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Sample records for chloride solution comportamiento

  1. 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.

  2. Hydrolysis of ferric chloride in solution

    International Nuclear Information System (INIS)

    The Detox trademark process uses concentrated ferric chloride and small amounts of catalysts to oxidize organic compounds. It is under consideration for oxidizing transuranic organic wastes. Although the solution is reused extensively, at some point it will reach the acceptable limit of radioactivity or maximum solubility of the radioisotopes. This solution could be cemented, but the volume would be increased substantially because of the poor compatibility of chlorides and cement. A process has been developed that recovers the chloride ions as HCl and either minimizes the volume of radioactive waste or permits recycling of the radioactive chlorides. The process involves a two-step hydrolysis at atmospheric pressure, or preferably under a slight vacuum, and relatively low temperature, about 200 degrees C. During the first step of the process, hydrolysis occurs according to the reaction below: FeCl3liquid + H2O → FeOClsolid + 2 HClgas During the second step, the hot, solid, iron oxychloride is sprayed with water or placed in contact with steam, and hydrolysis proceeds to the iron oxide according to the following reaction: 2 FeOClsolid + H2O → Fe2O3solid + 2 HClgas. The iron oxide, which contains radioisotopes, can then be disposed of by cementation or encapsulation. Alternately, these chlorides can be washed off of the solids and can then either be recycled or disposed of in some other way

  3. 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)

  4. Hydrolysis of ferric chloride in solution

    Energy Technology Data Exchange (ETDEWEB)

    Lussiez, G.; Beckstead, L.

    1996-11-01

    The Detox{trademark} process uses concentrated ferric chloride and small amounts of catalysts to oxidize organic compounds. It is under consideration for oxidizing transuranic organic wastes. Although the solution is reused extensively, at some point it will reach the acceptable limit of radioactivity or maximum solubility of the radioisotopes. This solution could be cemented, but the volume would be increased substantially because of the poor compatibility of chlorides and cement. A process has been developed that recovers the chloride ions as HCl and either minimizes the volume of radioactive waste or permits recycling of the radioactive chlorides. The process involves a two-step hydrolysis at atmospheric pressure, or preferably under a slight vacuum, and relatively low temperature, about 200{degrees}C. During the first step of the process, hydrolysis occurs according to the reaction below: FeCl{sub 3 liquid} + H{sub 2}O {r_arrow} FeOCl{sub solid} + 2 HCl{sub gas} During the second step, the hot, solid, iron oxychloride is sprayed with water or placed in contact with steam, and hydrolysis proceeds to the iron oxide according to the following reaction: 2 FeOCl{sub solid} + H{sub 2}O {r_arrow} Fe{sub 2}O{sub 3 solid} + 2 HCl{sub gas}. The iron oxide, which contains radioisotopes, can then be disposed of by cementation or encapsulation. Alternately, these chlorides can be washed off of the solids and can then either be recycled or disposed of in some other way.

  5. 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

  6. 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.

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

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    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.

  8. 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 ...

  9. Platinum uptake from chloride solutions using biosorbents

    OpenAIRE

    Mehmet Hakan Morcali; Bihter Zeytuncu; Onuralp Yucel

    2013-01-01

    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...

  10. 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.

  11. 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

  12. 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...

  13. 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.

  14. Lead sulphate leaching by sodium chloride solution

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    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.

  15. 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...

  16. 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

  17. 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...

  18. 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...

  19. Soret diffusion processes in aqueous sodium chloride solutions

    Energy Technology Data Exchange (ETDEWEB)

    Cygan, R.T.

    1985-01-01

    The mass transport of chemical species induced by a temperature gradient, commonly known as Soret diffusion, has been examined for the case of the sodium chloride and water system. The occurrence of significant thermal gradients in geological media, especially those associated with radioactive waste disposal sites, can produce a measurable flux of sodium chloride and therefore enrich the local solutions. Soret coefficients, or the ratio of thermal to isothermal mass transport factors, describe this rate of mass transfer and are necessary for evaluating certain nonequilibrium processes, such as the migration of fluid inclusions in rock salt. Experimental Soret coefficients for the NaCl-H/sub 2/O system were obtained by the use of a conductimetric thermal diffusion cell. This approach relies on monitoring the electrical conductivity change of two separate isothermal reservoirs which are maintained at different temperatures. The Soret cell is situated between the reservoirs and is comprised of an inert matrix of glass beads in order to minimize any solution convection. The utilization of this porous medium requires corrections for porosity and tortuosity. Measurements were made for 0.1 and 1.0 N NaCl solutions at mean temperatures of 40/sup 0/C and 50/sup 0/C with the mass transport induced by a thermal gradient of 2.6/sup 0/C/cm. The preliminary results indicate a Soret separation on the order of 1 to 2 percent with the attainment of a steady state in approximately 15 hours.

  20. Substituted sodium phenylanthranylates as inhibitors of corrosion in chloride solutions

    Energy Technology Data Exchange (ETDEWEB)

    Kuznetsov, Yu.I.; Fialkov, Yu.A.; Popova, L.I.; Ehndel' man, E.S.; Kuznetsova, I.G. (AN SSSR, Moscow. Inst. Fizicheskoj Khimii)

    The efficiency of corrosion protection of armco iron, zinc (Ts-O) aluminium (AB 000) and its alloys (.D16 and AMG6) with sodium phenylanthranylate derivatives in chloride buffer solutions (pH 7.4-8.08) are investigated. It has been ascertained that the introduction of sodium phenylanthranylate into phenyl radical in m- and p-position relative to the amino group of electron-seeking substitutes improves protective properties of an inhibitor. The inhibiting effect of phenylanthranylates and its dependence on electron structure enchances in zinc-aluminium-iron series and decreases in case of transition from pure aluminium to its alloys.

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

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    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

  2. Production of Reactor Fuel Oxides from Molten Chloride Salt Solutions

    International Nuclear Information System (INIS)

    Hanford Laboratories' work on reprocessing concepts for spent UO2-PuO2 fuels has led to the development of attractive, synthesis methods for several reactor fuel oxides possessing unique properties. By the use of molten chloride salt solutions as reaction media, it has been found possible to produce crystalline uranium and plutonium dioxides, and solid solutions of various oxide mixtures, at relatively low temperatures (500 to 750 deg. C). Exploratory work has indicated that these techniques may also be quite useful in the preparation of other nonmetallic fuel materials. Crystalline UO2 has been prepared by electrodeposition from molten chloride salt solutions of uranyl chloride. Material with oxygen-uranium ratios as low as 2.0006 and crystal densities as high as 10.92 (99.5% of the theoretical value) has been produced both in the laboratory and in 100-lb pilot-plant lots. This oxide appears well suited to such fuel element fabrication techniques as vibratory compaction. In carefully controlled laboratory-scale work, single crystals have been prepared weighing as much as 4 g. Conditions have also been worked out for the electro deposition of polycrystalline cylindrical UO2 rods. The intensive engineering studies have contributed markedly to the technology of containing and handling molten salts under chemical processing conditions and have provided a basis for preliminary cost studies which indicate that, with potential advances in technology, this method of preparation of dense UO2 may well compete economically with other established methods. Dense, black, finely divided crystals of UO2 with a bulk density greater than 6 g/cm3 have been produced by precipitation from molten salt media, under carefully selected conditions of salt composition, temperature, and sparge gas. It is anticipated that crystal growth can be controlled so as to give optimum particle-size distribution for fabrication of mixed oxide fuel elements. UO2-PuO2 and UO2-ThO2 solid solutions

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

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    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.

  4. 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.

  5. 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.

  6. Passivity of Alloy 22 in Chloride and Fluoride Containing Solutions

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-06-07

    The aim of the present work was to study the passive behavior of Alloy 22 in chloride and fluoride containing solutions varying the heat treatment of the alloy, the halide concentration and the pH of the solution at 90 C. General corrosion behavior was studied using electrochemical techniques, which included open circuit potential monitoring over time, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) measurements carried out at open circuit and at passive potentials. Corrosion rates obtained by EIS measurements after 24 h immersion were below 0.5 {micro}m/year. The corrosion rates were practically independent of the solution pH, short term corrosion potential (E{sub corr}), alloy heat treatment and halide ion nature and concentration. Polarization resistance (R{sub P}) values increased with open circuit potential and the polarization time at constant potential in 1M NaCl, pH 6, 90 C. This was attributed to an increase in the oxide film thickness and oxide film aging. Capacitance measurements indicated that passive oxide on Alloy 22 presented a double n-type/p-type semiconductor behavior in the passive potential range.

  7. 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)

  8. Stress corrosion cracking of austenitic stainless steel in glycerol solution and chloride solution at elevated temperature

    International Nuclear Information System (INIS)

    Stress Corrosion Cracking (SCC) is an environmentally assisted failure caused by exposure to a corrodant while under a sustained tensile stress. SCC is most often rapid, unpredictable and catastrophic. Failure can occur in as little as a few hours or take years to happen. Most alloys are susceptible to SCC in one or more environments requiring careful consideration of alloy type in component design. In aqueous chloride environments austenitic stainless steels and many nickel based alloys are known to perform poorly. One of products Oleo chemical is glycerol solution. Glycerol solution contains chloride with concentration 50 ppm - 150 ppm. Austenitic stainless steel is usually used in distillation construction tank and pipe line of glycerol. Material AISI 304 will be failure in this glycerol solution with this concentration in 5 years. In production process, concentration of chloride in glycerol becomes more than 150 ppm at temperature 150 degree Celsius. The reason is that the experiment I conducted in high chloride with concentration such as 6000 ppm, 9000 ppm, and 12000 ppm. The stress corrosion cracking of the austenitic stainless steels of types AISI 304, 316 and 316L in glycerol solution at elevated temperature 150 degree Celsius is investigated as a function variation of chloride concentration, namely 50, 6000, 9000 and 12000 ppm using a constant load method with two kinds of initial tensile stress as 50 % and 70 % yield strength. The experiment uses a spring loaded fixture type and is based on ASTM G49 for experiment method, and E292 for geometry of specimen. Pitting corrosion occurs on the surface specimen until the stress level reaches the ultimate strength. Pitting corrosion attack and depletion occur on the surface as initiation of SCC failure as the stress reaches the ultimate strength. Failure has occurred in catastrophic brittle fracture type of transgranular. AISI 304 was more susceptible for all conditions. In chloride solution with concentration of

  9. Pourbaix Diagrams for Copper in 5 m Chloride Solution

    International Nuclear Information System (INIS)

    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, 10-4 and 10-6 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 CuCl32- in acid and alkaline solutions. At higher potentials in acid solutions CuCl32- is oxidized to CuCl2(aq), which at increasing potentials can form CuCI+, Cu2+ or CuClO3+. Copper passivates by formation of Cu2O(cr), CuO(cr), or CUO2 3 Cu(OH)2(s). Cu2O(cr) does not form at [Cu(aq)]tot = 10-6 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)]tot = 10-4 molal and at 80-100 deg C at [Cu(aq)]tot = 10-6 molal. Copper at the anticipated repository potentials and pH can corrode at 80 deg C at [Cu(aq)]tot = 10-4 molal and at 50 deg C at [Cu(aq)]tot = 10-6 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 mechanism. However, this is only valid if no macro cracks occur in the clay. The auto-stop is valid for the initial, main and cooling phases. During a glacial

  10. Extraction of scandium by benzoylantipyrine from chloride-perchlorate solutions

    International Nuclear Information System (INIS)

    Distribution of scandium complexes in case of extraction by benzoyl-4-antipyrine (BANT) in chloroform from aqueous chloride-perchlorate solutions, depending on extraction, perchlorate-ion and salting out agents concentration, was studied. It has been ascertained that scandium distribution factor is nearly 50 at NaClO4 and BANT concentrations equal to 2 and 0.1 mol/l respectively. Introduction of salting out agents (NaCl, CaCl2) and HCl at a constant content of NaClO4 (0.5 mol/l) increases noticeably scandium extraction. For 0.1 mol/l BANT solution in chloroform the extraction capacity in terms of scandium makes up 1.26 g/l. The optimal conditions for the element extraction have been found, the composition of the complex extracted has been ascertained (Sc:BANT:ClO4- = 1:3:3) and extraction mechanism has been suggested. Influence of interfering elements on scandium distribution factor was studied

  11. 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

  12. 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.

  13. 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.

  14. Uranium(VI) extraction from chloride solution with benzyloctadecyldimethyl ammonium chloride (BODMAC) in a liquid membrane process

    International Nuclear Information System (INIS)

    The recovery of uranium(VI) from chloride solution using a liquid emulsion membrane (LEM) technique was studied. The emulsion is constituted by the quaternary salt of benzyloctadecyldimethyl ammonium chloride (BODMAC, R4NCl) as a carrier, kerosene as organic diluent, Span 80 as emulsifying agent and 0.5 mol/l Na2CO3 as stripping phase. The important variables affecting the LEM permeation process such as the concentrations of extractant, internal strip phase, types of organic diluent, and the presence of magnesium chloride or magnesium sulfate were investigated. It was found that, at a given condition, the maximum extraction rate of uranium(VI) reached 80%. The emulsion was stable at low pH in the presence of certain amounts of electrolytes such as NaCl and MgCl2. (author)

  15. 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)

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.)

  1. 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.)

  2. Electrodeposition of cerium from aqueous cerous chloride solutions

    International Nuclear Information System (INIS)

    Cerium was plated as a grey, metallic, adherent deposit from aqueous cerous chloride baths containing certain organic addition agents. The cathodic current efficiency was determined for each case. Chemical analysis indicates that the purity of the metal is better than 99.0 per cent. (author). 7 refs

  3. The isolation of beryllium and mercury from lithium chloride solution by means of gas extraction

    International Nuclear Information System (INIS)

    The possibility and optimal conditions of beryllium and mercury extraction using acetylacetone (HAA) from lithium chloride solution by argon blowing through the solution are determined. Dependences of extraction degrees and distribution coefficients on different parameters of liquid phase: initial pH value, lithium chloride concentration and initial content of HAA, are presented. The degree of beryllium extraction reaches the maximum at liquid phase pH of 4.4-5.25 and concentration of lithium chloride of 8.5 mol/l. Distribution coefficient changes in inverse proportion to the extraction degree

  4. Chemical characterization of a potassium hydroxyapatite prepared by soaking in potassium chloride and carbonate solutions.

    Science.gov (United States)

    Nordström, E G; Karlsson, K H

    1992-01-01

    A potassium-doped synthetic apatite was prepared by soaking hydroxyapatite in potassium carbonate and potassium chloride solutions. The hydroxyapatite was prepared by firing slip cast ceramic bodies in vacuum at 1100 degrees C. The conical ceramic samples and a crushed material of this were soaked in carbonate and chloride solutions for 2, 4, 6, and 8 weeks. Potassium, calcium, and phosphate were determined by direct current plasma emission spectroscopy. The carbonate content was determined by thermogravimetric analysis and chloride titrimetrically. After 2 weeks, one potassium ion substituted one calcium ion when soaked in a carbonate solution. When soaked in the chloride solution substitution occurred to the same extent. At phosphate sites the substitution of phosphate for carbonate occurred at one sixth of the sites after 2 weeks. Chloride incorporated one half of the OH-sites after 2 weeks. After 4 weeks about one chloride ion was found in the apatite, and after 6 weeks one and a half of the OH-sites were occupied by chloride ions. PMID:1483120

  5. 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)

  6. Effect of different ions on the anodic behaviour of alloy 800 chloride solutions at high temperature

    International Nuclear Information System (INIS)

    The anodic behaviour and passivity breakdown of alloy 800 in sodium bicarbonate and sodium phosphate aqueous solutions were studied in the temperature range from 100 degrees C to 280 degrees C by means of electrochemical techniques. The effect of phosphate or bicarbonate additions on the pitting susceptibility and pitting morphology of the alloy in chloride solutions was also examined. Experiments were performed in the following solutions: 0.1M NaHCO3, at 100 degrees C, 200 degrees C, 280 degrees C; 0.06M NaH2PO4 + 0.04M Na2HPO4, at 100 degrees C, 200 degrees C and 280 degrees C, and 0.1M NaCl with different additions of bicarbonate ion (0.02M, 0.05M and 0.1M) and phosphate ion (0.01M, 0.05M and 0.1M) at 100 degrees C and 280 degrees C. The anodic polarization curves of alloy 800 in deaerated 0.1M NaHCO3 and 0.06M NaH2PO4 + 0.04M Na2HPO4 solutions exhibited a similar shape at all the tested temperatures. No localized or generalized corrosion was detected on the metallic surface after polarization. The results obtained in chloride plus bicarbonate and chloride plus phosphate mixtures showed that the pitting potential of alloy 800 in chloride solutions was increased by the presence of bicarbonate or phosphate ions. In those solutions where the inhibitor concentration in the mixture is equal or higher than the chloride concentration , the behaviour of the alloy is similar to the one observed in the absence of chlorides. Changes in pitting morphology were found in phosphate containing solutions, while the pits found in bicarbonate containing solutions were similar to those formed in pure chloride solutions. (author). 3 refs., 4 figs

  7. 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.

  8. Interaction between lactose and cadmium chloride in aqueous solutions as seen by diffusion coefficients measurements

    International Nuclear Information System (INIS)

    Highlights: ► Diffusion coefficients of aqueous systems containing lactose and cadmium chloride. ► Influence of the lactose on the diffusion of cadmium chloride. ► Interactions between Cd2+ and lactose. -- Abstract: Diffusion coefficients of an aqueous system containing cadmium chloride 0.100 mol · dm−3 and lactose at different concentrations at 25 °C have been measured, using a conductimetric cell and an automatic apparatus to follow diffusion. The cell relies on an open-ended capillary method and a conductimetric technique is used to follow the diffusion process by measuring the resistance of a solution inside the capillaries, at recorded times. From these results and by ab initio calculations, it was possible to obtain a better understanding of the effect of lactose on transport of cadmium chloride in aqueous solutions

  9. 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...

  10. 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...

  11. 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.)

  12. 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.

  13. 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.

  14. 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.

  15. Control and monitoring of the localized corrosion of zirconium in acidic chloride solutions

    International Nuclear Information System (INIS)

    Zirconium in acidic chloride solutions which are contaminated with ferric or cupric cations is prone to localized corrosion. This tendency can be reduced by ensuring that the zirconium surface is clean and smooth. In this paper, the effect of surface condition on the localized corrosion of zirconium in acidic chloride solutions is predicted with potentiodynamic scans. These predictions are confirmed by weight loss tests on various combinations of surface finish and acid concentrations. A real time indication of localized corrosion is seen by monitoring the electrochemical noise produced between two similar electrodes immersed in an acidic chloride solutions. Electrochemical noise monitoring correlates well with the predictions from potentiodynamic and weight loss experiments. The electrochemical noise results show that while an elevated (more anodic) potential caused by ferric ion contamination may be a necessary condition for localized corrosion, it is not a sufficient condition: A smooth, clean zirconium surface reduces the localized corrosion of zirconium

  16. Zinc chloride aqueous solution as a solvent for starch.

    Science.gov (United States)

    Lin, Meiying; Shang, Xiaoqin; Liu, Peng; Xie, Fengwei; Chen, Xiaodong; Sun, Yongyi; Wan, Junyan

    2016-01-20

    It is important to obtain starch-based homogeneous systems for starch modification. Regarding this, an important key point is to find cheap, low-cost and low-toxicity solvents to allow complete dissolution of starch and its easy regeneration. This study reveals that a ZnCl2 aqueous solution is a good non-derivatizing solvent for starch at 50 °C, and can completely dissolve starch granules. The possible formation of a "zinc-starch complex" might account for the dissolution; and the degradation of starch, which was caused by the H(+) inZnCl2 aqueous solution, could not contribute to full dissolution. From polarized light microscopic observation combined with the solution turbidity results, it was found that the lowest ZnCl2 concentration for full dissolution was 29.6 wt.% at 50 °C, with the dissolving time being 4h. Using Fourier-transform infrared (FTIR), solid state (13)C nuclear magnetic resonance (NMR), and X-ray diffraction (XRD), it was revealed that ZnCl2 solution had no chemical reaction with starch glucosides, but only weakened starch hydrogen bonding and converted the crystalline regions to amorphous regions. In addition, as shown by intrinsic viscosity and thermogravimetric analysis (TGA), ZnCl2 solution caused degradation of starch macromolecules, which was more serious with a higher concentration of ZnCl2 solution. PMID:26572355

  17. 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.

  18. 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

  19. Modeling of extraction equilibrium of Zn(II) from chloride solutions using TBP

    International Nuclear Information System (INIS)

    Zinc protective layers are commonly used to protect steel goods from corrosion. Solvent extraction and ion exchange can be used to remove zinc(II) from spent pickling solutions. The aim of presented work was to perform the detailed studies with tributyl phosphate taking into account different concentrations of zinc(II) and high concentrations both of proton and chloride ions. The obtained extraction isotherms of Zn(II) from chloride solutions were used to modeling extraction equilibrium, and equilibrium constant were calculated. The obtained results shown that zinc(II) could be effectively stripped from the organic phase with water

  20. 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

  1. 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

    This study focused on developing a surface cleaning treatment for one type of commercially available plasticized poly(vinyl chloride). The effects of cleaning solutions on samples of plasticized poly(vinyl chloride) were examined by several methods. The sample surface, prior to and after artificial...... 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 by...... cleaning methods for plasticized poly(vinyl chloride) objects....

  2. 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....

  3. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    You, D.; Lefefre, S.; Feron, D. [CEA-Saclay, Lab. d' Etude de la Corrosion Aqueuse, Gif-sur-Yvette (France); Vaillant, F. [EDF-Les Renardieres - DRD/EMA, Moret-sur-Loing (France)

    2002-07-01

    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)

  5. 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)

  6. 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.

  7. 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.)

  8. Crevice corrosion behaviour of titanium grades-2 and -12 in hot aqueous chloride solution - the effect of chloride concentration

    International Nuclear Information System (INIS)

    The crevice corrosion of Grades-2 (Ti-2) and -12 titanium (Ti-12) has been studied at a temperature of 150oC in solutions ranging in sodium chloride concentration from 0.27 mol·L-1 to 5.0 mol·L-1. A technique in which an artificially creviced electrode was coupled through a zero resistance ammeter to a large counter electrode was used to follow the potential of the crevice specimen and the coupled current due to oxygen reduction on the coupled electrode. The total amount of crevice corrosion which occurred on the specimen was estimated from weight change measurements. The depth of penetration due to crevice corrosion was measured using a combination of metallographic and image analysis techniques. Crevice corrosion of Ti-2 continued, without repassivation, until all the oxygen within the sealed pressure vessel system was exhausted. The weight change was proportional to the maximum depth of penetration and corrosion was observed to be quite generally distributed throughout the creviced area. Corrosion profiles (i.e., percentage of the creviced area corroded versus the depth of penetration) show a localized corrosion process preceding a more general corrosion front. The extent and rate of crevice propagation and the depth of maximum penetration, all decrease with increasing chloride concentration, but their dependence on this concentration is not major. By comparison, both the extent and rate of crevice corrosion of Ti-12 are dependent on chloride concentration increasing substantially for concentrations >0.5 mol·L-1 but decreasing again for concentrations >3.0 mol·L-1. However, at all chloride concentrations, the crevice repassivated before all the available oxygen was depleted; i.e., the extent of crevice corrosion is severely limited. Measurements of the depths of corrosion penetration show that, for Ti-12, penetration within the crevice occurs much more locally than for Ti-2. In fact, if a general corrosion front can be discerned at all, it is ∼10

  9. 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).

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

    OpenAIRE

    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 more than 1%. The titration and calculation takes less than 20 min.

  11. 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).

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. Behaviour of rare platinum metals during precipitation from chloride solutions by sulfur liquor

    International Nuclear Information System (INIS)

    Sulfide precipitation of ruthenium, rhodium and iridium for their supplementary extraction from chloride solutions is studied. The behaviour of rare platinum metals (RPM) under the action on their chloride solutions of sulfer liquor mainly consisting of NaSsub(x) polysulfides, is related to the formation of sulfides and soluble thiosalts. The ratio of the forms depends on pH value. In the series Ir-Rh-Ru the tendency for sulfide formation increases, and thiosalt stability decreases. The treatment of the solutions by sulfur liquor with subsequent correction of pH value permits to extract RPM into precipitate quite completely, at that, RPM residual concentration in mother liquor does not exceed 0.5-0.7 mg/l. It is pointed out, that under the conditions studied only ruthenium is precipitated quantitatively, for which the following parameters can be considered optimal: 80-100 deg C, pH=1-2, the process duration 60-90 min

  18. 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.

  19. Crevice Corrosion Susceptibility of Alloy 22 in Fluoride and Chloride Containing Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Day, S D; Rebak, R B

    2004-11-22

    Alloy 22 (N06022) is highly resistant to crevice corrosion in pure chloride (Cl{sup -}) solutions. Little research has been conducted to explore the resistance of this alloy to other halides such as fluoride (F{sup -}) and bromide (Br{sup -}). Even less information is available exploring the behavior of localized corrosion for Alloy 22 in mixtures of the halide ions. Standard electrochemical tests such as polarization resistance and cyclic potentiodynamic polarization (CPP), were conducted to explore the resistance to corrosion of Alloy 22 in deaerated aqueous solutions of 1 M NaCl, 1 M NaF and 0.5 M NaCl + 0.5 M NaF solutions at 60 C and 90 C. Results show that the general corrosion rate was the lowest in the mixed halide solution and the highest in the pure chloride solution. Alloy 22 was not susceptible to localized corrosion in the pure fluoride solution. In 1 M NaCl solution, Alloy 22 was susceptible to crevice corrosion at 90 C. In the mixed halide solution Alloy 22 was susceptible to crevice corrosion both at 60 C and 90 C.

  20. 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

  1. Phase equilibrium of methane hydrate in silica sand containing chloride salt solution

    International Nuclear Information System (INIS)

    Highlights: • Methane hydrate equilibria in silica sand-ionic solution are obtained. • Hydrate equilibria in fine sand-solution shift more than single sand or solution. • Electrostatic and capillary forces affect hydrate equilibria in fine sand-solution. • Hydrate equilibria in coarse sand-solution agree with those in single solution. • Hydrate equilibria in coarse sand-solution are mainly affected by ions. - Abstract: Hydrate equilibrium is the most important foundation for other hydrate issues, especially for marine environment condition. In this work, the silica sand containing NaCl/MgCl2/CaCl2 aqueous solution were used to simulate marine sediment for investigating methane hydrate equilibrium using isochoric multi-step heating dissociation method. All measurements were performed in a temperature and pressure range of (279.5 to 289.7) K and (8.32 to 17.52) MPa, respectively. The results suggest that the equilibrium of methane hydrate in fine-grained silica sand containing chloride salt solution shifts more greatly to the left relative to that in single silica sand or solution. This is because water molecules reduce more chances to combine with gas molecules that is caused by the capillary force and the electrostatic attractions from the surface and electrolyte ions. However, hydrate equilibrium in coarse-grained silica sand containing chloride salt solution is in rough agreement with that in ionic solution of the corresponding concentration that indicates that hydrate equilibrium is mainly influenced by ions while the impact of solid particles is negligible

  2. 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...

  3. 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...

  4. 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.

  5. 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...

  6. 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...

  7. Hydration of the chloride ion in concentrated aqueous solutions using neutron scattering and molecular dynamics

    Czech Academy of Sciences Publication Activity Database

    Pluhařová, Eva; Fischer, H. E.; Mason, Philip E.; Jungwirth, Pavel

    2014-01-01

    Roč. 112, 9/10 (2014), s. 1230-1240. ISSN 0026-8976 R&D Projects: GA ČR GBP208/12/G016; GA MŠk LH12001 Grant ostatní: GA MŠk(CZ) LM2010005 Institutional support: RVO:61388963 Keywords : lithium * solution * molecular dynamics * chloride * neutron scattering Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.720, year: 2014

  8. 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...

  9. 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...

  10. 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...

  11. Effect of chloride ions on the corrosion and electrochemical behavior of titanium in neutral solutions

    Energy Technology Data Exchange (ETDEWEB)

    Mandzhgaladze, S.N. (Inst. of Metallurgy, Tbilisi, USSR); Mikaberidze, M.P.; Pirtskhalava, D.N.; Vasil' ev, Yu.B.; Bagotskii, V.S.

    1976-01-01

    A solution of NaCl was buffered with a phosphate buffer, and the potential was measured relative to a saturated silver chloride electrode. Polarization curves for cathodically reduced and oxidized titanium are shown, as well as the effect of NaCl concentration on the corrosion current, the steady-state corrosion potential, the cathodic currents, and the anodic currents for cathodically reduced and anodically oxidized titanium. The corrosion potential for oxidized titanium is strongly shifted in the positive direction, and the corrosion current and the dissolution current in the passive state are almost 10 times higher than for prereduced titanium. The different effects of the chloride ions on the rates of the cathode and anode processes result in a practically constant corrosion current for cathodically reduced titanium when c/sub Cl/sup -// less than 5 N. In the case of the oxidized titanium surface, the simultaneous increase in the rate of both the cathode and the anode process with increasing chloride ion concentration results in the increase of the corrosion current proportional to a fractional power of the bulk chloride ion concentration. 2 figures. (RWR)

  12. 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.

  13. 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

  14. 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...

  15. 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%.

  16. 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.

  17. Reasons for different solubility of alkali metal chlorides in cadmium nitrate solutions

    International Nuclear Information System (INIS)

    Maximum solubility of MCl salts (M=Li, Na, K, Cs) in solutions of cadmium nitrate and perchlorate of different concentration was measured in detail for studying the reason for different solubility of alkali metal chlorides in aqueous solutions of cadmium nitrate with concentration of 0.9 and 4.1 mol/l. It is shown that in the framework of phenomenological model of the solutions concentrated solutions of salts forming several crystallohydrates can be considered as a system of mixed solvents. In this case, preferable interaction of LiCl and CsCl with the Cd(NO3)2·9H2O type solvent, while NaCl and KCl - with the Cd(NO3)2·4H2O type solvent can be mentioned

  18. Sulphate analysis in uranium leach iron(III) chloride solutions by inductively coupled argon plasma spectrometry

    International Nuclear Information System (INIS)

    Inductively coupled Argon Plasma Spectrometry is used for the indirect determination of sulphate in iron(III) chloride leach solution of Elliot Lake uranium ores via addition of a known amount of barium ions and analyzing for excess of barium. The ore contains ∼ 7 wt% pyrite, FeS2, as the major mineral which oxidizes to generate sulphate during leaching with Fe(III). The effects of pH, the concentrations of Fe(III) and chloride ions and for presence of ethanol in the test samples on the accuracy of analysis are studied. It is found that unlike the Rhodizonate method, removal of iron(III) from or addition of ethanol to the test sample prior to analysis are not required. Linear calibration curves are obtained. (author)

  19. Statics of uranium adsorption from chloride-fluoride solutions by aminocarboxylic polyampholytes

    Energy Technology Data Exchange (ETDEWEB)

    Pakholkov, V.S.; Denisova, L.A.; Rychkov, V.N.

    1988-03-01

    The adsorption of uranium from UO/sub 2/Cl/sub 2/ solutions containing HCl, NH/sub 4/Cl, and HF using polyampholytes ANCB-1, ANCB-7, and ANCB-10, which were synthesized from the corresponding anion-exchange resins AN-31, AV-16D, and AN-61, has been investigated under static conditions. For pure chloride solutions, in a moderate HCl (or NH/sub 4/Cl) concentration range, adsorption occurs via a cation exchange mechanism. Anionic exchange is the main adsorption process for chloride-fluoride solutions containing HCl concentrations up to 2 M. These conclusions have been verified by IR spectroscopic data. The experimental results obtained for mixed chloride-fluoride solutions can be approximated using the following regression equations: (A/sub (0-3)/ = -0.83 + 0.13C/sub HF/ + 0.18C/sub HCl/ + 40.7C/sub U/ + 0.22C/sub HF/ x C/sub HCl/ - 10C/sub HCl/ x C/sub U/ + 30C/sub HF/ x C/sub U/ - 20C/sub HF/ x C/sub HCl/ x C/sub U/ (for the concentration range of HCl from 0 to 3.0 M); and A/sub (3-6)/ = -0.81 + 0.135C/sub HCl/ + 22C/sub U/ (for the HCl concentration range from 3.0 to 6.0 M). The variable A in these equations stands for the adsorptivity in mmole U/g.

  20. 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.

  1. 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.

  2. 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

  3. Extraction of scandium from chloride solutions using phenolformaldehyde resol oligomer Yarrezin B

    International Nuclear Information System (INIS)

    Scandium extraction from acid chloride solutions using phenolformaldehyde resol oligomer Yarrezin B (YRB) was studied by the methods of UV, IR and X-ray photoelectron spectroscopy. In YRB molecules phenol nuclei are bound by methylene, o,o-dimethyleneamine and o,o-dimethyleneether bridges. It was ascertained that under the conditions scandium is extracted by chelate mechanism at metal/reagent ratio 1 : 1, besides, two chlorine atoms and two water molecules are incorporated into the complex. Coordination bond scandium-nitrogen in aminogroup is observed in the complex

  4. Fluxional behavior of a cadmium zwitterion complex: proton transport and tautomerism in methylene chloride solution.

    Science.gov (United States)

    Anderson, Oren P; la Cour, Agnete; Berg, Andrew; Garrett, Andrew D; Wicholas, Mark

    2003-07-28

    The synthesis and structure of the tautomeric Cd(II) isoindoline zwitterion coordination compound [Cd(4'-MeLH)(NO(3))(2)].CH(3)OH (4'-MeLH = 1,3-bis[2-(4-methylpyridyl)imino]isoindoline) are reported. In methylene chloride solution, tautomer interconversion occurs as the N-H proton moves between the identical imine nitrogen atoms. We report the kinetics of proton transfer as followed by variable temperature (1)H NMR spectroscopy and demonstrate that methanol of solvation and adventitious water facilitate rapid proton transfer. PMID:12870937

  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. 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...

  7. Low temperature fatigue behavior of Alloy 600 in sodium chloride solution

    International Nuclear Information System (INIS)

    Fatigue crack growth (FCG) rates of mill annealed Alloy 600 in NaCl 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 NaCl (0.6M, 0.1M, and 0.001M) solution at room temperature. Environmental enhancement effect on the FCG rate of Alloy 600 was not significant in NaCl solution. Variations of the load frequency (0.03Hz--3Hz) did not influence the FCG rates of Alloy 600 significantly in air and 0.1M NaCl solution. The FCG rates of Alloy 600 in air and 0.1M NaCl 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

  8. 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)

  9. 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

  10. Effect of thermal aging on corrosion resistance of C-22 alloy in chloride solutions

    International Nuclear Information System (INIS)

    Alloy 22 (N06022) belongs to the Ni-Cr-Mo family and it is highly resistant to localized corrosion. The anodic behavior of mill annealed (MA) and thermally aged (10 hours at 760 C degrees) Alloy 22 was studied in chloride solutions with different pH values at 90 C degrees. Thermal aging leads to a microstructure of full grain boundary precipitation of topologically closed packed (TCP) phases. Electrochemical tests included monitoring of open circuit potential, potentiodynamic polarization and electrochemical impedance spectroscopy. Assessment of general and localized (crevice) corrosion was performed. Re passivation potentials were obtained from cyclic potentiodynamic polarization tests. Results indicate that MA and TCP material show similar general corrosion rates and crevice corrosion resistance in the tested environments. MA and TCP specimens suffered general corrosion in an active state when tested in low pH chloride solutions. The grain structure of the alloy was revealed for MA material, while TCP material suffered a preferential attack at grain boundaries. (author)

  11. 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

  12. Anodic dissolution and corrosion of Cu30Ni alloys in chloride solutions

    International Nuclear Information System (INIS)

    Anodic and corrosion behaviour of Cu30Ni alloy in 3n. NaCl+0.01n. HCl solution is studied by radiometric method using 58Co gamma-isotopes (as an alien label for nickel) and 64Cu ones in combination with electrochemical measurements. It is ascertained that under stationary conditions both in the process of anodic dissolution and corrosion the alloy dissolves gradually. Partial anodic polarization dissolution curves of the alloy components are obtained. It is shown that kinetics of their dissolution differs from dissolution regularities of the corresponding pure metals. During the alloy corrosion in oxygen atmoshere the reverse precipitation of copper on the alloy surface is absent. The mentioned peculiarities in corrosion-electrochemical behaviour of the alloy in a concentrated chloride solution are explained by the presence of nickel on the surface of the dissolving alloy

  13. 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.

  14. Thorium(IV) and radium(II) recovery from chloride solutions

    International Nuclear Information System (INIS)

    The studies on thorium(IV) and radium(II) removal by precipitation from process solutions of chloride processing of perovskite are reported. The solution acidity, reagent consumption, and temperature are studied for their effect on radium(II) coprecipitation with barium sulfate. It is found that radium(II) most completely precipitates at pH≥7. Under optimum purification conditions the level of α- and β-radioactivity goes down from ∼10000 to less than 75 Bq l-1. An optional technology is proposed which includes precipitation of hydroxides of iron(III), titanium(IV) or other elements at pH∼2.5, recovery of radium(II) on barium sulfate with simultaneous thorium(IV) precipitation (pH∼7), and preparation of rare earth(III) concentrate (pH∼9)

  15. Speciation of Tc(IV) in chloride solutions by capillary electrophoresis

    International Nuclear Information System (INIS)

    A method for speciation of Tc(IV) species (TcCl62- and TcCl5(H2O)-) in chloride solutions, using capillary electrophoresis (CE) technique was developed. The proposed method has overcome the difficulties of unstable oxidation states analysis by shortening their travel time in the capillary. TcCl62- and TcCl5(H2O)- were thus separated without being hydrolyzed and polymerized, and their UV/Vis spectra were recorded. With a 1 M HCl/NaCl buffer solution (pH = 1), the electrophoretic mobilities were determined as 5.47 x 10-4 cm2/Vs for TcCl62- and 2.13 x 10-4 cm2/Vs for TcCl5(H2O)- at 25 C. The total analysis time for one run is 12 minutes. (orig.)

