Science.gov

Sample records for calcium chloride solutions

  1. Calcium chloride: a new solution for frozen coal

    SciTech Connect

    Boley, D.G.

    1984-01-01

    Proved in emergency situations as fast and economical, calcium chloride can be used in conjunction with other techniques for effective prevention of coal freezing. Calcium chloride solution depresses the freezing point, and should the temperature drop below this point, the ice that does form has a far lower compressive strength than ice normally exhibits.

  2. Calcinosis cutis following contact with calcium chloride solution.

    PubMed

    Lim, Penny P L; Kossard, Steven; Stapleton, Karen

    2012-11-01

    Calcinosis cutis is the deposition of insoluble calcium in the cutaneous tissue. Calcinosis cutis can be classified as metastatic, dystrophic, idiopathic or exogenous. We report a 48-year-old white man who was dismantling a portable ice skating rink when calcium chloride solution from the pipes spilt onto his clothing. Several days later, he started to develop mildly pruritic erythematous papules, some studded with white deposits and some with umbilication over the exposed areas corresponding to the spillage of the calcium chloride solution. Histological features revealed interstitial fibrohistiocytic reaction with calcium-encrusted degenerated collagen bundles in the dermis which was further confirmed by von Kossa stain. He was commenced on topical corticosteroid cream twice daily and the lesions cleared completely between 6 to 10 weeks.

  3. Calcinosis cutis following contact with calcium chloride solution.

    PubMed

    Lim, Penny P L; Kossard, Steven; Stapleton, Karen

    2012-11-01

    Calcinosis cutis is the deposition of insoluble calcium in the cutaneous tissue. Calcinosis cutis can be classified as metastatic, dystrophic, idiopathic or exogenous. We report a 48-year-old white man who was dismantling a portable ice skating rink when calcium chloride solution from the pipes spilt onto his clothing. Several days later, he started to develop mildly pruritic erythematous papules, some studded with white deposits and some with umbilication over the exposed areas corresponding to the spillage of the calcium chloride solution. Histological features revealed interstitial fibrohistiocytic reaction with calcium-encrusted degenerated collagen bundles in the dermis which was further confirmed by von Kossa stain. He was commenced on topical corticosteroid cream twice daily and the lesions cleared completely between 6 to 10 weeks. PMID:23157788

  4. Properties of a new liquid desiccant solution - Lithium chloride and calcium chloride mixture

    SciTech Connect

    Ertas, A.; Anderson, E.E.; Kiris, I. )

    1992-09-01

    Desiccants, broadly classified as solid and liquid desiccants, have the property of extracting and retaining moisture from air brought into contact with them. By using either type, moisture in the air is removed and the resulting dry air can be used for air-conditioning or drying purposes. Because of its properties, lithium chloride is the most stable liquid desiccant and has a large dehydration concentration (30% to 45%), but its cost is relatively high ($9.00-13.00 per kg). It is expected that lithium chloride will reduce the relative humidity to as low as 15%. Calcium chloride is the cheapest (45 cents per kg) and most readily available desiccant, but it has the disadvantage of being unstable depending on the air inlet conditions and the concentration of the desiccant in the solution. To stabilize calcium chloride and to decrease the high cost of lithium chloride, the two can be mixed in different weight combinations. The main objective of this research is to measure the physical properties of different combinations of this mixture such as density, viscosity, and vapor pressure which are necessary for analysis of heat and mass transfer in a packed tower desiccant-air contact system. The solubility of this new liquid desiccant under certain temperature-concentrations will also be studied.

  5. CALCIUM CHLORIDE PLANT LOOKING EAST. CALCIUM CHLORIDE BUILDING IN CENTER, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    CALCIUM CHLORIDE PLANT LOOKING EAST. CALCIUM CHLORIDE BUILDING IN CENTER, CALCIUM CHLORIDE STORAGE BUILDING ON RIGHT WITH SA (SODA ASH) BUILDING IN RIGHT BACKGROUND. - Solvay Process Company, Calcium Chloride Plant, Between Willis & Milton Avenues, Solvay, Onondaga County, NY

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

    PubMed

    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.

  7. Effect of calcium chloride solution immersion on surface hardness of restorative glass ionomer cements.

    PubMed

    Shiozawa, Maho; Takahashi, Hidekazu; Iwasaki, Naohiko; Uo, Motohiro

    2013-01-01

    The objective of this study was to evaluate the effect of the concentration of calcium chloride (CaCl2) solution on the surface hardness of restorative glass ionomer cements (GICs). Two high-viscosity GICs, Fuji IX GP and GlasIonomer FX-II, were immersed in several concentrations of CaCl2 solution for 1 day and 1 week. The immersed specimen surfaces were evaluated using microhardness testing, grazing incidence X-ray diffraction, and energy-dispersive X-ray spectroscopy. Immersion in a higher concentration of CaCl2 solution produced a greater increase in the surface hardness. No crystalline substance was observed on the immersed surface. Calcium ions were selectively absorbed in the matrix of the GIC surface after immersion. They reacted with the non-reacted carboxylic acid groups remaining in the cement matrix. These reactions were considered to cause an increase in the surface hardness of the GICs.

  8. Desorption of CO2 from low concentration monoethanolamine solutions using calcium chloride and ultrasound irradiation

    NASA Astrophysics Data System (ADS)

    Tanaka, Kosuke; Okawa, Hirokazu; Fujiwara, Tatsuo; Kato, Takahiro; Sugawara, Katsuyasu

    2015-07-01

    We developed an effective method for desorbing CO2 from low-concentration (0.2 mol/l) monoethanolamine (MEA) solutions using calcium chloride (CaCl2) and ultrasound irradiation at 25 °C. The proportion of CO2 desorbed from the MEA solution was calculated from the amount of CaCO3 generated and the amount of CO2 emitted. The proportion of CO2 desorbed from the MEA solution was much higher when CaCl2 was added than when CaCl2 was not added. We also characterized the CaCO3 that was generated when the solution was treated with ultrasound irradiation and when the solution was stirred. The CaCO3 particles produced were more homogeneous and smaller when ultrasound irradiation was applied than when the solution was stirred.

  9. The stability of calcium chloride ion pairs in aqueous solutions at temperatures between 100 and 360 degree C

    SciTech Connect

    Williams-Jones, A.E. ); Seward, T.M. )

    1989-02-01

    The speciation of calcium in chloride solutions has been investigated between 100 and 360{degree}C by measuring the solubility of AgCl in HCl-CaCl{sub 2} solutions in which chloride varies from 0.3 to 3.0 m and calcium is maintained constant at 0.1 m. Cumulative equilibrium formation constants of calcium chloride ion pairs were evaluated using a non-liner least squares procedure. Association constants of calcium chloride ion pairs from the data at 100{degree}C. However, at 150{degree}C the cumulative formation constants for CaCl{sup +} and CaCl{sup 0}{sub 2} are 0.85 and 1.73, respectively. The stability field for CaCl{sup +} decreases with increasing temperature, whereas that for CaCl{sup 0}{sub 2} increases sharply and at 360{degree}C K{sub 2} is 4.95 {center dot} 10{sup 4}. Higher order calcium chloride ion pairs either do not form or have stability fields too small to be detected by the methods used in this study. The neutral aqueous calcium chloride ion pair CaCl{sup 0}{sub 2} contributes significantly to calcium speciation in intermediate to high salinity hydrothermal solutions: at 250{degree}C, 50 mol percent of the calcium in a 1 m HCl solution occurs as CaCl{sup 0}{sub 2}. The effect of this ion pairing is to increase the pH stability limits and solubilities of calcium-bearing minerals in such solutions.

  10. CALCIUM CHLORIDE PLANT LOOKING EAST. CALCIUM CHLORIDE BUILDING ON LEFT, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    CALCIUM CHLORIDE PLANT LOOKING EAST. CALCIUM CHLORIDE BUILDING ON LEFT, CALCIUM CHLORIDE STORAGE BUILDING ON RIGHT OF CENTER WITH TOP OF SA (SODA ASH) BUILDING IN RIGHT BACKGROUND. - Solvay Process Company, Calcium Chloride Plant, Between Willis & Milton Avenues, Solvay, Onondaga County, NY

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

    NASA Astrophysics Data System (ADS)

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

    2015-05-01

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

  12. Stress corrosion cracking and life prediction evaluation of austenitic stainless steels in calcium chloride solution

    SciTech Connect

    Leinonen, H.

    1996-05-01

    The stress corrosion cracking (SCC) susceptibility of austenitic stainless steels (SS) in calcium chloride solutions was studied using a constant-load method. Initiation and propagation of stress corrosion cracks were examined using fractography. The distribution of cracks was classified. A physical cracking was introduced, and creep deformation measurements were performed. The steady-state strain rate obtained from the corrosion elongation curve (elongation-vs-time curve) showed a linear function of time to failure (t{sub f}). This implied that {var_epsilon}{sub ss} can be applied as a parameter for prediction of t{sub f}. Furthermore, {var_epsilon}{sub ss} below which no failure occurs within a laboratory time scale was estimated. Based on results obtained, the critical values of stress below which no SCC occurred were evaluated. Based upon creep measurements in a noncorrosive environment, the influence of environment on {var_epsilon}{sub ss} was more than fivefold. Cracking characteristics were divided into three categories according to the crack initiation distribution. Transgranular cracking predominated at relatively low {sigma} and {var_epsilon}{sub ss}.

  13. Petrographic evidence of calcium oxychloride formation in mortars exposed to magnesium chloride solution

    SciTech Connect

    Sutter, Lawrence . E-mail: cee@mtu.edu; Peterson, Karl . E-mail: cee@mtu.edu; Touton, Sayward . E-mail: cee@mtu.edu; Van Dam, Tom . E-mail: cee@mtu.edu; Johnston, Dan . E-mail: Dan.Johnston@state.sd.us

    2006-08-15

    Many researchers have reported chemical interactions between CaCl{sub 2} and MgCl{sub 2} solutions and hardened Portland cement paste. One potentially destructive phase reported in the literature is calcium oxychloride (3CaO.CaCl{sub 2}.15H{sub 2}O). In the past, limited numbers of researchers have reported identification of this phase by X-ray diffraction. In this work, petrographic evidence of oxychloride formation is presented based on optical microscopy, scanning electron microscopy and microanalysis. This evidence indicates that calcium oxychloride does form in mortars exposed to MgCl{sub 2} solutions.

  14. Ionic surfactant aggregates in saline solutions: sodium dodecyl sulfate (SDS) in the presence of excess sodium chloride (NaCl) or calcium chloride (CaCl(2)).

    PubMed

    Sammalkorpi, Maria; Karttunen, Mikko; Haataja, Mikko

    2009-04-30

    The properties of sodium dodecyl sulfate (SDS) aggregates in saline solutions of excess sodium chloride (NaCl) or calcium chloride (CaCl(2)) ions were studied through extensive molecular dynamics simulations with explicit solvent. We find that the ionic strength of the solution affects not only the aggregate size of the resulting anionic micelles but also their structure. Specifically, the presence of CaCl(2) induces more compact and densely packed micelles with a significant reduction in gauche defects in the SDS hydrocarbon chains in comparison with NaCl. Furthermore, we observe significantly more stable salt bridges between the charged SDS head groups mediated by Ca(2+) than Na(+). The presence of these salt bridges helps stabilize the more densely packed micelles.

  15. 21 CFR 184.1193 - Calcium chloride.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Calcium chloride. 184.1193 Section 184.1193 Food... Specific Substances Affirmed as GRAS § 184.1193 Calcium chloride. (a) Calcium chloride (CaCl2·2H2O, CAS Reg. No. 10035-04-8) or anhydrous calcium chloride (CaCl2, CAS Reg. No. 10043-52-4) may be...

  16. 21 CFR 184.1193 - Calcium chloride.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Calcium chloride. 184.1193 Section 184.1193 Food... Specific Substances Affirmed as GRAS § 184.1193 Calcium chloride. (a) Calcium chloride (CaCl2·2H2O, CAS Reg. No. 10035-04-8) or anhydrous calcium chloride (CaCl2, CAS Reg. No. 10043-52-4) may be...

  17. 21 CFR 184.1193 - Calcium chloride.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Calcium chloride. 184.1193 Section 184.1193 Food... Specific Substances Affirmed as GRAS § 184.1193 Calcium chloride. (a) Calcium chloride (CaCl2·2H2O, CAS Reg. No. 10035-04-8) or anhydrous calcium chloride (CaCl2, CAS Reg. No. 10043-52-4) may be...

  18. 21 CFR 582.1193 - Calcium chloride.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Calcium chloride. 582.1193 Section 582.1193 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1193 Calcium chloride. (a) Product. Calcium chloride. (b) Conditions of use. This...

  19. 21 CFR 582.6193 - Calcium chloride.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Calcium chloride. 582.6193 Section 582.6193 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Calcium chloride. (a) Product. Calcium chloride. (b) Conditions of use. This substance is...

  20. 21 CFR 582.1193 - Calcium chloride.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Calcium chloride. 582.1193 Section 582.1193 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1193 Calcium chloride. (a) Product. Calcium chloride. (b) Conditions of use. This...

  1. 21 CFR 582.6193 - Calcium chloride.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Calcium chloride. 582.6193 Section 582.6193 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Calcium chloride. (a) Product. Calcium chloride. (b) Conditions of use. This substance is...

  2. 21 CFR 582.6193 - Calcium chloride.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium chloride. 582.6193 Section 582.6193 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Calcium chloride. (a) Product. Calcium chloride. (b) Conditions of use. This substance is...

  3. 21 CFR 582.1193 - Calcium chloride.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium chloride. 582.1193 Section 582.1193 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1193 Calcium chloride. (a) Product. Calcium chloride. (b) Conditions of use. This...

  4. 7 CFR 58.434 - Calcium chloride.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Calcium chloride. 58.434 Section 58.434 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Material § 58.434 Calcium chloride. Calcium chloride, when used, shall meet the requirements of the...

  5. 7 CFR 58.434 - Calcium chloride.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Calcium chloride. 58.434 Section 58.434 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Material § 58.434 Calcium chloride. Calcium chloride, when used, shall meet the requirements of the...

  6. 7 CFR 58.434 - Calcium chloride.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Calcium chloride. 58.434 Section 58.434 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Material § 58.434 Calcium chloride. Calcium chloride, when used, shall meet the requirements of the...

  7. 21 CFR 582.6193 - Calcium chloride.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Calcium chloride. 582.6193 Section 582.6193 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Calcium chloride. (a) Product. Calcium chloride. (b) Conditions of use. This substance is...

  8. 7 CFR 58.434 - Calcium chloride.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Calcium chloride. 58.434 Section 58.434 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Material § 58.434 Calcium chloride. Calcium chloride, when used, shall meet the requirements of the...

  9. 21 CFR 582.1193 - Calcium chloride.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Calcium chloride. 582.1193 Section 582.1193 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1193 Calcium chloride. (a) Product. Calcium chloride. (b) Conditions of use. This...

  10. 7 CFR 58.434 - Calcium chloride.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Calcium chloride. 58.434 Section 58.434 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Material § 58.434 Calcium chloride. Calcium chloride, when used, shall meet the requirements of the...

  11. 21 CFR 582.6193 - Calcium chloride.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Calcium chloride. 582.6193 Section 582.6193 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Calcium chloride. (a) Product. Calcium chloride. (b) Conditions of use. This substance is...

  12. 21 CFR 582.1193 - Calcium chloride.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Calcium chloride. 582.1193 Section 582.1193 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1193 Calcium chloride. (a) Product. Calcium chloride. (b) Conditions of use. This...

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

    SciTech Connect

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

    2003-05-13

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

  14. 21 CFR 172.330 - Calcium pantothenate, calcium chloride double salt.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Calcium pantothenate, calcium chloride double salt..., calcium chloride double salt. The food additive calcium chloride double salt of calcium pantothenate may... information required by the Act, the following: (1) The name of the additive “calcium chloride double salt...

  15. 21 CFR 172.330 - Calcium pantothenate, calcium chloride double salt.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium pantothenate, calcium chloride double salt..., calcium chloride double salt. The food additive calcium chloride double salt of calcium pantothenate may... information required by the Act, the following: (1) The name of the additive “calcium chloride double salt...

  16. 21 CFR 172.330 - Calcium pantothenate, calcium chloride double salt.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Calcium pantothenate, calcium chloride double salt..., calcium chloride double salt. The food additive calcium chloride double salt of calcium pantothenate may... information required by the Act, the following: (1) The name of the additive “calcium chloride double salt...

  17. 21 CFR 172.330 - Calcium pantothenate, calcium chloride double salt.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Calcium pantothenate, calcium chloride double salt..., calcium chloride double salt. The food additive calcium chloride double salt of calcium pantothenate may... information required by the Act, the following: (1) The name of the additive “calcium chloride double salt...

  18. Thermogravimetric Thin Aqueous Film Corrosion Studies of Alloy 22; Calcium Chloride Solutions at 150C and Atmospheric Pressure

    SciTech Connect

    Hailey, P; Gdoowski, G

    2002-11-12

    The extent of reaction of alloy-22 with limited amounts of aqueous calcium chloride (CaCl{sub 2}) was investigated. Alloy-22 is a highly corrosion-resistant nickel-chromium-molybdenum-tungsten alloy. Specimens were polished to a mirror finish prior to aerosol salt deposition. An aqueous film was formed by deliquescence of deposited CaCl{sub 2} at 150 C and 22.5% relative humidity (RH). The reactant gas was a continuous flow of purified humidified laboratory air. The reaction progress as a function of time was continuously measured in-situ by a micro-balance. An initial weight gain due to deliquescence of the CaCl{sub 2} was observed. A steady weight loss was observed over the next 72 hours, after which no further weight change was observed. During this weight loss, white precipitates formed and the specimen's surface became visibly dry. The precipitate crystals were identified as Ca(OH){sub 2} by post-test Raman spectroscopy; however, energy dispersive X-ray spectroscopy indicated that there was a significant amount of chlorine contained in them.

  19. A Solution NMR Investigation into the Early Events of Amelogenin Nanosphere Self-Assembly Initiated with Sodium Chloride or Calcium Chloride

    SciTech Connect

    Buchko, Garry W.; Tarasevich, Barbara J.; Bekhazi, Jacky G.; Snead, Malcolm L.; Shaw, Wendy J.

    2008-12-08

    Using solution-state NMR spectroscopy, new insights into the early intermolecular interactions stabilizing amelogenin supramolecular assembly and the potential role of calcium ions have been discovered. Two-dimensional 1H-15N spectra were recorded for 15N-labeled amelogenin as a function of increasing Ca2+ concentration starting from monomeric conditions. Evidence for protein-protein interactions were observed between residues E18 and E40 in the N-terminus. At higher Ca2+ concentrations there was concurrent involvement of residues in both the N- (Y12-Q56) and the C-terminus (Q144-T171). Neither specific residues nor their stepwise interaction have previously been identified in the initial stages of nanosphere assembly.

  20. Development of an Inert Anode for Electrowinning in Calcium Chloride-Calcium Oxide Melts

    NASA Astrophysics Data System (ADS)

    Jiao, Shuqiang; Fray, Derek J.

    2010-02-01

    Studies were performed investigating the anodic testing of calcium ruthenate for electrowinning in calcium chloride-calcium oxide melts. The results showed that calcium ruthenate may be suitable as an inert anode in calcium chloride containing melts as it exhibited a low rate of corrosion in melts containing a small amount of calcium oxide, capable of producing oxygen on its surface, and did not contaminate the melt. To reduce the amount of ruthenium in the anode, solid solutions of calcium ruthenate in calcium titanate were investigated. At low concentrations, the solid solution is a semiconductor with a relatively low conductivity at room temperature, but at the temperature of operation, 1173 K, the material is an excellent electronic conductor. The other way of reducing the amount of ruthenium is to coat the solid solution onto a substrate. In this way, the substrate would give the mechanical strength while the coating would give the electrical conductivity and corrosion protection. Calcium ruthenate-based anodes can endure long-term use in the laboratory under an applied electrical field with oxygen being liberated on the anode indicating that these materials are candidates for the electrowining in calcium chloride-calcium oxide melts.

  1. Laboratory studies of the low-temperature deliquescence of calcium chloride salts: Relevance to aqueous solutions on Mars and in the Antarctic Dry Valleys

    NASA Astrophysics Data System (ADS)

    Gough, R. V.; Chevrier, V.; Tolbert, M. A.

    2013-12-01

    There is significant interest in the possible existence of liquid water on current Mars. This water would likely exist as a brine in order to be stable on Mars today. It has been proposed that soil salts could form aqueous solutions through either the melting of ice by low-eutectic salts, or by the deliquescence of hygroscopic salts present in the Martian soil. The focus thus far has largely been on perchlorate species, which can melt ice at temperatures as low as 206 K and can deliquesce at relative humidity values as low as 38% RH. A Mars-relevant salt that has been neglected thus far is calcium chloride (CaCl2). Calcium has been reported to be an abundant cation at the Phoenix landing site and Mars Science Laboratory instruments have recently identified calcium as well. Simulations suggest subsurface CaCl2 is an ideal candidate to produce brines with seasonality consistent with observed recurring slope lineae (RSL) (Chevrier et al., 2012). Finally, the only terrestrial site where RSL-like features have been observed (near Don Juan Pond in the Antarctic Dry Valleys) contains abundant CaCl2. These seasonal slope streaks are thought to form when CaCl2 in the soil deliquesces due to contact with atmospheric water vapor (Dickson et al., 2013). It is important to understand how this CaCl2 interacts with water vapor at low temperatures relevant to Mars and the Martian analog sites. Here we use a Raman microscope and environmental cell to monitor the low-temperature (223 - 273 K) deliquescence (solid to aqueous phase transition) and efflorescence (aqueous to solid phase transition) of three hydration states of CaCl2 (dihydrate, tetrahydrate, hexahydrate). We have found that the deliquescence relative humidity (DRH) increases with increasing hydration state, which is an expected result. Average DRH values over the temperature range studied are 20.0 × 2.6% RH for the dihydrate, 31.8 × 6.3% RH for the tetrahydrate and 60.7 × 1.6% RH for the hexahydrate. Once the aqueous

  2. Calcium-dependent chloride current in rat cerebellar Purkinje cell membranes.

    PubMed

    Vykhareva, E A; Zamoyski, V L; Grigoriev, V V; Bachurin, S O

    2015-01-01

    The presence of calcium-dependent potential-activated chloride currents in the membranes of freshly isolated rat cerebellar Purkinje cells (12-15 days) was shown by the whole-cell patch clamp technique. Chloride currents appeared in a sodium-free external solution and reversibly disappeared in the absence of external chloride and calcium ions.

  3. 21 CFR 172.330 - Calcium pantothenate, calcium chloride double salt.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Calcium pantothenate, calcium chloride double salt... Dietary and Nutritional Additives § 172.330 Calcium pantothenate, calcium chloride double salt. The food additive calcium chloride double salt of calcium pantothenate may be safely used in foods for...

  4. Repassivation Potential of Alloy 22 in Sodium and Calcium Chloride Brines

    SciTech Connect

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

    2007-08-11

    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.

  5. Calcium chloride rhenate(VII) dihydrate.

    PubMed

    Jarek, Urszula; Hołyńska, Małgorzata; Rlepokura, Katarzyna; Lis, Tadeusz

    2007-09-01

    The crystal structure of calcium chloride rhenate(VII) dihydrate, CaCl(ReO4).2H2O, investigated at 85 K, consists of calcium cations, chloride anions, rhenate(VII) anions and water molecules. In the nearly tetrahedral rhenate(VII) anion, all constituent atoms lie on special positions of m2m (Re) and m (O) site symmetries. The Cl- anion and water O atom lie on special positions of m2m and 2 site symmetries, respectively. The Ca2+ ion, also on a special position (m2m), is eight-coordinated in a distorted square-antiprismatic coordination mode. The crystal has a layered structure stabilized by Ca-O coordination bonds and O-H...Cl hydrogen bonds.

  6. A high-salinity solution with calcium chloride enables RNase-free, easy plasmid isolation within 55 minutes.

    PubMed

    Sasagawa, Noboru; Koebis, Michinori; Yonemura, Yoji; Mitsuhashi, Hiroaki; Ishiura, Shoichi

    2013-12-01

    We dramatically improved a plasmid-isolation protocol based on the popular alkaline-sodium dodecyl sulfate plasmid isolation method. Our modified method provides significant time and cost savings. We used a modified solution during the neutralization step, which allowed us to skip several subsequent handling steps, saving a great amount of time. The plasmids purified by this method were of high quality, and the optical density ratio 260 and 280 was approximately 1.8. Plasmid DNA isolated by our method was of sufficient quality to perform subsequent restriction enzyme cuts and other downstream experiments, including budding yeast transformation, cultured cell transfection, and Caenorhabditis elegans injection experiments.

  7. REMOVAL OF CHLORIDE FROM AQUEOUS SOLUTIONS

    DOEpatents

    Schulz, W.W.

    1959-08-01

    The removal of chlorides from aqueons solutions is described. The process involves contacting the aqueous chloride containing solution with a benzene solution about 0.005 M in phenyl mercuric acetate whereby the chloride anions are taken up by the organic phase and separating the organic phase from the aqueous solutions.

  8. Organoaqueous calcium chloride electrolytes for capacitive charge storage in carbon nanotubes at sub-zero-temperatures.

    PubMed

    Gao, Yun; Qin, Zhanbin; Guan, Li; Wang, Xiaomian; Chen, George Z

    2015-07-11

    Solutions of calcium chloride in mixed water and formamide are excellent electrolytes for capacitive charge storage in partially oxidised carbon nanotubes at unprecedented sub-zero-temperatures (e.g. 67% capacitance retention at -60 °C).

  9. Uptake of chloride and carbonate ions by calcium monosulfoaluminate hydrate

    SciTech Connect

    Mesbah, Adel; Cau-dit-Coumes, Celine; Frizon, Fabien

    2012-08-15

    Decommissioning of old nuclear reactors may produce waste streams containing chlorides and carbonates, including radioactive {sup 36}Cl{sup -} and {sup 14}CO{sub 3}{sup 2-}. Their insolubilization by calcium monosulfoaluminate hydrate was investigated. Carbonates were readily depleted from the solution, giving at thermodynamic equilibrium monocarboaluminate, monocarboaluminate + calcite, or calcite only, depending on the initial ratio between the anion and calcium monosulfoaluminate hydrate. Chloride ions reacted more slowly and were precipitated as Kuzel's salt, Kuzel's and Friedel's salts, or Friedel's salt only. Rietveld refinement of X-Ray powder diffraction patterns was successfully used to quantify the phase distributions, which were compared to thermodynamic calculations. Moreover, analysing the lattice parameters of Kuzel's salt as a function of its chloride content showed the occurrence of a restricted solid solution towards the sulfate side with general formula 3CaO{center_dot}Al{sub 2}O{sub 3}{center_dot}xCaCl{sub 2}{center_dot}(1 - x)CaSO{sub 4}{center_dot}(12 - 2x){center_dot}H{sub 2}O (0.36 {<=} x {<=} 0.50).

  10. Radiotracer studies on calcium ion-selective electrode membranes based on poly(vinyl chloride) matrices.

    PubMed

    Craggs, A; Moody, G J; Thomas, J D; Willcox, A

    Radiotracer studies with (45)Ca and (36)Cl demonstrate that PVC matrix membranes containing Orion 92-20-02 liquid calcium ion-exchanger are permselective to counter-cations. Diffusion coefficients are quoted for the migration of (45)Ca between pairs of calcium solutions and are discussed in terms of solution concentration, membrane thickness and concentration level of sensor in the membrane. Migration of calcium ions from calcium chloride solution to a Group (II) metal chloride solution through a PVC membrane containing calcium liquid ion-exchanger is discussed in terms of solvent extraction and electrode selectivity coefficient parameters. Thus, magnesium, strontium and barium ions appear to inhibit migration through the membrane by their low affinity for the membrane liquid ion-exchanger sites, while the inhibition by beryllium ions is attributed to site blockage by the strong affinity of dialkylphosphate sites for beryllium.

  11. Chorda tympani nerve modulates the rat's avoidance of calcium chloride.

    PubMed

    Golden, Glen J; Voznesenskaya, Anna; Tordoff, Michael G

    2012-03-20

    Calcium intake depends on orosensory factors, implying the presence of a mechanism for calcium detection in the mouth. To better understand how information about oral calcium is conveyed to the brain, we examined the effects of chorda tympani nerve transection on calcium chloride (CaCl(2)) taste preferences and thresholds in male Wistar rats. The rats were given bilateral transections of the chorda tympani nerve (CTX) or control surgery. After recovery, they received 48-h two-bottle tests with an ascending concentration series of CaCl(2). Whereas control rats avoided CaCl(2) at concentrations of 0.1mM and higher, rats with CTX were indifferent to CaCl(2) concentrations up to 10mM. Rats with CTX had significantly higher preference scores for 0.316 and 3.16 mM CaCl(2) than did control rats. The results imply that the chorda tympani nerve is required for the normal avoidance of CaCl(2) solution.

  12. The influence of sulphates on chloride binding and pore solution chemistry

    SciTech Connect

    Xu, Y.

    1997-12-01

    Ordinary Portland cement (OPC) and OPC/ground granulated blast furnace slag (GGBS) 65% cements containing 2.0 to 9.0% sulphates derived from sodium sulphate and calcium sulphate were investigated in respect to their chloride binding properties and the concentrations of chloride and hydroxyl ions in the pore solutions. Chlorides derived from sodium and calcium chlorides were introduced at the time of mixing. The results indicate that calcium sulphate has a different effect on chloride binding and the pore solution chemistry than sodium sulphate. The slag cement has higher chloride binding capacities as a result of simple replacement for OPC, but at the same sulphate contents, the slag cement does not give the expected higher binding capacities, suggesting that the difference in sulphate content between the two cements may be the main reason for their different chloride binding behavior.

  13. Crystallization of calcium sulfate dihydrate and calcium sulfite hemihydrate from synthetic flue gas desulfurization solutions: Final report

    SciTech Connect

    Trofe, T.W.; Fishman, V.A.; Meserole, F.B.

    1986-10-01

    The precipitation of calcium sulfate dihydrate (CaSO/sub 4/.2H/sub 2/O) and calcium sulfite hemihydrate (CaSO/sub 3/.1/2H/sub 2/O) from high, up to 240,000 mg/L, total dissolved solids (TDS) solutions was studied at 50/sup 0/C. The solutions were selected to cover a range of solution compositions of magnesium, calcium, sodium, chloride, and sulfate. Precipitation rates along with crystal habit and size changes were measured to determine the effects of these dissolved species as compared to dilute solution conditions. Calcium sulfate dihydrate (gypsum) precipitation rate was accelerated in the high TDS solutions, especially those containing chloride ion. Alternatively, calcium sulfite hemihydrate precipitation rate was found to be faster in high sulfate ion containing solutions. Sodium ion appears to produce gypsum crystals more columnar in habit while solutions containing high amounts of calcium produced very lamellar gypsum crystals. Solutions containing magnesium produced acicular gypsum crystals. Calcium sulfite hemihydrate solids precipitated from solutions containing high sulfate concentrations were rod shaped and globular as compared to the lamellar calcium sulfite hemihydrate crystals precipitated from high chloride and dilute solution liquors. Calcium sulfate-calcium sulfite solid solutions were characterized using infrared spectroscopy. Ion scavenging of Na, Mg, and Cl by gypsum and calcium sulfite solids precipitated from these high TDS solutions was also investigated. 10 refs., 21 figs., 13 tabs.

  14. [Determination of Chloride Salt Solution by NIR Spectroscopy].

    PubMed

    Zhang, Bin; Chen, Jian-hong; Jiao, Ming-xing

    2015-07-01

    Determination of chloride salt solution by near infrared spectrum plays a very important role in Biomedicine. The near infrared spectrum analysis of Sodium chloride, potassium chloride, calcium chloride aqueous solution shows that the concentration change of chloride salt can affect hydrogen bond, resulting in the variation of near infrared spectrum of water. The temperature influence on NIR spectrum has been decreased by choosing reasonable wavelength range and the wavelength where the temperature effects are zero (isosbestic point). Chlorine salt prediction model was established based on partial least squares method and used for predicting the concentration of the chlorine ion. The impact on near infrared spectrum of the cation ionic radius, the number of ionic charge, the complex effect of ionic in water has also discussed in this article and the reason of every factor are analysed. Experimental results show that the temperature and concentration will affect the near-infrared spectrum of the solution, It is found that the effect of temperature plays the dominant role at low concentrations of chlorine salt; rather, the ionic dominates at high concentration. Chloride complexes are formed in aqueous solution, It has an effect on hydrogen bond of water combining with the cations in chlorine salt solution, Comparing different chloride solutions at the same concentration, the destruction effects of chloride complexes and catnions on the hydrogen bond of water increases in the sequences: CaCl2 >NaCl>KC. The modeling result shows that the determination coefficients (R2) = 99.97%, the root mean square error of cross validation (RM- SECV) = 4.51, and the residual prediction deviation (RPD) = 62.7, it meets the daily requirements of biochemical detection accuracy.

  15. Fermentation of cucumbers brined with calcium chloride instead of sodium chloride

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Generation of waste water containing sodium chloride from cucumber fermentation tank yards could be eliminated if cucumbers were fermented in brines that did not contain this salt. To determine if this is feasible, cucumbers were fermented in brines that contained only calcium chloride to maintain f...

  16. Commercial scale cucumber fermentations brined with calcium chloride instead of sodium chloride

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Development of low salt cucumber fermentation processes present opportunities to reduce the amount of sodium chloride (NaCl) that reaches fresh water streams from industrial activities. The objective of this research was to translate cucumber fermentation brined with calcium chloride instead of NaCl...

  17. Skin and soft tissue necrosis from calcium chloride in a deicer.

    PubMed

    Kim, Min P; Raho, Vittorio J; Mak, John; Kaynar, A Murat

    2007-01-01

    Calcium chloride salt is the principle ingredient of many commercially available deicers. Calcium chloride melts snow and ice by its osmotic action. We present a case of skin and soft tissue necrosis associated with the use of a calcium chloride-containing deicer. Although calcium chloride is known to produce soft tissue necrosis if it extravasates during intravenous administration, necrosis and skin sloughing has rarely been described after topical exposure to this salt. Calcium chloride likely produces tissue injury from the heat liberated by mixing calcium chloride with water (exothermic reaction) and from direct calcium deposits in the skin (calcinosis cutis) and soft tissue.

  18. Glucose stimulates calcium-activated chloride secretion in small intestinal cells.

    PubMed

    Yin, Liangjie; Vijaygopal, Pooja; MacGregor, Gordon G; Menon, Rejeesh; Ranganathan, Perungavur; Prabhakaran, Sreekala; Zhang, Lurong; Zhang, Mei; Binder, Henry J; Okunieff, Paul; Vidyasagar, Sadasivan

    2014-04-01

    The sodium-coupled glucose transporter-1 (SGLT1)-based oral rehydration solution (ORS) used in the management of acute diarrhea does not substantially reduce stool output, despite the fact that glucose stimulates the absorption of sodium and water. To explain this phenomenon, we investigated the possibility that glucose might also stimulate anion secretion. Transepithelial electrical measurements and isotope flux measurements in Ussing chambers were used to study the effect of glucose on active chloride and fluid secretion in mouse small intestinal cells and human Caco-2 cells. Confocal fluorescence laser microscopy and immunohistochemistry measured intracellular changes in calcium, sodium-glucose linked transporter, and calcium-activated chloride channel (anoctamin 1) expression. In addition to enhancing active sodium absorption, glucose increased intracellular calcium and stimulated electrogenic chloride secretion. Calcium imaging studies showed increased intracellular calcium when intestinal cells were exposed to glucose. Niflumic acid, but not glibenclamide, inhibited glucose-stimulated chloride secretion in mouse small intestines and in Caco-2 cells. Glucose-stimulated chloride secretion was not seen in ileal tissues incubated with the intracellular calcium chelater BAPTA-AM and the sodium-potassium-2 chloride cotransporter 1 (NKCC1) blocker bumetanide. These observations establish that glucose not only stimulates active Na absorption, a well-established phenomenon, but also induces a Ca-activated chloride secretion. This may explain the failure of glucose-based ORS to markedly reduce stool output in acute diarrhea. These results have immediate potential to improve the treatment outcomes for acute and/or chronic diarrheal diseases by replacing glucose with compounds that do not stimulate chloride secretion.

  19. Chloride Analysis of RFSA Second Campaign Dissolver Solution

    SciTech Connect

    Holcomb, H.P.

    2001-05-17

    The dissolver solution from the second RFSA campaign was analyzed for chloride using the recently-developed turbidimetric method. Prior to chloride removal in head end, the solution contained 1625 ppm chloride. After chloride removal with Hg(I) and prior to feeding to solvent extraction, the solution contained only 75 ppm chloride. This report discusses those analysis results.

  20. Accurate description of calcium solvation in concentrated aqueous solutions.

    PubMed

    Kohagen, Miriam; Mason, Philip E; Jungwirth, Pavel

    2014-07-17

    Calcium is one of the biologically most important ions; however, its accurate description by classical molecular dynamics simulations is complicated by strong electrostatic and polarization interactions with surroundings due to its divalent nature. Here, we explore the recently suggested approach for effectively accounting for polarization effects via ionic charge rescaling and develop a new and accurate parametrization of the calcium dication. Comparison to neutron scattering and viscosity measurements demonstrates that our model allows for an accurate description of concentrated aqueous calcium chloride solutions. The present model should find broad use in efficient and accurate modeling of calcium in aqueous environments, such as those encountered in biological and technological applications.

  1. Process for drying calcium chloride generated in high chloride flue gas desulfurization systems

    SciTech Connect

    Gleason, R.J.; Sui, C.T.

    1982-03-30

    Some flue gas desulfurization processes applied to fuels containing high chloride concentrations are utilizing, or plan to utilize, by-product gypsum from the process stream. The utilization of such a process results in a calcium chloride buildup in the flue gas desulfurization system from fuels or water resource containing significant chlorides which interferes with the absorption and utilization of the lime or limestone reagent. In this invention, a method is used to convert the calcium chloride to a dry material by utilizing flue gas at elevated temperatures, normally found before an air preheater on steam generators used to produce power or any other conventional large size steam boilers. The monohydrate is produced at temperatures above 3500 F. By applying this drying process with a power plant system, energy consumed for this drying operation is very efficient.

  2. Retail consumer acceptance of beef tenderized with calcium chloride.

    PubMed

    Miller, M F; Huffman, K L; Gilbert, S Y; Hamman, L L; Ramsey, C B

    1995-08-01

    Beef inside round subprimals were injected with a 200 mM calcium chloride (CaCl2) solution at 5% (wt/wt) to determine its effects on beef steak palatability and quality traits. Alternating subprimals from the right and left sides were selected for injection of CaCl2 or not injected to serve as a control. After 7 d of postmortem storage, 2.5-cm-thick steaks were cut from each subprimal for consumer evaluation (n = 478) in a retail setting. Three supermarkets with customers varying widely in income were selected as test sites for measuring consumer perceptions of the treated and control steaks and package labeling acceptance. Supermarket, income level, education, and sex were evaluated for their impact on acceptance of calcium-injected beef. Steak flavor and tenderness both were important in determining beef eating quality; 50% of consumers said tenderness was the most important and 40% said flavor was the most important. Consumers visually preferred CaCl2-treated steaks 71% of the time over the control steaks based on package labeling. The CaCl2 injection improved tenderness, juiciness, flavor desirability, and overall palatability ratings by the consumers for inside round steaks and did not cause any off-flavor problems compared with the controls. Therefore, injecting beef with a solution of 200 mM CaCl2 at 5% (wt/wt) can improve retail consumer evaluations of beef steak tenderness and reduce tenderness variation without detrimental effects on other palatability or quality traits. PMID:8567467

  3. Characteristics of two calcium pectinates prepared from citrus pectin using either calcium chloride or calcium hydroxide.

    PubMed

    Guo, Xiujun; Duan, Hanying; Wang, Chao; Huang, Xuesong

    2014-07-01

    Calcium pectinate (CaP) was prepared from citrus pectin using either calcium chloride (C-CaP) or calcium hydroxide (HO-CaP) as the source of calcium for the reaction. The production yields and the rates of decalcification for the two calcium pectinates were compared and both found to be lower for C-CaP than for HO-CaP. In an attempt to explain these differences, certain chemical and structural characteristics of the two products, including functional groups (-CH3, C═O, COO-), rheological properties, morphology, and egg-box junction zones, were investigated by Fourier transformation infrared (FTIR) spectroscopy, rheology, scanning electron microscopy (SEM), and X-ray diffraction (XRD). The results from FTIR showed that, with an increase in calcium content, the wavenumber values and peak areas of FTIR for -CH3, C═O, and COO- groups all changed dramatically for C-CaP, while they were virtually unchanged for HO-CaP. Rheological analysis of the CaP gel showed that C-CaP had a stronger cross-linked network structure and a greater range of elastic behavior as compared to HO-CaP. SEM images of two CaP gels showed irregular membranes. C-CaP maintained a tight structure and a smooth surface, whereas HO-CaP was loose and rough. The results from XRD revealed a higher degree of crystallinity within C-CaP than within HO-CaP, which indicated that C-CaP possessed compact, ordered, and stable egg-box junction zones while the junction zones in HO-CaP were metastable and loose.

  4. 40 CFR 415.40 - Applicability; description of the calcium chloride production subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... calcium chloride production subcategory. 415.40 Section 415.40 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Calcium Chloride Production Subcategory § 415.40 Applicability; description of the calcium chloride production subcategory. The provisions of this subpart are applicable to...

  5. 40 CFR 415.40 - Applicability; description of the calcium chloride production subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... calcium chloride production subcategory. 415.40 Section 415.40 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Calcium Chloride Production Subcategory § 415.40 Applicability; description of the calcium chloride production subcategory. The provisions of this subpart are applicable to...

  6. 40 CFR 415.40 - Applicability; description of the calcium chloride production subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... calcium chloride production subcategory. 415.40 Section 415.40 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Calcium Chloride Production Subcategory § 415.40 Applicability; description of the calcium chloride production subcategory. The provisions of this subpart are applicable to...

  7. 40 CFR 415.40 - Applicability; description of the calcium chloride production subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... calcium chloride production subcategory. 415.40 Section 415.40 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Calcium Chloride Production Subcategory § 415.40 Applicability; description of the calcium chloride production subcategory. The provisions of this subpart are applicable to...

  8. 40 CFR 415.40 - Applicability; description of the calcium chloride production subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... calcium chloride production subcategory. 415.40 Section 415.40 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Calcium Chloride Production Subcategory § 415.40 Applicability; description of the calcium chloride production subcategory. The provisions of this subpart are applicable to...

  9. Calcium phosphate stabilization of fly ash with chloride extraction.

    PubMed

    Nzihou, Ange; Sharrock, Patrick

    2002-01-01

    Municipal solid waste incinerator by products include fly ash and air pollution control residues. In order to transform these incinerator wastes into reusable mineral species, soluble alkali chlorides must be separated and toxic trace elements must be stabilized in insoluble form. We show that alkali chlorides can be extracted efficiently in an aqueous extraction step combining a calcium phosphate gel precipitation. In such a process, sodium and potassium chlorides are obtained free from calcium salts, and the trace metal ions are immobilized in the calcium phosphate matrix. Moderate calcination of the chemically treated fly ash leads to the formation of cristalline hydroxylapatite. Fly ash spiked with copper ions and treated by this process shows improved stability of metal ions. Leaching tests with water or EDTA reveal a significant drop in metal ion dissolution. Hydroxylapatite may trap toxic metals and also prevent their evaporation during thermal treatments. Incinerator fly ash together with air pollution control residues, treated by the combined chloride extraction and hydroxylapatite formation process may be considered safe to use as a mineral filler in value added products such as road base or cement blocks.

  10. Inhibition of nitrite-induced toxicity in channel catfish by calcium chloride and sodium chloride

    USGS Publications Warehouse

    Tommasso J.R., Wright; Simco, B.A.; Davis, K.B.

    1980-01-01

    Environmental chloride has been shown to inhibit methemoglobin formation in fish, thereby offering a protective effect against nitrite toxicity. Channel catfish (Ictalurus punctatus) were simultaneously exposed to various environmental nitrite and chloride levels (as either CaCl2 or NaCl) in dechlorinated tap water (40 mg/L total hardness, 47 mg/L alkalinity, 4 mg/L chloride, pH = 6.9-7.1, and temperature 21-24°C). Methemoglobin levels in fish simultaneously exposed to 2.5 mg/L nitrite and up to 30 mg/L chloride as either CaCl2 or NaCl were similar but significantly lower than in unprotected fish. Exposure to 10 mg/L nitrite and 60 mg/L chloride resulted in methemoglobin levels similar to those of the controls; most unprotected fish died. Fish exposed to 10 mg/L nitrite had significantly lower methemoglobin levels when protected with 15.0 mg/L chloride as CaCl2 than with NaCl. Fish exposed to nitrite in the presence of 60 mg/L chloride (as either CaCl2 or NaCl) had similar 24-h LC50 values that were significantly elevated above those obtained in the absence of chloride. Calcium had little effect on tolerance to nitrite toxicity in channel catfish in contrast to its large effect reported in steelhead trout (Salmo gairdneri).

  11. Heat stability of milk supplemented with calcium chloride.

    PubMed

    On-Nom, N; Grandison, A S; Lewis, M J

    2012-04-01

    Calcium chloride (0-25 mM) was added to skim milk powder that was reconstituted to 9% total solids. Heat stability was evaluated between 60 and 120°C for different times by observing whether samples had coagulated, and by measuring the amount of sediment and residual protein in the centrifuged supernatant. Milk samples were also dialyzed during their respective heat treatments to recover the soluble phase at different temperatures to measure pH and ionic calcium. The transition conditions between good and poor heat stability were established for different calcium chloride concentrations and temperatures. As temperature increased, coagulation occurred at lower levels of added calcium chloride. The transition was quite distinct at higher temperatures but less so at lower temperatures; it was initiated by an increase in sediment formation before a firm coagulum was formed. Both pH and ionic calcium decreased in dialysates as temperature increased. No coagulation was observed if Ca(2+) was <0.5 mM and pH was >6.3 in dialysates taken at their respective coagulation temperatures. Being able to measure pH and ionic calcium at high temperatures will allow better understanding of factors affecting heat stability. Electrophoresis of the supernatants permitted identification of the protein fractions participating in the coagulation process. When coagulation was observed below 80°C, substantial amounts of undenatured β-lactoglobulin and α-lactalbumin were found in the supernatant, as well as some soluble casein fractions. All the major whey protein and casein fractions were found in the sediment.

  12. Effects of calcium chloride in coal structure, reactivity, emissions, and corrosion

    SciTech Connect

    Pan, W.P.

    1985-01-01

    This study was designed to determine the effects of CaCl/sub 2/ solution on lignite coal structure, reactivity, and emissions and on related boiler corrosion. CaCl/sub 2/ is attractive because of its antifreeze and antithawing properties during coal transportation and its catalytic effect during coal combustion. Addition of 1.4 wt% CaCl/sub 2/ did not substantially alter the coal structure, based on XRD, IR, density, porosity and light microscopy studies. The only significant difference between untreated char and treated char was that the treated char showed a more disordered structure. From reactivity studies, the addition of CaCl/sub 2/ retarded the decomposition of coal in the early stage, due to the effect of chloride; then promoted the decomposition of coal, due to the effect of calcium. From emissions studies, calcium chloride reduced sulfur emission which was retained principally as CaSO/sub 4/, and also increased the chloride ion level. From corrosion studies, calcium chloride reduced sulfur corrosion by lowering the level of sulfur oxides in the gas, but in the presence of higher levels of chlorides, increased the extent of pitting corrosion problems.

  13. Effects of calcium hydroxide and calcium chloride addition to bentonite in iron ore pelletization.

    PubMed

    Tugrul, Nurcan; Derun, Emek Moroydor; Pişkin, Mehmet

    2006-10-01

    Pyrite ash is created as waste from the roasting of pyrite ores during the production of sulphuric acid. These processes generate great amounts of pyrite ash waste that is generally land filled. This creates serious environmental pollution due to the release of acids and toxic substances. Pyrite ash waste can be utilized in the iron production industry as a blast furnace feed to process this waste and prevent environmental pollution. The essential parameters affecting the pelletization process of pyrite ash were studied using bentonite as a binder. Experiments were then carried out using bentonite and a mixture of bentonite with calcium hydroxide and calcium chloride in order to make the bentonite more effective. The metallurgical properties of pyrite ash, bentonite, calcium hydroxide, calcium chloride, a mixture of these and sintered pellets were studied using X-ray analysis. The crushing strength tests were carried out to investigate the strength of pyrite ash waste pellets. The results of these analyses showed that pyrite ash can be agglomerated to pellets and used in the iron production industry as a blast furnace feed. The crushing strength of the pellets containing calcium hydroxide and calcium chloride in addition to bentonite was better than the strength of pellets prepared using only bentonite binder. PMID:17121116

  14. Hydrolysis of ferric chloride in solution

    SciTech Connect

    Lussiez, G.; Beckstead, L.

    1996-11-01

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

  15. REMOVAL OF CHLORIDE FROM AQUEOUS SOLUTIONS

    DOEpatents

    Hyman, M.L.; Savolainen, J.E.

    1960-01-01

    A method is given for dissolving reactor fuel elements in which the uranium is associated with a relatively inert chromium-containing alloy such as stainless steel. An aqueous mixture of acids comprising 2 to 2.5 molar hydrochloric acid and 4 to 8 molar nitric acid is employed in dissolving the fuel element. In order io reduce corrosion in subsequent processing of the resulting solution, chloride values are removed from the solution by contacting it with concentrated nitric acid at an elevated temperature.

  16. Effect of chlorides on solution corrosivity of methyldiethanolamine (MDEA) solutions

    SciTech Connect

    Rooney, P.C.; Bacon, T.R.; DuPart, M.S.; Willbanks, K.D.

    1997-08-01

    Solution corrosivity of MDEA/water solutions containing added HCl or NaCl have been measured by weight loss coupons at 250 F and by linear polarization resistance (LPR) at 208 F using carbon steel, 304SS, 316SS and 410SS. General corrosion as well as pitting or crevice corrosion tendencies were recorded for each species. Based on these results, recommendations are made for chlorides in MDEA that minimizes corrosion in gas treating operations.

  17. THE INFLUENCE OF CALCIUM CHLORIDE UPON EXPERIMENTAL BOTULISM.

    PubMed

    Hall, I C; Davis, N C

    1923-03-31

    1. Calcium chloride given subcutaneously, intraperitoneally, or intravenously has been found to have no effect upon the production of botulism following the injection of Bacillus botulinus (Strain 80B) into the peritoneal cavity of guinea pigs. 2. Treatment of Bacillus botulinus with alcohol has been found markedly to decrease its toxicity for guinea pigs. This is in conformity with the work of Bronfenbrenner and Schlesinger. 3. Toxin-free spores of Bacillus botulinus have been found pathogenic for guinea pigs. 4. No prejudice as to possible results in rabbits should be based upon the above conclusions.

  18. Safety of compounded calcium chloride admixtures for peripheral intravenous administration in the setting of a calcium gluconate shortage.

    PubMed

    Anger, Kevin E; Belisle, Caryn; Colwell, Megan B; Dannemiller, Robert; Alawadhi, Burhan; Wilkocki, Alex; Szumita, Paul M

    2014-10-01

    Calcium gluconate is preferred over calcium chloride for intravenous (IV) repletion of calcium deficiencies in the inpatient setting. In the setting of a national shortage of IV calcium gluconate, our institution implemented a compounded calcium chloride admixture for IV administration. The objective of this analysis is to evaluate the peripheral infusion site safety of compounded IV calcium chloride admixtures in adult inpatients. A total of 222 patients, encompassing 224 inpatient admissions, from April to June 2011 were retrospectively reviewed. Sterile preparations of calcium chloride in 5% dextrose (600 mg/250 mL and 300 mg/100 mL) were used during the study time period. Adverse infusion site reactions were assessed using an institutional infiltration and phlebitis grading system. A total of 333 doses were administered peripherally. In all, 4 (1.8%) patients experienced a moderate to severe infusion site reaction, with 3 due to phlebitis and 1 due to infiltration. Naranjo Nomogram for Adverse Drug Reaction Assessment classified all 4 reactions to have a possible link to calcium chloride administration. Peripheral administration of compounded calcium chloride admixtures in 5% dextrose is associated with a low incidence of IV infusion site reactions and can be considered as an alternative in the event of a calcium gluconate shortage.

  19. Effect of chlorides on reinforcing steel exposed to simulated concrete solutions

    SciTech Connect

    Kitowski, C.J.; Wheat, H.G.

    1997-03-01

    The behavior of steel in chloride-free and chloride-contaminated simulated concrete solutions was studied to observe the degradation of steel as a result of addition of chlorides. One of the simulated concrete solutions was a saturated calcium hydroxide (Ca[OH]{sub 2}) solution while the other was a solution made up of 0.6 M potassium hydroxide (KOH) + 0.2 M sodium hydroxide (NaOH) + 0.001 M Ca(OH){sub 2}. Corrosion behavior of the steel was studied electrochemically, and changes in the steel surfaces were studied using scanning electron microscopy (SEM) and Auger electron spectroscopy (AES). Behavior was compared to that of reinforced concrete cylinders subjected to alternating wetting and drying in 3.5% sodium chloride (NaCl) solutions.

  20. Liquid Calcium Chloride Solar Storage: Concept and Analysis

    SciTech Connect

    Quinnell, J. A.; Davidson, J. H.; Burch, J.

    2010-01-01

    Aqueous calcium chloride has a number of potential advantages as a compact and long-term solar storage medium compared to sensibly heated water. The combination of sensible and chemical binding energy of the liquid desiccant provides higher energy densities and lower thermal losses, as well as a temperature lift during discharge via an absorption heat pump. Calcium chloride is an excellent choice among desiccant materials because it is relatively inexpensive, non-toxic, and environmentally safe. This paper provides an overview of its application for solar storage and presents a novel concept for storing the liquid desiccant in a single storage vessel. The storage system uses an internal heat exchanger to add and discharge thermal energy and to help manage the mass, momentum, and energy transfer in the tank. The feasibility of the proposed concept is demonstrated via a computational fluid dynamic study of heat and mass transfer in the system over a range of Rayleigh, Lewis, Prandtl, and buoyancy ratio numbers expected in practice.

  1. A non-chromate treatment for calcium chloride brines

    SciTech Connect

    Sotoudeh, K.; Funderburg, I.M.

    1994-12-31

    In refrigeration terminology, a brine is any liquid-cooled refrigerant which is circulated as a heat-transfer fluid. Low toxicity and low cost have helped the popularity of calcium chloride brines. The corrosive nature of this brine has traditionally been managed by using chromates. However, the ever increasing environmental restrictions on the use of chromates, have encouraged the development of non-chromate alternatives. This paper details development of a novel calcium chloride corrosion inhibitor formulation free of chromate and other heavy metals. It also discusses some intermediate formulations which ultimately led to the final formulation. Within the temperature range of {minus}35 C ({minus}30 F) to 820 C (180 F), the inhibitor program is compatible with 0 to 35 wt% (specific gravity 1.00 to 1.35) brine. Its flexible operating pH (6.4--11) eliminates the need for frequent caustic addition. This inhibitor is designed to protect mild steel, copper and, eliminate fouling within the above operating parameters.

  2. Noradrenaline activates a calcium-activated chloride conductance and increases the voltage-dependent calcium current in cultured single cells of rat portal vein.

    PubMed

    Pacaud, P; Loirand, G; Mironneau, C; Mironneau, J

    1989-05-01

    1. Membrane responses were recorded by a patch pipette technique in cultured cells isolated from rat portal vein. Using the whole-cell mode, pressure ejections of noradrenaline evoked depolarization (current clamp) and inward current (voltage clamp) at membrane potentials of -60 to -70 mV. The noradrenaline-induced response was reversibly blocked by prazosin indicating that the response was mediated by alpha 1-adrenoceptors. 2. The ionic mechanism of the noradrenaline-induced inward current was investigated in potassium-free caesium-containing solutions. Alteration of the chloride equilibrium potential produced similar changes in the reversal potential of the noradrenaline-induced current, indicating that noradrenaline opened chloride-selective channels. There was no evidence implicating sodium or calcium as the charge-carrying ion. 3. Caffeine applied in the bathing solution also induced a transient increase in chloride conductance but the noradrenaline-induced response was lost after application of caffeine. This is interpreted to mean that the increase in chloride conductance induced by noradrenaline and caffeine can occur as a consequence of a rise in intracellular calcium concentration depending on release of calcium from the same intracellular stores. 4. In the presence of caffeine, noradrenaline increased both the voltage-dependent calcium and chloride membrane conductances during application of repetitive depolarizing pulses. It is concluded that in isolated cells of the rat portal vein the depolarization in response to noradrenaline is mediated by an increase in chloride conductance depending on both the calcium release from intracellular stores and the increase of the voltage-dependent calcium current. PMID:2470458

  3. A comprehensive search for calcium binding sites critical for TMEM16A calcium-activated chloride channel activity.

    PubMed

    Tien, Jason; Peters, Christian J; Wong, Xiu Ming; Cheng, Tong; Jan, Yuh Nung; Jan, Lily Yeh; Yang, Huanghe

    2014-06-30

    TMEM16A forms calcium-activated chloride channels (CaCCs) that regulate physiological processes such as the secretions of airway epithelia and exocrine glands, the contraction of smooth muscles, and the excitability of neurons. Notwithstanding intense interest in the mechanism behind TMEM16A-CaCC calcium-dependent gating, comprehensive surveys to identify and characterize potential calcium sensors of this channel are still lacking. By aligning distantly related calcium-activated ion channels in the TMEM16 family and conducting systematic mutagenesis of all conserved acidic residues thought to be exposed to the cytoplasm, we identify four acidic amino acids as putative calcium-binding residues. Alterations of the charge, polarity, and size of amino acid side chains at these sites alter the ability of different divalent cations to activate the channel. Furthermore, TMEM16A mutant channels containing double cysteine substitutions at these residues are sensitive to the redox potential of the internal solution, providing evidence for their physical proximity and solvent accessibility.

  4. Purification of aqueous plutonium chloride solutions via precipitation and washing.

    SciTech Connect

    Stroud, M. A.; Salazar, R. R.; Abney, Kent David; Bluhm, E. A.; Danis, J. A.

    2003-01-01

    Pyrochemical operations at Los Alamos Plutonium Facility (TA-55) use high temperature melt s of calcium chloride for the reduction of plutonium oxide to plutonium metal and hi gh temperature combined melts of sodium chloride and potassium chloride mixtures for the electrorefining purification of plutonium metal . The remaining plutonium and americium are recovered from thes e salts by dissolution in concentrated hydrochloric acid followed by either solvent extraction or io n exchange for isolation and ultimately converted to oxide after precipitation with oxalic acid . Figur e 1 illustrates the current aqueous chloride flow sheet used for plutonium processing at TA-55 .

  5. 46 CFR 151.50-75 - Ferric chloride solution.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Ferric chloride solution. 151.50-75 Section 151.50-75... CARRYING BULK LIQUID HAZARDOUS MATERIAL CARGOES Special Requirements § 151.50-75 Ferric chloride solution... solution must be lined with rubber, corrosion resistant plastic, or a material approved by the...

  6. 46 CFR 151.50-75 - Ferric chloride solution.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Ferric chloride solution. 151.50-75 Section 151.50-75... CARRYING BULK LIQUID HAZARDOUS MATERIAL CARGOES Special Requirements § 151.50-75 Ferric chloride solution... solution must be lined with rubber, corrosion resistant plastic, or a material approved by the...

  7. Antimicrobial Effect of Calcium Chloride Alone and Combined with Lactic Acid Injected into Chicken Breast Meat.

    PubMed

    Alahakoon, Amali U; Jayasena, Dinesh D; Jung, Samooel; Kim, Hyun Joo; Kim, Sun Hyo; Jo, Cheorun

    2014-01-01

    Chicken breast meat was injected with calcium chloride alone and in combination with lactic acid (0.01% and 0.002%, respectively). The inhibitory effects of the treatments on microbial growth were determined in the injected chicken breast meat stored at 4°C under aerobic packaging condition for 0, 3, and 7 d. Calcium chloride combined with 0.002% and 0.01% lactic acid reduced microbial counts by 0.14 and 1.08 Log CFU/g, respectively, however, calcium chloride alone was unable to inhibit microbial growth. Calcium chloride combined with 0.01% lactic acid was the most effective antimicrobial treatment and resulted in the highest initial redness value. Calcium chloride alone and combined with lactic acid suppressed changes in pH and the Hunter color values during storage. However, injection of calcium chloride and lactic acid had adverse effects on lipid oxidation and sensory characteristics. The higher TBARS values were observed in samples treated with calcium chloride and lactic acid when compared to control over the storage period. Addition of calcium chloride and lactic acid resulted in lower sensory scores for parameters tested, except odor and color, compared to control samples. Therefore, the formulation should be improved in order to overcome such defects prior to industrial application.

