Methylene chloride exposure and carboxyhemoglobin levels in cabinetmakers

Science.gov (United States)

Banjoko, Sunny O.; Sridhar Mynapelli, K. C.; Ogunkola, Isiah O.; Masheyi, Olatunde O.

2007-01-01

Methylene chloride (MeCl2) is a clear colorless volatile sweet smelling lipophilic solvent used as a constituent of wood vanishes and paints. Human exposure is mainly due to inhalation and its biotransformation by the hepatic mixed function oxidases (MFO) leads to formation of carbon monoxide (CO). Simultaneous exposure to MeCl2 and increased ambient CO results in undesirably increased carboxyhemoglobin (COHb) formation, which predisposes to carboxyhemoglobinaemia with the central nervous system as the primary target organ of toxicity. In this study, ambient CO levels were determined using a CO personal monitor in different pasts of Ibadan Nigeria and work place microenvironment of 50 Cabinet makers (test group) and 50 volunteer (control) in non-furniture making occupations. Mann Whitney U and Kruskaal Wallis were the statistical methods of analysis used. Questionnaires were administered to both groups carboxyhaemoglobin levels were determined in venous blood drawn from individuals in the two groups by differential spectrophotometric method. Ambient CO levels in Ibadan were observed to be between 4 and 52 ppm with a mean of 20 ppm. Work environment CO levels were significantly higher in test subjects than controls at 5.2 ± 1.08 ppm and 2.08 ± 0.91 ppm respectively (P 0.05). It is therefore imperative to substitute MeCl2 for safer chemicals in wood vanish and paints and the use of protective gas masks and adequate ventilation should be mandatory whenever MeCl2 is used. PMID:21938216

Methylene blue adsorption from aqueous solution by dehydrated peanut hull

Energy Technology Data Exchange (ETDEWEB)

Ozer, Dursun [Department of Chemical Engineering, Firat University, 23279 Elazig (Turkey); Dursun, Guelbeyi [Department of Chemical Engineering, Firat University, 23279 Elazig (Turkey)]. E-mail: gdursun@firat.edu.tr; Ozer, Ahmet [Department of Chemical Engineering, Firat University, 23279 Elazig (Turkey)

2007-06-01

Dyes are colour organic compounds which can colorize the other substances. These substances usually presents in the effluent water of many industries, such as textiles, leather, paper, printing and cosmetics. To observe the potential feasibility of removing colour, peanut hull as an agricultural by-product was dehydrated with sulphuric acid (DPH) and used for adsorption of methylene blue (MB) from aqueous solution. The effects of various parameters such as initial methylene blue concentrations, temperatures and particle sizes were examined and optimal experimental conditions were determined. Adsorption data were well described by the Langmuir model, although they could be modelled by the Freundlich model as well. The adsorption process followed the pseudo-second order kinetic model. The mass transfer model as intraparticle diffusion was applied to the experimental data to examine the mechanisms of rate controlling step. It was found that at the higher initial MB concentration, intraparticle diffusion is becoming significant controlling step. The thermodynamic constants of the adsorption process were also evaluated by using the Langmuir constants related to the equilibrium of adsorption at different temperatures. The results in this study indicated that dehydrated peanut hull was a good adsorbent for removing methylene blue.

Potential adsorption of methylene blue from aqueous solution using green macroalgaePosidonia oceanica.

Science.gov (United States)

Allouche, F.-N.; Yassaa, N.

2018-03-01

The use of inexpensive biological materials, such as marine algae for removing dyes from contaminated industrial effluents appears as a potential alternative method. The aim of this study is to investigate the aptitude of marine macroalgae Posidonia Oceanica local biomass abundant on the coasts of Algeria for selective sorption of methylene blue (MB) from an aqueous solution in batch experiments at 20 °C. A maximum percentage removal of Posidonia oceanica occurs at pH 5. Equilibrium isotherm data were analyzed using the Langmuir and the Freundlich isotherms. The adsorption equilibrium of methylene blue was best describe by Langmuir model than the Freundlich model. The maximum sorption capacity was 357 mgg-1at pH 5. The sorption data were very well described by the pseudo-second-order model. Keywords: Posidonia oceanica, Methylene blue (MB), Biosorption, Isotherm Equilibrium, Kinetics; Modelling.

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)

Liu Min; Wang Lili; Zhu Lanying; Li Hui; Sun Dezhi; Di Youying; Li Linwei

2010-01-01

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 xy , h xxy , and h xyy ) according to the McMillan-Mayer theory. It has been found that the heterotactic enthalpic pairwise interaction coefficients h 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.

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.

Hydrolysis of ferric chloride in solution

International Nuclear Information System (INIS)

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 3 liquid + H 2 O → FeOCl solid + 2 HCl 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 solid + H 2 O → Fe 2 O 3 solid + 2 HCl 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

Crevice corrosion of alloy 22 in fluoride and chloride containing solutions

International Nuclear Information System (INIS)

Carranza, Ricardo M.; Rodriguez, Martin A.

2005-01-01

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 - ] [es

Multi-scale modelling of uranyl chloride solutions

Energy Technology Data Exchange (ETDEWEB)

Nguyen, Thanh-Nghi; Duvail, Magali, E-mail: magali.duvail@icsm.fr; Villard, Arnaud; Dufrêche, Jean-François, E-mail: jean-francois.dufreche@univ-montp2.fr [Institut de Chimie Séparative de Marcoule (ICSM), UMR 5257, CEA-CNRS-Université Montpellier 2-ENSCM, Site de Marcoule, Bâtiment 426, BP 17171, F-30207 Bagnols-sur-Cèze Cedex (France); Molina, John Jairo [Fukui Institute for Fundamental Chemistry, Kyoto University, Takano-Nishihiraki-cho 34-4, Sakyo-ku, Kyoto 606-8103 (Japan); Guilbaud, Philippe [CEA/DEN/DRCP/SMCS/LILA, Marcoule, F-30207 Bagnols-sur-Cèze Cedex (France)

2015-01-14

Classical molecular dynamics simulations with explicit polarization have been successfully used to determine the structural and thermodynamic properties of binary aqueous solutions of uranyl chloride (UO{sub 2}Cl{sub 2}). Concentrated aqueous solutions of uranyl chloride have been studied to determine the hydration properties and the ion-ion interactions. The bond distances and the coordination number of the hydrated uranyl are in good agreement with available experimental data. Two stable positions of chloride in the second hydration shell of uranyl have been identified. The UO{sub 2}{sup 2+}-Cl{sup −} association constants have also been calculated using a multi-scale approach. First, the ion-ion potential averaged over the solvent configurations at infinite dilution (McMillan-Mayer potential) was calculated to establish the dissociation/association processes of UO{sub 2}{sup 2+}-Cl{sup −} ion pairs in aqueous solution. Then, the association constant was calculated from this potential. The value we obtained for the association constant is in good agreement with the experimental result (K{sub UO{sub 2Cl{sup +}}} = 1.48 l mol{sup −1}), but the resulting activity coefficient appears to be too low at molar concentration.

NuLYTELY (PEG 3350, sodium chloride, sodium bicarbonate and potassium chloride for oral solution).

Science.gov (United States)

Swartz, M L

1992-02-01

NuLYTELY (PEG 3350, Sodium Chloride, Sodium Bicarbonate, and Potassium Chloride for Oral Solution), a product from Braintree Laboratories, Inc. is a modification of GoLYTELY (PEG 3350 and Electrolytes for Oral Solution) that has been found to have the same therapeutic advantages in terms of safety, efficacy, speed and patient acceptance. This product was developed to improve upon the taste of GoLYTELY. NuLYTELY represents an effective alternative for bowel cleansing prior to colonoscopy that may be more acceptable to some patients.

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

International Nuclear Information System (INIS)

Kochetkova, N.V.; Bayandina, Yu.E.; Toptygina, G.M.; Shepot'ko, A.O.

1988-01-01

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 In 2 S 3 solubility is higher than that of sodium chloride

Chloride stress corrosion cracking of Alloy 600 in boric acid solutions

International Nuclear Information System (INIS)

Berge, Ph.; Noel, D.; Gras, J.M.; Prieux, B.

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)

Removal of methylene blue from aqueous solution by adsorption onto pineapple leaf powder

International Nuclear Information System (INIS)

Weng, Chih-Huang; Lin, Yao-Tung; Tzeng, Tai-Wei

2009-01-01

The ability of an unconventional bio-adsorbent, pineapple leaf powder (PLP) for the adsorption of methylene blue (MB) from aqueous solution was studied. It was observed that intra-particle diffusion was involved in the adsorption process and that the kinetic data fitted well with a pseudo-second-order equation. Fitting parameters revealed that the rate of adsorption increased with decrease in dye concentration and decrease in ionic strength while the mixing speed did not have a significant effect on adsorption. The adsorption was favorable at higher pH and lower temperature, and the equilibrium data were well fitted by the Langmuir isotherm. The maximum adsorption capacity varied from 4.68 x 10 -4 to 9.28 x 10 -4 mol/g when pH increases from 3.5 to 9.5. Thermodynamic parameters suggest that the adsorption is a typical physical process, spontaneous, and exothermic in nature. The results revealed that this agricultural waste has potential to be used as an economical adsorbent for the removal of methylene blue from aqueous solution.

Removal of methylene blue from aqueous solution by adsorption onto pineapple leaf powder

Energy Technology Data Exchange (ETDEWEB)

Weng, Chih-Huang, E-mail: chweng@isu.edu.tw [Department of Civil and Ecological Engineering, I-Shou University, Da-Hsu Township, Kaohsiung 84008, Taiwan (China); Lin, Yao-Tung; Tzeng, Tai-Wei [Department of Soil and Environmental Sciences, National Chung Hsing University, TaiChung 40227, Taiwan (China)

2009-10-15

The ability of an unconventional bio-adsorbent, pineapple leaf powder (PLP) for the adsorption of methylene blue (MB) from aqueous solution was studied. It was observed that intra-particle diffusion was involved in the adsorption process and that the kinetic data fitted well with a pseudo-second-order equation. Fitting parameters revealed that the rate of adsorption increased with decrease in dye concentration and decrease in ionic strength while the mixing speed did not have a significant effect on adsorption. The adsorption was favorable at higher pH and lower temperature, and the equilibrium data were well fitted by the Langmuir isotherm. The maximum adsorption capacity varied from 4.68 x 10{sup -4} to 9.28 x 10{sup -4} mol/g when pH increases from 3.5 to 9.5. Thermodynamic parameters suggest that the adsorption is a typical physical process, spontaneous, and exothermic in nature. The results revealed that this agricultural waste has potential to be used as an economical adsorbent for the removal of methylene blue from aqueous solution.

Cation exchange process for recovery of plutonium from laboratory solutions containing chloride

International Nuclear Information System (INIS)

Gray, L.W.

1978-10-01

A cation exchange technique was developed for the separation of plutonium from laboratory solutions containing either Pu(III) or Pu(III)--Pu(IV) mixtures in acidic solutions containing chloride ions. The procedure consists of adjusting the acid concentration to less than one molar and adjusting the valence of the plutonium ion to the (III) state, if necessary. The adjusted solution is fed to a cation exchange column and washed with distilled water to remove residual chlorides from the column. Plutonium is then eluted from the column with 5M nitric acid containing 0.34M sulfamic acid. This procedure was used to separate plutonium from 1.2M chloride solution on a production-scale column. Typical plutonium recovery was 99.97%, while greater than 96% of the original chloride was rejected

Radioiodinated methylene blue for melanoma targeting: Chemical characterisation and tumour selectivity of labelled components

International Nuclear Information System (INIS)

Blower, Philip J.; Clark, Katherine; Link, Eva M.

1997-01-01

Radioiodinated methylene blue contains a mixture of components showing selective uptake in human pigmented melanoma, and it has potential for imaging and therapy. Nuclear magnetic resonance and mass spectroscopic studies show that the majority of the radioactivity (85%) is in the form of monoiodinated methylene blue, 4-iodo-3-methylamino-7-dimethylaminophenaza thionium chloride. The amino group ortho-to iodine has become demethylated to a mono-methylamino group. The remainder (15%) of the mixture is the doubly labelled 4,5-diiodo-3,7-bis(methylamino) phenazathionium chloride. The separated components show similar tumour selectivity in athymic mice bearing human pigmented melanomas

Adsorption behaviors of trivalent actinides and lanthanides on pyridine resin in lithium chloride aqueous solution

International Nuclear Information System (INIS)

Tatsuya Suzuki

2013-01-01

The adsorption behaviors of trivalent actinides and lanthanides on pyridine resin in lithium chloride aqueous solution were investigated. The adsorbed amounts of lanthanides and the degree of mutual separation of lanthanides increased with an increase in the concentration of lithium chloride in aqueous solution. The group separation of the trivalent actinides and lanthanides was observed. This separation phenomenon is similar in a hydrochloric acid solution. However, the adsorption behavior of lanthanides in lithium chloride is different from their behavior in a hydrochloric acid solution. This fact shows that the adsorption mechanisms of lanthanides in a lithium chloride aqueous solution and in a hydrochloric acid solution are different; the adsorption mechanisms are attributed to the ion exchange in a hydrochloric acid solution, and to the complex formation with pyridine group in a lithium chloride solution. (author)

Solid-phase extraction of cobalt(II) from lithium chloride solutions using a poly(vinyl chloride)-based polymer inclusion membrane with Aliquat 336 as the carrier.

Science.gov (United States)

Kagaya, Shigehiro; Cattrall, Robert W; Kolev, Spas D

2011-01-01

The extraction of cobalt(II) from solutions containing various concentrations of lithium chloride, hydrochloric acid, and mixtures of lithium chloride plus hydrochloric acid is reported using a poly(vinyl chloride) (PVC)-based polymer inclusion membrane (PIM) containing 40% (w/w) Aliquat 336 as a carrier. The extraction from lithium chloride solutions and mixtures with hydrochloric acid is shown to be more effective than extraction from hydrochloric acid solutions alone. The solution concentrations giving the highest amounts of extraction are 7 mol L(-1) for lithium chloride and 8 mol L(-1) lithium chloride plus 1 mol L(-1) hydrochloric acid for mixed solutions. Cobalt(II) is easily stripped from the membrane using deionized water. The cobalt(II) species extracted into the membrane are CoCl(4)(2-) for lithium chloride solutions and HCoCl(4)(-) for mixed solutions; these form ion-pairs with Aliquat 336. It is also shown that both lithium chloride and hydrochloric acid are extracted by the PIM and suppress the extraction of cobalt(II) by forming ion-pairs in the membrane (i.e. R(3)MeN(+)·HCl(2)(-) for hydrochloric acid and R(3)MeN(+)·LiCl(2)(-) for lithium chloride). 2011 © The Japan Society for Analytical Chemistry

Thermodynamic properties of potassium chloride aqueous solutions

Science.gov (United States)

Zezin, Denis; Driesner, Thomas

2017-04-01

Potassium chloride is a ubiquitous salt in natural fluids, being the second most abundant dissolved salt in many geological aqueous solutions after sodium chloride. It is a simple solute and strong electrolyte easily dissociating in water, however the thermodynamic properties of KCl aqueous solutions were never correlated with sufficient accuracy for a wide range of physicochemical conditions. In this communication we propose a set of parameters for a Pitzer-type model which allows calculation of all necessary thermodynamic properties of KCl solution, namely excess Gibbs free energy and derived activity coefficient, apparent molar enthalpy, heat capacity and volume, as well as osmotic coefficient and activity of water in solutions. The system KCl-water is one of the best studied aqueous systems containing electrolytes. Although extensive experimental data were collected for thermodynamic properties of these solutions over the years, the accurate volumetric data became available only recently, thus making possible a complete thermodynamic formulation including a pressure dependence of excess Gibbs free energy and derived properties of the KCl-water liquids. Our proposed model is intended for calculation of major thermodynamic properties of KCl aqueous solutions at temperatures ranging from freezing point of a solution to 623 K, pressures ranging from saturated water vapor up to 150 MPa, and concentrations up to the salt saturation. This parameterized model will be further implemented in geochemical software packages and can facilitate the calculation of aqueous equilibrium for reactive transport codes.

Structure of methylene chloride addition product to zirconium tetrachloride complex with 1-tert.-butyl-2,4,4-trimethyl-2-thio-trimethylsilyl-1,3,2,4-diazaphosphasilatedine

International Nuclear Information System (INIS)

Brusilovets, A.I.; Rusanov, Eh.B.; Chernega, A.N.

1995-01-01

Complex of zirconium tetrachloride with 1-tert.-butyl-2,4,4-trimethyl--2-thio-3-trimethyl-silyl-1,3,2,4-diazaphosphasilatedine interacts with methylene chloride with formation of bis[3-tert.-butyl-2,4,4-trimethyl-1--trimethylsilyl-2-chloremethylthio-1,3,2,4-diazaphosphasilatedinium] decachlorodizirconate. Specific features of crystal and molecular structure of the compound prepared have been studied by X-ray diffraction method. 21 refs.; 2 figs.; 2 tabs

Adsorption of methylene blue onto treated activated carbon

International Nuclear Information System (INIS)

Yamin Yasin; Mohd Zobir Hussein; Faujan Ahmad

2007-01-01

The potential feasibility of treated and untreated activated carbon for removal of methylene blue from aqueous solution was investigated. The effects of various experimental parameters such as contact time, solution pH and adsorbent dosage were investigated. The extent of methylene blue removal increased with the increased in contact time, solution pH and amount of adsorbent used. Adsorption data was better fitted to the Langmuir isotherm. The results in this study indicated that the treated activated carbon was an attractive candidate for removing organic dye of methylene blue which shows great reduction of colour while reducing the time contact to achieve equilibrium. (author)

Citrus pectin derived porous carbons as a superior adsorbent toward removal of methylene blue

International Nuclear Information System (INIS)

Zhang, Wenlin; Zhang, Lian Ying; Zhao, Xi Juan; Zhou, Zhiqin

2016-01-01

An adsorbent, citrus pectin derived porous carbons with ultra-high adsorption capacity, rapid adsorption rate and good reusability toward removal of methylene blue, was synthesized by a facile zinc chloride activation approach in this study. The materials hold a great potential for treatment of dye wastewater. - Graphical abstract: Citrus pectin derived porous carbons with ultra-high adsorption capacity, rapid adsorption rate and good reusability toward methylene blue removal. - Highlights: • Citrus pectin derived porous carbons (CPPCs) were synthesized a facile zinc chloride activation approach. • CPPCs had abundant macro/meso/micropores for trapping MB molecules. • CPPCs exhibited ultrahigh adsorption capacity, rapid adsorption rate and good reusability toward removal of MB.

Citrus pectin derived porous carbons as a superior adsorbent toward removal of methylene blue

Energy Technology Data Exchange (ETDEWEB)

Zhang, Wenlin [College of Horticulture and landscape Architecture, Southwest University, Chongqing 400716 (China); Zhang, Lian Ying [Institute for Clean Energy & Advanced Materials, Southwest University, Chongqing 400715 (China); Zhao, Xi Juan [College of Horticulture and landscape Architecture, Southwest University, Chongqing 400716 (China); Key Laboratory of Horticulture Science for Southern Mountainous Regions, Ministry of Education, Chongqing 400715 (China); Zhou, Zhiqin, E-mail: zhouzhiqin@swu.edu.cn [College of Horticulture and landscape Architecture, Southwest University, Chongqing 400716 (China); Key Laboratory of Horticulture Science for Southern Mountainous Regions, Ministry of Education, Chongqing 400715 (China)

2016-11-15

An adsorbent, citrus pectin derived porous carbons with ultra-high adsorption capacity, rapid adsorption rate and good reusability toward removal of methylene blue, was synthesized by a facile zinc chloride activation approach in this study. The materials hold a great potential for treatment of dye wastewater. - Graphical abstract: Citrus pectin derived porous carbons with ultra-high adsorption capacity, rapid adsorption rate and good reusability toward methylene blue removal. - Highlights: • Citrus pectin derived porous carbons (CPPCs) were synthesized a facile zinc chloride activation approach. • CPPCs had abundant macro/meso/micropores for trapping MB molecules. • CPPCs exhibited ultrahigh adsorption capacity, rapid adsorption rate and good reusability toward removal of MB.

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

International Nuclear Information System (INIS)

Lakoza, G.N.; Grigor'eva, O.L.; Mart'yanova, B.M.; Vorob'eva, E.N.; Kuznetsova, R.M.

1976-01-01

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.)

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.

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

Institute of Scientific and Technical Information of China (English)

WANG Zixiao; YU Lei; LIU Zhiyong; SONG Ning

2015-01-01

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

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

International Nuclear Information System (INIS)

Haftirman; Maruhum Tua Lubis

2009-01-01

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

Localized corrosion of molybdenum-bearing nickel alloys in chloride solutions

International Nuclear Information System (INIS)

Postlethwaite, J.; Scoular, R.J.; Dobbin, M.H.

1988-01-01

Electrochemical and immersion tests have been applied to a study of the localized corrosion resistance of two molybdenum-bearing nickel alloys. Alloys C-276 and 6y25, in neutral chloride solutions in the temperature range of 25 to 200 C as part of the container materials evaluation screening tests for the Canadian Nuclear Fuel Waste Management Program. Cyclic polarization studies show that the passivation breakdown potentials move rapidly to more active values with increasing temperatures, indicating a reduced resistance to localized corrosion. The results of immersion tests show that both alloys do suffer crevice corrosion in neutral aerated sodium chloride solutions at elevated temperatures, but that in both cases there is a limiting temperature > 100C, below which, the alloys are not attacked, regardless of the chloride concentration

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.

X-ray diffraction phase analysis of crystalline copper corrosion products after treatment in different chloride solutions

International Nuclear Information System (INIS)

Chmielova, M.; Seidlerova, J.; Weiss, Z.

2003-01-01

The corrosion products Cu 2 (OH) 3 Cl, Cu 2 O, and CuCl 2 were identified on the surface of copper plates after their four days treating in three different sodium chloride, sodium/magnesium, and sodium/calcium chloride solutions using X-ray diffraction powder analysis. However, the quantitative proportions of individual corrosion products differ and depend on the type of chloride solution used. Treating of copper plates only in the sodium chloride solution produced the mixture of corrosion products where Cu 2 O is prevailing over the Cu 2 (OH) 3 Cl and CuCl 2 was not identified. The sample developed after treating of the cooper surface in the sodium/magnesium chloride solution contains Cu 2 (OH) 3 Cl and CuCl 2 prevailing over the Cu 2 O, while the sample developed after treatment of copper in sodium/calcium chloride solution contains Cu 2 (OH) 3 Cl prevailing over CuCl 2 and Cu 2 O was not identified

Separation of beryllium and mercury from lithium chloride solution by gaseous extraction

International Nuclear Information System (INIS)

Sevast'yanov, A.I.; Chepovol, V.I.

1989-01-01

The possibility is shown of extracting beryllium and mercury by acetylacetone (HAA) from lithium chloride solution by passing argon through the solution and the optimum conditions have been determined. The dependence of the degree of extraction and the distribution coefficients on various parameters of the liquid phase are presented, viz. the initial pH value, the lithium chloride concentration, and the initial HAA content

Pitting corrosion of Inconel 600 in chloride and sulfate solutions at low temperature

International Nuclear Information System (INIS)

Chang Mingyu; Yu Geping

1993-01-01

Pitting corrosion of Inconel 600 was examined in chloride and sulfate solutions through usage of potentiodynamic polarization techniques. The effects of chloride and sulfate concentration were investigated in the range of 0.0001 to 0.1 M. Increasing chloride concentrations resulted in active shifts of the pit nucleation potential. Immunity to pitting corrosion was evident at a chloride level below 0.005 M. Increasing sulfate concentrations resulted in improved pitting resistance of Inconel 600 in chloride solutions. Detrimental effects associated with pitting were evident with low-level sulfate being added to dilute chloride media. The density of pits increased with increasing chloride concentrations or temperature between room temperature and 70 C. Systematic trends for the depth of pits were not evident. The observations of pitting corrosion in open immersion were consistent with those in polarization methods. Corrosion products contained in the pits were enriched in nickel, chromium and iron with a small amount of titanium and silicon. The enrichment of chlorine or sulfur was still, however, not found. (orig.)

Rheological properties of poly-vinyl-chloride solutions in varioussolvents

International Nuclear Information System (INIS)

Kurbanaliev, M.K.; Narzullaev, B.N.; Dustov, I.K.; Marupov, R.M.

1976-01-01

The present article is the result of studying of curves process ofpoly-vinyl-chloride solutions in wide interval of tension and velocities ofshear in thermodynamically good and bad solvents at various temperatures

Inactivation of Biological Agents Using Neutral Oxone-Chloride Solutions

National Research Council Canada - National Science Library

Delcomyn, Carrie A; Bushway, Karen E; Henley, Michael V

2006-01-01

... to contaminated equipment or terrain. A neutral, bicarbonate-buffered aqueous solution of Oxone and sodium chloride that rapidly generates hypochlorite and hypochlorous acid in situ was evaluated as a new alternative to bleach...

Use of Hypertonic Sodium Chloride Solution at Surgery under Extracorporeal Circulation

Directory of Open Access Journals (Sweden)

V. V. Lomivorotov

2012-01-01

Full Text Available The paper analyzes the data available in the references on different aspects of using hypertonic sodium chloride solution during surgery under extracorporeal circulation in cardiosurgical care. The hypertonic solution is shown to lower positive fluid balance in the perioperative period, to increase cardiac output with simultaneously decreased vascular resistance, to improve lung oxygenating function, and to normalize tissue blood circulation and neurological status in patients exposed to artificial perfusion. There is evidence for its effect on the immune system and capillary endothelium. It is suggested that it is necessary to study the effect of the hypertonic solution on the incidence of complications and death rates during surgery under extracorporeal circulation and it is proposed to use the solution under long-term extracorporeal circulation. Key words: hypertonic saline, sodium chloride, extracorporeal circulation.

Uniform Cu2Cl(OH)3 hierarchical microspheres: A novel adsorbent for methylene blue adsorptive removal from aqueous solution

International Nuclear Information System (INIS)

Wei, Wei; Gao, Pin; Xie, Jimin; Zong, Sekai; Cui, Henglv; Yue, Xuejie

2013-01-01

Using the solution phase method without any surfactants or templates, the hierarchical of Cu 2 Cl(OH) 3 microspheres were synthesized by freeze drying. The size and surface area of the microspheres are ca. 1–2 µm and 76.61 m 2 g −1 , respectively. A possible formation mechanism is presented based on the experimental results. Methylene blue was chosen to investigate the adsorption capacity of the as-prepared adsorbent. The effects of various experimental parameters, such as pH, initial dye concentration, and contact time were investigated. The results showed that the dye removal increased with the increasing in the initial concentration of the dye and also increased in the amount of microspheres used and initial pH. Adsorption data fitted well with the Freundlich adsorption isotherm. The thermodynamic analysis presented the exothermic, spontaneous and more ordered arrangement process. The microspheres could be employed effective for removal of dyes from aqueous solution. - Graphical abstract: The single-crystalline hierarchical Cu 2 Cl(OH) 3 spheres can be prepared for the first time by using a template-free process through freeze-drying. Meanwhile, the hierarchical spheres exhibited high adsorption capacity to methylene blue. Display Omitted - Highlights: • Cu 2 Cl(OH) 3 microspheres were successfully synthesized through a freeze drying process. • A possible formation mechanism of hierarchical microspheres was presented. • The Cu 2 Cl(OH) 3 microspheres have high methylene blue adsorption capacity. • Methylene blue adsorption is a spontaneous and exothermic process. • The adsorption mechanism of microspheres onto dye was proposed in detail

Effect of metal chloride solutions on coloration and biaxial flexural strength of yttria-stabilized zirconia

Science.gov (United States)

Oh, Gye-Jeong; Lee, Kwangmin; Lee, Doh-Jae; Lim, Hyun-Pil; Yun, Kwi-Dug; Ban, Jae-Sam; Lee, Kyung-Ku; Fisher, John G.; Park, Sang-Won

2012-10-01

The effect of three kinds of transition metal dopants on the color and biaxial flexural strength of zirconia ceramics for dental applications was evaluated. Presintered zirconia discs were colored through immersion in aqueous chromium, molybdenum and vanadium chloride solutions and then sintered at 1450 °C. The color of the doped specimens was measured using a digital spectrophotometer. For biaxial flexural strength measurements, specimens infiltrated with 0.3 wt% of each aqueous chloride solution were used. Uncolored discs were used as a control. Zirconia specimens infiltrated with chromium, molybdenum and vanadium chloride solutions were dark brown, light yellow and dark yellow, respectively. CIE L*, a*, and b* values of all the chromium-doped specimens and the specimens infiltrated with 0.1 wt% molybdenum chloride solution were in the range of values for natural teeth. The biaxial flexural strengths of the three kinds of metal chloride groups were similar to the uncolored group. These results suggest that chromium and molybdenum dopants can be used as colorants to fabricate tooth colored zirconia ceramic restorations.

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

International Nuclear Information System (INIS)

Lafont, C.J.; Alvarez, M.G.

1993-01-01

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 NaHCO 3 , at 100 degrees C, 200 degrees C, 280 degrees C; 0.06M NaH 2 PO 4 + 0.04M Na 2 HPO 4 , 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 NaHCO 3 and 0.06M NaH 2 PO 4 + 0.04M Na 2 HPO 4 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

Potential Biosorbent Derived from Calligonum polygonoides for Removal of Methylene Blue Dye from Aqueous Solution

Science.gov (United States)

Nasrullah, Asma; Khan, Hizbullah; Khan, Amir Sada; Man, Zakaria; Muhammad, Nawshad; Khan, Muhammad Irfan; Abd El-Salam, Naser M.

2015-01-01

The ash of C. polygonoides (locally called balanza) was collected from Lakki Marwat, Khyber Pakhtunkhwa, Pakistan, and was utilized as biosorbent for methylene blue (MB) removal from aqueous solution. The ash was used as biosorbent without any physical or chemical treatment. The biosorbent was characterized by using various techniques such as Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The particle size and surface area were measured using particle size analyzer and Brunauer-Emmett-Teller equation (BET), respectively. The SEM and BET results expressed that the adsorbent has porous nature. Effects of various conditions such as initial concentration of methylene blue (MB), initial pH, contact time, dosage of biosorbent, and stirring rate were also investigated for the adsorption process. The rate of the adsorption of MB on biomass sample was fast, and equilibrium has been achieved within 1 hour. The kinetics of MB adsorption on biosorbent was studied by pseudo-first- and pseudo-second-order kinetic models and the pseudo-second-order has better mathematical fit with correlation coefficient value (R 2) of 0.999. The study revealed that C. polygonoides ash proved to be an effective, alternative, inexpensive, and environmentally benign biosorbent for MB removal from aqueous solution. PMID:25705714

Corrosion behavior of sodium-exposed stainless steels in chloride-containing aqueous solutions

International Nuclear Information System (INIS)

Wu, P.C.S.; Grundy, B.R.; Miller, R.L.

1979-01-01

The corrosion behavior of sodium-exposed stainless steels in chloride-containing aqueous solutions was investigated. Results showed that sodium-corroded Type 316 stainless steel (prototypic Liquid Metal Fast Breeder Reactor (LMFBR) fuel cladding) maintains its integrity after five months exposure in these solutions at 82 0 C and with chloride content up to 500 ppM. In contrast, sensitized and sodium mass transfer deposit-containing Type 304 stainless steel failed in the high chloride solution (500 ppM) within ten days at the same temperature. The failure was initiated by pitting and subsequently accelerated by intergranular attack. The results also show that high pH tends to reduce the susceptibility to failure while procedures commonly used for sodium removal have no significant effect on the water corrosion behavior of the test material. Based on the current results, it is concluded that water shortage is feasible for spent fuels in a LMFBR reprocessing plant

33 Effects of Sodium Chloride Solutions on Compressive Strength ...

African Journals Online (AJOL)

Arc. Usman A. Jalam

strength increase at 3 and 7 days over control cubes; at 28 days concrete cubes containing 5%. RHA cured in NaCl solutions recorded higher strength loss compared to control cubes. Keywords: ... chloride in mixing water reported it to cause.

Incoloy 800 anodic behavior in sulfate and chloride solutions at high temperature

International Nuclear Information System (INIS)

Lafont, C.; Alvarez, M.G.

1992-01-01

The anodic behavior and pitting corrosion resistance of Incoloy 800 in concentrated aqueous chloride and sulphate solutions has been studied by means of electrochemical techniques. The effect of different environmental variables, such as temperature (in the 100 0 C to 280 0 C range) and sulphate ion concentration (0.02 M to 2 M), was evaluated. In another set of experiments, the influence of sulphate ions additions on the pitting resistance and pitting morphology of Incoloy 800 in chloride solutions at high temperature was also examined. (author)

IRIS Toxicological Review of Dichloromethane (Methylene ...

Science.gov (United States)

EPA has finalized the Toxicological Review of Dichloromethane (Methylene Chloride): In support of the Integrated Risk Information System (IRIS). Now final, this assessment may be used by EPA’s program and regional offices to inform decisions to protect human health. This document presents background information and justification for the Intergrated Risk Information System (IRIS) Summary of the hazard and dose-response assessment of dichloromethane. IRIS Summaries may include oral reference dose (RfD) and inhalation reference concentration (RfC) values for chronic and other exposure durations, and a carcinogencity assessment. Internet/NCEA web site

Process for crosslinking methylene-containing aromatic polymers with ionizing radiation

Science.gov (United States)

Bell, Vernon L. (Inventor); Havens, Stephen J. (Inventor)

1990-01-01

A process for crosslinking aromatic polymers containing radiation-sensitive methylene groups (-CH2-) by exposing the polymers to ionizing radiation thereby causing crosslinking of the polymers through the methylene groups is described. Crosslinked polymers are resistant to most organic solvents such as acetone, alcohols, hydrocarbons, methylene, chloride, chloroform, and other halogenated hydrocarbons, to common fuels and to hydraulic fluids in contrast to readily soluble uncrosslinked polymers. In addition, the degree of crosslinking of the polymers depends upon the percentage of the connecting groups which are methylene which ranges from 5 to 50 pct and preferably from 25 to 50 pct of the connecting groups, and is also controlled by the level of irradiation which ranges from 25 to 1000 Mrads and preferably from 25 to 250 Mrads. The temperature of the reaction conditions ranges from 25 to 200 C and preferably at or slightly above the glass transition temperature of the polymer. The crosslinked polymers are generally more resistant to degradation at elevated temperatures such as greater than 150 C, have a reduced tendency to creep under load, and show no significant embrittlement of parts fabricated from the polymers.

Critical pitting temperature for Type 254 SMO stainless steel in chloride solutions

International Nuclear Information System (INIS)

Abd El Meguid, E.A.; Abd El Latif, A.A.

2007-01-01

The variation with time of the open circuit potential of high molybdenum containing stainless steel (Type 254 SMO) was measured in 4% sodium chloride solution in the temperatures range 30-100 deg. C. The plot of steady state potentials as function of temperature showed an inflection at 50 deg. C, attributed to the decrease of oxygen solubility in test solution above 50 deg. C. Potentiodynamic cycling anodic polarization technique was used to determine the critical pitting potential (E pit ) and the critical protection potential (E prot ) of the steel in 4-30% NaCl solutions at temperatures between 30 and 100 deg. C. By plotting the two values versus solution temperature, the corresponding critical pitting (CPT) and the critical protection (CPrT) temperatures were determined. Both parameters decreased with increasing chloride content. Above the CPT, E pit and E prot decreased linearly with log[Cl - ]. The addition of bromide ions to the solution shifted both E pit and E prot towards positive values. In 4% NaCl, E pit increased linearly with pH in the range 1-10. The combined effect of chloride ion concentration and pH on the morphology of the pits was examined by scanning electron microscopy (SEM) following potentiodynamic cycling anodic polarization

Determination of low chloride values in Rocky Flats scrub alloy solutions and other complex matrices

International Nuclear Information System (INIS)

Holcomb, H.P.

1985-01-01

A turbidimetric method, using silver chloride, has been developed to determine low ppM quantities of chloride in Rocky Flats scrub alloy (RFSA) dissolver solutions. This analytical technique has also been applied to other complex matrices such as process 50% caustic and neutralized Purex low heat liquid waste concentrate. A controlled-pH precipitation with NaOH, during which chloride remains in solution, is used to pretreat samples to minimize salt effects from acids, bases, and/or hydrolyzable ions. Control of pH with bromocresol purple indicator also provides a more consistent pH for silver chloride formation, aiding in turbidity reproducibility. Disodium ethylenediaminetetraacetic acid is employed to negate covalent bonding by Hg(II) with chloride. The average standard deviation was +-17% for turbidity reproducibility in simulated sample aliquots containing a total of 10 to 100 μg chloride. For actual RFSA samples, the relative standard deviation ranged from +-14% to +-26%, depending on initial chloride values. 8 refs., 1 fig

Methylene blue doped polymers: efficient media for optical recording

Science.gov (United States)

Ushamani, M.; Sreekumar, K.; Sudha Kartha, C.; Joseph, R.

2004-05-01

Polymer materials find application in optical storage technology, namely in the development of high information density and fast access type memories. A new polymer blend of methylene blue sensitized polyvinyl alcohol (PVA) and polyacrylic acid (PAA) in methanol is prepared and characterized and its comparison with methylene blue sensitized PVA in methanol and complexed methylene blue sensitized polyvinyl chloride (CMBPVC) is presented. The optical absorption spectra of the thin films of these polymers showed a strong and broad absorption region at 670-650 nm, matching the wavelength of the laser used. A very slow recovery of the dye on irradiation was observed when a 7:3 blend of polyvinyl alcohol/polyacrylic acid at a pH of 3.8 and a sensitizer concentration of 4.67 · 10-5 g/ml were used. A diffraction efficiency of up to 20% was observed for the MBPVA/alcohol system and an energetic sensitivity of 2000 mJ/cm2 was obtained in the photosensitive films with a spatial frequency of 588 lines/mm.

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.

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.

Spatial structure of transition metal complexes in solution determined by EXAFS spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Erenburg, S.B. E-mail: simon@che.nsk.su; Bausk, N.V.; Zemskova, S.M.; Mazalov, L.N

2000-06-21

CdK EXAFS, ZnK and CuK EXAFS and XANES spectra were measured for solutions of cadmium, zinc and copper dialkyldithiocarbamates in organic solvents with varying donating abilities: tributylphosphine, methylene chloride, benzene, dibutylsulfide, pyridine, dimethylsulfoxide and for some model compounds. The parameters of the local surroundings of the Cd, Zn and Cu atoms for complex forms in solutions were determined using EXAFS spectroscopy. Spatial structure models of the complex forms in a metal chelate - nonaqueous solvent system are suggested.

Spatial structure of transition metal complexes in solution determined by EXAFS spectroscopy

International Nuclear Information System (INIS)

Erenburg, S.B.; Bausk, N.V.; Zemskova, S.M.; Mazalov, L.N.

2000-01-01

CdK EXAFS, ZnK and CuK EXAFS and XANES spectra were measured for solutions of cadmium, zinc and copper dialkyldithiocarbamates in organic solvents with varying donating abilities: tributylphosphine, methylene chloride, benzene, dibutylsulfide, pyridine, dimethylsulfoxide and for some model compounds. The parameters of the local surroundings of the Cd, Zn and Cu atoms for complex forms in solutions were determined using EXAFS spectroscopy. Spatial structure models of the complex forms in a metal chelate - nonaqueous solvent system are suggested

Batch Adsorption Study of Methylene Blue in Aqueous Solution ...

African Journals Online (AJOL)

PROF HORSFALL

of methylene blue (azo dye) from the synthetic industrial wastewater was investigated in a batch system. Rice husk and coconut shell were ... the textiles, rubber, paper, plastics, cosmetic, and .... wastewater by. Fenton's oxidation: Kinetic study.

The uptake of silver(I from chloride solutions by amine extractants

Directory of Open Access Journals (Sweden)

Wejman Katarzyna

2017-01-01

Full Text Available The amine extractants, bis(2-ethylhexylamine, N,N-dimethylethanolamine, and trioctylamine were used to recover silver(I ions from chloride solutions. The effect of the pH, contact time, extractant concentration and reextraction were studied. It was found that extraction of silver(I depended on the pH, extractant concentration and strongly on the contact time. Reextraction of Ag(I ions from the loaded organic phase showed that the metal can be removed in over 50% for the three extractant using sodium hydroxide. The recovery of silver from the chloride leaching solutions were above 85% for bis(2-ethylhexylamine, above 58% for N,N-dimethylethanolamine, and above 70% for trioctylamine.

Corrosion of Dental Au-Ag-Cu-Pd Alloys in 0.9 % Sodium Chloride Solution

International Nuclear Information System (INIS)

Chiba, Atsushi; Kusayanagi, Yukiharu

2005-01-01

Two Au-Ag-Cu-Pd dental casting alloys (Au:12% and 20%) used. The test solutions used 0.9 % NaCl solution (isotonic sodium chloride solution), 0.9 % NaCl solution containing 1 % lactic acid, and 0.9 % NaCl solution containing 1 % lactic acid and 0.1 mol dm -3 Na 2 S. The surface of two samples in three sample solutions was not natural discoloration during one year. The alloy containing 12 % gold was easily alloyed and the composition was uniform comparing with the alloy containing 20 % gold. The rest potentials have not a little effect after three months. The kinds of metals could not definitely from the oxidation and reduction waves of metal on the cyclic voltammograms. The dissolutions of gold and palladium were 12 % Au sample in the 0.9 % NaCl solution containing 1 % lactic acid and 0.1 mol dm -3 Na 2 S. The pH of solution had an affect on dissolution of copper, and sulfur ion had an affect on dissolution of silver. The copper dissolved amount from 20 % gold sample was about 26 times comparing with that of 12 % gold sample in the 0.9 % solution containing 1 % lactic acid. Corrosion products were silver chloride and copper chloride in NaCl solution, and silver sulfide and copper sulfide in NaCl solution containing Na 2 S

Benzotriazole as an inhibitor of brass corrosion in chloride solution

International Nuclear Information System (INIS)

Kosec, Tadeja; Milosev, Ingrid; Pihlar, Boris

2007-01-01

The current research explores the formation of protective layers on copper, zinc and copper-zinc (Cu-10Zn and Cu-40Zn) alloys in chloride solution containing benzotriazole (BTAH), by use of electrochemical techniques, atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). Electrochemical reactions and surface products formed at the open circuit potential and as a function of the potential range are discussed. The addition of benzotriazole to aerated, near neutral 0.5 M NaCl solution affects the dissolution of copper, zinc, Cu-10Zn and Cu-40Zn alloys. The research also compares the inhibition efficiency and Gibbs adsorption energies of the investigated process. Benzotriazole, generally known as an inhibitor of copper corrosion is also shown to be an efficient inhibitor for copper-zinc alloys and zinc metal. The surface layer formed on alloys in BTAH-inhibited solution comprised both oxide and polymer components, namely Cu 2 O and ZnO oxides, and Cu(I)-BTA and Zn(II)-BTA polymers. The formation of this mixed copper-zinc oxide polymer surface film provides an effective barrier against corrosion of both metal components in chloride solution

Sorption and permeation of solutions of chloride salts, water and methanol in a Nafion membrane

International Nuclear Information System (INIS)

Villaluenga, J.P.G.; Barragan, V.M.; Seoane, B.; Ruiz-Bauza, C.

2006-01-01

The sorption of water-methanol mixtures containing a dissolved chloride salt in a Nafion 117 membrane, and their transport through the membrane under the driving force of a pressure gradient, have been studied. Both type of experiments was performed by using five different salts: lithium chloride, sodium chloride, cesium chloride, magnesium chloride and calcium chloride. It was observed that both the permeation flow through the membrane and the membrane swelling increase significantly with the methanol content of the solutions. These facts are attributed to the increase in wet membrane porosity, which brings about the increase of the mobility of solvents in the membrane, besides the increase of the mobility of the polymer pendant chains. In contrast, the influence of the type of electrolyte on the membrane porosity and permeability is not very important, with the exception of the CsCl solutions, which is probably due to the small hydration ability of the Cs + ion

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

International Nuclear Information System (INIS)

Fahey, J.; Holmes, D.; Yau, T.L.

1995-01-01

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

An electrochemical investigation of the corrosion behavior of aluminum alloys in chloride containing solutions

International Nuclear Information System (INIS)

Campos Filho, Jorge Eustaquio de

2005-01-01

Aluminum alloys have been used as cladding materials for nuclear fuel in research reactors due to its corrosion resistance. Aluminum owes its good corrosion resistance to a protective barrier oxide film formed and strongly bonded to its surface. In pool type TRIGA IPR-R1 reactor, located at Centro de Desenvolvimento da Tecnologia Nuclear in Belo Horizonte, previous immersion coupon tests revealed that aluminum alloys suffer from pitting corrosion, in spite of high quality of water control. Corrosion attack is initiated by breaking the protective oxide film on aluminum alloy surface. Chloride ions can break this oxide film and stimulate metal dissolution. In this study the aluminum alloys 1050, 5052 and 6061 were used to evaluate their corrosion behavior in chloride containing solutions. The electrochemical techniques used were potentiodynamic anodic polarization and cyclic polarization. Results showed that aluminum alloys 5052 and 6061 present similar corrosion resistance in low chloride solutions (0,1 ppm NaCl) and in reactor water but both alloys are less resistant in high chloride solution (1 ppm NaCl). Aluminum alloy 1050 presented similar behavior in the three electrolytes used, regarding to pitting corrosion, indicating that the concentration of the chloride ions was not the only variable to influence its corrosion susceptibility. (author)

Hydration patterns and salting effects in sodium chloride solution.

Science.gov (United States)

Li, Weifeng; Mu, Yuguang

2011-10-07

The salting effects of 2M sodium chloride electrolyte are studied based on a series of model solutes with properties ranging from hydrophobic to hydrophilic. Generally, hydrophobic solutes will be salted out and hydrophilic solutes will be salted in by NaCl solution. The solvation free energy changes are highly correlated with Kirkwood-Buff integrals. The underlying mechanism resorts to the preferential binding of ions and water to solutes. Our results demonstrate that the salting effect not only depends on the salt's position in Hofmeister series, but also on the solutes' specifics. Taking the hydration free energies of solutes and ions as independent variables, a schematic diagram of salting effects is suggested. The resolved multifaceted salting effects rely on the sensitive balance of the tripartite interaction among solutes, ions, and water. © 2011 American Institute of Physics

Corrosion Resistance of Some Stainless Steels in Chloride Solutions

Directory of Open Access Journals (Sweden)

Kasprzyk D.

2017-06-01

Full Text Available The present work compares corrosion behaviour of four types of S30403, S31603, S32615 austenitic and S32404 austenitic-ferritic stainless steels in chloride solutions (1%, 3% NaCl and in Ringer solution, at 37°C temperature. Corrosion resistance was determined by potentiodynamic polarization measurements and a thirty day immersion test conducted in Ringer solution. The immersion test was performed in term of biomedical application. These alloy were spontaneously passivated in all electrolytes, wherein S30403, S31603 and S32404 undergo pitting corrosion. Only S32615 containing 5.5% Si shows resistance to pitting corrosion.

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

International Nuclear Information System (INIS)

Sevast'yanov, A.I.; Chepovoj, V.I.

1988-01-01

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

Chemical and physical compatibility of an intravenous solution of epinephrine with calcium chloride.

Science.gov (United States)

Weeks, Phillip A; Teng, Yang; Wu, Lei; Sun, Mary; Yang, Zhen; Chow, Diana S-L

2014-01-01

An infusion of epinephrine combined with calcium chloride has been used historically as an intravenous inotropic solution to support critically ill heart failure patients with severe cardiogenic shock. There is no reliable data on the stability of this solution beyond three hours. This study was conducted to evaluate the chemical and physical compatibility of epinephrine (0.032 mg/mL) combined with calcium chloride (4 mg/mL) in a solution for intravenous administration up to 26 hours at room temperature. The chemical stability of epinephrine was monitored by measuring epinephrine concentrations using high-performance liquid chromatography. The physical compatibility of the mixture was determined by measuring spectrophotometric absorbance between 400 to 700 nm. Absorbance greater than 0.010 AU was considered an indicator of the presence of precipitation. The results showed epinephrine with calcium chloride was stable together in normal saline up to 26 hours at room temperature, irrespective of exposure to light. The absorbance of epinephrine throughout the study was less than 0.010 AU, indicating no significant precipitation. Conclusions indicate that epinephrine (0.032 mg/mL) combined with calcium chloride (4 mg/mL) in normal saline at room temperature is acceptably stable up to 26 hours for intravenous administration.

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

International Nuclear Information System (INIS)

Verissimo, Luis M.P.; Gomes, Joselaine C.S.; Romero, Carmen; Esteso, Miguel A.; Sobral, Abilio J.F.N.; Ribeiro, Ana C.F.

2013-01-01

Highlights: ► Diffusion coefficients of aqueous systems containing lactose and cadmium chloride. ► Influence of the lactose on the diffusion of cadmium chloride. ► Interactions between Cd 2+ 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

LOW TEMPERATURE PROCESS FOR THE REMOVAL AND RECOVERY OF CHLORIDES AND NITRATES FROM AQUEOUS NITRATE SOLUTIONS

Science.gov (United States)

Savolainen, J.E.