  16. Corrosion performance of SiCsubp/6061 Al metal matrix composites in sodium chloride solution

    International Nuclear Information System (INIS)

    The corrosion performance of silicon carbide particle/aluminium metal matrix composites (SiCsubp/Al) were studied in sodium chloride solution by means of electrochemical, microscopic, gravimetric and analytical techniques. The materials under investigation were compocasting processed 6061 Al reinforced with increasing amounts of SiC particles. Potentiostatic polarization tests were done in 0.1M NaCl solutions that were aerated or deaerated to observe overall corrosion behaviour. It was seen that the corrosion potentials did not vary greatly in relation to the amounts of SiCsubp reinforcement. Corrosion tests showed that the degree of corrosion increased with increasing SiCsubp content. SEM analysis technique was used to study the corroded samples and the pitting morphology. By TEM, no intermetallic layer was found at SiC/Al interface. A model for pitting process was proposed

  17. Conductivity and Viscosity Measurements for Binary Lysozyme Chloride Aqueous Solution and Ternary Lysozyme-Salt-Water Solution

    CERN Document Server

    Buzatu, D; Buzatu, F D

    2004-01-01

    We use the conductimetric method, adequate to electrolytes, to determine the lysozyme charge in lys-water and ternary lys-salt-water systems. We measured also the viscosities for the above binary and ternary systems in the same conditions at pH$=4.5$ and T$=298$ K, measurements that allow us to see any effect of viscosity on cations mobilities and implicitly on the lysozyme charge. The method is illustrated for the lysozyme chloride aqueous solution system at 25$^o$ C, using the data reported here for pH$=4.5$ at 0.15, 0.6, 0.8, 1., 1.5, 2., 2.5, 3., 3.5 mM (mg/mL) lysozyme chloride concentrations. The method was also applied to ternary lys-salt-water systems in the same conditions at pH$=4.5$ and T$=25^o$ C. Ternary conductivities are reported for a mean concentration 0.6 mM of lysozyme chloride in all systems and a mean concentration 0.01, 0.025, 0.05, 0.1, 0.175, 0.2, 0.5, 0.7, 0.9, 1.2, 1.3 and 1.4 M for NaCl; 0.005, 0.01, 0.05, 0.1, 0.175, 0.2, 0.5, 0.7, 0.9, 1.2, 1.3, 1.4 and 1.5 M for KCl; 0.005, 0.01,...

  18. Separation of platinum and rhodium from chloride solutions containing aluminum, magnesium and iron using solvent extraction and precipitation methods.

    Science.gov (United States)

    Raju, B; Kumar, J Rajesh; Lee, Jin-Young; Kwonc, Hyuk-Sung; Kantam, M Lakshmi; Reddy, B Ramachandra

    2012-08-15

    The solvent extraction and precipitation methods have been used to develop a process to separate platinum and rhodium from a synthetic chloride solutions containing other associated metals such as (mg/L): Pt-364, Rh-62, Al-13880, Mg-6980, Fe-1308 at chloride ([Pt(tu)(4)]Cl(2)). The selective precipitation of rhodium was performed with (NH(4))(2)S from platinum free raffinate with a recovery of >99%. PMID:22664260

  19. 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.

  20. Alcohol solutions of triphenyl-tetrazolium chloride as high-dose radiochromic dosimeters

    International Nuclear Information System (INIS)

    The radiolytic reduction of colorless tetrazolium salts in aqueous solution to the highly colored formazan dye is a well-known acid-forming radiation chemical reaction. Radiochromic thin films and three-dimensional hydrocolloid gels have been used for imaging and mapping absorbed dose distributions. The high solubility of 2,3,5-triphenyl-tetrazolium chloride (TTC) in alcohols provides a useful liquid dosimeter (45 nM TTC in aerated ethanol) and shows a linear response of absorbance increase (λmax = 480 nm) with dose over the range 1-16 kGy. The linear molar absorption coefficient (εm) for the formazan at the absorption peak is 1.5 x 103 m2 mol-1, and the radiation chemical yield for the above solution is G (formazan) = 0.014 μmol J-1. The irradiation temperature coefficient is about 0.8 percent per degree Celsius rise in temperature over the temperature range 0-30oC but is much larger between 30oC and 60oC. The unirradiated and irradiated solutions are stable over at least five days storage at normal laboratory temperature in the dark, but when stored in daylight at elevated temperature, the unirradiated solution in sealed amber glass ampoules undergoes slow photolytic dye formation, and the irradiated solution experiences initial fading and subsequent reversal (photochromism) when exposed to direct sunlight. (author)

  1. 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.

  2. 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.

  3. 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

  4. 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

  5. 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

  6. 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

  7. Sorption of uranium(VI) ions from hydrochloric acid and ammonium chloride solutions by anion exchangers

    International Nuclear Information System (INIS)

    The sorption of macroscopic quantities of uranium from solutions of UO2Cl2 containing HCl and NH4Cl in concentrations from 0.0 to 6.0 M by the AV-17 x 8, AV-16G, EDE-10P, AN-31, AN-2F, AN22, and AN-251 anion exchangers has been investigated under static conditions. The sorption isotherms are described by an equation similar to Freundlich's equation: K/sub d/ = K tilde x C/sub eq/sup 1/z/ or log K/sub d/ = log K tilde + 1/z x log C/sub eq/. Equations describing the dependence of the sorbability (or K/sub d/) on the equilibrium concentration of uranium in the solution have been obtained with the aid of the least-squares method. Conclusions regarding the chemistry of the exchange of uranium ions on anion exchangers in chloride solutions have been drawn on the basis of the UV spectra of the original solutions and the IR spectra of the ion exchangers obtained in this work, as well as the established general laws governing sorption

  8. Sorption of uranium(VI) ions from hydrochloric acid and ammonium chloride solutions by anion exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Pakholkov, V.S.; Denisova, L.A.; Rychkov, V.N.; Kurnosenko, N.A.

    1988-01-01

    The sorption of macroscopic quantities of uranium from solutions of UO/sub 2/Cl/sub 2/ containing HCl and NH/sub 4/Cl in concentrations from 0.0 to 6.0 M by the AV-17 x 8, AV-16G, EDE-10P, AN-31, AN-2F, AN22, and AN-251 anion exchangers has been investigated under static conditions. The sorption isotherms are described by an equation similar to Freundlich's equation: K/sub d/ = K tilde x C/sub eq/sup 1/z/ or log K/sub d/ = log K tilde + 1/z x log C/sub eq/. Equations describing the dependence of the sorbability (or K/sub d/) on the equilibrium concentration of uranium in the solution have been obtained with the aid of the least-squares method. Conclusions regarding the chemistry of the exchange of uranium ions on anion exchangers in chloride solutions have been drawn on the basis of the UV spectra of the original solutions and the IR spectra of the ion exchangers obtained in this work, as well as the established general laws governing sorption.

  9. 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.

  10. Repassivation potentials determination of crevice corrosion of alloy in Chloride solutions

    International Nuclear Information System (INIS)

    Alloy 22 (UNS N06022) belongs to the Ni-Cr-Mo family and it is highly resistant to general and localized corrosion, but it may suffer crevice corrosion in aggressive environmental conditions, such as high chloride concentration, high applied potential and high temperature. Alloy 22 is one of the candidates to be considered for the outer corrosion-resistant shell of high-level nuclear waste containers. It is assumed that localized corrosion will only occur when the corrosion potential (ECORR) is equal or higher than the crevice corrosion repassivation potential (ER,CREV). This parameter is obtained by different electrochemical techniques using artificially creviced specimens. These techniques include cyclic potentiodynamic polarization (CPP) curves, Tsujikawa-Hisamatsu electrochemical (THE) method or other non-standardized methods. Recently, as a variation of THE method, the PD-GS-PD technique was introduced. The aim of the present work was to determine reliable critical potentials for crevice corrosion of Alloy 22 in pure chloride solutions at 90 C degrees. Conservative methodologies (which include extended potentiostatic steps) were applied for determining protection potentials below which crevice corrosion cannot initiate and propagate. Results from PD-GS-PD technique were compared with those from these methodologies in order to assess their reliability. Results from the CPP and the THE methods were also considered for comparison. The repassivation potentials from the PD-GS-PD technique were conservative and reproducible, and they did not depend on the amount of previous crevice corrosion propagation in the studied conditions. (author)

  11. 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.

  12. 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.

  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. 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.

  15. 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.

  16. Equilibrium studies of cobalt(II) extraction with 2-pyridineketoxime from mixed sulphate/chloride solution

    International Nuclear Information System (INIS)

    In present paper the equilibrium of cobalt extraction with 1-(2-pyridyl)tridecan-1-one oxime from the chloride/sulphate solutions was studied. The presented results indicated that extraction depends on a number of process variables, including the pH, metal and Cl- concentration in the aqueous feed, and concentration of the oxime in the organic phase. The created cobalt-complexes with the 2-pyridine ketoxime were stable and only concentrated HCl was found to be a suitable stripping agent for coordinated metal. The separation of Co(II) from Zn(II), Ni(II) and Cu(II) was also studied, but the selective recovery of the metals was possible using the multi-stage stripping process. (author)

  17. Radiochemical extraction of mercury(II) from acidic chloride solutions using dialkylsulphides

    International Nuclear Information System (INIS)

    The liquid-liquid extraction behavior of Hg(II) from aqueous acidic chloride solutions has been investigated by tracer techniques using dialkylsulphides (R2S) namely, dibutylsulphide (DBS) and dioctylsulphide (DOS) as extractants. These extraction data have been analyzed by both graphical and theoretical methods by taking into account complexation of the metal ion in the aqueous phase with inorganic ligands and all plausible complexes extracted into the organic phase. The results clearly indicate that Hg(II) is extracted into xylene as HgCl2 x nDBS/nDOS (where n = 2 and 3). The equilibrium constants of the extracted complexes have been deduced by non-linear regression analysis. The separation possibilities of Hg(II) from other metal ions viz. Ca(II), Mg(II), Ba(II) and Fe(III), which are present in the industrial wastes of the chlor-alkali industry has also been discussed. (author)

  18. Pitting and crevice corrosion behaviour of high alloy stainless steels in chloride-fluoride solutions

    International Nuclear Information System (INIS)

    The localised corrosion resistance (pitting and crevice corrosion) of two high alloy stainless steels, namely superduplex (SD) and superaustenitic (SA), has been studied in chloride-fluoride solutions at pH values ranging from 2 to 6.5. The pitting potential (Epit) and crevice potential (Ecre) have been calculated for these test media using electrochemical techniques (continuous current). The critical pitting temperature (CPT) and critical crevice temperature (CCT) are in both materials lower then the room temperature. In spite of this fact and due to the high repassivation rate, the resistance of these materials to localised corrosion is high in the tested media. At the highest tested concentration of aggressive anions and pH 6.5 both materials undergo a generalised attack. (orig.)

  19. 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.)

  20. 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.

  1. 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.

  2. Determination of cadmium, cobalt, manganese, copper, nickel, and chromium in concentrated solutions of calcium chloride by electrothermal atomic absorption spectrometry

    International Nuclear Information System (INIS)

    A procedure is developed for the direct determination of Cd, Co, Cr, Cu, Mn, and Ni in concentrated solutions of calcium chloride by electrothermal atomic absorption spectrometry. Ascorbic and oxalic acids and magnesium nitrate were examined as chemical modifiers. Oxalic acid was found to be the best modifier. Although an atomic absorption spectrometer with a background correction system of relatively low efficiency (deuterium lamp) was used, elements under study can be reliably determined in the presence of oxalic acid at concentrations of calcium chloride in the solution up to 6%. Because cadmium is evaporated before the major part of the given matrix, it can be determined without modifier

  3. Sodium carboxymethylcellulose-induced aggregation of 1-decyl-3-methylimidazolium chloride in aqueous solutions.

    Science.gov (United States)

    Ray, Dhiman; Das, Sourav; De, Ranjit; Das, Bijan

    2015-07-10

    Aggregation behavior of a surface active ionic liquid 1-decyl-3-methylimidazolium chloride (C10MeImCl) was studied in aqueous solutions in absence and in presence of sodium carboxymethylcellulose (NaCMC) by electrical conductivity, surface tension, vapor pressure, and fluorescence measurements. Ion-association behavior of C10MeImCl (aq) in the premicellar regime has also been investigated. Two characteristic concentrations, namely the critical aggregation concentration and polymer saturation concentration, before free C10MeImCl micelles appear in C10MeImCl-NaCMC solutions were identified. Effects of temperature, NaCMC concentration, and the bulk solution structural property on the self-aggregation of C10MeImCl have been discussed to elucidate C10MeImCl-NaCMC interactions. Thermodynamics of the micellization processes provided important insight regarding the (a) release of water molecules from the hydration layer around the hydrophilic domain, and from the water cage around the hydrophobic moiety of the SAIL, and (b) transfer of the hydrocarbon chains into the micelle and restoration of the H-bonding structure of the water around the micelle. PMID:25857982

  4. 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.

  5. The vapour pressures over saturated aqueous solutions of cadmium chloride, cadmium bromide, cadmium iodide, cadmium nitrate, and cadmium sulphate

    Energy Technology Data Exchange (ETDEWEB)

    Apelblat, Alexander [Department of Chemical Engineering, Ben Gurion University of the Negev, P.O. Box 653, Beer Sheva 84105 (Israel)]. E-mail: apelblat@bgu.ac.il; Korin, Eli [Department of Chemical Engineering, Ben Gurion University of the Negev, P.O. Box 653, Beer Sheva 84105 (Israel)

    2007-07-15

    Vapour pressures of water over saturated solutions of cadmium salts (chloride, bromide, iodide, nitrate, and sulphate) were determined over the temperature range 280 K to 322 K and compared with the literature data. The vapour pressures determined were used to obtain the water activities, osmotic coefficients and the molar enthalpies of vaporization in the (cadmium salt + water) systems.

  6. The vapour pressures over saturated aqueous solutions of cadmium chloride, cadmium bromide, cadmium iodide, cadmium nitrate, and cadmium sulphate

    International Nuclear Information System (INIS)

    Vapour pressures of water over saturated solutions of cadmium salts (chloride, bromide, iodide, nitrate, and sulphate) were determined over the temperature range 280 K to 322 K and compared with the literature data. The vapour pressures determined were used to obtain the water activities, osmotic coefficients and the molar enthalpies of vaporization in the (cadmium salt + water) systems

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

    OpenAIRE

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

    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 ...

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

    International Nuclear Information System (INIS)

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

  9. Evaluation and countermeasure of localized corrosion of stainless steels in neutral chloride solution environment

    International Nuclear Information System (INIS)

    It consists of the experimental conditions, the critical potential of crevice corrosion, in-situ measurement of the initiation behavior by Moire method, spontaneous potential (ESP) in the environment, addition of no effective anions for countermeasure of localized corrosion, and conclusions. The stainless steel type 304, 825, 625 and Ti are used as the samples and evaluated by the repassivation potential (ER,CREV) under some experimental conditions. The relation between ER,CREV and VCREV of type 444 in NaCl solution at 80 deg C showed two values were same. The growth behavior was affected largely by the potential values, concentration of NaCl, elements of alloys. Initiation and repassivation of crevice corrosion were controlled by addition of NO-3 and SO2-4. Relation between NM and ΔER,CREV/ΔT, some experimental conditions, profile of initiation-growth behavior of crevice corrosion of 18%Cr-14%Ni stainless steel, effects of alloy elements; P, Mn, Si and Cu on dissolution rate and ER,CREV of 18%Cr-14%Ni stainless steels, relation between ESP and O3 or residual chloride in seawater etc are illustrated. (S.Y.)

  10. 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.

  11. 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.

  12. 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.

  13. 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)

  14. 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

  15. Actitudes y comportamiento social

    OpenAIRE

    Fernández García, Rubén

    2014-01-01

    Treball Final de Grau en Criminologia i Seguretat. Codi: CS1044. Curs 2013-2014 La influencia en el conocimiento de las actitudes sobre el comportamiento es ampliamente conocida. Antiguamente, los psicólogos sociales afirmaban que se podría vaticinar un futuro comportamiento si existía un conocimiento amplio de las actitudes del individuo, pero esta tesis ha quedado desvirtuada al no tratarse de un aspecto invariable, es decir, las personas ante actitudes similares pueden actua...

  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. Calcium chloride and calcium bromide aqueous solutions of technical and analytical grade in Lemna bioassay.

    Science.gov (United States)

    Vujević, M; Vidaković-Cifrek, Z; Tkalec, M; Tomíc, M; Regula, I

    2000-11-01

    Saturated water solutions of calcium chloride, calcium bromide and their 1:1 mixture are commonly used as "high density brines" for pressure control in oil wells. To compare the effect of these chemicals of technical grade with the effect of the chemicals of analytical grade the Lemna test was used. The multiplication rate, fresh weight, dry to fresh weight ratio, area covered by plants and chlorophyll content were measured as toxicity parameters. The concentrations of tested chemicals were 0.025, 0.05. 0.075 and 0.1 mol dm(-3). Generally, the chemicals of both technical and analytical grade in concentrations of 0.025 mol dm(-3) stimulated the Lemna minor growth, while tested chemicals in concentrations of 0.05 mol dm(-3) did not affect the growth significantly. The exceptions were results obtained by measuring fresh weight. Most of tested chemicals in concentrations of 0.075 mol dm(-3) and all chemicals in concentrations of 0.1 mol dm(-3) reduced the growth. No major differences between effects of tested chemicals of technical and analytical grade on plant growth were observed, except that tested chemicals of analytical grade in concentrations of 0.1 mol dm(-3) increased dry to fresh weight ratio much stronger than chemicals of technical grade. All tested chemicals in all concentrations increased chlorophyll content. After treatment with chemicals of analytical grade much higher increase of chlorophyll a concentration in comparison to increase of chlorophyll b was noticed, while chemicals of technical grade caused more prominent increase of chlorophyll b. PMID:11057678

  18. On the Stress Corrosion Cracking and Hydrogen Embrittlement Behavior of Austenitic Stainless Steels in Boiling Saturated Magnesium Chloride Solutions

    OpenAIRE

    Alyousif, Osama M.; Rokuro Nishimura

    2012-01-01

    The stress corrosion cracking (SCC) and hydrogen embrittlement (HE) behaviors for types 304, 310, and 316 austenitic stainless steels were investigated in boiling saturated magnesium chloride solutions using a constant load method under different conditions including test temperature, applied stress, and sensitization. Both of type 304 and type 316 stainless steels showed quite similar behavior characteristics, whereas type 310 stainless steel showed a different behavior. The time to failure ...

  19. 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.)

  20. 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...

  1. Stress corrosion cracking of nickel alloys in bicarbonate and chloride solutions

    International Nuclear Information System (INIS)

    Alloy 22 is one of the candidates for the manufacture of high level radioactive waste containers. These containers provide services in natural environments characterized by multi-ionics solutions, it is estimated they could suffer three types of deterioration: general corrosion, localized corrosion (crevice corrosion) and stress corrosion cracking (SCC). It has been confirmed that the presence of bicarbonate at temperatures above 60°C and applied potentials around +400 mVSCE are necessary in order to produce cracking, . This susceptibility may be associated to the instability of the passive film formed and to the formation of an anodic current peak in the polarization curves in these media. Until now, it is unclear the role played by each alloying element (Ni, Cr or Mo) in the SCC susceptibility of Alloy 22 in these media The aim of this work is to evaluate the SCC susceptibility of nickel-based alloys in media containing bicarbonate and chloride ions, at high temperature. Slow Strain Rate Testing (SSRT) was conducted to samples of different alloys: 22 (Ni-Cr-Mo), 600 (Ni-Cr-Fe), 800H (Ni-Fe-Cr) y 201 (99.5% Ni).This tests were conducted in 1.1 mol/L NaHCO3 +1.5 mol/L NaCl a 90°C and different applied potentials (+200mVSCE,+300 mVSCE, +400 mVSCE). These results were complemented with those obtained in a previous work, where we studied the anodic electrochemical behavior of nickel base alloys under the same conditions. It was found that alloy 22 showed a current peak in a potential range between +200 mVSCE and +300 mVSCE when immersed in bicarbonate ions containing solutions. This peak was attributed to the presence of chromium in the alloys. The SSRT showed that only alloy 22 has a clear indication of stress corrosion cracking. The current results suggested that the presence of an anodic peak in the polarization curves was not a sufficient condition for cracking. (author)

  2. Chemical behaviour of Np, Pu and Am in saline solutions: Radiolysis, solubility, hydrolysis, chloride complexation and speciation

    International Nuclear Information System (INIS)

    The assessment of the migration behaviour of actinide elements (Np, Pu, Am) in the geosphere requires detailed knowledge on basic geochemical reactions, which include not only primary reactions of actinides with groundwater components but also secondary reactions, such as radiolysis, redox reaction, colloid formation, etc. The radiolytic behaviour of Pu and Am has been investigated in solutions of high NaCl concentration, in which radiolysis reactions are induced by intensive α-radiations of actinides themselves. An increase in the redox potential (Eh) is observed in solutions, which results in the quantitative oxidation of Pu(IV) into Pu(VI) and Am(III) into Am(V). These reactions are dependent on pH, salinity and specific α-activity. The results of α-radiolysis are compared with the effect of γ-radiolysis on inactive chloride solutions. As Pu(VI) can be stabilized in concentrated NaCl solutions, indicating that chloride complexation of Pu(VI) is important, the chloride complexation is studied by spectrophotometry and the stability constants of the first two Pu(VI)-chloro complexes are determined. Solubility experiments of NpO2 and NpO2OH in concentrated saline solutions are carried out under aerobic and anaerobic atmosphere (90% Ar, 1% CO2). The speciation of soluble species is undertaken by UV-VIS-spectrophotometry. The experiment of the Am(III)-hydrolysis reaction has revealed a dependence of Am solubility on the specific α-activity. However, no alteration in the chemical state of hydrolysis products is observed in different specific α-activities. The speciation is carried out by laser induced photoacoustic spectroscopy (LPAS) because of the low Am(III) solubility at pH>7. (orig./RB)

  3. Model investigations for trace analysis of iodine, uranium, and technetium in saturated sodium chloride leaching solutions of stored radioactive waste

    International Nuclear Information System (INIS)

    This paper describes the development of a time and cost saving chromatographic technique, which allows the matrix to be separated and the most important species to be analyzed in a leaching solution of vitrified radioactive waste. Uranium, iodine, and technetium were chosen for the model technique to be elaborated. In a first step, iodide and pertechnetate were separated from the matrix by the strongly basic AG 1X 8 anion exchange resin and then separated from each other by selective elution. The uranyl ions eluted with the sodium chloride matrix were separated from the excess of sodium chloride in a second step, again by adsorption to the strongly basic resin. The ion-selective electrode was found to be a suitable tool for iodide analysis. Pertechnetate was analysed by means of liquid scintillation. Uranium was determined by ICP-AES. (orig./RB)

  4. 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...

  5. Comportamiento sexual y ansiedad

    Directory of Open Access Journals (Sweden)

    Nadia Romina Justel

    2009-01-01

    Full Text Available En el presente trabajo se revisarán las investigaciones con animales no humanos que atañen a la relación existente entre comportamiento sexual y ansiedad. Por una parte, los resultados más relevantes indican que el comportamiento sexual posee un efecto de tipo ansiolítico o atenuante del estrés, que se manifiesta tanto en la conducta de los sujetos como a niveles fisiológicos o neuroendocrinos. Por otra parte, hay estudios que hacen referencia a la relación de signo contrario, es decir, cómo el estrés afecta el comportamiento sexual de los animales.

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. Development of a combined solution formulation of atropine sulfate and obidoxime chloride for autoinjector and evaluation of its stability.

    Science.gov (United States)

    Ettehadi, Hossein Ali; Ghalandari, Rouhollah; Shafaati, Alireza; Foroutan, Seyed Mohsen

    2013-01-01

    Atropine (AT) and oximes, alone or in combination, have been proven greatly valuable therapeutics in the treatment of organophosphates intoxications. An injectable mixture of AT and obidoxime (OB) was formulated for the administration by automatic self-injector. The aqueous single dose solution contained 275 mg obidoxime chloride and 2.5 mg atropine sulfate per 1 mL (220 mg and 2 mg per 0.8 effective dose, respectively). The final solution was sterilized by filtration through a 0.22 μm pore size filter. This more concentrated solution allowed to use a smaller size and lighter weight cartridge. Quality control tests, including assay of the two major compounds were performed separately, using reversed-phase HPLC methods. Besides, the stability test was carried out according to ICH guideline for the accelerated test. The obtained results showed that the proposed formulation is stable over a period of 2 years after preparation. PMID:24250669

  11. 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.

  12. 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.

  13. 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.

  14. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yafei; Cheng, Guangxu, E-mail: gxcheng@mail.xjtu.edu.cn; Wu, Wei; Qiao, Qiao; Li, Yun; Li, Xiufeng

    2015-09-15

    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.

  16. 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

  17. Effect of pore water velocities and solute input methods on chloride transport in the undisturbed soil columns of Loess Plateau

    Science.gov (United States)

    Zhou, BeiBei; Wang, QuanJiu

    2016-04-01

    Studies on solute transport under different pore water velocity and solute input methods in undisturbed soil could play instructive roles for crop production. Based on the experiments in the laboratory, the effect of solute input methods with small pulse input and large pulse input, as well as four pore water velocities, on chloride transport in the undisturbed soil columns obtained from the Loess Plateau under controlled condition was studied. Chloride breakthrough curves (BTCs) were generated using the miscible displacement method under water-saturated, steady flow conditions. Using the 0.15 mol L-1 CaCl2 solution as a tracer, a small pulse (0.1 pore volumes) was first induced, and then, after all the solution was wash off, a large pulse (0.5 pore volumes) was conducted. The convection-dispersion equation (CDE) and the two-region model (T-R) were used to describe the BTCs, and their prediction accuracies and fitted parameters were compared as well. All the BTCs obtained for the different input methods and the four pore water velocities were all smooth. However, the shapes of the BTCs varied greatly; small pulse inputs resulted in more rapid attainment of peak values that appeared earlier with increases in pore water velocity, whereas large pulse inputs resulted in an opposite trend. Both models could fit the experimental data well, but the prediction accuracy of the T-R was better. The values of the dispersivity, λ, calculated from the dispersion coefficient obtained from the CDE were about one order of magnitude larger than those calculated from the dispersion coefficient given by the T-R, but the calculated Peclet number, Pe, was lower. The mobile-immobile partition coefficient, β, decreased, while the mass exchange coefficient increased with increases in pore water velocity.

  18. 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.

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

    International Nuclear Information System (INIS)

    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 Rct 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

  20. 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)

  1. 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. ...

  2. 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.

  3. Studies on the separation of Ir(IV) and Ru(III) from chloride solutions using supported liquid membrane technique

    International Nuclear Information System (INIS)

    Due to limited resources, the gap between supply and demand of the platinum group metals (Rh, Ru, Ir, Pt, Pd) is increasing. Recycling after their use is an important resource in seeking to meet growing demand for these metals. Supported liquid membrane (SLM) technique is one of the promising techniques for the separation and recovery of species from their very dilute solutions where under similar conditions other conventional techniques are not economical. In the present work the transfer of ruthenium(III) from chloride solutions across supported liquid membrane and its separation from iridium(IV) was studied. Cyanex 923 (C923) and Alamine 336 (A336) as ion carriers were applied. Based on the results obtained in solvent extraction experiments it is expected that the presence of the Ru in the source phase will not affect on the transport of Ir(IV). Moreover, when both metals were present in the mixture the extraction of Ru decreased

  4. 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.

  5. Aggregation and adsorption behavior of cetylpyridinium chloride in aqueous sodium salicylate and sodium benzoate solutions.

    Science.gov (United States)

    Mukhim, T; Dey, J; Das, S; Ismail, K

    2010-10-15

    The critical micelle concentration (cmc) values of cetylpyridinium chloride (CPC) were determined in the presence of salicylate and benzoate ions in the less explored concentration region where viscosity is Newtonian. The cmc of CPC decreased from 9 x 10(-4) to 7 x 10(-7) and 3 x 10(-6) mol kg(-1) by adding about 0.3 mol kg(-1) of salicylate and benzoate, respectively. The ortho hydroxyl group in salicylate thus has a remarkable influence on the micellization of CPC and the extent of this favorable effect is found to be about 3.5 kJ mol(-1). The Corrin-Harkins equation was modified to explain the variation of cmc with electrolyte concentration in the presence of mixed counterions. The slope of the equation does not provide the value of the total counterion binding constant (beta), but gives us information about the lower limit to the value of beta, which is found to be 0.66. Addition of salicylate and benzoate increases the counterion binding to CPC micelles compared to that in the presence of chloride alone. An adsorption isotherm was derived to estimate the surface excess of CPC in the presence of mixed counterions. PMID:20673910

  6. 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.

  7. 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.

  8. 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

  9. Material Solutions to Mitigate the Alkali Chloride-Induced High Temperature Corrosion

    DEFF Research Database (Denmark)

    Kiamehr, Saeed

    High temperature corrosion induced by potassium chloride (KCl) is a major challenge for biomass-based power plants. The current study aims at identification or development of alloys or coatings that can yield a better performance at a target metal temperature of 600oC compared to austenitic...... of metals. This was aimed at identifying the constituent elements of a corrosion resistant alloy. Calculations suggested Al, Si, Cr, Ti, Y, Ce, Ta, Hf and Zr as suitable oxide-forming elements as well as Mo, Ni and Co as suitable matrix-forming elements. However, the presence of potassium in the...... available alloys and obtain further knowledge on the mechanism of high temperature corrosion induced by KCl, a wide range of commercial and model alloys were exposed under conditions relevant to high temperature corrosion in biomass-firing power plants. The exposures were conducted at 600oC for 168h in...

  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. Attenuation coefficients of 123 keV γ-radiation by dilute solutions of sodium chloride

    International Nuclear Information System (INIS)

    The linear attenuation and mass attenuation (or absorption) coefficients of the 123 keV γ radiation from 57Co by dilute solutions of NaCl were studied for varying concentrations. The mixture rule for the theoretical calculation of attenuation coefficients was developed for solutions. This study explores the validity of the expected exponential attenuation absorption law for γ-radiation in solutions and also provides an alternative method for the direct determination of linear and mass attenuation coefficients of soluble salts in solid form without obtaining them in pure crystalline form. (Author)

  13. 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.

  14. Uranium, thorium and rare earth extraction and separation process by processing their chloride aqueous solutions

    International Nuclear Information System (INIS)

    The different steps of the process are the following: uranium and iron extraction by a neutral organic phosphorus compound and thorium and rare earth recovery in an aqueous solution, iron recovery in acid aqueous phase, concentration of the thorium and rare earth aqueous solution followed by thorium extraction with a organic phosphorus compound and rare earth recovery in the aqueous phase, thorium recovery in acid aqueous phase

  15. 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)

  16. Effects of hydrogen and surface dislocation on active dissolution of deformed 304 austenitic stainless steel in acid chloride solution

    International Nuclear Information System (INIS)

    Research highlights: → An active dissolution model was proposed by the stored strain energy and electron work function. → An significant effect of plastic deformation on active dissolution was observed. → The synergistic effect between the dissolved hydrogen and applied stress is negligible. → The change of surface morphology due to dislocation made the electron more active. - Abstract: The mechanochemical effects between dissolved hydrogen and deformation on active dissolution of 304 stainless steel in acid chloride solution were investigated by use of constant loading test method. A theoretical model was proposed in terms of the stored strain energy and electron work function. Results indicated that active dissolution was affected mainly by Gibbs free energy produced by the part of plastic deformation and surface dislocation structure. A good agreement between the prediction and test results revealed that the synergistic effect of stress and dissolved hydrogen only promoted the process of active dissolution.

  17. A conductivity study of unsymmetrical 2:1 type "complex ion" electrolyte: cadmium chloride in dilute aqueous solutions.

    Science.gov (United States)

    Apelblat, Alexander; Esteso, Miguel A; Bešter-Rogač, Marija

    2013-05-01

    Systematic and precise measurements of electrical conductivities of aqueous solutions of cadmium chloride were performed in the 2 × 10(-5)-1 × 10(-2) mol·dm(-3) concentration range, from 278.15 to 313.15 K. Determined conductances were interpreted in terms of molecular model which includes a mixture of two 1:1 and 2:1 electrolytes. The molar limiting conductances of λ(0)(CdCl(+), T) and λ(0)(1/2Cd(2+), T), the equilibrium constants of CdCl(+) formation K(T) and the corresponding standard thermodynamic functions were evaluated using the Quint-Viallard conductivity equations, the Debye-Hückel equations for activity coefficients and the mass-action equation. An excellent agreement between calculated and experimental conductivities was reached. PMID:23534843

  18. X-ray fluorescence determination of Au, Pd and Pt from chloride solutions after preconcentration on cellulose filters

    International Nuclear Information System (INIS)

    The aim of this work was synthesis of new sorption cellulose filters for dynamic preconcentration of Au, Pd and Pt from chloride solutions and subsequent XRF determination of these elements on the filters. New filters were prepared by impregnation of a filter paper with solution of tri-n-octylamine and paraffin in hexane (TOA-filters). The effect of paraffin and TOA concentration in hexane on a content of nitrogen in a filter was studied. It was found that Au(III), Pd(II) and Pt(IV) were quantitatively recovered on the TOA-filters (filtering surface diameter of 23 mm, thickness of 0.15 mm) from 0.5 - 1 M HCl at a flow rates of 2-5 ml min-1 from 10-100 ml of solution. The mathematical model of sorption dynamics was offered for the estimation of potential possibilities of new impregnated sorbents and for the evaluation of optimum dynamic conditions allowing to achieve of maximum concentration efficiency (CEmax). The elements were determined directly on the filters by XRF spectrometer. Palladium was also determined on the TOA-filters after formation of coloured compounds of metal with 4-(2-pyridylazo)resorcinol (PAR) by diffuse reflectance spectroscopy with the calculation of calorimetric characteristics and using test-scale. (authors)

  19. Effect of nitrogen on the corrosion behavior of austenitic stainless steel in chloride solutions

    International Nuclear Information System (INIS)

    The effect of partial replacement of nickel with nitrogen on the mechanism of localized corrosion resistance and re-passivation for nitrogen-bearing stainless steel was investigated using anodic potentiodynamic polarization technique. The solutions used for this study contained 0.0, 0.05 and 0.33 M Fe3+ for solutions I, II and III respectively, in a total Cl- ion concentration 1 M. The pitting attack was found to be retarded by nitrogen addition and the samples were able to passivate as the nitrogen increase. Addition of nitrogen allows decreasing the percentage of Ni, but to a certain limit. Nitrogen is adsorbed on the interface of the metal oxide and results in repulsion of Cl- ions. Moreover, it reacts with H+ ions in the solution leading to higher pH, which explains the retardation effect of nitrogen to corrosion. (author)

  20. The role of temperature in copper electrocrystallization in ammonia-chloride solutions

    International Nuclear Information System (INIS)

    This paper presents the analysis of temperature effect on the copper electrocrystallization process from the stainless steel/Cu(II)-Cu(I)-NH4Cl-NH3-H2O system. Electrochemical techniques and scanning electron microscopy with energy dispersion spectroscopy were employed. An increment in temperature had a favorable effect in increasing the kinetic and nucleation parameters, favoring the copper reduction on the stainless steel substrate. From the chronoamperometric study, it was possible to find the transfer coefficient (α), which does not have a significant variation with temperature, and the exchange current density (i ) for different temperatures, where a 50.63 kJ/mol value was estimated for the activation energy. The potentiostatic study suggested the presence of two processes involved: an electron transfer reaction and a 3D nucleation-growth process, under combined charge transfer and diffusion limitations. In addition, an important current contribution could be accounted for on the basis of the existence of a capacitive component in the system. This capacitive behavior was associated to the oxide layer (Cr2O3)-chloride interactions on the stainless steel surface. Current transients analyses at different potentials, based on the models of: Milchev (low overpotential), Scharifker-Mostany (SM) and Heermann-Tarallo (HT) (high overpotential) allowed to obtain the values of nucleation parameters, such as: the nucleation rate constant (A), the active nucleation sites number (N ), the stationary nucleation rate (I st = A x N ) and the nuclei saturation number (N s). Finally, the deposits obtained were analyzed by SEM, showing an acceptable correlation between the nucleation parameters and morphology of the deposits obtained. An increment in temperature favored the growth of the cluster before the coalescence occurred

  1. Evaluation of the cytotoxic effects of ophthalmic solutions containing benzalkonium chloride on corneal epithelium using an organotypic 3-D model

    Directory of Open Access Journals (Sweden)

    Jessen Bart A

    2009-07-01

    Full Text Available Abstract Background Benzalkonium chloride (BAC is a common preservative used in ophthalmic solutions. The aim of this study was to compare the cytotoxic effects of BAC-containing ophthalmic solutions with a BAC-free ophthalmic solution using an organotypic 3-dimensional (3-D corneal epithelial model and to determine the effects of latanoprost ophthalmic solution and its BAC-containing vehicle on corneal thickness in a monkey model. Methods The cytotoxicity of commercially available BAC-containing ophthalmic formulations of latanoprost (0.02% BAC and olopatadine (0.01% BAC was compared to that of BAC-free travoprost and saline in a corneal organotypic 3-D model using incubation times of 10 and 25 minutes. To compare the extent of differentiation of 3-D corneal cultures to monolayer transformed human corneal epithelial (HCE-T cell cultures, expression levels (mRNA and protein of the corneal markers epidermal growth factor receptor, transglutaminase 1 and involucrin were quantified. Finally, latanoprost ophthalmic solution or its vehicle was administered at suprapharmacologic doses (two 30 μL drops twice daily in 1 eye for 1 year in monkey eyes, and corneal pachymetry was performed at baseline and at weeks 4, 13, 26 and 52. Results In the 3-D corneal epithelial culture assays, there were no significant differences in cytotoxicity between the BAC-containing latanoprost and olopatadine ophthalmic solutions and BAC-free travoprost ophthalmic solution at either the 10- or 25-minute time points. The 3-D cultures expressed higher levels of corneal epithelial markers than the HCE-T monolayers, indicating a greater degree of differentiation. There were no significant differences between the corneal thickness of monkey eyes treated with latanoprost ophthalmic solution or its vehicle (both containing 0.02% BAC and untreated eyes. Conclusion The lack of cytotoxicity demonstrated in 3-D corneal cultures and in monkey studies suggests that the levels of BAC

  2. Linear attenuation (or absorption) coefficient of gamma radiation for dilute solutions of potassium chloride

    International Nuclear Information System (INIS)

    The mass attenuation and energy absorption coefficients are basic quantities used in calculations of photon energy transport and deposition for radiation dosimetry. This report describes a study of the concentration dependence of the attenuation of γ radiation of various energies by KCl solutions of different concentration. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Tianfu; Pruess, Karsten

    2001-10-01

    Understanding movement of saline sodium nitrate (NaNO{sub 3}) 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 NaNO{sub 3} solutions on fluid flow in unsaturated media. We first present mathematical expressions for the dependence of density, viscosity, solubility and vapor pressure of NaNO{sub 3} 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 NaNO{sub 3} solutions, we also present a comparison of thermophysical properties of both salt solutions. We have implemented the functional thermophysical properties of NaNO{sub 3} solutions into a new TOUGH2 equation-of-state module EWASG-NaNO{sub 3}, 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

  4. Solubility of proline-leucine dipeptide in water and in aqueous sodium chloride solutions from T = (288.15 to 313.15) K

    International Nuclear Information System (INIS)

    Solubility of proline-leucine dipeptide, in water and in aqueous sodium chloride solutions, was measured at T = (288.15, 298.15, 308.15 and 313.15) K as a function of electrolyte concentration m = (0.1, 0.25, 0.5, 0.75 and 1) mol . kg-1 of water. Solubility data has been evaluated from density measurements using a vibrating tube densimeter. It has been observed that sodium chloride renders the dipeptide proline-leucine more soluble in water. Salting-in coefficients and standard free energies of transfer of proline-leucine, from water to aqueous sodium chloride solutions, have been calculated from the solubility data. Standard enthalpies and entropies of transfer have also been estimated and interpreted in terms of electrostatic and hydrophobic perturbed domains in the hydration shells of the dipeptide and of the cation and anion of the salt, as a function of temperature and salt concentration

  5. Effects of applied potential on the fatigue behavior of Alloy 600 in sodium chloride solution

    International Nuclear Information System (INIS)

    The fatigue crack growth (FCG) rates of mill annealed Alloy 600 in 0.1 M NaCl solution, 25 C, were studied by a fracture mechanics test method and were affected by the applied potential, load frequency and load ratio. At an applied cathodic potential of -1,300mVSCE, the FCG rates increased with lowering, the load frequency and with increasing the load ratio. The enhanced FCG rate was found in the lower load frequencies (≤< 0.1 Hz) and was more significant with increasing the load ratio. The secondary cracks and transgranular fracture modes were observed on the fractured surfaces with applied cathodic potential. The possible hydrogen-assisted cracking mechanism on enhancing the FCG rates of Alloy 600 cathodically charged in 0.1 M NaCl solution, 25 C, is discussed in this paper. This study is pertinent to the fatigue cracking problems occurring in steam generator tubes of PWR

  6. 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.

