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Sample records for chloride ingress prediction

  1. 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...

  2. Chloride ingress prediction

    DEFF Research Database (Denmark)

    Frederiksen, Jens Mejer; Geiker, Mette Rica

    Prediction of chloride ingress into concrete is an important part of durability design of reinforced concrete structures exposed to chloride containing environment. This paper presents 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...

  3. Chloride ingress prediction

    DEFF Research Database (Denmark)

    Frederiksen, Jens Mejer; Geiker, Mette Rica

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

  4. Chloride ingress prediction

    DEFF Research Database (Denmark)

    Frederiksen, Jens Mejer; Geiker, Mette Rica

    2008-01-01

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

  5. Prediction of chloride ingress and binding in cement paste

    DEFF Research Database (Denmark)

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

    2007-01-01

    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...... steady state diffusion however. It simply implies that incremental increases in the concentration of diffusing ions in the pore solution will rapidly re-equilibrate with the hydrates present locally, where, the greater the ratio of bound to free ions, the greater the buffering effect which slows down the...

  6. Chloride ingress in cement paste and mortar

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede; Hansen, Per Freiesleben; Coats, Alison M.; Glasser, Fred P.

    1999-01-01

    In this paper chloride ingress in cement paste and mortar is followed by electron probe microanalysis. The influence of several paste and exposure parameters on chloride ingress are examined (e.g., water-cement ratio, silica fume addition, exposure time, and temperature), The measurements are...

  7. Chloride ingress in cement paste and mortar

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede; Hansen, Per Freiesleben; Coats, Alison M.;

    1999-01-01

    modelled on Fick's law modified by a term for chloride binding. Inclusion of chloride binding significantly improves the profile shape of the modelled ingress profiles. The presence of fine aggregate and formation of interfacial transition zones at paste-aggregate boundaries does not significantly affect...

  8. Chloride Ingress in Concrete Cracks under Cyclic Loading

    DEFF Research Database (Denmark)

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

    2005-01-01

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

  9. Probabilistic Models and Computational Methods for Chloride Ingress in Concrete

    DEFF Research Database (Denmark)

    Engelund, S.

    Within the last decades it has been recognized that reinforced concrete structures are subject to a number of destructive mechanisms which might affect the structure in such a way that it is not able to fulfil its purpose efficiently. The present report focuses on chloride ingress and chloride-in...

  10. Chloride ingress in cement paste and mortar measured by Electron Probe Micro Analysis

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede

    1998-01-01

    Chloride ingress is a common cause of deterioration of reinforced concrete structures. Concrete may be exposed to chloride by sea water or deicing salts. The chloride initiates corrosion of the reinforcement which through expansion disrupts the concrete. Modelling the chloride ingress is an.......Chloride ingress in modern concretes cannot be followed with conventional measuring techniques. This makes it difficult to develop and test new models. However, prefatory experiments have shown that electron probe micro analysis, EPMA, is applicable for this purpose. The geometric resolution for the EPMA method is...

  11. Interactions between chloride ingress and carbonation in cementitious materials

    OpenAIRE

    SAILLIO, Mickael; BARBERON, Fabien; BAROGHEL BOUNY, Véronique; GEGOUT, Philippe; PLATRET, Gérard; D'ESPINOSE DE LA CAILLERIE, JB

    2011-01-01

    Carbonation and chloride attacks are the major causes of reinforced concrete (RC) structure deterioration by initiation of steel rebar corrosion. These attacks are usually studied separately in the literature. Chloride-induced corrosion takes place mainly in marine environment or in the case of contact with deicing salts, while carbonation is systematically present in all RC structures at a variable degree. Since carbonation leads to significant microstructure changes, the effect of chloride ...

  12. Finite Element Reliability Analysis of Chloride Ingress into Reinforced Concrete Structures

    DEFF Research Database (Denmark)

    Frier, Christian; Sørensen, John Dalsgaard

    2007-01-01

    For many reinforced concrete structures corrosion of the reinforcement is an important problem since it can result in maintenance and repair actions. Further, a reduction of the load-bearing capacity can occur. In the present paper the Finite Element Reliability Method (FERM) is employed for...... obtaining the probability of exceeding a critical chloride concentration level at the reinforcement bars, both using Monte Carlo Simulation (MCS) and the First Order Reliability Method (FORM). The chloride ingress is modelled by the Finite Element Method (FEM) and the diffusion coefficient, surface chloride...... concentration and reinforcement cover depth are modelled by stochastic fields, which are discretized using the Expansion Optimum Linear Estimation (EOLE) approach. The response gradients needed for FORM analysis are derived analytically using the Direct Differentiation Method (DDM). As an example, a bridge pier...

  13. Stochastic Simulation of Chloride Ingress into Reinforced Concrete Structures by Means of Multi-Dimensional Gaussian Random Fields

    DEFF Research Database (Denmark)

    Frier, Christian; Sørensen, John Dalsgaard

    2005-01-01

    For many reinforced concrete structures corrosion of the reinforcement is an important problem since it can result in expensive maintenance and repair actions. Further, a significant reduction of the load-bearing capacity can occur. One mode of corrosion initiation occurs when the chloride content...... around the reinforcement exceeds a critical threshold value. In the present paper FERM (the Finite Element Reliability Method) is employed for obtaining the probability of exceeding a critical chloride concentration level at the reinforcement bars using MCS (Monte Carlo Simulation). The chloride ingress...... is modeled by a 2-dimensional diffusion process by FEM (Finite Element Method) and the diffusion coefficient, surface chloride concentration and reinforcement cover depth are modeled by multidimensional stochastic fields, which are discretized using the EOLE (Expansion Optimum Linear Estimation...

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

    DEFF Research Database (Denmark)

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

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    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.

  16. Two-and Three-Dimensional Chloride Ingress into Fly Ash Concrete

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yunsheng; SUN Wei; CHEN Shudong; GUO Fei

    2011-01-01

    2D,3D chloride ion concentration at the edge and comer zones were systematically investigated for fly ash concretes made with different cement replacement percentage by fly ash (0%,10%,20%,40%,60%),water to binder ratios (0.3,0.35,0.4),and curing ages (28 d,90 d).An interaction effect caused by 2D and 3D diffusion could obviously be observed through the comparison with 1D testing results.In order to quantify the interaction effect,2D and 3D diffusion interaction coefficients was proposed in this paper.Finally,the changes of 2D and 3D interaction coefficients with the change in the free chloride ion concentration were given.The above research provide an insight into chloride ion attack on the edge and comer reinforcing bars of concrete structures in the field of civil engineering.

  17. Stochastic Analysis of the Multi-dimensional Effect of Chloride Ingress into Reinforced Concrete

    DEFF Research Database (Denmark)

    Frier, Christian; Sørensen, John Dalsgaard

    2007-01-01

    For many reinforced concrete structures corrosion of the reinforcement is an important problem since it can result in expensive maintenance and repair actions. One mode of corrosion initiation occurs when the chloride content around the reinforcement bars exceeds a critical threshold value, which...

  18. A Probabilistic Model for Chloride-Ingress and Initation of Corrosion in Reinforced Concrete Structures

    DEFF Research Database (Denmark)

    Engelund, S.; Sørensen, John Dalsgaard

    1998-01-01

    Corrosion of the reinforcement is a major problem for a large number of reinforced concrete structures because it can lead to a substantial decrease of the load-bearing capacity. One mode of corrosion initiation is that the chloride content around the reinforcement exceeds a critical threshold va...

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

    OpenAIRE

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

    2009-01-01

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

  20. Development of a model to predict fission product behaviour in spherical fuel elements during water ingress events

    International Nuclear Information System (INIS)

    At PBMR gaseous fission product releases from spherical fuel elements under normal conditions are calculated by the code NOBLEG. The ability of NOBLEG to calculate noble gas and halogen release under oxidizing conditions during water ingress was developed. Observations made during the water vapour injection tests performed during the irradiation experiment HFR-K6, were used to determine simple relations that can be used to predict gaseous fission product release from spherical fuel elements under oxidizing conditions caused by small water ingress events, for PBMR operational temperatures. A new model was proposed to explain peculiarities observed during the water injection tests

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

    OpenAIRE

    Ghahari, S. A.; Ramezanianpour, A. M.; Ramezanianpour, A. A.; Esmaeili, M

    2016-01-01

    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 c...

  2. Which toolkit for durability evaluation as regards chloride ingress into concrete ? Part II : Development of a performance approach based on durability indicators and monitoring parameters

    OpenAIRE

    BAROGHEL BOUNY, V

    2002-01-01

    This paper series includes two parts : I - Comparison between various methods for assessing the chloride diffusion coefficient of concrete in saturated conditions, and II - Development of a performance approach based on durability indicators and monitoring parameters. The chloride diffusion coefficient appears as a key-parameter in the theorical laws involved in transfer-related durability of concrete, an hence in the prediction of the service lifetime of reinforced structures. Consequently, ...

  3. Isothermal air ingress validation experiments

    International Nuclear Information System (INIS)

    Idaho National Laboratory carried out air ingress experiments as part of validating computational fluid dynamics (CFD) calculations. An isothermal test loop was designed and set to understand the stratified-flow phenomenon, which is important as the initial air flow into the lower plenum of the very high temperature gas cooled reactor (VHTR) when a large break loss-of-coolant accident occurs. The unique flow characteristics were focused on the VHTR air-ingress accident, in particular, the flow visualization of the stratified flow in the inlet pipe to the vessel lower plenum of the General Atomic's Gas Turbine-Modular Helium Reactor (GT-MHR). Brine and sucrose were used as heavy fluids, and water was used to represent a light fluid, which mimics a counter current flow due to the density difference between the stimulant fluids. The density ratios were changed between 0.87 and 0.98. This experiment clearly showed that a stratified flow between simulant fluids was established even for very small density differences. The CFD calculations were compared with experimental data. A grid sensitivity study on CFD models was also performed using the Richardson extrapolation and the grid convergence index method for the numerical accuracy of CFD calculations . As a result, the calculated current speed showed very good agreement with the experimental data, indicating that the current CFD methods are suitable for predicting density gradient stratified flow phenomena in the air-ingress accident. (author)

  4. ISOTHERMAL AIR INGRESS VALIDATION EXPERIMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Chang H Oh; Eung S Kim

    2011-09-01

    Idaho National Laboratory carried out air ingress experiments as part of validating computational fluid dynamics (CFD) calculations. An isothermal test loop was designed and set to understand the stratified-flow phenomenon, which is important as the initial air flow into the lower plenum of the very high temperature gas cooled reactor (VHTR) when a large break loss-of-coolant accident occurs. The unique flow characteristics were focused on the VHTR air-ingress accident, in particular, the flow visualization of the stratified flow in the inlet pipe to the vessel lower plenum of the General Atomic’s Gas Turbine-Modular Helium Reactor (GT-MHR). Brine and sucrose were used as heavy fluids, and water was used to represent a light fluid, which mimics a counter current flow due to the density difference between the stimulant fluids. The density ratios were changed between 0.87 and 0.98. This experiment clearly showed that a stratified flow between simulant fluids was established even for very small density differences. The CFD calculations were compared with experimental data. A grid sensitivity study on CFD models was also performed using the Richardson extrapolation and the grid convergence index method for the numerical accuracy of CFD calculations . As a result, the calculated current speed showed very good agreement with the experimental data, indicating that the current CFD methods are suitable for predicting density gradient stratified flow phenomena in the air-ingress accident.

  5. Long-term mapping of the chloride load around a Swedish highway exposed to de-icing salt - with reference to reinforcement corrosion in concrete

    OpenAIRE

    Fagerlund, Göran

    2005-01-01

    In this report, a long-term study of the chloride environment around a highway exposed to severe de-icing is presented. The aim of the study was to obtain data that might be used for predictions of chloride ingress in de-iced structures and thereby provide necessary input to models for service life prediction.

  6. Durable concrete for a waste repository - Measurement of ionic ingress

    International Nuclear Information System (INIS)

    A waste repository for the below ground disposal of low level radioactive waste is planned at Chalk River Nuclear Laboratories. It relies greatly on the durability of concrete for the required 500 year service life. A research program to design durable concrete and predict its service life is in progress. The degradation of the concrete depends to a large extent on the rate of ingress of corrosive agents. Penetration of chloride and sulfate ions are particularly relevant. Twenty mix formulations were developed to create various types and qualities of concrete, and to study their behavior in different site environmental conditions. A total of 1,000 concrete specimens are being exposed at 20C and 45C to 25 different combinations of the corrosive agents including CO2. Procedures to measure the ionic profiles and to determine the factors controlling diffusion of the ions in the various concretes have been developed. Results of selected concrete systems exposed to chloride and sulfate solutions for 1 year are presented and discussed in terms of pore structure and permeability parameters of the concrete

  7. Small Break Air Ingress Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Chang Oh; Eung Soo Kim

    2011-09-01

    The small break air-ingress experiment, described in this report, is designed to investigate air-ingress phenomena postulated to occur in pipes in a very high temperature gas-cooled reactor (VHTRs). During this experiment, air-ingress rates were measured for various flow and break conditions through small holes drilled into a pipe of the experimental apparatus. The holes were drilled at right angles to the pipe wall such that a direction vector drawn from the pipe centerline to the center of each hole was at right angles with respect to the pipe centerline. Thus the orientation of each hole was obtained by measuring the included angle between the direction vector of each hole with respect to a reference line anchored on the pipe centerline and pointing in the direction of the gravitational force. Using this reference system, the influence of several important parameters on the air ingress flow rate were measured including break orientation, break size, and flow velocity . The approach used to study the influence of these parameters on air ingress is based on measuring the changes in oxygen concentrations at various locations in the helium flow circulation system as a function of time using oxygen sensors (or detectors) to estimate the air-ingress rates through the holes. The test-section is constructed of a stainless steel pipe which had small holes drilled at the desired locations.

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

    OpenAIRE

    Mohammad K. Alkam; Maha Alqam

    2015-01-01

    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 ...

  9. Chloride Penetration Prediction in Concrete through an Empirical Model Based on Constant Flux Diffusion

    OpenAIRE

    Vera Almenar, Guillem de; Climent, Miguel-Ángel; Viqueira Pérez, Estanislao; Antón Gil, Carlos; López García, María Pilar

    2014-01-01

    An empirical model based on constant flux is presented for chloride transport through concrete in atmospherical exposure conditions. A continuous supply of chlorides is assumed as a constant mass flux at the exposed concrete surface. The model is applied to experimental chloride profiles obtained from a real marine structure, and results are compared with the classical error-function model. The proposed model shows some advantages. It yields a better predictive capacity than the classical err...

  10. Progress of Carbonation in Chloride Contaminated Concretes

    OpenAIRE

    Wang, Yaocheng; Basheer, P.A.M.; Nanukuttan, S; Bai, Y.

    2016-01-01

    Concretes used in marine environment are generally under the cyclic effect of CO2 and chloride ions (Cl-). To date, the influence of carbonation on ingress of chloride ions in concretes has been widely studied; in comparison, study on the influence of Cl- on the progress of carbonation is limited. During the study, concretes were exposed to independent and combined mechanisms of carbonation and chloride ingress regimes. Profiles of apparent pH and chloride concentration were used to indicate ...

  11. Development of chloride attack prediction model for concrete structure of NPP

    International Nuclear Information System (INIS)

    Material properties and structural performance of Nuclear Power Plant structures subjected to physical and environmental factors, degrade during life time due to continuous deterioration such as rebar corrosion and concrete cracking. In special NPP structures are exposed to chloride environment since they are located in seashore area. In this study, a chloride attack prediction model is developed to predict corrosion initiation of reinforcing bars in NPP structures, based on governing equations that take into account the diffusion of chloride ions and a mechanical steady state. It can offer information which is used to determine an optimal time for repair and rehabilitation actions of the structure

  12. Study of water ingression models

    International Nuclear Information System (INIS)

    It is important to understand the mechanisms of quenching molten corium material when estimating the safety of nuclear plants. The melt freezes creating an impermeable crust when water is injected on the top of the molten pool. The heat is carried away from the melt only by conduction through the crust and thus the cooling rate decreases as the crust grows. Cracking of the crust allows water to penetrate into the crust making conduction layer thinner and increasing the cooling rate. This is called water ingression. The water ingression model presented here is partly based on experimental data obtained for rocks, and thus it is not clear if it can be used in the case of corium pools. If it is permissible to extrapolate this theory to relatively hightemperature corium, the water ingression is not possible with the corium pools. However, the theory is sensitive to errors with high temperatures. Experiments have shown that the cooling rate of the corium pools is higher than it should be with conduction only and careful analyses of experiments are required to verify the nature and scale of water ingression process. (orig.)

  13. Characteristics of Water Ingress in Norwegian Subsea Tunnels

    Science.gov (United States)

    Nilsen, Bjørn

    2014-05-01

    Water ingress represents one of the main challenges in subsea tunnelling, particularly when this occurs in sections with poor rock mass quality. This paper is discussing the main characteristics of water ingress in subsea hard rock tunnels based on the experience from almost 50 such tunnels that have been built in Norway. Following a brief description of the geological conditions and the basic design of the subsea tunnels, pre-construction investigations and investigations during excavation are discussed with particular emphasis on prediction of water ingress. Two cases with particularly difficult conditions; the Bjorøy tunnel and the Atlantic Ocean tunnel, are discussed in detail. In these cases, large water inflow with pressure of up to 2.4 MPa was encountered at major faults/weakness zones during excavation, and special procedures were required to cope with the problems. Based on the experience from the Norwegian projects, it is concluded that continuous follow-up by experienced engineering geologists, probe drilling with the drilling jumbo and pre-grouting where required are the most important factors for coping with water ingress and ensuring stability.

  14. Study of Air Ingress Across the Duct During the Accident Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Hassan, Yassin [Texas A & M Univ., College Station, TX (United States)

    2013-05-06

    The goal of this project is to study the fundamental physical phenomena associated with air ingress in very high temperature reactors (VHTRs). Air ingress may occur due to a rupture of primary piping and a subsequent breach in the primary pressure boundary in helium-cooled and graphite-moderated VHTRs. Significant air ingress is a concern because it introduces potential to expose the fuel, graphite support rods, and core to a risk of severe graphite oxidation. Two of the most probable air ingress scenarios involve rupture of a control rod or fuel access standpipe, and rupture in the main coolant pipe on the lower part of the reactor pressure vessel. Therefore, establishing a fundamental understanding of air ingress phenomena is critical in order to rationally evaluate safety of existing VHTRs and develop new designs that minimize these risks. But despite this importance, progress toward development these predictive capabilities has been slowed by the complex nature of the underlying phenomena. The combination of inter-diffusion among multiple species, molecular diffusion, natural convection, and complex geometries, as well as the multiple chemical reactions involved, impose significant roadblocks to both modeling and experiment design. The project team will employ a coordinated experimental and computational effort that will help gain a deeper understanding of multiphased air ingress phenomena. This project will enhance advanced modeling and simulation methods, enabling calculation of nuclear power plant transients and accident scenarios with a high degree of confidence. The following are the project tasks: Perform particle image velocimetry measurement of multiphase air ingresses; and, Perform computational fluid dynamics analysis of air ingress phenomena.

  15. Study of Air Ingress Across the Duct During the Accident Conditions

    International Nuclear Information System (INIS)

    The goal of this project is to study the fundamental physical phenomena associated with air ingress in very high temperature reactors (VHTRs). Air ingress may occur due to a rupture of primary piping and a subsequent breach in the primary pressure boundary in helium-cooled and graphite-moderated VHTRs. Significant air ingress is a concern because it introduces potential to expose the fuel, graphite support rods, and core to a risk of severe graphite oxidation. Two of the most probable air ingress scenarios involve rupture of a control rod or fuel access standpipe, and rupture in the main coolant pipe on the lower part of the reactor pressure vessel. Therefore, establishing a fundamental understanding of air ingress phenomena is critical in order to rationally evaluate safety of existing VHTRs and develop new designs that minimize these risks. But despite this importance, progress toward development these predictive capabilities has been slowed by the complex nature of the underlying phenomena. The combination of inter-diffusion among multiple species, molecular diffusion, natural convection, and complex geometries, as well as the multiple chemical reactions involved, impose significant roadblocks to both modeling and experiment design. The project team will employ a coordinated experimental and computational effort that will help gain a deeper understanding of multiphased air ingress phenomena. This project will enhance advanced modeling and simulation methods, enabling calculation of nuclear power plant transients and accident scenarios with a high degree of confidence. The following are the project tasks: Perform particle image velocimetry measurement of multiphase air ingresses; and, Perform computational fluid dynamics analysis of air ingress phenomena.

