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Sample records for acidic chloride solutions

  1. Hafnium extraction from acidic chloride solutions by Cyanex 923

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-08-01

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

  2. REMOVAL OF CHLORIDE FROM ACIDIC SOLUTIONS USING NO2

    International Nuclear Information System (INIS)

    Chloride (Cl-) salt processing in strong acids is used to recycle plutonium (Pu) from pyrochemical residues. The Savannah River National Laboratory (SRNL) is studying the potential application of nitrogen dioxide (NO2) gas to effectively convert dissolved pyrochemical salt solutions to chloride-free solutions and improve recovery operations. An NO2 sparge has been shown to effectively remove Cl- from solutions containing 6-8 M acid (H+) and up to 5 M Cl-. Chloride removal occurs as a result of the competition of at least two reactions, one which is acid-dependent. Below 4 M H+, NO2 reacts with Cl- to produce nitrosyl chloride (ClNO). Between 6 M and 8 M H+, the reaction of hydrochloric acid (HCl) with nitric acid (HNO3), facilitated by the presence of NO2, strongly affects the rate of Cl- removal. The effect of heating the acidic Cl- salt solution without pre-heating the NO2 gas has minimal effect on Cl- removal rates when the contact times between NO2 and the salt solution are on the order of seconds

  3. Indium sulfide precipitation from hydrochloric acid solutions of calcium and sodium chlorides

    International Nuclear Information System (INIS)

    The effect of precipitation duration, acid concentration, indium complexing with chloride ions on the process of indium sulfide chemical precipitation in hydrochloric acid solutions, precipitate composition and dispersity are studied. It is established that indium sulfide solubility increases in solutions with acid concentration exceeding 0.40-0.45 mol/l. Calcium and indium chloride addition to diluted hydrochloric solutions greatly increases the solubility of indium sulfide. The effect of calcium chloride on In2S3 solubility is higher than that of sodium chloride

  4. Chloride stress corrosion cracking of Alloy 600 in boric acid solutions

    Energy Technology Data Exchange (ETDEWEB)

    Berge, Ph. [Electricite de France, 92 - Paris la Defense (France); Noel, D.; Gras, J.M.; Prieux, B. [Electricite de France, 77 - Moret-sur-Loing (France). Direction des Etudes et Recherches

    1997-10-01

    The high nickel austenitic alloys are generally considered to have good resistance to chloride stress corrosion cracking. In the standard boiling magnesium chloride solution tests, alloys with more than 40% nickel are immune. Nevertheless, more recent data show that cracking can occur in both Alloys 600 and 690 if the solution is acidified. In other low pH media, such as boric acid solution at 100 deg C, transgranular and intergranular cracking are observed in Alloy 600 in the presence of minor concentrations of sodium chloride (2g/I). In concentrated boric acid at higher temperatures (250 and 290 deg C), intergranular cracking also occurs, either when the chloride concentration is high, or at low chloride contents and high oxygen levels. The role of pH and a possible specific action of boric acid are discussed, together with the influence of electrochemical potential. (author) 21 refs.

  5. Chloride stress corrosion cracking of Alloy 600 in boric acid solutions

    International Nuclear Information System (INIS)

    The high nickel austenitic alloys are generally considered to have good resistance to chloride stress corrosion cracking. In the standard boiling magnesium chloride solution tests, alloys with more than 40% nickel are immune. Nevertheless, more recent data show that cracking can occur in both Alloys 600 and 690 if the solution is acidified. In other low pH media, such as boric acid solution at 100 deg C, transgranular and intergranular cracking are observed in Alloy 600 in the presence of minor concentrations of sodium chloride (2g/I). In concentrated boric acid at higher temperatures (250 and 290 deg C), intergranular cracking also occurs, either when the chloride concentration is high, or at low chloride contents and high oxygen levels. The role of pH and a possible specific action of boric acid are discussed, together with the influence of electrochemical potential. (author)

  6. Leaching of complex sulphide concentrate in acidic cupric chloride solutions

    Institute of Scientific and Technical Information of China (English)

    M. TCHOUMOU; M. ROYNETTE

    2007-01-01

    The chemical analysis of a complex sulphide concentrate by emission spectrometry and X-ray diffraction shows that it contains essentially copper, lead, zinc and iron in the form of chalcopyrite, sphalerite and galena. A small amount of pyrite is also present in the ore but does not be detected with X-ray diffraction. The cupric chloride leaching of the sulphide concentrate at various durations and solid/liquid ratios at 100 ℃ shows that the rate of dissolution of the ore is the fastest in the first several hours, and after 12 h it does not evolve significantly. If oxygen is excluded from the aqueous cupric chloride solution during the leaching experiment at 100 ℃, the pyrite in the ore will not be leached. The determination of principal dissolved metals in the leaching liquor by flame atomic absorption spectrometry, and the chemical analysis of solid residues by emission spectrometry and X-ray diffraction allow to conclude that the rate of dissolution of the minerals contained in the complex sulphide concentrate are in the order of galena>sphalerite>chalcopyrite.

  7. The initial behaviour of freshly etched copper in modertely acid, aerated chloride solutions

    DEFF Research Database (Denmark)

    Bech-Nielsen, Gregers; Jaskula, M.; Chorkendorff, Ib;

    2002-01-01

    When freshly etched samples of various types of copper were exposed in moderately acid, aerated chloride solutions, two phenomena were observed. First the corrosion potential and the pH of the solution decreased over a shorter time, then the potential increased over a long period (600-1500 min), ...

  8. Stress corrosion cracking of AISI 321 stainless steel in acidic chloride solution

    Indian Academy of Sciences (India)

    Yanliang Huang

    2002-02-01

    The stress corrosion cracking (SCC) of AISI 321 stainless steel in acidic chloride solution was studied by slow strain rate (SSR) technique and fracture mechanics method. The fractured surface was characterized by cleavage fracture. In order to clarify the SCC mechanism, the effects of inhibitor KI on SCC behaviour were also included in this paper. A study showed that the inhibition effects of KI on SCC were mainly attributed to the anodic reaction of the corrosion process. The results of strain distribution in front of the crack tip of the fatigue pre-cracked plate specimens in air, in the blank solution (acidic chloride solution without inhibitor KI) and in the solution added with KI measured by speckle interferometry (SPI) support the unified mechanism of SCC and corrosion fatigue cracking (CFC).

  9. Corrosion Behavior of Alloy 22 in Oxalic Acid and Sodium Chloride Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Day, S D; Whalen, M T; King, K J; Hust, G A; Wong, L L; Estill, J C; Rebak, R B

    2003-06-24

    Nickel based Alloy 22 (NO6022) is extensively used in aggressive industrial applications, especially due to its resistance to localized corrosion and stress corrosion cracking in high chloride environments. The purpose of this work was to characterize the anodic behavior of Alloy 22 in oxalic acid solution and to compare its behavior to sodium chloride (NaCl) solutions. Standard electrochemical tests such as polarization resistance and cyclic polarization were used. Results show that the corrosion rate of Alloy 22 in oxalic acid solutions increased rapidly as the temperature and the acid concentration increased. Extrapolation studies show that even at a concentration of 10{sup -4}M oxalic acid, the corrosion rate of Alloy 22 would be higher in oxalic acid than in 1 M NaCl solution. Alloy 22 was not susceptible to localized corrosion in oxalic acid solutions. Cyclic polarization tests in 1 M NaCl showed that Alloy 22 was susceptible to crevice corrosion at 90 C but was not susceptible at 60 C.

  10. Ternary solution of sodium chloride, succinic acid and water; surface tension and its influence on cloud droplet activation

    OpenAIRE

    J. Vanhanen; Hyvärinen, A.-P.; Anttila, T.; T. Raatikainen; Viisanen, Y; H. Lihavainen

    2008-01-01

    Surface tension of ternary solution of sodium chloride, succinic acid and water was measured as a function of both composition and temperature by using the capillary rise technique. Both sodium chloride and succinic acid are found in atmospheric aerosols, the former being main constituent of marine aerosol. Succinic acid was found to decrease the surface tension of water already at very low concentrations. Sodium chloride increased the surface tension linearly as a function of the concentrati...

  11. Ternary solution of sodium chloride, succinic acid and water ? surface tension and its influence on cloud droplet activation

    OpenAIRE

    H. Lihavainen; Viisanen, Y; Anttila, T.; A.-P. Hyvärinen; J. Vanhanen

    2008-01-01

    Surface tension of ternary solution of sodium chloride, succinic acid and water was measured as a function of both composition and temperature by using the capillary rise technique. Both sodium chloride and succinic acid are found in atmospheric aerosols, the former being main constituent of marine aerosol. Succinic acid was found to decrease the surface tension of water already at very low concentrations. Sodium chloride increased the surface tension linearly as a function of the concentrati...

  12. Efficient acetylation of primary amines and amino acids in environmentally benign brine solution using acetyl chloride

    Indian Academy of Sciences (India)

    Kaushik Basu; Suchandra Chakraborty; Achintya Kumar Sarkar; Chandan Saha

    2013-05-01

    Acetyl chloride is one of the most commonly available and cheap acylating agent but its high reactivity and concomitant instability in water precludes its use to carry out acetylation in aqueous medium. The present methodology illustrates the efficient acetylation of primary amines and amino acids in brine solution by means of acetyl chloride under weakly basic condition in the presence of sodium acetate and/or triethyl amine followed by trituration with aqueous saturated bicarbonate solution. This effort represents the first efficient use of this most reactive but cheap acetylating agent to acetylate amines in excellent yields in aqueous medium. This is a potentially useful green chemical transformation where reaction takes place in environment-friendly brine solution leading to easy work-up and isolation of the amide derivatives. Mechanistic rationale of this methodology is also important.

  13. Protection of copper surface with phytic acid against corrosion in chloride solution.

    Science.gov (United States)

    Peca, Dunja; Pihlar, Boris; Ingrid, Milošev

    2014-01-01

    Phytic acid (inositol hexaphosphate) was tested as a corrosion inhibitor for copper in 3% sodium chloride. Phytic acid is a natural compound derived from plants, it is not toxic and can be considered as a green inhibitor. Electrochemical methods of linear polarization and potentiodynamic polarization were used to study the electrochemical behaviour and evaluate the inhibition effectiveness. To obtain the optimal corrosion protection the following experimental conditions were investigated: effect of surface pre-treatment (abrasion and three procedures of surface roughening), pre-formation of the layer of phytic acid, time of immersion and concentration of phytic acid. To evaluate the surface pre-treatment procedures the surface roughness and contact angle were measured. Optimal conditions for formation of phytic layer were selected resulting in the inhibition effectiveness of nearly 80%. Morphology and composition of the layer were further studied by scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy. The layer of phytic acid with thickness in the nanometer range homogeneously covers the copper surface. The obtained results show that this natural compound can be used as a mildly effective corrosion inhibitor for copper in chloride solution. PMID:25286201

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

    Science.gov (United States)

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

    2015-11-01

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

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

    Science.gov (United States)

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

    2015-05-01

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

  16. EIS study on pitting corrosion of 7150 aluminum alloy in sodium chloride and hydrochloric acid solution

    Energy Technology Data Exchange (ETDEWEB)

    Peng, G.S; Chen, K.H.; Fang, H.C.; Chao, H.; Chen, S.Y. [State Key Laboratory for Powder Metallurgy, Central South University, Hunan (China)

    2010-09-15

    The pitting corrosion behavior of 7150 aluminum alloy was studied by electrochemical impedance spectroscopy (EIS) in the sodium chloride and hydrochloric acid solution. Based on EIS features and corrosion morphologies as well as corrosion potential, the process of pitting corrosion could be clearly divided into four stages: at the first stage, the Nyquist diagram was composed of two overlapping capacitive loops at the high-medial frequency and one inductive loop at the low frequency. At the second stage (metastable pits developing stage), there existed one small capacitive loop at the high frequency and one big capacitive loop at the medial frequency. At the third stage (stable pits developing stage), two time constants were more clearly distinguished, corresponding to two obvious capacitive loops. At the fourth stage, there appeared one capacitive loop, attributing to uniform corrosion. An equivalent circuit was designed to fit EIS, and the experimental results and the fitted results had good correspondence. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-01-01

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

  18. Ternary solution of sodium chloride, succinic acid and water; surface tension and its influence on cloud droplet activation

    Directory of Open Access Journals (Sweden)

    J. Vanhanen

    2008-08-01

    Full Text Available Surface tension of ternary solution of sodium chloride, succinic acid and water was measured as a function of both composition and temperature by using the capillary rise technique. Both sodium chloride and succinic acid are found in atmospheric aerosols, the former being main constituent of marine aerosol. Succinic acid was found to decrease the surface tension of water already at very low concentrations. Sodium chloride increased the surface tension linearly as a function of the concentration. Surface tensions of both binary solutions agreed well with the previous measurements. Succinic acid was found to lower the surface tension even if sodium chloride is present, indicating that succinic acid, as a surface active compound, tends to concentrate to the surface. An equation based on thermodynamical relations was fitted to the data and extrapolated to the whole concentration range by using estimated surface tensions for pure compounds. As a result, we obtained an estimate of surface tensions beyond solubility limits in addition to a fit to the experimental data. The parameterization can safely be used at temperatures from 10 to 30°C. These kinds of parameterizations are important for example in atmospheric nucleation models. To investigate the influence of surface tension on cloud droplet activation, the surface tension parameterization was included in an adiabatic air parcel model. Usually in cloud models the surface tension of pure water is used. Simulations were done for characteristic marine aerosol size distributions consisting of the considered ternary mixture. We found that by using the surface tension of pure water, the amount of activated particles is underestimated up to 8% if particles contain succinic acid and overestimated it up to 8% if particles contain only sodium chloride. The surface tension effect was found to increase with increasing updraft velocity.

  19. Corrosion Behavior of Alloy 22 in Chloride Solutions Containing Organic Acids

    Energy Technology Data Exchange (ETDEWEB)

    Carranza, R M; Giordano, C M; Rodr?guez, M A; Rebak, R B

    2005-11-04

    Alloy 22 (N06022) is a nickel based alloy containing alloying elements such as chromium, molybdenum and tungsten. It is highly corrosion resistant both under reducing and under oxidizing conditions. Electrochemical studies such as electrochemical impedance spectroscopy (EIS) were performed to determine the corrosion behavior of Alloy 22 in 1M NaCl solutions at various pH values from acidic to neutral at 90 C. Tests were also carried out in NaCl solutions containing oxalic acid or acetic acid. It is shown that the corrosion rate of Alloy 22 was higher in a solution containing oxalic acid than in a solution of the same pH acidified with HCl. Acetic acid was not corrosive to Alloy 22. The corrosivity of oxalic acid was attributed to its capacity to form stable complex species with metallic cations from Alloy 22.

  20. Corrosion Mitigation of Copper in Acidic Chloride Pickling Solutions by 2-Amino-5-ethyl-1,3,4-thiadiazole

    Science.gov (United States)

    Sherif, El-Sayed M.

    2010-08-01

    Corrosion of copper in acidic chloride pickling solutions of 0.5 M HCl and its mitigation by 2-amino-5-ethyl-1,3,4-thiadiazole (AETDA) have been investigated using potentiodynamic polarization, chronoamperometry, electrochemical impedance spectroscopy (EIS), and weight-loss measurements. The study was also complemented by scanning electron microscopy (SEM), energy dispersive x-ray (EDX), and UV-Visible absorption spectroscopy investigations. The presence of AETDA and the increase of its concentration in the chloride solutions greatly decreased the corrosion rate and increased the surface and polarization resistances of copper as indicated by the electrochemical measurements. Weight-loss data also indicated that AETDA decreases the dissolution of copper coupons in the studied chloride solution. SEM/EDX investigations showed that AETDA molecules are strongly adsorbed onto copper surface. The UV-Visible absorption spectra confirmed that AETDA molecules suppress the corrosion of copper via their interactions with the copper surface via their adsorption then formation of AETDA-Cu complex.

  1. Effects of applied potential on the stress corrosion cracking behavior of 7003 aluminum alloy in acid and alkaline chloride solutions

    Science.gov (United States)

    Zhang, Xiao-yan; Song, Ren-guo; Sun, Bin; Lu, Hai; Wang, Chao

    2016-07-01

    Potentiodynamic polarization tests and slow strain rate test (SSRT) in combination with fracture morphology observations were conducted to investigate the stress corrosion cracking (SCC) behavior of 7003 aluminum alloy (AA7003) in acid and alkaline chloride solutions under various applied potentials ( E a). The results show that AA7003 is to a certain extent susceptible to SCC via anodic dissolution (AD) at open-circuit potential (OCP) and is highly susceptible to hydrogen embrittlement (HE) at high negative E a in the solutions with pH levels of 4 and 11. The susceptibility increases with negative shift in the potential when E a is less than -1000 mV vs. SCE. However, the susceptibility distinctly decreases because of the inhibition of AD when E a is equal to -1000 mV vs. SCE. In addition, the SCC susceptibility of AA7003 in the acid chloride solution is higher than that in the alkaline solution at each potential. Moreover, the effect of hydrogen on SCC increases with increasing hydrogen ion concentration.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-09-01

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

  3. A new dioxime corrosion inhibitor for the protection and conservation of copper: synthesis, characterization and evaluation in acidic chloride solution

    Science.gov (United States)

    Abu-Baker, Ahmad N.; Al-Qudah, Mahmoud A.

    2016-08-01

    This study aimed to investigate a new dioxime compound as a corrosion inhibitor for copper. The compound (4,6-dihydroxy benzene-1,3-dicarbaldehyde dioxime) was synthesized and characterized by nuclear magnetic resonance spectroscopy. Electrochemical impedance spectroscopy and potentiodynamic polarization measurements were used to compare the dioxime compound with benzotriazole for their effectiveness as corrosion inhibitors for copper in 0.1 M HCl solution. Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) were used to investigate the bonding mechanisms and morphological changes of the two inhibitors on the copper surface. The electrochemical techniques showed that the new dioxime compound was more effective than benzotriazole in inhibiting copper corrosion in the acidic chloride medium. The FTIR and SEM results indicated that the dioxime compound was able to coordinate with copper ions and formed a protective film on the copper surface. It was concluded that the new dioxime compound proved effectiveness to be used as a corrosion inhibitor for the protection and conservation of copper.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-06-01

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

  5. Copper Leaching from Copper Residue with Oxygen in Sulfuric Acid/Chloride Solution DENG Tong 1,%在硫酸/氯化物深液中用氧气浸出铜渣中的铜

    Institute of Scientific and Technical Information of China (English)

    邓彤; 文震

    2000-01-01

    Leaching of a copper residue, produced by selected oxidation leaching of a nickel matte, in oxygenated sulfuric acid solution with the participation of chloride was investigated. The effects of quantity of chloride, flowrate of oxygen, concentration of sulfuric acid and temperature were discussed as leaching variables. Addition of chloride in small amount into the leach slurry was justified in enhancing copper leaching from the residue.

  6. Hydrazino-methoxy-1,3,5-triazine Derivatives’ Excellent Corrosion Organic Inhibitors of Steel in Acidic Chloride Solution

    Directory of Open Access Journals (Sweden)

    Ayman El-Faham

    2016-06-01

    Full Text Available The corrosion inhibition performance of 2-hydrazino-4,6-dimethoxy-1,3,5-tirazine (DMeHT, 2,4-dihydrazino-6-methoxy-1,3,5-triaizine (DHMeT, and 2,4,6-tridydrazino-1,3,5-triaizne (TH3 on steel corrosion in acidic media was examined using electrochemical techniques. The results showed 2,4-Ddihydrazino-6-methoxy-1,3,5-triaizine (DHMeT gave the best corrosion protection performance among the other hydrazino derivatives even at a low concentration of 25 ppm (95%. The number of hydrazino groups play an important role in the corrosion inhibition, where the two hydrazine groups increased the electrostatic interactions between the protonated tested compounds, the negatively charged steel surface resulted from the adsorption of the chloride anions, and the presence of the methoxy group made the compound more reliable for formation of film protection on the surface of steel through the lone pair of oxygen atoms. Electrochemical Impedance Spectroscopy (EIS measurements suggested that the corrosion process of steel in presence of the hydrazino-s-triazine derivatives (TH3, DMeHT and DHMeT were being controlled by the charge transfer reaction. Polarization curves indicated that the examined TH3, DMeHT and DHMeT behaved as mixed type inhibitors.

  7. Hydrazino-methoxy-1,3,5-triazine Derivatives' Excellent Corrosion Organic Inhibitors of Steel in Acidic Chloride Solution.

    Science.gov (United States)

    El-Faham, Ayman; Osman, Sameh M; Al-Lohedan, Hamad A; El-Mahdy, Gamal A

    2016-06-01

    The corrosion inhibition performance of 2-hydrazino-4,6-dimethoxy-1,3,5-tirazine (DMeHT), 2,4-dihydrazino-6-methoxy-1,3,5-triaizine (DHMeT), and 2,4,6-tridydrazino-1,3,5-triaizne (TH₃) on steel corrosion in acidic media was examined using electrochemical techniques. The results showed 2,4-Ddihydrazino-6-methoxy-1,3,5-triaizine (DHMeT) gave the best corrosion protection performance among the other hydrazino derivatives even at a low concentration of 25 ppm (95%). The number of hydrazino groups play an important role in the corrosion inhibition, where the two hydrazine groups increased the electrostatic interactions between the protonated tested compounds, the negatively charged steel surface resulted from the adsorption of the chloride anions, and the presence of the methoxy group made the compound more reliable for formation of film protection on the surface of steel through the lone pair of oxygen atoms. Electrochemical Impedance Spectroscopy (EIS) measurements suggested that the corrosion process of steel in presence of the hydrazino-s-triazine derivatives (TH₃, DMeHT and DHMeT) were being controlled by the charge transfer reaction. Polarization curves indicated that the examined TH₃, DMeHT and DHMeT behaved as mixed type inhibitors.

  8. Hydrazino-methoxy-1,3,5-triazine Derivatives' Excellent Corrosion Organic Inhibitors of Steel in Acidic Chloride Solution.

    Science.gov (United States)

    El-Faham, Ayman; Osman, Sameh M; Al-Lohedan, Hamad A; El-Mahdy, Gamal A

    2016-01-01

    The corrosion inhibition performance of 2-hydrazino-4,6-dimethoxy-1,3,5-tirazine (DMeHT), 2,4-dihydrazino-6-methoxy-1,3,5-triaizine (DHMeT), and 2,4,6-tridydrazino-1,3,5-triaizne (TH₃) on steel corrosion in acidic media was examined using electrochemical techniques. The results showed 2,4-Ddihydrazino-6-methoxy-1,3,5-triaizine (DHMeT) gave the best corrosion protection performance among the other hydrazino derivatives even at a low concentration of 25 ppm (95%). The number of hydrazino groups play an important role in the corrosion inhibition, where the two hydrazine groups increased the electrostatic interactions between the protonated tested compounds, the negatively charged steel surface resulted from the adsorption of the chloride anions, and the presence of the methoxy group made the compound more reliable for formation of film protection on the surface of steel through the lone pair of oxygen atoms. Electrochemical Impedance Spectroscopy (EIS) measurements suggested that the corrosion process of steel in presence of the hydrazino-s-triazine derivatives (TH₃, DMeHT and DHMeT) were being controlled by the charge transfer reaction. Polarization curves indicated that the examined TH₃, DMeHT and DHMeT behaved as mixed type inhibitors. PMID:27258241

  9. Determination of chloride in uranium solutions

    Energy Technology Data Exchange (ETDEWEB)

    Danse, A.; Stoch, H.; Steele, T.W.

    1967-05-15

    Thiocyanate is first removed by precipitation with a small excess of a copper solution, and the cations are removed by passing the filtrate through a cation-exchange resin. The chloride is determined in the eluate by a potentiometric titration in which silver nitrate solution is used.

  10. Catalytic Conversion of Cellulose to Levulinic Acid by Metal Chlorides

    Directory of Open Access Journals (Sweden)

    Beixiao Zhang

    2010-08-01

    Full Text Available The catalytic performance of various metal chlorides in the conversion of cellulose to levulinic acid in liquid water at high temperatures was investigated. The effects of reaction parameters on the yield of levulinic acid were also explored. The results showed that alkali and alkaline earth metal chlorides were not effective in conversion of cellulose, while transition metal chlorides, especially CrCl3, FeCl3 and CuCl2 and a group IIIA metal chloride (AlCl3, exhibited high catalytic activity. The catalytic performance was correlated with the acidity of the reaction system due to the addition of the metal chlorides, but more dependent on the type of metal chloride. Among those metal chlorides, chromium chloride was found to be exceptionally effective for the conversion of cellulose to levulinic acid, affording an optimum yield of 67 mol % after a reaction time of 180 min, at 200 °C, with a catalyst dosage of 0.02 M and substrate concentration of 50 wt %. Chromium metal, most of which was present in its oxide form in the solid sample and only a small part in solution as Cr3+ ion, can be easily separated from the resulting product mixture and recycled. Finally, a plausible reaction scheme for the chromium chloride catalyzed conversion of cellulose in water was proposed.

  11. 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)

  12. Removal of iron contaminant from zirconium chloride solution

    International Nuclear Information System (INIS)

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

  13. Green process to recover magnesium chloride from residue solution of potassium chloride production plant

    Institute of Scientific and Technical Information of China (English)

    Lin WANG; Yunliang HE; Yanfei WANG; Ying BAO; Jingkang WANG

    2008-01-01

    The green process to recover magnesium chlor-ide from the residue solution of a potassium chloride pro-duction plant, which comes from the leach solution of a potash mine in Laos, is designed and optimized. The res-idue solution contains magnesium chloride above 25 wt-%, potassium chloride and sodium chloride together below 5 wt-% and a few other ions such as Br-, SO2-4and Ca2+. The recovery process contains two steps: the previous impurity removal operation and the two-stage evapora-tion-cooling crystallization procedure to produce magnes-ium chloride. The crystallized impurity carnallite obtained from the first step is recycled to the potassium chloride plant to recover the potassium salt. The developed process is a zero discharge one and thus fulfills the requirements for green chemical industrial production. The produced magnesium chloride is up to industrial criteria.

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

    Directory of Open Access Journals (Sweden)

    Fatmir Faiku

    2012-01-01

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

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

    OpenAIRE

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

    2012-01-01

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

  16. Uranium determination by spectrophotometry, in chloride solutions, using titanium (III) as reducer

    International Nuclear Information System (INIS)

    A simple method for determining uranium in uranium (VI) solutions with the presence of uranium (IV), iron (II), and titanium (IV) in chloridic solution is described. The method comprises in uranium (VI) reduction with titanium (III), acidity adjustment and uranium (IV) spectrophotometry in hydrochloric acid 2 M. (C.G.C.)

  17. Use of saturated sodium chloride solution as a tissue fixative

    Directory of Open Access Journals (Sweden)

    A. Al-Saraj

    2010-01-01

    Full Text Available The present study was carried out to examine the capability of saturated sodium chloride solution as a fixative agent instead of formalin which is regarded as a carcinogenic material. For this purpose 3 rabbits were used and their livers, kidneys and spleens were exposed and removed. Neutral buffered formalin solution, saturated sodium chloride solution and distilled water were used as fixatives for specimens obtained from the first, second and third rabbits respectively. Routine histological technique was performed to prepare a stained histological sections for light microscopic examination. The result showed that the tissue sections which were obtained by using sodium chloride have the same histological features and without any artifacts when they compared with the results obtained using formalin fixation method. We conclude that the saturated sodium chloride solution can be used as a fixative agent in some circumstances when no any fixative agent is available.

  18. Electrodeposition of Zinc from Chloride Solution

    OpenAIRE

    NAIK, Yanjerappa Arthoba; VENKATESHA, Thimmappa Venkatarangaiah

    2002-01-01

    The electroplating of zinc is carried out in the presence of 3,4,5-Trimethoxy benzaldehyde from a chloride bath. The bath constituents are optimized through Hull cell experiments. Operating parameters such as pH, temperature, and current density are also optimized. The current efficiency and throwing power are measured at different current densities. Polarization study is carried out under galvanostatic conditions. Corrosion resistance test indicated good protection of steel by the ...

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

    Science.gov (United States)

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

    1997-04-01

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

  20. Modeling acid-gas generation from boiling chloride brines

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-11-16

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

  1. Modeling acid-gas generation from boiling chloride brines

    Directory of Open Access Journals (Sweden)

    Sonnenthal Eric

    2009-11-01

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

  2. An experiment on multibubble sonoluminescence spectra in sodium chloride solution

    Institute of Scientific and Technical Information of China (English)

    CHEN Zhan; XU JunFeng; HUANG Wei; CHEN WeiZhong; MIAO GuoQing

    2008-01-01

    We investigated experimentally the spectra of MBSL in sodium chloride water solution with krypton as dissolved gas. We observed and compared the spectra of hydroxyl ion at 310 nm and that of sodium atom at 589 nm. It has been found that under the same experimental condition, the intensity of sodium atom spectra is obviously higher than that of the hydroxyl ion spectra, and is more sensitive to the experimental condition. The krypton content, the concentration of sodium chloride solution, and the driving sound pressure obviously affect the spectra intensity in certain range.

  3. 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 m

  4. Pourbaix Diagrams for Copper in 5 m Chloride Solution

    Energy Technology Data Exchange (ETDEWEB)

    Beverskog, Bjoern [OECD Halden Reactor Project (Norway); Pettersson, Sven-Olof [ChemIT, Nykoeping (Sweden)

    2002-12-01

    Pourbaix diagrams for the copper in 5 molal chlorine at 5-100 deg C have been calculated. Predominance diagrams for dissolved copper containing species have also been calculated. Two different total concentrations of dissolved copper, 10{sup -4} and 10{sup -6} molal, have been used in the calculations. ChIoride is the predominating chlorine species in aqueous solutions. Therefore Pourbaix diagrams for chlorine can be used to discuss the effect of chloride solutions on the corrosion behavior of a metal. Presence of chloride increases the corrosion regions of copper at the expense of the immunity and passivity regions in the Pourbaix diagrams. Copper corrodes in 5 molal chloride by formation Of CuCl{sub 3}{sup 2-} in acid and alkaline solutions. At higher potentials in acid solutions CuCl{sub 3}{sup 2-} is oxidized to CuCl{sub 2}(aq), which at increasing potentials can form CuCI{sup +}, Cu{sup 2+} or CuClO{sub 3}{sup +}. Copper passivates by formation of Cu{sub 2}O(cr), CuO(cr), or CUO{sub 2} 3 Cu(OH){sub 2}(s). Cu{sub 2}O(cr) does not form at [Cu(aq)]{sub tot} = 10{sup -6} molal in 5 m C1-, which results in a corrosion area between the immunity and passivity areas. Copper at the anticipated repository potentials and pH corrodes at 100 deg C at [Cu(aq)]{sub tot} = 10{sup -4} molal and at 80-100 deg C at [Cu(aq)]{sub tot} = 10{sup -6} molal. Copper at the anticipated repository potentials and pH can corrode at 80 deg C at [Cu(aq)]{sub tot} = 10{sup -4} molal and at 50 deg C at [Cu(aq)]{sub tot} = 10{sup -6} molal. The bentonite clay and copper canisters in the deep repository can be considered as a 'closed' system from macroscopic point of view. The clay barrier limits both inward diffusion of oxygen and aggressive anions as well as outward diffusion of corrosion products from the canisters. Both diffusion phenomena will drive the corrosion potential into the immunity area of the Pourbaix diagram for copper. The corrosion will thereby stop by an automatic

  5. Lead sulphate leaching by sodium chloride solution

    OpenAIRE

    Conić Vesna T.; Pešovski Branka D.; Cvetkovski Vladimir B.; Stanojević-Šimšić Zdenka S.; Dragulović Suzana S.; Simonović Danijela B.; Dimitrijević Silvana B.

    2013-01-01

    Bioleaching treatment of complex multi-metallic Cu-Zn-Pb-Ag-Au mineral concentrates leds to the formation, besides easily soluble zinc and cooper sulphates, of hardly soluble lead (II) sulfate (PbSO4) sludge. To determine the leaching parameters of PbSO4 with NaCl in the bioleaching residue, lead sulphate solution was synthetically prepared. The effect of process parameters, namely NaCl concentration, solid:liquid phase ratio, processing time, temperature and Cl ions was examined. It wa...

  6. Platinum uptake from chloride solutions using biosorbents

    Directory of Open Access Journals (Sweden)

    Mehmet Hakan Morcali

    2013-04-01

    Full Text Available Present work investigates platinum uptake from synthetically prepared, dilute platinum-bearing solutions using biomass residues, i.e. pistachio nut shell and rice husk, which are abundant in Turkey, and provides a comparison between these two biosorbents. Effects of the different uptake parameters, sorbent dosage, contact time, temperature and pH of solution on platinum uptake (% were studied in detail on a batch sorption. Before the pistachio nut shell was activated, platinum uptake (% was poor compared to the rice husk. However, after the pistachio nut shell was activated at 1000 °C under an argon atmosphere, the platinum uptake (% increased two-fold. The pistachio nut shell (original and activated and rice husk were shown to be better than commercially available activated carbon in terms of adsorption capacity. These two sorbents have also been characterized by FTIR and SEM. Adsorption equilibrium data best complied with the Langmuir isotherm model. Maximum adsorption capacities, Qmax, at 25 °C were found to be 38.31 and 42.02 mg.g- 1for the activated pistachio nut shell and rice husk, respectively. Thermodynamic calculations using the measured ∆H°, ∆S° and ∆G° values indicate that the uptake process was spontaneous and endothermic. The experimental data were shown to be fit the pseudo-second-order kinetic model.

  7. Lead sulphate leaching by sodium chloride solution

    Directory of Open Access Journals (Sweden)

    Conić Vesna T.

    2013-01-01

    Full Text Available Bioleaching treatment of complex multi-metallic Cu-Zn-Pb-Ag-Au mineral concentrates leds to the formation, besides easily soluble zinc and cooper sulphates, of hardly soluble lead (II sulfate (PbSO4 sludge. To determine the leaching parameters of PbSO4 with NaCl in the bioleaching residue, lead sulphate solution was synthetically prepared. The effect of process parameters, namely NaCl concentration, solid:liquid phase ratio, processing time, temperature and Cl ions was examined. It was found that 100% Pb by leaching can be achieved with NaCl concentration of 250 g/dm3, time 20 min, temperature 353 K and solid:liquid phase ratio =1:20.

  8. Intergranular Corrosion of 2024 Alloy in Chloride Solutions

    OpenAIRE

    Augustin, Christel; Andrieu, Eric; Blanc, Christine; Mankowski, Georges; Delfosse, Jérôme

    2007-01-01

    Experiments were performed to determine the propagation kinetics of intergranular corrosion on 2024 aluminum alloy immersed in 1 and 3 M chloride solutions. Tests consisting of immersion in a corrosive solution followed by optical observations on sectioned samples were carried out. This method was found to be time consuming and led to a lack of reproducibility due to the random nature of the corrosion attacks. Another method proved to be more efficient; it consisted of measuring the load to f...

  9. Crevice Corrosion of 321 Stainless Steel in Sodium Chloride Solutions

    International Nuclear Information System (INIS)

    Electrochemical techniques have been applied to study the crevice corrosion behaviour of stabilized 321 stainless steel in both 0.5, 1 and 2 M sodium chloride solutions at 25 and 80 degree . This type of stainless steel enjoys a good corrosion resistance especially in the heat affected zone (Haz) of welds. In this investigation the crevice corrosion of 321 stainless steel was studied in both bulk solution environments as well as in chloride solutions simulating those formed inside crevices. A metal-to-nonmetal crevice assembly, in which disc type specimens were faced to a PTFE crevice former, is used for bulk solution tests. Crevice-free specimens of solutions formed inside crevices (known as the critical crevice solutions, CCS). Cyclic potentiodynamic technique was used in evaluating the electrochemical corrosion performance of the alloy in bulk (0.5 and 1 M Nacl) environment. This revealed that both chloride ion concentration and temperature have a marked effect on the electrochemical parameters generally used for the evaluation of the crevice corrosion susceptibility. This included the corrosion potential. E corr. The passivity breakdown potential, Eb, and the protection potential, E p

  10. Synthesis of brookite-typed titania from titanium chloride solution

    Institute of Scientific and Technical Information of China (English)

    Satoshi OKANO; Saeki YAMAMURO; Toshiro TANAKA

    2009-01-01

    The brookite-phase TiO2 was prepared by a hydrothermal synthesis of titanium chloride solution. The thermolysis time and the pH value of the solution were controlled during the synthesis. X-ray diffraction experiments showed that TiO2 powders partially containing the brookite-phase were successfully ob-tained. A great amount of OH in the reaction solution was found to be important to obtain the brookite phase because the intermediate complex leading to the brookite phase consumes more OH- than other phases like the rutile.

  11. Synthesis of brookite-typed titania from titanium chloride solution

    Institute of Scientific and Technical Information of China (English)

    Satoshi; OKANO; Saeki; YAMAMURO; Toshiro; TANAKA

    2009-01-01

    The brookite-phase TiO2 was prepared by a hydrothermal synthesis of titanium chloride solution. The thermolysis time and the pH value of the solution were controlled during the synthesis. X-ray diffraction experiments showed that TiO2 powders partially containing the brookite-phase were successfully obtained. A great amount of OH-in the reaction solution was found to be important to obtain the brookite phase because the intermediate complex leading to the brookite phase consumes more OH- than other phases like the rutile.

  12. INTERACTION OF POLYVINYLPYRROLIDONE WITH METAL CHLORIDE AQUEOUS SOLUTIONS

    Institute of Scientific and Technical Information of China (English)

    Mohammad Saleem Khan; Khaista Gul; Najeeb Ur Rehman

    2004-01-01

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

  13. Sodium chloride methanol solution spin-coating process for bulk-heterojunction polymer solar cells

    Science.gov (United States)

    Liu, Tong-Fang; Hu, Yu-Feng; Deng, Zhen-Bo; Li, Xiong; Zhu, Li-Jie; Wang, Yue; Lv, Long-Feng; Wang, Tie-Ning; Lou, Zhi-Dong; Hou, Yan-Bing; Teng, Feng

    2016-08-01

    The sodium chloride methanol solution process is conducted on the conventional poly(3-hexylthiophene) (P3HT)/[6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) polymer bulk heterojunction solar cells. The device exhibits a power conversion efficiency of up to 3.36%, 18% higher than that of the device without the solution process. The measurements of the active layer by x-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and ultraviolet photoelectron spectroscopy (UPS) indicate a slight phase separation in the vertical direction and a sodium chloride distributed island-like interface between the active layer and the cathode. The capacitance–voltage (C–V) and impedance spectroscopy measurements prove that the sodium chloride methanol process can reduce the electron injection barrier and improve the interfacial contact of polymer solar cells. Therefore, this one-step solution process not only optimizes the phase separation in the active layers but also forms a cathode buffer layer, which can enhance the generation, transport, and collection of photogenerated charge carriers in the device simultaneously. This work indicates that the inexpensive and non-toxic sodium chloride methanol solution process is an efficient one-step method for the low cost manufacturing of polymer solar cells. Project supported by the Fundamental Research Funds for the Central Universities, China (Grant No. 2014JBZ009) and the National Natural Science Foundation of China (Grant Nos. 61274063, 61377028, 61475014, and 61475017).

  14. Sodium chloride methanol solution spin-coating process for bulk-heterojunction polymer solar cells

    Science.gov (United States)

    Liu, Tong-Fang; Hu, Yu-Feng; Deng, Zhen-Bo; Li, Xiong; Zhu, Li-Jie; Wang, Yue; Lv, Long-Feng; Wang, Tie-Ning; Lou, Zhi-Dong; Hou, Yan-Bing; Teng, Feng

    2016-08-01

    The sodium chloride methanol solution process is conducted on the conventional poly(3-hexylthiophene) (P3HT)/[6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) polymer bulk heterojunction solar cells. The device exhibits a power conversion efficiency of up to 3.36%, 18% higher than that of the device without the solution process. The measurements of the active layer by x-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and ultraviolet photoelectron spectroscopy (UPS) indicate a slight phase separation in the vertical direction and a sodium chloride distributed island-like interface between the active layer and the cathode. The capacitance-voltage (C-V) and impedance spectroscopy measurements prove that the sodium chloride methanol process can reduce the electron injection barrier and improve the interfacial contact of polymer solar cells. Therefore, this one-step solution process not only optimizes the phase separation in the active layers but also forms a cathode buffer layer, which can enhance the generation, transport, and collection of photogenerated charge carriers in the device simultaneously. This work indicates that the inexpensive and non-toxic sodium chloride methanol solution process is an efficient one-step method for the low cost manufacturing of polymer solar cells. Project supported by the Fundamental Research Funds for the Central Universities, China (Grant No. 2014JBZ009) and the National Natural Science Foundation of China (Grant Nos. 61274063, 61377028, 61475014, and 61475017).

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

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

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

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

    OpenAIRE

    Fujio, Katsuhiko; Hayashi, Koji; Suzuki, Maki

    2014-01-01

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

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

    OpenAIRE

    Fujio, Katsuhiko; TAKEUCHI, Kumiko; Suzuki, Maki

    2012-01-01

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

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

    International Nuclear Information System (INIS)

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

  19. Effect of Organic Inhibitors on Chloride Corrosion of Steel Rebars in Alkaline Pore Solution

    Directory of Open Access Journals (Sweden)

    Marina Cabrini

    2015-01-01

    Full Text Available The inhibition properties of aspartic and lactic acid salts are compared with nitrite ions with regard to their effect on critical chloride concentration. The tests were carried out on carbon steel specimens in simulated pore solutions with initial pH in the range of 12.6 to 13.8. The critical chloride concentrations were estimated through multiple specimen potentiostatic tests at potentials in the usual range for passive rebar in noncarbonated concrete structures. During tests, chloride ions were progressively added until all specimens showed localized attack, obtaining cumulative distribution curves reporting the fraction of corroded specimens as a function of chloride concentration. The presence of the organic inhibitors on the passivity film was detected by IR spectra. The results confirm that 0.1 M aspartate exhibits an inhibiting effect comparable with nitrite ions of the same concentration. Calcium lactate does not increase critical chloride concentration; however it appears to promote the formation of a massive scale, reducing the corrosion propagation.

  20. Effects of Organic Corrosion Inhibitor and Chloride Ion Concentration on Steel Depassivation and Repassivation in Solution

    Institute of Scientific and Technical Information of China (English)

    WANG Zixiao; YU Lei; LIU Zhiyong; SONG Ning

    2015-01-01

    Effect of an organic corrosion inhibitor (OCI) named PCI-2014 added in chloride solution on the critical chlo-ride concentration of mild steel depassivation and the critical OCI concentrations for repairing the steel in different chlo-ride solution were investigated. The results show that the critical chloride concentration increases exponentially with raises of PCI-2014 concentration in the solution. Within a certain chloride ion concentration range, the critical PCI-2014 concentration for repairing the corroded steel is also increases exponentially with enhancement of chloride content in the solution. Atomic force microscopy images display the molecular particles of inhibitor are adsorbed on the steel surface and formed a protective layer. Analysis of X-ray photoelectron spectroscopy shows the chloride ions at the surface of steel are displaced by atoms or molecules of the inhibitor in chloride condition.

  1. Copper electrodeposition from cuprous chloride solutions containing lead, zinc or iron ions

    Institute of Scientific and Technical Information of China (English)

    M. Tchoumou; M. Roynette Ehics

    2005-01-01

    Cuprous chloride hydrochloric acid solutions were electrolysed in a two compartments cell without agitation for copper extraction. It is found that the current density affects the colour and the size of copper deposits. During electrodeposition of copper from cuprous solution in the presence of various concentrations of lead, zinc or iron ions at different current densities, it is observed that lead is codeposited with copper by increasing current density.In all experiments, the current efficiency for the copper deposition reaction fluctuates between 88.50% and 95.50%.

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

    Directory of Open Access Journals (Sweden)

    C. Anastasio

    2006-02-01

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

  3. Preparation of Pure Copper Powder from Acidic Copper Chloride Waste Etchant

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The method for the recycling of copper from copper chloride solution was developed. This process consists of extraction of copper, purification and particle size reduction. In the first step, reductive metal scraps were added to acidic copper chloride waste enchants produced in the PCB industry to obtain copper powder.Composition analysis showed that this powder contained impurities such as Fe, Ni, and water. So, drying and purification were carried out by using microwave and a centrifugal separator. Thereby the copper powder had a purity of higher than 99% and spherical form in morphology. The copper powder size was decreased by ball milling.

  4. Corrosion of LY12 aluminum alloy in sodium chloride solution

    Institute of Scientific and Technical Information of China (English)

    程英亮; 张昭; 曹发和; 李劲风; 张鉴清; 王建明; 曹楚南

    2003-01-01

    The corrosion behavior of LY12 alloy in sodium chloride solution and its electrochemical noise were reported. The development of the micro-pits on the alloy surface was monitored by scanning electron microscopy, scanning tunneling microscopy, and electrochemical noise method. All the measurements show that the corrosion of LY12 alloy can be divided into two stages: a very reactive initial stage and a relative constant stable stage. The initial stage is corresponded to the adsorption of Cl ions and its reaction with the oxide film and the dissolution of Mg containing particles. The stable stage is corresponded to the development of the micro-pits by the galvanic attack formed by Al-Fe-Cu-Mn containing particles and the matrix. The initial stage lasts about 2-3 h while the stable stage dominates the whole corrosion process.

  5. Corrosion of alloy 22 in phosphate and chloride containing solutions

    International Nuclear Information System (INIS)

    Alloy C-22 is a Ni-based alloy (22% Cr, 13% Mo, 3% W y 3% Fe in weight per cent) that exhibits an excellent uniform and localized corrosion resistance due to its protective passive film. It was designed to resist the most aggressive environments for industrial applications. Alloy 22 is one of the candidates to be considered for the outer shell of the canister that would contain high level radioactive nuclear wastes. The effect of phosphate ion in chloride containing solutions at 90 C degrees was studied under aggressive conditions were this material might be susceptible to crevice corrosion. The electrolyte solution, which consisted of 1M NaCl and different phosphate concentrations (between 10-3M and 1M), was deoxygenated by bubbling with nitrogen. Electrochemical tests, electron microscope observations (SEM) and energy dispersive spectrometer analysis (EDS) were conducted. Crevice corrosion was not detected and the comparison of the potentiodynamic polarization tests showed an increase of the passivity range in phosphate containing solutions. The passive current value was 1 μA/cm2 approximately in all the tests that were performed in this work. The differences in composition of the anodic film formed on the samples suggest that phosphate is responsible for the increase of the passivity range by incorporation to the passive film. (author)

  6. The Effect of Silver Chloride Formation on the Kinetics of Silver Dissolution in Chloride Solution

    Science.gov (United States)

    Ha, Hung; Payer, Joe

    2011-01-01

    The precipitation and growth of AgCl on silver in physiological NaCl solution were investigated. AgCl was found to form at bottom of scratches on the surface which may be the less effective sites for diffusion or the favorable sites for heterogeneous nucleation. Patches of silver chloride expanded laterally on the substrate until a continuous film formed. The ionic transport path through this newly formed continuous film was via spaces between AgCl patches. As the film grew, the spaces between AgCl patches closed and ion transport was primarily via micro-channels running through AgCl patches. The decrease of AgCl layer conductivity during film growth were attributed to the clogging of micro-channels or decrease in charge carrier concentration inside the micro-channels. Under thin AgCl layer, i.e. on the order of a micrometer, the dissolution of silver substrate was under mixed activation-Ohmic control. Under thick AgCl layer, i.e. on the order of tens of micrometers, the dissolution of silver substrate was mediated by the Ohmic resistance of AgCl layer. PMID:21516171

  7. The Effect of Silver Chloride Formation on the Kinetics of Silver Dissolution in Chloride Solution.

    Science.gov (United States)

    Ha, Hung; Payer, Joe

    2011-02-28

    The precipitation and growth of AgCl on silver in physiological NaCl solution were investigated. AgCl was found to form at bottom of scratches on the surface which may be the less effective sites for diffusion or the favorable sites for heterogeneous nucleation. Patches of silver chloride expanded laterally on the substrate until a continuous film formed. The ionic transport path through this newly formed continuous film was via spaces between AgCl patches. As the film grew, the spaces between AgCl patches closed and ion transport was primarily via micro-channels running through AgCl patches. The decrease of AgCl layer conductivity during film growth were attributed to the clogging of micro-channels or decrease in charge carrier concentration inside the micro-channels. Under thin AgCl layer, i.e. on the order of a micrometer, the dissolution of silver substrate was under mixed activation-Ohmic control. Under thick AgCl layer, i.e. on the order of tens of micrometers, the dissolution of silver substrate was mediated by the Ohmic resistance of AgCl layer.

  8. Synthesis and characterization of zinc chloride containing poly(acrylic acid) hydrogel by gamma irradiation

    International Nuclear Information System (INIS)

    In this study, the characterization of zinc chloride incorporated into a poly(acrylic acid) (PAAc) hydrogel prepared by gamma-ray irradiation was investigated. Zinc chloride powder with different concentrations was dissolved in the PAAc solution, and it was crosslinked with gamma-ray irradiation. The effects of various parameters such as zinc ion concentration and irradiation doses on characteristics of the hydrogel formed were investigated in detail for obtaining an antibacterial wound dressing. In addition, the gel content, pH-sensitive (pH 4 or 7) swelling ratio, and UV–vis absorption spectra of the zinc particles in the hydrogels were characterized. Moreover, antibacterial properties of these new materials against Staphylococcus aureus and Escherichia coli strains were observed on solid growth media. The antibacterial tests indicated that the zinc chloride containing PAAc hydrogels have good antibacterial activity. - Highlights: • The characterization of zinc chloride containing PAA hydrogel was investigated. • The gel content increased with an increase in absorbed dose up to 75 kGy. • Finally, the zinc chloride based hydrogels have an antibacterial activity

  9. Stress Corrosion Cracking of an Austenitic Stainless Steel in Nitrite-Containing Chloride Solutions

    Directory of Open Access Journals (Sweden)

    R. K. Singh Raman

    2014-12-01

    Full Text Available This article describes the susceptibility of 316L stainless steel to stress corrosion cracking (SCC in a nitrite-containing chloride solution. Slow strain rate testing (SSRT in 30 wt. % MgCl2 solution established SCC susceptibility, as evidenced by post-SSRT fractography. Addition of nitrite to the chloride solution, which is reported to have inhibitive influence on corrosion of stainless steels, was found to increase SCC susceptibility. The susceptibility was also found to increase with nitrite concentration. This behaviour is explained on the basis of the passivation and pitting characteristics of 316L steel in chloride solution.

  10. Chloride content and pH value in the pore solution of concrete under carbonation

    Institute of Scientific and Technical Information of China (English)

    Xiao-mei WAN; Folker H.WITTMANN; Tie-jun ZHAO; Hong FAN

    2013-01-01

    Chloride content and the pH value of the pore solution in the neighborhood of steel reinforcement are decisive parameters for initiation and rate of corrosion.The pore solution of cement mortar and hardened cement paste has been expressed from the pore space by high pressure in the investigation.The influence of the water-cement ratio,age,and addition of chloride to the fresh mix on chloride content in the pore solution has been determined by ion chromatography.At the same time the pH value of the pore solution has been determined.The dissolved chloride content decreases with increase in the water-cement ratio.The amount of bound chloride increases with time,but it decreases with decreasing content of dissolved chloride in the pore solution.A significant influence of carbonation on the dissolved chloride content of the pore solution has been observed.With complete carbonation,the dissolved chloride content in cement mortar and hardened cement paste increases by a factor between 2 and 12.The bound chloride decreases by 27%-54%.As expected,the pH value decreases from around 13.2 to as low as 8.0 due to carbonation.It can be concluded that carbonation not only lowers the pH value but liberates bound chloride.This is one obvious reason why the combined action of chloride penetration and carbonation accelerates steel corrosion and shortens the service life of reinforced concrete structures.

  11. Copper(I) mediated cross-coupling of amino acid derived organozinc reagents with acid chlorides

    DEFF Research Database (Denmark)

    Hjelmgaard, Thomas; Tanner, David Ackland

    2006-01-01

    This paper describes the development of a straightforward experimental protocol for copper-mediated cross-coupling of amino acid derived beta-amido-alkylzinc iodides 1 and 3 with a range of acid chlorides. The present method uses CuCN center dot 2LiCl as the copper source and for organozinc reagent...

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

    International Nuclear Information System (INIS)

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

  13. 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.

  14. Mechanical properties of cement mortar in sodium sulfate and sodium chloride solutions

    Institute of Scientific and Technical Information of China (English)

    熊良宵; 虞利军

    2015-01-01

    To investigate the mechanical properties of cement mortar in sodium sulfate and sodium chloride solutions, uniaxial compression test and ultrasonic test were performed. Test results show that the relative dynamic elastic modulus, the mass variation, and the compressive strength of cement mortar increase first, and then decrease with increasing erosion time in sodium sulfate and sodium chloride solutions. The relative dynamic elastic moduli and the compressive strengths of cement mortars with water/cement ratios of 0.55 and 0.65 in sodium sulfate solution are lower than those in sodium chloride solution with the same concentration at the 420th day of immersion. The compressive strength of cement mortar with water/cement ratio of 0.65 is more sensitive to strain rate than that with water/cement ratio of 0.55. In addition, the strain-rate sensitivity of compressive strength of cement mortar will increase under attacks of sodium sulfate or sodium chloride solution.

  15. Effect of gamma radiation on glucose and sodium chloride solutions for injection

    International Nuclear Information System (INIS)

    Irradiation of 40% glucose solution with 0.5-4.0 Mrads di not affect the detoxicating properties of glucose or its ability to raise blood sugar levels. Such doses had no effect on the toxicological properties of 40% glucose solution and on 0.9% sodium chloride solution. The biological and physicochemical properties of 40% solution and 0.9% sodium chloride solutions irradiated with sterilizing doses showed no significant alterations during storage for one and three years, respectively. It is concluded that the solutions studied may be sterilized by radiation. (auth.)

  16. Effect of pH and chloride on the micro-mechanism of pitting corrosion for high strength pipeline steel in aerated NaCl solutions

    International Nuclear Information System (INIS)

    Highlights: • Pitting behavior of X80 steel in aerated NaCl solutions is studied systematically. • Unique large pit morphology is observed in neutral/acidic NaCl solutions. • In low pH solutions, pit will propagate in the horizontal direction, leading to the shallow shape of pitting morphology; in high pH solutions, the pit sizes are much smaller. • Film growth, which is dependent on the pH and chloride concentration, has great influence on the cathodic reaction by affecting oxygen diffusion process. - Abstract: The pitting corrosion mechanism of high strength pipeline steel in aerated NaCl solutions with different pH and chloride content was investigated, using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and scanning electron microscope (SEM). The pitting behavior in alkaline solutions was found to be significantly different from that in neutral and acidic solutions. Electrochemical results and SEM images indicate that the product film formed on the steel surface results in different corrosion behavior in an alkaline solution. SEM images show that pH and chloride concentration in the bulk solution have a great influence on the pitting morphology. Unique large pit morphology due to corrosion in neutral/acidic solutions with 0.05 mol/L NaCl was observed. The relationship between solution pH and the effect of chloride concentration is also discussed

  17. Reactivity Ratios of Diethyldiallylammonium Chloride with Acrylamide or Acrylic Acid

    Institute of Scientific and Technical Information of China (English)

    Li Hua LIU; Zhi Qiang LIU; Zhu Qing GONG

    2006-01-01

    The compositions of copolymers of diethyldiallylammonium chloride (DEDAAC) with acrylamide (AM), acrylic acid (AA) or sodium acrylic acid (NaAA) at low conversion were determined by elemental analysis, and the reactivity ratios of monomers in copolymerization were obtained by Kelen-Tudos method. The results showed that the reactivity ratios rDE and rAM are 0.31 and 5.27 for DEDAAC with AM, rDE and rAA are 0.28 and 5.15 for DEDAAC with AA, and rDE and rNaAA are 0.40 and 3.97 for DEDAAC with NaAA, respectively. The copolymerizations for DEDAAC with AM, AA or NaAA are non-ideal copolymerization and the products are random copolymers.

  18. Potentiometric titration of uranium reduced by chromic salts in chloridic solutions

    International Nuclear Information System (INIS)

    The utilization of chromic salts for reducing the uranium (VI) from chloridic solutions, for potentiometric dosage is described. This method is used in the range of 0,002 to 1,0 M of uranium. (C.G.C.)