  7. 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.

  8. Exchange of uranium (6) ions on nitrogen-phosphorus-containing polyampholytes in chloride-fluoride solutions

    International Nuclear Information System (INIS)

    Uranium sorption from UO2Cl2 solutions containing HCl, NH4Cl and HF by polyampholytes ANKF-1, ANKF-2 and ANKF-3G is investigated. Effect of HCl, NH4Cl and HF in a wide concentration range is shown. On the basis of data on the sorption, results of analysis and IR spectroscopy conclusions are made on the composition of the ions sorbed and forms of their bond with functional groups. Mathematical model of the sorption process is suggested

  9. 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

  10. 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...

  11. 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...

  12. 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.

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

    International Nuclear Information System (INIS)

    Highlights: ► A better knowledge of the electrochemical behaviour of a martensitic stainless steel in bulk electrolyte was obtained. ► Quantitative parameters were obtained from impedance measurements. ► The study will be used as reference to investigate crevice corrosion using a thin layer cell. - Abstract: 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 potential, the stainless steel was in the passive state and the corrosion process was controlled by the properties of the passive film formed during air exposure. During immersion in the deaerated solution, the passive film was only slightly modified, whereas it was altered both in composition and thickness during immersion in the aerated solution. After cathodic polarisation of the stainless steel electrode surface, the oxide film was almost totally removed and the surface appeared to be uniformly active for oxygen reduction. The new passive film, formed at the corrosion potential, was enriched with iron species and less protective. Impedance diagrams allowed the characterisation of both the oxide film (high-frequency range) and the charge transfer process (low-frequency range).

  14. 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.

  15. 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

  16. 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

  17. Uranium (VI) ion exchange on nitrogen-phosphorus-containing polyampholytes in chloride-fluoride solutions

    Energy Technology Data Exchange (ETDEWEB)

    Pakholkov, V.S.; Denisova, L.A.; Richkov, V.A.; Roshchepkina, L.I.

    1988-09-01

    The adsorption of uranium form UO/sub 2/Cl/sub 2/ solutions containing HCl, NH/sub 4/Cl, and HF has been studied using polyampholyte resins ANKF-1, ANKF-2, and ANKF-3D. The effects of HCl, NH/sub 4/Cl, and HF over broad concentration ranges on uranium adsorption have also been investigated. Based on adsorption data and the results of elemental analysis and IR spectroscopy conclusions have been drawn concerning the composition of adsorbed ions and their binding forms with functional groups. A mathematical model to describe the adsorption process has been proposed.

  18. Mechanism of Cl2- formation during pulsed radiolysis of neutral aqueous solutions of alkali metal chlorides

    International Nuclear Information System (INIS)

    The kinetics of accumulation and destruction of Cl2- in pulsed radiolysis of neutral aqueous solutions of KCl has been investigated. It is assumed that the process mechanism includes the reactions [H3O+...OH]+Cl- → Cl+2H2O (1). It is shown that reaction (2) is the rate-limiting stage of formation of Cl2-. Using a computer the authors calculated the rate constants of reactions (2) and (3), which were found to be equal to 7.6x105 l/molxsec and 1.7x1010 l/molxsec, respectively

  19. 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...

  20. A Comparative Study on the Electrochemical Corrosion Behavior of Iron and X-65 Steel in 4.0 wt % Sodium Chloride Solution after Different Exposure Intervals

    Directory of Open Access Journals (Sweden)

    El-Sayed M. Sherif

    2014-07-01

    Full Text Available In this work, the results obtained from studying the anodic dissolution of pure iron and API X-65 5L pipeline steel after 40 min and 12 h exposure period in 4.0 wt % NaCl solutions at room temperature were reported. Potential-time, electrochemical impedance spectroscopy, potentiodynamic polarization, and chronoamperometric current-time at constant potential techniques were employed. It has been found that the iron electrode corrodes in the chloride test solutions faster than the API X-65 5L steel does under the same conditions. Increasing the exposure period for the electrodes from 40 min to 12 h showed a significant reduction in the corrosion parameters for both iron and steel in the 4.0 wt % NaCl solution. Results together confirmed clearly that the X-65 steel is superior to iron against corrosion in sodium chloride solutions.

  1. Selective extraction of palladium(II) ions from chloride solutions with pyridinecarboxamides

    International Nuclear Information System (INIS)

    A huge demand for noble metals, such as Pd(II), Ru(III), Rh(III), Pt(IV) etc., as value added components in metal alloys is observed. Solvent extraction is very suitable method for their recovery from low concentrated sources. The aim of presented work was to find the conditions for selective extraction with N-dodecylpyridine-3-carboxyamide (3-C12) and N-dodecylpyridine-4-carboxyamide (4-C12) of Pd(II) from hydrochloric acid solutions of various concentrations in the presence of Pb(II), Cu(II), Ni(II), Fe(III), Rh(III), Ru(III) or Pt(IV). It has been shown that N-alkylpyridinecarboxyamides are effective extractants in comparison with commercial chelating extractant ACORGA CLX50

  2. 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.

  3. 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...

  4. 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

  5. Adsorption of uranium (VI) from mixed chloride-fluoride solutions by anion-exchange resins

    Energy Technology Data Exchange (ETDEWEB)

    Pakholkov, V.S.; Denisova, L.A.; Rychkov, V.N.; Kurnosenko, N.A.

    1988-03-01

    Experimental data are reported and discussed concerning the adsorption of uranium from 0.025 M solutions of UO/sub 2/Cl/sub 2/, containing HCl, HF, and NH/sub 4/Cl over a wide concentration range, using anion-exchange resins of varying basicities. UV and IR spectroscopic studies were conducted in order to clarify the chemical mechanism of uranium adsorption. Adsorption isotherms for all of the ion-exchange resins studied are convex in shape and can be described by the following equations: log K/sub d/ = a + b (-log C/sub e/), and log A = a + (b + 1) log C/sub e/, where A is the adsorptivity in mmole U/g; K/sub d/ is the distribution coefficient in mg/liter; and C/sub e/ is the equilibrium concentration of U in mmole/ml. General mathematical models have been obtained to describe the adsorption process; these consist of a system of regression equations derived from the results of a complete 2/sup 3/ factorial study.

  6. 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.

  7. 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}.

  8. Environmentally Assisted Cracking of Alloy 7050-T7451 Exposed to Aqueous Chloride Solutions

    Science.gov (United States)

    Braun, Reinhold

    2016-03-01

    The stress corrosion cracking (SCC) behavior of 7050-T7451 plate material was investigated in short-transverse direction performing constant load and constant extension rate tests. Smooth and notched tensile specimens were permanently immersed in substitute ocean water and in an aqueous solution of 0.6 M NaCl + 0.06 M (NH4)2SO4. Alloy 7050-T7451 exhibited high SCC resistance in both synthetic environments. However, conducting cyclic loading tests, environment-induced cracking was observed. Applying a sawtooth waveform, notched tensile specimens were strained under constant load amplitude conditions at constant displacement rates ranging from 2 × 10-6 to 2 × 10-4 mms-1. The stress ratio R = σ min/ σ max was 0.1 with maximum stresses of 300 and 400 MPa. When cyclically loaded in substitute ocean water, notched specimens failed predominantly by transgranular environment-induced cracking. Striations were observed on the cleavage-like facets. The number of cycles-to-failure decreased with decreasing displacement rate. A slope of 0.5 was obtained by fitting the logarithmic plot of number of cycles-to-failure vs nominal loading frequency, indicating a hydrogen embrittlement mechanism controlled by diffusion.

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

    Directory of Open Access Journals (Sweden)

    Z. RAKOCEVIC

    1999-11-01

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

  10. Influence of chloride ions on the open circuit potentials of chromium in deaerated sulfuric acid solutions

    Directory of Open Access Journals (Sweden)

    BORE JEGDIC

    2006-11-01

    Full Text Available Open circuit potential measurements and cyclic voltammetry of chromium in deaerated aqueous H2SO4 solution of pH 1 without and containing NaCl in the concentration range 0.5 – 4 M revealed that chromium exhibits two stable open circuit potentials having the character of a Wagner–Traud corrosion potential. One, Ecorr.1, was established on the passive surface formed by exposing Cr previously to air or passivated potentiostacially in a controlled manner, and the second one, Ecorr.2, at the bare Cr surface obtained by prolonged cathodic activation. There is a small difference in the Ecorr.1 values as a function of the passive layer properties. Addition of NaCl accelerates the hydrogen evolution reaction on the passive surface to some extent, while the same reaction on the bare surface was not affected by NaCl. On the other hand, presence of NaCl accelerates the anodic reaction on the bare surface, and it activates the dissolution of the passive layer so that the passive currents increase with addition of NaCl. This effect is so large that at concentration of NaCl larger than 3 M, the destruction of the passive layer was so fast that in a matter of seconds the Cr was activated, and the only one stable corrosion potential observed was Ecorr.2. No pitting of Cr in the presence of NaCl was observed up to the transpassive potentials.

  11. Structural characterization of zinc(II) chloride in aqueous solution and in the protic ionic liquid ethyl ammonium nitrate by x-ray absorption spectroscopy

    Science.gov (United States)

    D'Angelo, Paola; Zitolo, Andrea; Ceccacci, Francesca; Caminiti, Ruggero; Aquilanti, Giuliana

    2011-10-01

    Extended x-ray absorption fine structure (EXAFS) spectroscopy has been used to investigate the species and structures existing in a series of ZnCl2-H2O-NaCl solutions with different chloride/zinc ratios and in a solution of ZnCl2 in the protic ionic liquid ethyl ammonium nitrate (EAN). The average coordination numbers and distances of zinc species were determined from the analysis of the EXAFS data. In aqueous solution the number of chloride ions tightly bounded to Zn2+ is significantly related to the chloride/zinc ratio, and no inner complex formation between Zn2+ and Cl- ions has been detected for low ZnCl2 concentration (0.1 and 0.2 M). Conversely, in the same concentration range (0.13 M) the ZnCl2 species do not dissociate in EAN and the Zn2+ first coordination shell has two chloride ions and is completed by two oxygen atoms of the nitrate anion. The results of this investigation show that notwithstanding the existence of similar characteristics between EAN and water, the solvation properties of the two solvents are markedly different.

  12. Mass transport in aqueous zinc chloride-potassium chloride electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Leaist, D.G.

    1986-09-01

    Conductimetric and diaphragm cell techniques have been used to measure ternary diffusion coefficients for aqueous zinc chloride-potassium chloride solutions at 25/sup 0/C. At low concentrations where Zn/sup 2 +/ is the major zinc-transporting species, the diffusion-induced electric field along zinc chloride concentration gradients drives large co-current flows of potassium chloride. In concentrated solutions where a large proportion of zinc diffusses as anionic ZnCl/sub 3//sup -/ and ZnCl/sub 4//sup 2 -/ complexes, flow of zinc chloride generates counterflow of potassium chloride. If a sharp zinc chloride is formed in an otherwise uniform solution of potassium chloride, coupled diffusion can concentrate potassium ions within the diffusion boundary. Equations are developed to predict multicomponent transport coefficients for zinc chloride in supporting electrolytes.

  13. 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

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

    International Nuclear Information System (INIS)

    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

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. Studies of removal of palladium(II) ions from chloride solutions on weakly and strongly basic anion exchangers.

    Science.gov (United States)

    Hubicki, Z; Wołowicz, A; Leszczyńska, M

    2008-11-30

    Palladium and its compounds find wide application in industry as a catalytic agent in different manufacture processes. Recovery of precious metals from industrial wastes is difficult and time consuming but in spite of these disadvantages it becomes profitable. Palladium(II) ions sorption from various chloride solutions of the composition: 0.1-6.0M HCl-0.00056 M Pd(II), 1.0M ZnCl(2)-0.1M HCl-0.00056 M Pd(II), 1.0M AlCl(3)-0.1M HCl-0.00056 M Pd(II) on the weakly and strongly basic anion exchangers (Varion ATM, Varion ADM and Varion ADAM) was discussed. The sorption research of Pd(II) ions on these resins was carried out by means of static and dynamic methods. The dynamic processes were applied in order to determine the breakthrough curves of Pd(II) ions. Moreover, the working ion-exchange capacities as well as the weight and bed distribution coefficients were determined from the Pd(II) breakthrough curves. The recovery factors of Pd(II) ions (% R) depending on the phase contact time were obtained by means of static methods. The highest ion-exchange capacities for the 0.1-6.0M HCl-0.00056 M Pd(II) systems were obtained for the weakly basic ion-exchange resin Varion ADAM. PMID:18358602

  20. Chloride as tracer of solute transport in the aquifer-aquitard system in the Pearl River Delta, China

    Science.gov (United States)

    Kuang, Xingxing; Jiao, Jiu Jimmy; Wang, Ya

    2016-02-01

    A 1D numerical model is constructed to investigate the impact of sedimentation and sea level changes on transport of Cl- in the aquifer-aquitard system in the Pearl River Delta (PRD), China. The model simulates the evolution of the vertical Cl- concentration profiles during the Holocene. Sedimentation is modeled as a moving boundary problem. Chloride concentration profiles are reconstructed for nine boreholes, covering a wide area of the PRD, from northwest to southeast. Satisfactory agreement is obtained between simulated and measured Cl- concentration profiles. Diffusion solely is adequate to reproduce the vertical Cl- concentration profiles, which indicates that diffusion is the regionally dominant vertical transport mechanism across the aquitards in the PRD. The estimated effective diffusion coefficients of the aquitards range from 2.0 × 10-11 to 2.0 × 10-10 m2/s. The effective diffusion coefficients of the aquifers range from 3.0 × 10-11 to 4.0 × 10-10 m2/s. Advective transport tends to underestimate Cl- concentrations in the aquitard and overestimate Cl- concentrations in the basal aquifer. The results of this study will help understand the mechanisms of solute transport in the PRD and other deltas with similar geological and hydrogeological characteristics.

  1. Kinetic and equilibrium studies of the removal of cadmium ions from acidic chloride solutions by hydrophobic pyridinecarboxamide extractants

    International Nuclear Information System (INIS)

    Liquid-liquid extraction of cadmium(II) from acidic chloride solutions was carried out with alkyl derivatives of pyridinecarboxamide in toluene with addition of 2-ethylhexan-1-ol as modifier. Equilibrium as well as kinetic studies was performed. The kinetic studies of a Cd(II) extraction process were carried out with a Lewis cell having a constant interfacial area. Cadmium(II) concentration in the aqueous phases was determined by atomic absorption spectroscopy (Varian SPECTR AA800). The results of equilibrium experiments showed that cadmium(II) was quantitatively extracted with N,N-dihexylpyridine-3-carboxamide whereas the derivative N,N-dihexylpyridine-2-carboxamide was not able to transfer Cd(II) ions from the aqueous phase to the organic one. Thus, the kinetics of extraction and the initial extraction rate were examined only in the systems with N,N-dihexylpyridine-3-carboxamide. The obtained experimental data as well as the calculated values of mass transfer coefficients suggest that the investigated process of extraction of Cd(II) by means of pyridinecarboxamide as extractant occurs in the mixed diffusion-kinetic region. Moreover, the results of adsorption studies indicated that the extraction of Cd(II) with a hydrophobic extractant should be considered as an interfacial process.

  2. 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.

  3. comportamiento del consumidor

    Directory of Open Access Journals (Sweden)

    Erico Rentería Pérez

    2006-01-01

    Full Text Available En este artículo se analiza el posicionamiento exitoso de los profesionales, particularmente los jóvenes, a partir de las nuevas realidades del mundo y del mercado laboral, así como la empleabilidad como constructo, estrategias posibles y, finalmente, una discusión sobre falacias y realidades de discursos sobre mercado de trabajo profesional. La reflexión se liga a dos investigaciones, y a redes de discusión en Brasil y Colombia, que reflexionan sobre las implicaciones y requerimientos estratégicos que marcan el ingreso o permanencia en el mercado de trabajo de profesionales jóvenes, y se reconoce que esto afecta a otros tipos de profesionales. La investigación de Rentería (2006ª sobre Empleabilidad arroja información sobre las dos primeras partes. La de Enríquez y Rentería (2006 sobre Estrategias de aprendizaje y empleabilidad informa sobre la tercera. Apoyan la discusión elementos de psicología y comportamiento del consumidor. Se discute la inclusión social y calidad de vida por el trabajo.

  4. The study of method of removing chloride ion in the solution of MIPR (medical isotopes production reactor)

    International Nuclear Information System (INIS)

    By prepare the silver impregnated alumina adsorbents under the different ignition temperature to research and explore its capacity of remove chloride ions in this article. The result show the adsorbent can remove chloride ion effectively under the conditions of neutral at 700 degree C. And study the adsorbents' capacity of remove chloride ions and silver ions in nitric acid system. The result show that on 0.02 mol/L nitrate system the effect of Dechlorination column to remove the chloride ions is the best, and in the uranium samples in addition to the simulation the effect of in addition to Yinzhu to remove the silver ions is very good, almost all removed. (authors)

  5. Structural effects and microheterogeneity in concentrated solutions and their role in the formation of chloride complexes of cadmium

    International Nuclear Information System (INIS)

    Processes of cadmium chloride complexes formation in the systems CdAn2-Nacl-H2O, where An = Cl-, ClO4-, NO3-, were studied by the methods of polythermal solubility, 1H NMR and Raman spectroscopy. It was ascertained that in the range of pre-eutectic concentrations of cadmium salts all possible forms of cadmium chloride complexes are formed, while in post-eutectic range the process of the complex formation is of structurally enforced character. Mechanisms of chloride complexes formation in perchlorate and nitrate systems are suggested. The conclusion is made that in contrast to chloride system the nitrate and perchlorate systems in the presence of NaCl are characterized by structural microheterogeneity

  6. Permeability of solutes through cellophanes grafted with vinyl monomers. I. Diffusion of potassium chloride, urea, and uric acid

    International Nuclear Information System (INIS)

    The diffusive permeability of potassium chloride, urea, and uric acid through cellophanes grafted with acrylamide, acrylic acid, styrene, and N-vinyl-2-pyrrolidone by γ-ray irradiation was studied. The diffusive permeability coefficients of the permeants through the grafted cellophanes were increased with increase in hydration of the grafted membranes, except for the permeation of potassium chloride through cellophanes grafted with acrylic acid. The permeation of potassium chloride, urea, and uric acid through the various grafted cellophanes is explained by the free volume concept of homogeneously water-swollen membranes. However, the behavior of the permeation of potassium chloride through cellophane grafted with acrylic acid deviated from that of nonionic membranes because of the contribution of the electrical interaction between electrolyte and charge of the membrane. 4 figures, 3 tables

  7. 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.

  8. The electrochemical behaviour of stainless steel AISI 304 in alkaline solutions with different pH in the presence of chlorides

    International Nuclear Information System (INIS)

    Highlights: → The passivation and passivation breakdown of AISI 304 in alkaline solutions with different pH was studied. → The electrochemical behaviour and the corrosion resistance in chloride environments were evaluated using d.c. potentiodynamic polarization and electrochemical impedance spectroscopy. → The results were modelled using a hierarchically distributed circuit and revealed a more susceptible surface at pH 9. → The passive film characterization was carried out by SEM and EDS analysis, revealing the existence of MnS inclusions and the increase of Cr/Fe ratio in the attacked areas, preferably the vicinity of those inclusions. - Abstract: Nowadays, stainless steel reinforcements appear as an effective solution to increase the durability of reinforced concrete structures exposed to very aggressive environments. AISI 304 is widely used for this purpose. Although the improved durability of reinforcing AISI 304, when compared to carbon steel, there is a high probability of pitting susceptibility in the presence of chlorides. Thus, the present work aims at studying the passivation and passivation breakdown of AISI 304 in alkaline solutions of different pH (pH from 13 to 9), simulating the interstitial concrete electrolyte. These solutions were contaminated with different concentrations of chloride ions (3% and 10%, as NaCl). The electrochemical behaviour was evaluated by d.c. potentiodynamic polarization and by electrochemical impedance spectroscopy (EIS). The morphological features and the changes observed in the surface composition were evaluated by Scanning Electron Microscopy (SEM) together with EDS chemical analysis. The results evidence that pH plays an important role in the evolution of the film resistance and charge transfer processes. Moreover, the effect is highly dependent upon the chloride content and immersion time.

  9. 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...

  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. Liquid-liquid extraction/separation of platinum(IV) and rhodium(III) from acidic chloride solutions using tri-iso-octylamine

    International Nuclear Information System (INIS)

    Liquid-liquid extraction/separation of platinum(IV) and rhodium(III) from acidic chloride solutions was carried out using tri-iso-octylamine (Alamine 308) as an extractant diluted in kerosene. The percentage extraction of platinum(IV) and rhodium(III) increased with increase in acid concentration up to 8 mol L-1. However, at 10 mol L-1 HCl concentration, the extraction behavior was reversed, indicating the solvation type mechanism during extraction. The quantitative extraction of ∼98% platinum(IV) and 36% rhodium(III) was achieved with 0.01 mol L-1 Alamine 308. The highest separation factor (S.F. = 184.7) of platinum(IV) and rhodium(III) was achieved with 0.01 mol L-1 Alamine 308 at 1.0 mol L-1 of hydrochloric acid concentration. Alkaline metal salts like sodium chloride, sodium nitrate, sodium thiocyanate, lithium chloride, lithium nitrate, potassium chloride and potassium thiocyanate used for the salting-out effect. LiCl proved as best salt for the extraction of platinum(IV). Temperature effect demonstrates that the extraction process is exothermic. Hydrochloric acid and thiourea mixture proved to be better stripping reagents when compared with other mineral acids and bases.

  12. Evaluation of Chromate as Dezincification Inhibitor for α-brass (Cu/Zn : 64/36) in 3% Chloride Buffer Solutions

    OpenAIRE

    H. H. Rehan; N.A. Al-Moubarak; H.A. Al-Rafai

    2003-01-01

    The inhibition behavior of chromate ions towards corrosion and dezincification of α-brass (Cu/Zn: 64/36) in acetate buffer solutions (pH 2.4, 7.0 and 8.5) containing 3% sodium chloride was studied. Weight loss and solution analysis were used for a long period (four weeks) and electrochemical polarization for a short period (one hour). Chromate accelerated corrosion and dezincification at pH 2.4 by acting as depolarizer but chromate suppressed efficiently the corrosion and dezincification...

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

    Directory of Open Access Journals (Sweden)

    Fatmir Faiku

    2012-01-01

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

  14. 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.

  15. 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

  16. 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...

  17. 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.

  18. Selection of canister materials: electrochemical corrosion tests of HASTELLOY C4 and other Ni-Cr(-Mo) alloys in chloride containing solutions

    International Nuclear Information System (INIS)

    Several Ni-Cr(-Mo) alloys (HASTELLOY C4, INCONEL 625, SANICRO 28, INCOLOY 825, INCONEL 690) were tested by electrochemical methods to characterize their corrosion behaviour in chloride containing solutions at various temperatures and pH-values in respect to their application as canister materials for final radioactive waste storage. Especially, HASTELLOY C4 which proved to have the highest corrosion resistance of all tested alloys was tested by the following electrochemical methods: (1) Poteniodynamic measurements to determine the characteristic potentials, passive current densities and critical pitting potentials. (2) Potentiostatic measurements in order to evaluate the duration of the incubation period at various potentials. (3) Galvanostatic measurements in order to characterize critical pitting potentials. As electrolyte 1 m H2SO4 was used, as parameters temperature, chloride content and pH-value were varied. Variation of temperature gives the following results: an increase in temperature leads to an increase of the critical passivation current density, the passive potential bandwidth decreases slightly and the passive current density increases with rising temperature. The addition of different chloride contents to the H2SO4 solution shows the following effects: the critical passivation current density and the passive current density increase with increasing chloride concentration and both, the critical pitting potentials and the pitting nucleation potentials, shift towards negative values. As third parameter the pH-value was varied. As expected, an increase of the pH-value extends the passive region to more negative values, the passive current density decreases. The variation of the pH-value does not affect the critical pitting potential. All tested alloys showed a clearly limited resistance against pitting corrosion phenomena. However, the best corrosion behaviour is shown by HASTELLOY C4, which has of all tested alloys the lowest passivation current density

  19. 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

  20. 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.

  1. Thick pure palladium film with varied crystal structure electroless deposited from choline chloride–palladium chloride solution without the addition of reductant

    International Nuclear Information System (INIS)

    Immersion deposition procedure was applied to achieve thick pure palladium films with thickness up to about 3 μm from choline chloride (ChCl)–palladium chloride (PdCl2) 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–PdCl2 solution had excellent properties on solderability and corrosion resistance. - Highlights: • Thick pure Pd film was obtained from ChCl–PdCl2 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

  2. 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.

  3. 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...

  4. Phenomenon of magnetic birefringence in solutions of paramagnetic substances. Communication 2. Molar-magneto-optic constants of chlorides and nitrates of some lanthanides in water

    International Nuclear Information System (INIS)

    This paper determines the molar constants of the magnetic birefringence of chlorides and nitrates of some lanthanides in water and extrapolates them to infinite dilution. The principal semiaxes of the optical-polarizability ellipsoids of hydrated rare-earth cations have been evaluated in the axial approximation. The magneto-optic properties of dilute solutions of lanthanide nitrates (Ln = Pr, Nd, Sm, Eu, Gd, Tb, Dy, Er) are attributed to the constancy of the composition and structure of the aquo complexes with the participation of nitrate anions

  5. Correlation between the Increasing Conductivity of Aqueous Solutions of Cation Chlorides with Time and the “Salting-Out” Properties of the Cations

    Directory of Open Access Journals (Sweden)

    Nada Verdel

    2016-02-01

    Full Text Available The time-dependent role of cations was investigated by ageing four different aqueous solutions of cation chlorides. A linear correlation was found between the cations’ Setchenov coefficient for the salting-out of benzene and the increase in the conductivity with time. The conductivity of the structure-breaking cations or the chaotropes increased more significantly with time than the conductivity of the kosmotropes. Since larger water clusters accelerate the proton or hydroxyl hopping mechanism, we propose that the structuring of the hydration shells of the chaotropes might be spontaneously enhanced over time.

  6. 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...

  7. 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.

  8. Rheological behaviour of some saccharides in aqueous potassium chloride solutions over temperature range (288.15 to 318.15) K

    Energy Technology Data Exchange (ETDEWEB)

    Banipal, Parampaul K., E-mail: pkbanipal@yahoo.co [Department of Chemistry, Guru Nanak Dev University, Amritsar 143005 (India); Chahal, Amanpreet K.; Singh, Vickramjeet [Department of Chemistry, Guru Nanak Dev University, Amritsar 143005 (India); Banipal, Tarlok S. [Department of Applied Chemistry, Guru Nanak Dev University, Amritsar 143005 (India)

    2010-08-15

    The viscosities, {eta} of mono-, di-, tri-saccharides and methylglycosides, viz., D(+)-xylose (XYL), D(-)-arabinose (ARA), D(-)-ribose (RIB), D(-)-fructose (FRU), D(+)-galactose (GAL), D(+)-mannose (MAN), D(+)-glucose (GLU), D(+)-melibiose (MEL), D(+)-cellobiose (CEL), D(+)-lactose monohydrate (LAC), D(+)-maltose monohydrate (MAL), D(+)-trehalose dihydrate (TRE), sucrose (SUC), D(+)-raffinose pentahydrate (RAF), {alpha}-methyl-D(+)-glucoside ({alpha}-Me-GLU), methyl-{alpha}-D-xylopyranoside (Me-{alpha}-XYL), and methyl-{beta}-D-xylopyranoside (Me-{beta}-XYL) in water and in (0.5, 1.0, 2.0, and 3.0) mol . kg{sup -1} aqueous solutions of potassium chloride (KCl) have been determined at T = (288.15, 298.15, 308.15, and 318.15) K from efflux time measurements by using a capillary viscometer. Densities used to determine viscosities have been reported earlier. The viscosity data have been utilized to determine the viscosity B-coefficients employing the Jones-Dole equation at different temperatures. From these data, the viscosity B-coefficients of transfer, {Delta}{sub t}B have been estimated for the transfer of various saccharides/methylglycosides from water to aqueous potassium chloride solutions. The {Delta}{sub t}B values have been found to be positive, whose magnitude increases with the increase in concentration of potassium chloride in all cases. The dB/dT coefficients, pair, {eta}{sub AB} and triplet, {eta}{sub ABB} viscometric interaction coefficients have also been determined. Gibbs free energies of activation and related thermodynamic parameters of activation of viscous flow have been determined employing Feakin's transition-state theory. The signs and magnitudes of various parameters have been discussed in terms of solute-solute and solute-solvent interactions occurring in these solutions. The effect of substitution of -OH by methoxy group, -OCH{sub 3} has also been discussed.

  9. Optimization of Preparation of Activated Carbon from Ricinus communis Leaves by Microwave-Assisted Zinc Chloride Chemical Activation: Competitive Adsorption of Ni2+ Ions from Aqueous Solution

    Directory of Open Access Journals (Sweden)

    M. Makeswari

    2013-01-01

    Full Text Available The preparation of activated carbon (AC from Ricinus communis leaves was investigated in this paper. Orthogonal array experimental design method was used to optimize the preparation of AC using microwave assisted zinc chloride. Optimized parameters were radiation power of 100 W, radiation time of 8 min, concentration of zinc chloride of 30% by volume, and impregnation time of 24 h, respectively. The surface characteristics of the AC prepared under optimized conditions were examined by pHZPC, SEM-EDAX, XRD, and FTIR. Competitive adsorption of Ni2+ ions on Ricinus communis leaves by microwave assisted zinc chloride chemical activation (ZLRC present in binary and ternary mixture was compared with the single metal solution. The effects of the presence of one metal ion on the adsorption of the other metal ion were investigated. The experimental results indicated that the uptake capacity of one metal ion was reduced by the presence of the other metal ion. The extent of adsorption capacity of the binary and ternary metal ions tested on ZLRC was low (48–69% as compared to single metal ions. Comparisons with the biosorption of Ni2+ ions by the biomass of ZLRC in the binary (48.98–68.41%-~Ni-Cu and 69.76–66.29%-~Ni-Cr and ternary solution (67.32–57.07%-~Ni–Cu and Cr could lead to the conclusion that biosorption of Ni2+ ions was reduced by the influence of Cu2+ and Cr3+ ions. The equilibrium data of the adsorption was well fitted to the Langmuir isotherm. The adsorption process follows the pseudo-second-order kinetic model.

  10. Preparation of a chitosan-based anionic exchanger for removal of bromide, chloride, iodide and phosphate ions from aqueous solutions

    Directory of Open Access Journals (Sweden)

    Affonso Celso Gonçalves Júnior

    2014-02-01

    Full Text Available The development of a chitosan anion exchanger, obtained from shrimp shells, and its adsorption capacity for chloride, bromide, iodide and phosphate anions are provided. Dependence of exchange processes with the anions as a function of pH and contact time between exchanger and anions were initially investigated. Results showed that the best adsorption of ions occurred at pH 3.0. Exchange isotherms were then developed by the Langmuir, Freundlich and Dubinin-Radushkevich mathematical models. Results demonstrated that chitosan produced from shrimp shells may be used as feedstock in the manufacture of anion exchange microspheres.

  11. Diffusion coefficients of nickel chloride in aqueous solutions of lactose at T = 298.15 K and T = 310.15 K

    International Nuclear Information System (INIS)

    Binary mutual diffusion coefficients (interdiffusion coefficients) of nickel chloride in water at T = 298.15 K and T = 310.15 K, and at concentrations between (0.000 and 0.100) mol · dm-3, using a Taylor dispersion method have been measured. These data are discussed on the basis of the Onsager-Fuoss and Pikal models. The equivalent conductance at infinitesimal concentration of the nickel ion in these solutions at T = 310.15 K has been estimated using these results. Through the same technique, ternary mutual diffusion coefficients (D11, D22, D12, and D21) for aqueous solutions containing NiCl2 and lactose, at T = 298.15 K and T = 310.15 K, and at different carrier concentrations were also measured. These data permit us to have a better understanding of the structure of these systems and the thermodynamic behaviour of NiCl2 in different media.

  12. Funciones expresivas (comportamiento motor y lenguaje), comportamiento emocional y funciones ejecutivas en la discapacidad intelectual

    OpenAIRE

    Grau Rubio, Claudia

    2006-01-01

    Se describen las bases neurológicas del comportamiento motor, lenguaje, funciones ejecutivas y comportamiento emocional en las personas con discapacidad intelectual; las dificultades asociadas y cómo se puede intervenir.

  13. 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...

  14. 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.

  15. Investigation of the main chemical properties of water-magnesium chloride solutions. Application to the understanding of stress corrosion phenomena in 17.12 Mo stainless steel

    International Nuclear Information System (INIS)

    This research thesis reports the investigation of the main chemical properties of concentrated aqueous solutions of MgCl2 and of their influence of stress corrosion of 17Cr-12Ni-2Mo stainless steel. It shows that the most important chemical properties are the equilibrium pH and the acidity range of MgCl2 aqueous solutions, and that they strongly depend on solution temperature and concentration. The medium pH is governed by the increased acidity of water in presence of Mg++ ions, while the acidity range is determined by a hydrolysis reaction of these ions which results in a precipitation of magnesium hydroxyl-chlorides. The investigation of stress corrosion behaviour of the steel in MgCl2 solutions with varying temperature and concentration shows that this behaviour comes down to a prevailing pH effect which results from the variation of these both parameters, with a not negligible but less important effect of temperature. A study of cracking surfaces indicates that it is possible to pass from a transgranular to an intergranular mode by a variation of either media aggressiveness (pH, temperature, voltage) or strain rate. These results are explained by a concept of kinetic factor which limits stress corrosion

  16. Molecular structure and dynamics of an aqueous sodium chloride solution in nano-pores between portlandite surfaces: a molecular dynamics study.

    Science.gov (United States)

    Dongshuai, Hou; Zeyu, Lu; Peng, Zhang; Qingjun, Ding

    2016-01-21

    Portlandite plays an important role in the hydration phase of cement-based materials and influences the strength and durability of such materials. This study describes a molecular dynamics study of the structure and dynamics of water and ions confined at ambient temperature in calcium hydroxyl nanopores with widths of 35 Å. Strong layering of water in the vicinity of the (001) surface of portlandite demonstrates special structural features such as large density, good orientation preference, ordered interfacial organization and low diffusion rate. Due to the fixed vibration and rotation of the hydroxyl groups at the interface, water molecules within the first adsorbed layer adopt both H-downward and H-upward orientations by donating H-bonds and accepting H-bonds from the OH groups in the solid surface. Regarding the interaction of the ions and portlandite, Na(+) ions, deeply rooted in spaces in the surface hydroxyl groups, are significantly slowed and remain near the surface for long periods of time. On the other hand, due to the weak H-bonds formed by chloride ions and hydroxyl groups, adsorbed chloride ions near the surface cannot remain for longer times. In addition, when water and ions are confined in the nano-pores, the residence time for the ion-water and ion-ion clusters is lengthened so that the ion adsorption capability of the porlandite surface is enhanced due to the stable Na-Cl connections in the electrolyte solution. PMID:26687688

  17. Comportamiento Superficial e Interfacial de Soluciones Acuosas Diluidas de Isómeros de Pentanodiol a 288.15K Surface and interfacial behaviour of Dilute Aqueous Solutions of Pentanediol Isomers at 288.15 K

    OpenAIRE

    Manuel S Páez; Armando Alvis; Guillermo Arrazola

    2011-01-01

    Se reportan medidas experimentales de tensión superficial para soluciones acuosas diluidas de 1,2-pentanodiol (12PD), 2,4-pentanodiol (24PD), 1,4-pentanodiol (14PD) y 1,5-pentanodiol (15PD) a 288.15 K como una función de la concentración, usando el método de ascenso capilar. Se discuten las interacciones que ocurren al interior y en la superficie de la solución y se interpreta este comportamiento superficial en términos de cantidades termodinámicas. Los resultados muestran la dependencia de l...

  18. Inhibition properties of self-assembled corrosion inhibitor talloil diethylenetriamine imidazoline for mild steel corrosion in chloride solution saturated with carbon dioxide

    International Nuclear Information System (INIS)

    Highlights: •Corrosion inhibitor talloil diethylenetriamine imidazoline effectively protects mild steel from CO2 corrosion. •Quartz crystal microbalance measurements were used to the investigate kinetics of corrosion inhibitor adsorption. •Adsorption of talloil diethylenetriamine imidazoline can be described by Langmuir adsorption isotherm. -- Abstract: The inhibition effect of talloil diethylenetriamine imidazoline (TOFA/DETA imidazoline) on corrosion of mild steel in chloride solutions saturated with CO2 was investigated by weight loss measurements (WL) and atomic force microscopy (AFM). Adsorption mechanism and kinetics of self-assembled (TOFA/DETA imidazoline) monolayers formation on gold were studied using the quartz crystal microbalance measurements (QCM). WL and AFM results demonstrated that TOFA/DETA imidazoline can effectively protect mild steel surface from corrosion. QCM measurements shown that the adsorption of TOFA/DETA imidazoline onto gold follows Langmuir adsorption isotherm and further investigation of the adsorption process will be carried out on a corroding metal surface

  19. 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.)

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

    Science.gov (United States)

    Mizuhashi, Toshinari; Asakawa, Tsuyoshi; Ohta, Akio

    2015-01-01

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

  1. 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.

  2. 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

  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. 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.

