明,在pH 1~3时,乙醇-( NH4 )2SO4双水相体系对[ CdI4]2-络阴离子的萃取率只有35.5%;加入罗丹明B后,该体系能完全萃取镉-碘化钾-罗丹明B形成的离子缔合物,而干扰离子Zn2+、Fe3+、Co2+、Cu2+、Ni2+不被萃取,实现Cd2+与上述离子的分离.

  8. Adamantane-1-ammonium acetate

    Directory of Open Access Journals (Sweden)

    Elise J. C. de Vries

    2011-06-01

    Full Text Available In the title compound, C10H18N+·C2H3O2−, the ammonium H atoms of the cation are linked to three acetate anions via N—H...O hydrogen bonds, forming a chain structure extending along the b axis.

  9. Determination of aluminum in aluminum electrolyte by EDTA back titration with ethanol-cuprous chloride-ammonium chloride-hydrochloric acid complex solvent separation%乙醇-氯化亚铜-氯化铵-盐酸复合溶剂分离-EDTA返滴定法测定铝电解质中单质铝

    Institute of Scientific and Technical Information of China (English)

    蒲秋梅; 任凤莲; 曹福悦

    2011-01-01

    新型低温铝电解质体系物相组成复杂,单质铝的分离测定尤为困难.本文采用高选择性复合溶剂乙醇-氯化亚铜-氯化铵-盐酸(ECAH)直接分离后测定铝电解质中单质铝,成功解决了单质铝与其它铝的化合物分离困难的问题,有效降低了铝电解质溶样时铝的氟化物的微溶效应带来的误差,为铝电解质中单质铝的物相分析提供了可靠的研究方案.采用经典ED-TA络合返滴定法测得铝电解质样品中单质铝含量,加标回收率在97%~103%之间,RSD(n=6)为1.1%和1.5%.测定结果和Al-CAS-OP-CPC四元络合光度法测定结果进行比对,结果一致.%It was particularly difficult to separate and determine aluminum in new low-temperature aluminum electrolyte system because of its complicated components. In this paper, aluminum in aluminum electrolyte was directly separated and determined using high-selectivity ethanol -cuprous chlorideammomum chloride-hydrochloric acid (ECAH) as complex solvent. This method successfully settled the problem of difficult separation of aluminum from aluminum compounds, effectively reduced the determination error introduced by slight soluble effect of fluoride of aluminum during the dissolution of aluminum electrolyte, and provided a reliable research method for the phase analysis of aluminum in aluminum electrolyte. Aluminum in aluminum electrolyte samples was determined by classic EDTA complexing back titration method. The standard addition recoveries were 97%-103 %, and the relative standard deviations (RSD, n=6) were 1. 1 % and 1. 5 %, respectively. The determination results were in good agreement with those obtained by Al-CAS-OP-CPC quaternary complex photometry.

  10. Preparation of the chitosan grafted poly (quaternary ammonium)/Fe3O4 nanoparticles and its adsorption performance for food yellow 3.

    Science.gov (United States)

    Yu, Chen; Geng, Jianqiang; Zhuang, Yunxia; Zhao, Jian; Chu, Liqiu; Luo, Xiaoxuan; Zhao, Ying; Guo, Yanwen

    2016-11-01

    Chitosan and its derivatives can be used to modify magnetic materials to promote the adsorption properties of the magnetic materials and avoid the weakness of chitosan and its derivatives. In the present study, chitosan grafted poly(trimethyl allyl ammonium chloride) (CTS-g-PTMAAC) was prepared by graft copolymerization; then it was coated on the surfaces of the sodium citrate coated Fe3O4 nanoparticles (SC-Fe3O4) to prepare a novel composite CTS-g-PTMAAC/SC-Fe3O4 magnetic nanoparticles, with which possesses abundant surface positive charges. The structure and properties of the CTS-g-PTMAAC/SC-Fe3O4 composite magnetic nanoparticles were characterized by FTIR, TEM, VSM, and zeta potential. The dye adsorption characteristics of the CTS-g-PTMAAC/SC-Fe3O4 nanoparticles were determined using the food yellow 3 aqueous solutions as a model food effluent. Effect of pH of the dye solution on the adsorption of food yellow 3 was determined and compared with N-2-hydroxylpropyl trimethyl ammonium chloride chitosan coated sodium citrate-Fe3O4 (CTS-g-HTCC/SC-Fe3O4) composite magnetic nanoparticles. The adsorption kinetics, adsorption isotherms, adsorption thermodynamics, and desorption and reusability of the magnetic nanoparticles were investigated. PMID:27516279

  11. Preparation of the chitosan grafted poly (quaternary ammonium)/Fe3O4 nanoparticles and its adsorption performance for food yellow 3.

    Science.gov (United States)

    Yu, Chen; Geng, Jianqiang; Zhuang, Yunxia; Zhao, Jian; Chu, Liqiu; Luo, Xiaoxuan; Zhao, Ying; Guo, Yanwen

    2016-11-01

    Chitosan and its derivatives can be used to modify magnetic materials to promote the adsorption properties of the magnetic materials and avoid the weakness of chitosan and its derivatives. In the present study, chitosan grafted poly(trimethyl allyl ammonium chloride) (CTS-g-PTMAAC) was prepared by graft copolymerization; then it was coated on the surfaces of the sodium citrate coated Fe3O4 nanoparticles (SC-Fe3O4) to prepare a novel composite CTS-g-PTMAAC/SC-Fe3O4 magnetic nanoparticles, with which possesses abundant surface positive charges. The structure and properties of the CTS-g-PTMAAC/SC-Fe3O4 composite magnetic nanoparticles were characterized by FTIR, TEM, VSM, and zeta potential. The dye adsorption characteristics of the CTS-g-PTMAAC/SC-Fe3O4 nanoparticles were determined using the food yellow 3 aqueous solutions as a model food effluent. Effect of pH of the dye solution on the adsorption of food yellow 3 was determined and compared with N-2-hydroxylpropyl trimethyl ammonium chloride chitosan coated sodium citrate-Fe3O4 (CTS-g-HTCC/SC-Fe3O4) composite magnetic nanoparticles. The adsorption kinetics, adsorption isotherms, adsorption thermodynamics, and desorption and reusability of the magnetic nanoparticles were investigated.

  12. Enhanced dispersion stability and mobility of carboxyl-functionalized carbon nanotubes in aqueous solutions through strong hydrogen bonds

    Energy Technology Data Exchange (ETDEWEB)

    Bahk, Yeon Kyoung; He, Xu; Gitsis, Emmanouil; Kuo, Yu-Ying [ETH Zurich, Institute of Environmental Engineering (Switzerland); Kim, Nayoung [EMPA, Building Energy Materials and Components (Switzerland); Wang, Jing, E-mail: jing.wang@ifu.baug.ethz.ch [ETH Zurich, Institute of Environmental Engineering (Switzerland)

    2015-10-15

    Dispersion of carbon nanotubes has been heavily studied due to its importance for their technical applications, toxic effects, and environmental impacts. Common electrolytes, such as sodium chloride and potassium chloride, promote agglomeration of nanoparticles in aqueous solutions. On the contrary, we discovered that acetic electrolytes enhanced the dispersion of multi-walled carbon nanotubes (MWCNTs) with carboxyl functional group through the strong hydrogen bond, which was confirmed by UV–Vis spectrometry, dispersion observations and aerosolization-quantification method. When concentrations of acetate electrolytes such as ammonium acetate (CH{sub 3}CO{sub 2}NH{sub 4}) and sodium acetate (CH{sub 3}CO{sub 2}Na) were lower than 0.03 mol per liter, MWCNT suspensions showed better dispersion and had higher mobility in porous media. The effects by the acetic environment are also applicable to other nanoparticles with the carboxyl functional group, which was demonstrated with polystyrene latex particles as an example.

  13. Enhanced dispersion stability and mobility of carboxyl-functionalized carbon nanotubes in aqueous solutions through strong hydrogen bonds

    International Nuclear Information System (INIS)

    Dispersion of carbon nanotubes has been heavily studied due to its importance for their technical applications, toxic effects, and environmental impacts. Common electrolytes, such as sodium chloride and potassium chloride, promote agglomeration of nanoparticles in aqueous solutions. On the contrary, we discovered that acetic electrolytes enhanced the dispersion of multi-walled carbon nanotubes (MWCNTs) with carboxyl functional group through the strong hydrogen bond, which was confirmed by UV–Vis spectrometry, dispersion observations and aerosolization-quantification method. When concentrations of acetate electrolytes such as ammonium acetate (CH3CO2NH4) and sodium acetate (CH3CO2Na) were lower than 0.03 mol per liter, MWCNT suspensions showed better dispersion and had higher mobility in porous media. The effects by the acetic environment are also applicable to other nanoparticles with the carboxyl functional group, which was demonstrated with polystyrene latex particles as an example

  14. Synthesis, characterization, and bioactivity of rosin quaternary ammonium salt derivatives

    Directory of Open Access Journals (Sweden)

    Tao Liang

    2013-02-01

    Full Text Available Two series of rosin quaternary ammonium salts (QAS were synthesized using the same path. The structure of the target products was characterized by HPLC, MS, IR, and 1HNMR, and the bioactivity was determined by filter paper method using Trametes versicolor (white-rot fungus and Gloeophyllum trabeum (brown-rot fungus, which are two kinds of general wood decay fungi in nature. The results showed that all compounds tested had a satisfactory anti-fungal effect at the molarity of 0.025 mmol/mL. Hereinto, acrylpimaric Gemini QAS had better bioactivity than dehydrogenated or tetrahydrogenated rosin QAS against Trametes versicolor. To this fungus, quaternary ammonium groups, which wraps up the membrane of microorganism and disrupts the balance in cell membrane, plays the leading role for its bioactivity. To Gloeophyllum trabeum, the inhibition activity of acrylpimaric QAS and dehydrogenated rosin QAS are almost at the same level and larger than tetrahydrogenated rosin QAS, so we conclude that both quaternary ammonium group and aromatic group play important roles. Compared with dodecyl dimethyl benzyl ammonium chloride (1227, which is a commercially available quaternary ammonium salt type fungicide, acrylpimaric acid quaternary ammonium salts have approximate bioactivity against Gloeophyllum trabeum. In conclusion, rosin derivatives with functional groups would do well in wood preservative applications.

  15. Removal of ammonium from municipal landfill leachate using natural zeolites.

    Science.gov (United States)

    Ye, Zhihong; Wang, Jiawen; Sun, Lingyu; Zhang, Daobin; Zhang, Hui

    2015-01-01

    Ammonium ion-exchange performance of the natural zeolite was investigated in both batch and column studies. The effects of zeolite dosage, contact time, stirring speed and pH on ammonium removal were investigated in batch experiments. The result showed that ammonium removal efficiency increased with an increase in zeolite dosage from 25 to 150 g/L, and an increase in stirring speed from 200 to 250 r/min. But further increase in zeolite dosage and stirring speed would result in an unpronounced increase of ammonium removal. The optimal pH for the removal of ammonium was found as 7.1. In the column studies, the effect of flow rate was investigated, and the total ammonium removal percentage during 180 min operation time decreased with the flow rate though the ion-exchange capacity varied to a very small extent with the flow rate ranging from 4 to 9 mL/min. The spent zeolite was regenerated by sodium chloride solution and the ammonia removal capacity of zeolite changed little or even increased after three regeneration cycles. PMID:26510611

  16. 聚天冬氨酸与十四烷基二甲基苄基氯化铵等复配物的缓蚀阻垢杀菌性能%Scale, Corrosion Inhibitions and Anti-Bacterial Performances of the Combinations of Polyaspartic Acid and Tetradecyl Dimethyl Benzyl Ammonium Chloride

    Institute of Scientific and Technical Information of China (English)

    刘芳; 常新; 董文文; 姜慧超; 张玉娇

    2013-01-01

    采用旋转挂片法、碳酸钙沉积法和平板计数法,分别考察了十四烷基二甲基苄基氯化铵(1427)、聚天冬氨酸(PASP)和氨基三亚甲基膦酸(ATMP)水处理剂在循环冷却水中的缓蚀、阻垢和杀菌性能,并将它们与锌盐复配使用,通过正交实验筛选出具有良好缓蚀、阻垢和杀菌性能的复合配方.结果表明,当循环冷却水中ATMP、PASP、1427和锌盐的质量浓度分别为40、20、80、2 mg/L时,该复配剂可获得最佳性能,对碳钢的缓蚀率和相应的阻垢率均高于91%,杀菌率可达98%以上,实现了缓蚀、阻垢和杀菌3种功效.%The corrosion, scale inhibitions and anti-bacterial performances of tetradecyl dimethyl benzyl ammonium chloride(1427) , polyaspartic acid (PASP) , amino trimethylene phosphonic acid (ATMP) water treatment chemicals in circulating cooling water were investigated by using rotary coupon corrosion test, carbonate precipitation process and flat colony counting method. A combination formula composed of 1427, PASP, ATMP and zinc salt with high performances of corrosion, scale inhibitions and anti-bacterial was screened by orthogonal experiment. The results showed that when the combination water treatment agent composed of 40 mg/L ATMP, 20 mg/L PASP, 80 mg/L 1427 and 2 mg/L zinc salt was used in circulating cooling water, the corrosion inhibition rate for carbon steel exceeded 91%, the corresponding scale inhibition rate exceeded 91% , and the bactericidal rate reached above 98%. The multi-function of corrosion inhibition, scale inhibition and sterilization was achieved.

  17. N,N,N-三乙基-2-羟基-3-月桂酰氧基丙基氯化铵的合成与性能%Synthesis and Property of N,N,N-3-Ethyl-2-Hydroxy-3-Lauroyloxy Propyl Triethyl Ammonium Chloride

    Institute of Scientific and Technical Information of China (English)

    张荣明; 张振宇; 马冬晖; 郝玉兰; 任洪凯

    2011-01-01

    The N,N,N-3-ethyl-2-hydroxy-3-1auroyloxy propyl triethyl ammonium chloride (CELA) was synthesized with lauric acid, epichlorohydrin and triethylamine as the main starting materials.The main reaction include esterification and quaternization.The reaction process was studied and the result as follows, the esterification conditions: n(lauric acid)/n (epichlorohydrin)= 1.0: 1.2, reaction temperature was 80 ℃, reaction time was 8 h, benzyl triethylammonium chloride (TEBAC) was the catalyst and the lauric acid - 2 - hydroxy 3 - chlorine- propyl ester yield rate is 98.7%.The quaternization conditions.n(intermediate)/n(triethylamine)= 1.0:1.8, the temperature was 80 ℃, isopropyl alcohol was the solvent, reaction time was 25 h,the active mass fraction of purified production is 95.0%.The product was identified by FT-IR and the property was tested.The cmc of CELA solution was 0.21 mmol/L and surface tension was 33.27 mN/m at 25 ℃.The antiswelling rate to kaoline is 80% when the mass concentration of CEIA was 20 g/L.Corrosion mitigation rate to A3 steel is 87.5% when the mass concentration of CELA was 40 mg/L.%以月桂酸、环氧氯丙烷和三乙胺为主要原料,经酯化、季铵化合成了N,N,N-三乙基-2-羟基-3-月桂酰氧基丙基氯化铵(CELA),对CELA的合成进行了研究.结果表明,酯化反应条件:n(月桂酸)/n(环氧氯丙烷)=1.0:1.2,反应温度为80℃,反应时间为8 h,苄基三乙基氯化铵(TEBAC)为催化剂,3-氯-2-羟基-月桂酸丙酯的收率达到98.7%;季铵化反应条件:n(中间体)/n(三己胺)=1.0;1.8,反应温度为80℃,以异丙醇作溶剂,反应时间为25 h,得到粗产品经乙醇-丙酮混合溶剂提纯后活性物的质量分数可达到95.0%以上,对所得产品进行红外表征及性能测试.25℃时其水溶液的临界胶束浓度为0.21 mmol/L,CELA的表面张力为33.27 mN/m,CELA质量浓度为20 g/L时对高岭土防膨率达到80%,40 mg/L时对A3碳钢的缓蚀率可达到87.5%.

  18. Extração simultânea de alumínio, cálcio, magnésio, potássio e sódio do solo com solução de cloreto de amônio Simultaneous extraction of aluminum, calcium, magnesium, potassium, and sodium with ammonium chloride solution

    Directory of Open Access Journals (Sweden)

    R. C. Boeira

    2004-10-01

    samples used were from Northeastern Brazil fruit growing region and from the Embrapa Environment Experimental Station, located in Jaguariúna County, São Paulo State. The employed methods were: (a simultaneous extraction of the five cations with a 1 mol L-1 NH4Cl; (b extraction of Ca, Mg, and Al with 1 mol L-1 KCl; and (c extraction of K and Na with the Mehlich-1 solution. The NH4Cl solution has a higher Mg extraction capacity than KCl, but they present similar Ca and Al extraction ability. The NH4Cl solution extracted more K and Na than the Mehlich-1 solution. It is concluded that the ammonium chloride solution is a convenient alternative for the extraction of exchangeable Al, Ca, Mg, K, and Na from soils.

  19. Highly efficient hydrogen storage system based on ammonium bicarbonate/formate redox equilibrium over palladium nanocatalysts.

    Science.gov (United States)

    Su, Ji; Yang, Lisha; Lu, Mi; Lin, Hongfei

    2015-03-01

    A highly efficient, reversible hydrogen storage-evolution process has been developed based on the ammonium bicarbonate/formate redox equilibrium over the same carbon-supported palladium nanocatalyst. This heterogeneously catalyzed hydrogen storage system is comparable to the counterpart homogeneous systems and has shown fast reaction kinetics of both the hydrogenation of ammonium bicarbonate and the dehydrogenation of ammonium formate under mild operating conditions. By adjusting temperature and pressure, the extent of hydrogen storage and evolution can be well controlled in the same catalytic system. Moreover, the hydrogen storage system based on aqueous-phase ammonium formate is advantageous owing to its high volumetric energy density.

  20. Diffusion behavior of chloride ions in concrete

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, T.; Gjoerv, O.E. [Norwegian Univ. of Science and Technology, Trondheim (Norway). Div. of Building Materials

    1996-06-01

    In the present paper, an analysis of the diffusion behavior of chloride ions in concrete is presented. In concentrated electrolytic aqueous solutions such as seawater or that typically used in laboratory experiments, the effect of ionic interaction may significantly reduce the chemical potential and thus the driving force of the diffusing species. Because of different drift velocities of the cations and chloride ions in the solution, the lagging motion of the cations will also retard the drift velocity of the chlorides. In addition, both the electrical double layer forming on the solid surface and the chemical binding may significantly interfere with the transport of the chloride ions. As a result, the diffusion behavior of the chloride ions in concrete is a more complex and complicated transport process than what can be described by Fick`s law of diffusion.

  1. Effect of quaternary ammonium salts on flotation behavior of aluminosilicate minerals

    Institute of Scientific and Technical Information of China (English)

    ZHAO Sheng-gui; ZHONG Hong; LIU Guang-yi

    2007-01-01

    The electrokinetic properties and flotation of diaspore, kaolinite, pyrophyllite and illite with quaternary ammonium salts collectors were studied. The results of flotation tests show that the collecting ability of quaternary ammonium salts for the four minerals is in the order(from strong to weak) of octadecyl dimethyl benzyl ammonium chloride(ODBA), cetyl trimethyl ammonium bromide(CTAB), dodecyl trimethyl ammonium chloride(DTAC). Under the condition of alkalescence, it is possible to separate the diaspore from the silicate minerals such as kaolinite, illite and pyrophyllite using quaternary ammonium salts as collector. Isoelectric points (IEP) of diaspore, kaolinite, pyrophyllite and illite are pH=6.0, 3.4, 2.3 and 3.2, respectively. Quaternary ammonium salts can change ζ-potential of the aluminosilicate minerals obviously. The flotation mechanisms were explained by ζ-potential and Fourier transform infrared spectrum (FT-IR) measurements. The results demonstrate that only electrostatic interaction takes place between aluminosilicate minerals (diaspore, kaolinite, pyrophyllite and illite) and quaternary ammonium salts.

  2. Microwave Mapping Demonstration Using the Thermochromic Cobalt Chloride Equilibrium

    Science.gov (United States)

    Nguyen, Vu D.; Birdwhistell, Kurt R.

    2014-01-01

    An update to the thermochromic cobalt(II) chloride equilibrium demonstration is described. Filter paper that has been saturated with aqueous cobalt(II) chloride is heated for seconds in a microwave oven, producing a color change. The resulting pink and blue map is used to colorfully demonstrate Le Châtelier's principle and to illuminate the…

  3. 改性玉米芯生物碳对氨氮的吸附特性%Adsorption characters of ammonium-nitrogen in aqueous solution by modified corn cob biochars

    Institute of Scientific and Technical Information of China (English)

    张扬; 李子富; 张琳; 赵瑞雪

    2014-01-01

    以农业废弃物玉米芯为原料,采用限氧热解法(600℃)制备生物碳,分别采用盐酸、双氧水和硝酸对其进行改性。通过元素分析、FTIR、BET-N2、Boehm滴定法及扫描电镜等手段表征了生物碳的组成与结构。通过序批实验,研究了生物碳对氨氮的吸附性能及影响因素,探讨了其吸附机理,为生物碳在污水处理中更好的应用提供参考。结果表明,未改性生物碳和经过盐酸、硝酸和双氧水改性的生物碳其比表面积分别为17.74、212.89、208.74和209.15 m2·g-1;表面酸性含氧官能团数量分别为0.11、0.95、5.73和2.15 mmol·g-1。等温吸附曲线符合Freundlich方程。动力学研究表明,生物碳对氨氮吸附行为符合准二级动力学方程。且经硝酸改性生物碳由于表面酸性含氧官能团的增加,其对氨氮的吸附能力显著提高。%Biochars produced by pyrolysis of corn cob(600℃) which is agricultural waste, and modified with hydrochloric acid, hydrogen peroxide and nitric acid separately. Elemental analysis, BET-N2 surface area (SA), scanning electron microscopy, Boehm titration and FTIR spectra were used to characterized their physicochemical properties. Batch experiments were conducted to investigate ammonium adsorption process of corn cob biochars. The results revealed that acid modification can significantly improve biochars’ specific surface area, which were 17.74, 212.89, 208.74 and 209.15 m2·g-1 for without modified and modified with HCl, HNO3 and H2O2 samples, respectively;while the amounts of acidic functional groups were 0.11, 0.95, 5.73 and 2.15 mmol·g-1, respectively. The results for fitting experimental data of adsorption process with isotherm models showed that it is better for Freundlich isotherm model than Langmuir isotherm model. Moreover, the adsorption process can be well described by pseudo-second-order kinetic model. The results obtained demonstrated that biochars

  4. Ammonium diphosphitoindate(III

    Directory of Open Access Journals (Sweden)

    Farida Hamchaoui

    2013-04-01

    Full Text Available The crystal structure of the title compound, NH4[In(HPO32], is built up from InIII cations (site symmetry 3m. adopting an octahedral environment and two different phosphite anions (each with site symmetry 3m. exhibiting a triangular–pyramidal geometry. Each InO6 octahedron shares its six apices with hydrogen phosphite groups. Reciprocally, each HPO3 group shares all its O atoms with three different metal cations, leading to [In(HPO32]− layers which propagate in the ab plane. The ammonium cation likewise has site symmetry 3m.. In the structure, the cations are located between the [In(HPO32]− layers of the host framework. The sheets are held together by hydrogen bonds formed between the NH4+ cations and the O atoms of the framework.

  5. Hygroscopic and phase separation properties of ammonium sulfate/organic/water ternary solutions

    Directory of Open Access Journals (Sweden)

    M. A. Zawadowicz

    2015-03-01

    Full Text Available Atmospheric aerosol particles are often partially or completely composed of inorganic salts, such as ammonium sulfate and sodium chloride, and therefore exhibit hygroscopic properties. Many inorganic salts have well-defined deliquescence and efflorescence points at which they take up and lose water, respectively. Deliquescence and efflorescence of simple inorganic salt particles have been investigated by a variety of methods, such as IR spectroscopy, tandem mobility analysis and electrodynamic balance. Field measurements have shown that atmospheric aerosols are not typically pure inorganic salt, instead they often also contain organic species. There is ample evidence from laboratory studies that suggests that mixed particles exist in a phase-separated state, with an aqueous inorganic core and organic shell. Although phase separation has not been measured in situ, there is no reason it would not also take place in the atmosphere. Many recent studies have focused on microscopy techniques that require deposition of the aerosol on a glass slide, possibly changing its surface properties. Here, we investigate the deliquescence and efflorescence points, phase separation and ability to exchange gas-phase components of mixed organic and inorganic aerosol using a flow tube coupled with FTIR spectroscopy. Ammonium sulfate aerosol mixed with organic polyols with different O : C ratios, including 1,4-butanediol, glycerol, 1,2,6-hexanetriol, 1,2-hexanediol, and 1,5-pentanediol have been investigated. Those constituents correspond to materials found in the atmosphere in great abundance, and therefore, particles prepared in this study should mimic atmospheric mixed phase aerosol particles. The results of this study tend to be in agreement with previous microscopy experiments, with several key differences, which possibly reveal a size-dependent effect on phase separation in organic/inorganic aerosol particles.

  6. Evaluating Battery-like Reactions to Harvest Energy from Salinity Differences using Ammonium Bicarbonate Salt Solutions.

    Science.gov (United States)

    Kim, Taeyoung; Rahimi, Mohammad; Logan, Bruce E; Gorski, Christopher A

    2016-05-10

    Mixing entropy batteries (MEBs) are a new approach to generate electricity from salinity differences between two aqueous solutions. To date, MEBs have only been prepared from solutions containing chloride salts, owing to their relevance in natural salinity gradients created from seawater and freshwater. We hypothesized that MEBs could capture energy using ammonium bicarbonate (AmB), a thermolytic salt that can be used to convert waste heat into salinity gradients. We examined six battery electrode materials. Several of the electrodes were unstable in AmB solutions or failed to produce expected voltages. Of the electrode materials tested, a cell containing a manganese oxide electrode and a metallic lead electrode produced the highest power density (6.3 mW m(-2) ). However, this power density is still low relative to previously reported NaCl-based MEBs and heat recovery systems. This proof-of-concept study demonstrated that MEBs could indeed be used to generate electricity from AmB salinity gradients. PMID:27030080

  7. The ionic product of water in concentrated tetramethylammonium chloride solutions.

    Science.gov (United States)

    Sipos, P; Bódi, I; May, P M; Hefter, G T

    1997-04-01

    The ionic product of water, pK(w) = - log[H(+)][OH(-)] has been determined in aqueous solutions of tetramethylammonium chloride over the concentration range of 0.1-5.5 M at 25 degrees C using high-precision glass electrode potentiometric titrations. pK(w) data relating to aqueous potassium and sodium chlorides at ionic strengths up to 5 M are markedly lower than the tetramethylammonium chloride results. These differences are almost certainly due to weak associations between potassium and (especially) sodium and hydroxide ions.

  8. Enthalpy and entropy interaction parameters of sodium chloride with some monosaccharides in water

    Institute of Scientific and Technical Information of China (English)

    ZHUO; Kelei; WANG; Jianji; BAI; Guangyue; YAN; Haike; WANG

    2004-01-01

    Dilution enthalpies of sodium chloride and some monosaccharides (glucose, galactose, xylose, arabinose, and fructose) in water and mixing enthalpies of aqueous sodium chloride and these monosaccharide solutions were measured by using an improved precision semimicro-titration calorimeter. Transfer enthalpies of sodium chloride from water to aqueous saccharide solutions were evaluated as well as enthalpy interaction parameters of sodium chloride with these monosaccharides in water. Combined with Gibbs energy interaction parameters, entropy interaction parameters were also obtained. The results show that interactions of the saccharides with sodium chloride depend on the stereochemistry of saccharide molecules. These interaction parameters can identify stereochemical structure of saccharide molecules.

  9. Bifunctional polyacrylonitrile fiber-mediated conversion of sucrose to 5-hydroxymethylfurfural in mixed-aqueous systems.

    Science.gov (United States)

    Shi, Xian-Lei; Zhang, Min; Lin, Huikun; Tao, Minli; Li, Yongdan; Zhang, Wenqin

    2015-03-01

    A highly efficient catalytic system composed of a bifunctional polyacrylonitrile fiber (PANF-PA[BnBr]) and a metal chloride was employed to produce 5-hydroxymethylfurfural (HMF) from sucrose in mixed-aqueous systems. The promoter of PANF-PA[BnBr] incorporates protonic acid groups that promote the hydrolysis of the glycosidic bond to convert sucrose into glucose and fructose, and then catalyzes fructose dehydration to HMF, while the ammonium moiety may promote synergetically with the metal chloride the isomerization of glucose to fructose and transfer HMF from the aqueous to the organic phase. The detailed characterization by elemental analysis, FTIR spectroscopy, and SEM confirmed the rangeability of the fiber promoter during the modification and utilization processes. Excellent results in terms of high yield (72.8%) of HMF, superior recyclability (6 cycles) of the process, and effective scale-up and simple separation procedures of the catalytic system were obtained. Moreover, the prominent features (high strength, good flexibility, etc.) of the fibers are very attractive for fix-bed reactor. PMID:25573698

  10. Application of Liquid Emulsion Membrane Technique for the Removal of As(V) from Aqueous Solutions

    Science.gov (United States)

    Binnal, Prakash; Hiremath, Poornima G.

    2012-08-01

    Liquid emulsion membrane technique was used to remove As(V) from synthetic aqueous solutions. The emulsion was composed of Aliquat 336 as an extractant, commercial kerosene as a diluent and Span 80 (Sorbiton monooleate) as an emulsifying agent. Different types of internal phases were used, namely, sodium hydroxide, sodium carbonate, ammonium bicarbonate, sodium sulphate and sodium chloride. The effect of process parameters affecting extraction efficiency, such as, initial concentration of As(V) in feed solution, pH of feed solution, concentrations of Aliquat 336 and Span 80 in membrane phase, volume ratio of stripping phase to membrane phase, concentration of internal phase, type of internal phase, volume ratio of emulsion to feed, agitation speed during extraction and time of extraction was investigated. The optimum conditions for the extraction were determined. A maximum As(V) removal rate of 97.8 was observed under optimum conditions.

  11. Studies on the Extraction of Gold (Ⅰ) Cyanide by Quaternary Ammonium Salt Using 198Au as Tracer%用198Au示踪法研究季铵盐体系萃取金

    Institute of Scientific and Technical Information of China (English)

    张天喜; 周维金; 高宏成; 陈景; 吴瑾光

    2002-01-01

    The solvent extraction of KAu(CN)2 from alkaline solution by quaternary ammonium salts (trialkylmethylammonium chloride or cetyltrimethylammonium bromide) was investigated by means of 198Au radioactive tracer method. Various parameters, such as the gold (Ⅰ) concentration in aqueous phase, the modifier, emulsification at the interface of two phases, and phase ratio used in the extraction of gold (Ⅰ) were studied. The results demonstrate that almost all gold (Ⅰ) in the aqueous phase was practically extracted into the organic phase. The water content in the organic phase decreased significantly with increase of gold (Ⅰ) concentration using long chain alcohol as modifier, in contrast with the system with tributyl phosphate (TBP) as modifier. Emulsification at the interface of two phases decreases with an increase of modifier concentration in the organic phase or with the addition of a small amount of lysozyme into the aqueous phase. The method with 198Au tracer can be directly used to determine the Au(Ⅰ) concentration both in aqueous and organic phases, which is especially suitable for the low concentration of Au(Ⅰ).

