determination of serum chloride ion concentration in pregnant

African Journals Online (AJOL)

Yusif

ABSTRACT. Serum chloride ion level in blood samples of pregnant women attending ante-natal care clinic in Minjibir was investigated. The mean and standard deviation of the ion in the samples is 100.51+ 4.89mmol/L. The distribution is skewed towards high frequency of low concentrations and could be attributed to.

Respective effects of sodium and chloride ion on physiological ...

African Journals Online (AJOL)

Respective effects of sodium and chloride ion on growth, cell morphological changes, membrane disorganization, ion homeostasis, exoenzyme activities and fermentation performance in Zymomonas mobilis232B cultures were presented. In batch cultures containing 0.15 M NaCl, Z. mobilis232B developed filaments, and ...

Detection of chloride ion concentration using chronopotentiometry

NARCIS (Netherlands)

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

2013-01-01

In this paper, a novel approach is reported for the electrochemical measurement of chloride ions using chronopotentiometry. A current pulse is applied at the Ag/AgCl working electrode and the potential change is measured with respect to another identical Ag/AgCl electrode in the bulk electrolyte.

Erratum to: Study on Chloride Ion Penetration Resistance of Rubberized Concrete Under Steady State Condition

Directory of Open Access Journals (Sweden)

Md Noor Nurazuwa

2016-01-01

In this paper, the effect of crumb rubber, CR as fine aggregate in the concrete to enhance concrete durability against chloride ion diffusion was studied. Chloride ion diffusion in rubberized concrete was tested by migration test under steady state condition. Concrete specimen with water-to-cement ratio of 0.50 was prepared to study the CR effectiveness in comparison with lower water-to-cement ratio. In addition, 10% silica fume, SF was added to provide denser concrete and to understand its effectiveness against chloride ion diffusion. Results showed that chloride transport characteristics were improved by the increasing amount of CR in all mixed due to the fact that CR has the ability to repel water. Meanwhile, rubberized concrete with w/c = 0.35 gave better resistance against chloride ion penetration compared to w/c = 0.50. This was much improved with combination of CR and SF.

Sulfate radical-based degradation of polychlorinated biphenyls: Effects of chloride ion and reaction kinetics

Energy Technology Data Exchange (ETDEWEB)

Fang, Guo-Dong [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Dionysiou, Dionysios D. [Environmental Engineering and Science Program, University of Cincinnati, Cincinnati, OH 45221-0071 (United States); Wang, Yu [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Al-Abed, Souhail R. [National Risk Management Research Laboratory, U.S. Environmental Protection Agency, 26 West Martin Luther King Drive, Cincinnati, OH 45268 (United States); Zhou, Dong-Mei, E-mail: dmzhou@issas.ac.cn [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China)

2012-08-15

Highlights: Black-Right-Pointing-Pointer A kinetic model was used to predict the radical species and their distributions. Black-Right-Pointing-Pointer The generated radical species were identified by EPR. Black-Right-Pointing-Pointer The second-order rate constants of sulfate radical with PCBs were determined. - Abstract: Advanced oxidation processes (AOPs) based on sulfate radical (SO{sub 4}{center_dot}{sup -}) have been recently used for soil and groundwater remediation. The presence of chloride ion in natural or wastewater decreases the reactivity of sulfate radical system, but explanations for this behavior were inconsistent, and the mechanisms are poorly understood. Therefore, in this paper we investigated the effect of chloride ion on the degradation of 2,4,4 Prime -CB (PCB28) and biphenyl (BP) by persulfate, based on the produced SO{sub 4}{center_dot}{sup -}. The results showed that the presence of chloride ion greatly inhibited the transformation of PCB28 and BP. Transformation intermediates of BP were monitored, suggesting that the chloride ion can react with SO{sub 4}{center_dot}{sup -} to produce chlorine radical, which reacts with BP to generate chlorinated compounds. To better understand the underlying mechanisms of these processes, a kinetic model was developed for predicting the effect of chloride ion on the types of radical species and their distributions. The results showed that chloride ion could influence the selectivity of radical species and their distribution, and increase the concentration of the sum of radical species. In addition, the second-order rate constants of sulfate radical with PCBs were determined, and quantum-chemical descriptors were introduced to predict the rate constants of other PCBs based on our experimental data.

Angiotensin-I converting enzyme (ACE): structure, biological roles, and molecular basis for chloride ion dependence.

Science.gov (United States)

Masuyer, Geoffrey; Yates, Christopher J; Sturrock, Edward D; Acharya, K Ravi

2014-10-01

Somatic angiotensin-I converting enzyme (sACE) has an essential role in the regulation of blood pressure and electrolyte fluid homeostasis. It is a zinc protease that cleaves angiotensin-I (AngI), bradykinin, and a broad range of other signalling peptides. The enzyme activity is provided by two homologous domains (N- and C-), which display clear differences in substrate specificities and chloride activation. The presence of chloride ions in sACE and its unusual role in activity was identified early on in the characterisation of the enzyme. The molecular mechanisms of chloride activation have been investigated thoroughly through mutagenesis studies and shown to be substrate-dependent. Recent results from X-ray crystallography structural analysis have provided the basis for the intricate interactions between ACE, its substrate and chloride ions. Here we describe the role of chloride ions in human ACE and its physiological consequences. Insights into the chloride activation of the N- and C-domains could impact the design of improved domain-specific ACE inhibitors.

Kinetics and thermodynamics of aluminium dissolution in 1.0M sulphuric acid containing chloride ions

Energy Technology Data Exchange (ETDEWEB)

Abdel-Gaber, A.M. [Department of Chemistry, Faculty of Science, Alexandria University, P.O. Box 426, Ibrahimia, Alexandria 21321 (Egypt)]. E-mail: ashrafmoustafa@yahoo.com; Abd-El-Nabey, B.A. [Department of Chemistry, Faculty of Science, Alexandria University, P.O. Box 426, Ibrahimia, Alexandria 21321 (Egypt); Sidahmed, I.M. [Department of Chemistry, Faculty of Science, Alexandria University, P.O. Box 426, Ibrahimia, Alexandria 21321 (Egypt); El-Zayady, A.M. [Department of Chemistry, Faculty of Science, Alexandria University, P.O. Box 426, Ibrahimia, Alexandria 21321 (Egypt); Saadawy, M. [Department of Chemistry, Faculty of Science, Alexandria University, P.O. Box 426, Ibrahimia, Alexandria 21321 (Egypt)

2006-08-01

The dissolution of aluminium in 1M sulphuric acid solutions containing different chloride ion concentrations (0.01-0.06M) were studied at 25, 30, 35 and 40deg. C using electrochemical impedance spectroscopy (EIS) technique and polarization curves measurements. The kinetic rate equation, under the experimental condition described, was derived and found to verify the following relationship:V=k{sub obs}K{sub 2}C{sub Cl{sup -}}{sup n}1+K{sub 2}C{sub Cl{sup -}}{sup n}where V is the corrosion rate, k{sub obs} and K{sub 2} are the dissolution rate constant of aluminium oxide-chloride complex and the equilibrium constant of chloride ions adsorbed at aluminium oxide surface, respectively. The kinetic and thermodynamic energy parameters were calculated and their values indicate that chloride ions are chemisorbed onto the aluminium oxide surface and the formation of oxide-chloride complex is the rate-determining step.

A synthetic ion transporter that disrupts autophagy and induces apoptosis by perturbing cellular chloride concentrations

Science.gov (United States)

Busschaert, Nathalie; Park, Seong-Hyun; Baek, Kyung-Hwa; Choi, Yoon Pyo; Park, Jinhong; Howe, Ethan N. W.; Hiscock, Jennifer R.; Karagiannidis, Louise E.; Marques, Igor; Félix, Vítor; Namkung, Wan; Sessler, Jonathan L.; Gale, Philip A.; Shin, Injae

2017-07-01

Perturbations in cellular chloride concentrations can affect cellular pH and autophagy and lead to the onset of apoptosis. With this in mind, synthetic ion transporters have been used to disturb cellular ion homeostasis and thereby induce cell death; however, it is not clear whether synthetic ion transporters can also be used to disrupt autophagy. Here, we show that squaramide-based ion transporters enhance the transport of chloride anions in liposomal models and promote sodium chloride influx into the cytosol. Liposomal and cellular transport activity of the squaramides is shown to correlate with cell death activity, which is attributed to caspase-dependent apoptosis. One ion transporter was also shown to cause additional changes in lysosomal pH, which leads to impairment of lysosomal enzyme activity and disruption of autophagic processes. This disruption is independent of the initiation of apoptosis by the ion transporter. This study provides the first experimental evidence that synthetic ion transporters can disrupt both autophagy and induce apoptosis.

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

Science.gov (United States)

Tang, Jaw-Luen; Wang, Jian-Neng

2007-06-01

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

Influence of Chloride Ion and Temperature on the Corrosion Behavior of Ni-Fe-Cr Alloy 028

Science.gov (United States)

Zhang, L. N.; Dong, J. X.; Szpunar, J. A.; Zhang, M. C.; Basu, R.

Recently, the working condition of tubing systems used in oil and natural gas industries are severer than before with the increasing exploitation of acidic gas fields. The corrosion problems induced from the corrosive environment with chloride ion medium and high temperature have been much more concerned. The presence of chloride ion can accelerate the dissolution of metals. The corrosion performance is also sensitive to the operating temperature. Classic localized corrosions such as the pitting or the crevice type due to environmental temperature and chloride ion.

Sensor-actuator system for dynamic chloride ion determination.

Science.gov (United States)

de Graaf, Derk Balthazar; Abbas, Yawar; Gerrit Bomer, Johan; Olthuis, Wouter; van den Berg, Albert

2015-08-12

Chloride is a crucial anion for various analytical applications from biological to environmental applications. In order to measure the chloride ion concentration, a measurement system is needed which can detect this concentration for prolonged times reliably. Chronopotentiometry is a technique which does not need a long term stable reference electrode and is therefore very suitable for prolonged ion concentration measurements. As the used electrode might be fouled by reaction products, this work focuses on a chronopotentiometric approach with a separated sensing electrode (sensor) and actuating electrode (actuator). Both actuation and sensor electrode are made of Ag/AgCl. A constant current is applied to the actuator and will start the reaction between Ag and Cl-, while the resulting Cl- ion concentration change is observed through the sensor, which is placed close to the actuator. The time it takes to locally deplete the Cl- ions is called transition time. Experiments were performed to verify the feasibility of this approach. The performed experiments show that the sensor detects the local concentration changes resulting from the current applied to the actuator. A linear relation between the Cl- ion concentration and the square root of the transition time was observed, just as was predicted by theory. The calibration curves for different chips showed that both a larger sensor and a larger distance between sensor and actuator resulted in a larger time delay between the transition time detected at the actuator and the sensor. Copyright © 2015 Elsevier B.V. All rights reserved.

Changes in acceleration rate of chloride ions depending on climatic conditions. Influence of rain

International Nuclear Information System (INIS)

Corvo, F.; Arroyave, C.; Autie, M.; Minotas, J.; Balmaseda, J.; Delgado, J.; Haces, C.

2003-01-01

Mild steel,copper and aluminum samples were exposed outdoors in two atmospheric test stations located in Havana, Cuba and Medellin, colombia. Two parallel group of samples were formed, one for each station. They were submitted to accelerated outdoor test by intermittent spraying of a salt solution (SCAB test) according to ISO 11474.98, receiving also the influence of the open atmosphere. The acceleration of corrosion rate of the three metals caused by the presence of chloride ions in both stations was determined. As expected, steel shows the higher corrosion rate and acceleration by chlorides, particularly at Cuban corrosion station. A remarkable difference in the acceleration rate of chloride ions for mild steel and copper between Cuban and Colombian acceleration rate of chloride ions of steel and copper. Steel corrosion products were analysed by Moessbauer Spectroscopy. Water absorption was also studied. The presence of magnetite, goethite and other Iron compounds was determined. (Author) 10 refs

A Microfluidic Long-Period Fiber Grating Sensor Platform for Chloride Ion Concentration Measurement

Directory of Open Access Journals (Sweden)

Jian-Neng Wang

2011-09-01

Full Text Available Optical fiber sensors based on waveguide technology are promising and attractive in chemical, biotechnological, agronomy, and civil engineering applications. A microfluidic system equipped with a long-period fiber grating (LPFG capable of measuring chloride ion concentrations of several sample materials is presented. The LPFG-based microfluidic platform was shown to be effective in sensing very small quantities of samples and its transmitted light signal could easily be used as a measurand. The investigated sample materials included reverse osmosis (RO water, tap water, dilute aqueous sample of sea sand soaked in RO water, aqueous sample of sea sand soaked in RO water, dilute seawater, and seawater. By employing additionally a chloride ion-selective electrode sensor for the calibration of chloride-ion concentration, a useful correlation (R2 = 0.975 was found between the separately-measured chloride concentration and the light intensity transmitted through the LPFG at a wavelength of 1,550 nm. Experimental results show that the sensitivity of the LPFG sensor by light intensity interrogation was determined to be 5.0 × 10−6 mW/mg/L for chloride ion concentrations below 2,400 mg/L. The results obtained from the analysis of data variations in time-series measurements for all sample materials show that standard deviations of output power were relatively small and found in the range of 7.413 × 10−5–2.769 × 10−3 mW. In addition, a fairly small coefficients of variations were also obtained, which were in the range of 0.03%–1.29% and decreased with the decrease of chloride ion concentrations of sample materials. Moreover, the analysis of stability performance of the LPFG sensor indicated that the random walk coefficient decreased with the increase of the chloride ion concentration, illustrating that measurement stability using the microfluidic platform was capable of measuring transmitted optical power with accuracy in the range of −0

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

Institute of Scientific and Technical Information of China (English)

WANG Zixiao; YU Lei; LIU Zhiyong; SONG Ning

2015-01-01

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

Low-cost and reagent-free paper-based device to detect chloride ions in serum and sweat.

Science.gov (United States)

Cinti, Stefano; Fiore, Luca; Massoud, Renato; Cortese, Claudio; Moscone, Danila; Palleschi, Giuseppe; Arduini, Fabiana

2018-03-01

The recent goal of sustainability in analytical chemistry has boosted the development of eco-designed analytical tools to deliver fast and cost-effective analysis with low economic and environmental impact. Due to the recent focus in sustainability, we report the use of low-cost filter paper as a sustainable material to print silver electrodes and to load reagents for a reagent-free electrochemical detection of chloride in biological samples, namely serum and sweat. The electrochemical detection of chloride ions was carried out by exploiting the reaction of the analyte (i.e. chloride) with the silver working electrode. During the oxidation wave in cyclic voltammetry the silver ions are produced, thus they react with chloride ions to form AgCl, while in the reduction wave, the following reaction occurs: AgCl + e - -->Ag + Cl - . These reactions at the electrode surface resulted in anodic/cathodic peaks directly proportional to the chloride ions in solution. Chloride ions were detected with the addition of only 10μL of the sample on the paper-based electrochemical cell, obtaining linearity up to 200mM with a detection limit equal to 1mM and relative standard deviation lower than 10%. The accuracy of the sensor was evaluated in serum and sweat samples, with percentage recoveries between 93 ± 10 and 108 ± 8%. Moreover, the results achieved with the paper-based device were positively compared with those obtained by using the gold standard method (Ion Selective Electrode) adopted in routine clinical analyses. Copyright © 2017 Elsevier B.V. All rights reserved.

A Novel Passive Wireless Sensing Method for Concrete Chloride Ion Concentration Monitoring

Directory of Open Access Journals (Sweden)

Shuangxi Zhou

2017-12-01

Full Text Available In this paper, a novel approach for concrete chloride ion concentration measuring based on passive and wireless sensor tag is proposed. The chloride ion sensor based on RFID communication protocol is consisting of an energy harvesting and management circuit, a low dropout voltage regulator, a MCU, a RFID tag chip and a pair of electrodes. The proposed sensor harvests energy radiated by the RFID reader to power its circuitry. To improve the stability of power supply, a three-stage boost rectifier is customized to rectify the harvested power into dc power and step-up the voltage. Since the measured data is wirelessly transmitted, it contains miscellaneous noises which would decrease the accuracy of measuring. Thus, in this paper, the wavelet denoising method is adopted to denoise the raw data. Besides, a monitoring software is developed to display the measurement results in real-time. The measurement results indicate that the proposed passive sensor tag can achieve a reliable communication distance of 16.3 m and can reliably measure the chloride ion concentration in concrete.

A Novel Passive Wireless Sensing Method for Concrete Chloride Ion Concentration Monitoring.

Science.gov (United States)

Zhou, Shuangxi; Sheng, Wei; Deng, Fangming; Wu, Xiang; Fu, Zhihui

2017-12-11

In this paper, a novel approach for concrete chloride ion concentration measuring based on passive and wireless sensor tag is proposed. The chloride ion sensor based on RFID communication protocol is consisting of an energy harvesting and management circuit, a low dropout voltage regulator, a MCU, a RFID tag chip and a pair of electrodes. The proposed sensor harvests energy radiated by the RFID reader to power its circuitry. To improve the stability of power supply, a three-stage boost rectifier is customized to rectify the harvested power into dc power and step-up the voltage. Since the measured data is wirelessly transmitted, it contains miscellaneous noises which would decrease the accuracy of measuring. Thus, in this paper, the wavelet denoising method is adopted to denoise the raw data. Besides, a monitoring software is developed to display the measurement results in real-time. The measurement results indicate that the proposed passive sensor tag can achieve a reliable communication distance of 16.3 m and can reliably measure the chloride ion concentration in concrete.

Reactions of enolisable ketones with dichloroisocyanuric acid in absence and presence of added chloride ions – a kinetic study

Directory of Open Access Journals (Sweden)

Y. L. Kumar

2015-01-01

Full Text Available Kinetics of reactions of enolisable ketones (S = acetone/2-butanone with dichloroisocyanuric acid (DCICA were studied in aqueous acetic acid and perchloric acid media in absence and presence of added chloride ions. The reactions were found to be pseudo zero order and pseudo first order on [DCICA] in absence and presence of chloride ions respectively. Both in presence and absence of chloride ions, first order and fractional order in substrate and perchloric acid were observed respectively. An increase in the rate of reaction was observed with an increase in chloride ion concentration as well as acetic acid composition. The results were interpreted in terms of probable mechanisms involving (i rate-determining enol formation from the conjugate acid of the ketone (SH+ in the absence of added chloride ions and (ii rate-determining interaction of SH+ with the most effective molecular chlorine species produced by the hydrolysis of DCICA (rather than a rate-determining interaction of enol with chlorine in the presence of added chloride ions, prior to the rapid steps of product formation. DOI: http://dx.doi.org/10.4314/bcse.v29i1.12

Stability constants of the Europium complexes with the chloride ions; Constantes de estabilidad de los complejos del europio con los iones cloruro

Energy Technology Data Exchange (ETDEWEB)

Jimenez R, M.; Solache R, M.; Rojas H, A. [Instituto Nacional de Investigaciones Nucleares, Departamento de Quimica, A.P. 18-1027, C.P. 11801 Mexico D.F. (Mexico)

2000-07-01

The stability constants of lanthanides complexes with chloride ions which were determined at the same ionic force but in different media, are significantly different. It does not exist a systematic study over these stability constants. The purpose of this work is to determine the stability constants of the europium complexes with chloride ions at 303 K, by the solvents extraction method. (Author)

Chloride (Cl−) ion-mediated shape control of palladium nanoparticles

International Nuclear Information System (INIS)

Nalajala, Naresh; Chakraborty, Arup; Bera, Bapi; Neergat, Manoj

2016-01-01

The shape control of Pd nanoparticles is investigated using chloride (Cl − ) ions as capping agents in an aqueous medium in the temperature range of 60–100 °C. With weakly adsorbing and strongly etching Cl − ions, oxygen plays a crucial role in shape control. The experimental factors considered are the concentration of the capping agents, reaction time and reaction atmosphere. Thus, Pd nanoparticles of various shapes with high selectivity can be synthesized. Moreover, the removal of Cl − ions from the nanoparticle surface is easier than that of Br − ions (moderately adsorbing and etching) and I − ions (strongly adsorbing and weakly etching). The cleaned Cl − ion-mediated shape-controlled Pd nanoparticles are electrochemically characterized and the order of the half-wave potential of the oxygen reduction reaction in oxygen-saturated 0.1 M HClO 4 solution is of the same order as that observed with single-crystal Pd surfaces. (paper)

Chloride ion addition for controlling shapes and properties of silver nanorods capped by polyvinyl alcohol synthesized using polyol method

Energy Technology Data Exchange (ETDEWEB)

Junaidi, E-mail: junaidi.1982@fmipa.unila.ac.id [Department of Physics, Universitas Gadjah Mada, Yogyakarta, 55281 (Indonesia); Department of Physics, Lampung University, Bandar Lampung (Indonesia); Yunus, Muhammad, E-mail: muhammad.yunus@mail.ugm.ac.id [Department of Physics, Universitas Gadjah Mada, Yogyakarta, 55281 (Indonesia); Triyana, Kuwat, E-mail: triyana@ugm.ac.id; Harsojo,, E-mail: harsojougm@ugm.ac.id; Suharyadi, Edi, E-mail: esuharyadi@ugm.ac.id [Department of Physics, Universitas Gadjah Mada, Yogyakarta, 55281 (Indonesia); Nanomaterials Research Group, Universitas Gadjah Mada, Yogyakarta, 55281 (Indonesia)

2016-04-19

We report our investigation on the effect of chloride ions on controlling the shapes and properties of silver nanorods (AgNRs) synthesized using a polyol method. In this study, we used polyvinyl alcohol (PVA) as a capping agent and sodium chloride (NaCl) as a salt precursor and performed at the oil bath temperature of 140°C. The chloride ions originating from the NaCl serve to control the growth of the silver nanorods. Furthermore, the synthesized silver nanorods were characterized using SEM and XRD. The results showed that besides being able to control the growth of AgCl atoms, the chloride ions were also able to control the growth of multi-twinned-particles into the single crystalline of silver nanorods by micrometer-length. At an appropriate concentration of NaCl, the diameter of silver nanorods decreased significantly compared to that of without chloride ion addition. This technique may be useful since a particular diameter of silver nanorods affects a particular application in the future.

Chloride ion addition for controlling shapes and properties of silver nanorods capped by polyvinyl alcohol synthesized by polyol method

International Nuclear Information System (INIS)

Junaidi; Triyana, Kuwat; Harsojo,; Suharyadi, Edi

2016-01-01

We report our investigation on the effect of chloride ions oncontrolling the shapes and properties of silver nanorods(AgNRs) synthesized using a polyol method. In this study, we used polyvinyl alcohol (PVA) as a capping agent and sodium chloride (NaCl) as asalt precursor and performed at the oilbath temperature of 140 °C. The chloride ions originating from the NaCl serve to control the growth of the silver nanorods. Furthermore, the synthesized silver nanorodswere characterized using UV-VIS, XRD, SEM and TEM. The results showed that besides being able to control the growth of AgCl atoms, the chloride ions were also able to control the growth of multi-twinned-particles into the single crystalline silver nanorods by micrometer-length. At an appropriate concentration of NaCl, the diameter of silver nanorodsdecreased significantly compared to that of without chloride ion addition. This technique may be useful since a particular diameter of silver nanorods affects a particular application in the future.

Chloride ion addition for controlling shapes and properties of silver nanorods capped by polyvinyl alcohol synthesized using polyol method

International Nuclear Information System (INIS)

Junaidi; Yunus, Muhammad; Triyana, Kuwat; Harsojo,; Suharyadi, Edi

2016-01-01

We report our investigation on the effect of chloride ions on controlling the shapes and properties of silver nanorods (AgNRs) synthesized using a polyol method. In this study, we used polyvinyl alcohol (PVA) as a capping agent and sodium chloride (NaCl) as a salt precursor and performed at the oil bath temperature of 140°C. The chloride ions originating from the NaCl serve to control the growth of the silver nanorods. Furthermore, the synthesized silver nanorods were characterized using SEM and XRD. The results showed that besides being able to control the growth of AgCl atoms, the chloride ions were also able to control the growth of multi-twinned-particles into the single crystalline of silver nanorods by micrometer-length. At an appropriate concentration of NaCl, the diameter of silver nanorods decreased significantly compared to that of without chloride ion addition. This technique may be useful since a particular diameter of silver nanorods affects a particular application in the future.

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

Energy Technology Data Exchange (ETDEWEB)

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

2009-04-14

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

Chloride ion-dependent surface-enhanced Raman scattering study of biotin on the silver surface

International Nuclear Information System (INIS)

Liu Fangfang; Gu Huaimin; Yuan Xiaojuan; Dong Xiao; Lin Yue

2011-01-01

In the present paper, the surface enhanced Raman scattering (SERS) technique was employed to study the SERS spectra of biotin molecules formed on the silver surface. The adsorption geometries of biotin molecules on the silver surface were analyzed based on the SERS data. It can be found that most vibration modes show a Raman shift in silver sol after the addition of sodium chloride solution. In addition, The Raman signals of biotin become weaker and weaker with the increase of the concentration of sodium chloride. This may be due to that the interaction between chloride ions and silver particles is stronger than the interaction between biotin molecules and silver particles. When the concentration of sodium chloride in silver colloid is higher than 0.05mol/L, superfluous chloride ions may form an absorption layer so that biotin can not be adsorbed on silver surface directly. The changes in intensity and profile shape in the SERS spectra suggest different adsorption behavior and surface-coverage of biotin on silver surface. The SERS spectra of biotin suggest that the contribution of the charge transfer mechanism to SERS may be dominant.

Effect and interactions of commercial additives and chloride ion in copper electrowinning

Science.gov (United States)

Cui, Wenyuan

This thesis is to understand and compare the effects and interactions of modified polysaccharide (HydroStar), polyacrylamide (Cyquest N-900) and chloride ion on copper electrowinning. A study of the nucleation and growth was conducted in a synthetic electrolyte (40 g/L Cu, 160 g/L H2SO 4, 20 mg/L Cl-) with the addition of HydroStar or Cyquest N-900 using potential step measurements. The current responses generated were compared to theoretical models of nucleation and growth mechanisms. The nucleation and growth mechanism changed as function of potential and the presence of organic additives. The nucleation and growth mechanisms were confirmed using scanning electron microscopy (SEM). At low overpotentials, electrodeposition from the electrolyte without additives proceeded by progressive nucleation with three-dimensional (3-D) growth. The addition of HydroStar produced smaller nuclei and changed the mechanism to progressive nucleation and 2-D growth. Cyquest N-900 used there appeared to be progressive nucleation with 2-D growth and polarize the cathodes. In addition, instantaneous nucleation under diffusion control occurred at high overpotentials. Chloride ion and its interaction with HydroStar and Cyquest N-900 were further characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The trends observed from Nyquist plots and equivalent circuit models were consistent with the CV results. Chloride, on its own, depolarized copper electrodeposition, while chloride ion associated with Cyquest N-900 inhibited the reaction. It is proposed that Cl- acted as a bridging ligand between copper and Cyquest N-900. The addition of HydroStar depolarized copper deposition, but it did not interact with.

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

Directory of Open Access Journals (Sweden)

Adnan Mohammed Shihab

2016-03-01

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

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

International Nuclear Information System (INIS)

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

1993-01-01

The anodic behaviour and passivity breakdown of alloy 800 in sodium bicarbonate and sodium phosphate aqueous solutions were studied in the temperature range from 100 degrees C to 280 degrees C by means of electrochemical techniques. The effect of phosphate or bicarbonate additions on the pitting susceptibility and pitting morphology of the alloy in chloride solutions was also examined. Experiments were performed in the following solutions: 0.1M NaHCO 3 , at 100 degrees C, 200 degrees C, 280 degrees C; 0.06M NaH 2 PO 4 + 0.04M Na 2 HPO 4 , at 100 degrees C, 200 degrees C and 280 degrees C, and 0.1M NaCl with different additions of bicarbonate ion (0.02M, 0.05M and 0.1M) and phosphate ion (0.01M, 0.05M and 0.1M) at 100 degrees C and 280 degrees C. The anodic polarization curves of alloy 800 in deaerated 0.1M NaHCO 3 and 0.06M NaH 2 PO 4 + 0.04M Na 2 HPO 4 solutions exhibited a similar shape at all the tested temperatures. No localized or generalized corrosion was detected on the metallic surface after polarization. The results obtained in chloride plus bicarbonate and chloride plus phosphate mixtures showed that the pitting potential of alloy 800 in chloride solutions was increased by the presence of bicarbonate or phosphate ions. In those solutions where the inhibitor concentration in the mixture is equal or higher than the chloride concentration , the behaviour of the alloy is similar to the one observed in the absence of chlorides. Changes in pitting morphology were found in phosphate containing solutions, while the pits found in bicarbonate containing solutions were similar to those formed in pure chloride solutions. (author). 3 refs., 4 figs

The effect and mechanism of chloride ion attack on portland cement ...

African Journals Online (AJOL)

At low concentrations, chloride ion has little or no effect on the physical stability of concrete structure but it causes the corrosion of the reinforcing steel in the concrete but at high concentration' especially at low temperature, it causes expansion and cracking in the concrete. The degradation is usually accompanied by ...

Studies on measurement of chloride ion concentration in concrete structures with long-period grating sensors

Science.gov (United States)

Tang, Jaw-Luen; Chiang, Tsung-Yu; Chang, Hsiang-Ping; Wang, Jian-Neng

2006-03-01

We report the development and demonstration of a simple and low-cost long-period grating (LPG) sensor for chloride ion concentration measurement in concrete structures. The LPG sensor is extremely sensitive to the refractive index of the medium surrounding the cladding surface of the sensing grating, thus allowing it to be used as an ambient index sensor or chemical concentration indicator with high stability and reliability. We have measured chloride ion levels in a concrete sample immersed in salt water solution with different weight concentration ranging from 0 % to 20 %, and results showed that the LPG sensor exhibited a linear decrease in the transmission loss and resonance wavelength shift when the concentration increased. The measurement accuracy for concentration of salt in water solution is estimated to be 0.6 % and the limit of detection for chloride ion is about 0.04 %. To further enhance its sensitivity for chloride concentrations, we have coated gold nanoparticles on the grating surface of the LPG sensor. The sensing mechanism is based on the sensitivity of localized surface plasmon resonance of self-assembled Au colloids on the grating portion of the LPG. With this method, a factor of two increases in sensitivity of detecting chemical solution concentrations was obtained. The advantage of this type of the sensor is relatively simple of construction and ease of use. Moreover, the sensor has the potential capability for on-site, in vivo, and remote sensing, and has the potential use for disposable sensors.

Characterization and application of automated in-vacuum PIXE/EBS system for direct analysis of chloride and sulfate ions attack in cementitious materials

Science.gov (United States)

Rihawy, M. S.; Alwazzeh, M.; Abbas, K.

2018-01-01

Ion beam analysis (IBA) techniques (Particle Induced X-ray Emission, PIXE and Elastic Backscattering Spectrometry, EBS), were applied to investigate chloride and sulfate ions diffusion into laboratory prepared mortar samples. Development and characterization of an automated in-vacuum macro PIXE/EBS system is thoroughly discussed. Depth profile information of both chloride and sulfate ions in laboratory prepared mortar samples, after immersion in sea water for nine months, was rapidly and easily obtained at fairly low cost and with standardless analysis, demonstrating the value of the application of IBA to elemental depth profiling in cementitious materials. Chloride and sulfate depth profiles were obtained for two sets of mortar samples, one prepared with different water/cement (W/C) ratios and the other with different sand/cement (S/C) ratios. Results showed higher diffusion rates of both chloride and sulfate ions when both ratios are increased. Additionally, the W/C ratio has a stronger influence in both sulfate and chloride penetration than the S/C ratio, and chloride ions penetrate faster than sulfates. Advantages and limitations of applying IBA techniques in this investigation are discussed. The comparison between PIXE and other X-ray based analytical techniques, namely X-ray fluorescence (XRF) and energy and wavelength dispersive X-rays (EDX/WDX), as well as other traditional wet chemical methods is reviewed, and industrial applications are discussed.

Chloride ions in the pore of glycine and GABA channels shape the time course and voltage dependence of agonist currents

Science.gov (United States)

Moroni, Mirko; Biro, Istvan; Giugliano, Michele; Vijayan, Ranjit; Biggin, Philip C.; Beato, Marco; Sivilotti, Lucia G.

2011-01-01

In the vertebrate CNS, fast synaptic inhibition is mediated by GABA and glycine receptors. We recently reported that the time course of these synaptic currents is slower when intracellular chloride is high. Here we extend these findings to measure the effects of both extracellular and intracellular chloride on the deactivation of glycine and GABA currents at both negative and positive holding potentials. Currents were elicited by fast agonist application to outside-out patches from HEK293 cells expressing rat glycine or GABA receptors. The slowing effect of high extracellular chloride on current decay was detectable only in low intracellular chloride (4 mM). Our main finding is that glycine and GABA receptors “sense” chloride concentrations because of interactions between the M2 pore-lining domain and the permeating ions. This hypothesis is supported by the observation that the sensitivity of channel gating to intracellular chloride is abolished if the channel is engineered to become cation-selective, or if positive charges in the external pore vestibule are eliminated by mutagenesis. The appropriate interaction between permeating ions and channel pore is also necessary to maintain the channel voltage sensitivity of gating, which prolongs current decay at depolarized potentials. Voltage-dependence is abolished by the same mutations that suppress the effect of intracellular chloride and also by replacing chloride with another permeant ion, thiocyanate. These observations suggest that permeant chloride affects gating by a foot-in-the-door effect, binding to a channel site with asymmetrical access from the intracellular and extracellular sides of the membrane. PMID:21976494

Changes in acceleration rate of chloride ions depending on climatic conditions. Influence of rain

Directory of Open Access Journals (Sweden)

Corvo, F.

2003-12-01

Full Text Available Mild steel, copper and aluminium samples were exposed outdoors in two atmospheric test stations located in Havana, Cuba and Medellín, Colombia. Two parallel group of samples were formed, one for each station. They were submitted to accelerated outdoor test by intermittent spraying of a salt solution (SCAB test according to ISO 11474:98, receiving also the influence of the open atmosphere. The acceleration of corrosion rate of the three metals caused by the presence of chloride ions in both stations was determined. As expected, steel shows the higher corrosion rate and acceleration by chlorides, particularly at Cuban corrosion station. A remarkable difference in the acceleration rate of chloride ions for mild steel and copper between Cuban and Colombian acceleration rate of chloride ions of steel and copper. Steel corrosion products were analyzed by Mössbauer Spectroscopy. Water absorption was also studied. The presence of magnetite, goethite and other Iron compounds was determined.

Probetas de acero de bajo carbono, cobre y aluminio se expusieron a la intemperie en dos estaciones de ensayo localizadas en la Habana, Cuba y Medellín, Colombia. Se formaron dos grupos paralelos de probetas, tomándose uno para cada estación. Ambos grupos fueron sometidos a ensayos acelerados a la intemperie mediante la aplicación de una niebla salina (SCAB TEST de acuerdo a la Norma ISO 11474:98, recibiendo también la influencia de la atmósfera abierta. Se determinó la aceleración de la velocidad de corrosión de los tres metales causada por la presencia de iones cloruro en ambas estaciones. Como era de esperar, el acero muestra la mayor velocidad de corrosión y aceleración por los iones cloruro, particularmente en la estación de ensayos cubana. Se determinó una notable diferencia en la velocidad de aceleración provocada por los cloruros para el acero de bajo carbono y el cobre entre las estaciones cubana y colombiana. La influencia de la lluvia

Sorption of sulphur dioxide in calcium chloride and nitrate chloride liquids

International Nuclear Information System (INIS)

Trzepierczynska, I.; Gostomczyk, M.A.

1989-01-01

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

Transition-metal chlorides as conversion cathode materials for Li-ion batteries

International Nuclear Information System (INIS)

Li Ting; Chen, Zhong X.; Cao, Yu L.; Ai, Xin P.; Yang, Han X.

2012-01-01

Insoluble AgCl and soluble CuCl 2 were selected and investigated as model compounds of transition-metal chlorides for electrochemical conversion cathode materials. The experimental results demonstrated that the AgCl nanocrystals can convert reversibly to metallic Ag with nearly full utilization of its one-electron redox capacity (187 mAh g −1 ). Similarly, the CuCl 2 -filled mesoporous carbon can realize a reversible two-electron transfer reaction, giving a very high reversible capacity of 466 mAh g −1 after 20 cycles. These data imply that the metal chlorides can undergo complete electrochemical conversion utilizing their full oxidation states for electrical energy storage as previously reported metal fluorides, possibly being used as high capacity cathode materials for Li-ion batteries.

An Accelerated Test Method of Simultaneous Carbonation and Chloride Ion Ingress: Durability of Silica Fume Concrete in Severe Environments

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S. A. Ghahari

2016-01-01

Full Text Available The effects of simultaneous carbonation and chloride ion attack on mechanical characteristics and durability of concrete containing silica fume have been investigated through an accelerated test method. Specimens containing different amounts of silica fume were maintained in an apparatus in which carbon dioxide pressure and concentration and relative humidity were kept constant, and wetting and drying cycles in saline water were applied. Surface resistivity, sorptivity, CO2 consumption, and carbonation and chloride ion ingress depths measurements were taken. Phase change due to carbonation and chloride ion attack was monitored by XRD analysis, and microstructures and interfacial transition zones were studied by implementing SEM as well as mercury intrusion porosimetry. It was expected to have a synergistic effect in the tidal zone where simultaneous carbonation and chloride ion attack happen. However, the observed reduced surface resistivity, compared to specimens maintained in CO2 gas, could be due to the moisture that is available near the surface, hindering CO2 from penetrating into the pores of the specimens. Moreover, the porosity analysis of the specimens showed that the sample containing silica fume cured in the tidal zone had 50.1% less total porosity than the plain cement paste cured in the same condition.

Kinetics of chloride ion adsorption on stainless alloys by in situ contact electric resistance technique

International Nuclear Information System (INIS)

Marichev, V.A.

2008-01-01

As the primary reason for pitting of stainless alloys, chloride adsorption is not adequately studied, e.g. kinetic investigations of chloride adsorption are actually absent. We discuss and partly reconsider some well-known facts (e.g. halides order: Cl - > Br - > I - ), disputed points (chloride penetration in passive film), and still unknown aspects of chloride adsorption. For the first time, we report kinetic studies of chloride adsorption on stainless alloys by in situ contact electric resistance technique. The peak-like character of kinetic curves has been found for all studied stainless alloys, but not for pure iron and nickel. This has been considered as a sequence of the substantial charge transfer during chloride adsorption. Opposite to typical d metals, stainless materials are alloys of early and late transition metals having unfilled d-bands with increased number of d-electron vacancies. Such electronic structure is favorable for adsorption of electron donating adsorbates like halide ions. Experimental data of this work are more compatible with possibility of chloride penetration into the passive films on stainless alloys that also might involve a transformation of primary oxy-hydroxide films into oxy-chloride films

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

International Nuclear Information System (INIS)

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

2010-01-01

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

Ferric chloride-graphite intercalation compounds as anode materials for Li-ion batteries.

Science.gov (United States)

Wang, Lili; Zhu, Yongchun; Guo, Cong; Zhu, Xiaobo; Liang, Jianwen; Qian, Yitai

2014-01-01

Ferric chloride-graphite intercalation compounds (FeCl3 -GICs) with stage 1 and stage 2 structures were synthesized by reacting FeCl3 and expanded graphite (EG) in air in a stainless-steel autoclave. As rechargeable Li-ion batteries, these FeCl3 -GICs exhibit high capacity, excellent cycling stability, and superior rate capability, which could be attributed to their unique intercalation features. This work may enable new possibilities for the fabrication of Li-ion batteries. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Determination of the stability constants of lanthanum, praseodymium, europium, erbium and lutetium complexes with chloride ions; Determinacion de las constantes de estabilidad de los complejos de lantano, praseodimio, europio, erbio y lutecio con iones cloruro

Energy Technology Data Exchange (ETDEWEB)

Fernandez R, E [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

2008-07-01

The stability constants of La{sup 3+}, Pr{sup 3+}, Eu{sup 3+}, Er{sup 3+} and Lu{sup 3+} chloride complexes were determined in perchloric acid media using a liquid-liquid extraction method. The dinonyl napthalene sulfonic acid in n-heptane was used as extractant. The lanthanide (Ln) concentrations were measured by a radiochemical (Eu and Lu) and a spectrophotometric (La, Pr, and Er) methods. In the last method, xylenol orange was used for the determinations at ph 6. The stability constants of lanthanum, praseodymium, erbium and lutetium chloride complexes were determined in 2, 3 and 4 M ionic strength and europium in 1, 2 and 3 M, at 303 K. The fitting of experimental data to the equations for the calculation of the stability constants, was carry out considering both one chemical species (LnCl{sup 2+}) or two chemical species (LnCl{sup 2+} and LnCl{sub 2}{sup +}). The Specific Ion Interaction Theory was applied to the values of log {beta}{sup I}{sub Ln},{sub Cl} and the first stability constants at zero ionic strength were calculated by extrapolation. The same theory could not be applied to the log {beta}{sup I}{sub Ln},{sub 2Cl}, due to its low abundance and the values determined for the stability constants were similar. The distribution diagrams of the chemical species were obtained using the program MEDUSA and considering log {beta}{sup I}{sub Ln},{sub CI}, log {beta}{sup I}{sub Ln},{sub 2CI} values obtained in this work and the hydrolysis constants taken from the literature. The lanthanide chloride complexes are present in solution at specific conditions of ionic strength, concentration and in the absence of hydrolysis. The log {beta}{sup I}{sub Ln},{sub Cl} data were related to the charge density and the corresponding equations were obtained. These equations could be used to determine the stability constants along the lanthanide series. (Author)

Synergistic inhibition between o-phenanthroline and chloride ion for steel corrosion in sulphuric acid

International Nuclear Information System (INIS)

Li Xueming; Tang Libin; Li Lin; Mu Guannan; Liu Guangheng

2006-01-01

The corrosion inhibition of cold rolled steel in 0.5 M sulphuric acid in the presence of o-phenanthroline and sodium chloride (NaCl) has been investigated by using weight loss and electrochemical techniques. The experimental data suggest that the inhibition efficiency increases with increasing NaCl concentration in the presence of 0.0002 M o-phenanthroline, but decreases with increasing temperature. A synergistic effect is observed when o-phenanthroline and chloride ions are used together to prevent cold rolled steel corrosion in 0.5 M sulphuric acid. The polarization curves showed that the complex of o-phenanthroline and NaCl acts as a mixed type inhibitor. The experimental results suggested that the presence of chloride ions in the solution stabilized the adsorption of o-phenanthroline molecules on the metal surface and improved the inhibition efficiency of o-phenanthroline. The adsorption of the complex accords with the Langmuir adsorption isotherm. Some thermodynamic parameters such as adsorption heat, adsorption entropy and adsorption free energy have been calculated by employing thermodynamic equations. Kinetic parameters such as apparent activation energy and pre-exponential factor have been calculated and discussed

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

International Nuclear Information System (INIS)

Smith, W.H.

1992-10-01

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

On the function and fate of chloride ions in amyloidogenic self-assembly of insulin in an acidic environment: salt-induced condensation of fibrils.

Science.gov (United States)

Babenko, Viktoria; Surmacz-Chwedoruk, Weronika; Dzwolak, Wojciech

2015-02-24

Formation of amyloid fibrils is often facilitated in the presence of specific charge-compensating ions. Dissolved sodium chloride is known to accelerate insulin fibrillation at low pH that has been attributed to the shielding of electrostatic repulsion between positively charged insulin molecules by chloride ions. However, the subsequent fate of Cl(-) anions; that is, possible entrapment within elongating fibrils or escape into the bulk solvent, remains unclear. Here, we show that, while the presence of NaCl at the onset of insulin aggregation induces structural variants of amyloid with distinct fingerprint infrared features, a delayed addition of salt to fibrils that have been already formed in its absence and under quiescent conditions triggers a "condensation effect": amyloid superstructures with strong chiroptical properties are formed. Chloride ions appear to stabilize these superstructures in a manner similar to stabilization of DNA condensates by polyvalent cations. The concentration of residual chloride ions trapped within bovine insulin fibrils grown in 0.1 M NaCl, at pD 1.9, and rinsed extensively with water afterward is less than 1 anion per 16 insulin monomers (as estimated using ion chromatography) implying absence of defined solvent-sequestered nesting sites for chloride counterions. Our results have been discussed in the context of mechanisms of insulin aggregation.

Recycling of spent lithium-ion battery with polyvinyl chloride by mechanochemical process.

Science.gov (United States)

Wang, Meng-Meng; Zhang, Cong-Cong; Zhang, Fu-Shen

2017-09-01

In the present study, cathode materials (C/LiCoO 2 ) of spent lithium-ion batteries (LIBs) and waste polyvinyl chloride (PVC) were co-processed via an innovative mechanochemical method, i.e. LiCoO 2 /PVC/Fe was co-grinded followed by water-leaching. This procedure generated recoverable LiCl from Li by the dechlorination of PVC and also generated magnetic CoFe 4 O 6 from Co. The effects of different additives (e.g. alkali metals, non-metal oxides, and zero-valent metals) on (i) the conversion rates of Li and Co and (ii) the dechlorination rate of PVC were investigated, and the reaction mechanisms were explored. It was found that the chlorine atoms in PVC were mechanochemically transformed into chloride ions that bound to the Li in LiCoO 2 to form LiCl. This resulted in reorganization of the Co and Fe crystals to form the magnetic material CoFe 4 O 6 . This study provides a more environmentally-friendly, economical, and straightforward approach for the recycling of spent LIBs and waste PVC compared to traditional processes. Copyright © 2017. Published by Elsevier Ltd.

Effects of chloride ions on corrosion of ductile iron and carbon steel in soil environments.

Science.gov (United States)

Song, Yarong; Jiang, Guangming; Chen, Ying; Zhao, Peng; Tian, Yimei

2017-07-31

Chloride is reported to play a significant role in corrosion reactions, products and kinetics of ferrous metals. To enhance the understanding of the effects of soil environments, especially the saline soils with high levels of chloride, on the corrosion of ductile iron and carbon steel, a 3-month corrosion test was carried out by exposing ferrous metals to soils of six chloride concentrations. The surface morphology, rust compositions and corrosion kinetics were comprehensively studied by visual observation, scanning electron microscopy (SEM), X-Ray diffraction (XRD), weight loss, pit depth measurement, linear polarization and electrochemical impedance spectroscopy (EIS) measurements. It showed that chloride ions influenced the characteristics and compositions of rust layers by diverting and participating in corrosion reactions. α-FeOOH, γ-FeOOH and iron oxides were major corrosion products, while β-Fe 8 O 8 (OH) 8 Cl 1.35 rather than β-FeOOH was formed when high chloride concentrations were provided. Chloride also suppressed the decreasing of corrosion rates, whereas increased the difficulty in the diffusion process by thickening the rust layers and transforming the rust compositions. Carbon steel is more susceptible to chloride attacks than ductile iron. The corrosion kinetics of ductile iron and carbon steel corresponded with the probabilistic and bilinear model respectively.

Chloride flux in phagocytes.

Science.gov (United States)

Wang, Guoshun

2016-09-01

Phagocytes, such as neutrophils and macrophages, engulf microbes into phagosomes and launch chemical attacks to kill and degrade them. Such a critical innate immune function necessitates ion participation. Chloride, the most abundant anion in the human body, is an indispensable constituent of the myeloperoxidase (MPO)-H2 O2 -halide system that produces the potent microbicide hypochlorous acid (HOCl). It also serves as a balancing ion to set membrane potentials, optimize cytosolic and phagosomal pH, and regulate phagosomal enzymatic activities. Deficient supply of this anion to or defective attainment of this anion by phagocytes is linked to innate immune defects. However, how phagocytes acquire chloride from their residing environment especially when they are deployed to epithelium-lined lumens, and how chloride is intracellularly transported to phagosomes remain largely unknown. This review article will provide an overview of chloride protein carriers, potential mechanisms for phagocytic chloride preservation and acquisition, intracellular chloride supply to phagosomes for oxidant production, and methods to measure chloride levels in phagocytes and their phagosomes. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

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

Energy Technology Data Exchange (ETDEWEB)

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

2007-11-01

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

The Effects of Calcium Ions on the Flotation of Sillimanite Using Dodecylammonium Chloride

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Zhijie Chen

2017-02-01

Full Text Available The effects of Ca2+ ions on the flotation of sillimanite using dodecylammonium chloride as a collector were investigated by micro-flotation tests, zeta potential measurements, solution chemistry analysis and molecular dynamics (MD simulation. The micro-flotation results indicated that Ca2+ ions remarkably inhibit the flotation of sillimanite in the pH range of 2.0–9.0. The point of zero charge (PZC of sillimanite changed from 5.4 to 6.1 with the addition of Ca2+ ions. Meanwhile, the calculated concentration of RNH3+ in the sillimanite interface layer decreased in the presence of Ca2+ ions. The results of MD simulation revealed that Ca2+ ions have strong binding energy with the sillimanite (010 surface, and the binding energy of RNH3+ with sillimanite (010 surface reduced in the presence of Ca2+ ions. The conclusions drawn from the computations are in good agreement with the experimental results.

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

Science.gov (United States)

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

2015-05-01

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

Incorporation mechanism for doping of metal ions into a passivating film at the lithium/thionyl chloride interface

Science.gov (United States)

Danilov, V. G.; Shikin, V. I.

