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Sample records for sodium aluminate solutions

  1. Novel synthesis of gibbsite by laser-stimulated nucleation in supersaturated sodium aluminate solutions

    Science.gov (United States)

    Blanks, K. A.

    2000-12-01

    Laser-induced localized density fluctuations are shown to stimulate primary nucleation of nano-sized aluminum trihydroxide seed crystals in flowing supersaturated industrial sodium aluminate solutions (Bayer liquor). The post-nucleation mass deposition rate is greatly increased over rates attainable through more traditional seeding methods. Near-ideal single-crystal gibbsite is formed under diffusion-limited growth conditions. Laser-stimulated nucleation represents an in situ method for the active local modulation of the supersaturation state, so that the stimulated nucleation occurs under macroscopic solution conditions that are unfavorable for spontaneous nucleation.

  2. Solubilities of sodium nitrate, sodium nitrite, and sodium aluminate in simulated nuclear waste

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, D.A.; Herting, D.L.

    1984-09-01

    Solubilities were determined for sodium nitrate, sodium nitrite, and sodium aluminate in synthetic nuclear waste liquor. Solubilities were determined as a function of temperature and solution composition (concentrations of sodium hydroxide, sodium nitrate, sodium nitrite, and sodium aluminate). Temperature had the greatest effect on the solubilities of sodium nitrate and sodium nitrite and a somewhat lesser effect on sodium aluminate solubility. Hydroxide had a great effect on the solubilities of all three salts. Other solution components had minor effects. 2 references, 8 figures, 11 tables.

  3. Kinetics and mechanism of desilication reaction in sodium chromate solution using sodium aluminate.

    Science.gov (United States)

    Chen, Jianxin; Zhang, Xiangchao; Han, Jian; Li, Yinhui; Su, Min; Lu, Aidang

    2017-04-01

    It is essential to control silica levels in sodium chromate solution during the process of electrolytic synthesis of sodium dichromate. On the basis of previous work, the desilication conditions were systematically studied and pH was found to have the most serious impact on the desilication process. The desilication rate under optimal conditions obtained from the orthogonal experiment results was up to 99.3%. Kinetic experiments showed that the desilication reaction was first-order in SiO 2 concentration and the apparent activation energy was calculated to be 22 kJ mol -1 , which is far less than the reported values. The morphology and structure of the desilication reaction product (DSP) were studied by scanning electron microscope (SEM) and X-ray diffraction (XRD). SEM showed that DSP had a loose etched structure. The pattern of XRD illustrated the crystallinity of DSP increased along the duration of the experiment. The phase of DSP was mainly Na 6 (AlSiO 4 ) 6 . Based on the experimental data, the desilication mechanism has been discussed. The hexameric aluminosilicate ions were produced by the reaction of monomeric aluminosilicate ion, through hydrogen bond interaction, which was formed by SiO 2 (OH) 2 2- and Al(OH) 4 - .

  4. Stabilization of aqueous alkali metal aluminate solutions

    Energy Technology Data Exchange (ETDEWEB)

    Allenson, S.J.

    1988-03-29

    A method of stabilizing an aqueous solution of alkali metal aluminate is described comprising: admixing an aqueous solution of alkali metal aluminate having a pH of at least 10 with a sufficient amount of vinyl polymer having pendant carboxylate groups to form a solution containing from 0.1 to 2.0 weight percent of an anionic vinyl polymer based on alkali metal aluminate solids. The anionic vinyl polymer has an average molecular weight of at least 500,000.

  5. THE MECHANISM OF BONDING PARTICLES DISTENSILIMANITA SODIUM ALUMINATE

    Directory of Open Access Journals (Sweden)

    O. S. Komarov

    2016-01-01

    Full Text Available The interaction of the filler (distensillimanit or binder (sodium aluminate after mixing them to form a mold wash, drying the paint and removing water of crystallization. The conclusion of the sodium aluminate suitability as a foundry binder paints.

  6. Destruction of filtration incrustations of aluminate clay solutions

    Energy Technology Data Exchange (ETDEWEB)

    Galyan, D.A.; Tarnavskii, A.P.; Lizogub, G.D.

    1977-05-01

    Research results are presented for determining the optimal hydrochemical action time of a buffer fluid (10% NaOH solution) that is needed to destroy filtration incrustations of aluminate clay solutions with respect to the effect of a buffer fluid and an aluminate clay solution on the properties of plugging solutions. Fundamental recommendations are made with respect to using 10% NaOH solutions for removing aluminate clay solution filtration incrustations. 1 table.

  7. Sodium leak detection on large pipes. Heat insulating shells made of silico-aluminate

    International Nuclear Information System (INIS)

    Antonakas, D.; Blanc, R.; Casselman, C.; Malet, J.C.

    1986-05-01

    This report presents an equipment installed on the large secondary pipes of fast reactors, ensuring several functions: support and equilibrium of static and dynamic loads, heat insulator, preheating, and the detection of possible sodium leaks. The research programs associated to the development of the shells are briefly evoked; then, the report deals no longer with the studies on silico-aluminate aging and the detection performance [fr

  8. Preparation of High-purity Lactulose through Efficient Recycle of Catalyst Sodium Aluminate and Nanofiltration: A Pilot-scale Purification.

    Science.gov (United States)

    Wang, Mingming; Tessema, Habtamu Admassu; Gasmalla, Mohammed A A; Hua, Xiao; Yang, Ruijin

    2018-04-16

    Lactulose, a valuable lactose-originated "bifidus factor" product, is exclusively produced by chemical-based isomerization commercially. Complexing agent of sodium aluminate exhibited high conversion efficiency and strong recyclable stability is more practical for industrial applications. In this study, efficient purification of high-purity lactulose through recycling of sodium aluminate and further desalination by nanofiltration (NF) was implemented in a pilot scale. Over 99.5% of catalyst was prior recycled in the form of Al(OH) 3 precipitate by pH-induced precipitation and centrifugation, residual aluminum was further absorbed by ion exchange resin to an acceptable level (≤10 mg Kg -1 ). Subsequently, impurities (monosaccharides and NaCl) were ideally separated from lactulose syrup by NF process based on their significant retention differences (lactulose: 94.8-97.2%> lactose: 86.2-93.5%> monosaccharides: 36.3-48.7%> NaCl: 9.5-31.1%). High-purity (>95 %) lactulose was obtained with yield >90% in both constant and variable volume diafiltration modes (CVD/VVD) when volume dilution ratio (V c /V f ) was 4.0 and 2.5, respectively. Both experimental and predicted results showed that VVD mode was more water-saving in practical. This is the first trial purification of lactulose syrup from chemical isomerization of lactose catalyzed by sodium aluminate, and the applied methodology is a promising industrial scale purification strategy. This article is protected by copyright. All rights reserved.

  9. Cromolyn Sodium Nasal Solution

    Science.gov (United States)

    Cromolyn comes as a solution to use with a special nasal applicator. It usually is inhaled three to six times a day to prevent allergy ... first time, read the instructions provided with the solution. Ask your doctor, pharmacist, or respiratory therapist to ...

  10. Electrochemical Recovery of Sodium Hydroxide from Alkaline Salt Solution

    Energy Technology Data Exchange (ETDEWEB)

    Hobbs, D.T. [Westinghouse Savannah River Company, AIKEN, SC (United States); Edwards, T.B.

    1996-10-01

    A statistically designed set of tests determined the effects of current density, temperature, and the concentrations of nitrate/nitrite, hydroxide and aluminate on the recovery of sodium as sodium hydroxide (caustic) from solutions simulating those produced from the Savannah River Site (SRS) In-Tank Precipitation process. These tests included low nitrate and nitrite concentrations which would be produced by electrolytic nitrate/nitrite destruction. The tests used a two compartment electrochemical cell with a Nafion Type 324 ion-exchange membrane. Caustic was successfully recovered from the waste solutions. Evaluation of the testing results indicated that the transport of sodium across the membrane was not significantly affected by any of the varied parameters. The observed variance in the sodium flux is attributed to experimental errors and variations in the performance characteristics of individual pieces of the organic-based Nafion membrane.Additional testing is recommended to determine the maximum current density, to evaluate the chemical durability of the organic membrane as a function of current density and to compare the durability and performance characteristics of the organic-based Nafion membrane with that of other commercially available organic membranes and the inorganic class of membranes under development by Ceramatec and PNNL.

  11. Solution processed lanthanum aluminate gate dielectrics for use in metal oxide-based thin film transistors

    Energy Technology Data Exchange (ETDEWEB)

    Esro, M.; Adamopoulos, G., E-mail: g.adamopoulos@lancaster.ac.uk [Engineering Department, Lancaster University, Lancaster LA1 4YR (United Kingdom); Mazzocco, R.; Kolosov, O.; Krier, A. [Physics Department, Lancaster University, Lancaster, LA1 4YB (United Kingdom); Vourlias, G. [Physics Department, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Milne, W. I. [Department of Engineering, University of Cambridge, 9 JJ Thomson Avenue, Cambridge CB3 0FA (United Kingdom); Department of Electrical and Computing Engineering, University of Canterbury, 4800 Christchurch (New Zealand)

    2015-05-18

    We report on ZnO-based thin-film transistors (TFTs) employing lanthanum aluminate gate dielectrics (La{sub x}Al{sub 1−x}O{sub y}) grown by spray pyrolysis in ambient atmosphere at 440 °C. The structural, electronic, optical, morphological, and electrical properties of the La{sub x}Al{sub 1−x}O{sub y} films and devices as a function of the lanthanum to aluminium atomic ratio were investigated using a wide range of characterization techniques such as UV-visible absorption spectroscopy, impedance spectroscopy, spectroscopic ellipsometry, atomic force microscopy, x-ray diffraction, and field-effect measurements. As-deposited LaAlO{sub y} dielectrics exhibit a wide band gap (∼6.18 eV), high dielectric constant (k ∼ 16), low roughness (∼1.9 nm), and very low leakage currents (<3 nA/cm{sup 2}). TFTs employing solution processed LaAlO{sub y} gate dielectrics and ZnO semiconducting channels exhibit excellent electron transport characteristics with hysteresis-free operation, low operation voltages (∼10 V), high on/off current modulation ratio of >10{sup 6}, subthreshold swing of ∼650 mV dec{sup −1}, and electron mobility of ∼12 cm{sup 2} V{sup −1} s{sup −1}.

  12. Effect of Tartaric Acid on Hydration of a Sodium-Metasilicate-Activated Blend of Calcium Aluminate Cement and Fly Ash F

    Directory of Open Access Journals (Sweden)

    Tatiana Pyatina

    2016-05-01

    Full Text Available An alkali-activated blend of aluminum cement and class F fly ash is an attractive solution for geothermal wells where cement is exposed to significant thermal shocks and aggressive environments. Set-control additives enable the safe cement placement in a well but may compromise its mechanical properties. This work evaluates the effect of a tartaric-acid set retarder on phase composition, microstructure, and strength development of a sodium-metasilicate-activated calcium aluminate/fly ash class F blend after curing at 85 °C, 200 °C or 300 °C. The hardened materials were characterized with X-ray diffraction, thermogravimetric analysis, X-ray computed tomography, and combined scanning electron microscopy/energy-dispersive X-ray spectroscopy and tested for mechanical strength. With increasing temperature, a higher number of phase transitions in non-retarded specimens was found as a result of fast cement hydration. The differences in the phase compositions were also attributed to tartaric acid interactions with metal ions released by the blend in retarded samples. The retarded samples showed higher total porosity but reduced percentage of large pores (above 500 µm and greater compressive strength after 300 °C curing. Mechanical properties of the set cements were not compromised by the retarder.

  13. Standard partial molar heat capacities and enthalpies of formation of aqueous aluminate under hydrothermal conditions from integral heat of solution measurements

    International Nuclear Information System (INIS)

    Coulier, Yohann; Tremaine, Peter R.

    2014-01-01

    Highlights: • Heats of solution of NaAlO 2 (s) were measured at five temperatures up to 250 °C. • Standard molar enthalpies of solution were determined from the measured heats of solution. • Standard molar enthalpies of solution were correlated with the density model. • The density model allows us to determine the standard molar heat capacities of reaction. - Abstract: Heats of solution of sodium aluminum oxide, NaAlO 2 (s), were measured in aqueous sodium hydroxide solutions using a Tian–Calvet heat-flow calorimeter (Setaram, Model C80) with high pressure “batch cells” made of hastelloy C-276, at five temperatures from (373.15 to 523.15) K, steam saturation pressure, and concentrations from (0.02 to 0.09) mol · kg −1 . Standard molar enthalpies of solution, Δ soln H ∘ , and relative standard molar enthalpies, [H ∘ (T) − H ∘ (298.15 K)], of NaAl(OH) 4 (aq) were determined from the measured heats of solution. The results were fitted with the “density” model. The temperature dependence of Δ soln H ∘ from the model yielded the standard molar heat capacities of reaction, Δ soln C p ∘ , from which standard partial molar heat capacities for aqueous aluminate, C p ∘ [A1(OH) 4 − ,aq], were calculated. Standard partial molar enthalpies of formation, Δ f H ∘ , and entropies, S ∘ , of A1(OH) 4 − (aq) were also determined. The values for C p ∘ [A1(OH) 4 − ,aq] agree with literature data determined up to T = 413 K from enthalpy of solution and heat capacity measurements to within the combined experimental uncertainties. They are consistent with differential heat capacity measurements up to T = 573 K from Schrödle et al. (2010) [29] using the same calorimeter, but this method has the advantage that measurements could be made at much lower concentrations in the presence of an excess concentration of ligand. To our knowledge, these are the first standard partial molar heat capacities measured under hydrothermal conditions by the

  14. Use of sodium aluminate in waste water treatment plants: wishes of saving money and innovating; Uso del aluminato sodico en las EDAR: una propuesta para innovar y economizar costes de explotacion

    Energy Technology Data Exchange (ETDEWEB)

    Humbert Fernandez, F.; Delgado Espinola, G.; Soler Cantalosella, M.; Dalman Martori, E.; Iranzo Blasco, C.; Sanz Torrejon, A.

    2006-07-01

    Most waste water treatment plants have processes to remove nutrients in order to avoid eutrophication in water receiving bodies. Regarding phosphorus removal. the most common option is chemical precipitation with ferric or aluminical precipitation with ferric or aluminium salts. We show here the successful experience carried out by the WWTP of Blanes and the company Safloc. A method ato remove phosphorus from waste water was developed by adding sodium aluminate. The use of this compound has turned out to be a sustainable way for this purpose in terms of costs, reliability and minimization of sludge production. (Author)

  15. Actinide-aluminate Speciation in Alkaline Radioactive Waste

    International Nuclear Information System (INIS)

    Clark, David C.; Krot, Nikolai N.

    2000-01-01

    Highly alkaline radioactive waste tanks contain a number of transuranic species, in particular U, Np, Pu, and Am-the exact forms of which are currently unknown. Knowledge of actinide speciation under highly alkaline conditions is essential towards understanding and predicting their solubility and sorption behavior in tanks, determining whether chemical separations are needed for waste treatment, and designing separations processes. Baseline washing of tank sludges with NaOH solutions is being proposed to reduce the volume of HLW. Alkaline pretreatment of HLW will be needed to remove aluminum [as NaAl(OH)4] because it significantly reduces the HLW volume; however, the aluminate ion [Al(OH)4 -] enhances actinide solubility via an unknown mechanism. Thus, alkaline wash residues may require an additional treatment to remove actinides. The results of this research will determine the nature TRU (U, Np, Pu, Am) speciation with aluminate anions under alkaline, oxidizing tank-like conditions. Specific issues to be addressed include solubility of these actinides, speciation in aluminate-containing alkaline supernatants, the role of actinide redox states on solubility, and partitioning between supernatant and solid phases, including colloids. Studies will include thermodynamics, kinetics, spectroscopy, electrochemistry, and surface science. We have already determined, for example, that certain high valent forms of Np and Pu are very soluble under alkaline conditions due to the formation of anionic hydroxo complexes, AnO2(OH)4 2- and AnO2(OH)5 3-. The presence of aluminate ions causes the actinide solubilities to increase, although the exact species are not known. We are currently characterizing the high valent TRU elements bound to oxo, water, OH-, and Al(OH)4 -, ligands under waste-like conditions. These waste-like conditions are in the range of 1-3 M excess hydroxide, ∼0.2 M carbonate, ∼0.5 M aluminate, for a total sodium of 2-4 M. Molecular structure-specific probes

  16. 46 CFR 153.1065 - Sodium chlorate solutions.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Sodium chlorate solutions. 153.1065 Section 153.1065... Procedures § 153.1065 Sodium chlorate solutions. (a) No person may load sodium chlorate solutions into a... solutions are immediately washed away. Approval of Surveyors and Handling of Categories A, B, C, and D Cargo...

  17. Viscosity and density tables of sodium chloride solutions

    Energy Technology Data Exchange (ETDEWEB)

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

    1977-04-01

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

  18. Volumetric determination of hydroxide, aluminate, and carbonate in alkaline solutions of nuclear waste

    International Nuclear Information System (INIS)

    Baumann, E.W.

    1975-06-01

    An integrated procedure was developed for determining OH - , Al(OH) 4 - , and CO 3 2- in alkaline nuclear waste. The free alkali, the hydroxide released when Al(OH) 3 is complexed with oxalate, and the precipitated BaCO 3 were determined by acidimetric titration. With a 50-μl sample, the relative standard deviations were 1 to 2 percent for nonradioactive test solutions and 2 to 5 percent for radioactive process solutions. (U.S.)

  19. Suppressive effects of a polymer sodium silicate solution on ...

    African Journals Online (AJOL)

    Sodium silicate was dissolved in water in either a monomer form or polymer form; the effects of both forms of sodium silicate aqueous solution on rose powdery mildew and root rot diseases of miniature rose were examined. Both forms of sodium silicate aqueous solution were applied to the roots of the miniature rose.

  20. 21 CFR 522.1610 - Oleate sodium solution.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Oleate sodium solution. 522.1610 Section 522.1610 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Oleate sodium solution. (a) Specifications. Each milliliter of sterile aqueous solution contains 50...

  1. The Use of Alum Mixtures for Removal and Decontamination of VX and QL In Aqueous Solutions

    National Research Council Canada - National Science Library

    Williams, Daniel J; Bevilacqua, Vicky L; Creasy, William R; McGarvey, David J; Rice, Jeffrey S; DeLeon, Christopher L; Sanders, Melanie J; Durst, H. D

    2004-01-01

    ...), were treated with aqueous aluminum sulfate (alum), sodium aluminate, or mixtures of the two. The mixtures were prepared by combining varying volumes of the aqueous salts to give buffered solutions (pH 2-12...

  2. Stability of sodium bicarbonate solutions in polyolefin bags.

    Science.gov (United States)

    Wear, Jennifer; McPherson, Timothy B; Kolling, William M

    2010-06-15

    The stability of sodium bicarbonate solutions in sterile water for injection or 5% dextrose injection stored at 21-24 degrees C or 2-4 degrees C was evaluated. Sodium bicarbonate injection was obtained in 50-mL vials of 8.4% (1 meq/mL). A total of 50, 100, or 150 meq of sodium bicarbonate was added to each 1-L polyolefin bag of either sterile water for injection or 5% dextrose injection. All solutions were prepared in a laminar-airflow hood using aseptic technique. Bags were punctured once to remove headspace air and once for the addition of each 50 meq of sodium bicarbonate. Six replicates of each test solution were prepared. The solutions were stored at 21-24 degrees C and 2-4 degrees C. Control solutions (50 and 150 meq) were similarly prepared in triplicate. Control solutions were sparged with either nitrogen gas or oxygen gas before storage. Sodium bicarbonate stability was assessed by measuring solution pH. Bicarbonate content was measured utilizing titration. Both pH and bicarbonate concentrations were measured immediately upon preparation and on days 3, 5, and 7 for both test and control solutions. All 95% confidence interval values for sample solution pH remained within 7.0-8.5 for seven days at 2-4 degrees C. Sodium bicarbonate solutions of 50, 100, and 150 meq in sterile water for injection or 5% dextrose injection were stable for up to seven days when refrigerated. The 50-meq solution was stable for up to 48 hours when stored at room temperature, and the 100- and 150-meq solutions were stable for up to 30 hours when stored at room temperature.

  3. Tetragonal Chicken Egg White Lysozyme Solubility in Sodium Chloride Solutions

    Science.gov (United States)

    Forsythe, Elizabeth L.; Judge, Russell A.; Pusey, Marc L.

    1998-01-01

    The solubility of chicken egg white lysozyme, crystallized in the tetragonal form was measured in sodium chloride solutions from 1.6 to 30.7 C, using a miniature column solubility apparatus. Sodium chloride solution concentrations ranged from 1 to 7% (w/v). The solutions were buffered with 0.1 M sodium acetate buffer with the solubility being measured at pH values in 0.2 pH unit increments in the range pH 4.0 to 5.4, with data also included at pH 4.5. Lysozyme solubility was found to increase with increases in temperature and decreasing salt concentration. Solution pH has a varied and unpredictable effect on solubility.

  4. Aggregation of sodium alkylbenzenesulfonates in aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Magid, L.J.; Shaver, R.J.; Gulari, E.; Bedwell, B.; Alkhafaji, S.

    1981-01-01

    The surfactant 6 phenyl C/sub 12/SNa forms small spherical micelles in aqueous solution, having an aggregation number of 20 to 30 and a fractional charge of 0.45. These micelles are hydrated to the extent of approximately 18 moles H/sub 2/O per moles of surfactant. A second larger aggregate is also present in 6 phenyl C/sub 12/SNa solutions; its importance increases with solution age. Addition of NaCl causes both aggregates to apparently increase modestly in size. The surfactant 8 phenyl C/sub 16/SNa also contains both aggregates in its solutions; the larger one is relatively more important here. The larger aggregate does not correspond to dispersed bits of a liquid crystalline mesophase.

  5. Study of the interactions between alumina and metallic ion in solution at the liquid/oxide interface during catalysts synthesis; Etude des interactions alumine/ion metallique en solution a l`interface oxyde/liquide lors de la preparation des catalyseurs

    Energy Technology Data Exchange (ETDEWEB)

    Mertens de Wilmars, D.

    1998-01-15

    This work concerns the formation of compounds including metal and Al(III) ions during impregnation of gamma alumina with a solution of the metal precursor. Formation of Li/Al hydroxy-carbonate (Li/Al HDC) on alumina during impregnation by a neutral or basic solution containing Li{sup +} is established. Zeta potential measurements are used to determine the ratio overlay of the alumina by HDC Li/Al. By this technique, residual positive charges are observed on HDC Li/Al surface. The formation of two different compounds including Mo(VI) and Al(III) ions during impregnation of alumina with molybdate or hepta-molybdate solution is reported here for the first time. The use of sodium molybdate solution as impregnation precursor leads to the formation of hydroxy-molybdo-luminate, while the ammonium hepta-molybdate solution forms ammonium hexa-molybdo-aluminate by contact with alumina.Dissolution kinetics of alumina in aqueous solution in absence or in presence of metal ions (Li{sup +}, K{sup +}, Zn{sup 2+}, MoO{sub 4}{sup 2-}, Mo{sub 7}O{sub 24}{sup 6-}) are investigated at different pH. Results show that the support is not inert in aqueous solution, even at neutral pH (near ZPC). The homogeneous nucleation of Li/Al HDC observed for Li/Al{sub 2}O{sub 3} system evidence the permeability of the solid/solution interface: diffusion processus through the interface is more important than previously reported. A dissolution-precipitation mechanism is proposed to account for the formation of Al(III)-containing compounds on alumina surface. Alumina dissolves when contacted with aqueous solution. When Al(III) ions concentration in solution is bigger than the sur-saturation needed for heterogenous nucleation of the Al(III) containing compounds, this one precipitates. This mechanism agrees with all our results. (author) 169 refs.

  6. Reactive Air Aluminization

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jung-Pyung; Chou, Y. S.; Stevenson, Jeffry W.

    2011-10-28

    Ferritic stainless steels and other alloys are of great interest to SOFC developers for applications such as interconnects, cell frames, and balance of plant components. While these alloys offer significant advantages (e.g., low material and manufacturing cost, high thermal conductivity, and high temperature oxidation resistance), there are challenges which can hinder their utilization in SOFC systems; these challenges include Cr volatility and reactivity with glass seals. To overcome these challenges, protective coatings and surface treatments for the alloys are under development. In particular, aluminization of alloy surfaces offers the potential for mitigating both evaporation of Cr from the alloy surface and reaction of alloy constituents with glass seals. Commercial aluminization processes are available to SOFC developers, but they tend to be costly due to their use of exotic raw materials and/or processing conditions. As an alternative, PNNL has developed Reactive Air Aluminization (RAA), which offers a low-cost, simpler alternative to conventional aluminization methods.

  7. Solution combustion synthesis of strontium aluminate, SrAl2O4, powders: single-fuel versus fuel-mixture approach.

    Science.gov (United States)

    Ianoş, Robert; Istratie, Roxana; Păcurariu, Cornelia; Lazău, Radu

    2016-01-14

    The solution combustion synthesis of strontium aluminate, SrAl2O4, via the classic single-fuel approach and the modern fuel-mixture approach was investigated in relation to the synthesis conditions, powder properties and thermodynamic aspects. The single-fuel approach (urea or glycine) did not yield SrAl2O4 directly from the combustion reaction. The absence of SrAl2O4 was explained by the low amount of energy released during the combustion process, in spite of the highly negative values of the standard enthalpy of reaction and standard Gibbs free energy. In the case of single-fuel recipes, the maximum combustion temperatures measured by thermal imaging (482 °C - urea, 941 °C - glycine) were much lower than the calculated adiabatic temperatures (1864 °C - urea, 2147 °C - glycine). The fuel-mixture approach (urea and glycine) clearly represented a better option, since (α,β)-SrAl2O4 resulted directly from the combustion reaction. The maximum combustion temperature measured in the case of a urea and glycine fuel mixture was the highest one (1559 °C), which was relatively close to the calculated adiabatic temperature (1930 °C). The addition of a small amount of flux, such as H3BO3, enabled the formation of pure α-SrAl2O4 directly from the combustion reaction.

  8. ACTINIDE-ALUMINATE SPECIATION IN ALKALINE RADIOACTIVE WASTE

    International Nuclear Information System (INIS)

    Clark-Deaborg, David

    2001-01-01

    Highly alkaline radioactive waste tanks contain a number of transuranic species, in particular U, Np, Pu, and Am--the exact forms of which are currently unknown. Knowledge of actinide speciation under highly alkaline conditions is essential towards understanding and predicting their solubility and sorption behavior in tanks, determining whether chemical separations are needed for waste treatment, and designing separations processes. Baseline washing of tank sludges with NaOH solutions is being proposed to reduce the volume of HLW. Alkaline pretreatment of HLW will be needed to remove aluminum [as NaAl(OH) 4 ] because it significantly reduces the HLW volume; however, aluminate [Al(OH) 4 - ] enhances actinide solubility via an unknown mechanism. Thus, alkaline wash residues may require an additional treatment to remove actinides. The results of this research will determine the nature TRU (Np, Pu, Am) speciation with aluminate anions under alkaline, oxidizing tank-like conditions. Specific issues to be addressed include solubility of these actinides, speciation in aluminate-containing alkaline supernatants, the role of actinide redox states on solubility, and partitioning between supernatant and solid phases, including colloids. Studies will include thermodynamics, kinetics, spectroscopy, electrochemistry, etc. It is already known, for example, that certain high valent forms of NF and Pu are very soluble under alkaline conditions due to the formation of anionic hydroxo complexes, AnO 2 (OH) 4 2- and AnO 2 (OH) 5 3- . The presence of aluminate ions causes the actinide solubilities to increase, although the exact species have only been determined during this program. We are continuing to characterize high-valent TRU elements bound to oxo, water, OH - , under waste-like and sludge washing conditions. These conditions are in the range of 1-3 M excess hydroxide, ∼0.2 M carbonate, ∼0.5 M aluminate, for a total sodium of 2-4 mols/kg. Molecular structure-specific probes

  9. On the texturization of monocrystalline silicon with sodium carbonate solutions

    Energy Technology Data Exchange (ETDEWEB)

    Vallejo, B.; Gonzalez-Manas, M.; Martinez-Lopez, J.; Caballero, M.A. [Departamento de Cristalografia, Facultad de Ciencias, Universidad de Cadiz, 11510 Puerto Real (Spain)

    2007-05-15

    The texturization of monocrystalline silicon wafers using sodium carbonate solution has been investigated. This etching process has been evaluated in terms of the surface morphology and the reflectance value. The results show that for low concentration of sodium carbonate the increase of texturing time decreases the reflectance value because of the change in morphology from hillocks to pyramidal; on the contrary for intermediate and high concentrations the increase of time has a detrimental effect on texturization because it increases both the pyramid sizes and their non-uniform distribution. However, a good cell performance could be obtained by etching at high concentrations and short times. (author)

  10. Extraction of tritium from lithium aluminate

    International Nuclear Information System (INIS)

    Yunker, W.

    1976-09-01

    Complete data are presented for the extraction of tritium from neutron irradiated lithium aluminate pellets. Two methods were used: (a) thermal/vacuum extraction at temperatures up to 980 0 C and (b) dissolution of the pellets in sodium tetraborate at 850 0 C followed by vacuum extraction. Approximately 1 percent of the tritium was in a noncondensable (at -195 0 C and 10 -3 torr) form. Extraction efficiency was greater than 95 percent

  11. Extraction of tritium from lithium aluminate

    Energy Technology Data Exchange (ETDEWEB)

    Yunker, W [ed.

    1976-09-01

    Complete data are presented for the extraction of tritium from neutron irradiated lithium aluminate pellets. Two methods were used: (a) thermal/vacuum extraction at temperatures up to 980/sup 0/C and (b) dissolution of the pellets in sodium tetraborate at 850/sup 0/C followed by vacuum extraction. Approximately 1 percent of the tritium was in a noncondensable (at -195/sup 0/C and 10/sup -3/ torr) form. Extraction efficiency was greater than 95 percent.

  12. The radiation chemistry of aqueous sodium terephthalate solutions

    International Nuclear Information System (INIS)

    Matthews, R.W.

    1980-04-01

    The radiation chemistry of cobalt-60 gamma-irradiated aqueous sodium terephthalate solutions has been studied. In aerated 4 x 10 -4 M sodium hydroxide solutions, the main products are hydroxyterephthalate (HTA) (G = 0.99 +- 0.01), carbonate (G = 1.31 +- 0.08), and peroxides (G = 2.84 +- 0.04). The HTA and carbonate species are both formed as a result of hydroxyl radical attack and account for approximately 90 per cent of hydroxyl radical reactions. Oxygen needs to be present for efficient conversion of the terephthalate-OH radical adduct to HTA and oxygenation increases G(HTA) above the aerated solution value. G(HTA) is unaffected by changes in terephthalate concentration between 1 x 10 -4 M and 1 x 10 -2 M in sodium hydroxide solutions at pH 10. Decreasing the solution pH does however affect G(HTA). In phosphate buffered solutions pH 6.85, G(HTA) is 0.93 +- 0.01 and lower values are obtained with further decrease in solution pH. The lowering of the G(HTA) value is attributed to recombination reactions between the terephthalate-OH radical products and reducing radical products. Experimental evidence supporting the recombination postulate was obtained from the measurement of a parallel decrease in the peroxide yield and the observation of a dose rate effect on G(HTA). Competition kinetic studies with the added solutes carbonate and bicarbonate gave the rate ratios k (OH + TA 2- ) : k(OH + CO 3 2- ) : k(OH + HCO 3 - ) = 1 : 0.105 : 0.0036

  13. Sodium tetraphenylborate solution stability: A long term study

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, M.J.

    1992-06-11

    Sodium tetraphenylborata (NaTPB) is a specialty chemical required for the In Tank Precipitation Process (ITP). It precipitates cesium, aiding in the decontamination of high level radioactive waste solutions. Long term stability of aqueous alkaline solutions of NATPB has been investigated. The focus of the investigation is on the relative stabilities of NATPB solutions exposed to varying temperatures and copper concentrations over an extended period of time. Additionally, vendor-supplied samples, incubated at 40{degree}C, were stored for more than a year without decomposing. Collected data demonstrates that in the absence of elevated copper concentrations, NATPB solutions will remain stable for periods of 1 to 2 years (at a minimum) at maximum expected operating conditions (<40{degree}C). Additionally, biuret, (H{sub 2}NCO){sub 2}NH, was tested as an additive to prevent copper-induced decomposition without success.

  14. Sodium tetraphenylborate solution stability: A long term study

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, M.J.

    1992-06-11

    Sodium tetraphenylborata (NaTPB) is a specialty chemical required for the In Tank Precipitation Process (ITP). It precipitates cesium, aiding in the decontamination of high level radioactive waste solutions. Long term stability of aqueous alkaline solutions of NATPB has been investigated. The focus of the investigation is on the relative stabilities of NATPB solutions exposed to varying temperatures and copper concentrations over an extended period of time. Additionally, vendor-supplied samples, incubated at 40[degree]C, were stored for more than a year without decomposing. Collected data demonstrates that in the absence of elevated copper concentrations, NATPB solutions will remain stable for periods of 1 to 2 years (at a minimum) at maximum expected operating conditions (<40[degree]C). Additionally, biuret, (H[sub 2]NCO)[sub 2]NH, was tested as an additive to prevent copper-induced decomposition without success.

  15. 21 CFR 520.2261a - Sulfamethazine sodium drinking water solution.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sulfamethazine sodium drinking water solution. 520....2261a Sulfamethazine sodium drinking water solution. (a) Sponsors. See Nos. 000010 and 061623 in § 510.600(c) of this chapter for use of a 12.5-percent sulfamethazine sodium solution. (b) Related...

  16. Measurements of the viscosity of sodium tetraborate (borax)-UO2 and of sodium metaborate-UO2 liquid solutions

    International Nuclear Information System (INIS)

    Dalle Donne, M.; Dorner, S.; Roth, A.

    1983-01-01

    Adding UO 2 produces an increase of viscosity of borax and sodium metaborate. For temperatures below 920 0 C the measurements with the borax-UO 2 solution show a phase separation. Contrary to borax the sodium metaborate solutions indicate a well defined melting point. At temperatures slightly below the melting point a solid phase is formed. The tested sodium-borates-UO 2 mixtures are in liquid form. (DG)

  17. Behaviour of wetting films of sodium hyaluronate saline solutions.

    Science.gov (United States)

    Ribeiro, Walkíria; Orfão, Marta; Mata, José Luís; Saramago, Benilde

    2008-01-15

    The behaviour of wetting films of sodium hyaluronate (NaHA) saline solutions, at physiological conditions, is investigated using interferometry. Concentrations in the range of dilute and semi-dilute regimes were chosen to assess the role of bulk molecular interactions on the surface forces. The transition from dilute to semi-dilute solutions is known to occur at c*=0.59 mg mL(-1). Dilute solutions form stable films whose behaviour is explained by van der Waals interactions. For semi-dilute solutions, the disjoining pressure vs film thickness isotherms show branches attributed to stepwise thinning or film stratification, which is interpreted in terms of a network as predicted by the theory of semi-dilute polyelectrolyte solutions. The distance between branches is 16 nm for the NaHA concentration of 2 mg mL(-1) and 12 nm for the concentration of 3.5 mg mL(-1), in agreement with the calculated correlation lengths of the polymeric network. Since no experimental evidence exists for the presence of a stable network in the bulk, this tendency for self-association should be the result of the liquid confinement. To our knowledge, the existence of oscillatory disjoining pressure isotherms in the presence of excess salt was never observed for other polyelectrolyte solutions.

  18. Visco-Elastic Properties of Sodium Hyaluronate Solutions

    Science.gov (United States)

    Kulicke, Werner-Michael; Meyer, Fabian; Bingöl, Ali Ö.; Lohmann, Derek

    2008-07-01

    Sodium Hyaluronate (NaHA) is a member of the glycosaminoglycans and is present in the human organism as part of the synovial fluid and the vitreous body. HA is mainly commercialized as sodium or potassium salt. It can be extracted from cockscombs or can be produced by bacterial fermentation ensuring a low protein content. Because of its natural origin and toxicological harmlessness, NaHA is used to a great extent for pharmaceutical and cosmetic products. In medical applications, NaHA is already being used as a component of flushing and stabilizing fluids in the treatment of eye cataract and as a surrogate for natural synovial fluid. Another growing domain in the commercial utilization of NaHA is the field of skin care products like dermal fillers or moisturizers. In this spectrum, NaHA is used in dilute over semidilute up to concentrated (0solutions. In order to optimize NaHA samples for their specific utilization and to find new applications, it is of great interest to understand its viscoelastic behavior. We therefore present in this contribution the results of a comprehensive investigation of the viscous and elastic material functions of different NaHA samples. This includes, besides shear flow and oscillatory experiments, the performance of rheo-optical measurements in order to determine the elastic component in the range of low shear rates and low concentrations.

  19. Solution interactions of diclofenac sodium and meclofenamic acid sodium with hydroxypropyl methylcellulose (HPMC).

    Science.gov (United States)

    Pygall, Samuel R; Griffiths, Peter C; Wolf, Bettina; Timmins, Peter; Melia, Colin D

    2011-02-28

    Many pharmaceutical agents require formulation in order to facilitate their efficacious delivery. However, the interaction between the active species and the formulation additives has the potential to significantly influence the pharmocokinetics of the active. In this study, the solution interactions between hydroxypropyl methylcellulose (HPMC) with two non-steroidal anti-inflammatories - the sodium salts of diclofenac and meclofenamate - were investigated using tensiometric, rheological, NMR, neutron scattering and turbidimetric techniques. The two drugs behaved very differently-meclofenamate addition to HPMC solutions led to substantial increases in viscosity, a depression of the gel point and a marked reduction in the self-diffusion coefficient of the drug, whereas diclofenac did not induce these changes. Collectively, these observations are evidence of meclofenamate forming self-assembled aggregates on the HPMC, a phenomenon not observed with diclofenac Na. Any process that leads to aggregation on a nonionic polymer will not be strongly favoured when the aggregating species is charged. Thus, it is hypothesised that the distinction between the two drugs arises as a consequence of the tautomerism present in meclofenamate that builds electron density on the carbonyl group that is further stabilised by hydrogen bonding to the HPMC. This mechanism is absent in the diclofenac case and thus no interaction is observed. These studies propose for the first time a molecular basis for the observed often-unexpected, concentration-dependant changes in HPMC solution properties when co-formulated with different NSAIDs, and underline the importance of characterising such fundamental interactions that have the potential to influence drug release in solid HPMC-based dosage forms. Copyright © 2010 Elsevier B.V. All rights reserved.

  20. Sodium silicate solutions from dissolution of glasswastes. Statistical analysis

    Directory of Open Access Journals (Sweden)

    Torres-Carrasco, M.

    2014-05-01

    Full Text Available It has studied the solubility process of four different waste glasses (with different particle sizes, 125 µm in alkaline solutions (NaOH and NaOH/Na₂CO₃ and water as a reference and under different conditions of solubility (at room temperature, at 80°C and a mechano-chemical process. Have established the optimal conditions of solubility and generation of sodium silicates solutions, and these were: the smaller particle size (Se ha estudiado el proceso de solubilidad de cuatro diferentes residuos vítreos (con distintas granulometrías, 125 µm en disoluciones alcalinas de NaOH y NaOH/Na₂CO₃ y agua como medio de referencia y bajo distintas condiciones de solubilidad (a temperatura ambiente, a 80°C y con un proceso mecano-químico. Se han establecido las condiciones óptimas de solubilidad y generación de disoluciones de silicato sódico, y estas son: menor tamaño de partícula del residuo vítreo (inferior a 45 µm, con la disolución de NaOH/Na₂CO₃ y tratamiento térmico a 80°C durante 6 horas de agitación. El análisis estadístico realizado a los resultados obtenidos da importancia a las variables estudiadas y a las interacciones de las mismas. A través de ²⁹Si RMN MAS se ha confirmado la formación, tras los procesos de disolución, de un silicato monomérico, apto para su utilización como activador en la preparación de cementos y hormigones alcalinos.

  1. Uptake of ozone to mixed sodium bromide/ citric acid solutions

    Science.gov (United States)

    Lee, Ming-Tao; Steimle, Emilie; Bartels-Rausch, Thorsten; Kato, Shunsuke; Lampimäki, Markus; Brown, Matthew; van Bokhoven, Jeroen; Nolting, Frithjof; Kleibert, Armin; Türler, Andreas; Ammann, Markus

    2013-04-01

    Sea-salt solution - air interfaces play an important role in the chemistry of the marine boundary layer. The reaction of ozone (O3) with bromide is of interest in the context of formation of photolabile halogens (Br2, BrCl) in the marine boundary layer. Recent experiments have suggested that the bromide oxidation rate is related to the surface concentration of bromide [1] and inversely related to the gas phase concentration of O3, an indication for a precursor mediated reaction at the surface [2]. So far, the effect of organics (such as those occurring at the ocean surface or in marine aerosols) on the reaction of O3 with bromide aerosols has not been studied yet. In our study we investigate the uptake kinetics of O3 to a mixed solution of sodium bromide (NaBr) and citric acid (CA), which represents highly oxidized organic compounds present in the environment, with a well-established coated wall flow tube technique, which leads to exposure of the film to O3 allowing the heterogeneous reactions to take place and the loss of O3 being measured. The results indicate that the uptake of O3 to the films with the higher bromide concentrations (0.34M and 4M) is independent of the gas phase concentration and roughly consistent with uptake limited by reaction in the bulk. For the lower bromide concentration (84mM), however, we observe a trend of the uptake coefficient to decrease with increasing O3 concentration, indicating an increasing importance of a surface reaction. In an attempt to constrain the kinetic data, we employed X-ray photoelectron spectroscopy (XPS) to get insight into the surface composition of the aqueous solution - air interface. Previous XPS studies have shown that halide ion concentrations are enhanced at the aqueous solution air interface [3-4], which likely promotes the surface reactions of bromide or iodide with O3. A first XPS study of ternary solutions of KI with butanol indicated the importance of specific interactions of the cation with the alcohol

  2. The effectiveness of sodium hydroxide (NaOH) and sodium carbonate (Na2CO3) on the impurities removal of saturated salt solution

    Science.gov (United States)

    Pujiastuti, C.; Ngatilah, Y.; Sumada, K.; Muljani, S.

    2018-01-01

    Increasing the quality of salt can be done through various methods such as washing (hydro-extraction), re-crystallization, ion exchange methods and others. In the process of salt quality improvement by re-crystallization method where salt product diluted with water to form saturated solution and re-crystallized through heating process. The quality of the salt produced is influenced by the quality of the dissolved salt and the crystallization mechanism applied. In this research is proposed a concept that before the saturated salt solution is recrystallized added a chemical for removal of the impurities such as magnesium ion (Mg), calcium (Ca), potassium (K) and sulfate (SO4) is contained in a saturated salt solution. The chemical reagents that used are sodium hydroxide (NaOH) 2 N and sodium carbonate (Na2CO3) 2 N. This research aims to study effectiveness of sodium hydroxide and sodium carbonate on the impurities removal of magnesium (Mg), calcium (Ca), potassium (K) and sulfate (SO4). The results showed that the addition of sodium hydroxide solution can be decreased the impurity ions of magnesium (Mg) 95.2%, calcium ion (Ca) 45%, while the addition of sodium carbonate solution can decreased magnesium ion (Mg) 66.67% and calcium ion (Ca) 77.5%, but both types of materials are not degradable sulfate ions (SO4). The sodium hydroxide solution more effective to decrease magnesium ion than sodium carbonate solution, and the sodium carbonate solution more effective to decrease calcium ion than sodium hydroxide solution.

  3. Actinide-Aluminate Speciation in Alkaline Radioactive Waste

    Energy Technology Data Exchange (ETDEWEB)

    Dr. David L. Clark; Dr. Alexander M. Fedosseev

    2001-12-21

    Investigation of behavior of actinides in alkaline media containing AL(III) showed that no aluminate complexes of actinides in oxidation states (IIII-VIII) were formed in alkaline solutions. At alkaline precipitation IPH (10-14) of actinides in presence of AL(III) formation of aluminate compounds is not observed. However, in precipitates contained actinides (IIV)<(VI), and to a lesser degree actinides (III), some interference of components takes place that is reflected in change of solid phase properties in comparison with pure components or their mechanical mixture. The interference decreases with rise of precipitation PH and at PH 14 is exhibited very feebly. In the case of NP(VII) the individual compound with AL(III) is obtained, however it is not aluminate of neptunium(VII), but neptunate of aluminium(III) similar to neptunates of other metals obtained earlier.

  4. IMPACT OF INCREASED ALUMINATE CONCENTRATIONS ON PROPERTIES OF SALTSTONE MIXES

    International Nuclear Information System (INIS)

    Harbour, J; Tommy Edwards, T; Erich Hansen, E; Vickie Williams, V

    2007-01-01

    One of the goals of the Saltstone variability study is to identify the operational and compositional variables that control or influence the important processing and performance properties of Saltstone mixes. The protocols developed in this variability study are ideally suited as a tool to assess the impact of proposed changes to the processing flow sheet for Liquid Waste Operations (LWO). One such proposal that is currently under consideration is to introduce a leaching step in the treatment of the High Level Waste (HLW) sludge to remove aluminum prior to vitrification at the Defense Waste Processing Facility (DWPF). This leachate would significantly increase the soluble aluminate concentrations as well as the free hydroxide ion concentration in the salt feed that will be processed at the Saltstone Processing Facility (SPF). Consequently, an initial study of the impact of increased aluminate concentration on the Saltstone grout properties was performed. The projected compositions and ranges of the aluminate rich salt stream (which includes the blending strategy) are not yet available and consequently, in this initial report, two separate salt stream compositions were investigated. The first stream starts with the previously projected baseline composition of the salt solution that will be fed to SPF from the Salt Waste Processing Facility (SWPF). The second stream is the solution that results from washing of the current Tank 51 sludge and subsequent transfer of the salt solution to Tank 11. The SWPF simulant has higher nitrate and lower free hydroxide than the Tank 11 simulant. In both of these cases, the aluminate was varied up to a maximum of 0.40 to 0.45M aluminate in order to evaluate the impact of increasing aluminate ion concentration on the grout properties. In general, the fresh grout properties of mixes made with SWPF and Tank 11 simulants were relatively insensitive to an increase in aluminate concentration in the salt solutions. However, the overall

  5. 21 CFR 520.563 - Diatrizoate meglumine and diatrizoate sodium oral solution.

    Science.gov (United States)

    2010-04-01

    ... solution. 520.563 Section 520.563 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... § 520.563 Diatrizoate meglumine and diatrizoate sodium oral solution. (a) Specifications. Diatrizoate meglumine oral solution is a water soluble radiopaque medium containing 66 percent diatrizoate meglumine and...

  6. Factors Affecting Dissolution Resistance of AC Anodizing Al in Sodium Carbonate Solution

    International Nuclear Information System (INIS)

    Abou-Krisha, M.

    2001-01-01

    Studies were performed to determine the effect of different factors on the properties and so the dissolution resistance of the anodic film of Al. Conductance and thermometric measurements were applied to evaluate the dissolution rate. The effect of applied AC voltage concentration of sodium carbonate solution, the anodization time and the temperature of sodium carbonate solutions show a parallel increase in the dissolution resistance of studied Al in hydrochloride acid. The results show that films formed by sodium carbonate solution were of porous type and have pronounced high resistance. Scanning electron microscope and x-ray diffraction further examined the films. The anodic and cathodic behavior and the effect of the scanning rate on the polarization of Al in sodium carbonate solution were studied. The regression analysis was applied to all results. (Author)

  7. Theoretical and practical aspects of aqueous solution sodium silicate modifying

    Directory of Open Access Journals (Sweden)

    Mizuryaev Sergey

    2016-01-01

    Full Text Available This research deals with the use of liquid glass in industry particularly for porous filler production. The aim of this paper is to show the necessity liquid glass modification for the purpose of its rheological characteristics change for raw granules formation and providing given structure after porization. Data on chemical liquid glass modification are provided by adding sodium chloride. Moreover, inert mineral additives influence on porous filler properties are shown in this paper. The basic principles of light concrete composition selection are specified. Test results of light concrete on the developed porous sodium silicate filler are given.

  8. Supersolubility and induction of aluminosilicate nucleation from clear solution

    Science.gov (United States)

    Zhang, Yifei; Li, Yinghui; Zhang, Yi

    2003-06-01

    The supersolubility of silica in supersaturated aluminate solution and the sodium aluminosilicate precipitation nucleation mechanism from the clear solution were investigated by experiment. The obtained semi-empirical expression of the induction ( tind) of sodium aluminosilicate precipitation from clear solution is significant for zeolite A membranes synthesis, desilication and more important for valuating the stability of the supersaturated SiO 2 in the aluminate solution during the hydrolysis operation in the most used alkaline alumina manufacture. The semi-empirical expressions of the silica supersolubility in clear supersaturated sodium aluminate solution for both homogeneous and heterogeneous nucleation were originally conducted. The homogeneous nucleation predominated with the supersaturation ( S) above 6.0, conversely, heterogeneous nucleation with S below 4.0. The inferred activation energy ( Ea) of the homogeneous nucleated reaction was 14.9 kJ/mol, and that of the heterogeneous 50.5 kJ/mol. The interfacial tension ( γs) between the precipitate of sodium aluminosilicate and the surrounding aqueous solution was obtained at 15.1 mJ/m 2, negligibly decreased with increasing temperature. It was much larger than the value of 12.4 mJ/m 2 in pure water (J. Phys. Chem. B 105 (2001) 5383), but very much smaller than the estimated value of 38.64-50 mJ/m 2 in the solution for traditional zeolite synthesis.

  9. Bioequivalence of diclofenac sodium 2% and 1.5% topical solutions relative to oral diclofenac sodium in healthy volunteers.

    Science.gov (United States)

    Holt, Robert J; Taiwo, Tolu; Kent, Jeffrey D

    2015-08-01

    Topical formulations of nonsteroidal anti-inflammatory drugs (NSAIDs) are generally considered to be safer alternatives to oral NSAIDs due to lower systemic absorption. We conducted randomized, crossover studies that compared the pharmacokinetics (PK), bioequivalence and safety of topical diclofenac sodium 2% twice daily (BID), diclofenac sodium 1.5% four times daily (QID) and oral diclofenac sodium in healthy subjects. The results of three bioequivalence studies are reviewed. Healthy adult subjects (n = 76) applied topical diclofenac sodium 2% solution (40.4 mg/2 mL) BID; or 1.5% solution (19.3 mg/40 drops) QID to each knee for 7.5 consecutive days separated by a washout period. Subjects (n = 22) in one study also received oral diclofenac sodium 75 mg BID for 7.5 days. Plasma diclofenac concentrations were determined from serial blood samples collected on Days 1 and 8 (steady state), and diclofenac PK parameters were estimated by noncompartmental methods. The studies demonstrated comparable bioequivalence between the 2% and 1.5% topical solutions as well as lower systemic exposure compared to oral dosing (approximately 93% less). Daily systemic exposure was comparable between the two formulations with only a 12% difference in the AUCss(0-24) (p = 0.140). Furthermore, both topical solutions demonstrated delayed elimination with a t(1/2) of 4- to 6-fold longer, as compared to oral diclofenac. The 2% solution provided more consistent dosing relative to the 1.5% solution when comparing AUCss(0-24) and Cmaxss across studies. Mild application site reactions were the most common treatment-emergent adverse event reported with topical diclofenac. The steady-state PK profile of topical diclofenac 2% solution administered BID is similar to that of the 1.5% solution administered QID. Systemic exposure to diclofenac is substantially lower after topical application as compared to oral administration. (Study 2 was registered with ClinicalTrials.gov; NCT01202799; https

  10. Sodium thiosulfate solution spray for relief of irritation caused by Lugol's stain in chromoendoscopy.

    Science.gov (United States)

    Kondo, H; Fukuda, H; Ono, H; Gotoda, T; Saito, D; Takahiro, K; Shirao, K; Yamaguchi, H; Yoshida, S

    2001-02-01

    Mucosal iodine staining is known to improve the endoscopic visualization of esophageal squamous dysplasia and cancer. However, it often causes mucosal irritation leading to retrosternal discomfort. The clinical usefulness of sodium thiosulfate solution (STS) for easing symptoms induced by mucosal staining with Lugol's solution was evaluated in this study. One hundred twenty healthy men over 50 years of age were enrolled in the study. They each underwent esophagogastroscopy including the spraying of Lugol's iodine solution (10 mL) on the mid and distal esophagus and were subsequently randomized into three groups: (I) no treatment (n = 40), (II) spraying of 20 mL of aluminum-magnesium hydroxide gel (Maalox) by means of endoscopic catheter (n = 40), and (III) spraying of 20 mL of 5% sodium thiosulfate solution by means of endoscopic catheter (n = 40). An hour after the endoscopic examination the subjects were asked to complete a questionnaire that addressed adverse symptoms induced by Lugol's iodine staining. Sodium thiosulfate solution spray substantially reduced adverse symptoms that lasted more than 30 minutes after chromoendoscopy, compared with the no-treatment group. There was no significant difference in the proportion of subjects with symptoms between the Maalox and no-treatment groups. Cost of sodium thiosulfate solution spray per use was $0.15 (15 yen). Sodium thiosulfate solution is recommended for routine use after Lugol's staining.

  11. Oral sodium phosphate solution: a review of its use as a colorectal cleanser.

    Science.gov (United States)

    Curran, Monique P; Plosker, Greg L

    2004-01-01

    Oral sodium phosphate solution (Fleet Phospho-soda, Casen-Fleet Fosfosoda is a low-volume, hyperosmotic agent used as part of a colorectal-cleansing preparation for surgery, x-ray or endoscopic examination. The efficacy and tolerability of oral sodium phosphate solution was generally similar to, or significantly better than, that of polyethylene glycol (PEG) or other colorectal cleansing regimens in patients preparing for colonoscopy, colorectal surgery or other colorectal-related procedures. Generally, oral sodium phosphate solution was significantly more acceptable to patients than PEG or other regimens. The use of this solution should be considered in most patients (with the exception of those with contraindications) requiring colorectal cleansing. PHARMACOLOGICAL PROPERTIES: After the first and second 45 mL dose of oral sodium phosphate solution, the mean time to onset of bowel activity was 1.7 and 0.7 hours and the mean duration of activity was 4.6 and 2.9 hours. Bowel activity ceased within 4 hours of administration of the second dose in 83% of patients. Elevations in serum phosphorus and falls in serum total and ionised calcium from baseline occurred during the 24 hours after administration of oral sodium phosphate solution in seven healthy volunteers. These changes were not associated with significant changes in clinical assessments. The decrease in serum potassium levels after administration of oral sodium phosphate solution was negatively correlated with baseline intracellular potassium levels. A regimen that administered the first dose of sodium phosphate on the previous evening and a second dose on the morning of the procedure (10-12 hours apart) was significantly more effective than PEG-based regimens for colorectal cleansing in preparation for colonoscopy, sigmoidoscopy or colorectal surgery. A regimen that administered both doses of oral sodium phosphate on the day prior to the procedure offered no colorectal cleansing advantage over PEG

  12. Radiation protection by ascorbic acid in sodium alginate solutions

    International Nuclear Information System (INIS)

    Aliste, A.J.; Mastro, N.L. Del

    2004-01-01

    Alginates are gelling hydrocolloids extracted from brown seaweed used widely in the nourishing and pharmaceutical industries. As alginic acid gellification retard food entrance in the stomach alginate is an additive used in diets. The objective of this work was to study the protective action of the ascorbic acid in alginate solutions against the action of 60 Co gamma radiation. One % (w/v) solutions of alginate had been used and concentrations of ascorbic acid varied from 0 to 2.5% (w/v). The solutions were irradiated with doses up to 10 kGy. Viscosity/dose relationship and the p H of the solutions at 25 Centigrade were determined. Ascorbic acid behaved as an antioxidant against radiation oxidative shock in this model system of an irradiated viscous solution. Besides its radiation protective role on alginate solutions ascorbic acid promoted a viscosity increase in the range of concentrations employed. (Author)

  13. Radiation protection by ascorbic acid in sodium alginate solutions

    Energy Technology Data Exchange (ETDEWEB)

    Aliste, A.J.; Mastro, N.L. Del [Center of Radiation Technology, IPEN/CNEN/SP, University City, 05508-000 Sao Paulo (Brazil)]. E-mail: ajaliste@ipen.br

    2004-07-01

    Alginates are gelling hydrocolloids extracted from brown seaweed used widely in the nourishing and pharmaceutical industries. As alginic acid gellification retard food entrance in the stomach alginate is an additive used in diets. The objective of this work was to study the protective action of the ascorbic acid in alginate solutions against the action of {sup 60} Co gamma radiation. One % (w/v) solutions of alginate had been used and concentrations of ascorbic acid varied from 0 to 2.5% (w/v). The solutions were irradiated with doses up to 10 kGy. Viscosity/dose relationship and the p H of the solutions at 25 Centigrade were determined. Ascorbic acid behaved as an antioxidant against radiation oxidative shock in this model system of an irradiated viscous solution. Besides its radiation protective role on alginate solutions ascorbic acid promoted a viscosity increase in the range of concentrations employed. (Author)

  14. 21 CFR 173.325 - Acidified sodium chlorite solutions.

    Science.gov (United States)

    2010-04-01

    ... agent in poultry processing water in accordance with current industry practice under the following... a post-chill carcass spray or dip solution when applied to poultry meat, organs, or related parts or... carcass; (iii) As a component of a spray or dip solution for application to poultry carcass parts; (iv) In...

  15. Stabilization of solutions of feather keratins by sodium dodecyl sulphate

    NARCIS (Netherlands)

    Schrooyen, P.M.M.; Dijkstra, Pieter J.; Oberthür, Radulf C.; Bantjes, A.; Bantjes, Adriaan; Feijen, Jan

    2001-01-01

    Feather keratins were extracted from chicken feathers with aqueous solutions of urea and 2-mercaptoethanol. After filtration of the insoluble residue, a feather keratin solution was obtained. Removal of 2-mercaptoethanol and urea by dialysis resulted in aggregation of the keratin polypeptide chains

  16. Sodium

    Science.gov (United States)

    Table salt is a combination of two minerals - sodium and chloride Your body needs some sodium to work properly. It helps with the function ... in your body. Your kidneys control how much sodium is in your body. If you have too ...

  17. Production of zeolite A come from rio Capim Kaolin: Study on recycle of sodium hydroxide solution

    International Nuclear Information System (INIS)

    Moraes, C.G.; Rodrigues, E.C.; Rocha Junior, C.A.F.; Macedo, E.N.; Neves, R.F.

    2011-01-01

    The kaolin processing industry is an important economic sector in the State of Para, but produces huge amounts of wastes composed essentially of kaolinite. The production processes of zeolites typically use sodium hydroxide in excess, are discarded. So the objective is the development process for production of zeolite A which allows the reuse of the solution of sodium hydroxide used in excess through your recycling. Presents the results of XRD, SEM of the zeolites produced in five consecutive cycles performed at a temperature of 110°C/24h as a source of sodium hydroxide solution of sodium 5 M, using a molar ratio of Si/Al = 1 and Na/Al = 1,26. (author)

  18. Study on the utilization of a sodium-sulfuric acid solution for the uranium minerals' leaching

    International Nuclear Information System (INIS)

    Echenique, Patricia; Fruchtenicht, Fernando; Gil, Daniel; Vigo, Daniel; Bouza, Angel; Vert, Gabriela; Becquart, Elena

    1988-01-01

    Argentine uranium minerals have been leached at bench scale with a different agent trying to reduce sulfuric acid consumption. The leaching agent was a sodium sulfate-sulfuric acid solution and the ore was from Sierra Pintada (San Rafael - Mendoza). The work was performed in stirred vessel at atmospheric pressure. The influence of different variables, pH, temperature, oxidant agent, sodium sulfate concentration and time, in the sulfuric acid consumption and the uranium yield was studied. (Author) [es

  19. Effective extractants for the extraction of lithium from aqueous solutions containing sodium and potassium compounds

    International Nuclear Information System (INIS)

    Marinkina, G.A.; Zanina, A.S.; Shergina, S.I.; Sokolov, I.E.; Kotlyarevskii, I.L.

    1992-01-01

    The extraction power of newly obtained pure methoxy-1,3-diketones in diluents and in their mixtures with electron-donating additives during the extraction of lithium from aqueous solutions containing sodium and potassium was investigated. High separation factors were obtained; no appreciable amounts of sodium and potassium were found in the extract after total extraction of the lithium. 9 refs., 2 figs., 8 tabs

  20. Method of processing aluminous ores

    Science.gov (United States)

    Loutfy, Raouf O.; Keller, Rudolf; Yao, Neng-Ping

    1981-01-01

    A method of producing aluminum chloride from aluminous materials containing compounds of iron, titanium and silicon comprising reacting the aluminous materials with carbon and a chlorine-containing gas at a temperature of about 900.degree. K. to form a gaseous mixture containing chlorides of aluminum, iron, titanium and silicon and oxides of carbon; cooling the gaseous mixture to a temperature of about 400.degree. K. or lower to condense the aluminum chlorides and iron chlorides while titanium chloride and silicon chloride remain in the gas phase to effect a separation thereof; heating the mixture of iron chlorides and aluminum chlorides to a temperature of about 800.degree. K. to form gaseous aluminum chlorides and iron chlorides; passing the heated gases into intimate contact with aluminum sulfide to precipitate solid iron sulfide and to form additional gaseous aluminum chlorides; and separating the gaseous aluminum chloride from the solid iron sulfide.

  1. Lithium aluminates and tritium production

    International Nuclear Information System (INIS)

    Carrera G, L.M.; Palacios G, O.; Bosch G, P.

    1997-01-01

    In this work it is studied the crystalline structure of lithium aluminates prepared by three different methods, namely: solid state reaction, humid reaction and sol-gel reaction. The analysis methods are the X-ray diffractometry and the scanning and transmission electron microscopy. This study is realized as in original materials as in irradiated materials at the TRIGA Mark reactor, to correlate the synthesis method with response of these materials to the mixed irradiation of nuclear reactor. (Author)

  2. Optimization of a Strontium Aluminate

    Energy Technology Data Exchange (ETDEWEB)

    Bone, Alexandria N. [Maryville College, TN (United States)

    2017-08-01

    Strontium aluminate with Eu2+ and Dy3+ has been at the forefront of emerging applications for storage phosphors since its discovery in 1996. In this study, the emission intensity and luminescence lifetime of SrAl2O4: Eu2+, Dy3+ were enhanced by partial substitution of Ca2+ into Sr2+ sites in the matrix.

  3. Suppressive effects of a polymer sodium silicate solution on ...

    African Journals Online (AJOL)

    Mohsen

    2015-10-21

    Oct 21, 2015 ... content does not affect the incidence of powdery mildew. Root rot disease. Effect of each silicate solution on the root rot of miniature rose. The disease incidence of root rot on the aboveground parts and roots of miniature rose was examined. For the aboveground parts, the disease incidence of the pathogen ...

  4. The influence of low oxygen and contaminated sodium environments on the fatigue behavior of solution treated AISI 316 stainless steel

    International Nuclear Information System (INIS)

    Marshall, P.

    1977-01-01

    The influence of air and sodium environments on the fatigue properties of solution treated AISI 316 steel was studied by predictive methods and by conducting tests in air, in high temperature sodium, or following pre-exposure to sodium. The sodium environments studied included contaminated sodium or the products of sodium/water flames possibly typical of fast reactor fault conditions, and low oxygen sodium more appropriate to normal plant operation. Generally, fatigue properties were reduced by contaminated sodium or the products of sodium/water flames and improved by low oxygen sodium when compared with similar tests conducted in air. However, complex effects were observed with respect to crack initiation. The experimental results are discussed and generally follow trends predicted by physically based fatigue models. (author)

  5. On the influence of molecular structure on the conductivity of electrolyte solutions - sodium nitrate in water

    Directory of Open Access Journals (Sweden)

    H. Krienke

    2013-01-01

    Full Text Available Theoretical calculations of the conductivity of sodium nitrate in water are presented and compared with experimental measurements. The method of direct correlation force in the framework of the interionic theory is used for the calculation of transport properties in connection with the associative mean spherical approximation (AMSA. The effective interactions between ions in solutions are derived with the help of Monte Carlo and Molecular Dynamics calculations on the Born-Oppenheimer level. This work is based on earlier theoretical and experimental studies of the structure of concentrated aqueous sodium nitrate solutions.

  6. [Study on the Influence of Mineralizer on the Preparation of Calcium Aluminates Based on Infrared Spectroscopy].

    Science.gov (United States)

    Fan, Wei; Wang, Liang; Zheng, Huai-li; Chen, Wei; Tang, Xiao-min; Shang, Juan-fang; Qian, Li

    2015-05-01

    In this study, effect of mineralizer on the structure and spectraproperties of calcium aluminates formation was extensively studied. Medium or low-grade bauxite and calcium carbonate were used as raw material and mineralizer CaF2 as additive. Calcium aluminates can be obtained after mixing fully, calcination and grinding. The prepared calcium aluminates can be directly used for the production of polyaluminiumchloride (PAC), polymeric aluminum sulfate, sodium aluminate and some other water treatment agents. The calcium aluminates preparation technology was optimized by investigating the mass ratio of raw materials (bauxiteand calcium carbonate) and mineralizer CaF2 dosage. The structure and spectra properties of bauxite and calcium aluminates were characterized by Fourier transform infrared(FTIR) spectroscopy analysis and the mineralization mechanism of the mineralizer was studied. FTIR spectra indicated that the addition of mineralizer promoted the decomposition and transformation of the diaspore, gibbsite and kaolinite, the decomposition of calcium carbonate, and more adequately reaction between bauxite and calcium carbonate. In addition, not only Ca in calcium carbonate and Si in bauxite were more readily reacted, but also Si-O, Si-O-Al and Al-Si bonds in the bauxite were more fractured which contributed to the release of Al in bauxite, and therefore, the dissolution rate of Al2O3 could be improved. The dissolution rate of Al2O3 can be promoted effectively when the mineralizer CaF2 was added in a mass ratio amount of 3%. And the mineralizer CaF2 cannot be fully functioned, when its dosage was in a mass percent of 1. 5%. Low-grade bauxite was easier to sinter for the preparation of calcium aluminates comparing with the highgrade one. The optimum material ratio for the preparation of calcium aluminates calcium at 1 250 °C was the mass ratio between bauxite and calcium carbonate of 1 : 0. 6 and mineralizer CaF2 mass ratio percent of 3%.

  7. Antimicrobial action of sodium hypochlorite and castor oil solutions for denture cleaning - in vitro evaluation.

    Science.gov (United States)

    Salles, Marcela Moreira; Oliveira, Viviane de Cássia; Souza, Raphael Freitas; Silva, Cláudia Helena Lovato; Paranhos, Helena de Freitas Oliveira

    2015-01-01

    The objective of this in vitro study was to evaluate the antimicrobial action of sodium hypochlorite (0.25% and 0.50%) and 10% castor oil solutions against specific microorganisms, by counting Colony Forming Units (CFU) of clinically important bacteria and Candida species. Acrylic resin specimens (n = 320; Lucitone 550) were obtained from square metal matrices (10 x 10 x 2 mm), sterilized by microwave (650W, for 6 minutes) and contaminated by Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, Bacillus subtilis, Escherichia coli, Streptococcus mutans, Enterococcus faecalis and Candida glabrata. The specimens were immersed for 20 minutes in one of the following hygiene solutions (n = 10/each): A - 0.25% Sodium hypochlorite; B - 0.5% Sodium hypochlorite; C - 10% Castor oil solution; and D (Control) - saline. Adhered cells were suspended and inoculated into a selective solid medium (37ºC for 24 h). The Student's t-test (α = 0.05) was performed to compare log10(CFU+1)/mL between Groups C and D. The results showed that sodium hypochlorite (0.25% and 0.5%) completely eliminated all detectable microorganisms. The castor oil solution eliminated B. subtilis and reduced counts for other strains. Differences between C and D were significant (p castor oil solution provided moderate efficacy and performed differently on the tested species, with the strongest effect on B. subtilis and with non-significant action on E. faecalis.

  8. Antimicrobial action of sodium hypochlorite and castor oil solutions for denture cleaning – in vitro evaluation

    Directory of Open Access Journals (Sweden)

    Marcela Moreira SALLES

    2015-01-01

    Full Text Available The objective of this in vitro study was to evaluate the antimicrobial action of sodium hypochlorite (0.25% and 0.50% and 10% castor oil solutions against specific microorganisms, by counting Colony Forming Units (CFU of clinically important bacteria and Candida species. Acrylic resin specimens (n = 320; Lucitone 550 were obtained from square metal matrices (10 x 10 x 2 mm, sterilized by microwave (650W, for 6 minutes and contaminated by Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, Bacillus subtilis, Escherichia coli, Streptococcus mutans, Enterococcus faecalisand Candida glabrata. The specimens were immersed for 20 minutes in one of the following hygiene solutions (n = 10/each: A – 0.25% Sodium hypochlorite; B – 0.5% Sodium hypochlorite; C – 10% Castor oil solution; and D (Control – saline. Adhered cells were suspended and inoculated into a selective solid medium (37ºC for 24 h. The Student’s t-test (α = 0.05 was performed to compare log10(CFU+1/mL between Groups C and D. The results showed that sodium hypochlorite (0.25% and 0.5% completely eliminated all detectable microorganisms. The castor oil solution eliminatedB. subtilisand reduced counts for other strains. Differences between C and D were significant (p E. faecalis. Both sodium hypochlorite solutions (0.25% and 0.5% were effective in eliminating all microorganisms evaluated, and may be useful as cleaning solutions for complete dentures. The castor oil solution provided moderate efficacy and performed differently on the tested species, with the strongest effect on B. subtilis and with non-significant action on E. faecalis.

  9. Antiadhesive effect of mixed solution of sodium hyaluronate and sodium carboxymethylcellulose after blow-out fracture repair.

    Science.gov (United States)

    Lee, Jong Mi; Baek, Sehyun

    2012-11-01

    Treatment of blow-out fractures is aimed at the prevention of permanent diplopia and cosmetically unacceptable enophthalmos. Porous polyethylene sheets are one of the most common alloplastic implants for blow-out fracture repair. Because adhesion between the porous polyethylene and the orbital soft tissue can result in restrictions of ocular motility, prevention of postoperative adhesion is important in the reconstruction of blow-out fractures. The purpose of this study was to find out the effect of the mixed solution of sodium hyaluronate and sodium carboxymethylcellulose (HACMC) on postoperative adhesion in blow-out fracture repair in an animal model.Twenty-four New Zealand white rabbits were used. An 8-mm defect was made in the maxillary sinuses including the bone and mucosa. A 10-mm porous polyethylene sheet (Medpor; Porex Surgical Inc., Newnan, GA) was inserted in to the defect. The rabbits were divided into a control group and a HACMC group. In the HACMC group, HACMC solution was instilled onto the surface of the implant and then the implant was inserted. The implants were harvested at 1, 2, 4, and 8 weeks after surgery (3 implants each period). Hematoxylin and eosin, Masson trichrome, and CD31 (platelet endothelial cell adhesion molecule-1) stains were performed for evaluation of inflammation, fibrosis, and vascularization.Inflammation appeared less severe in the HACMC group, but the difference between the 2 groups was not statistically significant. The degree of fibrosis was more severe in the control group. There were significant differences in the degree of fibrosis between the 2 groups 4 and 8 weeks after surgery (P = 0.046). The amount of vascularization was similar in both groups.The HACMC solution seemed to be effective for reducing postoperative adhesion in reconstruction of blow-out fractures in a rabbit model. Our results suggest that the application of HACMC solution could be an effective adjunct for the repair of trap-door fractures or revision

  10. An empirical model to estimate density of sodium hydroxide solution: An activator of geopolymer concretes

    Science.gov (United States)

    Rajamane, N. P.; Nataraja, M. C.; Jeyalakshmi, R.; Nithiyanantham, S.