  19. Crevice corrosion of alloy 22 in fluoride and chloride containing solutions

    International Nuclear Information System (INIS)

    Alloy 22 (N06022) is highly resistant to localized corrosion. Alloy 22 may be susceptible to crevice corrosion in pure chloride (Cl-) solutions under aggressive environmental conditions. The effect of the fluoride (F-) on the susceptibility to crevice corrosion induced by chloride ions is still not well established. The objective of the present work was to explore the crevice corrosion resistance of this alloy to different mixtures of fluorides and chlorides. Cyclic potentiodynamic polarization (CPP) tests were conducted in deaerated aqueous solutions of pure halide ions and also in different mixtures of chloride and fluoride at 90 C degrees and pH 6. The range of chloride concentration [Cl-] was 0.001 M ≤ [Cl-] ≤ 1 M and the range of molar fluoride to chloride ratio [F-]/[Cl-] was 0.1≤ [F-]/[Cl-] ≤ 10. Results showed that Alloy 22 was susceptible to crevice corrosion in all the pure chloride solutions but not in the pure fluoride solutions. A molar ratio [F-]/[Cl-] ranging from 5 to 10 was required for the inhibition of crevice corrosion to be complete in the halide mixtures. A moderate or nil inhibitive effect was observed for molar ratios [F-]/[Cl-] < 5. (author)

  20. Cyclic stress effect on stress corrosion cracking of duplex stainless steel in chloride and caustic solutions

    Science.gov (United States)

    Yang, Di

    Duplex stainless steel (DSS) is a dual-phase material with approximately equal volume amount of austenite and ferrite. It has both great mechanical properties (good ductility and high tensile/fatigue strength) and excellent corrosion resistance due to the mixture of the two phases. Cyclic loadings with high stress level and low frequency are experienced by many structures. However, the existing study on corrosion fatigue (CF) study of various metallic materials has mainly concentrated on relatively high frequency range. No systematic study has been done to understand the ultra-low frequency (˜10-5 Hz) cyclic loading effect on stress corrosion cracking (SCC) of DSSs. In this study, the ultra-low frequency cyclic loading effect on SCC of DSS 2205 was studied in acidified sodium chloride and caustic white liquor (WL) solutions. The research work focused on the environmental effect on SCC of DSS 2205, the cyclic stress effect on strain accumulation behavior of DSS 2205, and the combined environmental and cyclic stress effect on the stress corrosion crack initiation of DSS 2205 in the above environments. Potentiodynamic polarization tests were performed to investigate the electrochemical behavior of DSS 2205 in acidic NaCl solution. Series of slow strain rate tests (SSRTs) at different applied potential values were conducted to reveal the optimum applied potential value for SCC to happen. Room temperature static and cyclic creep tests were performed in air to illustrate the strain accumulation effect of cyclic stresses. Test results showed that cyclic loading could enhance strain accumulation in DSS 2205 compared to static loading. Moreover, the strain accumulation behavior of DSS 2205 was found to be controlled by the two phases of DSS 2205 with different crystal structures. The B.C.C. ferrite phase enhanced strain accumulation due to extensive cross-slips of the dislocations, whereas the F.C.C. austenite phase resisted strain accumulation due to cyclic strain

  1. 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.

  2. Enthalpic Pair Interaction of Rubidium Chloride with α-Amino Acid in Water at 298.15K

    Institute of Scientific and Technical Information of China (English)

    胡满成; 杨茜; 蒋育澄; 夏树屏

    2005-01-01

    The mixing enthalpies of aqueous heavy rare alkali metal chloride RbC1 solutions with aqueous α-amino acid (Loglycine, L-alanine and α-aminobutyric acid) solutions, as well as the dilution enthalpies of RbC1 and α-amino acid solutions in pure water had been measured at 298.15K. The transfer enthalpies of RbCI from pure water to aqueous α-amino acid solutions could be obtained from these data. The enthalpic pair interaction parameters of RbC1 with α-amino acid in water have been evaluated according to the McMillan-Mayer theory and discussed in terms of the electrostatic interaction, structure interaction and Savage-wood group additivity mode.

  3. Analysis of PWR auxiliary coolant: determination of chloride in borax/nitrite solution by known addition - known dilution potentiometry

    International Nuclear Information System (INIS)

    Chloride concentrations of 75-250 μg 1-1 have been determined in simulated PWR auxiliary coolant containing 1000 mg l-1 each of sodium tetraborate and sodium nitrite. The effects of the two main components of the coolant solution on a variety of chloride-selective electrodes have been studied. Sodium tetraborate posed no problem except through its effect on the pH, which is easily adjusted. Such high concentrations of nitrite, however, caused significant deviations in e.m.f. for all the electrodes and marked tarnishing of the electroactive membrane after only one or two measurements. Sulphamic acid was selected as the best means of removing nitrite and silver chloride electrodes were preferred over mercury(I) chloride electrodes because of their greater robustness in the conditions. At these chloride concentrations, the electrodes are operating in their non-Nernstian response regions and direct potentiometry has poor precision, even if standards could be successfully matched to samples containing such high concentrations of background material. Known addition - known dilution potentiometry was adopted, with internal calibration for both slope factor and standard potential. (author)

  4. Corrosion Inhibition of Carbon Steel in Chloride and Sulfate Solutions

    Directory of Open Access Journals (Sweden)

    Amr Ahmed Elsayed

    2016-02-01

    Full Text Available Corrosion is a major problem in industry and in infrastructure; a huge sum of expenditure every year is spent on preventing, retarding, and repairing its damages. This work studies the engineering of an inhibitor for carbon steel metal used in the cooling systems containing high concentration of chloride and sulfate ions. For this purpose, the synergy between the dichromate, molybdate and nitrite inhibitors is examined and optimized to the best results. Moreover, care was taken that the proposed inhibitor is compliant with the environmental laws and regulations.

  5. Fabrication and Performance of All-Solid-State Chloride Sensors in Synthetic Concrete Pore Solutions

    OpenAIRE

    Gao, Xiaojian; Zhang, Jian; Yang, Yingzi; Deng, Hongwei

    2010-01-01

    One type of all-solid-state chloride sensor was fabricated using a MnO2 electrode and a Ag/AgCl electrode. The potentiometric response of the sensor to chloride in synthetic concrete pore solutions was systematically studied, and the polarization performance was also evaluated. The results show a good linear relationship between the potential reading of the sensor and the logarithm of chloride activity (concentration ranges from 0.05 to 5.0 M), and the potential value remains stable with incr...

  6. Unilateral segmental hyperhidrosis. Response to 20% aluminum chloride solution and plastic wrap.

    Science.gov (United States)

    Dworin, A; Sober, A J

    1978-05-01

    A young woman had unilateral dermatomal hyperhidrosis documented by a starch-iodine technique. Evaluation failed to reveal any associated causative conditions. She was treated with 20% aluminum chloride hexahydrate solution in absolute alcohol (Drysol) with a favorable response. With recurrent use, however, she developed miliaria following exertion. Aluminum chloride hexahydrate was shown to be an effective agent to treat this unusual condition, but miliaria with exertion secondary to its use may be a limiting factor. PMID:646401

  7. Nickel electrodeposition from leaching solution containing ammonia and chloride

    Institute of Scientific and Technical Information of China (English)

    郑国渠; 郑利峰; 曹华珍; 高志峰; 倪似愚; 张九渊

    2003-01-01

    The effects of temperature, nickel concentration and current density on the current efficiency and the e-lectrolyzer voltage were investigated in the process of electrowinning nickel. The results show that the current effi-ciency is above 90 % under the various experimental conditions, and the electrolyzer voltage is less than that of tradi-tional electrolyzer system. Therefore, the optimized parameters, i.e. temperature of 50 C, current density of 400A/m2 , are determined. It is also elucidated that anodic product is high valent nickel compound in the process of elec-trodeposition in terms of X-ray diffraction and chemical analysis. The amount of solid product formed on the elec-trode surface decreases with an increase in ammonium chloride concentration by cyclic voltammetry analysis. It is al-so indicated that the anodic gas species are mainly composed of nitrogen by vapor phase chromatograph.

  8. Redox flow batteries based on supporting solutions containing chloride

    Energy Technology Data Exchange (ETDEWEB)

    Li, Liyu; Kim, Soowhan; Yang, Zhenguo; Wang, Wei; Zhang, Jianlu; Chen, Baowei; Nie, Zimin; Xia, Guanguang

    2014-01-14

    Redox flow battery systems having a supporting solution that contains Cl.sup.- ions can exhibit improved performance and characteristics. Furthermore, a supporting solution having mixed SO.sub.4.sup.2- and Cl.sup.- ions can provide increased energy density and improved stability and solubility of one or more of the ionic species in the catholyte and/or anolyte. According to one example, a vanadium-based redox flow battery system is characterized by an anolyte having V.sup.2+ and V.sup.3+ in a supporting solution and a catholyte having V.sup.4+ and V.sup.5+ in a supporting solution. The supporting solution can contain Cl.sup.- ions or a mixture of SO.sub.4.sup.2- and Cl.sup.- ions.

  9. Redox flow batteries based on supporting solutions containing chloride

    Energy Technology Data Exchange (ETDEWEB)

    Li, Liyu; Kim, Soowhan; Yang, Zhenguo; Wang, Wei; Nie, Zimin; Chen, Baowei; Zhang, Jianlu; Xia, Guanguang

    2015-07-07

    Redox flow battery systems having a supporting solution that contains Cl.sup.- ions can exhibit improved performance and characteristics. Furthermore, a supporting solution having mixed SO.sub.4.sup.2- and Cl.sup.- ions can provide increased energy density and improved stability and solubility of one or more of the ionic species in the catholyte and/or anolyte. According to one example, a vanadium-based redox flow battery system is characterized by an anolyte having V.sup.2+ and V.sup.3+ in a supporting solution and a catholyte having V.sup.4+ and V.sup.5+ in a supporting solution. The supporting solution can contain Cl.sup.- ions or a mixture of SO.sub.4.sup.2- and Cl.sup.- ions.

  10. Redox flow batteries based on supporting solutions containing chloride

    Energy Technology Data Exchange (ETDEWEB)

    Li, Liyu; Kim, Soowhan; Yang, Zhenguo; Wang, Wei; Nie, Zimin; Chen, Baowei; Zhang, Jianlu; Xia, Guanguang

    2015-09-01

    Redox flow battery systems having a supporting solution that contains Cl.sup.- ions can exhibit improved performance and characteristics. Furthermore, a supporting solution having mixed SO.sub.4.sup.2- and Cl.sup.- ions can provide increased energy density and improved stability and solubility of one or more of the ionic species in the catholyte and/or anolyte. According to one example, a vanadium-based redox flow battery system is characterized by an anolyte having V.sup.2+ and V.sup.3+ in a supporting solution and a catholyte having V.sup.4+ and V.sup.5+ in a supporting solution. The supporting solution can contain Cl.sup.- ions or a mixture of SO.sub.4.sup.2- and Cl.sup.- ions.

  11. Recovery of nickel, cobalt, copper and zinc in sulphate and chloride solutions using synergistic solvent extraction

    Institute of Scientific and Technical Information of China (English)

    Chu Yong Cheng; Keith R. Barnard; Wensheng Zhang; Zhaowu Zhu; Yoko Pranolo

    2016-01-01

    A number of synergistic solvent extraction (SSX) systems have been developed to recover nickel, cobalt, zinc and copper from sulphuric and chloride leach solutions by the solvent extraction team of CSIRO, Australia. These in-clude (1) Versatic 10/CLX50 system for the separation of Ni from Ca in sulphate solutions, (2) Versatic 10/4PC system for the separation of Ni and Co from Mn/Mg/Ca in sulphate solutions, (3) Cyanex 471X/HRJ-4277 system for the separation of Zn from Cd in sulphate solutions, (4) Versatic 10/LIX63 system for the separation of Co from Mn/Mg/Ca in sulphate solutions, (5) Versatic 10/LIX63/TBP system for separation of Ni and Co from Mn/Mg/Ca in sulphate solutions, (6) Versatic 10/LIX63 system for the separation of cobalt from nickel in sulphate solutions by difference in kinetics, (7) Cyanex 272/LIX84 system for the separation of Cu/Fe/Zn from Ni/Co in sulphate solutions, (8) Versatic 10/LIX63/TBP system to recover Cu/Ni from strong chloride solutions, and (9) Versatic 10/LIX63 system to separate Cu from Fe in strong chloride solutions. The synergistic effect on metal separation and efficiency is presented and possible industrial applications are demonstrated. The chemical stability of selected SSX systems is also reported.

  12. Fabrication and Performance of All-Solid-State Chloride Sensors in Synthetic Concrete Pore Solutions

    Directory of Open Access Journals (Sweden)

    Hongwei Deng

    2010-11-01

    Full Text Available One type of all-solid-state chloride sensor was fabricated using a MnO2 electrode and a Ag/AgCl electrode. The potentiometric response of the sensor to chloride in synthetic concrete pore solutions was systematically studied, and the polarization performance was also evaluated. The results show a good linear relationship between the potential reading of the sensor and the logarithm of chloride activity (concentration ranges from 0.05 to 5.0 M, and the potential value remains stable with increasing immersion time. The existence of K+, Ca2+, Na+ and SO42− ions have little influence on the potentiometric response of the sensor to chloride, but the pH has a significant influence on the potential value of the sensor at low chloride concentration. The potential reading of the sensor increases linearly with the solution temperature over the range from 5 to 45 °C. Meanwhile, an excellent polarization behavior is proven by galvanostatic and potentiodynamic tests. All of the results reveal that the developed sensor has a great potential for monitoring chloride ions in concrete environments.

  13. Fabrication and performance of all-solid-state chloride sensors in synthetic concrete pore solutions.

    Science.gov (United States)

    Gao, Xiaojian; Zhang, Jian; Yang, Yingzi; Deng, Hongwei

    2010-01-01

    One type of all-solid-state chloride sensor was fabricated using a MnO(2) electrode and a Ag/AgCl electrode. The potentiometric response of the sensor to chloride in synthetic concrete pore solutions was systematically studied, and the polarization performance was also evaluated. The results show a good linear relationship between the potential reading of the sensor and the logarithm of chloride activity (concentration ranges from 0.05 to 5.0 M), and the potential value remains stable with increasing immersion time. The existence of K(+), Ca(2+), Na(+) and SO(4) (2-) ions have little influence on the potentiometric response of the sensor to chloride, but the pH has a significant influence on the potential value of the sensor at low chloride concentration. The potential reading of the sensor increases linearly with the solution temperature over the range from 5 to 45 °C. Meanwhile, an excellent polarization behavior is proven by galvanostatic and potentiodynamic tests. All of the results reveal that the developed sensor has a great potential for monitoring chloride ions in concrete environments. PMID:22163467

  14. 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

    2015-01-01

    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.

  15. Reaction of cobalt molybdophosphate with alcoholic solutions of tetraethoxysilane and oxozirconium(IV) chloride

    International Nuclear Information System (INIS)

    Interaction of cobalt molybdophosphate with alcohol solutions of tetraethoxysilane and oxozirconium chloride was studied using the methods of IR spectroscopy and thermal analysis with an aim of ascertaining the potentiality of the reagents application for production of thermochrome materials. It was ascertained that as a results of interaction between cobalt molybdophosphate and tetraethoxysilane solution the heteropolyanion [PMo12O40]3- was transformed into lacunar form [HxPMo11O39]7-x. The hydrolysis processes occurring in compositions with oxozirconium chloride does not permit stabilizing the structure of the heteropolycompound responsible for thermochrome transitions

  16. Conductivity of Thionyl Chloride-Lithium Tetrachloroaluminate Solutions

    DEFF Research Database (Denmark)

    Berg, Rolf W.; Hjuler, H. A.; Søndergaard, A. P. L.;

    1989-01-01

    The specific conductivity of solutions of LiAlCl4 dissolved in SOCl2 was determined as a function of composition andtemperature. An analytical expression from which the conductivity can be calculated is given as a function of the molefraction of LiAlCl4 and temperature in the ranges from 0° to 0...

  17. Rheology and viscosity scaling of gelatin/1-allyl-3-methylimidazolium chloride solution

    Science.gov (United States)

    Qiao, Congde; Li, Tianduo; Zhang, Ling; Yang, Xiaodeng; Xu, Jing

    2014-05-01

    Gelatin/1-allyl-3-methylimidazolium chloride solutions are prepared by using the ionic liquid 1-allyl-3-methylimidazolium chloride as solvent. The rheological properties of the gelatin solutions have been investigated by steady shear and oscillatory shear measurements. In the steady shear measurements, the gelatin solutions with high concentration show a shear-thinning flow behavior at high shear rates, while another shear thinning region can be found in the dilute gelatin solutions at low shear rates. The overlap concentration of gelatin in [amim]Cl is 1.0 wt% and the entanglement concentration is a factor of 4 larger (4.0 wt%). The high intrinsic viscosity (295 mL/g) indicates that the gelatin chains dispersed freely in the ionic liquid and no aggregation phenomenon occurs in dilute gelatin solution. The frequency dependences of modulus changed obviously with an increase in gelatin concentration. The empirical time-temperature superposition principle holds true at the experimental temperatures.

  18. Iron-Catalyzed Acylation of Polyfunctionalized Aryl- and Benzylzinc Halides with Acid Chlorides.

    Science.gov (United States)

    Benischke, Andreas D; Leroux, Marcel; Knoll, Irina; Knochel, Paul

    2016-08-01

    FeCl2 (5 mol %) catalyzes a smooth and convenient acylation of functionalized arylzinc halides at 50 °C (2-4 h) and benzylic zinc chlorides at 25 °C (0.5-4 h) with a variety of acid chlorides leading to polyfunctionalized diaryl and aryl heteroaryl ketones. PMID:27457108

  19. Stability of Melphalan in 0.9% Sodium Chloride Solutions Prepared in Polyvinyl Chloride Bags for Intravenous Injection.

    Science.gov (United States)

    Desmaris, Romain-Pacôme; Mercier, Lionel; Paci, Angelo

    2015-09-01

    Melphalan is an alkylating agent frequently used in an intravenous formulation to treat hematologic malignancies and solid tumors in both adults and children. According to the manufacturer, melphalan is stable in sterile 0.9% sodium chloride for 90 min at room temperature (RT). Several authors have studied the stability of different concentrations of melphalan; however, most were not adapted to the current manufacturing process applied in pharmaceutical centralized units. This study was conducted to determine the stability of melphalan in 0.9% sodium chloride solutions at concentrations used for intravenous injection in practice. Melphalan is commonly prepared in diluted solutions ranging from 2 to 4 mg/ml for the treatment of adult patients and at lower concentrations (down to 0.5 mg/ml) for pediatric use. Accordingly, these were the three concentrations chosen for this study. Melphalan concentrations were measured with high-performance thin-layer chromatography (HPTLC). At RT, admixtures prepared at 4 mg/ml were stable for up to 8 h without protection from light; however, at lower concentrations, such as 0.5 and 2 mg/ml, stability did not exceed 2 h. When refrigerated, melphalan was stable for 24 h at 2 mg/ml; however, at 0.5 and 4 mg/ml, the drug was not stable. Melphalan solutions present with limited stability at 0.5, 2, and 4 mg/ml and are not adapted for delayed administration in pharmaceutical centralized units. However, at 4 mg/ml and at RT, a stability of 8 h is very interesting in practice and allows sufficient time for preparation, pharmaceutical control, transport, and administration.

  20. Chemical behaviour of plutonium in aqueous chloride solutions

    International Nuclear Information System (INIS)

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

  1. Experimental study of concentrated solutions containing sodium and chloride pollutants in SG flow restricted areas

    International Nuclear Information System (INIS)

    In steam generators, the hideout processes occur in flow restricted areas. Non volatile pollutants, i.e. species less soluble in the vapour phase than in the liquid water phase, accumulate such as sodium hydroxide or sodium chloride. The thermodynamic equilibrium between these two phases is described in terms of liquid-vapour equilibrium constants for soluble species and boiling constant for the solvent. The presented experimental investigation has been realised with the EVA device: the boiling pressure evolution has been measured during the hideout process of sodium hydroxide and sodium chloride aqueous solutions. The results clearly demonstrated that high sodium hydroxide aqueous solutions are thermodynamically possible while with sodium chloride, it seems that precipitation occurs before. (authors)

  2. Acidizing carbonate reservoirs with chlorocarboxylic acid salt solutions

    Energy Technology Data Exchange (ETDEWEB)

    Richardson, E.A.; Scheuerman, R.F.; Templeton, C.C.

    1978-10-31

    A carbonate reservoir is acidized slowly by injecting an aqueous solution of a chlorocarboxylic acid salt so that the rate of the acidization is limited to the rate at which an acid is formed by the hydrolyzing of the chlorocarboxylate ions. The rate at which a chlorocarboxylic acid salt hydrolyzes to form an acid provides the desired rate of acid-release. A more complete acid-base reaction by chloroacetic acid, as compared to formic, acetic, and proprionic, is due to its being a much stronger acid. The pKa of chloroacetic acid is 2.86, whereas that of formic acid is 3.75, and that of acetic acid is 4.75. The pKa of a solution of a weak acid is the pH exhibited when the concentration of undissociated acid equals the concentration of the acid anion. 14 claims.

  3. Solid solution barium–strontium chlorides with tunable ammonia desorption properties and superior storage capacity

    DEFF Research Database (Denmark)

    Bialy, Agata; Jensen, Peter Bjerre; Blanchard, Didier;

    2015-01-01

    with spray drying and in situ thermogravimetric and structural characterization, we synthesize a range of new, stable barium-strontium chloride solid solutions with superior ammonia storage densities. By tuning the barium/strontium ratio, different crystallographic phases and compositions can be obtained...

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

    OpenAIRE

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

    2016-01-01

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

  5. Inclusion polymerization of vinyl chloride monomer in deoxycholic acid host via {gamma}-ray irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Chirachanchai, S.; Kumkrong, A. [The Petroleum and Petrochemical College, Chulalongkorn University, Bangkok (Thailand); Ishida, Hatsuo [Department of Macromolecular Science, Case Western Reserve University, Cleveland, OH (United States)

    2000-03-01

    Inclusion polymerization of vinyl chloride monomer (VCM) was studied in the system of 3{alpha}, 12{alpha} -dihydroxy-5{beta}-cholan-24-oic acid (deoxycholic acid, DCA). DCA-VCM inclusion compound system was originally prepared by guest intercalation technique in DCA guest free crystal. The inclusion polymerization of DCA-VCM by {gamma}-irradiation at total dose 2 Mrad, gives a syndiotactic rich polyvinyl chloride (PVC) as can be confirmed by FT-IR and FT-NMR. (author)

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

    Science.gov (United States)

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

    2010-02-01

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

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

    International Nuclear Information System (INIS)

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

  8. [Glucose-fatty acids cycle in cobalt chloride-induced oxidative stress in rats].

    Science.gov (United States)

    Kaliman, P A; Okhrimenko, S M

    2005-01-01

    It was found that the glucose-fatty acids cycle functioned under the oxidative stress, caused by injection of cobalt chloride solution in albino rats. This cycle promoted the adaptation of metabolism and rehabilitated the homeostasis under extreme conditions. Its functioning was regulated by prolonged (during 2-24 hours) rise in activity of amino acids catabolism enzymes (e.g. tyrosine aminotransferase, arginase) and activation of glyconeogenesis after the mobilisation of liver glycogen. This contributed to increase in glucose and free fatty acids contents in blood. The latter is additionally provided by lipid mobilisation under stress. Tyrosine aminotransferase activation occurred both on the transcription level and by enabling of other mechanisms, which probably concerned the stabilisation of this enzyme. Preliminary injection of alpha-tocopherol in vivo significantly decreased the rise in tyrosine aminotransferase and arginase activities and the rate of erythrocyte hemolysis but did not disable them in full. This made evident that in regulation of the glucose-fatty acids cycle not only active metabolites of oxygen but also Co ions were directly enabled. PMID:16335249

  9. Separation of hafnium from zirconium in their tetrachloride solution in molten alkali metal chlorides

    Energy Technology Data Exchange (ETDEWEB)

    Salyulev, A.B.; Kudyakov, V.Ya.; Smirnov, M.V.; Moskalenko, N.I. (AN SSSR, Sverdlovsk. Inst. Ehlektrokhimii)

    1984-08-01

    The coefficient of HfCl/sub 4/ and ZrCl/sub 4/ separation in the process of vapour sublimation from their solutions in molten NaCl, KCl, CsCl, NaCl-KCl and NaCl-CsCl equimolar mixtures is found to vary in the series from approximately 1.10 to approximately 1.22 and practically not to depend on the temperature (in the 600-910 deg) range and concentration (2-25 mol.% ZrCl/sub 4/+HfCl/sub 4/). HfCl/sub 4/ and ZrCl/sub 4/ are shown to form almost perfect solutions with each other, which in their turn form imperfect solutions with molten alkali metal chlorides, with the strength of hafnium complex chloride anions increasing higher than that of zirconium in the series from NaCl to CsCl.

  10. Separation of hafnium from zirconium in their tetrachloride solution in molten alkali metal chlorides

    International Nuclear Information System (INIS)

    The coefficient of HfCl4 and ZrCl4 separation in the process of vapour sublimation from their solutions in molten NaCl, KCl, CsCl, NaCl-KCl and NaCl-CsCl equimolar mixtures is found to vary in the series from approximately 1.10 to approximately 1.22 and practically not to depend on the temperature (in the 600-910 deg) range and concentration (2-25 mol.% ZrCl4+HfCl4). HfCl4 and ZrCl4 are shown to form almost perfect solutions with each other, which in their turn form imperfect solutions with molten alkali metal chlorides, with the strength of hafnium complex chloride anions increasing higher than that of zirconium in the series from NaCl to CsCl

  11. Acetic acid extraction from aqueous solutions using fatty acids

    NARCIS (Netherlands)

    IJmker, H.M.; Gramblicka, M.; Kersten, S.R.A.; Ham, van der A.G.J.; Schuur, B.

    2014-01-01

    A major challenge for production of acetic acid via bio-based routes is cost-effective concentration and purification of the acetic acid from the aqueous solutions, for which liquid–liquid extraction is a possible method. A main challenge in extraction of acetic acid from dilute aqueous solutions is

  12. Anodic behavior of hafnium in water-alcohol solutions of sodium chloride

    International Nuclear Information System (INIS)

    The mechanism of hafnium anodic solution in the systems: sodium chloride-isopropanol-glycerin-water is clarified. The corrosiveness of the studied electrolytes relative to hafnium is evaluated. It is shown that the solution mechanism changes with increase in the potential: after reaching the 0.4-0.5 V potential the process diffusion control changes for kinetic one. The hafnium anodic solution also changes with increase of temperature in the electrolyte wherein the treatment is conducted. In this case the change in the composition and properties of the change in the composition and properties of the oxide film on the metal constitute surface the basis of the mechanism change

  13. Electrochemical Behavior of Nano-grained Pure Copper in Dilute Alkaline Solution with Chloride Ion Trace

    Science.gov (United States)

    Fattah-Alhosseini, Arash; Imantalab, Omid; Attarzadeh, Farid Reza

    2016-10-01

    Effect of nano-grained structure on the interface behavior of pure copper in 0.01M KOH solution with chloride ion trace is investigated by various electrochemical techniques. Nano-grained structure was achieved by accumulative roll bonding (ARB) technique. Before any electrochemical measurements, microstructure was evaluated by means of optical microscopy and transmission electron microscopy (TEM). TEM observations showed that nano-grains (with an average size of below 100 nm) appeared after eight passes of ARB. Polarization curves revealed that increasing chloride ion concentration leads to a decrease in the corrosion and pitting potentials of both annealed and nano-grained pure copper samples. Electrochemical impedance spectroscopy revealed that chloride ion trace lowers passive film resistance and charge-transfer resistance in both annealed and nano-grained samples. Mott-Schottky analysis showed that the surface films formed on annealed and nano-grained samples in KOH solution with and without NaCl addition are of p-type semiconducting behavior. Moreover, this analysis showed that the acceptor density increases by increasing chloride ion concentration.

  14. Corrosion behaviour of WC-Co based hardmetal in neutral chloride and acid sulphate media

    Energy Technology Data Exchange (ETDEWEB)

    Bozzini, B.; Serra, M.; Fanigliulo, A.; Bogani, F. [Lecce Univ. (Italy). Dipt. di Ingegneria dell' Innovazione; Gaudenzi, G.P. de [Harditalia s.r.l. (OMCD Group), Genova (Italy)

    2002-05-01

    A comparative study of the corrosion behaviour of WC-Co based hardmetals with Ni and Cr{sub 3}C{sub 2} additions is carried out. The aggressive environments are neutral and acidic aerated aqueous solutions of NaCl and H{sub 2}SO{sub 4}. This study is based on electrochemical (linear sweep voltammery), compositional (surface EDX analyses, AAS analyses of attack solutions), structural (XRD) and morphological (SEM) investigations. Electrochemical figures of merit were computed from linear sweep voltammograms in order to rank the corrosion behaviour close to free-immersion conditions in the studied environments and with presence of oxidising agents. EDX and XRD analyses allow to accurately characterise the penetration depth of the attack as well as the preferential dissolution of the constituents. Binders containing Ni show a significantly improved corrosion resistance in the studied systems. The amount of Ni in the binder is the single most important factor affecting corrosion performance. Cr{sub 3}C{sub 2} additions to hardmetals with lower-Ni binders cannot balance the effect of Ni, but give an improved resistance in neutral chloride-containing solutions. (orig.)

  15. Corrosion-fatigue lifetime of Aluminium–Copper–Lithium alloy 2050 in chloride solution

    OpenAIRE

    Guérin, Mathilde; Alexis, Joël; Andrieu, Eric; Blanc, Christine; Odemer, Grégory

    2015-01-01

    International audience The fatigue behaviour of Aluminium–Copper–Lithium 2050 alloy under two metallurgical states (T34 and T84) was studied in air for healthy and pre-corroded samples in a 0.7 NaCl solution. The results were compared to those obtained during fatigue–corrosion tests performed in a similar chloride medium. Preliminary corrosion tests demonstrated that the T34 metallurgical state was susceptible to intergranular corrosion, while the T84 metallurgical state was susceptible to...

  16. Passivation of duplex stainless steel in solutions simulating chloride-contaminated concrete

    OpenAIRE

    Takenouti, H.; Soriano, L; Palacín, S.; Gutiérrez, A.; Velasco, F.; Blanco, G; Bautista, A.

    2007-01-01

    Most studies published to date on the corrosion behaviour of stainless reinforcing steel are based on austenitic steel. The market presence of corrugated duplex steel is growing, however. The present study compared passivity in 2205 type duplex and 304 type austenitic stainless steel. Polarization tests in chloride-containing Ca(OH)2 solutions confirmed the exceptional performance of duplex steels. X-ray photoelectronic spectroscopy (XPS) showed that the passive layer generated on duplex stai...

  17. Performance of cellulose acetate butyrate membranes in hyperfiltration of sodium chloride and urea feed solution

    Science.gov (United States)

    Wydeven, T.; Leban, M.

    1973-01-01

    Cellulose acetate butyrate (CAB) membranes are shown to give high salt and urea rejection with water flux of about 3 gallons/sq ft per day at 600 psig. Membranes prepared from a formulation containing glyoxal show a significant increase in flux and decrease in salt and urea rejection with drying time. Zero drying time gives maximum urea and salt rejection and is therefore most suitable for hyperfiltration of sodium chloride and urea feed solution.

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

    OpenAIRE

    Sasahara, K; Nitta, K

    1999-01-01

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

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

    OpenAIRE

    Sasahara, K; Nitta, K

    1999-01-01

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

  20. The Influence of Calcium Chloride Salt Solution on the Transport Properties of Cementitious Materials

    OpenAIRE

    Yaghoob Farnam; Taylor Washington; Jason Weiss

    2015-01-01

    The chemical interaction between calcium chloride (CaCl2) and cementitious binder may alter the transport properties of concrete which are important in predicting the service life of infrastructure elements. This paper presents a series of fluid and gas transport measurements made on cementitious mortars before and after exposure to various solutions with concentrations ranging from 0% to 29.8% CaCl2 by mass. Fluid absorption, oxygen diffusivity, and oxygen permeability were measured on morta...

  1. Threshold Chloride Concentration of Stainless Steels in Simulated Concrete Pore Solution

    OpenAIRE

    Wang, Hailong; Ling, Jiayan; Sun, Xiaoyan

    2016-01-01

    To evaluate whether stainless steel can replace carbon steel as rebar in reinforced concrete structures exposed to aggressive environment, the threshold chloride concentration of carbon steel, austenitic and duplex stainless steels were experimentally studied in this paper. The solutions with pH ranging from 9.5 to 13.6 were used herein to simulate the pore liquids in both alkaline and carbonated concretes. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) tests we...

  2. Kinetics of the oxidative hydroxylation of sodium hypophosphite in the presence of copper (II chloride modified by humic (fulvo- acid

    Directory of Open Access Journals (Sweden)

    Zhaksyntay Kairbekov

    2012-12-01

    Full Text Available It was established that in soft conditions (50-70oC, PO2 = 1 atm sodium hypophosphite effectively is oxidized by oxygen in water solutions of copper(II chloride  to give mainly a phosphorous acid. Humic (fulvo- acid was extracted from brown coal of domestic deposit Kiyakty. For determination of optimum parameters of fulvo-acid extraction the laboratory experiments were carried out using the method of experiment planning. The kinetics, the intermediate and final products, optimal conditions of new catalytic reaction of NaH2PO2 oxidation by oxygen in water solution were defined by kinetics, volumometry, redox-potentiometry and a titration.

  3. Liquid-Liquid Extraction and Separation of Co (II) and Ni(II) from Chloride Medium by bis (2,4,4-trimethylpentyl) dithio phosphinic acid in Kerosene

    International Nuclear Information System (INIS)

    The extraction of Co(II) and Ni(II) from chloride solutions using bis (2,4,4-trimethylpentyl) dithio phosphinic acid (CYANEX 301) in kerosene has been investigated. The various factors affecting the extraction process of Co(II) and Ni(II) by the investigated extractant such as contact time, ph, extractant and metal ion concentration as well as temperature, are separately investigated. The stripping of the extracted metal ions from loaded organic solutions is also carried out using different stripping reagents. The results were used to assess the conditions for maximum Co(II)/Ni(II) separation from chloride medium using CYANEX 301

  4. Pitting of steam-generator tubing alloys in solutions containing thiosulfate and sulfate or chloride.

    Science.gov (United States)

    Zhang, William; Carcea, Anatolie G; Newman, Roger C

    2015-01-01

    The pitting of nuclear steam generator tubing alloys 600, 690 and 800 was studied at 60 °C using dilute thiosulfate solutions containing excess sulfate or (for Alloy 600) chloride. A potentiostatic scratch method was used. In sulfate solutions, all alloys pitted at low potentials, reflecting their lack of protective Mo. The alloys demonstrated the most severe pitting at a sulfate : thiosulfate concentration ratio of ∼40. Alloy 600 pitted worst at a chloride : thiosulfate ratio of ∼2000. The results are interpreted through the mutual electromigration of differently charged anions into a pit nucleus, and differences in the major alloy component. PMID:25898311

  5. Corrosion Behavior of Compocasted ZA27/SiCp Composites in Sodium Chloride Solution

    OpenAIRE

    Bobić, B.; I. Bobić; A. Vencl; M. Babić; S. Mitrović

    2016-01-01

    The corrosion behavior of particulate ZA27/SiCp composites in an aerated sodium chloride solution was studied. The composites were synthesized via compocasting with addition of 1, 3 and 5 wt.% SiC particles in the matrix alloy. Composite samples were immersed for 30 days in the 3.5 wt.% NaCl solution open to the atmospheric air. Surface appearance and microstructure of the composites were examined by means of optical microscopy and scanning electron microscopy, while corrosion rates of the co...

  6. A Model Approach for Finding Cleaning Solutions for Plasticized Poly(Vinyl Chloride) Surfaces of Collections Objects

    DEFF Research Database (Denmark)

    Sanz Landaluze, Jon; Egsgaard, Helge; Morales Munoz, Clara;

    2014-01-01

    solutions for the plasticized poly(vinyl chloride) used in the study was found. In addition, a specific method to tailor cleaning mixtures for plasticized poly(vinyl chloride) objects was developed by means of Hildebrand solubility parameters and the formulation of a Plasticizer Index calculated...

  7. Chloride transport and its sensitivities to different boundary conditions in reclaimed soil solutions filled with fly ash

    Institute of Scientific and Technical Information of China (English)

    Xiao-Yang CHEN; Jia-Ping YAN; Shi-Wen ZHANG

    2013-01-01

    Chloride ion transport in reclaimed soil solutions filled with fly ash (FA) was investigated by measuring the hydraulic parameters (i.e.water retention curves and hydraulic conductivity) of three substrates,namely GSL,GFA,and CFA.Similar simulations were carried out under certain weather conditions.The different boundary conditions of chloride transport were also discussed from FA texture,cover soil thickness,groundwater table level,and initial chloride concentration.Furthcrmore,the sensitivities of chloride ions to these effect factors were analyzed.The results show that the different top soil thickness and initial chloride concentration have no effect on salinity of topsoil solution in the monitoring points,but they can clearly change the chloride concentration of FA layers.The sensibilities from top soil thickness and initial chloride content are exceedingly weak to the salinity balance based on two dimensions of the time and concentration.While the different FA texture and groundwater table not only affect the salinity equilibrium process of the whole reclaimed soil profile,but also change its balance state.Generally,coarse FA particles and high groundwater table can defer the salinity balance process of the reclaimed soil solution,and they also increase the chloride concentration of FA layer solutions,and even topsoil ones.

  8. Kinetics of the oxidative hydroxylation of tetraphosphorus in the presence of copper(II chloride modified by humic (fulvo- acid

    Directory of Open Access Journals (Sweden)

    Zhaksyntay Kairbekov

    2012-12-01

    Full Text Available It was established that in mild conditions (50-70 oC, РО2= 1 atm white phosphorus effectively is oxidized by oxygen in water-toluene solutions of copper(II chloride modified by humic (fulvo- acid to give mainly phosphoric acid. Humic (fulvo- acid was extracted from brown coal of domestic deposit Kiyakty. For determination of optimum parameters of fulvo-acid extraction the laboratory experiments were carried out using the method of experiment planning. The kinetics, intermediate and final products, optimum conditions of new catalytic reaction of P4 oxidation by oxygen in water medium were defined by kinetics, volumometry, redox-potentiometry, 31Р{1Н} NMR spectroscopy and  titration. 

  9. Chemical modification of Sago starch by solvent less esterification with fatty acid chlorides

    International Nuclear Information System (INIS)

    Sago starch was chemically modified by esterification reaction with fatty acid chlorides to produce a non-polar sago ester in the absence of an organic solvent. The sago esters were prepared by first pretreatment of sago starch with excess formic acid at 90 degree Celsius for 40 minutes followed by acetylation with acid chloride (octanoyl and lauroyl chlorides). The maximum yields of 80 % and 73 % with the same degree of substitution (DS) of 1.2 for octanoate and lauroate sago esters were obtained respectively. The presence of ester carbonyl group in the FT-IR spectra of the ester products showed that the sago starch has been esterified. The intensities of carbonyl and methyl peaks were decreased with the increasing of DS. (author)

  10. 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...

  11. Extraction Mechanism of La3+ from Hydrochloric Acid Solution Using Cyanex 302

    Institute of Scientific and Technical Information of China (English)

    乌东北; 牛春吉; 李德谦

    2004-01-01

    The solvent extraction of La3+ from hydrochloric acid solutions was investigated using bis(2, 4, 4-trimethylpentyl) monothiophosphinic acid(Cyanex 302, HL) as an extractant. The effect of equilibrium of aqueous acidity on extraction of La3+ using Cyanex 302 in different diluents was discussed. The effects of extractant concentration and chloride ion on the extraction reaction were also studied. Stoichiometry of the extraction reactions and the nature of metal complexes formed were determined using slope analysis technique and IR measurement.

  12. Synergic Mechanism of an Organic Corrosion Inhibitor for Preventing Carbon Steel Corrosion in Chloride Solution

    Institute of Scientific and Technical Information of China (English)

    LIU Zhiyong; YU Lei; LI Qingzhong

    2015-01-01

    The inhibition effect of dimethylethanolamine (DMEA) and its composite with carboxylic acid was studied with the electrochemical tests. The experimental results indicate that DMEA is not a good inhibitor but the composite of DMEA with caprylic acid exhibits excellent inhibiting efficiency. The synergic mechanism of the organic corrosion inhibitors (OCIs) was studied with quantum chemical calculations. It is found that the DMEA forms a quaternary ammonium salt with the proton in carboxylic acid, and a cyclic complex formed between the salt and Fe may be responsible for the enhancement of inhibiting efficiency. The possible hydrogen bond formed between DMEA and carboxylic acid is not enough for the inhibiting effect. This work is helpful to proposing theoretical interpretation as well as developing a functional organic inhibitor to improve the durability of reinforced concrete contaminated with chloride.

  13. 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.

  14. Effects of solution pH and synthetic method on destabilization process of polytitanium-silicate-chloride.

    Science.gov (United States)

    Huang, Xin; Gao, Baoyu; Sun, Yangyang; Yue, Qinyan; Wang, Yan; Li, Qian

    2016-07-01

    Effect of solution pH on coagulation performance and flock properties of a novel inorganic polymer coagulant-polytitanium-silicate-chloride (PTSC) in humic acid-kaolin water treatment was investigated in this work. PTSC was synthesized by two approaches: composite and co-complexion, denoted as PTSCm and PTSCc respectively. The effect of the synthetic method was also considered. Results indicated that turbidity and DOM removal were improved by addition of polysilicic acid, especially under acidic condition. PTSCc achieved slightly better DOM removal than that of PTSCm. Flocks formed under acidic condition was smaller than those form under alkaline condition. In addition, flocks formed by PTSCc were larger than PTSCm flocks. Results also indicated that flock strength and recovery ability was slightly improved by the addition of PSiA. Moreover, under acidic condition, PTSC flocks had larger fractal dimension with more compact structure, especially for PTSCm flocks. In contrast, they were looser compared with PTC flock, especially for PTSCm flocks under neutral and alkaline conditions. PMID:26994354

  15. STUDY OF CHEMICAL INTERACTION OF MAGNESIA CEMENT WITH HIGH CONCENTRATION MAGNESIUM CHLORIDE SOLUTIONS

    Directory of Open Access Journals (Sweden)

    DEREVIANKO V. N.

    2015-10-01

    Full Text Available Problem statement. In activating MgO by electrolyte salts, as a result of formation of non water-resist magnesium silicate hydrate are obtained the durable cement stone having the low water-resist. I. P. Vyrodov considers [9; 5], that magnesia cement curing in mixing with sufficiently concentrated (C > 20 % solutions MgCl2 is caused with the crystallization of oxyhydrochloride composition: 3MgO∙MgCl2∙11Н2О, 5MgO∙MgCl2∙13Н2О and 7MgO∙MgCl2∙15Н2О. In the lower concentration parts of MgCl2 solution is formed a transitional compound of Mg[(OHnCl2-n] with isomorphous Mg(OH2 structure. At very low Cl concentration only Mg(OH2 is practically formed. Purpose. The Formation of water-resist magnesium silicate hydrates for obtaining of fast curing and solid structure of the magnesia stone. Conclusion. The dependence of the formation of the magnesia stone from the ratio (MgO/MgCl2 of the magnesia cement (MgO and the magnesium chloride solution (MgCl2 of different density has been identified in order to obtain the best content for oxyhydrochloride 3MgO•MgCl2•11Н2О, 5MgO•MgCl2•13Н2О and magnesium hydroxide (Mg(OH2. In putting into the system MgO∙–∙H2О of the silicic acid or fine ground quartz grains with size of less than 20 – 30 microns, over 1 month for the magnesium silicate hydrates formation is needed, where from 2 to 5 % of the total number of newgrowths are created. The study is proved by the expert opinion, that magnesium silicate hydrates do not have binding properties, unlike calcium silicate hydrates, and the main role in the system curing is played with the Mg(OH2 gel recrystallization, which provides the acceptable stone strength (R ≈ 30MPa in a few years. It has been also established, that in mixing of cement with low concentration MgO solutions of less than 1,5 mol/l (or 13% 1,1g/sm3, the final product in the stone structure is Mg(OH2. With increasing the sealer (MgCl2 solution there is formed by turn in

  16. NIR Spectroscopic Properties of Aqueous Acids Solutions

    Directory of Open Access Journals (Sweden)

    Mohd Zubir MatJafri

    2012-06-01

    Full Text Available Acid content is one of the important quality attributes in determining the maturity index of agricultural product, particularly fruits. Despite the fact that much research on the measurement of acidity in fruits through non-destructive spectroscopy analysis at NIR wavelengths between 700 to 1,000 nm has been conducted, the same response towards individual acids is not well known. This paper presents NIR spectroscopy analysis on aqueous citric, tartaric, malic and oxalic solutions through quantitative analysis by selecting a set of wavelengths that can best be used to measure the pH of the solutions. The aquaphotomics study of the acid solutions has generated R2 above 0.9 for the measurement of all acids. The most important wavelengths for pH are located at 918–925 nm and 990–996 nm, while at 975 nm for water.

  17. CATALYTIC ESTERIFICATION OF CARBOXYLIC ACIDS WITH ALCOHOLS BY SULFO—POLYVINYL CHLORIDE

    Institute of Scientific and Technical Information of China (English)

    YuShanxin; ZHAOZongbao; 等

    1993-01-01

    Polyvinyl Chloride reacted with chlorosulfonic acid to from a polymer catalyst PVC-SO3H.This polymer catalyst was found to have high activity for resterification reaction between carboxylic acids and alcohols.This paper deals with the conditions in synthesis of n-butlyacetate catalyzed with PVC-SO3H.The PVC-SO3H was used as a catalyst for preparing 11 esters of acetic acid,propionic acid and butyric acid with the yields of 82-92%.

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

    Science.gov (United States)

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

    2004-11-01

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

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

    Directory of Open Access Journals (Sweden)

    Shouwei Jian

    2016-01-01

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

  20. Comparison of Sodium Chloride Tablets-Induced, Sodium Chloride Solution-Induced, and Glycerol-Induced Hyperhydration on Fluid Balance Responses in Healthy Men.

    Science.gov (United States)

    Savoie, Félix A; Asselin, Audrey; Goulet, Eric D B

    2016-10-01

    Savoie, FA, Asselin, A, and Goulet, EDB. Comparison of sodium chloride tablets-induced, sodium chloride solution-induced, and glycerol-induced hyperhydration on fluid balance responses in healthy men. J Strength Cond Res 30(10): 2880-2891, 2016-Sodium chloride solution-induced hyperhydration (NaCl-SolIH) is a powerful strategy to increase body water before exercise. However, NaCl-SolIH is associated with an unpleasant salty taste, potentially dissuading some athletes from using it and coaches from recommending it. Therefore, we evaluated the hyperhydrating potential of sodium chloride tablets-induced hyperhydration (NaCl-TabIH), which bypasses the palatability issue of NaCl-SolIH without sacrificing sodium chloride content, and compared it to NaCl-SolIH and glycerol-induced hyperhydration (GIH). Sixteen healthy males (age: 21 ± 2 years; fat-free mass (FFM): 65 ± 6 kg) underwent three, 3-hour long passive hyperhydration protocols during which they drank, over the first 60 minutes, 30-ml·kg FFM of an artificially sweetened solution. During NaCl-TabIH, participants swallowed 7.5, 1 g each, sodium chloride tablets with every liter of solution. During NaCl-SolIH, an equal quantity of sodium chloride tablets was dissolved in each liter of solution. With GIH, the glycerol concentration was 46.7 g·L. Urine production, fluid retention, hemoglobin, hematocrit, plasma volume, and perceptual variables were monitored throughout the trials. Total fluid intake was 1948 ± 182 ml. After 3 hour, there were no significant differences among treatments for hemoglobin, hematocrit, and plasma volume changes. Fluid retention was significantly greater with NaCl-SolIH (1150 ± 287 ml) than NaCl-TabIH (905 ± 340 ml) or GIH (800 ± 211 ml), with no difference between NaCl-TabIH and GIH. No differences were found among treatments for perceptual variables. NaCl-TabIH and GIH are equally effective, but inferior than NaCl-SolIH. NaCl-TabIH represents an alternative to hyperhydration induced

  1. Comparison of Inactivation and Unfolding of Calf Intestinal Alkaline Phosphatase in Guanidinium Chloride Solution

    Institute of Scientific and Technical Information of China (English)

    张英侠; 闫淑莲; 刘永利; 席宏伟; 周海梦

    2002-01-01

    The changes in activity and unfolding of calf intestinal alkaline phosphatase (CIP) during denaturation in guanidinium chloride solutions of different concentrations were investigated using ultraviolet difference absorption spectra and fluorescence emission spectra. Unfolding and inactivation rate constants were measured and compared. The inactivation course is much faster than that of unfolding, which suggests that the active site of CIP containing two zinc ions and one magnesium ion is situated in a limited and flexible region of the enzyme molecule, which is more fragile to the denaturant than the protein as a whole.

  2. Calcium ion activity in physiological salt solutions: influence of anions substituted for chloride

    DEFF Research Database (Denmark)

    Christoffersen, Gert Rene Juul; Skibsted, Leif H

    1975-01-01

    1. Substitution by different anions for chloride in physiological salt solutions leads to binding between Ca2+ and the anion. Experiments designed to test effects of Cl- therefore often show mixed effects of changes in Cl- and Ca2+ activity.   2. This mixed effect is demonstrated in neurons...... of the snail, Helix pomatia: current-voltage characteristics and membrane potential are described during reduction of extracellular Cl- using different anions as substitutes. Methylsulphate is concluded to be the best substitute in this preparation. 3. The association constants for the binding of Ca2...

  3. Pitting corrosion of friction stir welded aluminum alloy thick plate in alkaline chloride solution

    Energy Technology Data Exchange (ETDEWEB)

    Xu Weifeng, E-mail: xwf1982@mail.nwpu.edu.c [School of Materials and Engineering, Northwestern Polytechnical University, Xi' an 710072 (China); Liu Jinhe; Zhu Hongqiang [School of Materials and Engineering, Northwestern Polytechnical University, Xi' an 710072 (China)

    2010-03-01

    The pitting corrosion of different positions (Top, Middle and Bottom) of weld nugget zone (WNZ) along thickness plate in friction stir welded 2219-O aluminum alloy in alkaline chloride solution was investigated by using open circuit potential, cyclic polarization, scanning electron microscopy and atomic force microscope. The results indicate that the material presents significant passivation, the top has highest corrosion potential, pitting potential and re-passivation potential compared with the bottom and base material. With the increase of traverse speed from 60 to 100 mm/min or rotary speed from 500 to 600 rpm, the corrosion resistance decreases.

  4. Corrosion cracking of Fe-Cr-Ni stainless steels in chloride solutions

    International Nuclear Information System (INIS)

    Tendency to chromium-nickel stainless steels to corrosion cracking in hot solutions of chlorides is connected with the presence or possibility of formation (in the process of deformation) of alpha-gamma phase boundary. Passive oxide film over the (α-γ) phase boundary is mostly defective. However, effect of defectness in the passive film on development of corrosion-mechanical rupture of the metal crystal lattice (crack growth) can manifest itself only at simultaneous presence of expanding stresses on the metal (driving thes zone apart), because of the narrow character of the this zone

  5. Pitting corrosion of friction stir welded aluminum alloy thick plate in alkaline chloride solution

    International Nuclear Information System (INIS)

    The pitting corrosion of different positions (Top, Middle and Bottom) of weld nugget zone (WNZ) along thickness plate in friction stir welded 2219-O aluminum alloy in alkaline chloride solution was investigated by using open circuit potential, cyclic polarization, scanning electron microscopy and atomic force microscope. The results indicate that the material presents significant passivation, the top has highest corrosion potential, pitting potential and re-passivation potential compared with the bottom and base material. With the increase of traverse speed from 60 to 100 mm/min or rotary speed from 500 to 600 rpm, the corrosion resistance decreases.

  6. Poly(vinyl chloride) polyacrylonitrile composite membranes for the dehydration of acetic acid

    NARCIS (Netherlands)

    Koops, G.H.; Nolten-Oude Hendrikman, J.A.M.; Mulder, M.H.V.; Smolders, C.A.

    1993-01-01

    Composite membranes have been prepared consisting of a poly(vinyl chloride) (PVC) top layer on either a dense polyacrylonitrile (PAN) layer (bi-layer membrane) or a porous PAN support layer (normal composite membrane) and studied with respect to the dehydration of acetic acid. Especially, the influe

  7. A convenient catalyst system for microwave accelerated cross-coupling of a range of aryl boronic acids with aryl chlorides

    Directory of Open Access Journals (Sweden)

    Milton Edward J

    2007-05-01

    Full Text Available Abstract A convenient microwave accelerated cross-coupling procedure between aryl chlorides with a range of boronic acids has been developed. An explanation for the low reactivity of highly fluorinated boronic acids in Suzuki coupling is provided.

  8. Sorption recovery of copper (II and zinc (II from chloride aqueous solutions

    Directory of Open Access Journals (Sweden)

    Kononova Olga N.

    2014-01-01

    Full Text Available The present investigation is devoted to simultaneous sorption recovery of copper (II and zinc (II ions on some commercial anion exchangers with different physical-chemical properties. The initial concentrations of zinc and copper were 1-3 mmol L-1 and the recovery was carried out in 0.01 M and 2 M hydrochloric acid solutions. It was shown that the investigated anion exchangers possess good sorption and kinetic properties. After the recovery of copper and zinc from strong acidic solutions, their selective elution was carried out by means of 2 M hydrochloric acid solution (zinc recovery and 2 M ammonia solution (copper recovery. In weak acidic solutions, copper and zinc were separated during sorption, as zinc sorption did not proceed in this case. The subsequent copper (II elution was carried out by 2 M ammonia solution. The anion exchangers Purolite S985, Purolite A500 and AM-2B can be recommended for zinc and copper recovery from acidic industrial solutions and waste water.

  9. Influence of sodium chloride, pH, and lactic acid bacteria on anaerobic lactic acid utilization during fermented cucumber spoilage

    Science.gov (United States)

    Cucumbers are preserved commercially by natural fermentations in 5% to 8% sodium chloride (NaCl) brines. Occasionally, fermented cucumbers spoil after the primary fermentation is complete. This spoilage has been characterized by decreases in lactic acid and a rise in brine pH caused by microbial ins...

  10. Fatigue behavior of alloy 600 in sodium chloride solution at room temperature

    International Nuclear Information System (INIS)

    Fatigue crack growth (FCG) rates of mill annealed Alloy 600 in NaCI solution were studied by a fracture mechanics test method. Compact tension (CT) specimens were tested under load control with a sinusoidal wave form, in accordance with ASTM specification E647-83, to investigate the effects of environment, load frequency (f), load ratio (R=Pmin/Pmax). The FCG rates of Alloy 600, R=0.1, f=1Hz, were quite similar in air, distilled water, and NaCI (0.6 M, 0.1 M, and 0.001 M) solution at room temperature. Environmental enhancement effect on the FCG rate of Alloy 600 was not significant in NaCI solution. Variations of the load frequency (0.03Hz-3Hz) did not influence the FCG rates of Alloy 600 significantly in air and 0.1 M NaCI solution. The FCG rates of Alloy 600 in air and 0.1 M NaCI solution increased with increasing the load ratio. Compared with the corrosion effects, test results showed that the mechanical effects dominated on the FCG rates of Alloy 600 in chloride solution at room temperature. The SEM fractographs showed that significant striations and transgranular fracture modes were observed on tested specimens. (author)

  11. Investigation of the oxidation of hydrochloric acid in scrubbing solutions containing hydrogen peroxide

    International Nuclear Information System (INIS)

    Oxidation and absorption of nitrogen oxides by a solution containing sulphuric, nitric acids and hydrogen peroxide have been investigated. The oxidation of nitric oxide is dependent among others on hydrogen peroxide concentration total acidity and temperature. The absorption of N O2 by the scrubbing solution (H2 S O4,H N O3 and H2 O2) in all cases studied is not less than 98%. The oxidation of chloride into chlorine gas increases as the concentration of each of hydrochloric acid, nitric oxide and nitric acid increases. On the other hand as the concentration of hydrogen peroxide increases the amount of chlorine gas decreases. The results show that the oxidation of chloride into chlorine gas is mainly due to nitrogen dioxide. 7 fig., 2 tab

  12. Antifungal activity of essential oils when associated with sodium chloride or fatty acids

    OpenAIRE

    Tantatoui-Elaraki, Abdelthafour; Errifi, Aziza

    1994-01-01

    The inhibition of mycelium growth in a Zygorhynchus sp. and an Aspergillus niger isolates was studied. The inhibition rates (IR) caused by 4 essential oils (EO), 5 fatty acids and sodium chloride at various concentrations were determined in Sabouraud Dextrose Agar.
    A synergy of action was observed between sodium chloride at 7.5% and the EO of thyme (0.04%), camomile (0.4%) and mugwort (0.2 and 0.1%) on A. niger and between ...

  13. Stability of buprenorphine, haloperidol and glycopyrrolate mixture in a 0.9% sodium chloride solution.

    Science.gov (United States)

    Jäppinen, A; Kokki, H; Naaranlahti, T J; Rasi, A S

    1999-12-01

    Combinations of opioids and adjuvant drug solutions are often used in clinical practice while little information is available on their microbiological or chemical stability. Currently there are no commercially available, prepacked, ready-to-use epidural or subcutaneous mixtures. Thus, epidural and subcutaneous analgesic mixtures must be prepared in the pharmacy on an as-needed basis. Such mixtures are typically used for the treatment of severe pain in cancer patients. The aim of this study was to investigate the microbiological and chemical stability of a buprenorphine, haloperidol and glycopyrrolate mixture in a 0.9% sodium chloride solution. A high performance liquid chromatographic (HPLC) method and pH-meter were used to conduct the analyses. Antimicrobial activity of each component was studied by an agar dilution method. According to the results from the chemical and microbiological stability studies, this mixture can be stored in polypropylene (PP) syringes and polyvinyl chloride (PVC) medication cassettes for at least 30 days at either 21 degrees C or 4 degrees C, and for 16 days in PP syringes at 36 degrees C, and for 9 days in PVC medication cassettes at 36 degrees C. PMID:10658237

  14. Determination of γ-spectrometric parameters for some chloride salt solutions

    International Nuclear Information System (INIS)

    The mass attenuation coefficients, atomic cross-sections and effective atomic numbers are determined for LiCl, NaCl and KCl solutions with contents up to 0.2 g cm-3.The energies used are 0.511, 0.662 and 1.274 keV. The combined results were employed to determine the mass attenuation coefficients and atomic cross-sections of the salts and water in the solutions. The results are compared with the calculated values from elemental data. It was found that the mass attenuation coefficients and corresponding total cross-sections are, in general, less from measurement than from tabulated data, either for water or for the chloride salts

  15. Extraction studies of cobalt (Ⅱ) and nickel (Ⅱ) from chloride solution using PC88A

    Institute of Scientific and Technical Information of China (English)

    LUO Lin; WEI Jian-hong; WU Gen-yi; F. TOYOHISA; S. ATSUSHI

    2006-01-01

    Solvent extraction study of cobalt and nickel were carried out from a chloride solution with a high ratio of Co to Ni using the sodium salt of PC88A as extractant diluted in kerosene. The solution was generated in batches by leaching a tungsten super alloy scraps. The results show that extraction rate of metal ions increases with increase of aqueous phase pH value. The pH0.5 value difference of 1.40 with PC88A indicates the possible separation of cobalt and nickel. Increase of the concentration of the solvent can enhance the percentage extraction of both metal ions. Improvement of temperature is beneficial to extraction separation of cobalt and nickel. Extraction and stripping processes were also studied in a cross-current solvent extraction unit and the results were also given.