1993-05-01

Effects of iron and titanium ions on corrosion processes of lithium in thionyl chloride electrolytes have been studied. Laws for the growth of the passivating film on the type and concentration of doped ions have been established, and equations for these are suggested. A stepwise mechanism of dopant incorporation into passivating film structure is presented.

Solvent and ion-pairing effects on the chlorine kinetic isotope effect of t-butyl chloride

International Nuclear Information System (INIS)

McCord, B.R.

1986-01-01

The solvolysis of t-butyl chloride and 1-adamantyl chloride was measured in mixtures of aqueous 2,2,2-trifluoroethanols and in mixtures of aqueous ethanols. The KIEs for t-butyl chloride at 25 0 C in 94% TFE/water, and 60% ethanol/water (solvent mixtures with similar polarity) were 1.0097 and 1.0104 respectively. Further investigations showed a KIE of 1.0104 in 50% ethanol/water and 1.0105 in 100% ethanol while the isotope effect in the fluorinated ethanols rose from 1.0094 in 99% TFE/water to 1.0101 in 70% ethanol/water. The KIE in all these solvents were shown to be directly proportional to the nucleophilicity of the solvent and indicates nucleophilic attack on an ion pair. The similar KIE of t-butyl chloride in the ethanol/water solvents was found to support the contention that solvent polarity exerts a minimal effect on the chlorine KIE

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

International Nuclear Information System (INIS)

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

1993-01-01

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

Spectrophotometric Analysis of the Kinetic of Pd(II Chloride Complex Ions Sorption Process from Diluted Aqua Solutions Using Commercially Available Activated Carbon

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Wojnicki M.

2017-12-01

Full Text Available In this paper, results of adsorption kinetic studies of Pd(II chloride complex ions on activated carbon Organosrob 10 CO are presented. Spectorphotometrical method was applied to investigate the process. Kinetic model was proposed, and fundamental thermodynamic parameters were determined. Proposed kinetic model describes well observed phenomenon in the studied range of concentration of Pd(II chloride complex ions as well, as concentration of activated carbon.

Incorporation mechanism for doping of metal ions into a passive film at the lithium/thionyl chloride interface

Energy Technology Data Exchange (ETDEWEB)

Danilov, V.G. (Siberian Inst. of Tech., Krasnoyarsk (Russian Federation). Lab. of Electrochemistry); Shilkin, V.I. (Siberian Inst. of Tech., Krasnoyarsk (Russian Federation). Lab. of Electrochemistry)

1993-05-01

Effects of iron and titanium ions on corrosion processes of lithium in thionyl chloride electrolytes have been studied. Laws for the growth of the passivating film on the type and concentration of doped ions have been established, and equations for these are suggested. A stepwise mechanism of dopant incorporation into passivating film structure is presented. (orig.)

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

International Nuclear Information System (INIS)

Costa, Carla Regina; Montilla, Francisco; Morallon, Emilia; Olivi, Paulo

2009-01-01

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

Study of chloride ion transport of composite by using cement and starch as a binder

Energy Technology Data Exchange (ETDEWEB)

Armynah, Bidayatul; Halide, Halmar; Zahrawani,; Reski, Nurhadi; Tahir, Dahlang, E-mail: dtahir@fmipa.unhas.ac.id [Department of Physics, Hasanuddin University, Makassar 90245 Indonesia (Indonesia)

2016-03-11

This study presents the chemical bonding and the structural properties of composites from accelerator chloride test migration (ACTM). The volume fractions between binder (cement and starch) and charcoal in composites are 20:80 and 60:40. The effect of the binder to the chemical composition, chemical bonding, and structural properties before and after chloride ion passing through the composites was determined by X-ray fluorescence (XRF), by Fourier transform infra-red (FTIR), and x-ray diffraction (XRD), respectively. From the XRD data, XRF data, and the FTIR data shows the amount of chemical composition, the type of binding, and the structure of composites are depending on the type of binder. The amount of chloride migration using starch as binder is higher than that of cement as a binder due to the density effects.

Electrochemical corrosion characteristics of aluminium alloy 6061 T6 in demineralized water containing 0.1 % chloride ion

International Nuclear Information System (INIS)

Zaifol Samsu; Muhammad Daud; Siti Radiah Mohd Kamarudin; Mohd Saari Ripin; Rusni Rejab; Mohd Shariff Sattar

2012-01-01

Direct current electrochemical method is one of the techniques has been used to study the corrosion behaviour of metal/alloy in its environment. This paper attempts to investigate the corrosion behaviour of Al 6061 T6 immersed in Reactor TRIGA Mark II pool water containing about 0.1% NaCl content. The result shown that the corrosion rate value of the aluminium 6061 T6 increased with the presence of 0.1 % Ion Chloride content in the demineralized water reactor pool as compared to normal demineralized water. This is due to aggressiveness of chloride ion attack to metal surface. Beside corrosion rate analysis, the further tests such as corrosion behaviour diagram, cyclic polarization have been carried and the results have been reported. (author)

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

Directory of Open Access Journals (Sweden)

Xuanmao Chen

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

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

International Nuclear Information System (INIS)

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

2014-01-01

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

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

Science.gov (United States)

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

2018-01-01

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

Chronopotentiometric chloride sensing using transition time measurement

NARCIS (Netherlands)

Abbas, Yawar; de Graaf, D.B.; Olthuis, Wouter; van den Berg, Albert

2013-01-01

Detection of chloride ions is crucial to accurately access the concrete structure durability[1]. The existing electrochemical method of chloride ions detection in concrete, potentiometry[1], is not suitable for in-situ measurement due to the long term stability issue of conventional reference

Laboratory investigation of electro-chemical chloride extraction from concrete with penetrated chloride

NARCIS (Netherlands)

Polder, R.B.; Hondel, A.W.M. van den

2002-01-01

Chloride extraction of concrete is a short-term electrochemical treatment against corrosion of reinforcing steel. The aim is to remove chloride ions from the concrete cover in order to reinstate passive behaviour. Physically sound concrete is left in place. To make this method more predictable and

Silver release from nanocomposite Ag/alginate hydrogels in the presence of chloride ions: experimental results and mathematical modeling

Energy Technology Data Exchange (ETDEWEB)

Kostic, Danijela, E-mail: dkostic@tmf.bg.ac.rs [Innovation Center of the Faculty of Technology and Metallurgy (Serbia); Vidovic, Srđan, E-mail: srdjanhi@gmail.com; Obradovic, Bojana, E-mail: bojana@tmf.bg.ac.rs [University of Belgrade, Faculty of Technology and Metallurgy (Serbia)

2016-03-15

A stepwise experimental and mathematical modeling approach was used to assess silver release from nanocomposite Ag/alginate microbeads in wet and dried forms into water and into normal saline solution chosen as a simplified model for certain biological fluids (e.g., blood plasma, wound exudates, sweat, etc). Three phenomena were connected and mathematically described: diffusion of silver nanoparticles (AgNPs) within the alginate hydrogel, AgNP oxidation/dissolution and reaction with chloride ions, and diffusion of the resultant silver-chloride species. Mathematical modeling results agreed well with the experimental data with the AgNP diffusion coefficient estimated as 1.3 × 10{sup −18} m{sup 2} s{sup −1}, while the first-order kinetic rate constant of AgNP oxidation/dissolution and diffusivity of silver-chloride species were shown to be inversely related. In specific, rapid rehydration and swelling of dry Ag/alginate microbeads induced fast AgNP oxidation/dissolution reaction with Cl{sup −} and AgCl precipitation within the microbeads with the lowest diffusivity of silver-chloride species compared to wet microbeads in normal saline. The proposed mathematical model provided an insight into the phenomena related to silver release from nanocomposite Ca-alginate hydrogels relevant for use of antimicrobial devices and established, at the same time, a basis for further in-depth studies of AgNP interactions in hydrogels in the presence of chloride ions.

Intensity of f-f bands of neodymium chloride alcohol solvates

International Nuclear Information System (INIS)

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

1981-01-01

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

Aqueous photochemical reactions of chloride, bromide, and iodide ions in a diode-array spectrophotometer. Autoinhibition in the photolysis of iodide ions.

Science.gov (United States)

Kalmár, József; Dóka, Éva; Lente, Gábor; Fábián, István

2014-03-28

The aqueous photoreactions of three halide ions (chloride, bromide and iodide) were studied using a diode array spectrophotometer to drive and detect the process at the same time. The concentration and pH dependences of the halogen formation rates were studied in detail. The experimental data were interpreted by improving earlier models where the cage complex of a halogen atom and an electron has a central role. The triiodide ion was shown to exert a strong inhibiting effect on the reaction sequence leading to its own formation. An assumed chemical reaction between the triiodide ion and the cage complex interpreted the strong autoinhibition effect. It is shown that there is a real danger of unwanted interference from the photoreactions of halide ions when halide salts are used as supporting electrolytes in spectrophotometric experiments using a relatively high intensity UV light source.

Microbial Growth in the Magnesium- Chloride - Sodium- Sulphate Ion System: Implications for Habitability in Terrestrial and Extraterrestrial Salts

Science.gov (United States)

Loudon, C. M.; Aka, S.; Cockell, C. S.

2017-12-01

Icy moons in the outer solar system are key targets in the search for extra-terrestrial life as there is evidence that they harbour subsurface oceans. Observational evidence of icy moons such as Europa suggest that these likely brine oceans should be composed of chloride and sulphate salts. The effects of the ions that compose these salts on biology and how the interactions between them can create geochemical and geophysical barriers to life are poorly understood. Here we present an in depth study of four microorganisms grown in solutions with varying combinations of the magnesium- chloride- sodium- sulphate ions. We find that the ion composition of the brine solution can have a large effect on growth. Whilst the water activity must be permissible for growth we found that this alone could not predict the effects of the ions on growth, chaotropic effects and ion specific effects influenced by the specific physiology of organisms are also evident. For this reason we conclude that simply knowing which salts are present on icy moons is not sufficient information to determine their potential habitibility. A full sample of any brine ocean would need to be studied to fully determine the potential for biology on these outer solar system satellites.

Chloride ion-catalyzed generation of difluorocarbene for efficient preparation of gem-difluorinated cyclopropenes and cyclopropanes

KAUST Repository

Wang, Fei; Zhang, Wei; Zhu, Jieming; Li, Huaifeng; Huang, Kuo-Wei; Hu, Jinbo

2011-01-01

A chloride ion-catalyzed generation of difluorocarbene from a relatively non-toxic and inexpensive precursor, Me3SiCF2Cl (1), under mild and neutral conditions leads to an efficient preparation of gem-difluorocyclopropenes and difluorocyclopropanes through [2 + 1] cycloaddition reactions with alkynes and alkenes, respectively. © 2011 The Royal Society of Chemistry.

Density-functional theory investigation of Al pitting corrosion in electrolyte containing chloride ions

Energy Technology Data Exchange (ETDEWEB)

Liu, Min [National Center for Materials Service Safety, University of Science and Technology Beijing, Beijing 100083 (China); Jin, Ying, E-mail: yjin@ustb.edu.cn [National Center for Materials Service Safety, University of Science and Technology Beijing, Beijing 100083 (China); Zhang, Chuanhui [National Center for Materials Service Safety, University of Science and Technology Beijing, Beijing 100083 (China); Leygraf, Christofer [Division of Surface and Corrosion Science, Department of Chemistry, KTH Royal Institute of Technology, SE-10044 Stockholm (Sweden); Wen, Lei [National Center for Materials Service Safety, University of Science and Technology Beijing, Beijing 100083 (China)

2015-12-01

Highlights: • Cl{sup −} led to the elongation of Al−O bond and the weakened binding between Al layers in scenario i. • Al−O interaction weakened whereas an intensive hybridization peak at −0.18 Ha between Al-3p with Cl-3p showed in scenario ii. • Substructures such as AlCl{sub 3} and Al{sub 2}Cl{sub 5} formed in scenario iii when the Cl{sup −} coverage was larger than 2/3 ML of a monolayer. - Abstract: The behavior of chloride ions (Cl{sup −}) and oxygen species (the oxygen atom, O or molecular oxygen, O{sub 2}) on Al(1 1 1) surface has been studied by density functional theory calculations in order to deepen the molecular understanding of fundamental processes leading to pitting of aluminum (Al). The adsorption behavior of individual species, Cl{sup −}, O atom and O{sub 2} was determined first. Subsequently, three possible scenarios in different pitting stages were modeled exploring the repassivation and dissolution of Al in neutral electrolyte containing Cl{sup −}. In scenario i, it was found that Cl{sup −} can hardly destroy even an O-monolayer on Al(1 1 1) surface, however may lead to the elongation of Al−O bond and the weakened binding between the first Al layer and subsequent Al layers. Both O{sub 2} and Cl{sup −} were simultaneously introduced onto Al(1 1 1) in scenario ii. The result showed a weakened Al−O interaction and an intensive hybridization peak at −0.18 Ha between Al-3p with Cl-3p suggesting insufficient repassivation behavior of Al under this condition. Finally, scenario iii mimicked different local environmental conditions in pits formed on Al. At low coverage of Cl{sup −}, chloride ions had little effect on surface relaxation. The interaction among chloride ions and Al surface became stronger as Cl{sup −} coverage increased. Surface Al atoms dissolved gradually and substructures such as AlCl{sub 3} and Al{sub 2}Cl{sub 5} formed when the coverage was larger than 2/3 ML of a monolayer.

Amperometric Sensor for Detection of Chloride Ions†

Science.gov (United States)

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

2008-01-01

Chloride ion sensing is important in many fields such as clinical diagnosis, environmental monitoring and industrial applications. We have measured chloride ions at a carbon paste electrode (CPE) and at a CPE modified with solid AgNO3, a solution of AgNO3 and/or solid silver particles. Detection limits (3 S/N) for chloride ions were 100 μM, 100 μM and 10 μM for solid AgNO3, solution of AgNO3 and/or solid silver particles, respectively. The CPE modified with silver particles is the most sensitive to the presence chloride ions. After that we approached to the miniaturization of the whole electrochemical instrument. Measurements were carried out on miniaturized instrument consisting of a potentiostat with dimensions 35 × 166 × 125 mm, screen printed electrodes, a peristaltic pump and a PC with control software. Under the most suitable experimental conditions (Britton-Robinson buffer, pH 1.8 and working electrode potential 550 mV) we estimated the limit of detection (3 S/N) as 500 nM. PMID:27873832

Novel modified poly vinyl chloride blend membranes for removal of heavy metals from mixed ion feed sample

Energy Technology Data Exchange (ETDEWEB)

Nayak, Vignesh; Jyothi, M.S. [Centre for Nano and Material Sciences, Jain University, Jain Global Campus, Kanakapura Ramanagaram, Bangalore, 562112 (India); Balakrishna, R. Geetha, E-mail: br.geetha@jainuniversity.ac.in [Centre for Nano and Material Sciences, Jain University, Jain Global Campus, Kanakapura Ramanagaram, Bangalore, 562112 (India); Padaki, Mahesh, E-mail: sp.mahesh@jainuniversity.ac.in [Centre for Nano and Material Sciences, Jain University, Jain Global Campus, Kanakapura Ramanagaram, Bangalore, 562112 (India); National University of Science and Technology “MISIS”, Moscow, 119049 (Russian Federation); Deon, Sebastien [Institut UTINAM, UMR CNRS 6213, Université de Bourgogne-Franche-Comté,16 route de Gray, Besançon Cedex 25030 (France)

2017-06-05

Highlights: • Work reports the novel modification of poly vinyl chloride (PVC) using newly developed method. • Blend membranes were prepared using modified PVC and polysulfone in different compositions. • The prepared blend membranes were used for separation of different heavy metal ions. • The blend membranes showed improved rejection of heavy metal ions in comparison to Commercial NF 270 membrane. - Abstract: Herein, an attempt has been made to prepare a novel membrane with good efficiency for removal of heavy metal ions namely lead (Pb), cadmium (Cd) and chromium (Cr). 4-amino benzoic acid (ABA) was covalently grafted onto the poly vinyl chloride (PVC) backbone by C−N bond to enhance the hydrophilicity. {sup 1}H NMR and ATR-IR spectroscopy analysis confirmed the chemical modification of PVC. Further the modified polymer was blended in different compositions with polysulfone (PSf) for optimization. Morphological changes that occurred in blend membranes, due to the incorporation of modified PVC was studied by AFM and SEM techniques. The effect on hydrophilicity and performance of blends owing to incorporation of modified PVC was evaluated by water uptake, contact angle and flux studies. The density of functional groups in blends was analyzed by its ion-exchange capacity. Batch wise filtration of metal ions was carried out and the effect of pressure, feed pH and interference of ions was thoroughly investigated. Essentially, 100% rejection was obtained for all the metal ions in acidic pH with a productivity of 2.56 l/m{sup 2} h. The results were correlated with the results of commercially available NF 270 membrane under the same operating conditions.

Novel modified poly vinyl chloride blend membranes for removal of heavy metals from mixed ion feed sample

International Nuclear Information System (INIS)

Nayak, Vignesh; Jyothi, M.S.; Balakrishna, R. Geetha; Padaki, Mahesh; Deon, Sebastien

2017-01-01

Highlights: • Work reports the novel modification of poly vinyl chloride (PVC) using newly developed method. • Blend membranes were prepared using modified PVC and polysulfone in different compositions. • The prepared blend membranes were used for separation of different heavy metal ions. • The blend membranes showed improved rejection of heavy metal ions in comparison to Commercial NF 270 membrane. - Abstract: Herein, an attempt has been made to prepare a novel membrane with good efficiency for removal of heavy metal ions namely lead (Pb), cadmium (Cd) and chromium (Cr). 4-amino benzoic acid (ABA) was covalently grafted onto the poly vinyl chloride (PVC) backbone by C−N bond to enhance the hydrophilicity. 1 H NMR and ATR-IR spectroscopy analysis confirmed the chemical modification of PVC. Further the modified polymer was blended in different compositions with polysulfone (PSf) for optimization. Morphological changes that occurred in blend membranes, due to the incorporation of modified PVC was studied by AFM and SEM techniques. The effect on hydrophilicity and performance of blends owing to incorporation of modified PVC was evaluated by water uptake, contact angle and flux studies. The density of functional groups in blends was analyzed by its ion-exchange capacity. Batch wise filtration of metal ions was carried out and the effect of pressure, feed pH and interference of ions was thoroughly investigated. Essentially, 100% rejection was obtained for all the metal ions in acidic pH with a productivity of 2.56 l/m 2 h. The results were correlated with the results of commercially available NF 270 membrane under the same operating conditions.

Influence of chloride ion concentration on the corrosion behavior of Al-bearing TRIP steels

Energy Technology Data Exchange (ETDEWEB)

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

2011-10-17

Highlights: {yields} Systematic increase of chloride concentration has a critical influence on TRIP steel corrosion. {yields} TRIP microalloyed with Nb and Cr showed lower corrosion rate and smaller threshold Cl{sup -} value. {yields} Increasing Al content by 220 times in the TRIP deteriorates its corrosion behavior. {yields} Impedance results and surface examinations confirmed the obtained results. - Abstract: The effect of a systematic increase of chloride ion concentration on the electrochemical corrosion behavior of two types of Al-bearing TRIP steels (T{sub 1} and T{sub 2}) was studied in aqueous NaCl solutions. Several electrochemical techniques were used comprising open circuit potential measurements, potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS). Chloride concentration has a critical influence on the corrosion rate of the two tested steel samples. For both steels the corrosion rate first increased with increasing chloride content up to a certain critical concentration (CC), and then decreased in solution with chloride level higher than the threshold value. TRIP steel T{sub 1} microalloyed with Nb and Cr as compared to steel T{sub 2} not containing these two elements, exhibited lower corrosion rate and smaller CC value, indicating better corrosion resistance to chloride attack, albeit the Al content in T{sub 2} is 220 times higher than that in T{sub 1}. This is because Nb alloyed with TRIP steel likely enhances the formation on the surface of a stable rust layer enriched with other passivating elements Al, Cu, Cr and Ni, which has higher corrosion resistance and hence improve greatly the passive performance of the TRIP sample. The ac impedance data are in good agreement with the OCP and dc polarization measurements. Surface examinations via scanning electron microscope confirmed well the obtained results.

Influence of chloride ion concentration on the corrosion behavior of Al-bearing TRIP steels

International Nuclear Information System (INIS)

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

2011-01-01

Highlights: → Systematic increase of chloride concentration has a critical influence on TRIP steel corrosion. → TRIP microalloyed with Nb and Cr showed lower corrosion rate and smaller threshold Cl - value. → Increasing Al content by 220 times in the TRIP deteriorates its corrosion behavior. → Impedance results and surface examinations confirmed the obtained results. - Abstract: The effect of a systematic increase of chloride ion concentration on the electrochemical corrosion behavior of two types of Al-bearing TRIP steels (T 1 and T 2 ) was studied in aqueous NaCl solutions. Several electrochemical techniques were used comprising open circuit potential measurements, potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS). Chloride concentration has a critical influence on the corrosion rate of the two tested steel samples. For both steels the corrosion rate first increased with increasing chloride content up to a certain critical concentration (CC), and then decreased in solution with chloride level higher than the threshold value. TRIP steel T 1 microalloyed with Nb and Cr as compared to steel T 2 not containing these two elements, exhibited lower corrosion rate and smaller CC value, indicating better corrosion resistance to chloride attack, albeit the Al content in T 2 is 220 times higher than that in T 1 . This is because Nb alloyed with TRIP steel likely enhances the formation on the surface of a stable rust layer enriched with other passivating elements Al, Cu, Cr and Ni, which has higher corrosion resistance and hence improve greatly the passive performance of the TRIP sample. The ac impedance data are in good agreement with the OCP and dc polarization measurements. Surface examinations via scanning electron microscope confirmed well the obtained results.

Effects of anodic potential and chloride ion on overall reactivity in electrochemical reactors designed for solar-powered wastewater treatment.

Science.gov (United States)

Cho, Kangwoo; Qu, Yan; Kwon, Daejung; Zhang, Hao; Cid, Clément A; Aryanfar, Asghar; Hoffmann, Michael R

2014-02-18

We have investigated electrochemical treatment of real domestic wastewater coupled with simultaneous production of molecular H2 as useful byproduct. The electrolysis cells employ multilayer semiconductor anodes with electroactive bismuth-doped TiO2 functionalities and stainless steel cathodes. DC-powered laboratory-scale electrolysis experiments were performed under static anodic potentials (+2.2 or +3.0 V NHE) using domestic wastewater samples, with added chloride ion in variable concentrations. Greater than 95% reductions in chemical oxygen demand (COD) and ammonium ion were achieved within 6 h. In addition, we experimentally determined a decreasing overall reactivity of reactive chlorine species toward COD with an increasing chloride ion concentration under chlorine radicals (Cl·, Cl2(-)·) generation at +3.0 V NHE. The current efficiency for COD removal was 12% with the lowest specific energy consumption of 96 kWh kgCOD(-1) at the cell voltage of near 4 V in 50 mM chloride. The current efficiency and energy efficiency for H2 generation were calculated to range from 34 to 84% and 14 to 26%, respectively. The hydrogen comprised 35 to 60% by volume of evolved gases. The efficacy of our electrolysis cell was further demonstrated by a 20 L prototype reactor totally powered by a photovoltaic (PV) panel, which was shown to eliminate COD and total coliform bacteria in less than 4 h of treatment.

Dynamic [Cl-]i measurement with chloride sensing quantum dots nanosensor in epithelial cells

International Nuclear Information System (INIS)

Wang Yuchi; Mao Hua; Wong, Lid B

2010-01-01

We have synthesized a chloride sensing quantum dots (QD) nanosensor, Cl-QD, for the dynamic measurements of chloride ion concentration in the millimolar range, a sensitivity that is applicable to most physiological intracellular chloride ion concentration ([Cl - ] i ) measurements in epithelial cells. The Cl-QD is synthesized by conjugating an anion receptor, 1-(2-mercapto-ethyl)-3-phenyl-thiourea (MEPTU) to a water soluble CdSe/ZnS QD at an emission wavelength of 620 nm. Upon binding of chloride ions to the Cl-QD, a photo-induced electron transfer mechanism caused the fluorescence of the QD to quench. This resulted in an inversely proportional relationship between the chloride ion concentration and the fluorescence intensity of the Cl-QD. We have utilized this Cl-QD to measure [Cl - ] i in T84 and CF-PAC cultured cells, with either the C1C-2 or CFTR chloride channels being manipulated by pharmacological chloride channel activators and inhibitors. Activations of C1C-2 and CFTR chloride channels in T84 by the respective lubiprostone and genistein caused predictive increases in the fluorescence of the Cl-QD, i.e., a decrease of [Cl - ] i . Conversely, glibenclamide, a chloride channel inhibitor, applied to the CF-PAC cells caused a predictable decrease in the fluorescence of Cl-QD due to the increase of [Cl - ] i . These are the first data in using QD-based chloride ion sensors for dynamic measurements of intracellular chloride ion concentrations in epithelial cells.

Thermogravimetry for optimization of chloride pyro hydrolytic separations in zirconia-magnesia matrix

International Nuclear Information System (INIS)

Pires, M.A.F.; Dantas, E.S.K.

1992-08-01

A fast and accurate method for chloride ion determination in zirconia-magnesia matrix was studied the method consists in the pyro hydrolysis of the oxides at 900 o C, using a quartz apparatus, during thirty minutes and further determination of the chloride ion collected by means of either ion-selective electrode or ion chromatography. The thermogravimetric curves (TG curves) of the metal oxides and oxychlorides provide all the information about the chloride ion evolution temperature and the influence of pyro hydrolytic accelerators (U 3 O 8 ) on ion evolution. (author)

Breakthrough properties of chloride ions in columns of lead phosphate hydroxide

International Nuclear Information System (INIS)

Akiba, Kenichi; Hashimoto, Hiroyuki; Mimura, Hitoshi; Shindo, Manabu.

1994-01-01

Breakthrough properties of chloride ion (Cl - ) have been studied by using columns packed with a granular anion-exchanger of lead phosphate hydroxide (Pb 10 (PO 4 ) 6 (OH) 2 , IXE-1000G). The column utilization of the ratio of breakthrough capacity to total capacity increased with decreasing particle size and increasing temperature. The collection of Cl - from a simulated waste solution was improved by the addition of cation-exchange to IXE-1000G; the adsorption capacity of the column of IXE-1000G/IXE-300G (Sb type cation-exchanger) was over 0.16 mmol Cl - /g, yielding a relatively high column utilization of 75%. (author)

Investigation of the pitting of aluminum induced by chloride ions by holographic microphotography

Directory of Open Access Journals (Sweden)

LIANG LI

2008-05-01

Full Text Available Holographic microphotography was used to investigate the dynamic processes of pitting during anodic dissolution of aluminum in a solution containing chloride ions. The induction and the follow-up propagation processes of the pitting were observed in real-time. A simple model of the propagating process of the pitting was deduced from the result of the holograms of the Al/electrolyte interface. The results prove that holographic microphotography is a useful tool to study the dynamic processes of pitting.

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

International Nuclear Information System (INIS)

Sebrao, M.Z.

1982-01-01

The kinetics of the dissolution of stainless steel AISI 430 in the presence of chloride and sulphate ions has been studied in terms of the ion concentration, the pH variation, and the velocity of the working electrode. The experimental method utilized was the potentiostatic anodic polarization, and the reactants used were NaCl and Na 2 SO 4 at room temperature. Atomic Absorption spectrophotometry and Auger Electrons spectroscopy (AES) analyses were made in order to support the interpretation of results obtained by means of the potentiostatic polarization method. (author)

Facile Preparation of Chloride-Conducting Membranes : First Step towards a Room-Temperature Solid-State Chloride-Ion Battery

NARCIS (Netherlands)

Gschwind, Fabienne; Steinle, Dominik; Sandbeck, Daniel; Schmidt, Celine; von Hauff, Elizabeth

2016-01-01

Three types of chloride-conducting membranes based on polyvinyl chloride, commercial gelatin, and polyvinyldifluoride-hexafluoropolymer are introduced in this report. The polymers are mixed with chloride-containing salts, such as tetrabutylammonium chloride, and cast to form membranes. We studied

[Application of Brownian dynamics to the description of transmembrane ion flow as exemplified by the chloride channel of glycine receptor].

Science.gov (United States)

Boronovskiĭ, S E; Nartsissov, Ia R

2009-01-01

Using the Brownian dynamics of the movement of hydrated ion in a viscous water solution, a mathematical model has been built, which describes the transport of charged particles through a single protein pore in a lipid membrane. The dependences of transmembrane ion currents on ion concentrations in solution have been obtained. It was shown that, if the geometry of a membrane pore is identical to that of the inner part of the glycine receptor channel and there is no ion selectivity, then the values of both chloride and sodium currents are not greater than 0.5 pA at the physiological concentrations of these ions. If local charge heterogeneity caused by charged amino acid residues of transmembrane protein segments is included into the model calculations, the chloride current increases to about 3.7 pA, which exceeds more than seven times the value for sodium ions under the conditions of the complex channel geometry in the range of physiological concentrations of ions in the solution. The model takes changes in the density of charge distribution both inside the channel and near the protein surface into account. The alteration of pore geometry can be also considered as a parameter at the researcher's option. Thus, the model appears as an effective tool for the description of transmembrane currents for other types of membrane channels.

Determination of lutetium (III) hydrolysis constants in the middle of ion force 1M sodium chloride at 303 K

International Nuclear Information System (INIS)

Jimenez R, M.; Solache R, M.J.; Ramirez G, J.J.; Rojas H, A.

1997-01-01

With the purpose to complete information about the lutetium (III) hydrolysis constants here is used the potentiometric method to determine those in the middle of ion force 1M sodium chloride at 303 K. (Author)

NMR study of thallium(I) ions in molten binary mixtures of nitrates and chlorides

International Nuclear Information System (INIS)

Nakamura, Yoshio; Kitazawa, Yukiharu; Shimoji, Mitsuo; Shimokawa, Shigezo.

1983-01-01

The chemical shifts of 205 Tl NMR in molten binary mixtures of nitrates and those of chlorides have been measured as a function of composition and temperature. The shifts increase in the diamagnetic direction with decreasing the size of foreign cations and increase in the paramagnetic direction with increasing temperature. These results are interpreted by changes in the overlap of orbitals of the Tl + ion and the anion, which depend upon composition and temperature. (author)

Study on pore structure and diffusion coefficient of chloride ion in hardened low-alkaline cement

International Nuclear Information System (INIS)

Mihara, Morihiro; Torii, Kazuyuki

2009-03-01

Low-alkaline cement using pozzolans is under consideration as a possible filling and structural material in geological disposal for long-lived radioactive waste. Silica fume and fly ash are used to develop the low-alkaline cement which is named HFSC, High-volume Fly ash Silica fume Cement. In this study, pore structure and diffusivity of chloride ion in HFSC pastes were investigated in order to understand the fundamental transport properties of ions. HFSC which included different contents of fly ash (40%, 50% and 60%) with silica fume (20%) and ordinary Portland (OPC) cement were prepared. Hardened cement pastes were supplied to pore structure analysis and in-diffusion experiment with NaCl and CaCl 2 solution. Mercury intrusion method (MIP) commonly used and image analysis of backscattered electron microscopy (BSE) for pore in hardened cement paste were performed to investigate the pore structure. The porosity of HFSC was larger than that of OPC measured by MIP. However, pore diameter increasing pore volume of HFSC was smaller than that of OPC. It was observed that lager pores were in HFSC than in OPC from BSE. These large pores in HFSC were originated from cenosphere of FA. The apparent diffusivity of chloride in HFSC with fly ash of 40% showed smallest value in the cement pastes. It was concluded that the smallest diffusion coefficient was caused by a pore of HFSC which had a bended structure and ion exclusion/filtration effect. (author)

Study by X-ray photoelectron spectroscopy (XPS) and radiochemistry (Cl36) of the interaction of chloride ions with a passive film formed on nickel

International Nuclear Information System (INIS)

Herbelin, Jean-Marc

1990-01-01

This research thesis reports the study of the influence of chlorides on nickel passivation by using a radiochemical method based on the use of the Cl 36 isotope and the X-ray photoelectron spectroscopy (XPS). The first one allows the in-situ determination of the adsorption of chlorides on the surface, or their inclusion in surface films during the electrochemical treatment. The XPS analysis allows the characterization of modifications induced by chlorides in passive films. The obtained results allow a better understanding in the interpretation of the mechanisms of corrosion induced by chloride ions [fr

Determination of chloride and sulphur in sodium by ion chromatography and its application to PFBR sodium samples

International Nuclear Information System (INIS)

Vijayalakshmi, S.; Ushalakshmi, K.

2011-01-01

Analytical method using ion chromatography was developed for the determination of chloride and sulphur in sodium. In this method, sodium was dissolved in water and various sulphur species present in the sample was oxidized to sulphate using hydrogen peroxide. Carbon dioxide gas was passed through the solution to convert sodium hydroxide to carbonate solution. The resulting sample solution was analysed using suppressed Ion chromatography employing carbonate eluent. This method was applied to the analysis of sodium samples procured for prototype fast breeder reactor. (author)

Ion chromatography for the precise analysis of chloride and sodium in sweat for the diagnosis of cystic fibrosis

NARCIS (Netherlands)

Doorn, J.; Storteboom, T. T. R.; Mulder, A. M.; de Jong, W. H. A.; Rottier, B. L.; Kema, I. P.

BACKGROUND: Measurement of chloride in sweat is an essential part of the diagnostic algorithm for cystic fibrosis. The lack in sensitivity and reproducibility of current methods led us to develop an ion chromatography/high-performance liquid chromatography (IC/HPLC) method, suitable for the analysis

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

International Nuclear Information System (INIS)

Carranza, Ricardo M.

2009-01-01

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

Electroplating Ni-63 metal ions in chloride bath on the Cu-plate

Energy Technology Data Exchange (ETDEWEB)

Yoo, Kwon Mo; Uhm, Young Rang; Son, Kwang Jae; Park, Keun Yung [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2014-05-15

Ni-63 plating is similar to other electroplating processes that employ soluble metal anodes. The nickel plating solution described by Watts in 1916 eventually replaced all other strategies in use up to that time. Charged Ni ions are formed by sulfate, sulfamate, chloride, and a Watts bath. However, charged Ni-63 ions are formed by dissolving metal Ni-63. Specifically, it requires the passage of direct current (DC) between two electrodes that are immersed in a conductive, aqueous solution of nickel salts. The flow of a DC causes one of the electrodes (the anode) to dissolve and the other electrode (the cathode) to become covered with nickel. The nickel in the solution is present in the form of divalent positively charged ions (Ni{sup 2+}). When the current flows, the positive ions react with two electrons (2e{sup -}) and are converted into metallic nickel (Ni{sup 0}) at the cathode surface. In the present study, we optimize and established process for the electroplating Ni-63 on Cu-plate. Nanocrystalline nickel (Ni) coatings were synthesized by DC electro deposition at a current density of 15 mA/cm{sup 2}. The bath was primarily composed of 0.2 M Ni ions, prepared by dissolving Ni-63 metal particles in HCl. The prototype for electroplating radioactive Ni-63 has been established. The electroplating was carried out by two-step processes such as preparation of ionic solution including Ni-63, and coating processes on the substrate.

Electroplating Ni-63 metal ions in chloride bath on the Cu-plate

International Nuclear Information System (INIS)

Yoo, Kwon Mo; Uhm, Young Rang; Son, Kwang Jae; Park, Keun Yung

2014-01-01

Ni-63 plating is similar to other electroplating processes that employ soluble metal anodes. The nickel plating solution described by Watts in 1916 eventually replaced all other strategies in use up to that time. Charged Ni ions are formed by sulfate, sulfamate, chloride, and a Watts bath. However, charged Ni-63 ions are formed by dissolving metal Ni-63. Specifically, it requires the passage of direct current (DC) between two electrodes that are immersed in a conductive, aqueous solution of nickel salts. The flow of a DC causes one of the electrodes (the anode) to dissolve and the other electrode (the cathode) to become covered with nickel. The nickel in the solution is present in the form of divalent positively charged ions (Ni 2+ ). When the current flows, the positive ions react with two electrons (2e - ) and are converted into metallic nickel (Ni 0 ) at the cathode surface. In the present study, we optimize and established process for the electroplating Ni-63 on Cu-plate. Nanocrystalline nickel (Ni) coatings were synthesized by DC electro deposition at a current density of 15 mA/cm 2 . The bath was primarily composed of 0.2 M Ni ions, prepared by dissolving Ni-63 metal particles in HCl. The prototype for electroplating radioactive Ni-63 has been established. The electroplating was carried out by two-step processes such as preparation of ionic solution including Ni-63, and coating processes on the substrate

Why are ionic liquid ions mainly associated in water? A Car-Parrinello study of 1-ethyl-3-methyl-imidazolium chloride water mixture

Science.gov (United States)

Spickermann, C.; Thar, J.; Lehmann, S. B. C.; Zahn, S.; Hunger, J.; Buchner, R.; Hunt, P. A.; Welton, T.; Kirchner, B.

2008-09-01

In this study we present the results of a first principles molecular dynamics simulation of a single 1-ethyl-3-methyl-imidazolium chloride [C2C1im][Cl] ion pair dissolved in 60 water molecules. We observe a preference of the in plane chloride coordination with respect to the cation ring plane as compared to the energetic slightly more demanding on top coordination. Evaluation of the different radial distribution functions demonstrates that the structure of the hydration shell around the ion pair differs significantly from bulk water and that no true ion pair dissociation in terms of completely autonomous solvation shells takes place on the timescale of the simulation. In addition, dipole moment distributions of the solvent in distinct solvation shells around different functional parts of the [C2C1im][Cl] ion pair are calculated from maximally localized Wannier functions. The analysis of these distributions gives evidence for a depolarization of water molecules close to the hydrophobic parts of the cation as well as close to the anion. Examination of the angular distribution of different OH(H2O )-X angles in turn shows a linear coordination of chloride accompanied by a tangential orientation of water molecules around the hydrophobic groups, being a typical feature of hydrophobic hydration. Based on these orientational aspects, a structural model for the obvious preference of ion pair association is developed, which justifies the associating behavior of solvated [C2C1im][Cl] ions in terms of an energetically favorable interface between the solvation shells of the anion and the hydrophobic parts of the cation.

Cytological comparison of gill chloride cells and blood serum ion concentrations in kutum (Rutilus frisii kutum spawners from brackish (Caspian Sea and fresh water (Khoshkrood River environments

Directory of Open Access Journals (Sweden)

Ghahremanzadeh Zahra

2014-09-01

Full Text Available The size and number of chloride cells and serum ion concentrations in kutum, Rutillus frisii kutum Nordman, from brackish (Caspian Sea and fresh water (Khoshkrood River environments were studied to gain a better understanding of osmoregulation in this species. Twenty mature kutum specimens were collected from the Caspian Sea (Anzali coasts, 8.49 ppt salinity and 12.4°C temperature and 20 specimens from Khoshkrood River (0.18 ppt salinity and 18°C temperature. Gill samples were analyzed histologically and concentrations of Na+, Cl- , K+, and Mg2+ ions were determined in the blood serum. Concentrations of Na+, Cl- , K+, and Mg2+ ions and osmotic pressure in mature kutum from brackish water were significantly higher than in specimens from fresh water. The average size and number of chloride cells in the fish from seawater were considerably larger than those from fresh water. The mean size of chloride cells was 6.89 ± 1.16 μm in brackish water samples and 5.1 ± 0.81 μm in river samples. The average number of chloride cells in brackish and river water samples were 16.92 and 6.57, respectively. The density and size of chloride cells increased with increases in salinity

Determination of chloride content in crystalline silicotitanate

International Nuclear Information System (INIS)

Wilmarth, W.R.

1999-01-01

Crystalline Silicotitanate (CST) is one of three options under evaluation to replace the In-Tank Precipitation process. This Salt Disposition Alternatives team identified three options for pretreatment of High Level Waste supernate: non-elutable ion exchange, precipitation with sodium tetraphenylborate or direct disposal in grout. The ion exchange option would use crystalline silicotitanate (CST). Researchers at Texas A and M and Sandia National Laboratory developed CST. The engineered form of CST was procured from UOP LLC under the trade name IONSIVreg s ign IE-911. Review of vendor literature and discussions with UOP personnel led to speculation concerning the fate of chloride ion during the manufacture process of IE-911. Walker proposed tests to examine the chloride content of CST and removal methods. This report describes the results of tests to determine the chloride levels in as received CST and washed CST

Crystal structures of salicylideneguanylhydrazinium chloride and its copper(II) and cobalt(III) chloride complexes

International Nuclear Information System (INIS)

Chumakov, Yu. M.; Tsapkov, V. I.; Bocelli, G.; Antosyak, B. Ya.; Shova, S. G.; Gulea, A. P.

2006-01-01

The crystal structures of salicylideneguanylhydrazinium chloride hydrate hemiethanol solvate (I), salicylideneguanylhydrazinium trichloroaquacuprate(II) (II), and bis(salicylideneguanylhydrazino)cobalt(III) chloride trihydrate (III) are determined using X-ray diffraction. The structures of compounds I, II, and III are solved by direct methods and refined using the least-squares procedure in the anisotropic approximation for the non-hydrogen atoms to the final factors R = 0.0597, 0.0212, and 0.0283, respectively. In the structure of compound I, the monoprotonated molecules and chlorine ions linked by hydrogen bonds form layers aligned parallel to the (010) plane. In the structure of compound II, the salicylaldehyde guanylhydrazone cations and polymer chains consisting of trichloroaquacuprate(II) anions are joined by an extended three-dimensional network of hydrogen bonds. In the structure of compound III, the [Co(LH) 2 ] + cations, chloride ions, and molecules of crystallization water are linked together by a similar network

Electrochemical corrosion study of Mg–Al–Zn–Mn alloy in aqueous ethylene glycol containing chloride ions

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Harish Medhashree

2017-01-01

Full Text Available Nowadays most of the automobiles use magnesium alloys in the components of the engine coolant systems. These engine coolants used are mainly composed of aqueous ethylene glycol along with some inhibitors. Generally the engine coolants are contaminated by environmental anions like chlorides, which would enhance the rate of corrosion of the alloys used in the coolant system. In the present study, the corrosion behavior of Mg–Al–Zn–Mn alloy in 30% (v/v aqueous ethylene glycol containing chloride anions at neutral pH was investigated. Electrochemical techniques, such as potentiodynamic polarization method, cyclic polarization and electrochemical impedance spectroscopy (EIS were used to study the corrosion behavior of Mg–Al–Zn–Mn alloy. The surface morphology, microstructure and surface composition of the alloy were studied by using the scanning electron microscopy (SEM, optical microscopy and energy dispersion X-ray (EDX analysis, respectively. Electrochemical investigations show that the rate of corrosion increases with the increase in chloride ion concentration and also with the increase in medium temperature.

Multi-scale modelling of uranyl chloride solutions

Energy Technology Data Exchange (ETDEWEB)

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

2015-01-14

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

Effects of Reinforcing Fiber and Microsilica on the Mechanical and Chloride Ion Penetration Properties of Latex-Modified Fiber-Reinforced Rapid-Set Cement Concrete for Pavement Repair

Directory of Open Access Journals (Sweden)

Woong Kim

2018-01-01

Full Text Available This study evaluated the influence of reinforcement fiber type and microsilica content on the performance of latex-modified fiber-reinforced roller-compacted rapid-hardening cement concrete (LMFRCRSC for a concrete pavement emergency repair. Experimental variables were the microsilica substitution ratio (1, 2, 3, and 4%, and the reinforcement fiber (jute versus macrosynthetic fiber. In the tests, compressive, flexural, and splitting tensile strength; chloride ion penetration resistance; and abrasion resistance were assessed. From the compressive and flexural strength tests with microsilica substitution, the 4-hour curing strength decreased as the microsilica substitution ratio increased. From the chloride ion penetration test, as the microsilica substitution ratio increased, chloride ion penetration decreased. The abrasion resistances increased with the substitution ratio of microsilica increase. Based on these test results, microsilica at a substitution ratio of 3% or less and macrosynthetic fiber as the reinforcement improved the performance of LMFRCRSC for a concrete pavement emergency repair and satisfied all of the target strength requirements.

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

International Nuclear Information System (INIS)

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

1997-01-01

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

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

Directory of Open Access Journals (Sweden)

Zahra Kaboli Tanha

2016-06-01

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

Separation of chloride and fluoride from uranium compounds and their determination by ion selective electrodes

International Nuclear Information System (INIS)

Pires, M.A.F.; Abrao, A.

1982-01-01

Fluoride and chloride must be rigorously controlled in uranium compounds, especially in ceramic grade UO 2 . Their determination is very difficult without previous uranium separation, particularly when both are at a low concentration. A simple procedure is described for this separation using a strong cationic resin to retain the uranyl ion. Both anions are determined in the effluent solution. Uranium compounds of nuclear fuel cycle, especially ammonium diuranate, ammonium uranyl tricarbonate, sodium diuranate, uranium trioxide and dioxide and uranium peroxide are dissolved in nitric acid and the solutions are percolated through the resin column. Chloride and fluoride are determined in the effluent by selective electrodes, the detection limits being 0.02 μg F - /ml and 1.0 μg Cl - /ml. The dissolution of the sample, the acidity of the solution, the measurement conditions and the sensitivity of the method are discussed. (Author) [pt

Extractive process for preparing high purity magnesium chloride hexahydrate

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Fezei Radouanne

2012-01-01

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

Calcium phosphate stabilization of fly ash with chloride extraction.

Science.gov (United States)

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.

Corrosion of Carbon Steel and Corrosion-Resistant Rebars in Concrete Structures Under Chloride Ion Attack

Science.gov (United States)

Mohamed, Nedal; Boulfiza, Mohamed; Evitts, Richard

2013-03-01

Corrosion of reinforced concrete is the most challenging durability problem that threatens reinforced concrete structures, especially structures that are subject to severe environmental conditions (i.e., highway bridges, marine structures, etc.). Corrosion of reinforcing steel leads to cracking and spalling of the concrete cover and billions of dollars are spent every year on repairing such damaged structures. New types of reinforcements have been developed to avoid these high-cost repairs. Thus, it is important to study the corrosion behavior of these new types of reinforcements and compare them to the traditional carbon steel reinforcements. This study aimed at characterizing the corrosion behavior of three competing reinforcing steels; conventional carbon steel, micro-composite steel (MMFX-2) and 316LN stainless steel, through experiments in carbonated and non-carbonated concrete exposed to chloride-laden environments. Synthetic pore water solutions have been used to simulate both cases of sound and carbonated concrete under chloride ions attack. A three-electrode corrosion cell is used for determining the corrosion characteristics and rates. Multiple electrochemical techniques were applied using a Gamry PC4™ potentiostat manufactured by Gamry Instruments (Warminster, PA). DC corrosion measurements were applied on samples subjected to fixed chloride concentration in the solution.

Determination of the formation constant for the inclusion complex between Lanthanide ions and Dansyl chloride derivative by fluorescence spectroscopy: Theoretical and experimental investigation

Science.gov (United States)

Riahi, Siavash; Ganjali, Mohammad Reza; Hariri, Maryam; Abdolahzadeh, Shaghayegh; Norouzi, Parviz

2009-09-01

In this paper, a sensitive, easy, efficient, and suitable method for the calculation of Kf values of complexation between one derivative of Dansyl chloride [5-(dimethylamino) naphthalene-1-sulfonyl 4-phenylsemicarbazide] (DMNP) and Lanthanide(III) (Ln) ions is proposed, using both spectrofluorometric and spectrophotometric methods. Determination of Kf showed that DMNP was mostly selective towards the erbium (III) ion. The validity of the method was also confirmed calculating the Stern-Volmer fluorescence quenching constants ( Ksv) that resulted in the same consequence, obtained by calculating the Kf of complexation values. In addition, the UV-vis spectroscopy was applied for the determination of Kf only for the Ln ions that had interactions with DMNP. Finally, the DFT studies were done on Er 3+ and the DMNP complex for distinguishing the active sites and estimating the pair wise interaction energy. It can be concluded that this derivative of Dansyl chloride with inherent high fluorescence intensity is a suitable reagent for the selective determination of the Er 3+ ion which can be used in constructing selective Er 3+ sensors.

Poly (Vinyl Chloride Based Ion Selective Electrode for Determination of Zr (IV Ions Based on 2, 6-Dibenzylidenecyclohexanone

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Syed A. Nabi

2008-08-01

Full Text Available A selective poly (vinyl chloride-based membrane sensor using 2,6-Dibenzylidenecyclohexanone as an ionophore have been prepared and explored as Zr (IV selective electrode. The sensitivity, working range and response time shows a significant dependence on the concentration of ionophore. The electrode prepared with 100 mg of PVC, 10 mg of ionophore and 5 ml of dibutylthylate shows the best performance. The electrode works well in the concentration range of 1×10-1-5×10-5 with a nerstian slope 55±2 eV and response time of 18 seconds. The sensor works well over the pH range 3-6. The sensor can be used for the period of over 1 month with out deviation in response characteristics. The selectivity of the electrode was studied and it was found that the electrode exhibited good selectivity for zirconium (IV over some alkaline earth metal ions. The electrode was also used as indicator electrode for potentiometeric titration of Zr (IV ions against EDTA solution.

