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Sample records for ammonium chloride monolithic

  1. 21 CFR 184.1138 - Ammonium chloride.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ammonium chloride. 184.1138 Section 184.1138 Food... Specific Substances Affirmed as GRAS § 184.1138 Ammonium chloride. (a) Ammonium chloride (NH4Cl, CAS Reg. No. 12125-02-9) is produced by the reaction of sodium chloride and an ammonium salt in solution....

  2. 21 CFR 172.165 - Quaternary ammonium chloride combination.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Quaternary ammonium chloride combination. 172.165... HUMAN CONSUMPTION Food Preservatives § 172.165 Quaternary ammonium chloride combination. The food additive, quaternary ammonium chloride combination, may be safely used in food in accordance with...

  3. Efficient cellulose solvent: quaternary ammonium chlorides.

    Science.gov (United States)

    Kostag, Marc; Liebert, Tim; El Seoud, Omar A; Heinze, Thomas

    2013-10-01

    Pure quaternary tetraalkylammonium chlorides with one long alkyl chain dissolved in various organic solvents constitute a new class of cellulose solvents. The electrolytes are prepared in high yields and purity by Menshutkin quaternization, an inexpensive and easy synthesis route. The pure molten tetraalkylammonium chlorides dissolve up to 15 wt% of cellulose. Cosolvents, including N,N-dimethylacetamide (DMA), may be added in large excess, leading to a system of decreased viscosity. Contrary to the well-established solvent DMA/LiCl, cellulose dissolves in DMA/quaternary ammonium chlorides without any pretreatment. Thus, the use of the new solvent avoids some disadvantages of DMA/LiCl and ionic liquids, the most extensively employed solvents for homogeneous cellulose chemistry.

  4. Unsteady growth of ammonium chloride dendrites

    Science.gov (United States)

    Martyushev, L. M.; Terentiev, P. S.; Soboleva, A. S.

    2016-02-01

    Growth of ammonium chloride dendrites from aqueous solution is experimentally investigated. The growth rate υ and the radius ρ of curvature of branches are measured as a function of the relative supersaturation Δ for steady and unsteady growth conditions. It is shown that the experimental results are quantitatively described by the dependences ρ=a/Δ+b, υ=cΔ2, where the factors for primary branches are a=(1.3±0.2)·10-7 m, b=(2.5±0.4)·10-7 m, and c=(2.2±0.3)·10-4 m/s. The factor c is found to be approximately 7 times smaller for the side branches than that for the primary branches.

  5. 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.

  6. 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.

  7. The nucleation kinetics of ammonium metavanadate precipitated by ammonium chloride

    Science.gov (United States)

    Du, Guangchao; Sun, Zhaohui; Xian, Yong; Jing, Han; Chen, Haijun; Yin, Danfeng

    2016-05-01

    The nucleation kinetics of ammonium metavanadate (NH4VO3) was investigated under conditions of the simulated process for precipitation of NH4VO3 from the vanadium-containing solution. Induction periods for the nucleation of NH4VO3 were experimentally determined as a function of supersaturation at temperatures from 30 to 45 °C. Using the classical nucleation theory, the interfacial tension between NH4VO3 and supersaturated solution, the nucleation rate and critical radius of nucleus for the homogeneous nucleation of NH4VO3 were estimated. With temperature increasing, the calculated interfacial tension gradually decreased from 29.78 mJ/m2 at 30 °C to 23.66 mJ/m2 at 45 °C. The nucleation rate was found to proportionally increase but the critical radius of nucleus exponentially decreased, with increase in supersaturation ratio at a constant temperature. The activation energy for NH4VO3 nucleation was obtained from the relationship between temperature and induction period, ranging from 79.17 kJ/mol at S=25 to 115.50 kJ/mol at S=15. FT-IR and Raman spectrum indicated that the crystals obtained in the precipitation process were NH4VO3.

  8. 21 CFR 520.310 - Caramiphen ethanedisulfonate and ammonium chloride tablets.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Caramiphen ethanedisulfonate and ammonium chloride... § 520.310 Caramiphen ethanedisulfonate and ammonium chloride tablets. (a) Specifications. Each tablet contains 10 milligrams of 5st caramiphen ethanedisulfonate and 80 milligrams of ammonium chloride.1 1...

  9. 40 CFR 415.240 - Applicability; description of the ammonium chloride production subcategory.

    Science.gov (United States)

    2010-07-01

    ... ammonium chloride production subcategory. 415.240 Section 415.240 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Ammonium Chloride Production Subcategory § 415.240 Applicability; description of the ammonium chloride production subcategory. The provisions of this subpart are applicable to...

  10. Hydrolysis of cupric chloride in aqueous ammoniacal ammonium chloride solutions

    Directory of Open Access Journals (Sweden)

    Limpo, J. L.

    1995-06-01

    Full Text Available Cupric solubility in the CuCl2-NH4Cl-NH3-H2O system for chloride concentrations lower than 4 molal in the temperature range 25-60 °C was studied. The experimental results show that for chloride concentration between 3.0 and 1.0 molal the cupric solubility is determined by the solubility of the cupric hydroxychloride Cu(OH1.5Cl0.5. For a chloride concentration value of 4.0 molal, there are two cupric compounds, the hydroxychloride Cu(OH1.5Cl0.5 or the diammine chloride Cu(NH32Cl2, on which the solubility of Cu(II depends, according to the temperature and the value of the ratio [NH3]Total/[Cu]Total.

    Se estudia la solubilidad del Cu(II en el sistema CuCl2-NH4Cl-NH3-H2O para concentraciones de cloruro inferiores a 4 molal en el intervalo de temperaturas 25-60 °C. Los resultados experimentales muestran que, para concentraciones de cloruros comprendidas entre 3,0 y 1,0 molal, la solubilidad cúprica viene determinada por la solubilidad del hidroxicloruro cúprico, Cu(OH1.5Cl0.5. Para concentraciones de cloruro 4,0 molal, existen dos compuestos cúpricos, el hidroxicloruro, Cu(OH1.5Cl0.5 o el cloruro de diamina, Cu(NH32Cl2, de los que, de acuerdo con la temperatura y con el valor de la relación [NH3]Total/[Cu]Total depende la solubilidad del Cu(II.

  11. Preparation and characterization of poly-(methacrylatoethyl trimethylammonium chloride-co-vinylbenzyl chloride-co-ethylene dimethacrylate monolith

    Directory of Open Access Journals (Sweden)

    Eko Malis

    2015-05-01

    Full Text Available A polymer monolithic column, poly-(methacrylatoethyltrimethylammonium chloride-co-vinylbenzyl chloride-co-ethylene dimethacrylate or poly-(MATE-co-VBC-co-EDMA was successfully prepared in the current study by one-step thermally initiated in situ polymerization, confined in a steel tubing of 0.5 mm i.d. and 1/16” o.d. The monoliths were prepared from methacrylatoethyltrimethylammonium chloride (MATE and vinylbenzyl chloride (VBC as monomer and ethylene dimethacrylate (EDMA as crosslinker using a binary porogen system of 1-propanol and 1,4-butanediol. The inner wall of steel tubing was pretreated with 3-methacryloxypropyl-trimethoxysilane (MAPS. In order to obtain monolith with adequate column efficiency and low flow resistance, some parameters such as total monomer concentration (%T and crosslinker concentration (%C were optimized. The morphology of this monolith was assessed by scanning electron microscopy (SEM. The properties of the monolithic column, such as permeability, binding capacity, and pore size distribution were also characterized in detail. From the results of the characterization of all monolith variation, monolith with %T 30 %C 50 and %T 35 %C 50 give the best characteristic. These monoliths have high permeability, adequate molecular recognition sites (represented with binding capacity value of over 20 mg/mL, and have over 80% flow through pores in their pore structure contribute to low flow resistance. The resulted monolithic columns have promising potential for dual mode liquid chromatography. MATE may contribute for anion-exchange while VBC may responsible for reversed-phase liquid chromatography.

  12. 21 CFR 878.4015 - Wound dressing with poly (diallyl dimethyl ammonium chloride) (pDADMAC) additive.

    Science.gov (United States)

    2010-04-01

    ... ammonium chloride) (pDADMAC) additive. 878.4015 Section 878.4015 Food and Drugs FOOD AND DRUG... DEVICES Surgical Devices § 878.4015 Wound dressing with poly (diallyl dimethyl ammonium chloride) (pDADMAC... Dressing With Poly (Diallyl Dimethyl Ammonium Chloride) (pDADMAC) Additive.” See § 878.1(e)...

  13. 40 CFR 721.10154 - Quaternary ammonium compounds, dicoco alkyldimethyl, chlorides, reaction products with silica.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Quaternary ammonium compounds, dicoco alkyldimethyl, chlorides, reaction products with silica. 721.10154 Section 721.10154 Protection of Environment... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10154 Quaternary ammonium...

  14. 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.

  15. 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.

  16. 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.

  17. Effect of Ammonium Molybdate Inhibition on Corrosion Behaviour of Mild Steel in Chloride and Sulphide Media

    Directory of Open Access Journals (Sweden)

    Ayo S. Afolabi

    2010-10-01

    Full Text Available The corrosion inhibition of mild steel in 3.0 M sodium chloride and 0.5 M sodium sulphide using various concentrations of ammonium molybdate was investigated in this work. The inhibition effect of this reagent in these media was monitored by weight loss and pH measurements. The analyses of the weight loss results showed that the corrosion susceptibility of mild steel in 3.0 M sodium chloride was more pronounced than in 0.5 M of sodium sulphide due to the aggressive chloride ions in the former and the weak nature of the latter. Ammonium molybdate produced a better inhibition performance of mild steel in 0.5 M sodium suphide than in 3.0 M sodium chloride medium and the higher the concentration of ammonium molybdate the more the inhibition performance on mild steel in the media studied. Optimum inhibition was obtained at 2.5 M ammonium molybdate in both media. The pH values in chloride medium remained acidic throughout the exposure period while those of sulphide medium shifted to alkaline region with exposure time; an effect that was traceable to higher inhibition obtained in the latter medium.

  18. Quaternary ammonium salt N-(dodecyloxycarboxymethyl)-N,N,N-trimethyl ammonium chloride induced alterations in Saccharomyces cerevisiae physiology

    Indian Academy of Sciences (India)

    EWA OBŁĄK; AGATA PIECUCH; EWA MACIASZCZYK-DZIUBIŃSKA; DONATA WAWRZYCKA

    2016-12-01

    We investigated the influence of the quaternary ammonium salt (QAS) called IM (N-(dodecyloxycarboxymethyl)-N,N,N-trimethyl ammonium chloride) on yeast cells of the parental strain and the IM-resistant mutant (EO25 IMR)growth. The phenotype of this mutant was pleiotropic. The IMR mutant exhibited resistance to ethanol, osmotic shockand oxidative stress, as well as increased sensitivity to UV. Moreover, it was noted that mutant EO25 appears to havean increased resistance to clotrimazole, ketoconazole, fluconazole, nystatin and cycloheximide. It also toleratedgrowth in the presence of crystal violet, DTT and metals (selenium, tin, arsenic). It was shown that the presence ofIM decreased ergosterol level in mutant plasma membrane and increased its unsaturation. These results indicatechanges in the cell lipid composition. Western blot analysis showed the induction of Pma1 level by IM. RT-PCRrevealed an increased PMA1 expression after IM treatment.

  19. Effect of cotton pectin content and bioscouring on alkyl-dimethyl-benzyl-ammonium chloride adsorption

    Science.gov (United States)

    Our previous research has shown both the rate and the total amount of alkyl-dimethyl-benzyl-ammonium chloride (ADBAC) exhausted from a bulk solution of ADBAC are significantly greater for greige cotton nonwovens than cotton nonwovens that have been both scoured and bleached. The presence of pectin ...

  20. Adsorption of alkyl-dimethyl-benzyl-ammonium chloride on differently pretreated nonwoven cotton substrate

    Science.gov (United States)

    The adsorption of alkyl-dimethyl-benzyl-ammonium chloride (ADBAC), a cationic surfactant commonly employed as an antimicrobial agent, on greige, alkaline scoured, and bleached nonwoven cotton fabrics was investigated at varying surfactant concentrations and liquor ratios using UV-vis absorption spec...

  1. Ammonium Chloride Promoted Palladium-Catalyzed Ullmann Coupling of Aryl Bromide

    Institute of Scientific and Technical Information of China (English)

    李金恒; 梁云; 刘文杰; 唐石; 谢叶香

    2004-01-01

    In water, ammonium chloride was found to promote palladium-catalyzed Ullmann coupling reactions of aryl bromides. In the presence of Pd/C, zinc, NH4Cl, and water, coupling of various aryl bromides was carried out smoothly to afford the corresponding homocoupling products in moderate yields.

  2. Erythrocyte lysis in isotonic solution of ammonium chloride: Theoretical modelling and experimental verification

    NARCIS (Netherlands)

    Chernyshev, A.V.; Tarasov, P.A.; Semianov, K.A.; Nekrasov, V.M.; Hoekstra, A.G.; Maltsev, V.P.

    2008-01-01

    A mathematical model of erythrocyte lysis in isotonic solution of ammonium chloride is presented in frames of a statistical approach. The model is used to evaluate several parameters of mature erythrocytes (volume, surface area, hemoglobin concentration, number of anionic exchangers on membrane, ela

  3. Resistance of Pseudomonas to Quaternary Ammonium Compounds. I. Growth in Benzalkonium Chloride Solution

    Science.gov (United States)

    Adair, Frank W.; Geftic, Sam G.; Gelzer, Justus

    1969-01-01

    Resistant cells of Pseudomonas aeruginosa and a waterborne Pseudomonas sp. (strain Z-R) were able to multiply in nitrogen-free minimal salts solution containing various concentrations of commercially prepared, ammonium acetate-buffered benzalkonium chloride (CBC), a potent antimicrobial agent. As the CBC concentration increased, growth increased until a point was reached at which the extent of growth leveled off or was completely depressed. Minimal salts solutions of pure benzalkonium chloride (PBC) containing no ammonium acetate did not support bacterial growth. When ammonium acetate was added to PBC solutions in the same concentrations found in CBC solutions, growth patterns developed that were comparable to those found with CBC. Likewise, (NH4)2SO4 added to PBC solutions supported growth of both organisms. P. aeruginosa was initially resistant to CBC levels of 0.02% and it was adapted to tolerate levels as high as 0.36%. Strain Z-R was naturally resistant to 0.4% CBC. Since ammonium acetate, carried over by the CBC used in drug formulations and disinfectant solutions, has the potential to support the growth of resistant bacteria and thus make possible the risk of serious infection, it is suggested that regulations allowing the presence of ammonium acetate in CBC solution be reconsidered. PMID:4984761

  4. FTIR analysis of adsorption of poly diallyl-dimethyl-ammonium chloride on kaolinite

    Institute of Scientific and Technical Information of China (English)

    SUN Wei; LIU Wen-li; HU Yue-hua

    2008-01-01

    The flocculation behavior of ultrafine kaolinite suspension was investigated through settlement tests and FTIR method wasemployed to probe the adsorption mechanism of flocculant on kaolinite. The results show that the maximum settling rate of kaoliniteoccurs at pH value of 3.33, which is close to the point of zero charge(PZC) of kaolinite (3.5). This result is in good agreement withthe double electric layer theory. Kaolinite suspension reaches the largest settling rate at a low concentration of 39 g/t for polydiallyl-dimethyl-ammonium chloride(PDADMA) flocculant, whereas for polyacrylamides(PAM) the dosage is required to be 500 g/t.When macromolecule polymer is adsorbed on surface, kaolinite particles may be flocculant due to the bridging effect. There arecation flocculant characteristic bands on the spectrum of kaolinite but no obvious shifting. Thus, the adsorption of polydiallyl-dimethyi-ammonium chloride on kaolinite surface is physical adsorption.

  5. Comparison of Theoretical and Experimental Values for the Effective Heat of Ablation of Ammonium Chloride

    Science.gov (United States)

    Welker, Jean E.

    1960-01-01

    Thermodynamic properties of ammonium chloride have been obtained and applied to a theoretical analysis of the shielding mechanism which reduces the rate of heat transfer to a body when ablation takes place at the surface. The analysis has considered the mechanism as one in which the material sublimes directly from the solid to the vapor phase. The results of the computation are compared with the experimental results obtained from the Langley 700-kilowatt arc jet.

  6. Preparation, characterization and antibacterial activity of O-acetyl-chitosan-N-2-hydroxypropyl trimethyl ammonium chloride.

    Science.gov (United States)

    Cai, Jinping; Dang, Qifeng; Liu, Chengsheng; Wang, Teng; Fan, Bing; Yan, Jingquan; Xu, Yanyan

    2015-09-01

    Chitosan-N-2-hydroxypropyl trimethyl ammonium chloride (QTS) was prepared by reaction of chitosan (CS) and glycidyl trimethylammonium chloride. Later, O-acetyl-chitosan-N-2-hydroxypropyl trimethyl ammonium chloride (AQTS) was synthesized by reaction of QTS with acetic acid in the presence of SOCl2. Both derivatives were characterized by FTIR, (1)H NMR, TGA, and XRD techniques. The degree of quaternization of QTS was 85.5%, and the degree of acetyl (DA) of AQTS was from 1.63 to 2.31. Compared with CS, the solubility of QTS and AQTS was improved at different levels, especially AQTS, it could be dissolved in many organic solvents, water, and aqueous solution. Notably, the solubility of AQTS in organic solvents increased as DA increased, while the solubility in water was reversed. The results of CS, QTS, and AQTS against Escherichia coli and Staphylococcus aureus showed that QTS and AQTS exhibited higher antibacterial activity than CS, and the antibacterial activity of AQTS decreased with increased DA. Moreover, the inhibition effect was AQTS1 (DA 1.63)>AQTS2 (DA 2.02)>QTS>AQTS3 (DA 2.31). On the basis of the results of the present study, it could be emphasized that hydrophobicity and positive charge density might strongly affect the antibacterial activity of quaternary ammonium chitosan derivatives.

  7. Erythrocyte lysis in isotonic solution of ammonium chloride: theoretical modeling and experimental verification.

    Science.gov (United States)

    Chernyshev, Andrey V; Tarasov, Peter A; Semianov, Konstantin A; Nekrasov, Vyacheslav M; Hoekstra, Alfons G; Maltsev, Valeri P

    2008-03-07

    A mathematical model of erythrocyte lysis in isotonic solution of ammonium chloride is presented in frames of a statistical approach. The model is used to evaluate several parameters of mature erythrocytes (volume, surface area, hemoglobin concentration, number of anionic exchangers on membrane, elasticity and critical tension of membrane) through their sphering and lysis measured by a scanning flow cytometer (SFC). SFC allows measuring the light-scattering pattern (indicatrix) of an individual cell over the angular range from 10 degrees to 60 degrees . Comparison of the experimentally measured and theoretically calculated light scattering patterns allows discrimination of spherical from non-spherical erythrocytes and evaluation of volume and hemoglobin concentration for individual spherical cells. Three different processes were applied for erythrocytes sphering: (1) colloid osmotic lysis in isotonic solution of ammonium chloride, (2) isovolumetric sphering in the presence of sodium dodecyl sulphate and albumin in neutrally buffered isotonic saline, and (3) osmotic fragility test in hypotonic media. For the hemolysis in ammonium chloride, the evolution of distributions of sphered erythrocytes on volume and hemoglobin content was monitored in real-time experiments. The analysis of experimental data was performed in the context of a statistical approach, taking into account that parameters of erythrocytes vary from cell to cell.

  8. [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.

  9. Hydrolysis of cellulose catalyzed by quaternary ammonium perrhenates in 1-allyl-3-methylimidazolium chloride.

    Science.gov (United States)

    Wang, Jingyun; Zhou, Mingdong; Yuan, Yuguo; Zhang, Quan; Fang, Xiangchen; Zang, Shuliang

    2015-12-01

    Quaternary ammonium perrhenates were applied as catalyst to promote the hydrolysis of cellulose in 1-allyl-3-methylimidazolium chloride ([Amim]Cl). The quaternary ammonium perrhenates displayed good catalytic performance for cellulose hydrolysis. Water was also proven to be effective to promote cellulose hydrolysis. Accordingly, 97% of total reduced sugar (TRS) and 42% of glucose yields could be obtained under the condition of using 5mol% of tetramethyl ammonium perrhenate as catalyst, 70μL of water, ca. 0.6mmol of microcrystalline cellulose (MCC) and 2.0g of [Amim]Cl as solvent under microwave irradiation for 30min at 150°C (optimal conditions). The influence of quaternary ammonium cation on the efficiency of cellulose hydrolysis was examined based on different cation structures of perrhenates. The mechanism on perrhenate catalyzed cellulose hydrolysis is also discussed, whereas hydrogen bonding between ReO4 anion and hydroxyl groups of cellulose is assumed to be the key step for depolymerization of cellulose.

  10. Superposition model study of Cr3+ doped tetra methyl ammonium cadmium chloride.

    Science.gov (United States)

    Kripal, Ram; Yadav, Awadhesh Kumar

    2015-02-25

    The zero field splitting parameter D of Cr(3+) doped in tetra methyl ammonium cadmium chloride (TMCC) is calculated with perturbation formula using microscopic spin Hamiltonian theory and crystal field parameters from superposition model. The theoretically calculated ZFS parameter for Cr(3+) in TMCC single crystal is compared with the experimental value obtained by electron paramagnetic resonance (EPR). The local structure distortion is considered to obtain the crystal field parameters. The theoretical study gives the ZFS parameter D similar to that from experiment. However, calculation considering small distortion in local structure around Cr(3+) gives better agreement with the experimental value of ZFS parameter.

  11. A Study of Substituted Aliphatic Sulphides on the Corrosion Behaviour of Zinc in Ammonium Chloride Solution

    Directory of Open Access Journals (Sweden)

    R. Venckatesh

    2007-01-01

    Full Text Available Sulphur containing organic compounds decreases the corrosion rate by increasing the hydrogen over potential on zinc metal due to their electron donating groups. Their inhibiting effect was found to be associated with their adsorption on the active centers of the metal. The inhibition efficiencies of some aliphatic sulphides in ammonium chloride solution have been studied by weight loss studies, polarization and impedance measurements. The effect of substituent groups is correlated with their inhibition performance. These studies due to their relevance in Zn-Manganese dry batteries assume their importance.

  12. 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.

  13. Influence of ammonium chloride feeding time and light intensity on the cultivation of Spirulina (Arthrospira) platensis.

    Science.gov (United States)

    Bezerra, Raquel Pedrosa; Matsudo, Marcelo Chuei; Converti, Attilio; Sato, Sunao; de Carvalho, João Carlos Monteiro

    2008-06-01

    This study dealt with the influence of both the feeding time and light intensity on the fed-batch culture of the cyanobacterium Spirulina (Arthrospira) platensis using ammonium chloride as a nitrogen source. For this purpose, a 2(2) plus star central composite experimental design combined with response surface methodology was employed, and the maximum cell concentration (X(m)), the cell productivity (P(X)), and the yield of biomass on nitrogen (Y(X/N)) were selected as the response variables. The optimum values of X(m) (1,833 mg L(-1)) and Y(X/N) (5.9 g g(-1)) estimated by the model at light intensity of 13 klux and feeding time of 17.2 days were very close to those obtained experimentally under these conditions (X(m) = 1,771 +/- 41 mg L(-1); Y(X/N) = 5.7 +/- 0.17 g g(-1)). The cell productivity was a decreasing function of the ammonium chloride feeding time and a quadratic function of the light intensity. The protein and lipid contents of dry biomass collected at the end of cultivations were shown to decrease with increasing light intensity.

  14. A simple and convenient method for direct α-chlorination of ketones with ammonium chloride and Oxone

    Institute of Scientific and Technical Information of China (English)

    Zhong Shi Zhou; Li Li; Xue Han He

    2012-01-01

    When ketones were treated with ammonium chloride and Oxone(R) in MeOH at room temperature,a direct α-chlorination of ketones was occurred and a series of the corresponding α-chloroketones were obtained in moderate to good yields after 24 h.In this reaction,ammonium chloride was used as the source of chlorine and Oxone(R) was used as an oxidant.This method was simple,convenient and providing a novel procedure for preparation of α-chloroketones.

  15. 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.

  16. 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.

  17. Effect of Initial Concentrations on Solidification of Ammonium Chloride water Solution

    Institute of Scientific and Technical Information of China (English)

    1992-01-01

    The effect of initial concentrations on solidification of ammonium chloride water solution is numerically investigated in detail.The solidifying process.with the cold wall temperature lower than the eutectic temperature,is assumed to be one-dimensional,and controlled by heat conduction only.The simulation reveals that:(1) The solid-mush interface grows in a linear manner,while the growth rate of the mush-liquid interface decreases in a parabolic manner,with increasing initial concentrations.(2) The temperature field in the whole region has parabolic characteristics,but is shows a linear feature in the solid zone and mushy zone.(3) The concentration always has linear characteristics in the much.(4)The solid fraction distribution is strongly affected by the initial concertration.The solidification process shows quite different features,especially at small and high initial concentrations.

  18. 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.

  19. 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)

  20. Thermal decomposition behaviour of polyacrylamidomethyltrimethyl ammonium chloride in red mud separation process

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In order to provide references for selecting highly efficient red mud flocculants,the behaviour of polyacrylamidomethyltrimethyl ammonium chloride (PATAC) in red mud separation process was investigated.PATAC was employed as a flocculant for red mud separation from the caustic aluminate liquor at 95 ℃.The used red mud was generated from Chinese diaspore bauxite in Bayer process of alumina production.And the changes of PATAC before or after being treated in caustic solution at 95 ℃ were studied by thermogravimetry (TG) and Fourier transform infrared (FTIR) spectral analysis.The results show that PATAC fails in effectively flocculating red mud and PATAC is readily converted to a quaternary ammonium hydroxide (PATAH) in caustic solution.PATAH can be decomposed to a new polymer (HPATAH) even at 95 ℃.Furthermore,there is an intramolecular hydrogen bond formed in the HPATAH polymer chain with two functional groups of -CH2-OH and -CONH2.Therefore,the poor flocculation property of PATAC for red mud separation can be attributed to the thermal decomposition of PATAC in the caustic red mud slurry at 95 ℃ and the formation of intramolecular hydrogen bond in the polymer chain of HPATAH during the thermal decomposition,which causes the absorbable functional groups of PATAC to decrease greatly.

  1. N-Acetyl Cysteine (NAC)-Directed Detoxification of Methacryloxylethyl Cetyl Ammonium Chloride (DMAE-CB).

    Science.gov (United States)

    Jiao, Yang; Ma, Sai; Li, Jing; Shan, Lequn; Wang, Yingjie; Tian, Min; Yang, Yanwei; Sun, Jinlong; Ban, Jinghao; Chen, Jihua

    2015-01-01

    Methacryloxylethyl cetyl ammonium chloride (DMAE-CB) is a polymerizable antibacterial monomer and has been proved as an effective strategy to achieve bioactive bonding with reliable bacterial inhibitory effects. However, the toxicity of DMAE-CB may hamper its wide application in clinical situations. Thus, this study was designed to investigate the toxicity of DMAE-CB and explore the possible protective effects of N-acetyl cysteine (NAC). High performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS) analysis showed that chemical binding of NAC and DMAE-CB occurred in a time dependent manner. Pre-incubation of fourty-eight hours is required for adequate reaction between DMAE-CB and NAC. DMAE-CB reduced human dental pulp cells (hDPCs) viability in a dose-dependent manner. The toxic effects of DMAE-CB were accompanied by increased reactive oxygen species (ROS) level and reduced glutathione (GSH) content. NAC alleviated DMAE-CB-induced oxidative stress. Annexin V/ Propidium Iodide (PI) staining and Hoechst 33342 staining indicated that DMAE-CB induced apoptosis. Collapsed mitochondrial membrane potential (MMP) and activation of caspase-3 were also observed after DMAE-CB treatment. NAC rescued hDPCs from DMAE-CB-induced apoptosis, accompanied by lower level of MMP loss and caspase-3 activity. This study assists to elucidate the mechanism underlying the cytotoxic effects of DMAE-CB and provides theoretical supports for the searching of effective strategies to reduce toxicity of quaternary ammonium dental monomers.

  2. 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...

  3. 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.

  4. Introduction of poly[(2-acryloyloxyethyl trimethyl ammonium chloride)-co-(acrylic acid)] branches onto starch for cotton warp sizing.

    Science.gov (United States)

    Shen, Shiqi; Zhu, Zhifeng; Liu, Fengdan

    2016-03-15

    An attempt has been made to reveal the effect of amphoteric poly(2-acryloyloxyethyl trimethyl ammonium chloride-co-acrylic acid) [P(ATAC-co-AA)] branches grafted onto the backbones of starch upon the adhesion-to-cotton, film properties, and desizability of maize starch for cotton warp sizing. Starch-g-poly[(2-acryloyloxyethyl trimethyl ammonium chloride)-co-(acrylic acid) [S-g-P(ATAC-co-AA)] was prepared by the graft copolymerization of 2-acryloyloxyethyl trimethyl ammonium chloride (ATAC) and acrylic acid (AA) with acid-converted starch (ACS) in aqueous medium using Fe(2+)-H2O2 initiator. The adhesion was evaluated in term of bonding strength according to the FZ/T 15001-2008 whereas the film properties considered included tensile strength, work and percentage elongation at break. The evaluation was undertaken through the comparison of S-g-P(ATAC-co-AA) with ACS, starch-g-poly(acrylic acid), and starch-g-poly(2-acryloyloxyethyl trimethyl ammonium chloride). It was found that the amphoteric branch was able to significantly improve the adhesion and mitigate the brittleness of starch film. Zeta potential of cooked S-g-P(ATAC-co-AA) paste, depending on the mole ratio of ATAC to AA units on P(ATAC-co-AA) branches, had substantial effect on the adhesion and desizability. Increasing the mole ratio raised the potential, which favored the adhesion but disfavored the removal of S-g-P(ATAC-co-AA) from sized cotton warps. Electroneutral S-g-P(ATAC-co-AA) was superior to negatively grafted starch in adhesion and to positively grafted starch in desizability. Generally, it showed better sizing property than ACS, starch-g-poly(acrylic acid), and starch-g-poly(2-acryloyloxyethyl trimethyl ammonium chloride), and had potential in the application of cotton warp sizing.

  5. 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.

  6. Gamma radiation-induced grafting of acrylamide and dimethyl diallyl ammonium chloride onto starch.

    Science.gov (United States)

    Lv, Xiaohua; Song, Weiqiang; Ti, Yongzhou; Qu, Lingbo; Zhao, Zhiwei; Zheng, Hongjuan

    2013-01-30

    Corn starch graft copolymers were prepared from acrylamide/dimethyl diallyl ammonium chloride binary monomers (AM/DMDAAC) by a simultaneous radiation grafting method, and were characterized by FTIR and (1)H NMR techniques, weight measurement and titration method. The copolymers with high grafting ratio and high grafting efficiency of binary monomers were achieved at absorbed doses of 2 kGy and 3 kGy using a 6:9.8:4.2 (w/w/w) ratio of starch/AM/DMDAAC, but their cationic degrees were low. Grafting ratio, grafting efficiency and cationic degree of the copolymers increased with increasing AM content in comonomer mixtures and then decreased at 3kGy using a 6:14 ratio of starch:total comonomers, but their cationic degrees generally decreased with increasing AM content. The grafting ratio, the grafting efficiency and the cationic degree of the copolymers increased, but the grafting efficiency of DMDAAC decreased with varying starch/(AM+DMDAAC) ratio from 6:3 to 6:18 at 3 kGy by using a fixed 7:3 ratio of AM:DMDAAC.

  7. Mechanism of chlorinating lanthanum oxide and cerium oxide with ammonium chloride

    Institute of Scientific and Technical Information of China (English)

    朱国才; 李赋屏; 肖明贵

    2003-01-01

    Using ammonium chloride(NH4Cl)as a chlorinating agent,the effects of chlorinating temperature,at 300℃ for 90 min,and have no advantage to chlorination of lanthanum and cerium oxides at higher temperature.The thermal decomposition of LaCl3 and CeCl3 is carried out to explore the mechanism of chlorinating lanthanum and cerium oxides.At the same time,the chlorination of lanthanum and cerium oxides is not devoted to the HCl decomposed from NH4Cl,but to NH4Cl directly taking part in the chlorination of La2O3 and CeO2.The lanthanum and cerium oxides in chlorination firstly form intermediate LaOCl and CeOCl,and then transfer to LaCl3 and CeCl3,fither prove the existence of the intermediates LaOCl and CeOCl.Therefore the chlorinating temperature and time should strictly be controlled when the lanthanum oxide and cerium oxide are chlorinated with NH4 Cl.And over-dosage of NH4 Cl should be also applied in the process of chlorination.

  8. O-2'-hydroxypropyltrimethyl ammonium chloride chitosan nanoparticles for the delivery of live Newcastle disease vaccine.

    Science.gov (United States)

    Dai, Chunxiao; Kang, Hong; Yang, Wanqiu; Sun, Jinyan; Liu, Chunlong; Cheng, Guogang; Rong, Guangyu; Wang, Xiaohua; Wang, Xin; Jin, Zheng; Zhao, Kai

    2015-10-05

    A novel complex chitosan derivative, O-2'-hydroxypropyltrimethyl ammonium chloride chitosan (O-2'-HACC), was synthesized and used to make nanoparticles as a delivery vehicle for live attenuated Newcastle disease vaccine. We found that O-2'-HACC had high antimicrobial activity, low toxicity, and a high safety level. Newcastle disease virus (NDV) was then encapsulated in the O-2'-HACC nanoparticles (NDV/La Sota-O-2'-HACC-NPs) by the ionic crosslinking method, and the properties of the resulting nanoparticles were determined by transmission electron microscopy, Zeta potential analysis, Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, and X-ray diffraction. NDV/La Sota-O-2'-HACC-NPs had regular spherical morphologies and high stability, with an encapsulation efficiency of 95.68 ± 2.2% and a loading capacity of 58.75 ± 4.03%. An in vitro release assay indicated that release of NDV from NDV/La Sota-O-2'-HACC-NPs occurred slowly. Specific pathogen-free chickens immunized with NDV/La Sota-O-2'-HACC-NPs intranasally had much stronger cellular, humoral and mucosal immune responses than did those immunized intramuscularly or with live attenuated Newcastle disease vaccine. NDV/La Sota-O-2'-HACC-NPs are a novel drug delivery carrier with immense potential in medical applications.

  9. Adsorption kinetics of 3-alkoxy-2-hydroxypropyl trimethyl ammonium chloride at oil-water interface

    Science.gov (United States)

    Wei, Xi-lian; Wang, Xiu-hong; Liu, Jie; Sun, De-zhi; Yin, Bao-lin; Wang, Xiu-jie

    2012-11-01

    Dynamic interfacial tension (DIT) between aqueous solution of 3-alkoxy-2-hydroxypropyl trimethyl ammonium chloride (RnHTAC) and n-octane was measured using spinning drop method. The effects of RnHTAC concentration (the concentration below the CMC) and temperature on DIT have been investigated. The cause of the change of DIT with time has been discussed. The effective diffusion coefficient, Da, and the adsorption barrier, ɛa, have been obtained with extended Word-Tordai equation. The results show that the higher the concentration of the surfactant is, the smaller the DIT will be and the lower the curve of the DIT, and the aqueous RnHTAC solutions follow a mixed diffusion-activation adsorption mechanism. With increase of RnHTAC concentration in the bulk solution, Da decreases and ɛa increases. Da of aqueous R14HTAC solution decreases from 0.090 × 10-13 m2 s-1 to 0.081 × 10-13 m2 s-1 and ɛa increases from 10.12 kJ mol-1 to 11.89 kJ mol-1, with the temperature increasing from 30 °C to 50 °C. This phenomenon indicates that the diffusion tendency becomes weak with the strengthening of the interaction between the surfactant molecules and that the thermo-motion of molecules benefits interface adsorption.

  10. Surface chemical study on the covalent attachment of hydroxypropyltrimethyl ammonium chloride chitosan to titanium surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Xu Xiaofen; Wang Ling [School of Pharmacy, Shanghai Jiao Tong University, 800 Dong-chuan Road, Shanghai 200240 (China); Guo Shengrong, E-mail: srguo@sjtu.edu.cn [School of Pharmacy, Shanghai Jiao Tong University, 800 Dong-chuan Road, Shanghai 200240 (China); Lei Lei [School of Pharmacy, Shanghai Jiao Tong University, 800 Dong-chuan Road, Shanghai 200240 (China); Tang Tingting, E-mail: tingtingtang@hotmail.com [Shanghai Key Laboratory of Orthopedic Implant, Department of Orthopedic Surgery, Shanghai Ninth People' s Hospital, Shanghai Jiaotong University School of Medicine (China)

    2011-10-01

    An anti-microbial and bioactive coating could not only reduce the probability of infection related to titanium implants but also support the growth of surrounding osteogenic cells. Our previous study has showed that hydroxypropyltrimethyl ammonium chloride chitosan (HACC) with a DS (degrees of substitution) of 18% had improved solubility and significantly higher antibacterial activities against three bacteria which were usually associated with infections in orthopaedics. In the current study, HACC with a DS of 18% coating was bonded to titanium surface by a three-step process. The titanium surface after each individual reaction step was analyzed by X-ray photoelectron spectroscopy (XPS) and attenuated total reflection (ATR) of Fourier-transformed infrared (FT-IR) spectroscopy. The XPS results demonstrated that there were great changes in the atomic ratios of C/Ti, O/Ti, and N/Ti after each reaction step. The XPS high resolution and corresponding devolution spectra of carbon, oxygen, nitrogen, and titanium were also in good coordination with the anticipated reaction steps. Additionally, the absorption bands around 3365 cm{sup -1} (-OH vibration), 1664 cm{sup -1} (Amide I), 1165 cm{sup -1} ({nu}{sub as}, C-O-C bridge), and the broad absorption bands between 958 cm{sup -1} and 1155 cm{sup -1} (skeletal vibrations involving the C-O stretching of saccharide structure of HACC) verified that HACC was successfully attached to titanium surface.

  11. Synergy of ammonium chloride and moisture on perovskite crystallization for efficient printable mesoscopic solar cells

    Science.gov (United States)

    Rong, Yaoguang; Hou, Xiaomeng; Hu, Yue; Mei, Anyi; Liu, Linfeng; Wang, Ping; Han, Hongwei

    2017-01-01

    Organometal lead halide perovskites have been widely used as the light harvester for high-performance solar cells. However, typical perovskites of methylammonium lead halides (CH3NH3PbX3, X=Cl, Br, I) are usually sensitive to moisture in ambient air, and thus require an inert atmosphere to process. Here we demonstrate a moisture-induced transformation of perovskite crystals in a triple-layer scaffold of TiO2/ZrO2/Carbon to fabricate printable mesoscopic solar cells. An additive of ammonium chloride (NH4Cl) is employed to assist the crystallization of perovskite, wherein the formation and transition of intermediate CH3NH3X·NH4PbX3(H2O)2 (X=I or Cl) enables high-quality perovskite CH3NH3PbI3 crystals with preferential growth orientation. Correspondingly, the intrinsic perovskite devices based on CH3NH3PbI3 achieve an efficiency of 15.6% and a lifetime of over 130 days in ambient condition with 30% relative humidity. This ambient-processed printable perovskite solar cell provides a promising prospect for mass production, and will promote the development of perovskite-based photovoltaics. PMID:28240286

  12. 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.

  13. 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)

  14. The physiological and morphological phenotype of a yeast mutant resistant to the quaternary ammonium salt N-(dodecyloxycarboxymethyl)-N,N,N-trimethyl ammonium chloride.

    Science.gov (United States)

    Obłak, Ewa; Gamian, Andrzej; Adamski, Ryszard; Ułaszewski, Stanisław

    2010-06-01

    We investigated the action of the quaternary ammonium salt (QAS) called IM (N-(dodecyloxycarboxymethyl)-N,N,N-trimethyl ammonium chloride) on Saccharomyces cerevisiae yeast cells. Changes in the yeast cell ultrastructure were confirmed by electron microscopy. We treated resistant mutant cells with QAS, and confirmed destruction of the mutant cytoplasm, an increase in the thickness of the cell wall, separation of the cell wall from the cytoplasm, and the accumulation of numerous lipid droplets. We also observed a relatively high production of lipids in the cells of the parental wild-type strain Sigma1278b and in its IM-resistant (IM(R)) mutant in the presence of the QAS. The IM(R) mutant showed increased sensitivity to CaCl(2) and SDS, and resistance to ethidium bromide, chloramphenicol, erythromycin and osmotic shock. It also tolerated growth at low pH. We suggest that the resistance to IM could be connected with the level of permeability of the cell membrane because the IM(R) mutant was sensitive to this compound in vivo in the presence of SDS and guanidine hydrochloride, which cause increased permeability of the cell plasma membrane.

  15. A solid phase honey-like channel method for synthesizing urea-ammonium chloride cocrystals on industrial scale

    Science.gov (United States)

    Xue, Bingchun; Mao, Meiling; Liu, Yanhong; Guo, Jinyu; Li, Jing; Liu, Erbao

    2016-05-01

    Unanticipated a new and simple urea-ammonium chloride cocrystal synthesis method on industrial scale was found during attempts to produce a kind of granulated compound fertilizer. The aggregation of fertilizer powder can make the interaction among particles from loose to close, which generate mechanical pressure and in turn act as the driving force to benefit cocrystal growth. Additionally, the honeycomb-like channels constructed by other coexisting compound make the water evaporates more moderate, which can help the formation of supersaturated solution at suitable rate, further promote the growth of cocrystal. This approach possibly opens a new route toward the developing methodologies for cocrystal synthesis.

  16. 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.

  17. Ion-pair hollow-fiber liquid-phase microextraction of the quaternary ammonium surfactant dicocodimethylammonium chloride.

    Science.gov (United States)

    Hultgren, Sofie; Larsson, Niklas; Nilsson, Bo F; Jönsson, Jan Ake

    2009-02-01

    A two-phase hollow-fiber (HF) liquid-phase microextraction (LPME) method was developed for determination of a quaternary ammonium compound surfactant, dicocodimethylammonium chloride, in aqueous samples. The porous HF was fixed on a metal rod support and was impregnated with approximately 6.6 microL of organic extractant, which was immobilized in the HF pores. Surfactant extraction was facilitated by addition of carboxylic acid to the sample forming neutral ion pairs with the quaternary ammonium compound. After extraction, the analyte was transferred from the organic extractant in the fiber pores by dissolving the 1-octanol into 100 microL methanol. The methanol extract was analyzed by liquid chromatography-mass spectrometry. The method was optimized (with optimized parameters in brackets) with regard to type of organic extractant (1-octanol), fiber length (2 cm), choice and concentration of anionic carrier (600 microg L(-1) octanoate), procedure of transfer to methanol (15-min sonication), sample volume (250 mL), extraction time (17 h), pH (10), and ionic strength (50 mM carbonate). Aspects influencing repeatability in LPME of (quaternary ammonium) surfactants are discussed. The enrichment factor achieved in 250-mL carbonate buffer was around 400. Due to matrix effects, the enrichment factors achieved when industrial process water was analyzed were 120 or about 30% of that in carbonate buffer. Detection limits of 0.3 microg L(-1) in carbonate buffer and 0.9 microg L(-1) in industrial process water were obtained. If the studied compound is seen as a model substance representing quaternary dialkylated dimethylated ammonium surfactants in general, the developed method may be applied to other quaternary ammonium surfactants.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. Corrosion mitigation of N-(2-hydroxy-3-trimethyl ammonium)propyl chitosan chloride as inhibitor on mild steel.

    Science.gov (United States)

    Sangeetha, Y; Meenakshi, S; SairamSundaram, C

    2015-01-01

    The biopolymer N-(2-hydroxy-3-trimethyl ammonium)propyl chitosan chloride (HTACC) was synthesised and its influence as a novel corrosion inhibitor on mild steel in 1M HCl was studied using gravimetric and electrochemical experiments. The compound obtained was characterised using FTIR and NMR studies. The inhibition efficiency increased with the increase in concentration and reached a maximum of 98.9% at 500 ppm concentration. Polarisation studies revealed that HTACC acts both as anodic and cathodic inhibitor. Electrochemical impedance studies confirmed that the inhibition is through adsorption on the metal surface. The extent of inhibition exhibits a negative trend with increase in temperature. Langmuir isotherm provides the best description on the adsorption nature of the inhibitor. SEM analysis indicated the presence of protective film formed by the inhibitor on the metal surface.

  3. 磷酸二氢钙和氯化钾对氯化铵处理黄泥土水溶性铵态氮和硝态氮的影响%Effects of Monocalcium Phosphate and Potassium Chloride on Water-soluble Ammonium Nitrogen and Nitrate Nitrogen in Paddy Soil Treated with Ammonium Chloride

    Institute of Scientific and Technical Information of China (English)

    李寿田; 周健民; 王火焰; 杜昌文; 陈小琴; 单迎东; 黄翠林

    2012-01-01

    In agriculture production, it is very common to apply considerable quantities of nitrogen, phosphorus and potassium fertilizers by compounding or apply compound fertilizers, thus nutrients translocation, transformation, uptake and metabolism will be influenced profoundly by interaction of nitrogen, phosphorus and potassium in soils. In this article, the effects of monocalcium phosphate and potassium chloride on water-soluble ammonium nitrogen and nitrate nitrogen in paddy soil treated with ammonium chloride were studied. The results showed that content of water-soluble ammonium nitrogen decreased and that of nitrate nitrogen increased with the extension of culture time, and there was significant correlation between the decrease of water-soluble ammonium nitrogen content and the increase of nitrate nitrogen content. The content of water-soluble ammonium nitrogen in soil treated with monocalcium phosphate and ammonium chloride was significantly higher than that of soil treated with ammonium chloride at the middle culture time, because the transformation of ammonium nitrogen to other forms of nitrogen was retarded by monocalcium phosphate, the conten of nitrate nitrogen was inhibited by monocalcium phosphate at the middle and late culture time. The content of water-soluble ammonium nitrogen in soil treated with potassium chloride and ammonium chloride at the early and middle culture time increased compared with that of soil treated ammonium chloride, and the content of nitrate nitrogen was inhibited by potassium chloride at the late culture time. Thus, application of ammonium chloride and potassium chloride, or ammonium chloride and monocalcium phosphate, or ammonium chloride and monocalcium phosphate and potassium chloride together play important roles in improving nitrogen use efficiency and reducing nitrate leaching loss.%氮磷钾是农业生产中大量施用并且经常共同施用的肥料,三者在土壤中的相互作用对养分的迁移转化、吸收和

  4. Benzalkonium chloride (BAC) and dimethyldioctadecyl-ammonium bromide (DDAB), two common quaternary ammonium compounds, cause genotoxic effects in mammalian and plant cells at environmentally relevant concentrations.

    Science.gov (United States)

    Ferk, F; Misík, M; Hoelzl, C; Uhl, M; Fuerhacker, M; Grillitsch, B; Parzefall, W; Nersesyan, A; Micieta, K; Grummt, T; Ehrlich, V; Knasmüller, S

    2007-11-01

    Quaternary ammonium compounds (QACs) are cationic surfactants that are widely used as disinfectants. In the present study, we tested two important representatives, namely, benzalkonium chloride (BAC) and dimethyldioctadecyl-ammonium bromide (DDAB) in four genotoxicity tests, namely, in the Salmonella/microsome assay with strains TA 98, TA 100 and TA 102, in the single-cell gel electrophoresis (SCGE) assay with primary rat hepatocytes and in micronucleus (MN) assays with peripheral human lymphocytes and with root tip cells of Vicia faba. In the bacterial experiments, consistently negative results were obtained in the dose range between 0.001 and 110 microg per plate in the presence and absence of metabolic activation while significant induction of DNA migration was detected in the liver cells. With BAC, a moderate but significant effect was found with an exposure concentration of 1.0 mg/l while DDAB caused damage at lower doses (0.3 mg/l). The effects were not altered when the nuclei were treated with formamidopyridine glycosylase, indicating that they are not due to formation of oxidized purines. The MN assays with blood cells were carried out under identical conditions to the SCGE experiments and a significant increase was seen at the highest dose levels (BAC: 1.0 and 3.0 mg/l; DDAB: 1 mg/l). Both compounds also caused significant induction of MN as well as inhibition of cell division in plant cells, the lowest effective levels were 1.0 and 10 mg/l for DDAB and BAC, respectively. Our findings show that both chemicals induce moderate but significant genotoxic effects in eukaryotic cells at concentrations which are found in wastewaters and indicate that their release into the environment may cause genetic damage in exposed organisms. Furthermore, the direct contact of humans to QAC-containing detergents and pharmaceuticals that contain substantially higher concentrations than those which were required to cause effects in eukaryotic cells in the present study should

  5. Adsorption of alkyl-dimethyl-benzyl-ammonium chloride on low-weight greige and bleached cotton nonwovens in different aqueous environments

    Science.gov (United States)

    Previous research has shown the adsorption of alkyl-dimethyl-benzyl-ammonium chloride (ADBAC) on cotton nonwovens is dependent on pretreatment of the substrate, more specifically whether it is greige or bleached fabric. In this work we examine the effect of varying the chemical and physical propert...