  16. Googles Augmented-Reality-Game "Ingress"

    Directory of Open Access Journals (Sweden)

    Karl H. Stingeder

    2013-12-01

    Full Text Available Das an das "Geocoaching"-Spielprinzip erinnernde Augmented-­Reality-Game "Ingress" ist auf allen mit Android-Betriebssystem ausgestatteten Smartphones spielbar. Das Alleinstellungsmerkmal des Spiels ist gleich­zeitig auch das beste Patent-Rezept für bzw. gegen notorisches "Couch-Potato-ing": Das Game-Design des "Draußenspiels" erfordert jedoch stets die physische Anwesenheit der SpielerInnen am realen Ort des Geschehens, meist touristisch attraktive Sehenswürdigkeiten und architektonisch markante Plätze. Sobald "Ingress" per App am Smart­phone gestartet wird, stehen Interaktionen und Machtverhältnisse auf dem Handy-Display im Dreh- und Angelpunkt des Geschehens. Die Spielgrafik ist auf das Wesentliche reduziert und erinnert an die Optik von Videospielen der 80er Jahre. "Ingress" im Allgemeinen sowie "Magnus13", die erste von Google organisierte Fan-Veranstaltung Österreichs mit mehreren Hundert TeilnehmerInnen und ist mit einer "digitalen Schnitzeljagd" vergleichbar: Gemeinsam ist der klassischen "Schnitzeljagd" und dem digitalen "Schere-Schein-Papier" Prinzip von "Ingress" die tragende Rolle des im Spiel entstehenden Gemeinschaftsgefühls, welche in einer hohen Langzeitmotivation mündet. Trotz aller Euphorie, ob des unkonventionellen Augmented-Reality-Spielkonzepts und des in Folge der sozialen Dynamik außergewöhnlichen Sucht­potentials, ist angesichts von Edward Snowden und vielfältiger NSA-Abhörmaßnahmen, eine gesunde Portion Skepsis angebracht: Welchen Zweck erfüllt "Ingress"? Gibt es ein verhülltes "Mittel zum Zweck"? Welche Gefahren bestehen mit einer systematischen Auswertung des umfangreichen, ortsrelevanten Daten-Sammelsuriums? "Ingress" verdeutlicht trotz aller Risiken den soziokulturellen Bedeutungswandel des digitalen Spiels: Spiele per se und das Spiel als soziale Interaktion sind aktuell dabei, alle Bereiche unseres Lebens zu erfassen.

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

    Institute of Scientific and Technical Information of China (English)

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

    2004-01-01

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

  18. Assessment of NGNP Moisture Ingress Events

    Energy Technology Data Exchange (ETDEWEB)

    Bill Landman

    2011-04-01

    An assessment of modular HTGR moisture ingress events, making use of a phenomena identification and ranking process, was conducted by a panel of experts in the related areas for the U.S. next generation nuclear plant (NGNP) design. Consideration was given mainly to the prismatic core gas-cooled reactor configurations incorporating a steam generator within the primary circuit.

  19. Chloride-mass-balance for predicting increased recharge after land-use change

    OpenAIRE

    Gee, G.W.; Z. F. Zhang; Tyler, S.W.; Albright, W.H.; Singleton, M.J.

    2004-01-01

    The chloride-mass-balance (CMB) method has been used extensively to estimate recharge in arid and semi-arid environments. Required data include estimates of annual precipitation, total chloride input (from dry fallout and precipitation), and pore-water chloride concentrations. Typically, CMB has been used to estimate ancient recharge but recharge from recent land-use change has also been documented. Recharge rates below a few mm/yr are reliably detected with CMB; however, estimates above...

  20. Damage risks and economic assessment of climate adaptation strategies for design of new concrete structures subject to chloride-induced corrosion

    OpenAIRE

    Bastidas-Arteaga, Emilio; Stewart, Mark G.

    2015-01-01

    Reinforced concrete (RC) structures are subject to environmental actions affecting their performance, serviceability and safety. Among these actions, chloride ingress leads to corrosion initiation and its interaction with service loading could reduce its operational life. Experimental evidence indicates that chloride ingress is highly influenced by weather conditions in the surrounding environment and therefore by climate change. Consequently, both structural design and maintenance should be ...

  1. Air ingress behavior during a primary-pipe rupture accident of HTGR

    International Nuclear Information System (INIS)

    The inherent properties of a HTGR facilitates the design with high degree of passive safe performances, compared to other type. However, it is still not clear if the present HTGR can maintain a passive safe function during a primary-pipe rupture accident, or what would be design criteria to guarantee the HTGR with the high degree of passive safe performances during the accident. To investigate safe characteristics, the study has been performed experimentally and analytically on the air ingress behavior during the accident. It was indicated that there are two stages in the accident of the HTGR having a reverse U-shaped channel. In the first stage, an air ingress process limits molecular diffusion and natural circulation of the gas mixture having a very slow velocity. In the second stage, the air ingress process limits the ordinary natural circulation of air throughout the reactor. A numerical calculation code has been developed to analyze thermal-hydraulic behavior during the first stage. This code provides a numerical method for analyzing a transport phenomena in a multi-component gas system by solving one-dimensional basic equations and using a flow network model. It was possible to predict or analyze the air ingress process regarding the density of the gas mixture, concentration of each gas species and duration of the first stage of the accident. It was indicated that the safe characteristics of the HTGR from the present experiment as follows. The safety cooling rate that the air ingress process terminates during the first stage exists in the HTGR having the reverse U-shaped channel. Moreover, the ordinary natural circulation of air can not produce in the second stage by injecting helium from the bottom of the pressure vessel corresponding the low-temperature side channel. Therefore, it was found that the idea of helium injection is one of useful methods for the prevention of air ingress and of graphite corrosion in the future HTGRs. (J.P.N.). 74 refs

  2. Influence of sulphates on chloride diffusion and the effect of this on service life prediction of concrete in a submerged marine environment

    OpenAIRE

    Maes, M; Caspeele, R.; Van den Heede, P.; De Belie, N.

    2012-01-01

    Single-ion attack by chlorides and multi-ion attack by chlorides and sulphates were compared with respect to the full probabilistic service life prediction of concrete structures, according to fib Bulletin 34. Especially the influence of sulphates on the chloride diffusion coefficient was investigated more thoroughly. Four concrete mixtures were tested, two Portland cement concretes and two blast-furnace slag concretes. Migration tests and natural diffusion tests were executed, based on NT bu...

  3. Study of air ingress accident of an HTGR

    International Nuclear Information System (INIS)

    Inherent properties of high temperature gas cooled reactors (HTGR) facilitate the design of HTGRs with high degree of passive safety performances. In this context, it is very important to establish a design criteria for a passive safe function for the air ingress accident. However, it is absolutely necessary to investigate the air ingress behavior during the accident before exploring the design criteria. The present paper briefly describes major activities and results of the air ingress research in our laboratory. (author)

  4. AIR INGRESS ANALYSIS: COMPUTATIONAL FLUID DYNAMIC MODELS

    International Nuclear Information System (INIS)

    The Idaho National Laboratory (INL), under the auspices of the U.S. Department of Energy, is performing research and development that focuses on key phenomena important during potential scenarios that may occur in very high temperature reactors (VHTRs). Phenomena Identification and Ranking Studies to date have ranked an air ingress event, following on the heels of a VHTR depressurization, as important with regard to core safety. Consequently, the development of advanced air ingress-related models and verification and validation data are a very high priority. Following a loss of coolant and system depressurization incident, air will enter the core of the High Temperature Gas Cooled Reactor through the break, possibly causing oxidation of the in-the core and reflector graphite structure. Simple core and plant models indicate that, under certain circumstances, the oxidation may proceed at an elevated rate with additional heat generated from the oxidation reaction itself. Under postulated conditions of fluid flow and temperature, excessive degradation of the lower plenum graphite can lead to a loss of structural support. Excessive oxidation of core graphite can also lead to the release of fission products into the confinement, which could be detrimental to a reactor safety. Computational fluid dynamic model developed in this study will improve our understanding of this phenomenon. This paper presents two-dimensional and three-dimensional CFD results for the quantitative assessment of the air ingress phenomena. A portion of results of the density-driven stratified flow in the inlet pipe will be compared with results of the experimental results.

  5. AIR INGRESS ANALYSIS: COMPUTATIONAL FLUID DYNAMIC MODELS

    Energy Technology Data Exchange (ETDEWEB)

    Chang H. Oh; Eung S. Kim; Richard Schultz; Hans Gougar; David Petti; Hyung S. Kang

    2010-08-01

    The Idaho National Laboratory (INL), under the auspices of the U.S. Department of Energy, is performing research and development that focuses on key phenomena important during potential scenarios that may occur in very high temperature reactors (VHTRs). Phenomena Identification and Ranking Studies to date have ranked an air ingress event, following on the heels of a VHTR depressurization, as important with regard to core safety. Consequently, the development of advanced air ingress-related models and verification and validation data are a very high priority. Following a loss of coolant and system depressurization incident, air will enter the core of the High Temperature Gas Cooled Reactor through the break, possibly causing oxidation of the in-the core and reflector graphite structure. Simple core and plant models indicate that, under certain circumstances, the oxidation may proceed at an elevated rate with additional heat generated from the oxidation reaction itself. Under postulated conditions of fluid flow and temperature, excessive degradation of the lower plenum graphite can lead to a loss of structural support. Excessive oxidation of core graphite can also lead to the release of fission products into the confinement, which could be detrimental to a reactor safety. Computational fluid dynamic model developed in this study will improve our understanding of this phenomenon. This paper presents two-dimensional and three-dimensional CFD results for the quantitative assessment of the air ingress phenomena. A portion of results of the density-driven stratified flow in the inlet pipe will be compared with results of the experimental results.

  6. Information from water ingress accident on AVR

    International Nuclear Information System (INIS)

    An ingress of water occurred in the AVR reactor in May 1978. The reactor had been shut down and cooled by forced circulation; liquid water entered the primary circuit from a leak in the superheater, evaporated in passing through the core and condensed in the lower part of the primary circuit and in the ball handling region. Various fission product activities were measured in the water by the AVR scientists and a study was started to identify the sources of these activities and to derive information which could be used in the analyses of water ingress accidents in general. The first part of this study is reported in this note. The possible source terms are considered separately and estimates of their contributions are made, supported by data from previous laboratory experiments where possible. The main conclusion is that valuable information has been derived concerning the desorption of iodine, cesium and strontium from dust and primary circuit surfaces. A minimum programme of measurements and analytical work necessary to increase this information has been identified. An example of the application of the data to a particular accident to a power reactor is given to indicate how the information can affect the calculation of consequences. For the second part of the study, better estimates of the fission product concentrations in the primary circuit prior to the accident and various measurements when the reactor is operating again are required. (orig.)

  7. Simulation of Chloride Diffusion in Cracked Concrete with Different Crack Patterns

    OpenAIRE

    Xiao-Yong Wang; Li-Na Zhang

    2016-01-01

    Chloride-induced corrosion of steel rebar is one of the primary durability problems for reinforced concrete structures in marine environment. Furthermore, if the surfaces of concrete structures have cracks, additional chloride can penetrate into concrete through cracked zone. For chloride ingression into cracked concrete, former researches mainly focus on influence of crack width on chloride diffusion coefficients. Other crack characteristics, such as chloride depth, crack shape (equal-width ...

  8. Operating experience of a sodium rig following the ingress of oil

    International Nuclear Information System (INIS)

    The experience of operating the Small Water Leak Rig at Dounreay in the two years following the ingress into the sodium of silicone oil from the pump is reported. The carbon penetration into the rig pipework has been monitored and has been found to agree with a diffusion model. The predictions based on this model have enabled an operating strategy to be determined to allow continued operation of the rig. (author)

  9. Probabilistic failure modelling of reinforced concrete structures subjected to chloride penetration

    Science.gov (United States)

    Nogueira, Caio Gorla; Leonel, Edson Denner; Coda, Humberto Breves

    2012-12-01

    Structural durability is an important criterion that must be evaluated for every type of structure. Concerning reinforced concrete members, chloride diffusion process is widely used to evaluate durability, especially when these structures are constructed in aggressive atmospheres. The chloride ingress triggers the corrosion of reinforcements; therefore, by modelling this phenomenon, the corrosion process can be better evaluated as well as the structural durability. The corrosion begins when a threshold level of chloride concentration is reached at the steel bars of reinforcements. Despite the robustness of several models proposed in literature, deterministic approaches fail to predict accurately the corrosion time initiation due the inherent randomness observed in this process. In this regard, structural durability can be more realistically represented using probabilistic approaches. This paper addresses the analyses of probabilistic corrosion time initiation in reinforced concrete structures exposed to chloride penetration. The chloride penetration is modelled using the Fick's diffusion law. This law simulates the chloride diffusion process considering time-dependent effects. The probability of failure is calculated using Monte Carlo simulation and the first order reliability method, with a direct coupling approach. Some examples are considered in order to study these phenomena. Moreover, a simplified method is proposed to determine optimal values for concrete cover.

  10. Modeling moisture ingress through simplified concrete crack geometries

    DEFF Research Database (Denmark)

    Pease, Bradley Justin; Michel, Alexander; Geiker, Mette Rica; Stang, Henrik

    2011-01-01

    This paper introduces a numerical model for ingress in cracked steel fibre reinforced concrete. Details of a simplified crack are preset in the model’s geometry using the cracked hinge model (CHM). The total crack length estimated using the CHM was, based on earlier work on conventional concrete......, considered to have two parts; 1) a coalesced crack length which behaves as a free-surface for moisture ingress, and 2) an isolated microcracking length which resists ingress similarly to the bulk material. Transport model results are compared to experimental results from steel fibre reinforced concrete wedge...

  11. The effect of mixed-bed resin ingress into the Embalse PHTs

    International Nuclear Information System (INIS)

    Embalse NGS is provided four in-line autoclaves for a routine materials surveillance program. Through a cooperative program between the utility management and the Research and Development Branch of CNEA, the routine program was expanded to include Materials Tests according to the on-going R and D programs. The availability of the autoclave facilities and the joint Embalse/R and D program proved very valuable in occasion of the resin ingress into the PHTS due to the collapse of a Johnson strainer on April 9, 1988. The details of the incident have been communicated previously, and it is not the purpose of this presentation to describe the sequence of events on April 9, 1988, and following days. Rather, we present here the results of the materials surveillance program that was adopted to follow the materials behaviour and to check the possible negative impact of the resin ingress. The mixed bed resins were subjected to hydrothermal degradation under high radiation fields (the reactor went into hot shut-down state in two hours and was further cooled in a six hours' interval). Formation of ammonia, carbon dioxide, sulfate, nitrate and chloride are all possible. The long term surveillance program was carried out during the following 400 EFPD, on corrosion coupons provided by AECL and on additional samples prepared in CNEA on original materials from Embalse's PHTS. Comparisons were made of the behaviour of AECL materials ingressed in the Autoclave System in 1983, CNEA materials inserted in 1986, and additional CNEA coupons installed in 1988, after the incident

  12. The effects of surface treatments on rapid chloride permeability tests

    KAUST Repository

    Yoon, Seyoon

    2012-08-01

    Surface treatments are commonly applied to improve the chloride resistance of concrete structures exposed to saline environments. Information on chloride ingress to surface-treated concrete is mostly provided by application of the rapid chloride permeability test (RCPT); this test is short in duration and provides rapid results. This study presents a numerical formulation, based on the extended Nernst-Plank/Poisson (NPP) equation, to model the effect of the surface treatment on a sample tested by RCPT. Predictions of the model are compared to experimental measurements. The simulations show that the results from RCPT, in terms of ionic profiles and measurement of the electric field, are dependent on the effectiveness of surface treatments. During RCPT, highly effective surface treatments cause both cations and anions to flocculate at the interface between the surface treatment and the concrete, creating a local electric field. Our numerical model includes these phenomena and presents a methodology to obtain more accurate diffusivities of the surface-treated- concrete from RCPT. © 2012 Elsevier B.V. All rights reserved.

  13. Computational Fluid Dynamics Analyses on Very High Temperature Reactor Air Ingress

    International Nuclear Information System (INIS)

    A preliminary computational fluid dynamics (CFD) analysis was performed to understand density-gradient-induced stratified flow in a Very High Temperature Reactor (VHTR) air-ingress accident. Various parameters were taken into consideration, including turbulence model, core temperature, initial air mole-fraction, and flow resistance in the core. The gas turbine modular helium reactor (GT-MHR) 600 MWt was selected as the reference reactor and it was simplified to be 2-D geometry in modeling. The core and the lower plenum were assumed to be porous bodies. Following the preliminary CFD results, the analysis of the air-ingress accident has been performed by two different codes: GAMMA code (system analysis code, Oh et al. 2006) and FLUENT CFD code (Fluent 2007). Eventually, the analysis results showed that the actual onset time of natural convection (∼160 sec) would be significantly earlier than the previous predictions (∼150 hours) calculated based on the molecular diffusion air-ingress mechanism. This leads to the conclusion that the consequences of this accident will be much more serious than previously expected

  14. ISOTHERMAL AIR INGRESS VALIDATION EXPERIMENTS AT IDAHO NATIONAL LABORATORY: DESCRIPTION AND SUMMARY OF DATA

    Energy Technology Data Exchange (ETDEWEB)

    Chang H. Oh; Eung S. Kim

    2010-09-01

    Idaho National Laboratory performed air ingress experiments as part of validating computational fluid dynamics code (CFD). An isothermal stratified flow experiment was designed and set to understand stratified flow phenomena in the very high temperature gas cooled reactor (VHTR) and to provide experimental data for validating computer codes. The isothermal experiment focused on three flow characteristics unique in the VHTR air-ingress accident: stratified flow in the horizontal pipe, stratified flow expansion at the pipe and vessel junction, and stratified flow around supporting structures. Brine and sucrose were used as heavy fluids and water was used as light fluids. The density ratios were changed between 0.87 and 0.98. This experiment clearly showed that a stratified flow between heavy and light fluids is generated even for very small density differences. The code was validated by conducting blind CFD simulations and comparing the results to the experimental data. A grid sensitivity study was also performed based on the Richardson extrapolation and the grid convergence index method for modeling confidence. As a result, the calculated current speed showed very good agreement with the experimental data, indicating that the current CFD methods are suitable for predicting density gradient stratified flow phenomena in the air-ingress accident.

  15. The reactivity effects of steam ingress into the core of gas-cooled fast reactors

    International Nuclear Information System (INIS)

    Steam ingress reactivity effect is caused by steam ingress into the core of GCFRs through coolant channels from the secondary coolant system during a hypothetical accident. This reactivity effect in GCFR can be considered one of the most important safety-related physics parameters as is the sodium void reactivity effect in LMFBR. The steam ingress reactivity effects have been studied for 300 MWe and 1000 MWe GCFR designed at General Atomics in US., taking account of the influences of fuel burnup, fuel temperature and the presence of control rods. The calculations have been made basing on the exact perturbation theory in R-Z geometry together with JAERI-Fast 25 group constants set Version 2. In addition, to assess the uncertainties associated with the data and methods, some detailed investigations have been made on the influences of heterogeneous arrangement of fuel pins in a subassembly, and of differences in nuclear data and their processing methods to produce group constants. And also the measurements of the concerned reactivity effects at ZPR-9 have been analysed to understand our predicting accuracy. From this study, the following conclusions were drawn: (1) In the cold clean state at low fuel temperature with no control rods present, the steam ingress reactivity effect is most positive for 1000 MWe GCFR at BOL but is negative for 300 MWe GCFR. The positive reactivity effect increases as the steam density increases. (2) The presence of control rods in the core significantly reduces the large positive reactivity effect for 1000 MWe GCFR mentioned above. (author)

  16. A numerical and experimental study of water ingression phenomena in melt pool coolability

    International Nuclear Information System (INIS)

    During a postulated severe accident, the core can melt and the melt can fail the reactor vessel. Subsequently, the molten corium can be relocated in the containment cavity forming a melt pool. The melt pool can be flooded with water at the top for quenching it. However, the question that arises is to what extent the water can ingress in the corium melt pool to cool and quench it. To reveal that, a numerical study has been carried out using the computer code MELCOOL. The code considers the heat transfer behaviour in axial and radial directions from the molten pool to the overlaying water, crust generation and growth, thermal stresses built-in the crust, disintegration of crust into debris, natural convection heat transfer in debris and water ingression into the debris bed. To validate the computer code, experiments were conducted in a facility named as core melt coolability (COMECO). The facility consists of a test section (200 mm x 200 mm square cross-section) and with a height of 300 mm. About 14 L of melt comprising of 30% CaO + 70% B2O3 (by wt.) was poured into the test section. The melt was heated by four heaters from outside the test section to simulate the decay heat of corium. The melt was water flooded from the top, and the depth of water pool was kept constant at around 700 mm throughout the experiment. The transient temperature behaviour in the melt pool at different axial and radial locations was measured with 24 K-type thermocouples and the steam flow rate was measured using a vortex flow meter. The melt temperature measurements indicated that water could ingress only up to a certain depth into the melt pool. The MELCOOL predictions were compared with the test data for the temperature distribution inside the molten pool. The code was found to simulate the quenching behaviour and depth of water ingression quite well.