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

Energy Technology Data Exchange (ETDEWEB)

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

2000-06-30

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

Poly(vinyl chloride) membrane alkali metal ion-selective electrodes based on crystalline synthetic zeolite of the Faujasite type

International Nuclear Information System (INIS)

Aghai, H.; Giahi, M.; Arvand Barmehi, M.

2002-01-01

Potentiometric electrodes based on the incorporation of zeolite particle in to poly (vinyl chloride) (pvc) membranes are described. The electrodes characteristics are evaluated regarding the response towards alkali ions. Pvc membranes plasticised with dibutyl phthalate and without lipophilic additives (co-exchanger) were used throughout this study. The electrode exhibits a Nernst ion response over the alkali metal cations concentration a range of 1.0x10 - 4 - 1.0 x 10 1 M with a slop of 57.0 ± 0.9 mV per decade of concentration a working ph range (3.0- 9.0) and a fast response time (≤15 c). The selective coefficients for cesium ion as test species with respect to alkaline earth, ammonium and some heavy metal ions were determined. Zeolite-PVC electrodes were applied to the determination of ionic surfactant

Individual and combined effects of chloride, sulfate, and magnesium ions on hydrated Portland-cement paste

International Nuclear Information System (INIS)

Poole, T.S.; Wakeley, L.D.; Young, C.L.

1994-03-01

Ground water with a high concentration of magnesium ion is known to cause deterioration to portland cement concretes. A proposed mechanism for this deterioration process published previously involves an approximate 1:1 replacement of Ca ions by Mg ions in the crystalline phases of hydrated cement. The current study was undertaken to determine which ions, among magnesium, chloride, and sulfate, cause deterioration; whether their deleterious action is individual or interdependent; and to relate this mechanism of deterioration to the outlook for a 100-yr service life of concretes used in mass placements at the Waste Isolation Pilot Plant. Loss of Ca ion by cement pastes was found to be strongly related to the concentration of Mg ion in simulated ground-water solutions in which the paste samples were aged. This was true of both salt- containing and conventional cement pastes. No other ion in the solutions exerted a strong effect on Ca loss. Ca ion left first from calcium hydroxide in the pastes, depleting all calcium hydroxide by 60 days. Some calcium silicate hydrate remained even after 90 days in the solutions with the highest concentration of Mg ion, while the paste samples deteriorated noticeably. The results indicated a mechanism that involves dissolution of Ca phases and transport of Ca ions to the surface of the sample, followed by formation of Mg-bearing phases at this reaction surface rather than directly by substitution within the microstructure of hydrated cement. Given that calcium hydroxide and calcium silicate hydrate are the principal strength-giving phases of hydrated cement, this mechanism indicates the likelihood of significant loss of integrity of a concrete exposed to Mg-bearing ground water at the WIPP. The rate of deterioration ultimately will depend on Mg-ion concentration, the microstructure materials of the concrete exposed to that groundwater, and the availability of brine

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

International Nuclear Information System (INIS)

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

2008-01-01

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

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

Science.gov (United States)

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

2011-01-01

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

Sugar-metal ion interactions: The coordination behavior of cesium ion with lactose, D-arabinose and L-arabinose

Science.gov (United States)

Jiang, Ye; Xue, Junhui; Wen, Xiaodong; Zhai, Yanjun; Yang, Limin; Xu, Yizhuang; Zhao, Guozhong; Kou, Kuan; Liu, Kexin; Chen, Jia'er; Wu, Jinguang

2016-04-01

The novel cesium chloride-lactose complex (CsCl·C12H22O10 (Cs-Lac), cesium chloride-D-arabinose and L-arabinose complexes (CsCl·C5H10O5, Cs-D-Ara and Cs-L-Ara) have been synthesized and characterized using X-ray diffraction, FTIR, FIR, THz and Raman spectroscopies. Cs+ is 9-coordinated to two chloride ions and seven hydroxyl groups from five lactose molecules in Cs-Lac. In the structures of CsCl-D-arabinose and CsCl-L-arabinose complexes, two kinds of Cs+ ions coexist in the structures. Cs1 is 10-coordinated with two chloride ions and eight hydroxyl groups from five arabinose molecule; Cs2 is 9-coordinated to three chloride ions and six hydroxyl groups from five arabinose molecules. Two coordination modes of arabinose coexist in the structures. α-D-arabinopyranose and α-L-arabinopyranose appear in the structures of Cs-D-Ara and Cs-L-Ara complexes. FTIR and Raman results indicate variations of hydrogen bonds and the conformation of the ligands after complexation. FIR and THz spectra also confirm the formation of Cs-complexes. Crystal structure, FTIR, FIR, THz and Raman spectra provide detailed information on the structure and coordination of hydroxyl groups to metal ions in the cesium chloride-lactose, cesium chloride-D- and L-arabinose complexes.

Influence of chloride admixtures on cement matrix durability

International Nuclear Information System (INIS)

Sheikh, I.A.; Zamorani, E.; Serrini, G.

1989-01-01

The influence of various inorganic salts, as chloride admixtures to Portland cement, on the mechanical properties and the durability of the matrix has been studied. The salts used in this study are chromium, nickel and cadmium chlorides. Improved compressive strength values are obtained which have been correlated to the stable metal hydroxide formation in high pH environment. Under static water conditions at 50 0 C, hydrolyzed chloride ions exhibit adverse effects on the matrix durability through rapid release of calcium as calcium chloride in the initial period of leaching. On the contrary, enhanced matrix durability is obtained on long term leaching in the case of cement containing chromium chloride

GABA, depressants and chloride ions affect the rate of dissociation of 35S-t-butylbicyclophosphorothionate binding

International Nuclear Information System (INIS)

Maksay, G.; Ticku, M.K.

1985-01-01

The dissociation of 35 S-TBPS was studied from binding sites of rat cerebral cortex. Monophasic dissociation plots became polyphasic and accelerated in the presence of micromolar concentrations of GABA suggesting the involvement of low (or super-low) affinity GABA receptors. The presence of the depressants etazolate, R(-)MPPB and ethanol resulted in similarly accelerated dissociation patterns. In contrast, the convulsants S(+)MPPB and pentamethylenetetrazol did not significantly affect the dissociation of TBPS. Dissociation initiated by dilution was not affected either by an excess of picrotoxin or by varying the equilibrium occupancy of the TBPS sites. These findings rule out the possibility of a kinetic cooperativity for the binding of convulsants. The removal of chloride ions also enhanced the rate of TBPS dissociation. Kinetic heterogeneity of the TBPS binding sites can be interpreted with allosteric interactions mediated by various sites at the GABA receptor complex coupled to different states of the chloride ionophore. 15 references, 3 figures, 1 table

Pitting corrosion resistance of a novel duplex alloy steel in alkali-activated slag extract in the presence of chloride ions

Science.gov (United States)

Shi, Jin-jie; Ming, Jing; Liu, Xin

2017-10-01

In this study, two types of reinforcing steels (conventional low-carbon steel and a novel duplex alloy steel with Cr and Mo) were exposed to chloride-contaminated extract solutions (ordinary Portland cement (OPC) extract and alkali-activated slag (AAS) extract) to investigate their pitting corrosion resistance. The results confirm that the pitting corrosion resistance of the alloy steel is much higher than that of the low-carbon steel in both extract solutions with various NaCl concentrations. Moreover, for each type of steel, the AAS extract contributes to a higher pitting corrosion resistance compared with the OPC extract in the presence of chloride ions, likely because of the formation of flocculent precipitates on the steel surface.

Sulfobacillus thermosulfidooxidans strain Cutipay enhances chalcopyrite bioleaching under moderate thermophilic conditions in the presence of chloride ion.

Science.gov (United States)

Bobadilla-Fazzini, Roberto A; Cortés, Maria Paz; Maass, Alejandro; Parada, Pilar

2014-12-01

Currently more than 90% of the world's copper is obtained through sulfide mineral processing. Among the copper sulfides, chalcopyrite is the most abundant and therefore economically relevant. However, primary copper sulfide bioleaching is restricted due to high ionic strength raffinate solutions and particularly chloride coming from the dissolution of ores. In this work we describe the chalcopyrite bioleaching capacity of Sulfobacillus thermosulfidooxidans strain Cutipay (DSM 27601) previously described at the genomic level (Travisany et al. (2012) Draft genome sequence of the Sulfobacillus thermosulfidooxidans Cutipay strain, an indigenous bacterium isolated from a naturally extreme mining environment in Northern Chile. J Bacteriol 194:6327-6328). Bioleaching assays with the mixotrophic strain Cutipay showed a strong increase in copper recovery from chalcopyrite concentrate at 50°C in the presence of chloride ion, a relevant inhibitory element present in copper bioleaching processes. Compared to the abiotic control and a test with Sulfobacillus acidophilus DSM 10332, strain Cutipay showed an increase of 42 and 69% in copper recovery, respectively, demonstrating its high potential for chalcopyrite bioleaching. Moreover, a genomic comparison highlights the presence of the 2-Haloacid dehalogenase predicted-protein related to a potential new mechanism of chloride resistance in acidophiles. This novel and industrially applicable strain is under patent application CL 2013-03335.

Suppression of adenosine-activated chloride transport by ethanol in airway epithelia.

Directory of Open Access Journals (Sweden)

Sammeta V Raju

Full Text Available Alcohol abuse is associated with increased lung infections. Molecular understanding of the underlying mechanisms is not complete. Airway epithelial ion transport regulates the homeostasis of airway surface liquid, essential for airway mucosal immunity and lung host defense. Here, air-liquid interface cultures of Calu-3 epithelial cells were basolaterally exposed to physiologically relevant concentrations of ethanol (0, 25, 50 and 100 mM for 24 hours and adenosine-stimulated ion transport was measured by Ussing chamber. The ethanol exposure reduced the epithelial short-circuit currents (I(SC in a dose-dependent manner. The ion currents activated by adenosine were chloride conductance mediated by cystic fibrosis transmembrane conductance regulator (CFTR, a cAMP-activated chloride channel. Alloxazine, a specific inhibitor for A(2B adenosine receptor (A(2BAR, largely abolished the adenosine-stimulated chloride transport, suggesting that A(2BAR is a major receptor responsible for regulating the chloride transport of the cells. Ethanol significantly reduced intracellular cAMP production upon adenosine stimulation. Moreover, ethanol-suppression of the chloride secretion was able to be restored by cAMP analogs or by inhibitors to block cAMP degradation. These results imply that ethanol exposure dysregulates CFTR-mediated chloride transport in airways by suppression of adenosine-A(2BAR-cAMP signaling pathway, which might contribute to alcohol-associated lung infections.

Osmoregulated Chloride Currents in Hemocytes from Mytilus galloprovincialis.

Directory of Open Access Journals (Sweden)

Monica Bregante

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

Anomalous surface behavior of hydrated guanidinium ions due to ion pairing

Science.gov (United States)

Ekholm, Victor; Vazdar, Mario; Mason, Philip E.; Bialik, Erik; Walz, Marie-Madeleine; Öhrwall, Gunnar; Werner, Josephina; Rubensson, Jan-Erik; Jungwirth, Pavel; Björneholm, Olle

2018-04-01

Surface affinity of aqueous guanidinium chloride (GdmCl) is compared to that of aqueous tetrapropylammonium chloride (TPACl) upon addition of sodium chloride (NaCl) or disodium sulfate (Na2SO4). The experimental results have been acquired using the surface sensitive technique X-ray photoelectron spectroscopy on a liquid jet. Molecular dynamics simulations have been used to produce radial distribution functions and surface density plots. The surface affinities of both TPA+ and Gdm+ increase upon adding NaCl to the solution. With the addition of Na2SO4, the surface affinity of TPA+ increases, while that of Gdm+ decreases. From the results of MD simulations it is seen that Gdm+ and SO4 2 - ions form pairs. This finding can be used to explain the decreased surface affinity of Gdm+ when co-dissolved with SO4 2 - ions. Since SO4 2 - ions avoid the surface due to the double charge and strong water interaction, the Gdm+-SO4 2 - ion pair resides deeper in the solutions' bulk than the Gdm+ ions. Since TPA+ does not form ion pairs with SO4 2 -, the TPA+ ions are instead enriched at the surface.

In-situ complex with by-product HCl and release chloride ions to dissolve aramid.

Science.gov (United States)

Dai, Yu; Cheng, Zheng; Yuan, Yihao; Meng, Chenbo; Qin, Jiaqiang; Liu, Xiangyang

2018-06-20

Because of the strong hydrogen-bond interaction among macromolecular chains, addition of chloride salts is generally needed to offer Cl- ions for dissolution of aromatic polyamides. In this paper, poly-(benzimidazole-terephthalamide) which complexed with by-product HCl during polymerization (PABI-HCl) was prepared and imidazole compound as cosolvent was added into dimethylacetamide (DMAc) to dissolve PABI-HCl. Due to stronger affinity to protons, imidazole compound could in-situ complex with HCl of PABI-HCl and form imidazolium hydrochloride. Then imidazolium hydrochloride would ionize and produce much free Cl- ions which acted as stronger hydrogen-bond acceptor to disrupt interaction among macromolecular chains. As a result, solubility of PABI-HCl in DMAc was improved significantly in existence of small amount of imidazole compound. Moreover, DMAc-imidazole mixture was utlized for synthesis of different kinds of aramids and no precipitation was observed with progress of the reaction. So the mixture was suitable to be utlized as solvent for polymerization of aramid. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Specific ion effects on membrane potential and the permselectivity of ion exchange membranes.

Science.gov (United States)

Geise, Geoffrey M; Cassady, Harrison J; Paul, Donald R; Logan, Bruce E; Hickner, Michael A

2014-10-21

Membrane potential and permselectivity are critical parameters for a variety of electrochemically-driven separation and energy technologies. An electric potential is developed when a membrane separates electrolyte solutions of different concentrations, and a permselective membrane allows specific species to be transported while restricting the passage of other species. Ion exchange membranes are commonly used in applications that require advanced ionic electrolytes and span technologies such as alkaline batteries to ammonium bicarbonate reverse electrodialysis, but membranes are often only characterized in sodium chloride solutions. Our goal in this work was to better understand membrane behaviour in aqueous ammonium bicarbonate, which is of interest for closed-loop energy generation processes. Here we characterized the permselectivity of four commercial ion exchange membranes in aqueous solutions of sodium chloride, ammonium chloride, sodium bicarbonate, and ammonium bicarbonate. This stepwise approach, using four different ions in aqueous solution, was used to better understand how these specific ions affect ion transport in ion exchange membranes. Characterization of cation and anion exchange membrane permselectivity, using these ions, is discussed from the perspective of the difference in the physical chemistry of the hydrated ions, along with an accompanying re-derivation and examination of the basic equations that describe membrane potential. In general, permselectivity was highest in sodium chloride and lowest in ammonium bicarbonate solutions, and the nature of both the counter- and co-ions appeared to influence measured permselectivity. The counter-ion type influences the binding affinity between counter-ions and polymer fixed charge groups, and higher binding affinity between fixed charge sites and counter-ions within the membrane decreases the effective membrane charge density. As a result permselectivity decreases. The charge density and polarizability

Crevice corrosion of alloy 22 in fluoride and chloride containing solutions

International Nuclear Information System (INIS)

Carranza, Ricardo M.; Rodriguez, Martin A.

2005-01-01

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

Recovery of Lithium from Geothermal Brine with Lithium-Aluminum Layered Double Hydroxide Chloride Sorbents.

Science.gov (United States)

Paranthaman, Mariappan Parans; Li, Ling; Luo, Jiaqi; Hoke, Thomas; Ucar, Huseyin; Moyer, Bruce A; Harrison, Stephen

2017-11-21

We report a three-stage bench-scale column extraction process to selectively extract lithium chloride from geothermal brine. The goal of this research is to develop materials and processing technologies to improve the economics of lithium extraction and production from naturally occurring geothermal and other brines for energy storage applications. A novel sorbent, lithium aluminum layered double hydroxide chloride (LDH), is synthesized and characterized with X-ray powder diffraction, scanning electron microscopy, inductively coupled plasma optical emission spectrometry (ICP-OES), and thermogravimetric analysis. Each cycle of the column extraction process consists of three steps: (1) loading the sorbent with lithium chloride from brine; (2) intermediate washing to remove unwanted ions; (3) final washing for unloading the lithium chloride ions. Our experimental analysis of eluate vs feed concentrations of Li and competing ions demonstrates that our optimized sorbents can achieve a recovery efficiency of ∼91% and possess excellent Li apparent selectivity of 47.8 compared to Na ions and 212 compared to K ions, respectively in the brine. The present work demonstrates that LDH is an effective sorbent for selective extraction of lithium from brines, thus offering the possibility of effective application of lithium salts in lithium-ion batteries leading to a fundamental shift in the lithium supply chain.

cis-Dichloridobis(1,10-phenanthrolinechromium(III chloride

Directory of Open Access Journals (Sweden)

Xiaoli Gao

2011-02-01

Full Text Available In the title complex, [CrCl2(C12H8N22]Cl, the CrIII ion is situated on a twofold rotation axis and displays a slightly distorted octahedral CrCl2N4 coordination geometry. The Cr environment is composed of a cis arrangement of two 1,10-phenanthroline and two chloride ligands. The chloride counter-anion exhibits half-occupation and is equally disordered over two positions.

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

International Nuclear Information System (INIS)

Gray, L.W.

1978-10-01

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

Photonic crystal fiber based chloride chemical sensors for corrosion monitoring

Science.gov (United States)

Wei, Heming; Tao, Chuanyi; Krishnaswamy, Sridhar

2016-04-01

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

Corrosion behaviour of a stream generator tube material in simulated steam generator feedwater containing chlorides and sulphates

Energy Technology Data Exchange (ETDEWEB)

Bojinov, M.; Kinnunen, P.; Laitinen, T.; Maekelae, K.; Saario, T.; Sirkiae, P.; Yliniemi, K. [VTT Manufacturing Technology, Espoo (Finland); Buddas, T.; Halin, M.; Tompuri, K. [Fortum Power and Heat Oy, Loviisa Power Plant (Finland)

2002-07-01

The goal of the present work has been to assess the effect of relatively high concentrations of anionic impurities (Cl{sup -}, SO{sub 4}{sup 2-}) on the corrosion behaviour of Ti-stabilised stainless steel SG tubes in simulated steam generator feed-water. The main observations of this work can be summarised as follows: Sulphate ions seem to be more aggressive than chloride ions towards the primary passive film on 08X18H10T stainless steel. The results may indicate that it is more important to have a low concentration of sulphate ions than of chloride ions in secondary side water when the effects of chemical conditions on tube degradation are considered. The presence of chloride ions seems to weaken the detrimental effect of sulphate ions on the stability of oxide films growing on 08X18H10T stainless steel. No localised corrosion features of 08X18H10T stainless steel were detected in the voltammetric and impedance measurements in solutions containing up to 5000 ppb sulphates, chlorides or both of the anions. (authors)

Corrosion behaviour of a stream generator tube material in simulated steam generator feedwater containing chlorides and sulphates

International Nuclear Information System (INIS)

Bojinov, M.; Kinnunen, P.; Laitinen, T.; Maekelae, K.; Saario, T.; Sirkiae, P.; Yliniemi, K.; Buddas, T.; Halin, M.; Tompuri, K.

2002-01-01

The goal of the present work has been to assess the effect of relatively high concentrations of anionic impurities (Cl - , SO 4 2- ) on the corrosion behaviour of Ti-stabilised stainless steel SG tubes in simulated steam generator feed-water. The main observations of this work can be summarised as follows: Sulphate ions seem to be more aggressive than chloride ions towards the primary passive film on 08X18H10T stainless steel. The results may indicate that it is more important to have a low concentration of sulphate ions than of chloride ions in secondary side water when the effects of chemical conditions on tube degradation are considered. The presence of chloride ions seems to weaken the detrimental effect of sulphate ions on the stability of oxide films growing on 08X18H10T stainless steel. No localised corrosion features of 08X18H10T stainless steel were detected in the voltammetric and impedance measurements in solutions containing up to 5000 ppb sulphates, chlorides or both of the anions. (authors)

An experiment on multibubble sonoluminescence spectra in sodium chloride solution

Institute of Scientific and Technical Information of China (English)

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

2008-01-01

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

Optical, thermal and magnetic studies of pure and cobalt chloride doped L-alanine cadmium chloride

Energy Technology Data Exchange (ETDEWEB)

Benila, B.S., E-mail: benjane.benila@gmail.com [Department of Physics and Research Centre, Scott Christian College (Autonomous), Nagercoil 629 003 (India); Bright, K.C. [Department of Physics, St. John' s College, Anchal, Kollam 691 306 (India); Delphine, S. Mary [Department of Physics, Holy Cross College (Autonomous), Nagercoil 629 004 (India); Shabu, R. [Department of Physics and Research Centre, Scott Christian College (Autonomous), Nagercoil 629 003 (India)

2017-03-15

Single crystals of L-alanine cadmium chloride (LACC) and cobalt chloride (Co{sup 2+}) doped LACC have been grown by the slow evaporation solution growth technique. The grown crystals were subjected to various characterizations such as powder XRD, SXRD, FTIR, UV–vis, EDAX, TG/DTA, VSM, Dielectric and Second Harmonic Generation (SHG) measurements. The lattice parameters of the grown crystals were determined by single crystal X-ray analysis. EDAX analysis confirms the presence of Co{sup 2+} ion in the host material. The functional group and optical behavior of the crystals were identified from FTIR and UV-vis spectrum analysis. Electrical parameters such as dielectric constant, dielectric loss have been studied. The thermal stability of the compound was found out using TGA/DTA analysis. Second Harmonic Generation of the samples was confirmed by Kurtz-Perry powder technique. Magnetic properties of the crystals studied by VSM were also reported. The encouraging results show that the cobalt chloride doped LACC crystals have greater potential applications in optical devices. - Graphical abstract: Fig (a) and (b) shows the transparent, stable single crystals of pure and doped crystals were obtained using slow evaporation technique. The sizes of pure and doped crystals are 20×9×2 mm{sup 3} and 18×15×1 mm{sup 3} respectively. Fig (c) is the Hysteresis loop traced at room temperature for the pure and doped crystals explains the soft ferromagnetic nature of the doped crystal. The provision for changing the value of coercivity can be used for security, switching and sensing applications. - Highlights: • Defect free crystals of pure and Co{sup 2+} ion doped L-alanine cadmium chloride were grown. • The optical, dielectric and magnetic properties of pure crystals were enhanced by adding Co{sup 2+} ion. • High optical transmittance was obtained in the entire visible and IR region. • Addition of dopant to the pure crystal altered the coercivity. • Low dielectric

The medical sodium chloride

International Nuclear Information System (INIS)

Mirsaidov, U.M.

2002-01-01

In the institute was investigated the chemical composition of rock salt of some deposits of Tajikistan and was show the presence in it admixture of ions of Ca 2 + , Mg 2 + a nd SO 2 - a nd absence of heavy metals, ammonium salts, iron, potassium and arsenic. Was elaborated the fundamental instrument-technologic scheme of sodium chloride receiving

Specific ion effects on membrane potential and the permselectivity of ion exchange membranes

KAUST Repository

Geise, Geoffrey M.

2014-08-26

© the Partner Organisations 2014. Membrane potential and permselectivity are critical parameters for a variety of electrochemically-driven separation and energy technologies. An electric potential is developed when a membrane separates electrolyte solutions of different concentrations, and a permselective membrane allows specific species to be transported while restricting the passage of other species. Ion exchange membranes are commonly used in applications that require advanced ionic electrolytes and span technologies such as alkaline batteries to ammonium bicarbonate reverse electrodialysis, but membranes are often only characterized in sodium chloride solutions. Our goal in this work was to better understand membrane behaviour in aqueous ammonium bicarbonate, which is of interest for closed-loop energy generation processes. Here we characterized the permselectivity of four commercial ion exchange membranes in aqueous solutions of sodium chloride, ammonium chloride, sodium bicarbonate, and ammonium bicarbonate. This stepwise approach, using four different ions in aqueous solution, was used to better understand how these specific ions affect ion transport in ion exchange membranes. Characterization of cation and anion exchange membrane permselectivity, using these ions, is discussed from the perspective of the difference in the physical chemistry of the hydrated ions, along with an accompanying re-derivation and examination of the basic equations that describe membrane potential. In general, permselectivity was highest in sodium chloride and lowest in ammonium bicarbonate solutions, and the nature of both the counter- and co-ions appeared to influence measured permselectivity. The counter-ion type influences the binding affinity between counter-ions and polymer fixed charge groups, and higher binding affinity between fixed charge sites and counter-ions within the membrane decreases the effective membrane charge density. As a result permselectivity decreases. The

Chloride sensing by WNK1 kinase involves inhibition of autophosphorylation

Science.gov (United States)

Piala, Alexander T.; Moon, Thomas M.; Akella, Radha; He, Haixia; Cobb, Melanie H.; Goldsmith, Elizabeth J.

2014-01-01

WNK1 [with no lysine (K)] is a serine-threonine kinase associated with a form of familial hypertension. WNK1 is at the top of a kinase cascade leading to phosphorylation of several cotransporters, in particular those transporting sodium, potassium, and chloride (NKCC), sodium and chloride (NCC), and potassium and chloride (KCC). The responsiveness of NKCC, NCC, and KCC to changes in extracellular chloride parallels their phosphorylation state, provoking the proposal that these transporters are controlled by a chloride-sensitive protein kinase. Here, we found that chloride stabilizes the inactive conformation of WNK1, preventing kinase autophosphorylation and activation. Crystallographic studies of inactive WNK1 in the presence of chloride revealed that chloride binds directly to the catalytic site, providing a basis for the unique position of the catalytic lysine. Mutagenesis of the chloride binding site rendered the kinase less sensitive to inhibition of autophosphorylation by chloride, validating the binding site. Thus, these data suggest that WNK1 functions as a chloride sensor through direct binding of a regulatory chloride ion to the active site, which inhibits autophosphorylation. PMID:24803536

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

International Nuclear Information System (INIS)

Borhade, A.V.

2000-01-01

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

Synthesis, spectroscopic and thermal studies of the copper(II) aspartame chloride complex

Science.gov (United States)

Çakır, S.; Coşkun, E.; Naumov, P.; Biçer, E.; Bulut, İ.; İçbudak, H.; Çakır, O.

2002-08-01

Aspartame adduct of copper(II) chloride Cu(Asp) 2Cl 2·2H 2O (Asp=aspartame) is synthesized and characterized by elemental analysis, FT IR, UV/vis, ESR spectroscopies, TG, DTG, DTA measurements and molecular mechanics calculations. Aqueous solution of the green solid absorbs strongly at 774 and 367 nm. According to the FT IR spectra, the aspartame moiety coordinates to the copper(II) ion via its carboxylate ends, whereas the ammonium terminal groups give rise to hydrogen bonding network with the water, the chloride ions or neighboring carboxylate groups. The results suggest tetragonally distorted octahedral environment of the copper ions.

Analysis of the theoretical model of the rapid chloride migration test

NARCIS (Netherlands)

Spiesz, P.; Brouwers, H.J.H.; Fisher, Gregor; Geiker, Metta Rica; Hededal, Ole; Ottosen, Lisbeth M.; Stang, Henrik

2010-01-01

Chloride ion diffusion coefficient in concrete is estimated very often by using electromigration tests, among which the Rapid Chloride Migration (RCM) test is becoming more and more popular. Nevertheless, this test receives much criticism due to lacks in its scientific background. In this paper the

Potentiometric study of cadmium (2) complexing with chloride-ions in aqueous solutions of Mg(ClO/sub 4/, Cl)/sub 2/

Energy Technology Data Exchange (ETDEWEB)

Prokuev, V A; Belousov, E A

1985-05-01

By the method of potentiometric titration using cadmium amalgam electrode at ionic forces 1.0; 2.0; 3.0; 4.5; 6.0; 7.5 and 9.0 of (Mg(ClO/sub 4/)/sub 2/ general constants of cadmium chloride compleses stability are determined. By the Vasiliev extrapolation equation thermodynamic constants of CdClsub(n)sup(2-n) ion formation, where n=1-3 are evaluated.

Study of electrochemical behaviour of tantalum in molten alkali metal chlorides

International Nuclear Information System (INIS)

Bajmakov, A.N.; Ezrokhina, A.M.; Sashinina, O.A.; Shkol'nikov, S.N.

1985-01-01

Equilibrium potentials of metallic tantalum in the melt TaCl 5 +KCl-NaCl are studied. Are average degree of tantalum ion oxidation, which are in equilibrium with metallic tantalum, is determined. Anodic behaviour of tantalum in equimolar mixture of potassium and sodium chlorides with Ta and F ion additions is considered. An average degree of oxidation of Ta ions, which transfer into the melt, depending on current density, is determined. It is established that tantalum is dissolved in the regime of diffusional kinetics. It is shown that tantalum corrodes in equimolar mixture of potassium and sodiUm chlorides, at that, corrosion rate increases with introdUction of Ta and F ions into solution. The corrosion is of electrochemical nature and it proceeds in the regime of diffusional kinetics

Ion Selectivity Mechanism in a Bacterial Pentameric Ligand-Gated Ion Channel

International Nuclear Information System (INIS)

Wang, Hailong; Cheng, Xiaolin

2011-01-01

The proton-gated ion channel from Gloeobacter violaceus (GLIC) is a prokaryotic homolog of the eukaryotic nicotinic acetylcholine receptor (nAChR) that responds to the binding of neurotransmitter acetylcholine and mediates fast signal transmission. Recent emergence of a high resolution crystal structure of GLIC captured in a potentially open state allowed detailed, atomic-level insight into ion conduction and selectivity mechanisms in these channels. Herein, we have examined the barriers to ion conduction and origins of ion selectivity in the GLIC channel by the construction of potential of mean force (PMF) profiles for sodium and chloride ions inside the transmembrane region. Our calculations reveal that the GLIC channel is open for a sodium ion to transport, but presents a ∼10 kcal/mol free energy barrier for a chloride ion, which arises primarily from the unfavorable interactions with a ring of negatively charged glutamate residues (E-2) at the intracellular end and a ring of hydrophobic residues (I9) in the middle of the transmembrane domain. Our collective findings further suggest that the charge selection mechanism can, to a large extent, be attributed to the narrow intracellular end and a ring of glutamate residues in this position their strong negative electrostatics and ability to bind cations. By contrast, E19 at the extracellular entrance only plays a minor role in ion selectivity of GLIC. In addition to electrostatics, both ion hydration and protein dynamics are found to be crucial for ion conduction as well, which explains why a chloride ion experiences a much greater barrier than a sodium ion in the hydrophobic region of the pore.

Prediction of the Service Life of a Reinforced Concrete Column under Chloride Environment

Directory of Open Access Journals (Sweden)

Mohammad K. Alkam

2015-01-01

Full Text Available In the present investigation, service life of a reinforced concrete column exposed to chloride environment has been predicted. This study has been based on numerical simulation of chloride ion diffusion in a concrete column during its anticipated life span. The simulation process has included the concrete cover replacement whenever chloride ion concentration has reached the critical threshold value at the reinforcement surface. Repair scheduling of the concrete column under consideration has been discussed. Effects of the concrete cover thickness and the water cement ratio on the service life of the concrete column at hand have been presented. A new approach for arranging locations of reinforcement steel bars has been introduced. This approach is intended to prolong the service life of the concrete column under consideration against chloride induced corrosion.

Algunas determinaciones del pregnandiol urinario en el aborto amenazante

Directory of Open Access Journals (Sweden)

Eudoro Castillo Vega

1956-07-01

Full Text Available El presente trabajo tiene por objeto hacer algunas "determinaciones del pregnandiol urinario en enfermas con síntomas evidentes de aborto amenazante", o bien, en enfermas en cuya historia anamnésica se encuentre el antecedente de uno o más abortos anteriores, así como también de partos prematuros y que, ni en los primeros ni en los últimos se haya encontrado una causa bien determinada. En lo posible, se han escogido pacientes con antecedente Serológico Negativo y de constitución topográfica anatómica, en cuanto a pelvis se refiere, normales. Es de lógica que, a una enferma con una desviación uterina o con un tumor pélvico, no se puede achacar el aborto a deficiencia de Progesterona o de cualquiera otra hormona, pues la causa es verdaderamente objetiva.

Mapping the Galvanic Corrosion of Three Coupled Metal Alloys Using Coupled Multielectrode Array: Influence of Chloride Ion Concentration

Directory of Open Access Journals (Sweden)

Hong Ju

2018-04-01

Full Text Available The galvanic corrosion behavior of three metal alloys commonly used in water desalination plants was investigated using coupled multielectrode arrays consisting of aluminum-brass (HAl77-2, titanium alloy (TA2, and 316L stainless steel (316L SS. The three electrode types were coupled galvanically and arranged in different geometric configurations. Their corrosion behavior was characterized as a function of the chloride concentration. The potential and current distributions of the three-electrode coupling systems display electrochemical inhomogeneity. Generally, the aluminum-brass wires are anodic versus the titanium alloy and stainless steel. The titanium alloy acts as a primary cathode, and the 316L SS acts as a secondary cathode. The corrosion rate of aluminum-brass depends on the concentration of chloride ion, with a maximum corrosion rate at a chloride concentration of 2.3 wt %. In terms of geometrical arrangements, when the anodic HAl77-2 wires are located on the edge and are connected to the 316L SS wires in the coupling system, the main anodic area enlarges, especially in the area adjacent to the 316L SS wires. When the HAl77-2 wires are located between (in the middle of the two other types of wires, the corrosion rates are higher than the corrosion rates observed from the other two geometrical arrangements.

Mapping the Galvanic Corrosion of Three Coupled Metal Alloys Using Coupled Multielectrode Array: Influence of Chloride Ion Concentration.

Science.gov (United States)

Ju, Hong; Duan, JinZhuo; Yang, Yuanfeng; Cao, Ning; Li, Yan

2018-04-20

The galvanic corrosion behavior of three metal alloys commonly used in water desalination plants was investigated using coupled multielectrode arrays consisting of aluminum-brass (HAl77-2), titanium alloy (TA2), and 316L stainless steel (316L SS). The three electrode types were coupled galvanically and arranged in different geometric configurations. Their corrosion behavior was characterized as a function of the chloride concentration. The potential and current distributions of the three-electrode coupling systems display electrochemical inhomogeneity. Generally, the aluminum-brass wires are anodic versus the titanium alloy and stainless steel. The titanium alloy acts as a primary cathode, and the 316L SS acts as a secondary cathode. The corrosion rate of aluminum-brass depends on the concentration of chloride ion, with a maximum corrosion rate at a chloride concentration of 2.3 wt %. In terms of geometrical arrangements, when the anodic HAl77-2 wires are located on the edge and are connected to the 316L SS wires in the coupling system, the main anodic area enlarges, especially in the area adjacent to the 316L SS wires. When the HAl77-2 wires are located between (in the middle of) the two other types of wires, the corrosion rates are higher than the corrosion rates observed from the other two geometrical arrangements.

Ion chromatography for the precise analysis of chloride and sodium in sweat for the diagnosis of cystic fibrosis.

Science.gov (United States)

Doorn, J; Storteboom, T T R; Mulder, A M; de Jong, W H A; Rottier, B L; Kema, I P

2015-07-01

Measurement of chloride in sweat is an essential part of the diagnostic algorithm for cystic fibrosis. The lack in sensitivity and reproducibility of current methods led us to develop an ion chromatography/high-performance liquid chromatography (IC/HPLC) method, suitable for the analysis of both chloride and sodium in small volumes of sweat. Precision, linearity and limit of detection of an in-house developed IC/HPLC method were established. Method comparison between the newly developed IC/HPLC method and the traditional Chlorocounter was performed, and trueness was determined using Passing Bablok method comparison with external quality assurance material (Royal College of Pathologists of Australasia). Precision and linearity fulfill criteria as established by UK guidelines are comparable with inductively coupled plasma-mass spectrometry methods. Passing Bablok analysis demonstrated excellent correlation between IC/HPLC measurements and external quality assessment target values, for both chloride and sodium. With a limit of quantitation of 0.95 mmol/L, our method is suitable for the analysis of small amounts of sweat and can thus be used in combination with the Macroduct collection system. Although a chromatographic application results in a somewhat more expensive test compared to a Chlorocounter test, more accurate measurements are achieved. In addition, simultaneous measurements of sodium concentrations will result in better detection of false positives, less test repeating and thus faster and more accurate and effective diagnosis. The described IC/HPLC method, therefore, provides a precise, relatively cheap and easy-to-handle application for the analysis of both chloride and sodium in sweat. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Ion-pair in-tube solid-phase microextraction and capillary liquid chromatography using a titania-based column: application to the specific lauralkonium chloride determination in water.

Science.gov (United States)

Prieto-Blanco, M C; Moliner-Martínez, Y; López-Mahía, P; Campíns-Falcó, P

2012-07-27

A quick, miniaturized and on-line method has been developed for the determination in water of the predominant homologue of benzalkonium chloride, dodecyl dimethyl benzyl ammonium chloride or lauralkonium chloride (C(12)-BAK). The method is based on the formation of an ion-pair in both in-tube solid-phase microextraction (IT-SPME) and capillary liquid chromatography. The IT-SPME optimization required the study of the length and nature of the stationary phase of capillary and the processed sample volume. Because to the surfactant character of the analyte both, the extracting and replacing solvents, have played a decisive role in the IT-SPME optimized procedure. Conditioning the capillary with the mobile phase which contains the counter ion (acetate), using an organic additive (tetrabutylammonium chloride) added to the sample and a mixture water/methanol as replacing solvent (processed just before the valve is switched to the inject position), allowed to obtain good precision of the retention time and a narrow peak for C(12)-BAK. A reversed-phase capillary based TiO(2) column and a mobile phase containing ammonium acetate at pH 5.0 for controlling the interactions of cationic surfactant with titania surface were proposed. The optimized procedure provided adequate linearity, accuracy and precision at the concentrations interval of 1.5-300 μg L(-1) .The limit of detection (LOD) was 0.5 μg L(-1) using diode array detection (DAD). The applicability of proposed IT-SPME-capillary LC method has been assessed in several water samples. Copyright © 2012 Elsevier B.V. All rights reserved.

Rhenium corrosion in chloride melts

International Nuclear Information System (INIS)

Stepanov, A.D.; Shkol'nikov, S.N.; Vetyukov, M.M.

1989-01-01

The results investigating rhenium corrosion in chloride melts containing sodium, potassium and chromium ions by a gravimetry potentials in argon atmosphere in a sealing quarth cell are described. Rhenium corrosion is shown to be rather considerable in melts containing CrCl 2 . The value of corrosion rate depending on temperature is determined

Stabilization of high-level waste from a chloride volatility nuclear fuel reprocessing system

International Nuclear Information System (INIS)

Smith, L.A.; Thornton, T.A.

1979-01-01

Methods for stabilizing high-level waste from a chloride volatility thorium-based fuel coprocessing system have been studied. The waste, which is present as chloride salts, is combined with SiO 2 or Al 2 O 3 and pyrohydrolyzed to remove the chloride ions. The resulting solid is then combined with a flux and glassified. 3 figures, 4 tables

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

KAUST Repository

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

2014-01-01

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

Direct Detection of the Ion Pair to Free Ions Transformation upon Complexation with an Ion Receptor in Non-Polar Solvents by using Conductometry.

Science.gov (United States)

Iseda, Kazuya; Kokado, Kenta; Sada, Kazuki

2018-03-01

In this study, we performed conductometry in various organic solvents to directly detect the transformation from tetrabutylammonium chloride ( TBACl ) ion-pair salt to the free ions through complexation with meso -octamethylcalix[4]pyrrole ( CP ), which is a well-known receptor for chloride anions. In the presence of CP , the conductivity of TBACl increases in various non-polar solvents, indicating that complexation with CP enhances the ionic dissociation of TBACl in such non-polar solvents. In other words, CP recognizes chloride as an ion-paired salt as well as a free anion in non-polar solvents. Additionally, the TBA(CP - Cl ) complex exhibited a considerably lower ion-pairing constant ( K ip ) than TBACl in non-polar solvents, resulting in enhanced conductivity. Based on these findings, we can conclude that complexation of an anion with a hydrophobic anion receptor will be useful for creating functional and stimuli-responsive soft materials in organic solvents using coulombic forces.

Surface resistivity test evaluation as an indicator of the chloride permeability of concrete.

Science.gov (United States)

2012-12-01

Many agencies have adopted the standard tests for electrical : indication of concretes ability to resist chloride ion penetration : (AASHTO T 277 and ASTM C1202), commonly known as the rapid : chloride permeability test (RCPT), in their specificat...

Measurement of chloride and sulfate in residues from municipal solid waste incineration; Bestimmung von Chlorid und Sulfat in Reststoffen aus der thermischen Abfallbehandlung

Energy Technology Data Exchange (ETDEWEB)

Simon, F.G. [ABB Forschungszentrum, Abt. Umwelttechnologien, Baden-Daettwil (Switzerland); Birkenberger, R. [ABB Forschungszentrum, Abt. Umwelttechnologien, Baden-Daettwil (Switzerland); Schmidt, V. [ABB Forschungszentrum, Abt. Umwelttechnologien, Baden-Daettwil (Switzerland); Levina, M. [ABB Forschungszentrum, Abt. Umwelttechnologien, Baden-Daettwil (Switzerland)

1996-03-01

The concentrations of the chloride and sulfate in waste incineration ashes and leachate of these solids have been measured with ionselective electrodes and the ion chromotography. The results are compared with the legislative requirements. (orig.) [Deutsch] Die Konzentrationen der Anionen Chlorid und Sulfat in Abfallverbrennungsaschen sowie in Eluaten dieser Stoffe wurden mit ionenselektiven Elektroden und der Ionenchromotographie gemessen. Die Resultate werden mit den gesetzlichen Anforderungen verglichen. (orig.)

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

International Nuclear Information System (INIS)

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

1988-01-01

The effect of precipitation duration, acid concentration, indium complexing with chloride ions on the process of indium sulfide chemical precipitation in hydrochloric acid solutions, precipitate composition and dispersity are studied. It is established that indium sulfide solubility increases in solutions with acid concentration exceeding 0.40-0.45 mol/l. Calcium and indium chloride addition to diluted hydrochloric solutions greatly increases the solubility of indium sulfide. The effect of calcium chloride on In 2 S 3 solubility is higher than that of sodium chloride

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

International Nuclear Information System (INIS)

Lafont, C.; Alvarez, M.G.

1992-01-01

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

Electrochemical Migration on Electronic Chip Resistors in Chloride Environments

DEFF Research Database (Denmark)

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

2009-01-01

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

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

Science.gov (United States)

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

2010-01-01

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

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

Directory of Open Access Journals (Sweden)

Hongwei Deng

2010-11-01

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

Antisense oligonucleotides suppress cell-volume-induced activation of chloride channels.

Science.gov (United States)

Gschwentner, M; Nagl, U O; Wöll, E; Schmarda, A; Ritter, M; Paulmichl, M

1995-08-01

Cell volume regulation is an essential feature of most cells. After swelling in hypotonic media, the simultaneous activation of potassium and chloride channels is believed to be the initial, time-determining step in cell volume regulation. The activation of both pathways is functionally linked and enables the cells to lose ions and water, subsequently leading to cell shrinkage and readjustment of the initial volume. NIH 3T3 fibroblasts efficiently regulate their volume after swelling and bear chloride channels that are activated by decreasing extracellular osmolarity. The chloride current elicited in these cells after swelling is reminiscent of the current found in oocytes expressing an outwardly rectifying chloride current termed ICln. Introduction of antisense oligodeoxynucleotides complementary to the first 30 nucleotides of the coding region of the ICln channel into NIH 3T3 fibroblasts suppresses the activation of the swelling-induced chloride current. The experiments directly demonstrate an unambiguous link between a volume-activated chloride current and a cloned protein involved in chloride transport.

The electrochemical behaviour study of La3+ ion in fused chlorides bath. The LaNi5 formation

International Nuclear Information System (INIS)

Dias, Cristiane

2002-01-01

The electrochemical behaviour of La 3+ ion was studied in fused chlorides bath, with purpose to obtain LaNi 5 formation parameters. The lanthanum reduction/reoxidation mechanism and intermetallic compound formation were investigated by cyclic voltammetry, chronopotentiommetry and galvanostatic electrodeposition. The electrolyte employed was eutectic mixture NaCl-KCl (1:1) with anhydrous LaCl 3 as solute, since 0,25 mol. L -1 up to 2 mol. L -1 , between 700 deg C and 800 deg C. The anhydrous LaCl 3 was prepared by lanthanum chloride slow dehydration with HCl flow and heating until 300 deg C. Over molybdenum, results depicted that lanthanum electrochemical behaviour was quasi-reversible and electrodeposition occurred in a charge transfer step with three electrons. In nickel, intermetallic compound formation was observed by interdiffusion. The scanning electronic microscopy (SEM-EDS) and X ray diffraction analysis indicated that layers composition depend on temperature and solute concentration in fused bath. Mainly LaNi 5 intermetallic compound was formed with LaCl 3 anhydrous concentration of 2 mol. L -1 at 750 deg C, with cathodic current density until 100 mA.cm -2 . (author)

Anodic and cathodic reactions in molten calcium chloride

International Nuclear Information System (INIS)

Fray, D.J.

2002-01-01

Calcium chloride is a very interesting electrolyte in that it is available, virtually free, in high purity form as a waste product from the chemical industry. It has a very large solubility for oxide ions, far greater than many alkali halides and other divalent halides and has the same toxicity as sodium chloride and also a very high solubility in water. Intuitively, on the passage of current, it is expected that calcium would be deposited at the cathode and chlorine would evolve at the anode. However, if calcium oxide is added to the melt, it is possible to deposit calcium and evolve oxygen containing gases at the anode, making the process far less polluting than when chlorine is evolved. This process is discussed in terms of the addition of calcium to molten lead. Furthermore, these reactions can be altered dramatically depending upon the electrode materials and the other ions dissolved in the calcium chloride. As calcium is only deposited at very negative cathodic potentials, there are several interesting cathodic reactions that can occur and these include the decomposition of the carbonate ion and the ionization of oxygen, sulphur, selenium and tellurium. For example, if an oxide is used as the cathode in molten calcium chloride, the favoured reaction is shown to be the ionization of oxygen O + 2e - → O 2- rather than Ca 2+ + 2 e- → Ca. The oxygen ions dissolve in the salt leaving the metal behind, and this leads to the interesting hypothesis that metal oxides can be reduced directly to the metal purely by the use of electrons. Examples are given for the reduction of titanium dioxide, zirconium dioxide, chromium oxide and niobium oxide and by mixing oxide powders together and reducing the mixed compact, alloys and intermetallic compounds are formed. Preliminary calculations indicate that this new process should be much cheaper than conventional metallothermic reduction for these elements. (author)

Altered Chloride Homeostasis Decreases the Action Potential Threshold and Increases Hyperexcitability in Hippocampal Neurons

DEFF Research Database (Denmark)

Sørensen, Andreas T; Ledri, Marco; Melis, Miriam

2017-01-01

Chloride ions play an important role in controlling excitability of principal neurons in the central nervous system. When neurotransmitter GABA is released from inhibitory interneurons, activated GABA type A (GABAA) receptors on principal neurons become permeable to chloride. Typically, chloride...... neurons, and promote AP generation. It is generally recognized that altered chloride homeostasis per se has no effect on the AP threshold. Here, we demonstrate that chloride overload of mouse principal CA3 pyramidal neurons not only makes these cells more excitable through GABAA receptor activation...

Impact of chloride on the mineralogy of hydrated Portland cement systems

International Nuclear Information System (INIS)

Balonis, Magdalena; Lothenbach, Barbara; Le Saout, Gwenn; Glasser, Fredrik P.

2010-01-01

Chloride ion is in part bound into ordinary Portland cement paste and modifies its mineralogy. To understand this a literature review of its impacts has been made and new experimental data were obtained. Phase pure preparations of Friedel's salt, Ca 4 Al 2 (Cl) 1.95 (OH) 12.05 .4H 2 O, and Kuzel's salt, Ca 4 Al 2 (Cl)(SO 4 ) 0.5 (OH) 12 .6H 2 O, were synthesized and their solubilities were measured at 5, 25, 55 and 85 o C. After equilibration, solid phases were analysed by X-ray diffraction while the aqueous solutions were analysed by atomic absorption spectroscopy and ion chromatography. The solid solutions and interactions of Friedel's salt with other AFm phases were determined at 25 o C experimentally and by calculations. In hydrated cements, anion sites in AFm are potentially occupied by OH, SO 4 and CO 3 ions whereas Cl may be introduced under service conditions. Chloride readily displaces hydroxide, sulfate and carbonate in the AFm structures. A comprehensive picture of phase relations of AFm phases and their binding capacity for chloride is provided for pH ∼ 12 and 25 o C. The role of chloride in AFt formation and its relevance to corrosion of embedded steel are discussed in terms of calculated aqueous [Cl - ]/[OH - ] molar ratios.