  6. 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...

  7. Effect of varying nonwoven cotton substrate and the properties of the surfactant solution upon the adsorption of aqueous solutions of alkyl-dimethyl-benzyl-ammonium chloride

    Science.gov (United States)

    The adsorption of alkyl-dimethyl-benzyl-ammonium chloride (ADBAC), a cationic surfactant commonly employed as an antimicrobial agent, on greige, alkaline scoured, and bleached nonwoven cotton fabrics was investigated at varying surfactant concentrations and liquor ratios using UV-vis absorption spec...

  8. Indirect Determination of CTMAB with Sodium Chloride and Ammonium Thiocyanate by Floatation and Separation of Zinc

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A new method for indirect determination of cetyl-trimethyl ammonium bromide (CTMAB) with NaCl and NH4SCN by floatation and separation of zinc has been studied. The study shows that Zn(II) can associate with NH4SCN and CTMAB to form insoluble ternary ion-association complex, and the precipitate can float on the surface of the liquid phase. A good linear relationship is observed between the floatation yield (E%) of Zn(II) and the amount of CTMAB. On the ground, CTMAB can be indirectly determined by determining E% of Zn(II). The results were satisfactory.

  9. 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。

  10. The optical constants of several atmospheric aerosol species - Ammonium sulfate, aluminum oxide, and sodium chloride

    Science.gov (United States)

    Toon, O. B.; Pollack, J. B.; Khare, B. N.

    1976-01-01

    An investigation is conducted of problems which are related to a use of measured optical constants in the simulation of the optical constants of real atmospheric aerosols. The techniques of measuring optical constants are discussed, taking into account transmission measurements through homogeneous and inhomogeneous materials, the immersion of a material in a liquid of a known refractive index, the consideration of the minimum deviation angle of prism measurement, the interference of multiply reflected light, reflectivity measurements, and aspects of mathematical analysis. Graphs show the real and the imaginary part of the refractive index as a function of wavelength for aluminum oxide, NaCl, and ammonium sulfate. Tables are provided for the dispersion parameters and the optical constants.

  11. 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.

  12. Isolation and Characterization of 1,3-Bis(vinylbenzylthymine: Copolymerization with Vinylbenzyl Thymine Ammonium Chloride

    Directory of Open Access Journals (Sweden)

    Ngoc Chau H. Vy

    2017-01-01

    Full Text Available A novel bioinspired molecule, 1,3-bis(vinylbenzylthymine (bisVBT, was isolated as a by-product during the synthesis of 1-(4-vinylbenzylthymine (VBT and analyzed with various techniques: NMR, IR, and Single-Crystal X-ray Diffraction. In addition to embodying all the desired characteristics of VBT (i.e., having the ability to undergo a 2π+2π photodimerization reaction upon UV irradiation, a derivatization site, hydrogen bonding sites, and aromatic stacking ability the bisVBT monomer has the added benefit of having two vinyl groups for cross-polymerization. Copolymerizing the bisVBT monomer with the charged monomer vinylbenzyl triethylammonium (VBA chloride, different copolymers/terpolymers/cross-linked network were obtained, as it was shown by the absence of the vinyl resonance in the NMR spectra. Thermal Gravimetric Analysis (TGA and Differential Scanning Calorimetry (DSC showed an indication of materials with low degree of cross-linking. A Gel Permeation Chromatography (GPC method was improved to better characterize the molecular weight distributions of the cationic structures. Preliminary qualitative cross-linking studies were performed on bisVBT-VBA copolymers, and a comparison with VBT-VBA copolymers is presented.

  13. 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.

  14. Synthesis, in vitro and in vivo evaluation of new norcantharidin-conjugated hydroxypropyltrimethyl ammonium chloride chitosan derivatives as polymer therapeutics.

    Science.gov (United States)

    Xu, Xiaofen; Li, Yanggong; Wang, Feihu; Lv, Li; Liu, Jieying; Li, Mingna; Guo, Aijie; Jiang, Jinjun; Shen, Yuanyuan; Guo, Shengrong

    2013-09-10

    New norcantharidin-conjugated hydroxypropyltrimethyl ammonium chloride chitosan derivatives (NCTD-HACCs) were synthesized and characterized by (1)H NMR, Fourier-transform infrared spectroscopy (FT-IR), and wide-angle X-ray diffraction (WAXD). Two NCTD-HACCs with different degrees of substitution (DS) (12.2% and 24.8%) were obtained, which had good water solubility. NCTD was released from the NCTD-HACCs via hydrolysis, faster in pH 5.0 than pH 7.4 and presenting one biphasic drug release pattern with rapid release at the initial stage and slow release later. Fluorescence microscope and flow cytometry analysis demonstrated that the NCTD-HACC was endocytosized into MGC80-3 cells and the uptaken amount increased as incubation time. Compared with free NCTD, the NCTD-HACCs showed lower in vitro anti-tumor activity against human gastric cancer MGC80-3 cells, but higher in vivo tumor growth inhibition in S180 tumor-bearing mice. The in vivo near-infrared (NIR) fluorescence real-time imaging result showed the fluorescence intensity in tumor was much higher than that in heart, liver, spleen and lung (except kidney) after i.v. injection of the FITC-labeled NCTD-HACC2, indicating specific accumulation of the NCTD-HACC in tumor.

  15. Synthesis and characterization of N-(2-hydroxy)propyl-3-trimethyl ammonium chitosan chloride for potential application in gene delivery.

    Science.gov (United States)

    Xiao, Bo; Wan, Ying; Wang, Xiaoyu; Zha, Qichen; Liu, Haoming; Qiu, Zhiye; Zhang, Shengmin

    2012-03-01

    A series of N-(2-hydroxy)propyl-3-trimethyl ammonium chitosan chloride (HTCC) samples with various degrees of quaternization ranging from 12.4 to 43.7% was synthesized. The structures and properties of HTCC were investigated by FT-IR, (1)H NMR, conductometric titration and XRD analysis. It was found that HTCC had a more amorphous structure than chitosan. HTCC samples showed significantly lower cytotoxicity than polyethyleneimine in HepG2 and HeLa cell lines. The samples spontaneously formed complexes with pGL3 luciferase plasmid. These complexes had desirable particle sizes (160-300 nm) and zeta potentials (10.8-18.7 mV) when the weight ratios of HTCC to plasmid altered in the range of 3:1-20:1. In vitro gene transfection results indicated that HTCC had significantly high transfection efficiency compared with chitosan for delivering pGL3 luciferase plasmid to HeLa cells. The results suggest that HTCC could be a promising non-viral vector for safe and efficient DNA delivery.

  16. EFFECT OF RADIATION ON HIGH-CHARGE-DENSITY POLYDIALLY-DIMETHYL AMMONIUM CHLORIDE IN DILUTE AQUEOUS SOLUTION

    Institute of Scientific and Technical Information of China (English)

    Ya-long Zhang; Min Yi; Jing Ren; Hong-fei Ha

    2003-01-01

    The effect of radiation on high-charge-density cationic polymer, polydiallyl-dimethyl ammonium chloride (polyDADMAC), in dilute aqueous solution was investigated. The irradiated samples were characterized in terms of reduced viscosity and electric conductivity. The crosslinking reaction of polyDADMAC chains occurs preferentially in the irradiated samples at a concentration of polyDADMAC higher than 1.3 g/100 mL that was induced indirectly by the OH radicals, one of the radiolysis products of water. In more dilute samples (less than 0.8 g/100 mL) the chain scission of macro radicals appears to be the main reaction. N2O atmosphere enhances the erosslinking due to the extra OH radicals produced by reaction between N2O and eaq, another radiolysis products of water. Methanol and some mineral salts such as KC1, KBr inhibit the crosslinking to a certain extent. The mechanism of sensitization and inhibition is discussed in detail.

  17. 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.

  18. Effects of sodium bicarbonate and ammonium chloride pre-treatments on PEPT2 (SLC15A2) mediated renal clearance of cephalexin in healthy subjects.

    Science.gov (United States)

    Liu, Rui; Tang, Audrey May Yi; Tan, Yen Ling; Limenta, Lie Michael George; Lee, Edmund Jon Deoon

    2011-01-01

    PEPT2 mediates the H(+) gradient-driving reabsorption of di- and tri-peptides, and various peptidomimetic compounds in the kidney. This study examines the influence of urinary pH modification through sodium bicarbonate and ammonium chloride pre-treatments on the function of PEPT2 in healthy subjects, using cephalexin as the probe drug. Sixteen male subjects received a single oral dose of 1000 mg cephalexin under ammonium chloride and sodium bicarbonate treatment, respectively, with a wash-out period of one week. The study subjects were genotyped for PEPT2 polymorphic variants. Cephalexin concentrations in plasma and urine were determined by high performance liquid chromatography. The mean renal clearance of cephalexin was significantly higher under ammonium chloride treatment than that under sodium bicarbonate treatment (P < 0.01). This difference was significant for PEPT2*2/*2 (P = 0.017) but not for PEPT2*1/*1 (P = 0.128). No differences were observed for other pharmacokinetic parameters. The findings of this study suggest that urinary pH changes may alter the pharmacokinetics of PEPT2's substrates. This effect was more obvious for the PEPT2*2/*2.

  19. Removal of As(V), Cr(III) and Cr(VI) from aqueous environments by poly(acrylonitril-co-acrylamidopropyl-trimethyl ammonium chloride)-based hydrogels.

    Science.gov (United States)

    Dudu, Tuba Ersen; Sahiner, Mehtap; Alpaslan, Duygu; Demirci, Sahin; Aktas, Nahit

    2015-09-15

    Cationic poly(Acrylonitril-co-Acrylamidopropyl-trimethyl Ammonium Chloride) (p(AN-co-APTMACl)) hydrogels in bulk were synthesized by using acrylonitrile (AN) and 3-acrylamidopropyl-trimethyl ammonium chloride (APTMACl) as monomers. The prepared hydrogels were exposed to amidoximation reaction to replace hydrophobic nitrile groups with hydrophilic amidoxime groups that have metal ion binding ability. Those replacements were increased the hydrogels absorption capacity for As(V) and Cr(VI). Langmuir and Freundlich isotherms equations were utilized to obtain the best-fitted isotherm model for the absorption of the ions at different metal ion concentrations. The absorption data of As(V) ion were fitted well to Freundlich isotherm while those of Cr(VI) and Cr(III) ions were fitted well to Langmuir isotherm. The maximum absorption of poly(3-acrylamidopropyl-trimethyl ammonium chloride (p(APTMACl)) and amid-p(AN-co-APTMACl) macro gels were 22.39 mg and 21.83 mg for As(V), and 30.65 mg and 18.16 mg for Cr(VI) ion per unit gram dried gel, respectively. Kinetically, the absorption behaviors of Cr(III) and Cr(VI) ions were fitted well to a pseudo 2nd-order kinetic model and those of As(V) ions were fitted well to a pseudo 1st order kinetic model.

  20. Difluoromethylation of O-, S-, N-, C-Nucleophiles Using Difluoromethyltri(n-butyl)ammonium Chloride as a New Difluorocarbene Source%Difluoromethylation of O-, S-, N-, C-Nucleophiles Using Difluoromethyltri(n-butyl)ammonium Chloride as a New Difluorocarbene Source

    Institute of Scientific and Technical Information of China (English)

    王飞; 黄维洲; 胡金波

    2011-01-01

    Difluoromethyltri(n-butyl)ammonium chloride 1 was found to be an effective difluorocarbene reagent for O-, S-, N-, C-difluoromethylation under basic conditions. It is particularly remarkable that, when only 1.2 equivalent of reagent 1 was used, the difluoromethylated products were obtained in moderate to excellent yields.

  1. 'Remote' adiabatic photoinduced deprotonation and aggregate formation of amphiphilic N-alkyl-N-methyl-3-(pyren-1-yl)propan-1-ammonium chloride salts.

    Science.gov (United States)

    Abraham, Shibu; Weiss, Richard G

    2011-11-30

    The absorption and emission properties of a series of amphiphilic N-alkyl-N-methyl-3-(pyren-1-yl)propan-1-ammonium chloride salts were investigated in solvents of different polarities and over a wide concentration range. For example, at 10(-5) M concentrations in tetrahydrofuran (THF), salts with at least one N-H bond exhibited broad, structureless emissions even though time-correlated single photon counting (TCSPC) experiments indicated negligible static or dynamic intermolecular interactions. Salts with a butylene spacer or lacking an N-H bond showed no discernible structureless emission; their emission spectra were dominated by the normal monomeric fluorescence of a pyrenyl group and the TCSPC histograms could be interpreted on the basis of intramolecular photophysics. The broad, structureless emission is attributed to an unprecedented, rapid, adiabatic proton-transfer to the medium, followed by the formation of an intramolecular exciplex consisting of amine and pyrenyl groups. The proposed mechanism involves excitation of a ground-state conformer of the salts in which the ammonium group sits over the pyrenyl ring due to electrostatic stabilization. At higher concentrations, with longer N-alkyl groups, or in selected solvents, electronic excitation of the salts led to dynamic and static excimeric emissions. For example, whereas the emission spectrum of 10(-3) M N-hexyl-N-methyl-3-(pyren-1-yl)propan-1-ammonium chloride in THF consisted of comparable amounts of monomeric and excimeric emission, the emission from 10(-5) M N-dodecyl-N-methyl-3-(pyren-1-yl)propan-1-ammonium chloride in 1:9 (v:v) ethanol/water solutions was dominated by excimeric emission, and discrete particles near micrometer size were discernible from confocal microscopy and dynamic light scattering experiments. Comparison of the static and dynamic emission characteristics of the particles and of the neat solid of N-dodecyl-N-methyl-3-(pyren-1-yl)propan-1-ammonium chloride indicate that molecular

  2. 氯化钙废液回收氯化钙中氯化铵残留的原因分析及解决措施%Calcium Chloride Ammonium Chloride Waste Recycling Calcium Chloride Residual Analysis of the Causes and Solutions

    Institute of Scientific and Technical Information of China (English)

    安彩妹; 李兴波; 陈晓飞; 刘春静

    2015-01-01

    This paper expounds the cyanuric chloride calcium chloride liquid waste recycling process during production. For the reason of recycle calcium chloride ammonium chloride in the residual analysis,determines the final cause of the recovery of calcium chloride ammonium chloride content in the high drying temperature and time are not enough. In neutral pH control 10,reduce enrichment of ammonium chloride in the process of residue. Control in the process of drying temperature of 260 degrees celsius,the calcium chloride wet even after recycling. Control drying time at 24 hours, ammonium chloride content can be calcium chloride content more than 98%,and 0. 05% of the calcium chloride. Reach the standard workshop of calcium chloride recycle,completely solve production using calcium chloride with ammonium chloride and high block of the dryer.%阐述了三聚氯氰生产过程中氯化钙废液的回收工艺。对回收氯化钙中氯化铵的残留进行了原因分析,确定了导致回收氯化钙中氯化铵含量高的最终原因是烘干温度和时间不够。在中和时控制pH值10,减少浓缩过程中氯化铵的残留。在烘干过程中控制温度达到260℃,使回收后氯化钙干湿均匀。控制烘干时间达到24h,可以得到氯化钙含量>98%、氯化铵含量<0.05%的回收氯化钙。达到车间氯化钙循环使用标准,彻底解决生产使用回收氯化钙因氯化铵含量高造成干燥器堵塞的问题。

  3. Chromatographic retention behaviour, modelling and separation optimisation of the quaternary ammonium salt isometamidium chloride and related compounds on a range of reversed-phase liquid chromatographic stationary phases.

    Science.gov (United States)

    Schad, Gesa J; Euerby, Melvin R; Skellern, Graham G; Tettey, Justice N A

    2012-07-01

    This paper describes the reversed-phase liquid chromatographic behaviour of the trypanocidal quaternary ammonium salt isometamidium chloride and its related compounds on a range of liquid chromatographic phases possessing alkyl and phenyl ligands on the same inert silica. In a parallel study with various extended polar selectivity phases which possessed different hydrophobic/silanophilic (hydrogen bonding) activity ratios, the chromatographic retention/selectivities of the quaternary ammonium salts was shown to be due to a co-operative mechanism between hydrophobic and silanophilic interactions. The highly aromatic and planar isometamidium compounds were found to be substantially retained on stationary phases containing aromatic functionality via strong π-π interactions. The chemometric approach of principal component analysis was used to characterise the chromatographic behaviour of the isometamidium compounds on the differing phases and to help identify the dominant retention mechanism(s). Two-dimensional (temperature/gradient) retention modelling was employed to develop and optimise a rapid liquid chromatography method for the separation of the six quaternary ammonium salts within 2.5 min which would be suitable for bioanalysis using liquid chromatography-mass spectrometry. This is the first reported systematic study of the relationship between stationary phase chemistries and retention/selectivity for a group of quaternary ammonium salts.

  4. The toxicity of the quaternary ammonium compound benzalkonium chloride alone and in mixtures with other anionic compounds to bacteria in test systems with Vibrio fischeri and Pseudomonas putida.

    Science.gov (United States)

    Sütterlin, H; Alexy, R; Kümmerer, K

    2008-10-01

    Mixtures of chemicals are present in the aquatic environment but standard testing methods assess only single compounds. One aspect of this question is the importance of the formation of ionic pairs, for example from quaternary ammonium compounds with organic anions, and the significance of the ionic pairs for bacterial toxicity in the aquatic environment. The aim of the present study was to investigate the toxicity of the cationic quaternary ammonium compound benzalkonium chloride (BAC) against aquatic bacteria in the presence of substances commonly found in wastewater, such as the anionic surfactant linear alkylbenzene sulfonate (LAS), naphthalene sulfonic acid (NSA), sodium dodecylsulfonate (SDS), and benzene sulfonic acid (BSA). The growth inhibition test with Pseudomonas putida and the Vibrio fischeri luminescent inhibition test were used to determine the toxicity of single compounds and compound mixtures. The results found in this study indicate that ion pair formation is of minor significance under the test conditions applied here.

  5. 氯化铵对铝酸锶:铕荧光光谱的影响%Effect of Ammonium Chloride on Fluorescence Spectra of Strontium Alunminate:Europium

    Institute of Scientific and Technical Information of China (English)

    李颖毅; 吴燕利; 李永绣

    2011-01-01

    Strontium alunminate: europium is a kind of luminescent material with excellent performance and well application.According to its excitation spectrum, it can match violet light-emitting diode.It has great promise that it will apply to white LED.The luminescent of the material is transformed from green to red by addition of the ammonium chloride, the sharp luminescence peak Eu3+ (f→f) appears.And the composition of the host is improved by addition of the ammonium chloride, and the existence of the Cl- is favorite to the formation of Eu3+.%铝酸锶铕是一种性能优良,应用广泛的荧光材料,它具有绿色长余辉,根据其激发光谱,它能与紫光二极管匹配.氯化铵的添加使发光由绿向红转变,Eu(3+)(f→f)尖峰出现,氯化铵的添加改变其基质组成,Cl(-)的引入有利于Eu(3+)的形成.

  6. N-(2-hydroxyl) propyl-3-trimethyl ammonium chitosan chloride nanoparticle as a novel delivery system for parathyroid hormone-related protein 1-34.

    Science.gov (United States)

    Zhao, Sheng-hao; Wu, Xiao-ting; Guo, Wei-chun; Du, Yu-min; Yu, Ling; Tang, Jin

    2010-06-30

    Chitosan (CS) and epoxy propyl trimethyl ammonium chloride (EPTAC) were used to prepare the water-soluble N-(2-hydroxyl) propyl-3-trimethyl ammonium chitosan chloride (HTCC). HTCC and sodium tripolyphosphate (TPP) were mixed to form HTCC nanoparticles based on ionic gelation. Parathyroid hormone-related protein 1-34 (PTHrP1-34) was incorporated into the HTCC nanoparticles. The particle size and morphology of nanoparticles were determined by transmission electron microscopy (TEM). HTCC/PTHrP1-34 nanoparticles were 100-180 nm in size and their encapsulation efficiency and loading capacity were related to HTCC concentration, TPP concentration and initial concentration of PTHrP1-34. Relatively optimum encapsulation efficiency (78.4%) and loading capacity (13.7%) of PTHrP1-34 is achieved, and the in vitro release profile of PTHrP1-34 from nanoparticles has an initial burst, which is followed up by a slow release phase. These studies showed that HTCC/PTHrP1-34 nanoparticles are suitable for the treatment of osteoporosis, because of their slow-continuous-release properties, and the relevant in vivo experiments and clinical trials should be further studied.

  7. Facile preparation of magnetic 2-hydroxypropyltrimethyl ammonium chloride chitosan/Fe3O4/halloysite nanotubes microspheres for the controlled release of ofloxacin.

    Science.gov (United States)

    Wang, Qin; Zhang, Junping; Mu, Bin; Fan, Ling; Wang, Aiqin

    2014-02-15

    Magnetic microspheres, 2-hydroxypropyltrimethyl ammonium chloride chitosan/Fe3O4/halloysite nanotubes/ofloxacin (HACC/Fe3O4/HNTs/OFL), for the controlled release of OFL were prepared by in situ crosslinking with glutaraldehyde in the spray-drying process. The magnetic microspheres were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis and a magnetometer. Various parameters influencing the encapsulation efficiency, drug loading and in vitro controlled release properties of the magnetic microspheres for OFL were also studied. Many stripes were formed and some tubular HNTs could be seen at higher magnification on the surface of the HACC/Fe3O4/HNTs/OFL magnetic microspheres. The magnetic microspheres show superparamagnetic property and fast magnetic response. The encapsulation efficiency and the cumulative release of OFL are closely related to HACC concentration, HNTs contents and crosslinking density. The release of OFL follows the first-order kinetics.

  8. 碳酸钙-氯化铵烧结法测定真空炼锂炉渣中锂的含量%Determination of Lithium in Slag Refined by Vacuum with Calcium Carbonate and Ammonium Chloride Agglomeration

    Institute of Scientific and Technical Information of China (English)

    李秋霞; 杨猛

    2001-01-01

    研究了利用碳酸钙-氯化铵烧结法测定金属锂真空精炼后炉渣中锂的含量。%Determination of lithium in slag refined by vacuum with calciumcarbonate and ammonium chloride agglomeration was reported.

  9. 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.

  10. 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

  11. Toxicity and genotoxicity of the quaternary ammonium compound benzalkonium chloride (BAC) using Daphnia magna and Ceriodaphnia dubia as model systems.

    Science.gov (United States)

    Lavorgna, Margherita; Russo, Chiara; D'Abrosca, Brigida; Parrella, Alfredo; Isidori, Marina

    2016-03-01

    The toxicity and genotoxicity of the cationic surfactant benzalkonium chloride (BAC) were studied using Daphnia magna and Ceriodaphnia dubia as model systems. Acute and chronic toxicity testing were performed according to the international standard guidelines and the genotoxicity was detected through the comet assay on cells from whole organisms in vivo exposed. Acute effects occurred at concentrations in the order of tens of μg/L in D. magna and hundreds of μg/L in C. dubia. Chronic effects were found at one order of magnitude less than short-term effects maintaining the same difference in sensitivity between D. magna and C. dubia. BAC induced relevant DNA damage, in both cladocerans; the lowest adverse effect levels were 0.4 and 4 ng/L for D. magna and C. dubia, respectively. As these effective concentrations are far lower than BAC occurrence in surface waters (units of μg/L) a concerning environmental risk cannot be excluded. The findings of this study showed that D. magna and C. dubia, could be used as model organisms to detect acute and chronic toxicity as well as genotoxicity at the whole organism level.

  12. The use of superporous p(3-acrylamidopropyl)trimethyl ammonium chloride cryogels for removal of toxic arsenate anions.

    Science.gov (United States)

    Sahiner, Nurettin; Demirci, Sahin; Sahiner, Mehtap; Yilmaz, Selahattin; Al-Lohedan, Hamad

    2015-04-01

    Poly((3-Acrylamidopropyl)trimethylammonium chloride) (p(APTMACl)) cryogels were used as a superporous polymer network for the removal of toxic arsenate anions from an aqueous medium. The fast swelling in water, in about 7 s, was shown to be very useful leading to fast arsenate adsorption by p(APTMACl) cryogels within 30 min in comparison to 12 h for bulk common p(APTMACl) hydrogels. A maximum adsorption capacity of about 120 (mg/g) arsenate was obtained for p(APTMACl) cryogels. Both the Langmuir and Freundlich adsorption isotherms were applied for adsorption of arsenate anions by p(APTMACl) cryogels, and it was observed that the adsorption of arsenate anions by p(APTMACl) cryogels are represented better via Langmuir adsorption isotherm providing the R(2) value of 0.998. Furthermore, mag-p(APTMACl) cryogels were synthesized, and shown to be very useful in the fast removal of toxic arsenate anions. The mag-p(APTMACl) cryogels including the adsorbed arsenate were removed by an externally applied magnetic field, with some reduction in the arsenate ion adsorption capacity. It was also further demonstrated that p(APTMACl) cryogels can be reused in the adsorption of arsenate 5 times from aqueous environments without significant loss of adsorption capacity, from 113.47 ± 9 to 102.67 ± 6 mg/g.

  13. 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.

  14. Column preconcentration of gold by adsorbing AuCl4- onto methyltrioctyl ammonium chloride-naphthalene and subsequent atomic absorption spectrometric determination.

    Science.gov (United States)

    Behpour, M; Attaran, A M; Ghoreishi, S M; Soltani, N

    2005-05-01

    A sensitive, selective and simple preconcentration method for ultra-trace gold determination has been developed that uses naphthalene-methyltrioctyl ammonium chloride (Aliquat 336s) as an adsorbent. Gold, in the form of AuCl4-, was retained by the adsorbent in the column at a flow rate of 1 ml min(-1). After filtration, the solid mass consisting of the gold complex and naphthalene was dissolved out of the column with 5 ml of N,N-dimethylformamide (DMF), and the metal was then determined by atomic absorption spectrometry. In the initial solution, the calibration graph of absorbance versus gold concentration was found to be linear in the range 0.5-150 ng ml(-1) Au(III) with r=0.997 (n=9), and the 3 s detection limit was 0.428 ng ml(-1). The relative standard deviation for eight replicate measurements of 20 microg of gold was 2.14%. Preconcentration factors of 390 and 650 were achieved using 5 ml and 3 ml of DMF, respectively. The proposed method was successfully applied to the determination of gold in wastewater, processed pool water, slurry pool water, and raw well-water from the Moteh gold mine, and synthetic samples.

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. Process for Production of Potassium Sulfate with Potassium Chloride-Ammonium Sulfate Conversion Method%氯化钾-硫酸铵转化法制硫酸钾生产工艺

    Institute of Scientific and Technical Information of China (English)

    赵玉平; 周丽; 李元峰; 靖美萍

    2015-01-01

    简要介绍了氯化钾-硫酸铵转化法制硫酸钾生产工艺及关键设备。该工艺的主产品硫酸钾及副产品氯化铵钾均可在企业内部消化,不仅可优化产品组合,而且降低了外部市场波动对企业经济效益的影响。%The production process and key equipment for production of potassium sulfate with potassium chloride-ammonium sulfate conversion method are briefly introduced.By this process, the main product potassium sulfate and the byproduct potassium ammonium chloride can be digested in the enterprise, it can not only optimize the product structure, but also reduce the influence of external market fluctuations on economic benefits of the enterprise.

  20. 氯化铵处理电石渣制备纳米碳酸钙的实验研究%Experimental Study on Preparation of Nanosized Calcium Carbonate from Carbide Slag Treated by Ammonium Chloride

    Institute of Scientific and Technical Information of China (English)

    张爱华; 朱敏; 关云山; 李晓昆; 张志强; 崔小琴

    2013-01-01

    采用氯化铵对电石渣进行除杂、碳化制备了纳米碳酸钙.优化实验结果表明:干燥温度105℃、pH =8、反应时间1h、氯化铵溶液浓度8%、氯化铵过量程度30%的条件下电石渣收率达92%以上.XRD分析表明产品为方解石,平均晶粒尺寸为38 nm,SEM表明平均颗粒径为80 nm.%The preparation of nanosized calcium carbonate is carried by impurity removal and carbonization of carbide slag treated by ammonium chloride. The optimize experimental results show that carbide slag yield can reach over 92% by controlling drying temperature for 105℃ , pH =8, reaction time for 1 h, concentration of ammonium chloride for 8% and excessive degree of ammonium chloride for 30%. Furthermore, the XRD results showed the production is calcite and the grain average size is 38 nm. And the average particle size in SEM is about 80 nm.

  1. 循环利用氯化铵从氧化铜钴矿中回收铜钴%Recovery of Copper and Cobalt from Oxide Copper-cobalt Ore with Ammonium Chloride

    Institute of Scientific and Technical Information of China (English)

    张明珠; 朱国才

    2012-01-01

    Based on the investigation of roasting oxide copper-cobalt ore with ammonium chloride, leaching, precipitating and recycling ammonium chloride, a new method of recovery of Co and Cu from oxide copper-cobalt ore was proposed to achieve the goal of reducing costs and emission. The results indicate that 90% copper and cobalt are recovered under the optimal condition. Ammonium chloride crystals obtained by cooling and crystallizing of the filtrate are reused for the process. Therefore, the technique achieved highly utilization of oxide copper-cobalt ore under low temperature and less emission.%通过对氯化铵焙烧转化氧化铜钴矿—浸出—沉淀铜钴—氯化铵回收过程的研究,实现氯化铵的循环利用,达到回收富集铜钴及减少排放的目的.试验研究表明:在最佳工艺技术条件下,铜、钴回收率均达90%左右:氯化铵可从饱和的沉淀母液中冷却结晶出来,循环用于氧化铜钴矿的处理.因此,可实现氧化铜钴矿的低温、少废、高效开发利用.

  2. 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.

  3. The cytotoxicity of methacryloxylethyl cetyl ammonium chloride, a cationic antibacterial monomer, is related to oxidative stress and the intrinsic mitochondrial apoptotic pathway.

    Science.gov (United States)

    Ma, Sai; Shan, Le-qun; Xiao, Yu-hong; Li, Fang; Huang, Li; Shen, Lijuan; Chen, Ji-hua

    2011-11-01

    Antibacterial monomers incorporated in dentin bonding systems may have toxic effects on the pulp. Thus, the cytotoxicity of antibacterial monomers and its underlying mechanisms must be elucidated to improve the safety of antibacterial monomer application. The influence of an antibacterial monomer, methacryloxylethyl cetyl ammonium chloride (DMAE-CB), on the vitality of L929 mouse fibroblasts was tested using MTT assay. Cell cycle progression was studied using flow cytometry. Production of intracellular reactive oxygen species (ROS) after DMAE-CB treatment was measured using 2,7-dichlorodihydrofluorescein diacetate staining and flow cytometry analysis. Loss of mitochondrial membrane potential, disturbance of Bcl-2 and Bax expression, as well as release of cytochrome C were also measured using flow cytometry analysis or Western blot to explore the possible involvement of the mitochondrial-related apoptotic pathway. DMAE-CB elicited cell death in a dose-dependent manner and more than 50% of cells were killed after treatment with 30 µM of the monomer. Both necrosis and apoptosis were observed. DMAE-CB also induced G1- and G2-phase arrest. Increased levels of intracellular ROS were observed after 1 h and this overproduction was further enhanced by 6-h treatment with the monomer. DMAE-CB may cause apoptosis by disturbing the expression of Bcl-2 and Bax, reducing the mitochondrial potential and inducing release of cytochrome C. Taken together, these findings suggest that the toxicity of the antibacterial monomer DMAE-CB is associated with ROS production, mitochondrial dysfunction, cell cycle disturbance, and cell apoptosis/necrosis.

  4. 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.

  5. Simplified procedure of ammonium chloride gravimetric analysis%氯化铵重量法分析步骤的简化探讨

    Institute of Scientific and Technical Information of China (English)

    曾旭辉; 黄定策

    2013-01-01

      Using ammonium chloride gravimetric analysis method to test silica content in cement and cement clinker, the procedure could be simplified by minusing two steps——hydrofluoric acid treatment of residue and colorimetric method from leachate recycling leakage silica,according to the standard method. The method is more simple and quick and can reduce error caused by operation miss. In condition of no operation error,the testing result error of the method is less than or equal to 0.2%which can satisfy daily analysis.%  用氯化铵重量法测定水泥及水泥熟料中二氧化硅的含量时,可简化其操作过程,即在标准法的基础上去除用氢氟酸处理残渣和比色法从滤液中回收漏失的二氧化硅这两个步骤。这种方法简单快捷,能减少因操作失误而引起的结果误差,如果能够熟练掌握实验步骤和要点,并在操作无失误的情况下,该法测定的二氧化硅的结果误差都不大于0.2%,能够满足日常分析检验的工作需要。

  6. 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.

  7. 聚甲基丙烯酰氧乙基三甲基氯化铵的合成研究%Study on the synthesis of poly (methacryloxyethyl trimethyl ammonium chloride)

    Institute of Scientific and Technical Information of China (English)

    张彦昌; 王冬梅; 赵献增; 李天仚; 曹金丽; 赵清香

    2013-01-01

    With Methacryloxyethyl trimethyl ammonium chloride as the monomer,Ammonium persulfate and sodium bisulfite as the initiator,Poly( Methacryloxyethyl trimethyl ammonium chloride) (PDMC) was synthesized in the aqueous solution. The effects of Ammonium persulfate, reaction temperature and reaction time on the molecular weight of PDMC were studied by single-factor method. The results indicate that the molecular weight of PDMC increase with the reduce of Ammonium persulfate or longer reaction time; the molecular weight of PDMC increase first and then decrease with rise the reaction temperature,and the PDMC with highest molecular weight was prepared at 75℃.%以甲基丙烯酰氧乙基三甲基氯化铵(DMC)为单体,过硫酸铵/亚硫酸氢钠为引发剂,合成了聚甲基丙烯酰氧乙基三甲基氯化铵(PDMC).单因素法考察了引发剂用量、反应温度以及反应时间对PDMC相对分子质量的影响.实验发现随引发剂用量的减少,PDMC相对分子质量趋于增大;反应温度从65℃升至85℃过程中,PDMC相对分子质量先增大后减小,75℃时,相对分子质量最大;随反应时间的延长,单体残留率逐渐降低,相对分子质量逐渐增大,但超过2h后相对分子质量增大趋缓.

  8. 5-Acetyl-4-(3-hy-droxy-phen-yl)-6-methyl-1,2,3,4-tetra-hydro-pyrimidin-2-one-tris-(hy-droxy-meth-yl)ammonium chloride (2/1).

    Science.gov (United States)

    Huq, C A M A; Fouzia, S; Nizammohideen, M

    2013-11-13

    The asymmetric unit of the title compound, 2C13H14N2O3·C3H10NO3 (+)·Cl(-), contains two independent mol-ecules (A and B) of the title pyrimidine derivative and one ion-pair of tris-(hy-droxy-meth-yl)ammonium chloride. The pyrimidine ring in each pyrimidine derivative has a half-chair conformation. Its mean plane is inclined to the benzene ring by 87.2 (3)° in mol-ecule A and 85.7 (2)° in mol-ecule B. In the crystal, the pyrimidine derivatives are connected to each other by N-H⋯O hydrogen bonds, forming chains propagating along the b-axis direction. The chains are linked via O-H-Cl hydrogen bonds, forming corrugated sheets lying parallel to the bc plane. The sheets are linked via C-H⋯O hydrogen bonds, forming a three-dimensional framework. The tris-(hy-droxy-meth-yl)ammonium chloride mol-ecules are located in the cages of the framework. There are also further C-H⋯O hydrogen bonds and C-H⋯π inter-actions present in the three-dimensional framework structure. Both the cation and chloride anion of the tris-(hy-droxy-meth-yl)ammonium chloride ion pair are disordered over two positions, with a refined occupancy ratio of 0.418 (8):0.582 (8) for the cation and 0.71 (4):0.29 (4) for the anion.

  9. Monolithic spectrometer

    Science.gov (United States)

    Rajic, Slobodan; Egert, Charles M.; Kahl, William K.; Snyder, Jr., William B.; Evans, III, Boyd M.; Marlar, Troy A.; Cunningham, Joseph P.

    1998-01-01

    A monolithic spectrometer is disclosed for use in spectroscopy. The spectrometer is a single body of translucent material with positioned surfaces for the transmission, reflection and spectral analysis of light rays.

  10. 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.

  11. Effects of ammonium concentration and charge exchange on ammonium recovery from high strength wastewater using a microbial fuel cell

    NARCIS (Netherlands)

    Kuntke, P.; Geleij, M.; Bruning, H.; Zeeman, G.; Hamelers, H.V.M.; Buisman, C.J.N.

    2011-01-01

    Ammonium recovery using a 2 chamber microbial fuel cell (MFC) was investigated at high ammonium concentration. Increasing the ammonium concentration (from 0.07 g to 4 g ammonium-nitrogen/L) by addition of ammonium chloride did not affect the performance of the MFC. The obtained current densities by

  12. 超声波对脱气与未脱气氯化铵溶液结晶的影响%Influence of ultrasonic waves on crystallization of ammonium chloride solution and degassed solution

    Institute of Scientific and Technical Information of China (English)

    余德洋; 刘宝林; 吕福扣

    2012-01-01

    In order to clarify the enhancement mechanism of saturated solution crystallization by ultrasound, the effects of ultrasonic waves on crystallization process of saturated ammonium chloride solution and degassed solution are investigated by using a novel ultrasonic cold stage device. The results show that the use of ultrasound could accelerate the crystallization process of both ammonium chloride solution and degassed solution, but the cooling rate and cloudiness time of ammonium chloride solution are much less than those of degassed solution. Furthermore, sonocrystallisation of ammonium chloride solution can result in smaller crystals than those induced by sonocrystallisation of degassed solution. It is concluded that cavitation and fluctuations of density, energy and temperature induced by ultrasound are factors that affect the crystallization process of saturated solutions. But cavitation is a major factor for the enhancement of saturated solution crystallization.%为了阐明超声波强化饱和溶液结晶的机理,分别研究了超声波对脱气饱和氯化铵溶液与未脱气饱和氯化铵溶液结晶的影响.结果显示,在相同超声波辐射下,脱气饱和氯化铵溶液与未脱气饱和氯化铵溶液的结晶均得到了强化,但未脱气饱和氯化铵溶液白浊化开始时间显著小于脱气饱和氯化铵溶液白浊化开始时间,未脱气氯化铵溶液结晶晶粒比脱气氯化铵溶液结晶晶粒更细小.这表明超声空化以及声场中溶液分子振动引起的能量、温度及密度的波动对饱和溶液的结晶均有影响,但空化是强化饱和溶液结晶的主要因素.

  13. Synthesis and Performances of Acrylamide-2-Acrylamido-2-Methylpropanesulfonic Acid-Methacrylic Acid-Diallyl Dimethyl Ammonium Chloride Quadripolymer%AM/AMPS/MAA/DADMAC四元共聚物的合成与性能

    Institute of Scientific and Technical Information of China (English)

    王中华

    2001-01-01

    Acrylamide-2-acrylamido-2-methylpropanesulfonic acid-methacrylic acid-diallyl dimethyl ammonium chloride quadripolymer as drilling-fluid additive was synthesized by redox initation. The mud performances of the quadripolymer was evaluated in the laboratory. The results showed that acrylamide-2-acrylamido-2-methylpropanesulfonic acid-methacrylic acid-diallyl dimethyl ammonium chloride quadripolymer has very good heat resistance,depressing filter loss, salt tolerance, and protection against collapse.%采用氧化-还原引发体系合成丙烯酰胺/2-丙烯酰胺基-2-甲基丙磺酸/甲基丙烯酸/二烯丙基二甲基氯化铵四元共聚物作为钻井液处理剂。初步评价了此四元共聚物的泥浆性能,结果表明,AM/AMPS/MAA/DADMAC四元共聚物具有较好的降滤失和耐温性能,较强的抗盐能力,及较好的防塌效果。

  14. 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.

  15. 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 ...

  16. SYNTHESIS AND APPLICATIONS OF CROSS-LINKED POLY(DIALLYLDIMETHYL AMMONIUM CHLORIDE) AND ITS DERIVATIVE COPOLYMERS AS EFFICIENT PHASE TRANSFER CATALYST FOR NUCLEOPHILIC SUBSTITUTION REACTIONS

    Institute of Scientific and Technical Information of China (English)

    Hossein Mahdavi; Mahdi Mahmoudian

    2011-01-01

    Cross-linked poly(diallyldimethylammonium chloride) and its derivative eopolymers were synthesized and used as phase transfer catalyst in the nucleophilic substitution reaction especially halogen exchange reactions. In addition, the effect of hydrophilic-hydrophobic character of the polymers in the nucleophilic reactions was investigated.

  17. Biodegradation of rocket propellant waste, ammonium perchlorate

    Science.gov (United States)

    Naqvi, S. M. Z.; Latif, A.

    1975-01-01

    The short term effects of ammonium perchlorate on selected organisms were studied. A long term experiment was also designed to assess the changes incurred by ammonium perchlorate on the nitrogen and chloride contents of soil within a period of 3 years. In addition, an attempt was made to produce methane gas from anaerobic fermentation of the aquatic weed, Alternanthera philoxeroides.

  18. 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).

  19. 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.

  20. 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.

  1. Monoliths in Bioprocess Technology

    Directory of Open Access Journals (Sweden)

    Vignesh Rajamanickam

    2015-04-01

    Full Text Available Monolithic columns are a special type of chromatography column, which can be used for the purification of different biomolecules. They have become popular due to their high mass transfer properties and short purification times. Several articles have already discussed monolith manufacturing, as well as monolith characteristics. In contrast, this review focuses on the applied aspect of monoliths and discusses the most relevant biomolecules that can be successfully purified by them. We describe success stories for viruses, nucleic acids and proteins and compare them to conventional purification methods. Furthermore, the advantages of monolithic columns over particle-based resins, as well as the limitations of monoliths are discussed. With a compilation of commercially available monolithic columns, this review aims at serving as a ‘yellow pages’ for bioprocess engineers who face the challenge of purifying a certain biomolecule using monoliths.

  2. Study of the sensitization of tetradecyl benzyl dimethyl ammonium chloride for the color development reaction between lysine and sodium 1,2-naphthoquinone-4-sulfonate and the determination of lysine in pharmaceutical and biological samples

    Science.gov (United States)

    Li, Quanmin; Zhang, Tiantian

    2007-06-01

    A rapid, simple and sensitive method for the determination of lysine (Lys) using sodium 1,2-naphthoquinone-4-sulfonate (NQS) and tetradecyl benzyl dimethyl ammonium chloride (Zeph) is presented in this paper. The method is based on the russety product formed from Lys, NQS and Zeph in a buffer solution of pH 9.60, and the stoichiometric ratio of the product is 1:2:2. Beer's law is obeyed in a range of 0.09-18 μg ml -1 of Lys at the maximum absorption of 474 nm ( ɛ474 is 8.1 × 10 5 l mol -1 cm -1). The equation of linear regression is A = 0.40427 + 0.06112 C, with a linearly correlation coefficient of 0.9972. The limit of detection is 0.07 μg ml -1, R.S.D. 0.8%, and average recovery rate in a range of 98.9-100.1%. This paper further optimizes the determination of Lys compared with the previous methods, and the reaction mechanism is studied intensively. The proposed method has been successfully applied to the determination of Lys in pharmaceutical and biological samples. The common components as nutritional additives in pharmaceuticals and other compounds in biological samples nearly do not interfere with the proposed method.

  3. 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。

  4. Technology Analysis on Co-production of Soda Ash and Ammonium Chloride with Glauber's Brine by Thermal Cycling Method%芒硝型卤水热循环法联产纯碱与氯化铵工艺研究分析

    Institute of Scientific and Technical Information of China (English)

    彭赛军; 彭志成

    2014-01-01

    卤水生产纯碱主要为氨碱法,侯氏联碱法生产纯碱和氯化铵采用固体盐为原料;本文提出新的申请专利技术工艺,采用卤水直接为原料生产纯碱和氯化铵,供同行参考。%Primarily for the production of soda ash with brine is ammonia soda method. Hou's metohd takes solid salt as the raw material to produce soda ash and ammonium chloride. This paper presents a new patented technology process which produce soda ash and ammonium chloride directly with brine as the raw material.

  5. 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.

  6. 5-Acetyl-4-(3-hy­droxy­phen­yl)-6-methyl-1,2,3,4-tetra­hydro­pyrimidin-2-one–tris­(hy­droxy­meth­yl)ammonium chloride (2/1)

    Science.gov (United States)

    Huq, C. A. M. A.; Fouzia, S.; NizamMohideen, M.

    2013-01-01

    The asymmetric unit of the title compound, 2C13H14N2O3·C3H10NO3 +·Cl−, contains two independent mol­ecules (A and B) of the title pyrimidine derivative and one ion-pair of tris­(hy­droxy­meth­yl)ammonium chloride. The pyrimidine ring in each pyrimidine derivative has a half-chair conformation. Its mean plane is inclined to the benzene ring by 87.2 (3)° in mol­ecule A and 85.7 (2)° in mol­ecule B. In the crystal, the pyrimidine derivatives are connected to each other by N—H⋯O hydrogen bonds, forming chains propagating along the b-axis direction. The chains are linked via O—H—Cl hydrogen bonds, forming corrugated sheets lying parallel to the bc plane. The sheets are linked via C—H⋯O hydrogen bonds, forming a three-dimensional framework. The tris­(hy­droxy­meth­yl)ammonium chloride mol­ecules are located in the cages of the framework. There are also further C—H⋯O hydrogen bonds and C—H⋯π inter­actions present in the three-dimensional framework structure. Both the cation and chloride anion of the tris­(hy­droxy­meth­yl)ammonium chloride ion pair are disordered over two positions, with a refined occupancy ratio of 0.418 (8):0.582 (8) for the cation and 0.71 (4):0.29 (4) for the anion. PMID:24454216

  7. 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...

  8. Synthesis and antibacterial activity of bis-[2-hydroxy-3-(1,7,8,9,10-pentamethyl-3,5-dioxo-4-aza-tricyclo[5.2.1.0(2,6)]dec-8-en-4-yloxy)-propyl]-dimethyl-ammonium chloride.

    Science.gov (United States)

    Struga, Marta; Kossakowski, Jerzy; Stefańska, Joanna; Zimniak, Andrzej; Koziol, Anna E

    2008-06-01

    A new quaternary ammonium compound, bis-[2-hydroxy-3-(1,7,8,9,10-pentamethyl-3,5-dioxo-4-aza-tricyclo[5.2.1.0(2,6)]dec-8-en-4-yloxy)-propyl]-dimethyl-ammonium chloride (4), was synthesized. The compound was investigated for antibacterial activity, including Gram-positive cocci and Gram-negative rods, and antifungal activity. Compound 4 showed significant inhibition against Staphylococcus aureus. Research was carried out over 4 standard strains and 40 hospital strains. Elementary analysis and/or MS, (1)H NMR and (13)C NMR spectra confirmed the identity of the products. The molecular structure of 3 was determined by an X-ray analysis.

  9. Ammonium removal from landfill leachate by anodic oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Cabeza, Adelaida [Department of Chemical Engineering, University of Cantabria, Avda. de los Castros s/n. 39005 Santander (Spain); Urtiaga, Ane [Department of Chemical Engineering, University of Cantabria, Avda. de los Castros s/n. 39005 Santander (Spain)]. E-mail: urtiaga@unican.es; Rivero, Maria-Jose [Department of Chemical Engineering, University of Cantabria, Avda. de los Castros s/n. 39005 Santander (Spain); Ortiz, Inmaculada [Department of Chemical Engineering, University of Cantabria, Avda. de los Castros s/n. 39005 Santander (Spain)

    2007-06-18

    The feasibility of removing ammonium from landfill leachates by electrochemical oxidation was studied. Raw leachates and biologically/physico-chemically pretreated leachates from a municipal landfill site were treated. Boron doped diamond was used as anode and stainless steel as cathode, both electrodes with an area of 70 cm{sup 2}. The effects of the applied current density (15-90 mA cm{sup -2}), the initial ammonium concentration (480-2000 mg L{sup -1}), and the initial chloride concentration were experimentally studied. Total ammonium removal was obtained after 360 min of processing and almost half of the initial ammonium nitrogen was oxidized to nitrate. On the other hand, the concentration of chloride enhanced the rate of ammonium oxidation. In addition, the amount of N-NH{sub 4} {sup +} transformed into N-NO{sub 3} {sup -} decreased when additional chloride was provided.