1963-01-29

A method is described for reducing the chloride content of a solution derived from the dissolution of a stainless steel clad nuclear fuel element with an aqua regia dissolution medium. The solutlon is adjusted to a nitric acid concentration in the range 5 to 10 M and is countercurrently contacted at room temperature with a gaseous oxide of nitrogen selected from NO, NO/sub 2/, N/sub 2/ O/sub 3/, and N/sub 2/O/sub 4/. Chlo ride is recovered from the contacted solution as nitrosyl chloride. After reduction of the chloride content, the solution is then contacted with gaseous NO to reduce the nitric acid molarity to a desired level. (AEC)

Borax methylene blue: a spectroscopic and staining study.

Science.gov (United States)

Donaldson, P T; Russo, A; Reynolds, C; Lillie, R D

1978-07-01

Borax methylene blue is quite stable at room temperatures of 22-25 C. At 30 C polychroming is slow; during 50 days in a water bath at this temperature the absorption peak moves from 665 to 656 nm. At 35 C, the absorption peak reaches 660 nm in 7 days, 654 nm in 14. At 60 C polychroming is rapid, the absorption peak reaching 640-620 nm in 3 days. When the pH of the borax methylene blue solutions, normally about 9.0, is adjusted to pH 6.5, the absorption peak remains at 665 nm even when incubated at 60 C for extended periods. When used as a blood stain 0.4 ml borax methylene blue (1% methylene blue in 1% borax), 4 ml acetone, 2 ml borax-acid phosphate buffer to bring the solution to pH 6.5, and distilled water to make 40 ml, with 0.2 ml 1% eosin added just before using, an excellent Nocht-Giemsa type stain is achieved after 30 minutes staining. The material plasmodia P. falciparum, P. vivax, and P. berghei stain moderate blue with dark red chromatin and green to black pigment granules. The study confirms Malachowski's 1891 results and explains Gautier's 1896-98 failure to duplicate it.

Synthesis and highly visible-induced photocatalytic activity of CNT-CdSe composite for methylene blue solution

Directory of Open Access Journals (Sweden)

Chen Ming-Liang

2011-01-01

Full Text Available Abstract Carbon nanotube-cadmium selenide (CNT-CdSe composite was synthesized by a facile hydrothermal method derived from multi-walled carbon nanotubes as a stating material. The as-prepared products were characterized by X-ray diffraction, scanning electron microscopy with energy dispersive X-ray analysis, transmission electron microscopy (TEM, and UV-vis diffuse reflectance spectrophotometer. The as-synthesized CNT-CdSe composite efficiently catalyzed the photodegradation of methylene blue in aqueous solutions under visible-light irradiation, exhibiting higher photocatalytic activity.

The spectroscopy and structure of some lanthanide chlorides in amide solutions

International Nuclear Information System (INIS)

Legendziewicz, J.; Bukietynska, K; Jezowsky-Trzebiatowska, B.

1974-01-01

The absorption spectra of Pr, Nd, Ho, and Er anhydrous and hydrated chlorides in formamide, methyl-, dimethyl-, and diethylformamide solutions have been investigated in the range of 8000 - 4200 cm -1 . By the Judd-Oefelt method of intensity analysis and by calculating the nepheloauxetic effect, the first coordination sphere of lanthanide ions and the approximate symmetry of amide solvates of anhydrous and hydrated lanthanide chlorides were determined. A difference between symmetry and coordination numbers for light and heavy lanthanide solvates has been found. Some considerations regarding the structure of lanthanide solvates and structure of amide molecules have been made. (B.T.)

Removal efficiency of methylene blue using activated carbon from waste banana stem: Study on pH influence

Science.gov (United States)

Misran, E.; Bani, O.; Situmeang, E. M.; Purba, A. S.

2018-02-01

The effort to remove methylene blue in artificial solution had been conducted using adsorption process. The abundant banana stem waste was utilized as activated carbon precursor. This study aimed to analyse the influence of solution pH to removal efficiency of methylene blue using activated carbon from banana stem as adsorbent. Activated carbon from banana stem was obtained by chemical activation using H3PO4 solution. Proximate analysis result showed that the activated carbon has 47.22% of fixed carbon. This value exhibited that banana stem was a potential adsorbent precursor. Methylene blue solutions were prepared at initial concentration of 50 ppm. The influence of solution pH was investigated with the use of 0.2 g adsorbent for 100 mL dye solution. The adsorption was conducted using shaker with at a constant rate of 100 rpm at room temperature for 90 minutes. The results showed that solution pH influenced the adsorption. The activated carbon from banana stem demonstrated satisfying performance since removal efficiencies of methylene blue were higher than 99%.

The determination of hydroxide and carbonate in concentrated sodium chloride solutions

NARCIS (Netherlands)

Roolvink, W.B.; Bos, M.

1980-01-01

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

Effect of alkaline earth metal and magnesium cations on cadmium extraction from chloride solutions by tributyl phosphate

International Nuclear Information System (INIS)

Prokuev, V.A.; Belousov, E.A.

1985-01-01

At 298 K thermodynamic constants of cadmium (2) extraction from chloride solutions of magnesium, calcium, strontium and barium by tributyl phosphate are calculated. It is established, that logarithm of the thermodynamic extraction constant is in a linear dependence from the change in the cation hydration enthalpy in agqueous solution. It is shown, that activity coefficient of neutral complex CdVCl 2 differs from one, and it is the higher the more stable the complex is in alkaline earth metal chloride solutions

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.

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

International Nuclear Information System (INIS)

Salyulev, A.B.; Kudyakov, V.Ya.; Smirnov, M.V.; Moskalenko, N.I.

1984-01-01

The coefficient of HfCl 4 and ZrCl 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 4 +HfCl 4 ). HfCl 4 and ZrCl 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

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 artifici...

Conductivity and electrochemical stability of concentrated aqueous choline chloride solutions

Science.gov (United States)

Grishina, E. P.; Kudryakova, N. O.

2017-10-01

The conductivity and electrochemical stability of choline chloride (ChCl) solutions with water contents ranging from 20 to 39 wt % are studied. Exposing ChCl to moist ambient air yields a highly concentrated aqueous solution that, as an electrolyte, exhibits the properties and variations in conductivity with temperature and concentration characteristic of other similar systems. Its electrochemical stability window, determined by cyclic voltammetry, is comparable to that of ChCl-based deep eutectic solvents (DESs). Products of the electrolysis of ChCl‒H2O mixtures seem to be less toxic than those of Reline, Ethaline, and Maline.

The use of chemical modified chitosan with succinic anhydride in the methylene blue adsorption

International Nuclear Information System (INIS)

Lima, Ilauro S.; Ribeiro, Emerson S.; Airoldi, Claudio

2006-01-01

The adsorption capacity of a-chitosan and its modified form with succinic anhydride was compared with the traditional adsorbent active carbon by using the dye methylene blue, employed in the textile industry. The isotherms for both biopolymers were classified as SSA systems in the Giles model, more specifically in L class and subgroup 3. The dye concentration in the supernatant in the adsorption assay was determined through electronic spectroscopy. By calorimetric titration thermodynamic data of the interaction between methylene blue and the chemically modified chitosan at the solid/liquid interface were obtained. The enthalpy of the dye/chitosan interaction gave 2.47 ± 0.02 kJ mol-1 with an equilibrium constant of 7350 ± 10 and for the carbon/dye interaction this constant gave 5951 ± 8. The spontaneity of these adsorptions are reflected by the free Gibbs energies of -22.1 ± 0.4 and -21.5 ± 0.2 kJ mol-1, respectively, found for these systems. This new adsorbent derived from a natural polysaccharide is as efficient as activated carbon. However 97% of the bonded dye can be eluted by sodium chloride solution, while this same operation elutes only 42% from carbon. Chitosan is efficient in dye removal with the additional advantage of being cheap, non-toxic, biocompatible and biodegradable. (author)

Methylene blue microbubbles as a model dual-modality contrast agent for ultrasound and activatable photoacoustic imaging

Science.gov (United States)

Jeon, Mansik; Song, Wentao; Huynh, Elizabeth; Kim, Jungho; Kim, Jeesu; Helfield, Brandon L.; Leung, Ben Y. C.; Goertz, David E.; Zheng, Gang; Oh, Jungtaek; Lovell, Jonathan F.; Kim, Chulhong

2014-01-01

Ultrasound and photoacoustic imaging are highly complementary modalities since both use ultrasonic detection for operation. Increasingly, photoacoustic and ultrasound have been integrated in terms of hardware instrumentation. To generate a broadly accessible dual-modality contrast agent, we generated microbubbles (a standard ultrasound contrast agent) in a solution of methylene blue (a standard photoacoustic dye). This MB2 solution was formed effectively and was optimized as a dual-modality contrast solution. As microbubble concentration increased (with methylene blue concentration constant), photoacoustic signal was attenuated in the MB2 solution. When methylene blue concentration increased (with microbubble concentration held constant), no ultrasonic interference was observed. Using an MB2 solution that strongly attenuated all photoacoustic signal, high powered ultrasound could be used to burst the microbubbles and dramatically enhance photoacoustic contrast (>800-fold increase), providing a new method for spatiotemporal control of photoacoustic signal generation.

Continuous adsorption of methylene blue dye on the maize stem ground tissue

Directory of Open Access Journals (Sweden)

Kojić Predrag S.

2017-01-01

Full Text Available Continuous adsorption of methylene blue from aqueous solutions onto maize stem ground tissue in column mode was investigated. The study encompassed the effects of important parameters such as flow rate, initial concentration of methylene blue, and bed depth on methylene blue removal from model solutions. The maximum adsorption capacity of the maize stem was 45.9 mg/g at the initial methylene blue concentration of 20 mg/L, bed height of 6.5 cm and flow rate of 8 mL/min. It was found that the breakthrough time for reaching saturation increased with a decrease in the flow rate, and also occurred earlier for a higher influent concentration. The breakthrough times increased with the bed depth, thus allowing a larger volume to be treated. The Adams-Bohart, Yoon-Nelson, Clark and artificial neural network models were used to predict the breakthrough curves. These models gave excellent approximations of the experimental behavior.[Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 172025

The Adsorption Efficiency of Chemically Prepared Activated Carbon from Cola Nut Shells by on Methylene Blue

Directory of Open Access Journals (Sweden)

Julius Ndi Nsami

2013-01-01

Full Text Available The adsorption of methylene blue from aqueous solution onto activated carbon prepared from cola nut shell has been investigated under batch mode. The influence of major parameters governing the efficiency of the process such as, solution pH, sorbent dose, initial concentration, and contact time on the removal process was investigated. The time-dependent experimental studies showed that the adsorption quantity of methylene blue increases with initial concentration and decreasing adsorbent dosage. The equilibrium time of 180 min was observed and maximum adsorption was favoured at pH 3.5. The dye removal using 0.1 g of adsorbent was more than 90%. This dosage (0.1 g was considered as the optimum dosage to remove methylene blue from aqueous solutions. The equilibrium adsorption data were analyzed by the Freundlich, Langmuir adsorption isotherm models. The kinetics of methylene blue solution was discussed by pseudo-first-order, pseudo-second-order, and Elovich models. The adsorption process follows the Elovich rate kinetic model, having a correlation coefficient in the range between 0.9811 and 1.

Polyvinyl chloride resin

International Nuclear Information System (INIS)

Kim, Hong Jae

1976-06-01

This book contains polyvinyl chloride resin industry with present condition such as plastic industry and polyvinyl chloride in the world and Japan, manufacture of polyvinyl chloride resin ; suspension polymerization and solution polymerization, extruding, injection process, hollow molding vinyl record, vacuum forming, polymer powders process, vinyl chloride varnish, vinyl chloride latex, safety and construction on vinyl chloride. Each chapter has descriptions on of process and kinds of polyvinyl chloride resin.

Corrosion of Alloys 600 ampersand 900 in acidified sulfate and chloride solutions

International Nuclear Information System (INIS)

Cullen, W.H.; Partridge, M.J.; Paine, J.P.N.

1993-01-01

A program is being performed currently: (1) to better quantify the susceptibility of Alloy 600 and 690 steam generator (SG) tubing materials to intergranular attack (IGA) and intergranular stress corrosion cracking (IGSCC) in acid solutions of the types that could concentrate in steam generator crevices, and (2) to establish the effectiveness of various remedial measures achieved through chemical additions to the secondary side coolant. The main test method is the exposure of stressed C-rings and expanded capsules of SG tubing to acid chloride and sulfate environments of various pH levels, temperatures, and applied potentials. Following these exposures, crack lengths are measured on metallographic cross-sections of the C-rings, and wastage rates calculated from weight loss, surface area and time. Test solutions are based on varying concentrations of sulfate and chloride species, with other contaminants added to some tests. The temperature dependence of the pH of the acidified solutions is calculated using the EPRI-developed MULTEQ computer program. High-temperature pH levels range from values of 2.5 to 7.6 at 315 degrees C, which is the nominal test temperature. Various accelerating and inhibiting factors (pH, temperature, solution composition and concentration, and applied electrochemical potential) are being evaluated

Pitting Corrosion Behavior of 304 SS and 316 SS Alloys in Aqueous Chloride and Bromide Solutions

Directory of Open Access Journals (Sweden)

Ibtehal Kareem Shakir

2018-01-01

Full Text Available The importance of the present work falls on the pitting corrosion behavior investigation of 304 SS and 316 SS alloys in 3.5 wt% of aqueous solution bearing with chloride and bromide anion at different solutions temperature range starting from (20-50oC due to the pitting corrosion tremendous effect on the economic, safety and materials loss due to leakage. The impact of solution temperatures on the pitting corrosion resistance at 3.5wt% (NaCl and NaBr solutions for the 304 SS and 316 SS has been investigated utilizing the cyclic polarization techniques at the potential range -400 to1000 mV vs. SCE at 40 mV/sec scan rate followed by the surface characterization employing Scanning Electron Microscope. The results show that a significant decline in the pitting corrosion potential Ep values of both stainless steel alloys in chloride and bromide solution during temperature increase attributed to the pitting corrosion potential decreased arises from the modification of the passive film properties. The surface examination using optical microscope and scanning electron microscope prove the occurring of higher pitting density over 304 SS in chloride solution than that observed in bromide solution with a non-circular lacy cover pitfall out at the center and falls inside the pits hall in comparison to the isolated circular lacy cover pit formed on 316 SS in 3.5wt% NaBr solution at 50 oC.

Methylene blue 1% solution on the prevention of intraperitoneal adhesion formation in a dog model

Directory of Open Access Journals (Sweden)

Marco Augusto Machado Silva

Full Text Available Intraperitoneal adhesions usually are formed after abdominal surgeries and may cause technical difficulties during surgical intervention, chronic abdominal pain and severe obstructions of the gastrointestinal tract. The current study aimed to evaluate the efficacy of methylene blue (MB 1% solution on the prevention of intraperitoneal postsurgical adhesion formation in a canine surgical trauma model. Twenty bitches were submitted to falciform ligament resection, omentectomy, ovariohysterectomy and scarification of a colonic segment. Prior to abdominal closure, 10 bitches received 1mg kg-1 MB intraperitoneally (MB group and 10 bitches received no treatment (control group, CT. On the 15th postoperative day the bitches were submitted to laparoscopy to assess adhesions. The mean adhesion scores were 13.9 (±5.6 for MB group and 20.5 (±6.4 for the CT group (P=0,043. In conclusion, the 1% MB solution was efficient on the prevention of intraperitoneal postoperative adhesion formation in bitches, especially those involving the colonic serosa.

Effect of a solution containing citrate/Methylene Blue/parabens on Staphylococcus aureus bacteria and biofilm, and comparison with various heparin solutions.

Science.gov (United States)

Sauer, Karin; Steczko, Janusz; Ash, Stephen R

2009-05-01

Some antibiotic solutions increase bacterial resistance and may cause toxic side effects. Heparin, frequently used as an anticoagulant in catheter lock solutions, may cause bleeding and stimulate biofilm formation. The aim of this study was to investigate the effect of a new antibacterial/antithrombotic solution, citrate/Methylene Blue/parabens (C/MB/P), versus various heparin solutions on the viability and the structure of preformed mature biofilms of Staphylococcus aureus bacteria. The degree of eradication of both planktonic and sessile microorganisms was evaluated. The changes in the structure of biofilms after exposure to C/MB/P and several concentrations of heparin were analysed by means of confocal laser scanning microscopy. COMSTAT image analysis was utilized to compare biofilm biomass, average and maximum height, surface coverage and roughness coefficient. Viability studies were performed on both biofilms and supernatant solutions. C/MB/P, in contrast to heparin solutions, significantly reduced biofilm biomass and thickness and reduced viability by 5 log when compared with saline treatment. No viable planktonic bacteria were detected and the few remaining biofilm cells appeared to be lysed. In contrast, most heparin solutions only reduced viability up to 1.0 log and failed to eradicate planktonic bacteria. C/MB/P has a rapid bactericidal effect on the preformed, mature biofilm of S. aureus. The structural changes of biofilms treated with C/MB/P, together with the observed log reduction of viable biofilm cells, confirmed the high potential of this solution to eliminate sessile bacteria. Furthermore, the tested solution entirely eliminated planktonic bacteria detached from the biofilm.

ISOCHORIC HEAT CAPACITY OF 1% AQUEOUS SOLUTION OF MAGNESIUM CHLORIDE

Directory of Open Access Journals (Sweden)

V. I. Dvoryanchikov

2016-01-01

Full Text Available Aim. The aim is to conduct an experimental study of isochoric heat capacity of 1% aqueous solution of magnesium chloride along the phase boundary curve.Method. In order to determine the isochoric heat capacity at the phase boundary curve we used the adiabatic calorimeter of KH. I. Amirkhanov.Results. Results of the study of the isochoric heat capacity depending on the temperature are given in tables and figures; the findings are compared with those of other researchers. When evaluating a complex system, we ought not to evaluate its effectiveness on the basis of only one criterion, even a very important, in this case must take into account the requirements of the technical, economic, environmental and of other natures.Conclusions. When solving optimization problems of efficiency in geothermal energy it is necessary to take into account the fact of the temperature dependence of the heat and density. The temperature dependence of the density and heat capacity in the calculations significantly affect the value of the efficiency criterion to be taken into account, otherwise the calculation error can be up to 20%. The data obtained from the isochoric heat capacity of aqueous solutions of magnesium chloride is compared with the data for water and aqueous solutions of NaCl and NaOH, obtained previously, which may be represented as a model of geothermal and sea water.

Corrosion behaviour of nickel during anodic polarization in chloride solution

International Nuclear Information System (INIS)

Memon, S.A.; Isani, A.A.; Memon, A.N.

1998-01-01

This research presents the effect of oxygen and nitrogen on the corrosion behaviour of nickel in the chloride solution, at the steady state polarized and unpolarized potentials. The additives were selected from those, which are used for bright nickel plating. It was observed that the agitation of electrolyte in a particular pH-(Cl)' range increase the potentials in comparison of the potentials to the un-agitated electrolytes. (author)

Methylene blue adsorption of GMZ bentonite and the effect of hyper-alkaline solution erosion

International Nuclear Information System (INIS)

Chen Bao; Zhang Huixin; Zhu Chunming; Chen Ping

2012-01-01

The method of combining the halo method with the spectrometer method, was used to study on the Methylene blue (MB) adsorption of Gaomiaozi (GMZ) bentonite, which had been eroded by hyper-alkaline solution, to investigate the mechanism of the effect of hyper-alkaline pore water on the buffer/backfill properties of GMZ bentonite. Results present, method employed in this article is brief and feasible, and high accuracy; The total specific surface area calculated by the test of MB adsorption is more accurate than the method of ethylene glycol monomethyl ether (EGIVIE). The MB adsorption of samples, which had been eroded by hyper-alkaline solution, decreases with the increase of the concentration of hyper-alkaline solution, and the change law agrees with the variation of the mass percentage of montmorillonite in bentonite tested by X- Ray diffraction (XRD). Therefore, the erosion of hyper-alkaline pore water might dissolve montmorillonite, which is the effective composition of bentonite, and destroy the tetrahedron- octahedron-tetrahedron (T-O-T) structure of montmorillonite, then lead to the decrease of cation exchange capability and the specific surface area of montmorillonite, and the the macroscopic expressions are the decrease of MB adsorption, the swelling potential and the increase of permeability. (authors)

Sorption of sulphur dioxide in calcium chloride and nitrate chloride liquids

International Nuclear Information System (INIS)

Trzepierczynska, I.; Gostomczyk, M.A.

1989-01-01

Flue gas desulphurization via application of suspensions has one inherent disadvantage: fixation of sulphur dioxide is very poor. This should be attributed to the low content of calcium ions which results from the solubility of the sorbing species. The solubility of sparingly soluble salts (CaO, CaCO 3 ) may be increased by decreasing the pH of the solution; yet, there is a serious limitation in this method: the corrosivity of the scrubber. The objective of this paper was to assess the sorbing capacity of two soluble calcium salts, calcium chloride and calcium nitrate, as a function of calcium ion concentration in the range of 20 to 82 kg/m 3 . It has been found that sorbing capacity increases with the increasing calcium ion concentration until the calcium concentration in the calcium chloride solution reaches the level of 60 kg/m 3 which is equivalent to the chloride ion content of ∼ 110 kg/m 3 . Addition of calcium hydroxide to the solutions brings about an increase in the sorbing capacity up to 1.6 kg/m 3 and 2.2 kg/m 3 for calcium chloride and calcium nitrate, respectively, as a result of the increased sorbent alkalinity. The sorption capacity of the solutions is considerably enhanced by supplementing them by acetate ions (2.8 to 13.9 kg/m 3 ). Increase in the sorption capacity of calcium nitrate solutions enriched with calcium acetate was approximately 30% as high as that of the chloride solutions enriched with calcium acetate was approximately 30% as high as that of the chloride solutions supplemented in the same way. (author). 12 refs, 7 refs, 4 tabs

Behavior of copper in acidic sulfate solution: Comparison with acidic chloride

Energy Technology Data Exchange (ETDEWEB)

Tromans, D.; Silva, J.C. [Univ. of British Columbia, Vancouver, British Columbia (Canada). Dept. of Metals and Materials Engineering

1997-03-01

The anodic polarization behavior of copper in a 0.1 M sulfuric acid (H{sub 2}SO{sub 4}) + 1 M sodium sulfate (Na{sub 2}SO{sub 4}) solution (pH = 2.0) was studied at room temperature under quiescent and stirred conditions. The behavior was compared with aqueous equilibria via construction of a potential-vs-pH (E-pH) diagram for the copper-sulfate-water (Cu-SO{sub 4}{sup 2}-H{sub 2}O) system. Interpretation of the behavior was aided by comparison with aqueous equilibria and polarization studies of copper in a 0.2 M hydrochloric acid (HCl) + 1 M sodium chloride (NaCl) solution(pH = 0.8). The initial anodic dissolution region in the acidic sulfate solution exhibited Tafel behavior with a slope consistent with formation of cupric ions (Cu{sup 2+}) whose rate of formation was charge-transfer controlled. At higher potentials, limiting current density (i{sub L}) behavior was observed under E-pH conditions that were consistent with formation of a film of copper sulfate pentahydrate (CuSO{sub 4} {degree} 5H{sub 2}O). Comparison of experimental i{sub L} values with those predicted by mass transport-controlled processes, using estimates of the diffusion layer thickness obtained from the mass transfer-influenced region of apparent Tafel behavior in the acidic chloride solution, were in sufficient agreement to indicate i{sub L} was controlled by the rate of dissolution of the CuSO{sub 4} {degree} 5H{sub 2}O film via transport of Cu{sup 2+} from the film-electrolyte interface into the bulk solution.

Biosorption of methylene blue from aqueous solution by fallen phoenix tree's leaves

International Nuclear Information System (INIS)

Han Runping; Zou Weihua; Yu Weihong; Cheng Shujian; Wang Yuanfeng; Shi Jie

2007-01-01

A new adsorbent, the fallen phoenix tree's leaf, has been investigated in order to remove methylene blue (MB) from aqueous solutions. Variables of the system, including contact time, leaf dose, solution pH, salt concentration and initial MB concentration, were adopted to study their effects on MB biosorption. The results showed that as the dose of leaf increased, the percentage of MB sorption increased accordingly. There was no significant difference about the quantity of MB adsorbed onto leaf as the pH was within the range 4.5-10.0. The salt concentration has negative effect on MB removal. The equilibrium data were analyzed using the Langmuir and the Freundlich isotherms. The results of non-linear regressive analysis are that the Langmuir isotherm is better fit than the Freundlich isotherm at different temperature according to the values of determined coefficients (R 2 ) and χ 2 -statistic (SS). The Langmuir monolayer saturation capacities of MB adsorbed onto leaf are 80.9, 83.8, 89.7 mg g -1 at 295, 309 and 323 K, respectively. Using the equilibrium concentration contents obtained at different temperatures, various thermodynamic parameters, such as ΔG o , ΔH o and ΔS o , have been calculated. The thermodynamics parameters of MB/leaf system indicate spontaneous and endothermic process. It was concluded that an increase in temperature be advantage to adsorb MB onto leaf

Methylene blue protects against TDP-43 and FUS neuronal toxicity in C. elegans and D. rerio.

Directory of Open Access Journals (Sweden)

Alexandra Vaccaro

Full Text Available The DNA/RNA-binding proteins TDP-43 and FUS are found in protein aggregates in a growing number of neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS and related dementia, but little is known about the neurotoxic mechanisms. We have generated Caenorhabditis elegans and zebrafish animal models expressing mutant human TDP-43 (A315T or G348C or FUS (S57Δ or R521H that reflect certain aspects of ALS including motor neuron degeneration, axonal deficits, and progressive paralysis. To explore the potential of our humanized transgenic C. elegans and zebrafish in identifying chemical suppressors of mutant TDP-43 and FUS neuronal toxicity, we tested three compounds with potential neuroprotective properties: lithium chloride, methylene blue and riluzole. We identified methylene blue as a potent suppressor of TDP-43 and FUS toxicity in both our models. Our results indicate that methylene blue can rescue toxic phenotypes associated with mutant TDP-43 and FUS including neuronal dysfunction and oxidative stress.

Methylene blue protects against TDP-43 and FUS neuronal toxicity in C. elegans and D. rerio.

Science.gov (United States)

Vaccaro, Alexandra; Patten, Shunmoogum A; Ciura, Sorana; Maios, Claudia; Therrien, Martine; Drapeau, Pierre; Kabashi, Edor; Parker, J Alex

2012-01-01

The DNA/RNA-binding proteins TDP-43 and FUS are found in protein aggregates in a growing number of neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS) and related dementia, but little is known about the neurotoxic mechanisms. We have generated Caenorhabditis elegans and zebrafish animal models expressing mutant human TDP-43 (A315T or G348C) or FUS (S57Δ or R521H) that reflect certain aspects of ALS including motor neuron degeneration, axonal deficits, and progressive paralysis. To explore the potential of our humanized transgenic C. elegans and zebrafish in identifying chemical suppressors of mutant TDP-43 and FUS neuronal toxicity, we tested three compounds with potential neuroprotective properties: lithium chloride, methylene blue and riluzole. We identified methylene blue as a potent suppressor of TDP-43 and FUS toxicity in both our models. Our results indicate that methylene blue can rescue toxic phenotypes associated with mutant TDP-43 and FUS including neuronal dysfunction and oxidative stress.

Mutual effect of zinc (2) and cadmium (2) during extraction with tributil phosphate from lithium chloride solutions

International Nuclear Information System (INIS)

Prokuev, V.A.; Belousov, E.A.

1980-01-01

Mutual effect of zinc and cadmium chlorides during extraction with tributyl phosphate at 5, 25 and 45 deg C from LiCl solutions is studied. The conclusion about the suppression of zinc and cadmium extraction by extracting macroelement (cadmium and zinc correspondingly) as the result of manifestation of general ion effect (lithium ion) in the extraction systems is made. It is established that the suppression of zink and cadmium extraction increases with the temperature decrease. On the base of the obtained experimental data the different type of extraction element distribution curves at the extraction from the muriatic solutions and lithium chloride solutions with tributyl phosphate is discussed

Microstructural characterization and electrochemical corrosion behavior of Incoloy 800 in sulphate and chloride solutions

International Nuclear Information System (INIS)

Mansur, Fabio Abud; Schvartzman, Monica Maria de Abreu Mendonca; Campos, Wagner Reis da Costa; Aguiar, Antonio Eugenio de; Chaim, Marcos Souza

2011-01-01

Corrosion has been the major cause of tube failures in steam generators (SG) tubes in nuclear power plants. Problems have resulted from impurities in the secondary water systems which are originated from leaks of cooling water. It is important to understand the compatibility of steam generator tube materials with the environment. This study presents the microstructural characterization and electrochemical behavior of the Incoloy 800 in sodium chloride and sodium sulphate aqueous solutions at 80 degree C. Potentiodynamic anodic polarization, cyclic polarization and open circuit potential (OCP) measurements were the electrochemical techniques applied in this work. The pitting resistance of Incoloy 800 in chloride plus sulphate mixtures were also examined. Experiments performed in solutions with different concentrations of Cl- and SO 4 2- ions in solution (200 ppb, 500 ppb, 1ppm, 5 ppm, 50 ppm and 100 ppm) showed that this concentrations range had no substantial effect on the anodic behavior of the alloy. After polarization no localized corrosion was found on the samples. (author)

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

Science.gov (United States)

Puertos, Enrique

2014-03-01

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

Reaction of calcium chloride with alkali metal chlorides in melts

International Nuclear Information System (INIS)

Savin, V.D.; Mikhajlova, N.P.

1984-01-01

Thermochemical characteristics of CaCl 2 reaction with sodium, potassium, rubidium and cesium chlorides in melts at 890 deg C are determined. The values of formation enthalpies of infinitely diluted by CaCl 2 solutions (ΔH) in the chloride row increase from -22 in NaCl to -47 kJ/mol of CaCl 2 in CsCl. With increasing the concentration of calcium chloride in the solution the ΔH values decrease. The regularities of separation from the solution of the CaCl 2 -CsCl system at 890 deg C of the CaCl 2 x CsCl in solid are studied. Formation enthalpies under the given conditions constitutes -70+-3 kJ/mol

Radiolysis of methylene blue studied by ESR

International Nuclear Information System (INIS)

Contineau, M.; Iliescu, C.; Ciureanu, M.

1983-01-01

Electron spin resonance spectra have been used to gain information on the mechanism of radiolysis of aqueous solutions of methylene blue. The identity and behaviour of the semiquinone radicals formed as intermediate reduction products were discussed for strongly acid and for alcaline solutions. In order to obtain information on the radiolytic mechanism in strongly acidic media, irradiation was performed in the presence of various types of scavengers: sodium formate, glucose, succinic acid, hydroquinone and D,L-α alanine. (author)

Use of Aspergillus wentii for biosorption of methylene blue from ...

African Journals Online (AJOL)

In this study, Aspergillus wentii was used as a biosorbent for the adsorption of methylene blue from aqueous solution. The effects of contact time, initial dye concentration, solution pH and temperature on biosorption were investigated. The contact time required (that is, the equilibrium time) for maximum dye biosorption was ...

Pourbaix Diagrams for Copper in 5 m Chloride Solution

International Nuclear Information System (INIS)

Beverskog, Bjoern; Pettersson, Sven-Olof

2002-12-01

Pourbaix diagrams for the copper in 5 molal chlorine at 5-100 deg C have been calculated. Predominance diagrams for dissolved copper containing species have also been calculated. Two different total concentrations of dissolved copper, 10 -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 CuCl 3 2- in acid and alkaline solutions. At higher potentials in acid solutions CuCl 3 2- is oxidized to CuCl 2 (aq), which at increasing potentials can form CuCI + , Cu 2+ or CuClO 3 + . Copper passivates by formation of Cu 2 O(cr), CuO(cr), or CUO 2 3 Cu(OH) 2 (s). Cu 2 O(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

Calcium Chloride and Calcium Gluconate in Neonatal Parenteral Nutrition Solutions without Cysteine: Compatibility Studies Using Laser Light Obscuration Methodology

Directory of Open Access Journals (Sweden)

Robert K. Huston

2018-02-01

Full Text Available There are no compatibility studies for neonatal parenteral nutrition solutions without cysteine containing calcium chloride or calcium gluconate using light obscuration as recommended by the United States Pharmacopeia (USP. The purpose of this study was to do compatibility testing for solutions containing calcium chloride and calcium gluconate without cysteine. Solutions of TrophAmine and Premasol (2.5% amino acids, containing calcium chloride or calcium gluconate were compounded without cysteine. Solutions were analyzed for particle counts using light obscuration. Maximum concentrations tested were 15 mmol/L of calcium and 12.5 mmol/L of phosphate. If the average particle count of three replicates exceeded USP guidelines, the solution was determined to be incompatible. This study found that 12.5 and 10 mmol/L of calcium and phosphate, respectively, are compatible in neonatal parenteral nutrition solutions compounded with 2.5% amino acids of either TrophAmine or Premasol. There did not appear to be significant differences in compatibility for solutions containing TrophAmine or Premasol when solutions were compounded with either CaCl2 or CaGlu-Pl. This study presents data in order to evaluate options for adding calcium and phosphate to neonatal parenteral nutrition solutions during shortages of calcium and cysteine.

Removal of Methylene Blue from Aqueous Solution by Activated Carbon Prepared from Pea Shells (Pisum sativum

Directory of Open Access Journals (Sweden)

Ünal Geçgel

2013-01-01

Full Text Available An activated carbon was prepared from pea shells and used for the removal of methylene blue (MB from aqueous solutions. The influence of various factors such as adsorbent concentration, initial dye concentration, temperature, contact time, pH, and surfactant was studied. The experimental data were analyzed by the Langmuir and Freundlich models of adsorption. The adsorption isotherm was found to follow the Langmuir model. The monolayer sorption capacity of activated carbon prepared from pea shell for MB was found to be 246.91 mg g−1 at 25 ∘C. Two simplified kinetic models including pseudo-first-order and pseudo-second-order equation were selected to follow the adsorption processes. Kinetic studies showed that the adsorption followed pseudo-second-order kinetic model. Various thermodynamic parameters such as , , and were evaluated. The results in this study indicated that activated carbon prepared from pea shell could be employed as an adsorbent for the removal of MB from aqueous solutions.

[Optimization of benzalkonium chloride concentration in 0.0015% tafluprost ophthalmic solution from the points of ocular surface safety and preservative efficacy].

Science.gov (United States)

Asada, Hiroyuki; Takaoka-Shichijo, Yuko; Nakamura, Masatsugu; Kimura, Akio

2010-06-01

Optimization of benzalkonium chloride (alkyl dimethylbenzylammonium chloride: BAK) concentration as preservative in 0.0015% tafluprost ophthalmic solution (Tapros 0.0015% ophthalmic solution), an anti-glaucoma medicine, was examined from the points of ocular surface safety and preservative efficacy. BAKC(12), which is dodecyl dimethylbenzylammonium chloride, and BAKmix, which is the mixture of dodecyl, tetradecyl and hexadecyl dimethylbenzylammonium chloride were used in this study. The effects of BAKC(12) concentrations and the BAK types, BAKC(12) and BAKmix, in tafluprost ophthalmic solution on ocular surface safety were evaluated using the in vitro SV 40-immobilized human corneal epithelium cell line (HCE-T). Following treatments of Tafluprost ophthalmic solutions with BAKC(12), its concentration dependency was observed on cell viability of HCE-T. The cell viability of HCE-T after treatment of these solutions with 0.001% to 0.003% BAKC(12) for 5 minutes were the same level as that after treatment of the solution without BAK. Tafluprost ophthalmic solution with 0.01% BAKC(12) was safer for the ocular surface than the same solution with 0.01% BAKmix. Preservatives-effectiveness tests of tafluprost ophthalmic solutions with various concentrations of BAKC(12) were performed according to the Japanese Pharmacopoeia (JP), and solutions with more than 0.0005% BAKC(12) conformed to JP criteria. It was concluded that 0.0005% to 0.003% of BAKC(12) in tafluprost ophthalmic solution was optimal, namely, well-balanced from the points of ocular surface safety and preservative efficacy.

α-keratin/Alginate Biosorbent for Removal of Methylene Blue on Aqueous Solution in a Batch System

Science.gov (United States)

Fadillah, G.; Putri, E. N. K.; Febrianastuti, S.; Munawaroh, H.; Purnawan, C.; Wahyuningsih, S.

2018-03-01

Methylene Blue (MB) is a cationic dyes which is commonly used in textile industries for coloring agent. The precence of MB in water caused some negative effect on the environment and human health. Many common technologies such as membrane filtration, electrophoresis and adsorption have been widely empolyed for removal of MB in water, but the adsorption technique still has advantages than the others. In this study, removal of MB used a biosorbent α-keratin/alginate (KA). The biosorbent KA was prepared by using the encapsulation technique in CaCl2 2 % (w/v) solution. The biosorbent was characterized by Fourier Transform Infrared (FTIR) and Scanning Electron Microscope (SEM). The effect of composition of α-keratin and alginate, the pH of solution and contact time on the adsorption were investigated. The optimum adsorption of MB in aqueous solution was found at the composition of α-keratin and alginate of 1:2 (w/w), the pH at 5.0 and contact time at 4 hours. The adsorption of MB on KA biosorbent was comparatively higher than α-keratin and alginate only. Adsorption of MB dyes in aqueous solution followed the Langmuir adsorption isotherm, and the dynamic adsorption model could be described through a pseudo-second order kinetics.

Removal of methylene blue dye from wastewater by using supported liquid memberane technology

Directory of Open Access Journals (Sweden)

Ashraf Muhammad Waqar

2016-06-01

Full Text Available The present work describes the application of Supported Liquid Membrane (SLM technology towards the removal and recovery of a cationic dye (Methylene Blue from aqueous solutions. Natural and non-toxic vegetable oils have been impregnated on microporous polymeric films of polyvinylidene fluoride (PVDF to constitute a liquid membrane. Different parameters affecting the transport, like pH of feed solution, acid concentration in the strip solution, initial dye concentration, oil types and stirring speeds have been investigated. Highest value of flux (1.7 × 10−5 mg/cm2/sec1 for methylene blue dye was achieved with sunflower oil impregnated on the PVDF support, with pH maintained at 12 in the feed solution and 0.3 M hydrochloric acid concentration in the strip solution. It took 6 hours to transport maximum amount of dye under optimum conditions.

Assessing the effectiveness of 30% sodium chloride aqueous solution for the preservation of fixed anatomical specimens: a 5-year follow-up study.

Science.gov (United States)

de Oliveira, Fabrício Singaretti

2014-07-01

Anatomical specimens used in human or veterinary anatomy laboratories are usually prepared with formaldehyde (a cancerous and teratogenic substance), glycerin (an expensive and viscous fluid), or ethanol (which is flammable). This research aimed to verify the viability of an aqueous 30% sodium chloride solution for preservation of anatomical specimens previously fixed with formaldehyde. Anatomical specimens of ruminant, carnivorous, equine, swine and birds were used. All were previously fixed with an aqueous 20% formaldehyde solution and held for 7 days in a 10% aqueous solution of the same active ingredient. During the first phase of the experiment, small specimens of animal tissue previously fixed in formaldehyde were distributed in vials with different concentrations of formaldehyde, with or without 30% sodium chloride solution, a group containing only 30% sodium chloride, and a control group containing only water. During this phase, no contamination was observed in any specimen containing 30% sodium chloride solution, whether alone or in combination with different concentrations of formaldehyde. In the second phase of the experiment, the 30% sodium chloride solution, found to be optimal in the first phase of the experiment, was tested for its long-term preservation properties. For a period of 5 years, the preserved specimens were evaluated three times a week for visual contamination, odors, and changes in color and texture. There was no visual contamination or decay found in any specimen. Furthermore, no strange odors, or changes in color or softness were noted. The 30% sodium chloride solution was determined to be effective in the preservation of anatomic specimens previously fixed in formaldehyde. © 2014 Anatomical Society.

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}.

Solvation of magnesium dication: molecular dynamics simulation and vibrational spectroscopic study of magnesium chloride in aqueous solutions.

Science.gov (United States)

Callahan, Karen M; Casillas-Ituarte, Nadia N; Roeselová, Martina; Allen, Heather C; Tobias, Douglas J

2010-04-22

Magnesium dication plays many significant roles in biochemistry. While it is available to the environment from both ocean waters and mineral salts on land, its roles in environmental and atmospheric chemistry are still relatively unknown. Several pieces of experimental evidence suggest that contact ion pairing may not exist at ambient conditions in solutions of magnesium chloride up to saturation concentrations. This is not typical of most ions. There has been disagreement in the molecular dynamics literature concerning the existence of ion pairing in magnesium chloride solutions. Using a force field developed during this study, we show that contact ion pairing is not energetically favorable. Additionally, we present a concentration-dependent Raman spectroscopic study of the Mg-O(water) hexaaquo stretch that clearly supports the absence of ion pairing in MgCl(2) solutions, although a transition occurring in the spectrum between 0.06x and 0.09x suggests a change in solution structure. Finally, we compare experimental and calculated observables to validate our force field as well as two other commonly used magnesium force fields, and in the process show that ion pairing of magnesium clearly is not observed at higher concentrations in aqueous solutions of magnesium chloride, independent of the choice of magnesium force field, although some force fields give better agreement to experimental results than others.

Evaluation of chloride-ion-specific electrodes as in situ chemical sensors for monitoring total chloride concentration in aqueous solutions generated during the recovery of plutonium from molten salts used in plutonium electrorefining operations

International Nuclear Information System (INIS)

Smith, W.H.

1992-10-01

Two commercially available chloride-ion-specific electrodes (CLISEs), a solid-state type and a membrane type, were evaluated as potential in situ chemical sensors for determining total chloride ion concentration in mixed sodium chloride/potassium chloride/hydrochloric acid solutions generated during the recovery of plutonium from molten salts used in plutonium electrorefining operations. Because the response of the solid-state CLISE was closer than was the response of the membrane-type CLISE to the theoretical response predicted by the Nernst equation, the solid-state CLISE was selected for further evaluation. A detailed investigation of the characteristics of the chloride system and the corresponding CLISE response to concentration changes suggested four methods by which the CLISE could be used either as a direct, in situ sensor or as an indirect sensor through which an analysis could be performed on-line with a sample extracted from the process solution

Pourbaix Diagrams for Copper in 5 m Chloride Solution

Energy Technology Data Exchange (ETDEWEB)

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

2002-12-01

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

Regularities in the association of polymethacrylic acid with benzethonium chloride in aqueous solutions

Science.gov (United States)

Tugay, A. V.; Zakordonskiy, V. P.

2006-06-01

The association of cationogenic benzethonium chloride with polymethacrylic acid in aqueous solutions was studied by nephelometry, conductometry, tensiometry, viscometry, and pH-metry. The critical concentrations of aggregation and polymer saturation with the surface-active substance were determined. A model describing processes in such systems step by step was suggested.

Pitting corrosion resistance of high alloy OCTG in ferric chloride solution

International Nuclear Information System (INIS)

Masamura, K.; Yamamoto, S.; Matsushima, I.

1986-01-01

The effects of alloying elements and precipitated phases on the corrosion rate of high alloy OCTG in the ferric chloride solution have been evaluated. The corrosion rate of Fe-Cr-Ni-Mo alloys without precipitated phases, e.g. carbides and sigma phase, can be estimated from the composition using the following equation: log(C.R.)=-0.144xPRE-7690/(273+T)+28.6 where C.R. is the corrosion rate in g/m/sup 2//hr; PRE is Cr+3Mo+16N in percent and T is the test temperature in 0 C. The activation energies of the ferric chloride test are almost the same regardless of PRE or Ni content when no detrimental phase precipitates. When carbides or the sigma phase precipitate, the corrosion rate is higher and the activation energy is lowered. This suggests that secondary phases give preferential sites for initiation of pitting corrosion

Degradation of methylene blue by radio frequency plasmas in water under ultraviolet irradiation

Energy Technology Data Exchange (ETDEWEB)

Maehara, Tsunehiro, E-mail: maehara@phys.sci.ehime-u.ac.jp [Graduate School of Science and Engineering, Ehime University, Matsuyama 790-8577 (Japan); Nishiyama, Kyohei; Onishi, Shingo; Mukasa, Shinobu; Toyota, Hiromichi [Graduate School of Science and Engineering, Ehime University, Matsuyama 790-8577 (Japan); Kuramoto, Makoto [Integrated Center for Science, Ehime University, Matsuyama 790-8577 (Japan); Nomura, Shinfuku [Graduate School of Science and Engineering, Ehime University, Matsuyama 790-8577 (Japan); Kawashima, Ayato [Faculty of Agriculture, Ehime University, Matsuyama 790-8566 (Japan)

2010-02-15

The degradation of methylene blue by radio frequency (RF) plasmas in water under ultraviolet (UV) irradiation was studied experimentally. When the methylene blue solution was exposed to RF plasma, UV irradiation from a mercury vapor lamp enhanced degradation significantly. A lamp without power supply also enhanced degradation since weak UV light was emitted weakly from the lamp due to the excitation of mercury vapor by stray RF power. Such an enhancement is explained by the fact that after hydrogen peroxide is produced via the recombination process of OH radicals around the plasma, OH radicals reproduced from hydrogen peroxide via the photolysis process degrade methylene blue.

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)

Wang, Yafei; Cheng, Guangxu; Wu, Wei; Qiao, Qiao; Li, Yun; Li, Xiufeng

2015-01-01

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

The Role of Thiosulfate Ions in the Initiation of Crevice Corrosion of 316 Stainless Steel in Chloride Solution

International Nuclear Information System (INIS)

Gad, M.M.A.; El-Sayed, A.A.

2008-01-01

Electrochemical techniques have been applied to study the crevice corrosion behavior of 316 L stainless steel in both 0.5 and 2 M NaCl solution with and without thiosulfate additions. In this investigation, the crevice corrosion of the tested material was studied in both bulk solution environment (0.5 M NaCl) as well as in chloride solutions simulating those formed inside crevices of stainless steels. A metal to nonmetal assembly, in which disc type specimens were faced to a PTFE crevice former, is used for bulk solution tests. Crevice- free specimens of cylindrical shape were used for the determination of the composition of solutions formed inside crevices (known as CCS). Potentiodynamic runs in extremely low ph solution (2 M NaCl solution with and without 0.01 M Na 2 SO 3 addition) were conducted to determine the ph at which the passive film breaks down (d ph). The d ph value was found to be a function of both chloride and thiosulfate ions. Cyclic potentiodynamic technique was used in evaluating the electrochemical corrosion performance of the tested alloy in bulk 0.5 M NaCl solution with and without 0.01 M Na 2 SO 3 addition. Results indicated that the presence of thiosulfate, combined with chloride ions led to a notable decrease in the corrosion resistance of the tested material. The deleterious effect of thiosulfates was discussed in terms of passivity breakdown and formation of reduced sulfur species within active crevices leading to the formation of H 2 S, which enhances the anodic dissolution of iron

Scavenging behaviour of meranti sawdust in the removal of methylene blue from aqueous solution

International Nuclear Information System (INIS)

Ahmad, A.; Rafatullah, M.; Sulaiman, O.; Ibrahim, M.H.; Hashim, R.

2009-01-01

Meranti (Philippine mahogany) sawdust, an inexpensive material, showed strong scavenging behaviour through adsorption for the removal of methylene blue (MB) from aqueous solution. Batch studies were performed to evaluate and optimize the effects of various parameters such as contact time, pH, initial dye concentrations and adsorbent dosage. Langmuir, Freundlich and Temkin isotherms were used to analyze the equilibrium data at different temperatures. The experimental data fitted well with the Langmuir adsorption isotherm, indicating thereby the mono layer adsorption of the dye. The monolayer sorption capacity of meranti sawdust for MB was found to be 120.48, 117.64, 149.25 and 158.73 mg/g at 30, 40, 50 and 60 deg. C, respectively. Thermodynamic calculations showed that the MB adsorption process is endothermic and spontaneous in nature. Kinetic studies showed that the adsorption followed a pseudo-second-order kinetic model. The results indicated that the meranti sawdust could be an alternative material in place of more costly adsorbents used for dye removal.

Enhanced Photocatalytic Performance of NiO-Decorated ZnO Nanowhiskers for Methylene Blue Degradation

Directory of Open Access Journals (Sweden)

I. Abdul Rahman

2014-01-01

Full Text Available ZnO nanowhiskers were used for photodecomposition of methylene blue in aqueous solution under UV irradiation. The rate of methylene blue degradation increased linearly with time of UV irradiation. 54% of degradation rate was observed when the ZnO nanowhiskers were used as photocatalysts for methylene blue degradation for 80 min under UV irradiation. The decoration of p-type NiO nanoparticles on n-type ZnO nanowhiskers significantly enhanced photocatalytic activity and reached 72% degradation rate of methylene blue by using the same method. NiO-decorated ZnO was recycled for second test and shows 66% degradation from maximal peak of methylene blue within the same period. The increment of photocatalytic activity of NiO-decorated ZnO nanowhiskers was explained by the extension of the electron depletion layer due to the formation of nanoscale p-n junctions between p-type NiO and n-type ZnO. Hence, these products provide new alternative proficient photocatalysts for wastewater treatment.