Crystal structures and DFT calculations of mixed chloride-azide zinc(II) and chloride-isocyanate cadmium(II) complexes with the condensation product of 2-quinolinecarboxaldehyde and Girard's T reagent

Science.gov (United States)

Anđelković, Katarina; Pevec, Andrej; Grubišić, Sonja; Turel, Iztok; Čobeljić, Božidar; Milenković, Milica R.; Keškić, Tanja; Radanović, Dušanka

2018-06-01

The mixed chloride-azide [ZnL(N3)1.65Cl0.35] (1) and chloride-isocyanate [CdL(NCO)1.64Cl0.36] (2) complexes with the condensation product of 2-quinolinecarboxaldehyde and trimethylammonium acetohydrazide chloride (Girard's T reagent) (HLCl) have been prepared and characterized by X-ray crystallography. In complexes 1 and 2, Zn1 and Cd1 ions, respectively, are five-coordinated in a distorted square based pyramidal geometry with NNO set of donor atoms of deprotonated hydrazone ligand and two monodentate ligands N3- and/or N3- and Cl- in the case of 1 and OCN- and/or OCN- and Cl- in the case of 2. The structural parameters of 1 and 2 have been discussed in relation to those of previously reported M(II) complexes with the same hydrazone ligand. Density functional theory calculations have been employed to study the interaction between the Zn2+ and Cd2+ ions and ligands. High affinity of ligands towards the Zn2+ and Cd2+ ions are predicted for both complexes.

Functional modulation of cerebral gamma-aminobutyric acidA receptor/benzodiazepine receptor/chloride ion channel complex with ethyl beta-carboline-3-carboxylate: Presence of independent binding site for ethyl beta-carboline-3-carboxylate

Energy Technology Data Exchange (ETDEWEB)

Taguchi, J.; Kuriyama, K. (Kyoto Prefectural Univ. of Medicine (Japan))

1990-05-01

Effect of ethyl beta-carboline-3-carboxylate (beta-CCE) on the function of gamma-aminobutyric acid (GABA)A receptor/benzodiazepine receptor/chloride ion channel complex was studied. Beta-CCE noncompetitively and competitively inhibited (3H)flunitrazepam binding to benzodiazepine receptor, but not (3H)muscimol binding to GABAA receptor as well as t-(3H)butylbicycloorthobenzoate (( 3H) TBOB) binding to chloride ion channel, in particulate fraction of the mouse brain. Ro15-1788 also inhibited competitively (3H) flunitrazepam binding. On the other hand, the binding of beta-(3H)CCE was inhibited noncompetitively and competitively by clonazepam and competitively by Ro15-1788. In agreement with these results, benzodiazepines-stimulated (3H)muscimol binding was antagonized by beta-CCE and Ro15-1788. Gel column chromatography for the solubilized fraction from cerebral particulate fraction by 0.2% sodium deoxycholate (DOC-Na) in the presence of 1 M KCl indicated that beta-(3H)CCE binding site was eluted in the same fraction (molecular weight, 250,000) as the binding sites for (3H)flunitrazepam, (3H)muscimol and (3H)TBOB. GABA-stimulated 36Cl- influx into membrane vesicles prepared from the bovine cerebral cortex was stimulated and attenuated by flunitrazepam and beta-CCE, respectively. These effects of flunitrazepam and beta-CCE on the GABA-stimulated 36Cl- influx were antagonized by Ro15-1788. The present results suggest that the binding site for beta-CCE, which resides on GABAA receptor/benzodiazepine receptor/chloride ion channel complex, may be different from that for benzodiazepine. Possible roles of beta-CCE binding site in the allosteric inhibitions on benzodiazepine binding site as well as on the functional coupling between chloride ion channel and GABAA receptor are also suggested.

Determination of the stability constants of lanthanum, praseodymium, europium, erbium and lutetium complexes with chloride ions

International Nuclear Information System (INIS)

Fernandez R, E.

2008-01-01

The stability constants of La 3+ , Pr 3+ , Eu 3+ , Er 3+ and Lu 3+ chloride complexes were determined in perchloric acid media using a liquid-liquid extraction method. The dinonyl napthalene sulfonic acid in n-heptane was used as extractant. The lanthanide (Ln) concentrations were measured by a radiochemical (Eu and Lu) and a spectrophotometric (La, Pr, and Er) methods. In the last method, xylenol orange was used for the determinations at ph 6. The stability constants of lanthanum, praseodymium, erbium and lutetium chloride complexes were determined in 2, 3 and 4 M ionic strength and europium in 1, 2 and 3 M, at 303 K. The fitting of experimental data to the equations for the calculation of the stability constants, was carry out considering both one chemical species (LnCl 2+ ) or two chemical species (LnCl 2+ and LnCl 2 + ). The Specific Ion Interaction Theory was applied to the values of log β I Ln , Cl and the first stability constants at zero ionic strength were calculated by extrapolation. The same theory could not be applied to the log β I Ln , 2Cl , due to its low abundance and the values determined for the stability constants were similar. The distribution diagrams of the chemical species were obtained using the program MEDUSA and considering log β I Ln , CI , log β I Ln , 2CI values obtained in this work and the hydrolysis constants taken from the literature. The lanthanide chloride complexes are present in solution at specific conditions of ionic strength, concentration and in the absence of hydrolysis. The log β I Ln , Cl data were related to the charge density and the corresponding equations were obtained. These equations could be used to determine the stability constants along the lanthanide series. (Author)

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

Science.gov (United States)

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

2006-01-01

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

Analysis of chloride diffusivity in concrete containing red mud

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D.V. Ribeiro

Full Text Available Red mud is a solid waste produced in the alumina production process and, due to its high pH, is classified as hazardous. Its incorporation in concrete mixtures, acting as filler due to the particles fineness, might be an interesting reuse alternative. The focus of this paper is to study the chloride diffusivity of concrete mixtures containing red-mud. The concentration of chlorides was monitored by measuring the conductivity of the anolyte, which was distilled water initially. In addition, the estimation of the chloride ions diffusion coefficients in steady and non-steady conditions, Ds and Dns, was obtained from the ''time-lag'' and ''equivalent time'' between diffusion and migration experiments. Due to superfine particle-size distribution and the "filler" effect, the red mud addition seems to assure lower chloride diffusivity.

Chloride diffusivity in hardened cement paste from microscale analyses and accounting for binding effects

OpenAIRE

Carrara, P; De Lorenzis, L; Bentz, D P

2016-01-01

The diffusion of chloride ions in hardened cement paste (HCP) under steady-state conditions and accounting for the highly heterogeneous nature of the material is investigated. The HCP microstructures are obtained through segmentation of X-ray images of real samples as well as from simulations using the cement hydration model CEMHYD3D. Moreover, the physical and chemical interactions between chloride ions and HCP phases (binding), along with their effects on the diffusive process, are explicit...

Effect of cationic composition of electrolyte on kinetics of lead electrolytic separation in chloride melts

International Nuclear Information System (INIS)

Yurkinskij, V.P.; Makarov, D.V.

1995-01-01

The mechanism has been studied and kinetic parameters of the process of Pb(2) ion electrochemical reduction have been ascertained for different individual melts of alkali metal chlorides and their mixtures, using methods of linear voltammetry chronopotentiometry and chronoamperometry. It has been ascertained that cations in the melts of alkali metal chlorides affect stability of [PbCl n ] 2-n ions. The data obtained suggest that the strength of the complexes increases in the series NaCl-KCl-CsCl. In the melt of sodium chloride the electrode process is limited by diffusion, whereas in the melts of KCl, CsCl, CsCl-NaCl with cesium chloride content exceeding 70 mol% lead electrochemical reduction is controlled by preceding dissociation of the complexes. 10 refs., 3 figs., 2 tabs

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

Science.gov (United States)

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

2013-01-17

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

Effect of ultrasound on electrochemical chloride extraction from mortar

Science.gov (United States)

Chen, Yiqun; Yao, Wu; Zuo, Junqing

2018-03-01

In this paper, the effect of auxiliary ultrasound on electrochemical chloride extraction (ECE) was studied. The chloride removal efficiency was investigated by examining the chloride content with ultrasound-assisted ECE and changing the introducing time of ultrasound. The experimental results showed that removal of chloride ions was noted to be more effective in ECE treatment assisted with ultrasound treatment (UT). In addition, the lower w/c ratio led to more distinct effect of ultrasonic cavitation on chloride removal. Electrochemical behaviors measured with different treatment revealed that UT treatment was effective on moderating the corrosion condition. Microstructural analyses revealed a significant alteration in composition and morphology of cementitious phases with UT treatment. Pull-out tests indicated that ultrasound had a certain negative impact on the bond strength. Although the effect of introducing ultrasound in the first 2 weeks or the last 2 weeks on the extraction efficiency was not obvious, intermittent ultrasound could not only ensure the chloride extraction efficiency, but also reduce the adverse effect of ultrasound on the bond strength.

Structure transitions between copper-sulphate and copper-chloride ...

Indian Academy of Sciences (India)

Administrator

strate that co-adsorbed sulphate ions in the (√3 × √3)R30° UPD adlayer are replaced by chloride ions and, ..... phase 1 by the (5 × 5)-like chlo- ride phase 2 was mentioned in. 45,46,48,56 but not stud- ied in detail. These authors suggested that the replacement of SO. 2. 4. – .... A nonlinear regression fit of (1) to the experi-.

Markov Chain-Based Stochastic Modeling of Chloride Ion Transport in Concrete Bridges

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Yan Zhang

2018-03-01

Full Text Available Over the last decade, there has been an increasing interest in models for the evaluation and prediction of the condition of bridges in Canada due to their large number in an advanced state of deterioration. The models are used to develop optimal maintenance and replacement strategies to extend service life and optimally allocate financial and technical resources. The main process of deterioration of concrete bridges in Canada is corrosion of the reinforcing steel due to the widespread use of de-icing salts. In this article, numerical models of the diffusion process and chemical reactions of chloride ions in concrete are used to estimate the time to initiation of corrosion and for the progression of corrosion. The analyses are performed for a range of typical concrete properties, exposure and climatic conditions. The results from these simulations are used to develop parametric surrogate Markov chain models of increasing states of deterioration. The surrogate models are more efficient than physical models for the portfolio analysis of a large number of structures. The procedure provides an alternative to Markov models derived from condition ratings when historical inspection data is limited.

Resistance of Alkali-Activated Slag Concrete to Chloride-Induced Corrosion

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Joon Woo Park

2015-01-01

Full Text Available The corrosion resistance of steel in alkali-activated slag (AAS mortar was evaluated by a monitoring of the galvanic current and half-cell potential with time against a chloride-contaminated environment. For chloride transport, rapid chloride penetration test was performed, and chloride binding capacity of AAS was evaluated at a given chloride. The mortar/paste specimens were manufactured with ground granulated blast-furnace slag, instead of Portland cement, and alkali activators were added in mixing water, including Ca(OH2, KOH and NaOH, to activate hydration process. As a result, it was found that the corrosion behavior was strongly dependent on the type of alkali activator: the AAS containing the Ca(OH2 activator was the most passive in monitoring of the galvanic corrosion and half-cell potential, while KOH, and NaOH activators indicated a similar level of corrosion to Portland cement mortar (control. Despite a lower binding of chloride ions in the paste, the AAS had quite a higher resistance to chloride transport in rapid chloride penetration, presumably due to the lower level of capillary pores, which was ensured by the pore distribution of AAS mortar in mercury intrusion porosimetry.

The effect of steam curing on chloride penetration in geopolymer concrete

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Jaya Ekaputri Januarti

2017-01-01

Full Text Available In this paper, we present the result of our study on the effect of steam curing to chloride ion penetration in geopolymer concrete. Class F fly ash was activated using sodium hydroxide (NaOH and sodium silicate (Na2SiO3. The concrete specimens were then steam-cured at 40°C, 60°C, 80°C and room temperature at 24 hours. The treatment was followed by wet curing for 28 days, and then followed by immersion of all specimens in salt water for the durations of 30, 60, and 90 days. Cylindrical specimens were then prepared for compressive strength, chloride ion penetration, pH, and porosity tests. A 16 mm-steel bar was fixed at the center of the specimen concrete blocks (specimen size: 10cm × 10cm × 15cm. Corrosion probability was determined by conducting Half Cell Potential test. Our result showed that increasing the curing temperature to 80°C induced chloride ion penetration into the concrete’s effective pores, despite improvements in compressive strength. We also found that chloride ingress on the geopolymer concrete increases commensurately with the increase of the curing temperature. The corrosion potential measurement of geopolymer concrete was higher than OPC concrete even if corrosion was not observed in reinforcing. Based on our result, we suggest that the corrosion categorization for geopolymer concretes needs to be adjusted.

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

International Nuclear Information System (INIS)

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

2014-01-01

This study investigated the feasibility of using calcined layered double hydroxides (CLDHs) to prevent chloride-induced deterioration in reinforced concrete. CLDHs not only adsorbed chloride ions in aqueous solution with a memory effect but also had a much higher binding capacity than the original layered double hydroxides (LDHs) in the cement matrix. We investigated this adsorption in hardened cement paste in batch cultures to determine adsorption isotherms. The measured and theoretical binding capacities (153 mg g −1 and 257 mg g −1 , respectively) of the CLDHs were comparable to the theoretical capacity of Friedel's salt (2 mol mol −1 or 121 mg g −1 ), which belongs to the LDH family among cementitious phases. We simulated chloride adsorption by CLDHs through the cement matrix using the Fickian model and compared the simulation result to the X-ray fluorescence (XRF) chlorine map. Based on our results, it is proposed that the adsorption process is governed by the chloride transport through the cement matrix; this process differs from that in an aqueous solution. X-ray diffraction (XRD) analysis showed that the CLDH rebuilds the layered structure in a cementitious environment, thereby demonstrating the feasibility of applying CLDHs to the cement and concrete industries. - Highlights: • We examine the adsorption equilibrium and kinetics of CLDH in the hydrated cement. • CLDH capacity to bind chloride ions in the hydrated cement paste is determined. • We model chloride adsorption by CLDH through the cement matrix. • CLDH reforms the layered structure with ion adsorption in the cement matrix

Chloride channels as tools for developing selective insecticides.

Science.gov (United States)

Bloomquist, Jeffrey R

2003-12-01

Ligand-gated chloride channels underlie inhibition in excitable membranes and are proven target sites for insecticides. The gamma-aminobutyric acid (GABA(1)) receptor/chloride ionophore complex is the primary site of action for a number of currently used insecticides, such as lindane, endosulfan, and fipronil. These compounds act as antagonists by stabilizing nonconducting conformations of the chloride channel. Blockage of the GABA-gated chloride channel reduces neuronal inhibition, which leads to hyperexcitation of the central nervous system, convulsions, and death. We recently investigated the mode of action of the silphinenes, plant-derived natural compounds that structurally resemble picrotoxinin. These materials antagonize the action of GABA on insect neurons and block GABA-mediated chloride uptake into mouse brain synaptoneurosomes in a noncompetitive manner. In mammals, avermectins have a blocking action on the GABA-gated chloride channel consistent with a coarse tremor, whereas at longer times and higher concentrations, activation of the channel suppresses neuronal activity. Invertebrates display ataxia, paralysis, and death as the predominant signs of poisoning, with a glutamate-gated chloride channel playing a major role. Additional target sites for the avermectins or other chloride channel-directed compounds might include receptors gated by histamine, serotonin, or acetylcholine.The voltage-sensitive chloride channels form another large gene family of chloride channels. Voltage-dependent chloride channels are involved in a number of physiological processes including: maintenance of electrical excitability, chloride ion secretion and resorption, intravesicular acidification, and cell volume regulation. A subset of these channels is affected by convulsants and insecticides in mammals, although the role they play in acute lethality in insects is unclear. Given the wide range of functions that they mediate, these channels are also potential targets for

Prediction of chloride ingress and binding in cement paste

DEFF Research Database (Denmark)

Geiker, Mette Rica; Nielsen, Erik Pram; Herforth, Duncan

2007-01-01

This paper summarizes recent work on an analytical model for predicting the ingress rate of chlorides in cement-based materials. An integral part of this is a thermodynamic model for predicting the phase equilibria in hydrated Portland cement. The model’s ability to predict chloride binding...... in Portland cement pastes at any content of chloride, alkalis, sulfates and carbonate was verified experimentally and found to be equally valid when applied to other data in the literature. The thermodynamic model for predicting the phase equilibria in hydrated Portland cement was introduced into an existing...... Finite Difference Model for the ingress of chlorides into concrete which takes into account its multi-component nature. The “composite theory” was then used to predict the diffusivity of each ion based on the phase assemblage present in the hydrated Portland cement paste. Agreement was found between...

Elimination of chloride ions in the analytical method for the precise determination of plutonium or uranium using titanous ions as reductant

International Nuclear Information System (INIS)

Nicol-Rostaing, C.; Wagner, J.F.

1991-01-01

The Corpel and Regnaud's procedure for the precise determination of uranium and plutonium, using titanous (III) chloride as reductant has been modified in order to be compatible with the throwing out standards in nuclear plants. The removal of chloride reagents has been studied. On the original method, there are two: titanous chloride and ferric chloride. We propose titanous sulphate and ferric nitrate as substitution reagents. As commercial titanous sulphate can't be found, an easy procedure has been set and described with storage conditions: experimental conditions have been optimized and adapted for manufacturing on a laboratory scale [fr

Fluorinated tripodal receptors for potentiometric chloride detection in biological fluids.

Science.gov (United States)

Pankratova, Nadezda; Cuartero, Maria; Jowett, Laura A; Howe, Ethan N W; Gale, Philip A; Bakker, Eric; Crespo, Gastón A

2018-01-15

Fluorinated tripodal compounds were recently reported to be efficient transmembrane transporters for a series of inorganic anions. In particular, this class of receptors has been shown to be suitable for the effective complexation of chloride, nitrate, bicarbonate and sulfate anions via hydrogen bonding. The potentiometric properties of urea and thiourea-based fluorinated tripodal receptors are explored here for the first time, in light of the need for reliable sensors for chloride monitoring in undiluted biological fluids. The ion selective electrode (ISE) membranes with tren-based tris-urea bis(CF 3 ) tripodal compound (ionophore I) were found to exhibit the best selectivity for chloride over major lipophilic anions such as salicylate ( [Formula: see text] ) and thiocyanate ( [Formula: see text] ). Ionophore I-based ISEs were successfully applied for chloride determination in undiluted human serum as well as artificial serum sample, the slope of the linear calibration at the relevant background of interfering ions being close to Nernstian (49.8±1.7mV). The results of potentiometric measurements were confirmed by argentometric titration. Moreover, the ionophore I-based ISE membrane was shown to exhibit a very good long-term stability of potentiometric performance over the period of 10 weeks. Nuclear magnetic resonance (NMR) titrations, potentiometric sandwich membrane experiments and density functional theory (DFT) computational studies were performed to determine the binding constants and suggest 1:1 complexation stoichiometry for the ionophore I with chloride as well as salicylate. Copyright © 2017 Elsevier B.V. All rights reserved.

Continuous determination of the chloride level in the water of steam generators

International Nuclear Information System (INIS)

Deponge, J.; Friconneau, C.; Therond, J.P.

1974-01-01

Chloride ions may be continuously and rapidly determined with a silver-silver chloride metal electrode. The sensitive part of the electrode is a pressure compacted homogeneous mixture of silver and silver chloride. Opposed to a reference electrode (of a type used for determining the pH), the couple delivers a potential proportional to the concentration of chloride ions. After describing the principle of the determination, indicating the limitations and care in use to be taken and the reproducibility achieved, the associated transducer and transmitter are described. The transmitter as such is accurate to within about 2% over the entire utilization range. When used as a chloride-meter above 10ppm, the instrument retains its complete accuracy. Under this, the accuracy is obviously affected by the saturation of the transducer and its temperature sensitivity. The determination brackets varies from 10 to 0.1ppm and it can therefore be considered that as the temperature is +10 deg C or less, the accuracy is better than 5% up to 1ppm. Under that, the error increases considerably and can reach +-0.5ppm. If the temperature of the water is effectively +-10 deg C, the accuracy of the determination can drop to +-0.2ppm. Installations of this kind are in use on several nuclear boilers [fr

Lithium nickel cobalt manganese oxide synthesized using alkali chloride flux: morphology and performance as a cathode material for lithium ion batteries.

Science.gov (United States)

Kim, Yongseon

2012-05-01

Li(Ni(0.8)Co(0.1)Mn(0.1))O(2) (NCM811) was synthesized using alkali chlorides as a flux and the performance as a cathode material for lithium ion batteries was examined. Primary particles of the powder were segregated and grown separately in the presence of liquid state fluxes, which induced each particle to be composed of one primary particle with well-developed facet planes, not the shape of agglomerates as appears with commercial NCMs. The new NCM showed far less gas emission during high temperature storage at charged states, and higher volumetric capacity thanks to its high bulk density. The material is expected to provide optimal performances for pouch type lithium ion batteries, which require high volumetric capacity and are vulnerable to deformation caused by gas generation from the electrode materials.

Changes in cationic selectivity of the nicotinic channel at the rat ganglionic synapse: a role for chloride ions?

Science.gov (United States)

Sacchi, Oscar; Rossi, Maria Lisa; Canella, Rita; Fesce, Riccardo

2011-02-25

The permeability of the nicotinic channel (nAChR) at the ganglionic synapse has been examined, in the intact rat superior cervical ganglion in vitro, by fitting the Goldman current equation to the synaptic current (EPSC) I-V relationship. Subsynaptic nAChRs, activated by neurally-released acetylcholine (ACh), were thus analyzed in an intact environment as natively expressed by the mature sympathetic neuron. Postsynaptic neuron hyperpolarization (from -40 to -90 mV) resulted in a change of the synaptic potassium/sodium permeability ratio (P(K)/P(Na)) from 1.40 to 0.92, corresponding to a reversible shift of the apparent acetylcholine equilibrium potential, E(ACh), by about +10 mV. The effect was accompanied by a decrease of the peak synaptic conductance (g(syn)) and of the EPSC decay time constant. Reduction of [Cl(-)](o) to 18 mM resulted in a change of P(K)/P(Na) from 1.57 (control) to 2.26, associated with a reversible shift of E(ACh) by about -10 mV. Application of 200 nM αBgTx evoked P(K)/P(Na) and g(syn) modifications similar to those observed in reduced [Cl(-)](o). The two treatments were overlapping and complementary, as if the same site/mechanism were involved. The difference current before and after chloride reduction or toxin application exhibited a strongly positive equilibrium potential, which could not be explained by the block of a calcium component of the EPSC. Observations under current-clamp conditions suggest that the driving force modification of the EPSC due to P(K)/P(Na) changes represent an additional powerful integrative mechanism of neuron behavior. A possible role for chloride ions is suggested: the nAChR selectivity was actually reduced by increased chloride gradient (membrane hyperpolarization), while it was increased, moving towards a channel preferentially permeable for potassium, when the chloride gradient was reduced.

Changes in cationic selectivity of the nicotinic channel at the rat ganglionic synapse: a role for chloride ions?

Directory of Open Access Journals (Sweden)

Oscar Sacchi

Full Text Available The permeability of the nicotinic channel (nAChR at the ganglionic synapse has been examined, in the intact rat superior cervical ganglion in vitro, by fitting the Goldman current equation to the synaptic current (EPSC I-V relationship. Subsynaptic nAChRs, activated by neurally-released acetylcholine (ACh, were thus analyzed in an intact environment as natively expressed by the mature sympathetic neuron. Postsynaptic neuron hyperpolarization (from -40 to -90 mV resulted in a change of the synaptic potassium/sodium permeability ratio (P(K/P(Na from 1.40 to 0.92, corresponding to a reversible shift of the apparent acetylcholine equilibrium potential, E(ACh, by about +10 mV. The effect was accompanied by a decrease of the peak synaptic conductance (g(syn and of the EPSC decay time constant. Reduction of [Cl(-](o to 18 mM resulted in a change of P(K/P(Na from 1.57 (control to 2.26, associated with a reversible shift of E(ACh by about -10 mV. Application of 200 nM αBgTx evoked P(K/P(Na and g(syn modifications similar to those observed in reduced [Cl(-](o. The two treatments were overlapping and complementary, as if the same site/mechanism were involved. The difference current before and after chloride reduction or toxin application exhibited a strongly positive equilibrium potential, which could not be explained by the block of a calcium component of the EPSC. Observations under current-clamp conditions suggest that the driving force modification of the EPSC due to P(K/P(Na changes represent an additional powerful integrative mechanism of neuron behavior. A possible role for chloride ions is suggested: the nAChR selectivity was actually reduced by increased chloride gradient (membrane hyperpolarization, while it was increased, moving towards a channel preferentially permeable for potassium, when the chloride gradient was reduced.

Swell activated chloride channel function in human neutrophils

Energy Technology Data Exchange (ETDEWEB)

Salmon, Michael D. [Leukocyte and Ion Channel Research Laboratory, School of Health and Biosciences, University of East London, Stratford Campus, London E15 4LZ (United Kingdom); Ahluwalia, Jatinder, E-mail: j.ahluwalia@uel.ac.uk [Leukocyte and Ion Channel Research Laboratory, School of Health and Biosciences, University of East London, Stratford Campus, London E15 4LZ (United Kingdom)

2009-04-17

Non-excitable cells such as neutrophil granulocytes are the archetypal inflammatory immune cell involved in critical functions of the innate immune system. The electron current generated (I{sub e}) by the neutrophil NADPH oxidase is electrogenic and rapidly depolarises the membrane potential. For continuous function of the NADPH oxidase, I{sub e} has to be balanced to preserve electroneutrality, if not; sufficient depolarisation would prevent electrons from leaving the cell and neutrophil function would be abrogated. Subsequently, the depolarisation generated by the neutrophil NADPH oxidase I{sub e} must be counteracted by ion transport. The finding that depolarisation required counter-ions to compensate electron transport was followed by the observation that chloride channels activated by swell can counteract the NADPH oxidase membrane depolarisation. In this mini review, we discuss the research findings that revealed the essential role of swell activated chloride channels in human neutrophil function.

Degradation of fly ash concrete under the coupled effect of carbonation and chloride aerosol ingress

International Nuclear Information System (INIS)

Liu, Jun; Qiu, Qiwen; Chen, Xiaochi; Wang, Xiaodong; Xing, Feng; Han, Ningxu; He, Yijian

2016-01-01

Highlights: • Carbonation affects the chloride profile in concrete under chloride aerosol attack. • The chloride binding capacity can be reduced by the presence of carbonation. • Carbonation increases the rate of chloride diffusion for chloride aerosol ingress. • Chloride aerosol ingress reduces the carbonation depth and increases the pH value. • The use of fly ash in concrete enhances the resistance of chloride aerosol ingress. - Abstract: This paper presents an experimental investigation regarding the coupled effect of carbonation and chloride aerosol ingress on the durability performance of fly ash concrete. Test results demonstrate that carbonation significantly affects the chloride ingress profile, reduces the chloride binding capacity, and accelerates the rate of chloride ion diffusion. On the other hand, the carbonation rate of fly ash concrete is reduced by the presence of chlorides aerosol. The interaction nature between concrete carbonation and chloride aerosol ingress is also demonstrated by the microscopic analysis results obtained from scanning electron microscope and mercury intrusion porosimetry.

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

Directory of Open Access Journals (Sweden)

Wejman Katarzyna

2017-01-01

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

Structure and thermodynamic properties of molten alkali chlorides

International Nuclear Information System (INIS)

Ballone, P.; Pastore, G.; Tosi, M.P.; Trieste Univ.

1984-03-01

Self-consistent calculations of partial pair distribution functions and thermodynamic properties are presented for molten alkali chlorides in a non-polarizable-ion model. The theory starts from the hypernetted chain approximation and analyzes the role of bridge diagrams both for a two-component ionic plasma on a neutralizing background and for a binary ionic liquid of cations and anions. A simple account of excluded-volume effects suffices for a good description of the pair distribution functions in the two-component plasma, in analogy with earlier work on one-component fluids. The interplay of Coulomb attractions and repulsions in the molten salt requires, on the other hand, the inclusion of (i) excluded-volume effects for the various ion pairs as in a mixture of hard spheres with non-additive radii and (ii) medium-range Coulomb effects reflected mainly in the like-ion correlations. All these effects are included approximately in an empirical evaluation of the bridge functions, with numerical results which compare very well with computer simulation data. A detailed discussion of the results against experimental structural data is then given in the case of molten sodium chloride. (author)

Design of a Remote Monitoring System for Evaluation of Corrosión in Reinforced Concrete Structures under Chloride Ion Attack

Directory of Open Access Journals (Sweden)

Roa-Rodríguez Guillermo

2015-09-01

Full Text Available In this paper it was designed and built a remote monitoring equipment that allows to obtain the corrosion potential in reinforcing steels embedded in reinforced concrete, which were previously subjected to chloride attack in a hostile environment. The monitoring system, based on ASTM standard C876-91, determines from 0% to 100% the probability of corrosion on the samples tested. The system provides ease of perform field installation, if there is cellular network coverage, and may be operated remotely using text messages to start and stop measurements, whose results are stored in a local data logger on microSD cards and then are sent via the general packet radio service (GPRS to a web server which allows to access to the data via a web page, where the test results can be seen graphically. The concrete samples used as reference for monitoring degradation were immersed in chloride ion (3.5% NaCl for 12 months. Data for corrosion potential were generated through the exposureconcrete interface, corresponding to a system with a 90% probability of corrosion.

Catalytic Conversion of Cellulose to Levulinic Acid by Metal Chlorides

Directory of Open Access Journals (Sweden)

Beixiao Zhang

2010-08-01

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

Chloride equilibrium potential in salamander cones

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Bryson Eric J

2004-12-01

Full Text Available Abstract Background GABAergic inhibition and effects of intracellular chloride ions on calcium channel activity have been proposed to regulate neurotransmission from photoreceptors. To assess the impact of these and other chloride-dependent mechanisms on release from cones, the chloride equilibrium potential (ECl was determined in red-sensitive, large single cones from the tiger salamander retinal slice. Results Whole cell recordings were done using gramicidin perforated patch techniques to maintain endogenous Cl- levels. Membrane potentials were corrected for liquid junction potentials. Cone resting potentials were found to average -46 mV. To measure ECl, we applied long depolarizing steps to activate the calcium-activated chloride current (ICl(Ca and then determined the reversal potential for the current component that was inhibited by the Cl- channel blocker, niflumic acid. With this method, ECl was found to average -46 mV. In a complementary approach, we used a Cl-sensitive dye, MEQ, to measure the Cl- flux produced by depolarization with elevated concentrations of K+. The membrane potentials produced by the various high K+ solutions were measured in separate current clamp experiments. Consistent with electrophysiological experiments, MEQ fluorescence measurements indicated that ECl was below -36 mV. Conclusions The results of this study indicate that ECl is close to the dark resting potential. This will minimize the impact of chloride-dependent presynaptic mechanisms in cone terminals involving GABAa receptors, glutamate transporters and ICl(Ca.

Hydrolysis of ferric chloride in solution

International Nuclear Information System (INIS)

Lussiez, G.; Beckstead, L.

1996-11-01

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

Fundamental evaluation of in vivo labeling of red blood cells with Tc-99m using stannous chloride

Energy Technology Data Exchange (ETDEWEB)

Hiraki, T; Katayama, M; Ando, I; Ando, A [Kanazawa Univ. (Japan). School of Paramedicine; Hisada, K

1982-04-01

Stannous chloride was evaluated as a stannous ion source for the in vivo labeling of red blood cells(RBC) with Tc-99m. In this study, the labeling of RBC with Tc-99m was performed by two successive intravenous administrations of stannous chloride and Tc-99m-pertechnetate, and the optimal dose of stannous chloride and the optimal time interval between the two injections were evaluated. The labeling efficiency for this procedure was also evaluated as a function of time after the pertechnetate injection. The results of our investigation revealed that the maximal in vivo RBC labeling (86%) can be obtained at 15 min after the pertechnetate injection with an i.v. dose of 12.7 ..mu..g/kg of stannous chloride followed 15 min later by an i.v. injection of Tc-99m-pertechnetate. In conclusion, stannous chloride was found to be an excellent stannous ion source for the in vivo labeling of RBC with Tc-99m.

Ion transporters involved in acidification of the resorption lacuna in osteoclasts

DEFF Research Database (Denmark)

Henriksen, K.; Sorensen, M.G.; Jensen, V.K.

2008-01-01

Osteoclasts possess a large amount of ion transporters, which participate in bone resorption; of these, the vacuolar-adenosine trisphosphatase (V-ATPase) and the chloride-proton antiporter ClC-7 acidify the resorption lacuna. However, whether other ion transporters participate in this process is ......, including carbonic anhydrase II, the NHEs, and potassium-chloride cotransporters, are all involved in resorption but do not seem to directly be involved in acidification of the lysosomes Udgivelsesdato: 2008/9......Osteoclasts possess a large amount of ion transporters, which participate in bone resorption; of these, the vacuolar-adenosine trisphosphatase (V-ATPase) and the chloride-proton antiporter ClC-7 acidify the resorption lacuna. However, whether other ion transporters participate in this process...

Measurement of ageing effect on chloride diffusion coefficients in cementitious matrices

International Nuclear Information System (INIS)

Andrade, C.; Castellote, M.; D'Andrea, R.

2011-01-01

Most of the low-level nuclear waste disposal facilities are based in engineered multi barrier systems where reinforced concrete is one of the basic materials. The calculation of the time until steel reinforcement depassivation is a need due to the demand of prediction of the service life of concrete structures in radioactive repositories. In doing that, one of the main steps is the transport of chloride ions towards the reinforcement, as one of the most aggressive agents for the rebars in concrete is chloride ions. Ageing of concrete related to chloride penetration leads to significant decrease of the 'apparent diffusion' coefficient with time. If this effect is not considered, considerable bias can be introduced when predicting service life of reinforced concrete of repositories. Several effects have been addressed on their influence on the ageing of concrete, including the evolution with time of the concrete pore refinement, the binding of chlorides to the cement phases and to the changes of chloride 'surface concentration'. These effects have been studied in specimens made with different mixes trying to represent a wide range of mineral addition proportions. The analysis of their evolution with time has shown that the resistivity alone or the joint consideration of resistivity and binding capacity (C b /C f ), are appropriate parameters to appraise the diffusivity ageing. For practical reasons, an accelerated procedure is proposed in order to calculate ageing for short periods of time.

Corrosive gas generation potential from chloride salt radiolysis in plutonium environments

International Nuclear Information System (INIS)

Tandon, L.; Allen, T.H.; Mason, R.E.; Penneman, R.A.

1999-01-01

The specific goal of this project was to evaluate the magnitude and practical significance of radiation effects involving mixtures of chloride salts and plutonium dioxide (PuO 2 ) sealed in stainless steel containers and stored for up to 50 yr, after stabilization at 950 C and packaging according to US Department of Energy (DOE) standards. The potential for generating chemically aggressive molecular chlorine (and hydrogen chloride by interaction with adsorbed water or hydrogen gas) by radiolysis of chloride ions was studied. To evaluate the risks, an annotated bibliography on chloride salt radiolysis was created with emphasis on effects of plutonium alpha radiation. The authors present data from the material identification and surveillance (MIS) project obtained from examination and analysis of representative PuO 2 items from various DOE sites, including the headspace gas analysis data of sealed mixtures of PuO 2 and chloride salts following long-term storage

Study of the processes of ion pairs formation by the method of ion-ion coincidence: I2 and chlorine-containing hydrocarbons

International Nuclear Information System (INIS)

Golovin, A.V.

1991-01-01

A method of ion-ion coincidences was suggested to study the process of ion pairs formation during molecule photoionization. The principle of action of ion-ion coincidence method is based on recording of only the negative and positive ions that formed as a result of a molecule decomposition. The flowsheet of the facility of ion-ion coincidences was presented. The processes of ion pairs formation in iodine, chloroform, propyl-, n-propenyl-, tert.butyl- and benzyl-chlorides were studied. A simple model permitting to evaluate the dependence of quantum yield of ion pair formation on excitation energy was suggested

Effect of chloride and sulphate ions on the electrochemical corrosion behavior of alloy 800NG in PWR secondary water environment at 250 deg C

International Nuclear Information System (INIS)

Mansur, Fabio A.; Schvartzman, Monica Maria de A.M.; Quinan, Marco A.D.; Soares, Antonio E.G.; Nogueira, Pedro Henrique B.O.

2013-01-01

Alloy 800NG (nuclear grade) is used in nuclear steam generators (SG) as the tubing material for pressurized water reactors (PWRs) because of its high corrosion resistance. The corrosion resistance is due to the protective character of the oxide film formed on the tube surface by contact with the high temperature pressurized water. Nevertheless, corrosion has been the major cause of tube failures in nuclear SGs. The existing experience of different nuclear power plants shows that the water chemistry has an important role in maintaining the integrity of the protective oxide films. Many of such problems have been attributed to secondary side water chemistry conditions and excursions, many of which have been resulted from condenser cooling water ingress. Alloy 800 is known to undergo passivity breakdown and pitting in the presence of chloride ions under oxidative water conditions. In this work the effect of chloride and sulphate ions at various concentrations on the corrosion behavior of Alloy 800 tube at 250 deg C was investigated using the potentiodynamic anodic polarization technique. An active-passive transition occurred at 250 deg C in all studied conditions and the oxide film grown on surface showed greater porosity and lower resistance to localised corrosion in all studied conditions. (author)

Interpretation of postmortem vitreous concentrations of sodium and chloride.

Science.gov (United States)

Zilg, B; Alkass, K; Berg, S; Druid, H

2016-06-01

Vitreous fluid can be used to analyze sodium and chloride levels in deceased persons, but it remains unclear to what extent such results can be used to diagnose antemortem sodium or chloride imbalances. In this study we present vitreous sodium and chloride levels from more than 3000 cases. We show that vitreous sodium and chloride levels both decrease with approximately 2.2mmol/L per day after death. Since potassium is a well-established marker for postmortem interval (PMI) and easily can be analyzed along with sodium and chloride, we have correlated sodium and chloride levels with the potassium levels and present postmortem reference ranges relative the potassium levels. We found that virtually all cases outside the reference range show signs of antemortem hypo- or hypernatremia. Vitreous sodium or chloride levels can be the only means to diagnose cases of water or salt intoxication, beer potomania or dehydration. We further show that postmortem vitreous sodium and chloride strongly correlate and in practice can be used interchangeably if analysis of one of the ions fails. It has been suggested that vitreous sodium and chloride levels can be used to diagnose drowning or to distinguish saltwater from freshwater drowning. Our results show that in cases of freshwater drowning, vitreous sodium levels are decreased, but that this mainly is an effect of postmortem diffusion between the eye and surrounding water rather than due to the drowning process, since the decrease in sodium levels correlates with immersion time. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Advanced intermediate temperature sodium copper chloride battery

Science.gov (United States)

Yang, Li-Ping; Liu, Xiao-Min; Zhang, Yi-Wei; Yang, Hui; Shen, Xiao-Dong

2014-12-01

Sodium metal chloride batteries, also called as ZEBRA batteries, possess many merits such as low cost, high energy density and high safety, but their high operation temperature (270-350 °C) may cause several issues and limit their applications. Therefore, decreasing the operation temperature is of great importance in order to broaden their usage. Using a room temperature ionic liquid (RTIL) catholyte composed of sodium chloride buffered 1-ethyl-3-methylimidazolium chloride-aluminum chloride and a dense β″-aluminates solid electrolyte film with 500 micron thickness, we report an intermediate temperature sodium copper chloride battery which can be operated at only 150 °C, therefore alleviating the corrosion issues, improving the material compatibilities and reducing the operating complexities associated with the conventional ZEBRA batteries. The RTIL presents a high ionic conductivity (0.247 S cm-1) at 150 °C and a wide electrochemical window (-2.6 to 2.18 vs. Al3+/Al). With the discharge plateau at 2.64 V toward sodium and the specific capacity of 285 mAh g-1, this intermediate temperature battery exhibits an energy density (750 mWh g-1) comparable to the conventional ZEBRA batteries (728-785 mWh g-1) and superior to commercialized Li-ion batteries (550-680 mWh g-1), making it very attractive for renewable energy integration and other grid related applications.

Pitting corrosion susceptibility study of zirconium alloys in the presence of the chloride ions

International Nuclear Information System (INIS)

Radulescu, M.; Pirvan, I.; Velciu, L.

1997-01-01

Pitting corrosion mechanism is specific to metal/aggressive environment systems. The influence of both components of the process was thoroughly investigated. After reviewing the principal steps of the pitting corrosion and of the electrochemical reactions associated, there were presented the physico-chemical methods used for the determination of the corrosion pitting parameters completed with the metallographic techniques of investigation of the attacked surfaces. Reported are the results of determinations of the pit initiation (E np ) and pit passivation (E pp ) potentials in the systems Zy-4 (Zr)/ Cl - provided from the following solutions: HCl, FeCl 3 , NaCl and LiCl. In the case of the last two solutions, the measurements were carried out also in the range of alkaline pH values. It was also determined the dependence of E np and E pp potential on the Cl - ions concentration in NaCl and HCl solutions, and also the reaction order 'n' in presence of several chloride concentration. Finally, on the basis of the experimental data, we established the kinetic characteristics specific to different steps of pitting. (authors)

Selective transport and incorporation of highly charged metal and metal complex ions in self-assembled polyelectrolyte multilayer membranes

International Nuclear Information System (INIS)

Toutianoush, Ali; Tieke, Bernd

2002-01-01

The transport of aqueous salts containing mono-, di- and trivalent metal and tetravalent metal complex ions across ultrathin polyvinylammonium/polyvinylsulphate (PVA/PVS) membranes is described. The membranes were prepared by electrostatic layer-by-layer (LBL) assembly of the two polyelectrolytes. Using spectroscopic measurements and permeability studies, it is demonstrated that the transport of copper(II) chloride, lanthanum(III) chloride, barium chloride and potassium hexacyanoferrate(II) is accompanied by the permanent incorporation of the metal and metal complex ions in the membrane. Upon the uptake of copper, lanthanum and hexacyanoferrate ions, the membranes become cross-linked so that the permeation rates of other salts not taken up by the membrane, e.g. sodium chloride, potassium chloride and magnesium chloride, are decreased. The uptake of barium ions leads to a decrease of the cross-linking density of the membrane so that the permeation rate of NaCl is increased. Possible mechanisms for the ion uptake are discussed

[Determination of Chloride Salt Solution by NIR Spectroscopy].

Science.gov (United States)

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.

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

International Nuclear Information System (INIS)

Phansalkar, V.K.; Ravishankar, D.

1982-01-01

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

Chemistry of nepheline syenites interaction with calcium chloride at their joint baking

International Nuclear Information System (INIS)

Amirov, O.Kh.; Ruzieva, D.D.; Nazarov, Sh.B.; Safiev, Kh.; Mirsaidov, U.

2001-01-01

This work dedicated to determination of chemistry of leaking processes at nepheline syenites interaction with calcium chloride on baking stage. The main point of chemical conversion at baking of Turpe deposit nepheline with calcium chloride concluding in decomposition of acid insoluble raw materials minerals with formation of soluble in mineral acid minerals, that is take place the substitution ions of Na +, K +o f initial ore on Ca 2 + .

Study of the Susceptibility of Oxygen-Free Phosphorous Doped Copper to Corrosion in Simulated Groundwater in the Presence of Chloride and Sulfide

International Nuclear Information System (INIS)

Escobar, Ivan; Lamas, Claudia; Werme, Lars; Oversby, Virginia

2007-01-01

Oxygen free high conductivity copper, doped with phosphorus (Cu OFP) has been chosen as the material for the fabrication of high level nuclear waste containers in Sweden. This material will be the corrosion barrier for spent fuel in the environment of a deep geological repository in granitic rock. The service life of this container is expected to exceed 1,000,000 years. During this time, which includes several glaciations, water of different compositions, including high concentration of chloride ions, will contact the copper surface. This work reports a study of the susceptibility of Cu OFP to corrosion when chloride ions are present, in deionized water (DW) and in synthetic groundwater (SGW). The techniques used were electrochemical methods such as corrosion potential evolution and Tafel curves. The system was studied with Electrochemical Impedance Spectroscopy (EIS). We also used as characterization techniques Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS). The main conclusions are that copper is more susceptible to corrosion at high chloride ion concentration. When the chloride concentration is low, it is possible to form copper chloride crystals, but at the highest concentration, copper chloride complexes are formed, leaving the copper surface without deposits. When the chloride concentration is low ( -5 M), copper corrosion in the presence of chloride is controlled by diffusional processes, while at higher concentrations corrosion is controlled by charge transfer processes. (authors)

Response to comments on "Local impermeant anions establish the neuronal chloride concentration"

DEFF Research Database (Denmark)

Glykys, J; Dzhala, V; Egawa, K

2014-01-01

We appreciate the interest in our paper and the opportunity to clarify theoretical and technical aspects describing the influence of Donnan equilibria on neuronal chloride ion (Cl(-)) distributions....

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

International Nuclear Information System (INIS)

Campos Filho, Jorge Eustaquio de

2005-01-01

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

The influence of sodium salts (iodide, chloride and sulfate) on the formation efficiency of sulfamerazine nanocrystals.

Science.gov (United States)

Lou, Hao; Liu, Min; Qu, Wen; Johnson, James; Brunson, Ed; Almoazen, Hassan

2014-08-01

The purpose of this study is to evaluate the influence of sodium iodide, sodium chloride and sodium sulfate on the formation efficiency of sulfamerazine nanocrystals by wet ball milling. Sulfamerazine was milled using zirconium oxide beads in a solution containing polyvinylpyrrolidone (PVP) and a sodium salt (iodide, chloride or sulfate). Particle size distributions were evaluated by light diffraction before and after milling. High-performance liquid chromatography was utilized to determine the amount of PVP adsorbed onto sulfamerazine surface. Lyophilized nanocrystals were further characterized by differential scanning calorimetry and dissolution testing. Sulfate ion had more profound effect on reducing particle size via milling than iodide or chloride. We linked our findings to Hofmeister ion series, which indicates that sulfate ions tends to break the water structure, increases the surface tension and lowers the solubility of hydrocarbons in water. We hypothesized that the addition of sulfate ions dehydrated the PVP molecules and enhanced its adsorption onto the sulfamerazine particle surfaces. Consequently, the adsorbed PVP helped to stabilize of the nanosuspension. The nanocrystals that were obtained from the lyophilized milled suspensions exhibited a notable increase in dissolution rate. The addition of sodium sulfate enhanced the formation efficiency of sulfamerazine nanocrystals.

Influence of Blended Cements with Calcareous Fly Ash on Chloride Ion Migration and Carbonation Resistance of Concrete for Durable Structures.

Science.gov (United States)

Glinicki, Michał A; Jóźwiak-Niedźwiedzka, Daria; Gibas, Karolina; Dąbrowski, Mariusz

2016-01-02

The objective of this paper is to examine the possible use of new blended cements containing calcareous fly ash in structural concrete, potentially adequate for structural elements of nuclear power plants. The investigation included five new cements made with different contents of non-clinker constituents: calcareous fly ash, siliceous fly ash, ground granulated blastfurnace slag, and a reference cement-ordinary Portland cement. The influence of innovative cements on the resistance of concrete to chloride and carbonation exposure was studied. Additionally, an evaluation of the microstructure was performed using optical microscopy on concrete thin sections. Test results revealed a substantial improvement of the resistance to chloride ion penetration into concrete containing blended cements. The resistance was higher for increased clinker replacement levels and increased with curing time. However, concrete made with blended cements exhibited higher depth of carbonation than the Portland cement concrete, except the Portland-fly ash cement with 14.3% of calcareous fly ash. The thin sections analysis confirmed the values of the carbonation depth obtained from the phenolphthalein test. Test results indicate the possible range of application for new cements containing calcareous fly ash.

Influence of Blended Cements with Calcareous Fly Ash on Chloride Ion Migration and Carbonation Resistance of Concrete for Durable Structures

Directory of Open Access Journals (Sweden)

Michał A. Glinicki

2016-01-01

Full Text Available The objective of this paper is to examine the possible use of new blended cements containing calcareous fly ash in structural concrete, potentially adequate for structural elements of nuclear power plants. The investigation included five new cements made with different contents of non-clinker constituents: calcareous fly ash, siliceous fly ash, ground granulated blastfurnace slag, and a reference cement—ordinary Portland cement. The influence of innovative cements on the resistance of concrete to chloride and carbonation exposure was studied. Additionally, an evaluation of the microstructure was performed using optical microscopy on concrete thin sections. Test results revealed a substantial improvement of the resistance to chloride ion penetration into concrete containing blended cements. The resistance was higher for increased clinker replacement levels and increased with curing time. However, concrete made with blended cements exhibited higher depth of carbonation than the Portland cement concrete, except the Portland-fly ash cement with 14.3% of calcareous fly ash. The thin sections analysis confirmed the values of the carbonation depth obtained from the phenolphthalein test. Test results indicate the possible range of application for new cements containing calcareous fly ash.

Cathodic processes during ruthenium electrodeposition from a chloride melt

International Nuclear Information System (INIS)

Sokol'skij, D.V.

1985-01-01

Cathodic processes occurring during the electrolysis of chloride melts in the presence of oxygen-containing impurities were studied. The experiments were carried out at 500, 550 600 and 680 deg C, ruthenium ions concentration in KCl-NaCl-CsCl eutectic melt being 0.4-1.5 mol% and BaO additions 4.8x10 -2 mol%. Temperature dependence of Ru(3) ion diffusion coefficient in the chloride melt (lg D=3.25-1508/T+-0.02) and activation energy of the diffusion process (6.9 k cal/mol) were determined. It is shown that changes of the shape of E, t-curve and the deviation of values determined in the cause of chronopotentiometric investigations from the corresponding values of reversable processes are related in many respects to the participation of oxygen-containing compounds in the cathodic process. Irreversibility of the cathodic process is also connected with metal crystallization during electrodeposition

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

Science.gov (United States)

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

2010-04-22

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

Durability of reinforced adobe exposed to chloride ions

Directory of Open Access Journals (Sweden)

Giménez, A.