  5. 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. PMID:16457175

  6. ICP-AES and MicroRaman corrosion behaviour investigation on Zn4Sb3 and Al, Ag doped phases in sodium chloride solution

    International Nuclear Information System (INIS)

    Highlights: • Thermoelectrics corrosion behaviour is studied by MicroRaman and ICP-AES methods. • In NaCl solution, pure and Al, Ag doped Zn4Sb3 compounds show only a Zinc release. • Zinc hydroxychlorides are detected as corrosion surface products. • A surface passivation layer preserves bulk from a deep corrosion. -- Abstract: The high thermoelectric performance of the β-phase Zn4Sb3 has drawn much attention for its application in the intermediate temperature range. In this work we explore the corrosion behaviour properties of pure Zn4Sb3 compound and after partial substitution of Zn with Al and Ag. In particular, Zn4Sb3, (Zn1xAlx)4Sb3 and (Zn1xAgx)4Sb3 (x = 0.01) compounds were synthesized using a muffle furnace and characterized in terms of crystal structure, morphology and phases composition (SEM-EDXS, XRD). All samples were placed in 0.1 M NaCl aerated solution at room temperature for 48 days. A study of the amount of cations released in solution was carried out using Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES) analysis. Analytical data reveal a higher value of zinc amount for doped samples. The microRaman spectroscopy analysis carried out on surface corrosion products revealed the presence of anhydrous and hydrate zinc hydroxy chlorides. No worsening on corrosion behaviour of Zn4Sb3 intermetallic compounds was observed after Al or Ag doping

  7. Effects of nitrogen on the passivation of nickel-free high nitrogen and manganese stainless steels in acidic chloride solutions

    International Nuclear Information System (INIS)

    The role of nitrogen on the passivation of nickel-free high nitrogen and manganese stainless steels was investigated in 0.5 M H2SO4, 3.5% NaCl and 0.5 M H2SO4 + 0.5 M NaCl solutions using potentiodynamic polarization, electrochemical impedance spectroscopy and X-ray photoelectron spectroscopy techniques. The passive film stability was enhanced in 0.5 M H2SO4 and the pitting resistance was improved in 3.5% NaCl solution by more nitrogen addition. The influence of nitrogen extended the whole anodic polarization region in 0.5 M H2SO4 + 0.5 M NaCl solution, as demonstrated by the enhanced dissolution resistance, promoted adsorption and passivation process, improved film protection and pitting resistance with increasing nitrogen content. Possible mechanisms relating to the role of nitrogen in different potential regions were discussed.

  8. 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

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

    Science.gov (United States)

    Jin, Z. H.; Ge, H. H.; Lin, W. W.; Zong, Y. W.; Liu, S. J.; Shi, J. M.

    2014-12-01

    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 Rct 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.

  10. Solubility of tungstic acid and species of tungsten transfer in sodium chloride solutions at 25 Deg C

    International Nuclear Information System (INIS)

    Solubility of tungstic acid at room temperature in aqueous solutions with different content of Na+ and Cl- ions in pH range from 0.1 to 7.3 was determined using data of colorimetric analysis. It was ascertained that tungstic acid solubility increases with pH growth and increase in sodium content. Thermodynamic equilibrium constants for diverse tungsten-containing species existing in the solution at 3.5< pH<6 were calculated on the basis of experimental data. Dissociation and complexing reactions constants of tungstic acid were estimated

  11. An electrochemical, long-term immersion, and XPS study of 2-mercaptobenzothiazole as a copper corrosion inhibitor in chloride solution

    International Nuclear Information System (INIS)

    Highlights: • The corrosion process of inhibited Cu is under kinetic and diffusion control. • 2-Mercaptobenzothiazole is a mixed-type corrosion inhibitor. • 2-Mercaptobenzothiazole significantly reduces surface roughness. • General and no localized corrosion occurs in the inhibited solution. • The thickness of the 2-mercaptobenzothiazole surface layer is 1.5 ± 0.5 nm. - Abstract: Using EIS, potentiodynamic curve, 3D-profilometry, and XPS measurements, 2-mercaptobenzothiazole (MBTH) was studied as a corrosion inhibitor for Cu in 3 wt.% NaCl solution. Electrochemical measurements showed that Cu corrosion in MBTH-inhibited solution follows kinetic-controlled and diffusion-controlled processes, that MBTH acts as a mixed-type inhibitor after 100 h of immersion and that it significantly reduces surface roughness after half a year of immersion compared with non-inhibited solution. It is also shown that the N atom and exocyclic S atom of the MBTH are involved in the molecule adsorption. The MBTH surface layer thickness was estimated to be 1.5 ± 0.5 nm

  12. 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. .

  13. Corrosion of Magnesium-Aluminum Alloys with Al-11Si/SiC Thermal Spray Composite Coatings in Chloride Solution

    Science.gov (United States)

    Arrabal, R.; Pardo, A.; Merino, M. C.; Mohedano, M.; Casajús, P.; Matykina, E.

    2011-03-01

    Depositions of Al-11Si coatings reinforced with 5, 15, and 30 vol.% SiC particles (SiCp) were performed onto AZ31, AZ80, and AZ91D magnesium alloys. The influence of substrate composition and SiCp proportion on the anti-corrosion properties of composite coatings was evaluated using DC and AC electrochemical measurements in 3.5 wt.% NaCl solution at 22 °C. The as-sprayed coatings were permeable to the saline solution, and galvanic corrosion occurred at the substrate/coating interface after immersion in the saline solution for a few hours. The addition of SiCp yielded coatings with higher porosity and less effectiveness against corrosion. The application of a cold-pressing post-treatment produced denser coatings with reduced surface roughness, improved hardness, and superior corrosion resistance. However, galvanic corrosion was observed after several days of immersion because of penetration of the 3.5 wt.% NaCl solution through the remaining pores in the coatings.

  14. 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.

  15. 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, ...

  16. Effect of the cation model on the equilibrium structure of poly-L-glutamate in aqueous sodium chloride solution

    Science.gov (United States)

    Marchand, Gabriel; Soetens, Jean-Christophe; Jacquemin, Denis; Bopp, Philippe A.

    2015-12-01

    We demonstrate that different sets of Lennard-Jones parameters proposed for the Na+ ion, in conjunction with the empirical combining rules routinely used in simulation packages, can lead to essentially different equilibrium structures for a deprotonated poly-L-glutamic acid molecule (poly-L-glutamate) dissolved in a 0.3M aqueous NaCl solution. It is, however, difficult to discriminate a priori between these model potentials; when investigating the structure of the Na+-solvation shell in bulk NaCl solution, all parameter sets lead to radial distribution functions and solvation numbers in broad agreement with the available experimental data. We do not find any such dependency of the equilibrium structure on the parameters associated with the Cl- ion. This work does not aim at recommending a particular set of parameters for any particular purpose. Instead, it stresses the model dependence of simulation results for complex systems such as biomolecules in solution and thus the difficulties if simulations are to be used for unbiased predictions, or to discriminate between contradictory experiments. However, this opens the possibility of validating a model specifically in view of analyzing experimental data believed to be reliable.

  17. 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)

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

    Science.gov (United States)

    Zhou, Biner; Wang, Yishan; Zuo, Yu

    2015-12-01

    The evolution of the corrosion process of AA 2024-T3 in 0.58 g L-1 NaCl solution (pH 10) with sodium dodecylbenzenesulfonate (SDBS) and lanthanum chloride inhibitors was studied with electrochemical and surface analysis methods. With the addition of the compounded LaCl3 and SDBS inhibitors, in the early stage the polarization behavior of AA 2024-T3 changed from active corrosion to passivation, and both the general corrosion and pitting corrosion were inhibited. However, with the immersion time extended, the passive behavior gradually disappeared and pitting happened at the Cu-rich phases. After 24 h immersion, the compounded inhibitors still showed good inhibition for general corrosion, but the polarization curve again presented the characteristic similar to active polarization. The compounded inhibitors also inhibited the pitting corrosion to some extent. The acting mechanism of the inhibitors SDBS and La3Cl on the corrosion process of AA 2024-T3 in the test solution was discussed.

  19. Diffusion coefficients of nickel chloride in aqueous solutions of lactose at T = 298.15 K and T = 310.15 K

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Ana C.F., E-mail: anacfrib@ci.uc.p [Department of Chemistry, University of Coimbra, 3004-535 Coimbra (Portugal); Gomes, Joselaine C.S., E-mail: leidygomes18@hotmail.co [Department of Chemistry, University of Coimbra, 3004-535 Coimbra (Portugal); Barros, Marisa C.F., E-mail: marisa.barros@gmail.co [Department of Chemistry, University of Coimbra, 3004-535 Coimbra (Portugal); Lobo, Victor M.M., E-mail: vlobo@ci.uc.p [Department of Chemistry, University of Coimbra, 3004-535 Coimbra (Portugal); Esteso, Miguel A., E-mail: miguel.esteso@uah.e [Departamento de Quimica Fisica, Facultad de Farmacia, Universidad de Alcala, 28871, Alcala de Henares (Madrid) (Spain)

    2011-03-15

    Binary mutual diffusion coefficients (interdiffusion coefficients) of nickel chloride in water at T = 298.15 K and T = 310.15 K, and at concentrations between (0.000 and 0.100) mol {center_dot} dm{sup -3}, using a Taylor dispersion method have been measured. These data are discussed on the basis of the Onsager-Fuoss and Pikal models. The equivalent conductance at infinitesimal concentration of the nickel ion in these solutions at T = 310.15 K has been estimated using these results. Through the same technique, ternary mutual diffusion coefficients (D{sub 11}, D{sub 22}, D{sub 12}, and D{sub 21}) for aqueous solutions containing NiCl{sub 2} and lactose, at T = 298.15 K and T = 310.15 K, and at different carrier concentrations were also measured. These data permit us to have a better understanding of the structure of these systems and the thermodynamic behaviour of NiCl{sub 2} in different media.

  20. In situ synchrotron X-ray diffraction study of scale formation during CO2 corrosion of carbon steel in sodium and magnesium chloride solutions

    International Nuclear Information System (INIS)

    Highlights: ► We studied the scale formation processes of carbon steel in CO2 saturated brine at 80 °C. ► Protective scales were formed in all tests. ► Only FeCO3 formed in saturated brine while Fe(OH)2CO3 detected with presence of MgCl2. ► MgCl2 accelerates the onset of siderite precipitation. - Abstract: In situ synchrotron X-ray diffraction was used to follow the formation of corrosion products on carbon steel in CO2 saturated NaCl solution and mixed NaCl/magnesium chloride (MgCl2) at 80 °C. Siderite (FeCO3) was the only phase formed in NaCl solution, while Fe(OH)2CO3 was also detected when MgCl2 was present. The proposed model is that siderite precipitation, occurring once the critical supersaturation was exceeded within a defined boundary layer, caused local acidification which accelerated the anodic dissolution of iron. The current fell once a complete surface scale was formed. It is suggested that MgCl2 addition decreased the required critical supersaturation for precipitation.

  1. 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.

  2. Effect of Zn and Pb contents on the electrochemical behavior of brass alloys in chloride-free neutral sulfate solutions

    Energy Technology Data Exchange (ETDEWEB)

    Ismail, K.M.; El-Sherif, R.M.; Badawy, W.A. [Cairo Univ., Giza (Egypt). Dept. of Chemistry

    2004-11-01

    Different electrochemical methods such as open-circuit potential measurements, polarization techniques and electrochemical impedance spectroscopy (EIS) were used to investigate the electrochemical behavior of brass alloys with various Zn contents (5.5-38.0 mass%) and Cu-38.0Zn-Pb alloy with different Pb contents (1.0-3.4 mass%) in neutral sodium sulfate solutions. The influence of working conditions, e.g., immersion time, sulfate ions concentration and temperature on the electrochemical behavior of the different alloys was also studied. It was found that the initial corrosion rate is relatively high for alloys with the higher zinc content due to dezincification. The dezincification process initiates by selective dissolution of zinc and continues by a simultaneous dissolution of copper and zinc followed by re-deposition of copper. An increase in the lead content and immersion time in the sodium sulfate solution increases the corrosion resistance of the alloy and improves its stability. The stability of the leaded brass was considered to be due to the formation of an insoluble film of lead sulfate on its surface. The impedance data were fitted to theoretical data obtained according to an equivalent circuit model describing the electrode/electrolyte interface. The mechanism of the alloy dissolution was discussed in view of the obtained results. (Author)

  3. Durability of API class B cement pastes exposed to aqueous solutions containing chloride, sulphate and magnesium ions

    Directory of Open Access Journals (Sweden)

    Hernández, M. E.

    2008-12-01

    Full Text Available This paper discusses a durability study conducted on API class B cement, the type used in shallow oil wells, when exposed to aggressive formation water. Its resistance to the major ions, namely –SO4=, Mg+2 and Cl-–, is related both to its capacity to assimilate the aggressive action of each harmful agent and to the changes in the chemical reactivity of some of its components. The methodology used consisted in preparing and immersing cement specimens in neutral solutions containing variable concentrations of these ions to monitor the chemical reactions taking place. These solutions were analyzed and XRD studies were conducted for over a year to identify mineralogical variations. The purposes of the study were to determine the effects of joint ionic attack on this kind of cement and to monitor the variations in the calcium concentration in the aqueous solutions of Na2SO4, MgCl2 and NaCl in contact with API class B cement pastesEste trabajo se basa en el estudio de la durabilidad de un cemento API clase B, utilizado en pozos petrolíferos someros, frente a la agresividad de las aguas de formación a las que puede estar expuesto. Su eficacia frente a la exposición a los iones más importantes –SO4=, Mg+2 y Cl-– se relaciona con su capacidad de asimilar la acción agresiva de cada agente perjudicial, así como de las reacciones químicas que sufra por la reactividad de alguno de sus compuestos. La metodología aplicada supone la preparación de probetas de este cemento y su inmersión en disoluciones neutras, conteniendo los referidos iones a distintas concentraciones, para evaluar el desarrollo de las reacciones existentes en su seno. A tal fin se realizaron análisis de las disoluciones y estudios de DRX durante más de un año para conocer su evolución mineralógica. El objetivo del trabajo ha sido determinar los efectos resultantes de los ataques conjuntos de los citados iones al referido cemento; así como la observación de las

  4. Effect of strong magnetic fields on relative oxygen/chlorine evolution efficiencies in magnetolelectrolysis of sodium chloride solutions

    International Nuclear Information System (INIS)

    This paper reports the effect of a magnetic field of 5T on anodic reactions in electrolysis of 3.5% NaCl solutions investigated by measuring relative oxygen/chlorine evolution efficiencies at a Pt plate anode. No significant difference in the oxygen evolution efficiency between in magnetoelectrolysis at 5T and in the zero magnetic field was observed for an electrolysis time of 30 sec. When magnetoelectrolysis at 5T was carried out for 90 sec the oxygen evolution efficiency became higher by about 5% than that at OT. The imposed magnetic field seems to have an effect of increasing the oxygen evolution efficiency, cancelling out the effect of the decrease in pH of the anolyte during electrolysis

  5. Cooper hydrometallurgy and extraction from chloride media

    International Nuclear Information System (INIS)

    The development of copper hydrometallurgy is presented and various processes proposed for copper recovery from sulphide concentrates are discussed. Leaching, extraction and stripping are considered, including reagents and processes. The extraction of copper from chloride solutions is discussed. Various extractants are presented and their use for copper transfer from chloride solutions to the organic phase and back to chloride and to sulphate solutions is discussed. (author) 4 refs

  6. Effect of temperature and heat fluxes on the corrosion's damage nature for mild and stainless steels in neutral chloride solutions

    Energy Technology Data Exchange (ETDEWEB)

    Kaluzhina, S.A. [Voronezh State University, University Sq.1, 394006 Voronezh (Russian Federation); Malygin, A.V. [JSC Voronezhsynthezkauchuk, Leninsky Av. 2, 394014 Voronezh (Russian Federation); Vigdorovitch, V.V. [Derzhavin State University, International St. 33, 392622 Tambov (Russian Federation)

    2004-07-01

    The detail research of the corrosion-electrochemical behavior of two types steels - mild steel (0.1%C) and stainless steel 12FeCr18Ni10Ti in series chloride solutions under elevated temperature and heat flux on interface has been carried out in the present work using the special plant and the complex electrochemical and microscopic methods. The comparative data has shown that the temperature increase is stimulating as the active alloy's corrosion (mild steel), so the passive alloy's corrosion (12FeCr18Ni10Ti).However at the last case the temperature effect is being higher because the thermal de-passivation of the stainless steel which undergoes pit corrosion under t > 50 deg C. The heat-transfer role in the studied systems is ambiguous. The corrosion rate of heat-transferring electrode from mild steel exceeds the thermo-equilibrium with solution electrode's corrosion rate because of intensification of the oxygen reduction cathodic process. The opposite effect has been established for steel 12FeCr18Ni10Ti where the oxygen flux's strengthening from cold solution to the heated surface transfers the alloy to the most stable passive state and increases its resistance to general and local corrosion. The experimental results demonstrates that the thermal condition's influence on the nature and corrosion intensity of the investigated steels is being commensurable by effect's degree with their composition and showing strictly individually. (authors)

  7. 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.

  8. 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

  9. 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

  10. Corrosion protection of AA 2024-T3 by bis-[3-(triethoxysilyl)propyl]tetrasulfide in neutral sodium chloride solution. Part 1: corrosion of AA 2024-T3

    International Nuclear Information System (INIS)

    This study consists of two parts. In the first part, the corrosion of 2024-T3 aluminum alloy (AA 2024-T3) was studied using scanning electron microscopy and energy-dispersive X-ray spectroscopy. The results showed that the anodic S phase (Al2CuMg) particles dealloyed Al and Mg during the 3.5 h of immersion in a neutral 0.6 M sodium chloride (NaCl) solution; with the dealloying of Mg being the most severe. Simultaneously, a heavy dissolution was also observed for the surrounding Al matrix of the S phase particles. This Al dissolution is likely to be caused by a local alkalization resulting from the coupled cathodic reaction (water and/or oxygen reduction). Such corrosion in AA 2024-T3, however, can be inhibited efficiently after the treatment of bis-[3-(triethoxysilyl)propyl]tetrasulfide (bis-sulfur silane). The associated studies on bis-sulfur silane treated AA 2024-T3 will be presented in the second part

  11. Corrosion protection of AA 2024-T3 by bis-[3-(triethoxysilyl)propyl]tetrasulfide in neutral sodium chloride solution. Part 1: corrosion of AA 2024-T3

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Danqing; Ooij, Wim J. van

    2003-10-01

    This study consists of two parts. In the first part, the corrosion of 2024-T3 aluminum alloy (AA 2024-T3) was studied using scanning electron microscopy and energy-dispersive X-ray spectroscopy. The results showed that the anodic S phase (Al{sub 2}CuMg) particles dealloyed Al and Mg during the 3.5 h of immersion in a neutral 0.6 M sodium chloride (NaCl) solution; with the dealloying of Mg being the most severe. Simultaneously, a heavy dissolution was also observed for the surrounding Al matrix of the S phase particles. This Al dissolution is likely to be caused by a local alkalization resulting from the coupled cathodic reaction (water and/or oxygen reduction). Such corrosion in AA 2024-T3, however, can be inhibited efficiently after the treatment of bis-[3-(triethoxysilyl)propyl]tetrasulfide (bis-sulfur silane). The associated studies on bis-sulfur silane treated AA 2024-T3 will be presented in the second part.

  12. Corrosion resistance of AA6063-Type Al-Mg-Si alloy by silicon carbide in sodium chloride solution for marine application

    Science.gov (United States)

    Fayomi, Ojo Sunday Isaac; Abdulwahab, Malik; Popoola, Abimbola Patricia Idowu; Asuke, Ferdinand

    2015-12-01

    The present work focused on corrosion inhibition of AA6063 type (Al-Mg-Si) alloy in sodium chloride (NaCl) solution with a silicon carbide inhibitor, using the potentiodynamic electrochemical method. The aluminium alloy surface morphology was examined, in the as-received and as-corroded in the un-inhibited state, with scanning electron microscopy equipped with energy dispersive spectroscopy (SEM-EDS). The results obtained via linear polarization indicated a high corrosion potential for the unprotected as-received alloy. Equally, inhibition efficiency as high as 98.82% at 10.0 g/v silicon carbide addition was obtained with increased polarization resistance ( R p), while the current density reduced significantly for inhibited samples compared to the un-inhibited aluminium alloy. The adsorption mechanism of the inhibitor aluminium alloy follows the Langmuir adsorption isotherm. This shows that the corrosion rate of aluminium alloy with silicon carbide in NaCl environment decreased significantly with addition of the inhibitor.

  13. 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. Fabrication and icing property of superhydrophilic and superhydrophobic aluminum surfaces derived from anodizing aluminum foil in a sodium chloride aqueous solution

    Science.gov (United States)

    Song, Meirong; Liu, Yuru; Cui, Shumin; Liu, Long; Yang, Min

    2013-10-01

    An aluminum foil with a rough surface was first prepared by anodic treatment in a neutral aqueous solution with the help of pitting corrosion of chlorides. First, the hydrophobic Al surface (contact angle around 79°) became superhydrophilic (contact angle smaller than 5°) after the anodizing process. Secondly, the superhydrophilic Al surface became superhydrophobic (contact angle larger than 150°) after being modified by oleic acid. Finally, the icing property of superhydrophilic, untreated, and superhydrophobic Al foils were investigated in a refrigerated cabinet at -12 °C. The mean total times to freeze a water droplet (6 μL) on the three foils were 17 s, 158 s and 1604 s, respectively. Thus, the superhydrophilic surface accelerates the icing process, while the superhydrophobic surface delays the process. The main reason for this transition might mainly result from the difference of the contact area of the water droplet with Al substrate: the increase in contact area with Al substrate will accelerate the heat conduct process, as well as the icing process; the decrease in contact area with Al substrate will delay the heat conduct process, as well as the icing process. Compared to the untreated Al foil, the contact area of the water droplet with the Al substrate was higher on superhydrophilic surface and smaller on the superhydrophobic surface, which led to the difference of the heat transfer time as well as the icing time.

  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. Totally solution-processed CuInS2 solar cells based on chloride inks: reduced metastable phases and improved current density

    Science.gov (United States)

    Dehghani, Mehdi; Behjat, Abbas; Tajabadi, Fariba; Taghavinia, Nima

    2015-03-01

    Planar superstrate CuInS2 (CIS) solar cell devices are fabricated using totally solution-processed deposition methods. These Cd-free devices are structured by FTO/TiO2/In2S3/CIS/carbon, where TiO2 and In2S3 are deposited by spray pyrolysis, and a CIS film is deposited using spin-coating followed by annealing at 250 °C. The pasted carbon layer is utilized as the anode. No further sulfurization or selenization is employed. The Cu/In ratio in the ink is found as a critical factor affecting the morphology and crystallinity of the film as well as the photovoltaic performance of the device. An optimum Cu/In = 1.05 results in large-grain films with sharp diffraction peaks and, subsequently, optimal series resistance and shunt conductance. It is also found that the chloride-based ink results in CIS films with considerably reduced metastable phases, compared to the conventional acetate-based inks. A current density of 23.6 mA cm-2 is obtained for the best devices, leading to a conversion efficiency of 4.1%.

  17. Solubility and physic-chemical properties of NaH2PO4 in phosphoric acid, sodium chloride and their mixture solutions at T = (298.15 and 313.15) K

    International Nuclear Information System (INIS)

    Highlights: • Solubility and physic-chemical properties of NaH2PO4 in H3PO4 solutions were obtained. • Solubility and physic-chemical properties of NaH2PO4 in NaCl solutions were obtained were obtained. • Solubility and physic-chemical properties of NaH2PO4 in mixed solutions of H3PO4 and NaCl were obtained. • The solubility diagrams and the physic-chemical property diagrams were plotted. - Abstract: In this study, solubility and physic-chemical properties of sodium dihydrogen phosphate in sodium chloride, phosphoric acid and their mixture solutions at T = (298.15 and 313.15) K have been investigated by using isothermal dissolution method. In the three systems, the solubility of NaH2PO4 always increases with the temperature increasing and decreases with molar concentration of phosphoric acid (sodium chloride) increasing because of the same ion effect. Solubility data of sodium dihydrogen phosphate in the mixed solution of sodium chloride and phosphoric acid is basically required for designing and optimizing the solvent extraction process in the industrial production

  18. 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)

  19. 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

  20. Effect of Chloride Type on Penetration of Chloride Ions in Concrete

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The influence of chloride type on the diffusivity of chloride ions in concrete was studied by experiment. The result shows that the glectric resistance of concrete and the chloride diffusion coefficient are influenced by chloride type. For the same water/cement ratio (W/C), the diffusion coefficient D in KCl solution is larger than that in NaCl solution; however, the concrete resistance in KCl solution is smaller than that in NaCl solution. The experimental result is analyzed with theory of diffusion.

  1. Factors influencing chloride deposition in a coastal hilly area and application to chloride deposition mapping

    OpenAIRE

    H. Guan; Love, A. J.; C. T. Simmons; Makhnin, O.; A. S. Kayaalp

    2010-01-01

    Chloride is commonly used as an environmental tracer for studying water flow and solute transport in the environment. It is especially useful for estimating groundwater recharge based on the commonly used chloride mass balance (CMB) method. Strong spatial variability in chloride deposition in coastal areas is one difficulty encountered in appropriately applying the method. A high-resolution bulk chloride deposition map in the coastal region is thus needed. The aim of this study is to construc...

  2. Factors influencing chloride deposition in a coastal hilly area and application to chloride deposition mapping

    OpenAIRE

    H. Guan; Love, A. J.; C. T. Simmons; Makhnin, O.; A. S. Kayaalp

    2010-01-01

    Chloride is commonly used as an environmental tracer for studying water flow and solute transport in the environment. It is especially useful for estimating groundwater recharge based on the commonly used chloride mass balance (CMB) method. Strong spatial variability in chloride deposition in coastal areas is one difficulty encountered in appropriately applying the method. A high-resolution bulk chloride deposition map in the coastal region is thus needed. The aim of this st...

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

    Science.gov (United States)

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

    1998-09-01

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

  4. 改进电热法测定氯化钠溶液比热容的研究%Study on Using Improved Electrothermal Method to Test Specific Heat Capacity of Sodium Chloride Solution

    Institute of Scientific and Technical Information of China (English)

    付睿丽; 马镛; 李磊; 吴修治

    2014-01-01

    改进电热法测定比热容装置,省去电流表,用阻值恒定的 FeCrAl 合金电阻丝代替,并且设置静音搅拌叶轮,实现溶液自动搅拌。为防止氯化钠溶液电解,用石墨电极代替传统铜电极,测出氯化钠溶液比热容随浓度的变化规律:即在初温相同的条件下,氯化钠溶液比热容随浓度增加而线性降低;随着初始温度的升高,氯化钠溶液比热容随浓度变化曲线整体向上平移。%The experimental device,by which the improved electrothermal method is used to test the specific heat capacity,may leave out an ammeter,and the ammeter can be replaced by the re-sistance wire of FeCrAl Alloy which has constant resistance.The device has mute stirring impel-ler,and can mix the solution automatically.In order to prevent the sodium chloride solution from being electrolysed,the traditional copper electrode is replaced by graphite electrode.Then,the variations of the specific heat capacity of sodium chloride solution with the temperature are test-ed.The results of the experiment indicate that the specific heat capacity of sodium chloride solu-tion decreases linearly along with the increase of concentration,and with the changes of the initial temperature,the curve offset slightly.

  5. Osmotic and activity coefficients in the binary solutions of 1-butyl-3-methylimidazolium chloride and bromide in methanol or ethanol at T = 298.15 K from isopiestic measurements

    International Nuclear Information System (INIS)

    Highlights: → The osmotic coefficients of the solutions of 1-butyl-3-methylimidazolium chloride and bromide in ethanol and methanol have been measured. → Measured osmotic coefficients were correlated using NRTL and Pitzer models. → Vapor pressures were evaluated from the correlated osmotic coefficients. → Model parameters have been interpreted in terms of ion-ion and ion-solvent interactions. - Abstract: Osmotic coefficients of the binary solutions of two room-temperature ionic liquids (1-butyl-3-methylimidazolium chloride and bromide) in methanol and ethanol have been measured at T = 298.15 K by the isopiestic method. The experimental osmotic coefficient data have been correlated using a forth-order polynomial in terms of (molality)0.5, with both, ion interaction model of Pitzer and electrolyte non-random two liquid (e-NRTL) model of Chen. The values of vapor pressures of above-mentioned solutions have been calculated from the osmotic coefficients. The model parameters fitted to the experimental osmotic coefficients have been used for prediction of the mean ionic activity coefficients of those ionic liquids in methanol and ethanol.

  6. Standard test methods for pitting and crevice corrosion resistance of stainless steels and related alloys by use of ferric Chloride solution

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2003-01-01

    1.1 These test methods cover procedures for the determination of the resistance of stainless steels and related alloys to pitting and crevice corrosion (see Terminology G 15) when exposed to oxidizing chloride environments. Six procedures are described and identified as Methods A, B, C, D, E, and F. 1.1.1 Method A—Ferric chloride pitting test. 1.1.2 Method B—Ferric chloride crevice test. 1.1.3 Method C—Critical pitting temperature test for nickel-base and chromium-bearing alloys. 1.1.4 Method D—Critical crevice temperature test for nickel-base and chromium-bearing alloys. 1.1.5 Method E—Critical pitting temperature test for stainless steels. 1.1.6 Method F—Critical crevice temperature test for stainless steels. 1.2 Method A is designed to determine the relative pitting resistance of stainless steels and nickel-base, chromium-bearing alloys, whereas Method B can be used for determining both the pitting and crevice corrosion resistance of these alloys. Methods C, D, E and F allow for a rankin...

  7. 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

  8. Diffusion behavior of chloride ions in concrete

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-06-01

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

  9. Physiochemical and spectroscopic behavior of actinides and lanthanides in solution, their sorption on minerals and their compounds formed with macromolecules; Comportamiento fisicoquimico y espectroscopico de actinidos y lantanidos en solucion, su sorcion sobre minerales y sus compuestos formados con macromoleculas

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez R, M., E-mail: melania.jimenez@inin.gob.m [ININ, Departamento de Quimica, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2010-07-01

    From the chemical view point, the light actinides has been those most studied; particularly the uranium, because is the primordial component of the nuclear reactors. The chemical behavior of these elements is not completely defined, since they can behave as transition metals or metals of internal transition, as they are the lanthanides. The actinides are radioactive; between them they are emitters of radiation alpha, highly toxic, of live half long and some very long, and artificial elements. For all this, to know them sometimes is preferable to use their chemical similarity with the lanthanides and to study these. In particular, the migration of emitters of radiation alpha to the environment has been studied taking as model the uranium. It is necessary to mention that actinides and lanthanides elements are in the radioactive wastes of the nuclear reactors. In the Chemistry Department of the Instituto Nacional de Investigaciones Nucleares (ININ) the researches about the actinides and lanthanides began in 1983 and, between that year and 1995 several works were published in this field. In 1993 the topic was proposed as a Department project and from then around of 13 institutional projects and managerial activity have been developed, besides 4 projects approved by the National Council of Science and Technology. The objective of the projects already developed and of the current they have been contributing knowledge for the understanding of the chemical behavior of the lanthanides and actinides, as much in solution as in the solid state, their behavior in the environment and the chemistry of their complexes with recurrent and lineal macromolecules. (Author)

  10. Approach to corrosion mechanisms for a carbon steel in a solution of sodium chloride at 3 pc and its inhibition by means of organic molecules. Compared benefit of the use of stationary and transient electrochemical methods

    International Nuclear Information System (INIS)

    Within the context of an increased use of seawater as coolant in various industrial installations, this research thesis had two main objectives: the search for inhibitor organic compounds with optimal efficiency, and a better understanding of the mechanisms of corrosion inhibition by the best compounds within the considered organic compounds. After having reported a bibliographical study on carbon steel corrosion in seawater or in a sodium chloride solution at 3 pc, and on the inhibition of this corrosion, the author presents the experimental conditions (materials and methods). He reports the use of stationary and un-stationary electrochemical methods for the study of the steel-solution interface without inhibitor in order to get a better knowledge of corrosion electrochemical processes and to determine more precisely the corrosion rate. The last part addresses the study of the same interface but in presence of various inhibitors

  11. Estimating the chloride transport in cement paste

    OpenAIRE

    Princigallo, A.

    2012-01-01

    A method was developed to measure the diffusion coefficient of chloride ions in cement paste based on an analytical solution to Fick’s 2nd law in a cylindrical coordinate system. This natural method yielded diffusivity results within as little as a month. Testing time was reduced by exploiting the three-dimensional inward flux in the specimen. In an attempt to determine the saturation concentration, dense portland cement pastes were exposed to a concentrated chloride solution. The method prov...

  12. Factors influencing chloride deposition in a coastal hilly area and application to chloride deposition mapping

    OpenAIRE

    H. Guan; Love, A. J.; C. T. Simmons; A. S. Kayaalp

    2009-01-01

    Chloride is commonly used as an environmental tracer for studying water flow and solute transport in the environment. It is especially useful for estimating groundwater recharge based on the commonly used chloride mass balance (CMB) method. Strong spatial variability in chloride deposition in coastal areas is one difficulty encountered in appropriately applying the CMB approach. Furthermore, intensive vegetation clearance for agriculture, for example during the European settlement in many...

  13. Amperometric Sensor for Detection of Chloride Ions

    OpenAIRE

    Rene Kizek; Petr Babula; Jaromir Hubalek; Vojtech Adam; Libuse Trnkova

    2008-01-01

    Chloride ion sensing is important in many fields such as clinical diagnosis, environmental monitoring and industrial applications. We have measured chloride ions at a carbon paste electrode (CPE) and at a CPE modified with solid AgNO3, a solution of AgNO3 and/or solid silver particles. Detection limits (3 S/N) for chloride ions were 100 μM, 100 μM and 10 μM for solid AgNO3, solution of AgNO3 and/or solid silver particles, respectively. The CPE modified with silver particles is the mo...

  14. Effect of sodium chloride on glassy and crystalline transitions of wheat starch treated with high hydrostatic pressure: Prediction of solute-induced barostability from nonmonotonic solute-induced thermostability

    Science.gov (United States)

    Wheat starch was high hydrostatic pressure (HHP)-treated in various sodium chloride (NaCl) concentrations (0 to near-saturation), in order to explore the effects of salt on glassy and crystalline transitions of starch during the treatment, using differential scanning calorimetry (DSC). For wheat st...

  15. Comportamiento viscoso de lubricantes e altas presiones

    OpenAIRE

    Paredes Méndez, Xavier

    2012-01-01

    Esta Tesis Doctoral se centra en el estudio del comportamiento viscoso a alta presión de diferentes lubricantes de tipo mineral, vegetal y sintético. Cinco líquidos analizados a lo largo de este trabajo pueden ser usados como materiales de referencia para la calibración de viscosímetros a presión: di (2-etilhexil) sebacato, di (2-etilhexil) ftalato, diisodecilftalato, escualano y dipentaeritritol hexaisononanoato. Además se estudian cinco bases sintéticas para sistemas de refrigeración con di...

  16. Comportamientos de ciudadanía organizacional

    OpenAIRE

    Omar, Alicia

    2013-01-01

    Los “Comportamientos de Ciudadanía Organizacional” (CCO se refieren a todas aquellas acciones discrecionales, que sobrepasan las expectativas formalmente requeridas para el desempeño de un determinado rol y que resultan beneficiosas para las organizaciones. Se manifiestan a través de un amplio rango de conductas altruistas o de cooperación, que no son directamente exigidas ni recompensadas, pero que contribuyen a generar relaciones interpersonales armoniosas en el lugar de trabajo. Para ser c...

  17. Estadística y comportamiento organizacional

    OpenAIRE

    Jorge Óscar Rouquette; Magdalena Saleme

    2000-01-01

    Como parte de una investigación, el articulo se centra en una aplicación estadística a un campo de estudio de la administración como es el comportamiento organizacional, concretamente en la aceptación rechazo de siete hipótesis de investigación que pretenden demostrar que existe relación entre la variable satisfacción en el trabajo y siete indicadores que, según lo propuesto por Locke, influyen o determinan el grado de satisfacción que perciben los trabajadores. Vara demostrar la dep...

  18. Crecimiento y comportamiento en la adolescencia.

    OpenAIRE

    José Luis Lillo Espinosa

    2004-01-01

    Se describen las características del crecimiento y comportamiento en la adolescencia, haciendo hincapié en sus tres características fundamentales: la adolescencia como duelo por el mundo infantil, como renovación de la problemática psíquica establecida en la infancia y su resolución y finalmente por ser una etapa llena de nuevas expectativas, ilusiones y descubrimientos vitales. Se analizan los significados de los cambios corporales en la configuración de la identidad definitiva como adulto. ...

  19. The passivation of calcite by acid mine water. Column experiments with ferric sulfate and ferric chloride solutions at pH 2

    International Nuclear Information System (INIS)

    Column experiments, simulating the behavior of passive treatment systems for acid mine drainage, have been performed. Acid solutions (HCl or H2SO4, pH 2), with initial concentrations of Fe(III) ranging from 250 to 1500 mg L-1, were injected into column reactors packed with calcite grains at a constant flow rate. The composition of the solutions was monitored during the experiments. At the end of the experiments (passivation of the columns), the composition and structure of the solids were measured. The dissolution of calcite in the columns caused an increase in pH and the release of Ca into the solution, leading to the precipitation of gypsum and Fe-oxyhydroxysulfates (Fe(III)-SO4-H+ solutions) or Fe-oxyhydroxychlorides (Fe(III)-Cl-H+ solutions). The columns worked as an efficient barrier for some time, increasing the pH of the circulating solutions from 2 to ∼6-7 and removing its metal content. However, after some time (several weeks, depending on the conditions), the columns became chemically inert. The results showed that passivation time increased with decreasing anion and metal content of the solutions. Gypsum was the phase responsible for the passivation of calcite in the experiments with Fe(III)-SO4-H+ solutions. Schwertmannite and goethite appeared as the Fe(III) secondary phases in those experiments. Akaganeite was the phase responsible for the passivation of the system in the experiments with Fe(III)-Cl-H+ solutions

  20. Use of a multi-species reactive transport model to simulate chloride ingress in mortar exposed to NaCl solution or sea-water

    DEFF Research Database (Denmark)

    Jensen, Mads Mønster; De Weerdt, K.; Johannesson, Björn;

    2015-01-01

    Simulations of ion ingress in Portland cement mortar using a multi-species reactive mass transport model are compared with experimental test results. The model is an extended version of the Poisson–Nernst–Planck equations, accounting for chemical equilibrium. Saturated mortar samples were exposed...... reactive mass transport model is shown by comparing the simulation and experimental results. The tortuosity factor used in the simulations is adjusted to obtain the best reproduction of the experimental results. The model predicts the total chloride content satisfactorily, despite assumptions in the...... simulation like fixed hydration degree over time. Improvements and suggestions for further development of the model are discussed, e.g. extended hydration description, improved overall chemical description and a more strict use of the tortuosity factor....