  12. Development and use of thin film composite based positively charged nanofiltration membranes in separation of aqueous streams and nuclear effluents

    International Nuclear Information System (INIS)

    A new, positively charged, thin film composite (TFC) type nanofiltration membrane has been developed and studied for its use in various aqueous stream separations. The membrane, containing fixed quaternary ammonium moieties, was developed by insitu interfacial polymerization of a functionalized amine (polyethyleneimine) and terephthaloyl chloride on a suitable base membrane. The nature of the charge on the membrane was established by ATR FT IR spectroscopy and was estimated by determination of its ion exchange capacity. The membrane was tested for its performance in single solute feed systems containing salts of various combinations of univalent and bivalent ions (NaCl, Na2SO4, CaCl2 and MgSO4) in test cell as well as in 2512 spiral modules. The membrane gave differential separation profile for these solutes with high rejection for CaCl2 and low rejection for Na2SO4 due to positive charge on the membrane and the type of charge constituting the salts. The membrane was also used for separation of simulated effluent solution containing uranyl nitrate in combination with ammonium nitrate which is a common effluent generated in nuclear industry. Here also the membrane gave differential separation profile for uranyl nitrate and ammonium nitrate in their mixture by concentrating the former salt and passing the later. This helped separation of these two solutes in the mixture into two different streams. (author)

  13. Comparative DFT study of crystalline ammonium perchlorate and ammonium dinitramide.

    Science.gov (United States)

    Zhu, Weihua; Wei, Tao; Zhu, Wei; Xiao, Heming

    2008-05-22

    The electronic structure, vibrational properties, absorption spectra, and thermodynamic properties of crystalline ammonium perchlorate (AP) and ammonium dinitramide (ADN) have been comparatively studied using density functional theory in the local density approximation. The results shows that the p states for the two solids play a very important role in their chemical reaction. From the low frequency to high frequency region, ADN has more motion modes for the vibrational frequencies than AP. The absorption spectra of AP and ADN display a few, strong bands in the fundamental absorption region. The thermodynamic properties show that ADN is easier to decompose than AP as the temperature increases. PMID:18396853

  14. Treatment of ammonium-rich swine waste in modified porphyritic andesite fixed-bed anaerobic bioreactor.

    Science.gov (United States)

    Wang, Qinghong; Yang, Yingnan; Li, Dawei; Feng, Chuanping; Zhang, Zhenya

    2012-05-01

    In this study, a modified porphyritic andesite (WRS) was developed as ammonium adsorbent and bed material for the anaerobic digestion of ammonium-rich swine waste. The performance in bioreactors with modified WRS, natural WRS, calcium chloride and no additives was investigated. The bioreactor with modified WRS exhibited the best performance, with start-up time on the 7th day, methane yield of 359.71 ml/g-VS, and COD removal of 67.99% during all 44 days of the experiment at 35°C. The effective ammonium adsorption and essential ions dissociation for microorganisms by modified WRS, as well as the immobilization of microbial on the surface of the modified WRS play a great role on the high efficiency anaerobic digestion of ammonium-rich swine waste. PMID:22366608

  15. Light-absorbing secondary organic material formed by glyoxal in aqueous aerosol mimics

    Science.gov (United States)

    Shapiro, E. L.; Szprengiel, J.; Sareen, N.; Jen, C. N.; Giordano, M. R.; McNeill, V. F.

    2009-01-01

    Light-absorbing and high-molecular-weight secondary organic products were observed to result from the reaction of glyoxal in mildly acidic (pH=4) aqueous inorganic salt solutions mimicking aqueous tropospheric aerosol particles. High-molecular-weight (500-600 amu) products were observed when ammonium sulfate ((NH4)2SO4) or sodium chloride (NaCl) was present in the aqueous phase. The products formed in the (NH4)2SO4 solutions absorb light at UV and visible wavelengths. Substantial absorption at 300-400 nm develops within two hours, and absorption between 400-600 nm develops within days. Pendant drop tensiometry measurements show that the products are not surface-active. The experimental results along with ab initio predictions of the UV/Vis absorption of potential products suggest that an aldol condensation mechanism is active in the glyoxal-(NH4)2SO4system, resulting in the formation of pi-conjugated products. If similar products are formed in atmospheric aerosol particles, they could change the optical properties of the seed aerosol over its lifetime.

  16. Light-absorbing secondary organic material formed by glyoxal in aqueous aerosol mimics

    Directory of Open Access Journals (Sweden)

    E. L. Shapiro

    2009-01-01

    Full Text Available Light-absorbing and high-molecular-weight secondary organic products were observed to result from the reaction of glyoxal in mildly acidic (pH=4 aqueous inorganic salt solutions mimicking aqueous tropospheric aerosol particles. High-molecular-weight (500–600 amu products were observed when ammonium sulfate ((NH42SO4 or sodium chloride (NaCl was present in the aqueous phase. The products formed in the (NH42SO4 solutions absorb light at UV and visible wavelengths. Substantial absorption at 300–400 nm develops within two hours, and absorption between 400–600 nm develops within days. Pendant drop tensiometry measurements show that the products are not surface-active. The experimental results along with ab initio predictions of the UV/Vis absorption of potential products suggest that an aldol condensation mechanism is active in the glyoxal-(NH42SO4system, resulting in the formation of pi-conjugated products. If similar products are formed in atmospheric aerosol particles, they could change the optical properties of the seed aerosol over its lifetime.

  17. Ober Phaseniibergange von Ammonium-Alkali-Jodiden und verwandten Halogeniden / Phase Transitions of Ammonium-alkali Iodides and Related Halides

    Science.gov (United States)

    Brauer, Peter

    1981-03-01

    The investigation of the order-disorder transitions of the ammonium-chlorides and -bromides, in which some of the NH4+ are replaced by Cs+, Rb+ or K+, is extended to the corresponding iodides using birefringence and differential thermal analysis. As the temperature range of the martensitic transition (Pm 3 m↔Fm 3 m) is now overlapping the temperature range of the orderdisorder transitions, the former must be included in the measurements. The results allowing an overlook are discussed using the work of Garland, Lushington, and Leung [5

  18. Extraction Factor Of Pure Ammonium Paratungstate From Tungsten Scraps

    Directory of Open Access Journals (Sweden)

    Pee J.-H.

    2015-06-01

    Full Text Available Typical oxidation process of tungsten scraps was modified by the rotary kiln with oxygen burner to increase the oxidation rate of tungsten scraps. Also to accelerate the solubility of solid oxidized products, the hydrothermal reflux method was adapted. By heating tungsten scraps in rotary kiln with oxygen burner at around 900° for 2hrs, the scraps was oxidized completely. Then oxidized products (WO3 and CoWO4 was fully dissolved in the solution of NaOH by hydrothermal reflux method at 150° for 2hrs. The dissolution rate of oxidized products was increased with increasing the reaction temperature and concentration of NaOH. And then CaWO4 and H2WO4 could be generated from the aqueous sodium tungstate solution. Ammonium paratungstate (APT also could be produced from tungstic acid using by aqueous ammonium solution. The morphologies (cubic and plate types of APT was controlled by the stirring process of purified solution of ammonium paratungstate.

  19. Preparation of chitosan quaternary ammonium salt in ionic liquid and its flocculating effect%离子液体中制备壳聚糖季铵盐及其絮凝效果研究

    Institute of Scientific and Technical Information of China (English)

    张聪璐; 胡筱敏; 祝雷; 王芳

    2013-01-01

    Ionic liquid of glycine hydrochloride has been synthesized through one-step synthesis.And chitosan quaternary ammonium salt has been made from quaternary ammonium reaction of 2,3-epoxypropyltrimethyl ammonium chloride and chitosan,with glycine hydrochloride aqueous solution as medium.Then it is applied to the treatment of traditional Chinese medicine wastewater.The effects of various reaction parameters,such as reaction temperature,reaction time,mass ratio of reactants and concentration of ionic liquid on the substitution degree of quatemary ammonium salt,as well as the effects of quaternary ammonium salt dosage,pH,stirring time on flocculating efficacy are investigated.The results show that both of the reaction efficacy of quaternary ammonium in ionic liquid and the degree of substitution of the product are higher than that of conventional non-homogeneous reaction.Chitosan quaternary ammonium salt could effectively remove the turbidity and COD from traditional Chinese medicine wastewater.%采用一步合成法制备了离子液体甘氨酸盐酸盐,以其水溶液为反应介质,壳聚糖与2,3-环氧丙基三甲基氯化铵进行季铵化反应,得到壳聚糖季铵盐,并将其用于中药废水的絮凝处理.考察了温度、时间、反应物配比及离子液体浓度对季铵盐取代度的影响,以及季铵盐加入量、pH、搅拌时间对絮凝效果的影响.实验结果表明,在离子液体中进行的季铵化反应效率及产品取代度均高于常规的非均相反应,壳聚糖季铵盐能够有效去除中药废水的浊度和COD.

  20. Oxidative desulfurization of diesel fuel using amphiphilic quaternary ammonium phosphomolybdate catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Jianghua; Wang, Guanghui; Zeng, Danlin; Tang, Yan [College of Chemical Engineering and Technology, Wuhan University of Science and Technology, Wuhan 430081 (China); Wang, Meng; Li, Yanjun [College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China)

    2009-12-15

    Phosphomolybdic acid (HPMo) modified respectively with tetramethyl ammonium chloride (TMAC), dodecyl trimethyl ammonium chloride (DTAC) and hexadecyl trimethyl ammonium chloride (HTAC) as the catalysts were prepared and characterized by FT-IR, XRD and SEM. The catalysts were evaluated for the oxidative desulfurization of benzothiophene (BT), dibenzothiophene (DBT) and straight-run diesel using hydrogen peroxide as an oxidant. Results show that all of the catalysts keep the Keggin structures and are finely dispersed with mixing of quaternary ammonium salts. Hexadecyl chains are more favorable to wrap up DBT to the catalytic center and form stable emulsion system with higher conversion rates of DBT. The shorter dodecyl chains can wrap up BT more suitably and bring smaller steric hindrance, which display higher conversion rates of BT. The oxidative reactions fit apparent first-order kinetics, and the apparent activation energies of DBT are much lower than those of BT. The desulfurization rate of straight-run diesel can be up to 84.4% with the recovery rate of 98.1% catalyzed by [HPMo][HTAC]{sub 2} in 2 h. When increasing the extraction times, the desulfurization rates increase, but the recovery rates of diesel decrease significantly. (author)

  1. Anion exchange removal of Al3+ from Li+-Al3+ aqueous solution (originating from lithium recovery from brine

    Directory of Open Access Journals (Sweden)

    Anissa Somrani

    2014-06-01

    Full Text Available The purpose of this study is to separate aluminum(III ion from an aqueous solution containing Li+ at 25°C. Al3+ was transferred into [Al(C2O43]3- by means of complexation and removed by an anion exchange resin. This resin was anionic type Amberlite IRA 402 regenerated by sodium chloride. Hence, a theoretical study based on speciation diagrams was carried out to determine the best pH domain for separation. The complexation of aluminum ions by ammonium oxalate was studied. The motar ratio of Ox/Al and pH was investigated. Optimum values of these factors were found to be 3 and 4 respectively. In this case, the remaining lithium is 98.5%.

  2. Hafnium extraction from acidic chloride solutions by Cyanex 923

    Energy Technology Data Exchange (ETDEWEB)

    El-Ammouri, E.; Distin, P.A. [McGill Univ., Montreal (Canada)

    1996-08-01

    Hafnium extraction from hydrochloric acid/lithium chloride solutions into Cyanex 923 in kerosene has been studied. Variables investigated were hydrochloric acid, total chloride and hafnium concentrations in the aqueous phase, and extractant/modifier (isodecanol) levels in the organic phase. Hafnium is considered to load as the tetrachloride complex forming a disolvate with Cyanex 923. Results are compared with equivalent data for zirconium extraction. 14 refs., 7 figs., 2 tabs.

  3. Winter Wheat and Maize Response to Urea Ammonium Nitrate and a New Urea Formaldehyde Polymer Fertilizer

    Science.gov (United States)

    Slow release nitrogen (N) fertilizers have potential to improve yield and nitrogen use efficiency (NUE) in winter wheat (Triticum aestivum L.) and maize (Zea mays L.). A slow release urea formaldehyde polymer (UFP) was compared with conventional aqueous urea-ammonium nitrate (UAN) [(NH2)2CO, NH4NO3]...

  4. Catalyst used in 1,2-epoxyalkane preparation is obtained by heating tetraalkyl ammonium salts, tetraalkyl siloxanes and amines, calcining and treating with a tetraalkoxy compound

    DEFF Research Database (Denmark)

    2001-01-01

    NOVELTY - The catalyst, used in 1,2-epoxyalkane preparation, is obtained by heat treating an aqueous composition comprising tetraalkyl ammonium salts, tetraalkyl siloxanes and amines, removing the template by calcining and treating with a tetraalkoxy compound......NOVELTY - The catalyst, used in 1,2-epoxyalkane preparation, is obtained by heat treating an aqueous composition comprising tetraalkyl ammonium salts, tetraalkyl siloxanes and amines, removing the template by calcining and treating with a tetraalkoxy compound...

  5. CdTe/ZnS quantum dots as fluorescent probes for ammonium determination.

    Science.gov (United States)

    Yi, Kui-Yu

    2016-06-01

    Novel CdTe/ZnS quantum dot (QD) probes based on the quenching effect were proposed for the simple, rapid, and specific determination of ammonium in aqueous solutions. The QDs were modified using 3-mercaptopropionic acid, and the fluorescence responses of the CdTe/ZnS QD probes to ammonium were detected through regularity quenching. The quenching levels of the CdTe/ZnS QDs and ammonium concentration showed a good linear relationship between 4.0 × 10(-6) and 5.0 × 10(-4) mol/L; the detection limit was 3.0 × 10(-7) mol/L. Ammonium contents in synthetic explosion soil samples were measured to determine the practical applications of the QD probes and a probable quenching mechanism was described. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26542194

  6. Chloride ingress prediction

    DEFF Research Database (Denmark)

    Frederiksen, Jens Mejer; Geiker, Mette Rica

    2008-01-01

    Prediction of chloride ingress into concrete is an important part of durability design of reinforced concrete structures exposed to chloride containing environment. This paper presents experimentally based design parameters for Portland cement concretes with and without silica fume and fly ash in...

  7. 21 CFR 582.1141 - Ammonium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ammonium phosphate. 582.1141 Section 582.1141 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1141 Ammonium phosphate. (a) Product. Ammonium phosphate (mono- and dibasic). (b)...

  8. Removal of blue 1 dye of aqueous solutions with a modified clay with iron chloride; Remocion de colorante azul 1 de soluciones acuosas con una arcilla modificada con cloruro de hierro

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez H, K. A.

    2012-07-01

    At the present time, several technologies have been proposed to remove dyes from water, adsorption is one of the most feasible methods and adsorbents with different properties, such as activated carbon, zeolites, clays and hydrogels among others. In this work, the sorption behavior of blue 1 dye by a natural clay from a site located in the Center-East of Mexico, and other modified with iron chloride were determined. The materials were characterized by X-ray diffraction to analyze its crystal structure, by scanning electron microscopy and elemental microanalysis of energy dispersive X-ray spectrometry to determine the composition and morphology, and the zero point charges were also determined to know the charge distribution on the surface of the clay. The ph effect, contact time, dye concentration and temperature were the parameters considered in this study. The results showed that clay does not suffer any important changes in its structure after the chemical treatments (modification with ferric chloride and contact with blue 1 solutions). The ph influences lightly the adsorption of the dye with natural clay, but the same effect is not observed in the ferric modified clay among the factor ph 6 and 8. The equilibrium time and the sorption capacity for natural clay were 48 hours and 6.16 mg/g, while for the ferric clay were 24 hours and 14.22 mg/g. Adsorption kinetics results were best adjusted to the pseudo first and pseudo second order models. Adsorption isotherms were best adjusted to the Langmuir model, indicating that both clays have a homogeneous surface. Thermodynamic parameters (E, {Delta}S and {Delta}G and {Delta}H) were calculated for the dye adsorption by the natural clay using data of the adsorption kinetics at temperatures between 20 and 50 C, indicating that the adsorption process is exothermic. For the case of ferric clay, it was not possible to calculate these thermodynamic parameters because the adsorption capacities were similar in the range of

  9. 77 FR 50613 - Didecyl Dimethyl Ammonium Carbonate and Didecyl Dimethyl Ammonium Bicarbonate; Exemption From the...

    Science.gov (United States)

    2012-08-22

    ... AGENCY 40 CFR Part 180 Didecyl Dimethyl Ammonium Carbonate and Didecyl Dimethyl Ammonium Bicarbonate... Didecyl Dimethyl Ammonium Carbonate and Didecyl Dimethyl Ammonium Bicarbonate, jointly referred to as.... Background and Statutory Findings In the Federal Register of December 8, 2011 (76 FR 76674) (FRL-...

  10. Phase diagram of ammonium nitrate

    Science.gov (United States)

    Dunuwille, M.; Yoo, C. S.

    2014-05-01

    Ammonium Nitrate (AN) has often subjected to uses in improvised explosive devices, due to its wide availability as a fertilizer and its capability of becoming explosive with slight additions of organic and inorganic compounds. Yet, the origin of enhanced energetic properties of impure AN (or AN mixtures) is neither chemically unique nor well understood -resulting in rather catastrophic disasters in the past1 and thereby a significant burden on safety in using ammonium nitrates even today. To remedy this situation, we have carried out an extensive study to investigate the phase stability of AN at high pressure and temperature, using diamond anvil cells and micro-Raman spectroscopy. The present results confirm the recently proposed phase IV-to-IV' transition above 17 GPa2 and provide new constraints for the melting and phase diagram of AN to 40 GPa and 400 °C.

  11. Phase diagram of ammonium nitrate

    International Nuclear Information System (INIS)

    Ammonium Nitrate (AN) has often subjected to uses in improvised explosive devices, due to its wide availability as a fertilizer and its capability of becoming explosive with slight additions of organic and inorganic compounds. Yet, the origin of enhanced energetic properties of impure AN (or AN mixtures) is neither chemically unique nor well understood -resulting in rather catastrophic disasters in the past1 and thereby a significant burden on safety in using ammonium nitrates even today. To remedy this situation, we have carried out an extensive study to investigate the phase stability of AN at high pressure and temperature, using diamond anvil cells and micro-Raman spectroscopy. The present results confirm the recently proposed phase IV-to-IV' transition above 17 GPa2 and provide new constraints for the melting and phase diagram of AN to 40 GPa and 400 °C.

  12. Proton- and ammonium- sensing by histaminergic neurons controlling wakefulness.

    Directory of Open Access Journals (Sweden)

    Yvgenij eYanovsky

    2012-04-01

    Full Text Available Orexinergic and histaminergic neurons in the posterior hypothalamus are involved in the control of arousal. Extracellular levels of acid /CO2 are fundamental physicochemical signals controlling wakefulness and breathing. Acidification excites orexinergic neurons like the chemosensory neurons in the brain stem. Hypercapnia induces c-Fos expression, a marker for increased neuronal activity, in the rat histaminergic tuberomamillary nucleus (TMN, but the mechanisms of this excitation are unknown. Acid-sensing ion channels (ASICs are gated by protons and also by ammonium. Recordings in rat brain slices revealed now that acidification within the physiological range (pH from 7.3 to 7.0 as well as ammonium chloride (5mM excite histaminergic neurons. We detected variable combinations of 4 known types of ASICs in single TMN neurons, along with the pharmacological properties of pH-induced current. At pH 7.0 however, activation of ASICs in TMN neurons was negligible. Block of type I metabotropic glutamate receptors abolished proton- but not ammonium- induced excitation. Mouse TMN neurons were identified within a novel HDC-Cre transgenic reporter mouse line. In contrast to the rat these lacked pH 7.0-induced excitation and showed only a minimal response to the mGluR I agonist DHPG (0.5µM. Ammonium-induced excitation was similar in mouse and rat. Thus glutamate, which is released by glial cells and orexinergic axons amplifies CO2/acid-induced arousal through the recruitment of the histaminergic system in rat but not in mouse. These results are relevant for the understanding of neuronal mechanisms controlling H+/CO2-induced arousal in hepatic encephalopathy and obstructive sleep apnoea. The new HDC-Cre mouse model will be a useful tool for studying the physiological and pathophysiological roles of the histaminergic system.

  13. Application of Neesler reagent in the ammonium quantification used in the fermentations of biotechnology products

    Directory of Open Access Journals (Sweden)

    Dinorah Torres-Idavoy

    2015-08-01

    Full Text Available The ammonium salts are used in fermentations to supplement the deficient amounts of nitrogen and stabilize the pH of the culture medium. The excess ammonium ion exerts a detrimental effect on the fermentation process inhibiting microbial growth. An analytical method based on Neesler reagent was developed for monitoring and controlling the concentration of ammonium during the fermentation process. The test was standardized, by means of the selection of measuring equipment, and the reaction time as well as comparing standards of ammonium salts. The method was characterized with the evaluation of the next parameters: Specificity, Linearity and Range, Quantification Limit, Accuracy and Precision. The method proved to be specific. Two linear curves were defined in the ranges of concentrations of ammonium chloride salt (2-20 μg/ml and ammonium sulfate salt (5-30 μg/ml. The limits of quantification were the lowest points of each one. The method proved to be accurate and precise. This assay was applied to samples of the yeast culture and bacteria of the genus Saccharomyces and E. coli respectively. A novel method in micro plate for quantification and analytical control of ammonia was developed. This method is used to control this fundamental chemical component in the fermentations, to optimize the culture medium. Thus, an appropriate expression of recombinant proteins and proper vaccine candidates for clinical use are achieved

  14. Synthesis and Characterization of Ammonium-, Pyridinium-, and Pyrrolidinium-Based Sulfonamido Functionalized Ionic Liquids

    DEFF Research Database (Denmark)

    Shunmugavel, Saravanamurugan; Fehrmann, Rasmus; Riisager, Anders

    2012-01-01

    New homologous ammonium-, pyridinium-, and pyrrolidinium-based sulfonamido functionalized ionic liquids have been synthesized in two steps using monoethanolamine, methanesulfonyl chloride, and tosyl chloride as precursors with ethanol as solvent. Attempts to synthesize dual amino functionalized...... ionic liquid containing both a primary and a secondary amine group in the same ionic liquid are also reported. All functionalized ionic liquids were characterized by 1H and 13C NMR. Melting point and thermal stability of the functionalized ionic liquids were measured by differential scanning calorimetry...

  15. Chloride ingress prediction

    DEFF Research Database (Denmark)

    Frederiksen, Jens Mejer; Geiker, Mette Rica

    2008-01-01

    makes physical sense for the design engineer, i.e. the achieved chloride diffusion coefficients at 1 year and 100 years, D1 and D100 respectively, and the corresponding achieved chloride concentrations at the exposed concrete surface, C1 and C100. Data from field exposure supports the assumption of time...... dependent surface chloride concentrations and the diffusion coefficients. Model parameters for Portland cement concretes with and without silica fume and fly ash in marine atmospheric and submerged South Scandinavian environment are suggested in a companion paper based on 10 years field exposure data....

  16. Natural attenuation potential of tricholoroethene in wetland plant roots: role of native ammonium-oxidizing microorganisms.

    Science.gov (United States)

    Qin, Ke; Struckhoff, Garrett C; Agrawal, Abinash; Shelley, Michael L; Dong, Hailiang

    2015-01-01

    Bench-scale microcosms with wetland plant roots were investigated to characterize the microbial contributions to contaminant degradation of trichloroethene (TCE) with ammonium. The batch system microcosms consisted of a known mass of wetland plant roots in aerobic growth media where the roots provided both an inoculum of root-associated ammonium-oxidizing microorganisms and a microbial habitat. Aqueous growth media, ammonium, and TCE were replaced weekly in batch microcosms while retaining roots and root-associated biomass. Molecular biology results indicated that ammonium-oxidizing bacteria (AOB) were enriched from wetland plant roots while analysis of contaminant and oxygen concentrations showed that those microorganisms can degrade TCE by aerobic cometabolism. Cometabolism of TCE, at 29 and 46 μg L(-1), was sustainable over the course of 9 weeks, with 20-30 mg L(-1) ammonium-N. However, at 69 μg L(-1) of TCE, ammonium oxidation and TCE cometabolism were completely deactivated in two weeks. This indicated that between 46 and 69 μg L(-1) TCE with 30 mg L(-1) ammonium-N there is a threshold [TCE] below which sustainable cometabolism can be maintained with ammonium as the primary substrate. However, cometabolism-induced microbial deactivation of ammonium oxidation and TCE degradation at 69 μg L(-1) TCE did not result in a lower abundance of the amoA gene in the microcosms, suggesting that the capacity to recover from TCE inhibition was still intact, given time and removal of stress. Our study indicates that microorganisms associated with wetland plant roots can assist in the natural attenuation of TCE in contaminated aquatic environments, such as urban or treatment wetlands, and wetlands impacted by industrial solvents.

  17. Determination of the constants of the solubility product of Ln(OH)3 and the effect of the chloride ions on the lanthanum hydrolysis, praseodymium and lutetium in aqueous solutions of ion force 2 Molar

    International Nuclear Information System (INIS)

    The behavior of lanthanum (III), praseodymium (III), and lutetium (III) was studied in 2 M NaClO4 (aq) and 2 M NaCl (aq) at 303 K and free -CO2 conditions. Solubility diagrams (p Ln(aq)-pCH) were obtained by means of a radiochemical method. The pCH borderlines of saturation and unsaturation zones of the solutions and solubility product constants for Ln(OH)3 were determined from these diagrams. The fitting of the solubility equation to the experimental values of p Ln(aq)-pCH diagrams allowed the calculation of the first hydrolysis and solubility product constants. Independently, the stability constants for the first species of hydrolysis were determined by means of pH titrations, the data were treated with the program SUPERQUAD and fitted to the mean ligand number equation. The stability constants for the species LnCl2+ were as well calculated in 2M ionic strength and 303 K from the hydrolysis constant values obtained in both perchlorate and chloride media. The values obtained for La, Pr and Lu were: logKps: 21.11 ± 0.09, 19.81 ± 0.11 and 18.10 ± 0.13 in 2M NaClO4; logKps: 22.22 ± 0.09, 21.45 ± 0.14 and 18.52 ± 0.29 in 2M NaCl; log β1: - 8.64 ± 0.02, - 8.37 ± 0.01 and - 7.95 ± 0.11 in 2M NaClO4; log β1/ : - 9.02 ± 0.11, - 8.75 ± 0.01 and - 8.12 ± 0.03 in 2M NaCl and the values for log β1,Cl were - 0.0255, - 0.155 and - 0.758, respectively. (Author)

  18. Reaction of uranium dioxide with copper-containing chloride melts

    International Nuclear Information System (INIS)

    Cermet composition materials consisting of metallic copper and uranium dioxide can be used for manufacturing fuel rods of nuclear power reactors. Reprocessing of such irradiated fuel of dispersive type can be done employing non-aqueous pyrochemical methods and developing such technology requires information on interaction of uranium dioxide with chloride melts containing copper ions

  19. A chronopotentiometric approach for measuring chloride ion concentration

    NARCIS (Netherlands)

    Abbas, Yawar; Olthuis, Wouter; Berg, van den Albert

    2013-01-01

    In this paper, a novel approach is reported for the electrochemical measurement of chloride ions in aqueous solution. This sensor is based on the stimulus/response principle of chronopotentiometry. A current pulse is applied at the Ag/AgCl working electrode and the potential change is measured with

  20. Effect of 60Co gamma-ray irradiation on dilute aqueous solutions of surfactants

    International Nuclear Information System (INIS)

    Present work deals with the effects of gamma irradiation from 60Co γ-ray source upon aqueous solutions of three kinds of surfactants. When dilute aqueous solutions of sodium dodecyl sulfate (SDS, anionic), cethyl trimethyl ammonium chloride (CTAC, cationic), and polyoxyethylene lauryl ether (POE, non-ionic) were irradiated with γ-rays at a room temperature, the residual concentration, products, surface tension, and forming power were examined by colorimetric method, IR spectrophotometric method, gaschromatography, Ross-Miles method, and Traube's stalagmometer etc. These surfactants were decomposed by the irradiation and thus the surface tension increased and the forming power, on the contrary, decreased with dose. Radiation chemical yields (G-value) of the degradation were about 1 for the solutions of SDS and CTAC, and about 0.3 for the POE solution. From the experimental results, it was found that following chemical reactions seem to occur followed by the radiolysis of water: a) bond cleavage of ester for SDS, of CN for CTAC, and of oxyethylene for POE, b) hydrogen abstraction from the surfactants, c) production of CO bond in the presence of dissolved oxygen. (auth.)

  1. Quaternary Ammonium Polyethyleneimine: Antibacterial Activity

    Directory of Open Access Journals (Sweden)

    Ira Yudovin-Farber

    2010-01-01

    Full Text Available Quaternary ammonium polyethyleneimine- (QA-PEI- based nanoparticles were synthesized using two synthetic methods, reductive amination and N-alkylation. According to the first method, QA-PEI nanoparticles were synthesized by cross-linking with glutaraldehyde followed by reductive amination with octanal and further N-methylation with methyl iodide. The second method is based on crosslinking with dialkyl halide followed by N-alkylation with octyl halide and further N-methylation with methyl iodide. QA-PEI nanoparticles completely inhibited bacterial growth (>106 bacteria, including both Gram-positive, that is, Staphylococcus aureus at 80 g/mL, and Gram-negative, that is, Escherichia coli at 320 g/mL. Activity analysis revealed that the degree of alkylation and N-methylation of the QA-PEI nanoparticles plays a significant role in antibacterial activity of the reagent. The most potent compound was octyl alkylated QA-PEI alkylated at 1 : 1 mole ratio (primary amine of PEI monomer units/alkylating agent. Also, cytotoxicity studies on MAT-LyLu and MBT cell lines were performed with QA-PEI nanoparticles. These findings confirm previous reports that polycations bearing quaternary ammonium moieties inhibit bacterial growth in vitro and have a potential use as additives in medical devices which need antibacterial properties.

  2. Synthesis of Chitosan Quaternary Ammonium Salts

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A series of N-alkyl or N-aryl chitosan quaternary ammonium salts were prepared via Schiffs base intermediates. Quaternization of N-substituted chitosan derivatives was carried out using methyl iodide to produce water-soluble cationic chitosan quaternary ammonium salt. The products were characterized by IR, 1HNMR and elemental analysis. The degree of substitution of chitosan quaternary ammonium salt was calculated by elemental analysis.

  3. A comparison of dissolved inorganic nitrogen, chloride and potassium loss in conventional and conservation tillage

    Science.gov (United States)

    Tillage impact on dissolved losses of ammonium (NH4-N) and nitrate nitrogen (NO3-N), chloride (Cl), and potassium (K) during rotational cotton and peanut production was evaluated. Tillage treatments were strip-tillage (ST) and conventional-tillage (CT). Winter cover crops were used in both tillage...

  4. 33 CFR 126.28 - Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate...

    Science.gov (United States)

    2010-07-01

    ... nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate; general provisions. 126.28 Section 126..., ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate; general provisions. (a) When any item of ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo...

  5. Ammonium-induced inhibition of ammonium-starved Nitrosomonas europaea cells in soil and sand slurries

    NARCIS (Netherlands)

    Gerards, S.; Duyts, H.; Laanbroek, H.J.

    1998-01-01

    Ammonia-oxidising bacteria are poor competitors for limiting amounts of ammonium. Hence, starvation for ammonium seems to be the regular condition for these bacteria in natural environments. Long-term survival in the absence of ammonium will be dependent on the ability to maintain large population s

  6. Determination of tracer diffusion coefficients of 22NaCl as function of magnesium chloride concentration in water at 25°C

    Science.gov (United States)

    Ahl, J.; Liukkonen, S.

    1999-01-01

    The tracer diffusion coefficients of sodium-22-chloride were determined as function of magnesium chloride concentrations in aqueous solutions (10-4...1 mol dm-3) at 25°C. Closed capillary method was used in experiments. The most accurate method to calculate the tracer diffusion coefficient from an infinite series solution was further developed. The Onsager limiting law was verified to the tracer diffusion of 22NaCl in aqueous magnesium chloride in low concentration region.

  7. Synthesis and Spectroscopic Characterisation of 2,3-Epoxy/3-Chloro-2-hydroxy Propyl Derivatives of Quaternary Ammonium Salts: Useful Cationic Fixing Agents

    Institute of Scientific and Technical Information of China (English)

    SHARIF Saima; AHMAD Saeed; IZHAR-UL-HAQ Mian Muhammad

    2008-01-01

    Eight mono-reactive and four bis-reactive 2,3-epoxy/3-chloro-2-hydroxy propyl derivatives of quaternary ammonium salts have been synthesised by reacting epichlorohydrin with suitable tertiary amines and diamines.Mono-reactive derivatives also contain cyano and carboxylic groups in addition to 2,3-epoxy/3-chloro-2-hydroxy propyl groups. The structures of these quaternary ammonium salts have been characterised using IR and 1H NMR spectroscopic techniques. These quaternary ammonium chlorides have been applied to the cotton fabrics as pretreatments and aftertreatments and promising results have been obtained.

  8. Transport and fate of ammonium and its impact on uranium and other trace elements at a former uranium mill tailing site

    International Nuclear Information System (INIS)

    Highlights: • Nitrification of ammonium evidenced by stable isotopes of nitrate at a mining site. • Concentrations of uranium and other trace elements related to ammonium conc. • Observed impact of ammonium on redox, pH, and possibly complexation. • Proposed impact of transformation of NO3 and NH4 on trace elements. - Abstract: The remediation of ammonium-containing groundwater discharged from uranium mill tailing sites is a difficult problem facing the mining industry. The Monument Valley site is a former uranium mining site in the southwest US with both ammonium and nitrate contamination of groundwater. In this study, samples collected from 14 selected wells were analyzed for major cations and anions, trace elements, and isotopic composition of ammonium and nitrate. In addition, geochemical data from the U.S. Department of Energy (DOE) database were analyzed. Results showing oxic redox conditions and correspondence of isotopic compositions of ammonium and nitrate confirmed the natural attenuation of ammonium via nitrification. Moreover, it was observed that ammonium concentration within the plume area is closely related to concentrations of uranium and a series of other trace elements including chromium, selenium, vanadium, iron, and manganese. It is hypothesized that ammonium–nitrate transformation processes influence the disposition of the trace elements through mediation of redox potential, pH, and possibly aqueous complexation and solid-phase sorption. Despite the generally relatively low concentrations of trace elements present in groundwater, their transport and fate may be influenced by remediation of ammonium or nitrate at the site

  9. Atmospheric behaviour of ammonia and ammonium.

    NARCIS (Netherlands)

    Asman, W.A.J.