  8. Antimicrobial Effect of Calcium Chloride Alone and Combined with Lactic Acid Injected into Chicken Breast Meat

    PubMed Central

    Alahakoon, Amali U.; Jayasena, Dinesh D.; Jung, Samooel; Kim, Sun Hyo

    2014-01-01

    Chicken breast meat was injected with calcium chloride alone and in combination with lactic acid (0.01% and 0.002%, respectively). The inhibitory effects of the treatments on microbial growth were determined in the injected chicken breast meat stored at 4°C under aerobic packaging condition for 0, 3, and 7 d. Calcium chloride combined with 0.002% and 0.01% lactic acid reduced microbial counts by 0.14 and 1.08 Log CFU/g, respectively, however, calcium chloride alone was unable to inhibit microbial growth. Calcium chloride combined with 0.01% lactic acid was the most effective antimicrobial treatment and resulted in the highest initial redness value. Calcium chloride alone and combined with lactic acid suppressed changes in pH and the Hunter color values during storage. However, injection of calcium chloride and lactic acid had adverse effects on lipid oxidation and sensory characteristics. The higher TBARS values were observed in samples treated with calcium chloride and lactic acid when compared to control over the storage period. Addition of calcium chloride and lactic acid resulted in lower sensory scores for parameters tested, except odor and color, compared to control samples. Therefore, the formulation should be improved in order to overcome such defects prior to industrial application. PMID:26760942

  9. A calcium- and voltage-dependent chloride current in developing chick skeletal muscle.

    PubMed Central

    Hume, R I; Thomas, S A

    1989-01-01

    1. Depolarization of embryonic chick myotubes from negative potentials elicits a rapid spike followed by a long-duration after-potential. The ionic basis of the long-duration after-potential was examined by making intracellular recordings from cultured myotubes, and by making whole-cell patch-clamp recordings from myoblasts and myoballs. 2. The peak potential of the long-duration after-potential varied with the chloride gradient, suggesting that a conductance increase to chloride is involved in generating the after-potential. However, a calcium current was also implicated, since lowering the extracellular calcium or replacing extracellular calcium with cobalt abolished the after-potential. 3. When extracellular calcium was replaced with strontium or barium, short-duration spikes similar to calcium spikes were observed, but only strontium was able to support activation of long-duration after-potentials. Intracellular injection of calcium or strontium into myotubes bathed in calcium-free extracellular solutions restored the ability of depolarization to evoke an after-potential. Intracellular injection of magnesium, barium, nickel or cobalt did not restore this ability. These experiments strongly suggested that the long-duration after-potential was due to a calcium- and voltage-activated chloride current. 4. Whole-cell voltage-clamp recordings from myoballs and myoblasts showed that a large chloride conductance could be activated by depolarization when the internal free calcium concentration was buffered at levels greater than 10(-7) M. At 2.5 x 10(-7) M-calcium, the voltage dependence of activation was steepest in the range of -30 to -20 mV and the activation kinetics varied with the membrane potential. The time to half-maximal activation ranged from 0.1 s at positive potentials to greater than 1 s at more negative potentials. The time constant for deactivation was approximately 1 s at -50 mV. No inactivation was observed. 5. The selectivity of the chloride current

  10. Modulating the hydration behaviour of calcium chloride by lactam complexation.

    PubMed

    Perrin, Andrea; Musa, Osama M; Steed, Jonathan W

    2016-07-26

    Complexation of calcium chloride with bis(lactam) ligand L1 allows the formation of both an unstable anhydrous complex, an aqua complex {[Ca2(μ-L1)2(H2O)9]Cl4]}n (1) and a related hydrate incorporating additional lattice water of crystallization {[Ca(μ-L1)(H2O)5]Cl2·H2O}n (2). Related mono(lactam) L2 does not form aqua complexes but the anhydrous complex {[CaCl2(μ-L2)2]}n (3), is highly deliquescent. An unusual ethanol solvate is also reported {[CaCl2(L2)(EtOH)]}n (4).

  11. Modulating the hydration behaviour of calcium chloride by lactam complexation.

    PubMed

    Perrin, Andrea; Musa, Osama M; Steed, Jonathan W

    2016-07-26

    Complexation of calcium chloride with bis(lactam) ligand L1 allows the formation of both an unstable anhydrous complex, an aqua complex {[Ca2(μ-L1)2(H2O)9]Cl4]}n (1) and a related hydrate incorporating additional lattice water of crystallization {[Ca(μ-L1)(H2O)5]Cl2·H2O}n (2). Related mono(lactam) L2 does not form aqua complexes but the anhydrous complex {[CaCl2(μ-L2)2]}n (3), is highly deliquescent. An unusual ethanol solvate is also reported {[CaCl2(L2)(EtOH)]}n (4). PMID:27411017

  12. The Influence of Calcium Chloride Deicing Salt on Phase Changes and Damage Development in Cementitious Materials

    PubMed Central

    Farnam, Yaghoob; Dick, Sarah; Wiese, Andrew; Davis, Jeffrey; Bentz, Dale; Weiss, Jason

    2015-01-01

    The conventional CaCl2-H2O phase diagram is often used to describe how calcium chloride behaves when it is used on a concrete pavement undergoing freeze-thaw damage. However, the chemistry of the concrete can alter the appropriateness of using the CaCl2-H2O phase diagram. This study shows that the Ca(OH)2 present in a hydrated portland cement can interact with CaCl2 solution creating a behavior that is similar to that observed in isoplethal sections of a ternary phase diagram for a Ca(OH)2-CaCl2-H2O system. As such, it is suggested that such isoplethal sections provide a reasonable model that can be used to describe the behavior of concrete exposed to CaCl2 solution as the temperature changes. Specifically, the Ca(OH)2 can react with CaCl2 and H2O resulting in the formation of calcium oxychloride. The formation of the calcium oxychloride is expansive and can produce damage in concrete at temperatures above freezing. Its formation can also cause a significant decrease in fluid ingress into concrete. For solutions with CaCl2 concentrations greater than about 11.3 % (by mass), it is found that calcium oxychloride forms rapidly and is stable at room temperature (23 °C). PMID:26692655

  13. Upgrading Titanium Ore Through Selective Chlorination Using Calcium Chloride

    NASA Astrophysics Data System (ADS)

    Kang, Jungshin; Okabe, Toru H.

    2013-06-01

    To develop a simple and effective process for upgrading low-grade titanium ore (ilmenite, mainly FeTiO3), a new selective chlorination process based on the use of calcium chloride (CaCl2) as the chlorine source was investigated in this study. Titanium ore and a titanium ore/CaCl2 mixture were placed in two separate crucibles inside a gas-tight quartz tube that was then positioned in a horizontal furnace. In the experiments, the titanium ore in the two crucibles reacted with either HCl produced from CaCl2 or CaCl2 itself at 1100 K (827 °C), leading to the selective removal of the iron present in the titanium ore as iron chlorides [FeCl x (l,g) ( x = 2, 3)]. Various kinds of titanium ores produced in different countries were used as feedstock, and the influence of the particle size and atmosphere on the selective chlorination was investigated. Under certain conditions, titanium dioxide (TiO2) with purity of about 97 pct was directly obtained in a single step from titanium ore containing 51 pct TiO2. Thus, selective chlorination is a feasible method for producing high purity titanium dioxide from low-grade titanium ore.

  14. The effect of sodium chloride on the dissolution of calcium silicate hydrate gels.

    PubMed

    Hill, J; Harris, A W; Manning, M; Chambers, A; Swanton, S W

    2006-01-01

    The use of cement based materials will be widespread in the long-term management of radioactive materials in the United Kingdom. One of the applications could be the Nirex reference vault backfill (NRVB) as an engineered barrier within a deep geological repository. NRVB confers alkaline conditions, which would provide a robust chemical barrier through the control of the solubility of some key radionuclides, enhanced sorption and minimised corrosion of steel containers. An understanding of the dissolution of C-S-H gels in cement under the appropriate conditions (e.g., saline groundwaters) is necessary to demonstrate the expected evolution of the chemistry over time and to provide sufficient cement to buffer the porewater conditions for the required time. A programme of experimental work has been undertaken to investigate C-S-H gel dissolution behaviour in sodium chloride solutions and the effect of calcium/silicon ratio (C/S), temperature and cation type on this behaviour. Reductions in calcium concentration and pH values were observed with samples equilibrated at 45 degrees C compared to those prepared at 25 degrees C. The effect of salt cation type on salt-concentration dependence of the dissolution of C-S-H gels was investigated by the addition of lithium or potassium chloride in place of sodium chloride for gels with a C/S of 1.0 and 1.8. With a C/S of 1.0, similar increases in dissolved calcium concentration with increasing ionic strength were recorded for the different salts. However, at a C/S of 1.8, anomalously high calcium concentrations were observed in the presence of lithium.

  15. The effect of sodium chloride on the dissolution of calcium silicate hydrate gels

    SciTech Connect

    Hill, J. . E-mail: joanne.hill@nirex.co.uk; Harris, A.W.; Manning, M.; Chambers, A.; Swanton, S.W.

    2006-07-01

    The use of cement based materials will be widespread in the long-term management of radioactive materials in the United Kingdom. One of the applications could be the Nirex reference vault backfill (NRVB) as an engineered barrier within a deep geological repository. NRVB confers alkaline conditions, which would provide a robust chemical barrier through the control of the solubility of some key radionuclides, enhanced sorption and minimised corrosion of steel containers. An understanding of the dissolution of C-S-H gels in cement under the appropriate conditions (e.g., saline groundwaters) is necessary to demonstrate the expected evolution of the chemistry over time and to provide sufficient cement to buffer the porewater conditions for the required time. A programme of experimental work has been undertaken to investigate C-S-H gel dissolution behaviour in sodium chloride solutions and the effect of calcium/silicon ratio (C/S), temperature and cation type on this behaviour. Reductions in calcium concentration and pH values were observed with samples equilibrated at 45 deg. C compared to those prepared at 25 deg. C. The effect of salt cation type on salt-concentration dependence of the dissolution of C-S-H gels was investigated by the addition of lithium or potassium chloride in place of sodium chloride for gels with a C/S of 1.0 and 1.8. With a C/S of 1.0, similar increases in dissolved calcium concentration with increasing ionic strength were recorded for the different salts. However, at a C/S of 1.8, anomalously high calcium concentrations were observed in the presence of lithium.

  16. Modulating the textural characteristics of whey protein nanofibril gels with different concentrations of calcium chloride.

    PubMed

    Farjami, Toktam; Madadlou, Ashkan; Labbafi, Mohsen

    2016-02-01

    Protein nanofibrils with 10-20 nm diameters were formed by heating whey protein solution at pH 2.0. Nanofibrils solution was deacidified slowly through dialysis followed by adding different amounts of CaCl2 (0-80 mM) into the dialysis water resulting in formation of a soft viscoelastic gel over time. The gel fabricated from the nanofibrils solution dialyzed against distilled water with 0 mM CaCl2 had zero ash content. Fourier transform infra-red spectroscopy revealed a change in the pattern of hydrogen bond formation in gel network by calcium chloride. The higher the ash content of gels, the lower was the storage modulus and fracture stress of samples. Gels with higher ash contents had a more porous microstructure which was attributed to the diminished hydrophobic interactions and hydrogen bonding among nanofibrils by the action of chloride. Higher ash contents also led to higher water holding capacity of gels which was attributed to the influence of the strongly hydrated calcium ions that interacted with the non-charged regions of proteins via site-specific interactions.

  17. The electrowinning of copper from a cupric chloride solution

    NASA Astrophysics Data System (ADS)

    Lin, H. K.; Wu, X. J.; Rao, P. D.

    1991-08-01

    In this work, the Eh pCl diagram of the CuCl-H2O system was established, and the kinetics of copper dissolution in cupric chloride solution were studied with an emphasis on possible difficulties that may occur during copper electrowinning. The results were used to guide an investigation of copper electrowinning from cupric chloride solution.

  18. Raman spectroscopic studies of chemical speciation in calcium chloride melts

    SciTech Connect

    Windisch, Charles F.; Lavender, Curt A.

    2005-02-01

    Raman spectroscopy was applied to CaCl2 melts at 900 degrees C under both non-electrolyzed and electrolyzed conditions. The later used titania cathodes supplied by TIMET, Inc. and graphite anodes. Use of pulse-gating to collect the Raman spectra successfully eliminated any interference from black-body radiation and other stray light. The spectrum of molten CaCl2 exhibited no distinct, resolvable bands that could be correlated with a calcium chloride complex similar to MgCl42- in MgCl2 melts. Rather, the low frequency region of the spectrum was dominated by a broad “tail” arising from collective oscillations of both charge and mass in the molten salt “network.” Additions of both CaO and Ca at concentrations of a percent or two resulted in no new features in the spectra. Addition of CO2, both chemically and via electrolysis at concentrations dictated by stability and solubility at 900 degrees C and 1 bar pressure, also produced no new bands that could be correlated with either dissolved CO2 or the carbonate ion. These results indicated that Raman spectroscopy, at least under the conditions evaluated in the research, was not well suited for following the reactions and coordination chemistry of calcium ions, nor species such as dissolved metallic Ca and CO2 that are suspected to impact current efficiency in titanium electrolysis cells using molten CaCl2. Raman spectra of TIMET titania electrodes were successfully obtained as a function of temperature up to 900 degrees C, both in air and in-situ in CaCl2 melts. However, spectra of these electrodes could only be obtained when the material was in the unreduced state. When reduced, either with hydrogen or within an electrolysis cell, the resulting electrodes exhibited no measurable Raman bands under the conditions used in this work.

  19. Calcium sulphate in ammonium sulphate solution

    USGS Publications Warehouse

    Sullivan, E.C.

    1905-01-01

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

  20. Calmodulin-dependent activation and inactivation of anoctamin calcium-gated chloride channels.

    PubMed

    Vocke, Kerstin; Dauner, Kristin; Hahn, Anne; Ulbrich, Anne; Broecker, Jana; Keller, Sandro; Frings, Stephan; Möhrlen, Frank

    2013-10-01

    Calcium-dependent chloride channels serve critical functions in diverse biological systems. Driven by cellular calcium signals, the channels codetermine excitatory processes and promote solute transport. The anoctamin (ANO) family of membrane proteins encodes three calcium-activated chloride channels, named ANO 1 (also TMEM16A), ANO 2 (also TMEM16B), and ANO 6 (also TMEM16F). Here we examined how ANO 1 and ANO 2 interact with Ca(2+)/calmodulin using nonstationary current analysis during channel activation. We identified a putative calmodulin-binding domain in the N-terminal region of the channel proteins that is involved in channel activation. Binding studies with peptides indicated that this domain, a regulatory calmodulin-binding motif (RCBM), provides two distinct modes of interaction with Ca(2+)/calmodulin, one at submicromolar Ca(2+) concentrations and one in the micromolar Ca(2+) range. Functional, structural, and pharmacological data support the concept that calmodulin serves as a calcium sensor that is stably associated with the RCBM domain and regulates the activation of ANO 1 and ANO 2 channels. Moreover, the predominant splice variant of ANO 2 in the brain exhibits Ca(2+)/calmodulin-dependent inactivation, a loss of channel activity within 30 s. This property may curtail ANO 2 activity during persistent Ca(2+) signals in neurons. Mutagenesis data indicated that the RCBM domain is also involved in ANO 2 inactivation, and that inactivation is suppressed in the retinal ANO 2 splice variant. These results advance the understanding of Ca(2+) regulation in anoctamin Cl(-) channels and its significance for the physiological function that anoctamin channels subserve in neurons and other cell types.

  1. Electrolysis of dilute sodium chloride solution in a diaphragm cell

    SciTech Connect

    Kubasov, V.L.; Ivanter, I.A.; Druzhinin, E.A.; Vorob'eva, V.B.

    1986-02-10

    In some cases, as in the production of iodine and bromine, dilute solutions of sodium chloride remain unutilized. In view of the existence of large amounts of unutilized spent sodium chloride solutions and their harmful effect when discharged into the environment, it is desirable to develop a process for production of chlorine and alkali with high current efficiencies, satisfying industrial requirements, from dilute sodium chloride solutions. The authors have therefore studied electrolysis of solutions containing 160 and 180 kg/m/sup 3/ of sodium chloride, having pH of 11.0-11.5, close in composition to solutions from the Cheleken chemical factory. The chlorine and alkali current efficiencies and the compositions of the anolyte, catholyte, and anode gas were determined.

  2. Heat storage material comprising calcium chloride-hexahydrate and a nucleating agent

    SciTech Connect

    Gawron, K.; Schroder, J.

    1980-02-19

    The utility of calcium chloride-hexahydrate as a heat storage material is improved when barium carbonate, strontium carbonate, barium fluoride, barium fluoride-hydrofluoride and/or strontium fluoride is used as a nucleating agent to prevent supercooling.

  3. Commercial Scale Cucumber Fermentations Brined with Calcium Chloride Instead of Sodium Chloride.

    PubMed

    Pérez-Díaz, I M; McFeeters, R F; Moeller, L; Johanningsmeier, S D; Hayes, J; Fornea, D S; Rosenberg, L; Gilbert, C; Custis, N; Beene, K; Bass, D

    2015-12-01

    Development of low salt cucumber fermentation processes present opportunities to reduce the amount of sodium chloride (NaCl) that reaches fresh water streams from industrial activities. The objective of this research was to translate cucumber fermentation brined with calcium chloride (CaCl2 ) instead of NaCl to commercial scale production. Although CaCl2 brined cucumber fermentations were stable in laboratory experiments, commercial scale trials using 6440 L open-top tanks rapidly underwent secondary cucumber fermentation. It was understood that a limited air purging routine, use of a starter culture and addition of preservatives to the cover brine aids in achieving the desired complete cucumber fermentation. The modified process was used for subsequent commercial trials using 12490 and 28400 L open-top tanks packed with variable size cucumbers and from multiple lots, and cover brines containing CaCl2 and potassium sorbate to equilibrated concentrations of 100 and 6 mM, respectively. Lactobacillus plantarum LA0045 was inoculated to 10(6) CFU/mL, and air purging was applied for two 2-3 h periods per day for the first 10 d of fermentation and one 2-3 h period per day between days 11 and 14. All fermentations were completed, as evidenced by the full conversion of sugars to lactic acid, decrease in pH to 3.0, and presented microbiological stability for a minimum of 21 d. This CaCl2 process may be used to produce fermented cucumbers intended to be stored short term in a manner that reduces pollution and waste removal costs. PMID:26512798

  4. Commercial Scale Cucumber Fermentations Brined with Calcium Chloride Instead of Sodium Chloride.

    PubMed

    Pérez-Díaz, I M; McFeeters, R F; Moeller, L; Johanningsmeier, S D; Hayes, J; Fornea, D S; Rosenberg, L; Gilbert, C; Custis, N; Beene, K; Bass, D

    2015-12-01

    Development of low salt cucumber fermentation processes present opportunities to reduce the amount of sodium chloride (NaCl) that reaches fresh water streams from industrial activities. The objective of this research was to translate cucumber fermentation brined with calcium chloride (CaCl2 ) instead of NaCl to commercial scale production. Although CaCl2 brined cucumber fermentations were stable in laboratory experiments, commercial scale trials using 6440 L open-top tanks rapidly underwent secondary cucumber fermentation. It was understood that a limited air purging routine, use of a starter culture and addition of preservatives to the cover brine aids in achieving the desired complete cucumber fermentation. The modified process was used for subsequent commercial trials using 12490 and 28400 L open-top tanks packed with variable size cucumbers and from multiple lots, and cover brines containing CaCl2 and potassium sorbate to equilibrated concentrations of 100 and 6 mM, respectively. Lactobacillus plantarum LA0045 was inoculated to 10(6) CFU/mL, and air purging was applied for two 2-3 h periods per day for the first 10 d of fermentation and one 2-3 h period per day between days 11 and 14. All fermentations were completed, as evidenced by the full conversion of sugars to lactic acid, decrease in pH to 3.0, and presented microbiological stability for a minimum of 21 d. This CaCl2 process may be used to produce fermented cucumbers intended to be stored short term in a manner that reduces pollution and waste removal costs.

  5. Distinct roles for sodium, chloride, and calcium in excitotoxic dendritic injury and recovery.

    PubMed

    Hasbani, M J; Hyrc, K L; Faddis, B T; Romano, C; Goldberg, M P

    1998-11-01

    The postsynaptic neuronal dendrite is selectively vulnerable to hypoxic-ischemic brain injury and glutamate receptor overactivation. We explored the glutamate receptor pharmacology and ionic basis of rapid, reversible alterations in dendritic shape which occur in cultured neurons exposed to glutamate. Dendrite morphology was assessed with the fluorescent membrane tracer, DiI, or immunofluorescence labeling of the somatodendritic protein, MAP2. Cortical cultures derived from 15-day-old mouse embryos underwent segmental dendritic beading when exposed to NMDA, AMPA, or kainate, but not to metabotropic glutamate receptor agonists. Varicosity formation in response to NMDA or kainate application was substantially attenuated in reduced sodium buffer (substituted with N-methyl-D-glucamine). Furthermore, veratridine-induced sodium entry mimicked excitotoxic alterations in dendrites and additionally caused varicosity formation in axons. Solutions deficient in chloride (substituted with Na methylsulfate) and antagonists of chloride-permeable GABA/glycine receptors reduced NMDA- or kainate-induced varicosity formation. An increase in dendrite volume was observed as varicosities formed, and varicosity formation was attenuated in sucrose-supplemented hypertonic media. Despite marked structural changes affecting virtually all neurons, dendrite shape returned to normal within 2 h of terminating glutamate receptor agonist application. Neurons exposed to kainate recovered more rapidly than those exposed to NMDA, and neurons exposed to NMDA in calcium-free buffer recovered more rapidly than cells treated with NMDA in normal buffer. While sodium, chloride, and water entry contribute to excitotoxic dendritic injury acutely, calcium entry through NMDA receptors results in lasting structural changes in damaged dendrites.

  6. Effect of calcium chloride on physical properties of calcium-enriched mixture cement.

    PubMed

    Abbaszadegan, Abbas; Sedigh Shams, Mahdi; Jamshidi, Yasin; Parashos, Peter; Bagheri, Rafat

    2015-12-01

    The aim of this study was to evaluate the effect of adding 10% calcium chloride (CaCl2) on the setting time, solubility and the pH of calcium-enriched mixture (CEM) cement. Setting time was assessed in accordance with American Dental Association specification N°57. Solubility was measured at 24 and 72 h, 7 and 14 days in hydrated and dehydrated conditions by calculating weight change. The pH of MiliQ water in which the CEM cement samples were immersed was measured immediately after each time interval with and without the addition of CaCl2. The data were analysed using the Mann-Whitney U-test and the Student's t-test. The initial setting time was significantly decreased after the addition of 10% CaCl2. The pH of water increased immediately when in contact with the cements in both groups. The weight loss of hydrated and dehydrated specimens was more than 3% and was significantly reduced by the addition of 10% CaCl2.

  7. Initial Observations of the Effects of Calcium Chloride Infusions in Pediatric Patients with Low Cardiac Output.

    PubMed

    Averin, Konstantin; Villa, Chet; Krawczeski, Catherine D; Pratt, Jesse; King, Eileen; Jefferies, John L; Nelson, David P; Cooper, David S; Ryan, Thomas D; Sawyer, Jaclyn; Towbin, Jeffrey A; Lorts, Angela

    2016-03-01

    Myocardial contractility and relaxation are highly dependent on calcium homeostasis. Immature myocardium, as in pediatric patients, is thought to be more dependent on extracellular calcium for optimal function. For this reason, intravenous calcium chloride infusions may improve myocardial function in the pediatric patient. The objectives of this study were to report the hemodynamic changes seen after administration of continuous calcium chloride to critically ill children. We retrospectively identified pediatric patients (newborn to 17 years old) with hemodynamic instability admitted to the cardiac ICU between May 2011 and May 2012 who received a continuous infusion of calcium chloride. The primary outcome was improvement in cardiac output, assessed by arterial-mixed venous oxygen saturation (A-V) difference. Sixty-eight patients, mean age 0.87 ± 2.67 years, received a total of 116 calcium infusions. Calcium chloride infusions resulted in significant improvements in primary and secondary measures of cardiac output at 2 and 6 h. Six hours after calcium initiation, A-V oxygen saturation difference decreased by 7.4 % (32.6 ± 2.1 to 25.2 ± 2.0 %, p < 0.001), rSO2 increased by 5.5 % (63.1 vs 68.6 %, p < 0.001), and serum lactate decreased by 0.9 mmol/l (3.3 vs 2.4 mmol/l, p < 0.001) with no change in HR (149.1 vs 145.6 bpm p = 0.07). Urine output increased 0.66 ml/kg/h in the 8-h period after calcium initiation when compared to pre-initiation (p = 0.003). Neonates had the strongest evidence of effectiveness with other age groups trending toward significance. Calcium chloride infusions improve markers of cardiac output in a heterogenous group of pediatric patients in a cardiac ICU. Neonates appear to derive the most benefit from utilization of these infusions.

  8. Effect of calcium chloride on gross behavioural changes produced by carbachol and eserine in cats.

    PubMed

    Beleslin, D B; Samardzic, R; Krstić, S K; Strbac, M

    1982-01-01

    The effect of calcium chloride injected into the cerebral ventricles of group-housed unanaesthetized cats upon vocalization (rage, hissing and snarling), fighting (attack with paws and claws, defense with paws and claws and biting), mydriasis, tremor and clonic-tonic convulsions produced by carbachol and eserine injected similarly was investigated. Calcium chloride depressed or almost completely abolished the vocalization and fighting due to carbachol and eserine. On the other hand, mydriasis, tremor and clonic-tonic convulsions evoked by carbachol and eserine were not significantly changed by calcium chloride. It is apparent that calcium chloride can "dissociate" vocalization and fighting from autonomic and motor phenomena such as mydriasis, tremor and clonic-tonic convulsions caused by carbachol and eserine. Calcium chloride inhibited the vocalization and fighting produced by carbachol and eserine most probably by a nonspecific stabilizing action on central muscarinic cholinoceptive sites. These results further support the view that calcium ions in excess have an atropine-like action also in the central nervous system. PMID:6892185

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

    PubMed

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

    1997-04-01

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

  10. SOLVENT EXTRACTION PROCESS FOR URANIUM FROM CHLORIDE SOLUTIONS

    DOEpatents

    Blake, C.A. Jr.; Brown, K.B.; Horner, D.E.

    1960-05-24

    An improvement was made in a uranium extraction process wherein the organic extractant is a phosphine oxide. An aqueous solution containing phosphate ions or sulfate ions together with uranium is provided with a source of chloride ions during the extraction step. The presence of the chloride ions enables a phosphine oxide to extract uranium in the presence of strong uranium- complexing ions such as phosphate or sulfate ions.

  11. Coagulation of β-conglycinin, glycinin and isoflavones induced by calcium chloride in soymilk.

    PubMed

    Hsiao, Yu-Hsuan; Yu, Chia-Jung; Li, Wen-Tai; Hsieh, Jung-Feng

    2015-08-11

    The coagulation of β-conglycinin (7S), glycinin (11S) and isoflavones induced by calcium chloride was investigated. Approximately 92.6% of the soymilk proteins were coagulated into the soymilk pellet fraction (SPF) after the addition of 5 mM calcium chloride. SDS-PAGE and two-dimensional electrophoresis analysis indicated that most of the 7S (α', α and β), 11S acidic (A1a, A1b, A2, A3 and A4) and 11S basic (B1a) proteins in the SSF were coagulated into the SPF after treatment with 5 mM calcium chloride. Isoflavones, including daidzein and genistein, were also coagulated into the SPF after the addition of 5 mM calcium chloride. The amounts of daidzein and genistein in the SSF decreased to 39.4 ± 1.6 and 11.8 ± 7.0%, respectively. HPLC analysis suggested that daidzein and genistein were bound with 7S and 11S proteins and then were coprecipitated into the SPF by 5 mM calcium chloride.

  12. Coagulation of β-conglycinin, glycinin and isoflavones induced by calcium chloride in soymilk

    NASA Astrophysics Data System (ADS)

    Hsiao, Yu-Hsuan; Yu, Chia-Jung; Li, Wen-Tai; Hsieh, Jung-Feng

    2015-08-01

    The coagulation of β-conglycinin (7S), glycinin (11S) and isoflavones induced by calcium chloride was investigated. Approximately 92.6% of the soymilk proteins were coagulated into the soymilk pellet fraction (SPF) after the addition of 5 mM calcium chloride. SDS-PAGE and two-dimensional electrophoresis analysis indicated that most of the 7S (α’, α and β), 11S acidic (A1a, A1b, A2, A3 and A4) and 11S basic (B1a) proteins in the SSF were coagulated into the SPF after treatment with 5 mM calcium chloride. Isoflavones, including daidzein and genistein, were also coagulated into the SPF after the addition of 5 mM calcium chloride. The amounts of daidzein and genistein in the SSF decreased to 39.4 ± 1.6 and 11.8 ± 7.0%, respectively. HPLC analysis suggested that daidzein and genistein were bound with 7S and 11S proteins and then were coprecipitated into the SPF by 5 mM calcium chloride.

  13. ANO2 is the cilial calcium-activated chloride channel that may mediate olfactory amplification

    PubMed Central

    Stephan, Aaron B.; Shum, Eleen Y.; Hirsh, Sarah; Cygnar, Katherine D.; Reisert, Johannes; Zhao, Haiqing

    2009-01-01

    For vertebrate olfactory signal transduction, a calcium-activated chloride conductance serves as a major amplification step. However, the molecular identity of the olfactory calcium-activated chloride channel (CaCC) is unknown. Here we report a proteomic screen for cilial membrane proteins of mouse olfactory sensory neurons (OSNs) that identified all the known olfactory transduction components as well as Anoctamin 2 (ANO2). Ano2 transcripts were expressed specifically in OSNs in the olfactory epithelium, and ANO2::EGFP fusion protein localized to the OSN cilia when expressed in vivo using an adenoviral vector. Patch-clamp analysis revealed that ANO2, when expressed in HEK-293 cells, forms a CaCC and exhibits channel properties closely resembling the native olfactory CaCC. Considering these findings together, we propose that ANO2 constitutes the olfactory calcium-activated chloride channel. PMID:19561302

  14. Molecular dynamics studies of lanthanum chloride solutions

    SciTech Connect

    Meier, W.; Bopp, Ph. ); Probst, M.M. ); Spohr, E. ); Lin, J.L. )

    1990-05-31

    Molecular dynamics studies are reported for LaCl{sub 3} solutions at two different concentrations and temperatures, and for isolated aqueous La{sup 3+} ions. Ion-water clusters La(H{sub 2}O){sub n}{sup 3+} with n = 61 and n = 100 and systems consisting of one ion and 100 or 200 water molecules in the usual periodic box, as well as solutions of 7 (4) cations and 21 (12) anions in 190 (200) water molecules, corresponding to 2 and 1.1 m solutions, respectively, were investigated. The 2 m solution was investigated at two different temperatures. The results for the static structure, with special emphasis on the hydration structure of the La{sup 3+} ion, are discussed in terms of radial distribution functions and resulting hydration numbers, and various other correlations. These results are compared with X-ray data and discussed in light of the hydration numbers observed for aqueous ions in general.

  15. The calcium-activated chloride channel Anoctamin 1 contributes to the regulation of renal function.

    PubMed

    Faria, Diana; Rock, Jason R; Romao, Ana M; Schweda, Frank; Bandulik, Sascha; Witzgall, Ralph; Schlatter, Eberhard; Heitzmann, Dirk; Pavenstädt, Hermann; Herrmann, Edwin; Kunzelmann, Karl; Schreiber, Rainer

    2014-06-01

    The role of calcium-activated chloride channels for renal function is unknown. By immunohistochemistry we demonstrate dominant expression of the recently identified calcium-activated chloride channels, Anoctamin 1 (Ano1, TMEM16A) in human and mouse proximal tubular epithelial (PTE) cells, with some expression in podocytes and other tubular segments. Ano1-null mice had proteinuria and numerous large reabsorption vesicles in PTE cells. Selective knockout of Ano1 in podocytes (Ano1-/-/Nphs2-Cre) did not impair renal function, whereas tubular knockout in Ano1-/-/Ksp-Cre mice increased urine protein excretion and decreased urine electrolyte concentrations. Purinergic stimulation activated calcium-dependent chloride currents in isolated proximal tubule epithelial cells from wild-type but not from Ano1-/-/Ksp-Cre mice. Ano1 currents were activated by acidic pH, suggesting parallel stimulation of Ano1 chloride secretion with activation of the proton-ATPase. Lack of calcium-dependent chloride secretion in cells from Ano1-/-/Ksp-Cre mice was paralleled by attenuated proton secretion and reduced endosomal acidification, which compromised proximal tubular albumin uptake. Tubular knockout of Ano1 enhanced serum renin and aldosterone concentrations, probably leading to enhanced compensatory distal tubular reabsorption, thus maintaining normal blood pressure levels. Thus, Ano1 has a role in proximal tubular proton secretion and protein reabsorption. The results correspond to regulation of the proton-ATPase by the Ano1-homolog Ist2 in yeast.

  16. REMOVAL OF CHLORIDE FROM ACIDIC SOLUTIONS USING NO2

    SciTech Connect

    Visser, A; Robert Pierce, R; James Laurinat, J

    2006-08-22

    Chloride (Cl{sup -}) salt processing in strong acids is used to recycle plutonium (Pu) from pyrochemical residues. The Savannah River National Laboratory (SRNL) is studying the potential application of nitrogen dioxide (NO{sub 2}) gas to effectively convert dissolved pyrochemical salt solutions to chloride-free solutions and improve recovery operations. An NO{sub 2} sparge has been shown to effectively remove Cl{sup -} from solutions containing 6-8 M acid (H{sup +}) and up to 5 M Cl{sup -}. Chloride removal occurs as a result of the competition of at least two reactions, one which is acid-dependent. Below 4 M H+, NO2 reacts with Cl- to produce nitrosyl chloride (ClNO). Between 6 M and 8 M H{sup +}, the reaction of hydrochloric acid (HCl) with nitric acid (HNO{sub 3}), facilitated by the presence of NO{sub 2}, strongly affects the rate of Cl{sup -} removal. The effect of heating the acidic Cl{sup -} salt solution without pre-heating the NO{sub 2} gas has minimal effect on Cl{sup -} removal rates when the contact times between NO{sub 2} and the salt solution are on the order of seconds.

  17. Anoctamin Calcium-Activated Chloride Channels May Modulate Inhibitory Transmission in the Cerebellar Cortex.

    PubMed

    Zhang, Weiping; Schmelzeisen, Steffen; Parthier, Daniel; Frings, Stephan; Möhrlen, Frank

    2015-01-01

    Calcium-activated chloride channels of the anoctamin (alias TMEM16) protein family fulfill critical functions in epithelial fluid transport, smooth muscle contraction and sensory signal processing. Little is known, however, about their contribution to information processing in the central nervous system. Here we examined the recent finding that a calcium-dependent chloride conductance impacts on GABAergic synaptic inhibition in Purkinje cells of the cerebellum. We asked whether anoctamin channels may underlie this chloride conductance. We identified two anoctamin channel proteins, ANO1 and ANO2, in the cerebellar cortex. ANO1 was expressed in inhibitory interneurons of the molecular layer and the granule cell layer. Both channels were expressed in Purkinje cells but, while ANO1 appeared to be retained in the cell body, ANO2 was targeted to the dendritic tree. Functional studies confirmed that ANO2 was involved in a calcium-dependent mode of ionic plasticity that reduces the efficacy of GABAergic synapses. ANO2 channels attenuated GABAergic transmission by increasing the postsynaptic chloride concentration, hence reducing the driving force for chloride influx. Our data suggest that ANO2 channels are involved in a Ca2+-dependent regulation of synaptic weight in GABAergic inhibition. Thus, in balance with the chloride extrusion mechanism via the co-transporter KCC2, ANO2 appears to regulate ionic plasticity in the cerebellum.

  18. Anoctamin Calcium-Activated Chloride Channels May Modulate Inhibitory Transmission in the Cerebellar Cortex.

    PubMed

    Zhang, Weiping; Schmelzeisen, Steffen; Parthier, Daniel; Frings, Stephan; Möhrlen, Frank

    2015-01-01

    Calcium-activated chloride channels of the anoctamin (alias TMEM16) protein family fulfill critical functions in epithelial fluid transport, smooth muscle contraction and sensory signal processing. Little is known, however, about their contribution to information processing in the central nervous system. Here we examined the recent finding that a calcium-dependent chloride conductance impacts on GABAergic synaptic inhibition in Purkinje cells of the cerebellum. We asked whether anoctamin channels may underlie this chloride conductance. We identified two anoctamin channel proteins, ANO1 and ANO2, in the cerebellar cortex. ANO1 was expressed in inhibitory interneurons of the molecular layer and the granule cell layer. Both channels were expressed in Purkinje cells but, while ANO1 appeared to be retained in the cell body, ANO2 was targeted to the dendritic tree. Functional studies confirmed that ANO2 was involved in a calcium-dependent mode of ionic plasticity that reduces the efficacy of GABAergic synapses. ANO2 channels attenuated GABAergic transmission by increasing the postsynaptic chloride concentration, hence reducing the driving force for chloride influx. Our data suggest that ANO2 channels are involved in a Ca2+-dependent regulation of synaptic weight in GABAergic inhibition. Thus, in balance with the chloride extrusion mechanism via the co-transporter KCC2, ANO2 appears to regulate ionic plasticity in the cerebellum. PMID:26558388

  19. Anoctamin Calcium-Activated Chloride Channels May Modulate Inhibitory Transmission in the Cerebellar Cortex

    PubMed Central

    Parthier, Daniel; Frings, Stephan; Möhrlen, Frank

    2015-01-01

    Calcium-activated chloride channels of the anoctamin (alias TMEM16) protein family fulfill critical functions in epithelial fluid transport, smooth muscle contraction and sensory signal processing. Little is known, however, about their contribution to information processing in the central nervous system. Here we examined the recent finding that a calcium-dependent chloride conductance impacts on GABAergic synaptic inhibition in Purkinje cells of the cerebellum. We asked whether anoctamin channels may underlie this chloride conductance. We identified two anoctamin channel proteins, ANO1 and ANO2, in the cerebellar cortex. ANO1 was expressed in inhibitory interneurons of the molecular layer and the granule cell layer. Both channels were expressed in Purkinje cells but, while ANO1 appeared to be retained in the cell body, ANO2 was targeted to the dendritic tree. Functional studies confirmed that ANO2 was involved in a calcium-dependent mode of ionic plasticity that reduces the efficacy of GABAergic synapses. ANO2 channels attenuated GABAergic transmission by increasing the postsynaptic chloride concentration, hence reducing the driving force for chloride influx. Our data suggest that ANO2 channels are involved in a Ca2+-dependent regulation of synaptic weight in GABAergic inhibition. Thus, in balance with the chloride extrusion mechanism via the co-transporter KCC2, ANO2 appears to regulate ionic plasticity in the cerebellum. PMID:26558388

  20. Interdependence between sodium transport, external chloride, and sodium/calcium exchanger in the isolated skin of the Rana pipiens.

    PubMed

    Soto, C; Aguilar, G; Jiménez, L

    2001-01-01

    The aim of this study was to analyze the relationship of the Na+/Ca2+ exchanger, cytosolic calcium, and chloride to the transepithelial transport of sodium in isolated frog skin. Sodium transport was measured as amiloride-inhibitable short circuit current (SCC). We studied the effect of variations in the concentrations of external chloride and of the manipulation of calcium on sensitive amiloride SCC. Modifications in the movement of Ca2+ were induced by an ionophore, A23187, and a Ca2+ channel blocker, nifedipine. Calcium ionophore A23187 (5 and 20 microM), in a normal Ringer's solution, increased SCC and transepithelial potential difference (PD). In contrast, nifedipine (20 microM) reduced SCC and PD. The role of the Na+/Ca2+ exchanger was studied using dichlorobenzamil (DCB, 50 microM) and quinacrine (1 mM), inhibitors of this exchanger. They selectively increased SCC and PD on the mucosal side of the skin, with no effect on the serosal side. This response occurred only in the presence of extracellular calcium. Replacement of NaCl by sodium methanesulfonate or the addition of furosemide (1 mM) at the serosal compartment, decreased basal SCC and PD and blocked the response to A23187 and the mucosal effect of DCB and quinacrine. These results suggest the presence of an Na+/Ca2+ exchanger located on the mucosal side of the frog skin, which participates in the transepithelial sodium transport. The action of this exchanger may be modulated by external chloride and calcium. J. Exp. Zool. 289:23-32, 2001.

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

    NASA Astrophysics Data System (ADS)

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

    2016-08-01

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

  2. Physicochemical changes in dry-cured hams salted with potassium, calcium and magnesium chloride as a partial replacement for sodium chloride.

    PubMed

    Aliño, M; Grau, R; Toldrá, F; Barat, J M

    2010-10-01

    The reduction of added sodium chloride in dry-cured ham has been proposed to reduce dietary sodium intake in Mediterranean countries. The effect of substituting sodium chloride with potassium chloride, calcium chloride and magnesium chloride on some physicochemical characteristics of dry-cured ham during processing was evaluated. The results showed that hams salted with a mixture of sodium and potassium chloride registered higher salt concentrations and lower water contents and thus, needed less time to reach the required weight loss at the end of the process. The opposite effect was observed when calcium and magnesium chloride were added to the salt mixture. The observed differences in the texture and colour parameters were mainly due to differences in water and salt content.

  3. Corrosion inhibitors in concrete. Part II: Effect on chloride threshold values for corrosion of steel in synthetic pore solutions

    SciTech Connect

    Mammoliti, L.; Hansson, C.M.; Hope, B.B.

    1999-10-01

    The effectiveness of four commercially available corrosion inhibitors for use in cement-based materials was assessed in synthetic concrete pore solution containing chlorides. The effect of the surface topography of the sample and the composition of the pore solution was also assessed. Although in a parallel study the inhibitors were observed to delay the onset of corrosion, in these tests in pore solution they were found to be ineffective in increasing the chloride threshold value of reinforcing steel exposed to chlorides and had little influence on the progression of corrosion once initiated. This suggests that chemical reactions within the cement phase are responsible for the observed results. Metallographically polished samples proved the most resistant to corrosion regardless of electrolyte composition and samples with all surface finishes exhibited lower resistance in solutions containing only calcium hydroxide than in the higher pH synthetic concrete pore solutions.

  4. [Properties of benzethonium chloride in micellar solutions and the effect of added sodium chloride].

    PubMed

    Kopecký, F; Kopecká, B; Kaclík, P

    2006-07-01

    Aqueous solutions of the antimicrobially effective quaternary ammonium salt benzethonium chloride (hyamine 1622) were studied using UV spectrophotometry and partially conductometry. The spectra of micellar solutions of benzethonium chloride revealed a concentration-dependent bathochromic and hyperchromic shift of a weak UV absorption band in the region 250-300 nm. This served to elaborate the spectrophotometric determination of the critical micellar concentration (CMC) of benzethonium chloride and the concentration of free benzethonium cations in micellar solutions without an addition of NaCl and with a constant addition of NaCl 0.003, 0.1 and 0.15 mol/l. Premicellar associations were not observed and in NaCl-free solutions CMC 0.0028 mol/l was spectrophotometrically determined. An addition of NaCl resulted in an increased hyperchromic effect and strengthening of micellization, manifested by a more than ten-times decrease in the CMC as well as the concentration of free benzethonium cations in micellar solutions. The courses of the determined concentrations of free benzethonium cations in the solutions both without and with the presence of NaCl were quite similar; their maximal values were always just a little higher than the corresponding CMC and with a further growth of the total concentration of benzethonium chloride there was, on the other hand, a marked decrease in the concentration of its free cations in micellar solution. Possible effects of a decreased concentration of free benzethonium cations due to an added electrolyte on antimicrobial activity and formation of ionic pairs are discussed.

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

    NASA Technical Reports Server (NTRS)

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

    1998-01-01

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

  6. Hydration patterns and salting effects in sodium chloride solution.

    PubMed

    Li, Weifeng; Mu, Yuguang

    2011-10-01

    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.

  7. Consumer acceptability of cucumber pickles produced by fermentation in calcium chloride brine for reduced environmental impact

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fermentation of cucumbers in calcium chloride brine has been proposed as an alternative process to reduce the environmental impact of traditional, high salt fermentations. The objective of this research was to determine whether consumer acceptability of pickle products would be impacted by fermentat...

  8. Critical evaluation of the thermodynamic properties of aqueous calcium chloride. 1: Osmotic and activity coefficients of 0--10.77 mol/kg aqueous calcium chloride solutions at 298.15 K and correlation with extended Pitzer ion-interaction models

    SciTech Connect

    Rard, J.A.; Clegg, S.L.

    1997-09-01

    Isopiestic vapor-pressure measurements were performed at 298.15 K for CaCl{sub 2}(aq) solutions at 66 molalities from (4.3235 to 10.253) mol/kg, using H{sub 2}SO{sub 4}(aq) as the reference standard, with emphasis given to the accurate characterization of the osmotic coefficients near and above saturation. Published isopiestic molalities, direct vapor pressures, and emf results for CaCl{sub 2}(aq) have been critically reevaluated and recalculated in an internally consistent manner. This critically-assessed database was used to evaluate the parameters of Pitzer`s equations and various extended forms at 298.15 K and 0.1 MPa. Neither the standard equations nor empirically extended versions were able to represent the thermodynamic results over more than part of the molality range without large cyclic systematic deviations. It was possible, however, to obtain essentially quantitative agreement between experiment and model over the full molality range if (1) the presence of CaCl{sup +}(aq) ion pairs was included explicitly and (2) higher-order virial terms were included. One such quantitative model is presented here in detail. Without these higher-order virial terms the same model is able to represent the {phi}(CaCl{sub 2}) fairly well only to about 8 mol/kg. The osmotic coefficient of CaCl{sub 2}(aq) goes through a minimum around 0.11 mol/kg, which is followed by a regular increase with molality to a broad maximum in the supersaturated molality region where {phi}(CaCl{sub 2}) is nearly constant at 3.169--3.173 from about (8.5 to 9.5) mol/kg. It then decreases slightly by about 0.3% at higher molalities.

  9. Inactivation of biological agents using neutral oxone-chloride solutions.

    PubMed

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

    2006-04-15

    Bleach solutions containing the active ingredient hypochlorite (OCl-) serve as powerful biological disinfectants but are highly caustic and present a significant compatibility issue when applied to contaminated equipment or terrain. A neutral, bicarbonate-buffered aqueous solution of Oxone (2K2HSO5.KHSO4.K2SO4) and sodium chloride that rapidly generates hypochlorite and hypochlorous acid (HOCl) in situ was evaluated as a new alternative to bleach for the inactivation of biological agents. The solution produced a free chlorine (HOCl + OCl-) concentration of 3.3 g/L and achieved > or =5.8-log inactivation of spores of Bacillus atrophaeus, Bacillus thuringiensis, Aspergillus niger, and Escherichia coli vegetative cells in 1 min at 22 degrees C. Seawaterwas an effective substitute for solid sodium chloride and inactivated 5 to 8 logs of each organism in 10 min over temperatures ranging from -5 degrees C to 55 degrees C. Sporicidal effectiveness increased as free chlorine concentrations shifted from OCl- to HOCl. Neutrally buffered Oxone-chloride and Oxone-seawater solutions are mitigation alternatives for biologically contaminated equipment and environments that would otherwise be decontaminated using caustic bleach solutions.

  10. Inactivation of biological agents using neutral oxone-chloride solutions.

    PubMed

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

    2006-04-15

    Bleach solutions containing the active ingredient hypochlorite (OCl-) serve as powerful biological disinfectants but are highly caustic and present a significant compatibility issue when applied to contaminated equipment or terrain. A neutral, bicarbonate-buffered aqueous solution of Oxone (2K2HSO5.KHSO4.K2SO4) and sodium chloride that rapidly generates hypochlorite and hypochlorous acid (HOCl) in situ was evaluated as a new alternative to bleach for the inactivation of biological agents. The solution produced a free chlorine (HOCl + OCl-) concentration of 3.3 g/L and achieved > or =5.8-log inactivation of spores of Bacillus atrophaeus, Bacillus thuringiensis, Aspergillus niger, and Escherichia coli vegetative cells in 1 min at 22 degrees C. Seawaterwas an effective substitute for solid sodium chloride and inactivated 5 to 8 logs of each organism in 10 min over temperatures ranging from -5 degrees C to 55 degrees C. Sporicidal effectiveness increased as free chlorine concentrations shifted from OCl- to HOCl. Neutrally buffered Oxone-chloride and Oxone-seawater solutions are mitigation alternatives for biologically contaminated equipment and environments that would otherwise be decontaminated using caustic bleach solutions. PMID:16683620

  11. The effect of calcium chloride on growth, photosynthesis, and antioxidant responses of Zoysia japonica under drought conditions.

    PubMed

    Xu, Chengbin; Li, Xuemei; Zhang, Lihong

    2013-01-01

    Few attempts have been made to study the alleviating effects of signal molecules on zoysiagrass (Zoysiajaponica) under drought stress. Calcium chloride has been shown to ameliorate the adverse effects of drought stress on many plants. It is necessary to investigate how to enhance drought tolerance of zoysiagrass using calcium chloride. The study elucidated the effects of calcium chloride on zoysiagrass under drought conditions by investigating the following parameters: biomass, chlorophyll (Chl) content, net photosynthetic rate (Pn), chlorophyll fluorescence, antioxidant enzymes, proline content, and malondialdehyde (MDA) content. Experimental conditions consisted of an aqueous CaCl2 solution at 5, 10, and 20 mM sprayed on zoysiagrass leaves for 3 d, following by an inducement of drought conditions by withholding water for 16 d. Under drought conditions, all CaCl2 pretreatments were found to increase the above-ground fresh biomass, as well as below-ground fresh and dry biomass. The resulting Chl (a, b, a+b) contents of the 5 and 10 mM CaCl2 pretreatment groups were higher than those of the control. In the later stages of drought conditions, the chlorophyll fluorescence parameter Fv/Fm was higher in leaves treated with 10 mM CaCl2 than in the leaves of the other two treatment groups. Zoysiagrass pretreated with 10 mM CaCl2 possessed both the maximum observed Pn and antioxidant enzyme activities. Meanwhile, lower MDA and proline contents were recorded in the plants pretreated with 5 and 10 mM CaCl2 under drought conditions. As a whole, the drought tolerance of zoysiagrass was improved to some extent by the application of a moderate calcium concentration.

  12. Activation and inhibition of TMEM16A calcium-activated chloride channels.

    PubMed

    Ni, Yu-Li; Kuan, Ai-Seon; Chen, Tsung-Yu

    2014-01-01

    Calcium-activated chloride channels (CaCC) encoded by family members of transmembrane proteins of unknown function 16 (TMEM16) have recently been intensely studied for functional properties as well as their physiological roles as chloride channels in various tissues. One technical hurdle in studying these channels is the well-known channel rundown that frequently impairs the precision of electrophysiological measurements for the channels. Using experimental protocols that employ fast-solution exchange, we circumvented the problem of channel rundown by normalizing the Ca(2+)-induced current to the maximally-activated current obtained within a time period in which the channel rundown was negligible. We characterized the activation of the TMEM16A-encoded CaCC (also called ANO1) by Ca(2+), Sr(2+), and Ba(2+), and discovered that Mg(2+) competes with Ca(2+) in binding to the divalent-cation binding site without activating the channel. We also studied the permeability of the ANO1 pore for various anions and found that the anion occupancy in the pore-as revealed by the permeability ratios of these anions-appeared to be inversely correlated with the apparent affinity of the ANO1 inhibition by niflumic acid (NFA). On the other hand, the NFA inhibition was neither affected by the degree of the channel activation nor influenced by the types of divalent cations used for the channel activation. These results suggest that the NFA inhibition of ANO1 is likely mediated by altering the pore function but not through changing the channel gating. Our study provides a precise characterization of ANO1 and documents factors that can affect divalent cation activation and NFA inhibition of ANO1.

  13. Multi-scale modelling of uranyl chloride solutions

    SciTech Connect

    Nguyen, Thanh-Nghi; Duvail, Magali Villard, Arnaud; Dufrêche, Jean-François; Molina, John Jairo; Guilbaud, Philippe

    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.

  14. Optimization of microwave-assisted calcium chloride pretreatment of corn stover.

    PubMed

    Li, Hongqiang; Xu, Jian

    2013-01-01

    A 62.5% (w/w) CaCl(2) solution was used in the microwave pretreatment of corn stover. The central composite design (CCD) of response surface methodology (RSM) was employed to design and optimize the CaCl(2)-assisted microwave pretreatment (CaCl(2)-pretreatment). Temperature and time were the main factors affecting the enzymatic digestibility of corn stover. After CaCl(2)-pretreatment, hemicellulose degradation reached 85.90%, the specific surface area (SSA) increased by 168.93%, cellulose crystallinity index (CrI) decreased by 13.91% compared to untreated corn stover. The optimal conditions for glucose production with the CaCl(2)-pretreatment obtained by CCD were, 162.1 °C, 12 min and solid-to-liquid ratio 10% (w/v). Under these conditions, the enzymatic hydrolysis ratio of cellulose was 90.66% and glucose recovery was 65.47%. This novel process achieved the temperature of about 160 °C necessary for lignocellulose pretreatment under atmospheric pressure using the cheap calcium chloride as the heating medium.

  15. The effect of calcium chloride concentration on alginate/Fmoc-diphenylalanine hydrogel networks.

    PubMed

    Çelik, Ekin; Bayram, Cem; Akçapınar, Rümeysa; Türk, Mustafa; Denkbaş, Emir Baki

    2016-09-01

    Peptide based hydrogels gained a vast interest in the tissue engineering studies thanks to great superiorities such as biocompatibility, supramolecular organization without any need of additional crosslinker, injectability and tunable nature. Fmoc-diphenylalanine (FmocFF) is one of the earliest and widely used example of these small molecule gelators that have been utilized in biomedical studies. However, Fmoc-peptides are not feasible for long term use due to low stability and weak mechanical properties at neutral pH. In this study, Fmoc-FF dipeptides were mechanically enhanced by incorporation of alginate, a biocompatible and absorbable polysaccharide. The binary hydrogel is obtained via molecular self-assembly of FmocFF dipeptide in alginate solution followed by ionic crosslinking of alginate moieties with varying concentrations of calcium chloride. Hydrogel characterization was evaluated in terms of morphology, viscoelastic moduli and diffusional phenomena and the structures were tested as 3D scaffolds for bovine chondrocytes. In vitro evaluation of scaffolds lasted up to 14days and cell viability, sulphated glycosaminoglycan (sGAG) levels, collagen type II synthesis were determined. Our results showed that alginate incorporation into FmocFF hydrogels leads to better mechanical properties and higher stability with good biocompatibility.

  16. The Electrochemical Reduction of Chromium Sesquioxide in Molten Calcium Chloride under Cathodic Potential Control

    NASA Astrophysics Data System (ADS)

    Schwandt, Carsten; Fray, Derek J.

    2007-11-01

    Electrochemical polarization and reduction experiments are reported which were performed with a three-terminal cell and a molten salt electrolyte consisting of calcium chloride with additions of calcium oxide. Employing a metal cathode, a graphite anode and a pseudo-reference electrode also made from graphite, polarization measurements were carried out with the aim to validate the performance of the pseudo-reference electrode and to assess the stability of the electrolyte. Using a chromium sesquioxide cathode in conjunction with a graphite anode and a graphite pseudo-reference electrode, electrochemical reduction experiments were conducted under potentiostatic control. The key results are: a graphite pseudo-reference electrode has been shown to be appropriate in the present type of molten salt electrochemical experiments that take place on a time scale of many hours; the conversion of chromium oxide into chromium metal has been accomplished under cathodic potential control and in the absence of calcium metal deposition; a significant amount of calcium oxide in the calcium chloride has been found necessary to preclude anodic chlorine formation throughout the entire experiment; a considerable overpotential has been identified at the anode.

  17. Anoctamin 1 induces calcium-activated chloride secretion and proliferation of renal cyst-forming epithelial cells.

    PubMed

    Buchholz, Bjoern; Faria, Diana; Schley, Gunnar; Schreiber, Rainer; Eckardt, Kai-Uwe; Kunzelmann, Karl

    2014-05-01

    Polycystic kidney diseases are characterized by multiple bilateral renal cysts that gradually enlarge and lead to a decline in renal function. Cyst enlargement is driven by transepithelial chloride secretion, stimulated by enhanced levels of cyclic adenosine monophosphate, which activates apical cystic fibrosis transmembrane conductance regulator chloride channels. However, chloride secretion by calcium-dependent chloride channels, activated through stimulation of purinergic receptors, also has a major impact. To identify the molecular basis of calcium-dependent chloride secretion in cyst expansion, we determined the role of anoctamin 1 and 6, two recently discovered calcium-activated chloride channels both of which are expressed in epithelial cells. We found that anoctamin 1, which plays a role in epithelial fluid secretion and proliferation, is strongly expressed in principal-like MDCK cells (PLCs) forming cysts within a collagen matrix, in an embryonic kidney cyst model, and in human autosomal dominant polycystic kidney disease tissue. Knockdown of anoctamin 1 but not anoctamin 6 strongly diminished the calcium-dependent chloride secretion of PLCs. Moreover, two inhibitors of anoctamin ion channels, tannic acid and a more selective inhibitor of anoctamin 1, significantly inhibited PLC cyst growth and cyst enlargement in an embryonic kidney cyst model. Knockdown of ANO1 by morpholino analogs also attenuated embryonic cyst growth. Thus, calcium-activated chloride secretion by anoctamin 1 appears to be a crucial component of renal cyst growth.

  18. Histological effects of calcium chloride in stored apples

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mature apples, Malus domestica Borkh., cv. 'Golden Delicious' were immersed for 2 min in 0, 0.14, 0.27, or 0.41 mol L-1 (0, 2%, 4%, or 6%, respectively) aqueous solutions (w/v) of CaCl2 at 0 or 68.95 Kpa, and stored at 0°C. Histological samples of peel/cortex were taken at harvest and at four month...

  19. The influence of magnesium chloride on blood and urine parameters in calcium oxalate stone patients.

    PubMed

    Brundig, P; Berg, W; Schneider, H J

    1981-01-01

    The influence of magnesium chloride on various blood and urine parameters in calcium oxalate stone patients is studied. High dose magnesium therapy was found to increase urinary magnesium concentrations, whereas the oxalic acid concentration is reduced. The experiments support the statements on the role of magnesium in endogenous oxalic acid depression and the inhibition of the intestinal resorption. For urolith prevention it will be necessary to apply high magnesium doses of easily absorbable and well-tolerated medicaments.

  20. A study of the effects of nickel chloride and calcium chloride on hydration of Portland cement

    SciTech Connect

    Akhter, H.; Cartledge, F.K.; Roy, A.; Tittlebaum, M.E. . Department of Chemistry and Institute for Recyclable Materials)

    1993-07-01

    Portland cement samples containing amounts of CaCl[sub 2] and NiCl[sub 2] ranging from approximately 1% to 20% by weight have been examined by [sup 29]Si and [sup 27]Al solid-state MAS NMR as a function of time, and some of the mature pastes have been characterized by X-ray diffraction. Changes in physical properties that had been previously observed as a function of amounts of salt added are clearly traceable to differences in the silicate matrices. Low concentrations of both salts promote Q[sup 1] formation, but high concentrations result in formation of much more Q[sup 2] at the expense of Q[sup 1]. Both salts accelerate both aluminate and silicate hydration, and the effects appear to be almost entirely due to chloride. Minor variations in hydration rates at high Ni concentrations may be the result of nickel salt precipitation.

  1. Conversion coatings prepared or treated with calcium hydroxide solutions

    NASA Technical Reports Server (NTRS)

    Minevski, Zoran (Inventor); Clarke, Eric (Inventor); Maxey, Jason (Inventor); Nelson, Carl (Inventor); Eylem, Cahit (Inventor)

    2002-01-01

    A conversion coating process that forms a stable and corrosion-resistant oxide layer on metal or metal oxide substrates or layers. Particularly, the conversion coating process involves contacting the metal or metal oxide substrate or layer with the aqueous calcium hydroxide solutions in order to convert the surface of the substrate to a stable metal oxide layer or coating. According to the present invention, the calcium hydroxide solution is prepared by removing carbon dioxide from water or an aqueous solution before introducing the calcium hydroxide. In this manner, formation of calcium carbonate particles is avoided and the porosity of the conversion coating produced by the calcium hydroxide solution is reduced to below about 1%.

  2. Calcium-activated chloride channels anoctamin 1 and 2 promote murine uterine smooth muscle contractility

    PubMed Central

    Bernstein, Kyra; Vink, Joy Y; Fu, Xiao Wen; Wakita, Hiromi; Danielsson, Jennifer; Wapner, Ronald; Gallos, George

    2014-01-01

    Objective To determine the presence of calcium activated chloride channels anoctamin 1 and 2 in human and murine uterine smooth muscle and evaluate the physiologic role for these ion channels in murine myometrial contractility. Study Design We performed reverse transcription polymerase chain reaction to determine if anoctamin 1 and 2 are expressed in human and murine uterine tissue to validate the study of this protein in mouse models. Immunohistochemical staining of anoctamin 1 and 2 was then performed to determine protein expression in murine myometrial tissue. The function of anoctamin 1 and 2 in murine uterine tissue was evaluated using electrophysiological studies, organ bath, and calcium flux experiments. Results Anoctamin 1 and 2 are expressed in human and murine USM cells. Functional studies show that selective antagonism of these channels promotes relaxation of spontaneous murine uterine smooth muscle contractions. Blockade of anoctamin 1 and 2 inhibits both agonist-induced and spontaneous transient inward currents and abolishes G-protein coupled receptor (oxytocin) mediated elevations in intracellular calcium. Conclusion The calcium activated chloride channels ANO 1 and 2 are present in human and murine myometrial tissue and may provide novel potential therapeutic targets to achieve effective tocolysis. PMID:24928056

  3. Preserved frontal lobe oxygenation following calcium chloride for treatment of anesthesia-induced hypotension.

    PubMed

    Kitchen, Carl-Christian; Nissen, Peter; Secher, Niels H; Nielsen, Henning B

    2014-01-01

    Vasopressor agents may affect cerebral oxygenation (rScO2) as determined by near-infrared spectroscopy on the forehead. This case series evaluated the effect of calcium chloride vs. α and β-adrenergic receptor agonists on rScO2 in patients (n = 47) undergoing surgery during i.v. anesthesia. Mean arterial pressure (MAP) and cardiac output (CO) were assessed by Model-flow(®) and ephedrine (55 ± 3 vs. 74 ± 9 mmHg; 10 mg, n = 9), phenylephrine (51 ± 5 vs. 78 ± 9 mmHg, 0.1 mg, n = 11), adrenaline (53 ± 3 vs. 72 ± 11 mmHg; 1-2 μg, n = 6), noradrenaline (53 ± 5 vs. 72 ± 12 mmHg; 2-4 μg, n = 11), and calcium chloride (49 ± 7 vs. 57 ± 16 mmHg; 5 mmol, n = 10) increased MAP (all P < 0.05). CO increased with ephedrine (4.3 ± 0.9 vs. 5.3 ± 1.2, P < 0.05) and adrenaline (4.7 ± 1.2 vs. 5.9 ± 1.1 l/min; P = 0.07) but was not significantly affected by phenylephrine (3.9 ± 0.7 vs. 3.6 ± 1.0 l/min), noradrenaline (3.8 ± 1.2 vs. 3.7 ± 0.7 l/min), or calcium chloride (4.0 ± 1.4 vs. 4.1 ± 1.5 l/min). Following administration of β-adrenergic agents and calcium chloride rScO2 was preserved while after administration of α-adrenergic drugs rScO2 was reduced by app. 2% (P < 0.05). Following α-adrenergic drugs to treat anesthesia-induced hypotension tissue oxygenation is reduced while the use of β-adrenergic agonists and calcium chloride preserve tissue oxygenation.