  16. Choline Chloride Catalyzed Amidation of Fatty Acid Ester to Monoethanolamide: A Green Approach.

    Science.gov (United States)

    Patil, Pramod; Pratap, Amit

    2016-01-01

    Choline chloride catalyzed efficient method for amidation of fatty acid methyl ester to monoethanolamide respectively. This is a solvent free, ecofriendly, 100% chemo selective and economically viable path for alkanolamide synthesis. The Kinetics of amidation of methyl ester were studied and found to be first order with respect to the concentration of ethanolamine. The activation energy (Ea) for the amidation of lauric acid methyl ester catalyzed by choline chloride was found to be 50.20 KJ mol(-1). The 98% conversion of lauric acid monoethanolamide was obtained at 110°C in 1 h with 6% weight of catalyst and 1:1.5 molar ratio of methyl ester to ethanolamine under nitrogen atmosphere. PMID:26666271

  17. Enhanced corrosion resistance of magnesium alloy AM60 by cerium(III) in chloride solution

    Energy Technology Data Exchange (ETDEWEB)

    Heakal, F. El-Taib, E-mail: fakihaheakal@yahoo.com [Chemistry Department, Faculty of Science, Cairo University, Giza 12613 (Egypt); Shehata, O.S. [Physical Chemistry Department, National Research Centre, Dokki, Giza (Egypt); Tantawy, N.S. [Girl' s College of Arts, Science and Education, Ain Shams University, Asma Fahmi Street, Cairo (Egypt)

    2012-03-15

    Highlights: Black-Right-Pointing-Pointer Corrosion rate of AM60 in Cl{sup -} solution decreases with increasing [Ce{sup 3+}] up to 1 mM. Black-Right-Pointing-Pointer Beyond that level the corrosion rate increases and then stabilizes. Black-Right-Pointing-Pointer The spontaneously formed film characterises by increasing resistance with time. Black-Right-Pointing-Pointer The converted film after 10 d immersion exhibits self-healing in plain Cl{sup -} solution. Black-Right-Pointing-Pointer Ce(III) should be present in the corrodent to form a more compact surface coating. - Abstract: Cerium(III) was utilised to enhance the corrosion resistance of AM60 in NaCl solution. Ce{sup 3+} can suppress corrosion deterioration up to 1.0 mM. Beyond that level corrosion rate increases till a steady value. Surface film resistance increases with time evolution until 24 h, then decreases and stabilizes. The converted film after 240 h immersion exhibits self-healing and thickening when re-exposed to plain chloride solution. SEM and EDX confirmed that when Ce is present as additive in solution, more compact coating is formed better than its presence as a post coating on the alloy surface before being immersed in the corrosive environment.

  18. Rheological Behaviors of Polyacrylonitrile/1-Butyl-3-Methylimidazolium Chloride Concentrated Solutions

    Science.gov (United States)

    Liu, Weiwei; Cheng, Lingyan; Zhang, Hongyan; Zhang, Yumei; Wang, Huaping; Yu, Mingfang

    2007-01-01

    One of the room temperature ionic liquids (RTILs), 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) was chosen to prepare the concentrated solutions of Polyacrylonitrile (PAN). The rheological behaviors of the solutions were measured with rotational rheometry under different conditions, including temperatures, concentration, and molecular weight of PAN. The solutions exhibited shear-thinning behaviors, similar to that of PAN/DMF solutions. The viscosities decreased with the increasing of shear rates. However, the viscosity decreased sharply at high shear rates when the concentration was up to 16wt%. The dependence of the viscosity on temperature was analyzed through the determination of the apparent activation energy. Unusually, the viscosity of solutions of higher concentration is lower than that of lower concentration. Similarly, the viscosity of low molecular weight PAN was higher than high molecular weight PAN at high shear rates. The dynamic rheological measurement indicates the loss modulus is much higher than storage modulus. The trend of complex viscosity is similar with the result of static rheological measurement. The interaction between PAN and ionic liquid [BMIM]Cl was discussed.

  19. Densitometry and ultrasound velocimetry of hyaluronan solutions in water and in sodium chloride solution.

    Science.gov (United States)

    Kargerová, A; Pekař, M

    2014-06-15

    The densities of hyaluronan solutions in water and 0.15M NaCl were measured in the temperature range from 25 to 50°C for the hyaluronan molecular weights from 10 to 1,750 kDa. The density increased linearly with concentration and decreased with temperature. The data were fitted by the equation describing the density as a linear function of concentration and a quadratic function of temperature. The effect of molecular weight was negligible and thus single equation was sufficient to describe all data. The apparent and partial specific volumes were calculated from the density data including their extrapolated values to infinite dilutions. The measurement of ultrasound speed in the same solutions under the same conditions enabled to calculate the compressibility and its dependence on concentration and temperature. The compressibility decreased with both the concentration and the temperature but the effect of the concentration was only slight mild. The compressibility was used to estimate the hydration numbers which slightly decreased with increasing temperature and concentration. The addition of NaCl changed only the numerical values of density and ultrasound velocity while not changing the character of their dependence on temperature and concentration. Measured and calculated data indicate that hyaluronan does not disturb the specific water structure in the studied concentration range and support the idea of the existence of water clusters or nanodroplets hydrating the hyaluronan chains in solution. PMID:24721101

  20. DILUTE SOLUTION BEHAVIOR OF CHITOSAN IN DIFFERENT ACID SOLVENTS

    Institute of Scientific and Technical Information of China (English)

    WANG Wei; WANG Lihua; QIN Wen

    1994-01-01

    Dilute solution behavior of chitosan was studied in formic acid, acetic acid,lactic acid and hydrochloric acid aqueous solution under different pH values. The reduced viscosities, ηsp/C,of chitosan solutions were dependent on the properties of acid and pH value of solvents. For a given chitosan concentration, ηsp/C decreased with the increase of acid concentration, or decreasing pH of solvent, indicating shielding effect of excessive acid similar to adding salt into solution. The stabilities of dilute chitosan solution in formic acid and lactic acid were better than that in acetic acid and hydrochloric acid.

  1. Influence of flexural fatigue on chloride threshold value for the corrosion of steels in Ca(OH){sub 2} solutions

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Linhua, E-mail: hhulhjiang@gmail.com [College of Mechanics and Materials, Hohai University, 1 Xikang Rd., Nanjing, 210098 (China); Hydraulic Engineering Research Center for New Materials and Protection, Jiangsu Province, 1 Xikang Rd., Nanjing, 210098 (China); Liu, Hao; Wang, Yongliang; Zhang, Yan; Song, Zijian; Xu, Jinxia; Jin, Ming; Jiang, Peng; Xu, Yi; Gao, Hailang [College of Mechanics and Materials, Hohai University, 1 Xikang Rd., Nanjing, 210098 (China)

    2015-08-15

    The flexural fatigue was enforced on reinforced concrete beam with stress level of 0.6 and different fatigue life cycles. Steels removed from the beams were soaked in the saturated Ca(OH){sub 2} solution, which was used as a simulated concrete pore solution. The NaCl solution was chosen as the source of chloride ions. The Chloride Threshold Values (CTV) were detected by combining the open-circuit potentials (E{sub corr}) with the corrosion current densities (i{sub corr}), which were obtained by electrochemical impedance spectroscopy (EIS). The changes of microstructure caused by the flexural fatigue were observed by scanning electron microscopy (SEM). The results showed that as the fatigue cycle times increased, the CTV decreased under a certain stress level and range of fatigue life cycles. The grains became finer and cracks appeared on the surface of the steels. While the capacitive arcs under no flexural fatigue decreased gradually with the addition of chloride ions, the ones under flexural fatigue presented no regularity. Cracks at the surface were expanded because of sustaining flexural fatigue, which degenerated the later resistance to chloride ions of the steels. - Highlights: • The influence of flexural fatigue on chloride threshold value was examined. • The chloride threshold values vary with different fatigue life cycles. • The corrosion behavior depends on the surface integrity of the steels.

  2. Influence of flexural fatigue on chloride threshold value for the corrosion of steels in Ca(OH)2 solutions

    International Nuclear Information System (INIS)

    The flexural fatigue was enforced on reinforced concrete beam with stress level of 0.6 and different fatigue life cycles. Steels removed from the beams were soaked in the saturated Ca(OH)2 solution, which was used as a simulated concrete pore solution. The NaCl solution was chosen as the source of chloride ions. The Chloride Threshold Values (CTV) were detected by combining the open-circuit potentials (Ecorr) with the corrosion current densities (icorr), which were obtained by electrochemical impedance spectroscopy (EIS). The changes of microstructure caused by the flexural fatigue were observed by scanning electron microscopy (SEM). The results showed that as the fatigue cycle times increased, the CTV decreased under a certain stress level and range of fatigue life cycles. The grains became finer and cracks appeared on the surface of the steels. While the capacitive arcs under no flexural fatigue decreased gradually with the addition of chloride ions, the ones under flexural fatigue presented no regularity. Cracks at the surface were expanded because of sustaining flexural fatigue, which degenerated the later resistance to chloride ions of the steels. - Highlights: • The influence of flexural fatigue on chloride threshold value was examined. • The chloride threshold values vary with different fatigue life cycles. • The corrosion behavior depends on the surface integrity of the steels

  3. Corrosion of alloy 22 in phosphate ions effect and chloride containing solutions

    International Nuclear Information System (INIS)

    Alloy 22 belongs to Ni-Cr-Mo family. This alloy resists the most aggressive environments for industrial applications, in oxidizing as well as reducing conditions, because exhibits an excellent uniform and localized corrosion resistance in aqueous solution. Because of its outstanding corrosion resistant, this alloy is one of the candidate to be considered for the outer shell of the canister that would contain high level radioactive nuclear wastes in a geological repository. The aim of this work is to study ion phosphate influence over Alloy 22 corrosion behavior under aggressive conditions, such as high temperature and high ion chloride concentration, where this material might be susceptible to crevice corrosion. Two different types of samples were used: cylinder specimens for uniform corrosion behavior studies and Prismatic Crevice Assembly (PCA) specimens for localized corrosion studies. Electrochemical tests were performed in deaerated aqueous solution of 1 M NaCl and 1 M NaCl with different phosphate additions at 90 C degrees and pH near neutral. The anodic film and corrosion products obtained were studied by SEM/EDS. Cyclic Potentiodynamic Polarization (CPP) curves obtained for uniform corrosion studies, showed an increase of the passivity range in phosphate containing solutions. The passive current value was 1 μA/cm2 approximately in all the tests. PCA electrochemical tests, that combined a CPP with a potentiostatic polarization step for 2 hours in between the forward and reverse scan, showed crevice corrosion development in some cases. The repassivation potential value, determined by the intersection of the forward and the reverse scan, increased with phosphate addition. A complete crevice corrosion inhibition effect was found for phosphate concentration higher than 0.3 M. These results indicate that the passivity potential range depend on phosphate presence and might be related with the incorporation of the anion in the passive film. Results of the tests

  4. Choline chloride-based deep eutectic solvents as additives for optimizing chromatographic behavior of caffeic acid

    Energy Technology Data Exchange (ETDEWEB)

    Li, Guizhen; Zhu, Tao; Lei, Yingjie [Tianjin University of Technology, Tianjin (China)

    2015-10-15

    A series of deep eutectic solvents (DESs) were prepared using glycerol and choline chloride (ChCl), and Fourier transform infrared spectrometer (FT-IR) was used to analyze the spectra of glycerol, choline chloride and DESs based on glycerol and choline chloride. Then DESs were used as the additives of mobile phase to optimize chromatographic behavior of caffeic acid in high performance liquid chromatography (HPLC). A 17-run Box-Behnken design (BBD) was employed to evaluate effect of DESs as additives by analyzing the maximum theoretical plate number. Three factors, reaction temperature (60 .deg. C, 80 .deg. C, 100 .deg. C), molar ratio of glycerol and choline chloride (2 : 1, 3 : 1, 4 : 1, n/n), and volume percent of additives (0.05%, 0.10%, 0.15%, v/v), were investigated in BBD. The optimum experiment condition was that of reaction temperature (80 .deg. C), molar ratio of glycerol and ChCl (3 : 1, n/n), and volume percent of additive (0.10%, v/v). The mean chromatographic theoretical plate number of the caffeic acid this condition was 1567.5, and DESs as additives shorten the retention time and modify the chromatogram shape, proving DESs as additives for effective theoretical plate number and column efficiency in HPLC.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2004-01-01

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

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

    Science.gov (United States)

    Mamontov, Eugene; O'Neill, Hugh

    2014-06-01

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

  8. EVOLUTION OF THE ELECTROCHEMICAL CHARACTERISTICS DURING PITTING CORROSION OF PURE ALUMINUM IN SODIUM CHLORIDE SOLUTION

    Institute of Scientific and Technical Information of China (English)

    Z. Zhang; C. Cai; F.H. Cao; Z.N. Gao; J.Q. Zhang; C.N. Cao

    2005-01-01

    The corrosion behavior of pure aluminum in neutral 3.0% (mass fraction) sodium chloride (NaCl) solution has been studied using electrochemical impedance spectroscopy (ELS) measurement in conjunction with the scanning electron microscopy (SEM) technique. EIS information on the evolution of pitting corrosion over a period of 15 days has been obtained and analyzed with equivalent circuit technique. The results shown that, during the ensemble constant immersion time, two time constants involved, the high frequency one originated from the protective layer on the corroding surface while the low frequency one from the diffusion process or the corrosion reaction and so on. And there existed a period for oxide film to growth and thickening prior to the commencement of the attacking of chloride ions to the substrate. Meanwhile, good relationship between EIS and the material corrosion type/severity has been obtained, which has been interpreted according to the characteristics of corrosion process such as auto acceleration of pitting corrosion and the protection of local anodic reaction to the area around them.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-04-14

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

  10. Effect of Solution Annealing Temperature on Pitting Behavior of Duplex Stainless Steel 2204 in Chloride Solutions

    Institute of Scientific and Technical Information of China (English)

    Liang HE; Yan-jun GUO; Xia-yu WU; Yi-ming JIANG; Jin LI

    2016-01-01

    The effect of solution annealing temperature ranging from 950 to 1 200 ℃ on the microstructure and corro-sion performance of duplex stainless steel (DSS)2204 were investigated.The proportion of the ferrite phase in-creased while the austenite phase decreased and the ferrite stabilizing elements diluted in the ferrite phase with the in-crease of annealing temperature.The critical pitting temperature (CPT)of specimens annealed at 1 000 ℃ was higher than those annealed at 950 ℃,whereas further increasing the annealing temperature to 1 200 ℃ decreased the CPT. The pitting initiation sites were observed in the austenite phase,at the boundary of ferrite/austenite phase and inside the ferrite phase for specimens annealed at 950,1 000 ℃ and exceeding 1 100 ℃,respectively.The evolution trend of the CPT and the pit initiation site were analyzed by the pitting resistance equivalent number.

  11. Particle-induced x-ray emission: Instrumentation, calibration, and application to contact lens solutions and fulvic acid solutions

    Energy Technology Data Exchange (ETDEWEB)

    Jenson, D.D.

    1989-01-01

    An expression was derived describing the profile of the proton beam at the PIXE target position. The expression was used to predict the profile for several experimental configurations. The profile was experimentally measured. The PIXE system was calibrated using solutions and commercial foils. Experimental data was adjusted for all absorbers and interferences, and a quadratic relationship was determined relating calibration factor and atomic number for each series of X-ray transitions. Calibration factors were determined for all elements above aluminum, for both a pinhole filter and a 14-mil mylar filter. A group of contact lens solutions was analyzed using PIXE, ICP, and ISE. A digestion method was developed for removal. of chloride ion. Cluster analysis was used to classify the data. A commercial humic acid was separated into three fractions. The fulvic acid was characterized, and separations of metal-fulvic acid complexes from metal ions in solution were attempted using ultrafiltration.

  12. Corrosion behaviour of Fe-Mn-Si-Al austenitic steel in chloride solution

    Directory of Open Access Journals (Sweden)

    W. Krukiewicz

    2009-04-01

    Full Text Available Purpose: The aim of the paper is to investigate the corrosion behaviour of the new-developed high-manganese austenitic steel in 0.5n NaCl solution.Design/methodology/approach: The steel used for the investigation was thermomechanically rolled and solution heat-treated from a temperature of 850°C. Corrosion resistance of investigated steel was examined using weight and potentiodynamic methods. In the weight method, the specimens were immersed in the prepared solution for 24h. In the potentiodynamic method, anodic polarization curves with a rate of potential changes of 1 mV/s in the anodic direction were registered. After the current density being equal 1 mA/cm2 was achieved, the direction of polarization has been changed. Basing on the registered curves, the pitting potential, repassivation potential, polarization resistance and corrosion current were determined.Findings: It was found that the steel is characterized by a partially recrystallized austenitic microstructure with numerous annealing twins and slip bands. According to the results of potentiodynamic analyses it was found that the samples of examined steel show poor corrosion resistance in the NaCl solution. The observed corrosion pits are related to the chemical composition. It is connected with the high dissolution rate of Mn and Fe atoms in NaCl solution. Fractographic analyses of samples revealed corrosion products on their surface in a form of pits with diversified size.Research limitations/implications: To investigate in more detail the corrosion behaviour of high-manganese steel, the investigations should include steels with a wider Al concentration.Practical implications: The obtained results can be used for searching the appropriate way of improving the corrosion resistance of a modern group of high-manganese austenitic steels.Originality/value: The corrosion behaviour in chloride solution of a new-developed Fe-Mn-Si-Al steel was investigated.

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

    Indian Academy of Sciences (India)

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

    2010-06-01

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

  14. CORROSION MONITORING OF LY12 IN SODIUM CHLORIDE SOLUTION WITH ELECTROCHEMICAL NOISE TECHNIQUE

    Institute of Scientific and Technical Information of China (English)

    J.Q. Zhang; Z. Zhang; J.M. Wang; H.B. Shao; C.N. Cao

    2001-01-01

    Spontaneous electrochemical noise (EN) can be a rich source of information concerning the processes simultaneously occurring on a corroding interface. But the noise signal is often difficult to be analyzed due to the complicated nature of the specific systems being investigated. In this paper, the potential noise fluctuations during the free corrosion of commercial aluminum alloy LY12 in sodium chloride solution was recorded and analyzed with different techniques. The typical results showed that the fractal dimension (D,n) obtained from spectral power density (SPD) is mainly directly proportional to the intensity of pitting corrosion and to the value of pitting parameter (SE) derived from dimensional analysis, while the fractal dimension (DE) obtained from EIS is mainly related to the uniform corrosion.

  15. Analysis of corrosion behavior of LY12 in sodium chloride solution with wavelet transform technique

    Institute of Scientific and Technical Information of China (English)

    张昭; 曹发和; 程英亮; 张鉴清; 王建明; 曹楚南

    2002-01-01

    Wavelet transforms(WT) are proposed as an alternative tool to overcome the limitations of fast Fourier transforms(FFT) in the analysis of electrochemical noise(EN) data. The most relevant feature of this method of analysis is its capability of decomposing electrochemical noise records into different sets of wavelet coefficients(distinct type of events), which contains information about the time scale characteristic of the associated corrosion event. In this context, the potential noise fluctuations during the free corrosion of commercial aluminum alloy LY12 in sodium chloride solution was recorded and analyzed with wavelet transform technique. The typical results show that the EN signal is composed of distinct type of events, which can be classified according to their scales, i.e. their time constants. Meanwhile, the energy distribution plot(EDP) can be used as "fingerprints" of EN signals and can be very useful for analyzing EN data in the future.

  16. ELECTROCHEMICAL NOISE ANALYSIS OF PURE ALUMINUM IN SODIUM CHLORIDE SOLUTION WITH WAVELET TRANSFORM TECHNIQUE

    Institute of Scientific and Technical Information of China (English)

    Z. Zhang; Q.D. Zhong; J.Q. Zhang; Y.L. Cheng; F.H. Cao; J.M. Wang; C.N. Cao

    2002-01-01

    Wavelet transforms (WT) are proposed as an alternative tool to overcome the limita-tions of Fourier transforms (FFT) in the analysis of electrochemical noise (EN) data.The most relevant feature of this method of analysis is its capability of decomposingelectrochemical noise records into different sets of wavelet coefficients, which containinformation about the time scale characteristic of the associated corrosion event. Inthis context, the potential noise fluctuations during the free corrosion of pure alu-minum in sodium chloride solution was recorded and analyzed with wavelet transformtechnique. The typical results showed that the EN signal is composed of distinct typeof events, which can be classified according to their scales, i.e. their time constants.Meanwhile, the energy distribution plot (EDP) can be used as "fingerprints" of ENsignals and can be very useful for analyzing EN data in the future.

  17. Corrosion Fatigue of Austenitic Stainless Steel in Different Hot Chloride Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Visser, A.; Mori, G.; Panzenboeck, M. [Montanuniversitaet Leoben, Leoben (Austria); Pippan, R. [Erich Schmid Institute of Materials Science, Austrian Academy of Science, Leoben (Austria)

    2015-08-15

    Austenitic stainless steel was investigated under cyclic loading in electrolytes with different chloride contents and pH and at different temperatures. The testing solutions were 13.2 % NaCl (80,000 ppm Cl-) at 80 °C and 43 % CaCl{sub 2} (275,000 ppm Cl-) at 120 °C. In addition to S-N curves in inert and corrosive media, the fracture surfaces were investigated with a scanning electron microscope (SEM) to analyse the type of attack. The experimental results showed that a sharp decrease in corrosion fatigue properties can be correlated with the occurrence of stress corrosion cracking. The correlation of occurring types of damage in different corrosion systems is described.

  18. Novel 5-substituted benzyloxy-2-arylbenzofuran-3-carboxylic acids as calcium activated chloride channel inhibitors

    OpenAIRE

    Kumar, Satish; Namkung, Wan; A S Verkman; Sharma, Pawan K

    2012-01-01

    Transmembrane protein 16A (TMEM16A) channels are recently discovered membrane proteins that functions as a calcium activated chloride channel (CaCC). CaCCs are major regulators of various physiological processes, such as sensory transduction, epithelial secretion, smooth muscle contraction and oocyte fertilization. Thirty novel 5-substituted benzyloxy-2-arylbenzofuran-3-carboxylic acids (B01–B30) were synthesized and evaluated for their TMEM16A inhibitory activity by using short circuit curre...

  19. Kinetics of Sawdust Hydrolysis with Dilute Hydrochloric Acid and Ferrous Chloride

    Institute of Scientific and Technical Information of China (English)

    袁传敏; 颜涌捷; 任铮伟; 李庭琛; 曹建勤

    2004-01-01

    With dilute hydrochloric acid as catalyst and promoted by ferrous chloride, hydrolysis of waste sawdust to produce monosaccharides was conducted by using an one-step method in a batch-wise operation reactor. Based on the model of first order consecutive irreversible reactions, the kinetics equation incorporating the term of catalyst concentration was obtained that is suitable for describing the hydrolysis of sawdust. Activation energies were calculated for hydrolysis of sawdust and decomposition of monosaccharides.

  20. Sorption recovery of platinum (II, IV in presence of copper (II and zinc (II from chloride solutions

    Directory of Open Access Journals (Sweden)

    Kononova Olga N.

    2015-01-01

    Full Text Available The sorption preconcentration of platinum (II, IV ions was investigated in presence of accompanying copper (II and zinc (II ions from chloride solutions on the new ion exchangers CYBBER (Russia, previously unexplored. The initial concentrations of platinum and accompanying ions were 0.25 mmol L-1 and 2.0 mmol L-1, respectively, and the acidity of medium was 0.001 - 4.0 mol L-1. It was shown that the resins investigated - strong and weak basic anion exchangers as well as chelate ion exchangers - possess good sorption and kinetic properties. The simultaneous sorption of investigated ions results in the complete recovery of platinum, while the non-ferrous metal ions are sorbed at less than 20%. Followed by the selective elution of platinum by thiourea (80 g L-1 solution in 0.3 M H2SO4, the quantitative isolation of platinum was achieved (more than 90%. Therefore, the studied ion exchangers can be recommended for recovery and separation of Pt(II,IV, Cu(II and Zn(II ions.

  1. Effects of thermal oxidation and subsequent pickling on pitting geometry of austenitic stainless steels in chloride solutions

    Energy Technology Data Exchange (ETDEWEB)

    Alar, Vesna; Esih, Ivan; Budic, Ivan; Brod, Slavonski [Zagreb Univ. (Croatia). Dept. of Materials

    2011-07-01

    Harmful effects of thermal oxides formed on austenitic stainless steels (SS) like AISI 304 and 316L by heating in air or other oxidizing gases on their pitting liability in chloride solutions have been studied by pursuing geometric characteristics of corrosion process (pits density, their depths, and mouth areas, ie. penetrating and superficial detrimental consequences etc.). The possibility of preventing the decay of thermally oxidized austenitic SS by chemical removal (pickling) of oxides before exposure to chloride solutions was successfully applied on simple specimens but serious difficulties arose on welded parts and on parts exposed to other temperature gradients during manufacture or in exploitation. (orig.)

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

    Science.gov (United States)

    Walsh, Lois Harper

    1989-10-01

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

  3. A study of the electrochemical behavior in tungsten and caustic solutions and platinum/iridium in chloride solutions, informal report

    Energy Technology Data Exchange (ETDEWEB)

    Vitus, C.M.; Isaacs, H.S. [Brookhaven National Lab., Upton, NY (United States); Schroeder, V. [Univ. of California, Berkeley, CA (United States). College of Engineering

    1994-11-22

    Platinum/iridium and tungsten wires were electronically etched in chloride and caustic solution, respectively, to produce tips with high aspect ratio. A direct relationship between the meniscus and the aspect ratio of etched tips was established. Scanning electron micrographs indicated that higher aspect ratios were obtained by changing the geometry of the meniscus during the etch either by an increase in the applied a.c. voltage or with the addition of a nonpolar layer above the electrolytic solution during the etching process. Above the breakdown voltage, two possible mechanisms appeared to control the etching process by expediting chemical dissolution: cavitation and sparking. Cavitation caused erosion due to the force of evolved gases against the electrode and sparking attacked the surface by vaporizing the metal. Sparking commenced on both wires near 24V. This voltage corresponded to a minimum in the plot of total etch time versus voltage. From light emission studies, sparking on Pt/Ir was associated with the ionization of Pt, Ir, Ca, and Cl. A compositional analysis of insoluble black particles produced during a.c. and d.c. etching of Pt/Ir revealed Pt and Ir as the major constituents of the product. The sparking process was shown to have a potential use in micromachining.

  4. Phytic Acid and Sodium Chloride Show Marked Synergistic Bactericidal Effects against Nonadapted and Acid-Adapted Escherichia coli O157:H7 Strains.

    Science.gov (United States)

    Kim, Nam Hee; Rhee, Min Suk

    2016-02-01

    The synergistic antimicrobial effects of phytic acid (PA), a natural extract from rice bran, plus sodium chloride against Escherichia coli O157:H7 were examined. Exposure to NaCl alone at concentrations up to 36% (wt/wt) for 5 min did not reduce bacterial populations. The bactericidal effects of PA alone were much greater than those of other organic acids (acetic, citric, lactic, and malic acids) under the same experimental conditions (P 7-log CFU/ml reduction). Flow cytometry confirmed that PA disrupted the cell membrane to a greater extent than did other organic acids, although the cells remained viable. The combination of PA and NaCl induced complete disintegration of the cell membrane. By comparison, none of the other organic acids acted synergistically with NaCl, and neither did NaCl-HCl solutions at the same pH values as the test solutions of PA plus NaCl. These results suggest that PA has great potential as an effective bacterial membrane-permeabilizing agent, and we show that the combination is a promising alternative to conventional chemical disinfectants. These findings provide new insight into the utility of natural compounds as novel antimicrobial agents and increase our understanding of the mechanisms underlying the antibacterial activity of PA. PMID:26637600

  5. Electrochemical corrosion behavior of Cu-40Ni-20Cr alloys with different grain sizes in solutions containing chloride ions

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The electrochemical corrosion behavior of the two Cu-40Ni-20Cr alloys prepared by conventional casting(CA) and mechanical alloying(MA) with the different grain sizes was studied by using open-circuit potential(OCP), potentiodynamic polarization and electrochemical impedance spectroscopy(EIS) methods in solutions containing chloride ions. The results show that the free corrosion potentials of the two alloys move towards negative values, corrosion currents increase and therefore corrosion rates become faster with the increase of chloride ion concentrations. EIS plots of CACu-40Ni-20Cr alloy are composed of single capacitive loop, while EIS plots of MACu-40Ni-20Cr alloy are composed of double capacitive loops in solution containing lower chloride ion concentrations. EIS plots of the two alloys have Warburg impedance with the increase of chloride ion concentrations.Corrosion rates of MACu-40Ni-20Cr alloy become faster than those of CACu-40Ni-20Cr alloy obviously in solutions containing the same chloride ion concentrations because MACu-40Ni-20Cr alloy is able to produce large concentrations of grain boundaries in the course of reduction in grain size by mechanical alloying.

  6. Participation of GABAA Chloride Channels in the Anxiolytic-Like Effects of a Fatty Acid Mixture

    Directory of Open Access Journals (Sweden)

    Juan Francisco Rodríguez-Landa

    2013-01-01

    Full Text Available Human amniotic fluid and a mixture of eight fatty acids (FAT-M identified in this maternal fluid (C12:0, lauric acid, 0.9 μg%; C14:0, myristic acid, 6.9 μg%; C16:0, palmitic acid, 35.3 μg%; C16:1, palmitoleic acid, 16.4 μg%; C18:0, stearic acid, 8.5 μg%; C18:1cis, oleic acid, 18.4 μg%; C18:1trans, elaidic acid, 3.5 μg%; C18:2, linoleic acid, 10.1 μg% produce anxiolytic-like effects that are comparable to diazepam in Wistar rats, suggesting the involvement of γ-aminobutyric acid-A (GABAA receptors, a possibility not yet explored. Wistar rats were subjected to the defensive burying test, elevated plus maze, and open field test. In different groups, three GABAA receptor antagonists were administered 30 min before FAT-M administration, including the competitive GABA binding antagonist bicuculline (1 mg/kg, GABAA benzodiazepine antagonist flumazenil (5 mg/kg, and noncompetitive GABAA chloride channel antagonist picrotoxin (1 mg/kg. The FAT-M exerted anxiolytic-like effects in the defensive burying test and elevated plus maze, without affecting locomotor activity in the open field test. The GABAA antagonists alone did not produce significant changes in the behavioral tests. Picrotoxin but not bicuculline or flumazenil blocked the anxiolytic-like effect of the FAT-M. Based on the specific blocking action of picrotoxin on the effects of the FAT-M, we conclude that the FAT-M exerted its anxiolytic-like effects through GABAA receptor chloride channels.

  7. Synthesis of N-Acylated Amino Acid Surfactant from L-Proline and Palmitoyl Chloride

    International Nuclear Information System (INIS)

    A biodegradable, less toxic and environmentally friendly N-acylated amino acid surfactant was prepared from the amino acid L-proline and palmitoyl chloride through acylation reaction using the Schotten-Baumann reaction condition. The reaction result was a white flake form and the percentage of the crude yield was 72 % with melting point in range of 52 - 58 degree Celsius. Functional group of amide which was detected using Fourier Transform Infrared method showed the presence of N-palmitoyl proline. The purity analysis using High Performance Liquid Chromatography and Thin Layer Chromatography showed the result was a mixture compound. (author)

  8. Sulfate, chloride and fluoride retention in Andosols exposed to volcanic acid emissions.

    Science.gov (United States)

    Delmelle, Pierre; Delfosse, Thomas; Delvaux, Bruno

    2003-01-01

    The continuous emissions of SO(2), HCl and HF by Masaya volcano, Nicaragua, represent a substantial source of atmospheric S-, Cl- and F-containing acid inputs for local ecosystems. We report on the effects of such acid depositions on the sulfate, chloride and fluoride contents in soils (0-40 cm) from two distinct transects located downwind from the volcano. The first transect corresponds to relatively undifferentiated Vitric Andosols, and the second transect to more weathered Eutric Andosols. These soils are exposed to various rates of volcanogenic acid addition, with the Vitric sites being generally more affected. Prolonged acid inputs have led to a general pH decrease and reduced exchangeable base cation concentrations in the Andosols. The concentrations of 0.5 M NH(4)F- and 0.016 M KH(2)PO(4)-extractable sulfate (NH(4)F-S and KH(2)PO(4)-S, respectively) indicate that volcanic S addition has increased the inorganic sulfate content of the Vitric and Eutric soils at all depths. In this process, the rate of sulfate accumulation is also dependent on soil allophane contents. For all soils, NH(4)F extracted systematically more (up to 40 times) sulfate than KH(2)PO(4). This difference suggests sulfate incorporation into an aluminum hydroxy sulfate phase, whose contribution to total inorganic sulfate in the Vitric and Eutric Andosols is estimated from approximately 34 to 95% and approximately 65 to 98%, respectively. The distribution of KH(2)PO(4)-extractable chloride in the Vitric and Eutric Andosols exposed to volcanic Cl inputs reveals that added chloride readily migrates through the soil profiles. In contrast, reaction of fluoride with Al and Fe oxyhydroxides and allophanes is an important sink mechanism in the Masaya Andosols exposed to airborne volcanic F. Fluoride dominates the anion distribution in all soil horizons, although F is the least concentrated element in the volcanic emissions and depositions. The soil anion distribution reflects preferential retention

  9. Formation of linear polyenes in poly(vinyl alcohol) films catalyzed by phosphotungstic acid, aluminum chloride, and hydrochloric acid

    Science.gov (United States)

    Tretinnikov, O. N.; Sushko, N. I.; Malyi, A. B.

    2016-07-01

    Formation of linear polyenes-(CH=CH)n-via acid-catalyzed thermal dehydration of polyvinyl alcohol in 9- to 40-µm-thick films of this polymer containing hydrochloric acid, aluminum chloride, and phosphotungstic acid as dehydration catalysts was studied by electronic absorption spectroscopy. The concentration of long-chain ( n ≥ 8) polyenes in films containing phosphotungstic acid is found to monotonically increase with the duration of thermal treatment of films, although the kinetics of this process is independent of film thickness. In films containing hydrochloric acid and aluminum chloride, the formation rate of polyenes with n ≥ 8 rapidly drops as film thickness decreases and the annealing time increases. As a result, at a film thickness of less than 10-12 µm, long-chain polyenes are not formed at all in these films no matter how long thermal duration is. The reason for this behavior is that hydrochloric acid catalyzing polymer dehydration in these films evaporates from the films during thermal treatment, the evaporation rate inversely depending on film thickness.

  10. Analysis of antibacterial efficacy of plasma-treated sodium chloride solutions

    Science.gov (United States)

    Hänsch, Mareike A. C.; Mann, Miriam; Weltmann, Klaus-Dieter; von Woedtke, Thomas

    2015-11-01

    In this study, the change of chemical composition of sodium chloride solutions (NaCl, 0.85%) induced by non-thermal atmospheric pressure plasma (APP) treatment and subsequent effects on bacteria (Escherichia coli) are investigated. Besides acidification caused by APP, hydrogen peroxide (H2O2), nitrite (\\text{NO}2- ), and nitrate (\\text{NO}3- ) are generated as stable end-products of various chemical reactions in APP-treated liquids. Inactivation kinetics and reduction factors were recorded for E. coli (K12). Almost identical antimicrobial effects were observed with both direct APP exposure to bacteria suspension and exposure of APP-treated liquids to bacteria (indirect treatment). Consequently, main bactericidal effects are caused by chemical reactions which are mediated via the liquid phase. Moreover, APP-treated liquids have shown long-term activity (30 min) that possibly correlates with the ratio of \\text{NO}2- /H2O2. Therefore, \\text{NO}2- and H2O2 are identified as key agents for antimicrobial short- and long-term effects, respectively. The antimicrobial stability observed is strongly dependent on the used treatment regime and correlates additionally with the altered chemical composition of APP-treated liquids. Besides these effects, it was also shown that bacteria do not acquire resistance to such APP-treated solutions.

  11. Metal lanolin fatty acid as novel thermal stabilizers for rigid poly(vinyl chloride)

    Institute of Scientific and Technical Information of China (English)

    GUO Yong; ZHENG Yuying; QIU Shangchang; ZENG Anran; LI Baoming

    2011-01-01

    The synergistic stabilization effect of different metal lanolin fatty acids as natural-based thermal stabilizers for poly(vinyl chloride)(PVC) including calcium lanolin fatty acid (Calan2), zinc lanolin fatty acid (Znlan2) and lanthanum lanolin fatty acid (Lalan3) were studied through Congo red testing, color measurements, FTIR analyses and thermal behavior in this paper. The results showed that Lalan3/Calan2/Znlan2 stabilizers exhibited more excellent thermal stabilization efficiency to PVC than Calan2/Znlan2 thermal stabilizers, and the optimal mass ratio of Lalan3/Calan2/Znlan2 was 8:9:3. At last, the effect of degradation mechanism on PVC and synergistic stabilization was also investigated by FTIR analyses and thermal behavior.

  12. Alkaline earth cation extraction from acid solution

    Science.gov (United States)

    Dietz, Mark; Horwitz, E. Philip

    2003-01-01

    An extractant medium for extracting alkaline earth cations from an aqueous acidic sample solution is described as are a method and apparatus for using the same. The separation medium is free of diluent, free-flowing and particulate, and comprises a Crown ether that is a 4,4'(5')[C.sub.4 -C.sub.8 -alkylcyclohexano]18-Crown-6 dispersed on an inert substrate material.

  13. Wet oxidation of salicylic acid solutions.

    Science.gov (United States)

    Collado, Sergio; Garrido, Laura; Laca, Adriana; Diaz, Mario

    2010-11-15

    Salicylic acid is a frequent pollutant in several industrial wastewaters. Uncatalyzed wet air oxidation, which is a promising technique for the treatment of phenolic effluents, has not been analyzed yet for the removal of salicylic acid. The effect of different conditions of pH (1.3-12.3), pressure (1.0-4.1 MPa), temperature (413-443 K), and initial concentrations (1.45-14.50 mM) on the wet oxidation of salicylate/salicylic acid solutions have here been investigated. The pH value of the reaction media was found to be a key parameter for the rate of the oxidation process with an optimum at pH 3.1, when the concentrations of salicylic acid and salicylate were similar. The oxidation reaction followed pseudofirst-order kinetics with respect to salicylic acid and 0.82 order with respect to dissolved oxygen. Additionally, the evolution of the color during the wet oxidation was analyzed and discussed in relation with the formation of intermediate compounds. Then, a reaction pathway for the noncatalytic wet oxidation of the salicylic acid was proposed.

  14. The central role of chloride in the metabolic acid-base changes in canine parvoviral enteritis.

    Science.gov (United States)

    Burchell, Richard K; Schoeman, Johan P; Leisewitz, Andrew L

    2014-04-01

    The acid-base disturbances in canine parvoviral (CPV) enteritis are not well described. In addition, the mechanisms causing these perturbations have not been fully elucidated. The purpose of the present study was to assess acid-base changes in puppies suffering from CPV enteritis, using a modified strong ion model (SIM). The hypothesis of the study was that severe acid-base disturbances would be present and that the SIM would provide insights into pathological mechanisms, which have not been fully appreciated by the Henderson-Hasselbalch model. The study analysed retrospective data, obtained from 42 puppies with confirmed CPV enteritis and 10 healthy control dogs. The CPV-enteritis group had been allocated a clinical score, to allow classification of the data according to clinical severity. The effects of changes in free water, chloride, l-lactate, albumin and phosphate were calculated, using a modification of the base excess algorithm. When the data were summated for each patient, and correlated to each individual component, the most important contributor to the metabolic acid-base changes, according to the SIM, was chloride (Penteritis are multifactorial and complex, with the SIM providing information in terms of the origin of these changes.

  15. Lewis Acid Catalysis of the Diels–Alder Reaction Using Niobium and Tantalum Chlorides in the Presence of Coordinating Ligands

    Directory of Open Access Journals (Sweden)

    Kevin Gillespie

    2000-08-01

    Full Text Available The Jacobsen and pybox type ligands effect chiral induction in the presence of niobium(V chloride and tantalum(V chloride in the Lewis acid catalysed Diels–Alder reaction.

  16. Acidities of Water and Methanol in Aqueous Solution and DMSO

    Science.gov (United States)

    Gao, Daqing

    2009-01-01

    The relative acidities of water and methanol have been a nagging issue. In gas phase, methanol is more acidic than water by 36.0 kJ/mol; however, in aqueous solution, the acidities of methanol and water are almost identical. The acidity of an acid in solution is determined by both the intrinsic gas-phase ionization Gibbs energy and the solvent…

  17. Functional modifications of acid-sensing ion channels by ligand-gated chloride channels.

    Directory of Open Access Journals (Sweden)

    Xuanmao Chen

    Full Text Available Together, acid-sensing ion channels (ASICs and epithelial sodium channels (ENaC constitute the majority of voltage-independent sodium channels in mammals. ENaC is regulated by a chloride channel, the cystic fibrosis transmembrane conductance regulator (CFTR. Here we show that ASICs were reversibly inhibited by activation of GABA(A receptors in murine hippocampal neurons. This inhibition of ASICs required opening of the chloride channels but occurred with both outward and inward GABA(A receptor-mediated currents. Moreover, activation of the GABA(A receptors modified the pharmacological features and kinetic properties of the ASIC currents, including the time course of activation, desensitization and deactivation. Modification of ASICs by open GABA(A receptors was also observed in both nucleated patches and outside-out patches excised from hippocampal neurons. Interestingly, ASICs and GABA(A receptors interacted to regulate synaptic plasticity in CA1 hippocampal slices. The activation of glycine receptors, which are similar to GABA(A receptors, also modified ASICs in spinal neurons. We conclude that GABA(A receptors and glycine receptors modify ASICs in neurons through mechanisms that require the opening of chloride channels.

  18. Pitting corrosion of Al2024-T3 in sodium chloride solution

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Pitting corrosion behavior of Al2024-T3 in sodium chloride solution was investigated by using potentiodynamic scanning (PDS) measurements and electrochemical impedance spectroscopy (EIS) technique. When pitting corrosion of the alloy occurs, there exists a passive region in the anodic branch of PDS polarization curve, which is enlarged with the increasing of immersion time due to the competition of the halide ions with OH- ions to adsorb on the oxide film to form the corrosion products film and the increase of pitting corrosion area. Two capacitive semicircles were observed in complex plane plot. For more extensive pitting and general corrosion of Al2024-T3, the passive region in PDS disappeared, while another depressed semicircle was observed in Nyquist plot because of the formation of corrosion products film. On the other hand, the low frequency inductive loop, which had often been regarded as a manifestation of pitting or formation and precipitation of a salt film, was not observed, which indicates that the low frequency inductive loop can not be the characteristic of pitting corrosion or the formation of salt film. The results also show that higher reactant CPE exponent values will correspond to more extensive transformation of a metal surface by very localized corrosion, while general corrosion can result in a smaller CPE exponent value.

  19. Formation of black nickel in leaching solution containing ammonia and chloride

    Institute of Scientific and Technical Information of China (English)

    ZHENG Guo-qu; ZHENG Li-feng; CAO Hua-zhen

    2005-01-01

    The black nickel formation process in leaching solution containing ammonia and chloride was investigated in terms of cyclic voltammetric and galvanostatic reduction techniques.The structure of black nickel was examined by means of X-ray diffraction technique.The results show that in the scanning region,two oxidization current peaks are observed during the positive sweep,one of which is attributed to a valence state transformation of Ni(OH)2 to high valence nickel compound(black nickel),and the other is caused by nitrogen evolution.During the formation process of black nickel,γ-NiOOH probably tends to self-discharge with water to form α-Ni(OH)2.As a result,it is observed that Ipa/Ipc(Ipa-anodic peak current;Ipc-cathodic peak current) maintains at a constant with the scanning rate increasing.Two reduction current peaks in cyclic voltammogram and two potential plateaus in galvanostatic reduction curve for black nickel are ascribed to the reduction of various oxidization states of nickel oxide.The potential plateaus at about 0.75 V reach the maximum in galvanostatic reduction curves.Black nickel presents amorphous structure.

  20. The Influence of Calcium Chloride Salt Solution on the Transport Properties of Cementitious Materials

    Directory of Open Access Journals (Sweden)

    Yaghoob Farnam

    2015-01-01

    Full Text Available The chemical interaction between calcium chloride (CaCl2 and cementitious binder may alter the transport properties of concrete which are important in predicting the service life of infrastructure elements. This paper presents a series of fluid and gas transport measurements made on cementitious mortars before and after exposure to various solutions with concentrations ranging from 0% to 29.8% CaCl2 by mass. Fluid absorption, oxygen diffusivity, and oxygen permeability were measured on mortar samples prepared using Type I and Type V cements. Three primary factors influence the transport properties of mortar exposed to CaCl2: (1 changes in the degree of saturation, (2 calcium hydroxide leaching, and (3 formation of chemical reaction products (i.e., Friedel’s salt, Kuzel’s salt, and calcium oxychloride. It is shown that an increase in the degree of saturation decreases oxygen permeability. At lower concentrations (~12%, the formation of chemical reaction products (mainly calcium oxychloride is a dominant factor decreasing the fluid and gas transport in concrete.

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

    Science.gov (United States)

    Zhang, Zhigang; Duan, Zhenhao

    2004-02-01

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

  2. Electrochemical noise characteristics in corrosion process of AZ91D magnesium alloy in neutral chloride solution

    Institute of Scientific and Technical Information of China (English)

    ZHANG Li-jun; ZHU Xu-bei; ZHANG Zhao; ZHANG Jian-qing

    2009-01-01

    The corrosion process of AZ91D magnesium alloy in neutral 1% (mass fraction) sodium chloride aqueous solution was investigated by electrochemical noise(EN), SEM and EDX. Fractal theory was primarily used to depict the corrosion process of the alloy. The fast wavelet transform(FWT), as well as the fast Fourier transform(FFT), was employed to analyze the EN data. The results show that the overall corrosion process can be described by three stages. The first stage corresponds to the pit nucleation and growth; the second stage involves the growth of a passive oxide layer; and the third stage involves reactivation. With increasing immersion time, fractal dimension increases fast initially, fluctuates in the medium and increases again at last. Pitting corrosion and fractal dimension increase due to the initiation and formation of pits in the initial and the end of immersion, while depresses due to the passivation in the medium period. The results of SEM and EDX support the above conclusions.

  3. Chloride Anions Regulate Kinetics but Not Voltage-Sensor Qmax of the Solute Carrier SLC26a5.

    Science.gov (United States)

    Santos-Sacchi, Joseph; Song, Lei

    2016-06-01

    In general, SLC26 solute carriers serve to transport a variety of anions across biological membranes. However, prestin (SLC26a5) has evolved, now serving as a motor protein in outer hair cells (OHCs) of the mammalian inner ear and is required for cochlear amplification, a mechanical feedback mechanism to boost auditory performance. The mechanical activity of the OHC imparted by prestin is driven by voltage and controlled by anions, chiefly intracellular chloride. Current opinion is that chloride anions control the Boltzmann characteristics of the voltage sensor responsible for prestin activity, including Qmax, the total sensor charge moved within the membrane, and Vh, a measure of prestin's operating voltage range. Here, we show that standard narrow-band, high-frequency admittance measures of nonlinear capacitance (NLC), an alternate representation of the sensor's charge-voltage (Q-V) relationship, is inadequate for assessment of Qmax, an estimate of the sum of unitary charges contributed by all voltage sensors within the membrane. Prestin's slow transition rates and chloride-binding kinetics adversely influence these estimates, contributing to the prevalent concept that intracellular chloride level controls the quantity of sensor charge moved. By monitoring charge movement across frequency, using measures of multifrequency admittance, expanded displacement current integration, and OHC electromotility, we find that chloride influences prestin kinetics, thereby controlling charge magnitude at any particular frequency of interrogation. Importantly, however, this chloride dependence vanishes as frequency decreases, with Qmax asymptoting at a level irrespective of the chloride level. These data indicate that prestin activity is significantly low-pass in the frequency domain, with important implications for cochlear amplification. We also note that the occurrence of voltage-dependent charge movements in other SLC26 family members may be hidden by inadequate

  4. Effects of concentration of sodium chloride solution on the pitting corrosion behavior of AISI 304L austenitic stainless steel

    Directory of Open Access Journals (Sweden)

    Asaduzzaman M.D.

    2011-01-01

    Full Text Available The pitting corrosion behavior of the austenitic stainless steel in aqueous chloride solution was investigated using electrochemical technique. Corrosion potential (Ecorr measurement, potentiodynamic experiments, potential-hold experiments in the passive range, and microscopic examination were used for the evaluation of corrosion characteristics. The experimental parameters were chloride ion concentration, immersion time and anodic-hold potential. Ecorr measurements along with microscopic examinations suggest that in or above 3.5 % NaCl at pH 2 pitting took place on the surface in absence of applied potential after 6 hour immersion. The potentiodynamic experiment reveals that Ecorr and pitting potential (Epit decreased and current density in the passive region increased with the increase of chloride ion concentrations. A linear relationship between Epit and chloride ion concentrations was found in this investigation. The analysis of the results suggests that six chloride ions are involved for the dissolution of iron ion in the pitting corrosion process of austenitic stainless steel.

  5. Calcium Chloride in Neonatal Parenteral Nutrition Solutions with and without Added Cysteine: Compatibility Studies Using Laser and Micro-Flow Imaging Methodology.

    Directory of Open Access Journals (Sweden)

    Robert K Huston

    Full Text Available Previous studies of compatibility of calcium chloride (CaCl2 and phosphates have not included particle counts in the range specified by the United States Pharmacopeia. Micro-flow imaging techniques have been shown to be comparable to light obscuration when determining particle count and size in pharmaceutical solutions.The purpose of this study was to do compatibility testing for parenteral nutrition (PN solutions containing CaCl2 using dynamic light scattering and micro-flow imaging techniques.Solutions containing TrophAmine (Braun Medical Inc, Irvine, CA, CaCl2, and sodium phosphate (NaPhos were compounded with and without cysteine. All solutions contained standard additives to neonatal PN solutions including dextrose, trace metals, and electrolytes. Control solutions contained no calcium or phosphate. Solutions were analyzed for particle size and particle count. Means of Z-average particle size and particle counts of controls were determined. Study solutions were compared to controls and United States Pharmacopeia (USP Chapter 788 guidelines. The maximum amount of Phos that was compatible in solutions that contained at least 10 mmol/L of Ca in 2.5% amino acids (AA was determined. Compatibility of these solutions was verified by performing analyses of 5 repeats of these solutions. Microscopic analyses of the repeats were also performed.Amounts of CaCl2 and NaPhos that were compatible in solutions containing 1.5%, 2%, 2.5%, and 3% AA were determined. The maximum amount of NaPhos that could be added to TrophAmine solutions of > = 2.5% AA containing at least 10 mmol/L of CaCl2 was 7.5 mmol/L. Adding 50 mg/dL of cysteine increased the amount of NaPhos that could be added to solutions containing 10 mmol/L of CaCl2 to 10 mmol/L.Calcium chloride can be added to neonatal PN solutions containing NaPhos in concentrations that can potentially provide an intravenous intake of adequate amounts of calcium and phosphorus.

  6. Uranyl fluoride luminescence in acidic aqueous solutions

    International Nuclear Information System (INIS)

    Luminescence emission spectra and decay rates are reported for uranyl species in acidic aqueous solutions containing HF or added NaF. The longest luminescence lifetime, 0.269 ± 0.006 ms, was observed from uranyl in 1 M HF + 1 M HClO4 at 296 K and decreased with increasing temperature. Based on a luminescence dynamics model that assumes equilibrium among electronically excited uranyl fluoride species and free fluoride ion, this long lived uranyl luminescence in aqueous solution is attributed primarily to UO2F2. Studies on the effect of added LiNO3 or Na2WO4·2H2O showed relatively weak quenching of uranyl fluoride luminescence which suggests that high sensitivity determination of the UF6 content of WF6 gas should be feasible via uranyl luminescence analysis of hydrolyzed gas samples of impure WF6

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

    International Nuclear Information System (INIS)

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

  8. Process for the extraction of strontium from acidic solutions

    Energy Technology Data Exchange (ETDEWEB)

    Horwitz, E.P.; Dietz, M.L.

    1993-01-01

    The invention is a process for selectively extracting strontium values from aqueous nitric acid waste solutions containing these and other fission product values. The extractant solution is a macrocyclic polyether in an aliphatic hydrocarbon diluent containing a phase modifier. The process will selectively extract strontium values from nitric acid solutions which are up to 6 molar in nitric acid.

  9. Involvements of chloride ion in decolorization of Acid Orange 7 by activated peroxydisulfate or peroxymonosulfate oxidation

    Institute of Scientific and Technical Information of China (English)

    Ping Wang; Shiying Yang; Liang Shan; Rui Niu; Xueting Shao

    2011-01-01

    The effects of chloride anion (C1-) (up to 1.0 mol/L) on the decolorization of a model compound,azo dye Acid Orange 7 (AO7),by sulfate radical (SO4-*) based-peroxydisulfate (PS) or peroxymonosulfate (PMS) oxidation under various activated conditions (UV254 nm/PS,Thermal (70℃/PS,UV254 nm/PMS,Co2+/PMS) were investigated.Methanol and NH4+ were used as quenching reagents to determine the contributions of active chlorine species (dichloride radical (Cl2-*) and hypochlorous acid (HClO)).The results indicated that the effects of Cl- on the reaction mechanism were different under various activated conditions.For UV/PS and Thermal/PS,the inhibition tendency became more clear as the Cl-concentration increased,probably due to the reaction between Cl- and SO4-* and the generation of Cl2-* or HClO.For UV/PMS,Cl- did not exhibit inhibition when the concentration was below 0.1 mol/L.As Cl-concentration reached to 1.0 mol/L,the decolorization rate of AO7 was,however,accelerated,possibly because PMS directly reacts with C1- to form HC1O.For Co2+/PMS,Cl- exhibited a significant inhibiting effect even at low concentration (≤ 0.01 mol/L).When Cl- concentration exceeded 0.1 mol/L,the activation of PMS by Co2+ was almost completely inhibited.Under this condition,HClO maybe played a major role in decolorization of AO7.The results implicated that chloride ion is an important factor in SO4-*-based degradation of organic contamination in chloride-containing water.

  10. Chloride Ion Transmission Model under the Drying-wetting Cycles and Its Solution

    Institute of Scientific and Technical Information of China (English)

    HUANG Ying; WEI Jun; DONG Rongzhen; ZENG Hua

    2014-01-01

    The chloride ion transmission model considering diffusion and convection was established respectively for different zones in concrete by analyzing chloride ion transmission mechanism under the drying-wetting cycles. The finite difference method was adopted to solve the model. The equation of chloride ion transmission model in the convection and diffusion zone of concrete was discreted by the group explicit scheme with right single point (GER method) and the equation in diffusion zone was discreted by FTCS difference scheme. According to relative humidity characteristics in concrete under drying-wetting cycles, the seepage velocity equation was formulated based on Kelvin Equation and Darcy’s Law. The time-variant equations of chloride ion concentration of concrete surface and the boundary surface of the convection and diffusion zone were established. Based on the software MATLAB the numerical calculation was carried out by using the model and basic material parameters from the experiments. The calculation of chloride ion concentration distribution in concrete is in good agreement with the drying-wetting cycles experiments. It can be shown that the chloride ion transmission model and the seepage velocity equation are reasonable and practical. Studies have shown that the chloride ion transmission in concrete considering convection and diffusion under the drying-wetting cycles is the better correlation with the actual situation than that only considering the diffusion.

  11. Passivation of duplex stainless steel in solutions simulating chloride-contaminated concrete

    Directory of Open Access Journals (Sweden)

    Takenouti, H.