    1987-01-01

    1.4.1 Scope of this thesisA few models for ammonia and ammonium exist. Russell et al. (1983) made a multi-layer Lagrangian transport model describing the transport and formation of ammonium nitrate aerosol for California. They did not take reactions of ammonia and sulphuric acid into account, nor we

  10. Chloride removal from vitrification offgas

    International Nuclear Information System (INIS)

    This study identified and investigated techniques of selectively purging chlorides from the low-level waste (LLW) vitrification process with the purge stream acceptable for burial on the Hanford Site. Chlorides will be present in high concentration in several individual feeds to the LLW Vitrification Plant. The chlorides are highly volatile in combustion type melters and are readily absorbed by wet scrubbing of the melter offgas. The Tank Waste Remediation System (TWRS) process flow sheets show that the resulting chloride rich scrub solution is recycled back to the melter. The chlorides must be purged from the recycle loop to prevent the buildup of excessively high chloride concentrations

  11. 49 CFR 176.415 - Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers.

    Science.gov (United States)

    2010-10-01

    ... nitrates, and certain ammonium nitrate fertilizers. 176.415 Section 176.415 Transportation Other... requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers. (a) Except as... Captain of the Port (COTP). (1) Ammonium nitrate UN1942, ammonium nitrate fertilizers containing more...

  12. Influence of TAC on Dispersion of Aqueous Nano Alumina Suspension

    Institute of Scientific and Technical Information of China (English)

    ZHAO Wei; YANG De-an; SONG Jian-jing; YANG Zi; LIANG Chong; XU Ming-xia; XU Ting-xian

    2004-01-01

    The stability of aqueous nano alumina powder suspensions with and without dispersant tri-ammonium citrate (TAC) was investigated by measuring zeta potential at different pH values. The isoelectric point (IEP) of alumina powder shifts towards more acidic pH range by adding TAC dispersant. The results illustrate that adsorption of TAC on alumina powder surface existed in the aqueous suspension, which leads to a high stability of the suspension.

  13. A non-destructive ammonium detection method as indicator for freshness for packed fish: Application on cod

    NARCIS (Netherlands)

    Heising, J.K.; Dekker, M.; Bartels, P.V.; Boekel, van M.A.J.S.

    2012-01-01

    This paper introduces a non-destructive method for monitoring headspace ammonium as an indicator for changes in the freshness status of packed fish. Electrodes in an aqueous phase in the package monitor changes in the concentration of ammonia produced in/on the packed fish and released in the headsp

  14. Coefficients of caffeine distribution in aliphatic alcohol-ammonium sulfate-water systems

    Science.gov (United States)

    Korenman, Ya. I.; Krivosheeva, O. A.; Mokshina, N. Ya.

    2012-11-01

    The extraction of caffeine with aliphatic alcohols C3-C9 from aqueous solutions in the presence of a salting-out agent (ammonium sulfate) is studied. Quantitative characteristics of extraction are calculated: the distribution coefficients ( D) and the degree of recovery ( R, %). Relations are found between log D of caffeine and the length of the hydrocarbon radical in the alcohol molecule, along with certain physicochemical properties of the extragents.

  15. Pharmaceutical modulation of diffusion potentials at aqueous-aqueous boundaries under laminar flow conditions.

    Science.gov (United States)

    Collins, Courtney J; Strutwolf, Jörg; Arrigan, Damien W M

    2011-04-01

    In this work, the modulation of the diffusion potential formed at the microfluidic aqueous-aqueous boundary by a pharmaceutical substance is presented. Co-flowing aqueous streams in a microchannel were used to form the stable boundary between the streams. Measurement of the open circuit potential between two silver/silver chloride electrodes enabled the diffusion potential at the boundary to be determined, which is concentration dependent. Experimental results for protonated propranolol as well as tetrapropylammonium are presented. This concept may be useful as a strategy for the detection of drug substances.

  16. Ammonium and attachment of Rhodopirellula baltica.

    Science.gov (United States)

    Frank, Carsten S; Langhammer, Philipp; Fuchs, Bernhard Maximilian; Harder, Jens

    2011-05-01

    A dimorphic life cycle has been described for the planctomycete Rhodopirellula baltica SH1(T), with juvenile motile, free-swimming cells and adult sessile, attached-living cells. However, attachment as a response to environmental factors was not investigated. We studied the response of R. baltica to nitrogen limitation. In batch cultures, ammonium limitation coincided with a dominance of free-swimming cells and a low number of aggregates. Flow cytometry revealed a quantitative shift with increasing ammonium availability, from single cells towards attached cells in large aggregates. During growth of R. baltica on glucose and ammonium in chemostats, an ammonium addition caused a macroscopic change of the growth behaviour, from homogeneous growth in the liquid phase to a biofilm on the borosilicate glass wall of the chemostat vessel. Thus, an ammonium limitation-a carbon to nitrogen supply ratio of 30:1-sustained free-living growth without aggregate formation. A sudden increase in ammonium supply induced sessile growth of R. baltica. These observations reveal a response of Rhodopirellula baltica cells to ammonium: they abandon the free-swimming life, attach to particles and form biofilms. PMID:21340506

  17. Review of Options for Ammonia/Ammonium Management

    Energy Technology Data Exchange (ETDEWEB)

    Nash, C. A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-05-06

    This report is a review of literature supporting practical ammonia/ammonium destruction processes. Melter research supporting Hanford Low Activity Waste (LAW) glass production has shown that significant amounts of ammonia will be in the melter offgas condensate. Further work with secondary waste forms indicates the potential need to remove the ammonia, perhaps by an oxidative process. This review finds likely practical chemical methods to oxidize ammonia in aqueous solution at moderate temperatures and atmospheric pressure, using easily obtained reagents. Leading candidates include nitrite oxidation to produce nitrogen gas, various peroxide oxidative processes, and air stripping. This work reviews many other processes and provides reasoning to not consider those processes further for this application.

  18. Determination of ammonium on an integrated microchip with LED-induced fluorescence detection

    Institute of Scientific and Technical Information of China (English)

    Shuhua Xue; Katsumi Uchiyama; Hai-fang Li

    2012-01-01

    A simply fabricated microfluidic device integrated with a fluorescence detection system has been developed for on-line determination of ammonium in aqueous samples.A 365-nm light-emitting diode(LED)as an excitation source and a minor band pass filter were mounted into a polydimethylsiloxane(PDMS)-based microchip for the purpose of miniaturization of the entire analytical system.The ammonium sample reacted with o-phthaldialdehyde(OPA)on-chip with sodium sulfite as reducing reagent to produce a fluorescent isoindole derivative,which can emit fluorescence signal at about 425 nm when excited at 365 nm.Effects of pH,flow rate of solutions,concentrations of OPA-reagent,phosphate and sulfite salt were investigated.The calibration curve of ammonium in the range of 0.018-1.8 μg/mL showed a good linear relationship with R2 =0.9985,and the detection limit was(S/N =3)3.6 × 10-4 μg/mL.The relative standard deviation was 2.8%(n =11)by calculating at 0.18 μg/mL ammonium for repeated detection.The system was applied to determine the ammonium concentration in rain and river waters,even extent to other analytes fluorescence detection by the presented device.

  19. Evaluation of natural zeolite clinoptilolite efficiency for the removal of ammonium and nitrate from aquatic solutions

    Directory of Open Access Journals (Sweden)

    Mozhdeh Murkani

    2015-01-01

    Full Text Available Background: Surface water and groundwater pollution with various forms of nitrogen such as ammonium and nitrate ions is one of the main environmental risks. The major objectives of this study were to evaluate the capacity of natural zeolite (clinoptilolite to remove NO3– and NH4+ from polluted water under both batch and column conditions. Methods: The laboratory batch and column experiments were conducted to investigate the feasibility of clinoptilolite as the adsorbent for removal of nitrate (NO3– and ammonium (NH4+ ions from aqueous solution. The effects of pH, clinoptilolite dosage, contact time, and initial metal ion concentration on NO3– and NH4+ removal were investigated in a batch system. Results: Equilibrium time for NO3– and NH4+ ions exchange was 60 minutes and the optimum adsorbent dosage for their removal was 1 and 2.5 g/L, respectively. The adsorption isotherm of reaction (r> 0.9 and optimum entered concentration of ammonium and nitrate (30 and 6.5 mg/L, respectively were in accordance with Freundlich isotherm model. The ammonium removal rate increased by 98% after increasing the contact time. Conclusion: Our findings confirmed that natural Clinoptilolite can be used as one of effective, suitable, and low-costing adsorbent for removing ammonium from polluted waters.

  20. Chemical behaviour of plutonium in aqueous chloride solutions

    International Nuclear Information System (INIS)

    The chemical behaviour of Plutonium has been investigated in concentrated NaCl solutions in the neutral pH range. The α-radiation induced radiolysis reactions oxidize the Cl--ion to Cl2, HClO, ClO- and other species, which produce a strongly oxidizing medium. Under these conditions the Pu ions of lower oxidation states are readily oxidized to Pu(VI), which then undergo depending on the pH of the solution, various chemical reactions to produce PuO2Cln, PuO2(ClO)m or PuO2(OH)x species. In addition to primary radiolysis reactions taking place in NaCl solutions, the reactions leading to the PuO2(Cl)n and PuO2(ClO)m species have been characterized and quantified systematically by spectroscopic and thermodynamic evaluation. The redox and complexation reactions of Pu ions under varying NaCl concentration, specific α-activity and pH are discussed. (orig.)

  1. [Degradation of succinylcholine chloride].

    Science.gov (United States)

    Németh, G; Török, I; Paál, T

    1993-05-01

    Quantitative thin-layer chormatographic method has been developed for the investigation of the degradation of injection formulations containing succinylcholinium chloride. The method is based on the denistometric determination of the main degradation product, choline at 430 nm after visualization with iodine vapour. The stability of the injection was investigated under various storage conditions and it has been stated that considerable decomposition takes place during as short a period as one week. PMID:8362654

  2. Effects of the physical state of tropospheric ammonium-sulfate-nitrate particles on global aerosol direct radiative forcing

    Directory of Open Access Journals (Sweden)

    S. T. Martin

    2004-01-01

    Full Text Available The effect of aqueous versus crystalline sulfate-nitrate-ammonium tropospheric particles on global aerosol direct radiative forcing is assessed. A global three-dimensional chemical transport model predicts sulfate, nitrate, and ammonium aerosol mass. An aerosol thermodynamics model is called twice, once for the upper side (US and once for lower side (LS of the hysteresis loop of particle phase. On the LS, the sulfate mass budget is 40% solid ammonium sulfate, 12% letovicite, 11% ammonium bisulfate, and 37% aqueous. The LS nitrate mass budget is 26% solid ammonium nitrate, 7% aqueous, and 67% gas-phase nitric acid release due to increased volatility upon crystallization. The LS ammonium budget is 45% solid ammonium sulfate, 10% letovicite, 6% ammonium bisulfate, 4% ammonium nitrate, 7% ammonia release due to increased volatility, and 28% aqueous. LS aerosol water mass partitions as 22% effloresced to the gas-phase and 78% remaining as aerosol mass. The predicted US/LS global fields of aerosol mass are employed in a Mie scattering model to generate global US/LS aerosol optical properties, including scattering efficiency, single scattering albedo, and asymmetry parameter. Global annual average LS optical depth and mass scattering efficiency are, respectively, 0.023 and 10.7 m2 (g SO4-2-1, which compare to US values of 0.030 and 13.9 m2 (g SO4-2-1. Radiative transport is computed, first for a base case having no aerosol and then for the two global fields corresponding to the US and LS of the hysteresis loop. Regional, global, seasonal, and annual averages of top-of-the-atmosphere aerosol radiative forcing on the LS and US (FL and FU, respectively, in W m-2 are calculated. Including both anthropogenic and natural emissions, we obtain global annual averages of FL=-0.750, FU=-0.930, and DFU,L=24% for full sky calculations without clouds and FL=-0.485, FU=-0.605, and DFU,L=25% when clouds are included. Regionally, DFU,L=48% over the USA, 55% over Europe

  3. Degradation and bound-residue formation of nonylphenol in red soil and the effects of ammonium

    International Nuclear Information System (INIS)

    Fate of nonylphenol (NP) in soils and the effects of nitrogen fertilizers are unclear. Using 14C-tracer, we studied the aerobic and anaerobic degradation of 4-NP111 in a paddy red soil amended without and with ammonium chloride. Under oxic conditions, 4-NP111 had a half-life of 16.1 ± 1.6 days and minor mineralization (3.84 ± 0.02%), forming no extractable metabolite but abundant bound residues (60.9 ± 1.7%, mostly bound to humin) after 49 days of incubation. The ammonium amendment (8 mmol/kg soil) significantly inhibited the degradation (half-life of 68.0 ± 7.7 days), mineralization (2.0 ± 1.1%), and bound-residue formation (23.7 ± 0.2%). Under anoxic conditions, 4-NP111 did not degrade during 49 days of incubation and the ammonium amendment (40 mmol/kg soil) did not affect its persistence. Our results demonstrate that bound-residue formation was a major mechanism for NP dissipation in the red soil under oxic conditions and that chemical nitrogen fertilizer at average field application rate may already considerably increase NP recalcitrance in agricultural soils. -- Highlights:: • Aerobic mineralization of the nonylphenol isomer 4-NP111 in paddy red soil is minor. • Bound-residue formation is the major mechanism for aerobic NP degradation in soil. • The majority of the bound residues of NP are localized in soil humin fraction. • Amendment of soil by ammonium strongly increase the persistence of NP in oxic soil. • Amendment of soil by ammonium does not affect the recalcitrance of NP in anoxic soil. -- Formation of bound residues was the major mechanism in paddy red soil under oxic conditions for nonylphenol dissipation, which was significantly inhibited by amendment with ammonium

  4. Ion mixing, hydration, and transport in aqueous ionic systems

    International Nuclear Information System (INIS)

    The enhancement effect on the ion mobility of fluoride (and that of chloride) in a polycationic system, as the chloride content increases, is shown to also exist in other more simple ionic systems with cations such as the cesium ion and an organic ammonium ion. As the chloride content increases, in addition to the finding that there is more unbound water associated with the cation, we also observe that the average lifetime of a hydrogen bond decreases. This change to the hydrogen bonds is correlated to significant changes to both the structural and dynamical properties of water. The more disordered water structure and faster water dynamics are hypothesized to be also responsible for the enhanced ion mobilities. Furthermore, when either the chloride content or hydration level is changed, the self-diffusion constant of each co-ion changes by almost the same factor, implying the existence of a single universal transport mechanism that determines ion mobilities

  5. Flotation and adsorption of quaternary ammonium salts collectors on kaolinite of different particle size

    Institute of Scientific and Technical Information of China (English)

    Jiang Hao; Liu Guorong; Hu Yuehua; Xu Longhua; Yu Yawen; Xie Zhen; Chen Haochuan

    2013-01-01

    The flotation behaviors of decyltrimethylammonium (103C),dodecyltrimethylammonium chloride (DTAC),tetradecyltrimethylammonium chloride (TTAC) and cetyltrimethylammonium chloride (CTAC) on kaolinite of different particle size fraction were studied.The adsorbed amount and adsorption isotherms of collectors on kaolinite were determined for painstaking investigation into the adsorption of quaternary amines at kaolinite-water interface by ultraviolet spectrophotometer methods.The flotation results show that the flotation recovery of kaolinite of different particle fraction increases with an increase in pH when 103C,DTAC,TrAC and CTAC are used as collectors.As the concentration of collectors increases,the flotation recovery increases.Particle size of kaolinite has a strong effect on flotation.The flotation recovery of fine kaolinite decreases with the carbon chain of quaternary ammonium salts collectors increasing,while coarse kaolinite is on the contrary.The adsorbed amount tests and adsorption isotherms show that adsorbed amount increases when the particle size of kaolinite increases or when the carbon chain length of quaternary ammonium salts increases.Within the range of flotation collector concentration,the longer the hydrocarbon chain,the more probable to be absolutely adsorbed by fine kaolinite particles and then the lower the collector concentration in the bulk,which leds to lower flotation recovery.

  6. Assessment by X-ray diffraction the process of bentonite organophilization using a different quaternary ammonium salts; Avaliacao por difracao de raios X do processo de organofilizacao de uma bentonita utilizando diferentes sais quaternarios de amonio

    Energy Technology Data Exchange (ETDEWEB)

    Silva, L.A. da; Rosario, J.A. do; Lima, R.B.; Milioli, C.C.; Gusatti, M.; Linhares, R.H.; Kuhnen, N.C.; Riella, H.G., E-mail: lasqmc@hotmail.co [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil). Campus Reitor Joao David Ferreira Lima; Cumbane, A.J. [Universidade Eduardo Mondlane (UEM), Maputo (Mozambique)

    2010-07-01

    The process was conducted in an organophilization Bentonite originated from the Company of Industrial Minerals of Mozambique Ltd. (Mimoc). The transformation of bentonite organophilic clay were performed in laboratory procedures that aim to mechanochemical exchange of Na{sup +} and Ca{sup 2+} from the interlayer space of clay minerals by cations of quaternary ammonium salts. In this study we used two types of salts, which are: the cetyl trimethyl ammonium chloride and alkyl dimethyl benzyl ammonium chloride at different concentrations (30, 50, 80, 100 meq/100 g clay). The natural bentonite and organophilic clay samples were characterized by X-ray diffraction (XRD) to obtain the mineralogical constituents and analysis phases of the increase in interlayer distance confirming the incorporation of quaternary ammonium salts in the structure of clays. (author)

  7. Secondary organic material formed by methylglyoxal in aqueous aerosol mimics - Part 1: Surface tension depression and light-absorbing products

    Science.gov (United States)

    Schwier, A. N.; Shapiro, E. L.; Sareen, N.; McNeill, V. F.

    2009-07-01

    We show that methylglyoxal forms light-absorbing secondary organic material in aqueous ammonium sulfate and ammonium nitrate solutions mimicking tropospheric aerosol particles. The light-absorbing products form on the order of minutes, and solution composition continues to change over several days. The results suggest an aldol condensation pathway involving the participation of the ammonium ion. Aqueous solutions of methylglyoxal, with and without inorganic salts, exhibit surface tension depression. Methylglyoxal uptake could potentially change the optical properties, climate effects, and heterogeneous chemistry of the seed aerosol over its lifetime.

  8. Procedure for the obtainment of ammonium uranyl-tricarbonate suitable for the preparation of sinterable UO2

    International Nuclear Information System (INIS)

    Experiments carried out to obtain Ammonium Uranyl-Tricarbonate (AUC) of nuclear purity and with the appropriate physical characteristics to serve as an intermediate stage for the obtainment of sinterable Uranium Dioxide are described. AUC was obtained by precipitation with gaseous ammonium and carbon dioxide from aqueous solutions re-circulation, controlling, in both cases, the flow of the reactive gases, the pH and the temperature. The analyzed working conditions are described, giving also the results from the distribution of the particle size and morphology of the crystals. (M.E.L.)

  9. Natural Nitrogen—15 Abundance of Ammonium Nitrogen and Fixed Ammonium in Soils

    Institute of Scientific and Technical Information of China (English)

    SHISHU-LIAN; XINGGUANG-XI; 等

    1992-01-01

    The present article deals with the natural nitrogen-15 abundance of ammonium nitrogen and fixed ammonium in different soils.Variations in the natural 15N abundance of ammonium nitrogen mineralized in soils under anaerobic incubation condition were related to soil pH.The δ 15N of mineralizable N in acid soils was lower but that in neutral and calcareous soils was higher compared with the δ 15N of total N in the soils.A variation tendence was also found in the δ 15N of amino-acid N in the hydrolysates of soils.The natural 15N abundance of fixed ammonium was higher than that of total N in most surface soils and other soil horizons,indicating that the increase of δ 15N in the soil borizons beneath subsurface horizon of some forest soils and acid paddy soils was related to the higher δ 15N value of fixed ammonium in the soil.

  10. Benchmark binding energies of ammonium and alkyl-ammonium ions interacting with water. Are ammonium-water hydrogen bonds strong?

    Science.gov (United States)

    Vallet, Valérie; Masella, Michel

    2015-01-01

    Alkyl-ammonium ion/water interactions are investigated using high level quantum computations, yielding thermodynamics data in good agreement with gas-phase experiments. Alkylation and hydration lead to weaken the NHsbnd O hydrogen bonds. Upon complete hydration by four water molecules, their main features are close to those of the OHsbnd O bond in the isolated water dimer. Energy decomposition analyses indicate that hydration of alkyl-ammonium ions are mainly due to electrostatic/polarization effects, as for hard monoatomic cations, but with a larger effect of dispersion.

  11. A study on synthetic method and material characteristics of magnesium ammine chloride as ammonia transport materials for solid SCR

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Jong Kook; Yoon, Cheon Seog [Dept. of Mechanical Engineering, Hannam University, Daejeon (Korea, Republic of); Kim, Hong Suk [Engine Research Center, Korea Institute of Machinery and Materials, Daejeon (Korea, Republic of)

    2015-11-15

    Among various ammonium salts and metal ammine chlorides used as solid materials for the sources of ammonia with solid SCR for lean NOx reduction, magnesium ammine chloride was taken up for study in this paper because of its ease of handling and safety. Lab-scale synthetic method of magnesium ammine chloride were studied for different durations, temperatures, and pressures with proper ammonia gas charged, as a respect of ammonia gas adsorption rate(%). To understand material characteristics for lab-made magnesium ammine chloride, DA, IC, FT-IR, XRD and SDT analyses were performed using the published data available in literature. From the analytical results, the water content in the lab-made magnesium ammine chloride can be determined. A new test procedure for water removal was proposed, by which the adsorption rate of lab-made sample was found to be approximately 100%.

  12. Hydrometallurgical extraction of zinc from CaO treated EAF dust in ammonium chloride solution.

    Science.gov (United States)

    Miki, Takahiro; Chairaksa-Fujimoto, Romchat; Maruyama, Katsuya; Nagasaka, Tetsuya

    2016-01-25

    Zinc in Electric Arc Furnace dust or EAF dust mainly exists as ZnFe2O4 and ZnO. While ZnO can be simply dissolved into either an acidic or alkaline solution, it is difficult to dissolve ZnFe2O4. In our previous work, we introduced a process called "CaO treatment", a preliminary pyrometallurgical process designed to transform the ZnFe2O4 in the EAF dust into ZnO and Ca2Fe2O5. The halogens and others heavy metals were favorably vaporized during CaO treatment with no essential evaporation loss of zinc and iron, leaving CaO treated dust which consisted mainly of ZnO and Ca2Fe2O5 and no problematic ZnFe2O4 compound. In this work, the selective leaching of zinc over iron and calcium in the CaO treated dust was investigated using an NH4Cl solution. The effects of temperature, reaction time and NH4Cl concentration on dissolution behavior were examined. While most of the zinc in the CaO treated dust was extracted after 2 h at 70 °C with 2 M NH4Cl, only about 20% of calcium was leached in NH4Cl solution. However, the iron did not dissolve and remained as Ca2Fe2O5 in residue. It was confirmed that zinc can be effectively recovered using NH4Cl solution.

  13. Hydrometallurgical extraction of zinc from CaO treated EAF dust in ammonium chloride solution.

    Science.gov (United States)

    Miki, Takahiro; Chairaksa-Fujimoto, Romchat; Maruyama, Katsuya; Nagasaka, Tetsuya

    2016-01-25

    Zinc in Electric Arc Furnace dust or EAF dust mainly exists as ZnFe2O4 and ZnO. While ZnO can be simply dissolved into either an acidic or alkaline solution, it is difficult to dissolve ZnFe2O4. In our previous work, we introduced a process called "CaO treatment", a preliminary pyrometallurgical process designed to transform the ZnFe2O4 in the EAF dust into ZnO and Ca2Fe2O5. The halogens and others heavy metals were favorably vaporized during CaO treatment with no essential evaporation loss of zinc and iron, leaving CaO treated dust which consisted mainly of ZnO and Ca2Fe2O5 and no problematic ZnFe2O4 compound. In this work, the selective leaching of zinc over iron and calcium in the CaO treated dust was investigated using an NH4Cl solution. The effects of temperature, reaction time and NH4Cl concentration on dissolution behavior were examined. While most of the zinc in the CaO treated dust was extracted after 2 h at 70 °C with 2 M NH4Cl, only about 20% of calcium was leached in NH4Cl solution. However, the iron did not dissolve and remained as Ca2Fe2O5 in residue. It was confirmed that zinc can be effectively recovered using NH4Cl solution. PMID:26448494

  14. Cationic quaternization of cellulose with methacryloyloxy ethyl trimethyl ammonium chloride via ATRP method

    Energy Technology Data Exchange (ETDEWEB)

    Supeno [Cenderawasih University, Jayapura, Papua, Indonesia and School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Daik, Rusli, E-mail: rusli@ukm.edu.my [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); El-Sheikh, Said M. [Nano-Structured Materials Division, Advanced Materials Department, Central Metallurgical Research and Development Institute, Cairo (Egypt)

    2014-09-03

    The synthesis of a cationic cellulose copolymer from cellulose macro-initiator (MCC-BiB) and quaternary compound monomer (METMA) via atom transfer radical polymerization (ATRP) was studied. By using dimethylformamide (DMF), the optimum condition for successful synthesis was at the mole ratio of MCC-BIB:Catalyst:METMA = 1:1:26. The highest copolymer recovery was 93.2 % for 6 h and at 40°C. The copolymer was insoluble in weak polar solvents such as THF and DMF but soluble in methanol and water. The chemistry of cellulose copolymer was confirmed by the FTIR and TGA in which the METMA monomer was used as a reference. The absence of CC bond in the CiB-g-METMA spectrum indicated that graft copolymerization occurred.

  15. 77 FR 47291 - Residues of Didecyl Dimethyl Ammonium Chloride; Exemption From the Requirement of a Tolerance

    Science.gov (United States)

    2012-08-08

    ... September 7, 2011 (76 FR 55329) (FRL- 8886-7), EPA issued a notice pursuant to section 408(d)(3) of FFDCA... Quaternaries can be found at 73 FR 37852 (July 2, 2008). IV. Aggregate Exposures In examining aggregate...- HQ-OPP-2006-0572 determined that risks from aggregate exposure are safe, 72 FR 51180 (September...

  16. Reduction in Ammonium Ions in Sludge Liquor

    Directory of Open Access Journals (Sweden)

    Eglė Šlajūtė

    2013-12-01

    Full Text Available Liquor rejected from the centrifugation of the digested sludge can contain the concentrations of ammonium ions up to 1750 mg/L. These loads are usually returned to the intake of wastewater treatment plants (WWTP without additional treatment and can have a negative impact on biological wastewater and/or sludge treatment processes, e.g. phosphorus and nitrogen removal. This article deals with the use of naturally obtained sorbent, zeolite, in batch and column test procedure for removing ammonium from the rejected liquor. This research study was carried out using different sizes of zeolite particles: 0.8–1.6 mm and 1.6–2.5 mm. The highest efficiency of ammonium removal (up to 98 % was achieved by applying the zeolite particles of 0.8–1.6 mm.Article in Lithuanian

  17. Flow of Aqueous Humor

    Science.gov (United States)

    ... Facebook Twitter Google Plus Email Print this page Flow of Aqueous Humor Most, but not all, forms ... aqueous humor) produced by the eye's ciliary body flows out freely (follow blue arrow). Aqueous humor flows ...

  18. Valyl benzyl ester chloride

    Directory of Open Access Journals (Sweden)

    Grzegorz Dutkiewicz

    2010-02-01

    Full Text Available In the title compound (systematic name: 1-benzyloxy-3-methyl-1-oxobutan-2-aminium chloride, C12H18NO2+·Cl−, the ester group is approximately planar, with a maximum deviation of 0.040 (2 Å from the least-squares plane, and makes a dihedral angle of 28.92 (16° with the phenyl ring. The crystal structure is organized by N—H...Cl hydrogen bonds which join the two components into a chain along the b axis. Pairs of chains arranged antiparallel are interconnected by further N—H...Cl hydrogen bonds, forming eight-membered rings. Similar packing modes have been observed in a number of amino acid ester halides with a short unit-cell parameter of ca 5.5 Å along the direction in which the chains run.

  19. Occupational Exposure in Ammonium Phosphate Fertilizer Plants

    International Nuclear Information System (INIS)

    Occupational exposures and activity concentrations have been assessed in two industrial plants producing mono-ammonium phosphate and di-ammonium phosphate fertilizers, located in south-western Spain. The annual effective doses received by the workers are below 1 mSv/a, with the contribution from external exposure being similar to that from internal exposure. The dose contribution from inhalation of dust has been estimated to be about 0.12 mSv/a, while the 222Rn concentrations inside the plants are of no concern. Consequently, no additional radiation protection measures need to be taken to protect the workers in these facilities. (author)

  20. Main Factors Effecting Anaerobic Ammonium Oxidation

    Institute of Scientific and Technical Information of China (English)

    YANG Xiao-fei

    2014-01-01

    Anaerobic Ammonium Oxidation (ANAMMOX) drew more attentions because of its denitrification in wastewater with low carbon resource. The external conditions of ANAMMOX are relatively harsh,however this reaction does not require the participation of oxygen and organics. So the research and technology development of ANAMMOX has the significance of sustainable development.In this paper, the main influencing factors of ANAMMOX were summarized,Combined with recent research status of ANAMMOX technology, the development trend of the anaerobic ammonium oxidation technology was prospected.

  1. Modeling the use of sulfate additives for potassium chloride destruction in biomass combustion

    OpenAIRE

    Wu, Hao; Grell, Morten Nedergaard; Jespersen, Jacob Boll; Aho, Martti; Jappe Frandsen, Flemming; Glarborg, Peter

    2013-01-01

    Potassium chloride, KCl, formed from biomass combustion may lead to ash deposition and corrosion problems in boilers. Sulfates are effective additives for converting KCl to the less harmful K2SO4. In the present study, the decomposition of ammonium sulfate, aluminum sulfate and ferric sulfate was studied respectively in a fast-heating rate thermogravimetric analyzer (TGA) for deriving a kinetic model. The yields of SO2 and SO3 from the decomposition were studied in a tube reactor, revealing t...

  2. Aqueous foam toxicology evaluation and hazard review

    Energy Technology Data Exchange (ETDEWEB)

    Archuleta, M.M.

    1995-10-01

    Aqueous foams are aggregates of bubbles mechanically generated by passing air or other gases through a net, screen, or other porous medium that is wetted by an aqueous solution of surface-active foaming agents (surfactants). Aqueous foams are important in modem fire-fighting technology, as well as for military uses for area denial and riot or crowd control. An aqueous foam is currently being developed and evaluated by Sandia National Laboratories (SNL) as a Less-Than-Lethal Weapon for the National Institute of Justice (NIJ). The purpose of this study is to evaluate the toxicity of the aqueous foam developed for the NIJ and to determine whether there are any significant adverse health effects associated with completely immersing individuals without protective equipment in the foam. The toxicity of the aqueous foam formulation developed for NIJ is determined by evaluating the toxicity of the individual components of the foam. The foam is made from a 2--5% solution of Steol CA-330 surfactant in water generated at expansion ratios ranging from 500:1 to 1000:1. SteoI CA-330 is a 35% ammonium laureth sulfate in water and is produced by Stepan Chemical Company and containing trace amounts (<0.1%) of 1,4-dioxane. The results of this study indicate that Steol CA-330 is a non-toxic, mildly irritating, surfactant that is used extensively in the cosmetics industry for hair care and bath products. Inhalation or dermal exposure to this material in aqueous foam is not expected to produce significant irritation or systemic toxicity to exposed individuals, even after prolonged exposure. The amount of 1,4-dioxane in the surfactant, and subsequently in the foam, is negligible and therefore, the toxicity associated with dioxane exposure is not significant. In general, immersion in similar aqueous foams has not resulted in acute, immediately life-threatening effects, or chronic, long-term, non-reversible effects following exposure.

  3. Modeling the use of sulfate additives for potassium chloride destruction in biomass combustion

    DEFF Research Database (Denmark)

    Wu, Hao; Grell, Morten Nedergaard; Jespersen, Jacob Boll;

    2013-01-01

    Potassium chloride, KCl, formed from biomass combustion may lead to ash deposition and corrosion problems in boilers. Sulfates are effective additives for converting KCl to the less harmful K2SO4. In the present study, the decomposition of ammonium sulfate, aluminum sulfate and ferric sulfate...... was studied respectively in a fast-heating rate thermogravimetric analyzer (TGA) for deriving a kinetic model. The yields of SO2 and SO3 from the decomposition were studied in a tube reactor, revealing that the ratio of the SO3/SO2 released varied for different sulfate and for ammonium sulfate the ratio...... rate of aluminum. Under the boiler conditions of the present work, the simulation results suggested that the desirable temperature for the ferric sulfate injection was around 950-900oC, whereas for ammonium sulfate the preferable injection temperature was below 800oC....