  4. Direct chemical reduction of neptunium oxide to neptunium metal using calcium and calcium chloride

    NASA Astrophysics Data System (ADS)

    Squires, Leah N.; Lessing, Paul

    2016-04-01

    A process of direct reduction of neptunium oxide to neptunium metal using calcium metal as the reducing agent is discussed. After reduction of the oxide to metal, the metal is separated by density from the other components of the reaction mixture and can be easily removed upon cooling. The direct reduction technique consistently produces high purity (98%-99% pure) neptunium metal.

  5. Anion permeation in calcium-activated chloride channels formed by TMEM16A from Xenopus tropicalis.

    PubMed

    Reyes, J P; López-Rodríguez, A; Espino-Saldaña, A E; Huanosta-Gutiérrez, A; Miledi, R; Martínez-Torres, A

    2014-09-01

    Calcium-activated chloride channels (CaCC) formed by anoctamin1/TMEM16A subunits are ubiquitously expressed, and these channels are known to prevent polyspermy in amphibian oocytes. Here, we describe a TMEM16A clone isolated from Xenopus tropicalis oocytes (xtTMEM16A) and how the anion permeation properties are modified in single-site mutants of the ion pore. The anion permeability sequence was SCN(-) > I(-) > Br(-) > Cl(-) > gluconate (relative permeabilities 5.6:3.0:2.1:1:0.2, respectively). Dose-response curves indicated that the voltage-dependent half-maximal concentration for Ca(2+) activation (K d of the Hill equation at +100 mV) was 120 nM in normal external Cl(-), whereas it was displaced leftward to 75 nM Ca(2+), when I(-) replaced Cl(-). The I(-):Cl(-) mole fraction (MF) of the external solution was varied in order to gain insight into the permeation mechanism of the pore. No anomaly in MF behavior was observed for conductance, but it was observed for current reversal potential, which deviated from the prediction of the Goldman-Hodgkin-Katz equation. Mutations of positively charged amino acids in the pore, R646 and R761, to glutamate resulted in reduction of the relative permeability to I(-). Data from the wild type and mutants could be well fitted by a three-barrier, two-site permeation model. This suggests a multi-ion pore with at least two binding sites for anions, with R646 mole fraction closer to the extracellular membrane surface--being important for the stability of both sites--and R761--located deeper within the membrane--mainly affecting the innermost binding site. Considerations of xtTMEM16A putative pore region topology are discussed in the light of two alternative topological models of the protein. PMID:24352628

  6. Corrosion Effects of Calcium Chloride Injection for Mercury Control on the Pollution Control Equipment

    SciTech Connect

    Vijay Sethi; M.P. Sharma

    2009-02-28

    In response to the Clean Air Mercury Rule (CAMR) of 2005, Black Hills Power (BHP) initiated testing of a calcium chloride (CaCl{sub 2}) injection method in their Wygen 1 (Gillette, WY) coal-fired power plant to help lower mercury emissions. In 2006, Babcock & Wilcox (B&W) was contracted to test their CaCl{sub 2} technology in-situ by adding a CaCl{sub 2} solution onto the raw, pre-pulverized coal during normal operation of Wygen 1. Follow-up tests were conducted by BHP in 2007. Data were collected from these two time periods and analyzed by a collaborative investigation team from Western Research Institute (WRI) and the University of Wyoming (UW) to see if there were any effects on the current air pollution control systems. During a CaCl{sub 2} injection period in 2007, corrosion was monitored in the flue and recycle ash system by placing corrosion coupons in strategic locations to test if corrosion was enhanced by the CaCl{sub 2} injection. While the CaCl{sub 2} produced a reduction in stack mercury levels, there was some evidence of beneficial impacts on the removal of SO{sub 2} from the flue gas during CaCl{sub 2} injection. Data on NOx remained inconclusive. It was also discovered that corrosion was enhanced significantly in the Spray Drier Absorber (SDA) vessel and corresponding outlet ductwork during CaCl{sub 2} injections. Further studies are being carried out in the field and lab to better understand the corrosive effects of CaCl{sub 2} to help formulate operation controls to manage the increased corrosion rates.

  7. Modeling of solute sorption by polyvinyl chloride plastic infusion bags.

    PubMed

    Jenke, D R

    1993-11-01

    Methods for estimating the equilibrium and time-dependent sorption of solutes by polymeric containers have been developed. The methods are specifically applied to the sorption of solutes by polyvinyl chloride (PVC) infusion bags. The methods correlate the partition coefficients and dissociation constant (when appropriate) of the solute, the physical dimensions of the container, and solution pH with single parameters that dictate the shape of the sorption profile. To determine the equilibrium sorption level for PVC containers, the fractional binding of a solute is correlated with its hexane-water and octanol-water partition coefficients. Calculations based on single partition coefficients are less effective in terms of mimicking the behavior of the PVC. To determine the sorption profile (fractional binding versus time), the partition coefficients are related to the fraction binding at a particular time through a single parameter referred to as the sorption number. Equilibrium fractional binding and sorption profiles for various drugs stored in PVC containers are generated with the models and agree well with reported behavior. The effect of pH on the sorption process is also examined.

  8. Calcium chloride effects on the glass transition of condensed systems of potato starch.

    PubMed

    Chuang, Lillian; Panyoyai, Naksit; Katopo, Lita; Shanks, Robert; Kasapis, Stefan

    2016-05-15

    The effect of calcium chloride on the structural properties of condensed potato starch undergoing a thermally induced glass transition has been studied using dynamic mechanical analysis and modulated differential scanning calorimetry. Extensive starch gelatinisation was obtained by hot pressing at 120°C for 7 min producing materials that covered a range of moisture contents from 3.7% w/w (11% relative humidity) to 18.8% w/w (75% relative humidity). FTIR, ESEM and WAXD were also performed in order to elucidate the manner by which salt addition affects the molecular interactions and morphology of condensed starch. Experimental protocol ensured the development of amorphous matrices that exhibited thermally reversible glassy consistency. Both moisture content and addition of calcium chloride affected the mechanical strength and glass transition temperature of polymeric systems. Highly reactive calcium ions form a direct interaction with starch to alter considerably its structural properties via an anti-plasticizing effect, as compared to the polymer-water matrix. PMID:26776036

  9. Calcium chloride effects on the glass transition of condensed systems of potato starch.

    PubMed

    Chuang, Lillian; Panyoyai, Naksit; Katopo, Lita; Shanks, Robert; Kasapis, Stefan

    2016-05-15

    The effect of calcium chloride on the structural properties of condensed potato starch undergoing a thermally induced glass transition has been studied using dynamic mechanical analysis and modulated differential scanning calorimetry. Extensive starch gelatinisation was obtained by hot pressing at 120°C for 7 min producing materials that covered a range of moisture contents from 3.7% w/w (11% relative humidity) to 18.8% w/w (75% relative humidity). FTIR, ESEM and WAXD were also performed in order to elucidate the manner by which salt addition affects the molecular interactions and morphology of condensed starch. Experimental protocol ensured the development of amorphous matrices that exhibited thermally reversible glassy consistency. Both moisture content and addition of calcium chloride affected the mechanical strength and glass transition temperature of polymeric systems. Highly reactive calcium ions form a direct interaction with starch to alter considerably its structural properties via an anti-plasticizing effect, as compared to the polymer-water matrix.

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

    PubMed

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

    2016-01-01

    Ceftriaxone sodium preparation for injection is known to form insoluble microparticles with calcium. The purpose of this study was to evaluate the role of an impurity in the ceftriaxone sodium preparation on this incompatibility. Firstly, using HPLC, two impurities were identified in the ceftriaxone sodium solution. The major impurity (impurity 1) was identified as tetrahydro-2-methyl-3-thioxo-1,2,4-triazine-5,6-dione by LC/MS. Secondly, the role played by this impurity in the incompatibility with calcium was examined. Using seven different ceftriaxone preparations for injection, the effect of adding impurity 1 to mixed solutions of ceftriaxone sodium and calcium chloride on the appearance of insoluble microparticles, was examined using a light obscuration particle counter. Although incompatibility was not completely suppressed by the addition of impurity 1, the number of insoluble microparticles formed with calcium chloride solution was decreased in proportion to the concentration of impurity 1, and the concentration of calcium ion decreased as the concentration of added impurity 1 increased. These results show that impurity 1 plays a concentration-dependent role in incompatibility between ceftriaxone sodium preparation for injection and calcium-containing solutions. PMID:26936047

  11. Chlorotoxin does not inhibit volume-regulated, calcium-activated and cyclic AMP-activated chloride channels.

    PubMed

    Maertens, C; Wei, L; Tytgat, J; Droogmans, G; Nilius, B

    2000-02-01

    It was the aim of this study to look for a high-affinity and selective polypeptide toxin, which could serve as a probe for the volume-regulated anion channel (VRAC) or the calcium-activated chloride channel (CaCC). We have partially purified chlorotoxin, including new and homologous short chain insectotoxins, from the crude venom of Leiurus quinquestriatus quinquestriatus (Lqq) by means of gel filtration chromatography. Material eluting between 280 and 420 min, corresponding to fractions 15-21, was lyophilized and tested on VRAC and CaCC, using the whole-cell patch-clamp technique. We have also tested the commercially available chlorotoxin on VRAC, CaCC, the cystic fibrosis transmembrane conductance regulator (CFTR) and on the glioma specific chloride channel (GCC). VRAC and the correspondent current, I(Cl,swell), was activated in Cultured Pulmonary Artery Endothelial (CPAE) cells by a 25% hypotonic solution. Neither of the fractions 16-21 significantly inhibited I(Cl,swell) (n=4-5). Ca(2+)-activated Cl(-) currents, I(Cl,Ca), activated by loading T84 cells via the patch pipette with 1 microM free Ca(2+), were not inhibited by any of the tested fractions (15-21), (n=2-5). Chlorotoxin (625 nM) did neither effect I(Cl,swell) nor I(Cl,Ca) (n=4-5). The CFTR channel, transiently transfected in COS cells and activated by a cocktail containing IBMX and forskolin, was not affected by 1.2 microM chlorotoxin (n=5). In addition, it did not affect currents through GCC. We conclude that submicromolar concentrations of chlorotoxin do not block volume-regulated, Ca(2+)-activated and CFTR chloride channels and that it can not be classified as a general chloride channel toxin.

  12. 43 CFR 3511.11 - If I am mining calcium chloride, may I obtain a noncompetitive mineral lease to produce the...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... obtain a noncompetitive mineral lease to produce the commingled sodium chloride? 3511.11 Section 3511.11... mineral lease to produce the commingled sodium chloride? Yes. If you are producing calcium chloride in... lease to produce the commingled sodium chloride. You must already have authorization, under part 3800...

  13. 43 CFR 3511.11 - If I am mining calcium chloride, may I obtain a noncompetitive mineral lease to produce the...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... obtain a noncompetitive mineral lease to produce the commingled sodium chloride? 3511.11 Section 3511.11... mineral lease to produce the commingled sodium chloride? Yes. If you are producing calcium chloride in... lease to produce the commingled sodium chloride. You must already have authorization, under part 3800...

  14. 43 CFR 3511.11 - If I am mining calcium chloride, may I obtain a noncompetitive mineral lease to produce the...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... obtain a noncompetitive mineral lease to produce the commingled sodium chloride? 3511.11 Section 3511.11... mineral lease to produce the commingled sodium chloride? Yes. If you are producing calcium chloride in... lease to produce the commingled sodium chloride. You must already have authorization, under part 3800...

  15. 43 CFR 3511.11 - If I am mining calcium chloride, may I obtain a noncompetitive mineral lease to produce the...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... obtain a noncompetitive mineral lease to produce the commingled sodium chloride? 3511.11 Section 3511.11... mineral lease to produce the commingled sodium chloride? Yes. If you are producing calcium chloride in... lease to produce the commingled sodium chloride. You must already have authorization, under part 3800...

  16. Localized corrosion of candidate container materials in ferric chloride solutions

    SciTech Connect

    Fleming, D L; Lum, B Y; Roy, A K

    1998-10-01

    Localized corrosion behavior of candidate inner and outer container materials of currently-designed nuclear waste package was evaluated in aqueous solutions of various concentrations of ferric chloride (FeCl{sub 3}) at 30 C, 60 C and 90 C using the electrochemical cyclic potentiodynamic polarization (CPP) technique. Materials tested include A 5 16 carbon steel and high-performance alloys 825, G-3, G-30, C-4, 625. C-22, and Ti Gr-12. A 516 steel suffered from severe general and localized attack including pitting and crevice corrosion. High-nickel alloys 825 and G-3 also became susceptible to severe pitting and crevice corrosion. The extent of localized attack was less pronounced in alloys G-30 and C-4. Alloy 625 experienced severe surface degradation including general corrosion, crevice corrosion and intergranular attack. In contrast, only a slight crevice corrosion tendency was observed with nickel-base alloy C-22 in solutions containing higher concentrations of FeCl{sub 3} at 60 C and 90 C. Ti Gr-12 was immune to localized attack in all tested environments. The test solutions showed significant amount of precipitated particles during and after testing especially at higher temperatures.

  17. An in situ crosslinked compression coat comprised of pectin and calcium chloride for colon-specific delivery of indomethacin.

    PubMed

    Wei, Xiuli; Lu, Yi; Qi, Jianping; Wu, Baojian; Chen, Jian; Xu, Huinan; Wu, Wei

    2015-05-01

    The use of pectin for colon-specific drug delivery has been extensively investigated; however, when used alone, pectin is often compromised due to its high solubility. This study explored the feasibility of using an in situ compression-coated crosslinking system, composed of pectin and calcium chloride, for colon-specific drug delivery. A pectin/calcium chloride (P/Ca) coating was compressed onto a core tablet. The colon specificity of the compression-coated tablet was verified by dissolution, pharmacokinetics and scintigraphy with (99m)Tc labeling. The in situ pectin and calcium chloride gel slowed the release of indomethacin. The lag time varied between 3 h and 7 h depending on the amount of calcium chloride and the coating weight. Pectinase triggered the release of indomethacin from the compression-coated tablet, which was then accelerated by the calcium chloride in the coating layer. The compression-coated tablet had a prolonged tmax and apparent t1/2, as well as a decreased Cmax and AUC0-t, compared with the core tablet counterpart. Evaluation with γ-scintigraphy verified colon-specific delivery of the compression-coated tablet. In conclusion, the P/Ca in situ crosslinking system worked well for colon-specific drug delivery.

  18. Modulation of intracellular calcium homeostasis by trimethyltin chloride in human tumour cells: neuroblastoma SY5Y and cervix adenocarcinoma HeLa S3.

    PubMed

    Florea, Ana-Maria; Splettstoesser, Frank; Dopp, Elke; Rettenmeier, Albert W; Büsselberg, Dietrich

    2005-12-01

    Physiological modifications of intracellular Ca2+ ([Ca2+]i) levels trigger and/or regulate a diversity of cellular activities (e.g. neurotransmitter release, synaptic plasticity, muscular contraction, cell proliferation), while calcium overloads could result in cytotoxicity. Previously, we have shown that trimethyltin chloride (Me3SnCl; TMT) modulates calcium homeostasis in cervix adenocarcinoma (HeLa S3) cells [Florea, A.-M., Dopp, E., Büsselberg, D., 2005. TMT induces elevated calcium transients in HeLa cells: types and levels of response. Cell Calcium 37, 252-258]. Here we compare [Ca2+]i-changes induced by trimethyltin chloride in neuroblastoma SY5Y and HeLa S3 cells using calcium-sensitive dyes (fluo-4/AM (fluo-4) and rhod-2/AM (rhod-2)) and laser scanning microscopy (LSM). TMT-induced calcium elevations in neuroblastoma SY5Y as well as in HeLa S3 cells. [Ca2+]i rose to a sustained plateau or to transient spikes. Overall, the detected averaged increase of the maximum calcium elevation were: 0.5 microM approximately 125.6%; 5 microM approximately 130.1%; 500 microM approximately 145% in HeLa S3 cells and 0.5 microM approximately 133.3%; 5 microM approximately 136.1%; 500 microM approximately 147.1% in neuroblastoma SY5Y cells. The calcium rise derived from internal stores did not significantly depend on the presence of calcium in the external solution: approximately 109% (no calcium added) versus approximately 117% (2 mM calcium; 5 microM TMT) in HeLa cells. This difference was similar in neuroblastoma SY5Y cells, were approximately 127% versus approximately 136% increase (5 microM TMT) were measured. Staining of calcium stores with rhod-2 showed a TMT-induced [Ca2+]i-decrease in the stores followed by an increase of the calcium concentration in the nuclei of the two cell lines tested. Our results suggest that toxic effects in human tumour cells after exposure to trimethyltin compounds might be due to an elevation of [Ca2+]i.

  19. Annexin A4 induces platinum resistance in a chloride-and calcium-dependent manner.

    PubMed

    Morimoto, Akiko; Serada, Satoshi; Enomoto, Takayuki; Kim, Ayako; Matsuzaki, Shinya; Takahashi, Tsuyoshi; Ueda, Yutaka; Yoshino, Kiyoshi; Fujita, Masami; Fujimoto, Minoru; Kimura, Tadashi; Naka, Tetsuji

    2014-09-15

    Platinum resistance has long been a major issue in the treatment of various cancers. We previously reported that enhanced annexin A4 (ANXA4) expression, a Ca2+-regulated phospholipid-binding protein, induces chemoresistance to platinum-based drugs. In this study, we investigated the role of annexin repeats, a conserved structure of all the annexin family, responsible for platinum-resistance as well as the effect of knockdown of ANXA4. ANXA4 knockdown increased sensitivity to platinum-based drugs both in vitro and in vivo. To identify the domain responsible for chemoresistance, ANXA4 deletion mutants were constructed by deleting annexin repeats one by one from the C terminus. Platinum resistance was induced both in vitro and in vivo in cells expressing either full-length ANXA4 or the deletion mutants, containing at least one intact annexin repeat. However, cells expressing the mutant without any calcium-binding sites in the annexin repeated sequence, which is essential for ANXA4 translocation from the cytosol to plasma membrane, failed to acquire platinum resistance. After cisplatin treatment, the intracellular chloride ion concentration, whose channel is partly regulated by ANXA4, significantly increased in the platinum-resistant cells. These findings indicate that the calcium-binding site in the annexin repeat induces chemoresistance to the platinum-based drug by elevating the intracellular chloride concentration.

  20. Biocompatibility of Portland Cement Modified with Titanium Oxide and Calcium Chloride in a Rat Model

    PubMed Central

    Hoshyari, Narjes; Labbaf, Hossein; Jalayer Naderi, Nooshin; Kazemi, Ali; Bastami, Farshid; Koopaei, Maryam

    2016-01-01

    Introduction: The aim of the present study was to evaluate the biocompatibility of two modified formulations of Portland cement (PC) mixed with either titanium oxide or both titanium oxide and calcium chloride. Methods and Materials: Polyethylene tubes were filled with modified PCs or Angelus MTA as the control; the tubes were then implanted in 28 Wistar rats subcutaneously. One tube was left empty as a negative control in each rat. Histologic samples were taken after 7, 15, 30 and 60 days. Sections were assessed histologically for inflammatory responses and presence of fibrous capsule and granulation tissue formation. Data were analyzed using the Fisher’s exact and Kruskal-Wallis tests. Result: PC mixed with titanium oxide showed the highest mean scores of inflammation compared with others. There was no statistically significant difference in the mean inflammatory grades between all groups in each of the understudy time intervals. Conclusion: The results showed favorable biocompatibility of these modified PC mixed with calcium chloride and titanium oxide. PMID:27141221

  1. Anoctamins support calcium-dependent chloride secretion by facilitating calcium signaling in adult mouse intestine.

    PubMed

    Schreiber, Rainer; Faria, Diana; Skryabin, Boris V; Wanitchakool, Podchanart; Rock, Jason R; Kunzelmann, Karl

    2015-06-01

    Intestinal epithelial electrolyte secretion is activated by increase in intracellular cAMP or Ca(2+) and opening of apical Cl(-) channels. In infants and young animals, but not in adults, Ca(2+)-activated chloride channels may cause secretory diarrhea during rotavirus infection. While detailed knowledge exists concerning the contribution of cAMP-activated cystic fibrosis transmembrane conductance regulator (CFTR) channels, analysis of the role of Ca(2+)-dependent Cl(-) channels became possible through identification of the anoctamin (TMEM16) family of proteins. We demonstrate expression of several anoctamin paralogues in mouse small and large intestines. Using intestinal-specific mouse knockout models for anoctamin 1 (Ano1) and anoctamin 10 (Ano10) and a conventional knockout model for anoctamin 6 (Ano6), we demonstrate the role of anoctamins for Ca(2+)-dependent Cl(-) secretion induced by the muscarinic agonist carbachol (CCH). Ano1 is preferentially expressed in the ileum and large intestine, where it supports Ca(2+)-activated Cl(-) secretion. In contrast, Ano10 is essential for Ca(2+)-dependent Cl(-) secretion in jejunum, where expression of Ano1 was not detected. Although broadly expressed, Ano6 has no role in intestinal cholinergic Cl(-) secretion. Ano1 is located in a basolateral compartment/membrane rather than in the apical membrane, where it supports CCH-induced Ca(2+) increase, while the essential and possibly only apical Cl(-) channel is CFTR. These results define a new role of Ano1 for intestinal Ca(2+)-dependent Cl(-) secretion and demonstrate for the first time a contribution of Ano10 to intestinal transport.

  2. Shikonin Inhibits Intestinal Calcium-Activated Chloride Channels and Prevents Rotaviral Diarrhea.

    PubMed

    Jiang, Yu; Yu, Bo; Yang, Hong; Ma, Tonghui

    2016-01-01

    Secretory diarrhea remains a global health burden and causes major mortality in children. There have been some focuses on antidiarrheal therapies that may reduce fluid losses and intestinal motility in diarrheal diseases. In the present study, we identified shikonin as an inhibitor of TMEM16A chloride channel activity using cell-based fluorescent-quenching assay. The IC50 value of shikonin was 6.5 μM. Short-circuit current measurements demonstrated that shikonin inhibited Eact-induced Cl(-) current in a dose-dependent manner, with IC50 value of 1.5 μM. Short-circuit current measurement showed that shikonin exhibited inhibitory effect against CCh-induced Cl(-) currents in mouse colonic epithelia but did not affect cytoplasmic Ca(2+) concentration as well as the other major enterocyte chloride channel conductance regulator. Characterization study found that shikonin inhibited basolateral K(+) channel activity without affecting Na(+)/K(+)-ATPase activities. In vivo studies revealed that shikonin significantly delayed intestinal motility in mice and reduced stool water content in a neonatal mice model of rotaviral diarrhea without affecting the viral infection process in vivo. Taken together, the results suggested that shikonin inhibited enterocyte calcium-activated chloride channels, the inhibitory effect was partially through inhbition of basolateral K(+) channel activity, and shikonin could be a lead compound in the treatment of rotaviral secretory diarrhea.

  3. Shikonin Inhibits Intestinal Calcium-Activated Chloride Channels and Prevents Rotaviral Diarrhea

    PubMed Central

    Jiang, Yu; Yu, Bo; Yang, Hong; Ma, Tonghui

    2016-01-01

    Secretory diarrhea remains a global health burden and causes major mortality in children. There have been some focuses on antidiarrheal therapies that may reduce fluid losses and intestinal motility in diarrheal diseases. In the present study, we identified shikonin as an inhibitor of TMEM16A chloride channel activity using cell-based fluorescent-quenching assay. The IC50 value of shikonin was 6.5 μM. Short-circuit current measurements demonstrated that shikonin inhibited Eact-induced Cl- current in a dose-dependent manner, with IC50 value of 1.5 μM. Short-circuit current measurement showed that shikonin exhibited inhibitory effect against CCh-induced Cl- currents in mouse colonic epithelia but did not affect cytoplasmic Ca2+ concentration as well as the other major enterocyte chloride channel conductance regulator. Characterization study found that shikonin inhibited basolateral K+ channel activity without affecting Na+/K+-ATPase activities. In vivo studies revealed that shikonin significantly delayed intestinal motility in mice and reduced stool water content in a neonatal mice model of rotaviral diarrhea without affecting the viral infection process in vivo. Taken together, the results suggested that shikonin inhibited enterocyte calcium-activated chloride channels, the inhibitory effect was partially through inhbition of basolateral K+ channel activity, and shikonin could be a lead compound in the treatment of rotaviral secretory diarrhea. PMID:27601995

  4. Shikonin Inhibits Intestinal Calcium-Activated Chloride Channels and Prevents Rotaviral Diarrhea.

    PubMed

    Jiang, Yu; Yu, Bo; Yang, Hong; Ma, Tonghui

    2016-01-01

    Secretory diarrhea remains a global health burden and causes major mortality in children. There have been some focuses on antidiarrheal therapies that may reduce fluid losses and intestinal motility in diarrheal diseases. In the present study, we identified shikonin as an inhibitor of TMEM16A chloride channel activity using cell-based fluorescent-quenching assay. The IC50 value of shikonin was 6.5 μM. Short-circuit current measurements demonstrated that shikonin inhibited Eact-induced Cl(-) current in a dose-dependent manner, with IC50 value of 1.5 μM. Short-circuit current measurement showed that shikonin exhibited inhibitory effect against CCh-induced Cl(-) currents in mouse colonic epithelia but did not affect cytoplasmic Ca(2+) concentration as well as the other major enterocyte chloride channel conductance regulator. Characterization study found that shikonin inhibited basolateral K(+) channel activity without affecting Na(+)/K(+)-ATPase activities. In vivo studies revealed that shikonin significantly delayed intestinal motility in mice and reduced stool water content in a neonatal mice model of rotaviral diarrhea without affecting the viral infection process in vivo. Taken together, the results suggested that shikonin inhibited enterocyte calcium-activated chloride channels, the inhibitory effect was partially through inhbition of basolateral K(+) channel activity, and shikonin could be a lead compound in the treatment of rotaviral secretory diarrhea. PMID:27601995

  5. Shikonin Inhibits Intestinal Calcium-Activated Chloride Channels and Prevents Rotaviral Diarrhea

    PubMed Central

    Jiang, Yu; Yu, Bo; Yang, Hong; Ma, Tonghui

    2016-01-01

    Secretory diarrhea remains a global health burden and causes major mortality in children. There have been some focuses on antidiarrheal therapies that may reduce fluid losses and intestinal motility in diarrheal diseases. In the present study, we identified shikonin as an inhibitor of TMEM16A chloride channel activity using cell-based fluorescent-quenching assay. The IC50 value of shikonin was 6.5 μM. Short-circuit current measurements demonstrated that shikonin inhibited Eact-induced Cl- current in a dose-dependent manner, with IC50 value of 1.5 μM. Short-circuit current measurement showed that shikonin exhibited inhibitory effect against CCh-induced Cl- currents in mouse colonic epithelia but did not affect cytoplasmic Ca2+ concentration as well as the other major enterocyte chloride channel conductance regulator. Characterization study found that shikonin inhibited basolateral K+ channel activity without affecting Na+/K+-ATPase activities. In vivo studies revealed that shikonin significantly delayed intestinal motility in mice and reduced stool water content in a neonatal mice model of rotaviral diarrhea without affecting the viral infection process in vivo. Taken together, the results suggested that shikonin inhibited enterocyte calcium-activated chloride channels, the inhibitory effect was partially through inhbition of basolateral K+ channel activity, and shikonin could be a lead compound in the treatment of rotaviral secretory diarrhea.

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

    PubMed Central

    Ha, Hung; Payer, Joe

    2011-01-01

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

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

    PubMed

    Ha, Hung; Payer, Joe

    2011-02-28

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

  8. Protective effect of a calcium channel blocker "diltiazem" on aluminum chloride-induced dementia in mice.

    PubMed

    Rani, Anu; Neha; Sodhi, Rupinder K; Kaur, Amanpreet

    2015-11-01

    Many studies report that heavy metals such as aluminum are involved in amyloid beta aggregation and neurotoxicity. Further, high concentration of aluminum in the brain deregulates calcium signaling which contributes to synaptic dysfunction and halts neuronal communication which ultimately leads to the development of Alzheimer's disease. Recently, diltiazem, a calcium channel blocker clinically used in angina, is reported to decrease amyloid beta production by inhibiting calcium influx, decreasing inflammation and oxidative stress. However, the probable role of this drug in aluminum chloride (AlCl3)-induced experimental dementia is yet to be explored. Therefore, the present study is designed to investigate the effect of AlCl3-induced dementia in mice. Morris water maze test and elevated plus maze were utilized to evaluate learning and memory. Various biochemical estimations including brain acetylcholinesterase activity (AChE), brain total protein, thiobarbituric acid-reactive species (TBARS) level, reduced glutathione (GSH) level, nitrate/nitrite, and superoxide dismutase (SOD) were measured. AlCl3 significantly impaired learning and memory and increased brain AChE, brain total protein, TBARS, and nitrate/nitrite and decreased brain GSH or SOD. On the other hand, treatment with diltiazem significantly reversed AlCl3-induced behavioral and biochemical deficits. The present study indicates the beneficial role of diltiazem in AlCl3-induced dementia.

  9. Location of Release Sites and Calcium-Activated Chloride Channels Relative to Calcium Channels at the Photoreceptor Ribbon Synapse

    PubMed Central

    Mercer, A. J.; Rabl, K.; Riccardi, G. E.; Brecha, N. C.; Stella, S. L.

    2011-01-01

    Vesicle release from photoreceptor ribbon synapses is regulated by L-type Ca2+ channels, which are in turn regulated by Cl− moving through calcium-activated chloride [Cl(Ca)] channels. We assessed the proximity of Ca2+ channels to release sites and Cl(Ca) channels in synaptic terminals of salamander photoreceptors by comparing fast (BAPTA) and slow (EGTA) intracellular Ca2+ buffers. BAPTA did not fully block synaptic release, indicating some release sites are <100 nm from Ca2+ channels. Comparing Cl(Ca) currents with predicted Ca2+ diffusion profiles suggested that Cl(Ca) and Ca2+ channels average a few hundred nanometers apart, but the inability of BAPTA to block Cl(Ca) currents completely suggested some channels are much closer together. Diffuse immunolabeling of terminals with an antibody to the putative Cl(Ca) channel TMEM16A supports the idea that Cl(Ca) channels are dispersed throughout the presynaptic terminal, in contrast with clustering of Ca2+ channels near ribbons. Cl(Ca) currents evoked by intracellular calcium ion concentration ([Ca2+]i) elevation through flash photolysis of DM-nitrophen exhibited EC50 values of 556 and 377 nM with Hill slopes of 1.8 and 2.4 in rods and cones, respectively. These relationships were used to estimate average submembrane [Ca2+]i in photoreceptor terminals. Consistent with control of exocytosis by [Ca2+] nanodomains near Ca2+ channels, average submembrane [Ca2+]i remained below the vesicle release threshold (∼400 nM) over much of the physiological voltage range for cones. Positioning Ca2+ channels near release sites may improve fidelity in converting voltage changes to synaptic release. A diffuse distribution of Cl(Ca) channels may allow Ca2+ influx at one site to influence relatively distant Ca2+ channels. PMID:21084687

  10. Calcium chloride electron injection/extraction layers in organic electronic devices

    SciTech Connect

    Qu, Bo E-mail: qhgong@pku.edu.cn; Gao, Zhi; Yang, Hongsheng; Xiao, Lixin; Chen, Zhijian; Gong, Qihuang E-mail: qhgong@pku.edu.cn

    2014-01-27

    Nontoxic calcium chloride (CaCl{sub 2}) was introduced into organic electronic devices as cathode buffer layer (CBL). The turn-on voltage and maximum luminance of organic light-emitting diode (OLED) with 1.5 nm CaCl{sub 2} was 3.5 V and 21 960 cd/m{sup 2}, respectively. OLED with 1.5 nm CaCl{sub 2} possessed comparable electroluminescent characteristics to that of the commonly used LiF. Moreover, the performance of the organic photovoltaic device with 0.5 nm CaCl{sub 2} was comparable to that of the control device with LiF. Therefore, CaCl{sub 2} has the potential to be used as the CBL for organic electronic devices.

  11. Calcium chloride electron injection/extraction layers in organic electronic devices

    NASA Astrophysics Data System (ADS)

    Qu, Bo; Gao, Zhi; Yang, Hongsheng; Xiao, Lixin; Chen, Zhijian; Gong, Qihuang

    2014-01-01

    Nontoxic calcium chloride (CaCl2) was introduced into organic electronic devices as cathode buffer layer (CBL). The turn-on voltage and maximum luminance of organic light-emitting diode (OLED) with 1.5 nm CaCl2 was 3.5 V and 21 960 cd/m2, respectively. OLED with 1.5 nm CaCl2 possessed comparable electroluminescent characteristics to that of the commonly used LiF. Moreover, the performance of the organic photovoltaic device with 0.5 nm CaCl2 was comparable to that of the control device with LiF. Therefore, CaCl2 has the potential to be used as the CBL for organic electronic devices.

  12. Human osteoblast cytotoxicity study of electrospun polyurethane/calcium chloride ultrafine nanofibers.

    PubMed

    Nirmala, R; Kang, Hyung-Sub; El-Newehy, Mohamed H; Navamathavan, R; Park, Hye-Min; Kim, Hak Yong

    2011-06-01

    This work was focused on preparation and characterization of the polyurethane nanofibers containing calcium chloride (CaCl2) prepared via electrospinning process for the bionanotechnological applications. The morphological, structural characterizations and thermal properties of the polyurethane/CaCl2 nanofibers were determined by using scanning electron microscopy (SEM), field-emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDX), Fourier transform-infrared (FT-IR) spectroscopy and thermogravimetry (TGA). SEM images revealed that these composite nanofibers were well-oriented and had good incorporation of CaCl2. The morphological feature of the cells attached on polyurethane/CaCl2 nanofibers scaffold was confirmed by SEM. The in vitro cell compatibility of the polyurethane/CaCl2 composite nanofibers was studied. This study demonstrated the non-toxic effect of electrospun polyurethane/CaCl2 composite nanofibers. Based on this, we propose a mechanism for the cell attachment.

  13. Effect of calcium chloride on the isobaric vapor-liquid equilibrium of 1-propanol + water

    SciTech Connect

    Iliuta, M.C.; Thyrion, F.C.; Landauer, O.M.

    1996-05-01

    The effect of calcium chloride at salt mole fractions from 0.02 to saturation on the vapor-liquid equilibrium (VLE) of 1-propanol + water has been studied at 101.32 kPa using a modified Othmer equilibrium still. The salt exhibited a salting-out effect of the alcohol over the whole range of liquid composition, the azeotrope being eliminated at salt mole fractions greater than 0.080. A liquid phase splitting into two immiscible liquid phases on the whole range of salt concentration and over a liquid range of about 0.01--0.54 1-propanol mole fraction (salt-free basis) was observed. The results were compared with the values predicted from the extended UNIQUAC models of Sander et al. and Macedo et al. and the modified UNIFAC group-contribution model of Kikic et al.

  14. Corrosion behavior of silicon nitride, magnesium oxide, and several metals in molten calcium chloride with chlorine

    SciTech Connect

    McLaughlin, D. . Research and Development Center); Sesions, C.E.; Marra, J.E. )

    1992-08-01

    In this paper corrosion studies are described in a molten calcium chloride environment sparged with chlorine gas at 850{degrees}C, both in the melt and in the gas phase above the salt, in support of efforts at Westinghouse Savannah River Company to develop more resistant materials of construction for molten salt processing of plutonium. Corrosion rates and electron microscope analyses are reported for Inconel alloys 601 and 617, tantalum, tungsten, magnesium oxide, and silicon nitride. Silicon nitride exhibited the greatest resistance, showing {lt}0.1 mg/cm{sup 2} {center dot} h loss in both melt and vapor None of the metallic coupons withstood the chlorine vapor environment, although Inconel indicated resistance immersed in the melt if protected from chlorine gas.

  15. Physico-chemical and sensory properties of reduced-fat mortadella prepared with blends of calcium, magnesium and potassium chloride as partial substitutes for sodium chloride.

    PubMed

    Horita, C N; Morgano, M A; Celeghini, R M S; Pollonio, M A R

    2011-12-01

    Blends of calcium, magnesium and potassium chloride were used to partially replace sodium chloride (50-75%) in reduced-fat mortadella formulations. The presence of calcium chloride reduced the emulsion stability, cooking yield, elasticity and cohesiveness and increased hardness; however, it yielded the best sensory acceptance when 50% NaCl was replaced by 25% CaCl(2) and 25% KCl. There was no effect of the salt substitutes on mortadella color, appearance and aroma. All salt combinations studied showed stable lipid oxidation during its shelf life. The use of a blend with 1% NaCl, 0.5% KCl and 0.5% MgCl(2) resulted in the best emulsion stability, but the worst scores for flavor. This study suggests that it is possible to reduce the sodium chloride concentration by 50% in reduced-fat mortadella using the studied salt combinations with necessary adjustments to optimize the sensory properties (MgCl(2) 25%; KCl 25%) or emulsion stability (CaCl(2) 25%; KCl 25%).

  16. A possible role of Aspergillus niger mitochondrial cytochrome c in malachite green reduction under calcium chloride stress.

    PubMed

    Gomaa, Ola M; Selim, Nabila S; Linz, John E

    2013-01-01

    In previous work, decolorization of malachite green (MG) was studied in Aspergillus niger in the presence and absence of calcium chloride stress. Decolorization took place within 24 h, and a signal transduction process that initiated MG decolorization was suggested to be involved. In the present study, further investigation of the relationship between calcium chloride stress and enhanced MG biodegradation was conducted at the sub-cellular level. MG-NADH reductase activity, a key enzyme in MG decolorization, was produced as decolorization commenced, and enzyme activity increased threefold upon exposure to calcium chloride. Inhibitors of cytochrome p450, Ca(2+) channel activity as well as activity of the signaling protein phosphoinositide 3-kinase were tested. All three activities were inhibited to different extents resulting in reduced MG decolorization. Spectral analysis of the mitochondrial fraction showed a heme signal at 405 nm and A405/A280 ratio that is characteristic of the porphoryin ring of cytochromes. There were no peaks detected for cytochromes a or b, but a shoulder appearing at 550 nm was observed, which suggested that cytochrome c is involved; the absorbance for cytochrome c doubled after calcium chloride stress supporting this idea. MG decolorization took place via a series of demethylation steps, and cytotoxicity analysis revealed a decrease in the toxicity associated with generation of leucomalachite green.

  17. The effect of calcium chloride injection on shear force and caspase activities in bovine longissimus muscles during postmortem conditioning.

    PubMed

    Cao, J; Yu, X; Khan, M A; Shao, J; Xiang, Y; Zhou, G

    2012-06-01

    Tenderness is considered as the most important quality determinant of meat. Calcium chloride application has been shown to improve tenderness by regulating endogenous proteinases. This study was designed to determine the effect of 300 mM calcium chloride injection on myofibrillar structures, caspase activities and shear force in longissimus muscles of bulls during postmortem storage of 7 days. Myofibrillar fragmentation index was determined as an index of proteolysis occurring in muscle fibers and associated proteins. Maximum tenderness was observed at days 4 and 7 in both treated and control samples. The injection of calcium chloride significantly increased myofibrillar proteolysis and improved tenderness at postmortem days 4 and 7. The treatment reduced caspase-9 activity at 4 h and day 4, whereas those of caspase-8 and -3 activities at days 1 and 4 with respect to control. The improved tenderness and increased myofibril fragmentation with decreased caspase activities suggested that the proteolytic systems activated with calcium chloride injection possibly behave independent of the caspase system.

  18. Study of permeation and blocker binding in TMEM16A calcium-activated chloride channels.

    PubMed

    Reyes, J P; Huanosta-Gutiérrez, A; López-Rodríguez, A; Martínez-Torres, A

    2015-01-01

    We studied the effects of mutations of positively charged amino acid residues in the pore of X. tropicalis TMEM16A calcium-activated chloride channels: K613E, K628E, K630E; R646E and R761E. The activation and deactivation kinetics were not affected, and only K613E showed a lower current density. K628E and R761E affect anion selectivity without affecting Na(+) permeation, whereas K613E, R646E and the double mutant K613E + R646E affect anion selectivity and permeability to Na(+). Furthermore, altered blockade by the chloride channel blockers anthracene-9-carboxylic acid (A-9-C), 4, 4'-Diisothiocyano-2,2'-stilbenedisulfonic acid (DIDS) and T16inh-A01 was observed. These results suggest the existence of 2 binding sites for anions within the pore at electrical distances of 0.3 and 0.5. These sites are also relevant for anion permeation and blockade.

  19. Alleviation of silver toxicity by calcium chloride (CaCl2) in Lemna gibba L.

    PubMed

    Oukarroum, Abdallah; Gaudreault, Marie-Hélène; Pirastru, Laura; Popovic, Radovan

    2013-10-01

    The toxicity effects of silver (Ag) and the protective role of calcium chloride (CaCl2) was studied in Lemna gibba L. (L. gibba) plants. Silver speciation showed that silver toxicity in L. gibba culture medium can be attributed to free ionic Ag(+) concentration. Frond abscission, intracellular reactive oxygen species (ROS) formation and intracellular uptake of Ag(+) were investigated when L. gibba plants were exposed to AgNO3 concentrations (0.5, 1, 5, and 10 μM) supplemented or not by 10 μM CaCl2. An increase in frond abscission, intracellular ROS and intracellular uptake of Ag(+) were detected in L. gibba plants for all tested concentrations of AgNO3 after 24 h treatment. However, addition of 10 μM CaCl2 to the L. gibba culture medium reduced the toxic effects of Ag by decreasing silver uptake into the plant and intracellular ROS formation. The results suggest that Ag-induced toxicity was attributed to Ag(+) accumulation and chloride was able to protect L. gibba plants against Ag toxicity by formation of complexes with Ag and then alleviation of the metal induced oxidative stress.

  20. Alleviation of silver toxicity by calcium chloride (CaCl2) in Lemna gibba L.

    PubMed

    Oukarroum, Abdallah; Gaudreault, Marie-Hélène; Pirastru, Laura; Popovic, Radovan

    2013-10-01

    The toxicity effects of silver (Ag) and the protective role of calcium chloride (CaCl2) was studied in Lemna gibba L. (L. gibba) plants. Silver speciation showed that silver toxicity in L. gibba culture medium can be attributed to free ionic Ag(+) concentration. Frond abscission, intracellular reactive oxygen species (ROS) formation and intracellular uptake of Ag(+) were investigated when L. gibba plants were exposed to AgNO3 concentrations (0.5, 1, 5, and 10 μM) supplemented or not by 10 μM CaCl2. An increase in frond abscission, intracellular ROS and intracellular uptake of Ag(+) were detected in L. gibba plants for all tested concentrations of AgNO3 after 24 h treatment. However, addition of 10 μM CaCl2 to the L. gibba culture medium reduced the toxic effects of Ag by decreasing silver uptake into the plant and intracellular ROS formation. The results suggest that Ag-induced toxicity was attributed to Ag(+) accumulation and chloride was able to protect L. gibba plants against Ag toxicity by formation of complexes with Ag and then alleviation of the metal induced oxidative stress. PMID:23974355

  1. Depolarizing chloride gradient in developing cochlear nucleus neurons: underlying mechanism and implication for calcium signaling.

    PubMed

    Witte, M; Reinert, T; Dietz, B; Nerlich, J; Rübsamen, R; Milenkovic, I

    2014-03-01

    Precise regulation of the chloride homeostasis crucially determines the action of inhibitory transmitters GABA and glycine and thereby endows neurons or even discrete neuronal compartments with distinct physiological responses to the same transmitters. In mammals, the signaling mediated by GABAA/glycine receptors shifts during early postnatal life from depolarization to hyperpolarization, due to delayed maturation of the chloride homeostasis system. While the activity of the secondary active, K(+)-Cl(-)-extruding cotransporter KCC2, renders GABA/glycine hyperpolarizing in auditory brainstem nuclei of altricial rodents, the mechanisms contributing to the initially depolarizing transmembrane gradient for Cl(-) in respective neurons remained unknown. Here we used gramicidin-perforated patch recordings, non-invasive Cl(-) and Ca(2+) imaging, and immunohistochemistry to identify the Cl(-)-loading transporter that renders depolarizing effects of GABA/glycine in early postnatal life of spherical bushy cells in the cochlear nucleus of gerbil. Our data identify the 1Na(+):1K(+):2Cl(-) cotransporter 1 (NKCC1) as the major Cl(-)-loader responsible for depolarizing action of GABA/glycine at postnatal days 3-5 (P3-5). Extracellular GABA/muscimol elicited calcium signaling through R-, L-, and T-type channels, which was dependent on bumetanide- and [Na(+)]e-sensitive Cl(-) accumulation. The "adult like", low intracellular Cl(-) concentration is established during the second postnatal week, through a mechanism engaging the NKCC1-down regulation between P5 and P15 and ongoing KCC2-mediated Cl(-)-extrusion.

  2. Depolarizing chloride gradient in developing cochlear nucleus neurons: underlying mechanism and implication for calcium signaling.

    PubMed

    Witte, M; Reinert, T; Dietz, B; Nerlich, J; Rübsamen, R; Milenkovic, I

    2014-03-01

    Precise regulation of the chloride homeostasis crucially determines the action of inhibitory transmitters GABA and glycine and thereby endows neurons or even discrete neuronal compartments with distinct physiological responses to the same transmitters. In mammals, the signaling mediated by GABAA/glycine receptors shifts during early postnatal life from depolarization to hyperpolarization, due to delayed maturation of the chloride homeostasis system. While the activity of the secondary active, K(+)-Cl(-)-extruding cotransporter KCC2, renders GABA/glycine hyperpolarizing in auditory brainstem nuclei of altricial rodents, the mechanisms contributing to the initially depolarizing transmembrane gradient for Cl(-) in respective neurons remained unknown. Here we used gramicidin-perforated patch recordings, non-invasive Cl(-) and Ca(2+) imaging, and immunohistochemistry to identify the Cl(-)-loading transporter that renders depolarizing effects of GABA/glycine in early postnatal life of spherical bushy cells in the cochlear nucleus of gerbil. Our data identify the 1Na(+):1K(+):2Cl(-) cotransporter 1 (NKCC1) as the major Cl(-)-loader responsible for depolarizing action of GABA/glycine at postnatal days 3-5 (P3-5). Extracellular GABA/muscimol elicited calcium signaling through R-, L-, and T-type channels, which was dependent on bumetanide- and [Na(+)]e-sensitive Cl(-) accumulation. The "adult like", low intracellular Cl(-) concentration is established during the second postnatal week, through a mechanism engaging the NKCC1-down regulation between P5 and P15 and ongoing KCC2-mediated Cl(-)-extrusion. PMID:24388924

  3. Solution-Derived, Chloride-Containing Minerals as a Waste Form for Alkali Chlorides

    SciTech Connect

    Riley, Brian J.; Crum, Jarrod V.; Matyas, Josef; McCloy, John S.; Lepry, William C.

    2012-10-01

    Sodalite [Na8(AlSiO4)6Cl2] and cancrinite [(Na,K)6Ca2Al6Si6O24Cl4] are environmentally stable, chloride-containing minerals and are a logical waste form option for the mixed alkali chloride salt waste stream that is generated from a proposed electrochemical separations process during nuclear fuel reprocessing. Due to the volatility of chloride salts at moderate temperatures, the ideal processing route for these salts is a low-temperature approach such as the sol-gel process. The sodalite structure can be easily synthesized by the sol-gel process; however, it is produced in the form of a fine powder with particle sizes on the order of 1–10 µm. Due to the small particle size, these powders require additional treatment to form a monolith. In this study, the sol-gel powders were pressed into pellets and fired to achieve > 90% of theoretical density. The cancrinite structure, identified as the best candidate mineral form in terms of waste loading capacity, was only produced on a limited basis following the sol-gel process and converted to sodalite upon firing. Here we discuss the sol-gel process specifics, chemical durability of select waste forms, and the steps taken to maximize chloride-containing phases, decrease chloride loss during pellet firing, and increase pellet densities.

  4. Copper extraction from chloride solutions with mixtures of solvating and chelating reagents

    SciTech Connect

    Borowiak-Resterna, A.; Szymanowski, J.

    2000-01-01

    Equimolar mixtures of N,N,N{prime},N{prime}-tetrahexylpyridine-3,5-dicarboxamide (L) with 2-hydroxy-5-t-octylbenzophenone oxime or 1-phenyldecane-1,3-dione (HB), were used to extract copper from chloride solutions of various concentration of chloride ions. Chloride ions were then scrubbed out with water or ammoniacal solutions and copper was transferred from the solvate CuCl{sub 2}L{sub 2} to chelate CuB{sub 2}. Both studied systems permit effective extraction of copper and removal of chloride ions from the organic phase. Some protonation of solvating reagent L occurs, however, when copper is stripped from the chelate with hydroxyoxime. This negative effect can be suppressed when 1-phenyldecane-1,3-dione is used as a chelating agent. The scrubbing of chloride ions must be then carried out with ammoniacal solutions to avoid simultaneous stripping of copper.

  5. Effect of chloride concentration on the pitting and repassivation potentials of reinforcing steel in alkaline solutions

    SciTech Connect

    Li, L.

    1999-11-01

    Reinforcing steel bars ({approximately}12mm diameter and 150mm long) were used in cyclic polarization tests in saturated Ca(OH){sub 2} solution and simulated concrete pore solution (SPS) with various levels of sodium chloride addition. Below a limiting chloride level ({approximately}O.004M [Cl{sup {minus}}] in Ca(OH){sub 2} solution and {approximately}0.4M [Cl{sup {minus}}] in SPS solution), steel was not found to undergo pitting corrosion even if it was polarized to the oxygen evolution potential ({approximately}O.6V/SCE). At higher NaCl addition, pitting corrosion could often be initiated but the pitting potential was non-deterministic to a great extent. In Ca(OH){sub 2} solution the average pitting potential was found to be strongly dependent on chloride concentration when [Cl{sup {minus}}]{ge}0.008M. In SPS solution, the average pitting potential was almost independent of the chloride concentration when [Cl{sup {minus}}]{ge}0.8M. The repassivation potential was found to be a strong function of the severity of corrosion attack that has occurred on the steel surface before repassivation, rather than a function of the chloride content of the bulk solution. The pitting tendency in chloride-containing SPS and Ca(OH){sub 2} solutions was interpreted on a statistical basis. The threshold thus determined good agreement with other values reported in the literature.

  6. Photoinduced crystallization of calcium carbonate from a homogeneous precursor solution in the presence of partially hydrolyzed poly(vinyl alcohol)

    NASA Astrophysics Data System (ADS)

    Nishio, Takashi; Naka, Kensuke

    2015-04-01

    Photoinduced crystallization of calcium carbonate (CaCO3) was demonstrated by the photodecarboxylation of ketoprofen (KP, 2-(3-benzoylphenyl)propionic acid) under alkaline conditions (pH 10). In this method, a homogeneous solution comprising KP, calcium chloride, ammonia, and partially hydrolyzed poly(vinyl alcohol) (PVAPS, degree of saponification: 86.5-89.0 mol %) was used as the precursor solution and was exposed to ultraviolet (UV) irradiation for different time periods. Thermogravimetric analysis of the obtained xerogels showed that increasing the UV irradiation time increased the amount of CaCO3 formed and the complete conversion of calcium ions to calcite was achieved after 50 min of UV irradiation. Furthermore, solid phase analyses suggested that nanometer-to-micron-sized calcite crystals were formed and dispersed in the obtained PVAPS matrix.

  7. Microelectrophoretic study of calcium oxalate monohydrate in macromolecular solutions

    NASA Technical Reports Server (NTRS)

    Curreri, P. A.; Onoda, G. Y., Jr.; Finlayson, B.

    1987-01-01

    Electrophoretic mobilities were measured for calcium oxalate monohydrate (COM) in solutions containing macromolecules. Two mucopolysaccharides (sodium heparin and chondroitin sulfate) and two proteins (positively charged lysozyme and negatively charged bovine serum albumin) were studied as adsorbates. The effects of pH, calcium oxalate surface charge (varied by calcium or oxalate ion activity), and citrate concentration were investigated. All four macromolecules showed evidence for adsorption. The macromolecule concentrations needed for reversing the surface charge indicated that the mucopolysaccharides have greater affinity for the COM surface than the proteins. Citrate ions at high concentrations appear to compete effectively with the negative protein for surface sites but show no evidence for competing with the positively charged protein.

  8. Precipitation of calcium oxalates from high ionic strength solutions IV. Testing of kinetic models*1

    NASA Astrophysics Data System (ADS)

    Skrtic, D.; Markovic, M.; Foredi-Milhofer, H.

    1986-12-01

    The following parameters characterizing the kinetics of precipitation from unseeded solutions are defined: the induction period ( ti), the maximum precipitation rate ( Rmax), the number of particles per cm 3 ( N), the order ( p) and rate constants ( Kα, Ks) of the crystal growth process, the critical time ( taggr∗), the critical supersaturation ( Saggr∗) and the rate constant of aggregation ( kj) as well as the relative changes in the surface area ( ΔP/ P) and the degree of the reaction (Δα/α) due to aggregation. The information which these parameters yield on nucleation, crystal growth and aggregation is evaluated. The model is applied to the precipitation of calcium oxalate trihydrate (COT) from 0.3 molar sodium chloride solutions, with and without the presence of tryptophan or ornithine. At the given concentrations both aminoacids inhibit crystal growth and change the mode of aggregation of COT.

  9. Polymerization of calcium caseinates solutions induced by gamma irradiation

    NASA Astrophysics Data System (ADS)

    Lacroix, M.; Jobin, M.; Mezgheni, E.; Srour, M.; Boileau, S.

    1998-06-01

    Solutions of calcium caseinate (5%) combined with propylene glycol (PG) or triethylene glycol(TEG) (0, 2.5% and 5%) and used for the development of edible films and coatings, were irradiated at doses between 0 to 128 kGy. Solutions were chromatographed through toyopearl HW 55F resin to observe the effect of irradiation on cross-link reactions. In unirradiated calcium caseinate solutions, two peaks could be observed (fractions 30 and 37) while samples irradiated at 64 kGy and 128 kGy showed one shifted peak at fraction 32 and 29 respectively. No effect of the plasticizers was observed. According to proteins standards of knowed molecular weights, the molecular weight of calcium caseinate increased approximately 10 times when irradiated at 128 kGy and 5 times when irradiated at 64 kGy. The physico-chemical properties of bio-films prepared with the irradiated solutions, demonstrated that tensile strength at break increased with increase of irradiation dose. A maximum dose was obtained at 16 kGy.

  10. A glass-encapsulated calcium phosphate wasteform for the immobilization of actinide-, fluoride-, and chloride-containing radioactive wastes from the pyrochemical reprocessing of plutonium metal

    NASA Astrophysics Data System (ADS)

    Donald, I. W.; Metcalfe, B. L.; Fong, S. K.; Gerrard, L. A.; Strachan, D. M.; Scheele, R. D.

    2007-03-01

    Chloride-containing radioactive wastes are generated during the pyrochemical reprocessing of Pu metal. Immobilization of these wastes in borosilicate glass or Synroc-type ceramics is not feasible due to the very low solubility of chlorides in these hosts. Alternative candidates have therefore been sought including phosphate-based glasses, crystalline ceramics and hybrid glass/ceramic systems. These studies have shown that high losses of chloride or evolution of chlorine gas from the melt make vitrification an unacceptable solution unless suitable off-gas treatment facilities capable of dealing with these corrosive by-products are available. On the other hand, both sodium aluminosilicate and calcium phosphate ceramics are capable of retaining chloride in stable mineral phases, which include sodalite, Na 8(AlSiO 4) 6Cl 2, chlorapatite, Ca 5(PO 4) 3Cl, and spodiosite, Ca 2(PO 4)Cl. The immobilization process developed in this study involves a solid state process in which waste and precursor powders are mixed and reacted in air at temperatures in the range 700-800 °C. The ceramic products are non-hygroscopic free-flowing powders that only require encapsulation in a relatively low melting temperature phosphate-based glass to produce a monolithic wasteform suitable for storage and ultimate disposal.

  11. Consumer Acceptability of Cucumber Pickles Produced by Fermentation in Calcium Chloride Brine for Reduced Environmental Impact.

    PubMed

    Wilson, Emily M; Johanningsmeier, Suzanne D; Osborne, Jason A

    2015-06-01

    Fermentation of cucumbers in calcium chloride (CaCl2 ) brine has been proposed as an alternative process to reduce the environmental impact of traditional, high salt fermentations. The objective of this research was to determine whether consumer acceptability of pickle products would be impacted by fermentation and storage of cucumbers in CaCl2 brine. Cucumbers were fermented and stored with 0.1M CaCl2 or 1M sodium chloride (NaCl) in open-air, 3000 gal tanks at a commercial facility and processed into hamburger dill chips containing 0.38M NaCl. Cucumbers fermented in CaCl2 required additional desalting to reduce CaCl2 concentrations to that of current products. Consumers (n = 101) showed no significant preference for pickles from different fermentation treatments, whether stored for 2 mo (P = 0.75) or 8 mo (P = 0.68) prior to processing. In contrast, NaCl fermented pickles were preferred over CaCl2 fermented pickles stored for 10 mo and desalted only once (P < 0.01). A series of preference tests indicated that the taste of CaCl2 was not the factor affecting consumer preference, and the 50% detection threshold of CaCl2 in dill pickle chips was found to be 61.8 ± 7.6 mM, indicating that processors could potentially use CaCl2 fermentations with a single desalting step. Consumer liking of flavor (n = 73) was not influenced by fermentation in CaCl2 or by 23 or 35 mM CaCl2 in finished products (P > 0.05), but variability in texture decreased consumer liking (P < 0.05). Although promising, individual fermentation variability and texture quality of CaCl2 fermented products should be further evaluated prior to broad implementation of this process.

  12. Sealing ability of MTA and radiopaque Portland cement with or without calcium chloride for root-end filling.

    PubMed

    Bortoluzzi, Eduardo Antunes; Broon, Norberto Juárez; Bramante, Clovis Monteiro; Garcia, Roberto Brandão; de Moraes, Ivaldo Gomes; Bernardineli, Norberti

    2006-09-01

    The aim of this study was to evaluate the influence of calcium chloride (CaCl(2)) on the sealing ability of three Mineral Trioxide Aggregate (MTA) cements, ProRoot MTA, MTA-Angelus, and radiopaque White Portland cement (WPC), for retrograde root filling. Seventy roots of extracted single-rooted teeth were instrumented and obturated. After sectioning the samples at 2 mm from the apex, they received one layer of Araldite and two coats of nail enamel, except for the apical dentinal surface submitted to apicectomy. Standardized retrograde cavities were prepared, filled with one of the materials, and immersed in 0.2% Rhodamine B solution for 72 hours. Dye leakage was analyzed on a light microscope with ocular micrometer. Kruskal-Wallis and Miller tests were used to compare groups arranged in increasing order of leakage, according to mean rank of scores: WPC+CaCl(2), MTA-Angelus+CaCl(2), ProRoot MTA+CaCl(2), MTA-Angelus, ProRoot MTA, and WPC. CaCl(2) improved the sealing ability of all three MTA cements.

  13. A diffusive anomaly of water in aqueous sodium chloride solutions at low temperatures.

    PubMed

    Kim, Jun Soo; Yethiraj, Arun

    2008-02-14

    Molecular dynamics simulations are presented for the self-diffusion coefficient of water in aqueous sodium chloride solutions. At temperatures above the freezing point of pure water, the self-diffusion coefficient is a monotonically decreasing function of salt concentration. Below the freezing point of pure water, however, the self-diffusion coefficient is a non-monotonic function of salt concentration, showing a maximum at approximately one molal salt. This suggests that sodium chloride, which is considered a structure-making salt at room temperature, becomes a structure-breaking salt at low temperatures. A qualitative understanding of this effect can be obtained by considering the effect of ions on the residence time of water molecules near other water molecules. A consideration of the freezing point depression of aqueous sodium chloride solutions suggests that the self-diffusion coefficient of water in supercooled sodium chloride solutions is always higher than that in pure (supercooled) water at the same temperature.

  14. Aggrandizing power output from Shewanella oneidensis MR-1 microbial fuel cells using calcium chloride.

    PubMed

    Fitzgerald, Lisa A; Petersen, Emily R; Gross, Benjamin J; Soto, Carissa M; Ringeisen, Bradley R; El-Naggar, Mohamed Y; Biffinger, Justin C

    2012-01-15

    There are several interconnected metabolic pathways in bacteria essential for the conversion of carbon electron sources directly into electrical currents using microbial fuel cells (MFCs). This study establishes a direct exogenous method to increase power output from a Shewanella oneidensis MR-1 containing MFC by adding calcium chloride to the culture medium. The current output from each CaCl(2) concentration tested revealed that the addition of CaCl(2) to 1400 μM increased the current density by >80% (0.95-1.76 μA/cm(2)) using sodium lactate as the sole carbon source. Furthermore, polarization curves showed that the maximum power output could be increased from 157 to 330 μW with the addition of 2080 μM CaCl(2). Since the conductivity of the culture medium did not change after the addition of CaCl(2) (confirmed by EIS and bulk conductivity measurements), this increase in power was primarily biological and not based on ionic effects. Thus, controlling the concentration of CaCl(2) is a pathway to increase the efficiency and performance of S. oneidensis MR-1 MFCs.