  10. Parameters Affecting Hydrogen Chloride Measurements

    Science.gov (United States)

    1993-06-01

    contain sea salt, which is hygroscopic because of the magnesium chloride present, or ammonium bisulfate , which mostly comes from sulfur pollution and is...boosters release hydrogen chloride as a combustion product, and hydrazines or nitric acid can be spilled from liquid fuel motors. Monitoring the...solubility constant, and the second is the acid ionization constant. From experimental work, the product of the two constants is well established (Reference

  11. 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.

  12. Ammonium sulfate preparation from phosphogypsum waste

    Directory of Open Access Journals (Sweden)

    Abdel-Hakim T. Kandil

    2017-01-01

    Full Text Available The Egyptian phosphogypsum waste is treated using sulfuric acid prior the ammonium sulfate production. The relevant factors that would affect the removal efficiencies of some impurities are studied. The optimum conditions of the treatment are 8 M sulfuric acid solution and 1/4 solid/liquid ratio for 30 min contact time at 80 °C. Moreover, the optimum conditions of the ammonium sulfate preparation are 10 g of the suspended impure or purified phosphogypsum in 40 ml of 3% ammonium sulfate solution (as initiator, 1/4 solid/liquid ratio at pH7 at an addition of an excess ammonium carbonate, and 150 rpm stirring speed for 4.0 h contact time at 55 °C as well as the 5 mg of barium chloride is added to remove the radium in the ammonium sulfate product. Finally, the ammonium sulfate is crystallized and the chemical analysis of the product shows 20% nitrogen and 23.6% sulfur. Therefore, the purity of the obtained ammonium sulfate is 95% from the purified phosphogypsum.

  13. Monolithic microwave integrated circuits

    Science.gov (United States)

    Pucel, R. A.

    Monolithic microwave integrated circuits (MMICs), a new microwave technology which is expected to exert a profound influence on microwave circuit designs for future military systems as well as for the commercial and consumer markets, is discussed. The book contains an historical discussion followed by a comprehensive review presenting the current status in the field. The general topics of the volume are: design considerations, materials and processing considerations, monolithic circuit applications, and CAD, measurement, and packaging techniques. All phases of MMIC technology are covered, from design to testing.

  14. Ammonium chloride as nitrogen source in sugarcane harvested without burning Cloreto de amônio como fonte de nitrogênio em cana-de-açúcar colhida sem queima

    Directory of Open Access Journals (Sweden)

    Michele Xavier Vieira

    2010-08-01

    Full Text Available The great difficulty of incorporation of N fertilizers into the "green sugarcane" system causes concern and since urea is the most commonly used source, there is the risk of loosing NH3 through volatilization. For this reason, a field experiment was undertaken (in a Hapludox Typic with the objective of evaluating the agronomic efficiency of ammonium chloride on stubble of the second ratoon (SP89 1115, as well as its residual effect on the subsequent cycle (third ratoon. The experimental design was randomized blocks with four replications. Treatments consisted of three N rates (60, 120 and 180 kg ha-1 N in the form of NH4Cl, in addition to a control treatment without the addition of N fertilizer. The ratoon cane of the second cutting was harvested in November 2006 and the treatments were applied in December 2006. The second ratoon was harvested mechanically in November 2007 and in December 2007, 450 kg ha-1 of the NPK mixture 20-05-19 was applied, providing 90, 22 and 86 kg ha-1 N, P2O5 and K2O, respectively, for the purpose of evaluating the effect of residual-N from the treatments implanted in December 2006. An increase in the rates of N-NH4Cl had a positive effect on the leaf concentrations of P, Mg and S. Stalk yield (MSS - Mg ha-1 of sugarcane stalks and sugar (MSH - Mg ha-1 of sucrose in the November 2006 harvest responded linearly to the increase of N doses in the form of NH4Cl. In relation to the effect of residual-N in the 2007/2008 harvest, it was observed, in general, that the concentrations of macronutrients in the sugarcane leaf +1 were within the range considered adequate in the state of São Paulo, Brazil. The residual-N of the NH4Cl doses resulted in a significant reduction in stalk (MSS and sugar (MSH production. It may be concluded that the NH4Cl source at a dose of 120 kg ha-1 N in ratoon fertilization of the second cutting was agronomically efficient, presenting, however, less efficiency of residual-N in the subsequent cycle

  15. 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

  16. Insensitive Ammonium Nitrate.

    Science.gov (United States)

    is reduced by replacing the ammonium nitrate with a solid solution of potassium nitrate in form III ammonium nitrate wherein the potassium nitrate...constitutes from more than zero to less than 50 weight percent of the solid solution . (Author)

  17. Embedded-monolith armor

    Science.gov (United States)

    McElfresh, Michael W.; Groves, Scott E; Moffet, Mitchell L.; Martin, Louis P.

    2016-07-19

    A lightweight armor system utilizing a face section having a multiplicity of monoliths embedded in a matrix supported on low density foam. The face section is supported with a strong stiff backing plate. The backing plate is mounted on a spall plate.

  18. 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

  19. Monolithic MACS micro resonators

    Science.gov (United States)

    Lehmann-Horn, J. A.; Jacquinot, J.-F.; Ginefri, J. C.; Bonhomme, C.; Sakellariou, D.

    2016-10-01

    Magic Angle Coil Spinning (MACS) aids improving the intrinsically low NMR sensitivity of heterogeneous microscopic samples. We report on the design and testing of a new type of monolithic 2D MACS resonators to overcome known limitations of conventional micro coils. The resonators' conductors were printed on dielectric substrate and tuned without utilizing lumped element capacitors. Self-resonance conditions have been computed by a hybrid FEM-MoM technique. Preliminary results reported here indicate robust mechanical stability, reduced eddy currents heating and negligible susceptibility effects. The gain in B1 /√{ P } is in agreement with the NMR sensitivity enhancement according to the principle of reciprocity. A sensitivity enhancement larger than 3 has been achieved in a monolithic micro resonator inside a standard 4 mm rotor at 500 MHz. These 2D resonators could offer higher performance micro-detection and ease of use of heterogeneous microscopic substances such as biomedical samples, microscopic specimens and thin film materials.

  20. Elevated ammonium levels

    DEFF Research Database (Denmark)

    Søgaard, Rikke; Novak, Ivana; MacAulay, Nanna

    2012-01-01

    ]glutamate uptake and glutamate transport currents but had no effect on EAAT2. The maximal EAAT3-mediated glutamate transport current was increased but the apparent affinities for glutamate and Na(+) were unaltered. Ammonium did not affect EAAT3-mediated transient currents, indicating that EAAT3 surface expression...... was not enhanced. The ammonium-induced stimulation of EAAT3 increased with increasing extracellular pH, suggesting that the gaseous form NH(3) mediates the effect. An ammonium-induced intracellular alkalinization was excluded as the cause of the enhanced EAAT3 activity because 1) ammonium acidified the oocyte...... cytoplasm, 2) intracellular pH buffering with MOPS did not reduce the stimulation, and 3) ammonium enhanced pH-independent cysteine transport. Our data suggest that the ammonium-elicited uptake stimulation is not caused by intracellular alkalinization or changes in the concentrations of cotransported ions...

  1. Bioaffinity chromatography on monolithic supports

    NARCIS (Netherlands)

    Tetala, K.K.R.; Beek, van T.A.

    2010-01-01

    Affinity chromatography on monolithic supports is a powerful analytical chemical platform because it allows for fast analyses, small sample volumes, strong enrichment of trace biomarkers and applications in microchips. In this review, the recent research using monolithic materials in the field of bi

  2. 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

  3. Design of monoliths through their mechanical properties.

    Science.gov (United States)

    Podgornik, Aleš; Savnik, Aleš; Jančar, Janez; Krajnc, Nika Lendero

    2014-03-14

    Chromatographic monoliths have several interesting properties making them attractive supports for analytics but also for purification, especially of large biomolecules and bioassemblies. Although many of monolith features were thoroughly investigated, there is no data available to predict how monolith mechanical properties affect its chromatographic performance. In this work, we investigated the effect of porosity, pore size and chemical modification on methacrylate monolith compression modulus. While a linear correlation between pore size and compression modulus was found, the effect of porosity was highly exponential. Through these correlations it was concluded that chemical modification affects monolith porosity without changing the monolith skeleton integrity. Mathematical model to describe the change of monolith permeability as a function of monolith compression modulus was derived and successfully validated for monoliths of different geometries and pore sizes. It enables the prediction of pressure drop increase due to monolith compressibility for any monolith structural characteristics, such as geometry, porosity, pore size or mobile phase properties like viscosity or flow rate, based solely on the data of compression modulus and structural data of non-compressed monolith. Furthermore, it enables simple determination of monolith pore size at which monolith compressibility is the smallest and the most robust performance is expected. Data of monolith compression modulus in combination with developed mathematical model can therefore be used for the prediction of monolith permeability during its implementation but also to accelerate the design of novel chromatographic monoliths with desired hydrodynamic properties for particular application.

  4. High surface area, high permeability carbon monoliths

    Energy Technology Data Exchange (ETDEWEB)

    Lagasse, R.R.; Schroeder, J.L. [Sandia National Labs., Albuquerque, NM (United States). Organic Materials Processing Dept.

    1994-12-31

    The goal of this work is to prepare carbon monoliths having precisely tailored pore size distribution. Prior studies have demonstrated that poly(acrylonitrile) can be processed into a precursor having tailored macropore structure. Since the macropores were preserved during pyrolysis, this synthetic process provided a route to porous carbon having macropores with size =0.1 to 10{mu}m. No micropores of size <2 nm could be detected in the carbon, however, by nitrogen adsorption. In the present work, the authors have processed a different polymer, poly(vinylidene chloride) into a macroporous precursor, Pyrolysis produced carbon monoliths having macropores derived from the polymer precursor as well as extensive microporosity produced during the pyrolysis of the polymer. One of these carbons had BET surface area of 1,050 m{sup 2}/g and about 1.2 cc/g total pore volume, with about 1/3 of the total pore volume in micropores and the remainder in 1{mu}m macropores. No mesopores in the intermediate size range could be detected by nitrogen adsorption. Carbon materials having high surface area as well as micron size pores have potential applications as electrodes for double layer supercapacitors containing liquid electrolyte, or as efficient media for performing chemical separations.

  5. 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

  6. Effects of quaternary ammonium silane coatings on mixed fungal and bacterial biofilms on tracheoesophageal shunt prostheses

    NARCIS (Netherlands)

    Oosterhof, JJH; Buijssen, KJDA; Busscher, HJ; van der Laan, BFAM; van der Mei, HC

    2006-01-01

    Two quaternary ammonium silanes (QAS) were used to coat silicone rubber tracheoesophageal shunt prostheses, yielding a positively charged surface. One QAS coating [(trimethoxysilyl)-propyidimethylocta-decylammonium chloride] was applied through chemical bonding, while the other coating, Biocidal ZF,

  7. Porous polymer monolithic col

    Directory of Open Access Journals (Sweden)

    Lydia Terborg

    2015-05-01

    Full Text Available A new approach has been developed for the preparation of mixed-mode stationary phases to separate proteins. The pore surface of monolithic poly(glycidyl methacrylate-co-ethylene dimethacrylate capillary columns was functionalized with thiols and coated with gold nanoparticles. The final mixed mode surface chemistry was formed by attaching, in a single step, alkanethiols, mercaptoalkanoic acids, and their mixtures on the free surface of attached gold nanoparticles. Use of these mixtures allowed fine tuning of the hydrophobic/hydrophilic balance. The amount of attached gold nanoparticles according to thermal gravimetric analysis was 44.8 wt.%. This value together with results of frontal elution enabled calculation of surface coverage with the alkanethiol and mercaptoalkanoic acid ligands. Interestingly, alkanethiols coverage in a range of 4.46–4.51 molecules/nm2 significantly exceeded that of mercaptoalkanoic acids with 2.39–2.45 molecules/nm2. The mixed mode character of these monolithic stationary phases was for the first time demonstrated in the separations of proteins that could be achieved in the same column using gradient elution conditions typical of reverse phase (using gradient of acetonitrile in water and ion exchange chromatographic modes (applying gradient of salt in water, respectively.

  8. Monolithic microchannel heatsink

    Science.gov (United States)

    Benett, William J.; Beach, Raymond J.; Ciarlo, Dino R.

    1996-01-01

    A silicon wafer has slots sawn in it that allow diode laser bars to be mounted in contact with the silicon. Microchannels are etched into the back of the wafer to provide cooling of the diode bars. To facilitate getting the channels close to the diode bars, the channels are rotated from an angle perpendicular to the diode bars which allows increased penetration between the mounted diode bars. This invention enables the fabrication of monolithic silicon microchannel heatsinks for laser diodes. The heatsinks have low thermal resistance because of the close proximity of the microchannels to the laser diode being cooled. This allows high average power operation of two-dimensional laser diode arrays that have a high density of laser diode bars and therefore high optical power density.

  9. Facile preparation of organic-silica hybrid monolith for capillary hydrophilic liquid chromatography based on "thiol-ene" click chemistry.

    Science.gov (United States)

    Chen, Ming-Luan; Zhang, Jun; Zhang, Zheng; Yuan, Bi-Feng; Yu, Qiong-Wei; Feng, Yu-Qi

    2013-04-05

    In this work, a one-step approach to facile preparation of organic-inorganic hybrid monoliths was successfully developed. After vinyl-end organic monomers and azobisisobutyronitrile (AIBN) were mixed with hydrolyzed tetramethoxysilane (TMOS) and 3-mercaptopropyltrimethoxysilane (MPTMS), the homogeneous mixture was introduced into a fused-silica capillary for simultaneous polycondensation and "thiol-ene" click reaction to form the organic-silica hybrid monoliths. By employing this strategy, two types of organic-silica hybrid monoliths with positively charged quaternary ammonium and amide groups were prepared, respectively. The functional groups were successfully introduced onto the monoliths during the sol-gel process with "thiol-ene" click reaction, which was demonstrated by ζ-potential assessment, energy dispersive X-ray spectroscopy (EDX), and Fourier transform infrared (FT-IR) spectroscopy. The porous structure of the prepared monolithic columns was examined by scanning electron microscopy (SEM), nitrogen adsorption-desorption measurement, and mercury intrusion porosimetry. These results indicate the prepared organic-silica hybrid monoliths possess homogeneous column bed, large specific surface area, good mechanical stability, and excellent permeability. The prepared monolithic columns were then applied for anion-exchange/hydrophilic interaction liquid chromatography. Different types of analytes, including benzoic acids, inorganic ions, nucleosides, and nucleotides, were well separated with high column efficiency around 80,000-130,000 plates/m. Taken together, we present a facile and universal strategy to prepare organic-silica hybrid monoliths with a variety of organic monomers using one-step approach.

  10. Detection of di(hydrogentated tallow) alkyl dimethyl ammonium chloride in softening agent using high performance liquid chromatography-mass spectrometry technique%利用高效液相色谱-质谱联用技术测定柔软剂中的二硬化牛油烷基二甲基氯化铵

    Institute of Scientific and Technical Information of China (English)

    周绍强; 吴丽娜; 吴梦笔; 曹锡忠

    2016-01-01

    首次建立利用高效液相色谱-质谱联用技术检测二硬化牛油烷基二甲基氯化铵(DHTDMAC)的方法。经对比选择了高提取效率的甲醇超声提取法,并优化了超声提取的温度、时间;以氨基柱为分析柱,乙酸/甲醇为流动相,在10 min内完成对二硬化牛油烷基二甲基氯化铵的定性、定量分析,结果表明,本法简便、快速、准确、可靠。%High performance liquid chromatography- mass spectrometry technique was established for the first time, which was used for the detection of di(hydrogentated tal ow) alkyl dimethyl ammonium chloride (DHTDMAC). The ultrasonic extraction method with high extraction efficiency was screened as the extraction method, and the temperature and time of ultrasonic extraction were optimized. The qualitative and quantitative analysis of DHTDMAC could be done in 10 min, with amine column as analytical column, acetic acid/methanol as mobile phase in SRM mode. The results showed that this method was simple, rapid, accurate and reliable.

  11. Synthesis and Antibacterial Activity of Novel Quaternary Ammonium Pyridoxine Derivatives.

    Science.gov (United States)

    Shtyrlin, Nikita V; Sapozhnikov, Sergey V; Koshkin, Sergey A; Iksanova, Alfiya G; Sabirov, Arthur H; Kayumov, Airat R; Nureeva, Aliya A; Zeldi, Marina I; Shtyrlin, Yurii G

    2015-01-01

    A series of 26 quaternary ammonium pyridoxine derivatives were synthesized and their cytotoxicity and antibacterial activities against clinically relevant bacterial strains were tested in vitro. The antibacterial activity of mono-ammonium salts increased with the rise of the lipophilicity and compound 3,3,5-trimethyl-8,8-dioctyl-1,7,8,9-tetrahydro-[1,3]dioxino[5,4-d]pyrrolo[3,4-b]pyridin-8-ium chloride (2d) reaches a maximum among them. Bis-ammonium salt of pyridoxine 4 with two dimethyloctylamine groups also demonstrated high antibacterial activity despite lower lipophilicity. The results of MTT assay indicated that HEK 293 cells were more sensitive than HSF to quaternary ammonium pyridoxine derivatives. Compounds 2d and 4 did not induce the damage of the DNA and might be of interest in the development of new antimicrobials.

  12. Novel pretreatment of steam explosion associated with ammonium chloride preimpregnation.

    Science.gov (United States)

    Chen, Hongzhang; Li, Guanhua; Li, Hongqiang

    2014-02-01

    Improving nitrogen content and enhancing enzymatic hydrolysis are key processes involved in cellulosic ethanol production. Steam explosion (SE) associated with NH4Cl preimpregnation was carried out to investigate effects of the pretreatment on nitrogen content, enzymatic digestibility, and ethanol production. Results showed that nitrogen content in pretreated samples increased, which can be used as nitrogen resource for ethanol fermentation. The highest glucose yield of sample pretreated by 1.4MPa SE with 90g/l NH4Cl preimpregnation was 62.64%, which was 2.1 and 0.2 times higher than that of untreated sample and 1.4MPa SE pretreated sample, respectively. Ethanol yield of sample pretreated by 1.1MPa SE with 135g/l NH4Cl preimpregnation resulted in 1.93 and 0.69 times higher than that of untreated sample and 1.1MPa SE pretreated sample, respectively. This novel pretreatment improved nitrogen content and enhanced enzymatic digestibility under mild conditions, and could be recommended to further industrial application.

  13. Experimental study of directional solidification of aqueous ammonium chloride solution

    Science.gov (United States)

    Chen, C. F.; Chen, Falin

    1991-01-01

    Directional solidification experiments have been carried out using the analog casting system of NH4Cl-H2O solution by cooling it from below with a constant-temperature surface ranging from -31.5 C to +11.9 C. The NH4Cl concentration was 26 percent in all solutions, with a liquidus temperature of 15 C. It was found that finger convection occurred in the fluid region just above the mushy layer in all experiments. Plume convection with associated chimneys in the mush occurred in experiments with bottom temperatures as high as +11.0 C. However, when the bottom temperature was raised to +11.9 C, no plume convection was observed, although finger convection continued as usual. A method has been devised to determine the porosity of the mush by computed tomography. Using the mean value of the porosity across the mush layer and the permeability calculated by the Kozeny-Carman relationship, the critical solute Rayleigh number across the mush layer for onset of plume convection was estimated to be between 200 and 250.

  14. Sidebranching in the Dendritic Crystal Growth of Ammonium Chloride

    Science.gov (United States)

    Dougherty, Andrew

    2012-02-01

    We report measurements of the dendritic crystal growth of NH4Cl from supersaturated aqueous solution at small supersaturations. Sidebranch growth in this regime is challenging to model well, and the origin of the sidebranches is not fully understood. The early detection of sidebranches requires measurements of small deviations from the smooth steady state shape, but that shape is not well known at the intermediate distances relevant for sidebranch measurements. One model is that sidebranches result from the selective amplification of microscopic noise. We compare measurements of the sidebranch envelope with predictions of the noise-induced sidebranching model of Gonz'alez-Cinca, Ram'irez-Piscina, Casademunt, and Hern'andez-Machado [Phys Rev. E, 63, 051602 (2001)]. We find that the measured amplitude is somewhat larger than predicted, and the shape of the sidebranch envelope is also different. A second model is that sidebranches result from small oscillations of the tip. We have observed no such oscillations, but very small ones can not be ruled out. No measurement of the tip region can be completely free of contamination from early sidebranches, so it can be challenging to distinguish between an oscillating tip and a smooth tip with sidebranches starting nearby.

  15. In situ sol-gel preparation of porous alumina monoliths for chromatographic separations of adenosine phosphates.

    Science.gov (United States)

    Zajickova, Zuzana; Rubi, Emir; Svec, Frantisek

    2011-06-03

    A method enabling the in situ preparation of porous alumina monoliths within 100 μm i.d. fused silica capillaries has been developed. These monoliths were prepared using the sol-gel process from a mixture consisting of an inorganic aluminum salt, a porogen, an epoxide, and a solvent. We investigated the effects of varying the preparation conditions on the physical characteristics of the monoliths with respect to their potential application in chromatographic separations. The best columns were obtained from a mixture of aluminum chloride hexahydrate, N,N-dimethylformamide, water, ethanol and propylene oxide. Adenosine phosphates were then separated in the optimized column with retention increasing according to number of phosphate functionalities.

  16. The nitrogen Sternheimer antishielding factor in the ammonium ion

    Science.gov (United States)

    Fowler, P. W.; Kelly, H. M.; Brown, R. J. C.

    1993-12-01

    Coupled Hartree-Fock calculations in various basis sets yield values in the range 6.7 to 6.8 for the Sternheimer antishielding factor (1 - γ ∞) of the nitrogen nucleus in the ammonium ion. These are in substantial agreement with the value of 9 that is obtained from a model of measured relaxation times in solid ammonium chloride when allowance is made for effects of the crystalline environment on the chloride ion Sternheimer antishielding factor. Other experimental estimates of the nitrogen Sternheimer factor are discussed. The new value is used to derive cation field gradients from measured quadrupole coupling constants in solid NH 4ReO 4 and NH 4IO 4.

  17. 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.

  18. Chloride transference during electrochemical chloride extraction process

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Chemical titration method and lab-made chloride probes were jointly adopted to investigate the effects of water-to-cement (W/C) ratio and the impressed current density on chloride transport for cement-based materials during electrochemical chloride extraction (ECE) process.The dissolution of bound chlorides and the effect of current density on dissolution were analyzed.The variations of chloride concentration at different depths and the chloride transference process were monitored.Test results show that W/C ratios adopted have slight influence on chloride extraction,while chloride extraction efficiency is mainly determined by the impressed current density.During ECE process a portion of bound chloride ions dissolved and the amount of bound chlorides released is directly proportional to current density.

  19. Rocket Solid Propellant Alternative Based on Ammonium Dinitramide

    Directory of Open Access Journals (Sweden)

    Grigore CICAN

    2017-03-01

    Full Text Available Due to the continuous run for a green environment the current article proposes a new type of solid propellant based on the fairly new synthesized oxidizer, ammonium dinitramide (ADN. Apart of having a higher specific impulse than the worldwide renowned oxidizer, ammonium perchlorate, ADN has the advantage, of leaving behind only nitrogen, oxygen and water after decomposing at high temperatures and therefore totally avoiding the formation of hydrogen chloride fumes. Based on the oxidizer to fuel ratios of the current formulations of the major rocket solid booster (e.g. Space Shuttle’s SRB, Ariane 5’s SRB which comprises mass variations of ammonium perchlorate oxidizer (70-75%, atomized aluminum powder (10-18% and polybutadiene binder (12-20% a new solid propellant was formulated. As previously stated, the new propellant formula and its variations use ADN as oxidizer and erythritol tetranitrate as fuel, keeping the same polybutadiene as binder.

  20. 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.

  1. Feasibility evaluation of the monolithic braided ablative nozzle

    Science.gov (United States)

    Director, Mark N.; McPherson, Douglass J., Sr.

    1992-02-01

    The feasibility of the monolithic braided ablative nozzle was evaluated as part of an independent research and development (IR&D) program complementary to the National Aeronautics and Space Administration/Marshall Space Flight Center (NASA/MSFC) Low-Cost, High-Reliability Case, Insulation and Nozzle for Large Solid Rocket Motors (LOCCIN) Program. The monolithic braided ablative nozzle is a new concept that utilizes a continuous, ablative, monolithic flame surface that extends from the nozzle entrance, through the throat, to the exit plane. The flame surface is fabricated using a Through-the-Thickness braided carbon-fiber preform, which is impregnated with a phenolic or phenolic-like resin. During operation, the braided-carbon fiber/resin material ablates, leaving the structural backside at temperatures which are sufficiently low to preclude the need for any additional insulative materials. The monolithic braided nozzle derives its potential for low life cycle cost through the use of automated processing, one-component fabrication, low material scrap, low process scrap, inexpensive raw materials, and simplified case attachment. It also has the potential for high reliability because its construction prevents delamination, has no nozzle bondlines or leak paths along the flame surface, is amenable to simplified analysis, and is readily inspectable. In addition, the braided construction has inherent toughness and is damage-tolerant. Two static-firing tests were conducted using subscale, 1.8 - 2.0-inch throat diameter, hardware. Tests were approximately 15 seconds in duration, using a conventional 18 percent aluminum/ammonium perchlorate propellant. The first of these tests evaluated the braided ablative as an integral backside insulator and exit cone; the second test evaluated the monolithic braided ablative as an integral entrance/throat/exit cone nozzle. Both tests met their objectives. Radial ablation rates at the throat were as predicted, approximately 0.017 in

  2. 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.

  3. 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%.

  4. 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.

  5. Monolithic Fuel Fabrication Process Development

    Energy Technology Data Exchange (ETDEWEB)

    C. R. Clark; N. P. Hallinan; J. F. Jue; D. D. Keiser; J. M. Wight

    2006-05-01

    The pursuit of a high uranium density research reactor fuel plate has led to monolithic fuel, which possesses the greatest possible uranium density in the fuel region. Process developments in fabrication development include friction stir welding tool geometry and cooling improvements and a reduction in the length of time required to complete the transient liquid phase bonding process. Annealing effects on the microstructures of the U-10Mo foil and friction stir welded aluminum 6061 cladding are also examined.

  6. Pressure drop in CIM disk monolithic columns.

    Science.gov (United States)

    Mihelic, Igor; Nemec, Damjan; Podgornik, Ales; Koloini, Tine

    2005-02-11

    Pressure drop analysis in commercial CIM disk monolithic columns is presented. Experimental measurements of pressure drop are compared to hydrodynamic models usually employed for prediction of pressure drop in packed beds, e.g. free surface model and capillary model applying hydraulic radius concept. However, the comparison between pressure drop in monolith and adequate packed bed give unexpected results. Pressure drop in a CIM disk monolithic column is approximately 50% lower than in an adequate packed bed of spheres having the same hydraulic radius as CIM disk monolith; meaning they both have the same porosity and the same specific surface area. This phenomenon seems to be a consequence of the monolithic porous structure which is quite different in terms of the pore size distribution and parallel pore nonuniformity compared to the one in conventional packed beds. The number of self-similar levels for the CIM monoliths was estimated to be between 1.03 and 2.75.

  7. Graphene-supported metal oxide monolith

    Energy Technology Data Exchange (ETDEWEB)

    Worsley, Marcus A.; Baumann, Theodore F.; Biener, Juergen; Biener, Monika A.; Wang, Yinmin; Ye, Jianchao; Tylski, Elijah

    2017-01-10

    A composition comprising at least one graphene-supported metal oxide monolith, said monolith comprising a three-dimensional structure of graphene sheets crosslinked by covalent carbon bonds, wherein the graphene sheets are coated by at least one metal oxide such as iron oxide or titanium oxide. Also provided is an electrode comprising the aforementioned graphene-supported metal oxide monolith, wherein the electrode can be substantially free of any carbon-black and substantially free of any binder.

  8. Synthesis and structural characterization of polyaniline/cobalt chloride composites

    Science.gov (United States)

    Asha, Goyal, Sneh Lata; Kishore, Nawal

    2016-05-01

    Polyaniline (PANI) and PANI /cobalt chloride composites were synthesized by in situ chemical oxidative polymerization of aniline with CoCl2.6H2O using ammonium peroxidisulphate as an oxidant. These composites were characterized by X-ray diffraction (XRD) and Scanning electron microscopy (SEM). The XRD study reveals that both PANI and composites are amorphous. The XRD and SEM results confirm the presence of cobalt chloride in the composites.

  9. Tribenzylammonium chloride

    Directory of Open Access Journals (Sweden)

    Waly Diallo

    2014-05-01

    Full Text Available Single crystals of the title salt, C21H21NH+·Cl−, were isolated as a side product from the reaction involving [(C6H5CH23NH]2[HPO4] and Sn(CH33Cl in ethanol. Both the cation and the anion are situated on a threefold rotation axis. The central N atom in the cation has a slightly distorted tetrahedral environment, with angles ranging from 107.7 to 111.16 (10°. In the crystal, the tribenzylammonium cations and chloride anions are linked through N—H...Cl and C—H...Cl hydrogen bonds, leading to the formation of infinite chains along [001]. The crystal studied was a merohedral twin.

  10. 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.

  11. Ammonium and potassium removal from swine liquid manure using clinoptilolite, chabazite and faujasite zeolites.

    Science.gov (United States)

    Montégut, Gaëtan; Michelin, Laure; Brendlé, Jocelyne; Lebeau, Bénédicte; Patarin, Joël

    2016-02-01

    This study concerns cationic exchanges performed in order to remove ammonium and potassium cations from manure by using various zeolites: clinoptilolite, chabazite and NaX faujasite. First, the effect of temperature (25 °C and 40 °C) on the exchange rate between zeolites and an ammonium chloride solution was investigated. Then, cationic exchanges were performed on these three zeolites using on one side a mixed ammonium and potassium chloride solution reproducing the chemical composition of a swine manure and on the other side the corresponding liquid manure. No significant difference was observed on the exchange rate and the trapping of ammonium cations by changing the temperature (25 or 40 °C). Clinoptilolite showed a good selectivity towards ammonium cations using model (NH4Cl, and mixed NH4Cl/KCl) solutions but is less efficient with the liquid manure. Chabazite and faujasite were found more efficient than clinoptilolite for trapping ammonium cations. However, NaX faujasite enables trapping 3 times more ammonium cations than chabazite from manure (60 and 20 mg/g, respectively). Moreover, chabazite allowed to trap the same amount of potassium cations than NaX faujasite (33 and 35 mg/g, respectively).

  12. Waterproofing Materials for Ammonium Nitrate

    Directory of Open Access Journals (Sweden)

    R.S. Damse

    2004-10-01

    Full Text Available This study explores the possibility of overcoming the problem of hygroscopicity of ammonium nitrate by coating the particles with selected waterproofing materials. Gravimetric analysis ofthe samples of ammonium nitrate coated with eight different waterproofing materials, vis-a-vis, uncoated ammonium nitrate, were conducted at different relative humidity and exposuretime. The results indicate that mineral jelly is the promising waterproofing material for ammonium nitrate among the materials tested, viz, calcium stearate, dioctyl phthalate, kaoline, diethylphthalate, dinitrotoluene, shelac varnish, and beeswax. Attempts were made to confirm the waterproofing ability of mineral jelly to ammonium nitrate using differential thermal analysisand x-ray diffraction patterns as an experimental tool. Suitability of mineral jelly as an additive for the gun propellant was also assessed on the basis of theoretical calculations using THERMprogram.

  13. Monolithically integrated absolute frequency comb laser system

    Energy Technology Data Exchange (ETDEWEB)

    Wanke, Michael C.

    2016-07-12

    Rather than down-convert optical frequencies, a QCL laser system directly generates a THz frequency comb in a compact monolithically integrated chip that can be locked to an absolute frequency without the need of a frequency-comb synthesizer. The monolithic, absolute frequency comb can provide a THz frequency reference and tool for high-resolution broad band spectroscopy.

  14. Nanosecond monolithic CMOS readout cell

    Science.gov (United States)

    Souchkov, Vitali V.

    2004-08-24

    A pulse shaper is implemented in monolithic CMOS with a delay unit formed of a unity gain buffer. The shaper is formed of a difference amplifier having one input connected directly to an input signal and a second input connected to a delayed input signal through the buffer. An elementary cell is based on the pulse shaper and a timing circuit which gates the output of an integrator connected to the pulse shaper output. A detector readout system is formed of a plurality of elementary cells, each connected to a pixel of a pixel array, or to a microstrip of a plurality of microstrips, or to a detector segment.

  15. Compact monolithic capacitive discharge unit

    Science.gov (United States)

    Roesler, Alexander W.; Vernon, George E.; Hoke, Darren A.; De Marquis, Virginia K.; Harris, Steven M.

    2007-06-26

    A compact monolithic capacitive discharge unit (CDU) is disclosed in which a thyristor switch and a flyback charging circuit are both sandwiched about a ceramic energy storage capacitor. The result is a compact rugged assembly which provides a low-inductance current discharge path. The flyback charging circuit preferably includes a low-temperature co-fired ceramic transformer. The CDU can further include one or more ceramic substrates for enclosing the thyristor switch and for holding various passive components used in the flyback charging circuit. A load such as a detonator can also be attached directly to the CDU.

  16. Ammonium Perchlorate and Ammonium Perchlorate- Hydroxyl Terminated Polybutadiene Simulated Combustion

    Directory of Open Access Journals (Sweden)

    Rene Francisco Boschi Gonçalves

    2012-03-01

    Full Text Available The combustion simulation of ammonium perchlorate was carried out with the software Chemkin, in two steps: the burning behavior of pure ammonium perchlorate and the one of formulated ammonium perchlorate with hydroxyl terminated polybutadiene binder. In both cases, the room pressure varied in order to verify its influence in the system. The burning environment conditions were diverse. During the combustion process, the data obtained from the kinetic chemistry simulation software were compiled. The flame structure can be described by the molar fraction of the burning products and the temperature evolution from the surface of the material.

  17. Microfluidic devices and methods including porous polymer monoliths

    Science.gov (United States)

    Hatch, Anson V; Sommer, Gregory J; Singh, Anup K; Wang, Ying-Chih; Abhyankar, Vinay V

    2014-04-22

    Microfluidic devices and methods including porous polymer monoliths are described. Polymerization techniques may be used to generate porous polymer monoliths having pores defined by a liquid component of a fluid mixture. The fluid mixture may contain iniferters and the resulting porous polymer monolith may include surfaces terminated with iniferter species. Capture molecules may then be grafted to the monolith pores.

  18. Solvothermal removal of the organic template from L{sub 3} ('sponge') templated silica monoliths

    Energy Technology Data Exchange (ETDEWEB)

    Dabbs, Daniel M. [Princeton University, Department of Chemical Engineering (United States); Mulders, Norbert [University of Delaware, Department of Physics and Astronomy (United States); Aksay, Ilhan A. [Princeton University, Department of Chemical Engineering (United States)], E-mail: iaksay@princeton.EDU

    2006-10-15

    We compare the methods of continuous solvent (Soxhlet) and supercritical solvent extractions for the removal of the organic template from nanostructured silica monoliths. Our monoliths are formed by templating the L{sub 3} liquid crystal phase of cetylpyridinium chloride in aqueous solutions with tetramethoxy silane. The monoliths that result from both Soxhlet and supercritical extraction methods are mechanically robust, optically clear, and free of cracks. The Soxhlet method compares favorably with supercritical solvent extraction in that equivalent L{sub 3}-templated silica can be synthesized without the use of specialized reactor hardware or higher temperatures and high pressures, while avoiding noxious byproducts. The comparative effectiveness of various solvents in the Soxhlet process is related to the Hildebrand solubility parameter, determined by the effective surface area of the extracted silica.

  19. Global modeling of nitrate and ammonium aerosols using EQSAM3

    Science.gov (United States)

    Xu, L.; Penner, J. E.

    2009-12-01

    Atmospheric aerosols, particles suspending in air, are important as they affect human health, air quality, and visibility as well as climate. Sulfate, nitrate, ammonium, chloride and sodium are among the most important inorganic aerosol species in the atmosphere. These compounds are hygroscopic and absorb water under almost all ambient environmental conditions. The uptake of water alters the aerosol size, and causes water to become the constituent with the largest atmospheric aerosol mass, especially when the aerosols grow into fog, haze or clouds. Furthermore, several global model studies have demonstrated that rapid increases in nitrogen emissions could produce enough nitrate in aerosols to offset the expected decline in sulfate forcing by 2100 for the extreme IPCC A2 scenario (Bauer et al., 2007). Although nitrate and ammonium were identified as significant anthropogenic sources of aerosols by a number of modeling studies, most global aerosol models still exclude ammonium-nitrate when the direct aerosol forcing is studied. In this study, the computationally efficient equilibrium model, EQSAM3, is incorporated into the UMICH-IMPACT-nitrate model using the hybrid dynamical solution method (Feng and Penner, 2007). The partitioning of nitrate and ammonium along with the corresponding water uptake is evaluated by comparing the model to the EQUISOLVE II method used in Feng and Penner (2007). The model is also evaluated by comparison with the AERONET data base and satellite-based aerosol optical depths.

  20. Monolithic Continuous-Flow Bioreactors

    Science.gov (United States)

    Stephanopoulos, Gregory; Kornfield, Julia A.; Voecks, Gerald A.

    1993-01-01

    Monolithic ceramic matrices containing many small flow passages useful as continuous-flow bioreactors. Ceramic matrix containing passages made by extruding and firing suitable ceramic. Pores in matrix provide attachment medium for film of cells and allow free movement of solution. Material one not toxic to micro-organisms grown in reactor. In reactor, liquid nutrients flow over, and liquid reaction products flow from, cell culture immobilized in one set of channels while oxygen flows to, and gaseous reaction products flow from, culture in adjacent set of passages. Cells live on inner surfaces containing flowing nutrient and in pores of walls of passages. Ready access to nutrients and oxygen in channels. They generate continuous high yield characteristic of immobilized cells, without large expenditure of energy otherwise incurred if necessary to pump nutrient solution through dense biomass as in bioreactors of other types.

  1. Monolithic cells for solar fuels.

    Science.gov (United States)

    Rongé, Jan; Bosserez, Tom; Martel, David; Nervi, Carlo; Boarino, Luca; Taulelle, Francis; Decher, Gero; Bordiga, Silvia; Martens, Johan A

    2014-12-07

    Hybrid energy generation models based on a variety of alternative energy supply technologies are considered the best way to cope with the depletion of fossil energy resources and to limit global warming. One of the currently missing technologies is the mimic of natural photosynthesis to convert carbon dioxide and water into chemical fuel using sunlight. This idea has been around for decades, but artificial photosynthesis of organic molecules is still far away from providing real-world solutions. The scientific challenge is to perform in an efficient way the multi-electron transfer reactions of water oxidation and carbon dioxide reduction using holes and single electrons generated in an illuminated semiconductor. In this tutorial review the design of photoelectrochemical (PEC) cells that combine solar water oxidation and CO2 reduction is discussed. In such PEC cells simultaneous transport and efficient use of light, electrons, protons and molecules has to be managed. It is explained how efficiency can be gained by compartmentalisation of the water oxidation and CO2 reduction processes by proton exchange membranes, and monolithic concepts of artificial leaves and solar membranes are presented. Besides transferring protons from the anode to the cathode compartment the membrane serves as a molecular barrier material to prevent cross-over of oxygen and fuel molecules. Innovative nano-organized multimaterials will be needed to realise practical artificial photosynthesis devices. This review provides an overview of synthesis techniques which could be used to realise monolithic multifunctional membrane-electrode assemblies, such as Layer-by-Layer (LbL) deposition, Atomic Layer Deposition (ALD), and porous silicon (porSi) engineering. Advances in modelling approaches, electrochemical techniques and in situ spectroscopies to characterise overall PEC cell performance are discussed.

  2. Anisotropically structured magnetic aerogel monoliths

    Science.gov (United States)

    Heiligtag, Florian J.; Airaghi Leccardi, Marta J. I.; Erdem, Derya; Süess, Martin J.; Niederberger, Markus

    2014-10-01

    Texturing of magnetic ceramics and composites by aligning and fixing of colloidal particles in a magnetic field is a powerful strategy to induce anisotropic chemical, physical and especially mechanical properties into bulk materials. If porosity could be introduced, anisotropically structured magnetic materials would be the perfect supports for magnetic separations in biotechnology or for magnetic field-assisted chemical reactions. Aerogels, combining high porosity with nanoscale structural features, offer an exceptionally large surface area, but they are difficult to magnetically texture. Here we present the preparation of anatase-magnetite aerogel monoliths via the assembly of preformed nanocrystallites. Different approaches are proposed to produce macroscopic bodies with gradient-like magnetic segmentation or with strongly anisotropic magnetic texture.Texturing of magnetic ceramics and composites by aligning and fixing of colloidal particles in a magnetic field is a powerful strategy to induce anisotropic chemical, physical and especially mechanical properties into bulk materials. If porosity could be introduced, anisotropically structured magnetic materials would be the perfect supports for magnetic separations in biotechnology or for magnetic field-assisted chemical reactions. Aerogels, combining high porosity with nanoscale structural features, offer an exceptionally large surface area, but they are difficult to magnetically texture. Here we present the preparation of anatase-magnetite aerogel monoliths via the assembly of preformed nanocrystallites. Different approaches are proposed to produce macroscopic bodies with gradient-like magnetic segmentation or with strongly anisotropic magnetic texture. Electronic supplementary information (ESI) available: Digital photographs of dispersions and gels with different water-to-ethanol ratios; magnetic measurements of an anatase aerogel containing 0.25 mol% Fe3O4 nanoparticles; XRD patterns of the iron oxide and

  3. 21 CFR 184.1133 - Ammonium alginate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ammonium alginate. 184.1133 Section 184.1133 Food... Specific Substances Affirmed as GRAS § 184.1133 Ammonium alginate. (a) Ammonium alginate (CAS Reg. No. 9005.... Ammonium alginate is prepared by the neutralization of purified alginic acid with appropriate pH...

  4. Monolithic Time Delay Integrated APD Arrays Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The overall goal of the proposed program by Epitaxial Technologies is to develop monolithic time delay integrated avalanche photodiode (APD) arrays with sensitivity...

  5. Monolithic multinozzle emitters for nanoelectrospray mass spectrometry

    Science.gov (United States)

    Wang, Daojing; Yang, Peidong; Kim, Woong; Fan, Rong

    2011-09-20

    Novel and significantly simplified procedures for fabrication of fully integrated nanoelectrospray emitters have been described. For nanofabricated monolithic multinozzle emitters (NM.sup.2 emitters), a bottom up approach using silicon nanowires on a silicon sliver is used. For microfabricated monolithic multinozzle emitters (M.sup.3 emitters), a top down approach using MEMS techniques on silicon wafers is used. The emitters have performance comparable to that of commercially-available silica capillary emitters for nanoelectrospray mass spectrometry.

  6. Benzalkonium chloride. Health hazard evaluation report

    Energy Technology Data Exchange (ETDEWEB)

    Bernholc, N.M.

    1984-01-01

    Health hazards associated with the use of benzalkonium chlorides (BAC) are reviewed. Benzalkonium chloride is extensively used as a cationic disinfectant. It is found in a great many over-the-counter and prescription eye products, disinfectants, shampoos, and deodorants, and is used in concentrations that range from 0.001 to 0.01% in eyedrops, up to 2.5% in concentrated liquid disinfectants. Solutions of 0.03 to 0.04% BAC may cause temporary eye irritation in humans but are unlikely to cause any skin response except in persons allergic to quaternary ammonium compounds. Inhalation of a vaporized 10% solution of BAC produced a bronchospasmodic reaction in a previously sensitized individual. At present no other human health effects from BAC have been documented or inferred from exposure to such dilute concentrations.

  7. Monolithically integrated Ge CMOS laser

    Science.gov (United States)

    Camacho-Aguilera, Rodolfo

    2014-02-01

    Ge-on-Si devices are explored for photonic integration. Through the development of better growth techniques, monolithic integration, laser design and prototypes, it was possible to probe Ge light emitters with emphasis on lasers. Preliminary worked shows thermal photonic behavior capable of enhancing lamination at high temperatures. Increase luminescence is observed up to 120°C from L-band contribution. Higher temperatures show contribution from Δ -band. The increase carrier thermal contribution suggests high temperature applications for Ge light emitters. A Ge electrically pumped laser was probed under 0.2% biaxial strain and doping concentration ~4.5×1019cm-3 n-type. Ge pnn lasers exhibit a gain >1000cm-1 with 8mW power output, presenting a spectrum range of over 200nm, making Ge the ideal candidate for Si photonics. Large temperatures fluctuations and process limit the present device. Theoretically a gain of >4000cm- gain is possible with a threshold of as low as 1kA/cm2. Improvements in Ge work

  8. Fracture resistance of monolithic zirconia molar crowns with reduced thickness

    OpenAIRE

    Nakamura, Keisuke; Harada, A.; Inagaki, R.; Kanno, Taro; Niwano, Y; Milleding, Percy; Ørtengren, Ulf Thore

    2015-01-01

    This is the accepted manuscript version. Published version is available at Acta Odontologica Scandinavica Objectives. The purpose of the present study was to analyze the relationship between fracture load of monolithic zirconia crowns and axial/occlusal thickness, and to evaluate the fracture resistance of monolithic zirconia crowns with reduced thickness in comparison with that of monolithic lithium disilicate crowns with regular thickness. Materials and methods. Monolithic zi...

  9. Modified monolithic silica capillary for preconcentration of catecholamines

    Institute of Scientific and Technical Information of China (English)

    Wei Chang; Tusyo-shi Komazu

    2009-01-01

    Preconcentration of catecholamines by the modified monolithic silica in the capillary was investigated in this study. In order to achieve a microchip-based method for determining catecholamines in the saliva, the monolithic silica was fabricated in the capillary and the monolithic silica was chemically modified by on-column reaction with phenylboronate. Different modified methods were compared. The concentration conditions were optimized. This study indicates the applicability of the modified monolithic silica capillary when it was used to concentrate catecholamines.

  10. Modified monolithic silica capillary for preconcentration of catecholamines

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Preconcentration of catecholamines by the modified monolithic silica in the capillary was investigated in this study. In order to achieve a microchip-based method for determining catecholamines in the saliva,the monolithic silica was fabricated in the capillary and the monolithic silica was chemically modified by on-column reaction with phenylboronate. Different modified methods were compared. The concentration conditions were optimized. This study indicates the applicability of the modified monolithic sili...

  11. Carbon Fiber Composite Monoliths as Catalyst Supports

    Energy Technology Data Exchange (ETDEWEB)

    Contescu, Cristian I [ORNL; Gallego, Nidia C [ORNL; Pickel, Joseph M [ORNL; Blom, Douglas Allen [ORNL; Burchell, Timothy D [ORNL

    2006-01-01

    Carbon fiber composite monoliths are rigid bodies that can be activated to a large surface area, have tunable porosity, and proven performance in gas separation and storage. They are ideal as catalyst supports in applications where a rigid support, with open structure and easy fluid access is desired. We developed a procedure for depositing a dispersed nanoparticulate phase of molybdenum carbide (Mo2C) on carbon composite monoliths in the concentration range of 3 to 15 wt% Mo. The composition and morphology of this phase was characterized using X-ray diffraction and electron microscopy, and a mechanism was suggested for its formation. Molybdenum carbide is known for its catalytic properties that resemble those of platinum group metals, but at a lower cost. The materials obtained are expected to demonstrate catalytic activity in a series of hydrocarbon reactions involving hydrogen transfer. This project demonstrates the potential of carbon fiber composite monoliths as catalyst supports.

  12. Carbon Fiber Composite Monoliths for Catalyst Supports

    Energy Technology Data Exchange (ETDEWEB)

    Contescu, Cristian I [ORNL; Gallego, Nidia C [ORNL; Pickel, Joseph M [ORNL; Blom, Douglas Allen [ORNL; Burchell, Timothy D [ORNL

    2006-01-01

    Carbon fiber composite monoliths are rigid bodies that can be activated to a large surface area, have tunable porosity, and proven performance in gas separation and storage. They are ideal as catalyst supports in applications where a rigid support, with open structure and easy fluid access is desired. We developed a procedure for depositing a dispersed nanoparticulate phase of molybdenum carbide (Mo2C) on carbon composite monoliths in the concentration range of 3 to 15 wt% Mo. The composition and morphology of this phase was characterized using X-ray diffraction and electron microscopy, and a mechanism was suggested for its formation. Molybdenum carbide is known for its catalytic properties that resemble those of platinum group metals, but at a lower cost. The materials obtained are expected to demonstrate catalytic activity in a series of hydrocarbon reactions involving hydrogen transfer. This project demonstrates the potential of carbon fiber composite monoliths as catalyst supports.