  4. Modeling the Use of Sulfate Additives for Potassium Chloride Destruction in Biomass Combustion

    DEFF Research Database (Denmark)

    Wu, Hao; Pedersen, Morten Nedergaard; Jespersen, Jacob Boll;

    2014-01-01

    Potassium chloride, KCl, formed from biomass combustion may lead to ash deposition and corrosion problems in boilers. Sulfates are effective additives for converting KCl to the less harmful K2SO4 and HCl. In the present study, the rate constants for decomposition of ammonium sulfate and aluminum......-dependent distribution of SO2 and SO3 from ammonium sulfate decomposition. On the basis of these data as well as earlier results, a detailed chemical kinetic model for sulfation of KCl by a range of sulfate additives was established. Modeling results were compared to biomass combustion experiments in a bubbling...... results, implying a need for further investigations. Predictions for the effectiveness of the sulfur-based additives indicate that ferric sulfate and ammonium sulfate have similar effectiveness at temperatures ranging from approximately 850 to 900 °C, whereas ferric sulfate is more efficient at higher...

  5. Cold Case: Radar investigation of ammonium sulfate cryovolcanism on Titan

    Science.gov (United States)

    Thomann, C.; Hayes, A. G.; Hofgartner, J.; Lunine, J. I.; Le Gall, A.

    2012-12-01

    The detection of a large tidal k2 value from Cassini [1] constitutes very strong evi-dence for a subcrustal ocean, most plausibly dominated by water. However, the secondary constituents are not known. One interesting possibility that has received scant attention in analysis of surface data sets is that the ocean contain aqueous ammonium sulfates, which erupted on the surface in the past to create vast, smooth plains [2]. We adopt the hypothesis that the undifferentiated plains—the "bland-lands" in the mid-latitudes of Titan—are these deposits, and test it using radiometry with SAR data. Lopez et al (this conference) investigate the global distribution and possible origin of this type of unit. We extracted SAR and radiometry-during-SAR data sets from the PDS, and pro-duced maps of brightness temperatures. The SAR imagery was used to identify locations where crossovers exist -some of which are in the undifferentiated plains--and hence where brightness temperatures at different incidence angles are available. We derived emissivities from the data using a simple radiometric model [3] to ac-count for the brightness temperature differences as a function of surface roughness, volume scattering and emissivity. We test the hypothesis by assessing whether the derived emissivities and volume scattering in the bland-lands are consistent with the model cryoclastic ash of ice and ammonium sulfate proposed in [2], distinct from that in other terrains. [1] L. Iess, R.A. Jacobson, M. Ducci, D.J. Stevenson, J.I. Lunine, J.W. Armstrong, S.W. Asmar, P. Racioppa, N.J. Rappaport, P. Tortora, Science, 337, 457 (2012). [2] A.D. Fortes, P.M. Grinrod, S.K. Trickett, L. Vocadlo. Icarus, 188, 139 (2007). [3] T.L. White and J.R. Cogdell. The Moon, 6, 235 (1973).

  6. Chemical reactions at aqueous interfaces

    Science.gov (United States)

    Vecitis, Chad David

    2009-12-01

    Interfaces or phase boundaries are a unique chemical environment relative to individual gas, liquid, or solid phases. Interfacial reaction mechanisms and kinetics are often at variance with homogeneous chemistry due to mass transfer, molecular orientation, and catalytic effects. Aqueous interfaces are a common subject of environmental science and engineering research, and three environmentally relevant aqueous interfaces are investigated in this thesis: 1) fluorochemical sonochemistry (bubble-water), 2) aqueous aerosol ozonation (gas-water droplet), and 3) electrolytic hydrogen production and simultaneous organic oxidation (water-metal/semiconductor). Direct interfacial analysis under environmentally relevant conditions is difficult, since most surface-specific techniques require relatively `extreme' conditions. Thus, the experimental investigations here focus on the development of chemical reactors and analytical techniques for the completion of time/concentration-dependent measurements of reactants and their products. Kinetic modeling, estimations, and/or correlations were used to extract information on interfacially relevant processes. We found that interfacial chemistry was determined to be the rate-limiting step to a subsequent series of relatively fast homogeneous reactions, for example: 1) Pyrolytic cleavage of the ionic headgroup of perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) adsorbed to cavitating bubble-water interfaces during sonolysis was the rate-determining step in transformation to their inorganic constituents carbon monoxide, carbon dioxide, and fluoride; 2) ozone oxidation of aqueous iodide to hypoiodous acid at the aerosol-gas interface is the rate-determining step in the oxidation of bromide and chloride to dihalogens; 3) Electrolytic oxidation of anodic titanol surface groups is rate-limiting for the overall oxidation of organics by the dichloride radical. We also found chemistry unique to the interface, for example: 1

  7. 40 CFR 61.65 - Emission standard for ethylene dichloride, vinyl chloride and polyvinyl chloride plants.

    Science.gov (United States)

    2010-07-01

    ... dichloride, vinyl chloride and polyvinyl chloride plants. 61.65 Section 61.65 Protection of Environment... dichloride, vinyl chloride and polyvinyl chloride plants. An owner or operator of an ethylene dichloride, vinyl chloride, and/or polyvinyl chloride plant shall comply with the requirements of this section....

  8. Synthesis and surface-active property of bis-quaternary ammonium-sodium sulfate Gemini surfactant

    Institute of Scientific and Technical Information of China (English)

    Zhao Qiuling; Gao Zhinong

    2006-01-01

    N,N-dimethyldodecylamine,hydrochloride and epichlorohydrin (molar ration is 2:1:1) were used to synthesize bis-quaternary ammonium Gemini surfactant with a hydroxyl in its spacer group by the one-pot method.This hydroxyl was sulfonated by chlorosulfonic acid and then neutralized to bis-quaternary ammonium-sodium sulfate zwitterionic Gemini surfactant.The yield of the final product was 78%,and the melting point was 231-233℃.Its structure was characterized by IR,1H-NMR,MS,and elemental analyses.The critical micelle concentration (cmc)and surface tension of the novel zwitterionic Gemini surfactant in aqueous solution at 15℃ are 7.2×10-5 mol/L and 34.5 mN/m,respectively.

  9. 76 FR 47238 - Ammonium Nitrate From Russia

    Science.gov (United States)

    2011-08-04

    ...)). Background The Commission instituted this review on March 1, 2011 (76 FR 11273) and determined on June 6, 2011 that it would conduct an expedited review (76 FR 34749, June 14, 2011). The Commission transmitted... COMMISSION Ammonium Nitrate From Russia Determination On the basis of the record \\1\\ developed in the...

  10. 21 CFR 184.1133 - Ammonium alginate.

    Science.gov (United States)

    2010-04-01

    ...: Category of food Maximum level of use in food (as served) (percent) Functional use Confections, frostings... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ammonium alginate. 184.1133 Section 184.1133 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD...

  11. Topaz concentrate desiliconization with ammonium bifluoride

    OpenAIRE

    Andreev, V. A.; Buynovskiy, A. S.; Andreev, Artyom Andreevich; Dyachenko, Alexander Nikolaevich

    2007-01-01

    Fluoridizing agent for the process of topaz concentrate desiliconization has been selected, topaz thermodynamic potentials have been appraised, thermodynamic probabilities of fluorination reaction of topaz concentrate main constituents have been calculated. The results of studying the concentrate desiliconization process with ammonium bifluoride by the methods of thermogravimetry, RFA, microphotography are presented

  12. Detonation characteristics of ammonium nitrate products

    NARCIS (Netherlands)

    Kersten, R.J.A.; Hengel, E.I.V. van den; Steen, A.C. van der

    2006-01-01

    The detonation properties of ammonium nitrate (AN) products depend on many factors and are therefore, despite the large amount of information on this topic, difficult to assess. In order to further improve the understanding of the safety properties of AN, the European Fertilizer Manufacturers Associ

  13. Ammonium ions determination with polypyrrole modified electrode

    Directory of Open Access Journals (Sweden)

    Luiz Henrique Dall´Antonia

    2007-03-01

    Full Text Available The present work relates the preparation of polypyrrole films (PPy deposited on surfaces of glass carbon, nickel and ITO (tin oxide doped with indium on PET plastic, in order to study the ammonium detection. The popypyrrole films were polymerized with dodecylbenzenesulfonate (DBSA on the electrodes, at + 0,70 V vs. Ag/AgCl, based on a solution containing the pyrrole monomer and the amphiphilic salt. Films deposited on glass carbon presented better performance. Cyclic voltammetries, between – 1,50 to + 0,5 V vs. Ag/AgCl, were repeated adding different concentrations of NH4Cl, in order to observe the behavior of the film as a possible detector of ions NH4+. The peak current for oxidation varies with the concentration of ammonium. A linear region can be observed in the band of 0 to 80 mM, with a sensibility (Sppy approximately similar to 4,2 mA mM-1 cm-2, showing the efficacy of the electrodes as sensors of ammonium ions. The amount of deposited polymer, controlled by the time of growth, does not influence on the sensor sensibility. The modified electrode was used to determine ammonium in grounded waters.

  14. 76 FR 46907 - Ammonium Nitrate Security Program

    Science.gov (United States)

    2011-08-03

    ... comments. SUMMARY: This proposed rule would implement anti-terrorism measures to better secure the homeland... purpose of preventing the use of ammonium nitrate in an act of terrorism. This proposed rule seeks comment... Administration POC Point of Contact QATT Qualified Anti-Terrorism Technology RFA Regulatory Flexibility...

  15. Unexpected role of linker position on ammonium gemini surfactant lyotropic gyroid phase stability.

    Science.gov (United States)

    Sorenson, Gregory P; Mahanthappa, Mahesh K

    2016-02-28

    Arising from the water-driven self-assembly of amphiphiles over generally narrow temperature and composition phase windows, aqueous lyotropic liquid crystal (LLC) network phases are useful in applications as therapeutic delivery vehicles and templates for mesoporous material syntheses. While a clear set of amphiphile design rules that enables access to these intricate three-dimensional structures has yet to emerge, recent work indicates that bis(ammonium), bis(phosphonium), and dicarboxylate gemini ("twin tail") surfactants enable enhanced access to LLC network phases such as the double gyroid (G). In order to better understand the scope of this amphiphile design strategy, we investigated the synthesis and aqueous LLC self-assembly behaviors of a homologous series of quaternary gemini bis(ammonium) dichloride surfactants, in which we varied the position of the hydrophobic linker that connects the constituent single tail surfactants. These experiments demonstrate that the position of the linker directly impacts the maximum counterion-headgroup hydration capacity and the extent of counterion-headgroup association, all of which contribute to the aqueous lyotropic double gyroid network phase stability. Thus, judicious selection of the linker position in ionic gemini surfactants provides a new molecular design tool for manipulating LLC network phase stability. PMID:26806651

  16. Phase Separation Behavior and System Properties of Aqueous Two-Phase Systems with Polyethylene Glycol and Different Salts: Experiment and Correlation

    OpenAIRE

    Haihua Yuan; Yang Liu; Wanqian Wei; Yongjie Zhao

    2015-01-01

    The phase separation behaviors of PEG1000/sodium citrate, PEG4000/sodium citrate, PEG1000/ammonium sulfate, and PEG4000/ammonium sulfate aqueous two-phase systems were investigated, respectively. There are two distinct situations for the phase separation rate in the investigated aqueous two-phase systems: one state is top-continuous phase with slow phase separation rate and strong bottom-continuous phase with fast phase separation rate and weak volume ratio dependence. The system properties s...

  17. Quaternary ammonium disinfectants cause subfertility in mice by targeting both male and female reproductive processes.

    Science.gov (United States)

    Melin, Vanessa E; Melin, Travis E; Dessify, Brian J; Nguyen, Christina T; Shea, Caroline S; Hrubec, Terry C

    2016-01-01

    Alkyl dimethyl benzyl ammonium chloride (ADBAC) and didecyl dimethyl ammonium chloride (DDAC) are common ingredients in household bathroom and kitchen cleaning sprays. ADBAC+DDAC cause reproductive toxicity in mice. The aim of the present study was to investigate gender-specific reproductive effects from ADBAC+DDAC. Female reproduction was assessed through ovulation, oocyte implantation, and estrus cycling. Male reproductive function was assessed by sperm concentration, motility, and viability. Numbers of corpora lutea were not different after 2 weeks, but decreased after 8 weeks of ADBAC+DDAC exposure. Dams exposed for 5 weeks to ADBAC+DDAC spent significantly less time in estrus. ADBAC+DDAC exposed males exhibited declines in both sperm concentration and motility, but not sperm viability. Subfertility in mice from ADBAC+DDAC exposure is, therefore, mediated through reproductive disturbances in both females and males. While the effect of ADBAC+DDAC exposure on human health is unclear, widespread exposure necessitates further consideration of their potential reproductive toxicity. PMID:26582257

  18. Sodium chloride, potassium chloride, and virulence in Listeria monocytogenes.

    OpenAIRE

    MYERS, E. R.; Dallmier, A W; Martin, S E

    1993-01-01

    Virulence, as determined in a mouse model, and the virulence factor activities of catalase, superoxide dismutase, and listeriolysin O were examined in a parental strain (10403S) and in a nonhemolytic mutant strain (DP-L224) of Listeria monocytogenes. The cells were propagated in media containing various concentrations of sodium chloride or potassium chloride. Strains 10403S and DP-L224 exhibited significant increases in catalase activity and listeriolysin O activity when grown in medium conta...

  19. SWELLING EQUILIBRIUM OF NONIONIC POLYACRYLAMIDE HYDROGEL IN AQUEOUS SALT SOLUTIONS

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A series of nonionic polyacrylamide hydrogels, using acrylamide as monomer and N,N’-methylene diacrylamide as crosslinking agent, were prepared by the free radical polymerization in aqueous solution. Swelling equilibria for the gels were carried out in aqueous solutions of NaCl, KCl, CaCl2, Na2HPO4 and K2HPO4 with concentration ranging from 10-3 to 5mol/kgH2O at 25℃. Experimental results revealed that the chlorides and phosphates cause a different behavior at higher salt concentration. The swelling ratio increases with increasing concentration of chlorides salts, while decreases with the increased phosphates salt concentration. The phenomena seem to be related to the different interactions of chloride and hydrogen phosphate ions with the network groups. Furthermore, the effects of different concentration of crosslinking agent and total monomers on gel swelling performance were also investigated.

  20. 40 CFR 721.4095 - Quaternary ammonium alkyltherpropyl trialkylamine halides.

    Science.gov (United States)

    2010-07-01

    ... trialkylamine halides. 721.4095 Section 721.4095 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.4095 Quaternary ammonium alkyltherpropyl trialkylamine halides. (a... generically as quaternary ammonium alkyltherpropyl trialkylamine halides (PMNs...

  1. Ammonium-acetate is sensed by gustatory and olfactory neurons in Caenorhabditis elegans.

    Directory of Open Access Journals (Sweden)

    Christian Frøkjaer-Jensen

    Full Text Available BACKGROUND: Caenorhabditis elegans chemosensation has been successfully studied using behavioral assays that treat detection of volatile and water soluble chemicals as separate senses, analogous to smell and taste. However, considerable ambiguity has been associated with the attractive properties of the compound ammonium-acetate (NH(4Ac. NH(4Ac has been used in behavioral assays both as a chemosensory neutral compound and as an attractant. METHODOLOGY/MAIN FINDINGS: Here we show that over a range of concentrations NH(4Ac can be detected both as a water soluble attractant and as an odorant, and that ammonia and acetic acid individually act as olfactory attractants. We use genetic analysis to show that NaCl and NH(4Ac sensation are mediated by separate pathways and that ammonium sensation depends on the cyclic nucleotide gated ion channel TAX-2/TAX-4, but acetate sensation does not. Furthermore we show that sodium-acetate (NaAc and ammonium-chloride (NH(4Cl are not detected as Na(+ and Cl(- specific stimuli, respectively. CONCLUSIONS/SIGNIFICANCE: These findings clarify the behavioral response of C. elegans to NH(4Ac. The results should have an impact on the design and interpretation of chemosensory experiments studying detection and adaptation to soluble compounds in the nematode Caenorhabditis elegans.

  2. Concentration and temperature controlled oxidation and cutting of single-walled carbon nanotubes by ammonium persulfate

    Institute of Scientific and Technical Information of China (English)

    AHMAD; Mirza; Nadeem

    2010-01-01

    SWNTs were oxidized by a simple wet chemical method involving treatment in aqueous ammonium persulfate(APS) solution at a certain temperature.Fourier transform infrared spectroscopy(FTIR) and X-ray photoelectron spectroscopy(XPS) demonstrated that a large amount of oxygen containing groups such as hydroxyl groups and carbonyl groups was attached to the sidewall of SWNTs.The oxidized SWNTs showed good solubility in polar solvents including water and DMF.Atomic force microscopic images showed that SWNTs could be cut into short pipes by the highly concentrated APS solution at 80℃.With the decrease of reaction temperature or APS concentration,the oxidized SWNTs remained uncut.

  3. 21 CFR 184.1296 - Ferric ammonium citrate.

    Science.gov (United States)

    2010-04-01

    ... citrate (iron (III) ammonium citrate) is prepared by the reaction of ferric hydroxide with citric acid, followed by treatment with ammonium hydroxide, evaporating, and drying. The resulting product occurs in two forms depending on the stoichiometry of the initial reactants. (1) Ferric ammonium citrate (iron...

  4. 40 CFR 721.10099 - Dialkyl dimethyl ammonium carbonate (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Dialkyl dimethyl ammonium carbonate... Specific Chemical Substances § 721.10099 Dialkyl dimethyl ammonium carbonate (generic). (a) Chemical... as dialkyl dimethyl ammonium carbonate (1:1) (PMN P-03-715) is subject to reporting under...

  5. Dynamic fluorescence quenching of quinine sulfate dication by chloride ion in ionic and neutral micellar environments

    Science.gov (United States)

    Joshi, Sunita; Varma Y, Tej Varma; Pant, Debi D.

    2014-04-01

    Fluorescence quenching of Quinine sulfate dication (QSD) by chloride-ion (Cl-) in micellar environments of anionic, sodium dodecyl sulfate (SDS), cationic, cetyltrimethylammonium bromide (CTAB) and neutral, triton X-100 (TX-100) in aqueous phase has been investigated by time-resolved and steady- state fluorescence measurements. The quenching follows linear Stern-Volmer relation in micellar solutions and is dynamic in nature.

  6. Oxalyl chloride as a practical carbon monoxide source for carbonylation reactions

    DEFF Research Database (Denmark)

    Hansen, Steffen V F; Ulven, Trond

    2015-01-01

    A method for generation of high-quality carbon monoxide by decomposition of oxalyl chloride in an aqueous hydroxide solution is described. The usefulness of the method is demonstrated in the synthesis of heterocycles and for hydroxy-, alkoxy-, amino-, and reductive carbonylation reactions, in sev...

  7. Chloride channels in stroke

    Institute of Scientific and Technical Information of China (English)

    Ya-ping ZHANG; Hao ZHANG; Dayue Darrel DUAN

    2013-01-01

    Vascular remodeling of cerebral arterioles,including proliferation,migration,and apoptosis of vascular smooth muscle cells (VSMCs),is the major cause of changes in the cross-sectional area and diameter of the arteries and sudden interruption of blood flow or hemorrhage in the brain,ie,stroke.Accumulating evidence strongly supports an important role for chloride (Clˉ) channels in vascular remodeling and stroke.At least three Clˉ channel genes are expressed in VSMCs:1) the TMEM16A (or Ano1),which may encode the calcium-activated Clˉ channels (CACCs); 2) the CLC-3 Clˉ channel and Clˉ/H+ antiporter,which is closely related to the volume-regulated Clˉ channels (VRCCs); and 3) the cystic fibrosis transmembrane conductance regulator (CFTR),which encodes the PKA-and PKC-activated Clˉ channels.Activation of the CACCs by agonist-induced increase in intracellular Ca2+ causes membrane depolarization,vasoconstriction,and inhibition of VSMC proliferation.Activation of VRCCs by cell volume increase or membrane stretch promotes the production of reactive oxygen species,induces proliferation and inhibits apoptosis of VSMCs.Activation of CFTR inhibits oxidative stress and may prevent the development of hypertension.In addition,Clˉ current mediated by gammaaminobutyric acid (GABA) receptor has also been implicated a role in ischemic neuron death.This review focuses on the functional roles of Clˉ channels in the development of stroke and provides a perspective on the future directions for research and the potential to develop Clˉ channels as new targets for the prevention and treatment of stroke.

  8. Origin of unusual sintering phenomena in compacts of chloride-derived 3Y-TZP nanopowders

    Directory of Open Access Journals (Sweden)

    Sweeney Sean M.

    2014-01-01

    Full Text Available After evaluating three alternative possibilities, the present study shows that seemingly minor amounts (at least as low as 0.06 wt% of chlorine impurities are responsible for the poor sintering behavior observed in chloride-derived 3 mol% yttria stabilized zirconia (3Y-TZP nanopowders. Models and quantitative estimates are used to explain the role of evolved HCl and ZrCl4 gases in such anomalous behaviors as reduced sintered densities for higher green densities, de-densification, improved sintering in nitrogen over oxygen, and formation of a dense shell microstructure. Two solutions to problematic residual chlorides are compared: 1 a thermal treatment composed of an extended hold at 1000°C to allow HCl gas removal before the onset of closed porosity, and 2 a chemical treatment performed by washing bisque-fired samples at room temperature using a concentrated ammonium hydroxide solution to remove chlorides. The thermal treatment was found to be superior.

  9. Experimental study of concentrated solutions containing sodium and chloride pollutants in SG flow restricted areas

    International Nuclear Information System (INIS)

    In steam generators, the hideout processes occur in flow restricted areas. Non volatile pollutants, i.e. species less soluble in the vapour phase than in the liquid water phase, accumulate such as sodium hydroxide or sodium chloride. The thermodynamic equilibrium between these two phases is described in terms of liquid-vapour equilibrium constants for soluble species and boiling constant for the solvent. The presented experimental investigation has been realised with the EVA device: the boiling pressure evolution has been measured during the hideout process of sodium hydroxide and sodium chloride aqueous solutions. The results clearly demonstrated that high sodium hydroxide aqueous solutions are thermodynamically possible while with sodium chloride, it seems that precipitation occurs before. (authors)

  10. The Structure of Ammonium D,L-Tartrate

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The single crystals of the title compound NH4+C4H5O6- (C4H9NO6, Mr = 167.1) were obtained from a hot aqueous solution containing L-glutamine and D,L-tartaric acid in mole ratio1:1.5. The crystal belongs to monoclinic space group P21/c with a = 7.646(2), b = 7.804(2), c = 11.502(3)?, β = 102.26(2)o, V = 670.7(3)?3, Z = 4, F(000) = 352, Dc = 1.655 g.cm-3, ((MoK() = 0.16 mm-1, R = 0.035, wR = 0.094 for 1028 observed reflections (I>2((I)). The enatiomeric anions of the tartrate with both (2S,3S)- and (2R,3R)-configuration co-exist in the unit cell. The carbon skeleton assumes a coplanar arrangement with a torsion angle of 181.5o. The three- dimensional H-bonding network exists in the crystal. While tartrate groups link each other by H-bonds between carboxyl and hydroxyl groups, the ammonium cations insert between the tartrate groups to form a sandwich-like crystal structure.

  11. Detonation Properties of Ammonium Dinitramide (ADN)

    Science.gov (United States)

    Wätterstam, A.; Östmark, H.; Helte, A.; Karlsson, S.

    1999-06-01

    Ammonium Dinitramide, ADN, has a potential as an oxidizer for underwater high explosives. Pure ADN has a large reaction-zone length and shows a strong non-ideal behaviour. The work presented here is an extension of previous work.(Sensitivity and Performance Characterization of Ammonium Dinitramide (ADN). Presented at 11th International Detonation Symposium, Snowmass, CO, 1998.) Experiments for determining the detonation velocity as a function of inverse charge radius and density, reaction-zone length and curvature, and the detonation pressure are presented. Measurements of pressure indicates that no, or weak von-Neumann spike exists, suggesting an immediate chemical decomposition. Experimental data are compared with predicted using thermochemical codes and ZND-theory.

  12. Environmental Factors Affecting Ammonium Oxidation Under Iron Reducing Conditions

    Science.gov (United States)

    Jaffe, P. R.; Huang, S.; Ruiz-Urigüen, M.

    2014-12-01

    Ammonium (NH4+) oxidation coupled to iron (Fe) reduction in the absence of oxygen and nitrate/nitrite (NO3-/NO2-) has been reported by several investigators and referred to as Feammox. Feammox is a biological reaction, where Fe(III) is the electron acceptor, which is reduced to Fe(II), and NH4+ is the electron donor, which is oxidized to NO2-. Through a 180-day anaerobic incubation experiment, and using PCR-DGGE, 454-pyosequecing and qPCR analysis, we have shown that an Acidimicrobiaceae bacterium A6, a previously unreported species in the Acidimicrobiaceae family, might be either responsible or plays a key role in the Feammox process, We have enriched these Feammox bacteria (65.8% in terms of cell numbers) in a membrane reactor, and isolated the pure Acidimicrobiaceae bacterium A6 strain in an autotrophic medium. In samples collected and then incubated from a series of local wetland-, upland-, as well as storm-water detention pond-sediments, Feammox activity was only detected in acidic soil environments that contain Fe oxides. Using primers we developed for this purpose, Acidimicrobiaceae bacterium A6 was detected in all incubations where Feammox was observed. Anaerobic incubations of Feammox enrichment cultures adjusted to different pH, revealed that the optimal pH for Feammox is 4 ~ 5, and the reaction does not proceed when pH > 7. Feammox was still proceeding at pH as low as 2. In Feammox culture amended with different Fe(III) sources, Feammox reaction proceeded only when Fe oxides (ferrihydrite or goethite ) were supplied, whereas samples incubated with ferric chloride or ferric citrate showed no measurable NH4+ oxidation. Furthermore, we have also determined from incubation experiments conducted with a temperature gradient (10 ~ 35℃), that the Feammox process was active when the temperature is above 15℃, and the optimal temperature is 20℃. Incubations of enrichment culture with 79% Feammox bacteria appeared to remove circa 8% more NH4+ at 20ºC than at

  13. Development of technology for ammonium nitrate dissociation process

    International Nuclear Information System (INIS)

    Ammonia and ammonium carbonate are frequently used as reagents in fuel production and processing of liquid radioactive wastes. In particular, liquid radioactive wastes that contain ammonium nitrate are generated during operations of metal precipitation. In closed vessels at elevated temperature, for example in evaporators or deposits in tubing, ammonium nitrate may explode due to generation of gaseous nitrogen oxides [2]. In this connection, steps have to be taken to rule out conditions that result in explosion. To do that, ammonium nitrate should be removed even prior to the initial stage of its formation. This report gives results of development of a method of dissociating ammonium nitrate

  14. Secondary organic material formed by methylglyoxal in aqueous aerosol mimics – Part 1: Surface tension depression and light-absorbing products

    Directory of Open Access Journals (Sweden)

    V. F. McNeill

    2009-07-01

    Full Text Available We show that methylglyoxal forms light-absorbing secondary organic material in aqueous ammonium sulfate and ammonium nitrate solutions mimicking tropospheric aerosol particles. The light-absorbing products form on the order of minutes, and solution composition continues to change over several days. The results suggest an aldol condensation pathway involving the participation of the ammonium ion. Aqueous solutions of methylglyoxal, with and without inorganic salts, exhibit surface tension depression. Methylglyoxal uptake could potentially change the optical properties, climate effects, and heterogeneous chemistry of the seed aerosol over its lifetime.

  15. Fluorination of incinerator ash by hydrofluorination or ammonium bifluoride fusion for plutonium recovery

    Energy Technology Data Exchange (ETDEWEB)

    Fink, S.D.; Gray, J.H.; Kent, S.J.; Apgar, S.A.

    1989-01-01

    Incinerator ash containing small quantities of plutonium has been accumulating across the defense complex for many years. Although the total Pu inventory is small, the ash is a nondiscardable residue which presents storage and accountability difficulties. The work discussed here is the result of a joint exploratory effort between members of Savannah River Laboratory and Los Alamos National Laboratory to compare two proposed pyrochemical pretreatments of incinerator ash prior to aqueous processing. These experiments attempted to determine the relative effectiveness of hydrofluorination and ammonium bifluoride fusion as head-end operations for a two step aqueous recovery method. The two pretreatments are being considered as possible second generation enhancements for the New Special Recovery Facility nearing operation at Savannah River Plant. Experimental results and potential engineering concerns are discussed. 3 figs.

  16. Efficient acetylation of primary amines and amino acids in environmentally benign brine solution using acetyl chloride

    Indian Academy of Sciences (India)

    Kaushik Basu; Suchandra Chakraborty; Achintya Kumar Sarkar; Chandan Saha

    2013-05-01

    Acetyl chloride is one of the most commonly available and cheap acylating agent but its high reactivity and concomitant instability in water precludes its use to carry out acetylation in aqueous medium. The present methodology illustrates the efficient acetylation of primary amines and amino acids in brine solution by means of acetyl chloride under weakly basic condition in the presence of sodium acetate and/or triethyl amine followed by trituration with aqueous saturated bicarbonate solution. This effort represents the first efficient use of this most reactive but cheap acetylating agent to acetylate amines in excellent yields in aqueous medium. This is a potentially useful green chemical transformation where reaction takes place in environment-friendly brine solution leading to easy work-up and isolation of the amide derivatives. Mechanistic rationale of this methodology is also important.

  17. Secondary organic material formed by methylglyoxal in aqueous aerosol mimics

    Science.gov (United States)

    Sareen, N.; Schwier, A. N.; Shapiro, E. L.; Mitroo, D.; McNeill, V. F.

    2010-02-01

    We show that methylglyoxal forms light-absorbing secondary organic material in aqueous ammonium sulfate and ammonium nitrate solutions mimicking tropospheric aerosol particles. The kinetics were characterized using UV-Vis spectrophotometry. The results suggest that the bimolecular reaction of methylglyoxal with an ammonium or hydronium ion is the rate-limiting step for the formation of light-absorbing species, with kNH4+II=5×10-6 M-1 min-1 and kH3O+II≤10-3 M-1 min-1. Evidence of aldol condensation products and oligomeric species up to 759 amu was found using chemical ionization mass spectrometry with a volatilization flow tube inlet (Aerosol-CIMS). Tentative identifications of carbon-nitrogen species and a sulfur-containing compound were also made using Aerosol-CIMS. Aqueous solutions of methylglyoxal, with and without inorganic salts, exhibit significant surface tension depression. These observations add to the growing body of evidence that dicarbonyl compounds may form secondary organic material in the aerosol aqueous phase, and that secondary organic aerosol formation via heterogeneous processes may affect seed aerosol properties.

  18. Secondary organic material formed by methylglyoxal in aqueous aerosol mimics

    Directory of Open Access Journals (Sweden)

    N. Sareen

    2010-02-01

    Full Text Available We show that methylglyoxal forms light-absorbing secondary organic material in aqueous ammonium sulfate and ammonium nitrate solutions mimicking tropospheric aerosol particles. The kinetics were characterized using UV-Vis spectrophotometry. The results suggest that the bimolecular reaction of methylglyoxal with an ammonium or hydronium ion is the rate-limiting step for the formation of light-absorbing species, with kNH4+II=5×10−6 M−1 min−1 and kH3O+II≤10−3 M−1 min−1. Evidence of aldol condensation products and oligomeric species up to 759 amu was found using chemical ionization mass spectrometry with a volatilization flow tube inlet (Aerosol-CIMS. Tentative identifications of carbon-nitrogen species and a sulfur-containing compound were also made using Aerosol-CIMS. Aqueous solutions of methylglyoxal, with and without inorganic salts, exhibit significant surface tension depression. These observations add to the growing body of evidence that dicarbonyl compounds may form secondary organic material in the aerosol aqueous phase, and that secondary organic aerosol formation via heterogeneous processes may affect seed aerosol properties.

  19. Nickel electrodeposition from leaching solution containing ammonia and chloride

    Institute of Scientific and Technical Information of China (English)

    郑国渠; 郑利峰; 曹华珍; 高志峰; 倪似愚; 张九渊

    2003-01-01

    The effects of temperature, nickel concentration and current density on the current efficiency and the e-lectrolyzer voltage were investigated in the process of electrowinning nickel. The results show that the current effi-ciency is above 90 % under the various experimental conditions, and the electrolyzer voltage is less than that of tradi-tional electrolyzer system. Therefore, the optimized parameters, i.e. temperature of 50 C, current density of 400A/m2 , are determined. It is also elucidated that anodic product is high valent nickel compound in the process of elec-trodeposition in terms of X-ray diffraction and chemical analysis. The amount of solid product formed on the elec-trode surface decreases with an increase in ammonium chloride concentration by cyclic voltammetry analysis. It is al-so indicated that the anodic gas species are mainly composed of nitrogen by vapor phase chromatograph.

  20. Characterization of incubation experiments and development of an enrichment culture capable of ammonium oxidation under iron reducing conditions

    Science.gov (United States)

    Huang, S.; Jaffé, P. R.