  15. The plasticizing mechanism and effect of calcium chloride on starch/poly(vinyl alcohol) films.

    PubMed

    Jiang, Xiancai; Jiang, Ting; Gan, Lingling; Zhang, Xiaofei; Dai, Hua; Zhang, Xi

    2012-11-01

    Starch/poly(vinyl alcohol) (PVA) films were prepared with calcium chloride (CaCl(2)) as the plasticizer. The micro morphology of pure starch/PVA film and CaCl(2) plasticized starch/PVA film was observed by scanning electron microscope. The interaction between CaCl(2) and starch/PVA molecules was investigated by Fourier transform infrared spectroscopy. The influence of CaCl(2) on the crystalline, thermal and mechanical properties of starch/PVA films was studied by X-ray diffraction, differential scanning calorimetry, thermogravimetric analysis, and tensile testing, respectively. The results indicated that CaCl(2) could interact with starch and PVA molecules and then effectively destroy the crystals of starch and PVA. Starch/PVA films plasticized with CaCl(2) became soft and ductile, with lower tensile strength and higher elongation at break compared with pure starch/PVA film. The water content of starch/PVA film would increase with the addition of CaCl(2). This is an important cause of the plasticization of CaCl(2) on starch/PVA film.

  16. Effect of Calcium Sulphate Nanoparticles on Fusion, Mechanical and Thermal Behaviour Polyvinyl Chloride (pvc)

    NASA Astrophysics Data System (ADS)

    Patil, C. B.; Shisode, P. S.; Kapadi, U. R.; Hundiwale, D. G.; Mahulikar, P. P.

    Calcium Sulphate [CaSO4] was synthesized by in-situ deposition technique and its nano size (60 to 100 nm) was confirmed by Transmission Electron Microscopy (TEM). Composites of the filler CaSO4 (micro and nano) and the matrix poly (vinyl chloride) (PVC) were prepared with different filler loading (0-5 wt. %) by melt mixing. The Brabender torque rheometer equipped with an internal mixer was used for preparation and evaluation of fusion behaviour of composites of different formulations. The effect of nano and micro-CaSO4 content on the structure and properties of composites was studied. The nanostructures and dispersion were studied by wide angle X-ray diffraction (WAXD) and scanning electron microscopy (SEM). The mechanical and thermal properties of PVC/ micro and nano-CaSO4 composites were characterized using Universal Testing Machine (UTM) and Thermo Gravimetric Analyzer (TGA). From the results of WAXD and SEM the flocculation of CaSO4 nanoparticles were observed on the surfaces of PVC matrix. The thermal analysis results showed that the first thermal degradation onset (T onset) of PVC/nano-CaSO4 composites for 1 wt. % of filler were higher as compared with corresponding microcomposites and pristine PVC. However, the tensile strength was decreasing with increasing filler content while, it shows increment in magnitude at 1 and 2 wt. % of nano-CaSO4 as compared with corresponding micro-CaSO4 as well as pristine PVC.

  17. Brillouin scattering study of the ferroelectric phase transition in tris-sarcosine calcium chloride

    NASA Astrophysics Data System (ADS)

    Hikita, Tomoyuki; Schnackenberg, Paul; Schmidt, V. Hugo

    1985-01-01

    Brillouin spectra from longitudinal phonons in ferroelectric tris-sarcosine calcium chloride propagating along [100], [010], and [001] have been measured as functions of temperature. Large anomalies were found in the Brillouin shift and linewidth in the [100] and [001] phonons. These anomalies are interpreted as arising from the linear coupling of the polarization and the phonons. From the temperature where the linewidth is maximum, the relaxation time of the polarization fluctuations is estimated to be τ=3.1×10-12/(Tc-T) sec, where Tc is the ferroelectric transition temperature. We also observed anomalies in Brillouin shift and linewidth of the [010] phonons which propagate along the ferroelectric b axis. These anomalies are interpreted as coming from electro- strictive coupling. The energy-relaxation time was estimated to be τE=2.5×10-10/(T-Tc) sec in the paraelectric phase and τE=1.0×10-9/(Tc-T) sec in the ferroelectric phase, by comparing our Brillouin results with those of the ultrasonic measurements.

  18. Coadministration of calcium chloride with lead acetate can improve motility of cauda epididymal spermatozoa in Swiss white mice

    PubMed Central

    Golshan Iranpour, Farhad; Kheiri, Soleiman

    2016-01-01

    Background: Lead is an industrial heavy metal that can decrease sperm motility. Objective: The aim was to investigate the protective effects of calcium against lead on motility of spermatozoa. Materials and Methods: In total 40 adult male Swiss white mice were randomly divided into 5 groups (control, lead of 1st wk, lead of 2nd wk, lead/calcium of 1st wk and lead/calcium of 2nd wk). The lead groups of mice were injected by a single dose of lead acetate (200 mg/kg) intraperitoneally. Lead/calcium groups of mice were injected by a single same dose of lead acetate along with three doses of 80 mg/kg calcium chloride. The control group of mice was injected only with same volume of distilled water through the same route. Mice of 1st and 2nd wk groups were sacrificed through cervical dislocation one and two weeks after injections respectively. Results: Mean of the progressive motile spermatozoa of cauda epididymis in lead/calcium group of the first week was higher than the lead group of the first week and this difference was significant. There was not any significant difference among weight of testes and epididymides of all groups. Conclusion: It can be concluded that calcium can decrease the effects of lead on sperm motility. PMID:27200429

  19. Effect of calcium chloride addition and draining pH on the microstructure and texture of full fat Cheddar cheese during ripening.

    PubMed

    Soodam, Kevany; Ong, Lydia; Powell, Ian B; Kentish, Sandra E; Gras, Sally L

    2015-08-15

    Calcium chloride is commonly added to cheese-milk to improve coagulum formation and to increase cheese yield but high concentrations of calcium ions can have adverse effects. In this study, confocal laser scanning microscopy and cryo-scanning electron microscopy were coupled with textural and chemical analyses to observe microstructural and biochemical changes that occur in cheese during ripening when calcium chloride is added or the draining pH altered. For the cheese prepared with no additional calcium at a draining pH of 6.0, the cheese porosity increased with ripening time and the number of protein vertices in the microscopy images declined, indicative of protein solubilisation. As the amount of CaCl2 added was increased, however, these changes became less significant. Our findings show that calcium chloride addition can be used, together with a lower draining pH, to alter the manufacturing process without significantly impacting on the quality of the mature cheese.

  20. Interactions of copper (II) chloride with sucrose, glucose, and fructose in aqueous solutions

    NASA Astrophysics Data System (ADS)

    Ribeiro, A. C. F.; Esteso, M. A.; Lobo, V. M. M.; Valente, A. J. M.; Simões, S. M. N.; Sobral, A. J. F. N.; Burrows, H. D.

    2007-01-01

    The interaction between copper (II) chloride and the carbohydrates sucrose, glucose, and fructose has been studied in aqueous solutions at 298.15 and 310.15 K, using measurements of diffusion coefficients and electrical conductivity. Significant effects on the electrical conductivity were observed in the presence of these carbohydrates, suggesting interactions between them and copper chloride. Support for this came from diffusion coefficient measurements. These studies have been complemented by molecular mechanics calculations.

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

    PubMed

    Dworin, A; Sober, A J

    1978-05-01

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

  2. Evaluation of the bone healing process utilizing platelet-rich plasma activated by thrombin and calcium chloride: a histologic study in rabbit calvaria.

    PubMed

    Betoni-Junior, Walter; Dechichi, Paula; Esteves, Jônatas Caldeira; Zanetta-Barbosa, Darceny; Magalhães, Aparecido Eurípedes Onório

    2013-02-01

    To evaluate the bone healing of defects filled with particulate bone graft in combination with platelet-rich plasma (PRP), added with a mixture of calcium chloride and thrombin or just calcium chloride. Two 5-mm bone defects were created in the calvaria of 24 rabbits. Each defect was filled with particulate bone graft and PRP. In one defect the PRP was activated by a mixture of calcium chloride and thrombin; in the other, PRP was activated by calcium chloride only. The animals were euthanized 1, 2, 4, and 8 weeks after the surgeries, and the calvaria was submitted to histologic processing for histomorphometric analysis. The qualitative analysis has shown that both defects presented the same histologic characteristics so that a better organized, more mature, and well-vascularized bone tissue was noticed in the eighth week. A good bone repair was achieved using either the mixture of calcium chloride and thrombin or the calcium chloride alone as a restarting agent of the coagulation process.

  3. Possibility of inhibition of calcium-activated chloride channel rescuing erectile failures in diabetes.

    PubMed

    Lau, L-C; Adaikan, P G

    2014-01-01

    Although calcium-activated chloride channel (CaCC) blockers, niflumic acid (NFA) and anthracene-9-carboxylic acid (A9C), have been shown as potential erectogenic agents in healthy corpus cavernosum (CC) tissues, the pharmacological characteristics of CaCC blockers in diabetic state are relatively unknown. This study compares the direct muscle relaxant property of NFA and A9C with their influence on contraction and nitrergic relaxation as elicited by electrical field stimulation in normal and 16-week-old diabetic rabbit CC (n=8). Mean blood glucose level in alloxan-treated rabbits was elevated threefold (21.9±0.5 mmol  l(-1) vs 7.1±0.2 mmol l(-1) in untreated rabbits; P<0.05). There was no significant alteration in the efficacies of NFA and A9C in eliciting a concentration-dependent relaxation of noradrenaline-induced cavernosum tone and in inhibiting neurogenic contraction of CC from diabetic rabbits. The capability of NFA (100 μM) and A9C (1 mM) in augmenting nitrergic transmission was also not adversely affected by diabetes. However, in CC from diabetic rabbits, A9C markedly increased nitrergic relaxation response to 1-10 Hz by 10.6-36.6% (vs -5.1-0.8% in nondiabetic control). CaCC sensitivity to A9C appears to be enhanced in diabetic CC tissue. Inhibiting the CaCC activity in diabetes-related ED may tip the balance between proerectile/relaxant and antierectile/contractile mechanisms in favor of cavernosum relaxation.

  4. TRPC1 regulates calcium-activated chloride channels in salivary gland cells.

    PubMed

    Sun, Yuyang; Birnbaumer, Lutz; Singh, Brij B

    2015-11-01

    Calcium-activated chloride channel (CaCC) plays an important role in modulating epithelial secretion. It has been suggested that in salivary tissues, sustained fluid secretion is dependent on Ca(2+) influx that activates ion channels such as CaCC to initiate Cl(-) efflux. However direct evidence as well as the molecular identity of the Ca(2+) channel responsible for activating CaCC in salivary tissues is not yet identified. Here we provide evidence that in human salivary cells, an outward rectifying Cl(-) current was activated by increasing [Ca(2+)]i, which was inhibited by the addition of pharmacological agents niflumic acid (NFA), an antagonist of CaCC, or T16Ainh-A01, a specific TMEM16a inhibitor. Addition of thapsigargin (Tg), that induces store-depletion and activates TRPC1-mediated Ca(2+) entry, potentiated the Cl(-) current, which was inhibited by the addition of a non-specific TRPC channel blocker SKF96365 or removal of external Ca(2+). Stimulation with Tg also increased plasma membrane expression of TMEM16a protein, which was also dependent on Ca(2+) entry. Importantly, in salivary cells, TRPC1 silencing, but not that of TRPC3, inhibited CaCC especially upon store depletion. Moreover, primary acinar cells isolated from submandibular gland also showed outward rectifying Cl(-) currents upon increasing [Ca(2+)]i. These Cl(-) currents were again potentiated with the addition of Tg, but inhibited in the presence of T16Ainh-A01. Finally, acinar cells isolated from the submandibular glands of TRPC1 knockout mice showed significant inhibition of the outward Cl(-) currents without decreasing TMEM16a expression. Together the data suggests that Ca(2+) entry via the TRPC1 channels is essential for the activation of CaCC.

  5. Redox flow batteries based on supporting solutions containing chloride

    SciTech Connect

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

    2015-09-01

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

  6. Redox flow batteries based on supporting solutions containing chloride

    SciTech Connect

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

    2014-01-14

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

  7. Redox flow batteries based on supporting solutions containing chloride

    SciTech Connect

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

    2015-07-07

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

  8. The electrokinetic behavior of calcium oxalate monohydrate in macromolecular solutions

    NASA Technical Reports Server (NTRS)

    Curreri, P. A.; Onoda, G. Y., Jr.; Finlayson, B.

    1988-01-01

    Electrophoretic mobilities were measured for calcium oxalate monohydrate (COM) in solutions containing macromolecules. Two mucopolysaccharides (sodium heparin and chrondroitin sulfate) and two proteins (positively charged lysozyme and negatively charged bovine serum albumin) were studied as adsorbates. The effects of pH, calcium oxalate surface charge (varied by calcium or oxalate ion activity), and citrate concentration were investigated. All four macromolecules showed evidence for chemical adsorption. The macromolecule concentrations needed for reversing the surface charge indicated that the mucopopolysacchrides have greater affinity for the COM surface than the proteins. The amount of proteins that can chemically adsorb appears to be limited to approximately one monomolecular layer. When the surface charge is high, an insufficient number of proteins can chemically adsorb to neutralize or reverse the surface charge. The remaining surface charge is balanced by proteins held near the surface by longer range electrostatic forces only. Citrate ions at high concentrations appear to compete effectively with the negative protein for surface sites but show no evidence for competing with the positively charged protein.

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

    DOEpatents

    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)

  10. Leaching of diethylhexyl phthalate from polyvinyl chloride bags into intravenous cyclosporine solution

    SciTech Connect

    Venkataramanan, R.; Burckart, G.J.; Ptachcinski, R.J.; Blaha, R.; Logue, L.W.; Bahnson, A.; Giam, C.S.; Brady, J.E.

    1986-11-01

    The release of diethylhexyl phthalate (DEHP) from flexible polyvinyl chloride containers into intravenous cyclosporine solutions was studied. Intravenous cyclosporine solution or solutions containing the vehicle Cremophor EL and alcohol in dextrose were prepared in an all-glass system and stored in polyvinyl chloride (PVC) bags. Four samples were obtained at different time intervals, and DEHP content was analyzed by gas chromatography. The amount of DEHP that was leached into solutions stored in the PVC bags increased as storage time increased. By 48 hours, nearly 33 mg of DEHP had leached into the solution. Intravenous cyclosporine solutions should be prepared in glass containers to minimize patient exposure to DEHP. If plastic bags are used for preparing cyclosporine injections, the injections must be used immediately after preparation.

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

    PubMed

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

    2016-01-20

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

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

    PubMed Central

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

    2010-01-01

    One type of all-solid-state chloride sensor was fabricated using a MnO2 electrode and a Ag/AgCl electrode. The potentiometric response of the sensor to chloride in synthetic concrete pore solutions was systematically studied, and the polarization performance was also evaluated. The results show a good linear relationship between the potential reading of the sensor and the logarithm of chloride activity (concentration ranges from 0.05 to 5.0 M), and the potential value remains stable with 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. PMID:22163467

  13. Nucleation and growth of zinc from chloride concentrated solutions

    SciTech Connect

    Trejo, G.; Ortega B, R.; Meas V, Y.; Ozil, P.; Chainet, E.; Nguyen, B.

    1998-12-01

    The electrodeposition of metals is a complex phenomenon influenced by a number of factors that modify the rates of nucleation and growth and determine the properties of the deposits. In this work the authors study the influence of the zinc chloride (ZnCl{sub 2}) concentration on the zinc nucleation process on glassy carbon, in a KCl electrolyte under conditions close to those employed in commercial acid deposition baths for zinc. The electrochemical study was performed using cyclic voltammetry and potentiostatic current-time transients. The charge-transfer coefficient and the formal potential for ZnCl{sub 2} reduction were evaluated from cyclic voltammetry experiments. The nucleation process was analyzed by comparing the transients obtained with the known dimensionless (i/i{sub m}){sup 2} vs. t/t{sub m} response for instantaneous or progressive nucleation. The results show that the nucleation process and the number density of sites are dependent on ZnCl{sub 2} concentration. Scanning electron microscopy analysis of the deposits shows that the deposits are homogeneous and compact although a change in the morphology is observed as a function of ZnCl{sub 2} concentration. Evaluation of the corrosion resistance reveals the influence of the nucleation process on the subsequent corrosion resistance of the zinc deposits.

  14. Nanopore detection of DNA molecules in magnesium chloride solutions.

    PubMed

    Zhang, Yin; Liu, Lei; Sha, Jingjie; Ni, Zhonghua; Yi, Hong; Chen, Yunfei

    2013-01-01

    High translocation speed of a DNA strand through a nanopore is a major bottleneck for nanopore detection of DNA molecules. Here, we choose MgCl2 electrolyte as salt solution to control DNA mobility. Experimental results demonstrate that the duration time for straight state translocation events in 1 M MgCl2 solution is about 1.3 ms which is about three times longer than that for the same DNA in 1 M KCl solution. This is because Mg(2+) ions can effectively reduce the surface charge density of the negative DNA strands and then lead to the decrease of the DNA electrophoretic speed. It is also found that the Mg(2+) ions can induce the DNA molecules binding together and reduce the probability of straight DNA translocation events. The nanopore with small diameter can break off the bound DNA strands and increase the occurrence probability of straight DNA translocation events.

  15. The effect of GlycoPEGylation on the physical stability of human rFVIIa with increasing calcium chloride concentration.

    PubMed

    Plesner, Bitten; Westh, Peter; Nielsen, Anders D

    2011-06-01

    The effects of calcium chloride on the structural, kinetic and thermal stability of recombinant human factor VIIa (rFVIIa) were investigated using rFVIIa and two GlycoPEGylated recombinant human FVIIa derivatives, a linear 10 kDa PEG and a branched 40 kDa PEG, respectively. Three different CaCl(2) concentrations were used: 10mM, 35 mM and 100mM. The secondary structure and tertiary structure of rFVIIa at 25°C, measured by circular dichroism (CD), were maintained upon GlycoPEGylation as well as CaCl(2) content. In contrast, the thermal stability of the three rFVIIa compounds, measured by differential scanning calorimetry (DSC) and circular dichroism (CD), and aggregation behaviour, measured by light scattering (LS), were affected by the increasing calcium concentration. Increasing the CaCl(2) concentration from 10mM to 35 mM resulted in a decrease in the apparent unfolding temperature, T(m), of rFVIIa, whereas the concentration of CaCl(2) has to be raised to 100mM in order to see the same effect on the GlycoPEGylated rFVIIa compounds. The temperature of aggregation of rFVIIa, T(agg), increased as the CaCl(2) concentration increased from 35 mM to 100 mM, while T(agg) for the GlycoPEGylated rFVIIa compounds was practically independent of the CaCl(2) concentration. From the obtained results, it is concluded that GlycoPEGylation postpones the calcium induced thermal destabilisation of rFVIIa, and a much higher calcium concentration also postpones the thermally induced aggregation of rFVIIa. The thermally induced aggregation of the GlycoPEGylated rFVIIa compounds is unaffected by an increasing calcium chloride concentration.

  16. Spasmolytic effect of Petroselinum crispum (Parsley) on rat's ileum at different calcium chloride concentrations.

    PubMed

    Moazedi, A A; Mirzaie, D N; Seyyednejad, S M; Zadkarami, M R; Amirzargar, A

    2007-11-15

    Traditional herbal medicines such as Petroselinum crispum (Parsley) have been used for treatment of intestinal disorders in Iran. To date no pharmacological evidence for their effectiveness has been reported. The aim of this study was to examine the relaxant effect of hydroalcoholic extract of Petroselinum crispum on isolated adult male Wistar rat's ileum contraction by KCl 60 (mM). The extract was prepared from parsley seed with 80% ethanol. A portion of ileum was removed and placed in an organ bath containing Tyrode solution (37 degrees C, pH = 7.4) bubbled with air. From a resting tension of 1 g, isotonic Transducer and Harvard Universal Oscillograph were used for recording contraction of ileum after administration of 60 mM KCl. Various concentration of extract were added to the bath. This experiment showed that, the extract in a dose-dependent manner decreased the induced-KCl ileums contraction (n = 7, p < 0.001). Also adding extract before influence of KCl, cause reduced effect of KCl (n = 7, p < 0.001). In addition, the Tyrode solution without CaCl2 and high concentration of K+, various concentration of extract significantly (n = 7, p < 0.001) decreased the CaCl2-induced contraction. Therefore, it seems that the relaxation effect of extract alcoholic parsley seed on the contraction of ileum is performed by blocking of voltage-gated calcium channels.

  17. Solute rejection by porous glass membranes. I - Hyperfiltration of sodium chloride and urea feed solutions.

    NASA Technical Reports Server (NTRS)

    Ballou, E. V.; Wydeven, T.; Leban, M. I.

    1971-01-01

    Hyperfiltration of sodium chloride and urea was studied with porous glass membranes in closed-end capillary form, to determine the effect of pressure, temperature, and concentration variations, and lifetime rejection and flux characteristics. Rejection data for sodium chloride were consistent with the functioning of the porous glass as a low-capacity ion-exchange membrane.

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

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

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

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

    PubMed

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

    2015-09-01

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

  20. Individual effects of sodium, potassium, calcium, and magnesium chloride salts on Lactobacillus pentosus and Saccharomyces cerevisiae growth.

    PubMed

    Bautista-Gallego, J; Arroyo-López, F N; Durán-Quintana, M C; Garrido-Fernandez, A

    2008-07-01

    A quantitative investigation on the individual effects of sodium (NaCl), potassium (KCl), calcium (CaCl2), and magnesium (MgCl2) chloride salts against Lactobacillus pentosus and Saccharomyces cerevisiae, two representative microorganisms of table olives and other fermented vegetables, was carried out. In order to assess their potential activities, both the kinetic growth parameters and dose-response profiles in synthetic media (deMan Rogosa Sharpe broth medium and yeast-malt-peptone-glucose broth medium, respectively) were obtained and analyzed. Microbial growth was monitored via optical density measurements as a function of contact time in the presence of progressive chloride salt concentrations. Relative maximum specific growth rate and lag-phase period were modeled as a function of the chloride salt concentrations. Moreover, for each salt and microorganism tested, the noninhibitory concentrations and the MICs were estimated and compared. All chloride salts exerted a significant antimicrobial effect on the growth cycle; particularly, CaCl2 showed a similar effect to NaCl, while KCl and MgCl2 were progressively less inhibitory. Microbial susceptibility and resistance were found to be nonlinearly dose related.

  1. Electrochemical Evaluation of Stainless Steels in Acidified Sodium Chloride Solutions

    NASA Technical Reports Server (NTRS)

    Calle, L. M.; MacDowell, L. G.; Vinje, R. D.

    2004-01-01

    This paper presents the results of an investigation in which several 300-series stainless steels (SS): AISI S30403 SS (UNS S30403), AISI 316L SS (UNS S31603), and AISI 317L SS (LINS S31703), as well as highly-alloyed: SS 254-SMO (UNS S32154), AL-6XN (N08367) and AL29-4C (UNS S44735), were evaluated using DC electrochemical techniques in three different electrolyte solutions. The solutions consisted of neutral 3.55% NaCl, 3.55% NaCl in 0.1N HCl, and 3.55% NaCl in 1.0N HCl. These solutions were chosen to simulate environments that are less, similar, and more aggressive, respectively, than the conditions at the Space Shuttle launch pads. The electrochemical test results were compared to atmospheric exposure data and evaluated for their ability to predict the long-term corrosion performance of the subject alloys. The electrochemical measurements for the six alloys indicated that the higher-alloyed SS 254-SMO, AL29-4C, and AL-6XN exhibited significantly higher resistance to localized corrosion than the 300-series SS. There was a correlation between the corrosion performance of the alloys during a two-year atmospheric exposure and the corrosion rates calculated from electrochemical (polarization resistance) measurements.

  2. Interactive role of nitric oxide and calcium chloride in enhancing tolerance to salt stress.

    PubMed

    Khan, M Nasir; Siddiqui, Manzer H; Mohammad, Firoz; Naeem, M

    2012-12-01

    Nitric oxide (NO), a small diffusible, ubiquitous bioactive molecule, acts as prooxidant as well as antioxidant, and also regulates remarkable spectrum of plant cellular mechanisms. The present work was undertaken to investigate the role of nitric oxide donor sodium nitroprusside (SNP) and/or calcium chloride (CaCl(2)) in the tolerance of excised mustard leaves to salt stress. After 24h, salt stressed leaves treated with SNP and/or CaCl(2), showed an improvement in the activities of carbonic anhydrase (CA) and nitrate reductase (NR), and leaf chlorophyll (Chl) content, leaf relative water content (LRWC) and leaf ion concentration as compared with the leaves treated with NaCl only. Salinity stress caused a significant increase in H(2)O(2) content and membrane damage which is witnessed by enhanced levels of thiobarbituric acid reactive substances (TBARS) and electrolyte leakage. By contrast, such increases were blocked by the application of 0.2mM SNP and 10mM CaCl(2) to salt stressed leaves. Application of SNP and/or CaCl(2) alleviated NaCl stress by enhancing the activities of antioxidative enzymes viz. superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), ascorbate peroxidase (APX) and glutathione reductase (GR) and by enhancing proline (Pro) and glycinebetaine (GB) accumulation with a concomitant decrease in H(2)O(2) content, TBARS and electrolyte leakage, which is manifested in the tolerance of plants to salinity stress. Moreover, application of SNP with CaCl(2) was more effective to reduce the detrimental effects of NaCl stress on excised mustard leaves. In addition to this, ameliorating effect of SNP was not effective in presence of NO scavenger cPTIO [2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide]. To put all these in a nut shell, the results advocate that SNP in association with CaCl(2) plays a role in enhancing the tolerance of plants to salt stress by improving antioxidative defence system, osmolyte accumulation and ionic

  3. The calcium chloride-induced rodent model of abdominal aortic aneurysm.

    PubMed

    Wang, Yutang; Krishna, Smriti; Golledge, Jonathan

    2013-01-01

    Abdominal aortic aneurysm (AAA) affects ∼5% men aged over 65 years and is an important cause of death in this population. Research into AAA pathogenesis has been fuelled by the need to identify new diagnostic biomarkers and therapeutic targets for this disease. One animal model of AAA involves peri-vascular application of calcium chloride (CaCl(2)) onto the infra-renal aorta of mice and rats to induce extracellular matrix remodelling. Twenty-three studies assessing CaCl(2)-induced AAA and six studies assessing AAA induced by a modified CaCl(2) method were identified. In the current report the preparation and pathological features of this AAA model are discussed. We also compared this animal model to human AAA. CaCl(2)-induced AAA shows the following pathological characteristics typically found in human AAA: calcification, inflammatory cell infiltration, oxidative stress, neovascularisation, elastin degradation and vascular smooth muscle cell apoptosis. A number of mechanisms involved in CaCl(2)-induced AAA have been identified which may be relevant to the pathogenesis of human AAA. Key molecules include c-Jun N-terminal kinase, peroxisome proliferator-activated receptor-γ, chemokine (C-C motif) receptor 2, group x secretory phospholipase A2 and plasminogen. CaCl(2)-induced AAA does not display aortic thrombus, atherosclerosis and rupture which are classical features of human AAA. Advantages of the CaCl(2)-induced AAA technique include (1) it can be applied to wild type mice making assessment of transgenic rodent models more straight forward and rapid; and (2) CaCl(2)-induced AAAs are usually developed in the infra-renal abdominal aorta, which is the most common location of human AAA. Currently findings obtained from the CaCl(2)-induced AAA model or other animal models of AAA have not been translated into the human situation. It is hoped that this deficiency will be corrected over the next decade with a number of clinical trials currently examining novel

  4. Solid state and solution 43Ca NMR of calcium peroxides involved in the disproportionation of hydrogen peroxide by calcium hydroxide.

    PubMed

    Trokiner, Arlette; Bessière, Aurélie; Thouvenot, René; Hau, Damien; Marko, Jean; Nardello, Véronique; Pierlot, Christel; Aubry, Jean-Marie

    2004-06-01

    In order to get some insight into the mechanism of the disproportionation of hydrogen peroxide catalyzed by calcium hydroxide, 43Ca NMR spectra of enriched samples of calcium peroxides and of their precursors have been studied in both solution and solid state. This study demonstrates that no well-defined peroxidized calcium species are formed in solution, showing that the catalytic role of calcium is likely restricted to the solid state. Most of the calcium compounds that could be involved in the catalytic process have been investigated with solid state NMR. The shift and quadrupolar parameters of Ca(OH)2, CaO2.8H2O and CaO2.2H2O2 are reported for the first time. These parameters are different enough to allow the quantitative analysis of a complex mixture of these compounds by NMR.

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

    NASA Astrophysics Data System (ADS)

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

    2016-08-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2016-08-01

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

  7. Formation of liquid water at low temperatures via the deliquescence of calcium chloride: Implications for Antarctica and Mars

    NASA Astrophysics Data System (ADS)

    Gough, R. V.; Chevrier, V. F.; Tolbert, M. A.

    2016-10-01

    There is significant interest in the potential existence of even small amounts of liquid brine on current Mars. It has been proposed that aqueous solutions could form on Mars via the deliquescence of hygroscopic salts in contact with atmospheric water vapor, and these hygroscopic salts have recently been detected in recurring slope linae (RSL). While past work has largely focused on perchlorate species, another Mars-relevant salt that has a low eutectic temperature and may be deliquescent is calcium chloride, CaCl2. This salt may be linked to RSL formation on Mars, and deliquescence of CaCl2 is also known to be responsible for the only terrestrial RSL analog features known thus far: water tracks in the McMurdo Dry Valleys. Here we use Raman microscopy to monitor the low-temperature (223-273 K) deliquescence (solid to aqueous phase transition) and efflorescence (aqueous to solid phase transition) of two hydration states of CaCl2, the dihydrate and the hexahydrate. We find the deliquescence relative humidity (DRH) decreases with decreasing hydration state and with increasing temperature. Average DRH values over the temperature range studied are 15.8±3.5% RH for the dihydrate and 63.3±12.5% RH for the hexahydrate, making this salt at least as deliquescent as many perchlorate salts. A remarkable property of CaCl2 is its ability to persist as metastable, supersaturated brine. Once an aqueous solution was formed, efflorescence (recrystallization) of the liquid did not occur until single-digit RH values were reached (3.9±2.4% RH on average). We show that temperature and relative humidity conditions in the martian subsurface are sufficient to allow deliquescence of CaCl2, and the resulting brines may persist for over half of a martian sol. Therefore, this salt could play a role in RSL formation, the martian water cycle, and have implications for the potential habitability of Mars.

  8. Calcium.

    PubMed

    Williams, Robert J P

    2002-01-01

    This chapter describes the chemical and biological value of the calcium ion. In calcium chemistry, our main interest is in equilibria within static, nonflowing systems. Hence, we examined the way calcium formed precipitates and complex ions in solution. We observed thereafter its uses by humankind in a vast number of materials such as minerals, e.g., marble, concrete, mortars, which parallel the biological use in shells and bones. In complex formation, we noted that many combinations were of anion interaction with calcium for example in the uses of detergents and medicines. The rates of exchange of calcium from bound states were noted but they had little application. Calcium ions do not act as catalysts of organic reactions. In biological systems, interest is in the above chemistry, but extends to the fact that Ca2+ ions can carry information by flowing in one solution or from one solution to another through membranes. Hence, we became interested in the details of rates of calcium exchange. The fast exchange of this divalent ion from most organic binding sites has allowed it to develop as the dominant second messenger. Now the flow can be examined in vitro as calcium binds particular isolated proteins, which it activates as seen in physical mechanical changes or chemical changes and this piece-by-piece study of cells is common. Here, however, we have chosen to stress the whole circuit of Ca2+ action indicating that the cell is organized both at a basal and an activated state kinetic level by the steady state flow of the ion (see Fig. 11). Different time constants of exchange utilizing very similar binding constants lead to: 1) fast responses as in the muscle of an animal; or 2) slower change as in differentiation of an egg or seed. Many other changes of state may relate to Ca2+ steady-state levels of flow in the circuitry and here we point to two: 1) dormancy in reptiles and animals; and 2) sporulation in both bacteria and lower plants. In the other chapters of

  9. Raman spectroscopic study of sodium chloride water solutions

    NASA Astrophysics Data System (ADS)

    Furić, K.; Ciglenečki, I.; Ćosović, B.

    2000-09-01

    The Raman spectra of NaCl water solutions have been studied in the concentration range between 0 and 3.3 M using a difference technique. The temperature dependence of the spectral profiles observed for the O-H stretching in the high frequency region (between 2500 and 4000 cm -1) was also investigated in the narrow interval around a room temperature. Although the considered bandshape is not of a simple kind, the measured Id/ I0 ratio plotted versus NaCl concentration and temperature fits a straight line in both diagrams very satisfactorily. The linear dependence of Id/ I0 versus NaCl molarity was checked in the study of natural seawater samples for which discrepancies were found. These deviations were attributed to other organic and inorganic dissolved components in the seawater.

  10. Transmittance of distilled water and sodium-chloride-water solutions

    SciTech Connect

    Kanayama, K.; Baba, H.

    1988-05-01

    The spectral transmittance of pure water and salt water solutions of various concentrations, which are important for the thermal calculation of a solar pond, is measured experimentally for specimen thickness of 1 to 100 mm by means of an autorecording spectro-radiometer inside an air-conditioned room. On the basis of the measured spectral transmittance, the total transmittance of pure and salty waters to 3 m of water depth is calculated as a ratio of the total radiation energy over all wavelengths arriving at any depth from the water surface of the solar pond to the solar radiation incident upon the water surface with various air masses. According to Nielsens' four-partition method, the effective absorption coefficient is calculated for each wavelength band. Lastly, the transmission properties obtained for pure water, i.e., spectral and total transmittances, absorption wavelength band, and effective absorption coefficient, are compared with past results, and those for salty water with various concentrations are compiled as basic data for the use of solar energy by a solar pond.

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

    PubMed

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

    2010-02-01

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

  12. Optical absorption and heating rate dependent glass transition in vanadyl doped calcium oxy-chloride borate glasses

    NASA Astrophysics Data System (ADS)

    Dahiya, M. S.; Khasa, S.; Agarwal, A.

    2015-04-01

    Some important results pertaining to optical and thermal properties of vanadyl doped oxy-halide glasses in the chemical composition CaCl2-CaO-B2O3 are discussed. These glasses have been prepared by conventional melt quench technique. From X-ray diffraction (XRD) profiles the amorphous nature of the doped glasses has been confirmed. The electronic polarizability is calculated and found to increase with increase in chloride content. The optical absorption spectra have been recorded in the frequency range of 200-3200 nm. Recorded spectra are analyzed to evaluate cut-off wavelength (λcut-off), optical band gap (Eg), band tailing (B), Urbach energy (ΔE) and refractive index (n). Thermal analysis has been carried out for the prepared glasses at three different heating rates viz. 5, 10 and 20 °C/min. The glass transition temperature (Tg) along with thermal activation energy (Ea) corresponding to each heating rate are evaluated from differential scanning calorimetry (DSC) thermographs. It is found that Ea decrease and Tg increase with increase in heating rate. The variation in Tg is also observed with the substitution of calcium chloride in place of calcium oxide. The increasing and higher values of Ea suggest that prepared glasses have good thermal stability. Variation in Tg and Eg suggests that Cl- anions enter into the voids of borate network at low concentrations (<5.0%) and contribute to the network formation at high concentration (>5.0%).

  13. Mixed solutions of silver cation and chloride anion in acetonitrile: voltammetric and EQCM study.

    PubMed

    Skompska, Magdalena; Vorotyntsev, Mikhail A; Rajchowska, Aleksandra; Levin, Oleg V

    2010-09-21

    Electrochemical behavior of Pt and Au electrodes in acetonitrile solutions at different concentration ratios of Cl(-) and Ag(+) ions was studied by cyclic voltammetry and electrochemical quartz crystal microbalance (EQCM). The composition of the mixed silver chloride solutions, i.e. the amount of each component of the system (solid AgCl and solute species: Ag(+), Cl(-), AgCl(2)(-)), is governed by the solubility product of AgCl and the stability constant of AgCl(2)(-)complex and depends strongly on the ratio of the total concentrations of chloride and silver ions. In this work we analyze in detail the influence of the Cl(-)/Ag(+) concentration ratio on the value of equilibrium electrode potential and the shape of cyclic voltammograms. We explain the complicated shapes of the experimental curves observed at different concentration ranges, propose the mechanisms of the processes occurring at the electrode and substantiate them by EQCM data.

  14. Behavior of antimony(III) during copper electrowinning in chloride solutions

    SciTech Connect

    Lin, H.K.; Wu, X.

    1996-04-01

    Contamination of cathodic copper by Sb during electrowinning in chloride solutions is a surface phenomenon. A digitized scanning electron microscopy (SEM) micrograph indicates that the Sb is concentrated on the surface /of the cathode. Energy-dispersive X-ray (EDX) analysis reveals that the Sb-containing layer is a complex salt of Cu, Sb, Cl, and O. Electrochemical measurements show that the adsorption of Sb or Cu species decreases with the increase of acidity of the solution when the solution contains antimony chloride or cuprous chloride. The adsorption increases with the increase of the acidity when the solution contains both Sb and Cu. The discharge of cuprous ions in the adsorbed complex salt releases antimonious ions and then forms a new layer of the complex salt with cuprous ions from the solution. This newly formed complex salt is readsorbed on the surface of the cathode. Thus, Sb concentrates on the surface of the cathode instead of being evenly distributed throughout the copper product. This suggested mechanism also explains the fact that the presence of Sb in the electrolyte enhances the electrodeposition of Cu.

  15. Stereocontrolled synthesis of rosuvastatin calcium via iodine chloride-induced intramolecular cyclization.

    PubMed

    Xiong, Fangjun; Wang, Haifeng; Yan, Lingjie; Han, Sheng; Tao, Yuan; Wu, Yan; Chen, Fener

    2016-01-28

    A novel, stereoselective approach towards rosuvastatin calcium from the known (S)-homoallylic alcohol has been developed. The synthesis is highlighted by a regio- and stereocontrolled ICl-induced intramolecular cyclization of chiral homoallylic carbonate to deliver the C6-formyl statin side chain with a syn-1,3-diol moiety. An improved synthesis of the rosuvastatin pyrimidine core moiety is also included. Moreover, this methodology is useful in the asymmetric synthesis of structural variants of statins such as pitavastatin calcium and atorvastatin calcium and their related analogs.

  16. Effects of dietary ammonium chloride and variations in calcium to phosphorus ratio on silica urolithiasis in sheep.

    PubMed

    Stewart, S R; Emerick, R J; Pritchard, R H

    1991-05-01

    Ammonium chloride was added to diets varying in Ca content to evaluate its potential in preventing silica urolith formation in sheep. A 2 x 2 factorial experiment involved wether lambs with ad libitum access to a diet of 50% grass hay and 50% ground oats plus supplement. The basal diet contained on a DM basis 3.3% SiO2, .31% Ca, .22% P, 11.6% CP, and 26% ADF. Treatments (38 to 39 lambs/treatment) consisted of a control (C), limestone to increase dietary calcium to .6% (L), 1% ammonium chloride (A), and L + A (LA). After a 118-d experimental period, siliceous kidney deposits were found only in C and L, with silica making up 93% to 95% of the urolithic ash. Urolith incidences were 13% (C) and 18% (L), respectively. The lack of urolith development in lambs fed A and LA (ammonium chloride effect, P less than .01) and a trend toward a lower urolith incidence in C vs L (P less than .02) support the hypothesis that acid-forming effects of the diet and a reduction in the dietary Ca to P ratio reduce silica urolith formation.

  17. Synthesis and characterization of cadmium-calcium hydroxyapatite solid solutions

    NASA Astrophysics Data System (ADS)

    Zhao, Xin; Zhu, Yi-nian; Dai, Liu-qin

    2014-06-01

    A series of cadmium-calcium hydroxyapatite solid solutions was prepared by an aqueous precipitation method. By various means, the characterizations confirmed the formation of continuous solid solutions over all ranges of Cd/(Cd+Ca) atomic ratio. In the results, both lattice parameters a and c display slight deviations from Vegard's rule when the Cd/(Cd+Ca) atomic ratio is greater than 0.6. The particles change from smaller acicular to larger hexagonal columnar crystals as the Cd/(Cd+Ca) atomic ratio increases from 0-0.60 to 0.60-1.00. The area of the phosphate peak for symmetric P-O stretching decreases with the increase in Cd/(Cd+Ca) atomic ratio, and the peak disappears when the Cd/(Cd+Ca) atomic ratio is greater than 0.6; the two phosphate peaks of P-O stretching gradually merge together for the Cd/(Cd+Ca) atomic ratio near 0.60. These variations can be explained by a slight tendency of larger Cd ions to occupy M(2) sites and smaller Ca ions to prefer M(1) sites in the structure.

  18. Effect of post-harvest calcium chloride dip treatment and gamma irradiation on storage quality and shelf-life extension of Red delicious apple.

    PubMed

    Hussain, P R; Meena, R S; Dar, M A; Wani, A M

    2012-08-01

    Freshly harvested Red delicious apples were dipped in calcium chloride solution of varying concentrations (0.5-2.0% w/v) for 1 h prior to irradiation at dose level of 0.4 kGy. Fruits after radiation treatment were stored at 2 ± 1°C, RH 90% and evaluated at intervals of 30 days for various quality parameters. Results revealed significant (p ≤ 0.05) retention in firmness, juice yield and ascorbic acid content in samples treated with combination of calcium chloride at 2.0% w/v and gamma irradiation (0.4 kGy) during storage. Water soluble pectin was inversely correlated with firmness (r = 0.88) and was significantly (p ≤ 0.05) lower in samples subjected to combination treatment of 2.0% w/v CaCl2 and 0.4 kGy irradiation throughout the storage. The combination treatment of 2.0% CaCl2 and 0.4 kGy irradiation gave about 4.3 log reduction in yeast and mold count of apple samples. Results of the post refrigeration weight loss, firmness and overall acceptability revealed that combination treatment was helpful in extending the shelf-life of Red Delicious apples by around 20-25 days at 17 ± 2°C, RH 75% following 90 days of refrigeration. PMID:23904650

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

    SciTech Connect

    Day, S D; Rebak, R B

    2004-11-22

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

  20. Exploring time of death from potassium, sodium, chloride, glucose & calcium analysis of postmortem synovial fluid in semi arid climate.

    PubMed

    Siddhamsetty, Arun K; Verma, Satish K; Kohli, Anil; Verma, Aditi; Puri, Dinesh; Singh, Archana

    2014-11-01

    Estimation of time of death (TOD) with fair accuracy from postmortem changes still remains an important but difficult task to be performed by every autopsy surgeon under different climatic conditions. The environment plays an important role in the process of decomposition and thereby affecting the levels of electrolytes and other biochemical parameters in the postmortem samples. Since, there is limited information available on the levels of these biochemical parameters from semi arid environment, the present study was aimed to explore time of death by analyzing electrolyte, glucose and calcium levels of postmortem synovial fluid collected from samples under such climatic conditions. The synovial fluid samples from two hundred and ten bodies brought to University College of Medical Sciences and associated Guru Teg Bahadur Hospital Delhi for medico-legal postmortem examination, during the period of November 2010 to April 2012, were analyzed for potassium, sodium, chloride, glucose and calcium. Univariate regression analysis of electrolyte concentrations of synovial fluid showed significant positive relationship between time of death and potassium (r = 0.840, p = 0.000). However, there was negative relationship between time of death and sodium (r = -0.175, p = 0.011) & glucose (r = -0.427, p = 0.000) and no significant relationship was found between time of death and calcium (r = 0.099, p = 0.152) & chloride (r = 0.082, p = 0.24) among the samples analyzed.

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

    NASA Astrophysics Data System (ADS)

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

    2016-10-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2016-08-01

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

  3. Calcium-activated chloride channels in bovine pulmonary artery endothelial cells.

    PubMed Central

    Nilius, B; Prenen, J; Szücs, G; Wei, L; Tanzi, F; Voets, T; Droogmans, G

    1997-01-01

    1. We characterized Ca(2+)-activated Cl- currents in calf pulmonary artery endothelial (CPAE) cells by using a combined patch clamp and fura-2 microfluorescence technique to simultaneously measure ionic currents and the intracellular Ca2+ concentration, [Ca2+]i. 2. Various procedures that increased [Ca2+]i, such as stimulation with ATP or ionomycin, or loading the cells with Ca2+ via the patch pipette, activated a strongly outwardly rectifying current with a reversal potential close to the Cl- equilibrium potential. Changing the extracellular Cl- concentration shifted this reversal potential as predicted for a Cl- current. Buffering Ca2+ rises with BAPTA prevented ATP from activating the current. 3. Ca(2+)-activated Cl- currents could be distinguished from volume-activated Cl- currents, which were sometimes coactivated in the same cell. The latter showed much less outward rectification, their activation was voltage independent, and they could be inhibited by exposing the cells to hypertonic solutions. 4. The permeability ratio for the Ca(2+)-activated conductance of the anions iodide:chloride: gluconate was 1.71 +/- 0.06:1:0.39 +/- 0.03 (n = 12). 5. This Ca(2+)-activated Cl- current, ICl, Ca, inactivated rapidly at negative potentials and activated slowly at positive potentials. Outward tail currents were slowly decaying, while inward tail currents decayed much faster. 6. 4,4'-Diisothiocyanatostilbene-2,2'-disulphonic-acid (DIDS) and niflumic acid inhibited Icl,Ca in a voltage-dependent manner, i.e. they exerted a more potent block at positive potentials. The block by N-phenylanthracilic acid (NPA), 5-nitro-2-(3-phenylpropylamino)-benzoate (NPPB) and tamoxifen was voltage independent. Niflumic acid and tamoxifen were the most potent blockers. 7. The single-channel conductance was 7.9 +/- 0.7 pS (n = 15) at 300 mM extracellular Cl-. The channel open probability was high at positive potentials, but very small at negative potentials. 8. It is concluded that [Ca2+]i

  4. Calcium Binding to Amino Acids and Small Glycine Peptides in Aqueous Solution: Toward Peptide Design for Better Calcium Bioavailability.

    PubMed

    Tang, Ning; Skibsted, Leif H

    2016-06-01

    Deprotonation of amino acids as occurs during transfer from stomach to intestines during food digestion was found by comparison of complex formation constants as determined electrochemically for increasing pH to increase calcium binding (i) by a factor of around 6 for the neutral amino acids, (ii) by a factor of around 4 for anions of the acidic amino acids aspartic and glutamic acid, and (iii) by a factor of around 5.5 for basic amino acids. Optimized structures of the 1:1 complexes and ΔHbinding for calcium binding as calculated by density functional theory (DFT) confirmed in all complexes a stronger calcium binding and shorter calcium-oxygen bond length in the deprotonated form. In addition, the stronger calcium binding was also accompanied by a binding site shift from carboxylate binding to chelation by α-amino group and carboxylate oxygen for leucine, aspartate, glutamate, alanine, and asparagine. For binary amino acid mixtures, the calcium-binding constant was close to the predicted geometric mean of the individual amino acid binding constants indicating separate binding of calcium to two amino acids when present together in solution. At high pH, corresponding to conditions for calcium absorption, the binding affinity increased in the order Lys < Arg < Cys < Gln < Gly ∼ Ala < Asn < His < Leu < Glu< Asp. In a series of glycine peptides, calcium-binding affinity was found to increase in the order Gly-Leu ∼ Gly-Gly < Ala-Gly < Gly-His ∼ Gly-Lys-Gly < Glu-Cys-Gly < Gly-Glu, an ordering confirmed by DFT calculations for the dipeptides and which also accounted for large synergistic effects in calcium binding for up to 6 kJ/mol when compared to the corresponding amino acid mixtures.

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

    NASA Technical Reports Server (NTRS)

    Wydeven, T.; Leban, M.

    1973-01-01

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

  6. Electrochemical cell with calcium anode

    DOEpatents

    Cooper, John F.; Hosmer, Pamela K.; Kelly, Benjamin E.

    1979-01-01

    An electrochemical cell comprising a calcium anode and a suitable cathode in an alkaline electrolyte consisting essentially of an aqueous solution of an hydroxide and a chloride. Specifically disclosed is a mechanically rechargeable calcium/air fuel cell with an aqueous NaOH/NaCl electrolyte.

  7. Primary stage of the reaction between ozone and chloride ions in aqueous solution: Can chloride ion oxidation by ozone proceed via electron transfer mechanism?

    NASA Astrophysics Data System (ADS)

    Levanov, A. V.; Antipenko, E. E.; Lunin, V. V.

    2012-04-01

    It is found that chloride-ion oxidation by ozone via electron transfer mechanism does not occur due to its extremely high endoergicity and negligibly low rate. It is concluded that all processes supposedly associated with this reaction, particularly ozone decomposition in sodium chloride solution initiated by Cl· atoms, do not take place either. It is shown that experimental data on the products and kinetic regularities of the interaction of O3 with Cl- contradict the assumption that the electron transfer reaction is its primary stage. In fact, chloride-ion oxidation by ozone proceeds via the mechanism of oxygen atom transfer. It is noted that in order to estimate the possibility of using an ozonated physiological saline in medicine, the formation of chloride-ion oxidation products and ozonation byproducts must be taken into account.

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

    PubMed

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

    2015-01-01

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

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

    PubMed

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

    2015-11-01

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

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

    PubMed

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

    2015-11-01

    The experimental investigation of chloride ion oxidation under the action of ozone and ultraviolet radiation with wavelength 254 nm in the bulk of acid aqueous solution at pH 0-2 has been performed. Processes of chloride oxidation in these conditions are the same as the chemical reactions in the system O3 - OH - Cl(-)(aq). Despite its importance in the environment and for ozone-based water treatment, this reaction system has not been previously investigated in the bulk solution. The end products are chlorate ion ClO3(-) and molecular chlorine Cl2. The ions of trivalent iron have been shown to be catalysts of Cl(-) oxidation. The dependencies of the products formation rates on the concentrations of O3 and H(+) have been studied. The chemical mechanism of Cl(-) oxidation and Cl2 emission and ClO3(-) formation has been proposed. According to the mechanism, the dominant primary process of chloride oxidation represents the complex interaction with hydroxyl radical OH with the formation of Cl2(-) anion-radical intermediate. OH radical is generated on ozone photolysis in aqueous solution. The key subsequent processes are the reactions Cl2(-) + O3 → ClO + O2 + Cl(-) and ClO + H2O2 → HOCl + HO2. Until the present time, they have not been taken into consideration on mechanistic description and modelling of Cl(-) oxidation. The final products are formed via the reactions 2ClO → Cl2O2, Cl2O2 + H2O → 2H(+) + Cl(-) + ClO3(-) and HOCl + H(+) + Cl(-) ⇄ H2O + Cl2. Some portion of chloride is oxidized directly by O3 molecule with the formation of molecular chlorine in the end. PMID:26077317

  11. Preparation and Characterization of a Calcium Phosphate Ceramic for the Immobilization of Chloride-containing Intermediate Level Waste

    SciTech Connect

    Metcalfe, Brian; Donald, Ian W.; Scheele, Randall D.; Strachan, Denis M.

    2003-12-01

    Attention has recently been given to the immobilization of special categories of radioactive wastes, some of which contain high concentrations of actinide chlorides. Although vitrification in phosphate glass has been proposed, this was rejected because of the high losses of chloride. On the basis of non-radioactive and, more recently, radioactive studies, we have shown that calcium phosphate is an effective host for immobilizing the chloride constituents [1]. In this instance, the chlorine is retained as chloride, rather than evolved as a chlorine-bearing gas. The immobilized product is in the form of a free-flowing, non-hygroscopic powder, in which the chlorides are chemically combined within the mineral phases chlorapatite [Ca5(PO4)3Cl] and spodiosite [Ca2(PO4)Cl]. Data from studies on non-radioactive simulated waste consisting of a mixture of CaCl2 and SmCl3, and radioactive simulated waste composed of CaCl2 with PuCl3 or PuCl3 and AmCl3, are presented and compared. The XRD data confirm the presence of chlorapatite and spodiosite in the non-radioactive and radioactive materials. The durability of all specimens was measured with a modified MCC-1 test. Releases of Cl after 28 days were 1.6 x 10-3 g m-2 for the non-radioactive specimens and 7 x 10-3 g m-2 for the Pu-bearing specimens. Releases of Ca after 28 days were 0.3 x 10-3 and 2.0 x 10-3 g m-2 for the non-radioactive composition and the Pu composition, respectively, whilst release of Pu from the radioactive specimens was lower for the mixed Pu/Am specimen at 1.2 x 10-5g m-2. The release of Am from the mixed Pu/Am composition was exceptionally low at 2.4 x 10-7 g m-2. Overall, the release rate data suggest that the ceramics dissolve congruently, followed by precipitation of Sm, Pu and Am as less soluble phases, possibly oxides or phosphates. The differences in behaviour noted between non-radioactive and radioactive specimens are interpreted in terms of the crystal chemistry of the individual systems.

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

    SciTech Connect

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

    2003-06-24

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

  13. Effect of human blood addition on dendritic growth of cupric chloride crystals in aqueous solutions

    NASA Astrophysics Data System (ADS)

    Shibata, Takashi; Shirasaka, Ryukoh; Ogawa, Tomoya; Takakuwa, Yuichi; Furiya, Kei; Tanaka, Akemi; Kogure, Mitsuko; Obata, Hiroshi

    1994-09-01

    An extremely small amount of 0.2% or less (volume ratio) of human blood influences the dendritic growth of cupric chloride crystals in an aqueous solution, with some researchers claiming that the growth depends upon any disease the blood donor might be carrying. This is a very surprising phenomenon. Dendrites grown in a blood-added CuCl 2 ⋯ 2H 2O solution were classified into groups of blue and green by color; all the dendrites grown in an aqueous solution without blood were a single color: blue. A very clear difference between the blue and green dendrites was obtained by thermo-gravimetry/differential thermal analysis, because of positional and numerical difference of water molecules in the cupric chloride crystals. Many tiny granules were observed on facets of the dendrites grown in the blood-added aqueous solutions. Surfaces of the dendrites were surveyed by an electron probe X-ray micro-analyzer and by an X-ray photo-electron spectroscope, and chemical shifts of copper, chlorine, nitrogen, carbon and oxygen signals were found on those dendrites grown in blood-added CuCl 2 ⋯ 2H 2O solutions. This evidence suggests that components of blood including amino acid, peptide and/or protein or some composition of them were chemisorbed on the dendrite surfaces.

  14. Calcium buffer solutions and how to make them: a do it yourself guide.

    PubMed

    McGuigan, J A; Lüthi, D; Buri, A

    1991-11-01

    In measurements of the intracellular free calcium concentration ([Ca2+]) using either microelectrodes or fluorescent probes, calibration is normally carried out in EGTA calcium buffer solutions. In the first part of the article the general properties of calcium buffer solutions are discussed, the equations used to calculate the apparent calcium binding constant (Kapp) are derived, and the difficulties in the calculation are discussed. The effects of the purity of EGTA as well as the influence of calcium contamination on the buffer solutions are explained. Because of the difficulties in calculating Kapp, and the importance of EGTA purity and calcium contamination, it is suggested that it is easier to measure all three under the appropriate experimental conditions using the method of Bers (1982). In the second part a do-it-yourself guide to the preparation of EGTA calcium buffer solutions is given. An experimental example is provided using the Bers method to measure purity, contamination, and Kapp. It is concluded that unless all three factors are known it is not possible to prepare accurate EGTA calcium buffer solutions.

  15. Antisense oligodeoxynucleotides to the cystic fibrosis transmembrane conductance regulator inhibit cAMP-activated but not calcium-activated chloride currents.

    PubMed Central

    Wagner, J A; McDonald, T V; Nghiem, P T; Lowe, A W; Schulman, H; Gruenert, D C; Stryer, L; Gardner, P

    1992-01-01

    Phosphorylation of the cystic fibrosis transmembrane conductance regulator (CFTR) by cAMP-dependent protein kinase leads to chloride flux in epithelial cells. Is CFTR also required for the calcium-dependent activation of chloride channels? We used antisense oligodeoxynucleotides to CFTR to reduce the expression of CFTR in colonic and tracheal epithelial cells. The antisense oligomers were a pair of adjacent 18-mers complementary to nucleotides 1-18 and 19-36 of CFTR mRNA. Sense and misantisense oligomers served as controls. A 48-h antisense treatment reduced the expression of CFTR protein as assayed by immunoprecipitation and autoradiography to 26% of the level in sense-treated T84 cells. Whole-cell patch clamp revealed that a 48-h antisense treatment of T84 and 56FHTE-8o- fetal tracheal epithelial cells reduced the cAMP-activated chloride current to approximately 10% of that in sense-treated cells. The half-life of functional CFTR is less than 24 h in these cells. In contrast, the calcium-activated chloride current was not affected by antisense treatment. Hence, the cAMP and calcium pathways are separate. CFTR is required for the cAMP pathway but not for the calcium pathway. Images PMID:1379720

  16. Functional expression of the TMEM16 family of calcium-activated chloride channels in airway smooth muscle

    PubMed Central

    Remy, Kenneth E.; Danielsson, Jennifer; Funayama, Hiromi; Fu, Xiao Wen; Chang, Herng-Yu Sucie; Yim, Peter; Xu, Dingbang; Emala, Charles W.

    2013-01-01

    Airway smooth muscle hyperresponsiveness is a key component in the pathophysiology of asthma. Although calcium-activated chloride channel (CaCC) flux has been described in many cell types, including human airway smooth muscle (HASM), the true molecular identity of the channels responsible for this chloride conductance remains controversial. Recently, a new family of proteins thought to represent the true CaCCs was identified as the TMEM16 family. This led us to question whether members of this family are functionally expressed in native and cultured HASM. We further questioned whether expression of these channels contributes to the contractile function of HASM. We identified the mRNA expression of eight members of the TMEM16 family in HASM cells and show immunohistochemical evidence of TMEM16A in both cultured and native HASM. Functionally, we demonstrate that the classic chloride channel inhibitor, 5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB), inhibited halide flux in cultured HASM cells. Moreover, HASM cells displayed classical electrophysiological properties of CaCCs during whole cell electrophysiological recordings, which were blocked by using an antibody selective for TMEM16A. Furthermore, two distinct TMEM16A antagonists (tannic acid and benzbromarone) impaired a substance P-induced contraction in isolated guinea pig tracheal rings. These findings demonstrate that multiple members of this recently described family of CaCCs are expressed in HASM cells, they display classic electrophysiological properties of CaCCs, and they modulate contractile tone in airway smooth muscle. The TMEM16 family may provide a novel therapeutic target for limiting airway constriction in asthma. PMID:23997176

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

    PubMed

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

    2016-01-01

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

  18. Increased strontium uptake in trabecular bone of ovariectomized calcium-deficient rats treated with strontium ranelate or strontium chloride.

    PubMed

    Pemmer, Bernhard; Hofstaetter, Jochen G; Meirer, Florian; Smolek, Stephan; Wobrauschek, Peter; Simon, Rolf; Fuchs, Robyn K; Allen, Matthew R; Condon, Keith W; Reinwald, Susan; Phipps, Roger J; Burr, David B; Paschalis, Eleftherios P; Klaushofer, Klaus; Streli, Christina; Roschger, Paul

    2011-11-01

    Based on clinical trials showing the efficacy to reduce vertebral and non-vertebral fractures, strontium ranelate (SrR) has been approved in several countries for the treatment of postmenopausal osteoporosis. Hence, it is of special clinical interest to elucidate how the Sr uptake is influenced by dietary Ca deficiency as well as by the formula of Sr administration, SrR versus strontium chloride (SrCl(2)). Three-month-old ovariectomized rats were treated for 90 days with doses of 25 mg kg(-1) d(-1) and 150 mg kg(-1) d(-1) of SrR or SrCl(2) at low (0.1% Ca) or normal (1.19% Ca) Ca diet. Vertebral bone tissue was analysed by confocal synchrotron-radiation-induced micro X-ray fluorescence and by backscattered electron imaging. Principal component analysis and k-means clustering of the acquired elemental maps of Ca and Sr revealed that the newly formed bone exhibited the highest Sr fractions and that low Ca diet increased the Sr uptake by a factor of three to four. Furthermore, Sr uptake in bone of the SrCl(2)-treated animals was generally lower compared with SrR. The study clearly shows that inadequate nutritional calcium intake significantly increases uptake of Sr in serum as well as in trabecular bone matrix. This indicates that nutritional calcium intake as well as serum Ca levels are important regulators of any Sr treatment.

  19. Effect of calcium chloride addition and draining pH on the microstructure and texture of full fat Cheddar cheese during ripening.

    PubMed

    Soodam, Kevany; Ong, Lydia; Powell, Ian B; Kentish, Sandra E; Gras, Sally L

    2015-08-15

    Calcium chloride is commonly added to cheese-milk to improve coagulum formation and to increase cheese yield but high concentrations of calcium ions can have adverse effects. In this study, confocal laser scanning microscopy and cryo-scanning electron microscopy were coupled with textural and chemical analyses to observe microstructural and biochemical changes that occur in cheese during ripening when calcium chloride is added or the draining pH altered. For the cheese prepared with no additional calcium at a draining pH of 6.0, the cheese porosity increased with ripening time and the number of protein vertices in the microscopy images declined, indicative of protein solubilisation. As the amount of CaCl2 added was increased, however, these changes became less significant. Our findings show that calcium chloride addition can be used, together with a lower draining pH, to alter the manufacturing process without significantly impacting on the quality of the mature cheese. PMID:25794728

  20. Sex- and dose-dependent effects of post-trial calcium channel blockade by magnesium chloride on memory for inhibitory avoidance conditioning.