2006-12-01

Full Text Available One of the primary shortcomings of adobe, a dried mudblock stabilized with sisal hemp and cement widely used across all of Latin America, is its dimensional instability when exposed to water or aggressive environments. The present paper evaluates the electrochemical performance of reinforced adobe block after 1,000 days of exposure to a simulated marine environment. The specimens used were adobe blocks internally reinforced with 3/8-inch steel bars. The specimens were watered every two weeks: one group with potable water to simulate a natural urban environment and the other with a 3% sodium chloride solution to simulate a marine environment.Chloride penetration in powder extracted from the specimens was determined using the Mohr method. Electrochemical measurements included Gecor 6 electric potential(Eº and corrosion intensity (icorr readings. The final conclusion drawn from an analysis of the results was that in all cases the amount of free chlorides present sufficed to depassivate reinforcing steel and that the system component providing the most effective protection was the rough casting mortar. Consequently, this type of adobe mixes is not recommended for use in marine or industrial environments.La tierra-cemento-sisal es un material cuyo uso se encuentra muy difundido en toda Latinoamérica, entre sus principales limitaciones está la inestabilidad volumétrica ante el agua y ambientes agresivos. Por tal motivo, en este trabajo se evaluó el comportamiento electroquímico de bloques de tierra-cemento-sisal armado expuestos durante 1.000 días a un ambiente marino simulado. Las probetas utilizadas fueron bloques de tierra-cemento-sisal incorporándole internamente barras de acero de 3/8 de pulg. Las probetas se sometieron a un rociado quincenal: las de ambiente natural urbano con agua potable y las de ambiente marino simulado con una solución al 3% de cloruro de sodio. La penetración de cloruros se determinó extrayendo polvillo y

Ion Binding Energies Determining Functional Transport of ClC Proteins

Science.gov (United States)

Yu, Tao; Guo, Xu; Zou, Xian-Wu; Sang, Jian-Ping

2014-06-01

The ClC-type proteins, a large family of chloride transport proteins ubiquitously expressed in biological organisms, have been extensively studied for decades. Biological function of ClC proteins can be reflected by analyzing the binding situation of Cl- ions. We investigate ion binding properties of ClC-ec1 protein with the atomic molecular dynamics simulation approach. The calculated electrostatic binding energy results indicate that Cl- at the central binding site Scen has more binding stability than the internal binding site Sint. Quantitative comparison between the latest experimental heat release data isothermal titration calorimetry (ITC) and our calculated results demonstrates that chloride ions prefer to bind at Scen than Sint in the wild-type ClC-ec1 structure and prefer to bind at Sext and Scen than Sint in mutant E148A/E148Q structures. Even though the chloride ions make less contribution to heat release when binding to Sint and are relatively unstable in the Cl- pathway, they are still part contributors for the Cl- functional transport. This work provides a guide rule to estimate the importance of Cl- at the binding sites and how chloride ions have influences on the function of ClC proteins.

Separation of cerium and fractionation of rare earths from mixed chlorides

International Nuclear Information System (INIS)

Silva Queiroz, C.A. da; Sood, S.P.; Abrao, A.

1982-01-01

The separation of cerium from rare earths chlorides solutions by precipitation with hydrogen peroxide/air/dil. ammonium hydroxide; purification of cerium; fractionation by ion exchange and analytical control of the process are presented. (A.R.H.) [pt

Evaluation Technique of Chloride Penetration Using Apparent Diffusion Coefficient and Neural Network Algorithm

Directory of Open Access Journals (Sweden)

Yun-Yong Kim

2014-01-01

Full Text Available Diffusion coefficient from chloride migration test is currently used; however this cannot provide a conventional solution like total chloride contents since it depicts only ion migration velocity in electrical field. This paper proposes a simple analysis technique for chloride behavior using apparent diffusion coefficient from neural network algorithm with time-dependent diffusion phenomena. For this work, thirty mix proportions of high performance concrete are prepared and their diffusion coefficients are obtained after long term-NaCl submerged test. Considering time-dependent diffusion coefficient based on Fick’s 2nd Law and NNA (neural network algorithm, analysis technique for chloride penetration is proposed. The applicability of the proposed technique is verified through the results from accelerated test, long term submerged test, and field investigation results.

Resistance of Cementitious Binders to Chloride Induced Corrosion of Embedded Steel by Electrochemical and Microstructural Studies

International Nuclear Information System (INIS)

Song, Ha Won; Ann, Ki Yong; Kim, Tae Sang

2009-01-01

The high alkaline property in the concrete pore solution protects the embedded steel in concrete from corrosion due to aggressive ions attack. However, a continuous supply of those ions, in particular, chlorides altogether with a pH fall in electrochemical reaction on the steel surface eventually depassivate the steel to corrode. To mitigate chloride-induced corrosion in concrete structures, finely grained mineral admixtures, for example, pulverized fuel ash (PFA), ground granulated blast furnace slag (GGBS) and silica fume (SF) have been often advised to replace ordinary Portland cement (OPC) partially as binder. A consistent assessment of those partial replacements has been rarely performed with respect to the resistance of each binder to corrosion, although the studies for each binder were extensively looked into in a way of measuring the corrosion rate, influence of microstructure or chemistry of chlorides ions with cement hydrations. The paper studies the behavior of steel corrosion, chloride transport, pore structure and buffering capacity of those cementitious binders. The corrosion rate of steel in mortars of OPC, 30% PFA, 60% GGBS and 10% SF respectively, with chloride in cast ranging from 0.0 to 3.0% by weight of binder was measured at 7, 28 and 150 days to determine the chloride threshold level and the rate of corrosion propagation, using the anodic polarization technique. Mercury intrusion porosimetry was also applied to cement pastes of each binder at 7 and 28 days to ensure the development of pore structure. Finally, the release rate of bound chlorides (I.e. buffering capacity) was measured at 150 days. The chloride threshold level was determined assuming that the corrosion rate is beyond 1-2 mA/m 3 at corrosion and the order of the level was OPC > 10% SF > 60% GGBS > 30% PFA. Mercury intrusion porosimetry showed that 10% SF paste produced the most dense pore structure, followed by 60% GGBS, 30% PFA and OPC pastes, respectively. It was found that OPC

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

International Nuclear Information System (INIS)

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

2010-01-01

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

Surface speciation and interactions between adsorbed chloride and water on cerium dioxide

Science.gov (United States)

Sutherland-Harper, Sophie; Taylor, Robin; Hobbs, Jeff; Pimblott, Simon; Pattrick, Richard; Sarsfield, Mark; Denecke, Melissa; Livens, Francis; Kaltsoyannis, Nikolas; Arey, Bruce; Kovarik, Libor; Engelhard, Mark; Waters, John; Pearce, Carolyn

2018-06-01

Ceria particles with different specific surface areas (SSA) were contaminated with chloride and water, then heat treated at 500 and 900 °C to investigate sorption behaviour of these species on metal oxides. Results from x-ray photoelectron spectroscopy and infrared spectroscopy showed chloride and water adsorption onto particles increased with surface area and that these species were mostly removed on heat treatment (from 6.3 to 0.8 at% Cl- on high SSA and from 1.4 to 0.4 at% on low SSA particles). X-ray diffraction revealed that chloride was not incorporated into the bulk ceria structure, but crystal size increased upon contamination. Ce LIII-edge x-ray absorption spectroscopy confirmed that chloride was not present in the first co-ordination sphere around Ce(IV) ions, so was not bonded to Ce as chloride in the bulk structure. Sintering of contaminated high SSA particles occurred with heat treatment at 900 °C, and they resembled low SSA particles synthesised at this temperature. Physical chloride-particle interactions were investigated using electron microscopy and energy dispersive x-ray analysis, showing that chloride was homogeneously distributed on ceria and that reduction of porosity did not trap surface-sorbed chloride inside the particles as surface area was reduced during sintering. This has implications for stabilisation of chloride-contaminated PuO2 for long term storage.

Synthesis, photophysical and metal ion signalling behaviour of mono

Indian Academy of Sciences (India)

Unknown

component systems, ... tion and heavy metal ions, is of considerable interest for various ... cause of the macrocyclic effect, expect to show ... whose chloride salt, mercuric chloride, was used. ... filtered, concentrated, washed with water and ex-.

Co2+ ion exchange with NaY

International Nuclear Information System (INIS)

Garcia, I.; Solache-Rios, M.; Bulbulian, S.; Bosch, P.

1993-01-01

Co 2+ ion exchange from aqueous cobalt chloride-sodium chloride solutions with NaY zeolite has been investigated. The effect of contact time on the sorption of Co 2+ by dehydrated Y zeolite at 150 degrees C is unusual. A fast sorption uptake is observed in which 1.73 mequiv/g of zeolite of Na + ions is replaced by cobalt ions, followed by a desorption process where the uptake decreases to 1.56 mequiv/g of zeolite. This behavior is explained by the location and coordination of cobalt in Y zeolite sites. It is suggested that the maximum uptake corresponds to cobalt ions being simultaneously in two sites; tetrahedrally coordinated in the sodalite units and octahedrally coordinated in the large cavities. It is also suggested that the desorption process is a consequence of a reaction between Cl - ions and the tetrahedral species. 20 refs., 4 figs

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

Science.gov (United States)

2010-10-01

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

Polyvinyl chloride resin

International Nuclear Information System (INIS)

Kim, Hong Jae

1976-06-01

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

Inhibition of herpes simplex virus type 1 entry by chloride channel inhibitors tamoxifen and NPPB

Energy Technology Data Exchange (ETDEWEB)

Zheng, Kai [Guangzhou Jinan Biomedicine Research and Development Center, National Engineering Research Center of Genetic Medicine, Jinan University, Guangzhou (China); College of Life Science and Technology, Jinan University, Guangzhou (China); Chen, Maoyun [Guangzhou Jinan Biomedicine Research and Development Center, National Engineering Research Center of Genetic Medicine, Jinan University, Guangzhou (China); College of pharmacy, Jinan University, Guangzhou (China); Xiang, Yangfei; Ma, Kaiqi [Guangzhou Jinan Biomedicine Research and Development Center, National Engineering Research Center of Genetic Medicine, Jinan University, Guangzhou (China); Jin, Fujun [Guangzhou Jinan Biomedicine Research and Development Center, National Engineering Research Center of Genetic Medicine, Jinan University, Guangzhou (China); College of pharmacy, Jinan University, Guangzhou (China); Wang, Xiao [School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006 (China); Wang, Xiaoyan; Wang, Shaoxiang [Guangzhou Jinan Biomedicine Research and Development Center, National Engineering Research Center of Genetic Medicine, Jinan University, Guangzhou (China); Wang, Yifei, E-mail: twang-yf@163.com [Guangzhou Jinan Biomedicine Research and Development Center, National Engineering Research Center of Genetic Medicine, Jinan University, Guangzhou (China)

2014-04-18

Highlights: • We analyze the anti-HSV potential of chloride channel inhibitors. • Tamoxifen and NPPB show anti-HSV-1 and anti-ACV-resistant HSV-1 activities. • HSV-1 infection induces intracellular chloride concentration increasing. • Tamoxifen and NPPB inhibit HSV-1 early infection. • Tamoxifen and NPPB prevent the fusion process of HSV-1. - Abstract: Herpes simplex virus type 1 (HSV-1) infection is very common worldwide and can cause significant health problems from periodic skin and corneal lesions to encephalitis. Appearance of drug-resistant viruses in clinical therapy has made exploring novel antiviral agents emergent. Here we show that chloride channel inhibitors, including tamoxifen and 5-nitro-2-(3-phenyl-propylamino) benzoic acid (NPPB), exhibited extensive antiviral activities toward HSV-1 and ACV-resistant HSV viruses. HSV-1 infection induced chloride ion influx while treatment with inhibitors reduced the increase of intracellular chloride ion concentration. Pretreatment or treatment of inhibitors at different time points during HSV-1 infection all suppressed viral RNA synthesis, protein expression and virus production. More detailed studies demonstrated that tamoxifen and NPPB acted as potent inhibitors of HSV-1 early entry step by preventing viral binding, penetration and nuclear translocation. Specifically the compounds appeared to affect viral fusion process by inhibiting virus binding to lipid rafts and interrupting calcium homeostasis. Taken together, the observation that tamoxifen and NPPB can block viral entry suggests a stronger potential for these compounds as well as other ion channel inhibitors in antiviral therapy against HSV-1, especially the compound tamoxifen is an immediately actionable drug that can be reused for treatment of HSV-1 infections.

Inhibition of herpes simplex virus type 1 entry by chloride channel inhibitors tamoxifen and NPPB

International Nuclear Information System (INIS)

Zheng, Kai; Chen, Maoyun; Xiang, Yangfei; Ma, Kaiqi; Jin, Fujun; Wang, Xiao; Wang, Xiaoyan; Wang, Shaoxiang; Wang, Yifei

2014-01-01

Highlights: • We analyze the anti-HSV potential of chloride channel inhibitors. • Tamoxifen and NPPB show anti-HSV-1 and anti-ACV-resistant HSV-1 activities. • HSV-1 infection induces intracellular chloride concentration increasing. • Tamoxifen and NPPB inhibit HSV-1 early infection. • Tamoxifen and NPPB prevent the fusion process of HSV-1. - Abstract: Herpes simplex virus type 1 (HSV-1) infection is very common worldwide and can cause significant health problems from periodic skin and corneal lesions to encephalitis. Appearance of drug-resistant viruses in clinical therapy has made exploring novel antiviral agents emergent. Here we show that chloride channel inhibitors, including tamoxifen and 5-nitro-2-(3-phenyl-propylamino) benzoic acid (NPPB), exhibited extensive antiviral activities toward HSV-1 and ACV-resistant HSV viruses. HSV-1 infection induced chloride ion influx while treatment with inhibitors reduced the increase of intracellular chloride ion concentration. Pretreatment or treatment of inhibitors at different time points during HSV-1 infection all suppressed viral RNA synthesis, protein expression and virus production. More detailed studies demonstrated that tamoxifen and NPPB acted as potent inhibitors of HSV-1 early entry step by preventing viral binding, penetration and nuclear translocation. Specifically the compounds appeared to affect viral fusion process by inhibiting virus binding to lipid rafts and interrupting calcium homeostasis. Taken together, the observation that tamoxifen and NPPB can block viral entry suggests a stronger potential for these compounds as well as other ion channel inhibitors in antiviral therapy against HSV-1, especially the compound tamoxifen is an immediately actionable drug that can be reused for treatment of HSV-1 infections

A study on the initiation of pitting corrosion in carbon steel in chloride-containing media using scanning electrochemical probes

International Nuclear Information System (INIS)

Lin Bin; Hu Ronggang; Ye Chenqing; Li Yan; Lin Changjian

2010-01-01

Scanning electrochemical probes of corrosion potential and chloride ions were developed for the in situ monitoring of localized corrosion processes of reinforcing steel in NaCl-containing solution. The results indicated that the chloride ions (Cl - ) preferentially adsorbed and accumulated at the imperfect/defective sites, resulting in initiation and propagation of pitting corrosion on the reinforcing steel surface. An electron microprobe analyzer (EMPA) was used to examine the corrosion morphology and elemental distribution at the corroded location to investigate the origins of the preferential Cl - adsorption and pitting corrosion. By combining the in situ and ex situ images, we concluded that manganese sulfide inclusions in reinforcing steel are the most susceptible defects to pitting corrosion in chloride-containing solution.

Comparison of Freezing and Hydrate Formation Methods in Removing Chloride and Bromide Ions from Brine

Directory of Open Access Journals (Sweden)

Marzieh Fattahi

2018-01-01

Full Text Available The growing population and enhanced industrial activities coupled with limitations on freshwater availability have led to efforts to desalinate salt water from the seas. Membrane and thermal technologies are the two commonly used for this purpose. In this study, the direct freezing and hydrate formation techniques were used for salt water desalination. Materials and Methods: Distilled water, sodium chloride, and sodium bromide were used as raw materials in the experiments. The experimental setup included a stationary reactor with two coaxial cylinders, in which ice crystals were deposited outside the cool inner cylinder to increase the salt concentration in the residual brine. An electrical conductivity instrument was used to measure sal removal. Results: Salt removal was shown to decrease with increasing salt concentration in the direct freeze method. A different trend was, however, observed in the hydrate formation method; salt removal was negligible at low concentrations in this method but increased at high concentrations before a constant value was reached. Overall, the hydrate formation recorded a higher salt removal efficiency than the other method. To investigate the effect of anion size on salt removal efficiency, experiments were carried out using NaCl and NaBr, which have the same cation but different anion sizes. Result showed that removal efficiency increased with increasing anion size. Conclusion: It was found that increasing ion radius leads to the lower likelihood of ion presence in the crystal lattice, thereby reducing salt removal efficiency. On the other hand, low concentrations of salt serve as site for the generation of cores, which naturally serve as removal accelerators.

Effect of Chlorides on Conductivity and Dielectric Constant in Hardened Cement Mortar: NDT for Durability Evaluation

Directory of Open Access Journals (Sweden)

Sunkook Kim

2016-01-01

Full Text Available Dielectric constant and conductivity, the so-called EM properties (electromagnetic, are widely adopted for NDT (Nondestructive Technique in order to detect damage or evaluate performance of concrete without damage to existing RC (reinforced concrete. Among deteriorating agents, chloride ion is considered as one of the most critical threats due to rapid penetration and direct effect on steel corrosion. In the work, cement mortar samples with 3 w/c (water-to-cement ratios and 4 levels of chloride addition are considered. Conductivity and dielectric constant are measured in the normal frequency range. They increase with strength of mortar and more chloride ions due to denser pore formation. Furthermore, the behaviors of measured EM property are investigated with carbonation velocity and strength, which shows an attempt of application to durability evaluation through EM measurement.

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

International Nuclear Information System (INIS)

Holcomb, H.P.

1985-01-01

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

Sweat chloride as a biomarker of CFTR activity: proof of concept and ivacaftor clinical trial data.

Science.gov (United States)

Accurso, Frank J; Van Goor, Fredrick; Zha, Jiuhong; Stone, Anne J; Dong, Qunming; Ordonez, Claudia L; Rowe, Steven M; Clancy, John Paul; Konstan, Michael W; Hoch, Heather E; Heltshe, Sonya L; Ramsey, Bonnie W; Campbell, Preston W; Ashlock, Melissa A

2014-03-01

We examined data from a Phase 2 trial {NCT00457821} of ivacaftor, a CFTR potentiator, in cystic fibrosis (CF) patients with aG551D mutation to evaluate standardized approaches to sweat chloride measurement and to explore the use of sweat chloride and nasal potential difference (NPD) to estimate CFTR activity. Sweat chloride and NPD were secondary endpoints in this placebo-controlled, multicenter trial. Standardization of sweat collection, processing,and analysis was employed for the first time. Sweat chloride and chloride ion transport (NPD) were integrated into a model of CFTR activity. Within-patient sweat chloride determinations showed sufficient precision to detect differences between dose-groups and assess ivacaftor treatment effects. Analysis of changes in sweat chloride and NPD demonstrated that patients treated with ivacaftor achieved CFTR activity equivalent to approximately 35%–40% of normal. Sweat chloride is useful in multicenter trials as a biomarker of CFTR activity and to test the effect of CFTR potentiators.

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

DEFF Research Database (Denmark)

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

2008-01-01

Some ionic compounds (salts) form liquids when heated to temperatures in the range of 200-300 °C. They may be referred to as moderate temperature ionic liquids. An example of such a compound is the 1,1,3,3- tetramethylguanidinium chloride, [TMGH]Cl, melting at ∼212 °C. The chemistry of this compo......Some ionic compounds (salts) form liquids when heated to temperatures in the range of 200-300 °C. They may be referred to as moderate temperature ionic liquids. An example of such a compound is the 1,1,3,3- tetramethylguanidinium chloride, [TMGH]Cl, melting at ∼212 °C. The chemistry...... and the dimeric chloride ion-pair salt converged to give geometries near the established crystal structure of [TMGH]Cl. The structures and their binding energies are given as well as calculated vibrational harmonic normal modes (IR and Raman band wavenumbers and intensities). Experimentally obtained Raman...... scattering spectra are presented and assigned, by comparing to the quantum mechanical calculations. It is concluded that dimeric molecular ion pairs with four N-H+ · · · Cl- hydrogen bonds probably exist in the solutions and are responsible for the relatively high solubility of the “salt” in ethanol...

Gadolinium-hydrogen ion exchange of zirconium phosphate

Science.gov (United States)

Liu, D. C.; Power, J. L.

1972-01-01

The Gd(+3)/H(+) ion exchange on a commercial zirconium phosphate ion exchanger was investigated in chloride, sulfate, and phosphate solutions of Gd(+3) at gadolinium concentrations of 0.001 to 1 millimole per cc and in the pH range of 0 to 3.5. Relatively low Gd(+3) capacities, in the range of 0.01 to 0.1 millimole per g of ion exchanger were found at room temperature. A significant difference in Gd(+3) sorption was observed, depending on whether the ion exchanger was converted from initial conditions of greater or lesser Gd(+3) sorption than the specific final conditions. Correlations were found between decrease in Gd(+3) capacity and loss of exchanger phosphate groups due to hydrolysis during washing and between increase in capacity and treatment with H3PO4. Fitting of the experimental data to ideal ion exchange equilibrium expressions indicated that each Gd(+3) ion is sorbed on only one site of the ion exchanger. The selectivity quotient was determined to be 2.5 + or - 0.4 at room temperature on gadolinium desorption in chloride solutions.

Thermodynamic analysis of separating lead and antimony in chloride system

Institute of Scientific and Technical Information of China (English)

CHEN Jin-zhong; CAO Hua-zhen; LI Bo; YUAN Hai-jun; ZHENG Guo-qu; YANG Tian-zu

2009-01-01

In chloride system, thermodynamic analysis is a useful guide to separate lead and antimony as well as to understand the separation mechanism. An efficient and feasible way for separating lead and antimony was discussed. The relationships of [Pb2+][Cl-]2-lg[Cl]T and E-lg[Cl]T in Pb-Sb-Cl-H2O system were studied, and the solubilities of lead chloride at different antimony concentrations were calculated based on principle of simultaneous equilibrium. The results show that insoluble salt PbCl2 will only exist stably in a certain concentration range of chlorine ion. This concentration range of chlorine ion expands a little with increasing the concentration of antimony in the system while narrows as the system acidity increases. The solubility of Pb2+ in solution decreases with increasing the concentration of antimony in the system, whereas increases with increasing the concentration of total chlorine. The concentration range of total chlorine causing lead solubility less than 0.005 mol/L increases monotonically.

Experimental investigation on the threshold chloride concentration for corrosion initiation in reinforced concrete structures

International Nuclear Information System (INIS)

Byung Hwan Oh; Seung Yup Jang

2005-01-01

The corrosion of steel reinforcements in concrete is of great importance in the view of safety and durability of reinforced concrete structures. This study is focused on the corrosion behavior of steel bars induced by internal chlorides in concrete. The main objective of this study is to determine the threshold chloride concentration causing depassivation and active corrosion of steel reinforcement in concrete. To examine the threshold concentration of chloride ion, the half-cell potential, the chemical composition of extracted pore solutions of concrete and the extent of corroded area of the specimens were measured. Major test variables include the added amount of chlorides in concrete, type of binder, and water-to-binder ratios. From the present comprehensive test results, the factors influencing threshold chloride concentration are investigated, and the rational ranges of threshold chloride concentration causing active corrosion of steels are proposed. The present study provides the realistic chloride limit for corrosion initiation of reinforced concrete structures, which can be used efficiently in the future technical specification. (authors)

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

International Nuclear Information System (INIS)

Tatsuya Suzuki

2013-01-01

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

Role of chloride ions in the promotion of auxin-induced growth of maize coleoptile segments.

Science.gov (United States)

Burdach, Zbigniew; Kurtyka, Renata; Siemieniuk, Agnieszka; Karcz, Waldemar

2014-10-01

The mechanism of auxin action on ion transport in growing cells has not been determined in detail. In particular, little is known about the role of chloride in the auxin-induced growth of coleoptile cells. Moreover, the data that do exist in the literature are controversial. This study describes experiments that were carried out with maize (Zea mays) coleoptile segments, this being a classical model system for studies of plant cell elongation growth. Growth kinetics or growth and pH changes were recorded in maize coleoptiles using two independent measuring systems. The growth rate of the segments was measured simultaneously with medium pH changes. Membrane potential changes in parenchymal cells of the segments were also determined for chosen variants. The question of whether anion transport is involved in auxin-induced growth of maize coleoptile segments was primarily studied using anion channel blockers [anthracene-9-carboxylic acid (A-9-C) and 4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid (DIDS)]. In addition, experiments in which KCl was replaced by KNO3 were also performed. Both anion channel blockers, added at 0·1 mm, diminished indole-3-acetic acid (IAA)-induced elongation growth by ~30 %. Medium pH changes measured simultaneously with growth indicated that while DIDS stopped IAA-induced proton extrusion, A-9-C diminished it by only 50 %. Addition of A-9-C to medium containing 1 mm KCl did not affect the characteristic kinetics of IAA-induced membrane potential changes, while in the presence of 10 mm KCl the channel blocker stopped IAA-induced membrane hyperpolarization. Replacement of KCl with KNO3 significantly decreased IAA-induced growth and inhibited proton extrusion. In contrast to the KCl concentration, the concentration of KNO3 did not affect the growth-stimulatory effect of IAA. For comparison, the effects of the cation channel blocker tetraethylammonium chloride (TEA-Cl) on IAA-induced growth and proton extrusion were also determined. TEA

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

Energy Technology Data Exchange (ETDEWEB)

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

1970-08-14

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

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

International Nuclear Information System (INIS)

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

1999-01-01

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

Corrosion Resistance of Calcium Aluminate Cement Concrete Exposed to a Chloride Environment.

Science.gov (United States)

Ann, Ki Yong; Cho, Chang-Geun

2014-01-28

The present study concerns a development of calcium aluminate cement (CAC) concrete to enhance the durability against an externally chemically aggressive environment, in particular, chloride-induced corrosion. To evaluate the inhibition effect and concrete properties, CAC was partially mixed with ordinary Portland cement (OPC), ranging from 5% to 15%, as a binder. As a result, it was found that an increase in the CAC in binder resulted in a dramatic decrease in the setting time of fresh concrete. However, the compressive strength was lower, ranging about 20 MPa, while OPC indicated about 30-35 MPa at an equivalent age. When it comes to chloride transport, there was only marginal variation in the diffusivity of chloride ions. The corrosion resistance of CAC mixture was significantly enhanced: its chloride threshold level for corrosion initiation exceeded 3.0% by weight of binder, whilst OPC and CAC concrete indicated about 0.5%-1.0%.

Synthesis, characterization and metal adsorption properties of the new ion exchanger polymer 3-n-propyl(4-methylpyridinium) silsesquioxane chloride.

Science.gov (United States)

Magosso, H A; Panteleimonov, A V; Kholin, Y V; Gushikem, Y

2006-11-01

The preparation and anion exchange properties of 3-n-propyl(4-methylpyridinium) silsesquioxane chloride polymer are described. This new polymer was prepared by the sol-gel processing method and is designated as SiPic+Cl-. It is insoluble in water and showed an anion exchange capacity of 1.46x10(-3) mol g-1. The adsorption isotherms of ZnCl2, CdCl2 and HgCl2 were determined from aqueous solutions and the adsorption equilibria simulations fit the model of fixed bidentate centers with the absence of lateral interactions and energetic heterogeneity between them. The metal ions diffuse into the solid solution interface and are dominantly present as MCl2-(4) species for Zn(II), MCl(2-)4 and MCl-3 species for Cd(II) and MCl-3 species for Hg(II).

Chloride concentrations in human hepatic cytosol and mitochondria are a function of age.

Science.gov (United States)

Jahn, Stephan C; Rowland-Faux, Laura; Stacpoole, Peter W; James, Margaret O

2015-04-10

We recently reported that, in a concentration-dependent manner, chloride protects hepatic glutathione transferase zeta 1 from inactivation by dichloroacetate, an investigational drug used in treating various acquired and congenital metabolic diseases. Despite the importance of chloride ions in normal physiology, and decades of study of chloride transport across membranes, the literature lacks information on chloride concentrations in animal tissues other than blood. In this study we measured chloride concentrations in human liver samples from male and female donors aged 1 day to 84 years (n = 97). Because glutathione transferase zeta 1 is present in cytosol and, to a lesser extent, in mitochondria, we measured chloride in these fractions by high-performance liquid chromatography analysis following conversion of the free chloride to pentafluorobenzylchloride. We found that chloride concentration decreased with age in hepatic cytosol but increased in liver mitochondria. In addition, chloride concentrations in cytosol, (105.2 ± 62.4 mM; range: 24.7-365.7 mM) were strikingly higher than those in mitochondria (4.2 ± 3.8 mM; range 0.9-22.2 mM). These results suggest a possible explanation for clinical observations seen in patients treated with dichloroacetate, whereby children metabolize the drug more rapidly than adults following repeated doses, and also provide information that may influence our understanding of normal liver physiology. Copyright © 2015 Elsevier Inc. All rights reserved.

Alkali metal bismuth(III) chloride double salts

Energy Technology Data Exchange (ETDEWEB)

Kelly, Andrew W. [Department of Chemistry, College of William and Mary, Williamsburg, VA 23187 (United States); Nicholas, Aaron; Ahern, John C. [Department of Chemistry, University of Maine, Orono, ME 04469 (United States); Chan, Benny [Department of Chemistry, College of New Jersey, Ewing, NJ 08628-0718 (United States); Patterson, Howard H. [Department of Chemistry, University of Maine, Orono, ME 04469 (United States); Pike, Robert D., E-mail: rdpike@wm.edu [Department of Chemistry, College of William and Mary, Williamsburg, VA 23187 (United States)

2016-06-15

Evaporative co-crystallization of MCl (M = Na, K, Rb, Cs) with BiOCl in aqueous HCl produces double salts: M{sub x}Bi{sub y}Cl{sub (x+3y)}·zH{sub 2}O. The sodium salt, Na{sub 2}BiCl{sub 5}·5H{sub 2}O (monoclinic P2{sub 1}/c, a = 8.6983(7) Å, b = 21.7779(17) Å, c = 7.1831(6) Å, β = 103.0540(10)°, V = 1325.54(19) Å{sup 3}, Z = 4) is composed of zigzag chains of μ{sub 2}-Cl-cis-linked (BiCl{sub 5}){sub n}{sup 2n–} chains. Edge-sharing chains of NaCl{sub n}(OH{sub 2}){sub 6−n} octahedra (n = 0, 2, 3) are linked through μ{sub 3}-Cl to Bi. The potassium salt, K{sub 7}Bi{sub 3}Cl{sub 16} (trigonal R−3c, a = 12.7053(9) Å, b = 12.7053(9) Å, c = 99.794(7) Å, V = 13,951(2) Å{sup 3}, Z = 18) contains (Bi{sub 2}Cl{sub 10}){sup 4–} edge-sharing dimers of octahedra and simple (BiCl{sub 6}){sup 3–} octahedra. The K{sup +} ions are 5- to 8-coordinate and the chlorides are 3-, 4-, or 5-coordinate. The rubidium salt, Rb{sub 3}BiCl{sub 6}·0.5H{sub 2}O (orthorhombic Pnma, a = 12.6778(10) Å, b = 25.326(2) Å, c = 8.1498(7) Å, V = 2616.8(4) Å{sup 3}, Z = 8) contains (BiCl{sub 6}){sup 3–} octahedra. The Rb{sup +} ions are 6-, 8-, and 9-coordinate, and the chlorides are 4- or 5-coordinate. Two cesium salts were formed: Cs{sub 3}BiCl{sub 6} (orthorhombic Pbcm, a = 8.2463(9) Å, b = 12.9980(15) Å, c = 26.481(3) Å, V = 2838.4(6) Å{sup 3}, Z = 8) being comprised of (BiCl{sub 6}){sup 3–} octahedra, 8-coordinate Cs{sup +}, and 3-, 4-, and 5-coordinate Cl{sup −}. In Cs{sub 3}Bi{sub 2}Cl{sub 9} (orthorhombic Pnma, a = 18.4615(15) Å, b = 7.5752(6) Å, c = 13.0807(11) Å, V = 1818.87(11) Å{sup 3}, Z = 4) Bi octahedra are linked by μ{sub 2}-bridged Cl into edge-sharing Bi{sub 4} squares which form zigzag (Bi{sub 2}Cl{sub 9}){sub n}{sup 3n–} ladders. The 12-coordinate Cs{sup +} ions bridge the ladders, and the Cl{sup −} ions are 5- and 6-coordinate. Four of the double salts are weakly photoluminescent at 78 K, each showing a series of three excitation peaks

Determination of eugenol in rat plasma by liquid chromatography-quadrupole ion trap mass spectrometry using a simple off-line dansyl chloride derivatization reaction to enhance signal intensity.

Science.gov (United States)

Beaudry, Francis; Guénette, Sarah Annie; Vachon, Pascal

2006-11-01

A rapid, selective and sensitive method was developed for the determination of eugenol concentration using an off-line dansyl chloride derivatization step to enhance signal intensity. The method consisted of a protein precipitation extraction followed by derivatization with dansyl chloride and analysis by full scan liquid chromatography electrospray quadrupole ion trap mass spectrometry (LC-ESI-QIT). The separation was achieved using a 100 x 2 mm C(8) analytical column combined with an isocratic mobile phase composed of 75:25 acetonitrile: 0.1% formic acid in water set at a flow rate of 0.25 mL/min. Signal intensity of the eugenol-dansyl chloride derivative was increased up to 100-fold as compared with the underivatized eugenol in positive electrospray mode. An analytical range of 100-20,000 ng/mL was used in the calibration curve of plasma and blood samples. The LOD observed was 0.5 pg injected on column. The novel method met all requirements of specificity, sensitivity, linearity, precision, accuracy and stability. In conclusion, a rapid and sensitive LC-ESI/MS/MS method using a derivatization agent was developed to enhance signal intensity of eugenol. Copyright (c) 2006 John Wiley & Sons, Ltd.

Effect of ion concentrations on uranium absorption from sodium carbonate solutions

International Nuclear Information System (INIS)

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

1979-01-01

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

HPLC determination of chloride, bromide and iodide ions in drinking water and industrial effluents using trifluoromethylmercuric nitrate as derivatizing reagent

International Nuclear Information System (INIS)

Arain, M.A.; Bhanger, M.I.; Khuhawar, M.Y.

1997-01-01

A simple procedure for the simultaneous determination of various halides in drinking water and industrial effluents of Hyderabad and Iodized salt is reported. The method utilizes derivatization of halides through trifluoromethylmercuric nitrate in aqueous solution, extraction in petroleum ether followed by reverse phase HPLC separation using c-18 Lichrosorb column, 150 x 4 mm i.d., mobile phase methanol : water (20: 80) and UV detection at 225 nm. Linear calibration ranges for chloride, bromide and iodide (0-10 ug/mL) with correlation coefficient 0.996, 0.998 and 0.989 have been determined with lowest possible detection limit as 1.0, 0.25 and 1.5 Mu g/ml, respectively. The effect of various interfering ions is also discussed. (author)

Crystal structure of tetraethylammonium chloride 3,4,5,6-tetrafluoro-1,2-diiodobenzene

Directory of Open Access Journals (Sweden)

Jasmine Viger-Gravel

2015-05-01

Full Text Available Equimolar quantities of tetraethylammonium chloride (Et4NCl and 3,4,5,6-tetrafluoro-1,2-diiodobenzene (o-DITFB or o-C6F4I2 have been co-crystallized in a solution of dichloromethane yielding a pure halogen-bonded compound, 3,4,5,6-tetrafluoro-1,2-diiodobenzene–tetraethyl ammonium chloride (2/1, Et4N+·Cl−·2C6F4I2, in the form of translucent needles. [(Et4NCl(o-C6F4I22] packs in the C2/c space group. The asymmetric unit includes one molecule of DITFB, one Et4N+ cation located on a twofold rotation axis, and one chloride anion also located on a twofold rotation symmetry axis. This compound has an interesting halogen-bonding environment surrounding the halide. Here, the chloride anion acts as a tetradentate halogen bond acceptor and forms a distorted square-pyramidal geometry, with I...Cl−...I angles of 80.891 (6 and 78.811 (11°, where two crystallographically distinct iodine atoms form halogen bonds with the chloride anion. Resulting from that square-pyramidal geometry are short contacts between some of the adjacent F atoms. Along the b axis, the halogen-bonding interaction results in a polymeric network, producing a sheet in which the two closest chloride ions are 7.8931 (6 Å apart. The Et4N+ cation alternates in columns with the halide ion. The expected short contacts (shorter than the sum of their van der Waals radii are observed for the halogen bonds [3.2191 (2 and 3.2968 (2 Å], as well as almost linear angles [170.953 (6 and 173.529 (6°].

Equilibrium Studies on the Extraction of Yttrium from Chloride Medium by Mono (2-Ethylhexyl) 2-Ethylhexyl Phosphonic Acid (Ion quest 801)

International Nuclear Information System (INIS)

Zaki, E.E.; Ismail, Z.H.; Aly, H.F.; Sabet, S.A.

2008-01-01

Since 90 Y is one of the useful radioisotopes in nuclear medicine, liquid-liquid extraction of yttrium from chloride medium has been studied under various conditions using neutralized and un-neutralized mono (2-ethylhexyl) 2-ethylhexyl phosphonic acid (EHEHPA) as an extractant. Effect of reagent concentration, ph of the aqueous medium, metal ion concentration and nature of the diluent on the extraction process has been carried out. Effect of temperature was studied and thermodynamic parameters were evaluated. Yttrium extracted in organic phase was stripped with various reagents. The stoichiometry of the extracted species of yttrium was determined on the basis of slope analysis of experimental results. Equilibrium equations of the extraction process have been estimated and verified

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

International Nuclear Information System (INIS)

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

2006-01-01

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

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.

Science.gov (United States)

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.

Effect of pH and chloride concentration on the removal of hexavalent chromium in a batch electrocoagulation reactor

International Nuclear Information System (INIS)

Arroyo, M.G.; Perez-Herranz, V.; Montanes, M.T.; Garcia-Anton, J.; Guinon, J.L.

2009-01-01

In this work, the effect of pH and chloride ions concentration on the removal of Cr(VI) from wastewater by batch electrocoagulation using iron plate electrodes has been investigated. The initial solution pH was adjusted with different concentrations of H 2 SO 4 . The presence of chloride ions enhances the anode dissolution due to pitting corrosion. Fe 2+ ions formed during the anode dissolution cause the reduction of Cr(VI) to form Cr(III), which are co-precipitated with Fe 3+ ions at relatively low pH. The reduction degree of Cr(VI) to Cr(III) and the solubility of metal hydroxide species (both chromic and iron hydroxides) depend on pH. At higher concentrations of H 2 SO 4 , the reduction of Cr(VI) to Cr(III) by Fe 2+ ions is preferred, but the coagulation of Fe 3+ and Cr(III) is favoured at the lower H 2 SO 4 concentrations.

Effect of pH and chloride concentration on the removal of hexavalent chromium in a batch electrocoagulation reactor

Energy Technology Data Exchange (ETDEWEB)

Arroyo, M.G. [Departamento de Ingenieria Quimica y Nuclear, Universidad Politecnica de Valencia, Camino de Vera s/n, 46022 Valencia (Spain); Perez-Herranz, V., E-mail: vperez@iqn.upv.es [Departamento de Ingenieria Quimica y Nuclear, Universidad Politecnica de Valencia, Camino de Vera s/n, 46022 Valencia (Spain); Montanes, M.T.; Garcia-Anton, J.; Guinon, J.L. [Departamento de Ingenieria Quimica y Nuclear, Universidad Politecnica de Valencia, Camino de Vera s/n, 46022 Valencia (Spain)

2009-09-30

In this work, the effect of pH and chloride ions concentration on the removal of Cr(VI) from wastewater by batch electrocoagulation using iron plate electrodes has been investigated. The initial solution pH was adjusted with different concentrations of H{sub 2}SO{sub 4}. The presence of chloride ions enhances the anode dissolution due to pitting corrosion. Fe{sup 2+} ions formed during the anode dissolution cause the reduction of Cr(VI) to form Cr(III), which are co-precipitated with Fe{sup 3+} ions at relatively low pH. The reduction degree of Cr(VI) to Cr(III) and the solubility of metal hydroxide species (both chromic and iron hydroxides) depend on pH. At higher concentrations of H{sub 2}SO{sub 4}, the reduction of Cr(VI) to Cr(III) by Fe{sup 2+} ions is preferred, but the coagulation of Fe{sup 3+} and Cr(III) is favoured at the lower H{sub 2}SO{sub 4} concentrations.

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

Energy Technology Data Exchange (ETDEWEB)

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

2011-07-01

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

Prediction of the Chloride Resistance of Concrete Modified with High Calcium Fly Ash Using Machine Learning.

Science.gov (United States)

Marks, Michał; Glinicki, Michał A; Gibas, Karolina

2015-12-11

The aim of the study was to generate rules for the prediction of the chloride resistance of concrete modified with high calcium fly ash using machine learning methods. The rapid chloride permeability test, according to the Nordtest Method Build 492, was used for determining the chloride ions' penetration in concrete containing high calcium fly ash (HCFA) for partial replacement of Portland cement. The results of the performed tests were used as the training set to generate rules describing the relation between material composition and the chloride resistance. Multiple methods for rule generation were applied and compared. The rules generated by algorithm J48 from the Weka workbench provided the means for adequate classification of plain concretes and concretes modified with high calcium fly ash as materials of good, acceptable or unacceptable resistance to chloride penetration.

The spectroscopy and structure of some lanthanide chlorides in amide solutions

International Nuclear Information System (INIS)

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

1974-01-01

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

Preparation of a microporous polymer electrolyte based on poly(vinyl chloride)/poly(acrylonitrile-butyl acrylate) blend for Li-ion batteries

International Nuclear Information System (INIS)

Tian, Zheng; Pu, Weihua; He, Xiangming; Wan, Chunrong; Jiang, Changyin

2007-01-01

Poly(acrylonitrile-co-butyl acrylate) (P(AN-co-BuA))/poly(vinyl chloride) (PVC) blend-based gel polymer electrolyte (BGPE) was prepared for lithium-ion batteries. The P(AN-co-BuA)/PVC BGPE consists of an electrolyte-rich phase, which is mainly composed of P(AN-co-BuA) and liquid electrolyte, acting as a conducting channel and a PVC-rich phase that provides mechanical strength. The dual phase was just simply developed by the difference of miscibility properties in solvent, PC, between P(AN-co-BuA) and PVC. The mechanical strength of this new blend electrolyte was found to be much higher, with a fracture stress as high as 29 MPa in dry membrane and 21 MPa in gel state, than that of a previously reported P(AN-co-BuA)-based gel polymer electrolyte. The blended gel polymer electrolyte showed ionic conductivity of higher than 1.5 x 10 -3 S cm -1 and electrochemical stability up to at least 4.8 V. The results showed that the as-prepared gel polymer electrolytes were promising materials for lithium-ion batteries

Preparation of a microporous polymer electrolyte based on poly(vinyl chloride)/poly(acrylonitrile-butyl acrylate) blend for Li-ion batteries

Energy Technology Data Exchange (ETDEWEB)

Tian, Zheng; Pu, Weihua; He, Xiangming; Wan, Chunrong; Jiang, Changyin [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China)

2007-02-15

Poly(acrylonitrile-co-butyl acrylate) (P(AN-co-BuA))/poly(vinyl chloride) (PVC) blend-based gel polymer electrolyte (BGPE) was prepared for lithium-ion batteries. The P(AN-co-BuA)/PVC BGPE consists of an electrolyte-rich phase, which is mainly composed of P(AN-co-BuA) and liquid electrolyte, acting as a conducting channel and a PVC-rich phase that provides mechanical strength. The dual phase was just simply developed by the difference of miscibility properties in solvent, PC, between P(AN-co-BuA) and PVC. The mechanical strength of this new blend electrolyte was found to be much higher, with a fracture stress as high as 29 MPa in dry membrane and 21 MPa in gel state, than that of a previously reported P(AN-co-BuA)-based gel polymer electrolyte. The blended gel polymer electrolyte showed ionic conductivity of higher than 1.5 x 10{sup -3} S cm{sup -1} and electrochemical stability up to at least 4.8 V. The results showed that the as-prepared gel polymer electrolytes were promising materials for lithium-ion batteries. (author)

A chloride tolerant laccase from the plant pathogen ascomycete Botrytis aclada expressed at high levels in Pichia pastoris.

Science.gov (United States)

Kittl, Roman; Mueangtoom, Kitti; Gonaus, Christoph; Khazaneh, Shima Tahvilda; Sygmund, Christoph; Haltrich, Dietmar; Ludwig, Roland

2012-01-20

Fungal laccases from basidiomycetous fungi are thoroughly investigated in respect of catalytic mechanism and industrial applications, but the number of reported and well characterized ascomycetous laccases is much smaller although they exhibit interesting catalytic properties. We report on a highly chloride tolerant laccase produced by the plant pathogen ascomycete Botrytis aclada, which was recombinantly expressed in Pichia pastoris with an extremely high yield and purified to homogeneity. In a fed-batch fermentation, 495 mg L(-1) of laccase was measured in the medium, which is the highest concentration obtained for a laccase by a yeast expression system. The recombinant B. aclada laccase has a typical molecular mass of 61,565 Da for the amino acid chain. The pI is approximately 2.4, a very low value for a laccase. Glycosyl residues attached to the recombinant protein make up for approximately 27% of the total protein mass. B. aclada laccase exhibits very low K(M) values and high substrate turnover numbers for phenolic and non-phenolic substrates at acidic and near neutral pH. The enzyme's stability increases in the presence of chloride ions and, even more important, its substrate turnover is only weakly inhibited by chloride ions (I(50)=1.4M), which is in sharp contrast to most other described laccases. This high chloride tolerance is mandatory for some applications such as implantable biofuel cells and laccase catalyzed reactions, which suffer from the presence of chloride ions. The high expression yield permits fast and easy production for further basic and applied research. Copyright © 2011 Elsevier B.V. All rights reserved.

The Effect of Crack Width on Chloride-Induced Corrosion of Steel in Concrete

Directory of Open Access Journals (Sweden)

Weiwei Li

2017-01-01

Full Text Available When subjected to loading or thermal shrinkage, reinforced concrete structures usually behave in a cracking state, which raises the risk of bar corrosion from the working environment. The influence of cover cracking on chloride-induced corrosion was experimentally investigated through a 654-day laboratory test on cracked reinforced concrete specimens exposed to chloride solution. The concrete specimens have a dimension of 100 mm × 100 mm × 400 mm and a single prefabricated crack at the midspan. When the percentage concentration of chloride ion (0.6%, 1.2%, 2.1%, 3.0%, and 6.0% and crack width (uncracked, 0.2, 0.3, 0.4, and 0.5 mm are taken as variables, the experimental results showed that the corrosion rates for cracked specimens increased with increasing percentage concentration of chloride and increasing crack width. This study also showed the interrelationship between crack width and percentage concentration of chloride on the corrosion rate. In addition, an empirical model, incorporating the influence of the cover cracking and chloride concentration, was developed to predict the corrosion rate. This model allows the prediction of the maximum allowable wcr based on the given percentage concentration of chloride in the exposure condition.

A genetically-encoded YFP sensor with enhanced chloride sensitivity, photostability and reduced ph interference demonstrates augmented transmembrane chloride movement by gerbil prestin (SLC26a5).

Science.gov (United States)

Zhong, Sheng; Navaratnam, Dhasakumar; Santos-Sacchi, Joseph

2014-01-01

Chloride is the major anion in cells, with many diseases arising from disordered Cl- regulation. For the non-invasive investigation of Cl- flux, YFP-H148Q and its derivatives chameleon and Cl-Sensor previously were introduced as genetically encoded chloride indicators. Neither the Cl- sensitivity nor the pH-susceptibility of these modifications to YFP is optimal for precise measurements of Cl- under physiological conditions. Furthermore, the relatively poor photostability of YFP derivatives hinders their application for dynamic and quantitative Cl- measurements. Dynamic and accurate measurement of physiological concentrations of chloride would significantly affect our ability to study effects of chloride on cellular events. In this study, we developed a series of YFP derivatives to remove pH interference, increase photostability and enhance chloride sensitivity. The final product, EYFP-F46L/Q69K/H148Q/I152L/V163S/S175G/S205V/A206K (monomeric Cl-YFP), has a chloride Kd of 14 mM and pKa of 5.9. The bleach time constant of 175 seconds is over 15-fold greater than wild-type EYFP. We have used the sensor fused to the transmembrane protein prestin (gerbil prestin, SLC26a5), and shown for the first time physiological (mM) chloride flux in HEK cells expressing this protein. This modified fluorescent protein will facilitate investigations of dynamics of chloride ions and their mediation of cell function. Modifications to YFP (EYFP-F46L/Q69K/H148Q/I152L/V163S/S175G/S205V/A206K (monomeric Cl-YFP) results in a photostable fluorescent protein that allows measurement of physiological changes in chloride concentration while remaining minimally affected by changes in pH.

A genetically-encoded YFP sensor with enhanced chloride sensitivity, photostability and reduced ph interference demonstrates augmented transmembrane chloride movement by gerbil prestin (SLC26a5.