    2014-08-01

    Incubation experiments were conducted using soil samples from a forested riparian wetland where we have previously observed anaerobic ammonium oxidation coupled to iron reduction. Production of both nitrite and ferrous iron were measured repeatedly during incubations when the soil slurry was supplied with either ferrihydrite or goethite and ammonium chloride. Significant changes in the microbial community were observed after 180 days of incubation as well as in a continuous flow membrane reactor, using 16S rRNA gene PCR-denaturing gradient gel electrophoresis, 454-pyrosequencing, and real-time quantitative PCR analysis. We believe that one of the dominant microbial species in our system (an uncultured Acidimicrobiaceae bacterium A6), belonging to the Acidimicrobiaceae family, whose closest cultivated relative is Ferrimicrobium acidiphilum (with 92% identity) and Acidimicrobium ferrooxidans (with 90% identity), might play a key role in this anaerobic biological process that uses ferric iron as an electron acceptor while oxidizing ammonium to nitrite. After ammonium was oxidized to nitrite, nitrogen loss proceeded via denitrification and/or anammox.

  1. Influence of the ammonium salt anion on the synergistic solvent extraction of lanthanides with mixtures of thenoyltrifluoroacetone and tridecylamine

    Energy Technology Data Exchange (ETDEWEB)

    Dukov, I.L.; Jordanov, V.M. [Univ. of Chemical Technology and Metallurgy, Sofia (Bulgaria). Dept. of Inorganic Chemistry

    1998-08-01

    The synergistic solvent extraction of Pr, Gd and Yb with mixtures of thenoyltrifluoroacetone (HTTA) and primary ammonium salt (tridecylammonium chloride or perchlorate, TDAH(Cl, ClO{sub 4})) in C{sub 6}H{sub 6} has been studied. The composition of the extracted species have been determined as Ln(TTA){sub 3}TDAHA(A{sup {minus}} = Cl{sup {minus}} or ClO{sub 4}{sup {minus}}). The values of the equilibrium constant K{sub T,S} have been calculated. The influence of the ammonium salt anion on the extraction process has been discussed. The separation factors of the pairs Gd/Pr and Yb/Gd have been determined.

  2. Review:Anaerobic ammonium oxidation for treatment of ammonium-rich wastewaters

    Institute of Scientific and Technical Information of China (English)

    Lei ZHANG; Ping ZHENG; Chongojian TANG; Ren-cun JIN

    2008-01-01

    The concept of anaerobic ammonium oxidation (ANAMMOX) is presently of great interest.The functional bacteria belonging to the Planctomycete phylum and their metabolism are investigated by microbiologists.Meanwhile,the ANAMMOX is equally valuable in treatment of ammonium-rich wastewaters.Related processes including partial nitritation-ANAMMOX and completely autotrophic nitrogen removal over nitrite (CANON) have been developed,and lab-scale experiments proved that both processes were quite feasible in engineering with appropriate control.Successful full-scale practice in the Netherlands will ac-celerate application of the process in future.This review introduces the microbiology and more focuses on application of the ANAMMOX process.

  3. Stability of succinylcholine chloride injection.

    Science.gov (United States)

    Schmutz, C W; Mühlebach, S F

    1991-03-01

    The stability of succinylcholine chloride injection prepared by a hospital pharmacy was studied under a wide variety of conditions. Batches of succinylcholine chloride injection 10 mg/mL containing sodium chloride, methyl-4-hydroxybenzoate, hydrochloric acid, and water were prepared. Samples were tested for the effect of initial pH (3.0 and 4.2) and sterilization (steam treatment at 100 degrees C for 30 minutes and 121 degrees C for 20 minutes) on stability after three weeks; long-term stability under refrigeration (12, 17, and 23 months of storage at 4 degrees C); and the effect of storage temperature (4-6 degrees C, 20-26 degrees C, 35 degrees C, and 70 degrees C) and light exposure at various intervals up to 12 months. Samples were analyzed by thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC). Unlike heating at 121 degrees C, heating at 100 degrees C produced no significant loss of succinylcholine chloride, independent of the initial pH. Succinylcholine chloride was hydrolyzed only minimally over 23 months if the solution was stored at 4-6 degrees C. A 10% loss of drug content occurred if solutions were kept at 20-26 degrees C for five months, at 35 degrees C for one month, or at 70 degrees C for one day. Initial degradation was slowed if the solution was protected from light. The assessments by TLC proved to be more sensitive than the HPLC measurements. Succinylcholine chloride injection sterilized at 100 degrees C for 30 minutes can be stored for up to five months at room temperature if protected from light. The preparation is stable for at least two years under refrigeration. PMID:2028996

  4. Chloride in vesicular trafficking and function.

    Science.gov (United States)

    Stauber, Tobias; Jentsch, Thomas J

    2013-01-01

    Luminal acidification is of pivotal importance for the physiology of the secretory and endocytic pathways and its diverse trafficking events. Acidification by the proton-pumping V-ATPase requires charge compensation by counterion currents that are commonly attributed to chloride. The molecular identification of intracellular chloride transporters and the improvement of methodologies for measuring intraorganellar pH and chloride have facilitated the investigation of the physiology of vesicular chloride transport. New data question the requirement of chloride for pH regulation of various organelles and furthermore ascribe functions to chloride that are beyond merely electrically shunting the proton pump. This review surveys the currently established and proposed intracellular chloride transporters and gives an overview of membrane-trafficking steps that are affected by the perturbation of chloride transport. Finally, potential mechanisms of membrane-trafficking modulation by chloride are discussed and put into the context of organellar ion homeostasis in general. PMID:23092411

  5. Electrochemical Chloride extraction using external electrodes?

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Pedersen, Anne Juul

    2006-01-01

    Electrochemical methods for the removal of chloride from concrete have been developed and the methods are primarily designed for situations where corrosion has started due to an increased chloride concentration in the vicinity of the reinforcement. In these methods the reinforcement is used...... as the cathode. However, some unwanted side effects can occur, including alkali-silica reaction and in some cases hydrogen embrittlement. It is also suggested also to use electrochemical chloride extraction in a preventive way in constructions where chloride induced corrosion is likely to be a problem after...... a period of time, i.e. remove the chlorides before the chloride front reaches the reinforcement. If the chlorides are removed from outer few centimetres from the surface, the chloride will not reach the reinforcement and cause damage. By using the electrochemical chloride removal in this preventive way...

  6. Review: Mechanisms of ammonium toxicity and the quest for tolerance.

    Science.gov (United States)

    Esteban, Raquel; Ariz, Idoia; Cruz, Cristina; Moran, Jose Fernando

    2016-07-01

    Ammonium sensitivity of plants is a worldwide problem, constraining crop production. Prolonged application of ammonium as the sole nitrogen source may result in physiological and morphological disorders that lead to decreased plant growth and toxicity. The main causes of ammonium toxicity/tolerance described until now include high ammonium assimilation by plants and/or low sensitivity to external pH acidification. The various ammonium transport-related components, especially the non-electrogenic influx of NH3 (related to the depletion of (15)N) and the electrogenic influx of NH4(+), may contribute to ammonium accumulation, and therefore to NH3 toxicity. However, this accumulation may be influenced by increasing K(+) concentration in the root medium. Recently, new insights have been provided by "omics" studies, leading to a suggested involvement of GDP mannose-pyrophosphorylase in the response pathways of NH4(+) stress. In this review, we highlight the cross-talk signaling between nitrate, auxins and NO, and the importance of the connection of the plants' urea cycle to metabolism of polyamines. Overall, the tolerance and amelioration of ammonium toxicity are outlined to improve the yield of ammonium-grown plants. This review identifies future directions of research, focusing on the putative importance of aquaporins in ammonium influx, and on genes involved in ammonium sensitivity and tolerance. PMID:27181951

  7. Crevice corrosion of alloy 22 in fluoride and chloride containing solutions

    International Nuclear Information System (INIS)

    Alloy 22 (N06022) is highly resistant to localized corrosion. Alloy 22 may be susceptible to crevice corrosion in pure chloride (Cl-) solutions under aggressive environmental conditions. The effect of the fluoride (F-) on the susceptibility to crevice corrosion induced by chloride ions is still not well established. The objective of the present work was to explore the crevice corrosion resistance of this alloy to different mixtures of fluorides and chlorides. Cyclic potentiodynamic polarization (CPP) tests were conducted in deaerated aqueous solutions of pure halide ions and also in different mixtures of chloride and fluoride at 90 C degrees and pH 6. The range of chloride concentration [Cl-] was 0.001 M ≤ [Cl-] ≤ 1 M and the range of molar fluoride to chloride ratio [F-]/[Cl-] was 0.1≤ [F-]/[Cl-] ≤ 10. Results showed that Alloy 22 was susceptible to crevice corrosion in all the pure chloride solutions but not in the pure fluoride solutions. A molar ratio [F-]/[Cl-] ranging from 5 to 10 was required for the inhibition of crevice corrosion to be complete in the halide mixtures. A moderate or nil inhibitive effect was observed for molar ratios [F-]/[Cl-] < 5. (author)

  8. Chloride binding of cement-based materials subjected to external chloride environment - A review

    OpenAIRE

    Yuan, Q.; Shi, C; Schutter, G. de; Audenaert, K.; Deng, D.

    2009-01-01

    This paper reviews the chloride binding of cement-based materials subjected to external chloride environments. Chloride ion exist either in the pore solution, chemically bound to the hydration products, or physically held to the surface of the hydration products. Chloride binding of cement-based material is very complicated and influenced by many factors, such as chloride concentration, cement composition, hydroxyl concentration, cation of chloride salt, temperature, supplementary cementing m...

  9. Effects of ammonium ion, acetate and aerobic conditions on hydrogen production and expression levels of nitrogenase genes in Rhodobacter sphaeroides O.U.001

    Energy Technology Data Exchange (ETDEWEB)

    Akkoese, Sevilay; Guenduez, Ufuk; Yuecel, Meral [Middle East Technical University, Department of Biological Sciences, 06531 Ankara (Turkey); Eroglu, Inci [Middle East Technical University, Department of Chemical Engineering, 06531 Ankara (Turkey)

    2009-11-15

    In the present study, expression levels of nitrogenase encoding nifH and control genes nifA and prrA were examined at different physiological conditions in Rhodobacter sphaeroides O.U.001. In addition to variations in expression levels, changes in hydrogen production and growth were also investigated in response to different concentrations of ammonium source, acetate and aerobic conditions. In the present study, increasing concentration of ammonium chloride was found to be caused decrease in hydrogen production. Glutamate containing medium had the capacity for higher hydrogen production. Hydrogen production was observed even in aerobic conditions. The expression levels of nifH and nifA genes decreased with the increasing concentrations of ammonium chloride. Although the expression of nifA was present in the highest concentrations of NH{sub 4}Cl under anaerobic conditions, no expression was observed under aerobic conditions of the same culture conditions. This was likely due to transcriptional level inhibition of nitrogenase in the presence of ammonium ion. Negative correlation was observed between the expression levels of prrA gene and its target, nifA gene. (author)

  10. Stimuli response of polysoap hydrogels in aqueous solution and DC electric fields

    NARCIS (Netherlands)

    Yang, Yajiang; Engberts, Jan B.F.N.

    2000-01-01

    Novel types of polysoap hydrogels based on hydrophobically-modified polyelectrolytes crosslinked with N,N-methylenebisacrylamide have been prepared by free radical polymerization at 70–80°C in aqueous solution with ammonium persulfate as initiator. Poly(diallylamine-co-N,N-dodecylmethyldiallylammoni

  11. [Achievement of Sulfate-Reducing Anaerobic Ammonium Oxidation Reactor Started with Nitrate-Reducting Anaerobic Ammonium Oxidation].

    Science.gov (United States)

    Liu, Zheng-chuan; Yuan, Lin-jiang; Zhou, Guo-biao; Li, Jing

    2015-09-01

    The transformation of nitrite-reducing anaerobic ammonium oxidation to sulfate-reducing anaerobic ammonium oxidation in an UASB was performed and the changes in microbial community were studied. The result showed that the sulfate reducing anaerobic ammonium oxidation process was successfully accomplished after 177 days' operation. The removal rate of ammonium nitrogen and sulfate were up to 58. 9% and 15. 7%, the removing load of ammonium nitrogen and sulfate were 74. 3 mg.(L.d)-1 and 77. 5 mg.(L.d)-1 while concentration of ammonium nitrogen and sulfate of influent were 130 mg.(L.d)-1 and 500 mg.(L.d)-1, respectively. The lost nitrogen and sulphur was around 2 in molar ratio. The pH value of the effluent was lower than that of the influent. Instead of Candidatus brocadia in nitrite reducing anaerobic ammonium oxidation granular sludge, Bacillus benzoevorans became the dominant species in sulfate reducing anaerobic ammonium oxidation sludge. The dominant bacterium in the two kinds of anaerobic ammonium oxidation process is different. Our results imply that the two anaerobic ammonium oxidation processes are carried out by different kind of bacterium. PMID:26717697

  12. Effects of the physical state of tropospheric ammonium-sulfate-nitrate particles on global aerosol direct radiative forcing

    Directory of Open Access Journals (Sweden)

    S. T. Martin

    2003-10-01

    Full Text Available The effect of aqueous versus crystalline sulfate-nitrate-ammonium tropospheric particles on global aerosol direct radiative forcing is assessed. A global three-dimensional chemical transport model predicts sulfate, nitrate, and ammonium aerosol mass. An aerosol thermodynamics model is called twice, once for the upper side (US and once for lower side (LS of the hysteresis loop of particle phase. On the LS, the sulfate mass budget is 40% solid ammonium sulfate, 12% letovicite, 11% ammonium bisulfate, and 37% aqueous. The LS nitrate mass budget is 26% solid ammonium nitrate, 7% aqueous, and 67% gas-phase nitric acid release due to increased volatility upon crystallization. The LS ammonium budget is 45% solid ammonium sulfate, 10% letovicite, 6% ammonium bisulfate, 4% ammonium nitrate, 7% ammonia release due to increased volatility, and 28% aqueous. LS aerosol water mass partitions as 22% effloresced to the gas-phase and 78% remaining as aerosol mass. The predicted US/LS global fields of aerosol mass are employed in a Mie scattering model to generate global US/LS aerosol optical properties, including scattering efficiency, single scattering albedo, and asymmetry parameter. Global annual average LS optical depth and mass scattering efficiency are, respectively, 0.023 and 10.7 m2  (g SO42−−1, which compare to US values of 0.030 and 13.9 m2 (g SO42−−1. Radiative transport is computed, first for a base case having no aerosol and then for the two global fields corresponding to the US and LS of the hysteresis loop. Regional, global, seasonal, and annual averages of top-of-the-atmosphere aerosol radiative forcing on the LS and US (FL and FU, respectively, in W m2− are calculated. Including both anthropogenic and natural emissions, we obtain global annual averages of FL = −0.750, FU = −0.930, and

  13. Efeito do nível energético e da suplementação com cloretos de potássio e de amônia na dieta sobre as respostas fisiológicas e o desempenho de frangos de corte no verão Effect of the energy level and supplementation with potassium and ammonium chlorides in the diet on the physiological parameters and the performance of broiler in the summer

    Directory of Open Access Journals (Sweden)

    Bonifácio Benício de Souza

    2005-02-01

    Full Text Available Realizou-se este estudo com o objetivo de verificar o efeito do nível energético da ração e da suplementação com cloretos de potássio e de amônia na dieta de frangos de corte no verão. Foram utilizados 240 frangos machos, Hubbard, com peso médio inicial de 1204 g, distribuídos num delineamento inteiramente casualizado, em esquema fatorial 2 x 3 x 2, 2 níveis de KCl (0,0% e 1,2% x 3 níveis de NH4Cl (0,0%, 0,2% e 0,4% x 2 níveis de energia (3000 e 3200 Kcal EM/kg de ração, com 4 repetições de 5 aves por repetição. O índice de temperatura do globo negro e umidade (ITGU, observado às 9 horas e 15 horas foi de 76 e 83, respectivamente. Houve interação (P0,05 dos fatores estudados. A ingestão de água aumentou (PTwo hundred and forty male chickens with weight means initial of 1204 g, were utilized and allocated according to a completely randomized design , with treatments arranged in a factorial scheme 2 x 3 x 2, 2 2 levels of KCl (0,0% and 1,2% x 3 levels of NH4Cl (0,0%, 0,2% and 0,4% x 2 levels of Metabolizable Energy (3000 and 3200 Kcal ME/kg of diets, with four replications with five broilers in each. The index of temperature of the black globe and humidity (ITGU was observed at 9:00 and 15:00 hours which was of 76 and 83, respectively. There was a significant interaction (P 0,05 by the treatments studied. The water intake increased (P <0,05 with the addition of KCl in the diet. The feed conversion shown to be better (P <0,05 with the increasing the energy level in the diets and it was worse (P <0,05 at the highest level of chloride of ammonia added in the diets. There was significant interaction (P <0,05 between KCl and the energy level of the diets for feed intake. It was conclude that, studied factors do not affect any of the physiologics parameters studied as well as the broiler performance except for feed conversion that shown better with the by the increasing energy level of the diet and shown to be worse by the

  14. Quaternary Ammonium Polyethyleneimine: Antibacterial Activity Ira

    International Nuclear Information System (INIS)

    Quaternary ammonium polyethyleneimine- (QA-PEI-) based nanoparticles were synthesized using two synthetic methods, reductive amination and N-alkylation. According to the first method, QA-PEI nanoparticles were synthesized by cross-linking with glutaraldehyde followed by reductive amination with octanal and further N-methylation with methyl iodide. The second method is based on crosslinking with dialkyl halide followed by N-alkylation with octyl halide and further N-methylation with methyl iodide. QA-PEI nanoparticles completely inhibited bacterial growth (>106 bacteria), including both Gram-positive, that is, Staphylococcus aureus at 80 μ/mL, and Gram-negative, that is, Escherichia coli at 320 μ/mL. Activity analysis revealed that the degree of alkylation and N-methylation of the QA-PEI nanoparticles plays a significant role in antibacterial activity of the reagent. The most potent compound was octyl alkylated QA-PEI alkylated at 1 : 1 mole ratio (primary amine of PEI monomer units/alkylating agent). Also, cytotoxicity studies on MAT-LyLu and MBT cell lines were performed with QA-PEI nanoparticles. These findings confirm previous reports that poly cations bearing quaternary ammonium moieties inhibit bacterial growth in vitro and have a potential use as additives in medical devices which need antibacterial properties.

  15. Reassimilation of ammonium in Lotus japonicus.

    Science.gov (United States)

    Betti, Marco; García-Calderón, Margarita; Pérez-Delgado, Carmen M; Credali, Alfredo; Pal'ove-Balang, Peter; Estivill, Guillermo; Repčák, Miroslav; Vega, José M; Galván, Francisco; Márquez, Antonio J

    2014-10-01

    This review summarizes the most recent results obtained in the analysis of two important metabolic pathways involved in the release of internal sources of ammonium in the model legume Lotus japonicus: photorespiratory metabolism and asparagine breakdown mediated by aparaginase (NSE). The use of photorespiratory mutants deficient in plastidic glutamine synthetase (GS2) enabled us to investigate the transcriptomics and metabolomic changes associated with photorespiratory ammonium accumulation in this plant. The results obtained indicate the existence of a coordinate regulation of genes involved in photorespiratory metabolism. Other types of evidence illustrate the multiple interconnections existing among the photorespiratory pathway and other processes such as intermediate metabolism, nodule function, and secondary metabolism in this plant, all of which are substantially affected in GS2-deficient mutants because of the impairment of the photorespiratory cycle. Finally, the importance of asparagine metabolism in L. japonicus is highlighted because of the fact that asparagine constitutes the vast majority of the reduced nitrogen translocated between different organs of this plant. The different types of NSE enzymes and genes which are present in L. japonicus are described. There is a particular focus on the most abundant K(+)-dependent LjNSE1 isoform and how TILLING mutants were used to demonstrate by reverse genetics the importance of this particular isoform in plant growth and seed production.

  16. Ammonium nitrate: a promising rocket propellant oxidizer

    Science.gov (United States)

    Oommen; Jain

    1999-06-30

    Ammonium nitrate (AN) is extensively used in the area of fertilizers and explosives. It is present as the major component in most industrial explosives. Its use as an oxidizer in the area of propellants, however, is not as extensive as in explosive compositions or gas generators. With the growing demand for environmental friendly chlorine free propellants, many attempts have been made of late to investigate oxidizers producing innocuous combustion products. AN, unlike the widely used ammonium perchlorate, produces completely ecofriendly smokeless products. Besides, it is one of the cheapest and easily available compounds. However, its use in large rocket motors is restricted due to some of its adverse characteristics like hygroscopicity, near room temperature phase transformation involving a volume change, and low burning rate (BR) and energetics. The review is an attempt to consolidate the information available on the various issues pertaining to its use as a solid propellant oxidizer. Detailed discussions on the aspects relating to phase modifications, decomposition chemistry, and BR and energetics of AN-based propellants, are presented. To make the review more comprehensive brief descriptions of the history, manufacture, safety, physical and chemical properties and various other applications of the salt are also included. Copyright 1999 Elsevier Science B.V.

  17. 1,5-Diaminotetrazolium chloride

    Directory of Open Access Journals (Sweden)

    Ling-Qiao Meng

    2010-04-01

    Full Text Available The title compound, CH5N6+·Cl−, crystallized with two indepedent 1,5-diaminotetrazolium cations and two independent chloride anions in the asymmetric unit. In the crystal, there are a number of N—H...Cl hydrogen-bonding interactions, which generate a three-dimensional network.

  18. Chloride : The queen of electrolytes?

    NARCIS (Netherlands)

    Berend, Kenrick; van Hulsteijn, Leonard Hendrik; Gans, Rijk O. B.

    2012-01-01

    Background: Channelopathies, defined as diseases that are caused by mutations in genes encoding ion channels, are associated with a wide variety of symptoms and have been documented extensively over the past decade. In contrast, despite the important role of chloride in serum, textbooks in general d

  19. [Ion-pair chromatography-indirect ultraviolet detection for determination of tetraethyl ammonium using a monolithic column and a packed column].

    Science.gov (United States)

    Zou, Chunmiao; Zhang, Xiaodong; Yu, Hong; Guan, Chao; Wang, Miaoyu

    2015-07-01

    Two methods were developed for the determination of tetraethyl ammonium by ion-pair chromatography-indirect ultraviolet detection using a monolithic column and a packed column with ionic liquid as additive in mobile phase. Chromatographic separations were performed on a monolithic column and a packed column both on reversed phase using imidazolium ionic liquid aqueous solution-ion-pair reagent-organic solvent as mobile phase. The effects of the background ultraviolet absorption reagent, detection wavelength, ion-pair reagent, organic solvent, column temperature and flow rate on the determination of tetraethyl ammonium were investigated. The difference between the two chromatographic columns was compared and the retention rules were discussed. Under the optimized chromatographic conditions, for tetraethyl ammonium on monolithic column and packed column, the retention times were 2.40 and 3.02 min; the detection limits (S/N=3), 0.04 and 0.07 mg/L; the RSDs (n = 5) for peak areas, 0.16% and 0.11%; and the RSDs (n=5) for retention times, 0.02% and 0.01%, respectively. The two methods have been successfully applied to the determination of tetraethyl ammonium ionic liquids synthesized by laboratory. The recoveries of the tetraethyl ammonium after spiking were 98.2% and 99.1%, respectively. The two methods can meet the requirements for the quantitative analysis of tetraethyl ammonium.

  20. Evaluation of stress corrosion cracking in aqueous solution neutron shield of transport/storage cask for spent fuel

    International Nuclear Information System (INIS)

    Experimental evaluation proved that no chloride induced stress corrosion cracking will occur on the metal cask which utilizes propylene glycol aqueous solution as neutron shield. Crevice corrosion, precursor of cracking, occurs at about 0.4V vs. 0.1M-KCl silver silver-chloride reference electrode in aqueous solution with chloride concentration of more than 5 times higher than limit value. On the other hand, the electrochemical potential (ECP) of cask material was 0.08V in air saturated aqueous solution. Since ECP is much smaller than the crevice corrosion potential below which no crevice corrosion is expected, the possibility is very small for chloride induced stress corrosion cracking to occur on the cask. (author)

  1. Selective removal and inactivation of bacteria by nanoparticle composites prepared by surface modification of montmorillonite with quaternary ammonium compounds.

    Science.gov (United States)

    Khalil, Rowaida K S

    2013-10-01

    The purpose of the present study was to prepare new nanocomposites with antibacterial activities by surface modification of montmorillonite using quaternary ammonium compounds that are widely applied as disinfectants and antiseptics in food-processing environments. The intercalation of four quaternary ammonium compounds namely benzalkonium chloride, cetylpyridinium chloride monohydrate, hexadecyltrimethylammonium bromide, tetraethylammonium chloride hydrate into montmorillonite layers was confirmed by X-ray diffraction. The antibacterial influences of the modified clay variants against important foodborne pathogens differed based on modifiers quantities, microbial cell densities, and length of contact. Elution experiments through 0.1 g of the studied montmorillonite variants indicated that Staphylococcus aureus, Pseudomonas aeroginosa, and Listeria monocytogenes were the most sensitive strains. 1 g of hexadecyltrimethylammonium bromide intercalated montmorillonites demonstrated maximum inactivation of L. monocytogenes populations, with 4.5 log c.f.u./ml units of reduction. In adsorption experiments, 0.1 g of tetraethylammonium chloride hydrate montmorillonite variants significantly reduced the growth of Escherichia coli O157:H7, L. monocytogenes, and S. aureus populations by 5.77, 6.33, and 7.38 log units respectively. Growth of wide variety of microorganisms was strongly inhibited to undetectable levels (food processing plant environments where selectivity in removal and/or inactivation of species in fluid flow streams is desirable. Nevertheless, extensive in vitro and in vivo studies of these new nanocomposites is essential to outpace the understanding of their potential impacts and consequences on human health and the environment if they will make an appearance in commercialized food packaging and containment food materials in the future. PMID:23709187

  2. Antibacterial cotton fibers treated with silver nanoparticles and quaternary ammonium salts.

    Science.gov (United States)

    Kang, Chan Kyu; Kim, Sam Soo; Kim, Soojung; Lee, Jintae; Lee, Jin-Hyung; Roh, Changhyun; Lee, Jaewoong

    2016-10-20

    Cotton fibers were treated chemically with glycidyltrimethylammonium chloride (GTAC), a quaternary ammonium salt, and coated with silver nanoparticles/3-mercaptopropyltrimethoxysilane (3-MPTMS) to increase the antibacterial efficacy. The coating process was accomplished by soaking the cotton fibers into a GTAC solution followed by a dry-cure method, and silver colloid/3-MPTMS solution was then applied at 43°C for 90min. The properties of the cotton fibers were analyzed by scanning electron microscopy, X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis. SEM showed a rough surface when the cotton fibers were treated with GTAC/3-MPTMS/silver nanoparticles due to the increasing surface attachment. The existence of silver and 3-MPTMS on the cotton fibers was confirmed by XPS. The cotton fibers treated with both GTAC and silver nanoparticles showed synergistic antibacterial properties against P. aeruginosa. PMID:27474649

  3. Design requirements for uranium ion exchange from ammonium bicarbonate solutions in a fluidized system

    International Nuclear Information System (INIS)

    A fluidized countercurrent ion-exchange system was developed, operated, and evaluated. The system consisted of integrated multiple-compartment absorption and elution columns in which the solution flows were continuous except for short periods when resin increments were withdrawn. The exchange of uranyl carbonate between a simulated in situ uranium leach liquor and a strong-base ion-exchange resin together with the subsequent elution with an ammonium chloride solution was studied. The effects of the number of sections, section height, amount of resin withdrawal, solution flow rate, and column diameter were investigated. The kinetic and equilibrium relationships for the absorption and elution steps were also examined. The experimental data indicate a strong interdependence between variables. Solution retention time appears to be a major limiting variable in the absorption process, while resin residence time is the determining factor in the elution process. The column was efficient over a range of conditions, but close control was needed for optimum operation. 30 figures

  4. Preparation and Characterization of Montmorillonite Intercalation Compounds with Quaternary Ammonium Surfactant: Adsorption Effect of Zearalenone

    Directory of Open Access Journals (Sweden)

    Yujin Li

    2014-01-01

    Full Text Available Montmorillonite (Mt was used as the original material to prepare intercalation compounds with quaternary ammonium surfactant (QAS. The adsorption of zearalenone (ZEA onto Mt and organomodified Mt was investigated in vitro. Effects of QAS in binding ZEA were studied. By the method of intercalation with dioctadecylmethylbenzylammonium chloride (DOMBAC, the sample exhibited the highest adsorption rate of ZEA (93.2% which was much higher than that of Mt (10.5%. Several methods were adopted to characterize samples, including XRD, TG/DSC, N2 adsorption/desorption, and FTIR. Adsorption isotherm parameters were obtained from Langmuir and Freundlich and the adsorption data fitted better to Langmuir. All results indicate that organomodified Mt has great potential to be a high-performance material to control ZEA contamination.

  5. Stripping study of U(IV) from loaded TBP/n-paraffin using ammonium nitrate as a strippant

    International Nuclear Information System (INIS)

    With the increase in uranium loading in the organic, there was an increase in % stripping of uranium for ammonium nitrate whereas for distilled water it became reversed. With the increase of pH of the aqueous ammonium nitrate solution, it was found that stripping increased up to a pH of 8.5 and after that precipitation starts. Increase in temperature of the biphasic system shows an enhancing effect of uranium stripping. Evaluation of thermodynamic data like ΔH and ΔS indicated that the process is endothermic. Equilibrium isotherms at various operating conditions were generated for both water and ammonium nitrate. Based on the optimized conditions, Mc-Cabe Thiele diagrams were constructed using ammonium nitrate (50 g/L) of pH 7.5 at room temperature. Result showed that at an O/A ratio of 2/5, at least 7 theoretical countercurrent stages are needed at room temperature with an initial uranium loading of 115.4 g/L to get 40 g/L of uranyl nitrate pure solution in the rich end leaving only 3 g/L uranium in the lean solvent whereas for water to strip all the uranium (from 100 g/L) requires only 4 numbers of countercurrent stages at an O/A ratio of 2/3 at room temperature

  6. Microbial reductive dehalogenation of vinyl chloride

    Energy Technology Data Exchange (ETDEWEB)

    Spormann, Alfred M [Stanford, CA; Muller, Jochen A [Baltimore, MD; Rosner, Bettina M [Berlin, DE; Von Abendroth, Gregory [Mannheim, DE; Meshulam-Simon, Galit [Los Angeles, CA; McCarty, Perry L [Stanford, CA

    2014-02-11

    Compositions and methods are provided that relate to the bioremediation of chlorinated ethenes, particularly the bioremediation of vinyl chloride by Dehalococcoides-like organisms. An isolated strain of bacteria, Dehalococcoides sp. strain VS, that metabolizes vinyl chloride is provided; the genetic sequence of the enzyme responsible for vinyl chloride dehalogenation; methods of assessing the capability of endogenous organisms at an environmental site to metabolize vinyl chloride; and a method of using the strains of the invention for bioremediation.

  7. Progress of Carbonation in Chloride Contaminated Concretes

    OpenAIRE

    Wang, Yaocheng; Basheer, P.A.M.; Nanukuttan, S; Bai, Y.

    2016-01-01

    Concretes used in marine environment are generally under the cyclic effect of CO2 and chloride ions (Cl-). To date, the influence of carbonation on ingress of chloride ions in concretes has been widely studied; in comparison, study on the influence of Cl- on the progress of carbonation is limited. During the study, concretes were exposed to independent and combined mechanisms of carbonation and chloride ingress regimes. Profiles of apparent pH and chloride concentration were used to indicate ...

  8. The foam separation of zirconium (IV) from aqueous solutions

    International Nuclear Information System (INIS)

    The foam separation of zirconium(IV) from chloride solutions has been investigated over the 1.8-12 pH range using sodium lauryl sulphate or cetyl(trimethyl)ammonium bromide as collectors. The effects of gas flow rate, bubbling time, collector and zirconium(IV) concentrations, aging of the metal ion, and ionic strength have been studied and the results are discussed in relation to the hydrolytic behaviour of zirconium(IV). Under optimum conditions, ca. 99.5%-removal can be achieved. (orig.)