  13. Development of a monolithic ferrite memory array

    Science.gov (United States)

    Heckler, C. H., Jr.; Bhiwandker, N. C.

    1972-01-01

    The results of the development and testing of ferrite monolithic memory arrays are presented. This development required the synthesis of ferrite materials having special magnetic and physical characteristics and the development of special processes; (1) for making flexible sheets (laminae) of the ferrite composition, (2) for embedding conductors in ferrite, and (3) bonding ferrite laminae together to form a monolithic structure. Major problems encountered in each of these areas and their solutions are discussed. Twenty-two full-size arrays were fabricated and fired during the development of these processes. The majority of these arrays were tested for their memory characteristics as well as for their physical characteristics and the results are presented. The arrays produced during this program meet the essential goals and demonstrate the feasibility of fabricating monolithic ferrite memory arrays by the processes developed.

  14. Eigenpolarization theory of monolithic nonplanar ring oscillators

    Science.gov (United States)

    Nilsson, Alan C.; Gustafson, Eric K.; Byer, Robert L.

    1989-01-01

    Diode-laser-pumped monolithic nonplanar ring oscillators (NPROs) in an applied magnetic field can operate as unidirectional traveling-wave lasers. The diode laser pumping, monolithic construction, and unidirectional oscillation lead to narrow linewidth radiation. Here, a comprehensive theory of the eigenpolarizations of a monolithic NPRO is presented. It is shown how the properties of the integral optical diode that forces unidirectional operation depend on the choice of the gain medium, the applied magnetic field, the output coupler, and the geometry of the nonplanar ring light path. Using optical equivalence theorems to gain insight into the polarization characteristics of the NPRO, a strategy for designing NPROs with low thresholds and large loss nonreciprocities is given. An analysis of the eigenpolarizations for one such NPRO is presented, alternative optimization approaches are considered, and the prospects for further reducing the linewidths of these lasers are briefly discussed.

  15. 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)...

  16. 76 FR 46907 - Ammonium Nitrate Security Program

    Science.gov (United States)

    2011-08-03

    ... and fertilizer blends containing more than 15% by weight ammonium nitrate, except liquid fertilizers... concerning the detonability of ammonium nitrate; Comments on how likely ammonium nitrate fertilizer users would be to use an alternative fertilizer that is potentially less detonable, such as Sulf-N...

  17. 76 FR 11273 - Ammonium Nitrate From Russia

    Science.gov (United States)

    2011-03-01

    ... COMMISSION Ammonium Nitrate From Russia AGENCY: United States International Trade Commission. ACTION: Institution of a five-year review concerning the suspended investigation on ammonium nitrate from Russia... investigation on ammonium nitrate from Russia would be likely to lead to continuation or recurrence of...

  18. 76 FR 47238 - Ammonium Nitrate From Russia

    Science.gov (United States)

    2011-08-04

    ... COMMISSION Ammonium Nitrate From Russia Determination On the basis of the record \\1\\ developed in the subject... order on ammonium nitrate from Russia would be likely to lead to continuation or recurrence of material... Commission are contained in USITC Publication 4249 (August 2011), entitled Ammonium Nitrate from...

  19. 21 CFR 582.7133 - Ammonium alginate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ammonium alginate. 582.7133 Section 582.7133 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Ammonium alginate. (a) Product. Ammonium alginate. (b) Conditions of use. This substance is...

  20. Physical and chemical sensing using monolithic semiconductor optical transducers

    Science.gov (United States)

    Zappe, Hans P.; Hofstetter, Daniel; Maisenhoelder, Bernd; Moser, Michael; Riel, Peter; Kunz, Rino E.

    1997-09-01

    We present two monolithically integrated optical sensor systems based on semiconductor photonic integrated circuits. These compact, robust and highly functional transducers perform all necessary optical and electro-optical functions on-chip; extension to multi-sensor arrays is easily envisaged. A monolithic Michelson interferometer for high-resolution displacement measurement and a monolithic Mach-Zehnder interferometer for refractometry are discussed.

  1. 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 the state-of-the art: an analytical model which describes chloride profiles in concrete as function of depth...... 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....

  2. Increased thermal conductivity monolithic zeolite structures

    Science.gov (United States)

    Klett, James; Klett, Lynn; Kaufman, Jonathan

    2008-11-25

    A monolith comprises a zeolite, a thermally conductive carbon, and a binder. The zeolite is included in the form of beads, pellets, powders and mixtures thereof. The thermally conductive carbon can be carbon nano-fibers, diamond or graphite which provide thermal conductivities in excess of about 100 W/mK to more than 1,000 W/mK. A method of preparing a zeolite monolith includes the steps of mixing a zeolite dispersion in an aqueous colloidal silica binder with a dispersion of carbon nano-fibers in water followed by dehydration and curing of the binder is given.

  3. Characterization of CIM monoliths as enzyme reactors.

    Science.gov (United States)

    Vodopivec, Martina; Podgornik, Ales; Berovic, Marin; Strancar, Ales

    2003-09-25

    The immobilization of the enzymes citrate lyase, malate dehydrogenase, isocitrate dehydrogenase and lactate dehydrogenase to CIM monolithic supports was performed. The long-term stability, reproducibility, and linear response range of the immobilized enzyme reactors were investigated along with the determination of the kinetic behavior of the enzymes immobilized on the CIM monoliths. The Michaelis-Menten constant K(m) and the turnover number k(3) of the immobilized enzymes were found to be flow-unaffected. Furthermore, the K(m) values of the soluble and immobilized enzyme were found to be comparable. Both facts indicate the absence of a diffusional limitation in immobilized CIM enzyme reactors.

  4. 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 marine atmospheric and submersed South Scandinavian environment. The design parameters are based on sequential measurements of 86 chloride profiles taken over ten years from 13 different types of concrete. The design parameters provide the input for an analytical model for chloride profiles as function...

  5. 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.

  6. 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

  7. 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.

  8. Monolithic Integration of GaN-based LEDs

    Energy Technology Data Exchange (ETDEWEB)

    Ao, Jin-Ping, E-mail: jpao@ee.tokushima-u.ac.jp [Institute of Technology and Science, University of Tokushima 2-1 Minami-Josanjima, Tokushima 770-8506 (Japan)

    2011-02-01

    The technology of monolithically integrated GaN-based light-emitting diodes (LEDs) is reported. First, the technology details to realize monolithic integration are described, including the circuit design for high-voltage and alternating current (AC) operation and the technologies for device isolation. The performances of the fabricated monolithic LED arrays are then demonstrated. A monolithic series array with totally 40 LEDs exhibited expected operation function under AC bias. The operation voltage of the array is 72 V when 20 LEDs were connected in series. Some modified circuit designs for high-voltage operation and other monolithic LED arrays are finally reviewed.

  9. 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.

  10. Granular parakeratosis induced by benzalkonium chloride exposure from laundry rinse aids.

    Science.gov (United States)

    Robinson, Aaron J; Foster, Rachael S; Halbert, Anne R; King, Emma; Orchard, David

    2016-09-19

    Benzalkonium chloride is a quaternary ammonium cationic detergent present in a number of household products, which can act as a major skin irritant. We present the case of six children who developed granular parakeratosis after exposure to benzalkonium chloride in laundry rinse aids, presenting as a brightly erythematous, tender but minimally pruritic, intertriginous eruption followed by superficial desquamation. The eruptions resolved over 3-4 weeks after cessation of exposure.

  11. Synthesis and characterization of chitosan based dye containing quaternary ammonium group.

    Science.gov (United States)

    Tang, Ruilin; Zhang, Ying; Zhang, Yang; Yu, Zhiming

    2016-03-30

    A new antimicrobial biopolymer dye was synthesized by reaction of quaternary ammonium salt of chitosan and reactive red x-3b. And quaternary ammonium salt of chitosan was produced by grafting glycidyltrimethylammonium chloride on chitosan. The synthesized materials were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), solubility test and antimicrobial test. Results show that the antimicrobial biopolymer dye was combined by N(+)(CH3)3 of quaternary ammonium salt of chitosan and sulfonic group of reactive red x-3b. Water solubility of chitosan biopolymer dye was increased as well as pH value. In addition, antibacterial property of new synthesized dye was excellent, whose antibacterial rates of Staphylococcus and Escherichia coli were both bigger than 99%. These results may provide new perspectives on improving the decorative properties and antimicrobial properties in wood industry.

  12. 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.

  13. Synthesis of tetramethyl ammonium hydroxide by cell diaphragm electrolytic method

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Under the conditions of tetramethyl ammonia chloride (TMAC) used as starting material, Ti-based Dimensionally Stable Anode (DSA), stainless steel used as cathode and Nafion 900 cation membrane as cell diaphragm, this paper studies the synthesis of tetramethyl ammonium hydroxide (TMAH) by cell diaphragm electrolytic method, examining not only the effects of current density, concentration of starting material and cell temperature, on the product purity and current efficiency, but also the effects of electrolyte circulation rate on the service life of Ti-based DSA.The experiment puts forward an optimum processing condition, and experimental findings show that preparing TMAH by using this technique can obtain a current efficiency 74.7 % and get product with a purity greater than 99.9%.

  14. Lithium Sulfuryl Chloride Battery.

    Science.gov (United States)

    Primary batteries , Electrochemistry, Ionic current, Electrolytes, Cathodes(Electrolytic cell), Anodes(Electrolytic cell), Thionyl chloride ...Phosphorus compounds, Electrical conductivity, Calibration, Solutions(Mixtures), Electrical resistance, Performance tests, Solvents, Lithium compounds

  15. 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...

  16. Effect of Oxygen Limitation and Starvation on the Benzalkonium Chloride Susceptibility of Escherichia coli

    DEFF Research Database (Denmark)

    Bjergbæk, L.A.; Haagensen, Janus Anders Juul; Molin, Søren

    2008-01-01

    Aims: To investigate the effect of oxygen limitation, glucose-starvation and temperature on the susceptibility of Escherichia coli towards the quaternary ammonium biocide benzalkonium chloride (BAC). Methods and Results: The effect of BAC on planktonic and sessile cells were investigated using...

  17. Effect of spray drying on the properties of amylose-hexadecylammonium chloride inclusion complexes.

    Science.gov (United States)

    Hay, William T; Behle, Robert W; Fanta, George F; Felker, Frederick C; Peterson, Steven C; Selling, Gordon W

    2017-02-10

    Water soluble amylose-hexadecyl ammonium chloride complexes were prepared from high amylose corn starch and hexadecyl ammonium chloride by excess steam jet cooking. Amylose inclusion complexes were spray dried to determine the viability of spray drying as a production method. The variables tested in the spray drying process were the% solids of the amylose-hexadecyl ammonium chloride complex being fed into the spray dryer, feed rate and the spray dryer outlet temperature. The amylose-inclusion complexes remained intact in all spray drying conditions tested as determined by X-ray diffraction. The rheological properties of solutions of the spray dried amylose-complexes remained unchanged when compared with the freeze dried control. Particle density and moisture content decreased with increased outlet temperature while particle size increased. X-ray diffraction and DSC analysis confirmed the formation of type II amylose inclusion complexes. Spray drying is a high throughput, low cost continuous commercial production method, which when coupled with excess steam jet cooking allows for the industrial scale production of cationic amylose-hexadecyl ammonium chloride complexes which may have value as flocculating and filtration enhancing agents and other aspects of paper production.

  18. Monolithic pixel detectors for high energy physics

    CERN Document Server

    Snoeys, W

    2013-01-01

    Monolithic pixel detectors integrating sensor matrix and readout in one piece of silicon have revolutionized imaging for consumer applications, but despite years of research they have not yet been widely adopted for high energy physics. Two major requirements for this application, radiation tolerance and low power consumption, require charge collection by drift for the most extreme radiation levels and an optimization of the collected signal charge over input capacitance ratio ( Q / C ). It is shown that monolithic detectors can achieve Q / C for low analog power consumption and even carryout the promise to practically eliminate analog power consumption, but combining suf fi cient Q / C , collection by drift, and integration of readout circuitry within the pixel remains a challenge. An overview is given of different approaches to address this challenge, with possible advantages and disadvantages.

  19. Macroporous Monolithic Polymers: Preparation and Applications

    Directory of Open Access Journals (Sweden)

    Cecilia Inés Alvarez Igarzabal

    2009-12-01

    Full Text Available In the last years, macroporous monolithic materials have been introduced as a new and useful generation of polymers used in different fields. These polymers may be prepared in a simple way from a homogenous mixture into a mold and contain large interconnected pores or channels allowing for high flow rates at moderate pressures. Due to their porous characteristics, they could be used in different processes, such as stationary phases for different types of chromatography, high-throughput bioreactors and in microfluidic chip applications. This review reports the contributions of several groups working in the preparation of different macroporous monoliths and their modification by immobilization of specific ligands on the products for specific purposes.

  20. A monolithic integrated photonic microwave filter

    Science.gov (United States)

    Fandiño, Javier S.; Muñoz, Pascual; Doménech, David; Capmany, José

    2016-12-01

    Meeting the increasing demand for capacity in wireless networks requires the harnessing of higher regions in the radiofrequency spectrum, reducing cell size, as well as more compact, agile and power-efficient base stations that are capable of smoothly interfacing the radio and fibre segments. Fully functional microwave photonic chips are promising candidates in attempts to meet these goals. In recent years, many integrated microwave photonic chips have been reported in different technologies. To the best of our knowledge, none has monolithically integrated all the main active and passive optoelectronic components. Here, we report the first demonstration of a tunable microwave photonics filter that is monolithically integrated into an indium phosphide chip. The reconfigurable radiofrequency photonic filter includes all the necessary elements (for example, lasers, modulators and photodetectors), and its response can be tuned by means of control electric currents. This is an important step in demonstrating the feasibility of integrated and programmable microwave photonic processors.

  1. Monolithically integrated interferometer for optical displacement measurement

    Science.gov (United States)

    Hofstetter, Daniel; Zappe, Hans P.

    1996-01-01

    We discuss the fabrication of a monolithically integrated optical displacement sensors using III-V semiconductor technology. The device is configured as a Michelson interferometer and consists of a distributed Bragg reflector laser, a photodetector and waveguides forming a directional coupler. Using this interferometer, displacements in the 100 nm range could be measured at distances of up to 45 cm. We present fabrication, device results and characterization of the completed interferometer, problems, limitations and future applications will also be discussed.

  2. FLUIDIZED BED STEAM REFORMER MONOLITH FORMATION

    Energy Technology Data Exchange (ETDEWEB)

    Jantzen, C

    2006-12-22

    Fluidized Bed Steam Reforming (FBSR) is being considered as an alternative technology for the immobilization of a wide variety of aqueous high sodium containing radioactive wastes at various DOE facilities in the United States. The addition of clay, charcoal, and a catalyst as co-reactants converts aqueous Low Activity Wastes (LAW) to a granular or ''mineralized'' waste form while converting organic components to CO{sub 2} and steam, and nitrate/nitrite components, if any, to N{sub 2}. The waste form produced is a multiphase mineral assemblage of Na-Al-Si (NAS) feldspathoid minerals with cage-like structures that atomically bond radionuclides like Tc-99 and anions such as SO{sub 4}, I, F, and Cl. The granular product has been shown to be as durable as LAW glass. Shallow land burial requires that the mineralized waste form be able to sustain the weight of soil overburden and potential intrusion by future generations. The strength requirement necessitates binding the granular product into a monolith. FBSR mineral products were formulated into a variety of monoliths including various cements, Ceramicrete, and hydroceramics. All but one of the nine monoliths tested met the <2g/m{sup 2} durability specification for Na and Re (simulant for Tc-99) when tested using the Product Consistency Test (PCT; ASTM C1285). Of the nine monoliths tested the cements produced with 80-87 wt% FBSR product, the Ceramicrete, and the hydroceramic produced with 83.3 wt% FBSR product, met the compressive strength and durability requirements for an LAW waste form.

  3. Update On Monolithic Fuel Fabrication Development

    Energy Technology Data Exchange (ETDEWEB)

    C. R Clark; J. M. Wight; G. C. Knighton; G. A. Moore; J. F. Jue

    2005-11-01

    Efforts to develop a viable monolithic research reactor fuel plate have continued at Idaho National Laboratory. These efforts have concentrated on both fabrication process refinement and scale-up to produce full sized fuel plates. Advancements have been made in the production of U-Mo foil including full sized foils. Progress has also been made in the friction stir welding and transient liquid phase bonding fabrication processes resulting in better bonding, more stable processes and the ability to fabricate larger fuel plates.

  4. 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.

  5. An overview of monolithic zirconia in dentistry

    Directory of Open Access Journals (Sweden)

    Özlem Malkondu

    2016-07-01

    Full Text Available Zirconia restorations have been used successfully for years in dentistry owing to their biocompatibility and good mechanical properties. Because of their lack of translucency, zirconia cores are generally veneered with porcelain, which makes restorations weaker due to failure of the adhesion between the two materials. In recent years, all-ceramic zirconia restorations have been introduced in the dental sector with the intent to solve this problem. Besides the elimination of chipping, the reduced occlusal space requirement seems to be a clear advantage of monolithic zirconia restorations. However, scientific evidence is needed to recommend this relatively new application for clinical use. This mini-review discusses the current scientific literature on monolithic zirconia restorations. The results of in vitro studies suggested that monolithic zirconia may be the best choice for posterior fixed partial dentures in the presence of high occlusal loads and minimal occlusal restoration space. The results should be supported with much more in vitro and particularly in vivo studies to obtain a final conclusion.

  6. Effect of ammonium sulfate, ammonium chloride and root-zone acidity on inorganic ion content of tobacco

    Science.gov (United States)

    Vessey, J. K.; Raper, C. D. Jr; Henry, L. T.; Raper CD, J. r. (Principal Investigator)

    1990-01-01

    Tobacco plants (Nicotiana tabacum L. cv NC82) were supplied with (NH4)2SO4 or NH4Cl at root-zone pH of 6.0 and 4.5 in hydroponic culture for 28 days. Dry matter accumulation, total N and C content, and leaf area and number were not affected by the NH4+ source or root-zone pH. Plants supplied with NH4Cl accumulated up to 1.2 mM Cl g DW-1, but accumulated 37% less inorganic H2PO4- and 47% less SO4(2-) than plants supplied with (NH4)2SO4. The large Cl- accumulation resulted in NH4Cl- supplied plants having a 31% higher inorganic anion (NO3-, H2, PO4-, SO4(2-), and Cl-) charge. This higher inorganic anion charge in the NH4Cl-supplied plants was balanced by a similar increase in K+ charge. Plants supplied with NH4Cl accumulated greater concentrations of Cl- in leaves (up to 5.1% of DW) than plants supplied with (NH4)2SO4 (less than -% DW). Despite the high Cl- concentration of leaves in NH4Cl supplied plants, these plants showed no symptoms of Cl- toxicity. This demonstrates that toxicity symptoms are not due solely to an interaction between high Cl- concentration in tissue and NH4+ nutrition. The increase in root-zone acidity to pH 4.5 from 6.0 did not induce toxicity symptoms.

  7. 49 CFR 176.410 - Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures. 176.410 Section 176.410 Transportation Other Regulations Relating to... nitrate and ammonium nitrate mixtures. (a) This section prescribes requirements to be observed...

  8. 33 CFR 126.28 - Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate...

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate; general provisions. 126.28 Section 126...) WATERFRONT FACILITIES HANDLING OF DANGEROUS CARGO AT WATERFRONT FACILITIES § 126.28 Ammonium...

  9. Preparation of imprinted monolithic column under molecular crowding conditions

    Institute of Scientific and Technical Information of China (English)

    Xiao Xia Li; Xin Liu; Li Hong Bai; Hong Quan Duan; Yan Ping Huang; Zhao Sheng Liu

    2011-01-01

    Molecular crowding is a new concept to obtain molecularly imprinted polymers (MIPs) with greater capacity and selectivity. In this work, molecular crowding agent was firstly applied to the preparation of MIPs monolithic column. A new polymerization system based on molecular crowding surrounding was developed to prepare enrofloxacin-imprinted monolith, which was composed of polystyrene and tetrahydrofuran. The result showed that the monolithic MIPs under molecular crowding conditions presented good molecular recognition for enrofloxacin with an imprinting factor of 3.03.

  10. 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.

  11. 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.

  12. Equilibrium studies of sodium-ammonium potassium-ammonium, and calcium-ammonium exchanges on clinoptilolite zeolite

    Energy Technology Data Exchange (ETDEWEB)

    Jama, M.A.; Yuecel, H. (Middle East Technical Univ., Ankara (Turkey))

    1989-12-01

    Forward and reverse ion-exchange isotherms for the binary sodium-ammonium, potassium-ammonium, and calcium-ammonium systems on clinoptilolite have been measured in aqueous solutions at a total concentration of 0.1 equiv/dm{sup 3} and at 298 K. Prior to exchange experiments it was attempted to prepare homoionic forms of the zeolite by exhaustive treatments with appropriate salt solutions of cations. With no binary exchanges, full replacement of the cation by the ammonium ion is observed, which conflicts with some earlier work on clinoptilolite. Despite the observed partial exchange levels, clinoptilolite shows a very high preference for ammonium ion over sodium and calcium but not over potassium. Thermodynamic values for the exchanges were calculated and compared with data in the literature. Both the selectivity and thermodynamic affinity sequence, in agreement with previous work reported in the literature, are K{sup +} > NH{sub 4}{sup +} > Na{sup +} > Ca{sup 2+}.

  13. Monolithic Lumped Element Integrated Circuit (M2LEIC) Transistors.

    Science.gov (United States)

    INTEGRATED CIRCUITS, *MONOLITHIC STRUCTURES(ELECTRONICS), *TRANSISTORS, CHIPS(ELECTRONICS), FABRICATION, EPITAXIAL GROWTH, ULTRAHIGH FREQUENCY, POLYSILICONS, PHOTOLITHOGRAPHY, RADIOFREQUENCY POWER, IMPEDANCE MATCHING .

  14. Low-temperature H{sub 2}S removal from steam-containing gas mixtures with ZnO for fuel cell application. 2. Wash-coated monolith

    Energy Technology Data Exchange (ETDEWEB)

    Ivan I. Novochinskii; Chunshan Song; Xiaoliang Ma; Xinsheng Liu; Lawrence Shore; Jordan Lampert; Robert J. Farrauto [Pennsylvania State University, University Park, PA (USA). Clean Fuels and Catalysis Program, Energy Institute and Department of Energy and Geo-Environmental Engineering

    2004-04-01

    This work is part of our efforts to explore more-effective ways to remove hydrogen sulfide (H{sub 2}S) for fuel cell applications. Various absorbents (ZnO, SnO{sub 2}, coprecipitated NiO-MoO{sub 3}, supported CuO-ZnO, V{sub 2}O{sub 5}-ZnO, and ZnO supported on {gamma}-alumina) were tested for H{sub 2}S removal. The absorbents that were wash-coated onto the monolith were compared with particulate traps in the inlet H{sub 2}S concentration range of 0.5-8 parts per million by volume (ppmv). The monolith provides much-higher dynamic capacity (the amount of H{sub 2}S trapped before breakthrough) under the same conditions. The ZnO-based monolith demonstrated the best performance. An extremely low H{sub 2}S outlet concentration (as low as 20 parts per billion, by volume (20 ppbv)) was observed over ZnO-based monolith samples for extended periods of time, under various conditions relevant for the desulfurization of gas products from the autothermal reforming of hydrocarbon fuels for a proton-exchange membrane fuel cell. The capacity of the H{sub 2}S trap is dependent on the monolith characteristics (active component loading per cubic inch, and the number of cells per square inch) and operating conditions (including inlet H{sub 2}S concentration, space velocity, and temperature). Wash-coating of ZnO that was chemically modified by an ammonium carbonate treatment onto a monolith with 400 cells per square inch gave the best H{sub 2}S absorbence with higher dynamic capacity. 9 refs, 5 figs., 5 tabs.

  15. 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...

  16. Selective oxidation of cyclohexene through gold functionalized silica monolith microreactors

    Science.gov (United States)

    Alotaibi, Mohammed T.; Taylor, Martin J.; Liu, Dan; Beaumont, Simon K.; Kyriakou, Georgios

    2016-04-01

    Two simple, reproducible methods of preparing evenly distributed Au nanoparticle containing mesoporous silica monoliths are investigated. These Au nanoparticle containing monoliths are subsequently investigated as flow reactors for the selective oxidation of cyclohexene. In the first strategy, the silica monolith was directly impregnated with Au nanoparticles during the formation of the monolith. The second approach was to pre-functionalize the monolith with thiol groups tethered within the silica mesostructure. These can act as evenly distributed anchors for the Au nanoparticles to be incorporated by flowing a Au nanoparticle solution through the thiol functionalized monolith. Both methods led to successfully achieving even distribution of Au nanoparticles along the length of the monolith as demonstrated by ICP-OES. However, the impregnation method led to strong agglomeration of the Au nanoparticles during subsequent heating steps while the thiol anchoring procedure maintained the nanoparticles in the range of 6.8 ± 1.4 nm. Both Au nanoparticle containing monoliths as well as samples with no Au incorporated were tested for the selective oxidation of cyclohexene under constant flow at 30 °C. The Au free materials were found to be catalytically inactive with Au being the minimum necessary requirement for the reaction to proceed. The impregnated Au-containing monolith was found to be less active than the thiol functionalized Au-containing material, attributable to the low metal surface area of the Au nanoparticles. The reaction on the thiol functionalized Au-containing monolith was found to depend strongly on the type of oxidant used: tert-butyl hydroperoxide (TBHP) was more active than H2O2, likely due to the thiol induced hydrophobicity in the monolith.

  17. Microstructural Evolution of Chloride-Cleaned Silicon Carbide Aluminum Composites

    Science.gov (United States)

    Adeosun, S. O.; Akpan, E. I.; Gbenebor, O. P.; Balogun, S. A.

    2016-02-01

    This study examines the synergy between reinforcement surface modifications on the evolution of microstructures of AA6011-silicon carbide particle (SiCp) composites in multidirectional solidification. Silicon carbide particles (SiCp) were cleaned with ammonium chloride, tin(II) chloride, sodium chloride, and palladium(II) chloride and used as reinforcement to cast AA6011-SiCp composites by applying the stir casting method. A scanning electron microscope and x-ray diffractometer were used to investigate the morphology and phases present, respectively, in the composite material. Results show that wetting agents were effective as they inhibited the formation of Al4C3 in all modified composites. The modified SiCp was found to have varying effects on the morphology, dendrite arm size and direction, size and configuration of AlFeSi, and the amount of eutectic silicon depending on the concentration of the reagent and cleaning time. The highest effect was shown by the use of 40 g/L of tin(II) chloride. The composites had short dendritic arms, good interfacial interaction, and only a few crystals of AlFeSi.

  18. Preparation of graphene/vanadium oxide nanocomposite monolith and its electrochemical performance

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Lingjuan; Ma, Zhanying; Li, Xiaobo; Fan, Guang, E-mail: Chemfang@163.com

    2015-10-15

    Graphical Abstract: Graphene/V{sub 2}O{sub 5}(G/V{sub 2}O{sub 5}) nanocomposite monolith is prepared in a mixture of ammonium vanadate, acetic acid and graphite oxide by one-step hydrothermal technology. Owing to the novel structure of ultralong V{sub 2}O{sub 5} nanobelts interpenetrated between the G nanosheets, the G/V{sub 2}O{sub 5} nanocomposite electrode shows higher specific capacitances and better cycle stability than those of G and V{sub 2}O{sub 5} electrodes for supercapaciors and lithium ion battaries. - Highlights: • G/V{sub 2}O{sub 5} nanocomposite monolith is prepared by one-step hydrothermal technology. • G/V{sub 2}O{sub 5} nanocomposite electrode shows much excellent capacitive property. • G/V{sub 2}O{sub 5} nanocomposite exhibits more stable cycle performance. - Abstract: Graphene/vanadium oxide nanocomposite (G/V{sub 2}O{sub 5}) monolith is prepared via a simple hydrothermal process. Owing to the intimate contact between the V{sub 2}O{sub 5} nanobelts and graphene nanosheets in the monolith, the nanocomposite shows excellent electric conductivity, and therefore makes the electrode–electrolyte contact better and Li{sup +} diffusion faster. A high specific capacitance of 163 F g{sup −1} has been achieved for G/V{sub 2}O{sub 5} electrode in 0.5 mol L{sup −1} K{sub 2}SO{sub 4} solution. The G/V{sub 2}O{sub 5} nanocomposite exhibits excellent cyclic performance with nearly 80% capacity retention at a current density of 5 A g{sup −1} in a testing range of 1000 cycles. Moreover, G/V{sub 2}O{sub 5} nanocomposite exhibits excellent discharge properties and cycle stability as an anode material for lithium ion batteries. The initial capacity is 1100 mAh g{sup −1} and the reversible capacity of 530 mAh g{sup −1} is maintained after 100 cycles at a current density of 50 mA g{sup −1}.

  19. Hydrogel coated monoliths for enzymatic hydrolysis of penicillin G

    NARCIS (Netherlands)

    De Lathouder, K.M.; Smeltink, M.W.; Straathof, A.J.J.; Paasman, M.A.; Van de Sandt, E.J.A.X.; Kapteijn, F.; Moulijn, J.A.

    2008-01-01

    The objective of this work was to develop a hydrogel-coated monolith for the entrapment of penicillin G acylase (E. coli, PGA). After screening of different hydrogels, chitosan was chosen as the carrier material for the preparation of monolithic biocatalysts. This protocol leads to active immobilize

  20. A Monolithic Perovskite Structure for Use as a Magnetic Regenerator

    DEFF Research Database (Denmark)

    Pryds, Nini; Clemens, Frank; Menon, Mohan

    2011-01-01

    A La0.67Ca0.26Sr0.07Mn1.05O3 (LCSM) perovskite was prepared for the first time as a ceramic monolithic regenerator used in a regenerative magnetic refrigeration device. The parameters influencing the extrusion process and the performance of the regenerator, such as the nature of the monolith paste...

  1. Time-based position estimation in monolithic scintillator detectors

    NARCIS (Netherlands)

    Tabacchini, V.; Borghi, G.; Schaart, D.R.

    2015-01-01

    Gamma-ray detectors based on bright monolithic scintillation crystals coupled to pixelated photodetectors are currently being considered for several applications in the medical imaging field. In a typical monolithic detector, both the light intensity and the time of arrival of the earliest scintilla

  2. Energy Absorption of Monolithic and Fibre Reinforced Aluminium Cylinders

    NARCIS (Netherlands)

    De Kanter, J.L.C.G.

    2006-01-01

    Summary accompanying the thesis: Energy Absorption of Monolithic and Fibre Reinforced Aluminium Cylinders by Jens de Kanter This thesis presents the investigation of the crush behaviour of both monolithic aluminium cylinders and externally fibre reinforced aluminium cylinders. The research is based

  3. 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.

  4. Monolithic aerogels with nanoporous crystalline phases

    Science.gov (United States)

    Daniel, Christophe; Guerra, Gaetano

    2015-05-01

    High porosity monolithic aerogels with nanoporous crystalline phases can be obtained from syndiotactic polystyrene and poly(2,6-dimethyl-1,4-phenylene)oxide thermoreversible gels by removing the solvent with supercritical CO2. The presence of crystalline nanopores in the aerogels based on these polymers allows a high uptake associated with a high selectivity of volatile organic compounds from vapor phase or aqueous solutions even at very low activities. The sorption and the fast kinetics make these materials particularly suitable as sorption medium to remove traces of pollutants from water and moist air.

  5. A new large area monolithic silicon telescope

    CERN Document Server

    Tudisco, S; Cabibbo, M; Cardella, G; De Geronimo, G; Di Pietro, A; Fallica, G; Figuera, P; Musumarra, A; Papa, M; Pappalardo, G S; Rizzo, F; Valvo, G

    1999-01-01

    A new prototype of large area (20x20 mm sup 2) monolithic silicon telescope with an ultrathin DELTA E stage (1 mu m) has been built and tested. A particular mask for the ground electrode has been developed to improve the charge collection reducing the induction between the E and DELTA E stages. A special designed preamplifier has been used for the readout of the signal from the DELTA E stage to overcome the problem of the large input capacitance (40 nF). A rather low energy threshold charge discrimination has been obtained. Small side effects due to the electric field deformation near the ground electrode were observed and quantified.

  6. Substrate specificity of Rhbg: ammonium and methyl ammonium transport.

    Science.gov (United States)

    Nakhoul, Nazih L; Abdulnour-Nakhoul, Solange M; Boulpaep, Emile L; Rabon, Edd; Schmidt, Eric; Hamm, L Lee

    2010-09-01

    Rhbg is a nonerythroid membrane glycoprotein belonging to the Rh antigen family. In the kidney, Rhbg is expressed at the basolateral membrane of intercalated cells of the distal nephron and is involved in NH4+ transport. We investigated the substrate specificity of Rhbg by comparing transport of NH3/NH4+ with that of methyl amine (hydrochloride) (MA/MA+), often used to replace NH3/NH4+, in oocytes expressing Rhbg. Methyl amine (HCl) in solution exists as neutral methyl amine (MA) in equilibrium with the protonated methyl ammonium (MA+). To assess transport, we used ion-selective microelectrodes and voltage-clamp experiments to measure NH3/NH4+- and MA/MA+-induced intracellular pH (pH(i)) changes and whole cell currents. Our data showed that in Rhbg oocytes, NH3/NH4+ caused an inward current and decrease in pH(i) consistent with electrogenic NH4+ transport. These changes were significantly larger than in H2O-injected oocytes. The NH3/NH4+-induced current was not inhibited in the presence of barium or in the absence of Na+. In Rhbg oocytes, MA/MA+ caused an inward current but an increase (rather than a decrease) in pH(i). MA/MA+ did not cause any changes in H2O-injected oocytes. The MA/MA+-induced current and pH(i) increase were saturated at higher concentrations of MA/MA+. Amiloride inhibited MA/MA+-induced current and the increase in pH(i) in oocytes expressing Rhbg but had no effect on control oocytes. These results indicate that MA/MA+ is transported by Rhbg but differently than NH3/NH4+. The protonated MA+ is likely a direct substrate whose transport resembles that of NH4+. Transport of electroneutral MA is also enhanced by expression of Rhbg.

  7. 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.

  8. Monolithic columns in plant proteomics and metabolomics.

    Science.gov (United States)

    Rigobello-Masini, Marilda; Penteado, José Carlos Pires; Masini, Jorge Cesar

    2013-03-01

    Since "omics" techniques emerged, plant studies, from biochemistry to ecology, have become more comprehensive. Plant proteomics and metabolomics enable the construction of databases that, with the help of genomics and informatics, show the data obtained as a system. Thus, all the constituents of the system can be seen with their interactions in both space and time. For instance, perturbations in a plant ecosystem as a consequence of application of herbicides or exposure to pollutants can be predicted by using information gathered from these databases. Analytical chemistry has been involved in this scientific evolution. Proteomics and metabolomics are emerging fields that require separation, identification, and quantification of proteins, peptides, and small molecules of metabolites in complex biological samples. The success of this work relies on efficient chromatographic and electrophoretic techniques, and on mass spectrometric detection. This paper reviews recent developments in the use of monolithic columns, focusing on their applications in "top-down" and "bottom-up" approaches, including their use as supports for immobilization of proteolytic enzymes and their use in two-dimensional and multidimensional chromatography. Whereas polymeric columns have been predominantly used for separation of proteins and polypeptides, silica-based monoliths have been more extensively used for separation of small molecules of metabolites. Representative applications in proteomics and in analysis of plant metabolites are given and summarized in tables.

  9. Catastrophic failure of a monolithic zirconia prosthesis.

    Science.gov (United States)

    Chang, Jae-Seung; Ji, Woon; Choi, Chang-Hoon; Kim, Sunjai

    2015-02-01

    Recently, monolithic zirconia restorations have received attention as an alternative to zirconia veneered with feldspathic porcelain to eliminate chipping failures of veneer ceramics. In this clinical report, a patient with mandibular edentulism received 4 dental implants in the interforaminal area, and a screw-retained monolithic zirconia prosthesis was fabricated. The patient also received a maxillary complete removable dental prosthesis over 4 anterior roots. At the 18-month follow-up, all of the zirconia cylinders were seen to be fractured, and the contacting abutment surfaces had lost structural integrity. The damaged abutments were replaced with new abutments, and a new prosthesis was delivered with a computer-assisted design and computer-assisted manufacturing fabricated titanium framework with denture teeth and denture base resins. At the 6-month recall, the patient did not have any problems. Dental zirconia has excellent physical properties; however, care should be taken to prevent excessive stresses on the zirconia cylinders when a screw-retained zirconia restoration is planned as a definitive prosthesis.

  10. Effect of Application of Ammonium Chloride and Calcium Chloride on Alfalfa Cation-Anion Content and Yield

    Science.gov (United States)

    Periparturient hypocalcemia, or milk fever, occurs in dairy cattle when their dietary cation-anion difference (DCAD) is too high. DCAD can be favorably altered to prevent milk fever by either decreasing K and Na or increasing Cl and S in forages for cows in late gestation. The objective of this st...

  11. Persistence of selected ammonium- and phosphonium-based ionic liquids in urban park soil microcosms

    DEFF Research Database (Denmark)

    Sydow, Mateusz; Szczepaniak, Zuzanna; Framski, Grzegorz

    2015-01-01

    Knowledge about biodegradability of ionic liquids (ILs) in terrestrial systems is limited. Here, using urban park soil microcosms spiked with either ammonium- or phosphonium-based ILs [didecyldimethylammonium 3-amino-1,2,4-triazolate, benzalkonium 3-amino-1,2,4-triazolate, trihexyl(tetradecyl)pho......Knowledge about biodegradability of ionic liquids (ILs) in terrestrial systems is limited. Here, using urban park soil microcosms spiked with either ammonium- or phosphonium-based ILs [didecyldimethylammonium 3-amino-1,2,4-triazolate, benzalkonium 3-amino-1,2,4-triazolate, trihexyl......(tetradecyl)phosphonium chloride, or trihexyl(tetradecyl)phosphonium 1,2,4-triazolate], we studied their (i) 300-day primary biodegradation, and (ii) influence on CO2 evolution from the microcosms. The primary biodegradation ranged from 21 to 33% of total compound in the dissolved phase. The evolution of CO2 from spiked...

  12. High durability and low toxicity antimicrobial coatings fabricated by quaternary ammonium silane copolymers.

    Science.gov (United States)

    Li, Hairui; Bao, Hongqian; Bok, Ke Xin; Lee, Chi-Ying; Li, Bo; Zin, Melvin T; Kang, Lifeng

    2016-02-01

    Adhesion and subsequent growth of microorganisms on material surfaces are a major concern in many biomedical applications. Currently, various polymers are immobilized on material surfaces to prevent microbial colonization. However, there are several challenges with regard to the coating materials, including their inability to kill microorganisms, complexity of surface grafting, limited durability and toxicity towards humans. To address these challenges, we synthesize a novel quaternary ammonium silane (QAS) antimicrobial copolymer to confer the antimicrobial effect via a simple thermal-curing coating process. The QAS copolymers were less toxic to 3 human cell lines than a commercial antimicrobial QAS monomeric agent, namely, dimethyloctadecyl[3-(trimethoxysilyl) propyl]ammonium chloride (DTPAC). Moreover, the QAS coatings demonstrated superior antimicrobial efficacy and durability than those of the DTPAC coatings. In conclusion, the novel QAS copolymers are useful to prevent substrates from microbial infections, yet with low toxicity to humans and long durability. In addition, the synthetic process is potentially scalable for industrial applications.

  13. Penicillin analyses by capillary electrochromatography-mass spectrometry with different charged poly(stearyl methacrylate-divinylbenzene) monoliths as stationary phases.

    Science.gov (United States)

    Liu, Wan-Ling; Wu, Ching-Yi; Li, Yi-Ting; Huang, Hsi-Ya

    2012-11-15

    This study describes the ability of an on-line concentration capillary electrochromatography (CEC) coupled with mass spectrometry (MS) for the determination of eight common penicillin antibiotics. Poly(stearyl methacrylate-divinylbenzene) (poly(SMA-DVB)) based monolithic columns prepared under the same conditions but differing only in the charged monomer were used as separation columns. Vinylbenzyl trimethylammonium chloride (VBTA) and vinylbenzenesulfonate (VBSA) were employed as the positively charged monolith and negatively charged monolith, respectively. Results indicated that poly(SMA-DVB-VBTA) monolithic column provided reproducible performance for penicillin separation through ion-exchange interaction, while the negatively charged poly(SMA-DVB-VBSA) column produced unstable separation due to the electrostatic repulsion between the electrophilic analytes and the negatively charged stationary phase. On-line concentration steps of step-gradient elution combined with anion selective injection (ASEI) were used to enhance the detection sensitivity of the CEC-MS method and all penicillin detection sensitivities were further improved (reduction in the limits of detection from 1.9-31 μg/L (normal injection mode) to 0.05-0.2 μg/L (on-line concentration mode)). Finally, this optimal on-line concentration CEC-MS method was applied to trace penicillin analyses in milk samples.

  14. Preparation and Characterization of Temperature-responsive Porous Monoliths

    Institute of Scientific and Technical Information of China (English)

    ZHANG, Rongyue; QI, Li; XIN, Peiyong; YANG, Gengliang; CHEN, Yi

    2009-01-01

    A new temperature-responsive porous monolith has been prepared by surface-initiated activators generated by electron transfer atom transfer radical polymerization (AGET ATRP) grafting poly(N-isopropylacrylamide) (PNIPAAm) within the pores of the porous polymer monolith. The grafting copolymerization was carried out by a method based on a continuous flow-through technique without special deoxygenation procedure needed in the general ATRP. The addition of ascorbic acid could counteract the oxidation effect of oxygen diffusing into the reaction system. The resulting grafted monolith was characterized by a mercury intrusion method and the size of macropore was 3.65 μm, which was suitable for flow through the monolith for HPLC. The thermally responsive property of the grafted monolith was evaluated by HPLC using steroids with various hydrophobicities as probes. Through determination of retention factor of each steroid on the grafted monolith at different temperatures using water as mobile phase, it was found that the slope of the plot of retention factor of each steroid versus the temperature changed around the low critical solution temperature (LCST, 32 ℃) of PNIPAAm in water. It was relative to the grafted PNIPAAm temperature sensitivity that a hydrophobic and hydrophilic alternation would take place around its LCST.Based on this thermally responsive property, the grafted monolith was used as stationary phase for HPLC and to separate the steroids using water as mobile phase by changing the column temperature. As a mobile phase, water is much better than organic solvents concerning the environment.

  15. Influence of different carbon monolith preparation parameters on pesticide adsorption

    Directory of Open Access Journals (Sweden)

    Vukčević Marija

    2013-01-01

    Full Text Available The capacity of carbon monolith for pesticide removal from water, and the mechanism of pesticide interaction with carbon surface were examined. Different carbon monolith samples were obtained by varying the carbonization and activation parameters. In order to examine the role of surface oxygen groups in pesticide adsorption, carbon monolith surface was functionalized by chemical treatment in HNO3, H2O2 and KOH. The surface properties of the obtained samples were investigated by BET surface area, pore size distribution and temperature-programmed desorption. Adsorption of pesticides from aqueous solution onto activated carbon monolith samples was studied by using five pesticides belonging to different chemical groups (acetamiprid, dimethoate, nicosulfuron, carbofuran and atrazine. Presented results show that higher temperature of carbonization and the amount of activating agent allow obtaining microporous carbon monolith with higher amount of surface functional groups. Adsorption properties of the activated carbon monolith were more readily affected by the amount of the surface functional groups than by specific surface area. Results obtained by carbon monolith functionalisation showed that π-π interactions were the main force for adsorption of pesticides with aromatic structure, while acidic groups play an important role in adsorption of pesticides with no aromatic ring in the chemical structure.

  16. 77 FR 65532 - Solid Fertilizer Grade Ammonium Nitrate From the Russian Federation: Notice of Rescission of...

    Science.gov (United States)

    2012-10-29

    ... International Trade Administration Solid Fertilizer Grade Ammonium Nitrate From the Russian Federation: Notice... the antidumping duty order on solid fertilizer grade ammonium nitrate (ammonium nitrate) from the... Administrative Review: Solid Fertilizer Grade Ammonium Nitrate (Ammonium Nitrate) from the Russian...

  17. Benzalkonium Chloride and Glaucoma

    OpenAIRE

    Rasmussen, Carol A.; Kaufman, Paul L.; Kiland, Julie A.

    2014-01-01

    Glaucoma patients routinely take multiple medications, with multiple daily doses, for years or even decades. Benzalkonium chloride (BAK) is the most common preservative in glaucoma medications. BAK has been detected in the trabecular meshwork (TM), corneal endothelium, lens, and retina after topical drop installation and may accumulate in those tissues. There is evidence that BAK causes corneal and conjunctival toxicity, including cell loss, disruption of tight junctions, apoptosis and preapo...

  18. 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)

  19. Hierarchically Structured Monolithic ZSM-5 through Macroporous Silica Gel Zeolitization

    Institute of Scientific and Technical Information of China (English)

    Lei Qian; Zhao Tianbo; Li Fengyan; Zong Baoning; Tong Yangchuan

    2006-01-01

    The hierarchically structured ZSM-5 monolith was prepared through transforming the skeletons of the macroporous silica gel into ZSM-5 by the steam-assisted conversion method. The morphology and monolithic shapes of macroporous silica gel were well preserved. The hierarchically structured ZSM-5 monolith exhibited the hierarchical porosity, with mesopores and macropores existing inside the macroporous silica gel, and micropores formed by the ZSM-5. The products have been characterized properly by using the XRD, SEM and N2 adsorption-desorption methods.

  20. Preparation of carbon monoliths from orange peel for NOx retention

    Directory of Open Access Journals (Sweden)

    Liliana Giraldo

    2014-12-01

    Full Text Available A series of monoliths are prepared from orange peels and chemically activated with H3PO4, KOH, ZnCl2, and water vapor without a binder. The monoliths were characterized by N2 adsorption-desorption isotherms at 77 K, Boehm titrations and XPS. Thereafter, monoliths were tested for their ability to establish NOx retention. The results show that the retention capacities of NOx were a function of the textural properties and chemistries. The carbons synthesized with ZnCl2 and KOH retained similar amounts of NOx.

  1. On monolithic stability and reinforcement analysis of high arch dams

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Monolithic stability safety and reinforcement based on monolithic stability are very important for arch dam design.In this paper,the issue is addressed based on deformation reinforcement theory.In this approach,plastic complementary energy norm can be taken as safety Index for monolithic stability.According to deformation reinforcement theory,the areas where unbalanced force exists require reinforcement,and the required reinforcement forces are just the unbalanced forces with opposite direction.Results show that areas with unbalanced force mainly concentrate in dam-toes,dam-heels and faults.

  2. Preliminary comparison of monolithic and aperture optics for XRMF

    Energy Technology Data Exchange (ETDEWEB)

    Havrilla, G.J.; Worley, C.G.

    1997-08-01

    Comparisons between standard aperture optics and a custom designed monolithic capillary x-ray optic for the Kevex Omicron are presented. The results demonstrate the feasibility of retrofitting an Omicron with a monolithic capillary. Increased flux is observed especially at lower energies which results in an increase in sensitivity and potentially an increase in spatial resolution. Alignment is a critical factor in achieving optimal performance of the monolithic capillary. Further improvements in flux output, spot size and overall sensitivity are expected with better alignment.

  3. A decoupled monolithic projection method for natural convection problems

    Science.gov (United States)

    Pan, Xiaomin; Kim, Kyoungyoun; Lee, Changhoon; Choi, Jung-Il

    2016-06-01

    We propose an efficient monolithic numerical procedure based on a projection method for solving natural convection problems. In the present monolithic method, the buoyancy, linear diffusion, and nonlinear convection terms are implicitly advanced by applying the Crank-Nicolson scheme in time. To avoid an otherwise inevitable iterative procedure in solving the monolithic discretized system, we use a linearization of the nonlinear convection terms and approximate block lower-upper (LU) decompositions along with approximate factorization. Numerical simulations demonstrate that the proposed method is more stable and computationally efficient than other semi-implicit methods, preserving temporal second-order accuracy.