    2007-12-01

    Full Text Available Most studies published to date on the corrosion behaviour of stainless reinforcing steel are based on austenitic steel. The market presence of corrugated duplex steel is growing, however. The present study compared passivity in 2205 type duplex and 304 type austenitic stainless steel. Polarization tests in chloride-containing Ca(OH2 solutions confirmed the exceptional performance of duplex steels. X-ray photoelectronic spectroscopy (XPS showed that the passive layer generated on duplex stainless steel in media simulating concrete pore solutions had a higher Cr content than the layer formed on steel in contact with the air. The XPS results also revealed that in duplex steel the form adopted by the passive layer Fe oxides was Fe3O4 in the solutions simulating concrete, rather than Fe2O3, as in duplex steel exposed to air. Electrochemical impedance spectroscopy (EIS can be used to monitor the transformations taking place in the passive layer and analyze the factors involved.La mayoría de los estudios publicados hasta el momento sobre el comportamiento frente a la corrosión de armaduras de acero inoxidable se basan en aceros austeníticos. Sin embargo, la presencia en el mercado de aceros corrugados dúplex es cada vez más importante. En este trabajo se analiza la pasividad de un acero inoxidable dúplex tipo 2205 en comparación con la de un inoxidable austenítico tipo 304. Los ensayos de polarización en disoluciones de Ca(OH2 con cloruros confirman el excepcional comportamiento de los aceros dúplex. La espectroscopía fotoelectrónica de rayos X (XPS informa de que la capa pasiva generada en aceros inoxidables dúplex en medios que simulan la disolución de los poros del hormigón posee mayor contenido en óxidos de Cr que la formada en aire. También se puede deducir de los resultados de XPS que los óxidos de Fe de la capa pasiva de los aceros dúplex se encuentran en forma de Fe3O4 en las disoluciones que simulan el hormigón en vez de en

  12. Intramolecular Acylation of Aryl- and Aroyl-Aliphatic Acids by the Action of Pyrophosphoryl Chloride and Phosphorus Oxychloride

    Directory of Open Access Journals (Sweden)

    Saleh Rayyan

    2001-03-01

    Full Text Available Both pyrophosphoryl chloride and phosphorus oxychloride react with aryl aliphatic acids to form mixed anhydrides which undergo intramolecular acylation to afford cyclic ketones without the addition of a Friedel-Crafts catalyst. Aryl and aroylbenzoic acids could be cyclized to the corresponding anthrones and anthraquinones respectively.

  13. Corrosion Study of Stainless Steels in Peracetic Acid Bleach Media With and Without Chloride and Chelant

    Directory of Open Access Journals (Sweden)

    Rohtash

    2014-12-01

    Full Text Available The paper industries are adopting non-chlorine containing chemicals e.g. peroxide, ozone, peracids etc. as alternate of chlorine based bleach chemicals e.g. chlorine and chlorine dioxide etc. with the aim of eco-friend atmospheres. Changeover to the new chemicals in the bleaching process is likely to affect the metallurgy of the existing bleach plants due to change in the corrosivity of the media. Accordingly, corrosion investigations were performed in a peracid namely peracetic acid to test the suitability of austenitic stainless steels 654SMO, 265SMO, 2205, 317L and 316L. The performance of above stainless steels was evaluated through long term immersion tests and Electrochemical polarization measurements in peracetic acid (PAA bleach media at pH value 4 maintaining concentration 0.2 % as active oxygen along with three chloride levels 0, 500 and 1000 ppm in pulp-free laboratory. To study the effect of corrosion inhibitors with extending limit of chloride in liquors, measurements were also made with two types of chelants- EDTA & MgSO4. The results showed that corrosivity of PAA reduced by addition of chelant while increased with concentration of Cl¯. The results also exhibited that EDTA is better inhibitor than MgSO4.

  14. Containment of nitric acid solutions of Plutonium-238

    Science.gov (United States)

    Reimus, M. A. H.; Silver, G. L.; Pansoy-Hjelvik, L.; Ramsey, K. B.

    1999-01-01

    The corrosion of various metals that could be used to contain nitric acid solutions of Pu-238 has been studied. Tantalum and tantalum/2.5% tungsten resisted the test solvent better than 304L stainless steel and several INCONEL alloys. The solvent used to imitate nitric acid solutions of Pu-238 contained 70% nitric acid, hydrofluoric acid, and ammonium hexanitratocerate.

  15. Solubility of xenon in amino-acid solutions. II. Nine less-soluble amino acids

    Science.gov (United States)

    Kennan, Richard P.; Himm, Jeffrey F.; Pollack, Gerald L.

    1988-05-01

    Ostwald solubility (L) of xenon gas, as the radioisotope 133Xe, has been measured as a function of solute concentration, at 25.0 °C, in aqueous solutions of nine amino acids. The amino-acid concentrations investigated covered much of their solubility ranges in water, viz., asparagine monohydrate (0-0.19 M), cysteine (0-1.16 M), glutamine (0-0.22 M), histidine (0-0.26 M), isoleucine (0-0.19 M), methionine (0-0.22 M), serine (0-0.38 M), threonine (0-1.4 M), and valine (0-0.34 M). We have previously reported solubility results for aqueous solutions of six other, generally more soluble, amino acids (alanine, arginine, glycine, hydroxyproline, lysine, and proline), of sucrose and sodium chloride. In general, L decreases approximately linearly with increasing solute concentration in these solutions. If we postulate that the observed decreases in gas solubility are due to hydration, the results under some assumptions can be used to calculate hydration numbers (H), i.e., the number of H2O molecules associated with each amino-acid solute molecule. The average values of hydration number (H¯) obtained at 25.0 °C are 15.3±1.5 for asparagine, 6.8±0.3 for cysteine, 11.5±1.1 for glutamine, 7.3±0.7 for histidine, 5.9±0.4 for isoleucine, 10.6±0.8 for methionine, 11.2±1.3 for serine, 7.7± 1.0 for threonine, and 6.6±0.6 for valine. We have also measured the temperature dependence of solubility L(T) from 5-40 °C for arginine, glycine, and proline, and obtained hydration numbers H¯(T) in this range. Between 25-40 °C, arginine has an H¯ near zero. This may be evidence for an attractive interaction between xenon and arginine molecules in aqueous solution.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-01-01

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

  17. Stress corrosion cracking of 13% Cr martensitic steels in sodium chloride solutions in the presence of thiosulphate

    International Nuclear Information System (INIS)

    The stress corrosion cracking (SCC) susceptibility of 13% Cr martensitic (UNS S42000) and supermartensitic (UNS S41125) steels in sodium chloride solutions in the presence of thiosulphate was evaluated by slow strain rate tests (SSRT). The tests were performed in 5% sodium chloride solutions buffered at pH 2.7, 3.5, 4.5 and 6.0 in the absence and presence of thiosulphate in a concentration range between 10-6 and 10-3 M, at 25 ± 0.1 C. The electrochemical behaviour of the two steels in the different solutions was determined by recording the anodic and cathodic polarisation curves. 13% Cr martensitic steel showed SCC in 5% sodium chloride solutions with pH ≤ 4.5 in the presence of 3 x 10-6 thiosulphate. Decreasing the chloride ion concentration from 50 to 10 g/l, the critical concentration of thiosulphate to provoke SCC susceptibility increased from 3 x 10-6 to 1 x 10-5 M. The resistance to SCC of the supermartensitic steel was higher than that of the martensitic steel. The critical concentration of thiosulphate to induce SCC on the supermartensitic steel were 1 x 10-5 M at pH 2.7 and 1 x 10-4 M at pH 3.5. At pH ≥ 4.5 the supermartensitic steel did not crack. The anodic and cathodic polarisation curves evidenced the influence of the thiosulphate on the corrosion and the activation effect on the steels. The SCC of the two steels was attributed to hydrogen embrittlement produced by sulphur and hydrogen sulphide formed by dismutation and reduction of thiosulphate. (orig.)

  18. Comparison of the corrosion behavior and surface morphology of NiTi alloy and stainless steels in sodium chloride solution

    OpenAIRE

    Kožuh S.; Vrsalović L.; Gojić M.; Gudić S.; Kosec B.

    2016-01-01

    The corrosion behavior of NiTi alloy and stainless steels (AISI 316L and X2CrNiMoN22-5-3) in 0.9% sodium chloride (0.154 moll-1) solution was investigated using open circuit potential measurements, potentiodynamic polarization and electrochemical impedance spectroscopy measurements. Microstructural analyses before and after electrochemical tests were performed with the scanning electron microscopy (SEM) equipped with energy dispersive spectrometry (EDS). Th...

  19. SYNTESIS OF THE COMPLEXES OF MACROPOROUS SULFONATED RESINS WITH FERRIC CHLORIDE AND THEIR CATALYTIC BEHAVIOR FOR SETERIFICATION OF ACETIC ACID WITH BUTANOL

    Institute of Scientific and Technical Information of China (English)

    HuangWenqiang; HouXin; 等

    1997-01-01

    The complex resins prepared from macroporous sulfonated resin D72(H+ form) with ferric chloride or ferric chloride hexahydrate have both sites of Bronsted acid and Lewis acid.In the catalysis of exterification of acetic acid with butanol the complex resins show to have much higher catalytic activity than that of its matrix.a conventional sulfonated cation exchange resin D72.

  20. Antifungal activity of essential oils when associated with sodium chloride or fatty acids

    Directory of Open Access Journals (Sweden)

    Tantatoui-Elaraki, Abdelthafour

    1994-12-01

    Full Text Available The inhibition of mycelium growth in a Zygorhynchus sp. and an Aspergillus niger isolates was studied. The inhibition rates (IR caused by 4 essential oils (EO, 5 fatty acids and sodium chloride at various concentrations were determined in Sabouraud Dextrose Agar.
    A synergy of action was observed between sodium chloride at 7.5% and the EO of thyme (0.04%, camomile (0.4% and mugwort (0.2 and 0.1% on A. niger and between sodium chloride (5% and the EO of camomile (0.1% and mugwort (0.1 and 0.01% and sodium chloride (7.5% and eucalyptus EO (0.4 and 0.2% on Zygorhynchus sp.
    Camomile EO (0.13% associated with propionic acid (0.075%, lauric acid (0.05% or oleic acid (0.15% led to synergetic effect on Zygorhynchus sp. as well as thyme EO (0.04 and 0.05%, respectively with propionic acid (0.1% and linolenic acid (0.075% on A. niger. Other combinations exerted no higher effects than each of the substances used alone.
    Practical applications of the results observed were discussed

    Se ha estudiado la inhibición del crecimiento miceliar en un aislamiento de Zygorhynchus sp. y otro de Aspergillus niger. Se determinaron las tasas (o índices de inhibición (IR en Agar Sabouraud Dextrosa provocados por varias concentraciones de 4 aceites esenciales (EG, 5 ácidos grasos y cloruro sódico.
    Se observó un efecto sinérgico entre cloruro sódico al 7.5% y los aceites esenciales de tomillo (0.04%, manzanilla (0.4% y artemisa (0.2 y 0.1% sobre A. niger, y entre cloruro sódico (5% y los aceites esenciales de manzanilla (0.1% y de artemisa (0.1 y 0.01%, así como cloruro sódico (7.5% y aceite esencial de eucalipto (0.4 y 0.2%, sobre Zygorhynchus sp.
    El aceite esencial de manzanilla (0.13% en asociación con ácido propiónico (0.075%, ácido láurico (0.05% o ácido oleico (0.15% provocó un efecto sinérgico sobre Zygorhynchus sp., de la misma forma

  1. Comparison of adsorptions by rice hull and Lewatit TP 214 of platinum in chloride solution

    Directory of Open Access Journals (Sweden)

    Morcali M.H.

    2013-01-01

    Full Text Available Rice hull, a biomass waste product, and Lewatit TP 214, a thiosemicarbazide sorbent, were investigated as adsorbents for the adsorption of platinum (IV ions from synthetically prepared dilute chloroplatinic acid solutions. The rice hull was characterized by Attenuated Total Reflection-Fourier transform infrared spectroscopy (ATR-FTIR. The effects of the different adsorption parameters, sorbent dosage, contact time, temperature and pH of solution on adsorption percentage were studied in detail on a batch sorption. The adsorption equilibrium data were best fitted with the Langmuir isotherm model. The maximum monolayer adsorption capacities, Qmax, at 25°C were found to be 42.02 and 33.22 mg g-1 for the rice hull and Lewatit TP 214, respectively. Thermodynamic calculations using the measured ΔH°, ΔS° and ΔG° values indicate that the adsorption process was spontaneous and exothermic. The pseudo-first-order and pseudo-second-order rate equations were investigated; the adsorption of platinum ions for both sorbents was found to be described by the pseudo-second-order kinetic model. The kinetic rate, k2, using 30 mg sorbent at 25°C was found to be 0.0289 and 0.0039 g min-1 mg-1 for the rice hull and Lewatit TP 214, respectively. The results indicated that the rice hull can be effectively used for the removal of platinum from aqueous solution.

  2. Electrolytic regeneration of acid cupric chloride printed circuit board etchant. Final report, August 1, 1995--October 31, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Oxley, J.E.; Smialek, R.J.

    1997-04-18

    The overall objective of this ERIP program was to make substantial progress in further developing a process for electrolytic regeneration of acid cupric chloride etchant - a process which was initially demonstrated in in-house studies and EPA Phase I and Phase II SBIRs. Specific objectives of the work were: (1) to define optimum system operating conditions by conducting a systematic study of process parameters, (2) to develop or find a superior electrolyic cell separator material, (3) to determine an optimum activation procedure for the flow-through carbon/graphite felt electrodes which are so critical to process performance, (4) to demonstrate - on the pre-prototype scale - electrolytic compensation for oxygen ingress - which causes etchant solution growth, and (5) to begin engineering design work on a prototype-scale regeneration unit. Parametric studies looked at the effect that key plating parameters have on copper deposit quality. Parameters tested included (a) velocity past the plating cathodes, (b) copper concentration in the catholyte solution from which the copper is being plated, (c) plating current density, and (d) catholyte cupric ion concentration. The most significant effects were obtained for velocity changes. The work showed that catholyte velocities above 0.5 ft/sec were needed to get adequate plating at 77.5 mA/cm{sup 2} and higher currents, and that even higher flow was better.

  3. Sodium Chloride Diffusion in Low-Acid Foods during Thermal Processing and Storage.

    Science.gov (United States)

    Bornhorst, Ellen R; Tang, Juming; Sablani, Shyam S

    2016-05-01

    This study aimed at modeling sodium chloride (NaCl) diffusion in foods during thermal processing using analytical and numerical solutions and at investigating the changes in NaCl concentrations during storage after processing. Potato, radish, and salmon samples in 1% or 3% NaCl solutions were heated at 90, 105, or 121 °C for 5 to 240 min to simulate pasteurization and sterilization. Selected samples were stored at 4 or 22 °C for up to 28 d. Radish had the largest equilibrium NaCl concentrations and equilibrium distribution coefficients, but smallest effective diffusion coefficients, indicating that a greater amount of NaCl diffused into the radish at a slower rate. Effective diffusion coefficients determined using the analytical solution ranged from 0.2 × 10(-8) to 2.6 × 10(-8) m²/s. Numerical and analytical solutions showed good agreement with experimental data, with average coefficients of determination for samples in 1% NaCl at 121 °C of 0.98 and 0.95, respectively. During storage, food samples equilibrated to a similar NaCl concentration regardless of the thermal processing severity. The results suggest that sensory evaluation of multiphase (solid and liquid) products should occur at least 14 d after processing to allow enough time for the salt to equilibrate within the product. PMID:27060992

  4. Palladium-Catalyzed α-Arylation of Aryl Acetic Acid Derivatives via Dienolate Intermediates with Aryl Chlorides and Bromides

    OpenAIRE

    Sha, Sheng-Chun; Zhang, Jiadi; Walsh, Patrick J.

    2015-01-01

    To date, examples of α-arylation of carboxylic acids remain scarce. Using a deprotonative cross-coupling process (DCCP), a method for palladium-catalyzed γ-arylation of aryl acetic acids with aryl halides has been developed. This protocol is applicable to a wide range of aryl bromides and chlorides. A procedure for the palladium-catalyzed α-arylation of styryl acetic acids is also described.

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

    Science.gov (United States)

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

    2016-01-25

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

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

    Science.gov (United States)

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

    2016-01-25

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

  7. Kinetics and mechanism of the reaction of gold(III chloride complexes with formic acid

    Directory of Open Access Journals (Sweden)

    Pacławski K.

    2015-01-01

    Full Text Available In this work, the results of kinetic studies of the redox reaction of gold(III chloride complexes ([AuCl4]- with formic acid, are presented. Obtained data suggest the complex character of the reaction which leads to the [AuCl2]- and [AuCl3(COOH]- ions formation as intermediates. In the pH range over 2.5, the final product of the reaction is metallic gold. From the analysis of kinetic data, the rate limiting step is found to be the gold metallic phase formation. The stage of Au(III reduction is relatively fast with the second-order rate constant equal to 61.8 M-1s-1 at temperature 50ºC. The rate of the studied reaction depends on the temperature, reactants concentration and chloride ions concentration. As a result of the data analysis, the scheme of the reaction path has been suggested. Also, the values of enthalpy and entropy of activation for the reaction have been determined.

  8. Anion-exchange Studies of Radioactive Trace Elements in Sulphuric Acid Solutions

    International Nuclear Information System (INIS)

    As part of a chemical group separation procedure used as a pretreatment in gamma spectrometric analysis, a study has been made of the adsorption from sulphuric acid solutions on strongly basic anion exchange resins, prepared in the hydroxide and the sulphate forms, of trace activities of Na, P, K, Ca, Sc, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Rb, Sr, Zr, Nb, Mo, Tc, Ag, Cd, In, Cs, Ba, La, Ce, Hf, Ta, W, Ir, Pa and Np. Besides adsorbing some of the trace elements in the solution, the anion exchange resin in the hydroxide form will neutralize the bulk of the sulphuric acid. This makes possible the subsequent sequential separation of chloride complexes on short anion-exchange columns by a stepwise increasing of the HCl concentration of the solution. On the basis of the results obtained in the present and earlier experiments, a new improved chemical group-separation procedure for mixtures of radioactive trace elements is outlined

  9. Oral salt supplements to compensate for jejunostomy losses: comparison of sodium chloride capsules, glucose electrolyte solution, and glucose polymer electrolyte solution.

    OpenAIRE

    Nightingale, J M; Lennard-Jones, J E; Walker, E. R.; Farthing, M J

    1992-01-01

    Six patients with jejunostomies and residual jejunal lengths of 105 to 250 cm took the same food and water each day for eight study days. In random order, three methods of salt replacement were tested, each over 48 hours, against a period without added salt. During the three test periods the patients took 120 mmol of sodium chloride daily, as salt in gelatine capsules, as an isotonic glucose electrolyte (280 mOsmol/kg; 30 kcal) solution, and as a glucose polymer (Maxijul) solution (280 mOsmol...

  10. Nitric acid uptake by sulfuric acid solutions under stratospheric conditions - Determination of Henry's Law solubility

    Science.gov (United States)

    Reihs, Christa M.; Golden, David M.; Tolbert, Margaret A.

    1990-01-01

    The uptake of nitric acid by sulfuric acid solutions representative of stratospheric particulate at low temperatures was measured to determine the solubility of nitric acid in sulfuric acid solutions as a function of H2SO4 concentration and solution temperature. Solubilities are reported for sulfuric acid solutions ranging from 58 to 87 wt pct H2SO4 over a temperature range from 188 to 240 K, showing that, in general, the solubility of nitric acid increases with decreasing sulfuric acid concentration and with decreasing temperature. The measured solubilities indicate that nitric acid in the global stratosphere will be found predominantly in the gas phase.

  11. Effects of temperature and pressure on stress corrosion cracking behavior of 310S stainless steel in chloride solution

    Science.gov (United States)

    Zhong, Yunpan; Zhou, Cheng; Chen, Songying; Wang, Ruiyan

    2016-06-01

    310S is an austenitic stainless steel for high temperature applications, having strong resistance of oxidation, hydrogen embrittlement and corrosion. Stress corrosion cracking(SCC) is the main corrosion failure mode for 310S stainless steel. Past researched about SCC of 310S primarily focus on the corrosion mechanism and influence of temperature and corrosive media, but few studies concern the combined influence of temperature, pressure and chloride. For a better understanding of temperature and pressure's effects on SCC of 310S stainless steel, prepared samples are investigated via slow strain rate tensile test(SSRT) in different temperature and pressure in NACE A solution. The result shows that the SCC sensibility indexes of 310S stainless steel increase with the rise of temperature and reach maximum at 10MPa and 160°C, increasing by 22.3% compared with that at 10 MPa and 80 °C. Instead, the sensibility decreases with the pressure up. Besides, the fractures begin to transform from the ductile fracture to the brittle fracture with the increase of temperature. 310S stainless steel has an obvious tendency of stress corrosion at 10MPa and 160°C and the fracture surface exists cleavage steps, river patterns and some local secondary cracks, having obvious brittle fracture characteristics. The SCC cracks initiate from inclusions and tiny pits in the matrix and propagate into the matrix along the cross section gradually until rupture. In particular, the oxygen and chloride play an important role on the SCC of 310S stainless steel in NACE A solution. The chloride damages passivating film, causing pitting corrosion, concentrating in the cracks and accelerated SSC ultimately. The research reveals the combined influence of temperature, pressure and chloride on the SCC of 310S, which can be a guide to the application of 310S stainless steel in super-heater tube.

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

    International Nuclear Information System (INIS)

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

  13. Chemistry of ruthenium in nitric acid solution with special regard to nuclear fuel solutions

    International Nuclear Information System (INIS)

    A review is given concerning the published knowledge about the chemistry of ruthenium in nitric acid solution with special reference to nitric acid nuclear fuel solutions. Possibilities of the spectroscopic description of the different existing ruthenium complexes are discussed and papers are presented dealing with the estimation of the proportions of the different ruthenium compounds in nuclear fuel solutions. Finally, arguments are derived for the preparation of ruthenium-containing model solutions, which adequately simulate the composition of real nuclear fuel solutions. (author)

  14. Aerobic oxidation of benzylic aldehydes to acids catalyzed by iron (Ⅲ) meso-tetraphenylporphyrin chloride under ambient conditions

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Highly efficient aerobic oxidation of benzylic aldehydes to the corresponding acids catalyzed by iron (Ⅲ) meso-tetraphenylporphyrin chloride (Fe(TPP)Cl) under ambient conditions was developed. The catalyst has been proved to be an excellent catalyst for the system in the presence of molecular oxygen and isobutryaldehyde at room temperature.

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

    Science.gov (United States)

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

    2016-08-01

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

  16. Synergistic effect between cationic gemini surfactant and chloride ion for the corrosion inhibition of steel in sulphuric acid

    Energy Technology Data Exchange (ETDEWEB)

    Qiu Lingguang [School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039 (China)], E-mail: lgqiu@ahu.edu.cn; Wu Yun; Wang Yimin; Jiang Xia [School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039 (China)

    2008-02-15

    Corrosion inhibition of cold rolled steel in 0.5 mol L{sup -1} sulphuric acid by a quaternary ammonium gemini surfactant, l,3-propane-bis(dimethyl dodecylammonium bromide) (designated as 12-3-12), in the absence and presence of chloride ions was investigated at different temperatures. The results revealed significant synergistic effect between gemini 12-3-12 and chloride ions for the corrosion protection of cold rolled steel in sulphuric acid, and that the novel composite inhibitor system containing cationic gemini surfactant and chloride ions was efficient and low-cost for steel corrosion inhibition in sulphuric acid medium, even when concentration of 12-3-12 was as low as 1 x 10{sup -6} mol L{sup -1}. By fitting the obtained experimental data with Langmuir adsorption model and Arrhenius equation, some thermodynamic and kinetic parameters such as adsorption free energy, the apparent activation energy, and the pre-exponential factor were estimated. The adsorption mechanism of the gemini surfactant onto steel surface in acid medium in the absence and presence of chloride ions was also discussed, respectively.

  17. Antimicrobial Efficacy of a Sulfuric Acid and Sodium Sulfate Blend, Peroxyacetic Acid, and Cetylpyridinium Chloride against Salmonella on Inoculated Chicken Wings.

    Science.gov (United States)

    Scott, Brittney R; Yang, Xiang; Geornaras, Ifigenia; Delmore, Robert J; Woerner, Dale R; Reagan, James O; Morgan, J Brad; Belk, Keith E

    2015-11-01

    Studies were conducted to evaluate the efficacy of a commercial blend of sulfuric acid and sodium sulfate (SSS) in reducing Salmonella on inoculated whole chilled chicken wings and to compare its efficacy to peroxyacetic acid (PAA) and cetylpyridinium chloride (CPC). Wings were spot inoculated (5 to 6 log CFU/ml of sample rinsate) with a five-strain mixture of novobiocin- and nalidixic acid-resistant Salmonella and then left untreated (control) or treated by immersing individual wings in 350 ml of antimicrobial solution. An initial study evaluated two treatment immersion times, 10 and 20 s, of SSS (pH 1.1) and compared cell recoveries following rinsing of treated samples with buffered peptone water or Dey/Engley neutralizing broth. In a second study, inoculated wings were treated with SSS (pH 1.1; 20 s), PAA (700 ppm, 20 s), or CPC (4,000 ppm, 10 s) and analyzed for survivors immediately after treatment (0 h) and after 24 h of aerobic storage at 4°C. Color and pH analyses were also conducted in the latter study. Recovery of Salmonella survivors following treatment with SSS (10 or 20 s) was not (P ≥ 0.05) affected by the type of cell recovery rinse solution (buffered peptone water or Dey/Engley neutralizing broth), but there was an effect (P Salmonella at 0 h increased in the order CPC , SSS , PAA; however, after 24 h of aerobic storage, pathogen counts of SSS- and PAA-treated wings did not differ (P ≥ 0.05). Overall, the results indicated that SSS applied at pH 1.1 for 20 s was an effective antimicrobial intervention to reduce Salmonella contamination on chicken wings.

  18. Calculated Third Order Rate Constants for Interpreting the Mechanisms of Hydrolyses of Chloroformates, Carboxylic Acid Halides, Sulfonyl Chlorides and Phosphorochloridates

    Directory of Open Access Journals (Sweden)

    T. William Bentley

    2015-05-01

    Full Text Available Hydrolyses of acid derivatives (e.g., carboxylic acid chlorides and fluorides, fluoro- and chloroformates, sulfonyl chlorides, phosphorochloridates, anhydrides exhibit pseudo-first order kinetics. Reaction mechanisms vary from those involving a cationic intermediate (SN1 to concerted SN2 processes, and further to third order reactions, in which one solvent molecule acts as the attacking nucleophile and a second molecule acts as a general base catalyst. A unified framework is discussed, in which there are two reaction channels—an SN1-SN2 spectrum and an SN2-SN3 spectrum. Third order rate constants (k3 are calculated for solvolytic reactions in a wide range of compositions of acetone-water mixtures, and are shown to be either approximately constant or correlated with the Grunwald-Winstein Y parameter. These data and kinetic solvent isotope effects, provide the experimental evidence for the SN2-SN3 spectrum (e.g., for chloro- and fluoroformates, chloroacetyl chloride, p-nitrobenzoyl p-toluenesulfonate, sulfonyl chlorides. Deviations from linearity lead to U- or V-shaped plots, which assist in the identification of the point at which the reaction channel changes from SN2-SN3 to SN1-SN2 (e.g., for benzoyl chloride.

  19. Containment of nitric acid solutions of Plutonium-238

    International Nuclear Information System (INIS)

    The corrosion of various metals that could be used to contain nitric acid solutions of Pu-238 has been studied. Tantalum and tantalum/2.5% tungsten resisted the test solvent better than 304L stainless steel and several INCONEL alloys. The solvent used to imitate nitric acid solutions of Pu-238 contained 70% nitric acid, hydrofluoric acid, and ammonium hexanitratocerate. copyright 1999 American Institute of Physics

  20. Novel short chain fatty acids restore chloride secretion in cystic fibrosis

    International Nuclear Information System (INIS)

    Phenylalanine deletion at position 508 of the cystic fibrosis transmembrane conductance regulator (ΔF508-CFTR), the most common mutation in cystic fibrosis (CF), causes a misfolded protein exhibiting partial chloride conductance and impaired trafficking to the plasma membrane. 4-Phenylbutyrate corrects defective ΔF508-CFTR trafficking in vitro, but is not clinically efficacious. From a panel of short chain fatty acid derivatives, we showed that 2,2-dimethyl-butyrate (ST20) and α-methylhydrocinnamic acid (ST7), exhibiting high oral bioavailability and sustained plasma levels, correct the ΔF508-CFTR defect. Pre-incubation (≥6 h) of CF IB3-1 airway cells with ≥1 mM ST7 or ST20 restored the ability of 100 μM forskolin to stimulate an 125I- efflux. This efflux was fully inhibited by NPPB, DPC, or glibenclamide, suggesting mediation through CFTR. Partial inhibition by DIDS suggests possible contribution from an additional Cl- channel regulated by CFTR. Thus, ST7 and ST20 offer treatment potential for CF caused by the ΔF508 mutation

  1. 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)

  2. The beneficial effect of ruthenium additions on the passivation of duplex stainless steel corrosion in sodium chloride solutions

    Energy Technology Data Exchange (ETDEWEB)

    Sherif, El-Sayed M. [DST/NRF Centre of Excellence in Strong Materials, School of Physics, University of the Witwatersrand, Johannesburg, Wits 2050 (South Africa); Center of Excellence for Research in Engineering Materials (CEREM), College of Engineering, King Saud University, P. O. Box 800, Al-Riyadh 11421 (Saudi Arabia)], E-mail: esherif@ksu.edu.sa; Potgieter, J.H. [Chemistry and Materials Division, School of Biology, Chemistry and Health Sciences, Manchester Metropolitan University, Oxford Road, Manchester M1 5GD (United Kingdom); Comins, J.D. [DST/NRF Centre of Excellence in Strong Materials, School of Physics, University of the Witwatersrand, Johannesburg, Wits 2050 (South Africa); Cornish, L.; Olubambi, P.A.; Machio, C.N. [DST/NRF Centre of Excellence in Strong Materials, School of Chemical and Metallurgical Engineering, University of the Witwatersrand, Johannesburg, Wits 2050 (South Africa)

    2009-06-15

    The effect of varying ruthenium contents of 0.00, 0.14, 0.22, and 0.28% on the corrosion of 22%Cr-9%Ni-3%Mo duplex stainless steel (DSS) after different immersion intervals in 3.5% NaCl solutions has been investigated. The study was carried out using open-circuit potential, potentiodynamic cyclic polarization, chronoamperometry, electrochemical impedance spectroscopy, and weight-loss measurements. Particular attention was paid to the effect of Ru on the pitting corrosion of DSS in the chloride solutions. Electrochemical measurements indicated that the presence of Ru passivates the DSS alloy by decreasing its corrosion parameters. Furthermore, it shifts the corrosion and pitting potentials to more positive values. This effect was found to increase with increasing Ru content and also with increased immersion time of the alloy in the chloride solution before measurements. Weight-loss time data after varied exposure periods (4-20 days) showed that the weight-loss and corrosion rate of DSS significantly decrease with increasing Ru contents.

  3. Infrared Spectroscopic Study of the Adsorption Forms of Cyanuric Acid and Cyanuric Chloride on TiO2.

    Science.gov (United States)

    Chien, Tzu-En; Li, Kun-Lin; Lin, Po-Yuan; Lin, Jong-Liang

    2016-05-31

    Cyanuric acid is often found to be the end product in the hydrolysis of waste melamine and in the TiO2-mediated photocatalytic decomposition of s-triazine-containing compounds used as herbicides or dyes. The photocatalytically recalcitrant nature of cyanuric acid on TiO2 may be closely related to its adsorption properties, including the tautomeric forms present on the surfaces and their bonding structures, which remain to be determined. In this paper, we present the optimized adsorption structures of the four tautomeric isomers (triketo, diketo, monoketo, and triol) of cyanuric acid on a model rutile-TiO2(110) surface and their vibrational absorptions. Experimentally, the adsorption structures of cyanuric acid and chloride on powdered TiO2 are analyzed on the basis of the theoretically obtained, characteristic infrared information. Cyanuric acid on TiO2 at 35 °C exists in triketo and hydroxylated forms, but the diketo becomes the predominant form on the surface at 250 °C, being bonded to a titanium site via one of its carbonyl groups and with a N-H···O hydrogen bonding interaction. Hydroxylation of cyanuric chloride occurs as it is adsorbed on TiO2 at 35 °C. Upon being heated to 200 °C, the surface is mainly covered with the diketo form of cyanuric acid after the adsorption of cyanuric chloride. PMID:27176610

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

    Science.gov (United States)

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

    2016-01-01

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

  5. Electrochemical behavior of enamel-coated carbon steel in simulated concrete pore water solution with various chloride concentrations

    International Nuclear Information System (INIS)

    Highlights: ► All enamels significantly improve the corrosion performance of steel in Ca(OH)2 with chloride. ► Pitting corrosion of uncoated and ME-coated steel occurred at different chloride concentrations. ► Calcium silicate mixed in enamel increased the cohesive strength of ME coating. ► The increased pores in inner layer reduced the cohesive strength of DE coating. ► The electrochemical properties of enamel-coated steel are sensitive to thickness variation. -- Abstract: The electrochemical behavior of enamel coated carbon steel in simulated concrete pore water solution with various chloride concentrations was investigated by open circuit potential, linear polarization resistance, and electrochemical impedance spectroscopy tests. The phase composition, microstructure, and tensile strength of enamels were characterized by X-ray diffraction, scanning electron microscopy, and pull-off tests. Three types of coatings with pure, mixed, and double enamels were studied and compared for their corrosion behavior. Test results indicated that all three types of enamel coatings can reduce the corrosion current density of carbon steel in an alkaline environment with chloride; the pure and double coatings are superior to the mixed enamel coating. Cohesive failures were observed within the three coatings while their interface with the steel substrate remained intact. In comparison with the pure enamel, the mixed enamel was stronger with smaller open channels formed due to the addition of calcium silicate and the double enamel was weaker with larger air bubbles trapped in the inner pure enamel layer by the outer mixed enamel layer

  6. Electrical conductivity of aqueous solutions of perrhenic acid

    International Nuclear Information System (INIS)

    The physiocochemical properties of perrhenic acid, HReO4, are studied; its salts form the basis of solutions for electrochemical production of rhenium. Information is presented from which the electrical conductivity of solutions in the temperature range 15-90 degrees can be determined from known concentrations of the acid in water and vice versa

  7. Sol-gel Transition of Methylcellulose Solution in the Coexistence of Hexadecyltrimethylammonium Bromide and Sodium Chloride

    Institute of Scientific and Technical Information of China (English)

    Shah Zhou; Hai-yang Yang; Yong-jun Xie; Hua-zhen Li; Guang-ming Liu

    2011-01-01

    The sol-gel transition of methylcellulose (MC) solution in the presence of NaCl and hexadecyltrimethylammonium bromide (HTAB),together with MC/NaCl solution in the presence of HTAB and MC/HATB solution in the presence of NaCl,was investigated by the rheological measurements.It has been found that the sol-gel transition temperature of MC solution decreases linearly with the concentration of NaCl in solution but increases linearly with the concentration of HTAB in solution,respectively.However,the sol-gel transition temperature of MC/NaCl solution in the presence of HTAB keeps the same value,independent of the concentration of HTAB in solution.On the other hand,the sol-gel transition temperature of MC/HTAB solution decreases linearly with the concentration of NaCl in solution.The experimental results suggest that,for MC/NaCl solution in the presence of HTAB,the saltinduced spherical micelles of HTAB should have formed in bulk solution.For MC solution in the absence of NaCl,no spherical micelles have been formed in bulk solution,though the concentration of HTAB in our experiment is almost one order of magnitude higher than the critical micelle concentration of HTAB in polymer-free solution.In fact,due to adsorption of HTAB on MC chains,the realconcentration of HTAB in bulk solution,is much less than the apparent concentration of HTAB dissolved in MC solution.

  8. Corrosion behaviour of 316L stainless steel and anti-corrosion materials in a high acidified chloride solution

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Z.H. [Shanghai University of Electric Power, Shanghai Engineering Research Center of Energy-Saving in Heat Exchange Systems, Shanghai Key Laboratory of Colleges and Universities for Corrosion Control in Electric Power System and Applied Electrochemistry, 2103 Pingliang Road, Shanghai 200090 (China); Ge, H.H., E-mail: gehonghua@shiep.edu.cn [Shanghai University of Electric Power, Shanghai Engineering Research Center of Energy-Saving in Heat Exchange Systems, Shanghai Key Laboratory of Colleges and Universities for Corrosion Control in Electric Power System and Applied Electrochemistry, 2103 Pingliang Road, Shanghai 200090 (China); Lin, W.W. [Shanghai University of Electric Power, Shanghai Engineering Research Center of Energy-Saving in Heat Exchange Systems, Shanghai Key Laboratory of Colleges and Universities for Corrosion Control in Electric Power System and Applied Electrochemistry, 2103 Pingliang Road, Shanghai 200090 (China); Zong, Y.W.; Liu, S.J. [Power Plant of Baoshan Iron and Steel Co., Ltd, Tieli Road, Shanghai 200941 (China); Shi, J.M. [Technical University of Braunschweig (Germany)

    2014-12-15

    Highlights: • Severe general corrosion accompanied by localized pitting occurred on 316L SS surface in a high acidified chloride solution. • Surface roughness, surface potential difference and the electrochemical non-homogeneity of 316L SS in the test solution were investigated. • TA2, type 2507 SS and type 254SMo SS exhibit good corrosion resistance in the test solution. - Abstract: The corrosion behaviour of a type 316L (UNS S31603) stainless steel (SS) expansion joint in a simulated leaching solution of sediment on blast furnace gas pipeline in a power plant is investigated by using dynamic potential polarization curves, electrochemical impedance spectroscopy (EIS), optical microscope, atomic force microscope (AFM) and Scan Kelvin Probe (SKP). Severe general corrosion accompanied by pitting corrosion occurs on the type 316L SS surface in this solution. As the immersion period increases, the charge transfer resistance R{sub ct} decreases, the dissolution rate accelerates, the surface roughness increases and the surface potential difference enhances significantly. Then eight corrosion-resistant materials are tested, the corrosion rates of type 254SMo SS, type 2507 SS and TA2 are relatively minor in the solution. The corrosion resistance properties of TA2 is most excellent, indicating it would be the superior material choice for blast furnace gas pipeline.

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  11. 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. ...

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

    Science.gov (United States)

    Mamontov, E; Ohl, M

    2013-07-14

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

  13. Conductivity of Oxalic Acid in Aqueous Solution at Low Concentration

    Institute of Scientific and Technical Information of China (English)

    倪良; 韩世钧

    2005-01-01

    Oxalic acid is a weak and unsymmetrical bi-basic acid. There exist dissociation and association equilibria among the species in aqueous solution. The molar conductivity of the solution is the sum of the ionic contributions.Based on this idea, a new prediction equation of ionic conductivity was proposed at low concentration. The molar conductivities of the solution and its relevant ions were calculated respectively. The results obtained were in good agreement with those from experiments and the Quint-Viallard equation.

  14. Polymer-clay nanocomposites obtained by solution polymerization of vinyl benzyl triammonium chloride in the presence of advanced functionalized clay

    Indian Academy of Sciences (India)

    Raluca Ianchis; Dan Donescu; Ludmila Otilia Cinteza; Violeta Purcar; Cristina Lavinia Nistor; Critian Petcu; Cristian Andi Nicolae; Raluca Gabor; Silviu Preda

    2014-05-01

    Polymer-clay nanocomposites were synthesized by solution polymerization method using advanced functionalized clay and vinyl benzyl trimethyl ammonium chloride as monomer. First stage consisted in the silylation of a commercial organo-modified clay-Cl 20A using alkoxysilanes with different chain lengths. In the second step, the synthesis and characterization of polymer-nanocomposites were followed. To evaluate the clay functionalization process as well as the final polymer-clay products, thermogravimetric,X-ray diffraction, dynamic light scattering, Fourier transform infrared spectroscopy and three test liquid contact angles analyses were used. The loss of ammonium ions from commercial clay, the grafting degree, the lengths and the nature of alkyl chain influence the dispersion of the advanced modified clay into the polymer solution and, furthermore, the properties of the final polymer-clay nanocomposite film.

  15. Enhanced coagulation of ferric chloride aided by tannic acid for phosphorus removal from wastewater.

    Science.gov (United States)

    Zhou, Yunan; Xing, Xin-Hui; Liu, Zehua; Cui, Liwen; Yu, Anfeng; Feng, Quan; Yang, Haijun

    2008-05-01

    Phosphorus removal from wastewater is of great importance. In the present study, ferric chloride was selected as the coagulant, and tannic acid (TA), a natural polymer, as the coagulant aid to develop an effective coagulation process with the emphasis of phosphorus recovery from different types of wastewater. The results showed that TA can accelerate the settling speed by forming flocs with large size, reduce the residual Fe(III) to eliminate the yellow color caused by Fe(III), and slightly increase the phosphorus removal efficiency. The precipitate formed by TA-aided coagulation showed the advantage of releasing phosphorus faster than ferric phosphate, indicating the possibility of phosphorus recovery from wastewater as slow release fertilizer. To further understand the structural characteristics of the precipitate, analytical techniques such as Raman spectroscopy, X-ray photoelectron spectroscopy and matrix-assisted laser desorption ionization-time of flight mass spectrometry were employed. The analytical results indicated that TA-Fe-P complex was formed during the coagulation/flocculation processes. Solid phase in the precipitate consisted of TA-Fe-P complex, Fe-TA complex and/or ferric hydroxyphosphate. PMID:18395769

  16. Analysis of Reaction Products of (Ethylenediamine) palladium(Ⅱ) Chloride and 5′-Deoxyguanylic Acid in Aqueous Solution by Liquid Chromatography-Inductively Coupled Plasma Mass Spectrometry and Electrospray Ionization Mass Spectrometry%液相色谱-电感耦合等离子质谱和电喷雾电离质谱研究乙二胺二氯合钯与鸟嘌呤脱氧核糖核苷酸反应产物

    Institute of Scientific and Technical Information of China (English)

    刘德晔; 朱峰; 马永建; 吉文亮; 刘华良

    2015-01-01

    A method based on HPLC-ICP-MS was established to separate the reaction products of ( ethylenediamine) palladium(Ⅱ) chloride([Pd ( en ) Cl2])and 5’-deoxyguanylic acid ( 5’-dGMP). Two reaction products were detected at pH 8. 0 with 25 mmol/L phosphate buffer solution as chromatography eluent. One was the main product with HPLC retention time of 2. 8 min, the other product’s retention time was 3.2 min. According to ESI-MS(MS/MS) study, m/z=510, 511, 512, 514, 516[M+1]+ parent ions ( abundances same to palladium isotopes) were detected. Further analysis showed that the main product was[Pd( en) ( N1-5’-dGMP) ]. However the other product was hardly to be detected by ESI-MS. By using HPLC-DAD and HPLC-ICP-MS, we found that the two reaction products had the same UV absorption spectra and palladium percentage content. Combined with other groups’research, the other reaction product was deduced as dimmer, trimer or tetramer form of[Pd( en) ( N1-5’-dGMP) ]. Further study revealed that[Pd( en) ( N1-5’-dGMP) ] was easily formed in acid solution while its polymer form was generated in alkaline solution. At pH 6. 0, [Pd(en)(N1-5’-dGMP)] was formed within 12 hours with good stability. Research also revealed that the total amount of two reaction products declined as reaction pH climbed.%建立了基于HPLC-ICP-MS分离乙二胺二氯合钯[Pd(en)Cl2]与鸟嘌呤脱氧核糖核苷酸5忆-dGMP反应产物的方法。方法得到两种能够随色谱流出的产物,产物在25 mmol/L磷酸盐缓冲液(pH 8.0)作为流动相时,得到的分离峰型良好。主产物保留时间为2.8 min,另一产物保留时间为3.2 min。主产物经富集后由ESI-MS(MS/MS)鉴定得到m/z 为510,511,512,514和516的[M +1]+分子离子峰且丰度比与Pd同位素元素一致,再通过碎片推断结构为[ Pd( en)( N1-5忆-dGMP)],另一种产物经HPLC-DAD解析发现紫外吸收光谱与[Pd(en)(N1-5忆-dGMP)]完全相同,HPLC-ICP-MS发现产物含Pd量也与[Pd(en)(N1-5忆-dGMP

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

    Science.gov (United States)

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

    2006-01-01

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

  18. Analysis of phthalic acid diesters, monoester, and other plasticizers in polyvinyl chloride household products in Japan.

    Science.gov (United States)

    Kawakami, Tsuyoshi; Isama, Kazuo; Matsuoka, Atsuko

    2011-01-01

    The aim of this study was to determine the concentrations of six phthalic acid diesters (PAEs) [di(2-ethylhexyl) phthalate (DEHP), di-n-butyl phthalate (DBP), butyl benzyl phthalate (BBP), diisononyl phthalate (DINP), di-n-octyl phthalate (DNOP), and diisodecyl phthalate (DIDP)], two non-phthalic plasticizers [di(2-ethylhexyl) adipate (DEHA), 2,2,4-trimethyl-1,3-pentanediol diisobutylate (TMPDIB)], and mono 2-ethylhexyl phthalate(MEHP) in polyvinyl chloride (PVC) household products that children often places in their mouths and/or contact with their skin (41 products, 47 samples) in Japan. The detection frequencies of the studied compounds were as follows: DEHP (79 %), DINP-2 (13 %), DINP-1 (11 %), DBP (8.5 %), DEHA (8.5 %), DIDP (4.3 %), and DNOP (2.1 %). Concentrations of these compounds ranged from 0.021 % to 48 %. BBP and TMPDIB were not detected in the all samples. Most samples contained DEHP and DINP at high concentrations over 0.1 %. High concentrations of PAEs were detected in PVC household products that appear appealing to children and can possibly be licked and chewed by them. Di(2-ethylhexyl) terephtalete, diisononyl 1,2-cyclohexanedicarboxylic acid, acetyl tributyl citrate, and di(2-ethylhexyl) 4-cyclohexene-1,2-dicarboxylate used as substitute plasticizers were also detected in several samples. MEHP was present in 70 % of the samples, with concentrations ranging from trace amounts to 140 μg/g. The ratios of MEHP against DEHP were 6.2 × 10(-4) to 1.6 × 10(-1) %. MEHP in the household products investigated in this study was most probably an impurity in DEHP. The high concentrations of PAEs detected in products that children often place in their mouth reveal the importance of replacing plasticizers in common household products, and not just children's toys, with safer alternatives.

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Wook Jae Yoo

    2014-10-01

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

  1. Solubilities of carbon dioxide in the eutectic mixture of levulinic acid (or furfuryl alcohol) and choline chloride

    International Nuclear Information System (INIS)

    Highlights: • Solubilities of carbon dioxide in six renewable deep eutectic solvents (DESs) have been reported. • The experimental data were well correlated by Henry’s law. • The dissolution Gibbs free energy, enthalpy, and entropy changes were derived. • The absorption capacities of CO2 in present DESs and other DESs as well as several ionic liquids were compared. - Abstract: The solubilities of carbon dioxide (CO2) in the renewable deep eutectic solvents (DESs) containing levulinic acid (or furfuryl alcohol) and choline chloride were determined at temperatures (303.15, 313.15, 323.15, and 333.15) K and pressures up to 600.0 kPa using an isochoric saturation method. The mole ratios of levulinic acid (or furfuryl alcohol) to choline chloride were fixed at 3:1, 4:1 and 5:1. Standard Gibbs free energy, dissolution enthalpy and dissolution entropy were calculated from Henry’s law constant of CO2 in the DESs. Results indicated that levulinic acid based DESs are more effective to capture CO2 than furfuryl alcohol based ones. The solubility of CO2 in the DESs increased with increasing mole ratio of levulinic acid (or furfuryl alcohol) to choline chloride as well as pressure and decreased with increasing temperature

  2. Effects of Chloride Ion on the Texture of Copper and Cu-ZrB2 Coatings Electrodeposited from Copper Nitrate Solution in Different Plating Modes

    Institute of Scientific and Technical Information of China (English)

    Dongming GUO; Min ZHANG; Zhuji JIN; Renke KANG

    2006-01-01

    For the first time, the texture of copper and Cu-ZrB2 coatings produced from copper nitrate solution was studied. Chloride ion shows different effects on the deposit texture under direct current(DC)and pulse ion concentration exceeds 20 mg/I. The addition of ZrB2 particles enhances the cathodic polarization of copper deposition, which improves the growth of(111)plane. However, this improvement can be eliminated by further addition of chloride ion.

  3. Thermophysical properties of sodium nitrate and sodium chloride solutions and their effects on fluid flow in unsaturated media

    International Nuclear Information System (INIS)

    Understanding movement of saline sodium nitrate (NaNO3) waste solutions is important for assessing the contaminant migration near leaking waste storage tanks in the unsaturated zone at the Hanford site (Washington, USA). The purpose of this study is to contribute a basic understanding of effects of the thermophysical behavior of NaNO3 solutions on fluid flow in unsaturated media. We first present mathematical expressions for the dependence of density, viscosity, solubility and vapor pressure of NaNO3 solutions on both salt concentration and temperature, which were determined by fitting from published measured data. Because the previous studies of thermophysical behavior of sodium chloride (NaCl) solutions can provide a basis for those of NaNO3 solutions, we also present a comparison of thermophysical properties of both salt solutions. We have implemented the functional thermophysical properties of NaNO3 solutions into a new TOUGH2 equation-of-state module EWASG-NaNO3, which is modified from a previous TOUGH2 equation-of-state module EWASG for NaCl. Using the simulation tool, we have investigated effects of the thermophysical properties on fluid flow in unsaturated media. The effect of density and viscosity of saline solutions has been long recognized. Here we focus our attention on the effect of vapor pressure lowering due to salinity. We present simulations of a one-dimensional problem to study this salinity-driven fluid flow. A number of simulations were performed using different values of thermal conductivity, permeability, and temperature, to illustrate conditions and parameters controlling these processes. Results indicate that heat conduction plays a very important role in this salinity-driven vapor diffusion by maintaining a nearly constant temperature. The smaller the permeability, the more water is transferred into the saline environment. Effects of permeability on water flow are also complicated by effects of capillary pressure and tortuosity. The higher

  4. Development of a stable solution of 5-aminolaevulinic acid for intracutaneous injection in photodynamic therapy.

    Science.gov (United States)

    de Blois, A W; Grouls, R J E; Ackerman, E W; Wijdeven, W J A

    2002-01-01

    Photodynamic therapy using 5-aminolaevulinic acid (ALA) as a photosensitiser is a new treatment modality for basal cell carcinomas. Until now ALA has been used topically as a cream. As this administration route leads sometimes to insufficient penetration in the skin, an intracutaneously injectable solution of ALA was developed. The influence of pH, concentration and temperature on the degradation of ALA in aqueous solution was investigated in order to optimise the formulation of the injection. In 0.1% ALA solutions with pH values between 4 and 8 a pH dependency of ALA degradation was shown, comprising fast decomposition at pH values higher than 7, whereas at a pH value of 6 or lower the solutions remained within the range of 90-110% of the initial concentration for at least 128 days. An increase of degradation rate with increasing concentrations became evident which is consistent with the supposed second-order degradation kinetics. After accelerated stability research at 63 degrees C and 85 degrees C a shelf life of 281 days for a 0.1% ALA solution pH 5 was calculated from an Arrhenius plot. A 2% ALA solution was proven to be isotonic. From our results a 0.1-2% ALA solution with pH 5 and an appropriate amount of sodium chloride to obtain isotonicity is recommended as an injectable solution. PMID:12181635

  5. Comparative Study of Berberis vulgaris Fruit Extract and Berberine Chloride Effects on Acetic Acid-Induced Colitis in Rats

    OpenAIRE

    Minaiyan, Mohsen; Ghannadi, Alireza; Mahzouni, Parvin; Jaffari-Shirazi, Elham

    2011-01-01

    Antioxidant and immunomodulatory effects of anthocyanins are abundant in berberry fruits suggesting that they may have beneficial effects on inflammatory bowel diseases (IBD). The present study was carried out to investigate the anti-colitic effect of Berberis vulgaris fruit extract (BFE) compared to berberine chloride (BEC) and corticosteroids using an animal model of acetic acid induced experimental colitis. BFE with three different doses (375, 750, and 1500 mg/Kg) was administered orally o...

  6. Visible-Light-Mediated Synthesis of Amides from Aldehydes and Amines via in Situ Acid Chloride Formation.

    Science.gov (United States)

    Iqbal, Naeem; Cho, Eun Jin

    2016-03-01

    An efficient visible-light photocatalysis-based one-pot amide synthesis method was developed; visible-light irradiation of a mixture of an aldehyde, tert-butyl hydrogen peroxide, and N-chlorosuccinimide using a Ru(bpy)3Cl2 photocatalyst afforded an acid chloride, which subsequently reacted with amine to yield the corresponding amide. The reaction was used to synthesize moclobemide and a D3 receptor intermediate. PMID:26836367

  7. Formation of polymer nanowires through electropolymerization of polybithiophene from mixed electrolyte solutions of tetrabutylammonium hexafluorophosphate and tetrabutylammonium chloride

    Energy Technology Data Exchange (ETDEWEB)

    Kantzas, Trissa T. [Department of Chemistry, University of Western Ontario, London, Ontario N6A 5B7 (Canada); Semenikhin, Oleg A., E-mail: osemenik@uwo.c [Department of Chemistry, University of Western Ontario, London, Ontario N6A 5B7 (Canada)

    2011-04-01

    Preparation of one-dimensional conducting polymer structures such as nanowires and nanotubes require anisotropic growth conditions. Usually, such conditions are achieved by applying a certain template or by patterning the substrate. In this work, we employ a new approach to facilitate the anisotropic growth of electrochemically deposited polybithiophene through variations of the conductivity of the growing material. If the deposited material varies in conductivity, the areas with less conducting material will sustain little or no electrochemical current and only the areas with sufficient conductivity will experience further growth. In this work, the conductivity variations and the resulting anisotropic growth are achieved by performing electropolymerization in mixed electrolyte solutions of tetrabutylammonium hexafluorophosphate and tetrabutylammonium chloride. No growth can be observed in pure tetrabutylammonium chloride because the resulting films are insulating. However, addition of small amounts of tetrabutylammonium hexafluorophosphate was found to selectively activate local nanometer-sized areas of the polymer surface where polymer nanowire growth was observed. The latter was confirmed by atomic-force microscopy (AFM). The local properties of the polymer nanostructures obtained with varying contents of tetrabutylammonium hexafluorophosphate were characterized.

  8. Ionisation constants of inorganic acids and bases in aqueous solution

    CERN Document Server

    Perrin, D D

    2013-01-01

    Ionisation Constants of Inorganic Acids and Bases in Aqueous Solution, Second Edition provides a compilation of tables that summarize relevant data recorded in the literature up to the end of 1980 for the ionization constants of inorganic acids and bases in aqueous solution. This book includes references to acidity functions for strong acids and bases, as well as details about the formation of polynuclear species. This text then explains the details of each column of the tables, wherein column 1 gives the name of the substance and the negative logarithm of the ionization constant and column 2

  9. Study on Treatment of acidic and highly concentrated fluoride waste water using calcium oxide-calcium chloride

    Science.gov (United States)

    Ren, T.; Gao, X. R.; Zheng, T.; Wang, P.

    2016-08-01

    There are problems with treating acidic waste water containing high concentration fluorine by chemical precipitation, including the low sludge setting velocity and the high difficulty of reaching the criterion. In Heilongjiang province, a graphite factory producing high-purity graphite generates acidic waste water with a high concentration of fluorine. In this paper, the effect of removals on the concentration of fluoride with the combined treatment of calcium oxide and calcium chloride were discussed with regard to acid waste water. The study improved the sludge characteristics by using polyacrylamide (PAM) and polymeric aluminum chloride (PAC). The effect of different coagulants on sludge was evaluated by the sludge settlement ratio (SV), sludge volume index (SVI) and sludge moisture content. The results showed that the optimal combination for 100 ml waste water was calcium oxide addition amount of 14 g, a calcium chloride addition amount of 2.5 g, a PAM addition amount of 350 mg/L, and the effluent fluoride concentration was below 6 mg/L. PAM significantly improved the sludge settling velocity. The sludge settlement ratio reduced from 87.6% to 60%. The process for wastewater treatment was easily operated and involved low expenditure.

  10. Corrosion protection of aluminium pretreated by vinyltriethoxysilane in sodium chloride solution

    International Nuclear Information System (INIS)

    The corrosion protection of vinyltriethoxysilane (VTES) films on aluminium during exposure to 3% NaCl was investigated using electrochemical impedance spectroscopy (EIS), potential-time measurements and optical microscopy coupled with image analysis. Composition and thickness of films were analyzed using Auger electron spectroscopy (AES) combined with depth profiling. It was shown that films deposited from 5% solution were significantly thicker and exhibited lower porosity and better corrosion stability, as compared to films deposited from 2 vol.% solution. VTES films deposited from 5 vol.% solutions and cured for 30 min exhibited better protection properties than other investigated films.

  11. Corrosion behaviour of Fe-Mn-Si-Al austenitic steel in chloride solution

    OpenAIRE

    W. Krukiewicz; A. Grajcar; M. Opiela

    2009-01-01

    Purpose: The aim of the paper is to investigate the corrosion behaviour of the new-developed high-manganese austenitic steel in 0.5n NaCl solution.Design/methodology/approach: The steel used for the investigation was thermomechanically rolled and solution heat-treated from a temperature of 850°C. Corrosion resistance of investigated steel was examined using weight and potentiodynamic methods. In the weight method, the specimens were immersed in the prepared solution for 24h. In the potentiody...