Directory of Open Access Journals (Sweden)

Sheng Zhong

Full Text Available Chloride is the major anion in cells, with many diseases arising from disordered Cl- regulation. For the non-invasive investigation of Cl- flux, YFP-H148Q and its derivatives chameleon and Cl-Sensor previously were introduced as genetically encoded chloride indicators. Neither the Cl- sensitivity nor the pH-susceptibility of these modifications to YFP is optimal for precise measurements of Cl- under physiological conditions. Furthermore, the relatively poor photostability of YFP derivatives hinders their application for dynamic and quantitative Cl- measurements. Dynamic and accurate measurement of physiological concentrations of chloride would significantly affect our ability to study effects of chloride on cellular events.In this study, we developed a series of YFP derivatives to remove pH interference, increase photostability and enhance chloride sensitivity. The final product, EYFP-F46L/Q69K/H148Q/I152L/V163S/S175G/S205V/A206K (monomeric Cl-YFP, has a chloride Kd of 14 mM and pKa of 5.9. The bleach time constant of 175 seconds is over 15-fold greater than wild-type EYFP. We have used the sensor fused to the transmembrane protein prestin (gerbil prestin, SLC26a5, and shown for the first time physiological (mM chloride flux in HEK cells expressing this protein. This modified fluorescent protein will facilitate investigations of dynamics of chloride ions and their mediation of cell function.Modifications to YFP (EYFP-F46L/Q69K/H148Q/I152L/V163S/S175G/S205V/A206K (monomeric Cl-YFP results in a photostable fluorescent protein that allows measurement of physiological changes in chloride concentration while remaining minimally affected by changes in pH.

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

International Nuclear Information System (INIS)

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

1980-01-01

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

Surface chloride salt formation on Space Shuttle exhaust alumina

Science.gov (United States)

Cofer, W. R., III; Pellett, G. L.; Sebacher, D. I.; Wakelyn, N. T.

1984-01-01

Aluminum oxide samples from the exhaust of Space Shuttle launches STS-1, STS-4, STS-5, and STS-6 were collected from surfaces on or around the launch pad complex and chemically analyzed. The results indicate that the particulate solid-propellant rocket motor (SRM) alumina was heavily chlorided. Concentrations of water-soluble aluminum (III) ion were large, suggesting that the surface of the SRM alumina particles was rendered soluble by prior reactions with HCl and H2O in the SRM exhaust cloud. These results suggest that Space Shuttle exhaust alumina particles are good sites for nucleation and condensation of atmospheric water. Laboratory experiments conducted at 220 C suggest that partial surface chloriding of alumina may occur in hot Space Shuttle exhaust plumes.

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

International Nuclear Information System (INIS)

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

2007-01-01

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

The inhibition of positronium by the chloride ion in water and the positron: Chloride reaction

International Nuclear Information System (INIS)

Beling, C.D.; Smith, F.A.

1983-01-01

A discussion is made of existing theories of Ps inhibition in the presence of Cl - ions. Our favoured interpretation of the data uses the thermalised pre-solvated positron as a common precursor of Ps and e + Cl - . Consideration is given to the prevention of solvation by the strong electric fields in the vicinity of Cl - ions, assuming best estimates for the solvation time, positron mobility and intermolecular spacing. An expression for the Ps inhibition constant K is derived on the basis of diffusive capture. The observed enhancement of Ps yield at higher Cl - concentrations is attributed to the scavenging by the Cl - ion of highly mobile species such as H 2 + O within times approx.=10 -14 s. Dissociation between e + Cl - and the solvated state esub(s) + is suggested as the cause of the ''missing fraction''. (orig.)

Combined Effect of Initial Curing Temperature and Crack Width on Chloride Penetration in Reinforced Concrete Beams

Directory of Open Access Journals (Sweden)

Elkedrouci Lotfi

2018-01-01

Full Text Available Reinforced concrete (RC structures are gradually being degraded all over the world, largely due to corrosion of the embedded steel bars caused by an attack of chloride penetration. Initial curing would be regarded as one factor influencing chloride diffusion in concrete in combination with cover cracking that is also of great attention for reinforced structures. In this study, a non-steady state diffusion test of chloride ion involving RC beam specimens with a water-to-cement ratio of 0.5, initial curing temperatures of 5°C or 20°C and three types of crack widths ranging from 0 to 0.2mm was performed. Chloride content at 5°C or was determined. The results show that the higher chloride content was obtained in condition of crack width large than 0.1mm with low initial curing temperature and there are no obvious differences in chloride content when the crack width was not larger than 0.1mm.

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

International Nuclear Information System (INIS)

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

1993-01-01

Inductively coupled Argon Plasma Spectrometry is used for the indirect determination of sulphate in iron(III) chloride leach solution of Elliot Lake uranium ores via addition of a known amount of barium ions and analyzing for excess of barium. The ore contains ∼ 7 wt% pyrite, FeS 2 , as the major mineral which oxidizes to generate sulphate during leaching with Fe(III). The effects of pH, the concentrations of Fe(III) and chloride ions and for presence of ethanol in the test samples on the accuracy of analysis are studied. It is found that unlike the Rhodizonate method, removal of iron(III) from or addition of ethanol to the test sample prior to analysis are not required. Linear calibration curves are obtained. (author)

Electrochemical reduction of lanthanum trichloride in a molten equimolar mixture of sodium and potassium chlorides

Energy Technology Data Exchange (ETDEWEB)

Glagolevskaya, A.L.; Kuznetsov, S.A.; Polyakov, E.G.; Stangrit, P.T.

1987-09-20

The authors used linear voltamperometry for the investigation of the mechanism for the cathodic reduction of lanthanum. The mechanism for the cathodic reduction of lanthanum chloride in molten equimolar NaCl-KCl may be seen as consisting of a slow irreversible electrode reaction with a subsequent rapid irreversible chemical reaction. Lanthanum ions in a lower oxidation state were not found upon the prolonged maintenance of metallic lanthanum in molten NaCl-KCl-LaCl/sub 3/. Only an increase in the concentration of lanthanum(III) chloride in the melt was noted. The appearance of oxygen anions in the melt does not lead to a change in the mechanism of the cathodic reduction of lanthanum chloride but reduces the concentration of this chloride due to the formation of lanthanum oxochloride which is insoluble in the melt.

Cerium(terbium, erbium)chloride-choline chloride aqueous systems

International Nuclear Information System (INIS)

Gajfutdinova, R.K.; Zhuravlev, E.F.; Bikbaeva, G.G.; Domrachev, V.N.; Vanskova, G.I.

1985-01-01

To clarify the effect of rare earth nature on mutual solubility of rare earth salts and amines the solubility of solid phases in the systems, consisting of choline chloride, water and cerium, terbium, erbium chlorides, has been studied. It is established, that solubility isotherms of all the systems, testify to the formation of new solid phases of the composition: Ce(Tb, Er)xCl 3 x2C 5 H 14 ONClx3H 2 O. Individuality of new solid phases is proved by DTA method, the composition is confirmed by chemical analysis and data of PMR spectra, for choline chloride and its complexes with rare earth chlorides of the given composition PMR and IR spectra are studied

A Genetically-Encoded YFP Sensor with Enhanced Chloride Sensitivity, Photostability and Reduced pH Interference Demonstrates Augmented Transmembrane Chloride Movement by Gerbil Prestin (SLC26a5)

Science.gov (United States)

Zhong, Sheng; Navaratnam, Dhasakumar; Santos-Sacchi, Joseph

2014-01-01

Background Chloride is the major anion in cells, with many diseases arising from disordered Cl− regulation. For the non-invasive investigation of Cl− flux, YFP-H148Q and its derivatives chameleon and Cl-Sensor previously were introduced as genetically encoded chloride indicators. Neither the Cl− sensitivity nor the pH-susceptibility of these modifications to YFP is optimal for precise measurements of Cl− under physiological conditions. Furthermore, the relatively poor photostability of YFP derivatives hinders their application for dynamic and quantitative Cl− measurements. Dynamic and accurate measurement of physiological concentrations of chloride would significantly affect our ability to study effects of chloride on cellular events. Methodology/Principal Findings In this study, we developed a series of YFP derivatives to remove pH interference, increase photostability and enhance chloride sensitivity. The final product, EYFP-F46L/Q69K/H148Q/I152L/V163S/S175G/S205V/A206K (monomeric Cl-YFP), has a chloride Kd of 14 mM and pKa of 5.9. The bleach time constant of 175 seconds is over 15-fold greater than wild-type EYFP. We have used the sensor fused to the transmembrane protein prestin (gerbil prestin, SLC26a5), and shown for the first time physiological (mM) chloride flux in HEK cells expressing this protein. This modified fluorescent protein will facilitate investigations of dynamics of chloride ions and their mediation of cell function. Conclusions Modifications to YFP (EYFP-F46L/Q69K/H148Q/I152L/V163S/S175G/S205V/A206K (monomeric Cl-YFP) results in a photostable fluorescent protein that allows measurement of physiological changes in chloride concentration while remaining minimally affected by changes in pH. PMID:24901231

Redox reactions in rare earth chloride molten electrolytes

International Nuclear Information System (INIS)

Khokhlov, V.A.; Novoselova, A.V.; Nikolaeva, E.V.; Tkacheva, O.Yu.; Salyulev, A.B.

2007-01-01

Rare earth (REM, Ln) solutions in chloride melts including MCI+LnCl 3 mixtures, where M - alkali metals, were investigated by potentiometry, voltammetry, conductometry in wide concentration and temperature intervals. Findings present complete and trusty information on the valent state of rare earths, structure and composition of complex ions affecting essentially on properties of electrolytes. It is demonstrated that the coexistence of rare earth ions with different oxidation level formed as a result of possible redox reactions: 2Ln 3+ + Ln ↔3Ln 2+ , Ln 2+ + Ln↔2Ln + and nM + + Ln↔nM + Ln n+ appears sharply in thermodynamic and transport properties of molten Ln-LnCl 3 and Ln-LnCl 3 -MCl systems [ru

DETERMINATION OF METAL IONS RELEASED BY STAINLESS ...

African Journals Online (AJOL)

The amounts of cobalt, iron, manganese, nickel and chromium ions released from new and reused stainless steel arch bar used for maxillomandibular fixation was determined in Hank's solutions of different hydrogen and chloride ions concentrations, whole blood serum and phosphate buffered saline (PBS) in vitro, over a ...

Energy use in repairs by cover concrete replacement or silane treatment for extending service life of chloride-exposed concrete structures

Science.gov (United States)

Petcherdchoo, A.

2018-05-01

In this study, the service life of repaired concrete structures under chloride environment is predicted. This prediction is performed by considering the mechanism of chloride ion diffusion using the partial differential equation (PDE) of the Fick’s second law. The one-dimensional PDE cannot simply be solved, when concrete structures are cyclically repaired with cover concrete replacement or silane treatment. The difficulty is encountered in solving position-dependent chloride profile and diffusion coefficient after repairs. In order to remedy the difficulty, the finite difference method is used. By virtue of numerical computation, the position-dependent chloride profile can be treated position by position. And, based on the Crank-Nicolson scheme, a proper formulation embedded with position-dependent diffusion coefficient can be derived. By using the aforementioned idea, position- and time-dependent chloride ion concentration profiles for concrete structures with repairs can be calculated and shown, and their service life can be predicted. Moreover, the use of energy in different repair actions is also considered for comparison. From the study, it is found that repairs can control rebar corrosion and/or concrete cracking depending on repair actions.

A single amino-acid substitution toggles chloride dependence of the alpha-amylase paralog amyrel in Drosophila melanogaster and Drosophila virilis species.

Science.gov (United States)

Claisse, Gaëlle; Feller, Georges; Bonneau, Magalie; Da Lage, Jean-Luc

2016-08-01

In animals, most α-amylases are chloride-dependent enzymes. A chloride ion is required for allosteric activation and is coordinated by one asparagine and two arginine side chains. Whereas the asparagine and one arginine are strictly conserved, the main chloride binding arginine is replaced by a glutamine in some rare instances, resulting in the loss of chloride binding and activation. Amyrel is a distant paralogue of α-amylase in Diptera, which was not characterized biochemically to date. Amyrel shows both substitutions depending on the species. In Drosophila melanogaster, an arginine is present in the sequence but in Drosophila virilis, a glutamine occurs at this position. We have investigated basic enzymological parameters and the dependence to chloride of Amyrel of both species, produced in yeast, and in mutants substituting arginine to glutamine or glutamine to arginine. We found that the amylolytic activity of Amyrel is about thirty times weaker than the classical Drosophila α-amylase, and that the substitution of the arginine by a glutamine in D. melanogaster suppressed the chloride-dependence but was detrimental to activity. In contrast, changing the glutamine into an arginine rendered D. virilis Amyrel chloride-dependent, and interestingly, significantly increased its catalytic efficiency. These results show that the chloride ion is not mandatory for Amyrel but stimulates the reaction rate. The possible phylogenetic origin of the arginine/glutamine substitution is also discussed. Copyright © 2016 Elsevier Ltd. All rights reserved.

Simultaneous identification and quantification by liquid chromatography of benzethonium chloride, methyl paraben and triclosan in commercial products labeled as grapefruit seed extract.

Science.gov (United States)

Avula, B; Dentali, S; Khan, I A

2007-08-01

A HPLC method has been developed which permits the quantification of methyl paraben, benzethonium chloride and triclosan in various samples of grapefruit seed extract (GSE). The best results were obtained with a Phenomenex Gemini C18 column using gradient mobile phase of water (0.1% acetic acid) and acetonitrile (0.1% acetic acid) with a flow rate of 1.0 mL per minute. The detection wavelength was 254 nm for methyl paraben, and 275 nm for benzethonium chloride and triclosan. The main synthetic antimicrobial agent identified in commercial GSE samples was benzethonium chloride in concentrations from 0.29-21.84%. Positive ion electrospray MS of a commercial GSE sample showed a molecular ion at m/z 412 [M+], which matched that of a standard of benzethonium chloride. Triclosan was detected in two samples at 0.009 and 1.13%concentrations; while methyl paraben was not detected in the samples analyzed.

influence of foliar applications of calcium chloride and borax on fruit

African Journals Online (AJOL)

Dr. A Rab

2011-12-16

Dec 16, 2011 ... The influence of foliar application of calcium chloride and borax calcium on fruit skin strength and cracking incidence in litchi (Litchi chinensis Sonn.) fruit was investigated at 25 days interval and also the evaluation of fruit skin calcium and boron contents, skin strength, ion leakage from skin discs and.

Use of supplemental cementitious materials for optimum resistance of concrete to chloride penetration.

Science.gov (United States)

1989-01-01

This study was conducted to determine whether significant improvements could be achieved in the resistance to the penetration by chloride ions of concretes with fly ash or slag by the addition of silica fume with either Type II or Type III cement and...

Conversion of borate ions in liquid phase

International Nuclear Information System (INIS)

Gode, G.K.; Bernare, A.A.

1989-01-01

Isomolar series of aquepus solutions of magnesium chloride and potassium tetraborate at 25 deg C are investigated by the refractometry method. It is established that inderite containing triborate-ion is crystalized from solutions of rather high concentration. In 0.1 M solution reagents form supersaturated solutions with the decreased refractive index against the calculated one. It is supposed that this deviation is caused by partial transformation of tetraborate-ion to triborate-ion under the magnesium ion effect

Application of Triton X-100 coated poly vinyl chloride as new solid phase for preconcentration of Fe3+, Cu2+ and Zn2+ ions and their flame atomic absorption spectrometric determinations

Directory of Open Access Journals (Sweden)

Mehrorang Ghaedi

2010-04-01

Full Text Available A selective, sensitive and efficient method for preconcentration of trace amounts of Cu(II, Fe(II and Zn(II ions based on the uptake of their complexes with 3-((indolin-3-yl(phenylmethylindoline (IYPMI loaded on Triton X-100 coated poly vinyl chloride has been reported. The influences of the analytical parameters including pH, ligand amount, surfactant type and concentration, eluting condition and sample volume on metal ions recovery were investigated. The method has been successfully applied for the extraction of these ions content in some real samples of soil and plants. The extraction efficiency was > 97% with low relative standard deviation (RSD < 2.4% and the preconcentration factor of 90 (5 mL elution volume for a 450 mL of sample volume.

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

International Nuclear Information System (INIS)

Park, Jong-Seok; Kuang, Jia; Gwon, Hui-Jeong; Lim, Youn-Mook; Jeong, Sung-In; Shin, Young-Min; Seob Khil, Myung; Nho, Young-Chang

2013-01-01

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

Foliar application of calcium chloride and borax affects the fruit skin ...

African Journals Online (AJOL)

The influence of foliar application of calcium chloride and borax calcium on fruit skin strength and cracking incidence in litchi (Litchi chinensis Sonn.) fruit was investigated at 25 days interval and also the evaluation of fruit skin calcium and boron contents, skin strength, ion leakage from skin discs and fruit cracking in four ...

Multi-species Ionic Diffusion in Concrete with Account to Interaction Between Ions in the Pore Solution and the Cement Hydrates

DEFF Research Database (Denmark)

Johannesson, Björn

2007-01-01

results concerning the multi-species action during chloride penetration. In the model the chemical interaction between ions in solids and in pore solution is assumed governed by simple ion exchange processes only. The drawback using this approach is that the chemical part is lacking important physical...... relevance in terms of standard solubility thermodynamics. On the other hand the presented model is capable of accurately simulate the well documented peak behavior of the chloride profiles and the measured high content of calcium ions in pore solution under conditions when also chlorides is present...

"In situ" observation of the role of chloride ion binding to monkey green sensitive visual pigment by ATR-FTIR spectroscopy.

Science.gov (United States)

Katayama, Kota; Furutani, Yuji; Iwaki, Masayo; Fukuda, Tetsuya; Imai, Hiroo; Kandori, Hideki

2018-01-31

Long-wavelength-sensitive (LWS) pigment possesses a chloride binding site in its protein moiety. The binding of chloride alters the absorption spectra of LWS; this is known as the chloride effect. Although the two amino acid substitutions of His197 and Lys200 influence the chloride effect, the molecular mechanism of chloride binding, which underlies the spectral tuning, has yet to be clarified. In this study, we applied ATR-FTIR spectroscopy to monkey green (MG) pigment to gain structural information of the chloride binding site. The results suggest that chloride binding stabilizes the β-sheet structure on the extracellular side loop with perturbation of the retinal polyene chain, promotes a hydrogen bonding exchange with the hydroxyl group of Tyr, and alters the protonation state of carboxylate. Combining with the results of the binding analyses of various anions (Br - , I - and NO 3 - ), our findings suggest that the anion binding pocket is organized for only Cl - (or Br - ) to stabilize conformation around the retinal chromophore, which is functionally relevant with absorbing long wavelength light.

Influence of temporal resolution and processing of exposure data on modeling of chloride ingress and reinforcement corrosion in concrete

DEFF Research Database (Denmark)

Flint, Madeleine; Michel, Alexander; Billington, Sarah L.

2014-01-01

a numerical heat and mass transport model that includes full coupling of heat, moisture and ion transport. Heat, moisture, and chloride concentration distributions were passed to a simplified reinforcement corrosion initiation and propagation model. The numerical study indicates that processing and temporal...... resolution of the exposure data has a considerable impact on long-term hygrothermal distribution, chloride ingress, and reinforcement section loss results. Use of time-averaged exposure data in the heat and mass transport model reduces the rate of chloride ingress in concrete and affects prediction...

The Influence of Salt Water on Chloride Penetration in Geopolymer Concrete

Directory of Open Access Journals (Sweden)

Halim Like Novia

2017-01-01

Full Text Available This paper presents the influence of chloride ion penetration in geopolymer concrete. Fly ash as based material for geopolymer concrete was used in this mixture. Fly ash was mixed with sodium hydroxide (NaOH 8 M and sodium silicate (Na2SiO3 as the alkali solution. The sizes of cylindrical specimens were prepared with a diameter of 100 mm and 200 mm high. Some specimens were immersed in salt water at a concentration of 3.5%, and other control specimens were cured in tap water for 30, 60, 90, and 120 days. The mechanical properties were determined with compressive test which was conducted at 28, 30, 60, 90 and 120 days. Some durability tests were performed for porosity, chloride penetration, and pH measurement. It was found that geopolymer concrete has higher compressive strength than concrete made with Ordinary Portland cement (OPC. However, chloride penetration in geopolymer concrete is higher than OPC. The pH measurement showed that geopolymer concrete has less pH than OPC concrete. The porosity of concrete has been found to influence chloride penetration and pH of concrete.

Hydration patterns and salting effects in sodium chloride solution.

Science.gov (United States)

Li, Weifeng; Mu, Yuguang

2011-10-07

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

Photooxidation of chloride by oxide minerals: implications for perchlorate on Mars.

Science.gov (United States)

Schuttlefield, Jennifer D; Sambur, Justin B; Gelwicks, Melissa; Eggleston, Carrick M; Parkinson, B A

2011-11-09

We show that highly oxidizing valence band holes, produced by ultraviolet (UV) illumination of naturally occurring semiconducting minerals, are capable of oxidizing chloride ion to perchlorate in aqueous solutions at higher rates than other known natural perchlorate production processes. Our results support an alternative to atmospheric reactions leading to the formation of high concentrations of perchlorate on Mars.

CPP-603 Chloride Removal System Decontamination and Decommissioning

International Nuclear Information System (INIS)

Moser, C.L.

1993-02-01

The CPP-603 (annex) Chloride Removal System (CRS) Decontamination and Decommissioning (D ampersand D) Project is described in this report. The CRS was used for removing Chloride ions and other contaminants that were suspended in the waters of the underwater fuel storage basins in the CPP-603 Fuel Receiving and Storage Facility (FRSF) from 1975 to 1981. The Environmental Checklist and related documents, facility characterization, decision analysis', and D ampersand D plans' were prepared in 1991. Physical D ampersand D activities were begun in mid summer of 1992 and were completed by the end of November 1992. All process equipment and electrical equipment were removed from the annex following accepted asbestos and radiological contamination removal practices. The D ampersand D activities were performed in a manner such that no radiological health or safety hazard to the public or to personnel at the Idaho National Engineering Laboratory (INEL) occurred

Comparative evaluation of metal ions release from titanium and Ti-6Al-7Nb into bio-fluids

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Lori A Joseph

2009-01-01

Full Text Available Background: The study was designed to investigate the effects of pH, chloride ions and nature of some bio-fluids on the amount of metal ions released from titanium and TiAl 6 Nb 7 plates following incubation in actual and simulated bio-fluids over time. Methods: The amounts of released metal ions from commercially pure titanium (CpTi and TiAl 6 Nb 7 of surgical grade on immersion in 20 mL Hank′s solution of pH 4.0 or 7.0, Hank′s solution of high chloride ions concentration, Whole Blood Serum (WBS and Phosphate Buffered Saline (PBS at 37° C were determined over an incubation time of 20 weeks using atomic absorption spectrophotometry. The levels of released metal ions were compared by two-way ANOVA and Duncan′s post-hoc tests. The amounts of titanium ions released by the samples were analyzed by Pearson′s correlation. Results: TiAl 6 Nb 7 plate showed no release of Ti ions into the test solutions until after 12 weeks of incubation, while Ti ions were released from the CpTi plate from the 1 day immersion time. The re-lease of measurable amount of Al ions from TiAl 6 Nb 7 was after 12 weeks of incubation. The rate of release of Ti and Al ions from the samples increased initially with incubation time and then stabilized due to adsorption-desorption equilibrium. Conclusion: The results showed that variations in pH and chloride ions of the test media has a sig-nificant effect on the amounts of Ti ions released, while increase in chloride ions concentration sig-nificantly elevates the release of Al ions into the bio-fluids.

Chloride ingress prediction

DEFF Research Database (Denmark)

Frederiksen, Jens Mejer; Geiker, Mette Rica

2008-01-01

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

MAPbI2.9-xBrxCl0.1 hybrid halide perovskites: Shedding light on the effect of chloride and bromide ions on structural and photoluminescence properties

Science.gov (United States)

Atourki, Lahoucine; Vega, Erika; Marí, Bernabé; Mollar, Miguel; Ait Ahsaine, Hassan; Bouabid, Khalid; Ihlal, Ahmed

2016-12-01

The optical and structural properties of CH3NH3PbI3 can be adjusted by introducing other extrinsic ions such as chloride and bromide. In this work, mixed bromide iodide lead perovskites with a 10% fraction of chloride were prepared from methylamine, lead nitrate and the corresponding hydro acid (X = I, Br, Cl). The effect of bromide and chloride incorporation on different properties of perovskite thin film was investigated. The Pawley fit method indicates the formation of the iodide halide MAPbI3 Pm-3 m cubic phase for x = 0 and the tetragonal P4/mmm phase for x ≥ 0.3. All deposited films showed a strong absorbance in the UV-vis range. The band gap values were estimated from absorbance measurements. It was found that the onset of the absorption edge for MAPbI2.9-xBrxCl0.1 thin film perovskites ranges between 1.60 and 1.80 eV. Moreover, it was found that both Cl and Br affect the PL emission of the mixed halide lead perovskite, the MAPbI2.9-xBrxCl0.1 films displayed intermediate values from 730 nm (MAPbI2.2Br0.7Cl0.1) to 770 nm (MAPbI2.6Br0.3Cl0.1).

Ion-exchange concentration of inorganic anions from aqueous solution

Directory of Open Access Journals (Sweden)

L. P. Bondareva

2016-01-01

Full Text Available Monitoring of natural waters in the present time - consuming process, the accuracy of which is influenced by many factors: the composition of water, the presence of impurities and "interfering" components. The water sample preparation process includes the step of concentration and separation of ions determined. The most versatile, efficient, and frequently used method is the concentration of inorganic anions from aqueous solutions by ion exchanger, which can optimize the composition of water to the optimal for identification and quantitative determination of anions. The characteristics of sorption chloride, nitrate and sulfate ions of basic anion exchange resin AВ-17 and Purolite A430 were compared in the article. The constants of protolysis of ion exchangers both AB 17 and Purolite A430 are the same and equal 0.037 ± 0,002. The value of total capacity (POE Purolite A430 was 4.3 mmol/g, AB 17 – 3.4 mmol/g. The studied ion exchangers have the same type of ionic groups – quaternary ammonium, but their number and denotes differ. The number of quaternary ammonium groups is higher in Purolite A430, respectively the number of absorbed anions of these ion exchanger is higher. The values of dynamic exchange capacity (DOE of ion exchanger Purolite A430 is higher than these values of AB-17 and equal to 1.48 ± 0.03 mmol / dm3 for chloride ion, 1.50 ± 0.03 mmol / dm3 for nitrate ion, 1.62 ± 0.03 mmol / dm3 for sulfate ion. The values of the POE and DOE of anion-exchange resins Purolite A430 and AV-17 and the characteristics of the individual sorption of chloride, nitrate, sulfate ions showed an advantage of the Purolite for the concentrationing of anions. It is found that times of anions sorption from triple-anion solutions by Purolite A430 are significantly different for different anions, and these times are close for anion-exchanger AV-17. It proves the possibility of quantitative separation and concentration by anion-exchanger Purolite A430.

Determination of anionic concentrations in ground water samples using ion chromatography

International Nuclear Information System (INIS)

Prathibha, P.; Saradhi, I.V.; Pandit, G.G.; Puranik, V.D.

2011-01-01

Ion chromatography is a powerful separation technique for the quantitative measurement of anions in aqueous samples as well as in soil, sediment and air particulate samples leached in aqueous solutions. Ion chromatographic technique is developed by making use of suppressed ion conductivity detection (Small et.al.,1975) and it is a rapid multi ion analysis technique. The time, processing and effort required for the analysis of anions is much less compared to other techniques available such as ion selective electrode technique. In the present paper ground water samples collected around New BARC campus, Visakhapatnam are analyzed for anions using Ion chromatograph. The data generated will establish the current baseline status of the ionic contaminants in the study area. Groundwater samples are collected at 13 locations around BARC Vizag campus covering 30 km radius in September, 2009, April and July, 2010. The water samples include samples from hand pump and open wells in villages. The water samples are analyzed for fluoride, chloride, nitrate and sulphate using Metrohm make Ion chromatograph. The fluoride concentration in samples varied from 0.22 to 1.26 ppm, chloride from 18.7 to 810.9, nitrate from 1.34 to 378.5 ppm and sulphate from 13.29 to 250.69 ppm. No significant seasonal variations are observed in the samples collected from various locations except chloride at two locations. Ions Chromatograph is found to be a useful tool for simultaneous analysis of environmental samples with good accuracy where the concentrations of anions vary within an order of magnitude among them themselves. (author)

Atmospheric pressure ionization of chlorinated ethanes in ion mobility spectrometry and mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Ewing, Robert G.; Atkinson, David A.; Benson, Michael T.

2015-05-16

This study investigates the APCI mechanisms associated with chlorinated ethanes in an attempt to define conditions under which unique pseudo-molecular adducts, in addition to chloride ion, can be produced for analytical measurements using IMS and MS. The ionization chemistry of chlorinated compounds typically leads to the detection of only the halide ions. Using molecular modeling, which provides insights into the ion formation and relative binding energies, predictions for the formation of pseudo-molecular adducts are postulated. Predicted structures of the chloride ion with multiple hydrogens on the ethane backbone was supported by the observation of specific pseudo-molecular adducts in IMS and MS spectra. With the proper instrumental conditions, such as short reaction times and low temp.

Liquid-liquid extraction of ion-association complexes of cobalt(II-4-(2-pyridylazoresorcinol with ditetrazolium salts

Directory of Open Access Journals (Sweden)

Divarova Vidka V.

2015-01-01

Full Text Available The formation and liquid-liquid extraction of ion-association complexes between Co(II-4-(2-Pyridylazoresorcinol (PAR anionic chelates and cations of three ditetrazolium chlorides were studied: Blue Tetrazolium chloride (BTC, Neotetrazolium chloride (NTC and Nitro Blue Tetrazolium chloride (NBT. The optimum conditions for the formation and solvent extraction of the ion-association comlpex chelates were determined. It has been found that in the systems of Co(II-PAR-DTS, the reactants are reacted in molar ratios 1:2:1 and the general formula of complexes was suggested. The extraction equilibria were investigated and quantitatively characterized by the equilibrium constants and the recovery factors. The analytical characteristics of the complexes were calculated.

Effect of chlorides on the corrosion behaviour of mild steel

International Nuclear Information System (INIS)

Harada, Kazuyuki; Shimada, Minoru

1980-01-01

In PWR's steam generators, ''denting'' resulted from corrosion of support plate material, carbon steel is an important problem. The role of chlorides in corrosion acceleration of mild steel was studied. Corrosion tests were conducted at temperature from 100 0 C to 280 0 C in deaerated solutions of NaCl and MgCl 2 which are main content of sea water. 1) Solution of MgCl 2 was more corrosive than that of NaCl. The more increased in concentration of each chloride solution, the more corrosive in MgCl 2 soln. but the less corrosive in NaCl soln. 2) The rate of corrosion in the mixed solution of NaCl and MgCl 2 was governed by the concentration of MgCl 2 soln. The corrosion behaviour in sea water was suggested to be not controlled by NaCl but by MgCl 2 . 3) Acidification of MgCl 2 soln. could be evaluated by experiment at 100 0 C, the degree of acidification increased with increasing the concentration. However, the value of pH during corrosion was kept constant by the concentration of dissolved Fe 2+ ions. 4) The corrosion acceleration by MgCl 2 soln. was arised not only from acidification by the solution itself but from continuous supplementation of H + ions with the hydrolysis of dissolved Fe 2+ ions. This autocatalytic corrosion process not exhausting acid was characterized with the corrosion in closed system such as in crevice. In addition to acidification of MgCl 2 soln., the formation of non-protective magnetite film by Mg 2+ ion was estimated to be a reason of accelerated corrosion. (author)

Environmental and energy gains from using molten magnesium–sodium–potassium chlorides for electro-metallisation of refractory metal oxides

Directory of Open Access Journals (Sweden)

Wei Li

2015-12-01

Full Text Available The molten eutectic mixture of magnesium, sodium and potassium chlorides (MgCl2–NaCl–KCl has inappreciable solubility for oxide ions, and can help disengage a carbon anode from the oxide ions generated at a metal oxide cathode, and effectively avoid carbon dioxide formation. This “disengaging strategy” was successfully demonstrated in electro-reduction of solid oxides of zirconium and tantalum. It has led to significantly higher current efficiency (93%, and lower energy consumption (1.4 kW h kg−1 in electrolysis of tantalum oxide to tantalum metal compared to the conventional electrolysis in molten calcium chloride (e.g. 78% and 2.4 kW h/kg-Ta.

Application of ion chromatography in the analysis of metals

International Nuclear Information System (INIS)

Doepke, T.; Braun, N.; Wuensch, G.

1992-01-01

Methods for the determination of chloride in molybdenum, tungsten, niobium and tantalum and of phosphorus in molybdenum and tungsten are presented. After oxidative digestion the analytes are separated from the matrix and accumulated in a small volume of liquid. Unsuppressed ion chromatography serves as the final determination method. The trace-matrix-separation and enrichment of chloride is largely independent of the kind of matrix. The procedure is therefore also applicable to concentrated solutions of various salts. A closed system ensures chloride blanks around 0.2 ppm and detection limits in the higher ppb range. A modification allows an enrichment of bromide and the simultaneous determination of chloride and bromide. (orig.) [de

Pourbaix diagrams of actinides in molten chlorides using an indicating electrode for oxide ion activity

International Nuclear Information System (INIS)

Lambertin, D.; Lacquement, J.

2000-01-01

Pyrochemical separation methods using high temperature molten salt media could emerge as promising and valuable routes compared with aqueous methods for separation and transmutation strategies for long-lived radionuclides. A good knowledge of the molten salt chemistry is essential for controlling these separations, and elementary data are required for molten halide salts, which can be readily provided by electrochemical methods. Applying the chemical principles of aqueous solutions to the molten salt media, Pourbaix diagrams - called in this case potential-oxo-acidity (pO 2- ) - can be plotted. They offer a rapid and comprehensive view of the thermodynamic properties of selected elements in a solvent of interest. Two methods are available for preparing these diagrams. The first is based on available thermodynamic data on pure element oxide (and oxychloride) compounds and on element chloride activity coefficients in melt (which can be electrochemically determined). In this method, we consider the oxide anion exchange reactions between the pure compounds, water and hydrogen chloride. The second method is a direct and experimental determination of the oxo-acidic properties of the studied element chlorides in melts. Use of an Yttria-Stabilised Zirconia Membrane (YSZM) electrode (oxide anion selective electrode) helps determine the nature of the stable oxide compounds in melts as well as their stabilities. The YSZM is used with a silver/silver chloride reference system, and was developed 25 years ago. Two examples of Potential-acidity diagrams. Employing the first method and the determination of the standard potential of plutonium in LiCl-KCl and NaCl-KCl eutectic mixtures, potential-oxo-acidity diagrams were plotted for these melts at various temperatures. It was found that the stability domain for plutonium chloride depends on the melt composition (influence of oxide anion solvation). We also used the Omega acidity function - based on reaction (1) - which is a

Solvent effects on the kinetics of the chlorine isotopic exchange reaction between chloride ion and O,O-diphenyl phosphorochloridate or O,O-diphenyl phosphorchloridothioate

International Nuclear Information System (INIS)

Mikolajczyk, M.; Slebocka-Tilk, H.; Reimschussel, W.

1982-01-01

The effect of solvent on the kinetics of the chlorine isotopic exchange reaction between 36 Cl- ions and O,O-diphenyl phosphorochloridate or O,O-diphenyl phosphorochloridothioate has been investigated in nitromethane, acetonitrile, propylene carbonate, benzonitrile, nitrobenzene, and hexamethyl-phosphoric triamide. The rate constants decrease with increasing electrophilicity of the solvent. A good correlation between the logarithm of the rate constants and acceptor number (AN) of the solvent was obtained with identical slopes for reactions with phosphoryl and thiophosporyl compounds. The slopes for the dependence of ΔH or TΔS vs. AN for chlorine isotopic exchange in (PHO) 2 pace are opposite those for the exchange reaction in (PHO) 2 PSCl, so a constant ratio of k/sub p=O//k/sub p=s/ is observed, resulting from compensation of ΔH by ΔS. The effect of solvent on the initial state (from solubility measurements) and the transition state of the reaction between (PhO) 2 PSCl and the Cl- ion was evaluated. Changes of solvation of (PHO) 2 PSCE have practically no effect on the kinetics of the reactions. Changes of solvation of the chloride ion and of the transition state primarily influence the rate constants and activation parameters of the investigated isotopic-exchange reaction

Contribution to the study of the mechanism of extraction of uranyl chloride by long chain aliphatic amines

International Nuclear Information System (INIS)

Rubinstein, G.R.

1965-06-01

After having studied and developed the mechanisms which may 'a priori' explain the extraction process (co-ordination, ion association or intermediate mechanism), experience shows that ion association only should be taken into consideration. The structure of the organic complex of uranyl chloride has been defined on the basis of the study of the variation of the distribution coefficient of uranium between the two phases at the equilibrium as a function of successively the activity of Cl - ions in the aqueous phase, the concentration of amine salt in the organic phase and finally of the concentration of uranium in the aqueous phase. The plotting of the results in bi-logarithmic co-ordinates enables us to propose the following formula for the extracted compound: UO 2 Cl 4 -- (NR 3 H + ) 2 . The calculation of the equilibrium constant of formation of the organic compound of uranyl chloride has been possible in the case of diluted solutions of uranium only. (author) [fr

Electrolytic process to produce sodium hypochlorite using sodium ion conductive ceramic membranes

Science.gov (United States)

Balagopal, Shekar; Malhotra, Vinod; Pendleton, Justin; Reid, Kathy Jo

2012-09-18

An electrochemical process for the production of sodium hypochlorite is disclosed. The process may potentially be used to produce sodium hypochlorite from seawater or low purity un-softened or NaCl-based salt solutions. The process utilizes a sodium ion conductive ceramic membrane, such as membranes based on NASICON-type materials, in an electrolytic cell. In the process, water is reduced at a cathode to form hydroxyl ions and hydrogen gas. Chloride ions from a sodium chloride solution are oxidized in the anolyte compartment to produce chlorine gas which reacts with water to produce hypochlorous and hydrochloric acid. Sodium ions are transported from the anolyte compartment to the catholyte compartment across the sodium ion conductive ceramic membrane. Sodium hydroxide is transported from the catholyte compartment to the anolyte compartment to produce sodium hypochlorite within the anolyte compartment.

Determination of nitrite, nitrate, bromide, and iodide in seawater by ion chromatography with UV detection using dilauryldimethylammonium-coated monolithic ODS columns and sodium chloride as an eluent.

Science.gov (United States)

Ito, Kazuaki; Nomura, Ryosuke; Fujii, Takuya; Tanaka, Masahito; Tsumura, Tomoaki; Shibata, Hiroyuki; Hirokawa, Takeshi

2012-11-01

A method was developed for determination of inorganic anions, including nitrite (NO(2)(-)), nitrate (NO(3)(-)), bromide (Br(-)), and iodide (I(-)), in seawater by ion chromatography (IC). The IC system used two dilauryldimethylammonium bromide (DDAB)-coated monolithic ODS columns (50 × 4.6 mm i.d. and 100 × 4.6 mm i.d.) connected in series for separation of the ions. Aqueous NaCl (0.5 mol/L; flow rate, 3 mL/min) containing 5 mmol/L phosphate buffer (pH 5) was used as the eluent, and detection was with a UV detector at 225 nm. The monolithic ODS columns were coated and equilibrated with a 1-mmol/L DDAB solution (in H(2)O/methanol, 90:10 v/v). The hydrophilic ions (NO(2)(-), NO(3)(-), and Br(-)) were separated within 3 min and the retention time of I(-) was 16 min. No interferences from matrix ions, such as chloride and sulfate ions, were observed in 35 ‰ artificial seawater. The detection limits were 0.6 μg/L for NO(2)(-), 1.1 μg/L for NO(3)(-), 70 μg/L for Br(-), and 1.6 μg/L for I(-) with a 200-μL sample injection. The performance of the coated columns was maintained without addition of DDAB in the eluent. The IC system was successfully applied to real seawater samples with recovery rates of 94-108 % for all ions.

Accession of non-nitrogenous ions dissolved in rainwater to soils in Victoria

Energy Technology Data Exchange (ETDEWEB)

Hutton, J T; Leslie, T I

1958-01-01

Analyses of rainwater samples from 24 stations in Victoria have shown that with increasing distance from the coast there is a sharp decrease in the influence of the ocean on the nature of the dissolved ions. About 150 miles inland the ionic ratio of sodium to potassium falls below 10, that of sodium to chloride exceeds unity, and calcium becomes the dominant cation. This is considered to reflect the influence of terrestrial material such as the dry surface of soils. As soils also contain sodium and chloride ions, the common assumption that all the chloride in the rain is derived from the ocean is unjustified, hence calculations of the net accession of salts are unwarranted. In southern Australia, sulphate ions are present in much smaller amounts than in other countries and this may contribute to the observed deficiencies of sulphur in plant nutrition. Details are given of the method of collecting the rainwater and of its analysis.

Field experiment on multicomponent ion exchange in a sandy aquifer

International Nuclear Information System (INIS)

Bjerg, P.L.; Christensen, T.H.

1990-01-01

A field experiment is performed in a sandy aquifer in order to study ion exchange processes and multicomponent solute transport modeling. An injection of groundwater spiked with sodium and potassium chloride was performed over a continuous period of 37 days. The plume is monitored by sampling 350 filters in a spatial grid. The sampling aims at establishing compound (calcium, magnesium, potassium, sodium, chloride) breakthrough curves at various filters 15 to 100 m from the point of injection and areal distribution maps at various cross sections from 0 to 200 m from the point of injection. A three-dimensional multicomponent solute transport model will be used to model the field experiments. The chemical model includes cation exchange, precipitation, dissolution, complexation, ionic strength and the carbonate system. Preliminary results from plume monitoring show that the plume migration is relatively well controlled considering the scale and conditions of the experiment. The transverse dispersion is small causing less dilution than expected. The ion exchange processes have an important influence on the plume composition. Retardation of the injected ions is substantial, especially for potassium. Calcium exhibits a substantial peak following chloride due to release from the ion exchange sites on the sediment. (Author) (8 refs., 5 figs., tab.)

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

International Nuclear Information System (INIS)

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

2013-01-01

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

Chloride Test

Science.gov (United States)

... metabolic acidosis ) or when a person hyperventilates (causing respiratory alkalosis ). A decreased level of blood chloride (called hypochloremia) ... disease , emphysema or other chronic lung diseases (causing respiratory ... metabolic alkalosis). An increased level of urine chloride can indicate ...

[Determination of short chain chlorinated paraffins in polyvinyl chloride plastics by gas chromatography-negative chemical ion/mass spectrometry].

Science.gov (United States)

Xing, Yuanna; Lin, Zhihui; Feng, Anhong; Wang, Xin; Gong, Yemeng; Chen, Zeyong

2015-02-01

A novel method was established to determine short chain chlorinated paraffins (SC-CPs) in polyvinyl chloride (PVC) plastics by gas chromatography-negative chemical ion/mass spectrometry (GC-NCI/MS). Ultrasonic extraction was used to extract SCCPs from PVC plastics. The optimal extraction time was 1.5 h, and concentrated sulfuric acid was adopted to purify the extracted solution. Finally, SCCPs in a sample were detected by GC-NCI/MS at 160 C and with methane reagent gas at 1. 5 mL/min. This method was not influenced by medium chain chlorinated paraffins (MCCPs) in the sample, and accurate quantitation was made for SCCPs. Twelve batches of samples were analyzed and SCCPs were detected in each batch with the contents from 0. 3 x 10(2)mg/kg to 3. 5 x 10(4)mg/kg. With respect to European limitation of SC-CPs (1%), four batches of samples did not comply with the European regulation, and they accounted for 33. 3%. Obviously, high SCCPs risk was presented in PVC plastics.

The rechargeable aluminum-ion battery

KAUST Repository

Jayaprakash, N.; Das, S. K.; Archer, L. A.

2011-01-01

We report a novel aluminium-ion rechargeable battery comprised of an electrolyte containing AlCl3 in the ionic liquid, 1-ethyl-3-methylimidazolium chloride, and a V2O5 nano-wire cathode against an aluminium metal anode. The battery delivered a

Atomistic Modeling of Ion Conduction through the Voltage-Sensing Domain of the Shaker K+ Ion Channel.

Science.gov (United States)

Wood, Mona L; Freites, J Alfredo; Tombola, Francesco; Tobias, Douglas J

2017-04-20

Voltage-sensing domains (VSDs) sense changes in the membrane electrostatic potential and, through conformational changes, regulate a specific function. The VSDs of wild-type voltage-dependent K + , Na + , and Ca 2+ channels do not conduct ions, but they can become ion-permeable through pathological mutations in the VSD. Relatively little is known about the underlying mechanisms of conduction through VSDs. The most detailed studies have been performed on Shaker K + channel variants in which ion conduction through the VSD is manifested in electrophysiology experiments as a voltage-dependent inward current, the so-called omega current, which appears when the VSDs are in their resting state conformation. Only monovalent cations appear to permeate the Shaker VSD via a pathway that is believed to be, at least in part, the same as that followed by the S4 basic side chains during voltage-dependent activation. We performed μs-time scale atomistic molecular dynamics simulations of a cation-conducting variant of the Shaker VSD under applied electric fields in an experimentally validated resting-state conformation, embedded in a lipid bilayer surrounded by solutions containing guanidinium chloride or potassium chloride. Our simulations provide insights into the Shaker VSD permeation pathway, the protein-ion interactions that control permeation kinetics, and the mechanism of voltage-dependent activation of voltage-gated ion channels.

Role of sulfate, chloride, and nitrate anions on the degradation of fluoroquinolone antibiotics by photoelectro-Fenton.

Science.gov (United States)

Villegas-Guzman, Paola; Hofer, Florian; Silva-Agredo, Javier; Torres-Palma, Ricardo A

2017-12-01

Taking ciprofloxacin (CIP) as a fluoroquinolone antibiotic model, this work explores the role of common anions (sulfate, nitrate, and chloride) during the application of photoelectro-Fenton (PEF) at natural pH to degrade this type of compound in water. The system was composed of an IrO 2 anode, Ti, or gas diffusion electrode (GDE) as cathode, Fe 2+ , and UV (254 nm). To determine the implications of these anions, the degradation pathway and efficiency of the PEF sub-processes (UV photolysis, anodic oxidation, and electro-Fenton at natural pH) were studied in the individual presence of the anions. The results highlight that degradation routes and kinetics are strongly dependent on electrolytes. When chloride and nitrate ions were present, indirect electro-chemical oxidation was identified by electro-generated HOCl and nitrogenated oxidative species, respectively. Additionally, direct photolysis and direct oxidation at the anode surface were identified as degradation routes. As a consequence of the different pathways, six primary CIP by-products were identified. Therefore, a scheme was proposed representing the pathways involved in the degradation of CIP when submitted to PEF in water with chloride, nitrate, and sulfate ions, showing the complexity of this process. Promoted by individual and synergistic actions of this process, the PEF system leads to a complete elimination of CIP with total removal of antibiotic activity against Staphylococcus aureus and Escherichia coli, and significant mineralization. Finally, the role of the anions was tested in seawater containing CIP, in which the positive contributions of the anions were partially suppressed by its OH radical scavenger action. The findings are of interest for the understanding of the degradation of antibiotics via the PEF process in different matrices containing sulfate, nitrate, and chloride ions.

Dielectrophoretic analysis of changes in cytoplasmic ion levels due to ion channel blocker action reveals underlying differences between drug-sensitive and multidrug-resistant leukaemic cells

International Nuclear Information System (INIS)

Duncan, L; Shelmerdine, H; Hughes, M P; Coley, H M; Huebner, Y; Labeed, F H

2008-01-01

Dielectrophoresis (DEP)-the motion of particles in non-uniform AC fields-has been used in the investigation of cell electrophysiology. The technique offers the advantages of rapid determination of the conductance and capacitance of membrane and cytoplasm. However, it is unable to directly determine the ionic strengths of individual cytoplasmic ions, which has potentially limited its application in assessing cell composition. In this paper, we demonstrate how dielectrophoresis can be used to investigate the cytoplasmic ion composition by using ion channel blocking agents. By blocking key ion transporters individually, it is possible to determine their overall contribution to the free ions in the cytoplasm. We use this technique to evaluate the relative contributions of chloride, potassium and calcium ions to the cytoplasmic conductivities of drug sensitive and resistant myelogenous leukaemic (K562) cells in order to determine the contributions of individual ion channel activity in mediating multi-drug resistance in cancer. Results indicate that whilst K + and Ca 2+ levels were extremely similar between sensitive and resistant lines, levels of Cl - were elevated by three times to that in the resistant line, implying increased chloride channel activity. This result is in line with current theories of MDR, and validates the use of ion channel blockers with DEP to investigate ion channel function. (note)

40 CFR 61.65 - Emission standard for ethylene dichloride, vinyl chloride and polyvinyl chloride plants.

Science.gov (United States)

2010-07-01

... dichloride, vinyl chloride and polyvinyl chloride plants. 61.65 Section 61.65 Protection of Environment... AIR POLLUTANTS National Emission Standard for Vinyl Chloride § 61.65 Emission standard for ethylene dichloride, vinyl chloride and polyvinyl chloride plants. An owner or operator of an ethylene dichloride...