  4. Machining distortion prediction of aerospace monolithic components

    Institute of Scientific and Technical Information of China (English)

    Yun-bo BI; Qun-lin CHENG; Hui-yue DONG; Ying-lin KE

    2009-01-01

    To predict the distortion of aerospace monolithic components.a model is established to simulate the numerical control (NC)milling process using 3D finite element method(FEM).In this model,the cutting layer is simplified firstly.Then,the models of cutting force and cutting temperature are established to gain the cutting loads,which are applied to the mesh model of the part.Finally,a prototype of machining simulation environment is developed to simulate the milling process of a spar.Key factors influencing the distortion,such as initial residual stress,cutting loads,fixture layout,cutting sequence,and tool path are considered all together.The total distortion of the spar is predicted and an experiment is conducted to validate the numerical results.It is found that the maximum discrepancy between the simulation results and experiment values is 19.0%

  5. A monolithic thin film electrochromic window

    Energy Technology Data Exchange (ETDEWEB)

    Goldner, R.B.; Arntz, F.O.; Berera, G.; Haas, T.E.; Wong, K.K. (Tufts Univ., Medford, MA (United States). Electro-Optics Technology Center); Wei, G. (Mobil Solar Energy Corp., Billerica, MA (United States)); Yu, P.C. (PPG Industries, Inc., Monroeville, PA (United States))

    1991-01-01

    Three closely related thin film solid state ionic devices that are potentially important for applications are: electrochromic smart windows, high energy density thin film rechargeable batteries, and thin film electrochemical sensors. Each usually has at least on mixed ion/electron conductor, an electron-blocking ion conductor, and an ion-blocking electron conductor, and many of the technical issues associated with thin film solid state ionics are common to all three devices. Since the electrochromic window has the added technical requirement of electrically-controlled optical modulation, (over the solar spectrum), and since research at the authors' institution has focused primarily on the window structure, this paper will address the electrochromic window, and particularly a monolithic variable reflectivity electrochromic window, as an illustrative example of some of the challenges and opportunities that are confronting the thin film solid state ionics community. 33 refs.

  6. A monolithic thin film electrochromic window

    Energy Technology Data Exchange (ETDEWEB)

    Goldner, R.B.; Arntz, F.O.; Berera, G.; Haas, T.E.; Wong, K.K. [Tufts Univ., Medford, MA (United States). Electro-Optics Technology Center; Wei, G. [Mobil Solar Energy Corp., Billerica, MA (United States); Yu, P.C. [PPG Industries, Inc., Monroeville, PA (United States)

    1991-12-31

    Three closely related thin film solid state ionic devices that are potentially important for applications are: electrochromic smart windows, high energy density thin film rechargeable batteries, and thin film electrochemical sensors. Each usually has at least on mixed ion/electron conductor, an electron-blocking ion conductor, and an ion-blocking electron conductor, and many of the technical issues associated with thin film solid state ionics are common to all three devices. Since the electrochromic window has the added technical requirement of electrically-controlled optical modulation, (over the solar spectrum), and since research at the authors` institution has focused primarily on the window structure, this paper will address the electrochromic window, and particularly a monolithic variable reflectivity electrochromic window, as an illustrative example of some of the challenges and opportunities that are confronting the thin film solid state ionics community. 33 refs.

  7. Monolithically Peltier-cooled laser diodes

    Energy Technology Data Exchange (ETDEWEB)

    Hava, S.; Hunsperger, R.G.; Sequeira, H.B.

    1984-04-01

    A new method of cooling a GaAs/GaAlAs laser in an optical integrated circuit or on a discrete chip, by adding an integral thermoelectric (Peltier) cooling and heat spreading device to the laser, is presented. This cooling both reduces and stabilizes the laser junction temperature to minimize such deleterious effects as wavelength drift due to heating. A unified description of the electrical and thermal properties of a monolithic semiconductor mesa structure is given. Here it is shown that an improvement in thermal characteristics is obtained by depositing a relatively thick metallic layer, and by using this layer as a part of an active Peltier structure. Experimental results reveal a 14-percent increase in emitted power (external quantum efficiency) due to passive heat spreading and a further 8-percent if its Peltier cooler is operated. Fabrication techniques used to obtain devices exhibiting the above performance characteristics are given. 21 references.

  8. LSST primary/tertiary monolithic mirror

    Science.gov (United States)

    Sebag, J.; Gressler, W.; Liang, M.; Neill, D.; Araujo-Hauck, C.; Andrew, J.; Angeli, G.; Cho, M.; Claver, C.; Daruich, F.; Gessner, C.; Hileman, E.; Krabbendam, V.; Muller, G.; Poczulp, G.; Repp, R.; Wiecha, O.; Xin, B.; Kenagy, K.; Martin, H. M.; Tuell, M. T.; West, S. C.

    2016-08-01

    At the core of the Large Synoptic Survey Telescope (LSST) three-mirror optical design is the primary/tertiary (M1M3) mirror that combines these two large mirrors onto one monolithic substrate. The M1M3 mirror was spin cast and polished at the Steward Observatory Mirror Lab at The University of Arizona (formerly SOML, now the Richard F. Caris Mirror Lab at the University of Arizona (RFCML)). Final acceptance of the mirror occurred during the year 2015 and the mirror is now in storage while the mirror cell assembly is being fabricated. The M1M3 mirror will be tested at RFCML after integration with its mirror cell before being shipped to Chile.

  9. Solid oxide fuel cell having monolithic core

    Science.gov (United States)

    Ackerman, J. P.; Young, J. E.

    1983-10-01

    A solid oxide fuel cell is described for electrochemically combining fuel and oxidant for generating galvanic output, wherein the cell core has an array of electrolyte and interconnect walls that are substantially devoid of any composite inert materials for support. The core is monolithic, where each electrolyte wall consists of thin layers of cathode and anode materials sandwiching a thin layer of electrolyte material. The electrolyte walls are arranged and backfolded between adjacent interconnect walls operable to define a plurality of core passageways alternately arranged where the inside faces have only the anode material or only the cathode material exposed. Each layer of the electrolyte and interconnect materials 0.002 to 0.01 cm thick; and each layer of the cathode and anode materials is 0.002 to 0.05 cm thick.

  10. 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.

  11. Screening of L-histidine-based ligands to modify monolithic supports and selectively purify the supercoiled plasmid DNA isoform.

    Science.gov (United States)

    Amorim, Lúcia F A; Sousa, Fani; Queiroz, João A; Cruz, Carla; Sousa, Ângela

    2015-06-01

    The growing demand of pharmaceutical-grade plasmid DNA (pDNA) suitable for biotherapeutic applications fostered the development of new purification strategies. The surface plasmon resonance technique was employed for a fast binding screening of l-histidine and its derivatives, 1-benzyl-L-histidine and 1-methyl-L-histidine, as potential ligands for the biorecognition of three plasmids with different sizes (6.05, 8.70, and 14 kbp). The binding analysis was performed with different isoforms of each plasmid (supercoiled, open circular, and linear) separately. The results revealed that the overall affinity of plasmids to l-histidine and its derivatives was high (KD  > 10(-8)  M), and the highest affinity was found for human papillomavirus 16 E6/E7 (K(D)  = 1.1 × 10(-10)  M and KD  = 3.34 × 10(-10)  M for open circular and linear plasmid isoforms, respectively). L-Histidine and 1-benzyl-L-histidine were immobilized on monolithic matrices. Chromatographic studies of L-histidine and 1-benzyl-L-histidine monoliths were also performed with the aforementioned samples. In general, the supercoiled isoform had strong interactions with both supports. The separation of plasmid isoforms was achieved by decreasing the ammonium sulfate concentration in the eluent, in both supports, but a lower salt concentration was required in the 1-benzyl-L-histidine monolith because of stronger interactions promoted with pDNA. The efficiency of plasmid isoforms separation remained unchanged with flow rate variations. The binding capacity for pDNA achieved with the l-histidine monolith was 29-fold higher than that obtained with conventional L-histidine agarose. Overall, the combination of either L-histidine or its derivatives with monolithic supports can be a promising strategy to purify the supercoiled isoform from different plasmids with suitable purity degree for pharmaceutical applications.

  12. Calcium sulphate in ammonium sulphate solution

    Science.gov (United States)

    Sullivan, E.C.

    1905-01-01

    Calcium sulphate, at 25?? C., is two-thirds as soluble in dilute (o.i mol per liter) and twice as soluble in concentrated (3 mois per liter) ammonium sulphate solution as in water. The specific electric conductivity of concentrated ammonium sulphate solutions is lessened by saturating with calcium sulphate. Assuming that dissociation of ammonium sulphate takes place into 2NH4?? and SO4" and of calcium sulphate into Ca and SO4" only, and that the conductivity is a measure of such dissociation, the solubility of calcium sulphate in dilute ammonium sulphate solutions is greater than required by the mass-law. The conductivity of the dilute mixtures may be accurately calculated by means of Arrhenius' principle of isohydric solutions. In the data obtained in these calculations, the concentration of non-dissociated calcium sulphate decreases with increasing ammonium sulphate. The work as a whole is additional evidence of the fact that we are not yet in possession of all the factors necessary for reconciling the mass-law to the behavior of electrolytes. The measurements above described were made in the chemical laboratory of the University of Michigan.

  13. Monolithic CMOS pixel detector for international linear collider vertex detection

    Indian Academy of Sciences (India)

    J E Brau; O Igonkina; N Sinew; D Strom; C Baltay; W Emmet; H Neal; D Rabinowitz

    2007-12-01

    A monolithic CMS pixel detector is under development for an ILC experiment. This chronopixel array provides a time stamp resolution of one bunch crossing, a critical feature for background suppression. The status of this effort is summarized.

  14. Monolithic Rare Earth Doped PTR Glass Laser Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The main goal of the project is to demonstrate the feasibility of a monolithic solid state laser on the basis of PTR glass co-doped with luminescent rare earth ions....

  15. Plant oil-based shape memory polymer using acrylic monolith

    Directory of Open Access Journals (Sweden)

    T. Tsujimoto

    2015-09-01

    Full Text Available This article deals with the synthesis of a plant oil-based material using acrylic monolith. An acrylic monolith bearing oxirane groups was prepared via simple technique that involved the dissolution of poly(glycidyl methacrylate-comethyl methacrylate (PGMA in ethanolic – aqueous solution by heating and subsequent cooling. The PGMA monolith had topologically porous structure, which was attributed to the phase separation of the polymer solution. The PGMA monolith was impregnated by epoxidized soybean oil (ESO containing thermally-latent catalyst, and the subsequent curing produced a crosslinked material with relatively good transparency. The Young’s modulus and the tensile strength of polyESO/PGMA increased compared with the ESO homopolymer. The strain at break of polyESO/PGMA was larger than that of the ESO homopolymer and crosslinked PGMA. Furthermore, polyESO/PGMA exhibited good shape memory-recovery behavior.

  16. Synthesis, spectroscopic and thermal studies of the copper(II) aspartame chloride complex

    Science.gov (United States)

    Çakır, S.; Coşkun, E.; Naumov, P.; Biçer, E.; Bulut, İ.; İçbudak, H.; Çakır, O.

    2002-08-01

    Aspartame adduct of copper(II) chloride Cu(Asp) 2Cl 2·2H 2O (Asp=aspartame) is synthesized and characterized by elemental analysis, FT IR, UV/vis, ESR spectroscopies, TG, DTG, DTA measurements and molecular mechanics calculations. Aqueous solution of the green solid absorbs strongly at 774 and 367 nm. According to the FT IR spectra, the aspartame moiety coordinates to the copper(II) ion via its carboxylate ends, whereas the ammonium terminal groups give rise to hydrogen bonding network with the water, the chloride ions or neighboring carboxylate groups. The results suggest tetragonally distorted octahedral environment of the copper ions.

  17. Reliability Analysis and Optimal Design of Monolithic Vertical Wall Breakwaters

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Burcharth, Hans F.; Christiani, E.

    1994-01-01

    Reliability analysis and reliability-based design of monolithic vertical wall breakwaters are considered. Probabilistic models of the most important failure modes, sliding failure, failure of the foundation and overturning failure are described . Relevant design variables are identified and relia......Reliability analysis and reliability-based design of monolithic vertical wall breakwaters are considered. Probabilistic models of the most important failure modes, sliding failure, failure of the foundation and overturning failure are described . Relevant design variables are identified...

  18. Sol-Gel Synthesis of Non-Silica Monolithic Materials

    Directory of Open Access Journals (Sweden)

    Bartłomiej Gaweł

    2010-04-01

    Full Text Available Monolithic materials have become very popular because of various applications, especially within chromatography and catalysis. Large surface areas and multimodal porosities are great advantages for these applications. New sol-gel preparation methods utilizing phase separation or nanocasting have opened the possibility for preparing materials of other oxides than silica. In this review, we present different synthesis methods for inorganic, non-silica monolithic materials. Some examples of application of the materials are also included.

  19. Extended Leach Testing of Simulated LAW Cast Stone Monoliths

    Energy Technology Data Exchange (ETDEWEB)

    Serne, R. Jeffrey [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Westsik, Joseph H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Williams, Benjamin D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Jung, H. B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wang, Guohui [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-07-09

    This report describes the results from long-term laboratory leach tests performed at Pacific Northwest National Laboratory (PNNL) for Washington River Protection Solutions (WRPS) to evaluate the release of key constituents from monoliths of Cast Stone prepared with four simulated low-activity waste (LAW) liquid waste streams. Specific objectives of the Cast Stone long-term leach tests described in this report focused on four activities: 1. Extending the leaching times for selected ongoing EPA-1315 tests on monoliths made with LAW simulants beyond the conventional 63-day time period up to 609 days reported herein (with some tests continuing that will be documented later) in an effort to evaluate long-term leaching properties of Cast Stone to support future performance assessment activities. 2. Starting new EPA-1315 leach tests on archived Cast Stone monoliths made with four LAW simulants using two leachants (deionized water [DIW] and simulated Hanford Integrated Disposal Facility (IDF) Site vadose zone pore water [VZP]). 3. Evaluating the impacts of varying the iodide loading (starting iodide concentrations) in one LAW simulant (7.8 M Na Hanford Tank Waste Operations Simulator (HTWOS) Average) by manufacturing new Cast Stone monoliths and repeating the EPA-1315 leach tests using DIW and the VZP leachants. 4. Evaluating the impacts of using a non-pertechnetate form of Tc that is present in some Hanford tanks. In this activity one LAW simulant (7.8 M Na HTWOS Average) was spiked with a Tc(I)-tricarbonyl gluconate species and then solidified into Cast Stone monoliths. Cured monoliths were leached using the EPA-1315 leach protocol with DIW and VZP. The leach results for the Tc-Gluconate Cast Stone monoliths were compared to Cast Stone monoliths pertechnetate.

  20. 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

  1. 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%.

  2. Mechanically stable, hierarchically porous Cu3(btc)2 (HKUST-1) monoliths via direct conversion of copper(II) hydroxide-based monoliths.

    Science.gov (United States)

    Moitra, Nirmalya; Fukumoto, Shotaro; Reboul, Julien; Sumida, Kenji; Zhu, Yang; Nakanishi, Kazuki; Furukawa, Shuhei; Kitagawa, Susumu; Kanamori, Kazuyoshi

    2015-02-28

    The synthesis of highly crystalline macro-meso-microporous monolithic Cu3(btc)2 (HKUST-1; btc(3-) = benzene-1,3,5-tricarboxylate) is demonstrated by direct conversion of Cu(OH)2-based monoliths while preserving the characteristic macroporous structure. The high mechanical strength of the monoliths is promising for possible applications to continuous flow reactors.

  3. Oxomemazine hydro-chloride.

    Science.gov (United States)

    Siddegowda, M S; Butcher, Ray J; Akkurt, Mehmet; Yathirajan, H S; Ramesh, A R

    2011-08-01

    IN THE TITLE COMPOUND [SYSTEMATIC NAME: 3-(5,5-dioxo-phen-othia-zin-10-yl)-N,N,2-trimethyl-propanaminium chloride], C(18)H(23)N(2)O(2)S(+)·Cl(-), the dihedral angle between the two outer aromatic rings of the phenothia-zine unit is 30.5 (2)°. In the crystal, the components are linked by N-H⋯Cl and C-H⋯Cl hydrogen bonds and C-H⋯π inter-actions.

  4. Study on Preparation Conditions of High-purity Magnesium Chloride%铵解水镁石工艺条件研究

    Institute of Scientific and Technical Information of China (English)

    赵丹丹; 沙聪聪; 韩春玉; 罗根祥; 刘春生

    2013-01-01

      确定了氯化铵是溶解水镁石较为合适的铵盐,考察了水镁石与氯化铵物质的量配比、反应温度以及反应时间等因素对水镁石溶解的影响.结果表明,在水镁石与氯化铵物质的量配比为1∶22、反应温度为100℃、反应时间为2 h的条件下,水镁石在氯化铵溶液中的溶解度最大,溶液中镁离子浓度达到了2.46%.%It’s identified that appropriate ammonium salt to dissolve the brucite was ammonium chloride. The effect of different factors on dissolving the brucite was investigated, such as ratio of ammonium chloride and brucite, reaction temperature and reaction time. The results show that:when the ratio of ammonium chloride and brucite is 1∶22, the reaction temperature is 100 ℃, the reaction time is 2 h, the solubility of the brucite in the ammonium chloride can reach the maximum, the ion concentration of magnesium is 2.46%.

  5. 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.

  6. Monoliths: A Review of the Basics, Preparation Methods and Their Relevance to Oxidation

    Directory of Open Access Journals (Sweden)

    Sandeeran Govender

    2017-02-01

    Full Text Available Considerable research has been conducted on monolithic catalysts for various applications. Strategies toward coating monoliths are of equal interest and importance. In this paper, the preparation of monoliths and monolithic catalysts have been summarized. More specifically, a brief explanation for the manufacturing of ceramic and metallic monoliths has been provided. Also, different methods for coating γ-alumina, as a secondary support, are included. Techniques used to deposit metal-based species, zeolites and carbon onto monoliths are discussed. Furthermore, monoliths extruded with metal oxides, zeolites and carbon are described. The main foci are on the reasoning and understanding behind the preparation of monolithic catalysts. Ideas and concerns are also contributed to encourage better approaches when designing these catalysts. More importantly, the relevance of monolithic structures to reactions, such as the selective oxidation of alkanes, catalytic combustion for power generation and the preferential oxidation of carbon monoxide, has been described.

  7. Polymethacrylate monolithic and hybrid particle-monolithic columns for reversed-phase and hydrophilic interaction capillary liquid chromatography.

    Science.gov (United States)

    Jandera, Pavel; Urban, Jirí; Skeríková, Veronika; Langmaier, Pavel; Kubícková, Romana; Planeta, Josef

    2010-01-01

    We prepared hybrid particle-monolithic polymethacrylate columns for micro-HPLC by in situ polymerization in fused silica capillaries pre-packed with 3-5microm C(18) and aminopropyl silica bonded particles, using polymerization mixtures based on laurylmethacrylate-ethylene dimethacrylate (co)polymers for the reversed-phase (RP) mode and [2-(methacryloyloxy)ethyl]-dimethyl-(3-sulfopropyl) zwitterionic (co)polymers for the hydrophilic interaction (HILIC) mode. The hybrid particle-monolithic columns showed reduced porosity and hold-up volumes, approximately 2-2.5 times lower in comparison to the pure monolithic columns prepared in the whole volume of empty capillaries. The elution volumes of sample compounds are also generally lower in comparison to packed or pure monolithic columns. The efficiency and permeability of the hybrid columns are intermediate in between the properties of the reference pure monolithic and particle-packed columns. The chemistries of the embedded solid particles and of the interparticle monolithic moiety in the hybrid capillary columns contribute to the retention to various degrees, affecting the selectivity of separation. Some hybrid columns provided improved separations of proteins in comparison to the reference particle-packed columns in the reversed-phase mode. Zwitterionic hybrid particle-monolithic columns show dual mode retention HILIC/RP behaviour depending on the composition of the mobile phase and allow separations of polar compounds such as phenolic acids in the HILIC mode at lower concentrations of acetonitrile and, often in shorter analysis time in comparison to particle-packed and full-volume monolithic columns.

  8. Biasable, Balanced, Fundamental Submillimeter Monolithic Membrane Mixer

    Science.gov (United States)

    Siegel, Peter; Schlecht, Erich; Mehdi, Imran; Gill, John; Velebir, James; Tsang, Raymond; Dengler, Robert; Lin, Robert

    2010-01-01

    This device is a biasable, submillimeter-wave, balanced mixer fabricated using JPL s monolithic membrane process a simplified version of planar membrane technology. The primary target application is instrumentation used for analysis of atmospheric constituents, pressure, temperature, winds, and other physical and chemical properties of the atmospheres of planets and comets. Other applications include high-sensitivity gas detection and analysis. This innovation uses a balanced configuration of two diodes allowing the radio frequency (RF) signal and local oscillator (LO) inputs to be separated. This removes the need for external diplexers that are inherently narrowband, bulky, and require mechanical tuning to change frequency. Additionally, this mixer uses DC bias-ability to improve its performance and versatility. In order to solve problems relating to circuit size, the GaAs membrane process was created. As much of the circuitry as possible is fabricated on-chip, making the circuit monolithic. The remainder of the circuitry is precision-machined into a waveguide block that holds the GaAs circuit. The most critical alignments are performed using micron-scale semiconductor technology, enabling wide bandwidth and high operating frequencies. The balanced mixer gets superior performance with less than 2 mW of LO power. This can be provided by a simple two-stage multiplier chain following an amplifier at around 90 GHz. Further, the diodes are arranged so that they can be biased. Biasing pushes the diodes closer to their switching voltage, so that less LO power is required to switch the diodes on and off. In the photo, the diodes are at the right end of the circuit. The LO comes from the waveguide at the right into a reduced-height section containing the diodes. Because the diodes are in series to the LO signal, they are both turned on and off simultaneously once per LO cycle. Conversely, the RF signal is picked up from the RF waveguide by the probe at the left, and flows

  9. 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.

  10. 77 FR 47291 - Residues of Didecyl Dimethyl Ammonium Chloride; Exemption From the Requirement of a Tolerance

    Science.gov (United States)

    2012-08-08

    ... cooling tower uses to which aquatic animals may be exposed. These levels were not considered appropriate... available at http://www.epa.gov/dockets . FOR FURTHER INFORMATION CONTACT: Tracy Lantz, Antimicrobials.... Potentially affected entities may include, but are not limited to: Crop production (NAICS code 111)....

  11. 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.

  12. Effects of Aromatic Ammoniums on Methyl Ammonium Lead Iodide Hybrid Perovskite Materials

    Directory of Open Access Journals (Sweden)

    Jianli Yang

    2017-01-01

    Full Text Available The introduction of bulky ammoniums into methyl ammonium lead iodide hybrid perovskites (MAPbI3 has emerged as a promising strategy to improve the properties of these materials. In the present work, we studied the effects of several aromatic ammoniums onto the structural, electronic, and optical properties of MAPbI3. Although powder XRD data suggest that the bulky cations are not involved in the bulk phase of the MAPbI3, a surprisingly large effect of the bulky cations onto the photoluminescence properties was observed.

  13. Review of Ammonium Dinitramide Toxicity Studies

    Science.gov (United States)

    2011-01-01

    reproductive toxicant in rats, causing implantation failure in early gestation; follow-on studies implied that ADN is embryotoxic . EPR studies indicated that...mutagenic. 15. SUBJECT TERMS Ammonium dinitramide, ADN, toxicity, reproductive, embryotoxic , genotoxicity 16. SECURITY CLASSIFICATION OF: U 17...reproductive studies, reproduction and fertility, pre-implantation and post-implantation studies, implied that ADN is embryotoxic . A mouse embryo

  14. 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

  15. 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

  16. Dedicated monolithic infrared spectrometer for process monitoring

    Science.gov (United States)

    Chadha, Suneet; Kyle, William; Bolduc, Roy A.; Curtiss, Lawrence E.

    1999-12-01

    Foster-Miller has leveraged its innovations in IR fiber- optic probes and the recent development of a miniature spectrometer to build a novel IR sensor system for process applications. The developed sensor systems is a low-cost alternative to process FTIR and filter based systems. A monolithic wedge-grating optic provides the spectral dispersion with low cost thermopile point or array detectors picking off the diffracted wavelengths from the optic. The integrated optic provides spectral discrimination between 3- 12 micrometers with resolution at 8 cm-1 or better and high overall optical throughput. The device has a fixed cylindrical grating uniquely bonded to the edge of a ZnSe conditioning 'wedge'. The conditioning optic overcomes limitations of concave gratings as it accepts high angle light at the narrow end of the wedge and progressively conditions it to be near normal to the grating. On return, the diffracted wavelengths are concentrated on the discrete or array detector elements by the wedge, providing throughput comparable to that of an FTIR. The miniature spectrometer coupled to flow through liquid cells or multipass gas cells provides significant cost advantage over conventional sampling methodologies. Currently, we are investigating process applications for the petroleum and dairy markets. The sensor system eliminates the cost, complexity, reliability and bandwidth/resolution problems associated with either Fabry Perot or Michelson Interferometer based approaches for low-cost process applications.

  17. The Advanced Virgo monolithic fused silica suspension

    Energy Technology Data Exchange (ETDEWEB)

    Aisa, D.; Aisa, S.; Campeggi, C.; Colombini, M. [University of Perugia and INFN Perugia (Italy); Conte, A. [University of Roma Sapienza and INFN Roma (Italy); Farnesini, L. [University of Perugia and INFN Perugia (Italy); Majorana, E.; Mezzani, F. [University of Roma Sapienza and INFN Roma (Italy); Montani, M. [University of Urbino and INFN Firenze (Italy); Naticchioni, L.; Perciballi, M. [University of Roma Sapienza and INFN Roma (Italy); Piergiovanni, F. [University of Urbino and INFN Firenze (Italy); Piluso, A. [University of Perugia and INFN Perugia (Italy); Puppo, P., E-mail: paola.puppo@roma1.infn.it [University of Roma Sapienza and INFN Roma (Italy); Rapagnani, P. [University of Roma Sapienza and INFN Roma (Italy); Travasso, F. [University of Perugia and INFN Perugia (Italy); Vicerè, A. [University of Urbino and INFN Firenze (Italy); Vocca, H. [University of Perugia and INFN Perugia (Italy)

    2016-07-11

    The detection of gravitational waves is one of the most challenging prospects faced by experimental physicists. Suspension thermal noise is an important noise source at operating frequencies between approximately 10 and 30 Hz, and represents a limit to the sensitivity of the ground based interferometric gravitational wave detectors. Its effects can be reduced by minimizing the losses and by optimizing the geometry of the suspension fiber as well as its attachment system. In this proceeding we will describe the mirrors double stage monolithic suspension system to be used in the Advanced Virgo (AdV) detector. We also present the results of the thermal noise study, performed with the help of a finite elements model, taking into account the precise geometry of the fibers attachment systems on the suspension elements. We shall demonstrate the suitability of this suspension for installation in AdV. - Highlights: • Suspension system design for the test masses of the gravitational wave detectors. • Finite element model studies. • Suspension thermal noise studies.

  18. Monolithic supports with unique geometries and enhanced mass transfer.

    Energy Technology Data Exchange (ETDEWEB)

    Stuecker, John Nicholas; Ferrizz, Robert Matthew; Cesarano, Joseph, III; Miller, James Edward

    2004-01-01

    The catalytic combustion of natural gas has been the topic of much research over the past decade. Interest in this technology results from a desire to decrease or eliminate the emissions of harmful nitrogen oxides (NOX) from gas turbine power plants. A low-pressure drop catalyst support, such as a ceramic monolith, is ideal for this high-temperature, high-flow application. A drawback to the traditional honeycomb monoliths under these operating conditions is poor mass transfer to the catalyst surface in the straight-through channels. 'Robocasting' is a unique process developed at Sandia National Laboratories that can be used to manufacture ceramic monoliths with alternative 3-dimensional geometries, providing tortuous pathways to increase mass transfer while maintaining low pressure drops. This report details the mass transfer effects for novel 3-dimensional robocast monoliths, traditional honeycomb-type monoliths, and ceramic foams. The mass transfer limit is experimentally determined using the probe reaction of CO oxidation over a Pt / {gamma}-Al{sub 2}O{sub 3} catalyst, and the pressure drop is measured for each monolith sample. Conversion versus temperature data is analyzed quantitatively using well-known dimensionless mass transfer parameters. The results show that, relative to the honeycomb monolith support, considerable improvement in mass transfer efficiency is observed for robocast samples synthesized using an FCC-like geometry of alternating rods. Also, there is clearly a trade-off between enhanced mass transfer and increased pressure drop, which can be optimized depending on the particular demands of a given application.

  19. Benzalkonium chloride and glaucoma.

    Science.gov (United States)

    Rasmussen, Carol A; Kaufman, Paul L; Kiland, Julie A

    2014-01-01

    Glaucoma patients routinely take multiple medications, with multiple daily doses, for years or even decades. Benzalkonium chloride (BAK) is the most common preservative in glaucoma medications. BAK has been detected in the trabecular meshwork (TM), corneal endothelium, lens, and retina after topical drop installation and may accumulate in those tissues. There is evidence that BAK causes corneal and conjunctival toxicity, including cell loss, disruption of tight junctions, apoptosis and preapoptosis, cytoskeleton changes, and immunoinflammatory reactions. These same effects have been reported in cultured human TM cells exposed to concentrations of BAK found in common glaucoma drugs and in the TM of primary open-angle glaucoma donor eyes. It is possible that a relationship exists between chronic exposure to BAK and glaucoma. The hypothesis that BAK causes/worsens glaucoma is being tested experimentally in an animal model that closely reflects human physiology.

  20. Chloride on the Move

    KAUST Repository

    Li, Bo

    2017-01-09

    Chloride (Cl−) is an essential plant nutrient but under saline conditions it can accumulate to toxic levels in leaves; limiting this accumulation improves the salt tolerance of some crops. The rate-limiting step for this process – the transfer of Cl− from root symplast to xylem apoplast, which can antagonize delivery of the macronutrient nitrate (NO3−) to shoots – is regulated by abscisic acid (ABA) and is multigenic. Until recently the molecular mechanisms underpinning this salt-tolerance trait were poorly defined. We discuss here how recent advances highlight the role of newly identified transport proteins, some that directly transfer Cl− into the xylem, and others that act on endomembranes in ‘gatekeeper’ cell types in the root stele to control root-to-shoot delivery of Cl−.

  1. Impact of temperature on ammonium and nitrite removal rates in RAS moving bed biofilters

    DEFF Research Database (Denmark)

    Kinyage, John Peter Hewa; Pedersen, Lars-Flemming

    2016-01-01

    at each of the six temperatures (6, 12, 18, 24, 30 and 36 °C) and then spiked with ammonium chloride or sodium nitrite under identical conditions. The average surface specific TAN removal (STR) increased a six-fold from 6 to 30 °C (0.04–0.25 g TAN m−2 day−1) and dropped significantly at 36 °C–0.14 g TAN m......The impact of temperature on bacterial processes is well known; however temperature related data on nitrification rates in aquaculture systems are fragmented and compiled from different studies. We sought to determine ammonium and nitrite removal kinetics over a temperature range from 6 to 36 °C...... by using moving bed bio-elements from a freshwater RAS in steady state operated at 18 °C. The impact of temperature on ammonium and nitrite oxidation rates was evaluated by transferring the colonized bio elements to six liter batch reactors (triplicated setup). Each reactor was acclimatized for 24 h...

  2. Ammonium sensing in aqueous solutions with plastic optical fiber modified by molecular imprinting

    Science.gov (United States)

    Sequeira, F.; Duarte, D.; Rudnitskaya, A.; Gomes, M. T. S. R.; Nogueira, R.; Bilro, L.

    2016-05-01

    We report the development of a low cost plastic optical fibre (POF) sensor for ammonium detection using molecularly imprinted polymers (MIP's). The cladding of a 1 mm diameter PMMA fiber is removed, in which is grafted a molecular imprinted polymer (MIP), by radical polymerization with thermal initiation, that act as a selective sensing layer. For the polymerization, 2,2'-Azobis(2-methylpropionamidine)dihydrochloride (AAPH) is used as initiator, methacrylic acid (MAA) as a monomer, ethylene glycol dimethacrylate (EDMA) as a cross-linker, ammonium chloride (NH4Cl) as a template and 30% of ethanol in water as a solvent. The sensing method consists of an intensity based scheme. The response to different concentrations of ammonium solutions in water has been evaluated at room temperature. Solutions with (0 - 0.6) M concentration, with the corresponding refractive indexes varying between 1.3325 - 1.3387, at 25°C were used. The response of the fiber with the original cladding, and after cladding removal has been monitored and compared to the response given by the developed sensor. The response is very fast, less than 1 minute and reversible, which allows the continuum use of the sensor. Further developments are focused in optimization of MIP grafting procedure and sensor performance, in order to increase sensitivity.

  3. ADVANCED GASIFICATION MERCURY/TRACE METAL CONTROL WITH MONOLITH TRAPS

    Energy Technology Data Exchange (ETDEWEB)

    Mark A. Musich; Michael L. Swanson; Grant E. Dunham; Joshua J. Stanislowski

    2010-07-31

    Two Corning monoliths and a non-carbon-based material have been identified as potential additives for mercury capture in syngas at temperatures above 400°F and pressure of 600 psig. A new Corning monolith formulation, GR-F1-2189, described as an active sample appeared to be the best monolith tested to date. The Corning SR Liquid monolith concept continues to be a strong candidate for mercury capture. Both monolith types allowed mercury reduction to below 5-μg/m3 (~5 ppb), a current U.S. Department of Energy (DOE) goal for trace metal control. Preparation methods for formulating the SR Liquid monolith impacted the ability of the monolith to capture mercury. The Energy & Environmental Research Center (EERC)-prepared Noncarbon Sorbents 1 and 2 appeared to offer potential for sustained and significant reduction of mercury concentration in the simulated fuel gas. The Noncarbon Sorbent 1 allowed sustained mercury reduction to below 5-μg/m3 (~5 ppb). The non-carbon-based sorbent appeared to offer the potential for regeneration, that is, desorption of mercury by temperature swing (using nitrogen and steam at temperatures above where adsorption takes place). A Corning cordierite monolith treated with a Group IB metal offered limited potential as a mercury sorbent. However, a Corning carbon-based monolith containing prereduced metallic species similar to those found on the noncarbon sorbents did not exhibit significant or sustained mercury reduction. EERC sorbents prepared with Group IB and IIB selenide appeared to have some promise for mercury capture. Unfortunately, these sorbents also released Se, as was evidenced by the measurement of H2Se in the effluent gas. All sorbents tested with arsine or hydrogen selenide, including Corning monoliths and the Group IB and IIB metal-based materials, showed an ability to capture arsine or hydrogen selenide at 400°F and 600 psig. Based on current testing, the noncarbon metal-based sorbents appear to be the most effective arsine

  4. Recent advances in polymer monoliths for ion-exchange chromatography.

    Science.gov (United States)

    Nordborg, Anna; Hilder, Emily F

    2009-05-01

    The use of polymeric materials in ion-exchange chromatography applications is advantageous because of their typically high mechanical stability and tolerance of a wide range of pH conditions. The possibility of using polymeric monoliths in ion-exchange chromatography is therefore obvious and many of the same strategies developed for polymeric particles have been adapted for use with polymeric monoliths. In this review different strategies for the synthesis of polymeric monoliths with ion-exchange functionality are discussed. The incorporation of ion-exchange functionality by co-polymerization is included, as also are different post-polymerization alterations to the monolith surface such as grafting. The formulations and strategies presented include materials intended for use in analytical separations in ion-exchange chromatography, sample pre-treatment or enrichment applications, and materials for capillary electrochromatography. Finally, examples of the use of polymeric monoliths in ion-exchange chromatography applications are included with examples published in the years 2003 to 2008.

  5. New Graphene Form of Nanoporous Monolith for Excellent Energy Storage.

    Science.gov (United States)

    Bi, Hui; Lin, Tianquan; Xu, Feng; Tang, Yufeng; Liu, Zhanqiang; Huang, Fuqiang

    2016-01-13

    Extraordinary tubular graphene cellular material of a tetrahedrally connected covalent structure was very recently discovered as a new supermaterial with ultralight, ultrastiff, superelastic, and excellent conductive characteristics, but no high specific surface area will keep it from any next-generation energy storage applications. Herein, we prepare another new graphene monolith of mesoporous graphene-filled tubes instead of hollow tubes in the reported cellular structure. This graphene nanoporous monolith is also composed of covalently bonded carbon network possessing high specific surface area of ∼1590 m(2) g(-1) and electrical conductivity of ∼32 S cm(-1), superior to graphene aerogels and porous graphene forms self-assembled by graphene oxide. This 3D graphene monolith can support over 10 000 times its own weight, significantly superior to CNT and graphene cellular materials with a similar density. Furthermore, pseudocapacitance-active functional groups are introduced into the new nanoporous graphene monolith as an electrode material in electrochemical capacitors. Surprisingly, the electrode of 3D mesoporous graphene has a specific capacitance of 303 F g(-1) and maintains over 98% retention after 10 000 cycles, belonging to the list for the best carbon-based active materials. The macroscopic mesoporous graphene monolith suggests the great potential as an electrode for supercapacitors in energy storage areas.

  6. 21 CFR 184.1141b - Ammonium phosphate, dibasic.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ammonium phosphate, dibasic. 184.1141b Section 184... Listing of Specific Substances Affirmed as GRAS § 184.1141b Ammonium phosphate, dibasic. (a) Ammonium phosphate, dibasic ((NH4)2HPO4, CAS Reg. No. 7783-28-0) is manufactured by reacting ammonia with...

  7. 78 FR 32690 - Certain Ammonium Nitrate From Ukraine

    Science.gov (United States)

    2013-05-31

    ... COMMISSION Certain Ammonium Nitrate From Ukraine Determination On the basis of the record \\1\\ developed in... antidumping duty order on certain ammonium nitrate from Ukraine would be likely to lead to continuation or... Publication 4396 (May 2013), entitled Certain Ammonium Nitrate from Ukraine: Investigation No....

  8. 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...

  9. Monolithic View of Galaxy Formation and Evolution

    Directory of Open Access Journals (Sweden)

    Cesare Chiosi

    2014-07-01

    Full Text Available We review and critically discuss the current understanding of galaxy formation and evolution limited to Early Type Galaxies (ETGs as inferred from the observational data and briefly contrast the hierarchical and quasi-monolithic paradigms of formation and evolution. Since in Cold Dark Matter (CDM cosmogony small scale structures typically collapse early and form low-mass haloes that subsequently can merge to assembly larger haloes, galaxies formed in the gravitational potential well of a halo are also expected to merge thus assembling their mass hierarchically. Mergers should occur all over the Hubble time and large mass galaxies should be in place only recently. However, recent observations of high redshift galaxies tell a different story: massive ETGs are already in place at high redshift. To this aim, we propose here a revision of the quasi-monolithic scenario as an alternative to the hierarchical one, in which mass assembling should occur in early stages of a galaxy lifetime and present recent models of ETGs made of Dark and Baryonic Matter in a Λ-CDM Universe that obey the latter scheme. The galaxies are followed from the detachment from the linear regime and Hubble flow at z ≥ 20 down to the stage of nearly complete assembly of the stellar content (z ∼ 2 − 1 and beyond.  It is found that the total mass (Mh = MDM + MBM and/or initial over-density of the proto-galaxy drive the subsequent star formation histories (SFH. Massive galaxies (Mh ~ _1012M⊙ experience a single, intense burst of star formation (with rates ≥ 103M⊙/yr at early epochs, consistently with observations, with a weak dependence on the initial over-density; intermediate mass haloes (Mh~_ 1010 − 1011M⊙ have star formation histories that strongly depend on their initial over-density; finally, low mass haloes (Mh ~_ 109M⊙ always have erratic, burst-like star forming histories. The present-day properties (morphology, structure, chemistry and photometry of the

  10. Monolithic Solid Oxide Fuel Cell development

    Science.gov (United States)

    Myles, K. M.; McPheeters, C. C.

    1989-12-01

    The Monolithic Solid Oxide Fuel Cell (MSOFC) is an oxide-ceramic structure in which appropriate electronic and ionic conductors are fabricated in a honeycomb shape similar to a block of corrugated paperboard. These electronic and ionic conductors are arranged to provide short conduction paths to minimize resistive losses. The power density achievable with the MSOFC is expected to be about 8 kW/kg or 4 kW/L, at fuel efficienceis over 50 percent, because of small cell size and low resistive losses in the materials. The MSOFC operates in the range of 700 to 1000 C, at which temperatures rapid reform of hydrocarbon fuels is expected within the nickel-YSZ fuel channels. Tape casting and hot roll calendering are used to fabricate the MSOFC structure. The performance of the MSOFC has improved significantly during the course of development. The limitation of this system, based on materials resistance alone without interfacial resistances, is 0.093 ohm-sq cm area-specific resistance (ASR). The current typical performance of MSOFC single cells is characterized by ASRs of about 0.4 to 0.5 ohm-sq cm. With further development the ASR is expected to be reduced below 0.2 ohm-sq cm, which will result in power levels greater than 1.4 W/sq cm. The feasibility of the MSOFC concept was proven, and the performance was dramatically improved. The differences in thermal expansion coefficients and firing shrinkages among the fuel cell materials were minimized. As a result of good matching of these properties, the MSOFC structure was successfully fabricated with few defects, and the system shows excellent promise for development into a practical power source.

  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. Monolithic fuel cell based power source for burst power generation

    Science.gov (United States)

    Fee, D. C.; Blackburn, P. E.; Busch, D. E.; Dees, D. W.; Dusek, J.; Easler, T. E.; Ellingson, W. A.; Flandermeyer, B. K.; Fousek, R. J.; Heiberger, J. J.

    A unique fuel cell coupled with a low power nuclear reactor presents an attractive approach for SDI burst power requirements. The monolithic fuel cell looks attractive for space applications and represents a quantum jump in fuel cell technology. Such a breakthrough in design is the enabling technology for lightweight, low volume power sources for space based pulse power systems. The monolith is unique among fuel cells in being an all solid state device. The capability for miniaturization, inherent in solid state devices, gives the low volume required for space missions. In addition, the solid oxide fuel cell technology employed in the monolith has high temperature reject heat and can be operated in either closed or open cycles. Both these features are attractive for integration into a burst power system.

  13. A Possible Astronomically Aligned Monolith at Gardom's Edge

    CERN Document Server

    Brown, D; Bemand, E

    2012-01-01

    A unique triangular shaped monolith located within the Peak District National Park at Gardom's Edge could be intentionally astronomically aligned. It is set within a landscape rich in late Neolithic and Bronze Age remains. We show that the stone is most likely in its original orientation owing to its clear signs of erosion and associated to the time period of the late Neolithic. It is tilted towards South and its North side slopes at an angle equal to the maximum altitude of the Sun at mid-summer. This alignment emphasizes the changing declinations of the Sun during the seasons as well as giving an indication of mid-summers day. This functionality is achieved by an impressive display of light and shadow on the North-facing side of the Monolith. Together with other monuments in the close vicinity the monolith would have represented an ideal marker or social arena for seasonal gatherings for the else dispersed small communities.

  14. MONOLITHIC FUEL FABRICATION PROCESS DEVELOPMENT AT THE IDAHO NATIONAL LABORATORY_

    Energy Technology Data Exchange (ETDEWEB)

    G. A. Moore; F. J. Rice; N. E. Woolstenhulme; J-F. Jue; B. H. Park; S. E. Steffler; N. P. Hallinan; M. D. Chapple; M. C. Marshall; B. L. Mackowiak; C. R. Clark; B. H. Rabin

    2009-11-01

    Full-size/prototypic U10Mo monolithic fuel-foils and aluminum clad fuel plates are being developed at the Idaho National Laboratory’s (INL) Materials and Fuels Complex (MFC). These efforts are focused on realizing Low Enriched Uranium (LEU) high density monolithic fuel plates for use in High Performance Research and Test Reactors. The U10Mo fuel foils under development afford a fuel meat density of ~16 gU/cc and thus have the potential to facilitate LEU conversions without any significant reactor-performance penalty. An overview is provided of the ongoing monolithic UMo fuel development effort, including application of a zirconium barrier layer on fuel foils, fabrication scale-up efforts, and development of complex/graded fuel foils. Fuel plate clad bonding processes to be discussed include: Hot Isostatic Pressing (HIP) and Friction Bonding (FB).

  15. A Possible Astronomically Aligned Monolith at Gardom's Edge

    Science.gov (United States)

    Brown, Daniel; Alder, Andy; Bemand, Elizabeth

    2015-05-01

    A unique triangular shaped monolith located within the Peak District National Park at Gardom's Edge could be intentionally astronomically aligned. It is set within a landscape rich in late Neolithic and Bronze Age remains. We show that the stone is most likely in its original orientation owing to its clear signs of erosion and associated to the time period of the late Neolithic. It is tilted towards south and its north side slopes at an angle equal to the maximum altitude of the Sun at mid-summer. This alignment emphasizes the changing declinations of the Sun during the seasons as well as giving an indication of mid-summers day. This functionality is achieved by an impressive display of light and shadow on the north facing side of the monolith. Together with other monuments in the close vicinity the monolith would have represented an ideal marker or social arena for seasonal gatherings for the otherwise dispersed small communities.

  16. Preliminary shielding analysis for the CSNS target station monolith

    Institute of Scientific and Technical Information of China (English)

    张斌; 陈义学; 杨寿海; 吴军; 殷雯; 梁天骄; 贾学军

    2010-01-01

    The construction of the China Spallation Neutron Source (CSNS) has been initiated at Dongguan,Guangdong,China.In spallation neutron sources the target station monolith is contaminated by a large number of fast neutrons whose energies can be as large as those of the protons of the proton beam directed towards the tungsten target.A detailed radiation transport analysis of the target station monolith is important for the construction of the CSNS.The analysis is performed using the coupled Monte Carlo and multi-dimensional discrete ordinates method.Successful elimination of the primary ray effects via the two-dimensional uncollided flux and first collision source methodology is also illustrated.The dose at the edge of the monolith is calculated.The results demonstrate that the doses received by the hall staff members are below the required standard limit.

  17. Design of Monolithic Integrator for Strain-to-Frequency Converter

    Directory of Open Access Journals (Sweden)

    Tuan Mohd. Khairi Tuan Mat

    2012-01-01

    Full Text Available Strain-to-Frequency converter (SFC is a one of the analog conditioner tools that converts any strain signal to the frequency signal. The basic concept of SFC is by detecting any changing of strains, then converting the strain to the voltage signal and converting the voltage signal to the frequency signal. This tool consists of 3 main  components which are strain gauge, differential integrator and comparator. This paper presents the designing and analysis of monolithic integrator that to be used in the Strain-toFrequency converter. The primary goal is to design and simulate the performance of monolithic integrator for SFC using GATEWAY Silvaco Electronic Design Automation (S EDA tools and EXPERT software. The performances of SFC using the designed monolithic integrator are also investigated.

  18. Molecularly imprinted macroporous monolithic materials for protein recognition

    Institute of Scientific and Technical Information of China (English)

    Qi Liang Deng; Yan Li Li; Li Hua Zhang; Yu Kui Zhang

    2011-01-01

    Synthetic materials that can specifically recognize proteins will find wide application in many fields. In this report, bovine serum albumin was chosen as the template protein. Acrylamide and N, N'-methylenebisacrylamide were employed as the functional and cross-linker monomers, respectively. Molecularly imprinted macroporous monolithic materials that can preferentially bind the template protein in an aqueous environment were prepared by combination of molecular imprinting technique and freezing/thawing preparation method. The resulted imprinted macroporous monolithic columns were evaluated by utilizing as stationary phase in high performance liquid chromatography and solid-phase extraction materials. The experimental results indicated that the imprinted macroporous monolithic column exhibited good recognition for template protein, as compared with the control protein (hemoglobin), whereas the non-imprinted polymer (prepared under the same conditions except without addition template protein) had no selective properties.

  19. Quaternary ammonium compounds – New occupational hazards

    Directory of Open Access Journals (Sweden)

    Agnieszka Lipińska-Ojrzanowska

    2014-10-01

    Full Text Available Quaternary ammonium compounds (QACs, quats belong to organic ionic chemical agents which display unique properties of both surfactants and disinfectants. Their wide distribution in the work environment and also in private households brings about new occupational hazards. This paper reviews reports about the health effects of QACs. QACs could play a role of sensitizers and irritants to the skin and mucous membranes. It is suspected that particular QACs can display an immunologic crossreactivity between each other and with other chemical compounds containing ammonium ion, such as muscle relaxants widely used in anesthesia. They may promote the development of airway allergy, however, the background mechanisms are still unclear and need to be further investigated. Until now, a few cases of occupational asthma induced by QACs have been described and their involvement in contact dermatitis has been documented. The possibility of anaphylaxis due to QACs cannot be excluded as well. Med Pr 2014;65(5:675–682

  20. 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.

  1. 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.