    PubMed

    Wilmott, Lynda A; Thompson, Lucien T

    2013-11-15

    Calcium influx through voltage-dependent Ca(2+) channels is critical for many neuronal processes required for learning and memory. Persistent increases in cytosolic intracellular Ca(2+) concentrations in aging neurons are associated with learning impairments, while small transient subcellular changes in intracellular calcium concentrations play critical roles in neural plasticity in young neurons. In the present study, young male and female Fisher 344 × Brown Norway (FBN) hybrid rats were administered different doses of magnesium chloride (0.0, 100.0, or 200.0mg/kg, i.p.) following a single inhibitory avoidance training trial. Extracellular magnesium ions can non-specifically block voltage-gated calcium channels, and/or reduce the calcium conductance gated via glutamate and serine's activation of neuronal NMDA receptors. In our study, magnesium chloride dose-dependently enhanced memory compared to controls (significantly increased latency to enter a dark compartment previously paired with an aversive stimulus) when tested 48 h later as compared to controls. A leftward shift in the dose response curve for memory enhancement by magnesium chloride was observed for male compared to female rats. These findings provide further insights into calcium-dependent modulation of aversive memory, and should be considered when assessing the design of effective treatment options for both male and female patients with dementia or other memory problems.

  1. Superiority of experts over novices in trueness and precision of concentration estimation of sodium chloride solutions.

    PubMed

    Masuda, Tomohiro; Wada, Yuji; Okamoto, Masako; Kyutoku, Yasushi; Yamaguchi, Yui; Kimura, Atsushi; Kobayakawa, Tatsu; Kawai, Takayuki; Dan, Ippeita; Hayakawa, Fumiyo

    2013-03-01

    Several studies have reported that experts outperform novices in specific domains. However, the superiority of experts in accuracy, taking both trueness and precision into consideration, has not yet been explored. Here, we examined differences between expert and novice performances by evaluating the accuracy of their estimations of physical concentrations of sodium chloride in solutions while employing a visual analog scale. In Experiment 1, 14 experts and 13 novices tasted 6 concentrations of the solutions until they had learned their intensities. Subsequently, they repeatedly rated the concentration of 3 other solutions in random order. Although we did not find a difference between the performances of the 2 groups in trueness (difference between rating and correct concentration), the precision (consistency of ratings for each participant) of experts was higher than that of novices. In Experiment 2, 13 experts who had participated in Experiment 1 and 10 experts and 12 novices who had not participated in Experiment 1 rated the salt concentration in sodium chloride/sucrose mixtures in the same way as in Experiment 1. Both trueness and precision of performance were higher in both expert groups than in the novice group. By introducing precision and trueness parameters, we succeeded in quantifying the estimations of experts and novices in rating the concentration of solutions, revealing experts' superiority even for a task they had not been trained for.

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

    SciTech Connect

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

    1988-03-01

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

  3. First evidence on phloem transport of nanoscale calcium oxide in groundnut using solution culture technique

    NASA Astrophysics Data System (ADS)

    Deepa, Manchala; Sudhakar, Palagiri; Nagamadhuri, Kandula Venkata; Balakrishna Reddy, Kota; Giridhara Krishna, Thimmavajjula; Prasad, Tollamadugu Naga Venkata Krishna Vara

    2015-06-01

    Nanoscale materials, whose size typically falls below 100 nm, exhibit novel chemical, physical and biological properties which are different from their bulk counterparts. In the present investigation, we demonstrated that nanoscale calcium oxide particles (n-CaO) could transport through phloem tissue of groundnut unlike the corresponding bulk materials. n-CaO particles are prepared using sol-gel method. The size of the as prepared n-CaO measured (69.9 nm) using transmission electron microscopic technique (TEM). Results of the hydroponics experiment using solution culture technique revealed that foliar application of n-CaO at different concentrations (10, 50, 100, 500, 1,000 ppm) on groundnut plants confirmed the entry of calcium into leaves and stems through phloem compared to bulk source of calcium sprayed (CaO and CaNO3). After spraying of n-CaO, calcium content in roots, shoots and leaves significantly increased. Based on visual scoring of calcium deficiency correction and calcium content in plant parts, we may establish the fact that nanoscale calcium oxide particles (size 69.9 nm) could move through phloem tissue in groundnut. This is the first report on phloem transport of nanoscale calcium oxide particles in plants and this result points to the use of nanoscale calcium oxide particles as calcium source to the plants through foliar application, agricultural crops in particular, as bulk calcium application through foliar nutrition is restricted due to its non-mobility in phloem.

  4. The adsorption and inhibition effect of calcium lignosulfonate on Q235 carbon steel in simulated concrete pore solution

    NASA Astrophysics Data System (ADS)

    Wang, Yishan; Zuo, Yu; Zhao, Xuhui; Zha, Shanshan

    2016-08-01

    The corrosion inhibition of calcium lignosulfonate (CLS) for Q235 carbon steel in saturated Ca(OH)2 + 0.1 mol/L NaCl solution was studied by means of weight loss, polarization, fluorescence microscopy (FM), scanning electron microscopy/energy dispersive spectrometry (SEM/EDS), microscopic infrared spectral imaging (M-IR) and X-ray photoelectron spectroscopy (XPS). For the steel in simulated concrete pore solution (pH 12.6), an increase of Eb value and a decrease of icorr value occurred with different concentrations of CLS. The optimal content of CLS was 0.001 mol/L at which the inhibition rate was 98.86% and the Eb value increased to 719 mV after 10 h of immersion. In mortar solution and in reinforced concrete environment, CLS also showed good inhibition for steel. The preferential adsorption of CLS around pits was detected by M-IR. The result illustrates that at the early stage the adsorption of CLS was heterogeneous and CLS may have a competitive adsorption with chloride ions at the active sites, which would be beneficial for decreasing the susceptibility of pitting corrosion. After the pre-filming time, an intact adsorption CLS film formed on carbon steel surface. The adsorption between CLS and calcium presented as Casbnd Osbnd S bonds. The adsorption of CLS on carbon steel surface occurred probably by both physisorption and chemisorption.

  5. Aragonite nanorods in calcium carbonate/polymer hybrids formed through self-organization processes from amorphous calcium carbonate solution.

    PubMed

    Kajiyama, Satoshi; Nishimura, Tatsuya; Sakamoto, Takeshi; Kato, Takashi

    2014-04-24

    Nanostructured inorganic/polymer hybrid thin films comprising aragonite nanorods derived from aqueous suspensions of amorphous calcium carbonate (ACC) are prepared. For the formation of calcium carbonate (CaCO₃)/polymer hybrids, spincoated and annealed films of poly(vinyl alcohol) (PVA) that function as polymer matrices are soaked in aqueous colloidal solutions dispersing ACC stabilized by poly(acrylic acid) (PAA). In the initial stage, calcite thin films form on the surface. Subsequently, aragonite crystals start to form inside the PVA matrix that contains PVA crystallites which induce aragonite nucleation. Nanostructured hybrids composed of calcite thin films consisting of nanoparticles and assembled aragonite nanorods are formed in the matrices of PVA.

  6. Low-frequency dynamics of aqueous alkali chloride solutions as probed by terahertz spectroscopy

    NASA Astrophysics Data System (ADS)

    Kann, Z. R.; Skinner, J. L.

    2016-06-01

    Terahertz (far infrared) spectroscopy provides a useful tool for probing both ionic motions in solution and the effect of ionic solutes on the dynamics of the solvent. In this study, we calculate terahertz spectra of aqueous alkali chloride solutions using classical but novel (the water model includes three-body interactions, the ion parameterization is non-standard, and the dipole surface is polarizable) molecular dynamics simulations. The calculated spectra compare reasonably well to experimental spectra. Decomposition of the calculated spectra is used to gain a deeper understanding of the physical phenomena underlying the spectra and the connection to, for instance, the vibrational density of states for the ions. The decomposed results are also used to explain many of the cation-dependent trends observed in the experimental spectra.

  7. Low-frequency dynamics of aqueous alkali chloride solutions as probed by terahertz spectroscopy.

    PubMed

    Kann, Z R; Skinner, J L

    2016-06-21

    Terahertz (far infrared) spectroscopy provides a useful tool for probing both ionic motions in solution and the effect of ionic solutes on the dynamics of the solvent. In this study, we calculate terahertz spectra of aqueous alkali chloride solutions using classical but novel (the water model includes three-body interactions, the ion parameterization is non-standard, and the dipole surface is polarizable) molecular dynamics simulations. The calculated spectra compare reasonably well to experimental spectra. Decomposition of the calculated spectra is used to gain a deeper understanding of the physical phenomena underlying the spectra and the connection to, for instance, the vibrational density of states for the ions. The decomposed results are also used to explain many of the cation-dependent trends observed in the experimental spectra. PMID:27334173

  8. Hydrophobic collapse of foldamer capsules drives picomolar-level chloride binding in aqueous acetonitrile solutions.

    PubMed

    Hua, Yuran; Liu, Yun; Chen, Chun-Hsing; Flood, Amar H

    2013-09-25

    Aqueous media are competitive environments in which to perform host-guest chemistry, particularly when the guest is highly charged. While hydrophobic binding is a recognized approach to this challenge in which apolar pockets can be designed to recognize apolar guests in water, complementary strategies are required for hydrophilic anions like chloride. Here, we present evidence of such an alternative mechanism, used everyday by proteins yet rare for artificial receptors, wherein hydrophobic interactions are shown to be responsible for organizing and stabilizing an aryl-triazole foldamer to help extract hydrophilic chloride ions from increasingly aqueous solutions. Therein, a double-helical complex gains stability upon burial of ∼80% of the π surfaces that simultaneously creates a potent, solvent-excluding microenvironment for hydrogen bonding. The chloride's overall affinity to the duplex is substantial in 25% water v/v in acetonitrile (log β2 = 12.6), and it remains strong (log β2 = 13.0) as the water content is increased to 50%. With the rise in predictable designs of abiological foldamers, this water-assisted strategy can, in principle, be utilized for binding other hydrophilic guests.

  9. Limitations to the effectiveness of subcutaneous calcium solutions as a treatment for cows with milk fever.

    PubMed

    Fenwick, D C

    1994-04-23

    Serum calcium concentrations were determined in 164 cases of milk fever (mostly Jersey cows) attended in the course of practice in a cold, wet winter rainfall area where the cows calved at pasture. The mean calcium concentration of the cows receiving no calcium therapy subcutaneously before sampling (1.0 mmol/litre) was significantly (P < 0.01) less than the mean of 1.4 mmol/litre for cows receiving 300 ml of 33.3 or 40 per cent calcium borogluconate solution, which was significantly (P < 0.01) less than the mean of 2.1 mmol/litre for those receiving 600 ml subcutaneously. Neither the rectal temperature of the cows nor the average time interval between the injection of the two bottles and blood sampling had any effect on the serum calcium of the latter cows, whereas the rectal temperature but not the time interval had a significant (P < 0.01) effect on the serum calcium of the cows receiving 300 ml; the lower their temperature, the lower the calcium concentration. The mean (+/- sd) interval between treatment by the herdsman and veterinary attention for the cows receiving 300 ml (4.8 +/- 4.9 hours was significantly (P < 0.01) shorter than for the cows receiving 600 ml (12.0 +/- 9.4 hours). At the time of sampling, 48 per cent of the cows receiving 600 ml of calcium borogluconate solution had a serum calcium concentration below 2.0 mmol/litre.

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

    PubMed

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

    2016-10-01

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

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

    PubMed

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

    2016-10-01

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

  12. The calcium-activated chloride channel anoctamin 1 acts as a heat sensor in nociceptive neurons.

    PubMed

    Cho, Hawon; Yang, Young Duk; Lee, Jesun; Lee, Byeongjoon; Kim, Tahnbee; Jang, Yongwoo; Back, Seung Keun; Na, Heung Sik; Harfe, Brian D; Wang, Fan; Raouf, Ramin; Wood, John N; Oh, Uhtaek

    2012-05-27

    Nociceptors are a subset of small primary afferent neurons that respond to noxious chemical, thermal and mechanical stimuli. Ion channels in nociceptors respond differently to noxious stimuli and generate electrical signals in different ways. Anoctamin 1 (ANO1 also known as TMEM16A) is a Ca(2+)-activated chloride channel that is essential for numerous physiological functions. We found that ANO1 was activated by temperatures over 44 °C with steep heat sensitivity. ANO1 was expressed in small sensory neurons and was highly colocalized with nociceptor markers, which suggests that it may be involved in nociception. Application of heat ramps to dorsal root ganglion (DRG) neurons elicited robust ANO1-dependent depolarization. Furthermore, knockdown or deletion of ANO1 in DRG neurons substantially reduced nociceptive behavior in thermal pain models. These results indicate that ANO1 is a heat sensor that detects nociceptive thermal stimuli in sensory neurons and possibly mediates nociception.

  13. Low temperature solution deposition of calcium phosphate coatings for orthopedic implants

    SciTech Connect

    Campbell, A.A.; Graff, G.L.

    1994-04-01

    Calcium phosphate coatings were grown from aqueous solution onto a derivatized self-assmebled monolayer (SAM) which was covalently bound to a titanium metal substrate. The SAM molecules provided an idea connection between the metal surface and the calcium phosphate coating. The trichlorosilane terminus of the SAM molecule insured covalent attachment to the surface, while the functionalized ``tail`` induced heterogeneous nucleation of the calcium phosphate coating from supersaturated solutions. This low temperature process allowed for uniform coatings to be produced onto complex-shaped and/or microporous surfaces and provided better control of phase purity.

  14. Self-cleavage of Human CLCA1 Protein by a Novel Internal Metalloprotease Domain Controls Calcium-activated Chloride Channel Activation*♦

    PubMed Central

    Yurtsever, Zeynep; Sala-Rabanal, Monica; Randolph, David T.; Scheaffer, Suzanne M.; Roswit, William T.; Alevy, Yael G.; Patel, Anand C.; Heier, Richard F.; Romero, Arthur G.; Nichols, Colin G.; Holtzman, Michael J.; Brett, Tom J.

    2012-01-01

    The chloride channel calcium-activated (CLCA) family are secreted proteins that regulate both chloride transport and mucin expression, thus controlling the production of mucus in respiratory and other systems. Accordingly, human CLCA1 is a critical mediator of hypersecretory lung diseases, such as asthma, chronic obstructive pulmonary disease, and cystic fibrosis, that manifest mucus obstruction. Despite relevance to homeostasis and disease, the mechanism of CLCA1 function remains largely undefined. We address this void by showing that CLCA proteins contain a consensus proteolytic cleavage site recognized by a novel zincin metalloprotease domain located within the N terminus of CLCA itself. CLCA1 mutations that inhibit self-cleavage prevent activation of calcium-activated chloride channel (CaCC)-mediated chloride transport. CaCC activation requires cleavage to unmask the N-terminal fragment of CLCA1, which can independently gate CaCCs. Gating of CaCCs mediated by CLCA1 does not appear to involve proteolytic cleavage of the channel because a mutant N-terminal fragment deficient in proteolytic activity is able to induce currents comparable with that of the native fragment. These data provide both a mechanistic basis for CLCA1 self-cleavage and a novel mechanism for regulation of chloride channel activity specific to the mucosal interface. PMID:23112050

  15. A functional tandem between transient receptor potential canonical channels 6 and calcium-dependent chloride channels in human epithelial cells.

    PubMed

    Bertrand, Johanna; Dannhoffer, Luc; Antigny, Fabrice; Vachel, Laura; Jayle, Christophe; Vandebrouck, Clarisse; Becq, Frédéric; Norez, Caroline

    2015-10-15

    TRPC6 plays important human physiological functions, notably in artery and arterioles constriction, in regulation of vascular volume and in bronchial muscle constriction. It is implicated in pulmonary hypertension, cardiovascular disease, and focal segmental glomerulosclerosis and seems to play a role in cancer development. Previously, we identified Guanabenz, an α2-adrenergic agonist used for hypertension treatment (Wytensin®), as an activator of calcium-dependent chloride channels (CaCC) in human Cystic Fibrosis (CF) nasal epithelial cells by transiently increasing [Ca2+]i via an influx of extracellular Ca2+. In this study, using assays to measure chloride channel activity, we show that guanabenz is an activator of CaCC in freshly dissociated human bronchial epithelial cells from three CF patients with various genotypes (F508del/F508del, F508del/R1066C, F508del/H1085R). We further characterised the effect of guanabenz and show that it is independent of α-adrenergic receptors, is inhibited by the TRPC family inhibitor SKF-96365 but not by the TRPV family inhibitor ruthenium red. Using western-blotting, Ca2+ measurements and iodide efflux assay, we found that TRPC1 siRNA has no effect on guanabenz induced responses whereas TRPC6 siRNA prevented the guanabenz-dependent Ca2+ influx and the CaCC-dependent activity stimulated by guanabenz. In conclusion, we show that TRPC6 channel is pivotal for the activation of CaCC by guanabenz through a α2-adrenergic-independent pathway in human airway epithelial cells. We suggest propose a functional coupling between TRPC6 and CaCC and guanabenz as a potential TRPC6 activator for exploring TRPC6 and CaCC channel functions and corresponding channelopathies.

  16. Enhanced inactivation of avian influenza virus at -20°C by disinfectants supplemented with calcium chloride or other antifreeze agents.

    PubMed

    Guan, Jiewen; Chan, Maria; Brooks, Brian W; Rohonczy, Elizabeth

    2015-10-01

    Avian influenza outbreaks have occurred during winter months, and effective disinfection of poultry premises at freezing temperatures is needed. The commercial disinfectants Virkon and Accel, supplemented with an antifreeze agent [propylene glycol (PG), methanol (MeOH), or calcium chloride (CaCl₂)], were evaluated for their effectiveness in killing avian influenza virus (AIV) at -20°C or 21°C. An AIV suspension was applied to stainless steel disks, air-dried, and covered with a disinfectant or antifreeze agent for 5 to 30 min. Virkon (2%) and Accel (6.25%) with 30% PG, 20% MeOH, or 20% CaCl₂ inactivated 6 log₁₀ AIV within 5 min at -20°C and 21°C. At these temperatures PG and MeOH alone did not kill AIV, but the 20% CaCl₂ solution alone inactivated 5 log10 AIV within 10 min. The results suggested that CaCl₂ is potentially useful to enhance the effectiveness of disinfection of poultry facilities after outbreaks of AIV infection in warm and cold seasons.

  17. Enhanced inactivation of avian influenza virus at −20°C by disinfectants supplemented with calcium chloride or other antifreeze agents

    PubMed Central

    Guan, Jiewen; Chan, Maria; Brooks, Brian W.; Rohonczy, Elizabeth

    2015-01-01

    Avian influenza outbreaks have occurred during winter months, and effective disinfection of poultry premises at freezing temperatures is needed. The commercial disinfectants Virkon and Accel, supplemented with an antifreeze agent [propylene glycol (PG), methanol (MeOH), or calcium chloride (CaCl2)], were evaluated for their effectiveness in killing avian influenza virus (AIV) at −20°C or 21°C. An AIV suspension was applied to stainless steel disks, air-dried, and covered with a disinfectant or antifreeze agent for 5 to 30 min. Virkon (2%) and Accel (6.25%) with 30% PG, 20% MeOH, or 20% CaCl2 inactivated 6 log10 AIV within 5 min at −20°C and 21°C. At these temperatures PG and MeOH alone did not kill AIV, but the 20% CaCl2 solution alone inactivated 5 log10 AIV within 10 min. The results suggested that CaCl2 is potentially useful to enhance the effectiveness of disinfection of poultry facilities after outbreaks of AIV infection in warm and cold seasons. PMID:26424918

  18. The stability of aqueous nickel(II) chloride complexes in hydrothermal solutions: Results of UV-Visible spectroscopic experiments

    NASA Astrophysics Data System (ADS)

    Liu, Weihua; Migdisov, Artas; Williams-Jones, Anthony

    2012-10-01

    Knowledge of the thermodynamic properties of aqueous nickel chloride complexes is important for understanding and quantitatively evaluating nickel transport in hydrothermal systems. In this paper, UV-Visible spectroscopic measurements are reported for dissolved nickel in perchlorate, triflic acid and sodium chloride solutions at temperatures up to 250 °C and 100 bar. The observed molar absorbance of Ni2+ in both perchlorate and triflic acid solutions is similar, and the absorbance peak migrates toward lower energy (red-shift) with increasing temperature. The spectra of nickel chloride solutions show a systematic red-shift with increasing temperature and/or chloride concentration. This allowed identification of the nickel chloride species as NiCl+, NiCl2(aq) and NiCl3-, and determination of their formation constants. Based on the experimental data reported in this paper and those of previous experimental studies, formation constants for these nickel chloride complexes have been calculated for temperatures up to 700 °C and pressures up to 2000 bar. The solubility of millerite (NiS) and pentlandite (Ni4.5Fe4.5S8) calculated using these constants shows that nickel dissolves in significantly higher concentrations in hydrothermal solutions than previously estimated. However, the solubility is considerably lower than for corresponding cobalt sulphide minerals. This may explain why hydrothermal nickel deposits are encountered so much less frequently than hydrothermal deposits of cobalt.

  19. Equilibrium dialysis and ultrafiltration investigations of perchlorate removal from aqueous solution using poly(diallyldimethylammonium) chloride.

    PubMed

    Roach, Jim D; Tush, Daniel

    2008-02-01

    Use of perchlorate salts in military activities and the aerospace industry is widespread. These salts are highly water-soluble and are, to a large extent, kinetically inert as aqueous species. As a groundwater contaminant, perchlorate is now being detected in an increasing number of locations and is believed to interfere with the uptake of iodide by the thyroid, which can result in decreased hormone production. The United States Environmental Protection Agency (US EPA) has established a reference dose for perchlorate of 0.0007 mg/kg/day, which translates to a drinking water equivalent level of 24.5 ppb. This study investigated the application of polyelectrolyte-enhanced ultrafiltration (PEUF) for the selective removal of perchlorate from aqueous solution through equilibrium dialysis and ultrafiltration experiments. Using poly(diallyldimethylammonium) chloride, the effectiveness and efficiency of PEUF in the removal of perchlorate from other aqueous solution components was investigated by testing parameters such as polyelectrolyte concentration, pH, and ionic strength. Removal of perchlorate from synthetic groundwater initially containing 10.3 ppm perchlorate and also containing chloride, sulfate, and carbonate was also examined. Perchlorate separations of greater than 95% were achieved, even in the presence of 10-fold excesses of competing ions. PMID:17915279

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

    PubMed

    Corradini, D; Gallo, P; Rovere, M

    2010-07-21

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

  1. Morphological analysis of pits formed on Al 2024-T3 in chloride aqueous solution

    NASA Astrophysics Data System (ADS)

    Silva, J. W. J.; Bustamante, A. G.; Codaro, E. N.; Nakazato, R. Z.; Hein, L. R. O.

    2004-09-01

    It has been used a new image analysis method, based on segmentation by shape parameters, for pits morphology examination from Al 2024 aluminum-copper alloy in chloride aqueous solution. Corrosion behavior of this alloys in naturally aerated 3.5% NaCl solution has been investigated through open circuit potential measurements. Afterwards, pits have been characterized by image analysis taking density and size measurements right from corroded surfaces. Morphological investigation has been conducted for profiles, cut orthogonally from mean surface planes, and observed through light microscopy. Image analysis data could demonstrate that pits are wider than deep, evoluting for conical, quasi-conical or irregular shapes. Most pits have presented a quasi-conical morphology, but the wider ones have evoluted to an irregular shape influenced by sub-surface microstructure. Image analysis based on shape segmentation could enhance the differences on morphological behavior.

  2. Formation of calcium complexes by borogluconate in vitro and during calcium borogluconate infusion in sheep.

    PubMed

    Farningham, D A

    1985-07-01

    The effect of borogluconate on plasma calcium fractions was studied in vitro and in vivo in sheep. In vitro calcium chloride was more effective in raising ionised plasma calcium than calcium borogluconate. Sodium borate or gluconate added to blood caused only small decreases in blood ionised calcium. However, together, a synergistic reduction in ionised calcium was observed. Following calcium borogluconate infusions into sheep, total plasma calcium rose primarily because of an increase in the unionised ultrafiltrable fraction. Other changes observed following the infusion were hypercalciuria, decreased glomerular filtration rate and acidosis. Sodium borogluconate administered subcutaneously lowered total plasma calcium. This probably resulted from enhanced calcium excretion. It is suggested that since the anionic component of calcium solutions alters the availability and retention of calcium, it is likely to affect clinical efficacy significantly.

  3. ¹H NMR diffusion studies of water self-diffusion in supercooled aqueous sodium chloride solutions.

    PubMed

    Garbacz, Piotr; Price, William S

    2014-05-01

    The physical properties of aqueous sodium chloride solutions have been studied theoretically, but so far no experimental diffusion data have been obtained under supercooled conditions. Here the results of (1)H NMR translational diffusion measurements of water in sodium chloride solutions in the temperature range 230 to 300 K and sodium chloride concentrations up to 4.2 mol/kg are presented. It was found that the diffusion data were well-described by the Vogel-Tamman-Fulcher relationship with concentration-dependent parameters D0, B, and T0. The results indicate that under supercooled conditions the influence of sodium chloride on water diffusion is much smaller than predicted by molecular dynamics simulations.

  4. Use of cyclodextrin and calcium chloride for enhanced removal of mercury from soil.

    PubMed

    Wang, Xiaojiang; Yolcubal, Irfan; Wang, Weizi; Artiola, Janick; Maier, Raina; Brusseau, Mark

    2004-08-01

    The use of solutions containing carboxymethyl-beta-cyclodextrin (CMCD) or CaCl2 for enhancing the removal of Hg from a sandy soil was investigated using batch and column experiments. The retention of Hg appeared to be controlled by specific adsorption reactions, which greatly constrained Hg removal when using water (KNO3 solution) to flush columns packed with contaminated soil. The results showed that the two reagents did enhance the removal of Hg from the soil. For example, 81% and 60% of Hg was recovered after 50 pore volumes of flushing with 50 mM CaCl2 and 2 mM CMCD, respectively, compared to 24% recovery for a 10 mM KNO3 solution. However, significant tailing and delayed recovery of Hg during the elution process occurred in the presence of all reagents, indicating that the removal of Hg from the soil was rate limited.

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

    NASA Astrophysics Data System (ADS)

    Kovács, A.; Wojnárovits, L.; El-assy, N. B.; Afeefy, H. Y.; Al-Sheikhly, M.; Walker, M. L.; McLaughlin, W. L.

    1995-09-01

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

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

    PubMed Central

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

    2007-01-01

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

  7. [Effects of calcium-activated chloride channels on vascular activity of rat cerebral basilar artery].

    PubMed

    Wang, Rui; Li, Li; Ma, Ke-Tao; Si, Jun-Qiang

    2014-06-25

    This study investigated the role of calcium-activated Cl⁻ channels (CaCCs) in mediating vasomotor activity of cerebral basilar artery (BA) of Wistar rat. Pressure myograph was used to examine the changes in diameter of isolated BA to vasoactive reagents. The results showed that (1) The rate of pressure-induced vasomotor activity was 78.6% (n = 28) in BA from 0 to 100 mmHg working pressure. The contractile phase of the response was faster than the relaxation phase; (2) The amplitude of contraction was (62.6 ± 6.4) µm (n = 22), the frequency of contraction was variable and the highest value was 8.0 ± 2.3 per 5 min at 60 mmHg working pressure (n = 22); (3) The pressure-induced vasomotor activity of BA was markedly attenuated when Ca²⁺ was removed from medium; (4) The pressure-induced vasomotor activity was blocked by voltage dependent Ca²⁺ channel blocker nimodipine; (5) The pressure-induced vasomotor was inhibited by CaCC antagonists NFA and NPPB. These results suggest that the pressure-induced vasomotor activity of isolated BA is associated with Ca²⁺ influx that activates CaCCs.

  8. Proteome responses of Citrobacter werkmanii BF-6 planktonic cells and biofilms to calcium chloride.

    PubMed

    Zhou, Gang; Shi, Qing-shan; Huang, Xiao-mo; Xie, Xiao-bao

    2016-02-01

    Calcium ions are well-known as intracellular second messengers that also have an important extracellular structural role for bacteria. Recently, we found that denser biofilms were formed by Citrobacter werkmanii BF-6 in the presence of 400 mM Ca(2+) than that of 12.5mM Ca(2+). Therefore, we employed two-dimensional (2-D) electrophoresis methods to investigate the proteome profiles of planktonic cells and biofilms in BF-6 under different concentrations of Ca(2+). Meanwhile, BF-6 biofilm architecture was also visualized with confocal laser scanning microscopy (CLSM). The results demonstrated that BF-6 biofilms formed at the bottom of microtiter plates when grown in the presence of 400 mM Ca(2+). A total of 151 proteins from planktonic cells and biofilms after exposure of BF-6 cells to 12.5 and 400 mM Ca(2+) were successfully identified. Different gene ontology (GO) and KEGG pathways were categorized and enriched for the above proteins. Growth in the presence of 400 mM Ca(2+) induced more complex signal pathways in BF-6 than 12.5mM Ca(2+). In addition, the biofilm architectures were also affected by Ca(2+). Our results show two different modes of biofilm enhancement for C. werkmanii in the presence of excess Ca(2+) and provide a preliminary expression of these differences based on proteomic assays.

  9. Structure simulations for the 0.22 and 1 molar aqueous dimethylammonium chloride solutions.

    PubMed

    Nagy, Peter I

    2012-01-14

    Monte Carlo simulations have been performed for characterizing the 0.22 and 1 molar aqueous dimethylammonium chloride solutions at p = 1 atm and T = 310 K. On the basis of potential of mean force curves for the two systems with increasing concentrations, the N···N separations of about 8.7 and 7.5 Å correspond to a vague and a more pronounced minimum, respectively. Nitrogen separations at the minima are considerably smaller than those what the cations would take if the solutes comprised uniform local solute density on a microscale. The derived N by N coordination numbers predict non-negligible cation association and concomitant inhomogeneity for the studied systems. The calculated N···N distance distribution in the molar solution indicates that about 12% of the N···N separations are shorter than 8.5 Å compared with R(N···N) = 11.84 Å corresponding to the closest distance in a uniform cation local density. Despite a global minimum of -1.79 ± 0.63 kcal mol(-1) at N···Cl separation of 3.24 Å, obtained from the pmf for the 0.22 molar model, the N by Cl coordination number is only 0.14 in the first coordination shell, suggesting frequent disruption of an N-H(+)···Cl(+) hydrogen bond in a relatively dilute solution. The expression for the chemical potential of a solute includes a concentration-dependent activity coefficient, whose varying values are expected to reflect the different degrees of solute association in the 0.2-1 molar range. Theoretical follow-up of the changes in the activity coefficient values is difficult, thus calculation of the K(c) equilibrium constant has been proposed by considering 1 molar solutions as the standard state.

  10. [The influence of an isotonic solution containing benzalkonium chloride and a hypertonic seawater solution on the function of ciliary epithelium from the nasal cavity in vitro].

    PubMed

    Laberko, E L; Bogomil'sky, M R; Soldatsky, Yu L; Pogosova, I E

    2016-01-01

    The objective of the present study was to evaluate the influence of an isotonic saline solution containing benzalconium chloride and of a hypertonic seawater solution on the function of ciliary epithelium in the nasal cavity in vitro. To this effect, we investigated the cytological material obtained from 35 children presenting with adenoid tissue hypertrophy. The tissue samples were taken from the nasal cavity by the standard method. A cellular biopsy obtained from each patient was distributed between three tubes that contained isotonic saline solution supplemented by benzalconium chloride (0.1 mg/ml), a hypertonic seawater solution, and a standard physiological saline solution. It was shown that the number of the viable cells in both isotonic solutions was statistically comparable and significantly higher than in the hypertonic solution (p<0.05). The ciliary beat frequency of the cells embedded in the two isotonic solutions was not significantly different but considerably exceeded that in the hypertonic seawater solution (p<0.05). Thus, the present study has demonstrated the absence of the ciliotoxic influence of isotonic saline solution containing benzalconium chloride at a concentration of 0.1 mg/ml and the strong ciliotoxic effect of the hypertonic seawater solution. This finding gives reason to recommend isotonic solutions for the regular application whereas hypertonic solutions can be prescribed only during infectious and/or inflammatory ENT diseases. PMID:27213656

  11. [The influence of an isotonic solution containing benzalkonium chloride and a hypertonic seawater solution on the function of ciliary epithelium from the nasal cavity in vitro].

    PubMed

    Laberko, E L; Bogomil'sky, M R; Soldatsky, Yu L; Pogosova, I E

    2016-01-01

    The objective of the present study was to evaluate the influence of an isotonic saline solution containing benzalconium chloride and of a hypertonic seawater solution on the function of ciliary epithelium in the nasal cavity in vitro. To this effect, we investigated the cytological material obtained from 35 children presenting with adenoid tissue hypertrophy. The tissue samples were taken from the nasal cavity by the standard method. A cellular biopsy obtained from each patient was distributed between three tubes that contained isotonic saline solution supplemented by benzalconium chloride (0.1 mg/ml), a hypertonic seawater solution, and a standard physiological saline solution. It was shown that the number of the viable cells in both isotonic solutions was statistically comparable and significantly higher than in the hypertonic solution (p<0.05). The ciliary beat frequency of the cells embedded in the two isotonic solutions was not significantly different but considerably exceeded that in the hypertonic seawater solution (p<0.05). Thus, the present study has demonstrated the absence of the ciliotoxic influence of isotonic saline solution containing benzalconium chloride at a concentration of 0.1 mg/ml and the strong ciliotoxic effect of the hypertonic seawater solution. This finding gives reason to recommend isotonic solutions for the regular application whereas hypertonic solutions can be prescribed only during infectious and/or inflammatory ENT diseases.

  12. Effect of calcium chloride on the hydration and leaching of lead-retarded cement

    SciTech Connect

    Cheeseman, C.R.; Asavapisit, S. )

    1999-06-01

    The effect of adding CaCl[sub 2] to ordinary portland cement containing 10% (by weight) of a synthetic lead hydroxide waste has been investigated using differential thermal analysis, conduction calorimetry, and by analyzing solutions extracted from mixes during the early stages of hydration. Lead wastes are known to retard initial cement hydration reactions, and for the waste loading used in these experiments the peak in the heat of hydration curve was delayed from 8.7 to 172 h. The addition of CaCl[sub 2] reduced this retarding effect but was associated with a decrease in the overall extent of cement hydration, particularly at high CaCl[sub 2] concentrations. The acceleration induced is associated with lower concentrations of hydroxyl ions in solution. This reduces dissolution and subsequent adsorption of Pb(OH)[sub 3][sup [minus

  13. Two competitive nucleation mechanisms of calcium carbonate biomineralization in response to surface functionality in low calcium ion concentration solution

    PubMed Central

    Deng, Hua; Wang, Shuo; Wang, Xiumei; Du, Chang; Shen, Xingcan; Wang, Yingjun; Cui, Fuzhai

    2015-01-01

    Four self-assembled monolayer surfaces terminated with –COOH, –OH, –NH2 and –CH3 functional groups are used to direct the biomineralization processes of calcium carbonate (CaCO3) in low Ca2+ concentration, and the mechanism of nucleation and initial crystallization within 12 h was further explored. On −COOH surface, nucleation occurs mainly via ion aggregation mechanism while prenucleation ions clusters may be also involved. On −OH and −NH2 surfaces, however, nucleation forms via calcium carbonate clusters, which aggregate in solution and then are adsorbed onto surfaces following with nucleation of amorphous calcium carbonate (ACC). Furthermore, strongly negative-charged −COOH surface facilitates the direct formation of calcites, and the −OH and −NH2 surfaces determine the formation of vaterites with preferred crystalline orientations. Neither ACC nor crystalline CaCO3 is observed on −CH3 surface. Our findings present a valuable model to understand the CaCO3 biomineralization pathway in natural system where functional groups composition plays a determining role during calcium carbonate crystallization. PMID:26814639

  14. Two competitive nucleation mechanisms of calcium carbonate biomineralization in response to surface functionality in low calcium ion concentration solution.

    PubMed

    Deng, Hua; Wang, Shuo; Wang, Xiumei; Du, Chang; Shen, Xingcan; Wang, Yingjun; Cui, Fuzhai

    2015-09-01

    Four self-assembled monolayer surfaces terminated with -COOH, -OH, -NH2 and -CH3 functional groups are used to direct the biomineralization processes of calcium carbonate (CaCO3) in low Ca(2+) concentration, and the mechanism of nucleation and initial crystallization within 12 h was further explored. On -COOH surface, nucleation occurs mainly via ion aggregation mechanism while prenucleation ions clusters may be also involved. On -OH and -NH2 surfaces, however, nucleation forms via calcium carbonate clusters, which aggregate in solution and then are adsorbed onto surfaces following with nucleation of amorphous calcium carbonate (ACC). Furthermore, strongly negative-charged -COOH surface facilitates the direct formation of calcites, and the -OH and -NH2 surfaces determine the formation of vaterites with preferred crystalline orientations. Neither ACC nor crystalline CaCO3 is observed on -CH3 surface. Our findings present a valuable model to understand the CaCO3 biomineralization pathway in natural system where functional groups composition plays a determining role during calcium carbonate crystallization.

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

    SciTech Connect

    Mamontov, Eugene; O'Neill, Hugh Michael

    2014-01-01

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

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

    PubMed

    Mamontov, Eugene; O'Neill, Hugh

    2014-06-01

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

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

    SciTech Connect

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

    1988-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Yang, Di

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

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

    PubMed

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

    2016-01-25

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

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

    SciTech Connect

    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.

  1. Aluminum compounds in calcium chloride extracts from podzolic soil and their possible sources

    NASA Astrophysics Data System (ADS)

    Tolpeshta, I. I.; Sokolova, T. A.

    2008-06-01

    Aluminum concentrations in organoaluminum complexes, mineral polymers, Al(H2O){6/3+}, Al(OH)(H2O){5/2+}, Al(OH)2(H2O){4/+}, AlH3SiO{4/2+}, and Al(OH)3(H2O){3/0} extracted with 0.001 M CaCl2 from the main genetic horizons of a podzolic soil on two-layered deposits were determined experimentally and calculated from thermodynamic equations. It was found that aluminum bound in organic complexes was predominant in extracts from the AE horizon, and mineral polymer aluminum compounds prevailed in extracts from the E and IIBD horizons. In the AE horizon, organoaluminum compounds were a major source of aluminum, which passed into solution predominantly by exchange reactions. In the E horizon, aluminum hydroxide interlayers in soil chlorites were the main source of aluminum, which passed into solution by dissolution reactions. In extracts from the IIBD horizon, aluminum was solubilized by the dissolution of aluminosilicates inherited from the parent rock.

  2. Equilibriums between Cu, Fe, and Zn sulfides and oxides in chloride solution: A thermodynamic study

    NASA Astrophysics Data System (ADS)

    Strel'Tsova, N. I.

    2009-10-01

    The results of thermodynamic modeling of equilibriums between Cu, Fe, and Zn sulfides and oxides pertaining to the Cu-Fe-Zn-S-O2 system in water and aqueous chloride solution are presented. The system comprises solid phases of constant composition: pyrite, pyrrhotite, hematite, magnetite, wüstite, γ-iron, chalcocite, covellite, cuprite, native copper, chalcopyrite, and bornite, as well as more than 100 ions, complexes, and molecules in an aqueous solution. The GIBBS program with the UNITHERM thermodynamic dataset used in calculations allows numerical analysis of phase assemblages in a dry system and in equilibrium with an aqueous solution. How the temperature, pressure, and the composition of the solution in the system opened for oxygen and sulfur affects the composition of phase assemblages was considered in temperature and pressure ranges of 50-350 C and 100-1000 bar, respectively. Decrease in temperature leads to a shift in stability fields of the studied phases toward the region of elevated oxygen and sulfur partial pressures. Variation of temperature is an important factor affecting precipitation of ore minerals, primarily, Cu- and Zn-bearing. The calculation results are presented in tables and diagrams. Each point in the (log m_{S_{tot} } - log f_{O_2 } ) diagram is characterized by a single possible assemblage of phases equilibrated with a solution of the given composition within the considered temperature and pressure range. Since the composition of the mineral assemblage is controlled by physicochemical conditions at the moment of mineral formation, comparison of the calculation results with mineral assemblages at ore deposits makes it possible to estimate the parameters of ore deposition at the early stage of investigation, including oxygen and sulfur activity and, occasionally, the composition and salinity of the solution. These parameters control the formation of such assemblages.

  3. Generalized chloride mass balance: Forward and inverse solutions for one-dimensional tracer convection under transient flux

    SciTech Connect

    Ginn, T.R.; Murphy, E.M.

    1996-12-01

    Forward and inverse solutions are provided for analysis of inert tracer profiles resulting from one-dimensional convective transport under fluxes which vary with time and space separately. The developments are displayed as an extension of conventional chloride mass balance (CMB) techniques to account for transient as well as space-dependent water fluxes. The conventional chloride mass balance has been used over two decades to estimate recharge over large time scales in arid environments. In this mass balance approach, the chloride concentration in the pore water, originating from atmospheric fallout, is inversely proportional to the flux of water through the sediments. The CMB method is especially applicable to arid and semi-arid regions where evapotranspirative enrichment of the pore water produces a distinct chloride profile in the unsaturated zone. The solutions presented allow incorporation of transient fluxes and boundary conditions in CMB analysis, and allow analysis of tracer profile data which is not constant with depth below extraction zone in terms of a rational water transport model. A closed-form inverse solution is derived which shows uniqueness of model parameter and boundary condition (including paleoprecipitation) estimation, for the specified flow model. Recent expressions of the conventional chloride mass balance technique are derived from the general model presented here; the conventional CMB is shown to be fully compatible with this transient flow model and it requires the steady-state assumption on chloride mass deposition only (and not on water fluxes or boundary conditions). The solutions and results are demonstrated on chloride profile data from west central New Mexico.

  4. Structural changes in axillary eccrine glands following long-term treatment with aluminium chloride hexahydrate solution.

    PubMed

    Hölzle, E; Braun-Falco, O

    1984-04-01

    Axillary skin biopsies from fifteen patients with axillary hyperhidrosis who had received long-term treatment with aqueous aluminium chloride solution were examined histologically. The apocrine glands were normal, but the eccrine glands showed conspicuous morphological changes of varying severity. These included vacuolization of the secretory epithelium, dilatation of eccrine acini with atrophy of secretory cells, and accumulation of PAS-positive, diastase-resistant material in the dilated lumen of the secretory coils. The histological changes correlated in most patients with decreased secretion of sweat. We conclude that long-term blockage of the distal acrosyringium due to aluminium salts may lead to functional and structural degeneration of the eccrine acini. PMID:6712884

  5. A method of calculating quartz solubilities in aqueous sodium chloride solutions

    USGS Publications Warehouse

    Fournier, R.O.

    1983-01-01

    The aqueous silica species that form when quartz dissolves in water or saline solutions are hydrated. Therefore, the amount of quartz that will dissolve at a given temperature is influenced by the prevailing activity of water. Using a standard state in which there are 1,000 g of water (55.51 moles) per 1,000 cm3 of solution allows activity of water in a NaCl solution at high temperature to be closely approximated by the effective density of water, pe, in that solution, i.e. the product of the density of the NaCl solution times the weight fraction of water in the solution, corrected for the amount of water strongly bound to aqueous silica and Na+ as water of hydration. Generally, the hydration of water correction is negligible. The solubility of quartz in pure water is well known over a large temperature-pressure range. An empirical formula expresses that solubility in terms of temperature and density of water and thus takes care of activity coefficient and pressure-effect terms. Solubilities of quartz in NaCl solutions can be calculated by using that equation and substituting pe, for the density of pure water. Calculated and experimentally determined quartz solubilities in NaCl solutions show excellent agreement when the experiments were carried out in non-reactive platinum, gold, or gold plus titanium containers. Reactive metal containers generally yield dissolved silica concentrations higher than calculated, probably because of the formation of metal chlorides plus NaOH and H2. In the absence of NaOH there appears to be no detectable silica complexing in NaCl solutions, and the variation in quartz solubility with NaCl concentration at constant temperature can be accounted for entirely by variations in the activity of water. The average hydration number per molecule of dissolved SiO2 in liquid water and NaCl solutions decreases from about 2.4 at 200??C to about 2.1 at 350??C. This suggests that H4SiO4 may be the dominant aqueous silica species at 350??C, but other

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

    SciTech Connect

    Bialy, Agata; Blanchard, Didier; Vegge, Tejs; Quaade, Ulrich J.

    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.

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

    PubMed

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

    2014-09-01

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

  8. Formation of aqueous solutions on Mars via deliquescence of chloride-perchlorate binary mixtures

    NASA Astrophysics Data System (ADS)

    Gough, R. V.; Chevrier, V. F.; Tolbert, M. A.

    2014-05-01

    Perchlorate salts, known to exist on Mars, can readily absorb water vapor and deliquesce into aqueous solutions even at low temperatures. The multiple soluble ionic species, such as chloride salts, present in the Martian subsurface may affect this deliquescence. Here we study the deliquescence (solid to aqueous transition) and efflorescence (aqueous to solid transition) of three perchlorate/chloride mixtures: KClO4/KCl at 253 K, NaClO4/NaCl at 243 and 253 K, and Mg(ClO4)2/MgCl2 at 243 and 253 K. A Raman microscope with an environmental cell was used to monitor the phase transitions of internally mixed ClO-4/Cl- particles as a function of the perchlorate mole fraction. The eutonic relative humidity (where deliquescence begins to occur regardless of ClO-4 mole fraction), deliquescence relative humidity (DRH, where complete deliquescence occurs), and efflorescence relative humidity (ERH) were measured for several perchlorate mole ratios for each cation system. At the temperatures studied, the eutonic relative humidity was measured to be 28% RH for Mg(ClO4)2/MgCl2 mixtures, 38% RH for NaClO4/NaCl mixtures, and 82% RH for KClO4/KCl mixtures. The DRH depends on the perchlorate mole ratio, but is below the DRH of the least deliquescent (highest DRH) pure salt. When humidity is lowered around an aqueous salt mixture, we find that efflorescence occurs at an RH below the DRH due to the kinetic inhibition of crystallization. The ERH values of the salt solutions were as low as 5% RH for Mg(ClO4)2/MgCl2 mixtures, as low as 13% RH for NaClO4/NaCl mixtures, and as low as 66% RH for KClO4/KCl mixtures. The low eutonic RH values for the Na+ and Mg2+ perchlorate/chloride mixtures are important: wherever Mg(ClO4)2 and MgCl2 or NaClO4 and NaCl coexist at the temperatures studied, mixtures will contain a stable aqueous phase above 28 or 38% RH, respectively, regardless of the perchlorate mole fraction. This liquid water may persist until 5 or 13% RH, respectively.

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

    NASA Astrophysics Data System (ADS)

    Walsh, Lois Harper

    1989-10-01

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

  10. Aqueous solutions of calcium ions: hydration numbers and the effect of temperature.

    PubMed

    Zavitsas, Andreas A

    2005-11-01

    Hydration numbers of calcium ions are determined from extensive measurements of colligative properties of water solutions of calcium salts. The hydration numbers reported refer to the average number of water molecules that are bound sufficiently strongly to calcium ions so as to be removed from the solvent and become part of the solute. Contrary to common descriptions of deviations from ideal behavior for concentrated solutions, ideal behavior is demonstrated when mole fractions are calculated by taking account of such bound water. Measurements over wide concentration and temperature ranges are used to obtain the effect of temperature on the average hydration number of Ca(2+). Freezing point depression measurements yield a hydration number of 12.0 +/- 0.8. Boiling point elevations yield 6.7 +/- 0.6. Consistent with this, vapor pressure measurements from 0 to 200 degrees C show a gradual decrease in hydration number with increasing temperature, with a value of 5.0 at 200 degrees C.

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

    SciTech Connect

    Vitus, C.M.; Isaacs, H.S.; Schroeder, V.

    1994-11-22

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

  12. Bile acids stimulate chloride secretion through CFTR and calcium-activated Cl- channels in Calu-3 airway epithelial cells.

    PubMed

    Hendrick, Siobhán M; Mroz, Magdalena S; Greene, Catherine M; Keely, Stephen J; Harvey, Brian J

    2014-09-01

    Bile acids resulting from the aspiration of gastroesophageal refluxate are often present in the lower airways of people with cystic fibrosis and other respiratory distress diseases. Surprisingly, there is little or no information on the modulation of airway epithelial ion transport by bile acids. The secretory effect of a variety of conjugated and unconjugated secondary bile acids was investigated in Calu-3 airway epithelial cells grown under an air-liquid interface and mounted in Ussing chambers. Electrogenic transepithelial ion transport was measured as short-circuit current (Isc). The taurine-conjugated secondary bile acid, taurodeoxycholic acid (TDCA), was found to be the most potent modulator of basal ion transport. Acute treatment (5 min) of Calu-3 cells with TDCA (25 μM) on the basolateral side caused a stimulation of Isc, and removal of extracellular Cl(-) abolished this response. TDCA produced an increase in the cystic fibrosis transmembrane conductance regulator (CFTR)-dependent current that was abolished by pretreatment with the CFTR inhibitor CFTRinh172. TDCA treatment also increased Cl(-) secretion through calcium-activated chloride (CaCC) channels and increased the Na(+)/K(+) pump current. Acute treatment with TDCA resulted in a rapid cellular influx of Ca(2+) and increased cAMP levels in Calu-3 cells. Bile acid receptor-selective activation with INT-777 revealed TGR5 localized at the basolateral membrane as the receptor involved in TDCA-induced Cl(-) secretion. In summary, we demonstrate for the first time that low concentrations of bile acids can modulate Cl(-) secretion in airway epithelial cells, and this effect is dependent on both the duration and sidedness of exposure to the bile acid.

  13. Extraction of diethylhexylphthalate from total nutrient solution-containing polyvinyl chloride bags.

    PubMed

    Mazur, H I; Stennett, D J; Egging, P K

    1989-01-01

    Total nutrient solution (TNS) is a new method for delivering total parenteral nutrition (TPN) by admixing dextrose, amino acids, and lipids in a single container. Recommendations are to use nonpolyvinyl chloride (PVC) containers for admixture of these solutions. PVC is a hard, brittle, and inflexible substance, and plasticizers, predominantly diethylhexylphthalate (DEHP), are added to impart flexibility. DEHP is a lipid soluble suspected carcinogen, hepatotoxin, and teratogen which has been shown to leach from PVC products containing lipophilic admixtures. The purpose of this study was to quantitate the amount of DEHP which leaches from PVC bags containing TNS. Six study groups, which contained three formulas stored at 25 degrees C +/- 2 degrees C and 4 degrees C +/- 1 degree C, were assayed for DEHP at time 0, 12, 24, 48 and 72 hr, 1 wk, and 3 wk using high-performance liquid chromatography. The control group contained an amino acid source, a carbohydrate source, and standard electrolytes, and the other groups contained a 10% lipid source or a 20% lipid source in addition to the constituents of the control group. Lipid-containing groups demonstrated detectable levels of DEHP at 48 hr, and DEHP content increased in these groups throughout the 21-day study. DEHP concentrations were lower in lipid-containing groups stored at 4 degrees C than comparable groups stored at 25 degrees C.

  14. Peptide-based biocoatings for corrosion protection of stainless steel biomaterial in a chloride solution.

    PubMed

    Muruve, Noah G G; Cheng, Y Frank; Feng, Yuanchao; Liu, Tao; Muruve, Daniel A; Hassett, Daniel J; Irvin, Randall T

    2016-11-01

    In this work, PEGylated D-amino acid K122-4 peptide (D-K122-4-PEG), derived from the type IV pilin of Pseudomonas aeruginosa, coated on 304 stainless steel was investigated for its corrosion resistant properties in a sodium chloride solution by various electrochemical measurements, surface characterization and molecular dynamics simulation. As a comparison, stainless steel electrodes coated with non-PEGylated D-amino acid retroinverso peptide (RI-K122-4) and D-amino acid K122-4 peptide (D-K122-4) were used as control variables during electrochemical tests. It was found that the D-K122-4-PEG coating is able to protect the stainless steel from corrosion in the solution. The RI-K122-4 coating shows corrosion resistant property and should be investigated further, while the D-K122-4 peptide coating, in contrast, shows little to no effect on corrosion. The morphological characterizations support the corrosion resistance of D-K122-4-PEG on stainless steel. The adsorption of D-K122-4 molecules occurs preferentially on Fe2O3, rather than Cr2O3, present on the stainless steel surface.

  15. Peptide-based biocoatings for corrosion protection of stainless steel biomaterial in a chloride solution.

    PubMed

    Muruve, Noah G G; Cheng, Y Frank; Feng, Yuanchao; Liu, Tao; Muruve, Daniel A; Hassett, Daniel J; Irvin, Randall T

    2016-11-01

    In this work, PEGylated D-amino acid K122-4 peptide (D-K122-4-PEG), derived from the type IV pilin of Pseudomonas aeruginosa, coated on 304 stainless steel was investigated for its corrosion resistant properties in a sodium chloride solution by various electrochemical measurements, surface characterization and molecular dynamics simulation. As a comparison, stainless steel electrodes coated with non-PEGylated D-amino acid retroinverso peptide (RI-K122-4) and D-amino acid K122-4 peptide (D-K122-4) were used as control variables during electrochemical tests. It was found that the D-K122-4-PEG coating is able to protect the stainless steel from corrosion in the solution. The RI-K122-4 coating shows corrosion resistant property and should be investigated further, while the D-K122-4 peptide coating, in contrast, shows little to no effect on corrosion. The morphological characterizations support the corrosion resistance of D-K122-4-PEG on stainless steel. The adsorption of D-K122-4 molecules occurs preferentially on Fe2O3, rather than Cr2O3, present on the stainless steel surface. PMID:27524070

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

    NASA Astrophysics Data System (ADS)

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

    2015-11-01

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

  17. Adrenomedullin increases the short-circuit current in the rat prostate: Receptors, chloride channels, the effects of cAMP and calcium ions and implications on fluid secretion.

    PubMed

    Liao, S B; Cheung, K H; Cheung, M P L; Wong, P F; O, W S; Tang, F

    2014-05-01

    In this study, we have investigated the effects of adrenomedullin on chloride and fluid secretion in the rat prostate. The presence of adrenomedullin (ADM) in rat prostate was confirmed using immunostaining, and the molecular species was determined using gel filtration chromatography coupled with an enzyme-linked assay for ADM. The effects of ADM on fluid secretion were studied by short-circuit current technique in a whole mount preparation of the prostate in an Ussing chamber. The results indicated that the ADM level was higher in the ventral than the dorso-lateral prostate and the major molecular species was the active peptide. ADM increased the short-circuit current through both the cAMP- and calcium-activated chloride channels in the ventral lobe, but only through the calcium-activated channels in the dorso-lateral lobe. These stimulatory effects were blocked by the calcitonin gene-related peptide (CGRP) receptor antagonist, hCGRP8-37. We conclude that ADM may regulate prostatic fluid secretion through the chloride channels, which may affect the composition of the seminal plasma bathing the spermatozoa and hence fertility.

  18. Extraction of copper(II) from acid chloride solutions by N-dodecyl- and N,N-dihexylpyridinecarboxamides

    SciTech Connect

    Borowiak-Resterna, A.

    1999-01-01

    N-dodecyl- and N,N-dihexylpyridinecarboxamides with amide group at 2, 3 or 4 position were synthesized. Model individual amides were used to recover copper(II) from chloride solutions at constant water activity and constant total concentration of dissolved species in aqueous solution. It was found, that pyridine-2-carboxamide forms with copper complexes (CuCl{sub 2}){sub x}(Ext){sub 2}. Remaining amides form with copper complexes CuCl{sub 2}(Ext){sub 2}. Monoalkylamides are not suitable for extraction because they and their complexes are slightly soluble in the hydrocarbon diluents. N,N-dialkylpyridinecarboxamides and their copper complexes are sufficiently soluble in the hydrocarbon phase to carry out extraction. However, they are strong extractants and extract efficiently copper already from dilute chloride solutions ([Cl{sup {minus}}] = 0.1 M). They extract also significant amounts of copper from concentrated (3--4 M) nitrate solutions.

  19. Four basic residues critical for the ion selectivity and pore blocker sensitivity of TMEM16A calcium-activated chloride channels.

    PubMed

    Peters, Christian J; Yu, Haibo; Tien, Jason; Jan, Yuh Nung; Li, Min; Jan, Lily Yeh

    2015-03-17

    TMEM16A (transmembrane protein 16) (Anoctamin-1) forms a calcium-activated chloride channel (CaCC) that regulates a broad array of physiological properties in response to changes in intracellular calcium concentration. Although known to conduct anions according to the Eisenman type I selectivity sequence, the structural determinants of TMEM16A anion selectivity are not well-understood. Reasoning that the positive charges on basic residues are likely contributors to anion selectivity, we performed whole-cell recordings of mutants with alanine substitution for basic residues within the putative pore region and identified four residues on four different putative transmembrane segments that significantly increased the permeability of the larger halides and thiocyanate relative to that of chloride. Because TMEM16A permeation properties are known to shift with changes in intracellular calcium concentration, we further examined the calcium dependence of anion selectivity. We found that WT TMEM16A but not mutants with alanine substitution at those four basic residues exhibited a clear decline in the preference for larger anions as intracellular calcium was increased. Having implicated these residues as contributing to the TMEM16A pore, we scrutinized candidate small molecules from a high-throughput CaCC inhibitor screen to identify two compounds that act as pore blockers. Mutations of those four putative pore-lining basic residues significantly altered the IC50 of these compounds at positive voltages. These findings contribute to our understanding regarding anion permeation of TMEM16A CaCC and provide valuable pharmacological tools to probe the channel pore.

  20. Transmitter secretion in the frog neuromuscular synapse after prolonged exposure to calcium-free solutions.

    PubMed

    Zefirov, A L; Mukhamedzyanov, R D; Minlebaev, M G; Cheranov, S Yu; Abdrakhmanov, M M; Grigor'ev, P N

    2003-07-01

    Experiments on neuromuscular synapses from frog skin/chest muscle preparations in conditions of extracellular recording addressed changes in the spontaneous and evoked transmitter secretion after long-term (1.5-6 h) maintenance of preparations in calcium-free solution containing EGTA. Use of three microelectrodes for recording of single-quantum postsynaptic signals showed that calcium-free solution altered the characteristic topography of transmitter secretion in nerve terminals, with widening and fusion of groups of transmitter release. These changes persisted after preparations were returned to the initial solution. These data suggest that calcium-free solutions lead to disorganization of the active zones of nerve endings, At initially low extracellular Ca ion concentrations (0.15-0.4 mM), disorganization of active zones induced by prolonged maintenance of preparations in calcium-free solutions led to decreases in the mean amplitude of endplate currents (EPC) because of decreases in their quantum composition, increases in the time course of transmitter secretion, and decreases in the frequency of miniature endplate currents. The relationship between quantum composition of EPC and the extracellular Ca ion concentration showed a sharp displacement towards higher concentrations, without significant changes in the slope of the relationship. At high initial Ca concentrations (1.8 mM), long-term exposure to calcium-free solutions led to a less marked decrease in EPC amplitude. It is suggested that the extra- and intracellular Ca ion concentrations support the maintenance of the characteristic morphofunctional organization of the apparatus responsible for transmitter secretion in frog nerve endings. Disorganization of the active zones leads to disruption of elements involved in transmitter secretion and decreases in the efficiency of secretion.

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

    DOEpatents

    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.

  2. Conformational structure and energetics of 2-methylphenyl(2'-methoxyphenyl)iodonium chloride: evidence for solution clusters.

    PubMed

    Lee, Yong-Sok; Hodoscek, Milan; Chun, Joong-Hyun; Pike, Victor W

    2010-09-10

    Diaryliodonium salts allow the efficient incorporation of cyclotron-produced [(18)F]fluoride ions into electron-rich and electron-deficient arenes to provide potential radiotracers for molecular imaging in vivo with positron emission tomography (PET). This process (ArI(+)Ar'+(18)F(-)→Ar(18)F+Ar'I) is still not well understood mechanistically. To better understand this and similar reactions, it would be valuable to understand the structures of diaryliodonium salts in organic media, where the reactions are typically conducted. In this endeavor, the X-ray structure of a representative iodonium salt, 2-methylphenyl(2'-methoxyphenyl)iodonium chloride (1), was determined. Our X-ray structure analysis showed 1 to have the conformational M-P dimer as the unit cell with hypervalent iodine as a stereogenic center in each conformer. With the ab initio replica path method we constructed the inversion path between the two enantiomers of 1, thereby revealing two additional pairs of enantiomers that are likely to undergo fast interconversion in solution. Also LC-MS of 1 showed the presence of dimeric and tetrameric anion-bridged clusters in weak organic solution. This observation is consistent with the energetics of 1, both as monomeric and dimeric forms in MeCN, calculated at the B3LYP/DGDZVP level. These evidences of the existence of dimeric and higher order clusters of 1 in solution are relevant to achieve a deeper general understanding of the mechanism and outcome of reactions of diaryliodonium salts in organic media with nucleophiles, such as the [(18)F]fluoride ion.

  3. Ion Association versus Ion Interaction Models in Examining Electrolyte Solutions: Application to Calcium Hydroxide Solubility Equilibrium

    ERIC Educational Resources Information Center

    Menéndez, M. Isabel; Borge, Javier

    2014-01-01

    The heterogeneous equilibrium of the solubility of calcium hydroxide in water is used to predict both its solubility product from solubility and solubility values from solubility product when inert salts, in any concentration, are present. Accepting the necessity of including activity coefficients to treat the saturated solution of calcium…

  4. Calcium

    MedlinePlus

    ... milligrams) of calcium each day. Get it from: Dairy products. Low-fat milk, yogurt, cheese, and cottage ... lactase that helps digest the sugar (lactose) in dairy products, and may have gas, bloating, cramps, or ...