    2016-02-01

    Geopolymer concrete is zero-Portland cement concrete containing alumino-silicate based inorganic polymer as binder. The polymer is obtained by chemical activation of alumina and silica bearing materials, blast furnace slag by highly alkaline solutions such as hydroxide and silicates of alkali metals. Sodium hydroxide solutions of different concentrations are commonly used in making GPC mixes. Often, it is seen that sodium hydroxide solution of very high concentration is diluted with water to obtain SHS of desired concentration. While doing so it was observed that the solute particles of NaOH in SHS tend to occupy lower volumes as the degree of dilution increases. This aspect is discussed in this paper. The observed phenomenon needs to be understood while formulating the GPC mixes since this influences considerably the relationship between concentration and density of SHS. This paper suggests an empirical formula to relate density of SHS directly to concentration expressed by w/w.

  11. Effect of concentration and temperature on surface tension of sodium hyaluronate saline solutions.

    Science.gov (United States)

    Ribeiro, Walkiria; Mata, José Luis; Saramago, Benilde

    2007-06-19

    The effect of concentration and temperature on the surface tension of sodium hyaluronate (NaHA) saline solutions was investigated using the technique of the shape of pendant drops. The decay rate of the surface tension with the increase of NaHA concentration was well-described by the empirical Hua-Rosen equation. Adsorption at the air-liquid interface was estimated using the Gibbs equation. The temperature dependence of a dilute solution and a semidilute entangled solution was numerically fitted with a second-order polynomial equation. The surface behavior of the NaHA saline solutions was interpreted in terms of their known viscoelastic properties.

  12. The determination of hydroxide and carbonate in concentrated sodium chloride solutions

    NARCIS (Netherlands)

    Roolvink, W.B.; Bos, M.

    1980-01-01

    A computer method for the determination of carbonate and hydroxide in concentrated (2.89 M) sodium chloride solutions is described. The method is based on multiparametric curve-fitting and can also be applied to salts of dibasic acids with unknown equilibrium constants. The systematic error is not

  13. Solubility of hydrogen in aqueous solutions of sodium and potassium bicarbonate from 293 to 333 K

    NARCIS (Netherlands)

    Engel, D.C.; Engel, D.C.; Versteeg, Geert; van Swaaij, Willibrordus Petrus Maria

    1996-01-01

    An experimental study is presented of the hydrogen solubility in aqueous salt solutions containing sodium and potassium bicarbonate from 293 to 333 K. For this purpose, gas consumption measurements have been performed by determining the ultimate pressure decrease in an intensively stirred, high

  14. Solubility of Hydrogen in Aqueous Solutions of Sodium and Potassium Bicarbonate from 293 to 333 K

    NARCIS (Netherlands)

    Engel, Dico C.; Versteeg, Geert F.; Swaaij, Wim P.M. van

    1996-01-01

    An experimental study is presented of the hydrogen solubility in aqueous salt solutions containing sodium and potassium bicarbonate from 293 to 333 K. For this purpose, gas consumption measurements have been performed by determining the ultimate pressure decrease in an intensively stirred, high

  15. Concentration of rhenium from dilute sodium chloride solutions

    Directory of Open Access Journals (Sweden)

    DRAGOLJUB M. LUKIC

    2008-03-01

    Full Text Available The conditions for the desorption of rhenium from the anion exchange resin Dowex 1-x8 by HNO3, HCl, H2SO4 and NaOH were determined. The solution (5.0´10-3 mol dm-3 Re in 0.15 mol dm-3 NaCl was passed through a column containing 0.10 g of the resin. The total sorbed amount of rhenium was 0.20 g/g of the resin. It was then eluted by the corresponding eluent in the concentration range up to about 3.0 mol dm-3. The highest elution efficiency and the most favourable elution profile were found with 3.0 mol dm-3 HNO3. Over 77 % of the sorbed rhenium was found in the first 5 ml of the eluate. Practically all the rhenium was recovered with 20 ml of the acid. Under the given experimental conditions, HCl and H2SO4 were less favourable while NaOH was not applicable, due to very low efficiency of rhenium elution.

  16. Production of I-125 radioisotope in sodium iodide solution

    International Nuclear Information System (INIS)

    Nabardi, B.; Gourani, M.

    2004-01-01

    120 minutes at a temperature of 550 o C. Solutions of the required radioactive concentration are dispensed to portions into ampoules. If sterile product is required ampoules should be autoclaved for 30 minutes at a temperature of 120 o C. (author)

  17. Volumetric and conductometric studies on the interactions of dipeptides with sodium acetate and sodium butyrate in aqueous solutions at T = 298.15 K

    International Nuclear Information System (INIS)

    Yan Zhenning; Wang Xiaoge; Xing Ronghua; Wang Jianji

    2009-01-01

    Densities and conductivity data for the sodium carboxylate (sodium acetate and sodium butyrate)-dipeptides {(glycyl-L-glutamine and L-alanyl-L-glutamine) + water} systems were determined at T = 298.15 K. The apparent molar volumes of the peptides and the molar conductivity (Λ) of sodium acetate and sodium butyrate have been calculated. These data have been utilized to deduce the standard partial molar volumes (V 2,Φ 0 ), standard partial molar volumes of transfer for dipeptide from water to aqueous sodium carboxylate solutions (Δ t V o ), volumetric interaction coefficient, the limiting molar conductivity (Λ o ), and Walden product (Λ o η). Both V 2,Φ 0 and Δ t V o for the dipeptides increase with increasing concentration of sodium carboxylate. The interpretation is that this result arises from the dominant interactions of the sodium carboxylate with the charged group and polar groups of peptides. The decrease in Λ o of sodium carboxylate with increasing dipeptide concentration and nonconstant Walden product are attributed to the interactions of sodium carboxylate with peptide and friction resistance of the solvent medium.

  18. Cesium decontamination using a microbubble-treated aqueous solution of sodium metasilicate

    International Nuclear Information System (INIS)

    Ueda, Yoshikatsu; Tokuda, Yomei; Goto, Hiroshi

    2015-01-01

    The remediation of materials contaminated with radioactive materials, such as 137 Cs, is important. Here, we report the effectiveness of an aqueous Sodium Metasilicate prepared via a microbubble Crushing process (SMC) for the removal of radioactive 137 Cs from granule conglomerates and nonwoven cloth. A 137 Cs removal ratio of 78% was achieved for the nonwoven cloth sample, and multiple washings at low SMC concentrations were effective. In addition, the volume of the waste solution could be reduced by neutralizing the SMC and using gelation to remove the radioactive material. The decontamination achieved using this process was more efficient than that with sodium hydroxide, even for granule conglomerates. (author)

  19. Standardization of sodium metabisulfite solution concentrations and immersion time for farmed shrimp Litopenaeus vannamei

    Directory of Open Access Journals (Sweden)

    Luciana Trigueiro de Andrade

    2015-03-01

    Full Text Available Sodium metabisulfite is the main additive used in the prevention of melanosis in shrimp; however, it has currently been employed with great variation in concentration by producers. Thus, the aim of the present study was to determine the correlation between the concentration of the sodium metabisulfite solution and immersion time of the whole shrimp to obtain the concentration of sulfur dioxide (SO2 in the edible muscle of farmed shrimp (Litopenaeus vannamei in accordance with the limit established by law. For this, solutions of sodium metabisulfite at different concentrations (1%, 2 %, 3 %, 4% and 5% were prepared and samples of L. vannamei shrimp (100g were immersed during 10, 20 or 30 minutes at temperature of 7°C. For all treatment assayed the concentration of SO2 was determined in the edible muscle of farmed shrimp (L. vannamei. The results show that for the conditions used in this study, the correlations were linear, with significant increase (P<0.05 in the SO2 concentration in the edible muscle of shrimps both increasing sodium metabisulfite concentration as increasing immersion times, suggesting the immersion of shrimps in a 3% solution for a time of 13 minutes in order to obtain SO2 concentration of 100ppm in its edible muscle in accordance with Brazilian legislation

  20. Extended stability of intravenous 0.9% sodium chloride solution after prolonged heating or cooling.

    Science.gov (United States)

    Puertos, Enrique

    2014-03-01

    The primary objective of this study was to evaluate the stability and sterility of an intravenous 0.9% sodium chloride solution that had been cooled or heated for an extended period of time. Fifteen sterile 1 L bags of 0.9% sodium chloride solution were randomly selected for this experiment. Five bags were refrigerated at an average temperature of 5.2°C, 5 bags were heated at an average temperature of 39.2°C, and 5 bags were stored at an average room temperature of 21.8°C to serve as controls. All samples were protected from light and stored for a period of 199 days prior to being assayed and analyzed for microbial and fungal growth. There was no clinically significant difference in the mean sodium values between the refrigerated samples, the heated samples, and the control group. There were no signs of microbial or fungal growth for the duration of the study. A sterile intravenous solution of 0.9% sodium chloride that was heated or cooled remained stable and showed no signs of microbial or fungal growth for a period of 199 days. This finding will allow hospitals and emergency medical technicians to significantly extend the expiration date assigned to these fluids and therefore obviate the need to change out these fluids every 28 days as recommended by the manufacturer.

  1. Thermogravimetric analysis of phase transitions in cement compositions mixed by sodium silicate solution

    Directory of Open Access Journals (Sweden)

    Fedosov Sergey Viktorovich

    2014-01-01

    Full Text Available This paper presents a study of the capability to modify cement by mechanical activation of sodium silicate water solution. Admixtures or blends of binding agents were employed for modifying concrete properties. The liquid glass is applied to protect from chemically or physically unfavorable environmental impacts, such as acidic medium and high temperature. The sodium silicate is a high-capacity setting accelerator. The increasing of the liquid glass proportion in the mix leads to the degradation of the cement paste plasticity and for this reason it is necessary to reduce the amount of liquid glass in the cement paste. The activation of dilute water solution of sodium silicate into rotary pulsating apparatus directly before tempering of the cement paste is an effective way to decrease mass fraction of liquid glass in the cement paste. The results of the combined influence of liquid glass and mechanical activation on physicochemical processes taking place in cement stone are represented in this research. Thermogravimetric analysis was used in order to study cement blends. Thermogravimetric analysis of modified cement stone assays was performed by thermo analyzer SETARAM TGA 92-24. The results of the analysis of phase transition taking place under high-temperature heating of cement stone modified by the mechanical activation of the water solution of the sodium silicate were introduced. Thermograms of cement stone assays were obtained at different hardening age. The comparison of these thermograms allows us to come to a conclusion on the formation and the retention during long time of a more dense structure of the composite matrix mixed by the mechanical activation of sodium silicate water solution. The relation between the concrete composition and its strength properties was stated. Perhaps, the capability of modified concrete to keep calcium ions in sparingly soluble hydrosilicates leads to the increase in its durability and corrosion resistance.

  2. Preparation and application of potassium and sodium titanate for removal of plutonium from basic solution

    International Nuclear Information System (INIS)

    Patil, Prashant; Pathak, Sachin S.; Pius, I.C.; Mukerjee, S.K.

    2014-01-01

    In PUREX process, after extraction and stripping of uranium and plutonium, the extractant, tributyl phosphate is usually washed with sodium carbonate solution before reuse for the removal of radiolytic/hydrolytic degradation products of TBP and small amounts of HNO 3 , uranium and plutonium goes into aqueous phase during carbonate washings. Partial neutralization of carbonate by the acid converts it to bicarbonate. Removal of plutonium from such sodium carbonate/bicarbonate streams facilitates their disposal. In the present work, studies were carried out to prepare inorganic ion-exchangers such as potassium and sodium titanates for their application as ion-exchange material. It is essential to prepare these materials in granular form to obtain good liquid flow property for ion exchange column operations, however, it is also important that the final product is having good surface area and porosity so that they may exhibit good ion exchange capacity

  3. Evaluation of sodium lignin sulfonate as draw solute in forward osmosis for desert restoration

    KAUST Repository

    Duan, Jintang

    2014-03-01

    Sodium lignin sulfonate (NaLS), an abundant waste product of paper manufacturing, can be used in desert restoration. Combined with water and applied on arid land, NaLS has been shown to stabilize sand and provide a medium for plant growth. Here, we demonstrate that NaLS is an efficient draw solute in forward osmosis (FO) to extract water from impaired sources. The osmotic pressure of a 600. g. NaLS/kg water solution is 78. bar (7.8 MPa) as measured by freezing point depression. The FO performance using NaLS draw solute was evaluated with commercial FO membranes under various test conditions. The effects of draw solute concentration, feed salinity and membrane orientation were systematically investigated. Potential ways to optimize the process, e.g. combining fertilizer draw solutes and NaLS, are proposed. © 2013 Elsevier B.V.

  4. Analysis of the sodium recirculation theory of solute-coupled water transport in small intestine.

    Science.gov (United States)

    Larsen, Erik Hviid; Sørensen, Jakob Balslev; Sørensen, Jens Nørkaer

    2002-07-01

    Our previous mathematical model of solute-coupled water transport through the intestinal epithelium is extended for dealing with electrolytes rather than electroneutral solutes. A 3Na+-2K+ pump in the lateral membranes provides the energy-requiring step for driving transjunctional and translateral flows of water across the epithelium with recirculation of the diffusible ions maintained by a 1Na+-1K+-2Cl- cotransporter in the plasma membrane facing the serosal compartment. With intracellular non-diffusible anions and compliant plasma membranes, the model describes the dependence on membrane permeabilities and pump constants of fluxes of water and electrolytes, volumes and ion concentrations of cell and lateral intercellular space (lis), and membrane potentials and conductances. Simulating physiological bioelectrical features together with cellular and paracellular fluxes of the sodium ion, computations predict that the concentration differences between lis and bathing solutions are small for all three ions. Nevertheless, the diffusion fluxes of the ions out of lis significantly exceed their mass transports. It is concluded that isotonic transport requires recirculation of all three ions. The computed sodium recirculation flux that is required for isotonic transport corresponds to that estimated in experiments on toad small intestine. This result is shown to be robust and independent of whether the apical entrance mechanism for the sodium ion is a channel, a SGLT1 transporter driving inward uphill water flux, or an electroneutral Na+-K+-2Cl- cotransporter.

  5. Efficacy and tolerance of sodium phosphates oral solution after diet liberalization.

    Science.gov (United States)

    Scott, Sherrie R; Raymond, Patricia L; Thompson, William O; Galt, Deborah J B

    2005-01-01

    Bowel cleansing regimens commonly require adherence to liquid diets for 24 to 48 hours before examination, which often leads to poor compliance, reduced cleansing, and ultimately inadequate examinations. The authors investigated the efficacy and tolerability of diet liberalization before bowel cleansing with sodium phosphates oral solution. Two hundred patients were randomized into two treatment groups. One group received the standard light breakfast followed by clear liquids the day before colonoscopy; the second had a normal breakfast followed by a low-residue lunch the day before colonoscopy. Both groups had the same bowel preparation with sodium phosphates oral solution (2 x 45-mL, 7 p.m./6 a.m.). There was no difference in clinical efficacy between the two diet regimens (excellent/good in 93% standard, 95% low-residue). Fewer patients receiving the low-residue diet reported hunger, and more patients receiving the low-residue regimen reported energy to perform usual activities. This study supports offering patients a regular breakfast and a low-residue lunch before bowel cleansing with sodium phosphates oral solution.

  6. Corrosion Characterization Of ZA-27 Red Mud Metal Matrix Composites In Sodium Chloride Solutions

    Directory of Open Access Journals (Sweden)

    Jayaprakash

    2017-08-01

    Full Text Available The present investigation aims to evaluate the corrosion characteristics of red mud metal in sodium chloride solution. Metal matrix composites MMC are heterogeneous systems containing matrix and reinforcement. Matrix may be alloy or metal or polymer. Reinforcement may be particulate or fiber or whisker. Their physical and mechanical properties can be tailored according to requirement. They are used in automobile aircraft and marine industries because of their increased corrosion resistance. In this study weight loss corrosion tests and Potestiodynamic polarization studies by using potestiostat are conducted on ZA-27 Red Mud metal matrix composites in different concentrated sodium chloride solutions. Both matrix and reinforcements are commercially available. Composites are prepared by liquid melt metallurgy technique using vortex method. Composites containing 2 4 and 6 percent of preheated but uncoated red mud are prepared. Cylindrical specimens and rectangular specimens are machined. Studies are carried out in 0.035 0.352 and 3.5 solutions of sodium chloride. In all the tests the composites were less prone to corrosion than the matrix. Hence the composites can be used in the marine environment.

  7. Inactivation of Listeria monocytogenes ATCC 7644 on tomatoes using sodium docecyl sulphate, levulinic acid and sodium hypochlorite solution

    Directory of Open Access Journals (Sweden)

    E. Mnyandu

    2015-06-01

    Full Text Available The human pathogen Listeria monocytogenes poses a serious threat to public health. A study was carried out to evaluate the effectiveness of four sanitizers, used individually or combined, against L. monocytogenes ATCC 7644. The contact times for bacteria and sanitizer were varied to 1, 3 and 5 minutes. Levulinic acid, sodium dodecyl sulphate (SDS, sodium hypochlorite solution (chlorine and a combination of SDS and levulinic acid (mixture were tested. Results revealed that 0.5% levulinic acid, when used individually, is capable of reducing the surviving colonies by 3.63 log CFU/mL, 4.05 log CFU/mL, 6.71 log CFU/mL after exposure for 1, 3 and 5 minutes respectively.SDS resulted in an 8 log CFU/mL reduction after 1, 3 and 5 minutes. A combination of 0.5% levulinic acid and 0.05% SDS caused a 3.69 log CFU /mL reduction, 4.4 log CFU/mL reduction, 7.97 log CFU/mL reduction for 1, 3 and 5 minutes respectively. Chlorine was the least effective with 2.93 log CFU/mL reduction, 3.16 log CFU/ mL reduction and 4.53 log CFU/ mL reduction respectively. When stored for up to 72 hours at 4°C, the surviving colonies remained viable and decreased in number significantly P < 0.05 = 0.001. The titratable acidity of samples treated with levulinic acid and samples treated with SDS/Lev mixture was lowered significantly compared to the control sample. No significant differences were noted in these same parameters for samples treated with chlorine or SDS. The application of SDS in the fresh produce industry as a sanitizing agent may be successful in eradicating or reducing the viability of L. monocytogenes on fresh produce, thereby replacing the routine chlorine washing.

  8. The radiation chemistry of aqueous solutions of sodium 9,10-anthraquinone-2-sulfonate

    International Nuclear Information System (INIS)

    Burchill, C.E.; Smith, D.M.; Charlton, J.L.

    1976-01-01

    The 60 Co γ-radiolysis of aqueous solutions of sodium 9,10-anthraquinone-2-sulfonate has been studied in acidic, unbuffered, and alkaline conditions and with addition of N 2 O and 2-propanol. Mechanisms are proposed to account for the yields of H 2 O 2 and hydroxylated anthraquinone sulfonates. In neutral solution, in the absence of O 2 , the OH and e - adducts undergo preferential cross termination. Reduction of the OH adduct leads to dehydration and regeneration of the quinone. (author)

  9. sodium

    International Development Research Centre (IDRC) Digital Library (Canada)

    Les initiatives de réduction de la consommation de sel qui visent l'ensemble de la population et qui ciblent la teneur en sodium des aliments et sensibilisent les consommateurs sont susceptibles de réduire la consommation de sel dans toutes les couches de la population et d'améliorer la santé cardiovasculaire. Ce projet a ...

  10. Effects of sodium hydroxide (NaOH) solution concentration on fly ash-based lightweight geopolymer

    Science.gov (United States)

    Ibrahim, W. M. W.; Hussin, K.; Abdullah, M. M. A.; Kadir, A. A.; Deraman, L. M.

    2017-09-01

    In this study, the effects of NaOH concentration on properties of fly ash-based lightweight geopolymer were investigated. Lightweight geopolymer was produced using fly ash as source materials and synthetic foaming agents as air entraining agent. The alkaline solutions used in this study are combination of sodium hydroxide (NaOH) and sodium silicate (Na2SiO3) solution. Different molarities of NaOH solution (6M, 8M, 10M, 12M, and 14M) are taken for preparation of 50 x 50 x 50 mm cubes of lightweight geopolymer. The ratio of fly ash/alkaline solution, Na2SiO3/NaOH solution, foaming agent/water and foam/geopolymer paste were kept constant at 2.0, 2.5, 1:10 and 1:1 respectively. The samples were cured at 80°C for 24 hours and left at room temperature for tested at 7 days of ageing. Physical and mechanical properties such as density, water absorption, compressive strength and microstructure property were determined from the cube dried samples. The results show that the NaOH molarity had effects on the properties of lightweight geopolymer with the optimum NaOH molarity found is 12M due to the high strength of 15.6 MPa, lower water absorption (7.3%) and low density (1440 kg/m3). Microstructure analysis shows that the lightweight geopolymer contain some porous structure and unreacted fly ash particles remains.

  11. Effect of sodium tetraborate (borax) on the thermal properties of frozen aqueous sugar and polyol solutions.

    Science.gov (United States)

    Izutsu, Ken-ichi; Rimando, Annie; Aoyagi, Nobuo; Kojima, Shigeo

    2003-06-01

    The effect of sodium tetraborate (Na(2)B(4)O(7), borax) on the thermal property of frozen aqueous sugar and polyol solutions was studied through thermal analysis. Addition of borax raised the thermal transition temperature (glass transition temperature of maximally freeze-concentrated solutes; T(g)') of frozen sucrose solutions depending on the borax/sucrose concentration ratios. Changes in the T(g)' of frozen mono- and disaccharide solutions suggested various forms of complexes, including those of a borate ion and two saccharide molecules. Borax exerted the maximum effect to raise the oligosaccharide and dextran T(g)'s at borax/saccharide molar ratios of approximately 1-2 (maltose and maltooligosaccharides), 2 (dextran 1060), 5 (dextran 4900), and 10 (dextran 10200). Further addition of borax lowered T(g)'s of the saccharide solutions. Borax also raised T(g) and T(g)' temperatures of frozen aqueous glycerol solutions. The decreased solute mobility in frozen solutions by the borate-polyol complexes suggested higher collapse temperature in the freeze-drying process and improved stability of biological systems in frozen solutions.

  12. Recovering uranium and/or aluminium from refractory silico-aluminous material

    International Nuclear Information System (INIS)

    Livesey-Goldblatt, E.; Nagy, I.F.; Tunley, T.H.

    1983-01-01

    A process for recovering uranium and/or aluminium from a refractory silico-aluminous material comprises leaching the material in one or more stages, obtaining a pregnant solution which contains little or no acid and recovering the desired metal from the solution

  13. Corrosion of Spiral Rib Aluminized Pipe

    Science.gov (United States)

    2012-08-01

    Large diameter, corrugated steel pipes are a common sight in the culverts that run alongside many Florida roads. Spiral-ribbed aluminized pipe (SRAP) has been widely specified by the Florida Department of Transportation (FDOT) for runoff drainage. Th...

  14. Corrosion of Spiral Rib Aluminized Pipe : [Summary

    Science.gov (United States)

    2012-01-01

    Large diameter, corrugated steel pipes are a common sight in the culverts that run alongside many Florida roads. Spiral-ribbed aluminized pipe (SRAP) has been widely specified by the Florida Department of Transportation (FDOT) for runoff drainage. Th...

  15. Safe disposal of radioactive iodide ions from solutions by Ag2O grafted sodium niobate nanofibers.

    Science.gov (United States)

    Mu, Wanjun; Li, Xingliang; Liu, Guoping; Yu, Qianhong; Xie, Xiang; Wei, Hongyuan; Jian, Yuan

    2016-01-14

    Radioactive iodine isotopes are released into the environment by the nuclear industry and medical research institutions using radioactive materials, and have negative effects on organisms living within the ecosystem. Thus, safe disposal of radioactive iodine is necessary and crucial. For this reason, the uptake of iodide ions was investigated in Ag2O nanocrystal grafted sodium niobate nanofibers, which were prepared by forming a well-matched phase coherent interface between them. The resulting composite was applied as an efficient adsorbent for I(-) anions by forming an AgI precipitate, which also remained firmly attached to the substrates. Due to their one-dimensional morphology, the new adsorbents can be easily dispersed in liquids and readily separated after purification. This significantly enhances the adsorption efficiency and reduces the separation costs. The change in structure from the pristine sodium niobate to Ag2O anchored sodium niobate and to the used adsorbent was examined by using various characterization techniques. The effects of Ag(+) concentration, pH, equilibration time, ionic strength and competing ions on the iodide ion removal ability of the composite were studied. The Ag2O nanocrystal grafted sodium niobate adsorbent showed a high adsorption capacity and excellent selectivity for I(-) anions in basic solutions. Our results are useful for the further development of improved adsorbents for removing I(-) anions from basic wastewater.

  16. Derivatization of organometal(loid) species by sodium borohydride problems and solutions.

    Science.gov (United States)

    Grüter, U M; Hitzke, M; Kresimon, J; Hirner, A V

    2001-12-14

    Like other derivatization techniques, hydride generation is a chemical reaction that produces side-reactions leading to analytical problems. Demethylation of dimethylarsinic acid was observed to be dependent upon the pH level of the hydride generation reaction mixture. If the reaction mixture was acidic, then in addition to (CH3)2AsH, the monomethyl arsenic hydride [(CH3)AsH2] could be detected. Demethylation and also the formation of an unidentified arsenic species were noted when trimethyl arsonic oxide was used as derivatization educt. All of these effects depend on the pH level of the hydride generation mixture. We observed significant levels of organometal(loid) species of elements such as Ge, As, Sn, Sb, Hg and Bi in blank hydride generation mixtures. The organometal(loid) contamination was irreproducible even during I day using a single solution of sodium borohydride in deionized water. We concluded that the organometal(loid) contamination arises directly from the derivatization agent, sodium borohydride, itself. Use of helium purging and various adsorptive materials to decontaminate the sodium borohydride solution prior to analysis did not result in a significant decrease in organometal(loid) contamination levels. Use of a palladium-cluster stabilised with 1,10-phenanthrolin as alternative hydride generation derivatization agent was not found to be suitable, since reaction yields were poor and transmethylation reactions were noted.

  17. Characterizing AISI 1045 steel surface duplex-treated by alternating current field enhanced pack aluminizing and nitriding

    Science.gov (United States)

    Xie, Fei; Zhang, Ge; Pan, Jianwei

    2018-02-01

    Thin cases and long treating time are shortcomings of conventional duplex treatment of aluminizing followed by nitriding (DTAN). Alternating current field (ACF) enhanced DTAN was carried out on AISI 1045 steel by applying an ACF to treated samples and treating agents with a pair of electrodes for overcoming those shortcomings. By investigating cases' structures, phases, composition and hardness distributions of differently treated samples, preliminary studies were made on characterizations of the ACF enhanced duplex treatment to AISI 1045 steel. The results show that, with the help of the ACF, the surface Al-rich phase Al5Fe2 formed in conventional pack aluminizing can be easily avoided and the aluminizing process is dramatically promoted. The aluminizing case can be nitrided either with conventional pack nitriding or ACF enhanced pack nitriding. By applying ACF to pack nitriding, the diffusion of nitrogen into the aluminizing case is promoted. AlN, Fe2∼3N and solid solution of N in iron are efficiently formed as a result of reactions of N with the aluminizing case. A duplex treated case with an effective thickness of more than 170 μm can be obtained by the alternating current field enhanced 4 h pack aluminizing plus 4 h pack nitriding.

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

    Science.gov (United States)

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

    2016-01-01

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

  19. Effects and mechanism of ozonation for degradation of sodium acetate in aqueous solution

    Directory of Open Access Journals (Sweden)

    De-min Yang

    2012-06-01

    Full Text Available The degradation efficiencies and mechanism of ozonation for the degradation of sodium acetate in aqueous solution were investigated under atmospheric pressure at room temperature (293 K. The effects of the initial pH value, reaction time, and concentrations of HCO3−, CO32− CaCl2 and Ca(OH2 on the removal rate of chemical oxygen demand (COD were studied. The results indicated that ozonation obviously improved the degradation rate of sodium acetate when the pH value of the solution was not less than 8.5. A suitable long reaction time may be helpful in increasing the COD removal rate, and a removal rate of 36.36% can be obtained after a 30-minute treatment. The COD removal rate increased firstly and decreased subsequently with the increase of the HCO3− concentration (from 0 to 200 mg/L, and under the same experimental condition it reached the optimum 34.66% at the HCO3− concentration of 100 mg/L. The COD removal rate was 5.26% lower when the concentration of HCO3− was 200 mg/L than when there was no HCO3−. The COD removal rate decreased by 15.68% when the CO32− concentration increased from 0 to 200 mg/L. CO32− has a more obvious scavenging effect in inhibiting the formation of hydroxyl radicals than HCO3−. CaCl2 and Ca(OH2 could increase the degradation efficiency of sodium acetate greatly, and the COD removal rates reached 65.73% and 83.46%, respectively, after a 30-minute treatment, 29.37% and 47.10% higher, respectively, than with single ozone oxidation. It was proved that the degradation of sodium acetate in the ozonation process followed the mechanism of oxidization with hydroxyl free radicals (·OH.

  20. Characterization of Laboratory Prepared Concrete Pastes Exposed to High Alkaline and High Sodium Salt Solutions

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-06-30

    The objective of this study was to identify potential chemical degradation mechanisms for the Saltstone Disposal Unit (SDU) concretes, which over the performance life of the structures may be exposed to highly alkaline sodium salt solutions containing sulfate, hydroxide, and other potentially corrosive chemicals in salt solution and saltstone flush water, drain water, leachate and / or pore solution. The samples analyzed in this study were cement pastes prepared in the SIMCO Technologies, Inc. concrete laboratory. They were based on the paste fractions of the concretes used to construct the Saltstone Disposal Units (SDUs). SDU 1 and 4 concrete pastes were represented by the PV1 test specimens. The paste in the SDU 2, 3, 5, and 6 concrete was represented by the PV2 test specimens. SIMCO Technologies, Inc. selected the chemicals and proportions in the aggressive solutions to approximate proportions in the saltstone pore solution [2, 3, 5, and 6]. These test specimens were cured for 56 days in curing chamber before being immersed in aggressive solutions. After exposure, the samples were frozen to prevent additional chemical transport and reaction. Selected archived (retrieved from the freezer) samples were sent to the Savannah River National Laboratory (SRNL) for additional characterization using x-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive x-ray (EDX) spectroscopy. Characterization results are summarized in this report. In addition, a correlation between the oxide composition of the pastes and their chemical durability in the alkaline salt solutions is provided.

  1. Analysis of the sodium recirculation theory of solute-coupled water transport in small intestine

    DEFF Research Database (Denmark)

    Larsen, Erik Hviid; Sørensen, Jakob Balslev; Sørensen, Jens Nørkaer

    2002-01-01

    Our previous mathematical model of solute-coupled water transport through the intestinal epithelium is extended for dealing with electrolytes rather than electroneutral solutes. A 3Na+-2K+ pump in the lateral membranes provides the energy-requiring step for driving transjunctional and translateral...... permeabilities and pump constants of fluxes of water and electrolytes, volumes and ion concentrations of cell and lateral intercellular space (lis), and membrane potentials and conductances. Simulating physiological bioelectrical features together with cellular and paracellular fluxes of the sodium ion......, computations predict that the concentration differences between lis and bathing solutions are small for all three ions. Nevertheless, the diffusion fluxes of the ions out of lis significantly exceed their mass transports. It is concluded that isotonic transport requires recirculation of all three ions...

  2. Density, thermal expansion coefficient and viscosity of sodium tetraborate (borax)-UO2 and of sodium metaborate-UO2 solutions at high temperatures

    International Nuclear Information System (INIS)

    Dalle Donne, M.; Dorner, S.; Roth, A.

    1983-01-01

    Measurements have been performed of the density, of the volumetric thermal expansion coefficient and of the viscosity of liquid sodium tetraborate (borax) and of sodium metaborate both pure and with two different amounts of UO 2 dissolved in each. The viscosity measurements have been performed for the solution of sodium tetraborate with UO 2 and CeO 2 , and with CeO 2 only as well. These data are required for the design of core-catchers based on sodium borates. The density measurements have been performed with the buoyancy method in the temperature range from 825 0 C to 1300 0 C, the viscosity measurements in the temperature range 700-1250 0 C with a modified Haake viscosity balance. The balance was previously calibrated at ambient temperature with a standard calibration liquid and at high temperatures, with data for pure borax available from the literature. (orig.)

  3. Contracture Coupling of Slow Striated Muscle in Non-Ionic Solutions and Replacement of Calcium, Sodium, and Potassium

    Science.gov (United States)

    Irwin, Richard L.; Hein, Manfred M.

    1964-01-01

    The development of contracture related to changes of ionic environment (ionic contracture coupling) has been studied in the slowly responding fibers of frog skeletal muscle. When deprived of external ions for 30 minutes by use of solutions of sucrose, mannitol, or glucose, the slow skeletal muscle fibers, but not the fast, develop pronounced and easily reversible contractures. Partial replacement of the non-ionic substance with calcium or sodium reduces the development of the contractures but replacement by potassium does not. The concentration of calcium necessary to prevent contracture induced by a non-ionic solution is greater than that needed to maintain relaxation in ionic solutions. To suppress the non-ionic-induced contractures to the same extent as does calcium requires several fold higher concentrations of sodium. Two types of ionic contracture coupling occur in slow type striated muscle fibers: (a) a calcium deprivation type which develops maximally at full physiological concentration of external sodium, shows a flow rate dependency for the calcium-depriving fluid, and is lessened when the sodium concentration is decreased by replacement with sucrose; (b) a sodium deprivation type which occurs maximally without external sodium, is lessened by increasing the sodium concentration, and has no flow rate dependency for ion deprivation. Both types of contracture are largely prevented by the presence of sufficient calcium. There thus seem to be calcium- and sodium-linked processes at work in the ionic contracture coupling of slow striated muscle. PMID:14127603

  4. Enthalpies of Dissolution of Crystalline Naproxen Sodium in Water and Potassium Hydroxide Aqueous Solutions at 298 K

    Science.gov (United States)

    Lytkin, A. I.; Chernikov, V. V.; Krutova, O. N.; Bychkova, S. A.; Volkov, A. V.; Skvortsov, I. A.

    2018-03-01

    The enthalpies of dissolution of crystalline naproxen sodium in water and aqueous solutions of KOH at 298.15 K are measured by direct calorimetric means in a wide range of concentrations. The acid-base properties of naproxen sodium at ionic strength I 0 and I = 0.1 (KNO3) and a temperature of 298.15 K are studied by spectrophotometric means. The concentration and thermodynamic dissociation constants are determined. The standard enthalpies of the formation of naproxen sodium and the products of its dissociation in aqueous solution are calculated.

  5. Hydraulic conductivity in response to exchangeable sodium percentage and solution salt concentration

    Directory of Open Access Journals (Sweden)

    Jefferson Luiz de Aguiar Paes

    2014-10-01

    Full Text Available Hydraulic conductivity is determined in laboratory assays to estimate the flow of water in saturated soils. However, the results of this analysis, when using distilled or deionized water, may not correspond to field conditions in soils with high concentrations of soluble salts. This study therefore set out to determine the hydraulic conductivity in laboratory conditions using solutions of different electrical conductivities in six soils representative of the State of Pernambuco, with the exchangeable sodium percentage adjusted in the range of 5-30%. The results showed an increase in hydraulic conductivity with both decreasing exchangeable sodium percentage and increasing electrical conductivity in the solution. The response to the treatments was more pronounced in soils with higher proportion of more active clays. Determination of hydraulic conductivity in laboratory is routinely performed with deionized or distilled water. However, in salt affected soils, these determinations should be carried out using solutions of electrical conductivity different from 0 dS m-1, with values close to those determined in the saturation extracts.

  6. Slow scan voltammetry for diffusion-controlled currents in sodium alginate solutions

    OpenAIRE

    Wang, Bo; Aoki, Koichi Jeremiah; Chen, Jingyuan; Nishiumi, Toyohiko

    2013-01-01

    Slow scan voltammetry is useful for extracting Faradaic diffusion-controlled currentfrom capacitive one, because the former and the latter are, respectively, proportional tothe square-root of scan rate and the scan rate itself. This report shows clear, reproduciblevoltammograms of 0.5μM redox species with the help of sodium alginate(SA)at scanrates less than 0.1 mV s-1. SA enhances viscosity of solution without any influence ondiffusion coefficient of the redox species so that natural convent...

  7. Removal of radioactive Cs from nonwoven cloth with less waste solution using aqueous sodium metasilicate

    International Nuclear Information System (INIS)

    Ueda, Yoshikatsu; Tokuda, Yomei; Goto, Hiroshi; Kobayashi, Tomoyuki; Ono, Yuji

    2013-01-01

    Remediation of nonwoven cloth contaminated with radioactive material such as 137 Cs is important for the reuse of protective garments. Here, we report the effectiveness of aqueous sodium metasilicate prepared with a microbubble crushing process (SMC) in the removal of radioactive 137 Cs from nonwoven cloth. The 137 Cs removal ratio obtained using SMC was found to be 78%, and multiple washings at low SMC concentrations were effective. In addition, the volume of the waste solution could be reduced by neutralizing the SMC and using gelation to remove the radioactive material. (author)

  8. The Effect of Sodium Hyaluronate plus Sodium Chondroitin Sulfate Solution on Peritendinous Adhesion and Tendon Healing: An Experimental Study

    Directory of Open Access Journals (Sweden)

    Hacı Bayram Tosun

    2016-06-01

    Full Text Available Background: Adhesion formation following tendon injury is a serious clinical problem. Aims: In this experimental study, the effects of the combination of sodium hyaluronate (HA and chondroitin sulfate (CS on peritendinous adhesion and tendon healing were evaluated. Study Design: Animal experimentation. Methods: Twenty-one mature Sprague Dawley male rats were randomly divided into three equal groups. The rats’ Achilles tendons were cut and repaired with a modified Kessler technique. About 0.25 and 0.50 mL of the HA and CS (HA+CS combination were injected subcutaneously into the repair site of the rats in groups 1 and 2, respectively, on days 0, 3, 7, and 10. The subjects in group 3 were used as the control group. At 6 weeks, all rats were euthanized. The tenotomy site was examined macroscopically in all animal subjects. Four samples were assigned to the histopathological examination group, and the others were assigned to the biomechanical assessment group. Results: Inflammation and adhesion in both treatment groups were observed at a lower rate than in the control group. The collagen filaments in both treatment groups were regular and the number was low when compared to the control group. However, there was no statistically significant difference between group 1 and the control group. The quantity, quality, and grade of the adhesions were statistically significantly lower in group 2 when compared with the other groups. The mean maximum stress strength in group 2 was statistically significantly higher than that in group 1 and the control group. Conclusion: Local administration of the HA+CS combination solution is a valid tool for preventing peritendinous adhesion after extrasynovial tendon repair such as Achilles tendon, and is a treatment option in such cases.

  9. Study of the chemical species of fluorine 18 produced by neutron irradiation of lithium aluminate

    International Nuclear Information System (INIS)

    Jimenez-Becerril, J.

    1990-01-01

    In the present work, the chemical form of fluorine-18 obtained by means of the neutron irradiated lithium aluminate was studied, in order to know its chemical behavior and to observe if it volatilizes and adheres to the walls of a tritium distillation system; for this matter paper chromatography and high voltage electrophoresis techniques were used. Lithium aluminate was synthetized, being characterized as LiAlO 2 which was irradiated with neutrons in order to produce fluorine-18. Lithium aluminate is a non-soluble solid, therefore fluorine produced may not be extracted, unless it is dissolved or extracted through the solid. So as not affect in a drastic way the chemical form, it was submitted to extraction processes, agitating the irradiated samples with different acids and basic solutions in order to analyze fluorine-18. The best extraction agent was found to be HCl, where two forms of fluorine-18 were found, one at the point of application, probably as a complex hexafluoride-aluminate and the other as a characteristic Rf of the fluorine ion. In the tritium distillation with helium as a carrier of a sample irradiated and heated up to 220-250 o C, no volatile types of fluorine-18 were found, thus it can be considered that in commercial production of tritium by means of neutron irradiation of lithium aluminate, fluorine-18 is not a damaging pollutant of the equipment pipe system. (Author)

  10. Bactericidal effects of Nd:YAG laser irradiation and sodium hypochlorite solution on Enterococcus faecalis biofilm.

    Science.gov (United States)

    Rahimi, Saeed; Shahi, Shahriar; Gholizadeh, Seddigheh; Shakouie, Sahar; Rikhtegaran, Sahand; Soroush Barhaghi, Mohammad Hossein; Ghojazadeh, Morteza; Froughreyhani, Mohammad; Abdolrahimi, Majid

    2012-11-01

    The aim of this study was to evaluate the bactericidal effects of Nd:YAG laser on biofilm of Enterococcus faecalis. It is difficult to eliminate bacterial biofilms with routine endodontic preparation techniques. It might be possible to eliminate biofilms remaining in the root canals of teeth with lasers. The root canals of 60 extracted teeth were prepared and E. faecalis biofilms were formed within the root canals. Then the teeth were randomly divided into four groups of 15. Group 1 samples did not undergo any interventions, to serve as controls. Group 2 samples underwent a 3-W laser beam for 10 sec. The root canals in group 3 were irrigated with 1% sodium hypochlorite for 15 min and then irradiated with a 3-W laser beam for 10 sec. The root canals in group 4 were irrigated with 1% sodium hypochlorite for 15 min. Dentin chips were collected from the root canal walls and weighed. Then the chips were used to prepare a suspension. The classic colony-forming unit (CFU) counting technique was used to determine remaining bacterial counts. The bacterial counts in groups 2 and 4 had decreased to 54% and 2.39% of the control group, respectively. In group 3 no bacterial growth was observed. There were no significant differences between groups 1 and 2 (p>0.05). Based on the results of the present study, the effect of Nd:YAG laser beam on E. faecalis biofilm is less than that of sodium hypochlorite solution. A combination of laser and sodium hypochlorite results in complete elimination of E. faecalis biofilm.

  11. Process of transformation of radioactive waste of metal sodium into soda solution by reaction with an alcohol followed by hydrolysis

    International Nuclear Information System (INIS)

    Chevalier, Gerard; Mathurin, Rene.

    1981-09-01

    Reviews of the literature and of the laboratory tests are followed by a presentation of the results obtained during experiments carried out on a model with some ten grams of sodium contaminated by radioactive materials and on an industrial pre-pilot with several kilograms of non-contaminated sodium. Sodium is converted into alcoholate through the action of ethylcarbitol (CH 3 CH 2 OCH 2 CH 2 OCH 2 OH) on liquid sodium in suspension in xylene at 110 deg C. Once the reaction is complete, xylene is distillated and the alcoholate is in solution in an axcess of alcohol. Hydrolysis by water gives out the initial alcohol which is then extracted from the aqueous phase by toluene. All these operations are carried out in inert atmosphere (nitrogen). Sodium is thus converted into a sodium hydroxide aqueous solution with emission of hydrogen, the intermediate products (alcohol, xylene, toluene) being recyled. The process is reliable and recycling of organic products is favourable economically. The advantage of the method is to concentrate nearly all the radioactivity of the contaminated sodium in the aqueous phase, thus avoiding the dispersion of activity especially with the gaseous effluents. Finally, data are given allowing to consider the realization of a pilot with a weekly capacity of 100 kg of sodium, in semi-continuous operation [fr

  12. Formation of metastabil liquid phases in the isotonic solution of sodium cloraide during cooling

    Directory of Open Access Journals (Sweden)

    A. T. Ходько

    2016-07-01

    Full Text Available In this paper the cooling process cryomicroscopy of 0.15 M of isotonic sodium chloride solution was conducted. It was shown that there is liquid – liquid phase change before the crystallization process. As a result, the coarse system (highly concentrated emulsion was formed. The dispersed phase and the disperse medium in a binary system with the same qualitative chemical composition differ in concentration. Therefore, the greater is the volume ratio of the coexisting phases, the greater is the difference in their quantitative compositions. The dispersed phase, that composes the main volume in the system under investigation, should have lower NaCl concentration than the disperse medium and the initial solution. In this case it will be hypotonic (and disperse medium – hypertonic in relation to cytoplasm of human internal environment. This physical-chemical factor, which hasn’t been considered previously, might be responsible for osmotic damage in living cells during cryopreservation of cell suspensions.

  13. Effect of ion concentrations on uranium absorption from sodium carbonate solutions

    International Nuclear Information System (INIS)

    Traut, D.E.; El Hazek, N.M.T.; Palmer, G.R.; Nichols, I.L.

    1979-01-01

    The effect of various ion concentrations on uranium absorption from a sodium carbonate solution by a strong-base, anion resin was investigated in order to help assure an adequate uranium supply for future needs. The studies were conducted to improve the recovery of uranium from in situ leach solutions by ion exchange. The effects of carbonate, bicarbonate, chloride, and sulfate ions were examined. Relatively low (less than 5 g/l) concentrations of chloride, sulfate, and bicarbonate were found to be detrimental to the absorption of uranium. High (greater than 10 g/l) carbonate concentrations also adversely affected the uranium absorption. In addition, the effect of initial resin form was investigated in tests of the chloride, carbonate, and bicarbonate forms; resin form was shown to have no effect on the absorption of uranium

  14. Influence of hydroxypropylmethyl cellulose-sodium laurylsulfate interaction on rheological properties of the solution

    Directory of Open Access Journals (Sweden)

    Šaletić Jelena V.

    2004-01-01

    Full Text Available Interactions between the polymers and surfactants in solution have widely been investigated because of their scientific and technological importance. These interactions can be utilized to modify the physicochemical properties of system in many food products, pharmaceutical formulations, personal care products, paints, pesticides, etc. Interaction between nonionic polymer - hydroxypropylmethyl cellulose (HPMC and anionic surfactant - sodium laurylsulfate (SDS in solution has been investigated in this paper by rheological measurements. Rheological measurements are performed by rotational viscometer at 20°C and changes of rheological characteristics of HPMC solutions (0.5-1.5% with increasing SDS concentrations (0-4.0% were determined. The results of these investigations showed that viscosity of the solution is dependant on HPMC-SDS interaction. At particular SDS concentration viscosity increases, reach maximum and after that decreases until reach constant value. From the viscosity changes the characteristic concentrations of SDS, critical aggregation concentration (cac and polymer saturation point (psp, were determined. These concentrations are in linear relationships with HPMC concentrations. Rheological properties of the solution are strong influenced by HPMC-SDS interaction and exhibits more or less pronounced pseudoplastic behavior, which changes to Newtonian one after the psp has been reached.

  15. Evaluation of poly (aspartic acid sodium salt) as a draw solute for forward osmosis.

    Science.gov (United States)

    Gwak, Gimun; Jung, Bokyung; Han, Sungsoo; Hong, Seungkwan

    2015-09-01

    Poly (aspartic acid sodium salt) (PAspNa) was evaluated for its potential as a novel draw solute in forward osmosis (FO). The inherent advantages of PAspNa, such as good water solubility, high osmotic pressure, and nontoxicity, were first examined through a series of physicochemical analyses and atomic-scale molecular dynamics simulations. Then, lab-scale FO tests were performed to evaluate its suitability in practical processes. Compared to other conventional inorganic solutes, PAspNa showed comparable water flux but significantly lower reverse solute flux, demonstrating its suitability as a draw solute. Moreover, fouling experiments using synthetic wastewater as a feed solution demonstrated that PAspNa reversely flowed to the feed side reduced inorganic scaling on the membrane active layer. The recyclability of PAspNa was studied using both nanofiltration (NF) and membrane distillation (MD) processes, and the results exhibited its ease of recovery. This research reported the feasibility and applicability of FO-NF or FO-MD processes using PAspNa for wastewater reclamation and brackish water desalination. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Molecular dynamics studies on the thermodynamics of supercooled sodium chloride aqueous solution at different concentrations.

    Science.gov (United States)

    Corradini, D; Gallo, P; Rovere, M

    2010-07-21

    In this paper we compare recent results obtained by means of molecular dynamics computer simulations on the thermodynamics of TIP4P bulk water and on solutions of sodium chloride in TIP4P water. The concentrations studied are c = 0.67, 1.36 and 2.10 mol kg( - 1). The results are checked against change of water-salt potential and size effects. The systems are studied in a wide range of temperatures, going from ambient temperature to the supercooled region. Analysis of simulated state points, performed on the isochores and on the isotherm plane, allowed the determination of the limit of mechanical stability and of the temperature of maximum density lines. While the presence of ions in the system does not affect the limit of mechanical stability with respect to the bulk, it causes the temperature of the maximum density line to shift to lower pressure and temperature upon increasing concentration. The occurrence of minima in the trend of potential energy as a function of density and the inflections in the low temperature isotherms suggest the presence of liquid-liquid coexistence for bulk water and for the sodium chloride solutions at all concentrations studied.

  17. Structure of liquid tricalcium aluminate

    Science.gov (United States)

    Drewitt, James W. E.; Barnes, Adrian C.; Jahn, Sandro; Kohn, Simon C.; Walter, Michael J.; Novikov, Alexey N.; Neuville, Daniel R.; Fischer, Henry E.; Hennet, Louis

    2017-02-01

    The atomic-scale structure of aerodynamically levitated and laser-heated liquid tricalcium aluminate (Ca3Al2O6 ) was measured at 2073(30) K by using the method of neutron diffraction with Ca isotope substitution (NDIS). The results enable the detailed resolution of the local coordination environment around calcium and aluminum atoms, including the direct determination of the liquid partial structure factor, SCaCa(Q ) , and partial pair distribution function, gCaCa(r ) . Molecular dynamics (MD) simulation and reverse Monte Carlo (RMC) refinement methods were employed to obtain a detailed atomistic model of the liquid structure. The composition Ca3Al2O6 lies at the CaO-rich limit of the CaO:Al2O3 glass-forming system. Our results show that, although significantly depolymerized, liquid Ca3Al2O6 is largely composed of AlO4 tetrahedra forming an infinite network with a slightly higher fraction of bridging oxygen atoms than expected for the composition. Calcium-centered polyhedra exhibit a wide distribution of four- to sevenfold coordinated sites, with higher coordinated calcium preferentially bonding to bridging oxygens. Analysis of the MD configuration reveals the presence of ˜10 % unconnected AlO4 monomers and Al2O7 dimers in the liquid. As the CaO concentration increases, the number of these isolated units increases, such that the upper value for the glass-forming composition of CaO:Al2O3 liquids could be described in terms of a percolation threshold at which the glass can no longer support the formation of an infinitely connected AlO4 network.

  18. Formation of fine solid particles from aqueous solutions of sodium chloropalladate by gamma-ray irradiation

    International Nuclear Information System (INIS)

    Hatada, Motoyoshi; Fujita, Iwao; Korekawa, Kei-ichi.

    1994-10-01

    Studies have been carried out on the radiation chemical formation of palladium fine particles in argon saturated aqueous solutions of sodium chloropalladate without organic stabilizer. The solutions were irradiated with gamma-rays from a cobalt gamma-ray source and the irradiated solutions were subjected to the dynamic light scattering analysis for the particle diameter measurements, and to the UV-visible optical absorption spectroscopy for the measurements of turbidity (absorption at 700 nm) and remaining chloropalladate ion concentrations in the solution. In the solution of pH = 1.95 by HCl, the turbidity increased after the irradiation and then decreased with time. The concentration of remaining palladate ion in the solution decreased by the irradiation, but it gradually increased with time after the irradiation. These phenomena were qualitatively explained by the reaction scheme in that a precursor to the solid particles still exists in the solution after the irradiation was terminated, and that intermediates including the precursor reacted with chloride ion to re-form chloropalladate ions. The average diameter of the particles after the irradiation was ca. 20 nm and it increased with time to 40 nm at 2.75 kGy, and to 80 nm at 8.25 kGy absorption of radiation. The solution of pH = 0.65 by HCl was found to give lower yields of particles than those observed for the solution of pH = 1.95, and to give the particles of diameters about 150-200 nm. In the solution containing HClO 4 instead of HCl, palladium particles were also formed by the irradiation, whereas no backward reaction after the irradiation was observed due to the low concentration of chloride ion in the solution. The average diameter of the particles after the irradiation was about 300 nm and increased with time after the irradiation to a final values which was found to depend on pH of the solution and dose. (author)

  19. Effect of controlled deactivation on the thermochemical characteristics of hydrogen adsorption on skeletal nickel from sodium hydroxide-water solutions

    Science.gov (United States)

    Prozorov, D. A.; Lukin, M. V.; Ulitin, M. V.

    2013-04-01

    Differential heats of adsorption in a wide range of surface coverage and maximum amounts of adsorbed hydrogen are determined by adsorption calorimetry on partially deactivated skeletal nickel from aqueous solutions of sodium hydroxide. The effect of the composition of solutions on the values of limiting adsorption and adsorption equilibria of individual forms of hydrogen is shown.

  20. Effects of Metal Ions on Viscosity of Aqueous Sodium Carboxylmethylcellulose Solution and Development of Dropping Ball Method on Viscosity

    Science.gov (United States)

    Set, Seng; Ford, David; Kita, Masakazu

    2015-01-01

    This research revealed that metal ions with different charges could significantly affect the viscosity of aqueous sodium carboxylmethylcellulose (CMC) solution. On the basis of an Ostwald viscometer, an improvised apparatus using a dropping ball for examining the viscosity of liquids/solutions has been developed. The results indicate that the…

  1. THE DIGESTION OPERATION IN THE ALKALI ALUMINAT SOLUTIONS OF ALUMINUM HYDROXIDES IN THE BOEHMITIC BAUXITES

    Directory of Open Access Journals (Sweden)

    Sami ŞAHİN

    1999-01-01

    Full Text Available At present more than 90 per cent of the world's alumina is produced by the Bayer process, a simple technology providing high purity final product. A part from some exceptional local conditions, bauxite is processed almost solely by this technology. As a benefication process, alumina production releases the aluminum oxide content of bauxite from other accompanying oxides thus providing alumina suitable for electrolysis in a cryolite melt. The basic theory of the Bayer process was elaborated by K.J. Bayer and described in his patents in 1887 and 1892. The first patent refers to the aid of seed crystals of aluminum hydroxide or of carbonic acid, that is, to the precipitation and carbonation processes. The second patent formulates the concept that the aluminum oxide content of bauxites can be dissolved in sodium hydroxide solutions, with the formulation of sodium aluminate, a process called digestion nowadays. The most important operations of the Bayer technology are bauxite preparation, crushing, grinding, digestion, red mud separation, thickening, washing, filtration, precipitation, calcination and evaporation. In spite of its great significance as regards the complete Bayer technology, the structure of sodium aluminate solutions has not been cleared up definitely yet. Boehmite is the most important aluminum mineral of karstic bauxites. Some experimental results showing the various effects on aluminum hydroxides by alkali process from boehmitic bauxites and the factors gowerning the digestion operation of aluminate solutions were investigated.

  2. Clinical application of sodium hyaluronate,levarterenol and indicarmine solution in endoscopic submucosal dissection

    Directory of Open Access Journals (Sweden)

    Fei GAO

    2011-07-01

    Full Text Available Objective To assess the clinical value of sodium hyaluronate,levarterenol and indicarmine solution used in endoscopic submucosal dissection(ESD.Methods Sixteen patients were involved in present study who were diagnosed as precancerous lesion or submucosal tumor in digestive tract by chromoendoscopy and endoscopic ultrasonography from Nov,2010 to Feb,2011 at General Hospital of Shenyang Command.The injected solution was mixed with 0.2% indicarmine 10ml,levarterenol 10mg,sodium hyaluronate 20mg,and 0.9% normal saline 200ml.The liquid pad was formed under the submucosal layer by the injection of the mixture.Hybrid knife was employed to perform the injection,cutting and coagulation with no interruption during the procedure of ESD.Satisfactory degree was assessed,and the total solution volume,success rate,bleeding rate,perforation rate,operation duration,and length of stay in hospital were recorded.The recurrence and healing condition were observed at following-up.Results The length of lesion was 0.8~4.5cm with mean of 2.2cm.The operation duration was 45~240 min with an mean time of 95.4 min.The mean dosage of the mixed solution for submucosal injection was 102.4ml.Success rate of endoscopic submucosal dissection was 87.5%.The satisfactory degree was high.Intractable bleeding occurred in 2 cases with lateral spreading tumor(LST during the procedure,but it was controlled after high temperature coagulation without producing perforation.The dissection surface was covered by aluminum phosphate gel in all cases,and metal clips were applied in some cases for closure.The mean length of stay in hospital after ESD was 3.8 days.Conclusions The mixture of sodium hyaluronate,levarterenol,indicarmine and normal saline,when used for submucosal injection in ESD,is safe and satisfactory.

  3. Anion-exchange method of ammonium paratungstate production from sodium carbonate solutions

    International Nuclear Information System (INIS)

    Kholmogorov, A.G.; Vaneeva, T.D.; Yurkevich, T.N.

    1978-01-01

    An anion exchange method is suggested for producing ammonium paratungstate from soda solutions for industrial testing. The suggested method allows the process cycle ot be reduced as a result of sorption of tungsten on anionite, followed by desorption of tungsten in form of ammonium tungstate, and by the recovery of the anionite by the solution of a mineral acid. The sorption of tungsten has been carried out in columns having the counter-flow gravitational motion, the desorption in a suspended layer of ionite. It has been established that for the sorption of tungsten it is desirable to use AN-80 P anionite, and that it is expedient to carry out the process with the use of solutions having pH=4 to 2.5. The apparatus flowsheet is presented of an enlarged setup for the production of ammonium paratugstate from the solutions of sodium tungstate. As compared with the deposition method, an increase in the yield of tungsten is achieved by a value of 1.3 to 1.5%. The economical efficiency of the developed method amounts to about 330 rubles per ton of tungsten anhydride

  4. Compressive Strength of Fly ash-based Geopolymer Concrete with a Variable of Sodium Hydroxide (NaOH Solution Molarity

    Directory of Open Access Journals (Sweden)

    Herwani

    2018-01-01

    Full Text Available Geopolymer concrete is a new material made by activating the raw materials which contain many elements of silica and alumina. Compressive strength of geopolymer concrete produced was influenced by the concentration of the activator solution. This paper presents an experimental investigation into fly ash-based geopolymer concrete. Research objective was to investigate the effects of alkaline activator solution (AAS molarity on compressive strength of geopolymer concrete. Variable of the test were a solution to sodium hydroxide was chosen as the activator solution. Concentration of sodium hydroxide solution used was 10 M, 12 M and 14 M with ambient curing. The specimen is made of concrete cylinder with diameter 10 cm and height 20 cm as many as 9 pieces each variable. Compressive strength tests is performed when the concrete is 7, 14, and 28 days old. Results of the test are indicated that the increasing of sodium hydroxide (NaOH solution concentration leads to improve the compressive strength of geopolymer concrete. The optimal compressive strength of geopolymer concrete was achieved at a concentration of sodium hydroxide solution (NaOH of 12 M. Geopolymer concretes compressive strength only achieves around 50-60% of the planned.

  5. Acid–base and hemodynamic status of patients with intraoperative hemorrhage using two solution types: Crystalloid Ringer lactate and 1.3% sodium bicarbonate in half-normal saline solution

    Directory of Open Access Journals (Sweden)

    Sayed Jalal Hashemi

    2016-01-01

    Conclusion: 1.3% sodium bicarbonate in half-normal saline solution can lead to a proper correction of hemodynamic instability. By maintaining hemodynamic status, osmolarity and electrolytes as well as better balance of acid–base, 1.3% sodium bicarbonate solution in half-normal saline solution can be more effective than Ringer lactate solution during intraoperative bleeding.

  6. The Removal of Cu (II) from Aqueous Solution using Sodium Borohydride as a Reducing Agent

    Science.gov (United States)

    Sithole, N. T.; Ntuli, F.; Mashifana, T.

    2018-03-01

    The removal and recovery of metals from wastewater has been a subject of significant importance due the negative impact these toxic metals have on human health and the environment as a result of water and soil pollution. Increased use of the metals and chemicals in the process industries has resulted in generation of large quantity of effluents that contains high level of toxic metals and other pollutants. The objective of this work was to recover of Cu in its elemental form as metallic powder from aqueous solution using NaBH4 as a reducing agent. Reductive precipitation was achieved in a batch reactor at 65°C using Cu powder as a seeding material. This study also investigated the effect of concentration of sodium borohydride (NaBH4) as a reducing agent. The amount of NaBH4 was varied based on mole ratios which are 1:1, 1:0.25 and 1:0.1 to recover Cu from synthetic wastewater. The results obtained showed that sodium borohydride is an effective reducing agent to recover Cu from wastewater. The optimum concentration of NaBH4 that gives the best results the 1:1 molar ratio with over 99% Cu removal.

  7. Effect of Hofmeister series salts on Absorptivity of aqueous solutions on Sodium polyacrylate

    Science.gov (United States)

    Korrapati, Swathi; Pullela, Phani Kumar; Vijayalakshmi, U.

    2017-11-01

    Sodium polyacrylate (SPA) is a popular super absorbent commonly used in children diapers, sanitary pads, adult diapers etc. The use of SPA is in force from past 30 years and the newer applications like as food preservant are evolving. SPA is recently discovered by our group for improvement of sensitivity of colorimetric agents. Though the discovery of improvement in sensitivity is phenomenal, the mechanism still remains a puzzle. A typical assay reagent contains colorimetric/fluorescent reagents, buffers, salts, stabilizers etc. These chemicals are known to influence the water absorptivity of SPA. If we were to perform chemical/biochemical assays on SPA absorbed reagents effect of salts and other excipients on colorimetric/fluorescence compounds absorbed on SPA is very important. The hofmeister series are standard for studying effect of salts on permeability, stability, aggregation, fluorescence quenching etc. We recently studied affect of urea, sodium chloride, ammonium sulfate, guanidine thiocayanate on fluorescence characteristics of fluorescence compounds and noted that except urea all other reagents have resulted in fluorescence quenching and urea had an opposite effect and increased the fluorescence intensity. This result was attributed to the different water structure around fluorescent in urea solution versus other chaotropic agents.

  8. Randomized study comparing two regimens of oral sodium phosphates solution versus low-dose polyethylene glycol and bisacodyl.

    Science.gov (United States)

    Malik, Pramod; Balaban, David H; Thompson, William O; Galt, Deborah J B

    2009-04-01

    Low-volume bowel preparation regimens for colonoscopy are reported to improve patient acceptance and compliance. We sought to compare the bowel cleansing efficacy, tolerability, and acceptability of three low-volume regimens: an oral sodium phosphates solution 45/45 ml (NaP-45/45), a reduced-dose oral sodium phosphates solution 45/30 ml (NaP-45/30), and polyethylene glycol plus bisacodyl (PEG-2L). A total of 121 patients were evaluated (mean age 55.2 +/- 8.9 years). Bowel cleansings rated as excellent and good were significantly different among the groups: NaP-45/45 = 98%, NaP-45/30 = 88%, and PEG-2L = 76% (P phosphates regimens (88, 95, and 73%, respectively; P = 0.019). Better cleansing and willingness to retake the regimen was achieved with the oral sodium phosphates solutions than with polyethylene glycol plus bisacodyl.

  9. Sodium bicarbonate versus isotonic saline solution to prevent contrast-induced nephropathy : a systematic review and meta-analysis.

    Science.gov (United States)

    Zapata-Chica, Carlos Andres; Bello Marquez, Diana; Serna-Higuita, Lina Maria; Nieto-Ríos, John Fredy; Casas-Arroyave, Fabian David; Donado-Gómez, Jorge Hernando

    2015-09-30

    Contrast-induced nephropathy is one of the main causes of acute kidney injury and increased hospital-acquired morbidity and mortality. The use of sodium bicarbonate for nephroprotection has emerged as a preventative strategy; however, its efficacy is controversial compared to other strategies, such as hydration using 0.9% saline solution. To compare the effectiveness of sodium bicarbonate vs. hydration using 0.9% saline solution to prevent contrast-induced acute kidney injury. A systematic review of studies registered in the COCHRANE, PUBMED, MEDLINE, LILACS, SCIELO and EMBASE databases was conducted. Randomized controlled studies that evaluated the use of 0.9% saline solution vs. sodium bicarbonate to prevent contrast-induced nephropathy were included. A total of 22 studies (5,686 patients) were included. Sodium bicarbonate did not decrease the risk of contrast-induced nephropathy (RD= 0.00; 95% CI= -0.02 to 0.03; p= 0.83; I(2)= 0%). No significant differences were found in the demand for renal replacement therapy (RD= 0.00; 95% CI= -0.01 to 0-01; I(2)= 0%; p= 0.99) or in mortality (RD= -0.00; 95% CI= -0.001 to 0.001; I(2)= 0%; p= 0.51). Sodium bicarbonate administration is not superior to the use of 0.9% saline solution for preventing contrast-induced nephropathy in patients with risk factors, nor is it better at reducing mortality or the need for renal replacement therapy.

  10. The Role of an Impurity in Ceftriaxone Sodium Preparation for Injection in Determining Compatibility with Calcium-Containing Solutions.

    Science.gov (United States)

    Tange, Mio; Yoshida, Miyako; Nakai, Yuka; Uchida, Takahiro

    2016-01-01

    Ceftriaxone sodium preparation for injection is known to form insoluble microparticles with calcium. The purpose of this study was to evaluate the role of an impurity in the ceftriaxone sodium preparation on this incompatibility. Firstly, using HPLC, two impurities were identified in the ceftriaxone sodium solution. The major impurity (impurity 1) was identified as tetrahydro-2-methyl-3-thioxo-1,2,4-triazine-5,6-dione by LC/MS. Secondly, the role played by this impurity in the incompatibility with calcium was examined. Using seven different ceftriaxone preparations for injection, the effect of adding impurity 1 to mixed solutions of ceftriaxone sodium and calcium chloride on the appearance of insoluble microparticles, was examined using a light obscuration particle counter. Although incompatibility was not completely suppressed by the addition of impurity 1, the number of insoluble microparticles formed with calcium chloride solution was decreased in proportion to the concentration of impurity 1, and the concentration of calcium ion decreased as the concentration of added impurity 1 increased. These results show that impurity 1 plays a concentration-dependent role in incompatibility between ceftriaxone sodium preparation for injection and calcium-containing solutions.

  11. Defluoridation of water using calcium aluminate material

    Czech Academy of Sciences Publication Activity Database

    Sakhare, N.; Lunge, S.; Rayalu, S.; Bakardjieva, Snejana; Šubrt, Jan; Devotta, S.; Labhsetwar, N.

    2012-01-01

    Roč. 203, SEPTEMBER (2012), s. 406-414 ISSN 1385-8947 R&D Projects: GA MŠk LC523 Institutional support: RVO:61388980 Keywords : Defluoridation * Fluorosis * Adsorption * Fluoride removal * Calcium aluminate Subject RIV: CA - Inorganic Chemistry Impact factor: 3.473, year: 2012

  12. Analysis of the factors which have an influence on the reduction of residuary strengths due to alkaline solution in the interstitial mortars of concretes with aluminous cement Assessment of the risk limits in the case of roof beams

    Directory of Open Access Journals (Sweden)

    Goma Ginesta, Ferrán

    1995-06-01

    Full Text Available The scarce references which exist in the bibliography on this subject and their vagueness on the factors which have an influence on the reduction of the strength of aluminous cement concrete due to the effect of alkalinity, have not yet allowed the limits to be clearly seen which could give rise to a situation of risk in the structural elements due to this cause. A study is presented which endeavors to measure the quantitative influence of different parameters of the same or of a similar conditions to those presented in the usual types of concrete in existing beams with aluminous cement characteristic of our market. The parameters tested were: the influence of the concentration of free ions OH-, the class of alkaline ion, the temperature, the time, the presence or absence of CO2, the degree of conversion, the physical parameters, porosities, densities, etc., and the phases existing were determined by XRD, DTA and TG before and after the alkaline action. From the results obtained in numerous series of Rilem mortars and micro-mortars, it is possible to see the possibility of establishing the setting of parameters which define areas without risk.

    Las escasas referencias que existen en la bibliografía sobre este tema, y su identificación sobre los factores que tienen influencia sobre la disminución de resistencias en el hormigón de cemento aluminoso por efecto de la alcalinidad, no ha permitido aún ver claramente los limites que pueden dar lugar a una situación de riesgo en los elementos estructurales por esta causa. Se presenta un estudio que trata de medir la influencia cuantitativa de diferentes parámetros, con la misma o semejante magnitud que se presentan en los tipos usuales de hormigones de vigas existentes con cemento aluminoso propio de nuestro mercado. Los parámetros ensayados han sido: la influencia de la concentración de iones OH- libres, la clase de ion alcalino, la temperatura, el

  13. Determination of Sandoz Black Aluminum Coloring Dye Olive Aluminum Coloring Dye and Sodium Dichromate Aluminum Sealing Solutions by UV-Visible Spectrophotometry

    National Research Council Canada - National Science Library

    Sopok, Samuel

    1992-01-01

    The chemical literature lacks an acceptable method to determine and adequately control Sandoz black aluminum coloring dye, olive aluminum coloring dye, and sodium dichromate aluminum sealing solutions...

  14. Inactivation of heat adapted and chlorine adapted Listeria monocytogenes ATCC 7644 on tomatoes using sodium dodecyl sulphate, levulinic acid and sodium hypochlorite solution

    Directory of Open Access Journals (Sweden)

    Oluwatosin Ademola Ijabadeniyi

    2017-04-01

    Full Text Available The effectiveness of sodium dodecyl sulphate (SDS, sodium hypochlorite solution and levulinic acid in reducing the survival of heat adapted and chlorine adapted Listeria monocytogenes ATCC 7644 was evaluated. The results against heat adapted L. monocytognes revealed that sodium hypochlorite solution was the least effective, achieving log reduction of 2.75, 2.94 and 3.97 log colony forming unit (CFU/mL for 1, 3 and 5 minutes, respectively. SDS was able to achieve 8 log reduction for both heat adapted and chlorine adapted bacteria. When used against chlorine adapted L. monocytogenes sodium hypochlorite solution achieved log reduction of 2.76, 2.93 and 3.65 log CFU/mL for 1, 3 and 5 minutes, respectively. Using levulinic acid on heat adapted bacteria achieved log reduction of 3.07, 2.78 and 4.97 log CFU/mL for 1, 3, 5 minutes, respectively. On chlorine adapted bacteria levulinic acid achieved log reduction of 2.77, 3.07 and 5.21 log CFU/mL for 1, 3 and 5 minutes, respectively. Using a mixture of 0.05% SDS and 0.5% levulinic acid on heat adapted bacteria achieved log reduction of 3.13, 3.32 and 4.79 log CFU/mL for 1, 3 and 5 minutes while on chlorine adapted bacteria it achieved 3.20, 3.33 and 5.66 log CFU/mL, respectively. Increasing contact time also increased log reduction for both test pathogens. A storage period of up to 72 hours resulted in progressive log reduction for both test pathogens. Results also revealed that there was a significant difference (P≤0.05 among contact times, storage times and sanitizers. Findings from this study can be used to select suitable sanitizers and contact times for heat and chlorine adapted L. monocytogenes in the fresh produce industry.

  15. Inactivation of Heat Adapted and Chlorine AdaptedListeria MonocytogenesATCC 7644 on Tomatoes Using Sodium Dodecyl Sulphate, Levulinic Acid and Sodium Hypochlorite Solution.

    Science.gov (United States)

    Ijabadeniyi, Oluwatosin Ademola; Mnyandu, Elizabeth

    2017-04-13

    The effectiveness of sodium dodecyl sulphate (SDS), sodium hypochlorite solution and levulinic acid in reducing the survival of heat adapted and chlorine adapted Listeria monocytogenes ATCC 7644 was evaluated. The results against heat adapted L. monocytognes revealed that sodium hypochlorite solution was the least effective, achieving log reduction of 2.75, 2.94 and 3.97 log colony forming unit (CFU)/mL for 1, 3 and 5 minutes, respectively. SDS was able to achieve 8 log reduction for both heat adapted and chlorine adapted bacteria. When used against chlorine adapted L. monocytogenes sodium hypochlorite solution achieved log reduction of 2.76, 2.93 and 3.65 log CFU/mL for 1, 3 and 5 minutes, respectively. Using levulinic acid on heat adapted bacteria achieved log reduction of 3.07, 2.78 and 4.97 log CFU/mL for 1, 3, 5 minutes, respectively. On chlorine adapted bacteria levulinic acid achieved log reduction of 2.77, 3.07 and 5.21 log CFU/mL for 1, 3 and 5 minutes, respectively. Using a mixture of 0.05% SDS and 0.5% levulinic acid on heat adapted bacteria achieved log reduction of 3.13, 3.32 and 4.79 log CFU/mL for 1, 3 and 5 minutes while on chlorine adapted bacteria it achieved 3.20, 3.33 and 5.66 log CFU/mL, respectively. Increasing contact time also increased log reduction for both test pathogens. A storage period of up to 72 hours resulted in progressive log reduction for both test pathogens. Results also revealed that there was a significant difference (P≤0.05) among contact times, storage times and sanitizers. Findings from this study can be used to select suitable sanitizers and contact times for heat and chlorine adapted L. monocytogenes in the fresh produce industry.