  12. Growth/no growth interfaces of table olive related yeasts for natamycin, citric acid and sodium chloride.

    Science.gov (United States)

    Arroyo-López, F N; Bautista-Gallego, J; Romero-Gil, V; Rodríguez-Gómez, F; Garrido-Fernández, A

    2012-04-16

    The present work uses a logistic/probabilistic model to obtain the growth/no growth interfaces of Saccharomyces cerevisiae, Wickerhamomyces anomalus and Candida boidinii (three yeast species commonly isolated from table olives) as a function of the diverse combinations of natamycin (0-30 mg/L), citric acid (0.00-0.45%) and sodium chloride (3-6%). Mathematical models obtained individually for each yeast species showed that progressive concentrations of citric acid decreased the effect of natamycin, which was only observed below 0.15% citric acid. Sodium chloride concentrations around 5% slightly increased S. cerevisiae and C. boidinii resistance to natamycin, although concentrations above 6% of NaCl always favoured inhibition by this antimycotic. An overall growth/no growth interface, built considering data from the three yeast species, revealed that inhibition in the absence of citric acid and at 4.5% NaCl can be reached using natamycin concentrations between 12 and 30 mg/L for growth probabilities between 0.10 and 0.01, respectively. Results obtained in this survey show that is not advisable to use jointly natamycin and citric acid in table olive packaging because of the observed antagonistic effects between both preservatives, but table olives processed without citric acid could allow the application of the antifungal.

  13. 常压下H2O+HCl+MgCl2与H2O+HCl+CaCl2体系的汽液平衡%Vapor-Liquid Equilibria for Water+Hydrochloric Acid+Magnesium Chloride and Water+Hydrochloric Acid+Calcium Chloride Systems at Atmospheric Pressure

    Institute of Scientific and Technical Information of China (English)

    张颖; 周荣琪

    2006-01-01

    Vapor-liquid equilibria for water+hydrochloric acid+magnesium chloride and water+hydrochloric acid+calcium chloride systems at atmospheric pressure were measured using a Othmer-type equilibrium still. The experimental data are correlated using a modified Meissner's method. Satisfactory agreements are obtained between the experimental and the calculated results.

  14. The extraction of zinc from chloride solutions using dibutyl butylphosphonate (DBBP in Exxsol D100

    Directory of Open Access Journals (Sweden)

    Alguacil, F. J.

    1999-08-01

    Full Text Available The reaction of zinc chloride with dibutyl butylphosphonate in Exxsol D100 has been studied. The distribution coefficient of zinc is independent of equilibrium pH, thus, suggesting a solvation extraction reaction. Experimental data indicate that this reaction is exothermic (AH°=-28.4 kJ/mol. Slope analysis for the system at various DBBP concentrations reveals the formation in the loaded organic phases of species which probable 1:2 (Zn:DBBP stoichiometries. This was confirmed by results obtained at full DBBP Zn-loading capacity. The stoichiometric factor of water in the extraction reaction is found to be 4, whereas experimental data also indicated that two chloride ions are involved for each metal extracted, resulting in a ZnCl2∙2L∙4H2O stoichiometry (L represents the extractant.

    Se estudia la extracción de zinc, en medio cloruro, con el dibutil butilfosfonato disuelto en Exxsol D100. El coeficiente de distribución del metal es independiente del pH de equilibrio de la fase acuosa, lo que sugiere un mecanismo de extracción por solvatación. Los resultados experimentales indican que la reacción es exotérmica (AH°=-28,4 kJ/mol. Mediante análisis de la pendiente obtenida cuando se emplean distintas concentraciones de DBBP en la extracción de zinc se deduce la formación de una especie con estequiometría 1:2 (Zn:DBBP en la fase orgánica. Este hecho se confirma con los resultados obtenidos cuando se satura completamente la fase orgánica. En esta fase, el factor estequiométrico para el agua es 4, mientras que para el ion cloruro es 2, por lo que la especie extraída tiene una estequiometría final representada por ZnCl2∙2L∙4H2O (L representa al agente de extracción.

  15. POLYMER-SUPPORTED LEWIS ACID CATALYSTS. VI. POLYSTYRENE-BONDED STANNIC CHLORIDE CATALYST

    Institute of Scientific and Technical Information of China (English)

    RAN Ruicheng; FU Diankui

    1991-01-01

    A polystyrene-bonded stannic chloride catalyst was synthesized by the method of lithium polystyryl combined with stannic chloride. This catalyst is a polymeric organometallic compound containing 0.25 mmol Sn(IV)/g catalyst. The catalyst showed sufficient stability and catalytic activity in organic reaction such as esterification, acetalation and ketal formation, and it could be reused many times without losing its catalytic activity.

  16. Decomposition Studies of Triphenylboron, Diphenylborinic Acid and Phenylboric Acid in Aqueous Alkaline Solutions Containing Copper

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, C.L. [Westinghouse Savannah River Company, AIKEN, SC (United States); Peterson, R. A.

    1997-02-11

    This report documents the copper-catalyzed chemical kinetics of triphenylboron, diphenylborinic acid and phenylboric acid (3PB, 2PB and PBA) in aqueous alkaline solution contained in carbon-steel vessels between 40 and 70 degrees C.

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

    Science.gov (United States)

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

    2016-01-25

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

  18. Effect of heat treatment on pitting corrosion of austenitic Cr-Ni-Mo steels in sodium chloride solution

    International Nuclear Information System (INIS)

    The pitting corrosion resistance of Cr17Ni12Mo2,5 type steel under potentiostatic polarization in a sodium chloride solution is adversely affected by previous annealing. The data obtained were systematically dependent on annealing temperature, time and surface roughness. The corrosion current, the number of pits or the mean area of pit opening and the corrosion rate within the pits were increased by previous annealing at 550 to 7500C for 1-100 hrs. The highest corrosion rate estimated corresponded to heat treatments provoking severe sensitization to intergranular corrosion. The paercentage area of corrosion pit openings and the estimated pit penetration rates were several times higher for as-machined than for polished surfaces. It can be assumed that pitting corrosion is little affected by the carbon content and that molybdenum depletion of grain-boundary zones is responsible for the reduced pitting resistance of annealed steels. (orig./HP)

  19. Electrochemical oxidation of acid black 210 dye on the boron-doped diamond electrode in the presence of phosphate ions: Effect of current density, pH, and chloride ions

    International Nuclear Information System (INIS)

    The electrochemical oxidation of acid black 210 dye (AB-210) on the boron-doped diamond (BDD) was investigated under different pH conditions. The best performance for the AB-210 oxidation occurred in alkaline phosphate solution. This is probably due to oxidizing agents such as phosphate radicals and peroxodiphosphate ions, which can be electrochemically produced with good yields on the BDD anode, mainly in alkaline solution. Under this condition, the COD (chemical oxygen demand) removal was higher than that obtained from the model proposed by Comninellis. Electrolyses performed in phosphate buffer and in the presence of chloride ions resulted in faster COD and color removals in acid and neutral solutions, but in alkaline phosphate solution, a better performance in terms of TOC removal was obtained in the absence of chloride. Moreover, organochloride compounds were detected in all electrolyses performed in the presence of chloride. The AB-210 electrooxidation on BDD using phosphate as supporting electrolyte proved to be interesting since oxidizing species generated from phosphate ions were able to completely degrade the dye without producing organochloride compounds.

  20. Corrosion behavior of aluminum alloy 2024-T3 by 8-hydroxy-quinoline and its derivative in 3.5% chloride solution

    Institute of Scientific and Technical Information of China (English)

    LI Song-mei; ZHANG Hong-rui; LIU Jian-hua

    2007-01-01

    The corrosion behavior of aluminum alloy 2024-T3 was studied in 3.5% NaCl solution with two fluorescence quinoline compounds named 8-hydroxy-quinoline(8HQ) and 8-hydroxy-quinoline-5-sulfonic acid(HQS). The open circuit potential(OCP) test result indicates that both compounds change the alloy corrosion potential by adsorbing on the electrode surface. Polarization measurements show that 8HQ is a mixed type inhibitor by blocking the active sites of the metal surface, while HQS is a corrosion accelerator by activating the cathodic reaction. Changes of the impedance parameters in the electrochemical impedance spectroscopy(EIS) are related to the adsorption of 8HQ on the metal surface, which leads to the formation of a protective layer. The impedance diagram in the solution with HQS is similar to the one without additional organic compounds. The morphology and composition of the protective layer were studied by using SEM/EDS. The result confirms the function of the additions that the effect of 8HQ is due to the insoluble aluminum chelate, Al(HQ)3, to prevent adsorption of chloride ion, while the effect of HQS is to break down the oxide film.

  1. Pain and swelling after periapical surgery related to the hemostatic agent used: Anesthetic solution with vasoconstrictor or aluminum chloride

    Science.gov (United States)

    Maestre-Ferrín, Laura; Peñarrocha-Oltra, David; Gay-Escoda, Cosme; von-Arx, Tomas; Peñarrocha-Diago, Miguel

    2012-01-01

    Objective: To assess pain and swelling in the first 7 days after periapical surgery and their relationship with the agent used for bleeding control. Study Design: A prospective study was conducted between October 2006 and March 2009. Patients subjected to root surgery, who completed the questionnaire and who consented to the postoperative instructions were included in the study. The subjects were divided into two groups according to the hemostatic agent used: A) gauze impregnated with anesthetic solution with vasoconstrictor; or B) aluminum chloride. The patients were administered a questionnaire, and were asked to record the severity of their pain and swelling on a plain horizontal visual analog scale (VAS). Data were recorded by the patients on the first 7 postoperative days. In addition, the patients were asked to record analgesic consumption. Results: A total of 76 questionnaires (34 in group A and 42 in group B) were taken to be correctly completed. Pain was reported to be most intense two hours after surgery. At this point 52.6% of the patients had no pain. Seventy-five percent of the patients consumed analgesics in the first 24 hours. There were no significant differences between the two groups in terms of the intensity of pain or in the consumption of analgesics. Swelling reached its maximum peak on the second day; at this point, 60.6% of the patients suffered mild or moderate swelling. The Expasyl™ group showed significantly greater swelling than the gauzes group. Conclusion: The type of hemostatic agent used did not influence either the degree of pain or the need for analgesia among the patients in this study. However, the patients belonging to the Expasyl™ group suffered greater swelling than the patients treated with gauzes impregnated with anesthetic solution with vasoconstrictor. Key words:Hemostasis, periradicular surgery, aluminum chloride, pain, swelling. PMID:22322510

  2. Vacuum-jacketed hydrofluoric acid solution calorimeter

    Science.gov (United States)

    Robie, R.A.

    1965-01-01

    A vacuum-jacketed metal calorimeter for determining heats of solution in aqueous HF was constructed. The reaction vessel was made of copper and was heavily gold plated. The calorimeter has a cooling constant of 0.6 cal-deg -1-min-1, approximately 1/4 that of the air-jacketed calorimeters most commonly used with HF. It reaches equilibrium within 10 min after turning off the heater current. Measurements of the heat of solution of reagent grade KCl(-100 mesh dried 2 h at 200??C) at a mole ratio of 1 KCl to 200 H2O gave ??H = 4198??11 cal at 25??C. ?? 1965 The American Institute of Physics.

  3. Comments on the paper: 'Optical reflectance, optical refractive index and optical conductivity measurements of nonlinear optics for L-aspartic acid nickel chloride single crystal'

    Science.gov (United States)

    Srinivasan, Bikshandarkoil R.; Naik, Suvidha G.; Dhavskar, Kiran T.

    2016-02-01

    We argue that the 'L-aspartic acid nickel chloride' crystal reported by the authors of the title paper (Optics Communications, 291 (2013) 304-308) is actually the well-known diaqua(L-aspartato)nickel(II) hydrate crystal.

  4. Raman spectra of amino acids and their aqueous solutions

    Science.gov (United States)

    Zhu, Guangyong; Zhu, Xian; Fan, Qi; Wan, Xueliang

    2011-03-01

    Amino acids are the basic "building blocks" that combine to form proteins and play an important physiological role in all life-forms. Amino acids can be used as models for the examination of the importance of intermolecular bonding in life processes. Raman spectra serve to obtain information regarding molecular conformation, giving valuable insights into the topology of more complex molecules (peptides and proteins). In this paper, amino acids and their aqueous solution have been studied by Raman spectroscopy. Comparisons of certain values for these frequencies in amino acids and their aqueous solutions are given. Spectra of solids when compared to those of the solute in solution are invariably much more complex and almost always sharper. We present a collection of Raman spectra of 18 kinds of amino acids ( L-alanine, L-arginine, L-aspartic acid, cystine, L-glutamic acid, L-glycine, L-histidine, L-isoluecine, L-leucine, L-lysine, L-phenylalanine, L-methionone, L-proline, L-serine, L-threonine, L-tryptophan, L-tyrosine, L-valine) and their aqueous solutions that can serve as references for the interpretation of Raman spectra of proteins and biological materials.

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

    Science.gov (United States)

    Narumi, Akira; Kashiwagi, Takao; Nakane, Ichirou

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

  6. Acetic acid and lithium chloride effects on hydrothermal carbonization of lignocellulosic biomass.

    Science.gov (United States)

    Lynam, Joan G; Coronella, Charles J; Yan, Wei; Reza, Mohammad T; Vasquez, Victor R

    2011-05-01

    As a renewable non-food resource, lignocellulosic biomass has great potential as an energy source or feedstock for further conversion. However, challenges exist with supply logistics of this geographically scattered and perishable resource. Hydrothermal carbonization treats any kind of biomass in 200 to 260°C compressed water under an inert atmosphere to produce a hydrophobic solid of reduced mass and increased fuel value. A maximum in higher heating value (HHV) was found when 0.4 g of acetic acid was added per g of biomass. If 1g of LiCl and 0.4 g of acetic acid were added per g of biomass to the initial reaction solution, a 30% increase in HHV was found compared to the pretreatment with no additives, along with greater mass reduction. LiCl addition also reduces reaction pressure. Addition of acetic acid and/or LiCl to hydrothermal carbonization each contribute to increased HHV and reduced mass yield of the solid product. PMID:21411315

  7. Compatible solutes in lactic acid bacteria subjected to water stress.

    NARCIS (Netherlands)

    Kets, E.P.W.

    1997-01-01

    The goal of the research project described in this thesis was to investigate the protective effect of compatible solutes on tactic acid bacteria subjected to drying. Dried preparations of lactic acid bacteria are applied as starter cultures in feed and food industries. Dried starter cultures compare

  8. Rheological Behaviors of Polyacrylonitrile/1-Butyl-3- Methylimidazolium Chloride Concentrated Solutions

    Directory of Open Access Journals (Sweden)

    Mingfang Yu

    2007-03-01

    Full Text Available One of the room temperature ionic liquids (RTILs, 1-butyl-3-methylimidazoliumchloride ([BMIM]Cl was chosen to prepare the concentrated solutions of Polyacrylonitrile(PAN. The rheological behaviors of the solutions were measured with rotational rheometryunder different conditions, including temperatures, concentration, and molecular weight ofPAN. The solutions exhibited shear-thinning behaviors, similar to that of PAN/DMFsolutions. The viscosities decreased with the increasing of shear rates. However, theviscosity decreased sharply at high shear rates when the concentration was up to 16wt%. Thedependence of the viscosity on temperature was analyzed through the determination of theapparent activation energy. Unusually, the viscosity of solutions of higher concentration islower than that of lower concentration. Similarly, the viscosity of low molecular weightPAN was higher than high molecular weight PAN at high shear rates. The dynamicrheological measurement indicates the loss modulus is much higher than storage modulus.The trend of complex viscosity is similar with the result of static rheological measurement.The interaction between PAN and ionic liquid [BMIM]Cl was discussed.

  9. Radiolysis studies of uranyl nitrate solution in nitric acid medium

    International Nuclear Information System (INIS)

    The radiolysis of acidic uranyl nitrate solutions was investigated using Co-60 gamma radiation. Hydrogen peroxide was determined as a function of increasing dose. The UV-vis absorption spectra of the irradiated solutions were measured and the spectral changes were analyzed. The increasing dose increases the absorbance intensities, possibly by an increment in nitrate concentration produced by radiolysis, which can originate the formation of different uranyl complexes in solution. (author)

  10. Photolysis of Periodate and Periodic Acid in Aqueous Solution

    DEFF Research Database (Denmark)

    Sehested, Knud; Kläning, U. K.

    1978-01-01

    The photochemistry of periodate and periodic acid in aqueous solution was studied (i) by quantum yield measurements at low light intensity (ii) by flash photolysis, and (iii) by photolysis of glassy samples at 77 K. The photochemical studies were supplemented with pulse radiolysis studies...... of aqueous periodate solutions and with kinetic studies using stopped-flow technique. In strongly alkaline solution the photodecomposition of periodate proceeds via formation of O– and IVI. At pH

  11. Phosphorylation of glyceric acid in aqueous solution using trimetaphosphate.

    Science.gov (United States)

    Kolb, V; Orgel, L E

    1996-02-01

    The phosphorylation of glyceric acid is an interesting prebiotic reaction because it converts a simple, potentially prebiotic organic molecule into phosphate derivatives that are central to carbohydrate metabolism. We find that 0.05 M glyceric acid in the presence of 0.5 M trimetaphosphate in alkaline solution gives a mixture of 2- and 3-phosphoglyceric acids in combined yields of up to 40%. PMID:11536746

  12. Phosphorylation of Glyceric Acid in Aqueous Solution Using Trimetaphosphate

    Science.gov (United States)

    Kolb, Vera; Orgel, Leslie E.

    1996-01-01

    The phosphorylation of glyceric acid is an interesting prebiotic reaction because it converts a simple, potentially prebiotic organic molecule into phosphate derivatives that are central to carbohydrate metabolism. We find that 0.05 M glyceric acid in the presence of 0.5 M trimetaphosphate in alkaline solution gives a mixture of 2- and 3-phosphoglyceric acids in combined yields of up to 40%.

  13. Thermotropic liquid crystalline polyesters derived from bis-(4-hydroxybenzoyloxy)-2-methyl-1,4-benzene and aliphatic dicarboxylic acid chlorides

    Indian Academy of Sciences (India)

    Khudbudin Mulani; Mohasin Momin; Nitin Ganjave; Nayaku Chavan

    2015-09-01

    A series of thermotropic liquid crystalline polyesters derived from bis-(4-hydroxybenzoyloxy)-2-methyl-1,4-benzene (BHBOMB) and aliphatic dicarboxylic acid chlorides were investigated. All these polyesters were synthesized by interfacial polycondensation method and characterized by differential scanning calorimetry and wide-angle X-ray diffractometer. These polyesters consist of BHBOMB as a mesogenic diol and aliphatic diacid chlorides were used as flexible spacers. The length of oligomethylene units in polymer was varied from the trimethylene to the dodecamethylene groups. The transition temperatures and thermodynamic properties were studied for all these polymers. All these polyesters were soluble in chlorinated solvents such as chloroform, dichloromethane, dichloroethane, etc. More importantly, all these polyesters exhibited very large mesophase stability.

  14. Corrosion Fatigue Behavior of Duplex Stainless Steel in 3.5% Sodium Chloride Solution

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The corrosion fatigue behavior of duplex stainless steel (DSS) was studied at different cyclic stress levels in 3.5%NaCl (mass fraction, so as the follows) solution (pH=7) at 50℃. The results showed that DSS was susceptible to pitting corrosion and corrosion fatigue. Both intergranluar corrosion cracking and transgranlular corrosion cracking initiated at the bottom of pitting holes. Furthermore, the corrosion fatigue properties of DSS in 3.5%NaCl solution may be relatived to complex electrochemical and mechanical coupling effects between the three phases (austenite, ferrite and martensite), where martensite and ferrite were anodic in the corrosion cell and could be prone to cracking under certain condition.

  15. Inhibiting effect of acetonitrile on oxygen reduction on polycrystalline pt electrode in sodium chloride solution

    Directory of Open Access Journals (Sweden)

    Marinović Vedrana M.

    2012-01-01

    Full Text Available The oxygen reduction reaction (ORR was studied on the polycrystalline Pt electrode in 0.1 M NaCl electrolyte containing various amounts of acetonitrile (AcN. The state of the electrode surface was characterized by the cyclic voltammetry in oxygen free electrolytes, while ORR studies were performed on the polycrystalline Pt rotating disc electrode by the linear sweep voltammetry in oxygen saturated electrolytes. The acetonitrile is chemisorbed on Pt over a wide potential range, inhibiting both hydrogen adsorption and oxide formation. The extent of AcN chemisorption depends on its concentration in the solution. Initial potential of oxygen reduction is shifted negatively, while the ORR current is increasingly reduced with the increase of AcN concentration. Complete inhibition of ORR in the potential range of AcN and Cl-anion coadsorption is achieved for (0.1 M NaCl + 1 M AcN solution.

  16. Electrochemical characterisation of a martensitic stainless steel in a neutral chloride solution

    OpenAIRE

    Marcelin, Sabrina; Pébère, Nadine; Régnier, Sophie

    2013-01-01

    International audience; This paper focuses on the characterisation of the electrochemical behaviour of a martensitic stainless steel in 0.1 M NaCl + 0.04 M Na2SO4 solution and is a part of a study devoted to crevice corrosion resistance of stainless steels. Polarisation curves and electrochemical impedance measurements were obtained for different experimental conditions in bulk electrolyte. X-ray photoelectron spectroscopy (XPS) was used to analyse the passive films. At the corrosion potentia...

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

    OpenAIRE

    I. N. Shvarev; Andreev, S. S.; V. V. Savich

    2016-01-01

    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 c...

  18. Influence of Heat Treatment on the Corrosion of Microalloyed Steel in Sodium Chloride Solution

    OpenAIRE

    Asiful Hossain Seikh

    2013-01-01

    Microalloyed Steels find wide application in car bodies and other engineering parts because of its high strength as well as high ductility. Very fine grained microstructure is the reason behind the combination of strength and ductility. It has been reported that repeated quenching leads to further refining of microstructure. In the present investigation, corrosion resistance property of E34 microalloy steel has been studied in 3.5% NaCl solution in different microstructural conditions such as...

  19. Saturated sodium chloride solution under an external static electric field: A molecular dynamics study

    Science.gov (United States)

    Ren, Gan; Wang, Yan-Ting

    2015-12-01

    The behavior of saturated aqueous NaCl solutions under a constant external electric field (E) was studied by molecular dynamics (MD) simulation. Our dynamic MD simulations indicated that the irreversible nucleation process towards crystallization is accelerated by a moderate E but retarded or even prohibited under a stronger E, which can be understood by the competition between self-diffusion and drift motion. The former increases with E, thereby accelerating the nucleation process, whereas the latter pulls oppositely charged ions apart under a stronger E, thereby decelerating nucleation. Additionally, our steady-state MD simulations indicated that a first-order phase transition occurs in saturated solutions at a certain threshold Ec. The magnitude of Ec increases with concentration because larger clusters form more easily when the solution is more concentrated and require a stronger E to dissociate. Project supported by the National Basic Research Program of China (Grant No. 2013CB932804) and the National Natural Science Foundation of China (Grant Nos. 91227115, 11274319, and 11421063).

  20. Solvent extraction of vanadium from sulfuric acid solution

    Institute of Scientific and Technical Information of China (English)

    WANG Mingyu; ZHANG Guiqing; WANG Xuewen; ZHANG Jialiang

    2009-01-01

    The behaviour of vanadium(V) extracted from sulfuric acid solution was investigated using Cyanex 923 as an cxtractant. The effects of the concentration of Cyanex 923 and the pH of the solution were studied. The extraction of vanadium(V) increases with the increase of Cyanex 923 concentration and shaking time. Cyanex 923 can extract vanadium(V) fi'om sulfuric acid solution at low pH conditions, and the best pH conditions for exuaction of vanadium(V) are at pH 1.0-2.0. The species extracted into the organic phase is VO2HSO4 with one molecule of Cyanex 923. Equilibrium studies were used to assess the extraction efficiency of vanadium(V) recovery from the sulfuric acid solution.

  1. Study of benzotriazole as corrosion inhibitors of carbon steel in chloride solution containing hydrogen sulfide using electrochemical impedance spectroscopy (EIS)

    International Nuclear Information System (INIS)

    Corrosion and inhibition studies on API 5LX65 carbon steel in chloride solution containing various concentrations of benzotriazole has been conducted at temperature of 70°C using Electrochemical Impedance Spectroscopy (EIS). Corroded carbon steel surface with and without inhibitor have been observed using X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Energy Dispersive Spectroscopy (EDS). The objectives of this research are to study the performance of benzotriazole as corrosion inhibitors. The experimental results of carbon steel corrosion in 3.5% NaCl solution containing 500 mg/l H2S at different BTAH concentrations showed that corrosion rate of carbon steel decreases with increasing of BTAH concentrations from 0 to 10 mmol/l. The inhibition efficiency of BTAH was found to be affected by its concentration. The optimum efficiency obtained of BTAH is 93% at concentration of 5 mmol/l. The result of XRD and EDS analysis reveal the iron sulfide (FeS) formation on corroded carbon steel surface without inhibitor. The EDS spectrum show the Nitrogen (N) bond on carbon steel surface inhibited by BTAH

  2. Study of benzotriazole as corrosion inhibitors of carbon steel in chloride solution containing hydrogen sulfide using electrochemical impedance spectroscopy (EIS)

    Energy Technology Data Exchange (ETDEWEB)

    Solehudin, Agus, E-mail: asolehudin@upi.edu [Department of Mechanical Engineering Education, Indonesia University of Education (UPI), Bandung, West Java (Indonesia); Nurdin, Isdiriayani [Department of Chemical Engineering, Bandung Institute of Technology, Bandung, West Java (Indonesia)

    2014-03-24

    Corrosion and inhibition studies on API 5LX65 carbon steel in chloride solution containing various concentrations of benzotriazole has been conducted at temperature of 70°C using Electrochemical Impedance Spectroscopy (EIS). Corroded carbon steel surface with and without inhibitor have been observed using X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Energy Dispersive Spectroscopy (EDS). The objectives of this research are to study the performance of benzotriazole as corrosion inhibitors. The experimental results of carbon steel corrosion in 3.5% NaCl solution containing 500 mg/l H{sub 2}S at different BTAH concentrations showed that corrosion rate of carbon steel decreases with increasing of BTAH concentrations from 0 to 10 mmol/l. The inhibition efficiency of BTAH was found to be affected by its concentration. The optimum efficiency obtained of BTAH is 93% at concentration of 5 mmol/l. The result of XRD and EDS analysis reveal the iron sulfide (FeS) formation on corroded carbon steel surface without inhibitor. The EDS spectrum show the Nitrogen (N) bond on carbon steel surface inhibited by BTAH.

  3. Study of benzotriazole as corrosion inhibitors of carbon steel in chloride solution containing hydrogen sulfide using electrochemical impedance spectroscopy (EIS)

    Science.gov (United States)

    Solehudin, Agus; Nurdin, Isdiriayani

    2014-03-01

    Corrosion and inhibition studies on API 5LX65 carbon steel in chloride solution containing various concentrations of benzotriazole has been conducted at temperature of 70°C using Electrochemical Impedance Spectroscopy (EIS). Corroded carbon steel surface with and without inhibitor have been observed using X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Energy Dispersive Spectroscopy (EDS). The objectives of this research are to study the performance of benzotriazole as corrosion inhibitors. The experimental results of carbon steel corrosion in 3.5% NaCl solution containing 500 mg/l H2S at different BTAH concentrations showed that corrosion rate of carbon steel decreases with increasing of BTAH concentrations from 0 to 10 mmol/l. The inhibition efficiency of BTAH was found to be affected by its concentration. The optimum efficiency obtained of BTAH is 93% at concentration of 5 mmol/l. The result of XRD and EDS analysis reveal the iron sulfide (FeS) formation on corroded carbon steel surface without inhibitor. The EDS spectrum show the Nitrogen (N) bond on carbon steel surface inhibited by BTAH.

  4. 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

  5. Self-consistent field theory investigation of the behavior of hyaluronic acid chains in aqueous salt solutions

    Science.gov (United States)

    Nogovitsin, E. A.; Budkov, Yu. A.

    2012-04-01

    In this work we continue to develop a field-theoretic methodology, which combines the technique of Gaussian equivalent representation for the calculation of functional integrals with the continuous Gaussian thread model of flexible polymers for solving statistical-mechanical problems of polyelectrolyte solutions. We present new analytic expressions for the osmotic pressure, the potential of mean force, and the monomer-monomer pair distribution function, and employ them to investigate the structural and thermodynamic quantities of the polyelectrolyte system. We demonstrate the applicability of the method for systems of polyelectrolyte chains in which the monomers interact via a Yukawa-type pair potential. As a specific example, the present work focuses on aqueous solutions of hyaluronic acid with added salts NaCl and CaCl2. Hyaluronic acid is a high molecular weight linear polysaccharide, which has a multitude of roles in biological tissues. We conclude that the effect of sodium chloride and calcium chloride on the osmotic properties of hyaluronic acid solutions can be accounted for by their contributions to the ionic strength. Nevertheless, the effects of coiling and self-association can be stimulated in solution by added salt.

  6. Response surface optimization of acid red 119 dye from simulated wastewater using Al based waterworks sludge and polyaluminium chloride as coagulant.

    Science.gov (United States)

    Moghaddam, S Sadri; Moghaddam, M R Alavi; Arami, M

    2011-04-01

    In this research, the performance of Polyaluminium Chloride (PAC) and Polyaluminium Chloride sludge (PACS) as coagulants for acid red 119 (AR119) dye removal from aqueous solutions were compared. The sample of PACS was collected from "Baba Sheikh Ali" water treatment plant (Isfahan, Iran) where PAC is used as a coagulant in the coagulation/flocculation process. A response surface methodology was applied to evaluate the simple and combined effects of the operating variables including initial pH, coagulant dosage and initial dye concentration and to optimize the operating conditions of the treatment process. Results reveal that the optimal conditions for dye removal were initial pH 3.42, coagulant dosage of 4.55 g dried PACS/L and initial dye concentration of 140 mg/L for PACS, while the optimal initial pH, coagulant dosage and initial dye concentration for PAC were 3.8, 57 mg/L and 140 mg/L, respectively. Under these optimal values of process parameters, the dye removal efficiency of 94.1% and 95.25% was observed for PACS and PAC, respectively. Although lower amount of PAC in comparison with PACS was needed for specific dye removal, the reuse of PACS as a low-cost material can offer some advantages such as high efficiency for AR119 dye removal and economic savings on overall water and wastewater treatment plant operation costs. PMID:21216522

  7. Inhibitive effect of some thiadiazole derivatives on C-steel corrosion in neutral sodium chloride solution

    Energy Technology Data Exchange (ETDEWEB)

    El-Taib Heakal, F., E-mail: fakihaheakal@yahoo.com [Chemistry Department, Faculty of Science, Cairo University, Giza 12613 (Egypt); Fouda, A.S. [Chemistry Department, Faculty of Science, El-Mansoura University, El-Mansoura (Egypt); Radwan, M.S. [Petrogulf Misr Company, Maadi, Cairo (Egypt)

    2011-01-01

    Electrochemical techniques were used to investigate the effect of concentration of three new thiadiazole derivatives (I-III) on the corrosion behavior of C-steel in 0.5 M NaCl solution through the analysis of electrochemical measurements including open circuit potential (OCP), Tafel polarization and electrochemical impedance spectroscopy (EIS). Polarization curves showed that the compounds studied act as anodic type inhibitors, where the inhibition efficiency increases with increase in inhibitor concentration and decreases with rise in temperature. An adherent layer of inhibitor molecules on the surface is proposed to account for their inhibitive action in which the organic molecules adsorb on the active anodic sites following Langmuir isotherm. The thermodynamic parameters of adsorption and corrosion processes were determined and discussed. The results also indicated that pitting potential at higher anodic polarization of C-steel in 0.5 M NaCl solution becomes more positive the higher the concentration of the additive, suggesting that these inhibitors acts as retarding catalyst for pitting corrosion. EIS data confirm well the electrochemical dc results and the results are all in good agreement with the calculated quantum chemical HOMO and LUMO energies of the tested molecules, as well as with surface examination via scanning electron microscope.

  8. Self-sustained thin webs consisting of porous carbon nanofibers for supercapacitors via the electrospinning of polyacrylonitrile solutions containing zinc chloride

    Energy Technology Data Exchange (ETDEWEB)

    Kim, C.; Ngoc, B.T.N.; Yang, K.S. [Center for Functional Nano Fine Chemicals, Chonnam National University, 300 Yong-bond dong, Buk-gu, Gwangju 500-757 (Korea); Kojima, M.; Kim, Y.A.; Kim, Y.J.; Endo, M. [Faculty of Engineering, Shinshu University, 4-17-1 Wakasato, Nagano-shi 380-8553 (Japan); Yang, S.C. [AMOTECH Co., Ltd, 597-2 Wonsanri, Hasungmyun, Gimpo, Gyunggido (Korea)

    2007-09-03

    We present a simple strategy for the fabrication of porous carbon nanofibers (see figure). This procedure produces thin webs by electrospinning a polymer solution containing different concentrations of zinc chloride and subsequently thermally treating the system. Their resulting surface area and good electrical conductivity make these porous carbon nanofibers useful in the fabrication of efficient electrodes for supercapacitors. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  9. Effect of phytic acid, ethylenediaminetetraacetic acid, and chitosan solutions on microhardness of the human radicular dentin

    OpenAIRE

    Vineeta Nikhil; Shikha Jaiswal; Parul Bansal; Rohit Arora; Shalya Raj; Pulkit Malhotra

    2016-01-01

    Aim: The purpose of this study was to evaluate the effect of phytic acid, ethylenediaminetetraacetic acid (EDTA), and chitosan solutions on the microhardness of human radicular dentin. Materials and Methods: Thirty dentin specimens were randomly divided into three groups of 10 specimens each according to the irrigant used: G1 - 1% phytic acid, G2 - 17% EDTA, and G3 - 0.2% chitosan. A standardized volume of each chelating solution was used for 3 min. Dentin microhardness was measured befo...

  10. Study of Removal Nitrous Acid From Nitric Acid Solution Using Packed Column

    Institute of Scientific and Technical Information of China (English)

    LAN; Tian; CHANG; Shang-wen; LIU; Jin-ping; ZHOU; Xian-ming; LI; Gao-liang; TANG; Hong-bin; HE; Hui

    2013-01-01

    It is necessary that the adjustment of the Pu(Ⅲ)to Pu(Ⅳ)should be used excess nitride gases befor the cycle of Pu purification in Purex.The mass of nitrous acid were present in solution after adjustment.Ifthe solution contain the mass of nitrous acid arrived at the cycle of Pupurification,the nitrous could react with Pu reducing agent in the processof Pu back-extractionbecause nitrous acid could extracted to organic,

  11. Corrosion Behavior of Stainless Steels in Neutral and Acidified Sodium Chloride Solutions by Electrochemical Impedance Spectroscopy

    Science.gov (United States)

    Calle, L. M.; Kolady, M. R.; Vinje, R. D.

    2004-01-01

    The objective of this work was to evaluate the corrosion performance of three alloys by Electrochemical Impedance Spectroscopy (EIS) and to compare the results with those obtained during a two-year atmospheric exposure study.' Three alloys: AL6XN (UNS N08367), 254SM0 (UNS S32154), and 304L (UNS S30403) were included in the study. 304L was included as a control. The alloys were tested in three electrolyte solutions which consisted of neutral 3.55% NaC1, 3.55% NaC1 in 0.lN HC1, and 3.55% NaC1 in 1.ON HC1. These conditions were expected to be less severe, similar, and more severe respectively than the conditions at NASA's Kennedy Space Center launch pads.

  12. Influence of Heat Treatment on the Corrosion of Microalloyed Steel in Sodium Chloride Solution

    Directory of Open Access Journals (Sweden)

    Asiful Hossain Seikh

    2013-01-01

    Full Text Available Microalloyed Steels find wide application in car bodies and other engineering parts because of its high strength as well as high ductility. Very fine grained microstructure is the reason behind the combination of strength and ductility. It has been reported that repeated quenching leads to further refining of microstructure. In the present investigation, corrosion resistance property of E34 microalloy steel has been studied in 3.5% NaCl solution in different microstructural conditions such as the as rolled one and three repeated quenched conditions. Weight loss, potentiodynamic polarization method, and electrochemical impedance spectroscopy (EIS techniques have been used. To reveal the corrosion resistance of different treated steels, some significant characterization parameters such as Ecorr, Icorr, Rp, and Rct in linear polarization and EIS curves were analyzed and compared. It is found that with repeated recrystallization grains become finer, and corrosion rate increases suggesting that a compromise has to strike between high mechanical property and corrosion rate.

  13. Calcium Chloride in Neonatal Parenteral Nutrition Solutions with and without Added Cysteine: Compatibility Studies Using Laser and Micro-Flow Imaging Methodology

    OpenAIRE

    Robert K Huston; J Mark Christensen; Alshahrani, Sultan M.; Sumeia M Mohamed; Sara M Clark; Nason, Jeffrey A; Ying Xing Wu

    2015-01-01

    Background Previous studies of compatibility of calcium chloride (CaCl2) and phosphates have not included particle counts in the range specified by the United States Pharmacopeia. Micro-flow imaging techniques have been shown to be comparable to light obscuration when determining particle count and size in pharmaceutical solutions. Objective The purpose of this study was to do compatibility testing for parenteral nutrition (PN) solutions containing CaCl2 using dynamic light scattering and mic...

  14. Dephosphorization of Steelmaking Slag by Leaching with Acidic Aqueous Solution

    Science.gov (United States)

    Qiao, Yong; Diao, Jiang; Liu, Xuan; Li, Xiaosa; Zhang, Tao; Xie, Bing

    2016-09-01

    In the present paper, dephosphorization of steelmaking slag by leaching with acidic aqueous solution composed of citric acid, sodium hydroxide, hydrochloric acid and ion-exchanged water was investigated. The buffer solution of C6H8O7-NaOH-HCl system prevented changes in the pH values. Kinetic parameters including leaching temperature, slag particle size and pH values of the solution were optimized. The results showed that temperature has no obvious effect on the dissolution ratio of phosphorus. However, it has a significant effect on the dissolution ratio of iron. The dephosphorization rate increases with the decrease of slag particle size and the pH value of the solution. Over 90% of the phosphorus can be dissolved in the solution while the corresponding leaching ratio of iron was only 30% below the optimal condition. Leaching kinetics of dephosphorization follow the unreacted shrinking core model with a rate controlled step by the solid diffusion layer, the corresponding apparent activation energy being 1.233 kJ mol-1. A semiempirical kinetic equation was established. After leaching, most of the nC2S-C3P solid solution in the steelmaking slag was selectively dissolved in the aqueous solution and the iron content in the solid residue was correspondingly enriched.

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

    Directory of Open Access Journals (Sweden)

    Amer, S.

    1995-12-01

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

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

  16. Passivation Characteristics of Alloy Corrosion-Resistant Steel Cr10Mo1 in Simulating Concrete Pore Solutions: Combination Effects of pH and Chloride

    Directory of Open Access Journals (Sweden)

    Zhiyong Ai

    2016-09-01

    Full Text Available The electrochemical behaviour for passivation of new alloy corrosion-resistant steel Cr10Mo1 immersed in alkaline solutions with different pH values (13.3, 12.0, 10.5, and 9.0 and chloride contents (0.2 M and 1.0 M, was investigated by various electrochemical techniques: linear polarization resistance, electrochemical impedance spectroscopy and capacitance measurements. The chemical composition and structure of passive films were determined by XPS. The morphological features and surface composition of the immersed steel were evaluated by SEM together with EDS chemical analysis. The results evidence that pH plays an important role in the passivation of the corrosion-resistant steel and the effect is highly dependent upon the chloride contents. In solutions with low chloride (0.2 M, the corrosion-resistant steel has notably enhanced passivity with pH falling from 13.3 to 9.0, but does conversely when in presence of high chloride (1.0 M. The passive film on the corrosion-resistant steel presents a bilayer structure: an outer layer enriched in Fe oxides and hydroxides, and an inner layer, rich in Cr species. The film composition varies with pH values and chloride contents. As the pH drops, more Cr oxides are enriched in the film while Fe oxides gradually decompose. Increasing chloride promotes Cr oxides and Fe oxides to transform into their hydroxides with little protection, and this is more significant at lower pH (10.5 and 9.0. These changes annotate passivation characteristics of the corrosion-resistant steel in the solutions of different electrolyte.

  17. 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

  18. Oxidative desulfurization of askale coal by nitric acid solution

    Energy Technology Data Exchange (ETDEWEB)

    Guru, M. [Gazi University, Ankara (Turkey). Dept. of Chemical Engineering

    2007-07-01

    Efficient use of fossil fuels is of utmost importance in a world that depends on these for the greatest part of its energy needs. Although lignite is a widely used fossil fuel, its sulfur content limits its consumption. This study aims to capture combustible sulfur in the ash by oxidizing it with solution of nitric acid solution. Thus, the combustible sulfur in the coal was converted to sulfate form in the ash. Parameters affecting the conversion of sulfur were determined to be nitric acid concentration, reaction time and mean particle size at constant (near room) temperature and shaking rate. The maximum desulfurization efficiency reached was 38.7% of the original combustible sulfur with 0.3 M nitric acid solution, 16 h of reaction time and 0.1 mm mean particle size.

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

    Institute of Scientific and Technical Information of China (English)

    Reyhaneh Safarbali; Mohammad Reza Yaftian; Abbasali Zamani

    2016-01-01

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

  20. γ-Irradiation of malic acid in aqueous solutions

    Science.gov (United States)

    Negron-Mendoza, Alicia; Graff, Rebecca L.; Ponnamperuma, Cyril

    1980-12-01

    The γ-irradiation of malic acid in aqueous solutions was studied under initially oxygenated and oxygen-free conditions in an attempt to determine the possible interconversion of malic acid into other carboxylic acids, specifically those associated with Krebs cycle. The effect of dose on product formation of the system was investigated. Gas-liquid chromatography combined with mass spectrometry was used as the principal means of identification of the non-volatile products. Thin layer chromotography and direct probe mass spectroscopy were also employed. The findings show that a variety of carboxylic acids are formed, with malonic and succinic acids in greatest abundance. These products have all been identified as being formed in the γ-irradiation of acetic acid, suggesting a common intermediary. Since these molecules fit into a metabolic cycle, it is strongly suggestive that prebiotic pathways provided the basis for biological systems.

  1. Gamma-irradiation of malic acid in aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Negron-Mendoza, A.; Graff, R.L.; Ponnamperuma, C.

    1980-12-01

    The gamma-irradiation of malic acid in aqueous solutions was studied under initially oxygenated and oxygen-free conditions in an attempt to determine the possible interconversion of malic acid into other carboxylic acids, specifically those associated with Krebs cycle. The effect of dose on product formation of the system was investigated. Gas-liquid chromatography combined with mass spectrometry was used as the principal means of identification of the nonvolatile products. Thin layer chromatography and direct probe mass spectroscopy were also employed. The findings show that a variety of carboxylic acids are formed, with malonic and succinic acids in greatest abundance. These products have all been identified as being formed in the gamma-irradiation of acetic acid, suggesting a common intermediary. Since these molecules fit into a metabolic cycle, it is strongly suggestive that prebiotic pathways provided the basis for biological systems.

  2. The chloride-channel blocker 9-anthracenecarboxylic acid reduces the nonlinear capacitance of prestin-associated charge movement.

    Science.gov (United States)

    Harasztosi, Csaba; Gummer, Anthony W

    2016-04-01

    The basis of the extraordinary sensitivity and frequency selectivity of the cochlea is a chloride-sensitive protein called prestin which can produce an electromechanical response and which resides in the basolateral plasma membrane of outer hair cells (OHCs). The compound 9-anthracenecarboxylic acid (9-AC), an inhibitor of chloride channels, has been found to reduce the electromechanical response of the cochlea and the OHC mechanical impedance. To elucidate these 9-AC effects, the functional electromechanical status of prestin was assayed by measuring the nonlinear capacitance of OHCs from the guinea-pig cochlea and of prestin-transfected human embryonic kidney 293 (HEK 293) cells. Extracellular application of 9-AC caused reversible, dose-dependent and chloride-sensitive reduction in OHC nonlinear charge transfer, Qmax . Prestin-transfected cells also showed reversible reduction in Qmax . For OHCs, intracellular 9-AC application as well as reduced intracellular pH had no detectable effect on the reduction in Qmax by extracellularly applied 9-AC. In the prestin-transfected cells, cytosolic application of 9-AC approximately halved the blocking efficacy of extracellularly applied 9-AC. OHC inside-out patches presented the whole-cell blocking characteristics. Disruption of the cytoskeleton by preventing actin polymerization with latrunculin A or by decoupling of spectrin from actin with diamide did not affect the 9-AC-evoked reduction in Qmax . We conclude that 9-AC acts on the electromechanical transducer principally by interaction with prestin rather than acting via the cytoskeleton, chloride channels or pH. The 9-AC block presents characteristics in common with salicylate, but is almost an order of magnitude faster. 9-AC provides a new tool for elucidating the molecular dynamics of prestin function. PMID:26869218

  3. Corrosion Resistance and Pitting Behaviour of Low-Carbon High-Mn Steels in Chloride Solution

    Directory of Open Access Journals (Sweden)

    Grajcar A.

    2016-06-01

    Full Text Available Corrosion resistance of the X4MnSiAlNbTi27-4-2 and X6MnSiAlNbTi26-3-3 type austenitic steels, after hot deformation as well as after cold rolling, were evaluated in 3.5% NaCl solution using potentiodynamic polarization tests. A type of nonmetallic inclusions and their pitting corrosion behaviour were investigated. Additionally, the effect of cold deformation on the corrosion resistance of high-Mn steels was studied. The SEM micrographs revealed that corrosion damage formed in both investigated steels is characterized by various shapes and an irregular distribution at the metallic matrix, independently on the steel state (thermomechanically treated or cold worked. Corrosion pits are generated both in grain interiors, grain boundaries and along the deformation bands. Moreover, corrosion damage is stronger in cold deformed steels in comparison to the thermomechanically treated specimens. EDS analysis revealed that corrosion pits preferentially nucleated on MnS and AlN inclusions or complex oxysulphides. The morphology of corrosion damage in 3.5% NaCl supports the data registered in potentiodynamic tests.

  4. Critical pitting and repassivation temperatures for duplex stainless steel in chloride solutions

    Energy Technology Data Exchange (ETDEWEB)

    Deng Bo; Jiang Yiming; Gong Jia; Zhong Cheng; Gao Juan [Department of Material Science, Fudan University, Shanghai 200433 (China); Li Jin [Department of Material Science, Fudan University, Shanghai 200433 (China)], E-mail: jinli@fudan.edu.cn

    2008-06-30

    Both the critical pitting temperature (CPT) and critical repassivation temperature (T{sub r}) for two kinds of duplex stainless steels (DSS, namely UNS S31803 and UNS S32750) were investigated in 1 mol/L NaCl solution using the cyclic thermammetry method. Potentiodynamic anodic polarization technique was employed to validate the cyclic thermammetry technique. In addition, the site of pitting nucleated preferentially on the DSS had been confirmed by scanning electron microscopy (SEM). The results demonstrated that there exhibits a hysteresis loop in cyclic thermammetry curve, revealing that the propagating pits could repassivate during the cooling half-cycle. The CPT and T{sub r} for UNS S31803 were 59.6 deg. C and 36.5 deg. C, whilst the CPT and T{sub r} for UNS S32750 were 87.5 deg. C and 70.5 deg. C, respectively. Pitting was always observed preferentially in the austenite phase. The results can be partially explained based on the changes in chemical composition of ferrite and austenite phases. Moreover, a semi-quantitative model is proposed to explain the existence of T{sub r}.

  5. Hydrate film growth at the interface between gaseous CO2 and sodium chloride solution

    Institute of Scientific and Technical Information of China (English)

    PENG BaoZi; SUN ChangYu; CHEN GuangJin; YANG LanYing; ZHOU Wei; PANG WeiXin

    2009-01-01

    Greenhouse gas CO2 has become a serious problem for human beings. The hydrate technology has been considered as a possible approach to sequester CO2. In this work, the lateral growth rates of a CO2 hydrate film in aqueous NaCl solutions of different concentrations were measured by means of suspending a single gas bubble in liquid. The results show that the film growth rates depended on not only the driving force, but also the NaCl concentration, and the film growth rates decreased with the increasing NaCl concentration. The simple relationship vf∝△T6/2 could be used to correlate the hydrate film growth rate of a CO2 + NaCl + water system by introducing a NaCl concentration-dependent coef-ficient. The film thickness was investigated experimentally and evaluated theoretically; the results show that it became thicker at a higher NaCl concentration when the temperature and pressure were specified. In addition, a series of interesting phenomena, such as the occurrence of double hydrate films, were displayed and discussed.

  6. Hydrate film growth at the interface between gaseous CO2 and sodium chloride solution

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Greenhouse gas CO2 has become a serious problem for human beings. The hydrate technology has been considered as a possible approach to sequester CO2. In this work, the lateral growth rates of a CO2 hydrate film in aqueous NaCl solutions of different concentrations were measured by means of suspending a single gas bubble in liquid. The results show that the film growth rates depended on not only the driving force, but also the NaCl concentration, and the film growth rates decreased with the increasing NaCl concentration. The simple relationship vf ∝ΔT5/2 could be used to correlate the hydrate film growth rate of a CO2 + NaCl + water system by introducing a NaCl concentration-dependent coefficient. The film thickness was investigated experimentally and evaluated theoretically; the results show that it became thicker at a higher NaCl concentration when the temperature and pressure were specified. In addition, a series of interesting phenomena, such as the occurrence of double hydrate films, were displayed and discussed.

  7. Combined effects of simulated acid rain and lanthanum chloride on chloroplast structure and functional elements in rice.

    Science.gov (United States)

    Hu, Huiqing; Wang, Lihong; Zhou, Qing; Huang, Xiaohua

    2016-05-01

    Acid rain and rare earth element (REE) pollution exist simultaneously in many agricultural regions. However, how REE pollution and acid rain affect plant growth in combination remains largely unknown. In this study, the combined effects of simulated acid rain and lanthanum chloride (LaCl3) on chloroplast morphology, chloroplast ultrastructure, functional element contents, chlorophyll content, and the net photosynthetic rate (P n) in rice (Oryza sativa) were investigated by simulating acid rain and rare earth pollution. Under the combined treatment of simulated acid rain at pH 4.5 and 0.08 mM LaCl3, the chloroplast membrane was smooth, proteins on this membrane were uniform, chloroplast structure was integrated, and the thylakoids were orderly arranged, and simulated acid rain and LaCl3 exhibited a mild antagonistic effect; the Mg, Ca, Mn contents, the chlorophyll content, and the P n increased under this combined treatment, with a synergistic effect of simulated acid rain and LaCl3. Under other combined treatments of simulated acid rain and LaCl3, the chloroplast membrane surface was uneven, a clear "hole" was observed on the surface of chloroplasts, and the thylakoids were dissolved and loose; and the P n and contents of functional elements (P, Mg, K, Ca, Mn, Fe, Ni, Cu, Zn and Mo) and chlorophyll decreased. Under these combined treatments, simulated acid rain and LaCl3 exhibited a synergistic effect. Based on the above results, a model of the combined effects of simulated acid rain and LaCl3 on plant photosynthesis was established in order to reveal the combined effects on plant photosynthesis, especially on the photosynthetic organelle-chloroplast. Our results would provide some references for further understanding the mechanism of the combined effects of simulated acid rain and LaCl3 on plant photosynthesis. PMID:26815371

  8. The effect of initial tonicity on freeze/thaw injury to human red cells suspended in solutions of sodium chloride.

    Science.gov (United States)

    Pegg, D E; Diaper, M P

    1991-02-01

    Human red blood cells, suspended in solutions of sodium chloride, have been frozen to temperatures between -2 and -14 degrees C and thawed, and the extent of hemolysis was measured. In parallel experiments, red cells were exposed to similar cycles of change in the composition of the suspending solution, but by dialysis at 21 degrees C. The tonicity of the saline in which the cells were initially suspended was varied between 0.6x isotonic and 4x isotonic; some samples from each experimental treatment were returned to isotonic saline before hemolysis was measured. It was found that the tonicity of the saline used to suspend the cells for the main body of the experiment affected the amount of hemolysis measured: raising the tonicity from 0.6x to 1x to 2x reduced hemolysis, both in the freezing and in the dialysis experiments, whereas raising the tonicity further to 4x reversed that trend. There was little difference between the freeze/thaw and the dialysis treatments for the cells suspended in 1x or 2x saline, whether or not the cells were returned to isotonic conditions. However, the cells suspended in 0.6x saline showed greater damage from freezing and thawing than from the comparable change in the composition of the solution, whether or not they were returned to isotonic conditions. Cells that were suspended in 4x saline and exposed to changes in salt concentration by dialysis showed less hemolysis when they were assayed in the 4x solution than cells that had received the comparable freezing/thaw treatment, but when the experiment included a return to isotonicity, the two treatments gave similar results. Returning the cells to isotonic saline had a negligible affect on the cells in 0.6x and 1x saline, but caused considerable hemolysis in the 2x and 4x samples, more so after dialysis than after freezing and thawing. We conclude that cells suspended in 0.6x and 4x saline behave differently from cells suspended in 1x and 2x saline and hence that cells suspended in a

  9. Electrochemical behaviour of brass in chloride solution concentrations found in eccrine fingerprint sweat

    Energy Technology Data Exchange (ETDEWEB)

    Bond, John W., E-mail: jwb13@le.ac.uk [Department of Chemistry, George Porter Building, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom); Lieu, Elaine [Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom)

    2014-09-15

    Highlights: • Corrosion of brass in NaCl concentrations found in eccrine sweat was investigated. • Concentrations < 0.2 M produce a layer of mainly zinc oxide after 24 h. • A concentration of 0.2 M enables active corrosion of brass at room temperature. • 0.2 M NaCl gives both zinc and copper dissolution. • 24-h immersion of brass in 0.2 M NaCl gives an oxide film thickness of 1.3 nm. - Abstract: In this work, the corrosion properties of α phase brass immersed in concentrations of aqueous NaCl solutions that are typically found in eccrine fingerprint sweat and range between 0.01 M and 0.2 M have been analysed. Analysis methods employed were electrochemical techniques, X-ray photoelectron spectroscopy and optical profiling. For NaCl concentrations <0.2 M, active corrosion did not occur although, after a period of 24 h, a passivating layer of mainly zinc oxide formed. At a concentration of 0.2 M active corrosion did occur, with measured corrosion potentials consistent with both brass and copper dissolution. A 1 h contact time at this concentration (0.2 M) resulted in the formation of a zinc oxide passivating layer with the surface ratio of zinc oxide to copper oxide increasing with time. Film thickness was calculated to be of the order of 1.3 nm after 24 h contact. Formation of oxide layers on brass by fingerprint sweat as observed here may well have implications for the successful investigation of crime by the visualisation of corrosion fingerprint ridge patterns or the reduction of hospital environmental contamination by hand contact with brass objects such as door handles or taps.

  10. Recovery of Co(Ⅱ) and Ni(Ⅱ) from hydrochloric acid solution of alloy scrap

    Institute of Scientific and Technical Information of China (English)

    SHEN Yong-feng; XUE Wen-ying; NIU Wen-yong

    2008-01-01

    A hydrometallurgical process was developed for recovery of nickel and cobalt from the hydrochloric acid leaching solution of alloy scraps. The process consists of five major unit operations: 1) leaching with 6 mol/L hydrochloric acid under the L/S ratio of 10:1 at 95 ℃ for 3 h; 2) copper replacement by iron scraps under pH value of 2.0 at 80 ℃, and stirring for 1 h; 3) removal of iron and chromium by chemical precipitation: iron removal under pH value of 2.0 at 90 ℃ by dropwise addition of sodium chlorate and 18% sodium carbonate solution, then chromium removal under pH value of 4.0 at 70 ℃ by addition of nickel carbonate solution, stirred by air flow for 2 h; 4) selective separation of cobalt from nickel by extraction using 30% trialkyl amine+50% kerosene (volume fraction) and tri-n-butylphosphate (TBP) as a phase modifier with the O/A ratio of 2:1, and stripping of cobalt with 0.01 mol/L HC1; 5) crystallization of nickel chloride and electrodeposition of cobalt. It is found that the nickel recovery of 95% and the cobalt recovery of approximately 60% with purity over 99.9% are obtained by this process.

  11. Comparison of the corrosion behavior and surface morphology of NiTi alloy and stainless steels in sodium chloride solution

    Directory of Open Access Journals (Sweden)

    Kožuh S.

    2016-01-01

    Full Text Available The corrosion behavior of NiTi alloy and stainless steels (AISI 316L and X2CrNiMoN22-5-3 in 0.9% sodium chloride (0.154 moll-1 solution was investigated using open circuit potential measurements, potentiodynamic polarization and electrochemical impedance spectroscopy measurements. Microstructural analyses before and after electrochemical tests were performed with the scanning electron microscopy (SEM equipped with energy dispersive spectrometry (EDS. The lowest corrosion current density has NiTi alloy and the extent of the passive range increased in the order AISI 316L stainless steel < NiTi alloy < X2CrNiMoN22-5-3 duplex stainless steel. The oxide film formed on all samples has a double-layer structure consisting of a barrier-type inner layer and a porous outer layer. Oxide films formed on the surface of steels mainly contains iron oxides and chromium oxide, while the surface film of the NiTi alloy mainly contains TiO2 oxide.