  5. Calcium

    MedlinePlus

    ... supplements and fortified foods include gluconate, lactate, and phosphate. Calcium absorption is best when a person consumes ... also interfere with the body's ability to absorb iron and zinc, but this effect is not well ...

  6. 1H NMR and Rheological Studies of the Calcium Induced Gelation Process in Aqueous Low Methoxyl Pectin Solutions

    NASA Astrophysics Data System (ADS)

    Dobies, M.; Kuśmia, S.; Jurga, S.

    2006-07-01

    The 1H NMR relaxometry in combination with water proton spin-spin relaxation time measurements and rheometry have been applied to study the ionic gelation of 1% w/w aqueous low methoxyl pectin solution induced by divalent Ca2+ cations from a calcium chloride solution. The model-free approach to the analysis of 1H NMR relaxometry data has been used to separate the information on the static (β) and dynamic (<τ_c>) behaviour of the systems tested. The 1H NMR results confirm that the average mobility of both water and the pectin molecules is largely dependent on the concentration of the cross-linking agent. The character of this dependency (β,<τc> and T2 vs. CaCl2 concentration) is consistent with the two-stage gelation process of low methoxyl pectin, in which the formation of strongly linked dimer associations (in the range of 0-2.5 mM CaCl2) is followed by the appearance of weak inter-dimer aggregations (for CaCl2≥ 3.5 mM). The presence of the weak gel structure for the sample with 3.5 mM CaCl2 has been confirmed by rheological measurements. Apart from that, the T1 and T2 relaxation times have been found to be highly sensitive to the syneresis phenomenon, which can be useful to monitor the low methoxyl pectin gel network stability.

  7. Effects of chloride, calcium, and dissolved organic carbon on silver toxicity: Comparison between rainbow tout and fathead minnows

    SciTech Connect

    Bury, N.R.; Galvez, F.; Wood, C.M.

    1999-01-01

    The effects of independently altering chloride, calcium, and dissolved organic carbon (DOC) on the toxicity of silver were compared between rainbow trout (Oncorhynchus mykiss) and fathead minnows (Pimephales promelas). The 96-h median lethal concentration toxicity tests for both species were performed under the same conditions, within the same containers. In addition, the effect of altering [Cl{sup {minus}}] on silver-induced perturbations to body Na{sup +} influx and gill silver load was studied. Toxicity tests were conducted in synthetic soft water (50 {micro}M Na{sup +}, 50 {micro}M Cl{sup {minus}}, 50 {micro}M Ca{sup 2+}, 0.3 mg DOC/L). The [Cl{sup {minus}}], [Ca{sup 2+}], and [DOC] were adjusted by the addition of NaCl, CaNO{sub 3}, or humic acid, respectively. On the basis of total silver, increasing [Cl{sup {minus}}] over a range of 50 {micro}M to 1,500 {micro}M resulted in a 4.3-fold increase in the 96-h LC50 values (decrease in toxicity) for rainbow trout, but did not significantly affect the 96-h LC50 values for fathead minnows. Increasing water [Ca{sup 2+}] (from 50 to 2,000 {micro}M) had only a small influence on the 96-h LC50 values in both species. If the 96-h LC50 values are calculated on the basis of ionic silver, Ag{sup +}, then, in the case of rainbow trout, toxicity correlates to Ag{sup +}. However, this correlation does not exist for fathead minnows. Increasing [Cl{sup {minus}}] did not affect the degree of perturbation of Na{sup +} influx during acute exposure (first 4 h) to 8 {micro}g Ag/L in either species, nor did it affect the whole-body silver uptake rates, but it did reduce the gill silver load. These results demonstrate that differences exist in the way in which water chemistry ameliorates silver toxicity between rainbow trout and fathead minnows.

  8. On the preparation of TiAl alloy by direct reduction of the oxide mixtures in calcium chloride melt

    SciTech Connect

    Prabhat K. Tripathy; Derek J. Fray

    2011-11-01

    electrode in a pool of molten calcium chloride at a temperature of 9000C. The dominant mechanism of the oxygen removal was the ionization of oxygen followed by its subsequent discharge, as CO2/CO, at the anode surface. The removal of oxygen from the oxide mixture helped form the alloy in situ. The presentation shall cover the detailed experimental results pertaining to the preparation, evaluation and characterization of Ti-47Al-2Nb-2Cr (atom%) alloy.

  9. Precipitation of calcium carbonate in aqueous solutions in presence of ethylene glycol and dodecane.

    NASA Astrophysics Data System (ADS)

    Natsi, Panagiota D.; Rokidi, Stamatia; Koutsoukos, Petros G.

    2015-04-01

    The formation of calcium carbonate (CaCO3) in aqueous supersaturated solutions has been intensively studied over the past decades, because of its significance for a number of processes of industrial and environmental interest. In the oil and gas production industry the deposition of calcium carbonate affects adversely the productivity of the wells. Calcium carbonate scale deposits formation causes serious problems in water desalination, CO2 sequestration in subsoil wells, in geothermal systems and in heat exchangers because of the low thermal coefficient of the salt. Amelioration of the operational conditions is possible only when the mechanisms underlying nucleation and crystal growth of calcium carbonate in the aqueous fluids is clarified. Given the fact that in oil production processes water miscible and immiscible hydrocarbons are present the changes of the dielectric constant of the fluid phase has serious impact in the kinetics of calcium carbonate precipitation, which remains largely unknown. The problem becomes even more complicated if polymorphism exhibited by calcium carbonate is also taken into consideration. In the present work, the stability of aqueous solutions supersaturated with respect to all calcium carbonate polymorphs and the subsequent kinetics of calcium carbonate precipitation were measured. The measurements included aqueous solutions and solutions in the presence of water miscible (ethylene glycol, MEG) and water immiscible organics (n-dodecane). All measurements were done at conditions of sustained supersaturation using the glass/ Ag/AgCl combination electrode as a probe of the precipitation and pH as the master variable for the addition of titrant solutions with appropriate concentration needed to maintenance the solution supersaturation. Initially, the metastable zone width was determined from measurements of the effect of the solution supersaturation on the induction time preceding the onset of precipitation at free-drift conditions. The

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

    NASA Astrophysics Data System (ADS)

    Zhang, Zhigang; Duan, Zhenhao

    2004-02-01

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

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

    PubMed

    Santos-Sacchi, Joseph; Song, Lei

    2016-06-01

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

  12. Spontaneous growth of a laminin-apatite nano-composite in a metastable calcium phosphate solution.

    PubMed

    Oyane, Ayako; Uchida, Masaki; Onuma, Kazuo; Ito, Atsuo

    2006-01-01

    We have previously reported that a laminin-apatite composite layer is formed on an ethylene-vinyl alcohol copolymer (EVOH) in a laminin-containing calcium phosphate (LCP) solution. In this work, the stability of the LCP solution and growth process of the laminin-apatite composite layer have been investigated. Dynamic light scattering technique revealed that the LCP solution was stable for periods as long as 24 h; it did not induce homogeneous precipitation of laminin or calcium phosphates in the solution. Analysis of the EVOH surface and the LCP solution showed that the laminin-apatite composite layer was formed via coprecipitation of laminin and apatite on the EVOH plate, i.e., spontaneous growing of apatite and simultaneous immobilization of laminin molecules or laminin-calcium phosphate nano-complexes onto its surface. Transmission electron microscopy also revealed that the laminin molecules in the resulting composite layer were not localized or aggregated, but were dispersed on a nano-scale in the entire layer. Because of this nano-composite structure, a large number of laminin molecules were stably immobilized on the EVOH plate. This may be responsible for the excellent cell adhesion properties of this type of composite material.

  13. Angiotensin II modulates mouse skeletal muscle resting conductance to chloride and potassium ions and calcium homeostasis via the AT1 receptor and NADPH oxidase.

    PubMed

    Cozzoli, Anna; Liantonio, Antonella; Conte, Elena; Cannone, Maria; Massari, Ada Maria; Giustino, Arcangela; Scaramuzzi, Antonia; Pierno, Sabata; Mantuano, Paola; Capogrosso, Roberta Francesca; Camerino, Giulia Maria; De Luca, Annamaria

    2014-10-01

    Angiotensin II (ANG II) plays a role in muscle wasting and remodeling; however, little evidence shows its direct effects on specific muscle functions. We presently investigated the acute in vitro effects of ANG II on resting ionic conductance and calcium homeostasis of mouse extensor digitorum longus (EDL) muscle fibers, based on previous findings that in vivo inhibition of ANG II counteracts the impairment of macroscopic ClC-1 chloride channel conductance (gCl) in the mdx mouse model of muscular dystrophy. By means of intracellular microelectrode recordings we found that ANG II reduced gCl in the nanomolar range and in a concentration-dependent manner (EC50 = 0.06 μM) meanwhile increasing potassium conductance (gK). Both effects were inhibited by the ANG II receptors type 1 (AT1)-receptor antagonist losartan and the protein kinase C inhibitor chelerythrine; no antagonism was observed with the AT2 antagonist PD123,319. The scavenger of reactive oxygen species (ROS) N-acetyl cysteine and the NADPH-oxidase (NOX) inhibitor apocynin also antagonized ANG II effects on resting ionic conductances; the ANG II-dependent gK increase was blocked by iberiotoxin, an inhibitor of calcium-activated potassium channels. ANG II also lowered the threshold for myofiber and muscle contraction. Both ANG II and the AT1 agonist L162,313 increased the intracellular calcium transients, measured by fura-2, with a two-step pattern. These latter effects were not observed in the presence of losartan and of the phospholipase C inhibitor U73122 and the in absence of extracellular calcium, disclosing a Gq-mediated calcium entry mechanism. The data show for the first time that the AT1-mediated ANG II pathway, also involving NOX and ROS, directly modulates ion channels and calcium homeostasis in adult myofibers.

  14. Angiotensin II modulates mouse skeletal muscle resting conductance to chloride and potassium ions and calcium homeostasis via the AT1 receptor and NADPH oxidase

    PubMed Central

    Cozzoli, Anna; Liantonio, Antonella; Conte, Elena; Cannone, Maria; Massari, Ada Maria; Giustino, Arcangela; Scaramuzzi, Antonia; Pierno, Sabata; Mantuano, Paola; Capogrosso, Roberta Francesca; Camerino, Giulia Maria

    2014-01-01

    Angiotensin II (ANG II) plays a role in muscle wasting and remodeling; however, little evidence shows its direct effects on specific muscle functions. We presently investigated the acute in vitro effects of ANG II on resting ionic conductance and calcium homeostasis of mouse extensor digitorum longus (EDL) muscle fibers, based on previous findings that in vivo inhibition of ANG II counteracts the impairment of macroscopic ClC-1 chloride channel conductance (gCl) in the mdx mouse model of muscular dystrophy. By means of intracellular microelectrode recordings we found that ANG II reduced gCl in the nanomolar range and in a concentration-dependent manner (EC50 = 0.06 μM) meanwhile increasing potassium conductance (gK). Both effects were inhibited by the ANG II receptors type 1 (AT1)-receptor antagonist losartan and the protein kinase C inhibitor chelerythrine; no antagonism was observed with the AT2 antagonist PD123,319. The scavenger of reactive oxygen species (ROS) N-acetyl cysteine and the NADPH-oxidase (NOX) inhibitor apocynin also antagonized ANG II effects on resting ionic conductances; the ANG II-dependent gK increase was blocked by iberiotoxin, an inhibitor of calcium-activated potassium channels. ANG II also lowered the threshold for myofiber and muscle contraction. Both ANG II and the AT1 agonist L162,313 increased the intracellular calcium transients, measured by fura-2, with a two-step pattern. These latter effects were not observed in the presence of losartan and of the phospholipase C inhibitor U73122 and the in absence of extracellular calcium, disclosing a Gq-mediated calcium entry mechanism. The data show for the first time that the AT1-mediated ANG II pathway, also involving NOX and ROS, directly modulates ion channels and calcium homeostasis in adult myofibers. PMID:25080489

  15. Variomics screen identifies the re-entrant loop of the calcium-activated chloride channel ANO1 that facilitates channel activation.

    PubMed

    Bill, Anke; Popa, M Oana; van Diepen, Michiel T; Gutierrez, Abraham; Lilley, Sarah; Velkova, Maria; Acheson, Kathryn; Choudhury, Hedaythul; Renaud, Nicole A; Auld, Douglas S; Gosling, Martin; Groot-Kormelink, Paul J; Gaither, L Alex

    2015-01-01

    The calcium-activated chloride channel ANO1 regulates multiple physiological processes. However, little is known about the mechanism of channel gating and regulation of ANO1 activity. Using a high-throughput, random mutagenesis-based variomics screen, we generated and functionally characterized ∼6000 ANO1 mutants and identified novel mutations that affected channel activity, intracellular trafficking, or localization of ANO1. Mutations such as S741T increased ANO1 calcium sensitivity and rendered ANO1 calcium gating voltage-independent, demonstrating a critical role of the re-entrant loop in coupling calcium and voltage sensitivity of ANO1 and hence in regulating ANO1 activation. Our data present the first unbiased and comprehensive study of the structure-function relationship of ANO1. The novel ANO1 mutants reported have diverse functional characteristics, providing new tools to study ANO1 function in biological systems, paving the path for a better understanding of the function of ANO1 and its role in health and diseases.

  16. Variomics Screen Identifies the Re-entrant Loop of the Calcium-activated Chloride Channel ANO1 That Facilitates Channel Activation*

    PubMed Central

    Bill, Anke; Popa, M. Oana; van Diepen, Michiel T.; Gutierrez, Abraham; Lilley, Sarah; Velkova, Maria; Acheson, Kathryn; Choudhury, Hedaythul; Renaud, Nicole A.; Auld, Douglas S.; Gosling, Martin; Groot-Kormelink, Paul J.; Gaither, L. Alex

    2015-01-01

    The calcium-activated chloride channel ANO1 regulates multiple physiological processes. However, little is known about the mechanism of channel gating and regulation of ANO1 activity. Using a high-throughput, random mutagenesis-based variomics screen, we generated and functionally characterized ∼6000 ANO1 mutants and identified novel mutations that affected channel activity, intracellular trafficking, or localization of ANO1. Mutations such as S741T increased ANO1 calcium sensitivity and rendered ANO1 calcium gating voltage-independent, demonstrating a critical role of the re-entrant loop in coupling calcium and voltage sensitivity of ANO1 and hence in regulating ANO1 activation. Our data present the first unbiased and comprehensive study of the structure-function relationship of ANO1. The novel ANO1 mutants reported have diverse functional characteristics, providing new tools to study ANO1 function in biological systems, paving the path for a better understanding of the function of ANO1 and its role in health and diseases. PMID:25425649

  17. Constant-distance mode scanning potentiometry. 1. Visualization of calcium carbonate dissolution in aqueous solution.

    PubMed

    Etienne, Mathieu; Schulte, Albert; Mann, Stefan; Jordan, Guntram; Dietzel, Irmgard D; Schuhmann, Wolfgang

    2004-07-01

    Constant-distance mode scanning potentiometry was established by integrating potentiometric microsensors as ion-selective scanning probes into a SECM setup that was equipped with a piezoelectric shear force-based tip-to-sample distance control. The combination of specially designed micrometer-sized potentiometric tips with an advanced system for tip positioning allowed simultaneous acquisition of both topographic and potentiometric information at solid/liquid interfaces with high spatial resolution. The performance of the approach was evaluated by applying Ca(2+)-selective constant-distance mode potentiometry to monitor the dissolution of calcium carbonate occurring either at the (104) surface of calcite crystals or in proximity to the more complex surface of cross sections of a calcium carbonate shell of Mya arenaria exposed to slightly acidic aqueous solutions. Micrometer-scale heterogeneities in the apparent calcium activity profiles have successfully been resolved for both samples.

  18. Removal of phosphate from solution by adsorption and precipitation of calcium phosphate onto monohydrocalcite.

    PubMed

    Yagi, Shintaro; Fukushi, Keisuke

    2012-10-15

    The sorption behavior and mechanism of phosphate on monohydrocalcite (CaCO(3)·H(2)O: MHC) were examined using batch sorption experiments as a function of phosphate concentrations, ionic strengths, temperatures, and reaction times. The mode of PO(4) sorption is divisible into three processes depending on the phosphate loading. At low phosphate concentrations, phosphate is removed by coprecipitation of phosphate during the transformation of MHC to calcite. The sorption mode at the low-to-moderate phosphate concentrations is most likely an adsorption process because the sorption isotherm at the conditions can be fitted reasonably with the Langmuir equation. The rapid sorption kinetics at the conditions is also consistent with the adsorption reaction. The adsorption of phosphate on MHC depends strongly on ionic strength, but slightly on temperature. The maximum adsorption capacities of MHC obtained from the regression of the experimental data to the Langmuir equation are higher than those reported for stable calcium carbonate (calcite or aragonite) in any conditions. At high phosphate concentrations, the amount of sorption deviates from the Langmuir isotherm, which can fit the low-to-moderate phosphate concentrations. Speciation-saturation analyses of the reacted solutions at the conditions indicated that the solution compositions which deviate from the Langmuir equation are supersaturated with respect to a certain calcium phosphate. The obtained calcium phosphate is most likely amorphous calcium phosphate (Ca(3)(PO(4))(2)·xH(2)O). The formation of the calcium phosphate depends strongly on ionic strength, temperature, and reaction times. The solubility of MHC is higher than calcite and aragonite because of its metastability. Therefore, the higher solubility of MHC facilitates the formation of the calcium phosphates more than with calcite and aragonite.

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

    SciTech Connect

    Baker, Gary A; Heller, William T

    2009-01-01

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

  20. Structure and corrosive wear resistance of plasma-nitrided alloy steels in 3% sodium chloride solutions

    SciTech Connect

    Lee, C.K.; Shih, H.C. . Dept. of Materials Science and Engineering)

    1994-11-01

    Type 304 stainless steel (SS), type 410 SS, and type 4140 low-alloy steel were plasma nitrided in a commercial furnace at 560 C for 50 h. Microstructure and the composition of the nitrided layer were analyzed. The resistance to corrosive wear was evaluated by a tribotest in which the specimen was held under potentiostatic control at anodic and cathodic potentials in 3% sodium chloride solution (pH 6.8). Electrochemical polarization measurements were made, and the surface morphology and composition after corrosive wear were examined. Wear rates at cathodic potentials were very low, but significant weight losses were observed as the applied potentials were increased anodically. The coefficient of friction varied in a fashion similar to the wear rate. For the untreated alloys, the magnitude of the wear rate and coefficient of friction decreased as follows: type 4140 alloy > type 41 SS > type 304 SS. For the plasma-nitrided alloys, the ranking was: type 304 SS > type 410 SS. type 4140 alloy. Plasma nitriding was shown to be beneficial to the corrosive wear resistance of type 4140 alloy, but an adverse effect was obtained for types 304 and 410 SS. These findings could be interpreted in terms of the electrochemical polarization characteristics of a static specimen and were strongly related to the subtleties of the nitrided microstructures. The stable chromium nitride (CrN) segregated in the [gamma]-iron (type 304 SS) and [alpha]-Fe (type 41 SS) matrices and resulted in a pitting and spalling type of corrosive wear mechanism. The phases [epsilon]-(Fe, Cr)[sub 2-3]N and [gamma]-(Fe, Cr)[sub 4]N enriched in the surface layer of nitrided type 4140 alloy provided excellent corrosive wear resistance.

  1. Identical flow injection spectrophotometric manifold for determination of protein, phosphorus, calcium, chloride, copper, manganese, iron, and zinc in feeds or premixes.

    PubMed

    Liu, J F; Feng, Y D; Jiang, G B

    2001-01-01

    A simple procedure using an identical manifold was developed for determination of nitrogen (protein) phosphorus, calcium, chloride, copper, manganese, iron, and zinc in feeds and feedstuffs. By changing appropriate reagents and detection wavelength, these 8 elements were determined successively with a simple identical double-line flow injection (FI) manifold. Fl spectrophotometric determinations were made by the blue indophenol reaction for ammonium, the molybdenum blue method for phosphate, the cresolphthalein complexone procedure for calcium, and the mercuric thiocyanate procedure for chloride. The chromogenic reagents for copper, iron, manganese, and zinc determination were bis(cyclohexanone)oxalydihydrazone (Cuprizone), 1,10-phenanthroline, formaldoxime, and xylenol orange, respectively. Sample digestion catalyst, Fl manifold, and some chemical parameters were optimized. The proposed procedure had a sampling rate of 90/h for each analyte. The determination ranges (mg/L) were 10-60 for N, 1-15 for P and Ca, 540 for Cl, and 0.5-15 for Cu, Fe, Mn, and Zn, respectively. Results of the analyses of animal feed and feedstuff samples by this procedure did not differ significantly from those obtained by proven manual methods.

  2. 21 CFR 184.1191 - Calcium carbonate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... soda process”; (2) By precipitation of calcium carbonate from calcium hydroxide in the “Carbonation process”; or (3) By precipitation of calcium carbonate from calcium chloride in the “Calcium...

  3. 21 CFR 184.1191 - Calcium carbonate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... soda process”; (2) By precipitation of calcium carbonate from calcium hydroxide in the “Carbonation process”; or (3) By precipitation of calcium carbonate from calcium chloride in the “Calcium...

  4. 21 CFR 184.1191 - Calcium carbonate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... soda process”; (2) By precipitation of calcium carbonate from calcium hydroxide in the “Carbonation process”; or (3) By precipitation of calcium carbonate from calcium chloride in the “Calcium...

  5. 21 CFR 184.1191 - Calcium carbonate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... soda process”; (2) By precipitation of calcium carbonate from calcium hydroxide in the “Carbonation process”; or (3) By precipitation of calcium carbonate from calcium chloride in the “Calcium...

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

    NASA Astrophysics Data System (ADS)

    Sherif, El-Sayed M.

    2010-08-01

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

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

    SciTech Connect

    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.

  8. Optical Properties of Sodium Chloride Solution Within the Spectral Range from 300 to 2500 nm at Room Temperature.

    PubMed

    Li, Xingcan; Liu, Linhua; Zhao, Junming; Tan, Jianyu

    2015-05-01

    The optical properties of sodium chloride (NaCl) solution were experimentally determined by double optical pathlength transmission method in the spectral range from 300 to 2500 nm at the NaCl concentration range from 0 to 360 g/L. The results show that the refractive index of NaCl solution increases with NaCl concentrations and correlates nonlinearly with the concentration of NaCl solution. The absorption index of NaCl solution increases with NaCl concentrations in the visible spectral range of 300-700 nm, but varies little in the near-infrared spectral range of 700-2500 nm at room temperature. For the sake of applications, the fitted formulae of the refractive index and absorption index of NaCl solution as a function of wavelength and NaCl concentration are presented.

  9. Aqueous solutions of calcium ions: hydration numbers and the effect of temperature.

    PubMed

    Zavitsas, Andreas A

    2005-11-01

    Hydration numbers of calcium ions are determined from extensive measurements of colligative properties of water solutions of calcium salts. The hydration numbers reported refer to the average number of water molecules that are bound sufficiently strongly to calcium ions so as to be removed from the solvent and become part of the solute. Contrary to common descriptions of deviations from ideal behavior for concentrated solutions, ideal behavior is demonstrated when mole fractions are calculated by taking account of such bound water. Measurements over wide concentration and temperature ranges are used to obtain the effect of temperature on the average hydration number of Ca(2+). Freezing point depression measurements yield a hydration number of 12.0 +/- 0.8. Boiling point elevations yield 6.7 +/- 0.6. Consistent with this, vapor pressure measurements from 0 to 200 degrees C show a gradual decrease in hydration number with increasing temperature, with a value of 5.0 at 200 degrees C. PMID:16853671

  10. Three-Day-Old Human Unfertilized Oocytes after In Vitro Fertilization/Intracytoplasmic Sperm Injection Can Be Activated by Calcium Ionophore A23187 or Strontium Chloride and Develop to Blastocysts

    PubMed Central

    Han, Xiao-jie; Liu, Ming-hui; Wang, Shu-yu; Jia, Chan-wei; Yu, Lan; Ren, Guoqing; Wang, Li; Li, Wei

    2014-01-01

    Abstract Our objective was to observe the effectiveness of the calcium ionophore A23187 or strontium chloride on the activation and subsequent embryonic development of 3-day-old human unfertilized oocytes after in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI). A total of 279 3-day-old unfertilized oocytes after IVF or ICSI were randomized to be activated by the calcium ionophore A23187 (n=138) or strontium chloride (n=141). The activated oocytes were cultured in vitro for 3–5 days. Activation rate, pronucleus formation, cleavage rate, and developmental potential of parthenotes during culture were evaluated. A total of 170 unfertilized oocytes were activated; 65 developed to cleavage stage, 19 developed to greater than the eight-cell stage, and five blastocysts were obtained. The activation rate of the calcium ionophore A23187 group was higher than that of the strontium chloride group (75.4% and 46.8%, respectively; p<0.05); there was significant difference between two groups (p<0.05). Among the 44 cleaved oocytes in the calcium ionophore A23187 group, eight developed to the two- to four-cell stage, 17 developed to the five- to eight-cell stage, 15 developed to greater than the eight-cell stage, and four blastocysts were obtained. Among the 21 cleaved oocytes in the strontium chloride group, six developed to the two- to four- cell stage, 10 developed to the five- to eight-cell stage, four developed to greater than the eight-cell stage, and one blastocyst was obtained. Three-day-old unfertilized human oocytes after IVF or ICSI could be activated by the calcium ionophore A23187 or strontium chloride, and a small part of parthenogenetic embryos developed into blastocysts. The treatment with the calcium ionophore A23187 was better than that of strontium chloride in respect to the activation rate of 3-day-old unfertilized human oocytes after IVF or ICSI. PMID:24960285

  11. Three-day-old human unfertilized oocytes after in vitro fertilization/intracytoplasmic sperm injection can be activated by calcium ionophore a23187 or strontium chloride and develop to blastocysts.

    PubMed

    Liu, Ying; Han, Xiao-Jie; Liu, Ming-Hui; Wang, Shu-Yu; Jia, Chan-Wei; Yu, Lan; Ren, Guoqing; Wang, Li; Li, Wei

    2014-08-01

    Our objective was to observe the effectiveness of the calcium ionophore A23187 or strontium chloride on the activation and subsequent embryonic development of 3-day-old human unfertilized oocytes after in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI). A total of 279 3-day-old unfertilized oocytes after IVF or ICSI were randomized to be activated by the calcium ionophore A23187 (n=138) or strontium chloride (n=141). The activated oocytes were cultured in vitro for 3-5 days. Activation rate, pronucleus formation, cleavage rate, and developmental potential of parthenotes during culture were evaluated. A total of 170 unfertilized oocytes were activated; 65 developed to cleavage stage, 19 developed to greater than the eight-cell stage, and five blastocysts were obtained. The activation rate of the calcium ionophore A23187 group was higher than that of the strontium chloride group (75.4% and 46.8%, respectively; p<0.05); there was significant difference between two groups (p<0.05). Among the 44 cleaved oocytes in the calcium ionophore A23187 group, eight developed to the two- to four-cell stage, 17 developed to the five- to eight-cell stage, 15 developed to greater than the eight-cell stage, and four blastocysts were obtained. Among the 21 cleaved oocytes in the strontium chloride group, six developed to the two- to four- cell stage, 10 developed to the five- to eight-cell stage, four developed to greater than the eight-cell stage, and one blastocyst was obtained. Three-day-old unfertilized human oocytes after IVF or ICSI could be activated by the calcium ionophore A23187 or strontium chloride, and a small part of parthenogenetic embryos developed into blastocysts. The treatment with the calcium ionophore A23187 was better than that of strontium chloride in respect to the activation rate of 3-day-old unfertilized human oocytes after IVF or ICSI.

  12. Method for calcining nuclear waste solutions containing zirconium and halides

    DOEpatents

    Newby, Billie J.

    1979-01-01

    A reduction in the quantity of gelatinous solids which are formed in aqueous zirconium-fluoride nuclear reprocessing waste solutions by calcium nitrate added to suppress halide volatility during calcination of the solution while further suppressing chloride volatility is achieved by increasing the aluminum to fluoride mole ratio in the waste solution prior to adding the calcium nitrate.

  13. Gravimetric Determination of Calcium as Calcium Carbonate Hydrate.

    ERIC Educational Resources Information Center

    Henrickson, Charles H.; Robinson, Paul R.

    1979-01-01

    The gravimetric determination of calcium as calcium carbonate is described. This experiment is suitable for undergraduate quantitative analysis laboratories. It is less expensive than determination of chloride as silver chloride. (BB)

  14. Intermediate-conductance calcium-activated potassium channel KCa3.1 and chloride channel modulate chemokine ligand (CCL19/CCL21)-induced migration of dendritic cells.

    PubMed

    Shao, Zhifei; Gaurav, Rohit; Agrawal, Devendra K

    2015-07-01

    The role of ion channels is largely unknown in chemokine-induced migration in nonexcitable cells such as dendritic cells (DCs). Here, we examined the role of intermediate-conductance calcium-activated potassium channel (KCa3.1) and chloride channel (CLC3) in lymphatic chemokine-induced migration of DCs. The amplitude and kinetics of chemokine ligand (CCL19/CCL21)-induced Ca(2+) influx were associated with chemokine receptor 7 expression levels, extracellular-free Ca(2+) and Cl(-), and independent of extracellular K(+). Chemokines (CCL19 and CCL21) and KCa3.1 activator (1-ethyl-1,3-dihydro-2H-benzimidazol-2-one) induced plasma membrane hyperpolarization and K(+) efflux, which was blocked by 1-[(2-chlorophenyl)diphenylmethyl]-1H-pyrazole, suggesting that KCa3.1 carried larger conductance than the inward calcium release-activated calcium channel. Blockade of KCa3.1, low Cl(-) in the medium, and low dose of 4,4'-diisothiocyano-2,2'-stilbenedisulfonic acid (DIDS) impaired CCL19/CCL21-induced Ca(2+) influx, cell volume change, and DC migration. High doses of DIDS completely blocked DC migration possibly by significantly disrupting mitochondrial membrane potential. In conclusion, KCa3.1 and CLC3 are critical in human DC migration by synergistically regulating membrane potential, chemokine-induced Ca(2+) influx, and cell volume.

  15. Effect of benzalkonium chloride-free latanoprost ophthalmic solution on ocular surface in patients with glaucoma

    PubMed Central

    Walimbe, Tejaswini; Chelerkar, Vidya; Bhagat, Purvi; Joshi, Abhijeet; Raut, Atul

    2016-01-01

    Introduction Benzalkonium chloride (BAK), included as a preservative in many topical treatments for glaucoma, induces significant toxicity and alters tear breakup time (TBUT). BAK-containing latanoprost, an ester prodrug of prostaglandin F2α, can cause ocular adverse events (AEs) associated with BAK. The purpose of this study was to evaluate the efficacy and safety of BAK-free latanoprost. Patients and methods A prospective, open-label, single-arm, multicenter, 8-week study in patients with primary open-angle glaucoma or ocular hypertension taking BAK-containing latanoprost for ≥12 months was performed. Patients were switched to BAK-free latanoprost ophthalmic solution 0.005% administered once daily, and eyes were assessed after 28 and 56 days. Primary efficacy and safety variables were TBUT and treatment-emergent AEs, respectively. Results At day 56, 40 eyes were evaluable. Mean TBUT increased significantly from baseline (3.67±1.60 seconds) to 5.03±2.64 and 6.06±3.39 seconds after 28 and 56 days of treatment with BAK-free latanoprost (P<0.0001). Ocular Surface Disease Index© (OSDI©) score also decreased significantly to 12.06±13.40 and 7.06±10.75 at 28 and 56 days, respectively, versus baseline (18.09±18.61, P<0.0001). In addition, inferior corneal staining score decreased significantly to 0.53 from baseline (0.85, P=0.0033). A reduction in conjunctival hyperemia and intraocular pressure was observed at both time points. No treatment-related serious AEs were evident and 12 (26.08%) treatment-emergent AEs occurred in seven patients, with eye pain and irritation being the most frequent. No clinically significant changes in vital signs or slit lamp examinations were observed. Conclusion Results indicate that switching from BAK-containing latanoprost to BAK-free latanoprost resulted in significant improvements in TBUT, OSDI© score, and inferior corneal staining score, and measurable reductions in conjunctival hyperemia score. Furthermore, BAK

  16. Effect of calcium on solution and conformational characteristics of polysaccharide from seeds of Plantago asiatica L.

    PubMed

    Yin, Jun-Yi; Nie, Shao-Ping; Guo, Qing-Bin; Wang, Qi; Cui, Steve W; Xie, Ming-Yong

    2015-06-25

    Polysaccharide from seeds of Plantago asiatica L. is rich in calcium, which is important for keeping viscous and weak gelling properties of the polysaccharide. However, few studies reported effect of calcium on solution and conformational characteristics of the polysaccharide. In this study, polysaccharide was prepared from seeds of P. asiatica L. and named as PLCP. PLCP was treated with EDTA to remove calcium ion to get PLCP-E. PLCP and PLCP-E were characterized by Ubbelohde capillary viscometer, light scattering and HPSEC with refractive index, light scattering and viscometric detectors. The results showed that PLCP had much higher intrinsic viscosity, hydrodynamic radius (Rh), radius of gyration (Rg) and molecular weight than that of PLCP-E when measured in the same solvent. PLCP and PLCP-E were in random coil conformation in aqueous solutions according to light scattering and HPSEC measurements. HPSEC data showed PLCP-E had lower intrinsic viscosity than that of PLCP with the same molecular weight. Persistence length of Lp was 2.5nm for PLCP and 2.3nm for PLCP-E, respectively. In conclusion, PLCP exhibited higher intrinsic viscosity and molecular weight, and stiffer conformation than that of PLCP-E, which could explain the reason of higher viscosity of PLCP. PMID:25839827

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

    SciTech Connect

    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{sub 2}){sup {minus}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.

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

    NASA Astrophysics Data System (ADS)

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

    2016-06-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2016-07-01

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

  20. Dehydration and crystallization of amorphous calcium carbonate in solution and in air.

    PubMed

    Ihli, Johannes; Wong, Wai Ching; Noel, Elizabeth H; Kim, Yi-Yeoun; Kulak, Alexander N; Christenson, Hugo K; Duer, Melinda J; Meldrum, Fiona C

    2014-01-01

    The mechanisms by which amorphous intermediates transform into crystalline materials are poorly understood. Currently, attracting enormous interest is the crystallization of amorphous calcium carbonate, a key intermediary in synthetic, biological and environmental systems. Here we attempt to unify many contrasting and apparently contradictory studies by investigating this process in detail. We show that amorphous calcium carbonate can dehydrate before crystallizing, both in solution and in air, while thermal analyses and solid-state nuclear magnetic resonance measurements reveal that its water is present in distinct environments. Loss of the final water fraction--comprising less than 15% of the total--then triggers crystallization. The high activation energy of this step suggests that it occurs by partial dissolution/recrystallization, mediated by surface water, and the majority of the particle then crystallizes by a solid-state transformation. Such mechanisms are likely to be widespread in solid-state reactions and their characterization will facilitate greater control over these processes.

  1. Heterogeneous nucleation of calcium phosphates on solid surfaces in aqueous solution.

    PubMed

    Wu, W; Zhuang, H; Nancollas, G H

    1997-04-01

    The heterogeneous nucleation of calcium phosphates on solid surfaces of poly(methyl methacrylate) (PMMA), poly-(tetrafluoroethylene-co-hexafluoropropylene) (FEP), silicone rubber, mica, and radiofrequency glow discharge (RFGD)-treated PMMA, FEP, and silicone rubber has been studied in solutions supersaturated with respect to hydroxyapatite. The surface properties of the substrates were characterized by contact angle measurements. For the RFGD-treated surfaces, the Lifshitz-Van der Waals surface tension component changes very little, but the Lewis acid-base surface tension parameters vary greatly depending upon the materials. With scanning electron microscopy, nucleation of calcium phosphates was observed only on the surfaces: mica, RFGD-treated PMMA and FEP, with relatively high values of the Lewis base surface tension parameter. The more hydrophobic surfaces having low Lewis acid-base surface tensions, untreated PMMA and FEP, silicone rubber, and even RFGD-treated silicone rubber showed no nucleation.

  2. Infrared optical constants of crystalline sodium chloride dihydrate: application to study the crystallization of aqueous sodium chloride solution droplets at low temperatures.

    PubMed

    Wagner, Robert; Möhler, Ottmar; Schnaiter, Martin

    2012-08-23

    Complex refractive indices of sodium chloride dihydrate, NaCl·2H(2)O, have been retrieved in the 6000-800 cm(-1) wavenumber regime from the infrared extinction spectra of crystallized aqueous NaCl solution droplets. The data set is valid in the temperature range from 235 to 216 K and was inferred from crystallization experiments with airborne particles performed in the large coolable aerosol and cloud chamber AIDA at the Karlsruhe Institute of Technology. The retrieval concept was based on the Kramers-Kronig relationship for a complex function of the optical constants n and k whose imaginary part is proportional to the optical depth of a small particle absorption spectrum in the Rayleigh approximation. The appropriate proportionality factor was inferred from a fitting algorithm applied to the extinction spectra of about 1 μm sized particles, which, apart from absorption, also featured a pronounced scattering contribution. NaCl·2H(2)O is the thermodynamically stable crystalline solid in the sodium chloride-water system below the peritectic at 273.3 K; above 273.3 K, the anhydrous NaCl is more stable. In contrast to anhydrous NaCl crystals, the dihydrate particles reveal prominent absorption signatures at mid-infrared wavelengths due to the hydration water molecules. Formation of NaCl·2H(2)O was only detected at temperatures clearly below the peritectic and was first evidenced in a crystallization experiment conducted at 235 K. We have employed the retrieved refractive indices of NaCl·2H(2)O to quantify the temperature dependent partitioning between anhydrous and dihydrate NaCl particles upon crystallization of aqueous NaCl solution droplets. It was found that the temperature range from 235 to 216 K represents the transition regime where the composition of the crystallized particle ensemble changes from almost only NaCl to almost only NaCl·2H(2)O particles. Compared to the findings on the NaCl/NaCl·2H(2)O partitioning from a recent study conducted with micron

  3. Infrared optical constants of crystalline sodium chloride dihydrate: application to study the crystallization of aqueous sodium chloride solution droplets at low temperatures.

    PubMed

    Wagner, Robert; Möhler, Ottmar; Schnaiter, Martin

    2012-08-23

    Complex refractive indices of sodium chloride dihydrate, NaCl·2H(2)O, have been retrieved in the 6000-800 cm(-1) wavenumber regime from the infrared extinction spectra of crystallized aqueous NaCl solution droplets. The data set is valid in the temperature range from 235 to 216 K and was inferred from crystallization experiments with airborne particles performed in the large coolable aerosol and cloud chamber AIDA at the Karlsruhe Institute of Technology. The retrieval concept was based on the Kramers-Kronig relationship for a complex function of the optical constants n and k whose imaginary part is proportional to the optical depth of a small particle absorption spectrum in the Rayleigh approximation. The appropriate proportionality factor was inferred from a fitting algorithm applied to the extinction spectra of about 1 μm sized particles, which, apart from absorption, also featured a pronounced scattering contribution. NaCl·2H(2)O is the thermodynamically stable crystalline solid in the sodium chloride-water system below the peritectic at 273.3 K; above 273.3 K, the anhydrous NaCl is more stable. In contrast to anhydrous NaCl crystals, the dihydrate particles reveal prominent absorption signatures at mid-infrared wavelengths due to the hydration water molecules. Formation of NaCl·2H(2)O was only detected at temperatures clearly below the peritectic and was first evidenced in a crystallization experiment conducted at 235 K. We have employed the retrieved refractive indices of NaCl·2H(2)O to quantify the temperature dependent partitioning between anhydrous and dihydrate NaCl particles upon crystallization of aqueous NaCl solution droplets. It was found that the temperature range from 235 to 216 K represents the transition regime where the composition of the crystallized particle ensemble changes from almost only NaCl to almost only NaCl·2H(2)O particles. Compared to the findings on the NaCl/NaCl·2H(2)O partitioning from a recent study conducted with micron

  4. Application of calcium chloride as an additive for secondary refrigerant in the air conditioning system type chiller to minimized energy consumption

    NASA Astrophysics Data System (ADS)

    Suwono, A.; Indartono, Y. S.; Irsyad, M.; Al-Afkar, I. C.

    2015-09-01

    One way to resolve the energy problem is to increase the efficiency of energy use. Air conditioning system is one of the equipment that needs to be considered, because it is the biggest energy user in commercial building sector. Research currently developing is the use of phase change materials (PCM) as thermal energy storage (TES) in the air conditioning system to reduce energy consumption. Salt hydrates have been great potential to be developed because they have been high latent heat and thermal conductivity. This study has used a salt hydrate from calcium chloride to be tested in air conditioning systems type chiller. Thermal characteristics were examined using temperature history (T-history) test and differential scanning calorimetry (DSC). The test results showed that the thermal characteristics of the salt hydrate has been a high latent heat and in accordance with the evaporator temperature. The use of salt hydrates in air conditioning system type chiller can reduce energy consumption by 51.5%.

  5. Characteristics of biochar derived from marine macroalgae and fabrication of granular biochar by entrapment in calcium-alginate beads for phosphate removal from aqueous solution.

    PubMed

    Jung, Kyung-Won; Jeong, Tae-Un; Kang, Ho-Jeong; Ahn, Kyu-Hong

    2016-07-01

    In this work, granular biochar, Laminaria japonica-derived biochar (LB)-calcium alginate beads (LB-CAB), was successfully prepared by dropping a mixture of powder biochar and alginate solution into a calcium chloride solution for phosphate adsorption. Among different marine macroalgae derived biochars, LB exhibited the best performance, showing a phosphate removal rate of 97.02%, which was attributed to its high Ca/P and Mg/P ratios. With increasing pyrolysis temperature up to 600°C, the physicochemical properties of LB became suitable for adsorbing phosphate. Experimental results of kinetics and equilibrium isotherms at different temperatures (10-30°C) showed that the phosphate adsorption process is endothermic and is mainly controlled by external mass transfer and the intraparticle diffusion rate. The maximum adsorption capacity was found to be 157.7mgg(-1) at 30°C, as fitted by the Langmuir-Freundlich model, which is higher than capacities of other powder form of biochars.

  6. Structural, dynamic, and transport properties of concentrated aqueous sodium chloride solutions under an external static electric field.

    PubMed

    Ren, Gan; Shi, Rui; Wang, Yanting

    2014-04-24

    In the absence of an external electric field, it has already been known that ion clusters are formed instantaneously in moderately concentrated ionic solutions. In this work, we use molecular dynamics (MD) simulations to investigate the changes of structural, dynamic, and transport properties in a sodium chloride solution under an external electric field from the ion cluster perspective. Our MD simulation results indicate that, with a strong external electric field E (≥0.1 V/nm) applied, ion clusters become smaller and less net charged, and the structures and dynamics as well as transport properties of the ion solution become anisotropic. The influence of the cluster structure and shell structure to transport properties was analyzed and the Einstein relation was found invalid in this system.

  7. Development of a Combined Solution Formulation of Atropine Sulfate and Obidoxime Chloride for Autoinjector and Evaluation of Its Stability

    PubMed Central

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

    2013-01-01

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

  8. Calcium and ascorbic acid affect cellular structure and water mobility in apple tissue during osmotic dehydration in sucrose solutions.

    PubMed

    Mauro, Maria A; Dellarosa, Nicolò; Tylewicz, Urszula; Tappi, Silvia; Laghi, Luca; Rocculi, Pietro; Rosa, Marco Dalla

    2016-03-15

    The effects of the addition of calcium lactate and ascorbic acid to sucrose osmotic solutions on cell viability and microstructure of apple tissue were studied. In addition, water distribution and mobility modification of the different cellular compartments were observed. Fluorescence microscopy, light microscopy and time domain nuclear magnetic resonance (TD-NMR) were respectively used to evaluate cell viability and microstructural changes during osmotic dehydration. Tissues treated in a sucrose-calcium lactate-ascorbic acid solution did not show viability. Calcium lactate had some effects on cell walls and membranes. Sucrose solution visibly preserved the protoplast viability and slightly influenced the water distribution within the apple tissue, as highlighted by TD-NMR, which showed higher proton intensity in the vacuoles and lower intensity in cytoplasm-free spaces compared to other treatments. The presence of ascorbic acid enhanced calcium impregnation, which was associated with permeability changes of the cellular wall and membranes. PMID:26575708

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

    SciTech Connect

    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 approx. 20 and 400/sup 0/C. The hydrolysis of Mg/sup 2 +/ ions in simulated repository brines containing high magnesium concentrations causes acidification at temperatures above 25/sup 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.

  10. A statistical assessment of the quantitative uptake of vinyl chloride monomer from aqueous solution.

    PubMed

    Withey, J R; Collins, B T

    1976-11-01

    The presence of vinyl chloride monomer (VCM) in foodstuffs and its demonstrated carcinogenic potential when administered by the oral route has raised questions concerning the quantitative estimation of the safety of the use of food packaging fabricated from rigid polyvinyl chloride. A statistical model, which was tested by curve-fitting data obtained from an oral uptake study, has been demonstrated to be of predictive value. Ninety-five percent condifence limits were also calculated, and the data from this study were compared with those from a previous gas phase exposure study. It was concluded that if the total daily liquid intake contained 20 ppm of VCM then the area generated under the blood level-time curve, for rats, would be equivalent to an inhalation exposure of about 2 ppm for 24 hr.

  11. Molecular dynamics study on the growth of structure I methane hydrate in aqueous solution of sodium chloride.

    PubMed

    Tung, Yen-Tien; Chen, Li-Jen; Chen, Yan-Ping; Lin, Shiang-Tai

    2012-12-01

    The structure, thermodynamic, and kinetic properties of methane hydrates formed from the aqueous solution of sodium chloride are investigated based on molecular dynamics simulations. A three-phase molecular model consisting of a slab of methane hydrate phase, a slab of liquid water containing sodium chloride, and a gas phase of methane molecules is used. The decrease in the three-phase coexisting temperatures (by 2-3 K) at different pressures (10-100 MPa) for aqueous NaCl solutions (about 2 mol %) confirms the thermodynamic inhibition of NaCl. The growth rate of methane hydrates in NaCl solution is found to be half to one-third of that in pure water. The kinetic inhibition of NaCl is found to be a result of the reduced water repelling at the growing interface due to the strong hydration of ions. Individual ions or NaCl ion pairs can replace water molecules to participate in the formation of the cage structures. The distortion of water cages due to the presence of ions may result in a reduced fraction of occupation of methane in the cage cavities. Our results provide useful insights into the mechanism of growth of methane hydrates in seawater and the desalination.

  12. Effect of divalent ions on electroosmotic transport in a sodium chloride aqueous solution confined in an amorphous silica nanochannel

    NASA Astrophysics Data System (ADS)

    Conlisk, A. T.; Zambrano, Harvey; Cevheri, Necmettin; Yoda, Minami; Computational Micro-; Nanofluidics Lab Team; The Fluids, Optical; Interfacial Diagnostics Lab Team

    2012-11-01

    A critical enabling technology for the next generation of nanoscale devices, such as nanoscale ``lab on a chip'' systems, is controlling electroosmotic flow (EOF) in nanochannels. In this work, we control EOF in an aqueous sodium chloride (NaCl) solution confined in a silica nanochannel by systematically adding different amounts of divalent ions. Multivalent ions have a different affinity for the silica surface and different hydration characteristics in comparison to monovalent ions. Therefore by adding Mg++ and Ca++ to the sodium chloride solution, the electroosmotic velocity and the structure of the electrical double layer will be modified. The effects of adding Mg++ and Ca++ will be compared using non-equilibrium molecular dynamics simulations of the EOF at different electric fields of a NaCl solution in a silica nanochannel with different fractions of Ca++ and Mg++ ions. In general, the wall zeta-potential magnitude, and hence the EOF velocity, decreases as the Ca++ or Mg++ concentration increases. The system responds linearly with electric field. We will compare the computational results with the experimental data of Cevheri and Yoda (2012). This work is supported by Army Research Office (ARO) grant number W911NF1010290.

  13. Contribution of calcium-activated chloride channel to elevated pulmonary artery pressure in pulmonary arterial hypertension induced by high pulmonary blood flow

    PubMed Central

    Wang, Kai; Chen, Chuansi; Ma, Jianfa; Lao, Jinquan; Pang, Yusheng

    2015-01-01

    The correlation between calcium-activated chloride channel (CaCC) and pulmonary arterial hypertension (PAH) induced by high pulmonary blood flow remains uncertain. In this study, we investigated the possible role and effects of CaCC in this disease. Sixty rats were randomly assigned to normal, sham, and shunt groups. Rats in the shunt group underwent abdominal aorta and inferior vena cava shunt surgery. The pulmonary artery pressure was measured by catheterization. Pathological changes, right ventricle hypertrophy index (RVHI), arterial wall area/vessel area (W/V), and arterial wall thickness/vessel external diameter (T/D) were analyzed by optical microscopy. Electrophysiological characteristics of pulmonary arterial smooth muscle cells (PASMCs) were investigated using patch clamp technology. After 11 weeks of shunting, PAH and pulmonary vascular structural remodeling (PVSR) developed, accompanied by increased pulmonary pressure and pathological interstitial pulmonary changes. Compared with normal and sham groups, pulmonary artery pressure, RVHI, W/V, and T/D of the shunt group rats increased significantly. Electrophysiological results showed primary CaCC characteristics. Compared with normal and sham groups, membrane capacitance and current density of PASMCs in the shunt group increased significantly, which were subsequently attenuated following chloride channel blocker niflumic acid (NFA) treatment. To conclude, CaCC contributed to PAH induced by high pulmonary blood flow and may represent a potential target for treatment of PAH. PMID:25755701

  14. Contribution of calcium-activated chloride channel to elevated pulmonary artery pressure in pulmonary arterial hypertension induced by high pulmonary blood flow.

    PubMed

    Wang, Kai; Chen, Chuansi; Ma, Jianfa; Lao, Jinquan; Pang, Yusheng

    2015-01-01

    The correlation between calcium-activated chloride channel (CaCC) and pulmonary arterial hypertension (PAH) induced by high pulmonary blood flow remains uncertain. In this study, we investigated the possible role and effects of CaCC in this disease. Sixty rats were randomly assigned to normal, sham, and shunt groups. Rats in the shunt group underwent abdominal aorta and inferior vena cava shunt surgery. The pulmonary artery pressure was measured by catheterization. Pathological changes, right ventricle hypertrophy index (RVHI), arterial wall area/vessel area (W/V), and arterial wall thickness/vessel external diameter (T/D) were analyzed by optical microscopy. Electrophysiological characteristics of pulmonary arterial smooth muscle cells (PASMCs) were investigated using patch clamp technology. After 11 weeks of shunting, PAH and pulmonary vascular structural remodeling (PVSR) developed, accompanied by increased pulmonary pressure and pathological interstitial pulmonary changes. Compared with normal and sham groups, pulmonary artery pressure, RVHI, W/V, and T/D of the shunt group rats increased significantly. Electrophysiological results showed primary CaCC characteristics. Compared with normal and sham groups, membrane capacitance and current density of PASMCs in the shunt group increased significantly, which were subsequently attenuated following chloride channel blocker niflumic acid (NFA) treatment. To conclude, CaCC contributed to PAH induced by high pulmonary blood flow and may represent a potential target for treatment of PAH.

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

    NASA Astrophysics Data System (ADS)

    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.

  16. Comparison of Electrochemical Methods to Determine Crevice Corrosion Repassivation Potential of Alloy 22 in Chloride Solutions

    SciTech Connect

    K. Evans; A. Yilmaz; S. Day; L. Wong; J. Estill

    2004-08-23

    Alloy 22 (N06022) is a nickel-based alloy highly resistant to corrosion. In some aggressive conditions of high chloride concentration, temperature and applied potential, Alloy 22 may suffer crevice corrosion, a form of localized corrosion. There are several electrochemical methods that can be used to determine localized corrosion in metallic alloys. One of the most popular for rapid screening is the cyclic potentiodynamic polarization (CPP). This work compares the repassivation potentials obtained using CPP to related repassivation potential values obtained using the Tsujikawa-Hisamatsu Electrochemical (THE) method and the potentiostatic (POT) method. Studied variables included temperature and chloride concentration. The temperature was varied from 30 C and 120 C and the chloride concentration was varied between 0.0005 M to 4 M. Results show that similar repassivation potentials were obtained for Alloy 22 using CPP and THE methods. Generally, under more aggressive conditions, the repassivation potentials were more conservative using the CPP method. POT tests confirmed the validity of the repassivation potential as a threshold below which localized corrosion does not nucleate. The mode of attack in the tested specimens varied depending if the test method was CPP or THE; however, the repassivation potential remained the same.

  17. Effectiveness of hydrothermal-calcium chloride treatment and chitosan on quality retention and microbial growth during storage of fresh-cut papaya.

    PubMed

    Ayón-Reyna, Lidia E; Tamayo-Limón, Ransés; Cárdenas-Torres, Feliznando; López-López, Martha E; López-Angulo, Gabriela; López-Moreno, Héctor S; López-Cervántes, Jaime; López-Valenzuela, José A; Vega-García, Misael O

    2015-03-01

    Rapid degradation of fresh-cut papaya limits its marketability. Hydrothermal treatments in combination with a calcium dip, applied to whole fruit before slicing, and also the application of chitosan as a coating film, have been found to have very good results in maintaining the quality of fresh-cut fruits. Based on these considerations, the aim of this study was to evaluate the effect of hydrothermal treatment (HT; 49 °C, 25 min) containing calcium chloride (Ca; 1%, w/v) followed by dipping in chitosan (Chit; 1%, w/v, 3 min) on the physical, chemical, and microbial qualities of papaya slices stored at 5 °C for 10 d. Pulp color, firmness, ascorbic acid, total phenolics, β-carotene, and lycopene were evaluated every 2 d while the microbial quality (mesophilics, psychrophilics, molds, and yeasts) was evaluated every 5 d. Fruit treated with HT-Ca and HT-Ca + Chit showed better color and firmness retention than Control and Chit. Papaya slices treated with HT-Ca + Chit had higher nutritional content and lower microbial growth at the end of storage. The application of the HT-Ca + Chit could be used to reduce deterioration processes, maintaining physical, chemical, and microbial qualities and increasing the shelf life of fresh-cut papaya stored at 5 °C.

  18. Aluminum Chloride Induces Osteoblasts Apoptosis via Disrupting Calcium Homeostasis and Activating Ca(2+)/CaMKII Signal Pathway.

    PubMed

    Cao, Zheng; Liu, Dawei; Zhang, Qiuyue; Sun, Xudong; Li, Yanfei

    2016-02-01

    Aluminum promotes osteoblast (OB) apoptosis. Apoptosis is induced by the disordered calcium homeostasis. Therefore, to investigate the relationship between Al-induced OB apoptosis and calcium homeostasis, calvarium OBs from neonatal rats (3-4 days) were cultured and exposed to 0.048-mg/mL Al(3+) or 0.048-mg/mL Al(3+) combined with 5 μM BAPTA-AM (OBs were pretreated with 5 μM BAPTA-AM for 1 h, then added 0.048 mg/mL Al(3+)), respectively. Then OB apoptosis rate, intracellular calcium ions concentration ([Ca(2+)]i), mRNA expression level of calmodulin (CaM), and protein expression levels of CaM and p-CaMKII in OBs were examined. The result showed that AlCl3 increased OB apoptosis rate, and [Ca(2+)]i and p-CaMKII expression levels and decreased CaM expression levels, whereas BAPTA-AM relieved the effects. These results proved that AlCl3 induced OB apoptosis by disrupting the intracellular Ca(2+) homeostasis and activating the Ca(2+)/CaMKII signal pathway. Our findings can provide new insights for revealing the apoptosis mechanism of OBs exposed to AlCl3.

  19. Cardioprotective activity of alcoholic extract of Tinospora cordifolia (Willd.) Miers in calcium chloride-induced cardiac arrhythmia in rats

    PubMed Central

    Sharma, Ashish Kumar; Kishore, Kunal; Sharma, Divya; Srinivasan, B.P; Agarwal, Shyam Sunder; Sharma, Ashok; Singh, Santosh Kumar; Gaur, Samir; Jatav, Vijay Singh

    2011-01-01

    The present study investigated the antiarrhythmic activity of alcoholic extract of Tinospora cordifolia (T. cordifolia) in CaCl2 induced arrhythmia. CaCl2 (25 mg/kg) was administered by intravenous infusion (iv) to produce arrhythmia in rats. The animals were then treated with T. cordifolia extract (150, 250, and 450 mg/kg) and verapamil (5 mg/kg,iv). Lead II electrocardiogram was monitored. Plasma calcium, sodium and potassium levels were measured. In CaCl2 induced arrhythmia, heart rate was decreased by 41.10%, T. cordifolia at 150, 300, and 450 mg/kg decreased the heart rate by 26.30%, 29.16%, and 38.29%, respectively, and verapamil reduced the heart rate by 9.70% compared to the normal group. The PQRST waves were normalized and atrial and ventricular fibrillation was controlled in rats treated with verapamil and T. cordifolia. CaCl2 increased calcium and sodium levels and decreased potassium levels in blood. T. cordifolia dose-dependently decreased calcium and sodium levels and increased potassium levels. Hence, T. cordifolia can be used in antiarrhythmic clinical settings and beneficial in atrial and ventricular fibrillation and flutter and may be indicated in ventricular tachyarrhythmia. PMID:23554702

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

    NASA Astrophysics Data System (ADS)

    Zhou, BeiBei; Wang, QuanJiu

    2016-04-01

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

  1. Human body frequency modulation by 0.9% sodium chloride solutions: a new paradigm and perspective for human health.

    PubMed

    Sudan, B J

    2000-08-01

    This case study demonstrates that the normal human body frequency, which can be disturbed by electromagnetic influences of the environment, can be modulated by 0.9% sodium chloride solutions (physiological saline) and that occurrence of allergic reactions have subsequently been suppressed as a result of this modulation. The use of distilled water as control showed no effect on occurrence of allergic reactions. Further observations on the growth of various plants in a greenhouse exposed to various geomagnetic fields support the previous observations on humans. The neutralization of electromagnetic influences on humans using 0.9% sodium chloride solution or by enclosure of plants within a copper wire Faraday cage resulting in a normal and uniform growth of plants as compared with disturbed and irregular growth in unenclosed controls, is demonstrated. These original observations propose a new strategy to suppress or prevent allergic reactions and possibly other effects observed in various human pathologies in relation to a disturbance of human body frequencies. It is hypothesized that the double helix structure of desoxyribonucleic acid (DNA) could be modified by environmental electromagnetic fields and that disresonance between the two chains of DNA could lead to the expression of specific pathology. PMID:10904434

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

    PubMed

    Mamontov, E; Ohl, M

    2013-07-14

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

  3. The role of macrocyclic compounds in the extraction and possible separation of platinum and rhodium from chloride solutions

    NASA Astrophysics Data System (ADS)

    Jyothi, Rajesh Kumar; Lee, Jin-Young

    2016-06-01

    Macrocyclic compounds (crown ethers), specifically 18-crown-6 (18-C-6), benzo-15-crown-5 (B-15-C-5), di-benzo-18-crown-6 (DB-18-C-6) and di-cyclohexano-18-crown-6 (DC-18C-6), are used as extractants as well as synergists with amine-group extractants. Platinum and rhodium belong to platinum-group metals (PGMs) and have very similar ionic radii and similar properties. The separation of PGMs is most useful for the preparation of functional materials. Macrocyclic compounds are tested for platinum and rhodium separation and are found to achieve marginal separation. Amines (used as extractants) are paired with macrocyclic compounds (used as synergists), and the separation factor between platinum and rhodium is increased with synergistic enhancement from a chloride solution. The present study discusses extraction chemistry, separation factors and the synergy between platinum and rhodium from chloride solutions. To ensure accurate data, the aqueous samples in this study are analyzed using an inductively coupled plasma optical emission spectrometer (ICP-OES).

  4. The role of macrocyclic compounds in the extraction and possible separation of platinum and rhodium from chloride solutions

    PubMed Central

    Jyothi, Rajesh Kumar; Lee, Jin-Young

    2016-01-01

    Macrocyclic compounds (crown ethers), specifically 18-crown-6 (18-C-6), benzo-15-crown-5 (B-15-C-5), di-benzo-18-crown-6 (DB-18-C-6) and di-cyclohexano-18-crown-6 (DC-18C-6), are used as extractants as well as synergists with amine-group extractants. Platinum and rhodium belong to platinum-group metals (PGMs) and have very similar ionic radii and similar properties. The separation of PGMs is most useful for the preparation of functional materials. Macrocyclic compounds are tested for platinum and rhodium separation and are found to achieve marginal separation. Amines (used as extractants) are paired with macrocyclic compounds (used as synergists), and the separation factor between platinum and rhodium is increased with synergistic enhancement from a chloride solution. The present study discusses extraction chemistry, separation factors and the synergy between platinum and rhodium from chloride solutions. To ensure accurate data, the aqueous samples in this study are analyzed using an inductively coupled plasma optical emission spectrometer (ICP-OES). PMID:27283394

  5. Synthesis of TiO(2) (Anatase) by Sol-Gel Process Performed in Metal Chlorides Saturated Aqueous Solutions.

    PubMed

    de Farias, Robson Fernandes

    2001-07-15

    Titania powders were synthesized by a sol-gel process using titanium tetrabutoxide as a precursor. The syntheses were performed in water or in saturated aqueous solutions of KCl, CaCl(2), NiCl(2), CoCl(2), and MnCl(2). It is demonstrated, by X-ray diffraction patterns of the synthesized powders that the samples obtained in saturated aqueous solutions of metal chlorides are crystalline (anatase phase) with some minor amount of brookite phase, whereas the sample synthesized in water is amorphous in nature. Thus, it is shown that the anatase phase can be obtained independently on any previous or further treatment of the synthesized powder, such as hydrothermal or heat treatment, providing a new, simple, quick, and inexpensive route to synthesize anatase powders. Copyright 2001 Academic Press.