Estimating the chloride transport in cement paste

Directory of Open Access Journals (Sweden)

Princigallo, A.

2012-06-01

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

Se ha desarrollado un método para medir el coeficiente de difusión de los iones cloruro en la pasta de cemento, partiendo de una aplicación analítica de la segunda ley de Fick en un sistema de coordinadas cilíndrico. Este método, que es natural, demostró ser capaz de producir resultados de difusividad en tan solo un mes. Se consiguió reducir el tiempo de ensayo mediante el aprovechamiento de la tridimensionalidad del flujo desde el exterior al interior de la probeta. A fin de determinar la concentración de saturación, se sometieron las pastas de cemento Portland a una disolución de cloruros concentrada. Este método resultó ser útil en el estudio de los cambios del coeficiente de difusión de la pasta de cemento provocados por las reacciones de hidratación que tienen lugar en esta.

Synthesis of ion-exchange resin for selective thorium and uranyl ions sorption

Science.gov (United States)

Konovalov, Konstantin; Sachkov, Victor

2017-11-01

In this work, the method of ion-exchange resin synthesis selective to radionuclides (uranium and thorium) is presented. The method includes synthesis of polymeric styrene-divinylbenzene macroporous matrix with size of 0.1-0.2 mm, and its subsequent transformation by nitration and then reduction by tin (II) chloride. For passivation of active primary amines partially oxidation by oxygen from air is used. Obtained ion-exchange resin has ratio of sorption sum U+Th to sorption sum of other total rare-earth elements as 1:1.88 at ratio of solid to liquid phase 1:200. The proposed method of ion-exchange resin synthesis is scaled-up for laboratory reactors with volume of 5 and 50 liters.

A Windows-95 based DAS software for the determination of chloride and fluoride in MOX fuel samples by pyrohydrolysis-ISE method

Energy Technology Data Exchange (ETDEWEB)

Govindan, R; Kulkarni, Atul; Sivashankaran, G; Raul, Seema; Behere, P G; Mallik, G K; Bhargava, V K; Kamath, H S [Advanced Fuel Fabrication Facility, Bhabha Atomic Research Centre, Tarapur (India)

1999-01-01

A Windows-95 based Data Acquisition System (DAS) software has been developed to determine chloride and fluoride in MOX (Mixed Oxide) fuel pellets by pyrohydrolysis followed by Ion Selective Electrodes (ISE). The DAS software controls the furnace remotely and acquires data related to ion-85 ion analyser through RS-232C serial port. This results in ease of operation of furnace during pyrohydrolysis and storage of measured data from ion-85 ion analyser for future use. (author) 4 refs., 1 fig., 3 tabs.

Optical and electrical characterizations of a single step ion beam milling mesa devices of chloride passivated PbS colloidal quantum dots based film

International Nuclear Information System (INIS)

Hechster, Elad; Sarusi, Gabby; Shapiro, Arthur; Lifshitz, Efrat

2016-01-01

Colloidal Quantum Dots (CQDs) are of increasing interest, thanks to their quantum size effect that gives rise to their usage in various applications, such as biological tagging, solar cells and as the sensitizing layer of night vision devices. Here, we analyze the optical absorbance of chloride passivated PbS CQDs as well as revealing a correlation between their photoluminescence and sizes distribution, using theoretical models and experimental results from the literature. Next, we calculate the CQDs resistivity as a film. Although resistivity can be calculated from sheet resistance measurement using four point probes, such measurement is usually carried-out on the layer’s surface that in most cases has dangling bonds and surface states, which might affect the charges flow and modify the resistivity. Therefore; our approach, which was applied in this work, is to extract the actual resistivity from measurements that are performed along the film’s thickness (z-direction). For this intent, we fabricated gold capped PbS mesas devices using a single step Ion Beam Milling (IBM) process where we milled the gold and the PbS film continually, and then measured the vertical resistance. Knowing the mesas’ dimensions, we calculate the resistivity. To the best of our knowledge, no previous work has extracted, vertically, the resistivity of chloride passivated PbS CQDs using the above method.

Optical and electrical characterizations of a single step ion beam milling mesa devices of chloride passivated PbS colloidal quantum dots based film

Energy Technology Data Exchange (ETDEWEB)

Hechster, Elad, E-mail: elad.hechster@gmail.com; Sarusi, Gabby [Electro-Optics Engineering Unit and Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva, 84100 Israel (Israel); Shapiro, Arthur; Lifshitz, Efrat [Schulich Faculty of Chemistry, Solid State Institute, Russel Berrie Nanotechnology Institute, Technion – Israel Institute of technology, 32000 Haifa (Israel)

2016-07-15

Colloidal Quantum Dots (CQDs) are of increasing interest, thanks to their quantum size effect that gives rise to their usage in various applications, such as biological tagging, solar cells and as the sensitizing layer of night vision devices. Here, we analyze the optical absorbance of chloride passivated PbS CQDs as well as revealing a correlation between their photoluminescence and sizes distribution, using theoretical models and experimental results from the literature. Next, we calculate the CQDs resistivity as a film. Although resistivity can be calculated from sheet resistance measurement using four point probes, such measurement is usually carried-out on the layer’s surface that in most cases has dangling bonds and surface states, which might affect the charges flow and modify the resistivity. Therefore; our approach, which was applied in this work, is to extract the actual resistivity from measurements that are performed along the film’s thickness (z-direction). For this intent, we fabricated gold capped PbS mesas devices using a single step Ion Beam Milling (IBM) process where we milled the gold and the PbS film continually, and then measured the vertical resistance. Knowing the mesas’ dimensions, we calculate the resistivity. To the best of our knowledge, no previous work has extracted, vertically, the resistivity of chloride passivated PbS CQDs using the above method.

Changes in ion transport in inflammatory disease

Directory of Open Access Journals (Sweden)

Eisenhut Michael

2006-03-01

Full Text Available Abstract Ion transport is essential for maintenance of transmembranous and transcellular electric potential, fluid transport and cellular volume. Disturbance of ion transport has been associated with cellular dysfunction, intra and extracellular edema and abnormalities of epithelial surface liquid volume. There is increasing evidence that conditions characterized by an intense local or systemic inflammatory response are associated with abnormal ion transport. This abnormal ion transport has been involved in the pathogenesis of conditions like hypovolemia due to fluid losses, hyponatremia and hypokalemia in diarrhoeal diseases, electrolyte abnormalites in pyelonephritis of early infancy, septicemia induced pulmonary edema, and in hypersecretion and edema induced by inflammatory reactions of the mucosa of the upper respiratory tract. Components of membranous ion transport systems, which have been shown to undergo a change in function during an inflammatory response include the sodium potassium ATPase, the epithelial sodium channel, the Cystic Fibrosis Transmembrane Conductance Regulator and calcium activated chloride channels and the sodium potassium chloride co-transporter. Inflammatory mediators, which influence ion transport are tumor necrosis factor, gamma interferon, interleukins, transforming growth factor, leukotrienes and bradykinin. They trigger the release of specific messengers like prostaglandins, nitric oxide and histamine which alter ion transport system function through specific receptors, intracellular second messengers and protein kinases. This review summarizes data on in vivo measurements of changes in ion transport in acute inflammatory conditions and in vitro studies, which have explored the underlying mechanisms. Potential interventions directed at a correction of the observed abnormalities are discussed.

Nuclear Magnetic Resonance and Elastic Wave Velocity of Chalk Saturated with Brines Containing Divalent Ions

DEFF Research Database (Denmark)

Katika, Konstantina; Alam, Mohammad Monzurul; Fabricius, Ida Lykke

divided into groups of three and each group was saturated either with deionized water, calcite equilibrated water, or sodium chloride, magnesium chloride and calcium chloride solutions of the same ionic strength. Saturation with solutions that contain divalent ions caused major shifts in the distribution...... of the relaxation time. Core samples saturated with calcium chloride solution relaxed slower and those saturated with magnesium chloride solution relaxed faster than the rest of the samples. Along with the changes in relaxation the samples experienced smaller velocities of elastic waves when saturated with MgCl2...

Deconvoluting the memory effect in Pd-catalyzed allylic alkylation; effect of leaving group and added chloride

DEFF Research Database (Denmark)

Fristrup, Peter; Jensen, Thomas; Hoppe, Jakob

2006-01-01

An analysis of product distributions in the Tsuji-Trost reaction indicates that several instances of reported memory effects can be attributed to slow interconversion of the initially formed syn- and anti-[Pd(eta3-allyl)] complexes. Addition of chloride triggers a true memory effect, in which...... the allylic terminus originally bearing the leaving group has a higher reactivity. The latter effect, termed regioretention, can be rationalized by ionization from a palladium complex bearing a chloride ion, forming an unsymmetrically substituted [Pd(eta3-allyl)] complex. DFT calculations verify...

Chloride effect on the early photolysis intermediates of a gecko cone-type visual pigment.

Science.gov (United States)

Lewis, J W; Liang, J; Ebrey, T G; Sheves, M; Kliger, D S

1995-05-02

Nanosecond laser photolysis measurements were conducted on the cone-type visual pigment P521 in digitonin extracts of Tokay gecko (Gekko gekko) retina containing physiological chloride ion levels and also on samples which had been chloride depleted or which contained high levels (4 M) of chloride. Absorbance difference spectra were recorded at a sequence of time delays from 30 ns to 60 microseconds following excitation with a pulse of either 532- or 477-nm actinic light. Global analysis showed the kinetic decay data for gecko pigment P521 to be best fit by two exponential processes under all chloride conditions. The initial photoproduct detected had a broad spectrum characteristic of an equilibrated mixture of a Batho P521 intermediate with its blue-shifted intermediate (BSI P521) decay product. The first exponential process was assigned to the decay of this mixture to the Lumi P521 intermediate. The second exponential process was identified as the decay of Lumi P521 to Meta I P521. The initial photoproduct's spectrum exhibited a strong dependence on chloride concentration, indicating that chloride affects the composition of the equilibrated mixture of Batho P521 and BSI P521. These results suggest that the affinity for chloride is reduced approximately 5-fold in the Batho P521 intermediate and approximately 50-fold in the BSI P521 intermediate. Chloride concentration also affects the apparent decay rate of the equilibrated mixture. When the apparent decay rate is corrected for the composition of the equilibrated mixture, a relatively invariant microscopic rate constant is obtained for BSI decay (k = 1/55 ns-1).(ABSTRACT TRUNCATED AT 250 WORDS)

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

Energy Technology Data Exchange (ETDEWEB)

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

1988-03-01

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

Secondary effects of anion exchange on chloride, sulfate, and lead release: systems approach to corrosion control.

Science.gov (United States)

Willison, Hillary; Boyer, Treavor H

2012-05-01

Water treatment processes can cause secondary changes in water chemistry that alter finished water quality including chloride, sulfate, natural organic matter (NOM), and metal release. Hence, the goal of this research was to provide an improved understanding of the chloride-to-sulfate mass ratio (CSMR) with regards to chloride and sulfate variations at full-scale water treatment plants and corrosion potential under simulated premise plumbing conditions. Laboratory corrosion studies were conducted using Pb-Sn solder/Cu tubing galvanic cells exposed to model waters with low (approx. 5 mg/L Cl(-) and 10 mg/L SO(4)(2-)) and high (approx. 50 mg/L Cl(-) and 100 mg/L SO(4)(2-)) concentrations of chloride and sulfate at a constant CSMR of ≈ 0.5. The role of NOM during corrosion was also evaluated by changing the type of organic material. In addition, full-scale sampling was conducted to quantify the raw water variability of chloride, sulfate, and NOM concentrations and the changes to these parameters from magnetic ion exchange treatment. Test conditions with higher concentrations of chloride and sulfate released significantly more lead than the lower chloride and sulfate test waters. In addition, the source of NOM was a key factor in the amount of lead released with the model organic compounds yielding significantly less lead release than aquatic NOM. Copyright © 2012 Elsevier Ltd. All rights reserved.

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

International Nuclear Information System (INIS)

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

1995-01-01

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

Corrosion inhibition of iron in 0.5 mol L-1 H2SO4 by halide ions

Directory of Open Access Journals (Sweden)

Jeyaprabha C.

2006-01-01

Full Text Available The inhibition effect of halide ions such as iodide, bromide and chloride ions on the corrosion of iron in 0.5 mol L-1 H2SO4 and the adsorption behaviour of these ions on the electrode surface have been studied by polarization and impedance methods. It has been found that the inhibition of nearly 90% has been observed for iodide ions at 2.5 10-3 mol L-1, for bromide ions at 10 10-3 mol L-1 and 80% for chloride ions at 2.5 10-3 mol L-1. The inhibition effect is increased with increase of halide ions concentration in the case of I- and Br- ions, whereas it has decreased in the case of Cl- ion at concentrations higher than 5 10-3 mol L-1. The double layer capacitance values have decreased considerably in the presence of halide ions which indicate that these anions are adsorbed on iron at the corrosion potential.

X-ray diffraction study of choline chloride's β form

International Nuclear Information System (INIS)

Petrouleas, V.; Lemmon, R.M.; Christensen, A.

1978-01-01

The organic salt choline chloride exists in two crystalline polymorphs. One (the α form) is extraordinarily sensitive to ionizing radiation, the other (the β form) is not. The present report describes an x-ray diffraction study of the β form. The structure has been found to be highly disordered face centered cubic. A reasonable least-square refinement of the intensity data has been achieved in the centrosymmetric space group Fm3 or Fm3m by use of a molecular model with restrained bond lengths. The results show that in the β form the electronic density due to the choline cation is closely spaced around the N, so that hydrogen bonding to the chloride is unlikely. Comparison with infrared and NMR data indicates that the disordering is dynamic and can be ascribed to rotations of the choline ion around crystallographic symmetry axes. Possible connections of these results with the radiation stability of the β form are discussed

Determination of metal ions released by stainless steel arch bar into bio-fluids

Directory of Open Access Journals (Sweden)

Lori A. Joseph

2009-04-01

Full Text Available The amounts of cobalt, iron, manganese, nickel and chromium ions released from new and reused stainless steel arch bar used for maxillomandibular fixation was determined in Hank’s solutions of different hydrogen and chloride ions concentrations, whole blood serum and phosphate buffered saline (PBS in vitro, over a six-week immersion time at 37 oC, by atomic absorption spectrophotometry. The corrosion levels of the wires due to effects of media and incubation times in the bio-fluids were compared by Duncan’s two-way ANOVA (P less than 0.05. Pearson’s correlation was used in establishing relationship in the amounts of metal ions released by new and reused arch bars. The study indicated that the reused wires released more ions than new ones at all time points. The variation of pH and chloride ions of the bio-fluids had a significant effect on the amount of Ni, Mn and Cr ions released. Ageing prior use of arch bars significantly increased Ni ions released into the bio-fluids.

Electrodeposition of copper composites from deep eutectic solvents based on choline chloride.

Science.gov (United States)

Abbott, Andrew P; El Ttaib, Khalid; Frisch, Gero; McKenzie, Katy J; Ryder, Karl S

2009-06-07

Here we describe for the first time the electrolytic deposition of copper and copper composites from a solution of the metal chloride salt in either urea-choline chloride, or ethylene glycol-choline chloride based eutectics. We show that the deposition kinetics and thermodynamics are quite unlike those in aqueous solution under comparable conditions and that the copper ion complexation is also different. The mechanism of copper nucleation is studied using chronoamperometry and it is shown that progressive nucleation leads to a bright nano-structured deposit. In contrast, instantaneous nucleation, at lower concentrations of copper ions, leads to a dull deposit. This work also pioneers the use of the electrochemical quartz crystal microbalance (EQCM) to monitor both current efficiency and the inclusion of inert particulates into the copper coatings. This technique allows the first in situ quantification or particulate inclusion. It was found that the composition of composite material was strongly dependent on the amount of species suspended in solution. It was also shown that the majority of material was dragged onto the surface rather than settling on to it. The distribution of the composite material was found to be even throughout the coating. This technology is important because it facilitates deposition of bright copper coatings without co-ligands such as cyanide. The incorporation of micron-sized particulates into ionic liquids has resulted, in one case, in a decrease in viscosity. This observation is both unusual and surprising; we explain this here in terms of an increase in the free volume of the liquid and local solvent perturbation.

Rust Layer Formed on Low Carbon Weathering Steels with Different Mn, Ni Contents in Environment Containing Chloride Ions

Directory of Open Access Journals (Sweden)

Gui-qin FU

2016-11-01

Full Text Available The rusting evolution of low carbon weathering steels with different Mn, Ni contents under a simulated environment containing chloride ions has been investigated to clarify the correlation between Mn, Ni and the rust formed on steels. The results show that Mn contents have little impact on corrosion kinetics of experimental steels. Content increase of Ni both enhances the anti-corrosion performance of steel substrate and the rust. Increasing Ni content is beneficial to forming compact rust. Semi-quantitative XRD phase analysis shows that the quantity ratio of α/γ*（α-FeOOH/(γ-FeOOH+Fe3O4 decreases as Mn content increases but it increases as Ni content increases. Ni enhances rust layer stability but Mn content exceeding 1.06 wt.% is disadvantageous for rust layer stability. The content increase of Mn does not significantly alter the parameters of the polarization curve. However, as Ni contents increases, Ecorr has shifted to the positive along with decreased icorr values indicating smaller corrosion rate especially as Ni content increases from 0.42 wt.% to 1.50 wt.%.DOI: http://dx.doi.org/10.5755/j01.ms.22.4.12844

Extraction of zirconium and hafnium thiocyanates by CH3COCH2CH.(CH3)2-HSCN solvent from chloride medium

International Nuclear Information System (INIS)

Okada, A.T.

1982-01-01

A zirconium-hafnium separation process for application in nuclear industry is presented. The extraction of zirconium and hafnium thiocyanates in chloride medium by hexone-HSCN solvent was studied. The extraction process was developed, varying the parameters, such as, concentrations of the metals, the thiocyanate ion, the sulphate ion and free acidity in aqueous phase. (Author) [pt

Chloride test - blood

Science.gov (United States)

Serum chloride test ... A greater-than-normal level of chloride is called hyperchloremia. It may be due to: Carbonic anhydrase inhibitors (used to treat glaucoma) Diarrhea Metabolic acidosis Respiratory alkalosis (compensated) Renal ...

Chloride in diet

Science.gov (United States)

... this page: //medlineplus.gov/ency/article/002417.htm Chloride in diet To use the sharing features on this page, please enable JavaScript. Chloride is found in many chemicals and other substances ...

Mercuric chloride poisoning

Science.gov (United States)

... page: //medlineplus.gov/ency/article/002474.htm Mercuric chloride poisoning To use the sharing features on this page, please enable JavaScript. Mercuric chloride is a very poisonous form of mercury. It ...

Multilayer membranes of p-sulfonato-calix[8]arene and polyvinylamine and their use for selective enrichment of rare earth metal ions

Energy Technology Data Exchange (ETDEWEB)

Toutianoush, Ali [Institut fuer Physikalische Chemie der Universitaet zu Koeln, Luxemburger Str. 116, D-50939 Cologne (Germany); El-Hashani, Ashraf [Institut fuer Physikalische Chemie der Universitaet zu Koeln, Luxemburger Str. 116, D-50939 Cologne (Germany); Schnepf, Judit [Institut fuer Physikalische Chemie der Universitaet zu Koeln, Luxemburger Str. 116, D-50939 Cologne (Germany); Tieke, Bernd [Institut fuer Physikalische Chemie der Universitaet zu Koeln, Luxemburger Str. 116, D-50939 Cologne (Germany)]. E-mail: Tieke@Uni-Koeln.de

2005-06-30

Using alternating electrostatic layer-by-layer assembly of p-octasulfonato-calix[8]arene and polyvinylamine, multilayer assemblies were built up on porous polymer supports. The resulting composite membranes with ultrathin separation layer were studied on their permeability for various metal chloride salts in aqueous solution. The membranes were permeable for sodium chloride, but much less permeable for divalent metal chlorides such as magnesium and zinc chloride, the theoretical separation factors {alpha} (NaCl/MgCl{sub 2}) and {alpha} (NaCl/ZnCl{sub 2}) being 43 and 20. Rare earth metal chlorides LnCl{sub 3} with Ln being La, Ce, Pr and Sm and the related YCl{sub 3} were strongly rejected from the membrane, the theoretical separation factors {alpha} (NaCl/LaCl{sub 3}) and {alpha} (NaCl/YCl{sub 3}) being 138 and 160, for example. Possible origins for the selective ion transport are discussed in terms of Donnan rejection of the highly charged ions and complex formation of the rare earth metal ions with the p-sulfonato-calixarene units in the membrane.

Multilayer membranes of p-sulfonato-calix[8]arene and polyvinylamine and their use for selective enrichment of rare earth metal ions

International Nuclear Information System (INIS)

Toutianoush, Ali; El-Hashani, Ashraf; Schnepf, Judit; Tieke, Bernd

2005-01-01

Using alternating electrostatic layer-by-layer assembly of p-octasulfonato-calix[8]arene and polyvinylamine, multilayer assemblies were built up on porous polymer supports. The resulting composite membranes with ultrathin separation layer were studied on their permeability for various metal chloride salts in aqueous solution. The membranes were permeable for sodium chloride, but much less permeable for divalent metal chlorides such as magnesium and zinc chloride, the theoretical separation factors α (NaCl/MgCl 2 ) and α (NaCl/ZnCl 2 ) being 43 and 20. Rare earth metal chlorides LnCl 3 with Ln being La, Ce, Pr and Sm and the related YCl 3 were strongly rejected from the membrane, the theoretical separation factors α (NaCl/LaCl 3 ) and α (NaCl/YCl 3 ) being 138 and 160, for example. Possible origins for the selective ion transport are discussed in terms of Donnan rejection of the highly charged ions and complex formation of the rare earth metal ions with the p-sulfonato-calixarene units in the membrane

Chloride removal from vitrification offgas

Energy Technology Data Exchange (ETDEWEB)

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

1995-06-01

This study identified and investigated techniques of selectively purging chlorides from the low-level waste (LLW) vitrification process with the purge stream acceptable for burial on the Hanford Site. Chlorides will be present in high concentration in several individual feeds to the LLW Vitrification Plant. The chlorides are highly volatile in combustion type melters and are readily absorbed by wet scrubbing of the melter offgas. The Tank Waste Remediation System (TWRS) process flow sheets show that the resulting chloride rich scrub solution is recycled back to the melter. The chlorides must be purged from the recycle loop to prevent the buildup of excessively high chloride concentrations.

Chloride removal from vitrification offgas

International Nuclear Information System (INIS)

Slaathaug, E.J.

1995-01-01

This study identified and investigated techniques of selectively purging chlorides from the low-level waste (LLW) vitrification process with the purge stream acceptable for burial on the Hanford Site. Chlorides will be present in high concentration in several individual feeds to the LLW Vitrification Plant. The chlorides are highly volatile in combustion type melters and are readily absorbed by wet scrubbing of the melter offgas. The Tank Waste Remediation System (TWRS) process flow sheets show that the resulting chloride rich scrub solution is recycled back to the melter. The chlorides must be purged from the recycle loop to prevent the buildup of excessively high chloride concentrations

Potentiometric Sensor for Real-Time Monitoring of Multivalent Ion Concentrations in Molten Salt

International Nuclear Information System (INIS)

Zink, Peter A.; Jue, Jan-Fong; Serrano, Brenda E.; Fredrickson, Guy L.; Cowan, Ben F.; Herrmann, Steven D.; Li, Shelly X.

2010-01-01

Electrorefining of spent metallic nuclear fuel in high temperature molten salt systems is a core technology in pyroprocessing, which in turn plays a critical role in the development of advanced fuel cycle technologies. In electrorefining, spent nuclear fuel is treated electrochemically in order to effect separations between uranium, noble metals, and active metals, which include the transuranics. The accumulation of active metals in a lithium chloride-potassium chloride (LiCl-KCl) eutectic molten salt electrolyte occurs at the expense of the UCl3-oxidant concentration in the electrolyte, which must be periodically replenished. Our interests lie with the accumulation of active metals in the molten salt electrolyte. The real-time monitoring of actinide concentrations in the molten salt electrolyte is highly desirable for controlling electrochemical operations and assuring materials control and accountancy. However, real-time monitoring is not possible with current methods for sampling and chemical analysis. A new solid-state electrochemical sensor is being developed for real-time monitoring of actinide ion concentrations in a molten salt electrorefiner. The ultimate function of the sensor is to monitor plutonium concentrations during electrorefining operations, but in this work gadolinium was employed as a surrogate material for plutonium. In a parametric study, polycrystalline sodium beta double-prime alumina (Na-β(double p rime)-alumina) discs and tubes were subject to vapor-phase exchange with gadolinium ions (Gd3+) using a gadolinium chloride salt (GdCl3) as a precursor to produce gadolinium beta double-prime alumina (Gd-β(double p rime)-alumina) samples. Electrochemical impedance spectroscopy and microstructural analysis were performed on the ion-exchanged discs to determine the relationship between ion exchange and Gd3+ ion conductivity. The ion-exchanged tubes were configured as potentiometric sensors in order to monitor real-time Gd3+ ion concentrations in

Foliar application of ascorbic acid mitigates sodium chloride induced stress in eggplant (solanum melongena l.)

International Nuclear Information System (INIS)

Jan, S.; Hamayun, M.

2016-01-01

The current work was designed to test the effect of sodium chloride on germination, seedling establishment, vegetative growth, yield, chemical contents and ionic composition of eggplant. The consequences of foliar application of ascorbic acid (AA) on mitigation of adverse effects of sodium chloride were also tested. The seeds of Solanum melongena were germinated using NaCl (60 mM, 100 mM) and ascorbic acid (100 and 200 mM). High levels of salinity significantly affected the seed germination and seedling fresh and dry weights. Plants grown under salinity stress with foliar application of ascorbic acid showed significant increase in germination percentage and seedlings growth as compare to control plants. Sodium chloride stress showed adverse effects on plant height, root length, number of leaves, leaf area, fresh and dry biomass, total chlorophyll, carbohydrates and proteins as compared to untreated plants. The relative water content, electrolyte leakage were increased and Na+ and K+ ions balance was disturbed in different plant parts. Ascorbic acid (100 and 200ppm) enhanced all the growth parameters affected adversely by sodium chloride stress. (author)

Structure and thermodynamic properties of molten strontium chloride

International Nuclear Information System (INIS)

Pastore, G.; Ballone, P.; Tosi, M.P.; Trieste Univ.

1985-05-01

Self-consistent calculations of pair distribution functions and thermodynamic properties are presented for a pair-potentials model of molten strontium chloride. The calculations extend to a strongly asymmetric ionic liquid an earlier assessment of bridge diagrams in a modified hypernetted chain approach to the liquid structure of alkali halides. Good agreement is found with computer simulation data obtained by de Leeuw with the same set of pair potentials, showing that the present approach incorporates genuine general features of liquid structure theory for multicomponent liquids with strong relative ordering of the component species. It is further shown that the strong correlations between the divalent cations, both in the model and in real molten strontium chloride, can be approximately reproduced on the basis of a simple one-component-plasma model, provided that dielectric screening is allowed for in the real liquid. This allows us to tentatively attribute the significant level of disagreement between a pair potentials model of this liquid and the neutron diffraction data of McGreevy and Mitchell to many-body distortions of the electronic shells of the ions. (author)

The reduction of pertechnetate-99 by stannous chloride

International Nuclear Information System (INIS)

Steigman, J.; Meinken, G.; Richards, P.

1975-01-01

The reduction of pertechnetate-99 by excess stannous chloride in several media was investigated as a possible model for radiopharmaceutical preparations which are based on the reduction of pertechnetate-99m by the same reagent. Polarographic and iodimetric techniques were used to analyze for unreacted stannous ion. It was found that pertechnetate is reduced to the +4 state in a citrate buffer at pH7, to the +3 state in a DTPA buffer at pH4, and possibly to the +4 state in HCl. The reaction in DTPA solution was found to be complete within several minutes. The reduction in the citrate buffer proceeded rapidly to the +5 state, and much more slowly to the +4 state. The implications of these rate studies for the radiopharmaceutical preparations were discussed. Direct potentiometric titrations of pertechnetate-99 with stannous chloride showed that the technetium was in the +4 state in HCl, in the +5 state in citrate solution, and in both the +3 and +4 states in DTPA. (author)

Determination of Monochloroacetic Acid in Swimming Pool Water by Ion Chromatography-Conductivity Detection

Directory of Open Access Journals (Sweden)

Maria Pythias B. Espino

2013-12-01

Full Text Available In this study, an analytical method involving ion chromatography with conductivity detection was developed and optimized for the determination of monochloroacetic acid in swimming pool water. The ion chromatographic method has a detection limit of 0.02 mg L-1 and linear range of 0.05 to 1.0 mg L-1 with correlation coeff icient of 0.9992. The method is reproducible with percent RSD of 0.052% (n=10. The recovery of monochloroacetic acid spiked in different water types (bottled, tap and swimming pool water ranged from 28 to 122%. In dilute solutions, chloride and bromide were simultaneously analyzed along with monochloroacetic acid using the optimized method. Chloride and bromide have detection limits of 0.01 to 0.05 mg L-1, respectively. The usefulness of the ion chromatographic method was demonstrated in the analysis of monochloroacetic acid in swimming pool water samples. In such highly-chlorinated samples, an Ag/H cartridge was used prior to the ion chromatographic determination so as to minimize the signal due to chloride ion. Monochloroacetic acid was detected in concentrations between 0.020 and 0.093 mg L-1 in three of the six swimming pool water samples studied. The presence of monochloroacetic acid in the swimming pool water samples suggests the possible occurrence of other disinfection by-products in these waters.

Determination of Monochloroacetic Acid in Swimming Pool Water by Ion Chromatography-Conductivity Detection

Directory of Open Access Journals (Sweden)

Maria Pythias B. Espino

2013-02-01

Full Text Available In this study, an analytical method involving ion chromatography with conductivity detection was developed and optimized for the determination of monochloroacetic acid in swimming pool water. The ion chromatographic method has a detection limit of 0.02 mg L-1 and linear range of 0.05 to 1.0 mg L-1 with correlation coeff icient of 0.9992. The method is reproducible with percent RSD of 0.052% (n=10. The recovery of monochloroacetic acid spiked in different water types (bottled, tap and swimming pool water ranged from 28 to 122%. In dilute solutions, chloride and bromide were simultaneously analyzed along with monochloroacetic acid using the optimized method. Chloride and bromide have detection limits of 0.01 to 0.05 mg L-1, respectively. The usefulness of the ion chromatographic method was demonstrated in the analysis of monochloroacetic acid in swimming pool water samples. In such highly-chlorinated samples, an Ag/H cartridge was used prior to the ion chromatographic determination so as to minimize the signal due to chloride ion. Monochloroacetic acid was detected in concentrations between 0.020 and 0.093 mg L-1 in three of the six swimming pool water samples studied. The presence of monochloroacetic acid in the swimming pool water samples suggests the possible occurrence of other disinfection by-products in these waters.

Selective extraction of palladium with caffeine from acidic chloride media; Sansei enkabutsu yoeki karano kafuein ni yoru parajiumu no sentakuteki chushutsu

Energy Technology Data Exchange (ETDEWEB)

Kaikake, K.; Baba, Y. [Miyazaki University, Miyazaki (Japan). Faculty of Engineering

1999-06-10

In order to examine the possibility of caffeine as an extractant, the extraction of metal ions from acidic chloride media was studied at 298 K using the mixture solvent of chloroform and 2-ethyl-1-hexanol. Caffeine has exhibited a high selectivity for palladium (2) over base metals such as copper (2), nickel (2), and iron (3), and over precious metal such as platinum (4). The stoichiometric relation in the extraction of palladium (2) with caffeine was elucidated by examining the effects of chloride ion, hydrogen ion, and caffeine concentrations on its extractability. In addition, palladium (2) was found to be extracted selectively with caffeine from the mixture containing a 25-fold amount of platinum (4) or copper (2). The stripping of palladium (2) was performed to an extent of 80% by a single batchwise treatment with an aqueous mixture solution of hydrochloric acid and thiourea. (author)

Amine and Titanium (IV Chloride, Boron (III Chloride or Zirconium (IV Chloride-Promoted Baylis-Hillman Reactions

Directory of Open Access Journals (Sweden)

Shi-Cong Cui

2001-10-01

Full Text Available The Baylis-Hillman reactions of various aryl aldehydes with methyl vinyl ketone at temperatures below -20oC using Lewis acids such as titanium (IV chloride, boron (III chloride or zirconium (IV chloride in the presence of a catalytic amount of selected amines used as a Lewis bases afford the chlorinated compounds 1 as the major product in very high yields. Acrylonitrile can also undergo the same reaction to give the corresponding chlorinated product in moderate yield. A plausible reaction mechanism is proposed. However, if the reaction was carried out at room temperature (ca. 20oC, then the Z-configuration of the elimination product 3, derived from 1, was formed as the major product.

Accelerated solvent extraction followed by on-line solid-phase extraction coupled to ion trap LC/MS/MS for analysis of benzalkonium chlorides in sediment samples

Science.gov (United States)

Ferrer, I.; Furlong, E.T.

2002-01-01

Benzalkonium chlorides (BACs) were successfully extracted from sediment samples using a new methodology based on accelerated solvent extraction (ASE) followed by an on-line cleanup step. The BACs were detected by liquid chromatography/ion trap mass spectrometry (LC/MS) or tandem mass spectrometry (MS/MS) using an electrospray interface operated in the positive ion mode. This methodology combines the high efficiency of extraction provided by a pressurized fluid and the high sensitivity offered by the ion trap MS/MS. The effects of solvent type and ASE operational variables, such as temperature and pressure, were evaluated. After optimization, a mixture of acetonitrile/water (6:4 or 7:3) was found to be most efficient for extracting BACs from the sediment samples. Extraction recoveries ranged from 95 to 105% for C12 and C14 homologues, respectively. Total method recoveries from fortified sediment samples, using a cleanup step followed by ASE, were 85% for C12BAC and 79% for C14-BAC. The methodology developed in this work provides detection limits in the subnanogram per gram range. Concentrations of BAC homologues ranged from 22 to 206 ??g/kg in sediment samples from different river sites downstream from wastewater treatment plants. The high affinity of BACs for soil suggests that BACs preferentially concentrate in sediment rather than in water.

Chloride Transport in Heterogeneous Formation

Science.gov (United States)

Mukherjee, A.; Holt, R. M.

2017-12-01

The chloride mass balance (CMB) is a commonly-used method for estimating groundwater recharge. Observations of the vertical distribution of pore-water chloride are related to the groundwater infiltration rates (i.e. recharge rates). In CMB method, the chloride distribution is attributed mainly to the assumption of one dimensional piston flow. In many places, however, the vertical distribution of chloride will be influenced by heterogeneity, leading to horizontal movement of infiltrating waters. The impact of heterogeneity will be particularly important when recharge is locally focused. When recharge is focused in an area, horizontal movement of chloride-bearing waters, coupled with upward movement driven by evapotranspiration, may lead to chloride bulges that could be misinterpreted if the CMB method is used to estimate recharge. We numerically simulate chloride transport and evaluate the validity of the CMB method in highly heterogeneous systems. This simulation is conducted for the unsaturated zone of Ogallala, Antlers, and Gatuna (OAG) formations in Andrews County, Texas. A two dimensional finite element model will show the movement of chloride through heterogeneous systems. We expect to see chloride bulges not only close to the surface but also at depths characterized by horizontal or upward movement. A comparative study of focused recharge estimates in this study with available recharge data will be presented.

Application of ion implantation RBS to the study of electrocatalysis

International Nuclear Information System (INIS)

Kelly, E.J.; Vallet, C.E.; White, C.W.

1990-01-01

Ir-implanted titanium near-surface alloys were prepared by ion implantation, characterized (Ir concentration/depth profiles) by Rutherford backscattering (RBS), and subsequently anodically oxidized to form electrocatalytically active Ir x Ti 1-x O 2 /Ti electrodes. The electrochemical behavior of the metallic-like Ir 4 Ti 1-x O 2 /Ti electrodes in acidic chloride, sulfate, and perchlorate solutions was investigated, and the results compared with those previously obtained with similarly prepared Ru x Ti 1-x O 2 /Ti electrodes. For both electrodes, M x Ti 1-x O 2 /Ti (M equals Ir or Ru), the Tafel slope for the Cl 2 evolution reaction is 40 mV, i.e.,δE/δlog i equals 2.303 (2RT/3F). The reaction order (n) with respect to chloride ion concentration δlogi/δlog[Cl - ] + 1, where K 9 equals 54.9 dm 3 mol -1 for Ir x Ti 1-x O 2 /Ti and K 9 equals 40 dm 3 mol -1 for Ru x Ti 1-x O 2 /Ti. A modified Volmer-Heyrovsky mechanism, one in which the role of absorbed chloride ions is taken into account, is shown to be consistent with aforementioned diagnostic parameters

Voltammetry of uranyl chloride in the LiCl - KCl eutectic

International Nuclear Information System (INIS)

Fondanaiche, J.C.

1965-01-01

Spent UO 2 - PuO 2 fuels can be reprocessed in a molten salt media. Uranium dioxide can easily be dissolved as UO 2 Cl 2 in a molten salt bath using chlorine gas. A study of quantitative analysis of an uranyl chloride solution in the LiCl-KCl eutectic at 400 C has been performed here using voltammetry (a large area-graphite indicator electrode has been employed). The precision which is obtained is around 6 per cent for concentrations below 10 -2 M. Precision decreases slightly for more concentrated solutions. The study of polarization curves allowed to give a reduction mechanism for the UO 2 ++ ion. For dilute solutions, this reduction proceeds through the UO 2 + ion. But interpretation of current-potential curves is made difficult by the dismutation reaction of the UO 2 ion and by the fact that the surface of the indicator electrode is not renewed. (author) [fr

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

Science.gov (United States)

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

2017-12-01

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

Direct Detection of the Ion Pair to Free Ions Transformation upon Complexation with an Ion Receptor in Non‐Polar Solvents by using Conductometry

Science.gov (United States)

Iseda, Kazuya

2018-01-01

Abstract In this study, we performed conductometry in various organic solvents to directly detect the transformation from tetrabutylammonium chloride (TBACl) ion‐pair salt to the free ions through complexation with meso‐octamethylcalix[4]pyrrole (CP), which is a well‐known receptor for chloride anions. In the presence of CP, the conductivity of TBACl increases in various non‐polar solvents, indicating that complexation with CP enhances the ionic dissociation of TBACl in such non‐polar solvents. In other words, CP recognizes chloride as an ion‐paired salt as well as a free anion in non‐polar solvents. Additionally, the TBA(CP–Cl) complex exhibited a considerably lower ion‐pairing constant (K ip) than TBACl in non‐polar solvents, resulting in enhanced conductivity. Based on these findings, we can conclude that complexation of an anion with a hydrophobic anion receptor will be useful for creating functional and stimuli‐responsive soft materials in organic solvents using coulombic forces. PMID:29610717

Beryllium electrodeposition on aluminium cathode from chloride melts

International Nuclear Information System (INIS)

Nichkov, I.F.; Novikov, E.A.; Serebryakov, G.A.; Kanashin, Yu.P.; Sardyko, G.N.

1980-01-01

Cathodic processes during beryllium deposition on liquid and solid aluminium cathodes are investigated. Mixture of sodium, potassium and beryllium chloride melts served as an lectrolyte. Beryllium ion discharge at the expense of alloy formation takes place at more positive potentials than on an indifferent cathode at low current densities ( in the case of liquid aluminium cathode). Metallographic analysis and measurements of microhardness have shown, that the cathodic product includes two phases: beryllium solid solution in aluminium and metallic beryllium. It is concluded, that aluminium-beryllium alloys with high cathodic yield by current can be obtained by the electrolytic method

Electrochemical Chloride extraction using external electrodes?

DEFF Research Database (Denmark)

Ottosen, Lisbeth M.; Pedersen, Anne Juul

2006-01-01

Electrochemical methods for the removal of chloride from concrete have been developed and the methods are primarily designed for situations where corrosion has started due to an increased chloride concentration in the vicinity of the reinforcement. In these methods the reinforcement is used...... as the cathode. However, some unwanted side effects can occur, including alkali-silica reaction and in some cases hydrogen embrittlement. It is also suggested also to use electrochemical chloride extraction in a preventive way in constructions where chloride induced corrosion is likely to be a problem after...... a period of time, i.e. remove the chlorides before the chloride front reaches the reinforcement. If the chlorides are removed from outer few centimetres from the surface, the chloride will not reach the reinforcement and cause damage. By using the electrochemical chloride removal in this preventive way...

Ion-pair hollow-fiber liquid-phase microextraction of the quaternary ammonium surfactant dicocodimethylammonium chloride.

Science.gov (United States)

Hultgren, Sofie; Larsson, Niklas; Nilsson, Bo F; Jönsson, Jan Ake

2009-02-01

A two-phase hollow-fiber (HF) liquid-phase microextraction (LPME) method was developed for determination of a quaternary ammonium compound surfactant, dicocodimethylammonium chloride, in aqueous samples. The porous HF was fixed on a metal rod support and was impregnated with approximately 6.6 microL of organic extractant, which was immobilized in the HF pores. Surfactant extraction was facilitated by addition of carboxylic acid to the sample forming neutral ion pairs with the quaternary ammonium compound. After extraction, the analyte was transferred from the organic extractant in the fiber pores by dissolving the 1-octanol into 100 microL methanol. The methanol extract was analyzed by liquid chromatography-mass spectrometry. The method was optimized (with optimized parameters in brackets) with regard to type of organic extractant (1-octanol), fiber length (2 cm), choice and concentration of anionic carrier (600 microg L(-1) octanoate), procedure of transfer to methanol (15-min sonication), sample volume (250 mL), extraction time (17 h), pH (10), and ionic strength (50 mM carbonate). Aspects influencing repeatability in LPME of (quaternary ammonium) surfactants are discussed. The enrichment factor achieved in 250-mL carbonate buffer was around 400. Due to matrix effects, the enrichment factors achieved when industrial process water was analyzed were 120 or about 30% of that in carbonate buffer. Detection limits of 0.3 microg L(-1) in carbonate buffer and 0.9 microg L(-1) in industrial process water were obtained. If the studied compound is seen as a model substance representing quaternary dialkylated dimethylated ammonium surfactants in general, the developed method may be applied to other quaternary ammonium surfactants.

The corrosive influence of chloride ions preference adsorption on α-Al{sub 2}O{sub 3} (0 0 0 1) surface

Energy Technology Data Exchange (ETDEWEB)

Zhang, Chuan-Hui, E-mail: zhangch@ustb.edu.cn; Liu, Min; Jin, Ying; Sun, Dong-Bai, E-mail: dbsun@mater.ustb.edu.cn

2015-08-30

Graphical abstract: - Highlights: • The preference adsorption and interaction of Cl{sup −} at increasing monolayer coverage on Al{sub 2}O{sub 3} in solution environment are modeling by DFT with COSMO. • A redefinition critical one plane monolayer of Cl{sup −} is 3/7, and the adsorption energy decrease in three steps, each adsorption energy step only relate to the adsorption site and the morphology. • The weaker interaction between Cl{sup −} and Al{sub 2}O{sub 3} surface but stronger interactions between three Cl{sup −} make the electrons uniformly occupy on the energy levels of three ions. - Abstract: Conductor-like screening model (COSMO), Periodic DFT calculations have been performed on a Al{sub 2}O{sub 3} surface to model the influence of preference adsorption and interaction of chloride ions at increasing monolayer coverage on undefective passive film on Aluminum in solution environment. The results evidence that the critical monolayer of Cl{sup −} is 3/7, which is redefined. With increasing Cl{sup −} adsorption, both the first and second Cl{sup −} move from Al(1) atop and bridge10 sites to O(5) sites, suggesting that the weaker interaction between Cl{sup −} and Al{sub 2}O{sub 3} surface but stronger interactions between three ions make the electrons uniformly occupy on the energy levels of them. More calculations shows that the preference adsorption sites of Cl{sup −} are independent of the surface area of oxide, and the adsorption energy decrease in three steps, each adsorption energy step only relate to the adsorption site and the morphology. On undefective oxide film, low coverage Cl{sup −} adsorption would restrain surface breakdown to happen which is consistent with the experiment results.

Molecular dynamics simulation, ab initio calculation, and size-selected anion photoelectron spectroscopy study of initial hydration processes of calcium chloride.

Science.gov (United States)

He, Zhili; Feng, Gang; Yang, Bin; Yang, Lijiang; Liu, Cheng-Wen; Xu, Hong-Guang; Xu, Xi-Ling; Zheng, Wei-Jun; Gao, Yi Qin

2018-06-14

To understand the initial hydration processes of CaCl 2 , we performed molecular simulations employing the force field based on the theory of electronic continuum correction with rescaling. Integrated tempering sampling molecular dynamics were combined with ab initio calculations to overcome the sampling challenge in cluster structure search and refinement. The calculated vertical detachment energies of CaCl 2 (H 2 O) n - (n = 0-8) were compared with the values obtained from photoelectron spectra, and consistency was found between the experiment and computation. Separation of the Cl-Ca ion pair is investigated in CaCl 2 (H 2 O) n - anions, where the first Ca-Cl ionic bond required 4 water molecules, and both Ca-Cl bonds are broken when the number of water molecules is larger than 7. For neutral CaCl 2 (H 2 O) n clusters, breaking of the first Ca-Cl bond starts at n = 5, and 8 water molecules are not enough to separate the two ion pairs. Comparing with the observations on magnesium chloride, it shows that separating one ion pair in CaCl 2 (H 2 O) n requires fewer water molecules than those for MgCl 2 (H 2 O) n . Coincidentally, the solubility of calcium chloride is higher than that of magnesium chloride in bulk solutions.

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

Directory of Open Access Journals (Sweden)

H. Guan

2010-05-01

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

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

KAUST Repository

Yoon, Seyoon

2014-06-01

This study investigated the feasibility of using calcined layered double hydroxides (CLDHs) to prevent chloride-induced deterioration in reinforced concrete. CLDHs not only adsorbed chloride ions in aqueous solution with a memory effect but also had a much higher binding capacity than the original layered double hydroxides (LDHs) in the cement matrix. We investigated this adsorption in hardened cement paste in batch cultures to determine adsorption isotherms. The measured and theoretical binding capacities (153 mg g -1 and 257 mg g-1, respectively) of the CLDHs were comparable to the theoretical capacity of Friedel\\'s salt (2 mol mol-1 or 121 mg g-1), which belongs to the LDH family among cementitious phases. We simulated chloride adsorption by CLDHs through the cement matrix using the Fickian model and compared the simulation result to the X-ray fluorescence (XRF) chlorine map. Based on our results, it is proposed that the adsorption process is governed by the chloride transport through the cement matrix; this process differs from that in an aqueous solution. X-ray diffraction (XRD) analysis showed that the CLDH rebuilds the layered structure in a cementitious environment, thereby demonstrating the feasibility of applying CLDHs to the cement and concrete industries. © 2014 Published by Elsevier B.V. All rights reserved.

GmCLC1 Confers Enhanced Salt Tolerance through Regulating Chloride Accumulation in Soybean

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Peipei Wei

2016-07-01

Full Text Available The family of chloride channel proteins that mediate Cl- transportation play vital roles in plant nutrient supply, cellular action potential and turgor pressure adjustment, stomatal movement, hormone signal recognition and transduction, Cl- homeostasis, and abiotic and biotic stress tolerance. The anionic toxicity, mainly caused by chloride ions (Cl-, on plants under salt stress remains poorly understood. In this work, we investigated the function of soybean Cl-/H+ antiporter GmCLC1 under salt stress in transgenic Arabidopsis thaliana, soybean, and yeast. We found that GmCLC1 enhanced salt tolerance in transgenic A. thaliana by reducing the Cl- accumulation in shoots and hence released the negative impact of salt stress on plant growth. Overexpression of GmCLC1 in the hairy roots of soybean sequestered more Cl- in their roots and transferred less Cl- to their shoots, leading to lower relative electrolyte leakage values in the roots and leaves. When either the soybean GmCLC1 or the yeast chloride transporter gene, GEF1, was transformed into the yeast gef1 mutant, and then treated with different chloride salts (MnCl2, KCl, NaCl, enhanced survival rate was observed. The result indicates that GmCLC1 and GEF1 exerted similar effects on alleviating the stress of diverse chloride salts on the yeast gef1 mutant. Together, this work suggests a protective function of GmCLC1 under Cl- stress.

21 CFR 184.1297 - Ferric chloride.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ferric chloride. 184.1297 Section 184.1297 Food and... Substances Affirmed as GRAS § 184.1297 Ferric chloride. (a) Ferric chloride (iron (III) chloride, FeC13, CAS Reg. No. 7705-08-0) may be prepared from iron and chlorine or from ferric oxide and hydrogen chloride...

Influence of chloride ions on the stability of PtNi alloys for PEMFC cathode

NARCIS (Netherlands)

Jayasayee, K.; Veen, van J.A.R.; Hensen, E.J.M.; Bruijn, de F.A.