Adsorption and photodegradation of methylene blue by iron oxide impregnated on granular activated carbons in an oxalate solution

International Nuclear Information System (INIS)

Kadirova, Zukhra C.; Katsumata, Ken-ichi; Isobe, Toshihiro; Matsushita, Nobuhiro; Nakajima, Akira; Okada, Kiyoshi

2013-01-01

The photocatalytic adsorbents BAU-OA, BAU-CL and BAU-HA with varying iron oxide content (9–10 mass%) were prepared by heat treatment at 250 °C from commercial activated carbon (BAU) impregnated with iron oxalate, chloride, tris-benzohydroxamate, respectively. The XRD patterns showed amorphous structure in the BAU-CL sample (S BET 50 m 2 /g) and low crystallinity (as FeOOH and Fe 2 O 3 phases) in the BAU-HA and BAU-OA samples (S BET 4 and 111 m 2 /g, respectively). The methylene blue adsorption capacities was decreased in order of BAU-OA app ) was increased in same order BAU-HA < BAU-CL < BAU-OA under the standard experimental conditions (initial MB concentrations 0.015–0.025 mM; sample content – 10 mg/l; initial oxalic acid concentration – 0.43 mM; pH 3–4; UV illumination). The process included high efficiency combination of adsorption, heterogeneous and homogeneous catalysis under UV and solar lights illumination without addition of hydrogen peroxide. The detoxification of water sample containing organic dyes was confirmed after combined sorption-photocatalytic treatment.

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

International Nuclear Information System (INIS)

Postlethwaite, J.

1991-12-01

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

Corrosion behavior of a superduplex stainless steel in chloride aqueous solution

Science.gov (United States)

Dabalà, Manuele; Calliari, Irene; Variola, Alessandra

2004-04-01

Super duplex stainless steels (SDSS) have been widely used as structural materials for chemical plants (especially in those engaged in phosphoric acid production), in the hydrometallurgy industries, and as materials for offshore applications due to their excellent corrosion resistance in chloride environments, compared with other commercial types of ferritic stainless steels. These alloys also possess superior weldability and better mechanical properties than austenitic stainless steels. However, due to their two-phase structure, the nature of which is very dependent on their composition and thermal history, the behavior of SDSS regarding localized corrosion appears difficult to predict, especially in chloride environments. To improve their final properties, the effect of the partition of the alloying elements between the two phases, and the composition and microstructure of each phase are the key to understanding the localized corrosion phenomena of SDSS. This paper concerns the effects of the SDSS microstructure and heat treatment on the SDSS corrosion resistance in aqueous solutions, containing different amounts of NaCl at room temperature.

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

International Nuclear Information System (INIS)

Carranza, Ricardo M.; Rodriguez, Martin A.

2007-01-01

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)

Sorption characteristics of methylene blue onto Nypa fruiticans lignin ...

African Journals Online (AJOL)

The sorption characteristics of soda lignin extracted from Nypa fruiticans for the removal of methylene blue dye from aqueous solution was investigated in this study, as an ethically sound way of utilizing this unexploited abundant natural resource. Equilibrium data were fitted to the Langmuir and Freundlich isotherm ...

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...

Hydrolysis of cupric chloride in aqueous ammoniacal ammonium chloride solutions

Directory of Open Access Journals (Sweden)

Limpo, J. L.

1995-06-01

Full Text Available Cupric solubility in the CuCl₂-NH₄Cl-NH₃-H₂O system for chloride concentrations lower than 4 molal in the temperature range 25-60 °C was studied. The experimental results show that for chloride concentration between 3.0 and 1.0 molal the cupric solubility is determined by the solubility of the cupric hydroxychloride Cu(OH_1.5Cl_0.5. For a chloride concentration value of 4.0 molal, there are two cupric compounds, the hydroxychloride Cu(OH_1.5Cl_0.5 or the diammine chloride Cu(NH₃₂Cl₂, on which the solubility of Cu(II depends, according to the temperature and the value of the ratio [NH₃]_Total/[Cu]_Total.

Se estudia la solubilidad del Cu(II en el sistema CuCl₂-NH₄Cl-NH₃-H₂O para concentraciones de cloruro inferiores a 4 molal en el intervalo de temperaturas 25-60 °C. Los resultados experimentales muestran que, para concentraciones de cloruros comprendidas entre 3,0 y 1,0 molal, la solubilidad cúprica viene determinada por la solubilidad del hidroxicloruro cúprico, Cu(OH_1.5Cl_0.5. Para concentraciones de cloruro 4,0 molal, existen dos compuestos cúpricos, el hidroxicloruro, Cu(OH_1.5Cl_0.5 o el cloruro de diamina, Cu(NH₃₂Cl₂, de los que, de acuerdo con la temperatura y con el valor de la relación [NH₃]_Total/[Cu]_Total depende la solubilidad del Cu(II.

Adsorption and purification of radiogallium in hydrochloric acid and metal chloride solutions by non-ionic resin of macro-reticular type

International Nuclear Information System (INIS)

Imai, Kiyoko; Watari, Kazuo; Ohno, Shigeru; Ohmiya, Toshinobu; Kuroda, Emi; Izawa, Masami.

1986-01-01

Adsorption behavior of radiogallium ( 67 Ga, 68 Ga) on non-ionic MR resin (XAD-7) from hydrochloric acid, lithium chloride and other metal chloride solutions, and purification of 68 Ga by this resin were studied. Radiogallium was adsorbed on XAD-7 rapidly and quantitatively from the solution of higher chloride concentration than 6M. The adsorption behavior is similar to that obtained with 59 Fe and 195 Au previously. Based on adsorption data, elimination of trace amount of 68 Ge commonly contained in 68 Ga milked from a 68 Ge/ 68 Ga generator was tried. When 68 Ga-6M hydrochloric acid solution containing 68 Ge was passed through a XAD-7 column, all the activity was transferred on the column. After eliminating 68 Ge fraction with 3M hydrochloric acid, 68 Ga was obtained in high purity by eluting with 0.1M hydrochloric acid. (author)

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.

Removal of congo red and methylene blue from waste water using coagulation

International Nuclear Information System (INIS)

Ghaffar, S.; Nosheen, S.; Ahmad, N.

2011-01-01

The textile industry has been condemned as being one of the world's worst offenders in terms of pollution Because of increasing population and industrial developments, a huge amount of wastewater is discharged to the environment above the level that the nature can eliminate. Many techniques like oxidation, reduction, physical treatment and biological method are available for removal of colored dyes from wastewater. The work presented here involved the decolorisation of wastewater containing congo red and methylene blue using various coagulants such as alum, bentonite and lime. The effect of various experimental factors such as dosage of coagulants, contact time between coagulant and dye and concentration of dyes and working environment like shaking and static was studied. Under static condition alum give almost 43% removal of congo red while with 10 minutes shaking 74 % removal of 80 dye was achieved with same coagulant. The highest removal of congo red was found to be 99.5 % by using alum after 30 minutes of shaking but in case of methylene blue it intensified the color and gave negative results. Lime gave only 33 % color removal of congo red under static conditions while 57% color was removed under shaking conditions. Maximum color removal achieved by lime was 89% at 40 minutes with shaking condition. Lime gave 60% removal of methylene blue in static condition and 90% removal in shaking condition and maximum absorbance at 80 ppm was 90%. Bentonite also used for the removal of methylene blue and gave 89% removal in shaking condition. By increasing shaking time %age removal increased to 100% at 40 min. And amount of coagulant increased the removal efficiency it attained 100% in both lime and bentonite coagulant for methylene blue Overall alum was found to be better coagulant for the removal of congo red from its aqueous solution. Lime and bentonite both proved better and economical for removal of methylene blue from aqueous solution at lab scale. (author)

Effect of Organic Acid Additions on the General and Localized Corrosion Susceptibility of Alloy 22 in Chloride Solutions

Energy Technology Data Exchange (ETDEWEB)

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

2007-08-28

Electrochemical studies such as cyclic potentiodynamic polarization (CPP) and electrochemical impedance spectroscopy (EIS) were performed to determine the corrosion behavior of Alloy 22 (N06022) in 1M NaCl solutions at various pH values from acidic to neutral at 90 C. All the tested material was wrought Mill Annealed (MA). Tests were also performed in NaCl solutions containing weak organic acids such as oxalic, acetic, citric and picric. Results show that the corrosion rate of Alloy 22 was significantly higher in solutions containing oxalic acid than in solutions of pure NaCl at the same pH. Citric and picric acids showed a slightly higher corrosion rate, and acetic acid maintained the corrosion rate of pure chloride solutions at the same pH. Organic acids revealed to be weak inhibitors for crevice corrosion. Higher concentration ratios, compared to nitrate ions, were needed to completely inhibit crevice corrosion in chloride solutions. Results are discussed considering acid dissociation constants, buffer capacity and complex formation constants of the different weak acids.

Influence of temperature, chloride ions and chromium element on the electronic property of passive film formed on carbon steel in bicarbonate/carbonate buffer solution

Energy Technology Data Exchange (ETDEWEB)

Li, D.G. [School of Materials Science and Engineering, Xi' an Jiaotong University, Xi' an 710049 (China); Tubular Goods Research Center of CNPC, Xi' an 710065 (China)], E-mail: dangguoli78@yahoo.com.cn; Feng, Y.R.; Bai, Z.Q. [Tubular Goods Research Center of CNPC, Xi' an 710065 (China); Zhu, J.W.; Zheng, M.S. [School of Materials Science and Engineering, Xi' an Jiaotong University, Xi' an 710049 (China)

2007-11-01

The influences of temperature, chloride ions and chromium element on the electronic property of passive film formed on carbon steel in NaHCO{sub 3}/Na{sub 2}CO{sub 3} buffer solution are investigated by capacitance measurement and electrochemical impedance spectroscopy (EIS). The results show that the passive film appears n-type semiconductive character; with increasing the solution temperature, the addition of chromium into carbon steel and increasing the concentration of chloride ions, the slopes of Mott-Schottky plots decrease, which indicates the increment of the defect density in the passive film. EIS results show that the transfer impedance R{sub 1} and the diffusion impedance W decrease with increasing the solution temperature, with the addition of chromium into carbon steel and with increasing the chloride ions concentration. It can be concluded that the corrosion protection effect of passive film on the substrate decreases with increasing the solution temperature, adding chromium into carbon steel and increasing chloride ions concentration.

Effect of chloride in soil solution on the plant availability of biosolid-borne cadmium.

Science.gov (United States)

Weggler, Karin; McLaughlin, Michael J; Graham, Robin D

2004-01-01

Increasing chloride (Cl) concentration in soil solution has been shown to increase cadmium (Cd) concentration in soil solution and Cd uptake by plants, when grown in phosphate fertilizer- or biosolid-amended soils. However, previous experiments did not distinguish between the effect of Cl on biosolid-borne Cd compared with soil-borne Cd inherited from previous fertilizer history. A factorial pot experiment was conducted with biosolid application rates of 0, 20, 40, and 80 g biosolids kg(-1) and Cl concentration in soil solution ranging from 1 to 160 mM Cl. The Cd uptake of wheat (Triticum aestivum L. cv. Halberd) was measured and major cations and anions in soil solution were determined. Cadmium speciation in soil solution was calculated using GEOCHEM-PC. The Cd concentration in plant shoots and soil solution increased with biosolid application rates up to 40 g kg(-1), but decreased slightly in the 80 g kg(-1) biosolid treatment. Across biosolid application rates, the Cd concentration in soil solution and plant shoots was positively correlated with the Cl concentration in soil solution. This suggests that biosolid-borne Cd is also mobilized by chloride ligands in soil solution. The soil solution CdCl+ activity correlated best with the Cd uptake of plants, although little of the variation in plant Cd concentrations was explained by activity of CdCl+ in higher sludge treatments. It was concluded that chlorocomplexation of Cd increased the phytoavailability of biosolid-borne Cd to a similar degree as soil (fertilizer) Cd. There was a nonlinear increase in plant uptake and solubility of Cd in biosolid-amended soils, with highest plant Cd found at the 40 g kg(-1) rate of biosolid application, and higher rates (80 g kg(-1)) producing lower plant Cd uptake and lower Cd solubility in soil. This is postulated to be a result of Cd retention by CaCO3 formed as a result of the high alkalinity induced by biosolid application.

Crevice-corrosion kinetics on titanium and a Ti-Ni-Mo alloy in chloride solutions at elevated temperature

International Nuclear Information System (INIS)

McKay, P.

1987-01-01

The results of an electrochemical investigation of the crevice-corrosion kinetics on titanium and a dilute Ti-Ni-Mo alloy (0.8% Ni, 0.3% Mo), in concentrated chloride solutions at 150 0 C, are presented. The current-time transients, obtained on creviced electrodes under both potentiostatic and galvanic (coupling to a large area of uncreviced titanium) conditions, are interpreted in terms of crevice acidification leading to the formation of an active-passive cell, maintained by iR gradient in the electrolyte. The passivating effect of the Ni and Mo additions on the crevice corrosion of titanium are described, together with the results of an electrochemical study, carried out in bulk acid chloride solutions, that were used to substantiate a proposed mechanism of crevice passivation. (author)

Adsorption of methylene blue dye from aqueous solution by sugar extracted spent rice biomass.

Science.gov (United States)

Ur Rehman, Muhammad Saif; Kim, Ilgook; Han, Jong-In

2012-10-15

This study was aimed at using sugar extracted spent rice biomass (SRB) as a potential adsorbent to remove methylene blue (MB) dye from aqueous solution. The SRB was used without any modification. A three factor full factorial experimental design (2(3)) was employed to investigate the effect of factors (adsorbent dose, dye concentration, temperature) and their interaction on the adsorption capacity and color removal. Two levels for each factor were used; adsorbent dose (0.25-0.5g/100mL), dye concentration (25-50mg/L), and temperature (25-45°C). Initial dye concentration and adsorbent dosage were found as significant factors for the adsorption of MB dye. Langmuir isotherm (R(2)>0.998) best explained the equilibrium of MB adsorption on SRB with monolayer adsorption capacity of 8.13mg/g. The pseudo-second order model (R(2)>0.999) was best fitted to explain the adsorption kinetics. Thermodynamic investigation revealed that the adsorption process was spontaneous, endothermic, and was feasible to treat dyeing wastewater. Copyright © 2012 Elsevier Ltd. All rights reserved.

A Facile, Choline Chloride/Urea Catalyzed Solid Phase Synthesis of Coumarins via Knoevenagel Condensation

Directory of Open Access Journals (Sweden)

Hosanagara N. Harishkumar

2011-01-01

Full Text Available The influence of choline chloride/urea ionic liquid in solid phase on the Knoevenagel condensation is demonstrated. The active methylene compounds such as meldrum’s acid, diethylmalonate, ethyl cyanoacetate, dimethylmalonate, were efficiently condensed with various salicylaldehydes in presence of choline chloride/urea ionic liquid without using any solvents or additional catalyst. The reaction is remarkably facile because of the air and water stability of the catalyst, and needs no special precautions. The reactions were completed within 1hr with excellent yields (95%. The products formed were sufficiently pure, and can be easily recovered. The use of ionic liquid choline chloride/urea in solid phase offered several significant advantages such as low cost, greater selectivity and easy isolation of products.

Adsorption and photodegradation of methylene blue by iron oxide impregnated on granular activated carbons in an oxalate solution

Energy Technology Data Exchange (ETDEWEB)

Kadirova, Zukhra C., E-mail: zuhra_kadirova@yahoo.com [Institute of General and Inorganic Chemistry, Academy of Sciences of the Republic of Uzbekistan, Mirzo Ulugbek Str. 77a, Tashkent 100170 (Uzbekistan); Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori, Yokohama 226-8503 (Japan); Katsumata, Ken-ichi [Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori, Yokohama 226-8503 (Japan); Isobe, Toshihiro [Department of Metallurgy and Ceramics Science, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro, Tokyo 152-8552 (Japan); Matsushita, Nobuhiro [Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori, Yokohama 226-8503 (Japan); Nakajima, Akira [Department of Metallurgy and Ceramics Science, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro, Tokyo 152-8552 (Japan); Okada, Kiyoshi [Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori, Yokohama 226-8503 (Japan)

2013-11-01

The photocatalytic adsorbents BAU-OA, BAU-CL and BAU-HA with varying iron oxide content (9–10 mass%) were prepared by heat treatment at 250 °C from commercial activated carbon (BAU) impregnated with iron oxalate, chloride, tris-benzohydroxamate, respectively. The XRD patterns showed amorphous structure in the BAU-CL sample (S{sub BET} 50 m{sup 2}/g) and low crystallinity (as FeOOH and Fe{sub 2}O{sub 3} phases) in the BAU-HA and BAU-OA samples (S{sub BET} 4 and 111 m{sup 2}/g, respectively). The methylene blue adsorption capacities was decreased in order of BAU-OA < BAU-CL < BAU-HA sample and the adsorption followed Langmuir model. The apparent MB photodegradation rate constant (k{sub app}) was increased in same order BAU-HA < BAU-CL < BAU-OA under the standard experimental conditions (initial MB concentrations 0.015–0.025 mM; sample content – 10 mg/l; initial oxalic acid concentration – 0.43 mM; pH 3–4; UV illumination). The process included high efficiency combination of adsorption, heterogeneous and homogeneous catalysis under UV and solar lights illumination without addition of hydrogen peroxide. The detoxification of water sample containing organic dyes was confirmed after combined sorption-photocatalytic treatment.

Reduction of potassium permanganate solution by γ-irradiated sodium chloride [Paper No. RD-21

International Nuclear Information System (INIS)

Phansalkar, V.K.; Ravishankar, D.

1982-01-01

The dissolution of γ-irradiated sodium chloride in potassium permanganate solution results in the reduction of MnO 4 - ions. This has been inferred from spectrophotometric studies. This has been explained on the basis of interaction of colour centres with MnO 4 - ions. The extent to which MnO 4 - ions are reduced are found to vary with

Evaluation of La-Doped Mesoporous Bioactive Glass as Adsorbent and Photocatalyst for Removal of Methylene Blue from Aqueous Solution

Directory of Open Access Journals (Sweden)

Liying Li

2015-01-01

Full Text Available A series of La-doped mesoporous bioactive glass (BG-La materials with excellent biosafety and hypotoxicity have been prepared and tested as adsorbent. The study was aimed to evaluate the possibility of utilizing BG-La for the adsorptive removal of methylene blue (MB from aqueous solution and test the adsorption and desorption behavior of this new material. The process parameters affecting adsorption behaviors such as pH, contact time, and initial concentration and the photocatalytic degradation of MB were systematically investigated. The result showed that BG-La had excellent removal rate (R of MB, and BG-La showed better photocatalytic effect than undoped mesoporous bioactive glass (BG. Furthermore, the MB loaded BG-La was easily desorbed with acid solution due to its electronegativity and mesoporous structure. The result indicated that these materials can be employed as candidates for removal of dye pollutant owing to their high removal rate, excellent photocatalytic effect, desorption performance, and their reusability.

Complex sulphide-barite ore leaching in ferric chloride solution

Directory of Open Access Journals (Sweden)

Miroslav Sokić

2016-06-01

Full Text Available The results of research on the leaching process of complex sulphide-barite ore were presented in this paper. The leaching process was carried out in a laboratory autoclave by ferric chloride solution. Considering that those minerals are represented in complex structural-textural relationships, it is not possible to extract lead, zinc and copper minerals from ore by flotation methods. The obtained results confirmed possibility of the ore processing directly, by chemical methods. The effect of temperature, time and oxygen partial pressure on the lead, zinc and copper dissolution was studied. The maximal leaching degree was achieved at 100 °C and amount of 91.5 % for Pb, 96.1 % for Zn and 60.7 % for Cu. Leaching at temperatures above 100 °C is impractical.

Preparation and characterization of intrinsically coloured polymers using high energy radiation induced processes

International Nuclear Information System (INIS)

Guthrie, J.T.

1978-07-01

Information on the development in research is given in the utilization of high energy radiation sources in polymerizations and on polymer characterization in the following three areas: studies on the nitrile-styrene system, studies on the radiation induced polymerization of 2-vinyl anthraquinone and the graft polymerization of vinyl monomers onto cellulose in the DMSO/HCHO/cellulose system. Within the framework of research in radiation induced polymerization, samples of 2-vinyl anthraquinone were subjected to X-ray diffraction and e.s.r. examinations and the kinetics and mechanism of γ-ray induced solution polymerization of 2-vinyl anthraquinone in methylene chloride and dimethyl sulfoxide was investigated. Methylene chloride was found to be an efficient solvent for poly(2-vinyl anthraquinone). The rate of polymerization in methylene chloride was 10 3 times greater than that obtained using dimethyl sulfoxide as solvent

21 CFR 184.1138 - Ammonium chloride.

Science.gov (United States)

2010-04-01

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

21 CFR 184.1426 - Magnesium chloride.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Magnesium chloride. 184.1426 Section 184.1426 Food... Specific Substances Affirmed as GRAS § 184.1426 Magnesium chloride. (a) Magnesium chloride (MgC12·6H2O, CAS... hydrochloric acid solution and crystallizing out magnesium chloride hexahydrate. (b) The ingredient meets the...

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

International Nuclear Information System (INIS)

Midgley, D.; Gatford, C.

1989-11-01

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)

Surface protection of mild steel in acidic chloride solution by 5-Nitro-8-Hydroxy Quinoline

Directory of Open Access Journals (Sweden)

R. Ganapathi Sundaram

2018-03-01

Full Text Available The effect of commercially available quinoline nucleus based pharmaceutically active compound 5-Nitro-8-Hydroxy Quinoline (NHQ against the corrosion of mild steel (MS in 1 M acidic chloride (HCl solution was investigated by chemical (weight loss – WL and electrochemical (Tafel polarization, Linear polarization and Electrochemical impedance spectroscopy techniques. From all the four methods, it is inferred that the percentage of inhibition efficiency increases with increasing the inhibitor concentration from 50 to 300 ppm. The adsorption behavior of inhibitor obeyed through Langmuir isotherm model. Thermodynamic parameters were also calculated and predict that the process of inhibition is a spontaneous reaction. EIS technique exhibits one capacitive loop indicating that, the corrosion reaction is controlled by charge transfer process. Tafel polarization studies revealed that the investigated inhibitor is mixed type and the mode of adsorption is physical in nature. The surface morphologies were examined by FT-IR, SEM and EDX techniques. Theoretical quantum chemical calculations were performed to confirm the ability of NHQ to adsorb onto mild steel surface. Keywords: Acidic chloride solution, MS, NHQ, WL, SEM, FT-IR

Corrosion cracking of 03N18K1M3TYu and 02N12Kh5M3 maraging steels in chloride solutions

Energy Technology Data Exchange (ETDEWEB)

Pavlov, V.N.; Chumalo, G.V.; Vereshchagin, A.N.; Melekhov, R.K.

1987-07-01

The authors investigate the electrochemical behavior in 0.5% NaCl solution and 42% MgCl/sub 2/ solution and the tendency toward corrosion cracking was determined in boiling 0.5% chloride solution of the cobalt-containing maraging steels in the title. Weld specimens and specimens of the base metal of 03N18K1M3TYu steel were tested in 3% NaCl solution for resistance to corrosion cracking. Additional investigations were made of specimens of that steel with previously created fatigue cracks of the base metal and the weld specimens in 3% NaCl solutions, since that steel is a promising material for structures operating in sea water and low concentration chloride solutions.

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

International Nuclear Information System (INIS)

Ho, J.-T.; Yu, G.-P.

2004-01-01

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)

The effect of borate and phosphate inhibitors on corrosion rate material SS321 and incoloy 800 in chloride containing solution by using potentiodynamic method

International Nuclear Information System (INIS)

Febriyanto; Sriyono; Satmoko, Ari

1998-01-01

Determination of corrosion rate of steam generator materials (SS 321 and incoloy 800) in chloride containing solution using potentiodynamic method from CMS 100. NaCl 1%, 3% and 5% solution using is used as tested solution. A tested material is grounded by grinding paper on grade 400 600, 800 and 1000, then polished by METADI 1/4 microns paste to get homogeneity. Furthermore, the tested materials is mounted by epoxide resin, so only the surface which contacts to tested solution is open. From the result obtained that borate and phosphate inhibitor can reduce corrosion rate and aggressiveness of chloride ion

Study of the transport characteristics of uranyl chloride in a highly concentrated aqueous solution of sodium chloride

International Nuclear Information System (INIS)

Murso, H.

1986-01-01

The purpose of this work was the study of the transport processes of uranyl chloride at various temperatures, in order to be able to estimate the danger potential of the intrusion of water during storage in salt form. For this the concentration dependency of the approximated principal diffusion coefficients of uranyl chloride in a table salt solution, which with a c(NaCl) = 5.2 mol/l is almost at the saturation point, was studied at 25, 40 and 50degC. The measurements were successful in the ternarian system UO 2 Cl 2 -NaCl-H 2 O with absorption optics. An unexpected temperature dependency of the diffusion coefficients was found, which reached its minimum at 40degC with UO 2 Cl 2 concentrations of less than 2x10 -2 mol/l. For comparison the diffusion coefficients were measured in the binary system UO 2 Cl 2 -H 2 O and compared with theoretical calculations. The cause for the poor correlation found here is thought to be the hydrolysis products, whose formation is strongly influenced by the foreign-electrolyte concentration (NaCl). For clarification, viscosity measurements and molar mass determinations (ultracentrifuge) will be done. Some pH-dependent hydrolysis equilibriums are being postulated and the equilibrium constants of uranyl hydroxo complexes are being determined by sedimentation analysis. (orig./RB) [de

Removal of Congo Red and Methylene Blue from Aqueous Solutions by Vermicompost-Derived Biochars

Science.gov (United States)

Yang, Gang; Wu, Lin; Xian, Qiming; Shen, Fei; Wu, Jun; Zhang, Yanzong

2016-01-01

Biochars, produced by pyrolyzing vermicompost at 300, 500, and 700°C were characterized and their ability to adsorb the dyes Congo red (CR) and Methylene blue (MB) in an aqueous solution was investigated. The physical and chemical properties of biochars varied significantly based on the pyrolysis temperatures. Analysis of the data revealed that the aromaticity, polarity, specific surface area, pH, and ash content of the biochars increased gradually with the increase in pyrolysis temperature, while the cation exchange capacity, and carbon, hydrogen, nitrogen and oxygen contents decreased. The adsorption kinetics of CR and MB were described by pseudo-second-order kinetic models. Both of Langmuir and Temkin model could be employed to describe the adsorption behaviors of CR and MB by these biochars. The biochars generated at higher pyrolysis temperature displayed higher CR adsorption capacities and lower MB adsorption capacities than those compared with the biochars generated at lower pyrolysis temperatures. The biochar generated at the higher pyrolytic temperature displayed the higher ability to adsorb CR owing to its promoted aromaticity, and the cation exchange is the key factor that positively affects adsorption of MB. PMID:27144922

Standardization of NaI gamma spectrometer using a newly developed standard for the estimation of 228Ra in rare earth chloride solution

International Nuclear Information System (INIS)

Sahu, A.; Patra, R.P.; Jha, S.K.; Tripathi, R.M.; Patro, P.

2018-01-01

Monazite is a naturally occurring mineral which is a phosphate of various rare earths and thorium with traces of uranium. Indian Rare Earths Limited has set up a Monazite Processing Plant (MoPP) at Orissa Sand Complex (OSCOM), Odisha for recovery of various elements from Monazite. The finely ground monazite is processed with hot NaOH to separate the phosphate component as Tri-Sodium Phosphate from the mixed hydroxide. Then the mixed hydroxide is treated with HCl at controlled pH to separate rare earth as rare earth chloride solution. The rare earth chloride solution also contains 228 Ra which is generated in the 232 Th decay series. The rare earth chloride solution is then treated with BaCl 2 , MgSO 4 and Na 2 S; 228 Ra gets co-precipitated with Ba as Lead-Barium Sulfate. To meet the regulatory requirement, 228 Ra activity is reduced to below 1 Bq/g limit

Pitting morphologies of zirconium base alloys in aqueous and non aqueous chloride media

International Nuclear Information System (INIS)

Palit, G.C.; Gadiyar, H.S.

1988-01-01

Pitting morphology of zirconium and Zr-Cr alloys in aqueous chloride and nonaqueous methanol + 0.4 per cent HCl solution was investigated and observed to follow different modes in these two environments. While in aqueous chloride solution pitting was transgranular and randomly oriented, in methanol-chloride solution pits were observed to initiate and propagate along the grain boundaries. In aqueous chloride solution very irregular and sponge like zirconium metal was formed inside the pit while in methanol-chloride solution the pits were crystallographic in nature. Optical microscopy has revealed that pits preferentially initiate and propagate along scratch line in aqueous chloride solution, but such was not the case in nonaqueous methanol-chloride solution. The nature and the mechanism operating in the catastropic failure of these materials are investigated. (author). 10 refs., 11 figs

EXTRACTION CHARACTERISTICS OF THE CATION OF ALKYLDIMETHYLBENZYLAMMONIUM CHLORIDE AT THE PHASE BOUNDARY WATER-MEMBRANE SOLVENT

Directory of Open Access Journals (Sweden)

O. V. Luganska

2015-06-01

Full Text Available The extraction coefficients of the cation of alkyldimethylbenzylammonium chloride at the phase boundary water-tricresylphosphate, water-dioctylphthalate, water-dibutylphtalate have been determined by the potentiometric titration of the aqueous phase with a silver electrode. The correctness of the obtained results has been proved by the titrimetric method with visual fixation of the equivalence point using methylene blue indicator.

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

International Nuclear Information System (INIS)

Freire, L.; Carmezim, M.J.; Ferreira, M.G.S.; Montemor, M.F.

2011-01-01

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.

Separation of Ce and La from Synthetic Chloride Leach Solution of Monazite Sand by Precipitation and Solvent Extraction

Science.gov (United States)

Banda, Raju; Jeon, Ho Seok; Lee, Man Seung

2014-12-01

Precipitation and solvent extraction experiments have been performed to recover light rare earths from simulated monazite sand chloride leach solutions. Precipitation conditions were obtained to recover Ce by adding NaClO as an oxidant. Among some cationic extractants (PC 88A, D2EHPA, Cyanex 272, LIX 63), PC 88A showed the best performance to separate La from the resulting chloride solution. Furthermore, the mixture of PC 88A with other solvating (TBP, TOPO) and amine extractants (Alamine 336, Aliquat 336) was tested to increase the separation factor of La from Pr and Nd. The use of mixed extractants greatly enhanced the separation of La from the two other metals. McCabe-Thiele diagrams for the extraction of Pr and Nd with the PC 88A/Alamine 336 mixture were constructed.

Chloride removal from vitrification offgas

Energy Technology Data Exchange (ETDEWEB)

Slaathaug, E.J. [Westinghouse Hanford Co., Richland, WA (United States)

1995-06-01

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.

Chloride removal from vitrification offgas

International Nuclear Information System (INIS)

Slaathaug, E.J.

1995-01-01

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

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

International Nuclear Information System (INIS)

Nirdosh, I.; Lakhani, S.; Yunus, M.Z.M.

1993-01-01

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, FeS 2 , 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)

Cr(OH)3-NPs-CNC hybrid nanocomposite: a sorbent for adsorptive removal of methylene blue and malachite green from solutions.

Science.gov (United States)

Nekouei, Farzin; Nekouei, Shahram; Keshtpour, Farzaneh; Noorizadeh, Hossein; Wang, Shaobin

2017-11-01

In this article, Cr(OH) 3 nanoparticle-modified cellulose nanocrystal (CNC) as a novel hybrid nanocomposite (Cr(OH) 3 -NPs-CNC) was prepared by a simple procedure and used as a sorbent for adsorptive removal of methylene blue (MB) and malachite green (MG) from aqueous solution. Different kinetic models were tested, and the pseudo-second-order kinetic model was found more suitable for the MB and MG adsorption processes. The BET and Langmuir models were more suitable for the adsorption processes of MB and MG. Thermodynamic studies suggested that the adsorption of MB and MG onto Cr(OH) 3 -NPs-CNC nanocomposite was a spontaneous and endothermic process. The maximum adsorption capacities for MB and MG were reached 106 and 104 mg/g, respectively, which were almost two times higher than unmodified CNC. The chemical stability and leaching tests of the Cr(OH) 3 -NPs-CNC hybrid nanocomposite showed that only small amounts of chromium were leached into the solution.

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

Science.gov (United States)

Ai, Zhiyong; Sun, Wei; Jiang, Jinyang; Song, Dan; Ma, Han; Zhang, Jianchun; Wang, Danqian

2016-09-01

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

Effect of chloride ions on the corrosion behavior of low-alloy steel containing copper and antimony in sulfuric acid solution

Science.gov (United States)

Park, Sun-Ah; Kim, Seon-Hong; Yoo, Yun-Ha; Kim, Jung-Gu

2015-05-01

The influence of the addition of HCl on the corrosion behavior of low-alloy steel containing copper and antimony was investigated using electrochemical (potentiodynamic and potentiostatic polarization tests, and electrochemical impedance spectroscopy) and weight loss tests in a 1.6M H2SO4 solution with different concentrations of hydrochloric acid (0.00, 0.08, 0.15 and 0.20 M HCl) at 60 °C. The result showed that the corrosion rate decreased with increasing HCl by the formation of protective layers. SEM, EDS and XPS examinations of the corroded surfaces after the immersion test indicated that the corrosion production layer formed in the solution containing HCl was highly comprised of metallic Cu, Cu chloride and metallic (Fe, Cu, Sb) compounds. The corrosion resistance was improved by the Cu-enriched layer, in which chloride ions are an accelerator for cupric ion reduction during copper deposition. Furthermore, cuprous and antimonious chloride species are complex salts for cuprous ions adsorbed on the surface during copper deposition.

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.

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 - others: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

Effect of Sulfide Concentration on Copper Corrosion in Anoxic Chloride-Containing Solutions

Science.gov (United States)

Kong, Decheng; Dong, Chaofang; Xu, Aoni; Man, Cheng; He, Chang; Li, Xiaogang

2017-04-01

The structure and property of passive film on copper are strongly dependent on the sulfide concentration; based on this, a series of electrochemical methods were applied to investigate the effect of sulfide concentration on copper corrosion in anaerobic chloride-containing solutions. The cyclic voltammetry and x-ray photoelectron spectroscopy analysis demonstrated that the corrosion products formed on copper in anaerobic sulfide solutions comprise Cu2S and CuS. And the corrosion resistance of copper decreased with increasing sulfide concentration and faster sulfide addition, owing to the various structures of the passive films observed by the atomic force microscope and scanning electron microscope. A p-type semiconductor character was obtained under all experimental conditions, and the defect concentration, which had a magnitude of 1022-1023 cm-3, increased with increasing sulfide concentration, resulting in a higher rate of both film growth and dissolution.

Products of the reaction between methylene iodide and tertiary arsines

International Nuclear Information System (INIS)

Gigauri, R.D.; Arabuli, L.G.; Machaidze, Z.I.; Rusiya, M.Sh.

2005-01-01

Iodides of iodomethylenetrialkyl(aryl) arsonium were synthesized with high yields as a result of interaction between methylene iodide and tertiary arsines. Exchange reactions of the iodides prepared with lead(II) nitrate in water-alcohol solutions gave rise to formation of iodomethylenetrialkyl(aryl) arsonium nitrates. All the products prepared were characterized by data of elementary analysis, IR spectroscopy, conductometry and melting points measurements [ru

POLY[3-(METHACRYLOYLAMINO)PROPYL]TRIMETHYLAMMONIUM CHLORIDE HYDROGEL. SYNTHESIS AND WATER-ABSORPTION CAPACITY.

OpenAIRE

Rivas, Bernabé L.; Canessa, Guido S.; Martínez, Esteban

2000-01-01

The radical polymerization of [3-(methacryloylamino)propyl]trimethylammonium chloride by using ammonium persulfate as initiator and N,N-methylene-bis-acrylamide as crosslinker reagent was carried out. The polymers were completely insoluble in water and characterized by FT IR spectroscopy and thermal analysis. The effect of the crosslinker reagent on the water sorption capacity was investigated. The highest water-absorption (46.6 g of water/ g of xerogel) was observed with the lowest mol% of c...

Thermochemistry of certain rare earth and ammonium double chlorides

International Nuclear Information System (INIS)

Usubaliev, D.U.; Abramtsev, V.A.; Kydynov, M.K.; Vilyaev, A.N.

1987-01-01

In a calorimeter with isothermal casing at 25 deg C dissolution enthalpies of double chlorides of rare earths and ammonium LnCl 3 x2NH 4 Cl (Ln=La, Sm) and LnCl 3 x3NH 4 Cl (Ln=Gd, Tb, Ho) in water, as well as dissolution enthalpy of rare earth chlorides in solution of ammonium chloride and NH 4 Cl in solution of rare earth chloride, have been measured. Formation enthalpies, standard formation enthalpies, dissociation enthalpies of the above-mentioned double chlorides are calculated

Corrosion of alloy 22 in phosphate and chloride containing solutions

International Nuclear Information System (INIS)

Carranza, Ricardo M.

2007-01-01

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 -3 M 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/cm 2 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)

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.

Removal of methylene blue from aqueous solution with magnetite loaded multi-wall carbon nanotube: Kinetic, isotherm and mechanism analysis

International Nuclear Information System (INIS)

Ai, Lunhong; Zhang, Chunying; Liao, Fang; Wang, Yao; Li, Ming; Meng, Lanying; Jiang, Jing

2011-01-01

Highlights: ► M-MWCNTs were synthesized by a facile one-pot solvothermal method and used as an efficient adsorbent for removing toxic dye from aqueous solution. ► The adsorption process was characterized by kinetics and isotherm analysis. ► FTIR analysis was employed to investigate the interactions between M-MWCNTs and dye. - Abstract: In this study, we have demonstrated the efficient removal of cationic dye, methylene blue (MB), from aqueous solution with the one-pot solvothermal synthesized magnetite-loaded multi-walled carbon nanotubes (M-MWCNTs). The as-prepared M-MWCNTs were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) spectroscopy. The effects of contact time, initial dye concentration, and solution pH on the adsorption of MB onto M-MWCNTs were systematically studied. It was shown that the MB adsorption was pH-dependent. Adsorption kinetics was best described by the pseudo-second-order model. Equilibrium data were well fitted to the Langmuir isotherm model, yielding maximum monolayer adsorption capacity of 48.06 mg g −1 . FTIR analysis suggested that the adsorption mechanism was possibly attributed to the electrostatic attraction and π–π stacking interactions between MWCNTs and MB.

Effect of cation nature of Cl2- yields in pulse radiolysis of alkali metal chloride aqueous solutions

International Nuclear Information System (INIS)

Kabakchi, S.A.; Zansokhova, A.A.; Pikaev, A.K.

1975-01-01

A study is made of the amount of Cl 2 - formed during a pulsating radiolysis of potassium, rubidium and cesium chlorides in aqueous solutions saturated with air. An equation is presented relating the yield of Cl 2 - and the concentration of the starting materials. Various mechanisms describing the radiolysis of neutral aqueous solutions of the chlorides are proposed. The observed effect of the cation on the efficiency of Cl 2 - formations favours the mechanism according to which Cl 2 - forms through the reaction of Cl - ion with a ''hole''. Due to charge migration in the conductivity zone the electron transfer reaction either goes steadily by jumps. As a result of the interaction between the ''hole'' and water [H 3 O + ...OH] a complex is formed from a hydrogen ion and OH radical, which are united trhough the hydrogen bond. Disturbance of the hydrogen bond structure should increase the probability of disintegration of the complex

Synergistic effect of pulsed corona discharges and ozonation on decolourization of methylene blue in water

CERN Document Server

Malik, M A; Ghaffar, A; Ahmed, K

2002-01-01

The effect of O sub 2 and O sub 3 bubbling on decolourization of methylene blue by pulsed corona discharges in water was studied. The pulsed corona discharges were produced by charging an 80 pF capacitor with a 40 kV DC source, through a 100 M OMEGA resistor, and discharging it into a needle-plate type reactor at 60 Hz through a rotating spark gap switch. A 20 ml sample of 13.25 mg l sup - sup 1 methylene blue in distilled water was decolourized in 120 min. Bubbling O sub 2 at 10 ml min sup - sup 1 through the discharge region reduced the decolourization time to 25 min. Bubbling O sub 2 containing 1500 mu mol O sub 3 l sup - sup 1 at 10 ml min sup - sup 1 reduced the decolourization time to 8 min. The O sub 3 was produced by fractionating input energy between a water treatment reactor and a O sub 3 generator, i.e. no additional energy was consumed for O sub 3 production. Under the same experimental conditions methylene blue solution in tap water was decolourized in >210 min by corona discharge in solution, in...

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.

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.

Reactive oxygen species generation in aqueous solutions containing GdVO4:Eu3+ nanoparticles and their complexes with methylene blue

Science.gov (United States)

Hubenko, Kateryna; Yefimova, Svetlana; Tkacheva, Tatyana; Maksimchuk, Pavel; Borovoy, Igor; Klochkov, Vladimir; Kavok, Nataliya; Opolonin, Oleksander; Malyukin, Yuri

2018-04-01

It this letter, we report the study of free radicals and reactive oxygen species (ROS) generation in water solutions containing gadolinium orthovanadate GdVO4:Eu3+ nanoparticles (VNPs) and their complexes with methylene blue (MB) photosensitizer. The catalytic activity was studied under UV-Vis and X-ray irradiation by three methods (conjugated dienes test, OH· radical, and singlet oxygen detection). It has been shown that the VNPs-MB complexes reveal high efficiency of ROS generation under UV-Vis irradiation associated with both high efficiency of OH· radicals generation by VNPs and singlet oxygen generation by MB due to nonradiative excitation energy transfer from VNPs to MB molecules. Contrary to that under X-ray irradiation, the strong OH . radicals scavenging by VNPs has been observed.

Separation of Pr and Nd from La in chloride solution by extraction with a mixture of Cyanex 272 and Alamine 336

Science.gov (United States)

Liu, Yang; Jeon, Ho Seok; Lee, Man Seung

2015-09-01

The possibility of separation of Pr and Nd from La in a chloride leaching solution of monazite sand has been investigated by using a binary mixture of Cyanex 272 (bis(2,4,4-trimethylpentyl) phosphinic acid) and Alamine 336 (tri-octyl/decyl amine). The binary mixture showed synergism on the extraction of the three metals and led to an increase in the separation factor between Pr/Nd and La compared to Cyanex 272 alone. Although the addition of chloride ion into aqueous increased the extraction of the metals, this addition had negative effect on the separation of Nd/Pr and La. McCabe-Thiele diagrams for the extraction of Pr and Nd with the binary mixture were constructed. Stripping of metals from the loaded organic phase was achieved with 0.7 M HCl. The difference in the solvent extraction of the rare earth elements from chloride solution between the binary mixture and saponified extractants was also discussed.

Effect of temperature on the partial molar volume, isentropic compressibility and viscosity of DL-2-aminobutyric acid in water and in aqueous sodium chloride solutions

International Nuclear Information System (INIS)

Romero, Carmen M.; Rodríguez, Diana M.; Ribeiro, Ana C.F.; Esteso, Miguel A.

2017-01-01

Highlights: • Apparent volumes, apparent compressibilities, viscosities of DL-2-aminobutyric acid. • Effect of temperature on the values for these properties. • Hydrophobic and hydrophilic interactions and the effect of sodium chloride. - Abstract: Density, sound velocity and viscosity of DL-2-aminobutyric acid in water and in aqueous sodium chloride solutions have been measured at temperatures of (293.15, 298.15, 303.15, 308.15 and 313.15) K. The experimental results were used to determine the apparent molar volume and the apparent molar compressibility as a function of composition at these temperatures. The limiting values of both the partial molar volume and the partial molar adiabatic compressibility at infinite dilution of DL-2-aminobutyric acid in water and in aqueous sodium chloride solutions were determined at each temperature. The experimental viscosity values were adjusted by a least-squares method to a second order equation as proposed by Tsangaris-Martin to obtain the viscosity B coefficient which depends on the size, shape and charge of the solute molecule. The influence of the temperature on the behaviour of the selected properties is discussed in terms of both the solute hydration and the balance between hydrophobic and hydrophilic interactions between the acids and water, and the effect of the sodium chloride concentration.

Studies on Biosorption of Methylene Blue from Aqueous Solutions by Powdered Palm Tree Flower (Borassus flabellifer

Directory of Open Access Journals (Sweden)

M. Srinivas Kini

2014-01-01

Full Text Available Biosorption experiments were carried out for the removal of methylene blue (MB using palm tree male flower (PTMF as the biosorbent at various pH, temperature, biosorbent, and adsorbate concentration. The optimum pH was found to be 6.0. The kinetic data were fitted in pseudofirst-order and second-order models. The equilibrium data were well-fitted in Langmuir isotherm and the maximum equilibrium capacities of the biosorbent were found to be 143.6, 153,9, 157.3 mg/g at 303, 313, and 323 K, respectively. Thermodynamic data for the adsorption system indicated spontaneous and endothermic process. The enthalpy and entropy values for adsorption were obtained as 15.06 KJ/mol and 0.129 KJ/mol K, respectively, in the temperature range of 303–323 K. A mathematical model for MB transported by molecular diffusion from the bulk of the solution to the surface of PTMF was derived and the values of liquid phase diffusivity and external mass transfer coefficient were estimated.

Compound list: methylene dianiline [Open TG-GATEs

Lifescience Database Archive (English)

Full Text Available methylene dianiline DAPM 00155 ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Human/in_vitro/methyle...es/LATEST/Rat/in_vivo/Liver/Single/methylene_dianiline.Rat.in_vivo.Liver.Single.zip ftp://ftp.biosciencedbc....jp/archive/open-tggates/LATEST/Rat/in_vivo/Liver/Repeat/methylene_dianiline.Rat.in_vivo.Liver.Repeat.zip ... ...ne_dianiline.Human.in_vitro.Liver.zip ftp://ftp.biosciencedbc.jp/archive/open-tggat

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

International Nuclear Information System (INIS)

Carranza, Ricardo M.

2009-01-01

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/cm 2 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

Effect of radioactive chromate on the corrosion and polarisation of mild steel in sodium chloride solution

International Nuclear Information System (INIS)

Subramanyan, N.; Ramakrishnaiah, K.; Iyer, S.V.; Kapali, V.

1980-01-01

Corrosion tests of mild steel in 0.01% sodium chloride containing radioactive chromate and non-radioactive chromate have been carried out. It has been observed that the labelled sodium chromate has a deleterious effect on the inhibitive action of non-radioactive chromate. The effect of radioactive chromate on the potentiostatic polarization of m.s. in sodium chloride solution containing non-radioactive sodium chromate has also been studied. It is observed that both the cathodic and the anodic polarisation of the metal is diminished in the presence of radioactive chromate. The behaviour of the system in the presence of radioactive chromate is attributed both to the action of depolarisers produced by radiolysis of water and to the effect of gamma radiation on the metal. (author)

The use of chemical modified chitosan with succinic anhydride in the methylene blue adsorption; O emprego de quitosana quimicamente modificada com anidrido succinico na adsorcao de azul de metileno

Energy Technology Data Exchange (ETDEWEB)

Lima, Ilauro S.; Ribeiro, Emerson S.; Airoldi, Claudio [Universidade Estadual de Campinas, SP (Brazil). Inst. de Quimica]. E-mail: airoldi@iqm.unicamp.br

2006-05-15

The adsorption capacity of a-chitosan and its modified form with succinic anhydride was compared with the traditional adsorbent active carbon by using the dye methylene blue, employed in the textile industry. The isotherms for both biopolymers were classified as SSA systems in the Giles model, more specifically iclass and subgroup 3. The dye concentration in the supernatant in the adsorption assay was determined through electronic spectroscopy. By calorimetric titration thermodynamic data of the interaction between methylene blue and the chemically modified chitosan at the solid/liquid interface were obtained. The enthalpy of the dye/chitosan interaction gave 2.47 {+-} 0.02 kJ mol-1 with an equilibrium constant of 7350 {+-} 10 and for the carbon/dye interaction this constant gave 5951 {+-} 8. The spontaneity of these adsorptions are reflected by the free Gibbs energies of -22.1 {+-} 0.4 and -21.5 {+-} 0.2 kJ mol-1, respectively, found for these systems. This new adsorbent derived from a natural polysaccharide is as efficient as activated carbon. However 97% of the bonded dye can be eluted by sodium chloride solution, while this same operation elutes only 42% from carbon. Chitosan is efficient in dye removal with the additional advantage of being cheap, non-toxic, biocompatible and biodegradable. (author)

Sorption study of methylene blue on activated carbon prepared from Jatropha curcas and Terminalia catappa seed coats

Directory of Open Access Journals (Sweden)

Ismaila Olalekan Saheed

2016-12-01

Full Text Available This research work targets the effectiveness of the prepared activated carbon from Jatropha curcas and Terminalia catappa seed coats for the sorption of methylene blue (MB from aqueous solution. The prepared Jatropha activated carbon (JAC and Terminalia activated carbon (TAC were characterised using Fourier transform infrared spectroscopy (FTIR, Scanning electron microscopy (SEM and Branauer- Emmett-Teller (BET surface area analysis. Effect of initial concentration, pH, contact time, adsorbent dose and temperature on the sorption experiments were studied and the adsorption capacity of these adsorbents were found to be 37.84 mg/g and 17.44 mg/g for methylene blue uptake by JAC and TAC respectively. The experimental data were analysed using Langmuir, Fruendlich, and Dubinin-Radushkevich isotherms. The data fitted best into Langmuir isotherm for Methylene blue-JAC and Methylene blue-TAC systems. The kinetic studies fitted into pseudo second order kinetics model. The process chemistry was exothermic.