  2. Quaternary ammonium biocides as antimicrobial agents protecting historical wood and brick.

    Science.gov (United States)

    Rajkowska, Katarzyna; Koziróg, Anna; Otlewska, Anna; Piotrowska, Małgorzata; Nowicka-Krawczyk, Paulina; Brycki, Bogumił; Kunicka-Styczyńska, Alina; Gutarowska, Beata

    2016-01-01

    Quaternary ammonium compounds (QACs) are widely used in disinfection of water, surfaces and instruments as well as in textile, leather and food industries because of their relatively low toxicity, broad antimicrobial spectrum, non-volatility and chemical stability. Due to these advantages, QACs are also used in restoration and can be applied on historical material. The aim of this study was to determine the usefulness of biocides based on quaternary ammonium salts and containing various excipients in the protection of historical materials against microbial growth. The study determined the antimicrobial activity of three biocides against bacteria: Pseudomonas fluorescens, Staphylococcus equorum, Bacillus cereus, Bacillus muralis, Sporosarcina aquimarina and Rhodococcus fascians, and moulds: Chaetomium globosum, Penicillium citreonigrum, Cladosporium cladosporioides I, Acremonium strictum, Aspergillus fumigatus and Cladosporium cladosporioides II, all isolated from historical wood and brick. Staphylococcus equorum, Bacillus cereus, Sporosarcina aquimarina and Rhodococcus fascians bacteria, and Cladosporium cladosporioides I and Acremonium strictum moulds showed high sensitivity to quaternary ammonium biocides. Historical wood can be effectively disinfected by three applications of biocide A (30% v/v) containing dodecyl dimethyl ammonium chloride (DDAC), citric acid, propiconazole and propanol. Disinfection of historical brick can be carried out by three applications of 6% v/v solutions of biocide B (based on DDAC and ethylenediaminetetraacetic acid - EDTA) or biocide C (containing a non-ionic surfactant, DDAC and EDTA). Effective protection of historical building materials against microbial growth for a period of seven days can be achieved by the application of biocide A (30% v/v) on the wood surface and biocide B (6% v/v) on the brick surface.

  3. Preparation of poly(γ-glutamic acid)/hydroxyapatite monolith via biomineralization for bone tissue engineering.

    Science.gov (United States)

    Park, Sung-Bin; Hasegawa, Urara; van der Vlies, André J; Sung, Moon-Hee; Uyama, Hiroshi

    2014-01-01

    A hybrid monolith of poly(γ-glutamic acid) and hydroxyapatite (PGA/HAp monolith) was prepared via biomineralization and used as a macroporous cell scaffold in bone tissue engineering. The PGA monolith having a bimodal pore size distribution was used as a substrate to induce biomineralization. The PGA/HAp monolith was obtained by immersing the PGA monolith in simulated body fluid. Pretreatment with CaCl2 enhanced the apatite-forming ability of the PGA monolith. Murine osteoblastic MC3T3-E1 cells efficiently attached and proliferated on the PGA/HAp monolith. MTT assay showed that both the PGA and PGA/HAp monolith did not have apparent cytotoxicity. Moreover, the PGA and PGA/HAp monoliths adsorbed bone morphogenetic protein-2 (BMP-2) by electrostatic interaction which was slowly released in the medium during cell culture. The PGA/HAp monolith enhanced BMP-2 induced alkaline phosphatase activity compared to the PGA monolith and a polystyrene culture plate. Thus, these PGA/HAp monoliths may have potential in bone tissue engineering.

  4. Novel Microwave-Assisted Synthesis of the Immunomodulator Organotellurium Compound Ammonium Trichloro(dioxoethylene-O,O'tellurate (AS101

    Directory of Open Access Journals (Sweden)

    M. Pilar Vázquez-Tato

    2014-02-01

    Full Text Available Ammonium trichloro[1,2-ethanediolato-O,O']-tellurate (AS101 is the most important synthetic Te compound from the standpoint of its biological activity. It is a potent immunomodulator with a variety of potential therapeutic applications and antitumoral action in several preclinical and clinical studies. An experimental design has been used to develop and optimize a novel microwave-assisted synthesis (MAOS of the AS101. In comparison to the results observed in the literature, refluxing Te(IV chloride and ethylene glycol in acetonitrile (Method A, or by refluxing Te(IV chloride and ammonium chloride in ethylene glycol (Method B, it was found that the developed methods in the present work are an effective alternative, because although performance slightly decreases compared to conventional procedures (75% vs. 79% by Method A, and 45% vs. 51% by Method B, reaction times decreased from 4 h to 30 min and from 4 h to 10 min, by Methods A and B respectively. MAOS is proving to be of value in the rapid synthesis of compounds with new and improved biological activities, specially based on the benefit of its shorter reaction times.

  5. Synthesis of ZSM-5 Monoliths with Hierarchical Porosity

    Institute of Scientific and Technical Information of China (English)

    Tong Yangchuan; Zhao Tianbo; Li Fengyan; Zong Baoning; Wang Yue

    2006-01-01

    A new route to synthesize ZSM-5 monoliths with hierarchical pore structure has been referred to in this stud y. The successful incorporation of the macropores and mesopores within the ZSM-5 structure was achieved through transforming the skeleton of the macroporous silica gel into zeolite ZSM-5 using carbon materials as the transitional template. The ZSM-5 crystal covered part of the macroporous material, and provided micropores to the macroporous silica gel. The structure of carbon monolith was studied after dissolving the silica contained in the carbon/silica composite.

  6. Monolithic Michelson Interferometer as ultra stable wavelength reference

    Science.gov (United States)

    Wan, Xiaoke; Ge, Jian

    2010-07-01

    Ultra-stable Monolithic Michelson interferometer can be an ideal reference for highprecision applications such as RV measurement in planet searching and orbit study. The advantages include wide wavelength range, simple sinusoidal spectral format, and high optical efficiency. In this paper, we report that a monolithic Michelson interferometers has been in-house developed with minimized thermal sensitivity with compensation tuning. With a scanning white light interferometer, the thermal sensitivity is measured ~ 6x10-7/°C at 550 nm and it decreases to zero near 1000 nm. We expect the wideband wavelength reference source to be stabilized better than 0.3 m/s for RV experiments

  7. Numerical Simulation of Fluid Dynamics in a Monolithic Column

    Directory of Open Access Journals (Sweden)

    Kazuhiro Yamamoto

    2017-01-01

    Full Text Available As for the measurement of polycyclic aromatic hydrocarbons (PAHs, ultra-performance liquid chromatography (UPLC is used for PAH identification and densitometry. However, when a solvent containing a substance to be identified passes through a column of UPLC, a dedicated high-pressure-proof device is required. Recently, a liquid chromatography instrument using a monolithic column technology has been proposed to reduce the pressure of UPLC. The present study tested five types of monolithic columns produced in experiments. To simulate the flow field, the lattice Boltzmann method (LBM was used. The velocity profile was discussed to decrease the pressure drop in the ultra-performance liquid chromatography (UPLC system.

  8. A Monolithic Oxide-Based Transversal Thermoelectric Energy Harvester

    Science.gov (United States)

    Teichert, S.; Bochmann, A.; Reimann, T.; Schulz, T.; Dreßler, C.; Udich, S.; Töpfer, J.

    2016-03-01

    We report the fabrication and properties of a monolithic transversal thermoelectric energy harvester based on the combination of a thermoelectric oxide and a metal. The fabrication of the device is done with a ceramic multilayer technology using printing and co-firing processes. Five transversal devices were combined to a meander-like thermoelectric generator. Electrical measurements and finite element calculations were performed to characterize the resulting thermoelectric generator. A maximum experimental electrical power output of 30.2 mW at a temperature difference of {Δ }T = 208 K was found. The prepared monolithic thermoelectric generator provides at {Δ }T = 35 K sufficient energy to drive a simple electronic sensor application.

  9. Paladin Enterprises: Monolithic particle physics models global climate.

    CERN Multimedia

    2002-01-01

    Paladin Enterprises presents a monolithic particle model of the universe which will be used by them to build an economical fusion energy system. The model is an extension of the work done by James Clerk Maxwell. Essentially, gravity is unified with electro-magnetic forces and shown to be a product of a closed loop current system, i.e. a particle - monolithic or sub atomic. This discovery explains rapid global climate changes which are evident in the geological record and also provides an explanation for recent changes in the global climate.

  10. Lectin-carbohydrate interactions on nanoporous gold monoliths.

    Science.gov (United States)

    Tan, Yih Horng; Fujikawa, Kohki; Pornsuriyasak, Papapida; Alla, Allan J; Ganesh, N Vijaya; Demchenko, Alexei V; Stine, Keith J

    2013-07-01

    Monoliths of nanoporous gold (np-Au) were modified with self-assembled monolayers of octadecanethiol (C18-SH), 8-mercaptooctyl α-D-mannopyranoside (αMan-C8-SH), and 8-mercapto-3,6-dioxaoctanol (HO-PEG2-SH), and the loading was assessed using thermogravimetric analysis (TGA). Modification with mixed SAMs containing αMan-C8-SH (at a 0.20 mole fraction in the SAM forming solution) with either octanethiol or HO-PEG2-SH was also investigated. The np-Au monoliths modified with αMan-C8-SH bind the lectin Concanavalin A (Con A), and the additional mass due to bound protein was assessed using TGA analysis. A comparison of TGA traces measured before and after exposure of HO-PEG2-SH modified np-Au to Con A showed that the non-specific binding of Con A was minimal. In contrast, np-Au modified with octanethiol showed a significant mass loss due to non-specifically adsorbed Con A. A significant mass loss was also attributed to binding of Con A to bare np-Au monoliths. TGA revealed a mass loss due to the binding of Con A to np-Au monoliths modified with pure αMan-C8-SH. The use of mass losses determined by TGA to compare the binding of Con A to np-Au monoliths modified by mixed SAMs of αMan-C8-SH and either octanethiol or HO-PEG2-SH revealed that binding to mixed SAM modified surfaces is specific for the mixed SAMs with HO-PEG2-SH but shows a significant contribution from non-specific adsorption for the mixed SAMs with octanethiol. Minimal adsorption of immunoglobulin G (IgG) and peanut agglutinin (PNA) towards the mannoside modified np-Au monoliths was demonstrated. A greater mass loss was found for Con A bound onto the monolith than for either IgG or PNA, signifying that the mannose presenting SAMs in np-Au retain selectivity for Con A. TGA data also provide evidence that Con A bound to the αMan-C8-SH modified np-Au can be eluted by flowing a solution of methyl α-D-mannopyranoside through the structure. The presence of Con A proteins on the modified np-Au surface was

  11. Preparation and characterization of poly(triallyl isocyanurate-co-trimethylolpropane triacrylate) monolith and its applications in the separation of small molecules by liquid chromatography.

    Science.gov (United States)

    Zhong, Jing; Hao, Mengbei; Li, Ruo; Bai, Ligai; Yang, Gengliang

    2014-03-14

    A new polymeric monolith was prepared in stainless-steel column and fused-silica capillary, respectively, by atom transfer radical polymerization technique. In the polymerization, triallyl isocyanurate (TAIC) was used as the functional monomer; trimethylolpropane triacrylate (TMPTA) as the crosslinking agent; polyethylene glycol 200 and 1,2-propanediol as the co-porogens; carbon tetrachloride as the initiator and ferrous chloride as the catalyst. The conditions of polymerization were optimized. Morphology of the prepared poly(TAIC-co-TMPTA) monolith was investigated by scanning electron microscopy; pore properties were assayed by mercury porosimetry and nitrogen adsorption. The characterization indicated that the prepared reversed-phase monolith possessed uniform structure, good permeability and mechanical stability. The column was used as the stationary phase of reversed phase high performance liquid chromatography (RP-HPLC) and capillary liquid chromatography (CLC) to separate the mixture of aromatic compounds. The new column performed around 125,000 theoretical plates per meter. The column showed good reproducibility: the relative standard deviation values of the retention factor values for aromatic compounds were less than 1.52% (n=7, column-to-column).

  12. Base stable quaternary ammonium ionic liquids

    OpenAIRE

    Lethesh, Kallidanthiyil Chellappan; Dehaen, Wim; Binnemans, Koen

    2014-01-01

    Ionic liquids with the bis(2-ethylhexyl)dimethylammonium cation, [BEDMA]+, were prepared by a halide-free route starting from the readily available secondary amine bis(2-ethylhexyl)amine. The following anions were considered: chloride, bromide, iodide, nitrate, hydrogensulphate, dihydrogenphosphate, formate, acetate, propionate, trifluoroacetate, methyl sulphate, methanesulphonate, tosylate, isonicotinate, nicotinate and picolinate. Several of the compounds are room-temperature ionic liquids,...

  13. Spatial and temporal distribution of the leaching of surface applied tracers from an irrigated monolith of a loamy vineyard soil.

    Science.gov (United States)

    Bloem, E; Hermon, K M; de Rooij, G H; Stagnitti, F

    2014-01-01

    Fresh water scarcity is an increasing problem worldwide. Strategies to alleviate water scarcity include the use of low-quality water for irrigation. The risk of groundwater contamination by pollutants in this water is affected by soil heterogeneity and preferential flow. These risk factors can be assessed by measuring the spatio-temporal redistribution of uniformly applied water and solutes. We placed a soil monolith (height 29 cm) from an Australian vineyard on a 100-cell multi-compartment sampler (MCS). At this vineyard, treated wastewater is used in response to the severe shortage of water in the summer. We studied the leaching risk associated with heterogeneous or preferential flow by irrigating the soil column with 24 applications to simulate one year. We applied simulated rainfall as well as wastewater (which contained chloride) during summer while relying on rainfall only in winter. We compared the chloride leaching with the leaching of bromide, which was applied during one of the applications as a pulse. During the entire simulated year, leaching of solutes from the monolith was measured. The results indicate that the assumption of uniform flow would underestimate the risk for the fresh groundwater reserves: 25% of the solutes are transported though 6% of the soil's cross-section. The spatial distribution of drainage and solute leaching varied little during the experiment. Consequently, the mass flux density pattern of the bromide pulse was comparable to that of the repeatedly applied chloride. However, the MCS data suggested lateral 'escape' from chloride to non-mobile areas, which means in the long run, considerable quantities of these solutes can build up in areas that do not receive irrigation water.

  14. Studies Update Vinyl Chloride Hazards.

    Science.gov (United States)

    Rawls, Rebecca

    1980-01-01

    Extensive study affirms that vinyl chloride is a potent animal carcinogen. Epidemiological studies show elevated rates of human cancers in association with extended contact with the compound. (Author/RE)

  15. Strontium chloride-catalyzed one-pot synthesis of 2, 3-dihydroquinazolin-4(1H)-ones in protic media

    Institute of Scientific and Technical Information of China (English)

    Min Wang; Ting Ting Zhang; Yan Liang; Jing Jing Gao

    2011-01-01

    A wide range of mono- and disubstituted 2, 3-dihydroquinazolin-4(1H)-ones were obtained in high yields by condensation of isatoic anhydride, aldehydes with ammonium salts or primary amines in the presence of strontium chloride in aqueous ethanol under reflux.

  16. Constitutive Theory Developed for Monolithic Ceramic Materials

    Science.gov (United States)

    Janosik, Lesley A.

    1998-01-01

    with these service conditions by developing a multiaxial viscoplastic constitutive model that accounts for time-dependent hereditary material deformation (such as creep and stress relaxation) in monolithic structural ceramics. Using continuum principles of engineering mechanics, we derived the complete viscoplastic theory from a scalar dissipative potential function.

  17. Polyurea-Based Aerogel Monoliths and Composites

    Science.gov (United States)

    Lee, Je Kyun

    2012-01-01

    aerogel insulation material was developed that will provide superior thermal insulation and inherent radiation protection for government and commercial applications. The rubbery polyureabased aerogel exhibits little dustiness, good flexibility and toughness, and durability typical of the parent polyurea polymer, yet with the low density and superior insulation properties associated with aerogels. The thermal conductivity values of polyurea-based aerogels at lower temperature under vacuum pressures are very low and better than that of silica aerogels. Flexible, rubbery polyurea-based aerogels are able to overcome the weak and brittle nature of conventional inorganic and organic aerogels, including polyisocyanurate aerogels, which are generally prepared with the one similar component to polyurethane rubber aerogels. Additionally, with higher content of hydrogen in their structures, the polyurea rubber-based aerogels will also provide inherently better radiation protection than those of inorganic and carbon aerogels. The aerogel materials also demonstrate good hydrophobicity due to their hydrocarbon molecular structure. There are several strategies to overcoming the drawbacks associated with the weakness and brittleness of silica aerogels. Development of the flexible fiber-reinforced silica aerogel composite blanket has proven to be one promising approach, providing a conveniently fielded form factor that is relatively robust in industrial environments compared to silica aerogel monoliths. However, the flexible, silica aerogel composites still have a brittle, dusty character that may be undesirable, or even intolerable, in certain application environments. Although the cross - linked organic aerogels, such as resorcinol- formaldehyde (RF), polyisocyanurate, and cellulose aerogels, show very high impact strength, they are also very brittle with little elongation (i.e., less rubbery). Also, silica and carbon aerogels are less efficient radiation shielding materials due

  18. Chromatographic comparison of bupivacaine imprinted polymers prepared in crushed monolith, microsphere, silica-based composite and capillary monolith formats.

    Science.gov (United States)

    Oxelbark, Joakim; Legido-Quigley, Cristina; Aureliano, Carla S A; Titirici, Maria-Magdalena; Schillinger, Eric; Sellergren, Börje; Courtois, Julien; Irgum, Knut; Dambies, Laurent; Cormack, Peter A G; Sherrington, David C; De Lorenzi, Ersilia

    2007-08-10

    A comprehensive comparison of five chromatographic stationary phases based on molecularly imprinted polymers is presented. Efficiency, imprinting factors, water compatibility and batch-to-batch reproducibility are discussed for crushed monolith, microspheres, two silica-based composites and capillary monoliths, all imprinted with the local anaesthetic bupivacaine. Synthesis protocol and chromatographic test conditions have been kept fixed within certain limits, in order to provide further insight into the strengths and weaknesses of the different formats. Excluding microparticles, all formats give satisfactory performance, especially in aqueous mobile phases. An assessment of batch-to-batch reproducibility in different mobile phases adds further value to this comparison study.

  19. 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.

  20. 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.

  1. 46 CFR 151.50-34 - Vinyl chloride (vinyl chloride monomer).

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Vinyl chloride (vinyl chloride monomer). 151.50-34... chloride (vinyl chloride monomer). (a) Copper, aluminum, magnesium, mercury, silver, and their alloys shall... equipment that may come in contact with vinyl chloride liquid or vapor. (b) Valves, flanges, and...

  2. 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... AIR POLLUTANTS National Emission Standard for Vinyl Chloride § 61.65 Emission standard for ethylene dichloride, vinyl chloride and polyvinyl chloride plants. An owner or operator of an ethylene...

  3. From 1D to 3D - macroscopic nanowire aerogel monoliths.

    Science.gov (United States)

    Cheng, Wei; Rechberger, Felix; Niederberger, Markus

    2016-08-01

    Here we present a strategy to assemble one-dimensional nanostructures into a three-dimensional architecture with macroscopic size. With the assistance of centrifugation, we successfully gel ultrathin W18O49 nanowires with diameters of 1 to 2 nm and aspect ratios larger than 100 into 3D networks, which are transformed into monolithic aerogels by supercritical drying.

  4. Monolithic silica aerogel - material design on the nano-scale

    DEFF Research Database (Denmark)

    Jensen, Karsten Ingerslev; Schultz, Jørgen Munthe; Kristiansen, Finn Harken

    By means of a production process in two major steps - a sol/gel process and a supercritical drying – open-cell, monolithic silica aerogel can be made. This material can have a density in the range of 30- to 300 kg/m3, corresponding to porosities between 86 and 98 %. The solid structure has...

  5. A radiation hard bipolar monolithic front-end readout

    CERN Document Server

    Baschirotto, A; Cappelluti, I; Castello, R; Cermesoni, M; Gola, A; Pessina, G; Pistolesi, E; Rancoita, P G; Seidman, A

    1999-01-01

    A fast bipolar monolithic charge sensitive preamplifier (CSP), implemented in the monolithic 2 mu m BiCMOS technology (called HF2CMOS) was designed and built in a quad monolithic chip. Studies of radiation effects in the CSP $9 performance, from non-irradiated and up to neutron irradiation of 5.3*10/sup 14/ n/cm/sup 2/, have confirmed that the use of bipolar npn transistors is suitable for the radiation level of the future LHC collider environment. The CSP $9 presents a new circuit solution for obtaining adequate slew rate performances which results in an integral linearity better than 0.8554330n 5 V at 20 ns of shaping time, regardless of the bias current selected for the CSP. This way $9 the bias current of the CSP can be set for optimizing the power dissipation with respect to series and parallel noise, especially useful when the CSP is put in a radiation environment. A prototype test with a novel monolithic 20 ns $9 time constant RC-CR shaper, capable to sum up four inputs has been also realized, featurin...

  6. Cyclodextrin-Functionalized Monolithic Capillary Columns: Preparation and Chiral Applications.

    Science.gov (United States)

    Adly, Frady G; Antwi, Nana Yaa; Ghanem, Ashraf

    2016-02-01

    In this review, the recently reported approaches for the preparation of cyclodextrin-functionalized capillary monolithic columns are highlighted, with few applications in chiral separations using capillary liquid chromatography (CLC) and capillary electrochromatography (CEC). Chirality 28:97-109, 2016. © 2015 Wiley Periodicals, Inc.

  7. Carbon monolith: preparation, characterization and application as microextraction fiber.

    Science.gov (United States)

    Shi, Zhi-Guo; Chen, Fei; Xing, Jun; Feng, Yu-Qi

    2009-07-10

    A carbon monolith was synthesized via a polymerization-carbonization method, styrene and divinylbenzene being adopted as precursors and dodecanol as a porogen during polymerization. The resultant monolith had bimodal porous substructure, narrowly distributed nano skeleton pores and uniform textural pores or throughpores. The carbon monolith was directly used as an extracting fiber, taking place of the coated silica fibers in commercially available solid-phase microextraction device, for the extraction of phenols followed by gas chromatography-mass spectrometry. Under the studied conditions, the calibration curves were linear from 0.5 to 50 ng mL(-1) for phenol, o-nitrophenol, 2,4-dichlorophenol and p-chlorophenol. The limits of detection were between 0.04 and 0.43 ng mL(-1). The recoveries of the phenols spiked in real water samples at 10 ng mL(-1) were between 85% and 98% with the relative standard deviations below 10%. Compared with the commercial coated ones (e.g. PDMS, CW/DVB and DVB/CAR/PDMS), the carbon monolith-based fiber had advantages of faster extraction equilibrium and higher extraction capacity due to the superior pore connectivity and pore openness resulting from its bimodal porous substructure.

  8. Monolithic natural gas storage delivery system based on sorbents

    Energy Technology Data Exchange (ETDEWEB)

    Hornbostel, Marc; Krishnan, Gopala N.; Sanjurjo, Angel

    2016-09-27

    The invention provides methods for producing a strong, light, sorbent-based storage/dispenser system for gases and fuels. The system comprises a porous monolithic material with an adherent strong impervious skin that is capable of storing a gas under pressure in a safe and usable manner.

  9. Shear bond strength of indirect composite material to monolithic zirconia

    Science.gov (United States)

    2016-01-01

    PURPOSE This study aimed to evaluate the effect of surface treatments on bond strength of indirect composite material (Tescera Indirect Composite System) to monolithic zirconia (inCoris TZI). MATERIALS AND METHODS Partially stabilized monolithic zirconia blocks were cut into with 2.0 mm thickness. Sintered zirconia specimens were divided into different surface treatment groups: no treatment (control), sandblasting, glaze layer & hydrofluoric acid application, and sandblasting + glaze layer & hydrofluoric acid application. The indirect composite material was applied to the surface of the monolithic zirconia specimens. Shear bond strength value of each specimen was evaluated after thermocycling. The fractured surface of each specimen was examined with a stereomicroscope and a scanning electron microscope to assess the failure types. The data were analyzed using one-way analysis of variance (ANOVA) and Tukey LSD tests (α=.05). RESULTS Bond strength was significantly lower in untreated specimens than in sandblasted specimens (P<.05). No difference between the glaze layer and hydrofluoric acid application treated groups were observed. However, bond strength for these groups were significantly higher as compared with the other two groups (P<.05). CONCLUSION Combined use of glaze layer & hydrofluoric acid application and silanization are reliable for strong and durable bonding between indirect composite material and monolithic zirconia. PMID:27555895

  10. 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)

  11. 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.

  12. (S,S,S,S)-Nebivolol hydro-chloride hemihydrate.

    Science.gov (United States)

    Rousselin, Yoann; Bruel, Amelie; Clavel, Alexandre

    2012-12-01

    The asymmetric unit of the title hydrated salt, C22H26F2NO4(+)·Cl(-)·0.5H2O, consists of an (S,S,S,S)-nebivolol {nebivol = bis-[2-(6-fluoro-3,4-dihydro-2H-1-benzopyran-2-yl)-2-hy-droxy-eth-yl]ammonium} cation, a chloride anion and a half-occupancy water mol-ecule. The dihedral angle between the mean planes of the benzene rings is 50.34 (12)°. The pyran rings adopt half-chair conformations. The crystal packing features O-H⋯O hydrogen bonds and weak N-H⋯Cl, O-H⋯Cl, and O-H⋯Cl inter-actions, producing layers along (010).

  13. A hydrometallurgical process for recovering total metal values from waste monolithic ceramic capacitors.

    Science.gov (United States)

    Prabaharan, G; Barik, S P; Kumar, B

    2016-06-01

    A hydrometallurgical process for recovering the total metal values from waste monolithic ceramic capacitors was investigated. The process parameters such as time, temperature, acid concentration, hydrogen peroxide concentration and other reagents (amount of zinc dust and sodium formate) were optimized. Base metals such as Ba, Ti, Sn, Cu and Ni are leached out in two stages using HCl in stage 1 and HCl with H2O2 in stage 2. More than 99% of leaching efficiency for base metals (Cu, Ni, Ba, Ti and Sn) was achieved. Precious metals such as Au and Pd are leached out using aquaregia and nitric acid was used for the leaching of Ag. Base metals (Ba, Ti, Sn, Cu and Ni) are recovered by selective precipitation using H2SO4 and NaOH solution. In case of precious metals, Au and Pd from the leach solution were precipitated out using sodium metabisulphite and sodium formate, respectively. Sodium chloride was used for the precipitation of Ag from leach solution. Overall recovery for base metals and precious metals are 95% and 92%, respectively. Based on the results of the present study, a process flow diagram was proposed for commercial application.

  14. Stable Ammonium Bisulfate Clusters in the Atmosphere

    Science.gov (United States)

    Vehkamäki, Hanna; Napari, Ismo; Kulmala, Markku; Noppel, Madis

    2004-09-01

    Liquid drop model based equilibrium thermodynamics predicts that in the presence of even small ammonia concentrations practically all the atmospheric sulfuric acid molecules are bound to tiny, stable ammonium-bisulfate clusters. Hitherto sulfuric acid has been believed to form hydrates with water. Thermodynamic theory predicts correctly the hydrate formation observed experimentally. Results from ab initio computer simulations contradict the thermodynamic results and also the experimental findings for cluster formation in both sulfuric acid-water and ammonia-sulfuric acid-water mixtures.

  15. Synthesis and structure-activity study of quaternary ammonium functionalized beta-cyclodextrin-carboxymethylcellulose polymers.

    Science.gov (United States)

    Bonenfant, Danielle; Bourgeois, François-René; Mimeault, Murielle; Monette, Frédéric; Niquette, Patrick; Hausler, Robert

    2011-01-01

    Carboxymethylcellulose (CMC) and beta-cyclodextrin (beta-CD)-based polymers functionalized with two types of quaternary ammonium compounds (QACs), the alkaquat DMB-451 (N-alkyl (50% C14, 40% C12, 10% C10) dimethylbenzylammonium chloride) (DMD-451) named polymer DMB-451, and FMB 1210-8 (a blend of 32 w% N-alkyl (50% C14, 40% C12, 10% C10) dimethylbenzylammonium chloride and 48 w% of didecyldimethylammonium chloride) named polymer FMB 1210-8, were synthethized and characterized by Fourier transform infrared spectroscopy. The antimicrobial activities of these polymers against Eschericia coli were also evaluated at 25 degrees C in wastewater. The results have indicated that the polymer FMB 1210-8 possesses a high-affinity binding with bacterial cells that induces a rapid disinfection process. Moreover, in the same experimental conditions of disinfection (mixture of 1.0 g of polymer and 100 mL of wastewater), the polymer FMB 1210-8 has a higher antimicrobial efficiency (99.90%) than polymer DMB-451 (92.8%). This phenomenon might be associated to a stronger interaction with bacterial cells due to stronger binding affinity for E. coli cells and greater killing efficiency of the C10 alkyl chains QAC of polymer FMB 1210-8 to disrupt the bacterial cell membrane as compared to N-alkyl (50% C14, 40% C12, 10% C10) dimethylbenzylammonium chloride. Together, these results suggest that the polymer FMB 1210-8 could constitute a good disinfectant against Escherichia coli, which could be advantageously used in wastewater treatments due to the low toxicity of beta-CD and CMC, and moderated toxicity of FMB 1210-8 to human and environment.

  16. Sequential diffusion of ammonium and nitrate from soil extracts to a polytetrafluoroethylene trap for 15N determination

    DEFF Research Database (Denmark)

    Sørensen, P.; Jensen, E.S.

    1991-01-01

    A novel diffusion method was used for preparation of NH4+- and NO3--N samples from soil extracts for N-15 determination. Ammonium, and nitrate following reduction to ammonia, are allowed to diffuse to an acid-wetted glass filter enclosed in polytetrafluoroethylene tape. The method was evaluated...... with simulated soil extracts obtained using 50 ml of 2 M potassium chloride solution containing 130-mu-g of NH4+-N (2.3 atom% N-15) and 120-mu-g of NO3--N (natural N-15 abundance). No cross-over in the N-15 abundances of NH4+-N and NO3--N was observed, indicating a quantitative diffusion process (72 h, 25......-degrees-C). Owing to the presence of inorganic nitrogen impurities in the potassium chloride, the N-15 enrichments should be corrected for the blank nitrogen content....

  17. Synthesis of novel quaternary ammonium surfactants containing adamantane

    Institute of Scientific and Technical Information of China (English)

    Jian Wei Guo; Xing Zhong; Hua Zhu; Li Juan Feng; Ying De Cui

    2012-01-01

    A series of novel quaternary ammonium surfactants containing adamantane were designed and synthesized from 1-adamantanecarboxylic acid.The structures of target surfactants were confirmed by 1H NMR,elements analysis and FTIR.Surface properties of these surfactants were investigated.Due to the lipophilicity of adamantane,the critical micelle concentration (CMC) and C20 values of the synthesized quaternary ammonium surfactants are lower than that of conventional quaternary ammonium surfactants.

  18. 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.

  19. 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.

  20. 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...

  1. Organometallics and quaternary ammonium salts affect calcium ion desorption from lecithin liposome membranes.

    Science.gov (United States)

    Kral, T E; Kuczera, J; Przestalski, S

    2001-01-01

    The objective of the present work was to compare the effects of groups of tin and lead organometallic compounds and their mixtures with amphiphilic quaternary ammonium salts (QAS) on the process of calcium ion desorption from lecithin liposome membranes, as dependent on the properties of the hydrophilic and hydrophobic parts of QAS. In the investigations the method of radioactive labels was applied. Synergism and antagonism in the action of both groups of compounds were found. The effectiveness of the cooperation depended more on chain length of QAS compounds than on the size and polarity of their hydrophobic parts. The most effective of all compounds studied was a the mixture of benzyldimethylammonium chloride in a mixture with tripropyltin. Since the rate of calcium desorption proved to be a good measure of efficacy of biologically active surfactants, it seems that the conclusions reached in this paper may be useful for choosing compounds which are able to decontaminate the environment polluted with heavy metals.

  2. Lubiprostone: a chloride channel activator.

    Science.gov (United States)

    Lacy, Brian E; Levy, L Campbell

    2007-04-01

    In January 2006 the Food and Drug Administration approved lubiprostone for the treatment of chronic constipation in men and women aged 18 and over. Lubiprostone is categorized as a prostone, a bicyclic fatty acid metabolite of prostaglandin E1. Lubiprostone activates a specific chloride channel (ClC-2) in the gastrointestinal (GI) tract to enhance intestinal fluid secretion, which increases GI transit and improves symptoms of constipation. This article reviews the role of chloride channels in the GI tract, describes the structure, function, and pharmacokinetics of lubiprostone, and discusses clinically important data on this new medication.

  3. 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.

  4. 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

  5. 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.

  6. Determination of homologues of quaternary ammonium surfactants by capillary electrophoresis using indirect UV detection.

    Science.gov (United States)

    Liu, Hsueh-Ying; Ding, Wang-Hsien

    2004-02-06

    This investigation describes the simultaneous separation of two major non-chromophoric quaternary ammonium surfactants, alkyltrimethyl- and dialkyldimethylammonium compounds (ATMACs and DADMACs, respectively), by capillary electrophoresis (CE) using indirect UV detection. The most effective separation conditions was 10 mM phosphate buffer with 57.5% tetrahydrofuran and 3 mM sodium dodecyl sulfate (SDS) at pH 4.3, and the sample hydrodynamic injection of up to 20 s at 1 psi (approximately 60 nl), and an applied voltage of 25 kV (1 psi = 6.9 kPa). Specially, the selection of an appropriate chromophore and an internal standard (I.S.) to improve the peak identification and quantitation was systematically investigated. Decylbenzyldimethyl ammonium chloride (C10-BDMA+C-) as a chromophore with 3 mM sodium dodecyl sulfate provided the best detectability for all homologues. The reproducibility of the migration time and quantitative analysis can be improved by using tetraoctyl ammonium ion as an internal standard, giving the relative standard deviation (R.S.D.) less than 0.8% for the relative migration times, and 2.5-5.5% for the relative peak areas. A good linearity of CE analysis was obtained in the range of 1.0-20 microg/ml with r2 values of above 0.999. The analysis of cationic surfactants in commercial products of hair conditioners and fabric softeners was also performed. Electrospray mass spectrometric method was applied to evaluate the CE method, and the compatible results were obtained.

  7. Atmospheric concentrations of ammonia and ammonium at an agricultural site in the southeast United States

    Science.gov (United States)

    Robarge, Wayne P.; Walker, John T.; McCulloch, Ronald B.; Murray, George

    In this study, we present ˜1 yr (October 1998-September 1999) of 12-hour mean ammonia (NH 3), ammonium (NH 4+), hydrochloric acid (HCl), chloride (Cl -), nitrate (NO 3-), nitric acid (HNO 3), nitrous acid (HONO), sulfate (SO 42-), and sulfur dioxide (SO 2) concentrations measured at an agricultural site in North Carolina's Coastal Plain region. Mean gas concentrations were 0.46, 1.21, 0.54, 5.55, and 4.15 μg m -3 for HCl, HNO 3, HONO, NH 3, and SO 2, respectively. Mean aerosol concentrations were 1.44, 1.23, 0.08, and 3.37 μg m -3 for NH 4+, NO 3-, Cl -, and SO 42-, respectively. Ammonia, NH 4+, HNO 3, and SO 42- exhibit higher concentrations during the summer, while higher SO 2 concentrations occur during winter. A meteorology-based multivariate regression model using temperature, wind speed, and wind direction explains 76% of the variation in 12-hour mean NH 3 concentrations ( n=601). Ammonia concentration increases exponentially with temperature, which explains the majority of variation (54%) in 12-hour mean NH 3 concentrations. Dependence of NH 3 concentration on wind direction suggests a local source influence. Ammonia accounts for >70% of NH x (NH x=NH 3+NH 4+) during all seasons. Ammonium nitrate and sulfate aerosol formation does not appear to be NH 3 limited. Sulfate is primarily associated ammonium sulfate, rather than bisulfate, except during the winter when the ratio of NO 3--NH 4+ is ˜0.66. The annual average NO 3--NH 4+ ratio is ˜0.25.

  8. Enhanced water-solubility, antibacterial activity and biocompatibility upon introducing sulfobetaine and quaternary ammonium to chitosan.

    Science.gov (United States)

    Chen, Yuxiang; Li, Jianna; Li, Qingqing; Shen, Yuanyuan; Ge, Zaochuan; Zhang, Wenwen; Chen, Shiguo

    2016-06-05

    Chitosan (CS) has attracted much attention due to its good antibacterial activity and biocompatibility. However, CS is insoluble in neutral and alkaline aqueous solution, limiting its biomedical application to some extent. To circumvent this drawback, we have synthesized a novel N-quaternary ammonium-O-sulfobetaine-chitosan (Q3BCS) by introducing quaternary ammonium compound (QAC) and sulfobetaine, and its water-solubility, antibacterial activity and biocompatibility were evaluated compare to N-quaternary ammonium chitosan and native CS. The results showed that by introducing QAC, antibacterial activities and water-solubilities increase with degrees of substitution. The largest diameter zone of inhibition (DIZ) was improved from 0 (CS) to 15mm (N-Q3CS). And the water solution became completely transparent from pH 6.5 to pH 11; the maximal waters-solubility was improved from almost 0% (CS) to 113% at pH 7 (N-Q3CS). More importantly, by further introducing sulfobetaine, cell survival rate of Q3BCS increased from 30% (N-Q3CS) to 85% at 2000μg/ml, which is even greater than that of native CS. Furthermore, hemolysis of Q3BCS was dropped sharply from 4.07% (N-Q3CS) to 0.06%, while the water-solution and antibacterial activity were further improved significantly. This work proposes an efficient strategy to prepare CS derivatives with enhanced antibacterial activity, biocompatibility and water-solubility. Additionally, these properties can be finely tailored by changing the feed ratio of CS, glycidyl trimethylammonium chloride and NCO-sulfobetaine.

  9. Conversion of Hydrogen Sulfide in Coal Gases to Liquid Elemental Sulfur with Monolithic Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    K. C. Kwon

    2006-09-30

    Removal of hydrogen sulfide (H{sub 2}S) from coal gasifier gas and sulfur recovery are key steps in the development of Department of Energy's (DOE's) advanced power plants that produce electric power and clean transportation fuels with coal and natural gas. These plants will require highly clean coal gas with H{sub 2}S below 1 ppmv and negligible amounts of trace contaminants such as hydrogen chloride, ammonia, alkali, heavy metals, and particulate. The conventional method of sulfur removal and recovery employing amine, Claus, and tail-gas treatment is very expensive. A second generation approach developed under DOE's sponsorship employs hot-gas desulfurization (HGD) using regenerable metal oxide sorbents followed by Direct Sulfur Recovery Process (DSRP). However, this process sequence does not remove trace contaminants and is targeted primarily towards the development of advanced integrated gasification combined cycle (IGCC) plants that produce electricity (not both electricity and transportation fuels). There is an immediate as well as long-term need for the development of cleanup processes that produce highly clean coal gas for next generation power plants. To this end, a novel process is now under development at several research organizations in which the H{sub 2} in coal gas is directly oxidized to elemental sulfur over a selective catalyst. Such a process is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S In the Single-Step Sulfur Recovery Process (SSRP), the direct oxidation of H{sub 2}S to elemental sulfur in the presence of SO{sub 2} is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S. This direct oxidation process has the potential to produce a super clean coal gas more economically than both conventional amine-based processes and HGD/DSRP. The H{sub 2} and

  10. Conversion of Hydrogen Sulfide in Coal Gases to Liquid Elemental Sulfur with Monolithic Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    K. C. Kwon

    2006-09-30

    Removal of hydrogen sulfide (H{sub 2}S) from coal gasifier gas and sulfur recovery are key steps in the development of Department of Energy's (DOE's) advanced power plants that produce electric power and clean transportation fuels with coal and natural gas. These plants will require highly clean coal gas with H{sub 2}S below 1 ppmv and negligible amounts of trace contaminants such as hydrogen chloride, ammonia, alkali, heavy metals, and particulate. The conventional method of sulfur removal and recovery employing amine, Claus, and tail-gas treatment is very expensive. A second generation approach developed under DOE's sponsorship employs hot-gas desulfurization (HGD) using regenerable metal oxide sorbents followed by Direct Sulfur Recovery Process (DSRP). However, this process sequence does not remove trace contaminants and is targeted primarily towards the development of advanced integrated gasification combined cycle (IGCC) plants that produce electricity (not both electricity and transportation fuels). There is an immediate as well as long-term need for the development of cleanup processes that produce highly clean coal gas for next generation power plants. To this end, a novel process is now under development at several research organizations in which the H{sub 2} in coal gas is directly oxidized to elemental sulfur over a selective catalyst. Such a process is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S In the Single-Step Sulfur Recovery Process (SSRP), the direct oxidation of H{sub 2}S to elemental sulfur in the presence of SO{sub 2} is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S. This direct oxidation process has the potential to produce a super clean coal gas more economically than both conventional amine-based processes and HGD/DSRP. The H{sub 2} and

  11. 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...... sulfate were obtained from experiments in a fast heating rate thermogravimetric analyzer. The yields of SO2 and SO3 from the decomposition were investigated in a tube reactor at 600–900 °C, revealing a constant distribution of about 15% SO2 and 85% SO3 from aluminum sulfate decomposition and a temperature......-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...

  12. Development of stable monolithic wide-field Michelson interferometers.

    Science.gov (United States)

    Wan, Xiaoke; Ge, Jian; Chen, Zhiping

    2011-07-20

    Bulk wide-field Michelson interferometers are very useful for high precision applications in remote sensing and astronomy. A stable monolithic Michelson interferometer is a key element in high precision radial velocity (RV) measurements for extrasolar planets searching and studies. Thermal stress analysis shows that matching coefficients of thermal expansion (CTEs) is a critical requirement for ensuring interferometer stability. This requirement leads to a novel design using BK7 and LAK7 materials, such that the monolithic interferometer is free from thermal distortion. The processes of design, fabrication, and testing of interferometers are described in detail. In performance evaluations, the field angle is typically 23.8° and thermal sensitivity is typically -2.6×10(-6)/°C near 550 nm, which corresponds to ∼800 m/s/°C in the RV scale. Low-cost interferometer products have been commissioned in multiple RV instruments, and they are producing high stability performance over long term operations.

  13. Design and Testing of Prototypic Elements Containing Monolithic Fuel

    Energy Technology Data Exchange (ETDEWEB)

    N.E. Woolstenhulme; M.K. Meyer; D.M. Wachs

    2011-10-01

    The US fuel development team has performed numerous irradiation tests on small to medium sized specimens containing low enriched uranium fuel designs. The team is now focused on qualification and demonstration of the uranium-molybdenum Base Monolithic Design and has entered the next generation of testing with the design and irradiation of prototypic elements which contain this fuel. The designs of fuel elements containing monolithic fuel, such as AFIP-7 (which is currently under irradiation) and RERTR-FE (which is currently under fabrication), are appropriate progressions relative to the technology life cycle. The culmination of this testing program will occur with the design, fabrication, and irradiation of demonstration products to include the base fuel demonstration and design demonstration experiments. Future plans show that design, fabrication, and testing activities will apply the rigor needed for a demonstration campaign.

  14. Development of stable monolithic wide-field Michelson interferometers

    Science.gov (United States)

    Wan, Xiaoke; Ge, Jian; Chen, Zhiping

    2011-07-01

    Bulk wide-field Michelson interferometers are very useful for high precision applications in remote sensing and astronomy. A stable monolithic Michelson interferometer is a key element in high precision radial velocity (RV) measurements for extrasolar planets searching and studies. Thermal stress analysis shows that matching coefficients of thermal expansion (CTEs) is a critical requirement for ensuring interferometer stability. This requirement leads to a novel design using BK7 and LAK7 materials, such that the monolithic interferometer is free from thermal distortion. The processes of design, fabrication, and testing of interferometers are described in detail. In performance evaluations, the field angle is typically 23.8° and thermal sensitivity is typically -2.6×10-6/° C near 550nm, which corresponds to ˜800m/s/°C in the RV scale. Low-cost interferometer products have been commissioned in multiple RV instruments, and they are producing high stability performance over long term operations.

  15. Affinity Monolith-Integrated Microchips for Protein Purification and Concentration.

    Science.gov (United States)

    Gao, Changlu; Sun, Xiuhua; Wang, Huaixin; Qiao, Wei; Hu, Bo

    2016-01-01

    Affinity chromatography is a valuable method to purify and concentrate minute amount of proteins. Monoliths with epoxy groups for affinity immobilization were prepared by direct in-situ photopolymerization of glycidyl methacrylate and ethylene glycol dimethacrylate in porogenic solvents consisting of 1-dodecanol and cyclohexanol. By integrating affinity monoliths onto a microfluidic system, targeted biomolecules can be captured and retained on affinity column, while other biomolecules having no specific interactions toward the immobilized ligands flow through the microchannel. Therefore, proteins which remain on the affinity column are purified and concentrated, and then eluted by appropriate solutions and finally, separated by microchip capillary electrophoresis. This integrated microfluidic device has been applied to the purification and separation of specific proteins (FITC-labeled human serum albumin and IgG) in a mixture.

  16. From 1D to 3D - macroscopic nanowire aerogel monoliths

    Science.gov (United States)

    Cheng, Wei; Rechberger, Felix; Niederberger, Markus

    2016-07-01

    Here we present a strategy to assemble one-dimensional nanostructures into a three-dimensional architecture with macroscopic size. With the assistance of centrifugation, we successfully gel ultrathin W18O49 nanowires with diameters of 1 to 2 nm and aspect ratios larger than 100 into 3D networks, which are transformed into monolithic aerogels by supercritical drying.Here we present a strategy to assemble one-dimensional nanostructures into a three-dimensional architecture with macroscopic size. With the assistance of centrifugation, we successfully gel ultrathin W18O49 nanowires with diameters of 1 to 2 nm and aspect ratios larger than 100 into 3D networks, which are transformed into monolithic aerogels by supercritical drying. Electronic supplementary information (ESI) available: Experimental details, SEM and TEM images, and digital photographs. See DOI: 10.1039/c6nr04429h

  17. Material Engineering for Monolithic Semiconductor Mode-Locked Lasers

    DEFF Research Database (Denmark)

    Kulkova, Irina

    application in MLLs. Improved QW laser performance was demonstrated using the asymmetric barrier layer approach. The analysis of the gain characteristics showed that the high population inversion beneficial for noise reduction cannot be achieved for 10 GHz QW MLLs and would have required lowering the modal......This thesis is devoted to the materials engineering for semiconductor monolithic passively mode-locked lasers (MLLs) as a compact energy-efficient source of ultrashort optical pulses. Up to the present day, the achievement of low-noise sub-picosecond pulse generation has remained a challenge...... quality and low internal reflection compatible with the severe requirements of monolithic MLLs. Experimental characterization of static material parameters of the fabricated devices revealed QW-like gain behavior of a self-assembled InAs/InP QD material and low internal efficiency which limited its...

  18. Fabrication and characterization of monolithic solid oxide fuel cells

    Science.gov (United States)

    Minh, N. Q.; Horne, C. R.; Liu, F. S.; Moffatt, D. M.; Staszak, P. R.

    The monolithic solid oxide fuel cell (MSOFC) is an all-ceramic structure in which cell components are configured in a compact corrugated array. The MSOFC shows promise for use in a wide range of sizes (kilowatt to megawatt) and a broad spectrum of applications (electric utility, cogeneration, on-site, and aerospace power). A process based on the tape calendering technique is being developed for the fabrication of the MSOFC. MSOFC single cells have been fabricated by this process without cracking or delamination. Stacks of various sizes have been formed and processed to demonstrate fabricability of the monolithic structure. Extensive physical, chemical, electrical, and electrochemical characterization of fabricated samples has been carried out to confirm the required properties of each cell component. The characterization results reported have been used to support material and fabrication improvements.

  19. Low-bandgap, monolithic, multi-bandgap, optoelectronic devices

    Science.gov (United States)

    Wanlass, Mark W.; Carapella, Jeffrey J.

    2014-07-08

    Low bandgap, monolithic, multi-bandgap, optoelectronic devices (10), including PV converters, photodetectors, and LED's, have lattice-matched (LM), double-heterostructure (DH), low-bandgap GaInAs(P) subcells (22, 24) including those that are lattice-mismatched (LMM) to InP, grown on an InP substrate (26) by use of at least one graded lattice constant transition layer (20) of InAsP positioned somewhere between the InP substrate (26) and the LMM subcell(s) (22, 24). These devices are monofacial (10) or bifacial (80) and include monolithic, integrated, modules (MIMs) (190) with a plurality of voltage-matched subcell circuits (262, 264, 266, 270, 272) as well as other variations and embodiments.

  20. 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.

  1. 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%.

  2. [Headspace GC/MS analysis of residual vinyl chloride and vinylidene chloride in polyvinyl chloride and polyvinylidene chloride products].