  6. Ion-exchange extraction of platinum(II,IV) from chloride solutions in the presence of iron(III)

    NASA Astrophysics Data System (ADS)

    Kononova, O. N.; Duba, E. V.; Karplyakova, N. S.; Krylov, A. S.

    2015-08-01

    The sorption concentration of platinum(II,IV) in the presence of iron(III) is studied on new samples of domestically produced ionites of the CYBBER brand. In comparing the sorption and kinetic properties of the new ionites to those of sorbents of the Purolite brand studied earlier, the higher effectiveness of the former is demonstrated via the extraction of platinum(II,IV) ions from strongly and weakly acidic chloride solutions. It is found that the sorbed platinum ions can be completely separated from iron(III) ions through separate elution using 0.01-0.001 M HCl (iron ions) and a thiourea solution (80 g/L) in 0.3 M H2SO4 (platinum ions).

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

    PubMed

    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.

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

    PubMed

    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. PMID:25176491

  9. Influence of Buffer Composition and Calcium Chloride on GdnHCl Denaturation of Bacillus licheniformis α-Amylase.

    PubMed

    Kandandapani, Salanee; Tan, Cheau Y; Shuib, Adawiyah S; Tayyab, Saad

    2016-01-01

    The influence of buffer composition on the conformational stability of native and calciumdepleted Bacillus licheniformis α-amylase (BLA) was investigated against guanidine hydrochloride (GdnHCl) denaturation using circular dichroism, fluorescence and UV-difference spectroscopy. Differential effect of buffer composition on GdnHCl denaturation of BLA was evident from the magnitude of these spectral signals, which followed the order: sodium phosphate > Tris-HCl > HEPES > MOPS. These effects became more pronounced with calcium-depleted BLA. Sephacryl S-200 gel chromatographic results showed significant BLA aggregation in the presence of 6 M GdnHCl.

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

    PubMed Central

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

    2014-01-01

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

  11. Slow strain rate fracture of high-strength steel at controlled electrochemical potentials in ammonium chloride, potassium chloride, and ammonium nitrate solutions

    SciTech Connect

    Nguyen, D.T.; Nichols, D.E.; Daniels, R.D.

    1992-08-15

    Slow strain rate testing has been undertaken to determine the effects of individual chemical species on the fracture process of high-strength 4340 steel. Test environments included potassium chloride, ammonium nitrate, and ammonium chloride at concentrations from 0.001 to 1.0 mole por liter at ambient temperature. Tests were performed at cathodic and anodic controlled potentials, as well as at the open-circuit potential, to delineate the stress corrosion cracking range.

  12. Novel technique for phosphorus recovery from aqueous solutions using amorphous calcium silicate hydrates (A-CSHs).

    PubMed

    Okano, Kenji; Uemoto, Masahide; Kagami, Jumpei; Miura, Keiichi; Aketo, Tsuyoshi; Toda, Masaya; Honda, Kohsuke; Ohtake, Hisao

    2013-05-01

    A novel technique for phosphorus (P) recovery from aqueous solutions was developed using amorphous calcium silicate hydrates (A-CSHs). A-CSHs, which have a high Ca/Si molar ratio of 2.0 or greater, could be synthesized using unlimitedly available, inexpensive materials such as siliceous shale and calcium hydroxide. A-CSHs showed high performance for P recovery from an anaerobic sludge digestion liquor (ASDL) and the synthetic model liquor (s-ASDL) containing 89 mg PO4-P/L. After 20 min mixing, 1.5 g/L A-CSHs could remove approximately 69 and 73% PO4-P from ASDL and s-ASDL, respectively. By contrast, autoclaved lightweight concrete particles, which contained crystalline calcium silicate hydrates as a principal component, removed only 10 and 6% PO4-P from ASDL and s-ASDL, respectively, under the same experimental conditions. When A-CSHs were washed with deionized water to remove free Ca(OH)2, P removability was significantly improved (up to 82%) despite the reduction in the amount of Ca(2+) released. Unlike in the case of Ca(OH)2, no significant carbonate inhibition was observed with P removal by A-CSHs. Moreover, P removed by A-CSHs showed better settleability, filterability, and dewaterability than P precipitated with conventional CaCl2 and Ca(OH)2. The present study demonstrated that A-CSHs have great potential as a novel, beneficial material for P recovery and recycling. PMID:23497975

  13. Solution structure and backbone dynamics of the defunct domain of calcium vector protein.

    PubMed

    Théret, I; Baladi, S; Cox, J A; Gallay, J; Sakamoto, H; Craescu, C T

    2001-11-20

    CaVP (calcium vector protein) is a Ca(2+) sensor of the EF-hand protein family which is highly abundant in the muscle of Amphioxus. Its three-dimensional structure is not known, but according to the sequence analysis, the protein is composed of two domains, each containing a pair of EF-hand motifs. We determined recently the solution structure of the C-terminal domain (Trp81-Ser161) and characterized the large conformational and dynamic changes induced by Ca(2+) binding. In contrast, the N-terminal domain (Ala1-Asp86) has lost the capacity to bind the metal ion due to critical mutations and insertions in the two calcium loops. In this paper, we report the solution structure of the N-terminal domain and its backbone dynamics based on NMR spectroscopy, nuclear relaxation, and molecular modeling. The well-resolved three-dimensional structure is typical of a pair of EF-hand motifs, joined together by a short antiparallel beta-sheet. The tertiary arrangement of the two EF-hands results in a closed-type conformation, with near-antiparallel alpha-helices, similar to other EF-hand pairs in the absence of calcium ions. To characterize the internal dynamics of the protein, we measured the (15)N nuclear relaxation rates and the heteronuclear NOE effect in (15)N-labeled N-CaVP at a magnetic field of 11.74 T and 298 K. The domain is mainly monomeric in solution and undergoes an isotropic Brownian rotational diffusion with a correlation time of 7.1 ns, in good agreement with the fluorescence anisotropy decay measurements. Data analysis using a model-free procedure showed that the amide backbone groups in the alpha-helices and beta-strands undergo highly restricted movements on a picosecond to nanosecond time scale. The amide groups in Ca(2+) binding loops and in the linker fragment also display rapid fluctuations with slightly increased amplitudes. PMID:11705378

  14. The effect of chloride ion concentration gradients on the initiation of localized corrosion of steel in reinforced concrete

    SciTech Connect

    Kane, M.J.; Brown, R.

    1994-12-31

    It has been established that for steel reinforced concrete roads treated with deicing salts or exposed to a marine environment, chloride ions are introduced at the surface of the concrete structure. Two models were discussed in which chloride ion concentration gradients would form in a steel reinforced concrete structure. Electrochemical testing to investigate the models was conducted on plain carbon steel specimens in a simulated concrete environment of saturated calcium hydroxide solution with varying concentrations of sodium chloride. The varying chloride ion concentrations promoted open circuit potential shifts. These potential shifts may lead to galvanic corrosion effects depending on the chloride ion concentration gradients in the structure.

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

    PubMed Central

    de Oliveira, Fabrício Singaretti

    2014-01-01

    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. PMID:24762210

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

    PubMed

    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.

  17. Viscosities of the ternary solution dimethyl sulfoxide/water/sodium chloride at subzero temperatures and their application in cryopreservation.

    PubMed

    Zhang, Shaozhi; Yu, Xiaoyi; Chen, Zhaojie; Chen, Guangming

    2013-04-01

    Vitrification is considered as the most promising method for long-term storage of tissues and organs. An effective way to reduce the accompanied cryoprotectant (CPA) toxicity, during CPA addition/removal, is to operate at low temperatures. The permeation process of CPA into/out of biomaterials is affected by the viscosity of CPA solution, especially at low temperatures. The objective of the present study is to measure the viscosity of the ternary solution, dimethyl sulfoxide (Me2SO)/water/sodium chloride (NaCl), at low temperatures and in a wide range of concentrations. A rotary viscometer coupled with a low temperature thermostat bath was used. The measurement was carried out at temperatures from -10 to -50°C. The highest mass fraction of Me2SO was 75% (w/w) and the lowest mass fraction of Me2SO was the value that kept the solution unfrozen at the measurement temperature. The concentration of NaCl was kept as a constant [0.85% (w/w), the normal salt content of extracellular fluids]. The Williams-Landel-Ferry (WLF) model was employed to fit the obtained viscosity data. As an example, the effect of solution viscosity on modeling the permeation of Me2SO into articular cartilage was qualitatively analyzed.

  18. Dissolution of vitrified wastes in a high-pH calcium-rich solution

    NASA Astrophysics Data System (ADS)

    Utton, C. A.; Hand, R. J.; Bingham, P. A.; Hyatt, N. C.; Swanton, S. W.; Williams, S. J.

    2013-04-01

    The current baseline for the conditioning of most UK intermediate-level radioactive waste (ILW) is immobilisation using cement. However, vitrification of some UK ILW is being considered as an alternative. One option for the disposal of the resulting vitrified ILW would be to place it in a geological disposal facility in a high-pH environment with cemented ILW and a cement-based backfill. Therefore, the potential effects of such a high pH (˜12.5), calcium-rich cement-based environment on the dissolution behaviour of simulant ILW glasses have been studied using the product consistency test (PCT). Three non-radioactive waste compositions were assessed: a laboratory simulant ILW vitrified in a borosilicate glass and two full-scale simulant vitrified products (a slag containing simulant plutonium-contaminated material and Magnox sludge; and a glass containing clinoptilolite). Powdered samples were leached in saturated Ca(OH)2 solutions for up to 42 days at temperatures between 30 and 90 °C. In general the rates of dissolution were lower than expected at such a high pH compared to studies in the literature under alkaline conditions. In contrast to the typical dissolution behaviour of high level waste (HLW) glasses, dissolution of the simulant borosilicate ILW glass was initially slow, followed by a period of faster boron and alkali metal release. The saturation/residual regime was not reached within experimental timescales. The rate of dissolution during the period of faster release increased with increasing temperature; the activation energy for this stage of dissolution was calculated to be 47 ± 2 kJ mol-1 based on boron release. The two full-scale simulant glasses, which contained negligible boric oxide, exhibited conventional static dissolution profiles, and entered the residual rate regime after 7-14 days at 50 °C. The greater durability of the full-scale simulants is thought to be due to the greater content of network-forming oxides in these glasses compared to

  19. Analysis of electrochemical noise for Type 410 stainless steel in chloride solutions

    SciTech Connect

    Kelly, R.G.; Inman, M.E.; Hudson, J.L.

    1996-12-31

    The electrochemical noise resulting from the corrosion of Type 410 stainless steel under open circuit conditions in solutions of widely different corrosivity has been examined. Parameters derived from electrochemical noise measurements and conventional electrochemical measurements were correlated with one another and with post-test examination on the specimens. Both the noise resistance and the polarization resistance increased with decreases in solution corrosivity. In all of the solutions studied, the noise resistance was found to be consistently higher than the polarization resistance. In solutions in which pitting occurred, the open circuit potential of the electrode versus a true reference electrode was more sensitive to the transition to stable pitting than was the pitting index.

  20. Reduction of mercury from mackerel fillet using combined solution of cysteine, EDTA, and sodium chloride.

    PubMed

    Hajeb, P; Jinap, S

    2012-06-13

    An acidic solution containing mercury chelating agents to eliminate mercury in raw fish (mackerel) fillet was developed. The solution contained hydrochloric acid, sodium hydroxide, cysteine, EDTA, and NaCl. The optimum conditions for mercury reduction were achieved using response surface methodology (RSM) at cysteine concentration of 1.25%, EDTA of 275 mg/L, NaCl of 0.5%, pH of 3.75, and exposure time of 18 min. The optimized conditions produced a solution which can remove up to 91% mercury from raw fish fillet. Cysteine and EDTA were identified as potential chelating agents with the greatest potential for use. The solution can be employed in fish industries to reduce mercury in highly contaminated fish.

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

    SciTech Connect

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

    2005-11-04

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

  2. Solution combustion synthesis of calcium phosphate particles for controlled release of bovine serum albumin.

    PubMed

    Zhao, Junfeng; Zhao, Junjie; Qian, Yu; Zhang, Xiali; Zhou, Feifei; Zhang, Hong; Lu, Hongbin; Chen, JianHua; Wang, XuHong; Yu, Wencong

    2015-05-01

    Four different phase compositions of calcium phosphate (CaP) particles were prepared via a solution combustion method. X-ray diffraction (XRD) and Rietveld analysis results revealed that the variations in the nominal Ca/P (molar) ratios were found to provide a favorable control in the different proportions of CaP materials. Bovine serum albumin (BSA) was used as a model protein to study the loading and release behavior. The release profile indicated that the BSA release rates depended on the phase compositions of the CaP particles, and showed an order of TCP-BSA>BCP-1-BSA>BCP-2-BSA>HA-BSA. The results suggested that the BSA protein release rate can be controlled by varying the phase compositions of CaP carriers. Moreover, the release process involved two stages: firstly surface diffusion via ion exchange and secondly intraparticle diffusion.

  3. Degradation of trichloroethylene in aqueous solution by calcium peroxide activated with ferrous ion.

    PubMed

    Zhang, Xiang; Gu, Xiaogang; Lu, Shuguang; Miao, Zhouwei; Xu, Minhui; Fu, Xiaori; Qiu, Zhaofu; Sui, Qian

    2015-03-01

    The application of calcium peroxide (CaO2) activated with ferrous ion to stimulate the degradation of trichloroethylene (TCE) was investigated. The experimental results showed that TCE could be completely degraded in 5 min at a CaO2/Fe(II)/TCE molar ratio of 4/8/1. Probe compound tests demonstrated the presence of reactive oxygen species HO· and O2(-·) in CaO2/Fe(II) system, while scavenging tests indicated that HO· was the dominant active species responsible for TCE removal, and O2(-·) could promote TCE degradation in CaO2/Fe(II) system. In addition, the influences of initial solution pH and solution matrix were evaluated. It suggested that the elevation of initial solution pH suppressed TCE degradation. Cl(-) had significant scavenging effect on TCE removal, whereas HCO3(-) of high concentration showed favorable function. The influences of NO3(-) and SO4(2-) could be negligible, while natural organic matter (NOM) had a negative effect on TCE removal at a relatively high concentration. The results demonstrated that the technique of CaO2 activated with ferrous ion is a highly promising technique in in situ chemical oxidation (ISCO) remediation in TCE contaminated sites.

  4. X-ray characterization of an organic inorganic solution grown crystal: case of 2-amino-5-nitropyridinium chloride

    NASA Astrophysics Data System (ADS)

    Horiuchi, N.; Lefaucheux, F.; Ibanez, A.; Lorut, F.; Baruchel, J.

    2004-02-01

    The crystallline quality of 2-amino-5-nitropyridinium chloride gorwn in solution was examined by X-ray topography. Strong white beam coming from synchrotron was irradiated to an as-grown crystal to avoid an absorption of X-ray. Topographs were taken in transmission geometry (Laue setup). The image obtained by the reflections 3¯ 0 3 , 601, 6 1 2¯ and 1 7 0 planes showed fine grey contrast in nearly the whole section. Inclusions and strained growth sector boundaries were clearly observed in these images. These defects disappeared far from the seed in the direction of c-axis. The whole section of the reflection 1 7 0 was full of fine lines along c-axis with white and black contrast. It was found that a dendritic growth leaded to the formation of whiskers slightly misoriented along c-axis.

  5. Blue-Green Color Tunable Solution Processable Organolead Chloride-Bromide Mixed Halide Perovskites for Optoelectronic Applications.

    PubMed

    Sadhanala, Aditya; Ahmad, Shahab; Zhao, Baodan; Giesbrecht, Nadja; Pearce, Phoebe M; Deschler, Felix; Hoye, Robert L Z; Gödel, Karl C; Bein, Thomas; Docampo, Pablo; Dutton, Siân E; De Volder, Michael F L; Friend, Richard H

    2015-09-01

    Solution-processed organo-lead halide perovskites are produced with sharp, color-pure electroluminescence that can be tuned from blue to green region of visible spectrum (425-570 nm). This was accomplished by controlling the halide composition of CH3NH3Pb(BrxCl1-x)3 [0 ≤ x ≤ 1] perovskites. The bandgap and lattice parameters change monotonically with composition. The films possess remarkably sharp band edges and a clean bandgap, with a single optically active phase. These chloride-bromide perovskites can potentially be used in optoelectronic devices like solar cells and light emitting diodes (LEDs). Here we demonstrate high color-purity, tunable LEDs with narrow emission full width at half maxima (FWHM) and low turn on voltages using thin-films of these perovskite materials, including a blue CH3NH3PbCl3 perovskite LED with a narrow emission FWHM of 5 nm.

  6. Blue-Green Color Tunable Solution Processable Organolead Chloride-Bromide Mixed Halide Perovskites for Optoelectronic Applications.

    PubMed

    Sadhanala, Aditya; Ahmad, Shahab; Zhao, Baodan; Giesbrecht, Nadja; Pearce, Phoebe M; Deschler, Felix; Hoye, Robert L Z; Gödel, Karl C; Bein, Thomas; Docampo, Pablo; Dutton, Siân E; De Volder, Michael F L; Friend, Richard H

    2015-09-01

    Solution-processed organo-lead halide perovskites are produced with sharp, color-pure electroluminescence that can be tuned from blue to green region of visible spectrum (425-570 nm). This was accomplished by controlling the halide composition of CH3NH3Pb(BrxCl1-x)3 [0 ≤ x ≤ 1] perovskites. The bandgap and lattice parameters change monotonically with composition. The films possess remarkably sharp band edges and a clean bandgap, with a single optically active phase. These chloride-bromide perovskites can potentially be used in optoelectronic devices like solar cells and light emitting diodes (LEDs). Here we demonstrate high color-purity, tunable LEDs with narrow emission full width at half maxima (FWHM) and low turn on voltages using thin-films of these perovskite materials, including a blue CH3NH3PbCl3 perovskite LED with a narrow emission FWHM of 5 nm. PMID:26236949

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

    PubMed

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

    2004-11-01

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

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

    PubMed Central

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

    2012-01-01

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

  9. Serum calcium and magnesium concentrations and the use of a calcium-magnesium-borogluconate solution in the treatment of Friesian mares with retained placenta.

    PubMed

    Sevinga, M; Barkema, H W; Hesselink, J W

    2002-01-15

    The purpose of the present study was to compare serum calcium and magnesium concentrations in mares with or without a retained placenta (RP) and to evaluate treatment of mares with RP with oxytocin versus oxytocin combined with Ca-Mg-borogluconate solution. Blood samples were obtained within 12 h of foaling from Friesian mares with and without an RP (n = 90 and 65, respectively). Serum Ca and Mg concentrations were analyzed by atomic absorption spectrophotometry. In total, we treated 112 cases of RP in 101 Friesian mares by infusion of either oxytocin dissolved in saline solution or oxytocin dissolved in Ca-Mg-borogluconate solution. We defined RP as the failure to expel all or a part of the fetal membranes up to 3 h after delivery of the foal. We defined a positive response to the treatment as the passage of the entire placenta within 2 h after the infusion. Mares with RP had significantly lower serum calcium levels within 12 h of foaling than mares without RP. Serum magnesium levels showed no difference. Sixty-four percent of the mares treated with oxytocin in Ca-Mg-borogluconate solution responded positively to the treatment, compared to 44% of the mares treated with oxytocin in saline solution (P < 0.05).

  10. Study on Corrosion Performance of Cu-Te-Se Alloys in a 3.5% Sodium Chloride Solution

    NASA Astrophysics Data System (ADS)

    Jiao, Lin; Li, Meng; Zeng, Tao; Zhu, Dachuan

    2015-11-01

    Samples of Cu-Te-Se alloys, previously aged or treated as a solid solution, were immersed in 3.5% (mass fraction) sodium chloride solution to investigate their corrosion resistance at room temperature by determining their corrosive weight loss. The morphologies of the precipitated phase and surface products following immersion were observed by scanning electron microscope. In addition, energy-dispersive spectroscopic analysis was used to determine the elemental constituents of precipitated phase and corroded surface of the alloy samples. The phase composition was measured by x-ray diffraction, and the electrochemical polarization behavior of the samples was determined using an electrochemical workstation. The experimental results revealed that the alloy samples appeared to corrode uniformly, which was accompanied by a small amount of localized corrosion. There was the possibility that localized corrosion could increase following aging treatment. The addition of a small amount of tellurium and selenium to the alloy appeared to retard oxygen adsorption on the copper in the alloy, which has ameliorated the alloy corrosion due to the similar physical and chemical properties of oxygen. In comparison to the solid solution state, the corrosion resistance of the alloy appeared to decline slightly following aging treatment.

  11. Viscometric study of chitosan solutions in acetic acid/sodium acetate and acetic acid/sodium chloride.

    PubMed

    Costa, Cristiane N; Teixeira, Viviane G; Delpech, Marcia C; Souza, Josefa Virginia S; Costa, Marcos A S

    2015-11-20

    A viscometric study was carried out at 25°C to assess the physical-chemical behavior in solution and the mean viscometric molar mass (M¯v) of chitosan solutions with different deacetylation degrees, in two solvent mixtures: medium 1-acetic acid 0.3mol/L and sodium acetate 0.2mol/L; and medium 2-acetic acid 0.1mol/L and sodium chloride 0.2mol/L. Different equations were employed, by graphical extrapolation, to calculate the intrinsic viscosities [η] and the viscometric constants, to reveal the solvent's quality: Huggins (H), Kraemer (K) and Schulz-Blaschke (SB). For single-point determination, the equations used were SB, Solomon-Ciuta (SC) and Deb-Chanterjee (DC), resulting in a faster form of analysis. The values of ̄M¯v were calculated by applying the equation of Mark-Houwink-Sakurada. The SB and SC equations were most suitable for single-point determination of [η] and ̄M¯v and the Schulz-Blachke constant (kSB), equal to 0.28, already utilized for various systems, can also be employed to analyze chitosan solutions under the conditions studied.

  12. Corrosion of commercially pure Al 99.5 in chloride solutions containing carbon dioxide, bicarbonate, and copper ions

    SciTech Connect

    Bjoergum, A.; Sigurdsson, H.; Nisancioglu, K.

    1995-07-01

    There has been a certain amount of interest recently in the use of aluminum alloys as an alternative material to steel for the processing and transmission of produced crude oil in the offshore oil industry. The corrosion behavior of aluminum in solutions containing chloride, carbon dioxide, bicarbonate, and copper ions at various concentrations and temperatures has been of frequent interest in connection with applications in direct contact with a corrosive aqueous phase, such as in natural waters and produced brines. Available information about the combined effects of these species on aluminum is conflicting. A more systematic study was undertaken using commercially pure aluminum (DIN Al 99.5 [AA 1050A]) as the test material. Corrosion tests performed in Cl{sup {minus}} solutions containing these species indicated that dissolved CO{sub 2}-HCO{sub 3}{sup {minus}} combinations giving a neutral solution pH resulted in low corrosion rates for aluminum. The added presence of small Cu{sup 2+} concentrations could have been detrimental but did not produce a synergistic effect. High temperatures in general caused increased corrosion rates, except near pH 9, where the cathodic intermetallic phases passivated. The observed corrosion behavior was explained in terms of cathodic polarization data for the aluminum matrix and the Al{sub 3}Fe intermetallic particles.

  13. Effect of calcium chloride on abating inhibition due to volatile fatty acids during the start-up period in anaerobic digestion of municipal solid waste.

    PubMed

    Kumar, Sunil; Das, Avijit; Srinivas, G Lohit Kumar; Dhar, Hiya; Ojha, Vivek Kumar; Wong, Jonathan

    2016-01-01

    Biomethanation of municipal solid waste (MSW) is a slow process and the yield of biogas is usually low. The present study was carried out to examine the effect of calcium chloride (CaCl2) on anaerobic digestion of MSW. Three anaerobic digesters with different concentrations of CaCl2, namely sample without additives (Control), sample with 2.5 g/L CaCl2 (R1) and sample with 5 g/L CaCl2 (R2) were studied separately and the significant results are presented. From the experimental results, it was observed that pH decreased with an increase in the dosage of CaCl2. Total solids and volatile solids reduction percentage in digester R2 was considerably lower than Control and R1 digesters. The significant positive correlation with small increments in volatile solids and chemical oxygen demand (COD) reduction were observed with an increase in pH. The cumulative biogas production in all the three digesters (Control, R1 and R2) were observed to be 35.38, 46.46 and 37.56 L, respectively. It was also observed that the volatile fatty acids (VFAs) removal efficiency in digester R1 was the best among all the three digesters. A comparison of the effluent characteristics revealed improvement in the overall performance of the digester R1 amended with 2.5 g/L CaCl2 over the other two digesters. PMID:26609893

  14. Combined effects of potassium lactate and calcium ascorbate as sodium chloride substitutes on the physicochemical and sensory characteristics of low-sodium frankfurter sausage.

    PubMed

    Choi, Y M; Jung, K C; Jo, H M; Nam, K W; Choe, J H; Rhee, M S; Kim, B C

    2014-01-01

    The purpose of this study was to evaluate the combined effects of sodium chloride (NaCl) substitutes, including potassium lactate (K-lactate) and calcium ascorbate (Ca-ascorbate), on the physicochemical and sensory characteristics of low-sodium frankfurter sausage (1.2% content of NaCl). Sausages produced with 40% substitution of NaCl with combined K-lactate and Ca-ascorbate showed a higher value of lightness (P<0.001) than sausages containing 2.0% content of NaCl (control). However, the sensory panels were unable to distinguish a difference in color intensity between the control and treatment groups. Frankfurter sausages produced with 30% K-lactate and 10% Ca-ascorbate exhibited similar water-holding capacity, textural properties, and organoleptic characteristics (P>0.05) when compared to control sausages. Thus, the use of these salt mixtures is a good way to reduce the NaCl content in meat products while maintaining the quality of meat products. These results may be useful in developing low-sodium meat products. PMID:23896133

  15. Inhibition of Calcium-Activated Chloride Channel ANO1/TMEM16A Suppresses Tumor Growth and Invasion in Human Lung Cancer.

    PubMed

    Jia, Linghan; Liu, Wen; Guan, Lizhao; Lu, Min; Wang, KeWei

    2015-01-01

    Lung cancer or pulmonary carcinoma is primarily derived from epithelial cells that are thin and line on the alveolar surfaces of the lung for gas exchange. ANO1/TMEM16A, initially identified from airway epithelial cells, is a member of Ca2+-activated Cl- channels (CaCCs) that function to regulate epithelial secretion and cell volume for maintenance of ion and tissue homeostasis. ANO1/TMEM16A has recently been shown to be highly expressed in several epithelium originated carcinomas. However, the role of ANO1 in lung cancer remains unknown. In this study, we show that inhibition of calcium-activated chloride channel ANO1/TMEM16A suppresses tumor growth and invasion in human lung cancer. ANO1 is upregulated in different human lung cancer cell lines. Knocking-down ANO1 by small hairpin RNAs inhibited proliferation, migration and invasion of GLC82 and NCI-H520 cancel cells evaluated by CCK-8, would-healing, transwell and 3D soft agar assays. ANO1 protein is overexpressed in 77.3% cases of human lung adenocarcinoma tissues detected by immunohistochemistry. Furthermore, the tumor growth in nude mice implanted with GLC82 cells was significantly suppressed by ANO1 silencing. Taken together, our findings provide evidence that ANO1 overexpression contributes to tumor growth and invasion of lung cancer; and suppressing ANO1 overexpression may have therapeutic potential in lung cancer therapy.

  16. Effect of calcium chloride on abating inhibition due to volatile fatty acids during the start-up period in anaerobic digestion of municipal solid waste.

    PubMed

    Kumar, Sunil; Das, Avijit; Srinivas, G Lohit Kumar; Dhar, Hiya; Ojha, Vivek Kumar; Wong, Jonathan

    2016-01-01

    Biomethanation of municipal solid waste (MSW) is a slow process and the yield of biogas is usually low. The present study was carried out to examine the effect of calcium chloride (CaCl2) on anaerobic digestion of MSW. Three anaerobic digesters with different concentrations of CaCl2, namely sample without additives (Control), sample with 2.5 g/L CaCl2 (R1) and sample with 5 g/L CaCl2 (R2) were studied separately and the significant results are presented. From the experimental results, it was observed that pH decreased with an increase in the dosage of CaCl2. Total solids and volatile solids reduction percentage in digester R2 was considerably lower than Control and R1 digesters. The significant positive correlation with small increments in volatile solids and chemical oxygen demand (COD) reduction were observed with an increase in pH. The cumulative biogas production in all the three digesters (Control, R1 and R2) were observed to be 35.38, 46.46 and 37.56 L, respectively. It was also observed that the volatile fatty acids (VFAs) removal efficiency in digester R1 was the best among all the three digesters. A comparison of the effluent characteristics revealed improvement in the overall performance of the digester R1 amended with 2.5 g/L CaCl2 over the other two digesters.

  17. Combined inhibitory effect against postharvest storage rots and their effects on postharvest quality parameters in cherry tomatoes by cassia oil and calcium chloride.

    PubMed

    Feng, Wu; Zheng, Xiaodong; Chen, Jiaping

    2013-11-01

    The inhibitory effect of cassia oil alone or in combination with calcium chloride (CaCl2) against Alternaria alternata in vitro and in vivo was assessed on cherry tomatoes. The results demonstrated that concentrations of CaCl2 ranging from 0.25 to 3% enhanced the inhibitory effects of 200 μl of cassia oil per liter on the growth of A. alternata in vitro. The combination of 0.25% CaCl2 and 500 μl of cassia oil per liter showed a significant inhibition effect on decay development in both wounded artificially infected and unwounded naturally infected fruit. Importantly, these treatments did not reduce the overall quality of tomatoes. Defense-related enzyme activities were also evaluated. The results indicated that cassia oil alone or in combination with CaCl2 significantly enhanced defense-related enzyme activities, such as peroxidase and polyphenol oxidase. Together, these data suggest that the combination of cassia oil and CaCl2 may be an efficient method to limit cherry tomato decay caused by fungi.

  18. The Porcine Chloride Channel Calcium-Activated Family Member pCLCA4a Mirrors Lung Expression of the Human hCLCA4

    PubMed Central

    Plog, Stephanie; Grötzsch, Tanja; Klymiuk, Nikolai; Kobalz, Ursula; Gruber, Achim D.

    2012-01-01

    Pig models of cystic fibrosis (CF) have recently been established that are expected to mimic the human disease closer than mouse models do. The human CLCA (originally named chloride channels, calcium-activated) member hCLCA4 is considered a potential modifier of disease severity in CF, but its murine ortholog, mCLCA6, is not expressed in the mouse lung. Here, we have characterized the genomic structure, protein processing, and tissue expression patterns of the porcine ortholog to hCLCA4, pCLCA4a. The genomic structure and cellular protein processing of pCLCA4a were found to closely mirror those of hCLCA4 and mCLCA6. Similar to human lung, pCLCA4a mRNA was strongly expressed in porcine lungs, and the pCLCA4a protein was immunohistochemically detected on the apical membranes of tracheal and bronchial epithelial cells. This stands in sharp contrast to mouse mCLCA6, which has been detected exclusively in intestinal epithelia but not the murine lung. The results may add to the understanding of species-specific differences in the CF phenotype and support the notion that the CF pig model may be more suitable than murine models to study the role of hCLCA4. PMID:22205680

  19. Effect of the concentrations of calcium chloride and synthetic peptides in primers on dentin bond strength of an experimental adhesive system.

    PubMed

    Shinkai, Koichi; Taira, Yoshihisa; Suzuki, Masaya; Kato, Chikage; Yamauchi, Junichi; Suzuki, Shiro; Katoh, Yoshiroh

    2010-11-01

    The purpose of this study was to evaluate the microtensile bond strength (MTBS) of an experimental adhesive system, which was prepared using different concentrations of calcium chloride (CaCl(2)) and synthetic peptides (pA/pB). Specimens were divided into six experimental groups and two control groups. In the experimental groups, self-etching primers used in the adhesive system comprised both Primer-I (Clearfil SE Bond Primer (SEP) containing 1, 5, or 10 wt% CaCl(2)) and Primer-II (SEP containing 0.1, 1, 5, or 10 wt% pA/pB). The negative control group used Primer-I containing 10 wt% CaCl(2 )and Primer-II containing 10 wt% pA/pB. The positive control group used Clearfil SE Bond only. Respective primers, bonding resin, and composite paste were applied and photopolymerized individually on flattened dentin surfaces of extracted human molars. All specimens were subjected to MTBS testing (n=20). Two-way ANOVA revealed significant differences in MTBS among CaCl(2 )concentrations in Primer-I and pA/pB concentrations in Primer-II (p<0.001), and there was a significant interaction between these two factors (p=0.011).

  20. Combined inhibitory effect against postharvest storage rots and their effects on postharvest quality parameters in cherry tomatoes by cassia oil and calcium chloride.

    PubMed

    Feng, Wu; Zheng, Xiaodong; Chen, Jiaping

    2013-11-01

    The inhibitory effect of cassia oil alone or in combination with calcium chloride (CaCl2) against Alternaria alternata in vitro and in vivo was assessed on cherry tomatoes. The results demonstrated that concentrations of CaCl2 ranging from 0.25 to 3% enhanced the inhibitory effects of 200 μl of cassia oil per liter on the growth of A. alternata in vitro. The combination of 0.25% CaCl2 and 500 μl of cassia oil per liter showed a significant inhibition effect on decay development in both wounded artificially infected and unwounded naturally infected fruit. Importantly, these treatments did not reduce the overall quality of tomatoes. Defense-related enzyme activities were also evaluated. The results indicated that cassia oil alone or in combination with CaCl2 significantly enhanced defense-related enzyme activities, such as peroxidase and polyphenol oxidase. Together, these data suggest that the combination of cassia oil and CaCl2 may be an efficient method to limit cherry tomato decay caused by fungi. PMID:24215690

  1. A simple classification method for residual antibiotics using E. coli cells transformed by the calcium chloride method and drug resistance plasmid DNA.

    PubMed

    Lin, S Y; Kondo, F

    2001-01-01

    Using three different plasmid DNA codings for kanamycin (KM), chloramphenicol (CP), and ampicillin- (AMP) and tetracycline- (TC) resistance, four different competent Escherichia coli strains were transformed by the calcium chloride method to produce KM-, CP- and AMP- and TC-resistant strains. Evaluation of minimum inhibitory concentrations (MIC) of 22 antibiotics, showed KM-resistant E. coli to be cross resistant only to fradiomycin (FRM); CP-resistant E. coli, especially HB101 and JM109 strains, exhibited cross-resistance only to thiamphenicol (TP). On the other hand, AMP- and TC-resistant E. coli showed cross resistance to several penicillins, tetracyclines and erythromycin. E. coli ATCC-27166, the strain most sensitive to all drugs in this experiment, was employed for disc diffusion experiments and from the pattern of appearance of the inhibition zone, eight major antibiotics were divided into three groups depending on their activity against containing each of the three plasmids. Only gentamicin (GM) activity was not affected by any of the drug resistant strains. Assay techniques utilizing three resistant strains may be the technique for screening foods for antibiotic residues in the future.

  2. Combined effects of potassium lactate and calcium ascorbate as sodium chloride substitutes on the physicochemical and sensory characteristics of low-sodium frankfurter sausage.

    PubMed

    Choi, Y M; Jung, K C; Jo, H M; Nam, K W; Choe, J H; Rhee, M S; Kim, B C

    2014-01-01

    The purpose of this study was to evaluate the combined effects of sodium chloride (NaCl) substitutes, including potassium lactate (K-lactate) and calcium ascorbate (Ca-ascorbate), on the physicochemical and sensory characteristics of low-sodium frankfurter sausage (1.2% content of NaCl). Sausages produced with 40% substitution of NaCl with combined K-lactate and Ca-ascorbate showed a higher value of lightness (P<0.001) than sausages containing 2.0% content of NaCl (control). However, the sensory panels were unable to distinguish a difference in color intensity between the control and treatment groups. Frankfurter sausages produced with 30% K-lactate and 10% Ca-ascorbate exhibited similar water-holding capacity, textural properties, and organoleptic characteristics (P>0.05) when compared to control sausages. Thus, the use of these salt mixtures is a good way to reduce the NaCl content in meat products while maintaining the quality of meat products. These results may be useful in developing low-sodium meat products.

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

    NASA Astrophysics Data System (ADS)

    Narumi, Akira; Kashiwagi, Takao; Nakane, Ichirou

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

  4. Alloy 22 Localized Corrosion Susceptibility In Aqueous Solutions Of Chloride And Nitrate Salts Of Sodium And Potassium At 110 - 150?C

    SciTech Connect

    Felker, S; Hailey, P D; Lian, T; Staggs, K J; Gdowski, G E

    2006-01-17

    Alloy 22 (a nickel-chromium-molybdenum-tungsten alloy) is being investigated for use as the outer barrier of waste containers for a high-level nuclear waste repository in the thick unsaturated zone at Yucca Mountain, Nevada. Experiments were conducted to assess crevice corrosion of Alloy 22 in de-aerated aqueous solutions of chloride and nitrate salts of potassium and sodium in the temperature range 110-150 C (some limited testing was also conducted at 90 C). Electrochemical tests were run in neutral salt solutions without acid addition and others were run in salt solutions with an initial hydrogen ion concentration of 10{sup -4} molal. The Alloy 22 specimens were weld prism specimens and de-aeration was performed with nitrogen gas. No evidence of crevice corrosion was observed in the range 125-150 C. In the 120 to 160 C temperature range, the anionic concentration of stable aqueous solutions is dominated by nitrate relative to chloride. At nominally 120 C, the minimum nitrate to chloride ratio is about 4.5, and it increases to about 22 at nominally 155 C. The absence of localized corrosion susceptibility in these solutions is attributed to the known inhibiting effect of the nitrate anion. At 110 C, aqueous solutions can have dissolved chloride in excess of nitrate. Localized corrosion was observed at nitrate to chloride ratios up to 1.0, the highest ratio tested. The extent of localized corrosion was confined to the crevice region of the samples, and was limited for nitrate to chloride ratios greater than or equal to 0.3. Aqueous solution chemistry studies indicate that nitrate to chloride ratios of less than 0.5 are possible for temperatures up to nominally 116 C. However, the exact upper temperature limit is unknown and no electrochemical testing was done at these temperatures. Limited comparison between 8 m Cl aqueous solutions of Na + K on the one hand and Ca on the other indicated similar electrochemical E{sub crit} values and similar morphology of attack

  5. Long-term cement-corrosion in chloride-rich solutions - a thermodynamic interpretation

    NASA Astrophysics Data System (ADS)

    Bube, C.; Metz, V.; Schild, D.; Bohnert, E.; Kienzler, B.

    2012-04-01

    Nuclear waste disposal relies on safe enclosure of radionuclides over long time-scales. Most experiments on interactions of radionuclides with barrier materials are running for several months, in some cases up to a few years. Very few experiments are available that confirm the results on longer time-scales and reassure that equilibrium conditions will be approached on the long term. This communication presents the latest results of full-scale cement corrosion experiments doped with uranium, which have been conducted for up to 22 years. Cemented waste simulates of 200L size were doped with Unat and exposed to MgCl2-rich or NaCl-saturated brine in the Asse salt mine (T = 28 ± 1 ° C). Solution composition and pH were monitored regularly. Some of the experiments were terminated in order to sample and analyze the solid phases. A geochemical code with a Pitzer database for high ionic strength systems is used to calculate the aqueous and solid phases expected at equilibrium conditions. In order to evaluate the thermodynamic database for the cementitious system, calculated solid phases and solution compositions were additionally compared to results of laboratory experiments on cement corrosion in MgCl2-rich solutions with mass to volume ratios (m/V) between 0.025 and 1.0. Solid and solution composition of the laboratory experiments after ~3 years agree well with results predicted from the thermodynamic calculations. With increasing m/V, transformation of the initial MgCl2-rich solutions into CaCl2-rich solutions is observed. This exchange reaction of Mg from the solution against Ca in the cement leads to a pHm (-log[H+]) increase up to 12 (from initial values around 9). Major solid phases found by analytical methods are also obtained in the calculations (e.g. gypsum, calcite, hydrotalcite / friedel's salt, brucite). Discrepancies are caused by various amorphous phases, which cannot be represented in the database. In the full-scale experiments (with m/V around 2.7), a

  6. Biochemical and biophysical response to calcium chloride stress in Aspergillus niger and its role in malachite green degradation.

    PubMed

    Gomaa, Ola M; Selim, Nabila S; Linz, John E

    2013-04-01

    Filamentous fungi show great promise in remediation of environmental contaminants such as industrial dyes. In the current study, Aspergillus niger (Genbank ID: JF437542) decolorized 82 % of the test dye malachite green (MG; 50 mg/l) during cultivation for 24 h. The organism decolorized only 6 % of the MG at higher concentration (250 mg MG/l) during the same time period and growth was inhibited at this higher MG concentration. Exposing A. niger to different types of stress resulted in variable impacts on ability to decolorize MG. CaCl2 had the largest positive impact on decolorization. A. niger cultures treated with CaCl2 (1 M) decolorized 46 % of the MG (250 mg/l) in 1 h compared to 6 % in untreated control cultures. CaCl2 also increased catalase production in A. niger which strongly supported a direct relationship between stress response and decolorizing ability. Spectrophotometric measurement confirmed MG decolorization while Fourier transform infrared spectroscopy suggested that biodegradation of MG occurred. Cultures treated with CaCl2 accumulated fewer toxic MG by-products than untreated cultures. CaCl2-induced stress increased the permeability and conductivity of the fungal cell membrane. An observed increase in medium [H(+)] also suggested a change in Ca(2+)/H(+) exchange capacity in the fungal cell. Calcium ions had a pronounced effect on membrane properties and this may have had an important impact on signal transduction. We conclude that A. niger decolorizes MG and that CaCl2 enhances this process; the CaCl2 effect appears to be associated with stress response.

  7. Structures and spectroscopic characterization of calcium chloride-nicotinamide, -isonicotinamide, -picolinamide and praseodymium bromide-nicotinamide complexes

    NASA Astrophysics Data System (ADS)

    Xue, Junhui; Jiang, Ye; Li, Weihong; Yang, Limin; Xu, Yizhuang; Zhao, Guozhong; Zhang, Gaohui; Bu, Xiaoxia; Liu, Kexin; Chen, Jia'er; Wu, Jinguang

    2015-02-01

    The coordination structures formed by calcium complexes with nicotinamide (na), isonicotinamide (ina) and picolinamide (pa) and praseodymium bromide-na are reported. The structures of CaCl2·(C6H6N2O)2·2H2O (Ca-na), CaCl2·(C6H6N2O)2·4H2O (Ca-ina), CaCl2·(C6H6N2O)2·5H2O (Ca-pa) and PrBr3·(C6H6N2O)2·6H2O (PrBr-na) in the solid state have been characterized by X-ray single crystal diffraction, FTIR, FIR, THz and Raman spectroscopies. Carbonyl oxygen of nicotinamide is coordinated to Ca2+, but it is O-monodentate (carbonyl oxygen) and N,O-bidentate ligand (pyridyl nitrogen and carbonyl oxygen) for Pr3+ to form a chain structure in PrBr-na. For isonicotinamide, only carbonyl oxygen atom is coordinated to Ca2+. Pyridyl nitrogen and carbonyl oxygen of picolinamide are coordinated to Ca2+ to form a five-membered ring structure. The crystal structure and spectroscopic results indicate the differences of the coordination of Ca and Pr ions, the changes of hydrogen bonds and conformation of the ligands induced by complexation. Unlike transition metal ions, Sr2+ or lanthanide ions, Ca2+ is inclined to coordinate to carbonyl oxygen atoms of the ligands.

  8. Structures and spectroscopic characterization of calcium chloride-nicotinamide, -isonicotinamide, -picolinamide and praseodymium bromide-nicotinamide complexes.

    PubMed

    Xue, Junhui; Jiang, Ye; Li, Weihong; Yang, Limin; Xu, Yizhuang; Zhao, Guozhong; Zhang, Gaohui; Bu, Xiaoxia; Liu, Kexin; Chen, Jia'er; Wu, Jinguang

    2015-02-25

    The coordination structures formed by calcium complexes with nicotinamide (na), isonicotinamide (ina) and picolinamide (pa) and praseodymium bromide-na are reported. The structures of CaCl2·(C6H6N2O)2·2H2O (Ca-na), CaCl2·(C6H6N2O)2·4H2O (Ca-ina), CaCl2·(C6H6N2O)2·5H2O (Ca-pa) and PrBr3·(C6H6N2O)2·6H2O (PrBr-na) in the solid state have been characterized by X-ray single crystal diffraction, FTIR, FIR, THz and Raman spectroscopies. Carbonyl oxygen of nicotinamide is coordinated to Ca(2+), but it is O-monodentate (carbonyl oxygen) and N,O-bidentate ligand (pyridyl nitrogen and carbonyl oxygen) for Pr(3+) to form a chain structure in PrBr-na. For isonicotinamide, only carbonyl oxygen atom is coordinated to Ca(2+). Pyridyl nitrogen and carbonyl oxygen of picolinamide are coordinated to Ca(2+) to form a five-membered ring structure. The crystal structure and spectroscopic results indicate the differences of the coordination of Ca and Pr ions, the changes of hydrogen bonds and conformation of the ligands induced by complexation. Unlike transition metal ions, Sr(2+) or lanthanide ions, Ca(2+) is inclined to coordinate to carbonyl oxygen atoms of the ligands.

  9. Structures and spectroscopic characterization of calcium chloride-nicotinamide, -isonicotinamide, -picolinamide and praseodymium bromide-nicotinamide complexes.

    PubMed

    Xue, Junhui; Jiang, Ye; Li, Weihong; Yang, Limin; Xu, Yizhuang; Zhao, Guozhong; Zhang, Gaohui; Bu, Xiaoxia; Liu, Kexin; Chen, Jia'er; Wu, Jinguang

    2015-02-25

    The coordination structures formed by calcium complexes with nicotinamide (na), isonicotinamide (ina) and picolinamide (pa) and praseodymium bromide-na are reported. The structures of CaCl2·(C6H6N2O)2·2H2O (Ca-na), CaCl2·(C6H6N2O)2·4H2O (Ca-ina), CaCl2·(C6H6N2O)2·5H2O (Ca-pa) and PrBr3·(C6H6N2O)2·6H2O (PrBr-na) in the solid state have been characterized by X-ray single crystal diffraction, FTIR, FIR, THz and Raman spectroscopies. Carbonyl oxygen of nicotinamide is coordinated to Ca(2+), but it is O-monodentate (carbonyl oxygen) and N,O-bidentate ligand (pyridyl nitrogen and carbonyl oxygen) for Pr(3+) to form a chain structure in PrBr-na. For isonicotinamide, only carbonyl oxygen atom is coordinated to Ca(2+). Pyridyl nitrogen and carbonyl oxygen of picolinamide are coordinated to Ca(2+) to form a five-membered ring structure. The crystal structure and spectroscopic results indicate the differences of the coordination of Ca and Pr ions, the changes of hydrogen bonds and conformation of the ligands induced by complexation. Unlike transition metal ions, Sr(2+) or lanthanide ions, Ca(2+) is inclined to coordinate to carbonyl oxygen atoms of the ligands. PMID:25280333

  10. Polymorph selection and nanocrystallite rearrangement of calcium carbonate in carboxymethyl chitosan aqueous solution: Thermodynamic and kinetic analysis

    SciTech Connect

    Zhao, Donghui; Zhu, Yingchun; Li, Fang; Ruan, Qichao; Zhang, Shengmao; Zhang, Linlin; Xu, Fangfang

    2010-01-15

    In this article, the polymorph selection of calcium carbonate has been successfully achieved in water-soluble carboxymethyl chitosan aqueous solution at different temperatures (25-95 {sup o}C). Vaterite is formed in carboxymethyl chitosan solution 25 {sup o}C accompanied with trace of calcite, whereas pure aragonite is obtained at 95 {sup o}C. Scanning electron microscopy and transmission electron microscopy analyses show that the products are formed from the recrystallization of nanometer crystallites. Thermodynamic and kinetic analyses reveal that the polymorph of calcium carbonate is controlled and selected by kinetics in various temperatures. As a heterogeneous nucleator and stabilizing agent, carboxymethyl chitosan changes the nucleation and growth of calcium carbonate from thermodynamic into kinetic control. Under kinetic limitation, the reaction rate of aragonite increases along with the elevating of temperature and surpasses the rate of vaterite above 327 K.

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

    SciTech Connect

    Xu, Tianfu; Pruess, Karsten

    2001-10-01

    Understanding movement of saline sodium nitrate (NaNO{sub 3}) waste solutions is important for assessing the contaminant migration near leaking waste storage tanks in the unsaturated zone at the Hanford site (Washington, USA). The purpose of this study is to contribute a basic understanding of effects of the thermophysical behavior of NaNO{sub 3} solutions on fluid flow in unsaturated media. We first present mathematical expressions for the dependence of density, viscosity, solubility and vapor pressure of NaNO{sub 3} solutions on both salt concentration and temperature, which were determined by fitting from published measured data. Because the previous studies of thermophysical behavior of sodium chloride (NaCl) solutions can provide a basis for those of NaNO{sub 3} solutions, we also present a comparison of thermophysical properties of both salt solutions. We have implemented the functional thermophysical properties of NaNO{sub 3} solutions into a new TOUGH2 equation-of-state module EWASG-NaNO{sub 3}, which is modified from a previous TOUGH2 equation-of-state module EWASG for NaCl. Using the simulation tool, we have investigated effects of the thermophysical properties on fluid flow in unsaturated media. The effect of density and viscosity of saline solutions has been long recognized. Here we focus our attention on the effect of vapor pressure lowering due to salinity. We present simulations of a one-dimensional problem to study this salinity-driven fluid flow. A number of simulations were performed using different values of thermal conductivity, permeability, and temperature, to illustrate conditions and parameters controlling these processes. Results indicate that heat conduction plays a very important role in this salinity-driven vapor diffusion by maintaining a nearly constant temperature. The smaller the permeability, the more water is transferred into the saline environment. Effects of permeability on water flow are also complicated by effects of capillary

  12. [Adsorption Characteristics of Nitrate and Phosphate from Aqueous Solution on Zirconium-Hexadecyltrimethylammonium Chloride Modified Activated Carbon].

    PubMed

    Zheng, Wen-jing; Lin, Jian-wei; Zhan, Yan-hui; Wang, Hong

    2015-06-01

    A novel adsorbent material, i.e., zirconium-cationic surfactant modified activated carbon (ZrSMAC) was prepared by loading zirconium hydroxide and hexadecyltrimethylammonium chloride (CTAC) on activated carbon, and was used as an adsorbent for nitrate and phosphate removal from aqueous solution. The adsorption characteristics of nitrate and phosphate on ZrSMAC from aqueous solution were investigated in batch mode. Results showed that the ZrSMAC was effective for nitrate and phosphate removal from aqueous solution. The pseudo-second-order kinetic model fitted both the nitrate and phosphate kinetic experimental data well. The equilibrium isotherm data of nitrate adsorption onto the ZrSMAC were well fitted to the Langmuir, Dubinin-Radushkevich (D-R) and Freundlich isotherm models. The equilibrium isotherm data of phosphate adsorption onto the ZrSMAC could be described by the Langmuir and,D- R isotherm models. According to the Langmuir isotherm model, the maximum nitrate and phosphate adsorption capacities for the ZrSMAC were 7.58 mg x g(-1) and 10.9 mg x g(-1), respectively. High pH value was unfavorable for nitrate and phosphate adsorption onto the ZrSMAC. The presence of Cl-, HCO3- and SO4(2-) in solution reduced the nitrate and phosphate adsorption capacities for the ZrSMAC. The nitrate adsorption capacity for the ZrSMAC was reduced by the presence of coexisting phosphate in solution, and the phosphate adsorption capacity for the ZrSMAC was also reduced by the presence of coexisting nitrate in solution. About 90% of nitrate adsorbed on the ZrSMAC could be desorbed in 1 mol x L(-1) NaCl solution, and about 78% of phosphate adsorbed on the ZrSMAC could be desorbed in 1 mol x L(-1) NaOH solution. The adsorption mechanism of nitrate on the ZrSMAC included the anion exchange interactions and electrostatic attraction, and the adsorption mechanism of phosphate on the ZrSMAC included the ligand exchange interaction, electrostatic attraction and anion exchange interaction.

  13. Deep formation waters of Western Europe, Russia and North America characterised by sodium, calcium, magnesium and chloride concentrations

    NASA Astrophysics Data System (ADS)

    Bozau, Elke; Hemme, Christina; Sattler, Carl-Diedrich; van Berk, Wolfgang

    2015-04-01

    Deep formation water can be classified according to depth, temperature, and salinity (e.g., Graf et al. 1966, Kharaka & Hanor 2007). Most of the deep formation waters contain dissolved solids in excess of sea water. The hydrogeochemical development of formation water has been discussed for a long time. It is widely accepted that deep aquifers are influenced by the meteoric cycle and geochemical processes within the crust (e.g., Hebig et al. 2012). Similar hydrogeochemical signatures are found in deep formation waters of all continents and can be explained by general geochemical processes within the deep reservoirs (e.g., Land 1995). Therefore, data of deep formation waters from Western Europe, Russia, and North America are collected and classified by the major water components. The data are used to identify important hydrogeochemical processes (e.g., halite dissolution and albitisation) leading to different compositions of formation water. Two significant water types are identified: Na-Cl water and Na-Ca-Cl water. Based on the collected hydrogeochemical data, development trends are stated for the formation waters, and albitisation is favoured as the main process for calcium enrichment. Furthermore, differences of formation water according to stratigraphical units are shown for deep reservoirs of the North German Basin and the North Sea. References: Graf, D.L., 1982. Chemical osmosis, reverse chemical osmosis, and the origin of subsurface brines. Geochimica Cosmochimica Acta 46, 1431-1448. Hebig, K.H., Ito, N., Scheytt, T., Marui, A., 2012. Review: Deep groundwater research with focus on Germany. Hydrogeology Journal 20, 227-243. Kharaka, Y.K., Hanor, J.S., 2007. Deep fluids in continents: I. Sedimentary Basins. Treatise on Geochemistry 5, 1-48. Land, L.S., 1995. The role of saline formation water in the crustal cycling. Aquatic Geochemistry 1, 137-145. Acknowledgements: The presented data are results of the collaborative research program "gebo" (Geothermal energy

  14. Regeneration of zinc chloride hydrocracking catalyst

    DOEpatents

    Zielke, Clyde W.

    1979-01-01

    Improved rate of recovery of zinc values from the solids which are carried over by the effluent vapors from the oxidative vapor phase regeneration of spent zinc chloride catalyst is achieved by treatment of the solids with both hydrogen chloride and calcium chloride to selectively and rapidly recover the zinc values as zinc chloride.

  15. FT-Raman spectroscopic analysis of the most probable structures in aluminum chloride and tetrahydrofuran solutions

    NASA Astrophysics Data System (ADS)

    Alves, Carolina C.; Campos, Thiago B. C.; Alves, Wagner A.

    2012-11-01

    A study by concentration-dependent Raman spectroscopy is presented for solutions of AlCl3 in THF. The formation of small amounts of AlCl4- has been evidenced by the appearance of only one band at 348 cm-1 in the most diluted salt solution. Another band at 330 cm-1 starts rising with increasing salt concentration and it seems to belong to the [AlCl3(THF)3] complex. Indeed, this octahedral entity was confirmed by the quantitative analysis performed at the band envelope at 915 cm-1. At this region, additional bands at 927 and 858 cm-1 were observed and assigned to the C-C and C-O stretching modes, respectively, of THF molecules coordinated to the aluminum salt. Besides them, another band at 1042 cm-1 clearly reveals the existence of this population of molecules. Although neutral octahedral complexes seem to be the major species in more concentrated salt solutions, the Raman spectra show the presence of complex ions in whole studied concentration range.

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

    NASA Astrophysics Data System (ADS)

    Ren, Gan; Wang, Yan-Ting

    2015-12-01

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

  17. Comparisons of fixation of heat, radiation, and heat plus radiation damage by anisotonic sodium chloride solutions

    SciTech Connect

    Raaphorst, G.P.; Azzam, E.I.

    1982-06-01

    Heat treatment at temperatures greater than 40 degrees C synergistically enhanced damage produced by ionizing radiation. Researchers experiments indicated that radiation damage in exponentially growing Chinese hamster cells could be fixed in a dose-dependent manner by postirradiation treatment with both hypertonic and hypotonic NaCl solutions. At a 1,000-rad dose level, survival could be depressed by a factor of about 260. For various treatments at either 42 or 45 degrees C, exposure after heating to anisotonic solutions did not result in the fixation of heat damage. When cells were heated at 45 degrees C for 5 minutes and irradiated with 500 rad before or after heating or given 500 rad without heating and then exposed to 0.05 M NaCl solutions for 120 minutes, survival was reduced by factors of 875, 667, and 12, respectively. For heat treatments at lower temperatures, such as 41.5 or 42 degrees C, less damage fixation for the combined treatments was observed. The data indicated that heat and radiation damage were different and damage from the combined treatments was not the same for low- and high-treatment temperatures.

  18. Radiation effect on poly(vinylbenzyltrimethylammonium chloride) in aqueous solution: pulse radiolysis and steady-state study.

    PubMed

    Kumar, Virendra; Bhardwaj, Yatendra K; Sabharwal, Sunil; Mohan, Hari

    2004-06-01

    Poly(vinylbenzyltrimethylammonium chloride) (PVBT) has been synthesized by radiation-induced polymerization of Vinylbenzyltrimethylammonium chloride (VBT). The viscosity average molecular weight of synthesized polymer was estimated to be approximately 10(5) by viscosity measurements. The radiation-induced affects on PVBT have been investigated by steady-state and pulse radiolysis (PR) techniques. The reactions of primary radicals (*)OH, e(aq)(-), and H(*) generated by the radiolysis of water with PVBT were studied. The reactions of some other species such as N(3)(*), Cl(2)(*-), Br(2)(*-), SO(4)(*-), and CO(2)(*-) with PVBT were also investigated. The results indicate that the reactivity of these species toward PVBT is lower then that with the monomer VBT. The rate constants for the reactions of OH radical and H atom with PVBT were evaluated both by competition kinetics and by direct observation of the buildup of transient species. The difference in the rate constant values evaluated by the two methods indicated that (*)OH and H(*) react with PVBT to give more than one species. It was observed that the OH radical and H atom react with PVBT in different manners. Near neutral pH, the OH radicals react to form an adduct and to generate a radical by abstracting methylenic H atom. The H atom, however, also abstracts the H atom from the PVBT backbone. The rate constant value for the reaction of hydrated electron with PVBT was found to be 3.1 currency 10(9) dm(3) mol(-1) s(-1). Steady-state irradiation studies of the aqueous PVBT solution indicated that PVBT predominantly undergoes cross-linking on irradiation. Cross-linking is a function of dose rate, concentration, and ambient of irradiation. At concentrations < 2%, only intramolecular cross-linking takes place, whereas beyond this concentration, the intermolecular cross-linking of polymer chains takes place to form a soft gel. The gel dose (D(gel)) is a function of the ambient of irradiation.

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

    NASA Astrophysics Data System (ADS)

    Solehudin, Agus; Nurdin, Isdiriayani

    2014-03-01

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

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

    SciTech Connect

    Solehudin, Agus; Nurdin, Isdiriayani

    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.

  1. Modulating the structure and properties of poly(sodium 4-styrenesulfonate)/poly(diallyldimethylammonium chloride) multilayers with concentrated salt solutions.

    PubMed

    Han, Lulu; Mao, Zhengwei; Wuliyasu, He; Wu, Jindan; Gong, Xiao; Yang, Yuguang; Gao, Changyou

    2012-01-10

    Poly(sodium 4-styrenesulfonate) (PSS)/poly(diallyldimethylammonium chloride) (PDADMAC) multilayers were treated with 1-5 M NaCl solutions, resulting in continuous changes in the physicochemical properties of the multilayers. Significant mass loss was observed when the salt concentration was higher than 2 M and reached as high as 72% in a 5 M NaCl solution. The disassembly occurred initially in the superficial layers and then developed in the bulk multilayers. For the multilayers with PDADMAC as the outmost layer, the molar ratio of PSS/PDADMAC was increased and the surface chemistry was changed from PDADMAC domination below 2 M NaCl to PSS domination above 3 M NaCl. Owing to the higher concentrations of uncompensated for polyelectrolytes at both lower and higher salt concentrations, the swelling ratio of the multilayers was decreased until reaching 3 M NaCl and then was increased significantly again. The salt-treated PSS/PDADMAC thin films are expected to show different behaviors in terms of the physical adsorption of various functional substances, cell adhesion and proliferation, and chemical reaction activity.

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

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

    SciTech Connect

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

    1988-09-01

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

  4. Corrosion Fatigue Behavior of 316LN SS in Acidified Sodium Chloride Solution at Applied Potential

    NASA Astrophysics Data System (ADS)

    Poonguzhali, A.; Pujar, M. G.; Mallika, C.; Mudali, U. Kamachi

    2015-05-01

    The influence of acidified 1 M NaCl solution by addition of 2 ml/L of HCl on the cyclic plastic deformation of AISI Type 316LN SS containing 0.07 wt.% and 0.22 wt.% N was investigated as a function of the applied potentials. The corrosion fatigue (CF) behavior of stainless steel (SS) was explained vis-a-vis the dislocation behavior, the propensity to form microcracks, and the evolution of the current transients based on the studies carried out at both room-temperature and boiling conditions. CF experiments were conducted using round tensile specimens at a stress ratio of 0.5 and a frequency of 0.1 Hz. Two different kinds of damage mechanisms were observed (I) the damage mechanism in the stable-passive state was correlated with the localization of the anodic dissolution due to a depassivation-repassivation process, whereas (II) the cyclic stress induced pitting corrosion in the metastable pitting state, which resulted in formation of microcracks. The study of the microcracking process and its evolution is a key to the physical mechanism by which the fatigue life of stainless steels would be affected in an aqueous corrosive solution under the applied potential.