Catalytic destruction of perchlorate in ferric chloride and hydrochloric acid solution with control of temperature, pressure and chemical reagents

Science.gov (United States)

Gu, Baohua; Cole, David R.; Brown, Gilbert M.

2004-10-05

A method is described to decompose perchlorate in a FeCl.sub.3 /HCl aqueous solution such as would be used to regenerate an anion exchange resin used to remove perchlorate. The solution is mixed with a reducing agent, preferably an organic alcohol and/or ferrous chloride, and can be heated to accelerate the decomposition of perchlorate. Lower temperatures may be employed if a catalyst is added.

Effective photocatalytic decolorization of methylene blue utilizing ZnO/rectorite nanocomposite under simulated solar irradiation

Energy Technology Data Exchange (ETDEWEB)

Li, Shi-qian, E-mail: shiqianli04@tom.com [College of Resource and Environmental Science, Wuhan University, Hubei Key Laboratory of Biomass-resource Chemical and Environment Bio-technology, Wuhan 430079 (China); Department of Biology and Chemical Engineering, FuQing Branch of Fujian Normal University, Fuqing 350300 (China); Zhou, Pei-jiang; Zhang, Wan-shun [College of Resource and Environmental Science, Wuhan University, Hubei Key Laboratory of Biomass-resource Chemical and Environment Bio-technology, Wuhan 430079 (China); Chen, Sheng [Department of Biology and Chemical Engineering, FuQing Branch of Fujian Normal University, Fuqing 350300 (China); Peng, Hong [State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Hubei, Wuhan 430072 (China)

2014-12-15

Highlights: • Preparation of ZnO inserted in rectorite as photocatalyst in methylene blue photodegradation. • The ZnO/rectorite can be used as adsorbents and photocatalysts. • The ZnO/rectorite system was easy to be gathered and recycled. • Inferred ZnO/rectorite the photocatalytic degradation methylene blue of aqueous micro mechanism. - Abstract: Preparation of a nanometer zinc oxide/rectorite (ZnO/REC) composites photocatalyst based on natural rectorite was conducted using a hydrothermal intercalation method. The structure, thermal property, and surface morphology of ZnO/REC were characterized by X-ray diffractor (XRD), thermogravimetric analysis (TGA), high-resolution transmission electron microscope (HRTEM) and scanning electron microscope (SEM) techniques. The photocatalytic activity of ZnO/REC was evaluated by photocatalytic decolorization of methylene blue (MB) in aqueous solution as a model pollutant under simulated sunlight irradiation. The HRTEM results revealed that well-dispersed and uniform ZnO/REC nanocomposites with diameters of 10 nm were embedded in rectorite. The ZnO/REC nanocomposite exhibited high photocatalytic activity under simulated solar irradiation. After 2 h of irradiation by simulated solar light, over 99% of methylene blue solution (15 mg/L) was decolorized with 0.9 g/L of the photocatalyst. The ZnO/REC was reusable, which meant that the adsorption photocatalytic decolorization process could be operated at a relatively low cost. Since this process does not require the addition of hydrogen peroxide but uses sunlight, it can be developed as an economically feasible and environmentally friendly method to decolorize or treat dye wastewater using solar.

Photocatalytic degradation of methylene blue by C 3 N 4 /ZnO

Indian Academy of Sciences (India)

The photocatalytic activities of prepared samples were investigated under the illumination of blacklight and fluorescent lamps as the low wattage light source. The C 3 N 4 /ZnO showed a better photocatalytic activity than ZnO to degrade a methylene blue (MB) dye solution using blacklight lamps, but there is no significant ...

Anodic dissolution and corrosion of alloy Cu30Ni in chloride solutions

International Nuclear Information System (INIS)

Zolotarev, E.I.

1989-01-01

The anodic and corrosion behavior of alloy Cu30Ni is studied in a solution of 3 N NaCl + 0.01 N HCl by a radiometric method using gamma isotopes of 58 Co (as a marker for Ni) and 64 Cu in combination with electrochemical measurements. It was established that under stationary conditions there was uniform dissolution of the alloy both during free corrosion and anodic polarization. The authors obtained partial anodic dissolution curves for the components of the alloy. It was shown that the dissolution kinetics differed from the mechanisms controlling dissolution of the corresponding pure metals. During corrosion of the alloy in an oxygen atmosphere a back precipitation of copper on the surface of the alloy was not observed. The characteristics observed in the corrosion-electrochemical behavior of the alloy in concentrated chloride solutions can be explained by the presence of Ni on the surface of the dissolving alloy

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

Science.gov (United States)

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

2018-03-17

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

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. ...

A spectroscopic study of uranyl speciation in chloride-bearing solutions at temperatures up to 250 °C

Science.gov (United States)

Migdisov, A. A.; Boukhalfa, H.; Timofeev, A.; Runde, W.; Roback, R.; Williams-Jones, A. E.

2018-02-01

The speciation of U in NaCl-bearing solutions at temperatures up to 250 °C and concentrations of NaCl up to 1.5 m has been investigated using an in situ spectroscopic technique. The recorded spectra permit us to identify the species present in the solutions as UO22+, UO2Cl+, and UO2Cl2°. UO2Cl3- is also likely present at high temperatures and NaCl concentrations, but concentrations of this species are insufficient for derivation of the formation constants. No evidence was found for species of higher ligand (Cl-) number. Thermodynamic stability constants derived for these species show fair agreement with published data for 25 °C, but differ significantly from those predicted by an earlier high-temperature study (Dargent et al., 2013), which suggested that UO2Cl42- and UO2Cl53- contribute significantly to the mass balance of uranyl chloride complexes, especially at high temperature. In contrast, our data suggest that the main uranyl-chloride complex present in aqueous solutions at T > 150 °C and concentrations of NaCl relevant to natural hydrothermal systems is UO2Cl2°. The values of the logarithms of thermodynamic formation constants (β) for the reaction UO22+ + Cl- = UO2Cl+ are 0.02, 0.25, 0.55, 1.09, 1.59, and 2.28 derived at 25, 50, 100, 150, 200, and 250 °C, respectively. For the reaction UO22+ + 2Cl- = UO2Cl2° the values of log β derived at these temperatures are 0.4, 0.58, 0.74, 1.44, 2.18, and 3.42. Values of the formation constant estimated for uranyl-chloride species predict the high concentrations of U observed by Richard et al. (2011) in fluid inclusions of the giant McArthur River unconformity-type uranium deposit.

Synergistic effect of pulsed corona discharges and ozonation on decolourization of methylene blue in water

International Nuclear Information System (INIS)

Malik, Muhammad Arif; Ubaid-ur-Rehman; Ghaffar, Abdul; Ahmed, Kurshid

2002-01-01

The effect of O 2 and O 3 bubbling on decolourization of methylene blue by pulsed corona discharges in water was studied. The pulsed corona discharges were produced by charging an 80 pF capacitor with a 40 kV DC source, through a 100 MΩ resistor, and discharging it into a needle-plate type reactor at 60 Hz through a rotating spark gap switch. A 20 ml sample of 13.25 mg l -1 methylene blue in distilled water was decolourized in 120 min. Bubbling O 2 at 10 ml min -1 through the discharge region reduced the decolourization time to 25 min. Bubbling O 2 containing 1500 μmol O 3 l -1 at 10 ml min -1 reduced the decolourization time to 8 min. The O 3 was produced by fractionating input energy between a water treatment reactor and a O 3 generator, i.e. no additional energy was consumed for O 3 production. Under the same experimental conditions methylene blue solution in tap water was decolourized in >210 min by corona discharge in solution, in 30 min by corona discharge with O 2 bubbling, and in 11 min by corona discharge with bubbling of O 2 containing 1500 μmol O 3 l -1

Adsorption capacity of methylene blue, an organic pollutant, by montmorillonite clay

KAUST Repository

Feddal, I.; Ramdani, Amina; Taleb, Safia; Gaigneaux, E. M.; Batis, Narjè s Harrouch; Ghaffour, NorEddine

2013-01-01

The isotherms and kinetics of the adsorption of a cationic dye in aqueous solution, methylene blue, on a local Algerian montmorillonite clay mineral (raw, sodium and thermally activated at 300 and 500°C) were determined experimentally. Various parameters influencing the adsorption were optimized, mainly solid-liquid contact time, mass of adsorbent, initial concentration of dye, pH of the solution and temperature. Results showed that the adsorption kinetics were fast: 30 min for the raw clay mineral, and 20 min for sodium clay mineral (SC) and thermally activated at 300°C, whereas with the clay mineral calcined at 500°C, the equilibrium was reached after 150 min only. The maximum adsorption capacity was reached at pH 6.6. Results deducted from the adsorption isotherms also showed that the retention follows the Langmuir model. In addition, it was found that the kinetics were in the order of 2 (K = 2.457 × 106 g/mg.h) for sodium clay and were limited by an intra-particle diffusion. SC was found to be a better adsorbent to remove methylene blue from industrial wastewater. © 2013 Balaban Desalination Publications. All rights reserved.

Adsorption capacity of methylene blue, an organic pollutant, by montmorillonite clay

KAUST Repository

Feddal, I.

2013-11-19

The isotherms and kinetics of the adsorption of a cationic dye in aqueous solution, methylene blue, on a local Algerian montmorillonite clay mineral (raw, sodium and thermally activated at 300 and 500°C) were determined experimentally. Various parameters influencing the adsorption were optimized, mainly solid-liquid contact time, mass of adsorbent, initial concentration of dye, pH of the solution and temperature. Results showed that the adsorption kinetics were fast: 30 min for the raw clay mineral, and 20 min for sodium clay mineral (SC) and thermally activated at 300°C, whereas with the clay mineral calcined at 500°C, the equilibrium was reached after 150 min only. The maximum adsorption capacity was reached at pH 6.6. Results deducted from the adsorption isotherms also showed that the retention follows the Langmuir model. In addition, it was found that the kinetics were in the order of 2 (K = 2.457 × 106 g/mg.h) for sodium clay and were limited by an intra-particle diffusion. SC was found to be a better adsorbent to remove methylene blue from industrial wastewater. © 2013 Balaban Desalination Publications. All rights reserved.

ELECTROCHEMICAL BEHAVIOUR OF METHYLENE BLUE IN NON-AQUEOUS SOLVENTS

International Nuclear Information System (INIS)

Caram, J.A.; Suárez, J.F. Martínez; Gennaro, A.M.; Mirífico, M.V.

2015-01-01

Graphical abstract: Display Omitted - Highlights: • The dye is electro-reduced in two separated monoelectronic charge transfers. • Solvent/supporting electrolyte/acid/base modifies the electrochemical parameters. • A dissociation equilibrium of the dye in non-aqueous solvent is proposed. • The electro-generated and stable dye-radical is also chemically produced in EDA or KOH/DMF. • A new species is reversibly formed in KOH/EtOH or ACN. - Abstract: The electrochemical behaviour of methylene blue in solution of non-aqueous solvents with different supporting electrolytes was studied by cyclic voltammetry. Dye electro-reduction presents two well-defined processes of monoelectronic charge transfer yielding a free radical in the first process and an anion in the second electron transfer. Free radical and anion are long living species in some of the studied media. Effects of supporting electrolyte and solvent on the peak potentials, the peak current functions and the reversibility of the charge transfer processes are reported. A dissociation equilibrium of the dye in solution of non-aqueous solvents and the acid or base added determine markedly the electrochemical responses. In the particular cases of KOH/DMF or EDA basic media the chemical formation of the stable methylene blue radical was detected and it was characterized by EPR spectroscopy. A general reaction scheme is proposed

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

Energy Technology Data Exchange (ETDEWEB)

Lee, Jin-Young, E-mail: jinlee@kigam.re.kr [Metals Recovery Department, Minerals Resources Research Division, Korea Institute of Geoscience and Mineral Resources (KIGAM), 92 Gahangno, Yuesong-gu, Daejeon 305-350 (Korea, Republic of); Rajesh Kumar, J., E-mail: rajeshkumarphd@rediffmail.com [Metals Recovery Department, Minerals Resources Research Division, Korea Institute of Geoscience and Mineral Resources (KIGAM), 92 Gahangno, Yuesong-gu, Daejeon 305-350 (Korea, Republic of); Kim, Joon-Soo; Park, Hyung-Kyu; Yoon, Ho-Sung [Metals Recovery Department, Minerals Resources Research Division, Korea Institute of Geoscience and Mineral Resources (KIGAM), 92 Gahangno, Yuesong-gu, Daejeon 305-350 (Korea, Republic of)

2009-08-30

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{sup -1}. However, at 10 mol L{sup -1} HCl concentration, the extraction behavior was reversed, indicating the solvation type mechanism during extraction. The quantitative extraction of {approx}98% platinum(IV) and 36% rhodium(III) was achieved with 0.01 mol L{sup -1} Alamine 308. The highest separation factor (S.F. = 184.7) of platinum(IV) and rhodium(III) was achieved with 0.01 mol L{sup -1} Alamine 308 at 1.0 mol L{sup -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.

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

International Nuclear Information System (INIS)

Heakal, F. El-Taib; Shehata, O.S.; Tantawy, N.S.

2012-01-01

Highlights: ► Corrosion rate of AM60 in Cl − solution decreases with increasing [Ce 3+ ] up to 1 mM. ► Beyond that level the corrosion rate increases and then stabilizes. ► The spontaneously formed film characterises by increasing resistance with time. ► The converted film after 10 d immersion exhibits self-healing in plain Cl − solution. ► 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 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.

Magnetic graphene sponge for the removal of methylene blue

International Nuclear Information System (INIS)

Yu, Baowei; Zhang, Xiaoliang; Xie, Jingru; Wu, Ruihan; Liu, Xiaoyang; Li, Hongliang; Chen, Fang; Yang, Hua; Ming, Zhu; Yang, Sheng-Tao

2015-01-01

Graphical abstract: - Highlights: • Magnetic graphene sponge is prepared for dye removal in aqueous solution. • Magnetic graphene sponge has an adsorption capacity of 526 mg/g for methylene blue. • Adsorption behaviors of methylene blue on magnetic graphene sponge are investigated. • Magnetic graphene sponge could be partially regenerated by washing with acidic ethanol. - Abstract: Magnetic carbon nanomaterials have been widely adopted as adsorbents in water treatment, but the low adsorption capacities largely limit their practical applications. In this study, magnetic graphene sponge (Fe 3 O 4 -GS) was prepared by lyophilization for the adsorption of dye pollutant. The incorporation of Fe 3 O 4 enabled the magnetic separation of Fe 3 O 4 -GS after the adsorption of methylene blue (MB). The adsorption capacity of Fe 3 O 4 -GS for MB was 526 mg/g, much higher than those of the magnetic carbon nanoadsorbents in the literature. The adsorption kinetics of MB on Fe 3 O 4 -GS was moderately fast, which could be analyzed by the pseudo-second-order model and intraparticle diffusion model. The thermodynamics study revealed that the adsorption was driven by the increased randomness on the interface. The pH and ionic strength had meaningful influences on the adsorption capacity of Fe 3 O 4 -GS. The facile regeneration of Fe 3 O 4 -GS would definitely reduce its operating cost. The implications to the environmental applications of magnetic carbon nanoadsorbents are discussed

SERS-active Ag, Au and Ag–Au alloy nanoparticles obtained by laser ablation in liquids for sensing methylene blue

Energy Technology Data Exchange (ETDEWEB)

Olea-Mejía, Oscar, E-mail: oleaoscar@yahoo.com.mx [Centro Conjunto de Investigación en Química Sustentable UAEM-UNAM, Universidad Autónoma del Estado de México, km 14.5 Carretera Toluca-Atlacomulco, San Cayetano 50200, México (Mexico); Fernández-Mondragón, Mariana; Rodríguez-de la Concha, Gabriela [Centro Conjunto de Investigación en Química Sustentable UAEM-UNAM, Universidad Autónoma del Estado de México, km 14.5 Carretera Toluca-Atlacomulco, San Cayetano 50200, México (Mexico); Camacho-López, Marco [Laboratorio de Investigación y Desarrollo de Materiales Avanzados, Universidad Autónoma del Estado de México, Km 14.5 Carretera Toluca-Atlacomulco, San Cayetano 50925, México (Mexico)

2015-09-01

Highlights: • We synthesized Ag/Au nanoparticles by laser ablation in liquids. • We characterized such particles by UV–vis, TEM and EDS/STEM. • The SERS effect was studied for the obtained nanoparticles. • Pure silver nanoparticles showed the highest SERS signals. • We can sense methylene blue at a concentration of 10{sup −10} mole/L. - Abstract: We have synthesized Ag–Au nanoparticles by laser ablation in liquids using five different targets: 100% Ag, 80%Ag/20%Au, 50%Ag/50%Au, 20%Ag/80%Au and 100% Au (weight percentages). We used ethanol and methylene blue solutions in ethanol as the liquid media. The nanoparticles were mostly spherical with diameters 15, 19, 18, 23 and 11 nm, respectively. When alloyed targets were used, the resulting nanoparticles were completely alloyed forming solid solutions as evidenced by UV–vis Spectroscopy and Scanning Transmission Electron Microscopy. The obtained nanoparticles were employed to study the SERS effect of the methylene blue molecule. All the samples showed good SERS activity, however the ones composed of pure silver showed the greatest Raman signal enhancement. Finally, pure Ag nanoparticles were used for sensing methylene blue at different concentrations. While almost no signal can be discerned from the Raman spectrum when no particles are used at a concentration of methylene blue of 1 × 10{sup −2} M (∼3000 ppm), when Ag nanoparticles are used one can observe the characteristic peak of the molecule at concentrations as low as 1 × 10{sup −10} M (∼3 × 10{sup −5} ppm)

Analysis of corrosion data for carbon steels in simulated salt repository brines and acid chloride solutions at high temperatures

International Nuclear Information System (INIS)

Diercks, D.R.; Hull, A.B.; Kassner, T.F.

1988-03-01

Carbon steel is currently the leading candidate material for fabrication of a container for isolation of high level nuclear waste in a salt repository. Since brine entrapped in the bedded salt can migrate to the container by several transport processes, corrosion is an important consideration in the long-term performance of the waste package. A detailed literature search was performed to compile relevant corrosion data for carbon steels in anoxic acid chloride solutions, and simulated salt repository brines at temperatures between ∼ 20 and 400 0 C. The hydrolysis of Mg 2+ ions in simulated repository brines containing high magnesium concentrations causes acidification at temperatures above 25 0 C, which, in turn, influences the protective nature of the magnetite corrosion product layer on carbon steel. The corrosion data for the steels were analyzed, and an analytical model for general corrosion was developed to calculate the amount of penetration (i.e., wall thinning) as a function of time, temperature, and the pressure of corrosion product hydrogen than can build up during exposure in a closed system (e.g., a sealed capsule). Both the temperature and pressure dependence of the corrosion rate of steels in anoxic acid chloride solutions indicate that the rate-controlling partial reaction is the cathodic reduction of water to form hydrogen. Variations in the composition and microstructure of the steels or the concentration of the ionic species in the chloride solutions (provided that they do not change the pH significantly) do not appear to strongly influence the corrosion rate

Metastable equilibrium for the quaternary system containing with lithium+potassium+magnesium+chloride in aqueous solution at 323K

Energy Technology Data Exchange (ETDEWEB)

Yu, Xudong; Yin, Qinghong; Jiang, Dongbo; Zeng, Ying [Chengdu University of Technology, Chengdu (China)

2014-06-15

The metastable equilibrium of the system contained with lithium, potassium, magnesium, and chloride in aqueous system was investigated at 323 K using an isothermal evaporation method. The isothermal experimental data and physicochemical properties, such as density and refractive index of the equilibrated solution, were determined. With the experimental results, the stereo phase diagram, the projected phase diagram, the water content diagram and the physicochemical properties versus composition diagrams were constructed. The projected phase diagram consists of three invariant points, seven univariant curves and five crystallization fields corresponding to single salts potassium chloride (KCl), lithium chloride monohydrate (LiCl·H{sub 2}O), bischofite (MgCl{sub 2}·6H{sub 2}O) and two double salts lithium carnallite (LiCl·MgCl{sub 2}·7H{sub 2}O) and potassium carnallite (KCl·MgCl{sub 2}·6H{sub 2}O). Salt KCl has the largest crystallization region; it contains almost 95% of the general crystallization field.

Repassivation potentials determination of crevice corrosion of alloy in Chloride solutions

International Nuclear Information System (INIS)

Rincon Ortiz, Mauricio

2009-01-01

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 (E CORR ) is equal or higher than the crevice corrosion repassivation potential (E R,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)

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

International Nuclear Information System (INIS)

Mohmad Soib bin Selamat

1995-01-01

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

Friedel's salt profiles from thermogravimetric analysis and thermodynamic modelling of Portland cement-based mortars exposed to sodium chloride solution

DEFF Research Database (Denmark)

Shi, Zhenguo; Geiker, Mette Rica; Lothenbach, Barbara

2017-01-01

Thermogravimetric analysis (TGA), powder X-ray diffraction (XRD) and thermodynamic modelling have been used to obtain Friedel's salt profiles for saturated mortar cylinders exposed to a 2.8 M NaCl solution. Comparison of the measured Friedel's salt profiles with the total chloride profiles...

A New Property of Conjugated Polymer PFP: Catalytic Degradation of Methylene Blue Aqueous Solution

Institute of Scientific and Technical Information of China (English)

无

2005-01-01

A new property of conjugated polymer poly(furancarbinol-co-phenol)(PFP) was studied.The target copolymer was used as a catalyst after proper heating treatment. And dye methylene blue (MB) could be fully degraded and largely mineralized on PFP, under natural light or even in dark, in a few minutes. Furthermore, the catalytic activity could be preserved after several runs and the catalyst was readily separated. The effect of calcination temperature was also observed.

Desorption and photodegradation of methylene blue from modified sugarcane bagasse surface by acid TiO2 hydrosol

International Nuclear Information System (INIS)

Yu Junxia; Chi Ruan; Guo Jia; Zhang Yuefei; Xu Zhigao; Xiao Chunqiao

2012-01-01

Waste sugarcane bagasse (SCB) was modified by pyromellitic dianhydride to improve its adsorption capacity for cationic dyes. Results showed that the adsorption capacity of the modified SCB for methylene blue was 564 mg g -1 , which was about 12 times than that obtained on the unmodified SCB. Methylene blue loaded modified SCB was regenerated by a self-clean eluent: TiO 2 hydrosol with pH ranged from 1 to 4, and HNO 3 solution with the same pH range was tested at the same time for comparison. Results showed that desorption kinetics of methylene blue in the hydrosol systems fit two-step kinetic model and controlled mainly by the slow step. As a self-clean eluent, acid hydrosol could firstly desorb and then photodegrade methylene blue under sunlight irradiation. After five desorption-photodegradation cycles, 78.3% of the absorbed dyes could be desorbed by using hydrosol (pH 2) as eluent. The hydrosol could be continuously used in desorption and photodegradation process, which would economize large volume of the eluent and moreover it would not bring secondary pollution.

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

Science.gov (United States)

Santos-Sacchi, Joseph; Song, Lei

2016-06-07

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

Repassivation Potential of Alloy 22 in Sodium and Calcium Chloride Brines

International Nuclear Information System (INIS)

Rebak, R B; Ilevbare, G O; Carranza, R M

2007-01-01

A comprehensive matrix of 60 tests was designed to explore the effect of calcium chloride vs. sodium chloride and the ratio R of nitrate concentration over chloride concentration on the repassivation potential of Alloy 22. Tests were conducted using the cyclic potentiodynamic polarization (CPP) technique at 75 C and at 90 C. Results show that at a ratio R of 0.18 and higher nitrate was able to inhibit the crevice corrosion in Alloy 22 induced by chloride. Current results fail to show in a consistent way a different effect on the repassivation potential of Alloy 22 for calcium chloride solutions than for sodium chloride solutions

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

DEFF Research Database (Denmark)

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

2015-01-01

with spray drying and in situ thermogravimetric and structural characterization, we synthesize a range of new, stable barium-strontium chloride solid solutions with superior ammonia storage densities. By tuning the barium/strontium ratio, different crystallographic phases and compositions can be obtained...... with different ammonia ab- and desorption properties. In particular it is shown, that in the molar range of 35–50% barium and 65–50% strontium, stable materials can be produced with a practically usable ammonia density (both volumetric and gravimetric) that is higher than any of the pure metal halides...

Physicochemical characterization of berberine chloride: a perspective in the development of a solution dosage form for oral delivery.

Science.gov (United States)

Battu, Sunil Kumar; Repka, Michael A; Maddineni, Sindhuri; Chittiboyina, Amar G; Avery, Mitchell A; Majumdar, Soumyajit

2010-09-01

The objective of the present research was to evaluate the physicochemical characteristics of berberine chloride and to assess the complexation of drug with 2-hydroxypropyl-β-cyclodextrin (HPβCD), a first step towards solution dosage form development. The parameters such as log P value were determined experimentally and compared with predicted values. The pH-dependent aqueous solubility and stability were investigated following standard protocols at 25°C and 37°C. Drug solubility enhancement was attempted utilizing both surfactants and cyclodextrins (CDs), and the drug/CD complexation was studied employing various techniques such as differential scanning calorimetry, Fourier transform infrared, nuclear magnetic resonance, and scanning electron microscopy. The experimental log P value suggested that the compound is fairly hydrophilic. Berberine chloride was found to be very stable up to 6 months at all pH and temperature conditions tested. Aqueous solubility of the drug was temperature dependent and exhibited highest solubility of 4.05 ± 0.09 mM in phosphate buffer (pH 7.0) at 25°C, demonstrating the effect of buffer salts on drug solubility. Decreased drug solubility was observed with increasing concentrations of ionic surfactants such as sodium lauryl sulfate and cetyl trimethyl ammonium bromide. Phase solubility studies demonstrated the formation of berberine chloride-HPβCD inclusion complex with 1:1 stoichiometry, and the aqueous solubility of the drug improved almost 4.5-fold in the presence of 20% HPβCD. The complexation efficiency values indicated that the drug has at least threefold greater affinity for hydroxypropyl-β-CD compared to randomly methylated-β-CD. The characterization techniques confirmed inclusion complex formation between berberine chloride and HPβCD and demonstrated the feasibility of developing an oral solution dosage form of the drug.

Studies on volumetric properties 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. [Department of Chemistry, Guru Nanak Dev University, Amritsar 143 005 (India)], E-mail: pkbanipal@yahoo.com; Chahal, Amanpreet K. [Department of Chemistry, Guru Nanak Dev University, Amritsar 143 005 (India); Banipal, Tarlok S. [Department of Applied Chemistry, Guru Nanak Dev University, Amritsar 143 005 (India)

2009-04-15

The standard partial molar volumes, V{sub 2}{sup {infinity}} at infinite dilution of monosaccharides; D(+)-xylose, D(-)-arabinose, D(-)-ribose, D(+)-mannose, D(+)-galactose, D(-)-fructose and D(+)-glucose, disaccharides; D(+)-melibiose, D(+)-cellobiose, D(+)-maltose monohydrate, D(+)-trehalose dihydrate, D(+)-lactose monohydrate and sucrose, trisaccharide; D(+)-raffinose pentahydrate, methylglycosides; {alpha}-methyl-D(+)-glucoside, methyl-{alpha}-D-xylopyranoside and methyl-{beta}-D-xylopyranoside have been determined in water and in aqueous solutions of potassium chloride (0.5, 1.0, 2.0, and 3.0) mol . kg{sup -1} at T = (288.15, 298.15, 308.15, and 318.15) K from density measurements employing a vibrating-tube densimeter. These results have been utilized to determine the corresponding standard partial molar volumes of transfer, {delta}{sub t}V{sub 2}{sup {infinity}} for the transfer of various saccharides from water to aqueous potassium chloride solutions. The standard transfer volumes have been found to be positive (except for {alpha}- and {beta}-methyl xylopyranosides in 0.5 mol . kg{sup -1} solutions of potassium chloride) whose magnitude increase with the concentration of potassium chloride as well as temperature for all the saccharides. Partial molar expansion coefficients, ({partial_derivative}V{sub 2}{sup {infinity}}/{partial_derivative}T){sub p} and the second derivative ({partial_derivative}{sup 2}V{sub 2}{sup {infinity}}/{partial_derivative}T{sup 2}){sub p} values have been estimated. Pair and higher order volumetric interaction coefficients have also been calculated from {delta}{sub t}V{sub 2}{sup {infinity}} by using the McMillan-Mayer theory. These parameters have been discussed in terms of the solute-cosolute interactions and are used to understand various mixing effects due to these interactions. The effect of substitution of -OH by glycosidic group, -OCH{sub 3} is also discussed. Attempt has also been made to discuss the stereochemical effects

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

Directory of Open Access Journals (Sweden)

Hassoune Mohammed

2018-01-01

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

Synergistic effect of pulsed corona discharges and ozonation on decolourization of methylene blue in water

Energy Technology Data Exchange (ETDEWEB)

Malik, Muhammad Arif [Applied Chemistry Division, PINSTECH, PO Nilore, Islamabad (Pakistan); Ubaid-ur-Rehman [Applied Chemistry Division, PINSTECH, PO Nilore, Islamabad (Pakistan); Ghaffar, Abdul; Ahmed, Kurshid [Electronics Division, PINSTECH, PO Nilore, Islamabad (Pakistan)

2002-08-01

The effect of O{sub 2} and O{sub 3} bubbling on decolourization of methylene blue by pulsed corona discharges in water was studied. The pulsed corona discharges were produced by charging an 80 pF capacitor with a 40 kV DC source, through a 100 M{omega} resistor, and discharging it into a needle-plate type reactor at 60 Hz through a rotating spark gap switch. A 20 ml sample of 13.25 mg l{sup -1} methylene blue in distilled water was decolourized in 120 min. Bubbling O{sub 2} at 10 ml min{sup -1} through the discharge region reduced the decolourization time to 25 min. Bubbling O{sub 2} containing 1500 {mu}mol O{sub 3} l{sup -1} at 10 ml min{sup -1} reduced the decolourization time to 8 min. The O{sub 3} was produced by fractionating input energy between a water treatment reactor and a O{sub 3} generator, i.e. no additional energy was consumed for O{sub 3} production. Under the same experimental conditions methylene blue solution in tap water was decolourized in >210 min by corona discharge in solution, in 30 min by corona discharge with O{sub 2} bubbling, and in 11 min by corona discharge with bubbling of O{sub 2} containing 1500 {mu}mol O{sub 3} l{sup -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.

Removal of methylene blue from aqueous solution by chaff in batch mode

International Nuclear Information System (INIS)

Han Runping; Wang Yuanfeng; Han Pan; Shi Jie; Yang Jian; Lu Yongsen

2006-01-01

A new adsorbent system for removing methylene blue (MB) from aqueous solutions has been investigated. This new adsorbent is cereal chaff, an agriculture product in middle-west region in China. Variables of the system, including biosorption time, chaff dose, pH, salt concentration and initial MB concentration, were adopted to study their effects on MB removal. The results showed that as the dose of chaff increased, the percentage of MB sorption increased accordingly. There was no significant difference in the dye concentration remaining when the pH was increased from 4.0 to 11.0. The salt concentration has negative effect on MB removal. At the experimental range of MB concentration, the amount of MB adsorbed onto per unit mass of chaff (q e ) is direct ratio to MB initial concentration (c 0 ). The equilibrium data were analyzed using five equilibrium models, the Langmuir, the Freundlich, the Redlich-Peterson, the Koble-Corrigan and the Temkin isotherms. The results of non-linear regressive analysis are that the isotherms of Langmuir, Redlich-Peterson and Koble-Corrigan are better fit than the isotherms of Freundlich and Temkin at different temperatures according to the values of determined coefficients (R 2 ) and Chi-square statistic (χ 2 ). The maximum equilibrium capacities of chaff from Langmuir models are 20.3, 25.3 and 26.3 mg g -1 at 298, 318 and 333 K, respectively. Using the equilibrium concentration constants obtained at different temperatures, various thermodynamic parameters, such as ΔG 0 , ΔH 0 and ΔS 0 , have been calculated. The thermodynamics parameters of MB/chaff system indicate spontaneous and endothermic process. It was concluded that an increase in temperature results in a bigger MB loading per unit weight of the chaff

Local toxicity of benzalkonium chloride in ophthalmic solutions following repeated applications.

Science.gov (United States)

Okahara, Akihiko; Kawazu, Kouichi

2013-01-01

We performed repeated toxicity studies of benzalkonium chloride (BAK)-containing vehicles of ophthalmic solutions in monkeys and rabbits to assess the local toxicity of BAK after repeated applications on the ocular surface. Local toxicity of BAK was evaluated by toxicity studies in which a 0.01% BAK-containing vehicle was applied twice/day for 52 weeks, 4 times/day for 39 weeks, or 6 times/day for 13 weeks, or in which a 0.005% BAK-containing vehicle was applied 6 times/day for 52 weeks or twice/day for 4 weeks in monkeys. Local toxicity of BAK was also evaluated where a 0.01% BAK-containing vehicle was applied 6 times/day for 6 weeks, or a 0.005% BAK-containing vehicle was applied twice/day for 39 weeks or 8 times/day for 4 weeks in rabbits. These doses were chosen because BAK is generally used at concentrations up to 0.01% in ophthalmic solutions. The BAK-containing vehicle did not cause ophthalmological changes suggestive of irritation, allergy, or corneal damage. We also did not observe any histopathological changes in the eyeball, eyelid, lacrimal gland, and nasal cavity, with repeated applications of BAK for up to 52 weeks, up to 8 times/day, or at concentrations up to 0.01%, in monkeys and rabbits. Our results suggest that BAK in concentrations up to 0.01% in ophthalmic solution is non-toxic to the eyeball, its accessory organs, and the nasal cavity after long repeated applications.

Magnetic graphene sponge for the removal of methylene blue

Energy Technology Data Exchange (ETDEWEB)

Yu, Baowei; Zhang, Xiaoliang; Xie, Jingru; Wu, Ruihan; Liu, Xiaoyang; Li, Hongliang; Chen, Fang; Yang, Hua; Ming, Zhu; Yang, Sheng-Tao, E-mail: yangst@pku.edu.cn

2015-10-01

Graphical abstract: - Highlights: • Magnetic graphene sponge is prepared for dye removal in aqueous solution. • Magnetic graphene sponge has an adsorption capacity of 526 mg/g for methylene blue. • Adsorption behaviors of methylene blue on magnetic graphene sponge are investigated. • Magnetic graphene sponge could be partially regenerated by washing with acidic ethanol. - Abstract: Magnetic carbon nanomaterials have been widely adopted as adsorbents in water treatment, but the low adsorption capacities largely limit their practical applications. In this study, magnetic graphene sponge (Fe{sub 3}O{sub 4}-GS) was prepared by lyophilization for the adsorption of dye pollutant. The incorporation of Fe{sub 3}O{sub 4} enabled the magnetic separation of Fe{sub 3}O{sub 4}-GS after the adsorption of methylene blue (MB). The adsorption capacity of Fe{sub 3}O{sub 4}-GS for MB was 526 mg/g, much higher than those of the magnetic carbon nanoadsorbents in the literature. The adsorption kinetics of MB on Fe{sub 3}O{sub 4}-GS was moderately fast, which could be analyzed by the pseudo-second-order model and intraparticle diffusion model. The thermodynamics study revealed that the adsorption was driven by the increased randomness on the interface. The pH and ionic strength had meaningful influences on the adsorption capacity of Fe{sub 3}O{sub 4}-GS. The facile regeneration of Fe{sub 3}O{sub 4}-GS would definitely reduce its operating cost. The implications to the environmental applications of magnetic carbon nanoadsorbents are discussed.

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

International Nuclear Information System (INIS)

De Weerdt, K.; Colombo, A.; Coppola, L.; Justnes, H.; Geiker, M.R.

2015-01-01

Well hydrated cement paste was exposed to MgCl 2 , CaCl 2 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 Mg 2 + or Ca 2 + 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

Methylene blue adsorption by algal biomass based materials: biosorbents characterization and process behaviour.

Science.gov (United States)

Vilar, Vítor J P; Botelho, Cidália M S; Boaventura, Rui A R

2007-08-17

Dead algal biomass is a natural material that serves as a basis for developing a new family of sorbent materials potentially suitable for many industrial applications. In this work an algal industrial waste from agar extraction process, algae Gelidium and a composite material obtained by immobilization of the algal waste with polyacrylonitrile (PAN) were physical characterized and used as biosorbents for dyes removal using methylene blue as model. The apparent and real densities and the porosity of biosorbents particles were determined by mercury porosimetry and helium picnometry. The methylene blue adsorption in the liquid phase was the method chosen to calculate the specific surface area of biosorbent particles as it seems to reproduce better the surface area accessible to metal ions in the biosorption process than the N2 adsorption-desorption dry method. The porous texture of the biosorbents particles was also studied. Equilibrium isotherms are well described by the Langmuir equation, giving maximum uptake capacities of 171, 104 and 74 mg g(-1), respectively for algae, algal waste and composite material. Kinetic experiments at different initial methylene blue concentrations were performed to evaluate the equilibrium time and the importance of the driving force to overcome mass transfer resistances. The pseudo-first-order and pseudo-second-order kinetic models adequately describe the kinetic data. The biosorbents used in this work proved to be promising materials for removing methylene blue from aqueous solutions.

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.

Binding of chloride and alkalis in Portland cement systems

International Nuclear Information System (INIS)

Nielsen, Erik P.; Herfort, Duncan; Geiker, Mette R.

2005-01-01

A thermodynamic model for describing the binding of chloride and alkalis in hydrated Portland cement pastes has been developed. The model is based on the phase rule, which for cement pastes in aggressive marine environment predicts multivariant conditions, even at constant temperature and pressure. The effect of the chloride and alkalis has been quantified by experiments on cement pastes prepared from white Portland cements containing 4% and 12% C 3 A, and a grey Portland cement containing 7% C 3 A. One weight percent calcite was added to all cements. The pastes prepared at w/s ratio of 0.70 were stored in solutions of different Cl (CaCl 2 ) and Na (NaOH) concentrations. When equilibrium was reached, the mineralogy of the pastes was investigated by EDS analysis on the SEM. A well-defined distribution of chloride was found between the pore solution, the C-S-H phase, and an AFm solid solution phase consisting of Friedel's salt and monocarbonate. Partition coefficients varied as a function of iron and alkali contents. The lower content of alkalis in WPC results in higher chloride contents in the C-S-H phase. High alkali contents result in higher chloride concentrations in the pore solution

Fabrication of the novel hydrogel based on waste corn stalk for removal of methylene blue dye from aqueous solution

Science.gov (United States)

Ma, Dongzhuo; Zhu, Baodong; Cao, Bo; Wang, Jian; Zhang, Jianwei

2017-11-01

The novel hydrogel based on waste corn stalk was synthetized by aqueous solution polymerization technique with functional monomers in the presence of organic montmorillonite (OMMT) under ultrasonic. In this study, batch adsorption experiments were carried out to research the effect of initial dye concentration, the dosage of hydrogel, stirring speed, contact time and temperature on the adsorption of methylene blue (MB) dye. The adsorption process was best described by the pseudo-second-order kinetic model, which confirmed that it should be a chemical process. Furthermore, we ascertained the rate controlling step by establishing the intraparticle diffusion model and the liquid film diffusion model. The adsorption and synthesis mechanisms were vividly depicted in our work as well. Structural and morphological characterizations by virtue of FTIR, FESEM, and Biomicroscope supported the relationship between the adsorption performance and material's microstructure. This research is a valuable contribution for the environmental protection, which not only converts waste corn stalks into functional materials, but improves the removal of organic dye from sewage water.

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

Energy Technology Data Exchange (ETDEWEB)

Bialy, Agata [Amminex Emissions Technology A/S, Gladsaxevej 363, 2860 Soeborg (Denmark); Jensen, Peter B. [Department of Energy Conversion and Storage, Technical University of Denmark, Frederiksborgvej 399, DK-4000 Roskilde (Denmark); Center for Atomic-scale Materials Design, Department of Physics, Technical University of Denmark, Fysikvej 311, DK-2800 Kgs. Lyngby (Denmark); Blanchard, Didier [Department of Energy Conversion and Storage, Technical University of Denmark, Frederiksborgvej 399, DK-4000 Roskilde (Denmark); Vegge, Tejs, E-mail: teve@dtu.dk [Department of Energy Conversion and Storage, Technical University of Denmark, Frederiksborgvej 399, DK-4000 Roskilde (Denmark); Quaade, Ulrich J., E-mail: ujq@amminex.com [Amminex Emissions Technology A/S, Gladsaxevej 363, 2860 Soeborg (Denmark)

2015-01-15

Metal halide ammines are very attractive materials for ammonia absorption and storage—applications where the practically accessible or usable gravimetric and volumetric storage densities are of critical importance. Here we present, that by combining advanced computational materials prediction with spray drying and in situ thermogravimetric and structural characterization, we synthesize a range of new, stable barium-strontium chloride solid solutions with superior ammonia storage densities. By tuning the barium/strontium ratio, different crystallographic phases and compositions can be obtained with different ammonia ab- and desorption properties. In particular it is shown, that in the molar range of 35–50% barium and 65–50% strontium, stable materials can be produced with a practically usable ammonia density (both volumetric and gravimetric) that is higher than any of the pure metal halides, and with a practically accessible volumetric ammonia densities in excess of 99% of liquid ammonia. - Graphical abstract: Thermal desorption curves of ammonia from Ba{sub x}Sr{sub (1−x)}Cl{sub 2} mixtures with x equal to 0.125, 0.25 and 0.5 and atomic structure of Sr(NH{sub 3}){sub 8}Cl{sub 2}. - Highlights: • Solid solutions of strontium and barium chloride were synthesized by spray drying. • Adjusting molar ratios led to different crystallographic phases and compositions. • Different molar ratios led to different ammonia ab-/desorption properties. • 35–50 mol% BaCl{sub 2} in SrCl{sub 2} yields higher ammonia density than any other metal halide. • DFT calculations can be used to predict properties of the mixtures.

Anodic solution of alkali earth alloys in potassium chloride-sodium chloride melts

International Nuclear Information System (INIS)

Volkovich, A.V.

1997-01-01

Generalized results of studying the process of anodic dissolution of alkaline-earth metal alloys with zinc, aluminium and copper in the melts of KCl-NaCl equimolar mixture containing alkaline-earth metal chlorides, are presented. It is shown that during dissolution of both pure liquid metals and their alloys there is no electrode polarization in the range of the current densities lower or comparable in their values to corrosion current

Chloride removal from plutonium alloy

International Nuclear Information System (INIS)

Holcomb, H.P.

1983-01-01

SRP is evaluating a program to recover plutonium from a metallic alloy that will contain chloride salt impurities. Removal of chloride to sufficiently low levels to prevent damaging corrosion to canyon equipment is feasible as a head-end step following dissolution. Silver nitrate and mercurous nitrate were each successfully used in laboratory tests to remove chloride from simulated alloy dissolver solution containing plutonium. Levels less than 10 ppM chloride were achieved in the supernates over the precipitated and centrifuged insoluble salts. Also, less than 0.05% loss of plutonium in the +3, +4, or +6 oxidation states was incurred via precipitate carrying. These results provide impetus for further study and development of a plant-scale process to recover plutonium from metal alloy at SRP

Extractive process for preparing high purity magnesium chloride hexahydrate

Directory of Open Access Journals (Sweden)

Fezei Radouanne

2012-01-01

Full Text Available This paper refers a method for the preparation of magnesium chloride hexahydrate (bischofite from Sebkha el Melah of Zarzis Tunisian natural brine. It is a five-stage process essentially based on crystallization by isothermal evaporation and chemical precipitation. The two first steps were dedicated to the crystallization of sodium chloride and potassiummagnesium double salts, respectively. Then, the resulting liquor was desulfated using calcium chloride solution. After that another isothermal evaporation stage was implemented in order to eliminate potassium ions in the form of carnallite, KCl.MgCl2.6H2O. At the end of this step, the recovered solution primarily composed of magnesium and chloride ions was treated by dioxan in order to precipitate magnesium chloride as MgCl2.6H2O.C4H8O2. This compound dried at constant temperature of 100°C gave good quality magnesium chloride hexahydrate. Besides this salt, the various by-products obtained from the different treatment stages are also useful.

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

International Nuclear Information System (INIS)

Xu Weifeng; Liu Jinhe; Zhu Hongqiang

2010-01-01

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.

Mercury toxicity in the shark (Squalus acanthias) rectal gland: apical CFTR chloride channels are inhibited by mercuric chloride.

Science.gov (United States)

Ratner, Martha A; Decker, Sarah E; Aller, Stephen G; Weber, Gerhard; Forrest, John N

2006-03-01

In the shark rectal gland, basolateral membrane proteins have been suggested as targets for mercury. To examine the membrane polarity of mercury toxicity, we performed experiments in three preparations: isolated perfused rectal glands, primary monolayer cultures of rectal gland epithelial cells, and Xenopus oocytes expressing the shark cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel. In perfused rectal glands we observed: (1) a dose-dependent inhibition by mercury of forskolin/3-isobutyl-1-methylxanthine (IBMX)-stimulated chloride secretion; (2) inhibition was maximal when mercury was added before stimulation with forskolin/IBMX; (3) dithiothrietol (DTT) and glutathione (GSH) completely prevented inhibition of chloride secretion. Short-circuit current (Isc) measurements in monolayers of rectal gland epithelial cells were performed to examine the membrane polarity of this effect. Mercuric chloride inhibited Isc more potently when applied to the solution bathing the apical vs. the basolateral membrane (23 +/- 5% and 68 +/- 5% inhibition at 1 and 10 microM HgCl2 in the apical solution vs. 2 +/- 0.9% and 14 +/- 5% in the basolateral solution). This inhibition was prevented by pre-treatment with apical DTT or GSH; however, only the permeant reducing agent DTT reversed mercury inhibition when added after exposure. When the shark rectal gland CFTR channel was expressed in Xenopus oocytes and chloride conductance was measured by two-electrode voltage clamping, we found that 1 microM HgCl2 inhibited forskolin/IBMX conductance by 69.2 +/- 2.0%. We conclude that in the shark rectal gland, mercury inhibits chloride secretion by interacting with the apical membrane and that CFTR is the likely site of this action. Copyright 2006 Wiley-Liss, Inc.

Study of the Conformational State of Non-Cross-Linked and Cross-Linked Poly(alkylmethyldiallylammonium chlorides) in Aqueous Solution by Fluorescence Probing

NARCIS (Netherlands)

Wang, Guang-Jia; Engberts, Jan B.F.N.

The aggregation behaviour of novel non-cross-linked and cross-linked poly(alkylmethyldiallylammonium chlorides) in aqueous solutions has been investigated by fluorescence spectroscopy using pyrene as a probe. These copolymers were found to exhibit similar aggregate properties as the corresponding

Analysis of the corrosion of carbon steels in simulated salt repository brines and acid chloride solutions at high temperatures

International Nuclear Information System (INIS)

Diercks, D.R.; Kassner, T.F.

1988-04-01

An analysis of literature data on the corrosion of carbon steels in anoxic brines and acid chloride solutions was performed, and the results were used to assess the expected life of high-level nuclear waste package containers in a salt repository environment. The corrosion rate of carbon steels in moderately acidic aqueous chloride environments obeys an Arrhenius dependence on temperature and a (pH 2 ) -1/2 dependence on hydrogen partial pressure. The cathodic reduction of water to produce hydrogen is the rate-controlling step in the corrosion process. An expression for the corrosion rate incorporating these two dependencies was used to estimate the corrosion life of several proposed waste package configurations. 42 refs., 11 figs., 2 tabs

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. This journal is © the Owner Societies 2011

The extraction of vanadium (IV) from hydrochloric acid solutions by tricaprylmethylammonium chloride and trioctylamine

International Nuclear Information System (INIS)

Nakamura, Takato; Sato, Taichi

1980-01-01

The extraction of vanadium (IV) from hydrochloric acid solutions by tricaprylmethylammonium chloride (R 3 RNCl, Aliquat-336) and trioctylamine (R 3 N, TOA) in benzene has been investigated under various conditions. In addition, the extraction behaviour of vanadium into the organic phase has been examined by spectrophotometry and electron spin resonance (ESR) spectroscopy. From the distribution data, it is concluded that the extractions of vanadium (IV) from hydrochloric acid solutions by Aliquat-336 and TOA are expressed as VOCl 3 - (aq) + R 3 R'NCl(org) reversible R 3 R'NVOCl 3 (org) + Cl - (aq) and VOCl 2 (aq) + R 3 NHCl(org) reversible R 3 NHVOCl 3 (org) The electronic spectral and ESR results suggest that the complexes, R 3 R'NVOCl 3 and R 3 NH.VOCl 3 , formed in the organic phase are not always stable, but easily hydrolized or oxidized. (author)

Microwave atmospheric pressure plasma jets for wastewater treatment: Degradation of methylene blue as a model dye.