  17. CFD Analyses of Air-Ingress Accident for VHTRs

    Science.gov (United States)

    Ham, Tae Kyu

    The Very High Temperature Reactor (VHTR) is one of six proposed Generation-IV concepts for the next generation of nuclear powered plants. The VHTR is advantageous because it is able to operate at very high temperatures, thus producing highly efficient electrical generation and hydrogen production. A critical safety event of the VHTR is a loss-of-coolant accident. This accident is initiated, in its worst-case scenario, by a double-ended guillotine break of the cross vessel that connects the reactor vessel and the power conversion unit. Following the depressurization process, the air (i.e., the air and helium mixture) in the reactor cavity could enter the reactor core causing an air-ingress event. In the event of air-ingress into the reactor core, the high-temperature in-core graphite structures will chemically react with the air and could lose their structural integrity. We designed a 1/8th scaled-down test facility to develop an experimental database for studying the mechanisms involved in the air-ingress phenomenon. The current research focuses on the analysis of the air-ingress phenomenon using the computational fluid dynamics (CFD) tool ANSYS FLUENT for better understanding of the air-ingress phenomenon. The anticipated key steps in the air-ingress scenario for guillotine break of VHTR cross vessel are: 1) depressurization; 2) density-driven stratified flow; 3) local hot plenum natural circulation; 4) diffusion into the reactor core; and 5) global natural circulation. However, the OSU air-ingress test facility covers the time from depressurization to local hot plenum natural circulation. Prior to beginning the CFD simulations for the OSU air-ingress test facility, benchmark studies for the mechanisms which are related to the air-ingress accident, were performed to decide the appropriate physical models for the accident analysis. In addition, preliminary experiments were performed with a simplified 1/30th scaled down acrylic set-up to understand the air-ingress

  18. Constitutive kinematic modes and shapes during vehicle ingress/egress.

    Science.gov (United States)

    Shippen, James; May, Barbara

    2016-09-01

    A study was undertaken to investigate the kinematics of older users of passenger vehicles during ingress/egress and to seek correlations between their movement and comfort rating assigned by the subjects to the ease of vehicle ingress and egress. A principal component analysis was performed on the subjects' kinematics to identify the underlying modes of movement employed by the subjects. It was found that a small number of modes could describe the movements of all the subjects across all of the vehicles. Within the subspace defined by the modal vectors, shapes were found which correlated to the comfort rating for ease of ingress and egress which the subjects had assigned to each of the cars. Knowledge of these shapes which correspond to good and poor ingress and egress will be useful to the designers of interiors and exteriors of passenger vehicles for the older person. It is recommended that vehicle designs for the older person should attempt to avoid body positions which require excessive ankle articulation and lumbar flexion/extension during ingress and egress. PMID:27184320

  19. Computational modelling of chloride ion transport in reinforced concrete

    OpenAIRE

    Meijers, S.J.H.; Bijen, J.M.J.M.; De Borst, R.; Fraaij, A.L.A.

    2001-01-01

    Exposure to a saline environment is a major threat with respect to the durability of reinforced concrete structures. The chloride ions, which are present in seawater and de-icing salts, are able to penetrate the concrete up to the depth of the reinforcement. They can eventually trigger a pitting corrosion process. The assessment of a corrosion-free service life of concrete structures is of paramount economic interest. However, the modelling of the ingress of chloride ions is complicated due t...

  20. Experimental Investigation on Contribution of CFRP Attachment to Durability of Reinforced Concrete Structure Subjected to Chloride Attack

    Institute of Scientific and Technical Information of China (English)

    Chen Fengshan; Zhao Guofan; Pan Deqiang

    2006-01-01

    The function of externally-bonded carbon fiber reinforced polymer (CFRP) in preventing chloride from entering into concrete is verified by experiment. The results show that externally-bonded CFRP can be considered as a part of corrosion prevention system of strengthened concrete structures subjected to chloride ingress, and the contribution of CFRP should be considered in evaluation of durability of reinforced concrete structures with externally-bonded CFRP. With the effective shielding function of CFRP considered, an equation for residual lifetime prediction of concrete structures with externally-bonded CFRP is derived from Ficks dispersion law. CFRP has two functions for coastal concrete structures, including strengthening and increasing durability as part of corrosion prevention system.

  1. A role of texture in controlling oxidation and hydrogen ingress in ZR-NB pressure tubes

    International Nuclear Information System (INIS)

    A nano -scale microstructural computer model for predicting ZrO2 structure and texture development during oxidation of Zr-Nb alloy has been proposed. The model assumes that the main driving force for texture formation in oxide and growth of the oxide grains is the compression stress parallel to the oxide surface. The orientation of substrate grains also plays an important role. The oxide texture, microstructure, grain boundary character distribution and the stress development can be simulated. The substrate texture, microstructure, phase composition are the major factors determining the oxide structure. This structure controls the oxygen and hydrogen transport through oxide layer; therefore the model that predicts the oxide structure allows the simulation of the corrosion behaviour and hydrogen ingress through the oxide. The proposed model has been used to predict the Zr oxidation kinetics in air for different textures of the substrate. The result of simulation agrees with character of changes observed in oxidation experiments. Eventually, this model will be able to simulate the hydrogen ingress process and to predict hydride formation and cracking of the pressure tube. The comparison between the simulation and experimental results will he presented. (author)

  2. Phenomenology of Graphite Burning in Air Ingress Accidents of HTRs

    International Nuclear Information System (INIS)

    Air ingress with graphite burning belongs to the accident scenarios in HTRs with potentially severe consequences. This paper gives an overview of basic phenomena of graphite burning like ignition conditions and moving reaction fronts. The pioneering graphite burning experiments of Don Schweitzer are successfully reevaluated. Ignition conditions are examined, and it is underlined that burning depends not only on graphite properties but also on the heat balance in the whole graphite arrangement. In graphite-moderated reactors, ignition occurs at about 650 degree C for small air flow rates: this means that normal operation temperatures in HTRs always allow for ignition. Fuel behaviour in air ingress, as determined in the KORA facility, is discussed: up to about 1300 degree C modern TRISO fuel is stable in air, but from 1500 degree C a complete, fast destruction is observed. Exemplary calculations on massive air ingress by chimney draught performed with REACT/THERMIX are outlined. For a hot bottom reflector there is a substantial time span before fuel is attacked. Because severe air ingress in well-designed HTRs belongs to beyond design basis accidents, the knowledge is fairly good. Concerning protecting measures, a more detailed examination of thick SiC layers is proposed.

  3. Air ingress benchmarking with computational fluid dynamics analysis

    International Nuclear Information System (INIS)

    The air ingress accident is a complicated accident scenario that may limit the deployment of high-temperature gas reactors. The complexity of this accident scenario is compounded by multiple physical phenomena that are involved in the air ingress event. These include diffusion, natural circulation, and complex chemical reactions with graphite and oxygen. In an attempt to better understand the phenomenon, the FLUENT-6 computational fluid dynamics code was used to assess two air ingress experiments. The first was the Japanese series of tests performed in the early 1990s by Takeda and Hishida. These separate effects tests were conducted to understand and model a multi-component experiment in which all three processes were included with the introduction of air in a heated graphite column. MIT used the FLUENT code to benchmark these series of tests with quite good results. These tests are generically applicable to prismatic reactors and the lower reflector regions of pebble-bed reactors. The second series of tests were performed at the NACOK facility for pebble bed reactors as reported by Kuhlmann [Kuhlmann, M.B., 1999. Experiments to investigate flow transfer and graphite corrosion in case of air ingress accidents in a high-temperature reactor]. These tests were aimed at understanding natural circulation of pebble bed reactors by simulating hot and cold legs of these reactors. The FLUENT code was also successfully used to simulate these tests. The results of these benchmarks and the findings will be presented

  4. Concrete cover cracking with reinforcement corrosion of RC beam during chloride-induced corrosion process

    International Nuclear Information System (INIS)

    This paper deals with the evolution of the corrosion pattern based on two beams corroded by 14 years (beam B1CL1) and 23 years (beam B2CL1) of conservation in a chloride environment. The experimental results indicate that, at the cracking initiation stage and the first stage of cracking propagation, localized corrosion due to chloride ingress is the predominant corrosion pattern and pitting corrosion is the main factor that influences the cracking process. As corrosion cracking increases, general corrosion develops rapidly and gradually becomes predominant in the second stage of cracking propagation. A comparison between existing models and experimental results illustrates that, although Vidal et al.'s model can better predict the reinforcement corrosion of beam B1CL1 under localized corrosion, it cannot predict the corrosion of beam B2CL1 under general corrosion. Also, Rodriguez's model, derived from the general corrosion due to electrically accelerated corrosion experiments, cannot match natural chloride corrosion irrespective of whether corrosion is localized or general. Thus, for natural general corrosion in the second stage of cracking propagation, a new model based on the parameter of average steel cross-section loss is put forward to predict steel corrosion from corrosion cracking.

  5. Pressurizing Behavior on Ingress of Coolant into Pebble Bed of Blanket of Fusion DEMO Reactor

    International Nuclear Information System (INIS)

    Solid breeder blankets are being developed as candidate blankets for the Fusion DEMO reactor in Japan. JAEA is performing the development of the water cooled and helium cooled solid breeder blankets. The blanket utilizes ceramic breeder pebbles and multiplier pebbles beds cooled by high pressure water or high pressure helium in the cooling tubes placed in the blanket box structure. In the development of the blanket, it is very important to incorporate the safety technology as well as the performance improvement on tritium production and energy conversion. In the safety design and technology, coolant ingress in the blanket box structure is one of the most important events as the initiators. Especially the thermal hydraulics in the pebble bed in the case of the high pressure coolant ingress is very important to evaluate the pressure propagation and coolant flow behavior. This paper presents the preliminary results of the pressure loss characteristics by the coolant ingress in the pebble bed. Experiments have been performed by using alumina pebble bed (4 litter maximum volume of the pebble bed) and nitrogen gas to simulate the helium coolant ingress into breeder and multiplier pebble beds. Reservoir tank of 10 liter is filled with 1.0 MPa nitrogen. The nitrogen gas is released at the bottom part of the alumina pebble bed whose upper part is open to the atmosphere. The pressure change in the pebble bed is measured to identify the pressure loss. The measured values are compared with the predicted values by Ergun's equation, which is the correlation equation on pressure loss of the flow through porous medium. By the results of the experiments with no constraint on the alumina pebble bed, it was clarified that the measured value agreed in the lower flow rate. However, in the higher flow rate where the pressure loss is high, the measured value is about half of the predicted value. The differences between the measured values and the predicted values will be discussed from

  6. Effect of carbonation on the chloride diffusion of mortar specimens exposed to cyclic wetting and drying

    OpenAIRE

    Malheiro, Raphaele Lira Meireles Castro; Camões, Aires; Ferreira, Rui Miguel; Meira, Gibson; Amorim, M. T. Pessoa de

    2014-01-01

    Carbonation and chloride ingress are the two main causes of corrosion in reinforced concrete structures. Despite the combined action of these mechanisms being a reality, there is little research on the effect of carbonation on the chloride diffusion in concrete. This work intends to study the influence of carbonation on chloride diffusion of mortar specimens. Cubic mortar specimens were cast with 0.55 of water-cement ratio. After curing, the specimens were subjected to 56 days of wetting and ...

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

    Energy Technology Data Exchange (ETDEWEB)

    Leaist, D.G.

    1986-09-01

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

  8. Stochastic Modeling of Reinforced Concrete Structures Exposed to Chloride Attack

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Frier, Christian

    2003-01-01

    For many reinforced concrete structures corrosion of reinforcement is an important problem since it can result in expensive maintenance and repair actions. Further, a significant reduction of the load-bearing capacity can occur. One mode of corrosion initiation is that the chloride content around...... the reinforcement exceeds a critical threshold value. In the present paper a stochastic model is described by which the chloride content in a reinforced concrete structure can be estimated. The chloride ingress is modeled by a 2-dimensional diffusion process and the diffusion coefficient, surface...

  9. Stochastic modeling of reinforced concrete structures exposed to chloride attack

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Frier, Christian

    2004-01-01

    For many reinforced concrete structures corrosion of reinforcement is an important problem since it can result in expensive maintenance and repair actions. Further, a significant reduction of the load-bearing capacity can occur. One mode of corrosion initiation is that the chloride content around...... the reinforcement exceeds a critical threshold value. In the present paper a stochastic model is described by which the chloride content in a reinforced concrete structure can be estimated. The chloride ingress is modeled by a 2-dimensional diffusion process and the diffusion coefficient, surface...

  10. Magnitude and reactivity consequences of moisture ingress into the modular High-Temperature Gas-Cooled Reactor core

    International Nuclear Information System (INIS)

    Inadvertent admission of moisture into the primary system of a modular high-temperature gas-cooled reactor has been identified in US Department of Energy-sponsored studies as an important safety concern. The work described here develops an analytical methodology to quantify the pressure and reactivity consequences of steam-generator tube rupture and other moisture-ingress-related incidents. Important neutronic and thermohydraulic processes are coupled with reactivity feedback and safety and control system responses. The rate and magnitude of steam buildup are found to be dominated by major system features such as break size compared with safety valve capacity and reliability and less sensitive to factors such as heat transfer coefficients. The results indicate that ingress transients progress at a slower pace than previously predicted by bounding analyses, with milder power overshoots and more time for operator or automatic corrective actions

  11. Dirt Ingress Behavior of Wipers for Hydraulic Cylinders

    OpenAIRE

    Barillas, Gonzalo A.; Richter, Sören; Weber, Jürgen

    2016-01-01

    Dirt ingress in hydraulic cylinders is one of the sources that leads to pollution of hydraulic systems. There are already several test rigs to investigate external contamination mechanisms. However, until now only the behavior of the whole sealing system was analyzed. A new testing method to understand the dirt particle transport between a reciprocating motioned rod and a wiper is presented. The new approach aims to avoid known issues such as limited reproducibility and long duration. The pap...

  12. Deuterium ingress at rolled joints in Embalse nuclear power plant

    International Nuclear Information System (INIS)

    Deuterium ingress model at the Rolled Joint has been extensively used for CANDU Nuclear Power Plants Operators in the Life Management of the Pressure Tubes. The importance of understanding the model is vital to avoid delayed hydride cracking at the Rolled Joint. This work reports the first step on develop the model presented on literature to be used in Argentinean CANDU 6, Embalse Nuclear Power Plant. (author)

  13. Safety Analysis Results for Cryostat Ingress Accidents in ITER

    Science.gov (United States)

    Merrill, B. J.; Cadwallader, L. C.; Petti, D. A.

    1997-06-01

    Accidents involving the ingress of air, helium, or water into the cryostat of the International Thermonuclear Experimental Reactor (ITER) tokamak design have been analyzed with a modified version of the MELCOR code for the ITER Non-site Specific Safety Report (NSSR-1). The air ingress accident is the result of a postulated breach of the cryostat boundary into an adjoining room. MELCOR results for this accident demonstrate that the condensed air mass and increased heat loads are not a magnet safety concern, but that the partial vacuum in the adjoining room must be accommodated in the building design. The water ingress accident is the result of a postulated magnet arc that results in melting of a Primary Heat Transport System (PHTS) coolant pipe, discharging PHTS water and PHTS water activated corrosion products and HTO into the cryostat. MELCOR results for this accident demonstrate that the condensed water mass and increased heat loads are not a magnet safety concern, that the cryostat pressure remains below design limits, and that the corrosion product and HTO releases are well within the ITER release limits.

  14. Witwatersrand Water Ingress Project - Information Management System (WWIPIMS), South Africa

    Energy Technology Data Exchange (ETDEWEB)

    Hild, S.; Sieste, M.; Barth, A.; Rudinskaya, J. [Beak Consultants GmbH, Freiberg (Germany); Croukamp, L.; Roos, M. [Council for Geoscience (CGS), Pretoria (South Africa)

    2006-07-01

    The Witwatersrand Water Ingress Project at the Council for Geoscience, South Africa (CGS) deals with an inventory, a risk assessment and the development of rehabilitation strategies for abandoned mining sites in the Witwatersrand Mining Basin. The main focus is the prevention of water ingress and to understand the future decanting scenario. An Information Management System consisting of both a relational database and an application for the Witwatersrand Water Ingress Project is established for accessing and managing all project-related data. This easy to use application makes the data available to all staff at the CGS via several modules as well as a GIS-component for accessing and querying spatial data. This will enable the scientists to derive further knowledge of the water flowing processes by directly using all of the existing up-to-date data. Many additional functions, such as the support for map printing on demand, extensive possibilities for inquiries, data import and export, diagrams and a GIS-viewer for spatial inquiries do complete the system. (orig.)

  15. Simulation of Chloride Diffusion in Cracked Concrete with Different Crack Patterns

    Directory of Open Access Journals (Sweden)

    Xiao-Yong Wang

    2016-01-01

    Full Text Available Chloride-induced corrosion of steel rebar is one of the primary durability problems for reinforced concrete structures in marine environment. Furthermore, if the surfaces of concrete structures have cracks, additional chloride can penetrate into concrete through cracked zone. For chloride ingression into cracked concrete, former researches mainly focus on influence of crack width on chloride diffusion coefficients. Other crack characteristics, such as chloride depth, crack shape (equal-width crack or tapered crack, crack density, and spacing, are not studied in detail. To fill this gap, this paper presents a numerical procedure to simulate chloride ingression into cracked concrete with different crack geometry characteristics. Cracked concrete is divided into two parts, sound zone and cracked zone. For stress-free concrete, the diffusion coefficient of sound zone is approximately assumed to be the same as sound concrete, and the diffusion coefficient of cracked zone is expressed as a piecewise function of crack width. Two-dimensional finite element method is used to determine chloride concentration. It is found that, with the increasing of crack width, crack depth, and crack amount, chloride ingression will aggravate. The analysis results generally agree with experimental results.

  16. Erosion Prediction of Chloride Ions in Existing Concrete under the Natural Tidal Environment by the Natural Diffusion Method%自然扩散法预测感潮环境下混凝土氯离子侵蚀

    Institute of Scientific and Technical Information of China (English)

    张俊芝; 郑辉; 周建民; 王梁英; 刘华挺

    2011-01-01

    通过对自然感潮环境下混凝土的自由氯离子浓度分布的分析,研究了既有混凝土氯离子侵蚀的特征及扩散特性,采用室内自然扩散法进行了模拟扩散试验,并根据Fick第二定律和Monte Carlo法分析了既有混凝土和试验混凝土的扩散参数及钢筋初始锈蚀时间.结果表明:自然环境下混凝土的氯离子侵蚀存在明显的对流区,自然扩散法的氯离子扩散系数大于自然环境下2个数量级,模拟混凝土中钢筋表面的自由氯离子浓度是自然环境下实际浓度的2倍,钢筋初始锈蚀时间是实际的240倍.%Characteristics of erosion and diffusion of free chloride ions in existing concrete are studied through analysis for chloride ion concentration distribution of concrete in the natural tidal environment, a simulation experiment for chloride ion diffusion by the indoor natural diffusion method is tested, diffusion parameters and the initial corrosion time of steel bar in concrete of existing concrete and experimental concrete are analyzed on the basis of Fick's second law and the Monte Carlo method. The experimental and analysis results show that there are obvious convective region of chloride ion ingress in the natural environment, the chloride diffusion coefficient measured by the natural diffusion method is two orders of magnitude larger than that in the natural tidal environment, and free chloride ion concentration of reinforcement surface in simulated concrete is double of actual concentration of concrete in the natural tidal environment,initial time of corrosion of steel bar in experimental concrete is 240 times higher than concrete in the natural environment.

  17. Evaluation of polymeric coatings and primers against chloride ingress in concrete

    OpenAIRE

    Aguiar, J. L. Barroso de; Schueremans, Luc; Moreira, Pedro M.; Camões, Aires; Van Gemert, D.

    2007-01-01

    Nowadays, it is common knowledge that the biggest degradation of concrete is caused by outside to inside actions. Penetration of moisture, active gases and aggressive ions, as well as mechanical, physical and chemical causes frequently act together. A low porosity and low permeability of concrete to penetration of moisture and gases are the first lines of defence against several deterioration mechanisms. One of the possible ways to protect the concrete is using coatings and primers that act a...