  1. 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.

  2. Actividad coordinada en el cerebro: Reflejo y determinante de comportamientos

    OpenAIRE

    Jose Luis Pérez Velázquez

    2009-01-01

    La actividad coordinada entre distintas áreas cerebrales determina cómo el cerebro procesa la información, y también el comportamiento individual. Sus alteraciones resultan en desviaciones del comportamiento. Específicamente, hay indicios de que los patrones de sincronización cortical son diferentes entre individuos con autismo comparados con no autistas.

  3. Thermodynamic properties of aqueous-alcoholic solutions of sodium chloride. H2O-2-C3H7OH-NaCl

    Science.gov (United States)

    Veryaeva, E. S.; Konstantinova, N. M.; Mamontov, M. N.; Uspenskaya, I. A.

    2010-11-01

    The temperature-concentration dependences of the NaCl activity coefficient in aqueous solutions of isopropanol (propanol-2) at temperatures of 298.15 and 323.15 K (solution ionic force, 0.01 to 3 m; alcohol content, 10-60 wt %) were determined through the electromotive force method with an ion-selective electrode. A Pitzer model was used to mathematically describe the thermodynamic properties. The integral Gibbs energy of the solution formation of the H2O-2-C3H7OH-NaCl ternary system was performed according to Darken's method. The dissociation degree of salt in the investigated solutions was estimated using the literature data on the association constant of NaCl in aqueous-isopropanol solution.

  4. Variaciones en el comportamiento electoral en Paraguay

    Directory of Open Access Journals (Sweden)

    Liliana DUARTE RECALDE

    2012-06-01

    Full Text Available El proceso electoral en Paraguay se ha visto condicionado históricamente por el control de la Asociación Nacional Republicana, partido hegemónico durante los años del régimen de Stroessner y los años de la transición democrática. Por este motivo, la alternancia al mando del Poder Ejecutivo ocurrida en el año 2008, como resultado del proceso electoral, marcó un hito en la historia política del país y resaltó la importancia del análisis del comportamiento electoral de los paraguayos, sus tendencias y los elementos coyunturales y estructurales que las condicionan. En el presente trabajo se describen los parámetros de comportamiento electoral en las tres últimas elecciones generales celebradas en el país considerando los índices de volatilidad electoral resultantes de estos comicios y los niveles de participación efectiva registrados, analizándolos a partir del contexto sociopolítico en que se desarrollan.

  5. Shelf life of unrefrigerated succinylcholine chloride injection.

    Science.gov (United States)

    Boehm, J J; Dutton, D M; Poust, R I

    1984-02-01

    The shelf life of succinylcholine chloride injection at several pH values when stored at room temperature was evaluated. Solutions containing 20 mg/ml of succinylcholine chloride were stored at 25 and 40 degrees C. The reaction was studied at pH values ranging from 3.0 to 4.5. At two-week intervals, the solutions were assayed by high-pressure liquid chromatography. The initial amount of succinylcholine chloride in all samples was 100.1 +/- 2.37% of label claim. Hydrolysis of succinylcholine chloride in unbuffered solutions followed apparent zero-order kinetics. The pH range of maximum stability was found to be from 3.75 to 4.50. Succinylcholine chloride decomposed at a considerably higher rate at 40 degrees C. Allowing for the effects of pH adjustment during manufacture and degradation during shipping, losses of 7.0% and 9.0% potency can be expected after storage at 25 degrees C for four and six weeks, respectively. Succinylcholine Chloride Injection, USP, should be stored in the refrigerator; if unbuffered succinylcholine chloride injection complying with USP pH limits must be stored at room temperature, it should not be kept for longer than four weeks. PMID:6702837

  6. Factors influencing chloride deposition in a coastal hilly area and application to chloride deposition mapping

    Directory of Open Access Journals (Sweden)

    H. Guan

    2010-05-01

    Full Text Available Chloride is commonly used as an environmental tracer for studying water flow and solute transport in the environment. It is especially useful for estimating groundwater recharge based on the commonly used chloride mass balance (CMB method. Strong spatial variability in chloride deposition in coastal areas is one difficulty encountered in appropriately applying the method. A high-resolution bulk chloride deposition map in the coastal region is thus needed. The aim of this study is to construct a chloride deposition map in the Mount Lofty Ranges (MLR, a coastal hilly area of approximately 9000 km2 spatial extent in South Australia. We examined geographic (related to coastal distance, orographic, and atmospheric factors that may influence chloride deposition, using partial correlation and regression analyses. The results indicate that coastal distance, elevation, as well as terrain aspect and slope, appear to be significant factors controlling chloride deposition in the study area. Coastal distance accounts for 70% of spatial variability in bulk chloride deposition, with elevation, terrain aspect and slope an additional 15%. The results are incorporated into a de-trended residual kriging model (ASOADeK to produce a 1 km×1 km resolution bulk chloride deposition and concentration maps. The average uncertainty of the deposition map is about 20–30% in the western MLR, and 40–50% in the eastern MLR. The maps will form a useful basis for examining catchment chloride balance for the CMB application in the study area.

  7. Study on Preparation of Manganous-Manganic Oxide from Purified Manganese Chloride Solution%氯化锰溶液生产高品质四氧化三锰粉体的研究

    Institute of Scientific and Technical Information of China (English)

    王玉华; 张立岩; 张彦儒

    2013-01-01

    采用N235萃取提纯的氯化锰溶液制备高品质四氧化三锰.结果表明,最佳条件为:反应温度60℃、搅拌速度500 r/min、氯化铵用量2 g/L、溶液锰浓度20 g/L、pH7.5、溶液流速3 L/h、氧化时间6h.制备出的四氧化三锰粒度集中,比表面较大,钙、镁等达到国内电子级产品先进水平,杂质铁、硒、铬含量远低于国内同类产品.%High quality manganous-manganic oxide (Mn3O4) was prepared from manganese chloride solution purified with N235 extraction. The results show that the optimum conditions include reaction temperature of 60 ℃ , stirring speed of 500 r/min, dosage of ammonium chloride of 2 g/L, manganese concentration of 20 g/L, pH = 7. 5, solution flow rate of 3 L/h, and oxidation time of 6 h. The prepared Mn3O4 reaches the advanced level of domestic electronic grade with concentrated grain size, larger specific surface area and lower content of calcium and magnesium. The impurity contents (iron, selenium, chromium) are far below those of the counterpart in domestic market.

  8. Anodic dissolution mwchanisms of copper in neutral carbonate-chloride solution. Tansan en oyobi enkabutsu yoeki chu ni okeru do no anodo yokai. Chusei yoeki chu ni okeru yokai kiko

    Energy Technology Data Exchange (ETDEWEB)

    Nishikata, Atsushi; Tsuru, Toru; Itagaki, Masayuki; Haruyama, Shiro; Fujii, Eiichiro (Tokyo Inst. of Technology, Faculty of Engineering, Tokyo (Japan) Tokyo Inst. of Technology, Tokyo (Japan) Tokyo National College of Technology, Tokyo (Japan) Toshiba Corp., Kawasaki (Japan))

    1990-01-15

    In this study, anodic polarization curves of copper in neutral solutions containing CO {sup 2 {minus}} {sub 3} and Cl {sup {minus}} ions were measured by the stationary solution and channel flow electrode method, the anodic dissolution mechanism of copper was studied and the effects of concentration of carbonate and chloride were investigated. As a result, the following was found: (1) Concerning the anodic polarization curves of copper, the oxidation region I toward univalent and the oxidation region II toward divalent appeared continuously like in the alkaline solution and a clear Tarfel relationship was obtained respectively. It was revealed that in both the oxidation region toward univalent and the oxidation region toward divalent, the eletric current relied only on the Cl sup - concentration and did not rely on PH and CO {sup 2 {minus}} {sub 3} concentrations. (2) Based on PH, CO {sup 2 {minus}} {sub 3} and Cl {sup {minus}} concentration dependability and the result of elused ionic species obtained by the channel flow electrode method, the reaction mechanism in the respective regions were clarified. 5 refs, 4 figs, 1 tab.

  9. The solubility of UO22+ in dilute sodium chloride solutions and in high-ionic strength sodium sulfate and chlorine brines

    International Nuclear Information System (INIS)

    Uranium is a major component of high-level nuclear waste. In an oxidizing environment, UO22+ would be expected to be the dominant dissolved species in solution. In addition to dilute solutions, because high-level nuclear waste may be stored in repositories containing salt, it is important to characterize the aqueous chemistry of UO22+ and the solubility-controlling U(VI) solids in high-ionic strength brines as a function of pH. We have studied the solubility of UO22+ by precipitation of solid phase in 0.001 molal NaCl, 5.2 molal NaCl, and saturated Na2SO4 at pH values ranging from 5 to 12. The solution concentrations were measured by alpha particle liquid scintillation counting. The precipitated solids were characterized by powder x-ray diffraction, electron microscopy, infrared spectroscopy, and x-ray photoelectron spectroscopy

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

    International Nuclear Information System (INIS)

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

  11. Chloride Transport in Undersea Concrete Tunnel

    Directory of Open Access Journals (Sweden)

    Yuanzhu Zhang

    2016-01-01

    Full Text Available Based on water penetration in unsaturated concrete of underwater tunnel, a diffusion-advection theoretical model of chloride in undersea concrete tunnel was proposed. The basic parameters including porosity, saturated hydraulic conductivity, chloride diffusion coefficient, initial water saturation, and moisture retention function of concrete specimens with two water-binder ratios were determined through lab-scale experiments. The variation of chloride concentration with pressuring time, location, solution concentration, initial saturation, hydraulic pressure, and water-binder ratio was investigated through chloride transport tests under external water pressure. In addition, the change and distribution of chloride concentration of isothermal horizontal flow were numerically analyzed using TOUGH2 software. The results show that chloride transport in unsaturated concrete under external water pressure is a combined effect of diffusion and advection instead of diffusion. Chloride concentration increased with increasing solution concentration for diffusion and increased with an increase in water pressure and a decrease in initial saturation for advection. The dominant driving force converted with time and saturation. When predicting the service life of undersea concrete tunnel, it is suggested that advection is taken into consideration; otherwise the durability tends to be unsafe.

  12. Comportamiento del los aplacados de piedra reforzados

    Directory of Open Access Journals (Sweden)

    Vera Soriano, Roberto

    2003-04-01

    Full Text Available The improvement of the mechanical performance Bateig Novelda stone coatings anchored in back-ventilated facades has been studied after being reinforced with glass fiber frames adhered with epoxy resin.Esta trabajo presenta el resultado de la investigación llevada a cabo por un grupo del Departamento de Construcciones Arquitectónicas de la Escuela de Arquitectura de Alicante en colaboración con la industria de la piedra aplicada a la construcción. El trabajo muestra el comportamiento mecánico de las placas de piedra Bateig de Novelda, empleadas en fachadas ventiladas, reforzadas con fibra de vidrio adherida con resina epoxi.

  13. Crecimiento y comportamiento en la adolescencia.

    Directory of Open Access Journals (Sweden)

    José Luis Lillo Espinosa

    2004-01-01

    Full Text Available Se describen las características del crecimiento y comportamiento en la adolescencia, haciendo hincapié en sus tres características fundamentales: la adolescencia como duelo por el mundo infantil, como renovación de la problemática psíquica establecida en la infancia y su resolución y finalmente por ser una etapa llena de nuevas expectativas, ilusiones y descubrimientos vitales. Se analizan los significados de los cambios corporales en la configuración de la identidad definitiva como adulto. Se detallan las tendencias o movimientos emocionales que están presentes en la adolescencia, tanto los regresivos como los progresivos.

  14. The measurement and prediction of the corrosion potential of copper in chloride solutions as a function of oxygen concentration and mass-transfer coefficient

    International Nuclear Information System (INIS)

    Steady-state corrosion potentials of copper in O2-containing NaC1 solution have been measured using three types of electrode: a rotating-disc electrode, an electrode covered by a porous nylon membrane and an electrode covered by a layer of compacted Na-bentonite clay. Mass-transfer coefficients for these electrodes vary from 10-2 cm s-1 in hulk solution to 10-7 cm s-1 for the clay-covered electrode. Solutions were equilibrated with atmospheres of air, 2% O2/N2, 0.2% O2 N2, or were nominally deaerated. In aerated bulk solution, the anodic reaction is mass-transfer limited and the cathodic reaction is kinetically controlled. With decreasing [O2], the cathodic reaction becomes partially mass-transfer limited. Both reactions are essentially mass-transfer controlled for the membrane- and clay-covered electrodes. A mixed-potential model is developed for predicting ECorr over a wide range of mass-transfer conditions and [O2], under circumstances where either reaction may be under joint kinetic/mass-transfer control. (author)

  15. The electrochemical behaviour of 2205 duplex stainless steel in alkaline solutions with different pH in the presence of chloride

    International Nuclear Information System (INIS)

    Highlights: ► The pH plays important roles in 2205 DSS passive film composition and occurrence of pitting. ► The passive film of 2205 DSS in the alkaline solution, presenting a bilayer structure, composed of an outer and inner layer. ► As the pH increases, there is a gradual enrichment in chromium and nitrogen in the surface film. ► The peak of NH3/NH4+ is disappeared in the pH 10.5 solutions. ► The pit initiated at inclusions or in austenite phase near the γ/δ boundaries. - Abstract: The electrochemical behaviour of 2205 duplex stainless steel in alkaline solutions with different pH values in the presence of NaCl was evaluated by different techniques: potentiodynamic measurements, electrochemical impedance spectroscopy and capacitance measurements (Mott–Schottky approach). The chemical composition was studied by X-ray photoelectron spectroscopy (XPS). In addition, the site of pitting nucleated preferentially on the duplex stainless steel had been confirmed by scanning electron microscopy (SEM). The results indicated that both the pH and immersion time play important roles in the evolution of the film resistance, charge transfer processes and the occurrence of pitting. The composition of the surface film changes with the pH value. The film formed in the alkaline solution, presenting a bilayer structure, predominantly contained Fe species and Cr-oxide. The NH3/NH4+ species in the passive film are disappeared in the pH 10.5 solution. The pit initiation sites occurred in austenite phase near the γ/δ boundaries or at inclusions. The number and size of the pits increases with the decrease of pH value after long time immersion.

  16. Effects of 5-(3-aminophenyl)-tetrazole on the inhibition of unalloyed iron corrosion in aerated 3.5% sodium chloride solutions as a corrosion inhibitor

    Energy Technology Data Exchange (ETDEWEB)

    Sherif, El-Sayed M., E-mail: esherif@ksu.edu.sa [Center of Excellence for Research in Engineering Materials (CEREM), College of Engineering, King Saud University, P.O. Box 800, Al-Riyadh 11421 (Saudi Arabia)

    2011-10-03

    Highlights: {yields} 5-(3-Aminophenyl)-tetrazole (APT) is a good inhibitor for iron in NaCl solution. {yields} The presence of APT and increasing its content decrease the corrosion parameters. {yields} The inhibition of iron is achieved by the adsorption of APT onto the metal surface. {yields} Increasing immersion time of iron enhances the inhibition efficiency (IE%) of APT. {yields} The IE of 5 mM APT exceeded 90% after 12 h of iron immersion in Cl solutions. - Abstract: The effects of 5-(3-aminophenyl)-tetrazole (APT) on the inhibition of unalloyed iron corrosion in aerated 3.5% NaCl solutions as a corrosion inhibitor have been studied using open circuit potential (OCP), cyclic potentiodynamic polarization (CPP), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS) measurements. The inhibited iron surface was characterized by scanning electron spectroscopy (SEM) and energy dispersive X-ray (EDS) investigations. The OCP showed positive shifts of potential in the presence of APT and the increase of its concentration. CPP and CA measurements indicated that APT molecules decrease the pitting and uniform corrosions through decreasing the pitting and absolute currents, and corrosion rate as well as shifting the corrosion and pitting potentials of iron towards the noble values. EIS plots revealed that APT increases the surface and polarization resistances of iron. SEM/EDS investigations proved that the inhibition of iron corrosion in NaCl containing APT solutions is achieved by the adsorption of APT molecules onto iron to preclude the dissolution process by blocking the active sites on its surface.

  17. Effects of 5-(3-aminophenyl)-tetrazole on the inhibition of unalloyed iron corrosion in aerated 3.5% sodium chloride solutions as a corrosion inhibitor

    International Nuclear Information System (INIS)

    Highlights: → 5-(3-Aminophenyl)-tetrazole (APT) is a good inhibitor for iron in NaCl solution. → The presence of APT and increasing its content decrease the corrosion parameters. → The inhibition of iron is achieved by the adsorption of APT onto the metal surface. → Increasing immersion time of iron enhances the inhibition efficiency (IE%) of APT. → The IE of 5 mM APT exceeded 90% after 12 h of iron immersion in Cl solutions. - Abstract: The effects of 5-(3-aminophenyl)-tetrazole (APT) on the inhibition of unalloyed iron corrosion in aerated 3.5% NaCl solutions as a corrosion inhibitor have been studied using open circuit potential (OCP), cyclic potentiodynamic polarization (CPP), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS) measurements. The inhibited iron surface was characterized by scanning electron spectroscopy (SEM) and energy dispersive X-ray (EDS) investigations. The OCP showed positive shifts of potential in the presence of APT and the increase of its concentration. CPP and CA measurements indicated that APT molecules decrease the pitting and uniform corrosions through decreasing the pitting and absolute currents, and corrosion rate as well as shifting the corrosion and pitting potentials of iron towards the noble values. EIS plots revealed that APT increases the surface and polarization resistances of iron. SEM/EDS investigations proved that the inhibition of iron corrosion in NaCl containing APT solutions is achieved by the adsorption of APT molecules onto iron to preclude the dissolution process by blocking the active sites on its surface.

  18. Experimental determination and chemical modelling of radiolytic processes at the spent fuel/water interface. Experiments carried out in carbonate solutions in absence and presence of chloride

    Energy Technology Data Exchange (ETDEWEB)

    Bruno, Jordi; Cera, Esther; Grive, Mireia; Duro, Lara [Enviros Spain SL (Spain); Eriksen, Trygve [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Nuclear Chemistry

    2003-01-01

    We report on the recent experimental and modelling results of a research programme that started in 1995. The aim has been to understand the kinetic and thermodynamic processes that control the radiolytic generation of oxidants and reductants at the spent fuel water interface and their consequences for spent fuel matrix stability and radionuclide release. This has been done by carrying out well-controlled dissolution experiments of PWR Ringhals spent fuel fragments in an initially anoxic closed system and by using different solution compositions. Experimental series started with several tests carried out with deionised water as solvent, in a second phase experiments were conducted with 10 mM bicarbonate solutions. New experimental series were set up during the last two years by using the same bicarbonate content in solutions with varying NaCl concentrations in order to ascertain the role of this ligand on the radiolytic products and its consequence for radionuclide release. The selected NaCl concentrations are in the range of 0.1 to 10 mM. Experimental data shows that uranium dissolution at early contact times is controlled by the oxidation of the UO{sub 2} matrix. This process controls the co-dissolution of most of the analysed radionuclides, including Sr, Mo, Tc, Np and surprisingly enough, Cs. In the overall the release rates for U and the matrix associated radionuclides are in the range of 10{sup -6} moles/day with a clear decreasing trend with exposure time and after 2 years the initial release rates have decreased down to 3x10{sup -8} moles/day. The solubility of the released actinides appears to be limited by the formation of An(IV) hydroxide phases, although Np concentrations in solution did not reach solubility levels during the time intervals of the present tests. No secondary solid phase appears to control the solubility of the rest of the elements.

  19. Experimental determination and chemical modelling of radiolytic processes at the spent fuel/water interface. Experiments carried out in carbonate solutions in absence and presence of chloride

    International Nuclear Information System (INIS)

    We report on the recent experimental and modelling results of a research programme that started in 1995. The aim has been to understand the kinetic and thermodynamic processes that control the radiolytic generation of oxidants and reductants at the spent fuel water interface and their consequences for spent fuel matrix stability and radionuclide release. This has been done by carrying out well-controlled dissolution experiments of PWR Ringhals spent fuel fragments in an initially anoxic closed system and by using different solution compositions. Experimental series started with several tests carried out with deionised water as solvent, in a second phase experiments were conducted with 10 mM bicarbonate solutions. New experimental series were set up during the last two years by using the same bicarbonate content in solutions with varying NaCl concentrations in order to ascertain the role of this ligand on the radiolytic products and its consequence for radionuclide release. The selected NaCl concentrations are in the range of 0.1 to 10 mM. Experimental data shows that uranium dissolution at early contact times is controlled by the oxidation of the UO2 matrix. This process controls the co-dissolution of most of the analysed radionuclides, including Sr, Mo, Tc, Np and surprisingly enough, Cs. In the overall the release rates for U and the matrix associated radionuclides are in the range of 10-6 moles/day with a clear decreasing trend with exposure time and after 2 years the initial release rates have decreased down to 3x10-8 moles/day. The solubility of the released actinides appears to be limited by the formation of An(IV) hydroxide phases, although Np concentrations in solution did not reach solubility levels during the time intervals of the present tests. No secondary solid phase appears to control the solubility of the rest of the elements

  20. Chloride induced localized corrosion in simulated concrete pore solution: effect of a phosphate-based inhibitor on the behavior of 304L stainless steel compared to carbon steel

    International Nuclear Information System (INIS)

    In this paper, the acoustic emission technique coupled with electrochemical measurements was used to determine, in simulated concrete pore solution (Ca(OH)2), the critical value [Cl-] / [OH-], which prevents the pitting corrosion initiation of AISI 304L austenitic stainless steel, and to compare this critical value with that of the carbon steel in the same medium with and without inhibitor Na3PO4. The results show that for the austenitic stainless steel, the critical threshold of pitting corrosion initiation is around 5, while for carbon steel without inhibitor in Ca(OH)2 solution, it has a low value of about 0.6. However, the presence of the inhibitor Na3PO4 in this solution leads to the formation of a protective phosphate layer on the steel surface, increasing the critical ratio [Cl-] / [OH-] from 0.6 to 15. Under these conditions, the corrosion behavior of carbon steel is improved and, thanks to the blocking of pitting sites by the Na3PO4 inhibitor, it becomes much more resistant to localized corrosion than AISI 304L austenitic steel. (authors)

  1. Corrosion resistance of Fe80B13.5Si4.5C2 metallic glass in sulphate and chloride solutions

    International Nuclear Information System (INIS)

    Metallic glasses, widely used because of their characteristic internal structure and properties are the subject of many research papers, both theoretical and practical. The present study analyses corrosion of the metallic glass Fe80B13.5Si4.5C2 in neutral and acidic solutions. At ambient temperature the material in the for of tape segments was etched for 4 and ca 20 h in neutral mediums, in which the corrosion rate is not high. Two series of measurements, respectively, were carried out in acidic mediums (in which the corrosion rate - Vcorr was considerable) for shorter periods of time - 1h and 2 h or 4 h. The metallic glass corrosion rate was determined using the gravimetric method, at the same time the dissolution rate was Vdiss.Fe determined for the main component of the alloy - i.e. iron. Visual observations both sides of the tape surface (dull and shiny) were carried out using the optic microscope; additionally, X-ray microanalysis were carried out using the scanning microscope. The data concerning the corrosion rate point to the fact that in neutral solutions the corrosion process is accompanied by the generation of sparingly soluble corrosion products. The accumulation of coloidal gels on the material surface is greater in 5% Na2SO4 solution than in 5% NaCl solution. It is connected both with the corrosion rate and its change in time in either medium. In acidic mediums the corrosion process is not accompanied by the generation of insoluble products. The corrosion rate is high, it is a few times higher in H2SO4 solutions than in HCl, where a study corrosion process can be observed. The measurements of iron dissolution rate show that at slow corrosion rate for metallic glass, the percentage of iron in the total mass decrease is lower than the nominal one. It can be accounted for by the fact that the outer layers of the material are enriched by the light components of the alloy. At the same time, during long-time etching at a slow corrosion rate the lowered

  2. Chloride ingress prediction

    DEFF Research Database (Denmark)

    Frederiksen, Jens Mejer; Geiker, Mette Rica

    Prediction of chloride ingress into concrete is an important part of durability design of reinforced concrete structures exposed to chloride containing environment. This paper presents the state-of-the art: an analytical model which describes chloride profiles in concrete as function of depth and...... makes physical sense for the design engineer, i.e. the achieved chloride diffusion coefficients at 1 year and 100 years, D1 and D100 respectively, and the corresponding achieved chloride concentrations at the exposed concrete surface, C1 and C100. Data from field exposure supports the assumption of time...... dependent surface chloride concentrations and the diffusion coefficients. Model parameters for Portland cement concretes with and without silica fume and fly ash in marine atmospheric and submerged South Scandinavian environment are suggested in a companion paper based on 10 years field exposure data....

  3. Actitudes hacia comportamientos protectores y de riesgo en conductores costarricenses

    Directory of Open Access Journals (Sweden)

    Marjorie Moreno Salas

    2011-12-01

    Full Text Available En el presente estudio se exploraron las actitudes y los comportamientos protectores y de riesgo al conducir vehículos particulares en una muestra de 590 conductores de entre 20 y 60 años (M = 38,57, DE =11,69 residentes del área metropolitana costarricense. Se realizó una investigación exploratoria, desarrollada mediante un diseño transversal con un cuestionario autoaplicado. Los principales resultados fueron que: A mayor cantidad de hijos e hijas dependientes, menores comportamientos y actitudes hacia el riesgo y mayores comportamientos protectores. A mayor cantidad de años de tener licencia, menores actitudes hacia el exceso de velocidad y menores comportamientos de riesgo asociados con la alta velocidad. Entre más días de manejo, mayores comportamientos protectores. A mayor reporte de actitudes y comportamientos favorables hacia el riesgo, menor edad de los participantes. A manera de conclusión, las actitudes y los comportamientos de riesgo se vinculan negativamente. Además, variables sociodemográficas como el número de hijos y la edad de los conductores modula la respuesta en cuanto a las actitudes y los comportamientos protectores y de riesgo al manejar. Los resultados del estudio forman un primer aporte a la investigación nacional en el tema, en tanto, se cuenta con un instrumento susceptible de ser aplicado en otros estudios y múltiples datos empíricos en la temática.

  4. Chloride ingress prediction

    DEFF Research Database (Denmark)

    Frederiksen, Jens Mejer; Geiker, Mette Rica

    Prediction of chloride ingress into concrete is an important part of durability design of reinforced concrete structures exposed to chloride containing environment. This paper presents experimentally based design parameters for Portland cement concretes with and without silica fume and fly ash in...... marine atmospheric and submersed South Scandinavian environment. The design parameters are based on sequential measurements of 86 chloride profiles taken over ten years from 13 different types of concrete. The design parameters provide the input for an analytical model for chloride profiles as function...

  5. Corrosion characteristics of Al-Si-Mg/SiC{sub p} composites with varying Si/Mg molar ratio in neutral chloride solutions

    Energy Technology Data Exchange (ETDEWEB)

    Escalera-Lozano, R.; Pech-Canul, M.I. [Cinvestav Saltillo (Mexico); Pech-Canul, M.A.; Quintana, P. [Departamento de Fisica Aplicada, Merida, Yuc. (Mexico)

    2009-09-15

    The corrosion resistance of Al-Mg-Si/SiC{sub p} composites produced by the pressureless infiltration method [using SiC{sub p} preforms with 50% porosity containing rice hull ash (RHA) and four custom-made alloys with varying Si/Mg molar ratio] was evaluated in neutral 0.1 M NaCl solutions. The deleterious phase Al{sub 4}C{sub 3} was successfully suppressed in composites with Si/Mg molar ratios of 0.89 and 1.05, but not in those with lower Si/Mg molar ratios (0.12 and 0.49). Results of cyclic polarizations in deareated 0.1 M NaCl solutions showed that with increasing Si/Mg molar ratio, passive current density increased but pitting susceptibility decreased both for reinforced and unreinforced alloys. Immersion tests in aerated 0.1 M NaCl showed that for composites with Si/Mg molar ratios of 0.12 and 0.49 chemical degradation by hydrolysis of Al{sub 4}C{sub 3} was followed by intense anodic dissolution at the matrix-reinforcement interface, while composites corresponding to Si/Mg molar ratios of 0.89 and 1.05 did not exhibit intense localized attack. Possible reasons for the improvement in resistance to localized corrosion are discussed. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  6. Hydroxyethyl cellulose as efficient organic inhibitor of zinc-carbon battery corrosion in ammonium chloride solution: Electrochemical and surface morphology studies

    Science.gov (United States)

    Deyab, M. A.

    2015-04-01

    Hydroxyethyl cellulose (HEC) has been investigated as corrosion inhibitor for zinc-carbon battery by polarization and electrochemical impedance spectroscopy (EIS) measurements. The obtained results show that the maximum inhibition efficiency by HEC in 26% NH4Cl solution at 300 ppm and 298 K is 92.07%. Tafel polarization studies reveal that HEC acts as an efficient mixed inhibitor. The corrosion rate is suppressed by the adsorption of HEC on the zinc surface. HEC adsorption obeys the Langmuir isotherm and the thermodynamic parameters Kads and Δ Gadso have been also calculated and discussed. Both physisorption and chemisorption may occur on the zinc surface. Surface characterization investigation using Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) is used to ascertain the nature of the protective film.

  7. Nano-pit corrosion of the tabs in aluminum electrolytic capacitor: Polarization characteristics of the tabs in ethyleneglycol-borate solution with chloride ions

    Energy Technology Data Exchange (ETDEWEB)

    Xue Rong; Qian Yuanyuan; Liu Keke; Jiang Xiaoxing; Zhu Junjie [Key Lab of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093 (China); Zhang Jianrong [Key Lab of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093 (China)], E-mail: jrzhang@nju.edu.cn

    2008-10-15

    To evaluate the corrosion behavior of the anode tab in aluminum electrolytic capacitor, we performed some electrochemical and morphology analysis using the polarization curves in conjunction with atomic force microscope (AFM), scanning electronic microscope (SEM) and optical microscope (OM). The results suggest that the current oscillation was found to be associated with nano-pit, which is defined as the rectangular pit ({beta}) with a depth less than 55 nm and a width no more than 100 nm. Furthermore, elevation of Cl{sup -} concentration widened the crevices caused by electrolytic tension, enlarged the nano-pit area, and accelerated the electrochemical reaction rate of the anode tab in ethyleneglycol-borate solution. These findings may have implications for the failure of aluminum electrolytic capacitor.

  8. Estadística y comportamiento organizacional

    Directory of Open Access Journals (Sweden)

    Jorge Óscar Rouquette

    2000-01-01

    Full Text Available Como parte de una investigación, el articulo se centra en una aplicación estadística a un campo de estudio de la administración como es el comportamiento organizacional, concretamente en la aceptación rechazo de siete hipótesis de investigación que pretenden demostrar que existe relación entre la variable satisfacción en el trabajo y siete indicadores que, según lo propuesto por Locke, influyen o determinan el grado de satisfacción que perciben los trabajadores. Vara demostrar la dependencia entre las variables estas hipótesis se utiliza la prueba Ji-cuadrada, y una vez que se demuestra que existe relación entre ellas se analiza el grado de intensidad de las relaciones encontradas a través del análisis de proporciones y el análisis residual.

  9. Emociones y comportamiento pro-ambiental

    Directory of Open Access Journals (Sweden)

    Mar Durán

    2007-01-01

    Full Text Available Basándonos en los trabajos de Fishbein y Ajzen (1975, 1980, Ajzen y Madden, (1986, Ajzen, (2002, este trabajo propone una extensión del modelo de la Teoría de la Conducta Planificada (TCP para poder explicar mejor el comportamiento pro-ambiental. El objetivo fundamental de este trabajo es explorar la importancia de los aspectos emocionales a la hora de comprender y explicar la conducta de reducir la utilización del coche más allá de la explicación dada por la TCP. Así, se construyó un cuestionario que se aplicó a una muestra de 797 representativa de la población gallega. Los resultados muestran a la ira como una de las variables que contribuyen a la explicación de esa conducta siendo su peso incluso superior a uno de los elementos centrales del modelo de la TCP, como es el control conductual.

  10. GENÉTICA DEL COMPORTAMIENTO: ABEJAS, un ejemplo.

    Directory of Open Access Journals (Sweden)

    Nates Parra Guiomar

    2011-12-01

    Full Text Available El concepto de que el comportamiento de los animales esta determinado genéticamente no es nuevo si se considera que ya Darwin en su famosa obra El origen del hombre, en 1871 mencionaba que… “los rasgos del temperamento de los animales son heredados”. Pero solo hasta hace casi 50 años fue que la genética del comportamiento surgió como una especialidad importante dentro de la Genética; desde esa época muchos son los avances que refuerzan la idea generalmente aceptada de que todos los patrones comportamentales están determinados por componentes tanto ambientales como genotípicos. El análisis del control genético de un determinado comportamiento es complicado por el hecho de que las acciones primarias de un gene pueden afectar: 1. Los órganos sensoriales, cambiando la información recibida. 2. Sistemas intermedios (nervioso, endocrino, alterando capacidades de coordinación y percepción y 3. Órganos efectores, alterando la respuesta. Las mutaciones inducidas, que bloquean o alteran los patrones normales de comportamiento, proporcionan una herramienta muy útil para entender como los genes influencian la conducta (Hall et al, 1982. Al respecto hay muchos ejemplos, cuyo conocimiento ha servido para controlar o seleccionar caracteres indeseables o deseables (respectivamente, importantes para el mejoramiento en algunas especies animales. Por ejemplo, con la llegada de la abeja africanizada a América del Sur (Brasil,1958 (Kerr, 1967 llegaron también varios inconvenientes generados por el fuerte comportamiento defensivo de la nueva subespecie introducida (Apis mellifera scutellata , lo cual hizo que se iniciaran programas de investigación tendientes a conocer la biología y el comportamiento de la nueva especie introducida, de manera que se pudieran establecer cepas de abejas menos defensivas, conjuntamente con otras características como productividad o comportamiento higiénico. El establecimiento de las bases

  11. Chloride ingress prediction

    DEFF Research Database (Denmark)

    Frederiksen, Jens Mejer; Geiker, Mette Rica

    2008-01-01

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

  12. Investigating and Modeling the Thermo-dynamic Impact of Electrolyte Solutions of Sodium Chloride and Sodium Sulfate on Prevention of the Formation of Methane Hydrate

    Directory of Open Access Journals (Sweden)

    M. Manteghian

    2013-07-01

    Full Text Available Devising methods to prevent hydrate formation is of the important issues in natural gas industry. Since a great deal of money is annually spent on using hydrate inhibitors, identification of new inhibitors with higher degrees of efficacy is economically justifiable. Bearing in mind the significant role of hydrate inhibitors in prevention of natural gas pipelines’ getting blocked, the present study attempts to investigate two compounds of NaCl and Na2SO4 as inhibitors of hydrate methane’s formation so as to respond to “what is the inhibitive thermo-dynamic impact of electrolyte compounds of NaCl and Na2SO4 on the formation of methane hydrate?” To do so, this study not only measures the equilibrium temperature and pressure of methane hydrate formation in the presence of electrolyte solutions of NaCl and Na2SO4 and compares the results obtained with the state lacking such inhibitors, but it also assesses the regression and mathematical modeling are utilized within a basic virtual environment in order to propose a model for prediction of thermo-dynamic equilibrium temperature and pressure of methane hydrate formation.

  13. The effect of YCl3 and LaCl3 additives on wear of 1045 and 304 steels in a dilute chloride solution

    International Nuclear Information System (INIS)

    The effect of rare earth salts, YCl3 and LaCl3, as corrosion inhibitors on corrosive wear of 1045 and 304 steels in a 0.1 mol l-1 NaCl solution was investigated. The objective of the research is to investigate the role of the corrosion inhibitors in resisting corrosive wear of the steels. Results of the study demonstrated that corrosion and corrosive wear of the steels were markedly decreased when 1000 ppm YCl3 and LaCl3 were added to the corrosive medium, respectively. In this work, polarization, nano-indentation, micro-scratch, and scanning Kelvin probing techniques were employed to investigate effects of YCl3 and LaCl3 additives on the corrosion behavior of the steels and on properties of surface films formed on the corroded steels. It was demonstrated that YCl3 and LaCl3 improved the protective role of oxide films formed on the steels. The modified films did not only suppress corrosion, but also improved surface mechanical properties of the steels. As a result, the corrosive wear of the steels in the dilute NaCl medium was effectively diminished

  14. Factors influencing chloride deposition in a coastal hilly area and application to chloride deposition mapping

    Directory of Open Access Journals (Sweden)

    H. Guan

    2009-09-01

    Full Text Available Chloride is commonly used as an environmental tracer for studying water flow and solute transport in the environment. It is especially useful for estimating groundwater recharge based on the commonly used chloride mass balance (CMB method. Strong spatial variability in chloride deposition in coastal areas is one difficulty encountered in appropriately applying the CMB approach. Furthermore, intensive vegetation clearance for agriculture, for example during the European settlement in many coastal areas of Australia, may have perturbed catchment chloride balance conditions for appropriate use in CMB applications. In order to deal with these issues, a high resolution chloride deposition map in the coastal region is needed. In this study, we examined geographic, orographic, and atmospheric factors influencing chloride deposition in the Mount Lofty Ranges (MLR, a coastal hilly area of approximately 9000 km2 spatial extent in South Australia, using partial correlation and regression analyses. The results indicate that coastal distance, and terrain aspect and slope are two most significant factors controlling chloride deposition. Coastal distance accounts for 65% spatial variability in chloride deposition, with terrain aspect and slope for 8%. The deposition gradient is about 0.08 gm-2 year-1 km-1 as one progresses inland. The results are incorporated into a published de-trended residual kriging approach (ASOADeK to produce a 1 km×1 km resolution annual chloride deposition map and a bulk precipitation chloride concentration map. The average uncertainty of the deposition map is about 30% in the western MLR, and over 50% in the eastern MLR. The maps will form a very useful basis for examining catchment chloride balances for use in the CMB application in the study area.

  15. Comportamiento ético gerencial : comportamientos gerenciales más valorados por empleados en Colombia, España e Inglaterra

    OpenAIRE

    Rodríguez Córdoba, María del Pilar

    2005-01-01

    El comportamiento ético está en el centro del comportamiento organizacional. La ética permea todos los aspectos de la vida humana porque está relacionada con las acciones que las personas prefieren de acuerdo con su juicio de lo que es correcto o incorrecto. Por lo tanto, los comportamientos de las personas involucran, consciente o inconscientemente, procesos éticos. Si el comportamiento organizacional es la disciplina que estudia el comportamiento de los seres humanos en los ambientes emp...

  16. Imagen publica del anallsis experimental del comportamiento: El papel de los profesores de anallsis conductual

    OpenAIRE

    JHON J. SANABRIA

    1999-01-01

    El presente artículo discute acerca de la situación actual del análisis del comportamiento en los medios masivos de comunicación y entre los estudiantes de psicología. Luego muestra dos formas en que los profesores de análisis del comportamiento pueden afectar la imagen pública de esta ciencia. Estas formas son: el profesor de análisis del comportamiento como modelo de comportamiento y el profesor de análisis del comportamiento como fuente de consecuencias para el comportamiento de ...