  16. Evaluation of bioactivity in vitro of endodontic calcium aluminate cement

    International Nuclear Information System (INIS)

    Oliveira, I.R.; Andrade, T.L.; Santos, G.L.; Pandolfelli, V.C.

    2011-01-01

    Bioactivity is referred to as the capacity of a material to develop a stable bond with living tissue via the deposition of hydroxyapatite. Materials which exhibit this property can be used to repair diseased or damaged bone tissue and can be designed to remain in situ indefinitely. An indication of bioactivity can be obtained by the formation of a hydroxyapatite layer on the surface of a substrate in simulated body fluids (SBF) in vitro. Therefore, set samples of calcium aluminate endodontic cement were maintained in contact with SBF solutions (Kokubo and Rigo) and their surfaces were later evaluated by means of SEM, EDX and DRX. Measurements of pH and ionic conductivity were also carried out for SBF solutions in contact with set samples of endodontic cement. The ideal conditions of precipitation were obtained in SBF Rigo been observed a surface layer with spherical morphology characteristic of stoichiometric hydroxyapatite.(author)

  17. Extraction of heavy metals from MSWI fly ash using hydrochloric acid and sodium chloride solution.

    Science.gov (United States)

    Weibel, Gisela; Eggenberger, Urs; Kulik, Dmitrii A; Hummel, Wolfgang; Schlumberger, Stefan; Klink, Waldemar; Fisch, Martin; Mäder, Urs K

    2018-03-17

    Fly ash from municipal solid waste incineration contains a large potential for recyclable metals such as Zn, Pb, Cu and Cd. The Swiss Waste Ordinance prescribes the treatment of fly ash and recovery of metals to be implemented by 2021. More than 60% of the fly ash in Switzerland is acid leached according to the FLUWA process, which provides the basis for metal recovery. The investigation and optimization of the FLUWA process is of increasing interest and an industrial solution for direct metal recovery within Switzerland is in development. With this work, a detailed laboratory study on different filter cakes from fly ash leaching using HCl 5% (represents the FLUWA process) and concentrated sodium chloride solution (300 g/L) is described. This two-step leaching of fly ash is an efficient combination for the mobilization of a high percentage of heavy metals from fly ash (Pb, Cd ≥ 90% and Cu, Zn 70-80%). The depletion of these metals is mainly due to a combination of redox reaction and metal-chloride-complex formation. The results indicate a way forward for an improved metal depletion and recovery from fly ash that has potential for application at industrial scale. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. Sequence of stannous and sodium fluoride solutions to prevent enamel erosion.

    Science.gov (United States)

    O'Toole, Saoirse; Mistry, Miten; Mutahar, Mahdi; Moazzez, Rebecca; Bartlett, David

    2015-12-01

    Investigate the timing of stannous (SnF2) and sodium fluoride (NaF) application with and without salivary pellicle to prevent enamel erosion. Human buccal molar enamel samples (n=120, REC ref 12/LO/1836) were randomly assigned to three groups testing SnF2 and NaF basic fluoride formulation and commercial mouthrinses with and without the presence of human saliva. Samples were randomly allocated to 2 subgroups: immersion in either fluoride for 1 min either before or after citric acid immersion (0.3%, pH 3.2, 10 min), and the cycle repeated 5 times. For human saliva group, samples were immersed in 80 ml of natural saliva for 24 h prior to the experiment. Analysis was done using non-contacting profilometry and microhardness change. Data were not normal and were log transformed. A linear model tested statistical differences between the groups. SnF2 application before erosion statistically reduced step height compared to application after erosion for all groups (solutions: 6.5 μm (±1.2), 7.5 μm (±0.8); p=0.01, mouthrinses: 3.2 μm (±0.6), 4.2 μm (±0.7); perosion increased step height compared to application after, but this was only statistically significant for the saliva group (before: 5.6 μm (±0.3) and after: 4.9 μm (±0.3); p=0.023). Presence of saliva increased microhardness change (perosion and when NaF was applied after erosion (SnF2: 156.6KHN (±32.8), 123KHN (±20.1); p=0.02. NaF: 119.5KHN (±33.5), 218KHN (±24.9), before, and after respectively). SnF2 reduced step height formation overall when compared to NaF, but particularly when applied before citric acid immersion. In contrast, NaF reduced step height when applied after citric acid immersion, but only in the presence of saliva. Stannous fluoride can be recommended over sodium fluoride to patients at risk of dental erosion and is optimally applied before erosion occurs. If sodium fluoride is to be used in the presence of saliva it is optimally applied after erosion has occurred. Copyright © 2015

  19. A prospective randomized blinded comparison of sodium phosphate and polyethylene glycol-electrolyte solution for safe bowel cleansing

    NARCIS (Netherlands)

    Mathus-Vliegen, E. M. H.; Kemble, U. M.

    2006-01-01

    BACKGROUND: Polyethylene glycol-electrolyte solution (PEG-ELS) is routinely prescribed for bowel cleansing. Sodium phosphate (NaP) may be an effective but potentially hazardous alternative. AIM: To investigate the safety of prescription of either agent, without being informed of the patient's

  20. Precipitation of UO2 in sodium carbonate solutions by electrolytic hydrogen and catalyzed by Ni-Raney - Bibliography

    International Nuclear Information System (INIS)

    Pottier, P.

    1958-01-01

    This report proposes abstracts and short versions of a set of documents (studies, patents) dealing with the precipitation of uranium (notably in its oxide form, UO 2 ) in solutions of sodium carbonate. The main objective is to identify the interest of a chemical reduction by electrolytic hydrogen. The author makes a distinction between the most relevant documents and those relatively relevant ones [fr

  1. Radiolysis of aqueous solutions of sodium salt of adipic acid bis-(2,4,6-triiodo-3-carboxyanilide). [Gamma rays

    Energy Technology Data Exchange (ETDEWEB)

    Kharlamov, V.T.; Pikaev, A.K.; Shubnyakova, L.P.; Sysoeva, K.S.

    1975-07-01

    The ..gamma.. radiolysis of aqueous solutions of the sodium salt of adipic acid bis-(2,4,6-triiodo-3-carboxyanilide) was studied. The radiation-chemical decomposition yields of this compound and the formation of iodide ions under various conditions were measured. (auth)

  2. Influence of Sodium Bisulfite and Lithium Bromide Solutions on the Shape Fixation of Camel Guard Hairs in Slenderization Process

    OpenAIRE

    Xiao, Xueliang; Hu, Jinlian

    2016-01-01

    Outstanding performance of natural camel hair has attracted much attention on the effective use of such specialty fiber to apparel textiles. In this paper, sodium bisulfide (SB) and lithium bromide (LB) solutions were used to process the camel guard hair before its slenderization. It is found that camel guard hair processed by SB solution shows the highest breaking elongation (~140%) due to the breakage of disulfide bonds (reflected by Raman spectra). LB ions result in the disruption of hair ...

  3. Kidney injury after sodium phosphate solution beyond the acute renal failure.

    Science.gov (United States)

    Fernández-Juárez, Gema; Parejo, Leticia; Villacorta, Javier; Tato, Ana; Cazar, Ramiro; Guerrero, Carmen; Marin, Isabel Martinez; Ocaña, Javier; Mendez-Abreu, Angel; López, Katia; Gruss, Enrique; Gallego, Eduardo

    2016-01-01

    Screening colonoscopy with polipectomy reduces colonorectal cancer incidence and mortality. An adequate bowel cleansing is one of the keys to achieving best results with this technique. Oral sodium phosphate solution (OSP) had a widespread use in the 90s decade. Its efficacy was similar to polyethylene glycol (PEG) solution, but with less cost and convenient administration. Series of patients with acute renal failure due to OSP use have been reported. However, large cohorts of patients found no difference in the incidence of renal damage between these two solutions. From 2006 to 2009 we identified twelve cases of phosphate nephropathy after colonoscopy prepared with OSP. All patients were followed up to six months. All patients had received just a single dose. We analyzed 12 cases with phosphate nephropathy; three patients debuted with AKI and nine patients had chronic renal injury. Four cases were confirmed with renal biopsy. One patient with AKI needed hemodialysis at diagnosis without subsequent recovery. Two patients (both with chronic damage) fully recovered their previous renal function. The remaining patients (nine) had an average loss of estimated glomerular filtration rate of 24ml/min/1.73m(2). The use of OSP can lead to both acute and chronic renal damage. However, chronic injury was the most common pattern. Both forms of presentation imply a significant and irreversible loss of renal function. Further studies analyzing renal damage secondary to bowel cleaning should consider these two different patterns of injury. Copyright © 2016 Sociedad Española de Nefrología. Published by Elsevier España, S.L.U. All rights reserved.

  4. Correction of Hemodynamics with Hypertonic Sodium Chloride Solution in Critical Conditions

    Directory of Open Access Journals (Sweden)

    P. S. Zhbannikov

    2007-01-01

    Full Text Available Objective: to assess the capabilities of small-volume hypertonic infusion in the context of early goal-directed therapy for critical conditions in surgical patients.Subjects and methods. Twenty-nine patients (SAPS II 47.5±6.81 scores operated on for generalized peritonitis (n=24 or severe concomitant injury with damages to chest and/or abdominal organs (n=5 who had the clinical and laboratory signs of a systemic inflammatory reaction were intravenously injected 4 ml/kg of 7.5% of hypertonic sodium chloride solution (HS and colloidal solution, followed by infusion and, if indicated, inotropic maintenance of hemodynamics for 6 hours in order to achieve the goal vales of mean blood pressure (BP, central venous pressure (CVP, central venous blood oxygen saturation (ScvO2, and diuresis. Plasma concentrations of sodium, chlorine, and lactate, acid-base balance, and osmotic blood pressure were monitored.Results. The patients were found to have infusion therapy-refractory critical arterial hypotension, low ScvO2, and oliguria before small-volume circulation maintenance. In all the patients, HS infusion originally caused a rapid rise in BP up to the goal value, with its further colloid infusion maintenance requiring additional dopamine infusion in 12 patients and red blood cell transfusion in 3. This could stabilize over 6 hours BP at the required level in 25 patients, in 9 of whom CVP only approximated the goal value. All the patients were found to have a significant increase in ScvO2 up to an average of 68% in response to HP infusion after 30—60 minutes; in 14 out of them ScvO2 exceeded 70%. By hour 6, ScvO2 stabilized at its goal level in 23 (79% examinees. Administration of HS caused a significantly increased diuresis. In patients with recovered renal function, the observed hypernatremia, hyperchloremia with hyperchloremic acidosis were transient.Conclusion. The results of the study show it possible to include small-volume hypertonic infusion at

  5. Evaporation of sessile droplets of dilute aqueous solutions containing sodium n-alkylates from polymer surfaces: influences of alkyl length and concentration of solute.

    Science.gov (United States)

    Kim, Jung-Hoon; Ahn, Sung Il; Kim, Jae Hyun; Kim, Jong Soo; Cho, Kilwon; Jung, Jin Chul; Chang, Taihyun; Ree, Moonhor; Zin, Wang-Cheol

    2008-10-21

    The evaporation of sessile droplets placed on polymer surfaces was studied by microscopic observation of the changes in shape of aqueous solution droplets in which the alkyl lengths and the initial concentrations of sodium n-alkylates were varied. Although the initial contact angles of the droplets were not significantly different, the evaporation process varied significantly with the alkyl length of the sodium n-alkylate employed. For the sodium dodecanoate (C 12), showing the highest surface activity, the concentration was found to have a significant effect on the evaporation process of the droplets. In the evaporation of water droplets, variations in the three distinct stages were caused by the different concentration of solutes distributed near or at the air/water interface. It is revealed that the concentration of droplet solute near the air/water interface requires not only solvent evaporation but also some affinity of the solute for the interface. The initial C 12 concentration-dependence of the evaporation of C 12 solution droplets is discussed with particular emphasis on the sudden spreading or sudden contraction of the contact area near the end of evaporation. It is suggested that the cluster formation by C 12 molecules at the air/liquid interface during the evaporation causes Marangoni instability in an evaporating droplet, and the clusters are expected to move dynamically, depending on the droplet concentration of C 12, from the droplet center to the contact line and vice versa, showing Marangoni flow along the air/water interface.

  6. Effectiveness of Chlorinated Water, Sodium Hypochlorite, Sodium ...

    African Journals Online (AJOL)

    This study evaluated the efficacy of chlorinated water, sodium hypochlorite solution, sodium chloride solution and sterile distilled water in eliminating pathogenic bacteria on the surfaces of raw vegetables. Lettuce vegetables were dipped in different concentrations of chlorinated water, sodium hypochlorite solution, sodium ...

  7. Effect of Anionic Surfactant on the Thermo Acoustical Properties of Sodium Dodecyl Sulphate in Polyvinyl Alcohol Solution by Ultrasonic Method

    Directory of Open Access Journals (Sweden)

    S. Ravichandran

    2011-01-01

    Full Text Available The interaction of sodium dodecyl sulphate (SDS / poly(vinyl alcohol (PVA solution was studied by ultrasonic velocity measurements. Ultrasonic velocity, density, viscosity in mixtures of sodium dodecyl sulphate in polyvinyl alcohol was measured over the entire range of composition. From the experimental data, other related thermodynamic parameters, viz., adiabatic compressibility, intermolecular free length, surface tension, relative association, relaxation time, absorption coefficient and internal pressure were calculated. Formations of rods interfere with velocity of ultrasonic waves. Hence the ultrasonic velocity decreases with concentration. These results were interpreted in terms of polymer-surfactant complex reactions.

  8. Decreasing Molybdenum Content in U3O8 of Bandar Abbas Uranium Plant by Stripping, Acidic Sodium Chloride Solution

    International Nuclear Information System (INIS)

    Moghaddam Fard, Z.; Vartanian, S.; Pur Hoseini, Zh.; Pakizvand, N.; Ghadiri, A.

    2010-01-01

    Molybdenum content in U 3 O 8 is one of the difficulties in uranium oxide production plant, as contaminant. Several methods have been proposed for reducing Molybdenum from U 3 O 8 process circuit. As a few changes in the process circuit of Bandar Abbas Uranium Plant were aimed, the loaded organic solvent containing uranium and molybdenum were stripped with acidic sodium chloride solution. The current 10% Sodium carbonate solution was substituted by 1.2 M NaCl + 0.02 M H 2 SO 4 as a new strip solution. This method decreases Mo contents from 96.94 to 4.17 percent. With the proceeding precipitation and the calcination stages, the Molybdenum amounts in U 3 O 8 was reduced from 6.4 to 0.14 percent.

  9. The aluminizing in powder technology of AISI 304 steel

    Science.gov (United States)

    Băitanu, D. B.; Găluşcă, D. G.; Achiţei, D. C.; Minciună, M. G.; Bakri Abdullah, Mohd Mustafa Al

    2016-06-01

    The paper presents a study about the aluminizing treatments applied to AISI 304 stainless steel, with the purpose to improve the corrosion resistance. The aluminizing is realized in a powder medium, composed by aluminium powder (with 99.95% purity), aluminium oxide Al2O3 and ammonium chloride NH4Cl. The structural characterization was made by scanning electronic microscopy to highlight the structure of layer after aluminizing, at different magnitudes.

  10. Drying process of sodium alginate edible films forming solutions studied by LF NMR.

    Science.gov (United States)

    Xiao, Qian

    2018-06-01

    The dynamics of water in sodium alginate film-forming solutions during drying were investigated by low-field nuclear magnetic resonance. At the beginning of drying, three transverse relaxation times at around 1.74, 28.48 and 305.38 ms were assigned to the tightly bound, moderately bound, and free water, respectively. Moreover, the free water was evaporated, followed by the formation of water cluster in the entangled alginate chains network as the drying process continued (beyond 840 min of drying time). Towards the third stage of drying process, water clusters in alginate samples was disappeared, resulting that loosely bonded waters were constrained within the weak-gel network. The observed three relaxation times revealed the multi-exponential relaxation behavior of water in alginate, which indicated that this polymer exhibited spatial heterogeneity during drying. On the basis of diffusive exchange theory, the dimension range of alginate network decreased from 1.94-23.99 to 1.83-6.62 µm as the alginate films solidified. Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. Cations extraction of sandy-clay soils from cavado valley, portugal, using sodium salts solutions

    Directory of Open Access Journals (Sweden)

    Silva João Eudes da

    2002-01-01

    Full Text Available Cases of contamination by metals in the water wells of the Cavado Valley in north-west Portugal can be attributed to the heavy leaching of clay soils due to an excess of nitrogen resulting from the intensive use of fertilisers in agricultural areas. This work focuses on the natural weathering characteristics of soils, particularly the clay material, through the study of samples collected near the River Cavado. Samples taken from various sites, after physico-chemical characterisation, were subjected to clay dissolution tests, using sodium salts of different ionic forces, to detect the relationship between certain physico-chemical parameters of water, such as pH, nitrate, chloride and sulphate content, in the dissolution of clay and the subsequent extraction of such cations as Al, Fe and K. In acidic sandy clay soils, the mineralogical composition of which was characterised by a predominance of quartz, micas, kaolinite and K-feldspars, decreases of the clay material/water pH ratio increases dissolution of the micaceous and K-feldspars phases. The presence of nitrates in the aqueous solution apparently advanced the extraction of all three cations Al, Fe and K. The specific surface area of the clay material showed a significant correlation with the main kinetic parameters of cation extraction.

  12. Kinetics and mechanism of sphalerite leaching by sodium nitrate in sulphuric acid solution

    Directory of Open Access Journals (Sweden)

    Sokić M.

    2012-01-01

    Full Text Available Interest for application of hydrometallurgical processes in a processing of complex sulphide ores and concentrates has increased in recent years. Their application provides better metal recoveries and reduced emission of gaseous and toxic ageneses in the environment. The kinetics and mechanism of sphalerite leaching from complex sulphide concentrate with sulphuric acid and sodium nitrate solution at standard conditions was presented in this paper. The influences of temperature and time on the leaching degree of zinc were investigated and kinetic analysis of the process was accomplished. With temperature increasing from 60 to 90°C, the zinc leaching increased from 25.23% to 71.66% after 2 hours, i.e. from 59.40% to 99.83% after 4 hours. The selected kinetic model indicated that the diffusion through the product layer was the rate-controlling step during the sphalerite leaching. The activation energy was determined to be 55 kJ/mol in the temperature range 60-90°C. XRD, light microscopy and SEM/EDX analyses of the complex concentrate and leach residue confirmed formation of elemental sulphur and diffusion-controlled leaching mechanism.

  13. Postharvest decay reduction of fig fruit (Ficus carica) by hot water sodium carbonate solutions dip.

    Science.gov (United States)

    Molinu, M G; Venditti, T; Dore, A; D'Hallewin, G; Serusi, A; Del Caro, A; Agabbio, M

    2006-01-01

    Treatments as hot water dips or high temperature conditioning have been proven to be effective to control postharvest decay on various horticultural crops. These treatments reduce chilling injury and rot losses without causing detrimental effects on fruit firmness, flavour, taste or peel appearance. These technologies, aimed to control postharvest pathogens, can be easily matched with the use of "Generally Recognized as Safe" (G.R.A.S.) compounds and employed alternatively to pesticides, known to be harmful to health and environment. In this respect we studied the combined effect of sodium carbonate (SC) and hot water on the storability of black fig fruit cultivar 'Niedda Longa' of Sardinian germplasm. Second crop fig fruit, harvested in the middle of September, was dipped for one minute in water solutions containing 0, 0.05, 0.5, and 1% (w/v) of SC at 25 or 60 degrees C and then stored at 5 degrees C and 90% relative humidity (RH) for two weeks. After one and two weeks of storage decay, weight loss were monitored and visual assessment was scored. Treatments with hot solutions were more effective in controlling decay compared to cold ones and the best results were achieved with 0.5% of SC at 60 degrees C. This combination reduced the decay rate from 26% (control) to 0% after 1 week and from 50% to 14% after two weeks of storage, respectively. Lower or higher SC concentrations applied at 60 degrees C were less effective and, after two weeks of storage, decay percentages were 38 and 43.6%, respectively. Water dip at 60 degrees C did not affect the weight loss as compared to dips at 25 degrees C either after one or two weeks of storage. At the same time, a significant reduction was found only with 1% of SC at 25 degrees C. The fruit treated with 0.5% of SC at 60 degrees C also had the best visual assessment up to two weeks of storage.

  14. Halting of the calcium aluminate cement hydration process

    International Nuclear Information System (INIS)

    Luz, A.P.; Borba, N.Z; Pandolfelli, V.C.

    2011-01-01

    The calcium aluminate cement reactions with water lead to the anhydrous phases dissolution resulting a saturated solution, followed by nucleation and crystal growth of the hydrate compounds. This is a dynamic process, therefore, it is necessary to use suitable methods to halt the hydration in order to study the phase transformations kinetics of such materials. In this work two methods are evaluated: use of acetone and microwave drying, aiming to withdraw the free water and inhibit further reactions. X ray diffraction and thermogravimetric tests were used to quantify the phases generated in the cement samples which were kept at 37 deg C for 1 to 15 days. The advantages and disadvantages of those procedures are presented and discussed. The use of microwave to halt the hydration process seems to be effective to withdraw the cement free water, and it can further be used in researches of the refractory castables area, endodontic cements, etc. (author)

  15. Surface properties of aqueous amino acid solutions II. Leucine-leucine hydrochloride and leucine-sodium leucinate mixtures.

    Science.gov (United States)

    Matubayasi, Norihiro; Matsuyama, Shohei; Akizuki, Ryosuke

    2005-08-15

    To understand the distinction between the effects of zwitterionic, anionic, and cationic l-leucine upon adsorption and lateral interactions at air/water surface, the surface tensions of aqueous solutions of l-leucine-l-leucine hydrochloride and l-leucine-sodium l-leucinate mixtures were measured as a function of concentration and composition at 25 degrees C. The surface activity decreases in the order l-leucine >l-leucine hydrochloride > sodium l-leucinate. Both l-leucine hydrochloride and sodium l-leucinate form gaseous adsorbed films through the experimentally accessible concentration range, while the adsorbed film of zwitterionic l-leucine shows a transition between gaseous and expanded film.

  16. Effect of temperature on solvation behaviour of diclofenac sodium salt in aqueous glycine and L-proline solutions

    International Nuclear Information System (INIS)

    Ryshetti, Suresh; Gardas, Ramesh L; Tangeda, Savitha Jyostna

    2015-01-01

    Highlights: • Solvation behaviour of diclofenac drug studied in aqueous solutions. • Density and speed of sound of drug in aq. glycine and L-proline are measured. • Hydrophobic nature of diclofenac sodium salt is studied. • Effect of temperature on solvation of diclofenac sodium salt is analysed. - Abstract: Apparent molar volume (V 2,ϕ ) and apparent molar isentropic compressibility (K s,2,ϕ ) of diclofenac sodium salt (DSS) drug within the concentration range of (0.001 to 0.008) mol · kg −1 in (0.01, 0.03 and 0.05) mol · kg −1 aqueous glycine and L-proline solutions are computed from the experimental density (ρ) and speed of sound (u) values at T = (293.15 to 313.15) K and atmospheric pressure. Derived parameters such as partial molar properties, transfer partial molar properties, hydration numbers and Hepler’s constant are computed from the data of V 2,ϕ and K s,2,ϕ . These parameters have been used to understand the effect of temperature on interactions between DSS drug and aqueous glycine/L-proline solution. Furthermore, the structure making and breaking ability of DSS drug in probed solutions are analysed at experimental conditions

  17. Improved water and sodium absorption from oral rehydration solutions based on rice syrup in a rat model of osmotic diarrhea.

    Science.gov (United States)

    Wapnir, R A; Litov, R E; Zdanowicz, M M; Lifshitz, F

    1991-04-01

    Rice syrup solids, rice protein, and casein hydrolysate were added to experimental oral rehydration solutions in various combinations and tested in a rat intestinal perfusion system. Chronic osmotic diarrhea was induced in juvenile rats by supplying the cathartic agents, magnesium citrate and phenolphthalein, in their drinking water for 1 week. The experimental oral rehydration solutions were compared with standard oral rehydration solutions containing 20 gm/L or 30 gm/L of glucose and with each other to determine if there were significant differences in net water, sodium, or potassium absorption. An oral rehydration solution containing 30 gm/L of rice syrup solids had a net water absorption rate significantly higher than that of the standard 20 gm/L glucose-based oral rehydration solution (2.1 +/- 0.62 versus 1.5 +/- 0.48 microliters/[min x cm], p less than 0.05). Casein hydrolysate did not significantly affect net water absorption. However, combinations of 30 gm/L rice syrup solids and 5 gm/L casein hydrolysate significantly increased (p less than 0.05) net sodium and potassium absorption compared with the 20 gm/L glucose-based oral rehydration solution but not versus rice syrup solids alone. Oral rehydration solutions containing 30 gm/L rice syrup solids plus 5 gm/L rice protein, and 30 gm/L rice syrup solids plus 5 gm/L casein hydrolysate, had net water absorption rates significantly higher than the rate of a 30 gm/L glucose-based oral rehydration solution (2.5 +/- 0.36 and 2.4 +/- 0.38, respectively, versus 0.87 +/- 0.40 microliters/[min x cm], p less than 0.05). Rice protein and casein hydrolysate, however, did not significantly affect net water, sodium, or potassium absorption when added to rice protein glucose-based oral rehydration solutions. An inverse correlation between osmolality and net water absorption was observed (r = -0.653, p less than 0.02). The data suggest that substitution of rice syrup solids for glucose in oral rehydration solutions will

  18. Calcium aluminate cement hydration in a high alkalinity environment

    Directory of Open Access Journals (Sweden)

    Palomo, Á.

    2009-03-01

    Full Text Available The present paper forms part of a broader research project that aims primarily to devise new cementitious products via the alkali activation of silico-aluminous materials. This work addresses the possibility of using small percentages of calcium aluminate cement (CAC as a source of reactive aluminium. For this reason, a preliminary review was needed of the behaviour of CACs in highly alkaline media (2, 8 and 12M NaOH solutions. Two, 28- and 180-day mechanical strength was determined and the reaction products were characterized with XRD and FTIR. The water-hydrated CAC was used as the control.The results obtained showed that CAC hardening took place much more slowly in highly alkaline media than in water. Nonetheless, the 28-day compressive strength obtained, ≥80MPa. As main reaction products, to ambient temperature and from the two days of cured, cubic aluminate C3AH6, and AH3 polymorphs are formed, instead of the usual hexagonal aluminatos (CAH10 and C2AH8 that are formed in the normal hydrate with water.El presente trabajo forma parte de una amplia investigación cuyo objetivo principal es el de elaborar nuevos materiales con propiedades cementantes mediante la activación alcalina de materiales de naturaleza silito-aluminosa. En estos estudios se contempla la posibilidad de utilizar pequeños porcentajes de cemento de aluminato de calcio (CAC como fuente de aluminio reactivo. Por ello inicialmente se ha estudiado el comportamiento de los CAC en medios fuertemente alcalinos (disoluciones de NaOH 2M, 8M y 12M. Se determinaron las resistencias mecánicas a 2, 28 y 180 días y se realizó una caracterización de los productos de reacción formados por DRX, FTIR. Como sistema de referencia se consideró la hidratación del CAC con agua.Los resultados obtenidos muestran que en medios fuertemente alcalinos se retrasan los procesos de rápido endurecimiento de CAC con agua. No obstante a 28 días se obtienen valores de resistencia a compresión

  19. Removal of Hg(II) from aqueous solution using sodium humate as heavy metal capturing agent.

    Science.gov (United States)

    Wang, Shixiang; Liu, Yong; Fan, Qin; Zhou, Anlan; Fan, Lu; Mu, Yulan

    2016-12-01

    An environmental friendly and economic natural biopolymer-sodium humate (HA-Na) was used to capture Hg(II) from aqueous solutions, and the trapped Hg(II) (HA-Na-Hg) was then removed by aluminium coagulation. The best Hg(II) capturing performance (90.60%) was observed under the following conditions: initial pH of 7.0, coagulation pH of 6.0, HA-Na dosage of 5.0 g L -1 , Al 2 (SO 4 ) 3 .18H 2 O dosage of 4.0 g L -1 , initial Hg(II) concentration of 50 mg L -1 and capturing time of 30 min. The HA-Na compositions with the molecular weight beyond 70 kDa showed the most intense affinity toward Hg(II). The results showed that the reaction equilibrium was achieved within 10 min (pH 7.0), and could be well fitted by the pseudo-second-order kinetics model. The capturing process could be well described by the Langmuir isotherm model and the maximum capturing capacity of Hg(II) was high up to 9.80 mg g -1 at 298 K (pH 7.0). The Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analysis showed that the redox reaction between Hg(II) and HA-Na and the coordination reaction of carboxyl and hydroxy groups of HA-Na with Hg(II) were responsible for Hg(II) removal. The successive regeneration experiment showed that the capturing efficiency of humates for Hg(II) was maintained at about 51% after five capture-regeneration recycles.

  20. Reactions between rocks and the hydroxides of calcium, sodium and potassium: progress report no. 1

    International Nuclear Information System (INIS)

    Van Aardt, J.H.P.; Visser, S.

    1982-01-01

    The reaction between the hydroxides of calcium, sodium and potassium, and clay minerals, feldspars, and some rocks (aggregates for use in concrete) was investigated. The reaction products were examined by means of x-ray diffraction and chemical analysis. The solid reaction products identified were hydrated calcium silicates,hydrated calcium aluminates, and hydrated calcium alumina silicates. It was found that, in the presence of water, calcium hydroxide liberated alkali into solution if the rocks and minerals contained alkali metals in their structure. Two crystalline hydrated sodium calcium silicates (12A and 16A) were prepared in the system Na 2 O-CaO-SiO 2 -H 2 O at 80 degrees Celsius. The one compound (12A) was also observed when sodium hydroxide plus calcium hydroxide and water reacted with silica- or silicate-containing rocks

  1. A comparison study between sodium dodecyl sulfate and sodium dodecyl sulfonate with respect to the thermodynamic properties, micellization, and interaction with poly(ethylene glycol) in aqueous solutions

    International Nuclear Information System (INIS)

    Sadeghi, Rahmat; Shahabi, Somayyeh

    2011-01-01

    Graphical abstract: Apparent molar volume against molality: o, ·, and Δ, respectively in water, (1 and 4) wt% PEG solution at 293.15 K; x, Δ, and lozenge, respectively in water, (1 and 4) wt% PEG solution at 313.15 K. Research highlights: → C 12 H 25 SO 3 Na(SDSn) was seen to interact with PEG more weakly than C 12 H 25 SO 4 Na(SDS). → The constraints on molecular mobility of SDS micelles are larger than those of SDSn. → Entropy change on micellization for SDSn is larger than those for SDS. → Micelle formation of SDS is less endothermic and more spontaneous than that of SDSn. → Micelles of SDS have smaller aggregation number than that of SDSn. - Abstract: The density, sound velocity, and conductivity measurements were performed on aqueous solutions of sodium dodecyl sulfate (C 12 H 25 SO 4 Na) or sodium dodecyl sulfonate (C 12 H 25 SO 3 Na) in the absence and presence of poly(ethylene glycol) (PEG) at different temperatures. Changes in the apparent molar volumes and isentropic compressibilities upon micellization were derived using a pseudophase-transition approach and the infinite dilution apparent molar properties of the monomer and micellar form of C 12 H 25 SO 4 Na and C 12 H 25 SO 3 Na were determined. Variations of the critical micelle concentrations (CMCs) of both surfactants in the solutions investigated with temperature were obtained from which thermodynamic parameters of micellization were estimated. It was found that at low temperature the micelle formation process is endothermic and therefore, this process must be entropically driven. However, upon increasing the temperature, the enthalpic factor becomes more significant and, at temperatures higher than 303.15 K the micellization is enthalpy driven. The interactions between C 12 H 25 SO 4 Na/C 12 H 25 SO 3 Na and PEG were studied and it was found that sodium alkyl sulfonates were seen to interact more weakly than their sulfate analogues.

  2. A comparison study between sodium dodecyl sulfate and sodium dodecyl sulfonate with respect to the thermodynamic properties, micellization, and interaction with poly(ethylene glycol) in aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Sadeghi, Rahmat, E-mail: rsadeghi@uok.ac.ir [Department of Chemistry, University of Kurdistan, Sanandaj (Iran, Islamic Republic of); Shahabi, Somayyeh [Department of Chemistry, University of Kurdistan, Sanandaj (Iran, Islamic Republic of)

    2011-09-15

    Graphical abstract: Apparent molar volume against molality: o, {center_dot}, and {Delta}, respectively in water, (1 and 4) wt% PEG solution at 293.15 K; x, {Delta}, and lozenge, respectively in water, (1 and 4) wt% PEG solution at 313.15 K. Research Highlights: > C{sub 12}H{sub 25}SO{sub 3}Na(SDSn) was seen to interact with PEG more weakly than C{sub 12}H{sub 25}SO{sub 4}Na(SDS). > The constraints on molecular mobility of SDS micelles are larger than those of SDSn. > Entropy change on micellization for SDSn is larger than those for SDS. > Micelle formation of SDS is less endothermic and more spontaneous than that of SDSn. > Micelles of SDS have smaller aggregation number than that of SDSn. - Abstract: The density, sound velocity, and conductivity measurements were performed on aqueous solutions of sodium dodecyl sulfate (C{sub 12}H{sub 25}SO{sub 4}Na) or sodium dodecyl sulfonate (C{sub 12}H{sub 25}SO{sub 3}Na) in the absence and presence of poly(ethylene glycol) (PEG) at different temperatures. Changes in the apparent molar volumes and isentropic compressibilities upon micellization were derived using a pseudophase-transition approach and the infinite dilution apparent molar properties of the monomer and micellar form of C{sub 12}H{sub 25}SO{sub 4}Na and C{sub 12}H{sub 25}SO{sub 3}Na were determined. Variations of the critical micelle concentrations (CMCs) of both surfactants in the solutions investigated with temperature were obtained from which thermodynamic parameters of micellization were estimated. It was found that at low temperature the micelle formation process is endothermic and therefore, this process must be entropically driven. However, upon increasing the temperature, the enthalpic factor becomes more significant and, at temperatures higher than 303.15 K the micellization is enthalpy driven. The interactions between C{sub 12}H{sub 25}SO{sub 4}Na/C{sub 12}H{sub 25}SO{sub 3}Na and PEG were studied and it was found that sodium alkyl sulfonates were seen

  3. Antimicrobial activity of complete denture cleanser solutions based on sodium hypochlorite and Ricinus communis – a randomized clinical study

    Directory of Open Access Journals (Sweden)

    Marcela Moreira SALLES

    2015-12-01

    Full Text Available ABSTRACT To preserve oral health and to maintain the prosthetic devices, it is important not only to improve the properties of commonly known hygiene products, but also to investigate new materials with antimicrobial action. Objectives This study evaluated the antimicrobial activity of sodium hypochlorite (0.25% and 0.50% and 10% Ricinus communis’ solutions against specific microorganisms. Material and Methods Sixty four maxillary complete denture wearers were instructed to brush their dentures three times a day and to soak them (20 min/day in the solutions: SH1: 0.25% sodium hypochlorite; SH2: 0.5% sodium hypochlorite; RC: 10% R. communis oil; and C: 0.85% saline (control. The solutions were used for 7 days in a randomized sequence. Following each period of use, there was a 1-week washout period. Antimicrobial activity was determined by Colony Forming Units (CFU counts of Streptococcus mutans, Candida spp., and gram-negative microorganisms. For collecting biofilm, the internal surface of maxillary dentures was brushed with saline solution, and biofilm suspension obtained. After dilutions (100 - 10-3, aliquots were seeded in Mitis salivarius, CHROMagar Candida®, and MacConkey agar for detecting S. mutans, Candida spp., or gram-negative microorganisms, respectively. After incubation, colonies were counted, and CFU/mL values were calculated. Then, transformation - log10 (CFU+1 - data were analyzed using the Friedman test (α=0.05. Results showed significant differences between the solutions (p<0.001. Results All three solutions showed antimicrobial activity against S. mutans. Against Candida spp., RC and SH1 solutions showed similar effect while SH2 showed superior activity. SH1 and SH2 solutions showed antimicrobial action against gram-negative microorganisms. The Candida species most frequently isolated was C. albicans, followed by C. tropicalis and C. glabrata. Conclusions The 0.5% sodium hypochlorite solution was the most effective and

  4. Inhibitive effect of N,N'-Dimethylaminoethanol on carbon steel corrosion in neutral sodium chloride solution, at different temperatures

    OpenAIRE

    Hassoune Mohammed; Bezzar Abdelillah; Sail Latéfa; Ghomari Fouad

    2018-01-01

    The inhibition of carbon steel corrosion in neutral sodium chloride solution by N,N'- Dimethylaminoethanol (DMEA), at different temperatures, was investigated using weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The results obtained confirm that DMEA is a good organic corrosion inhibitor for carbon steel in 0.5M of NaCl (concentration encountered in the Mediterranean seawater), over the whole range of temperatures studied. The inhibition...

  5. Comparison of 2% chlorhexidine and 5.25% sodium hypochlorite irrigating solutions on postoperative pain: a randomized clinical trial.

    Science.gov (United States)

    Bashetty, Kusum; Hegde, Jayshree

    2010-01-01

    To compare the levels of postoperative pain after cleaning and shaping of root canals using two different root canal irrigants for debridement. Forty patients with irreversible pulpitis, pulp necrosis and non-vital teeth exhibiting acute apical periodontitis requiring root canal treatment were included. At random, canals were cleaned and shaped with the following protocols. 2% chlorhexidine solution in group I and 5.25% sodium hypochlorite solution in group II were used as an irrigants. Access cavities were closed with a sterile cotton pellet and cavit. The patients recorded degree of pain at various time intervals after cleaning and shaping on a visual analogue scale for 1 week. The mean pain score for group I was between 0.65 and 3.35 and for group II was between 0.95 and 4.50. There was significant difference in the pain level between the two groups only at 6 th hour postoperatively (P<0.05) and the pain was more in sodium hypochlorite group. More pain was present in teeth irrigated using 5.25% sodium hypochlorite when compared to that in teeth irrigated using 2% chlorhexidine solution. Significant difference in pain level was present only at 6th hour postoperatively, and at all other periods (24 th hour, 4 th and 7 th days) there was no significant difference in pain level between the two groups.

  6. Comparison of 2% chlorhexidine and 5.25% sodium hypochlorite irrigating solutions on postoperative pain: A randomized clinical trial

    Directory of Open Access Journals (Sweden)

    Bashetty Kusum

    2010-01-01

    Full Text Available Aim: To compare the levels of postoperative pain after cleaning and shaping of root canals using two different root canal irrigants for debridement. Materials and Methods: Forty patients with irreversible pulpitis, pulp necrosis and non-vital teeth exhibiting acute apical periodontitis requiring root canal treatment were included. At random, canals were cleaned and shaped with the following protocols. 2% chlorhexidine solution in group I and 5.25% sodium hypochlorite solution in group II were used as an irrigants. Access cavities were closed with a sterile cotton pellet and cavit. The patients recorded degree of pain at various time intervals after cleaning and shaping on a visual analogue scale for 1 week. Results: The mean pain score for group I was between 0.65 and 3.35 and for group II was between 0.95 and 4.50. There was significant difference in the pain level between the two groups only at 6 th hour postoperatively (P<0.05 and the pain was more in sodium hypochlorite group. Conclusions: More pain was present in teeth irrigated using 5.25% sodium hypochlorite when compared to that in teeth irrigated using 2% chlorhexidine solution. Significant difference in pain level was present only at 6th hour postoperatively, and at all other periods (24 th hour, 4 th and 7 th days there was no significant difference in pain level between the two groups.

  7. Electroimpedance Spectroscopy for the Measurement of the Dielectric Properties of Sodium Chloride Solutions at Different Glucose Concentrations

    Directory of Open Access Journals (Sweden)

    Stefano Sbrignadello

    2013-01-01

    Full Text Available We investigated possible variations of impedance values in samples of sodium chloride solution (sodium chloride 0.9% with glucose at different concentrations, ranging from 5000 to around 75 mg/dL. The sodium chloride solution (either saline physiological solution was chosen since it has similarities to blood but no cell components, which may be confounding factors in this study. Special focus was on the effect of stirring and of temperature variations on the impedance spectrum of samples at different glucose concentrations. We found that variations in glucose concentration directly affect the impedance modulus of the sample both in static conditions and in dynamic conditions due to stirring, as well as at both room temperature and at increased temperature. In fact, even if the impedance variations were often small (around 3-4 mΩ per mg/dL, they were usually clearly measurable. These findings may be the basis for possible development of a new approach, based on impedance technology, for the noninvasive monitoring of glycaemia.

  8. Effect of concentration of sodium silicate solution in the synthesis of silica-coated magnetite nanoparticles by ultrasonication

    Science.gov (United States)

    Fajaroh, Fauziatul; Sumari, Nazriati

    2016-02-01

    An ex-situ silica coating of magnetite nanoparticles synthesized electrochemically had been successfully carried out by ultrasonication. An aqueous solution of sodium silicate had been used as silica source.The Si-O-Si, Si-O and Fe-O-Si bonds on the surface of the silica-coated magnetite had been successfully identified using FTIR. Reduction in particle size due to the influence of ultrasound was studied using SEM. Enhancement in the specific surface area of the particles due to the silica coating and reduction in particle size was learned through BET analysis. The Characters of the resulting silica-coated magnetite were influenced by the concentration of sodium silicate solution. The greater the concentration of sodium silicate solution, the smaller the particle crystallinity and the larger the particles surface area was produced. The resulting silica-coated magnetite has a surface area of 38.171 to 67.993 m2/g, otherwise the non-coated particles only has a surface area of 27.894 m2/g. This silica-coated magnetite nanoparticles has more potent as an adsorbent than that of the bare magnetite. Besides that, the presence of silanol groups on its surface makes an opportunity for further functionalization needed for some applications.

  9. Solubility of ammonium metavanadate in ammonium carbonate and sodium bicarbonate solutions at 25 deg C

    International Nuclear Information System (INIS)

    Fedorov, P.I.; Andreev, V.K.; Slotvinskij-Sidak, N.P.

    1978-01-01

    Solubility at 25 deg C has been studied in the system ammonium metavanadate - sodium bicarbonate - water which is a stable section of the corresponding quaternary mutual system. In the eutonic point the content of ammonium metavanadate is 4.95% and of sodium bicarbonate 12.1%. The crystallization branch of ammonium metavanadate has been studied in the system ammonium metavanadate - ammonium carbonate - water at 25 deg C. Metavanadate solubility attains minimum (0.14%) at ammonium carbonate concentration 2.6%. Three sections have been studied of the quaternary system ammonium - metavanadate - ammonium carbonate - sodium bicarbonate-water at 25 deg C in the crystallization region of ammonium metavanadate at a ratio of sodium bicarbonate to ammonium carbonate 3:1, 1:1, and 1:3. A region of minimum solubility of ammonium metavanadate has been detected (0.1%)

  10. Physical Compatibility of Magnesium Sulfate and Sodium Bicarbonate in a Pharmacy-compounded Bicarbonate-buffered Hemofiltration Solution

    Science.gov (United States)

    Moriyama, Brad; Henning, Stacey A.; Jin, Haksong; Kolf, Mike; Rehak, Nadja N.; Danner, Robert L.; Walsh, Thomas J.; Grimes, George J.

    2011-01-01

    PURPOSE To assess the physical compatibility of magnesium sulfate and sodium bicarbonate in a pharmacy-compounded bicarbonate-buffered hemofiltration solution used at the National Institutes of Health Clinical Center (http://www.cc.nih.gov). METHODS Two hemofiltration fluid formulations with a bicarbonate of 50 mEq/L and a magnesium of 1.5 mEq/L or 15 mEq/L were prepared in triplicate with an automated compounding device. The hemofiltration solution with a bicarbonate of 50 mEq/L and a magnesium of 1.5 mEq/L contains the maximum concentration of additives that we use in clinical practice. The hemofiltration solution of 15 mEq/L of magnesium and 50 mEq/L of bicarbonate was used to study the physicochemical properties of this interaction. The solutions were stored without light protection at 22 to 25 °C for 48 hours. Physical compatibility was assessed by visual inspection and microscopy. The pH of the solutions was assayed at 3 to 4 hours and 52 to 53 hours after compounding. In addition, electrolyte and glucose concentrations in the solutions were assayed at two time points after preparation: 3 to 4 hours and 50 to 51 hours. RESULTS No particulate matter was observed by visual and microscopic inspection in the compounded hemofiltration solutions at 48 hours. Electrolyte and glucose concentrations and pH were similar at both time points after solution preparation. CONCLUSION Magnesium sulfate (1.5 mEq/L) and sodium bicarbonate (50 mEq/L) were physically compatible in a pharmacy-compounded bicarbonate-buffered hemofiltration solution at room temperature without light protection at 48 hours. PMID:20237384

  11. Lactated Ringer's solution or 0.9% sodium chloride as fluid therapy in pigeons (Columba livia submitted to humerus osteosynthesis

    Directory of Open Access Journals (Sweden)

    Adriano B. Carregaro

    Full Text Available The study aimed to compare the effects of intraosseous infusion of lactated Ringer's and 0.9% sodium chloride solutions on the electrolytes and acid-base balance in pigeons submitted to humerus osteosynthesis. Eighteen pigeons were undergoing to isoflurane anesthesia by an avalvular circuit system. They were randomly assigned into two groups (n=9 receiving lactated Ringer's solution (LR or 0.9% sodium chloride (SC, in a continuous infusion rate of 20mL/kg/h, by using an intraosseous catheter into the tibiotarsus during 60-minute anesthetic procedure. Heart rate (HR, and respiratory rate (RR were measured every 10 min. Venous blood samples were collected at 0, 30 and 60 minutes to analyze blood pH, PvCO2, HCO3 -, Na+ and K+. Blood gases and electrolytes showed respiratory acidosis in both groups during induction, under physical restraint. This acidosis was evidenced by a decrease of pH since 0 min, associated with a compensatory response, observed by increasing of HCO3 - concentration, at 30 and 60 min. It was not observed any changes on Na+ and K+ serum concentrations. According to the results, there is no reason for choosing one of the two solutions, and it could be concluded that both fluid therapy solutions do not promote any impact on acid-base balance and electrolyte concentrations in pigeons submitted to humerus osteosynthesis.

  12. Fine structures in Fe3Al alloy layer of a new hot dip aluminized steel

    Indian Academy of Sciences (India)

    Unknown

    structure and performance in the coating can be improved and service life of the aluminized steel can significantly be enhanced. 2. Experimental. The base metal of the aluminized steel used in this inves- tigation was mild steel (0⋅18%C), which was aluminized by the hot dip aluminizing technology (HDA). In order to.

  13. The antioxidant properties of oligo sodium alginates prepared by radiation-induced degradation in aqueous and hydrogen peroxide solutions

    Science.gov (United States)

    Şen, Murat; Atik, Hanife

    2012-07-01

    In this study, the radiation-induced degradation of sodium alginates (NaAlg), having different guluronic acids (G) and mannuronic acid (M) ratios, (G/M), in aqueous and hydrogen peroxide solutions were investigated first; after that, the antioxidative properties of the oligo sodium alginates prepared were identified. Radiation degradation yield values, G(S), were determined for each irradiation condition and compared with those of the dry-state-irradiated NaAlg. The results showed that the oligo sodium alginates with M from 1000 to 3750 Da could be easily prepared by γ-irradiation of NaAlg solution in the presence of small amount of hydrogen peroxide at low doses (below 5.0 kGy) and by controlling the G/M. The antioxidant properties of the fractions with various molecular weight and G/M were evaluated by determining the scavenging ability of 1,1-diphenyl-2-picrylhydrazyl free radical (DPPHrad ), and 50% inhibition concentrations of LF120 NaAlg, which was irradiated in aqueous solution and H2O2 solution at a dose of 2.5 kGy and having number average molecular weights of 10.2 and 3.75 kDa were found to be 10.0 and 2.5 mg/ml, respectively. The results demonstrated that its molecular weight was an important factor in controlling the antioxidant properties of NaAlg, and due to the sharp decrease in molecular weight in the case of aqueous media irradiation the effect of G/M of initial polymer became unimportant whereas the dry-state-irradiated NaAlgs behaved conversely.

  14. Removal of Uranium and Associated Contaminants from Aqueous Solutions Using Functional Carbon Nanotubes-Sodium Alginate Conjugates

    Directory of Open Access Journals (Sweden)

    Hussein Allaboun

    2016-02-01

    Full Text Available Synthesis of hydrophilic/hydrophobic beads from functional carbon nanotubes (CNTs conjugated with sodium alginate was investigated. Glutaraldehyde was used as a coupling agent and Ca2+ as a crosslinking agent. The formed conjugate comprises two-dimensional sheets of sodium alginate bounded to long tufts of functional CNT tails of micro-size geometry. Detailed characterization of the conjugates was performed using thermogravimetric analysis (TGA and its first derivative (DTG, Fourier transform infrared (FTIR, and scanning electron microscope (SEM techniques. Different ratios of the conjugate were successfully prepared and used as biodegradable environmentally friendly sorbents. Removal of U6+, V3+, Cr3+, Mo3+, Pb2+, Mn2+, Cu2+, Ti4+ and Ni2+ from aqueous solutions using the synthesized biosorbent was experimentally demonstrated. Maximum metal uptake of 53 mg/g was achieved using the % Functional CNTs = 33 sample.

  15. Behaviour of 29Si NMR and infrared spectra of aqueous sodium and potassium silica solutions as a function of (SiO2/M2+O) ratio

    International Nuclear Information System (INIS)

    Couty, R.; Fernandez, L.

    1996-01-01

    Sodium and potassium solutions of silica with silica concentration of 1,4 mo/kg and R ms = SiO 2 /M + 2 O ratios of 4.56 to 1.6 were obtained by depolymerization of amorphous silica gel in sodium and potassium hydroxide. Solutions have been characterized by 29 Si NMR and infrared spectroscopy. The results indicated that Na + and K + exhibit the same behaviour during the depolymerization of silica. (authors). 11 refs., 4 figs., 2 tabs

  16. Physicochemical and pulp tissue dissolution properties of some household bleach brands compared with a dental sodium hypochlorite solution.

    Science.gov (United States)

    Jungbluth, Holger; Peters, Christine; Peters, Ove; Sener, Beatrice; Zehnder, Matthias

    2012-03-01

    Many clinicians use household bleach to irrigate root canals. Sodium hypochlorite solutions are also available from dental suppliers. We compared physicochemical features of these products and investigated their impact on pulp tissue dissolution. Six different brands of household bleach were bought from drugstores. These were compared with Chlor-XTRA and technical NaOCl solutions of controlled concentration and alkalinity regarding their chlorine content (wt% NaOCl), pH, alkaline capacity, osmolarity, surface tension (Wilhelmy plate method), and price. Bovine pulp tissue (n = 10 specimens per group) dissolution at 37°C by test and control solutions adjusted to 1.0% NaOCl was assessed. Reduction in tissue weight was compared between groups by one-way analysis of variance, followed by Bonferroni correction (P Safeway Bleach Summit Fresh) was slightly alkalized; the other solutions under investigation were not. Osmolarity was similar between products. The surface tension of Chlor-XTRA and Safeway Bleach Summit Fresh was about half that of the other solutions. Tissue dissolution was statistically similar (P > .05) among all solutions. Price was about 100-fold higher per liter of Chlor-XTRA compared with household bleach. Other than its price, the Chlor-XTRA solution had no unique features. In contrast to an earlier report, reduced surface tension did not result in greater soft tissue dissolution by NaOCl. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  17. Evaluation of 6 years use of sodium hydroxide solution to clear partially occluded central venous catheters

    NARCIS (Netherlands)

    Bader, Suzanne G.; Balke, Petra; Jonkers-Schuitema, Cora F.; Tas, Tirzah A. J.; Sauerwein, Hans P.

    2007-01-01

    BACKGROUND & AIMS: Central venous catheter occlusion is a frequently occurring complication during home parenteral nutrition (HPN). The aim of the study was to investigate the effectiveness of sodium hydroxide (NaOH) administration to clear an occluded central venous catheter especially in HPN.

  18. Preparation of Organized Mesoporous Silica from Sodium Metasilicate Solutions in Alkaline Medium using Nonionic Surfactants

    Czech Academy of Sciences Publication Activity Database

    Zukalová, Markéta; Rathouský, Jiří; Zukal, Arnošt

    2003-01-01

    Roč. 68, č. 10 (2003), s. 2019-2031 ISSN 0010-0765 Institutional research plan: CEZ:AV0Z4040901 Keywords : mesoporous SiO2 * sodium metasilicate * nonionic surfactants Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.041, year: 2003

  19. Semi-Batch Reactive Distillation of Consecutive Reaction : The Saponification Reaction of Diethyl Adipate with Sodium Hydroxide Solution

    Directory of Open Access Journals (Sweden)

    Raghad Fareed Kasim

    2016-03-01

    Full Text Available This research presents a new study in reactive distillation by using consecutive reaction: the saponification reaction of diethyl adipate (DA with sodium hydroxide solution . The effect of three parameters were studied through a design of experiments applying 23 factorial design . These parameters were : the mole ratio of DA to NaOH solution (0.1 and 1 , NaOH solution concentration (3 N and 8 N , and batch time (1.5 hr. and 3.5 hr. . The conversion of DA to sodium monoethyladipate(SMA(intermediate product was the effect of these parameters which was detected . Also , the percentage purity of the intermediate product was recorded . The results showed that increasing mole ratio of DA to NaOHsolution increases the conversion and percentage purity to a maximum value within the range of study . The effect of NaOH solution concentration decreases the conversion and percentage purity to specified value within the range of study . The effect of batch time on conversion and percentage purity , when NaOH solution concentration (3 N is as follows : the increasing in batch time decreases the conversion and percentage purity to specified value within the range of study . When NaOH solution concentration (8 N increasing batch time decreases the conversion , while percentage purity increases with increasing batch time to a maximum value within the range of study . The maximum attainable conversion within the studied range of parameters was eighteen fold of the base case , while the maximum percentage purity was (99.40 % . Empirical equation was obtained using statistical analysis of experimental results . The empirical results of relative conversion was drawn . The empirical graphs showed linear variation .

  20. Thermochemical properties of gibbsite, bayerite, boehmite, diaspore, and the aluminate ion between 0 and 350/degree/C

    International Nuclear Information System (INIS)

    Apps, J.A.; Neil, J.M.; Jun, C.H.

    1989-01-01

    A requirement for modelling the chemical behavior of groundwater in a nuclear waste repository is accurate thermodynamic data pertaining to the participating minerals and aqueous species. In particular, it is important that the thermodynamic properties of the aluminate ion be accurately determined, because most rock forming minerals in the earth's crust are aluminosilicates, and most groundwaters are neutral to slightly alkaline, where the aluminate ion is the predominant aluminum species in solution. Without a precise knowledge of the thermodynamic properties of the aluminate ion aluminosilicate mineral solubilities cannot be determined. The thermochemical properties of the aluminate ion have been determined from the solubilities of the aluminum hydroxides and oxyhydroxides in alkaline solutions between 20 and 350/degree/C. An internally consistent set of thermodynamic properties have been determined for gibbsite, boehmite, diaspore and corundum. The thermodynamic properties of bayerite have been provisionally estimated and a preliminary value for ΔG/sub f, 298/ 0 of nordstrandite has been determined. 205 refs., 17 figs., 25 tabs

  1. Thermochemical properties of gibbsite, bayerite, boehmite, diaspore, and the aluminate ion between 0 and 350/degree/C

    Energy Technology Data Exchange (ETDEWEB)

    Apps, J.A.; Neil, J.M.; Jun, C.H.

    1989-01-01

    A requirement for modelling the chemical behavior of groundwater in a nuclear waste repository is accurate thermodynamic data pertaining to the participating minerals and aqueous species. In particular, it is important that the thermodynamic properties of the aluminate ion be accurately determined, because most rock forming minerals in the earth's crust are aluminosilicates, and most groundwaters are neutral to slightly alkaline, where the aluminate ion is the predominant aluminum species in solution. Without a precise knowledge of the thermodynamic properties of the aluminate ion aluminosilicate mineral solubilities cannot be determined. The thermochemical properties of the aluminate ion have been determined from the solubilities of the aluminum hydroxides and oxyhydroxides in alkaline solutions between 20 and 350/degree/C. An internally consistent set of thermodynamic properties have been determined for gibbsite, boehmite, diaspore and corundum. The thermodynamic properties of bayerite have been provisionally estimated and a preliminary value for ..delta..G/sub f, 298//sup 0/ of nordstrandite has been determined. 205 refs., 17 figs., 25 tabs.

  2. Extraction of DBP and MBP from actinides: application to the recovery of actinides from TBP-sodium carbonate scrub solutions

    International Nuclear Information System (INIS)

    Horwitz, E.P.; Mason, G.W.; Bloomquist, C.A.A.; Leonard, R.A.; Bernstein, G.J.

    1980-01-01

    A flowsheet for the recovery of actinides from TBP-Na 2 CO 3 scrub waste solutions has been developed, based on batch extraction data, and tested, using laboratory scale counter-current extraction techniques. The process, called the ARALEX process, utilizes 2-ethyl-1-hexanol (2-EHOH) to extract the TBP degradation products (HDBP and H 2 MBP) from acidified Na 2 CO 3 scrub waste leaving the actinides in the aqueous phase. Dibutyl and monobutyl phosphoric acids are attached to the 2-EHOH molecules through hydrogen bonds. These hydrogen bonds also diminish the ability of the HDBP and H 2 MBP to complex actinides and thus all actinides remain in the aqueous raffinate. Dilute sodium hydroxide solutions can be used to back-extract the dibutyl and monobutyl phosphoric acid esters as their sodium salts. The 2-EHOH can then be recycled. After extraction of the acidified carbonate waste with 2-EHOH, the actinides may be readily extracted from the raffinate with DHDECMP or, in the case of tetra- and hexavalent actinides, with TBP. The ARALEX process is relatively simple and involves inexpensive and readily available chamicals. The ARALEX process can also be applied to other actinide waste streams which contain appreciable concentrations of polar organic compounds that interfere with conventional actinide ion exchange and liquid-liquid extraction procedures. One such application is the removal of detergents from laundry or clean-up solutions contaminated with actinides

  3. Inhibitive effect of N,N'-Dimethylaminoethanol on carbon steel corrosion in neutral sodium chloride solution, at different temperatures

    Directory of Open Access Journals (Sweden)

    Hassoune Mohammed

    2018-01-01

    Full Text Available The inhibition of carbon steel corrosion in neutral sodium chloride solution by N,N'- Dimethylaminoethanol (DMEA, at different temperatures, was investigated using weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS techniques. The results obtained confirm that DMEA is a good organic corrosion inhibitor for carbon steel in 0.5M of NaCl (concentration encountered in the Mediterranean seawater, over the whole range of temperatures studied. The inhibition efficiency (IE% increases with increasing DMEA concentration; it reaches highest value for a concentration around 0.125 mol.L-1. Potentiodynamic polarization data show that, the compound studied in this research predominantly act as anodic-type inhibitor. The EIS study reveals that the addition of DMEA decreases the corrosion rate of carbon steel in neutral sodium chloride solution, due to the fact that the inhibitor molecules are strongly adsorbed on the active sites following Langmuir isotherm, thus leading to the formation of a stable protective film on the steel surface which is able to keep the metal/solution interface in a passive state. Furthermore, the values of the activation parameters, i.e. ΔHa and Ea obtained in this study indicate that the adsorption process of DMEA is endothermic and could be mainly attributed to chemisorption, respectively.

  4. Penetration of protective gloves as a route of intake for tritiated water and 125I-labelled sodium iodine solution

    International Nuclear Information System (INIS)

    Harris, S.J.; Gilmore, A.

    1980-01-01

    Measurements have been made of the rate at which tritiated water and 125 I-labelled sodium iodide solution penetrate various types of protective gloves, both isotopes being in common use in this form in universities and similar establishments. Diffusion coefficients relating to the glove materials are also determined. The health physics aspects are discussed and it is concluded that intakes by workers through intact gloves are not likely to be of major significance and can easily be minimised by the correct use and choice of glove. (author)

  5. Leaching of silicon from ferronickel (FeNi) smelting slag with sodium hydroxide solution at atmospheric pressure

    Science.gov (United States)

    Mufakhir, F. R.; Mubarok, M. Z.; Ichlas, Z. T.

    2018-01-01

    The present paper reports the leaching behavior of silicon from ferronickel slag under atmospheric pressure using sodium hydroxide solution. The effect of several experimental variables, namely concentration of leaching agent, operating temperature, stirring speed, and slurry density was investigated. The leaching kinetic was also investigated by using shrinking core model. It was determined that leaching of silicon from the slag was controlled by diffusion through product layer, although the activation energy was found to be 85.84 kJ/mol, which was unusually high for such a diffusion-controlled process.

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

    Science.gov (United States)

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

    2016-01-01

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

  7. Structural simulation of superlattices in lithium aluminates

    International Nuclear Information System (INIS)

    Carrera G, L.M.; Basurto S, R.

    1997-01-01

    Among the materials to be used on the tritium generator cover of the future fusion reactors the lithium aluminate (γ - LiAlO 2 ) is one of the more studied. In this work it is presented the superlattice structural simulation that presents to γ - LiAlO 2 as main phase and to α - LiAlO 2 as the secondary phase. The simulation is developed considering that as the two phases present different symmetry (γ - LiAlO 2 is tetrahedral and α - LiAlO 2 is hexahedral) it is had a superlattice LUCS type (Layered Ultrathin Coherent Structure) that is it presents an structure in coherent ultrathin layers since it is what implicates a lesser energy of formation. (Author)

  8. Carbonation of calcium aluminate cement pastes

    Directory of Open Access Journals (Sweden)

    Fernández-Carrasco, L.

    2001-12-01

    Full Text Available This work discusses the results from accelerated tests intended to investigate the ways the different curing methods affect the carbonation of calcium aluminate cements pastes (CAC. The research was focused on the mineralogical composition of hydrated and carbonated samples. The compressive strengths and the porosity of the samples have been determined. Results point out that vaterite and aragonite are formed as a result of carbonation of both cubic and hexagonal calcium aluminate hydrates. The polymorph of calcium carbonate formed does not depend on the curing process. Carbonation rates is higher in hexagonal than in cubic hydrates. Results obtained through this study evidence that, as a consequence of the carbonation process of CAC pastes, in test conditions, an increase of the mechanical strengths occurs.

    En el presente trabajo se discuten los resultados obtenidos en los ensayos acelerados llevados a cabo para investigar los efectos de diferentes métodos de curado sobre la carbonatacion de pastas del cemento de aluminato de calcio (CAC. Se estudió la composición mineralógica de las muestras hidratadas y carbonatadas. Además, se determinaron las resistencias mecánicas a compresión y la porosidad de las probetas. Los resultados indican que la vaterita y el aragonito son las polimorfías del CaCO3 que se forman al carbonatar los aluminatos cálcicos hidratos, tanto los de naturaleza hexagonal como cúbica. El polimorfo del carbonato cálcico formado no depende del proceso de curado. La velocidad de carbonatación de los hidratos hexagonales es mayor que la de los cúbicos. Los resultados obtenidos en el presente trabajo han evidenciado que como consecuencia del proceso de carbonatación sobre pastas de CAC, en las condiciones realizadas, se produce un incremento en las resistencias mecánicas.

  9. Electrochemical evaluation of sodium metabisulfite as environmentally friendly inhibitor for corrosion of aluminum alloy 6061 in a chloride solution

    Energy Technology Data Exchange (ETDEWEB)

    Zaid, B., E-mail: zaidbachir@yahoo.com [Département de métallurgie, Division de Technologie du Combustible, Centre de Recherche Nucléaire de Draria CRND, BP. 43 Draria, Alger (Algeria); Maddache, N.; Saidi, D. [Département de métallurgie, Division de Technologie du Combustible, Centre de Recherche Nucléaire de Draria CRND, BP. 43 Draria, Alger (Algeria); Souami, N. [Centre de Recherche Nucléaire d’Alger CRNA, 2 Bd. Frantz Fanon, Alger (Algeria); Bacha, N. [Département de Mécanique, Université SAAD Dahleb, Blida (Algeria); Si Ahmed, A. [Im2np, UMR 7334 CNRS, Aix-Marseille Université, 13397 Marseille Cedex 20 (France)

    2015-04-25

    Highlights: • Sodium metabisulfite acts as cathodic-type inhibitor. • The polarization resistance increases with the inhibitor concentration. • The pit nucleation rate decreases with increasing inhibitor concentration. • The current rise linked to pit propagation drops as inhibitor content increases. • The reactions involved in the inhibition actions are pointed out. - Abstract: Inhibition properties of sodium metabisulfite (Na{sub 2}S{sub 2}O{sub 5}) on pitting corrosion of 6061 aluminum alloy, in 5 × 10{sup −2} M NaCl solution of pH near 7.2 at 298 K, are characterized using open circuit potential, polarization resistance, cyclic and chrono-amperometric polarization measurements. In addition, scanning electron microscopy coupled with energy dispersive spectroscopy and X-ray photoelectrons are employed. Sodium metabisulfite, which is well compatible with environmental requirements, seems to act as a cathodic-type corrosion inhibitor. The passivation range and the polarization resistance increase with Na{sub 2}S{sub 2}O{sub 5} concentration. The inhibition effects are also reflected through the substantial reduction of both the rate of pit nucleation and the current rise characterizing the pit propagation progress. The SEM–EDS and XPS analyses reveal the formation of a passive film, which contains sulfur atoms.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-07-15

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

  11. Volumetric and isentropic compressibility behaviour of aqueous solutions of (polyvinylpyrrolidone + sodium citrate) at T = (283.15 to 308.15) K

    International Nuclear Information System (INIS)

    Sadeghi, Rahmat; Ziamajidi, Fatemeh

    2007-01-01

    The apparent specific volumes and isentropic compressibilities have been determined for polyvinylpyrrolidone in aqueous solutions of sodium citrate by density and sound velocity measurements at T = (283.15 to 308.15) K at atmospheric pressure. The results show a positive transfer volume of PVP from an aqueous solution to an aqueous sodium citrate solution. For low concentrations of PVP, the apparent specific volumes of PVP in water increased along with an increase in the polymer mass fraction, while in aqueous sodium citrate solutions decreased along with an increase in the polymer mass fraction. For high concentrations of PVP, the apparent specific volumes of PVP in water and in aqueous sodium citrate solutions were independent of the polymer mass fraction. The apparent specific isentropic compressibility of PVP is negative at T = (283.15 and 288.15) K, which imply that the water molecules around the PVP molecules are less compressible than the water molecules in the bulk solutions. The positive values of apparent specific isentropic compressibility at T = (298.15, 303.15, and 308.15) K imply that the water molecules around the PVP molecules are more compressible than the water molecules in the bulk solutions. Finally, it was found that the apparent specific isentropic compressibility of PVP increases as the concentration of sodium citrate increases

  12. Possibilities of using aluminate cements in high-rise construction

    Science.gov (United States)

    Kaddo, Maria

    2018-03-01

    The article describes preferable ways of usage of alternative binders for high-rise construction based on aluminate cements. Possible areas of rational use of aluminate cements with the purpose of increasing the service life of materials and the adequacy of the durability of materials with the required durability of the building are analyzed. The results of the structure, shrinkage and physical and mechanical properties of concrete obtained from dry mixes on the base of aluminate cements for self-leveling floors are presented. To study the shrinkage mechanism of curing binders and to evaluate the role of evaporation of water in the development of shrinkage was undertaken experiment with simple unfilled systems: gypsum binder, portland cement and «corrosion resistant high alumina cement + gypsum». Principle possibility of binder with compensated shrinkage based on aluminate cement, gypsum and modern superplasticizers was defined, as well as cracking resistance and corrosion resistance provide durability of the composition.

  13. Foam capacity and stability of Sodium Dodecyl Sulfate (SDS) on the presence of contaminant coffee and Cd ions in solution

    Science.gov (United States)

    Haryanto, B.; Chang, C. H.; Kuo, A. T.; Siswarni, M. Z.; Sinaga, T. M. A.

    2018-02-01

    In this study, the effect of the coffee colloidal particle and Cd ion contaminant on the foam capacity and stability of sodium dodecyl sulfate (SDS) solution was investigated. The foam was generated by using a foam generator. The foam capacity of SDS was first evaluated at different concentrations. After the foam capacity reaching a constant value, the foam stability was then measured by flowing to a column. The results showed that the presence the coffee colloidal particles or Cd ions in the solution would decrease the foam capacity and stability of SDS. In addition, the decreased foam capacity and stability was more pronounced in the presence of coffee colloidal particles than Cd ions. The colloidal particles may have stronger interaction with SDS and thus reduce the formation of the foam.

  14. In vitro bioactivity of soda lime borate glasses with substituted SrO in sodium phosphate solution

    Directory of Open Access Journals (Sweden)

    Mohamed A. Marzouk

    2014-09-01

    Full Text Available Borate glasses with the basic composition 0.6B2O3·0.2Na2O·0.2CaO and SrO progressively substituting CaO were prepared and characterized for their bone-bonding ability. The obtained glasses were thermally treated and converted to their glass-ceramic derivatives. In this study, FTIR spectral analyses were done for the prepared glasses and glass-ceramics before and after immersion in a sodium phosphate solution for extended times. The appearance of two IR bands within the spectral range 550–680 cm-1 after immersion confirms the formation of hydroxyapatite. X-ray diffraction studies and scanning electron microscope analysis supported the obtained infrared spectroscopy results. The solubility test (measurements of the weight loss in aqueous sodium phosphate solution was conducted for measuring the dissolution of both glassy and crystalline derivatives to find out the role of SrO. The corrosion behaviour of the glasses and glass-ceramics indicate the increase of weight loss with the increase of SrO content. Different suggested proposals were introduced to explain this abnormal behaviour.

  15. Inorganic polymers from laterite using activation with phosphoric acid and alkaline sodium silicate solution: Mechanical and microstructural properties

    International Nuclear Information System (INIS)

    Enzo Ferrari, Università degli studi di Modena e Reggio Emilia, Via Vignolese 905/a, I-41125 Modena (Italy))" data-affiliation=" (Dipartimento di Ingegneria Enzo Ferrari, Università degli studi di Modena e Reggio Emilia, Via Vignolese 905/a, I-41125 Modena (Italy))" >Lassinantti Gualtieri, Magdalena; Enzo Ferrari, Università degli studi di Modena e Reggio Emilia, Via Vignolese 905/a, I-41125 Modena (Italy))" data-affiliation=" (Dipartimento di Ingegneria Enzo Ferrari, Università degli studi di Modena e Reggio Emilia, Via Vignolese 905/a, I-41125 Modena (Italy))" >Romagnoli, Marcello; Pollastri, Simone; Gualtieri, Alessandro F.