Science.gov (United States)

García, María C; Mora, Manuel; Esquivel, Dolores; Foster, John E; Rodero, Antonio; Jiménez-Sanchidrián, César; Romero-Salguero, Francisco J

2017-08-01

The degradation of methylene blue in aqueous solution as a model dye using a non thermal microwave (2.45 GHz) plasma jet at atmospheric pressure has been investigated. Argon has been used as feed gas and aqueous solutions with different concentrations of the dye were treated using the effluent from plasma jet in a remote exposure. The removal efficiency increased as the dye concentration decreased from 250 to 5 ppm. Methylene blue degrades after different treatment times, depending on the experimental plasma conditions. Thus, kinetic constants up to 0.177 min -1 were obtained. The higher the Ar flow, the faster the degradation rate. Optical emission spectroscopy (OES) was used to gather information about the species present in the gas phase, specifically excited argon atoms. Argon excited species and hydrogen peroxide play an important role in the degradation of the dye. In fact, the conversion of methylene blue was directly related to the density of argon excited species in the gas phase and the concentration of hydrogen peroxide in the aqueous liquid phase. Values of energy yield at 50% dye conversion of 0.296 g/kWh were achieved. Also, the use of two plasma applicators in parallel has been proven to improve energy efficiency. Copyright © 2017 Elsevier Ltd. All rights reserved.

Chloride Ion Adsorption Capacity of Anion Exchange Resin in Cement Mortar

Directory of Open Access Journals (Sweden)

Yunsu Lee

2018-04-01

Full Text Available This paper presents the effect of anion exchange resin (AER on the adsorption of chloride ions in cement mortar. The kinetic and equilibrium behaviors of AER were investigated in distilled water and Ca(OH2 saturated solutions, and then the adsorption of chloride ions by the AER in the mortar specimen was determined. The AER was used as a partial replacement for sand in the mortar specimen. The mortar specimen was coated with epoxy, except for an exposed surface, and then immersed in a NaCl solution for 140 days. The chloride content in the mortar specimen was characterized by energy dispersive X-ray fluorescence analysis and electron probe microanalysis. The results showed that the AER could adsorb the chloride ions from the solution rapidly but had a relatively low performance when the pH of its surrounding environment increased. When the AER was mixed in the cement mortar, its chloride content was higher than that of the cement matrix around it, which confirms the chloride ion adsorption capacity of the AER.

Detection of colloidal silver chloride near solubility limit

Science.gov (United States)

Putri, K. Y.; Adawiah, R.

2018-03-01

Detection of nanoparticles in solution has been made possible by several means; one of them is laser-induced breakdown detection (LIBD). LIBD is able to distinguish colloids of various sizes and concentrations. This technique has been used in several solubility studies. In this study, the formation of colloids in a mixed system of silver nitrate and sodium chloride was observed by acoustic LIBD. Silver chloride has low solubility limit, therefore LIBD measurement is appropriate. Silver and chloride solutions with equal concentrations, set at below and above the solubility of silver chloride as the expected solid product, were mixed and the resulting colloids were observed. The result of LIBD measurement showed that larger particles were present as more silver and chloride introduced. However, once the concentrations exceeded the solubility limit of silver chloride, the detected particle size seemed to be decreasing, hence suggested the occurrence of coprecipitation process. This phenomenon indicated that the ability of LIBD to detect even small changes in colloid amounts might be a useful tool in study on formation and stability of colloids, i.e. to confirm whether nanoparticles synthesis has been successfully performed and whether the system is stable or not.

Determination of chloride in water. A comparison of three methods

International Nuclear Information System (INIS)

Steele, P.J.

1978-09-01

The presence of chloride in the water circuits of nuclear reactors, power stations and experimental rigs is undesirable because of the possibility of corrosion. Three methods are considered for the determination of chloride in water in the 0 to 10 μg ml -1 range. The potentiometric method, using a silver-silver chloride electrode, is capable of determining chloride above the 0.1μg ml -1 level, with a standard deviation of 0.03 to 0.12 μg ml -1 in the range 0.1 to 6.0 μg ml -1 chloride. Bromide, iodide and strong reducing agents interfere but none of the cations likely to be present has an effect. The method is very susceptible to variations in temperature. The turbidimetric method involves the production of suspended silver chloride by the addition of silver nitride solution to the sample. The method is somewhat unreliable and is more useful as a rapid, routine limit-testing technique. In the third method, chloride in the sample is pre-concentrated by co-precipitation on lead phosphate, redissolved in acidified ferric nitrate solution and determined colorimetrically by the addition of mercuric thiocyanate solution. It is suitable for determining chloride in the range 0 to 50 μg, using a sample volume of 100 to 500 ml. None of the chemical species likely to be present interferes. In all three methods, chloride contamination can occur at any point in the determination. Analyses should be carried out in conditions where airborne contamination is minimised and a high degree of cleanliness must be maintained. (author)

Study and application of new chelating resin to recovery uranium from in-situ leach solution with high content saline chloride ion

International Nuclear Information System (INIS)

Zhang Jianguo; Qiu Yueshuang; Feng Yu; Deng Huidong; Zhao Chaoya

2014-01-01

Research on the adsorption and elution property of D814 chelating resin was carried out aiming at the difficult separation of uranium from high content saline chloride ion in situ leach liquor and the adsorption mechanism is also discussed. Influence factors such as contact time, pH value, Ca"2"+, Mg"2"+ and Cl"- concentration etc. to the resin adsorption were studied. Experimental results show that adsorption rate is lowly which need 6h to arrive at the adsorption equilibrium. The resin adsorption uranium pH in the solution is from l.33 to 9. When total salinity is over 20 g/L, calcium ion, and magnesium ion is about 3 g/L, there are no big influence on resin adsorption capacity. The resin has good chloride ion resistance. When chloride ion is over 60 g/L, it is no influence on resin adsorption uranium. Column experiment results indicate that ratio of saturation volume to break-through point volume is l.82, resin saturation uranium capacity is 40.5 mg. U/_g_(_∓_)_R. When elution volume bed number is 23, the eluted solution uranium concentration is below 80 mg/L. The elution rate of the uranium is 96.2%. (authors)

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.

Potentiometric titration of uranium reduced by chromic salts in chloridic solutions; Titulacao potenciometrica de uranio reduzido por sais cromosos em solucoes cloridricas

Energy Technology Data Exchange (ETDEWEB)

Coutinho, C M.C.; Bastos, E T.R.

1986-06-01

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.).

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

International Nuclear Information System (INIS)

Apelblat, Alexander; Korin, Eli

2007-01-01

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

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.

Visible Light-Induced Degradation of Methylene Blue in the Presence of Photocatalytic ZnS and CdS Nanoparticles

Directory of Open Access Journals (Sweden)

Parisa Vaziri

2012-09-01

Full Text Available ZnS and CdS nanoparticles were prepared by a simple microwave irradiation method under mild conditions. The obtained nanoparticles were characterized by XRD, TEM and EDX. The results indicated that high purity of nanosized ZnS and CdS was successfully obtained with cubic and hexagonal crystalline structures, respectively. The band gap energies of ZnS and CdS nanoparticles were estimated using UV-visible absorption spectra to be about 4.22 and 2.64 eV, respectively. Photocatalytic degradation of methylene blue was carried out using physical mixtures of ZnS and CdS nanoparticles under a 500-W halogen lamp of visible light irradiation. The residual concentration of methylene blue solution was monitored using UV-visible absorption spectrometry. From the study of the variation in composition of ZnS:CdS, a composition of 1:4 (by weight was found to be very efficient for degradation of methylene blue. In this case the degradation efficiency of the photocatalyst nanoparticles after 6 h irradiation time was about 73% with a reaction rate of 3.61 × 10−3 min−1. Higher degradation efficiency and reaction rate were achieved by increasing the amount of photocatalyst and initial pH of the solution.

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)

Shen Shaobo; Pan Tonglin; Liu Xinqiang; Yuan Lei; Wang Jinchao; Zhang Yongjian; Guo Zhanchen

2010-01-01

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 (K d ) 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 Q max 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.

Crystal Violet and Methylene Green as Low-Dose Liquid Dosimetry Systems

International Nuclear Information System (INIS)

Ebraheem, S.; Beshir, W.B.; Hassan, H.M.

2008-01-01

The ultimate aim of the present work is studying of the possibility of using some organic solutions for gamma radiation monitors and to evaluate and characterize the dosimetric properties of these compounds. Crystal violet (CV) and methylene green (MG) aqueous solutions with different concentrations have been prepared and irradiated to different absorbed doses. The solutions were readout using absorption spectrophotometry technique at λ m ax 592 nm and 614 nm for CV and MG respectively. The maximum useful dose range was investigated and found to be concentration dependent. It was found that the useful dose range was from 10-160 Gy for CV and from 10-200 Gy for MG. The radiation chemical yield, G-value, was calculated for the studied solutions. The ph effect and the effect of different additives, chloral hydrate and ethanol have been also investigated. The pre- and post- irradiation stabilities of these solutions under different storage conditions were studied and the results showed different significant dependence on the storage condition

Concentration determination of methyl magnesium chloride and other Grignard reagents by potentiometric titration with in-line characterization of reaction species by FTIR spectroscopy.

Science.gov (United States)

Chen, Yadan; Wang, Tao; Helmy, Roy; Zhou, George X; LoBrutto, Rosario

2002-07-01

A potentiometric titration method for methyl magnesium chloride and other Grignard reagents based on the reaction with 2-butanol in THF has been developed and validated. The method employs a commercially available platinum electrode, using an electrolyte compatible with non-aqueous solvents. Well-defined titration curves were obtained, along with excellent method precision. The endpoint was precisely determined based on the first derivative of the titration curve. Different solvents such as THF, diethyl ether and methylene chloride provided similar results with regard to sharpness of the endpoint and method precision. The method was applied to a wide array of Grignard reagents including methyl magnesium bromide, ethyl magnesium chloride, propyl magnesium chloride, vinyl magnesium chloride, phenyl magnesium chloride, and benzyl magnesium chloride with similar precision and accuracy. Application of in-line FTIR was demonstrated for in situ monitoring of the titration reaction, allowing characterization of the reaction species. An authentic spectrum of the MeMgCl-THF complex was obtained using spectral subtraction and the vibrational absorbance bands were identified. FTIR also provided an alternative for detecting the titration endpoint, and the titration results so obtained, provided a cross-validation of the accuracy of the potentiometric titration.

Synthesis of 1,3-Dimethylimidazolium Chloride and Volumetric Property Investigations of Its Aqueous Solution

Science.gov (United States)

Dong, L.; Zheng, D. X.; Wei, Z.; Wu, X. H.

2009-10-01

By investigating the vapor pressure of the solvent and the affinity between ionic liquids (ILs) and the solvent, it is proposed that 1,3-dimethylimidazolium chloride ([Mmim]Cl) has the potential to be used as a novel absorbent species with the absorption cycle working fluid. Adopting a high-pressure reaction kettle, the method of gas-liquid phase reaction was used to synthesize [Mmim]Cl under the conditions of 348.15 K and 0.7 MPa. The densities of [Mmim]Cl aqueous solutions were measured for mass fractions in the range from 20% to 90% at 293.15 K, 298.15 K, 303.15 K, 308.15 K, 313.15 K, and 318.15 K with a digital vibrating-tube densimeter. The excess volume, the apparent molar volume, the partial molar volume, and the apparent molar expansibility of this system were investigated, and the influences of variations of the cation and anion on the density of several IL aqueous solutions are discussed.

Behaviour of trivalent actinides and lanthanide elements in chloride solution; Comportement des lanthanides et transuraniens trivalents en milieu chlorhydrique

Energy Technology Data Exchange (ETDEWEB)

Marin, B [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1969-07-01

The aim of this work is to compare the complexation in chloride solutions of trivalent lanthanides and actinides. We have first studied the solvatation of these cations without complexation. We found a difference between Am, Cm and Rare Earths (we can separate lanthanides into Light and Heavy Rare Earths). For studying the complexation we choose the technic of electrophoresis on paper after establishing a simple theory of mobilities in complex solutions. The hydrolysis of these cations was studied and compared in chloride solutions. We have then studied the complexation with the Cl{sup -} ligand in some solutions: HCl, NH{sub 4}Cl, CaCl{sub 2}, CeCl{sub 3}, LiCl. We have established that the complexation is the same in dilute HCl solutions but in concentrated solutions the trivalent actinides are more complexed. This difference is sharper in LiCl solutions. We also proposed the different models of complex in these solutions. (author) [French] Le but de ce travail est de comparer les transuraniens et lanthanides trivalents au point de vue de leur complexation en solution chlorhydrique. Nous avons ete amenes tout d'abord a etudier la solvatation de ces cations non complexes. C'est ainsi que nous pouvons constater une difference entre Am, Cm et les lanthanides. Ces derniers pouvant se separer en lanthanides legers et lanthanides lourds. Pour etudier la complexation nous avons utilise l'electrophorese sur papier apres avoir donne une theorie simple des mobilites en milieu complexant. Apres avoir etudie et compare l'hydrolyse de ces divers cations en solution chlorhydrique, nous avons etudie leur complexation avec l'ion Cl{sup -} dans dans divers milieux: HCl, NH{sub 4}Cl, CaCl{sub 2}, CeCl{sub 3}, LiCl. ous avons note qu'en solution HCl les deux series se comportent de la meme facon pour des concentrations faibles en Cl{sup -} mais que les transuraniens se complexent plus fortement dans les solutions concentrees. Cette difference s'accroit encore dans les milieux

Spectrophotometric investigation of the hetero-association of Caffeine and thiazine dye in aqueous solution

Science.gov (United States)

Bolotin, P. A.; Baranovsky, S. F.; Evstigneev, M. P.

2006-06-01

The self-association of thiazine dye, Methylene Blue (MB), and its hetero-association with Caffeine (CAF), were studied in aqueous solution by means of spectrophotometry in the visible range of spectrum. Concentration and temperature dependences of molar absorption of the interacting molecules were used to analyse dynamic equilibrium in solution in terms of two-component model of molecular hetero-association. The magnitudes of equilibrium dimerization and hetero-association constants as well as thermodynamic parameters, enthalpy and entropy, were determined. The calculation of the fraction of different types of associates in the mixed solution, containing Methylene Blue and Caffeine, was done. It was concluded that the hetero-association of Methylene Blue and Caffeine molecules results in lower effective concentration of the dye in solution, which may account for the alteration of its biological activity.

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.

Amperometric Sensor for Detection of Chloride Ions†

Science.gov (United States)

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

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 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. PMID:27873832

Amperometric Sensor for Detection of Chloride Ions.

Science.gov (United States)

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

2008-09-15

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.

Potentiometric Determination of Free Chloride in Cement Paste – an ...

African Journals Online (AJOL)

... cement paste.16 The accuracy and reliability of this analytical technique has been checked against a certified reference material, Merck sodium chloride solution. Confidence levels (CL0.95), of 0.03 and relative standard deviations of 0.2 % for chloride were determined for ordinary Portland cement (OPC) chloride binding ...

Effect of halideions on the surface-enhanced Raman spectroscopy of methylene blue for borohydride-reduced silver colloid

International Nuclear Information System (INIS)

Dong Xiao; Gu Huaimin; Liu Fang

2011-01-01

The surface enhanced Raman scattering (SERS) spectrum of methylene blue (MB) was studied when adding a range of halideions to borohydride-reduced silver colloid. The halideions such as chloride, bromide and iodide were added as aggregating agents to study the effects of halideions on SERS spectroscopy of MB and observe which halideion gives the greatest enhancement for borohydride-reduced silver colloids. The SERS spectra of MB were also detected over a wide range of concentrations of halideions to find the optimum concentration of halideions for SERS enhancement. From the results of this study, the intensity of SERS signal of MB was enhanced significantly when adding halideions to the colloid. Among the three kinds of halideions, chloride gives the greatest enhancement on SERS signal. The enhancement factors for MB with optimal concentration of chloride, bromide and iodide are 3.44x10 4 , 2.04x10 4 , and 1.0x10 4 , respectively. The differences of the SERS spectra of MB when adding different kinds and concentrations of halideions to the colloid may be attributed to the both effects of extent of aggregation of the colloid and the modification of silver surface chemistry. The purpose of this study is to further investigate the effect of halideions on borohydride-reduced silver colloid and to make the experimental conditions suitable for detecting some analytes in high efficiency on rational principles.

Electrodeposition behavior of nickel and nickel-zinc alloys from the zinc chloride-1-ethyl-3-methylimidazolium chloride low temperature molten salt

International Nuclear Information System (INIS)

Gou Shiping; Sun, I.-W.

2008-01-01

The electrodeposition of nickel and nickel-zinc alloys was investigated at polycrystalline tungsten electrode in the zinc chloride-1-ethyl-3-methylimidazolium chloride molten salt. Although nickel(II) chloride dissolved easily into the pure chloride-rich 1-ethyl-3-methylimidazolium chloride ionic melt, metallic nickel could not be obtained by electrochemical reduction of this solution. The addition of zinc chloride to this solution shifted the reduction of nickel(II) to more positive potential making the electrodeposition of nickel possible. The electrodeposition of nickel, however, requires an overpotential driven nucleation process. Dense and compact nickel deposits with good adherence could be prepared by controlling the deposition potential. X-ray powder diffraction measurements indicated the presence of crystalline nickel deposits. Non-anomalous electrodeposition of nickel-zinc alloys was achieved through the underpotential deposition of zinc on the deposited nickel at a potential more negative than that of the deposition of nickel. X-ray powder diffraction and energy-dispersive spectrometry measurements of the electrodeposits indicated that the composition and the phase types of the nickel-zinc alloys are dependent on the deposition potential. For the Ni-Zn alloy deposits prepared by underpotential deposition of Zn on Ni, the Zn content in the Ni-Zn was always less than 50 atom%

Uranium determination by spectrophotometry, in chloride solutions, using titanium (III) as reducer; Determinacao de uranio por espectrofotometria, em solucoes cloridricas, utilizando titanio (III) como redutor

Energy Technology Data Exchange (ETDEWEB)

Bastos, E T.R.; Bastos, M B.R.

1986-08-01

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.).

Redox reactions of methylene blue: a pulse radiolysis study

International Nuclear Information System (INIS)

Kishore, K.; Guha, S.N.; Mahadevan, J.; Moorthy, P.N.; Mittal, J.P.

1989-01-01

One-electron oxidation of methylene blue (MB - has been studied using specific oxidizing radicals such as Cl 2 - , Br 2 - , N 3 and Tl(II) in acidic and neutral aqueous solutions). The transient spectrum showed absorption maxima at 525 nm and 360 nm in the acidic pH region. At neutral pH also the absorption maxima were at 525 and 360 nm but the extinction coefficients were lower by 30%. A pK a of ∼4.3 was observed for the equilibrium MBH 3+ MB 2+ + H + . In the case of N 3 radical as the oxidant, the equilibrium: N 3 + MB = N 3 - + MB 2+ was observed for which an equilibrium constant of 120 was estimated from the experimental data. From this as well as from cyclic voltammetric experiments, the redox potential for the MB 2+ /MB + couple was calculated as 1.25 V vs NHE. The transient species produced by the reaction of OH radicals with methylene blue gave a very different spectrum with λ m = 400nm and a pK a of ∼ 8.6, and hence it is inferred that OH radicals do not bring about one-electron oxidation of the molecule. (author)

Chloride Ingress into Concrete under Water Pressure

DEFF Research Database (Denmark)

Lund, Mia Schou; Sander, Lotte Braad; Grelk, Bent

2011-01-01

The chloride ingress into concrete under water pressures of 100 kPa and 800 kPa have been investigated by experiments. The specimens were exposed to a 10% NaCl solution and water mixture. For the concrete having w/c = 0.35 the experimental results show the chloride diffusion coefficient at 800 k......Pa (～8 atm.) is 12 times greater than at 100 kPa (～1 atm.). For w/c = 0.45 and w/c = 0.55 the chloride diffusion coefficients are 7 and 3 times greater. This means that a change in pressure highly influences the chloride ingress into the concrete and thereby the life length models for concrete structures....

Temperature and sodium chloride effects on the solubility of anthracene in water

International Nuclear Information System (INIS)

Arias-Gonzalez, Israel; Reza, Joel; Trejo, Arturo

2010-01-01

The solubility of anthracene was measured in pure water and in sodium chloride aqueous solution (salt concentration, m/mol . kg -1 = 0.1006, 0.5056, and 0.6082) at temperatures between (278 and 333) K. Solubility of anthracene in pure water agrees fairly well with values reported in earlier similar studies. Solubility of anthracene in sodium chloride aqueous solutions ranged from (6 . 10 -8 to 143 . 10 -8 ) mol . kg -1 . Sodium chloride had a salting-out effect on the solubility of anthracene. The salting-out coefficients did not vary significantly with temperature over the range studied. The average salting-out coefficient for anthracene was 0.256 kg . mol -1 . The standard molar Gibbs free energies, Δ tr G o , enthalpies, Δ tr H o , and entropies, Δ tr S o , for the transfer of anthracene from pure water to sodium chloride aqueous solutions were also estimated. Most of the estimated Δ tr G o values were positive [(20 to 1230) J . mol -1 ]. The analysis of the thermodynamic parameters shows that the transfer of anthracene from pure water to sodium chloride aqueous solution is thermodynamically unfavorable, and that this unfavorable condition is caused by a decrease in entropy.

A boring solution

Energy Technology Data Exchange (ETDEWEB)

Radiuk, M I; Iushkova, N E; Kozubovskii, A I

1979-10-25

A boring solution is being patented for boring for oil and gas, which can be used in wells, where the temperature of the circulating liquid reaches 100/sup 0/. Polyvinyl acetate emulsion (PVE) is added for the purpose of decreasing viscosity of the solution at a temperature of agression into the boring solution containing clay, water, carboxymethylcellulose (CBC), a chloride from the number of sodium, potassium, or magnesium chlorides. The solution has the following composition in %: clay, 10 to 20; CBC, 1.5 to 2.0; chloride, 5 to 20; PVE, 0.5 to 2; water, up to 100. In accordance to GOST 1000-62 for the accepted PVE, the compound has the following composition, in %: monomer, 0.8; dry residue, greater than or equal to 50; plasticizer (tributyl phthalate), 5 to 15. The boring solution is processed according to the following method. The original solution, containing clay, water, salts, receives 1.5 to 2% CBC and afterwards it is processed with 0.5 to 2% PVE.

Models for the Immediate Environment of Ions in Aqueous Solutions of Neodymium Chloride

Science.gov (United States)

Smirnov, P. R.; Grechin, O. V.

2018-01-01

Radial distribution functions of neodymium chloride aqueous solutions in a wide range of concentrations under ambient conditions are calculated from experimental data obtained earlier via X-ray diffraction analysis. Different models of the structural organization of the system are developed. The optimum versions are determined by calculating theoretical functions for each model and comparing their fit to the experimental functions. Such quantitative characteristics of the immediate environment of Nd3+ and Cl- ions as coordination numbers, interparticle distances, and varieties of ion pairs are determined. It is shown that the average number of water molecules in the first coordination sphere of the cation falls from 9 to 6.2 as the concentration rises. The structure of the systems over the whole range of concentrations is determined by ion associates of the noncontact type.

Nitrate Removal from Aqueous Solutions Using Almond Charcoal Activated with Zinc Chloride

Directory of Open Access Journals (Sweden)

Mohsen Arbabi

2017-10-01

Full Text Available Background & Aims of the Study: Nitrate is one of the most important contaminants in aquatic environments that can leached to water resources from various sources such as sewage, fertilizers and decomposition of organic waste. Reduction of nitrate to nitrite in infant’s blood stream can cause “blue baby” disease in infants. The aim of this study was to evaluate the nitrate removal from aqueous solutions using modified almond charcoal with zinc chloride. Materials &Methods: This study is an experimental survey. At the first charcoal almond skins were prepared in 5500C and then modified with ZnCl2. Morphologies and characterization of almond shell charcoal were evaluated by using FTIR, EDX, BET and FESEM. Adsorption experiments were conducted with 500 ml sample in Becker. The nitrate concentration removal, contact time, pH and charcoal dosage were investigated. The central composite design method was used to optimizing the nitrate removal process. The results analyzed with ANOVA test. Results: The best condition founded in 48 min, 1250 ppm, 125 mg/l and 3 for retention time, primary nitrate concentration, charcoal dosage and pH respectively. The results showed that the nitrate removal decreases with increasing pH. Modification of skin charcoal is show increasing of nitrate removal from aquatic solution. Conclusion: In this study, the maximum nitrate removal efficiency for raw charcoal and modified charcoal was determined 15.47% and 62.78%, respectively. The results showed that this method can be used as an effective method for removing nitrate from aqueous solutions.

On solubility of rare earth chlorides in water at different temperatures

International Nuclear Information System (INIS)

Nikolaev, A.V.; Sorokina, A.A.; Sokolova, N.P.; Kotlyar-Shapirov, G.S.; Bagryantseva, L.I.

1978-01-01

Solubility of rare earth chlorides at -5, -10 and -15 deg C is studied. Rare earth chloride solubility dependences on the temperature in the interval from -15 to 50 deg C are presented. Decrease of solubility temperature coefficient to a zero is observed at temperature drop almost for all rare earth chlorides. Solubility temperature coefficient at the same temperature but for different rare earth chlorides reduces appreciably with the growth of rare earth chloride serial number. This testifies to the corresponding decrease of integral solution heat of rare earth chloride crystallohydrates

Ag-ligand modified tungstovandates and their efficient catalysis degradation properties for methylene blue

Energy Technology Data Exchange (ETDEWEB)

Zheng, Ran; Zhang, Huixia; Liu, Yunping; Wang, Xiaoxiao; Han, Zhangang, E-mail: hanzg116@126.com

2017-02-15

Two polytungstovandates [Ag(mbpy){sub 2}][Ag{sub 2}(mbpy){sub 3}][VW{sub 5}O{sub 19}]·H{sub 2}O (1) and [Ag(mbpy)]{sub 2}[Ag(mbpy){sub 2}]{sub 4}[VW{sub 12}O{sub 40}] (2) (mbpy =4,4′-dimethyl-2,2′-bipyridyl), had been hydrothermally synthesized and characterized by IR, TG, and single-crystal X-ray diffraction techniques. Single-crystal structural analysis revealed that the polyanionic clusters in two compounds are different: Lindqvist-type in 1 and α-Keggin-type in 2, respectively, while the cationic moieties in them are Ag-mbpy units. The experiments showed that this kind of hybrid crystal materials possesses more efficiently catalytic performance for the degradation of organic dye methylene blue (MB) in water solution under the UV irradiation. The significant degradation rate of MB can reach 89.9%, 94.9% by crystals 1 and 2 (40 mg) in the course of about 5 min. - Graphical abstract: Two Ag-ligand modified polytungstovandates had been synthesized and characterized, which were active in the catalytic degradation of organic dye methylene blue under the UV irradiation. - Highlights: • Two Ag-ligand modified tungstovandates were synthesized and characterized. • Weak interactions play important roles in constructing crystal frameworks. • Compounds are active to catalyze the degradation of methylene blue.

Effect of Dissolved Oxygen and Immersion Time on the Corrosion Behaviour of Mild Steel in Bicarbonate/Chloride Solution

Directory of Open Access Journals (Sweden)

Gaius Debi Eyu

2016-09-01

Full Text Available The electrochemical behavior of mild steel in bicarbonate solution at different dissolved oxygen (DO concentrations and immersion times has been studied under dynamic conditions using electrochemical techniques. The results show that both DO and immersion times influence the morphology of the corrosion products. In comparative tests, the corrosion rate was systematically found to be lower in solutions with lower DO, lower HCO3− concentrations and longer immersion time. The SEM analyses reveal that the iron dissolution rate was more severe in solutions containing higher DO. The decrease in corrosion rate can be attributed to the formation of a passive layer containing mainly α -FeO (OH and ( γ -Fe2O3/Fe3O4 as confirmed by the X-ray diffractometry (XRD and X-ray photoelectron spectroscopy (XPS. Passivation of mild steel is evident in electrochemical test at ≈ −600 mVSCE at pH ≥ 8 in dearated ( ≤ 0.8 ppm DO chloride bicarbonate solution under dynamic conditions.

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.

Mechanisms of bands and spirals formation during the drying of watery solutions of mercury (II) chloride with agar-agar

International Nuclear Information System (INIS)

Suarez-DomInguez, Edgardo Jonathan; Betancourt-Mar, Juvencio Alberto

2005-01-01

It is proposed two mechanisms to explain the formation of periodic and non periodic bands and spirals as thin films of gelatinous aqueous solutions of mercury (II) chloride are dried. The first mechanism supposes an homogeneous drying, where the height of the film decreases at constant rate, forming Liesegang bands. The second mechanism implies a non homogeneous drying where an evaporation front drives the formation of periodic bands and spirals

Application of potato (Solanum tuberosum plant wastes for the removal of methylene blue and malachite green dye from aqueous solution

Directory of Open Access Journals (Sweden)

Neha Gupta

2016-09-01

Full Text Available Dye pollutants from the textile, paper, and leather industries are important sources of environmental contamination. In the present study an agricultural waste from potato plant (potato stem powder, PSP and potato leaves powder, PLP was used as an adsorbent for removal of the methylene blue (MB and malachite green (MG dyes from aqueous solution. The adsorbent materials were characterized by scanning electron microscope (SEM and Fourier transform infrared (FTIR spectroscopy. Batch experiments were performed to investigate the effect of physico-chemical parameters, such as pHpzc, ionic strength, adsorbent dose, contact time, initial dyes concentration and temperature. The kinetics of adsorption was studied by applying the pseudo-first order, pseudo-second order and intraparticle diffusion models. The pseudo-second order model better represented the adsorption kinetics and the mechanism was controlled by surface adsorption and intraparticle diffusion. Equilibrium data were analyzed using Langmuir and Freundlich isotherm models. The thermodynamic parameters such as change in enthalpy (ΔH°, entropy (ΔS° and Gibb’s free energy (ΔG° of adsorption systems were also determined and evaluated.

Osmoregulated Chloride Currents in Hemocytes from Mytilus galloprovincialis.

Directory of Open Access Journals (Sweden)

Monica Bregante

Full Text Available We investigated the biophysical properties of the transport mediated by ion channels in hemocytes from the hemolymph of the bivalve Mytilus galloprovincialis. Besides other transporters, mytilus hemocytes possess a specialized channel sensitive to the osmotic pressure with functional properties similar to those of other transport proteins present in vertebrates. As chloride fluxes may play an important role in the regulation of cell volume in case of modifications of the ionic composition of the external medium, we focused our attention on an inwardly-rectifying voltage-dependent, chloride-selective channel activated by negative membrane potentials and potentiated by the low osmolality of the external solution. The chloride channel was slightly inhibited by micromolar concentrations of zinc chloride in the bath solution, while the antifouling agent zinc pyrithione did not affect the channel conductance at all. This is the first direct electrophysiological characterization of a functional ion channel in ancestral immunocytes of mytilus, which may bring a contribution to the understanding of the response of bivalves to salt and contaminant stresses.

Performance of Potassium Bicarbonate and Calcium Chloride Draw Solutions for Desalination of Saline Water Using Forward Osmosis

Directory of Open Access Journals (Sweden)

M. Nematzadeh

2015-01-01

Full Text Available Forward osmosis (FO has recently drawn attention as a promising membrane based method for seawater and brackish water desalination. In this study, we focus on the use of calciun chloride (CaCl2 and potassium bicarbonate (KHCO3 as inorganic salt draw solution candidates due to their appropriate performance in water flux and reverse salt diffusion as well as reasonable cost. The experiments were carried at 25 °C and cross-flow rate of 3 L min−1.  At the same osmotic pressure, the water flux of CaCl2 draw solution tested against deionized feed water, showed 20% higher permeation than KHCO3, which it was attributed to the lower internal concentration polarization (ICP. The reverse diffusion of CaCl2 was found higher than KHCO3 solution which it would be related to the smaller ionic size and the higher permeation of this salt through the membrane. The water flux for both draw solutions against 0.33 M NaCl feed solution was about 2.8 times lower than deionized feed water because of ICP. Higher concentrations of draw solution is required for increasing the water permeation from saline water feed towards the draw side.

Intensity of f-f bands of neodymium chloride alcohol solvates

International Nuclear Information System (INIS)

Bukietynska, K.; Jezowski-Trzebiatowska, B.; Keller, B.

1981-01-01

Recent results revealed that in alcohol solutions of lanthanide chlorides, at least in the case of Eu 3+ and Yb 3+ ions, there exist mixed solvates, i.e. both chloride ions and solvent molecules are present in the Ln 3+ ion first coordination sphere. This conclusion was drawn from an analysis of the charge transfer transitions in the spectra of Eu 3+ and Yb 3+ chlorides in alcohols (methyl, ethyl, n-propyl), where two separate C.T.bands were observed and identified as C.T. transitions from the alcohol molecule and chloride ion to the Ln 3+ ion. In our previous paper we have reported that the energy of the first f-d transition in the Pr 3+ chloride alcohol solvates varied for different alcohols. These data also confirmed our suggestion that alcohol molecules are present in the first coordination sphere of the lanthanide ion. In the work reported here, we have tried to apply the intensity analysis method to the solution spectra of neodymium chloride dissolved in simple aliphatic alcohols like methanol, ethanol and n-propanol. Experimental details are given. Results are presented and discussed. (author)

Physicochemical properties of the electrolyte system lithium tetrachloraluminate(III)-thionyl chloride

Energy Technology Data Exchange (ETDEWEB)

Demakhin, A.G.; Kuznetsov, N.N.

1992-07-20

The solubility of lithium chloroaluminate in thionyl chloride has been determined over the temperature range 233-323 K. The composition of solid phases in equilibrium with saturated solution was found. The density, viscosity, and electrical conductance of lithium chloroaluminate solutions in thionyl chloride were determined over the temperature range 263-333 K and pseudomolar volumes of the solution and apparent molar volumes of the electrolyte calculated. Activation energies for viscous flow and conductance have been calculated. 12 refs., 5 figs., 1 tab.

Temperature and sodium chloride effects on the solubility of anthracene in water

Energy Technology Data Exchange (ETDEWEB)

Arias-Gonzalez, Israel [Instituto Mexicano del Petroleo, Direccion de Investigacion y Posgrado, Programa de Ingenieria Molecular, Area de Investigacion en Termofisica, Eje Central Lazaro Cardenas Norte 152. 07730, Mexico D.F. (Mexico); Reza, Joel, E-mail: jreza@imp.m [Instituto Mexicano del Petroleo, Direccion de Investigacion y Posgrado, Programa de Ingenieria Molecular, Area de Investigacion en Termofisica, Eje Central Lazaro Cardenas Norte 152. 07730, Mexico D.F. (Mexico); Trejo, Arturo, E-mail: atrejo@imp.m [Instituto Mexicano del Petroleo, Direccion de Investigacion y Posgrado, Programa de Ingenieria Molecular, Area de Investigacion en Termofisica, Eje Central Lazaro Cardenas Norte 152. 07730, Mexico D.F. (Mexico)

2010-11-15

The solubility of anthracene was measured in pure water and in sodium chloride aqueous solution (salt concentration, m/mol . kg{sup -1} = 0.1006, 0.5056, and 0.6082) at temperatures between (278 and 333) K. Solubility of anthracene in pure water agrees fairly well with values reported in earlier similar studies. Solubility of anthracene in sodium chloride aqueous solutions ranged from (6 . 10{sup -8} to 143 . 10{sup -8}) mol . kg{sup -1}. Sodium chloride had a salting-out effect on the solubility of anthracene. The salting-out coefficients did not vary significantly with temperature over the range studied. The average salting-out coefficient for anthracene was 0.256 kg . mol{sup -1}. The standard molar Gibbs free energies, {Delta}{sub tr}G{sup o}, enthalpies, {Delta}{sub tr}H{sup o}, and entropies, {Delta}{sub tr}S{sup o}, for the transfer of anthracene from pure water to sodium chloride aqueous solutions were also estimated. Most of the estimated {Delta}{sub tr}G{sup o} values were positive [(20 to 1230) J . mol{sup -1}]. The analysis of the thermodynamic parameters shows that the transfer of anthracene from pure water to sodium chloride aqueous solution is thermodynamically unfavorable, and that this unfavorable condition is caused by a decrease in entropy.

A study on the cementation of Cu, Ni and Co ions with Mn powders in chloride solution

Energy Technology Data Exchange (ETDEWEB)

Ahn, Jae-Woo [Daejin University, Pochun-gun(Korea); Ahn, Jong-Gwan [Korea Univ., Seoul(Korea); Park, Kyung-Ho [Korea Institute of Geology Mining and Materials, Taejeon (Korea)

2000-06-30

A study on the cementation for the recovery of Cu, Ni and Co with Mn metallic powders in leaching solution from the manganese nodule that have removed Fe ions was studied. The results showed that the recovery efficiencies of metal ions with Mn powders increased when the temperature, pH and the concentration of chloride ions were increased in mixed solution. And the recovery efficiencies of Cu was 98% and not changed with the addition amounts of Mn powders but, in case of Co and Ni, the recovery efficiencies were increased with the addition amounts. The particle size of precipitate was about 5 {mu}m. From the results of experiment we proposed the two-step cementation process for the recovery of Cu, Ni and Co with Mn powders. (author). 9 refs., 4 tabs., 14 figs.

A nuclear magnetic relaxation study on internal motion of polyelectrolytes in solution

International Nuclear Information System (INIS)

Schriever, J.

1977-01-01

The aim of this thesis is to investigate the significance and the amount of information which can be extracted from the study of frequency dependence of magnetic relaxation rates in solutions of a synthetic macromolecule. Solutions of poly(methacrylic acid), PMA, in water were chosen as the object of the present work. A short survey of nuclear magnetic relaxation in solutions of simple macromolecules is presented. Results obtained by continuous wave experiments on PMA solutions are shown (viz. the information about the transverse relaxation from line width analysis of 60 MHz proton spectra). Water enriched in 17 O is used in magnetic relaxation studies; the results of the determination of hydrogen lifetimes in aqueous solutions of acetic acid and poly(methacrylic acid) are given. The possibility of obtaining information about the dynamics of deuterons in the acid side groups of weak polyacids by measuring deuteron relaxation in heavy water solutions of those acids is considered. The use of deuteron relaxation rate experiments on solutions of selectively methylene deuterated poly(methacrylic acid), [-CD 2 -CCH 3 COOH-]n, is demonstrated and the backbone methylene C-atom motion is charachterized. The magne-tic relaxation of nuclei in the side groups of methylene deuterated PMA, viz. protons in the methyland deuterons in the acid side groups is presented

Stability of 2 mg/mL Adenosine Solution in Polyvinyl Chloride and Polyolefin Infusion Bags.

Science.gov (United States)

DeAngelis, Michael; Ferrara, Alexander; Gregory, Kaleigh; Zammit, Kimberly; Zhao, Fang

2018-04-01

Adenosine is a potent endogenous mediator of vasodilation. Compounded sterile solutions of adenosine are used in cardiac catheterization lab to perform stress tests on the heart. These tests are used to determine the fractional flow reserve (FFR) and are commonly used in the management and diagnosis of cardiovascular conditions. The purpose of this study was to assess the physical and chemical stability of 2 mg/mL adenosine in 0.9% Sodium Chloride Injection, USP in polyvinyl chloride [PVC]) and polyolefin infusion bags stored at room temperature (20°C-25°C) and under refrigeration (2°C-8°C). The compounding and analytical methods used in this study were very similar to those described in the prior publications from the authors' laboratory. To ensure a uniform starting concentration of all stability samples, a batch of 2 mg/mL adenosine solution was prepared and then packaged into empty PVC and polyolefin infusion bags. These stability samples were prepared in triplicate for each bag type and storage temperature (a total of 12 samples). The infusion bag samples were assessed for stability immediately after preparation and after 1 day, 3 days, 7 days, and 14 days. At each time point, the infusion bags were first visually inspected against a light background for color change, clarity, and particulates. Aliquots were drawn from each sample at each time point for pH analysis and high-performance liquid chromatography (HPLC) analysis. Over 14 days of storage at room temperature or refrigeration, no considerable change in visual appearance or pH was observed in any bags. All samples retained 90% to 110% of the initial drug concentration. No significant degradation peaks were observed in the HPLC chromatograms.

Silkworm exuviae-A new non-conventional and low-cost adsorbent for removal of methylene blue from aqueous solutions

International Nuclear Information System (INIS)

Chen Hao; Zhao Jie; Dai Guoliang

2011-01-01

In this paper, silkworm exuviae (SE) waste, an agricultural waste available in large quantity in China, was utilized as low-cost adsorbent to remove basic dye (methylene blue, MB) from aqueous solution by adsorption. Kinetic data and sorption equilibrium isotherms were carried out in batch process. The adsorption kinetic experiments revealed that MB adsorption onto SE for different initial dye concentrations all followed pseudo-second order kinetics and were mainly controlled by the film diffusion mechanism. Batch equilibrium results at different temperatures suggest that MB adsorption onto SE can be described perfectly with Freundlich isotherm model compared with Langmuir and D-R isotherm models, and the characteristic parameters for each adsorption isotherm were also determined. Thermodynamic parameters calculated show the adsorption process has been found to be endothermic in nature. The analysis for the values of the mean free energies of adsorption (E a ), the Gibbs free energy (ΔG 0 ) and the effect of ionic strength all demonstrate that the whole adsorption process is mainly dominated by ion-exchange mechanism, which has also been verified by variations in FT-IR spectra and pH value before and after adsorption and desorption studies. The results reveal that SE can be employed as a low-cost alternative to other adsorbents for MB adsorption.

Effects of pH and chloride concentration on pitting corrosion of AA6061 aluminum alloy

International Nuclear Information System (INIS)

Zaid, B.; Saidi, D.; Benzaid, A.; Hadji, S.

2008-01-01

Effects of pH solution and chloride (Cl - ) 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 pit and corrosion E 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)

Activation energy of tracer-diffusion of manganese ions (Mn2+) in alkali metal chloride solutions

International Nuclear Information System (INIS)

Borhade, A.V.

2000-01-01

The activation energy of the tracer diffusion of Mn 2+ ions in alkali chloride solutions (0.1M) has been determined in agar gel medium (1-2.5%) over the temperature range of 25 - 45 deg C. The decrease in the value of the Arrhenius parameters, E and D 0 , with gel percentage is explained on the basis of the transition state theory. Further, the activation energy as a function of electrolyte concentration is also investigated using 1% agar gel in the temperature range of 25 - 45 deg C. In both the cases, the activation energies are determined by the least square fitting of the diffusion coefficient data obtained at various temperatures through the Arrhenius plots. (author)

Use of ZnO:Mn particles for degradation of methylene blue by photocatalysis process

International Nuclear Information System (INIS)

Giraldi, T. R.; Swerts, J. P.; Vicente, M. A.; Paris, E.C.; Ribeiro, C.

2016-01-01

The management of water use in the agricultural environment is a key factor to build new environmentally sustainable productive methods. Photocatalysis is a promising method for water decontamination. This research paper aimed to evaluate the photocatalytic potential of pure and Mn-doped ZnO particles. The materials were obtained by the polymeric precursor method, and characterized by X-ray diffraction, N_2 adsorption in low temperature, infrared and ultraviolet spectroscopy, and photoluminescence. In order to evaluate ZnO:Mn particles photo efficiency, experiments were carried out by applying the methylene blue dye solution to photodegradation under UVC exposure. The particles had ZnO single-phase, but low specific surface area. The sample ZnO:0.25% Mn presented higher efficiency in the methylene blue photocatalytic degradation test. This efficiency was related to a higher band gap energy value and a lower rate of electron recombination, which allows greater formation of hydroxyl radicals, which are responsible for dye degradation. (author)

Kinetics analysis for development of a rate constant estimation model for ultrasonic degradation reaction of methylene blue.

Science.gov (United States)

Kobayashi, Daisuke; Honma, Chiemi; Matsumoto, Hideyuki; Takahashi, Tomoki; Kuroda, Chiaki; Otake, Katsuto; Shono, Atsushi

2014-07-01

Ultrasound has been used as an advanced oxidation method for wastewater treatment. Sonochemical degradation of organic compounds in aqueous solution occurs by pyrolysis and/or reaction with hydroxyl radicals. Moreover, kinetics of sonochemical degradation has been proposed. However, the effect of ultrasonic frequency on degradation rate has not been investigated. In our previous study, a simple model for estimating the apparent degradation rate of methylene blue was proposed. In this study, sonochemical degradation of methylene blue was performed at various frequencies. Apparent degradation rate constant was evaluated assuming that sonochemical degradation of methylene blue was a first-order reaction. Specifically, we focused on effects of ultrasonic frequency and power on rate constant, and the applicability of our proposed model was demonstrated. Using this approach, maximum sonochemical degradation rate was observed at 490 kHz, which agrees with a previous investigation into the effect of frequency on the sonochemical efficiency value evaluated by KI oxidation dosimetry. Degradation rate increased with ultrasonic power at every frequency. It was also observed that threshold power must be reached for the degradation reaction to progress. The initial methylene blue concentration and the apparent degradation rate constant have a relation of an inverse proportion. Our proposed model for estimating the apparent degradation rate constant using ultrasonic power and sonochemical efficiency value can apply to this study which extended the frequency and initial concentration range. Copyright © 2013 Elsevier B.V. All rights reserved.

Stress corrosion cracking of Inconel 600 in aqueous solutions at elevated temperature. Pt. II. Effects of chloride and sulphate ions on the electrochemical behaviour of Inconel 600

International Nuclear Information System (INIS)

Ashour, E.A.; Schneider, F.; Mummert, K.

1997-01-01

For pt.I see ibid., p.151-6, 1997. The influencing effects of temperature, potential and electrolyte composition on the electrochemical behaviour of Inconel 600 in aqueous solutions are presented. Considering these effects the connection between the data have been obtained from chemo-mechanical fracture investigation on CT-samples in Part I of this paper and pitting corrosion are discussed. The results have shown that chloride ions depassivate the surfaces of cracks locally and hinder the formation of a new protective oxide layer on the fracture surfaces. Furthermore, chloride promotes the dissolution of metal and initiates the cracking, respectively. The resulting crevice corrosion promotes an increase of hydrogen absorption by the metal. The increase of the hydrogen content of the metal influences the mechanical fracture behaviour. Contrary, sulphate ions inhibit the initiation of corrosion mainly due to a hinderance of chloride ions adsorption on active sites of the fracture surfaces. The initiation of localized corrosion in the crevice region may be stimulated by chromate ions formed by oxidation of chromium from the oxide layer or the base metal in oxygen containing solutions. (orig.)

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)

Jegle, U.

1989-02-01

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) [de

Modified methylene blue injection improves lymph node harvest in rectal cancer.

Science.gov (United States)

Liu, Jianpei; Huang, Pinjie; Zheng, Zongheng; Chen, Tufeng; Wei, Hongbo

2017-04-01

The presence of nodal metastases in rectal cancer plays an important role in accurate staging and prognosis, which depends on adequate lymph node harvest. The aim of this prospective study is to investigate the feasibility and survival benefit of improving lymph node harvest by a modified method with methylene blue injection in rectal cancer specimens. One hundred and thirty-one patients with rectal cancer were randomly assigned to the control group in which lymph nodes were harvested by palpation and sight, or to the methylene blue group using a modified method of injection into the superior rectal artery with methylene blue. Analysis of clinicopathologic records, including a long-term follow-up, was performed. In the methylene blue group, 678 lymph nodes were harvested by simple palpation and sight. Methylene blue injection added 853 lymph nodes to the total harvest as well as 32 additional metastatic lymph nodes, causing a shift to node-positive stage in four patients. The average number of lymph nodes harvested was 11.7 ± 3.4 in the control group and 23.2 ± 4.7 in the methylene blue group, respectively. The harvest of small lymph nodes (rectal cancer, especially small node and metastatic node retrieval, which provided more accurate staging. However, it was not associated with overall survival. © 2014 Royal Australasian College of Surgeons.

Preparation of robust braid-reinforced poly(vinyl chloride) ultrafiltration hollow fiber membrane with antifouling surface and application to filtration of activated sludge solution.

Science.gov (United States)

Zhou, Zhuang; Rajabzadeh, Saeid; Fang, Lifeng; Miyoshi, Taro; Kakihana, Yuriko; Matsuyama, Hideto

2017-08-01

Braid-reinforced hollow fiber membranes with high mechanical properties and considerable antifouling surface were prepared by blending poly(vinyl chloride) (PVC) with poly(vinyl chloride-co-poly(ethylene glycol) methyl ether methacrylate) (poly(VC-co-PEGMA)) copolymer via non-solvent induced phase separation (NIPS). The tensile strength of the braid-reinforced PVC hollow fiber membranes were significantly larger than those of previously reported various types of PVC hollow fiber membranes. The high interfacial bonding strength indicated the good compatibility between the coating materials and the surface of polyethylene terephthalate (PET)-braid. Owing to the surface segregation phenomena, the membrane surface PEGMA coverage increased upon increasing the poly(VC-co-PEGMA)/PVC blending ratio, resulting in higher hydrophilicities and bovine serum albumin (BSA) repulsion. To compare the fouling properties, membranes with similar PWPs were prepared by adjusting the dope solution composition to eliminate the effect of hydrodynamic conditions on the membrane fouling performance. The blend membranes surface exhibited considerable fouling resistance to the molecular adsorption from both BSA solution and activated sludge solution. In both cases, the flux recovered to almost 80% of the initial flux using only water backflush. Considering their great mechanical properties and antifouling resistance to activated sludge solution, these novel membranes show good potential for application in wastewater treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

Reinforcement corrosion in alkaline chloride media with reduced oxygen concentrations

International Nuclear Information System (INIS)

Andrade, C.; Fullea, J.; Toro, L.; Martinez, I.; Rebolledo, N.