  18. Air-ingress analysis: Part 1. Theoretical approach

    International Nuclear Information System (INIS)

    Idaho National Laboratory (INL), under the auspices of the U.S. Department of Energy (DOE), is performing research and development that focuses on key phenomena important during potential scenarios that may occur in very high temperature gas-cooled reactors (VHTRs). Phenomena identification and ranking studies to date have ranked an air-ingress event, following on the heels of a VHTR depressurization, as important with regard to core safety. Consequently, the development of advanced air-ingress-related models and verification and validation data are a very high priority. Following a loss of coolant and system depressurization incident, air will enter the core of the VHTR through the break, possibly causing oxidation of the graphite core and reflector graphite structure. Simple core and plant models indicate that, under certain circumstances, the oxidation may proceed at an elevated rate with additional heat generated from the oxidation reaction itself. Under postulated conditions of fluid flow and temperature, excessive degradation of lower plenum graphite caused by graphite oxidation can lead to a loss of mechanical strength. Excessive oxidation of core graphite can also lead to a release of fission products into the confinement, which could be detrimental to reactor safety. Analytical models developed in this study will improve our understanding of this phenomenon. This paper presents two sets of analytical models for the qualitative assessment of the air-ingress phenomena. The results from the analytical models are compared with results of the computational fluid dynamic models (CFD) in the subsequent paper. The analytical models agree well with those CFD results.

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

    International Nuclear Information System (INIS)

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

  20. Studies on air ingress for pebble bed reactors

    International Nuclear Information System (INIS)

    A loss-of-coolant accident (LOCA) has been considered a critical event for helium-cooled pebbled bed reactors. Following helium depressurization, it is anticipated that unless countermeasures are taken air will enter the core through the break and then by molecular diffusion and ultimately by natural convection leading to oxidation of the in-core graphite structure and graphite pebbles. Thus, without any mitigating features a LOCA will lead to an air ingress event. The INEEL is studying such an event with two well-respected light water reactor transient response codes: RELAP5/ATHENA and MELCOR. To study the degree of graphite oxidation occurring due to an air ingress event, a MELCOR model of a reference pebble bed design was constructed. A modified version of MELCOR developed at INEEL, which includes graphite oxidation capabilities, and molecular diffusion of air into helium was used for these calculations. Results show that the lower reflector graphite consumes all of the oxygen before reaching the core. The results also show a long time delay between the time that the depressurization phase of the accident is over and the time that natural circulation air through the core occurs. (author)

  1. Interactions between chloride and cement-paste materials.

    Science.gov (United States)

    Barberon, Fabien; Baroghel-Bouny, Véronique; Zanni, Hélène; Bresson, Bruno; d'Espinose de la Caillerie, Jean-Baptiste; Malosse, Lucie; Gan, Zehong

    2005-02-01

    The durability of cement-based materials with respect to exterior aggressions is one of the current priorities in civil engineering. Depending on their use, the cement-based materials can be exposed to different types of aggressive environments. For instance, damages to concrete structures in contact with a saline environment (sea water on bridges, deicing salts on roads, etc.) are of utmost importance. Upon exposure to saline water, Cl- ions penetrate into the structures and subsequently lead to reinforcement corrosion. Chloride attack is often combined with other aggressive influences such as temperature (e.g., freezing) or the ingress of other ions (e.g., sulfates in sea water). We therefore aim to explore the effect of sodium chloride (NaCl) on the structural chemistry of cement paste. Existing studies about reinforcement corrosion by chloride have focused on the penetration of Cl- ions and the comparison between "free" ions (water-soluble ions) and bound ones. However, little is known about the fixation mechanisms, the localization of Cl in the cement matrix and the structural interaction between Cl and the silicate and aluminate hydrate phases present in cement paste. We present here results of a multinuclear nuclear magnetic resonance study on the fixation of chloride in the hydration products and the characterization of new phases potentially appearing due to chloride ingress. PMID:15833625

  2. Testing the hydrological landscape unit classification system and other terrain analysis measures for predicting low-flow nitrate and chloride in watersheds.

    Science.gov (United States)

    Poor, Cara J; McDonnell, Jeffrey J; Bolte, John

    2008-11-01

    Elevated nitrate concentrations in streamwater are a major environmental management problem. While land use exerts a large control on stream nitrate, hydrology often plays an equally important role. To date, predictions of low-flow nitrate in ungauged watersheds have been poor because of the difficulty in describing the uniqueness of watershed hydrology over large areas. Clearly, hydrologic response varies depending on the states and stocks of water, flow pathways, and residence times. How to capture the dominant hydrological controls that combine with land use to define streamwater nitrate concentration is a major research challenge. This paper tests the new Hydrologic Landscape Regions (HLRs) watershed classification scheme of Wolock and others (Environmental Management 34:S71-S88, 2004) to address the question: Can HLRs be used as a way to predict low-flow nitrate? We also test a number of other indexes including inverse-distance weighting of land use and the well-known topographic index (TI) to address the question: How do other terrain and land use measures compare to HLR in terms of their ability to predict low-flow nitrate concentration? We test this for 76 watersheds in western Oregon using the U.S. Environmental Protection Agency's Environmental Monitoring and Assessment Program and Regional Environmental Monitoring and Assessment Program data. We found that HLRs did not significantly improve nitrate predictions beyond the standard TI and land-use metrics. Using TI and inverse-distance weighting did not improve nitrate predictions; the best models were the percentage land use-elevation models. We did, however, see an improvement of chloride predictions using HLRs, TI, and inverse-distance weighting; adding HLRs and TI significantly improved model predictions and the best models used inverse-distance weighting and elevation. One interesting result of this study is elevation consistently predicted nitrate better than TI or the hydrologic classification

  3. Ingress of water into solid nylon 6.6

    Science.gov (United States)

    Mansfield, P.; Bowtell, R.; Blackband, S.

    The ingress of water into Nylon 6.6 has been studied over a range of temperatures by nuclear magnetic resonance imaging techniques. The results have been used to extract the translational diffusion coefficient as a function of water concentration for various temperatures. These results in turn allow the activation energies to be evaluated. Other experiments have been made to measure the spin relaxation times T1 and T2. The results are interpreted using a two-phase exchange model from which good agreement for both the diffusion and relaxation-time data is obtained. High-pressure diffusion results also presented support the view that water is taken up preferentially at the amorphous amide sites in the Nylon and that pressure increases serve to force water onto sitccupied sites and/or onto occupied sites, giving up to three waters per amide site.

  4. Moisture ingress into electronics enclosures under isothermal conditions

    Science.gov (United States)

    Staliulionis, Ž.; Jabbari, M.; Hattel, J. H.

    2016-06-01

    The number of electronics used in outdoor environment is constantly growing. The humidity causes about 19 % of all electronics failures and, especially, moisture increases these problems due to the ongoing process of miniaturization and lower power consumption of electronic components. Moisture loads are still not understood well by design engineers, therefore this field has become one of the bottlenecks in the electronics system design. The objective of this paper is to model moisture ingress into an electronics enclosure under isothermal conditions. The moisture diffusion model is based on a 1D quasi-steady state (QSS) approximation for Fick's second law. This QSS approach is also described with an electrical analogy which gives a fast tool in modelling of the moisture response. The same QSS method is applied to ambient water vapour variations. The obtained results are compared to an analytical solution and very good agreement is found.

  5. Progress in air ingress simulation with ATHLET-CD

    International Nuclear Information System (INIS)

    To ensure the coolability of an overheated core, reflood of the uncovered fuel elements is an essential accident management measure to terminate a severe accident transient in Light Water Reactors (LWR) and therefore to avoid further core degradation. From analysis of the TMI-2 accident it is known that an enhanced oxidation of the Zircaloy cladding may occur before the water succeeds in cooling the fuel rods. This oxidation process results in a sharp temperature increase, hydrogen generation and can finally after fuel rod cladding failure lead to fission product release. For further development and validation of the program ATHLET-CD (Analysis of Thermal-hydraulics of Leaks and Transients - Core Degradation), post-test calculations of experiments creating a reflood scenario in a controlled and defined environment are used. One of these experiments is QUNECH-16 in which air is injected into the bundle region to simulate air ingress. Through the oxidation in air atmosphere the core degradation continues and speeds up due to the more exothermic reactions. In this work, the QUENCH-16 experiment and its conduct will be presented followed by explanations of the modelling in ATHLET-CD version 2.2A, and version 2.2C respectively. The main difference is the ability of version 2.2C to consider nitride formation under oxygen starved conditions during the oxidation process. Results of both ATHLET-CD versions simulating the test will be discussed in order to validate the code's ability to adequately calculate phenomena like hydrogen production and oxidation behaviour during an air ingress scenario. (orig.)

  6. Progress in air ingress simulation with ATHLET-CD

    Energy Technology Data Exchange (ETDEWEB)

    Bratfisch, Christian; Hoffmann, Mathias; Koch, Marco K. [Bochum Univ. (Germany). Reactor Simulation and Safety Group

    2013-07-01

    To ensure the coolability of an overheated core, reflood of the uncovered fuel elements is an essential accident management measure to terminate a severe accident transient in Light Water Reactors (LWR) and therefore to avoid further core degradation. From analysis of the TMI-2 accident it is known that an enhanced oxidation of the Zircaloy cladding may occur before the water succeeds in cooling the fuel rods. This oxidation process results in a sharp temperature increase, hydrogen generation and can finally after fuel rod cladding failure lead to fission product release. For further development and validation of the program ATHLET-CD (Analysis of Thermal-hydraulics of Leaks and Transients - Core Degradation), post-test calculations of experiments creating a reflood scenario in a controlled and defined environment are used. One of these experiments is QUNECH-16 in which air is injected into the bundle region to simulate air ingress. Through the oxidation in air atmosphere the core degradation continues and speeds up due to the more exothermic reactions. In this work, the QUENCH-16 experiment and its conduct will be presented followed by explanations of the modelling in ATHLET-CD version 2.2A, and version 2.2C respectively. The main difference is the ability of version 2.2C to consider nitride formation under oxygen starved conditions during the oxidation process. Results of both ATHLET-CD versions simulating the test will be discussed in order to validate the code's ability to adequately calculate phenomena like hydrogen production and oxidation behaviour during an air ingress scenario. (orig.)

  7. Analysis on the Density Driven Air-Ingress Accident in VHTRs

    International Nuclear Information System (INIS)

    Air-ingress following the pipe rupture is considered to be the most serious accident in the VHTRs due to its potential problems such as core heat-up, structural integrity and toxic gas release. Previously, it has been believed that the main air-ingress mechanism of this accident is the molecular diffusion process between the reactor core and the cavity. However, according to some recent studies, there is another fast air-ingress process that has not been considered before. It is called density-driven stratified flow. The potential for density-driven stratified air ingress into the VHTR following a large-break LOCA was first described in the NGNP Methods Technical Program based on stratified flow studies performed with liquid. Studies on densitygradient driven stratified flow in advanced reactor systems has been the subject of active research for well over a decade since density-gradient dominated stratified flow is an inherent characteristic of passive systems used in advanced reactors. Recently, Oh et al. performed a CFD analysis on the stratified flow in the VHTR, and showed that this effect can significantly accelerate the air-ingress process in the VHTRs. They also proposed to replace the original air-ingress scenario based on the molecular diffusion with the one based on the stratified flow. This paper is focusing on the effect of stratified flow on the results of the air-ingress accident in VHTR

  8. Simulation of the air ingress experiment parameter SF4 using ATHLET-CD

    International Nuclear Information System (INIS)

    The air ingress test PARAMETER SF4 was performed in July 2009 with the aim to investigate the behavior of a VVER bundle during reflooding after air ingress. Simulations are performed using the severe accident code ATHLET-CD. The results of the simulations show a good agreement in comparison to the experimental data during the pre-oxidation phase and in most bundle regions also during air ingress. The hydrogen generation is very close to the experimental data up to the beginning of quenching; afterwards the total amount of H2 is underpredicted. Further improvement can be achieved by using a model to consider ZrN formation. (author)

  9. Response of fuel, fuel elements and gas cooled reactor cores under accidental air or water ingress conditions. Proceedings of a technical committee meeting held in Beijing, China, 25-27 October 1993

    International Nuclear Information System (INIS)

    The meeting was convened by the IAEA on the recommendation of the IAEA's International Working Group on Gas Cooled Reactors. It was attended by participants from China, France, Germany, Japan, Netherlands, Switzerland, the Russian Federation, the United Kingdom and the United States of America. The meeting covered the following topics: experimental investigations of the effects of air and water ingress; predicted response of fuel, graphite and other reactor components; options for minimizing or mitigating the effects of air or water ingress. 19 papers were presented at the meeting. A separate abstract was prepared for each of these papers. Refs, figs and tabs

  10. A new engineering approach to predict the long-term hydrostatic strength of unplasticized poly(vinyl chloride) pipes

    OpenAIRE

    Visser, H.A.; Wolters, M.; Bor, T.C.; Engels, T.A.P.; Govaert, L. E.

    2008-01-01

    Extruded polymer pipes are qualified using pressurized pipe tests. With these tests the long-term hydrostatic strength is determined by subjecting the pipes to an internal pressure, while measuring the time-to-failure. Although these tests can be accelerated (at higher temperatures), they remain time consuming and require a spacious experimental setup. To circumvent this costly method a model based approach is proposed by which the long-term hydrostatic strength is predicted. Using short term...

  11. Theoretical and experimental studies of crossflow minichannel heat exchanger subjected to external heat ingress

    International Nuclear Information System (INIS)

    The effect of heat in-leak, an unavoidable phenomenon occurring due to the temperature difference between the system and its surroundings, has been studied for two-stream crossflow minichannel heat exchangers with unmixed fluids. Assuming that the amount of heat in-leak is known, an analytical expression for the normalised temperature difference between hot and cold fluids has been derived in terms of dimensionless parameters. The analytical results, in conjugation with the area partitioning of crossflow heat exchanger both in x and y directions, have been used for predicting the outlet fluid temperatures. On the experimental part, one of the end plates in a crossflow-type multistream, minichannel heat exchanger has been subjected to deliberate external heat input given electrically. The variation in the exit fluid temperatures has been recorded as a function of this external heat in-leak entering the exchanger through one of its outer surfaces. Experimental data obtained is employed to validate the fluid exit temperatures predicted by the developed model under the same conditions of external heat ingress. - Highlights: • Theoretical model of crossflow heat exchanger with known ambient heat leak amount. • Numerical technique of partitioning exchanger into smaller segments. • Experimental validation of model by testing of crossflow minichannel heat exchanger

  12. Simulation of Water Vapor Ingress into PV-Modules under Different Climatic Conditions

    Directory of Open Access Journals (Sweden)

    Philip Hülsmann

    2013-01-01

    Full Text Available This work deals with the simulation of water vapor ingress into wafer-based PV-modules for long-term exposure under different climatic conditions. Measured material parameters together with climatic data sets from four test sites (tropic, moderate, alpine, and arid were used to calculate the water concentration inside of the encapsulant between solar cell and glass for a lifetime of 20 years. Two back-sheet materials (PET-based and PA-based combined with EVA as encapsulant were used in respect to their influence on water ingress. The results show faster water ingress for warmer regions, but the highest concentrations were found for the moderate test site. The water ingress was additionally influenced by the used encapsulant and back-sheet combination. In particular the temperature dependency of the mass transfer, which differs from material to material, was the focus of this investigation.

  13. Nde for Water Ingression in Composite Radomes on Aircraft

    Science.gov (United States)

    Hsu, David K.; Barnard, Daniel J.; Kite, Adam H.; Kim, Ki-Bok

    2008-02-01

    Aircraft radomes, being an electronic window for the radar, are made of nonconducting composite sandwiches with glass or silica fiber-reinforced facesheet and Nomex honeycomb or foam core. Trapped water or moisture can produce shadow on the image and severely degrade the performance of the radar. To detect water ingression in radomes, the available NDE techniques include x-ray radiography, infrared thermography, and a radome moisture meter that measures the RF power loss caused by the presence of water. In this work we explore the utility of commercially available capacitive sensors with co-planar electrodes that measure the change of the dielectric constant in the fringing field. These capacitive sensors, such as the electronic stud finder and moisture meters for wood, can exploit the large dielectric constant of water and serve as one-sided detectors for water and moisture in radomes. The sensitivities of the various moisture meters were compared in the experimental detection of water introduced into radome panels and water and moisture trapped in retired radomes.

  14. Investigation of tritium activity ingress to pressure suppression pool

    International Nuclear Information System (INIS)

    Kakrapar Atomic Power Station is a standardised design Indian PHWR consisting of twin units of 220 MWe each. Pressure suppression pool situated at the basement of reactor building holds about 2200 m3 of DM water. It acts as a media separating the high enthalpy areas from low enthalpy areas and remain passive during normal operation. During LOCA it reduces the pressure in RB atmosphere by condensing the steam passing through it. In both units of KAPS tritium activity is observed in suppression pool, most predominantly in KAPS-1. Activity build up in suppression pool can act as potential source of tritium activity in RB atmosphere leading to increased internal exposure of occupational workers. Also during de-watering of suppression pool, this water adds to the amount of liquid waste generated from the station which eventually results in exposure of the public to tritium. This paper discusses the activity build up trend in KAPS-1 suppression pool, its sources, works done to prevent the activity ingress and suggestions for design improvement. (author)

  15. Validations of CFD Code for Density-Gradient Driven Air Ingress Stratified Flow

    International Nuclear Information System (INIS)

    Air ingress into a very high temperature gas-cooled reactor (VHTR) is an important phenomena to consider because the air oxidizes the reactor core and lower plenum where the graphite structure supports the core region in the gas turbine modular helium reactor (GTMHR) design, thus jeopardizing the reactor's safety. Validating the computational fluid dynamics (CFD) code used to analyze the air ingress phenomena is therefore an essential part of the safety analysis and the ultimate computation required for licensing.

  16. Predictive model for the reduction of heat resistance of Listeria monocytogenes in ground beef by the combined effect of sodium chloride and apple polyphenols.

    Science.gov (United States)

    Juneja, Vijay K; Altuntaş, Evrim Güneş; Ayhan, Kamuran; Hwang, Cheng-An; Sheen, Shiowshuh; Friedman, Mendel

    2013-06-01

    We investigated the combined effect of three internal temperatures (57.5, 60, and 62.5°C) and different concentrations (0 to 3.0 wt/wt.%) of sodium chloride (NaCl) and apple polyphenols (APP), individually and in combination, on the heat-resistance of a five-strain cocktail of Listeria monocytogenes in ground beef. A complete factorial design (3×4×4) was used to assess the effects and interactions of heating temperature, NaCl, and APP. All 48 combinations were tested twice, to yield 96 survival curves. Mathematical models were then used to quantitate the combined effect of these parameters on heat resistance of the pathogen. The theoretical analysis shows that compared with heat alone, the addition of NaCl enhanced and that of APP reduced the heat resistance of L. monocytogenes measured as D-values. By contrast, the protective effect of NaCl against thermal inactivation of the pathogen was reduced when both additives were present in combination, as evidenced by reduction of up to ~68% in D-values at 57.5°C; 65% at 60°C; and 25% at 62.5°C. The observed high antimicrobial activity of the combination of APP and low salt levels (e.g., 2.5% APP and 0.5% salt) suggests that commercial and home processors of meat could reduce the salt concentration by adding APP to the ground meat. The influence of the combined effect allows a reduction of the temperature of heat treatments as well as the salt content of the meat. Meat processors can use the predictive model to design processing times and temperatures that can protect against adverse effects of contaminated meat products. Additional benefits include reduced energy use in cooking, and the addition of antioxidative apple polyphenols may provide beneficial health affects to consumers. PMID:23587714

  17. Impact of storage position on oxygen ingress through different closures into wine bottles.

    Science.gov (United States)

    Lopes, Paulo; Saucier, Cédric; Teissedre, Pierre-Louis; Glories, Yves

    2006-09-01

    Wine bottle aging is extremely dependent on the oxygen barrier properties of closures. Kinetics of oxygen ingress through different closures into bottles was measured by a nondestructive colorimetric method from 0.25 to 2.5 mL of oxygen. After 12, 24, and 36 months of storage, only the control (glass bottle ampule) was airtight. Other closures displayed different oxygen ingress rates, which were clearly influenced by the closure type and were independent of bottle storage position (upright, laid down) for most of the closures tested, at least during the first 24 months of the experiment under controlled conditions. The oxygen ingress rates into bottles were lowest in screw caps and "technical" corks, intermediate in conventional natural cork stoppers, and highest in the synthetic closures. PMID:16939334

  18. Autonomous Landing and Ingress of Micro-Air-Vehicles in Urban Environments Based on Monocular Vision

    Science.gov (United States)

    Brockers, Roland; Bouffard, Patrick; Ma, Jeremy; Matthies, Larry; Tomlin, Claire

    2011-01-01

    Unmanned micro air vehicles (MAVs) will play an important role in future reconnaissance and search and rescue applications. In order to conduct persistent surveillance and to conserve energy, MAVs need the ability to land, and they need the ability to enter (ingress) buildings and other structures to conduct reconnaissance. To be safe and practical under a wide range of environmental conditions, landing and ingress maneuvers must be autonomous, using real-time, onboard sensor feedback. To address these key behaviors, we present a novel method for vision-based autonomous MAV landing and ingress using a single camera for two urban scenarios: landing on an elevated surface, representative of a rooftop, and ingress through a rectangular opening, representative of a door or window. Real-world scenarios will not include special navigation markers, so we rely on tracking arbitrary scene features; however, we do currently exploit planarity of the scene. Our vision system uses a planar homography decomposition to detect navigation targets and to produce approach waypoints as inputs to the vehicle control algorithm. Scene perception, planning, and control run onboard in real-time; at present we obtain aircraft position knowledge from an external motion capture system, but we expect to replace this in the near future with a fully self-contained, onboard, vision-aided state estimation algorithm. We demonstrate autonomous vision-based landing and ingress target detection with two different quadrotor MAV platforms. To our knowledge, this is the first demonstration of onboard, vision-based autonomous landing and ingress algorithms that do not use special purpose scene markers to identify the destination.