  5. A comparative study on the electrochemical corrosion behavior of iron and X-65 steel in 4.0 wt % sodium chloride solution after different exposure intervals.

    PubMed

    Sherif, El-Sayed M

    2014-07-09

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

  6. Deliquescence and efflorescence of calcium perchlorate: An investigation of stable aqueous solutions relevant to Mars

    NASA Astrophysics Data System (ADS)

    Nuding, D. L.; Rivera-Valentin, E. G.; Davis, R. D.; Gough, R. V.; Chevrier, V. F.; Tolbert, M. A.

    2014-11-01

    Calcium perchlorate (Ca(ClO4)2) is a highly deliquescent salt that may exist on the surface of present-day Mars; however, its water uptake properties have not been well characterized at temperatures and relative humidity conditions relevant to Mars. Here, we quantify the deliquescent relative humidity (DRH) and efflorescent relative humidity (ERH) of Ca(ClO4)2 as a function of temperature (223-273 K) to elucidate its behavior on the surface of Mars. A Raman microscope equipped with an environmental cell was used to simulate Mars relevant temperature and relative humidity conditions and monitor deliquescence (solid to aqueous) and efflorescence (aqueous to solid) phase transitions of Ca(ClO4)2. Deliquescence and efflorescence were monitored visually using optical images and spectroscopically using Raman microscopy. We find that there is a wide range of deliquescence RH values between 5% and 55% RH. This range is due to the formation of hydrates in different temperatures regimes, with the higher DRH values occurring at the lowest temperatures. Experimental deliquescence results were compared to a thermodynamic model for three hydration states of Ca(ClO4)2. The model predicts that the higher hydration states deliquesce at a higher RH than the lower hydration states. Calcium perchlorate was found to supersaturate, with lower ERH values than DRH values. The ERH results were less dependent on temperature with an average 15 ± 4%, but values as low as 3 ± 2% were measured at 273 K. Levitation experiments were performed on single particles of Ca(ClO4)2 and Mg(ClO4)2 at 298 K. While efflorescence was observed around 15% RH for Mg(ClO4)2, the efflorescence of Ca(ClO4)2 was not observed, even when exposed to 1% RH at 298 K. Additionally, a 17-h experiment was conducted to simulate a martian subsurface diurnal cycle. This demonstrated Ca(ClO4)2 aqueous solutions can persist without efflorescing for the majority of a martian sol, up to 17 h under Mars temperature heating rates

  7. 9-Anthracene carboxylic acid is more suitable than DIDS for characterization of calcium-activated chloride current during canine ventricular action potential.

    PubMed

    Váczi, Krisztina; Hegyi, Bence; Ruzsnavszky, Ferenc; Kistamás, Kornél; Horváth, Balázs; Bányász, Tamás; Nánási, Péter P; Szentandrássy, Norbert; Magyar, János

    2015-01-01

    Understanding the role of ionic currents in shaping the cardiac action potential (AP) has great importance as channel malfunctions can lead to sudden cardiac death by inducing arrhythmias. Therefore, researchers frequently use inhibitors to selectively block a certain ion channel like 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS) and 9-anthracene carboxylic acid (9-AC) for calcium-activated chloride current (ICl(Ca)). This study aims to explore which blocker is preferable to study ICl(Ca). Whole-cell voltage-clamp technique was used to record ICa,L, IKs, IKr and IK1, while action potentials were measured using sharp microelectrodes. DIDS- (0.2 mM) and 9-AC-sensitive (0.5 mM) currents were identical in voltage-clamp conditions, regardless of intracellular Ca(2+) buffering. DIDS-sensitive current amplitude was larger with the increase of stimulation rate and correlated well with the rate-induced increase of calcium transients. Both drugs increased action potential duration (APD) to the same extent, but the elevation of the plateau potential was more pronounced with 9-AC at fast stimulation rates. On the contrary, 9-AC did not influence either the AP amplitude or the maximal rate of depolarization (V max), but DIDS caused marked reduction of V max. Both inhibitors reduced the magnitude of phase-1, but, at slow stimulation rates, this effect of DIDS was larger. All of these actions on APs were reversible upon washout of the drugs. Increasing concentrations of 9-AC between 0.1 and 0.5 mM in a cumulative manner gradually reduced phase-1 and increased APD. 9-AC at 1 mM had no additional actions upon perfusion after 0.5 mM. The half-effective concentration of 9-AC was approximately 160 μM with a Hill coefficient of 2. The amplitudes of ICa,L, IKs, IKr and IK1 were not changed by 0.5 mM 9-AC. These results suggest that DIDS is equally useful to study ICl(Ca) during voltage-clamp but 9-AC is superior in AP measurements for studying the physiological role of

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

    NASA Technical Reports Server (NTRS)

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

    2004-01-01

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

  9. Separation of mercury from aqueous mercuric chloride solutions by onion skins

    SciTech Connect

    Asai, S.; Konishi, Y.; Tomisaki, H.; Nakanishi, M.

    1986-01-01

    The separation of mercury from aqueous HgCl/sub 2/ solutions by onion skins (outermost coat) was studied both experimentally and theoretically. The distribution equilibria were measured by the batchwise method. The experimental results revealed that onion skin is a useful material for separating mercury from aqueous systems. The distribution data obtained at 25/sup 0/C were analyzed by using the theory based on the law of mass action. The separation of dissolved mercury by onion skins was found to be a process accompanied by an ion-exchange reaction of the cationic complex HgCl/sup +/ and an adsorption of the neutral complex HgCl/sub 2/. The equilibrium constants of the ion-exchange and adsorption processes at 25/sup 0/C and the mercury-binding capacity of onion skins were determined. Further, it was found that the distribution equilibrium of mercury is comparatively insensitive to temperature.

  10. Volume change effect on the salt-finger stability of directionally solidifying ammonium chloride solution

    NASA Astrophysics Data System (ADS)

    Lee, Y. C.; Chen, Falin

    1995-09-01

    The effect of the volume change due to phase transformation on the stability of salt-finger convection of directionally solidifying NH 4Cl aqueous solution cooling from below is investigated. The basic flow, induced by the volume change, not only changes the morphology and the depth of the dendritic mushy layer, but also influences the stability of salt-finger convection. A new mathematical model is proposed, which differs from the previous one mainly on the dynamical condition at the melt/mush interface. This difference not only leads to a less stable state, but can also be crucial to the dynamical behavior of the oscillatory instability mode since the convection cells of this mode are coupled viscously through the interface. In the discussion, special emphasis is placed on the volume change effect on the instability mode competition, which may be influential to the stability characteristics of the subsequent plume convection.

  11. Investigation of factors influencing chloride extraction efficiency during electrochemical chloride extraction from reinforcing concrete

    NASA Astrophysics Data System (ADS)

    Sharp, Stephen R.

    2005-11-01

    Electrochemical chloride extraction (ECE) is an accelerated bridge restoration method similar to cathodic protection, but operates at higher current densities and utilizes a temporary installation. Both techniques prolong the life of a bridge by reducing the corrosion rate of the reinforcing bar when properly applied. ECE achieves this by moving chlorides away from the reinforcement and out of the concrete while simultaneously increasing the alkalinity of the electrolyte near the reinforcing steel. Despite the proven success, significant use of ECE has not resulted in part due to an incomplete understanding in the following areas: (1) An estimation of the additional service life that can be expected following treatment when the treated member is again subjected to chlorides; (2) The cause of the decrease in current flow and, therefore, chloride removal rate during treatment; (3) Influence of water-to-cement (w/c) ratio and cover depth on the time required for treatment. This dissertation covers the research that is connected to the last two areas listed above. To begin examining these issues, plain carbon steel reinforcing bars (rebar) were embedded in portland cement concrete slabs of varying water-to-cement (w/c) ratios and cover depths, and then exposed to chlorides. A fraction of these slabs had sodium chloride added as an admixture, with all of the slabs subjected to cyclical ponding with a saturated solution of sodium chloride. ECE was then used to remove the chlorides from these slabs while making electrical measurements in the different layers between the rebar (cathode) and the titanium mat (anode) to follow the progress of the ECE process. During this study, it was revealed that the resistance of the outer concrete surface layer increases during ECE, inevitably restricting current flow, while the resistance of the underlying concrete decreases or remains constant. During ECE treatment, a white residue formed on the surface of the concrete. Analyses of the

  12. Corrosion behavior of aluminum-alumina composites in aerated 3.5 percent chloride solution

    NASA Astrophysics Data System (ADS)

    Acevedo Hurtado, Paul Omar

    Aluminum based metal matrix composites are finding many applications in engineering. Of these Al-Al2O3 composites appear to have promise in a number of defense applications because of their mechanical properties. However, their corrosion behavior remains suspect, especially in marine environments. While efforts are being made to improve the corrosion resistance of Al-Al2O3 composites, the mechanism of corrosion is not well known. In this study, the corrosion behavior of powder metallurgy processed Al-Cu alloy reinforced with 10, 15, 20 and 25 vol. % Al2O3 particles (XT 1129, XT 2009, XT 2048, XT 2031) was evaluated in aerated 3.5% NaCl solution using microstructural and electrochemical measurements. AA1100-O and AA2024T4 monolithic alloys were also studied for comparison purposes. The composites and unreinforced alloys were subjected to potentiodynamic polarization and Electrochemical Impedance Spectroscopy (EIS) testing. Addition of 25 vol. % Al2O 3 to the base alloys was found to increase its corrosion resistance considerably. Microstructural studies revealed the presence of intermetallic Al2Cu particles in these composites that appeared to play an important role in the observations. Pitting potential for these composites was near corrosion potential values, and repassivation potential was below the corresponding corrosion potential, indicating that these materials begin to corrode spontaneously as soon as they come in contact with the 3.5 % NaCl solution. EIS measurements indicate the occurrence of adsorption/diffusion phenomena at the interface of the composites which ultimately initiate localized or pitting corrosion. Polarization resistance values were extracted from the EIS data for all the materials tested. Electrically equivalent circuits are proposed to describe and substantiate the corrosive processes occurring in these Al-Al2O 3 composite materials.

  13. Can calcium chloride injection facilitate the ageing-derived improvement in the quality of meat from culled dairy cows?

    PubMed

    Bunmee, T; Jaturasitha, S; Kreuzer, M; Wicke, M

    2014-04-01

    This study investigated whether the positive effects of ageing on tenderness of meat from culled dairy cows can be facilitated by CaCl₂. Injections of 250 mM CaCl₂ solution (10% wt/wt) were performed on Longissimus dorsi samples from 32 7-yrs old cows. Samples were vacuum packaged and aged for 0, 1, 3, 5 and 7 days. Ageing alone produced lighter and less red meat with lower shear force, higher myofibrillar fragmentation and tenderness scores but also elevated lipid oxidation. For most traits investigated, CaCl₂-injected meat exhibited similar ageing effects, but drip loss increased with age. The CaCl₂-injected meat had a lower shear force and myofibrillar fragmentation increased more rapidly, but drip loss, off-flavour scores, colour stability and oxidative stability were inferior to untreated meat. Overall, it was found possible to accelerate tenderisation of such meat with CaCl₂, but only at the cost of adverse effects in some other quality traits.

  14. Survival of Bifidobacterium longum immobilized in calcium alginate beads in simulated gastric juices and bile salt solution.

    PubMed

    Lee, K Y; Heo, T R

    2000-02-01

    Bifidobacterium longum KCTC 3128 and HLC 3742 were independently immobilized (entrapped) in calcium alginate beads containing 2, 3, and 4% sodium alginate. When the bifidobacteria entrapped in calcium alginate beads were exposed to simulated gastric juices and a bile salt solution, the death rate of the cells in the beads decreased proportionally with an increase in both the alginate gel concentration and bead size. The initial cell numbers in the beads affected the numbers of survivors after exposure to these solutions; however, the death rates of the viable cells were not affected. Accordingly, a mathematical model was formulated which expressed the influences of several parameters (gel concentration, bead size, and initial cell numbers) on the survival of entrapped bifidobacteria after sequential exposure to simulated gastric juices followed by a bile salt solution. The model proposed in this paper may be useful for estimating the survival of bifidobacteria in beads and establishing optimal entrapment conditions.

  15. Formation of apatitic calcium phosphates in a Na-K-phosphate solution of pH 7.4.

    PubMed

    Tas, A C; Aldinger, F

    2005-02-01

    Poorly crystalline, apatitic calcium phosphate powders have been synthesized by slowly adding a Na- and K-containing reference phosphate solution with a pH value of 7.4 to an aqueous calcium nitrate solution at 37 degrees C. Nano-particulated apatitic powders obtained were shown to contain small amounts of Na and K, which render them more similar in chemical composition to that of the bone mineral. Precipitated and dried powders were found to exhibit self-hardening cement properties when kneaded in a mortar with a sodium citrate- and sodium phosphate-containing starter solution. The same phosphate solution used in powder synthesis was found to be able to partially convert natural, white and translucent marble pieces of calcite (CaCO3) into calcium-deficient hydroxyapatite upon aging the samples in that solution for 3 days at 60 degrees C. Sample characterization was performed by using scanning electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, inductively-coupled plasma atomic emission spectroscopy, and simultaneous thermogravimetry and differential thermal analysis.

  16. Comparative Proteomics of Ovarian Cancer Aggregate Formation Reveals an Increased Expression of Calcium-activated Chloride Channel Regulator 1 (CLCA1)*

    PubMed Central

    Musrap, Natasha; Tuccitto, Alessandra; Karagiannis, George S.; Saraon, Punit; Batruch, Ihor; Diamandis, Eleftherios P.

    2015-01-01

    Ovarian cancer is a lethal gynecological disease that is characterized by peritoneal metastasis and increased resistance to conventional chemotherapies. This increased resistance and the ability to spread is often attributed to the formation of multicellular aggregates or spheroids in the peritoneal cavity, which seed abdominal surfaces and organs. Given that the presence of metastatic implants is a predictor of poor survival, a better understanding of how spheroids form is critical to improving patient outcome, and may result in the identification of novel therapeutic targets. Thus, we attempted to gain insight into the proteomic changes that occur during anchorage-independent cancer cell aggregation. As such, an ovarian cancer cell line, OV-90, was cultured in adherent and non-adherent conditions using stable isotope labeling with amino acids in cell culture (SILAC). Anchorage-dependent cells (OV-90AD) were grown in tissue culture flasks, whereas anchorage-independent cells (OV-90AI) were grown in suspension using the hanging-drop method. Cellular proteins from both conditions were then identified using LC-MS/MS, which resulted in the quantification of 1533 proteins. Of these, 13 and 6 proteins were up-regulated and down-regulated, respectively, in aggregate-forming cells compared with cells grown as monolayers. Relative gene expression and protein expression of candidates were examined in other cell line models of aggregate formation (TOV-112D and ES-2), which revealed an increased expression of calcium-activated chloride channel regulator 1 (CLCA1). Moreover, inhibitor and siRNA transfection studies demonstrated an apparent effect of CLCA1 on cancer cell aggregation. Further elucidation of the role of CLCA1 in the pathogenesis of ovarian cancer is warranted. PMID:26004777

  17. Differential expression of calcium-activated chloride channels (CLCA) gene family members in the small intestine of cystic fibrosis mouse models.

    PubMed

    Leverkoehne, Ina; Holle, Hannah; Anton, Friederike; Gruber, Achim D

    2006-08-01

    Members of the family of calcium-activated chloride channels (CLCA) have been implicated as modulators of the phenotype in cystic fibrosis (CF). Here, the expression levels of the murine mCLCA1, mCLCA2, mCLCA3 and mCLCA4 were quantified by real-time RT-PCR in the small intestines of CF (cftr (tm1Cam), cftr (TgH(neoim)1Hgu)) and wild type C57BL/6, BALB/c, DBA/2 and NMRI mice. Markedly different expression levels of all four CLCA homologs were observed between the different wild type strains. Expression of mCLCA1 and mCLCA4 was similar in CF versus wild type. In contrast, mCLCA3 mRNA copy numbers were increased up to threefold in all CF models. Immunohistochemical detection of mCLCA3 and PAS reactions on consecutive tissue sections identified a similar increase in mCLCA3 expressing goblet cells, suggesting that elevated mRNA copy numbers of mCLCA3 are due to goblet cell hyperplasia rather than transcriptional regulatory events. Increased mCLCA2 mRNA copy numbers, however, were considered more likely to be due to transcriptional upregulation. Changes in mRNA copy numbers were not associated with altered cell kinetics as determined by immunohistochemistry using antibodies to phospho-histone 3 and activated caspase-3. The results suggest that both mCLCA2 and mCLCA3 may act as modifiers of the intestinal phenotype in CF.

  18. Comparative Proteomics of Ovarian Cancer Aggregate Formation Reveals an Increased Expression of Calcium-activated Chloride Channel Regulator 1 (CLCA1).

    PubMed

    Musrap, Natasha; Tuccitto, Alessandra; Karagiannis, George S; Saraon, Punit; Batruch, Ihor; Diamandis, Eleftherios P

    2015-07-10

    Ovarian cancer is a lethal gynecological disease that is characterized by peritoneal metastasis and increased resistance to conventional chemotherapies. This increased resistance and the ability to spread is often attributed to the formation of multicellular aggregates or spheroids in the peritoneal cavity, which seed abdominal surfaces and organs. Given that the presence of metastatic implants is a predictor of poor survival, a better understanding of how spheroids form is critical to improving patient outcome, and may result in the identification of novel therapeutic targets. Thus, we attempted to gain insight into the proteomic changes that occur during anchorage-independent cancer cell aggregation. As such, an ovarian cancer cell line, OV-90, was cultured in adherent and non-adherent conditions using stable isotope labeling with amino acids in cell culture (SILAC). Anchorage-dependent cells (OV-90AD) were grown in tissue culture flasks, whereas anchorage-independent cells (OV-90AI) were grown in suspension using the hanging-drop method. Cellular proteins from both conditions were then identified using LC-MS/MS, which resulted in the quantification of 1533 proteins. Of these, 13 and 6 proteins were up-regulated and down-regulated, respectively, in aggregate-forming cells compared with cells grown as monolayers. Relative gene expression and protein expression of candidates were examined in other cell line models of aggregate formation (TOV-112D and ES-2), which revealed an increased expression of calcium-activated chloride channel regulator 1 (CLCA1). Moreover, inhibitor and siRNA transfection studies demonstrated an apparent effect of CLCA1 on cancer cell aggregation. Further elucidation of the role of CLCA1 in the pathogenesis of ovarian cancer is warranted.

  19. Small volume resuscitation with hypertonic sodium chloride solution in cattle undergoing surgical correction of abomasal volvulus.

    PubMed

    Sickinger, M; Doll, K; Roloff, N C; Halekoh, U

    2014-09-01

    A randomized clinical trial was conducted to compare the efficacy of rapid intravenous (IV) infusion of a 7.2% hypertonic saline solution with that of continuous application of an isotonic solution in stabilizing the circulation of cows with abomasal volvulus. Cattle treated with hypertonic saline had a significantly greater reduction in volume deficit within the first 10 min of therapy than cows treated with isotonic saline (from 5.9 ± 4.8 to 2.1 ± 4.4 L/100 kg vs. 7.0 ± 4.5 to 4.9 ± 3.8 L/100 kg, respectively). The central venous pressure (CVP) of the cows given the hypertonic saline rose within the first 10 min of therapy from 7.3 ± 3.5 to 10.8 ± 3.4 cm H2O, while the CVP of the cattle treated with isotonic saline did not increase significantly during this time. Sixty minutes after the start of the infusion, the CVP of the isotonic group was still significantly lower than that of the hypertonic group (9.5 ± 2.1 vs. 10.3 ± 3.3 cm H2O, respectively). Within the first 60 min, the base excess decreased from 5.5 ± 6.9 to 4.7 ± 6.2 mmol/L in the hypertonic group whereas it increased from 5.6 ± 5.7 to 6.8 ± 5.4 mmol/L in the isotonic group. These results suggest that for cows with abomasal volvulus, IV therapy with hypertonic saline may improve the haemodynamic and circulatory situation considerably faster and more effectively than continuous infusion with isotonic saline.

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

    NASA Astrophysics Data System (ADS)

    Braun, Reinhold

    2016-03-01

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

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

    SciTech Connect

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

    1988-03-01

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

  2. A thermodynamic solution model for calcium carbonate: Towards an understanding of multi-equilibria precipitation pathways.

    PubMed

    Donnet, Marcel; Bowen, Paul; Lemaître, Jacques

    2009-12-15

    Thermodynamic solubility calculations are normally only related to thermodynamic equilibria in solution. In this paper, we extend the use of such solubility calculations to help elucidate possible precipitation reaction pathways during the entire reaction. We also estimate the interfacial energy of particles using only solubility data by a modification of Mersmann's approach. We have carried this out by considering precipitation reactions as a succession of small quasi-equilibrium states. Thus possible equilibrium precipitation pathways can be evaluated by calculating the evolution of surface charge, particle size and/or interfacial energy during the ongoing reaction. The approach includes the use of the Kelvin's law to express the influence of particle size on the solubility constant of precipitates, the use of Nernst's law to calculate surface potentials from solubility calculations and relate this to experimentally measured zeta potentials. Calcium carbonate precipitation and zeta potential measurements of well characterised high purity calcite have been used as a model system to validate the calculated values. The clarification of the change in zeta potential on titration illustrates the power of this approach as a tool for reaction pathway prediction and hence knowledge based tailoring of precipitation reactions.

  3. XANES Demonstrates the Release of Calcium Phosphates from Alkaline Vertisols to Moderately Acidified Solution.

    PubMed

    Andersson, Karl O; Tighe, Matthew K; Guppy, Christopher N; Milham, Paul J; McLaren, Timothy I; Schefe, Cassandra R; Lombi, Enzo

    2016-04-19

    Calcium phosphate (CaP) minerals may comprise the main phosphorus (P) reserve in alkaline soils, with solubility dependent on pH and the concentration of Ca and/or P in solution. Combining several techniques in a novel way, we studied these phenomena by progressively depleting P from suspensions of two soils (low P) using an anion-exchange membrane (AEM) and from a third soil (high P) with AEM together with a cation-exchange membrane. Depletions commenced on untreated soil, then continued as pH was manipulated and maintained at three constant pH levels: the initial pH (pHi) and pH 6.5 and 5.5. Bulk P K-edge X-ray absorption near-edge structure (XANES) spectroscopy revealed that the main forms of inorganic P in each soil were apatite, a second more soluble CaP mineral, and smectite-sorbed P. With moderate depletion of P at pHi or pH 6.5, CaP minerals became more prominent in the spectra compared to sorbed species. The more soluble CaP minerals were depleted at pH 6.5, and all CaP minerals were exhausted at pH 5.5, showing that the CaP species present in these alkaline soils are soluble with decreases of pH in the range achievable by rhizosphere acidification. PMID:26974327

  4. Defining the intramembrane binding mechanism of sarcolipin to calcium ATPase using solution NMR spectroscopy.

    PubMed

    Buffy, Jarrod J; Buck-Koehntop, Bethany A; Porcelli, Fernando; Traaseth, Nathaniel J; Thomas, David D; Veglia, Gianluigi

    2006-04-28

    Sarcolipin (SLN) is an integral membrane protein that is expressed in both skeletal and cardiac muscle, where it inhibits SERCA (calcium ATPase) by lowering its apparent Ca2+ affinity in a manner similar to that of its homologue phospholamban (PLN). We use solution NMR to map the structural changes occurring within SLN upon interaction with the regulatory target, SERCA, co-reconstituting the two proteins in dodecylphosphocholine (DPC) detergent micelles, a system that preserves the native structure of SLN and the activity of SERCA, with the goal of comparing these interactions with those of the previously studied PLN-SERCA complex. Our analysis of the structural dynamics of SLN in DPC micelles shows this polypeptide to be partitioned into four subdomains: a short unstructured N terminus (residues 1-6), a short dynamic helix (residues 7-14), a more rigid helix (residues 15-26), and an unstructured C terminus (residues 27-31). Upon addition of SERCA, the different domains behave according to their dynamics, molding onto the surface of the enzyme. Remarkably, each domain of SLN behaves in a manner similar to that of the corresponding domains in PLN, supporting the hypothesis that both SLN and PLN bind SERCA in the same groove and with similar mechanisms.

  5. NMR sequential assignments and solution structure of chlorotoxin, a small scorpion toxin that blocks chloride channels.

    PubMed

    Lippens, G; Najib, J; Wodak, S J; Tartar, A

    1995-01-10

    The solution structure of chlorotoxin, a small toxin purified from the venom of the Leiurus quinquestriatus scorpion, has been determined using 2D 1H NMR spectroscopy. Analysis of the NMR data shows that the structure consists of a small three-stranded antiparallel beta-sheet packed against an alpha-helix, thereby adopting the same fold as charybdotoxin and other members of the short scorpion toxin family [Arseniev et al. (1984) FEBS Lett. 165, 57-62; Martins et al. (1990) FEBS Lett. 260, 249-253; Bontems et al. (1991) Science 254, 1521-1523]. Three disulfide bonds of chlorotoxin (Cys5-Cys28, Cys16-Cys33, and Cys20-Cys35), cross-linking the alpha-helix to the beta-sheet, follow the common pattern found in the other short scorpion toxins. The fourth disulfide bridge (Cys2-Cys19) links the small N-terminal beta strand to the rest of the molecule, in contrast to charybdotoxin where this disulfide bridge is absent and the first strand interacts with the rest of the molecule by several contacts between hydrophobic residues. Another structural difference between chlorotoxin and charybdotoxin is observed at the level of the alpha-beta turn. This difference is accompanied by a change in the electrostatic potential surface, which is largely positive at the level of this turn in chlorotoxin, whereas no such positive potential surface can be found at the same position in charybdotoxin. In the latter protein, the positive surface is formed by different charged residues situated on the solvent-exposed site of the C-terminal beta-sheet.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. Calcium binding to an aquatic fulvic acid

    NASA Astrophysics Data System (ADS)

    Paxéus, Nicklas; Wedborg, Margareta

    The degree of binding of calcium to aquatic fulvic acid from the Göta River was estimated from potentiometric titrations. A pH-glass electrode and a calcium-selective electrode were used to monitor the free concentrations of the competing, central ions. The ionic strength and the temperature were maintained constant at 0.1 M and 25°C. The total concentration of fulvic acid was maintained at approximately 1 g 1-1, while the total calcium concentration was varied within the range 0-10-3 M. Two types of titrations were carried out: (1) back titration with hydrochloric acid from basic solution, roughly within the pH range 10.5-2.5; (2) titration with calcium chloride at a constant total hydrogen ion concentration. The model applied for the calcium binding was an extension of our previous model for the acid-base behaviour.

  7. Influence of the current density on the electrochemical treatment of concentrated 1-butyl-3-methylimidazolium chloride solutions on diamond electrodes.

    PubMed

    Marcionilio, Suzana M L de Oliveira; Alves, Gisele M; E Silva, Rachel B Góes; Marques, Pablo J Lima; Maia, Poliana D; Neto, Brenno A D; Linares, José J

    2016-10-01

    This paper focuses on the influence of the current density treatment of a concentrated 1-butyl-3-methylimidazolium chloride (BMImCl) solution on an electrochemical reactor with a boron-doped diamond (BDD) anode. The decrease in the total organic carbon (TOC) and the BMImCl concentration demonstrate the capability of BDD in oxidizing ionic liquids (ILs) and further mineralizing (to CO2 and NO3 (-)) more rapidly at higher current densities in spite of the reduced current efficiency of the process. Moreover, the presence of Cl(-) led to the formation of oxychlorinated anions (mostly ClO3 (-) and ClO4 (-)) and, in combination with the ammonia generated in the cathode from the nitrate reduction, chloramines, more intensely at higher current density. Finally, the analysis of the intermediates formed revealed no apparent influence of the current density on the BMImCl degradation mechanism. The current density presents therefore a complex influence on the IL treatment process that is discussed throughout this paper.

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

    PubMed

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

    2016-01-25

    Cuprous chloride (CuCl) was examined as a precipitant to remove iodide (I(-)) from aqueous solutions. The effects of the dosage of CuCl, reaction time, initial concentrations of I(-) and bicarbonate (HCO3(-)) on I(-) removal were investigated. The results showed that the optimized removal efficiency of I(-) reached approximately 95.8% when the dosage was 150 mg/L, the initial I(-) concentration ranged from 5 to 40 mg/L and the reaction time was 15 min. The removal efficiency decreased from 95.8% to 76.0% with the addition of HCO3(-) at a concentration in the range of 0-107 mg/L. Furthermore, the dissociation of CuCl, the disproportionation reaction of Cu(+), the precipitation of cuprous iodide (CuI) and cuprous oxide (Cu2O), and the formations of copper sulfide (CuxS, 1≤x<2) were identified as the primary reactions using the PHREEQC software and the measurements of water quality parameters under various conditions. X-rays photoelectron spectroscopy (XPS) analysis was performed before and after the reaction, helping to elucidate the reaction mechanism. This study can provide a promising method to address radioactive I(-) pollution in water. PMID:26448493

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

    PubMed

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

    2016-01-25

    Cuprous chloride (CuCl) was examined as a precipitant to remove iodide (I(-)) from aqueous solutions. The effects of the dosage of CuCl, reaction time, initial concentrations of I(-) and bicarbonate (HCO3(-)) on I(-) removal were investigated. The results showed that the optimized removal efficiency of I(-) reached approximately 95.8% when the dosage was 150 mg/L, the initial I(-) concentration ranged from 5 to 40 mg/L and the reaction time was 15 min. The removal efficiency decreased from 95.8% to 76.0% with the addition of HCO3(-) at a concentration in the range of 0-107 mg/L. Furthermore, the dissociation of CuCl, the disproportionation reaction of Cu(+), the precipitation of cuprous iodide (CuI) and cuprous oxide (Cu2O), and the formations of copper sulfide (CuxS, 1≤x<2) were identified as the primary reactions using the PHREEQC software and the measurements of water quality parameters under various conditions. X-rays photoelectron spectroscopy (XPS) analysis was performed before and after the reaction, helping to elucidate the reaction mechanism. This study can provide a promising method to address radioactive I(-) pollution in water.

  10. Bioactivity of porous titanium with hydrogen peroxide solution with or without tantalum chloride treatment at a low temperature.

    PubMed

    Zhao, Chaoyong; Liang, Kailu; Tan, Jing; Xiang, Zhou; Fan, Hongsong; Zhang, Xingdong

    2013-04-01

    In this study, porous titanium was treated by a hydrogen peroxide solution with (HT) or without (HO) tantalum chloride at a low temperature to endow its bioactivity. The microstructure, film stability and in vitro and in vivo bioactivity of HT-treated and HO-treated porous titanium were investigated, and the non-treated one was used as control. After HT treatment, a well-crystallized titania nanoparticle film consisting of anatase phase with good film stability was formed on the surface of porous titanium, and the tantalum element appeared in the film, while the HO-treated porous titanium surface showed a dual structure with well-aligned nanorods as an outer layer and condensed nanoparticles as an inner layer consisting of a mixture of well-crystallized anatase and rutile phases. In vitro bioactivity assessment showed that both HT- and HO-treated porous titanium possessed high apatite-forming ability. More importantly, after implantation in the dorsal muscles of dogs, the HT- and HO-treated implants induced ectopic bone formation in its inner pores after 5 months, while the non-treated one did not. The present study showed that HT-treated porous titanium possessed good film stability and bioactivity to be used as bone repair materials in clinic under load-bearing conditions.

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

    NASA Astrophysics Data System (ADS)

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

    2016-08-01

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

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

    PubMed

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

    2016-07-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2016-08-01

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

  15. Re-passivation Potential of Alloy 22 in Chloride plus Nitrate Solutions using the Potentiodynamic-Galvano-static-Potentiostatic Method

    SciTech Connect

    Evans, Kenneth J.; Rebak, Raul B.

    2007-07-01

    In general, the susceptibility of Alloy 22 to suffer crevice corrosion is measured using the Cyclic Potentiodynamic Polarization (CPP) technique. This is a fast technique that gives rather accurate and reproducible values of re-passivation potential (ER1) in most cases. In the fringes of susceptibility, when the environment is not highly aggressive, the values of re-passivation potential using the CPP technique may not be highly reproducible, especially because the technique is fast. To circumvent this, the re-passivation potential of Alloy 22 was measured using a slower method that combines Potentiodynamic-Galvano-static-Potentiostatic steps (called here the Tsujikawa-Hisamatsu Electrochemical or THE method). The THE method applies the charge to the specimen in a more controlled way, which may give more reproducible re-passivation potential values, especially when the environment is not aggressive. The values of re-passivation potential of Alloy 22 in sodium chloride plus potassium nitrate solutions were measured using the THE and CPP methods. Results show that both methods yield similar values of re-passivation potential, especially under aggressive conditions. (authors)

  16. The effect of intravenous magnesium hypophosphite in calcium borogluconate solution on the serum concentration of inorganic phosphorus in healthy cows.

    PubMed

    Braun, U; Jehle, W

    2007-03-01

    The goal of this study was to determine the effect of intravenous (IV) administration of phosphite on the serum concentration of inorganic phosphorus in cows. Twelve clinically healthy cows were divided into four groups of three. All cows received 600 mL of a 40% calcium borogluconate solution; three cows each received this as a rapid (20 min) IV infusion with and without 6% magnesium hypophosphite, and three other cows each received this as a slow IV infusion (8 h) with and without 6% magnesium hypophosphite. Samples of blood were collected for the determination of serum concentrations of calcium, inorganic phosphorus and magnesium before and 10, 20, 40, 60 and 90 min and 2, 3, 4, 5, 6, 7, 8, 24, 48 and 72 h after the start of treatment. The concentration of calcium increased after treatment in all cows but the increase was most rapid in cows that received the rapid infusion. In cows that received the rapid IV infusion containing magnesium hypophosphite, the mean concentration of inorganic phosphorus decreased significantly 3-4 h after treatment compared with initial serum levels. The serum concentration of inorganic phosphorus did not change significantly in cows that received the rapid IV solution without magnesium hypophosphite or the slow IV infusion with or without magnesium hypophosphite. The serum concentration of magnesium increased after treatment in all cows receiving magnesium hypophosphite but remained unchanged in the others. The rapid infusion of calcium borogluconate without magnesium hypophosphite made all three cows anorexic and hypercalcaemic and the slow infusion made 1/3 anorexic. It is concluded that the IV administration of a calcium solution containing magnesium hypophosphite does not increase the serum concentration of inorganic phosphorus.

  17. The challenge of coronary calcium on coronary computed tomographic angiography (CCTA) scans: effect on interpretation and possible solutions.

    PubMed

    Andrew, Makmur; John, Hoe

    2015-12-01

    Coronary calcium seen on coronary computed tomographic angiography (CCTA) scans is a common diagnostic challenge which can make interpretation difficult. It is the most common cause of false positive (FP) results from CCTA compared with invasive coronary angiography (ICA), and affects the positive predictive results. At the same time, coronary calcium can result in false negative (FN) results, and this again can affect the reported diagnostic accuracy of CCTA, as the high negative predictive value of CCTA compared to ICA is one of its strengths. This paper reviews the reasons that coronary calcium can cause FP and FN results, and the effects of the morphologies and sizes of the calcified plaques, with particular regard to their relationship with the visualization of the contrast-filled lumen of the coronary artery. Some possible solutions to overcome the limitations of reading CCTA scans with calcified plaques also are discussed, with a view to improving the accuracy of interpreting and reporting CCTA scans; these solutions include using the degree of residual visible contrast-filled lumen to help assess the likelihood of significant associated coronary stenosis, and applying newer technical developments such as dual-energy imaging and volume calcium subtraction.

  18. Improving evaporators for crystallizing solutions

    SciTech Connect

    Korbanov, V.N.; Gaidash, N.I.; Kibitkin, V.N.; Mitkevich, E.M.; Nikolenko, V.N.

    1985-07-01

    The authors describe and evaluate the new evaporators with forced circulation and a heat exchange surface of 630 m that have recently been introduced for the production of calcium chloride from still wastes in soda plants. A diagram illustrates the construction of the new apparatus and charts present data on the dependence of heat transfer on the thickness of the walls of the heating pipes, the dependence of the entrainment of calcium chloride by secondary steam on the level of the solution in the vacuum aparatus, and on the performance of the evaporator over time.

  19. The effect of the electrochemical chloride extraction treatment on steel-reinforced mortar. Part II: Microstructural characterization

    SciTech Connect

    Marcotte, T.D.; Hansson, C.M.; Hope, B.B.

    1999-10-01

    A study has been made of the changes in cement composition and microstructures resulting from electrochemical chloride extraction applied to mortar samples in which the chlorides were added with the mixing water, ingressed by ponding with an NaCl solution, or both. After exposure for 1 year, specimens with and without chlorides were subjected to an electrochemical chloride extraction treatment. Microstructural analyses of fracture surfaces through the steel/mortar interface revealed a significant alteration of the cementitious phases. In untreated samples, calcium-silicon-rich phases consistent with Types I and II calcium silicate hydrate were observed. After the extraction treatment, these phases were not detectable and instead, sodium-rich, iron-rich, and calcium-aluminum-rich phases were observed.

  20. [pH, sodium, potassium, magnesium, calcium, phosphate and chloride in the rumen and abomasal contents of cows with abomasal displacement].

    PubMed

    Geishauser, T; Reiche, D; Seeh, C; Thünker, B; Verwohlt, S; Failing, K

    1996-01-01

    Ruminal and abomasal contents were collected from cows with left abomasal displacement (L), right abomasal displacement (R-), or abomasal volvulus (R+), before the abomasum was corrected, as well as one and three days later, pH and concentrations of sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), phosphate (P), and chloride (Cl) were determined. Results were compared with those from healthy control cattle fed a balanced diet. Ruminal concentrations of Na and Ca were reduced in cattle with abomasal displacement, whereas those of K, P and Cl were increased, and those of Mg and pH remained nearly unchanged. Concentrations of K and P before abomasal correction were lower in cattle with L than in those with R+, and declined after the correction. Concentrations of Cl decreased continuously after the abomasum was corrected in cattle with L, whereas they increased after replacement in cattle with R and declined later. These findings imply that cattle with abomasal displacement took up less feed before surgical correction and that ruminal contents backed up in the rumen, whereby the backup was less with L than with R+, and that the backed-up contents passed on after the abomasum was corrected. The results also indicate that a reflux of abomasal contents into the rumen took place in cattle with all forms of abomasal displacement, whereby with R+ increased amounts of abomasal contents passed into the rumen following correction and were then later passed out. Compared to controls, abomasal concentrations of Cl were increased in cattle with displacement and the concentrations of K, Mg, Ca, and P were reduced. Before abomasal correction, pH was decreased in cattle with L and unchanged in those with R- and R+. The concentrations of Na and K before correction in L were lower than those with R+, whereas the concentrations of K, Mg, Ca, and P were higher. After abomasal correction, the concentrations of Na declined, and those of K, Mg, Ca, and P increased. On the third day

  1. Development and validation of HTS assay for screening the calcium-activated chloride channel modulators in TMEM16A stably expressed CHO cells.

    PubMed

    Qi, Jinlong; Wang, Yuan; Liu, Yani; Zhang, Fan; Guan, Bingcai; Zhang, Hailin

    2014-02-01

    Calcium-activated chloride channels (CaCCs), for example TMEM16A, are widely expressed in a variety of tissues and are involved in many important physiological functions. We developed and validated an atomic absorption spectroscopy (AAS)-based detection system for high-throughput screening (HTS) of CaCC modulators. With this assay, Cl(-) flux from CHO cells stably transfected with TMEM16A is assayed indirectly, by measuring excess silver ions (Ag(+)) in the supernatant of AgCl precipitates. The screening process involved four steps: (1) TMEM16A CHO cells were incubated in high-K(+) and high-Cl(-) buffer with test compounds, and with ionomycin as Ca(2+) ionophore, for 12 min; (2) cells were washed with a low-K(+), Cl(-)-free and Ca(2+)-free buffer; (3) CaCC/TMEM16A were activated in high-K(+), Cl(-)-free buffer with ionomycin (10 μmol L(-1)) for 12 min; and (4) excess Ag(+) concentration was measured using an ion channel reader (ICR, an AAS system). The assay can be used to screen CaCC activators and inhibitors at the same time. With this assay, positive control drugs, including NPPB, CaCCinh-A01, flufenamic acid (Flu) and Eact, all had good concentration-dependent effects on CaCC/TMEM16A. NPPB and CaCCinh-A01 inhibited the CaCC/TMEM16A currents completely at 300 μmol L(-1), with IC50 values of 39.35 ± 4.72 μmol L(-1) and 6.35 ± 0.27 μmol L(-1), respectively; and Eact, activated CaCC/TMEM16A, with an EC50 value of 3.92 ± 0.87 μmol L(-1).

  2. Effect of Azadirachta indica (neem), sodium thiosulphate and calcium chloride on changes in nitrogen transformations and inhibition of nitrification in soil incubated under laboratory conditions.

    PubMed

    Abbasi, M Kaleem; Hina, Munazza; Tahir, Majid Mahmood

    2011-03-01

    A laboratory experiment was conducted to examine the effects of nitrification inhibitors (NIs) neem seed-cake (Azadirachta indica) (NSC), sodium thiosulphate (Na₂S₂O₃) and calcium chloride (CaCl₂) on changes in NH₄(+)⁻N, inhibition of nitrification and recovery of applied nitrogen (N) in soil. Surface soil samples of 0-15 cm were collected from an arable field, amended with urea N (UN) at the rate 200 mg N kg⁻¹, UN+NSC, UN+Na₂S₂O₃ and UN+CaCl₂ and incubated at 22°C periodically over 50 d. Soil without any amendment was used as check (control). Results indicated that more than 58% of N applied as NH₄⁻ disappeared over a period of 50 d from the soil mineral-N pool. Some of this N (21%) was accumulated as NO₃⁻-N while the remaining N was unaccounted for. Addition of nitrification inhibitors NSC, Na₂S₂O₃, and CaCl₂ resulted in a decrease in the extent of NH₄(+) disappearance by 35%, 44% and 30%, respectively. In the treatment receiving UN alone, 56 mg NO₃⁻-N kg⁻¹ was accumulated over 50 d (maximum 93 mg kg⁻¹) indicated an active nitrification. Application of nitrification inhibitors NSC, Na₂S₂O₃, and CaCl₂ with UN inhibited nitrification by 54%, 64%, and 59%, respectively. Apparent N recovery (ANR) in the treatment receiving UN alone was 63% that substantially increased to 83%, 89% and 76% in the treatments receiving UN+NSC, UN+Na₂S₂O₃, and UN+CaCl₂, respectively indicating 32%, 41% and 20% increase in N recovery. Among three NIs tested, Na₂S₂O₃ proved superior in inhibiting nitrification and increasing ANR. The study demonstrated that application of NSC, Na₂S₂O₃, and CaCl₂ which are cheap and easily available NIs inhibited nitrification and improved N recovery efficiency of applied N in an arable soil very effectively. It is suggested that these inhibitors should be tested under field conditions for increasing NUE and improving crop productivity.

  3. Effect of Azadirachta indica (neem), sodium thiosulphate and calcium chloride on changes in nitrogen transformations and inhibition of nitrification in soil incubated under laboratory conditions.

    PubMed

    Abbasi, M Kaleem; Hina, Munazza; Tahir, Majid Mahmood

    2011-03-01

    A laboratory experiment was conducted to examine the effects of nitrification inhibitors (NIs) neem seed-cake (Azadirachta indica) (NSC), sodium thiosulphate (Na₂S₂O₃) and calcium chloride (CaCl₂) on changes in NH₄(+)⁻N, inhibition of nitrification and recovery of applied nitrogen (N) in soil. Surface soil samples of 0-15 cm were collected from an arable field, amended with urea N (UN) at the rate 200 mg N kg⁻¹, UN+NSC, UN+Na₂S₂O₃ and UN+CaCl₂ and incubated at 22°C periodically over 50 d. Soil without any amendment was used as check (control). Results indicated that more than 58% of N applied as NH₄⁻ disappeared over a period of 50 d from the soil mineral-N pool. Some of this N (21%) was accumulated as NO₃⁻-N while the remaining N was unaccounted for. Addition of nitrification inhibitors NSC, Na₂S₂O₃, and CaCl₂ resulted in a decrease in the extent of NH₄(+) disappearance by 35%, 44% and 30%, respectively. In the treatment receiving UN alone, 56 mg NO₃⁻-N kg⁻¹ was accumulated over 50 d (maximum 93 mg kg⁻¹) indicated an active nitrification. Application of nitrification inhibitors NSC, Na₂S₂O₃, and CaCl₂ with UN inhibited nitrification by 54%, 64%, and 59%, respectively. Apparent N recovery (ANR) in the treatment receiving UN alone was 63% that substantially increased to 83%, 89% and 76% in the treatments receiving UN+NSC, UN+Na₂S₂O₃, and UN+CaCl₂, respectively indicating 32%, 41% and 20% increase in N recovery. Among three NIs tested, Na₂S₂O₃ proved superior in inhibiting nitrification and increasing ANR. The study demonstrated that application of NSC, Na₂S₂O₃, and CaCl₂ which are cheap and easily available NIs inhibited nitrification and improved N recovery efficiency of applied N in an arable soil very effectively. It is suggested that these inhibitors should be tested under field conditions for increasing NUE and improving crop productivity. PMID:21146192

  4. Effects of postmortem calcium chloride injection on meat palatability traits of strip loin steaks from cattle supplemented with or without zilpaterol hydrochloride.

    PubMed

    Rodas-González, A; Pflanzer, S B; Garmyn, A J; Martin, J N; Brooks, J C; Knobel, S M; Johnson, B J; Starkey, J D; Rathmann, R J; de Felicio, P E; Streeter, M N; Yates, D A; Hodgen, J M; Hutcheson, J P; Miller, M F

    2012-10-01

    An experiment was conducted to determine the effects of zilpaterol hydrochloride mM supplementation (ZH; 8.3 mg/kg on a DM basis for 20 d) and calcium chloride injection [CaCl(2), 200 at 5% (wt/wt) at 72 h postmortem] on palatability traits of beef (Bos taurus) strip loin steaks. Select (USDA) strip loins were obtained from control (no ZH = 19) and ZH-supplemented carcasses (n = 20). Right and left sides were selected alternatively to serve as a control (no INJ) or CaCl(2)-injected (INJ) and stored at 4°C. Before injecting the subprimals (72 h postmortem), 2 steaks were cut for proximate, sarcomere length, and myofibrillar fragmentation index (MFI) analyses. At 7 d postmortem each strip loin was portioned into steaks, vacuum packaged, and aged for the appropriate period for Warner-Bratzler shear force (WBSF; 7, 14, 21, and 28 d postmortem), trained sensory analysis (14 and 21 d postmortem), purge loss (7 d), and MFI (3, 7, 14, 21, and 28 d postmortem). Results indicated steaks from both ZH supplementation and INJ had reduced WBSF values as days of postmortem aging increased. The WBSF values of ZH steaks were greater (P < 0.05) than no ZH steaks at each postmortem aging period. The INJ steaks had lower WBSF values (P < 0.05) than non-injected steaks. A greater percentage (91 vs. 71%) of steaks had WBSF values < 4.6 kg from steers with no ZH supplementation at 7 d postmortem, but the percentage did not differ (P > 0.05) due to ZH at 14, 21, or 28 d or due to INJ at any aging period. Trained panelists rated tenderness less in ZH steaks than steaks with no ZH at 14 d and 21 d. However, INJ improved (P < 0.05) the tenderness ratings and flavor intensity of the trained panelists, compared with their non-injected cohorts at 21 d. Zilpaterol hydrochloride supplementation reduced (P < 0.05) MFI values, but INJ resulted in greater (P < 0.05) MFI values compared with no INJ. Subprimals from ZH and INJ showed greater purge loss (P < 0.05). Although no interactions were found

  5. Structure and Stability of Long Rod-like Dodecyltrimethylammonium Chloride Micelles in Solutions of Hydroxybenzoates: A Molecular Dynamics Simulation Study.

    PubMed

    Gujt, Jure; Bešter-Rogač, Marija; Spohr, Eckhard

    2016-08-16

    The relative position of the hydroxylic and carboxylic groups in the isomeric hydroxybenzoate (HB) anions is experimentally known to have a large impact on the thermodynamics of micellization of cationic surfactants, such as dodecyltrimethylammonium chloride (DTAC), and on the structure of the resulting micelles. To understand the effect of the different isomers on the molecular level, we employed atomistic molecular dynamics simulations to study systems containing infinitely long cylindrical DTAC micelles in aqueous solutions of the sodium salts of all three isomers of HB at a temperature and a pressure of 298.15 K and 1 atm. In all studied systems, the number of DTAC unimers is identical to the number of HB anions. At this concentration, the initially cylindrical micelles remain stable, irrespective of the nature of the isomer, whereas micelles rapidly disintegrated in the absence of HB anions. The HB isomers decrease the line density of unimers along the micellar axis and its concomitant thickness in the order o-HB > m-HB > p-HB. It is further observed that o-HB anions penetrate more deeply into the micellar core, induce a more ordered internal structure of the micelle, and are oriented more strongly than the other two isomers. In addition, the ortho isomer shows two different preferential orientations with respect to the radial direction of the cylindrical micelle; it can either be incorporated almost completely into the micelle or it can be attached through hydrogen bonding to one of those o-HB anions that are already incorporated into the micelle, and thus stick out of the micellar surface. PMID:27442259

  6. Concentration dependence of ionic conductance measured with ion-selective sub-micro pipette probes in aqueous sodium and potassium chloride solutions

    NASA Astrophysics Data System (ADS)

    Son, J. W.; Takami, T.; Lee, J.-K.; Kawai, T.; Park, B. H.

    2011-07-01

    Selective ionic currents in aqueous sodium and potassium chloride solutions with concentrations from 0.01 M to 1.0 M were measured using sub-micro pipette probes in which a poly(vinyl chloride) film containing crown ethers selectively filtered sodium or potassium ions. The selective ionic currents were monitored with a sub-picoampere current measurement system developed from the techniques of TΩ-gap impedance scanning tunneling microscopy. The ionic currents increased with the concentration of the corresponding solution, and thus these sub-micro pipette probes can be applied to detect local ionic concentration of a specific ion in living cells with ionic concentration higher than 0.1 M.

  7. Influence of cross-fostering on preference for calcium chloride in C57BL/6J and PWK/PhJ mice.

    PubMed

    Voznesenskaya, Anna; Tordoff, Michael G

    2013-10-01

    We investigated whether maternal influences during the suckling period alter the avidity for calcium, using as models mice from the calcium-preferring PWK/PhJ strain and the calcium-avoiding C57BL/6J strain. We found that milk collected from PWK/PhJ dams had higher calcium concentrations than did milk collected from C57BL/6J dams. Despite this, cross-strain fostering had no effect on adult calcium preferences relative to mice of the same strain that were within-strain fostered or not fostered. Our results indicate that calcium avoidance by C57BL/6J mice and acceptance by PWK/PhJ mice are unaffected by maternal environment during the suckling period.

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

    PubMed

    Rawat, Kamla; Bohidar, H B

    2012-09-13

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

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

    PubMed

    Rawat, Kamla; Bohidar, H B

    2012-09-13

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

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

    PubMed

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

    2010-07-15

    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 degrees C, respectively. The apparent adsorption energy of Rh was about -7.6 kJ/mol and thus Rh(III) adsorption was a physical type. The experimental data obtained could be better simulated by pseudo-first-order kinetic model and the activation energy obtained was 6.54 J/mol. The adsorption rate of Rh(III) was controlled by intraparticle diffusion in most of time of adsorption process.

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

    PubMed

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

    2010-07-15

    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 degrees 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. PMID:20346581

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

    PubMed

    Lee, Jin-Young; Rajesh Kumar, J; Kim, Joon-Soo; Park, Hyung-Kyu; Yoon, Ho-Sung

    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(-1). However, at 10 mol L(-1) HCl concentration, the extraction behavior was reversed, indicating the solvation type mechanism during extraction. The quantitative extraction of approximately 98% platinum(IV) and 36% rhodium(III) was achieved with 0.01 mol L(-1) Alamine 308. The highest separation factor (S.F.=184.7) of platinum(IV) and rhodium(III) was achieved with 0.01 mol L(-1) Alamine 308 at 1.0 mol L(-1) of hydrochloric acid concentration. Alkaline metal salts like sodium chloride, sodium nitrate, sodium thiocyanate, lithium chloride, lithium nitrate, potassium chloride and potassium thiocyanate used for the salting-out effect. LiCl proved as best salt for the extraction of platinum(IV). Temperature effect demonstrates that the extraction process is exothermic. Hydrochloric acid and thiourea mixture proved to be better stripping reagents when compared with other mineral acids and bases. PMID:19285802

  13. Growth kinetics of calcium oxalate monohydrate. III. Variation of solution composition

    NASA Astrophysics Data System (ADS)

    Bijvoet, Olav L. M.; Blomen, Leo J. M. J.; Will, Eric J.; van der Linden, Hanneke

    1983-11-01

    The influence of the variations of initial supersaturation, ionic strength and calcium-to-oxalate ratio on the growth kinetics of calcium oxalate monohydrate from suspension at 37°C have been investigated in an isotopic system. All experiments can be described with a single growth formula, containing three constants: kA (growth rate constant), La (thermodynamic solubility product) and [ tm] (a parameter describing the agglomeration of any seed suspension). This formula is able to predict any growth curve when the initial concentrations of seed, oxalate and indifferent electrolyte are known. Comparisons with datak from the literature are discussed.

  14. An empirical equation with tables of smoothed solubilities of methane in water and aqueous sodium chloride solutions up to 25 weight percent, 360 degrees C, and 138 MPa

    USGS Publications Warehouse

    Haas, John L.

    1978-01-01

    The total pressure for the system H2O-CH 4 is given by p(total) = P(H2O,t) + exp10[log x(CH 4) - a - b x(CH4)], where P(H2O,t) is the vapor pressure of H2O liquid at the temperature t (?C) and x(CH 4) is the molal concentration of methane in the solution. The terms a and b are functions of temperature only. Where the total pressure and temperature are known, the concentration of methane, x(CH4), is found by iteration. The concentration of methane in a sodium chloride brine, y(CH4), is estimated using the function log y(CH4) = log x(CH4) - A I, where A is the salting out constant and I is the ionic strength. For sodium chloride solutions, the ionic strength is equal to the molality of the salt. The equations are valid to 360?C, 138 MPa, and 25 weight percent sodium chloride.

  15. Effects of solution chemistry on the removal reaction between calcium carbonate-based materials and Fe(II).

    PubMed

    Wang, Yu; Sikora, Saraya; Kim, Hwidong; Boyer, Treavor H; Bonzongo, Jean-Claude; Townsend, Timothy G

    2013-01-15

    Elevated iron concentrations have been observed in the groundwater underlying and surrounding several Florida landfill sites. An in situ groundwater remediation method for iron (present as soluble ferrous iron) using a permeable reactive barrier composed of calcium carbonate-based materials (CCBMs), such as limestone, was examined as a potentially effective and low-cost treatment technique. The effects of various environmental factors (i.e., pH, co-existing cations, and natural organic matter (NOM)) on the removal reaction were investigated using laboratory batch studies. Solution pH had a minor effect on iron removal, with superior iron removal observed in the highest pH solution (pH of 9). Sodium and calcium tended to impede the iron removal process by increasing the ionic strength of the solution. Manganese competes with iron ions at the adsorption sites on CCBMs; therefore, the presence of manganese prohibits iron removal and reduces removal effectiveness. NOM was found to decrease Fe(II) uptake by CCBMs and reduce the removal effectiveness by complexing Fe(II), most likely through the carboxyl group, thereby maintaining Fe(II) mobility in the aqueous phase.

  16. Effects of injecting calcium-buffer solution on [Ca2+]i in voltage-clamped snail neurons.

    PubMed Central

    Kennedy, H J; Thomas, R C

    1996-01-01

    We have investigated why fura-2 and Ca(2+)-sensitive microelectrodes report different values for the intracellular free calcium ion concentration ([Ca(2+)]i or its negative log, pCa(i)) of snail neurons voltage-clamped to -50 or -60 mV. Both techniques were initially calibrated in vitro, using calcium calibration solutions that had ionic concentrations similar to those of snail neuron cytoplasm. Pressure injections of the same solutions at resting and elevated [Ca(2+)]i were used to calibrate both methods in vivo. In fura-2-loaded cells these pressure injections generated changes in [Ca(2+)]i that agreed well with those expected from the in vitro calibration. Thus, using fura-2 calibrated in vitro, the average resting [Ca(2+)]i was found to be 38 nM (pCa(i) 7.42 +/- 0.05). With Ca(2+)-sensitive microelectrodes, the first injection of calibration solutions always caused a negative shift in the recorded microelectrode potential, as if the injection lowered [Ca2+]i. No such effects were seen on the fura-2 ratio. When calibrated in vivo the Ca(2+)-sensitive microelectrode gave an average resting [Ca2+]i of approximately 25 nM (pCa(i) 7.6 +/- 0.1), much lower than when calibrated in vitro. We conclude that [Ca(2+)]i in snail neurons is approximately 40 nM and that Ca(2+)-sensitive microelectrodes usually cause a leak at the point of insertion. The effects of the leak were minimized by injection of a mobile calcium buffer. PMID:9172736

  17. Adrenomedullin increased the short-circuit current in the pig oviduct through chloride channels via the CGRP receptor: mediation by cAMP and calcium ions but not by nitric oxide.

    PubMed

    Liao, S B; Cheung, K H; Cheung, M P L; To, Y T; O, W S; Tang, F

    2013-10-01

    The oviduct serves as a site for the fertilization of the ovum and the transport of the conceptus down to the uterus for implantation. In this study, we investigated the presence of adrenomedullin (ADM) and its receptor component proteins in the pig oviduct. The effect of ADM on oviductal secretion, the specific receptor, and the mechanisms involved were also investigated. The presence of ADM and its receptor component proteins in the pig oviduct were confirmed using immunostaining. Short-circuit current (I(sc)) technique was employed to study chloride ion secretion in the oviductal epithelium. ADM increased I(sc) through cAMP- and calcium-activated chloride channels, and this effect could be inhibited by the CGRP receptor antagonist, hCGRP8-37. In contrast, the nitric oxide synthase inhibitor, L-NG-nitroarginine methyl ester (L-NAME), could not block the effect of ADM on I(sc). In summary, ADM may increase oviductal fluid secretion via chloride secretion independent of the nitric oxide pathway for the transport of sperm and the conceptus.

  18. Synthesis of nesquehonite by reaction of gaseous CO2 with Mg chloride solution: its potential role in the sequestration of carbon dioxide.

    PubMed

    Ferrini, Vincenzo; De Vito, Caterina; Mignardi, Silvano

    2009-09-15

    In this paper is reported a novel method to synthesize nesquehonite, MgCO(3) x 3H(2)O, via reaction of a flux of CO(2) with Mg chloride solution at 20+/-2 degrees C. The reaction rate is rapid, with carbonate deposition almost complete in about 10 min. The full characterization of the product of synthesis has been performed to investigate its potential role as a "CO(2)-sequestering medium" and a means of disposing Mg-rich wastewater. We investigated the nesquehonite synthesized using SEM, XRD, FTIR and thermal analysis. The thermodynamic and chemical stability of this low-temperature hydrated carbonate of Mg and its possible transformation products make our method a promising complementary solution to other methods of CO(2) sequestration. Carbonation via magnesium chloride aqueous solutions at standard conditions represents a simple and permanent method of trapping CO(2). It could be applied at point sources of CO(2) emission and could involve rejected brine from desalination plants and other saline aqueous wastes (i.e., "produced water"). The likelihood of using the resulting nesquehonite and the by-products of the process in a large number of applications makes our method an even more attractive solution.

  19. Trypanosomes and the solution of a fifty years-mitochondrial calcium mystery

    PubMed Central

    Docampo, Roberto; Lukeš, Julius

    2011-01-01

    The ability of mitochondria to take up Ca2+ was discovered 50 years ago. This calcium uptake, through a mitochondrial calcium uniporter (MCU), is important not only for the regulation of cellular ATP concentration but also for more complex pathways such as shaping Ca2+ signals and activation of programmed cell death. The molecular nature of the uniporter remained unknown for decades. By a comparative study of mitochondrial protein profiles of organisms lacking or possessing MCU, such as yeast in the former case and vertebrates and trypanosomes in the latter, two groups recently found the protein that possesses all the characteristics of the MCU. These results add another success story to the already substantial contributions of trypanosomes to mammalian biochemistry. PMID:22088944

  20. Studies on endogenous circulating calcium entry blocker and stimulator

    SciTech Connect

    Pang, P.K.T.; Yang, M.C.M.

    1986-03-01

    Several synthetic compounds have been studied extensively for their calcium entry blockade and stimulation in smooth muscles. It is hypothesized that there should be endogenous substances which control calcium entry into cells. We recently investigated the effect of some vasoactive hormones on calcium entry. Our studies on rat tail artery helical strip showed that the in vitro vasoconstriction produced by arginine vasopressin (AVP) decreased stepwise with decreasing concentration of both calcium. After exposure of the tail artery to calcium-free Ringer's solution for 1 minute or longer, the tissue lost its ability to respond to AVP. Subsequent addition of calcium to the medium produced immediate contraction. Measurements of low affinity lanthanum resistant pool of calcium with /sup 45/Ca showed that AVP increased calcium uptake by tail artery in a dose-dependent manner. In another study rat tail artery helical strip indicated that the vasorelaxing action of parathyroid hormone (PTH) was related to an inhibition of calcium uptake. AVP or 60 mM potassium chloride increased the low affinity lanthanum resistant pool of calcium in rate tail artery and PTH inhibited the increase. In conclusion, AVP and PTH may behave like endogenous calcium entry stimulator and inhibitor respectively in vascular tissues.