    2015-01-01

    Geopolymers from laterite, an iron-rich soil available in developing countries, have great potential as building materials. In this work, laterite from Togo (Africa) was used to prepare geopolymers using both phosphoric acid and alkaline sodium silicate solution. Microstructural properties were investigated by scanning electron microscopy, X-ray powder diffraction and mercury porosimetry, whereas thermal properties were evaluated by thermal analyses. The local environment of iron was studied by X-ray Absorption Spectroscopy (XANES region). The mechanical properties were determined. Modulus of Rupture and Young's modulus fell in the ranges 3.3–4.5 MPa and 12–33 GPa, respectively, rendering the materials good candidates for construction purposes. Heating above 900 °C results in weight-gain, presumably due to iron redox reactions. X-ray Absorption Spectroscopy data evidence changes in the chemical and structural environments of iron following thermal treatment of geopolymers. These changes indicate interaction between the geopolymer structure and iron during heating, possibly leading to redox properties. -- Highlights: •Geopolymerization of laterite is promising for fabrication of building materials. •Both phosphoric acid and alkaline sodium silicate solution can be used for activation. •Thermally activated redox properties of the inorganic polymers were observed

  16. Inorganic polymers from laterite using activation with phosphoric acid and alkaline sodium silicate solution: Mechanical and microstructural properties

    Energy Technology Data Exchange (ETDEWEB)

    Lassinantti Gualtieri, Magdalena, E-mail: magdalena.gualtieri@unimore.it [Dipartimento di Ingegneria " Enzo Ferrari" , Università degli studi di Modena e Reggio Emilia, Via Vignolese 905/a, I-41125 Modena (Italy); Romagnoli, Marcello [Dipartimento di Ingegneria " Enzo Ferrari" , Università degli studi di Modena e Reggio Emilia, Via Vignolese 905/a, I-41125 Modena (Italy); Pollastri, Simone; Gualtieri, Alessandro F. [Dipartimento di Scienze Chimiche e Geologiche, Università degli studi di Modena e Reggio Emilia, Via S. Eufemia 19I, I-41121 Modena (Italy)

    2015-01-15

    Geopolymers from laterite, an iron-rich soil available in developing countries, have great potential as building materials. In this work, laterite from Togo (Africa) was used to prepare geopolymers using both phosphoric acid and alkaline sodium silicate solution. Microstructural properties were investigated by scanning electron microscopy, X-ray powder diffraction and mercury porosimetry, whereas thermal properties were evaluated by thermal analyses. The local environment of iron was studied by X-ray Absorption Spectroscopy (XANES region). The mechanical properties were determined. Modulus of Rupture and Young's modulus fell in the ranges 3.3–4.5 MPa and 12–33 GPa, respectively, rendering the materials good candidates for construction purposes. Heating above 900 °C results in weight-gain, presumably due to iron redox reactions. X-ray Absorption Spectroscopy data evidence changes in the chemical and structural environments of iron following thermal treatment of geopolymers. These changes indicate interaction between the geopolymer structure and iron during heating, possibly leading to redox properties. -- Highlights: •Geopolymerization of laterite is promising for fabrication of building materials. •Both phosphoric acid and alkaline sodium silicate solution can be used for activation. •Thermally activated redox properties of the inorganic polymers were observed.

  17. Localized corrosion of alloys C-276 and 625 in aerated sodium chloride solutions at 25 to 200 degrees C

    International Nuclear Information System (INIS)

    Postlethwaite, J.

    1991-12-01

    Two molybdenum-bearing nickel alloys, Alloy C-276 and Alloy 625, were previously identified for consideration as candidate container materials for the Canadian Nuclear Fuel Waste Management Program. Because of the paucity of data for the localized corrosion behaviour of these passive alloys under conditions that may be experienced in a disposal vault, this project was undertaken to study the crevice and pitting corrosion of Alloys C-276 and 625 in chloride solutions at elevated temperatures. Electrochemical and immersion tests have been conducted in neutral sodium chloride solutions (0.1 wt% to saturated) at 25 to 200 degrees C, in an attempt to identify the conditions under which localized corrosion occurs and to relate the actual corrosion behaviour to that expected on the basis of electrochemical studies. Cyclic polarization studies showed that the passivation breakdown potentials move rapidly to more active values with increasing temperatures. Above 100 degrees C the resistance to localized corrosion is greatly reduced. The results of the immersion tests are presented in the form of T versus (C1-) diagrams. These susceptibility diagrams suggest that there is a limiting crevice-corrosion temperature for each alloy in aerated, neutral sodium chloride solutions. Below this temperature corrosion does not occur, regardless of the chloride concentration. The values of the limiting crevice-corrosion temperatures were in the range 100 to 125 degrees C for Alloy C-276 and 100 to 115 degrees C for Alloy 625. Such values suggest that saturation of the chloride solutions by surface boiling could occur without the initiation of localized corrosion. These electrochemical results indicate that a large safety margin for susceptibility to localized corrosion might be found below 100 degrees C

  18. Measurements of density and of thermal expansion coefficient of sodium tetraborate (borax)-UO2 and of sodium metaborate-UO2 solutions

    International Nuclear Information System (INIS)

    Dalle Donne, M.; Dorner, S.

    1980-12-01

    Measurements have been performed of the density and volumetric thermal expansion coefficient of liquid sodium tetraborate (borax) and of sodium metaborate both pure and with two different amounts of UO 2 dissolved in each. These data are required for the design of core-catchers based on sodium borates. The measurements have been performed with the buoyancy method in the temperature range from 850 0 C to 1325 0 C. The data for the pure borax and for the sodium metaborate agree reasonably well with the data from the literature, giving confidence that the measurements are correct and the new data for the salts with UO 2 are reliable. (orig.) [de

  19. Calcium aluminates potential for endodontics and orthopedics applications

    International Nuclear Information System (INIS)

    Santos, G.L. dos; Andrade, T.L.; Oliveira, I.R.; Pandolfelli, V.C.

    2011-01-01

    The mostly used material in the areas of endodontics (MTA, mineral trioxide aggregate) and bone reconstruction (PMMA, polymethyl methacrylate) present some limiting properties requiring thus changes in their compositions as well as the development of alternative materials. In this context, a novel biomaterial-based calcium aluminate cement (CAC) has been studied in order to keep the positive properties and clinical applications of MTA and PMMA, overcoming some their disadvantages. Recent studies involving the use of CAC are based on commercial products consisting of a mixture of phases. Improvements can be attained by searching the synthesis routes of CAC aiming the proper balance between the phases and the control of impurities that may impair its performance in applications in the areas of health. By the optimization of the CAC phases production, this article aims to present their characterization based on hydration temperature; working time and setting time; pH, ions solubilization and dissolution in contact with water and different solutions of simulated body fluid. The results indicated the CA phase as the most suitable for application in the areas of health. (author)

  20. A potential model for sodium chloride solutions based on the TIP4P/2005 water model

    Science.gov (United States)

    Benavides, A. L.; Portillo, M. A.; Chamorro, V. C.; Espinosa, J. R.; Abascal, J. L. F.; Vega, C.

    2017-09-01

    Despite considerable efforts over more than two decades, our knowledge of the interactions in electrolyte solutions is not yet satisfactory. Not even one of the most simple and important aqueous solutions, NaCl(aq), escapes this assertion. A requisite for the development of a force field for any water solution is the availability of a good model for water. Despite the fact that TIP4P/2005 seems to fulfill the requirement, little work has been devoted to build a force field based on TIP4P/2005. In this work, we try to fill this gap for NaCl(aq). After unsuccessful attempts to produce accurate predictions for a wide range of properties using unity ionic charges, we decided to follow recent suggestions indicating that the charges should be scaled in the ionic solution. In this way, we have been able to develop a satisfactory non-polarizable force field for NaCl(aq). We evaluate a number of thermodynamic properties of the solution (equation of state, maximum in density, enthalpies of solution, activity coefficients, radial distribution functions, solubility, surface tension, diffusion coefficients, and viscosity). Overall the results for the solution are very good. An important achievement of our model is that it also accounts for the dynamical properties of the solution, a test for which the force fields so far proposed failed. The same is true for the solubility and for the maximum in density where the model describes the experimental results almost quantitatively. The price to pay is that the model is not so good at describing NaCl in the solid phase, although the results for several properties (density and melting temperature) are still acceptable. We conclude that the scaling of the charges improves the overall description of NaCl aqueous solutions when the polarization is not included.

  1. The influence of aqueous sodium dodecyl sulphate solution in the photoresponsivity of nitrogen doped graphene oxide photodetector

    Science.gov (United States)

    Ahmad, H.; Thandavan, T. M. K.

    2017-11-01

    The homogeneity and agglomeration in graphene based photodetector plays an important role in the photoconduction. The influence of sodium dodecyl sulphate (SDS) solution in nitrogen doped graphene oxide (N-GO) is studied based on the photoresponsivity behaviour. One step hydrothermal method and drop casting technique are utilized to obtain N-GO photodetectors. High photoresponsivity about 1000 folds is achieved in N-GO prepared with SDS solution (N-GO/SDS) compared to the N-GO prepared without SDS solution. Raman spectrum also revealed a high intense D and G band as well as a slightly broaden 2D band due to sp2 hybridization. The fabricated device has exhibited wide range of responsivity to infrared (IR) laser 974 nm pulse and illumination. Real time current measurement in N-GO and current-voltage (I-V) characteristics in N-GO/SDS showed a significant photoconduction due to laser 974 nm illumination. The external quantum efficiency (EQE) in the N-GO/SDS solution is about 394830% compared to N-GO prepared without SDS, which is only 272%. The evaluated fall time at frequency modulation of 0.1 and 1 Hz for direct current (dc) bias voltage of 5.0 V found to be shorter compared to that of 2.5 V, whereas the fall time at high frequency modulation at 5000 Hz exhibited similar time around 77 μs.

  2. Effect of use of socially marketed faucet fitted earthen vessel/sodium hypochlorite solution on diarrhea prevention at household level in rural India

    Directory of Open Access Journals (Sweden)

    AR Dongre

    2008-07-01

    Full Text Available Objective: To evaluate the effect of socially marketed faucet fitted to earthen vessel / sodium hypochlorite solution on diarrhea prevention at rural household level as a social intervention for diarrhea prevention under ‘Community Led Initiatives for Child Survival (CLICS program. Methods: Unmatched case-control study was carried out in 10 villages of Primary Health Centre, Anji, located in rural central India. During the study period, 144 households used either faucet fitted earthen vessel to store drinking water or used sodium hypochlorite solution (SH for keeping drinking water safe. These served as case households for the present study. 213 neighborhood control households from same locality who used neither of the methods were also selected. Results: Odds ratio for households who used faucets fitted to earthen vessel was 0.49 (95% CI= 0.25 – 0.95. Odds ratio for households who used sodium hypochlorite solution was 0.55 (95% CI= 0.31 – 0.98. Use of these methods by the community, would prevent about 27 percent and 22 percent cases of the diarrhea (Population attributable risk proportion = 0.25 by faucets fitted to earthen vessels and 0.22 by use of sodium hypochlorite solution respectively. Conclusion: To ensure safe drinking water at household level, the effective and cheap methods like fitting faucet to traditionally used earthen vessel and/or use of sodium hypochlorite solution must be promoted through community participation at household level for cost and culture sensitive rural people in India.

  3. Antiseptic solutions modulate the paracrine-like activity of bone chips: differential impact of chlorhexidine and sodium hypochlorite.

    Science.gov (United States)

    Sawada, Kosaku; Caballé-Serrano, Jordi; Bosshardt, Dieter D; Schaller, Benoit; Miron, Richard J; Buser, Daniel; Gruber, Reinhard

    2015-09-01

    Chemical decontamination increases the availability of bone grafts; however, it remains unclear whether antiseptic processing changes the biological activity of bone. Bone chips were incubated with four different antiseptic solutions including (1) povidone-iodine (0.5%), (2) chlorhexidine diguluconate (0.2%), (3) hydrogen peroxide (1%) and (4) sodium hypochlorite (0.25%). After 10 min. of incubation, changes in the capacity of the bone-conditioned medium (BCM) to modulate gene expression of gingival fibroblasts was investigated. Conditioned medium obtained from freshly prepared bone chips increased the expression of TGF-β target genes interleukin 11 (IL11), proteoglycan4 (PRG4), NADPH oxidase 4 (NOX4), and decreased the expression of adrenomedullin (ADM), and pentraxin 3 (PTX3) in gingival fibroblasts. Incubation of bone chips with 0.2% chlorhexidine, followed by vigorously washing resulted in a BCM with even higher expression of IL11, PRG4 and NOX4. These findings were also detected with a decrease in cell viability and an activation of apoptosis signalling. Chlorhexidine alone, at low concentrations, increased IL11, PRG4 and NOX4 expression, independent of the TGF-β receptor I kinase activity. In contrast, 0.25% sodium hypochlorite almost entirely abolished the activity of BCM, whereas the other two antiseptic solutions, 1% hydrogen peroxide and 0.5% povidone-iodine, had relatively no impact respectively. These in vitro findings demonstrate that incubation of bone chips with chlorhexidine differentially affects the activity of the respective BCM compared to the other antiseptic solutions. The data further suggest that the main effects are caused by chlorhexidine remaining in the BCM after repeated washing of the bone chips. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. Effects of hypertonic sodium chloride solution on the electrophysiologic alterations caused by bupivacaine in the dog heart

    Directory of Open Access Journals (Sweden)

    Scalabrini A.

    2003-01-01

    Full Text Available The effects of various hypertonic solutions on the intraventricular conduction, ventricular repolarization and the arrhythmias caused by the intravenous (iv injection of bupivacaine (6.5 mg/kg were studied in sodium pentobarbital-anesthetized mongrel dogs. Hypertonic solutions, given iv 5 min before bupivacaine, were 7.5% (w/v NaCl, 5.4% (w/v LiCl, 50% (w/v glucose (2,400 mOsm/l, 5 ml/kg, or 20% (w/v mannitol (1,200 mOsm/l, 10 ml/kg. Bupivacaine induced severe arrhythmias and ventricular conduction and repolarization disturbances, as reflected by significant increases in QRS complex duration, HV interval, IV interval and monophasic action potential duration, as well as severe hemodynamic impairment. Significant prevention against ventricular electrophysiologic and hemodynamic disturbances and ventricular arrhythmias was observed with 7.5% NaCl (percent increase in QRS complex duration: 164.4 ± 21.8% in the non-pretreated group vs 74.7 ± 14.1% in the pretreated group, P<0.05; percent increase in HV interval: 131.4 ± 16.1% in the non-pretreated group vs 58.2 ± 7.5% in the pretreated group, P<0.05; percent increase in monophasic action potential duration: 22.7 ± 6.8% in the non-pretreated group vs 9.8 ± 6.3% in the pretreated group, P<0.05; percent decrease in cardiac index: -46 ± 6% in the non-pretreated group vs -28 ± 5% in the pretreated group, P<0.05. The other three hypertonic solutions were ineffective. These findings suggest an involvement of sodium ions in the mechanism of hypertonic protection.

  5. Study on Corrosion and Stress Corrosion Cracking Behaviors of AZ31 Alloy in Sodium Sulfate Solution

    Science.gov (United States)

    He, Xiuli; Yan, Zhifeng; Liang, Hongyu; Wei, Yinghui

    2017-05-01

    The potentiodynamic polarization test and slow strain rate tensile test were carried out in 3.5 wt.% Na2SO4 solution with different pH values (2, 7, and 12). It was found that the SCC susceptibility of AZ31 magnesium alloy in 3.5 wt.% Na2SO4 solution was deteriorated significantly with the decreasing pH. This was consistent with the electrochemical properties. There were filiform corrosion forms on the specimen surface after slow strain rate tensile test in 3.5 wt.% Na2SO4 solution, which indicated the characteristics of general corrosion. Moreover, there were multiple stress corrosion crack initiation sources. The SCC fracture of AZ31 magnesium alloy in air was a mix type, while it was cleavage fracture in 3.5 wt.% Na2SO4 solution.

  6. Calibration of the A.E.E. Winfrith whole body monitor equipment with sodium-24 solution in a polythene man-phantom

    International Nuclear Information System (INIS)

    Peabody, C.O.; Speight, R.G.; Passant, F.H.

    1964-04-01

    Results are presented for the sensitivity of the existing Winfrith Whole Body Monitor equipment when used for measurement of sodium-24 activity in solution in a polythene man-phantom. The relationship is discussed between these results and those expected for the sodium-24 produced in a human body by accidental neutron irradiation. Estimates are made of the additional contribution of chlorine-38 activity at various times after whole body irradiation. (author)

  7. Shelf life, dissolving action, and antibacterial activity of a neutralized 2.5% sodium hypochlorite solution.

    Science.gov (United States)

    Camps, Jean; Pommel, Ludovic; Aubut, Virginie; Verhille, Bernard; Satoshi, Fukuzaki; Lascola, Bernad; About, Imad

    2009-08-01

    The aim was to evaluate the shelf life and the dissolving and antibacterial properties of a neutralized 2.5% NaOCl solution. The loss of available chlorine and the pH of the neutralized 2.5% NaOCl solution were recorded to determine its shelf life. The dissolving action on bovine dental pulp was assessed measuring weight loss, pH variation, and decrease in available chlorine content. The antibacterial activity was evaluated on artificially infected human teeth. The roots were endodontically prepared, sterilized, and inoculated with Enterococcus faecalis before irrigation with the neutralized solution. The presence of intracanal bacteria after irrigation was recorded. The neutralized solution presented a shelf life of 2 hours, dissolving capacities equivalent to control for the first 5 minutes, and a better antibacterial efficiency. The neutralized 2.5% NaOCl solution must be used within 2 hours after mixing, should be frequently renewed to maintain its dissolving capacities, and presented enhanced antibacterial properties.

  8. Some magnetic resonance properties of solutions of sodium in liquid ammonia; Contribution a l'etude des solutions de sodium dans l'ammoniac liquide par resonance magnetique

    Energy Technology Data Exchange (ETDEWEB)

    Lambert, C. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1968-02-01

    Dilute solutions of sodium in liquid ammonia are studied by the mean of dynamic polarization techniques, and with the aid of Becker Lindquist and Alder model. Paramagnetic shifts are computed as a function of the 'average spin density', for each of the nuclear spin system. The nuclear contributions to the Overhauser shift are computed in the same way. A theoretical study of the main relaxation processes is carried out for each of the nuclear spin system and for the electronic spin system. The dynamic polarization experiments consist in classical measurement of the Overhauser enhancement for nitrogen, and in direct measurements of nitrogen Knight shift and nuclear contributions to the Overhauser shift by the mean of double irradiation techniques. The results show that, in dilute solutions, the relaxation of nitrogen arises from quadrupole interaction and from hyperfine interaction with unpaired electrons. Both interactions are of the same order of magnitude. Overhauser shift measurements show that the spin density is negative at the proton site, in agreement with Hughes results. (author) [French] Les solutions diluees de sodium dans l'ammoniac sont etudiees au moyen des techniques de la polarisation dynamique, sur la base du modele de Becker Lindquist et Aider. Les deplacements paramagnetiques des raies de resonance nucleaire des differents noyaux sont analyses en faisant appel a la notion de ''densite moyenne de spin'' introduite par l'auteur; et les differentes contributions nucleaires au deplacement d'Overhauser sont calculees en fonction de cette meme grandeur. Une etude theorique de la relaxation de chaque systeme de spin permet d'evaluer l'importance relative des differents mecanismes mis en jeu. Les experiences de polarisation dynamique effectuees au cours de ce travail consistent en mesures classiques de l'effet Overhauser sur l'azote, d'une part, et en la mise en oeuvre de techniques

  9. Enhanced decolorization of methyl orange in aqueous solution using iron-carbon micro-electrolysis activation of sodium persulfate.

    Science.gov (United States)

    Li, Peng; Liu, Zhipeng; Wang, Xuegang; Guo, Yadan; Wang, Lizhang

    2017-08-01

    Reactivity of sodium persulfate (PS) in the decolorization of methyl orange (MO) in aqueous solution using an iron-carbon micro-electrolysis (ICE) method was investigated. The effects of sodium persulfate doses, pH, Fe-to-C mass ratios, initial MO concentration as well as the reaction temperature were comprehensively studied in batch experiments. The ICE-PS coupled process was more suitable for wide ranges of pH, initial MO concentration and reaction temperature, accompanied by the reduction of Fe compared ICE. The MO removal efficiency improved substantially by ICE-PS technique, 76.03% for ICE and 91.27% for ICE-PS at experimental conditions of pH 3.0, Fe-to-C mass ratio 3:1, PS addition 10 mM and initial MO concentration 0.61 mM. Furthermore, the biodegradability index (BI) dramatically increased from 0.26 to 0.65. The binary hydroxyl and sulfate radicals that non-selectively degrade MO to the derivatives with small molecules are ascribed to ICE-PS method as detected by the UV-vis spectra. The PS activation resource was Fe 2+ through the hydroxyl radical quenching reaction by the additive tert-butanol (TBA). This study provides an in-depth theoretical understanding of the development and wide commercial application of the ICE technology to refractory industrial dye wastewater treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Stability-Indicating HPLC Method for Simultaneous Determination of Chloramphenicol, Dexamethasone Sodium Phosphate and Tetrahydrozoline Hydrochloride in Ophthalmic Solution.

    Science.gov (United States)

    AlAani, Hashem; Alnukkary, Yasmin

    2016-03-01

    A simple stability-indicating RP-HPLC assay method was developed and validated for quantitative determination of Chloramphenicol, Dexamethasone Sodium Phosphate and Tetrahydrozoline Hydrochloride in ophthalmic solution in the presence of 2-amino-1-(4-nitrophenyl)propane-1,3-diol, a degradation product of Chloramphenicol, and Dexamethasone, a degradation product of Dexamethasone Sodium Phosphate. Effective chromatographic separation was achieved using C18 column (250 mm, 4.6 mm i.d., 5 μm) with isocratic mobile phase consisting of acetonitrile - phosphate buffer (pH 4.0; 0.05 M) (30:70, v/v) at a flow rate of 1 mL/minute. The column temperature was maintained at 40°C and the detection wavelength was 230 nm. The proposed HPLC procedure was statistically validated according to the ICH guideline, and was proved to be stability-indicating by resolution of the APIs from their forced degradation products. The developed method is suitable for the routine analysis as well as stability studies.

  11. The removal of Tartrazine dye by modified Alumina with sodium dodecyl sulfate from aqueous solutions: equilibrium and thermodynamic studies

    Directory of Open Access Journals (Sweden)

    A. Parchebaf Jadid

    2017-11-01

    Full Text Available Edible colors are materials which in the case of adding to food and drinks cause transferring color to them. Most of these colors are not acceptable in terms of applying in human food and underlies various diseases like gastrointestinal disorders, renal, liver and blood toxicity. The goal of this study was investigating the efficiency of improved alumina by sodium dodecyl sulfate (SDS in eliminating Tartrazine from aqueous environments. In this research, the impact of effective parameters such as initial concentration of Tartrazine, time, pH, alumina dose and SDS value were studied in order to approach an optimal condition for eliminating the color. Also, absorption behavior was evaluated by Freundlich and Langmuir isotherms. The highest efficiency of Tartrazine elimination in the solution resulted in optimal pH of 2, the amount of adsorbent 1.5 g/L, 16 min duration and value 0.04 SDS g/l which was obtained for dye concentration 5 mg/L about 94.13%. Also, results suggested that Tartrazine absorption follows Langmuir isotherm (R2 = 0.9867. Obtained results from thermodynamic studies such as Gibbs free energy (-5.728 Kj/mol and enthalpy (-85.86 Kj/mol and entropy (-271.102 J/mol.K also suggested that the absorption process was exothermic. The results of this research suggested that improved alumina by sodium dodecyl sulfate had a relative good capability in Tartrazine elimination from aqueous environments. Thus

  12. Criterion for selection the optimal physical and chemical properties of cobalt aluminate powder used in investment casting process

    Directory of Open Access Journals (Sweden)

    M. Zielińska

    2009-07-01

    Full Text Available The aim of this work was to determine physical and chemical properties of cobalt aluminate (CoAl2O4 modifiers produced by different companies and the influence of different types of modifiers on the grain size of high temperature creep resisting superalloys: Inconel 713C, René 77 and MAR-M 509.The first stage of the research work took over the investigations of physical and chemical properties of cobalt aluminate manufactured by three different companies: Remet, Mason Color and Permedia Lublin. There were determined the grain size distribution of cobalt aluminate powder, the average diameter and morphology of powder particles, phase composition, as well as sodium and cobalt content, pH value of water suspension and the bulk density. In the next step, the ceramic moulds were made with different kind of cobalt aluminate (Mason Color, Remet, Permedia Lublin and its concentration (0, 5% in the primary slurry. The samples of stepped shape were poured in the ceramic moulds prepared earlier. The average grain size of the γ phase was determined on the stepped samples.It was established that physical and chemical properties of cobalt aluminate modifier are different up to the manufacturer. For example the modifiers manufactured by Permedia; Mason Color and Remet companies have different the average diameter of particles- 68,050d; 49,6 i 36,7μm, and also cobalt content _CoC=32,53%; 39,43% i 34,79%mass, respectively. The grain size of γ matrix of superalloys depends on the kind of used inoculant. The best grain refinement of the matrix of superalloys: Inconel 713C, René 77 and MAR-M 509 was observed in the castings modified with the use of Mason Color modifier. On the grounds of literature data and obtained results it was established that the cobalt content of cobalt aluminate influences the intensity of nucleation process during the crystallization of superalloys: Inconel 713C, René 77 i MAR-M 509.

  13. Use of 8.4% Sodium Bicarbonate in Buffering Commonly Administered Vancomycin Hydrochloride Solutions for Use with Midline or Peripheral Line Catheters.

    Science.gov (United States)

    Puertos, Enrique; Spencer, Melissa

    2015-01-01

    The primary objective of this study was to evaluate the use of 8.4% sodium bicarbonate in the buffering of commonly administered vancomycin hydrochloride solutions for use with midline or peripheral line catheters. Nine admixtures of vancomycin hydrochloride were aseptically prepared for this study. Vancomycin hydrochloride solutions were prepared in triplicates in the following strengths, 1 gram, 2 grams, and 3 grams, which were added to 250-mL bags of sodium chloride 0.9% injection (with overfill). To each prepared solution of vancomycin hydrochloride, 0.5 mL of 8.4% sodium bicarbonate was added. The pH was measured to obtain a baseline level. At day 9, the pH of each sample was measured and compared to those at baseline. The osmolality of each sample was also measured. There was no statistical difference in the pH at baseline and at day 9 (α = 0.05, P = 0.347). A solution of vancomycin hydrochloride that is compounded in 250 mL of sodium chloride 0.9% injection (including overfill) and buffered with 0.5 mL of 8.4% sodium bicarbonate maintained a pH in the range of 5 to 9 and an osmolality in the range of 150 mOsm/kg to 500 mOsm/kg.

  14. Sodium diethyldithiocarbamate as a corrosion inhibitor of cold rolled steel in 0.5 M hydrochloric acid solution

    International Nuclear Information System (INIS)

    Li Lei; Qu Qing; Bai Wei; Yang Fachang; Chen Yajun; Zhang Shiwen; Ding Zhongtao

    2012-01-01

    Graphical abstract: Relationship between corrosion current density (i corr ), inhibition efficiency (η p ) and temperature with and without DDTC. (solid symbols: i corr , open symbols: η p .) Highlights: ► DDTC can acts as a cathodic type inhibitor for CRS in HCl solution. ► The activation energy, E a , increases with increasing the concentration of DDTC. ► The driving force for adsorption of DDTC on CRS is the increase in entropy. ► DDTC adsorbs on CRS surface probably by chemisorption and physisorption. ► Variation of DDTC results in different effect for time on inhibition efficiency. - Abstract: Sodium diethyldithiocarbamate (DDTC) as a corrosion inhibitor for cold rolled steel (CRS) in 0.5 M HCl solution was investigated by Tafel polarization and electrochemical impedance spectroscopy (EIS). All the data indicate that DDTC can inhibit the corrosion of CRS in HCl solution. Polarization data show that DDTC mainly acts as a good inhibitor though it can accelerate the anodic reaction somewhat. Adsorption of DDTC is found to follow the Langmuir adsorption isotherm. Thermodynamic analysis indicates that both physisorption and chemisorption probably occur in the adsorption process. SEM and FTIR results further validate that DDTC can adsorb on CRS surface.

  15. Influence of Sodium Bisulfite and Lithium Bromide Solutions on the Shape Fixation of Camel Guard Hairs in Slenderization Process

    Directory of Open Access Journals (Sweden)

    Xueliang Xiao

    2016-01-01

    Full Text Available Outstanding performance of natural camel hair has attracted much attention on the effective use of such specialty fiber to apparel textiles. In this paper, sodium bisulfide (SB and lithium bromide (LB solutions were used to process the camel guard hair before its slenderization. It is found that camel guard hair processed by SB solution shows the highest breaking elongation (~140% due to the breakage of disulfide bonds (reflected by Raman spectra. LB ions result in the disruption of hair crystalline phase with slight benefit to the slenderization (determined by X-ray diffraction and differential scanning calorimetry. IR spectra indicate that hydrogen bonds of camel guard hair act as fixation switch in the programmed tensile test. It is discovered that guard hair reveals the best water-induced shape memory with 90% of stretching shape recovery, whereas the value remained to be 70% and 60% for hair processed by LB and SB solutions after breaking partial crystalline phase and disulfide cross-links separately (polymer net-points. The poorer shape memory of processed guard hair benefits its slenderization for more stable fixation of stretched length.

  16. Effect of immersion disinfection of alginate impressions in sodium hypochlorite solution on the dimensional changes of stone models.

    Science.gov (United States)

    Hiraguchi, Hisako; Kaketani, Masahiro; Hirose, Hideharu; Yoneyama, Takayuki

    2012-01-01

    This study investigated the effect of the immersion of alginate impressions in 0.5% sodium hypochlorite solution for 15 min on the dimensional changes of stone models designed to simulate a sectional form of a residual ridge. Five brands of alginate impression materials, which underwent various dimensional changes in water, were used. A stone model made with an impression that had not been immersed was prepared as a control. The immersion of two brands of alginate impressions that underwent small dimensional changes in water did not lead to serious deformation of the stone models, and the differences in the dimensional changes between the stone models produced with disinfected impressions and those of the control were less than 15 µm. In contrast, the immersions of three brands of alginate impressions that underwent comparatively large dimensional changes in water caused deformation of the stone models.

  17. AFM study of the early corrosion of a high strength steel in a diluted sodium chloride solution

    International Nuclear Information System (INIS)

    Sanchez, Javier; Fullea, Jose; Andrade, Carmen; Gaitero, Juan J.; Porro, Antonio

    2008-01-01

    The high strength steels employed as reinforcement in pre-stressed concrete structures are drawn wire steels of eutectoid composition with a pearlitic microstructure. This work is focused on the study, by atomic force microscopy, of the early stages of the corrosion of such steels as a consequence of their exposition to a sodium chloride solution. The obtained images show the pearlitic microstructure of the steel, with a preferential attack of the ferrite phase and the cementite acting as a cathode. The corrosion rate was determined by calculating the amount of material lost from a roughness analysis. The obtained results are in good agreement with the predictions of Galvelel's theory, according to which the corrosion rate slows down as the pit depth increases

  18. Sodium concentration in home made salt – sugar – solution (sss ...

    African Journals Online (AJOL)

    In a cohort of 210 young mothers, selected through cluster sampling technique from Ogida health district of Egor Local Government Area of Edo State, the electrolyte concentration of prepared salt-sugar-solutions (SSS) were evaluated. This was predicated on the need to determine the effects of introduction of various ...

  19. Synthesis of magnesium aluminate spinel by periclase and alumina chlorination

    International Nuclear Information System (INIS)

    Orosco, Pablo; Barbosa, Lucía; Ruiz, María del Carmen

    2014-01-01

    Highlights: • Use of chlorination for the synthesis of magnesium aluminate spinel. • The reagents used were alumina, periclase and chlorine. • Isothermal and non-isothermal assays were performed in air and Cl 2 –N 2 flows. • The chlorination produced magnesium aluminate spinel at 700 °C. • Selectivity of the chlorination reaction to obtain spinel is very high. - Abstract: A pyrometallurgical route for the synthesis of magnesium aluminate spinel by thermal treatment of a mechanical mixture containing 29 wt% MgO (periclase) and 71 wt% Al 2 O 3 (alumina) in chlorine atmosphere was developed and the results were compared with those obtained by calcining the same mixture of oxides in air atmosphere. Isothermal and non-isothermal assays were performed in an experimental piece of equipment adapted to work in corrosive atmospheres. Both reagents and products were analyzed by differential thermal analysis (DTA), X-ray diffraction (XRD) and X-ray fluorescence (XRF). Thermal treatment in Cl 2 atmosphere of the MgO–Al 2 O 3 mixture produces magnesium aluminate spinel at 700 °C, while in air, magnesium spinel is generated at 930 °C. The synthesis reaction of magnesium aluminate spinel was complete at 800 °C

  20. Synthesis of magnesium aluminate spinel by periclase and alumina chlorination

    Energy Technology Data Exchange (ETDEWEB)

    Orosco, Pablo, E-mail: porosco@unsl.edu.ar [Instituto de Investigaciones en Tecnología Química (INTEQUI), Chacabuco y Pedernera, San Luis (Argentina); Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis Chacabuco y Pedernera, San Luis (Argentina); Barbosa, Lucía [Instituto de Investigaciones en Tecnología Química (INTEQUI), Chacabuco y Pedernera, San Luis (Argentina); Instituto de Ciencias Básicas (ICB), Universidad Nacional de Cuyo Parque General San Martín, Mendoza (Argentina); Ruiz, María del Carmen [Instituto de Investigaciones en Tecnología Química (INTEQUI), Chacabuco y Pedernera, San Luis (Argentina); Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis Chacabuco y Pedernera, San Luis (Argentina)

    2014-11-15

    Highlights: • Use of chlorination for the synthesis of magnesium aluminate spinel. • The reagents used were alumina, periclase and chlorine. • Isothermal and non-isothermal assays were performed in air and Cl{sub 2}–N{sub 2} flows. • The chlorination produced magnesium aluminate spinel at 700 °C. • Selectivity of the chlorination reaction to obtain spinel is very high. - Abstract: A pyrometallurgical route for the synthesis of magnesium aluminate spinel by thermal treatment of a mechanical mixture containing 29 wt% MgO (periclase) and 71 wt% Al{sub 2}O{sub 3} (alumina) in chlorine atmosphere was developed and the results were compared with those obtained by calcining the same mixture of oxides in air atmosphere. Isothermal and non-isothermal assays were performed in an experimental piece of equipment adapted to work in corrosive atmospheres. Both reagents and products were analyzed by differential thermal analysis (DTA), X-ray diffraction (XRD) and X-ray fluorescence (XRF). Thermal treatment in Cl{sub 2} atmosphere of the MgO–Al{sub 2}O{sub 3} mixture produces magnesium aluminate spinel at 700 °C, while in air, magnesium spinel is generated at 930 °C. The synthesis reaction of magnesium aluminate spinel was complete at 800 °C.

  1. The crevice corrosion behaviour of stainless steel in sodium chloride solution

    International Nuclear Information System (INIS)

    Hu Qian; Zhang Guoan; Qiu Yubin; Guo Xingpeng

    2011-01-01

    Highlights: → There are three stages in crevice corrosion of 13Cr stainless steel in NaCl solution. → The decrease of crevice thickness shortens the incubation period of crevice corrosion. → The incubation period of crevice corrosion prolongs as the increase of the area ratio. → Corrosion develops preferentially at crevice bottom and hydrogen reduction occurs inside the crevice. → Crevice corrosion of 13Cr stainless steel in NaCl solution follows the passive dissolution mechanism. - Abstract: The crevice corrosion behaviour of 13Cr stainless steel in NaCl solution was investigated mainly by electrochemical noise measurements, considering the influences of the crevice opening dimension (a) and the area ratio of the electrode outside the crevice to the one inside the crevice (r). Results show that the increase of r value prolongs the incubation period of crevice corrosion, but crevice corrosion develops rapidly once the crevice corrosion occurs. The crevice corrosion develops preferentially at the crevice bottom and then spreads to the whole electrode surface. Proton could reduce on the uncorroded area and hydrogen bubbles form inside the crevice.

  2. Effect of sodium phosphate salts on the thermodynamic properties of aqueous solutions of poly(ethylene oxide) 6000 at different temperatures

    International Nuclear Information System (INIS)

    Sadeghi, Rahmat; Hosseini, Rahim; Jamehbozorg, Bahman

    2008-01-01

    Precise density, sound velocity, water activity, and phase diagram measurements have been carried out on polyethylene oxide (PEO) in aqueous solutions of sodium di-hydrogen phosphate, di-sodium hydrogen phosphate, and tri-sodium phosphate over a range of temperatures at atmospheric pressure. The experimental density and sound velocity data are used to calculate the apparent specific volume and isentropic compressibility as a function of temperature and concentration. It was found that both of the apparent specific volume and isentropic compressibility of PEO in aqueous solutions increase by increasing temperature and charge on the anion of electrolytes. The results show that the slope of constant water activity lines increased with increasing the temperature and charge on the anion of electrolytes and the vapour pressure depression for an aqueous (PEO + sodium phosphate) system is more than the sum of those for the corresponding binary solutions. Furthermore, the effect of temperature and type of anion of salt on the salting-out effect of polyethylene oxide by sodium phosphate salts has been studied

  3. Effect of sodium phosphate salts on the thermodynamic properties of aqueous solutions of poly(ethylene oxide) 6000 at different temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Sadeghi, Rahmat [Department of Chemistry, University of Kurdistan, Sanandaj (Iran, Islamic Republic of)], E-mail: rahsadeghi@yahoo.com; Hosseini, Rahim; Jamehbozorg, Bahman [Department of Chemistry, University of Kurdistan, Sanandaj (Iran, Islamic Republic of)

    2008-09-15

    Precise density, sound velocity, water activity, and phase diagram measurements have been carried out on polyethylene oxide (PEO) in aqueous solutions of sodium di-hydrogen phosphate, di-sodium hydrogen phosphate, and tri-sodium phosphate over a range of temperatures at atmospheric pressure. The experimental density and sound velocity data are used to calculate the apparent specific volume and isentropic compressibility as a function of temperature and concentration. It was found that both of the apparent specific volume and isentropic compressibility of PEO in aqueous solutions increase by increasing temperature and charge on the anion of electrolytes. The results show that the slope of constant water activity lines increased with increasing the temperature and charge on the anion of electrolytes and the vapour pressure depression for an aqueous (PEO + sodium phosphate) system is more than the sum of those for the corresponding binary solutions. Furthermore, the effect of temperature and type of anion of salt on the salting-out effect of polyethylene oxide by sodium phosphate salts has been studied.

  4. Electrochemical deposition of silver nanostructures from aqueous solutions in the presence of sodium polyacrylate

    OpenAIRE

    Topchak, Roman; Okhremchuk, Yevhen; Kuntyi, Orest

    2013-01-01

    The silver nanostructures obtaining was investigated by electrochemical deposition from aqueous solutions ((1?10) mM AgNO3 + 50 m? NaPA) onto graphite substrate. The influence of the concentration of silver ions and cathodic potential values in the range E = -0,2 ... -1,0 V on surface filling degree and geometry of silver particles was (had been) studied. It is shown, the discrete silver particles ranging in size from 50 to 400 nm with a uniform distribution on the surface of the substrate...

  5. Inefficacy of osmotic backwash induced by sodium chloride salt solution in controlling SWRO membrane fouling

    Science.gov (United States)

    Farooque, A. Mohammed; Al-Jeshi, Subhi; Saeed, Mohamed O.; Alreweli, Ali

    2014-12-01

    A study was conducted to evaluate the efficacy of osmotic backwash induced by high salt (NaCl) concentration solution on feed side of seawater reverse osmosis (SWRO) membranes, online and offline, in controlling membrane fouling and therefore minimizing/eliminating the need for chemical cleaning. SWRO membranes were deliberately fouled by feeding seawater from an open intake located on the Arabian Gulf Coast without dosing chemicals. The fouled membranes were subjected to offline cleaning with the salt solution of up to 25 % concentration. Despite the partial removal of foulants from the membrane surface, SWRO membrane performance could not be restored, indicating the ineffectiveness of osmotic backwash in aiding offline salt cleaning. Similarly, online osmotic backwash was found to be not only ineffective in removing foulants from membrane surfaces but actually increased the fouling rate, as indicated by faster fouling rates compared to other cases. Although the driving force required for the osmotic backwash existed, the generated back flow proved to be insufficient to detach foulants from membrane surfaces. During the study period, the average SWRO membrane flux was maintained between 19 and 23 LMH, whereas the average generated back flow flux by high salt concentration solution was only 11 LMH, which was not adequate to remove foulants from membrane surfaces. Moreover, it seems that the membrane configuration as well as inherent microstructure of SWRO membrane places certain constraints on the osmotic backwash process and renders osmotic backwash ineffective in tackling SWRO membrane fouling. Hence, chemical cleaning is essential to restore SWRO membrane performance whenever fouling occurs, and the use of highly concentrated salt solution does not have any significant benefit. Membrane autopsy revealed only an insignificant accumulation of biofouling layer despite the absence of disinfection. However, it was shown that culturable biofilm bacteria species

  6. Investigation of interaction of cadmium nitrate with sodium hydroxide in aqueous solutions

    International Nuclear Information System (INIS)

    Gyunner, Eh.A.; Mel'nichenko, L.M.; Yakhkind, N.D.; Vel'mozhnyj, I.S.

    1984-01-01

    The methods of physiochemical analysis (measurement of Cd 2+ and OH - residual concentrations, refraction index and liquid phase density) as well as X-ray phase analysis of precipitations have been used to study the interaction of Cd(NO 3 ) 2 with NaOH in isomolar series of mixtures of reagent solutions and in mixtures with constant content of Cd 2+ ions at variable OH - ion concentration. It has been found that depending on reagents relations weakly-soluble interaction products are Cd 3 (OH) 5 NO 3 or Cd(OH) 2

  7. Effect of plastic deformation on Corrosion of cadmium in 0.1 m sodium Sulphate solution

    OpenAIRE

    Kandeil, A. Y. [عبد الرزاق يوسف قنديل; El-Gaber, A. S.; Mourad, M. Y.

    1993-01-01

    The present investigation was carried out to study the influence of prior plastic deformation and surface finish on the corrosion behaviour of pure cadmium in 0.1 M Na2SC>4 solution at 25° C. Cylindrical specimens were deformed by compression to different levels of deformation up to 90% reduction in height (RH). Three surface finishes were examined, namely, 120, 320 and 600 grits. The results obtained indicate that the cathodic corrosion rate decreases with deformation up to 30-60% RH, depend...

  8. B-site substituted solid solutions on the base of sodium-bismuth titanate

    Directory of Open Access Journals (Sweden)

    V. M. Ishchuk

    2016-12-01

    Full Text Available The paper presents results of studies of the formation of phases during the solid-state synthesis in the [(Na0.5Bi0.50.80Ba0.20](Ti1–yByO3 system of solid solutions with B-site substitutions. The substitutions by zirconium, tin and ion complexes (In0.5Nb0.5 and (Fe0.5Nb0.5 have been studied. It has been found that the synthesis is a multi-step process associated with the formation of a number of intermediate phases (depending on the compositions and calcination temperatures. Single-phase solid solutions have been produced at the calcination temperatures in the interval 1000–1100∘C. An increase in the substituting ions concentration leads to a linear increase of the crystal cell size. At the same time, the tolerance factor gets reduced boosting the stability of the antiferroelectric phase as compared to that of the ferroelectric phase.

  9. Standard practice for exposure of metals and alloys by alternate immersion in neutral 3.5% Sodium Chloride solution

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1999-01-01

    1.1 This practice covers procedures for making alternate immersion stress corrosion tests in 3.5 % sodium chloride (NaCl) (). It is primarily for tests of aluminum alloys (Test Method G 47) and ferrous alloys, but may be used for other metals exhibiting susceptibility to chloride ions. It sets forth the environmental conditions of the test and the means for controlling them. Note 1 Alternate immersion stress corrosion exposures are sometimes made in substitute ocean water (without heavy metals) prepared in accordance with Specification D 1141. The general requirements of this present practice are also applicable to such exposures except that the reagents used, the solution concentration, and the solution pH should be as specified in Specification D 1141. 1.2 This practice can be used for both stressed and unstressed corrosion specimens. Historically, it has been used for stress-corrosion cracking testing, but is often used for other forms of corrosion, such as uniform, pitting, intergranular, and galvanic. ...

  10. Comparison of physical and mechanical properties of microwave-polymerized acrylic resin after disinfection in sodium hypochlorite solutions.

    Science.gov (United States)

    Paranhos, Helena de Freitas Oliveira; Davi, Letícia Resende; Peracini, Amanda; Soares, Rafael Bellini; Lovato, Cláudia Helena da Silva; Souza, Raphael Freitas de

    2009-01-01

    This study evaluated the color stability, surface roughness and flexural strength of a microwave-polymerized acrylic resin after immersion in sodium hypochlorite (NaOCl), simulating 20 min of disinfection daily during 180 days. Forty disk-shaped (15 x 4 mm) and 40 rectangular (65 x 10 x 3 mm) specimens were prepared with a microwave-polymerized acrylic resin (Onda-Cryl). Specimens were immersed in either 0.5% NaOCl, 1% NaOCl, Clorox/Calgon and distilled water (control). Color measurements were determined by a portable colorimeter. Three parallel lines, separated by 1.0 mm, were registered on each specimen before and after immersion procedures to analyze the surface roughness. The flexural strength was measured using a 3-point bending test in a universal testing machine with a 50 kgf load cell and a crosshead speed of 1 mm/min. Data were analyzed statistically by ANOVA and Tukey's test (alpha=0.05). There was no statistically significant differences (p>0.05) among the solutions for color, surface roughness and flexural strength. It may be concluded that immersion in NaOCl solutions simulating short-term daily use during 180 days did not influence the color stability, surface roughness and flexural strength of a microwave-polymerized acrylic resin.

  11. Bulk Group-III Nitride Crystal Growth in Supercritical Ammonia-Sodium Solutions

    Science.gov (United States)

    Griffiths, Steven Herbert

    Gallium nitride (GaN) and its alloys with indium nitride (InGaN) and aluminum nitride (AlGaN), collectively referred to as Group-III Nitride semiconductors, have enabled white solid-state lighting (SSL) sources and power electronic devices. While these technologies have already made a lasting, positive impact on society, improvements in design and efficiency are anticipated by shifting from heteroepitaxial growth on foreign substrates (such as sapphire, Si, SiC, etc.) to homoepitaxial growth on native, bulk GaN substrates. Bulk GaN has not supplanted foreign substrate materials due to the extreme conditions required to achieve a stoichiometric GaN melt (temperatures and pressures in excess of 2200°C and 6 GPa, respectively). The only method used to produce bulk GaN on an industrial scale is hydride vapor phase epitaxy (HVPE), but the high cost of gaseous precursors and relatively poor crystal quality have limited the adoption of this technology. A solution growth technique known as the ammonothermal method has attracted interest from academia and industry alike for its ability to produce bulk GaN boules of exceedingly high crystal quality. The ammonothermal method employs supercritical ammonia (NH3) solutions to dissolve, transport, and crystallize GaN. However, ammonothermal growth pressures are still relatively high (˜200 MPa), which has thus far prevented the acquisition of fundamental crystal growth knowledge needed to efficiently (i.e. through data-driven approaches) advance the field. This dissertation focused on addressing the gaps in the literature through two studies employing in situ fluid temperature analysis. The first study focused on identifying the solubility of GaN in supercritical NH3-Na solutions. The design and utilization of in situ and ex situ monitoring equipment enabled the first reports of the two-phase nature of supercritical NH3-Na solutions, and of Ga-alloying of Ni-containing autoclave components. The effects of these error sources on

  12. Effects of type of diet on pharmacokinetics of levothyroxine sodium oral solution.

    Science.gov (United States)

    Iemura, Ryuji; Toyota, Masanori; Micallef, Mark J

    2013-06-01

    The pharmacokinetics of serum total thyroxine concentration (TT4) in euthyroid dogs was studied after concomitant administration of a levothyroxine oral solution with different types of dry diet. Mixing levothyroxine with different types of dry diet did not have any effect on TT4 pharmacokinetics in the dogs (Cmax 50.6 nmol/L, tmax 4.0 h and AUC 517 nmol h/L). This finding indicates that changing from one diet to another during levothyroxine-replacement therapy should not impact therapeutic effectiveness, and should be helpful for improvement of compliance with thyroid hormone replacement therapy in dogs treated for life with this replacement therapy. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Corrosion behavior of magnesium-graphene composites in sodium chloride solutions

    Directory of Open Access Journals (Sweden)

    Muhammad Rashad

    2017-09-01

    Full Text Available Coating of graphene and graphene/polymer composites on metals improves the corrosion resistance of metal substrates. On other hand, graphene embedded inside metal (especially Mg matrices increases or decreases corrosion, is a crucial factor and must be explored. In present study, electrochemical behaviors of magnesium alloys (AZ31 and AZ61 and their composites reinforced with graphene nanoplatelets (GNPs were carried out in 3.5% NaCl solution by polarization method. The surface morphology of composites before and after corrosion tests were analyzed using scanning electron microscopy. Experimental results revealed that presence of graphene nanoplatelets in different matrices decrease corrosion resistance of composites. This may be attributed to presence of graphene nanoplatelets which activates the corrosion of magnesium/alloys due to the occurrence of galvanic corrosion and this effect increases with increasing graphene nanoplatelets content. Further, an appropriate model describing the corrosion mechanism was proposed.

  14. XPS characterization of the anodic oxide film formed on uranium metal in sodium hydroxide solution

    International Nuclear Information System (INIS)

    Fu Xiaoguo; Wang Xiaolin; Guo Huanjun; Wang Qingfu; Zhao Zhengping; Zhong Yongqiang

    2002-01-01

    X-ray photoelectron spectroscopy (XPS) is used to examine the anodic oxide film formed on uranium metal in 0.8 mol/L NaOH solution. The U4f 7/2 fitting spectra suggests that the anodic oxide film is composed of uranium trioxide and a small amount of UO 2+x . Under UHV condition, the U4f peak shifts to the lower binding energy, while a gradual increase in the intensity of U5f peak and the broad of U4f peak are also observed. All of these changes are due to reduction of uranium trioxide in the anodic oxide film. XPS quantitative analysis confirms the occurrence of reduction reaction

  15. Physiological strains of wearing aluminized and non-aluminized firefighters' protective clothing during exercise in radiant heat.

    Science.gov (United States)

    Chou, Chinmei; Tochihara, Yutaka; Ismail, Mohamed Saat; Lee, Joo-Young

    2011-01-01

    This study examined the influences of aluminized (Type A) and non-aluminized firefighters' protective clothing (Type B, C, D and CON) on physiological and subjective responses in radiant heat. Total clothing weight was 6.24, 6.38, 6.06, 5.76 and 3.82 kg for Type A, B, C, D and CON, respectively. Eight firefighters performed exercise at an air temperature of 30°C with 50%RH. Three bouts of 10 min-bicycle exercise in radiant heat (a globe temperature of 70°C) was spaced by a 10 min rest with no radiant heat. Results showed that rectal temperature, mean skin temperature, heart rate, and body weight loss were significantly greater in Type A than in other types (pradiant heat. Therefore, it is suggested that the safe upper limits while wearing aluminized firefighters' clothing should be distinguished from those for typical firefighters' protective clothing.

  16. A prospective study of bowel preparation for colonoscopy with polyethylene glycol-electrolyte solution versus sodium phosphate in Lynch syndrome: a randomized trial

    NARCIS (Netherlands)

    Vugt-van Pinxteren, M.W.J. van; Kouwen, M.C.A. van; Oijen, M.G. van; van Achterberg, T.; Nagengast, F.M.

    2012-01-01

    Lynch gene carriers undergo regular surveillance colonoscopies. Polyethylene glycol-electrolyte solution (PEG) is routinely prescribed for bowel cleansing, but often poorly tolerated by patients. Sodium phosphate (NaP) may be an alternative. Prospective and random comparison of bowel preparation

  17. SODIUM DI-N-DODECYL PHOSPHATE VESICLES IN AQUEOUS-SOLUTION - EFFECTS OF ETHANOL, PROPANOL, AND TETRAHYDROFURAN ON THE GEL TO LIQUID-PHASE TRANSITION

    NARCIS (Netherlands)

    BLANDAMER, MJ; BRIGGS, B; BUTT, MD; WATERS, M; CULLIS, PM; ENGBERTS, JBFN; HOEKSTRA, D; MOHANTY, RK

    1994-01-01

    For aqueous solutions containing vesicles formed by sodium di-n-dodecyl phosphate, the gel to liquid-crystal transition occurs near 35 degrees C, the temperature T-m. When ethanol is added, T-m decreases, but the scan shows evidence of several transitions as more alcohol is added. The effect of

  18. Free available chlorine concentration in sodium hypochlorite solutions obtained from dental practices and intended for endodontic irrigation: are the expectations true?

    NARCIS (Netherlands)

    van der Waal, S.; Connert, T.; Laheij, A.; de Soet, J.; Wesselink, P.

    2014-01-01

    Objective: Sodium hypochlorite (NaOCl) is an important tool in root canal disinfection although it is well known that the shelf-life of NaOCl is limited. In this study, NaOCl solutions that were collected from dental practices and were intended for endodontic irrigation were investigated to see

  19. SODIUM DODECYL-SULFATE INDUCED ENHANCEMENT OF THE VISCOSITY AND VISCOELASTICITY OF AQUEOUS-SOLUTIONS OF POLY(ETHYLENE OXIDE) - A RHEOLOGICAL STUDY ON POLYMER MICELLE INTERACTION

    NARCIS (Netherlands)

    BRACKMAN, JC

    A large enhancement of the viscosity and the viscoelasticity of aqueous solutions of high molecular weight poly(ethylene oxide) (PEO) has been observed upon addition of sodium dodecyl sulfate (SDS). The changes in apparent viscosity, in the parameters for the power law model of non-Newtonian

  20. Polystyrene-Poly(sodium methacrylate) Amphiphilic Block Copolymers by ATRP : Effect of Structure, pH, and Ionic Strength on Rheology of Aqueous Solutions

    NARCIS (Netherlands)

    Raffa, Patrizio; Brandenburg, Piter; Wever, Diego A. Z.; Broekhuis, Antonius A.; Picchioni, Francesco

    2013-01-01

    Three well-defined polystyrene-poly(sodium methacrylate) amphiphilic block copolymers characterized by different molecular architecture (diblock, triblock, and four-arm star) have been synthesized by ATRP. The rheology of their water solutions has been evaluated by measuring dynamic moduli and shear

  1. Antibacterial efficacy of lavandula officinalis extract, sodium hypochlorite and chlorhexidine gluconate solutions as root canal irrigations: A comparative analysis

    Directory of Open Access Journals (Sweden)

    pouya Mehmandoust

    2016-03-01

    Full Text Available Introduction: This in vitro study aimed to compare the antimicrobial effect of lavandula -0fficinalis extract, with sodium hypochlorite (NaOCL and chlorhexidine gluconate (CHX, as root canal irrigants, on Enterococcus faecalis (EF. Materials &Methods: Seventy five extracted single-rooted premolars were selected. Root canals were prepared using rotary ProTaper system and were infected with the culture of E. faecalis. Specimens were randomly divided into five groups (n = 15, Group 1, 2: lavandula extracts (0.26 and 0.52 mg/mL, Group 3: 2.5%NaOCL, Group 4: 2%CHX, Group 5: Normal Saline. Irrigation was performed for each group for 5, 10 and 15 min. The viable bacteria obtained by collecting the canal dentin chips. Data analysis was performed with Kruskal-Wallis and Mann-Whitney u tests. Results: The mean number of viable bacteria was significantly reduced after 5 min exposure to lavandula solutions (p<0.05. A significant difference also existed between different times in the NaOCL group, being significant between 5 and 15 min (p<0.05, but there was no significant difference between different times in the CHX group. Comparison of the mean number of viable bacteria between different groups at different exposure times revealed that the difference between lavandula and NaOCL solutions with CHX was significant at 5 and 10 min (p<0.05, however, no statistically significant difference was observed between lavandula solutions and NaOCL. Conclusion: lavandula extract was effective in killing of EF.  Further studies are necessary to fully understand its other properties such as tissue solubility, removal of smear layer and impact on dentin structure.

  2. Photo Catalytic Removal of Sodium Dodecyl Sulfate From Aquatic Solutions With Prepared ZnO Nanocrystals and UV Irradiation

    Directory of Open Access Journals (Sweden)

    Mohammad Taghi Samadi

    2014-12-01

    Full Text Available In this study, ZnO Nano catalyst has been synthesized and examined as photo catalyst for UV-induced removal of Sodium Dodecyl Sulfate (SDS from aquatic solutions. This anionic surfactant was selected based upon its toxicity, wide use in industrial laundry and as a primary pollutant in municipal waste water systems.This study aimed to investigate removal of surfactant, SDS, in a batch photo catalytic reactor under various operating conditions including ZnO suspension concentration, initial surfactant concentration and initial pH of solution to find out the desired condition for removal of surfactant. ZnO Nano crystals were synthesized using the precipitation method and ZnSO4.7H2O was used as the starting material and NaOH as precipitant. The removal of SDS reactions by UV/ZnO process was performed into a batch photo reactor. In addition, various operating conditions including ZnO suspension concentration, initial surfactant concentration and initial pH of solution were investigated. In total, 98% of surfactant was removed at 40 minute and removal efficiency of SDS increased with increasing pH up to nine and after that with increase in pH, efficiency decreased. Possible roles of inorganic oxidant on the reaction were discussed. The removal of SDS follows pseudo-first order kinetics. Based on the results of this study, ZnO-UV photo catalytic process can be used as an efficient method for further study in detergents removal.

  3. Transurethral enucleation of large benign prostatic hyperplasia in sodium chloride solution

    Directory of Open Access Journals (Sweden)

    I. N. Shvarev

    2016-01-01

    Full Text Available Background. Transurethral resection is a generally recognized treatment for small to medium-sized benign prostatic hyperplasia (BPH. Numerous original tools are proposed for surgery of large BPH. These include laser (holmium laser enucleation of the prostate and transurethral (transurethral enucleation with bipolar (TUEB enucleation in 0.9 % NaCl solution, which are accompanied by removal of the maximum adenoma tissue volume, short-term recovery, and a substantially fewer early and late complications.Objective: to evaluate the safety and efficiency of TUEB in patients with large BPH.Subjects and methods. TUEB was carried out in 58 patients with large BPH. Their mean age was 64 years. The gland size was ≥ 102 сm3. The residual urine volume in all the patients was more than 100 ml. One year later, the results of treatment were analyzed using the International Prostate Symptom Score (IPSS, Quality of Life (QoL Questionnaire, as well as from residual urine volume and remaining prostate tissue.Results. The mean time of surgery and enucleation was 90 and 55 min, respectively. The mean volume of removed adenoma tissue was 99 ml. By the end of month 2 following TUEB, there was a progressive reduction in the total IPSS and QoL scores from 35 to 7 and from 5 to 1, respectively, which preserved this trend by the end of a 1-year follow-up. study. The residual urine amount was less than 30 ml. The mean volume of the prostate tissue left was 8.5 сm3 and less than 11.0 сm3. The ultrasound anatomy of the prostatic urethra (transformation of thin-walled spherical TUR defect that is characteristic slit-like one resembles the inverted letter Y eventually formed by the end of the 1-year follow-up. Stricture of the urethra and contracture of the bladder neck were noted in none of the cases. Conclusion. TUEB is an alternative to open surgery in patients with the enlarged prostate. The use of isotonic NaCl solution as washing fluid allows one to plan

  4. Real surface area of the aluminium electrode in sodium chloride solution

    Directory of Open Access Journals (Sweden)

    Z. RAKOCEVIC

    1999-11-01

    Full Text Available By combining the techniques of electrochemical slow potentiodynamic, AC impedance and atomic force microscopy (AFM, it was shown that the differences in the anodic dissolution rates of Al in 0.5 NaCl solutions as measured experimentally in the potential region between the corrosion and pitting potential, are mainly due to differences in surface roughness of the electrodes used. It was shown that mechanical grinding and polishing of the electrode surface with emery paper (400 grit and alumina polishing powder (f 0.25 mm can produce surfaces differing by a factor of 6 in the roughness factor Ra. By using AFM estimates of the roughness factors a true electrode capacitance of 4.63 µC cm-2 and thickness dox ~ 2.0 nm for the barrier layer of the surface film was estamited. The outer part of the film is porous, partly as amorphous Al(OH3, or crystalline bayerite (Al2O3.3H2O.

  5. The anodic dissolution of SIMFUEL (UO2) in slightly alkaline sodium carbonate/bicarbonate solutions

    International Nuclear Information System (INIS)

    Keech, P.G.; Goldik, J.S.; Qin, Z.; Shoesmith, D.W.

    2011-01-01

    The corrosion of nuclear fuel under waste disposal conditions is likely to be influenced by the bicarbonate/carbonate content of the groundwater since it increases the solubility of the U VI corrosion product, [UO 2 ] 2+ . As one of the half reactions involved in the corrosion process, the anodic dissolution of SIMFUEL (UO 2 ) has been studied in bicarbonate/carbonate solutions (pH 9.8) using voltammetric and potentiostatic techniques and electrochemical impedance spectroscopy. The reaction proceeds by two consecutive one electron transfer reactions (U IV → U V → U VI ). At low potentials (≤250 mV (vs. SCE) the rate of the first electron transfer reaction is rate determining irrespective of the total carbonate concentration. At potentials >250 mV (vs. SCE) the formation of a U VI O 2 CO 3 surface layer begins to inhibit the dissolution rate and the current becomes independent of potential indicating rate control by the chemical dissolution of this layer.

  6. Diffusion-controlled evaporation of sodium dodecyl sulfate solution drops placed on a hydrophobic substrate.

    Science.gov (United States)

    Doganci, Merve Dandan; Sesli, Belma Uyar; Erbil, H Yildirim

    2011-10-15

    In this work, the effect of SDS anionic surfactant on the diffusion-controlled evaporation rate of aqueous solution drops placed on TEFLON-FEP substrate was investigated with 11 different SDS concentrations. Drop evaporation was monitored in a closed chamber having a constant RH of 54-57% by a video camera. The initial contact angle, θ(i) decreased from 104±2° down to 68±1° due to the adsorption of SDS both at the water-air and the solid-water interfaces. The adsorption of SDS on the solid surface was found to be 76% of that of its adsorption at the water-air interface by applying Lucassen-Reynders approach. An equation was developed for the comparison of the evaporation rates of drops having different θ(i) on the same substrate. It was found that the addition of SDS did not alter the drop evaporation rate considerably for the first 1200 s for all the SDS concentrations. The main difference was found to be the change of the mode of drop evaporation by varying the SDS concentration. The constant θ mode was operative up to 80 mM SDS concentration, whereas constant contact area mode was operative after 200 mM SDS concentrations due to rapid drop pining on the substrate. Copyright © 2011 Elsevier Inc. All rights reserved.

  7. Iron Nanoparticles (Fe3O4 Used to Synthesize Magnetic Sodium Alginate Hydrogel Beads for the Removal of Basic Blue 159 from Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    Atiyeh Ghajarieh

    2017-11-01

    Full Text Available Dyes are a main source of pollutants in textile plant effluents. Due to their molecular structure, they are usually toxic, carcinogenous, and persistent in the environment. The aim of the present work was to explore the removal of basic blue159 (BB159 using magnetic sodium alginate hydrogel beads. Magnetic sodium alginate hydrogel beads were initially synthesized  accoriodng to Rocher method using CaCl2 as a crosslink agent. Fourier transform infrared spectroscopy (FTIR was then employed to examine the functional groups on the surface of the magnetic sodium alginate hydrogel beads. In a third stage, the magnetic properties of the beads were measured using a vibrating sample magnetometer (VSM and the magnetic parameters were calculated. Subsequently, the effects of such parameters as adsorbent dosage, pH, initial concentration of dye, and contact time were evaluated on the BB159 removal efficiency of the adsorbent used. Finally, the Langmuir, Freundlich, Temkin, and B.E.T models were exploited to study the adsorption isotherm of BB159 onto the magnetic sodium alginate hydrogel beads. It was found that the magnetic sodium alginate beads possess both –COO and –OH groups that play important roles in the adsorption of the positively charged BB159 dye. A saturation magnetization equal to 21/8(emu/g was obtained for the sodium alginate beads/nano Fe3O4. Results also revealed that the highest dye removal from aqueous solutions was achieved at pH=11 in 120 minutes for 9 grams of the adsorbent. The study indicated that BB159 removal using the magnetic sodium alginate hydrogel beads as the adsorbent obeys the Langmuir model. Moreover, it was shown that the efficiency of the process for BB159 removal from aqueous solutions was satisfactory (85%.

  8. Contribution to the study of wastes stabilization by sulfo-aluminate cement

    International Nuclear Information System (INIS)

    Peysson, S.

    2005-02-01

    Calcium sulfo-aluminate cement is mainly composed of yeelimite known to be a precursor of ettringite formation. Ettringite is able to incorporate several heavy metals by isomorphous substitutions without altering its crystalline structure. The design of a binder required for immobilizing heavy metals was undertaken. The hydration study of clinker, and cement containing 4 amounts of gypsum has been carried out by means of XRD, DTA and IR spectrometry. It was pointed out that the addition of gypsum enhances hydration. Two binders were selected: 80/20 and 70/30. The immobilisation of 7 pollutants was very successful. Nevertheless, damages appeared with the binder 70/30 containing sodium chromate and dichromate: sodium caused activation of yeelimite reactivity and important dissolution of gypsum leading to important ettringite production. With a great amount of gypsum (30 %), dissolution led to secondary ettringite formation which damaged the hardened paste. Adding polyol enhances the retention of sodium chromate. On the other hand, the immobilisation of two types of weakly radioactive wastes supplied by CEA has been made. Results obtained in terms of setting time, compressive strength and leaching were excellent. (author)

  9. Tailoring the particulate properties of aluminates prepared by ...

    Indian Academy of Sciences (India)

    Administrator

    Tailoring the particulate properties of aluminates prepared by combustion method. T MIMANI and K C PATIL. Department of Inorganic and Physical Chemistry, Indian Institute of Science,. Bangalore 560 012, India. Aluminium based spinels constitute an interesting class of oxide ceramics with technological applications such ...

  10. Function of magnesium aluminate hydrate and magnesium nitrate ...

    Indian Academy of Sciences (India)

    MgO was added both as spinel (MgAl2O4) forming precursor i.e. magnesium aluminate hydrate, and magnesium nitrate. Sintering investigations were conducted in the temperature range 1500–1600°C with 2 h soaking. Structural study of sintered pellets was carried out by extensive XRD analysis. Scanning electron mode ...

  11. On structural, optical and dielectric properties of zinc aluminate ...

    Indian Academy of Sciences (India)

    with a normal spinel structure having all zinc cations in the tetrahedral and all aluminium cations in the octahedral ... rrite in the nano-regime show anomalous magnetic properties in that zinc ions instead of occupying ... (Roy et al 2006). Zinc aluminate can be con- sidered as the non-magnetic counterpart of zinc ferrite and.

  12. Tailoring the particulate properties of aluminates prepared by ...

    Indian Academy of Sciences (India)

    Administrator

    Aluminium based spinels constitute an interesting class of oxide ceramics with technological applications such as abrasives, pigments, catalysts, phosphors etc. The nano-structured ceramics display improved properties over the bulk materials 1. Nano- crystalline aluminate spinels MAl2O4, M = Zn and Mn, have been ...

  13. Investigation of tritium release and retention in lithium aluminate

    International Nuclear Information System (INIS)

    Kopasz, J.P.; Tistchenko, S.; Botter, F.

    1991-01-01

    Tritium release from lithium aluminate, although previously investigated by both in-reactor and ex-reactor experiments, remains poorly understood. Agreement between experiments is lacking, and the mechanisms responsible for tritium release from lithium aluminate are under debate. In an effort to improve our understanding of the mechanisms of tritium release from lithium ceramics, we have investigated tritium release from pure lithium aluminate and lithium aluminate doped with impurities. The results of these experiments on large grain size material indicate that after anneals at low temperature, a large fraction of the tritium present before the anneal remains in the sample. We have modeled this behavior based on first-order release from three types of sites. At the lowest temperature, the release is dominated by one site, while the tritium in the other sites is retained in the solid. Adding magnesium dopant to the ceramic appears to alter the distribution of tritium between the sites. This addition decreases the fraction of tritium released at 777 degree C, while increasing the fractions released at 538 and 950 degree C. 11 refs., 8 figs., 1 tab

  14. On structural, optical and dielectric properties of zinc aluminate ...

    Indian Academy of Sciences (India)

    Abstract. Zinc aluminate nanoparticles with average particle size of 40 nm were synthesized using a sol–gel com- bustion method. X-ray diffractometry result was analysed by Rietveld refinement method to establish the phase purity of the material. Different stages of phase formation of the material during the synthesis were ...

  15. Study of corrosion processes on Al-AA 6061 crevices immersed in high purity water and sodium citrate solution

    International Nuclear Information System (INIS)

    Rodriguez, Sebastian A.; Haddad, Roberto; Lanzani, Liliana A.

    2004-01-01

    An experimental approach has been developed to study the corrosion behavior of artificial crevices manufactured with high purity aluminum and AA 6061 alloy, immersed in dematerialised water and sodium citrate solution (96,5 μS/cm). Alkaline attack was found on the surrounding of iron rich particles in the external zone of the crevice, as a result of localized oxygen reduction reaction on these sites. This attack was not observed in the zone inside the crevice. Study of the phase Mg 2 Si by EDS allowed establishing that there is not preferential dissolution inside the crevice. The formation of a stable and non-soluble complex between Al and citrate anion inhibited the production of Al(OH) 3 precipitate, which was observed on the surface of specimens immersed in pure water. Investigations of the aluminum oxide evolution on AA 6061 surfaces in water showed that it was composed by two layers: an internal one made of Bohemite and an external one in direct contact with the water, with a Bayerite structure. The surface analysis was accomplished using XR, OM and SEM techniques. (author) [es

  16. The Synergistic Effect of Iodide and Sodium Nitrite on the Corrosion Inhibition of Mild Steel in Bicarbonate–Chloride Solution

    Directory of Open Access Journals (Sweden)

    Gaius Debi Eyu

    2016-10-01

    Full Text Available The effect of potassium iodide (KI and sodium nitrite (NaNO2 inhibitor on the corrosion inhibition of mild steel in chloride bicarbonate solution has been studied using electrochemical techniques. Potentiodynamic polarisation data suggest that, when used in combination, KI and NaNO2 function together to inhibit reactions at both the anode and the cathode, but predominantly anodic. KI/NO2− concentration ratios varied from 2:1 to 2:5; inhibition efficiency was optimized for a ratio of 1:1. The surface morphology and corrosion products were analysed using scanning electron microscopy (SEM and X-ray diffractometry (XRD. The latter shows that the addition of I− to NO2 facilitates the formation of a passivating oxide (γ-Fe2O3 as compared to NO2− alone, decreasing the rate of metal dissolution observed in electrochemical testing. The synergistic effect of KI/NO2− inhibition was enhanced under the dynamic conditions associated with testing in a rotating disc electrode.

  17. Fast solution combustion synthesis of porous NaFeTi3O8 with superior sodium storage properties

    Science.gov (United States)

    Zhao, Jin-Bao; Li, Xue; Xiao, Qian

    2018-01-01

    In this work, NaFeTi3O8 with three-dimensional porous net-like sheet morphology is firstly prepared by a simple and effective solution combustion method. Encouragingly, when being assessed as an anode electrode for sodium ion batteries, the NaFeTi3O8 net-like sheet composite exhibits superior electrochemical properties. We also study the effect of the combustion fuel glycine. The results indicate that the NaFeTi3O8 composite tends to be porous with glycine as the combustion fuel, which displays more excellent long cyclic stability (discharge capacity of 91 mA h g-1 after 1000 cycles at the current density of 0.5 A g-1) and superior rate performance (84.4 mA h g-1 even at 1.6 A g-1) than that of NaFeTi3O8 without glycine as the combustion agent. The enhanced electrochemical properties could be ascribed to the unique porous morphology, which achieves better electrolyte infiltration and faster ion diffusion. [Figure not available: see fulltext.

  18. Novel Swelling-Resistant Sodium Alginate Membrane Branching Modified by Glycogen for Highly Aqueous Ethanol Solution Pervaporation.

    Science.gov (United States)

    Ji, Chen-Hao; Xue, Shuang-Mei; Xu, Zhen-Liang

    2016-10-12

    A novel carbohydrate chain cross-linking method of sodium alginate (SA) is proposed in which glycogen with the branched-chain structure is utilized to cross-link with SA matrix by the bridging of glutaraldehyde (GA). The active layer of SA composite ceramic membrane modified by glycogen and GA for pervaporation (PV) demonstrates great advantages. The branched structure increases the chain density of the active layer, which compresses the free volume between the carbohydrate chains of SA. Large amounts of hydroxyl groups are consumed during the reaction with GA, which reduces the hydrogen bond formation between water molecules and the polysaccharide matrix. The two factors benefit the active layer with great improvement in swelling resistance, promoting the potential of the active layer for the dehydration of an ethanol-water solution containing high water content. Meanwhile, the modified active layer is loaded on the rigid α-Al 2 O 3 ceramic membrane by dip-coating method with the enhancement of anti-deformation and controllable thickness of the active layer. Characterization techniques such as SEM, AFM, XRD, FTIR, XPS, and water contact angle are utilized to observe the composite structure and surface morphology of the composite membrane, to probe the free volume variation, and to determine the chemical composition and hydrophilicity difference of the active layer caused by the different glycogen additive amounts. The membrane containing 3% glycogen in the selective layer demonstrates the flux at 1250 g m -2 h -1 coupled with the separation factor of 187 in the 25 wt % water content feed solution at the operating temperature of 75 °C, reflecting superior pervaporation processing capacity compared with the general organic PV membranes in the same condition.