  9. CHARACTERISTICS OF QUATERNARY AMMONIUM RESISTANT BACTERIA FROM A FINE PAPERMACHINE SYSTEM

    Institute of Scientific and Technical Information of China (English)

    Hweig Wang; ChiYu Huang; ChunHan Ko

    2004-01-01

    To evaluate the biocide effect of quaternary ammonium chloride (QAC), a whitewater sample was taken from a fine papermachine headbox. By plate spreading method, 51 strains of facultative anaerobe were isolated morphologically. Then the strains were separately transferred to basal medium and were incubated before the beginning of log phase. To identify strains with different QAC resistance, 30-120 ppm of N-Alkyl-benzyl-dimethyl ammonium chloride were added to basal medium.Biocide effect was investigated by comparison of bacterial growth, which can be monitored by 600 nm light absorbance of basal medium suspension. Among 51 strains, only 2 strains can Survive for QAC concentration up to 120 ppm. API20E aud 16S rRNA gene sequencing technique were applied to identify two strains with highest (120 ppm)QAC resistance. One strain (HB22)was identified as Morganella morganii. HB22 can resist QAC concentration up to 150 ppm. HB22 is Gram-negative rod, motile with flagella, catalase positive, oxidase negative, Indole positive, H2S production negative, facultative anaerobe. HB22 has optimum growth condition of 35℃ and pH 7.0.HB22 can catabolize only glucose and D (+)-Mannose.The other (HB45) was identified with high similarity among Pseudomonas cf. monteili or Pseudomonas mosselii or Pseudomonas putida. HB45 can resist QAC concentration up to 200 ppm.HB45 is Gram-negative rod, motile with flagella,catalase positive, oxidase negative, Indole negative,H2S production negative, aerobe. HB45 has optimum growth condition of 30℃ and pH 7.4. HB45 can catabolize L-Arabinose, L(+)-Rhanmose, D (+)-Mannose, Glucose, Glycerol, Lactose, Maltose,Raffmose, Xylose, Cellulose and Xylan. The implication of this work to paper industry is also discussed.

  10. Synthesis and characterization of methacrylamidopropyltrimethylammonium chloride and N-substituted acrylamide ionomers

    Directory of Open Access Journals (Sweden)

    2007-11-01

    Full Text Available Quaternary ammonium ionomers of Methacrylamidopropyltrimethyl ammonium chloride with N-substituted acrylamides were prepared at 55±1°C using azobiscyanovaleric acid (ACVA initiator. The monomers and ionomers were characterized by 1H- and 13C-NMR spectroscopy and the copolymer composition was calculated from elemental analysis data. The reduced viscosity of ionomers in methanol behaves as non-polyelectrolytes at lower mole percentage and as polyelectrolyte at higher mole percentage. The molecular weights of ionomers were found to be high and the polydispersity index values indicate termination mainly by disproportionation. The glass transition temperature (Tg of ionomers were greater than those of the corresponding homopolymers, attributed to a reduction in segmental mobility. The initial decomposition temperature (IDT showed that the stability of ionomers increases with increasing mole percentage of ionic content.

  11. Chloride sublimation of gold-arsenic concentrates

    International Nuclear Information System (INIS)

    Present article is devoted to chloride sublimation of gold-arsenic concentrates. The results of studies of chloride sublimation of gold-arsenic comprising concentrates of Chore deposit of Tajikistan are considered. It is found that by application sodium chloride for gold-arsenic comprising concentrates it is possible to extract gold and silver from flotation concentrates.

  12. 21 CFR 172.180 - Stannous chloride.

    Science.gov (United States)

    2010-04-01

    ... Preservatives § 172.180 Stannous chloride. The food additive stannous chloride may be safely used for color... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Stannous chloride. 172.180 Section 172.180 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR...

  13. Soft X-ray absorption spectra of aqueous salt solutions with highly charged cations in liquid microjets

    Energy Technology Data Exchange (ETDEWEB)

    Schwartz, Craig P.; Uejio, Janel S.; Duffin, Andrew M.; Drisdell, Walter S.; Smith, Jared D.; Saykally, Richard J.

    2010-03-11

    X-ray absorption spectra of 1M aqueous solutions of indium (III) chloride, yttrium (III) bromide, lanthanum (III) chloride, tin (IV) chloride and chromium (III) chloride have been measured at the oxygen K-edge. Relatively minor changes are observed in the spectra compared to that of pure water. SnCl{sub 4} and CrCl{sub 3} exhibit a new onset feature which is attributed to formation of hydroxide or other complex molecules in the solution. At higher energy, only relatively minor, but salt-specific changes in the spectra occur. The small magnitude of the observed spectral changes is ascribed to offsetting perturbations by the cations and anions.

  14. Inhibition of biofouling by modification of forward osmosis membrane using quaternary ammonium cation.

    Science.gov (United States)

    Park, Kang-Hee; Yu, Sang-Hyun; Kim, Han-Shin; Park, Hee-Deung

    2015-01-01

    In the operation of the forward osmosis (FO) process, biofouling of the membrane is a potentially serious problem. Development of an FO membrane with antibacterial properties could contribute to a reduction in biofouling. In this study, quaternary ammonium cation (QAC), a widely used biocidal material, was conjugated with a silane coupling agent (3-(trimethoxysilyl)-propyldimethyloctadecyl ammonium chloride) and used to modify an FO membrane to confer antibacterial properties. Fourier transform infrared spectroscopy (FT-IR) demonstrated that the conjugated QAC was successfully immobilized on the FO membrane via covalent bonding. Bacterial viability on the QAC-modified membrane was confirmed via colony count method and visualized via bacterial viability assay. The QAC membrane decreased the viability of Escherichia coli to 62% and Staphylococcus aureus to 77% versus the control membrane. Inhibition of biofilm formation on the QAC modified membrane was confirmed via anti-biofilm tests using the drip-flow reactor and FO unit, resulting in 64% and 68% inhibition in the QAC-modified membrane against the control membrane, respectively. The results demonstrate the effectiveness of the modified membrane in reducing bacterial viability and inhibiting biofilm formation, indicating the potential of QAC-modified membranes to decrease operation costs incurred by biofouling.

  15. Thermal decomposition characteristics of ammonium dinitramide. Part 1; Anmoniumu jinitoramido no netsubunkai tokusei. 1

    Energy Technology Data Exchange (ETDEWEB)

    Takishita, Y.; Teramoto, Y. [Japan Defence Agency, Tokyo (Japan)

    1997-02-28

    At present, the mainstream of the oxidizer of solid propellant used in defense and space exploitation is ammonium perchlorate (AP), while a large amount of hydrogen chloride is generated by AP-based propellant due to chlorine existing in AP molecules. Ammonium dinitramide (ADN) is paid attention recently as a new none-chlorine energetic oxidizer. ADN, with the specific driving force equal to that of AP, is expected as a propellant-oxidizer to meet simultaneously the demands for the improvement of concealment and the prevention of environmental pollution while the high specific driving force is maintained. In this study, thermal decomposition characteristics of ADN is investigated by thermal analysis and mass spectroscopy. The activation energies calculated based on velocity theory are 105kj/mole, 117kj/mole and 151kj/mole respectively at the initial temperature sought from thermal gravity (TG) curve, the peak temperature of decompositing calorification in differential thermal analysis curve, and the temperature from which weight loss is 50% in TG curve. 6 refs., 6 figs., 1 tab.

  16. Hydration Structure of the Quaternary Ammonium Cations

    KAUST Repository

    Babiaczyk, Wojtek Iwo

    2010-11-25

    Two indicators of the hydropathicity of small solutes are introduced and tested by molecular dynamics simulations. These indicators are defined as probabilities of the orientation of water molecules\\' dipoles and hydrogen bond vectors, conditional on a generalized distance from the solute suitable for arbitrarily shaped molecules. Using conditional probabilities, it is possible to distinguish features of the distributions in close proximity of the solute. These regions contain the most significant information on the hydration structure but cannot be adequately represented by using, as is usually done, joint distance-angle probability densities. Our calculations show that using our indicators a relative hydropathicity scale for the interesting test set of the quaternary ammonium cations can be roughly determined. © 2010 American Chemical Society.

  17. KINETICS OF HYDROLYSIS IN AQUEOUS-SOLUTION OF 1-BENZOYL-1,2,4-TRIAZOLE - THE ROLE OF PAIRWISE AND TRIPLET GIBBS ENERGY INTERACTION PARAMETERS IN DESCRIBING THE EFFECTS OF ADDED SALTS AND ADDED ALCOHOLS

    NARCIS (Netherlands)

    NOORDMAN, WH; BLOKZIJL, W; ENGBERTS, JBF; BLANDAMER, MJ

    1995-01-01

    Kinetic data are reported for the spontaneous hydrolysis of 1-benzoyl-1,2,4-triazole in aqueous solutions at ambient-pressure and 298.2 K, in aqueous solutions containing added ethanol, propanol and sodium chloride. Kinetic-data are also reported for the same reaction in aqueous mixtures of sodium c

  18. Kinetics of hydrolysis in aqueous solution of 1-benzoyl-1,2,4-triazole; the role of pairwise and triplet Gibbs energy interaction parameters in describing the effects of added salts and added alcohols

    NARCIS (Netherlands)

    Noordman, Wouter H.; Blokzijl, Wilfried; Engberts, Jan B.F.N.; Blandamer, Michael J.

    1995-01-01

    Kinetic data are reported for the spontaneous hydrolysis of 1-benzoyl-1,2,4-triazole in aqueous solutions at ambient pressure and 298.2 K, in aqueous solutions containing added ethanol, propanol and sodium chloride. Kinetic data are also reported for the same reaction in aqueous mixtures of sodium c

  19. A mathematical model for estimation of distribution in the solvent stripping of uranium from TBP/n-paraffin ammonium nitrate

    International Nuclear Information System (INIS)

    The ammonium nitrate bearing effluent after ADU precipitation can be recycled as strippant in the stripping process of solvent extraction during uranium refining process. The nature of stripping of uranium with various concentration of ammonium nitrate as strippant was studied experimentally and a suitable theoretical model developed for the estimation of Distribution coefficient. The theoretical values of equilibrium constant distribution coefficient was estimated after employing the correction factors due to the activity coefficients each species at higher ionic strength. The activity coefficients of salts in aqueous solution were estimated the correlations developed by 'Bromley' for activity coefficients of multiple salt solutions. The model equations were developed by the mass balance of uranium at equilibrium for biphasic system. Solubility of TBP in water is not considered in the equation so developed. Also the model does not take into account for the ideality of organic phase

  20. Shock compression of polyvinyl chloride

    Science.gov (United States)

    Neogi, Anupam; Mitra, Nilanjan

    2016-04-01

    This study presents shock compression simulation of atactic polyvinyl chloride (PVC) using ab-initio and classical molecular dynamics. The manuscript also identifies the limits of applicability of classical molecular dynamics based shock compression simulation for PVC. The mechanism of bond dissociation under shock loading and its progression is demonstrated in this manuscript using the density functional theory based molecular dynamics simulations. The rate of dissociation of different bonds at different shock velocities is also presented in this manuscript.

  1. Racer (Ammonium Nonanoate) weed control evaluation for onions

    Science.gov (United States)

    Racer has been labeled as a herbicide for food use and is currently under consideration as an organic herbicide for organically grown food crops. The main component (40%) of Racer is ammonium nonanoate (ammonium pelargonate), which occurs in nature and primarily formed from biodegradation of higher...

  2. Ammonium and hydroxylamine uptake and accumulation in Nitrosomonas

    NARCIS (Netherlands)

    Schmidt, I.; Look, C.; Bock, E.; Jetten, M.S.M.

    2004-01-01

    Starved cells of Nitrosomonas europaea and further ammonia oxidizers were able to rapidly accumulate ammonium and hydroxylamine to an internal concentration of about 1 and 0.8 M, respectively. In kinetic studies, the uptake/accumulation rates for ammonium [3.1 mmol (g protein)(-1) min(-1)] and hydro

  3. How to make a living from anaerobic ammonium oxidation

    NARCIS (Netherlands)

    Kartal, B.; De Almeida, N.M.; Maalcke, W.J.; Op den Camp, H.J.M.; Jetten, M.S.M.; Keltjens, J.T.

    2013-01-01

    Anaerobic ammonium-oxidizing (anammox) bacteria primarily grow by the oxidation of ammonium coupled to nitrite reduction, using CO2 as the sole carbon source. Although they were neglected for a long time, anammox bacteria are encountered in an enormous species (micro)diversity in virtually any anoxi

  4. Hydrothermal oxidation of organic wastes using reclaimed ammonium nitrate

    Energy Technology Data Exchange (ETDEWEB)

    Proesmans, P.I.; Luan, L.; Buelow, S.J.

    1996-04-01

    Ammonium nitrate is being studied as an alternative for ammonium perchlorate as an oxidizing agent in Department of Defense 1.1 and 1.3 rocket propellants. Use of ammonium nitrate would eliminate the HCl produced by ammonium perchlorate upon thermal decomposition. To stabilize the ammonium nitrate, which suffers from phase instability, potassium dinitramide (KDN) is added. This increased use of ammonium nitrate will ultimately create a need for environmentally responsible processes to reuse ammonium nitrate extracted from demilitarized rocket motors. Ammonium Nitrate was investigated as an oxidizing agent for methanol, acetic acid and phenol. High removal of organic, ammonia and nitrate was achieved at stoichiometric concentrations. The oxidation of ammonia by nitrate was much faster than the oxidation of either methanol or acetic acid. Phenol, however, was in strong competition with ammonia for the oxidizer (nitrate). Nitrogen products included N{sub 2}, N{sub 2}O, NO{sub 2{sup {minus}}} as well as toxic NO and trace amounts of NO{sub 2}. Carbon products were CO{sub 2}, HCO{sub 3{sup {minus}}}, CO{sub 3}{sup 2{minus}}, and CO.

  5. Bespoke cationic nano-objects via RAFT aqueous dispersion polymerisation

    OpenAIRE

    Williams, M.; Penfold, NJW; Lovett, JR; Warren, NJ; Douglas, CWI; Doroshenko, N; Verstraete, P; Smets, J; Armes, SP

    2016-01-01

    A range of cationic diblock copolymer nanoparticles are synthesised via polymerisation-induced self-assembly (PISA) using a RAFT aqueous dispersion polymerisation formulation. The cationic character of these nanoparticles can be systematically varied by utilising a binary mixture of two macro-CTAs, namely non-ionic poly(glycerol monomethacrylate) (PGMA) and cationic poly[2-(methacryloyloxy)ethyl]trimethylammonium chloride (PQDMA), with poly(2-hydroxypropyl methacrylate) (PHPMA) being selected...

  6. ANALYSIS ON INFLUENCE REGULARITY OF THE AMMONIA-AMMONIUM LEACHING SYSTEM ON LEACHING RATE OF COPPER%不同氨-铵浸出体系对氧化铜矿铜浸出率影响规律的研究

    Institute of Scientific and Technical Information of China (English)

    毛莹博; 方建军; 文娅; 赵文娟; 王珊; 魏志聪

    2012-01-01

    In this paper, through a series of experiment studies about the different ammonia-ammonium coupling of leaching system for the effect of copper oxide ore leaching, a significant influence sequence of the different ammonia-ammonium coupling of leaching system on the leaching rate of copper is determined as following : ammonia-ammonium carbamate > ammonia-ammonium carbonate > ammonia-ammonium chloride > ammonia-ammonium fluoride > ammonia-ammonium bicarbonate > ammonia-ammonium sulfate. The ammonia-ammonium carbamate leaching system is adopted as the experiment study of high calcium and magnesium, low grade and argillaceous copper oxide ore in Xinjiang Water, and the copper leaching rate is as high as 85. 25% .%通过不同氨-铵浸出体系对氧化铜矿浸出影响的试验研究,确定了不同氨-铵浸出体系对铜浸出率的显著性影响顺序是:氨-氨基甲酸铵>氨-碳酸铵>氨-氯化铵>氨-氟化铵>氨-碳酸氢铵>氨-硫酸铵.采用氨-氨基甲酸铵浸出体系对新疆滴水高钙镁低品位泥质氧化铜矿进行浸出试验,铜浸出率高达85.25%.

  7. Seasonal patterns of ammonium regeneration from size-fractionated microheterotrophs

    Science.gov (United States)

    Maguer, Jean-François; L'Helguen, Stéphane; Madec, Christian; Le Corre, Pierre

    1999-11-01

    Ammonium regeneration by size-fractionated plankton was measured for 1 year at a coastal station in the shallow well-mixed waters of the western English Channel. Rates of ammonium regeneration in the Journal of Plankton Research, 18, 355-370). Total ammonium regenerated in a year by the microheterotrophs was 15 g N m -2, equivalent to about 60% of the total nitrogen uptake. Microplankton (200-15 μm) accounted for about 50% of the regeneration measured between early spring and late summer. Percent contribution of nanoplankton to total ammonium regeneration varied considerably between the seasons, from very high (83-88%) levels in winter to very low (2-13%) levels in summer. Contribution by picoplankton (nano- and picoplankton fractions, appears to be different from that in deep well-mixed waters. Here, the relative contribution of ciliates and bacteria to ammonium regeneration shows little variation with an increase in macrozooplankton biomass.

  8. Differentiation of energy expenditure of membrane electrochemical utilization of lithium chloride in polymeric fibers production

    International Nuclear Information System (INIS)

    Electric power consumption for preparation of lithium hydroxide aqueous solution for regeneration stage in production of polymer fibers in a wide range of catholyte volumetric consumption has been calculated by the data of laboratory experiments, the results are presented. Energy consumption for lithium ions transfer through the Nafion membrane has been separated. It is shown that under stationary conditions of lithium chloride aqueous solution electrolysis and at current loading on the membrane approximately up to 1 kA x m-2 the drifting lithium ions can not upset preliminary flooding of the membrane. 10 refs.; 3 figs.; 1 tab

  9. Studies on Acetone Powder and Purified Rhus Laccase Immobilized on Zirconium Chloride for Oxidation of Phenols

    Directory of Open Access Journals (Sweden)

    Rong Lu

    2012-01-01

    Full Text Available Rhus laccase was isolated and purified from acetone powder obtained from the exudates of Chinese lacquer trees (Rhus vernicifera from the Jianshi region, Hubei province of China. There are two blue bands appearing on CM-sephadex C-50 chromatography column, and each band corresponding to Rhus laccase 1 and 2, the former being the major constituent, and each had an average molecular weight of approximately 110 kDa. The purified and crude Rhus laccases were immobilized on zirconium chloride in ammonium chloride solution, and the kinetic properties of free and immobilized Rhus laccase, such as activity, molecular weight, optimum pH, and thermostability, were examined. In addition, the behaviors on catalytic oxidation of phenols also were conducted.

  10. Study on antibacterial dental resin using tri-n-butyl(4-vinylbenzyl)phosphonium chloride.

    Science.gov (United States)

    Kurata, Shigeaki; Hamada, Nobushiro; Kanazawa, Akihiko; Endo, Takeshi

    2011-01-01

    The antibacterial properties of a polymeric phosphonium salt were studied to determine its suitability as an additive to develop an antibacterial dental resin. The phosphonium salt monomer studied was tri-n-butyl(4-vinylbenzyl)phosphonium chloride (VP), and acrylic acid (AC) and methacryloyloxyethyl trimethyl ammonium chloride (MA) were used as controls. The antibacterial activity of these monomers and their corresponding polymers (PVP, PAC, and PMA) against Streptococcus mutans (S. mutans) was examined. When incubating S. mutans in a medium containing 10 μmol/mL for 24 hours, the antibacterial activity of PVP against S. mutans was high, while the antibacterial activity of PMA and VP was lower. AC, PAC and PMA exhibited the lowest antibacterial activity. The mechanical properties of the copolymers of methyl methacrylate, 2-hydroxyethyl methacrylate, and VP decreased as VP content increased, and were lower than those of poly(methyl methacrylate).

  11. Crystal structure of tetraethylammonium chloride 3,4,5,6-tetrafluoro-1,2-diiodobenzene

    OpenAIRE

    Jasmine Viger-Gravel; Ilia Korobkov; Bryce, David L.

    2015-01-01

    Equimolar quantities of tetraethylammonium chloride (Et4NCl) and 3,4,5,6-tetrafluoro-1,2-diiodobenzene (o-DITFB or o-C6F4I2) have been co-crystallized in a solution of dichloromethane yielding a pure halogen-bonded compound, 3,4,5,6-tetrafluoro-1,2-diiodobenzene–tetraethyl ammonium chloride (2/1), Et4N+·Cl−·2C6F4I2, in the form of translucent needles. [(Et4NCl)(o-C6F4I2)2] packs in the C2/c space group. The asymmetric unit includes one molecule of DITFB, one Et4N+ cation located on a twofold ...

  12. Density functional theory calculations of the molecular structure and the vibrational spectra of bis-tetrapropyl-ammonium hexachloro-dizincate

    Science.gov (United States)

    Ben Gzaiel, M.; Oueslati, A.; Chaabane, I.; Gargouri, M.

    2016-10-01

    The molecular structure and vibrational spectra of bis-tetrapropyl-ammonium hexachloro-dizincate in the ground state have been investigated by density functional method (DFT) using the B3LYP method with the LanL2DZ and LanL2MB basis set. Infrared and Raman spectroscopes of the [N(C3H7)4]2Zn2Cl6 compound have been measured at room temperature in the frequencies range (3500-400 cm-1) and (3500-100 cm-1), respectively. The optimized geometric shows that the calculated values obtained by B3LYP/LanL2DZ basis are in much better agreement with the experimental data than those obtained by B3LYP/LanL2MB. Actually the theoretical vibrational spectra (B3LYP/LanL2DZ) of the title compound have been interpreted by means of potential energy distribution (PED) which is in good agreement with the experimental data. The comparison of the infrared spectrum of the tetrapropyl-ammonium chloride ligand with those of the bis-tetrapropyl-ammonium hexachloro-dizincate compound confirms an increase of the wavenumber in the [N(C3H7)4]2Zn2Cl6 compound. This can be explained by an increase of the electrostatic interactions of the [N(C3H7)4]Cl ligand.

  13. Determination of chloride in brazilian crude oils by ion chromatography after extraction induced by emulsion breaking.

    Science.gov (United States)

    Robaina, Nicolle F; Feiteira, Fernanda N; Cassella, Alessandra R; Cassella, Ricardo J

    2016-08-01

    The present paper reports on the development of a novel extraction induced by emulsion breaking (EIEB) method for the determination of chloride in crude oils. The proposed method was based on the formation and breaking of oil-in-water emulsions with the samples and the consequential transference of the highly water-soluble chloride to the aqueous phase during emulsion breaking, which was achieved by centrifugation. The determination of chloride in the extracts was performed by ion chromatography (IC) with conductivity detection. Several parameters (oil phase:aqueous phase ratio, crude oil:mineral oil ratio, shaking time and type and concentration of surfactant) that could affect the performance of the method were evaluated. Total extraction of chloride from samples could be achieved when 1.0g of oil phase (0.5g of sample+0.5g of mineral oil) was emulsified in 5mL of a 2.5% (m/v) solution of Triton X-114. The obtained emulsion was shaken for 60min and broken by centrifugation for 5min at 5000rpm. The separated aqueous phase was collected, filtered and diluted before analysis by IC. Under these conditions, the limit of detection was 0.5μgg(-1) NaCl and the limit of quantification was 1.6μgg(-1) NaCl. We applied the method to the determination of chloride in six Brazilian crude oils and the results did not differ statistically from those obtained by the ASTM D6470 method when the paired Student-t-test, at 95% confidence level, was applied.

  14. Determination of chloride in brazilian crude oils by ion chromatography after extraction induced by emulsion breaking.

    Science.gov (United States)

    Robaina, Nicolle F; Feiteira, Fernanda N; Cassella, Alessandra R; Cassella, Ricardo J

    2016-08-01

    The present paper reports on the development of a novel extraction induced by emulsion breaking (EIEB) method for the determination of chloride in crude oils. The proposed method was based on the formation and breaking of oil-in-water emulsions with the samples and the consequential transference of the highly water-soluble chloride to the aqueous phase during emulsion breaking, which was achieved by centrifugation. The determination of chloride in the extracts was performed by ion chromatography (IC) with conductivity detection. Several parameters (oil phase:aqueous phase ratio, crude oil:mineral oil ratio, shaking time and type and concentration of surfactant) that could affect the performance of the method were evaluated. Total extraction of chloride from samples could be achieved when 1.0g of oil phase (0.5g of sample+0.5g of mineral oil) was emulsified in 5mL of a 2.5% (m/v) solution of Triton X-114. The obtained emulsion was shaken for 60min and broken by centrifugation for 5min at 5000rpm. The separated aqueous phase was collected, filtered and diluted before analysis by IC. Under these conditions, the limit of detection was 0.5μgg(-1) NaCl and the limit of quantification was 1.6μgg(-1) NaCl. We applied the method to the determination of chloride in six Brazilian crude oils and the results did not differ statistically from those obtained by the ASTM D6470 method when the paired Student-t-test, at 95% confidence level, was applied. PMID:27388656

  15. Novel approach for the ammonium removal by simultaneous heterotrophic nitrification and denitrification using a novel bacterial species co-culture.

    Science.gov (United States)

    Angar, Yassmina; Kebbouche-Gana, Salima; Djelali, Nacer-Eddine; Khemili-Talbi, Souad

    2016-03-01

    Agricultural activities lead excessive emission of ammonia nitrogen in the environment and can profoundly interfere the equilibrium of the natural ecosystems leading to their contamination. Actually, the biological purification of wastewaters is the most adopted technique thanks to its several advantages such as high performance and low energy consumption. For this reason, two novel strains of Alcaligenes sp. S84S3 and Proteus sp. S19 genus were isolated from an activated sludge and applied in the treatment of ammonium and nitrite in aqueous solution. Under the optimum operating conditions of temperature (30 °C), pH (7), carbon substrate (2 g/L of glucose) and duration of incubation time (69 h), the strain Alcaligenes sp. S84S3 could oxidize 65% of the ammonium as high as 272.72 mg-NH4(+)/L. Moreover, during 48 h, the nitrate reduction rate performed by the strain Proteus S19 was about 99 % without production of nitrite intermediate (negligible concentration). Moreover, the coculture of the strains Alcaligenes sp. S84S3 and Proteus sp. S19 could eliminate 65.83% of the ammonium ions without production of toxic forms of nitrogen oxides during a short time of incubation (118 h) at the same operational conditions with providing the aeration in the first treatment phase. The coculture of our isolated strains is assumed to have a good potential for nitrification and denitrification reactions applied in the treatment of wastewater containing ammonium, nitrite and nitrate. As a result, we can consider that the mixed culture is a practical method in the treatment of high-strength ammonium wastewater with reducing of sludge production.

  16. Population of Nitrifying Bacteria and Nitrification in Ammonium Saturated Clinoptilolite

    Science.gov (United States)

    McGilloway, R. L.; Weaver, R. W.; Ming, Douglas W.; Gruener, J.

    1999-01-01

    As humans begin to spend longer periods of time in space, plants will be incorporated into life support systems. Ammonium saturated clinoptilolite is one plant growth substrate but a balance between ammonium and nitrate is needed. A laboratory study was conducted to determine effects of nitrifying bacteria on ammonium concentrations and kinetics of nitrification. Columns containing clinoptilolite substrate amended with nitrifying bacteria obtained from soil enrichment were analyzed weekly for a 90 day period. The enrichment culture initially contained 1 x 10(exp 5) ammonium oxidizing bacteria and 1 x 10(exp 2) nitrite oxidizing bacteria per gram of substrate. Populations of ammonium oxidizing bacteria increased to 1 x 10(exp 6) and nitrite oxidizing bacteria increased to 1 x 10(exp 3) per gram of substrate. The nitrification rate was approximately 0.25mg NO3(-)-N/kg.hr. Experiments were also conducted to enumerate nitrifying bacteria in a clinoptilolite substrate used to grow wheat (Triticum aestivum L.). Seventy days following the initial inoculation with an unknown number of commercial nitrifying bacteria, 1 x 10(exp 5) ammonium oxidizing bacteria per gram of substrate were present. The number of nitrite oxidizing bacteria was between 1 x 10(exp 3) to 10(exp 4) per gram of substrate as measured by the most probable number method. Nitrification rates were approximately 0.20mg NO3(-)-N/kg.hr. Clinoptilolite readily exchanged sufficient concentrations of ammonium to support nitrifying bacteria and they survived well in this medium.

  17. Chloride adsorption by calcined layered double hydroxides in hardened Portland cement paste

    KAUST Repository

    Yoon, Seyoon

    2014-06-01

    This study investigated the feasibility of using calcined layered double hydroxides (CLDHs) to prevent chloride-induced deterioration in reinforced concrete. CLDHs not only adsorbed chloride ions in aqueous solution with a memory effect but also had a much higher binding capacity than the original layered double hydroxides (LDHs) in the cement matrix. We investigated this adsorption in hardened cement paste in batch cultures to determine adsorption isotherms. The measured and theoretical binding capacities (153 mg g -1 and 257 mg g-1, respectively) of the CLDHs were comparable to the theoretical capacity of Friedel\\'s salt (2 mol mol-1 or 121 mg g-1), which belongs to the LDH family among cementitious phases. We simulated chloride adsorption by CLDHs through the cement matrix using the Fickian model and compared the simulation result to the X-ray fluorescence (XRF) chlorine map. Based on our results, it is proposed that the adsorption process is governed by the chloride transport through the cement matrix; this process differs from that in an aqueous solution. X-ray diffraction (XRD) analysis showed that the CLDH rebuilds the layered structure in a cementitious environment, thereby demonstrating the feasibility of applying CLDHs to the cement and concrete industries. © 2014 Published by Elsevier B.V. All rights reserved.

  18. The foam separation of thorium(IV) from dilute aqueous solutions

    International Nuclear Information System (INIS)

    The foam separation of thorium(IV) from the dilute aqueous solutions was investigated at pH values ranging from 1.2 to 12 using the cationic surfactant cetyl trimethyl ammonium bromide and the anionic collector sodium lauryl sulphate. Cetyl trimethyl ammonium bromide could not remove soluble thorium but partially floated the hydrous oxide. The percentage removal was found to depend on the pH. With sodium lauryl sulphate, removals approaching 100% could be achieved at all the pH values tested. The various factors that can affect the separation process investigated and the results are discussed in terms of the hydrolysis of thorium. (orig.)

  19. Chloride adsorption by calcined layered double hydroxides in hardened Portland cement paste

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Seyoon [School of Engineering, Kings College, University of Aberdeen, Aberdeen AB24 3UE (United Kingdom); Moon, Juhyuk, E-mail: juhyuk.moon@stonybrook.edu [Civil Engineering Program, Department of Mechanical Engineering, State University of New York at Stony Brook, New York 11794 (United States); Bae, Sungchul [Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720 (United States); Duan, Xiaonan [Department of Materials Science and Engineering, Cornell University, Ithaca, NY 14853 (United States); Giannelis, Emmanuel P. [Department of Materials Science and Engineering, Cornell University, Ithaca, NY 14853 (United States); Center for Refining and Petrochemicals, The Research Institute, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Monteiro, Paulo M. [Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720 (United States)

    2014-06-01

    This study investigated the feasibility of using calcined layered double hydroxides (CLDHs) to prevent chloride-induced deterioration in reinforced concrete. CLDHs not only adsorbed chloride ions in aqueous solution with a memory effect but also had a much higher binding capacity than the original layered double hydroxides (LDHs) in the cement matrix. We investigated this adsorption in hardened cement paste in batch cultures to determine adsorption isotherms. The measured and theoretical binding capacities (153 mg g{sup −1} and 257 mg g{sup −1}, respectively) of the CLDHs were comparable to the theoretical capacity of Friedel's salt (2 mol mol{sup −1} or 121 mg g{sup −1}), which belongs to the LDH family among cementitious phases. We simulated chloride adsorption by CLDHs through the cement matrix using the Fickian model and compared the simulation result to the X-ray fluorescence (XRF) chlorine map. Based on our results, it is proposed that the adsorption process is governed by the chloride transport through the cement matrix; this process differs from that in an aqueous solution. X-ray diffraction (XRD) analysis showed that the CLDH rebuilds the layered structure in a cementitious environment, thereby demonstrating the feasibility of applying CLDHs to the cement and concrete industries. - Highlights: • We examine the adsorption equilibrium and kinetics of CLDH in the hydrated cement. • CLDH capacity to bind chloride ions in the hydrated cement paste is determined. • We model chloride adsorption by CLDH through the cement matrix. • CLDH reforms the layered structure with ion adsorption in the cement matrix.