  17. Metal dissolution and maximum stress during SCC process of ferritic (type 430) and austenitic (type 304 and type 316) stainless steels in acidic chloride solutions under constant applied stress

    International Nuclear Information System (INIS)

    By using a constant load method and inductive coupled plasma (ICP) spectrometer, the metal dissolution and maximum stress (σmair) of type 430 ferritic stainless, and type 304 and type 316 austenitic stainless steels during stress corrosion cracking (SCC) process were investigated under a constant applied stress condition in 0.82 kmol/m3 hydrochloric acid (HCl) and 0.82 kmol/m3 acidic chloride (pH 1.0) solutions. The σmair of the specimens interrupted at various elongations up to failure under the same constant applied stress condition was measured at room temperature and air atmosphere by using an Instron type tensile machine. The metal dissolution behaviour of the stainless steels changed at the transition time (tss) in the corrosion elongation curve; that is, the dissolution rate before tss was larger than that after tss. The σmair decreased gradually with increasing elongation, but showed a rapid small reduction at tss and then decreased with elongation with a sudden reduction around fracture. The results obtained were discussed in terms of the amount of metal ions per the number of cracks, selective dissolution, reduction in cross sectional area and so on

  18. Chloride ingress prediction

    DEFF Research Database (Denmark)

    Frederiksen, Jens Mejer; Geiker, Mette Rica

    2008-01-01

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

  19. Qualidade fisiológica e armazenamento de sementes de algodão embebidas em solução de cloreto de mepiquat Physiological quality and storage of cotton seeds soaked in mepiquat chloride solution

    Directory of Open Access Journals (Sweden)

    Getúlio Takashi Nagashima

    2010-06-01

    Full Text Available Após tratamento de sementes, é comum a semeadura não ocorrer imediatamente. Eeste trabalho, objetivou-se determinar o efeito do armazenamento de sementes de algodão embebidas com regulador de crescimento Cloreto de Mepiquat (CM na qualidade fisiológica e manutenção do seu efeito como fitorregulador. Sementes da cultivar IPR 120 foram embebidas em soluções com CM nas doses de 2,5; 5,0 e 10,0 g i.a. kg-1 de sementes por 12 horas e secas a sombra em local ventilado, e testemunha sem tratamento. A avaliação foi feita por meio dos testes de germinação após armazenamento de 0, 30, 60, 90 e 180 dias após o tratamento (DAT. Aos 60 DAT foi avaliado o comprimento de plântulas, em rolo de papel, e a altura da planta, da inserção do nó cotiledonar, da área foliar e a massa da matéria seca de folhas e caule avaliada depois de um período de 24 dias após a emergência das plântulas cultivadas em vasos. O delineamento experimental foi o inteiramente casualizado com vinte tratamentos e quatro repetições, em esquema fatorial (4 doses e 5 tempos de armazenamento, para avaliar o teste de germinação. As sementes embebidas em cloreto de mepiquat podem ser armazenadas por pelo menos 60 dias, sem redução na sua qualidade fisiológica e mantendo o efeito redutor no crescimento das plantas, apresentando crescimento menor, antes mesmo da emergência e persiste por, pelo menos, 180 dias após o tratamento.Sowing is not usually possible immediately after seed treatment. This work was aimed at determining the effect of the storage of cotton seeds soaked with mepiquat chloride (growth regulator on physiological quality and maintenance of this effect as a plant regulator. Cotton seeds from cultivar IPR 120 were soaked in solutions with mepiquat chloride in doses of zero (control, 2,5: 5,0 and 10,0 g a.i.kg-1 of seeds for 12 hours and dried in the shade in an aerated place. The evaluation was done through germination at zero, 30, 60, 90 and 180

  20. Durability of cracked fibre reinforced concrete structures exposed to chlorides

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan De Place; Ekman, Tom; Hansen, Kurt Kielsgaard

    Durability studies are carried out by subjecting FRC-beams to combined mechanical and environmental load. Mechanical load is obtained by exposing beams to 4-point bending until a predefined crack width is reached, using a newly developed test setup. Exposure to a concentrated chloride solution is...... used as environmental load. The chloride penetration is characterized both qualitatively (UV-test) and quantitatively (chloride profile) and by microscopy. The test programme involves three different concrete qualities. Both steel fibres and polypropylene fibres are used in the concrete beams as well...... as main reinforcement. The effect of the cracks, the fibres and the concrete quality on the chloride penetration is studied....

  1. Validación del cuestionario de auto-reporte de comportamiento antisocial en adolescentes: CACSA

    OpenAIRE

    Paula Alarcón Bañares; Ricardo Pérez-Luco; Sonia Salvo; Gloria Roa; Katherine Jaramillo; Carla Sanhueza

    2010-01-01

    El estudio tiene por objetivo presentar la validación de un instrumento formulado racionalmente para evaluar, mediante auto-reporte, el comportamiento social en adolescentes chilenos (CACSA) y describir el comportamiento social de dos grupos: adolescentes escolarizados (N=1914) y adolescentes infractores de ley (N=264). El cuestionario posee 56 ítemes que exploran tres dimensiones generales, a) Comportamiento Prosocial (CPRO), b) Comportamiento Antisocial Total (CAT); y c) Víctima de Abuso de...

  2. Establecimiento de metas, comportamiento y desempeño

    OpenAIRE

    Henry Molina Mogollón

    2000-01-01

    Existen varios enfoques motivacionalesque se inclinan más hacia las causaspróximas del comportamiento que hacia las ecesidades y características (la suposición básica es que las personas se sienten más motivadas cuando sus valores, sus necesidadesy su carácter se ajustan al contexto laboral y organizacional que cuando no lo están). Los enfoques de causas próximas al comportamiento se centran principalmente en las creencias que la gente tiene acerca de su propio desempeño, como por ejemplo loq...

  3. Comportamiento de pacientes con lesión de menisco

    OpenAIRE

    Alejandro Álvarez López; Carlos Ortega González; Yenima García Lorenzo

    2013-01-01

    Fundamento: las lesiones de los meniscos de la rodilla constituyen una enfermedad muy frecuente en la actualidad, su comportamiento varía de acuerdo a la causa que la produce. Objetivo: mostrar el comportamiento de pacientes con lesiones de los meniscos de la rodilla. Método: se realizó un estudio observacional descriptivo en 42 pacientes con el diagnóstico clínico y artroscópico de lesión de menisco que fueron asistidos en el Hospital Universitario Manuel Ascunce Domenech de Camagüey entre e...

  4. Comportamiento elástico del concreto con agregado reciclado

    OpenAIRE

    Gámez García, Diana C.; Arredondo Rea, Susana Paola; Gómez Soberón, José Manuel Vicente; Almaral Sánchez, Jorge Luis; Castorena González, J.H.; Corral Higuera, Ramón

    2012-01-01

    Con el fin de participar activamente en la sustentabilidad de la industria de la construcción, se ha propuesto mejorar la durabilidad de las estructuras de concreto y el reemplazo parcial o total de sus componentes por materiales reciclados, de tal modo que sea factible reducir el insostenible impacto que ésta representa en la naturaleza. En el presente estudio se evaluó el comportamiento elástico del concreto fabricado con agregado reciclado. Se sabe que el comportamiento elástico del concre...

  5. Thermodynamics of sodium chloride solutions in steam

    Energy Technology Data Exchange (ETDEWEB)

    Pitzer, K.S.

    1983-03-31

    Gas-phase data from mass spectrometry are used to calculate the Gibbs energy of hydration of Na/sup +/ and Cl/sup -/ ions in steam. A similar hydration model for the ion pair NaCl is fitted to the experimental measurements of the solubility of NaCl in steam. The ionization constant calculated from these sources fits the directly measured values at 1073K and densities above 0.3g cm/sup -3/. At lower temperatures reasonable curves interpolate between the calculated values for low density and the direct measurements at higher density. Other thermodynamic properties are calculated for Na/sup +/, Cl/sup -/, and NaCl in steam. The partial molal heat capacity of the ions is very large in the range 700-1000K; this arises from the enthalpy of dissociation of water from the hydrated ions. The Born equation is compared with these results. A practical application to steam turbine technology is also considered.

  6. Chloride Ingress in Concrete Cracks under Cyclic Loading

    DEFF Research Database (Denmark)

    Küter, André; Geiker, Mette Rica; Olesen, John Forbes;

    2005-01-01

    increasing focus on the need for modeling the ingress of chloride into cracked concrete. Present models quantify chloride ingress in static cracks only, although several structural applications display dynamic loading conditions in an environment containing chlorides, e.g. marine structures and car parks....... Preliminary investigations have been undertaken to quantify the effect of dynamic load application on the chloride ingress into concrete cracks. Specimens were designed allowing ingress of a chloride solution into a single crack of a saturated unreinforced mortar beam. One set of specimens was subjected to a...... load frequency of ten applications per minute and a second set to one application per hour simulating static cracks, however limiting the ingress hampering effects of autogenous healing and a possible dense precipitation on the crack faces. The averaged chloride exposure interval of the crack faces was...

  7. COMPORTAMIENTO ORGANIZACIONAL VS. CUENTA DE RESULTADOS. ACERCAMIENTO DESDE UNA PERSPECTIVA SISTÉMICA

    OpenAIRE

    Rodeloy Castellanos Crúz

    2011-01-01

    Explorar la relación existente entre Comportamiento Organizacional y Cuenta de Resultados o eficiencia en general tiene sentido a partir de la propia definición del Comportamiento Organizacional (CO), un campo de estudio que se legitima dada su perspectiva pragmática: el Comportamiento Organizacional se traduce en Resultados.

  8. Comportamiento meiótico de diferentes especies de lulo, Solanum sp Meiotic behavior of lulo species, Solanum sp

    Directory of Open Access Journals (Sweden)

    Nancy Maricela Pareja Ordóñez

    2010-10-01

    Full Text Available Se realizó un análisis del comportamiento meiótico de las especies de lulo S. hirtum, S. quitoense y S. sessiliflorum, siguiendo la metodología convencional para los estudios de microsporogénesis. Se tomaron botones florales en diferentes estados de desarrollo, fijándolos por 24 horas en una solución de tres partes de etanol por una parte de ácido acético, saturada con trazas de cristales de cloruro férrico. Para la preparación de las placas se siguió la técnica de aplastamiento, se liberaron las células madres del grano de polen y finalmente se hicieron las observaciones bajo microscopía de luz. El análisis mostró que la meiosis se presenta en longitudes de antera que van desde los 2,79 mm hasta los 4,45 mm. La normalidad meiótica fue del 100%, tanto para meiosis I, como para la meiosis II. El índice meiótico en las tres especies fue del 99,98% lo cual indica que son buenos parentales y que pueden utilizarse en programas de cruzamiento. Las tres especies evaluadas tienen igual número de cromosomas (2n=2X=24. La frecuencia de anormalidades durante el proceso meiótico fue baja para S. hirtum, y alta para S. quitoense; sin embargo, la viabilidad polínica fue de gran magnitud (91,2-97,3%.An analysis of meiotic behavior of lulo species S. hirtum, S. quitoense and S. sessiliflorum, following the conventional methodology for studies of microsporogenesis was realized. Flower buds were taken at different stages of development, fixing them for 24 hours in a solution of three parts of ethanol per one part of acetic acid, saturated with traces of ferric chloride crystals. For the preparation of the slides following the technique of squash, releasing pollen mother cells and finally made the observations under light microscopy. The analysis showed that meiosis occurs in anther ranging from 2.79 to 4.45 mm. Meiotic normality was 100% for both meiosis I and II. The meiotic index in all three species was 99,98% indicating that they are

  9. 油田套管P110钢在含氯介质中的腐蚀行为研究%Corrosion Behavior of P110 Casing Steel in Chloride-Containing Solution

    Institute of Scientific and Technical Information of China (English)

    华万欣; 秦开明; 张再良; 王勇

    2012-01-01

    Corrosion behavior of P110 oil pipeline steel in NaCl, KC1 , CaCl2 solution was investigated in this paper. The effects of the temperature and the concentration on corrosion behavior were also analyzed. The results showed that the corrosion resistance of P110 steel increased with the temperature and the concentration of chloride ions. With the temperature increased, the corrosion potential increased and the corrosion current density decreased. The corrosion rate of P110 steel always abide by the order of NaCL>KCL>CaCl2%采用电化学方法测试了油田套管用P110钢在NaCl、KCl和CaCl2三种含氯溶液中的极化曲线,分析了温度和浓度对其腐蚀行为的影响规律.结果表明,在单一饱和氯化物溶液中,P110钢耐蚀性随着温度的升高而升高,溶液中的溶解氧含量降低,P110钢的腐蚀电位升高,腐蚀电流密度降低,在20、40、60℃时的饱和溶液中,P110钢耐蚀性随着浓度的增加而增加.P110钢在不同介质中的腐蚀速率均为:NaCl>KCl>CaCl2.

  10. Temas de Psicopatología del comportamiento delictivo

    OpenAIRE

    Herranz Bellido, Jesús; Díez Jorro, Miguel; Albaladejo Blázquez, Natalia; Cerezo Martínez, Ana María; Oltra Taverner, Dolores

    2006-01-01

    Relación entre diferentes dimensiones de personalidad y delito. Trastornos de personalidad y delito. Trastornos por uso de sustancias y delito. Enfermedad mental y delito. Evaluación del comportamiento criminal: Técnicas, procedimientos e instrumentos diagnósticos.

  11. An electrochemical method for accelerated testing of chloride diffusivity in concrete

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, T.; Gjoerv, O.E. (Norwegian Inst. of Tech., Trondheim (Norway). Div. of Building Materials)

    1994-01-01

    In the present paper an electrochemical method for accelerated testing of chloride diffusivity in concrete is presented. The method is based on a theoretical relationship between chloride diffusivity and observed steady-state rate of chloride migration through the concrete. The concentration of the chloride source solution has a significant influence on the rate of chloride migration and, therefore, a correction factor for ionic interaction in the relationship is introduced. It is shown that the relationship can be used for calculation of chloride diffusivity under various testing conditions. Some experimental results are also presented.

  12. Chloride isolation for accelerator mass spectrometry of 36Cl produced by atomic bomb neutrons

    International Nuclear Information System (INIS)

    Accelerator mass spectrometry was performed at the Munich tandem laboratory to determine the ratio of 36Cl/Cl in silicate rock samples exposed to neutrons of the Hiroshima atomic bomb. Chloride was chemically separated from silicate rock for this purpose. Five grams of silicate rock was fused with 30 g of sodium hydroxide and dissolved in 900 ml of water. The chloride in the resulting solution was spectrophotometrically determined. Chloride was precipitated as silver chloride by addition of appropriate amounts of silver nitrate, and silver chloride was then collected on a membrane filter. The chloride in the rock samples was thus isolated quantitatively. (author)

  13. Micellar solubilization in strongly interacting binary surfactant systems. [Binary surfactant systems of: dodecyltrimethylammonium chloride + sodium dodecyl sulfate; benzyldimethyltetradecylammonium chloride + tetradecyltrimethylammonium chloride

    Energy Technology Data Exchange (ETDEWEB)

    Treiner, C. (Universite Pierre et Marie Curie, Paris (France)); Nortz, M.; Vaution, C. (Faculte de Pharmacie de Paris-sud, Chatenay-Malabry (France))

    1990-07-01

    The apparent partition coefficient P of barbituric acids between micelles and water has been determined in mixed binary surfactant solutions from solubility measurements in the whole micellar composition range. The binary systems chosen ranged from the strongly interacting system dodecyltrimethylammonium chloride + sodium dodecyl sulfate to weakly interacting systems such as benzyldimethyltetradecylammonium chloride + tetradecyltrimethyammonium chloride. In all cases studied, mixed micelle formation is unfavorable to micellar solubilization. A correlation is found between the unlike surfactants interaction energy, as measured by the regular solution parameter {beta} and the solute partition coefficient change upon surfactant mixing. By use of literature data on micellar solubilization in binary surfactant solutions, it is shown that the change of P for solutes which are solubilized by surface adsorption is generally governed by the sign and amplitude of the interaction parameter {beta}.

  14. Combining sulfate electrowinning with chloride leaching

    Science.gov (United States)

    Fletcher, A. W.; Sudderth, R. B.; Olafson, S. M.

    1991-08-01

    Although the chloride leaching of copper sulfide concentrates has proved highly efficient, electrowinning from chloride solutions presents many difficulties, notably in cell design and the handling of the powder product. Sulfate electrowinning,on the other hand, continues to improve and has played a significant part in the widespread adoption of the solvent extraction-electrowinning process for copper recovery from low-grade ores. It has been found that the two steps can be combined by introducing a novel solvent extraction process after chloride leaching. This article presents the results of laboratory tests to prove the feasibility of this approach and discusses how it can be integrated into a commercially viable flow sheet.

  15. Evaluation of the susceptibility to pitting corrosion of steel api 5L x42 exposed to solutions containing chloride ions and CO{sub 2} by electrochemical noise measurements; Evaluacion de la susceptibilidad a la corrosion por picado del acero api 5l x42 expuesto a un ambiente con cloruros y CO{sub 2} mediante la tecnica de ruido electroquimico

    Energy Technology Data Exchange (ETDEWEB)

    Pena-Ballesteros, D.; Rodriguez-Vanegas, N.; Anteliz, C.; Sarmiento Klapper, H.

    2011-07-01

    The concentration of chloride ions and the partial pressure of CO{sub 2} play an important role in the degradation of low-carbon steels used for the construction of pipelines in oil and gas industry. In order to evaluate the susceptibility of carbon steel API 5L X42 to pitting corrosion electrochemical noise and linear polarization resistance measurements were carried out in aqueous solutions containing chloride ions and CO{sub 2}. The concentration of chloride ions was varied between, 10000 and 18000 ppm, and the CO{sub 2} partial pressure between 10 psi and 18 psi. Experimental results pointed out that the formation of protective layer, consisting mainly of FeCO{sub 3}, depends on the partial pressure of CO{sub 2} in the system. Nevertheless, the stability of this layer was considerably affected by increasing the concentration of chloride ions causing that localized corrosion has taken place in some areas of the surface of API 5L X42, which were detected by electrochemical noise technique. (Author) 10 refs.

  16. 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.

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

    Institute of Scientific and Technical Information of China (English)

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

    2004-01-01

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

  18. An insight into the passivation of cupronickel alloys in chloride environment

    Indian Academy of Sciences (India)

    J Mathiyarasu; N Palaniswamy; V S Muralidharan

    2001-02-01

    Cupronickels offer enhanced corrosion protection in marine environments by the formation of passive films on the surface. Cyclic voltammetric studies were carried on cupronickels in chloride solutions at H 6.3 to understand the role of chloride ions in passive film formation. Increase in nickel content of the alloy and of chloride ions in solution decreases film resistance. Chloride ions take part in reduction of the passive film to copper. A solid-state model for passive film formation involving chloride ions has been attempted.

  19. Estimation of trace chloride in nuclear grade sodium

    International Nuclear Information System (INIS)

    The author represents a method to determinate trace levels of chloride in sodium coolant in a fast neutron reactor. Vacuum distillation is used for separating chloride from sodium matrix. After separation, matrix interference from sodium salts is eliminated and a large sample amount can be taken for analysing chloride. In contrast with other similar mercuric thiocyanate colorimetric method in China, this method minimizes a glaring blank of colorimetric solution and determining influence of temperature. Therefore, it increases the precision in analysing chloride. The results of the research demonstrate that when a level of chloride in sodium is less than 1 μg/g, the precision is 37% (n = 10). The recoveries of chloride in high pure sodium demonstrate that when 15-30 μg/g of chloride is added in sodium, the recovery is 97.8%-98.6% and when 4μg/g of chloride is added, then the average recovery is 99.2%. And the relative standard deviation is 16.2% (n =7). It is demonstrated that a monitoring requirement of chloride can be satisfied with this method in coolant of sodium in a fast neutron reactor

  20. 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.

  1. Chloride supporting electrolytes for all-vanadium redox flow batteries.

    Science.gov (United States)

    Kim, Soowhan; Vijayakumar, M; Wang, Wei; Zhang, Jianlu; Chen, Baowei; Nie, Zimin; Chen, Feng; Hu, Jianzhi; Li, Liyu; Yang, Zhenguo

    2011-10-28

    This paper examines vanadium chloride solutions as electrolytes for an all-vanadium redox flow battery. The chloride solutions were capable of dissolving more than 2.3 M vanadium at varied valence states and remained stable at 0-50 °C. The improved stability appeared due to the formation of a vanadium dinuclear [V(2)O(3)·4H(2)O](4+) or a dinuclear-chloro complex [V(2)O(3)Cl·3H(2)O](3+) in the solutions over a wide temperature range. The all-vanadium redox flow batteries with the chloride electrolytes demonstrated excellent reversibility and fairly high efficiencies. Only negligible, if any, gas evolution was observed. The improved energy capacity and good performance, along with the ease in heat management, would lead to substantial reduction in capital cost and life-cycle cost, making the vanadium chloride redox flow battery a promising candidate for stationary applications. PMID:21922094

  2. Amperometric Sensor for Detection of Chloride Ions

    Directory of Open Access Journals (Sweden)

    Rene Kizek

    2008-09-01

    Full Text Available Chloride ion sensing is important in many fields such as clinical diagnosis, environmental monitoring and industrial applications. We have measured chloride ions at a carbon paste electrode (CPE and at a CPE modified with solid AgNO3, a solution of AgNO3 and/or solid silver particles. Detection limits (3 S/N for chloride ions were 100 μM, 100 μM and 10 μM for solid AgNO3, solution of AgNO3 and/or solid silver particles, respectively. The CPE modified with silver particles is the most sensitive to the presence chloride ions. After that we approached to the miniaturization of the whole electrochemical instrument. Measurements were carried out on miniaturized instrument consisting of a potentiostat with dimensions 35 × 166 × 125 mm, screen printed electrodes, a peristaltic pump and a PC with control software. Under the most suitable experimental conditions (Britton-Robinson buffer, pH 1.8 and working electrode potential 550 mV we estimated the limit of detection (3 S/N as 500 nM.

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

    International Nuclear Information System (INIS)

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

  4. Formation of an Ion-Pair Molecule with a Single NH+...Cl- Hydrogen Bond: Raman spectra of 1,1,3,3-Tetramethylguanidinium chloride in the solid state, in solution and in the vapor phase

    DEFF Research Database (Denmark)

    Berg, Rolf W.; Riisager, Anders; Fehrmann, Rasmus

    2008-01-01

    Some ionic compounds (salts) form liquids when heated to temperatures in the range of 200-300 °C. They may be referred to as moderate temperature ionic liquids. An example of such a compound is the 1,1,3,3- tetramethylguanidinium chloride, [TMGH]Cl, melting at ∼212 °C. The chemistry of this...... dimeric chloride ion-pair salt converged to give geometries near the established crystal structure of [TMGH]Cl. The structures and their binding energies are given as well as calculated vibrational harmonic normal modes (IR and Raman band wavenumbers and intensities). Experimentally obtained Raman...

  5. Bicarbonate secretion in vivo by rat distal tubules during alkalosis induced by dietary chloride restriction and alkali loading.

    OpenAIRE

    Levine, D Z; Iacovitti, M; Harrison, V

    1991-01-01

    To examine in vivo the separate effects on distal tubule JtCO2, of dietary chloride restriction, bicarbonate loading, and changes in luminal chloride concentration, we microperfused distal tubules at a physiologic flow rate (8 nl/min) with solutions containing either 45 or 0 mM chloride (after gluconate substitution). Rats were fed a diet containing zero, minimal, or normal amounts of chloride, while drinking either water or a solution of 0.15 M sodium bicarbonate. Neither extracellular fluid...

  6. Chloride substitution in sodium borohydride

    Science.gov (United States)

    Ravnsbæk, Dorthe B.; Rude, Line H.; Jensen, Torben R.

    2011-07-01

    The dissolution of sodium chloride and sodium borohydride into each other resulting in formation of solid solutions of composition Na(BH 4) 1- xCl x is studied. The dissolution reaction is facilitated by two methods: ball milling or combination of ball milling and annealing at 300 °C for three days of NaBH 4-NaCl samples in molar ratios of 0.5:0.5 and 0.75:0.25. The degree of dissolution is studied by Rietveld refinement of synchrotron radiation powder X-ray diffraction (SR-PXD) data. The results show that dissolution of 10 mol% NaCl into NaBH 4, forming Na(BH 4) 0.9Cl 0.1, takes place during ball milling. A higher degree of dissolution of NaCl in NaBH 4 is obtained by annealing resulting in solid solutions containing up to 57 mol% NaCl, i.e. Na(BH 4) 0.43Cl 0.57. In addition, annealing results in dissolution of 10-20 mol% NaBH 4 into NaCl. The mechanism of the dissolution during annealing and the decomposition pathway of the solid solutions are studied by in situ SR-PXD. Furthermore, the stability upon hydrogen release and uptake were studied by Sieverts measurements.

  7. comportamientos empoderados y participación de los empleados

    Directory of Open Access Journals (Sweden)

    Juan Pablo Román-Calderón

    2016-01-01

    Full Text Available El artículo presenta un estudio acerca de algunos antecedentes de los comportamientos empoderadosy la participación de los empleados en actividades de desarrollo de personal. El objetivo del estudio esanalizar la influencia que el apoyo organizacional y el empoderamiento psicológico ejercen sobre loscomportamientos empoderados. En el estudio participaron voluntariamente los empleados de 3 empre-sas maquiladoras del departamento de Antioquia (Colombia. Para el análisis de datos cuantitativos seutilizó la modelación por ecuaciones estructurales. Los resultados de los análisis se ̃nalan que el apoyoorganizacional ejerce una influencia indirecta positiva sobre la participación en actividades de desarrollode empleados y sobre los comportamientos proactivos. Adicionalmente, el empoderamiento actúa comomediador de dicha relación. En consecuencia, se recomienda la promoción de climas organizacionalescaracterizados por el apoyo organizacional y el empoderamiento.

  8. Comportamiento alimentario y obesidad infantil en Sonora, México

    Directory of Open Access Journals (Sweden)

    Juana María Hernández

    2010-10-01

    Full Text Available Este trabajo tiene como objetivo identificar los factores sociales asociados con la obesidad y con los comportamientos alimentarios de riesgo en un grupo de niños y niñas de 7 a 12 años de edad, en Hermosillo, Sonora, México. Los resultados muestran que el 40% de la población estudiada presentó sobrepeso y obesidad; el 39 % tuvo predisposición a prácticas alimentarias de riesgo y el 30% ya presentaba dichos rasgos. Se encontró que el miedo a la obesidad y la obsesión por la delgadez, la ansiedad por los alimentos consumidos, las prácticas alimentarias restrictivas, así como la presión social sobre la imagen corporal, fueron los principales factores asociados con los comportamientos alimentarios de riesgo en la niñez.

  9. Comportamiento frente a impacto de placas de vidrio/vinilester

    OpenAIRE

    García-Castillo, Shirley K.; Sánchez-Sáez, Sonia; Barbero, Enrique; Navarro, Carlos

    2005-01-01

    Los elementos estructurales de fibra de vidrio en matriz polimérica pueden verse expuestos durante su montaje, mantenimiento y vida en servicio a cargas impulsivas, lo que hace necesario estudiar su comportamiento frente a este tipo de cargas. En este trabajo realizaron ensayos de impacto sobre placas de un tejido equilibrado vidro/vinilester, utilizando los siguientes dispositivos experimentales: torre de caída, barra Hopkinson y cañón de gas, que permitieron trabajar en un ra...

  10. Gasometric titration for dimethylaluminum chloride analysis.

    Science.gov (United States)

    Wang, Lin; Maligres, Peter; Eckenroad, Kyle; Simmons, Bryon

    2016-06-01

    A gasometric titration method was developed to quantitate active alkylaluminum content in dimethylaluminum chloride solution to perform the stoichiometry calculation for the reaction charge. The procedure was reproducible with good precision, and the results showed good correlation with ICP-MS method. The gasometric titration is a simple, inexpensive alternative to analysis via ICP-MS which provides more selective analysis of methylaluminum species without the need for inertion. PMID:27017569

  11. Observaciones sobre el comportamiento de Dinomys branickii en cautiverio

    Directory of Open Access Journals (Sweden)

    López Liliana

    2000-12-01

    Full Text Available

    Esta investigación aporta nuevos conocimientos sobre el comportamiento de Dinomys branickii. Fue desarrollado en el marco de una investigación, cuya meta final es ayudar a su preservación mediante la liberación de animales incautados. Se trabajó con un grupo de 14 animales. Se logró obtener un catalogo y un etograma con las unidades comportamentales completando 50 horas de observación nocturno (6 p.m. a 6 a.m. Se definieron categorías comportamentales mas amplias para realizar un análisis de frecuencias y de duración de estas categorías. Se utilizo el método de Martin (1993 de muestreo continuo can animal focal. Se estableció que el horario de mayor actividad es de 11 p.m. a 1 a.m. Los resultados obtenidos muestran que el comportamiento más frecuente es el de mantenimiento y el de mayor duraci6n es el de descanso. Se establecieron diferencias entre el comportamiento de hembras y de machos.

  12. Comportamiento de pacientes con lesión de menisco

    Directory of Open Access Journals (Sweden)

    Alejandro Álvarez López

    2013-01-01

    Full Text Available Fundamento: las lesiones de los meniscos de la rodilla constituyen una enfermedad muy frecuente en la actualidad, su comportamiento varía de acuerdo a la causa que la produce. Objetivo: mostrar el comportamiento de pacientes con lesiones de los meniscos de la rodilla. Método: se realizó un estudio observacional descriptivo en 42 pacientes con el diagnóstico clínico y artroscópico de lesión de menisco que fueron asistidos en el Hospital Universitario Manuel Ascunce Domenech de Camagüey entre el 1ro de octubre de 2012 hasta el 31 de marzo de 2013. Resultados: predominaron las lesiones de tipo degenerativa de los meniscos. La edad promedio de las lesiones traumáticas fue de 32,6 años y la de los pacientes de causa degenerativa fue de 54,2 años. El tipo de desgarro más encontrado fue el degenerativo. La meniscectomía de tipo parcial fue la más realizada. Conclusiones: el comportamiento de pacientes con lesión de menisco es variable según la causa que lo provoca.

  13. [Degradation of succinylcholine chloride].

    Science.gov (United States)

    Németh, G; Török, I; Paál, T

    1993-05-01

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

  14. Laboratory stress corrosion cracking studies with sulfur acids and chlorides

    Energy Technology Data Exchange (ETDEWEB)

    Baylor, V.B.

    1985-10-01

    Stress corrosion cracking (SCC) caused by polythionic acid and/or chlorides has occurred in coal liquefaction pilot plants. This problem is also common in refineries and has been extensively researched. This study examines: (1) the relationship of the ASTM standard ferric sulfate-sulfuric acid test for determining sensitization to resistance to polythionic SCC; (2) the cracking resistance of higher-alloy. Fe-Ni-Cr materials and common austenitic stainless steels (SS); and (3) the effect of chloride concentrations up to 1% in polythionic acid solutions on cracking behavior. The ferric sulfatesulfuric acid test can be used as an acceptance test for materials resistant to polythionic acid SCC. More highly alloyed materials were more resistant to sensitization than most austenitic SS and were virtually unattacked in polythionic acid solutions containing up to 1% chloride. Chloride increased the corrosion rate and caused localized pitting but it did not significantly affect the number of failures or the failure mode.

  15. Reinforcement corrosion in alkaline chloride media with reduced oxygen concentrations

    International Nuclear Information System (INIS)

    It is commonly considered that the corrosion of steel in concrete is controlled by the oxygen content of the pore solution and there are service life models that relate the corrosion rate to the amount of oxygen. It is also commonly believed that in water saturated conditions the oxygen content in the pores is negligible and that underwater there is no risk of depassivation and the corrosion rate is very low. However, the available data on corrosion rates in immersed conditions do not indicate such performance; on the contrary corrosion develops when sufficient chloride reaches the reinforcement. In the present paper, results are presented for tests performed in alkaline chloride solutions that were purged with nitrogen to reduce the oxygen content. The results indicate that at very low oxygen concentrations, corrosion may develop in the presence of chlorides. The presence or absence of corrosion is influenced by the amount of chloride, the corrosion potential and the steel surface condition. (authors)

  16. MODALIDAD DE LA RETROALIMENTACIÓN Y COMPORTAMIENTO INTELIGENTE EN ESTUDIANTES UNIVERSITARIOS

    OpenAIRE

    Mauricio Ortega; Virginia Pacheco

    2014-01-01

    El comportamiento inteligente se caracteriza por ser una conducta efectiva que se ajusta a las situaciones novedosas. La retroalimentación, un factor de actualización del comportamiento inteligente, puede asumir diferentes modalidades sensoriales. El presente trabajo evaluó los efectos de proporcionar diferentes modalidades de retroalimentación en el desarrollo de comportamiento inteligente de universitarios en tareas de igualación de la muestra sobre el porcentaje de respuestas correctas. Pa...

  17. Optical Studies on Sol-Gel Derived Lead Chloride Crystals

    OpenAIRE

    Rejeena, I; Lillibai, B; Nithyaja, B; Nampoori, P.N V; P. Radhakrishnan

    2013-01-01

    Optical characterization of lead chloride crystals prepared by sol-gel method is reported. The relevant sol-gel technique is used for the preparation of PbCl2 samples with five different types. In this paper, we report the absorption and fluorescence behaviour of pure, UV& IR irradiated and electric & magnetic field applied lead chloride crystal samples in solution phase at two different concentrations. Optical bandgap and emission studies of these crystals are also done.

  18. Thermodynamic properties of ions in solutions of sodium and potassium chlorides in H2O-DMSO and D2O-DMSO mixtures of 278-323 K

    International Nuclear Information System (INIS)

    Thermodynamic characteristics of sodium and potassium chlorides ion solvation in mixtures of water and heavy water with dimethylsulfoxide have been obtained from data on temperature dependence of the standard e.m.f. of circuits without transfer. Regularities in their change depending on cation nature, temperature and composition of mixed solvent have been considered. Isotope effect in the Gibbs free energy of ΣNa+, Cl- and ΣK+, Cl- solvation has been calculated. 20 refs.; 3 figs.; 2 tabs

  19. A dose-finding, long-term study on the use of calcium chloride in saline solution as a method of nonsurgical sterilization in dogs: evaluation of the most effective concentration with the lowest risk

    OpenAIRE

    Leoci, Raffaella; Aiudi, Giulio; Silvestre, Fabio; Lissner, Elaine A; Marino, Fabio; Lacalandra, Giovanni M

    2014-01-01

    Background Canine overpopulation is a global issue with serious health and welfare implications. Nonsurgical methods of sterilization could yield positive impacts on this problem, but no long-term data on such methods are available. The objective of the current investigation was to determine the effects of intratesticular injections of calcium chloride dihydrate (CaCl2) in saline in dogs over a one year period. Five concentrations (0%, 10%, 20%, 30%, 60%) of CaCl2 in saline were administered ...

  20. Imagen publica del anallsis experimental del comportamiento: El papel de los profesores de anallsis conductual

    Directory of Open Access Journals (Sweden)

    Jhon J. Sanabria

    1999-01-01

    Full Text Available El presente artículo discute acerca de la situación actual del análisis del comportamiento en los medios masivos de comunicación y entre los estudiantes de psicología. Luego muestra dos formas en que los profesores de análisis del comportamiento pueden afectar la imagen pública de esta ciencia. Estas formas son: el profesor de análisis del comportamiento como modelo de comportamiento y el profesor de análisis del comportamiento como fuente de consecuencias para el comportamiento de los estudiantes. La descripción de estos casos se basa en los comportamientos adecuados. Finalmente, el artículo discute acerca de la importancia de estos asuntos en el futuro del análisis del comportamiento y cómo los profesores pueden mejorar la imagen pública del análisis del comportamiento haciéndolo agradable para más estudiantes.

  1. Pessimum effect of externally applied chlorides on expansion due to delayed ettringite formation: Proposed mechanism

    International Nuclear Information System (INIS)

    Mortars and concretes were subjected to a heat treatment cycle consisting of a pre-set period of 4 h at 23 deg. C followed by accelerated curing at 95 deg. C prior to storage at room temperature in water or limewater, 0.5 M, 2.8 M sodium chloride solutions. It was found that the specimens stored in 0.5 M sodium chloride solution gave a much greater expansion than those stored in limewater or 2.8 M sodium chloride solution. This pessimum influence of chlorides on expansion due to delayed ettringite formation deviates from the commonly held view that chlorides mitigate sulphate attack in concretes. The mechanism of the pessimum effect of chlorides on expansion due to delayed ettringite formation, and the final products of the associated phase transformations have been proposed. X-ray diffraction and differential thermal analysis techniques were used to follow phase transformations

  2. An autopsy case of zinc chloride poisoning.

    Science.gov (United States)

    Kondo, Takeshi; Takahashi, Motonori; Watanabe, Seiya; Ebina, Masatomo; Mizu, Daisuke; Ariyoshi, Koichi; Asano, Migiwa; Nagasaki, Yasushi; Ueno, Yasuhiro

    2016-07-01

    Ingestion of large amounts of zinc chloride causes corrosive gastroenteritis with vomiting, abdominal pain, and diarrhea. Some individuals experience shock after ingesting large amounts of zinc chloride, resulting in fatality. Here, we present the results of an administrative autopsy performed on a 70-year-old man who ingested zinc chloride solution and died. After drinking the solution, he developed vomiting, abdominal pain, and diarrhea, and called for an ambulance. Except for tachycardia, his vital signs were stable at presentation. However, he developed hypotension and severe metabolic acidosis and died. The patient's blood zinc concentration on arrival was high at 3030μg/dL. Liver cirrhosis with cloudy yellow ascites was observed, however, there were no clear findings of gastrointestinal perforation. The gastric mucosa was gray-brown, with sclerosis present in all gastric wall layers. Zinc staining was strongly positive in all layers. There was almost no postmortem degeneration of the gastric mucosal epithelium, and hypercontracture of the smooth muscle layer was observed. Measurement of the zinc concentration in the organs revealed the highest concentration in the gastric mucosa, followed by the pancreas and spleen. Clinically, corrosive gastroenteritis was the cause of death. However, although autopsy revealed solidification in the esophagus and gastric mucosa, there were no findings in the small or large intestine. Therefore, metabolic acidosis resulting from organ damage was the direct cause of death. PMID:27497327

  3. Estudio del comportamiento de los puentes tipo pony colgantes

    OpenAIRE

    Takeuchi Tam, Caori Patricia; León, Beatriz Elena; González, Mario Alberto

    2010-01-01

    En el país se encuentran numerosos puentes de paso a través intermedio colgantes. En este artículo se presentan la metodología y las conclusiones obtenidas en un estudio sobre el comportamiento de este tipo de puentes para las cargas existentes durante su proceso de construcción y puesta en servicio, mediante la constrastación entre modelos físicos y matemáticos. Igualmente, se estudió para estos modelos la estabilidad lateral.