    Science.gov (United States)

    Ohno, Hiroyuki; Mutsuga, Motoh; Kawamura, Yoko; Suzuki, Masako; Aoyama, Taiki

    2005-02-01

    A headspace GC/MS analysis method for the simultaneous determination of residual vinyl chloride (VC) and vinylidene chloride (VDC) in polyvinyl chloride (PVC) and polyvinylidene chloride (PVDC) products was developed. A test sample was swelled overnight with N,N-dimethylacetamide in a sealed vial. The vial was incubated for 1 hour at 90 degrees C, then the headspace gas was analyzed by GC/MS using a PLOT capillary column. The recoveries from spiked PVC and PVDC samples were 90.0-112.3% for VC and 85.2-108.3% for VDC. The determination limits were 0.01 microg/g for VC and 0.06/microg/g for VDC, respectively. By this method, VC was detected in two PVC water supply pipes at the levels of 0.61 and 0.01 microg/g. On the other hand, VC and VDC were not detected in any of the food container-packages or toys tested.

  3. 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.

  4. 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

  5. Clinical assessment of enamel wear caused by monolithic zirconia crowns.

    Science.gov (United States)

    Stober, T; Bermejo, J L; Schwindling, F S; Schmitter, M

    2016-08-01

    The purpose of this study was to measure enamel wear caused by antagonistic monolithic zirconia crowns and to compare this with enamel wear caused by contralateral natural antagonists. Twenty monolithic zirconia full molar crowns were placed in 20 patients. Patients with high activity of the masseter muscle at night (bruxism) were excluded. For analysis of wear, vinylpolysiloxane impressions were prepared after crown incorporation and at 6-, 12-, and 24-month follow-up. Wear of the occlusal contact areas of the crowns, of their natural antagonists, and of two contralateral natural antagonists (control teeth) was measured by use of plaster replicas and a 3D laser-scanning device. Differences of wear between the zirconia crown antagonists and the control teeth were investigated by means of two-sided paired Student's t-tests and linear regression analysis. After 2 years, mean vertical loss was 46 μm for enamel opposed to zirconia, 19-26 μm for contralateral control teeth and 14 μm for zirconia crowns. Maximum vertical loss was 151 μm for enamel opposed to zirconia, 75-115 μm for control teeth and 60 μm for zirconia crowns. Statistical analysis revealed significant differences between wear of enamel by zirconia-opposed teeth and by control teeth. Gender, which significantly affected wear, was identified as a possible confounder. Monolithic zirconia crowns generated more wear of opposed enamel than did natural teeth. Because of the greater wear caused by other dental ceramics, the use of monolithic zirconia crowns may be justified.

  6. Applications of monolithic fiber interferometers and actively controlled fibers

    OpenAIRE

    Rugeland, Patrik

    2013-01-01

    The objective of this thesis was to develop applications of monolithic fiber devices and actively controlled fibers. A special twin-core fiber known as a ‘Gemini’ fiber was used to construct equal arm-length fiber interferometers, impervious to temperature and mechanical perturbations. A broadband add/drop multiplexer was constructed by inscribing fiber Bragg gratings in the arms of a Gemini Mach-Zehnder interferometer. A broadband interferometric nanosecond switch was constructed from a micr...

  7. A Distributed Model of Four-Port Monolithic Transformer

    OpenAIRE

    Lee, Dong Ho; Ko, Sangsoo; Jeon, Sang-Hoon; Park, Jae-Woo; Hong, Songcheol

    2004-01-01

    This paper deals with modeling of a monolithic spiral transformer. The transformer is designed and fabricated as a symmetrical octagonal spiral structure using two-metal layer process on GaAs substrate for input balun applications of 2 GHz and 5 GHz push-pull power amplifiers. A distributed model of the transformer is developed to fit in wide frequency range with four ports. The model includes the skin effect which describes increase in series resistance with frequency. Six different se...

  8. Advanced on-chip divider for monolithic microwave VCO's

    Science.gov (United States)

    Peterson, Weddell C.

    1989-01-01

    High frequency division on a monolithic circuit is a critical technology required to significantly enhance the performance of microwave and millimeter-wave phase-locked sources. The approach used to meet this need is to apply circuit design practices which are essentially 'microwave' in nature to the basically 'digital' problem of high speed division. Following investigation of several promising circuit approaches, program phase 1 culminated in the design and layout of an 8.5 GHz (Deep Space Channel 14) divide by four circuit based on a dynamic mixing divider circuit approach. Therefore, during program phase 2, an 8.5 GHz VCO with an integral divider which provides a phase coherent 2.125 GHz reference signal for phase locking applications was fabricated and optimized. Complete phase locked operation of the monolithic GaAs devices (VCO, power splitter, and dynamic divider) was demonstrated both individually and as an integrated unit. The fully functional integrated unit in a suitable test fixture was delivered to NASA for engineering data correlation. Based on the experience gained from this 8.5 GHz super component, a monolithic GaAs millimeter-wave dynamic divider for operation with an external VCO was also designed, fabricated, and characterized. This circuit, which was also delivered to NASA, demonstrated coherent division by four at an input frequency of 24.3 GHz. The high performance monolithic microwave VCO with a coherent low frequency reference output described in this report and others based on this technology will greatly benefit advanced communications systems in both the DoD and commercial sectors. Signal processing and instrumentation systems based on phase-locking loops will also attain enhanced performance at potentially reduced cost.

  9. Advanced on-chip divider for monolithic microwave VCO's

    Science.gov (United States)

    Peterson, Weddell C.

    1989-05-01

    High frequency division on a monolithic circuit is a critical technology required to significantly enhance the performance of microwave and millimeter-wave phase-locked sources. The approach used to meet this need is to apply circuit design practices which are essentially 'microwave' in nature to the basically 'digital' problem of high speed division. Following investigation of several promising circuit approaches, program phase 1 culminated in the design and layout of an 8.5 GHz (Deep Space Channel 14) divide by four circuit based on a dynamic mixing divider circuit approach. Therefore, during program phase 2, an 8.5 GHz VCO with an integral divider which provides a phase coherent 2.125 GHz reference signal for phase locking applications was fabricated and optimized. Complete phase locked operation of the monolithic GaAs devices (VCO, power splitter, and dynamic divider) was demonstrated both individually and as an integrated unit. The fully functional integrated unit in a suitable test fixture was delivered to NASA for engineering data correlation. Based on the experience gained from this 8.5 GHz super component, a monolithic GaAs millimeter-wave dynamic divider for operation with an external VCO was also designed, fabricated, and characterized. This circuit, which was also delivered to NASA, demonstrated coherent division by four at an input frequency of 24.3 GHz. The high performance monolithic microwave VCO with a coherent low frequency reference output described in this report and others based on this technology will greatly benefit advanced communications systems in both the DoD and commercial sectors. Signal processing and instrumentation systems based on phase-locking loops will also attain enhanced performance at potentially reduced cost.

  10. Dynamic response of monolithic and laminate/particulate reactive mixtures

    OpenAIRE

    Wei, Chung-Ting

    2011-01-01

    Two dynamic compression methods were applied to a monolithic metal and reactive mixtures to investigate their responses: (a) Dynamic experiments using a split Hopkinson pressure bar were applied to reactive mixtures densified by explosive consolidation in order to establish their mechanical response and failure mechanisms. (b) Laser compression and release, which can impart high stresses, up to hundreds GPa, in times of nanoseconds and fractions thereof, was applied to establish the spalling ...

  11. 21 CFR 173.375 - Cetylpyridinium chloride.

    Science.gov (United States)

    2010-04-01

    ... CONSUMPTION Specific Usage Additives § 173.375 Cetylpyridinium chloride. Cetylpyridinium chloride (CAS Reg. No... Nutrition's Library, Food and Drug Administration, 5100 Paint Branch Pkwy., College Park, MD 20740, or...

  12. 21 CFR 73.1298 - Ferric ammonium ferrocyanide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Ferric ammonium ferrocyanide. 73.1298 Section 73.1298 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL...) Identity. (1) The color additive ferric ammonium ferrocyanide is the blue pigment obtained by...

  13. 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

  14. Purification of monoclonal antibodies, IgG1, from cell culture supernatant by use of metal chelate convective interaction media monolithic columns.

    Science.gov (United States)

    Rajak, Poonam; Vijayalakshmi, M A; Jayaprakash, N S

    2012-12-01

    Monoclonal antibodies (MAbs) have diverse applications in diagnostics and therapeutics. The recent advancement in hybridoma technology for large-scale production of MAbs in bioreactors demands rapid and efficient purification methods. Conventional affinity purification systems have drawbacks of low flow rates and denaturation of antibodies owing to harsh elution conditions. Here, we attempted purification of MAbs by use of a high-throughput metal-chelate methacrylate monolithic system. Monolithic macroporous convective interaction media-iminodiacetate (CIM-IDA) disks immobilized with four different metal ions (Cu²⁺, Ni²⁺, Zn²⁺ and Co²⁺) were used and evaluated for purification of anti-human serum albumin IgG1 mouse MAbs from cell culture supernatant after precipitation with 50% ammonium sulfate. Elution with 10 mM imidazole in the equilibration buffer (25 mM MMA = MOPS (Morpholino propane sulfonic acid) + MES (Morpholino ethane sulfonic acid) + Acetate + 0.5 M NaCl, pH 7.4) resulted in a purification of 25.7 ± 2.9-fold and 32.5 ± 2.6-fold in experiments done using Zn²⁺ and Co²⁺ metal ions, respectively. The highest recovery of 85.4 ± 1.0% was obtained with a CIM-IDA-Zn(II) column. SDS-PAGE, ELISA and immuno-blot showed that the antibodies recovered were pure, with high antigen-binding efficiency. Thus, metal chelate CIM monoliths could be a potential alternative to conventional systems for fast and efficient purification of MAbs from the complex cell culture supernatant.

  15. Monolithic pixels on moderate resistivity substrate and sparsifying readout architecture

    CERN Document Server

    Giubilato, P; Snoeys, W; Bisello, D; Marchioro, A; Battaglia, M; Demaria, L; Mansuy, S C; Pantano, D; Rousset, J; Mattiazzo, S; Kloukinas, K; Potenza, A; Ikemoto, Y; Rivetti, A; Chalmet, P; Mugnier, H; Silvestrin, L

    2013-01-01

    The LePix projects aim realizing a new generation monolithic pixel detectors with improved performances at lesser cost with respect to both current state of the art monolithic and hybrid pixel sensors. The detector is built in a 90 nm CMOS process on a substrate of moderate resistivity. This allows charge collection by drift while maintaining the other advantages usually offered by MAPS, like having a single piece detector and using a standard CMOS production line. The collection by drift mechanism, coupled to the low capacitance design of the collecting node made possible by the monolithic approach, provides an excellent signal to noise ratio straight at the pixel cell together with a radiation tolerance far superior to conventional un-depleted MAPS. The excellent signal-to-noise performance is demonstrated by the device ability to separate the 6 keV Fe-55 double peak at room temperature. To achieve high granularity (10-20 mu m pitch pixels) over large detector areas maintaining high readout speed, a complet...

  16. Strong cation exchange monoliths for HPLC by Reactive Gelation.

    Science.gov (United States)

    Brand, Bastian; Krättli, Martin; Storti, Giuseppe; Morbidelli, Massimo

    2011-08-01

    Polymeric monolithic stationary phases for HPLC can be produced by Reactive Gelation. Unlike the conventional method of using porogens, such novel process consists of a number of separate steps, thus enabling a better control of the quality of the final material. A suspension of polymer nanoparticles in water is produced and subsequently swollen with hydrophobic monomers. The particles are then destabilised (usually by salt addition) to make them aggregate into a large percolating structure, the so-called monolith. Finally, the added monomer can then be polymerised to harden the structure. In this work, a polystyrene latex is used as the base material and functionalised by introduction of epoxide groups on the surface and subsequent reaction to sulphonic acid groups, yielding a SO3(-) density of 0.7 mmol/g dry material. Morphological investigations show 54% porosity made of 300 nm large pores. Van Deemter measurements of a large protein show no practical influence of diffusion limitations on the plate number. Finally, a preliminary separation of a test protein mixture is shown, demonstrating the potential of using ion-exchange chromatography on Reactive Gelation monoliths.

  17. Controlled porosity monolithic material as permselective ion exchange membranes.

    Science.gov (United States)

    Huang, Xiaojia; Dasgupta, Purnendu K

    2011-03-18

    Ion exchange membranes (IEMs) are used in a variety of analytical devices, including suppressors, eluent generators and other components used in ion chromatography. Such membranes are flexible and undergo substantial dimensional changes on hydration. Presently the push to miniaturization continues; a resurgent interest in open tubular ion chromatography requires microscale adaptation of these components. Incorporating IEMs in microscale devices is difficult. Although both macroporous and microporous ion exchange materials have been made for use as chromatographic packing, ion exchange material used as membranes are porous only on a molecular scale. Because such pores have vicinal ion exchange sites, ions of the same charge sign as those of the fixed sites are excluded from the IEMs. Monolithic polymers, including ion exchangers derived therefrom, are presently extensively used. When used in a separation column, such a monolithic structure contains an extensively connected porous network. We show here that by controlling the amount of porogen added during the synthesis of monolithic polymers derived from ethylene dimethacrylate - glycidyl methacrylate, which are converted to an anion exchanger by treatment with trimethylamine, it is possible to obtain rigid ion exchange polymers that behave like IEMs and allow only one charge type of ions to pass through, i.e., are permselective. We demonstrate successful open tubular cation chromatography suppressor performance.

  18. Monolithic pixels on moderate resistivity substrate and sparsifying readout architecture

    Science.gov (United States)

    Giubilato, P.; Battaglia, M.; Bisello, D.; Caselle, M.; Chalmet, P.; Demaria, L.; Ikemoto, Y.; Kloukinas, K.; Mansuy, S. C.; Mattiazzo, S.; Marchioro, A.; Mugnier, H.; Pantano, D.; Potenza, A.; Rivetti, A.; Rousset, J.; Silvestrin, L.; Snoeys, W.

    2013-12-01

    The LePix projects aim realizing a new generation monolithic pixel detectors with improved performances at lesser cost with respect to both current state of the art monolithic and hybrid pixel sensors. The detector is built in a 90 nm CMOS process on a substrate of moderate resistivity. This allows charge collection by drift while maintaining the other advantages usually offered by MAPS, like having a single piece detector and using a standard CMOS production line. The collection by drift mechanism, coupled to the low capacitance design of the collecting node made possible by the monolithic approach, provides an excellent signal to noise ratio straight at the pixel cell together with a radiation tolerance far superior to conventional un-depleted MAPS. The excellent signal-to-noise performance is demonstrated by the device ability to separate the 6 keV 55Fe double peak at room temperature. To achieve high granularity (10-20 μm pitch pixels) over large detector areas maintaining high readout speed, a completely new compressing architecture has been devised. This architecture departs from the mainstream hybrid pixel sparsification approach, which uses in-pixel logic to reduce data, by using topological compression to minimize pixel area and power consumption.

  19. UPDATE ON MECHANICAL ANALYSIS OF MONOLITHIC FUEL PLATES

    Energy Technology Data Exchange (ETDEWEB)

    D. E. Burkes; F. J. Rice; J.-F. Jue; N. P. Hallinan

    2008-03-01

    Results on the relative bond strength of the fuel-clad interface in monolithic fuel plates have been presented at previous RRFM conferences. An understanding of mechanical properties of the fuel, cladding, and fuel / cladding interface has been identified as an important area of investigation and quantification for qualification of monolithic fuel forms. Significant progress has been made in the area of mechanical analysis of the monolithic fuel plates, including mechanical property determination of fuel foils, cladding processed by both hot isostatic pressing and friction bonding, and the fuel-clad composite. In addition, mechanical analysis of fabrication induced residual stress has been initiated, along with a study to address how such stress can be relieved prior to irradiation. Results of destructive examinations and mechanical tests are presented along with analysis and supporting conclusions. A brief discussion of alternative non-destructive evaluation techniques to quantify not only bond quality, but also bond integrity and strength, will also be provided. These are all necessary steps to link out-of-pile observations as a function of fabrication with in-pile behaviours.

  20. A Ferrite LTCC-Based Monolithic SIW Phased Antenna Array

    KAUST Repository

    Nafe, Ahmed

    2016-11-17

    In this work, we present a novel configuration for realizing monolithic SIW-based phased antenna arrays using Ferrite LTCC technology. Unlike the current common schemes for realizing SIW phased arrays that rely on surface-mount component (p-i-n diodes, etc) for controlling the phase of the individual antenna elements, here the phase is tuned by biasing of the ferrite filling of the SIW. This approach eliminates the need for mounting of any additional RF components and enables seamless monolithic integration of phase shifters and antennas in SIW technology. As a proof of concept, a two-element slotted SIW-based phased array is designed, fabricated and measured. The prototype exhibits a gain of 4.9 dBi at 13.2 GHz and a maximum E-plane beam-scanning of 28 degrees using external windings for biasing the phase shifters. Moreover, the array can achieve a maximum beam-scanning of 19 degrees when biased with small windings that are embedded in the package. This demonstration marks the first time a fully monolithic SIW-based phased array is realized in Ferrite LTCC technology and paves the way for future larger-size implementations.

  1. Preparing silica aerogel monoliths via a rapid supercritical extraction method.

    Science.gov (United States)

    Carroll, Mary K; Anderson, Ann M; Gorka, Caroline A

    2014-02-28

    A procedure for the fabrication of monolithic silica aerogels in eight hours or less via a rapid supercritical extraction process is described. The procedure requires 15-20 min of preparation time, during which a liquid precursor mixture is prepared and poured into wells of a metal mold that is placed between the platens of a hydraulic hot press, followed by several hours of processing within the hot press. The precursor solution consists of a 1.0:12.0:3.6:3.5 x 10(-3) molar ratio of tetramethylorthosilicate (TMOS):methanol:water:ammonia. In each well of the mold, a porous silica sol-gel matrix forms. As the temperature of the mold and its contents is increased, the pressure within the mold rises. After the temperature/pressure conditions surpass the supercritical point for the solvent within the pores of the matrix (in this case, a methanol/water mixture), the supercritical fluid is released, and monolithic aerogel remains within the wells of the mold. With the mold used in this procedure, cylindrical monoliths of 2.2 cm diameter and 1.9 cm height are produced. Aerogels formed by this rapid method have comparable properties (low bulk and skeletal density, high surface area, mesoporous morphology) to those prepared by other methods that involve either additional reaction steps or solvent extractions (lengthier processes that generate more chemical waste).The rapid supercritical extraction method can also be applied to the fabrication of aerogels based on other precursor recipes.

  2. 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 ...

  3. 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.

  4. Monolithic poly (SPE-co-BVPE) capillary columns as a novel hydrophilic interaction liquid chromatography stationary phase for the separation of polar analytes.

    Science.gov (United States)

    Foo, Hsiao Ching; Heaton, James; Smith, Norman W; Stanley, Shawn

    2012-10-15

    A novel hydrophilic interaction liquid chromatography (HILIC) stationary phase was prepared by the co-polymerisation of zwitterionic N,N'-dimethyl-N-methacryloxyethyl-N-(3-sulfopropyl) ammonium betaine (SPE) and the crosslinker 1,2-bis(p-vinylphenyl) ethane (BVPE) in the presence of the porogens, toluene and methanol. Monolithic columns were produced by carrying out the α,α'-azoisobutyronitrile (AIBN) initiated reaction for 1, 2, 4, 8 and 12 h inside a 200 μm i.d. fused silica capillary at 75°C (water bath). The optimum polymerisation time was shown to be 2 h, as this resulted in good porosity, due to enlarged flow-channels and the presence of a higher proportion of mesopores provided a relatively larger surface area than the other columns. The chromatographic properties of the optimised poly (SPE-co-BVPE) monolithic column were evaluated with test mixtures containing both basic and neutral compounds in the HILIC gradient separation mode. This produced relatively sharp peaks (average peak width at half height=0.1 min) with average asymmetry factors of 1.4 and baseline resolution was obtained for all the compounds. Using the isocratic separation of the test mixture, the number of theoretical plates (N) per metre calculated was between 26,888 and 35,930 by using average values obtained for triplicate injections of the compounds thiourea, toluene and acrylamide.

  5. 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.

  6. Photoinitiated grafting of porous polymer monoliths and thermoplastic polymers for microfluidic devices

    Science.gov (United States)

    Frechet, Jean M. J.; Svec, Frantisek; Rohr, Thomas

    2008-10-07

    A microfluidic device preferably made of a thermoplastic polymer that includes a channel or a multiplicity of channels whose surfaces are modified by photografting. The device further includes a porous polymer monolith prepared via UV initiated polymerization within the channel, and functionalization of the pore surface of the monolith using photografting. Processes for making such surface modifications of thermoplastic polymers and porous polymer monoliths are set forth.

  7. Preparation and characterization of polystyrene-based monolith with ordered macroporous structure

    Institute of Scientific and Technical Information of China (English)

    Quan Zhou Wu; Jian Feng He; Ji Ming Ou

    2012-01-01

    In this paper,polystyrene-based monoliths with highly ordered macroporous structure were synthesized by using SiO2 colloidal crystal as template.SEM observation shows that the macropores are highly ordered and are interconnected by small windows.The BET surface area of PS monolith is about 36.17 m2/g.The polymer monoliths can resist 5 MPa pressure,showing high mechanical and compressive strength.

  8. Application of Monolithic Zirconia Ceramics in Dental Practice: A Case History Report.

    Science.gov (United States)

    Kim, Hee-Kyung; Kim, Sung-Hun; Lee, Jai-Bong; Han, Jung-Suk; Yeo, In-Sung

    2016-01-01

    Monolithic zirconia restorations increasingly have been used in dental practice in recent years and demonstrate superior mechanical performance compared with porcelain-veneered zirconia restorations. Recent advances in manufacturing technology have made possible the fabrication of translucent monolithic zirconia ceramics. This case report describes three clinical examples of monolithic zirconia fixed dental prostheses being used in the anterior and posterior regions and exhibiting acceptable esthetic results.

  9. 21 CFR 184.1426 - Magnesium chloride.

    Science.gov (United States)

    2010-04-01

    ... mineral bischofite. It is prepared by dissolving magnesium oxide, hydroxide, or carbonate in aqueous... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Magnesium chloride. 184.1426 Section 184.1426 Food... Specific Substances Affirmed as GRAS § 184.1426 Magnesium chloride. (a) Magnesium chloride (MgC12·6H2O,...

  10. Cystic Fibrosis (CF): Chloride Sweat Test

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old Cystic Fibrosis (CF) Chloride Sweat Test KidsHealth > For Parents > Cystic Fibrosis (CF) Chloride Sweat Test Print A A A ... It Is A chloride sweat test helps diagnose cystic fibrosis (CF) , an inherited disorder that makes kids sick ...

  11. 75 FR 33824 - Barium Chloride From China

    Science.gov (United States)

    2010-06-15

    ... COMMISSION Barium Chloride From China Determination On the basis of the record\\1\\ developed in the subject... order on barium chloride from China would be likely to lead to continuation or recurrence of material... Barium Chloride from China: Investigation No. 731-TA-149 (Third Review). By order of the...

  12. 75 FR 19657 - Barium Chloride From China

    Science.gov (United States)

    2010-04-15

    ... 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 review... revocation of the antidumping duty order on barium chloride from China would be likely to lead...

  13. 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...

  14. [Qualitative and quantitative analysis of ammonium salts of hexamethylenetetramine and 1,10-phenanthroline].

    Science.gov (United States)

    Bernatoniene, Rūta; Stankeviciene, Laimute; Stankevicius, Antanas; Janusiene, Laima

    2003-01-01

    By use of chemical and physicochemical methods the qualitative and quantitative analysis of bacteriostatic agents N-carbamoylmethylhexamethylenetetraamonium chloride (U-77) and 1-propyl-1,10-phenanthrolinium iodide (X-50) was carried out. The color reactions of these salts with various agents, e. g., concentrated acids, precipitants, oxidizers, indicators, ninhydrin, salts of heavy metals were assesssed. Some characteristic color reactions were found for analysis of quaternary ammonium salts. Experimental results indicate that interaction of N-carbamoylmethyhexamethylenetetraammonium chloride with silver nitrate leads to precipitate of the free silver in the form of a mirror under the proper conditions. It is a result of degradation of hexamethylenetetramine to formaldehyde and its oxidation, which is accompanied by reduction of silver ion to free silver. By use of thin-layer chromatography and ultraviolet spectrophotometry the physicochemical properties of compounds were tested. The suitability of qualitative methods, such as argentometry, mercurimetry, iodometry, extraction photometric analysis was detected. The results suggest, that the most suitable and precise method is argentometry.

  15. Determination of Dequalinium Chloride and Glycyrrhizin in Compound Dequalinium Chloride Spray by HPLC%复方地喹氯铵喷雾剂中二组分的HPLC测定

    Institute of Scientific and Technical Information of China (English)

    刘克江; 肖仰

    2001-01-01

    Dequalinium chloride and glycyrrhizin in compound dequalinium chloride spray were determined by HPLC, using a CLC C18 column, 6.8 mmol/L sodium hexanesulphonate solution in methanol-15.4% ammonium acetate solution-glacial acetic acid (55∶33∶1) as the mobile phase, at the detection wavelength of 250 nm. The average recoveries for dequalinium chloride and glycyrrhizin, were 100.35% (RSD 0.80%) and 99.75% (RSD 0.33%), respectively.%采用HPLC法,用C18柱测定复方地喹氯铵喷雾剂中地喹氯铵和甘草酸的含量。二组分的回收率分别为100.35%、99.75%;RSD分别为0.80%、0.33%。

  16. Comparison of perfusion media and monoliths for protein and virus-like particle chromatography.

    Science.gov (United States)

    Wu, Yige; Abraham, Dicky; Carta, Giorgio

    2016-05-20

    Structural and performance characteristics of perfusion chromatography media (POROS HS 20 and 50) and those of a polymethacrylate monolith (CIM SO3-1 tube monolith column) are compared for protein and virus-like particle chromatography using 1mL columns. Axial flow columns are used for POROS while the monolith has a radial flow configuration, which provides comparable operating pressures. The POROS beads contain a bimodal distribution of pore sizes, some as large as 0.5μm, which allow a small fraction of the mobile phase to flow within the particles, while the monolith contains 1-2μm flow channels. For proteins (lysozyme and IgG), the dynamic binding capacity of the POROS columns is more than twice that of the monolith at longer residence times. While the DBC of the POROS HS 50 column decreases at shorter residence times, the DBC of the POROS HS 20 column for IgG remains nearly twice that of the monolith at residence times at least as low as 0.2min as a result of intraparticle convection. Protein recoveries are comparable for all three columns. For VLPs, however, the eluted peaks are broader and recovery is lower for the monolith than for the POROS columns and is dependent on the direction of flow in the monolith, which is attributed to denser layer observed by SEM at the inlet surface of the monolith that appears to trap VLPs when loading in the normal flow direction.

  17. 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.

  18. Receptor model source attributions for Utah’s Salt Lake City airshed and the impacts of wintertime secondary ammonium nitrate and ammonium chloride aerosol.

    Science.gov (United States)

    Communities along Utah’s Wasatch Front are currently developing strategies to reduce daily average PM2.5 levels to below National Ambient Air Quality Standards during wintertime, persistent, multi-day stable atmospheric conditions or cold-air pools. Speciated PM2.5 data from the ...

  19. 76 FR 49449 - Continuation of Antidumping Duty Order on Solid Fertilizer Grade Ammonium Nitrate From the...

    Science.gov (United States)

    2011-08-10

    ... Nitrate From the Russian Federation AGENCY: Import Administration, International Trade Administration... duty investigation on solid fertilizer grade ammonium nitrate (``ammonium nitrate'') from the Russian... and the ITC instituted a second sunset review of the ammonium nitrate suspended investigation....

  20. 76 FR 23569 - Termination of the Suspension Agreement on Solid Fertilizer Grade Ammonium Nitrate From the...

    Science.gov (United States)

    2011-04-27

    ... Nitrate From the Russian Federation and Notice of Antidumping Duty Order AGENCY: Import Administration... (``AD'') Investigation on Solid Fertilizer Grade Ammonium Nitrate from the Russian Federation (``the... determine whether imports of solid fertilizer grade ammonium nitrate (``ammonium nitrate'') from Russia...

  1. 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).

  2. 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.

  3. Study on All-Solid-State Chloride Sensor Based on Tin Oxide/Indium Tin Oxide Glass

    Science.gov (United States)

    Cheng, Jui-Fu; Chou, Jung-Chuan; Sun, Tai-Ping; Hsiung, Shen-Kan; Kao, Hui-Ling

    2011-03-01

    An all-solid-state chloride electrode based on a tin oxide (SnO2)/indium tin oxide (ITO) glass was developed in this study. The sensing membrane of the electrode was prepared by mixing poly(vinyl chloride) (PVC), bis(2-ethylhexyl) sebacate (DOS), [4,5-dimethy-l-3,6-bis(dodecyloxy)-1,2-phenylene] bis(mercury chloride) (ETH9033), and tridodecylmethyl ammonium chloride (TDDMACl). The mixed solution was mixed with tetrahydrofuran (THF), and then dropped on the sensing window of SnO2/ITO glass. According to the experimental results, the optimal weight ratio were PVC:DOS:ETH9033:TDDMACl=33:66:2:5. At this optimum weight ratio, the sensitivity was 54 mV/dec while the range of linear concentrations of NaCl solutions was between 10-4 and 1 M. The lower detection limit of the sensor reached 8×10-5 M and the response time was less than 1 s. The selectivity coefficient was consistent with the theory of Hofmeister lipophilicity. The lifetime was over 60 days and the repeatability was over 50 times. Moreover, the chloride ion sensor was successfully applied to detecting chloride ions in rinsing solutions for contact lenses, and the experimental results revealed that the correlation coefficient was 0.99.

  4. Oxomemazine hydro­chloride

    OpenAIRE

    Siddegowda, M. S.; Butcher, Ray J.; Mehmet Akkurt; Yathirajan, H.S.; Ramesh, A. R.

    2011-01-01

    In the title compound [systematic name: 3-(5,5-dioxophenothiazin-10-yl)-N,N,2-trimethylpropanaminium chloride], C18H23N2O2S+·Cl−, the dihedral angle between the two outer aromatic rings of the phenothiazine unit is 30.5 (2)°. In the crystal, the components are linked by N—H...Cl and C—H...Cl hydrogen bonds and C—H...π interactions.

  5. 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.

  6. Developing chloride resisting concrete using PFA

    Energy Technology Data Exchange (ETDEWEB)

    Dhir, R.K.; El-Mohr, M.A.K.; Dyer, T.D. [Univ. of Dundee (United Kingdom). Dept. of Civil Engineering

    1997-11-01

    PFA concrete mixes were designed to optimize resistance to chloride ingress. Chloride binding capacity, intrinsic permeability and their concomitant influence on the coefficient of chloride diffusion have been investigated. PFA replacements up to 67% and exposure concentrations of 0.1, 0.5, 1.0 and 5.0 mole/liter were used. Chloride binding capacity was found to increase with increasing PFA replacement up to 50% and to then decline. It increased with chloride exposure concentration as well as water/binder ratio. The coefficient of chloride diffusion of concrete samples was found to be dependent on both the intrinsic permeability of the concrete and the ability of its cement matrix to bind chlorides.

  7. Salt, chloride, bleach, and innate host defense.

    Science.gov (United States)

    Wang, Guoshun; Nauseef, William M

    2015-08-01

    Salt provides 2 life-essential elements: sodium and chlorine. Chloride, the ionic form of chlorine, derived exclusively from dietary absorption and constituting the most abundant anion in the human body, plays critical roles in many vital physiologic functions, from fluid retention and secretion to osmotic maintenance and pH balance. However, an often overlooked role of chloride is its function in innate host defense against infection. Chloride serves as a substrate for the generation of the potent microbicide chlorine bleach by stimulated neutrophils and also contributes to regulation of ionic homeostasis for optimal antimicrobial activity within phagosomes. An inadequate supply of chloride to phagocytes and their phagosomes, such as in CF disease and other chloride channel disorders, severely compromises host defense against infection. We provide an overview of the roles that chloride plays in normal innate immunity, highlighting specific links between defective chloride channel function and failures in host defense.

  8. Subcellular localization of ammonium transporters in Dictyostelium discoideum

    Directory of Open Access Journals (Sweden)

    Davis Carter T

    2008-12-01

    Full Text Available Abstract Background With the exception of vertebrates, most organisms have plasma membrane associated ammonium transporters which primarily serve to import a source of nitrogen for nutritional purposes. Dictyostelium discoideum has three ammonium transporters, Amts A, B and C. Our present work used fluorescent fusion proteins to determine the cellular localization of the Amts and tested the hypothesis that the transporters mediate removal of ammonia generated endogenously from the elevated protein catabolism common to many protists. Results Using RFP and YFP fusion constructs driven by the actin 15 promoter, we found that the three ammonium transporters were localized on the plasma membrane and on the membranes of subcellular organelles. AmtA and AmtB were localized on the membranes of endolysosomes and phagosomes, with AmtB further localized on the membranes of contractile vacuoles. AmtC also was localized on subcellular organelles when it was stabilized by coexpression with either the AmtA or AmtB fusion transporter. The three ammonium transporters exported ammonia linearly with regard to time during the first 18 hours of the developmental program as revealed by reduced export in the null strains. The fluorescently tagged transporters rescued export when expressed in the null strains, and thus they were functional transporters. Conclusion Unlike ammonium transporters in most organisms, which import NH3/NH4+ as a nitrogen source, those of Dictyostelium export ammonia/ammonium as a waste product from extensive catabolism of exogenously derived and endogenous proteins. Localization on proteolytic organelles and on the neutral contractile vacuole suggests that Dictyostelium ammonium transporters may have unique subcellular functions and play a role in the maintenance of intracellular ammonium distribution. A lack of correlation between the null strain phenotypes and ammonia excretion properties of the ammonium transporters suggests that it is not

  9. [Reasons of high concentration ammonium in Yellow River, China].

    Science.gov (United States)

    Zhang, Xue-qing; Xia, Xing-hui; Yang, Zhi-feng

    2007-07-01

    Ammonium nitrogen contamination is one of the major problems of the Yellow River in China. The speciation, concentration and sources of nitrogen compounds as well as the water environment conditions of the Yellow River had been analyzed to study the reasons for the fact that the ammonium nitrogen concentration was above the water quality standard. In addition, laboratory experiments had been carried out to investigate the effects of suspended sediment (SS) on nitrification rate. The results indicated that the presence of SS could accelerate the nitrification process, therefore, the effects of SS on nitrification rate was not the reason for the high level of ammonium nitrogen in the river. The excessive and continuous input of nitrogen contaminants to the river was the fundamental reason for the high concentration of ammonium nitrogen. Organic and ammonium nitrogen with high concentration inhibitted the nitrification processes. When the initial NH4+ -N concentrations were 10.1, 18.4 and 28.2 mg/L, nitrification efficiencies were 17.4%, 13.0% and 2.5%, respectively. When the initial organic nitrogen concentrations were 5.5 and 8.6 mg/L, the maximum concentrations of ammonium nitrogen produced by the oxidation of organic nitrogen would reach 0.47 and 1.69 mg/L and they would last for 2 days and 6 days, respectively. The oxygen-consuming organics and toxic substance existing in the river water could inhibit the activity of nitrifying bacteria, and thus lead to the accumulation of ammonium nitrogen. In addition, the high pH value of river water resulted in the high concentration of nonionic ammonium nitrogen which would reduce the activity of nitrifying bacteria and decrease the nitrification rates. Besides, low river runoff, low SS content and low activity of nitrifying bacteria resulted in the high level of ammonium nitrogen of the river in the low water season.

  10. 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.

  11. Antimicrobial Polymeric Materials with Quaternary Ammonium and Phosphonium Salts

    Directory of Open Access Journals (Sweden)

    Yan Xue

    2015-02-01

    Full Text Available Polymeric materials containing quaternary ammonium and/or phosphonium salts have been extensively studied and applied to a variety of antimicrobial-relevant areas. With various architectures, polymeric quaternary ammonium/phosphonium salts were prepared using different approaches, exhibiting different antimicrobial activities and potential applications. This review focuses on the state of the art of antimicrobial polymers with quaternary ammonium/phosphonium salts. In particular, it discusses the structure and synthesis method, mechanisms of antimicrobial action, and the comparison of antimicrobial performance between these two kinds of polymers.

  12. Conversion of Hydrogen Sulfide in Coal Gases to Liquid Elemental Sulfur with Monolithic Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    K. C. Kwon

    2007-09-30

    Removal of hydrogen sulfide (H{sub 2}S) from coal gasifier gas and sulfur recovery are key steps in the development of Department of Energy's (DOE's) advanced power plants that produce electric power and clean transportation fuels with coal and natural gas. These plants will require highly clean coal gas with H{sub 2}S below 1 ppmv and negligible amounts of trace contaminants such as hydrogen chloride, ammonia, alkali, heavy metals, and particulate. The conventional method of sulfur removal and recovery employing amine, Claus, and tail-gas treatment is very expensive. A second generation approach developed under DOE's sponsorship employs hot-gas desulfurization (HGD) using regenerable metal oxide sorbents followed by Direct Sulfur Recovery Process (DSRP). However, this process sequence does not remove trace contaminants and is targeted primarily towards the development of advanced integrated gasification combined cycle (IGCC) plants that produce electricity (not both electricity and transportation fuels). There is an immediate as well as long-term need for the development of cleanup processes that produce highly clean coal gas for next generation power plants. To this end, a novel process is now under development at several research organizations in which the H{sub 2}S in coal gas is directly oxidized to elemental sulfur over a selective catalyst. Such a process is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S In the Single-Step Sulfur Recovery Process (SSRP), the direct oxidation of H{sub 2}S to elemental sulfur in the presence of SO{sub 2} is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S. This direct oxidation process has the potential to produce a super clean coal gas more economically than both conventional amine-based processes and HGD/DSRP. The H{sub 2} and

  13. Conversion of Hydrogen Sulfide in Coal Gases to Liquid Elemental Sulfur with Monolithic Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    K.C. Kwon

    2009-09-30

    Removal of hydrogen sulfide (H{sub 2}S) from coal gasifier gas and sulfur recovery are key steps in the development of Department of Energy's (DOE's) advanced power plants that produce electric power and clean transportation fuels with coal and natural gas. These plants will require highly clean coal gas with H{sub 2}S below 1 ppmv and negligible amounts of trace contaminants such as hydrogen chloride, ammonia, alkali, heavy metals, and particulate. The conventional method of sulfur removal and recovery employing amine, Claus, and tail-gas treatment is very expensive. A second generation approach developed under DOE's sponsorship employs hot-gas desulfurization (HGD) using regenerable metal oxide sorbents followed by Direct Sulfur Recovery Process (DSRP). However, this process sequence does not remove trace contaminants and is targeted primarily towards the development of advanced integrated gasification combined cycle (IGCC) plants that produce electricity (not both electricity and transportation fuels). There is an immediate as well as long-term need for the development of cleanup processes that produce highly clean coal gas for next generation power plants. To this end, a novel process is now under development at several research organizations in which the H{sub 2}S in coal gas is directly oxidized to elemental sulfur over a selective catalyst. Such a process is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S In the Single-Step Sulfur Recovery Process (SSRP), the direct oxidation of H{sub 2}S to elemental sulfur in the presence of SO{sub 2} is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S. This direct oxidation process has the potential to produce a super clean coal gas more economically than both conventional amine-based processes and HGD/DSRP. The H{sub 2} and

  14. Conversion of Hydrogen Sulfide in Coal Gases to Liquid Elemental Sulfur with Monolithic Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    K. C. Kwon

    2007-09-30

    Removal of hydrogen sulfide (H{sub 2}S) from coal gasifier gas and sulfur recovery are key steps in the development of Department of Energy's (DOE's) advanced power plants that produce electric power and clean transportation fuels with coal and natural gas. These plants will require highly clean coal gas with H{sub 2}S below 1 ppmv and negligible amounts of trace contaminants such as hydrogen chloride, ammonia, alkali, heavy metals, and particulate. The conventional method of sulfur removal and recovery employing amine, Claus, and tail-gas treatment is very expensive. A second generation approach developed under DOE's sponsorship employs hot-gas desulfurization (HGD) using regenerable metal oxide sorbents followed by Direct Sulfur Recovery Process (DSRP). However, this process sequence does not remove trace contaminants and is targeted primarily towards the development of advanced integrated gasification combined cycle (IGCC) plants that produce electricity (not both electricity and transportation fuels). There is an immediate as well as long-term need for the development of cleanup processes that produce highly clean coal gas for next generation power plants. To this end, a novel process is now under development at several research organizations in which the H{sub 2}S in coal gas is directly oxidized to elemental sulfur over a selective catalyst. Such a process is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S In the Single-Step Sulfur Recovery Process (SSRP), the direct oxidation of H{sub 2}S to elemental sulfur in the presence of SO{sub 2} is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S. This direct oxidation process has the potential to produce a super clean coal gas more economically than both conventional amine-based processes and HGD/DSRP. The H{sub 2} and

  15. Monolithic LC method applied to fesoterodine fumarate low dose extended-release tablets: Dissolution and release kinetics

    Directory of Open Access Journals (Sweden)

    Maximiliano S. Sangoi

    2015-04-01

    Full Text Available A dissolution test for fesoterodine low dose extended-release tablets using liquid chromatographic (LC method equipped with a C18 monolithic column was developed and validated. LC system was operated isocratically at controlled temperature (40 °C using a mobile phase of acetonitrile:methanol:0.03 M ammonium acetate (pH 3.8 (30:15:55, v/v/v, run at a flow rate of 1.5 mL/min and detected at 208 nm. The best dissolution conditions for this formulation were achieved using a USP apparatus 2 (paddle at 100 rpm and 900 mL of phosphate buffer at pH 6.8 as the dissolution medium. Validation parameters such as the specificity, linearity, accuracy, precision, and robustness were evaluated according to international guidelines, giving results within the acceptable range. The kinetic parameters of drug release were also investigated using model-dependent methods and the dissolution profiles were best described by the Higuchi model. The validated dissolution test can be applied for quality control of this formulation.

  16. Monolithic LC method applied to fesoterodine fumarate low dose extended-release tablets:Dissolution and release kinetics

    Institute of Scientific and Technical Information of China (English)

    Maximiliano S. Sangoi; Vítor Todeschini; Martin Steppe

    2015-01-01

    A dissolution test for fesoterodine low dose extended-release tablets using liquid chromato-graphic (LC) method equipped with a C18 monolithic column was developed and validated. LC system was operated isocratically at controlled temperature (40 1C) using a mobile phase of acetonitrile:methanol:0.03 M ammonium acetate (pH 3.8) (30:15:55, v/v/v), run at a flow rate of 1.5 mL/min and detected at 208 nm. The best dissolution conditions for this formulation were achieved using a USP apparatus 2 (paddle) at 100 rpm and 900 mL of phosphate buffer at pH 6.8 as the dissolution medium. Validation parameters such as the specificity, linearity, accuracy, precision, and robustness were evaluated according to international guidelines, giving results within the acceptable range. The kinetic parameters of drug release were also investigated using model-dependent methods and the dissolution profiles were best described by the Higuchi model. The validated dissolution test can be applied for quality control of this formulation.

  17. A novel ionic liquid-modified organic-polymer monolith as the sorbent for in-tube solid-phase microextraction of acidic food additives.

    Science.gov (United States)

    Wang, Ting-Ting; Chen, Yi-Hui; Ma, Jun-Feng; Hu, Min-Jie; Li, Ying; Fang, Jiang-Hua; Gao, Hao-Qi

    2014-08-01

    A novel ionic liquid-modified organic-polymer monolithic capillary column was prepared and used for in-tube solid-phase microextraction (SPME) of acidic food additives. The primary amino group of 1-aminopropyl-3-methylimidazolium chloride was reacted with the epoxide group of glycidyl methacrylate. The as-prepared new monomer was then copolymerized in situ with acrylamide and N,N'-methylenebisacrylamide in the presence of polyethylene glycol (PEG)-8000 and PEG-10,000 as porogens. The extraction performance of the developed monolithic sorbent was evaluated for benzoic acid, 3-hydroxybenzoic acid, cinnamic acid, 2,4-dichlorophenoxyacetic acid, and 3-(trifluoromethyl)-cinnamic acid. Such a sorbent, bearing hydrophobic and anion-exchange groups, had high extraction efficiency towards the test compounds. The adsorption capacities for the analytes dissolved in water ranged from 0.18 to 1.74 μg cm(-1). Good linear calibration curves (R(2) > 0.99) were obtained, and the limits of detection (S/N = 3) for the analytes were found to be in the range 1.2-13.5 ng mL(-1). The recoveries of five acidic food additives spiked in Coca-Cola beverage samples ranged from 85.4 % to 98.3 %, with RSD less than 6.9 %. The excellent applicability of the ionic liquid (IL)-modified monolithic column was further tested by the determination of benzoic acid content in Sprite samples, further illustrating its good potential for analyzing food additives in complex samples.

  18. Reprocessing of LEU U-Mo Dispersion and Monolithic Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Vandegrift, G.F.; Jerden, J.; Stepinski, D.C.; Figueroa, J.; Williamson, M.A.; Kleeck, M.A. Van; Blaskovitz, R.J.; Ziegler, A.J.; Maggos, L.E.; Swanson, J.; Fortner, J.; Bakel, A.J. [Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 S. Cass Ave., Argonne, IL 60439 (United States)

    2011-07-01

    For conversion of high-performance research reactors from high-enriched uranium (HEU) to low-enriched uranium (LEU) fuel, a fuel material with a higher density than uranium aluminide is required. Development studies are underway to develop U-Mo dispersion and monolithic fuels for conversion of several high- performance reactors. For dispersion fuels, development is narrowing down to a composition of U-7Mo dispersed in an aluminium matrix containing {approx}5% silicon. For monolithic fuels to be used in high performance research reactors in the United States, a zirconium-bonded U-10Mo foil appears to be the fuel of choice. For conversion to be realized a back-end disposition path is required for both fuels; one disposition pathway is reprocessing. Argonne National Laboratory is developing a pyroprocess for reprocessing spent monolithic fuel. Pyroprocessing was chosen over conventional aqueous solvent extraction due to the necessity of adding fluoride to the fuel-dissolution solution in order to dissolve the zirconium bonding layer on the U-Mo fuel. The proposed flowsheet and development activities will be described. A literature survey points to the ability to reprocess U-Mo dispersion fuels by an aqueous process, but due to several special characteristics of the fuel, the solvent-extraction flowsheets will be a departure from that normally used for the reprocessing of power reactor fuel. Special concerns that must be addressed in reprocessing these fuels are, for example, the low solubilities of uranyl molybdate, molybdic acid, and silicic acid in nitric acid solutions. This paper will address these concerns and development activities required to overcome them. (author)

  19. 10Gbps monolithic silicon FTTH transceiver for PON

    Science.gov (United States)

    Zhang, J.; Liow, T. Y.; Lo, G. Q.; Kwong, D. L.

    2010-05-01

    We propose a new passive optical network (PON) configuration and a novel silicon photonic transceiver architecture for optical network unit (ONU), eliminating the need for an internal laser source in ONU. We adopt dual fiber network configuration. The internal light source in each of the ONUs is eliminated. Instead, an extra seed laser source in the optical line termination (OLT) operates in continuous wave mode to serve the ONUs in the PON as a shared and centralized laser source. λ1 from OLT Tx and λ2 from the seed laser are combined by using a WDM combiner and connected to serve the multiple ONUs through the downstream fibers. The ONUs receive the data in λ1. Meanwhile, the ONUs encode and transmit data in λ2, which are sent back to OLT. The monolithic ONU transceiver contains a wavelength-division-multiplexing (WDM) filter component, a silicon modulator and a Ge photo-detector. The WDM in ONU selectively guides λ1 to the Ge-PD where the data in λ1 are detected and converted to electrical signals, and λ2 to the transmitter where the light is modulated by upstream data. The modulated optical signals in λ2 from ONUs are connected back to OLT through upstream fibers. The monolithic ONU transceiver chip size is only 2mm by 4mm. The crosstalk between the Tx and Rx is measured to be less than -20dB. The transceiver chip is integrated on a SFP+ transceiver board. Both Tx and Rx demonstrated data rate capabilities of up to 10Gbps. By implementing this scheme, the ONU transceiver size can be significantly reduced and the assembly processes will be greatly simplified. The results demonstrate the feasibility of mass manufacturing monolithic silicon ONU transceivers via low cost

  20. Recent advances in the preparation and application of monolithic capillary columns in separation science

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Tingting; Yang, Xi; Xu, Yujing [Department of Analytical Chemistry, China Pharmaceutical University, Nanjing, 210009 (China); Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, Nanjing, 210009 (China); Ji, Yibing, E-mail: jiyibing@msn.com [Department of Analytical Chemistry, China Pharmaceutical University, Nanjing, 210009 (China); Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, Nanjing, 210009 (China)

    2016-08-10

    Novel column technologies involving various materials and efficient reactions have been investigated for the fabrication of monolithic capillary columns in the field of analytical chemistry. In addition to the development of these miniaturized systems, a variety of microscale separation applications have achieved noteworthy results, providing a stepping stone for new types of chromatographic columns with improved efficiency and selectivity. Three novel strategies for the preparation of capillary monoliths, including ionic liquid-based approaches, nanoparticle-based approaches and “click chemistry”, are highlighted in this review. Furthermore, we present the employment of state-of-the-art capillary monolithic stationary phases for enantioseparation, solid-phase microextraction, mixed-mode separation and immobilized enzyme reactors. The review concludes with recommendations for future studies and improvements in this field of research. - Highlights: • Preparation of novel monolithic capillary columns have shown powerful potential in analytical chemistry field. • Various materials including ionic liquids and nanoparticles involved into capillary monolithic micro-devices are concluded. • Click chemistry strategy applied for preparing monolithic capillary columns is reviewed. • Recent strategies utilized in constructing different capillary monoliths for enantiomeric separation are summarized. • Advancement of capillary monoliths for complex samples analysis is comprehensively described.