  20. Chloride adsorption by calcined layered double hydroxides in hardened Portland cement paste

    International Nuclear Information System (INIS)

    This study investigated the feasibility of using calcined layered double hydroxides (CLDHs) to prevent chloride-induced deterioration in reinforced concrete. CLDHs not only adsorbed chloride ions in aqueous solution with a memory effect but also had a much higher binding capacity than the original layered double hydroxides (LDHs) in the cement matrix. We investigated this adsorption in hardened cement paste in batch cultures to determine adsorption isotherms. The measured and theoretical binding capacities (153 mg g−1 and 257 mg g−1, respectively) of the CLDHs were comparable to the theoretical capacity of Friedel's salt (2 mol mol−1 or 121 mg g−1), which belongs to the LDH family among cementitious phases. We simulated chloride adsorption by CLDHs through the cement matrix using the Fickian model and compared the simulation result to the X-ray fluorescence (XRF) chlorine map. Based on our results, it is proposed that the adsorption process is governed by the chloride transport through the cement matrix; this process differs from that in an aqueous solution. X-ray diffraction (XRD) analysis showed that the CLDH rebuilds the layered structure in a cementitious environment, thereby demonstrating the feasibility of applying CLDHs to the cement and concrete industries. - Highlights: • We examine the adsorption equilibrium and kinetics of CLDH in the hydrated cement. • CLDH capacity to bind chloride ions in the hydrated cement paste is determined. • We model chloride adsorption by CLDH through the cement matrix. • CLDH reforms the layered structure with ion adsorption in the cement matrix

  1. Modelling an Ammonium Transporter with SCLS

    Directory of Open Access Journals (Sweden)

    Angelo Troina

    2009-10-01

    Full Text Available The Stochastic Calculus of Looping Sequences (SCLS is a recently proposed modelling language for the representation and simulation of biological systems behaviour. It has been designed with the aim of combining the simplicity of notation of rewrite systems with the advantage of compositionality. It also allows a rather simple and accurate description of biological membranes and their interactions with the environment.In this work we apply SCLS to model a newly discovered ammonium transporter. This transporter is believed to play a fundamental role for plant mineral acquisition, which takes place in the arbuscular mycorrhiza, the most wide-spread plant-fungus symbiosis on earth. Due to its potential application in agriculture this kind of symbiosis is one of the main focuses of the BioBITs project. In our experiments the passage of NH3 / NH4+ from the fungus to the plant has been dissected in known and hypothetical mechanisms; with the model so far we have been able to simulate the behaviour of the system under different conditions. Our simulations confirmed some of the latest experimental results about the LjAMT2;2 transporter. The initial simulation results of the modelling of the symbiosis process are promising and indicate new directions for biological investigations.

  2. New quaternary ammonium salts based decontaminants

    Directory of Open Access Journals (Sweden)

    Diana M. Popescu

    2014-06-01

    Full Text Available Decontamination after terrorist attacks or industrial accidents with biological and/or chemical agents („bio-chem“ must be fast and efficient, in order to reduce the number of victims and to eliminate the consequent damages. The decontamination of living biological agents (bacteria, viruses or nonliving ones (toxins, regulators and toxic chemicals could be accomplished by reactions of hydrolysis in various experimental conditions, in particular in alkaline medium, reactions with amines or ammonia, alcohols, phenols etc. and by their transformation into less toxic degradation products. “Bio-chem” intentional or unintentional contamination is a real risk, towards which an effective management must be available to prevent and control it. Decontamination is an essential measure to protect the personnel and the environment. Synthesis and testing of new „bio-chem“ decontaminants, based on quaternary ammonium salts, complete the arsenal of protection against chemical and biological agents. The most effective selected substances could be produced and used for decontamination in accordance with legal procedures

  3. Correlation of anaerobic ammonium oxidation and denitrification

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The feasibility of the nitrous organic wastewater treated was studied in seven anaerobic sequencing batch reactors(ASBRs)(0 #-6 #) which had been run under stable anaerobic ammonium oxidation (Anammox). By means of monitoring and data analysis of COD, NH4+-N, NO2--N, NO3--N and pH, and of microbial test, the results revealed that the optimal Anammox performance was achieved from 2# reactor in which COD/NH4+-N was 1.65, Anammox bacteria and denitrification bacteria could coexist, and Anammox reaction and denitrification reaction could occur simultaneously in the reactors. The ratio of NH4+-N consumed: NO2--N consumed: NO3--N produced was 1:1.38:0.19 in 0# reactor which was not added glucose in the wastewater. When different ratio of COD and NH4+-N was fed for the reactors, the ratio of NO2--N consumed: NH4+-N consumed was in the range of 1.51-2.29 and the ratio of NO3-N produced: NH4+-N consumed in the range of 0-0.05.

  4. Determination of ammonium and organic bound nitrogen by inductively coupled plasma emission spectroscopy.

    Science.gov (United States)

    Jaber, A M Y; Mehanna, N A; Sultan, S M

    2009-06-15

    The continuous flow sample introduction technique with a hydride generator system in conjunction with an inductively coupled plasma emission spectrometer (ICP-AES-HG), is used in this study for quantitative determination of ammonium and organic bound nitrogen in aqueous and solid samples. Ammonia vapor released from ammonium salt after treatment with concentrated NaOH is transferred by argon to plasma for detection at 174.273 nm using axial argon plasma mode. The calibration curves were linear within a range of 25-1000 mg L(-1)N as ammonium molybdate with correlation coefficients of better than 0.99 and limits of detection of about 10-25mg L(-1)N. The percent recovery of N (25-500 mg L(-1)N) in soft (distilled) water and high salt content (1.7 mol L(-1) NaCl) matrices was found to be in the range of about 97-102% with %RSD in the range of 4.6-0.62. The sensitivity, limit of detection, and blank contribution from the atmospheric nitrogen, were tremendously improved in this method compared with the available ICP-AES spray chamber counterpart. Furthermore, the ICP-AES-HG method gave results for real samples (soil, fertilizer, waste water) containing about 50-1800 mg L(-1)N in good agreement with those obtained by the standard Kjeldahl method. No statistical differences at the 95% confidence level on applying the t-test were observed between the values obtained by the two methods. Thus, the ICP-AES-HG method is reliable and faster than the conventional tedious Kjeldahl method, superior to the ICP-AES spray chamber method, and almost free from matrix interference which is usually a critical factor in atomic emission spectroscopic techniques.

  5. Recovery of ammonium onto wheat straw to be reused as a slow-release fertilizer.

    Science.gov (United States)

    Xie, Lihua; Lü, Shaoyu; Liu, Mingzhu; Gao, Chunmei; Wang, Xinggang; Wu, Lan

    2013-04-10

    With the aim of improving fertilizer use efficiency and minimizing the negative impact of nitrogen pollution, a new multifunctional slow-release fertilizer was prepared by recovery of ammonium from aqueous solutions onto a superabsorbent composite. An eco-friendly superabsorbent composite based on wheat straw (WS) was synthesized and used as the carrier to control the release of nutrients. The adsorption studies with NH₄⁺ indicated that the superabsorbent composite showed good affinity for NH₄⁺, with an adsorption capacity of 7.15 mmol g⁻¹ when 20 wt % of WS was incorporated and that the adsorption system can reach equilibrium within 40 min. Afterward, the feasibility of reusing the composite as a multifunctional slow-release nitrogen fertilizer was investigated. The results showed that the product with good water-retention and slow-release capacities could regulate soil acidity and was economical and eco-friendly for application in agriculture and horticulture. PMID:23495955

  6. Recovery of ammonium onto wheat straw to be reused as a slow-release fertilizer.

    Science.gov (United States)

    Xie, Lihua; Lü, Shaoyu; Liu, Mingzhu; Gao, Chunmei; Wang, Xinggang; Wu, Lan

    2013-04-10

    With the aim of improving fertilizer use efficiency and minimizing the negative impact of nitrogen pollution, a new multifunctional slow-release fertilizer was prepared by recovery of ammonium from aqueous solutions onto a superabsorbent composite. An eco-friendly superabsorbent composite based on wheat straw (WS) was synthesized and used as the carrier to control the release of nutrients. The adsorption studies with NH₄⁺ indicated that the superabsorbent composite showed good affinity for NH₄⁺, with an adsorption capacity of 7.15 mmol g⁻¹ when 20 wt % of WS was incorporated and that the adsorption system can reach equilibrium within 40 min. Afterward, the feasibility of reusing the composite as a multifunctional slow-release nitrogen fertilizer was investigated. The results showed that the product with good water-retention and slow-release capacities could regulate soil acidity and was economical and eco-friendly for application in agriculture and horticulture.

  7. In Vitro and In Vivo toxicity profiling of ammonium-based deep eutectic solvents.

    Science.gov (United States)

    Hayyan, Maan; Looi, Chung Yeng; Hayyan, Adeeb; Wong, Won Fen; Hashim, Mohd Ali

    2015-01-01

    The cytotoxic potential of ammonium-based deep eutectic solvents (DESs) with four hydrogen bond donors, namely glycerine (Gl), ethylene glycol (EG), triethylene glycol (TEG) and urea (U) were investigated. The toxicity of DESs was examined using In Vitro cell lines and In Vivo animal model. IC50 and selectivity index were determined for the DESs, their individual components and their combinations as aqueous solutions for comparison purposes. The cytotoxicity effect of DESs varied depending on cell lines. The IC50 for the GlDES, EGDES, UDES and TEGDES followed the sequence of TEGDESIn Vivo toxicity profiles of DESs were being demonstrated, raising the toxicity issue of these neoteric mixtures and their potential applicability to be used for therapeutic purposes.

  8. Perfluorinated quaternary ammonium salts of polyoxometalate anions: Fluorous biphasic oxidation catalysis with and without fluorous solvents

    Energy Technology Data Exchange (ETDEWEB)

    Maayan, Galia; Fish, Richard H.; Neumann, Ronny

    2003-05-28

    Perfluorinated quaternary ammonium cations, [CF{sub 3}(CF{sub 2}){sub 7}(CH{sub 2}){sub 3}]{sub 3}CH{sub 3}N{sup +} (RFN{sup +}), were synthesized and used as counter cations for the [WZnM{sub 2}(H{sub 2}O){sub 2}(ZnW{sub 9}O{sub 34}){sub 2}]{sup 12-} (M = Mn(II), Zn(II)), polyoxometalate. The (RFN{sup +}){sub 12}[WZnM{sub 2}(H{sub 2}O){sub 2}(ZnW9O{sub 34}){sub 2}] compounds were fluorous biphasic catalysts for alcohol and alkenol oxidation, and alkene epoxidation with aqueous hydrogen peroxide. Reaction protocols with or without a fluorous solvent were tested. The catalytic activity and selectivity was affected both by the hydrophobicity of the solvent and the substrate.

  9. Influence of the Different Level Ammonium on NRA and GSA in Sugar Beet(Vulgaris L.)

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Ammonium nitrogen inhibited NR activity in sugar beet,NR activity was lower in endogenous substrate after ammonium nitrogen was used,and the correlation between NR activity and ammonium nitrogen levels was negative.But NR activity raised with the ammonium nitrogen levels raising in exogenous.Ammonium nitrogen prompted GS activity:the correlation between GS activity and ammonium nitrogen was positive,GS activity raised with ammonium nitrogen levels raising,GS activity of roots and leaves had same change trend in sugar beet in the whole growth duration after ammonium nitrogen was used,but GS activity in roots was higher than that in leaves.

  10. Formation of La{sup 3+}, Pr{sup 3+}, Eu{sup 3+}, Er{sup 3+}, and Lu{sup 3+} complexes with chloride ions, in aqueous medium; Formacion de complejos de La{sup 3+}, Pr{sup 3+}, Eu{sup 3+}, Er{sup 3+} y Lu{sup 3+} con iones cloruro, en medio acuoso

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez R, E.; Jimenez R, M.; Solache R, M. [ININ, 52750 La Marquesa, Estado de Mexico (Mexico)

    2007-07-01

    The constants of stability of the complexes of La{sup 3+}, Pr{sup 3+}, Eu{sup 3+}, Er{sup 3+}, and Lu{sup 3+} with Cl{sup -} ions, its were determined, in the aqueous medium of HCI - HClO{sub 4} and by a solvent extraction method. The dinonyl naphtalene sulfonic acid in n-heptane was used as extractant. The lanthanides concentration, it was measured by a VIS spectrophotometry method and by another radiochemical. The ions specific interaction theory (SIT) it was used for the extrapolation to ionic force 0 M. The results indicate that the stability constants of the LnCI{sup 2+} species diminishes when increasing the ion force and the charge density. (Author)

  11. Effect of Ammonium Nitrate on Nanoparticle Size Reduction

    Directory of Open Access Journals (Sweden)

    Kalyana C. Pingali

    2008-01-01

    Full Text Available Ammonium nitrate was added to the spraying solution as a foaming agent to reduce the particle size of nanoparticles synthesized in the spray-pyrolysis process. Ammonium nitrate was effective in breaking the aerosol droplet size and generating nanoparticles that were of approximately one order-of-magnitude (from 200 to 20 nm smaller diameter than those created in the absence of ammonium nitrate in the feed solution. This technique makes it possible to control the particle diameter of metallic nanoparticles below 20 nm.

  12. Simple chloride sensors for continuous groundwater monitoring

    DEFF Research Database (Denmark)

    Thorn, Paul; Mortensen, John

    2012-01-01

    The development of chloride sensors which can be used for continuous, on-line monitoring of groundwater could be very valuable in the management of our coastal water resources. However, sensor stability, drift, and durability all need to be addressed in order for the sensors to be used...... in continuous application. This study looks at the development of a simple, inexpensive chloride electrode, and evaluates its performance under continuous use, both in the laboratory and in a field test in a monitoring well. The results from the study showed a consistent response to changing chloride...... sensor remained responsive even at low chloride concentrations, where the conductivity electrode was no longer responding to changing chloride levels. With the results, it is believed that the simple chloride sensor could be used for continuous monitoring of groundwater quality....

  13. 高效液相色谱-串联质谱法测定樱桃番茄中四种季铵类农药%Simultaneous determination of quaternary ammonium compounds in tomato by liquid chromatography-tandem mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    张曦; 金芬; 钱永忠; 于志勇; 王静

    2011-01-01

    A method for the simultaneously determination of four representative quaternary ammonium compounds [ chlormequat (CQ) chloride, mepiquat(MQ) chloride, deiquat (DQ) dibromide hydrate and difenzoquat (DF) methyl sulfate] ,using liquid chromatography-tandem mass spectrometry(LC-MS/MS) system was developed. The chromatographic separation was performed using a hydrophilic interaction liquid chromatography(HILIC) column to avoid LC-MS system contamination with the use of ion-pair reagents. Aqueous solution containing 0.1 % formic acid (A) and acetonitrile(B) ( 75:25, V/V) were used as the mobile phasegavegood chromatographic retention and sensitivity for these four quaternary ammonium compounds(QACs).The recovery was 91.4%~106.3% for the four QACs at three concentration levels. The limit of quantitation (LOQ)for the four QACs in tomato samples were 0.005mg/kg based on the lowest spiked concentration with suitable precision and accuracy. Finally, the method was successfully used to detect residual QACs in cherry-tomatoes.%建立了4种季铵类农药(矮壮素、燕麦枯、敌草快和缩节胺)的高效液相色谱-串联质谱(LC-MS/MS)检测方法.样品用75%乙腈-水溶液提取,高速离心后取上清液过尼龙滤膜,用亲水柱分离,以含0.1%甲酸的水:乙腈=25:75(V:V)作为流动相,在正离子多反应监测(MRM)模式下进行测定.4种季铵类农药的线性范围为0.5~100ng/mL,线性相关系数在0.9982~0.9996范围内,方法检出限为0.005mg/kg,可以满足国际限量的要求.在0.04、0.08、0.16mg/kg添加浓度下,4种季铵类农药的回收率为91.4%~106.3%,相对标准偏差(RSD)小于15%.本方法可用于樱桃番茄样品中4种季铵类农药的测定.

  14. ENVIRONMENTAL EXPOSURE TO VINYL CHLORIDE

    Directory of Open Access Journals (Sweden)

    Henryka Langauer-Lewowicka

    2010-09-01

    Full Text Available Vinyl chloride (VC monomer is a wellknown carcinogenic and mutagenic substance causes liver damages, angiosarcoma of the liver, acro – osteolysis, sclerodermalike changes in workers chronically exposed to this gas. There are following VC emitors to the environment: VC production plants, polymerization facilities and planes where polyvinyl products are fabricated. Because of that, the general population is coming into VC contact through polluted air, food and water. VC concentration in all mentioned sites is very low, often not detectable. There was found any health risk for the general population. The VC air concentration in the vicinity to antropogenic emitors is always higher. Such a situation may causes undesirable health effect for residents living in the neighbourhood. Epidemiological studies are performed to detect the adverse VC effect in selected cohorts. Non of the study did not confirmed cases of angiosarcoma among residents living near a vinyl chloride sites. VC production is growing permanently, so VC emission will be higher. Because of that health monitoring of general population and especially of selected groups seems to be necessary in the future.

  15. Chemical equilibrium of hydrogen and aqueous solutions of 1 : 1 bicarbonate and formate salts with a common cation

    NARCIS (Netherlands)

    Engel, D.C.; Versteeg, G.F.; Swaaij, W.P.M. van

    1997-01-01

    The chemical equilibrium of hydrogen and aqueous solutions of 1:1 bicarbonate and formate salts with a common cation has been investigated in an intensively stirred batch reactor: MHCO3(aq) + H2(aq) ↔ MOOCH(aq) + H2O(l) This was accomplished for the sodium (M = Na), potassium (M = K) and ammonium (M

  16. Green process to recover magnesium chloride from residue solution of potassium chloride production plant

    Institute of Scientific and Technical Information of China (English)

    Lin WANG; Yunliang HE; Yanfei WANG; Ying BAO; Jingkang WANG

    2008-01-01

    The green process to recover magnesium chlor-ide from the residue solution of a potassium chloride pro-duction plant, which comes from the leach solution of a potash mine in Laos, is designed and optimized. The res-idue solution contains magnesium chloride above 25 wt-%, potassium chloride and sodium chloride together below 5 wt-% and a few other ions such as Br-, SO2-4and Ca2+. The recovery process contains two steps: the previous impurity removal operation and the two-stage evapora-tion-cooling crystallization procedure to produce magnes-ium chloride. The crystallized impurity carnallite obtained from the first step is recycled to the potassium chloride plant to recover the potassium salt. The developed process is a zero discharge one and thus fulfills the requirements for green chemical industrial production. The produced magnesium chloride is up to industrial criteria.

  17. {sup 14}N NQR and relaxation in ammonium nitrate

    Energy Technology Data Exchange (ETDEWEB)

    Stephenson, David, E-mail: david.stephenson@sta.uwi.edu [University of the West Indies, Chemistry Department (Trinidad and Tobago)

    2015-04-15

    The complete {sup 14}N nuclear quadrupole resonance (NQR) spectrum of ammonium nitrate is presented recorded using two double resonance techniques – double contact cross relaxation and zero field NQR. The spectra gave the quadrupole coupling constant (Qcc) and asymmetry parameter (η) values for the nitro of 611 kHz, 0.229 and that for the ammonium nitrogen of 242 kHz, 0.835. The three relaxation transition probabilities have been determined for both the nitro and ammonium nitrogen atoms. The bi-exponential relaxation times (T {sub 1}) were measured at 295 K. The values for nitro are 16.9 s and 10.5 s and that of the ammonium are 23.0 s and 16.4 s.

  18. Ammonium removal by modified zeolite from municipal wastewater

    Institute of Scientific and Technical Information of China (English)

    ZHAO Ya-ping; GAO Ting-yao; JIANG Shang-ying; CAO Da-wen

    2004-01-01

    Ammonium removal by modified zeolite, H-form and Na-form zeolite, were examined by batch-type methods. The adsorption of ammonium on modified zeolite was exothermic process. The saturation adsorption capacity of ammonium on H-form and Na-form zeolite were 21.23 and 41.15 mg/g, respectively. After ten times adsorption- desorption-readsorption cycles the standard deviations of H-form and Na-form zeolite were 6.34% and 6.59%. The zeolite adsorption process has proved cost effective and practical in reducing ammonium by H-form and Na-form zeolite in municipal wastewater from concentration 27.68 mg/L to 2.80 mg/L and 5.91 mg/L.

  19. Fixed Ammonium Content and Maximum Capacity of Ammonium Fixation in Major Types of Tillage Soils in Hunan Province, China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yang-zhu; HUANG Shun-hong; WAN Da-juan; HUANG Yun-xiang; ZHOU Wei-jun; ZOU Ying-bin

    2007-01-01

    In order to understand the status of fixed ammonium, fixed ammonium content, maximum capacity of ammonium fixation, and their influencing factors in major types of tillage soils of Hunan Province, China, were studied with sampling on fields, and laboratory incubation and determination. The main results are summarized as follows: (1) Content of fixed ammonium in the tested soils varies greatly with soil use pattern and the nature of parent material. For the paddy soils, it ranges from 135.4 ± 57.4 to 412.8±32.4 mg kg-1, with 304.7±96.7 mg kg-1 in average; while it ranges from 59.4 to 435.7 mg kg-1, with 230.1 ± 89.2 mg kg1 in average for the upland soils. The soils developed from limnic material and slate had higher fixed ammonium content than the soils developed from granite. The percentage of fixed ammonium to total N in the upland soils is always higher than that in the paddy soils. It ranges from 6.1 ± 3.6% to 16.6 ±4.6%, with 14.0% ± 5.1% in average for the paddy soils and it amounted to 5.8 ±2.0% to 40.1 ± 17.8%, with 23.5 ± 14.2% in average for upland soils. (2) The maximum capacity of ammonium fixation has the same trend with the fixed ammonium content in the tested soils. For all the tested soils, the percentage of recently fixed ammonium to maximum capacity of ammonium fixation is always bellow 20% and it may be due to the fact that the soils have high fertility and high saturation of ammonium-fixing site. (3) The clay content and clay composition in the tested soils are the two important factors influe ncing their fixed ammonium content and maximum capacity of ammonium fixation. The results showed that hydrous mica is the main 2:1 type clay mineral in <0.02 mm clay of the paddy soils, and its content in 0.02-0.002 mm clay is much higher than that in < 0.002 mm clay of the soils. The statistical analysis showed that both the fixed ammonium content and the maximum capacity of ammonium fixation of the paddy soils were positively correlated with

  20. Influence of Chloride-Ion Adsorption Agent on Chloride Ions in Concrete and Mortar

    OpenAIRE

    Gai-Fei Peng; Nai-Qian Feng; Qi-Ming Song

    2014-01-01

    The influence of a chloride-ion adsorption agent (Cl agent in short), composed of zeolite, calcium aluminate hydrate and calcium nitrite, on the ingress of chloride ions into concrete and mortar has been experimentally studied. The permeability of concrete was measured, and the chloride ion content in mortar was tested. The experimental results reveal that the Cl agent could adsorb chloride ions effectively, which had penetrated into concrete and mortar. When the Cl agent was used at a dosage...

  1. Factors influencing chloride deposition in a coastal hilly area and application to chloride deposition mapping

    OpenAIRE

    H. Guan; Love, A. J.; C. T. Simmons; Makhnin, O.; A. S. Kayaalp

    2010-01-01

    Chloride is commonly used as an environmental tracer for studying water flow and solute transport in the environment. It is especially useful for estimating groundwater recharge based on the commonly used chloride mass balance (CMB) method. Strong spatial variability in chloride deposition in coastal areas is one difficulty encountered in appropriately applying the method. A high-resolution bulk chloride deposition map in the coastal region is thus needed. The aim of this study is to construc...

  2. Factors influencing chloride deposition in a coastal hilly area and application to chloride deposition mapping

    OpenAIRE

    H. Guan; Love, A. J.; C. T. Simmons; Makhnin, O.; A. S. Kayaalp

    2010-01-01

    Chloride is commonly used as an environmental tracer for studying water flow and solute transport in the environment. It is especially useful for estimating groundwater recharge based on the commonly used chloride mass balance (CMB) method. Strong spatial variability in chloride deposition in coastal areas is one difficulty encountered in appropriately applying the method. A high-resolution bulk chloride deposition map in the coastal region is thus needed. The aim of this st...

  3. Ruthenium on chitosan: A recyclable heterogeneous catalyst for aqueous hydration of nitriles to amides

    Science.gov (United States)

    Ruthenium has been immobilized over chitosan by simply stirring an aqueous suspension of chitosan in water with ruthenium chloride and has been utilized for the oxidation of nitriles to amides; the hydration of nitriles occurs in high yield and excellent selectivity, which procee...

  4. Preparation of CdTe nanocrystal-polymer composite microspheres in aqueous solution by dispersing method

    Institute of Scientific and Technical Information of China (English)

    LI Minjie; WANG Chunlei; HAN Kun; YANG Bai

    2005-01-01

    Highly fluorescent CdTe nanocrystals were synthesized in aqueous solution, and then processible CdTe nanocrystal-polymer composites were fabricated by coating the aqueous nanocrystals with copolymers of styrene and octadecyl-p-vinyl-benzyldimethylammonium chloride (SOV- DAC) directly. A dichloromethane solution of CdTe nano- crystal-polymer composites was dispersed in the aqueous solution of poly (vinyl alcohol) (PVA) generating highly fluorescent microspheres. Experimental parameters such as the concentration of nanocrystal-polymer composites, the concentration of PVA, and stirring speed which had important effect on the preparation of the microspheres were investigated in detail with fluorescent microscope characterization.

  5. Effects of pH and chloride concentration on pitting corrosion of AA6061 aluminum alloy

    Energy Technology Data Exchange (ETDEWEB)

    Zaid, B. [Division de Technologie du Combustible, Departement de Metallurgie, Centre de Recherche Nucleaire de Draria, BP. 43 Seballa, Draria (Algeria)], E-mail: zaidbachir@yahoo.com; Saidi, D. [Division de Technologie du Combustible, Departement de Metallurgie, Centre de Recherche Nucleaire de Draria, BP. 43 Seballa, Draria (Algeria); Benzaid, A. [Divisionde Physique et Application Nucleaires, Departement Application Nucleaires, Centre de Recherche Nucleaire de Draria, BP. 43 Seballa, Draria (Algeria); Hadji, S. [Division de Technologie du Combustible, Departement du combustible, Centre de Recherche Nucleaire de Draria, BP. 43 Seballa, Draria (Algeria)

    2008-07-15

    Effects of pH solution and chloride (Cl{sup -}) ion concentration on the corrosion behaviour of alloy AA6061 immersed in aqueous solutions of NaCl have been investigated using measurements of weight loss, potentiodynamic polarisation, linear polarisation, cyclic polarisation experiment combined with open circuit potential transient technique and optical or scanning electron microscopy. The corrosion behaviour of the AA6061 aluminum alloy was found to be dependant on the pH and chloride concentration [NaCl] of solution. In acidic or slightly neutral solutions, general and pitting corrosion occurred simultaneously. In contrast, exposure to alkaline solutions results in general corrosion. Experience revealed that the alloy AA6061 was susceptible to pitting corrosion in all chloride solution of concentration ranging between 0.003 wt% and 5.5 wt% NaCl and an increase in the chloride concentration slightly shifted both the pitting E{sub pit} and corrosion E{sub cor} potentials to more active values. In function of the conditions of treatment, the sheets of the alloy AA6061 undergo two types of localised corrosion process, leading to the formation of hemispherical and crystallographic pits. Polarisation resistance measurements in acidic (pH = 2) and alkaline chloride solutions (pH = 12) which are in good agreement with those of weight loss, show that the corrosion kinetic is minimised in slightly neutral solutions (pH = 6)

  6. The Effect of Chloride Ions on the Activity of Cerussite Surfaces

    Directory of Open Access Journals (Sweden)

    Qicheng Feng

    2016-09-01

    Full Text Available Chloride ions were found to potentially increase activity of cerussite surfaces. Dissolution experiments, zeta potential measurements, X-ray photoelectron spectroscopy (XPS studies, and density functional theory (DFT computation were conducted in this study. Dissolution experiments showed that the lead ion concentrations in the NaCl solution system were lower than those in the deionized water system and that the lead ion concentrations in NaCl + Na2S aqueous systems decreased by approximately one order of magnitude compared with that in the Na2S system alone. Results of zeta potential measurements revealed that the pretreatment with chloride ions of cerussite caused a more positive zeta potential than that without chloride ions. XPS analysis results indicated that the number of lead ions on the mineral surface increased after cerussite was treated with chloride ions. Results of DFT computation implied that the number of lead atoms on the mineral surface increased and that the activity improved after PbCl+ was adsorbed onto the cerussite surface. The contribution of chloride ions to the activity on the mineral surface is attributed to the increase in the number of active sites and enhancement in the activity of these sites, resulting in improved sulfidization and flotation performance.

  7. Mutagenicity of quaternary ammonium salts containing carbohydrate moieties

    Energy Technology Data Exchange (ETDEWEB)

    Dmochowska, Barbara [Department of Carbohydrate Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Piosik, Jacek; Woziwodzka, Anna [Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Kladki 24, 80-822 Gdansk (Poland); Sikora, Karol; Wisniewski, Andrzej [Department of Carbohydrate Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Wegrzyn, Grzegorz, E-mail: wegrzyn@biotech.univ.gda.pl [Department of Molecular Biology, University of Gdansk, Kladki 24, 80-822 Gdansk (Poland)

    2011-10-15

    Highlights: {yields} A series of quaternary ammonium salts containing carbohydrate moieties, with configuration D-galacto, D-gluco and D-manno, was synthesized and characterized. {yields} The quaternary ammonium salts containing carbohydrate moieties revealed potent mutagenic activities, as assessed by using the Vibrio harveyi bioluminescence mutagenicity test. {yields} The N-[2-(D-glycopyranosyloxy)ethyl]-N,N,N-trimethylaminium salts were of the highest activity in the mutagenicity assay. {yields} We suggest that quaternary ammonium salts may be more hazardous than previously supposed. - Abstract: Quaternary ammonium salts are widely used in industrial, agricultural, healthcare and domestic applications. They are believed to be safe compounds, with little or no health hazard to humans. However, in this report, we demonstrate that a series of newly synthesized quaternary ammonium salts containing carbohydrate moieties reveal potent mutagenic activities, as assessed by using the Vibrio harveyi bioluminescence mutagenicity test. D-Gluco- and D-galacto-derivatives were found to have a higher mutagenic potential than D-manno-derivatives. Among the former groups of compounds, the N-[2-(D-glycopyranosyloxy)ethyl]-N,N,N-trimethylaminium salts were of the highest activity in the mutagenicity assay. These results suggest that the safety of quaternary ammonium salts may be lower than previously supposed, indicating a need for testing such compounds for their mutagenicity.

  8. Leaching of complex sulphide concentrate in acidic cupric chloride solutions

    Institute of Scientific and Technical Information of China (English)

    M. TCHOUMOU; M. ROYNETTE

    2007-01-01

    The chemical analysis of a complex sulphide concentrate by emission spectrometry and X-ray diffraction shows that it contains essentially copper, lead, zinc and iron in the form of chalcopyrite, sphalerite and galena. A small amount of pyrite is also present in the ore but does not be detected with X-ray diffraction. The cupric chloride leaching of the sulphide concentrate at various durations and solid/liquid ratios at 100 ℃ shows that the rate of dissolution of the ore is the fastest in the first several hours, and after 12 h it does not evolve significantly. If oxygen is excluded from the aqueous cupric chloride solution during the leaching experiment at 100 ℃, the pyrite in the ore will not be leached. The determination of principal dissolved metals in the leaching liquor by flame atomic absorption spectrometry, and the chemical analysis of solid residues by emission spectrometry and X-ray diffraction allow to conclude that the rate of dissolution of the minerals contained in the complex sulphide concentrate are in the order of galena>sphalerite>chalcopyrite.

  9. Detecting Airborne Mercury by Use of Palladium Chloride

    Science.gov (United States)

    Ryan, Margaret; Shevade, Abhijit; Kisor, Adam; Homer, Margie; Jewell, April; Manatt, Kenneth; Torres, Julia; Soler, Jessica; Taylor, Charles

    2009-01-01

    Palladium chloride films have been found to be useful as alternatives to the gold films heretofore used to detect airborne elemental mercury at concentrations of the order of parts per billion (ppb). Somewhat more specifically, when suitably prepared palladium chloride films are exposed to parts-per-billion or larger concentrations of airborne mercury, their electrical resistances change by amounts large enough to be easily measurable. Because airborne mercury adversely affects health, it is desirable to be able to detect it with high sensitivity, especially in enclosed environments in which there is a risk of leakage of mercury from lamps or other equipment. The detection of mercury by use of gold films involves the formation of gold/mercury amalgam. Gold films offer adequate sensitivity for detection of airborne mercury and could easily be integrated into an electronic-nose system designed to operate in the temperature range of 23 to 28 C. Unfortunately, in order to regenerate a gold-film mercury sensor, one must heat it to a temperature of 200 C for several minutes in clean flowing air. In preparation for an experiment to demonstrate the present sensor concept, palladium chloride was deposited from an aqueous solution onto sets of gold electrodes and sintered in air to form a film. Then while using the gold electrodes to measure the electrical resistance of the films, the films were exposed, at a temperature of 25 C, to humidified air containing mercury at various concentrations from 0 to 35 ppb (see figure). The results of this and other experiments have been interpreted as signifying that sensors of this type can detect mercury in room-temperature air at concentrations of at least 2.5 ppb and can readily be regenerated at temperatures <40 C.

  10. New synthetic method and properties of ammonium dinitramide; Ammonium dinitramide no shingoseiho to sono butsuri kagakuteki tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Hatano, H.; Onda, T.; Shiino, K. [Hosoya Kako Co. Ltd., Tokyo (Japan). Technology and Development Center; Miyazaki, S.; Matsuura, S. [Nissan Motor Co. Ltd., Saitama (Japan). Research and Development center

    1996-08-31

    Though, ammonium nitrate (AN) has been thought as solid propellant oxidizer, at present, ammonium perchlorate (AP) is mainly used because of the existence of crystal transition point, the improvement of propellant performance on AN and so forth. Ammonium dinitramide (ADN) can be used as an excellent oxidizer for high performance solid propellants, because it has much available oxygen. Furthermore, this propellant is smokeless, since ADN has no halogen resulting in generation of smoke on burning. ADN can be obtained by a new synthetic method which uses urea as starting substance and acquires nitrourea as intermediate product. According to this method, the yield is about 15% based on the amount of nitrourea. The hygroscopicity of this ADN is slightly higher than that of ammonium nitrate. Therefore, it is recommended to handle this substance at 50% of relative humidity or below. 13 refs., 7 figs., 4 tabs.