2013-01-01

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)

Application of a genetic algorithm in the conformational analysis of methylene-acetal-linked thymine dimers in DNA: Comparison with distance geometry calculations

International Nuclear Information System (INIS)

Beckers, Mischa L.M.; Buydens, Lutgarde M.C.; Pikkemaat, Jeroen A.; Altona, Cornelis

1997-01-01

The three-dimensional spatial structure of a methylene-acetal-linked thymine dimer present in a 10 base-pair (bp) sense-antisense DNA duplex was studied with a genetic algorithm designed to interpret NOE distance restraints. Trial solutions were represented by torsion angles. This means that bond angles for the dimer trial structures are kept fixed during the genetic algorithm optimization. Bond angle values were extracted from a 10 bp sense-antisense duplex model that was subjected to energy minimization by means of a modified AMBER force field. A set of 63 proton-proton distance restraints defining the methylene-acetal-linked thymine dimer was available. The genetic algorithm minimizes the difference between distances in the trial structures and distance restraints. A large conformational search space could be covered in the genetic algorithm optimization by allowing a wide range of torsion angles. The genetic algorithm optimization in all cases led to one family of structures. This family of the methylene-acetal-linked thymine dimer in the duplex differs from the family that was suggested from distance geometry calculations. It is demonstrated that the bond angle geometry around the methylene-acetal linkage plays an important role in the optimization

Corrosion of Cu-xZn alloys in slightly alkaline chloride solutions studied by stripping voltammetry and microanalysis.

Science.gov (United States)

Milosev, I; Minović, A

2001-01-01

The mechanism of corrosion of Cu-xZn alloys (x = 10-40 wt %) in slightly alkaline chloride solutions was investigated by analysing solid reaction products by energy dispersive X-ray analysis (EDS) and dissolved reaction products by differential anodic pulse stripping (DAPS) voltammetry. The corrosion process was studied under open circuit and under potentiostatic conditions at selected potentials. Pure metals were studied comparatively so that an interacting effect of particular metal components in the alloy could be determined. All four Cu-xZn alloys show an improved behaviour compared to pure metals. Under open-circuit condition both components dissolve simultaneously in the solution. With increasing immersion time the preferential, dissolution of zinc in the solution becomes pronounced. It is the highest for Cu-10Zn and the lowest for Cu-30Zn alloy. Under potentiostatic control the dissolution mechanism depends on the electrode potential and changes from exclusive dissolution of zinc to simultaneous dissolution of both components with preferential dissolution of zinc. The latter decreases, as the electrode potential becomes more positive.

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)

Ghasemian, Ensieh; Najafi, Mojgan; Rafati, Amir Abbas; Felegari, Zahra

2010-01-01

Surface and bulk properties of 1-hexyl-3-methylimidazolium chloride [C 6 mim][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 (A min ) 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 [C 6 mim][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.

Pyrite-enhanced methylene blue degradation in non-thermal plasma water treatment reactor

Energy Technology Data Exchange (ETDEWEB)

Benetoli, Luis Otavio de Brito, E-mail: luskywalcker@yahoo.com.br [Departamento de Quimica, Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil); Cadorin, Bruno Mena; Baldissarelli, Vanessa Zanon [Departamento de Quimica, Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil); Geremias, Reginaldo [Departamento de Ciencias Rurais, Universidade Federal de Santa Catarina (UFSC), Curitibanos, SC (Brazil); Goncalvez de Souza, Ivan [Departamento de Quimica, Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil); Debacher, Nito Angelo, E-mail: debacher@qmc.ufsc.br [Departamento de Quimica, Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil)

2012-10-30

Highlights: Black-Right-Pointing-Pointer We use O{sub 2} as the feed gas and pyrite was added to the non-thermal plasma reactor. Black-Right-Pointing-Pointer The methylene blue removal by NTP increased in the presence of pyrite. Black-Right-Pointing-Pointer The total organic carbon content decreased substantially. Black-Right-Pointing-Pointer The acute toxicity test showed that the treated solution is not toxic. Black-Right-Pointing-Pointer The dye degradation occurs via electron impact as well as successive hydroxylation. - Abstract: In this study, methylene blue (MB) removal from an aqueous phase by electrical discharge non-thermal plasma (NTP) over water was investigated using three different feed gases: N{sub 2}, Ar, and O{sub 2}. The results showed that the dye removal rate was not strongly dependent on the feed gas when the electrical current was kept the same for all gases. The hydrogen peroxide generation in the water varied according to the feed gas (N{sub 2} < Ar < O{sub 2}). Using O{sub 2} as the feed gas, pyrite was added to the reactor in acid medium resulting in an accentuated increase in the dye removal, which suggests that pyrite acts as a Fenton-like catalyst. The total organic carbon (TOC) content of the dye solution decreased slightly as the plasma treatment time increased, but in the presence of the pyrite catalyst the TOC removal increased substantially. The acute toxicity test using Artemia sp. microcrustaceans showed that the treated solution is not toxic when Ar, O{sub 2} or O{sub 2}-pyrite is employed. Electrospray ionization mass spectrometry analysis (ESI-MS) of the treated samples indicated that the dye degradation occurs via high energy electron impact as well as successive hydroxylation in the benzene rings of the dye molecules.

Kinetics and mechanism of oxidation of 1-hydroxymethyl-eta/sup 3/-allypalladium chloride by p-benzoquinone in aqueous solutions

Energy Technology Data Exchange (ETDEWEB)

Belov, A.P.; Kalabin, S.M.; Statsenko, O.N.

1988-03-01

/sup 1/H NMR spectroscopy was used to show that the primary product of the oxidation of the eta/sup 3/-allyl complex of palladium, (based on 1,3-butadiene-1-hydroxymethyl-eta/sup 3/-allylpalladium chloride), by the action of p-benzoquinone in acid aqueous solutions is 4-chloro-2-buten-1-o1. The reaction kinetics were studied colorimetrically. It was found that the rate of reaction is described by a kinetic equation of the second order (first with respect to each of the reagents). It was shown that the second order rate constant increases nonlinearly with increase in the concentration of the chloride ions and hydrogen ions, and tends to a constant value in the region of high concentrations of these ions. The values of the activation parameters and the isotopic kinetic effect were determined. The kinetic equation and the mechanism of the reaction studied were compared with those of the oxidation processes of unsubstituted eta/sup 3/-allyl complexes of palladium.

Photodegradation of indigo carmine and methylene blue dyes in aqueous solution by SiC-TiO{sub 2} catalysts prepared by sol-gel

Energy Technology Data Exchange (ETDEWEB)

Gomez-Solis, Christian [Facultad de Ciencias Quimicas, Universidad Autonoma de San Luis Potosi, San Luis Potosi Av. Manuel Nava 6, San Luis Potosi, S.L.P. 78290 (Mexico); Juarez-Ramirez, Isaias, E-mail: isajua13@yahoo.com [Departamento de Ecomateriales y Energia, Facultad de Ingenieria Civil, Universidad Autonoma de Nuevo Leon, Cd. Universitaria, San Nicolas de los Garza, Nuevo Leon 66450 (Mexico); Moctezuma, Edgar [Facultad de Ciencias Quimicas, Universidad Autonoma de San Luis Potosi, San Luis Potosi Av. Manuel Nava 6, San Luis Potosi, S.L.P. 78290 (Mexico); Torres-Martinez, Leticia M. [Departamento de Ecomateriales y Energia, Facultad de Ingenieria Civil, Universidad Autonoma de Nuevo Leon, Cd. Universitaria, San Nicolas de los Garza, Nuevo Leon 66450 (Mexico)

2012-05-30

Highlights: Black-Right-Pointing-Pointer Photodegradation of organic dyes is possible using sol-gel SiC-TiO{sub 2} catalysts. Black-Right-Pointing-Pointer SiC-TiO{sub 2} makes a synergy effect that enhances its catalytic activity. Black-Right-Pointing-Pointer Sol-gel allows good dispersion and attachment of TiO{sub 2} particles on SiC surface. Black-Right-Pointing-Pointer SiC-TiO{sub 2} exhibits better activity than TiO{sub 2} (P25) on organic dyes degradation. Black-Right-Pointing-Pointer SiC-TiO{sub 2} catalysts are settled down and easily separated after photocatalysis. - Abstract: Indigo carmine and methylene blue dyes in aqueous solution were photodegraded using SiC-TiO{sub 2} catalysts prepared by sol-gel method. After thermal treatment at 450 Degree-Sign C, SiC-TiO{sub 2} catalysts prepared in this work showed the presence of SiC and TiO{sub 2} anatase phase. Those compounds showed specific surface area values around 22-25 m{sup 2} g{sup -1}, and energy band gap values close to 3.05 eV. In comparison with TiO{sub 2} (P25), SiC-TiO{sub 2} catalysts showed the highest activity for indigo carmine and methylene blue degradation, but this activity cannot be attributed to the properties above mentioned. Therefore, photocatalytic performance is due to the synergy effect between SiC and TiO{sub 2} particles caused by the sol-gel method used to prepare the SiC-TiO{sub 2} catalysts. TiO{sub 2} nanoparticles are well dispersed onto SiC surface allowing the transfer of electronic charges between SiC and TiO{sub 2} semiconductors, which avoid the fast recombination of the electron-hole pair during the photocatalytic process.

Utilization of zeolites synthesized from coal ash for methylene blue removal from water

Directory of Open Access Journals (Sweden)

Denise Alves Fungaro

2008-12-01

Full Text Available The adsorption of methylene blue from aqueous solution was carried out using zeolites synthesized from coal ash as low-cost adsorbents. The coal ash sample was converted to zeolites by hydrothermal treatment using different synthesis parameters. The materials were characterized by physical-chemical analysis, XRD and SEM studies. The adsorption isotherms can be fitted by Freundlich model. The values of the adsorption capacity of adsorbents were similar for adsorbents. Kinetic studies indicate that the adsorption follows pseudo-second-order kinetic model.

Fast microwave-assisted green synthesis of xanthan gum grafted acrylic acid for enhanced methylene blue dye removal from aqueous solution.

Science.gov (United States)

Makhado, Edwin; Pandey, Sadanand; Nomngongo, Philiswa N; Ramontja, James

2017-11-15

In the present project, graft polymerization was employed to synthesis a novel adsorbent using acrylic acid (AA) and xanthan gum (XG) for cationic methylene dye (MB + ) removal from aqueous solution. The XG was rapidly grafted with acrylic acid (CH 2 =CHCOOH) under microwave heating. Fourier-transform infrared spectroscopy (FTIR), Proton Nuclear magnetic resonance spectroscopy ( 1 H NMR), scanning electron microscopy (SEM), X-ray diffraction (XRD) and Thermal gravimetric analysis (TGA) techniques were used to verify the adsorbent formed under optimized reaction conditions. Optimum reaction conditions [AA (0.4M), APS (0.05M), XG (2gL -1 ), MW power (100%), MW time (80s)] offer maximum %G and %GE of 484 and 78.3, respectively. The removal ratio of adsorbent to MB + reached to 92.8% at 100mgL -1 . Equilibrium and kinetic adsorptions of dyes were better explained by the Langmuir isotherm and pseudo second-order kinetic model respectively. The results demonstrate xanthan gum grafted polyacrylic acid (mw XG-g-PAA) absorbent had the universality for removal of dyes through the chemical adsorption mechanism. Copyright © 2017 Elsevier Ltd. All rights reserved.

Chloride Ingress in Chemically Activated Calcined Clay-Based Cement

Directory of Open Access Journals (Sweden)

Joseph Mwiti Marangu

2018-01-01

Full Text Available Chloride-laden environments pose serious durability concerns in cement based materials. This paper presents the findings of chloride ingress in chemically activated calcined Clay-Ordinary Portland Cement blended mortars. Results are also presented for compressive strength development and porosity tests. Sampled clays were incinerated at a temperature of 800°C for 4 hours. The resultant calcined clay was blended with Ordinary Portland Cement (OPC at replacement level of 35% by mass of OPC to make test cement labeled PCC35. Mortar prisms measuring 40 mm × 40 mm × 160 mm were cast using PCC35 with 0.5 M Na2SO4 solution as a chemical activator instead of water. Compressive strength was determined at 28th day of curing. As a control, OPC, Portland Pozzolana Cement (PPC, and PCC35 were similarly investigated without use of activator. After the 28th day of curing, mortar specimens were subjected to accelerated chloride ingress, porosity, compressive strength tests, and chloride profiling. Subsequently, apparent diffusion coefficients (Dapp were estimated from solutions to Fick’s second law of diffusion. Compressive strength increased after exposure to the chloride rich media in all cement categories. Chemically activated PCC35 exhibited higher compressive strength compared to nonactivated PCC35. However, chemically activated PCC35 had the least gain in compressive strength, lower porosity, and lower chloride ingress in terms of Dapp, compared to OPC, PPC, and nonactivated PCC35.

Removal of methylene blue from its aqueous solution by froth flotation: hydrophobic silica nanoparticle as a collector

Energy Technology Data Exchange (ETDEWEB)

Hu, Nan; Liu, Wei; Ding, Linlin; Wu, Zhaoliang, E-mail: zhaoliangwu-hebut@163.com; Yin, Hao; Huang, Di; Li, Hongzhen; Jin, Lixue; Zheng, Huijie [Hebei University of Technology, School of Chemical Engineering and Technology (China)

2017-02-15

Dye pollution has been a severe problem faced by worldwide environmentalists. The use of nanoparticles as adsorbents has attracted widespread interests for effectively removing dyes, while the separation of them from an aqueous solution is a difficult and important subject. For achieving the simultaneous removal of methylene blue (MB) and nanoadsorbents, this work utilized a commercial hydrophobic silica nanoparticle (SNP) (200.0 ± 10.0 nm in average particle size) as a collector and then developed a novel froth flotation technology without using any surfactants. Under the suitable conditions of anhydrous ethanol dosage of 8 mL, pH of 9.0, SNP concentration of 600 mg/L, and flotation column height of 600 mm, the removal efficiencies of MB and SNPs and the volume ratio reached 91.1 ± 4.6%, 93.9 ± 4.7%, and 10.5 ± 0.5, respectively. Subsequently, the recovered MB-adsorbed SNPs in the foamate were separated by free setting due to their high concentration and massive agglomeration. After free setting, MB could be effectively separated from the recovered MB-adsorbed SNPs by using ethanol at pH 2.0 and repeating five cycles of washing-centrifugation. Additionally, the regenerated SNPs could be reused for removing MB up to five times. Overall, this work had a significant meaning for the treatment of dye-contaminated wastewaters.

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

International Nuclear Information System (INIS)

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.

2003-01-01

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 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 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

Ocular toxicity of beta-blockers and benzalkonium chloride in pigmented rabbits: electrophysiological and morphological studies.

Science.gov (United States)

Chou, A; Hori, S; Takase, M

1985-01-01

Subconjunctival injection of 0.2 ml of the following solutions was carried out once a day for two weeks in the albino and pigmented rabbit: commercial 0.5% timolol or 1% befunolol ophthalmic solutions, both containing benzalkonium chloride, and also these drug solutions containing no preservative, ophthalmic base solutions containing benzalkonium chloride, physiological saline solution or phosphate buffer solution. One week after daily injections of the commercial drug solutions or base solutions with benzalkonium chloride, the electroretinogram (ERG) showed a marked reduction in the a- and b-wave amplitudes in the pigmented rabbit, but the ERG changes were slight in the albino rabbit. After two weeks of injections, histological studies of the pigmented rabbit eyes revealed retinal detachment, visual cell loss and atrophy of the retinal pigment epithelium and choroid; the changes in the albino rabbit eyes were minimal. Injections of the beta-blockers containing no benzalkonium resulted in no significant changes in the ERG or in the tissue structures of all rabbits. Injections of only physiological saline or phosphate buffer had no deleterious effects. Therefore, the ocular toxicity of the beta-blockers was thought to be minor and the toxic effects seen in this study were thought to be due to benzalkonium chloride, which possibly accumulates in the ocular pigments.

Recovery of soluble chloride salts from the wastewater generated during the washing process of municipal solid wastes incineration fly ash.

Science.gov (United States)

Tang, Hailong; Erzat, Aris; Liu, Yangsheng

2014-01-01

Water washing is widely used as the pretreatment method to treat municipal solid waste incineration fly ash, which facilitates the further solidification/stabilization treatment or resource recovery of the fly ash. The wastewater generated during the washing process is a kind of hydrosaline solution, usually containing high concentrations of alkali chlorides and sulphates, which cause serious pollution to environment. However, these salts can be recycled as resources instead of discharge. This paper explored an effective and practical recovery method to separate sodium chloride, potassium chloride, and calcium chloride salts individually from the hydrosaline water. In laboratory experiments, a simulating hydrosaline solution was prepared according to composition of the waste washing water. First, in the three-step evaporation-crystallization process, pure sodium chloride and solid mixture of sodium and potassium chlorides were obtained separately, and the remaining solution contained potassium and calcium chlorides (solution A). And then, the solid mixture was fully dissolved into water (solution B obtained). Finally, ethanol was added into solutions A and B to change the solubility of sodium, potassium, and calcium chlorides within the mixed solvent of water and ethanol. During the ethanol-adding precipitation process, each salt was separated individually, and the purity of the raw production in laboratory experiments reached about 90%. The ethanol can be recycled by distillation and reused as the solvent. Therefore, this technology may bring both environmental and economic benefits.

Stability of midazolam hydrochloride injection 1-mg/mL solutions in polyvinyl chloride and polyolefin bags.

Science.gov (United States)

Karlage, Kelly; Earhart, Zachary; Green-Boesen, Kelly; Myrdal, Paul B

2011-08-15

The stability of midazolam hydrochloride injection 1-mg/mL solutions in polyvinyl chloride (PVC) and polyolefin bags under varying conditions was evaluated. Triplicate solutions of midazolam hydrochloride 1-mg/mL were prepared in polyolefin and PVC i.v. bags by diluting midazolam hydrochloride injection 5 mg/mL with 5% dextrose injection. Bags were then stored under refrigeration (3-4 °C), exposed to light at room temperature (20-25 °C), or protected from light in amber bags at room temperature. Samples were taken immediately after preparation (day 0) and on days 1, 2, 3, 6, 13, 20, and 27 for analysis with a stability-indicating high-performance liquid chromatography assay in order to determine solution concentration. Stability was defined as retention of at least 90% of the initial drug concentration. The pH of each solution was also measured weekly. Sterility of the i.v. bags was determined at the end of the study by microbiological testing with culture in growth media. Differences in concentrations under the various storage conditions and bags used were analyzed using analysis of variance. All solutions retained over 98% of the initial midazolam hydrochloride concentration, with no statistically significant (p ≥ 0.05) change in concentration over the four-week period. Stability was not affected by temperature, exposure to light, or bag type. The pH of all solutions remained between 3.2 and 3.4 throughout the study. Sterility after 28 days was retained. Midazolam hydrochloride 1-mg/mL solutions diluted in 5% dextrose injection remained stable over 27 days in both polyolefin and PVC i.v. bags, regardless of storage condition.

Graphene oxide (rGO)-metal oxide (TiO2/Fe3O4) based nanocomposites for the removal of methylene blue

Science.gov (United States)

Banerjee, Soma; Benjwal, Poonam; Singh, Milan; Kar, Kamal K.

2018-05-01

Herein, ternary nanocomposites based on titanium dioxide, ferric oxide and reduced graphene oxide (GO) have been developed for photocatalytic degradation of methylene blue. The nanocomposites are prepared by simple sol-gel and wet assembly methods with varying weight ratio of each components to obtain efficient photocatalytic degradation. Due to the synergistic effect among the three components, a swift removal of methylene blue becomes possible under visible and UV light. The rGO-Fe3O4-TiO2 nanocomposite having composition 1:1:2 has achieved maximum degradation of methylene blue from the aqueous solution. About 99% of the dye has been removed within 6 min under UV irradiation, while in presence of visible light, 94% has been degraded from the wastewater. The enhancement of photocatalytic activity in this ternary system is attributed to the efficient separation of charge carriers from TiO2 to rGO under the exposure of light and the initiation of photo-Fenton reaction due to the incorporated Fe3O4 nanoparticles in presence of H2O2, which provides highly reactive hydroxyl ions that mineralize the pollutants. All these results indicate that these ternary nanocomposites possess great potential for both UV and visible light driven methylene blue destruction from the wastewater.

Indium-111-chloride and three-phase bone scintigraphy: A comparison for imaging experimental osteomyelitis

International Nuclear Information System (INIS)

Hoskinson, J.J.; Daniel, G.B.; Patton, C.S.

1991-01-01

To investigate the utility of indium-111-chloride ( 111 In-Cl) imaging in detecting osteomyelitis complicating surgical or fracture sites, the proximal tibia of 11 dogs were experimentally infected with Staphylococcus aureus after creation of a cortical defect. The contralateral limb served as a sham-operated control. Animals were serially imaged by radiography, three-phase technetium-99m-methylene diphosphonate (99mTc-MDP) scintigraphy, and 111 In-Cl scintigraphy. There was a significant difference between infected (1.93) and noninfected (1.32) limb's tibia/femur count density ratios on 24-hr (p = 0.0001) and 72-hr (p = 0.0001) 111 In-Cl images. A smaller difference was found for 99mTc-MDP bone-phase tibia/femur ratios (p = 0.0199). Using receiver operator characteristic analysis of tibia/femur ratios, a sensitivity of 61%, specificity of 88%, and positive (75%) and negative (79%) predictive values were determined for the 24-hr 111 In-Cl images. Indium-111-chloride was superior to 99mTc-MDP in differentiating infected and noninfected operative sites

3D Oxidized Graphene Frameworks: An Efficient Adsorbent for Methylene Blue

Science.gov (United States)

Pandey, Abhishek; Deb, Madhurima; Tiwari, Shreya; Pawar, Pranav Bhagwan; Saxena, Sumit; Shukla, Shobha

2018-04-01

Extraordinary properties of graphene and its derivatives have found application in varied areas such as energy, electronics, optical devices and sensors, to name a few. Large surface area along with specialized functional groups make these materials attractive for removal of dye molecules in solution via adsorption. Industrial effluents contain large amounts of toxic chemicals resulting in pollution of water bodies, which pose environmental hazards in general. Here we report application of 3D oxidized graphene frameworks in the efficient removal of cationic dye molecules such as methylene blue via adsorption. Systematic parametric studies investigating the effect of the initial dye concentration, pH and contact time have been performed. Spectroscopic analysis of the filtrate suggests that tortuous paths in 3D oxidized graphene frameworks result in efficient removal of dye molecules due to enhanced interaction. The hydroxyl groups retained in these 3D oxidized graphene frameworks facilitate adsorption of the dye molecules while passing through the adsorbent. pH studies suggest that maximum removal efficiency for methylene blue was achieved at pH value of 9. The results suggest that these 3D oxidized graphene frameworks can be used for purification of large volumes of contaminated water from cationic dyes in waste water treatment plants.

Process for the graft polymerization of polyvinyl chloride. [electron beams

Energy Technology Data Exchange (ETDEWEB)

Kageyama, E; Kusama, Y; Udagawa, A; Hashimoto, S

1970-08-14

The graft polymerization of acrylonitrile on polyvinyl chloride is effected by simultaneous irradiation with ionizing radiations in a reaction bath consisting of 30% acrylonitrile and 70% n-hexane. The acrylonitrile-hydrocarbon reaction bath increases the graft efficiency markedly when the content of acrylonitrile is 30%. In this case, the formation rate of acrylonitrile homopolymer decreases with a decrease in the content of acrylonitrile. The immersion time may be from a few minutes to a few hours, depending on the type, property and desired graft efficiency of the polyvinyl chloride resin. The polyvinyl chloride may be any available on the market. The acrylonitrile may contain a small quantity of copolymerizable monomer if it does not influence the thermal property of the polyvinyl chloride graft polymer. The ionizing radiations must have enough energy to form an ion pair by removing one electron from one atom of a gas. In examples, 10 g of polyvinyl chloride in powder form were immersed in 100 cc of a mixed solution consisting of 70% to 90% of n-hexane and 10% to 30% of acrylonitrile. The polyvinyl chloride in the solution was exposed to electron beams of 2 Mrad at a dose rate of 7.2 x 10/sup 7/ rad/hr. under a reduced pressure. The graft efficiency was 50% to 80% and the yield of acrylonitrile homopolymer was 0.42 g to 1.26 g.

A study on chloride induced depassivation of Fe-P-C-Si and Fe-P-C-Si-N steels in simulated concrete pore solution

Science.gov (United States)

Mehta, Yashwant; Chaudhari, Gajanan P.; Dabhade, Vikram V.

2018-03-01

The corrosion behaviour of high phosphorous steels containing varying amounts of silicon and nitrogen was studied by potentiodynamic polarization, linear polarization resistance (LPR) and electrochemical impedance spectroscopy (EIS) measurements. The morphology of a steel specimen tested in chloride containing concrete pore solution was studied using scanning electron microscope (SEM) and the elemental distribution at the pitting corrosion area was investigated using electron dispersive spectroscopy (EDS). The results showed that the capacitance increased and resistance declined with immersion time in Ca(OH)2 solution containing 0.1% chloride for plain carbon steel. The opposite was observed in the case of the high phosphorous steels. The potentiodynamic polarization and LPR results complement the EIS findings. Corrosion behaviour could be described with an equivalent circuit having two time constants. The creation, expansion and degradation of the passive layer were discussed with the help of the equivalent circuit elements. The SEM-EDS studies revealed that MnS inclusions at the surface could have a role in the initiation and growth of pits and that phosphorous was present at the pit free surface of the steel.

Formation of mixed hydroxides in the thorium chloride-iron chloride-sodium hydroxide system

International Nuclear Information System (INIS)

Krivokhatskij, A.S.; Prokudina, A.F.; Sapozhnikova, T.V.

1976-01-01

The process of formation of mixed hydroxides in the system thorium chloride-iron chloride-NaOH was studied at commensurate concentrations of Th and Fe in solution (1:1 and 1:10 mole fractions, respectively) with ionic strength 0.3, 2.1, and 4.1, created with the electrolyte NaCl, at room temperature 22+-1degC. By the methods of chemical, potentiometric, thermographic, and IR-spectrometric analyses, it was shown that all the synthesized precipitates are mechanical mixtures of two phases - thorium hydroxide and iron hydroxide - and not a new hydrated compound. The formal solubility of the precipitates of mixed hydroxides was determined. It was shown that the numerical value of the formal solubility depends on the conditions of formation and age of the precipitates

Chloride absorption by root, leaf and floral tissues of Petunia

International Nuclear Information System (INIS)

Jooste, J.H.

1980-01-01

Chloride absorption by root, leaf and floral tissues of Petunia was compared at two temperatures (30 and 2 degrees Celcius), employing different absorption periods, and in the presence and absence of a desorption treatment. All treatments revealed highest absorption by floral tissue. This was further confirmed by the absorption of chloride by the various tissues from solutions in the low (0-1 mM) and high (1-50 mM) concentration ranges. The results offer a possible explanation for the observed effects of organic and inorganic solutes on the longevity of cut flowers [af

Mass transport and chloride ion complexes in occluded cell

International Nuclear Information System (INIS)

Tsuru, T.; Hashimoto, K.; Nishikata, A.; Haruyama, S.

1989-01-01

Changes in the transport and the concentration of ions in a model occluded cell are traced during galvanostatic anodic polarization of a mild steel and a stainless steel. Apparent transport numbers of anions and cations, which were estimated from chemical analysis of solution, were different from those calculated from known mobility data. At the initial stage of the polarization, the transport number of chloride ion was almost unity, and then decreased gradually. For the mild steel, the concentration of total chloride ion accumulated in the occluded compartment increased with the anodic charge passed, and the amount of chloride ion complexed with cations also increased. The chloride complex was estimated as FeCl + . For SUS304 stainless steel, the total chloride ion increased, however, the free chloride ion, which responded to an Ag/AgCl electrode remained approximately 2 mol/dm 3 . Therefore, most of the chloride ions transferred into the occluded cell formed complex ions, such as CrCl n 3-n . The number of chloride ion coordinated to ferrous and chromic ions was estimated from the data fo mass transport for the case of the mild steel and the stainless steel. (author) 9 refs., 14 figs

Effect of Ammonium Chloride on the Efficiency with Which Copper Sulfate Activates Marmatite: Change in Solution Composition and Regulation of Surface Composition

Directory of Open Access Journals (Sweden)

Shengdong Zhang

2018-06-01

Full Text Available Zinc sulfide minerals are the primary choice for zinc extraction and marmatite is one of the two most common zinc sulphide minerals (sphalerite and marmatite, therefore it is of great significance to study and optimize the flotation of marmatite. To improve the activation of copper sulfate on marmatite, a method involving the addition of ammonium chloride is devised. The method has been proven to be an effective way of improving the activation efficiency of copper sulfate towards marmatite under alkaline conditions. The strengthening mechanism was studied using micro-flotation, adsorption test, X-ray photoelectron spectroscopy, and by analyzing changes in solution composition. Flotation test results show that the activation effect of the copper sulfate towards marmatite is enhanced with the addition of ammonium chloride. According to the results of the adsorption measurements and X-ray photoelectron spectroscopy analysis, when the marmatite surface is activated using copper sulfate with added ammonia chloride, it adsorbs more copper sulfide and less copper hydroxide and zinc hydroxide. These changes in surface composition are believed to occur via the following process: NH3(aq promotes the dissolution of zinc hydroxide and then facilitates the conversion of surface copper hydroxide to copper sulfide. In addition, the occurrence of Cu(NH3n2+ can promote the adsorption of copper ions (Cu2+ can be stored as Cu(NH3n2+ via complexation, and then, when the concentration of copper ions decreases, Cu2+ can be released through the decompositionof Cu(NH3n2+. Hence, the copper ion concentration can be maintained and this can facilitate the adsorption of Cu2+ on marmatite. Based on a comprehensive analysis of all our results, we propose that adding ammonium chloride to the copper sulfate changes the solution components (i.e., the presence of NH3(aq and Cu(NH3n2+ and then regulates the surface composition of marmatite. The change in surface composition

Determine the Intensity of UV Radiation and H2O2 on the Removal of Methylene Blue from Synthetic Wastewater

Directory of Open Access Journals (Sweden)

Mehdi Hosseini

2015-03-01

Full Text Available Background: There is a tremendous amount of color in textile wastewater that discharge it to the environment can cause a lot of environmental problems. The aim of this study is to evaluate the photocatalytic process UV/H2O2 to remove methylene blue dye from synthetic wastewater. Methods: UVC lamp was used as light source. In this study the effect of UV light intensity, irradiation distance, hydrogen peroxide concentration, and reaction time on the removal of methylene blue from aqueous solutions were studied. Data was analyzed by SPSS 18 and excel software. Results: The result showed that with increasing concentration of hydrogen peroxide, the color removal increases. Color removal changes were negligible at H2O2 concentration more than 5 mM. After 10 minutes reaction time at H2O2 concentration of 1 mm, efficiency of UVC/H2O2 is equal to 36.6%. Whilst at 5 mM concentration, removal efficiency is 89.2%. By increasing intensity of UV radiation, dye removal measure is also was increased, as the highest percentage of dye removal was obtained at 24 W radiation intensity. Conclusion: in present study, type of radiation and measure of hydrogen peroxide were the main factors in removal of methylene blue. Due to high efficiency of UVC/H2O2 process in removal of dye from aqueous solution, this method can use as an efficient process for removal of dye.

Intratesticular hypertonic sodium chloride solution treatment as a method of chemical castration in cattle.

Science.gov (United States)

Neto, Olmiro Andrade; Gasperin, Bernardo G; Rovani, Monique T; Ilha, Gustavo F; Nóbrega, Janduí E; Mondadori, Rafael G; Gonçalves, Paulo B D; Antoniazzi, Alfredo Q

2014-10-15

Castration of male calves is necessary for trading to facilitate handling and prevent reproduction. However, some methods of castration are traumatic and lead to economic losses because of infection and myiasis. The objective of the present study was to evaluate the efficiency of intratesticular injection (ITI) of hypertonic sodium chloride (NaCl; 20%) solution in male calf castration during the first weeks of life. Forty male calves were allocated to one of the following experimental groups: negative control-surgically castrated immediately after birth; positive control -intact males; G1-ITI from 1- to 5-day old; G2-ITI from 15- to 20-day old; and G3-ITI from 25- to 30-day old. Intratesticular injection induced coagulative necrosis of Leydig cells and seminiferous tubules leading to extensive fibrosis. Testosterone secretion and testicular development were severely impaired in 12-month-old animals from G1 and G2 groups (P<0.05), in which no testicular structure and sperm cells were observed during breeding soundness evaluation. Rectal and scrotal temperatures were not affected by different procedures. In conclusion, ITI of hypertonic NaCl solution induces sterility and completely suppresses testosterone secretion when performed during the first 20 days of life. Copyright © 2014 Elsevier Inc. All rights reserved.

Preoperative Localization of Mediastinal Parathyroid Adenoma with Intra-arterial Methylene Blue

Energy Technology Data Exchange (ETDEWEB)

Salman, Rida; Sebaaly, Mikhael G. [American University of Beirut Medical Center, Department of Diagnostic Radiology (Lebanon); Wehbe, Mohammad Rachad; Sfeir, Pierre; Khalife, Mohamad [American University of Beirut Medical Center, Department of General Surgery (Lebanon); Al-Kutoubi, Aghiad, E-mail: mk00@aub.edu.lb [American University of Beirut Medical Center, Department of Diagnostic Radiology (Lebanon)

2017-06-15

Ectopic parathyroid is found in 16% of patients with hyperparathyroidism. 2% of ectopic parathyroid adenomas are not accessible to standard cervical excision. In such cases, video-assisted thoracoscopic resection is the recommended definitive treatment. We present a case of mediastinal parathyroid adenoma localized preoperatively by injecting methylene blue within a branch of the internal mammary artery that is supplying the adenoma. Intra-arterial methylene blue injection facilitated visualization and resection of the adenoma. The preoperative intra-arterial infusion of methylene blue appears to be an effective and safe method for localization of ectopic mediastinal parathyroid adenomas and allows rapid identification during thoracoscopic resection.

Chloride Ingress in Concrete Cracks under Cyclic Loading

DEFF Research Database (Denmark)

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

2005-01-01

was similar for both sets and the maximum crack width was kept constant throughout the exposure period by means of precracking and an external prestressed reinforcement. Chloride profiles after 40 days revealed a considerable increase in ingress towards the crack tip in contrast to data from the literature....... 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...

Study of extraction-spectrophotometric micro-determination of boron with methylene blue and its application

International Nuclear Information System (INIS)

Zhu Daohong

1990-08-01

A sensitive extraction-spectrophotometric method for microdetermination of boron with methylene blue was investigated. The method was based on the extraction of a BF 4 - -methylene blue complex into dichloroethane. Boron was determined directly by measuring the absorbance at 658 nm. The calibration graph was linear over the range of 2.5 x 10 -9 to 8 x 10 -8 g/mL. The blank, mechanism of the reactions, interference of other ions and some optimum conditions of the method were studied in detail. The main source of the blank resulted from methylene blue and the complex of F - -methylene blue. In order to reduce the blank, the amounts of methylene blue, H 2 SO 4 and HF were used as less as possible. Only one to one complex BF 4 - -methylene blue was formed in the medium of H 2 SO 4 . About 90% of methylene blue and F - -methylene blue complex was removre with 5 ml of water and only a little amount of BF 4 -methylene blue complex was decomposed. The extraction-spectrophotometric method with methylene blue was first applied to the microdetermination of boron in sodium metal and UF 6 . The sample of sodium metal was taken and weighed in the glovebox filled with argon. Then sodium metal was oxidized, hydrolyzed, netralized and fluorizated with H 2 O, H 2 SO 4 and HF, respectively. The 0.5 ppm of boron in sodium metal was determined with a relative error about ±4%. This method can be applied to the determination of boron in sodium metal, sodium sulfate and sodium hydroxide at diffeent grades. The species of boron in the hydrolysate of UF 6 is BF 4 - anion, so the sample can be directly analyzed. Boron contents in the range of 0.1 to 0.5 ppm was determined with a relative error about ±3%. Six samples could be analysed in 2h

Electrochemical Migration on Electronic Chip Resistors in Chloride Environments

DEFF Research Database (Denmark)

Minzari, Daniel; Jellesen, Morten Stendahl; Møller, Per

2009-01-01

Electrochemical migration behavior of end terminals on ceramic chip resistors (CCRs) was studied using a novel experimental setup in varying sodium chloride concentrations from 0 to 1000 ppm. The chip resistor used for the investigation was 10-kΩ CCR size 0805 with end terminals made of 97Sn3Pb...... rate of the Sn and stability of Sn ions in the solution layer play a significant role in the formation of dendrites, which is controlled by chloride concentration and potential bias. Morphology, composition, and resistance of the dendrites were dependent on chloride concentration and potential....

Corrosion behaviour of Alloy 800 in high temperature aqueous solutions: Electrochemical studies

International Nuclear Information System (INIS)

Olmedo, A.M.; Villegas, M.; Alvarez, M.G.

1996-01-01

The anodic behaviour and passivity breakdown of Alloy 800 in aqueous solutions of sodium chloride, sodium sulphate and sodium bicarbonate were studied by electrochemical techniques in the temperature range from 60 C to 280 C. The pitting resistance and pitting morphology of the alloy in chloride plus sulphate and chloride plus bicarbonate mixtures, at 60 C and 280 C, were also examined. Increasing bicarbonate or sulphate additions to chloride solutions shift the characteristic pitting potential of Alloy 800 to higher values, both at low and high temperatures. Changes in pitting morphology were observed in sulphate containing solutions while the morphology of the attack found in bicarbonate containing solutions was similar to that in pure chloride solutions. Finally, no localized or substantial generalized corrosion was detected in pure sulphate or bicarbonate solutions at any temperature. (orig.)

Methylene Blue to Treat Protamine-induced Anaphylaxis Reactions. An Experimental Study in Pigs

Directory of Open Access Journals (Sweden)

Agnes Afrodite S. Albuquerque

Full Text Available ABSTRACT Objective: To examine if methylene blue (MB can counteract or prevent protamine (P cardiovascular effects. Methods: The protocol included five heparinized pig groups: Group Sham -without any drug; Group MB - MB 3 mg/kg infusion; Group P - protamine; Group P/MB - MB after protamine; Group MB/P - MB before protamine. Nitric oxide levels were obtained by the nitric oxide/ozone chemiluminescence method, performed using the Nitric Oxide Analizer 280i (Sievers, Boulder, CO, USA. Malondialdehyde plasma levels were estimated using the thiobarbiturate technique. Results: 1 Groups Sham and MB presented unchanged parameters; 2 Group P - a Intravenous protamine infusion caused mean arterial pressure decrease and recovery trend after 25-30 minutes, b Cardiac output decreased and remained stable until the end of protamine injection, and c Sustained systemic vascular resistance increased until the end of protamine injection; 3 Methylene blue infusion after protamine (Group P/MB - a Marked mean arterial pressure decreased after protamine, but recovery after methylene blue injection, b Cardiac output decreased after protamine infusion, recovering after methylene blue infusion, and c Sustained systemic vascular resistance increased after protamine infusion and methylene blue injections; 4 Methylene blue infusion before protamine (Group MB/P - a Mean arterial pressure decrease was less severe with rapid recovery, b After methylene blue, there was a progressive cardiac output increase up to protamine injection, when cardiac output decreased, and c Sustained systemic vascular resistance decreased after protamine, followed by immediate Sustained systemic vascular resistance increase; 5 Plasma nitrite/nitrate and malondialdehyde values did not differ among the experimental groups. Conclusion: Reviewing these experimental results and our clinical experience, we suggest methylene blue safely prevents and treats hemodynamic protamine complications, from the

Chloride adsorption by calcined layered double hydroxides in hardened Portland cement paste

KAUST Repository

Yoon, Seyoon; Moon, Juhyuk; Bae, Sungchul; Duan, Xiaonan; Giannelis, Emmanuel P.; Monteiro, Paulo M.

2014-01-01

This study investigated the feasibility of using calcined layered double hydroxides (CLDHs) to prevent chloride-induced deterioration in reinforced concrete. CLDHs not only adsorbed chloride ions in aqueous solution with a memory effect but also had

Adsorption of methylene blue on raw and MTZ/imogolite hybrid surfaces: Effect of concentration and calorimetric investigation

Energy Technology Data Exchange (ETDEWEB)

Guerra, Denis L., E-mail: dlguerra@pq.cnpq.br [Universidade Federal de Mato Grosso, DRM, UFMT, Mato Grosso 78060 900 (Brazil); Batista, Adriano C. [Universidade Estadual do Norte Fluminense, UENF, Rio de Janeiro 28013 02 (Brazil); Viana, Rubia R. [Universidade Federal de Mato Grosso, DRM, UFMT, Mato Grosso 78060 900 (Brazil); Airoldi, Claudio [Chemistry Institute, State University of Campinas, PO Box 6154, 13084-971 Campinas, Sao Paulo (Brazil)

2010-11-15

The synthetic imogolite sample was used for organofunctionalization process with 2-mercaptothiazoline (MTZ). The compound 2-mercaptothiazoline was anchored onto imogolite surface by heterogeneous route. Due to the increment of basic centers attached to the pendant chains the dye adsorption capability of the final chelating material, was found to be higher than is precursor. The ability of these materials to remove methylene blue from aqueous solution was followed by a series of adsorption isotherms at room temperature and pH 4.0. The maximum number of moles adsorbed was determined to be 40.32 x 10{sup -2} and 65.13 x 10{sup -2} mmol g{sup -1} for IMO and IMO{sub MTZ}, respectively. The energetic effects caused by dye cations adsorption were determined through calorimetric titrations. Thermodynamics indicated the existence of favorable conditions for such methylene blue-nitrogen and sulfur interactions.

Performance of zeolite ceramic membrane synthesized by wet mixing method as methylene blue dye wastewater filter

Science.gov (United States)

Masturi; Widodo, R. D.; Edie, S. S.; Amri, U.; Sidiq, A. L.; Alighiri, D.; Wulandari, N. A.; Susilawati; Amanah, S. N.

2018-03-01

Problem of pollution in water continues in Indonesia, with its manufacturing sector as biggest contributor to economic growth. One out of many technological solutions is post-treating industrial wastewater by membrane filtering technology. We presented a result of our fabrication of ceramic membrane made from zeolite with simple mixing and he. At 5% of (poring agent):(total weight), its permeability stays around 2.8 mD (10‑14m2) with slight variance around it, attributed to the mixture being in far below percolating threshold. All our membranes achieve remarkable above 90% rejection rate of methylene blue as solute waste in water solvent.

Development and validation of a gas chromatography/mass spectrometry procedure for confirmation of para-toluenesulfonamide in edible fish fillet tissue.

Science.gov (United States)

Idowu, Olutosin R; Kijak, Philip J; Meinertz, Jeffery R; Schmidt, Larry J

2004-01-01

Chloramine-T is a disinfectant being developed as a treatment for bacterial gill disease in cultured fish. As part of the drug approval process, a method is required for the confirmation of chloramine-T residues in edible fish tissue. The marker residue that will be used to determine the depletion of chloramine-T residues from the edible tissue of treated fish is para-toluenesulfonamide (p-TSA), a metabolite of chloramine-T. The development and validation of a procedure for the confirmation of p-TSA is described. Homogenized fish tissue is dried by mixing with anhydrous sodium sulfate, and the mixture is extracted with methylene chloride. The extract is passed through a silica gel solid-phase extraction column, from which p-TSA is subsequently eluted with acetonitrile. The acetonitrile extract is evaporated, and the oily residue is dissolved in hexane. The hexane solution is shaken with fresh acetonitrile. The acetonitrile solution is evaporated and the residue is redissolved in dilute potassium hydroxide solution. The aqueous solution is extracted with methylene chloride to further remove more of the fat co-extractive. The aqueous solution is reacted with pentafluorobenzyl bromide in presence of tetrabutylammonium hydrogensulfate. The resulting di-(pentafluorobenzyl) derivative of p-TSA is analyzed by gas chromatography/mass spectrometry. This method permits the confirmation of p-TSA in edible fish tissue at 20 ppb.

Synthesis and photocatalytic degradation study of methylene blue dye under visible light irradiation by Fe1-xBixVO4 solid solutions (0 ≤ x ≤ 1.0)

Science.gov (United States)

Bera, Ganesh; Reddy, V. R.; Mal, Priyanath; Das, Pradip; Turpu, G. R.

2018-05-01

The novel hetero-structures Fe1-xBixVO4 solid solutions (0 ≤ x ≤ 1.0) with the two dissimilar end member of FeVO4 - BiVO4, were successfully synthesized by the standard solid state reaction method. The structural and chemical properties of as prepared photo-catalyst samples were characterized by X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR) and UV-visible absorption spectroscopy techniques. It is confirmed from the results of XRD, Raman and FT-IR that FeVO4 and BiVO4 are in triclinic (space group P-1 (2)) and monoclinic (space group I2/b (15)) phases respectively. The Bi incorporation into Fe site of FeVO4 emerges as hetero-structures of both the end members of the solid solutions. In addition, the photocatalytic activity in the degradation of methylene blue (MB) dye under visible light irradiation was carried out through UV-visible spectroscopy measurement of photo-catalysts FeVO4, BiVO4 and mixed phases of both photo-catalyst. The results indicate that under visible light irradiation the photocatalytic activity of mixed phases were very effective and higher than the both single phases of the solid solutions. The composition x= 0.25 exhibits an excellent photocatalytic property for the degradation of MB solution under visible light irradiation rather than other.

Effectiveness of ophthalmic solution preservatives: a comparison of latanoprost with 0.02% benzalkonium chloride and travoprost with the sofZia preservative system

OpenAIRE

Ryan, Gerard; Fain, Joel M; Lovelace, Cherie; Gelotte, Karl M

2011-01-01

Abstract Background Although in vitro and in vivo laboratory studies have suggested that benzalkonium chloride (BAK) in topical ophthalmic solutions may be detrimental to corneal epithelial cells, multiple short- and long-term clinical studies have provided evidence supporting the safety of BAK. Despite the conflicting evidence, BAK is the most commonly used preservative in ophthalmic products largely due to its proven antimicrobial efficacy. This study was designed to characterize the antimi...

Photocatalytic Degradation of Methylene Blue Using TiO2 Impregnated Diatomite

Directory of Open Access Journals (Sweden)

Ranfang Zuo

2014-01-01

Full Text Available Nano-TiO2 showed a good catalytic activity, but it is easy to agglomerate, resulting in the reduction or even complete loss of photocatalytic activity. The dispersion of TiO2 particles on porous materials was a potential solution to this problem. Diatomite has high specific surface and absorbability because of its particular shell structure. Thus, TiO2/diatomite composite, prepared by loading TiO2 on the surface of diatomite, was a good photocatalyst, through absorbing organic compounds with diatomite and degrading them with TiO2. Scanning electron microscopy (SEM, energy dispersive spectrum (EDS, X-ray diffraction (XRD, chemical analysis, and Fourier transform infrared spectrometry (FTIR indicated that TiO2 was impregnated well on the surface of diatomite. Furthermore, TiO2/diatomite was more active than nano-TiO2 for the degradation of methylene blue (MB in solution. MB at concentrations of 15 and 35 ppm can be completely degraded in 20 and 40 min, respectively.

Complications of Methylene Blue Dye in Breast Surgery: Case Reports and Review of the Literature

Directory of Open Access Journals (Sweden)

FJ Reyes, MB Noelck, C Valentino, L Grasso-LeBeau, JE Lang

2011-01-01

Full Text Available Introduction: Methylene blue dye has been used worldwide successfully with few complications in breast surgery. We present two different complications involving methylene blue: 1 skin and parenchymal necrosis when dye was injected in a subdermal fashion and 2 Mycoplasma infection caused by contaminated methylene blue in breast reduction surgery.Methods: We present two cases seen at the University of Arizona during 2008 and referred to a breast surgeon for management. We evaluated and managed complications of methylene blue dye injected by 2 referring surgeons for different indications. A review of the literature was performed.Results: The first case is a 67 year old female diagnosed with infiltrating ductal carcinoma of the left breast for which she was treated by her initial surgeon with left segmental mastectomy and sentinel node biopsy. The operating surgeon injected methylene blue in a subareolar subdermal fashion (distant from the primary tumor; unfortunately the patient suffered skin and breast necrosis requiring multiple surgical debridements and finally achieving delayed primary closure. The second case is a 45 year old female with infiltrating lobular carcinoma with a history of Mycoplasma infection secondary to methylene blue injected for breast reduction surgery. She required multiple debridements and had granulomas masquerading as cancer on MRI that confounded her extent of disease.Conclusions: The use of methylene blue dye in breast surgery is not without risk. In both cases methylene blue was responsible for complications requiring surgical debridement for local wound problems. In each case severe necrosis and infection were present. Methylene blue may cause not only significant morbidity, but may also produce cosmetically unsatisfactory results.