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

    Science.gov (United States)

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

    2016-04-01

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

  13. Stability of succinylcholine chloride injection.

    Science.gov (United States)

    Schmutz, C W; Mühlebach, S F

    1991-03-01

    The stability of succinylcholine chloride injection prepared by a hospital pharmacy was studied under a wide variety of conditions. Batches of succinylcholine chloride injection 10 mg/mL containing sodium chloride, methyl-4-hydroxybenzoate, hydrochloric acid, and water were prepared. Samples were tested for the effect of initial pH (3.0 and 4.2) and sterilization (steam treatment at 100 degrees C for 30 minutes and 121 degrees C for 20 minutes) on stability after three weeks; long-term stability under refrigeration (12, 17, and 23 months of storage at 4 degrees C); and the effect of storage temperature (4-6 degrees C, 20-26 degrees C, 35 degrees C, and 70 degrees C) and light exposure at various intervals up to 12 months. Samples were analyzed by thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC). Unlike heating at 121 degrees C, heating at 100 degrees C produced no significant loss of succinylcholine chloride, independent of the initial pH. Succinylcholine chloride was hydrolyzed only minimally over 23 months if the solution was stored at 4-6 degrees C. A 10% loss of drug content occurred if solutions were kept at 20-26 degrees C for five months, at 35 degrees C for one month, or at 70 degrees C for one day. Initial degradation was slowed if the solution was protected from light. The assessments by TLC proved to be more sensitive than the HPLC measurements. Succinylcholine chloride injection sterilized at 100 degrees C for 30 minutes can be stored for up to five months at room temperature if protected from light. The preparation is stable for at least two years under refrigeration. PMID:2028996

  14. Methanol oxidation at platinum electrodes in acid solution: comparison between model and real catalysts

    Directory of Open Access Journals (Sweden)

    A. V. TRIPKOVIC

    2006-12-01

    Full Text Available Methanol oxidation in acid solution was studied at platinum single crystals, Pt(hkl, as the model catalyst, and at nanostructural platinum supported on high surface area carbon, Pt/C, as the real catalyst. The linear extrapolation method was used to determine the beginning of hydroxyl anion adsorption. Structural sensitivity of the adsorption was proved and a correlation with the onset of the methanol oxidation current was established at all catalysts. Bisulfate and chloride anions were found to decrease the methanol oxidation rate, but probably did not influence the reaction parth. The specific activity for the reaction increased in the sequence Pt(110 < Pt/C < Pt(111, suggesting that the activity of the supported Pt catalyst can be correlated with the activities of the dominating crystal planes on its surface.

  15. Highly microporous carbons derived from a complex of glutamic acid and zinc chloride for use in supercapacitors

    Science.gov (United States)

    Dong, Xiao-Ling; Lu, An-Hui; He, Bin; Li, Wen-Cui

    2016-09-01

    The selection of carbon precursor is an important factor when designing carbon materials. In this study, a complex derived from L-glutamic acid and zinc chloride was used to prepare highly microporous carbons via facile pyrolysis. L-glutamic acid, a new carbon precursor with nitrogen functionality, coordinated with zinc chloride resulted in a homogeneous distribution of Zn2+ on the molecular level. During pyrolysis, the evaporation of the in situ formed zinc species creates an abundance of micropores together with the inert gases. The obtained carbons exhibit high specific surface area (SBET: 1203 m2 g-1) and a rich nitrogen content (4.52 wt%). In excess of 89% of the pore volume consists of micropores with pore size ranging from 0.5 to 1.2 nm. These carbons have been shown to be suitable for use as supercapacitor electrodes, and have been tested in 6 M KOH where a capacitance of 217 F g-1 was achieved at a current density of 0.5 A g-1. A long cycling life of 30 000 cycles was achieved at a current density of 1 A g-1, with only a 9% loss in capacity. The leakage current through a two-electrode device was measured as 2.3 μA per mg of electrode and the self-discharge characteristics were minimal.

  16. The polarographic electroreduction of uranyl ion in arsenic acid solution

    International Nuclear Information System (INIS)

    The electroreduction of uranyl ion in arsenic acid studied by d.c. polarography shows one reduction wave at all the used arsenic acid concentrations corresponding to one electron reduction mechanism. At low arsenic acid concentration (0,1 - 0,3 M)UO2(ClO4)2 is reduced to HUO2AsO4. At higher acid concentration (0,6 M) the HUO2AsO4 molecules are reduced to UO2+ (pentavalent uranium). It is also reliable to study polarographic behaviour of uranyl ions in arsenic acid solutions up to pH 3,01. It is also possible to apply this method for the analytical determination of uranyl ion concentrations up to 2 mM. (Author)

  17. Removal and recovery of furfural, 5-hydroxymethylfurfural, and acetic acid from aqueous solutions using a soluble polyelectrolyte.

    Science.gov (United States)

    Carter, Brian; Gilcrease, Patrick C; Menkhaus, Todd J

    2011-09-01

    In the cellulosic ethanol process, furfural, 5-hydroxymethylfurfural (HMF), and acetic acid are formed during the high temperature acidic pretreatment step needed to convert biomass into fermentable sugars. These compounds can inhibit cellulase enzymes and fermentation organisms at relatively low concentrations (≥ 1 g/L). Effective removal of these inhibitory compounds would allow the use of more severe pretreatment conditions to improve sugar yields and lead to more efficient fermentations; if recovered and purified, they could also be sold as valuable by-products. This study investigated the separation of aldhehydes (furfural and HMF) and organic acid (acetic acid) inhibitory compounds from simple aqueous solutions by using polyethyleneimene (PEI), a soluble cationic polyelectrolyte. PEI added to simple solutions of each inhibitor at a ratio of 1 mol of functional group to 1 mol inhibitor removed up to 89.1, 58.6, and 81.5 wt% of acetic acid, HMF, and furfural, respectively. Furfural and HMF were recovered after removal by washing the polyelectrolyte/inhibitor complex with dilute sulfuric acid solution. Recoveries up to 81.0 and 97.0 wt% were achieved for furfural and HMF, respectively. The interaction between PEI and acetic acid was easily disrupted by the addition of chloride ions, sulfate ions, or hydroxide ions. The use of soluble polymers for the removal and recovery of inhibitory compounds from biomass slurries is a promising approach to enhance the efficiency and economics of an envisioned biorefinery. PMID:21455937

  18. Preparation of robust polyamide microcapsules by interfacial polycondensation of p-phenylenediamine and sebacoyl chloride and plasticization with oleic acid.

    Science.gov (United States)

    Rosa, Natacha; Martins, Gabriela V; Bastos, Margarida M S M; Gois, Joana R; Coelho, Jorge F J; Marques, Juliana; Tavares, Carlos J; Magalhães, Fernão D

    2015-01-01

    Microcapsules produced by interfacial polycondensation of p-phenylenediamine (PPD) and sebacoyl chloride (SC) were studied. The products were characterized in terms of morphology, mean diameter and effectiveness of dodecane encapsulation. The use of Tween 20 as dispersion stabilizer, in comparison with polyvinyl alcohol (PVA), reduced considerably the mean diameter of the microcapsules and originated smoother wall surfaces. When compared to ethylenediamine (EDA), microcapsules produced with PPD monomer were more rigid and brittle, prone to fracture during processing and ineffective retention of the core liquid. The use of diethylenetriamine (DETA) cross-linker in combination with PPD did not decrease capsule fragility. On the other hand, addition of a small fraction of oleic acid to the organic phase remarkably improved wall toughness and lead to successful encapsulation of the core-oil. Oleic acid is believed to act as a plasticizer. Its incorporation in the polymeric wall was demonstrated by FTIR and (1)H-NMR.

  19. Removal of fluoride in aqueous solution by adsorption on acid activated water treatment sludge

    Science.gov (United States)

    Vinitnantharat, Soydoa; Kositchaiyong, Sriwilai; Chiarakorn, Siriluk

    2010-06-01

    This paper reports the use of a pellet of adsorbent made from water treatment sludge (S) and acid activated water treatment sludge (SH) for removal of fluoride in the batch equilibration technique. The influence of pH, adsorbent dosage, temperature and effect of other ions were employed to find out the feasibility of acid activated adsorbent to remove fluoride to the permissible concentration of 0.7 mg/L. The results from the adsorption isotherm followed both Langmuir and Freundlich models and the highest fluoride removal was found for adsorbent activated with acetic acid at 2.0 mol/L. The optimum adsorbent dosage was found at 40 g/L, 0.01 mol/L acid activated adsorbent which was able to adsorb fluoride from 10 down to 0.11 mg/L. The adsorption capacity was decreased when the temperature increased. This revealed that the adsorption of fluoride on SH was exothermic. In the presence of nitrate and carbonate ions in the aqueous solution, fluoride removal efficiency of SH decreased from 94.4% to 86.6% and 90.8%, respectively. However, there is no significant effect in the presence of sulfate and chloride ions.

  20. Adsorption of β-Naphthalenesulfonic Acid/Sulfuric Acid From Their Solution by Weakly Basic Resin

    Institute of Scientific and Technical Information of China (English)

    李长海; 石宏仁; 等

    2003-01-01

    Experiments for single and bisolute competitive adsorption were carried out to investigate the adsorption behavior of β-naphthalenesulfonic acid(NSA and sulfuric acid from their solution at 25℃ onto weakly basic resin D301R,Adsorption affinity of sulfuric acid on D301R was found to be much higher than that of NSA.The data of single-solute adsorption were fitted to the Langmuir model and the Freundlich adsorption model.The ideal adsorbed solution theory(IAST) coupled with the single-solute adsorption models were used to predict the bisolute competitive adsorption equilibria.The IAST coupled with the Langmuir and the Freundlich model for sulfuric acid and NSA.Respectively,yields the favorable representation of the bisolute competitive adsorption behavior.

  1. Interactions of acidic solutions with sediments: a case study

    International Nuclear Information System (INIS)

    A methodology is presented for investigating the chemical interactions of acidic solutions with sediments. The MINTEQ geochemical computer code was used to predict solid-phase reactions that might occur when acidic solutions contact neutral sediments which, in turn, may control the concentrations of certain dissolved components. Results of X-ray diffraction analysis of laboratory samples of sediments that have been contacted with acidic uranium mill tailings solutions suggest gypsum and jarosite precipitated. These same mineralogical changes were identified in sediment samples collected from a drained uranium mill evaporation pond (Lucky Mc mine in Wyoming) with a 10-year history of acid attack. Geochemical modeling predicted that these same phases and several amorphous solids not identifiable by X-ray diffraction should have precipitated in the contacted sediments. An equilibrium conceptual model consisting of an assemblage of minerals and amorphous solid phases was then developed to represent a sediment column through which uranium mill tailings solutions were percolated. The MINTEQ code was used to predict effluent solution concentrations resulting from the reactions of the tailings solution with the assemblage of solid phases in the conceptual model. The conceptual model successfully predicted the concentrations of several of the macro-constituents (e.g., Ca, SO4, Al, Fe, and Mn), but was not successful in modeling the concentrations of trace elements. The lack of success in predicting the observed trace metal concentrations suggests that other mechanisms, such as adsorption, must be included in future models. The geochemical modeling methodology coupled with the laboratory and field studies should be applicable to a variety of waste disposal problems

  2. Scientific Opinion on the safety assessment of the active substances iron powder, activated carbon, calcined kaolin, sodium chloride, polyacrylic acid, sodium salt, crosslinked and calcium chloride, for use as active system in food contact materials

    Directory of Open Access Journals (Sweden)

    EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF

    2014-05-01

    Full Text Available This scientific opinion of the EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids deals with the safety assessment of the active substances iron powder, activated carbon, calcined kaolin, sodium chloride, polyacrylic acid, sodium salt, crosslinked and calcium chloride, used in mixture which is packed into labels, for absorbing oxygen from the headspace surrounding packed food. All substances of this formulation have been evaluated and approved for use as additives in plastic food contact materials or as food supplements. Migration of substances from the labels and formation and release of volatile constituents are not expected under the intended conditions of use. The CEF Panel concluded that the use of substances iron powder, activated carbon, calcined kaolin, sodium chloride, polyacrylic acid, sodium salt, crosslinked and calcium chloride does not raise a safety concern when used in oxygen absorbers in labels, which prevent the physical release of their content into the food. When placed in the headspace of the packaging or when used in direct contact with foods, the labels should not intentionally or unintentionally come into direct contact with liquid foods or foods that have an external aqueous phase on the surface such as sliced fruits.

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

    Science.gov (United States)

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

    2014-09-01

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

  4. Effect of chlormequat chloride, ß-naphthoxyacetic acid and ethephon on early and total yield of tomato in open field

    Directory of Open Access Journals (Sweden)

    Jan Borkowski

    2013-12-01

    Full Text Available Tomato seedlings in hotbed with Antywylegacz (chlormequat chloride to suppress their excessive elongation before transplanting, were used. Their first 2-3 flower clusters were dipped in the field in Betokson (ß-naphthoxyacetic acid to induce better early fruit set and the plants were sprayed with Ethrel (ethephon just before the first fruits become pink, to stimulate earlier ripening and increase early yield. The experiment was carried out during 3 years with the cultivars 'Venture', 'New Yorker' and 'Nesthackchen' (only in 1975. Application of chlormequat alone prevented excessive growth of the seedlings but did not increase early yield significantly. ß-naphthoxyacetic acid alone was effectiveevery year and always increased early yield. Chlormequat followed by ß-naphthoxyacetic treatment showed always a tendency to increase early yield more than ß-naphthoxyacetic acid alone. Treatment with ß-naphthoxyacetic acid, alone or in combination with other treatments, lowered the total yield. Ethephon used solely or in combination with other treatments usually was ineffective.

  5. Fick's 2nd law - Complete solutions for chloride ingress into concrete – with focus on time dependent diffusivity and boundary condition

    OpenAIRE

    Frederiksen, Jens M.; Mejlbro, Leif; Nilsson, Lars-Olof

    2009-01-01

    This report focuses on models of chloride ingress into concrete that are based on mathematical solutions of Fick's second law. In recent years a lot of confusion has been identified concerning these models. In some cases time-dependencies of diffusivity have been used in a mathematically incorrect way. In other cases field and laboratory data from one way of describing the time-dependency of these diffusivities has been used in models that are based on another model. This is now clarified...

  6. The reducibility of sulphuric acid and sulphate in aqueous solution

    International Nuclear Information System (INIS)

    In connection with the Swedish project for final storage of spent fuel elements it was necessary to assess whether dissolved sulphate can corrode the copper canister. A simple reaction between copper and sulphate is thermodynamically impossible, but copper can react to give copper sulphide if an additional electron donor such as iron(II) is available. The problem was extended to the more general question of the reducibility of sulphur(VI) in dilute aqueous solution. Chemical reduction of sulphate does not take place in dilute solution at temperatures below 100oC. In experiments on the reduction of sulphates under hydrothermal conditions a reaction only takes place at temperatures above 275-300oC. The oxidising action of sulphuric acid on metals becomes perceptible only at acid concentrations over 45-50%. In experiments on the cathodic reduction of 74% sulphuric acid the formation of hydrogen sulphide and elementary sulphur starts, depending on the current density, at 50-130oC, and polarographic measurements suggest that the reducible species is not the hydrogen sulphate ion but molecular sulphuric acid. The resistance of copper to oxygen-free sulphuric acid up to a concentration of 60% is well-known. Numerous processes in industrial electrochemistry take place in sulphuric acid or sulphate electrolytes. The reversible metal/metal-sulphate electrodes of lead and cadmium are unstable relative to the corresponding metal sulphides. Nevertheless the reversible lead sulphate electrode does not fail from sulphide formation. All these facts confirm that sulphur(VI) in dilute solution is completely inert towards chemical reducing agents and also to cathodic reduction. Thus corrosion of copper by sulphate under final-storage conditions and in the absence of sulphate reducing bacteria can be almost certainly be ruled out. (author) 5 figs., 85 refs

  7. Ozonation of Sulfur Dioxide in Sulphuric Acid Solution

    Institute of Scientific and Technical Information of China (English)

    LIU Limei; ZHANG Shuting; L(U) Xuebin; YU Xiaoyan; ZHI Suli

    2013-01-01

    In this study,the oxidation rates of sulfur dioxide (SO2) in sulphuric acid solution by ozone and oxygen were compared,and the oxidation mechanism of ozone on SO2 was investigated.The results showed that the oxidation-reduction potential of the acidic solution was enhanced,the transformation rate of sulfuric acid to sulphuric acid was increased and the absorption driving force was improved in the presence of ozone.By comparing the amount of sulfate ions measured in the experiments and the theoretical amount of sulfate ions calculated from the amount of ozone consumed in the reaction,it can be confirmed that oxygen free radicals from dissociation of ozone are reactive as an efficient oxidant and oxygen from ozone generator participates in the reaction with SO2.0.602tmol of effective oxygen was introduced into the reaction by one mole of ozone in 10.15 min at sulphuric acid concentration of 3% (by mass),SO2 concentration of 1.33% (by volume) and oxygen flow rate of 1.5 L·min-1 from ozone generator.

  8. Regioselective dimerization of ferulic acid in a micellar solution

    DEFF Research Database (Denmark)

    Larsen, E; Andreasen, Mette Findal; Christensen, L P

    2001-01-01

    Dehydrodimers of hydroxycinnamates play an important role in the cross-linking of plant cell walls. An aqueous solution of quaternary ammonium salts with a long aliphatic chain is known to spontaneously organize itself into micelles with the ionic part at the outer sphere. It is shown that regioi......Dehydrodimers of hydroxycinnamates play an important role in the cross-linking of plant cell walls. An aqueous solution of quaternary ammonium salts with a long aliphatic chain is known to spontaneously organize itself into micelles with the ionic part at the outer sphere. It is shown...... that regioisomeric ferulic acid dehydrodimers can be obtained in one step from trans-ferulic acid after attachment to these micelles and using the biomimetic peroxidase-H2O2 system. The surfactant hexadecyltrimethylammonium hydroxide yielded trans-4-(4-hydroxy-3-methoxybenzylidene)-2-(4-hydroxy-3-methoxyphenyl)-5......-oxotetrahydrofuran-3-carboxylic acid (25%), (E,E)-4,4'-dihydroxy-5,5'-dimethoxy-3,3'-bicinnamic acid (21%), and trans-5-[(E)-2-carboxyvinyl]-2-(4-hydroxy-3-methoxyphenyl)-7-methoxy-2,3-dihydrobenzofuran-3-carboxylic acid (14%), whereas the surfactant tetradecyltrimethylammonium bromide gave 4-cis, 8-cis-bis(4...

  9. Universal charge quenching and stability of proteins in 1-methyl-3-alkyl (hexyl/octyl) imidazolium chloride ionic liquid solutions.

    Science.gov (United States)

    Rawat, Kamla; Bohidar, H B

    2012-09-13

    This study reports pH dependent stability of protein dispersions of five common proteins, bovine serum albumin (BSA), human serum albumin (HSA), immunoglobulin (IgG), β-lactoglobulin (β-Lg), and gelatin-B (Gel-B), all having isoelectric pH, pI ≈ 5, in room temperature ionic liquid solutions of 1-methyl-3-alkyl (hexyl/octyl) imidazolium chloride (concentration 0-0.2% w/v). Molecular hydrophobicity index, (H-index = hydrophobicity/hydrophilicity) of these molecules spanned the range 0.43-0.87. Electrophoretic characteristics, surface tension data and hydrodynamic size information revealed that IL solutions provide dispersion stability owing to specific protein-IL binding which did not alter their pI values though their surface charge was considerably screened. Change in maximum (ζ(max)) and minimum (ζ(min)) zeta potential values observed at pH ~3 (maximum protonated state) and pH ~8 (maximum deprotonated state) could be described universally as function of IL concentration, c as Δζ(x) = [1 - exp(-ac)] where Δζ(x) is either |(ζ(max) - ζ(w))|/ζ(w) or |(ζ(min) - ζ(w))|/ζ(w), and ζ(w) is the corresponding value in water. Tensiometry data showed two major stages of protein-IL interactions: (i) for c cmc free IL-aggregates begin to form. Similarly, we can define Δγ(x) as either |(γ(max) - γ(w))|/γ(w) at pH 3 or |(γ(min) - γ(w))|/γ(w) at pH 8. Both Δζ(x) and Δγ(x) showed linear dependence with c, Δγ(min, max) (or Δζ(min, max)) = (1 - K(γ) (or K(ζ)) H-index), where the slopes K(ζ) and K(γ) defined intermolecular interactions. Hydrodynamic radii data revealed protein stabilization, circular dichroism spectra implied retention of secondary structures, and Raman spectra confirmed a marginal increase in water structure. Results concluded that selective binding of IL molecules to protein surface in the form of bilayer screen protein surface charge, thereby, contributing to its dispersion stability. PMID:22891622

  10. Adsorption of Rh(III) complexes from chloride solutions obtained by leaching chlorinated spent automotive catalysts on ion-exchange resin Diaion WA21J

    International Nuclear Information System (INIS)

    It was found that Rh, Pd and Pt contained in the spent ceramic automotive catalysts could be effectively extracted by dry chlorination with chlorine. In order to concentrate Rh(III) ions contained in the chloride solutions obtained, thermodynamic and kinetics studies for adsorption of Rh(III) complexes from the chloride solutions on an anionic exchange resin Diaion WA21J were carried out. Rh, Pd, Pt, Al, Fe, Si, Zn and Pb from the chloride solution could be adsorbed on the resin. The distribution coefficients (Kd) of Rh(III) decreased with the increase in initial Rh(III) concentration or in adsorption temperature. The isothermal adsorption of Rh(III) was found to fit Langmuir, Freundlich and Dubinin-Kaganer-Radushkevich models under the adsorption conditions. The maximum monolayer adsorption capacities Qmax based on Langmuir adsorption isotherms were 6.39, 6.61 and 5.81 mg/g for temperatures 18, 28 and 40 deg. C, respectively. The apparent adsorption energy of Rh was about -7.6 kJ/mol and thus Rh(III) adsorption was a physical type. The experimental data obtained could be better simulated by pseudo-first-order kinetic model and the activation energy obtained was 6.54 J/mol. The adsorption rate of Rh(III) was controlled by intraparticle diffusion in most of time of adsorption process.

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

    International Nuclear Information System (INIS)

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

  12. DC diaphragm discharge in water solutions of selected organic acids

    Science.gov (United States)

    Vyhnankova, Edita J.; Hammer, Malte U.; Reuter, Stephan; Krcma, Frantisek

    2015-07-01

    Effect of four simple organic acids water solution on a DC diaphragm discharge was studied. Efficiency of the discharge was quantified by the hydrogen peroxide production determined by UV-VIS spectrometry of a H2O2 complex formed with specific titanium reagent. Automatic titration was used to study the pH behaviour after the plasma treatment. Optical emission spectroscopy overview spectra were recorded and detailed spectra of OH band and Hβ line were used to calculate the rotational temperature and comparison of the line profile (reflecting electron concentration) in the acid solutions. Contribution to the topical issue "The 14th International Symposium on High Pressure Low Temperature Plasma Chemistry (HAKONE XIV)", edited by Nicolas Gherardi, Ronny Brandenburg and Lars Stollenwark

  13. Influence of sodium chloride and weak organic acids (flux residues) on electrochemical migration of tin on surface mount chip components

    DEFF Research Database (Denmark)

    Verdingovas, Vadimas; Jellesen, Morten Stendahl; Ambat, Rajan

    2013-01-01

    The electrolytic properties of sodium chloride and no-clean solder flux residue, and their effects on electrochemical migration and dendrite growth on surface mount chip capacitors were investigated. The leakage current dependency on concentration of contaminants was measured by a solution...... conductivity method and compared with current measurements using DC voltage. The effect of electrolyte concentration and potential bias on the probability of electrochemical migration was investigated using a water droplet method on chip capacitors. The results from leakage current and conductivity measurement...... showed a difference which is caused by polarization effects, and demonstrated existing issues when indexing contamination levels on printed circuit board assemblies using a standardised solvent extract method. The experimental results showed that dendrite growth was dependent on the type and amount...

  14. Functionalyzed Polyampholytes on the Basis of Copolymers of N,N-Diallyl-N,N-dimethylammonium Chloride and Maleic Acid

    DEFF Research Database (Denmark)

    Vlasov, Petr; Chernyy, Sergey; Domnina, Nina

    2010-01-01

    Polyampholytes were prepared by radical copolymerization of N,N-diallyl-N,N-dimethylammonium chloride and maleic acid. The esterification and subsequent hydrazinolysis permitted to introduce hydrazide groups capable of formation of the coordination bond with copper ions. The formation of complex...... between the hydrazide groups of polyampholyte and Cu2+ ions was established by electronic spectroscopy. It was shown that the coordination of two hydrazide groups in the complex was hampered because of the polymeric nature of the ligand. It is shown that the created functionalized polyampholytes exhibit...... fungiostatic activity. The highest inhibiting effect on the growth of the pathogenic fungus Fusarium oxysporumis observed for complexes of the hydrazide-containing polyampholytes with Cu2+ ions....

  15. PHOTO-INDUCED DOPED POLYANILINE BY THE VINYLIDENE CHLORIDE AND METHYL ACRYLATE COPOLYMER AS PHOTO ACID GENERATOR

    Institute of Scientific and Technical Information of China (English)

    LI Suzhen; WAN Meixiang

    1997-01-01

    The emeraldine base form of polyaniline (PANI) can be doped by a photo-induced doping method. In this method a copolymer of vinylidene chloride and methyl acrylate (VCMAC) was used as photo acid generator which can release proton when it is exposed to ultraviolet light (λ = 254 nm). The structure of PANI-VCMAC system before and after irradiation was characterized by elemental analysis, IR, XPS, and SEM images. Results obtained indicate that the photo-induced doping characteristics, such as doping position and type of charge carriers, are similar to that of PANI doped with HCl. The poor roomtemperature conductivity (~ 10-5S/cm) of PANI-VCMAC system after irradiation may be due to low doping degree (~pH= 3) and the difference in morphology as compared with PANI-HCl film.

  16. Pulse Radiolysis of Adrenaline in Acid Aqueous Solutions

    DEFF Research Database (Denmark)

    Gohn, M.; Getoff, N.; Bjergbakke, Erling

    1976-01-01

    Pulse radiolysis of adrenaline in acid aqueous solutions (pH 1–3) was carried out. The rate constants for the reactions of adrenaline with H and OH were determined: k(H + adr.) = (0·9±0·1) × 109 dm3 mol−1s−1; k(OH + adr.) = (1·65±0·15) × 1010 dm3 mol−1s−1. The H-adduct of adrenaline has two λmax...

  17. Dynamics of the separation of amino acid and mineral salt in the stationary dialysis of solutions with an MK-40 profiled sulfo group cation exchange membrane

    Science.gov (United States)

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

    2012-11-01

    The conjugated diffusion transport of amino acid and mineral salt through a profiled sulfo group cation exchange membrane that simulates the extraction of amino acid from wash waters of microbiological production containing mineral components not used in synthesis is studied. The competitive nature of the conjugation of flows resulting in a decrease in the rate of the mass transfer of components and their separation factor is established from a comparative analysis of experimental data on the diffusion transfer of phenylalanine and sodium chloride in the form of hydrogen from individual and mixed solutions through a profiled sulfo group cation exchange membrane. The range of concentrations and the ratio of components in solution corresponding to the effective separation of phenylalanine and sodium chloride are determined.

  18. Thermodynamics of DL-α-aminobutyric acid induced solvation mechanism in aqueous KCl solutions at 288.15-308.15 K

    Science.gov (United States)

    Mondal, S.; Ghosh, S.; Hossain, A.; Mahali, K.; Roy, S.; Dolui, B. K.

    2016-09-01

    The solubilities of DL-α-aminobutyric acid in KCl solutions of different concentrations are measured at 288.15-308.15 K. Gibbs energies and entropies have been determined for transfer of α-aminobutyric acid form water to aqueous KCl solution at 298.15 K. The cavity, dipole-dipole and other interactions affecting the solubility, as well as stability of the amino acid in solution are also evaluated. Gibbs energy and entropy of transfer due to interactions are computed to create the model of the complex solute-solvent and solventsolvent interactions. Molar volume, densities, dipole moment of solvent and diameter of co-solvent in aqueous potassium chloride are also evaluated.

  19. Role of Chloride Ion and Dissolved Oxygen in Electrochemical Corrosion of AA5083-H321 Aluminum-Magnesium Alloy in NaCl Solutions under Flow Conditions

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Flow-induced corrosion consists electrochemical and mechanical components. The present paper has to assessed the role of chloride ion and dissolved oxygen in the electrochemical component of flow induced corrosion for AA5083-H321 aluminum-magnesium alloy which is extensively used in the construction of high-speed boats, submarines, hovercrafts, and desalination systems, in NaCl solutions. Electrochemical tests were carried out at flow velocities of 0, 2, 5, 7 and 10 m/s, in aerated and deaerated NaCl solutions with different sodium chloride concentrations. The results showed that the high rate of oxygen reduction under hydrodynamic conditions causes an increase in the density of pits on the surface. The increase of chloride ions concentration under flow conditions accelerates the rate of anodic reactions, but have no influence on the cathodic reactions. Thus, in the current work, it was found that under flow conditions, due to the elimination of corrosion products inside the pits, corrosion resistance of the alloy is increased.

  20. Viscosity and density of ternary solution of calcium chloride + sodium chloride + water from T = (293.15 to 323.15) K

    OpenAIRE

    Qiblawey, Hazim; Arshad, Mohammad; Easa, Ahmed; Atilhan, Mert

    2014-01-01

    Viscosities and densities of ternary systems of CaCl2–NaCl–water were measured in the range of T = (293.15 to 323.15) K at 5 K intervals and up to 4.5 mol·kg–1. Two equations based on the Exponential and Goldsack and Franchetto models were applied to correlate the experimental viscosity data as a function of concentration and temperature. The optimized parameters showed that the presence of CaCl2 had a prevailing effect on the viscosity of the ternary solutions than NaCl. The dependency of th...

  1. Separation of ruthenium from nitric acid solutions using carbon tetrachloride

    International Nuclear Information System (INIS)

    The noble metal, ruthenium is one of the major fission product elements produced with high fission yield, mainly in for breeder reactors using 239Pu fuels. In the aqueous reprocessing of spent fuels for the recovery of U and Pu by PUREX process ruthenium interferes in the solvent extraction stage. In the treatment of high level liquid waste for its disposal, oxides of Ru are formed, which contaminate the surrounding environment owing to their high vapour pressure. Hence, it is desirable to separate from the waste solution prior to its processing for disposal. A simple and feasible method has been employed in the present work for the separation and recovery of ruthenium from aqueous nitric acid medium using ammonium ceric nitrate (ACN) and carbon tetrachloride (CCl4). The efficiency in the separation of Ru was investigated under various experimental conditions such as acidity and ageing effect. Separation efficiency was observed to decrease with increasing nitric acid concentration. Maximum separation was achieved at 1 M nitric acid. Further studies were carried out to investigate the effect of ageing on the separation efficiency ruthenium. With increase in time, separation percentage of ruthenium was decreasing in all concentrations of nitric acid studied. (author)

  2. Corrosion Behavior of Duplex Stainless Steels in Acidic-Chloride Solutions Studied with Micrometer Resolution

    OpenAIRE

    Femenia, Marc

    2003-01-01

    The local corrosion behavior of duplex stainless steel (DSS)is affected by a wide variety of factors. Localized corrosionof DSS frequently starts at micrometer scale inclusions orprecipitates, which are often segregated in theaustenite-ferrite boundary regions. Moreover, due to thepartitioning of the key alloying elements of ferrite (Cr andMo) and austenite (N and Ni), the local interactions betweenthe phases must also be considered. The aim of this doctoral study was to increase the knowledg...

  3. Stress corrosion crack growth studies on nitrogen added AISI type 316 stainless steel and its weld metal in boiling acidified sodium chloride solution using the fracture mechanics approach

    Energy Technology Data Exchange (ETDEWEB)

    Shaikh, H.; George, G.; Khatak, H.S. [Indira Gandhi Centre for Atomic Research, Kalpakkam (India). Div. of Metallurgy; Schneider, F.; Mummert, K. [Institut fuer Festkoerper- und Werkstofforschung Dresden e.V. (Germany). Inst. fuer Metallische Werkstoffe

    2000-10-01

    Compact tension specimens of nitrogen-added AISI type 316 austenitic stainless steel and its weld metal were subject to stress corrosion cracking (SCC) testing in a boiling solution containing 5 M sodium chloride + 0.15 M sodium sulphate + 2.5 ml/l hydrochloric acid solution using the constant extension rate testing (CERT) technique. The extension rate of testing was 10 microns per hour. The threshold values of stress intensify factor (K{sub ISCC}) and J-integral (J{sub ISCC}) were taken as those values of K{sub I} and J{sub I} at which about 25 microns of SCC crack growth was observed. These threshold values were about four times higher and plateau crack growth rates (PCGR) were nearly one order of magnitude lower for the base metal vis-a-vis the weld metal. Fractographic observations indicated failure by transgranular SCC (TGSCC) of austenite in both the base and weld metal. No stress-assisted dissolution of delta-ferrite or its interface with austenite, was observed. (orig.) [German] CT-Proben von Grund- und Schweissnahtwerkstoff des stickstoffhaltigen Stahles AISI 316 LN wurden Spannungsrisskorrosionstests in siedender chloridhaltiger Loesung (5 M Natriumchlorid/0,15 M Natriumsulfat/0,03 M Salzsaeure) unterzogen. Die Tests erfolgten bei konstanter Dehnrate (CERT-Test) von 10 {mu}m/h. Als Schwellwerte der Initiierung von Spannungsrisskorrosion K{sub ISCC} und I{sub ISCC} wurden die Werte des Spannungsintensitaetsfaktors K{sub I} und des J-Integrals J{sub I} ermittelt, bei denen ein Risswachstum von 25 {mu}m auftrat. Dabei wies der Grundwerkstoff 4-fach hoehere Schwellwerte K{sub ISCC} und J{sub ISCC} auf als der Schweissnahtwerkstoff. Auch die Risswachstumsraten im Plateaubereich der Risswachstumsrate-Spannungsintensitaetskruven waren am Grundwerkstoff um eine Groessenordnung geringer als am Schweissnahtwerkstoff. Die fraktorgrahischen Untersuchungen zeigten an beiden Materialien Schaedigung durch transkristalline Spannungsrisskorrosion. Eine

  4. Adsorption of itaconic acid from aqueous solutions onto alumina

    Directory of Open Access Journals (Sweden)

    JELENA J. GULICOVSKI

    2008-08-01

    Full Text Available Itaconic acid, IA (C5H6O4, was investigated as a potential flocculant for the aqueous processing of alumina powders. The adsorption of IA, as a function of its concentration and pH value of the solution, onto the alumina surface was studied by the solution depletion method. The stability of the suspensions in the presence of itaconic acid was evaluated in light of the surface charge of the alumina powder used, the degree of dissociation of IA, as well as the sedimentation behavior and rheology of the suspensions. It was found that the adsorption process is extremely pH dependent; the maximum adsorption of IA onto alumina surface occurring at a pH close to the value of the first IA dissociation constant, pKa1. Also, IA does not influence the value of the point of zero charge of alumina. It was shown that IA represents an efficient flocculant for concentrated acidic alumina suspensions.

  5. Transient increase in neuronal chloride concentration by neuroactive amino acids released from glioma cells

    Directory of Open Access Journals (Sweden)

    Cristina eBertollini

    2012-11-01

    Full Text Available Neuronal chloride concentration ([Cl-]i is known to be dynamically modulated and alterations in Cl- homeostasis may occur in the brain at physiological and pathological conditions, being also likely involved in glioma-related seizures. However, the mechanism leading to changes in neuronal [Cl-]i during glioma invasion are still unclear. To characterize the potential effect of glioma released soluble factors on neuronal [Cl-]i, we used genetically encoded CFP/YFP-based ratiometric Cl-Sensor transiently expressed in cultured hippocampal neurons. Exposition of neurons to glioma conditioned medium (GCM caused rapid and transient elevation of [Cl-]i, resulting in the increase of fluorescence ratio, which was strongly reduced by blockers of ionotropic glutamate receptors APV and NBQX. Furthermore, in HEK cells expressing GluR1-AMPA receptors, GCM activated ionic current with efficacy similar to those caused by glutamate, supporting the notion that GCM contains glutamate or glutamatergic agonists, which cause neuronal depolarization, activation of NMDA and AMPA/KA receptors leading to elevation of [Cl-]i. Chromatographic analysis of the GCM showed that it contained several aminoacids, including glutamate, whose release from glioma cells did not occur via the most common glial mechanisms of transport, or in response to hypoosmotic stress. GCM also contained glycine, whose action contrasted the glutamate effect. Indeed, strychnine application significantly increased GCM-induced depolarization and [Cl-]i rise. GCM-evoked [Cl-]i elevation was not inhibited by antagonists of Cl- transporters and significantly reduced in the presence of anion channels blocker NPPB, suggesting that Cl-selective channels are a major route for GCM-induced Cl- influx. Altogether, these data show that glioma released aminoacids may dynamically alter Cl- equilibrium in surrounding neurons, deeply interfering with their inhibitory balance, likely leading to physiological and

  6. Effect of phytic acid, ethylenediaminetetraacetic acid, and chitosan solutions on microhardness of the human radicular dentin

    Directory of Open Access Journals (Sweden)

    Vineeta Nikhil

    2016-01-01

    Full Text Available Aim: The purpose of this study was to evaluate the effect of phytic acid, ethylenediaminetetraacetic acid (EDTA, and chitosan solutions on the microhardness of human radicular dentin. Materials and Methods: Thirty dentin specimens were randomly divided into three groups of 10 specimens each according to the irrigant used: G1 - 1% phytic acid, G2 - 17% EDTA, and G3 - 0.2% chitosan. A standardized volume of each chelating solution was used for 3 min. Dentin microhardness was measured before and after application at the cervical, middle, and apical levels with a Vickers indenter under a 200-g load and a 10-s dwell time. The results were analyzed using one-way analysis of variance (ANOVA and Student′s t test. Results: Microhardness of the radicular dentin varied at the cervical, middle, and apical levels. EDTA had the greatest overall effect, causing a sharp percentage reduction in dentin microhardness with a significant difference from phytic acid and chitosan (P = 0.002. However, phytic acid and chitosan differed insignificantly from each other (P = 0.887. Conclusion: All tested chelating solutions reduced microhardness of the radicular dentin layer at all the levels. However, reduction was least at the apical level. EDTA caused more reduction in dentin microhardness than chitosan while phytic acid reduced the least.

  7. Synthesis of nesquehonite by reaction of gaseous CO2 with Mg chloride solution: its potential role in the sequestration of carbon dioxide.

    Science.gov (United States)

    Ferrini, Vincenzo; De Vito, Caterina; Mignardi, Silvano

    2009-09-15

    In this paper is reported a novel method to synthesize nesquehonite, MgCO(3) x 3H(2)O, via reaction of a flux of CO(2) with Mg chloride solution at 20+/-2 degrees C. The reaction rate is rapid, with carbonate deposition almost complete in about 10 min. The full characterization of the product of synthesis has been performed to investigate its potential role as a "CO(2)-sequestering medium" and a means of disposing Mg-rich wastewater. We investigated the nesquehonite synthesized using SEM, XRD, FTIR and thermal analysis. The thermodynamic and chemical stability of this low-temperature hydrated carbonate of Mg and its possible transformation products make our method a promising complementary solution to other methods of CO(2) sequestration. Carbonation via magnesium chloride aqueous solutions at standard conditions represents a simple and permanent method of trapping CO(2). It could be applied at point sources of CO(2) emission and could involve rejected brine from desalination plants and other saline aqueous wastes (i.e., "produced water"). The likelihood of using the resulting nesquehonite and the by-products of the process in a large number of applications makes our method an even more attractive solution. PMID:19303209

  8. Synthesis of nesquehonite by reaction of gaseous CO{sub 2} with Mg chloride solution: Its potential role in the sequestration of carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Ferrini, Vincenzo; De Vito, Caterina [Dipartimento di Scienze della Terra, Universita degli Studi di Roma ' La Sapienza' , P.le A. Moro, 5, 00185 Roma (Italy); Mignardi, Silvano, E-mail: silvano.mignardi@uniroma1.it [Dipartimento di Scienze della Terra, Universita degli Studi di Roma ' La Sapienza' , P.le A. Moro, 5, 00185 Roma (Italy)

    2009-09-15

    In this paper is reported a novel method to synthesize nesquehonite, MgCO{sub 3}.3H{sub 2}O, via reaction of a flux of CO{sub 2} with Mg chloride solution at 20 {+-} 2 deg. C. The reaction rate is rapid, with carbonate deposition almost complete in about 10 min. The full characterization of the product of synthesis has been performed to investigate its potential role as a 'CO{sub 2}-sequestering medium' and a means of disposing Mg-rich wastewater. We investigated the nesquehonite synthesized using SEM, XRD, FTIR and thermal analysis. The thermodynamic and chemical stability of this low-temperature hydrated carbonate of Mg and its possible transformation products make our method a promising complementary solution to other methods of CO{sub 2} sequestration. Carbonation via magnesium chloride aqueous solutions at standard conditions represents a simple and permanent method of trapping CO{sub 2}. It could be applied at point sources of CO{sub 2} emission and could involve rejected brine from desalination plants and other saline aqueous wastes (i.e., 'produced water'). The likelihood of using the resulting nesquehonite and the by-products of the process in a large number of applications makes our method an even more attractive solution.

  9. Chloride removal from vitrification offgas

    International Nuclear Information System (INIS)

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

  10. Transcriptome and membrane fatty acid analyses reveal different strategies for responding to permeating and non-permeating solutes in the bacterium Sphingomonas wittichii

    Directory of Open Access Journals (Sweden)

    Johnson David R

    2011-11-01

    Full Text Available Abstract Background Sphingomonas wittichii strain RW1 can completely oxidize dibenzo-p-dioxins and dibenzofurans, which are persistent contaminants of soils and sediments. For successful application in soil bioremediation systems, strain RW1 must cope with fluctuations in water availability, or water potential. Thus far, however, little is known about the adaptive strategies used by Sphingomonas bacteria to respond to changes in water potential. To improve our understanding, strain RW1 was perturbed with either the cell-permeating solute sodium chloride or the non-permeating solute polyethylene glycol with a molecular weight of 8000 (PEG8000. These solutes are assumed to simulate the solute and matric components of the total water potential, respectively. The responses to these perturbations were then assessed and compared using a combination of growth assays, transcriptome profiling, and membrane fatty acid analyses. Results Under conditions producing a similar decrease in water potential but without effect on growth rate, there was only a limited shared response to perturbation with sodium chloride or PEG8000. This shared response included the increased expression of genes involved with trehalose and exopolysaccharide biosynthesis and the reduced expression of genes involved with flagella biosynthesis. Mostly, the responses to perturbation with sodium chloride or PEG8000 were very different. Only sodium chloride triggered the increased expression of two ECF-type RNA polymerase sigma factors and the differential expression of many genes involved with outer membrane and amino acid metabolism. In contrast, only PEG8000 triggered the increased expression of a heat shock-type RNA polymerase sigma factor along with many genes involved with protein turnover and repair. Membrane fatty acid analyses further corroborated these differences. The degree of saturation of membrane fatty acids increased after perturbation with sodium chloride but had the

  11. Elution of zinc in dust discharged from electric arc furnace in carbonic acid solution

    International Nuclear Information System (INIS)

    The dust discharged from an electric arc furnace (EAF) is a valuable resource of zinc. As a fundamental study of extraction of zinc, iron and chlorine in the EAF dust, the elution behavior of them in carbonic acid solution was studied. The influence of the weight of the EAF dust on the elution behavior was examined in this study. Experiment was carried out putting the EAF dust from 1 g to 200 g in weight into 1 L of water that was introduced by CO2. Generally, the pH in the aqueous solution increased with an increase in weight of the additive EAF dust. Maximums of the eluted concentrations of zinc and chloride ion increased with an increase in the weight of the additive EAF dust whereas the extraction ratios of both of them decreased with an increase in the weight of the additive EAF dust. Iron in the EAF dust remained in the dust without elution. The limit of extraction of zinc from the EAF dust to water was given by the solubilities of ZnFe2O4 and ZnO expressed by eq. (6) and eq. (9) respectively.

  12. Elution of zinc in dust discharged from electric arc furnace in carbonic acid solution

    Science.gov (United States)

    Yokoyama, S.; Sasaki, T.; Sasano, J.; Izaki, M.

    2012-03-01

    The dust discharged from an electric arc furnace (EAF) is a valuable resource of zinc. As a fundamental study of extraction of zinc, iron and chlorine in the EAF dust, the elution behavior of them in carbonic acid solution was studied. The influence of the weight of the EAF dust on the elution behavior was examined in this study. Experiment was carried out putting the EAF dust from 1 g to 200 g in weight into 1 L of water that was introduced by CO2. Generally, the pH in the aqueous solution increased with an increase in weight of the additive EAF dust. Maximums of the eluted concentrations of zinc and chloride ion increased with an increase in the weight of the additive EAF dust whereas the extraction ratios of both of them decreased with an increase in the weight of the additive EAF dust. Iron in the EAF dust remained in the dust without elution. The limit of extraction of zinc from the EAF dust to water was given by the solubilities of ZnFe2O4 and ZnO expressed by eq. (6) and eq. (9) respectively.

  13. Carboxylic acid terminated, solution exfoliated graphite by organic acylation and its application in drug delivery

    Indian Academy of Sciences (India)

    KOUSHIK BHOWMIK; AMRITA CHAKRAVARTY; U MANJU; GOUTAM DE; ARNAB MUKHERJEE

    2016-09-01

    Graphite nanosheets are considered as a promising material for a range of applications from flexible electronics to functional nanodevices such as biosensors, intelligent coatings and drug delivery. Chemical functionalizationof graphite nanosheets with organic/inorganic materials offers an alternative approach to control the electronic properties of graphene, which is a zero band gap semiconductor in pristine form. In this paper, we report the aromatic electrophilic substitution of solution exfoliated graphite nanosheets (SEGn). The highly conjugated π-electronic system of graphite nanosheets enable it to have an amphiphilic characteristic in aromatic substitution reactions. The substitution was achieved through Friedel–Crafts (FC) acylation reaction under mild conditions using succinic anhydride as acylating agent and anhydrous aluminum chloride as Lewisacid. Such reaction renders towards the carboxylic acid terminated graphite nanosheets (SEGn–FC) that usually requires harsh reaction conditions. The product thus obtained was characterized using various spectroscopicand microscopic techniques. Highly stable water-dispersed sodium salt of carboxylic acid terminated graphite nanosheets (SEGn–FC-Na) was also prepared. A comparative sheet-resistance measurements of SEGn, SEGn–FC and SEGn–FC-Na were also done. Finally, the anticancer drug doxorubicin (DOX) was loaded on water dispersible SEGn–FC-Na with a loading capacity of 0.266 mg mg−1 of SEGn–FC-Na and the release of DOX from this water-soluble DOX-loaded SEGn–FC-Na at two different temperatures was found to be strongly pHdependent.

  14. Electrochemical Studies of Lead Telluride Behavior in Acidic Nitrate Solutions

    Directory of Open Access Journals (Sweden)

    Rudnik E.

    2015-04-01

    Full Text Available Electrochemistry of lead telluride stationary electrode was studied in nitric acid solutions of pH 1.5-3.0. E-pH diagram for Pb-Te-H2O system was calculated. Results of cyclic voltammetry of Pb, Te and PbTe were discussed in correlation with thermodynamic predictions. Anodic dissolution of PbTe electrode at potential approx. -100÷50 mV (SCE resulted in tellurium formation, while above 300 mV TeO2 was mainly produced. The latter could dissolve to HTeO+2 under acidic electrolyte, but it was inhibited by increased pH of the bath.

  15. Photodegradation of α-naphthaleneacetic acid in aqueous solution

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Kinetic processes of α-naphthaleneacetic acid (NAA) photolysis were studied under different conditions. The results showed that the ultraviolet light was more effective than fluorescent light in promoting degradation, and the degradation of NAA under ultraviolet light followed the first order kinetics with the photolysis rate constant of 1.15 x 10-2 min-1 and half-life time (t1/2) of 60 min. Further, it was proved that the photolysis rate was higher in the presence of oxygen, titanium dioxide (TiO2), and low pH ( acidic solution). At last, two photolysis intermediates were identified by GC-MS and possible photolysis pathways were proposed.

  16. Temperature Induced Aggregation and Clouding in Humic Acid Solutions

    Directory of Open Access Journals (Sweden)

    Leah Shaffer

    2015-01-01

    Full Text Available Humic acids in aqueous solution demonstrate inverse temperature-solubility relationships when solution conditions are manipulated to reduce coulombic repulsion among the humic polyanions. These effects were followed by dynamic light scattering (DLS measurements of the resulting aggregates, as well as the addition of a polarity sensitive fluorescent probe (pyrene. The humic solutions could be primed for temperature induced clouding by carefully lowering the pH to a point where hydration effects became dominant. The exact value of the cloud point (CP was a function of both pH and humate concentration. The CPs mostly lay in the range 50–90°C, but DLS showed that temperature induced aggregation proceeded from approximately 30°C onward. Similar effects could be achieved by adding multivalent cations at concentrations below those which cause spontaneous precipitation. The declouding of clouded humate solutions could be affected by lowering the temperature combined with mechanical agitation to disentangle the humic polymers.

  17. A study of the IR spectra of the copigments of malvin chloride with organic acids

    Directory of Open Access Journals (Sweden)

    ZORAN P. NEDIC

    2001-07-01

    Full Text Available The infrared spectra of the copigments of malvin with several organic acids: caffeic, ferulic, sinapic, chlorogenic, and tannic, were analyzed in order to elucidate the bonding of the molecules in the copigments. It was established that copigmentation is realized through hydrogen bonding between malvin molecules and the acids under study. The infrared spectra reveal that two groups of hydrogen bonds are formed, which include interactions of different molecular structures: hydroxy groups (bands around 3500 cm–1 and oxonium ions of the molecules (bands below 3000 cm–1. The formed hydrogen bonds were found to be of different strengths. The strengths of the hydrogen bonds were tentatively correlated with thermodynamic properties of the corresponding copigmentation reactions.

  18. Structure of early actinides(V) in acidic solutions

    Energy Technology Data Exchange (ETDEWEB)

    Di Giandomenico, M.V.; Le Naour, C.; Simoni, E. [CNRS/Univ. Paris-Sud, Inst. de Physique Nucleaire, Orsay (France); Guillaumont, D.; Moisy, P.; Den Auwer, C. [CEA Marcoule, DHN/DRCP/SCPS, Bagnols sur Ceze (France); Hennig, C. [Forschungszentrum Rossendorf, Dresden (Germany); Conradson, S.D. [Los Alamos National Lab., Los Alamos, NM (United States)

    2009-07-01

    Protactinium occupies a key position in the actinide series between thorium and uranium. In aqueous acidic solution, it is stable at oxidation state (V), occurring either as an oxocation or as a naked ion, depending on the media. Very few structural information on the hydration sphere of Pa(V) in acidic medium is available, in particular in hydrofluoric acid. Combined EXAFS and theoretical calculations have been used in this work to characterize the protactinium coordination sphere at various HF concentrations. The correlation of the XAFS data with quantum chemical calculations provides complementary structural and electronic models from ab initio techniques. At HF concentrations from 0.5 to 0.05 M, both theoretical calculations and EXAFS data suggest that the protactinium coordination sphere is mainly composed of fluoride ions. At the lowest HF concentration, the occurrence of a monooxo bond is observed with EXAFS, in agreement with the literature. A comparison of these data with related neptunium(V) and plutonium(V) diooxocations in perchloric acid is also presented. (orig.)

  19. Structure of early actinides(V) in acidic solutions

    International Nuclear Information System (INIS)

    Protactinium occupies a key position in the actinide series between thorium and uranium. In aqueous acidic solution, it is stable at oxidation state (V), occurring either as an oxocation or as a naked ion, depending on the media. Very few structural information on the hydration sphere of Pa(V) in acidic medium is available, in particular in hydrofluoric acid. Combined EXAFS and theoretical calculations have been used in this work to characterize the protactinium coordination sphere at various HF concentrations. The correlation of the XAFS data with quantum chemical calculations provides complementary structural and electronic models from ab initio techniques. At HF concentrations from 0.5 to 0.05 M, both theoretical calculations and EXAFS data suggest that the protactinium coordination sphere is mainly composed of fluoride ions. At the lowest HF concentration, the occurrence of a monooxo bond is observed with EXAFS, in agreement with the literature. A comparison of these data with related neptunium(V) and plutonium(V) diooxocations in perchloric acid is also presented. (orig.)

  20. Systems solutions by lactic acid bacteria: from paradigms to practice.

    Science.gov (United States)

    de Vos, Willem M

    2011-08-30

    Lactic acid bacteria are among the powerhouses of the food industry, colonize the surfaces of plants and animals, and contribute to our health and well-being. The genomic characterization of LAB has rocketed and presently over 100 complete or nearly complete genomes are available, many of which serve as scientific paradigms. Moreover, functional and comparative metagenomic studies are taking off and provide a wealth of insight in the activity of lactic acid bacteria used in a variety of applications, ranging from starters in complex fermentations to their marketing as probiotics. In this new era of high throughput analysis, biology has become big science. Hence, there is a need to systematically store the generated information, apply this in an intelligent way, and provide modalities for constructing self-learning systems that can be used for future improvements. This review addresses these systems solutions with a state of the art overview of the present paradigms that relate to the use of lactic acid bacteria in industrial applications. Moreover, an outlook is presented of the future developments that include the transition into practice as well as the use of lactic acid bacteria in synthetic biology and other next generation applications.

  1. Adsorption of organic acids from dilute aqueous solution onto activated carbon

    Energy Technology Data Exchange (ETDEWEB)

    Wang, S.W.

    1980-06-01

    The radioisotope technique was used to study the removal of organic acid contaminants from dilute aqueous solutions onto activated carbon. Acetic acid, propionic acid, n-butyric acid, n-hexanoic acid and n-heptanoic acid were studied at 278, 298, and 313/sup 0/K. Three bi-solute acid mixtures (acetic and propionic acids, acetic and butanoic acids, and propionic and butanoic acids) were studied at 278 and 298/sup 0/K. Isotherms of the single-solute systems were obtained at three different temperatures in the very dilute concentration region (less than 1% by weight). These data are very important in the prediction of bi-solute equilibrium data. A Polanyi-based competitive adsorption potential theory was used to predict the bi-solute equilibrium uptakes. Average errors between calculated and experimental data ranges from 4% to 14%. It was found that the competitive adsorption potential theory gives slightly better results than the ideal adsorbed solution theory.

  2. OXIDATIVE STRESS IN SHEEP INDUCED BY CADMIUM CHLORIDE TOXICITY, WITH THERAPEUTIC EFFECTS OF ALPHA LIPOIC ACID

    OpenAIRE

    Hussien Ali NAJI; Mohammad Mushgil ZENAD

    2015-01-01

    Cadmium (Cd) is a heavy toxic metal, with harmful effects on animals and public health. Recently the risk of cadmium toxicity is substantially regarded; the environmental pollution is increased due to multi- uses of this element in various industries. This study was performed to clarify the effects of acute cadmium toxicity in sheep with trail of using alpha lipoic acid as an antioxidant therapeutic substance. Fifteen male lambs aged from 5-to-7 months were divided equally in to three groups,...

  3. Oxydesulfurization of coal by acidic iron sulfate solutions

    Energy Technology Data Exchange (ETDEWEB)

    Mixon, D.A.; Vermeulen, T.

    1981-08-01

    To facilitate by-product recovery and eliminate elemental sulfur formation in coal oxydesulfurization, high-sulfur bituminous coal has been treated with aqueous ferric sulfate/sulfuric acid and oxygen at 100 to 150/sup 0/C. The rate of pyrite oxidation increases with oxygen partial pressure, temperature, and fineness of grinding. This reaction rate is relatively insensitive to sulfuric acid and ferric sulfate concentrations, so that pyrite removal may be satisfactorily performed in solutions containing 25% H/sub 2/SO/sub 4/ and 12% Fe/sub 2/(SO/sub 4/)/sub 3/ (weight percentages relative to total H/sub 2/O plus H/sub 2/SO/sub 4/); preliminary data suggest that such a leaching solution is only mildly corrosive to T316 stainless steel, at 150/sup 0/C or below, in the presence of oxygen. To provide an accurate assessment of coal oxydesulfurization stoichiometry, an analytical technique based on uv spectrophotometry has been developed for the determination of elemental sulfur in coal. Prepared coal samples are extracted for 24 hours with cyclohexane. Other exploratory oxydesulfurization runs have shown that vanadium oxides are not effective catalysts at 100/sup 0/C, with oxygen. Nor are lauryl sulfate or sulfates of zinc, copper, or manganese effective additives in the ferric sulfate/sulfuric acid/oxygen system at 150/sup 0/C. Elemental chlorine has been shown to be capable of removing significant amounts of organic sulfur from coal, at 74/sup 0/C, but suffers the drawback of chlorinating the coal's orgaic matrix. Hydrogen peroxide in aqueous sulfuric acid is an effective reagent for pyrite removal at 100/sup 0/C, but is unduly expensive.