  4. Comportamientos violentos entre pares: estrategias de prevención

    OpenAIRE

    Salas, Marta A.; Carreras, Julia A.; Casacci, María Elena; Garcia, Alicia; Hogas, Alejandro; Medina, Daniel

    2007-01-01

    En este trabajo se articulan dos proyectos de investigaciones llevados a cabo el primero investigó la incidencia en la subjetividad de la manera en que el adulto naturaliza las múltiples y variadas formas de castigo en la familia; el segundo y actual, investiga las manifestaciones de los comportamientos violentos en los niños, y las representaciones sociales de la violencia Objetivos: Identificar a los fines de su prevención las principales manifestaciones e interacciones violentas entre pare...

  5. Comportamiento mecánico del esmalte dental

    OpenAIRE

    Rivera Velásquez, Camilo Alberto

    2012-01-01

    Este trabajo presenta un análisis de las propiedades mecánicas del esmalte dental con el fin de caracterizar su comportamiento y comparar los resultados obtenidos con los reportados por estudios previos de investigaciones realizadas en los Estados Unidos. Se realizaron pruebas para pacientes Colombianos en busca de identificar las propiedades mecánicas del esmalte y su respuesta a diferentes estímulos mecánicos. Mediante ensayos estandarizados de microdureza se pudo establecer el comportamien...

  6. Comportamiento a alta temperatura de paneles de cemento de magnesio

    OpenAIRE

    Tapia García, Mario

    2015-01-01

    El objeto principal de este proyecto final de máster es analizar el comportamiento a altas temperaturas de paneles de cemento de magnesio. Para completar el estudio se realiza un comparativo con paneles de alma de yeso, utilizados habitualmente en construcción. Dado su alto contenido en Cloruro de Magnesio, se marca como objetivo paralelo determinar si la dosificación de los diferentes componentes condiciona la cantidad de HCl emitido. Por último, se investiga la existencia de normas de refer...

  7. Comportamiento alimentario y obesidad infantil en Sonora, México

    OpenAIRE

    Juana María Hernández; Gloria María Cañez; Hevilat Frías

    2010-01-01

    Este trabajo tiene como objetivo identificar los factores sociales asociados con la obesidad y con los comportamientos alimentarios de riesgo en un grupo de niños y niñas de 7 a 12 años de edad, en Hermosillo, Sonora, México. Los resultados muestran que el 40% de la población estudiada presentó sobrepeso y obesidad; el 39 % tuvo predisposición a prácticas alimentarias de riesgo y el 30% ya presentaba dichos rasgos. Se encontró que el miedo a la obesidad y la obsesión por la delgadez, la ansie...

  8. Un enfoque declarativo para modelar el comportamiento en sistemas reactivos

    OpenAIRE

    Asteasuain, Fernando

    2010-01-01

    Existe consenso en la comunidad académica y de ingenieros de software que es fundamental entender, modelar y describir el comportamiento del software complejo desde etapas tempranas del desarrollo. El paradigma de descripción declarativa, basado en el modelado de las propiedades y objetivos esenciales de los objetos y agentes, posee características especialmente prometedoras para este tipo de desafíos. Sin embargo, las alternativas existentes en este paradigma son lógicas temporales que posee...

  9. Comportamiento acústico de espacios cubiertos con estructuras textiles

    OpenAIRE

    Maya Simoes, Flavio

    2000-01-01

    En el presente trabajo estudiamos el comportamiento acústico de espacios cubiertos con textiles. Presentamos una reseña histórica de usos de textiles en la arquitectura, de la prehistoria hasta hoy. Realizamos una búsqueda bibliográfica y presentamos los resultados encontrados. Presentamos la metodología actual de análisis acústico que se utiliza en ensayos de laboratorio, simulaciones y mediciones. Estudiamos la absorción sonora de los materiales de las cubiertas textiles, en ensayos de labo...

  10. Estudio del comportamiento poscosecha de la ciruela 'Reina Claudia verde'

    OpenAIRE

    Ribeiro, Maria da Graça Teles de Sousa Pacheco de Carvalho

    2006-01-01

    En este trabajo se ha realizado una caracterización de ciruelas ‘Reina Claudia verde’ y se ha estudiado el comportamiento de las mismas durante la poscosecha. La ciruela ‘Reina Claudia verde’ es autóctona de la región de Estremoz/Borba en el Alentejo, Portugal, con Denominación de Origen Protegida, posee características organolépticas excepcionales, y es una fruta muy apreciada por los consumidores. Durante la campaña de ciruela tienen lugar picos en la producción y se acumula en la Cooperati...

  11. Comportamiento en cautiverio de un individuo joven de Tremarctos ornatus

    OpenAIRE

    Viviana Gómez

    2009-01-01

    El Oso Andino es el único úrsido existente en Sur América y los estudios realizados sobre esta especie son recientes e insuficientes. Por esta razón, se realizaron muestreos de los comportamientos de un Oso Andino Tremarctos ornatus, juvenil (4 meses de edad apróx.) procedente de una entrega voluntaria del Ejército Nacional de Colombia. Durante los meses de febrero y marzo de 2009 en elCentro de Paso para Fauna Silvestre, en el marco del convenio de la Fundación Universitaria Juan de Castella...

  12. Comportamiento de estructuras de material compuestos sometidas a cargas impulsivas

    OpenAIRE

    Buitrago Pérez, Brenda Lisbeth

    2012-01-01

    En esta tesis se ha estudiado el comportamiento frente a impacto, tanto de alta velocidad como de baja velocidad, de diversas estructuras fabricadas con distintos materiales compuestos. Se han analizado estructuras sándwich de fibra de vidrio con núcleo de espuma de polivinilo y de pieles de fibra de carbono con núcleo de panal de abeja de aluminio, así como laminados monolíticos de fibra de vidrio/poliéster y carbono/epoxi. Se evalúo la respuesta frente a impacto de baja velocidad de estruct...

  13. EL COMPORTAMIENTO FINANCIERO DE LAS EMPRESAS SOCIALMENTE RESPONSABLES

    Directory of Open Access Journals (Sweden)

    Charlo Molina, M.J

    2010-01-01

    Full Text Available El objeto del presente trabajo es analizar determinadas variables de naturaleza financiera en las empresas consideradas socialmente responsables, las que forman parte del índice de sostenibilidad español FTSE4Good IBEX, y determinar si existen diferencias significativas en su comportamiento respecto a las del resto de índices de la familia IBEX. Los resultados muestran que las acciones de las empresas socialmente responsables obtienen una rentabilidad superior para el mismo nivel de riesgo sistemático y que su sensibilidad ante los cambios en el mercado es mayor.

  14. Modelos de comportamiento y novela femenina: Jane Austen

    OpenAIRE

    Mandingorra LLavata, María Luz

    1996-01-01

    El objetivo del artículo es descubrir la forma en que la clase media inglesa de finales del siglo XVIII se servía de la escritura para la afirmación de un modelo de comportamiento propio frente al aristocrático, a través de las obras de Jane Austen. Si la ficción literaria en general, en la medida en que es representación, nos ilustra acerca de la imagen que una sociedad pretende dar de sí misma, la novela femenina inglesa de finales del siglo XVIII y comienzos del XIX constituye, además, un ...

  15. MEDIOS ELECTRÓNICOS Y COMPORTAMIENTO ANTISOCIAL EN ADOLESCENTES

    OpenAIRE

    Francisco Javier Rodríguez; Francisco Javier Herrero; Anastasio Ovejero; Carolina Bringas

    2008-01-01

    El comportamiento antisocial o inadaptado viene determinado por diversas variables, tanto individuales como contextuales, que pueden actuar como factores de riesgo. Uno de estos factores es el uso de los medios de comunicación electrónicos, especialmente de las más nuevas tecnologías, aunque diversos estudios aseveran que este consumono ejerce una responsabilidad exclusiva en la adquisición de conductas antisociales por parte de los adolescentes. Utilizando una muestra de 331 jóvenes de ambos...

  16. Comportamiento de la trichomonosis vaginal en un grupo de adolescente

    OpenAIRE

    Lázara Rojas Rivero; Alina Izquierdo Cirer; Carlos Sarría Pérez; Idalia Sariego Ramos; Jorge FragaNodarse

    2003-01-01

    Se estudió un total de 275 adolescentes en las edades comprendidas entre 10 y 19 años procedentes de la consulta infanto-juvenil, de interrupción de embarazos y de infecciones de transmisión sexual del Hospital Docente Ginecoobstérico "Ramón González Coro" y el Hospital "Eusebio Hernández", ambos de Ciudad de La Habana, en el período comprendido de agosto de 1999 a septiembre de 2000, para conocer el comportamiento de la infección por Trichomonas vaginalis en este grupo poblacional. Se report...

  17. Ictus hemorrágico: Comportamiento epidemiológico

    OpenAIRE

    Lubín Acosta Rodríguez; César Mustelier Fernández; Mailén Molero Segrera; Mireille Molero Segrera

    2002-01-01

    Se hizo un estudio descriptivo-retrospectivo y se abordó el comportamiento epidemiológico de las formas de presentación intraparenquimatosa y subaracnoidea en el Hospital "Celia Sánchez Manduley" de Manzanillo, durante el año 1998, para establecer los indicadores de morbilidad, mortalidad, letalidad, variables biológicas y distributivas del ictus hemorrágico. Se halló que la morbilidad por hemorragia intraparenquimatosa triplicó las formas de hemorragia subaracnoidea, dentro de una tasa de 4,...

  18. Corrosion of reinforcement induced by environment containing chloride and carbon dioxide

    Indian Academy of Sciences (India)

    Vladimír Živica

    2003-10-01

    Reinforced concrete structures during their exploitation may be exposed to the common action of carbonation and chlorides causing corrosion of steel reinforcement. Therefore, the related data seem to be interesting and important when the evaluation of the service life of the structures is the object of interest. This fact was a motivation for the present experimental study on the sequence of action of chloride solutions and carbonation of the embedding concrete. The results obtained show that carbonation of concrete foregoing the action of chloride solutions may intensify the process of corrosion of steel reinforcement in comparison to the converse sequence of the action of mentioned media. At the same time the natrium chloride solution has been shown as a more aggressive medium opposite to the calcium and magnesium chloride solutions.

  19. Grado de competencia social y comportamientos antisociales, delictivos y no delictivos en adolescentes

    Directory of Open Access Journals (Sweden)

    Ramón Arce

    2011-01-01

    normativa y evidenciaron una relación entre incompetencia social y comportamientos antisociales y delictivos, así como un efecto de escalada, es decir, el grado de conducta desviada (delictiva, antisocial no delictiva y normal va ligado al grado de (incompetencia social. Se discuten las implicaciones de estos hallazgos para el tratamiento de los menores con comportamientos antisociales, delictivos y no delictivos.

  20. Valyl benzyl ester chloride

    Directory of Open Access Journals (Sweden)

    Grzegorz Dutkiewicz

    2010-02-01

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

  1. Production and mitigation of acid chlorides in geothermal steam

    Energy Technology Data Exchange (ETDEWEB)

    Simonson, J.M.; Palmer, D.A.

    1995-06-01

    Measurements of the equilibrium distribution of relatively nonvolatile solutes between aqueous liquid and vapor phases have been made at temperatures to 350{degrees}C for HCl(aq) and chloride salts. These data are directly applicable to problems of corrosive-steam production in geothermal steam systems. Compositions of high-temperature brines which could produce steam having given concentrations of chlorides may be estimated at various boiling temperatures. Effects of mitigation methods (e.g., desuperheating) can be calculated based on liquid-vapor equilibrium constants and solute mass balances under vapor-saturation conditions.

  2. Diferencias entre homosexuales y heterosexuales en comportamiento y personalidad

    Directory of Open Access Journals (Sweden)

    Mirta Granero

    1984-01-01

    Full Text Available La autora informa de los resultados de 120 sujetos (30 varones heterosexuales, 30 varones homosexuales, 30 mujeres heterosexuales y 30 mujeres homosexuales, a los que se aplicaron cuestionarios y tests para averiguar comportamientos y rasgos de personalidad. Para el análisis de cada rasgo o comportamiento, los datos fueron clasificados por dos variables: Orientación sexual y Sexo. Se encontraron algunas diferencias significativas entre homosexuales y heterosexuales, como así también entre varones y mujeres, independientes de su orientación sexual. Se cuestiona si algunos tests tienen validez para algunos de estos grupos. Se piensa que puede haber respuestas determinadas por la presión social en la que vive el homosexual, en vez de por la variable que se supone que mide en él. Este primer informe, es parte de un trabajo más ambicioso, que la autora está realizando en la ciudad de Rosario (Argentina

  3. Gradualismo y equilibrio puntuado en el origen del comportamiento humano

    Directory of Open Access Journals (Sweden)

    Ignacio de la TORRE SÁINZ

    2009-12-01

    Full Text Available RESUMEN: La visión tradicional de la evolución del comportamiento ha sobrevalorado algunos de los aspectos materiales de la cultura concebidos como propiamente humanos. Sin embargo, en los últimos años una serie de estudios han revelado la existencia de estos rasgos adaptativos en otros primates. Esto ha cuestionado seriamente la validez de muchos de las aproximaciones materialistas que parten de la premisa de que sólo lo que aparece en el registro arqueológico es factible de ser interpretado. En este artículo se pasa revista a las explicaciones gradualistas y puntuadas de la aparición del comportamiento humano, y se subraya la necesidad de enfocar el problema desde una consideración socioecológica.ABSTRACT: The traditional views on the evolution of human behavior have overemphasized some of the material aspects of culture, conceived as properly human. However, during the last years, the studies of apes have revealed the existence of these adaptive traits in other primates. This fact has seriously damaged the validity of such a materialist - biased approach (only what is left in the archaeological record is liable to be interpreted as a clear-cut human diagnosis. Gradualist and punctuated explanations of the emergence of human behavior are mentioned as theoretical frameworks and the need of focusing such an issue from a socio-ecological consideration is proposed.

  4. Comportamiento predestete de cabritos cruzados en Guanajuato, México

    Directory of Open Access Journals (Sweden)

    Sonia Castillo-Rodríguez

    2013-10-01

    Full Text Available Objetivo. Los pesos al nacimiento y al destete fueron registrados para evaluar el comportamiento pre-destete de cabritos cruzado en ocho pequeñas fincas de producción de leche de cabra en Guanajuato, México. Materiales y métodos. Se usaron 234 registros de cabritos, las cabras fueron mantenidas en condiciones de pastoreo con suplementación de un concentrado comercial. Los cabritos eran cruzados, de las razas Sannen, Alpina y Toggenburg, los datos fueron analizados con un modelo estadístico que considero los efectos de rebaño (RE, grupo contemporáneo (GC, número de parto (NP, tipo parto (TP y sexo del cabrito (SC. Resultados. Las medias de peso al nacer, peso a los 60 días de edad y la ganancia diaria de peso fueron 3.4±0.5 (rango 2.0 a 5.5, 13.7±1.8 (rango 8.0 a 17.5 y 0.17±0.02 (0.08 a 0.23 kg. El peso al nacimiento fue afectado (p<0.01 por RE, GC, NP, TP y SC. Sin embargo, el peso a 60 días y ganancia diaria de peso fueron afectadas (p<0.05 por RE y SC. Conclusiones. El rebaño afectó el comportamiento de los cabritos.

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

    Institute of Scientific and Technical Information of China (English)

    周宁波; 陈白珍; 何新快; 李义兵

    2005-01-01

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

  6. Pitting Corrosion of Ni3(Si,Ti) Intermetallic Compound at Various Chloride Concentrations

    OpenAIRE

    Gadang Priyotomo

    2013-01-01

    The pitting corrosion of Ni3(Si,Ti) intermetallic compound was investigated as function of chloride concentration by using electrochemical method and scanning electron microscope in sodium chloride solutions at 293 K.  In addition, the pitting corrosion of type C276 alloy was also studied under the same experimental condition for comparison.  The pitting potential obtained for the intermetallic compound decreased with increasing chloride concentration.  The specific pitting potential and pitt...

  7. Anodic Behavior of Alloy 22 in Calcium Chloride and in Calcium Chloride Plus Calcium Nitrate Brines

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-05-13

    Alloy 22 (UNS N60622) is a nickel-based alloy, which 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 concentrated calcium chloride (CaCl{sub 2}) brines and to evaluate the inhibitive effect of nitrate, especially to localized corrosion. Standard electrochemical tests such as polarization resistance and cyclic polarization were used. Results show that the corrosion potential of Alloy 22 was approximately -360 mV in the silver-silver chloride (SSC) scale and independent of the tested temperature. Cyclic polarization tests showed that Alloy 22 was mainly susceptible to localized attack in 5 M CaCl{sub 2} at 75 C and higher temperatures. The addition of nitrate in a molar ratio of chloride to nitrate equal to 10 increased the onset of localized corrosion to approximately 105 C. The addition of nitrate to the solution also decreased the uniform corrosion rate and the passive current of the alloy.

  8. Open cycle lithium chloride cooling system

    Science.gov (United States)

    Lenz, T. G.; Loef, G. O. G.; Iyer, R.; Wenger, J.

    1983-05-01

    A lithium chloride open cycle absorption chiller has been designed, built and tested. Solution reconcentration takes place in a small counter current packed column supplied with solar heated air. Removal of noncondensable gases that enter the chiller dissolved in the strong solution and the make-up refrigerant streams is accomplished by a liquid-jet ejector and a small vacuum pump. Cooling capacities approaching 1.4 tons and COP levels of 0.58 have been achieved at non-optimum operating conditions. Test results from preliminary system operation suggest that mass transfer processes in both the packed column reconcentrator and the absorber are controlled by concentration gradients in the lithium chloride solution. Liquid phase controlled mass transfer dictates an operating strategy different from the previously assumed gas phase controlled process to obtain maximum rates of evaporation in the packed column. Determination of optimal operating conditions leading to decreased electrical power consumption and improved cooling capacity and coefficient of performance will require further analysis and testing.

  9. Benzalkonium Chloride Intoxication Mimicking Herpes Zoster Encephalitis

    Directory of Open Access Journals (Sweden)

    Ekrem Güler

    2011-06-01

    Full Text Available Benzalkonium chloride (BAC is a frequently used disinfectant and its most well-known side effect is contact dermatitis. In this report, two children who had vesicular dermatitis, headache, lethargy, fever and encephalopathy mimicking Herpes zoster encephalitis were presented. Their consciousness level improved on the second day. From the medical history it was understood that the mother had applied 20% BAC solution to the scalps of two children. The aim of the presentation of this report is to draw attention to the fact that BAC application to the scalp for treating pediculosis capitis may resemble the herpes encephalitis clinical picture.

  10. Comportamientos relacionados con la salud en estudiantes de secundaria

    Directory of Open Access Journals (Sweden)

    Seil Lamadrid Núñez

    2014-06-01

    Full Text Available ResumenLos perfiles de morbimortalidad de un país se encuentran ligados a patrones de comportamientos que pueden ser modificados, y que cualquier persona puede adoptar conductas saludables para contribuir a su bienestar. Aunque sea difícil encontrar cualquier cosa que no tendría ningún impacto en salud, en el repertorio de la conducta humana hay algunos hábitos considerados como factores de riesgo. En esta revisión se han considerado el consumo legal e ilegal de sustancias, las relaciones sexuales y la orientación sexual debido al impacto de estos patrones en salud en los adolescentes. Es bien sabido que los grupos sociales, las presiones académicas, la falta de educacion, entre otros aspectos, han determinado en gran medida la adopción de conductas o estilos de vida que no son saludables. Para todos los comportamientos de riesgo las estrategias de promoción y prevención son necesarias y por ello debe vincularse además de la escuela, la familia, los compañeros de los adolescentes, y el entorno socio cultural en el que estos se desenvuelven, el papel de los medios masivos de comunicación por la trascendental influencia que ejercen sobre la comunidad deben ser tenidos muy en cuenta a la hora de promover comportamientos saludables. (Duazary 2009-II 165-169AbstractThe profiles of morbidity and mortality in a country are linked to patterns of behavior that can be modified, and that anyone can adopt healthy behaviors to contribute to their welfare. Although it is hard to find anything that would have no impact on health, into the repertoire of human behavior there are some habits considered as risk factors. in this review have been taken into account the consumption of legal and illegal substances, sexual and sexuality orientation due to the impact of these patterns in adolescent health. It is well known that social groups, academic pressures, lack of education, among others, have largely determined the adoption of behaviors or

  11. Sodium chloride, potassium chloride, and virulence in Listeria monocytogenes.

    OpenAIRE

    MYERS, E. R.; Dallmier, A W; Martin, S E

    1993-01-01

    Virulence, as determined in a mouse model, and the virulence factor activities of catalase, superoxide dismutase, and listeriolysin O were examined in a parental strain (10403S) and in a nonhemolytic mutant strain (DP-L224) of Listeria monocytogenes. The cells were propagated in media containing various concentrations of sodium chloride or potassium chloride. Strains 10403S and DP-L224 exhibited significant increases in catalase activity and listeriolysin O activity when grown in medium conta...

  12. Stabilizing Plutonium oxide material containing Chloride salts at PFP

    International Nuclear Information System (INIS)

    PFP had over 900 items, weighing more than 1100 kg consisting of impure plutonium oxides referred to as high chloride content plutonium oxides. Tests were conducted to examine items for physical characteristics. After 17 years of storage, the inner food-pack cans maintained integrity with very little evidence of corrosion. Items were washed with water to remove chloride salts. Chloride was readily soluble with plutonium concentrations less than 0.05 g/L in wash solution from all but one of seven items. Washed material was calcined at 1000 C. The calcined material passed the storage test for less than 0.5% water. Unopened items were examined using gamma energy analysis to determine if a prompt gamma (n, x) interaction could be used to screen out items with low chloride concentrations. The prompt gamma was not measurable. A 2168 keV gamma from the (α, x) interaction with chloride correlated within 10% of the chloride concentration measured from washing the item with water

  13. Comportamiento a fractura de polímeros envejecidos

    Directory of Open Access Journals (Sweden)

    Argüelles, A.

    2001-04-01

    Full Text Available The dynamic fracture behaviour of three types of composite materials was studied. Two of the composites were manufactured from the same thermoplastic resin, reinforced with glass or carbon fibre fabric, respectively; the other one, was manufactured with an epoxy resin, reinforced with carbon fibre fabric. The composites were subjected to accelerated ageing effect on a climatic test chamber, under humidity and temperature control, for different notch-Width ratios. The dynamic fracture behaviour was analysed by applying the ASTM E 24.03.03 Standard proposal to Charpy instrumented test results with the goal of validating this testing procedure for composite materials.

    Se estudia aquí el comportamiento a fractura en régimen dinámico de tres tipos de materiales compuestos: dos de ellos fabricados a partir de una misma resina termoplástica reforzada con tejido de fibra de vidrio o de carbono y el otro a partir de una resina de tipo epoxi reforzada con tejido de fibra de carbono. Todos ellos fueron sometidos a envejecimiento acelerado en cámara climática con control de humedad y de temperatura, para diferentes relaciones entre longitud de fisura y ancho de la probeta. El comportamiento a fractura se analizó en régimen dinámico a partir de los datos obtenidos de ensayos Charpy instrumentados, aplicando la propuesta de norma ASTM E 24.03.03, con el objetivo último de validar esta metodología de ensayo sobre materiales compuestos.

  14. Traceable mean activity coefficients and osmotic coefficients in aqueous magnesium chloride solutions at T = 298.15 K up to a molality of 3.0 mol · kg−1

    International Nuclear Information System (INIS)

    Highlights: • This work reports new equations for thermodynamic activity quantities in aqueous MgCl2 solutions. • The new equations are functionally the same as those obtained previously solutions of CaCl2 and uni-univalent electrolytes. • The new activity and osmotic coefficients are fully traceable and transparent. • These new values were tested thoroughly with existing literature data. -- Abstract: The Hückel equation used in this study for the thermodynamic activity quantities in dilute MgCl2 solutions up to an ionic strength (=Im) of 1.5 mol · kg−1 contains two parameters being dependent on the electrolyte, i.e., those of B and b1. The former is linearly related to the ion-size parameter in the Debye–Hückel equation and the latter is the coefficient of the linear correction term with respect to the molality. For more concentrated solutions up to Im of 9.0 mol · kg−1, an extended Hückel equation was used. For it, the Hückel equation was extended with a quadratic term in molality, and the coefficient of this term is the third parameter b2. Parameters B and b1 for dilute MgCl2 solutions were obtained from the isopiestic data of Robinson and Stokes for solutions of this salt and KCl [Trans. Faraday Soc. 36 (1940) 733] by using the previous Hückel parameters for dilute KCl solutions [J. Chem. Eng. Data 54 (2009) 208]. The resulting parameters for MgCl2 solutions were successfully tested with all isopiestic data available in the literature for dilute solutions of this salt. For less dilute solutions, new values for parameters b1 and b2 were determined for the extended version of the Hückel equation of MgCl2 solutions from the isopiestic data of Rard and Miller [J. Chem. Eng. Data 26 (1981) 38] for NaCl and MgCl2 solutions but the dilute-solution value for parameter B was used. The previous extended Hückel equation for concentrated NaCl solutions was used in this estimation (see the KCl citation above). In the tests of the new parameter values

  15. Involvement of chloride in renin secretion from isolated rat glomeruli

    DEFF Research Database (Denmark)

    Skøtt, O; Jensen, B L

    M) inhibited renin release reversibly. Substitution of Cl- with nitrate (101 mM) stimulated renin secretion. Substitution with iodide (15 or 101 mM) had no consistent effect. The stimulation induced by calcium-free solutions was high in May and low in September. In the absence of chloride, the response to...

  16. A chronopotentiometric approach for measuring chloride ion concentration

    NARCIS (Netherlands)

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

    2013-01-01

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

  17. 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

  18. Chloride channels in stroke

    Institute of Scientific and Technical Information of China (English)

    Ya-ping ZHANG; Hao ZHANG; Dayue Darrel DUAN

    2013-01-01

    Vascular remodeling of cerebral arterioles,including proliferation,migration,and apoptosis of vascular smooth muscle cells (VSMCs),is the major cause of changes in the cross-sectional area and diameter of the arteries and sudden interruption of blood flow or hemorrhage in the brain,ie,stroke.Accumulating evidence strongly supports an important role for chloride (Clˉ) channels in vascular remodeling and stroke.At least three Clˉ channel genes are expressed in VSMCs:1) the TMEM16A (or Ano1),which may encode the calcium-activated Clˉ channels (CACCs); 2) the CLC-3 Clˉ channel and Clˉ/H+ antiporter,which is closely related to the volume-regulated Clˉ channels (VRCCs); and 3) the cystic fibrosis transmembrane conductance regulator (CFTR),which encodes the PKA-and PKC-activated Clˉ channels.Activation of the CACCs by agonist-induced increase in intracellular Ca2+ causes membrane depolarization,vasoconstriction,and inhibition of VSMC proliferation.Activation of VRCCs by cell volume increase or membrane stretch promotes the production of reactive oxygen species,induces proliferation and inhibits apoptosis of VSMCs.Activation of CFTR inhibits oxidative stress and may prevent the development of hypertension.In addition,Clˉ current mediated by gammaaminobutyric acid (GABA) receptor has also been implicated a role in ischemic neuron death.This review focuses on the functional roles of Clˉ channels in the development of stroke and provides a perspective on the future directions for research and the potential to develop Clˉ channels as new targets for the prevention and treatment of stroke.

  19. Influence of Fly Ash on Surface Chloride Concentration Under Shallow Immersion Condition

    OpenAIRE

    Liu, Jun; Wang, Xiaodong; Xing, Feng; Han, Ningxu

    2014-01-01

    In this paper, the influence of fly ash content on concrete surface chloride concentration was investigated through periodical tests of surface chloride concentration of concrete by immersing three kinds of concrete specimens in 5.0 wt.% sodium chloride solution. One kind of specimen is common concrete without fly ash, whereas the other two kinds of specimens are mixed with fly ash. The results show that the surface chloride ion concentration ranges from 0.295 to 0.777 wt.% for the immersed c...

  20. The effect of pH on the corrosion behavior of intermetallic compounds Ni3(Si,Ti) and Ni3(Si,Ti) + 2Mo in sodium chloride solutions

    Science.gov (United States)

    Priyotomo, Gadang; Nuraini, Lutviasari; Kaneno, Yasuyuki

    2015-12-01

    The corrosion behavior of the intermetallic compounds, Ni3(Si,Ti) (L12: single phase) and Ni3(Si,Ti) + 2Mo (L12 and (L12 + Niss) mixture region), has been investigated using an immersion test, electrochemical method and surface analytical method (SEM; scanning electron microscope and EDAX: Energy Dispersive X-ray) in 0.5 kmol/m3 NaCl solutions at various pH. The corrosion behavior of nickel alloy C-276 was studied under the same experimental conditions as a reference. It was found that the uniform attack was observed on Ni3(Si,Ti) for the immersion test at lower pH, while the pitting attack was observed on this compound for this test at neutral solution. Furthermore, Ni3(Si,Ti)+2Mo had the preferential dissolution of L12 compared to (L12 + Niss) mixture region at lower pH, while pitting attack occurred in (L12 + Niss) mixture region at neutral solution. For both intermetallic compounds, the magnitude of pitting and uniform attack decrease with increasing pH of solutions. From the immersion test and polarization curves, the corrosion resistance of Ni3(Si,Ti)+2Mo is lower than that of Ni3(Si,Ti), while the nickel alloy C-276 is the highest one at various pH of solutions. On the other hand, in the lower pH of solutions, the corrosion resistance of tested materials decreased significantly compared to those in neutral and higher pH of solutions.

  1. The effect of pH on the corrosion behavior of intermetallic compounds Ni3(Si,Ti) and Ni3(Si,Ti) + 2Mo in sodium chloride solutions

    International Nuclear Information System (INIS)

    The corrosion behavior of the intermetallic compounds, Ni3(Si,Ti) (L12: single phase) and Ni3(Si,Ti) + 2Mo (L12 and (L12 + Niss) mixture region), has been investigated using an immersion test, electrochemical method and surface analytical method (SEM; scanning electron microscope and EDAX: Energy Dispersive X-ray) in 0.5 kmol/m3 NaCl solutions at various pH. The corrosion behavior of nickel alloy C-276 was studied under the same experimental conditions as a reference. It was found that the uniform attack was observed on Ni3(Si,Ti) for the immersion test at lower pH, while the pitting attack was observed on this compound for this test at neutral solution. Furthermore, Ni3(Si,Ti)+2Mo had the preferential dissolution of L12 compared to (L12 + Niss) mixture region at lower pH, while pitting attack occurred in (L12 + Niss) mixture region at neutral solution. For both intermetallic compounds, the magnitude of pitting and uniform attack decrease with increasing pH of solutions. From the immersion test and polarization curves, the corrosion resistance of Ni3(Si,Ti)+2Mo is lower than that of Ni3(Si,Ti), while the nickel alloy C-276 is the highest one at various pH of solutions. On the other hand, in the lower pH of solutions, the corrosion resistance of tested materials decreased significantly compared to those in neutral and higher pH of solutions

  2. The effect of pH on the corrosion behavior of intermetallic compounds Ni{sub 3}(Si,Ti) and Ni{sub 3}(Si,Ti) + 2Mo in sodium chloride solutions

    Energy Technology Data Exchange (ETDEWEB)

    Priyotomo, Gadang, E-mail: gada001@lipi.go.id; Nuraini, Lutviasari, E-mail: Lutviasari@gmail.com [Research Center for Metallurgy and Material, Indonesian Institute of Sciences, Kawasan PUSPIPTEK Gd.474, Setu, Tangerang Selatan, Banten 15314 (Indonesia); Kaneno, Yasuyuki, E-mail: kaneno@mtr.osakafu-u.ac.id [Department of Materials Science, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Sakai, Osaka 599-8531 (Japan)

    2015-12-29

    The corrosion behavior of the intermetallic compounds, Ni{sub 3}(Si,Ti) (L1{sub 2}: single phase) and Ni{sub 3}(Si,Ti) + 2Mo (L1{sub 2} and (L12 + Ni{sub ss}) mixture region), has been investigated using an immersion test, electrochemical method and surface analytical method (SEM; scanning electron microscope and EDAX: Energy Dispersive X-ray) in 0.5 kmol/m{sup 3} NaCl solutions at various pH. The corrosion behavior of nickel alloy C-276 was studied under the same experimental conditions as a reference. It was found that the uniform attack was observed on Ni{sub 3}(Si,Ti) for the immersion test at lower pH, while the pitting attack was observed on this compound for this test at neutral solution. Furthermore, Ni{sub 3}(Si,Ti)+2Mo had the preferential dissolution of L1{sub 2} compared to (L1{sub 2} + Ni{sub ss}) mixture region at lower pH, while pitting attack occurred in (L1{sub 2} + Ni{sub ss}) mixture region at neutral solution. For both intermetallic compounds, the magnitude of pitting and uniform attack decrease with increasing pH of solutions. From the immersion test and polarization curves, the corrosion resistance of Ni{sub 3}(Si,Ti)+2Mo is lower than that of Ni{sub 3}(Si,Ti), while the nickel alloy C-276 is the highest one at various pH of solutions. On the other hand, in the lower pH of solutions, the corrosion resistance of tested materials decreased significantly compared to those in neutral and higher pH of solutions.

  3. Plugging solution

    Energy Technology Data Exchange (ETDEWEB)

    Vagner, G.R.; Garaev, A.S.; Guzenko, L.P.; Khaber, N.V.; Kruglitskii, N.N.; Kurochkin, B.M.; Shumilov, V.A.

    1981-03-23

    Proposed is a plugging solution which contains cement, hydrophilic biosilica, polymer, and water, and which is distinguished by the fact that in order to increase the strength properties of the stone with simultaneous increase in its resistance to the effect of corrosive bed water under conditions of normal temperatures, as hydrophilic biosilica the solution contains carboxy aerosil or aminoethoxy aerosil, and as a polymer, carboxylate divinyl styrene latex and it also contains sodium with the following ingredient ratio, wt %: 63.47-66.08% cement, 0.66-1.28% carboxylate divinyl styrene latex, 1.26-1.32% sodium chloride, 0.22-0.36% carboxy aerosil or aminoethoxy aerosil, and the rest water. The plugging solution is distinguished by the fact that carboxy aerosil or aminoethoxy aerosil have a specific surface of 50-300 m/g.

  4. Benzalkonium Chloride Induced Bronchoconstriction in Patients with Stable Bronchial Asthma

    OpenAIRE

    Lee, Byoung Hoon; Kim, Sang-Hoon

    2007-01-01

    Background Although benzalkonium chloride (BAC)-induced bronchoconstriction occurs in patients with bronchial asthma, BAC-containing nebulizer solutions are still being used in daily practice in Korea. The aim of this study was to evaluate the effects of inhaled aqueous solutions containing BAC. Methods Thirty subjects with bronchial asthma and 10 normal controls inhaled up to three 600 µg nebulized doses of BAC using a jet nebulizer. FEV1 (forced expiratory volume at one second) was measured...

  5. Characterization and corrosion behavior of phytic acid coatings, obtained by chemical conversion on magnesium substrates in physiological solution; Caracterizacion y comportamiento frente a la corrosion de recubrimientos de acido fitico, obtenidos por conversion quimica, sobre substratos de magnesio en solucion fisiologica

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez-Alvarado, L. A.; Lomeli, M. A.; Hernandez, L. S.; Miranda, J. M.; Narvaez, L.; Diaz, I.; Garcia-Alonso, M. C.; Escudero, M. L.

    2014-10-01

    In order to improve the corrosion resistance of biodegradable magnesium and AZ31 magnesium alloy implants, a phytic acid coating has been applied on both substrates and their protective effect against corrosion has been assessed. The morphology and the chemical nature of the conversion coating were analyzed by SEM/EDX, XRD and FTIR. The spectra showed that the conversion coating was amorphous, and it was composed of Mg, O, and P on magnesium surface, along with Al, Zn and C on AZ31 alloy. The main coating components were chelate compounds formed by phytic acid and metallic ions. The corrosion resistance of bare and coated samples was evaluated by potentiodynamic polarization technique in Hank's solution at 37 degree centigrade. The results indicate that phytic acid conversion coatings provided a very effective protection to the magnesium substrates studied. (Author)

  6. Development of the Inventario de Comportamiento Escolar (IDCE) for Puerto Rican Children.

    Science.gov (United States)

    Bauermeister, Jose J.; And Others

    1987-01-01

    The "Inventario de Comportamiento Escolar" is a teacher rating inventory for the assessment of Puerto Rican children, particularly those with a behavior pattern indicative of attention deficit disorder, learning disabilities, or academic underachievement. (JHZ)

  7. Trastornos mentales y del comportamiento orgánico

    Directory of Open Access Journals (Sweden)

    Roberto Anselmo Ramos Valverde

    2014-11-01

    Full Text Available La personalidad es plurideterminada, integrada por factores biológicos, psicológicos y socioculturales en igual jerarquía funcional y concatenación dialéctica, concepción necesaria para comprender el origen y formación de los procesos psicológicos. (1 En el Tercer Glosario Cubano de Psiquiatría (GC-3 se define como trastorno orgánico a los síndromes psiquiátricos, cuyas manifestaciones actuales fundamentales son la consecuencia directa de una alteración anatomofisiológica conocida del encéfalo, que implica una merma intrínseca de su capacidad para servir de sostén a una actividad mental normal, hecho éste que lo diferencia de aquellas entidades, en que la armonía funcional del cerebro se ve alterada por una sobrecarga de estrés o un aprendizaje anormal, que bloquea las capacidades fundamentales del órgano gestor del psiquismo sin destruirlas. (2, 3 Se entiende por trastornos mentales y del comportamiento orgánicos al conjunto de síntomas o comportamientos identificables en la práctica clínica, que surgen como consecuencia de un daño tisular asentado en el cerebro o fuera de él, que afecta la fisiología del Sistema Nervioso Central (SNC y, con ella, los mecanismos de reflexión de la realidad. (3 Definir el concepto de trastornos mentales y del comportamiento orgánico y crear una nueva clasificación, teniendo en cuenta la gravedad de los síntomas de utilidad en la formación del médico general y como soporte bibliográfico para el residente de Psiquiatría, constituyó la motivación fundamental para la realización de este editorial. (3 Trastornos mentales y del comportamiento orgánico menores constituyen un conjunto de entidades nosológicas, cuya sintomatología causa malestar y afecta la adaptación creadora del sujeto al medio, teniendo en cuenta su carácter persistente e irreversible. En muchos casos, no provocan distorsión grave de la realidad objetiva, pueden ser orgánicos, propiamente dicho, si la lesi

  8. Electrochemical chloride ion detection technique by using Pt electrode in high temperature water

    International Nuclear Information System (INIS)

    Chloride ion is a representative chemical species causing the corrosion failure of structural materials. For detecting chloride ions in a high temperature solution, the potentio-dynamic polarization and potential transient technique were performed with a Pt electrode. From the polarization behaviour, it was recognized that there is a potential region forming a stable Pt oxide layer to blockade the oxidation reaction of dissolved hydrogen. Since the presence of chloride ions affect the growth of an oxide layer on the metal surface, the potential transient technique was used to investigate the interference of chloride ions for formation of the Pt oxide layer by repeating apply the potential between oxide-free and oxide forming potentials. As a result, the initial oxidation current of dissolved hydrogen appeared to increase with an increase in the chloride ion concentration of the test solutions, and the time for reaching the limiting oxidation current was delayed. From the oxidation current of dissolved hydrogen, we could detect chloride ions down to 2.8 x 10-5 M in high temperature solutions. Consequently, the oxidation current of dissolved hydrogen could be an indicator of chloride ions, because the formation of the Pt oxide layer is sensitively interfered with the chloride ions. (authors)

  9. Venous uptake of 201Tl as thallous chloride

    International Nuclear Information System (INIS)

    Thallium-201, injected as thallous chloride, has been found to adhere to or be taken up by the vein into which it is injected, permitting images to be obtained of human veins up to 4 h following injection. A digoxin-insensitive rat vein model also retained 201Tl but for shorter periods of time. 201Tl uptake is independent of the solution into which it is introduced, whether 5% dextrose or 0.9% sodium chloride. This technique permits multiple delayed views of normal veins to be obtained but is of uncertain value in the evaluation of thrombophlebitis of the calf because of rather poor resolution and high cost. (author)

  10. TESTING OF 304L STAINLESS STEEL IN NITRIC ACID ENVIRONMENTS WITH FLUORIDES AND CHLORIDES

    Energy Technology Data Exchange (ETDEWEB)

    Mickalonis, J.