  19. Experiment on Density Gradient Driven Flow in Small Break Air Ingress Accident of VHTRs

    International Nuclear Information System (INIS)

    This study measures amount of air-ingress rates through a small hole in a circular pipe for various break conditions. The main parameters considered are break orientation, break size, main flow velocity, and density ratio. The main objectives are summarized below: □ Understanding on fundamental air-ingress phenomena in the small break accident □ Development of flow regime map for the small break air-ingress □ Development of air-ingress model for VHTR safety analysis code. A Very High Temperature Reactor (VHTR) is one of the six Gen-IV reactor concepts which is adapting carbon layered TRISO-fuel, graphite-moderator, and helium-coolant. In spite of its inherent safety concept, the VHTR could be detrimental if a LOCA type accident occurs, which is followed by a pipe break. After the break, the air in the cavity starts to ingress into the reactor by either local density-gradient driven flow or molecular diffusion. The main concern of this accident is that it could eventually lead to structural degradation or release of the toxic and explosive gasses (CO) by oxidation of graphite. Previously, majority of the air-ingress studies have been focused on the large size break accident, which is called a double-ended-guillotine-break (DEGB). However, in this study, more focus in put on the small break (or leakage) accident, which is more realistic and probable in the VHTRs. According to the previous studies, the phenomena in the small break accident appear to be much more complicated than those in the DEGB, but little studies have been conducted and reported so far

  20. Assessment of Water Ingress Accidents in a Modular High-Temperature Gas-Cooled Reactor

    OpenAIRE

    Zhang, Z.; Dong, Y.; Scherer, W.

    2005-01-01

    Severe water ingress accidents in the 200-MW HTR-module were assessed to determine the safety margins of modular pebble-bed high-temperature gas-cooled reactors (HTR-module). The 200-MW HTR-module was designed by Siemens under the criteria that no active safety protection systems were necessary because of its inherent safe nature. For simulating the behavior of the HTR-module during severe water ingress accidents, a water, steam, and helium multiphase cavity model was developed and implemente...

  1. STUDY ON AIR INGRESS MITIGATION METHODS IN THE VERY HIGH TEMPERATURE GAS COOLED REACTOR (VHTR)

    Energy Technology Data Exchange (ETDEWEB)

    Chang H. Oh

    2011-03-01

    An air-ingress accident followed by a pipe break is considered as a critical event for a very high temperature gas-cooled reactor (VHTR). Following helium depressurization, it is anticipated that unless countermeasures are taken, air will enter the core through the break leading to oxidation of the in-core graphite structure. Thus, without mitigation features, this accident might lead to severe exothermic chemical reactions of graphite and oxygen. Under extreme circumstances, a loss of core structural integrity may occur along with excessive release of radiological inventory. Idaho National Laboratory under the auspices of the U.S. Department of Energy is performing research and development (R&D) that focuses on key phenomena important during challenging scenarios that may occur in the VHTR. Phenomena Identification and Ranking Table (PIRT) studies to date have identified the air ingress event, following on the heels of a VHTR depressurization, as very important (Oh et al. 2006, Schultz et al. 2006). Consequently, the development of advanced air ingress-related models and verification and validation (V&V) requirements are part of the experimental validation plan. This paper discusses about various air-ingress mitigation concepts applicable for the VHTRs. The study begins with identifying important factors (or phenomena) associated with the air-ingress accident by using a root-cause analysis. By preventing main causes of the important events identified in the root-cause diagram, the basic air-ingress mitigation ideas can be conceptually derived. The main concepts include (1) preventing structural degradation of graphite supporters; (2) preventing local stress concentration in the supporter; (3) preventing graphite oxidation; (4) preventing air ingress; (5) preventing density gradient driven flow; (4) preventing fluid density gradient; (5) preventing fluid temperature gradient; (6) preventing high temperature. Based on the basic concepts listed above, various air-ingress

  2. Estimation of graphite density and mechanical strength variation of VHTR during air-ingress accident

    International Nuclear Information System (INIS)

    An air-ingress accident in a Very High Temperature Gas-Cooled Reactor (VHTR) is anticipated to cause severe changes to graphite density and mechanical strength by an oxidation process that has many side effects. However, quantitative estimations have not yet been performed. This study focuses on predicting the changes in graphite density and mechanical strength via thermal hydraulic system analysis code. In order to analyze the change in graphite density, a simple graphite burn-off model was developed. The model is based on the similarities between a parallel electrical circuit and graphite oxidation. It was used to determine overall changes in the graphite's geometry and density. The model was validated by comparing its results to experimental data that was obtained for several temperatures. In the experiment, cylindrically shaped graphite specimens were oxidized in an electrical furnace and the variations of its mass were measured against time. The experiment's range covered temperatures between 6000 C and 9000 C. Experimental data validated the model's accuracy. Finally, the developed model along with other comprehensive graphite oxidation models was integrated into the VHTR system analysis code, GAMMA. GT-MHR 600 MWt reactor was selected as a reference reactor. Based on the calculation, the main oxidation process was observed 5.5 days after the accident when followed by natural convection. The core maximum temperature reached 16000 C, but never exceeded the maximum temperature criteria, 18000 C. However, the oxidation process did significantly decrease the density of bottom reflector, making it vulnerable to mechanical stress. The stress on the bottom reflector is greatly increased because it sustains the reactor core. The calculation proceeded until 11 days after the accident, resulting in an observed 4.5% decrease in density and a 25% reduction of mechanical strength

  3. Durability assessment and service life prediction model for concrete structure exposed to chloride environment%氯离子侵蚀环境下混凝土结构耐久性评估与寿命预测模型

    Institute of Scientific and Technical Information of China (English)

    王睿; 王信刚

    2013-01-01

    In marine or deicing agent environment,chloride penetration into concretes is the main cause of the reinforcement corrosion.The mechanism of the above problem was analyzed in this paper.Some durability assessments and service life prediction models for the concrete structure exposed to chloride environment were presented as well,especially the service life prediction models based on Fick's second law of diffusion.Finally,the service life of concrete structure exposed to chloride environment was analyzed according to an actual underground engineering.%在海洋或除冰盐的环境中,氯离子侵蚀是造成钢筋锈蚀的主要原因.主要分析了钢筋混凝土中氯离子侵蚀引发钢筋锈蚀的机理,介绍了氯离子侵蚀环境下混凝土结构耐久性评估与寿命预测模型,其中详细阐述了基于Fick第二扩散定律的寿命预测模型,并对氯离子侵蚀环境下混凝土的使用寿命进行了实例分析.

  4. Experimental Validation of Stratified Flow Phenomena, Graphite Oxidation, and Mitigation Strategies of Air Ingress Accidents

    Energy Technology Data Exchange (ETDEWEB)

    Chang Ho Oh; Eung Soo Kim; Hee Cheon No; Nam Zin Cho

    2008-12-01

    The US Department of Energy is performing research and development (R&D) that focuses on key phenomena that are important during challenging scenarios that may occur in the Next Generation Nuclear Plant (NGNP) Program / GEN-IV Very High Temperature Reactor (VHTR). Phenomena identification and ranking studies (PIRT) to date have identified the air ingress event, following on the heels of a VHTR depressurization, as very important (Schultz et al., 2006). Consequently, the development of advanced air ingress-related models and verification and validation (V&V) are very high priority for the NGNP program. Following a loss of coolant and system depressurization, air will enter the core through the break. Air ingress leads to oxidation of the in-core graphite structure and fuel. The oxidation will accelerate heat-up of the bottom reflector and the reactor core and will cause the release of fission products eventually. The potential collapse of the bottom reflector because of burn-off and the release of CO lead to serious safety problems. For estimation of the proper safety margin we need experimental data and tools, including accurate multi-dimensional thermal-hydraulic and reactor physics models, a burn-off model, and a fracture model. We also need to develop effective strategies to mitigate the effects of oxidation. The results from this research will provide crucial inputs to the INL NGNP/VHTR Methods R&D project. This project is focused on (a) analytical and experimental study of air ingress caused by density-driven, stratified, countercurrent flow, (b) advanced graphite oxidation experiments, (c) experimental study of burn-off in the bottom reflector, (d) structural tests of the burnt-off bottom reflector, (e) implementation of advanced models developed during the previous tasks into the GAMMA code, (f) full air ingress and oxidation mitigation analyses, (g) development of core neutronic models, (h) coupling of the core neutronic and thermal hydraulic models, and (i

  5. Service Life Assessment of Harbor Structures - Case studies of chloride ingress into concrete and sheet piling corrosion rates

    OpenAIRE

    Wall, Henrik

    2013-01-01

    The two most used building materials in harbor structures are undoubtedly steel and concrete. These two materials are often combined in the structures of wharfs and quays where the steel sheet pile walls often have cap beams of reinforced concrete. The degradation processes of these structures must be taken into account both when designing new structures and when inspecting existing harbor structures with the purpose of determining their remaining service life. Since the environmental loads o...

  6. The oxidation effects of nuclear graphite during air-ingress accidents in HTGR

    International Nuclear Information System (INIS)

    This study consists of two main parts. The first part presents an experimental investigation of two types of nuclear graphite (IG-110, IG-430) at temperatures ranging from 700 to 1000 °C. Mercury porosimetry results and the quantification of pores in SEM/OM image show that the pores (pore diameter >4 μm) tended to grow into larger pores at temperatures >700 °C. The second part of this study presents a simulation of air-ingress accident. This experiment was conducted at temperatures ranging from 800 to 1000 °C with a flow rate of 0.35 L/min to simulate an air-ingress accident. Results indicate that IG-430 showed a tremendous improvement over IG-110 at medium temperature (<800 °C). However, the advantages of IG-430 began to diminish when the temperature increased

  7. Evaluation of ATP measurements to detect microbial ingress by wastewater and surface water in drinking water

    DEFF Research Database (Denmark)

    Vang, Óluva Karin; Corfitzen, Charlotte B.; Smith, Christian;

    2014-01-01

    Fast and reliable methods are required for monitoring of microbial drinking water quality in order to protect public health. Adenosine triphosphate (ATP) was investigated as a potential real-time parameter for detecting microbial ingress in drinking water contaminated with wastewater or surface...... water. To investigate the ability of the ATP assay in detecting different contamination types, the contaminant was diluted with non-chlorinated drinking water. Wastewater, diluted at 10(4) in drinking water, was detected with the ATP assay, as well as 10(2) to 10(3) times diluted surface water....... To improve the performance of the ATP assay in detecting microbial ingress in drinking water, different approaches were investigated, i.e. quantifying microbial ATP or applying reagents of different sensitivities to reduce measurement variations; however, none of these approaches contributed significantly...

  8. Vision-Aided Autonomous Landing and Ingress of Micro Aerial Vehicles

    Science.gov (United States)

    Brockers, Roland; Ma, Jeremy C.; Matthies, Larry H.; Bouffard, Patrick

    2012-01-01

    Micro aerial vehicles have limited sensor suites and computational power. For reconnaissance tasks and to conserve energy, these systems need the ability to autonomously land at vantage points or enter buildings (ingress). But for autonomous navigation, information is needed to identify and guide the vehicle to the target. Vision algorithms can provide egomotion estimation and target detection using input from cameras that are easy to include in miniature systems.

  9. Investigation of sodium-mineral oil interaction in the experiments, modeling oil ingress phenomena on PFR

    International Nuclear Information System (INIS)

    This report contains a brief description of the experimental investigations made in June 1991 at the sodium installation of IPPE, Obninsk, with regard to the conditions of the proposed scenarios of oil ingress into PFR primary circuit. In particular, the report presents experimental results of investigations of PFR S/A inlet filter behaviour after oil injection into the sodium circuit at different conditions and relevant aspects of the oil-sodium system evolution. (author)

  10. Feasibility study on naturally safe HTGR (NSHTR) for air ingress accident

    International Nuclear Information System (INIS)

    A new design activity for an advanced reactor, referred to as a naturally safe high temperature gas-cooled reactor (NSHTR), has been launched by authors after the accident at the Fukushima Daiichi Nuclear Power Station. The concept of NSHTR is that the release of radioactive materials is kept at very low level and no harmful effect on people and the environment is ensured by only physical phenomena even in the absence of engineered safety features. At an air ingress accident, possible physical events that lead to the loss or degradation of the confinement function of the fuel-coating layers are the crack of the coatings caused by the explosion of carbon monoxide (CO) produced by the graphite oxidation and failure of the coatings by melting or sublimation caused by core heat up due to the reaction heat of the graphite oxidation. In this study, the CO concentration and the heat generated by graphite oxidation inside the circular tube were evaluated parametrically using a steady-state one-dimensional model to confirm the feasibility of NSHTR at a severe condition of the air ingress accident (i.e., a massive air ingress by simultaneous rupture of two primary pipes). It was confirmed that the CO concentration at the outlet of coolant channel can be maintained below the explosion limit due to the reaction with oxygen in the air, and the reaction heat can be removed with the decay heat by physical phenomena under certain conditions of the coolant channel geometry without any engineered safety features. The results revealed that the design of NSHTR is technically feasible in terms of the suppression of the CO explosion and the heat removal of the reaction heat at the air ingress accident

  11. Quantitative NMR monitoring of liquid ingress into repellent heterogeneous layered fabrics

    OpenAIRE

    Bencsik, Martin; Adriaensen, Hans; Brewer, Stuart; McHale, Glen

    2008-01-01

    Fabrics which are water repellent and repellent to other liquids are often constructed using multiple layers of material. Such a construction is preferable to a single layer of a liquid-repellent textile because, under the action of an applied pressure, ingress of a liquid through the first layer can be halted by the second or subsequent layers. In the quantitative investigation of this problem, current techniques provide limited information on the progress and distribution of the liquid as i...

  12. Quantitative NMR monitoring of liquid ingress into repellent heterogeneous layered fabrics

    Science.gov (United States)

    Bencsik, Martin; Adriaensen, Hans; Brewer, Stuart A.; McHale, Glen

    2008-07-01

    Fabrics which are water repellent and repellent to other liquids are often constructed using multiple layers of material. Such a construction is preferable to a single layer of a liquid-repellent textile because, under the action of an applied pressure, ingress of a liquid through the first layer can be halted by the second or subsequent layers. In the quantitative investigation of this problem, current techniques provide limited information on the progress and distribution of the liquid as it ingresses into a fabric. Moreover, many techniques require that the material is delaminated prior to analysis, and cannot be conducted in real time to measure the progress of a liquid through the textile substrate. In this work we demonstrate that unilateral NMR, which allows signal to be collected from a volume of interest in a material residing above the instrument, can be a powerful tool to quantitatively monitor the ingress of a liquid through a layered sample exhibiting pronounced heterogeneities in repellency. A known volume of oil was placed on the top of a model textile sample composed of three 80 μm thick layers. Spatially resolved one dimensional vertical NMR profiles of the system were acquired as a function of the pressure vertically applied to the top of the sample. These profiles show that the absolute liquid volume present in each layer of textile can routinely be measured within 4 min with a spatial resolution of 15 μm. If each individual layer exhibits different repellency to the test liquid, the complexity of the dynamics of the ingress can be investigated in great detail. An elegant application of the unilateral instrument was obtained in which the sensitive volume matched the region of interest of the individual layers of the textile under investigation.

  13. Revised Model of Chloride Diffusion in Concrete Bridge by Considering Complex Action of Load and Chloride Binding Capacity

    OpenAIRE

    Xiang, Yiqiang; Guo, DongMei

    2014-01-01

    Coastal concrete bridges will suffer from deterioration of RC structural performance and resistance attenuation because of the chloride penetration and other environment factors. This article discusses current different chloride diffusion models and puts forward the revised model of chloride diffusion in concrete bridge by considering the complex action of load influence and chloride-binding capacity. Comparison of numerical predicted values and relative experimental tests show the presented ...

  14. CFD analysis of air ingress distribution during mid-loop accident sequences

    International Nuclear Information System (INIS)

    The accident management approach affects nuclear technology and safety with a new formulation of basic hypotheses for the evaluation of the Source Term and radiological impact on the population due to Fission Product release following Severe Accidents. Considering also the wide spectrum of hypothetical and low probability accident scenarios having these kind of consequences, the sequences having potential for air ingress into the reactor coolant system or involving the interaction between fuel and air, which can flow into the reactor coolant system from the containment, have recently gained more and more interest. The research activities summarised in this paper have been carried out at the Department of Mechanical, Nuclear and Production Engineering of Pisa University, in the frame of an international Project of the IV European Community Framework Programme. The activity included a review of the spectrum of accident sequences to be considered for the investigation of the air ingress probability, the behaviour and the effects of air ingress into the reactor core. Two classes of scenarios were identified for a more in-depth analysis: (a) mid-loop sequences, and (b) scenarios including vessel melt-through. In this frame, mid-loop sequences, having more probabilistic interest than vessel melt-through scenarios, have been investigated by using 3D analytical tools (i.e. Fluent V5.0 fluid-dynamic code). (author)

  15. Experiments on mass transfer in a natural convection of high temperature gas mixture with graphite corrosion due to air ingress

    International Nuclear Information System (INIS)

    Experiments on mass transfer in a natural convection of gas mixture with graphite corrosion at high temperature due to air ingress have been performed to predict the thermohydraulic characteristics with high accuracy at the pipe rupture in a high temperature gas cooled reactor. The whole shape of the multi-channel test section is a reverse U shape. The one side of the reverse U shaped test section consists of two hot graphite channels and one cold metal channel which are parallel to each other. The inlet and outlet mole fractions of oxygen, carbon monoxide and carbon dioxide, the corrosion thickness of the graphite tube, the distribution of flow rates were measured under the various temperature conditions of graphite channels up to 1200degC. From these data, the relationship of Sherwood number and dimensionless distance from the inlet of the graphite channel have been obtained. It was found under the present experimental conditions that the maximum mole fraction of carbon monoxide at the outlet is 0.25% and the Sherwood numbers obtained are smaller than those calculated on assumption of analogy between heat and mass transfer. (author)

  16. FINAL REPORT on Experimental Validation of Stratified Flow Phenomena, Graphite Oxidation, and Mitigation Strategies of Air Ingress Accidents

    Energy Technology Data Exchange (ETDEWEB)

    Chang H. Oh; Eung S. Kim; Hee C. NO; Nam Z. Cho

    2011-01-01

    The U.S. Department of Energy is performing research and development that focuses on key phenomena that are important during challenging scenarios that may occur in the Next Generation Nuclear Plant (NGNP)/Generation IV very high temperature reactor (VHTR). Phenomena Identification and Ranking studies to date have identified the air ingress event, following on the heels of a VHTR depressurization, as very important. Consequently, the development of advanced air ingress-related models and verification & validation are of very high priority for the NGNP Project. Following a loss of coolant and system depressurization incident, air ingress will occur through the break, leading to oxidation of the in-core graphite structure and fuel. This study indicates that depending on the location and the size of the pipe break, the air ingress phenomena are different. In an effort to estimate the proper safety margin, experimental data and tools, including accurate multidimensional thermal-hydraulic and reactor physics models, a burn-off model, and a fracture model are required. It will also require effective strategies to mitigate the effects of oxidation, eventually. This 3-year project (FY 2008–FY 2010) is focused on various issues related to the VHTR air-ingress accident, including (a) analytical and experimental study of air ingress caused by density-driven, stratified, countercurrent flow, (b) advanced graphite oxidation experiments, (c) experimental study of burn-off in the core bottom structures, (d) structural tests of the oxidized core bottom structures, (e) implementation of advanced models developed during the previous tasks into the GAMMA code, (f) full air ingress and oxidation mitigation analyses, (g) development of core neutronic models, (h) coupling of the core neutronic and thermal hydraulic models, and (i) verification and validation of the coupled models.