  4. Polymerization of 10,16-dihydroxyhexadecanoic acid, main monomer of tomato cuticle, using the Lewis acidic ionic liquid choline chloride.2ZnCl2

    Directory of Open Access Journals (Sweden)

    Mayra Beatriz eGómez-Patiño

    2015-11-01

    Full Text Available 10,16-dihydroxyhexadecanoic acid, main monomer of the tomato cuticle obtained from agro-residual wastes, was polymerized using (choline chloride.2ZnCl2 ionic liquid as catalyst at three different temperatures (80, 90 and 100 °C. The resulting polyesters obtained under these conditions were insoluble in most of the organic solvents and showed different physicochemical properties. While at 80 °C polymers were obtained as powder, at higher temperature they were found in viscous consistency. According with the CP MAS 13C NMR and FTIR-ATR analysis, polymers showed a linear structure with an increasing degree of esterification in position C-10. Polyesters were analyzed by means of differential scanning calorimetry (DSC, atomic force microscopy (AFM and X ray diffraction (small- and wide-angle scattering, SWAXS techniques.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-12-01

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

  6. Thick pure palladium film with varied crystal structure electroless deposited from choline chloride–palladium chloride solution without the addition of reductant

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yurong; Li, Wei; Wang, Wenchang [School of Petrochemical Engineering, Key Laboratory of Fine Petrochemicals of Jiangsu Province, Changzhou University, Changzhou 213164 (China); Mitsuzak, Naotoshi [Qualtec Co., Ltd, Osaka 590-0906 (Japan); Bao, Weiliang [Department of Chemistry, Zhejiang University, Hanghzou 310058 (China); Chen, Zhidong, E-mail: chen13775646759@hotmail.com [School of Petrochemical Engineering, Key Laboratory of Fine Petrochemicals of Jiangsu Province, Changzhou University, Changzhou 213164 (China); School of Material Science and Engineering, Jiangsu Key Laboratory of Material Surface Technology, Changzhou University, Changzhou 213164 (China)

    2015-07-01

    Immersion deposition procedure was applied to achieve thick pure palladium films with thickness up to about 3 μm from choline chloride (ChCl)–palladium chloride (PdCl{sub 2}) aqueous solution without addition of reductant at 60 °C. Using X-ray diffraction and scanning electron microscope, it was confirmed that Pd films with different crystal orientations and morphology were obtained just by varying the immersion time, and Pd (111) crystal orientation predominated over other crystal orientations during the initial deposition procedure, while (220) conquered (111) about 45 min later. ChCl performing as a reductant facilitated the growth of thick Pd film free of reductant. The immersion deposition of Pd followed the mechanism of replacement reaction accompanying with autocatalyzed reaction and autocatalyzed reaction predominating over replacement reaction. The results revealed that Pd films prepared from ChCl–PdCl{sub 2} solution had excellent properties on solderability and corrosion resistance. - Highlights: • Thick pure Pd film was obtained from ChCl–PdCl{sub 2} aqueous solution without reductant. • Different crystal orientations and morphology of Pd films were achieved. • Immersion time determined the morphology of Pd films. • The mechanism of sustained deposition of Pd on Ni–P surface was deduced.

  7. The environment-induced cracking of as-annealed Ni3(Si,Ti) and Ni3(Si,Ti) with 2Mo in sodium chloride solutions

    OpenAIRE

    Priyotomo, Gadang; Wagle, Sanat; Okitsu, Kenji; Iwase, Akihiro; Kaneno, Yasuyuki; Nishimura, Rokuro; Takasugi, Takayuki

    2015-01-01

    Background The environment-induced cracking (EIC) of as-annealed Ni3(Si,Ti) and Ni3(Si,Ti) with 2Mo has been researched as functions of applied stress, chloride ion concentration, test temperature, and pH. Methods The investigation of EIC was carried out by applying a constant method in NaCl solutions. Results The EIC susceptibility of both intermetallic compounds increased with increasing test temperature and Cl− ion concentration and increased with decreasing pH. The fra...

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

    Directory of Open Access Journals (Sweden)

    Brahman Dhiraj

    2014-01-01

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

  9. OXIDATIVE STRESS IN SHEEP INDUCED BY CADMIUM CHLORIDE TOXICITY, WITH THERAPEUTIC EFFECTS OF ALPHA LIPOIC ACID

    Directory of Open Access Journals (Sweden)

    Hussien Ali NAJI

    2015-09-01

    Full Text Available Cadmium (Cd is a heavy toxic metal, with harmful effects on animals and public health. Recently the risk of cadmium toxicity is substantially regarded; the environmental pollution is increased due to multi- uses of this element in various industries. This study was performed to clarify the effects of acute cadmium toxicity in sheep with trail of using alpha lipoic acid as an antioxidant therapeutic substance. Fifteen male lambs aged from 5-to-7 months were divided equally in to three groups, they were supplied with ordinary diet and provided with water ad-lib, the first group 1 was administered a single dose of CdCl2 3 mg/kg.bw subcutaneously (S/C, the second group 2 was injected with the same dose of CdCl2 and by the same route, and then simultaneously administered an alpha lipoic acid 50 mg/kg.bw intramuscularly, the later drug was repeated after 12 hours via the same route. The third group 3 was left as control and given normal saline (S/C. All animals were daily monitored and the clinical signs were recorded. The signs of cadmium toxicity appeared 18 hours post CdCl2 administration in the group 1; the signs were gradually increased in severity and multiple systems were involved included: digestive disturbances, cardiovascular and neurological dysfunctions, and locomotors abnormalities. Significant elevations in the body temperature, respiratory and heart rates were observed, deaths of 2 lambs were recorded 96 hours post CdCl2 injection. The group 2 showed mild clinical signs, and no death was occurred, moreover insignificant variations between clinical parameters in both groups 2 and 3 were recorded. Serum biochemical analysis revealed significant (P<0.05 increased of malondialdehyde (5.41 ± 0.282 μmol/L and glutathione (10.68 ± 0.38 μmol/L concentrations and marked elevation of serum catalase activity (103.85 ± 3.93 u/L was also observed in group I, whereas the last three parameters showed no significant differences between groups 2

  10. Corrosion resistance of flaky aluminum pigment coated with cerium oxides/hydroxides in chloride and acidic electrolytes

    Science.gov (United States)

    Niroumandrad, S.; Rostami, M.; Ramezanzadeh, B.

    2015-12-01

    The objective of this study was to enhance the corrosion resistance of lamellar aluminum pigment through surface treatment by cerium oxides/hydroxides. The surface composition of the pigments was studied by energy-dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). The corrosion resistance of the pigment was evaluated by conventional hydrogen evolution measurements in acidic solution and electrochemical impedance spectroscopy (EIS) in 3.5% NaCl solution. Results showed that the Ce-rich coating composed of Ce2O3 and CeO2 was precipitated on the pigment surface after immersion in the cerium solution. The corrosion resistance of pigment was significantly enhanced after modification with cerium layer.

  11. Efficient hydrolysis of cellulose over a magnetic lignin-derived solid acid catalyst in 1-butyl-3-methylimidazolium chloride

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Lei; Wu, Zhen; Xu, Jiaxing; Zhou, Shouyong; Tang, Guodong [Huaiyin Normal University, Huaian (China)

    2016-04-15

    A green and efficient strategy for the hydrolysis of cellulose was developed by using a magnetic lignin-derived solid acid catalyst (MLC-SO{sub 3}H) in the presence of ionic liquid 1-butyl-3-methylimidazolium chloride ([BMIM]Cl). The results indicated that reaction temperature, reaction time, catalyst loading and water content have a big influence on the yield of total reducing sugars (TRS). By optimizing these reaction parameters, 69.3% TRS yield was observed at 140 .deg. C for 150 min with the addition of 40 wt% MLC-SO{sub 3}H and 1 wt% water. More importantly, MLC-SO{sub 3}H could be easily separated from the reaction mixture with an external magnet and could be repeatedly used five times without an obvious loss of catalytic activity, demonstrating that it possessed excellent recyclability. Furthermore, a plausible mechanism involving three consecutive processes of dissolution, adsorption and catalysis for the hydrolysis of cellulose in [BMIM]Cl over a catalyst of MLC-SO{sub 3}H was also proposed.

  12. Dissolution of metal oxides in an acid-saturated ionic liquid solution and investigation of the back-extraction behaviour to the aqueous phase

    OpenAIRE

    Wellens, Sil; Vander Hoogerstraete, Tom; Möller, Claudia; Thijs, Ben; Luyten, Jan; Binnemans, Koen

    2014-01-01

    The dissolution of metal oxides in an acid-saturated ionic liquid, followed by selective stripping of the dissolved metal ions to an aqueous phase is proposed as a new ionometallurgical approach for the processing of metals in ionic liquids. The hydrophobic ionic liquid trihexyl(tetradecyl)phosphonium chloride (Cyphos IL 101) saturated with a concentrated aqueous hydrochloric acid solution was used to dissolve CaO, NiO, MnO, CoO, CuO, ZnO and Fe2O3. It was found that nickel(II) and calcium...

  13. Standard Enthalpies of Formation for Solid Complexes of Chromium Chloride with L-α-Amino Acids

    Institute of Scientific and Technical Information of China (English)

    YANG,Xu-Wu(杨旭武); CHEN,San-Ping(陈三平); GAO,Sheng-Li(高胜利); SHI,Qi-Zhen(史启祯)

    2002-01-01

    The solid complexes of Cr(AA)2Cl3@ nH2O of CrCl3 with L-α-amino acids (AA= Val, Leu, Thr, Met, Arg, Phe, Try and His) have been prepared in 95% EtOH medium, and characterized structurally by elemental analysis, chemical analysis, IR spectra and TG-DTG. The constant-volume combustion energies of the complexes have been determined by RBC-H type rotating-bomb calorimeter. The standard enthalpies of formation of the complexes have been calculated as well, which are (-2543.16 ± 3.71) (Val), ( -2561.32 ± 4.06) (Leu),(-2284.02 ± 2.95) (Thr), ( -1418.77 ± 4.60) (Met),(-3218.91 ± 4.67) (Arg), ( -2643.90 ± 5.02) (Phe),(-1707.18±3.23) (Try) and ( -2838.05 ±3.45) (His) kJ/mol, respectively.

  14. INTERACTION OF AQUEOUS SOLUTIONS OF CHLORINE WITH MALIC ACID, TARTARIC ACID, AND VARIOUS FRUIT JUICES, A SOURCE OF MUTAGENS

    Science.gov (United States)

    The interactions of aqueous solutions of chlorine with some fruit acids (citric acid, DL-malic acid, and L-tartaric acid) at different pH values were studied. iethyl ether extraction followed by GC/MS analysis indicated that a number of mutagens (certain chlorinated propanones an...

  15. Changes in humic acid conformation during coagulation with ferric chloride: implications for drinking water treatment.

    Science.gov (United States)

    Siéliéchi, J-M; Lartiges, B S; Kayem, G J; Hupont, S; Frochot, C; Thieme, J; Ghanbaja, J; d'Espinose de la Caillerie, J B; Barrès, O; Kamga, R; Levitz, P; Michot, L J

    2008-04-01

    Electrophoretic mobility, pyrene fluorescence, surface tension measurements, transmission electron microscopy on resin-embedded samples, and X-ray microscopy (XRM) were combined to characterize the aggregates formed from humic colloids and hydrolyzed-Fe species under various conditions of pH and mixing. We show that, at low coagulant concentration, the anionic humic network is reorganized upon association with cationic coagulant species to yield more compact structures. In particular, spheroids about 80nm in size are evidenced by XRM at pH 6 and 8 just below the optimal coagulant concentration. Such reorganization of humic colloids does not yield surface-active species, and maintains negative functional groups on the outside of humic/hydrolyzed-Fe complex. We also observe that the humic network remains unaffected by the association with coagulant species up to the restabilization concentration. Upon increasing the coagulant concentration, restructuration becomes limited: indeed, the aggregation of humic acid with hydrolyzed-Fe species can be ascribed to a competition between humic network reconformation rate and collision rate of destabilized colloids. A decrease in stirring favors the shrinkage of humic/hydrolyzed-Fe complexes, which then yields a lower sediment volume. Elemental analyses also reveal that the iron coagulant species are poorly hydrolyzed in the destabilization range. This suggests that destabilization mechanisms such as sweep flocculation or adsorption onto a hydroxyde precipitate are not relevant to our case. A neutralization/complexation destabilization mechanism accompanied by a restructuration of flexible humic network is then proposed to occur in the range of pHs investigated. PMID:18155268

  16. Optical properties of chitosan in aqueous solution of L- and D-ascorbic acids

    Science.gov (United States)

    Malinkina, Olga N.; Shipovskaya, Anna B.; Kazmicheva, Olga F.

    2016-04-01

    The optical properties of aqueous chitosan solutions in L- and D-ascorbic acids were studied by optical rotatory dispersion and spectrophotometry. The specific optical rotation [α] of all chitosan solutions tested was positive, in contrast to aqueous solutions of the ascorbic acid enantiomers, which exhibit an inverse relationship of [α] values. Significant differences in the absolute values of [α] of the chitosan solutions at polymer-acid ratios exceeding the equimolar one were found.

  17. Henry’s constants and activity coefficients of some organic solutes in 1-butyl,3-methylimidazolium hydrogen sulfate and in 1-methyl,3-trimethylsilylmethylimidazolium chloride

    International Nuclear Information System (INIS)

    Highlights: ► New solubility data are reported for two ionic liquids. ► Density data are reported. ► Thermo-gravimetric analysis data are obtained. - Abstract: Using a customized capillary gas–liquid chromatography column, Henry’s constants and activity coefficients at infinite dilution are reported for benzene, toluene, ethyl acetate, 1,4-dioxane, 1,2-dimethoxyethane, acetonitrile, nitromethane, tetrahydrofuran, chloroform, methanol, ethanol, and 1-propanol in ionic liquids 1-butyl,3-methylimidazolium hydrogen sulfate [BMIM][HSO4] and 1-methyl,3-trimethylsilylmethylimidazolium [SiMIM][Cl] chloride from 313 to 413 K. These acidic ionic liquids may provide suitable media for acid-catalyzed chemical reactions.

  18. Study of the Dissolution of Chalcopyrite in Sulfuric Acid Solutions Containing Alcohols and Organic Acids

    International Nuclear Information System (INIS)

    Chalcopyrite dissolution under environmental conditions has been one of the major challenges facing researchers. The current processes for obtaining copper have pollution issues, which will severely limit their application as environmental controls become stricter. Faced with this problem, a number of eco-friendlier methods, such as GALVANOX and HydroCopper (Outokumpu), have been proposed, although they have not been industrialized, mainly due to their high operating costs. The authors previously proposed an alternative system to leach chalcopyrite, which is based on the use of aqueous polar organic solutions. In the process, copper extraction increases in mixtures of acetone or ethylene glycol with aqueous sulfuric acid solutions. The drawback is the large concentration of oxidizing agents needed to obtain high percentages of chalcopyrite dissolution, which can make the process lose viability. In this investigation, the effect of acetic acid, formic acid, methanol and ethanol, whose chemical characteristics are similar to those previously proposed, were evaluated by cyclic voltammetry. It was found that, in the presence of these organic solvents, higher electrochemical responses were obtained compared with those found with sulfuric acid alone, a similar behavior to that obtained with acetone. Leaching experiments results coincided with the corresponding findings of the electrochemical study and X-ray diffraction results provided evidence to support the proposed reactions

  19. Deprotonation of salicylic acid and 5-nitrosalicylic acid in aqueous solutions of ethanol

    Directory of Open Access Journals (Sweden)

    Faraji Mohammad

    2011-01-01

    Full Text Available The protonation constant values of two hydroxybenzoic acids (salicylic and 5-nitrosalicylic acid were studied in some water-ethanol solutions using spectrophotometric and potentiometric methods at 25°C and in an ionic strength of 0.1 M sodium perchlorate. The results indicated that the pKa values increase with increasing proportion of ethanol in mixed solvent. The dependence of the protonation constants on the variation of the solvent were correlated by the dielectric constants of the media. Furthermore, for a better understanding of the solvent influence, the obtained results were explained in terms of the Kamlet-Taft parameters α (hydrogen-bond donor acidity, π

  20. Preparation of pure uranyl chloride from crude yellow cake

    International Nuclear Information System (INIS)

    A process is described for the preparation of pure uranyl chloride solution from crude yellow cake. The process involves dissolution of the latter in hydrochloric acid followed by uranium extraction using TBP-kerosene mixture. A series of experiments were carried out in order to determine the optimum conditions for both the dissolution and the extraction steps

  1. Chloride binding of cement-based materials subjected to external chloride environment - A review

    OpenAIRE

    Yuan, Q.; Shi, C; Schutter, G. de; Audenaert, K.; Deng, D.

    2009-01-01

    This paper reviews the chloride binding of cement-based materials subjected to external chloride environments. Chloride ion exist either in the pore solution, chemically bound to the hydration products, or physically held to the surface of the hydration products. Chloride binding of cement-based material is very complicated and influenced by many factors, such as chloride concentration, cement composition, hydroxyl concentration, cation of chloride salt, temperature, supplementary cementing m...

  2. 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

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

    International Nuclear Information System (INIS)

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

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

    CERN Document Server

    Bellesia, Giovanni

    2013-01-01

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

  5. Synthesis, magnetic and spectral studies of lanthanide(III) chloride complexes of hydrazones of isonicotinic acid hydrazide

    International Nuclear Information System (INIS)

    The synthesis, magnetic and spectral properties of trivalent lanthanide chlorides with N-isonicotinamidobenzalaldimine (INH-BENZ), N-isonicotinamidoanisalaldimine (INH-ANSL) and N-isonicotinamido-p-dimethylaminobenzalaldimine (INH-PDAB) are described. 13 refs., 2 tabs

  6. Microwave and infrared spectra, adjusted r0 structural parameters, conformational stabilities, vibrational assignments, and theoretical calculations of cyclobutylcarboxylic acid chloride.

    Science.gov (United States)

    Klaassen, Joshua J; Darkhalil, Ikhlas D; Deodhar, Bhushan S; Gounev, Todor K; Gurusinghe, Ranil M; Tubergen, Michael J; Groner, Peter; Durig, James R

    2013-08-01

    The FT-microwave spectrum of cyclobutylcarboxylic acid chloride, c-C4H7C(O)Cl, has been recorded and 153 transitions for the (35)Cl and (37)Cl isotopologues have been assigned for the gauche-equatorial (g-Eq) conformation. The ground state rotational constants were determined for (35)Cl [(37)Cl]: A = 4349.8429(25) [4322.0555(56)] MHz, B = 1414.8032(25) [1384.5058(25)] MHz, and C = 1148.2411(25) [1126.3546(25)] MHz. From these rotational constants and ab initio predicted parameters, adjusted r0 parameters are reported with distances (Å) rCα-C = 1.491(4), rC═O = 1.193(3), rCα-Cβ = 1.553(4), rCα-Cβ' = 1.540(4), rCγ-Cβ = 1.547(4), rCγ-Cβ' = 1.546(4), rC-Cl = 1.801(3) and angles (deg) τCγCβCβ'Cα = 30.9(5). Variable temperature (-70 to -100 °C) infrared spectra (4000 to 400 cm(-1)) were recorded in liquid xenon and the g-Eq conformer was determined the most stable form, with enthalpy differences of 91 ± 9 cm(-1) (1.09 ± 0.11 kJ/mol) for the gauche-axial (g-Ax) form and 173 ± 17 cm(-1) (2.07 ± 0.20 kJ/mol) for the trans-equatorial (t-Eq) conformer. The relative amounts at ambient temperature are 54% g-Eq, 35 ± 1% g-Ax, and 12 ± 1% t-Eq forms. Vibrational assignments have been provided for the three conformers and theoretical calculations were carried out. The results are discussed and compared to corresponding properties of related molecules.

  7. Influence of salicylic acid on rubisco and rubisco activase in tobacco plant grown under sodium chloride in vitro.

    Science.gov (United States)

    Lee, So Young; Damodaran, Puthanveettil Narayanankutty; Roh, Kwang Soo

    2014-11-01

    The present study was designed to evaluate the influence of salicylic acid (SA) on the growth of salt stress (sodium chloride) induced in tobacco plants. In addition, quantification of rubisco and rubisco activase contents of the plants was also determined in treatments with the control, 10(-4) mM SA, 50 mM NaCl, 100 mM NaCl, 150 mM NaCl, SA + 50 mM NaCl, SA + 100 mM NaCl and SA + 150 mM NaCl, respectively after in vitro culture for 5 weeks. The growth of the tobacco plant decreased in 50 mM and 100 mM NaCl when not treated with SA. However, the growth was accelerated by SA, and the growth retardation caused by NaCl was improved by SA. The content of rubisco was improved by SA only in plants treated with 50 mM NaCl, and the activity of rubisco was increased by SA resulting in the decreased effect of NaCl, but only in 50 mM NaCl treated plants. The content of rubisco activase decreased due to NaCl, and SA did not improve the effect caused by NaCl. The activity of rubisco activase was increased by SA resulting in decreased activity caused by NaCl, but increased effect by SA was not recovered to the level of NaCl untreated plants. The activity of rubisco and rubisco activase, which decreased due to denaturing agents, did not demonstrate significant improvement when compared to the control. PMID:25313276

  8. Interaction of trace elements in acid mine drainage solution with humic acid.

    Science.gov (United States)

    Suteerapataranon, Siripat; Bouby, Muriel; Geckeis, Horst; Fanghänel, Thomas; Grudpan, Kate

    2006-06-01

    The release of metal ions from a coal mining tailing area, Lamphun, Northern Thailand, is studied by leaching tests. Considerable amounts of Mn, Fe, Al, Ni and Co are dissolved in both simulated rain water (pH 4) and 10 mg L(-1) humic acid (HA) solution (Aldrich humic acid, pH 7). Due to the presence of oxidizing pyrite and sulfide minerals, the pH in both leachates decreases down to approximately 3 combined with high sulfate concentrations typical to acid mine drainage (AMD) water composition. Interaction of the acidic leachates upon mixing with ground- and surface water containing natural organic matter is simulated by subsequent dilution (1:100; 1:200; 1:300; 1:500) with a 10 mg L(-1) HA solution (ionic strength: 10(-3) mol L(-1)). Combining asymmetric flow field-flow fractionation (AsFlFFF) with UV/Vis and ICP-MS detection allows for the investigation of metal ion interaction with HA colloid and colloid size evolution. Formation of colloid aggregates is observed by filtration and AsFlFFF depending on the degree of the dilution. While the average HA size is initially found to be 2 nm, metal-HA complexes are always found to be larger. Such observation is attributed to a metal induced HA agglomeration, which is found even at low coverage of HA functional groups with metal ions. Increasing the metal ion to HA ratio, the HA bound metal ions and the HA entities are growing in size from 450 nm. At high metal ion to HA ratios, precipitation of FeOOH phases and HA agglomeration due to colloid charge neutralization by complete saturation of HA complexing sites are responsible for the fact that most of Fe and Al precipitate and are found in a size fraction >450 nm. In the more diluted solutions, HA is more relevant as a carrier for metal ion mobilization. PMID:16631855

  9. U(VI) speciation and reduction in acid chloride fluids in hydrothermal conditions: from transport to deposition of uranium in unconformity-related deposits

    International Nuclear Information System (INIS)

    Circulations of acidic chloride brines in the earth's crust are associated with several types of uranium deposits, particularly unconformity-related uranium (URU) deposits. The spectacular high grade combined with the large tonnage of these deposits is at the origin of the key questions concerning the geological processes responsible for U transport and precipitation. The aim of this work is to performed experimental studies of U(VI) speciation and its reduction to U(IV) subsequently precipitation to uraninite under hydrothermal condition. About uranium transport, the study of U(VI) speciation in acidic brines at high temperature is performed by Raman and XAS spectroscopy, showing the coexistence of several uranyl chloride complexes UO2Cln2-n (n = 0 - 5). From this study, complexation constants are proposed. The strong capability of chloride to complex uranyl is at the origin of the transport of U(VI) at high concentration in acidic chloride brines. Concerning uranium precipitation, the reactivity of four potential reductants under conditions relevant for URU deposits genesis is investigated: H2, CH4, Fe(II) and the C-graphite. The kinetics of reduction reaction is measured as a function of temperature, salinity, pH and concentration of reductant. H2, CH4, and the C-graphite are very efficient while Fe(II) is not able to reduce U(VI) in same conditions. The duration of the mineralizing event is controlled by (i) the U concentration in the ore-forming fluids and (ii) by the generation of gaseous reductants, and not by the reduction kinetics. These mobile and efficient gaseous reductant could be at the origin of the extremely focus and massive character of ore in URU deposits. Finally, first partition coefficients uraninite/fluid of trace elements are obtained. This last part opens-up new perspectives on (i) REE signatures interpretation for a given type of uranium deposit (ii) and reconstruction of mineralizing fluids composition. (author)

  10. Isothermal heat measurements of TBP-nitric acid solutions

    International Nuclear Information System (INIS)

    Net heats of reaction were measured in an isothermal calorimeter for both single phase (organic) and two phase (organic and aqueous) TBP/HNO3 reacting solutions at temperatures above 100 C. The oxidation rate constant was determined to be 5.4E-4 min-1 at 110 C for an open ''vented'' system as compared to 1.33 E-3 min-1 in the closed system. The heat released per unit material oxidized was also reduced. The oxidation in both phases was found to be first order in nitric acid and pseudo-zero order in butylnitrate and water. The hydrolysis (esterification) rate constant determined by Nichols' (1.33E-3 min-1) fit the experimental data from this work well. Forced evaporation of the volatile components by the product gases from oxidation resulted in a cooling mechanism which more than balanced the heat from the oxidation reaction in the two-phased systems. Rate expressions were derived and rate constants determined for both the single and two phase systems. An approximating mathematical model was developed to fit the experimental data and to extrapolate beyond the experimental conditions. This model shows that one foot of ''reacting'' 14.3M HNO3 aqueous phase solution at 121 C will transport sufficient water to the organic phase to replace evaporative losses, maintaining endothermicity, for organic layers up to 12.2 + 6.0 feet deep. If the pressure in a reacting system is allowed to increase due to insufficient venting the temperature of the organic phase would increase in temperature to reach a new equilibrium. The rate of oxidation would increase not only due to the increase in temperature but also from the increased concentration of dissolved HNO3 reduction products. Another important factor is that the cooling system described in this work becomes less effective as the total pressure increases. These factors probably contributed to the explosion at Tomsk

  11. Humic acid removal from aqueous solutions by peroxielectrocoagulation process

    Directory of Open Access Journals (Sweden)

    Ahmad Reza Yazdanbakhsh

    2015-06-01

    Full Text Available Background: Natural organic matter is the cause of many problems associated with water treatment such as the presence of disinfection by-products (DBPs and membrane fouling during water filtration. In this study, the performance of the peroxi-electrocoagulation process (PEP was investigated for the removal of humic acids (HAs from aqueous solutions. Methods: PEP was carried out for the removal of HA using a plexiglas reactor with a volume of 2 L and fitted with iron electrodes and a direct current supply (DC. Samples were taken at various amounts of pH (2-4, current density (1 and 2A/cm2, hydrogen peroxide (50-150 mg/L and reaction time (5-20 minutes and then filtered to remove sludge formed during reaction. Finally, the HA concentration was measured by UV absorbance at 254 nm (UV254. Results: Results indicated that increasing the concentration of H2O2 from 50 to 150 mg/L increased HA removal efficiency from 83% to 94.5%. The highest removal efficiency was observed at pH 3.0; by increasing the pH to the alkaline range, the efficiency of the process was reduced. It was found that HA removal efficiency was high in current density 1A/cm2. Increasing current density up to 1 A cm-2 caused a decrease in removal efficiency. Results of this study showed that under the optimum operating range for the process ([current density] = 1A/cm2, [hydrogen peroxide concentration] = 150 mg/L, [reaction time]= 20 minutes and [pH]= 3.0, HA removal efficiency reached 98%. Conclusion: It can be concluded that PEP has the potential to be utilized for cost-effective removal of HA from aqueous solutions.

  12. Comparison of peak shape in hydrophilic interaction chromatography using acidic salt buffers and simple acid solutions.

    Science.gov (United States)

    Heaton, James C; Russell, Joseph J; Underwood, Tim; Boughtflower, Robert; McCalley, David V

    2014-06-20

    The retention and peak shape of neutral, basic and acidic solutes was studied on hydrophilic interaction chromatography (HILIC) stationary phases that showed both strong and weak ionic retention characteristics, using aqueous-acetonitrile mobile phases containing either formic acid (FA), ammonium formate (AF) or phosphoric acid (PA). The effect of organic solvent concentration on the results was also studied. Peak shape was good for neutrals under most mobile phase conditions. However, peak shapes for ionised solutes, particularly for basic compounds, were considerably worse in FA than AF. Even neutral compounds showed deterioration in performance with FA when the mobile phase water concentration was reduced. The poor performance in FA cannot be entirely attributed to the negative impact of ionic retention on ionised silanols on the underlying silica base materials, as results using PA at lower pH (where their ionisation is suppressed) were inferior to those in AF. Besides the moderating influence of the salt cation on ionic retention, it is likely that salt buffers improve peak shape due to the increased ionic strength of the mobile phase and its impact on the formation of the water layer on the column surface.

  13. A study on the dissolution of uranium compounds(UO2, AUC) in nitric acid solutions

    International Nuclear Information System (INIS)

    The dissolution behavior of UO2 and AUC powder in nitric acid solutions was investigated to evaluate the performance of chemical decontamination process applicable to and internal surface of metallic system components such as tanks and piping in the uranium conversion plant. It was revealed that the dissolution of UO2 in nitric acid solutions containing low concentration of H2O2 was more effective than that in nitric acid solution without H2O2 as one of the conventional inorganic acid decontamination processes. AUC powder dissolved easily and continuously in nitric acid solutions before the solution pH attains about 3, but above that solution pH uranium concentration in the solution was lowered drastically by recrystallization. It was convinced that pH range of 2.5 ∼ 3 is desired in the decontamination of surface contaminated with AUC

  14. Analysis of amino acids by HPLC/electrospray negative ion tandem mass spectrometry using 9-fluorenylmethoxycarbonyl chloride (Fmoc-Cl) derivatization.

    Science.gov (United States)

    Ziegler, Jörg; Abel, Steffen

    2014-12-01

    A new method for the determination of amino acids is presented. It combines established methods for the derivatization of primary and secondary amino groups with 9-fluorenylmethoxycarbonyl chloride (Fmoc-Cl) with the subsequent amino acid specific detection of the derivatives by LC-ESI-MS/MS using multiple reaction monitoring (MRM). The derivatization proceeds within 5 min, and the resulting amino acid derivatives can be rapidly purified from matrix by solid-phase extraction (SPE) on HR-X resin and separated by reversed-phase HPLC. The Fmoc derivatives yield several amino acid specific fragment ions which opened the possibility to select amino acid specific MRM transitions. The method was applied to all 20 proteinogenic amino acids, and the quantification was performed using L-norvaline as standard. A limit of detection as low as 1 fmol/µl with a linear range of up to 125 pmol/µl could be obtained. Intraday and interday precisions were lower than 10 % relative standard deviations for most of the amino acids. Quantification using L-norvaline as internal standard gave very similar results compared to the quantification using deuterated amino acid as internal standards. Using this protocol, it was possible to record the amino acid profiles of only a single root from Arabidopsis thaliana seedlings and to compare it with the amino acid profiles of 20 dissected root meristems (200 μm).

  15. Chloride equilibrium potential in salamander cones

    Directory of Open Access Journals (Sweden)

    Bryson Eric J

    2004-12-01

    Full Text Available Abstract Background GABAergic inhibition and effects of intracellular chloride ions on calcium channel activity have been proposed to regulate neurotransmission from photoreceptors. To assess the impact of these and other chloride-dependent mechanisms on release from cones, the chloride equilibrium potential (ECl was determined in red-sensitive, large single cones from the tiger salamander retinal slice. Results Whole cell recordings were done using gramicidin perforated patch techniques to maintain endogenous Cl- levels. Membrane potentials were corrected for liquid junction potentials. Cone resting potentials were found to average -46 mV. To measure ECl, we applied long depolarizing steps to activate the calcium-activated chloride current (ICl(Ca and then determined the reversal potential for the current component that was inhibited by the Cl- channel blocker, niflumic acid. With this method, ECl was found to average -46 mV. In a complementary approach, we used a Cl-sensitive dye, MEQ, to measure the Cl- flux produced by depolarization with elevated concentrations of K+. The membrane potentials produced by the various high K+ solutions were measured in separate current clamp experiments. Consistent with electrophysiological experiments, MEQ fluorescence measurements indicated that ECl was below -36 mV. Conclusions The results of this study indicate that ECl is close to the dark resting potential. This will minimize the impact of chloride-dependent presynaptic mechanisms in cone terminals involving GABAa receptors, glutamate transporters and ICl(Ca.

  16. Influence of cold work and sigma phase on the pitting corrosion behavior of 25 chromium super duplex stainless steel in 3.5% sodium chloride solution.

    Energy Technology Data Exchange (ETDEWEB)

    Elhoud, A.; Deans, W. [School of Engineering, Kings College, University of Aberdeen (United Kingdom); Ezuber, H. [College of Engineering, University of Bahrain (Bahrain)

    2010-03-15

    The effect of cold work (up to 16% strain) and sigma phase precipitation (at 850 C for 10 and 60 min) on the pitting resistance of 25 chromium super duplex stainless steel were investigated in 3.5% sodium chloride solution at 70 and 90 C. Anodic polarization scans for cold worked samples revealed immunity to pitting attack at 70 C even with 16% strain. At 90 C, the alloy still showed high pitting resistance, pitting occurring at about 600 mV (SCE) for the 16% plastic strain samples. A serious deterioration of the pitting corrosion resistance was found after heating the alloy at 850 C for 10 min resulting in a clear drop in the pitting potential at 90 C. After heating for 60 min, the material showed rapid deterioration of pitting corrosion resistance at 70 C. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  17. Hydrogen oxidation on gold electrode in perchloric acid solution

    Energy Technology Data Exchange (ETDEWEB)

    Sustersic, M.G.; Almeida, N.V.; Von Mengershausen, A.E. [Facultad de Ingenieria y Ciencias Economico Sociales, Universidad Nacional de San Luis, 25 de Mayo N 384, 5730 Villa Mercedes, San Luis (Argentina)

    2010-06-15

    The aim of this research is to study the interface gold/perchloric acid solution in presence of hydrogen. The reactive is generated by H{sup +} ion reduction and by saturating the electrolyte with the gaseous H{sub 2}. No evidence of H{sub 2} dissociative adsorption is found. In special conditions, a strongly adsorbed layer is formed from the atoms diffusing from inside of the metal. The mass transport occurs in three ways: the diffusion of H atoms inwards, the diffusion of H atoms back to the surface and the dissolved H{sub 2} diffusion from the bulk electrolyte to the surface. When dissolved H{sub 2} reacts, the reaction is kinetically controlled when the H{sub 2} partial pressure is high, and it is diffusionally controlled when the reactive partial pressure is low. Above 0.7 V, (measured vs. RHE), the (100) plane surface reconstruction lifts, and the rate determining step is the H diffusion towards inside of the metal, and the current suddenly falls. The Hydrogen redox reaction on gold shows reversibility with respect to the potential when the reactives are the H diffusing outwards of the metal and the H{sup +} ion present in the electrolyte. However, the absolute current values of oxidation and reduction are different because the reactive sources are different. (author)

  18. A new chemical system solution for acid gas removal

    Energy Technology Data Exchange (ETDEWEB)

    Seiler, M.; Rolker, J.; Witthaut, D.; Schulze, S. [Evonik Industries AG, Hanau (Germany); Buchholz, S. [Evonik Industries AG, Marl (Germany)

    2012-07-01

    An energy-efficient absorbent formulation fors eparating acid gases (e.g. CO{sub 2}, H2S) from gas streams such as natural gas, syngas or flue gas is important for a number of industrial applications. In many cases, a substantial share of their costs is driven by the operational expenditure (OPEX) of the CO{sub 2} separation unit. One possible strategy for reducing OPEX is the improvement of the absorbent performance. Although a number of absorbents for the separation of CO{sub 2} from gas streams exist, there is still a need to develop CO{sub 2} absorbents with an improved absorption performance, less corrosion and foaming, no nitrosamine formation, lower energy requirement and therefore less OPEX. This contribution aims at giving a brief state-of-the-art overview followed by an introduction and performance characterization of a new family of amine-based CO{sub 2} absorbents. High cyclic capacities in the range of 2.9 to 3.2 mol CO{sub 2} kg{sup -1} absorbent and low absorption enthalpies of about -30 kJ mol{sup -1} allow for significant savings in the regeneration energy of the new absorbent system. Calculations with the modified Kremser model indicate a reduction in the specific reboiler heat duty of 45 %. Moreover, the high-performance absorbents developed show much lower corrosion rates than state-of-the-art solutions that are currently employed. (orig.)

  19. Isothermal heat measurements of TBP-nitric acid solutions

    International Nuclear Information System (INIS)

    Net heats of reaction were measured in an isothermal calorimeter for TBP/HNO3 solutions at ambient pressure and temperatures above 100 degrees C. Carbon and nitrogen balances were performed giving the reaction stoichiometry. Rate expressions were derived and rate constants determined for both the single and two phase systems which included mass lost from the reacting system by evaporation. This mathematical model was fit to the experimental data (including the measured net heat and off-gas rate) gathered over a wide range of conditions. The oxidation rate constant was determined to be 5.4E-4 min-1 at 110 degrees C for an open open-quotes ventedclose quotes system as compared to >1E-3min-1 in a closed system. The heat released per unit material oxidized was also reduced due to a decrease in dissolved oxidants and an inefficient reduction of HNO3. Oxidation in the organic phase was found to be first order in nitric acid and pseudo-zero order in butylnitrate and water

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-12-01

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

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

    Science.gov (United States)

    Mizuhashi, Toshinari; Asakawa, Tsuyoshi; Ohta, Akio

    2015-01-01

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

  2. Corrosion Inhibition of Mild Steel in Hydrochloric Acid Solution by Amino Acid Complexes

    OpenAIRE

    K. Kiruthikajothi; G. Chandramohan

    2015-01-01

    Using the amino acids methionine and serine reduced Schiff base and their copper(II) complexes were synthesized. The inhibition effect of these copper (II) complexes on the corrosion of mild steel in 1 M HCl solution was investigated. The corrosion inhibition action is studied through weight loss method. Among the tested complexes [CuCl(SMet)PPh3.H2O] exhibited better corrosion inhibition at 3 mmol concentration. The adsorption of the complexes on the metal surface obeys Langmuir’s adsorption...

  3. A comparative electrochemical and quantum chemical calculation study of BTAH and BTAOH as copper corrosion inhibitors in near neutral chloride solution

    International Nuclear Information System (INIS)

    The inhibition of copper corrosion in 3% NaCl solution was studied by using a well-known inhibitor, benzotriazole (BTAH), and its not so extensively explored derivative, 1-hydroxybenzotriazole (BTAOH). Electrochemical methods, i.e., linear polarization, Tafel and potentiodynamic curve measurements and electrochemical quartz crystal microbalance (EQCM) measurements were used. Corrosion parameters and inhibition effectiveness were determined. Experimental results showed that benzotriazole is a more effective inhibitor of the corrosion of copper in chloride media than 1-hydroxybenzotriazole. Whereas in the presence of BTAH a protective Cu-BTA layer is formed on the Cu surface, in the presence of BTAOH a thick, poorly protective layer is formed, which readily dissolves in chloride solution. Kinetic parameters were calculated based on EQCM results. Adsorption of BTAOH follows a linear growth law, in contrast to BTAH, whose film growth can be best represented at first by a parabolic, and later by logarithmic, growth law. Different mechanisms of growth imply different mechanisms of inhibition and account for the different inhibition effectiveness. Density functional theory calculations were performed to characterize certain features of the molecular structures, including the electronic parameters related to the inhibition effectiveness of these inhibitors. Introduction of the -OH group into the benzotriazole molecules does not change their electronic parameters significantly neither in gas phase nor in the presence of water solvent. Other parameters, therefore, affect the inhibition effectiveness of these corrosion inhibitors. In particular, superior inhibition effectiveness of BTAH is attributed to interplay of planar molecular structure, physisorption and intermolecular H-bonding, which cooperatively may result in formation of thin and protective film on the surface

  4. A pulse radiolysis study of salicylic acid and 5-sulpho-salicylic acid in aqueous solutions

    International Nuclear Information System (INIS)

    Reactions of H, OH, eaq- and some one-electron oxidants have been studied with salicylic acid and 5-sulpho-salicylic acid in aqueous solutions. Rate constants for the reaction of eaq- with these compounds were of the order of 109dm3mol-1s-1 and this reaction led to the formation of reducing radicals which could transfer electron to methyl viologen. Other one-electron reductants were not able to reduce these compounds. OH radicals reacted with these compounds by addition pathway with very high rate constants (>1010dm3mol-1s-1) while O- radical anions could oxidize these molecules to give phenoxyl type of radicals. Amongst the one-electron oxidants, only N3 radicals and SO4- radicals could oxidize salicylic acid while 5-sulpho-salicylic acid could be oxidized only by SO4- radicals indicating that while one-electron reduction potential for semi-oxidized SA may beo1 for N3? radical), it is more than 1.33V vs. NHE for semi-oxidized SSA species

  5. Antimicrobial and cytotoxic effects of phosphoric acid solution compared to other root canal irrigants

    OpenAIRE

    PRADO, Maíra; Emmanuel João Nogueira Leal da SILVA; Thais Mageste DUQUE; ZAIA, Alexandre Augusto; Ferraz, Caio Cezar Randi; de Almeida, José Flávio Affonso; GOMES, Brenda Paula Figueiredo de Almeida

    2015-01-01

    Phosphoric acid has been suggested as an irrigant due to its effectiveness in removing the smear layer. Objectives : The purpose of this study was to compare the antimicrobial and cytotoxic effects of a 37% phosphoric acid solution to other irrigants commonly used in endodontics. Material and Methods : The substances 37% phosphoric acid, 17% EDTA, 10% citric acid, 2% chlorhexidine (solution and gel), and 5.25% NaOCl were evaluated. The antimicrobial activity was tested against Candida albican...

  6. Influence of heat treatment on microstructure and passivity of Cu–30Zn–1Sn alloy in buffer solution containing chloride ions

    Indian Academy of Sciences (India)

    U Tabrizi; R Parvizi; A Davoodi; M H Moayed

    2012-02-01

    Tin as an alloying element is of great interest in brasses for dezincification impediment. In this paper, Cu–30Zn–1Sn alloy was submitted to three different heat treatments, viz. A (heating up to 800 °C for 20 h, held at 200 °C for 20 h in salt bath and air cooled), B (heating up to 800 °C for 20 h and water quenched) and C (heating up to 600 °C for 20 h and water quenched). The influence of heat treatment on microstructure was evaluated by OM and SEM–EDS analysis. The corrosion resistance in buffer solution (pH 9), H3BO3/Na2B4O7.10H2O, with various concentrations of chloride ions was evaluated by potentiodynamic polarization curves and compared with multicomponent Pourbaix diagrams. A correlation between the heat treatment, microstructure and passivity of the heat treated samples was observed. The results indicated that all heat treatment procedures led to formation of , and -Sn-rich phases as microstructure constituents with a small fraction of ' phase in A. Sn-rich phase appears in grain boundaries and its morphology was slightly changed due to heat treatment. Beneficial influence of low concentration chloride ions on passivity was associated with the formation of copper oxides/hydroxide and chloride complexes. Deterioration was observed at concentrations higher than 0.05 M NaCl due to accelerated dissolution of copper by formation of CuCl$^{−}_{2}$. As a result of dezincification process, preferential corrosion attack and copper redeposition on phase (matrix) were observed. However, Sn-rich (1) phase in grain boundaries was not attacked due to SnO2 formation. In buffer solution, the higher passivity current density in A was related to the presence of small amount of ' phase. On the other hand, in 1 M NaCl, lower critical current density for passivation in B and A (about two times lower than C) was attributed to the grain size effect.

  7. Investigation of the vapor pressure p of zinc bromide or zinc chloride solutions with methanol by static method

    International Nuclear Information System (INIS)

    Vapor pressures p of ZnBr2 + CH3OH and ZnCl2 + CH3OH solutions at T (298.15 to 323.15) K were measured, activity of solvent a s and osmotic φ coefficients have been evaluated. The experiments were carried out for the ZnBr2 + CH3OH solutions in the molality range m = (0.19972 to 11.05142) mol . kg-1 and for the ZnCl2 + CH3OH solutions in the molality range m (0.42094 to 8.25534) mol . kg-1. The Antoine equation for the empirical description of the experimental vapor pressure results and the Pitzer-Mayorga model with inclusion of ionic strength dependence of the third virial coefficient for the description of calculated osmotic coefficients were used. The parameters of Pitzer-Mayorga model were used for evaluation of activity coefficients

  8. MODIFICATION OF PRECIPITATED CALCIUM CARBONATE FILLER USING SODIUM SILICATE/ZINC CHLORIDE BASED MODIFIERS TO IMPROVE ACID-RESISTANCE AND USE OF THE MODIFIED FILLER IN PAPERMAKING

    Directory of Open Access Journals (Sweden)

    Jing Shen

    2009-11-01

    Full Text Available In order to improve the acid-resistant property of papermaking grade precipitated calcium carbonate filler and to obtain modified filler in powder form, sodium silicate/zinc chloride based modifiers were used in filler modification, and the use of modified filler in papermaking of deinked pulp derived from recycled newspaper was also preliminarily investigated. Under the preliminarily optimized experimental conditions, when sodium silicate, zinc chloride, sodium hexametaphosphate, and phosphoric acid with dosages of 10 wt%, 3 wt%, 1 wt% and 0.2 wt%, respectively, were used as modifiers, and when the temperature, aging time, and PCC concentration during the filler modification process was 70 oC, 7 h and 9.1 wt%, respectively, the acid-resistant property of filler was significantly improved after modification, as evaluated using alum consumption and pH methods. The use of modified precipitated calcium carbonate filler prepared under the optimized conditions provided considerably more brightness and light scattering improvement in comparison to unmodified filler, and filler modification was found to have only negligible influence on tensile and burst strength of the paper, air permeability of the paper, and retention performance of the filler. Surface analysis of the modified filler using XPS and SEM confirmed the occurring of surface encapsulation and modification of precipitated calcium carbonate filler when the relevant modifiers were used in filler modification. The encapsulating effect of modifiers on filler was thought to be favorable to improvement in acid-resistant property, and optical properties of the filled paper.

  9. Application of cyanuric chloride-based six new chiral derivatizing reagents having amino acids and amino acid amides as chiral auxiliaries for enantioresolution of proteinogenic amino acids by reversed-phase high-performance liquid chromatography.

    Science.gov (United States)

    Bhushan, Ravi; Dixit, Shuchi

    2012-04-01

    Six dichloro-s-triazine (DCT) reagents having L-Leu, D-Phg, L-Val, L-Met, L-Ala and L-Met-NH(2) as chiral auxiliaries in cyanuric chloride were introduced for enantioseparation of 13 proteinogenic amino acids. Four other DCTs and six monochloro-s-triazine (MCT) reagents having amino acid amides as chiral auxiliaries were also synthesized. These 16 chiral derivatizing reagents (CDRs) were used for synthesis of diastereomers of all the 13 analytes using microwave irradiation, which were resolved by reversed-phase high-performance liquid chromatography (RP-HPLC) using C18 column and gradient eluting mixture of aqueous TFA and acetonitrile with UV detection at 230 nm. It required only 60-90 s for derivatization using microwave irradiation. Better resolution and lower retention times were observed for the diastereomers prepared with CDRs having amino acids as chiral auxiliaries as compared to counterparts prepared with reagents having amino acid amides as chiral auxiliaries. As the best resolution of all the 13 analytes was observed for their diastereomers prepared using the DCT reagent having L-Leu as chiral auxiliary, this CDR was further employed for derivatization of Lys, Tyr, His and Arg followed by RP-HPLC analysis of resulting diastereomers. The results are discussed in light of acid and amide groups of chiral auxiliaries constituting CDRs, electronegativities of the atoms of achiral moieties constituting CDRs and hydrophobicities of side chains of amino acids constituting CDRs and analytes.

  10. The rare earth element geochemistry of acid-sulphate and acid-sulphate-chloride geothermal systems from Yellowstone National Park, Wyoming, USA

    Science.gov (United States)

    Lewis, Anita J.; Palmer, Martin R.; Sturchio, Neil C.; Kemp, Anthony J.

    1997-02-01

    Rare earth element (REE) concentrations have been determined by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) in acid-sulphate and acid-sulphate-chloride waters and the associated sinters and volcanic rocks from the Yellowstone National Park (YNP), Wyoming, USA, geothermal system. REE concentrations in the volcanic rocks range from 222 to 347 ppm; their chondite-normalised REE patterns are typical of upper continental crust, with LREE > HREE and negative Eu anomalies. Total REE concentrations in the fluids range from 3 to 1133 nmol kg -1 (≥ 162 ppm), and ΣREE concentrations in sinter are ≥ 181 ppm. REE abundances and patterns in drill core material from YNP indicate some REE mobility. Normalisation of REE concentrations in altered Lava Creek Tuff (LCT) from Y-12 drill core to REE concentrations in fresh LCT indicate that the REE overall have been depleted with the exception of Eu, which has been decoupled from the REE series and concentrated in the altered rocks. Relative to the host rocks the REE patterns of the fluids are variably depleted in HREEs and LREEs, and usually have a pronounced positive Eu anomaly. This decoupling of Eu from the REE suite suggests that (1) Eu has been preferentially removed either from the host rock glass or from the host rock minerals, or (2) the waters are from a high temperature or reducing environment where Eu 2+ is more soluble than the trivalent REEs. Since the latter is inconsistent with production of acid-sulphate springs in a low temperature, oxidising near-surface environment, we suggest that the positive Eu anomalies in the fluids result from preferential dissolution of a Eu-rich phase in the host rock. Spatial and temporal variations in major element chemistry and pH of the springs sampled from Norris Geyser Basin and Crater Hills accompany variations in REE concentrations and patterns of individual geothermal springs. These are possibly related to changes in subsurface plumbing, which results in variations in

  11. The analysis of crystallization of sodium chloride from the solution in vacuum crystallizer with the recirculation of the suspension

    Directory of Open Access Journals (Sweden)

    Jotanović Milovan B.

    2009-01-01

    Full Text Available Crystallization from a solution most often is the final stage of many technological processes, and has a major role in bulk chemical industry. Basic requirements which stand before the process of crystallization are as follows: providing a minimum energy use-up together with a maximum specific capacity of the crystallizer, as well as with obtaining a product with the necessary degree of purity. These demands are successfully fulfilled by vacuum crystallizers with recirculation of suspension, which are the most promising apparatus for the crystallization of inorganic salts from solutions in bulk production. Vacuum crystallizers, like other chemical apparatuses, are described as a sum of physical and chemical phenomena which together create a unit process of crystallization of NaCl from water solutions. The term apparatus process unit (APU was introduced and a vacuum crystallizer is described as the sum of APU and shown in a structural scheme. The analysis of the vacuum crystallizer was performed based on its APU component, using theoretical assumptions, the results published as well as the results of researches on models. A particular focus was given to the description of the mass and heat transfer, as well as to the hydrodynamics of fluids in the area where the starting solution and the recircular suspension are mixed, in the circulation channel and the central pipe, as well as in the area of vaporization. This study gives the conclusions made based on the investigation of vacuum crystallizers. .

  12. Effect of citric acid on the acidification of artificial pepsin solution for metacercariae isolation from fish.

    Science.gov (United States)

    Kim, Min-Ki; Pyo, Kyoung-Ho; Hwang, Young-Sang; Chun, Hyang Sook; Park, Ki Hwan; Ko, Seong-Hee; Chai, Jong-Yil; Shin, Eun-Hee

    2013-11-15

    Artificial digestive solution based on pepsin is essential for collecting metacercariae from fish. To promote the enzymatic reactivity of pepsin, the pH of the solution has to be adjusted to pH 1.0-2.0. Hydrochloride (HCl) is usually used for this purpose, but the use of HCl raises safety concerns. The aim of this work was to address the usefulness of citric acid as an alternative for HCl for the acidification of pepsin solution, and to examine its potential to damage metacercariae during in vitro digestion as compared with HCl. Changes in pH after adding 1-9% of citric acid (m/v) to pepsin solution were compared to a 1% HCl (v/v) addition. Digestion of fish muscle was evaluated by measuring released protein concentrations by spectrophotometry. In addition, survival rates of metacercariae in pepsin solution were determined at different citric acid concentrations and were compared that of with 1% HCl. The present study shows that addition of citric acid reduced the pH of pepsin solutions to the required level. Addition of more than 5% of citric acid resulted in the effective digestion of fish muscle over 3h in vitro, and 5% citric acid was less lethal to metacercariae than 1% HCl in pepsin solution. Pepsin solution containing 5% citric acid had digestive capacity superior to pepsin solution containing 1% HCl after 3h incubation with released protein concentrations of 12.0 ng/ml for 5% citric acid and 9.6 ng/ml for 1% HCl. Accordingly, the present study suggests that the addition of 5% citric acid to pepsin solution is a good alternative to 1% HCl in infection studies because citric acid is a stable at room temperature and has a good safety profile. In addition, we suggest that the use of citric acid enables the preparation of commercial digestive solutions for the detection of microorganisms in fish and other vertebrate muscle tissue.

  13. HPLC法测定注射用亚锡喷替酸中喷替酸的含量%HPLC Determination of Pentetate Acid in Pentetate Acid and Stannous Chloride for Injection

    Institute of Scientific and Technical Information of China (English)

    汪洋; 吴二明; 王刚; 刘佳琳; 陈志明

    2014-01-01

    Objective:To establish a reversed-phase HPLC method for determination of pentetate acid in pentetate acid and stan-nous chloride for injection, tetrabutylammonium hydrogen sulfate was used as ion pair reagent.Methods: A SunFireTM C18 ODS column (4.6 mm ×150 mm,5 μm) was adopted with 0.05 mol· L-1 sodium acetate buffer solution-methanol (95∶5) as the mobile phase at a flow rate of 1.0 mL· min-1 ,and detected at 360 nm.Results: The curve was linear in the range of 1.6 -8μg(r=0.9998),the average recovery was 99.1% and RSD was 1.1%.Contents of pentetate acid in different batches of sample were 100.1%-102.9%.Conclusion: This method is simple, accurate and reproducible for the quantitative analysis of pen-tetate acid in pentetate acid and stannous chloride for injection and can be used for the quality control of the active pharmaceutical ingredient.%目的:以四丁基硫酸氢铵为离子对试剂,采用离子对反相高效液相色谱法测定注射用亚锡喷替酸中喷替酸的含量。方法:采用SunFireTM C18色谱柱(4.6 mm ×150 mm,5μm),流动相为0.05 mol· L-1醋酸钠缓冲液(pH4.5)-甲醇(95∶5),内含5 mmol· L-1四丁基硫酸氢铵,流量1.0 mL· min-1,检测波长360 nm。结果:喷替酸在1.6~8μg范围内线性良好( r=0.9998);平均加样回收率为99.1%, RSD为1.1%( n=9);不同批号的注射用亚锡喷替酸中喷替酸的含量为100.1%~102.9%。结论:本方法简便、准确,重复性好,适用于注射用亚锡喷替酸的质量控制。

  14. Uptake of hypobromous acid (HOBr by aqueous sulfuric acid solutions: low-temperature solubility and reaction

    Directory of Open Access Journals (Sweden)

    L. T. Iraci

    2005-03-01

    Full Text Available Hypobromous acid (HOBr is a key species linking inorganic bromine to the chlorine and odd hydrogen chemical families. We have measured the solubility of HOBr in 45–70 wt% sulfuric acid solutions representative of upper tropospheric and lower stratospheric aerosol composition. Over the temperature range 201–252 K, HOBr is quite soluble in sulfuric acid, with an effective Henry's law coefficient, H*=104-107 mol L-1 atm-1. H* is inversely dependent on temperature, with ΔH=-45.0±5.4 kJ mol-1 and ΔS=-101±24 J mol-1 K-1 for 55–70 wt% H2SO4 solutions. Our study includes temperatures which overlap both previous measurements of HOBr solubility. For uptake into 55–70 wt% H2SO4, the solubility is described by log H*=(2349±280/T–(5.27±1.24. At temperatures colder than ~213 K, the solubility of HOBr in 45 wt% H2SO4 is at least a factor of five larger than in 70 wt% H2SO4, with log H*=(3665±270/T–(10.63±1.23. The solubility of HOBr is comparable to that of HBr, indicating that upper tropospheric and lower stratospheric aerosols should contain equilibrium concentrations of HOBr which equal or exceed those of HBr. Upon uptake of HOBr into aqueous sulfuric acid in the presence of other brominated gases, particularly for 70 wt% H2SO4 solution, our measurements demonstrate chemical reaction of HOBr followed by evolution of gaseous products including Br2O and Br2.

  15. Adsorption of thorium by alkylammonium salts of iso and heteropolyacids of transition metals from aqueous solutions. III. Investigation of the coprecipitation of thorium with alkyltrimethylammonium phosphomolybdates as a function of solution acidity

    International Nuclear Information System (INIS)

    Results are presented of investigations on the isolation of thorium from aqueous solution by coprecipitation with hydrophobic compounds resulting from the direct interaction of 12-phosphomolybdic heteropolyacid (HPA) with alkyltrimethylammonium chloride, as a function of the acidity of the aqueous phase. It was established that the degree of extraction of thorium grew with an increase in pH value and on going to more dilute HPA solution. At a solution concentration of HPA equal to 3.1 x 10-3 mole/liter thorium in hydrochloric acid medium begins to be removed at a higher acidity of the aqueous phase in comparison with sulfuric acid. The interaction of thorium with hydrophobic precipitates occurs as a result of complex-forming processes with HPA or with products of its decomposition. Data are presented of IR spectroscopic investigations of the composition of the hydrophobic precipitates obtained under different conditions. It was shown that the differences in the character of thorium distribution between the precipitate and solution were determined by the change in composition of the solid phase

  16. Genesis and solution chemistry of acid sulfate soils in Thailand

    NARCIS (Netherlands)

    Breemen, van N.