  19. Removal of Fluoride Ion from Aqueous Solution by Nanocomposite Hydrogel Based on Starch/Sodium Acrylate/Nano Aluminum Oxide

    Directory of Open Access Journals (Sweden)

    Aboulfazl Barati

    2014-01-01

    Full Text Available Determination of fluoride in drinking water has received increasing interest, due to its beneficial and detrimental effects on health. Contamination of drinking water by fluoride can cause potential hazards to human health. In recent years, considerable attention has been given to different methods for the removal of fluoride from drinking and waste waters. The aim of this research was to investigate the effect of nano composite hydrogel based on starch/sodium acrylate/aluminum oxide in reduction of fluoride concentration in drinking water and industrial waste water. In a batch system, the dynamic and equilibrium adsorption of fluoride ions were studied with respect to changes in determining parameters such as pH, contact time, initial fluoride concentration, starch/acrylic acid weight ratio and weight percent of nano aluminum oxide. The obtained equilibrium adsorption data were fitted with Langmuir and Freundlich models, as well as the kinetic data with pseudo-first order and pseudo- second order models. The results showed that optimum pH was found to be in the range of 5 to 7. Removal efficiency of fluoride was increased with decreases in initial concentration of fluoride. Sixty percent of initial value of fluoride solution was removed by nano composite hydrogel (4 wt% of nano aluminum oxide at 240 min (initial fluoride concentration = 5 ppm, pH 6.8 and temperature = 25ºC. Under the same condition, the equilibrium adsorption of fluoride ions was 85% and 68% for initial solution concentration of 5 and 10 ppm, respectively. Adsorption isotherm data showed that the fluoride sorption followed the Langmuir model. Kinetics of sorption of fluoride onto nano composite hydrogel was described by pseudo-first order model.

  20. In Vitro Inhibition of Cytopathic Effect of Influenza Virus and Human Immunodeficiency Virus by Bamboo Leaf Extract Solution and Sodium Copper Chlorophyllin.

    Science.gov (United States)

    Ito, Akiko; Tsuneki, Akeno; Yoshida, Yu; Ryoke, Kazuo; Kaidoh, Toshiyuki; Kageyama, Seiji

    2016-03-01

    Although the link between oral and oropharyngeal health status and susceptibility to infection has long been recognized, there is a limit to the selection of antiseptics for oral care. Madin-Darby canine kidney (MDCK) cells were exposed to influenza virus and cultured in the presence or absence of test reagents: bamboo leaf extract solution and sodium copper chrolophyllin. MDCK cells were pre-incubated with the reagents to assess the inhibitory activity at adsorption (viral attachment). Similarly, anti-HIV activity and the inhibitory mechanism at adsorption were assessed by MT-2 cell culture system. Mixture of HIV and bamboo leaf extract solution was fixed and examined by transmission electron microscopy. The 50% inhibitory concentration (IC50) of bamboo leaf extract solution against influenza virus and the 50% cytotoxic concentration (CC50) in MDCK cells of the solution lay between 0.0313-0.0625% and 0.5-1.0%. The solution inhibited the influenza virus adsorption at the concentration of 0.5% (P copper chlorophyllin lay between 50-100 µM and 200-400 µM, respectively. This inhibited the virus adsorption at 200 µM (P extract solution showed values of IC50 against HIV and CC50 in MT-2 cells at around 0.0313% and between 0.25-0.5%, respectively. This solution inhibited HIV adsorption at 1.25% (P copper chlorophyllin lay between 50-100 µM and 200-400 µM, respectively. Sodium copper chlorophyllin inhibited HIV adsorption at 2.5 mM (P extract solution. Sodium copper chlorophyllin exerted antiviral activities against influenza virus and HIV as the major ingredient of bamboo leaf extract solution by blocking adsorption. This mechanism of action is different completely from the one of povidone-iodine.

  1. Electrochemical studies of sodium meta-vanadate as corrosion inhibitor of carbon steel 1020 in CO{sub 2} and H{sub 2}S saturated DEA solutions

    Energy Technology Data Exchange (ETDEWEB)

    Aghasadeghi, Alireza [Corrosion Department of Research Institute of Petroleum Industry, P.O.Box 18745-4163, NIOC Pazhouheshgah Blvd., Khairabad, Qom Road, Tehran (Iran)

    2004-07-01

    Several types of corrosion inhibitors are recently used in amine systems for natural gas refining in the world because of the corrosive nature of amine solutions containing acid gases. This article introduces corrosion inhibitor basis that are used mostly as active reagents in corrosion inhibitor packages. Accordingly, sodium meta-vanadate is studied as corrosion inhibitor of carbon steel 1020 in 30-vol% DEA and industrial lean and rich amines solutions saturated with CO{sub 2} and H{sub 2}S at 65 deg. C. Electrochemical Tafel polarization test method was conducted to investigate the inhibitive behavior of sodium meta-vanadate in the mentioned solutions that are near industrial conditions. Tafel slopes and corrosion potentials show that the inhibitive mechanism of sodium meta-vanadate is anodic and effective dosage of the inhibitor is within 0.03 to 0.05 wt% in 30-vol% DEA, industrial lean and rich amines solutions saturated with CO{sub 2} and H{sub 2}S at 65 deg. C. Surface observations indicate that the corrosion on the carbon steel coupons was general and using this optimum concentration with an inhibitive performance of at least 80% did not occur localized or pitting corrosion. (author)

  2. Preparation of Carbon-Chitosan-Polyvinyl Chloride (CC-PVC) Material and its Application to Electrochemical Degradation of Methylene Blue in Sodium Chloride Solution

    Science.gov (United States)

    Riyanto; Prawidha, A. D.

    2018-01-01

    Electrochemical degradation of methylene blue using Carbon-Chitosan-Polyvinyl Chloride (CC-PVC) electrode in sodium chloride have been done. The aim of this work was to degradation of methylene blue using Carbon-Chitosan-Polyvinyl Chloride (CC-PVC). Carbon chitosan composite electrode was preparing by Carbon and Chitosan powder and PVC in 4 mL tetrahydrofuran (THF) solvent and swirled flatly to homogeneous followed by drying in an oven at 100 °C for 3 h. The mixture was placed in stainless steel mould and pressed at 10 ton/cm2. Sodium chloride was used electrolyte solution. The effects of the current and electrolysis time were investigated using spectrophotometer UV-Visible. The experimental results showed that the carbon-chitosan composite electrode have higher effect in the electrochemical degradation of methylene blue in sodium chloride. Based on UV-visible spectra analysis shows current and electrolysis time has high effect to degradation of methylene blue in sodium chloride. Chitosan and polyvinyl chloride can strengthen the bond between the carbons so that the material has the high stability and conductivity. As conclusions is Carbon-Chitosan-Polyvinyl Chloride (CC-PVC) electrode have a high electrochemical activity for degradation of methylene blue in sodium chloride.

  3. The Effect of Bamboo Leaf Extract Solution and Sodium Copper Chlorophyllin Solution on Growth and Volatile Sulfur Compounds Production of Oral Malodor Associated Some Anaerobic Periodontal Bacteria.

    Science.gov (United States)

    Majbauddin, Abir; Kodani, Isamu; Ryoke, Kazuo

    2015-09-01

    Bamboo leaf extract solution (BLES) and sodium copper chlorophyllin solution (SCCS) are known for their anti-oxidant activities. Oral malodor is often related with periodontal pathogens. The present study was undertaken to investigate the anti-bacterial effect of both BLES and SCCS on anaerobic periodontal bacteria producing oral malodorous volatile sulfur compounds (VSC). Porphyromonas gingivalis W83 (PG), Prevotella intermidai TDC19B (PI), Fusobacterium nucleatum ATCC25586 (FN) and Prevotella nigrescence ATCC33563 (PN) were investigated as oral isolated bacteria. VSC production ability of the oral strains was investigated by gas chromatography. With serial dilution of BLES or SCCS, the strains PG, PI, FN or PN were cultured anaerobically with AnaeroPack at 37 ℃ for 3 days. For the determination of anti-bacterial action of BLES or SCCS, the inoculum was cultured with original concentrations of BLES 0.16% (w/v) or SCCS 0.25% (w/v). Gas chromatography exhibited that all strains, PG, PI, FN and PN were responsible for producing a high range of H2S and a moderate range of CH3SH. Anti-bacterial effect of BLES or SCCS on the strains was observed. Inhibition of BLES or SCCS on the strains was revealed as concentration dependent. BLES or SCCS inhibited bacterial proliferation at higher concentrations (PG; 0.04% BLES or 0.03% SCCS, PI; 0.002% BLES or 0.03% SCCS, FN; 0.005% BLES or 0.01% SCCS, PN; 0.01% BLES or 0.015% SCCS). No viable bacterial colony observed at original concentration of BLES 0.16% or SCCS 0.25%. Strain growth was eliminated from inhibition at lower concentrations (PG; 0.02% BLES or 0.015% SCCS, PI; 0.001% BLES or 0.015% SCCS, FN; 0.002% BLES or 0.007% SCCS, PN; 0.005% BLES or 0.007% SCCS). High concentrations of both BLES (0.16%) and SCCS (0.25%) show superior inhibiting capability on all four oral malodor associated periodontal anaerobes during testing, suggesting that these compounds might have a beneficial effect on oral health care.

  4. Standard test method for evaluating stress-corrosion cracking of stainless alloys with different nickel content in boiling acidified sodium chloride solution

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2000-01-01

    1.1 This test method describes a procedure for conducting stress-corrosion cracking tests in an acidified boiling sodium chloride solution. This test method is performed in 25% (by mass ) sodium chloride acidified to pH 1.5 with phosphoric acid. This test method is concerned primarily with the test solution and glassware, although a specific style of U-bend test specimen is suggested. 1.2 This test method is designed to provide better correlation with chemical process industry experience for stainless steels than the more severe boiling magnesium chloride test of Practice G36. Some stainless steels which have provided satisfactory service in many environments readily crack in Practice G36, but have not cracked during interlaboratory testing using this sodium chloride test method. 1.3 This boiling sodium chloride test method was used in an interlaboratory test program to evaluate wrought stainless steels, including duplex (ferrite-austenite) stainless and an alloy with up to about 33% nickel. It may also b...

  5. Regenerable granular carbon nanotubes/alumina hybrid adsorbents for diclofenac sodium and carbamazepine removal from aqueous solution.

    Science.gov (United States)

    Wei, Haoran; Deng, Shubo; Huang, Qian; Nie, Yao; Wang, Bin; Huang, Jun; Yu, Gang

    2013-08-01

    A novel granular carbon nanotubes (CNTs)/alumina (Al2O3) hybrid adsorbent with good sorption and regeneration properties was successfully prepared by mixing CNTs with surfactant Brij 35 and pseudo boehmite, followed by calcining to remove surfactant and form porous granules. Alumina binder increased the mechanical strength, hydrophilicity and porosity of the granular adsorbent, while the dispersed CNTs in the granular adsorbent were responsible for the sorption of diclofenac sodium (DS) and carbamazepine (CBZ). Scanning electron microscopy (SEM) showed that the CNTs and Al2O3 were mixed well and the porous structure was formed in the granular adsorbent. The high surface area and appropriate pore size of granular CNTs/Al2O3 adsorbent were favorable for sorption. The sorption of DS decreased with increasing solution pH, while pH had little effect on CBZ sorption. The maximum sorption capacities of CBZ and DS on the CNTs/Al2O3 adsorbent were 157.4 and 106.5 μmol/g according to the Langmuir fitting. Moreover, the spent CNTs/Al2O3 adsorbent can be thermally regenerated at 400 °C in air due to the thermal stability of CNTs. The removal of CBZ and DS changed a little in the initial reuse cycles and then kept relatively constant until tenth cycles. The adsorbed CBZ and DS were decomposed in the regeneration process. This regenerable adsorbent may find potential application in water or wastewater treatment for the removal of some micropollutants such as pharmaceuticals. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Multistate outbreak of Serratia marcescens bloodstream infections caused by contamination of prefilled heparin and isotonic sodium chloride solution syringes.

    Science.gov (United States)

    Blossom, David; Noble-Wang, Judith; Su, John; Pur, Stacy; Chemaly, Roy; Shams, Alicia; Jensen, Bette; Pascoe, Neil; Gullion, Jessica; Casey, Eric; Hayden, Mary; Arduino, Matthew; Budnitz, Daniel S; Raad, Isaam; Trenholme, Gordon; Srinivasan, Arjun

    2009-10-12

    To investigate clusters of Serratia marcescens (SM) bloodstream infections (BSIs) at health care facilities in several states and determine whether contaminated prefilled heparin and isotonic sodium chloride solution (hereinafter, saline) syringes from a single manufacturer (company X) were the likely cause, we performed an outbreak investigation of inpatient and outpatient health care facilities from October 2007 through February 2008. Active case finding for clusters of SM BSIs. Information on SM BSIs was obtained, and SM blood isolates were sent to the Centers for Disease Control and Prevention (CDC). Culture specimens were taken from various lots of prefilled heparin and saline syringes by health care facilities and the CDC to test for the presence of SM. The SM isolates from syringes and blood were compared by pulsed-field gel electrophoresis. A total of 162 SM BSIs in 9 states were reported among patients at facilities using prefilled heparin and/or saline syringes made by company X. Cultures of unopened prefilled heparin and saline syringes manufactured by company X grew SM. Of 83 SM blood isolates submitted to the CDC from 7 states, 70 (84%) were genetically related to the SM strain isolated from prefilled syringes. A US Food and Drug Administration inspection revealed that company X was not in compliance with quality system regulations. A multistate outbreak of SM BSIs was associated with intrinsic contamination of prefilled syringes. Our investigation highlights important issues in medication safety, including (1) the importance of pursuing possible product-associated outbreaks suggested by strong epidemiologic data even when initial cultures of the suspected product show no contamination and (2) the challenges of medical product recalls when production has been outsourced from one company to another.

  7. The Effect of Fe-enrich Phase on the Pitting Corrosion Resistance of Al Alloy in Various Neutral Sodium Chloride Solutions

    OpenAIRE

    Priyotomo, Gadang; Gede Putrayasa Astawa, I Nyoman

    2014-01-01

    The pitting corrosion of 5052 alloy was investigated as function of chloride concentrations by using an electrochemical method, scanning electron microscope and energy dispersive X-Ray spectroscopy in neutral sodium chloride solutions at 293 K.  The pitting corrosion of pure Al was also investigated under the same experimental condition for the comparison. The pitting potential obtained for 5052 alloy and pure Al decreased with increasing chloride concentration.  The pitting potential of pure...

  8. A comparative evaluation of antibacterial effectiveness of sodium hypochlorite, Curcuma longa, and Camellia sinensis as irrigating solutions on isolated anaerobic bacteria from infected primary teeth

    OpenAIRE

    Neha Shashikant Dhariwal; Shivayogi M Hugar; Sheetal Harakuni; Suma Sogi; Harsha G Assudani; Laresh Naresh Mistry

    2016-01-01

    Context: In endodontics, most of the commercial intra-canal medicaments have cytotoxic reactions and because of their inability to eliminate bacteria from dentinal tubules, recent medicine has turned its attention to the usage of biologic medication prepared from natural plants. The literature to testify the efficacy of natural alternatives in primary teeth is meagre and its effects as irrigating solutions need to be evaluated. Aim: To evaluate the antibacterial effectiveness of sodium hypoch...

  9. Hydration water and microstructure in calcium silicate and aluminate hydrates

    International Nuclear Information System (INIS)

    Fratini, Emiliano; Ridi, Francesca; Chen, Sow-Hsin; Baglioni, Piero

    2006-01-01

    Understanding the state of the hydration water and the microstructure development in a cement paste is likely to be the key for the improvement of its ultimate strength and durability. In order to distinguish and characterize the reacted and unreacted water, the single-particle dynamics of water molecules in hydrated calcium silicates (C 3 S, C 2 S) and aluminates (C 3 A, C 4 AF) were studied by quasi-elastic neutron scattering, QENS. The time evolution of the immobile fraction represents the hydration kinetics and the mobile fraction follows a non-Debye relaxation. Less sophisticated, but more accessible and cheaper techniques, like differential scanning calorimetry, DSC, and near-infrared spectroscopy, NIR, were validated through QENS results and they allow one to easily and quantitatively follow the cement hydration kinetics and can be widely applied on a laboratory scale to understand the effect of additives (i.e., superplasticizers, cellulosic derivatives, etc) on the thermodynamics of the hydration process. DSC provides information on the free water index and on the activation energy involved in the hydration process while the NIR band at 7000 cm -1 monitors, at a molecular level, the increase of the surface-interacting water. We report as an example the effect of two classes of additives widely used in the cement industry: superplasticizers, SPs, and cellulose derivatives. SPs interact at the solid surface, leading to a consistent increment of the activation energy for the processes of nucleation and growth of the hydrated phases. In contrast, the cellulosic additives do not affect the nucleation and growth activation energy, but cause a significant increment in the water availability: in other words the hydration process is more efficient without any modification of the solid/liquid interaction, as also evidenced by the 1 H-NMR. Additional information is obtained by scanning electron microscopy (SEM), ultra small angle neutron scattering (USANS) and wide

  10. Hydration water and microstructure in calcium silicate and aluminate hydrates

    Energy Technology Data Exchange (ETDEWEB)

    Fratini, Emiliano [Department of Chemistry and CSGI, University of Florence, via della Lastruccia 3-Sesto Fiorentino, I-50019 Florence (Italy); Ridi, Francesca [Department of Chemistry and CSGI, University of Florence, via della Lastruccia 3-Sesto Fiorentino, I-50019 Florence (Italy); Chen, Sow-Hsin [Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Baglioni, Piero [Department of Chemistry and CSGI, University of Florence, via della Lastruccia 3-Sesto Fiorentino, I-50019 Florence (Italy)

    2006-09-13

    Understanding the state of the hydration water and the microstructure development in a cement paste is likely to be the key for the improvement of its ultimate strength and durability. In order to distinguish and characterize the reacted and unreacted water, the single-particle dynamics of water molecules in hydrated calcium silicates (C{sub 3}S, C{sub 2}S) and aluminates (C{sub 3}A, C{sub 4}AF) were studied by quasi-elastic neutron scattering, QENS. The time evolution of the immobile fraction represents the hydration kinetics and the mobile fraction follows a non-Debye relaxation. Less sophisticated, but more accessible and cheaper techniques, like differential scanning calorimetry, DSC, and near-infrared spectroscopy, NIR, were validated through QENS results and they allow one to easily and quantitatively follow the cement hydration kinetics and can be widely applied on a laboratory scale to understand the effect of additives (i.e., superplasticizers, cellulosic derivatives, etc) on the thermodynamics of the hydration process. DSC provides information on the free water index and on the activation energy involved in the hydration process while the NIR band at 7000 cm{sup -1} monitors, at a molecular level, the increase of the surface-interacting water. We report as an example the effect of two classes of additives widely used in the cement industry: superplasticizers, SPs, and cellulose derivatives. SPs interact at the solid surface, leading to a consistent increment of the activation energy for the processes of nucleation and growth of the hydrated phases. In contrast, the cellulosic additives do not affect the nucleation and growth activation energy, but cause a significant increment in the water availability: in other words the hydration process is more efficient without any modification of the solid/liquid interaction, as also evidenced by the {sup 1}H-NMR. Additional information is obtained by scanning electron microscopy (SEM), ultra small angle neutron

  11. Recovery of uranium from the Syrian phosphate by solid-liquid method using alkaline solutions

    International Nuclear Information System (INIS)

    Shlewit, H.; Alibrahim, M.

    2007-01-01

    Uranium concentrations were analyzed in the Syrian phosphate deposits. Mean concentrations were found between 50 and 110 ppm. As a consequence, an average phosphate dressing of 22 kg/ha phosphate would charge the soil with 5-20 g/ha uranium when added as a mineral fertilizer. Fine grinding phosphate produced at the Syrian mines was used for uranium recovery by carbonate leaching. The formation of the soluble uranyl tricarbonate anion UO 2 (CO 3 ) 3 4- permits use of alkali solutions of sodium carbonate and sodium bicarbonate salts for the nearly selective dissolution of uranium from phosphate. Separation of iron, aluminum, titanium, etc., from the uranium during leaching was carried out. Formation of some small amounts of molybdates, vanadates, phosphates, aluminates, and some complexes metal was investigated. This process could be used before the manufacture of TSP fertilizer, and the final products would contain smaller uranium quantities. (author)

  12. Determination of performance of non-ideal aluminized explosives.

    Science.gov (United States)

    Keshavarz, Mohammad Hossein; Mofrad, Reza Teimuri; Poor, Karim Esmail; Shokrollahi, Arash; Zali, Abbas; Yousefi, Mohammad Hassan

    2006-09-01

    Non-ideal explosives can have Chapman-Jouguet (C-J) detonation pressure significantly different from those expected from existing thermodynamic computer codes, which usually allows finding the parameters of ideal detonation of individual high explosives with good accuracy. A simple method is introduced by which detonation pressure of non-ideal aluminized explosives with general formula C(a)H(b)N(c)O(d)Al(e) can be predicted only from a, b, c, d and e at any loading density without using any assumed detonation products and experimental data. Calculated detonation pressures show good agreement with experimental values with respect to computed results obtained by complicated computer code. It is shown here how loading density and atomic composition can be integrated into an empirical formula for predicting detonation pressure of proposed aluminized explosives.

  13. Phase transformations in lithium aluminates irradiated with neutrons

    International Nuclear Information System (INIS)

    Carrera, L.M.; Delfin L, A.; Urena N, F.; Basurto, R.; Bosch, P.

    2003-01-01

    The lithium aluminate like candidate to be used in the coverings producers of tritium in the fusion nuclear reactors, presents high resistance to the corrosion to the one to be stuck to structural materials as special steels. However, the crystallographic changes that take place in the cover that is continually subjected to irradiation with neutrons, can alter its resistance to the corrosion. In this work the changes of crystalline structure are shown that they present two types of nano structures of lithium aluminates, subjected to an average total dose 7.81 x 10 8 Gy in the fixed irradiation system of capsules of the one TRIGA Mark lll nuclear reactor of the Nuclear Center of Mexico. The studied nano structures presented only phase transformations without formation of amorphous material. (Author)

  14. Age and geochemistry of Alumine's Ignimbrites, Neuquen province, Argentina

    International Nuclear Information System (INIS)

    Lagorio, Silvia; Massaferro, Gabriela

    1998-01-01

    Geochemical and geochronological data from Alumine riolitic welded tuffs are analysed. Minor elements show enrichment in Rb, Th and K and depletion in Nb, Ti, P and Sr. La/Yb ratios are low. The geochemical features are consistent with a volcanic arc genesis. The radiometric data obtained by K/Ar method point out a Paleocene age for these rocks, allowing to correlate them with the Ventana Formation or the equivalent Auca Pan Formation. (author)

  15. Titanium-Aluminum Oxide Coating on Aluminized Steel

    OpenAIRE

    Fuyan Sun; Guang Wang; Xueyuan Nie

    2014-01-01

    In this study, a plasma electrolytic oxidation (PEO) process was used to form titanium-aluminum oxide coating on aluminized steel. The present work was mainly to study the effects of treatment time of PEO process on properties of the titanium coating. A potentiodynamic polarization corrosion test was employed to investigate the corrosion resistance of the coating. The friction coefficient and wear resistance of the coating were studied by using pin-on-disc test. The thermal transfer behaviors...

  16. Tritium extraction from neutron-irradiated lithium aluminate

    International Nuclear Information System (INIS)

    Garcia H, F.

    1995-01-01

    Lithium aluminate is being strongly considered as a breeder material because of its thermophysical, chemical and mechanical stability at high temperatures and its favorable irradiation behavior. Furthermore, it is compatible with other blanket and structural materials. In this work, the effects of calcination temperature during preparation, extraction temperature and sweep gas composition were observed. Lithium aluminate prepared by four different methods, was neutron irradiated for 30 minutes at a flux of 10 12 -10 13 n/cm 2 s in the TRIGA Mark III reactor at Salazar, Mexico; and the tritium extraction rate was measured. Calcination temperature do not affect the tritium extraction rate. However, using high calcination temperature, gamma lithium aluminate was formed. The tritium extraction at 600 Centigrade degrees was lower than at 800 Centigrade degrees and the tritium amount extracted by distillation of the solid sample was higher. The sweep gas composition showed that tritium extraction was less with Ar plus 0.5 % H 2 that with Ar plus 0.1 % H 2 . This result was contrary to expected, where the tritium extraction rate could be higher when hydrogen is added to the sweep gas. Probably this effect could be attributed to the gas purity. (Author)

  17. Dielectric study of aqueous solutions of sodium dodecyl sulfate in the frequency span 20 Hz to 2 MHz

    Science.gov (United States)

    Kadve, A. M.; Vankar, H. P.; Rana, V. A.

    2017-05-01

    Dielectric measurements were carried out for aqueous solutions of Sodium Dodecyl Sulfate (SDS) in the frequency span of 20 Hz to 2 MHz at 300.15 K temperature using precision LCR meter. Also the refractive indices were measured for the solutions at 300.15 K temperature using Abbe's refractometer. The measurements were done for ten different concentrations of SDS in distilled water. Determined values of complex permittivity as a function of frequency were used to evaluate other parameters like loss tangent and electric modulus for the liquid samples. The permittivity at optical frequency were also calculated from the measured refractive indices for the aqueous solutions. The effect of concentration variation of SDS in the aqueous solutions on the determined parameters is discussed.

  18. Efficacy and safety of diclofenac sodium 2% topical solution for osteoarthritis of the knee: a randomized, double-blind, vehicle-controlled, 4 week study.

    Science.gov (United States)

    Wadsworth, L Tyler; Kent, Jeffrey D; Holt, Robert J

    2016-01-01

    Nonsteroidal anti-inflammatory drugs (NSAIDs) are standard therapy for osteoarthritis (OA). Topically applied NSAIDs reduce systemic exposure compared with oral NSAIDS, and European guidelines recommend their use. The NSAID diclofenac is available in a range of topical formulations. Diclofenac 1% gel and 1.5% four times daily and 2% twice daily (BID) solutions are approved to reduce pain from OA of the knee(s). The objective of this study was to investigate the efficacy and safety of diclofenac sodium 2% topical solution BID versus vehicle control solution for treating pain associated with OA of the knee. A phase II, 4 week, randomized, double-blind, parallel-group, two-arm, vehicle-controlled study compared pain relief with diclofenac sodium 2% topical solution versus control (vehicle only) in patients aged 40 to 85 years with radiographically confirmed primary OA of the knee. ClinicalTrials.gov identifier NCT01119898. The primary efficacy outcome was change from baseline to the final visit in the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscale. Secondary outcomes included additional WOMAC subscales and patient global assessment of OA. Treatment-emergent adverse events (TEAEs), skin irritation, and vital signs were assessed and collected throughout the study. Of 260 patients randomized, 259 received ≥1 dose of study drug. Significantly greater reductions in least-squares mean (standard error) WOMAC pain scores were observed for diclofenac-treated (-4.4 [0.4]) versus vehicle-treated patients (-3.4 [0.4]) at the final visit (p = 0.040). The most commonly reported TEAEs were administration site conditions. The vehicle-treated group experienced slightly more TEAEs than the active treatment group (38.8% vs. 31.5%). No serious adverse events were reported. Administration of diclofenac sodium 2% topical solution BID resulted in significantly greater improvement in pain reduction in patients with OA of the knee versus vehicle

  19. The Use of Sodium Hypochlorite Solution for (n,γ99Mo/99mTc Generator Based on Zirconium-Based Material (ZBM

    Directory of Open Access Journals (Sweden)

    I. Saptiama

    2015-08-01

    Full Text Available The many problems in preparing fission product 99Mo led into this work to develop 99Mo/99mTc generator using neutron-irradiated natural MoO3 targets and, more specifically, to develop a zirconium-based material (ZBM for chromatography columns that have an adsorption capacity of more than 100 mg Mo/g ZBM. This paper reports our recent experiments in the use of sodium hypochlorite solution of various concentrations to improve the yield of 99mTc in performance of (n,γ99Mo/99mTc generators based on the ZBM. The synthesized ZBM was coated with tetraethyl orthosilicate for improving the hardness of the material. The adsorption of [99Mo]molybdate into ZBM was carried out by reacting ZBM into [99Mo]molybdate solution at 90°C to form ZBM-[99Mo] molybdate. ZBM-[99Mo]molybdate was then packed into generator column, then eluted with 10 × 1 mL of saline followed by 1 × 5 mL of NaOCl solution. The NaOCl solution concentrations used were 0.5%; 1%; 3%; and 5% for each column, respectively. This study resulted in a ZBM which has a 99Mo adsorption capacity of 167.5 ± 3.4 mgMo/g ZBM, as well as in a yield eluate of 99mTc of up to 70%, and the find that the optimum NaOCl concentration was 3%. The use of sodium hypochlorite solution affected 99Mo breakthrough. The higher sodium hypochlorite concentration used, the more 99Mo breaktrough exist on 99mTc eluate.

  20. Unique properties of α-NaFeO{sub 2}: De-intercalation of sodium via hydrolysis and the intercalation of guest molecules into the extract solution

    Energy Technology Data Exchange (ETDEWEB)

    Monyoncho, Evans; Bissessur, Rabin, E-mail: rabissessur@upei.ca

    2013-07-15

    Graphical abstract: - Highlights: • Facile de-intercalating Na from NaFeO2. • Formation of layered sodium hydrogen carbonate hydrate. • Intercalation chemistry on layered sodium hydrogen carbonate hydrate. - Abstract: We report on a versatile method for the de-intercalation of Na from α-NaFeO{sub 2} by using water to produce α-Na{sub 1−x}FeO{sub 2}, where x ≈ 1. This de-intercalation technique provides an excellent route to ion exchange Na with other metal ions in α-NaFeO{sub 2}. The hydrolysis mechanism is provided. We show that the extracted solution captures CO{sub 2} from the atmosphere leading to the formation of sodium hydrogen carbonate hydrate crystals. The lamellar structure of the hydrate crystals was confirmed by powder X-ray diffraction, and were found Na-deficient via elemental analysis. Intercalation of guest molecules such as polymers, alcohols, and inorganic ions into the gallery space of the newly formed sodium hydrogen carbonate hydrate crystals was demonstrated by the use of powder X-ray diffraction technique. The reported materials were also characterized by Mössbauer spectroscopy, thermogravimetric analysis, differential scanning calorimetry, infrared spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy.

  1. The preparation of lithium aluminate by the hydrolysis of lithium and aluminum alkoxides

    International Nuclear Information System (INIS)

    Turner, C.W.; Clatworthy, B.C.; Gin, A.Y.H.

    1987-10-01

    Lithium aluminate was prepared by heating the hydrolysis products from various combinations of lithium and aluminum alkoxides under an atmosphere of nitrogen. The product was β-LiA1O 2 when aluminum iso-propoxide was a starting material, whereas γ-LiA1O 2 was the product for preparations starting with aluminum n-butoxide. The results were independent of the choice of lithium alkoxide. The hydrolysis of aluminum sec-butoxide with a solution of LiOH led to the γ phase as well. The temperature at which the γ phase developed depended upon the conditions of the hydrolysis reaction and was observed at a temperature as low as 550 degrees Celcius

  2. THERMOCHEMISTRY OF INTERACTION REACTIONS FOR SODIUM AND ALUMINUM SULPHATES WITH COMPONENTS OF HYDRATING PORTLAND CEMENT

    Directory of Open Access Journals (Sweden)

    P. I. Yukhnevskiy

    2018-01-01

    Full Text Available Chemical additives are widely used in the technology of concrete with the purpose to solve various problems and sulphate-containing additives-electrolytes are also used as accelerators for setting and hardening of cement. Action mechanism of additive accelerators for setting and hardening of cement is rather complicated and can not be considered as well-established. An influence of sulfate-containing additives such as sodium sulfate is reduced to acceleration of cement silicate phase hydration by increasing ionic strength of the solution. In addition to it, exchange reactions of anion additive with portlandite phase (Ca(OH2 and aluminate phases of hardening cement have a significant effect on hardening process that lead to formation of readily soluble hydroxides and hardly soluble calcium salts. The influence of sulfate-containing additives on properties of water cement paste and cement stone is quite diverse and depends on salt concentration and cation type. For example, the action of the aluminum sulphate additive becomes more complicated if the additive is subjected to hydrolysis in water, which is aggravated in an alkaline medium of the water cement paste. Formation of hydrolysis products and their reaction with aluminate phases and cement portlandite lead to a significant acceleration of setting. Thus, despite the similarity of additives ensuring participation of anions in the exchange reactions, the mechanism of their influence on cement setting and hardening varies rather significantly. The present paper considers peculiar features concerning the mechanism of interaction of sodium and aluminum sulfate additives in cement compositions from the viewpoint of thermochemistry. Thermochemical equations for reactions of sulfate-containing additives with phases of hydrated cement clinker have been given in the paper. The paper contains description how to calculate thermal effects of chemical reactions and determine an influence of the formed

  3. Indigenous technology development and standardization of the process for obtaining ready to use sterile sodium pertechnetate-Tc-99m solution from Geltech generator

    International Nuclear Information System (INIS)

    Sarkar, Sishir Kumar; Kothalkar, Chetan; Naskar, Prabhakar; Joshi, Sangeeta; Saraswathy, Padmanabhan; Dey, Arun Chandra; Vispute, Gunvant Leeladhar; Murhekar, Vishwas Vinayak; Pilkhwal, Neelam

    2013-01-01

    The indigenous design and technology development for processing large scale zirconium molybdate-Mo-99 (ZrMo-99) Geltech generator was successfully commissioned in Board of Radiation and Isotope Technology (BRIT), India, in 2006. The generator production facility comprises of four shielded plant facilities equipped with tongs and special process gadgets amenable for remote operations for radiochemical processing of ZrMo-99 gel. Over 2800 Geltech generators have been processed and supplied to user hospitals during the period 2006-2013. Geltech generator supplied by BRIT was initially not sterile. Simple elution of 99m Tc is performed by a sterile evacuated vial with sterile and pyrogen free 0.9% NaCl solution to obtain sodium ( 99m Tc) pertechnetate solution. A special type online 0.22 μm membrane filter has been identified and adapted in Geltech generator. The online filtration of 99m Tc from Geltech generator; thus, provided sterile 99m Tc sodium pertechnetate solution. Generators assembled with modified filter assembly were supplied to local hospital in Mumbai (Radiation Medicine Centre (RMC) and S.G.S. Medical College and KEM Hospital) and excellent performances were reported by users. (author)

  4. Indigenous technology development and standardization of the process for obtaining ready to use sterile sodium pertechnetate-Tc-99m solution from Geltech generator.

    Science.gov (United States)

    Sarkar, Sishir Kumar; Kothalkar, Chetan; Naskar, Prabhakar; Joshi, Sangeeta; Saraswathy, Padmanabhan; Dey, Arun Chandra; Vispute, Gunvant Leeladhar; Murhekar, Vishwas Vinayak; Pilkhwal, Neelam

    2013-04-01

    The indigenous design and technology development for processing large scale zirconium molybdate-Mo-99 (ZrMo-99) Geltech generator was successfully commissioned in Board of Radiation and Isotope Technology (BRIT), India, in 2006. The generator production facility comprises of four shielded plant facilities equipped with tongs and special process gadgets amenable for remote operations for radiochemical processing of ZrMo-99 gel. Over 2800 Geltech generators have been processed and supplied to user hospitals during the period 2006-2013. Geltech generator supplied by BRIT was initially not sterile. Simple elution of Tc-99m is performed by a sterile evacuated vial with sterile and pyrogen free 0.9% NaCl solution to obtain sodium (Tc-99m) pertechnetate solution. A special type online 0.22 μm membrane filter has been identified and adapted in Geltech generator. The online filtration of Tc-99m from Geltech generator; thus, provided sterile Tc-99m sodium pertechnetate solution. Generators assembled with modified filter assembly were supplied to local hospital in Mumbai Radiation Medicine Centre (RMC) and S.G.S. Medical College and KEM Hospital) and excellent performances were reported by users.

  5. The impact of functionalized CNT in the network of sodium alginate-based nanocomposite beads on the removal of Co(II) ions from aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Karkeh-abadi, Fatemeh [Department of Chemistry, University of Kashan, Kashan (Iran, Islamic Republic of); Saber-Samandari, Samaneh, E-mail: samaneh.saber@gmail.com [Department of Chemistry, Eastern Mediterranean University, Gazimagusa, TRNC via Mersin 10 (Turkey); Saber-Samandari, Saeed, E-mail: saeedss@aut.ac.ir [New Technologies Research Center, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of)

    2016-07-15

    Highlights: • The sodium alginate-hydroxyapatite-CNT nanocomposite beads were prepared. • Amide functionalized CNT imprinted in the network of sodium alginate containing HAp. • The prepared beads were used as adsorbents of cobalt ions from an aqueous solution. • The adsorption was fit with the Freundlich isotherm and second-order kinetic models. • The endothermic adsorption process is spontaneous and thermodynamically favorable. - Abstract: Significant efforts have been made to develop highly efficient adsorbents to remove radioactive Co(II) ion pollutants from medical and industrial wastewaters. In this study, amide group functionalized multi-walled carbon nanotube (CNT-CONH{sub 2}) imprinted in the network of sodium alginate containing hydroxyapatite, and new nanocomposite beads were synthesized. Then, they were characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS). The prepared nanocomposite beads were used as an adsorbent of Co(II) ions from an aqueous solution. The presence and distribution of Co(II) ions in the surface of the nanocomposite beads was confirmed using FESEM, EDS and metal mapping analysis. The effect of various experimental conditions such as time, pH, and initial concentration of the adsorbate solution and temperature on the adsorption capacity of the nanocomposite beads were explored. The maximum Co(II) ions adsorption capacity of the prepared nanocomposite beads with the largest surface area of 163.4 m{sup 2} g{sup −1} was 347.8 mg g{sup −1} in the optimized condition. The adsorption mechanism followed a pseudo-second-order kinetic model. Furthermore, the Freundlich appears to produce better fit than the Langmuir adsorption isotherm. Finally, thermodynamic studies suggest that endothermic adsorption process of Co(II) ions is spontaneous and

  6. Chitosan-collagen biomembrane embedded with calcium-aluminate enhances dentinogenic potential of pulp cells

    Directory of Open Access Journals (Sweden)

    Diana Gabriela SOARES

    2016-01-01

    Full Text Available Abstract The development of biomaterials capable of driving dental pulp stem cell differentiation into odontoblast-like cells able to secrete reparative dentin is the goal of current conservative dentistry. In the present investigation, a biomembrane (BM composed of a chitosan/collagen matrix embedded with calcium-aluminate microparticles was tested. The BM was produced by mixing collagen gel with a chitosan solution (2:1, and then adding bioactive calcium-aluminate cement as the mineral phase. An inert material (polystyrene was used as the negative control. Human dental pulp cells were seeded onto the surface of certain materials, and the cytocompatibility was evaluated by cell proliferation and cell morphology, assessed after 1, 7, 14 and 28 days in culture. The odontoblastic differentiation was evaluated by measuring alkaline phosphatase (ALP activity, total protein production, gene expression of DMP-1/DSPP and mineralized nodule deposition. The pulp cells were able to attach onto the BM surface and spread, displaying a faster proliferative rate at initial periods than that of the control cells. The BM also acted on the cells to induce more intense ALP activity, protein production at 14 days, and higher gene expression of DSPP and DMP-1 at 28 days, leading to the deposition of about five times more mineralized matrix than the cells in the control group. Therefore, the experimental biomembrane induced the differentiation of pulp cells into odontoblast-like cells featuring a highly secretory phenotype. This innovative bioactive material can drive other protocols for dental pulp exposure treatment by inducing the regeneration of dentin tissue mediated by resident cells.

  7. Study of damages by neutron irradiation in lithium aluminates

    International Nuclear Information System (INIS)

    Palacios G, O.

    1999-01-01

    Lithium aluminates proposed to the production of tritium in fusion nuclear reactors, due to the thermal stability that they present as well as the behavior of the aluminium to the irradiation. As a neutron flux with profile (≅ 14 Mev) of a fusion reactor is not available. A irradiation experiment was designed in order to know the micro and nano structure damages produced by fast and thermal neutrons in two irradiation positions of the fusion nuclear reactor Triga Mark III: CT (Thermal Column) and SIFCA (System of Irradiation Fixed of Capsules). In this work samples of lithium aluminate were characterized by XRD (X-Ray Diffraction), TEM (Transmission Electron Microscopy) and SEM (Scanning Electron Microscopy). Two samples were prepared by two methods: a) coalition method and b) peroxide method. This characterization comprised original and irradiated samples. The irradiated sample amounted to 4 in total: one for each preparation method and one for each irradiation position. The object of this analysis was to correlate with the received neutron dose the damages suffered by the samples with the neutron irradiation during long periods (440 H), in their micro and nano structure aspects; in order to understand the changes as a function of the irradiation zone (with thermal and fast neutron flux) and the preparation methods of the samples and having as an antecedent the irradiation in SIFCA position by short times (2h). The obtained results are referred to the stability of γ -aluminate phase, under given conditions of irradiation and defined nano structure arrangement. They also refer to the proposals of growth mechanism and nucleation of new phases. The error associated with the measurement of neutron dose is also discussed. (Author)

  8. Aluminized film, seam sealing tests and observations. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1994-06-16

    The purpose of this work was to investigate various seam sealing techniques, reinforcing methods, fitting installations, seam tolerances and geometric configurations pertinent to an aluminized plastic laminate. The program seeks a successful fabricating method for producing low-diffusion, cylindrical, spar liners to contain pressurized GH{sub 2} and GO{sub 2}. The test plan included: (1) seaming techniques on metallized Mylar film; (2) ``double patches`` for end fittings; (3) stainless steel bulkhead fitting assembly with seals; (4) minimum run tolerance on linear shear seam; (5) peel seam vs. inverted seal seam fabrication.

  9. System and process for aluminization of metal-containing substrates

    Energy Technology Data Exchange (ETDEWEB)

    Chou, Yeong-Shyung; Stevenson, Jeffry W.

    2017-12-12

    A system and method are detailed for aluminizing surfaces of metallic substrates, parts, and components with a protective alumina layer in-situ. Aluminum (Al) foil sandwiched between the metallic components and a refractory material when heated in an oxidizing gas under a compression load at a selected temperature forms the protective alumina coating on the surface of the metallic components. The alumina coating minimizes evaporation of volatile metals from the metallic substrates, parts, and components in assembled devices that can degrade performance during operation at high temperature.

  10. Thermal Properties of Double-Aluminized Kapton at Low Temperatures

    Science.gov (United States)

    Tuttle, J.; DiPirro, M.; Canavan, E.; Hait, T.

    2007-01-01

    Double-aluminized kapton (DAK) is commonly used in multi-layer insulation blankets in cryogenic systems. NASA plans to use individual DAK sheets in lightweight deployable shields for satellites carrying instruments. A set of these shields will reflect away thermal radiation from the sun, the earth, and the instrument's warm side and allow the instrument's cold side to radiate its own heat to deep space. In order to optimally design such a shield system, it is important to understand the thermal characteristics of DAK down to low temperatures. We describe experiments which measured the thermal conductivity and electrical resistivity down to 4 Kelvin and the emissivity down to 10 Kelvin.

  11. Release of the Diclofenac Sodium by Nanofibers of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate Obtained from Electrospinning and Solution Blow Spinning

    Directory of Open Access Journals (Sweden)

    Michelle Andrade Souza

    2014-01-01

    Full Text Available Electrospun fibers are explored as a new system for controlled drug delivery. Novel techniques capable of obtaining polymer nanofibers have been reported in the literature. They include solution blow spinning (SBS, which is a technique to produce polymer nanofibers in the same range as electrospinning, using pressurized gas instead of high voltage. The present study investigates release characteristics of diclofenac sodium encapsulated at three concentrations (5, 10, and 20% w/v in poly(3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV nanofibers made by electrospinning and SBS and determines the drug’s effect on fiber morphology and structural properties. PHBV nanofibers were characterized using scanning electronic microscopy, differential scanning calorimetry, and X-ray diffraction, and the release profile was examined via UV-Vis spectrophotometry. Both electrospinning and SBS encapsulated diclofenac sodium in PHBV membranes efficiently and effectively. The profile of the in vitro release of diclofenac sodium was dependent on drug concentration and temperature. The drug reduced crystallinity and increased flexibility.

  12. The removal of Tartrazine dye by modified Alumina with sodium dodecyl sulfate from aqueous solutions: equilibrium and thermodynamic studies

    OpenAIRE

    A. Parchebaf Jadid; S. Sadeghi

    2017-01-01

    Edible colors are materials which in the case of adding to food and drinks cause transferring color to them. Most of these colors are not acceptable in terms of applying in human food and underlies various diseases like gastrointestinal disorders, renal, liver and blood toxicity. The goal of this study was investigating the efficiency of improved alumina by sodium dodecyl sulfate (SDS) in eliminating Tartrazine from aqueous environments. In this research, the impact of effective parameters su...

  13. The salting-out effect and phase separation in aqueous solutions of tri-sodium citrate and 1-butyl-3-methylimidazolium bromide

    Energy Technology Data Exchange (ETDEWEB)

    Sadeghi, Rahmat, E-mail: rsadeghi@uok.ac.i [Department of Chemistry, University of Kurdistan, Sanandaj (Iran, Islamic Republic of); Golabiazar, Roonak [Department of Chemistry, University of Kurdistan, Sanandaj (Iran, Islamic Republic of); Shekaari, Hemayat [Department of Chemistry, Faculty of Science, University of Mohaghegh Ardabili, Ardabil (Iran, Islamic Republic of)

    2010-04-15

    The aim of this work is to obtain further evidence about the salting-out effect produced by the addition of tri-sodium citrate to aqueous solutions of water miscible ionic liquid 1-butyl-3-methylimidazolium bromide ([C{sub 4}mim][Br]) by evaluating the effect of tri-sodium citrate on the thermodynamic properties of aqueous solutions of this ionic liquid. Experimental measurements of density and sound velocity at different temperatures ranging from (288.15 to 308.15) K, the refractive index at 308.15 K and the liquid-liquid phase diagram at different temperatures ranging from (288.15 to 338.15) K for aqueous solutions containing 1-butyl-3-methylimidazolium bromide ([C{sub 4}mim][Br]) and tri-sodium citrate (Na{sub 3}Cit) are taken. The apparent molar volume of transfer of [C{sub 4}mim][Br] from water to aqueous solutions of Na{sub 3}Cit have positive values and it increases by increasing salt molality. Although at high IL molality, the apparent molar isentropic compressibility shows similar behaviour with that of the apparent molar volume. However at low concentrations of IL, the apparent molar isentropic compressibility of transfer of [C{sub 4}mim][Br] from water to aqueous solutions of Na{sub 3}Cit have negative values. The effects of temperature and the addition of Na{sub 3}Cit and [C{sub 4}mim][Br] on the liquid-liquid phase diagram of the investigated system have been studied. It was found that an increase in temperature caused the expansion of the one-phase region. The presence of Na{sub 3}Cit triggers a salting-out effect, leading to significant upward shifts of the liquid-liquid de-mixing temperatures of the system. The effect of temperature on the phase-forming ability in the system investigated has been studied based on a salting-out coefficient obtained from fitting the binodal values to a Setschenow-type equation for each temperature. Based on cloud point values, the energetics of the clouding process have been estimated and it was found that both of

  14. The salting-out effect and phase separation in aqueous solutions of tri-sodium citrate and 1-butyl-3-methylimidazolium bromide

    International Nuclear Information System (INIS)

    Sadeghi, Rahmat; Golabiazar, Roonak; Shekaari, Hemayat

    2010-01-01

    The aim of this work is to obtain further evidence about the salting-out effect produced by the addition of tri-sodium citrate to aqueous solutions of water miscible ionic liquid 1-butyl-3-methylimidazolium bromide ([C 4 mim][Br]) by evaluating the effect of tri-sodium citrate on the thermodynamic properties of aqueous solutions of this ionic liquid. Experimental measurements of density and sound velocity at different temperatures ranging from (288.15 to 308.15) K, the refractive index at 308.15 K and the liquid-liquid phase diagram at different temperatures ranging from (288.15 to 338.15) K for aqueous solutions containing 1-butyl-3-methylimidazolium bromide ([C 4 mim][Br]) and tri-sodium citrate (Na 3 Cit) are taken. The apparent molar volume of transfer of [C 4 mim][Br] from water to aqueous solutions of Na 3 Cit have positive values and it increases by increasing salt molality. Although at high IL molality, the apparent molar isentropic compressibility shows similar behaviour with that of the apparent molar volume. However at low concentrations of IL, the apparent molar isentropic compressibility of transfer of [C 4 mim][Br] from water to aqueous solutions of Na 3 Cit have negative values. The effects of temperature and the addition of Na 3 Cit and [C 4 mim][Br] on the liquid-liquid phase diagram of the investigated system have been studied. It was found that an increase in temperature caused the expansion of the one-phase region. The presence of Na 3 Cit triggers a salting-out effect, leading to significant upward shifts of the liquid-liquid de-mixing temperatures of the system. The effect of temperature on the phase-forming ability in the system investigated has been studied based on a salting-out coefficient obtained from fitting the binodal values to a Setschenow-type equation for each temperature. Based on cloud point values, the energetics of the clouding process have been estimated and it was found that both of entropy and enthalpy are the driving forces

  15. A comparative evaluation of antibacterial effectiveness of sodium hypochlorite, Curcuma longa, and Camellia sinensis as irrigating solutions on isolated anaerobic bacteria from infected primary teeth.

    Science.gov (United States)

    Dhariwal, Neha Shashikant; Hugar, Shivayogi M; Harakuni, Sheetal; Sogi, Suma; Assudani, Harsha G; Mistry, Laresh Naresh

    2016-01-01

    In endodontics, most of the commercial intra-canal medicaments have cytotoxic reactions and because of their inability to eliminate bacteria from dentinal tubules, recent medicine has turned its attention to the usage of biologic medication prepared from natural plants. The literature to testify the efficacy of natural alternatives in primary teeth is meagre and its effects as irrigating solutions need to be evaluated. To evaluate the antibacterial effectiveness of sodium hypochlorite, ethanolic extracts of Curcuma longa (turmeric) and Camellia sinensis (green tea) as irrigating solutions against the anaerobic bacteria isolated from the root canals of infected primary teeth. Thirty patients were selected based on the selected inclusion and exclusion criteria. Preoperative radiographs were taken. Rubber dam isolation and working length estimation were done, following which thirty samples were taken from the root canals of infected primary teeth using sterile absorbent paper points and transferred to tubes containing thioglycolate transport medium. The bacteria were then isolated using standard microbiological protocols and were subjected to antibiotic sensitivity testing using the three test irrigants. SPSS 18 software using Chi-square test was used for statistical analysis. The most commonly isolated bacteria included Porphyromonas sp., Bacteroides fragilis, Peptostreptococcus, and Staphylococcus aureus. Sodium hypochlorite and C. longa (turmeric) showed good antibacterial effect and were effective against most of the isolated bacteria. There was statistically significant difference in the antibacterial effect among the three tested groups (P < 0.001). The least effective was C. sinensis (green tea). The infected primary teeth almost always present with a polymicrobial structure with a wide variety of anaerobic bacteria. The chemo-mechanical preparation plays an important role in eradicating the population of predominant micro-organisms in treating these teeth with

  16. Effect of metal ion hydration on the interaction between sodium carboxylates and aluminum(III) or chromium(III) ions in aqueous solution.

    Science.gov (United States)

    Pereira, Rui F P; Tapia, Maria J; Valente, Artur J M; Burrows, Hugh D

    2012-01-10

    The interaction between sodium octanoate, decanoate, and dodecanoate and aluminum(III) and chromium(III) has been studied in water at natural pH values, starting well below the surfactant critical micelle concentration, using electrical conductivity, turbidity, and potentiometric measurements. With decanoate or dodecanoate, maximum interaction occurs at 3:1 stoichiometry, corresponding to charge neutralization. Although the solutions become turbid with both metal ions, indicating phase separation, differences are observed and attributed to the fact that aluminum(III) is relatively labile to substitution and rapidly replaces its water ligands, whereas chromium(III) is substitution inert. This shows up in well-defined floc formation with Al(3+), whereas Cr(3+) suspensions do not precipitate, probably because that replacement of coordinated water by carboxylate ligands is impeded. This can be overcome by increasing temperature, and differences in the thermal behavior with Al(3+) and Cr(3+) are suggested to be due to increased involvement of substitution reactions in the latter case. The effect of octanoate on the trivalent metal ions is less clear, and with Cr(3+) interaction only occurs when the carboxylate is in excess. Hydrophobic interactions between alkyl chains play a major role in driving phase separation. At high surfactant concentrations, the solid phases do not dissolve, in contrast to what is observed with the corresponding alkylsulfates. This has implications for use of these systems in metal separation through froth flotation. The concentration of metal ions in supernatant solution has been determined for sodium dodecanoate and sodium dodecylsulfate with Al(3+) and Cr(3+) over the whole surfactant concentration range by inductively coupled plasma-mass spectrometry (ICP-MS). From this, association constants have been determined and are found to be larger for the carboxylate than the alkylsulfate, in agreement with the greater Lewis basicity of the -CO(2

  17. A comparative evaluation of antibacterial effectiveness of sodium hypochlorite, Curcuma longa, and Camellia sinensis as irrigating solutions on isolated anaerobic bacteria from infected primary teeth

    Directory of Open Access Journals (Sweden)

    Neha Shashikant Dhariwal

    2016-01-01

    Full Text Available Context: In endodontics, most of the commercial intra-canal medicaments have cytotoxic reactions and because of their inability to eliminate bacteria from dentinal tubules, recent medicine has turned its attention to the usage of biologic medication prepared from natural plants. The literature to testify the efficacy of natural alternatives in primary teeth is meagre and its effects as irrigating solutions need to be evaluated. Aim: To evaluate the antibacterial effectiveness of sodium hypochlorite, ethanolic extracts of Curcuma longa (turmeric and Camellia sinensis (green tea as irrigating solutions against the anaerobic bacteria isolated from the root canals of infected primary teeth. Materials and Methods: Thirty patients were selected based on the selected inclusion and exclusion criteria. Preoperative radiographs were taken. Rubber dam isolation and working length estimation were done, following which thirty samples were taken from the root canals of infected primary teeth using sterile absorbent paper points and transferred to tubes containing thioglycolate transport medium. The bacteria were then isolated using standard microbiological protocols and were subjected to antibiotic sensitivity testing using the three test irrigants. Statistical Analysis: SPSS 18 software using Chi-square test was used for statistical analysis. Results: The most commonly isolated bacteria included Porphyromonas sp., Bacteroides fragilis, Peptostreptococcus, and Staphylococcus aureus. Sodium hypochlorite and C. longa (turmeric showed good antibacterial effect and were effective against most of the isolated bacteria. There was statistically significant difference in the antibacterial effect among the three tested groups (P < 0.001. The least effective was C. sinensis (green tea. Conclusion: The infected primary teeth almost always present with a polymicrobial structure with a wide variety of anaerobic bacteria. The chemo-mechanical preparation plays an important

  18. Aluminous Minerals for Caustic Processing of Scheelite Concentrate

    Science.gov (United States)

    Chen, Min; Li, Zhao; Li, Xuewei; Qu, Jun; Zhang, Qiwu

    2017-06-01

    Dry milling of the mixture of scheelite concentrate and solid NaOH is conducted to develop a caustic process for tungsten (W) extraction. Aluminum hydroxide (Al(OH)3) is further added to the milling to control the calcium dissolution of one reaction product, calcium hydroxide, in the next aqueous extraction of soluble tungstate to form an insoluble substance. For practical application, several aluminous minerals of kaolin, gibbsite, and diaspore with different alumina concentrations and water percentages are used to replace the pure chemical Al(OH)3, and the feasibility of using these minerals as calcium immobilization additives is confirmed to give rise to the formation of Na2WO4 and water-insoluble katoite (Ca3Al2(SiO4)3- x (OH)4 x ) in the form of powders. Tungsten recovery is found to depend on the compositions of the used mineral, and the conditions for improving W recovery are studied with respect to the compositions of aluminum hydroxide and water inside the minerals. The developed process allows the caustic extraction of W by applying the nearby available aluminous minerals.

  19. Effect of sodium caproate on the volumetric and viscometric properties of glycine, DL-α-alanine, and DL-α-amino-n-butyric acid in aqueous solutions

    International Nuclear Information System (INIS)

    Wang Jianji; Yan Zhenning; Lu Jinsuo

    2004-01-01

    The apparent molar volumes (V m,2 ) and relative viscosities (η r ) at T=(298.15 and 308.15) K have been obtained for glycine, DL-α-alanine, and DL-α-amino-butyric acid in aqueous sodium caproate solutions from measurements of density and the flow time. The standard partial molar volumes (V 0 m,2 ), standard volumes of transfer (Δ t V 0 ), the viscosity B-coefficients, and the activation thermodynamic quantities (Δμ 2 0≠ and ΔS 2 0≠ ) of viscous flow have been calculated for the amino acids. It is shown that the standard partial molar volumes, viscosity B-coefficients, and activation free energies for viscous flow increase with increasing number of carbon atoms in the alkyl chain of the amino acids. An increase in V 0 m,2 and Δ t V 0 with increasing electrolyte concentrations have been explained due to the interactions of sodium caproate with the charged center of zwitterions for the amino acids. A comparison of the V 0 m,2 values for glycine, DL-α-alanine, and DL-α-aminon-n-butyric acid in different aqueous salts solutions showed that carboxylate ions have stronger interactions with amino acid than chloride, thiocyanate, and nitrate ions. Results of viscosity are discussed in terms of changes in solvent structure

  20. Synergistic effects of sodium lauroyl sarcosinate and glutamic acid in inhibition assembly against copper corrosion in acidic solution

    Science.gov (United States)

    Yu, Yinzhe; Zhang, Daquan; Zeng, Huijing; Xie, Bin; Gao, Lixin; Lin, Tong

    2015-11-01

    A self-assembled multilayer (SAM) from sodium lauroyl sarcosinate (SLS) and glutamic acid (GLU) is formed on copper surface. Its inhibition ability against copper corrosion is examined by electrochemical analysis and weight loss test. In comparison to SAM formed by just SLS or GLU, a synergistic effect is observed when the coexistence of SLS and GLU in SAM. The SLS/GLU SAM has an acicular multilayer structure, and SAM prepared under the condition of 5 mM SLS and 1 mM GLU shows the best protection efficiency. PM6 calculation reveals that the synergistic effect stems from interactions between SLS, GLU and cupric ions.

  1. Evaluating interaction forces between BSA and rabbit anti-BSA in sulphathiazole sodium, tylosin and levofloxacin solution by AFM

    Science.gov (United States)

    Wang, Congzhou; Wang, Jianhua; Deng, Linhong

    2011-11-01

    Protein-protein interactions play crucial roles in numerous biological processes. However, it is still challenging to evaluate the protein-protein interactions, such as antigen and antibody, in the presence of drug molecules in physiological liquid. In this study, the interaction between bovine serum albumin (BSA) and rabbit anti-BSA was investigated using atomic force microscopy (AFM) in the presence of various antimicrobial drugs (sulphathiazole sodium, tylosin and levofloxacin) under physiological condition. The results show that increasing the concentration of tylosin decreased the single-molecule-specific force between BSA and rabbit anti-BSA. As for sulphathiazole sodium, it dramatically decreased the specific force at a certain critical concentration, but increased the nonspecific force as its concentration increasing. In addition, the presence of levofloxacin did not greatly influence either the specific or nonspecific force. Collectively, these results suggest that these three drugs may adopt different mechanisms to affect the interaction force between BSA and rabbit anti-BSA. These findings may enhance our understanding of antigen/antibody binding processes in the presence of drug molecules, and hence indicate that AFM could be helpful in the design and screening of drugs-modulating protein-protein interaction processes.

  2. Thermodynamic solution properties of pefloxacin mesylate and its interactions with organized assemblies of anionic surfactant, sodium dodecyl sulphate

    International Nuclear Information System (INIS)

    Usman, Muhammad; Rashid, Muhammad Abid; Mansha, Asim; Siddiq, Mohammad

    2013-01-01

    Graphical abstract: - Highlights: • Free energy of adsorption is more negative than free energy of micellization. • Micellization becomes more spontaneous at high temperature. • There is strong interaction between PFM and SDS. - Abstract: This manuscript reports the physicochemical behavior of antibiotic amphiphilic drug pefloxacin mesylate (PFM) and its interaction with anionic surfactant, sodium dodecyl sulfate (SDS). The data of surface tension and electrical conductivity are helpful to detect the CMC as well as to calculate surface parameters, i.e. surface pressure, π, surface excess concentration, Γ, area per molecule of drug and standard Gibbs free energy of adsorption, ΔG ads and thermodynamic parameters like standard free energy of micellization, ΔG m , standard enthalpy of micellization, ΔH m and standard entropy of micellization, ΔS m . The interaction of this drug with anionic surfactant, sodium dodecyl sulfate (SDS) was studied by electrical conductivity and UV/visible spectroscopy. This enabled us to compute the values of partition coefficient (K x ), free energy of partition, ΔG p , binding constant, K b , free energy of binding, ΔG b , number of drug molecules per micelle, n, and thermodynamic parameters of drug–surfactant interaction

  3. Self-aggregation behavior of hydrophobic sodium alginate derivatives in aqueous solution and their application in the nanoencapsulation of acetamiprid.

    Science.gov (United States)

    Zhao, Xinyu; Li, Jiacheng; Feng, Yuhong; Yu, Gaobo; Zhou, Qingfeng; He, Furui; Xiao, Dunchao; Chen, Kai; Zhang, Lei

    2018-01-01

    In this study, cholesteryl-grafted sodium alginate derivatives (CSAD) with different molecular weights were synthesized by esterification. The structure of CSAD was confirmed by FT-IR and 1 H NMR spectrometers. The effects of pH and CSAD polymer concentration on the self-assembled behavior and particle size of CSAD were investigated by fluorescence measurement (FM) and dynamic light scattering (DLS). In the presence of Ca 2+ , the cholesteryl-grafted sodium alginate derivative was used for fabricating self-assembled nanoparticles that can effectively encapsulate the drug acetamiprid. The drug-loaded nanoparticles were characterized by transmission electron microscopy (TEM). The encapsulation efficiency (EE) and acetamiprid drug release behavior from the nanoparticles were also studied. The results reveal that CSAD self-assembled nanoparticles had a diameter of 100nm and were nonaggregated in aqueous media; Moreover, the encapsulation efficiency and the release behavior of nanoparticles were influenced by the MW of CSAD. The mechanism of acetamiprid release was found to vary from non-Fickian (anomalous) to Fickian transport with a decrease in the molecular weight of CSAD. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Production of zeolite A come from rio Capim Kaolin: Study on recycle of sodium hydroxide solution; Producao de zeolita A, a partir de caulim do rio Capim: estudo do reciclo da solucao de hidroxido de sodio

    Energy Technology Data Exchange (ETDEWEB)

    Moraes, C.G.; Rodrigues, E.C.; Rocha Junior, C.A.F.; Macedo, E.N.; Neves, R.F., E-mail: crisqi02@gmail.com [Universidade Federal do Para (UFPA), Belem, PA (Brazil)

    2011-07-01

    The kaolin processing industry is an important economic sector in the State of Para, but produces huge amounts of wastes composed essentially of kaolinite. The production processes of zeolites typically use sodium hydroxide in excess, are discarded. So the objective is the development process for production of zeolite A which allows the reuse of the solution of sodium hydroxide used in excess through your recycling. Presents the results of XRD, SEM of the zeolites produced in five consecutive cycles performed at a temperature of 110°C/24h as a source of sodium hydroxide solution of sodium 5 M, using a molar ratio of Si/Al = 1 and Na/Al = 1,26. (author)

  5. Structural and phase transition changes of sodium dodecyl sulfate micellar solution in alcohols probed by small-angle neutron scattering (SANS)

    International Nuclear Information System (INIS)

    Putra, Edy Giri Rachman; Patriati, Arum

    2015-01-01

    Small-angle neutron scattering (SANS) measurements on 0.3M sodium dodecyl sulfate (SDS) micellar solutions have been performed in the presence of n-alcohols, from ethanol to decanol at different alcohol concentrations, 2–10 wt%. The ellipsoid micellar structure which occurred in the 0.3M SDS in aqueous solution with the size range of 30–50 Å has different behavior at various hydrocarbon chain length and concentration of alcohols. At low concentration and short chain-length of alcohols, such as ethanol, propanol, and butanol, the size of micelles reduced and had a spherical-like structure. The opposite effect occurred as medium to long chain alcohols, such as hexanol, octanol and decanol was added into the 0.3M SDS micellar solutions. The micelles structure changed to be more elongated in major axis and then crossed the critical phase transition from micellar solution into liquid crystal phase as lamellar structure emerged by further addition of alcohols. The inter-lamellar distances were also depending on the hydrocarbon chain length and concentration of alcohols. In the meantime, the persistent micellar structures occurred in addition of medium chain of n-alcohol, pentanol at all concentrations

  6. Structural and phase transition changes of sodium dodecyl sulfate micellar solution in alcohols probed by small-angle neutron scattering (SANS)

    Energy Technology Data Exchange (ETDEWEB)

    Putra, Edy Giri Rachman [Neutron Scattering Laboratory, National Nuclear Energy Agency of Indonesia (BATAN), Gedung 40 BATAN, Kawasan Puspiptek Serpong, Tangerang 15314 (Indonesia); Patriati, Arum [Neutron Scattering Laboratory, National Nuclear Energy Agency of Indonesia (BATAN), Gedung 40 BATAN, Kawasan Puspiptek Serpong, Tangerang 15314 (Indonesia); Department of Chemistry, Faculty of Mathematics and Natural Sciences, University of Gadjah Mada, Bulaksumur, Yogyakarta 55281, Indonesia giri@batan.go.id (Indonesia)

    2015-04-16

    Small-angle neutron scattering (SANS) measurements on 0.3M sodium dodecyl sulfate (SDS) micellar solutions have been performed in the presence of n-alcohols, from ethanol to decanol at different alcohol concentrations, 2–10 wt%. The ellipsoid micellar structure which occurred in the 0.3M SDS in aqueous solution with the size range of 30–50 Å has different behavior at various hydrocarbon chain length and concentration of alcohols. At low concentration and short chain-length of alcohols, such as ethanol, propanol, and butanol, the size of micelles reduced and had a spherical-like structure. The opposite effect occurred as medium to long chain alcohols, such as hexanol, octanol and decanol was added into the 0.3M SDS micellar solutions. The micelles structure changed to be more elongated in major axis and then crossed the critical phase transition from micellar solution into liquid crystal phase as lamellar structure emerged by further addition of alcohols. The inter-lamellar distances were also depending on the hydrocarbon chain length and concentration of alcohols. In the meantime, the persistent micellar structures occurred in addition of medium chain of n-alcohol, pentanol at all concentrations.

  7. Effect of equiosmolar solutions of hypertonic sodium lactate versus mannitol in craniectomy patients with moderate traumatic brain injury

    Directory of Open Access Journals (Sweden)

    Muhammad R. Ahmad

    2014-03-01

    Full Text Available Background: Brain relaxation and prevention from cerebral edema are essential in craniectomy. Osmotherapy with 20% mannitol are generally used to withdraw fluid from the brain parenchyma, however may cause hemodynamic fluctuation, due to increase diuresis. On the other hand 0.5 M hypertonic sodium lactate (HSL appeared as an alternative of osmotherapy. This study  aimed to observe the effect of hypertonic sodium lactate (HSL on brain relaxation, blood glucose level and hemodynamic variables in craniectomy due to moderate brain injury.Methods: A randomized controlled study of 42 cases with moderate brain injury, aged 18 - 65 years, ASA 1 - 3, between September-November 2012, was carried out. The patients were divided into group M (n = 21 that received 2.5 mL/kg 20% mannitol and group HSL that received 2.5 mL/kg 0.5M HSL. Mean arterial pressures (MAP, central venous pressures (CVP and urine output were measured after induction, and at 15, 30, 45, 60 min after infusion. Brain relaxation was assessed at a four-point scale after opening the duramater. Blood glucose levels were measured before induction and at 60 min after the infusion. Appropriate statistical tests were used for comparison. Unpaired t-test was used to compare hemodynamic and blood glucose level, and chi-square was used to compare brain relaxation.Results: MAP at 60 minute was significantly higher in HSL group than M group (81.66 ± 7.85 vs 74.33 ± 6.18 mmHg; p = 0.002. There was no difference in brain relaxation (p = 0.988. A significant increase in blood glucose level was observed in group HSL (17.95 ± 11.46 mg/dL; p = 0.001.Conclusion: Half-molar HSL was as effective as 20% mannitol in producing brain relaxation, with better hemodynamic stability and gave significant increase in blood glucose level.Keywords: brain relaxation, hemodynamic, hypertonic sodium lactate, mannitol, traumatic brain injury

  8. Method of winning aluminum metal from aluminous ore

    Science.gov (United States)

    Loutfy, R.O.; Keller, R.; Yao, N.P.

    Aluminous ore such as bauxite containing alumina is blended with coke or other suitable form of carbon and reacted with sulfur gas at an elevated temperature. For handling, the ore and coke can be extruded into conveniently sized pellets. The reaction with sulfur gas produces molten aluminum sulfide which is separated from residual solid reactants and impurities. The aluminum sulfide is further increased in temperature to cause its decomposition or sublimation, yielding aluminum subsulfide liquid (A1S) and sulfur gas that is recycled. The aluminum monosulfide is then cooled to below its disproportionation temperature to again form molten aluminum sulfide and aluminum metal. A liquid-liquid or liquid-solid separation, depending on the separation temperature, provides product aluminum and aluminum sulfide for recycle to the disproportionation step.

  9. New advances in the carbonation of aluminous cement. Alkaline hydrolisis

    Directory of Open Access Journals (Sweden)

    Fernández-Carrasco, L.

    1999-03-01

    Full Text Available The carbonation process of aluminous cement in presence of high alkali content is studied. In this work, the formation of a compound which formula is close to K4Al6(CO311-x(OH2x(H2Oy is shown for the studies samples. The aluminous cement carbonation in alkali presence take place, at least, in two stages. In a first stage the aluminium and potassium carbonate hydrate joint to CaCO3 is formed. Later, that aluminium potassium carbonate hydrate is developed toward the aluminium hydroxide formation.

    Se realiza un estudio del proceso de carbonatación del cemento aluminoso en presencia de una concentración elevada de álcalis. En el presente trabajo se demuestra la formación, en las muestras estudiadas, de un compuesto cuya fórmula es cercana a K4Al6(CO311-x(OH2x(H2Oy. La carbonatación del cemento aluminoso en presencia de álcalis tiene lugar, al menos, en dos etapas. La primera de ellas da lugar a la formación de un carbonato de aluminio y potasio hidratado junio a CaCO3 Posteriormente este carbonato de aluminio y potasio hidratado evoluciona hacia la formación de hidróxido de aluminio.

  10. Decomposition of Sodium Tetraphenylborate

    International Nuclear Information System (INIS)

    Barnes, M.J.

    1998-01-01

    The chemical decomposition of aqueous alkaline solutions of sodium tetraphenylborate (NaTPB) has been investigated. The focus of the investigation is on the determination of additives and/or variables which influence NaTBP decomposition. This document describes work aimed at providing better understanding into the relationship of copper (II), solution temperature, and solution pH to NaTPB stability

  11. Thermodynamic characteristics of the dissolution of glycine, glycylglycine, and glycylglycylglycine in aqueous solutions of sodium dodecyl sulfate at T = 298.15 K

    Science.gov (United States)

    Smirnov, V. I.; Badelin, V. G.