  17. Analysis of the dynamics of hydrogen ingress to secondary sodium after the replacement of the steam generator stages of the BN-600 power unit

    International Nuclear Information System (INIS)

    The article presents the calculation methodology of hydrogen ingress rate into secondary circuit sodium of the BN-600 power unit. The sources and the mechanism of the hydrogen ingress after the replacement of a lot of the PGN-200M steam generator stages within the scope of work on the power unit operation lifetime extension were defined. The hydrogen ingress rate after impending replacements of steam generator stages was estimated

  18. Implications of Air Ingress Induced by Density-Difference Driven Stratified Flow

    International Nuclear Information System (INIS)

    One of the design basis accidents for the Next Generation Nuclear Plant (NGNP), a high temperature gas-cooled reactor, is air ingress subsequent to a pipe break. Following a postulated double-ended guillotine break in the hot duct, and the subsequent depressurization to nearly reactor cavity pressure levels, air present in the reactor cavity will enter the reactor vessel via density-gradient-driven-stratified flow. Because of the significantly higher molecular weight and lower initial temperature of the reactor cavity air-helium mixture, in contrast to the helium in the reactor vessel, the air-helium mixture in the cavity always has a larger density than the helium discharging from the reactor vessel through the break into the reactor cavity. In the later stages of the helium blowdown, the momentum of the helium flow decreases sufficiently for the heavier cavity air-helium mixture to intrude into the reactor vessel lower plenum through the lower portion of the break. Once it has entered, the heavier gas will pool at the bottom of the lower plenum. From there it will move upwards into the core via diffusion and density-gradient effects that stem from heating the air-helium mixture and from the pressure differences between the reactor cavity and the reactor vessel. This scenario (considering density-gradient-driven stratified flow) is considerably different from the heretofore commonly used scenario that attributes movement of air into the reactor vessel and from thence to the core region via diffusion. When density-gradient-driven stratified flow is considered as a contributing phenomena for air ingress into the reactor vessel, the following factors contribute to a much earlier natural circulation-phase in the reactor vessel: (a) density-gradient-driven stratified flow is a much more rapid mechanism (at least one order of magnitude) for moving air into the reactor vessel lower plenum than diffusion, and consequently, (b) the diffusion dominated phase begins with a

  19. Implications of Air Ingress Induced by Density-Difference Driven Stratified Flow

    Energy Technology Data Exchange (ETDEWEB)

    Chang Oh; Eung Soo Kim; Richard Schultz; David Petti; C. P. Liou

    2008-06-01

    One of the design basis accidents for the Next Generation Nuclear Plant (NGNP), a high temperature gas-cooled reactor, is air ingress subsequent to a pipe break. Following a postulated double-ended guillotine break in the hot duct, and the subsequent depressurization to nearly reactor cavity pressure levels, air present in the reactor cavity will enter the reactor vessel via density-gradient-driven-stratified flow. Because of the significantly higher molecular weight and lower initial temperature of the reactor cavity air-helium mixture, in contrast to the helium in the reactor vessel, the air-helium mixture in the cavity always has a larger density than the helium discharging from the reactor vessel through the break into the reactor cavity. In the later stages of the helium blowdown, the momentum of the helium flow decreases sufficiently for the heavier cavity air-helium mixture to intrude into the reactor vessel lower plenum through the lower portion of the break. Once it has entered, the heavier gas will pool at the bottom of the lower plenum. From there it will move upwards into the core via diffusion and density-gradient effects that stem from heating the air-helium mixture and from the pressure differences between the reactor cavity and the reactor vessel. This scenario (considering density-gradient-driven stratified flow) is considerably different from the heretofore commonly used scenario that attributes movement of air into the reactor vessel and from thence to the core region via diffusion. When density-gradient-driven stratified flow is considered as a contributing phenomena for air ingress into the reactor vessel, the following factors contribute to a much earlier natural circulation-phase in the reactor vessel: (a) density-gradient-driven stratified flow is a much more rapid mechanism (at least one order of magnitude) for moving air into the reactor vessel lower plenum than diffusion, and consequently, (b) the diffusion dominated phase begins with a

  20. Results of the QUENCH-10 air ingress test using ATHLET-CD

    International Nuclear Information System (INIS)

    In case of a postulated breakdown of the main and the emergency cooling systems during a loss of cooling accident in light water reactors, severe core damage or even core degradation is possible. To avoid the total melting of the core, the uncovered and overheated core has to be cooled, i. e. by flooding with water. In the framework of the QUENCH programme at Forschungszentrum Karlsruhe (FZK) the behaviour of fuel rod bundles during reflood scenarios is investigated. A specific focus lays on the hydrogen generation due to the exothermal zirconium-steam-reaction during the quench phase, but additionally B44C oxidation as well as air ingress is investigated. Based on the post-test calculations of the QUENCH tests with the severe accident code ATHLET-CD the capability of the code can be established and evaluated. In the following the post-test calculation of the experiment QUENCH-10 with ATHLET-CD 2.1A is presented and discussed. The QUENCH-10 test was performed on the 21st of July 2004 at FZK in the framework of the EC-supported LACOMERA programme to improve the knowledge of the phenomena during an air ingress scenario with the objective to observe the oxidation and nitride formation processes and to investigate the bundle behaviour during the subsequent quenching by water. A postulated loss of heat removal in a spent fuel pool or loss of coolant accident in a reactor application could lead to the evaporation of the water in the pool and the degradation of the fuel assemblies by air ingress which could lead to fission product release from the degraded core. (orig.)

  1. Results of the QUENCH-10 air ingress test using ATHLET-CD

    Energy Technology Data Exchange (ETDEWEB)

    Hollands, Thorsten; Drath, Tilman; Wagner, Hermann-Josef; Koch, Marco K. [Bochum Univ. (RUB) (DE). Lehrstuhl fuer Energiesysteme und Energiewirtschaft (LEE)

    2008-07-01

    In case of a postulated breakdown of the main and the emergency cooling systems during a loss of cooling accident in light water reactors, severe core damage or even core degradation is possible. To avoid the total melting of the core, the uncovered and overheated core has to be cooled, i. e. by flooding with water. In the framework of the QUENCH programme at Forschungszentrum Karlsruhe (FZK) the behaviour of fuel rod bundles during reflood scenarios is investigated. A specific focus lays on the hydrogen generation due to the exothermal zirconium-steam-reaction during the quench phase, but additionally B{sub 4}4C oxidation as well as air ingress is investigated. Based on the post-test calculations of the QUENCH tests with the severe accident code ATHLET-CD the capability of the code can be established and evaluated. In the following the post-test calculation of the experiment QUENCH-10 with ATHLET-CD 2.1A is presented and discussed. The QUENCH-10 test was performed on the 21{sup st} of July 2004 at FZK in the framework of the EC-supported LACOMERA programme to improve the knowledge of the phenomena during an air ingress scenario with the objective to observe the oxidation and nitride formation processes and to investigate the bundle behaviour during the subsequent quenching by water. A postulated loss of heat removal in a spent fuel pool or loss of coolant accident in a reactor application could lead to the evaporation of the water in the pool and the degradation of the fuel assemblies by air ingress which could lead to fission product release from the degraded core. (orig.)

  2. Uncertainties in the analysis of water ingress accident for the HTGR cores

    International Nuclear Information System (INIS)

    Behaviour of the reactor major physical characteristics during the accident related to the water/steam ingress into the core, resulted from the steam generator (SG) loss of integrity has been analysed on the example of the VGM reactor with the pebble bed core designed in the USSR. The header tube instantaneous double-ended rupture without interaction of the outgoing flows has been considered due to the uncertainties of its failure process. Calculation of water quantity discharged into the core has been made under the following assumptions: 1) Accumulation of water in liquid state in the core is eliminated in as much as the fuel elements and helium temperature exceed water boiling temperature at a pressure of about 5 MPa: 2) Chemical interaction of water with graphite is not taken into account: 3) Moisture sensors fail to be actuated. The calculation results of the water mass variations in the core vs. time as well as reactivity changes caused by water ingress into the core are given in the paper. The need to take into account reactivity changes caused by the front edge of the steam/helium mixture that defines the neutron power increase rate has been shown is the paper. Changes of the reactivity compensation members' efficiency at a steam/water ingress into the core and reflector both in hot and cooled down reactor have been evaluated. The paper carries requirements for experimental investigations intended to prove the adequacy of the reactivity compensation members' efficiency in the accident under consideration. (author). 6 refs, 3 figs

  3. Simulation of the air ingress experiment QUENCH-16 with ATHLET-CD

    International Nuclear Information System (INIS)

    The severe accident analysis code ATHLET-CD is developed in order to analyze the behavior of Light-Water-Reactors under severe accident conditions. The objective of the code development is to provide a reliable tool for safety analysis of LWR, for instance, to assess the effectiveness of accident management measures at different stages of core degradation. Reflooding an uncovered core as a measure to prevent core damage may result in an accelerated zirconium oxidation. Besides a significant hydrogen generation, this reaction may cause a temperature escalation leading to the failure of the claddings. Therefore current research activities focus on the investigation of the behavior of fuel rod bundles during reflooding at high temperatures. In case of air ingress in the course of severe accidents, e. g. in dried-out spent fuel ponds, the high temperature interaction of fuel materials with air results in intense oxidation and nitriding of zirconium components. Under these conditions, severe bundle damages may occur even though the bundle can successfully be quenched by water. Two tests addressing the investigation of the bundle behaviour during air ingress followed by a subsequent bottom flooding with water have been performed in the QUENCH-facility at Karlsruhe Institute of Technology (KIT). The purpose of both air ingress tests, QUENCH-10 and QUNENCH-16, was to provide experimental data needed for model development as well as code validation. In contrast to QUENCH-10, the boundary conditions of QUENCH-16 in terms of the injection of air were chosen to extent the oxygen starvation period in order to investigate the impact of nitride formation on the bundle behaviour. The purpose of the post-test calculation of the experiment QUENCH-16 with the system code ATHLET-CD presented in this compact is to assess the current modeling of zirconium (Zr) oxidation in air. The results are presented and discussed in comparison to the measurements. (orig.)

  4. Simulation of the air ingress experiment QUENCH-16 with ATHLET-CD

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann, Mathias; Koch, Marco K. [Bochum Univ. (Germany). Chair of Energy Systems and Energy Economics (LEE)

    2012-11-01

    The severe accident analysis code ATHLET-CD is developed in order to analyze the behavior of Light-Water-Reactors under severe accident conditions. The objective of the code development is to provide a reliable tool for safety analysis of LWR, for instance, to assess the effectiveness of accident management measures at different stages of core degradation. Reflooding an uncovered core as a measure to prevent core damage may result in an accelerated zirconium oxidation. Besides a significant hydrogen generation, this reaction may cause a temperature escalation leading to the failure of the claddings. Therefore current research activities focus on the investigation of the behavior of fuel rod bundles during reflooding at high temperatures. In case of air ingress in the course of severe accidents, e. g. in dried-out spent fuel ponds, the high temperature interaction of fuel materials with air results in intense oxidation and nitriding of zirconium components. Under these conditions, severe bundle damages may occur even though the bundle can successfully be quenched by water. Two tests addressing the investigation of the bundle behaviour during air ingress followed by a subsequent bottom flooding with water have been performed in the QUENCH-facility at Karlsruhe Institute of Technology (KIT). The purpose of both air ingress tests, QUENCH-10 and QUNENCH-16, was to provide experimental data needed for model development as well as code validation. In contrast to QUENCH-10, the boundary conditions of QUENCH-16 in terms of the injection of air were chosen to extent the oxygen starvation period in order to investigate the impact of nitride formation on the bundle behaviour. The purpose of the post-test calculation of the experiment QUENCH-16 with the system code ATHLET-CD presented in this compact is to assess the current modeling of zirconium (Zr) oxidation in air. The results are presented and discussed in comparison to the measurements. (orig.)

  5. Contaminant ingress into multizone buildings: An analytical state-space approach

    DEFF Research Database (Denmark)

    Parker, Simon; Coffey, Chris; Gravesen, Jens;

    2014-01-01

    The ingress of exterior contaminants into buildings is often assessed by treating the building interior as a single well-mixed space. Multizone modelling provides an alternative way of representing buildings that can estimate concentration time series in different internal locations. A state...... term maximum concentration and exposure in a multizone building in response to a step-change in concentration. These have considerable potential for practical use. The analytical development is demonstrated using a simple two-zone building with an inner zone and a range of existing multizone models...

  6. Do predator-prey relationships on the river bed affect fine sediment ingress?

    Science.gov (United States)

    Mathers, Kate; Rice, Stephen; Wood, Paul

    2016-04-01

    Ecosystem engineers are organisms that alter their physical environment and thereby influence the flow of resources through ecosystems. In rivers, several ecosystem engineers are also important geomorphological agents that modify fluvial sediment dynamics. By altering channel morphology and bed material characteristics, such modifications can affect the availability of habitats for other organisms, with implications for ecosystem health and wider community composition. In this way geomorphological and ecological systems are intimately interconnected. This paper focuses on one element of this intricate abiotic-biotic coupling: the interaction between fine sediment ingress into the river bed and the predator-prey relationships of aquatic organisms living on and in the river bed. Signal crayfish (Pacifastacus leniusculus) have been shown to modify fine sediment fluxes in rivers, but their effect on fine sediment ingress into riverbeds remains unclear. Many macroinvertebrate taxa have adapted avoidance strategies to avoid predation by crayfish, with one example being the freshwater shrimp (Gammarus pulex) which relies on open interstitial spaces within subsurface sediments as a refuge from crayfish predation. Fine sedimentation that fills gravelly frameworks may preclude access to those spaces, therefore leaving freshwater shrimp susceptible to predation. Ex-situ experiments were conducted which sought to examine: i) if freshwater shrimps and signal crayfish, alone and in combination, influenced fine sediment infiltration rates; and ii) whether modifications to substratum composition, specifically the introduction of fine sediment, modified predator-prey interactions. The results demonstrate that crayfish are significant geomorphic agents and that fine sediment ingress rates were significantly enhanced in their presence compared to control conditions or the presence of only freshwater shrimps. The combination of both organisms (i.e. allowing the interaction between

  7. Chloride Transport in Undersea Concrete Tunnel

    Directory of Open Access Journals (Sweden)

    Yuanzhu Zhang

    2016-01-01

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

  8. Separate-effects experiments on the hydrodynamics of air ingress phenomena for the very high temperature reactor

    International Nuclear Information System (INIS)

    The present study performs scaled separate-effects experiments to investigate the hydrodynamics in the air-ingress phenomena following a Depressurized Condition Cooldown in the Very High Temperature Gas-Cooled Reactor. First, a scoping experiment using water and brine is performed. The volumetric exchange rate is measured using a hydrometer, and flow visualizations are performed. Next, Helium-air experiments are performed to obtain three-dimensional oxygen concentration transient data using an oxygen analyzer. It is found that there exists a critical density difference ratio, before which the ingress rate increases linearly with time and after which the ingress rate slows down significantly. In both the water-brine and Helium-air experiments, this critical ratio is found to be approximately 0.7. (author)

  9. Reactivity Effect Of Steam / Water Ingress in Generation-IV Gas-Cooled Fast Reactor Core

    International Nuclear Information System (INIS)

    This paper presents a static neutronic calculational study of steam/water ingress into a Gas-cooled Fast Reactor (GFR Generation IV) core performed by using three Monte-Carlo codes, namely SERPENT version 1.1-16, KENO-VI module of the SCALE, MCNPX version 2.7.0, and different modern nuclear data libraries, i.e. JEFF-3.1, JEFF-3.1.1 and ENDF/B-VII. The analysis was performed for a wide range of water/steam densities [0 – 1.0 g/cm3] within the core and the neutronic parameters were compared between the different codes and libraries. The obtained results demonstrate that this accidental event would result in a large negative reactivity insertion. The main reason of such core behaviour was found to be an increased neutron absorption rate in the cladding liner made of refractory metals (W and Re) due to the neutron spectrum thermalisation resulting from the steam/water ingress. (author)

  10. Air and water ingress accidents in a HTR-modul of side-by-side concept

    International Nuclear Information System (INIS)

    Since the possibility of a temperature induced release of fission products from the core has been eliminated by the design of the HTR-Modul, the question arose whether corrosion by air can result in a significant release of fission products. Massive air ingress is only possible by natural convection and requires three large leaks in the pressure boundary at suitable positions (chimney effect). Such an event is hardly imaginable, since the occurrence of one leak already eliminates the mechanism for the formation of additional leaks. Nevertheless this highly hypothetical event was considered in order to get knowledge about the behaviour of the system under these extreme conditions. The results show that the maximal degree of corrosion of fuel elements remains low for a long period of time, since the corrosion zone moves through the pebble bed core. A massive release of fission products is significantly delayed, thus plenty of time is available for counter measures. Water ingress accidents proved to be dominant for the risk of a HTR-Modul. This is due to the fact that fission products deposited on the surface of the primary circuit can be remobilized by reaction with water and steam and can be released from the primary circuit via two release paths. One path leads via the relief valve and the ventilation system to the stack, the other via the steam generator leak and the dump line, if a dump line valve fails to close

  11. Augmin shapes the anaphase spindle for efficient cytokinetic furrow ingression and abscission.

    Science.gov (United States)

    Uehara, Ryota; Kamasaki, Tomoko; Hiruma, Shota; Poser, Ina; Yoda, Kinya; Yajima, Junichiro; Gerlich, Daniel W; Goshima, Gohta

    2016-03-01

    During anaphase, distinct populations of microtubules (MTs) form by either centrosome-dependent or augmin-dependent nucleation. It remains largely unknown whether these different MT populations contribute distinct functions to cytokinesis. Here we show that augmin-dependent MTs are required for the progression of both furrow ingression and abscission. Augmin depletion reduced the accumulation of anillin, a contractile ring regulator at the cell equator, yet centrosomal MTs were sufficient to mediate RhoA activation at the furrow. This defect in contractile ring organization, combined with incomplete spindle pole separation during anaphase, led to impaired furrow ingression. During the late stages of cytokinesis, astral MTs formed bundles in the intercellular bridge, but these failed to assemble a focused midbody structure and did not establish tight linkage to the plasma membrane, resulting in furrow regression. Thus augmin-dependent acentrosomal MTs and centrosomal MTs contribute to nonredundant targeting mechanisms of different cytokinesis factors, which are required for the formation of a functional contractile ring and midbody. PMID:26764096

  12. Suppressing hydrogen ingress during aqueous corrosion of CANDU Zr-2.5 Nb pressure tube material

    International Nuclear Information System (INIS)

    As a result of their special properties, including low neutron cross-section and intrinsic corrosion resistance, Zr alloys are used in the fabrication of nuclear core components, particularly fuel cladding (in most reactor types) and also Zr-2.5 Nb pressure tubes in CANDU trademark (Canada Deuterium Uranium) reactors. Corrosion and H uptake during service can limit the life of these components. Therefore, remedial action may be appropriate to slow the H uptake rate and prolong the working life of these reactor components. This work has explored the possibility of reducing H uptake in pressure tube material by incorporating an inhibiting agent into the corrosion environment. Two approaches have been tested, depositing a thin metallic film on the initial oxide surface and adding an inhibiting agent to the solution. The latter approach appears more practical. Screening experiments were conducted in short-term (∝30 day) exposures in high temperature (340 C) aqueous out-reactor environments, simulating the CANDU trademark heat transport coolant with various chemistries. Compounds tested included aluminum acetate, aluminum nitrate, lithium nitrate, rhodium nitrate and yttrium nitrate. Comparison of results from the aluminum nitrate additives and aluminum acetate additives suggests that the nitrate anion is the effective ingredient for H ingress inhibition. The nitrate anion appears to reduce the rate of H ingress regardless of the associated cation. However, each cation appears to affect the rate of corrosion differently. These cations were found to be incorporated in the oxide film. (authors)

  13. Ingression Progression Complexes Control Extracellular Matrix Remodelling during Cytokinesis in Budding Yeast

    Science.gov (United States)

    Foltman, Magdalena; Molist, Iago; Arcones, Irene; Sacristan, Carlos; Filali-Mouncef, Yasmina; Roncero, Cesar; Sanchez-Diaz, Alberto

    2016-01-01

    Eukaryotic cells must coordinate contraction of the actomyosin ring at the division site together with ingression of the plasma membrane and remodelling of the extracellular matrix (ECM) to support cytokinesis, but the underlying mechanisms are still poorly understood. In eukaryotes, glycosyltransferases that synthesise ECM polysaccharides are emerging as key factors during cytokinesis. The budding yeast chitin synthase Chs2 makes the primary septum, a special layer of the ECM, which is an essential process during cell division. Here we isolated a group of actomyosin ring components that form complexes together with Chs2 at the cleavage site at the end of the cell cycle, which we named ‘ingression progression complexes’ (IPCs). In addition to type II myosin, the IQGAP protein Iqg1 and Chs2, IPCs contain the F-BAR protein Hof1, and the cytokinesis regulators Inn1 and Cyk3. We describe the molecular mechanism by which chitin synthase is activated by direct association of the C2 domain of Inn1, and the transglutaminase-like domain of Cyk3, with the catalytic domain of Chs2. We used an experimental system to find a previously unanticipated role for the C-terminus of Inn1 in preventing the untimely activation of Chs2 at the cleavage site until Cyk3 releases the block on Chs2 activity during late mitosis. These findings support a model for the co-ordinated regulation of cell division in budding yeast, in which IPCs play a central role. PMID:26891268

  14. Defending of IP Spoofing by Ingress Filter in Extended-Inter Domain Packet Key Marking System

    Directory of Open Access Journals (Sweden)

    G.Velmayil

    2013-04-01

    Full Text Available The significance of the DDoS problem and the increased occurrence and strength of attacks has led to the dawn of numerous prevention mechanisms. IP spoofing is most frequently used in denial-of-service attacks. In such attacks, the goal is to flood the victim with overwhelming amounts of traffic, and the attacker does not care about receiving responses to the attack packets. IP spoofing is one of the basic weaknesses in the Internet Protocol to launch the DDOS attack. Each prevention mechanism has some unique advantages and disadvantages over the others. The existing methods become ineffective due to a large number of filters required and they lack in information about where to place the filter. We propose Ingress filter in Extended Inter Domain Packet Key marking system .This paper comprises of two functional blocks namely, Key marking system and filtering blocks. In the marking block, each source is labeled with a key. The key is changed continuously for a certain period of time to provide secured system and is validated at border routers. In the filtering block, spoofed packets are filtered at the border router using Ingress filter to filter beyond periphery routers. The filter placement algorithm clearly put forwards the conditions under which the filter can operate accurately. The accuracy of the proposed systems is validated using Network Simulator (NS-2.