    1976-01-01

    To study short-term and long-term chemical processes in periodically flooded acid sulfate soils in the Bangkok Plain and in various smaller coastal plains along the Gulf of Thailand, 16 acid sulfate soils and one non-acid marine soil were examined for distribution of iron-sulfur compounds, elemental

  17. Separation of rare earths from solutions of phosphoric acid

    International Nuclear Information System (INIS)

    Rare earths are separated from 6M phosphoric acid by adsorption onto cation resin BIORAD AG50W-X8. The phosphoric acid is then washed from the column, and the rare earths are eluted with 4M hydrochloric acid

  18. Evaluation of Deoxyribonucleic Acid Toxicity Induced by the Radiopharmaceutical 99mTechnetium-Methylenediphosphonic Acid and by Stannous Chloride in Wistar Rats

    Directory of Open Access Journals (Sweden)

    Adriano Caldeira-de-Araujo

    2012-11-01

    Full Text Available Radiopharmaceuticals are employed in patient diagnostics and disease treatments. Concerning the diagnosis aspect, technetium-99m (99mTc is utilized to label radiopharmaceuticals for single photon computed emission tomography (SPECT due to its physical and chemical characteristics. 99mTc fixation on pharmaceuticals depends on a reducing agent, stannous chloride (SnCl2 being the most widely-utilized. The genotoxic, clastogenic and anegenic properties of the 99mTc-MDP(methylene diphosphonate used for bone SPECT and SnCl2 were evaluated in Wistar rat blood cells using the Comet assay and micronucleus test. The experimental approach was to endovenously administer NaCl 0.9% (negative control, cyclophosphamide 50 mg/kg b.w. (positive control, SnCl2 500 μg/mL or 99mTc-MDP to animals and blood samples taken immediately before the injection, 3, and 24 h after (in the Comet assay and 36 h after, for micronucleus test. The data showed that both SnCl2 and 99mTc-MDP-induced deoxyribonucleic acid (DNA strand breaks in rat total blood cells, suggesting genotoxic potential. The 99mTc-MDP was not able to induce a significant DNA strand breaks increase in in vivo assays. Taken together, the data presented here points to the formation of a complex between SnCl2 in the radiopharmaceutical 99mTc-MDP, responsible for the decrease in cell damage, compared to both isolated chemical agents. These findings are important for the practice of nuclear medicine.

  19. Inhibition of copper corrosion in sodium chloride solution by the self-assembled monolayer of sodium diethyldithiocarbamate

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Q.Q., E-mail: liaoqq1971@yahoo.com.c [Key Lab of Shanghai Colleges and Universities for Electric Power Corrosion Control and Applied Electrochemistry, Shanghai Engineering Research Center of Energy - Saving in Heat Exchange Systems, Shanghai University of Electric Power, Shanghai 200090 (China); Yue, Z.W.; Yang, D. [Key Lab of Shanghai Colleges and Universities for Electric Power Corrosion Control and Applied Electrochemistry, Shanghai Engineering Research Center of Energy - Saving in Heat Exchange Systems, Shanghai University of Electric Power, Shanghai 200090 (China); Wang, Z.H. [Department of Chemistry, Tongji University, Shanghai 200092 (China); Li, Z.H. [Department of Chemistry, Fudan University, Shanghai 200433 (China); Ge, H.H. [Key Lab of Shanghai Colleges and Universities for Electric Power Corrosion Control and Applied Electrochemistry, Shanghai Engineering Research Center of Energy - Saving in Heat Exchange Systems, Shanghai University of Electric Power, Shanghai 200090 (China); Li, Y.J. [Department of Chemistry, Tongji University, Shanghai 200092 (China)

    2011-05-15

    Research highlights: DDTC is of low toxicity. DDTC SAM had good corrosion inhibition effects on copper in 3% NaCl solution. DDTC SAM was chemisorbed on copper surface by its S atoms. - Abstract: Sodium diethyldithiocarbamate (DDTC) self-assembled monolayer (SAM) on copper surface has been investigated by SERS and EDS and the results show that DDTC SAM is chemisorbed on copper surface by its S atoms with tilted orientation. Corrosion inhibition ability of DDTC SAM was measured in 3% NaCl solution using electrochemical methods. The impedance results indicate that the maximum inhibition efficiency of DDTC SAM can reach 99%. Quantum chemical calculations show that DDTC has relatively small {Delta}E between HOMO and LUMO and large negative charge in its two sulfur atoms, which facilitates the formation of a DDTC SAM on copper surface.

  20. Study of caffeine as corrosion inhibitors of carbon steel in chloride solution containing hydrogen sulfide using electrochemical impedance spectroscopy (EIS)

    Science.gov (United States)

    Solehudin, Agus; Berman, Ega Taqwali; Nurdin, Isdiriayani

    2015-09-01

    The corrosion behaviour of steel surface in the absence and presence of caffeine in 3.5% NaCl solution containing dissolved H2S gas is studied using electrochemical impedance spectroscopy (EIS). The experimental results of carbon steel corrosion in 3.5% NaCl solution containing 500 mg/l H2S at different caffeine concentrations showed that corrosion rate of carbon steel decreases with increasing of caffeine concentrations from 0 to 0,1 mmol/l. Whereas, the corrosion rate increase with increasing of caffeine concentrations from 1 to 10 mmol/l. It is clear that no inhibition efficiency increases with increasing inhibitor concentration. The optimum value of inhibition efficiency was 90% at a caffeine concentration of 0.1 mmol/l. This suggests that caffeine's performance as a corrosion inhibitor is more effective at a concentration of 0.1 mmol/l.

  1. The analysis of crystallization of sodium chloride from the solution in vacuum crystallizer with the recirculation of the suspension

    OpenAIRE

    Jotanović Milovan B.; Suljkanović Midhat S.

    2009-01-01

    Crystallization from a solution most often is the final stage of many technological processes, and has a major role in bulk chemical industry. Basic requirements which stand before the process of crystallization are as follows: providing a minimum energy use-up together with a maximum specific capacity of the crystallizer, as well as with obtaining a product with the necessary degree of purity. These demands are successfully fulfilled by vacuum crystallizers with recirculation of suspension, ...

  2. Solvent Extraction of Tellurium from Chloride Solutions Using Tri-n-butyl Phosphate: Conditions and Thermodynamic Data

    OpenAIRE

    Dongchan Li; Yafei Guo; Tianlong Deng; Yu-Wei Chen; Nelson Belzile

    2014-01-01

    The extractive separation of tellurium (IV) from hydrochloric acid media with tri-n-butyl phosphate (TBP) in kerosene was investigated. The dependence on the extraction of tellurium species, concentrations of tellurium and TBP, extraction time and stage, organic/aqueous ratio, and interferences from coexist metallic ions were examined and are discussed. Besides, the stripping agent and stripping time were also studied. It was found that the extraction reaction corresponds to the neutral compl...

  3. 49 CFR 173.229 - Chloric acid solution or chlorine dioxide hydrate, frozen.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Chloric acid solution or chlorine dioxide hydrate, frozen. 173.229 Section 173.229 Transportation Other Regulations Relating to Transportation PIPELINE AND... Than Class 1 and Class 7 § 173.229 Chloric acid solution or chlorine dioxide hydrate, frozen. When...

  4. Effects of pH and chloride concentration on pitting corrosion of AA6061 aluminum alloy

    Energy Technology Data Exchange (ETDEWEB)

    Zaid, B. [Division de Technologie du Combustible, Departement de Metallurgie, Centre de Recherche Nucleaire de Draria, BP. 43 Seballa, Draria (Algeria)], E-mail: zaidbachir@yahoo.com; Saidi, D. [Division de Technologie du Combustible, Departement de Metallurgie, Centre de Recherche Nucleaire de Draria, BP. 43 Seballa, Draria (Algeria); Benzaid, A. [Divisionde Physique et Application Nucleaires, Departement Application Nucleaires, Centre de Recherche Nucleaire de Draria, BP. 43 Seballa, Draria (Algeria); Hadji, S. [Division de Technologie du Combustible, Departement du combustible, Centre de Recherche Nucleaire de Draria, BP. 43 Seballa, Draria (Algeria)

    2008-07-15

    Effects of pH solution and chloride (Cl{sup -}) ion concentration on the corrosion behaviour of alloy AA6061 immersed in aqueous solutions of NaCl have been investigated using measurements of weight loss, potentiodynamic polarisation, linear polarisation, cyclic polarisation experiment combined with open circuit potential transient technique and optical or scanning electron microscopy. The corrosion behaviour of the AA6061 aluminum alloy was found to be dependant on the pH and chloride concentration [NaCl] of solution. In acidic or slightly neutral solutions, general and pitting corrosion occurred simultaneously. In contrast, exposure to alkaline solutions results in general corrosion. Experience revealed that the alloy AA6061 was susceptible to pitting corrosion in all chloride solution of concentration ranging between 0.003 wt% and 5.5 wt% NaCl and an increase in the chloride concentration slightly shifted both the pitting E{sub pit} and corrosion E{sub cor} potentials to more active values. In function of the conditions of treatment, the sheets of the alloy AA6061 undergo two types of localised corrosion process, leading to the formation of hemispherical and crystallographic pits. Polarisation resistance measurements in acidic (pH = 2) and alkaline chloride solutions (pH = 12) which are in good agreement with those of weight loss, show that the corrosion kinetic is minimised in slightly neutral solutions (pH = 6)

  5. Aminopyrimidine derivatives as inhibitors for corrosion of 1018 carbon steel in nitric acid solution

    Energy Technology Data Exchange (ETDEWEB)

    Abdallah, M. [Chemistry Department, Faculty of Science, Benha University, Benha (Egypt)]. E-mail: metwally552@hotmail.com; Helal, E.A. [Corrosion Department, Badr El-Din Petroleum company (Egypt); Fouda, A.S. [Chemistry Department, Faculty of Science, Mansoura University, Mansoura 35516 (Egypt)]. E-mail: asfouda@yahoo.com

    2006-07-15

    The effect of some aminopyrimidine derivatives on the corrosion of 1018 carbon steel in 0.05 M HNO{sub 3} solution was studied using weight loss and polarization techniques. The percentage inhibition efficiency was found to increase with increasing concentration of inhibitor and with decreasing temperature. The addition of KI to aminopyrimidine derivatives enhanced the inhibition efficiency due to synergistic effect. The inhibitors are adsorbed on the steel surface according to Temkin isotherm. Some thermodynamic functions were computed and discussed. It was found that the aminopyrimidine derivatives provide a good protection to steel against pitting corrosion in chloride containing solutions.

  6. Mathematical modeling of cadmium(II) solvent extraction from neutral and acidic chloride media using Cyanex 923 extractant as a metal carrier.

    Science.gov (United States)

    Leopold, A A; Coll, M T; Fortuny, A; Rathore, N S; Sastre, A M

    2010-10-15

    This paper describes experimental work and the mathematical modeling of solvent extraction of cadmium(II) from neutral and acidic aqueous chloride media with a Cyanex 923 extractant in Exxol D-100. Solvent extraction experiments were carried out to analyze the influence of variations in the composition of the aqueous and organic phases on the efficiency of cadmium(II) extraction. In neutral and acidic chloride conditions, the extraction of cadmium(II) by the organophosphorous extractant Cyanex 923 (L) is based on the solvation mechanism of neutral H(n)CdCl((2+n)) species and the formation of H(n)CdCl((2+n))L(q) complexes in the organic phase, where n=0, 1, 2 and q=1, 2. The mathematical model of cadmium(II) extraction was derived from the mass balances and chemical equilibria involved in the separation system. The model was computed with the Matlab software. The equilibrium parameters for metal extraction, i.e. the stability constants of the aqueous Cd-Cl complexes, the formation constants of the acidic Cd-Cl species and the metal equilibrium extraction constants, were proposed. The optimized constants were appropriate, as there was good agreement when the model was fitted to the experimental data for each of the experiments.

  7. Mathematical modeling of cadmium(II) solvent extraction from neutral and acidic chloride media using Cyanex 923 extractant as a metal carrier

    Energy Technology Data Exchange (ETDEWEB)

    Leopold, A.A., E-mail: agnieszka.leopold@upc.edu [Department of Chemical Engineering, Universitat Politecnica de Catalunya, EPSEVG, Av. Victor Balaguer s/n, 08800 Vilanova i la Geltru (Spain); Coll, M.T.; Fortuny, A.; Rathore, N.S. [Department of Chemical Engineering, Universitat Politecnica de Catalunya, EPSEVG, Av. Victor Balaguer s/n, 08800 Vilanova i la Geltru (Spain); Sastre, A.M. [Department of Chemical Engineering, Universitat Politecnica de Catalunya, ETSEIB, Av. Diagonal 647, 08028 Barcelona (Spain)

    2010-10-15

    This paper describes experimental work and the mathematical modeling of solvent extraction of cadmium(II) from neutral and acidic aqueous chloride media with a Cyanex 923 extractant in Exxol D-100. Solvent extraction experiments were carried out to analyze the influence of variations in the composition of the aqueous and organic phases on the efficiency of cadmium(II) extraction. In neutral and acidic chloride conditions, the extraction of cadmium(II) by the organophosphorous extractant Cyanex 923 (L) is based on the solvation mechanism of neutral H{sub n}CdCl{sub (2+n)} species and the formation of H{sub n}CdCl{sub (2+n)}L{sub q} complexes in the organic phase, where n = 0, 1, 2 and q = 1, 2. The mathematical model of cadmium(II) extraction was derived from the mass balances and chemical equilibria involved in the separation system. The model was computed with the Matlab software. The equilibrium parameters for metal extraction, i.e. the stability constants of the aqueous Cd-Cl complexes, the formation constants of the acidic Cd-Cl species and the metal equilibrium extraction constants, were proposed. The optimized constants were appropriate, as there was good agreement when the model was fitted to the experimental data for each of the experiments.

  8. Chemical evaluation of soil-solution in acid forest soils

    Science.gov (United States)

    Lawrence, G.B.; David, M.B.

    1996-01-01

    Soil-solution chemistry is commonly studied in forests through the use of soil lysimeters.This approach is impractical for regional survey studies, however, because lysimeter installation and operation is expensive and time consuming. To address these problems, a new technique was developed to compare soil-solution chemistry among red spruce stands in New York, Vermont, New Hampshire, Maine. Soil solutions were expelled by positive air pressure from soil that had been placed in a sealed cylinder. Before the air pressure was applied, a solution chemically similar to throughfall was added to the soil to bring it to approximate field capacity. After the solution sample was expelled, the soil was removed from the cylinder and chemically analyzed. The method was tested with homogenized Oa and Bs horizon soils collected from a red spruce stand in the Adirondack Mountains of New York, a red spruce stand in east-central Vermont, and a mixed hardwood stand in the Catskill Mountains of New York. Reproducibility, effects of varying the reaction time between adding throughfall and expelling soil solution (5-65 minutes) and effects of varying the chemical composition of added throughfall, were evaluated. In general, results showed that (i) the method was reproducible (coefficients of variation were generally reaction-time did not affect expelled solution concentrations, and (iii) adding and expelling solution did not cause detectable changes in soil exchange chemistry. Concentrations of expelled solutions varied with the concentrations of added throughfall; the lower the CEC, the more sensitive expelled solution concentrations were to the chemical concentrations of added throughfall. Addition of a tracer (NaBr) showed that the expelled solution was a mixture of added solution and solution that preexisted in the soil. Comparisons of expelled solution concentrations with concentrations of soil solutions collected by zero-tension and tension lysimetry indicated that expelled

  9. The inhibition of low carbon steel corrosion in hydrochloric acid solutions by succinic acid

    International Nuclear Information System (INIS)

    The effect of succinic acid (SA) on the corrosion inhibition of a low carbon steel (LCS) electrode has been investigated in aerated non-stirred 1.0 M HCl solutions in the pH range (2-8) at 25 oC. Weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques were applied to study the metal corrosion behaviour in the absence and presence of different concentrations of SA under the influence of various experimental conditions. Measurements of open circuit potential (OCP) as a function of time till steady-state potentials (E st) were also established. Surface analysis using energy dispersive X-ray (EDX) and scanning electron microscope (SEM) allowed us to clarify the mechanistic aspects and evaluate the relative inhibition efficiency. Results obtained showed that SA is a good 'green' inhibitor for LCS in HCl solutions. The polarization curves showed that SA behaves mainly as an anodic-type inhibitor. EDX and SEM observations of the electrode surface confirmed existence of a protective adsorbed film of the inhibitor on the electrode surface. The inhibition efficiency increases with increase in SA concentration, pH of solution and time of immersion. Maximum inhibition efficiency (∼97.5%) is obtained at SA concentrations >0.01 M at pH 8. The effect of SA concentration and pH on the potential of zero charge (PZC) of the LCS electrode in 1.0 M HCl solutions has been studied and the mechanism of adsorption is discussed. Results obtained from weight loss, polarization and impedance measurements are in good agreements

  10. Recovery of salicylic acid from aqueous solution by solvent extraction and supported liquid membrane using TOMAC as carrier

    International Nuclear Information System (INIS)

    Conventional sewage treatment plants do not fully degrade residues of pharmaceuticals, so that they are introduced into the aquatic environment. On this basis, the demand for the development of efficient systems for removing these compounds from water has assumed a great research interest. Membrane operations are increasingly employed in many industrial sectors as important alternative technologies to the classical processes of separation. Among membrane-based separation processes, the use of supported liquid membranes (SLMs) has received growing attention during recent years. In our work we had tried to recover a pharmaceutical product, salicylic acid (S.A), from an aqueous solution by solvent extraction and supported liquid membrane using an ionic liquid: the tri octylmethylammonium chloride (TOMAC) as carrier. Ionic liquids has been revealed as interesting clean alternatives to classical solvents and their use as a liquid phase results in the stabilization of the SLMs duo to their negligible vapour pressure, the possibility of minimising their solubility in the surrounding phases by adequate selection of the cation and anion, and the greater capillary force associated with their high viscosity. For this reason we had studied the influence of different parameters which could affect the efficiency of the transport: pH of the feed phase, the nature of the strippant, the concentration of the strippant, the nature of the support and the initial concentration of the salicylic acid in the feed phase. We had noticed that the pH of the feed solution had no effect of the percentage extraction and after 24 hours we can extract completely our solute. TOMAC seemed to be a good extractant but we found difficult to strip salicylic acid from the TOMAC phase and this could be related to the formation of water micro environments in the ionic liquid membrane.

  11. Adsorption of β-naphthalenesulfonic acid/sulfuric acid from their solution by weakly basic resin: equilibrium

    Institute of Scientific and Technical Information of China (English)

    LI Chang-hai; SHI Peng-fei

    2005-01-01

    Experiments for single and bisolute competitive adsorption were carried out to investigate the adsorption behavior of β-naphthalenesulfonic acid(NSA) and sulfuric acid (H2 SO4 ) from their solution at 25 ℃ onto weakly basic resin D301R. Adsorption affinity of sulfuric acid on D301R was found to be much higher than that of NSA. The data of single-solute adsorption were fitted to the Langmuir model and the Freundlich adsorption model. The ideal adsorbed solution theory(IAST) coupled with the single-solute adsorption models were used to predict the bisolute competitive adsorption equilibria. The IAST coupled with the Langmuir and the Freundlich model for sulfuric acid and NSA, respectively, yields the favorable representation of the bisolute competitive adsorption behavior.

  12. 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.

  13. Corrosion Properties in Sodium Chloride Solutions of Al–TiC Composites in situ Synthesized by HFIHF

    Directory of Open Access Journals (Sweden)

    El-Sayed M. Sherif

    2015-10-01

    Full Text Available Al–TiC nanocomposite materials have been prepared by a new in situ synthesizing technique. A mixture of aluminum, titanium, and graphite has been prepared using ball milling technique and then melted in a high frequency induction heat furnace (HFIHF at different sintering temperatures, namely 900, 1100, and 1300 °C. The effect of sintering temperature on the corrosion of the Al–TiC composite in 3.5% NaCl solutions was investigated using cyclic potentiodynamic polarization, chronoamperometric current-time, open-circuit potential, and electrochemical impedance spectroscopy measurements. The surface of the composites after their corrosion in the test solution was investigated using scanning electron microscopy and energy dispersive X-ray analyses. It has been found that all manufactured composites suffer uniform corrosion. All corrosion test techniques were consistent with each other and confirmed clearly that the corrosion resistance of Al composites increased according to their sintering temperature in the following order 900 > 1100 > 1300 °C.

  14. Radiation-thermal decomposition of nitric and acetic acids in the aqueous nitrate solution

    International Nuclear Information System (INIS)

    Kinetics of radiation, thermal and radiation-thermal decompositions of nitric and acetic acid mixture was investigated in aqueous sodium nitrate solution in homogeneous conditions as well as by interaction of solid phase as sand rock. Temperature dependences of rate of radiation, thermal and radiation-thermal decompositions of the acids were calculated using experimental data. Resulting solutions make possible the calculation of acid decomposition dynamics accounting conditions of underground radioactive waste disposals

  15. CO2 Capture from Flue Gas using Amino Acid Salt Solutions

    DEFF Research Database (Denmark)

    Lerche, Benedicte Mai; Stenby, Erling Halfdan; Thomsen, Kaj

    2009-01-01

    difficult. Amino acid salt solutions have emerged as an alternative to the alkanolamine solutions. A number of advantages make amino acid salt solutions attractive solvents for CO2 capture from flue gas. In the present study CO2 absorption in aqueous solutions of 0.5 M potassium glycinate and 0.5 M...... monoethanolamine (MEA) were performed, using a stirred cell reactor experimental setup. The absorption of gas containing 10 mol % CO2 and 90 mol % N2 was followed by measuring the percentage of CO2 in the outlet gas. Also the temperature and pH in the solutions were measured during the absorption. The results...

  16. Iodine absorption in mixed solution of sodium hydroxide-boric acid

    International Nuclear Information System (INIS)

    In the absorption solution used for the removal of radioactive iodine in the exhaust gas from nuclear facilities by washing with water, boron compounds with large neutron capture cross section are mixed in many cases as nuclear reaction inhibitor. Generally sodium hydroxide aqueous solution in which boric acid is dissolved is employed. Therefore in practical point of view, absorption of iodine in the mixed solution of sodium hydroxide - boric acid is important, and the partition equilibrium of iodine in sodium hydroxide - boric acid, vapor - liquid overall dissolution equilibrium coefficient between the mixed solution and decarboxilated air, and iodine absorption rate in the mixed solution were experimented and discussed. Boric acid partly becomes ions by hydrolysis in the mixed solution of sodium hydroxide - boric acid and acts as a pH control agent. It only affects the partition of iodine in liquid phase through its dissociation and electric charge equilibrium. Overall absorption rate of iodine decreases by adding the boric acid. Alkaline water of 9.5 to 10 pH containing boric acid of 1 to 3 g-boron/kg-water is very often used as the absorption solution for the removal of radioactive iodine by washing with alka- line water. This condition of boric acid concentration is higher than the condition in this investigation, and hence the detailed examination by the experiments over a wide range of concentration will be necessary. (Wakatsuki, Y

  17. Oxalic acid complexes: Promising draw solutes for forward osmosis (FO) in protein enrichment

    KAUST Repository

    Ge, Qingchun

    2015-01-01

    Highly soluble oxalic acid complexes (OACs) were synthesized through a one-pot reaction. The OACs exhibit excellent performance as draw solutes in FO processes with high water fluxes and negligible reverse solute fluxes. Efficient protein enrichment was achieved. The diluted OACs can be recycled via nanofiltration and are promising as draw solutes.

  18. HYDRAZOIC ACID CONTROLS AND RISKS WHEN PROCESSING NEPTUNIUM SOLUTIONS IN HB-LINE PHASE II

    International Nuclear Information System (INIS)

    Hydrazine mononitrate will be used in processing neptunium in Phase II of HB-Line to scavenge nitrous acid (a byproduct of nitric acid) in the column feed adjustment tank (JT-71 or JT-72) and also in the precipitation feed adjustment tanks (NT-41/42). Nitrous acid can interfere with valence adjustment chemicals (e.g., ferrous sulfamate and ascorbic acid) and thus interfere with controls that give proper neptunium valence. Hydrazine reacts with nitrous acid to form hydrazoic acid, and the hydrazoic acid also reacts with nitrous acid. The concentration of hydrazoic acid can be controlled below the autocatalytic decomposition limit in both liquid and vapor by controlling the maximum concentration of hydrazine mononitrate in the acid solution. The concentration of nitrous acid available for reaction with hydrazine also limits the amount of hydrazoic acid in solution. The hydrazine concentration will be controlled at or below 0.15M in the neptunium solutions to maintain the hydrazoic acid concentration below autocatalytic decomposition limits. Equipment failures and/or human errors that could cause hydrazine to be present above this limit are evaluated. Satisfying the assumptions stated in this report result in a frequency of Beyond Extremely Unlikely (BEU) for a hydrazoic acid autocatalytic decomposition reaction in either the liquid or vapor phase of the process vessels

  19. On the Absorption of Isobutene and trans-2-Butene in Sulfuric Acid Solutions

    NARCIS (Netherlands)

    Brilman, D.W.F.; Swaaij, W.P.M. van; Versteeg, G.F.

    1997-01-01

    In reactions in which alkenes react in the presence of homogeneous Brønstedt acid catalysts, the protonation step is rate determining. Existing reaction rate correlations for protonation of butenes in sulfuric acid solutions are not consistent and limited to sulfuric acid concentrations below 80 wt

  20. The uptake and transpiration of water and the accumulation of lead by plants growing on lead chloride solutions

    Directory of Open Access Journals (Sweden)

    Marek Burzyński

    2014-02-01

    Full Text Available The placement of approximately two week-old bean, cucumber and wheat plants in PbCl2 solutions caused significant decreases in transpiration and uptake of water. The amount of transpiration and water uptake depended on the PbCl2 concentration and length of treatment. Cucumber plants were the most sensitive to lead and accumu-lated the. greatest amounts of it. Beans were the least sensitive, although they accumulated more lead than wheat. The lead taken up by cucumbers and beans accumulated mainly in the roots while the distribution of lead in wheat was rather uniform in the roots and above-ground parts. The removal of roots from bean plants caused high accumulation of lead in the lower stem parts.

  1. Solution properties and taste behavior of lactose monohydrate in aqueous ascorbic acid solutions at different temperatures: Volumetric and rheological approach.

    Science.gov (United States)

    Sarkar, Abhijit; Sinha, Biswajit

    2016-11-15

    The densities and viscosities of lactose monohydrate in aqueous ascorbic acid solutions with several molal concentrations m=(0.00-0.08)molkg(-1) of ascorbic acid were determined at T=(298.15-318.15)K and pressure p=101kPa. Using experimental data apparent molar volume (ϕV), standard partial molar volume (ϕV(0)), the slope (SV(∗)), apparent specific volumes (ϕVsp), standard isobaric partial molar expansibility (ϕE(0)) and its temperature dependence [Formula: see text] the viscosity B-coefficient and solvation number (Sn) were determined. Viscosity B-coefficients were further employed to obtain the free energies of activation of viscous flow per mole of the solvents (Δμ1(0≠)) and of the solute (Δμ2(0≠)). Effects of molality, solute structure and temperature and taste behavior were analyzed in terms of solute-solute and solute-solvent interactions; results revealed that the solutions are characterized predominantly by solute-solvent interactions and lactose monohydrate behaves as a long-range structure maker. PMID:27283672

  2. Sucrose and KF quenching system for solution phase parallel synthesis.

    Science.gov (United States)

    Chavan, Sunil; Watpade, Rahul; Toche, Raghunath

    2016-01-01

    The KF, sucrose (table sugar) exploited as quenching system in solution phase parallel synthesis. Excess of electrophiles were covalently trapped with hydroxyl functionality of sucrose and due to polar nature of sucrose derivative was solubilize in water. Potassium fluoride used to convert various excess electrophilic reagents such as acid chlorides, sulfonyl chlorides, isocyanates to corresponding fluorides, which are less susceptible for hydrolysis and subsequently sucrose traps these fluorides and dissolves them in water thus removing them from reaction mixture. Various excess electrophilic reagents such as acid chlorides, sulfonyl chlorides, and isocyanates were quenched successfully to give pure products in excellent yields. PMID:27462506

  3. Corrosion and Inhibition Effects of Mild Steel in Hydrochloric Acid Solutions Containing Organophosphonic Acid

    Directory of Open Access Journals (Sweden)

    Manish Gupta

    2013-01-01

    Full Text Available A study has been made on the mechanism of corrosion of mild steel and the effect of nitrilo trimethylene phosphonic (NTMP acid as a corrosion inhibitor in acidic medium, that is, 10% HC1 using the weight loss method and electrochemical techniques, that is, potentiodynamic and galvanostatic polarization measurements. Although corrosion is a long-time process, but it takes place at a faster rate in the beginning which goes on decreasing with due course of time. The above-mentioned methods of corrosion rate determination furnish an average value for a long-time interval. Looking at the versatility and minimum detection limit of the voltammetric method, the authors have developed a new voltammetric method for the determination of corrosion rate at short-time intervals. The results of corrosion of mild steel in 10% HC1 solution with and without NTMP inhibitor at short-time intervals have been reported. The corrosion inhibition efficiency of NTMP is 93% after 24 h.

  4. The kinetics of the solidification of highly supersaturated solutions of palmitic acid in oleic acid: a comparison between two models

    OpenAIRE

    RAMIRO RICO-MARTINEZ; JOSE ALBERTO GALLEGOS-INFANTE

    1999-01-01

    The crystallization of fatty acids is very important in industrial applications and biological systems. A comparison between theoretical models and experimental data helps in clarifying mechanistic aspects of these systems. In this contribution, we compare the performance of two models in fitting data from the crystallization of supersaturated solutions of palmitic acid in oleic acid. One of the models was developed by Avrami and the other is based on considering diffusion as limiting (the D-...

  5. 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.

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

    International Nuclear Information System (INIS)

    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 (Na2S2O5) on pitting corrosion of 6061 aluminum alloy, in 5 × 10−2 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 Na2S2O5 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

  7. Amino acid salt solutions for carbon dioxide capture

    OpenAIRE

    Majchrowicz, Magdalena Elzbieta

    2014-01-01

    Reactive absorption is a common process in the chemical industry and is used, among others, in the treatment of CO2 containing industrial gas streams. The current work was a part of a project with the aim to assess new reactive solvents based on amino acid salts for CO2 removal from industrial gas streams. Initially, a group of promising amino acid salts (taurine, sarcosine, L-proline, -alanine, 6-aminohexanoic acid and DL-methionine) was screened for their CO2 absorption kinetics, pKa value...

  8. Amino acid salt solutions as solvents in CO2 capture from flue gas

    DEFF Research Database (Denmark)

    Lerche, Benedicte Mai; Thomsen, Kaj; Stenby, Erling Halfdan

    solutions is their ability to form solid precipitates upon the absorption of CO2. The occurrence of crystallization offers the possibility of increasing the CO2 loading capacity of the solvent. However, precipitation can also have negative effect on the CO2 capture process. The chemical nature of the solid...... loading capacity of aqueous solutions of the potassium salts of selected amino-acids (glycine, taurine, lysine proline, and glutamic acid) were examined, and the relation between the initial amino acid salt concentration and precipitation ability of each solution were determined. Experiments were...... of glycine, taurine, and lysine, while in the case of proline, and glutamic acid, the precipitate was found to be bicarbonate. These results give an important contribution to further understanding the potential of amino acid salt solutions in CO2 capture from flue gas....

  9. Separation of ions in acidic solution by capillary electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Thornton, M.

    1997-10-08

    Capillary electrophoresis (CE) is an effective method for separating ionic species according to differences in their electrophoretic mobilities. CE separations of amino acids by direct detection are difficult due to their similar electrophoretic mobilities and low absorbances. However, native amino acids can be separated by CE as cations at a low pH by adding an alkanesulfonic acid to the electrolyte carrier which imparts selectivity to the system. Derivatization is unnecessary when direct UV detection is used at 185 nm. Simultaneous speciation of metal cations such as vanadium (IV) and vanadium (V) can easily be performed without complexation prior to analysis. An indirect UV detection scheme for acidic conditions was also developed using guanidine as the background carrier electrolyte (BCE) for the indirect detection of metal cations. Three chapters have been removed for separate processing. This report contains introductory material, references, and general conclusions. 80 refs.

  10. Extraction of uranium from aqueous solution by phosphonic acid-imbedded polyurethane foam

    International Nuclear Information System (INIS)

    Phenylphosphonic acid was imbedded into the matrix of the polyurethane foam during the fabrication process of the polymer. The extraction of uranium by phosphonic acid-imbedded polyurethane foam and blank polyurethane (i.e., foam without phosphonic acid functional groups) was investigated. Phosphonic acid-imbedded foam showed superior extractability of uranium from solutions with pH = 7.0 ± 1.5 over a wide range of temperatures. (author)

  11. 直接挤压孔溶液的氯离子存在状态及碱度研究%Experimental Research on Chloride Form and pH Value of Pore Solution Expressed from Cementitious Materials

    Institute of Scientific and Technical Information of China (English)

    万小梅; 冯玉坤; 赵铁军; 刘超

    2012-01-01

    通过对直接挤压得到的孔溶液进行化学分析,研究了水灰比、龄期、氯盐掺量、碳化暴露等因素对水泥基材料孔溶液的氯离子存在状态以及碱度的影响规律.结果表明:孔溶液中的自由氯离子浓度与水灰比及氯盐掺量有关;随着龄期延长,水化产物对氯离子的结合率上升.在自由氯离子浓度较高的情况下,孔溶液中的氯离子结合率降低;完全碳化条件下孔溶液中的自由氯离子浓度表现出明显增大的趋势,提高幅度为1~11倍;碳化后孔溶液中的氯离子结合率比未碳化试块的孔溶液降低了27%~54%;碳化使得孔溶液的碱度由13.19~13.47降至7.67~8.10.碳化反应降低了水泥浆体的pH值,释放了自由氯离子,极大地改变了混凝土内部的化学环境.%Chloride and alkalinity in pore solution expressed directly from cementitious materials under various influencing factors including mw/mc, age, chloride addition and carbonation exposure were investigated by ion chromatography and pH meter. It is found that the content of free chloride decreases with increase of mw/mc and decrease of chloride addition. The rate of combination of chloride increases with time and decreases with free chloride content in pore solution. The effect of carbonation on the dissolved chloride content in pore solution is great. For cement mortar or paste with different mw/wc(0. 5 and 0. 7) and chloride addition(0, 0. 5% and 1. 0%), complete carbonation can increase the amount of free chloride in pore solution 2 to 12 times. Furthermore, the amount of chemically combined chloride is lowered by 27% to 54%, and the pH value decreases from values in the range between 13. 19 and 13. 47 to values in the range between 7. 67 and 8. 10. It can be concluded that, in addition to lower the pH value of the pore solution, carbonation will release more free chloride from the hydration products into pore solution and the internal chemical

  12. An Experimental Styudy on Gold Solubility in Amino Acid Solution and Its Geological Significance

    Institute of Scientific and Technical Information of China (English)

    张景荣; 陆建军; 等

    1996-01-01

    The experiments on gold solubility in amino acid solution mdicate that gold is very intensively soluble in amino acid(or other organic acids),which is extensively present in geological bodies,and is most soluble in histidine.The temperature and concentration,acidity and type of amino acid in the solution are important factors affecting gold-amino acid complexing. The solubility of gold in amino acid is different under different conditions of temperature, amino acid concentration and pH value of the solution,At 80℃ and pH=6-8,gold is most soluble in amino acid.Gold dispersed in water and rocks could be concentrated and transported by amino acid and then precipitated in favorable loci.Amino acids might have played an important role in metallogenesis as well as in the formation of source beds of gold.Nitrogen,oxygen and sulfur in amino acid might have reacted with gold to form soluble complex ions.

  13. Corrosion Resistance ofAA6063-TypeAl-Mg-SiAlloy by Silicon Carbide in Sodium Chloride Solution for MarineApplication

    Institute of Scientific and Technical Information of China (English)

    Ojo Sunday Isaac Fayomi; Malik Abdulwahab; Ferdinand Asuke

    2015-01-01

    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 (Rp), 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.

  14. 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.

  15. Corrosion evaluation of multi-pass welded nickel–aluminum bronze alloy in 3.5% sodium chloride solution: A restorative application of gas tungsten arc welding process

    International Nuclear Information System (INIS)

    Highlights: • Corrosion of GTA welded nickel–aluminum bronze (C95800) was studied. • Drastic microstructural changes occurred during the welding operations. • The β′ and α phases acts as anode and cathode, correspondingly, in weld region. • A few nanoamperes couple current was measured in ZRA test as galvanic corrosion. • Corrosion resistance of weld parts could not be weakened in marine environments. - Abstract: In this research, the corrosion behavior of a gas tungsten arc welded nickel–aluminum bronze (NAB) alloy is investigated by DC and AC electrochemical techniques in 3.5% sodium chloride solution. Regarding the electrochemical impedance spectroscopy and potentiodynamic results, uniform corrosion resistance of instantly immersed weld and base samples are almost analogous and increased (more in weld region) during the immersion times. Moreover, zero resistant ammeter results demonstrated that the few nanoampere galvanic currents are attributed to microstructural and morphological differences between these two regions. Therefore, the welding procedure could not deteriorate the general corrosion resistance of the restored damaged NAB parts operating in marine environments

  16. Dynamic flow method to study the CO2 loading capacity of amino acid salt solutions

    DEFF Research Database (Denmark)

    Lerche, Benedicte Mai; Stenby, Erling Halfdan; Thomsen, Kaj

    Due to a number of advantages amino acid salt solutions have emerged as alternatives to the alkanolamine solvents for the chemical absorption of CO2 from flue gas. The use of amino acids in CO2 capture is a bio-mimetic process, as it is similar to CO2 binding by proteins in the blood, such as...... hemoglobin. Amino acid salt solutions have the same amine functionality as alkanolamines, and are thus expected to behave similar towards CO2 in flue gas. Despite rising interest, few studies have been performed so far on amino acids as CO2 absorbents....

  17. Quantum chemical prediction of paramagnetic NMR spectra of lanthanide complexes with salicylic acid in water solution

    International Nuclear Information System (INIS)

    17O and 13C paramagnetic NMR (PNMR) shifts have been calculated for Gd complexes with salicylic acid in water solution. These complexes served us as model compounds for simulation of more complicated lanthanide complexes with humic acids. The obtained data demonstrate that paramagnetic NMR spectra are very sensitive to the bonding details of the ligand. Our calculations suggest that formation of Gd(III) complex with salicylic acid in water solution via carboxyl group with uni-dentate coordination is preferable. New experimental studies with the enriched 17O and 13C nuclei of carboxylate groups of the salicylic and humic acids are extremely desirable

  18. Effects of the Biomolecules: Vitamins, Proteins, Amino Acids, and Surfactants: DTAB, MTOAC, TMSOI, Orcinol on Upper Critical Solution Temperatures

    Directory of Open Access Journals (Sweden)

    Vinod Kumar

    2007-09-01

    Full Text Available Upper critical solution temperatures (UCSTS ± 0.05 K and mutual solubilities of phenol + water systems are reported separately with 0.5 millimol kg-1 (mm kg-1 proteins (casein, pepsin, egg-albumin, vitamins (B1-thiamine, B2-riboflavin, B6-pyridoxine, amino acids (glycine, β-alanine, L-leucine and surfactants (dodecyl trimethylammonium bromide- DTAB, trimethylsulphoxonium iodide-TMSOI, methyltrioctylammonium chloride- MTOAC, orcinol. The additives decrease the UCSTs by about 0.50-2 0C with slight enhancement in mutual solubilities but the leucine with two –CH3 (methyl and two - CH2- (methylene groups produce negligible increase in the solubilities. The –CH3 and - CH2- groups develop stronger hydrophobic interactions but the glycine develops stronger hydrophilic interactions due to –N+H3 (amino and –COO- (carboxylic groups and weaker hydrophobic due to single –CH2- group. The leucine increases the solubility by 0.009 mole fractions with a 0.7 0C decrease in USCT as compared to phenol-water. The mole fractions of additives restricted to 0.002 to 0.005 range, the conjugations of casein and vitamins in place of –CH3 groups of amino acids enhance the solubility with lower UCST values.

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

    International Nuclear Information System (INIS)

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

  20. Process for cleaning a nitric acid U/Pu-solution

    International Nuclear Information System (INIS)

    The impure starting solution is passed through a cation exchange column following oxidation of the U/Pu ions present to the hexavalent state. Here the impurities, in particular Americium, are retained and after subsequent elution are handled by known waste treatments or waste utilization (Americium). (orig.)

  1. Neodymium(3) complexing with bischloromethylphosphinic acid in aqueous solution

    International Nuclear Information System (INIS)

    High resolution spectrography is used to study Nd3+ complexing with (ClCH2)2POOH(HL) in aqueous solution. NdL2+ complex (lg Kstab = 0.44±0.04) with the corresponding absorption band with a maximum at λ=4283 A is formed in a system

  2. Thermal decomposition of dilute aqueous formic acid solutions

    DEFF Research Database (Denmark)

    Bjerre, A.B.; Sørensen, E.

    1992-01-01

    or a decarboxylation. In particular the second one is dependent on the reactor vessel used. It is shown to be catalyzed by a mixture of oxides of stainless steel components. The presence of CH3COOH or CH3CHO promotes the decomposition of HCOOH by way of both decarboxylation and oxidation. In any case formic acid...

  3. Systems solutions by lactic acid bacteria: from paradigms to practice

    NARCIS (Netherlands)

    Vos, de W.M.

    2011-01-01

    Lactic acid bacteria are among the powerhouses of the food industry, colonize the surfaces of plants and animals, and contribute to our health and well-being. The genomic characterization of LAB has rocketed and presently over 100 complete or nearly complete genomes are available, many of which serv

  4. Amino acid salt solutions for carbon dioxide capture

    NARCIS (Netherlands)

    Majchrowicz, Magdalena Elzbieta

    2014-01-01

    Reactive absorption is a common process in the chemical industry and is used, among others, in the treatment of CO2 containing industrial gas streams. The current work was a part of a project with the aim to assess new reactive solvents based on amino acid salts for CO2 removal from industrial gas s

  5. Thermodynamics of the complexation of arabinogalactan with salicylic and p-aminobenzoic acids in aqueous solutions

    Science.gov (United States)

    Mudarisova, R. Kh.; Badykova, L. A.

    2016-03-01

    The thermodynamics of complexation of arabinogalactan with salicylic and p-aminobenzoic acids in aqueous solutions is studied by means spectroscopy. The standard thermodynamic characteristics (Δ H°; Δ G°; Δ S°) of complexation are calculated.

  6. Amino acid adsorption on mesoporous materials: influence of types of amino acids, modification of mesoporous materials, and solution conditions.

    Science.gov (United States)

    Gao, Qiang; Xu, Wujun; Xu, Yao; Wu, Dong; Sun, Yuhan; Deng, Feng; Shen, Wanling

    2008-02-21

    In order to disclose the dominant interfacial interaction between amino acids and ordered mesoporous materials, the adsorption behaviors of five amino acids on four mesoporous materials were investigated in aqueous solutions with adjustable amino acid concentration, ion strength, and pH. The selected amino acids were acidic amino acid glutamic acid (Glu), basic amino acid arginine (Arg), and neutral amino acids phenylalanine (Phe), leucine (Leu), and alanine (Ala), and the selected mesoporous materials were SBA-15, Al-SBA-15, CH3(10%)-SBA-15, and CH3(20%)-SBA-15. The adsorption capacities of Glu and Arg were strongly dependent on pH and surface charge of the mesoporous adsorbent. The adsorption of Phe showed pH insensitivity but depended on the surface organic functionalization of mesoporous adsorbent. On the basis of the theoretical analysis about the interaction between amino acid and adsorbent, such a remarkable difference was attributed to the different nature of the interaction between amino acid and adsorbent. Arg could be readily adsorbed on the surface of SBA-15, especially Al-SBA-15, under appropriate pH in which the electrostatic interaction was predominant. The driving force of Phe adsorption on mesoporous adsorbent mainly came from the hydrophobic interaction. Therefore, the adsorption capability of Arg decreased with increasing ion strength of solution, while the adsorption capability of Phe increased with the increasing degree of CH3 functionalization on SBA-15. For neutral amino acid Phe, Ala, and Leu, the adsorption capability increased with the increase of the length of their side chains, which was another evidence of hydrophobic effect. Thus, all the adsorption of amino acids on mesoporous silica materials can be decided by the combined influence of two fundamental interactions: electrostatic attraction and hydrophobic effect.

  7. A bibliographical review on the radiolysis of uranyl nitrate solutions in nitric acid medium

    International Nuclear Information System (INIS)

    A bibliographical study on the effects of ionizing radiation on uranyl nitrate solutions in nitric acid medium was performed, and the state of knowledge on this subject is presented. The main experimental and theoretical results on water, nitric acid and uranium solutions radiolysis are reviewed and critically evaluated. This paper provides a collection of references as an aid to the development of practical applications, and to stimulate new research on fundamental processes in these systems. (author)

  8. Radiation-induced destruction peculiarities of hydroxyl containing amino acids in diluted aqueous solution

    International Nuclear Information System (INIS)

    Amino acids aqueous solution of alpha-alanine and beta-alanine, serine, threonine (concentration 5*10-4 M) were irradiated with dose rate 0.35 Gy/s in range 100-1100 Gy and analysed. Effectiveness of radiation-induced decomposition process depends on row of factors: concentration of amino acid aqueous solution, pH, oxygen presence and other acceptors

  9. Electrochemical study of benzene on Pt of various surface structures in alkaline and acidic solutions

    OpenAIRE

    Montilla Jiménez, Francisco; Morallón Núñez, Emilia; Vázquez Picó, José Luis

    2002-01-01

    The electrochemical behaviour of benzene on platinum electrodes (polycrystalline and single-crystal electrodes) has been studied in acidic and alkaline solutions. In acid solutions the reduction of benzene to cyclohexane takes place in all the platinum surface structure employed, however it does not occur in alkaline media (0.1 M NaOH). In this case, the hydrogen adsorption/desorption processes displace the adsorbed benzene from the electrode surface. The oxidation of benzene is also af...

  10. An investigation into the stability and sterility of citric acid solutions used for cough reflex testing.

    Science.gov (United States)

    Falconer, James R; Wu, Zimei; Lau, Hugo; Suen, Joanna; Wang, Lucy; Pottinger, Sarah; Lee, Elaine; Alazawi, Nawar; Kallesen, Molly; Gargiulo, Derryn A; Swift, Simon; Svirskis, Darren

    2014-10-01

    Citric acid is used in cough reflex testing in clinical and research settings to assess reflexive cough in patients at risk of swallowing disorders. To address a lack of knowledge in this area, this study investigated the stability and sterility of citric acid solutions. Triplicate solutions of citric acid (0.8 M) in isotonic saline were stored at 4 ± 2 °C for up to 28 days and analysed by high-performance liquid chromatography. Microbiological sterility of freshly prepared samples and bulk samples previously used for 2 weeks within the hospital was determined using a pour plate technique. Microbial survival in citric acid was determined by inoculating Staphylococcus aureus, Escherichia coli, or Candida albicans into citric acid solution and monitoring the number of colony-forming units/mL over 40 min. Citric acid solutions remained stable at 4 °C for 28 days (98.4 ± 1.8 % remained). The freshly prepared and clinical samples tested were sterile. However, viability studies revealed that citric acid solution allows for the survival of C. albicans but not for S. aureus or E. coli. The microbial survival study showed that citric acid kills S. aureus and E. coli but has no marked effect on C. albicans after 40 min. Citric acid samples at 0.8 M remained stable over the 4-week testing period, with viable microbial cells absent from samples tested. However, C. albicans has the ability to survive in citric acid solution if inadvertently introduced in practice. For this reason, in clinical and research practice it is suggested to use single-use aliquots prepared aseptically which can be stored for up to 28 days at 4 °C.

  11. SAVANNAH RIVER SITE TANK CLEANING: CORROSION RATE FOR ONE VERSUS EIGHT PERCENT OXALIC ACID SOLUTION

    Energy Technology Data Exchange (ETDEWEB)

    Ketusky, E.; Subramanian, K.

    2011-01-20

    Until recently, the use of oxalic acid for chemically cleaning the Savannah River Site (SRS) radioactive waste tanks focused on using concentrated 4 and 8-wt% solutions. Recent testing and research on applicable dissolution mechanisms have concluded that under appropriate conditions, dilute solutions of oxalic acid (i.e., 1-wt%) may be more effective. Based on the need to maximize cleaning effectiveness, coupled with the need to minimize downstream impacts, SRS is now developing plans for using a 1-wt% oxalic acid solution. A technology gap associated with using a 1-wt% oxalic acid solution was a dearth of suitable corrosion data. Assuming oxalic acid's passivation of carbon steel was proportional to the free oxalate concentration, the general corrosion rate (CR) from a 1-wt% solution may not be bound by those from 8-wt%. Therefore, after developing the test strategy and plan, the corrosion testing was performed. Starting with the envisioned process specific baseline solvent, a 1-wt% oxalic acid solution, with sludge (limited to Purex type sludge-simulant for this initial effort) at 75 C and agitated, the corrosion rate (CR) was determined from the measured weight loss of the exposed coupon. Environmental variations tested were: (a) Inclusion of sludge in the test vessel or assuming a pure oxalic acid solution; (b) acid solution temperature maintained at 75 or 45 C; and (c) agitation of the acid solution or stagnant. Application of select electrochemical testing (EC) explored the impact of each variation on the passivation mechanisms and confirmed the CR. The 1-wt% results were then compared to those from the 8-wt%. The immersion coupons showed that the maximum time averaged CR for a 1-wt% solution with sludge was less than 25-mils/yr for all conditions. For an agitated 8-wt% solution with sludge, the maximum time averaged CR was about 30-mils/yr at 50 C, and 86-mils/yr at 75 C. Both the 1-wt% and the 8-wt% testing demonstrated that if the sludge was removed

  12. Interfacial structures of acidic and basic aqueous solutions

    International Nuclear Information System (INIS)

    Phase-sensitive sum-frequency vibrational spectroscopy was used to study water/vapor interfaces of HCl, HI, and NaOH solutions. The measured imaginary part of the surface spectral responses provided direct characterization of OH stretch vibrations and information about net polar orientations of water species contributing to different regions of the spectrum. We found clear evidence that hydronium ions prefer to emerge at interfaces. Their OH stretches contribute to the 'ice-like' band in the spectrum. Their charges create a positive surface field that tends to reorient water molecules more loosely bonded to the topmost water layer with oxygen toward the interface, and thus enhances significantly the 'liquid-like' band in the spectrum. Iodine ions in solution also like to appear at the interface and alter the positive surface field by forming a narrow double-charge layer with hydronium ions. In NaOH solution, the observed weak change of the 'liquid-like' band and disappearance of the 'ice-like' band in the spectrum indicates that OH- ions must also have excess at the interface. How they are incorporated in the interfacial water structure is however not clear

  13. Antimicrobial and cytotoxic effects of phosphoric acid solution compared to other root canal irrigants

    Directory of Open Access Journals (Sweden)

    Maíra PRADO

    2015-04-01

    Full Text Available Phosphoric acid has been suggested as an irrigant due to its effectiveness in removing the smear layer. Objectives : The purpose of this study was to compare the antimicrobial and cytotoxic effects of a 37% phosphoric acid solution to other irrigants commonly used in endodontics. Material and Methods : The substances 37% phosphoric acid, 17% EDTA, 10% citric acid, 2% chlorhexidine (solution and gel, and 5.25% NaOCl were evaluated. The antimicrobial activity was tested against Candida albicans, Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Actinomyces meyeri, Parvimonas micra, Porphyromonas gingivalis, and Prevotella nigrescens according to the agar diffusion method. The cytotoxicity of the irrigants was determined by using the MTT assay. Results : Phosphoric acid presented higher antimicrobial activity compared to the other tested irrigants. With regard to the cell viability, this solution showed results similar to those with 5.25% NaOCl and 2% chlorhexidine (gel and solution, whereas 17% EDTA and 10% citric acid showed higher cell viability compared to other irrigants. Conclusion : Phosphoric acid demonstrated higher antimicrobial activity and cytotoxicity similar to that of 5.25% NaOCl and 2% chlorhexidine (gel and solution.

  14. Dry dilute acid pretreatment by co-currently feeding of corn stover feedstock and dilute acid solution without impregnation.

    Science.gov (United States)

    He, Yanqing; Zhang, Jian; Bao, Jie

    2014-04-01

    Impregnation of lignocellulose materials with dilute acid solution is a routine operation in conventional dilute acid pretreatment. The dry dilute acid pretreatment (DDAP) at high solids content up to 70% is naturally considered to require longer impregnation time. In this study, a co-currently feeding operation of corn stover and dilute sulfuric acid solution without any impregnation was tested for DDAP. The DDAP pretreated corn stover without impregnation is found to be essentially no difference in pretreatment efficiency compared to those with impregnation in the helically agitated reactor. The yield from cellulose to ethanol in SSF again shows no obvious difference between the DDAP pretreated corn stover with and without impregnation. This study suggests that impregnation in DDAP was not necessary under the helical agitation mixing. The results provided a useful way of cost reduction and process simplification in pretreatment.

  15. Dry dilute acid pretreatment by co-currently feeding of corn stover feedstock and dilute acid solution without impregnation.

    Science.gov (United States)

    He, Yanqing; Zhang, Jian; Bao, Jie

    2014-04-01

    Impregnation of lignocellulose materials with dilute acid solution is a routine operation in conventional dilute acid pretreatment. The dry dilute acid pretreatment (DDAP) at high solids content up to 70% is naturally considered to require longer impregnation time. In this study, a co-currently feeding operation of corn stover and dilute sulfuric acid solution without any impregnation was tested for DDAP. The DDAP pretreated corn stover without impregnation is found to be essentially no difference in pretreatment efficiency compared to those with impregnation in the helically agitated reactor. The yield from cellulose to ethanol in SSF again shows no obvious difference between the DDAP pretreated corn stover with and without impregnation. This study suggests that impregnation in DDAP was not necessary under the helical agitation mixing. The results provided a useful way of cost reduction and process simplification in pretreatment. PMID:24630497

  16. Survival mechanism of Escherichia coli O157:H7 against combined treatment with acetic acid and sodium chloride.

    Science.gov (United States)

    Lee, Sun-Young; Kang, Dong-Hyun

    2016-05-01

    The combination of salt and acid is commonly used in the production of many foods, including pickles and fermented foods. However, in our previous studies, the addition of salt significantly reduced the inhibitory effect of acetic acid on Escherichia coli O157:H7 in laboratory media and pickled cucumbers. Therefore, this study was conducted to determine the mechanism by which salt confers resistance against acetic acid in E. coli O157:H7. The addition of high concentrations (up to 9% or 15% [w/v]) of salt increased the resistance of E. coli O157:H7 to acetic acid treatment. Combined treatment with acetic acid and salt showed varying results among different bacterial strains (an antagonistic effect for E. coli O157:H7 and Shigella and a synergistic effect for Listeria monocytogenes and Staphylococcus aureus). The addition of salt increased the cytoplasmic pH of E. coli O157:H7, but decreased the cytoplasmic pH of L. monocytogenes and S. aureus on treatment with acetic acid. Therefore, the addition of salt increases the acid resistance of E. coli O157:H7 possibly by increasing its acid resistance response and consequently preventing the acidification of its cytoplasm by organic acids. PMID:26742620

  17. Survival mechanism of Escherichia coli O157:H7 against combined treatment with acetic acid and sodium chloride.

    Science.gov (United States)

    Lee, Sun-Young; Kang, Dong-Hyun

    2016-05-01

    The combination of salt and acid is commonly used in the production of many foods, including pickles and fermented foods. However, in our previous studies, the addition of salt significantly reduced the inhibitory effect of acetic acid on Escherichia coli O157:H7 in laboratory media and pickled cucumbers. Therefore, this study was conducted to determine the mechanism by which salt confers resistance against acetic acid in E. coli O157:H7. The addition of high concentrations (up to 9% or 15% [w/v]) of salt increased the resistance of E. coli O157:H7 to acetic acid treatment. Combined treatment with acetic acid and salt showed varying results among different bacterial strains (an antagonistic effect for E. coli O157:H7 and Shigella and a synergistic effect for Listeria monocytogenes and Staphylococcus aureus). The addition of salt increased the cytoplasmic pH of E. coli O157:H7, but decreased the cytoplasmic pH of L. monocytogenes and S. aureus on treatment with acetic acid. Therefore, the addition of salt increases the acid resistance of E. coli O157:H7 possibly by increasing its acid resistance response and consequently preventing the acidification of its cytoplasm by organic acids.

  18. The solubility of thorium fluoride in nitric acid-hydrofluoric acid solution between 25 and 1000C

    International Nuclear Information System (INIS)

    The solubility of thorium fluoride in 4, 8, and 13 M nitric acid solutions was measured as a function of fluoride concentration at 25, 50 and 1000C. The behavior of the solubility is best explained by the existence in solution of the species ThFsub(n)sup((4-n)+), where n has values between 0 and 4. Equilibrium quotients for the stepwise complexation of thorium by fluoride are calculated. (author)

  19. Change in the amino acid composition of calf skin collagen after. gamma. -irradiation in aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Duzhenkova, N.A.; Savich, A.V. (Institut Biofiziki, Moscow (USSR))

    A study was made of the amino acid composition of calf skin collagen after ..gamma..-irradiation (/sup 60/Co) of 2.5x10/sup -6/ M aerated aqueous protein solution within the dose range from 30 to 2000 Gy. The radiosensitivity of amino acid residues was compared.

  20. Oxidation of molybdenite with oxygen in nitrogen-sulfuric acid solutions

    International Nuclear Information System (INIS)

    Results of bench testing on molybdenite decomposition at nitric acid discharge below stoichiometric, at atmospheric pressure with total molybdenum conversion into the solution are described. Influence of sulfuric acid mixed with nitric one on molybdenum solubility and concentrate decomposition rate is studied