    2017-09-01

    the enthalpies of dissolution of glycine (Gly), glycylglycine (GlyGly), and glycylglycylglycine (GlyGlyGly) are measured in aqueous solutions of sodium dodecyl sulfate (SDS) at SDS concentrations m = 0-0.7 mol kg-1 and T = 298.15 K by means of calorimetry. The obtained data are used to calculate the standard values of enthalpies of dissolution (Δsol H m ) and enthalpies of transfer (Δtr H m ) of glycine and its oligomers from water to SDS aqueous solutions. The dependences of Δsol H m and Δtr H m on SDS concentration in an aqueous solution at a constant concentration of glycine and its oligomers are determined. A comparative analysis of the thermodynamic characteristics of Gly, GlyGly, and GlyGlyGly transfer within the studied range of SDS concentrations is performed. The results are interpreted in terms of ion-ion, ion-polar, and hydrophobic interactions between SDS and molecules of glycine and its oligomers.

  12. Evolution of the corrosion process of AA 2024-T3 in an alkaline NaCl solution with sodium dodecylbenzenesulfonate and lanthanum chloride inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Biner; Wang, Yishan; Zuo, Yu, E-mail: zuoy@mail.buct.edu.cn

    2015-12-01

    Highlights: • Inhibition effect of LaCl{sub 3} and SDBS for AA 2024 in NaCl solution (pH 10) was studied. • At the beginning the active polarization behavior of the alloy changed to passivation. • The passive behavior gradually disappeared with time and pitting happened at S-phases. • The compounded inhibitors showed good inhibition but cannot totally inhibit pitting. • The adsorption of SDBS played the key role for inhibition to the corrosion process. - Abstract: The evolution of the corrosion process of AA 2024-T3 in 0.58 g L{sup −1} NaCl solution (pH 10) with sodium dodecylbenzenesulfonate (SDBS) and lanthanum chloride inhibitors was studied with electrochemical and surface analysis methods. With the addition of the compounded LaCl{sub 3} and SDBS inhibitors, in the early stage the polarization behavior of AA 2024-T3 changed from active corrosion to passivation, and both the general corrosion and pitting corrosion were inhibited. However, with the immersion time extended, the passive behavior gradually disappeared and pitting happened at the Cu-rich phases. After 24 h immersion, the compounded inhibitors still showed good inhibition for general corrosion, but the polarization curve again presented the characteristic similar to active polarization. The compounded inhibitors also inhibited the pitting corrosion to some extent. The acting mechanism of the inhibitors SDBS and La{sub 3}Cl on the corrosion process of AA 2024-T3 in the test solution was discussed.

  13. Effect of nitriding surface treatment on the corrosion resistance of dental nickel-titanium files in 5.25% sodium hypochlorite solution

    International Nuclear Information System (INIS)

    Liu, J.-F.; Lin, M.-C.; Hsu, M.-L.; Li, U.-M.; Lin, C.-P.; Tsai, W.-F.; Ai, C.-F.; Chen, L.-K.; Huang, H.-H.

    2009-01-01

    This study investigated the effect of nitriding surface treatment on the corrosion resistance of commercial dental alloy, in the form of helical nickel-titanium (Ni-Ti) files, when treated with 5.25% sodium hypochlorite (NaOCl) solution. The surface of dental helical Ni-Ti files was modified using nitriding treatment at 200 deg. C, 250 deg. C and 300 deg. C in an NH 3 -containing environment. The surface morphology and chemical composition of the Ni-Ti files were analyzed using scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS), respectively. The corrosion resistance of the Ni-Ti files when treated with a clinical solution of 5.25% NaOCl was evaluated using the linear polarization method and by potentiodynamic polarization curve measurement. The nitriding treatments at different temperatures created titanium nitride (TiN) on the surface of the helical Ni-Ti files. The Ni-Ti files nitrided at 200 deg. C and 250 deg. C showed higher polarization resistance and higher passive film breakdown potential together with a lower passive current than untreated files. The presence of TiN on dental Ni-Ti files significantly increased the corrosion resistance of the files in the presence of 5.25% NaOCl solution.

  14. THE EFFECT OF Fe-ENRICH PHASE ON THE PITTING CORROSION RESISTANCE OF Al ALLOY IN VARIOUS NEUTRAL SODIUM CHLORIDE SOLUTIONS

    Directory of Open Access Journals (Sweden)

    Gadang Priyotomo

    2014-10-01

    Full Text Available The pitting corrosion of 5052 alloy was investigated as function of chloride concentrations by using an electrochemical method, scanning electron microscope and energy dispersive X-Ray spectroscopy in neutral sodium chloride solutions at 293 K.  The pitting corrosion of pure Al was also investigated under the same experimental condition for the comparison. The pitting potential obtained for 5052 alloy and pure Al decreased with increasing chloride concentration.  The pitting potential of pure Al is higher than that of 5052 alloy where pitting resistance of pure Al is better than that 5052 alloy.  The linear equation implies that certain pitting potential becomes a relevant parameter for predicting certain chloride ion concentration.  The synergic role of chloride ion and a localized galvanic corrosion between aluminium metal and iron-containing constituent contribute the process of pitting for 5052 alloy.

  15. Extraction of lanthanides ions (III) from aqueous solution by sodium salt of the N(4-amino-benzoate)-propyl-silica gel

    International Nuclear Information System (INIS)

    Retamero, R.C.

    1991-01-01

    The silica gel 60 of specific superficial area 486 m 2 .g -1 was modified chemically with the ligand 4-amino benzoate of sodium in water-ethanol environment (l:L). The adsorptions of metallic ions were from water solutions at approximately 2 x 10 -3 M of chloride of Pr(III), Nd(III), Eu(III) and Ho(III). In these experiments we could see that the system gets the equilibrium of adsorption rapidly and that the pH of the environment has a great influence on the process of adsorption, being that the number of metal mols adsorpted in the matrix varied between 10,00 and 17,00 x 10 -5 mols. g -1 with a pH of approximately 5 for all the lanthanides, where the adsorption curves reach equilibrium. (author)

  16. Some features of the anodic dissolution of platinized titanium anodes and of oxygen evolution in the electrolysis of dilute sodium chloride solutions

    International Nuclear Information System (INIS)

    Mikhailova, L.A.; Khodkevich, S.D.; Yakimenko, L.M.; Ivanova, M.I.; Ogloblina, I.P.

    1988-01-01

    Radioactivity measurements and gas chromatography were used to study and compare features of anodic dissolution of platinum and platinum coatings from platinized titanium anodes, and oxygen evolution as functions of the electrolysis parameters of current density, temperature, and concentration in electrolytes with low sodium chloride content. Quantities representing the ratio of anodic platinum dissolution rates and oxygen evolution were calculated. The results showed that analogies exist between rates of platinum dissolution, and oxygen evolution but these ratios are not constant when the electrolysis parameters are varied within wide limits. A correlation was observed for dilute solutions and electrolysis temperatures enabling one to estimate the corrosion rates of platinized titanium anodes from the oxygen content of the electrolytic gas

  17. Fluidized-Bed Coating with Sodium Sulfate and PVA-TiO2, 2. Influence of Coating Solution Viscosity, Stickiness, pH, and Droplet Diameter on Agglomeration

    DEFF Research Database (Denmark)

    Hede, Peter Dybdahl; Bach, Poul; Jensen, Anker Degn

    2009-01-01

    In the first part of this study [Hede, P. D.; Bach, P.; Jensen, A. D. Ind. Eng. Chem. Res. 2009, 49, 1914], agglomeration regime maps were developed for two types of coatings: sodium sulfate and PVA-TiO2. It was observed here how the agglomeration tendency is always lower for the salt coating...... the PVA-TiO2 coating formulation and process to achieve a low tendency of agglomeration, similar to that of the salt coating process. The best results for the PVA-TiO2 solution are obtained by substituting the PVA-TiO2 in equal amounts with Neodol 23-6.5 and further reducing the pH value in the coating...

  18. Lightweight Heat Resistant Geopolymer-based Materials Synthesized from Red Mud and Rice Husk Ash Using Sodium Silicate Solution as Alkaline Activator

    Directory of Open Access Journals (Sweden)

    Hoc Thang Nguyen

    2017-01-01

    Full Text Available Geopolymer is an inorganic polymer composite with potentials to replace Ordinary Portland Cement (OPC-based materials in the future because of its lower energy consumption, minimal CO2 emissions and lower production cost as it utilizes industrial waste resources. Hence, geopolymerization and the process to produce geopolymers for various applications like building materials can be considered as green industry. Moreover, in our study, the raw materials we used are red mud and rice husk ash, which are are industrial and agricultural wastes that need to be managed to reduce their impact to the environment. The red mud and rice husk ash combined with sodium silicate (water glass solution were mixed to form geopolymer materials. Moreover, the geopolymer specimens were also tested for heat resistance at a temperature of 1000°C for 2 hours. Results suggest high heat resistance with an increase of compressive strength after exposed at high temperature.

  19. The application of sol-gel and gel-precipitation technology to the preparation of spheres of lithium aluminate

    International Nuclear Information System (INIS)

    Turner, C.W.; Clatworthy, B.C.

    1988-01-01

    A concept for preparing spheres of lithium aluminate by either a sol-gel or gel-precipitation process based on the precipitation of a lithium salt in the pores of an aluminum hydroxide gel has been tested and has proved to be not feasible. The addition of any of the following salts: lithium formate; lithium oxalate; or lithium carbonate to a solution of aluminum nitrate hydrolysed to a hydroxyl number greater than 2.85 caused the hydrolysed solution, or sol, to gel immediately. The addition of lithium formate to a dialysed sol caused it to flocculate at low pH and prevented the transformation from a sol to a gel from occurring at elevated pH. This behaviour was linked to the adsorption of the anions - formate, oxalate, or carbonate - onto the surface of the sol particles. Hydrolysis of solutions of aluminum nitrate together with either lithium formate, lithium oxalate, or lithium carbonate, such that the mole ratio of aluminum to lithium was 1:1, resulted in the formation of a crystalline precipitate containing both lithium and aluminum. The lithium to aluminum ratio of the precipitate was 0.44:1 when lithium was introduced as the carbonate. Spheres could be made by gel-precipitation if the viscosity of the feed solution was first increased to 200 cps by the addition of polyvinyl alcohol. However, the lithium not chemically bound in the precipitate diffused out of the spheres during gelation. Heating of the lithium-deficient spheres to 950 degrees C produced a mixture of lithium aluminate and the spinel phase, LiAl 5 O 8

  20. Initial stages of anodic oxidation of silver in sodium hydroxide solution studied by potential sweep voltammetry and ellipsometry

    NARCIS (Netherlands)

    Droog, J.M.M.; Alderliesten, P.T.; Bootsma, G.A.

    1979-01-01

    The first stages of the oxidation of polycrystalline silver electrodes in NaOH solutions were studied by potential sweep voltammetry and ellipsometry. Formation of bulk Ag2O was found to be preceded by dissolution of silver species and deposition of a surface oxide. The equilibrium oxide coverage

  1. Sodium fluxes in sweet pepper exposed to varying sodium concentrations

    NARCIS (Netherlands)

    Blom-Zandstra, M.; Vogelzang, S.A.; Veen, B.W.

    1998-01-01

    The sodium transport and distribution of sweet pepper (Capsicum annuum L.) under saline conditions were studied after transferring the plants to a sodium-free nutrient solution. Sodium stress up to 60 mM did not affect the growth of sweet pepper, as it appears able to counteract the unfavourable

  2. Investigation of the interaction of sodium nitrite with hydrogen peroxide in aqueous solutions by the chemiluminescence method

    Science.gov (United States)

    Starodubtseva, M. N.; Cherenkevich, S. N.; Semenkova, G. N.

    1999-05-01

    An investigation is made of the chemiluminescence (luminol-dependent and spontaneous) of aqueous solutions of NaNO2 and H2O2 in the pH range of 4.0 9.0. In the presence of luminol at pH>7 the initiator of luminescence is H2O2. At pHperoxynitrit acid in an activated state (HOONO*).

  3. Concentrated Aqueous Sodium Chloride Solution in Clays at Thermodynamic Conditions of Hydraulic Fracturing: Insight from Molecular Dynamics Simulations.

    Czech Academy of Sciences Publication Activity Database

    Svoboda, Martin; Lísal, Martin

    2018-01-01

    Roč. 148, č. 22 (2018), č. článku 222806. ISSN 0021-9606 R&D Projects: GA ČR GA17-25100S EU Projects: European Commission(XE) 640979 - ShaleXenvironmenT Institutional support: RVO:67985858 Keywords : aqueous NaCl solutions * hydrogen bond networks * molecular dynamics simulations Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 2.965, year: 2016

  4. Binding of sodium dodecyl sulfate with linear and branched polyethyleneimines in aqueous solution at different pH values.

    Science.gov (United States)

    Wang, Hao; Wang, Yilin; Yan, Haike; Zhang, Jin; Thomas, Robert K

    2006-02-14

    Isothermal titration microcalorimetry (ITC), conductivity, and turbidity measurements have been carried out to study the interaction of sodium dodecyl sulfate (SDS) with polyethyleneimines (PEI) including linear PEI and branched PEI at different pH values of 3, 7, and 10. In all cases, the polymers show a remarkable affinity toward SDS. At pH 3, the polymer PEI is a strong polycation, and the binding is dominated by electrostatic 1:1 charge neutralization with the anionic surfactant. At pH 7, the electrostatic attraction between SDS and PEI is weak, and the hydrophobic interaction becomes stronger. At the natural pH of 10, PEI is essentially nonionic and binds SDS in the form of polymer-bound surfactant aggregates. The charge neutralization concentration (C1) of SDS for the PEI-SDS complex can be derived from the curves of variation of the enthalpy, conductivity, and turbidity with SDS concentration. There is good agreement between the results from the three methods and all show a decrease with increasing pH. The total interaction enthalpies (deltaH(total)) of PEI with SDS are obtained from the observed enthalpy curves and the difference enthalpy (deltaH*) between the total enthalpy of branched PEI with SDS, and the total enthalpy of linear PEI with SDS can be derived from the obtained deltaH(total). The difference deltaH* increases dramatically as pH increases, which indicates that the interactions are different for linear PEI and branched PEI at high pH values. A schematic map of the different states of aggregation is presented.

  5. In situ Microscopic Observation of Sodium Deposition/Dissolution on Sodium Electrode

    OpenAIRE

    Yuhki Yui; Masahiko Hayashi; Jiro Nakamura

    2016-01-01

    Electrochemical sodium deposition/dissolution behaviors in propylene carbonate-based electrolyte solution were observed by means of in situ light microscopy. First, granular sodium was deposited at pits in a sodium electrode in the cathodic process. Then, the sodium particles grew linearly from the electrode surface, becoming needle-like in shape. In the subsequent anodic process, the sodium dissolved near the base of the needles on the sodium electrode and the so-called ?dead sodium? broke a...

  6. Similar influence of stabilized alkaline and neutral sodium hypochlorite solutions on the fracture resistance of root canal-treated bovine teeth.

    Science.gov (United States)

    Souza, Erick Miranda; Calixto, Amanda Martins; Lima, Camila Nara E; Pappen, Fernanda Geraldo; De-Deus, Gustavo

    2014-10-01

    Stabilizing sodium hypochlorite (NaOCl) at an alkaline pH is proposed to increase solution stability and tissue dissolution ability; however, a reduction on the flexural strength of dentin discs has been found to be a side effect. This study sought to determine whether a stabilized alkaline NaOCl reduces the fracture resistance of root canal-treated bovine teeth after root canal preparation compared with a neutral solution counterpart. The 4 anterior incisors were removed from 20 mandibular bovine jaws, and each 1 was randomly assigned to 1 of 4 groups (20 teeth each). Teeth were prepared with a sequence of 6 K-type files. The following experimental groups received a different irrigation regimen: G1: distilled water (negative control), G2: 5% NaOCl at a pH of 7.2, and G3: 5% NaOCl at a pH of 12.8; in the positive control group (G4), teeth remained untreated. The time of contact and volume of solution were carefully standardized. After bone and periodontal ligament simulation, teeth were subjected to a fracture resistance test. A significant difference was observed among the 4 groups tested (analysis of variance, P .05). No differences were observed between positive and negative control groups (Tukey test, P > .05). Stabilized alkaline and neutral NaOCl solutions similarly reduced the fracture resistance of root canal-treated bovine teeth by about 30%. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  7. A method for the separation of sodium and iron from plutonium and other impurities in concentrated plutonium solution and their subsequent measurement

    International Nuclear Information System (INIS)

    Mair, M.A.; Brown, M.L.

    1988-06-01

    Sodium and iron are separated from plutonium and other impurities by solvent extraction. Sodium is determined by flame photometry and iron by spectrophotometric measurement of the orthophenanthroline complex. (author)

  8. Influence of microstructure in corrosion behavior of an Inconel 600 commercial alloy in 0.1 M sodium thiosulfate solution

    International Nuclear Information System (INIS)

    Granados, J.; Rodriguez, F.J.; Arganis, C.

    1999-01-01

    The Inconel 600 is used in diverse components of BWR and PWR type reactors, where diverse cases of intergranular stress corrosion have been presented. It has been reported susceptibility to the corrosion of this alloy, in presence of thiosulfates, which come from the degradation of the ion exchange resins of water treatments that use the reactors. The objective of this work is to study the influence of metallurgical condition in the corrosion velocity of Inconel 600 commercial alloy, in a 0.1 M thiosulfates solution. (Author)

  9. The Effect of Nano-Aluminumpowder on the Characteristic of RDX based Aluminized Explosives Underwater Close-Filed Explosion

    Directory of Open Access Journals (Sweden)

    Junting Yin

    2017-01-01

    Full Text Available In order to investigate the effect of nano-aluminum powder on the characteristic of RDX based aluminized explosives underwater closed-filed explosions, the scanning photographs along the radial of the charges were gained by a high speed scanning camera. The photographs of two different aluminized explosives underwater explosion have been analyzed, the shock wave curves and expand curves of detonation products were obtained, furthermore the change rules of shock waves propagation velocity, shock front pressure and expansion of detonation products of two aluminized explosives were investigated, and also the parameters of two aluminized explosives were contrasted. The results show that the aluminized explosive which with nano-aluminum whose initial shock waves pressure propagation velocity, shock front pressure are smaller than the aluminized explosive without nano-aluminum and has lower decrease rate attenuation of energy.

  10. The cleanliness differences of root canal walls after irrigated with East Java propolis extract and sodium hypoclorite solutions

    Directory of Open Access Journals (Sweden)

    Tamara Yuanita

    2017-03-01

    (n=10. The specimens were prepared with ProTaper. During instrumentation, the root canals were irrigated with different solutions: Control Group irrigated with aquadest; Group 1 irrigated with 8% East Java propolis extract; Group 2 irrigated with 2.5% NaOCl and Group 3 irrigated with 5% NaOCl. The root canals were cut at apical third and SEM scores were tested by using Mann-Whitney test at the significance level of p=0.05 and Median Control test. Result: The results of Mann-Whitney Test, there were significant differences between control group with Group 1, 2 and 3 (p<0.05. Based on the Median Control test, the value of 8% East Java propolis extracts was 1,000, which was the best value compared to 2.5% NaOCl, 5% NaOCl and aquadest. Conclusion: It can be concluded that 8% East Java propolis extract is the most effective solution for cleaning root canal walls compared with 2.5% NaOCl and 5% NaOCl.

  11. Effects of structural and textural grain characteristics on leaching of sulphide minerals from a polymetallic concentrate by sodium nitrate and sulphuric acid solution

    Directory of Open Access Journals (Sweden)

    Sokić Miroslav D.

    2017-01-01

    Full Text Available In this paper, the influence of structural and textural characteristics of sulfide minerals on their leaching from a polymetallic concentrate by sulfuric acid and sodium nitrate solution is presented. The starting material was Pb–Zn–Cu sulphide polymetallic concentrate enriched during the flotation of a polymetallic ore in the "Rudnik" flotation plant (Rudnik – Serbia. Leaching experiments were carried out in a closed glass reactor, which provides stable hermetic conditions and allows heating at constant temperature. Chemical, XRD, qualitative and quantitative microscopic and SEM/EDX analyses were used to characterizes samples of the polymetallic concentrate and leach residue. It was determined that chalcopyrite, sphalerite, galena, pyrrhotite and quartz were present in the polymetallic concentrate. The content of sulphide minerals was 69.5%, of which 60.9% occurred as liberated grains: 88.3% of chalcopyrite, 59.3% of sphalerite, 25.1% of galena and 51.6% of pirrhotite. The rest of chalcopyrite, sphalerite, galena and pirrhotite grains were in the forms of inclusions, impregnations, and simple and complex intergrowths. During the leaching process by sodium nitrate and sulphuric acid solution, it was shown previously that the leaching rate of sulphide minerals decreased with time while a part of the sulphide minerals remained in the leach residue. After leaching at 80°C for 120 min, the yields were 69.8, 82.7 and 67.1% for Cu, Zn and Fe, respectively. Lead, in the form of insoluble anglesite, remained in the leach residue. In addition to the anglesite, unleached sulfide minerals and quartz, elemental sulfur was found in the solid residue. The content of sulphide minerals was 35% of which 33.7% minerals occur independently. In specific, 54.7% of chalcopyrite, 31.9% of sphalerite, 8.2% of galena and 37.6% of pyrrhotite appear as separate grains with highly corroded surfaces. Therefore, the structural assembly of sulphide grains in the

  12. Inactivation of Escherichia coli O157:H7 and Salmonella during washing of contaminated gloves in levulinic acid and sodium dodecyl sulfate solutions.

    Science.gov (United States)

    Erickson, Marilyn C; Liao, Jye-Yin; Habteselassie, Mussie Y; Cannon, Jennifer L

    2018-08-01

    Field workers often wear gloves harvesting ready-to-eat produce; however, fields are not sterile environments and gloves may become contaminated numerous times during a working shift. This study explored the potential for inactivation of Escherichia coli O157:H7 and Salmonella when contaminated gloves were washed in levulinic acid (LV) and sodium dodecyl sulfate (SDS) solutions. Washing nitrile gloves with increasing concentrations of LV above 1.0% led to a decreased prevalence of glove contamination by Salmonella (P = 0.0000). A higher level of prevalence occurred for solid agar-cultured pathogens than liquid broth-cultured pathogens after nitrile gloves were washed in LV/SDS (P = 0.0000). Pathogens residing on latex gloves were more likely to be completely inactivated by washing in 0.5% LV/0.1% SDS solutions than nitrile or Canners gloves that exhibited inconsistent responses dependent on the pathogen strain. However, drying after washing nitrile gloves in 0.5% LV/0.1% SDS led to additional pathogen inactivation (P = 0.0394). Pathogen transfer from gloves to produce was implied as the pathogen prevalence on cantaloupe rind handled by LV/SDS-washed gloves was not statistically different from the prevalence on gloves (P = 0.7141). Hence, the risk of produce contamination may still exist but would be reduced by washing gloves in LV/SDS. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Thermochemistry of the Dissolution of Dipeptides Containing DL-α-Alanine in Aqueous Solutions of Sodium Dodecyl Sulfate at 298.15 K

    Science.gov (United States)

    Smirnov, V. I.; Badelin, V. G.

    2018-05-01

    Enthalpies of the dissolution of DL-α-alanylglycine (AlaGly), DL-α-alanyl-DL-α-alanine (AlaAla), DL-α-alanyl-DL-α-valine (AlaVal), and DL-α-alanyl-DL-norleucine (AlaNln) in an aqueous solution of sodium dodecyl sulfate (SDS) at SDS concentration of m = 0-0.07 mol kg-1 and temperature T = 298.15 K are measured via calorimetry. The standard values of the enthalpy of dissolution (Δsol H m ) and the transfer of dipeptides (Δtr H m ) from water to aqueous SDS solutions are calculated using the experimental data. The dependences of Δsol H m and Δtr H m the SDS concentration at a constant concentration of dipeptide are established. Thermochemical characteristics of the transfer of AlaGly, AlaAla, AlaVal, and AlaNln in the investigated range of SDS concentrations are compared. The results are interpreted by considering ion-ion, ion-polar, and hydrophobic-hydrophobic interactions between SDS and dipeptide molecules.

  14. Micellization, interaction and thermodynamic study of butylated hydroxyanisole (synthetic antioxidant and sodium dodecyl sulfate in aqueous-ethanol solution at 25, 30 and 35 °C

    Directory of Open Access Journals (Sweden)

    Varun Bhardwaj

    2016-09-01

    Full Text Available Surfactants are found to enhance the diffusion significantly depending on hydrophobic/hydrophilic group lengths and the structure of the surfactant molecule. Aggregation properties of sodium dodecyl sulfate (SDS in the presence of butylated hydroxyanisole (synthetic antioxidant, at a range of temperatures (25, 30 and 35 °C have been measured by the conductometric study in aqueous-ethanolic composite solution. The experimental data of aqueous-ethanolic solutions as a function of SDS concentration ranging from 1 to 14 mM dm−3 show the presence of inflexion points indicating micellization and interaction mechanisms. Effect of temperature was also observed in increasing the CMC (Critical Micelle Concentration in the narrow composition. From the CMC values as a function of temperature, various thermodynamic parameters have been evaluated viz: (a the standard enthalpy change (ΔHm°, (b standard entropy change (ΔSm°, and (c standard Gibbs energy change (ΔGm°. The results showed that the presence of alcohol, as well as the composition of water + ethanol may have effect on thermodynamic parameters. The variation in these parameters with the concentration of surfactant or with the change in temperature suggests the manifestation of hydrophobic interactions in the studied system.

  15. Influence of organic solvent treatment on elasticoluminescent property of europium-doped strontium aluminates

    International Nuclear Information System (INIS)

    Fujio, Yuki; Xu, Chao-Nan; Terasaki, Nao; Ueno, Naohiro

    2014-01-01

    The influence of an organic solvent treatment on elasticoluminescent (ELS) characteristics of mechanoluminescent (ML) sensor using the composite film consisting of an ELS material and epoxy resin was investigated. We used strontium aluminate doped with a small amount of europium (SrAl 2 O 4 :Eu, SAOE) as an ELS material in this study. After evaluating the ELS characteristics of the fabricated ML sensors using SAOE treated with/without various organic solvents, SAOE treated with methanol and ethanol showed lower ELS intensities than that of untreated SAOE. In contrast, the ELS response curves against strain for the ML sensors using SAOE treated with acetone and toluene, overlapped with that of untreated SAOE. From the characterization of SAOE treated with alcohols, such as methanol and ethanol, we can hypothesize that poor ELS characteristics is due to the degradation of the SAOE grain surfaces by the hydrolyze reaction of SAOE with hydroxyl group of alcohol. Thus, on the basis of the obtained results, we can conclude that the selection of organic solvent used in the preparation of SAOE film is of considerable importance in the development of ML sensor with a highly-reliable ELS characteristic. -- Highlights: • Influence of organic solution treatment on the sensing characteristics of a mechanoluminescent (ML) sensor using SrAl 2 O 4 :Eu has been investigated. • An alcohol treatment of SAOE powder has considerable effect on its ML characteristic. • There is almost no influence of acetone and toluene treatments on ML characteristics

  16. Modeling and simulation of pit chemistry of 304 austenitic stainless steel under applied stress in sodium chloride solution

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Yuhui, E-mail: yhhuang@ecust.edu.cn [Key Laboratory of Pressure Systems and Safety, MOE, School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237 (China); Tu, Shan-Tung; Xuan, Fu-Zhen [Key Laboratory of Pressure Systems and Safety, MOE, School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237 (China)

    2013-04-15

    Highlights: ► A corrosion model was developed to simulate a stressed metal surface with a pit. ► The stress state in the pit bottom was coupled with the local corrosion environment. ► An analytical expression was established for current density of deformed pit surface. ► Local deformation had a strong effect on potential and species concentration in pits. -- Abstract: A mathematical model for simulating the active dissolution of a pit on stressed metal surface had been developed. Based on active dissolution mechanism, dissolution current density on the pit surface was assumed and extended through accounting for the thermal activation energy and the multiaxial stress state in pit bottom. The influence of applied tensile stress, pit radius and temperature was addressed. The distribution of solution potential and species concentration was predicted for different applied tensile stresses based on finite element calculations.

  17. Friedel's salt profiles from thermogravimetric analysis and thermodynamic modelling of Portland cement-based mortars exposed to sodium chloride solution

    DEFF Research Database (Denmark)

    Shi, Zhenguo; Geiker, Mette Rica; Lothenbach, Barbara

    2017-01-01

    indicates that only a minor part of the chloride ions is bound in Friedel's in the studied Portland cement (P) and limestone blended (L) cement. The chloride binding capacity with respect to the formation of Friedel's salt by consumption of monocarbonate is reached for the P and L mortars, where only...... a fraction of about 20% of the amount of C3A is found to contribute to formation of Friedel's salt. Higher amounts of Friedel's salt are formed in the metakaolin containing mortars. However, the limited chloride ingress depths prevent quantification of the potential full chloride binding capacity of Friedel......Thermogravimetric analysis (TGA), powder X-ray diffraction (XRD) and thermodynamic modelling have been used to obtain Friedel's salt profiles for saturated mortar cylinders exposed to a 2.8 M NaCl solution. Comparison of the measured Friedel's salt profiles with the total chloride profiles...

  18. Study on Corrosion of Macroporous Silicon in Sodium Hydroxide Solution by Electrochemical Methods and Scanning Electron Microscopy

    Directory of Open Access Journals (Sweden)

    Chuan Lai

    2015-01-01

    Full Text Available The fabricated macroporous silicon with a porosity of 26.33% corrosion in NaOH solution was systemically investigated by open circuit potential measurements, linear polarization measurements, potentiodynamic polarization measurements, and scanning electron microscopy, respectively. Results show that the potential open circuit and linear polarization resistance decreases with the NaOH concentration increasing. The corrosion potential shifts significantly to more negative potentials and corrosion current density increases with NaOH concentration increasing. Adding ethanol to 1.0 M NaOH can lead to the linear polarization resistance decrease, corrosion potentials shift in the positive direction, and corrosion current density increase. In addition, the scanning electron microscopy images demonstrate that the macroporous silicon samples are seriously damaged by 1.0 M NaOH and 1.0 M NaOH/EtOH (30%.

  19. Neptunium separation in trace levels from uranium solutions by extraction chromatography

    International Nuclear Information System (INIS)

    Cotrim, M.B.; Matsuda, H.T.

    1994-01-01

    Neptunium and uranium behavior in extraction chromatograph system, aiming the separation of micro quantities of neptunium from uranyl solutions is described. Tri-n-octylamine (TOA), Tri-n-butylphosphate (TBP) as stationary phase, alumine, Voltalef UF-300 as support material were verified. The impregnation conditions as well as the best stationary phase/support material ratio were established. TBP/alumine, TBP/Voltalef and TOA/alumine system were selected to uranium and neptunium separation studies. (author) . 12 refs., 03 tabs., 03 figs

  20. Fabrication of calcite blocks from gypsum blocks by compositional transformation based on dissolution-precipitation reactions in sodium carbonate solution.

    Science.gov (United States)

    Ishikawa, Kunio; Kawachi, Giichiro; Tsuru, Kanji; Yoshimoto, Ayami

    2017-03-01

    Calcium carbonate (CaCO 3 ) has been used as a bone substitute, and is a precursor for carbonate apatite, which is also a promising bone substitute. However, limited studies have been reported on the fabrication of artificial calcite blocks. In the present study, cylindrical calcite blocks (ϕ6×3mm) were fabricated by compositional transformation based on dissolution-precipitation reactions using different calcium sulfate blocks as a precursor. In the dissolution-precipitation reactions, both CaSO 4 ·2H 2 O and CaSO 4 transformed into calcite, a polymorph of CaCO 3 , while maintaining their macroscopic structure when immersed in 1mol/L Na 2 CO 3 solution at 80°C for 1week. The diametral tensile strengths of the calcite blocks formed using CaSO 4 ·2H 2 O and CaSO 4 were 1.0±0.3 and 2.3±0.7MPa, respectively. The fabrication of calcite blocks using CaSO 4 ·2H 2 O and CaSO 4 proposed in this investigation may be a useful method to produce calcite blocks because of the self-setting ability and high temperature stability of gypsum precursors. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. The anodic dissolution of SIMFUEL (UO{sub 2}) in slightly alkaline sodium carbonate/bicarbonate solutions

    Energy Technology Data Exchange (ETDEWEB)

    Keech, P.G.; Goldik, J.S.; Qin, Z. [Department of Chemistry, University of Western Ontario, 1151 Richmond St, London ON, N6A 5B7 (Canada); Shoesmith, D.W., E-mail: dwshoesm@uwo.ca [Department of Chemistry, University of Western Ontario, 1151 Richmond St, London ON, N6A 5B7 (Canada)

    2011-09-30

    The corrosion of nuclear fuel under waste disposal conditions is likely to be influenced by the bicarbonate/carbonate content of the groundwater since it increases the solubility of the U{sup VI} corrosion product, [UO{sub 2}]{sup 2+}. As one of the half reactions involved in the corrosion process, the anodic dissolution of SIMFUEL (UO{sub 2}) has been studied in bicarbonate/carbonate solutions (pH 9.8) using voltammetric and potentiostatic techniques and electrochemical impedance spectroscopy. The reaction proceeds by two consecutive one electron transfer reactions (U{sup IV} {yields} U{sup V} {yields} U{sup VI}). At low potentials ({<=}250 mV (vs. SCE) the rate of the first electron transfer reaction is rate determining irrespective of the total carbonate concentration. At potentials >250 mV (vs. SCE) the formation of a U{sup VI}O{sub 2}CO{sub 3} surface layer begins to inhibit the dissolution rate and the current becomes independent of potential indicating rate control by the chemical dissolution of this layer.

  2. Effect of carbon dioxide on the rate of iodine vapor absorption by aqueous solution of sodium hydroxide

    International Nuclear Information System (INIS)

    Eguchi, Wataru; Adachi, Motonari; Miyake, Yoshikazu

    1978-01-01

    There is always carbon dioxide in the atmosphere as an impurity. Since this is an acid gas similar to iodine, each absorption rate seems to be affected by the other due to the coexistence of these two. Experiments have been conducted to clarify the absorption rate and absorption mechanism of iodine in the simultaneous absorption of iodine and carbon dioxide. Carbon dioxide coexisting with gas phases as an impurity decreases the absorption rate of iodine in the removal by washing with water of iodine mixed in the air. The first cause of this is that the diffusion coefficient of iodine in gas phase decreases with the carbon dioxide content in the gas phase. The second cause is that coexistent carbon dioxide is an acid gas, dissociates by dissolving into the absorbing solution, increases hydrogen ion concentration together with the formation of negative ions of bicarbonate and carbonate, and reduces hydroxyl ion concentration as a result. It is more important that existence of iodine has a catalytic effect to the rate of basic catalytic hydrolysis of carbon dioxide simultaneously dissolved in water phase, and accelerates this reaction rate. The mechanism of catalytic effect of iodine for the hydrolysis of carbon dioxide can not be clarified in detail only by this experiment, but the simultaneous absorption rate of iodine and carbon dioxide can be explained satisfactorily. (Wakatsuki, Y

  3. Ignition threshold of aluminized HMX-based PBXs

    Science.gov (United States)

    Miller, Christopher; Zhou, Min

    2017-06-01

    We report the results of micromechanical simulations of the ignition of aluminized HMX-based PBX under loading due to impact by thin flyers. The conditions analyzed concern loading pulses on the order of 20 nanoseconds to 0.8 microseconds in duration and impact piston velocities on the order of 300-1000 ms-1. The samples consist of a stochastically similar bimodal distribution of HMX grains, an Estane binder, and 50 μm aluminum particles. The computational model accounts for constituent elasto-vicoplasticity, viscoelasticity, bulk compressibility, fracture, interfacial debonding, fracture, internal contact, bulk and frictional heating, and heat conduction. The analysis focuses on the development of hotspots under different material settings and loading conditions. In particular, the ignition threshold in the form of the James relation and the corresponding ignition probability are calculated for the PBXs containing 0%, 6%, 10%, and 18% aluminum by volume. It is found that the addition of aluminum increases the ignition threshold, causing the materials to be less sensitive. Dissipation and heating mechanism changes responsible for this trend are delineated. Support by DOE NNSA SSGF is gratefully acknowledged.

  4. Luminescent characteristics of praseodymium-doped zinc aluminate powders

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez-Perez, C.D.; Garcia-Hipolito, M.; Alvarez-Fregoso, O. [Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, Coyoacan, DF (Mexico); Alvarez-Perez, M.A. [Facultad de Odontologia, Universidad Nacional Autonoma de Mexico, Coyoacan, DF (Mexico); Ramos-Brito, F. [Laboratorio de Materiales Optoelectronicos, DIDe, Centro de Ciencias de Sinaloa, Av. De las Americas No. 2771 Nte. Col. Villa Universidad, Culiacan, Sinaloa (Mexico); Falcony, C. [Centro de Investigaciones y Estudios Avanzados del IPN, Departamento de Fisica, Mexico, DF (Mexico)

    2010-02-15

    In this research, we report the cathodoluminescence (CL) and preliminary photoluminescence (PL) properties of praseodymium-doped zinc aluminate powders. ZnAl{sub 2}O{sub 4}:Pr powders were synthesized by a very simple chemical process. X-ray diffraction spectra indicated a cubic spinel crystalline structure with an average crystallite size of 15 nm. CL properties of the powders were studied as a function of the praseodymium concentration and electron-accelerating potential. In this case, all the cathodoluminescent emission spectra showed main peaks located at 494, 535, 611, 646, and 733 nm, which were associated to the electronic transitions {sup 3}P{sub 0}{yields}{sup 3}H{sub 4}, {sup 3}P{sub 0}{yields}{sup 3}H{sub 5}, {sup 3}P{sub 0}{yields}{sup 3}H{sub 6}, {sup 3}P{sub 0}{yields}{sup 3}F{sub 2}, and {sup 3}P{sub 0}{yields}{sup 3}F{sub 4} of the Pr{sup 3+} ions, respectively. A quenching of the CL, with increasing doping concentration, was observed. Also, an increment on cathodoluminescent emission intensity was observed as the accelerating voltage increased. The PL emission spectrum showed similar characteristics to those of the CL spectra. The chemical composition of the powders, as determined by energy dispersive spectroscopy, is also reported. In addition, the surface morphology characteristics of the powders are shown. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  5. Synthesis and optical property of zinc aluminate spinel cryogels

    Directory of Open Access Journals (Sweden)

    Lifen Su

    2016-06-01

    Full Text Available Zinc aluminate spinel cryogels with various molar ratio of Al/Zn are synthesized by sol–gel technology followed by vacuum freeze drying. The structures and optical properties are both found to be affected by the molar ratios of Al/Zn and annealed temperatures. The peaks of zinc oxide (ZnO and zinc dialuminum oxide (ZnAl2O4 are both obtained for the samples with more Zn content annealed at 750 °C or upward. The composites have a large surface area (137 m2/g with mesoporous structure after annealing at 750 °C. The SEM images reveal that the ZnAl2O4 crystals formed a multilayer structure with redundant ZnO particles which deposited on it. Furthermore, the maximum infrared reflectance is about 80% with an improvement of 35% in the infrared region after annealing at 950 °C compared with that of 450 °C, which indicates that these porous cryogels have a potential application as thermal insulating materials at a high temperature.

  6. Development of a Blue Emitting Calcium-Aluminate Phosphor.

    Directory of Open Access Journals (Sweden)

    Doory Kim

    Full Text Available We report methodological advances that enhance the phosphorescence efficiency of a blue-emitting calcium aluminate phosphor (CaAl2O4: Eu2+, Nd3+. The investigation of long-persistence blue-emitting phosphors is highly desirable due to their promising applications, such as white LEDs; however, the development of highly efficient blue-emitting phosphors is still challenging. Here, we have quantitatively characterized the phosphorescence properties of the blue-emitting phosphor CaAl2O4:Eu2+, Nd3+ with various compositions and directly related these properties to the quality of its luminescence. We optimized the composition of the activator Eu2+ and the co-activator Nd3+, the doping conditions with alkaline earth metals, alkali metals, and Si to create crystallographic distortions and, finally, the flux conditions to find the best parameters for bright and persistent blue-emitting phosphors. Our research has identified several doping compositions with good to excellent performance, with which we have demonstrated bright and persistent phosphors with afterglow characteristics superior to those of conventional phosphors.

  7. Synthesis optimization of calcium aluminate cement phases for biomedical applications

    International Nuclear Information System (INIS)

    Andrade, T.L.; Santos, G.L.; Oliveira, I.R.; Pandolfelli, V.C.

    2011-01-01

    Calcium aluminate cement (CAC) has been studied as a potential material for applications in the areas of health such as, endodontics and bone reconstruction. These studies have been based on commercial products consisting of a mixture of phases. Improvements can be attained by investigating the synthesis routes of CAC aiming the proper balance between the phases and the control of impurities that may impair its performance for biomedical applications. Thus, the aim of this work was to study the CAC synthesis routes in the Al 2 O 3 -CaCO 3 and Al 2 O 3 -CaO systems, as well as the phase characterization attained by means of X ray analysis. The Al 2 O 3 -CaO route enabled the production of the target phases (CA, CA 2 , C 3 A and C 12 A 7 ) with a higher purity compared to the Al2O3-CaCO3 one. As a result the particular properties of these phases can be evaluated to define a more suitable composition that results in better properties for an endodontic cement and other applications. (author)

  8. Efficacy and Safety of Sodium Picosulfate/Magnesium Citrate for Bowel Preparation in a Physically Disabled Outpatient Population: A Randomized, Endoscopist-Blinded Comparison With Ascorbic Acid-Enriched Polyethylene Glycol Solution Plus Bisacodyl (The PICO-MOVI Study).

    Science.gov (United States)

    Mathus-Vliegen, Elisabeth M H; van der Vliet, Karin; Wignand-van der Storm, Inge J; Stadwijk, John S

    2018-02-01

    Because of its volume, adequate bowel preparation remains problematic in physically unfit patients. This study aimed to compare a small-volume sodium picosulfate/magnesium citrate preparation with a 2-L ascorbic acid-enriched polyethylene glycol solution plus bisacodyl. This study has a noninferiority design, assuming that ascorbic acid-enriched polyethylene glycol solution plus bisacodyl is 70% efficacious in achieving an Ottawa score ≤7 and accepting a difference in success rate of ascorbic acid-enriched polyethylene glycol solution plus bisacodyl according to a split-dose regimen. Patients in the sodium picosulfate/magnesium citrate group received advice on the recommended 4-L fluid intake. Patients in the ascorbic acid-enriched polyethylene glycol solution plus bisacodyl group received 2 bisacodyl tablets 2 days before and advice on the additionally recommended 2-L fluid intake. To assess bowel-cleansing adequacy, the Ottawa, Aronchick, and Boston scores were used. Colonoscopy quality measures were obtained. Safety was assessed for a 30-day follow-up period. Overall, 341 patients (169 men, mean age 57.0 years; BMI 26.2 kg/m) were included. Comorbidities were present in 76.2% of patients, and 75.4% of patients used medication. An adequate Ottawa score was obtained in 81.4% and 75.8% of patients receiving ascorbic acid-enriched polyethylene glycol solution plus bisacodyl and sodium picosulfate/magnesium citrate (difference of 5.6% (95% CI, -3.5 to -14.6; p = 0.023)), showing noninferiority of the sodium picosulfate/magnesium citrate therapy. Ottawa segmental scores were lower for sodium picosulfate/magnesium citrate in the right and transverse colon. In both groups, successful ileocecal intubation was achieved in 95%. No medication-related adverse events were reported. These results in a physically disabled ambulant population cannot be extrapolated to immobile, hospitalized patients. Sodium picosulfate/magnesium citrate proved to be noninferior to ascorbic

  9. 21 CFR 522.460 - Cloprostenol sodium.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Cloprostenol sodium. 522.460 Section 522.460 Food... Cloprostenol sodium. (a)(1) Specifications. Each milliliter of the aqueous solution contains 263 micrograms of cloprostenol sodium (equivalent to 250 micrograms of cloprostenol) in a sodium citrate, anhydrous citric acid...

  10. Corrosion Study of Super Ferritic Stainless Steel UNS S44660 (26Cr-3Ni-3Mo) and Several Other Stainless Steel Grades (UNS S31603, S32101, and S32205) in Caustic Solution Containing Sodium Sulfide

    Science.gov (United States)

    Chasse, Kevin R.; Singh, Preet M.

    2013-11-01

    Electrochemical techniques, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) were used in this study to show how the corrosion mechanism of several commercial grades of stainless steel in hot caustic solution is strongly influenced by the presence of sodium sulfide. Experimental results from super ferritic stainless steel UNS S44660 (26Cr-3Ni-3Mo) were compared to austenitic stainless steel UNS S31603, lean duplex stainless steel (DSS) UNS S32101, and standard DSS UNS S32205 in caustic solution, with and without sodium sulfide, at 443 K (170 °C). Weight loss measurements indicated that corrosion rates of UNS44660 were much lower than the other grades of stainless steel in the presence of the sodium sulfide. Potentiodynamic polarization and linear polarization resistance measurements showed that the electrochemical behavior was altered by the adhesion of sulfur species, which reduced the polarization resistances and increased the anodic current densities. SEM and XPS results imply that the surface films that formed in caustic solution containing sodium sulfide were defective due to the adsorption of sulfide, which destabilized the passive film and led to the formation of insoluble metal sulfide compounds.

  11. Rapid discrimination of Gram-positive and Gram-negative bacteria in liquid samples by using NaOH-sodium dodecyl sulfate solution and flow cytometry.

    Directory of Open Access Journals (Sweden)

    Atsushi Wada

    Full Text Available BACKGROUND: For precise diagnosis of urinary tract infections (UTI, and selection of the appropriate prescriptions for their treatment, we explored a simple and rapid method of discriminating gram-positive and gram-negative bacteria in liquid samples. METHODOLOGY/PRINCIPAL FINDINGS: We employed the NaOH-sodium dodecyl sulfate (SDS solution conventionally used for plasmid extraction from Escherichia coli and the automated urine particle analyzer UF-1000i (Sysmex Corporation for our novel method. The NaOH-SDS solution was used to determine differences in the cell wall structures between gram-positive and gram-negative bacteria, since the tolerance to such chemicals reflects the thickness and structural differences of bacterial cell walls. The UF-1000i instrument was used as a quantitative bacterial counter. We found that gram-negative bacteria, including E. coli, in liquid culture could easily be lysed by direct addition of equal volumes of NaOH-SDS solution. In contrast, Enterococcus faecalis, which is a gram-positive bacterium, could not be completely lysed by the solution. We then optimized the reaction time of the NaOH-SDS treatment at room temperature by using 3 gram-positive and 4 gram-negative bacterial strains and determined that the optimum reaction time was 5 min. Finally, in order to evaluate the generalizability of this method, we treated 8 gram-positive strains and 8 gram-negative strains, or 4 gram-positive and 4 gram-negative strains incubated in voluntary urine from healthy volunteers in the same way and demonstrated that all the gram-positive bacteria were discriminated quantitatively from gram negative bacteria using this method. CONCLUSIONS/SIGNIFICANCE: Using our new method, we could easily discriminate gram-positive and gram-negative bacteria in liquid culture media within 10 min. This simple and rapid method may be useful for determining the treatment course of patients with UTIs, especially for those without a prior history

  12. Corrosion resistance of AA6063-Type Al-Mg-Si alloy by silicon carbide in sodium chloride solution for marine application

    Science.gov (United States)

    Fayomi, Ojo Sunday Isaac; Abdulwahab, Malik; Popoola, Abimbola Patricia Idowu; Asuke, Ferdinand

    2015-12-01

    The present work focused on corrosion inhibition of AA6063 type (Al-Mg-Si) alloy in sodium chloride (NaCl) solution with a silicon carbide inhibitor, using the potentiodynamic electrochemical method. The aluminium alloy surface morphology was examined, in the as-received and as-corroded in the un-inhibited state, with scanning electron microscopy equipped with energy dispersive spectroscopy (SEM-EDS). The results obtained via linear polarization indicated a high corrosion potential for the unprotected as-received alloy. Equally, inhibition efficiency as high as 98.82% at 10.0 g/v silicon carbide addition was obtained with increased polarization resistance ( R p), while the current density reduced significantly for inhibited samples compared to the un-inhibited aluminium alloy. The adsorption mechanism of the inhibitor aluminium alloy follows the Langmuir adsorption isotherm. This shows that the corrosion rate of aluminium alloy with silicon carbide in NaCl environment decreased significantly with addition of the inhibitor.

  13. A Randomized Prospective Study of Bowel Preparation for Colonoscopy with Low-Dose Sodium Phosphate Tablets versus Polyethylene Glycol Electrolyte Solution

    Directory of Open Access Journals (Sweden)

    Erina Kumagai

    2014-01-01

    Full Text Available Optimal bowel preparation is essential for the safety and outcome of colonoscopy. A solution containing polyethylene glycol (PEG is often used as a bowel cleansing agent, but some patients are intolerant of PEG, and this may lead to discontinuation of colonoscopy. Sodium phosphates (NaP tablets are designed to improve patient acceptance and compliance. The objective of this study was to compare bowel preparation efficiency and patient acceptance of a 30 NaP tablet preparation (L-NaP and a 2 L PEG preparation. Patients were randomized into either the L-NaP or PEG group. The primary endpoint was the efficiency of colon cleansing as assessed by a validated four-point scale according to the Aronchick scale by endoscopists and was verified by blinded investigators. The secondary endpoints were patients’ tolerability and acceptance. Colon-cleansing efficiency was not significantly different between the two preparations. However, patients’ overall judgment was significantly in favor of L-NaP, reflecting better acceptance of L-NaP than PEG. Additionally, more patients favored L-NaP over PEG in a hypothetical future occasion requiring colonoscopy.

  14. Batch adsorption and desorption studies on the removal of lead (II) from aqueous solution using nanochitosan/sodium alginate/microcrystalline cellulose beads.

    Science.gov (United States)

    Vijayalakshmi, K; Devi, B Mahalakshmi; Latha, Srinivasan; Gomathi, Thandapani; Sudha, P N; Venkatesan, Jayachandran; Anil, Sukumaran

    2017-11-01

    The feasibility of adsorption and desorption behavior of nanochitosan(NCS)/sodium alginate(SA)/microcrystalline cellulose (MC) bead prepared in 2:8:1 ratio for Pb(II) removal has been investigated through batch studies. The proof of adsorption of Pb(II) ions onto NCS/SA/MC beads was identified from FT-IR and EDX-SEM Studies. Studies of the effect of pH, adsorbent dose, metal ion concentration and temperature reveals that the optimum conditions for adsorption was found to be pH:6; adsorbent dose:4g; initial metal concentration: 62.5mg/L and temperature:50°C. Various equilibrium adsorption isotherm models namely Langmuir, Freundlich, Temkin and D-R applied for the analysis of isotherm data indicate that the Freundlich adsorption isotherm model was found to be followed. On the basis of kinetic studies, specific rate constants involved in the processes were calculated and the observed result shows that the pseudo second order kinetics was found to be a better fit. The desorption studies reveals that the recovery of Pb(II) from NCS/SA/MC bead was found to be effective by using 0.1M HCl solution. From the results it was evident that the NCS/SA/MC bead showed better Pb(II) uptake performance and regeneration for further use and hence it was found to be an efficient biosorbent for treating industrial effluent. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Sodium Borohydride Reduction of Aqueous Silver-Iron-Nickel Solutions: a Chemical Route to Synthesis of Low Thermal Expansion-High Conductivity Ag-Invar Alloys

    Science.gov (United States)

    Sterling, E. A.; Stolk, J.; Hafford, L.; Gross, M.

    2009-07-01

    Thermal management is a critical concern in the design and performance of electronics systems. If heat extraction and thermal expansion are not properly addressed, the thermal mismatch among dissimilar materials may give rise to high thermal stresses or interfacial shear strains, and ultimately to premature system failure. In this article, we present a chemical synthesis process that yields Ag-Invar (64Fe-36Ni) alloys with a range of attractive properties for thermal management applications. Sodium borohydride reduction of an aqueous Ag-Fe-Ni metal salt solution produces nanocrystalline powders, and conventional powder processing converts this powder to fine-grained alloys. The samples are characterized by X-ray diffraction (XRD), scanning electron microscopy, thermomechanical analysis, and electrical conductivity measurements; thermal conductivity is estimated using the Wiedemann-Franz law. Sintering of Ag-Fe-Ni powders leads to the formation of two-phase silver-Invar alloys with low coefficients of thermal expansion (CTEs) and relatively high electrical conductivities. A sample of 50Ag-50Invar exhibits a CTE of 8.76 μm/(m· °C) and an estimated thermal conductivity of 236 W/(m·K). The Ag-Invar alloys offer thermodynamic stability and tailorable properties, and they may help address the need for improved packaging materials.

  16. Effect of Dynamic Immersion in Sodium Hypochlorite and EDTA Solutions on Cyclic Fatigue Resistance of WaveOne and WaveOne Gold Reciprocating Nickel-titanium Files.

    Science.gov (United States)

    Uslu, Gülşah; Özyürek, Taha; Yılmaz, Koray; Plotino, Gianluca

    2018-01-12

    The purpose of this study was to evaluate the effect of sodium hypochlorite (NaOCl) and EDTA solutions on the cyclic fatigue resistance of WaveOne (WO) and WaveOne Gold (WOG) nickel-titanium reciprocating files. A hundred WO (25/.08), and 100 WOG (25/.07) were randomly divided into 5 groups: group 1, no immersion; group 2, immersion in 5.25% NaOCl at 37°C ± 1°C for 5 minutes; group 3, immersion in 5.25% NaOCl at 37°C ± 1°C for 10 minutes; group 4, immersion in 17% EDTA at 37°C ± 1°C for 5 minutes; and group 5, immersion in 17 % EDTA at 37°C ± 1°C for 10 minutes. Then, the instruments were reciprocated in an artificial canal until fracture occurred, and the time to fracture was recorded. The data were statistically analyzed using 1-way analysis of variance and the Student t test via SPSS 21.0 software (IBM Corp, Armonk, NY) with the significance level set at P  .05). Among the groups, there was no significant difference in the fracture lengths (P > .05). Within the limitations of the present study, it was determined that NaOCl and EDTA solutions did not have any effect on the cyclic fatigue resistance of WO and WOG files. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  17. SOLIDIFICATION OF THE HANFORD LAW WASTE STREAM PRODUCED AS A RESULT OF NEAR-TANK CONTINUOUS SLUDGE LEACHING AND SODIUM HYDROXIDE RECOVERY

    Energy Technology Data Exchange (ETDEWEB)

    Reigel, M.; Johnson, F.; Crawford, C.; Jantzen, C.

    2011-09-20

    quenched glasses. However, the waste form failed to meet the vapor hydration test criteria listed in the WTP contract. In addition, the waste loading in the phosphate glasses were not as high as other candidate waste forms. Vitrification of HLW waste as borosilicate glass is a proven process; however the HLW and LAW streams at Hanford can vary significantly from waste currently being immobilized. The ccc glasses show lower release rates for B and Na than the quenched glasses and all glasses meet the acceptance criterion of < 4 g/L. Glass samples spiked with Re{sub 2}O{sub 7} also passed the PCT test. However, further vapor hydration testing must be performed since all the samples cracked and the test could not be performed. The waste loading of the iron phosphate and borosilicate glasses are approximately 20 and 25% respectively. The steam reforming process produced the predicted waste form for both the high and low aluminate waste streams. The predicted waste loadings for the monolithic samples is approximately 39%, which is higher than the glass waste forms; however, at the time of this report, no monolithic samples were made and therefore compliance with the PA cannot be determined. The waste loading in the geopolymer is approximately 40% but can vary with the sodium hydroxide content in the waste stream. Initial geopolymer mixes revealed compressive strengths that are greater than 500 psi for the low aluminate mixes and less than 500 psi for the high aluminate mixes. Further work testing needs to be performed to formulate a geopolymer waste form made using a high aluminate salt solution. A cementitious waste form has the advantage that the process is performed at ambient conditions and is a proven process currently in use for LAW disposal. The Saltstone/Cast Stone formulated using low and high aluminate salt solutions retained at least 97% of the Re that was added to the mix as a dopant. While this data is promising, additional leaching testing must be performed to

  18. Solidification Of The Hanford Law Waste Stream Produced As A Result Of Near-Tank Continuous Sludge Leaching And Sodium Hydroxide Recovery

    International Nuclear Information System (INIS)

    Reigel, M.; Johnson, F.; Crawford, C.; Jantzen, C.

    2011-01-01

    quenched glasses. However, the waste form failed to meet the vapor hydration test criteria listed in the WTP contract. In addition, the waste loading in the phosphate glasses were not as high as other candidate waste forms. Vitrification of HLW waste as borosilicate glass is a proven process; however the HLW and LAW streams at Hanford can vary significantly from waste currently being immobilized. The ccc glasses show lower release rates for B and Na than the quenched glasses and all glasses meet the acceptance criterion of 2 O 7 also passed the PCT test. However, further vapor hydration testing must be performed since all the samples cracked and the test could not be performed. The waste loading of the iron phosphate and borosilicate glasses are approximately 20 and 25% respectively. The steam reforming process produced the predicted waste form for both the high and low aluminate waste streams. The predicted waste loadings for the monolithic samples is approximately 39%, which is higher than the glass waste forms; however, at the time of this report, no monolithic samples were made and therefore compliance with the PA cannot be determined. The waste loading in the geopolymer is approximately 40% but can vary with the sodium hydroxide content in the waste stream. Initial geopolymer mixes revealed compressive strengths that are greater than 500 psi for the low aluminate mixes and less than 500 psi for the high aluminate mixes. Further work testing needs to be performed to formulate a geopolymer waste form made using a high aluminate salt solution. A cementitious waste form has the advantage that the process is performed at ambient conditions and is a proven process currently in use for LAW disposal. The Saltstone/Cast Stone formulated using low and high aluminate salt solutions retained at least 97% of the Re that was added to the mix as a dopant. While this data is promising, additional leaching testing must be performed to show compliance with the PA. Compressive strength

  19. Extraction of alumina and sodium oxide from red mud by a mild hydro-chemical process.

    Science.gov (United States)

    Zhong, Li; Zhang, Yifei; Zhang, Yi

    2009-12-30

    A mild hydro-chemical process to extract Al(2)O(3) in red mud to produce sodium aluminate hydrate was investigated, and the optimum conditions of Al(2)O(3) extraction were verified by experiments as leaching in 45% NaOH solution with CaO-to-red mud mass ratio of 0.25 and liquid-to-solid ratio of 0.9, under 0.8 MPa at 200 degrees C for 3.5h. Subsequent process of extracting Na(2)O from the residue of Al(2)O(3) extraction was carried out in 7% NaOH solution with liquid-to-solid ratio of 3.8 under 0.9 MPa at 170 degrees C for 2h. Overall, 87.8% of Al(2)O(3) and 96.4% of Na(2)O were extracted from red mud. The final residues with less than 1% Na(2)O could be utilized as feedstock in construction materials. The chemical reactions taking place in both Al(2)O(3) and Na(2)O extractions from red mud are proposed.

  20. Sodium Oxybate

    Science.gov (United States)

    Sodium oxybate is used to prevent attacks of cataplexy (episodes of muscle weakness that begin suddenly and ... urge to sleep during daily activities, and cataplexy). Sodium oxybate is in a class of medications called ...

  1. Sodium Phosphate

    Science.gov (United States)

    Sodium phosphate is used in adults 18 years of age or older to empty the colon (large intestine, bowel) ... view of the walls of the colon. Sodium phosphate is in a class of medications called saline ...

  2. Determination of pKa values of alendronate sodium in aqueous solution by piecewise linear regression based on acid-base potentiometric titration.

    Science.gov (United States)

    Ke, Jing; Dou, Hanfei; Zhang, Ximin; Uhagaze, Dushimabararezi Serge; Ding, Xiali; Dong, Yuming

    2016-12-01

    As a mono-sodium salt form of alendronic acid, alendronate sodium presents multi-level ionization for the dissociation of its four hydroxyl groups. The dissociation constants of alendronate sodium were determined in this work by studying the piecewise linear relationship between volume of titrant and pH value based on acid-base potentiometric titration reaction. The distribution curves of alendronate sodium were drawn according to the determined pKa values. There were 4 dissociation constants (pKa 1 =2.43, pKa 2 =7.55, pKa 3 =10.80, pKa 4 =11.99, respectively) of alendronate sodium, and 12 existing forms, of which 4 could be ignored, existing in different pH environments.

  3. Efficacy of Plantago major, chlorhexidine 0.12% and sodium bicarbonate 5% solution in the treatment of oral mucositis in cancer patients with solid tumour: A feasibility randomised triple-blind phase III clinical trial.

    Science.gov (United States)

    Cabrera-Jaime, Sandra; Martínez, Cristina; Ferro-García, Tarsila; Giner-Boya, Pilar; Icart-Isern, Teresa; Estrada-Masllorens, Joan M; Fernández-Ortega, Paz

    2018-02-01

    Oral mucositis is one of the most common adverse effects of chemotherapy and radiotherapy. The aim of this study was to compare the efficacy of Plantago major extract versus chlorhexidine 0.12% versus sodium bicarbonate 5% in the symptomatic treatment of chemotherapy-induced oral mucositis in solid tumour cancer patients. Multicentre randomised controlled trial estimated sample of 45 solid tumour patients with grade II-III mucositis. The participants were randomised to one of three treatments, consisting of sodium bicarbonate 5% aqueous solution together with: an additional dose of sodium bicarbonate 5% aqueous solution, Plantago major extract, or chlorhexidine 0.12%. The primary outcomes were severity of mucositis, pain intensity, oral intake capacity and quality of life. The independent variable was treatment group, and confounders included sociodemographic data, neutrophil count, chemotherapy drug and dose received. Of the 50 patients enrolled, 68% (n = 34) achieved grade 0 mucositis (none), with those using the double sodium bicarbonate rinse healing in five days on average (95% CI 3.9, 6.5) versus seven days (95% CI 5.3, 9,0) for the chlorhexidine group and seven days (95% CI 5.3, 8.5) for the Plantago major group. The pain experienced by the participants lessened over the 14 days of treatment, but differences in pain intensity between the three groups did not show statistical significance (p = 0.762). Healing time was shorter with the double sodium bicarbonate solution compared to the other two rinses, but the differences were not significant. Our results suggest it may be time to reconsider the use of Plantago major extract in the management of oral mucositis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. The Zintl-Klemm concept applied to cations in oxides. I. The structures of ternary aluminates

    OpenAIRE

    Santamaría Pérez, David; Vegas, Ángel

    2003-01-01

    The structures of 94 ternary aluminates are reinterpreted on the basis of the Zintl-Klemm concept and Pearson's generalized octet rule. In aluminates of highly electropositive metals such as alkali, alkaline-earth and rare-earth metals, the Al atoms form three-dimensional skeleta which can be interpreted as if the Al atoms were behaving as Zintl polyanions, adopting the structure of either main-group elements or Zintl polyanions showing the same connectivity. The O atoms are then located clos...

  5. Coarse-Grain Molecular Dynamics Simulations to Investigate the Bulk Viscosity and Critical Micelle Concentration of the Ionic Surfactant Sodium Dodecyl Sulfate (SDS) in Aqueous Solution.

    Science.gov (United States)

    Ruiz-Morales, Yosadara; Romero-Martínez, Ascencion

    2018-03-13

    The first critical micelle concentration (CMC) of the ionic surfactant sodium dodecyl sulfate (SDS), in diluted aqueous solution, has been determined at room temperature from the investigation of the bulk viscosity, at several concentrations of SDS, by means of coarse grain molecular dynamics simulations. The coarse-grained model molecules at the mesoscale level are adopted. The bulk viscosity of SDS was calculated at several millimolar concentrations of SDS in water using the MARTINI force field by means of NVT shear Mesocite molecular dynamics. The definition of each bead in the MARTINI force field is established, as well as their radius, volume, and mass. The effect of the size of the simulation box on the obtained CMC has been investigated as well as the effect of the number of SDS molecules, in the simulations, on the formation of aggregates. The CMC, which was obtained from a graph of the calculated viscosities versus concentration, is in good agreement with reported experimental data, and do not depend on the size of the box used in the simulation. The formation of a spherical micelle-like aggregate is observed, where the dodecyl sulfate tails point inwards and the heads point outwards the aggregation micelle, in accordance with experimental observations. The advantage of using coarse grain molecular dynamics is the possibility of treating explicitly charged beads, applying a shear flow for viscosity calculation, as well as to process much larger spatial and temporal scales than atomistic molecular dynamics can. Furthermore, the CMC of SDS obtained with the coarse-grained model is in much better agreement with the experimental value than the value obtained with atomistic simulations.

  6. Effect of Ethylene diamine tetra acetic acid and sodium hypochlorite solution conditioning on microtensile bond strength of one-step self-etch adhesives

    Science.gov (United States)

    Kasraei, Shahin; Azarsina, Mohadese; Khamverdi, Zahra

    2013-01-01

    Background: Attempts to improve bond strength of self-etch adhesives can enhance the durability of composite restorations. Aims: The aim of the present study was to evaluate the effect of collagen and smear layer removal with sodium hypochlorite solution (NaOCl) and EDTA on micro-tensile bond strength (μTBS) of self-etch adhesives to dentin. Settings and Design: It was an in-vitro study. Materials and Methods: Seventy-two teeth were divided into eight groups and their crowns were ground perpendicular to their long axis to expose dentin. The teeth were polished with silicon-carbide papers. The groups were treated as follows: No conditioning, 0.5-M EDTA conditioning, 2.5% NaOCl conditioning, NaOCl + EDTA conditioning. The surfaces were rinsed and blot-dried. Clearfil S3 and I-Bond were applied according to manufacturers’ instructions and restored with Z100 composite. After 500 cycles of thermo-cycling between 5°C and 55°C, the samples were sectioned and tested for μTBS. Statistical Analysis: Data were analyzed by two-way ANOVA and Tukey-HSD test. Results: The highest μTBS was recorded with Clearfil S3 + NaOCl + EDTA, and the lowest was recorded with I-Bond without conditioning. μTBS in EDTA-and EDTA + NaOCl-treated groups was significantly higher than the control and NaOCl-conditioned groups. Conclusions: Application of EDTA or EDTA + NaOCl before one-step self-etch adhesives increased μTBS. PMID:23833459

  7. Synthesis of 2,4-dinitrophenylhydrazine loaded sodium dodecyl sulfate-coated magnetite nanoparticles for adsorption of Hg(II ions from an aqueous solution

    Directory of Open Access Journals (Sweden)

    Soheil Sobhanardakani

    2016-09-01

    Full Text Available Background: The rapid increase in agricultural and industrial development has made heavy metal pollution a serious environmental problem and public health threat; therefore, removal of heavy metals from water is important. The current study prepared DNPH@SDS@Fe3O4 nanoparticles as a novel and effective adsorbent for removal of Hg(II ions from an aqueous solution. Methods: A selective adsorbent for Hg(II was synthesized by coating Fe3O4 nanoparticles with sodium dodecyl sulfate which was further functionalized with 2,4-dinitrophenylhydrazine (2,4-DNPH. The synthesized nanoparticles were characterized by Fourier transform infrared spectroscopy (FTIR, x-ray diffraction (XRD, scanning electron microscopy (SEM and SEM–EDXSt. The effects of pH, dose of adsorbent and shaking time on adsorption capacity were investigated. The kinetics and equilibrium of adsorption of the metal ions were thoroughly studied. Results: SEM showed that the size of the nanoparticles was 20 to 35 nm. The maximum adsorption capacity for Hg(II was 164.0 mg g-1 for an adsorbent dose of 0.04 g at pH 7.0, 25°C and the initial metal concentration was 25 mg L-1,which was greater than for most adsorbents previously examined for Hg(II adsorption. Adsorption experimental data showed good correlation with the pseudo-secondorder model and Langmuir isotherm model. Conclusion: The results indicated that the DNPH@SDS@Fe3O4 nanoparticles are an efficient adsorbent for removal of heavy metal from wastewater.

  8. SOLUTIONING

    Directory of Open Access Journals (Sweden)

    Maria de Hoyos Guajardo, Ph.D. Candidate, M.Sc., B.Eng.

    2004-11-01

    Full Text Available The theory that is presented below aims to conceptualise how a group of undergraduate students tackle non-routine mathematical problems during a problem-solving course. The aim of the course is to allow students to experience mathematics as a creative process and to reflect on their own experience. During the course, students are required to produce a written ‘rubric’ of their work, i.e., to document their thoughts as they occur as well as their emotionsduring the process. These ‘rubrics’ were used as the main source of data.Students’ problem-solving processes can be explained as a three-stage process that has been called ‘solutioning’. This process is presented in the six sections below. The first three refer to a common area of concern that can be called‘generating knowledge’. In this way, generating knowledge also includes issues related to ‘key ideas’ and ‘gaining understanding’. The third and the fourth sections refer to ‘generating’ and ‘validating a solution’, respectively. Finally, once solutions are generated and validated, students usually try to improve them further before presenting them as final results. Thus, the last section deals with‘improving a solution’. Although not all students go through all of the stages, it may be said that ‘solutioning’ considers students’ main concerns as they tackle non-routine mathematical problems.

  9. Effect of aluminized fabrics on radiant protective performance of fire proximity suit materials.

    Science.gov (United States)

    Jin, Lu; Park, Pyoung Kyu; Hong, Kyoung A; Yoon, Kee Jong

    2015-03-01

    Radiant heat may be a significant component of heat exposure in the case of proximity firefighting. To combat high levels of radiant heat, fire proximity suits made of aluminized fabrics (Al-Fb) are commonly used due to their proven radiant protective performance (RPP). In this study RPP of various Al-Fb prepared using different aluminized films (Al-Fl) such as double-sided aluminized film and single-sided aluminized film and different base fabrics such as woven, knit, and nonwoven fabrics are compared. The effect of flexing on RPP and flame protective performance (FPP) of Al-Fb is also examined. The results show that RPP of Al-Fl is affected by the protective film to protect against mechanical or physical damages, and also by their structure such as whether the second reflective aluminum layer is present or not. In addition RPP of Al-Fb is also influenced by the base fabric, especially its surface roughness. The increased surface roughness combined with the damage caused to the aluminum layer after flexing result in reduction of RPP of Al-Fb. The contribution of Al-Fl to FPP of Al-Fb is not as significant as to RPP. Finally, based on the results, some points that may be important in developing and designing fire proximity suits are recommended. © The Author 2014. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

  10. Phase transformation of alumina coating by plasma assisted tempering of aluminized P91 steels

    International Nuclear Information System (INIS)

    Jamnapara, N.I.; Mukherjee, S.; Khanna, A.S.

    2015-01-01

    Highlights: • A novel plasma assisted heat treatment process for aluminized P91 steels is reported. • Plasma plays a vital role in phase transformation of Al 2 O 3 from θ to α phase. • Presence of O ∗ species in plasma facilitates θ to α transformation. - Abstract: α-Al 2 O 3 coating on aluminized surfaces are considered candidate coatings for blanket applications in fusion reactor. In order to generate α-Al 2 O 3 , aluminized P91 steel samples were subjected to normalizing and tempering treatments at 980 °C and 750 °C respectively. Oxygen plasma has been used during tempering treatment of aluminized P91 steel samples at 750 °C for 1 h. The resulting alumina coating on plasma tempered samples were compared with those of thermally tempered samples. The alumina films were characterized using XRD, XPS, and SEM–EDS techniques. Results indicate that the thermally tempered samples had θ-Al 2 O 3 coating while the plasma tempered samples had α-Al 2 O 3 coating after heat treatment. Such transformation of alumina phase was not visible without plasma. A hypothesis of θ to α-Al 2 O 3 transformation in plasma is proposed. This paper emphasizes the role of plasma processing on generation of an improved insulation coating for TBM applications in fusion reactors

  11. Lithium aluminate/zirconium material useful in the production of tritium

    Science.gov (United States)

    Cawley, W.E.; Trapp, T.J.

    A composition is described useful in the production of tritium in a nuclear reactor. Lithium aluminate particles are dispersed in a matrix of zirconium. Tritium produced by the reactor of neutrons with the lithium are absorbed by the zirconium, thereby decreasing gas pressure within capsules carrying the material.

  12. Data and properties of lithium aluminate γ LiAlO2

    International Nuclear Information System (INIS)

    Denuziere, C.; Roux, N.