  15. Rapid chloride permeability test for durability study of carbon nanoreinforced mortar

    Science.gov (United States)

    Alafogianni, P.; Dalla, P. T.; Tragazikis, I. K.; Barkoula, N.-M.; Matikas, T. E.

    2015-03-01

    The addition of a conductive admixture in a cement-based material could lead to innovative products with multifunctional features. These materials are designed to possess enhanced properties, such as improved mechanical properties, electrical and thermal conductivity, and piezo-electric characteristics. Carbon nanotubes (CNTs) can be used as nano-reinforcement in cement-based materials because of their huge aspect ratio as well as their extremely large specific surface area. For cement-based composites, one of the major types of environmental attack is the chloride ingress, which leads to corrosion of the material and, subsequently, to the reduction of strength and serviceability of the structure. A common method of preventing such deterioration is to avert chlorides from penetrating the structure. The penetration of the concrete by chloride ions is a slow process. It cannot be determined directly in a time frame that would be useful as a quality control measure. Therefore, in order to assess chloride penetration, a test method that accelerates the process is needed, to allow the determination of diffusion values in a reasonable time. In the present research, nanomodified mortars with various concentrations of multi-wall carbon nanotubes (0.2% wt. cement CNTs - 0.6% wt. cement CNTs) were used. The chloride penetration in these materials was monitored according to ASTM C1202 standard. This is known as the Coulomb test or Rapid Chloride Permeability Test (RCPT).

  16. Testing the Hydrological Landscape Unit Classification System and Other Terrain Analysis Measures for Predicting Low-Flow Nitrate and Chloride in Watersheds

    OpenAIRE

    Poor, C.J.; J. J. McDonnell; Bolte, J.

    2008-01-01

    Elevated nitrate concentrations in streamwater are a major environmental management problem. While land use exerts a large control on stream nitrate, hydrology often plays an equally important role. To date, predictions of low-flow nitrate in ungauged watersheds have been poor because of the difficulty in describing the uniqueness of watershed hydrology over large areas. Clearly, hydrologic response varies depending on the states and stocks of water, flow pathways, and residence times. How to...

  17. SR-Site: Oxygen ingress in the rock at Forsmark during a glacial cycle

    International Nuclear Information System (INIS)

    The aim of this report is to assess the possibility for oxygen to be transported by glacial melt-water to canister positions in a final repository for spent nuclear fuel at the proposed location in Forsmark. The approach for this assessment is to combine reactive transport modelling with geological observations of present and historical indications of oxygen ingress. For safety assessment purposes a cautious approach in the modelling is required when estimating the extent of oxygen ingress. In this report, a cautious approach has been applied both in the conceptualisation of the problem and in the choice of input parameters used in the models. Oxygen consuming processes are only neglected in the modelling if they are expected to further decrease the extent of oxygen ingress. Several oxygen consuming processes have been identified, each of which may play an important role in the scavenging of oxygen along recharge flow paths in the rock. These processes include biological pathways with degradation of organic material of ground surface origin, and biotically mediated reactions with reduced rock minerals and with various materials expected to be present in the backfilled repository volume. In the absence of microbes most of these reactions may also follow abiotic pathways. Present day observations show that degradation of organic material is the most powerful oxygen scavenging process. At Forsmark, oxygen is generally depleted within a few metres under present day temperate conditions. Although biological activity is likely to exist also during different phases of a glaciation, large uncertainties exist regarding e.g. the population growth dynamics, the biotic reaction rates and the availability of organic material under the highly varying conditions expected. Microbial activity and degradation of organic material is therefore pessimistically neglected in the calculations in this report. In the absence of organic material, ferrous iron present in minerals in the rock

  18. SR-Site: Oxygen ingress in the rock at Forsmark during a glacial cycle

    Energy Technology Data Exchange (ETDEWEB)

    Sidborn, Magnus (Kemakta Konsult AB (Sweden)); Sandstroem, Bjoern (WSP Sverige AB (Sweden)); Tullborg, Eva-Lena (Terralogica AB (Sweden)); Salas, Joaquin; Maia, Flavia; Delos, Anne; Molinero, Jorge (Amphos21 (Spain)); Hallbeck, Lotta; Pedersen, Karsten (Microbial Analytics Sweden AB (Sweden))

    2010-11-15

    The aim of this report is to assess the possibility for oxygen to be transported by glacial melt-water to canister positions in a final repository for spent nuclear fuel at the proposed location in Forsmark. The approach for this assessment is to combine reactive transport modelling with geological observations of present and historical indications of oxygen ingress. For safety assessment purposes a cautious approach in the modelling is required when estimating the extent of oxygen ingress. In this report, a cautious approach has been applied both in the conceptualisation of the problem and in the choice of input parameters used in the models. Oxygen consuming processes are only neglected in the modelling if they are expected to further decrease the extent of oxygen ingress. Several oxygen consuming processes have been identified, each of which may play an important role in the scavenging of oxygen along recharge flow paths in the rock. These processes include biological pathways with degradation of organic material of ground surface origin, and biotically mediated reactions with reduced rock minerals and with various materials expected to be present in the backfilled repository volume. In the absence of microbes most of these reactions may also follow abiotic pathways. Present day observations show that degradation of organic material is the most powerful oxygen scavenging process. At Forsmark, oxygen is generally depleted within a few metres under present day temperate conditions. Although biological activity is likely to exist also during different phases of a glaciation, large uncertainties exist regarding e.g. the population growth dynamics, the biotic reaction rates and the availability of organic material under the highly varying conditions expected. Microbial activity and degradation of organic material is therefore pessimistically neglected in the calculations in this report. In the absence of organic material, ferrous iron present in minerals in the rock

  19. Investigation of Countercurrent Helium-Air Flows in Air-ingress Accidents for VHTRs

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Xiaodong; Christensen, Richard; Oh, Chang

    2013-10-03

    The primary objective of this research is to develop an extensive experimental database for the air- ingress phenomenon for the validation of computational fluid dynamics (CFD) analyses. This research is intended to be a separate-effects experimental study. However, the project team will perform a careful scaling analysis prior to designing a scaled-down test facility in order to closely tie this research with the real application. As a reference design in this study, the team will use the 600 MWth gas turbine modular helium reactor (GT-MHR) developed by General Atomic. In the test matrix of the experiments, researchers will vary the temperature and pressure of the helium— along with break size, location, shape, and orientation—to simulate deferent scenarios and to identify potential mitigation strategies. Under support of the Department of Energy, a high-temperature helium test facility has been designed and is currently being constructed at Ohio State University, primarily for high- temperature compact heat exchanger testing for the VHTR program. Once the facility is in operation (expected April 2009), this study will utilize high-temperature helium up to 900°C and 3 MPa for loss-of-coolant accident (LOCA) depressurization and air-ingress experiments. The project team will first conduct a scaling study and then design an air-ingress test facility. The major parameter to be measured in the experiments is oxygen (or nitrogen) concentration history at various locations following a LOCA scenario. The team will use two measurement techniques: 1) oxygen (or similar type) sensors employed in the flow field, which will introduce some undesirable intrusiveness, disturbing the flow, and 2) a planar laser-induced fluorescence (PLIF) imaging technique, which has no physical intrusiveness to the flow but requires a transparent window or test section that the laser beam can penetrate. The team will construct two test facilities, one for high-temperature helium tests with

  20. 36 CFR 14.5 - Nature of interest granted; settlement on right-of-way; rights of ingress and egress.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Nature of interest granted; settlement on right-of-way; rights of ingress and egress. 14.5 Section 14.5 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR RIGHTS-OF-WAY Nature of Interest § 14.5...

  1. Design and test of reliable high strength ingressive polycrystalline silicon microgripper arrays

    International Nuclear Information System (INIS)

    We present the design and validation of a micromachined gripper array that enables reliable transmission of forces of at least 14 mN. The gripper is constructed with polycrystalline silicon (polysilicon), a brittle material, and is compatible with polysilicon surface micromachining. Two ingressive snap-and-lock array designs are presented. After developing design guidelines, it is shown that the first gripper array is functional. However, a risk remains that the gripper array rather than the tensile bar that it grips in its intended application fails. Therefore, an improved geometry is designed and it is shown that it is robust with respect to failure. Scanning confocal Raman imaging directly confirms that the local peak tensile stresses in the robust gripper array are approximately 50% of the lower bound material strength, and also resolves a 25% stress variation across the array. (paper)

  2. Design and test of reliable high strength ingressive polycrystalline silicon microgripper arrays

    Science.gov (United States)

    Hazra, S. S.; Beuth, J. L.; Myers, G. A.; DelRio, F. W.; de Boer, M. P.

    2015-01-01

    We present the design and validation of a micromachined gripper array that enables reliable transmission of forces of at least 14 mN. The gripper is constructed with polycrystalline silicon (polysilicon), a brittle material, and is compatible with polysilicon surface micromachining. Two ingressive snap-and-lock array designs are presented. After developing design guidelines, it is shown that the first gripper array is functional. However, a risk remains that the gripper array rather than the tensile bar that it grips in its intended application fails. Therefore, an improved geometry is designed and it is shown that it is robust with respect to failure. Scanning confocal Raman imaging directly confirms that the local peak tensile stresses in the robust gripper array are approximately 50% of the lower bound material strength, and also resolves a 25% stress variation across the array.

  3. Water ingress into a casein film quantified using time-resolved neutron imaging.

    Science.gov (United States)

    Metwalli, E; Hermes, H E; Calzada, E; Kulozik, U; Egelhaaf, S U; Müller-Buschbaum, P

    2016-03-01

    The migration of water into a casein film was probed with neutron radiography. From the neutron transmission images, the evolution of the water saturation profiles was extracted. The results indicate that the water influx is dominated by imbibition but also contains a diffusional component. The time dependence of the water ingress was quantified using a diffusion-like equation previously also applied to imbibition. A water transport coefficient D = 0.9 × 10(-9) m(2) s(-1) was found. This value and direct observation of the images indicate that the time taken for a typical adhesive casein-based layer to become saturated with water is of the order of hours. PMID:26862596

  4. Influence of heat treatment on hydrogen ingress into V-4Cr-4Ti alloy

    Science.gov (United States)

    Hayakawa, Ryo; Hatano, Yuji; Fukumoto, Ken-ichi; Matsui, Hideki; Watanabe, Kuniaki

    2004-08-01

    Specimens of V-4Cr-4Ti alloy were heated at 1273 K in vacuum, and the influence of this heat treatment on H 2 absorption was examined at temperatures from 523 to 1023 K under the presence of water vapor of 10 -5 Pa. The rate of H 2 absorption was significantly reduced by the heat treatment in the temperature range examined. Such reduction in the absorption rate was ascribed to the surface segregation of Ti and increase in surface oxygen coverage caused by preferential oxidation of segregating Ti by water vapor. Comparison with data reported by other researchers [J. Nucl. Mater. 233-237 (1996) 376; Fusion Technol. 34 (1998) 868; J. Nucl. Mater. 233-237 (1996) 510] indicated the strong barrier effect of Ti oxide against hydrogen ingress.

  5. CODEX-AIT-2 experiment. Core degradation test with steam oxidation and air ingress

    International Nuclear Information System (INIS)

    The CODEX-AIT-2 test was performed in the CODEX facility in order to study the fuel rod degradation in the pre-oxidised bundle under air ingress conditions. The fuel rod cladding was oxidised in steam atmosphere in two steps: at 820 deg C and 950 deg C to give an oxide layer thickness of 20-25 microns. After the air injection temperature excursion was observed on the fuel rods to a maximum indicated temperature of 1900 deg C. In the AIT-2 test the damage of the bundle was more severe than in the first test, for the high temperature conditions were kept for longer time in AIT-2 than in AIT-1. The rod-like structure was lost in the upper part of the bundle. The formation of higher uranium oxides was not observed. (author)

  6. Resistance of a novel root canal sealer to bacterial ingress in vitro.

    Science.gov (United States)

    Padachey, N; Patel, V; Santerre, P; Cvitkovitch, D; Lawrence, H P; Friedman, S

    2000-11-01

    A dentin-bonding root canal sealer (ZUT) has been developed, consisting of an experimental glass ionomer cement (KT-308) and an antimicrobial silver-containing zeolite (0.2% by weight). This in vitro study evaluated the ability of ZUT used with or without gutta-percha, to resist bacterial ingress of Enterococcus faecalis over a period of 90 days. Canals of 80 single-rooted teeth were prepared with apical patency and filled as follows (n = 10): KT-308 alone; KT-308 with a single gutta-percha cone (SCGP); ZUT alone; ZUT with SCGP; AH26 alone; AH26 with SCGP; positive control-no root canal filling; and negative control-no root canal filling, with the apices of this group sealed with C&B Metabond cement. Teeth were coated with nail polish except for the apical 2 mm, and each tooth was sealed in a 4-ml glass vial, with an 18-gauge needle inserted through the vial cover and bonded into the pulp chamber with C&B Metabond cement. After sterilization with 2.5 Mrad gamma-radiation, Brain Heart Infusion broth with phenol red was injected into each vial. An inoculum of E. faecalis was pipetted through the needle into the pulp chamber every 5 days, and the broth was monitored daily for color change and turbidity. When change occurred, the broth was cultured for growth of E. faecalis. Kaplan-Meier survival analysis and the log-rank test revealed no significant differences among the three sealers used. The presence of gutta-percha, however, significantly improved resistance to bacterial ingress through obturated root canals (X, p < 0.05). Under the conditions of this study, the hypothesized advantage of ZUT (0.2% zeolite) was not demonstrated. PMID:11469295

  7. Effect of air ingress on the energy performance of coal fired thermal power plants

    International Nuclear Information System (INIS)

    Ingress of air in boilers leads to drops in energy efficiency. This paper presents the effects of air ingress in the combustion zone, post-combustion zone and air pre-heater (APH) on the energy efficiency and loading capacity of a coal fired thermal power plant operating on fuel with high ash (35-45%). The optimal O2 in the flue gas for a pulverized coal fired system is 3.5% (corresponding to 20% excess air). The operating values are in the range of 4.2-6.0% in membrane type boilers and up to 10% in refractory type boilers (after sustained periods of operation). The leakage rate of boilers (up to the entrance of the APH) is designed at 0.2% while the average operating values are 7.25% for membrane type enclosures and 33.61% for refractory enclosures. The leakage rate of the APH is designed at 5.0% while the operating values range from 13.66% to 20.13% for rotary and tubular APHs. When the O2 in the combustion zone varies from 3.5% to 8.0%, efficiency drops of 2.0% points are experienced in the boiler and turbine separately, and the gross overall efficiency drop is ∼3.0% points. The units do not experience any capacity drop up to an O2 in the flue gas of 6.0% before the APH. At an O2 in the flue gas (before APH) of 7.2%, a mild limitation on the unit capacity of around 2-3% is experienced. When O2 in the flue gas (before APH) reaches a level of 9.0%, 20% capacity drop of the unit is experienced due to which the plant load cannot be raised higher than 80%. Beyond the level of 9.0% (rare occurrence), the unit is quite difficult to operate and has to be taken off for overhaul

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

    International Nuclear Information System (INIS)

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

  9. Air ingress and graphite burning in HTRs: A survey on analytical examinations performed with the code React/Thermix

    International Nuclear Information System (INIS)

    Analyses on air ingress in the pebble bed reactors PNP-500, THTR-300, HTR-Modul, AVR-II and AVR process heat plant are outlined; in addition, some results for the VHTR with block type fuel are given. Air ingress requires primary circuit depressurization and large leak(s) to reactor buildings and environment and belongs therefore to highly hypothetical events in the sense of classical safety analysis. One accident class examined is air ingress with forced flow by emergency cooling: For this case, the range of mass flow/air content in cooling gas has been evaluated, in which safe core cool down is possible resp. long term core burning occurs; for highest available emergency cooling flow, a safe cool down of the THTR-300, which has no reactor building, is possible for up to 20 vol-% of air in the cooling gas, wheras low flow allows only for about 5 vol-%. If the amount of available air is restricted to the content of a reactor building, as is examined for the PNP-500, relevant consequences have not to be expected; this remains also true for forced convection flow, if burning of CO, formed by graphite oxidation, within the building is considered. For the second accident class examined, air ingress with natural convection flow by chimney draught as studied for the HTR-Modul and some other concepts, the time span until significant fission product release begins has been determined; in case, that the bottom reflector is hot at accident start (> 600 C) and therefore consumes most of the ingressing oxygen, this time span is at least several hours and leak tightening counter measures may be possible. (orig./HP)

  10. Relationship between chloride diffusivity and pore structure of hardened cement paste

    Institute of Scientific and Technical Information of China (English)

    Guo-wen SUN; Wei SUN; Yun-sheng ZHANG; Zhi-yong LIU

    2011-01-01

    Based on effective media theory, a predictive model, relating chloride diffusivity to the capillary pores, gel pores,tortuosity factor, and pore size distribution of hardened cement, is proposed. To verify the proposed model, the diffusion coefficient of chloride ions, the degree of hydration, and peak radius of capillary pores of cement paste specimens were measured. The predicted results for chloride diffusivity were compared with published data. The results showed that the predicted chloride diffusivity of hardened cement paste was in good agreement with the experimental results. The effect of the evolution of pore structures in cement paste on chloride diffusivity could be deduced simultaneously using the proposed model.