Effect of Using Metakaolin on Chloride Ion Penetration in High Performance Steel Fiber Reinforced Concrete

Directory of Open Access Journals (Sweden)

Adnan Mohammed Shihab

2016-03-01

Full Text Available This paper attempts to reduce the penetrability of high performance steel fiber reinforced concrete to chloride ions originating from external sources, by using High Reactivity Metakaolin (HRM as a highly active pozzolanic material, in order to prolong the time to initiation of the steel fibers corrosion and to minimize concrete damage that may occur due to the exposure to chloride ion penetration. According to pozzolanic activity index (P.A.I., 8% content of HRM was used as a partial replacement by weight of cement with 2% steel fibers by volume of concrete. During the exposure period of 300 days in 4.5% of NaCl solution, the total and free chloride contents (Cltotal, Clfree with the chloride profiles at the ages of 28 and 300 days were investigated. Also the rapid chloride penetrability test (RCPT, compressive and flexural strengths tests were conducted at the ages of 28, 90, 180 and 300 days. Results showed that the incorporation of 8% HRM caused a reduction in the (Clfree/Cltota ratio, the chloride penetration depth and the electrical conductivity with percentages of 21%, 40% and 43% respectively after 300 days exposure to chloride solution in comparing with the mix of 0% HRM. Results also indicated that the losses in compressive and flexural strengths after exposure of 300 days to chloride solution for the mix incorporating 8% HRM were by 5% and 5.8% respectively while they reached 9.5% and 11% respectively for the mix without HRM in relation to the correspondent test specimens cured in tap water.

The solvent extraction of zinc, iron, and indium from chloride solutions by neutral organophosphorus compounds

International Nuclear Information System (INIS)

Preston, J.S.; Du Preez, A.C.

1985-01-01

The preparation of several neutral organophosphorus compounds and their evaluation as selective extractants for zinc in chloride media are described. The compounds belong to the series trialkyl phosphates (RO) 3 PO, dialkyl alkylphosphonates R'PO(OR) 2 , alkyl dialkylphosphinates R 2 'PO(OR), and trialkyl-phosphine oxides R 3 'PO. They were characterized by measurement of their physical properties (melting and boiling points, refractive indices, and densities), and their purities were confirmed by osmometric determination of their molecular masses; by carbon and hydrogen microanalysis; by the titrimetric determination of acidic impurities; and, for liquid products, by comparison of their experimental molar refractivities with empirical values. Metal-distribution equilibria were determined for solutions of the extractants in xylene and aqueous phase containing 0,5 to 5,0 M sodium chloride. Moderately good selectivities were shown for zinc(II) over iron(III), and excellent selectivities were shown for zinc(II) over iron(II), copper(II), lead(II), and cadmium(II). The extraction of indium(III) was similar to that of zinc(II). The extraction of zinc(III), iron(III), and indium(III) increased markedly through the series. (RO) 3 PO 2 2 'PO(OR) 3 'PO. The incorporation of phenyl groups into the compounds led to weaker extraction. The extracted complexes of zinc(II), iron(III), and indium(III) have the stoichiometries ZnCl 2 L 2 ,FeCl 3 L 2 (H 2 O), and InCl 3 L 2 (H 2 O) respectively, where L represents the neutral organophosphorus compound

Optical Studies on Sol-Gel Derived Lead Chloride Crystals

OpenAIRE

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

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.

Green synthesis of silver nanoparticle-reduced graphene oxide using Psidium guajava and its application in SERS for the detection of methylene blue

Science.gov (United States)

Chettri, Prajwal; Vendamani, V. S.; Tripathi, Ajay; Singh, Manish Kumar; Pathak, Anand P.; Tiwari, Archana

2017-06-01

Here we present the synthesis of reduced graphene oxide and silver nanoparticle-reduced graphene oxide composites using aqueous extract of dry leaves of Psidium guajava by one pot reflux method. Psidium guajava extract simultaneously reduces silver nitrate and graphene oxide in the reaction mixture which is confirmed by various spectroscopic techniques. Variable concentrations of silver nitrate solution are used to obtain reduced graphene oxide with different dosage of silver nanoparticles and the resultant composites are examined using surface enhanced Raman scattering measurements. Considering methylene blue as a probe molecule, it is found that the surface enhanced Raman scattering activity increases with the increase in the dose of silver nanoparticles. Our as-synthesised silver nanoparticle-reduced graphene oxide composite shows remarkable performance in detecting methylene blue with concentration as low as 10-8 M for which the enhancement factor is 4.6 × 105. In addition, we report that the reduced graphene oxide quenches the photoluminescence of methylene blue more efficiently than silver nanoparticle-reduced graphene oxide composite. The charge transfer states have been extracted which are mainly responsible for the quenching processes.

Methylene Blue for Vasoplegia When on Cardiopulmonary Bypass During Double-Lung Transplantation.

Science.gov (United States)

Carley, Michelle; Schaff, Jacob; Lai, Terrance; Poppers, Jeremy

2015-10-15

Vasoplegia syndrome, characterized by hypotension refractory to fluid resuscitation or high-dose vasopressors, low systemic vascular resistance, and normal-to-increased cardiac index, is associated with increased morbidity and mortality after cardiothoracic surgery. Methylene blue inhibits inducible nitric oxide synthase and guanylyl cyclase, and has been used to treat vasoplegia during cardiopulmonary bypass. However, because methylene blue is associated with increased pulmonary vascular resistance, its use in patients undergoing lung transplantion has been limited. Herein, we report the use of methylene blue to treat refractory vasoplegia during cardiopulmonary bypass in a patient undergoing double-lung transplantation.

Photocatalysis of methylene blue contaminated water using titania fiber doped with silicon

International Nuclear Information System (INIS)

Ugarteche, C.V.; Alves, A.K.; Berutti, F.A.; Bergmann, C.P.

2009-01-01

In this work, titania fibers doped with silicon were synthesized by electro spinning methodology, using titanium propoxide, silicon tetra propoxide and a solution of polyvinylpyrrolidone as precursors. The non-tissue material obtained was characterized by X-ray diffraction to determine the phase and crystallite size, BET method to determine the surface and SEM to analyze the microstructure of the fibers. The photo catalytic activity of the fibers in comparison with the standard TiO 2 Degussa P25 was evaluated using a 20ppm methylene blue solution. The composition containing 30% of silicon kept the anatase phase stable until the heat treatment temperature of 800 deg C. In the other compositions there was a formation of the rutile phase, which is less photoactive. The compositions containing silicon were photo catalytic efficient and some of them were more active that the standard P25. (author)

The evaluation of organic inhibitors for the protection of grade 5 titanium in chloride media

International Nuclear Information System (INIS)

Popa, L.; Tunaru, M.; Velciu, L.

2013-01-01

The corrosion failures of titanium and titanium alloys are inevitably associated with the non-observance of environmental limits prescribed in corrosion handbooks, such as its use in solutions chloride. Titanium alloys are often used in the thermal transfer technology especially in the heat exchangers cooled with sea cooled water. However, it is not indicated its use in strong oxidant and any concentrated chloride environments. For the evaluation of grade 5 titanium alloy samples behaviour in solutions containing chloride ions in presence, respectively, absence of some organic inhibitors were performed by potentiodynamic polarization method. On the basis of our experimental results we consider that the most adequate inhibitor for the system Ti- 5 alloys/0 .083 M NaCl solution is the resorcinol. (authors)

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)

Sardroodi, Jaber Jahanbin; Azamat, Jafar; Atabay, Maryam

2011-01-01

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.

NMR studies of proton exchange kinetics in aqueous formaldehyde solutions.

Science.gov (United States)

Rivlin, Michal; Eliav, Uzi; Navon, Gil

2014-05-01

Aqueous solutions of formaldehyde, formalin, are commonly used for tissue fixation and preservation. Treatment with formalin is known to shorten the tissue transverse relaxation time T2. Part of this shortening is due to the effect of formalin on the water T2. In the present work we show that the shortening of water T2 is a result of proton exchange between water and the major constituent of aqueous solutions of formaldehyde, methylene glycol. We report the observation of the signal of the hydroxyl protons of methylene glycol at 2ppm to high frequency of the water signal that can be seen at low temperatures and at pH range of 6.0±1.5 and, at conditions where it cannot be observed by the single pulse experiment, it can be detected indirectly through the water signal by the chemical exchange saturation transfer (CEST) experiment. The above finding made it possible to obtain the exchange rate between the hydroxyl protons of the methylene glycol and water in aqueous formaldehyde solutions, either using the dispersion of the spin-lattice relaxation rate in the rotating frame (1/T1ρ) or, at the slow exchange regime, from the line width hydroxyl protons of methylene glycol. The exchange rate was ∼10(4)s(-1) at pH 7.4 and 37°C, the activation energy, 50.2kJ/mol and its pH dependence at 1.1°C was fitted to: k (s(-1))=520+6.5×10(7)[H(+)]+3.0×10(9)[OH(-)]. Copyright © 2014. Published by Elsevier Inc.

Pseudopeptide-Based Hydrogels Trapping Methylene Blue and Eosin Y.

Science.gov (United States)

Milli, Lorenzo; Zanna, Nicola; Merlettini, Andrea; Di Giosia, Matteo; Calvaresi, Matteo; Focarete, Maria Letizia; Tomasini, Claudia

2016-08-16

We present herein the preparation of four different hydrogels based on the pseudopeptide gelator Fmoc-l-Phe-d-Oxd-OH (Fmoc=fluorenylmethyloxycarbonyl), either by changing the gelator concentration or adding graphene oxide (GO) to the water solution. The hydrogels have been analysed by rheological studies that demonstrated that pure hydrogels are slightly stronger compared to GO-loaded hydrogels. Then the hydrogels efficiency to trap the cationic methylene blue (MB) and anionic eosin Y (EY) dyes has been analyzed. MB is efficiently trapped by both the pure hydrogel and the GO-loaded hydrogel through π-π interactions and electrostatic interactions. In contrast, the removal of the anionic EY is achieved in less satisfactory yields, due to the unfavourable electrostatic interactions between the dye, the gelator and GO. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Potentiometric determination of chloride ions in circulating water systems of the Kirishinefteorgsintez production association

International Nuclear Information System (INIS)

Sukhova, N.S.; Skatina, L.I.

1993-01-01

The chloride content of circulating water and wastewater in industrial plants is one of the important indexes of contamination. The increasingly stringent sanitary and ecological requirements that have been imposed on wastewater are making it necessary to monitor the chloride content on a regular basis. It is difficult to use the mercurometric method of chloride determination that has been recommended for use in petroleum refineries in analyzing turbid of dark-colored waters with high contents of organic matter. Also, when the mercurometric method is used, accurate control of pH must be maintained in order to achieve good reproducibility of results. The authors are proposing a rapid method for monitoring the content of chloride ions in circulating water systems by potentiometric titration of a sample in a medium of glacial acetic acid by a 0.01 M solution of silver nitrate with the silver indicator electrode and a silver chloride auxiliary electrode EVL-1MZ, filled with a saturated solution of potassium nitrate. The potential is measured 30 sec after it has been established, in a type pH-121 potentiometer. The titration is performed from a microburette with a scale division of 0.02 cm 3 , with constant stirring of the test solution by means of a magnetic stirrer

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

International Nuclear Information System (INIS)

Gordeeva, V.P.; Glazkova, S.V.; Tsysin, G.I.; Ivanov, V.M.; Zolotov, Yu. A.

2003-01-01

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 (CE max ). 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)

Effects of chlorides on the hydration of 12CaO{center_dot}7Al2O3 solid solution

Energy Technology Data Exchange (ETDEWEB)

Sango, H.; Miyakawa, T.; Yasue, T.; Arai, Y. [Nihon Univ., Tokyo (Japan). Faculty of Science and Engineering

1995-01-01

The purpose of this paper was to compare the hydration rate of C12A7ss and to study the effects of chlorides on the hydration products and the hydration rate of C12A7ss. In this paper, `C12A7ss` is a general term for C11A7{center_dot}Ca(OH)2, 11CaO{center_dot}7Al2O3{center_dot}CaF2 and 11CaO{center_dot}7Al2O3{center_dot}CaCl2. The hydration process and the hydration rate of 12CaO{center_dot}7Al2O3 solution (C12A7ss) with and without various chlorides (CaCl2, MgCl2, NaCl, NH4Cl and AlCl3) has been determined at 25{degree}C. Various C12A7ss were prepared in burning method. When C12A7ss with various chlorides are hydrated, 3CaO{center_dot} Al2O3{center_dot}CaCl2{center_dot}10H2O(Friedel`s salt) is formed as the primary hydrate. The hydration rate of C12A7ss is decreased by the coexistence of CaCl2, MgCl2, NaCl or NH4Cl except AlCl3. As a result, the setting time of C12A7ss is extended and the unhydrate exists for a long time comparatively. 14 refs., 7 figs., 1 tab.

Selective and Efficient Solvent Extraction of Copper(II Ions from Chloride Solutions by Oxime Extractants

Directory of Open Access Journals (Sweden)

Zahra Kaboli Tanha

2016-06-01

Full Text Available Oxime extractants 3-tert-butyl-2-hydroxy-5-methyl benzaldehyde oxime (HL1 and 3-tert-butyl-2-hydroxy-5-methoxy benzaldehyde oxime (HL2 were synthesized and characterized by conventional spectroscopic methods. Suitable lipophilic nature of the prepared extractants allowed examining the ability of these molecules for extraction-separation of copper from its mixture with normally associated metal ions by performing competitive extraction experiments of Cu(II, Co(II, Ni(II, Zn(II, Cd(II and Pb(II ions from chloride solutions. Both ligands transfer selectively the copper ions into dichloromethane by a cation exchange mechanism. Conventional log-log analysis and isotherm curves showed that Cu(II ions are extracted as the complexes with 1:2 metal to ligand ratio by both extractants. Verification of the effect of the organic diluent used in the extraction of copper ions by HL1 and HL2 demonstrated that the extraction efficiency varies as: dichloromethane ~ dichloroethane > toluene > xylene > ethylacetate. Time dependency investigation of the extraction processes revealed that the kinetics of the extraction of copper by HL2 is more rapid than that of HL1. The application of the ligands for extraction-separation of copper ions from leach solutions of cobalt and nickel-cadmium filter-cakes of a zinc production plants was evaluated.

Conservation of minimally processed pineapple using calcium chloride, edible coating and gamma radiation

International Nuclear Information System (INIS)

Pilon, Lucimeire

2007-01-01

The aim of this study was to obtain a convenience type pineapple subjected to fresh-cut process and calcium chloride, wheat gluten and alginate-base edible coating and irradiation treatments. The fruits were washed, sanitized with Sumaveg (Sodium Dichloro-s-Triazinetrione) in a 200 mg L-1 chlorine-free solution at 7 deg C for 15 minutes, and then manually peeled. The peeled fruits were sliced into 1 cm thick slices, rinsed in 20 mg L-1 chlorine-free solution for 3 minutes and drained for 3 minutes. In the first experiment, the samples were treated with: 1% calcium chloride + vital wheat gluten solution; 1% calcium chloride + 1% alginate solution; and control. In the second experiment, the samples were treated with: 1% calcium chloride + vital wheat gluten solution + 2.3 kGy; 1% calcium chloride + 2.3kGy; irradiation with 2.3kGy; and control. The packing consisted of rigid polyethylene terephthalate (PET) trays with around 250 g of fruit. The irradiation was performed in a Cobalt-60 multipurpose irradiator with 92 kCi activity and dose value of 2.3 kGy h-1. The samples were stored at 5 ± 1 deg C and evaluated every other day for 12 days. In the first experiment pH and titratable acidity values showed slight variations but were similar between the treatments. There was a decrease in ascorbic acid values in all treatments. Browning was noticed in all treatments over the storage period. Although the values between the treatments were similar, the pineapple treated with calcium chloride + gluten showed firmer texture, less liquid loss, and lower values of polyphenoloxidase and peroxidase activities and CO 2 and ethylene production. Mesophiles and mold and yeast counts were also reduced. No Salmonella and E. coli were detected. Total coliform counts were low in all the treatments and appeared in just a few isolated samples during the storage period. Sensory analyses showed that the samples treated with calcium chloride + gluten had the lower scores for texture

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

Science.gov (United States)

2010-10-01

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

Film dosimeters based on methylene blue and methyl orange in polyvinyl alcohol

DEFF Research Database (Denmark)

Chung, W.H.; Miller, A.

1994-01-01

Polyvinyl alcohol (PVA) films containing methylene blue and methyl orange are useful as gamma and electron radiation dosimeters. Absorbed doses should not exceed 40 kGy for methylene blue and 500 kGy for methyl orange. Because PVA is water-soluble, the films may be made without toxic solvents...

Retrograde Instillation of Methylene Blue in the Difficult Diagnosis of BPF

Directory of Open Access Journals (Sweden)

F. Ravenna

2012-01-01

Full Text Available We report two cases in which we were able to diagnose bronchopleural fistula through retrograde methylene blue instillation during bronchoscopy. In the first case, methylene blue was injected through an abdominal drain, followed by air instillation and detected in the left bronchial tree, demonstrating the presence of a fistula in the lingula’s bronchus. In the second case, methylene blue was injected into a pleural drain, through a breach on a surgical suture and detected in the right bronchial tree, demonstrating the presence of a fistula in the right inferior bronchus. The retrograde instillation of methylene blue, through a drain in the abdomen or the thoracic wall, is a safe, cheap, and practical method that allows the bronchoscopist to identify the presence of a fistula and, more importantly, to identify the exact point on the bronchial tree where a fistula is located. This provides the possibility of sealing the fistula with a variety of devices. It is our opinion that this procedure should be considered a primary method of diagnosis when a bronchopleural fistula is suspected and a drain on the thoracic or abdominal wall is positioned such that effusions are able to drain.

INTERACTION MODE BETWEEN METHYLENE BLUE-Sm(III ...

African Journals Online (AJOL)

Preferred Customer

between methylene blue (MB)-Sm(III) complex and herring sperm DNA by using acridine orange .... the complex was recorded as KBr pellets on Spectrum One FTIR system (PE Company, USA), ..... mechanism of drugs and drug design.

Influence of Surface Pretreatment on the Corrosion Resistance of Cold-Sprayed Nickel Coatings in Acidic Chloride Solution

Science.gov (United States)

Scendo, Mieczyslaw; Zorawski, Wojciech; Staszewska-Samson, Katarzyna; Makrenek, Medard; Goral, Anna

2018-03-01

Corrosion resistance of the cold-sprayed nickel coatings deposited on the Ni surface (substrate) without and with abrasive grit-blasting treatment of the substrate was investigated. The corundum powder with different grain sizes was used. The corrosive environment contained an acidic chloride solution. The mechanism of the corrosion of nickel was suggested and discussed. Corrosion electrochemical parameters were determined by electrochemical methods. The corrosion effect of a nickel coating depends on the grain size used to prepare the substrate. The nickel coating after the medium grit-blasting treatment of the substrate was found to be the most corrosion resistant. However, the smallest resistance on the corrosion effect should be attributed to the nickel coating on the substrate after the coarse grit-blasting treatment.

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

International Nuclear Information System (INIS)

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

2008-01-01

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

Stress corrosion cracking of nickel alloys in bicarbonate and chloride solutions

International Nuclear Information System (INIS)

Ares, A. E.; Carranza, R. M.; Giordano, C. M.; Zadorozne, N. S.; Rebak, R.B.

2013-01-01

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 NaHCO 3 +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)

Charge-transfer complexes between p-toluidine and iodine in solution: a kinetic study

International Nuclear Information System (INIS)

Beggiato, G.; Casalbore, G.; Marconi, G.; Baraldi, C.

1985-01-01

The kinetics of charge-transfer interaction between p-toluidine and iodine in methylene chloride was investigated in depth. The thermal process of formation of the 'inner' complex was found to proceed to an equilibrium. The photochemical process follows a different reaction coordinate, going through the formation of an exciplex between the excited 'outer' complex and the amine ground state. In both cases the same ionic complex (Am 2 I + I - 3 , where Am stands for p-toluidine) was detected as the final product. (Author)

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.

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.

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.

Corrosion characteristics of thermal sprayed coating of stainless alloys in chloride solution; Taishoku gokin yosha himaku no enkabutsu yoekichu ni okeru fushoku tokusei

Energy Technology Data Exchange (ETDEWEB)

Suzuki, T. [Ajinomoto Co. Inc., Tokyo (Japan); Ishikawa, K. [Tokyo Metallikon Co. Ltd., Tokyo (Japan); Kitamura, Y. [Kitamura Technical Consultant Office, Kanagawa (Japan)

1994-12-15

With an objective to develop a thermal sprayed coating of environment interruption type that can be sprayed at sites, electrochemical discussions, SEM observation, and EPMA surface analysis were performed on corrosion characteristics in chloride solution of coatings of SUS 304, 316 and Hastelloy C thermally sprayed onto test pieces made of structural steel SS400, as well as the effect of improvement in corrosion resistance by means of a coating reforming treatment. The following conclusions were obtained: the degradation in corrosion resistance of the coatings is attributable to increase in anodic solubility due to appearance of innumerable crevices as a result of deposited particles forming porous structure and due to drop of Cr content in the matrix caused by generation of oxides on the surface of the crevices, by which the corrosion progresses in the form of crevice corrosion; and denseness of the passive coating is lost on the surface of the deposited particles, accelerating the cathodic reaction. A suitable means that could be used practically in chloride solution would be a method to use a material with less crevice susceptibility such as Hastelloy C as a base material, and seal the crevice structure with epoxy resin, etc. 7 refs., 10 figs., 3 tabs.

A conductance study of guanidinium chloride, thiocyanate, sulfate, and carbonate in dilute aqueous solutions: ion-association and carbonate hydrolysis effects.

Science.gov (United States)

Hunger, Johannes; Neueder, Roland; Buchner, Richard; Apelblat, Alexander

2013-01-17

We study the conductance of dilute aqueous solutions for a series of guandinium salts at 298.15 K. The experimental molar conductivities were analyzed within the framework of the Quint-Viallard theory in combination with Debye-Hückel activity coefficients. From this analysis, we find no evidence for significant ion association in aqueous solutions of guanidinium chloride (GdmCl) and guanidinium thiocyanate (GdmSCN), and the molar conductivity of these electrolytes can be modeled assuming a complete dissociation. The limiting ionic conductivity of the guanidinium ion (Gdm(+)) is accurately determined to λ(Gdm(+)) = 51.45 ± 0.10 S cm(2) mol(-1). For the bivalent salts guanidinium sulfate (Gdm(2)SO(4)) and guanidinium carbonate (Gdm(2)CO(3)), the molar conductivities show small deviations from ideal (fully dissociated electrolyte) behavior, which are related to weak ion association in solution. Furthermore, for solutions of Gdm(2)CO(3), the hydrolysis of the carbonate anion leads to distinctively increased molar conductivities at high dilutions. The observed ion association is rather weak for all studied electrolytes and cannot explain the different protein denaturing activities of the studied guanidinium salts, as has been proposed previously.

Measurement of chloride-ion concentration with long-period grating technology

Science.gov (United States)

Tang, Jaw-Luen; Wang, Jian-Neng

2007-06-01

A simple and low-cost long-period fiber grating (LPG) sensor suited for chloride-ion concentration measurement is presented. The LPG sensor is found to be sensitive to the refractive index of the medium around the cladding surface of the sensing grating, thus offering the prospect of development of practical sensors such as an ambient index sensor or a chemical concentration indicator with high stability and reliability. We measured chloride ions in a typical concrete sample immersed in salt water solutions with different weight concentrations ranging from 0% to 25%. Results show that the LPG sensor exhibited a linear decrease in the transmission loss and resonance wavelength shift when the concentration increased. The measurement accuracy for the concentration of salt in water solution is estimated to be 0.6% and the limit of detection for chloride ions is about 0.04%. To further enhance its sensitivity for chloride concentrations, we coated a monolayer of colloidal gold nanoparticles as the active material on the grating surface of the LPG sensor. The operating principle of sensing is based on the sensitivity of localized surface plasmon resonance of self-assembled gold colloids on the grating section of the LPG. With this method, a factor of two increase in the sensitivity of detecting chemical solution concentrations was obtained. The advantages of this type of fiber-optic sensor are that it is compact, relatively simple to construct and easy to use. Moreover, the sensor has the potential capability for on-site, in vivo and remote sensing, and it has potential use as a disposable sensor.

The Blue Coma: The Role of Methylene Blue in Unexplained Coma After Cardiac Surgery.

Science.gov (United States)

Martino, Enrico Antonio; Winterton, Dario; Nardelli, Pasquale; Pasin, Laura; Calabrò, Maria Grazia; Bove, Tiziana; Fanelli, Giovanna; Zangrillo, Alberto; Landoni, Giovanni

2016-04-01

Methylene blue commonly is used as a dye or an antidote, but also can be used off label as a vasopressor. Serotonin toxicity is a potentially lethal and often misdiagnosed condition that can result from drug interaction. Mild serotonin toxicity previously was reported in settings in which methylene blue was used as a dye. The authors report 3 cases of life-threatening serotonin toxicity in patients undergoing chronic selective serotonin reuptake inhibitor (SSRI) therapy who also underwent cardiac surgery and received methylene blue to treat vasoplegic syndrome. An observational study. A cardiothoracic intensive care unit (ICU) in a teaching hospital. Three patients who received methylene blue after cardiac surgery, later discovered to be undergoing chronic SSRI therapy. None. All 3 patients received high doses of fentanyl during general anesthesia. They all developed vasoplegic syndrome and consequently were given methylene blue in the ICU. All 3 patients developed serotonin toxicity, including coma, after this administration and diagnostic tests were negative for acute intracranial pathology. Coma lasted between 1 and 5 days. Two patients were discharged from the ICU shortly after awakening, whereas the third patient experienced a complicated postoperative course for concomitant refractory low-cardiac-output syndrome. Patients undergoing chronic SSRI therapy should not be administered methylene blue to treat vasoplegic syndrome. Copyright © 2016 Elsevier Inc. All rights reserved.

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.

Nanomolar determination of 4-nitrophenol based on a poly(methylene blue)-modified glassy carbon electrode.

Science.gov (United States)

Giribabu, Krishnamoorthy; Suresh, Ranganathan; Manigandan, Ramadoss; Munusamy, Settu; Kumar, Sivakumar Praveen; Muthamizh, Selvamani; Narayanan, Vengidusamy

2013-10-07

A poly(methylene blue)-modified glassy carbon electrode (PMB/GCE) was fabricated by electropolymerisation of methylene blue on a GCE and further utilized to investigate the electrochemical determination of 4-nitrophenol (4-NP) by cyclic voltammetry (CV), differential pulse voltammetry and chronocoulometry. The morphology of the PMB on GCE was examined using a scanning electron microscope (SEM). An oxidation peak of 4-NP at the PMB modified electrode was observed at 0.28 V, and in the case of bare GCE, no oxidation peak was observed, which indicates that PMB/GCE exhibits a remarkable effect on the electrochemical determination of 4-NP. Due to this remarkable effect of PMB/GCE, a sensitive and simple electrochemical method was proposed for the determination of 4-NP. The effect of the scan rate and pH was investigated to determine the optimum conditions at which the PMB/GCE exhibits a higher sensitivity with a lower detection limit. Moreover, kinetic parameters such as the electron transfer number, proton transfer number and standard heterogeneous rate constant were calculated. Under optimum conditions, the oxidation current of 4-NP is proportional to its concentration in the range of 15-250 nM with a correlation coefficient of 0.9963. The detection limit was found to be 90 nM (S/N = 3). The proposed method based on PMB/GCE is simple, easy and cost effective. To further confirm its possible application, the proposed method was successfully used for the determination of 4-NP in real water samples with recoveries ranging from 97% to 101.6%. The interference due to sodium, potassium, calcium, magnesium, copper, zinc, iron, sulphate, carbonate, chloride, nitrate and phosphate was found to be almost negligible.

Corrosion of titanium alloys in concentrated chloride solutions at temperature up to 160 deg C

International Nuclear Information System (INIS)

Ruskol, Yu.S.; Viter, L.I.; Balakin, A.I.; Fokin, M.N.

1982-01-01

Resistance of VT1-0 titanium and 4200, 4207 titanium alloys to pitting and total corrosion in chlorides of cadmium, potassium, nickel, ammonium, barium, calcium, lithium, magnesium in respect to pH value and temperature (120,140,160 deg C) is determined. The results obtained are presented as nomograms of stability. Possible reasons for corrosion behaviour of titanium in each of the chlorides are discussed

Characterisation of the steel concrete interface submitted to chloride-induced corrosion

International Nuclear Information System (INIS)

L'Hostis, V.; Amblard, E.; Guillot, W.; Paris, C.; Bellot-Gurlet, L.

2013-01-01

This paper deals with the characterisation by means of electrochemical, gravimetric and analytical methods of chloride-induced-corrosion behaviour of steel coupons embedded in chloride-containing-cement pastes. Corrosion rates were estimated from electrochemical measurements as well as gravimetric ones. They vary from 2.6 to 5.7μm/year for 5 and 10 g/L chloride-containing cement pastes. Analytical characterisations (including optical and electron microscopy and Raman micro-spectroscopy) showed that corrosion patterns are not depending on the chloride content of the cement paste (5 and 10 g/L chloride in the interstitial solution). A localised corrosion pattern composed of pits growing inside the metallic substratum, a corrosion products layer (CPL) and a transformed medium (TM) was pointed out. CPL can be divided into two sub-layers (CPL1 and CPL2), characterised by the presence or absence of calcium coming from the cement matrix. (authors)

Assessing Urinary Tract Junction Obstruction Defects by Methylene Blue Dye Injection.

Science.gov (United States)

Yun, Kangsun

2017-10-12

Urinary tract junction obstruction defects are congenital anomalies inducing hydronephrosis and hydroureter. Murine urinary tract junction obstruction defects can be assessed by tracking methylene blue dye flow within the urinary system. Methylene blue dye is injected into the renal pelvis of perinatal embryonic kidneys and dye flow is monitored from the renal pelvis of the kidney through the ureter and into the bladder lumen after applying hydrostatic pressure. Dye accumulation will be evident in the bladder lumen of the normal perinatal urinary tract, but will be constrained between the renal pelvis and the end point of an abnormal ureter, if urinary tract obstructions occur. This method facilitates the confirmation of urinary tract junction obstructions and visualization of hydronephrosis and hydroureter. This manuscript describes a protocol for methylene blue dye injection into the renal pelvis to confirm urinary tract junction obstructions.

Removal of trace mercury (II) from aqueous solution by in situ MnO(x) combined with poly-aluminum chloride.

Science.gov (United States)

Lu, Xixin; Huangfu, Xiaoliu; Zhang, Xiang; Wang, Yaan; Ma, Jun

2015-06-01

Removal of trace mercury from aqueous solution by Mn (hydr)oxides formed in situ during coagulation with poly-aluminum chloride (PAC) (in situ MnO(x) combined with PAC) was investigated. The efficiency of trace mercury removal was evaluated under the experimental conditions of reaction time, Mn dosage, pH, and temperature. In addition, the ionic strength and the initial mercury concentration were examined to evaluate trace mercury removal for different water qualities. The results clearly demonstrated that in situ MnO(x) combined with PAC was effective for trace mercury removal from aqueous solution. A mercury removal ratio of 9.7 μg Hg/mg Mn was obtained at pH 3. Furthermore, at an initial mercury concentration of 30 μg/L and pH levels of both 3 and 5, a Mn dosage of 4 mg/L was able to lower the mercury concentration to meet the standards for drinking water quality at less than 1 μg/L. Analysis by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy suggests that the hydroxyls on the surface of Mn (hydr)oxides are the active sites for adsorption of trace mercury from aqueous solution.

Separation studies of La(III) and Ce(III)/Nd(III)/Pr(III)/Sm(III) from chloride solution using DEHPA/PC88A in petrofin

International Nuclear Information System (INIS)

Acharya, Sagarika; Mishra, Sujata; Bhatta, B.C.

2017-01-01

The separation of La(III) and four other lanthanides. Ce, Nd, Pr and Sm from chloride solution has been studied using the two acidic organophosphorous extractants, DEHPA and PC88A in petrofin at pH 4.3. The metal content analysis was done using an ICP-OES spectrophotometer. The separation factors (β) was calculated and for La-Sm pair highest value of 9.7 was obtained. (author)

Remediation of cadmium- and lead-contaminated agricultural soil by composite washing with chlorides and citric acid.

Science.gov (United States)

Li, Yu-jiao; Hu, Peng-jie; Zhao, Jie; Dong, Chang-xun

2015-04-01

Composite washing of cadmium (Cd)- and lead (Pb)-contaminated agricultural soil from Hunan province in China using mixtures of chlorides (FeCl3, CaCl2) and citric acid (CA) was investigated. The concentrations of composite washing agents for metal removal were optimized. Sequential extraction was conducted to study the changes in metal fractions after soil washing. The removal of two metals at optimum concentration was reached. Using FeCl3 mixed with CA, 44% of Cd and 23% of Pb were removed, and 49 and 32% by CaCl2 mixed with CA, respectively. The mechanism of composite washing was postulated. A mixture of chlorides and CA enhanced metal extraction from soil through the formation of metal-chloride and metal-citrate complexes. CA in extract solutions promoted the formation of metal-chloride complexes and reduced the solution pH. Composite washing reduced Cd and Pb in Fe-Mn oxide forms significantly. Chlorides and CA exerted a synergistic effect on metal extraction during composite washing.

Concentrated aqueous sodium chloride solution in clays at thermodynamic conditions of hydraulic fracturing: Insight from molecular dynamics simulations

Science.gov (United States)

Svoboda, Martin; Lísal, Martin

2018-06-01

To address a high salinity of flow-back water during hydraulic fracturing, we use molecular dynamics (MD) simulations and study the thermodynamics, structure, and diffusion of concentrated aqueous salt solution in clay nanopores. The concentrated solution results from the dissolution of a cubic NaCl nanocrystal, immersed in an aqueous NaCl solution of varying salt concentration and confined in clay pores of a width comparable to the crystal size. The size of the nanocrystal equals to about 18 Å which is above a critical nucleus size. We consider a typical shale gas reservoir condition of 365 K and 275 bar, and we represent the clay pores as pyrophyllite and Na-montmorillonite (Na-MMT) slits. We employ the Extended Simple Point Charge (SPC/E) model for water, Joung-Cheatham model for ions, and CLAYFF for the slit walls. We impose the pressure in the normal direction and the resulting slit width varies from about 20 to 25 Å when the salt concentration in the surrounding solution increased from zero to an oversaturated value. By varying the salt concentration, we observe two scenarios. First, the crystal dissolves and its dissolution time increases with increasing salt concentration. We describe the dissolution process in terms of the number of ions in the crystal, and the crystal size and shape. Second, when the salt concentration reaches a system solubility limit, the crystal grows and attains a new equilibrium size; the crystal comes into equilibrium with the surrounding saturated solution. After crystal dissolution, we carry out canonical MD simulations for the concentrated solution. We evaluate the hydration energy, density profiles, orientation distributions, hydrogen-bond network, radial distribution functions, and in-plane diffusion of water and ions to provide insight into the microscopic behaviour of the concentrated aqueous sodium chloride solution in interlayer galleries of the slightly hydrophobic pyrophyllite and hydrophilic Na-MMT pores.

A Stereoselective [3+1] Ring Expansion for the Synthesis of Highly Substituted Methylene Azetidines.

Science.gov (United States)

Schmid, Steven C; Guzei, Ilia A; Schomaker, Jennifer M

2017-09-25

The reaction of rhodium-bound carbenes with strained bicyclic methylene aziridines results in a formal [3+1] ring expansion to yield highly substituted methylene azetidines with excellent regio- and stereoselectivity. The reaction appears to proceed through an ylide-type mechanism, where the unique strain and structure of the methylene aziridine promotes a ring-opening/ring-closing cascade that efficiently transfers chirality from substrate to product. The resultant products can be elaborated into new azetidine scaffolds containing vicinal tertiary-quaternary and even quaternary-quaternary stereocenters. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Adsorption behaviour of methylene blue onto Jordanian diatomite: a kinetic study.

Science.gov (United States)

Al-Ghouti, Mohammad A; Khraisheh, Majeda A M; Ahmad, Mohammad N M; Allen, Stephen

2009-06-15

The effect of initial concentration, particle size, mass of the adsorbent, pH and agitation speed on adsorption behaviour of methylene blue (MB) onto Jordanian diatomite has been investigated. The maximum adsorption capacity, q, increased from 75 to 105 mg/g when pH of the dye solution increased from 4 to 11. It is clear that the ionisable charge sites on the diatomite surface increased when pH increased from 4 to 11. When the solution pH was above the pH(ZPC), the diatomite surface had a negative charge, while at low pH (pHdiatomite did not follow the pseudo-first order model and had low correlation coefficients (R(2)diatomite when the particle size distribution is less than 250-500 microm. While at larger particle size 250-500 microm, the maximum uptake capacity was dependent on the particle size. It would imply that the MB adsorption is limited by the external surface and that intraparticle diffusion is reduced. The effect of the agitation speeds on the removal of MB from aqueous solution using the diatomite is quite low. The MB removal increased from 43 to 100% when mass of the diatomite increased from 0.3 to 1.7 g.

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)

Ribeiro, Ana C.F.; Gomes, Joselaine C.S.; Barros, Marisa C.F.; Lobo, Victor M.M.; Esteso, Miguel A.

2011-01-01

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 (D 11 , D 22 , D 12 , and D 21 ) for aqueous solutions containing NiCl 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 2 in different media.

Kinetic Effect on the Freezing of Ammonium-Sodium-Carbonate-Chloride Brines and Implications for Origin of Ceres' Bright Spots

Science.gov (United States)

Hodyss, R. P.; Thomas, E. C.; Vu, T. H.; Johnson, P. V.; Choukroun, M.

2017-12-01

Subsurface brines on Ceres containing natrite (Na2CO3) and smaller amounts of NH4Cl or NH4HCO3 have been proposed to reach the dwarf planet's surface from an internal reservoir, where the brines freeze and result in bright spots across Ceres. Kinetically frozen solutions containing the likely constituents of Ceres' subsurface brines (ammonium, sodium, carbonate, and chloride ions) were studied via infrared and micro-Raman spectroscopy, where the flash-frozen mixtures were found to preferentially form ammonium chloride and ammonium bicarbonate, even in sodium-dominated solutions. Additionally, sodium chloride only formed when sodium or chloride (or both) were present in excess in the brine solutions. Raman spectroscopy was further employed to analyze the effect of vacuum exposure on these frozen brines over longer periods of time to simulate the surface conditions of Ceres.

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

Directory of Open Access Journals (Sweden)

Takenouti, H.

2007-12-01

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

Fe(III/TiO2-Montmorillonite Photocatalyst in Photo-Fenton-Like Degradation of Methylene Blue

Directory of Open Access Journals (Sweden)

Is Fatimah

2015-01-01

Full Text Available A photodegradation process of methylene blue (MB in aqueous solution using Fe(III/TiO2-montmorillonite photocatalyst is presented. The photocatalyst material was prepared using Indonesian natural montmorillonite in TiO2 pillarization process followed by Fe(III ion exchange. Kinetic study on MB degradation was conducted and evaluated by three kinetic models: the pseudo-first- and second-order equations and the Elovich equation. From the results, it is concluded that the degradation under the photo-Fenton-like process utilizing Fe(III/TiO2-montmorillonite photocatalyst conformed to the Elovich kinetic model.

Electrochemical preparation of poly(methylene blue)/graphene nanocomposite thin films

International Nuclear Information System (INIS)

Erçarıkcı, Elif; Dağcı, Kader; Topçu, Ezgi; Alanyalıoğlu, Murat

2014-01-01

Highlights: • Poly(MB)/graphene thin films are prepared by a simple electrochemical approach. • Graphene layers in the film show a broad band in visible region of absorbance spectra. • Morphology of composite films indicates both disordered and ordered regions. • XRD reveals that nanocomposite films include rGO layers after electropolymerization process. • Chemically prepared graphene is better than electrochemically prepared graphene for electrooxidation of nitrite. - Abstract: Poly(methylene blue)/graphene nanocomposite thin films were prepared by electropolymerization of methylene blue in the presence of graphene which have been synthesized by two different methods of a chemical oxidation process and an electrochemical approach. Synthesized nanocomposite thin films were characterized by using cyclic voltammetry, UV–vis. absorption spectroscopy, powder X-ray diffraction, and scanning tunneling microscopy techniques. Electrocatalytical properties of prepared poly(methylene blue)/graphene nanocomposite films were compared toward electrochemical oxidation of nitrite. Under optimized conditions, electrocatalytical effect of nanocomposite films of chemically prepared graphene through electrochemical oxidation of nitrite was better than that of electrochemically prepared graphene

21 CFR 558.76 - Bacitracin methylene disalicylate.

Science.gov (United States)

2010-04-01

...) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS NEW ANIMAL DRUGS FOR USE IN ANIMAL FEEDS Specific New Animal Drugs for Use in Animal Feeds § 558.76 Bacitracin methylene disalicylate. (a) Approvals. Type A.... (b) Special considerations. The quantities of antibiotics are expressed in terms of the equivalent...

High surface area mesoporous activated carbon-alginate beads for efficient removal of methylene blue.

Science.gov (United States)

Nasrullah, Asma; Bhat, A H; Naeem, Abdul; Isa, Mohamed Hasnain; Danish, Mohammed

2018-02-01

High surface area mesoporous activated carbon-alginate (AC-alginate) beads were successfully synthesized by entrapping activated carbon powder derived from Mangosteen fruit peel into calcium-alginate beads for methylene blue (MB) removal from aqueous solution. The structure and surface characteristics of AC-alginate beads were analyzed using Fourier transform infra-red (FTIR) spectroscopy, scanning electron microscopy (SEM) and surface area analysis (S BET ), while thermal properties were tested using thermogravimetric analysis (TGA). The effect of AC-alginate dose, pH of solution, contact time, initial concentration of MB solution and temperature on MB removal was elucidated. The results showed that the maximum adsorption capacity of 230mg/g was achieved for 100mg/L of MB solution at pH 9.5 and temperature 25°C. Furthermore, the adsorption of MB on AC-alginate beads followed well pseudo-second order equation and equilibrium adsorption data were better fitted by the Freundlich isotherm model. The findings reveal the feasibility of AC-alginate beads composite to be used as a potential and low cost adsorbent for removal of cationic dyes. Copyright © 2017 Elsevier B.V. All rights reserved.

Rechargeable lithium and sodium anodes in chloroaluminate molten salts containing thionyl chloride

Energy Technology Data Exchange (ETDEWEB)

Fuller, J.; Osteryoung, R.A. [North Carolina State Univ., Raleigh, NC (United States). Dept. of Chemistry; Carlin, R.T.

1995-11-01

Lithium and sodium deposition-stripping studies were performed in room temperature buffered neutral chloroaluminate melts containing low concentrations of thionyl chloride (SOCl{sub 2}). The SOCl{sub 2} solute promotes high cycling efficiencies of the alkali metals in these electrolytes. Staircase cyclic voltammetry and chronopotentiometry show cycling efficiencies of approximately 90% for both lithium and sodium. High cycling efficiencies are maintained following extended exposure of the melt to the dry box atmosphere and after time delays at open circuit. The performance of the SOCl{sub 2}-promoted systems is substantially improved over previous studies in room temperature melts containing hydrogen chloride as the promoting solute.

Correction of Hemodynamics with Hypertonic Sodium Chloride Solution in Critical Conditions

Directory of Open Access Journals (Sweden)

P. S. Zhbannikov

2007-01-01

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

Chloride-catalyzed corrosion of plutonium in glovebox atmospheres

International Nuclear Information System (INIS)

Burgess, M.; Haschke, J.M.; Allen, T.H.; Morales, L.A.; Jarboe, D.M.; Puglisi, C.V.

1998-04-01

Characterization of glovebox atmospheres and the black reaction product formed on plutonium surfaces shows that the abnormally rapid corrosion of components in the fabrication line is consistent with a complex salt-catalyzed reaction involving gaseous hydrogen chloride (HCl) and water. Analytical data verify that chlorocarbon and HCl vapors are presented in stagnant glovebox atmospheres. Hydrogen chloride concentrations approach 7 ppm at some locations in the glovebox line. The black corrosion product is identified as plutonium monoxide monohydride (PuOH), a product formed by hydrolysis of plutonium in liquid water and salt solutions at room temperature. Plutonium trichloride (PuCl 3 ) produced by reaction of HCl at the metal surface is deliquescent and apparently forms a highly concentrated salt solution by absorbing moisture from the glovebox atmosphere. Rapid corrosion is attributed to the ensuing salt-catalyzed reaction between plutonium and water. Experimental results are discussed, possible involvement of hydrogen fluoride (HF) is examined, and methods of corrective action are presented in this report

Influence of chloride ion concentration on the electrochemical corrosion behaviour of plasma electrolytic oxidation coated AM50 magnesium alloy

International Nuclear Information System (INIS)

Liang, J.; Srinivasan, P. Bala; Blawert, C.; Dietzel, W.

2010-01-01

The electrochemical degradation of a silicate- and a phosphate-based plasma electrolytic oxidation (PEO) coated AM50 magnesium alloy obtained using a pulsed DC power supply was investigated using potentiodynamic polarisation and electrochemical impedance spectroscopy (EIS) in NaCl solutions of different chloride ion concentrations viz., 0.01 M, 0.1 M, 0.5 M and 1 M. The surface of the PEO coated specimens after 50 h of immersion/EIS testing was examined by optical microscopy and scanning electron microscopy. The results showed that the corrosion deterioration of PEO coated magnesium alloy in NaCl solutions was significantly influenced by chloride ion concentration. The silicate-based coating was found to offer a superior corrosion resistance to the magnesium substrate than the phosphate-based coatings in lower chloride ion concentration NaCl solutions (0.01 M and 0.1 M NaCl). On the other hand both these PEO coatings were found to be highly susceptible to localized damage, and could not provide an effective corrosion protection to Mg alloy substrate in solutions containing higher chloride concentrations (0.5 M and 1 M). The extent of localized damage was observed to be more with increase in chloride concentration in both the cases.

Effect of iron ions on corrosion of lithium in a thionyl chloride electrolytes

International Nuclear Information System (INIS)

Shirokov, A.V.; Churikov, A.V.

1999-01-01

The effect of the iron electrolyte addition on the growth rate of the passivating layer on lithium in the LiAlCl 4 1 M solution in thionyl chloride is experimentally studied. It is established, that kinetic curved in the first 10 hours of the Li-electrode contact with electrolyte are described by the equation, assuming mixed diffusion kinetic control over the corrosion process. It is shown that introduction of Fe 3+ into electrolyte causes increase in both ionic and electron conductivity constituents. Increase in the electron carrier concentration is the cause of lithium corrosion in the iron-containing thionyl chloride solutions [ru

Accumulation of dissolved gases at hydrophobic surfaces in water and sodium chloride solutions: Implications for coal flotation

Energy Technology Data Exchange (ETDEWEB)

Hampton, M.A.; Nguyen, A.V. [University of Queensland, Brisbane, Qld. (Australia). Division of Chemical Engineering

2009-08-15

Dissolved gases can preferentially accumulate at the hydrophobic solid-water interface as revealed by neutron reflectivity measurements. In this paper, atomic force microscopy (AFM) was used to examine accumulation of dissolved gases at a hydrophobic surface in water and sodium chloride solutions. The solvent-exchange method was used to artificially form gaseous domains accumulated at the interface suitable for AFM imaging. Smooth graphite surfaces were used as model surfaces to minimize the secondary effect of surface roughness on the imaging. The concentration of NaCl up to 1 M was found to have a negligible influence on the geometry and population of pre-existing nanobubbles, nanopancakes and nanobubble-nanopancake composites. The implications of the findings on coal flotation in saline water are discussed in terms of attraction between hydrophobic surfaces in water, bubble-particle attachment and hydrophobic coagulation between particles.

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

International Nuclear Information System (INIS)

Xu, Tianfu; Pruess, Karsten

2001-01-01

Understanding movement of saline sodium nitrate (NaNO 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 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 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 3 solutions, we also present a comparison of thermophysical properties of both salt solutions. We have implemented the functional thermophysical properties of NaNO 3 solutions into a new TOUGH2 equation-of-state module EWASG-NaNO 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 pressure and tortuosity. The

Properties of filmogen solutions and films of hafnium compounds

International Nuclear Information System (INIS)

Sviridova, A.I.