  1. Preparation of a zeolite-modified polymer monolith for identification of synthetic colorants in lipsticks

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Huiqi; Li, Zheng [College of Chemistry, Jilin University, Changchun 130012 (China); Niu, Qian [Jilin Entry-Exit Inspection and Quarantine Bureau, Changchun 130062 (China); Ma, Jiutong [College of Chemistry, Jilin University, Changchun 130012 (China); Jia, Qiong, E-mail: jiaqiong@jlu.edu.cn [College of Chemistry, Jilin University, Changchun 130012 (China)

    2015-10-30

    Graphical abstract: Poly(methacrylic acid-ethylene dimethacrylate) monolithic column embedded with zeolites was prepared and employed for the polymer monolith microextraction of colorants combined with HPLC. - Highlights: • Zeolite, as a kind of mesoporous material, was firstly combined with PMME. • Zeolite@poly(MAA-EDMA) monolith columns were prepared for the enrichment of colorants. • Zeolite@poly(MAA-EDMA) monolith columns demonstrated relatively high extraction capacity. - Abstract: A novel zeolite-modified poly(methacrylic acid-ethylenedimethacrylate) (zeolite@poly(MAA-EDMA)) monolithic column was prepared with the in situ polymerization method and employed in polymer monolith microextraction for the separation and preconcentration of synthetic colorants combined with high performance liquid chromatography. The polymer was characterized by scanning electronmicroscopy, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, and thermo-gravimetric analysis. Various parameters affecting the extraction efficiency were investigated and optimized. Under the optimum experimental conditions, we obtained acceptable linearities, low limits of detection, and good intra-day/inter-day relative standard deviations. The method was applied to the determination of synthetic colorants in lipsticks with recoveries ranged from 70.7% to 109.7%. Compared with conventional methacrylic acid-based monoliths, the developed monolith exhibited high enrichment capacity because of the introduction of zeolites into the preparation process. The extraction efficiency followed the order: zeolite@poly(MAA-EDMA) > poly(MAA-EDMA) > direct HPLC analysis.

  2. W-band monolithic oscillator using InAlAs/InGaAs HEMT

    Science.gov (United States)

    Kwon, Y.; Pavlidis, D.; Tutt, M.; Ng, G. I.; Lai, R.

    1990-01-01

    A W-band monolithic integrated oscillator circuit was designed and fabricated using submicron HEMT technology. The oscillation frequency was around 81 GHz and the power was -7 dBm at the chip level. This is the first report of an InAlAs/InGaAs monolithic oscillator operating at the W-band.

  3. Hybrid and monolithic integration of planar lightwave circuits (PLCs)

    Science.gov (United States)

    Chen, Ray T.

    2008-02-01

    In this paper, we review the status of monolithic and hybrid integration of planar lightwave circuits (PLCs). Building blocks needed for system integration based on polymeric materials, III-V semiconductor materials, LiNbO 3 and SOI on Silicon are summarized with pros and cons. Due to the maturity of silicon CMOS technology, silicon becomes the platform of choice for optical application specific integrated circuits (OASICs). However, the indirect bandgap of silicon makes the formation of electrically pumped silicon laser a remote plausibility which requires hybrid integration of laser sources made out of III-V compound semicouductor.

  4. Rapid Preparation of Monolithic Columns for Capillary Electrochromatography Separation

    Institute of Scientific and Technical Information of China (English)

    Wen Jun GONG; Yi Jun ZHANG; Yu Ping ZHANG; Seong Ho CHOI

    2006-01-01

    Fritless packed silica gel columns were prepared using sol-gel technology. The part of a75 μm i.d. capillary was filled with a mixture of methacryloxypropyltrimethoxysilane, toluene and hydrochloric acid. Four different photoinitiators such as benzoin methyl ether, Irgacure 819,Irgacure 1700 and irgacure 1800 were added in the presence or absence of sodium dodecyl sulfate during the polymerization process. The above eight solutions were irradiated at 365 nm about5-10 min to prepare the porous monolithic sol-gel columns by a one-step process.

  5. A Monolithic Filter Cavity for Experiments in Quantum Optics

    CERN Document Server

    Palittapongarnpim, Pantita; Lvovsky, A I

    2012-01-01

    By applying a high-reflectivity dielectric coating on both sides of a commercial plano-convex lens, we produce a stable monolithic Fabry-Perot cavity suitable for use as a narrow band filter in quantum optics experiments. The resonant frequency is selected by means of thermal expansion. Owing to the long term mechanical stability, no optical locking techniques are required. We characterize the cavity performance as an optical filter, obtaining a 45 dB suppression of unwanted modes while maintaining a transmission of 60%.

  6. Inherent polarization entanglement generated from a monolithic semiconductor chip

    DEFF Research Database (Denmark)

    Horn, Rolf T.; Kolenderski, Piotr; Kang, Dongpeng

    2013-01-01

    Creating miniature chip scale implementations of optical quantum information protocols is a dream for many in the quantum optics community. This is largely because of the promise of stability and scalability. Here we present a monolithically integratable chip architecture upon which is built...... a photonic device primitive called a Bragg reflection waveguide (BRW). Implemented in gallium arsenide, we show that, via the process of spontaneous parametric down conversion, the BRW is capable of directly producing polarization entangled photons without additional path difference compensation, spectral...... as a serious contender on which to build large scale implementations of optical quantum processing devices....

  7. Remote Sensing with Commutable Monolithic Laser and Detector

    Science.gov (United States)

    2016-01-01

    The ubiquitous trend toward miniaturized sensing systems demands novel concepts for compact and versatile spectroscopic tools. Conventional optical sensing setups include a light source, an analyte interaction region, and a separate external detector. We present a compact sensor providing room-temperature operation of monolithic surface-active lasers and detectors integrated on the same chip. The differentiation between emitter and detector is eliminated, which enables mutual commutation. Proof-of-principle gas measurements with a limit of detection below 400 ppm are demonstrated. This concept enables a crucial miniaturization of sensing devices. PMID:27785455

  8. A novel carbon fiber based porous carbon monolith

    Energy Technology Data Exchange (ETDEWEB)

    Burchell, T.D.; Klett, J.W.; Weaver, C.E.

    1995-06-01

    A novel porous carbon material based on carbon fibers has been developed. The material, when activated, develops a significant micro- or mesopore volume dependent upon the carbon fiber type utilized (isotropic pitch or polyacrylonitrile). The materials will find applications in the field of fluid separations or as a catalyst support. Here, the manufacture and characterization of our porous carbon monoliths are described. A novel adsorbent carbon composite material has been developed comprising carbon fibers and a binder. The material, called carbon fiber composite molecular sieve (CFCMS), was developed through a joint research program between Oak Ridge National Laboratory (ORNL) and the University of Kentucky, Center for Applied Energy Research (UKCAER).

  9. A monolithically integrated torsional CMOS-MEMS relay

    Science.gov (United States)

    Riverola, M.; Sobreviela, G.; Torres, F.; Uranga, A.; Barniol, N.

    2016-11-01

    We report experimental demonstrations of a torsional microelectromechanical (MEM) relay fabricated using the CMOS-MEMS approach (or intra-CMOS) which exploits the full foundry inherent characteristics enabling drastic reduction of the fabrication costs and batch production. In particular, the relay is monolithically integrated in the back end of line of a commercial standard CMOS technology (AMS 0.35 μm) and released by means of a simple one-step mask-less wet etching. The fabricated torsional relay exhibits an extremely steep switching behaviour symmetrical about both contact sides with an on-state contact resistance in the k Ω -range throughout the on-off cycling test.

  10. 14N NQR and relaxation in ammonium nitrate

    Science.gov (United States)

    Stephenson, David

    2015-04-01

    The complete 14N 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 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.

  11. Direct esterification of ammonium salts of carboxylic acids

    Science.gov (United States)

    Halpern, Yuval

    2003-06-24

    A non-catalytic process for producing esters, the process comprising reacting an ammonium salt of a carboxylic acid with an alcohol and removing ammonia from the reaction mixture. Selectivities for the desired ester product can exceed 95 percent.

  12. 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.

  13. {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.

  14. 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

  15. Development of a silica monolith modified with Fe3O4 nano-particles in centrifugal spin column format for the extraction of phosphorylated compounds.

    Science.gov (United States)

    Alwy, Ali; Clarke, Sarah P; Brougham, Dermot F; Twamley, Brendan; Paull, Brett; White, Blánaid; Connolly, Damian

    2015-01-01

    In this study, citrate-stabilised iron oxide nano-particles (∼16 nm) have been immobilised on commercial silica monolithic centrifugal spin columns (MonoSpin) for the extraction of phosphorylated compounds. Two alternative strategies were adopted involving either direct electrostatic attachment to an aminated MonoSpin (single-layer method) in the first instance, or the use of a layer-by-layer method with poly(diallyldimethylammonium) chloride. Field-emission scanning electron spectroscopy and energy-dispersive X-ray spectroscopy was used for confirming notably higher coverage of nano-particles using the layer-by-layer method (2.49 ± 0.53 wt%) compared with the single-layer method (0.43 ± 0.30 wt%). The modified monolith was used for the selective separation/extraction of adenosine monophosphate, adenosine diphosphate and adenosine triphosphate with elution using a phosphate buffer. A reversed-phase liquid chromatographic assay was used for confirming that adenosine, as a non-phosphorylated control was not retained on the modified MonoSpin devices, whereas recovery of 80% for adenosine monophosphate, 86% for adenosine diphosphate and 82% for adenosine triphosphate was achieved.

  16. Methacrylate-bonded covalent-organic framework monolithic columns for high performance liquid chromatography.

    Science.gov (United States)

    Liu, Li-Hua; Yang, Cheng-Xiong; Yan, Xiu-Ping

    2017-01-06

    Covalent-organic frameworks (COFs) are a newfangled class of intriguing microporous materials. Considering their unique properties, COFs should be promising as packing materials for high performance liquid chromatography (HPLC). However, the irregular shape and sub-micrometer size of COFs synthesized via the traditional methods render the main obstacles for the application of COFs in HPLC. Herein, we report the preparation of methacrylate-bonded COF monolithic columns for HPLC to overcome the above obstacles. The prepared COF bonded monolithic columns not only show good homogeneity and permeability, but also give high column efficiency, good resolution and precision for HPLC separation of small molecules including polycyclic aromatic hydrocarbons, phenols, anilines, nonsteroidal anti-inflammatory drugs and benzothiophenes. Compared with the bare polymer monolithic column, the COF bonded monolithic columns show enhanced hydrophobic, π-π and hydrogen bond interactions in reverse phase HPLC. The results reveal the great potential of COF bonded monoliths for HPLC and COFs in separation sciences.

  17. Preparation of a biomimetic polyphosphorylcholine monolithic column for immobilized artificial membrane chromatography.

    Science.gov (United States)

    Zhao, XiangLong; Chen, WeiJia; Zhou, ZhengYin; Wang, QiQin; Liu, ZhengHua; Moaddel, Ruin; Jiang, ZhengJin

    2015-08-14

    The present work aims to prepare a novel phosphatidylcholine functionalized monolithic stationary phase by in situ co-polymerization of 12-methacryloyl dodecylphosphocholine (MDPC) and ethylene dimethacrylate (EDMA) for immobilized artificial membrane chromatography. Scanning electron microscopy, energy dispersive X-ray spectroscopy, FT-IR spectroscopy, pore size distribution analysis, ζ-potential analysis and micro-HPLC were used to evaluate the monolithic structure and physicochemical properties. Satisfactory morphology, high mechanical stability, good permeability and chromatographic performance were obtained on the optimized monolithic columns. A typical reverse-phase retention mechanism was observed over a wide range of organic solvent content (acetonitrilecolumn (IAM.PC.DD2) and poly(MDPC-co-EDMA) monolith. This novel poly(MDPC-co-EDMA) monolith exhibited good potential for studying the drug-membrane interaction.

  18. Monitoring catalysts at work in their final form: spectroscopic investigations on a monolithic catalyst

    DEFF Research Database (Denmark)

    Rasmussen, Søren B.; Bañares, Miguel A.; Bazin, Philippe;

    2012-01-01

    A monolithic vanadia–titania based catalyst has been subjected to studies with in situ FTIR spectroscopy coupled with mass spectrometry, during the SCR (Selective Catalytic Reduction) reaction. A device based on a transmission reactor cell for monolithic samples was constructed, dedicated to the ...... with other surface or bulk sensitive techniques, e.g. Raman and UV-vis spectroscopy.......A monolithic vanadia–titania based catalyst has been subjected to studies with in situ FTIR spectroscopy coupled with mass spectrometry, during the SCR (Selective Catalytic Reduction) reaction. A device based on a transmission reactor cell for monolithic samples was constructed, dedicated....... The observations reported here serve as a demonstration of the great potential for the application of operando spectroscopy on monolithic systems. This cross disciplinary approach aims to identify reaction pathways, active sites, intermediate- and spectator-species for catalytic reactions under truly industrial...

  19. Synthesis and methane storage of binder-free porous graphene monoliths

    Institute of Scientific and Technical Information of China (English)

    Guoqing Ning; Hao Wang; Xiaoxin Zhang; Chenggen Xu; Guangjin Chen; Jinsen Gao

    2013-01-01

    Nanomesh graphene (NMG) obtained by template chemical vapor deposition was used to synthesize the binder-free graphene monoliths by simple tablet pressing.The stacking manner of the NMG sheets was crucial to the cohesion interaction between the graphene sheets,only the NMG materials with a loosely stacking manner could be pressed into binder-free monoliths.At the tableting pressure of 2-8 MPa,both the bulk densities and the specific surface areas of the monoliths keep nearly constant as the tableting pressure increases,indicating that the NMG monoliths have obvious elasticity and a porous structure due to the large corrugations and the mesh structures of the graphene sheets.As a result,an extraordinary methane storage capacity of 236 (v/v) at 9MPa was obtained in the graphene monolith prepared by tableting at 4 MPa.

  20. Ammonium Metabolism Enzymes Aid Helicobacter pylori Acid Resistance

    OpenAIRE

    2014-01-01

    The gastric pathogen Helicobacter pylori possesses a highly active urease to support acid tolerance. Urea hydrolysis occurs inside the cytoplasm, resulting in the production of NH3 that is immediately protonated to form NH4+. This ammonium must be metabolized or effluxed because its presence within the cell is counterproductive to the goal of raising pH while maintaining a viable proton motive force (PMF). Two compatible hypotheses for mitigating intracellular ammonium toxicity include (i) th...

  1. 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.

  2. Oxomemazine hydro­chloride

    Science.gov (United States)

    Siddegowda, M. S.; Butcher, Ray J.; Akkurt, Mehmet; Yathirajan, H. S.; Ramesh, A. R.

    2011-01-01

    In the title compound [systematic name: 3-(5,5-dioxo­phen­othia­zin-10-yl)-N,N,2-trimethyl­propanaminium chloride], C18H23N2O2S+·Cl−, the dihedral angle between the two outer aromatic rings of the phenothia­zine unit is 30.5 (2)°. In the crystal, the components are linked by N—H⋯Cl and C—H⋯Cl hydrogen bonds and C—H⋯π inter­actions. PMID:22090928

  3. 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....

  4. Chloride Ion Critical Content in Reinforced Concrete

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Chloride ion critical content was studied under soaking and cycle of dry and wet conditions,with three electrochemical nondestructive measuring techniques, i e, half-cell potential, A C impedance, and time potential. The experimental results show that chloride ion critical content is primarily determined by the water cement ratio, while for the same concrete mixture the chloride ion critical content in soaking conditions is larger than that in a cycle of dry and wet conditions.

  5. Monolithic molecularly imprinted polymeric capillary columns for isolation of aflatoxins.

    Science.gov (United States)

    Szumski, Michał; Grzywiński, Damian; Prus, Wojciech; Buszewski, Bogusław

    2014-10-17

    Monolithic molecularly imprinted polymers extraction columns have been prepared in fused-silica capillaries by UV or thermal polymerization in a two-step process. First, a poly-(trimethylolpropane trimethacrylate) (polyTRIM) core monolith was synthesized either by UV or thermal polymerization. Then it was grafted with the mixture of methacrylic acid (MAA) as a functional monomer, ethylene dimethacrylate (EDMA) as a cross-linking agent, 5,7-dimethoxycoumarin (DMC) as an aflatoxin-mimicking template, toluene as a porogen solvent and 2,2-azobis-(2-methylpropionitrile) (AIBN) as an initiator of the polymerization reaction. Different thermal condition of the photografting and different concentrations of the grafting mixture were tested during polymerization. The extraction capillary columns were evaluated in the terms of their hydrodynamic and chromatographic properties. Retention coefficients for aflatoxin B1 and DMC were used for assessment of the selectivity and imprinting factor. The obtained results indicate that the temperature of photografting and concentration of the grafting mixture are key parameters that determine the quality of the prepared MIPs. From the MIP columns characterized by the highest permeability the column of the highest imprinting factor was applied for isolation of aflatoxins B1, B2, G1 and G2 from the model aqueous sample followed by on-line chromatographic separation. The process was performed using a micro-MISPE-microLC-LIF system of a novel design, which allowed for detection of the eluates from the sample preparation part as well as from the chromatographic separation.

  6. Monolithic integrated optic fiber Bragg grating sensor interrogator

    Science.gov (United States)

    Mendoza, Edgar A.; Esterkin, Yan; Kempen, Cornelia; Sun, Songjian

    2010-04-01

    Fiber Bragg gratings (FBGs) are a mature sensing technology that has gained rapid acceptance in civil, aerospace, chemical and petrochemical, medicine, aviation and automotive industries. Fiber Bragg grating sensors can be use for a variety of measurements including strain, stress, vibration, acoustics, acceleration, pressure, temperature, moisture, and corrosion distributed at multiple locations within the structure using a single fiber element. The most prominent advantages of FBGs are: small size and light weight, multiple FBG transducers on a single fiber, and immunity to radio frequency interference. A major disadvantage of FBG technology is that conventional state-of-the-art fiber Bragg grating interrogation systems are typically bulky, heavy, and costly bench top instruments that are assembled from off-the-shelf fiber optic and optical components integrated with a signal electronics board into an instrument console. Based on the need for a compact FBG interrogation system, this paper describes recent progress towards the development of a miniature fiber Bragg grating sensor interrogator (FBG-TransceiverTM) system based on multi-channel monolithic integrated optic sensor microchip technology. The integrated optic microchip technology enables the monolithic integration of all of the functionalities, both passive and active, of conventional bench top FBG sensor interrogators systems, packaged in a miniaturized, low power operation, 2-cm x 5-cm small form factor (SFF) package suitable for the long-term structural health monitoring in applications where size, weight, and power are critical for operation.

  7. Monolithically integrated Helmholtz coils by 3-dimensional printing

    Energy Technology Data Exchange (ETDEWEB)

    Li, Longguang [Department of Electrical Engineering, University of Michigan–Shanghai Jiao Tong University Joint Institute, Shanghai Jiao Tong University, Shanghai 200240 (China); Abedini-Nassab, Roozbeh; Yellen, Benjamin B., E-mail: yellen@duke.edu [Department of Electrical Engineering, University of Michigan–Shanghai Jiao Tong University Joint Institute, Shanghai Jiao Tong University, Shanghai 200240 (China); Department of Mechanical Engineering and Materials Science, Duke University, P.O. Box 90300, Hudson Hall, Durham, North Carolina 27708 (United States)

    2014-06-23

    3D printing technology is of great interest for the monolithic fabrication of integrated systems; however, it is a challenge to introduce metallic components into 3D printed molds to enable broader device functionality. Here, we develop a technique for constructing a multi-axial Helmholtz coil by injecting a eutectic liquid metal Gallium Indium alloy (EGaIn) into helically shaped orthogonal cavities constructed in a 3D printed block. The tri-axial solenoids each carry up to 3.6 A of electrical current and produce magnetic field up to 70 G. Within the central section of the coil, the field variation is less than 1% and is in agreement with theory. The flow rates and critical pressures required to fill the 3D cavities with liquid metal also agree with theoretical predictions and provide scaling trends for filling the 3D printed parts. These monolithically integrated solenoids may find future applications in electronic cell culture platforms, atomic traps, and miniaturized chemical analysis systems based on nuclear magnetic resonance.

  8. Monolithic Active Pixel Matrix with Binary Counters (MAMBO) ASIC

    Energy Technology Data Exchange (ETDEWEB)

    Khalid, Farah F.; Deptuch, Grzegorz; Shenai, Alpana; Yarema, Raymond J.; /Fermilab

    2010-11-01

    Monolithic Active Matrix with Binary Counters (MAMBO) is a counting ASIC designed for detecting and measuring low energy X-rays from 6-12 keV. Each pixel contains analogue functionality implemented with a charge preamplifier, CR-RC{sup 2} shaper and a baseline restorer. It also contains a window comparator which can be trimmed by 4 bit DACs to remove systematic offsets. The hits are registered by a 12 bit ripple counter which is reconfigured as a shift register to serially output the data from the entire ASIC. Each pixel can be tested individually. Two diverse approaches have been used to prevent coupling between the detector and electronics in MAMBO III and MAMBO IV. MAMBO III is a 3D ASIC, the bottom ASIC consists of diodes which are connected to the top ASIC using {mu}-bump bonds. The detector is decoupled from the electronics by physically separating them on two tiers and using several metal layers as a shield. MAMBO IV is a monolithic structure which uses a nested well approach to isolate the detector from the electronics. The ASICs are being fabricated using the SOI 0.2 {micro}m OKI process, MAMBO III is 3D bonded at T-Micro and MAMBO IV nested well structure was developed in collaboration between OKI and Fermilab.

  9. Macroporous monoliths for trace metal extraction from seawater

    Energy Technology Data Exchange (ETDEWEB)

    Yue, Yanfeng; Mayes, Richard; Gill, Gary A.; Kuo, Li-Jung; Wood, Jordana R.; Binder, Andrew; Brown, Suree; Dai, Sheng

    2015-05-29

    The viability of seawater-based uranium recovery depends on the uranium adsorption rate and capacity, since the concentration of uranium in the oceans is relatively low (3.3 μgL⁻¹). An important consideration for a fast adsorption is to maximize the adsorption properties of adsorbents such as surface areas and pore structures, which can greatly improve the kinetics of uranium extraction and the adsorption capacity simultaneously. Following this consideration, macroporous monolith adsorbents were prepared from the copolymerization of acrylonitrile (AN) and N,N’-methylenebis(acrylamide) (MBAAm) based on a cryogel method using both hydrophobic and hydrophilic monomers. The monolithic sorbents were tested with simulated seawater containing a high uranyl concentration (–6 ppm) and the uranium adsorption results showed that the adsorption capacities are strongly influenced by the ratio of monomer to the crosslinker, i.e., the density of the amidoxime groups. The preliminary seawater testing indicates the high salinity content of seawater does not hinder the adsorption of uranium.

  10. Monolithically Integrated Ge-on-Si Active Photonics

    Directory of Open Access Journals (Sweden)

    Jifeng Liu

    2014-07-01

    Full Text Available Monolithically integrated, active photonic devices on Si are key components in Si-based large-scale electronic-photonic integration for future generations of high-performance, low-power computation and communication systems. Ge has become an interesting candidate for active photonic devices in Si photonics due to its pseudo-direct gap behavior and compatibility with Si complementary metal oxide semiconductor (CMOS processing. In this paper, we present a review of the recent progress in Ge-on-Si active photonics materials and devices for photon detection, modulation, and generation. We first discuss the band engineering of Ge using tensile strain, n-type doping, Sn alloying, and separate confinement of Γ vs. L electrons in quantum well (QW structures to transform the material towards a direct band gap semiconductor for enhancing optoelectronic properties. We then give a brief overview of epitaxial Ge-on-Si materials growth, followed by a summary of recent investigations towards low-temperature, direct growth of high crystallinity Ge and GeSn alloys on dielectric layers for 3D photonic integration. Finally, we review the most recent studies on waveguide-integrated Ge-on-Si photodetectors (PDs, electroabsorption modulators (EAMs, and laser diodes (LDs, and suggest possible future research directions for large-scale monolithic electronic-photonic integrated circuits on a Si platform.

  11. Squeezed light from a diamond-turned monolithic cavity

    CERN Document Server

    Brieussel, A; Campbell, G; Guccione, G; Janousek, J; Hage, B; Buchler, B C; Treps, N; Fabre, C; Fang, F Z; Li, X Y; Symul, T; Lam, P K

    2016-01-01

    For some crystalline materials, a regime can be found where continuous ductile cutting is feasible. Using precision diamond turning, such materials can be cut into complex optical components with high surface quality and form accuracy. In this work we use diamond-turning to machine a monolithic, square-shaped, doubly-resonant $LiNbO_3$ cavity with two flat and two convex facets. When additional mild polishing is implemented, the Q-factor of the resonator is found to be limited only by the material absorption loss. We show how our monolithic square resonator may be operated as an optical parametric oscillator that is evanescently coupled to free-space beams via birefringent prisms. The prism arrangement allows for independent and large tuning of the fundamental and second harmonic coupling rates. We measure $2.6\\pm0.5$ dB of vacuum squeezing at 1064 nm using our system. Potential improvements to obtain higher degrees of squeezing are discussed.

  12. New 3-D microarray platform based on macroporous polymer monoliths.

    Science.gov (United States)

    Rober, M; Walter, J; Vlakh, E; Stahl, F; Kasper, C; Tennikova, T

    2009-06-30

    Polymer macroporous monoliths are widely used as efficient sorbents in different, mostly dynamic, interphase processes. In this paper, monolithic materials strongly bound to the inert glass surface are suggested as operative matrices at the development of three-dimensional (3-D) microarrays. For this purpose, several rigid macroporous copolymers differed by reactivity and hydrophobic-hydrophilic properties were synthesized and tested: (1) glycidyl methacrylate-co-ethylene dimethacrylate (poly(GMA-co-EDMA)), (2) glycidyl methacrylate-co-glycerol dimethacrylate (poly(GMA-co-GDMA)), (3) N-hydroxyphthalimide ester of acrylic acid-co-glycidyl methacrylate-co-ethylene dimethacrylate (poly(HPIEAA-co-GMA-co-EDMA)), (4) 2-cyanoethyl methacrylate-co-ethylene dimethacrylate (poly(CEMA-co-EDMA)), and (5) 2-cyanoethyl methacrylate-co-2-hydroxyethyl methacrylate-co-ethylene dimethacrylate (poly(CEMA-co-HEMA-co-EDMA)). The constructed devices were used as platforms for protein microarrays construction and model mouse IgG-goat anti-mouse IgG affinity pair was used to demonstrate the potential of developed test-systems, as well as to optimize microanalytical conditions. The offered microarray platforms were applied to detect the bone tissue marker osteopontin directly in cell culture medium.

  13. Methacrylate-based monolithic layers for planar chromatography of polymers.

    Science.gov (United States)

    Maksimova, E F; Vlakh, E G; Tennikova, T B

    2011-04-29

    A series of macroporous monolithic methacrylate-based materials was synthesized by in situ free radical UV-initiated copolymerization of functional monomers, such as glycidyl methacrylate (GMA), butyl methacrylate (BuMA), 2-aminoethyl methacrylate (AEMA), 2-hydroxyethyl methacrylate (HEMA) and 2-cyanoethyl methacrylate (CEMA), with crosslinking agent, namely, ethylene glycol dimethacrylate (EDMA). The materials obtained were applied as the stationary phases in simple and robust technique - planar chromatography (PLC). The method of separation layer fabrication representing macroporous polymer monolith bound to the specially prepared glass surface was developed and optimized. The GMA-EDMA and BuMA-EDMA matrixes were successfully applied for the separation of low molecular weight compounds (the mixture of several dies), as well as poly(vinylpyrrolidone) and polystyrene homopolymers of different molecular weights using reversed-phase mechanism. The materials based on copolymers AEMA-HEMA-EDMA and CEMA-HEMA-EDMA were used for normal-phase PLC separation of 2,4-dinitrophenyl amino acids and polystyrene standards.

  14. Fabrication of Monolithic RERTR Fuels by Hot Isostatic Pressing

    Energy Technology Data Exchange (ETDEWEB)

    Jan-Fong Jue; Blair H. Park; Curtis R. Clark; Glenn A. Moore; Dennis D. Keiser, Jr.

    2010-11-01

    The RERTR (Reduced Enrichment for Research and Test Reactors) Program is developing advanced nuclear fuels for high-power test reactors. Monolithic fuel design provides higher uranium loading than that of the traditional dispersion fuel design. Hot isostatic pressing is a promising process for low-cost batch fabrication of monolithic RERTR fuel plates for these high-power reactors. Bonding U Mo fuel foil and 6061 Al cladding by hot isostatic press bonding was successfully developed at Idaho National Laboratory. Due to the relatively high processing temperature, the interaction between fuel meat and aluminum cladding is a concern. Two different methods were employed to mitigate this effect: (1) a diffusion barrier and (2) a doping addition to the interface. Both types of fuel plates have been fabricated by hot isostatic press bonding. Preliminary results show that the direct fuel/cladding interaction during the bonding process was eliminated by introducing a thin zirconium diffusion barrier layer between the fuel and the cladding. Fuel plates were also produced and characterized with a silicon-rich interlayer between fuel and cladding. This paper reports the recent progress of this developmental effort and identifies the areas that need further attention.

  15. Monolithic crystals for PET devices: Optical coupling optimization

    Energy Technology Data Exchange (ETDEWEB)

    González, A.J., E-mail: agonzalez@i3m.upv.es; Peiró, A.; Conde, P.; Hernández, L.; Moliner, L.; Orero, A.; Rodríguez-Álvarez, M.J.; Sánchez, F.; Soriano, A.; Vidal, L.F.; Benlloch, J.M.

    2013-12-11

    In this work we present a method to efficiently collect scintillation light when using monolithic scintillator crystals. The acceptance angle of the scintillation light has been reduced by means of optical devices reducing the border effect which typically affects continuous crystals. We have applied this procedure on gamma detectors for PET systems using both position sensitive PMTs and arrays of SiPMs. In the case of using SiPMs, this approach also helps to reduce the photosensor active area. We evaluated the method using PMTs with a variety of different crystals with thicknesses ranging from 10 to 24 mm. We found that our design allows the use of crystal blocks with a thickness of up to 18 mm without degrading the spatial resolution caused by edge effects and without a significant detriment to the energy resolution. These results were compared with simulated data. The first results of monolithic LYSO crystals coupled to an array of 256 SiPMs by means of individual optical light guides are also presented. -- Highlights: •Acceptance angle reduction decreases border effect in continuous crystals. •Experimental measurements with PMTs correlate well with simulated data. •Optical devices called faceplates serve to control the scintillation light angle. •Simulation on the light propagation for SiPMs requires exhaustive modeling.

  16. 40 CFR 418.40 - Applicability; description of the ammonium nitrate subcategory.

    Science.gov (United States)

    2010-07-01

    ... ammonium nitrate subcategory. 418.40 Section 418.40 Protection of Environment ENVIRONMENTAL PROTECTION... Ammonium Nitrate Subcategory § 418.40 Applicability; description of the ammonium nitrate subcategory. The provisions of this subpart are applicable to discharges resulting from the manufacture of ammonium...

  17. 76 FR 39847 - Solid Fertilizer Grade Ammonium Nitrate From the Russian Federation; Final Results of the...

    Science.gov (United States)

    2011-07-07

    ... International Trade Administration Solid Fertilizer Grade Ammonium Nitrate From the Russian Federation; Final... investigation on solid fertilizer grade ammonium nitrate (``ammonium nitrate'') from the Russian Federation...: Solid Fertilizer Grade Ammonium Nitrate From the Russian Federation, 64 FR 45236 (August 19, 1999)....

  18. 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...... have a serine. The LeuT-E290S mutant displays chloride-dependent activity. We show that, in LeuT-E290S cocrystallized with bromide or chloride, the anion is coordinated by side chain hydroxyls from Tyr47, Ser290, and Thr254 and the side chain amide of Gln250. The bound anion and the nearby sodium ion...

  19. Chloride ingress in cement paste and mortar

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, O.M.; Hansen, P.F.; Coats, A.M.; Glasser, F.P.

    1999-09-01

    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 are 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 diffusion rates.

  20. 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.

  1. 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.

  2. MICRO-DETERMINATION OF DODECYL DIMETHYL BENZYL-AMMONIUM CHLOR IDE%微量十二烷基二甲基苯甲基氯化铵的测定

    Institute of Scientific and Technical Information of China (English)

    俞斌; 王峰; 栾承莲

    2001-01-01

    十二烷基二甲基苯甲基氯化铵、十二烷基磺酸钠和溴百里酚蓝在pH 7.4~8.2范围内形成黄绿色离子缔合物。把十二烷基磺酸钠、溴百里酚蓝、缓冲溶液按顺序加入十二烷基二甲基苯甲基氯化铵中,15 min后于456 nm处测其吸光度,微量测定十二烷基二甲基苯甲基氯化铵的含量。通过调节pH值、加入掩蔽剂掩蔽金属离子排除干扰。%Dodecyl dimethyl benzyl-ammonium chloride, sodium laurylsulfonate and bromothymol blue can form yellowish blue ion association complex in pH 7.4~8.2, affi x sodium laurylsulfonate, bromothymol blue and buffer solution to dodecyl dimeth yl benzyl-ammonium chloride in normal sequence. Record the absorbance data of so lutio n in 456nm with spectrophotometer, micro-determine the content of dodecyl di methyl benzyl-ammonium chloride. The disturbance was removed by adjusting the pH value and adding the screening agent to mask the metalion.

  3. 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.

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

    Science.gov (United States)

    Zawadowicz, M. A.; Proud, S. R.; Seppalainen, S. S.; Cziczo, D. J.

    2015-03-01

    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.

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

    Science.gov (United States)

    Zawadowicz, M. A.; Proud, S. R.; Seppalainen, S. S.; Cziczo, D. J.

    2015-08-01

    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. 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. 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 (Fourier transform infrared) 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. Some results of this study tend to be in agreement with previous microscopy experiments, but others, such as phase separation properties of 1,2,6-hexanetriol, do not agree with previous work. Because the particles studied in this experiment are of a smaller size than those used in microscopy studies, the discrepancies found could be a size-related effect.

  6. 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.

  7. Comparing polyaluminum chloride and ferric chloride for antimony removal.

    Science.gov (United States)

    Kang, Meea; Kamei, Tasuku; Magara, Yasumoto

    2003-10-01

    Antimony has been one of the contaminants required to be regulated, however, only limited information has been collected to date regarding antimony removal by polyaluminium chloride (PACl) and ferric chloride (FC). Accordingly, the possible use of coagulation by PACl or FC for antimony removal was investigated. Jar tests were used to determine the effects of solution pH, coagulant dosage, and pre-chlorination on the removal of various antimony species. Although high-efficiency antimony removal by aluminum coagulation has been expected because antimony is similar to arsenic in that both antimony and arsenic are a kind of metalloid in group V of the periodic chart, this study indicated: (1) removal density (arsenic or antimony removed per mg coagulant) for antimony by PACl was about one forty-fifth as low as observed for As(V); (2) although the removal of both Sb(III) and Sb(V) by coagulation with FC was much higher than that of PACl, a high coagulant dose of 10.5mg of FeL(-1) at optimal pH of 5.0 was still not sufficient to meet the standard antimony level of 2 microg as SbL(-1) for drinking water when around 6 microg as SbL(-1) were initially present. Consequently, investigation of a more appropriate treatment process is necessary to develop economical Sb reduction; (3) although previous studies concluded that As(V) is more effectively removed than As(III), this study showed that the removal of Sb(III) by coagulation with FC was much more pronounced than that of Sb(V); (4) oxidation of Sb(III) with chlorine decreased the ability of FC to remove antimony. Accordingly, natural water containing Sb(III) under anoxic condition should be coagulated without pre-oxidation.

  8. Electrochemical Behavior of Copper in Thionyl Chloride Solutions.

    Science.gov (United States)

    1980-12-01

    lithium - thionyl chloride batteries . Thionyl chloride is known *3 to react...electrolyte for lithium - thionyl chloride batteries . 8R. K. McAlpine and B. A. Soule, Prescott and Johnson’s Qualitative Chemical Analysis, D. Van...black carbon electrodes, cupric chloride appears to be a useful cathode additive for lithium - thionyl chloride batteries . Preliminary results2l

  9. Conversion of Hydrogen Sulfide in Coal Gases to Liquid Elemental Sulfur with Monolithic Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    K.C. Kwon

    2009-09-30

    Removal of hydrogen sulfide (H{sub 2}S) from coal gasifier gas and sulfur recovery are key steps in the development of Department of Energy's (DOE's) advanced power plants that produce electric power and clean transportation fuels with coal and natural gas. These plants will require highly clean coal gas with H{sub 2}S below 1 ppmv and negligible amounts of trace contaminants such as hydrogen chloride, ammonia, alkali, heavy metals, and particulate. The conventional method of sulfur removal and recovery employing amine, Claus, and tail-gas treatment is very expensive. A second generation approach developed under DOE's sponsorship employs hot-gas desulfurization (HGD) using regenerable metal oxide sorbents followed by Direct Sulfur Recovery Process (DSRP). However, this process sequence does not remove trace contaminants and is targeted primarily towards the development of advanced integrated gasification combined cycle (IGCC) plants that produce electricity (not both electricity and transportation fuels). There is an immediate as well as long-term need for the development of cleanup processes that produce highly clean coal gas for next generation power plants. To this end, a novel process is now under development at several research organizations in which the H{sub 2}S in coal gas is directly oxidized to elemental sulfur over a selective catalyst. Such a process is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S In the Single-Step Sulfur Recovery Process (SSRP), the direct oxidation of H{sub 2}S to elemental sulfur in the presence of SO{sub 2} is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S. This direct oxidation process has the potential to produce a super clean coal gas more economically than both conventional amine-based processes and HGD/DSRP. The H{sub 2} and

  10. Monolithic column incorporated with lanthanide metal-organic framework for capillary electrochromatography.

    Science.gov (United States)

    Zhang, Li-Shun; Du, Pei-Yao; Gu, Wen; Zhao, Qing-Li; Huang, Yan-Ping; Liu, Zhao-Sheng

    2016-08-26

    A new lanthanide metal-organic frameworks NKU-1 have successfully incorporated into poly (BMA-co-EDMA) monolith and evaluated by capillary electrochromatography (CEC). Lanthanide metal-organic frameworks [Eu2(ABTC)1.5(H2O)3(DMA)] (NKU-1) were synthesized by self-assembly of Eu(III) ions and 3,3',5,5'-azo benzene tetracarboxylic acid ligands have been fabricated into poly(BMA-co-EDMA) monoliths. 1-Butyl-3-methylimidazolium tetrafluoroborate and N,N-dimethylformamide were developed as binary porogen obtaining homogeneous dispersibility for NKU-1 and high permeability for monolithic column. The successful incorporation of NKU-1 into poly(BMA-co-EDMA) was confirmed and characterized by FT-IR spectra, scanning electron microscopy, X-ray diffraction, energy dispersive spectrometer area scanning, and transmission electron microscopy. Separation ability of the NKU-1-poly (BMA-co-EDMA) monoliths was demonstrated by separating four groups of analytes in CEC, including alkylbenzenes, polycyclic aromatic hydrocarbon, aniline series and naphthyl substitutes. Compared with bare monolithic (column efficiency of 100,000plates/m), the NKU-1-poly (BMA-co-EDMA) monoliths have displayed greater column efficiency (maximum 210,000plates/m) and higher permeability, as well as less peak tailing. The results showed that the NKU-1-poly (BMA-co-EDMA) monoliths are promising stationary phases for CEC separations.

  11. Synthesis and characterization of hierarchically porous metal, metal oxide, and carbon monoliths with highly ordered nanostructure

    Science.gov (United States)

    Grano, Amy Janine

    Hierarchically porous materials are of great interest in such applications as catalysis, separations, fuel cells, and advanced batteries. One such way of producing these materials is through the process of nanocasting, in which a sacrificial template is replicated and then removed to form a monolithic replica. This replica consists of mesopores, which can be ordered or disordered, and bicontinuous macropores, which allow flow throughout the length of the monolith. Hierarchically porous metal oxide and carbon monoliths with an ordered mesopores system are synthesized for the first time via nanocasting. These replicas were used as supports for the deposition of silver particles and the catalytic efficiency was evaluated. The ordered silica template used in producing these monoliths was also used for an in-situ TEM study involving metal nanocasting, and an observation of the destruction of the silica template during nanocasting made. Two new methods of removing the silica template were developed and applied to the synthesis of copper, nickel oxide, and zinc oxide monoliths. Finally, hollow fiber membrane monoliths were examined via x-ray tomography in an attempt to establish the presence of this structure throughout the monolith.

  12. Nitrogen doping in atomic layer deposition grown titanium dioxide films by using ammonium hydroxide

    Energy Technology Data Exchange (ETDEWEB)

    Kaeaeriaeinen, M.-L., E-mail: marja-leena.kaariainen@lut.fi; Cameron, D.C.

    2012-12-30

    Titanium dioxide films have been created by atomic layer deposition using titanium chloride as the metal source and a solution of ammonium hydroxide in water as oxidant. Ammonium hydroxide has been used as a source of nitrogen for doping and three thickness series have been deposited at 350 Degree-Sign C. A 15 nm anatase dominated film was found to possess the highest photocatalytic activity in all film series. Furthermore almost three times better photocatalytic activity was discovered in the doped series compared to undoped films. The doped films also had lower resistivity. The results from X-ray photoemission spectroscopy showed evidence for interstitial nitrogen in the titanium dioxide structure. Besides, there was a minor red shift observable in the thickest samples. In addition the film conductivity was discovered to increase with the feeding pressure of ammonium hydroxide in the oxidant precursor. This may indicate that nitrogen doping has caused the decrease in the resistivity and therefore has an impact as an enhanced photocatalytic activity. The hot probe test showed that all the anatase or anatase dominant films were p-type and all the rutile dominant films were n-type. The best photocatalytic activity was shown by anatase-dominant films containing a small amount of rutile. It may be that p-n-junctions are formed between p-type anatase and n-type rutile which cause carrier separation and slow down the recombination rate. The combination of nitrogen doping and p-n junction formation results in superior photocatalytic performance. - Highlights: Black-Right-Pointing-Pointer We found all N-doped and undoped anatase dominating films p-type. Black-Right-Pointing-Pointer We found all N-doped and undoped rutile dominating films n-type. Black-Right-Pointing-Pointer We propose that p-n junctions are formed in anatase-rutile mixture films. Black-Right-Pointing-Pointer We found that low level N-doping has increased TiO{sub 2} conductivity. Black

  13. Wideband monolithically integrated front-end subsystems and components

    Science.gov (United States)

    Mruk, Joseph Rene

    This thesis presents the analysis, design, and measurements of passive, monolithically integrated, wideband recta-coax and printed circuit board front-end components. Monolithic fabrication of antennas, impedance transformers, filters, and transitions lowers manufacturing costs by reducing assembly time and enhances performance by removing connectors and cabling between the devices. Computational design, fabrication, and measurements are used to demonstrate the capabilities of these front-end assemblies. Two-arm wideband planar log-periodic antennas fed using a horizontal feed that allows for filters and impedance transformers to be readily fabricated within the radiating region of the antenna are demonstrated. At microwave frequencies, low-cost printed circuit board processes are typically used to produce planar devices. A 1.8 to 11 GHz two-arm planar log-periodic antenna is designed with a monolithically integrated impedance transformer. Band rejection methods based on modifying the antenna aperture, use of an integrated filter, and the application of both methods are investigated with realized gain suppressions of over 25 dB achieved. The ability of standard circuit board technology to fabricate millimeter-wave devices up to 110 GHz is severely limited. Thin dielectrics are required to prevent the excitation of higher order modes in the microstrip substrate. Fabricating the thin line widths required for the antenna aperture also becomes prohibitively challenging. Surface micro-machining typically used in the fabrication of MEMS devices is capable of producing the extremely small features that can be used to fabricate antennas extending through W-band. A directly RF fed 18 to 110 GHz planar log-periodic antenna is developed. The antenna is fabricated with an integrated impedance transformer and additional transitions for measurement characterization. Singly terminated low-loss wideband millimeter-wave filters operating over V- and W- band are developed. High

  14. Monolitni katalizatori i reaktori: osnovne značajke, priprava i primjena (Monolith catalysts and reactors: preparation and applications

    Directory of Open Access Journals (Sweden)

    Tomašić, V.

    2004-12-01

    Full Text Available Monolithic (honeycomb catalysts are continuous unitary structures containing many narrow, parallel and usually straight channels (or passages. Catalytically active components are dispersed uniformly over the whole porous ceramic monolith structure (so-called incorporated monolithic catalysts or are in a layer of porous material that is deposited on the walls of channels in the monolith's structure (washcoated monolithic catalysts. The material of the main monolithic construction is not limited to ceramics but includes metals, as well. Monolithic catalysts are commonly used in gas phase catalytic processes, such as treatment of automotive exhaust gases, selective catalytic reduction of nitrogen oxides, catalytic removal of volatile organic compounds from industrial processes, etc. Monoliths continue to be the preferred support for environmental applications due to their high geometric surface area, different design options, low pressure drop, high temperature durability, mechanical strength, ease of orientation in a reactor and effectiveness as a support for a catalytic washcoat. As known, monolithic catalysts belong to the class of the structured catalysts and/or reactors (in some cases the distinction between "catalyst" and "reactor" has vanished. Structured catalysts can greatly intensify chemical processes, resulting in smaller, safer, cleaner and more energy efficient technologies. Monolith reactors can be considered as multifunctional reactors, in which chemical conversion is advantageously integrated with another unit operation, such as separation, heat exchange, a secondary reaction, etc. Finally, structured catalysts and/or reactors appear to be one of the most significant and promising developments in the field of heterogeneous catalysis and chemical engineering of the recent years. This paper gives a description of the background and perspectives for application and development of monolithic materials. Different methods and techniques

  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. 29 CFR 1915.1017 - Vinyl chloride.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Vinyl chloride. 1915.1017 Section 1915.1017 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... § 1915.1017 Vinyl chloride. Note: The requirements applicable to shipyard employment under this...

  17. 29 CFR 1926.1117 - Vinyl chloride.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Vinyl chloride. 1926.1117 Section 1926.1117 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Toxic and Hazardous Substances § 1926.1117 Vinyl chloride. Note: The requirements applicable to construction work under this section are identical to...

  18. 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

  19. 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...

  20. Fractionation of bamboo hemicelluloses by graded saturated ammonium sulphate.

    Science.gov (United States)

    Guan, Ying; Zhang, Bing; Qi, Xian-Ming; Peng, Feng; Yao, Chun-Li; Sun, Run-Cang

    2015-09-20

    The hemicelluloses were isolated with 10% KOH at 25°C from dewaxed and delignified bamboo powder. The alkali-soluble hemicelluloses from Sinocalamus affinis were fractionated by ammonium sulphate precipitation method. The bamboo alkali-soluble hemicelluloses yielded seven hemicellulosic fractions obtained at 0, 5, 15, 25, 40, 55, and 70% saturation with ammonium sulphate. It was found that the more branched hemicelluloses were precipitated at higher ammonium sulphate concentrations (55 and 70%), the more linear hemicelluloses were precipitated at lower ammonium sulphate concentrations (0, 5, 15, 25, and 40%). The molecular weights of hemicellulosic fractions become lower from 35,270 (H0) to 18,680 (H70)gmol(-1) with the increasing concentrations of saturated ammonium sulphate from 0 to 70%. Based on the FT-IR, (1)H, (13)C and 2D HSQC NMR studies, the alkali-soluble hemicelluloses were 4-O-methyl-glucuronoarabinoxylans composed of the (1→4)-linked β-d-xylopyranosyl backbone with branches at O-3 of α-L-arabinofuranosyl or at O-2 of 4-O-methyl-α-d-glucuronic acid.