2011-01-01

The dependence of the rate of Ni dissolution from PtNi alloys on the chloride concentration was studied electrochemically in 0.5 M HClO4 at room temperature. Electrodeposited PtNi catalysts were subjected to extensive potential cycling between 20 mV and 1.3 V at various Cl- concentrations and the

The electrochemical behaviour study of La{sup 3+} ion in fused chlorides bath. The LaNi{sub 5} formation; Estudo do comportamento eletroquimico do ion La{sup 3+} em meio a cloretos fundidos. A formacao de LaNi{sub 5}

Energy Technology Data Exchange (ETDEWEB)

Dias, Cristiane

2002-07-01

The electrochemical behaviour of La{sup 3+} ion was studied in fused chlorides bath, with purpose to obtain LaNi{sub 5} formation parameters. The lanthanum reduction/reoxidation mechanism and intermetallic compound formation were investigated by cyclic voltammetry, chronopotentiommetry and galvanostatic electrodeposition. The electrolyte employed was eutectic mixture NaCl-KCl (1:1) with anhydrous LaCl{sub 3} as solute, since 0,25 mol. L{sup -1} up to 2 mol. L{sup -1}, between 700 deg C and 800 deg C. The anhydrous LaCl{sub 3} was prepared by lanthanum chloride slow dehydration with HCl flow and heating until 300 deg C. Over molybdenum, results depicted that lanthanum electrochemical behaviour was quasi-reversible and electrodeposition occurred in a charge transfer step with three electrons. In nickel, intermetallic compound formation was observed by interdiffusion. The scanning electronic microscopy (SEM-EDS) and X ray diffraction analysis indicated that layers composition depend on temperature and solute concentration in fused bath. Mainly LaNi{sub 5} intermetallic compound was formed with LaCl{sub 3} anhydrous concentration of 2 mol. L{sup -1} at 750 deg C, with cathodic current density until 100 mA.cm{sup -2}. (author)

Double isotopic method using dansyl chloride for the determination of GABA in rat C6 astrocytoma cell cultures

Energy Technology Data Exchange (ETDEWEB)

Kohl, R.L.; Quay, W.B.; Perez-Polo, J.R.

1986-01-01

Methods are described for the quantitative measurement of GABA in culture. The method can be adapted to any amino acid or dansyl-chloride-reactive species. The sensitivity and selectivity of the procedure result from the double isotopic design in which (/sup 14/C)-labeled internal standard was added to the samples before reaction with (3M)-labeled dansyl chloride. Values obtained by ion-exchange amino acid analysis of cultures agree closely with the values obtained by the double isotopic method. This method is sensitive enough to measure GABA intracellularly and the condition medium.

Molecular, biophysical, and pharmacological properties of calcium-activated chloride channels.

Science.gov (United States)

Kamaleddin, Mohammad Amin

2018-02-01

Calcium-activated chloride channels (CaCCs) are a family of anionic transmembrane ion channels. They are mainly responsible for the movement of Cl - and other anions across the biological membranes, and they are widely expressed in different tissues. Since the Cl - flow into or out of the cell plays a crucial role in hyperpolarizing or depolarizing the cells, respectively, the impact of intracellular Ca 2+ concentration on these channels is attracting a lot of attentions. After summarizing the molecular, biophysical, and pharmacological properties of CaCCs, the role of CaCCs in normal cellular functions will be discussed, and I will emphasize how dysregulation of CaCCs in pathological conditions can account for different diseases. A better understanding of CaCCs and a pivotal regulatory role of Ca 2+ can shed more light on the therapeutic strategies for different neurological disorders that arise from chloride dysregulation, such as asthma, cystic fibrosis, and neuropathic pain. © 2017 Wiley Periodicals, Inc.

Isotopic exchange reaction between barium ion and tri barium phosphate

International Nuclear Information System (INIS)

Bilgin, G.B.; Cetin, I.

1982-01-01

Heterogeneous exchange reaction of tri barium phosphate in barium chloride solution has been studied using 133 Ba as a tracer. The results show that the exchange fraction increases as barium chloride concentration increases for different mole ratio of the exchange ion on the solid surface and in the solution. The phenomenon was studied with respect to the previous treatment of the precipitate leading to different crystal sizes and the effect of reaction time. (author)

Influence of Palm Oil Fuel Ash and W/B Ratios on Compressive Strength, Water Permeability, and Chloride Resistance of Concrete

Directory of Open Access Journals (Sweden)

Wachilakorn Sanawung

2017-01-01

Full Text Available This research studies the effects of W/B ratios and palm oil fuel ash (POFA on compressive strength, water permeability, and chloride resistance of concrete. POFA was ground until the particles retained on sieve number 325 were less than 5% by weight. POFA was used to partially replace OPC at rates of 15, 25, and 35% by weight of binder. The water to binder (W/B ratios of concrete were 0.40 and 0.50. The compressive strength, water permeability, and chloride resistance of concrete were investigated up to 90 days. The results showed that POFA concrete with W/B ratio of 0.40 had the compressive strengths ranging from 45.8 to 55.9 MPa or 82–94% of OPC concrete at 90 days, while POFA concrete with W/B ratio of 0.50 had the compressive strengths of 33.9–41.9 MPa or 81–94% of OPC concrete. Furthermore, the compressive strength of concrete incorporation of ground POFA at 15% was the same as OPC concrete. The water permeability coefficient and the chloride ion penetration of POFA concrete were lower than OPC concrete when both types of concrete had the same compressive strengths. The findings also indicated that water permeability and chloride ion penetration of POFA concrete were significantly reduced compared to OPC concrete.

Simulation-based Analysis of the Differences in the Removal Rate of Chlorides, Nitrates and Sulfates by Electrokinetic Desalination Treatments

DEFF Research Database (Denmark)

Paz-Garcia, Juan Manuel; Johannesson, Björn; Ottosen, Lisbeth M.

2012-01-01

than chlorides and nitrates. A physicochemical model for electrochemically-induced reactive-transport processes is described and used for a theoretical analysis of the influence of the chemical interactions on the removal rate of the target ions. Simulations for the electro-desalination of a brick......Due to their abundance in the natural environment, chloride, nitrate and sulfate salts are considered the main responsible for the salt-induced decay processes in building materials and sculptures. Electro-desalination techniques, enhanced with carbonated clay buffer poultice placed between...

Reaction of calcium chloride with alkali metal chlorides in melts

International Nuclear Information System (INIS)

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

1984-01-01

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

Distinct freshwater and seawater isoforms of Na+/K+-ATPase in gill chloride cells of Atlantic salmon

Science.gov (United States)

McCormick, Stephen D.; Regish, A.M.; Christensen, A.K.

2009-01-01

Gill Na(+)/K(+)-ATPase (NKA) in teleost fishes is involved in ion regulation in both freshwater and seawater. We have developed and validated rabbit polyclonal antibodies specific to the NKA alpha1a and alpha1b protein isoforms of Atlantic salmon (Salmo salar Linnaeus), and used western blots and immunohistochemistry to characterize their size, abundance and localization. The relative molecular mass of NKA alpha1a is slightly less than that for NKA beta1b. The abundance of gill NKA alpha1a was high in freshwater and became nearly undetectable after seawater acclimation. NKA alpha1b was present in small amounts in freshwater and increased 13-fold after seawater acclimation. Both NKA isoforms were detected only in chloride cells. NKA alpha1a was located in both filamental and lamellar chloride cells in freshwater, whereas in seawater it was present only as a faint background in filamental chloride cells. In freshwater, NKA alpha1b was found in a small number of filamental chloride cells, and after seawater acclimation it was found in all chloride cells on the filament and lamellae. Double simultaneous immunofluorescence indicated that NKA alpha1a and alpha1b are located in different chloride cells in freshwater. In many chloride cells in seawater, NKA alpha1b was present in greater amounts in the subapical region than elsewhere in the cell. The combined patterns in abundance and immunolocalization of these two isoforms can explain the salinity-related changes in total NKA and chloride cell abundance. The results indicate that there is a freshwater and a seawater isoform of NKA alpha-subunit in the gills of Atlantic salmon and that they are present in distinct chloride cells.

Using chloride and other ions to trace sewage and road salt in the Illinois Waterway

Science.gov (United States)

Kelly, W.R.; Panno, S.V.; Hackley, Keith C.; Hwang, H.-H.; Martinsek, A.T.; Markus, M.

2010-01-01

Chloride concentrations in waterways of northern USA are increasing at alarming rates and road salt is commonly assumed to be the cause. However, there are additional sources of Cl- in metropolitan areas, such as treated wastewater (TWW) and water conditioning salts, which may be contributing to Cl- loads entering surface waters. In this study, the potential sources of Cl- and Cl- loads in the Illinois River Basin from the Chicago area to the Illinois River's confluence with the Mississippi River were investigated using halide data in stream samples and published Cl- and river discharge data. The investigation showed that road salt runoff and TWW from the Chicago region dominate Cl- loads in the Illinois Waterway, defined as the navigable sections of the Illinois River and two major tributaries in the Chicago region. Treated wastewater discharges at a relatively constant rate throughout the year and is the primary source of Cl- and other elements such as F- and B. Chloride loads are highest in the winter and early spring as a result of road salt runoff which can increase Cl- concentrations by up to several hundred mg/L. Chloride concentrations decrease downstream in the Illinois Waterway due to dilution, but are always elevated relative to tributaries downriver from Chicago. The TWW component is especially noticeable downstream under low discharge conditions during summer and early autumn when surface drainage is at a minimum and agricultural drain tiles are not flowing. Increases in population, urban and residential areas, and roadways in the Chicago area have caused an increase in the flux of Cl- from both road salt and TWW. Chloride concentrations have been increasing in the Illinois Waterway since around 1960 at a rate of about 1 mg/L/a. The increase is largest in the winter months due to road salt runoff. Shallow groundwater Cl- concentrations are also increasing, potentially producing higher base flow concentrations. Projected increases in population and

Use of marker ion and cationic surfactant plastic membrane electrode for potentiometric titration of cationic polyelectrolytes.

Science.gov (United States)

Masadome, Takashi; Imato, Toshihiko

2003-07-04

A plasticized poly (vinyl chloride) (PVC) membrane electrode sensitive to stearyltrimethylammonium (STA) ion is applied to the determination of cationic polyelectrolytes such as poly (diallyldimethylammonium chloride) (Cat-floc) by potentiometric titration, using a potassium poly (vinyl sulfate) (PVSK) solution as a titrant. The end-point of the titration is detected as the potential change of the plasticized PVC membrane electrode caused by decrease in the concentration of STA ion added to the sample solution as a marker ion due to the ion association reaction between the STA ion and PVSK. The effects of the concentration of STA ion, coexisting electrolytes in the sample solution and pH of the sample on the degree of the potential change at the end-point were examined. A linear relationship between the concentration of cationic polyelectrolyte and the end-point volume of the titrant exists in the concentration range from 2x10(-5) to 4x10(-4) N for Cat-floc, glycol chitosan, and methylglycol chitosan.

Methods for evaluating potential sources of chloride in surface waters and groundwaters of the conterminous United States

Science.gov (United States)

Granato, Gregory E.; DeSimone, Leslie A.; Barbaro, Jeffrey R.; Jeznach, Lillian C.

2015-09-04

Chloride exists as a major ion in most natural waters, but many anthropogenic sources are increasing concentrations of chloride in many receiving waters. Although natural concentrations in continental waters can be as high as 200,000 milligrams per liter, chloride concentrations that are suitable for freshwater ecology, human consumption, and agricultural and industrial water uses commonly are on the order of 10 to 1,000 milligrams per liter. “Road salt” frequently is identified as the sole source of anthropogenic chloride, but only about 30 percent of the salt consumed and released to the environment is used for deicing. Furthermore, several studies in Southern States where the use of deicing salt is minimal also show anthropogenic chloride in rising concentrations and in strong correlation to imperviousness and road density. This is because imperviousness and road density also are strongly correlated to population density. The term “road salt” is a misnomer because deicers applied to parking lots, sidewalks, and driveways can be a substantial source of chloride in some catchments because these land covers are comparable to roadways as a percentage of the total impervious area and commonly receive higher salt application rates than some roadways. Other sources of anthropogenic chloride include wastewater, dust control on unpaved roads, fertilizer, animal waste, irrigation, aquaculture, energy production wastes, and landfill leachates. The assumption that rising chloride concentrations in surface water or groundwater is indicative of contamination by deicing chemicals rather than one or more other potential sources may preclude the identification of toxic, carcinogenic, mutagenic, or endocrine-disrupting contaminants that are associated with many sources of elevated chloride concentrations. Once the sources of anthropogenic chloride in an area of interest have been identified and measured, water and solute budgets can be estimated to guide decisionmakers to

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

International Nuclear Information System (INIS)

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

1975-01-01

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

The need of alkalinity determination in the characterization of rain; Necesidad de la determinacion de la alcalinidad en la caracterizacion de la lluvia

Energy Technology Data Exchange (ETDEWEB)

Pal Verma, Mahendra [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1998-01-01

In this paper is presented the alkalinity determination of the carbonic species in the rain waters by the Gran titration method. The alkalinity values obtained by this method in low electric conductivity waters are fairly reliable. Also, the existing studies on the characterization of acid rains, are discussed. [Espanol] En este trabajo se presenta la medicion de la alcalinidad y la determinacion de las especies carbonicas en las aguas de lluvia por el metodo de la titulacion de Gran. Los valores de alcalinidad obtenidos por este metodo en las aguas de baja conductividad electrica son bastante confiables. Asimismo, se discuten los estudios existentes sobre la caracterizacion de la lluvia acida en la republica mexicana.

Lack of the sodium-driven chloride bicarbonate exchanger NCBE impairs visual function in the mouse retina.

Directory of Open Access Journals (Sweden)

Gerrit Hilgen

Full Text Available Regulation of ion and pH homeostasis is essential for normal neuronal function. The sodium-driven chloride bicarbonate exchanger NCBE (Slc4a10, a member of the SLC4 family of bicarbonate transporters, uses the transmembrane gradient of sodium to drive cellular net uptake of bicarbonate and to extrude chloride, thereby modulating both intracellular pH (pH(i and chloride concentration ([Cl(-](i in neurons. Here we show that NCBE is strongly expressed in the retina. As GABA(A receptors conduct both chloride and bicarbonate, we hypothesized that NCBE may be relevant for GABAergic transmission in the retina. Importantly, we found a differential expression of NCBE in bipolar cells: whereas NCBE was expressed on ON and OFF bipolar cell axon terminals, it only localized to dendrites of OFF bipolar cells. On these compartments, NCBE colocalized with the main neuronal chloride extruder KCC2, which renders GABA hyperpolarizing. NCBE was also expressed in starburst amacrine cells, but was absent from neurons known to depolarize in response to GABA, like horizontal cells. Mice lacking NCBE showed decreased visual acuity and contrast sensitivity in behavioral experiments and smaller b-wave amplitudes and longer latencies in electroretinograms. Ganglion cells from NCBE-deficient mice also showed altered temporal response properties. In summary, our data suggest that NCBE may serve to maintain intracellular chloride and bicarbonate concentration in retinal neurons. Consequently, lack of NCBE in the retina may result in changes in pH(i regulation and chloride-dependent inhibition, leading to altered signal transmission and impaired visual function.

Effects of O2 and H2O plasma immersion ion implantation on surface chemical composition and surface energy of poly vinyl chloride

International Nuclear Information System (INIS)

Zhang Wei; Chu, Paul K.; Ji Junhui; Zhang, Yihe; Jiang Zhimin

2006-01-01

Oxygen and water plasma immersion ion implantation (PIII) was used to modify poly vinyl chloride (PVC) to enhance oxygen-containing surface functional groups for more effective grafting. The modified surfaces were characterized by X-ray photoelectron spectroscopy (XPS), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), and contact angle measurements. Our experimental results show that both oxygen and water PIII can greatly improve the O to C ratios on the surface. The optimal plasma processing conditions differ for the two treatments. The hydrophilicity and surface energy of the plasma-implanted PVC are also improved significantly. Our results indicate that O 2 and H 2 O PIII increase both the polar and dispersion interactions and consequently the surface energy. It can be explained by the large amount of oxygen introduced to the surface and that many C-C bonds are transformed into more polar oxygen containing functional groups

Preparation of the Hexacyanoferrate Ion Exchanger Matrix to Concentrate 137Cs from Sea Water

International Nuclear Information System (INIS)

Murdahayu Makmur

2007-01-01

Preparation of the hexacyanoferrate ion exchanger matrix to concentrate 137 Cs from large volume sea water has been done. The Pre-concentration is needed because 137 Cs concentration in sea water is too low. The hexacyanoferrate ion exchanger matrix can be prepared by performing the reaction of 10 gram silica gel with potassium hexacyanoferrate on concentration variation of 0.0025 M - 0.04 M and copper chloride on concentration variation of 0.005 M - 0.08 M. The volume of each reagent was 25 ml. The performance of the ion exchanger matrix depends on the chemical compositions both of the mixtures, it was expected that no remaining Fe ion and free Cu from the initial reagent. The final effluent will analyzed for Fe and Cu using Atomic Absorption Spectrometer. The optimal molar composition ration for potassium hexacyanoferrate and copper chloride was 0.5 for 10 gram silica gel. (author)

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

International Nuclear Information System (INIS)

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

2008-01-01

Effects of pH solution and chloride (Cl - ) ion concentration on the corrosion behaviour of alloy AA6061 immersed in aqueous solutions of NaCl have been investigated using measurements of weight loss, potentiodynamic polarisation, linear polarisation, cyclic polarisation experiment combined with open circuit potential transient technique and optical or scanning electron microscopy. The corrosion behaviour of the AA6061 aluminum alloy was found to be dependant on the pH and chloride concentration [NaCl] of solution. In acidic or slightly neutral solutions, general and pitting corrosion occurred simultaneously. In contrast, exposure to alkaline solutions results in general corrosion. Experience revealed that the alloy AA6061 was susceptible to pitting corrosion in all chloride solution of concentration ranging between 0.003 wt% and 5.5 wt% NaCl and an increase in the chloride concentration slightly shifted both the pitting E pit and corrosion E cor potentials to more active values. In function of the conditions of treatment, the sheets of the alloy AA6061 undergo two types of localised corrosion process, leading to the formation of hemispherical and crystallographic pits. Polarisation resistance measurements in acidic (pH = 2) and alkaline chloride solutions (pH = 12) which are in good agreement with those of weight loss, show that the corrosion kinetic is minimised in slightly neutral solutions (pH = 6)

Thermogravimetric method of estimation of uranyl cation state in melts of alkali metal chlorides and their mixtures

International Nuclear Information System (INIS)

Vorobej, M.P.; Desyatnik, V.N.

1979-01-01

The thermogravimetric method was used to study the chloridizing of uranium oxides in molten media. The study of the uranium oxide chloridizing served as a basis for evaluating comparatively, using the DTA method, the uranyl-cation state in a melt. Using the alkali metals as example, it was shown that the decomposition of the frozen uranium oxychlorides proceeds with the formation of intermediate chlorouranates. The final product of the thermolysis are uranates Me 2 U 2 O 7 (Me-Li, Na, K, Rb, Cs). The time and the conditions of the change of uranium oxides to the oxyanion [UO 2 Cl 4 ] 2- were determined as a function of the chloridizing agent. The method can be employed for evaluating uranyl-ions in molten media where they are used as electrolytes in the extraction of uranium dioxide

Electrochemical chloride extraction of a beam polluted by chlorides after 40 years in the sea

OpenAIRE

BOUTEILLER, Véronique; LAPLAUD, André; MALOULA, Aurélie; MORELLE, René Stéphane; DUCHESNE, Béatrice; MORIN, Mathieu

2006-01-01

A beam element, naturally polluted by chlorides after 40 years of a marine tidal exposure, has been treated by electrochemical chloride extraction. The chloride profiles, before and after treatment, show that free chlorides are extrated with an efficiency of 70 % close to the steel, 50 % in the intermediate cover and only 5 % at the concrete surface. From the electrochemical characterizations (before, after, 1, 2 and 17 months after treatment), the steel potential values can, semehow, indicat...

The effect of Cu-rich sub-layer on the increased corrosion resistance of Cu-xZn alloys in chloride containing borate buffer

International Nuclear Information System (INIS)

Milosev, Ingrid; Mikic, Tadeja Kosec; Gaberscek, Miran

2006-01-01

The electrochemical behaviour of Cu-xZn alloys, as well as their constituent metals, in a borate buffer containing chloride ions in the molar range from 0.01 to 1 M are studied. Characteristics of these materials under anodic polarization are compared and the composition and morphology of the corrosion products formed in the course of polarization experiment are analysed by SEM and EDS. X-ray photoelectron spectroscopy and electrochemical impedance measurements are used for characterization of the surface layers formed on Cu, Zn and Cu-40Zn alloy during 2-h immersion at E oc in a borate buffer containing two different concentrations of chloride ions. New aspects of the behaviour of brass under E oc condition are revealed. The improved corrosion resistance of brass in chloride media, if compared to zinc metal, is attributed to a Cu-rich layer formed by the selective dissolution of zinc. Based on the results, a structural model describing the improved corrosion resistance of Cu-40Zn alloy with respect to Zn metal is proposed

Sorption of Hg(II and Pb(II Ions on Chitosan-Iron(III from Aqueous Solutions: Single and Binary Systems

Directory of Open Access Journals (Sweden)

Byron Lapo

2018-03-01

Full Text Available The present work describes the study of mercury Hg(II and lead Pb(II removal in single and binary component systems into easily prepared chitosan-iron(III bio-composite beads. Scanning electron microscopy and energy-dispersive X-ray (SEM-EDX analysis, Fourier transform infrared spectroscopy (FTIR, thermogravimetric analysis (TGA and point of zero charge (pHpzc analysis were carried out. The experimental set covered pH study, single and competitive equilibrium, kinetics, chloride and sulfate effects as well as sorption–desorption cycles. In single systems, the Langmuir nonlinear model fitted the experimental data better than the Freundlich and Sips equations. The sorbent material has more affinity to Hg(II rather than Pb(II ions, the maximum sorption capacities were 1.8 mmol·g−1 and 0.56 mmol·g−1 for Hg(II and Pb(II, respectively. The binary systems data were adjusted with competitive Langmuir isotherm model. The presence of sulfate ions in the multicomponent system [Hg(II-Pb(II] had a lesser impact on the sorption efficiency than did chloride ions, however, the presence of chloride ions improves the selectivity towards Hg(II ions. The bio-based material showed good recovery performance of metal ions along three sorption–desorption cycles.

21 CFR 173.375 - Cetylpyridinium chloride.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Cetylpyridinium chloride. 173.375 Section 173.375... CONSUMPTION Specific Usage Additives § 173.375 Cetylpyridinium chloride. Cetylpyridinium chloride (CAS Reg. No....1666 of this chapter, at a concentration of 1.5 times that of cetylpyridinium chloride. (c) The...

21 CFR 184.1622 - Potassium chloride.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium chloride. 184.1622 Section 184.1622 Food... Specific Substances Affirmed as GRAS § 184.1622 Potassium chloride. (a) Potassium chloride (KCl, CAS Reg... levels not to exceed current good manufacturing practice. Potassium chloride may be used in infant...

Sodium and chloride levels in rainfall, mist, streamwater and groundwater at the Plynlimon catchments, mid-Wales: inferences on hydrological and chemical controls

Directory of Open Access Journals (Sweden)

C. Neal

2000-01-01

Full Text Available Variations in sodium and chloride in atmospheric inputs (rainfall and mist, stream runoff and groundwater stores are documented for the upper Severn River (Afon Hafren and Afon Hore catchments, Plynlimon, mid-Wales. The results show five salient features. Sodium and chloride concentrations are highly variable and highly correlated in rainfall and mist. The sodium-chloride relationship in rainfall has a slope close to the sodium/chloride ratio in sea-water, and an intercept that is not significantly different from zero. This indicates that sea-salt is the dominant source of both sodium and chloride in rainfall, which would be expected given the maritime nature of the metrology. For mist, there is also a straight line with near-zero intercept, but with a slightly higher gradient than the sea-salt ratio, presumably due to small additional sodium inputs from other sources. There is an approximate input-output balance for both sodium and chloride, with the exception of one groundwater well, in which high chemical weathering results in an anomalous high Na/Cl ratio. Thus, atmospheric deposition is the dominant source of both sodium and chloride in groundwater and streamflow. The fluctuations in sodium and chloride concentrations in the streams and groundwaters are strongly damped compared to those in the rain and the mist, reflecting the storage and mixing of waters in the subsurface. On all timescales, from weeks to years, sodium fluctuations are more strongly damped than chloride fluctuations in streamflow. The additional damping of sodium is consistent with ion exchange buffering of sodium in the catchment soils.  Sodium and chloride concentrations are linearly correlated in the streams and groundwaters, but the slope is almost universally less than the sea-salt ratio and there is a non-zero intercept. The Na/Cl ratio in streamflow and groundwater is higher than the sea-salt ratio when salinity is low and lower than the sea-salt ratio when

Potassium Chloride Versus Voltage Clamp Contractures in Ventricular Muscle

Science.gov (United States)

Morad, M.; Reeck, S.; Rao, M.

1981-01-01

In frog ventricle, developed tension was markedly larger in response to depolarization caused by a voltage clamp step than to depolarization induced by high concentrations of potassium chloride. Measurement of extracellular potassium activity at the surface and at the depth of muscle during the development of contractures showed that the diffusion of potassium is much slower than the spread of depolarization through the cross section of muscle. These two observations suggest that competition between the depolarizing and the negative inotropic effects of an increase in the extracellular potassium ion concentration may determine the time course and magnitude of contractile tension in heart muscle.

Corrosion potential: influence of moisture, water-cement ratio, chloride content and concrete cover

Directory of Open Access Journals (Sweden)

M. H. F. Medeiros

Full Text Available ABSTRACT The method of measuring the corrosion potential is used as an electrochemical tool for helping the monitoring of the corrosion of reinforcements of concrete structures. As a criterion for evaluating results it is common to use intervals of corrosion potential and their correlation with corrosion probability, as precognizes ASTM C 876:2015. With this criterion, it is possible to establish an overview of the thermodynamic situation of corrosion in the structure or in the test specimen in laboratory. However, the method is influenced by several factors related with the concrete, the environment and with procedures adopted at the moment of executing the readings. Aiming to provide information to guide the technical and scientific environment regarding the right use of this type of non-destructive testing, the objective of this work is to evaluate some possible factors influencing the reading of corrosion potential, such as: moisture content of the concrete, water/cement ratio, thickness of the concrete cover and degree of contamination by chlorides. Results indicate that moisture and degree of contamination of the concrete by chloride ions had a tendency of making the corrosion potential more electronegative. Besides, it was verified that the influence of the cover is different for the case of contaminated concrete (1% of chlorides by mass of cement and not contaminated with chlorides: the influence of the thickness of the cover, in the case of concrete contaminated by chlorides, was inversely proportional, in other words, the greater the cover thickness is, the less electronegative the value of the corrosion potential will be. On the other hand, in cases of concretes without chlorides, the effect of the cover thickness in the readings or corrosion potential was irrelevant. All this information was proved with 95% of statistical significance.

Chloride-Reinforced Carbon Nanofiber Host as Effective Polysulfide Traps in Lithium-Sulfur Batteries.

Science.gov (United States)

Fan, Lei; Zhuang, Houlong L; Zhang, Kaihang; Cooper, Valentino R; Li, Qi; Lu, Yingying

2016-12-01

Lithium-sulfur (Li-S) battery is one of the most promising alternatives for the current state-of-the-art lithium-ion batteries due to its high theoretical energy density and low production cost from the use of sulfur. However, the commercialization of Li-S batteries has been so far limited to the cyclability and the retention of active sulfur materials. Using co-electrospinning and physical vapor deposition procedures, we created a class of chloride-carbon nanofiber composites, and studied their effectiveness on polysulfides sequestration. By trapping sulfur reduction products in the modified cathode through both chemical and physical confinements, these chloride-coated cathodes are shown to remarkably suppress the polysulfide dissolution and shuttling between lithium and sulfur electrodes. From adsorption experiments and theoretical calculations, it is shown that not only the sulfide-adsorption effect but also the diffusivity in the vicinity of these chlorides materials plays an important role on the reversibility of sulfur-based cathode upon repeated cycles. Balancing the adsorption and diffusion effects of these nonconductive materials could lead to the enhanced cycling performance of an Li-S cell. Electrochemical analyses over hundreds of cycles indicate that cells containing indium chloride-modified carbon nanofiber outperform cells with other halogenated salts, delivering an average specific capacity of above 1200 mAh g -1 at 0.2 C.

Simultaneous Determination of Chelating Agents by Ion-Suppression and Ion-Pair Chromatography in Wastewater

International Nuclear Information System (INIS)

Dodi, Alain; Bouscarel, Maelle

2008-01-01

This article describes two methods for analysing chelating agents found in nuclear waste. First, ion-suppression chromatography using an anion exchange stationary phase and mobile phase consisting of a nitric acid solution and pure water gradient. UV detection was performed at 330 nm after the reaction with a post-column reagent composed of iron nitrate in perchloric acid. Secondly, ion-pair chromatography with a mobile phase consisting of a mixture of nitric acid, tetra-butyl-ammonium hydrogeno-sulphate, tetra-butyl-ammonium hydroxide and iron chloride. A reversed-phase material was used as a stationary phase and detection was performed by direct measurement of the UV absorption at 260 nm. The quantification limits were lower for ion-pair chromatography than for ion-suppression chromatography. Both methods were easy to implement and allow a multi-element separation in less than 30 min with low detection limits. (authors)

Simultaneous Determination of Chelating Agents by Ion-Suppression and Ion-Pair Chromatography in Wastewater

Energy Technology Data Exchange (ETDEWEB)

Dodi, Alain; Bouscarel, Maelle [Commissariat a l' energie atomique - C.E.A, Centre d' Etude de Cadarache, Laboratoire d' Analyses Radiochimiques et Chimiques, St Paul lez Durance (France)

2008-07-01

This article describes two methods for analysing chelating agents found in nuclear waste. First, ion-suppression chromatography using an anion exchange stationary phase and mobile phase consisting of a nitric acid solution and pure water gradient. UV detection was performed at 330 nm after the reaction with a post-column reagent composed of iron nitrate in perchloric acid. Secondly, ion-pair chromatography with a mobile phase consisting of a mixture of nitric acid, tetra-butyl-ammonium hydrogeno-sulphate, tetra-butyl-ammonium hydroxide and iron chloride. A reversed-phase material was used as a stationary phase and detection was performed by direct measurement of the UV absorption at 260 nm. The quantification limits were lower for ion-pair chromatography than for ion-suppression chromatography. Both methods were easy to implement and allow a multi-element separation in less than 30 min with low detection limits. (authors)

Isotherms of ion exchange on titanates of alkaline metals

International Nuclear Information System (INIS)

Fillina, L.P.; Belinskaya, F.A.

1986-01-01

Present article is devoted to isotherms of ion exchange on titanates of alkaline metals. Therefore, finely dispersed hydrated titanates of alkaline metals (lithium, sodium, potassium) with ion exchange properties are obtained by means of alkaline hydrolysis of titanium chloride at high ph rates. Sorption of cations from salts solution of Li 2 SO 4 , NaNO 3 , Ca(NO 3 ) 2 , AgNO 3 by titanates is studied.

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

International Nuclear Information System (INIS)

Jegle, U.

1989-02-01

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

21 CFR 184.1138 - Ammonium chloride.

Science.gov (United States)

2010-04-01

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

21 CFR 184.1426 - Magnesium chloride.

Science.gov (United States)

2010-04-01

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

Removal of chloride from MSWI fly ash.

Science.gov (United States)

Chen, Wei-Sheng; Chang, Fang-Chih; Shen, Yun-Hwei; Tsai, Min-Shing; Ko, Chun-Han

2012-10-30

The high levels of alkali chloride and soluble metal salts present in MSWI fly ash is worth noting for their impact on the environment. In addition, the recycling or reuse of fly ash has become an issue because of limited landfill space. The chloride content in fly ash limits its application as basis for construction materials. Water-soluble chlorides such as potassium chloride (KCl), sodium chloride (NaCl), and calcium chloride hydrate (CaCl(2) · 2H(2)O) in fly ash are easily washed away. However, calcium chloride hydroxide (Ca(OH)Cl) might not be easy to leach away at room temperature. The roasting and washing-flushing processes were applied to remove chloride content in this study. Additionally, air and CO(2) were introduced into the washing process to neutralize the hazardous nature of chlorides. In comparison with the water flushing process, the roasting process is more efficient in reducing the process of solid-liquid separation and drying for the reuse of Cl-removed fly ash particles. In several roasting experiments, the removal of chloride content from fly ash at 1050°C for 3h showed the best results (83% chloride removal efficiency). At a solid to liquid ratio of 1:10 the water-flushing process can almost totally remove water-soluble chloride (97% chloride removal efficiency). Analyses of mineralogical change also prove the efficiency of the fly ash roasting and washing mechanisms for chloride removal. Copyright © 2012 Elsevier B.V. All rights reserved.

21 CFR 184.1193 - Calcium chloride.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true 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 commercially...

Conversion of borate ions in liquid phase. Izmenenie sostava borationov v zhidkoj faze

Energy Technology Data Exchange (ETDEWEB)

Gode, G K; Bernare, A A [Latvijskij Gosudarstvennyj Univ., Riga (USSR)

1989-01-01

Isomolar series of aquepus solutions of magnesium chloride and potassium tetraborate at 25 deg C are investigated by the refractometry method. It is established that inderite containing triborate-ion is crystalized from solutions of rather high concentration. In 0.1 M solution reagents form supersaturated solutions with the decreased refractive index against the calculated one. It is supposed that this deviation is caused by partial transformation of tetraborate-ion to triborate-ion under the magnesium ion effect.

Sodium and chloride levels in rainfall, mist. streamwater and groundwater at the Plynlimon catchments, mid-Wales: inferences on hydrological and chemical controls

Science.gov (United States)

Neal, C.; Kirchner, J. W.

Variations in sodium and chloride in atmospheric inputs (rainfall and mist), stream runoff and groundwater stores are documented for the upper Severn River (Afon Hafren and Afon Hore catchments), Plynlimon, mid-Wales. The results show five salient features. Sodium and chloride concentrations are highly variable and highly correlated in rainfall and mist. The sodium-chloride relationship in rainfall has a slope close to the sodium/chloride ratio in sea-water, and an intercept that is not significantly different from zero. This indicates that sea-salt is the dominant source of both sodium and chloride in rainfall, which would be expected given the maritime nature of the metrology. For mist, there is also a straight line with near-zero intercept, but with a slightly higher gradient than the sea-salt ratio, presumably due to small additional sodium inputs from other sources. There is an approximate input-output balance for both sodium and chloride, with the exception of one groundwater well, in which high chemical weathering results in an anomalous high Na/Cl ratio. Thus, atmospheric deposition is the dominant source of both sodium and chloride in groundwater and streamflow. The fluctuations in sodium and chloride concentrations in the streams and groundwaters are strongly damped compared to those in the rain and the mist, reflecting the storage and mixing of waters in the subsurface. On all timescales, from weeks to years, sodium fluctuations are more strongly damped than chloride fluctuations in streamflow. The additional damping of sodium is consistent with ion exchange buffering of sodium in the catchment soils. Sodium and chloride concentrations are linearly correlated in the streams and groundwaters, but the slope is almost universally less than the sea-salt ratio and there is a non-zero intercept. The Na/Cl ratio in streamflow and groundwater is higher than the sea-salt ratio when salinity is low and lower than the sea-salt ratio when salinity is high. This

Probing ion-specific effects on aqueous acetate solutions: Ion pairing versus water structure modifications.

Science.gov (United States)

Petit, Tristan; Lange, Kathrin M; Conrad, Gerrit; Yamamoto, Kenji; Schwanke, Christoph; Hodeck, Kai F; Dantz, Marcus; Brandenburg, Tim; Suljoti, Edlira; Aziz, Emad F

2014-05-01

The effect of monovalent cations (Li(+), K(+), NH4 (+), Na(+)) on the water structure in aqueous chloride and acetate solutions was characterized by oxygen K-edge X-ray absorption spectroscopy (XAS), X-ray emission spectroscopy, and resonant inelastic X-ray scattering (RIXS) of a liquid microjet. We show ion- and counterion dependent effects on the emission spectra of the oxygen K-edge, which we attribute to modifications of the hydrogen bond network of water. For acetates, ion pairing with carboxylates was also probed selectively by XAS and RIXS. We correlate our experimental results to speciation data and to the salting-out properties of the cations.

Probing ion-specific effects on aqueous acetate solutions: Ion pairing versus water structure modifications

Directory of Open Access Journals (Sweden)

Tristan Petit

2014-05-01

Full Text Available The effect of monovalent cations (Li+, K+, NH4+, Na+ on the water structure in aqueous chloride and acetate solutions was characterized by oxygen K-edge X-ray absorption spectroscopy (XAS, X-ray emission spectroscopy, and resonant inelastic X-ray scattering (RIXS of a liquid microjet. We show ion- and counterion dependent effects on the emission spectra of the oxygen K-edge, which we attribute to modifications of the hydrogen bond network of water. For acetates, ion pairing with carboxylates was also probed selectively by XAS and RIXS. We correlate our experimental results to speciation data and to the salting-out properties of the cations.

Ferric chloride modified zeolite in wastewater on Cr (VI) adsorption characteristics

Science.gov (United States)

Wu, Xiaoqing; Zhang, Kang; Chen, Wen; Zhang, Hua

2018-03-01

Zeolite was modified by ferric chloride(Fe-Z) removal Cr (VI) ion from wastewater. The results showed that the effect of Cr(VI) adsorption on modified zeolite depended significantly on pH. It is favorable for the adsorption of Cr(VI) in acid condition. The Langmuir isotherm model has high fitting accuracy with experimental data, demonstrated that is monolayer adsorption and chemical adsorption.The pseudo-second-order equation provided the best correlation to the data. The model can describe the adsorption reaction process well.

Pharmacokinetics of vinyl chloride in the rat

International Nuclear Information System (INIS)

Bolt, H.M.; Laib, R.J.; Kappus, H.; Buchter, A.

1977-01-01

When rats are exposed to [ 14 C]vinyl chloride in a closed system, the vinyl chloride present in the atmosphere equilibrates with the animals' organism within 15 min. The course of equilibration could be determined using rats which had been given 6-nitro-1,2,3-benzothiadiazole. This compound completely blocks metabolism of vinyl chloride. The enzymes responsible for metabolism of vinyl chloride are saturated at an atmospheric concentration of vinyl chloride of 250 ppm. Pharmacokinetic analysis shows that no significant cumulation of vinyl chloride or its major metabolites is to be expected on repeated administration of vinyl chlorides. This may be consistent with the theory that a reactive, shortly living metabolite which occurs in low concentration only, may be responsible for the toxic effects of vinyl chloride

Self diffusion of sodium ion in sodium chloride

International Nuclear Information System (INIS)

Haridasan, T.M.; Lawrence, N.

1985-09-01

The problem of cation self diffusion in NaCl for a single vacancy mechanism is attempted using a reaction coordinate approach employing the phonons in the system. The vacancy is given an active role by estimating the displacements of its nearest neighbour Cl - ions in the environment of the vacancy through the lattice Green's functions and the t matrix formalism. The jump frequency, the isotope effect and diffusion coefficients estimated by this approach agree well with the experimentally deduced values. These results support the experimental conclusion of about 30% of vacancy pairs in the cation diffusion in NaCl. (author)

Conversion of fuel hulls to zirconate ion exchangers for stabilization of wastes from the thorium fuel cycle

International Nuclear Information System (INIS)

Levine, H.S.

1978-01-01

A conceptual reprocessing and waste management scheme for Zircaloy clad ThO 2 fuel was formulated to eliminate problems associated with concurrent dissolution of fuel and cladding in the conventional chop-leach headend step. These problems are avoided by use of a modified headend step to form oxide fuel and cladding process streams. A chlorinating agent then converts the cladding hulls and adhering fuel into volatile and nonvolatile chloride fractions. The former product is processed, by use of the Zircaloy conversion process, to form an inorganic ion exchange material and combined with HLLW from subsequent fuel reprocessing to form a stable and refractory waste form. The nonvolatile chloride fraction would be recovered, processed to remove chloride ions, and recombined with the main oxide fuel process stream for further treatment by use of the Thorex process

Corrosion of steel drums containing cemented ion-exchange resins as intermediate level nuclear waste

Science.gov (United States)

Duffó, G. S.; Farina, S. B.; Schulz, F. M.

2013-07-01

Exhausted ion-exchange resins used in nuclear reactors are immobilized by cementation before being stored. They are contained in steel drums that may undergo internal corrosion depending on the presence of certain contaminants. The objective of this work is to evaluate the corrosion susceptibility of steel drums in contact with cemented ion-exchange resins with different aggressive species. The corrosion potential and the corrosion rate of the steel, and the electrical resistivity of the matrix were monitored for 900 days. Results show that the cementation of ion-exchange resins seems not to pose special risks regarding the corrosion of the steel drums. The corrosion rate of the steel in contact with cemented ion-exchange resins in the absence of contaminants or in the presence of 2.3 wt.% sulphate content remains low (less than 0.1 μm/year) during the whole period of the study (900 days). The presence of chloride ions increases the corrosion rate of the steel at the beginning of the exposure but, after 1 year, the corrosion rate drops abruptly reaching a value close to 0.1 μm/year. This is probably due to the lack of water to sustain the corrosion process. When applying the results obtained in the present work to estimate the corrosion depth of the steel drums containing the cemented radioactive waste after a period of 300 years, it is found that in the most unfavourable case (high chloride contamination), the corrosion penetration will be considerably lower than the thickness of the wall of the steel drums. Cementation of ion-exchange resins does not seem to pose special risks regarding the corrosion of the steel drums that contained them; even in the case the matrix is highly contaminated with chloride ions.

Determination of HCl and VOC Emission from Thermal Degradation of PVC in the Absence and Presence of Copper, Copper(II Oxide and Copper(II Chloride

Directory of Open Access Journals (Sweden)

Ahamad J. Jafari

2009-01-01

Full Text Available Polyvinyl chloride (PVC has played a key role in the development of the plastic industry over the past 40 years. Thermal degradation of PVC leads to formation of many toxic pollutants such as HCl, aromatic and volatile organic carbon vapors. Thermal degradation of PVC and PVC in the present of copper, cupric oxide and copper(II chloride were investigated in this study using a laboratory scale electrical furnace. HCl and Cl- ion were analyzed by a Dionex ion chromatograph and VOCs compounds were analyzed using GC or GC-MS. The results showed that HCl plus Cl- ion and benzene formed about 99% and 80% respectively in the first step of thermal degradation under air atmosphere. The presence of cupric oxide increases the percentage of short chain hydrocarbons more than 184% and decreases the amount of the major aromatic hydrocarbon and HCl plus Cl- ion to 90% and 65% respectively. The total aromatic hydrocarbon emitted less than when atmosphere was air and difference was statistically significant (Pvalue<0.000

Potentiometer determination of sulfur using silver/sulfur ion selective electrodes; Determinacion potenciometrica de sulfuros mediante electrodo-ion-selectivo de plata/sulfuro

Energy Technology Data Exchange (ETDEWEB)

Salamanca Grosso, G. [Departamento de Quimica, Instituto de Ciencias, Universidad de Tolima, Tolima (Colombia)

1996-06-01

New devices in analytical chemistry, has been emerged, and new procedures take great interest. The use of electrodes ion selective are very important in water and wastewater control of Ag+/S= electrodes for control process in wastewater from UASE plan pilot, before check their potentiometric performance so: 28.6+- 0.4 mV/decade, optimal time 20 seconds, and pH>10, detection limit 1.8 x 10``-6. The study was made in comparative way with yodometrical method: we check quantification by addition, subtraction an GRANT`s titrimetric. (Author) 10 refs.

Chloride Ingress in Concrete with Different Age at Time of First Chloride Exposure

DEFF Research Database (Denmark)

Hansen, Esben Østergaard; Iskau, Martin Riis; Hasholt, Marianne Tange

2016-01-01

Concrete structures cast in spring have longer time to hydrate and are therefore denser and more resistant to chloride ingress when first subjected to deicing salts in winter than structures cast in autumn. Consequently, it is expected that a spring casting will have a longer service life....... This hypothesis is investigated in the present study by testing drilled cores from concrete cast in 2012 and 2013 on the Svendborgsund Bridge. The cores are subject to petrographic examination and mapping of chloride profiles. Moreover, chloride migration coefficients have been measured. The study shows...

Ion exchange purification of scandium

Science.gov (United States)

Herchenroeder, Laurie A.; Burkholder, Harvey R.

1990-10-23

An improvement in purification of scandium through ion exchange chromatography is disclosed in which the oxidation potential of the eluting solution is altered by the addition of potassium chlorate or ammonium chloride so that removal of contaminants is encouraged. The temperature, pH and concentration of the eluent HEDTA are controlled in order to maintain the scandium in the column while minimizing dilution of the scandium band. Recovery of scandium is improved by pumping dilute scandium over the column prior to stripping the scandium and precipitation. This eliminates the HEDTA ion and other monovalent cations contaminating the scandium band. This method maximizes recovery of scandium while maintaining purity.

Effect of chloride impurities on the performance and durability of polybenzimidazole-based high temperature proton exchange membrane fuel cells

DEFF Research Database (Denmark)

Ali, Syed Talat; Li, Qingfeng; Pan, Chao

2011-01-01

The effect of chloride as an air impurity and as a catalyst contaminant on the performance and durability of polybenzimidazole (PBI)-based high temperature proton exchange membrane fuel cell (HT-PEMFC) was studied. The ion chromatographic analysis reveals the existence of chloride contaminations....... The performance loss was recovered when switching from the HCl solution back to pure water in the air humidifier. Under an accelerated aging performance test conducted through potential cycling between 0.9 V and 1.2 V, the PBI-based fuel cell initially containing 0.5 NaCl mg cm−2 on the cathode catalyst layer...

Producing ammonium chloride from coal or shale

Energy Technology Data Exchange (ETDEWEB)

Christenson, O L

1921-02-25

Process of producing ammonium chloride consists of mixing the substance to be treated with a chloride of an alkali or alkaline earth metal, free silica, water and free hydrochloric acid, heating the mixture until ammonium chloride distills off and collecting the ammonium chloride.

Crown Ether Complexes of Alkali-Metal Chlorides from SO2.

Science.gov (United States)

Reuter, Kirsten; Rudel, Stefan S; Buchner, Magnus R; Kraus, Florian; von Hänisch, Carsten

2017-07-18

The structures of alkali-metal chloride SO 2 solvates (Li-Cs) in conjunction with 12-crown-4 or 1,2-disila-12-crown-4 show strong discrepancies, despite the structural similarity of the ligands. Both types of crown ethers form 1:1 complexes with LiCl to give [Li(1,2-disila-12-crown-4)(SO 2 Cl)] (1) and [Li(12-crown-4)Cl]⋅4 SO 2 (2). However, 1,2-disila-12-crown-4 proved unable to coordinate cations too large for the cavity diameter, for example, by the formation of sandwich-type complexes. As a result, 12-crown-4 reacts exclusively with the heavier alkali-metal chlorides NaCl, KCl and RbCl. Compounds [Na(12-crown-4) 2 ]Cl⋅4 SO 2 (3) and [M(12-crown-4) 2 (SO 2 )]Cl⋅4 SO 2 (4: M=K; 5: M=Rb) all showed S-coordination to the chloride ions through four SO 2 molecules. Compounds 4 and 5 additionally exhibit the first crystallographically confirmed non-bridging O,O'-coordination mode of SO 2 . Unexpectedly, the disila-crown ether supports the dissolution of RbCl and CsCl in the solvent and gives the homoleptic SO 2 -solvated alkali-metal chlorides [MCl⋅3 SO 2 ] (6: M=Rb; 7: M=Cs), which incorporate bridging μ-O,O'-coordinating moieties and the unprecedented side-on O,O'-coordination mode. All compounds were characterised by single-crystal X-ray diffraction. The crown ether complexes were additionally studied by using NMR spectroscopy, and the presence of SO 2 at ambient temperature was revealed by IR spectroscopy of the neat compounds. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Chloride secretagogues stimulate inositol phosphate formation in shark rectal gland tubules cultured in suspension

International Nuclear Information System (INIS)

Ecay, T.W.; Valentich, J.D.

1991-01-01

Neuroendocrine activation of transepithelial chloride secretion by shark rectal gland cells is associated with increases in cellular cAMP, cGMP, and free calcium concentrations. We report here on the effects of several chloride secretagogues on inositol phosphate formation in cultured rectal gland tubules. Vasoactive intestinal peptide (VIP), atriopeptin (AP), and ionomycin increase the total inositol phosphate levels of cultured tubules, as measured by ion exchange chromatography. Forskolin, a potent chloride secretagogue, has no effect on inositol phosphate formation. The uptake of 3 H-myo-inositol into phospholipids is very slow, preventing the detection of increased levels of inositol trisphosphate. However, significant increases in inositol monophosphate (IP1) and inositol biphosphate (IP2) were measured. The time course of VIP- and AP-stimulated IP1 and IP2 formation is similar to the effects of these agents on the short-circuit current responses of rectal gland monolayer cultures. In addition, aluminum fluoride, an artificial activator of guanine nucleotide-binding proteins, stimulates IP1 and IP2 formation. We conclude that rectal gland cells contain VIP and AP receptors coupled to the activation of phospholipase C. Coupling may be mediated by G-proteins. Receptor-stimulated increases in inositol phospholipid metabolism is one mechanism leading to increased intracellular free calcium concentrations, an important regulatory event in the activation of transepithelial chloride secretion by shark rectal gland epithelial cells