1986-01-01

Study on hafnium hydrolizing compound solutions, used for hafnium oxide homogeneous layer formation, is conducted. In particular, electric conductivity, acidity and refractive index were investigated depending on the sal on ether concentration and the storage time. Oxyhafnium nitrate, hafnium chloride in ethanol, dichlorodiethoxyhafnium, hafnium oxychloride were used as initial compounds. Hydrolysis of hafnium compounds in solution occurs partially; further process occurs in the thin layer on the optical element surface; final decomposition is performed under heat treatment. It is ascertained, that alcoholic-aqueous solutions of inorganic salts can be filmogen only at definite acidity, density and viscosity (1.33-2.5 cp.). It is also ascertained that refractive index values and transmission spectral boundary of coatings, produced from alkoxy compound solutions and from chloride salt solutions, are practically the same. Transmittance boundary in ultraviolet region of spectrum of oxide films produced from nitrate and chloride solutions, varies with the heating temperature increase differently

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.

Precursor preparation for Ca-Al layered double hydroxide to remove hexavalent chromium coexisting with calcium and magnesium chlorides

Science.gov (United States)

Zhong, Lihua; He, Xiaoman; Qu, Jun; Li, Xuewei; Lei, Zhiwu; Zhang, Qiwu; Liu, Xinzhong

2017-01-01

Al(OH)3 and Ca(OH)2 powders are co-ground to prepare a precursor which hydrates into a layered double hydroxide (LDH) phase by agitation in aqueous solution with target hexavalent chromium (Cr(VI)) at room temperature, to achieve an obvious improvement in removal efficiency of Cr(VI) through an easy incorporation into the structure. Although the prepared precursor transforms into LDH phases also when agitated in the solutions of calcium and magnesium chlorides, it incorporates Cr(VI) preferentially to the chloride salts when they coexist. The adsorption isotherm and kinetic studies show that the phenomena occurring on the Al-Ca precursor fit a pseudo-second-order kinetics with a Langmuir adsorption capacity of 59.45 mg/g. Besides, characterizations of the prepared precursor and the samples after adsorption are also performed by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), Transmission electron microscope (TEM) to understand the reason of the preferential incorporation of Cr(VI) to the coexisting chloride salts during the LDH phase formation. Ca-Al precursor (C3A) was agitated in a hexavalent chromium (Cr(VI)) solution to form Al-Ca-CrO4 LDH product. Ca-Al-CrO4 LDH phase occurred preferentially to Ca-Al-MCl2 LDH phases in the solutions of calcium and magnesium chlorides, it incorporates Cr(VI) preferentially to the chloride salts when they coexist.

Diffusion of aqueous solutions of ionic, zwitterionic, and polar solutes

Science.gov (United States)

Teng, Xiaojing; Huang, Qi; Dharmawardhana, Chamila Chathuranga; Ichiye, Toshiko

2018-06-01

The properties of aqueous solutions of ionic, zwitterionic, and polar solutes are of interest to many fields. For instance, one of the many anomalous properties of aqueous solutions is the behavior of water diffusion in different monovalent salt solutions. In addition, solutes can affect the stabilities of macromolecules such as proteins in aqueous solution. Here, the diffusivities of aqueous solutions of sodium chloride, potassium chloride, tri-methylamine oxide (TMAO), urea, and TMAO-urea are examined in molecular dynamics simulations. The decrease in the diffusivity of water with the concentration of simple ions and urea can be described by a simple model in which the water molecules hydrogen bonded to the solutes are considered to diffuse at the same rate as the solutes, while the remainder of the water molecules are considered to be bulk and diffuse at almost the same rate as pure water. On the other hand, the decrease in the diffusivity of water with the concentration of TMAO is apparently affected by a decrease in the diffusion rate of the bulk water molecules in addition to the decrease due to the water molecules hydrogen bonded to TMAO. In other words, TMAO enhances the viscosity of water, while urea barely affects it. Overall, this separation of water molecules into those that are hydrogen bonded to solute and those that are bulk can provide a useful means of understanding the short- and long-range effects of solutes on water.

Cerium(terbium, erbium)chloride-choline chloride aqueous systems

International Nuclear Information System (INIS)

Gajfutdinova, R.K.; Zhuravlev, E.F.; Bikbaeva, G.G.; Domrachev, V.N.; Vanskova, G.I.

1985-01-01

To clarify the effect of rare earth nature on mutual solubility of rare earth salts and amines the solubility of solid phases in the systems, consisting of choline chloride, water and cerium, terbium, erbium chlorides, has been studied. It is established, that solubility isotherms of all the systems, testify to the formation of new solid phases of the composition: Ce(Tb, Er)xCl 3 x2C 5 H 14 ONClx3H 2 O. Individuality of new solid phases is proved by DTA method, the composition is confirmed by chemical analysis and data of PMR spectra, for choline chloride and its complexes with rare earth chlorides of the given composition PMR and IR spectra are studied

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.

Pitting Corrosion Behaviour of New Corrosion-Resistant Reinforcement Bars in Chloride-Containing Concrete Pore Solution.

Science.gov (United States)

Jiang, Jin-Yang; Liu, Yao; Chu, Hong-Yan; Wang, Danqian; Ma, Han; Sun, Wei

2017-08-04

In this study, the pitting behaviour of a new corrosion-resistant alloy steel (CR) is compared to that of low-carbon steel (LC) in a simulated concrete pore solution with a chloride concentration of 5 mol/L. The electrochemical behaviour of the bars was characterised using linear polarisation resistance (LPR) and electrochemical impedance spectroscopy (EIS). The pitting profiles were detected by reflective digital holographic microscopy (DHM), scanning electron microscopy (SEM), and the chemical components produced in the pitting process were analysed by X-ray energy dispersive spectroscopy (EDS). The results show that the CR bars have a higher resistance to pitting corrosion than the LC bars. This is primarily because of the periodic occurrence of metastable pitting during pitting development. Compared to the pitting process in the LC bars, the pitting depth grows slowly in the CR bars, which greatly reduces the risk of pitting. The possible reason for this result is that the capability of the CR bars to heal the passivation film helps to restore the metastable pits to the passivation state.

Allene functionalization via bicyclic methylene aziridines.

Science.gov (United States)

Boralsky, Luke A; Marston, Dagmara; Grigg, R David; Hershberger, John C; Schomaker, Jennifer M

2011-04-15

The oxidative functionalization of olefins is a common method for the formation of vicinal carbon-heteroatom bonds. However, oxidative methods to transform allenes into synthetic motifs containing three contiguous carbon-heteroatom bonds are much less developed. This paper describes the use of bicyclic methylene aziridines (MAs), prepared via intramolecular allene aziridination, as scaffolds for functionalization of all three allene carbons. © 2011 American Chemical Society

Behavior of uranium during the formation of granitic magma by anatexis (I). Influence of redox conditions and the presence of chloride on the solubility of uranium in the hydrothermal solutions

International Nuclear Information System (INIS)

Satoru Nakashima; Toshimichi Iiyama, J.

1983-01-01

The behavior of uranium is examined experimentally in the course of partial fusion of natural or synthetic granitic rocks. Uranium is definitely soluble in the associated hydrothermal solutions containing chloride under oxidizing conditions, but it is not soluble in the same fluids under reducing conditions [fr

The preparation and certification of zirconyl chloride CRM-inhouse from process result of zircon mineral

International Nuclear Information System (INIS)

Samin; Sajimo; Supriyanto; Isman Mulyadi T

2015-01-01

The preparation and certification of the zirconyl chloride certified reference material (CRM) has been carried out from the row material of the zircon mineral. The zircon mineral was processing in the Feeder with the velocity of 17 kg/hour and produced the zircon concentrate. The zircon concentrate was mixed with NaOH, NaF, Na 2 CO 3 and H 2 O. The mixture was melted in the Furnace at 750°C for 2 hours. The results of molten was pressed with aquadest and then was participated for 24 hours. The solid was separated from the filtrate, and then it was dried in the Oven at 105°C for 3 hours, those result was called sodium zirconate. Sodium zirconate was leaching with HCl, it was found the zirconyl chloride solution and then was evaporated it was found the zirconyl chloride concentrated solution. This solution was crystallized, then obtained the zirconyl chloride crystal. It was washed with ethanol, so retrieved the crystal white zirconyl chloride. The crystal white zirconyl chloride was dried in the Oven at 90°C, it was crushed with stainless steel powder and sieved to 200 mesh of the particle size. The crystal white zirconyl chloride was stirred up to homogenous in the Homogenizer. Next was treated the homogenization and the stabilisation testing with statistically method. Zirconyl chloride crystals was standardized by using standard ZrOCl 2 8 H 2 O made in E. Merck, were include the chemical compounds test with XRD Spectrometry, the composition the content of crystals and the specific gravity. From the evaluation of the homogenization and stabilisation testing, the crystal zirconyl chloride was homogeneous, stable and it was fulfil to physically behavior as CRM. Compared with the standard zirconyl chloride, ZrOCl 2 8 H 2 O, the XRD spectra and chemical composition (96,263%), the content of crystals (98,625%). and specific gravity (97,190%) of the zirconyl chloride crystal were nearly same respectively. Certificate of the parameters testing results in the CRM the

Novel methylene-blue-sensitized photopolymers for holographic recording: a comparison

Science.gov (United States)

Ushamani, Mythili; Sreekumar, K.; Sudha Kartha, C.; Joseph, Rani

2004-06-01

Polymer matrices like PVC and a blend of PVA/PAA is introduced as new holographic media that cause red sensitivity with methylene blue. Unlike methylene blue sensitized polymers like PVA, PMMA, gelatin etc, the change of state occurring for methylene blue on laser irradiation on PVC matrix was found to be permanent. No recovery of dye on the irradiated spot was observed on storage. The outstanding properties of this material are its excellent optical clarity, insensitive to humidity, economical, ease of fabrication, absence of dark room storage etc. The recovery of dye in conventional MBPVA matrix can be delayed by blending PVA with PAA. Optimization of the ratio of PVA/PAA, the sensitizer concentration, pH, energy, diffraction efficiency measurements etc are done. pH is found to have a great influence on the recovery of the dye in this matrix. The effect of monomers in improving the diffraction efficiency on these dye doped polymer system is also evaluated. A comparative study is done on these polymer matrices and holographic gratings were recorded on these films from a He- Ne laser operating at 632.8 nm.

Application of natural dyes in textile industry and the treatment of dye solutions using electrolytic techniques

OpenAIRE

Abouamer, Karima Massaud

2008-01-01

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University, 25/02/2008. Anodic oxidation of a commercial dye, methylene blue (MB), from aqueous solutions using an electrochemical cell is reported. Data are provided on the effects of eight different types of supporting electrolytes, concentration of electrolytes, initial dye concentration, current and electrolytic time on the percentage removal of methylene blue. Anodic oxidation was found to be effect...

P25-graphene hydrogels: room-temperature synthesis and application for removal of methylene blue from aqueous solution.

Science.gov (United States)

Hou, Chengyi; Zhang, Qinghong; Li, Yaogang; Wang, Hongzhi

2012-02-29

Herein we report a room-temperature synthesis of chemically bonded TiO2 (P25)-graphene composite hydrogels and their use as high performance visible light photocatalysts. The three-dimensional (3D) TiO2-carbon composite exhibits a significant enhancement in the reaction rate in the decontamination of methylene blue, compared to the bare P25. The 3D P25-graphene hydrogel is much easier to prepare and apply as a macroscopic device, compared to the 2D P25-graphene sheets. This work could provide new insights into the room-temperature synthesis of graphene-based materials. As a kind of the novel 3D graphene-based composite, the obtained high performance P25-graphene gel could be widely used in the environmental protection issues. Copyright © 2012. Published by Elsevier B.V.

ON THE CHEMISTRY AND STAINING PROPERTIES OF CERTAIN DERIVATIVES OF THE METHYLENE BLUE GROUP WHEN COMBINED WITH EOSIN

Science.gov (United States)

Wilson, Thomas M.

1907-01-01

1. Eosinate of thionin gives very satisfactory staining for blood smears. It is easily prepared and dissolves readily in methylated spirits. 2. In the methods heretofore employed for making mixtures of eosin and methylene blue derivatives, the eosinates of methylene violet and methylene azure are present in very small quantities or are altogether absent. 3. Thionol and thionin are probably formed in methylene blue which has been long boiled with dilute alkalies and silver oxide. 4. Good stains of eosin and methylene blue derivatives can be obtained by a variety of manipulations. 5. Methylated spirits is more economical as a solvent for this stain and better adapted for the simple technique above described than is methyl alcohol. There is some evidence that the staining act is of a chemical nature. PMID:19867116

Electrolytic production of light lanthanides from molten chloride alloys on a large laboratory scale

International Nuclear Information System (INIS)

Szklarski, W.; Bogacz, A.; Strzyzewska, M.

1979-01-01

Literature data relating to electrolytic production of rare earth metals are presented. Conditions and results are given of own investigations into the electrolytic process of light lanthanide chloride solutions (LA-Nd) in molten potassium and sodium chlorides conducted on a large laboratory scale using molybdenic, iron, cobaltic and zinc cathodes. Design schemes of employed electrolysers are enclosed. (author)

Impact of chloride on the mineralogy of hydrated Portland cement systems

International Nuclear Information System (INIS)

Balonis, Magdalena; Lothenbach, Barbara; Le Saout, Gwenn; Glasser, Fredrik P.

2010-01-01

Chloride ion is in part bound into ordinary Portland cement paste and modifies its mineralogy. To understand this a literature review of its impacts has been made and new experimental data were obtained. Phase pure preparations of Friedel's salt, Ca 4 Al 2 (Cl) 1.95 (OH) 12.05 .4H 2 O, and Kuzel's salt, Ca 4 Al 2 (Cl)(SO 4 ) 0.5 (OH) 12 .6H 2 O, were synthesized and their solubilities were measured at 5, 25, 55 and 85 o C. After equilibration, solid phases were analysed by X-ray diffraction while the aqueous solutions were analysed by atomic absorption spectroscopy and ion chromatography. The solid solutions and interactions of Friedel's salt with other AFm phases were determined at 25 o C experimentally and by calculations. In hydrated cements, anion sites in AFm are potentially occupied by OH, SO 4 and CO 3 ions whereas Cl may be introduced under service conditions. Chloride readily displaces hydroxide, sulfate and carbonate in the AFm structures. A comprehensive picture of phase relations of AFm phases and their binding capacity for chloride is provided for pH ∼ 12 and 25 o C. The role of chloride in AFt formation and its relevance to corrosion of embedded steel are discussed in terms of calculated aqueous [Cl - ]/[OH - ] molar ratios.

A spectroscopic study of uranium species formed in chloride melts

International Nuclear Information System (INIS)

Volkovich, Vladimir A.; Bhatt, Anand I.; May, Iain; Griffiths, Trevor R.; Thied, Robert C.

2002-01-01

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)

Stability of oxaliplatin in chloride-containing carrier solutions used in hyperthermic intraperitoneal chemotherapy

NARCIS (Netherlands)

Mehta, A M; Van den Hoven, J M; Rosing, H; Hillebrand, M J X; Nuijen, B; Huitema, A D R; Beijnen, J H; Verwaal, V J

2015-01-01

PURPOSE: Oxaliplatin is increasingly becoming the chemotherapeutic drug of choice for the treatment of peritoneal malignancies using cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC). Oxaliplatin is unstable in chloride-containing media, resulting in the use of 5%

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

International Nuclear Information System (INIS)

Takigami, S.; Maeda, Y.; Nakamura, Y.

1979-01-01

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

A Ti-doped γ-Fe2O3/SDS nano-photocatalyst as an efficient adsorbent for removal of methylene blue from aqueous solutions.

Science.gov (United States)

Mirbagheri, Naghmeh Sadat; Sabbaghi, Samad

2018-05-01

Synthetic dyes are among the most important environmental pollutants in wastewaters. Consequently, elimination of the synthetic dyes from wastewaters using non-toxic materials and eco-friendly technologies has been of considerable interests. In this study, magnetically separable Ti-doped γ-Fe 2 O 3 photocatalysts were synthesized for the removal of methylene blue (MB) from a dye-contaminated aqueous solution (as a model of dye-polluted wastewaters). Compared to the pristine γ-Fe 2 O 3 , the 1.78 v% Ti-doped γ-Fe 2 O 3 significantly increased the adsorption of MB by 57% in the dark condition as a result of the improved BET surface area in this photocatalyst. Moreover, the contact time required for the photocatalytic degradation of MB by the 1.78 v% Ti-doped γ-Fe 2 O 3 decreased due to the higher concentration of charge carriers in this photocatalyst than that of the pristine γ-Fe 2 O 3 . The effect of different experimental parameters on the adsorption property and photocatalytic activity of the 1.78 v% Ti-doped γ-Fe 2 O 3 photocatalyst showed that the solution pH had a remarkable influence on the removal performance of this photocatalyst. Surface treatment of the 1.78 v% Ti-doped γ-Fe 2 O 3 with sodium dodecyl sulfate (SDS) resulted in the formation of a negatively charged Ti-doped γ-Fe 2 O 3 /SDS photocatalyst, which showed a higher tendency for the adsorption and removal of MB than the untreated photocatalyst. Moreover, the MB removal efficiency of this photocatalyst was among the best performances that have been reported for the γ-Fe 2 O 3 -based photocatalysts. The synthesized photocatalysts were characterized by various techniques, and a plausible mechanism for the removal of MB from aqueous solutions by the Ti-doped γ-Fe 2 O 3 /SDS photocatalyst was purposed. Copyright © 2018 Elsevier Ltd. All rights reserved.

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

International Nuclear Information System (INIS)

Stefec, R.; Franz, F.; Holecek, A.

1979-01-01

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 750 0 C 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) [de

Evaluation Technique of Chloride Penetration Using Apparent Diffusion Coefficient and Neural Network Algorithm

Directory of Open Access Journals (Sweden)

Yun-Yong Kim

2014-01-01

Full Text Available Diffusion coefficient from chloride migration test is currently used; however this cannot provide a conventional solution like total chloride contents since it depicts only ion migration velocity in electrical field. This paper proposes a simple analysis technique for chloride behavior using apparent diffusion coefficient from neural network algorithm with time-dependent diffusion phenomena. For this work, thirty mix proportions of high performance concrete are prepared and their diffusion coefficients are obtained after long term-NaCl submerged test. Considering time-dependent diffusion coefficient based on Fick’s 2nd Law and NNA (neural network algorithm, analysis technique for chloride penetration is proposed. The applicability of the proposed technique is verified through the results from accelerated test, long term submerged test, and field investigation results.

Chloride content of solutions used for regional citrate anticoagulation might be responsible for blunting correction of metabolic acidosis during continuous veno-venous hemofiltration.

Science.gov (United States)

Jacobs, Rita; Honore, Patrick M; Diltoer, Marc; Spapen, Herbert D

2016-08-26

Citrate, the currently preferred anticoagulant for continuous veno-venous hemofiltration (CVVH), may influence acid-base equilibrium. The effect of 2 different citrate solutions on acid-base status was assessed according to the Stewart-Figge approach in two consecutive cohorts of critically ill adult patients. The first group received Prismocitrate 10/2 (PC10/2; 10 mmol citrate/L). The next group was treated with Prismocitrate 18/0 (PC18; 18 mmol citrate/L). Both groups received bicarbonate-buffered fluids in post-dilution. At similar citrate flow, the metabolic acidosis present at baseline in both groups was significantly attenuated in PC18 patients but persisted in PC10/2 patients after 24 h of treatment (median pH 7,42 vs 7,28; p = 0.0001). Acidosis in the PC10/2 group was associated with a decreased strong ion difference and an increased strong ion gap (respectively 43 vs. 51 mmol/L and 17 vs. 12 mmol/L, PC10/2 vs. PC18; both p = 0.001). Chloride flow was higher in PC10/2 than in PC18 subjects (25.9 vs 14.3 mmol/L blood; p < 0.05). Correction of acidosis was blunted in patients who received 10 mmol citrate/L as regional anticoagulation during CVVH. This could be explained by differences in chloride flow between the applied citrate solutions inducing hyperchloremic acidosis.

Novel methylene bridged ethylenediamine-type ligands: Synthesis and spectral characterization

Directory of Open Access Journals (Sweden)

Mihajlović-Lalić Ljiljana E.

2014-01-01

Full Text Available Herein we report the synthesis of two new organic compounds, diisobutyl- and diisopentyl N,N′-methylene-(S,S-ethylenediamine-N,N′-di-2-(3-cyclohexylpropanoate. A one-pot procedure was carried out by adding the reducing agent and carbonyl compound into the methanol solution of the parent compounds (iso-butyl and iso-pentyl esters of (S,S-ethylenediamine-N,N′-di-2-(3-cyclohexylpropanoic acid in appropriate stoichiometric ratios. The compounds were fully characterized by infrared, ESI-MS, 1D (1H, 13C and 2D (COSY, HSQC, HMBC NMR spectroscopy and elemental analysis. The spectral data confirm the presence of -CH2- group introduced between nitrogen atoms of the ethylenediamine moiety revealing neutral form of potential bidentate ligand. [Projekat Ministarstva nauke Republike Srbije, br. 172035. The authors also acknowledge the support of the FP7 RegPot project FCUB ERA GA No. 256716. The EC does not share responsibility for the content of the article

Reverse osmosis separation of radium from dilute aqueous solutions

International Nuclear Information System (INIS)

Subramanian, K.S.; Sastri, V.S.

1980-01-01

Porous cellulose acetate membranes obtained from Osmonics Inc. were characterized in terms of pure water permeability constant, solute transport parameter, and mass transfer coefficient with aqueous sodium chloride solution as the reference system. Reverse osmosis separation behavior of radium-226 as nitrate, chloride, and sulfate salts was studied. Reverse osmosis method of removing radium-226 from aqueous solutions has been compared with other methods, and it has been shown to be one of the best methods for alleviating radium contamination problems

Simulation of chloride transport based description soil structure

International Nuclear Information System (INIS)

Mahmood-ul-Hassan, M.; Akhtar, M.S.; Gill, S.M.; Nabi, G.

2003-01-01

There is a need of environmental implications of rapid appearance of surface by applying chemical at depths below the vadose zone (tile line or shallow groundwater) for developing better insight into solute flow mechanism through the arable lands. Transport of chloride, a representative non-adsorbing solute, through a moderately structured silty clay loam soil (Gujranwala series, Typic Ustochrepts) and an un-structured sandy loam soil (Nabipur series, Typic Camborthid) was characterized and two existing models viz. convection dispersion equation (CDE) and preferential flow models were tested. The flux average of solute concentration in the outflow as a function of cumulative drainage was fitted to the models. The CDE fitted, relatively, better in the non-structured soil than in the moderately structured soil. Dispersivity value determined by CDE was very high for the structured soil which is physically not possible. The preferential flow model fitted well in the Gujranwala soil, but not in the Nabipur soil. The breakthrough characteristics i.e. drainage to peak concentration (Dp), symmetry coefficient (SC), skewness, and kurtosis were compared. Chloride breakthrough was earlier than expected based on piston flow. It indicated preferential flow in both the soils, yet, immediate appearance of the tracer in the Gujranwala soil demonstrated even larger magnitude of the preferential flow. Breakthrough curves' parameters indicated a large amount of the solute movement through the preferred pathways by passing the soil matrix in the Gujranwala soil. The study suggests that some soil structure parameters (size/shape and degree of aggregation) should be incorporated in the solute transport models.(author)

Non-covalent interactions between {N,N′-bis[(2-pyridinyl)methylene]-1, 2-benzenediamine]-bis(nitrato)}Cu(II) with pyridoxine hydrochloride in methanol at T = (298.15, 308.15 and 318.15) K

International Nuclear Information System (INIS)

Brahman, Dhiraj; Sinha, Biswajit

2014-01-01

Highlights: • Methanolic solution of pyridoxine hydrochloride used as solvent. • {N,N′-bis[(2-pyridinyl)methylene]-1, 2-benzenediamine]-bis(nitrato)}Cu(II) used as solute. • Partial molar volumes and viscosity B-coefficients of the solute were determined. • Weak 1:1 association between the complex and pyridoxine hydrochloride found. • Non-covalent interactions and Cu(II) complex acts as a net structure maker in the ternary solutions. - Abstract: Non-covalent interactions between of {N,N′-bis[(2-pyridinyl)methylene]-1, 2-benzenediamine]-bis(nitrato)}Cu(II) with pyridoxine hydrochloride in methanol were investigated by a combination of physico-chemical and spectrophotometric methods at T = (298.15, 308.15 and 318.15) K under ambient pressure. From measured density and viscosity data the apparent molar volume (ϕ V ), the slope (S V ∗ ), standard partial molar volume (ϕ V 0 ), standard transfer volume (Δ t ϕ V 0 ), isobaric apparent molar expansibility (ϕ E ), standard isobaric partial molar expansibility (ϕ E 0 ), the viscosity B-coefficient, its temperature derivative (∂B/∂T), solvation number (S n ) were calculated and discussed on the basis of specific or non-specific (solute + cosolute) and (solute + solvent) interactions. Thermodynamics of viscous flow were discussed on the basis of the transition state theory. Spectrophotometric results indicated 1:1 (solute + cosolute) interaction between the complex and pyridoxine hydrochloride

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

NARCIS (Netherlands)

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

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

Effects of postexsanguination vascular infusion of cattle with a solution of saccharides, sodium chloride, phosphates, and vitamins C, E, or C+E on meat display-color stability.

Science.gov (United States)

Yancey, E J; Hunt, M C; Dikeman, M E; Addis, P B; Katsanidis, E

2001-10-01

Grain-finished, high-percentage Charolais steers (n = 36) were selected for uniformity. Immediately after jugular vein exsanguination, 27 steers were infused at 10% of live weight via the carotid artery with a solution developed by MPSC, Inc. (St. Paul, MN) consisting of 98.52% water, 0.97% saccharides, 0.23% sodium chloride, and 0.28% phosphate blend plus either 500 ppm vitamin C (MPSC+C; n = 9), 500 ppm vitamin E (MPSC+E; n = 9), or 500 ppm vitamin C + 500 ppm vitamin E (MPSC+C+E; n = 9). Uninfused controls (CON) were exsanguinated conventionally. Carcasses were fabricated at 48 h postmortem. Longissimus thoracis (LT), psoas major (PM), and semimembranosus (SM) muscles were removed, vacuum-packaged, and stored at 2 degrees C until 14 d postmortem. Then, steaks 2.54 cm thick were sliced from the three muscles, placed on foam trays, and overwrapped with polyvinyl chloride film. Ground beef (GB) was formulated from the quadriceps femoris to contain 20% fat, mounded into 0.45-kg portions, placed on styrofoam trays, and wrapped with polyvinyl chloride film. Steaks were visually evaluated for uniformity and initial color on display d 0. Instrumental color measurements of L*, a*, b* and trained sensory panel color evaluations were obtained daily for 4 d (PM and GB) or 5 d (LT and SM) of display. No display time x treatment interaction existed for L*, a*, or b* values. The LT from CON cattle had more uniform color (P cherry red than that from all infused cattle on d 0. Visual scores indicated that GB from MPSC+E cattle was more red (P < 0.05) than that from MPSC+C infused cattle throughout display, and GB from MPSC+E cattle was more red (P < 0.05) than that from CON cattle for the last 3 d of display. The vascular infusion solutions generally did not improve color or display-color stability of steaks, but the infusion solution with vitamin E did improve display-color stability of GB.

The influence of nitrogen - urea fertilization to leaves and chloride chlorocholine on the accumulation Cs-137 in spring wheat crops

International Nuclear Information System (INIS)

Hrynczuk, B.; Weber, R.

1998-01-01

In pot experiments were studied effects of using nitrogen urea solution to leaves and use chloride chlorocholine on the Cs-137 accumulation in spring wheat crops. The Cs-137 contamination was conducted from soil and through leaves. It has been found that use nitrogen fertilization as urea solution spray and in addition use chloride chlorocholine caused an increase of Cs-137 concentration in grain from the contaminated soil. Accumulation of Cs-137 in spring wheat grain is 2-4 times higher coming from the contaminated leaves in blooming phase in comparison to the grain of plants contaminated in spread phase. The urea solution fertilization used on leaves and addition chloride chlorocholine did not influence the Cs-137 accumulation in grain when the plants were contaminated in the early growing phase. The Cs-137 contamination brought on the plants after using chloride chlorocholine in subsequent growing phases passed early into spring wheat grain. (author)

The reduction of pertechnetate-99 by stannous chloride

International Nuclear Information System (INIS)

Steigman, J.; Meinken, G.; Richards, P.

1975-01-01

The reduction of pertechnetate-99 by excess stannous chloride in several media was investigated as a possible model for radiopharmaceutical preparations which are based on the reduction of pertechnetate-99m by the same reagent. Polarographic and iodimetric techniques were used to analyze for unreacted stannous ion. It was found that pertechnetate is reduced to the +4 state in a citrate buffer at pH7, to the +3 state in a DTPA buffer at pH4, and possibly to the +4 state in HCl. The reaction in DTPA solution was found to be complete within several minutes. The reduction in the citrate buffer proceeded rapidly to the +5 state, and much more slowly to the +4 state. The implications of these rate studies for the radiopharmaceutical preparations were discussed. Direct potentiometric titrations of pertechnetate-99 with stannous chloride showed that the technetium was in the +4 state in HCl, in the +5 state in citrate solution, and in both the +3 and +4 states in DTPA. (author)

Corneal edema and permanent blue discoloration of a silicone intraocular lens by methylene blue.

Science.gov (United States)

Stevens, Scott; Werner, Liliana; Mamalis, Nick

2007-01-01

To report a silicone intraocular lens (IOL) stained blue by inadvertent intraoperative use of methylene blue instead of trypan blue and the results of experimental staining of various lens materials with different concentrations of the same dye. A "blue dye" was used to enhance visualization during capsulorhexis in a patient undergoing phacoemulsification with implantation of a three-piece silicone lens. Postoperatively, the patient presented with corneal edema and a discolored IOL. Various IOL materials were experimentally stained using methylene blue. Sixteen lenses (4 silicone, 4 hydrophobic acrylic, 4 hydrophilic acrylic, and 4 polymethylmethacrylate) were immersed in 0.5 mL of methylene blue at concentrations of 1%, 0.1%, 0.01%, and 0.001%. These lenses were grossly and microscopically evaluated for discoloration 6 and 24 hours after immersion. The corneal edema resolved within 1 month after the initial surgical procedure. After explantation, gross and microscopic analyses of the explanted silicone lens revealed that its surface and internal substance had been permanently stained blue. In the experimental study, all of the lenses except the polymethylmethacrylate lenses were permanently stained by methylene blue. The hydrophilic acrylic lenses showed the most intense blue staining in all dye concentrations. This is the first clinicopathological report of IOL discoloration due to intraocular use of methylene blue. This and other tissue dyes may be commonly found among surgical supplies in the operating room and due diligence is necessary to avoid mistaking these dyes for those commonly used during ocular surgery.

Experimental investigation on the threshold chloride concentration for corrosion initiation in reinforced concrete structures

International Nuclear Information System (INIS)

Byung Hwan Oh; Seung Yup Jang

2005-01-01

The corrosion of steel reinforcements in concrete is of great importance in the view of safety and durability of reinforced concrete structures. This study is focused on the corrosion behavior of steel bars induced by internal chlorides in concrete. The main objective of this study is to determine the threshold chloride concentration causing depassivation and active corrosion of steel reinforcement in concrete. To examine the threshold concentration of chloride ion, the half-cell potential, the chemical composition of extracted pore solutions of concrete and the extent of corroded area of the specimens were measured. Major test variables include the added amount of chlorides in concrete, type of binder, and water-to-binder ratios. From the present comprehensive test results, the factors influencing threshold chloride concentration are investigated, and the rational ranges of threshold chloride concentration causing active corrosion of steels are proposed. The present study provides the realistic chloride limit for corrosion initiation of reinforced concrete structures, which can be used efficiently in the future technical specification. (authors)

Effect of potassium chloride on diffusion of theophylline at T = 298.15 K

Energy Technology Data Exchange (ETDEWEB)

Santos, Cecilia I.A.V., E-mail: cecilia.alves@uah.e [Departamento de Quimica Fisica, Facultad de Farmacia, Universidad de Alcala, 28871 Alcala de Henares, Madrid (Spain); 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); Ribeiro, Ana C.F., E-mail: anacfrib@ci.uc.p [Department of Chemistry, University of Coimbra, 3004-535 Coimbra (Portugal)

2011-06-15

Research highlights: {yields} Mutual diffusion coefficients of theophylline in aqueous dilute solutions. {yields} Influence of the presence of potassium chloride in the aqueous media. {yields} Estimation of the association constant, K, between THP and KCl. - Abstract: Ternary mutual diffusion coefficients measured by Taylor dispersion method (D{sub 11}, D{sub 22}, D{sub 12}, and D{sub 21}) are reported for aqueous solutions of KCl + theophylline (THP) at T = 298.15 K at carrier concentrations from (0.000 to 0.010) mol {center_dot} dm{sup -3}, for each solute. These diffusion coefficients have been measured having in mind a better understanding of the structure of these systems and the thermodynamic behavior of potassium chloride and theophylline in solution. For example, from these data it will be possible to make conclusions about the influence of this electrolyte in diffusion of THP and to estimate some parameters, such as the diffusion coefficient of the aggregate between KCl and THP.

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

International Nuclear Information System (INIS)

Hernandez H, K. A.

2012-01-01

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

Chloride ingress prediction

DEFF Research Database (Denmark)

Frederiksen, Jens Mejer; Geiker, Mette Rica

2008-01-01

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

Distribution of cadmium between calcium carbonate and solution, 2

International Nuclear Information System (INIS)

Kitano, Yasushi; Kanamori, Nobuko; Fujiyoshi, Ryoko

1978-01-01

The distribution coefficient of cadmium between calcite and solution has been measured in the calcium bicarbonate solution containing cadmium and chloride ions, which forms complexes with cadmium ions. It has been confirmed experimentally that cadmium carbonate is present as a solid solution between calcitic calcium carbonate and cadmium carbonate in the carbonate precipitate formed in the solution system. However, the constant value of the thermodynamic distribution coefficient of cadmium between calcite and solution has not been obtained experimentally in the calcium bicarbonate solution containing cadmium and chloride ions. It may have been caused by the very specific behavior of cadmium ions, but the exact reason remains unsolved and must be studied. (Kobatake, H.)

Penetration of chlorides in hardened concrete during frost salt scaling cycles

Directory of Open Access Journals (Sweden)

Moral N.

2010-06-01

Full Text Available Sixty samples from three concrete mixes (same components were prepared and subjected to frost salt scaling cycles. A set of 20 samples from the same mix was tested according to the French standard XP P18-420. Another set was exposed to different chloride concentrations. Different numbers of freeze/thaw cycles were applied to the last set. The mass of scaled-off particles follows a lognormal distribution. Despite high standard deviation, this scaling test enables to separate high resistant from very low resistant concrete. A combined analysis reveals that the scaling and the chloride penetration front are independent from a phenomenological point of view and that the chloride concentration on the exposed surface directly influences the amount of scaled mass according to the typical pessimum effect. These results raise two main questions: is the amount of chloride on the surface solution a direct or indirect parameter and what happens to this pessimum effect if we take into account the scaling test dispersion?

29 CFR 1910.1052 - Methylene Chloride.

Science.gov (United States)

2010-07-01

..., erythema, cracked skin, or skin burns; and cardiac effects such as chest pain or shortness of breath. This... treatment and decontamination of the exposed employee; (ii) Comprehensive physical examination with special... good solvent for oils, fats, waxes, resins, bitumen, rubber and cellulose acetate and is a useful paint...

Chloride adsorption by calcined layered double hydroxides in hardened Portland cement paste

International Nuclear Information System (INIS)

Yoon, Seyoon; Moon, Juhyuk; Bae, Sungchul; Duan, Xiaonan; Giannelis, Emmanuel P.; Monteiro, Paulo M.

2014-01-01

This study investigated the feasibility of using calcined layered double hydroxides (CLDHs) to prevent chloride-induced deterioration in reinforced concrete. CLDHs not only adsorbed chloride ions in aqueous solution with a memory effect but also had a much higher binding capacity than the original layered double hydroxides (LDHs) in the cement matrix. We investigated this adsorption in hardened cement paste in batch cultures to determine adsorption isotherms. The measured and theoretical binding capacities (153 mg g −1 and 257 mg g −1 , respectively) of the CLDHs were comparable to the theoretical capacity of Friedel's salt (2 mol mol −1 or 121 mg g −1 ), which belongs to the LDH family among cementitious phases. We simulated chloride adsorption by CLDHs through the cement matrix using the Fickian model and compared the simulation result to the X-ray fluorescence (XRF) chlorine map. Based on our results, it is proposed that the adsorption process is governed by the chloride transport through the cement matrix; this process differs from that in an aqueous solution. X-ray diffraction (XRD) analysis showed that the CLDH rebuilds the layered structure in a cementitious environment, thereby demonstrating the feasibility of applying CLDHs to the cement and concrete industries. - Highlights: • We examine the adsorption equilibrium and kinetics of CLDH in the hydrated cement. • CLDH capacity to bind chloride ions in the hydrated cement paste is determined. • We model chloride adsorption by CLDH through the cement matrix. • CLDH reforms the layered structure with ion adsorption in the cement matrix

A nonradioactive assay for poly(a)-specific ribonuclease activity by methylene blue colorimetry.

Science.gov (United States)

Cheng, Yuan; Liu, Wei-Feng; Yan, Yong-Bin; Zhou, Hai-Meng

2006-01-01

A simple nonradioactive assay, which was based on the specific shift of the absorbance maximum of methylene blue induced by its intercalation into poly(A) molecules, was developed for poly(A)-specific ribonuclease (PARN). A good linear relationship was found between the absorbance at 662 nm and the poly(A) concentration. The assay conditions, including the concentration of methylene blue, the incubation temperature and time, and the poly(A) concentration were evaluated and optimized.

A mathematical model of a lithium/thionyl chloride primary cell

Science.gov (United States)

Evans, T. I.; Nguyen, T. V.; White, R. E.

1987-08-01

A 1-D mathematical model for the lithium/thionyl chloride primary cell was developed to investigate methods of improving its performance and safety. The model includes many of the components of a typical lithium/thionyl chloride cell such as the porous lithium chloride film which forms on the lithium anode surface. The governing equations are formulated from fundamental conservation laws using porous electrode theory and concentrated solution theory. The model is used to predict 1-D, time dependent profiles of concentration, porosity, current, and potential as well as cell temperature and voltage. When a certain discharge rate is required, the model can be used to determine the design criteria and operating variables which yield high cell capacities. Model predictions can be used to establish operational and design limits within which the thermal runaway problem, inherent in these cells, can be avoided.

Evidence of mass exchange between inside and outside of sonoluminescing bubble in aqueous solution of terbium chloride

Energy Technology Data Exchange (ETDEWEB)

Liang, Jinfu, E-mail: liang.shi2007@163.com [School of Physics and Electronic Science, Guizhou Normal University, Guiyang 550001 (China); Chen, Weizhong, E-mail: wzchen@nju.edu.cn [The Key Laboratory of Modern Acoustics, Ministry of Education, Institution of Acoustics, Nanjing University, Nanjing 210093 (China); Wang, Xun; Yang, Jing; Chen, Zhan [The Key Laboratory of Modern Acoustics, Ministry of Education, Institution of Acoustics, Nanjing University, Nanjing 210093 (China)

2016-12-16

Highlights: • Time-resolved spectra of SBSL were obtained for Tb{sup 3+} ions emission lines. • Mass exchange between inside and outside of SL bubble was probed via Tb{sup 3+} ions lines. • The argon rectification hypothesis was tested by time-resolved spectra of SBSL. • The rate of mass exchange inside an SBSL bubble increases with increasing sound pressure. - Abstract: Spectra of single-bubble sonoluminescence (SBSL) were obtained for Tb{sup 3+} ions emission lines from bubbles in an aqueous solution of terbium chloride (TbCl{sub 3}). The spectra provide experimental evidence to prove that an air bubble driven by strong ultrasound will not eventually become a rectified pure argon bubble, which is not as predicted by the argon rectification hypothesis. The time-resolved spectra of SBSL show a mass exchange of material such as Tb{sup 3+} ions between the inside and outside of the bubble. With increasing sound pressure, the rate of mass exchange and the SBSL intensity increases.

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

Energy Technology Data Exchange (ETDEWEB)

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

2014-03-24

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

Chloride adsorption by calcined layered double hydroxides in hardened Portland cement paste

KAUST Repository

Yoon, Seyoon

2014-06-01

This study investigated the feasibility of using calcined layered double hydroxides (CLDHs) to prevent chloride-induced deterioration in reinforced concrete. CLDHs not only adsorbed chloride ions in aqueous solution with a memory effect but also had a much higher binding capacity than the original layered double hydroxides (LDHs) in the cement matrix. We investigated this adsorption in hardened cement paste in batch cultures to determine adsorption isotherms. The measured and theoretical binding capacities (153 mg g -1 and 257 mg g-1, respectively) of the CLDHs were comparable to the theoretical capacity of Friedel\\'s salt (2 mol mol-1 or 121 mg g-1), which belongs to the LDH family among cementitious phases. We simulated chloride adsorption by CLDHs through the cement matrix using the Fickian model and compared the simulation result to the X-ray fluorescence (XRF) chlorine map. Based on our results, it is proposed that the adsorption process is governed by the chloride transport through the cement matrix; this process differs from that in an aqueous solution. X-ray diffraction (XRD) analysis showed that the CLDH rebuilds the layered structure in a cementitious environment, thereby demonstrating the feasibility of applying CLDHs to the cement and concrete industries. © 2014 Published by Elsevier B.V. All rights reserved.

Methylene blue (cationic dye) adsorption into Salvadora persica ...

African Journals Online (AJOL)

Methylene blue (MB) is the most commonly used substance for dyeing cotton, wood and silk. On inhalation, it can cause difficulty in breathing, while on direct contact, it may cause permanent injury of the eyes of human and animals, burning sensations, nausea, worming, profuse sweating, mental confusion and ...

Determination of Critical Micellar Concentration of Homologous 2-Alkoxyphenylcarbamoyloxyethyl-Morpholinium Chlorides

Directory of Open Access Journals (Sweden)

Lenka Stopková

2018-05-01

Full Text Available The critical micellar concentrations of selected alkyloxy homologues of local anesthetic 4-(2-{[(2-alkoxyphenylcarbamoyl]oxy}ethylmorpholin-4-ium chloride with nc = 2, 4, 5, 6, 7, 8, and 9 carbons in alkyloxy tail were determined by absorption spectroscopy in the UV–vis spectral region with the use of a pyrene probe. Within the homologous series of the studied amphiphilic compounds, the ln(cmc was observed to be dependent linearly on the number of carbon atoms nc in the hydrophobic tail: ln(cmc = 0.705–0.966 nc. The Gibbs free energy, necessary for the transfer of the methylene group of the alkoxy chain from the water phase into the inner part of the micelle at the temperature of 25 °C and pH ≈ 4.5–5.0, was found to be −2.39 kJ/mol. The experimentally determined cmc values showed good correlations with the predicted values of the bulkiness of the alkoxy tail expressed as the molar volume of substituent R, as well as with the surface tension of the compounds.

Separation of cerium and fractionation of rare earths from mixed chlorides

International Nuclear Information System (INIS)

Silva Queiroz, C.A. da; Sood, S.P.; Abrao, A.

1982-01-01

The separation of cerium from rare earths chlorides solutions by precipitation with hydrogen peroxide/air/dil. ammonium hydroxide; purification of cerium; fractionation by ion exchange and analytical control of the process are presented. (A.R.H.) [pt

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

Directory of Open Access Journals (Sweden)

Gadang Priyotomo

2013-10-01

Full Text Available 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 pitting potential of Ni3(Si,Ti were lower than those of C276 alloy, which means that the pitting corrosion resistance of C276 alloy was higher than that of Ni3(Si,Ti.

A Green Alternative to Aluminum Chloride Alkylation of Xylene

Science.gov (United States)

Sereda, Grigoriy A.; Rajpara, Vikul B.

2007-01-01

An acutely less toxic 2-bromobutane is used to develop a simple graphite-promoted procedure of alkylation of p-xylene. It is further demonstrated that aluminum chloride is not required, the need for aqueous workup is eliminated, waste solutions are not produced and the multiple use of the catalyst is allowed.

Chloride Test

Science.gov (United States)

... metabolic acidosis ) or when a person hyperventilates (causing respiratory alkalosis ). A decreased level of blood chloride (called hypochloremia) ... disease , emphysema or other chronic lung diseases (causing respiratory ... metabolic alkalosis). An increased level of urine chloride can indicate ...

Assessing initial conditions for chloride transport across low-permeability argillaceous rocks, Wellenberg, Switzerland

International Nuclear Information System (INIS)

Waber, H.N.; Hobbs, M.Y.; Frape, S.K.

2013-01-01

Information about fluid evolution and solute transport in a low-permeability metamorphic rock sequence has been obtained by comparing chloride concentrations and chlorine isotope ratios of pore water, groundwater, and fluid inclusions. The similarity of δ 37 Cl values in fluid inclusions and groundwater suggests a closed-system evolution during the metamorphic overprint, and signatures established at this time appear to form the initial conditions for chloride transport after exhumation of the rock sequence. (authors)

Carbon and TiO_2 synergistic effect on methylene blue adsorption

International Nuclear Information System (INIS)

Simonetti, Evelyn Alves Nunes; Simone Cividanes, Luciana de; Campos, Tiago Moreira Bastos; Rossi Canuto de Menezes, Beatriz; Brito, Felipe Sales; Thim, Gilmar Patrocínio

2016-01-01

Due to its high efficiency, low cost and a simple operation, the adsorption process is an important and widely used technique for industrial wastewater treatment. Recent studies on the removal of artificial dyes by adsorption include a large number of adsorbents, such as: activated carbon, silicates, carbon nanotube, graphene, fibers, titanates and doped titanates. The carbon insertion in the TiO_2 structure promotes a synergistic effect on the adsorbent composite, improving the adsorption and the charge-transfer efficiency rates. However, there are few studies regarding the adsorption capacity of TiO_2/Carbon composites with the carbon concentration. This study evaluates the effect of carbon (resorcinol/formaldehyde) insertion on TiO_2 structure through the adsorption process. Adsorbents were prepared by varying the carbon weight percentages using the sol-gel method. The physicochemical properties of the catalysts prepared, such as crystallinity, particle size, surface morphology, specific surface area and pore volume were investigated. The kinetic study, adsorption isotherm, pH effect and thermodynamic study were examined in batch experiments using methylene blue as organic molecule. In addition, the effect of carbon phase on the adsorption capacity of TiO_2-carbon composite was deeply investigated. SEM micrographs showed that TiO_2 phase grows along the carbon phase and FT-IR results showed the presence of Ti−O−C chemical bonding. The experiments indicate that the carbon phase acted as a nucleation agent for the growth of TiO_2 during the sol-gel step, with a TiO_2 structure suitable for blue methylene adsorption, resulting in a material with large surface area and slit-like or wedge-shaped pores. Further experiments will show the best carbon concentration for methylene blue adsorption using a TiO_2 based material. - Highlights: • This article deals with the adsorption of methylene blue onto TiO_2-Carbon composite. • The sol-gel synthesis was efficient

Investigation of passivity and its breakdown on Fe3Al–Si and Fe3Al–Ge intermetallics in chloride-containing solution

International Nuclear Information System (INIS)

Rosalbino, F.; Carlini, R.; Parodi, R.; Zanicchi, G.; Scavino, G.

2014-01-01

Highlights: • Passivity and its breakdown on Fe 3 Al–Si and Fe 3 Al–Ge iron aluminides was investigated. • Investigation was performed in borate buffer solution with and without 100 mM KCl. • Polarization, potentiostatic transients and impedance measurements have been employed. • Results have been compared with those obtained on Fe 3 Al intermetallic. • Si and Ge improve the resistance to localized corrosion of Fe 3 Al. - Abstract: The passivity and passivity breakdown of Fe 3 Al–Si and Fe 3 Al–Ge iron aluminides were studied in borate buffer solution (pH 8.4) in the absence and presence of 100 mM KCl, performing potentiodynamic polarization, potentiostatic transients and electrochemical impedance spectroscopy (EIS) measurements complemented with scanning electron microscopy (SEM). In the absence of chloride ions Si and Ge exercise a beneficial role in the passivating characteristics of Fe 3 Al intermetallic. Addition of Si or Ge significantly modifies the electrochemical response of iron aluminide Fe 3 Al resulting in a more stable passive film. In the presence of chloride ions all the intermetallic compounds experience localized corrosion (pitting). However, Si and Ge alloying additions increase the breakdown potential and the extent of passivation domain, indicating improved resistance to initiation of pitting corrosion. Furthermore, EIS measurements performed at the breakdown state evidenced higher R ct and lower depression angle values for Fe 3 Al–Si and Fe 3 Al–Ge iron aluminides compared to Fe 3 Al intermetallic, confirming their better localized corrosion behavior. The improved resistance to pitting corrosion results from the enhanced protective function of passive film due to the presence of Si or Ge that inhibit pit initiation by hindering the adsorption of Cl − ions at the metal surface

Photodynamic action of the methylene blue: mutagenesis and sinergism

International Nuclear Information System (INIS)

Capella, M.A.M.

1988-01-01

Two aspects of photodynamic therapy were studied: the associated mutagenesis and the interactions with physical agents, in order to increase its biological effects. The photodynamic action with methylene blue in the mutagenesis and sinergism is studied. (L.M.J.)