  11. Chloride ingress in cement paste and mortar

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede; Hansen, Per Freiesleben; Coats, Alison M.;

    1999-01-01

    modelled on Fick's law modified by a term for chloride binding. Inclusion of chloride binding significantly improves the profile shape of the modelled ingress profiles. The presence of fine aggregate and formation of interfacial transition zones at paste-aggregate boundaries does not significantly affect...

  12. Chloride ingress in cement paste and mortar

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede; Hansen, Per Freiesleben; Coats, Alison M.;

    1999-01-01

    In this paper chloride ingress in cement paste and mortar is followed by electron probe microanalysis. The influence of several paste and exposure parameters on chloride ingress are examined (e.g., water-cement ratio, silica fume addition, exposure time, and temperature), The measurements...

  13. 75 FR 19657 - Barium Chloride From China

    Science.gov (United States)

    2010-04-15

    ... Commission found that the domestic interested party group response to its notice of institution (74 FR 31757... COMMISSION Barium Chloride From China AGENCY: United States International Trade Commission. ACTION: Notice of... chloride from China. SUMMARY: The Commission hereby gives notice that it will proceed with a full...

  14. Chloride binding site of neurotransmitter sodium symporters

    DEFF Research Database (Denmark)

    Kantcheva, Adriana Krassimirova; Quick, Matthias; Shi, Lei;

    2013-01-01

    Neurotransmitter:sodium symporters (NSSs) play a critical role in signaling by reuptake of neurotransmitters. Eukaryotic NSSs are chloride-dependent, whereas prokaryotic NSS homologs like LeuT are chloride-independent but contain an acidic residue (Glu290 in LeuT) at a site where eukaryotic NSSs...

  15. Chronopotentiometric chloride sensing using transition time measurement

    NARCIS (Netherlands)

    Abbas, Y.; Graaf, de D.B.; Olthuis, W.; Berg, van den A.

    2013-01-01

    Detection of chloride ions is crucial to accurately access the concrete structure durability[1]. The existing electrochemical method of chloride ions detection in concrete, potentiometry[1], is not suitable for in-situ measurement due to the long term stability issue of conventional reference electr

  16. Chemische contaminanten in diervoeder additief Choline Chloride

    NARCIS (Netherlands)

    Traag, W.A.; Hoogenboom, L.A.P.; Jong, de J.; Egmond, van H.J.; Dam, ten G.

    2010-01-01

    Dit briefrapport beschrijft de resultaten van een onderzoek naar chemische contaminanten in Choline Chloride. De doelstellingen waren: 1) Inzicht te verkrijgen in het voorkomen van (gebromeerde) vlamvertragers en broomdioxines in het diervoederadditief Choline Chloride en het, op basis van de result

  17. Aqueous greenhouse species in clouds, fogs, and aerosols

    International Nuclear Information System (INIS)

    Greenhouse effects from fossil fuel combustion leading to increased concentrations of primary and secondary greenhouse gases (e.g., CO-2, ozone, etc.) have received considerable attention. More recently, it has been suggested that clouds, aerosols, and fogs can play opposing roles in climate forcing by scattering or absorbing incoming solar radiation as well as by absorbing long-wave radiation as it escapes into space. The total effect on the radiation balance depends on the relative magnitude of these opposing forces, which in turn will depend on the composition of the aqueous phase. This work describes the measurement of water-soluble infrared absorbers which can contribute to the long-wave radiative forcing of clouds, fogs, and aerosols. Aqueous species which have been characterized include sulfate, nitrate, formate, acetate, oxalate, phenol, p-nitrophenol, ammonium, bicarbonate, formaldehyde, methanol, and ethanol. Infrared absorption band positions and band strengths have been determined, and their relative effects on radiative forcing are discussed

  18. Methods to Stabilize and Destabilize Ammonium Borohydride

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Thomas K.; Karkamkar, Abhijeet J.; Bowden, Mark E.; Besenbacher, Fleming; Jensen, Torben R.; Autrey, Thomas

    2013-01-21

    Ammonium borohydride, NH4BH4, has a high hydrogen content of ρm = 24.5 wt% H2 and releases 18 wt% H2 below T = 160 °C. However, the half-life of bulk NH4BH4 at ambient temperatures, ~6 h, is insufficient for practical applications. The decomposition of NH4BH4 (ABH2) was studied at variable hydrogen and argon back pressures to investigate possible pressure mediated stabilization effects. The hydrogen release rate from solid ABH2 at ambient temperatures is reduced by ~16 % upon increasing the hydrogen back pressure from 5 to 54 bar. Similar results were obtained using argon pressure and the observed stabilization may be explained by a positive volume of activation in the transition state leading to hydrogen release. Nanoconfinement in mesoporous silica, MCM-41, was investigated as alternative means to stabilize NH4BH4. However, other factors appear to significantly destabilize NH4BH4 and it rapidly decomposes at ambient temperatures into [(NH3)2BH2][BH4] (DADB) in accordance with the bulk reaction scheme. The hydrogen desorption kinetics from nanoconfined [(NH3)2BH2][BH4] is moderately enhanced as evidenced by a reduction in the DSC decomposition peak temperature of ΔT = -13 °C as compared to the bulk material. Finally, we note a surprising result, storage of DADB at temperature < -30 °C transformed, reversibly, the [(NH3)2BH2][BH4] into a new low temperature polymorph as revealed by both XRD and solid state MAS 11B MAS NMR. TA & AK are thankful for support from the US Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences. A portion of the research was performed using EMSL, a national scientific user facility sponsored by the Department of Energy's Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory (PNNL). PNNL is operated by Battelle.

  19. From greenhouse gas to feedstock: formation of ammonium carbamate from CO{sub 2} and NH{sub 3} in organic solvents and its catalytic conversion into urea under mild conditions

    Energy Technology Data Exchange (ETDEWEB)

    Barzagli, F.; Mani, F.; Peruzzini, M. [University of Florence, Florence (Italy). Dept. of Chemistry

    2011-07-01

    The capture of carbon dioxide by ammonia in both aqueous and non-aqueous solutions was investigated at atmospheric pressure and 273 K under different operating conditions. The CO{sub 2} capture is fast and efficient ranging between 78 and 99%, depending on both the NH{sub 3} concentration and the solvent nature. The precipitation of solid mixtures of ammonium bicarbonate, ammonium carbonate and ammonium carbamate occurred in ethanol-water solution. Selective precipitation of ammonium carbamate was achieved by reacting gaseous CO{sub 2} and NH{sub 3} in anhydrous ethanol, 1-propanol or N,N-dimethylformamide (DMF) in a flow reactor that operates in continuous. In the second step of the process, the pure ammonium carbamate is used to produce urea with good yield (up to 54% on carbamate basis) at 393-413 K in the presence of inexpensive Cu(II) and Zn(II) catalysts. The yield of urea depends on several factors including the catalyst, the reaction temperature and the reaction time. Identification and quantification of urea in the reaction mixtures was obtained by analysis of its {sup 13}C NMR spectrum. A preliminary mechanistic interpretation of the catalytic reaction is also briefly presented and commented.

  20. 76 FR 49449 - Continuation of Antidumping Duty Order on Solid Fertilizer Grade Ammonium Nitrate From the...

    Science.gov (United States)

    2011-08-10

    ... International Trade Administration Continuation of Antidumping Duty Order on Solid Fertilizer Grade Ammonium... duty investigation on solid fertilizer grade ammonium nitrate (``ammonium nitrate'') from the Russian... Initiation of Five-Year (``Sunset'') Review, 76 FR 11202 (March 1, 2011) and Ammonium Nitrate from...

  1. A novel hydrolysis method to synthesize chromium hydroxide nanoparticles and its catalytic effect in the thermal decomposition of ammonium perchlorate

    International Nuclear Information System (INIS)

    Highlights: ► Synthesis of Cr(OH)3 nanoparticles in Cr3+–F− aqueous solution. ► The F− ion tailors coagulated materials, Cr(OH)3 nanoparticles are obtained. ► Adding nanosized Cr(OH)3, AP thermal decomposition temperature decreases to 200 °C. ► The nanosized Cr(OH)3 catalyzes NH3 oxidation, accelerating AP thermal decomposition. - Abstract: A procedure for the preparation of spherical Cr(OH)3 nanoparticles was developed based on the aging of chromium nitrate aqueous solutions in the presence of sodium fluoride, urea, and polyvinylpyrrolidone. Using scanning electron microscopy, transmission electron microscopy, and energy dispersive spectroscopy, the morphological characteristics of Cr(OH)3 were controlled by altering the molar ratio of fluoride ion to chromium ion, as well as the initial pH and chromium ion concentration. The prepared nanosized Cr(OH)3 decreased the temperature required to decompose ammonium perchlorate from 450 °C to about 250 °C as the catalyst. The possible catalytic mechanism of the thermal decomposition of ammonium perchlorate was also discussed.

  2. CHARACTERISTICS OF QUATERNARY AMMONIUM RESISTANT BACTERIA FROM A FINE PAPERMACHINE SYS-TEM

    Institute of Scientific and Technical Information of China (English)

    HweigWang; ChiYuHuang; ChunHanKo

    2004-01-01

    To evaluate the biocide effect of quaternary ammonium chloride (QAC), a whitewater sample wastaken from a fine papermachine headbox. By platespreading method, 51 strains of facultative anaerobewere isolated morphologically. Then the strains wereseparately transferred to basal medium and were incubated before the beginning of log phase. To identify strains with different QAC resistance, 30-120 ppmof N-Alkyl-benzyl-dimethyl ammonium chloridewere added to basal medium.Biocide effect was investigated by comparison of bacterial growth, whichcan be monitored by 600 nm light absorbance ofbasal medium suspension. Among 51 strains, only 2strains can Survive for QAC concentration up to 120ppm. API20E aud 16S rRNA gene sequencing technique were applied to identify two strains with highest (120 ppm)QAC resistance. One strain (HB22)was identified as Morganella morganii. HB22 can resist QAC concentration up to 150 ppm. HB22 isGram-negative rod, motile with flagella, catalasepositive, oxidase negative, Indole positive, H2S production negative, facultative anaerobe. HB22 has op-timum growth condition of 35C and pH 7.0.HB22can catabolize only glucose and D (+)-Mannose.The other (HB45) was identified with high similarityamong Pseudomonas cf. monteili or Pseudomonas mosselii or Pseudomonas putida. HB45can resist QAC concentration up to 200 ppm.HB45 is Gram-negative rod, motile with flagella,catalase positive, oxidase negative, Indole negative,H2S production negative, aerobe. HB45 has optimum growth condition of 30~C and pH 7.4. HB45can catabolize L-Arabinose, L (+)-Rhanmose, D(+)-Mannose, Glucose, Glycerol, Lactose, Maltose,Raffmose, Xylose, Cellulose and Xylan. The implication of this work to paper industry is also discussed.

  3. Use of modifiers for the elimination in situ of chlorides, in the analysis by use of Total Reflection X-Ray Fluorescence

    International Nuclear Information System (INIS)

    Full text: The samples with high content of chlorides form deposits of salts on the reflector used for the analysis TXRF, affecting the quality of the thin film required for the analysis, producing an increase of the bed (bottom) and consequently an increase of the detection limit. Joined this, the levels of chlorine present in this type of samples, imply the presence of a peak K alpha of high-intensity, and as a consequence, the spectral interference with the neighboring peaks (lines of potassium K alpha, calcium and L of cadmium and silver, for example). By means of this work it is intended the use of chemical modifiers added in situ, on the sample, in the reflector, which allow the the elimination of chlorides and other salts formed on the reflector. For that reason three modifiers were proved: Ammonium nitrate, ammonium oxalate and oxalic acid in solutions of 10000 ppm. These compounds are added in excess, in a proportion of 50 microliters on an 10 microliters deposit of a pattern sample, with 1% of sodium chloride. The decrease of the the intensity of the pick K alpha of Cl with each one of the modifiers in function of the method of addition of modifier on the sample holders, heating mode and drying of the sample, temperature and drying time. For each case the limits of detection of the elements Ca, K, Se, Cd and Ni were determined. It was found that the more effective modifier is the ammonium nitrate more effective

  4. Effect of ammonium chloride and tunicamycin on the glycoprotein content and infectivity of herpes simplex virus type 1

    Energy Technology Data Exchange (ETDEWEB)

    Kousoulas, K.G.; Bzik, D.J.; DeLuca, N.; Person, S.

    1983-01-01

    Infectious virions of MP, a syncytial strain of herpes simplex virus type 1, are formed in the presence of 50 mM NH/sub 4/Cl. Underglycosylated virion glycoproteins are synthesized in infected cells and are incorporated into virions in the presence of the same concentration of NH/sub 4/Cl. We conclude that fully glycosylated glycoproteins are not required for viral infectivity. Virus particles, deficient in glycosylated glycoproteins, are assembled in the presence of tunicamycin but they are not infectious. The decrease in infectivity could be due to the decreased amount of the gB or possibly other peptides and/or to the lack of the high-mannose saccharides of precursor glycoproteins. 32 references, 4 figures.

  5. The effect of ammonium chloride and tunicamycin on the glycoprotein content and infectivity of herpes simplex virus type 1.

    Science.gov (United States)

    Kousoulas, K G; Bzik, D J; DeLuca, N; Person, S

    1983-03-01

    Infectious virions of MP, a syncytial strain of herpes simplex virus type 1, are formed in the presence of 50 mM NH4Cl. Underglycosylated virion glycoproteins are synthesized in infected cells and are incorporated into virions in the presence of the same concentration of NH4Cl. We conclude that fully glycosylated glycoproteins are not required for viral infectivity. Virus particles, deficient in glycosylated glycoproteins, are assembled in the presence of tunicamycin but they are not infectious. The decrease in infectivity could be due to the decreased amount of the gB or possibly other peptides and/or to the lack of the high-mannose saccharides of precursor glycoproteins. PMID:6301148

  6. Synthesis and characterisation of polyelectrolytes based on polymers of diallyldimethyl ammonium chloride and poly(styrene-co-butadiene)

    OpenAIRE

    Svensson, David

    2012-01-01

    In printed electronics there are many polyelectrolytes to choose from. While polyelectrolytes such as polystyrene sulfonic acid can fulfill many ofthe desired functionalities of a semiconductor, there is a need for other polyelectrolytes with other functionalities, such as functionality at low airhumidity and better cross-linking possibilities, while still functioning as a good semiconductor.Within this thesis, there is a description of general polyelectrolytes, as well as various usages.The ...

  7. Bone, blood and faecal response to an acidogenic lick for range cattle using different concentrations of ammonium chloride

    Directory of Open Access Journals (Sweden)

    D.E. Beighle

    2000-07-01

    Full Text Available Thirty Brahman-Angus cross heifers at breeding age on extensive grazing were used to test the effectiveness of NH4Cl as an acidogenic agent at 15, 18, 21 and 26 %of a dicalcium phosphate lick (A+, compared to a lick of 5 parts dicalcium phosphate and 3 parts salt (A-. Blood and faecal phosphorus (P, faecal calcium (Ca and faecal magnesium (Mg were significantly (P < 0.05 higher in A+ compared to A- animals at different stages of the experiment. Bone P did not increase in response to NH4Cl but bone Ca was significantly (P < 0.05 higher in A+animals offered 18 % NH4Cl and significantly (P < 0.05 lower at 15 and 26 %. Bone Mgin A+animals was significantly (P < 0.05 higher at 15 and 18 % NH4Cl and lower at 26 % NH4Cl compared to A- animals. Percentage ash in bone increased linearly from 62.5 to 64.9 % in A+ animals as NH4Cl was increased in the lick from 15 to 21 % and then decreased to 63.3 % but was significantly (P < 0.05 greater than the percentage ash in A- animals when the NH4Cl was increased to 26 %. Bone mineral status was only marginally improved by adding NH4Cl to the lick in this study but blood P was significantly (P < 0.05 improved in A+ compared to A- animals when the lick contained 15, 21 and 26 % NH4Cl. Based on bone mineral results reported here, it is recommended that, when NH4Cl is used as an acidogenic agent in licks for range cattle, the amount in the lick should not exceed 21 %.

  8. Chlorobenzene formation from fly ash: effect of moisture, chlorine gas, cupric chloride, urea, ammonia and ammonium sulfate

    NARCIS (Netherlands)

    M. Yan; Z.F. Qi; X.D. Li; T. Chen; S.Y. Lu; A.G. Buekens; K. Olie; J.H. Yan; K. Olie

    2012-01-01

    Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) are formed jointly with numerous products of incomplete combustion during waste incineration. Chlorobenzenes (CBz) are often cited as surrogates or precursors of PCDD/Fs. Experiments were conducted to investigate the effect of some key pa

  9. Effect of biochar amendment on sorption and leaching of nitrate, ammonium, and phosphate in a sandy soil.

    Science.gov (United States)

    Yao, Ying; Gao, Bin; Zhang, Ming; Inyang, Mandu; Zimmerman, Andrew R

    2012-11-01

    When applied to soils, it is unclear whether and how biochar can affect soil nutrients. This has implications both to the availability of nutrients to plants or microbes, as well as to the question of whether biochar soil amendment may enhance or reduce the leaching of nutrients. In this work, a range of laboratory experiments were conducted to determine the effect of biochar amendment on sorption and leaching of nitrate, ammonium, and phosphate in a sandy soil. A total of thirteen biochars were tested in laboratory sorption experiments and most of them showed little/no ability to sorb nitrate or phosphate. However, nine biochars could remove ammonium from aqueous solution. Biochars made from Brazilian pepperwood and peanut hull at 600°C (PH600 and BP600, respectively) were used in a column leaching experiment to assess their ability to hold nutrients in a sandy soil. The BP600 biochar effectively reduced the total amount of nitrate, ammonium, and phosphate in the leachates by 34.0%, 34.7%, and 20.6%, respectively, relative to the soil alone. The PH600 biochar also reduced the leaching of nitrate and ammonium by 34% and 14%, respectively, but caused additional phosphate release from the soil columns. These results indicate that the effect of biochar on the leaching of agricultural nutrients in soils is not uniform and varies by biochar and nutrient type. Therefore, the nutrient sorption characteristics of a biochar should be studied prior to its use in a particular soil amendment project. PMID:22763330

  10. Reversible Swelling of Chitosan and Quaternary Ammonium Modified Chitosan Brush Layers: Effect of pH and Counter Anion Size and Functionality

    OpenAIRE

    Lee, Hyun-Su; Yee, Michael Q.; Eckmann, Yonaton Y.; Hickok, Noreen J.; Eckmann, David M.; Composto, Russell J.

    2012-01-01

    This study investigates the swelling of grafted polycationic brushes as a function of pH and anion type. The brushes are chitosan (CH) and chitosans with 27% and 51% degree of substitution (DS) of quaternary ammonium salt, denoted as CH-Q25 and CH-Q50, respectively. The water content and swelling behaviors are monitored using in situ quartz-crystal microbalance with dissipation (QCM-D). The pH varies from ~3.5 to 8.5, and the counter anion types include chloride, acetate, and citrate. At fixe...

  11. Ethosomes for skin delivery of ammonium glycyrrhizinate: in vitro percutaneous permeation through human skin and in vivo anti-inflammatory activity on human volunteers.

    Science.gov (United States)

    Paolino, Donatella; Lucania, Giuseppe; Mardente, Domenico; Alhaique, Franco; Fresta, Massimo

    2005-08-18

    The aim of this work was the evaluation of various ethosomal suspensions made up of water, phospholipids and ethanol at various concentrations for their potential application in dermal administration of ammonium glycyrrhizinate, a useful drug for the treatment of various inflammatory-based skin diseases. Physicochemical characterization of ethosomes was carried out by photon correlation spectroscopy and freeze fracture electron microscopy. The percutaneous permeation of ammonium glycyrrhizinate/ethosomes was evaluated in vitro through human stratum corneum and epidermis membranes by using Franz's cells and compared with the permeation profiles of drug solutions either in water or in a water-ethanol mixture. Reflectance spectrophotometry was used as a non-invasive technique to evaluate the carrier toxicity, the drug permeation and the anti-inflammatory activity of ammonium glycyrrhizinate in a model of skin erythema in vivo on human volunteers. Ethosomal suspensions had mean sizes ranging from 350 nm to 100 nm as a function of ethanol and lecithin quantities, i.e., high amounts of ethanol and a low lecithin concentration provided ethosome suspensions with a mean size of approximately 100 nm and a narrow size distribution. In vitro and in vivo experiments were carried out by using an ethosome formulation made up of ethanol 45% (v/v) and lecithin 2% (w/v). The ethosome suspension showed a very good skin tolerability in human volunteers, also when applied for a long period (48 h). Ethosomes elicited an increase of the in vitro percutaneous permeation of both methylnicotinate and ammonium glycyrrhizinate. Ethosomes were able to significantly enhance the anti-inflammatory activity of ammonium glycyrrhizinate compared to the ethanolic or aqueous solutions of this drug. Some in vivo experiments also showed the ability of ethosome to ensure a skin accumulation and a sustained release of the ammonium glycyrrhizinate.

  12. Ethosomes for skin delivery of ammonium glycyrrhizinate: in vitro percutaneous permeation through human skin and in vivo anti-inflammatory activity on human volunteers.

    Science.gov (United States)

    Paolino, Donatella; Lucania, Giuseppe; Mardente, Domenico; Alhaique, Franco; Fresta, Massimo

    2005-08-18

    The aim of this work was the evaluation of various ethosomal suspensions made up of water, phospholipids and ethanol at various concentrations for their potential application in dermal administration of ammonium glycyrrhizinate, a useful drug for the treatment of various inflammatory-based skin diseases. Physicochemical characterization of ethosomes was carried out by photon correlation spectroscopy and freeze fracture electron microscopy. The percutaneous permeation of ammonium glycyrrhizinate/ethosomes was evaluated in vitro through human stratum corneum and epidermis membranes by using Franz's cells and compared with the permeation profiles of drug solutions either in water or in a water-ethanol mixture. Reflectance spectrophotometry was used as a non-invasive technique to evaluate the carrier toxicity, the drug permeation and the anti-inflammatory activity of ammonium glycyrrhizinate in a model of skin erythema in vivo on human volunteers. Ethosomal suspensions had mean sizes ranging from 350 nm to 100 nm as a function of ethanol and lecithin quantities, i.e., high amounts of ethanol and a low lecithin concentration provided ethosome suspensions with a mean size of approximately 100 nm and a narrow size distribution. In vitro and in vivo experiments were carried out by using an ethosome formulation made up of ethanol 45% (v/v) and lecithin 2% (w/v). The ethosome suspension showed a very good skin tolerability in human volunteers, also when applied for a long period (48 h). Ethosomes elicited an increase of the in vitro percutaneous permeation of both methylnicotinate and ammonium glycyrrhizinate. Ethosomes were able to significantly enhance the anti-inflammatory activity of ammonium glycyrrhizinate compared to the ethanolic or aqueous solutions of this drug. Some in vivo experiments also showed the ability of ethosome to ensure a skin accumulation and a sustained release of the ammonium glycyrrhizinate. PMID:15935505

  13. Polymer-clay nanocomposites obtained by solution polymerization of vinyl benzyl triammonium chloride in the presence of advanced functionalized clay

    Indian Academy of Sciences (India)

    Raluca Ianchis; Dan Donescu; Ludmila Otilia Cinteza; Violeta Purcar; Cristina Lavinia Nistor; Critian Petcu; Cristian Andi Nicolae; Raluca Gabor; Silviu Preda

    2014-05-01

    Polymer-clay nanocomposites were synthesized by solution polymerization method using advanced functionalized clay and vinyl benzyl trimethyl ammonium chloride as monomer. First stage consisted in the silylation of a commercial organo-modified clay-Cl 20A using alkoxysilanes with different chain lengths. In the second step, the synthesis and characterization of polymer-nanocomposites were followed. To evaluate the clay functionalization process as well as the final polymer-clay products, thermogravimetric,X-ray diffraction, dynamic light scattering, Fourier transform infrared spectroscopy and three test liquid contact angles analyses were used. The loss of ammonium ions from commercial clay, the grafting degree, the lengths and the nature of alkyl chain influence the dispersion of the advanced modified clay into the polymer solution and, furthermore, the properties of the final polymer-clay nanocomposite film.

  14. (Liquid + liquid) equilibrium data for the system (propylene glycol + water + tetraoctyl ammonium 2-methyl-1-naphthoate)

    International Nuclear Information System (INIS)

    Highlights: ► Recovery of PG from water using a task specific ionic liquid [TOA MNaph]. ► LLE data was correlated using the NRTL and UNIQUAC at three different temperatures. ► Both models describe the system adequately RSMD: 1.51% NRTL and 1.20% UNIQUAC. - Abstract: Propylene glycol (PG) is an important low toxic glycol, widely used in the food, cosmetics, pharmaceutical and the chemical industries. The recovery of PG from aqueous streams using conventional unit operations such as evaporation is highly energy demanding because of the large amounts of water that need to be evaporated. An alternative, more energy efficient technology could be liquid–liquid extraction. The use of tetraoctyl ammonium 2-methyl-1-naphtoate [TOA MNaph], a previously reported tailor made ionic liquid, (L.Y. Garcia-Chavez, B. Schuur, A.B. de Haan, J. Chem. Thermodyn. (2012). Doi: 10.1016/j.jct.2012.03.009) , for the extraction of mono ethylene glycol, was experimentally investigated for the liquid–liquid extraction of PG from aqueous streams by measuring the (liquid + liquid) equilibrium data for the system PG + water + [TOA MNaph] at three different temperatures. The data were correlated with both the NRTL and UNIQUAC models. Both thermodynamic models were able to correlate the experimental data well, with root square mean deviations (RMSD) of 1.51% and 1.20% for NRTL and UNIQUAC, respectively. From the high distribution of PG compared to traditional solvents, it could be concluded that [TOA MNaph] is a promising solvent for PG recovery from aqueous broths.

  15. Quaternary ammonium salt derivatives of allylphenols with peripheral analgesic effect

    Directory of Open Access Journals (Sweden)

    A. B de Oliveira

    1991-01-01

    Full Text Available Ammonium salt derivatives of natural allylphenols were synthesized with the purpose of obtaining potential peripheral analgesics. These drugs, by virtue of their physicochemical properties, would not be able to cross the blood brain barrier. Their inability to enter into the central nervous system (CNS should prevent several adverse effects observed with classical opiate analgesics (Ferreira et al., 1984. Eugenol (1 O-methyleugenol (5 and safrole (9 were submitted to nitration, reduction and permethylation, leading to the ammonium salts 4, 8 and 12. Another strategy applied to eugenol (1, consisting in its conversion to a glycidic ether (13, opening the epoxide ring with secondary amines and methylation, led to the ammonium salts 16 and 17. All these ammonium salts showed significant peripheral analgesic action, in modified version of the Randall-Sellito test (Ferreira et al. 1978, at non-lethal doses. The ammonium salt 8 showed an activity comparable to that of methylnalorphinium, the prototype of an ideal peripheral analgesic (Ferreira et al., 1984.

  16. Difficultly Extractable Fixed Ammonium in Some Soils of China

    Institute of Scientific and Technical Information of China (English)

    CHENBIYUN; CHENGLILI; 等

    1999-01-01

    Ninety-three soil samples and 19 sedimentary rock samples collected from 21 provinces of China were analyzed for their contents of fixed ammonium and total N by Kjeldahl-HF method.Results showed that amount of difficultly extractable fixed ammonium(the fixed ammonium that is not determinable by Kjeldahl procedures commonly used for soils) in soils ranged from 0 to 202 mg kg-1,It was generally more than 50 mg kg-1 in soils in Changji and Turpan districts,Xinjiang,accounting for 3.2%-36.8% with an average of 13.9% of the total N.For some Orthents derived from purple shale and purple sandstone in Sichuan and Hunan provinces and Chao soils derived from secondary loess in Henan Province and Ningxia Autonomous Region it was generally around 30 mg kg-1,accounting for 4%-7% of the total soil N,and for most of the rest of soils studied,with the exception of some subsoils,no or trace difficultly extractable fixed ammonium could be detected.It was sugested that the difficultly extractable fixed ammonium was originated from parent rock,and for slightly weathered soils derived from parent materials rich in this form of N the Kjeldahl method might give underestimation of total soil N.

  17. Chloride Transport in Undersea Concrete Tunnel

    Directory of Open Access Journals (Sweden)

    Yuanzhu Zhang

    2016-01-01

    Full Text Available Based on water penetration in unsaturated concrete of underwater tunnel, a diffusion-advection theoretical model of chloride in undersea concrete tunnel was proposed. The basic parameters including porosity, saturated hydraulic conductivity, chloride diffusion coefficient, initial water saturation, and moisture retention function of concrete specimens with two water-binder ratios were determined through lab-scale experiments. The variation of chloride concentration with pressuring time, location, solution concentration, initial saturation, hydraulic pressure, and water-binder ratio was investigated through chloride transport tests under external water pressure. In addition, the change and distribution of chloride concentration of isothermal horizontal flow were numerically analyzed using TOUGH2 software. The results show that chloride transport in unsaturated concrete under external water pressure is a combined effect of diffusion and advection instead of diffusion. Chloride concentration increased with increasing solution concentration for diffusion and increased with an increase in water pressure and a decrease in initial saturation for advection. The dominant driving force converted with time and saturation. When predicting the service life of undersea concrete tunnel, it is suggested that advection is taken into consideration; otherwise the durability tends to be unsafe.

  18. Shelf life of unrefrigerated succinylcholine chloride injection.

    Science.gov (United States)

    Boehm, J J; Dutton, D M; Poust, R I

    1984-02-01

    The shelf life of succinylcholine chloride injection at several pH values when stored at room temperature was evaluated. Solutions containing 20 mg/ml of succinylcholine chloride were stored at 25 and 40 degrees C. The reaction was studied at pH values ranging from 3.0 to 4.5. At two-week intervals, the solutions were assayed by high-pressure liquid chromatography. The initial amount of succinylcholine chloride in all samples was 100.1 +/- 2.37% of label claim. Hydrolysis of succinylcholine chloride in unbuffered solutions followed apparent zero-order kinetics. The pH range of maximum stability was found to be from 3.75 to 4.50. Succinylcholine chloride decomposed at a considerably higher rate at 40 degrees C. Allowing for the effects of pH adjustment during manufacture and degradation during shipping, losses of 7.0% and 9.0% potency can be expected after storage at 25 degrees C for four and six weeks, respectively. Succinylcholine Chloride Injection, USP, should be stored in the refrigerator; if unbuffered succinylcholine chloride injection complying with USP pH limits must be stored at room temperature, it should not be kept for longer than four weeks. PMID:6702837

  19. Factors influencing chloride deposition in a coastal hilly area and application to chloride deposition mapping

    Directory of Open Access Journals (Sweden)

    H. Guan

    2010-05-01

    Full Text Available Chloride is commonly used as an environmental tracer for studying water flow and solute transport in the environment. It is especially useful for estimating groundwater recharge based on the commonly used chloride mass balance (CMB method. Strong spatial variability in chloride deposition in coastal areas is one difficulty encountered in appropriately applying the method. A high-resolution bulk chloride deposition map in the coastal region is thus needed. The aim of this study is to construct a chloride deposition map in the Mount Lofty Ranges (MLR, a coastal hilly area of approximately 9000 km2 spatial extent in South Australia. We examined geographic (related to coastal distance, orographic, and atmospheric factors that may influence chloride deposition, using partial correlation and regression analyses. The results indicate that coastal distance, elevation, as well as terrain aspect and slope, appear to be significant factors controlling chloride deposition in the study area. Coastal distance accounts for 70% of spatial variability in bulk chloride deposition, with elevation, terrain aspect and slope an additional 15%. The results are incorporated into a de-trended residual kriging model (ASOADeK to produce a 1 km×1 km resolution bulk chloride deposition and concentration maps. The average uncertainty of the deposition map is about 20–30% in the western MLR, and 40–50% in the eastern MLR. The maps will form a useful basis for examining catchment chloride balance for the CMB application in the study area.

  20. Reliability-Based Planning of Chloride Measurements

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Engelund, S.

    1996-01-01

    on measurements of the chloride content obtained from the given structure. In the present paper optimal planning of measurements of the chloride content in reinforced concrete structures is considered. It is shown how optimal experimental plans can be obtained using FORM-analysis. Bayesian statistics are used......In reinforced concrete structures corrosion is initiated when the chloride concentration around the reinforcement exceeds a threshold value. If corrosion starts then expensive repairs can be necessary. The estimation of the probability that corrosion has been initiated in a given structure is based...