    1988-01-01

    In this report are gathered and analysed the literature data until july 1st, 1984, concerning the properties of lithium aluminate γ LiAlO 2 relevant for the investigation of this compound as a tritum breeding material for a fusion reactor blanket. A french version of this report exists

  13. Some aspects of the tribological behaviour of materials in sodium

    International Nuclear Information System (INIS)

    Campbell, C.S.; Lewis, M.W.J.

    1980-08-01

    The influence of boundary lubricating films formed by reaction of metallic surfaces with oxygen-containing sodium is discussed. In general, pre-existing surface metallic oxides are reduced in high-temperature low-oxygen sodium, and tribological behaviour is accordingly poor. Chromium-containing alloys, however, can react more readily with oxygen-containing sodium to form sodium chromite, NaCrO 2 , on the alloy surfaces. Such an oxide could plausibly account for significantly improved tribological behaviour at higher oxygen levels. Sodium chromite is only marginally stable at typical reactor outlet conditions and frictional behaviour of typical chromium-containing alloys has therefore been studied as a function of rig cold trap temperature for exposure temperatures ranging from 650 to 500 0 C in order to define the effective tribological boundary. The behaviour of aluminised surfaces has also been studied and results from sliding and fretting wear tests are discussed in the context of the role of a lubricating oxide, believed to be sodium aluminate (formed by reaction of aluminium and oxygen-containing sodium) which is considerably more stable than sodium chromite at reactor outlet temperatures. (author)

  14. Sodium in diet

    Science.gov (United States)

    Diet - sodium (salt); Hyponatremia - sodium in diet; Hypernatremia - sodium in diet; Heart failure - sodium in diet ... The body uses sodium to control blood pressure and blood volume. Your body also needs sodium for your muscles and nerves to work ...

  15. Solubility of disodium 4,4′-dinitrostilbene-2,2′-disulfonate and sodium 4-nitrotoluene-2-sulfonate in aqueous organic solutions and its application feasibility in oxidation stage of DSD acid synthesis

    International Nuclear Information System (INIS)

    Zou, Wei; Xia, Qing; Zhao, Wen; Zhang, Feng-Bao; Zhang, Guo-Liang

    2014-01-01

    Highlights: • Solubility of sodium 4-nitrotoluene-2-sulfonate in two aqueous organic solution were measured using dynamic method. • Solubility of disodium 4,4′-dinitrostilbene-2,2′-disulfonate in corresponding solution were measured using dynamic method. • The experimental data were correlated with electrolyte non-random two-liquid (E-NRTL) model. • A synergistic effect on disodium 4,4′-dinitrostilbene-2,2′-disulfonate solubility was observed. • A suitable solvent for oxidation of 4-nitrotoluene-2-sulfonic to 4,4′-dinitrostilbene-2,2′-disulfonic has been suggested. -- Abstract: Solid–liquid equilibrium (SLE) measurements for disodium 4,4′-dinitrostilbene-2,2′-disulfonate (DNSNa) and sodium 4-nitrotoluene-2-sulfonate (NTSNa) in aqueous ethylene glycol monoethyl ether solution and aqueous ethylene glycol monobutyl ether solution were conducted using a dynamic method over the temperature range from (280 to 335) K. A synergistic effect on DNSNa solubility was observed with the maximum solubility at solute-free mass fraction of ethylene glycol monoethyl ether w 3 0 =0.4000 and solute-free mass fraction of ethylene glycol monobutyl ether w 4 0 =0.5999, respectively. The solubility data were correlated using the thermodynamic electrolyte non-random two-liquid (E-NRTL) model and model parameters were determined simultaneously. Aqueous ethylene glycol monobutyl ether solution at solute-free mass fraction of ethylene glycol monobutyl ether w 4 0 =0.2000 was found to be suitable solvent medium for the oxidation of 4-nitrotoluene-2-sulfonic acid (NTS) to 4,4′-dinitrostilbene-2,2′-disulfonic acid (DNS) and the conclusion was confirmed using the static analytical method combined with UV–VIS spectrophotometer

  16. Hot-Dip Aluminizing on AISI F55–UNS S32760 Super Duplex Stainless Steel Properties: Effect of Thermal Treatments

    Directory of Open Access Journals (Sweden)

    Andrea Francesco Ciuffini

    2017-11-01

    Full Text Available The behavior of super duplex stainless steels AISI F55-UNS S32760 in hot-dip aluminizing process has been studied, investigating the influence of cold working and of different initial microstructures obtained through a preliminary thermal treatment. The microstructural features examined are the secondary austenite precipitation, the static recovery of ferrite and the thermal dissolution of austenite within ferritic matrix. The hot-dip aluminizing temperature has been optimized through sessile drop tests. The treatment has been performed at 1100 °C for 300 s, 900 s and 2700 s. A strong chemical interaction occurs, generating intermetallic compounds at the interface. Molten aluminum interacts exclusively with the ferritic phase due to its much higher diffusivity in this phase coupled with its marked ferrite-stabilizer behavior. Thus, the influence of cold working is not remarkable, since the strains are mainly allocated by austenitic phase. The diffusivity of aluminum increases due to lattice defects thermally generated and, mainly, to influence given by grain boundaries, multiplied by secondary austenite precipitation, which act as short-circuit diffusion paths. Ni and Cr contents in the ferritic matrix have an influence but not highly relevant. Then, the best starting condition of the super duplex stainless steel substrates, to obtain a thick interfacial layer, are the thermal annealing at 1080 °C for 360 s/mm after a solution thermal treatment at 1300 °C for 60 s/mm.

  17. Hidden Sodium

    Centers for Disease Control (CDC) Podcasts

    2013-03-04

    In this podcast, learn about reducing sodium intake by knowing what to eat and the main sources of sodium in the diet. It's important for a healthy lifestyle.  Created: 3/4/2013 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 3/4/2013.

  18. Dietary sodium

    DEFF Research Database (Denmark)

    Graudal, Niels

    2015-01-01

    The 2013 Institute of Medicine (IOM) report "Sodium Intake in Populations: Assessment of Evidence" did not support the current recommendations of the IOM and the American Heart Association (AHA) to reduce daily dietary sodium intake to below 2,300 mg. The report concluded that the population......-based health outcome evidence was not sufficient to define a safe upper intake level for sodium. Recent studies have extended this conclusion to show that a sodium intake below 2,300 mg/day is associated with increased mortality. In spite of this increasing body of evidence, the AHA, Centers for Disease...... Control (CDC), other public health advisory bodies, and major medical journals have continued to support the current policy of reducing dietary sodium....

  19. Microstructural and compositional change of NaOH-activated high calcium fly ash by incorporating Na-aluminate and co-existence of geopolymeric gel and C–S–H(I)

    KAUST Repository

    Oh, Jae Eun

    2012-05-01

    This study explores the reaction products of alkali-activated Class C fly ash-based aluminosilicate samples by means of high-resolution synchrotron X-ray diffraction (HSXRD), scanning electron microscope (SEM), and compressive strength tests to investigate how the readily available aluminum affects the reaction. Class C fly ash-based aluminosilicate raw materials were prepared by incorporating Na-aluminate into the original fly ashes, then alkali-activated by 10 M NaOH solution. Incorporating Na-aluminate reduced the compressive strength of samples, with the reduction magnitude relatively constant regardless of length of curing period. The HSXRD provides evidence of the co-existence of C-S-H with geopolymeric gels and strongly suggests that the C-S-H formed in the current system is C-S-H(I). The back-scattered electron images suggest that the C-S-H(I) phase exists as small grains in a finely intermixed form with geopolymeric gels. Despite providing extra source of aluminum, adding Na-aluminate to the mixes did not decrease the Si/Al ratio of the geopolymeric gel. © 2012 Elsevier Ltd.

  20. Effect of sodium acetate on the volumetric behaviour of some mono-, di-, and tri-saccharides in aqueous solutions over temperature range (288.15 to 318.15) K

    Energy Technology Data Exchange (ETDEWEB)

    Banipal, Parampaul K., E-mail: pkbanipal@yahoo.co [Department of Chemistry, Guru Nanak Dev University, Amritsar 143 005 (India); Singh, Vickramjeet [Department of Chemistry, Guru Nanak Dev University, Amritsar 143 005 (India); Banipal, Tarlok S. [Department of Applied Chemistry, Guru Nanak Dev University, Amritsar 143 005 (India)

    2010-01-15

    The standard partial molar volumes, V{sub 2}{sup 0} at infinite dilution of eight monosaccharides [D(+)-xylose, D(-)-arabinose, D(-)-ribose, L(-)-sorbose, D(-)-fructose, D(+)-galactose, D(+)-glucose, and D(+)-mannose], six disaccharides [D(+)-cellobiose, sucrose, D(+)-melibiose, D(+)-lactose monohydrate, D(+)-trehalose dihydrate, and D(+)-maltose monohydrate] and two trisaccharides [D(+)-melizitose and D(+)-raffinose pentahydrate] (molalities of saccharides range from (0.03 to 0.12) mol . kg{sup -1}) have been determined in water and in (0.5, 1.0, 2.0, and 3.0) mol . kg{sup -1} aqueous sodium acetate solutions at temperatures, T = (288.15, 298.15, 308.15, and 318.15) K from density measurements using a vibrating-tube digital densimeter. From these results, corresponding standard partial molar volumes of transfer, DELTA{sub t}V{sub 2}{sup 0} have been determined for the transfer of various saccharides from water to aqueous solutions of sodium acetate. Positive values of DELTA{sub t}V{sub 2}{sup 0} were obtained for most of the saccharides, whose magnitude increase with the concentration of sodium acetate as well as temperature. However, negative DELTA{sub t}V{sub 2}{sup 0} values were observed for L(-)-sorbose, D(-)-fructose and D(+)-xylose at lower concentrations of co-solute. The negative magnitude of DELTA{sub t}V{sub 2}{sup 0} values decrease with rise of temperature from (288.15 to 318.15) K. Pair and higher order volumetric interaction coefficients have been determined by using McMillan-Mayer theory. Partial molar expansion coefficients, (partial derivV{sub 2}{sup 0}/partial derivT){sub p} and the second derivatives (partial deriv{sup 2}V{sub 2}{sup 0}/partial derivT{sup 2}){sub p} have also been estimated. These parameters have been utilized to understand various mixing effects in aqueous solutions due to the interactions between solute (saccharide) and co-solute (sodium acetate).

  1. Preparation and corrosion resistance of a nanocomposite plasma electrolytic oxidation coating on Mg-1%Ca alloy formed in aluminate electrolyte containing titania nano-additives

    DEFF Research Database (Denmark)

    Daroonparvar, Mohammadreza; Yajid, M. A. M.; Yusof, N. M.

    2016-01-01

    spectroscopy (EIS), and immersion tests were performed in 3.5% NaCl solution to study corrosion behavior of the coated samples in reference to the uncoated Mg alloy. The coating with 4 g/L concentration of nanoparticles showed the highest microhardness, lowest hydrophilic properties and highest corrosion...... resistance. This coating substantially diminishes the Mg dissolution in the in 3.5% NaCl solution and increases the charge transfer resistance of the Mg alloy. Although higher concentrations of nanoparticles enhanced the defect density in the coating, they resulted in lower corrosion resistance. © 2016......Titania nanoparticles were utilized as suspension in alkaline aluminate electrolyte to form nanocomposite coatings on magnesium alloy containing 1 wt% calcium by plasma electrolytic oxidation process. Microhardness, wettability, potentiodynamic polarization, wettability, electrochemical impedance...

  2. 21 CFR 522.1145 - Hyaluronate sodium.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Hyaluronate sodium. 522.1145 Section 522.1145 Food... Hyaluronate sodium. (a)(1) Specifications. Each milliliter of sterile aqueous solution contains 10 milligrams of hyaluronate sodium. (2) Sponsor. See 000009 in § 510.600(c). (3) Conditions of use—(i) Amount...

  3. The Effect of Nano-Aluminumpowder on the Characteristic of RDX based Aluminized Explosives Underwater Close-Filed Explosion

    OpenAIRE

    Junting Yin; Baohui Yuan; Tao Zhou; Gang Li; Xinlian Ren

    2017-01-01

    In order to investigate the effect of nano-aluminum powder on the characteristic of RDX based aluminized explosives underwater closed-filed explosions, the scanning photographs along the radial of the charges were gained by a high speed scanning camera. The photographs of two different aluminized explosives underwater explosion have been analyzed, the shock wave curves and expand curves of detonation products were obtained, furthermore the change rules of shock waves propagation velocity, sho...

  4. High toughness alumina/aluminate: The role of hetero-interfaces

    International Nuclear Information System (INIS)

    Brito, M.E.; Yasuoka, M.; Kanzaki, S.

    1996-01-01

    Silica doped alumina/aluminate materials present a combination of high strength and high toughness not achieved before in other alumina systems, except for transformation toughened alumina. The authors have associated the increase in toughness to crack bridging by anisotropically grown alumina grains with concurrent interfacial debonding of these grains. A HREM study of grain boundaries and hetero-interface structures in this material shows the absence of amorphous phases at grain boundaries. Local Auger electron analysis of fractured surfaces revealed the coexistence of Si and La at the grain facets exposed by the noticeable intergranular fracture mode of this material. It is concluded that a certain and important degree of boundaries weakness is related to both presence of Si at the interfaces and existence of alumina/aluminate hetero-interfaces

  5. Quantitative phase determination by X-ray diffractometry in electrofused calcium aluminate cements

    International Nuclear Information System (INIS)

    Zanetti, S.M.; Franco, M.B.; Splettstoser Junior, J.; Placido, W.F.

    1989-01-01

    The knowledge of the percentual composition of phases in calcium aluminate cements and clinkers is of great importance to foresight the behaviour of the cement and refractory concretes made thereof. There are some analytical techniques for these determinations, optical and eletronic microscopy as well as selective chemical attacks, each technique presenting its own difficulties. Using pure phases of CA, CA 2 , C 2 AS and C 12 A 7 obtained by electrofusion in a laboratory electric are furnace, calibration curves were developed for X-ray diffratometric determination of phases. The method is very efficient for determination of CA, CA 2 , C 2 AS and ∝ - A1 2 O 3 . The determination of C 12 A 7 presents some variations due to its low concentration in electrofused clinkers. The method finds practical application in quality control of calcium aluminate cements [pt

  6. The aluminization of 600k WLS fibers for the TileCal/ATLAS/LHC

    CERN Document Server

    Saraiva, J G; Maneira, M J P; Patriarca, J; Wemans, A

    2003-01-01

    The TILE CALorimeter, the hadronic sampling calorimeter of ATLAS/LHC /CERN, is made of iron and polystyrene scintillating tiles. The light produced in scintillating tiles is absorbed and guided to the photomultipliers (PMTs) through Wave Length Shifter (WLS) optical fibers. To optimize the detection of jets and muons, the top of the fibers away of the PMTs is coated with an aluminum mirror, that increases the light output in asymptotically equal to 75% and enhances the uniformity light output by asymptotically equal to 10%. The aluminum mirror is produced by Magnetron Sputtering, that adds to an excellent reproducibility a minimal thermal aggression important for proper film adhesion to the plastic surface. A dedicated machine for mass production of the ATLAS WLS aluminized fibers has been designed and constructed fulfilling the critical production optical and time requirements. The aluminization of the fibers and their quality control started in August 1999 and went on continuously until May 2002. The qualit...

  7. Thermodynamic properties of solutions of sodium di-hydrogen phosphate in (1-propanol + water) mixed-solvent media over the temperature range of (283.15 to 303.15) K

    International Nuclear Information System (INIS)

    Sadeghi, Rahmat; Parhizkar, Hana

    2008-01-01

    The apparent molar volume and apparent molar isentropic compressibility of solutions of sodium di-hydrogen phosphate (NaH 2 PO 4 ) in (1-propanol + water) mixed-solvent media with alcohol mass fractions of 0.00, 0.05, 0.10, and 0.15 are reported over the range of temperature (283.15 to 303.15) K at 5 K intervals. The results were fitted to a Redlich-Mayer type equation from which the apparent molar volume and apparent molar isentropic compressibility of the solutions at the infinite dilution were also calculated at the working temperature. The results show a positive transfer volume of NaH 2 PO 4 from an aqueous solution to an aqueous 1-propanol solution. The apparent molar isentropic compressibility of NaH 2 PO 4 in aqueous 1-propanol solutions is negative and it increases with increasing the concentration of NaH 2 PO 4 , 1-propanol, and temperature. Electrical conductivity and refractive index of the solutions are also studied at T = 298.15 K. The effects of the electrolyte concentration and relative permittivity of the medium on the molar conductivity were also investigated

  8. Effect of X-Rays on the Mechanical Properties of Aluminized FEP Teflon(trademark)

    Science.gov (United States)

    Gaier, James R.; Brinkmeier, Michael R.; Gaier, Elizabeth M.

    1999-01-01

    Pieces of the multilayer insulation (MLI) that is integral to the thermal control of the Hubble Space Telescope (HST) have been returned by two servicing missions after 3.6 and 6.8 years in orbit. They reveal that the outer layer, which is made from 5 mil (0.13 mm) thick aluminized fluorinated ethylenepropylene (FEP) Teflon. has become severely embrittled. Although possible agents of this embrittlement include electromagnetic radiation across the entire solar spectrum, trapped particle radiation, atomic oxygen, and thermal cycling, intensive investigations have not yielded unambiguous causes. Previous studies utilizing monoenergetic photons in the 69-1900 eV range did not cause significant embrittlement, even at much higher doses than were experienced by the HST MLI. Neither did x-rays in the 3 to 10 keV range generated in a modified electron bean evaporator. An antidotal aluminized FEP sample that was exposed to an intensive dose from unfiltered Mo x-ray radiation from a rotating anode generator, however, did show the requisite embrittlement. Thus, a study was undertaken to determine the effects of x-ray exposure on the embrittlement of aluminized FEP in hopes that it might elucidate the HST MLI degradation mechanism. Tensile specimens of aluminized 5 mil thick FEP were exposed to a constant fluence of unfiltered x-ray radiation from a Mo target whose maximum energy ranged from 20-60 kV. Other samples were annealed, thermally cycled (100x) between 77-333 K, or cycled and irradiated. Tensile tests and density measurements were then performed on the samples. Only the samples which had been irradiated had the drastically reduced elongation-to-break, characteristic of the HST samples. Thermal cycling may accelerate the embrittlement, but the effect was near the scatter in the measurements. Annealing and thermal cycling had no apparent effect. Only the samples which had been irradiated and annealed showed significant density increases, likely implicating polymer chain

  9. Lithium aluminates and tritium production; Aluminatos de litio y produccion de tritio

    Energy Technology Data Exchange (ETDEWEB)

    Carrera G, L.M.; Palacios G, O.; Bosch G, P. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1997-07-01

    In this work it is studied the crystalline structure of lithium aluminates prepared by three different methods, namely: solid state reaction, humid reaction and sol-gel reaction. The analysis methods are the X-ray diffractometry and the scanning and transmission electron microscopy. This study is realized as in original materials as in irradiated materials at the TRIGA Mark reactor, to correlate the synthesis method with response of these materials to the mixed irradiation of nuclear reactor. (Author)

  10. Calcium aluminates potential for endodontics and orthopedics applications; Aluminatos de calcio e seu potencial para aplicacao em endodontia e ortopedia

    Energy Technology Data Exchange (ETDEWEB)

    Santos, G.L. dos; Andrade, T.L.; Oliveira, I.R., E-mail: ivonero@univap.br [Universidade do Vale do Paraiba (UNIVAP), Sao Jose dos Campos, SP (Brazil); Pandolfelli, V.C. [Universidade Federal de Sao Carlos (DEMa/UFSCar), SP (Brazil)

    2011-07-01

    The mostly used material in the areas of endodontics (MTA, mineral trioxide aggregate) and bone reconstruction (PMMA, polymethyl methacrylate) present some limiting properties requiring thus changes in their compositions as well as the development of alternative materials. In this context, a novel biomaterial-based calcium aluminate cement (CAC) has been studied in order to keep the positive properties and clinical applications of MTA and PMMA, overcoming some their disadvantages. Recent studies involving the use of CAC are based on commercial products consisting of a mixture of phases. Improvements can be attained by searching the synthesis routes of CAC aiming the proper balance between the phases and the control of impurities that may impair its performance in applications in the areas of health. By the optimization of the CAC phases production, this article aims to present their characterization based on hydration temperature; working time and setting time; pH, ions solubilization and dissolution in contact with water and different solutions of simulated body fluid. The results indicated the CA phase as the most suitable for application in the areas of health. (author)

  11. Polyelectrolyte-surfactant complexes formed by poly[3,5-bis(trimethylammoniummethyl)4-hydroxystyrene iodide]-block-poly(ethylene oxide) and sodium dodecyl sulfate in aqueous solutions

    Czech Academy of Sciences Publication Activity Database

    Štěpánek, M.; Matějíček, P.; Procházka, K.; Filippov, Sergey K.; Angelov, Borislav; Šlouf, Miroslav; Mountrichas, G.; Pispas, S.

    2011-01-01

    Roč. 27, č. 9 (2011), s. 5275-5281 ISSN 0743-7463 R&D Projects: GA MŠk ME09059; GA ČR GCP205/11/J043; GA ČR GAP208/10/0353 Institutional research plan: CEZ:AV0Z40500505 Keywords : polyelectrolyte-surfactant complexes * sodium dodecyl sulfate * small-angle X-ray scattering Subject RIV: CD - Macromolecular Chemistry Impact factor: 4.186, year: 2011

  12. One-Dimension Nonisentropic Model for the Flow of Aluminized Explosive Products

    Directory of Open Access Journals (Sweden)

    Ji Duan

    2017-01-01

    Full Text Available A new analytic model of aluminized explosive products based on the method of characteristics for planar isentropic flow is proposed herein. The contribution of Al oxidation in the explosion products is investigated analytically. The flow behind the detonation front cannot be treated as isentropic due to the Al oxidation in the products. To solve the nonisentropic flow field of aluminized explosives products analytically, the assumption of local isentropic process is proposed. Based on this assumption, the flow field behind the detonation front of aluminized explosive is a function of only the reacted aluminum mass fraction in each time range. The metal plate test was conducted with the metal plate driven by RDX/Al/wax (76/20/4 and RDX/LiF/wax (76/20/4. The reacted aluminum mass can be obtained indirectly from the experiment results. The reacted aluminum mass was then applied to the analytic model, and the velocity of metal plate driven by RDX/Al/wax (76/20/4 and RDX/LiF/wax (76/20/4 was calculated. The final velocity of the metal plate driven by RDX/Al/wax was 7.8% higher than that driven by RDX/LiF/wax.

  13. High-resolution 27Al NMR study of calcium aluminate catalysts

    International Nuclear Information System (INIS)

    Yakerson, V.I.; Nissenbaum, V.D.; Golosman, E.Z.; Mastikhin, V.M.

    1987-01-01

    The high-resolution 27 Al NMR spectra of calcium aluminates, calcium hydroaluminates, and calcium alumina supports and catalysts have been studied. The structures of the anhydrous calcium aluminates (CaAl 2 O 3 , CaAl 4 O 7 , 3CaO x Al 2 O 3 , 12CaO x 7Al 2 O 3 , talyum) consist of aluminum-oxygen tetrahedra and contain various types of aluminum atoms, the nonequivalence of which increases in going from strongly basic to weakly basic aluminates. In the NMR spectrum the signal of octahedrally coordinated aluminum is due to disordered aluminum-oxygen structures. During the forming of the calcium-alumina catalysts and supports the process [AlO 4 ] → [AlO 6 ] takes place during hydration, and [AlO 6 ] → [AlO 4 ] during thermolysis; the nonequivalence of the tetrahedrally coordinated aluminum atoms decreases, while the [AlO 4 ]:[AlO 6 ] ratio decreases as the degree of hydration increases

  14. Driving Ability of HMX based Aluminized Explosive Affected by the Reaction Degree of Aluminum Powder

    Science.gov (United States)

    Duan, Yingliang

    2017-06-01

    Due to the time scale of aluminum reaction, the detonation process of the aluminized explosive becomes very complex, and there is less agreement on the reaction mechanism of aluminum powder. If the reaction of aluminum occurs in the reaction zone, the energy released will further strengthen the work ability of detonation wave. So it is very important for characterizing the detonation parameters and detonation driving ability to accurately understand the role of aluminum powder in the reaction zone. In this paper, detonation driving process of HMX based aluminized explosive was studied by cylinder test, obtaining the expansion track of cylinder wall. In order to further research the reaction degree (λ) of aluminum in the reaction zone, the thermodynamic program VHL was used to calculate the detonation process at different reaction degrees, obtaining the parameters of detonation products thermodynamic state. Using the dynamic software LS-DYNA and the JWL equation of state by fitting the pressure and relative volume relationship, the cylinder test was simulated. Compared with the experimental results, when the reaction degree is 20%, the driving ability is found to be in agreement with measured ones. It is concluded that the driving ability of HMX based aluminized explosive can be more accurately characterized by considering the reaction degree of aluminum powder in the reaction zone.

  15. Tritium release from lithium silicate and lithium aluminate, in-reactor and out-of-reactor

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, A.B. Jr.

    1976-09-01

    Studies were conducted to determine the generation and evolution of tritium and helium in lithium aluminate (LiAlO/sub 2/) and lithium silicate (Li/sub 2/SiO/sub 3/) by the reaction: Li/sup 6/ + n ..-->.. /sup 4/He + T. Targets were irradiated 4.4 days in the K-West Reactor snout facility. (Silicate GVR* approximately 2.0 cc/cc; aluminate GVR approximately 1.4 cc/cc.) Gas release in-reactor was determined by post-irradiation drilling experiments on aluminum ampoules containing silicate and aluminate targets. In-reactor tritium release (at approximately 100/sup 0/C) was found to decrease linearly with increasing target density. Tritium released in-reactor was primarily in the noncondensible form (HT and T/sub 2/), while in laboratory extractions (300-1300/sup 0/C), the tritium appeared primarily in the condensible form (HTO and T/sub 2/O). Concentrations of HT (and presumably HTO) were relatively high, indicating moisture pickup in canning operations or by inleakage of moisture after the capsule was welded. Impurities in extracted gases included H/sub 2/O, CO/sub 2/, CO, O/sub 2/, H/sub 2/, NO, SO/sub 2/, SiF/sub 4/ and traces of hydrocarbons.

  16. Tritium release from lithium silicate and lithium aluminate, in-reactor and out-of-reactor

    International Nuclear Information System (INIS)

    Johnson, A.B. Jr.

    1976-09-01

    Studies were conducted to determine the generation and evolution of tritium and helium in lithium aluminate (LiAlO 2 ) and lithium silicate (Li 2 SiO 3 ) by the reaction: Li 6 + n → 4 He + T. Targets were irradiated 4.4 days in the K-West Reactor snout facility. (Silicate GVR* approximately 2.0 cc/cc; aluminate GVR approximately 1.4 cc/cc.) Gas release in-reactor was determined by post-irradiation drilling experiments on aluminum ampoules containing silicate and aluminate targets. In-reactor tritium release (at approximately 100 0 C) was found to decrease linearly with increasing target density. Tritium released in-reactor was primarily in the noncondensible form (HT and T 2 ), while in laboratory extractions (300-1300 0 C), the tritium appeared primarily in the condensible form (HTO and T 2 O). Concentrations of HT (and presumably HTO) were relatively high, indicating moisture pickup in canning operations or by inleakage of moisture after the capsule was welded. Impurities in extracted gases included H 2 O, CO 2 , CO, O 2 , H 2 , NO, SO 2 , SiF 4 and traces of hydrocarbons

  17. Zinc-aluminates for an in situ sulfur reduction in cracked gasoline

    Energy Technology Data Exchange (ETDEWEB)

    Quintana-Solorzano, R.; Valente, J.S.; Hernandez-Beltran, F.J.; Castillo-Araiza, C.O. [Instituto Mexicano del Petroleo, Eje Central Lazaro Cardenas Norte 152 C.P., 07730 Mexico, D.F. (Mexico)

    2008-05-30

    Using additives remains as an attractive alternative for an in situ sulfur reduction in cracked gasoline since it is a practical, flexible and economical option. Zinc-aluminates prepared by the sol-gel method are used as additives for reducing sulfur in gasoline from the cracking of a high-sulfur feed in a fixed-bed bench reactor. Products distribution and feed conversion are not dramatically altered after incorporating the additive to the base catalyst with some effect on gasoline and its octane number and coke. A decrease in the gasoline sulfur content of up to 35 wt% including benzothiophene, and up to 50% excluding benzothiophene, is observed when blending the zinc-aluminates to the base catalyst, which is caused by lowering the C{sub 1} to C{sub 4} alkyl-thiophenes content. The zinc content of the zinc-aluminates has a positive effect on the gasoline sulfur reduction. It is suggested that together with the direct cracking of adsorbed thiophenic species on the additive, a further gasoline sulfur decrease is possible through cracking of saturated thiophenic species formed by hydrogenation of adsorbed thiophenic species with hydrogen produced in situ in the additive. The obtained results also demonstrate that solids with higher Lewis acidity are not unfailingly the most effective for gasoline sulfur reduction. (author)

  18. Mechanical properties of aluminized CoCrAlY coatings in advanced gas turbine blades

    Energy Technology Data Exchange (ETDEWEB)

    Kameda, J.; Bloomer, T.E. [Ames Lab., IA (United States)]|[Iowa State Univ., Ames, IA (United States). Center for Advanced Technology Dept.; Sugita, Y.; Ito, A. [Chuba Electric Power Co., Nagoya (Japan). Electric Power R and D Center; Sakurai, S. [Hitachi Ltd. (Japan). Mechanical Engineering Research Lab.

    1997-07-01

    The microstructure/composition and mechanical properties (22-950 C) in aluminized CoCrAlY coatings of advanced gas turbine blades have been examined using scanning Auger microprobe and a small punch (SP) testing method. Aluminized coatings were made of layered structure divided into four regimes: (1) Al enriched and Cr depleted region, (2) Al and Cr graded region, (3) fine grained microstructure with a mixture of Al and Cr enriched phases and (4) Ni/Co interdiffusion zone adjacent to the interface SP tests demonstrated strong dependence of the deformation and fracture behavior on the various coatings regimes. Coatings 1 and 2 showed higher microhardness and easier formation of brittle cracks in a wide temperature range, compared to coatings 3 and 4. The coating 3 had lower room temperature ductility and conversely higher elevated temperature ductility than the coating 4 due to a precipitous ductility increase above 730 C. The integrity of aluminized coatings while in-service is discussed in light of the variation in the low cycle fatigue life as well as the ductility in the layered structure.

  19. The Uses of Copper and Zinc Aluminates to Capture and Convert Carbon dioxide to Syn-gas at Higher Temperature

    Directory of Open Access Journals (Sweden)

    R.Y. Raskar

    2014-03-01

    Full Text Available The uses of copper and zinc aluminates to capture and convert the CO2 to syn-gas were studied at higher temperatures. The samples of copper and zinc aluminates were prepared by solid-solid fusion method by calcining in air at 900 oC for 3 h. Those samples were characterized by acidity/alkalinity, surface area, XRD pattern, IR, SEM images and screening to capture CO2 at the different temperatures. The phases Cu2O, CuO, ZnO, CuAl2O4 and ZnAl2O4 were found to be in the samples of zinc and copper aluminates. Acidity and surface area of the samples of copper and zinc aluminates were found to be in the ranges from 0.063 to 9.37 mmol g-1 and 3.04 to 11.8 m2 g-1, respectively. The captured CO2 by the samples of copper and zinc aluminates was found to be 19.92 to 31.52 wt% for the temperature range 40 to 850 oC. The captured CO2 at 550 oC by variable Zn/Al and Cu/Al mol ratio from 0.5 to 6 of the samples of copper and zinc aluminates was found to be 12.81 to 18.04 wt%. The reduction of carbon dioxide by zinc and copper aluminates was observed. The conversion of CO2 by methane over variable mol ratio of Cu/Al and Zn/Al in copper and zinc aluminates, respectively, at 500 oC showed the production of syn-gas by using the gas hourly space velocities (GHSV 12000, 12000 and 6000 ml. h-1. g-1 of helium, CO2 and methane. The conversions of CO2 by methane over the samples of zinc and copper aluminates were studied at different mol ratios of CO2 to methane.  © 2014 BCREC UNDIP. All rights reservedReceived: 13rd May 2013; Revised: 8th November 2013; Accepted: 8th November 2013[How to Cite: Raskar, R.Y., Gaikwad, A.G. (2014. The Uses of Copper and Zinc Aluminates to Cap-ture and Convert Carbon Dioxide to Syn-gas at Higher Temperature. Bulletin of Chemical Reaction Engineering & Catalysis, 9 (1: 1-15. (doi:10.9767/bcrec.9.1.4899.1-15[Permalink/DOI: http://dx.doi.org/10.9767/bcrec.9.1.4899.1-15

  20. Formation process of micro arc oxidation coatings obtained in a sodium phytate containing solution with and without CaCO{sub 3} on binary Mg-1.0Ca alloy

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, R.F. [School of Material and Electromechanics, Jiangxi Science and Technology Normal University, Nanchang 330013 (China); Zhang, Y.Q. [Zhejiang DunAn Light Alloy Technology CO,.LTD, Zhuji 311835 (China); Hunan University of Science and Technology, Xiangtan 411201 (China); Zhang, S.F.; Qu, B. [School of Material and Electromechanics, Jiangxi Science and Technology Normal University, Nanchang 330013 (China); Guo, S.B. [Hunan University of Science and Technology, Xiangtan 411201 (China); Xiang, J.H., E-mail: xiangjunhuai@163.com [School of Material and Electromechanics, Jiangxi Science and Technology Normal University, Nanchang 330013 (China)

    2015-01-15

    Highlights: • Compared to the Mg phase, the area of Mg{sub 2}Ca phase is much smaller. • The coatings are preferentially developed on the area adjacent to Mg{sub 2}Ca phase. • During MAO process, some sodium phytate molecules are hydrolyzed. • Anodic coatings are developed from uneven to uniform. - Abstract: Micro arc oxidation (MAO) is an effective method to improve the corrosion resistance of magnesium alloys. In order to reveal the influence of alloying element Ca and CaCO{sub 3} electrolyte on the formation process and chemical compositions of MAO coatings on binary Mg-1.0Ca alloy, anodic coatings after different anodizing times were prepared on binary Mg-1.0Ca alloy in a base solution containing 3 g/L sodium hydroxide and 15 g/L sodium phytate with and without addition of CaCO{sub 3}. The coating formation was studied by using scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The results show that Mg-1.0Ca alloy is composed of two phases, the Mg phase and Mg{sub 2}Ca phase. After treating for 5 s, the coating began to develop and was preferentially formed on the area nearby Mg{sub 2}Ca phase, which may be resulted from the intrinsic electronegative potential of the Mg phase than that of Mg{sub 2}Ca phase. Anodic coatings unevenly covered the total surface after 20 s. After 80 s, the coatings were uniformly developed on Mg-1.0Ca alloy with micro pores. During MAO process, some sodium phytate molecules are hydrolyzed into inorganic phosphate. CaCO{sub 3} has minor influence on the calcium content of the obtained MAO coatings.

  1. Approach to corrosion mechanisms for a carbon steel in a solution of sodium chloride at 3 pc and its inhibition by means of organic molecules. Compared benefit of the use of stationary and transient electrochemical methods

    International Nuclear Information System (INIS)

    Duprat, Michel

    1981-01-01

    Within the context of an increased use of seawater as coolant in various industrial installations, this research thesis had two main objectives: the search for inhibitor organic compounds with optimal efficiency, and a better understanding of the mechanisms of corrosion inhibition by the best compounds within the considered organic compounds. After having reported a bibliographical study on carbon steel corrosion in seawater or in a sodium chloride solution at 3 pc, and on the inhibition of this corrosion, the author presents the experimental conditions (materials and methods). He reports the use of stationary and un-stationary electrochemical methods for the study of the steel-solution interface without inhibitor in order to get a better knowledge of corrosion electrochemical processes and to determine more precisely the corrosion rate. The last part addresses the study of the same interface but in presence of various inhibitors

  2. Precipitation of lysozyme with sodium succinate, sodium tartrate and sodium citrate: Solubility and osmotic second virial coefficient data

    International Nuclear Information System (INIS)

    López Vélez, José Sebastián; Azzoni, Adriano Rodrigues; Pessoa Filho, Pedro de Alcantara

    2017-01-01

    Highlights: • The solubility of lysozyme in biodegradable salt solutions was investigated. • Studied biodegradable salts: sodium succinate, sodium tartrate and sodium citrate. • Sodium succinate and sodium tartrate are promising salting-out agents. • Osmotic second virial coefficient (B 22 ) of lysozyme was also investigated. • Values of B 22 indicate that crystallization may be achieved using these salts. - Abstract: Precipitation and crystallization are unit operations widely used to concentrate and purify proteins in biotechnology industry. In this work, the potential use of the biodegradable salts sodium succinate, sodium tartrate and sodium citrate to reduce the solubility of proteins is investigated. Lysozyme was studied as a model protein. The solubility of lysozyme in aqueous solutions of sodium succinate, sodium tartrate and sodium citrate was experimentally determined as a function of the ionic strength and pH at 298.2 K. All these salts induce the precipitation of lysozyme, being sodium succinate the most effective one to reduce the solubility of this protein. The osmotic second virial coefficient of lysozyme as a function of the ionic strength was also determined using self-interaction chromatography at 298.2 K and pH 8.5. The experimental data show that the value of the second virial coefficient is negative at the investigated conditions and lies mostly within or close to the crystallization slot, i.e., the range of values of this coefficient for which the formation of crystals is favored.

  3. Propriedades e bioatividade de um cimento endodôntico à base de aluminato de cálcio Properties and bioactivity of endodontic calcium aluminate cement

    Directory of Open Access Journals (Sweden)

    I. R. Oliveira

    2011-09-01

    Full Text Available Desde sua introdução na endodontia como um material retro-obturador e selador de defeitos da raiz dental, o agregado de trióxido mineral (MTA tem sido considerado como um material endodôntico revolucionário. Apesar disso, este material apresenta algumas propriedades limitantes, necessitando alterações em sua composição bem como desenvolvimento de novos materiais. Assim, o objetivo desse trabalho foi mostrar a influência de aditivos no desenvolvimento de um cimento endodôntico à base de cimento de aluminato de cálcio (ECAC. Além disso, foram avaliadas as propriedades do ECAC em comparação com o MTA, quando em contato com solução de fluido corporal simulado (SBF. Testes de manipulação e medidas de resistência à compressão, porosidade aparente, tempo de endurecimento, pH e condutividade iônica, foram realizados para os materiais MTA puro e ECAC contendo aditivos. Considerando as propriedades apresentadas pelo ECAC, este material alternativo pode ser indicado para múltiplas aplicações em endodontia.The mineral trioxide aggregate (MTA, a material primarily developed as a root-end filling has been extensively investigated as an innovative product for endodontic applications. However, changes in its formulation/composition involving its mineral aggregates and the development of alternatives of materials have been proposed in an attempt to overcome its negative physical-chemical characteristics. In this work, the influence of additives addition on the development of a novel endodontic cement based on calcium aluminate, has been evaluated. In addition, the properties of endodontic calcium aluminate cement (ECAC were compared with the gold standard mineral-trioxide-aggregate in contact with simulated body fluid (SBF. Manipulation tests and measurements of compressive strength, apparent porosity, setting time, pH and ionic conductivity were carried out on plain MTA and calcium aluminate cement with and without various additives

  4. Conductometric study of sodium dodecyl sulfate - nonionic surfactant (Triton X-100, Tween 20, Tween 60, Tween 80 or Tween 85 mixed micelles in aqueous solution

    Directory of Open Access Journals (Sweden)

    Ćirin Dejan M.

    2012-01-01

    Full Text Available The present study is concerned with the determination of the critical micelle concentration (cmc of mixed micelles of sodium dodecyl sulfate with one of five nonionic surfactants (Triton X-100, Tween 20, Tween 60, Tween 80 or Tween 85 from conductance measurements. Based on the calculated values of the β parameters we have noticed that SDS-nonionic surfactants mostly showed strong synergistic effect. It was found that nonionic surfactants with mainly longer and more hydrophobic tail show stronger interactions with hydrophobic part of SDS, thus expressing stronger synergism. In SDS-Tween 80 binary system the strongest synergistic effect was noticed. SDS-Tween 85 micellar system showed antagonistic effect, most probably because the presence of the double bond in its three hydrophobic tails (three C18 tails makes it sterically rigid.

  5. Study of nucleic acid-gold nanorod interactions and detecting nucleic acid hybridization using gold nanorod solutions in the presence of sodium citrate.

    Science.gov (United States)

    Kanjanawarut, Roejarek; Su, Xiaodi

    2010-09-01

    In this study, the authors report that sodium citrate can aggregate hexadecyl-trimethyl-ammonium ion(+)-coated gold nanorods (AuNRs), and nucleic acids of different charge and structure properties, i.e., single-stranded DNA (ssDNA), double-stranded DNA (dsDNA), single-stranded peptide nucleic acid (PNA), and PNA-DNA complex, can bind to the AuNRs and therefore retard the sodium citrate-induced aggregation to different extents. The discovery that hybridized dsDNA (and the PNA-DNA complex) has a more pronounced protection effect than ssDNA (and PNA) allows the authors to develop a homogeneous phase AuNRs-based UV-visible (UV-vis) spectral assay for detecting specific sequences of oligonucleotides (20 mer) with a single-base-mismatch selectivity and a limit of detection of 5 nM. This assay involves no tedious bioconjugation and on-particle hybridization. The simple "set and test" format allows for a highly efficient hybridization in a homogeneous phase and a rapid display of the results in less than a minute. By measuring the degree of reduction in AuNR aggregation in the presence of different nucleic acid samples, one can assess how different nucleic acids interact with the AuNRs to complement the knowledge of spherical gold nanoparticles. Besides UV-vis characterization, transmission electron microscopy and zeta potential measurements were conduced to provide visual evidence of the particle aggregation and to support the discussion of the assay principle.

  6. Test Your Sodium Smarts

    Science.gov (United States)

    ... You may be surprised to learn how much sodium is in many foods. Sodium, including sodium chloride ... foods with little or no salt. Test your sodium smarts by answering these 10 questions about which ...

  7. The Zintl-Klemm concept applied to cations in oxides. I. The structures of ternary aluminates.

    Science.gov (United States)

    Santamaría-Pérez, David; Vegas, Angel

    2003-06-01

    The structures of 94 ternary aluminates are reinterpreted on the basis of the Zintl-Klemm concept and Pearson's generalized octet rule. In aluminates of highly electropositive metals such as alkali, alkaline-earth and rare-earth metals, the Al atoms form three-dimensional skeleta which can be interpreted as if the Al atoms were behaving as Zintl polyanions, adopting the structure of either main-group elements or Zintl polyanions showing the same connectivity. The O atoms are then located close to both the hypothetical two-electron bonds and the lone pairs, giving rise to a tetrahedral coordination. When more electronegative elements, such as W or Si, are present in the compound, the electron transfer towards the Al atoms does not take place. In this case, aluminium behaves as a base, transferring its electrons to the more electronegative atoms and the coordination sphere of aluminium becomes octahedral. In some compounds the Al atoms clearly show amphoteric character so that some Al atoms act as donors (bases) and hence are octahedrally coordinated, whereas others behave as acceptors (acids), adopting a tetrahedral coordination. From this it is concluded that the coordination sphere of aluminium is not a function of the ionic radius of the Al(3+) cations, but it depends on the nature of the other cations accompanying them in the structure. The networks formed by these aluminates are, in many instances, similar to those of the binary oxides of the main-group elements. For this reason, a systematic survey of these oxides is also reported. Compounds such as stuffed cristobalites and trydimites and also perovskites are examples of this new interpretation. Perovskites are then reinterpreted as a stuffed pseudo-TeO(3) structure. Other families of compounds such as silicates and phosphates are susceptible to a similar interpretation. This study provides additional examples of how cations recognize themselves in spite of being embedded in an oxygen matrix.

  8. Calcium Hex aluminate reaction sintering by Spark Plasma Sintering; Sinterizacion reactiva de Hexaluminato de Calcio mediante Spark Plasma Sintering

    Energy Technology Data Exchange (ETDEWEB)

    Iglesia, P. G. de la; Garcia-Moreno, O.; Torrecillas, R.; Menendez, J. L.

    2012-11-01

    Calcium hex aluminate (CaAl{sub 1}2O{sub 1}9) is the most alumina-rich intermediate compound of the CaO-Al{sub 2}O{sub 3} system. The formation of this aluminate is produced by the reaction between calcium oxide and alumina with the consequent formation of intermediates compounds with lower alumina content with increasing temperature (CaAl{sub 2}O{sub 4}, CaAl4O{sub 7}). In this study we studied the variation of sintering parameters for obtaining dense and pure calcium hex aluminate by reaction sintering by Spark Plasma Sintering (SPS). A mixing of Al{sub 2}O{sub 3} and CaCO{sub 3} were used as reactive. Final densities close to the theoretical and phase transformation over 93% were achieved by this method. (Author) 22 refs.

  9. Methods of use of calcium hexa aluminate refractory linings and/or chemical barriers in high alkali or alkaline environments

    Science.gov (United States)

    McGowan, Kenneth A; Cullen, Robert M; Keiser, James R; Hemrick, James G; Meisner, Roberta A

    2013-10-22

    A method for improving the insulating character/and or penetration resistance of a liner in contact with at least one of an alkali and/or alkaline environments is provided. The method comprises lining a surface that is subject to wear by an alkali environment and/or an alkaline environment with a refractory composition comprising a refractory aggregate consisting essentially of a calcium hexa aluminate clinker having the formula CA.sub.6, wherein C is equal to calcium oxide, wherein A is equal to aluminum oxide, and wherein the hexa aluminate clinker has from zero to less than about fifty weight percent C.sub.12A.sub.7, and wherein greater than 98 weight percent of the calcium hexa aluminate clinker having a particle size ranging from -20 microns to +3 millimeters, for forming a liner of the surface. This method improves the insulating character/and or penetration resistance of the liner.

  10. Poly(pyrazolyl)aluminate complexes containing aluminum-hydrogen bonds.

    Science.gov (United States)

    Snyder, Christopher J; Heeg, Mary Jane; Winter, Charles H

    2011-10-03

    The treatment of LiAlH(4) with 2, 3, or 4 equiv of the 3,5-disubstituted pyrazoles Ph(2)pzH or iPr(2)pzH afforded [Li(THF)(2)][AlH(2)(Ph(2)pz)(2)] (97%), [Li(THF)][AlH(Ph(2)pz)(3)] (96%), [Li(THF)(4)][Al(Ph(2)pz)(4)] (95%), and [Li(THF)][AlH(iPr(2)pz)(3)] (89%). The treatment of ZnCl(2) with [Li(THF)][AlH(Ph(2)pz)(3)] afforded Zn(AlH(Ph(2)Pz)(3))H (70%). X-ray crystal structures of these complexes demonstrated κ(2) or κ(3) coordination of the aluminum-based ligands to the Li or Zn ions. The treatment of [Li(THF)][AlH(Ph(2)pz)(3)] with MgBr(2) or CoCl(2) in THF/Et(2)O solutions, by contrast, afforded the pyrazolate transfer products Mg(2)Br(2)(Ph(2)pz)(2)(THF)(3)·2THF (25%) and Co(2)Cl(2)(Ph(2)pz)(2)(THF)(3)·THF (23%) as colorless and blue crystalline solids, respectively. An analogous treatment of [Li(THF)][AlH(Ph(2)pz)(3)] with MCl(2) (M = Mn, Fe, Ni, Cu) afforded metal powders and H(2), illustrating hydride transfer from Al to M as a competing reaction path.

  11. Effect of X-Rays on the Mechanical Properties of Aluminized FEP Teflon(R)

    Science.gov (United States)

    Gaier, James R.; Brinkmeier, Michael R.; Gaier, Elizabeth M.

    1998-01-01

    Pieces of the multilayer insulation (MLI) that is integral to the thermal control of the Hubble Space Telescope (HST) have been returned by two servicing missions after 3.6 and 6.8 years in orbit. They reveal that the outer layer, which is made from 5 mil (0.13 mm)thick aluminized fluorinated ethylene propylene(FEP) Teflon(R), has become severely embrittled. Although possible agents of this embrittlement include electromagnetic radiation across the entire solar spectrum, trapped particle radiation, atomic oxygen, and thermal cycling, intensive investigations have not yielded unambiguous causes. Previous studies utilizing monoenergetic photons in the 69-1900 eV range did not cause significant embrittlement, even at much higher doses than were experienced by the HST MLI. Neither did x-rays in the 3 to 10 keV range generated in a modified electron beam evaporator. An antidotal aluminized FEP sample that was exposed to an intensive dose from unfiltered Mo x-ray radiation from a rotating anode generator, however, did show the requisite embrittlement. Thus, a study was undertaken to determine the effects of x-ray exposure on the embrittlement of aluminized FEP in hopes that it might elucidate the HST MLI degradation mechanism. Tensile specimens of aluminized 5 mil thick FEP were exposed to a constant fluence of unfiltered x-ray radiation from a Mo target whose maximum energy ranged from 20-60 kV. Other samples were annealed, thermally cycled (100x) between 77-333 K, or cycled and irradiated. Tensile tests and density measurements were then performed on the samples. Only the samples which had been irradiated had the drastically reduced elongation-to-break, characteristic of the HST samples. Thermal cycling may accelerate the embrittlement, but the effect was near the scatter in the measurements. Annealing and thermal cycling had no apparent effect. Only the samples which had been irradiated and annealed showed significant density increases, likely implicating polymer

  12. Evaluation of Bayer process gibbsite reactivity in magnesium aluminate spinel formation

    International Nuclear Information System (INIS)

    Mora, A.; Gutierrez-Campos, D.; Lavelle, C.; Rodriguez, R.M.

    2007-01-01

    Stoichiometric magnesium aluminate spinel was synthesized by solid-state reaction of calcined magnesia with tabular alumina, calcined alumina and industrial gibbsite at 1100, 1300 and 1500 deg. C for 2 h. The pellets made from both types of alumina and magnesia expanded after the heat treatment, whereas pellets made from industrial gibbsite and magnesia contracted. It was found that shrinkage could be produced by phase transformations in gibbsite and magnesia densification process in unreacted magnesia during the sintering. The X-ray diffraction patterns indicated a minor reactivity for industrial gibbsite in comparison with the calcined alumina and tabular alumina at all firing temperatures

  13. Method of growing yttrium aluminate and/or lanthanide single crystals with perovskite structure

    International Nuclear Information System (INIS)

    Kvapil, Jiri; Perner, B.; Kvapil, Josef; Blazek, K.

    1989-01-01

    Single crystals of yttrium aluminate and/or lanthanide with perovskite structure are grown from melt in a vacuum at a pressure of gas residues of max. 0.01 Pa. The melt contains 1±0.05 gram-ions of aluminium per gram-ion of yttrium and/or lanthanides. The single crystals are then heated in a vacuum (0.01 Pa) at temperatures of 1,450 to 1,800 degC for 2 to 3 hours. (B.S.)

  14. The effect of Y2O3 addition on thermal shock behavior of magnesium aluminate spinel

    Directory of Open Access Journals (Sweden)

    Pošarac Milica

    2009-01-01

    Full Text Available The effect of yttria additive on the thermal shock behavior of magnesium aluminate spinel has been investigated. As a starting material we used spinel (MgAl2O4 obtained by the modified glycine nitrate procedure (MGNP. Sintered products were characterized in terms of phase analysis, densities, thermal shock, monitoring the damaged surface area in the refractory specimen during thermal shock and ultrasonic determination of the Dynamic Young modulus of elasticity. It was found that a new phase between yttria and alumina is formed, which improved thermal shock properties of the spinel refractories. Also densification of samples is enhanced by yttria addition.

  15. Metamorphic history and age of aluminous gneisses of the Belomorian belt of the Baltic shield

    International Nuclear Information System (INIS)

    Bibikova, E.V.; Borisova, E.Yu.; Makarov, V.A.; Drugova, G.M.

    1997-01-01

    Metamorphic conditions and age are determined for the early metamorphic stage of aluminous gneisses in the Chupa nappe in the Belomorian Mobile Belt. The granulite-facies metamorphic conditions during Late Archean time are determined based on the composition of garnet and biotie from the metapelites. The early metamorphic stage was dated at 2860 ± 30 Ma based on the U-Pb systematics of granulitic zircon from the metapelites. The U-Pb isotopic system of the zircon was strongly affected by Svecogennian metamorphism (at 1750 Ma). The geodynamic evolution of the Belomorian Mobile Belt is discussed in light of the data of this work

  16. Evaluation of Bayer process gibbsite reactivity in magnesium aluminate spinel formation

    Energy Technology Data Exchange (ETDEWEB)

    Mora, A. [Department of Materials Science, Universidad Simon Bolivar, Caracas 1080-A (Venezuela)], E-mail: abrahanmora@hotmail.com; Gutierrez-Campos, D. [Department of Materials Science, Universidad Simon Bolivar, Caracas 1080-A (Venezuela)], E-mail: dgutierr@usb.ve; Lavelle, C. [Department of Materials Science, Universidad Simon Bolivar, Caracas 1080-A (Venezuela)], E-mail: clavelle@wanadoo.fr; Rodriguez, R.M. [Department of Chemistry, Universidad Metropolitana, Edif. Corimon, Terrazas del Avila, Distribuidor Autopista, Dto. Sucre, Caracas 1070 (Venezuela)], E-mail: rrodriguez@unimet.edu.ve

    2007-04-25

    Stoichiometric magnesium aluminate spinel was synthesized by solid-state reaction of calcined magnesia with tabular alumina, calcined alumina and industrial gibbsite at 1100, 1300 and 1500 deg. C for 2 h. The pellets made from both types of alumina and magnesia expanded after the heat treatment, whereas pellets made from industrial gibbsite and magnesia contracted. It was found that shrinkage could be produced by phase transformations in gibbsite and magnesia densification process in unreacted magnesia during the sintering. The X-ray diffraction patterns indicated a minor reactivity for industrial gibbsite in comparison with the calcined alumina and tabular alumina at all firing temperatures.

  17. A method for the manufacture of nuclear-purity sodium

    International Nuclear Information System (INIS)

    Besson, Paul; Graff, Willy.

    1973-01-01

    Description is given of a method for the manufacture of sodium from the amalgam provided by sodium chloride aqueous electrolysis cells, comprising the steps of treating the sodium amalgam by a sodium polysulfide or a mixture of sodium polysulfide in anhydrous alcohol solution, then causing the thus obtained sodium monosulfide to react with a polysulfide or a mixture of polysulfides so as to obtain a mixture of sodium polysulfides with a higher sodium content, and finally separating sodium through the electrolysis of the sodium-rich polysulfides, the electrolysis being carried out in an electrolytic cell with β-alumina solid electrolyte operating at a temperature between 250 and 300 deg C, in which the polysulfide forms the anode compartment and sodium the cathode compartment [fr

  18. Criterion for selection the optimal physical and chemical properties of cobalt aluminate powder used in investment casting process

    OpenAIRE

    M. Zielińska; J. Sieniawski; B. Gajecka

    2009-01-01

    The aim of this work was to determine physical and chemical properties of cobalt aluminate (CoAl2O4) modifiers produced by different companies and the influence of different types of modifiers on the grain size of high temperature creep resisting superalloys: Inconel 713C, René 77 and MAR-M 509.The first stage of the research work took over the investigations of physical and chemical properties of cobalt aluminate manufactured by three different companies: Remet, Mason Color and Permedia Lubl...

  19. Post-processing application of chemical solutions for control of Listeria monocytogenes, cultured under different conditions, on commercial smoked sausage formulated with and without potassium lactate-sodium diacetate.

    Science.gov (United States)

    Geornaras, Ifigenia; Skandamis, Panagiotis N; Belk, Keith E; Scanga, John A; Kendall, Patricia A; Smith, Gary C; Sofos, John N

    2006-12-01

    This study evaluated post-processing chemical solutions for their antilisterial effects on commercial smoked sausage formulated with or without 1.5% potassium lactate plus 0.05% sodium diacetate, and contaminated (approximately 3-4 log cfu/cm(2)) with 10-strain composite Listeria monocytogenes inocula prepared under various conditions. Inoculated samples were left untreated, or were immersed (2 min, 25 +/- 2 degrees C) in solutions of acetic acid (2.5%), lactic acid (2.5%), potassium benzoate (5%) or Nisaplin (0.5%, equivalent to 5000 IU/ml of nisin) alone, and in sequence (Nisaplin followed by acetic acid, lactic acid or potassium benzoate), before vacuum packaging and storage at 10 degrees C (48 days). Acetic acid, lactic acid or potassium benzoate applied alone reduced initial L. monocytogenes populations by 0.4-1.5 log cfu/cm(2), while treatments including Nisaplin caused reductions of 2.1-3.3 log cfu/cm(2). L. monocytogenes on untreated sausage formulated with antimicrobials had a lag phase duration of 10.2 days and maximum specific growth rate (mu(max)) of 0.089 per day, compared to no lag phase and mu(max) of 0.300 per day for L. monocytogenes on untreated product that did not contain antimicrobials in the formulation. The immersion treatments inhibited growth of the pathogen for 4.9-14.8 days on sausage formulated without potassium lactate-sodium diacetate; however, in all cases significant (P meat processors in their efforts to select required regulatory alternatives for control of post-processing contamination in meat products.

  20. Diluting ferric carboxymaltose in sodium chloride infusion solution (0.9% w/v) in polypropylene bottles and bags: effects on chemical stability.

    Science.gov (United States)

    Philipp, Erik; Braitsch, Michaela; Bichsel, Tobias; Mühlebach, Stefan

    2016-01-01

    This study was designed to assess the physicochemical stability of colloidal ferric carboxymaltose solution (Ferinject) when diluted and stored in polypropylene (PP) bottles and bags for infusion. Two batches of ferric carboxymaltose solution (Ferinject) were diluted (500 mg, 200 mg and 100 mg iron in 100 mL saline) in PP bottles or bags under aseptic conditions. The diluted solutions were stored at 30°C and 75%±5% relative humidity (rH) for 72 h, and samples were withdrawn aseptically at preparation and after 24 h, 48 h and 72 h. Multiple parameters were used to test stability-related measures (pH, total iron and iron (II) content, molecular weight range determination, microbial contamination and particles count ≥10 μm). Overall, Ferinject diluted in 0.9% (w/v) NaCl solution and stored in PP bottles and bags was stable within the specifications for the complex and the acceptability limits set for all assays. In both containers, total iron content remained stable, within 10% of the theoretical iron content, and levels of iron (II) remained far below the threshold of acceptability. All preparations were free from sediments, particle numbers were acceptable and there was no microbial contamination. The molecular weight distribution and polydispersity index were also acceptable. Under the tested experimental conditions, colloidal ferric carboxymaltose solution (Ferinject) diluted in saline in PP infusion bottles or bags demonstrated physical and chemical stability for up to 72 h at 30°C and 75% rH. Because of the lack of additional clinical data, when using ferric carboxymaltose, physicians/pharmacists should refer to the dilution and storing recommendations given in the product's summary of product characteristics.

  1. Constants and thermodynamics of the acid-base equilibria of triglycine in water-ethanol solutions containing sodium perchlorate at 298 K

    Science.gov (United States)

    Pham Tkhi, L.; Usacheva, T. R.; Tukumova, N. V.; Koryshev, N. E.; Khrenova, T. M.; Sharnin, V. A.

    2016-02-01

    The acid-base equilibrium constants for glycyl-glycyl-glycine (triglycine) in water-ethanol solvents containing 0.0, 0.1, 0.3, and 0.5 mole fractions of ethanol are determined by potentiometric titration at 298.15 K and an ionic strength of 0.1, maintained with sodium perchlorate. It is established that an increase in the ethanol content in the solvent reduces the dissociation constant of the carboxyl group of triglycine (increases p K 1) and increases the dissociation constant of the amino group of triglycine (decreases p K 2). It is noted that the weakening of the acidic properties of a triglycinium ion upon an increase of the ethanol content in the solvent is due to the attenuation of the solvation shell of the zwitterionic form of triglycine, and to the increased solvation of triglycinium ions. It is concluded that the acid strength of triglycine increases along with a rise in the EtOH content in the solvent, due to the desolvation of the tripeptide zwitterion and the enhanced solvation of protons.

  2. Quenchable water-rich, aluminous post-stishovite: implications for seismic anomalies in the mid-mantle

    Science.gov (United States)

    Myhill, R.; Frost, D. J.; Panero, W. R.; Boffa Ballaran, T.; Miyajima, N.; Bureau, H.; Raepsaet, C.; Siersch, N.; Kohn, S. C.

    2016-12-01

    At mid-mantle pressures, stishovite undergoes a displacive phase transition to the calcium chloride structure. It has been argued that softening accompanying this phase transition leads to very low seismic velocities and that silica-rich materials in the lower mantle may therefore be effective scatterers of seismic energy. The post-stishovite phase is also a promising candidate for water storage in the lower mantle, as it is both stable at very high temperatures and isostructural with the high pressure hydrous phases delta-AlOOH and Phase H. Pure SiO2 post-stishovite is unquenchable, making ex-situ characterisation impossible. In this study, we exploit the stabilisation of the post-stishovite structure due to alumina incorporation to synthesise and quench large crystals of post-stishovite. Single crystals are characterised by X-ray diffraction, TEM and Raman spectroscopy, and water contents are analysed with elastic recoil detection and FTIR. We show that water contents in our post-stishovite crystals are consistent with an SiO2-AlOOH solid solution, containing 3-7 times more water per atom of aluminium than stishovite. Our results suggest that almost 1 wt % H2O could be incorporated into post-stishovite crystals in lower mantle mafic rocks. We use ab-initio simulations to investigate the effect of pressure on the mechanism of hydroxyl incorporation into aluminous stishovite and post-stishovite. Finally, we discuss the potential for post-stishovite to affect seismic velocities in the lower mantle. In addition to the scattering potential of the phase transition, patchy low velocity layers in the mid-mantle might represent regions where hydrous melts are reacting with post-stishovite. In the lowermost mantle, transformation of post-stishovite to seifertite could result in the formation of a hydrous melt that might explain seismologically observed ultra low velocity zones.

  3. Studies on the influence of metallurgical variables on the stress corrosion behavior of aisi 304 stainless steel in sodium chloride solution using the fracture mechanics approach

    Science.gov (United States)

    Khatak, H. S.; Gnanamoorthy, J. B.; Rodriguez, P.

    1996-05-01

    Stress corrosion data on a nuclear grade AISI type 304 stainless steel in a boiling solution of 5M NaCl+ 0.15M Na2SO4+ 3 mL/L HC1 (bp 381 K) for various metallurgical conditions of the steel are presented in this article. The metallurgical conditions used are solution annealing, sensitization, 10 pct cold work, 20 pct cold work, solution annealing + sensitization, 10 pct cold work + sensi-tization, and 20 pct cold work + sensitization. The fracture mechanics approach has been used to obtain quantitative data on the stress corrosion crack growth rates. The stress intensity factor, K 1, and J integral, J 1, have been used as evaluation parameters. The crack growth rates have been measured using compact tension type samples under both increasing and decreasing stress intensity factors. A crack growth rate of 5 X 10-11 m/s was chosen for the determination of threshold para-meters. Results of the optical microscopic and fractographic examinations are presented. Acoustic signals were recorded during crack growth. Data generated from acoustic emissions, activation energy measurements, and fractographic features indicate hydrogen embrittlement as the possible mechanism of cracking.

  4. Dynamic Mechanical Properties and Constitutive Relation of an Aluminized Polymer Bonded Explosive at Low Temperatures

    Directory of Open Access Journals (Sweden)

    Yuliang Lin

    2014-01-01

    Full Text Available Polymer bonded explosives (PBXs are widely used as energetic fillings in various warheads, which maybe are utilized under extreme environments, such as low or high temperatures. In this paper, the dynamic response of an aluminized polymer bonded explosive was tested at a range of temperatures from −55°C to −2°C and a fixed loading strain rate (~700 s−1 with the split Hopkinson pressure bar (SHPB. The PBX tested is aluminized, which contains 76 wt% RDX, 20 wt% aluminum powder, and 4 wt% polymer binder, respectively. The results show that the effect of temperature on the strength of the PBX is obvious at the tested strain rates. Based on the experimental results and prophase studies, a constitutive model was obtained, in which the effect of temperature and strain rate were considered. The modeling curves fit well with the experimental results, not only at low temperature under 0°C, but also at room temperature (20°C. The model may be used to predict the dynamic performances of the PBXs in various environments.

  5. Effect Of Heat Treatment On The Corrosion Resistance Of Aluminized Steel Strips

    Directory of Open Access Journals (Sweden)

    Żaba K.

    2015-09-01

    Full Text Available The paper presents the results of corrosion resistance of heat treated aluminized steel strips. Products coated by Al-10Si alloy are used among others in a manufacturing process of welded pipes as the elements of the car exhaust systems, working in high temperatures and different environments (eg. wet, salty. The strips and tubes high performance requirements are applied to stability, thickness and roughness of Al-Si coating, adhesion and corrosion resistance. Tubes working in elements of exhaust systems in a wide range of temperatures are exposed to the effects of many aggressive factors, such as salty snow mud. It was therefore decided to carry out research on the impact of corrosion on the environmental influence on heat treated aluminized steel strips. The heat treatment was carried out temperatures in the range 250-700°C for 30, 180, 1440 minutes. Then the coatings was subjected to cyclic impact of snow mud. Total duration of treatment was 12 months and it was divided into three stages of four months and at the end of each stage was made the assessment of factor of corrosion. The results are presented in the form of macroscopic, microscopic (using a scanning electron microscope observations and the degree and type of rusty coating.

  6. Using Underwater Explosion and Cylinder Expansion Tests to Calibrate Afterburn Models for Aluminized Explosives

    Science.gov (United States)

    Wedberg, Rasmus

    2017-06-01

    The study explores the combined use of underwater performance tests and cylinder expansion tests in order to parameterize detonation models for aluminized explosives which exhibit afterburning. The approach is suggested to be used in conjunction with thermochemical computation. A formulation containing RDX and aluminum powder is considered and several charges with varying masses are submerged and detonated. Pressure gauges are employed at horizontal distances scaling with the charge diameter, and the specific shock wave energy is shown to increase with charge mass. This is attributed to the combustion of aluminum particles after the Chapman-Jouguet plane. Cylinder expansion tests are carried out using Photon Doppler Velocimetry to register the wall expansion velocity. The tests are modeled using a multi-material arbitrary Lagrangian-Eulerian approach with the Guirguis-Miller model describing detonation with afterburning. The equation of state and afterburn rate law parameters are adjusted such that the model reproduces the results from the cylinder expansion and underwater tests. The approach seems promising, and might be valuable for aluminized explosive formulations intended to be used in a variety of confinement conditions. Swedish Armed Forces.

  7. A two-phase model for aluminized explosives on the ballistic and brisance performance

    Science.gov (United States)

    Kim, Wuhyun; Gwak, Min-cheol; Lee, Young-hun; Yoh, Jack J.

    2018-02-01

    The performance of aluminized high explosives is considered by varying the aluminum (Al) mass fraction in a heterogeneous mixture model. Since the time scales of the characteristic induction and combustion of high explosives and Al particles differ, the process of energy release behind the leading detonation wave front occurs over an extended period of time. For simulating the performance of aluminized explosives with varying Al mass fraction, HMX (1,3,5,7-tetrahexmine-1,3,5,7-tetrazocane) is considered as a base explosive when formulating the multiphase conservation laws of mass, momentum, and energy exchanges between the HMX product gases and Al particles. In the current study, a two-phase model is utilized in order to determine the effects of the Al mass fraction in a condensed phase explosive. First, two types of confined rate stick tests are considered to investigate the detonation velocity and the acceleration ability, which refers to the radial expansion velocity of the confinement shell. The simulation results of the confined rate stick test are compared with the experimental data for the Al mass fraction range of 0%-25%, and the optimal Al mass fraction is provided, which is consistent with the experimental observations. Additionally, a series of plate dent test simulations are conducted, the results of which show the same tendency as those of the experimental tests with varying Al mass fractions.

  8. Thermodynamics of self-assembling of mixture of a cationic gemini surfactant and sodium dodecylsulfate in aqueous solution: Calorimetry, conductivity and surface pressure measurements

    International Nuclear Information System (INIS)

    Bai, Guangyue; Wang, Yujie; Ding, Yanhong; Zhuo, Kelei; Wang, Jianji; Bastos, Margarida

    2016-01-01

    Highlights: • ITC provided thermodynamic characterization of self-association of oppositely charged gemini/SDS surfactants. • Phase transitions and corresponding enthalpies were obtained by ITC. • The transitions reflect a change in morphology, supported by Cryo-TEM images. • Conductivity and ITC results show very good agreement. • An asymmetric distribution of surfactants in the aggregates is supported by results. - Abstract: The thermodynamics and phase behavior of mixtures of cationic gemini surfactant decanediyl-α,ω-bis(dodecyldimethylammonium bromide) (12-10-12) and sodium dodecylsulfate (SDS) were studied in the dilute SDS-rich region. The enthalpy of interaction between both surfactant monomers before the critical micelle concentration for the mixture (cmc mix ) was determined by isothermal titration calorimetry (ITC). After the cmc mix , ITC results exhibited a first process associated with a large endothermic enthalpy change followed by a second one with a very small exothermic enthalpy change. In the same regions, the conductivity curves show an increase in slope after the break, followed by a plateau region, respectively for the two processes. The combined results from the various methodologies used lead us to propose that the first process reflects the formation of non-spherical micelles and the second one the vesicle formation. The area per catanionic complex was obtained through surface pressure measurements, leading to an apparent packing parameter ⩾1. The observed behavior may be rationalized on the basis of the hypothesis that both surfactants distribute asymmetrically in the vesicle bilayers and unevenly in the non-spherical micelle. In order to get structural information Cryo-TEM experiments were performed, which provided images that support this interpretation. From all the information gathered a phase diagram was mapped, including three one-phase regions of spherical micelles, non-spherical micelles and vesicles.

  9. High-Performance Na0.44MnO2 Slabs for Sodium-Ion Batteries Obtained through Urea-Based Solution Combustion Synthesis

    Directory of Open Access Journals (Sweden)

    Chiara Ferrara

    2018-02-01

    Full Text Available One of the primary targets of current research in the field of energy storage and conversion is the identification of easy, low-cost approaches for synthesizing cell active materials. Herein, we present a novel method for preparing nanometric slabs of Na0.44MnO2, making use of the eco-friendly urea within a solution synthesis approach. This kind of preparation greatly reduces the time of reaction, decreases the thermal treatment temperature, and allows the obtaining of particles with smaller dimensions compared with those obtained through conventional solid-state synthesis. Such a decrease in particle size guarantees improved electrochemical performance, particularly at high current densities, where kinetic limitations become relevant. Indeed, the materials produced via solution synthesis outperform those prepared via solid-state synthesis both at 2 C, (95 mA h g−1 vs. 85 mA h g−1, respectively and 5 C, (78 mA h g−1 vs. 68.5 mA h g−1, respectively. Additionally, the former material is rather stable over 200 cycles, with a high capacity retention of 75.7%.