    2010-10-04

    Impure radioactive material processed in nitric acid solutions resulted in the presence of chlorides in a dissolver fabricated from 304L stainless steel. An experimental program was conducted to study the effects of chloride in nitric acid/fluoride solutions on the corrosion of 304L stainless steel. The test variables included temperature (80, 95, and 110 C) and the concentrations of nitric acid (6, 12, and 14 M), fluoride (0.01, 0.1, and 0.2 M) and chloride (100, 350, 1000, and 2000 ppm). The impact of welding was also investigated. Results showed that the chloride concentration alone was not a dominant variable affecting the corrosion, but rather the interaction of chloride with fluoride significantly affected corrosion.

  11. Electrochemical Analysis of the Concentration of Cupric Chloride Complex in CuCl2-NaCl Solution at Room Temperature%室温氯化铜-氯化钠溶液中铜氯络合物浓度的电化学分析

    Institute of Scientific and Technical Information of China (English)

    张艳清; 李和平; 刘庆友; 徐丽萍; 张磊

    2011-01-01

    The electrochemical reaction mechanism of CuCl2-NaCl weak acid solution was studied by the Tafel method and linear potential sweep voltammetry at room temperature. The exchange current densities at different concentration ratios of CuCl2-NaCl solution were obtained from their polarization curves and the coordination number of the electrochemical reduction complex was calculated from electrochemical reaction order method. The electrochemical reduction on Pt electrode was further studied by linear potential sweep voltammetry. Finally, the concentration of the electrochemical reduction complex ion was calculated when the procedure was reversed. The results were shown that [ CuCl ]+ is the main cupric chloride complex in solution and the one for electrochemical reduction on Pt electrode. Two one-electron reduction steps of the copper chloride complex were observed on the surface of the Pt electrode. The first step was a one-electron-transfer reversible reduction process. The electrochemical reaction orders of [ CuCl ]+ and Cu in the system were both level one. In 4. 000 mol/L NaCl + 0. 100 mol/L CuCl2 solution, the concentration of the electrochemical reduction reactant ( [ CuCl ]+ ) was 0. 086 mol/L. The results provided important experimental evidences for electrochemical reduction mechanism of Cu + in aqueous solutions with highly concentrated chloride ions.This work can also be used as a reference for electrochemical analysis of dissolved metal complex in the fields ofmetallurgy, geology, geochemistry in the future.%运用Tafel极化曲线和线性电势扫描法研究了常温弱酸性CuCl2-NaCl溶液中铜氯络合物体系的电化学放电机理.通过测量不同浓度配比的CuCl2-NaCl溶液的极化曲线得到各自的交换电流密度,然后根据电化学反应级数法计算直接在电极上放电的Cu(Ⅱ)-Cl络合物的配位数.并且运用线性电势扫描法进一步研究了此络合物在铂电极上的还原反应,在体系可逆的情况下

  12. Disposable sensor for electrochemical determination of chloride ions.

    Science.gov (United States)

    Bujes-Garrido, Julia; Arcos-Martínez, M Julia

    2016-08-01

    This work describes the development of a new, simple and inexpensive method for the determination of chloride ions, by using voltammetric disposable sensors. The sensor includes three screen printed electrodes: a working, an auxiliary (both carbon based paste electrodes), and a pseudo-reference Ag/AgCl paste based electrode. Since the presence of chloride ions in the solution modifies the equilibrium potential of Ag/AgCl electrode, the concentration of this analyte has been determined through the systematic shift of the voltammetric peak potential of a control species such as potassium ferricyanide, potassium ferrocyanide or ferrocenemethanol. These control species can be used in solution or mixed into the carbon paste of the working screen printed electrode. In order to characterize the developed methods, reproducibility, repeatability and detection limit of the sensors were calculated in each case. Reproducibility values below 3% (n=5) were obtained. When ferrocenemethanol was used as control species, the lowest quantity of chloride ions detected was 10.0mM. A comprehensive study of interfering ions was also carried out. These sensors were successfully applied to determine the chloride content in sea water and in a commercial saline solution sample. PMID:27216668

  13. Validación del cuestionario de auto-reporte de comportamiento antisocial en adolescentes: CACSA

    Directory of Open Access Journals (Sweden)

    Paula Alarcón Bañares

    2010-12-01

    Full Text Available El estudio tiene por objetivo presentar la validación de un instrumento formulado racionalmente para evaluar, mediante auto-reporte, el comportamiento social en adolescentes chilenos (CACSA y describir el comportamiento social de dos grupos: adolescentes escolarizados (N=1914 y adolescentes infractores de ley (N=264. El cuestionario posee 56 ítemes que exploran tres dimensiones generales, a Comportamiento Prosocial (CPRO, b Comportamiento Antisocial Total (CAT; y c Víctima de Abuso de Poder (VAP; CAT contiene seis dimensiones específicas: Delitos (D, Transgresiones Contra la Propiedad (TPRO, Transgresiones Contra las Personas (TPER, Comportamiento Abusivo con Pares (CAP, Consumo de Alcohol y Drogas (OHD; y Transgresiones Sociales Leves (TSL. El estudio incluye también una escala de deseabilidad social y otra actitudinal. Los resultados revelan importantes fortalezas psicométricas del instrumento y capacidad de discriminación entre adolescentes escolarizados e infractores de ley. Se discute la importancia de reconocer por auto-reporte la prevalencia de comportamientos antisociales y la relación entre conductas prosociales y antisociales en adolescentes chilenos.

  14. Mejorar el trabajo en equipo: ambidiestría, comportamiento integrador y aprendizaje cooperativo

    Directory of Open Access Journals (Sweden)

    María Iborra

    2012-09-01

    Full Text Available El objetivo de este estudio es argumentar y demostrar qué trabajo en equipo deben aprender los futuros profesionales de la dirección de empresas y cómo pueden aprenderlo. Respecto a las características del trabajo en equipo que deben aprender los futuros directivos, se argumenta que un comportamiento integrador permite alcanzar mayores niveles de ambidiestría, es decir, incrementar la capacidad de realizar simultáneamente exploración y explotación de conocimiento, eficiencia e innovación. El estudio profundiza en la relación entre las metodologías docentes utilizadas en el aula y la mejora del comportamiento integrador de los profesionales cuando trabajan en equipo. El comportamiento integrador en un equipo depende de la calidad y cantidad de información intercambiada, la colaboración alcanzada en el equipo, y la medida en que las decisiones se toman conjuntamente. En este trabajo se defiende la relación positiva entre la metodología docente de aprendizaje cooperativo y el comportamiento integrador de los estudiantes en los equipos de trabajo. Mediante un estudio realizado con 327 estudiantes de enseñanza universitaria, se demuestra que los equipos de trabajo que han utilizado aprendizaje cooperativo alcanzan mayores niveles de comportamiento integrador. Igualmente se demuestra que el comportamiento integrador de los miembros del equipo se asocia con una superior ambidiestría.

  15. ESTABLECIMIENTO DE METAS, COMPORTAMIENTO Y DESEMPEÑO

    Directory of Open Access Journals (Sweden)

    2000-01-01

    Full Text Available Existen varios enfoques motivacionales que se inclinan más hacia las causas próximas del comportamiento que hacia las necesidades y características (la suposición básica es que las personas se sienten más motivadas cuando sus valores, sus necesidades y su carácter se ajustan al contexto laboral y organizacional que cuando no lo están. Los enfoques de causas próximas al comportamiento se centran principalmente en las creencias que la gente tiene acerca de su propio desempeño, como por ejemplo lo que están tratando de hacer, desean hacer, piensan que pueden hacer, o realmente esperan hacer. Estos enfoques específicos se basan en el supuesto de que las creencias propias acerca de las actividades futuras de una persona (y las propias interpretaciones de actividades pasadas influyen en sus acciones en el presente. En esta última categoría se incluyen las teorías del establecimiento de metas, la auto-eficacia y las expectativas. Estas teorías se asemejan en cuanto a que cada concepto requiere que la gente piense y juzgue su desempeño futuro con base en las experiencias pasadas y su valoración del momento. Las metas tienden a reflejar lo que la gente desea hacer, la auto-eficacia refleja lo que la gente piensa que puede hacer y las expectativas reflejan el “mejor estimativo” que tiene la gente sobre las consecuencias de sus acciones.En este documento se revisan criterios para comprender la relación entre el establecimiento de metas y el desempeño, incluyendo definiciones, diferentes medidas, perspectivas, enfoques, mediadores y moderadores, sobre diferentes investigaciones prácticas acerca del establecimiento de metas. Finalmente, este escrito proporciona la base para propuestas de investigación específicas concernientes a la confiabilidad y validez de la medida y la posibilidad de generalizar esta teoría para distintas tareas (por ejemplo, labores complejas, dificultad de las metas, trabajos novedosos, para diversas

  16. Comportamiento Frente a la Corrosión en Ambiente Marino de Acero Galvanizado y Acero Galvanizado Pintado (Duplex Corrosion Behaviour of Galvanized and Coated Galvanized Steel (Duplex in Marine Environment

    Directory of Open Access Journals (Sweden)

    R.M. Vera

    2005-01-01

    Full Text Available En este estudio se evaluó el comportamiento frente a la corrosión en medio marino de acero galvanizado y acero galvanizado pintado (Duplex haciendo uso de ensayos electroquímicos y acelerados de laboratorio. Las medidas electroquímicas consideraron potencial de corrosión a circuito abierto, curvas de polarización y polarización potenciostática en cloruro de sodio 0.1M. Los ensayos acelerados se realizaron en cámara de niebla salina y con el método Cebelcor. El grado de ataque del material se observó por microscopia electrónica de barrido. Los resultados muestran que el sistema Duplex presenta un mejor comportamiento frente la corrosión en medio de cloruros que el acero galvanizado, aumentando su durabilidad en el tiempo.This study evaluated the resistence to corrosion of galvanized and painted galvanized (Duplex steel in a marine environment using electrochemical and accelerated laboratory essays. The electrochemical measurements included open circuit potential, polarization curves, and potentiostatic polarization in 0.1M sodium chloride. The accelerated essays were carried out in a saline fog chamber and also using the Cebelcor method. The degree of corrosion attack of the material was observed by scanning electronic microscopy. The results show that the Duplex system presents a better behaviour against corrosion in chloride media than galvanized steel, increasing its useful life.

  17. Species Transformation and Electrokinetic Properties of Hydroxyl Polymeric Aluminum-ferric Chloride Solutions%聚磷氯化铝铁溶液形态转化及电动特性

    Institute of Scientific and Technical Information of China (English)

    曹福; 凌燕; 顾竟禹

    2011-01-01

    Species transformation of typical polymeric phosphato aluminum-ferric chloride (PPAFC) was studied with[Al+ Fe]-Ferron timed complex colorimetric method. Results showed that the species transformation mainly depends upon P/(Al+ Fe), OH/(Al+Fe) and nAl/nFe. Dominant species of PPAFC transform each other directly. The turbidity removing efficiency of PPAFC was investigated by jar test in the simulated water. Electrokinetic properties of PPAFC were tested by zeta potential measurement. Electrokinetic properties of PPAFC were done with different P/(Al +Fe), OH/(Al +Fe) and nAl/nFe. The experimental results showed that PPAFC polymers coagulate in water by charge neutralization, adsorption bridging and precipitation catching mechanisms. The better thc synthesis of the three mechanisms is, thc better the coagulation effects.%采用[Al+Fe]-Ferron逐时络合比色法研究了典型聚磷氯化铝铁溶液的形态转化,结果表明,聚磷氯化铝铁的形态转化主要由P/(Al+Fe)、OH/(Al+Fe)和nAl/nFe等因素决定,聚磷氯化铝铁的形态转化特征是优势形态之间的转变.通过对模拟悬浊水样的絮凝实验,对其除浊性能进行了考察,通过测定zeta电位对其水解物的电动特性进行了研究,结果表明,聚磷氯化铝铁水解聚合产物的电动特性与P/(Al+Fe)、OH/(Al+Fe)和nAl/nFe的变化密切相关,聚磷氯化铝铁是通过电中和、吸附架桥和沉淀网捕作用起混凝作用的,三种作用的综合能力越强,其混凝效果就越好.

  18. Evaluation of chloride/bicarbonate. Exchange in the human colon in vivo.

    OpenAIRE

    Davis, G R; Morawski, S. G.; Santa Ana, C A; Fordtran, J S

    1983-01-01

    During perfusion of a plasma-like solution, colonic absorption rate of chloride was much higher than the secretion rate of bicarbonate (34 vs. 3.5 meq/h, respectively). This might suggest that anion exchange (Cl/HCO3) accounts for only a small fraction of total chloride absorption. However, if the colon absorbs as well as secretes bicarbonate, this reasoning would underestimate the magnitude of the anion exchange. To see if the colon absorbs bicarbonate, we perfused a chloride-free solution (...

  19. Inhibition of Chloride Induced Crevice Corrosion in Alloy 22 by Fluoride Ions

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-10-09

    Alloy 22 (N06022) is highly resistant to localized corrosion. Alloy 22 may be susceptible to crevice corrosion in pure chloride (Cl{sup -}) solutions under aggressive environmental conditions. The effect of the fluoride (F{sup -}) over the 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 and pH 6. The range of chloride concentration [Cl{sup -}] was 0.001 M {le} [Cl{sup -}] {le} 1 M and the range of molar fluoride to chloride ratio [F{sup -}]/[Cl{sup -}] was 0.1 {le} [F{sup -}]/[Cl{sup -}] {le} 10. Results showed that Alloy 22 was susceptible to crevice corrosion in all the pure chloride solutions but not in the pure fluoride solutions. Fluoride ions showed an inhibitor behavior only in mixtures with a molar ratio [F{sup -}]/[Cl{sup -}] > 2. For mixtures with a molar ratio [F{sup -}]/[Cl{sup -}] of 7 and 10 the inhibition of crevice corrosion was complete.

  20. A study of Trace Gold Chloride and Hydroxide Speciation in Weak Alkaline Solution by Ion Chromatography-Inductively Coupled Plasma Mass Spectrometry%离子色谱电感耦合等离子体质谱研究痕量氯金酸在弱碱性体系中金(Ⅲ)的形态

    Institute of Scientific and Technical Information of China (English)

    刘德晔; 朱醇; 马永建

    2012-01-01

    A method based on ion chromatography-inductively coupled plasma mass spectrometry(IC-ICP-MS) was developed to study trace gold chloride and hydroxide speciation in weak alkaline solu-tion. The results revealed that, the main compounds in weak alkaline solution were [AuCl2(OH)2]~ and [AuCKOH)3]-when the total Au mass was between 4. 0 30 ng. Unlike high HAuCl4 4H2O concentration, trace [AuCl2 (OH)2]~ could exist between pH 7. 0 to 10. 0, at least. Additional chlo-ride brought promotion to [AuCl2(OH)2]~ and reduction to CAuCl(OH)3]~. When pH was 7. 0 or chloride concentration was above 0. 050 mol/L, AuflE) would generate a compound which could not be flushed out of chromatography system. According to hydrolysis process. that compound was deduced as [AuCl3(OH)]-. The equilibrium constant K3 of [AuCl2(OH)2]- + OH ←[AuCl (OH)3]-+Cl always changed with pH values and chloride concentrations. Therefore, there might exist other factor to influence the trace Au(Ⅲ) hydrolysis.%采用离子色谱电感耦合等离子体质谱联用方法研究弱碱性体系下痕量氯金酸中Au(Ⅲ)的形态.结果表明:在弱碱性条件下,总金含量在4.0~30 ng之间,Au(Ⅲ)主要以[AuCl2( OH)2]-和[AuCl(OH)3]-的形式存在.与较高含量的氯金酸溶渡相比,痕量氯金酸溶液中的[AuCl2(OH)2]-至少可以在pH 7.0~10.0范围内存在.溶液外加的Cl-可使[AuCl2 (OH)2]-含量升高同时降低[AuCl (OH)3]-含量;当pH=7.0或Cl-浓度高于0.050 mol/L,会产生不随色谱流出的金络合物,根据水解过程推断该络合物为[AuC13 (OH)]-.在pH 8.0~10.0,Cl-浓度在0.000~0.020 mol/L时,[AuCl2(OH)2]-+OH-=[AuCl (OH)3]-+Cl-的水解平衡常数为不定值,说明痕量氯金酸的水解不仅受pH值和Cl-浓度影响,还受其它因素影响.

  1. Chloride in vesicular trafficking and function.

    Science.gov (United States)

    Stauber, Tobias; Jentsch, Thomas J

    2013-01-01

    Luminal acidification is of pivotal importance for the physiology of the secretory and endocytic pathways and its diverse trafficking events. Acidification by the proton-pumping V-ATPase requires charge compensation by counterion currents that are commonly attributed to chloride. The molecular identification of intracellular chloride transporters and the improvement of methodologies for measuring intraorganellar pH and chloride have facilitated the investigation of the physiology of vesicular chloride transport. New data question the requirement of chloride for pH regulation of various organelles and furthermore ascribe functions to chloride that are beyond merely electrically shunting the proton pump. This review surveys the currently established and proposed intracellular chloride transporters and gives an overview of membrane-trafficking steps that are affected by the perturbation of chloride transport. Finally, potential mechanisms of membrane-trafficking modulation by chloride are discussed and put into the context of organellar ion homeostasis in general. PMID:23092411

  2. Steel corrosion in anoxic mediums with high chloride concentrations

    International Nuclear Information System (INIS)

    Carbon steels are widely used in contact with chloride containing mediums, however most of the literature reports corrosion problems in solutions in contact with air, for example, sea water. There are other applications where the steel is in contact with freshwater in the absence of oxygen as is the case with materials for nuclear repositories or in petroleum production. These mediums can have varied composition but their corrosivity is usually related to the concentration of chlorides. There are no systematic studies in the literature about the influence of high chloride concentrations on the speed of steel corrosion for carbon steels in the absence of oxygen. Some work has been done using Raman and XPS spectroscopy, but these techniques have been carried out ex situ in samples submitted to the action of high chloride concentrations. This results in the appearance of corrosion products on the metal surface due to the oxidation of the surface from exposure to air before and during the use of these techniques, generating confusing and uncertain data. The lack of reliable data is due to the difficulty of applying these techniques in situ under very low oxygen conditions (less than 10 ppb) without allowing any air into the system. Since there are no studies in the literature about the influence of high concentrations of chloride on the corrosion speed of carbon steels in the absence of oxygen, this work aims to generate experimental data to evaluate the influence of high concentrations of this anion on the corrosion speed of steel under anoxic conditions. The corrosivity of each solution was evaluated using electrochemical techniques such as corrosion potential, corrosion speed, anodic and cathodic polarization curves, cyclic voltammetries and electrochemical impedance spectroscopy to study the oxidation-reduction processes that occur with specific temperature, pH and chloride concentration conditions. Concentrated solutions of sodium chloride (50,000, 100,000 and 180

  3. Comportamiento Organizacional - Una Conceptualización Integral

    Directory of Open Access Journals (Sweden)

    Eustoquio R. García

    2015-05-01

    Full Text Available El presente trabajo describe  el modelo ADIE que integra los enfoques micro, macro y post empresarial,  para  describir y evaluar el comportamiento de las organizaciones, a partir de dos elementos fundamentales: las necesidades de la organización  (Adaptación, Integración y Ejecución y las actividades que ésta debe realizar para satisfacerlas (Planificación, Innovación, Organización, Regulación, Control y Estimulación.  Se trata de un Modelo de Contingencia ya que implica una estrecha interrelación entre la organización y el ambiente donde ésta funciona. La experiencia ganada en su utilización demuestra que puede tener varios usos: como herramienta educativa (desarrollo gerencial, como herramienta de consulta, o como esquema de diagnóstico, entre otros.  La  recolección de la información, esencial para fines de diagnóstico, se puede efectuar mediante entrevistas individuales o mediante la aplicación de cuestionarios especialmente diseñados de acuerdo a las dimensiones del Modelo ADIE. El cuestionario aplicado que describe este trabajo contiene  treinta ítems (cinco por cada actividad en forma de escala de diez puntos. La experiencia ha demostrado que el instrumento tiene una alta validez aparente.

  4. Prácticas y comportamientos sexuales en estudiantes universitarios

    Directory of Open Access Journals (Sweden)

    JUAN MANUEL OSPINA DÍAZ

    2007-12-01

    Full Text Available Introducción: Desde 1995 se validaron estudios de tipo descriptivo, como necesidad de investigar previamente a las intervenciones educativas, dada la pluralidad cultural que descalifica modelos de aplicación universal en lo referente a la educación sexual. Objetivo: Describir prácticas y comportamientos sexuales en estudiantes universitarios de la UPTC de Tunja. Métodos: Estudio de corte transversal, muestreo secuencial, muestra de 764 estudiantes. En Epiinfo 2002® se estiman frecuencias, cruce de variables, porcentajes. Resultados: Edad promedio: 20,4 años; 56,7% mujeres; 82,8% clase media-baja; 79,7% católico o cristiano; para resolver intimidades, 11,4% confía en el padre, 33,5% en la madre; apenas 36,2% tiene 100% de certeza de evitar un embarazo no deseado y27%,de contraeruna ETS. 61,2% considera necesario incrementar sus conocimientos sexuales; 40,5% ha tenido al menos una laguna alcohólica; 30% ha tenido sexo no deseado, al menos una vez, bajo el efecto del alcohol. Razón global de fertilidad: 25,4%. 45,3% de embarazos termina en aborto provocado. Conclusiones: Problemas más relevantes: altas tasas de fecundidad, natalidad y aborto provocado, elevado consumo de alcohol.

  5. Comportamiento sexual y erotismo en estudiantes universitarios, Cali, Colombia

    Directory of Open Access Journals (Sweden)

    Lina María García

    2011-09-01

    Full Text Available Objetivo: Identificar los principales componentes de pensamiento y prácticas eróticas de los estudiantes de la Universidaddel Valle, Campus San Fernando.Método: Se realizó un estudio descriptivo, durante los años 2008 y 2009 con 1,120 estudiantes estudiantes de dosfacultades de una universidad pública en el Valle del Cauca, Colombia, para evaluar sus necesidades en salud sexual yreproductiva.Resultados: Se diseñó un sistema informático para el estudio. Fueron 695 (62% mujeres con una edad media de 20 años,con alta proporción de niveles socioeconómicos bajos. La edad media de inicio de relaciones sexuales fue 16 años sindiferencias por nivel educativo; 50% tuvo su primer coito antes de la adolescencia final y 42% ha tenido entre dos y cincoparejas sexuales. Las mujeres disfrutan menos las relaciones sexuales (p=0.022 con mayor proporción de relaciones extraparejaen los hombres (p<0.001.Conclusiones: Los hombres adoptan con mayor frecuencia comportamientos de riesgo en las prácticas eróticas tales comomayor número de parejas sexuales, mayor frecuencia de infidelidad, reportaron mayor placer durante las relaciones sexoeróticas.

  6. Medios electrónicos y comportamiento antisocial en adolescentes

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    Carolina Bringas

    2008-01-01

    Full Text Available El comportamiento antisocial o inadaptado viene determinado por diversas variables, tanto individuales como contextuales, que pueden actuar como factores de riesgo. Uno de estos factores es el uso de los medios de comunicación electrónicos, especialmente de las más nuevas tecnologías, aunque diversos estudios aseveran que este consumo no ejerce una responsabilidad exclusiva en la adquisición de conductas antisociales por parte de los adolescentes. Utilizando una muestra de 331 jóvenes de ambos sexos, y con edades que oscilan entre los 14 a 20 años, este estudio pretende, por un lado, y a través del modelo de redes neuronales, comprobar el poder predictivo de las variables de personalidad, motivacionales y de consumo de medios electrónicos en la conformación de conductas antisociales y, por otro lado, identificar el rol que cada variable tiene en la construcción del modelo que permita predecir los actos antisociales.

  7. A spectroscopic study of uranium species formed in chloride melts

    International Nuclear Information System (INIS)

    The chlorination of uranium metal or uranium oxides in chloride melts offers an acceptable process for the head-end of pyrochemical reprocessing of spent nuclear fuels. The reactions of uranium metal and ceramic uranium dioxide with chlorine and with hydrogen chloride were studied in the alkali metal chloride melts, NaCl-KCl at 973K, NaCl-CsCl between 873 and 923K and LiCl-KCl at 873K. The uranium species formed therein were characterized from their electronic absorption spectra measured in situ. The kinetic parameters of the reactions depend on melt composition, temperature and chlorinating agent used. The reaction of uranium dioxide with oxygen in the presence of alkali metal chlorides results in the formation of alkali metal uranates. A spectroscopic study, between 723 and 973K, on their formation and their solutions was undertaken in LiCl, LiCl-KCl eutectic and NaCl-CsCl eutectic melts. The dissolution of uranium dioxide in LiCl-KCl eutectic at 923K containing added aluminium trichloride in the presence of oxygen has also been investigated. In this case, the reaction leads to the formation of uranyl chloride species. (author)

  8. AFM study of steel corrosion in aqueous solutions in concrete

    Directory of Open Access Journals (Sweden)

    Díaz-Benito, B.

    2011-03-01

    Full Text Available Early corrosion stages are studied in carbon steel by means of a solution simulating that contained in concrete pores. Non-carbonated solution contains 5% NaCl. The atomic force microscopy (AFM technique is used to study material performance after different immersion times (up to 48 h. Obtained data are compared to electrochemical ones (corrosion potential and polarization resistance. Analysis of images and roughness evolution along time shows that steel initially tends to reach passivity, although the passive layer rapidly loses its protective character due to chloride attack.

    Este trabajo estudia los primeros estados de la corrosión de un acero al carbono en una disolución que simula la existente en los poros del hormigón, sin carbonatar, con un 5% de NaCl. Para ello, se ha empleado la técnica de microscopía de fuerza atómica (AFM, estudiando el comportamiento del material tras diferentes tiempos de inmersión, hasta 48 h, en la disolución. Estos datos se comparan con datos electroquímicos (potencial de corrosión y resistencia de polarización. El análisis de las imágenes y la evolución de la rugosidad con el tiempo muestran que el acero tiende inicialmente a pasivarse, pero la capa pasiva pierde rápidamente su carácter protector debido al ataque de los cloruros.

  9. Radiolytic preparation of anhydrous tin (2) chloride

    Science.gov (United States)

    Philipp, W. H.; Marsik, S. J.

    1973-01-01

    Anhydrous tin (2) chloride (SnCl2) is prepared by radiolysis with high energy electrons of a tin (4) chloride (SnCl4) solution in heptane. The SnCl4 is reduced to insoluble SNCl2. The energy yield, G(SnCl2), molecules of SnCl2, produced per 100 eV, increases with SnCl4 concentration from 1.6 at 0.15 M SnCl4 to 3.1 at 3.0 M SnCl4. Other parameters such as temperature total dose and beam current have little influence on G(SnCl2). The method may be used to prepare other metal halides if the higher valence, more covalent metal halide is soluble in aliphatic hydrocarbons and the lower more ionic metal halide is insoluble. The reaction mechanism is discussed; the radiolysis of both heptane and SnCl4 is involved. At high SnCl4 concentration G(SnCl2) appears to be limited by the yield of SnC13 radicals.

  10. Caracterización de adolescentes de sexo masculino en relación al comportamiento antisocial

    OpenAIRE

    André Vilela Komatsu, Brasil.; Marina Rezende Bazon, Brasil.

    2015-01-01

    (analítico): El objetivo de este estudio es caracterizar los comportamientos divergentes e infraccionales en muestras de adolescentes brasileños, compuestas por 133 adolescentes de la población en general, reclutados de las escuelas públicas, y otros 60 adolescentes judicializados, reclutados de programas de medida judicial. Los participantes respondieron a un cuestionario de comportamiento juvenil, incluyendo comportamientos divergentes y delictivos. Resultados: la mayoría de los adolescente...

  11. Effects of vascular infusion with a solution of saccharides; sodium chloride; phosphates; and vitamins C, E, or both on carcass traits, Warner-Bratzler shear force, and palatability traits of steaks and ground beef.

    Science.gov (United States)

    Yancey, E J; Dikeman, M E; Addist, P B; Katsanidis, E; Pullen, M

    2002-07-01

    Three groups of 12 high percentage Charolais steers were slaughtered on three dates. Steers (n = 27) were infused immediately after exsanguination at 10% of BW with a solution containing saccharides, NaCl, and phosphates (MPSC solution; MPSC, Inc., St. Paul, MN) plus either 500 ppm vitamin C (MPSC+C), 500 ppm vitamin E (MPSC+E), or 500 ppm vitamin C plus 500 ppm vitamin E (MPSC+C+E). Noninfused controls (CON) were 9 steers. The longissimus thoracis (LT), semitendinosus (ST), and quadriceps femoris muscles were removed at 48-h postmortem, vacuum-packaged, and aged until 14-d postmortem. Steaks 2.54-cm thick were cut from the LT and ST. The quadriceps was utilized for ground-beef production. Infused steers had higher dressing percentages and heavier heart and liver weights (P 0.05) on USDA yield and quality-grade traits, LT and ST Warner-Bratzler shear force, descriptive-attribute traits, and freshly cooked steak flavor-profile traits. Vascular infusion had little effect on the flavor-profile traits of warmed-over steaks. Therefore, the results of our study indicate that vascular infusion with vitamins C, E, or C plus E can increase dressing percentage and organ weights, but have minimal effects on descriptive-attribute and flavor-profile sensory panel ratings. PMID:12162658

  12. 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)

  13. 1,5-Diaminotetrazolium chloride

    Directory of Open Access Journals (Sweden)

    Ling-Qiao Meng

    2010-04-01

    Full Text Available The title compound, CH5N6+·Cl−, crystallized with two indepedent 1,5-diaminotetrazolium cations and two independent chloride anions in the asymmetric unit. In the crystal, there are a number of N—H...Cl hydrogen-bonding interactions, which generate a three-dimensional network.

  14. Photonic crystal fiber based chloride chemical sensors for corrosion monitoring

    Science.gov (United States)

    Wei, Heming; Tao, Chuanyi; Krishnaswamy, Sridhar

    2016-04-01

    Corrosion of steel is one of the most important durability issues in reinforced concrete (RC) structures because aggressive ions such as chloride ions permeate concrete and corrode steel, consequently accelerating the destruction of structures, especially in marine environments. There are many practical methods for corrosion monitoring in RC structures, mostly focusing on electrochemical-based sensors for monitoring the chloride ion which is thought as one of the most important factors resulting in steel corrosion. In this work, we report a fiber-optic chloride chemical sensor based on long period gratings inscribed in a photonic crystal fiber (PCF) with a chloride sensitive thin film. Numerical simulation is performed to determine the characteristics and resonance spectral response versus the refractive indices of the analyte solution flowing through into the holes in the PCF. The effective refractive index of the cladding mode of the LPGs changes with variations of the analyte solution concentration, resulting in a shift of the resonance wavelength, hence providing the sensor signal. This fiber-optic chemical sensor has a fast response, is easy to prepare and is not susceptible to electromagnetic environment, and can therefore be of use for structural health monitoring of RC structures subjected to such aggressive environments.

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

    Directory of Open Access Journals (Sweden)

    R. C. Boeira

    2004-10-01

    Full Text Available Atualmente, alguns laboratórios de análise de solo determinam Al, Ca e Mg trocáveis em extratos de KCl 1 mol L-1 e K e Na na solução extratora Mehlich-1, também usada na extração de fósforo. Outros laboratórios, que empregam a resina trocadora de ânions para P, avaliam também Ca, Mg e K no extrato, não sendo possível determinar Al e Na. Dessa forma, achou-se oportuno avaliar a extração com NH4Cl 1 mol L-1 na determinação simultânea dos cinco cátions trocáveis: Al, Ca, Mg, K e Na, em comparação aos extratores KCl e Mehlich-1. Utilizaram-se amostras coletadas em áreas de cultivo de fruteiras irrigadas da região Nordeste e na área experimental da Embrapa Meio Ambiente em Jaguariúna (SP. Os métodos utilizados foram: (a extração simultânea dos cinco cátions com NH4Cl 1 mol L-1, e (b extração de Ca, Mg e Al com KCl 1 mol L-1, e de K e Na com o extrator Mehlich-1. A solução de NH4Cl 1 mol L-1 apresentou maior capacidade de extração de Mg do solo do que a solução de KCl 1 mol L-1; as duas soluções se equivaleram quanto à capacidade de extração de Ca e de Al. A solução de NH4Cl extraiu mais K e Na do que a solução Mehlich-1. Conclui-se que a solução de NH4Cl é uma opção conveniente para a extração de Al, Ca, Mg, K e Na trocáveis do solo.Currently, part of the soil testing laboratories of Brazil determine exchangeable Al, Ca, and Mg in a 1 mol L-1 KCl soil extract and exchangeable sodium and potassium in the Mehlich-1 soil extract, which is also used for phosphorus extraction. Other laboratories use an anion exchange resin for P and also determine Ca, Mg and K in the same extract, while Al and Na cannot be determined. For this reason, it was considered a good opportunity to evaluate the simultaneous extraction of the five exchangeable cations: Al, Ca, Mg, K, and Na in a 1 mol L-1 NH4Cl solution, and compare the results with those obtained with potassium chloride and Mehlich-1 extractants. The soil

  16. 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

  17. The impact of sulphate and magnesium on chloride binding in Portland cement paste

    International Nuclear Information System (INIS)

    The effect of magnesium and sulphate present in sea water on chloride binding in Portland cement paste was investigated. Ground well hydrated cement paste was exposed to MgCl2, NaCl, NaCl + MgCl2, MgSO4 + MgCl2 and artificial sea water solutions with a range of concentrations at 20 °C. Chloride binding isotherms are determined and pH of the solutions were measured. A selection of samples was examined by SEM-EDS to identify phase changes upon exposure. The experimental data were compared with calculations of a thermodynamic model. Chloride binding from sea water was similar to chloride binding for NaCl solutions. The magnesium content in the sea water lead to a slight decrease in pH, but this did not result in a notable increase in chloride binding. The sulphate present in sea water reduces both chloride binding in C–S–H and AFm phases, as the C–S–H incorporates more sulphates instead of chlorides, and part of the AFm phases converts to ettringite

  18. Impact of the associated cation on chloride binding of Portland cement paste

    International Nuclear Information System (INIS)

    Well hydrated cement paste was exposed to MgCl2, CaCl2 and NaCl solutions at 20 °C. The chloride binding isotherms for free chloride concentrations ranging up to 1.5 mol/l were determined experimentally. More chlorides were found to be bound when the associated cation was Mg2 + or Ca2 + compared to Na+. The chloride binding capacity of the paste appeared to be related to the pH of the exposure solution. In order to explain the cation dependency of the chloride binding a selection of samples was investigated in detail using experimental techniques such as TG, XRD and SEM–EDS to identify the phases binding the chlorides. The experimentally obtained data were compared with the calculations of a thermodynamic model, GEMS. It was concluded that the measured change in chloride binding depending on the cation was mainly governed by the pH of the exposure solution and thereby the binding capacity of the C-S-H

  19. The impact of sulphate and magnesium on chloride binding in Portland cement paste

    Energy Technology Data Exchange (ETDEWEB)

    De Weerdt, K., E-mail: klaartje.d.weerdt@ntnu.no [Department of Structural Engineering, Norwegian University of science and Technology, Trondheim (Norway); SINTEF Building and Infrastructure, Trondheim (Norway); Orsáková, D. [Department of Civil Engineering, Technical University of Brno, Brno (Czech Republic); Geiker, M.R. [Department of Structural Engineering, Norwegian University of science and Technology, Trondheim (Norway)

    2014-11-15

    The effect of magnesium and sulphate present in sea water on chloride binding in Portland cement paste was investigated. Ground well hydrated cement paste was exposed to MgCl{sub 2}, NaCl, NaCl + MgCl{sub 2}, MgSO{sub 4} + MgCl{sub 2} and artificial sea water solutions with a range of concentrations at 20 °C. Chloride binding isotherms are determined and pH of the solutions were measured. A selection of samples was examined by SEM-EDS to identify phase changes upon exposure. The experimental data were compared with calculations of a thermodynamic model. Chloride binding from sea water was similar to chloride binding for NaCl solutions. The magnesium content in the sea water lead to a slight decrease in pH, but this did not result in a notable increase in chloride binding. The sulphate present in sea water reduces both chloride binding in C–S–H and AFm phases, as the C–S–H incorporates more sulphates instead of chlorides, and part of the AFm phases converts to ettringite.

  20. Improvement of the Thermal, Photo and Mechanical Properties of Poly (Vinyl Chloride) in Presence of Poly (Glycidyl Methacrylate)

    OpenAIRE

    Abir S. Abdel-Naby

    2011-01-01

    Problem statement: Poly (vinyl chloride) suffers from poor heat stability. The thermal degradation of the polymer leads to the evolution of hydrogen chloride gas, extensive discoloration of the polymer and lowering of physical and mechanical properties. Approach: Binary blends of Poly (Vinyl Chloride) (PVC) and Poly (Glycidyl Methacrylate) (PGMA) have been prepared by solution blending aimed at the improvement of thermal and mechanical properties. Results and Conclusion:&#...