  10. Hydration process for calcium-aluminate cement within EVA emulsion by SPring-8 synchrotron radiation x-ray diffraction method

    International Nuclear Information System (INIS)

    Kotera, Masaru; Matsuda, Ikuyo; Miyashita, Keiko; Adachi, Nobuyuki; Tamura, Hisayuki

    2005-01-01

    Polymer-modified mortars which consist of a polymer emulsion and cement materials have been widely developed in the construction materials fields. Forming process of the polymer-modified cement membrane simultaneously involves evaporation of water within the polymer emulsion and hydration of cement. It is important for the polymer-modified cement paste that the hydrate crystal of cement is generating by the hydration during the setting process under existence of the polymer emulsion. In this study, hydration process for calcium-aluminate cement under existence of poly (ethylene-vinyl acetate) (EVA) emulsion (polymer-cement ratio=100%) was investigated by X-ray diffraction method using synchrotron radiation (SPring-8). The diffraction peaks of calcium aluminate (CA) disappeared after the hardening, on the other hand, the peaks of hydrate crystals of calcium-aluminate cement (C 2 AH 8 and C 3 AH 6 ) could be observed. This polymer-modified cement paste hydrated using the water within the polymer emulsion. The hydration of C 2 AH 8 from CA started at around 300 min, and then C 3 AH 6 hydrate crystal increased after 700 min at ambient temperature. This implies that the conversion from C 2 AH 8 to C 3 AH 6 occurred to be more stable phase. The setting temperature affected the reaction rate. In case of hydration at 35degC, the start time of the hydration for calcium-aluminate cement was quicker than that in the ambient temperature four or more times. (author)

  11. Investigation of barium-calcium aluminate process to manufacture and characterize impregnated thermionic cathode for power microwave devices

    International Nuclear Information System (INIS)

    Higashi, Cristiane

    2006-01-01

    In the present work it is described the barium calcium aluminate manufacture processes employed to produce impregnated cathodes to be used in a traveling-wave tube (TWT). The cathodes were developed using a tungsten body impregnated with barium and calcium aluminate with a 5:3:2 proportion (molar). Three different processes were investigated to obtain this material: solid-state reaction, precipitation and crystallization. Thermal analysis, thermogravimetry specifically, supported to determine an adequate preparation procedure (taking into account temperature, time and pyrolysis atmosphere). It was verified that the crystallization showed a better result when compared to those investigated (solid-state reaction and precipitation techniques - formation temperature is about 1000 deg C in hydrogen atmosphere), whereas it presented the lower formation temperature (800 deg C) in oxidizing atmosphere (O 2 ). It was used the practical work function distribution theory (PWFD) of Miram to characterize thermionic impregnated cathode. The PWFD curves were used to characterize the barium-calcium aluminate cathode. PWFD curves shown that the aluminate cathode work function is about 2,00 eV. (author)

  12. Physical and Mechanical Properties of Composites Made with Aluminous Cement and Basalt Fibers Developed for High Temperature Application

    Directory of Open Access Journals (Sweden)

    Pavel Reiterman

    2015-01-01

    Full Text Available Present paper deals with the experimental study of the composition of refractory fiber-reinforced aluminous cement based composites and its response to gradual thermal loading. Basalt fibers were applied in doses of 0.25, 0.5, 1.0, 2.0, and 4.0% in volume. Simultaneously, binder system based on the aluminous cement was modified by fine ground ceramic powder originated from the accurate ceramic blocks production. Ceramic powder was dosed as partial replacement of used cement of 5, 10, 15, 20, and 25%. Influence of composition changes was evaluated by the results of physical and mechanical testing; compressive strength, flexural strength, bulk density, and fracture energy were determined on the different levels of temperature loading. Increased dose of basalt fibers allows reaching expected higher values of fracture energy, but with respect to results of compressive and flexural strength determination as an optimal rate of basalt fibers dose was considered 0.25% in volume. Fine ground ceramic powder application led to extensive increase of residual mechanical parameters just up to replacement of 10%. Higher replacement of aluminous cement reduced final values of bulk density but kept mechanical properties on the level of mixtures without aluminous cement replacement.

  13. Effective adsorption of sodium dodecylsulfate (SDS) by hydrocalumite (CaAl-LDH-Cl) induced by self-dissolution and re-precipitation mechanism.

    Science.gov (United States)

    Zhang, Ping; Qian, Guangren; Xu, Zhi Ping; Shi, Huisheng; Ruan, Xiuxiu; Yang, Jing; Frost, Ray L

    2012-02-01

    Hydrocalumite (CaAl-LDH-Cl) was synthesized through a rehydration method involving a freshly prepared tricalcium aluminate (C(3)A) with CaCl(2) solution. To understand the intercalation behavior of sodium dodecylsulfate (SDS) with CaAl-LDH-Cl, X-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscopy (SEM), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), inductively coupled plasma-atomic emission spectrometer (ICP), and elemental analysis have been undertaken. The sorption isotherms with SDS reveal that the maximum sorption amount of SDS by CaAl-LDH-Cl could reach 3.67 mmol g(-1). The results revealed that CaAl-LDH-Cl holds a self-dissolution property, about 20-30% of which is dissolved. And the dissolved Ca(2+) and Al(3+) ions are combined with SDS to form CaAl-SDS or Ca-SDS precipitation. It has been highlighted that the composition of resulting products is strongly dependent upon the SDS concentration. With increasing SDS concentrations, the main resulting product changes from CaAl-SDS to Ca-SDS, and the value of interlayer spacing increased to 3.27 nm. Copyright © 2011 Elsevier Inc. All rights reserved.

  14. The effectiveness of the biannual application of silver nitrate solution followed by sodium fluoride varnish in arresting early childhood caries in preschool children: study protocol for a randomised controlled trial.

    Science.gov (United States)

    Chu, Chun-Hung; Gao, Sherry Shiqian; Li, Samantha Ky; Wong, May Cm; Lo, Edward Cm

    2015-09-25

    The application of 38 % silver diamine fluoride (SDF) has been shown to be effective in arresting early childhood caries (ECC). Since SDF is not available in certain countries, some dentists use adjunctive application of 25 % silver nitrate (AgNO3) and 5 % sodium fluoride (NaF) to arrest ECC. This randomised controlled trial will systematically compare the efficacy of a 25 % AgNO3 solution followed by 5 % NaF varnish with that of a 38 % SDF solution in arresting ECC when applied at half-yearly intervals over a 30-month period. This study is a randomised, double-blinded, non-inferiority clinical trial. The hypothesis tested is that adjunctive application of 25 % AgNO3 followed by 5 % NaF is at least not appreciably worse than a 38 % SDF in arresting ECC. Approximately 3100 kindergarten children aged 3-4 years will be screened and at least 1070 children with caries will be recruited. This sample size is sufficient for an appropriate statistical analysis (power at 90 % (β = 0.10) with a 2-sided type-I error of α = 0.05), allowing for an overall 20 % drop-out rate. The children will be randomly allocated into 2 groups to treat their caries over a 30-month period: Group A - biannual adjunctive application of a 25 % AgNO3 solution and a 5 % NaF varnish, and Group B - biannual adjunctive application of a 38 % SDF solution followed by a placebo varnish. Clinical examinations will be conducted at 6-month intervals. Primary outcome measured is the number of active caries surfaces which are arrested. Information on confounding factors such as oral hygiene habits will be collected through a parental questionnaire. We expect that adjunctive application of 25 % AgNO3 solution and 5 % NaF varnish and of 38 % SDF solution can both effectively arrest ECC. Lower concentrations of silver and fluoride are contained in 25 % AgNO3 and 5 % NaF, respectively, than in 38 % SDF; therefore, AgNO3/NaF are more favourable for use in young children. Because its use for caries management is

  15. To Compare the Effects of Storage Solutions 0.05% Thymol vs. 6% Sodium Hypochlorite vs. Hank’s Balanced Salt Solution on the Flexural Strength of Dentin Bars

    Science.gov (United States)

    2016-05-20

    generalized to teeth in vivo. If extracted teeth are to be treated as valid proxies of teeth in vivo, it is critical to understand the effect of...as Young’s modulus and yield stress. (Aydin B, 2015) For in vitro measures such as flexural strength to be considered valid proxies of in vivo...The solution is commonly used to preserve periodontal ligament cells on a tooth that has been avulsed from the patient’s mouth (Aydin, 2015). The

  16. Hydrogen embrittlement of type 410 stainless steel in sodium chloride, sodium sulfate, and sodium hydroxide environments at 90 C

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Rodriguez, J.G.; Salinas-Bravo, V.M. [Inst. de Investigaciones Electricas, Cuernavaca (Mexico). Dept. Fisico Quimica Aplicada; Martinez-Villafane, A. [Centro de Investigaciones en Materiales Avanzados Leon Tolstoi, Chihuahua (Mexico)

    1997-06-01

    Susceptibility of martensitic type 410 (UNS S41000) stainless steel (SS) to environmental cracking was evaluated at 90 C in concentrated sodium chloride, sodium sulfate and sodium hydroxide solutions, all of which are environments related to steam turbine conditions, using the slow strain rate testing (SSRT) technique. In NaCl, the effects of solution pH, concentration, and anodic and cathodic polarization were investigated. Tests were supplemented by detailed electron fractography and hydrogen permeation measurements. A clear correlation was found between the degree of embrittlement and the amount of hydrogen permeating the steel, suggesting a hydrogen-induced cracking mechanism.

  17. Fractional excretion of sodium

    Science.gov (United States)

    FE sodium; FENa ... a lab. There, they are examined for salt (sodium) and creatinine levels. Creatinine is a chemical waste ... Chernecky CC, Berger BJ. Excretion fraction of filtered sodium-blood and urine. In: Chernecky CC, Berger BJ, ...

  18. Sodium and Food Sources

    Science.gov (United States)

    ... Disease Cholesterol High Blood Pressure Million Hearts® WISEWOMAN Sodium and Food Sources Recommend on Facebook Tweet Share ... food [PDF-867K] and how to reduce sodium. Sodium Reduction Is Challenging Types of food matter: More ...

  19. Gram-scale solution-phase synthesis of selective sodium bicarbonate co-transport inhibitor S0859: in vitro efficacy studies in breast cancer cells.

    Science.gov (United States)

    Larsen, Ann M; Krogsgaard-Larsen, Niels; Lauritzen, Gitte; Olesen, Christina W; Honoré Hansen, Steen; Boedtkjer, Ebbe; Pedersen, Stine F; Bunch, Lennart

    2012-10-01

    Na(+)-coupled HCO(3)(-) transporters (NBCs) mediate the transport of bicarbonate ions across cell membranes and are thus ubiquitous regulators of intracellular pH. NBC dysregulation is associated with a range of diseases; for instance, NBCn1 is strongly up-regulated in a model of ErbB2-dependent breast cancer, a malignant and widespread cancer with no targeted treatment options, and single-nucleotide polymorphisms in NBCn1 genetically link to breast cancer development and hypertension. The N-cyanosulfonamide S0859 has been shown to selectively inhibit NBCs, and its availability on the gram scale is therefore of significant interest to the scientific community. Herein we describe a short and efficient synthesis of S0859 with an overall yield of 45 % from commercially available starting materials. The inhibitory effect of S0859 on recovery of intracellular pH after an acid load was verified in human and murine cancer cell lines in Ringer solutions. However, S0859 binds very strongly to components in plasma, and accordingly, measurements on isolated murine tissues showed no effect of S0859 at concentrations up to 50 μM. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Effect of sodium carbonate catalyst weight on production of bio-oil via thermochemical liquefaction of corncobs in ethanol-water solution

    Science.gov (United States)

    Sembodo, Bregas Siswahjono Tatag; Sulistyo, Hary; Sediawan, Wahyudi Budi; Fahrurrozi, Mohammad

    2018-02-01

    Lignocellulosic biomass has recently received serious attention as an energy source that can replace fossil fuels. Corncob is one of lignocellulosic biomass wastes, which can be further processed into bio-oil through thermochemical liquefaction process. Bio-oil is expected to be further processed into fuel oil. In this research the effect of Na2CO3 catalyst weight on the yield of bio-oil was investigated. The composition of bio-oil produced in this process was analyzed by GC-MS. Bio-oil formation rate were analyzed through mathematical model development. First model aasumed as an isothermal process, while second model was not. It is found that both models were able to provide a good approach to experimental data. The average reaction rate constants was obtained from isothermal model, while the activation energy level and collision factors were obtained from non-isothermal model. The reaction rate will increase by addition of Na2CO3 (0 - 0.5 g) as catalyst to 250 mL system solution, then the activation energy will decrease from 1964.265 joules/mole to 1029.994 joules/mole. The GC-MS analysis results showed that the bio-oil were contained of ester compounds, phenolic compounds, cyclic compunds, heterocyclic compounds, and poly-alcohols compounds.

  1. A study of the catalytic role of a gold electrode in the electrochemical activation of four macrolide antibiotics in sodium bicarbonate solution

    Directory of Open Access Journals (Sweden)

    Milka L. Avramov Ivić

    2010-07-01

    Full Text Available Using the cyclic voltammetry, it has been shown that hydrogen evolution at a gold electrode is necessary in the electrochemical activation of azithromycin dihydrate and erythromycin A. After four hours of the potential holding at –1.2 V vs. SCE, the pH of the electrolyte has been changed from 8.40 to 8.96; from 8.40 to 8.77 in the presence of erythromycin A, and from 8.40 to 9.18 in the presence of azithromycin, indicating the reaction of the hydrogen species with antibiotics. This effect has been confirmed by using the phenolphthalein indicator and by analysing colours of the solutions by UV-Vis, as well as by FTIR spectroscopy. Under the identical experimental conditions at the gold electrode, in contrast to azithromycin dihydrate and erythromycin A, roxithromycin and midecamycin electroactivity promotion has been obtained during the first forward sweep starting from the area of a double layer region.

  2. 21 CFR 522.313c - Ceftiofur sodium.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ceftiofur sodium. 522.313c Section 522.313c Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Ceftiofur sodium. (a) Specifications. Each milliliter of aqueous solution constituted from ceftiofur sodium...

  3. 21 CFR 522.90c - Ampicillin sodium.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ampicillin sodium. 522.90c Section 522.90c Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Ampicillin sodium. (a) Specifications. Each milliliter of aqueous solution constituted from ampicillin sodium...

  4. 21 CFR 522.1883 - Prednisolone sodium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Prednisolone sodium phosphate. 522.1883 Section... § 522.1883 Prednisolone sodium phosphate. (a) Specifications. Each milliliter of solution contains 20 milligrams (mg) prednisolone sodium phosphate (equivalent to 14.88 mg of prednisolone). (b) Sponsor. See No...

  5. The aluminization of 600 k WLS fibers for the TileCal/ATLAS/LHC

    CERN Document Server

    Saraiva, J G; Maneira, M J P; Maio, A; Patriarca, J

    2004-01-01

    The TILE CALorimeter, the hadronic sampling calorimeter of ATLAS/LHC /CERN, is made of iron and polystyrene scintillating tiles. The light produced in scintillating tiles is absorbed and guided to the photomultipliers (PMTs) through wave length shifter (WLS) optical fibers. To optimize the detection of jets and muons, the top of the fibers away of the PMTs is coated with an aluminum mirror. This aluminum mirror is produced by planar magnetron sputtering. This process adds to an excellent reproducibility a minimal thermal aggression, important for a proper film adhesion to the plastic surface. To satisfy schedule and optical critical requirements, a dedicated mass production machine named SIDELO II was projected and constructed. A reflectivity of R similar to 75% is achieved and the light output uniformity improved by asymptotically equal to 10%. The aluminization of the fibers and their quality control started in August 1999 and went on continuously until May 2002. The quality control results showed a reprodu...

  6. Poly(carboxylate ether)-based superplasticizer achieves workability retention in calcium aluminate cement

    Science.gov (United States)

    Akhlaghi, Omid; Menceloglu, Yusuf Ziya; Akbulut, Ozge

    2017-01-01

    Calcium aluminate cement (CAC) suffers from loss of workability in less than an hour (~15 minutes) after first touch of water. Current superplasticizers that are utilized to modify the viscosity of cement admixtures are designed to target ordinary Portland cement (OPC). The high affinity between these superplasticizers and cement particles were found to be detrimental in CAC systems. Utilization of a monomer that, instead, facilitates gradual adsorption of a superplasticizer provides workability retention. For the first time in literature, we report a superplasticizer that caters to the properties of CAC such as high rate of surface development and surface charge. While neat CAC was almost unworkable after 1 hour, with the addition of only 0.4% of the optimized superplasticizer, 90% fluidity retention was achieved.

  7. Study of the ultrasonic waves action on the preparation of calcium aluminates cements

    International Nuclear Information System (INIS)

    Lourenco, R.R.; Exposito, C.C.D.; Rodrigues, J.A.

    2009-01-01

    Calcium aluminates cements were prepared through a route that uses the sonochemical process. In this process, calcia and alumina in an aqueous suspension are put under an ultrasonic bath during some time. After that, the water is evaporated and the material is heat treated. In this work, the action of ultrasonic waves were studied on initials molar compositions calcia:alumina of 1:1. It was also verified the influence of the water on the reactivity of initial solids. SEM and X-ray diffraction were used to characterize the obtained materials. In addition, mechanical strength of the products was evaluated through splitting tensile tests. The X-ray diffractograms showed that the presence of the water was enough to form hydrated compounds. However the material subjected to the sonochemical process presented the highest mechanical strength, indicating the potential of this route of synthesis. (author)

  8. Spectrographic determination of impurities in ceramic materials for nuclear fusion reactors. II. Analysis of magnesium aluminate

    International Nuclear Information System (INIS)

    Roca, M.; Rucandio, M.I.; Melon, A.

    1990-01-01

    The determination of minor and trace elements in the magnesium aluminate, considered as possible mataerial in thermonuclear fusion reactors, has been studied. The concentaration ranges are 0.1-0.3 % for Ca, Si and Y, and at the ppm level for Co, Cr, Fe, Hf, K, Li, Mn, Na, Ni, Sc, Ta, Ti, V and Zr. Atomic emission spectroscopy with direct current arc excitation and photographic detection has been employed. For Hf, Ta and Zr the use of 40% of copper fluoride as a carrier and of Nb as internal standard provide suitable sensitivities and precissions, while for the rest of elements the best results are obtained with graphite power in different proportions and Rb or Sn as internal standard. (Author). 4 refs

  9. Spectrographic Determination of Impurities in Ceramic Materials for Nuclear fusion Reactors. II. Analysis of Magnesium Aluminate

    International Nuclear Information System (INIS)

    Rucandio, M. I.; Roca, M.; Melon, A.

    1990-01-01

    The determination of minor and trace elements in the magnesium aluminate, considered as possible material in thermonuclear fusion reactors, has been studied. The concentration ranges are 0.1 - 0.3 % for Ca, SI and Y, and at the ppm level for Co, Cr, Fe, Hf, K, Li, Mn, Na, Ni, Se, Ta, Ti, V and Zr. Atomic emission spectroscopy with direct current are excitation and photographic detection has been employed. For Hf, Ta and Zr the use of 40% of copper fluoride as a carrier and of Nb as internal standard provide suitable sensitivities and precessions, while for the rest of elements the best results are obtained with graphite powder in different proportions and Rb or Sn as internal standard. (Author)4 refs

  10. Encapsulation of strontium aluminate phosphors to enhance water resistance and luminescence

    International Nuclear Information System (INIS)

    Zhu Yong; Zeng Jianghua; Li Wenyu; Xu Li; Guan Qiu; Liu Yingliang

    2009-01-01

    Strontium aluminate SrAl 2 O 4 :Eu 2+ ,Dy 3+ phosphors are chemically unstable against water or even moisture. To enhance the water resistance of the phosphors, an encapsulation was performed by direct surface reactions with phosphoric acid (H 3 PO 4 ). The morphology, surface structure, surface element composition, water resistance, luminescence, and photoacoustic spectrum of the phosphors before and after encapsulation were discussed. Experimental results showed that phosphors were perfectly encapsulated by amorphous layers in nanoscale and crystalline layers in microscale under different conditions. The water resistance of phosphors was greatly enhanced by the two types of layer. More importantly, the amorphous layers enhanced the luminescence of phosphors markedly. The possible mechanism for the enhancements was also proposed.

  11. Neutron Diffraction Characterization of C–H···Li Interactions in a Lithium Aluminate Polymer

    Energy Technology Data Exchange (ETDEWEB)

    Cole, Jacqueline M.; Waddell, Paul G.; Wheatley, Andrew E. H.; McIntyre, Garry J.; Peel, Andrew J.; Tate, Christopher W.; Linton, David J.

    2014-08-11

    The reaction of AlMe3 with tBuLi in the presence of trimethylacetonitrile affords the bimetallic complex [tBu(Me)Al(μ-Me)2Li·NC(tBu)]∞ (1). Pseudotetrahedral Al centers form by the nucelophilic addition of tBuLi to AlMe3.The alkali-metal center is stabilized through coordination of the unreacted nitrile and polymer formation via the construction of Al(μ-Me)nLi (n = 1, 2) motifs. Neutron diffraction evidences agostic interactions in the bridging methyl group to give further stabilization. There is only one previous report of a neutron structure of a lithium aluminate compound. This work therefore offers an important structural example of agostic interactions and the precise nature of Al(μ-Me)2Li bridging.

  12. Optical properties of rare earth doped strontium aluminate (SAO) phosphors: A review

    Science.gov (United States)

    Kshatri, D. S.; Khare, A.

    2014-11-01

    After the first news on rare earth (RE) doped strontium aluminate (SAO) phosphors in late 1990s, researchers all over the world geared up to develop stable and efficient persistent phosphors. Scientists studied various features of long lasting phosphors (LLP) and tried to earmark appropriate mechanism. However, about two decades after the discovery of SrAl2O4: Eu2+, Dy3+, the number of persistent luminescent materials is not significant. In this review, we present an overview of the optical characteristics of RE doped SAO phosphors in terms of photoluminescence (PL), thermoluminescence (TL) and afterglow spectra. Also, we refresh the work undertaken to study diverse factors like dopant concentration, temperature, surface energy, role of activator, etc. Simultaneously, some of our important findings on SAO are reported and discussed in the end.

  13. The Effect of (Ag, Ni, Zn-Addition on the Thermoelectric Properties of Copper Aluminate

    Directory of Open Access Journals (Sweden)

    Jianxiao Xu

    2010-01-01

    Full Text Available Polycrystalline bulk copper aluminate Cu1-x-yAgxByAlO2 with B = Ni or Zn were prepared by spark plasma sintering and subsequent thermal treatment. The influence of partial substitution of Ag, Ni and Zn for Cu-sites in CuAlO2 on the high temperature thermoelectric properties has been studied. The addition of Ag and Zn was found to enhance the formation of CuAlO2 phase and to increase the electrical conductivity. The addition of Ag or Ag and Ni on the other hand decreases the electrical conductivity. The highest power factor of 1.26 × 10-4 W/mK2 was obtained for the addition of Ag and Zn at 1,060 K, indicating a significant improvement compared with the non-doped CuAlO2 sample.

  14. Parameters governing tritium extraction rates from lithiated ceramics. The case of lithium aluminate

    International Nuclear Information System (INIS)

    Roth, E.; Botter, F.; Briec, M.; Rasneur, B.; Roux, N.

    1986-10-01

    Significant discrepancies between results of authors comparing tritium extraction rates from different lithiated ceramics are found in the literature. Recent results obtained at C.E.A., principally on lithium aluminates, show that, for a given ceramic, parameters other than textural (grain size, porosity, etc...) may play a predominant role. Enhancements of extraction rates have been induced by adding MgO to the solid or H 2 and CO to the sweep gas, but other factors, probably related to the surface condition of samples, may produce even greater effects. Results of investigations of the influence of exposure to air at given partial pressures of water vapor or of CO 2 show that strict preirradiation procedures must be adopted for preparation, storage and handling of ceramic tritium breeders

  15. Structural simulation of superlattices in lithium aluminates; Simulacion estructural de superredes en aluminatos de litio

    Energy Technology Data Exchange (ETDEWEB)

    Carrera G, L.M.; Basurto S, R. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1997-07-01

    Among the materials to be used on the tritium generator cover of the future fusion reactors the lithium aluminate ({gamma} - LiAlO{sub 2}) is one of the more studied. In this work it is presented the superlattice structural simulation that presents to {gamma} - LiAlO{sub 2} as main phase and to {alpha} - LiAlO{sub 2} as the secondary phase. The simulation is developed considering that as the two phases present different symmetry ({gamma} - LiAlO{sub 2} is tetrahedral and {alpha} - LiAlO{sub 2} is hexahedral) it is had a superlattice LUCS type (Layered Ultrathin Coherent Structure) that is it presents an structure in coherent ultrathin layers since it is what implicates a lesser energy of formation. (Author)

  16. Radioprotective effects of sodium tungstate in mice

    International Nuclear Information System (INIS)

    Sato, Kaoru; Ichimasa, Michiko; Suzuki, Saeko; Shiomi, Masae; Ichimasa, Yusuke; Miyahara, Kenzo; Nishimura, Yoshikazu

    2000-01-01

    The radioprotective effects of sodium tungstate on gamma-ray (9.8 Gy) induced decreases in survival rate, and hematocrit value in male and female mice were examined. Daily ingestion of 0.02% sodium tungstate solution (33-36 mg/kg body weight/day) as drinking water from 7 days before and up to 60 days after irradiation significantly mitigated the decrease in hematocrit value, especially at 21 days after irradiation. The increase in survival rate was observed in male and female mice administered sodium tungstate solution. As for its radioprotective effects, no significant sex differences were observed. (author)

  17. Influence of de-aluminating techniques of Y zeolite on its physico-chemical properties and on its catalytic performances in N-decane hydro-cracking; Influence des techniques de desalumination de la zeolithe Y sur ses proprietes physico-chimiques et sur ses performances catalytiques en hydrocraquage du N-decane

    Energy Technology Data Exchange (ETDEWEB)

    Gola, A.

    1996-12-16

    De-aluminated HY samples with constant amounts of framework aluminium and varying amounts of extra framework aluminium have been prepared and characterized. The influence of extra framework aluminium (EFAL) species in hydrocracking of n-decane at a hydrogen pressure of 60 bars has been evaluated. The methods used to de-aluminate the Y zeolite involved high temperature steaming followed by treatments with aqueous solutions of nitric acid, (NH{sub 4}){sub 2}SIF{sub 6}(AHFS) or Na{sub 2}EDTA to control the elimination of the EFAI. The chemical composition of the resulting samples indicates that only AHFS and Na{sub 2}EDTA are able to eliminate controlled amounts of EFAI without de-aluminating the framework. Several types of EFAI are detected, their localisation is proposed and their ease of extraction by the different reagents is investigated. Treatment with nitric acid or Na{sub 2}EDTA leads to increase of the meso-porous volume whereas AHFS leads to a silicon deposit and very low meso-porous volumes. The number and strength of acid sites in all treated samples is higher than in the steamed zeolite. Hydrocracking of n-decane under high hydrogen pressure (60 bars) at 260 deg C was chosen as a test reaction. The catalysts were prepared by two methods: mechanical mixing of the zeolite with alumina supported platinum and incipient wetness impregnation of platinum on the zeolite. It is shown that the proximity of acid and metallic sites in the latter leads to high yields of isomerization products. The amount and nature of the EFAI, and the meso-porous texture of the samples studied, have little influence on the catalytic properties (in terms of selectivity or acidity) of de-aluminated zeolite Y. Only the steamed zeolite shows in some conditions a lower activity and selectivity towards isomerized products. (author) 145 refs.

  18. Determination of hydroxide in the presence of aluminate using a modified potentiometric titration

    International Nuclear Information System (INIS)

    Hanson, T.J.

    1975-11-01

    A procedure for the determination of hydroxide concentration in the presence of aluminate and other interfering ions was developed using the method of standard additions (or more specifically in this case, standard subtractions). The procedure called for titration with a strong acid which was added in equal increments at regular time intervals. The potential was recorded after each addition of acid. The data was plotted on Gran's Plot Paper, which is based on work done originally by Gran, or it was entered into a computer to determine the equivalence volume of the titrant. When used on many different samples in different matrices, the method gave results that were approximately 100 +- 1 percent of the calculated value. This was shown to be true even in systems containing aluminate [Al(OH) 4 - ], phosphate (PO 4 3- ), sulfate (SO 4 2- ), nitrate (NO 3 - ), nitrite (NO 2 - ), carbonate (CO 3 2- ), and other ions. The effect of these ions was shown to be negligible if the initial OH - concentration was at least 10 -3 M and barium chloride (BaCl 2 ) was added to complex the PO 4 3- and CO 3 2- ions. These ions were checked at levels of up to 3 M for Al(OH) 4 - and NO 3 - , 2 M for NO 2 - , and 1 M for SO 4 2- , PO 4 3- , and CO 3 2- . The method is applicable to radioactive as well as nonradioactive samples and any heat involved with a radioactive sample is insufficient to cause an error in the determination. On the basis of the work performed it was shown that the method was general enough to be run on a routine basis

  19. The Piriá aluminous lateritic profile: mineralogy, geochemistry and parent rock

    Directory of Open Access Journals (Sweden)

    Pabllo Henrique Costa dos Santos

    Full Text Available ABSTRACT: Relatively small aluminous lateritic deposits are abundant in the northeast and northwest parts of the Pará and Maranhão states, respectively. Most of them hosts aluminum phosphate mineralization forming hills and plateaus that stand out in the topography of the undulating plains of this region. The Piriá ridge is one of those topographic features, covered by lateritic iron crusts that have been studied in the 1970s as part of iron ore exploration campaigns and recently for phosphates prospection. This study improves the knowledge about the evolution of the lateritic Piriá deposit and demonstrates its relationship with the most evolved laterites of the Amazon, known as mature laterites, which formed major ore deposits during the Paleogene. Samples of a 17 meter-deep borehole were investigated through mineralogical (X-ray diffraction -XRD, optical and electron microscopy and chemical methods (inductively coupled plasma mass spectrometry - ICP-MS, inductively coupled plasma optical emission spectrometry - ICP-OES and X-ray fluorescence - XRF. The studied lateritic profile comprises a clay bauxitic horizon overlaid by an aluminous iron crust. Upwardly continuous dissolution of kaolinite occurs with the formation of gibbsite, as the result of intensive leaching, resulting in a higher Al2O3 content in the crust. The continuous formation of hematite from goethite resulted from the transition to more arid conditions. Anatase is a newly formed mineral (100-400 nm crystallites, showing a gradual increase, following the increase in TiO2 content, which is high and indicative of a mafic parent rock, confirmed by the Ti × Zr dispersion pattern. Prominent zoning in the lateritic profile is characterized by the mineralization in bauxite and augelite and abrupt chemical transition between the horizons, marked by a decrease in Si and increase in Fe content from the bottom to the top of the profile. These features are compatible and indicative of

  20. Preparation, characterization and catalytic properties of nickel aluminate nanoparticles: A comparison between conventional and microwave method

    Directory of Open Access Journals (Sweden)

    C. Ragupathi

    2017-01-01

    Full Text Available In the present work, synthesis of nickel aluminate using Opuntia dilenii haw as plant extract by a microwave combustion method (MCM and its comparison with the conventional combustion method (CCM is investigated. O. dilenii haw plant extract simplifies the process, provides an alternative process for a simple and an economical synthesis. The absence of surfactant has led to a simple, cheap and fast method of synthesis of NiAl2O4 nanoparticles. The as-synthesized NiAl2O4 nanoparticles were characterized by X-ray diffraction (XRD studies, Fourier transform infrared spectroscopy (FT-IR studies, high resolution scanning electron microscopy (HR-SEM, energy dispersive X-ray analysis (EDX, high resolution transmission electron microscopy (HR-TEM, diffuses reflectance spectroscopy (DRS, and Brunauer Emmett Teller (BET surface area analysis. The XRD results confirmed the formation of the cubic phase NiAl2O4. The formation of pure nickel aluminate phase was confirmed by FT-IR. The formation of NiAl2O4 nanoparticles was confirmed by HR-SEM and HR-TEM and their possible formation mechanisms were also proposed. MCM could produce NiAl2O4 with uniform size and well-defined shape with crystallinity. The optical property was determined by DRS. NiAl2O4 prepared by the microwave combustion method was found to possess a higher surface area, lower crystallite size than the NiAl2O4 nanoparticles prepared by the conventional combustion method, which in turn has led to the improved performance toward the selective oxidation of benzyl alcohol to benzaldehyde.

  1. Irradiation damage in gamma lithium aluminate - LiAlO2

    International Nuclear Information System (INIS)

    Auvray-Gely, M.H.

    1989-01-01

    Single crystals of gamma lithium aluminate (of tetragonal structure) are irradiated) with various projectiles (electrons, He ions, protons, X and gamma photons) and we used (i) electronic paramagnetic resonance (EPR) and optical absorption to detect the defects produced, and (ii) transmission electron microscopy (TEM). The lithium aluminate single crystals irradiated with electrons or ions contain five different paramagnetic defects. Each of them has several anisotropic configurations whose EPR signals (i) have a Lande factor close to 2, (ii) exhibit a resolved hyperfine structure and (iii) are identical only when the static magnetic field is along /001/. In addition, four optical absorption bands appear in the range 1-6 eV in the same irradiation conditions. But only three among the five paramagnetic defects and one of the optical bands appear in X-and gamma-ray irradiated samples. Using these observations, we discuss the nature of the detected defects and we conclude about the type of their production mechanism. Particularly, we assign a six-line EPR signal and an optical band in the ultraviolet range to the F + -centre. We compare this hypothesis to a defect model based on the computation of approximate electronic wave functions using the variational method. Our TEM study shows that when gamma-LiAlO 2 single crystals are irradiated with 1 MeV electrons (fluence: 10 20 electrons/sqcm), tridimensional defects (of mean dimension 100 nm) appear. At lower energies, the defect production is hidden by a thermal effect that is sufficient to induce the evaporation of lithium oxyde and the formation of LiAl 5 0 8 [fr

  2. Comparison of colon-cleansing methods in preparation for colonoscopy - Comparative efficacy of solutions of mannitol, sodium picosulfate and monobasic and dibasic sodium phosphates Estudo comparativo entre as soluções de manitol, picossulfato de sódio e fosfato monobásico e dibásico de sódio no preparo de cólon para colonoscopia

    Directory of Open Access Journals (Sweden)

    Paulo Miki Jr

    2008-01-01

    Full Text Available PURPOSE: Colonoscopy plays an essential role in the therapeutic and diagnostic approach in various colonic pathologies, the aim of the present study was to compare three solutions and their efficacy for the bowel preparation in adult patients submitted to elective colonoscopy. METHODS: Sixty patients were randomly divided into three groups of 20 each. Each group was submitted to a bowel preparation with one of the following solutions: 10% manitol, sodium picosulphate or sodium phosphate. The parameters evaluated were: taste, tolerance, associated side effects and quality of cleansing. Postural blood pressure and pulse rate as well as serum sodium, potassium, calcium and phosphate were compared. RESULTS: Sodium phosphate and 10% manitol solutions provided superior results in terms of colon cleansing compared to sodium picosulphate solution. All serum electrolytes evaluated were significantly altered in the three groups, without important clinical signs. DISCUSSION: High levels of serum phosphate were the most striking alteration in patients prepared with sodium phosphate solution, again with no clinical signs. Variations related to blood pressure and pulse rate suggested contraction of intravascular volume, with no clinical effects. CONCLUSION: Sodium phosphate and 10% manitol solutions are equivalent in providing good quality colon cleansing, with no significant side effects that could compromise the procedure.INTRODUÇÃO: A colonoscopia é exame fundamental na avaliação das doenças do cólon e na abordagem terapêutica de determinado grupo de patologias. O preparo intestinal é obrigatório para a realização das colonoscopias eletivas, e a qualidade encontra-se relacionada ao sucesso do procedimento. Comparou-se três soluções para limpeza anterógrada do cólon em pacientes adultos, submetidos à colonoscopia. METODOS: Sessenta pacientes foram distribuídos em três grupos de vinte. Cada grupo realizou o preparo do cólon com uma das

  3. Small-angle neutron scattering study of sodium cholate and sodium ...

    Indian Academy of Sciences (India)

    Unknown

    Abstract. Small angle neutron scattering (SANS) measurements of D2O solutions. (0⋅1 M) of sodium cholate (NaC) and sodium deoxycholate (NaDC) were carried out at T = 298 K. Under compositions very much above the critical micelle concentration. (CMC), the bile salt micelle size growths were monitored by adopting ...

  4. Liquid sodium pool fires

    International Nuclear Information System (INIS)

    Casselman, C.

    1979-01-01

    Experimental sodium pool combustion results have led to a definition of the combustion kinetics, and have revealed the hazards of sodium-concrete contact reactions and the possible ignition of organic matter (paint) by hydration of sodium peroxide aerosols. Analysis of these test results shows that the controlling mechanism is sodium evaporation diffusion. (author)

  5. Phase transformations in lithium aluminates irradiated with neutrons; Transformaciones de fase en aluminatos de litio irradiados con neutrones

    Energy Technology Data Exchange (ETDEWEB)

    Carrera, L.M.; Delfin L, A.; Urena N, F.; Basurto, R. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Bosch, P. [UAM-I, 09340 Mexico D.F. (Mexico)

    2003-07-01

    The lithium aluminate like candidate to be used in the coverings producers of tritium in the fusion nuclear reactors, presents high resistance to the corrosion to the one to be stuck to structural materials as special steels. However, the crystallographic changes that take place in the cover that is continually subjected to irradiation with neutrons, can alter its resistance to the corrosion. In this work the changes of crystalline structure are shown that they present two types of nano structures of lithium aluminates, subjected to an average total dose 7.81 x 10{sup 8} Gy in the fixed irradiation system of capsules of the one TRIGA Mark lll nuclear reactor of the Nuclear Center of Mexico. The studied nano structures presented only phase transformations without formation of amorphous material. (Author)

  6. The effects of topical agents of fluticasone propionate, oxymetazoline, and 3% and 0.9% sodium chloride solutions on mucociliary clearance in the therapy of acute bacterial rhinosinusitis in vivo.

    Science.gov (United States)

    Inanli, Selçuk; Oztürk, Ozmen; Korkmaz, Mukadder; Tutkun, Alper; Batman, Cağlar

    2002-02-01

    The aims of the study were to determine: 1) how mucociliary activity in acute bacterial rhinosinusitis is affected; 2) how this activity is changed by therapy; 3) the effects of topical agents on mucociliary clearance, and 4) the most appropriate topical agent(s) to be used in the therapy of sinusitis. Five groups of patients with acute bacterial rhinosinusitis were studied prospectively. All patients had 500 mg oral amoxicillin and 125 mg oral clavulanic acid preparations given three times daily for 3 weeks. According to the topical agent applications, these groups included: group I (n = 12), no topical treatment was given; group II (n = 14), two puffs for each nostril once daily of 50 microg/100 mL fluticasone propionate was given; group III (n = 9), one puff for each nostril three times daily of 0.05% oxymetazoline was given; group IV (n =12), 3% sodium chloride (NaCl) (buffered to pH 6.5-7 at room temperature) was given; and group V (n =13), 10-mL solutions of 0.9% NaCl (buffered to pH 6.5--7 at room temperature) were given for nasal irrigations three times daily. All patients had medication for 3 weeks and were controlled each week. The saccharin method was used to measure nasal mucociliary clearance. To investigate the early effects of the topical agents for groups II to V, an additional test was repeated 20 minutes after the basal mucociliary clearance recordings. The test was repeated in the first, second, and third weeks of the treatment. The mucociliary clearance was significantly slower in the acute bacterial rhinosinusitis group than in the control group. There was no significant difference between the basal mucociliary clearance and the 20th minute mucociliary clearance of the fluticasone propionate and 0.9% NaCl solution groups. The mean values of the basal and the 20 minute's mucociliary clearance of the oxymetazoline group were 24.72 +/- 6.16 and 15.5 +/- 7.45 minutes, respectively, which were statistically significant. The mean values of the basal

  7. Determination of chloride and sulphur in sodium by ion chromatography and its application to PFBR sodium samples

    International Nuclear Information System (INIS)

    Vijayalakshmi, S.; Ushalakshmi, K.

    2011-01-01

    Analytical method using ion chromatography was developed for the determination of chloride and sulphur in sodium. In this method, sodium was dissolved in water and various sulphur species present in the sample was oxidized to sulphate using hydrogen peroxide. Carbon dioxide gas was passed through the solution to convert sodium hydroxide to carbonate solution. The resulting sample solution was analysed using suppressed Ion chromatography employing carbonate eluent. This method was applied to the analysis of sodium samples procured for prototype fast breeder reactor. (author)

  8. Developpement d'un catalyseur nickel-alumine efficace pour le reformage de diesel a la vapeur d'eau et etude du systeme reactionnel

    Science.gov (United States)

    Fauteux-Lefebvre, Clemence

    Le developpement de sources d'energie alternatives fiables et efficaces est aujourd'hui une necessite. L' interet dans le reformage d'hydrocarbures liquides est ainsi croissant puisqu'il s'agit d'une voie pour l'alimentation des piles a combustible. Les piles a combustible ont une efficacite pour la conversion d'energie en electricite plus grande que celle des moteurs a combustion et font ainsi partie de la recherche de solution en efficacite energetique. Ces piles consomment de l'hydrogene comme combustible pour produire de l'electricite, d'ou l'interet pour le reformage. En effet, cette reaction permet de produire de l'hydrogene et du monoxyde de carbone (un autre combustible des piles a combustible a electrolyte solide) a partir d'hydrocarbure liquide, notamment le diesel. Les piles pourraient donc etre integrees avec une unite de reformage leur fournissant directement le combustible necessaire a partir de diesel. Dans ce projet de recherche, un nouveau catalyseur de nickel sous forme de spinelle nickel-alumine (spinelle NiAl2O4 sur support d'alumine et de zircone stabilisee avec yttria) a ete developpe et teste en laboratoire pour du reformage de propane, d'hydrocarbures liquides et de diesel, a la vapeur d'eau. Par ailleurs, une methode d'ajout des reactifs novatrice a ete utilisee afin de diminuer la pyrolyse precedant le reformage, en utilisant une emulsion. Les resultats de reformage d'hydrocarbures purs ont montre des concentrations tres pres de l'equilibre thermodynamique et une activite constante sans desactivation du catalyseur ni formation de carbone, et ce avec des ratios H2O/C de moins de 2.5 et des temperatures d'operation variant entre 630 °C et 750 °C. Lors de tests effectues en utilisant du diesel fossile, a 705°C, avec un debit volumique des reactifs de plus de 50 000 cm3gcat-1h-1 et un ratio H2O/C de moins de 2.5, l'activite a ete maintenue pendant plus de 15 heures, malgre une operation en cycles. L'analyse du catalyseur apres cette

  9. Small angle neutron scattering studies of mixed micelles of sodium

    Indian Academy of Sciences (India)

    The aqueous solutions of sodium cumene sulphonate (NaCS) and its mixtures with each of cetyl trimethylammonium bromide (CTAB) and sodium dodecyl sulphate (SDS) are characterized by small angle neutron scattering (SANS). NaCS when added to CTAB solution leads to the formation of long rod-shaped micelles with ...

  10. Mutable Lewis and Bronsted Acidity of Aluminated SBA-15 as Revealed by NMR of Adsorbed Pyridine-(15)N

    Czech Academy of Sciences Publication Activity Database

    Gurinov, A. A.; Rozhkova, Yu. A.; Zukal, Arnošt; Čejka, Jiří; Shenderovich, I, G.

    2011-01-01

    Roč. 27, č. 19 (2011), s. 12115-12123 ISSN 0743-7463 R&D Projects: GA AV ČR KAN100400701; GA ČR GA203/08/0604 Institutional research plan: CEZ:AV0Z40400503 Keywords : 15N NMR * post-synthesis alumination * phase Beckmann rearrangement Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.186, year: 2011

  11. A Force field for tricalcium aluminate to characterize surface properties, initial hydration, and organically modified interfaces in atomic resolution

    OpenAIRE

    Mishra, Ratan K.; Fernández Carrasco, Lucía; Flatt, Robert J.; Heinz, Hendrik

    2014-01-01

    Tricalcium aluminate (C3A) is a major phase of Portland cement clinker and some dental root filling cements. An accurate all-atom force field is introduced to examine structural, surface, and hydration properties as well as organic interfaces to overcome challenges using current laboratory instrumentation. Molecular dynamics simulation demonstrates excellent agreement of computed structural, thermal, mechanical, and surface properties with available experimental data. The parameters are integ...

  12. Components inspection of Monju, a sodium bonded type control rod

    International Nuclear Information System (INIS)

    Harada, Kiyoshi; Matsushita, Yuichi; Lee, Chunchan; Abe, Hideaki; Watahiki, Naohisa

    2002-03-01

    This Report addresses a result of a sodium test conducted on components of a Double Poral Filter Sodium Bonded Type Control Rod that is expected to be a next generation, long life Control Rod. Upper and lower Poral Filter Sodium Bonded Type Control Rod components were mocked up to conduct a sodium test. During the test, sodium chargeability, formation of Gas Plenum at the upper part of the components, sodium drain-ability and NaOH clean-ability were recognized under actual plant condition. The following are results obtained: (1) Sodium Chargeability at Control Rod Insertion to EVST. Sodium was charged into the components when the mocked-up was inserted in sodium of 190degC, with insertion speed of 6 m/min which is an actual insertion speed to EVST. (2) Formation of Upper Gas Plenum by Helium Gas generated in Control Rod Components Gas Plenum formation within deviation of 9% was confirmed by releasing helium gas into the mocked-up which is immersed in sodium of 620degC and 190degC. Length of Gas Plenum is confirmed to be retained in certain length even if helium gas is further released into formed Gas Plenum. (3) Sodium Drain-ability of Control Rod Components when Drawing from EVST. Drain-ability was confirmed to be sufficient and no sodium residue was found in the mocked-up when the mocked-up was drawn out from sodium of 190degC, with drawing speed of 6 m/min which is an actual drawing speed from EVST. (4) Clean-ability of NaOH Solution against Sodium Residue in Control Rod Components. Sodium and NaOH solution reacted calmly, however, clean-ability was not sufficient. When Sodium fully remained in Control Rod Components, it made circulation of NaOH solution not enough. (author)

  13. BLENDED CALCIUM ALUMINATE-CALCIUM SULFATE CEMENT-BASED GROUT FOR P-REACTOR VESSEL IN-SITU DECOMMISSIONING

    Energy Technology Data Exchange (ETDEWEB)

    Langton, C.; Stefanko, D.

    2011-03-10

    The objective of this report is to document laboratory testing of blended calcium aluminate - calcium hemihydrate grouts for P-Reactor vessel in-situ decommissioning. Blended calcium aluminate - calcium hemihydrate cement-based grout was identified as candidate material for filling (physically stabilizing) the 105-P Reactor vessel (RV) because it is less alkaline than portland cement-based grout which has a pH greater than 12.4. In addition, blended calcium aluminate - calcium hemihydrate cement compositions can be formulated such that the primary cementitious phase is a stable crystalline material. A less alkaline material (pH {<=} 10.5) was desired to address a potential materials compatibility issue caused by corrosion of aluminum metal in highly alkaline environments such as that encountered in portland cement grouts [Wiersma, 2009a and b, Wiersma, 2010, and Serrato and Langton, 2010]. Information concerning access points into the P-Reactor vessel and amount of aluminum metal in the vessel is provided elsewhere [Griffin, 2010, Stefanko, 2009 and Wiersma, 2009 and 2010, Bobbitt, 2010, respectively]. Radiolysis calculations are also provided in a separate document [Reyes-Jimenez, 2010].

  14. Characterization of mechanical properties of aluminized coatings in advanced gas turbine blades using a small punch method

    Energy Technology Data Exchange (ETDEWEB)

    Sugita, Y.; Ito, M. [Chuba Electric Power Co., Nagoya (Japan). Electric Power R and D Center; Sakurai, S. [Hitachi Ltd. (Japan). Mechanical Engineering Research Lab.; Bloomer, T.E.; Kameda, J. [Ames Lab., IA (United States)]|[Iowa State Univ., Ames, IA (United States). Center for Advanced Technology Development

    1997-04-01

    Advanced technologies of superalloy casting and coatings enable one to enhance the performance of combined cycle gas turbines for electric power generation by increasing the firing temperature. This paper describes examination of the microstructure/composition and mechanical properties (22--950 C) in aluminized CoCrAlY coatings of advanced gas turbine blades using scanning Auger microprobe and a small punch (SP) testing method. Aluminized coatings consisted of layered structure divided into four regimes: (1) Al enriched and Cr depleted region, (2) Al and Cr graded region, (3) fine grained microstructure with a mixture of Al and Cr enriched phases and (4) Ni/Co interdiffusion zone adjacent to the interface. SP specimens were prepared in order that the specimen surface would be located in the various coating regions. SP tests indicated strong dependence of the fracture properties on the various coatings regimes. Coatings 1 and 2 with very high microhardness showed much easier formation of brittle cracks in a wide temperature range, compared to coatings 3 and 4 although the coating 2 had ductility improvement at 950 C. The coating 3 had lower room temperature ductility than the coating 4. However, the ductility in the coating 3 exceeded that in the region 4 above 730 C due to a precipitous ductility increase. The integrity of aluminized coatings while in-service is discussed in light of the variation of the low cycle fatigue life as well as the ductility in the layered structure.

  15. Tensiometric, fluorescence and 1H NMR study of mixed micellization of non-steroidal anti-inflammatory drug sodium salt of ibuprofen in the presence of non-ionic surfactant in aqueous/urea solutions

    International Nuclear Information System (INIS)

    Rub, Malik Abdul; Khan, Farah; Sheikh, Mohmad Shafi; Azum, Naved; Asiri, Abdullah M.

    2016-01-01

    Highlights: • Interaction between (IBF + TX-100) mixtures has been investigated. • (IBF + TX-100) mixtures exhibit synergistic behavior. • Urea increases the surface charge of the micelles resulting halt of the micelles formation. • N agg , K sv and dielectric constant of mixed systems have also been evaluated. • 1 H NMR data suggested that IBF and TX-100 interacts through hydrophobic as well as hydrophillic interaction. - Abstract: The desirable surface/bulk properties for specific applications of drug sodium salt of ibuprofen (IBF) and Triton X-100 (TX-100) can be achieved by adjusting mainly the composition of these systems. The interactions of anionic drug IBF with non-ionic surfactant TX-100 micelles have been investigated using tensiometry, fluorometry and 1 H NMR in aqueous as well in 250 mmol⋅kg −1 urea solutions. Different theoretical models like Clint, Rubingh, and Rosen, etc. were utilized to get information about the nature of interaction between these two in bulk and at the interface. These models disclose that the non-ideal behavior with attractive interaction in bulk and at the interface exists. The steady-state fluorescence quenching study was employed to evaluate micelle aggregation numbers (N agg ), which signify the involvement of surfactant was forever higher compared to IBF. Stern–Volmer binding constants (K sv ), micropolarity (I 1 /I 3 ) and dielectric constant (D exp ) of the mixtures are also obtained using fluorescence method. By the addition of urea raise in the surface charge of the micelles was observed followed by halt of the micellization of drug and surfactant as well as their mixture, therefore cmc values increases followed by decrease in aggregation number. The 1 H NMR resonance intensity variations were paralleled by upfield shifts in the resonance frequencies, due to an increased shielding of IBF happening from closeness of the non-ionic TX-100 surfactant.

  16. Chemical elimination of alumina in suspension in nuclear reactors heavy water; Elimination de l'alumine en suspension dans l'eau lourde des reacteurs nucleaires par voie chimique

    Energy Technology Data Exchange (ETDEWEB)

    Ledoux, A. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-02-01

    Corrosion of aluminium in contact with moderating water in nuclear reactor leads to the formation of an alumina hydrosol which can have an adverse effect on the operation of the reactor. Several physical methods have been used in an attempt to counteract this effect. The method proposed here consists in the elimination of the aluminium by dissolution and subsequent fixation in the ionic form on mixed-bed ion-exchange resin. In order to do this, the parameters and the values of these parameters most favorable to the dissolution process have been determined. If the moderator is heavy water, the deuterated acid can be prepared by converting a solution in heavy water to a salt of the acid using a deuterated cationic resin. (author) [French] La corrosion de l'aluminium au contact de l'eau moderatrice des reacteurs nucleaires, donne lieu a la formation d'un hydrosol d'alumine nuisible au bon fonctionnement des reacteurs. Plusieurs methodes physiques ont ete mises en oeuvre pour pallier ces inconvenients. On propose ici d'eliminer l'alumine par solubilisation pour la fixer ensuite sous forme ionique par des resines echangeuses d'ions, en lit melange. A cette fin on determine les parametres et leurs grandeurs favorables a cette solubilisation. Si le moderateur est de l'eau lourde la preparation d'acide deutere peut etre effectuee par passage d'une solution en eau lourde a un sel de l'acide sur resine cationique deuteree.

  17. PLUTONIUM SOLUBILITY IN SIMULATED SAVANNAH RIVER SITE WASTE SOLUTIONS

    Energy Technology Data Exchange (ETDEWEB)

    Rudisill, T.; Hobbs, D.; Edwards, T.

    2010-09-27

    To address the accelerated disposition of the supernate and salt portions of Savannah River Site (SRS) high level waste (HLW), solubility experiments were performed to develop a predictive capability for plutonium (Pu) solubility. A statistically designed experiment was used to measure the solubility of Pu in simulated solutions with salt concentrations and temperatures which bounded those observed in SRS HLW solutions. Constituents of the simulated waste solutions included: hydroxide (OH{sup -}), aluminate (Al(OH){sub 4}{sup -}), sulfate (SO{sub 4}{sup 2-}), carbonate (CO{sub 3}{sup 2-}), nitrate (NO{sub 3}{sup -}), and nitrite (NO{sub 2}{sup -}) anions. Each anion was added to the waste solution in the sodium form. The solubilities were measured at 25 and 80 C. Five sets of samples were analyzed over a six month period and a partial sample set was analyzed after nominally fifteen months of equilibration. No discernable time dependence of the measured Pu concentrations was observed except for two salt solutions equilibrated at 80 C which contained OH{sup -} concentrations >5 mol/L. In these solutions, the Pu solubility increased with time. This observation was attributed to the air oxidation of a portion of the Pu from Pu(IV) to the more soluble Pu(V) or Pu(VI) valence states. A data driven approach was subsequently used to develop a modified response surface model for Pu solubility. Solubility data from this study and historical data from the literature were used to fit the model. The model predicted the Pu solubility of the solutions from this study within the 95% confidence interval for individual predictions and the analysis of variance indicated no statistically significant lack of fit. The Savannah River National Laboratory (SRNL) model was compared with predicted values from the Aqueous Electrolyte (AQ) model developed by OLI Systems, Inc. and a solubility prediction equation developed by Delegard and Gallagher for Hanford tank waste. The agreement between

  18. Interaction of theobromine with sodium benzoate

    Energy Technology Data Exchange (ETDEWEB)

    Nishijo, J.; Yonetani, I.

    1982-03-01

    The interaction of theobromine with sodium benzoate was investigated by PMR spectroscopy. The interaction of theobromine with pentadeuterated benzoic acid (benzoic acid-d5) was examined in the same manner but to a lesser degree. Chemical shifts of theobromine protons were determined as a function of sodium benzoate concentration in deuterium oxide at 30 and 15 degrees. Signals of both methyl groups of theobromine underwent significant upfield shifts when sodium benzoate was added to a theobromine solution. This fact suggests that a complex is formed by vertical stacking or plane-to-plane stacking. The same results were obtained for benzoic acid-d5.

  19. Characterization of films formed by the aluminizing of T91 steel

    Science.gov (United States)

    Sanabria Cala, J. A.; Conde Rodríguez, G. R.; Y Peña Ballesteros, D.; Laverde Cataño, D.; Quintero Rangel, L. S.

    2017-12-01

    The aluminizing of a T91 martensitic ferritic steel was carried out by a novel modification to the traditional technique of packed cementation, with the objective of producing a diffusion coating of aluminum in a shorter time and operating cost, from a technique that allows the reuse of powder packaging and which the coating of metal parts with complex shapes can be secured. As an aluminum source, commercial foil is used to wrap the piece to be coated, while the powder packaging contains aluminum oxide Al2O3 and an activating salt, ammonium chloride NH4Cl. During the deposition process of the coating, the NH4Cl is decomposed by reacting with foil, and thus, aluminum halides can be transferred to the metallic substrate, which deposit aluminum on the T91 steel surface while Al2O3 can be recycled for subsequent processes. The results of the diffractograms and micrographs indicated the strong influence of temperature, exposure time and ammonium chloride concentration in the formation and growth evolution of a stable coating of iron-aluminum and iron-aluminum-nickel on the T91 steel surface, which was effectively deposited at a temperature of 700°C and an exposure period of 9 hours. The coating formed on the T91 steel surface could play a protective role towards the material by acting as a physical barrier between the alloy and other corrosive species in high temperature operated systems.

  20. Evaluation of mechanical strength and hydrate products evolution of calcium aluminate cement, for endodontic applications

    International Nuclear Information System (INIS)

    Luz, A.P.; Borba, N.Z.; Pandolfelli, V.C.

    2011-01-01

    Mineral trioxide aggregate (MTA) is the most used retrograde filling cement in the endodontic area. Nevertheless, although its composition is similar to the conventional Portland cement, its high cost, long setting time and low mechanical strength have led to a continuous search for new alternative materials. Considering these aspects, the mechanical strength and crystalline phase evolution of a calcium aluminate cement (CAC), during its hydration process, have been evaluated in this work aiming to apply such material for endodontic treatments. Secar 71 cement samples were prepared and kept in contact with water or SBF (simulated body fluid) during 15 days at 37 deg C. Compressive strength, apparent porosity, X ray diffraction and thermogravimetric tests were carried out for the samples evaluation after 1, 3, 7 and 15 days. The main identified phases were CAH 10 , C 2 AH 8 , C 3 AH 6 and AH 3 . Moreover, when in the presence of SBF, some changes in the amount of the hydrates in the CAC samples were observed, which affected the mechanical behavior of the cement. (author)

  1. Analyses of Hubble Space Telescope Aluminized-Teflon Insulation Retrieved After 19 Years of Space Exposure

    Science.gov (United States)

    deGroh, Kim K.; Waters, Deborah L.; Mohammed, Jelila S.; Perry, Bruce A.; Banks, Bruce A.

    2012-01-01

    Since its launch in April 1990, the Hubble Space Telescope (HST) has made many important observations from its vantage point in low Earth orbit (LEO). However, as seen during five servicing missions, the outer layer of multilayer insulation (MLI) has become successively more embrittled and has cracked in many areas. In May 2009, during the 5th servicing mission (called SM4), two MLI blankets were replaced with new insulation pieces and the space-exposed MLI blankets were retrieved for degradation analyses by teams at NASA Glenn Research Center (GRC) and NASA Goddard Space Flight Center (GSFC). The MLI blankets were from Equipment Bay 8, which received direct sunlight, and Equipment Bay 5, which received grazing sunlight. Each blanket contained a range of unique regions based on environmental exposure and/or physical appearance. The retrieved MLI blanket s aluminized-Teflon (DuPont) fluorinated ethylene propylene (Al-FEP) outer layers have been analyzed for changes in optical, physical, and mechanical properties, along with space induced chemical and morphological changes. When compared to pristine material, the analyses have shown how the Al-FEP was severely affected by the space environment. This paper reviews tensile properties, solar absorptance, thermal emittance, x-ray photoelectron spectroscopy (XPS) data and atomic oxygen erosion values of the retrieved HST blankets after 19 years of space exposure.

  2. Formation of microstructural features in hot-dip aluminized AISI 321 stainless steel

    Science.gov (United States)

    Huilgol, Prashant; Rajendra Udupa, K.; Udaya Bhat, K.

    2018-02-01

    Hot-dip aluminizing (HDA) is a proven surface coating technique for improving the oxidation and corrosion resistance of ferrous substrates. Although extensive studies on the HDA of plain carbon steels have been reported, studies on the HDA of stainless steels are limited. Because of the technological importance of stainless steels in high-temperature applications, studies of their microstructural development during HDA are needed. In the present investigation, the HDA of AISI 321 stainless steel was carried out in a pure Al bath. The microstructural features of the coating were studied using scanning electron microscopy and transmission electron microscopy. These studies revealed that the coating consists of two regions: an Al top coat and an aluminide layer at the interface between the steel and Al. The Al top coat was found to consist of intermetallic phases such as Al7Cr and Al3Fe dispersed in an Al matrix. Twinning was observed in both the Al7Cr and the Al3Fe phases. Furthermore, the aluminide layer comprised a mixture of nanocrystalline Fe2Al5, Al7Cr, and Al. Details of the microstructural features are presented, and their formation mechanisms are discussed.

  3. Elastic Properties of Tricalcium Aluminate from High-Pressure Experiments and First-Principles Calculations

    KAUST Repository

    Moon, Juhyuk

    2012-06-04

    The structure and elasticity of tricalcium aluminate (C 3A) have been experimentally and theoretically studied. From high-pressure X-ray diffraction experiments, the bulk modulus of 102(6) and 110(3) GPa were obtained by fitting second- and third-order finite strain equation of state, respectively. First-principles calculations with a generalized gradient approximation gave an isotropic bulk modulus of 102.1 GPa and an isothermal bulk modulus of 106.0 GPa. The static calculations using the exchange-correlation functional show an excellent agreement with the experimental measurements. Based on the agreement, accurate elastic constants and other elastic moduli were computed. The slight difference of behavior at high pressure can be explained by the infiltration of pressure-transmitting silicone oil into structural holes in C 3A. The computed elastic and mechanical properties will be useful in understanding structural and mechanical properties of cementitious materials, particularly with the increasing interest in the advanced applications at the nanoscale. © 2012 The American Ceramic Society.

  4. Diffusion of lithium-6 isotopes in lithium aluminate ceramics using neutron depth profiling

    Energy Technology Data Exchange (ETDEWEB)

    McWhinney, H.G. (Prairie View A and M Univ., TX (United States). Dept. of Chemistry); James, W.D. (Texas A and M Univ., College Station, TX (United States). Center for Chemical Characterization and Analysis); Schweikert, E.A. (Texas A and M Univ., College Station, TX (United States). Center for Chemical Characterization and Analysis); Williams, J.R. (Prairie View A and M Univ., TX (United States). Dept. of Chemistry); Hollenberg, G. (Battelle Pacific Northwest Labs., Nuclear Reactor Material Group, US Dept. of Energy, Hanford, WA (United States)); Welsh, J. (Texas A and M Univ., College Station, TX (United States). Center for Chemical Characterization and Analysis); Sereatan, W. (Prairie View A and M Univ., TX (United States). Dept. of Chemistry)

    1993-07-01

    Lithium Ceramics offer tremendous potential as a source for the production of tritium ([sup 3]H) for fusion power reactors. Their successful application will depend to a great extent upon the diffusion properties of the [sup 6]Li within the matrix. Consequently knowledge of [sup 6]Li concentration gradients in the ceramic matrices is an important requirement in the continued development of the technology. In this investigation, the neutron depth profile (NDP) technique has been applied to the study of concentration profiles of [sup 6]Li in lithium aluminate ceramics, doped with 1.8%, 50% and 95% [sup 6]Li isotopic concentrations. Specimen for analysis were prepared at Battelle (PNL) as pellet discs. Samples for diffusion studies were arranged as diffusion couples in the following manner: 1.8% [sup 6]Li discs/85% [sup 6]Li powder. Experiments were performed at the Texas A and M Nuclear Science Center Reactor Building, utilizing 1 MW equivalent thermal neutron fluxes 3x10[sup 11] n/m[sup 2] s. The depth probed by the technique is approximately 15 [mu]m. Diffusion coefficients are in the range of 2.1x10[sup -12] to 7.0x10[sup -11] m[sup 2] s[sup -1] for 1.8% [sup 6]Li-doped ceramics annealed at 1200 and 1400 C, for 4 to 48-h anneal times. (orig.)

  5. Diclofenac sodium overdose

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/002630.htm Diclofenac sodium overdose To use the sharing features on this page, please enable JavaScript. Diclofenac sodium is a prescription medicine used to relieve pain ...

  6. Sodium Ferric Gluconate Injection

    Science.gov (United States)

    Sodium ferric gluconate injection is used to treat iron-deficiency anemia (a lower than normal number of ... are also receiving the medication epoetin (Epogen, Procrit). Sodium ferric gluconate injection is in a class of ...

  7. Naproxen sodium overdose

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/002507.htm Naproxen sodium overdose To use the sharing features on this page, please enable JavaScript. Naproxen sodium is a nonsteroidal anti-inflammatory drug (NSAID) used ...

  8. Sodium carbonate poisoning

    Science.gov (United States)

    Sodium carbonate (known as washing soda or soda ash) is a chemical found in many household and ... products. This article focuses on poisoning due to sodium carbonate. This article is for information only. Do ...

  9. Sodium hydroxide poisoning

    Science.gov (United States)

    Sodium hydroxide is a very strong chemical. It is also known as lye and caustic soda. This ... poisoning from touching, breathing in (inhaling), or swallowing sodium hydroxide. This article is for information only. Do ...

  10. Docusate Sodium and Pregnancy

    Science.gov (United States)

    ... live chat Live Help Fact Sheets Share Docusate Sodium Friday, 01 April 2016 In every pregnancy, a ... This sheet talks about whether exposure to docusate sodium may increase the risk for birth defects over ...

  11. Sodium pumping: pump problems

    International Nuclear Information System (INIS)

    Guer, M.; Guiton, P.

    Information on sodium pumps for LMFBR type reactors is presented concerning ring pump design, pool reactor pump design, secondary pumps, sodium bearings, swivel joints of the oscillating annulus, and thermal shock loads

  12. ELTA: Citatrademark: Sodium measurement

    International Nuclear Information System (INIS)

    Mauvais, O.

    2002-01-01

    ELTA is pleased to present its last model of Sodium analyzers: CITA 2340: Automatically controlled sodium meter, integrating more automation and performances results respecting costs and wastes reduction. (authors)

  13. Electrochemical properties of polyaniline-modified sodium vanadate nanomaterials

    International Nuclear Information System (INIS)

    Reddy Channu, V.S.; Holze, Rudolf; Yeo, In-Hyeong; Mho, Sun-il; Kalluru, Rajamohan R.

    2011-01-01

    Sodium vanadate nanomaterials were synthesized at different pH-values of a sodium hydroxide solution of vanadium pentoxide. Polyaniline-modified sodium vanadate nanomaterials were prepared at room temperature and at 3 C by a chemical polymerization method. The crystal structure and phase purity of the samples have been examined by powder XRD. The samples were identified as HNaV 6 O 16 .4H 2 O and Na 1.1 V 3 O 7.9 . The electrochemical measurements show that polyaniline-modified sodium vanadate hydrated nanomaterials provide higher current density than the sodium vanadate nanomaterials. (orig.)

  14. Liquid sodium technology research

    International Nuclear Information System (INIS)

    Kim, W.C.; Lee, Y.W.; Nam, H.Y.; Chun, S.Y.; Kim, J.; Won, S.Y.

    1982-01-01

    This report describes the technology of impurity control and measurement of liquid sodium, problems associated with material degradation and change of heat transfer characteristics in liquid sodium, and the conceptual design of multipurpose sodium test loop. Discussion and the subsequent analysis are also made with regard to the test results for the sodium-H 2 0 reaction and its effects on the system. (author)

  15. Sodium sieving in children.

    NARCIS (Netherlands)

    Rusthoven, E.; Krediet, R.T.; Willems, J.L.; Monnens, L.A.H.; Schroder, C.H.

    2005-01-01

    Sodium sieving is a consequence of dissociation between the amount of water and sodium transported over the peritoneal membrane. This dissociation occurs in the presence of aquaporin-mediated water transport. Sieving of sodium can be used as a rough measure for aquaporin-mediated water transport.

  16. Sodium sieving in children

    NARCIS (Netherlands)

    Rusthoven, Esther; Krediet, Raymond T.; Willems, Hans L.; Monnens, Leo A.; Schröder, Cornelis H.

    2005-01-01

    Sodium sieving is a consequence of dissociation between the amount of water and sodium transported over the peritoneal membrane. This dissociation occurs in the presence of aquaporin-mediated water transport. Sieving of sodium can be used as a rough measure for aquaporin-mediated water transport.

  17. SrAl12O19 thin films by chemical solution deposition and their use as buffer layers for oriented growth of hexagonal ferrites

    Czech Academy of Sciences Publication Activity Database

    Buršík, Josef; Uhrecký, Róbert; Kaščáková, Dorota; Kužel, R.; Holý, V.; Dopita, M.

    2016-01-01

    Roč. 616, OCT (2016), s. 228-237 ISSN 0040-6090 R&D Projects: GA ČR(CZ) GA14-18392S Institutional support: RVO:61388980 Keywords : Chemical solution deposition * Hexagonal aluminates * Hexagonal ferrites Subject RIV: CA - Inorganic Chemistry Impact factor: 1.879, year: 2016

  18. Effects of sodium citrate and acid citrate dextrose solutions on cell counts and growth factor release from equine pure-platelet rich plasma and pure-platelet rich gel.

    Science.gov (United States)

    Giraldo, Carlos E; Álvarez, María E; Carmona, Jorge U

    2015-03-14

    There is a lack information on the effects of the most commonly used anticoagulants for equine platelet rich plasmas (PRPs) elaboration on cell counts and growth factor release from platelet rich gels (PRGs). The aims of this study were 1) to compare the effects of the anticoagulants sodium citrate (SC), acid citrate dextrose solution A (ACD-A) and ACD-B on platelet (PLT), leukocyte (WBC) and on some parameters associated to platelet activation including mean platelet volume (MPV) and platelet distribution width (PDW) between whole blood, pure PRP (P-PRP) and platelet-poor plasma (PPP); 2) to compare transforming growth factor beta 1 (TGF-β(1)) and platelet-derived growth factor isoform BB (PDGF-BB) concentrations in supernatants from pure PRG (P-PRG), platelet-poor gel (PPG), P-PRP lysate (positive control) and plasma (negative control); 3) to establish the possible correlations between all the studied cellular and molecular parameters. In all cases the three anticoagulants produced P-PRPs with significantly higher PLT counts compared with whole blood and PPP. The concentrations of WBCs were similar between P-PRP and whole blood, but significantly lower in PPP. The type of anticoagulant did not significantly affect the cell counts for each blood component. The anticoagulants also did not affect the MPV and PDW parameters. Independently of the anticoagulant used, all blood components presented significantly different concentrations of PDGF-BB and TGF-β(1). The highest growth factor (GF) concentrations were observed from P-PRP lysates, followed by PRG supernatants, PPP lysates, PPG supernatants and plasma. Significant correlations were observed between PLT and WBC counts (ρ = 0.80), PLT count and TGF-β(1) concentration (ρ = 0.85), PLT count and PDGF-BB concentration (ρ = 0.80) and PDGF-BB and TGF-β(1) concentrations (ρ = 0.75). The type of anticoagulant was not correlated with any of the variables evaluated. The anticoagulants did not

  19. Sodium safety manual

    International Nuclear Information System (INIS)

    Hayes, D.J.; Gardiner, R.L.

    1980-09-01

    The sodium safety manual is based upon more than a decade of experience with liquid sodium at Berkeley Nuclear Laboratories (BNL). It draws particularly from the expertise and experience developed in the course of research work into sodium fires and sodium water reactions. It draws also on information obtained from the UKAEA and other sodium users. Many of the broad principles will apply to other Establishments but much of the detail is specific to BNL and as a consequence its application at other sites may well be limited. Accidents with sodium are at best unpleasant and at worst lethal in an extremely painful way. The object of this manual is to help prevent sodium accidents. It is not intended to give detailed advice on specific precautions for particular situations, but rather to set out the overall strategy which will ensure that sodium activities will be pursued safely. More detail is generally conveyed to staff by the use of local instructions known as Sodium Working Procedures (SWP's) which are not reproduced in this manual although a list of current SWP's is included. Much attention is properly given to the safe design and operation of larger facilities; nevertheless evidence suggests that sodium accidents most frequently occur in small-scale work particularly in operations associated with sodium cleaning and special care is needed in all such cases. (U.K.)

  20. Report of sodium cavitation

    International Nuclear Information System (INIS)

    Murai, Hitoshi; Shima, Akira; Oba, Toshisaburo; Kobayashi, Ryoji; Hashimoto, Hiroyuki

    1975-01-01

    The damage of components for LMFBRs due to sodium cavitation is serious problem. This report summarizes the following items, (1) mechanism of the incipience of sodium cavitation, (2) damage due to sodium cavitation, (3) detection method for sodium cavitation, and (4) estimation method for sodium cavitation by the comparison with water cavitation. Materials were collected from the reports on liquid metal cavitation, sodium cavitation and water cavitation published from 1965 to now. The mechanism of the incipience of sodium cavitation cavitation parameters (mean location, distributed amount or occurrence aspect and stability), experiment of causing cavitation with Venturi tube, and growth of bubbles within superheated sodium. The sodium cavitation damage was caused by magnetostriction vibration method and with Venturi tube. The state of damage was investigated with the cavitation performance of a sodium pump, and the damage was examined in view of the safety of LMFBR plants. Sodium cavitation was detected with acoustic method, radiation method, and electric method. The effect of physical property of liquid on incipient cavitation was studied. These are thermodynamic effect based on quasistatic thermal equilibrium condition and the effect of the physical property of liquid based on bubble dynamics. (Iwase, T.)