  11. The study on water ingress mass in the steam generator heat-exchange tube rupture accident of modular high temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    The steam generator heat-exchange tube rupture (SGTR) accident is an important and particular accident which will result in water ingress to the primary loop of reactor. Water ingress will result in chemical reaction of graphite fuel and structure with water, which may cause overpressure due to generation of explosive gaseous in large quantity. The study on the water ingress accident is significant for the verification of the inherent characteristics of high temperature gas-cooled reactor. The previous research shows that the amount of water ingress mass is the dominant key factor on the severity of the accident consequence. The 200 MWe high temperature gas-cooled reactor (HTR-PM), which is the first modular pebble-bed high temperature gas-cooled reactor in China designed by the Institute of Nuclear and New Energy Technology of Tsinghua University, is selected to be analyzed in this paper. The different DBA accident scenarios of double-ended break of single heat-exchange tube are simulated respectively by the thermal-hydraulic analysis code RETRAN-02. The results show the water ingress mass through the broken heat-exchange tube is related to the break location. The amount of water ingress mass is affected obviously by the capacity of the emptier system. With the balance of safety and economical efficiency, the amount of water ingress mass from the secondary side of steam generator into the primary coolant loop will be reduced by increasing properly the diameter of the draining lines. (authors)

  12. Chloride removal from vitrification offgas

    International Nuclear Information System (INIS)

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

  13. Separate-effect tests on zirconium cladding degradation in air ingress situations

    Energy Technology Data Exchange (ETDEWEB)

    Duriez, C. [Institut de Radioprotection et de Surete Nucleaire, IRSN, Direction de Prevention des Accidents Majeurs, Centre de Cadarache, 13115 St Paul Lez Durance (France)], E-mail: christian.duriez@irsn.fr; Steinbrueck, M. [Forschungszentrum Karlsruhe, FZK, Institut fuer Materialforschung, Postfach 3640, 76021 Karlsruhe (Germany); Ohai, D.; Meleg, T. [Institute for Nuclear Research, INR, Nuclear Material and Corrosion Department, Pitesti, 115400 Mioveni Arges (Romania); Birchley, J.; Haste, T. [Paul Scherrer Institute, 5232 Villigen PSI (Switzerland)

    2009-02-15

    In the event of air ingress during a reactor or spent fuel pond low probability accident, the fuel rods will be exposed to air-containing atmospheres at high temperatures. In comparison with steam, the presence of air is expected to result in a more rapid escalation of the accident. A state-of-the-art review performed before SARNET started showed that the existing data on zirconium alloy oxidation in air were scarce. Moreover, the exact role of zirconium nitride on the cladding degradation process was poorly understood. Regarding the cladding behaviour in air + steam or nitrogen-enriched atmospheres (encountered in oxygen-starved conditions), almost no data were available. New experimental programmes comprising small-scale tests have therefore been launched at FZK, IRSN (MOZART programme in the frame of the International Source Term Program-ISTP) and INR. Zircaloy-4 cladding in PWR (FZK, IRSN) and in CANDU (INR) geometry are investigated. On-line kinetic data are obtained on centimetre size tube segments, by thermogravimetry (FZK, IRSN and INR) or by mass spectrometry (FZK). Plugged tubes 15 cm long (FZK) are also investigated. The samples are air-oxidised either in the 'as-received' state, or after pre-oxidation in steam. 'Analytical' tests at constant temperature and gas composition provide basic kinetic data, while more prototypical temperature transients and sequential gas compositions are also investigated. The temperature domains extend from 600 deg. C up to 1500 deg. C. Systematic post-test metallographic inspections are performed. The paper gives a synthesis of the results obtained, comparing them in terms of kinetics and oxide scale structure and composition. A comparative analysis is performed with results of the QUENCH-10 (Q-10) bundle test, which included an air ingress phase. It is shown how the data contribute to a better understanding of the cladding degradation process, especially regarding the role of nitrogen. For modelling of

  14. Chloride Channels: Often enigmatic, rarely predictable

    Science.gov (United States)

    Duran, Charity; Thompson, Christopher H.; Xiao, Qinghuan; Hartzell, Criss

    2010-01-01

    Until recently, anion (Cl−) channels have received considerably less attention than cation channels. One reason for this may be that many Cl− channels perform functions that might be considered cell biological, like fluid secretion and cell volume regulation, whereas cation channels have historically been associated with cellular excitability that typically happens more rapidly. In this review, we discuss the recent explosion of interest in Cl− channels with special emphasis on new and often surprising developments over the last 5 years. This is exemplified by the findings that more than half of the ClC family members are antiporters, and not channels as was previously thought, and that bestrophins, previously prime candidates for Ca2+-activated Cl− channels, have been supplanted by the newly discovered anoctamins and now hold a tenuous position in the Cl− channel world. PMID:19827947

  15. MiniPanda - a small-scale containment test facility with novel instrumentation is used for code validation for an air ingress scenario

    International Nuclear Information System (INIS)

    “MiniPanda”, a small-scale containment test facility built at ETH Zurich, was equipped with novel field measurement techniques. The capabilities of the facility were demonstrated in a first test series on an air ingress scenario. The ingress of air into a helium cooled reactor is considered to be one of the most severe accidents for the GenIV-type helium cooled reactor. The air once arrived inside the reactor can cause the oxidation of the graphite structures. The ingress of air into a helium environment was investigated experimentally and analytically using the commercial CFX-13 and StarCCM+ 5.06 CFD codes. The experimental volume consists of two cylindrical vessels that are filled separately with air or helium. The experiment is initiated by removing the blockage from the pipe connecting the two vessels. The experimental and analytical results of the consequent buoyancy-driven air ingress are compared against each other. (author)

  16. A role for very-long-chain fatty acids in furrow ingression during cytokinesis in Drosophila spermatocytes

    OpenAIRE

    Szafer-Glusman, Edith; Giansanti, Maria Grazia; Nishihama, Ryuichi; Bolival, Benjamin; Pringle, John; Gatti, Maurizio; Fuller, Margaret T.

    2008-01-01

    Cell shape and membrane remodeling rely on regulated interactions between the lipid bilayer and cytoskeletal arrays at the cell cortex. During cytokinesis, animal cells build an actomyosin ring anchored to the plasma membrane at the equatorial cortex. Ring constriction coupled to plasma membrane ingression separates the two daughter cells [1]. Plasma-membrane lipids influence membrane biophysical properties such as membrane curvature and elasticity and play an active role in cell function [2]...

  17. A mathematical model for electrochemical chloride removal from marine cast iron artifacts

    Institute of Scientific and Technical Information of China (English)

    Weizhen OUYANG; Xia CAO; Ning WANG

    2009-01-01

    The aim of this article was to theoretically study diffusion and migration of chlo-ride ions during electrochemical chloride removal. The proposed model would enable optimization of its application by predicting the optimal treatment time and current combination. A mathematical model for simulating the transport behavior of chloride ions was developed by consideration of diffusion and migration of chloride ions when a constant DC current density was applied through the marine cast iron artifacts. The corresponding tests were conducted to validate the mathematical model. This model predicted the data of the extraction ratio of the chloride ion that correlated satisfac-torily with the experimental values. An important issue in electrochemical chloride removal was to understand how chloride ions moved, taking account of diffusion and migration of chloride ions and the release of binding chloride ions. The effects of the treatment time, externally applied current density, chloride diffusion coefficient, and rate constant of release of binding chloride ion on chloride removal are studied. The specific quantitative details applied to one-dimensional model were discussed here. This article has proposed a mathematical model for the first time, which was showed to be a useful tool that can reveal the ionic transport mechanism and optimize the application during electrochemical chloride removal.

  18. Improvement of TRAC-BF1 code to analyze the Ingress of Coolant Event (ICE)

    International Nuclear Information System (INIS)

    JAERI is performing the Ingress of Coolant Event (ICE) preliminary experiment as one of the technology R and D tasks for the International Thermonuclear Experimental Reactor (ITER). The Transient Reactor Analysis Code (TRAC) was improved and arranged as the ICE experimental analysis code. The TRAC-BF1 code was originally developed for the thermal hydraulics safety analysis of the boiling water reactor (BWR) at the Idaho National Engineering Laboratory (INEL) in USA. We partially modified the code to be applicable for the ICE analysis such as adding the heat transfer model in the VESSEL element plane surface, individual appointment of thermal transfer calculation mesh in VESSEL element. Moreover, the IPLOT program and the GCONV program was introduced to the engineering workstation (EWS) for plotting calculation outputs of TRAC-BF1 code. This paper describes a summary of the improved TRAC-BF1 code, and verification results of the modification of the TRAC-BF1 code, and ICE experimental analyzed result. (author)

  19. Contaminant ingress into multizone buildings: An analytical state-space approach

    KAUST Repository

    Parker, Simon

    2013-08-13

    The ingress of exterior contaminants into buildings is often assessed by treating the building interior as a single well-mixed space. Multizone modelling provides an alternative way of representing buildings that can estimate concentration time series in different internal locations. A state-space approach is adopted to represent the concentration dynamics within multizone buildings. Analysis based on this approach is used to demonstrate that the exposure in every interior location is limited to the exterior exposure in the absence of removal mechanisms. Estimates are also developed for the short term maximum concentration and exposure in a multizone building in response to a step-change in concentration. These have considerable potential for practical use. The analytical development is demonstrated using a simple two-zone building with an inner zone and a range of existing multizone models of residential buildings. Quantitative measures are provided of the standard deviation of concentration and exposure within a range of residential multizone buildings. Ratios of the maximum short term concentrations and exposures to single zone building estimates are also provided for the same buildings. © 2013 Tsinghua University Press and Springer-Verlag Berlin Heidelberg.

  20. Scaling and design analyses of a scaled-down, high-temperature test facility for experimental investigation of the initial stages of a VHTR air-ingress accident

    International Nuclear Information System (INIS)

    A critical event in the safety analysis of the very high-temperature gas-cooled reactor (VHTR) is an air-ingress accident. This accident is initiated, in its worst case scenario, by a double-ended guillotine break of the coaxial cross vessel, which leads to a rapid reactor vessel depressurization. In a VHTR, the reactor vessel is located within a reactor cavity that is filled with air during normal operating conditions. Following the vessel depressurization, the dominant mode of ingress of an air—helium mixture into the reactor vessel will either be molecular diffusion or density-driven stratified flow. The mode of ingress is hypothesized to depend largely on the break conditions of the cross vessel. Since the time scales of these two ingress phenomena differ by orders of magnitude, it is imperative to understand under which conditions each of these mechanisms will dominate in the air ingress process. Computer models have been developed to analyze this type of accident scenario. There are, however, limited experimental data available to understand the phenomenology of the air-ingress accident and to validate these models. Therefore, there is a need to design and construct a scaled-down experimental test facility to simulate the air-ingress accident scenarios and to collect experimental data. The current paper focuses on the analyses performed for the design and operation of a 1/8th geometric scale (by height and diameter), high-temperature test facility. A geometric scaling analysis for the VHTR, a time scale analysis of the air-ingress phenomenon, a transient depressurization analysis of the reactor vessel, a hydraulic similarity analysis of the test facility, a heat transfer characterization of the hot plenum, a power scaling analysis for the reactor system, and a design analysis of the containment vessel are discussed.

  1. Hypoxia-induced alteration of tracer accumulation in cultured cancer cells and xenografts in mice: implications for pre-therapeutic prediction of treatment outcomes with 99mTc-sestamibi, 201Tl chloride and 99mTc-HL91

    International Nuclear Information System (INIS)

    Weak visualization of tumours in pre-therapeutic scintigrams with technetium-99m sestamibi (MIBI) is likely a predictive sign of unfavourable tumour response to radiotherapy and chemotherapy. However, factors relating to this scintigraphic finding are not well understood. The presence of hypoxic tumour cells is one of the major reasons for therapeutic failure; consequently, we attempted to determine whether oxygenation status affects 99mTc-MIBI accumulation in tumour cells. LS180 human colon cancer and T24 human bladder cancer cells were incubated in air or N2 gas at 37 C. Cellular uptake of 99mTc-MIBI was subsequently determined at 15, 60 and 120 min. Uptake of thallium-201 chloride was also assessed. Uptake of 99mTc-HL91 was assessed as a hypoxic marker. Accumulation of the tracers in LS180 xenografts was observed in mice treated with 5 mg/kg hydralazine and compared with that in untreated mice. pO2 in the medium and tumours was measured with O2 microelectrodes. N2 gas flow gradually reduced pO2 in the cell suspension to 1-2 mmHg in 60 min. Cellular uptake of 99mTc-MIBI in LS180 cells decreased by approximately 30% in N2 gas in comparison to that in air throughout the study. Hypoxia had a more prominent influence on 201Tl uptake, which displayed a reduction of approximately 60% in N2 gas at 120 min, than on 99mTc-MIBI uptake. On the other hand, N2 gas induced an increase of 170% in 99mTc-HL91 uptake at 120 min, indicating the hypoxic condition of cells. The results of in vitro assays employing the T24 cell line were similar to those obtained with the LS180 cell line. Hydralazine treatment markedly reduced 99mTc-MIBI and 201Tl accumulation in LS180 xenografts; moreover, intratumoural pO2 decreased from 14.5±6.6 mmHg to 7.6±6.2 mmHg. 99mTc-HL91 accumulation in xenografts was markedly increased by hydralazine. In conclusion, hypoxia reduced accumulation of 99mTc-MIBI and 201Tl in tumour cells. Accordingly, hypoxia may be an important factor in terms of the

  2. [Degradation of succinylcholine chloride].

    Science.gov (United States)

    Németh, G; Török, I; Paál, T

    1993-05-01

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

  3. Analysis on blow-down transient in water ingress accident of high temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    Water ingress into the primary circuit is generally recognized as one of the severe accidents with potential hazard to the modular high temperature gas-cooled reactor, which will cause a positive reactivity introduction with the increase of steam density in reactor core to enhance neutron slowing-down, also the chemical corrosion of graphite fuel elements and the damage of reflector structure material. The increase of the primary pressure may result in the opening of the safety valves, consequently leading the release of radioactive isotopes and flammable water gas. The research on water ingress transient is significant for the verification of inherent safety characteristics of high temperature gas-cooled reactor. The 200 MWe high temperature gas-cooled reactor (HTR-PM), designed by the Institute of Nuclear and New Energy Technology of Tsinghua University, is exampled to be analyzed in this paper. The design basis accident (DBA) scenarios of double-ended guillotine break of single heat-exchange tube (steam generator heat-exchange tube rupture) are simulated by the thermal-hydraulic analysis code, and some key concerns which are relative to the amount of water into the reactor core during the blow-down transient are analyzed in detail. The results show that both of water mass and steam ratio of the fluid spouting from the broken heat-exchange tube are affected by break location, which will increase obviously with the broken location closing to the outlet of the heat-exchange tube. The double-ended guillotine rupture at the outlet of the heat-exchange will result more steam penetrates into the reactor core in the design basis accident of water ingress. The mass of water ingress will also be affected by the draining system. It is concluded that, with reasonable optimization on design to balance safety and economy, the total mass of water ingress into the primary circuit of reactor could be limited effectively to meet the safety requirements, and the pollution of

  4. FY-09 Report: Experimental Validation of Stratified Flow Phenomena, Graphite Oxidation, and Mitigation Strategies of Air Ingress Accidents

    Energy Technology Data Exchange (ETDEWEB)

    Chang H. Oh; Eung S. Kim

    2009-12-01

    The Idaho National Laboratory (INL), under the auspices of the U.S. Department of Energy, is performing research and development that focuses on key phenomena important during potential scenarios that may occur in the Next Generation Nuclear Plant (NGNP)/Gen-IV very high temperature reactor (VHTR). Phenomena Identification and Ranking Studies to date have identified that an air ingress event following on the heels of a VHTR depressurization is a very important incident. Consequently, the development of advanced air ingress-related models and verification and validation data are a very high priority for the NGNP Project. Following a loss of coolant and system depressurization incident, air will enter the core through the break, leading to oxidation of the in-core graphite structure and fuel. If this accident occurs, the oxidation will accelerate heat-up of the bottom reflector and the reactor core and will eventually cause the release of fission products. The potential collapse of the core bottom structures causing the release of CO and fission products is one of the concerns. Therefore, experimental validation with the analytical model and computational fluid dynamic (CFD) model developed in this study is very important. Estimating the proper safety margin will require experimental data and tools, including accurate multidimensional thermal-hydraulic and reactor physics models, a burn-off model, and a fracture model. It will also require effective strategies to mitigate the effects of oxidation. The results from this research will provide crucial inputs to the INL NGNP/VHTR Methods Research and Development project. The second year of this three-year project (FY-08 to FY-10) was focused on (a) the analytical, CFD, and experimental study of air ingress caused by density-driven, stratified, countercurrent flow; (b) advanced graphite oxidation experiments and modeling; (c) experimental study of burn-off in the core bottom structures, (d) implementation of advanced

  5. Prediction

    OpenAIRE

    Woollard, W.J.

    2006-01-01

    In this chapter we will look at the ways in which you can use ICT in the classroom to support hypothesis and prediction and how modern technology is enabling: pattern seeking, extrapolation and interpolation to meet the challenges of the information explosion of the 21st century.

  6. Durability predictions from rate of diffusion testing of normal portland cement, fly ash, and slag concrete

    International Nuclear Information System (INIS)

    A waste repository for the belowground disposal of low-level radioactive waste, labelled IRUS (Intrusion Resistant Underground Structure), is planned at the Chalk River Laboratories. It relies greatly on the durability of concrete for a minimum of 500 years of service life. A research program based on laboratory testing to design a durable concrete and predict its useful engineered service life is in progress. The durability of concrete depends on its resistance to deterioration from both internal and external causes. Since the rate of degradation depends to a major extent on the rate of ingress of aggressive ions into concrete, laboratory testing is in progress to establish the diffusion rates of chlorides and sulphate ions. A total of 1000 concrete specimens and 500 paste specimens are being exposed at 22 degrees and 45 degrees C to twenty-five different combinations of corrosive agents, including CO2. Procedures to measure the ionic penetration profile and to determine the factors controlling diffusion of ions in the various concretes have been developed. The paper presents the initial results from the research program and the longevity predictions to qualify concretes for the IRUS waste repository, based on 16 months of diffusion testing on laboratory specimens

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

    Science.gov (United States)

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

  8. Prediction

    CERN Document Server

    Sornette, Didier

    2010-01-01

    This chapter first presents a rather personal view of some different aspects of predictability, going in crescendo from simple linear systems to high-dimensional nonlinear systems with stochastic forcing, which exhibit emergent properties such as phase transitions and regime shifts. Then, a detailed correspondence between the phenomenology of earthquakes, financial crashes and epileptic seizures is offered. The presented statistical evidence provides the substance of a general phase diagram for understanding the many facets of the spatio-temporal organization of these systems. A key insight is to organize the evidence and mechanisms in terms of two summarizing measures: (i) amplitude of disorder or heterogeneity in the system and (ii) level of coupling or interaction strength among the system's components. On the basis of the recently identified remarkable correspondence between earthquakes and seizures, we present detailed information on a class of stochastic point processes that has been found to be particu...

  9. Oxidation kinetics of innovative carbon materials with respect to severe air ingress accidents in HTRs and graphite disposal or processing

    International Nuclear Information System (INIS)

    Currently future nuclear reactor concepts of the Fourth Generation (Gen IV) are under development. To some extend they apply with new, innovative materials developed just for this purpose. This thesis work aims at a concept of Generation IV Very High Temperature Reactors (VHTR) in the framework of the European project RAPHAEL (ReActor for Process heat, Hydrogen And ELectricity generation). The concept named ANTARES (AREVA New Technology based on advanced gas-cooled Reactors for Energy Supply) was developed by AEVA NP. It is a helium cooled, graphite moderated modular reactor for electricity and hydrogen production, by providing the necessary process heat due to its high working temperature. Particular attention is given here to oxidation kinetics of newly developed carbon materials (NBG-17) with still unknown but needed information in context of severe air ingress accident in VHTR's. Special interest is paid to the Boudouard reaction, the oxidation of carbon by CO2. In case of an air ingress accident, carbon dioxide is produced in the primary reaction of atmospheric oxygen with reflector graphite. From there CO2 could flow into the reactor core causing further damage by conversion into CO. The purpose of this thesis is to ascertain if and to what degree this could happen. First of all oxidation kinetic data of the Boudouard reaction with NBG-17 is determined by experiments in a thermo gravimetric facility. The measurements are evaluated and converted into a common formula and a Langmuir-Hinshelwood similar oxidation kinetic equation, as input for the computer code REACT/THERMIX. This code is then applied to analyse severe air ingress accidents for several air flow rates. The results are discussed for two accident situations, in which a certain graphite burn off is achieved. All cases show much more damage to the graphite bottom reflector than to the reactor core. Thus the bottom reflector will lose its structural integrity much earlier than the core itself will be

  10. Valyl benzyl ester chloride

    Directory of Open Access Journals (Sweden)

    Grzegorz Dutkiewicz

    2010-02-01

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

  11. Pharmaceutical container/closure integrity. IV: Development of an indirect correlation between vacuum decay leak measurement and microbial ingress.

    Science.gov (United States)

    Nguyen, L T; Muangsiri, W; Schiere, R; Guazzo, D K; Kirsch, L E

    1999-01-01

    The rational development of a physical test method to evaluate the microbial barrier properties of sterile containers necessitates its correlation to microbiological exclusion. This can be accomplished by direct or indirect correlation. In the former, the proposed physical test is directly compared to microbial challenges using appropriate test units that stimulate container leaks at both high and low probabilities of microbial ingress. Previous work has demonstrated the development of a direct correlation using helium leak rate methods and microbial immersion challenges. An indirect correlation can be established by comparing the proposed physical method to well-defined leakage standards that represent various known levels of microbial ingress. Thus the quality assurance properties of a physical test method can be established by comparison to another physical test method that has been previously characterized. This approach has the distinct advantages of being faster, quantitatively rigorous, and less subject to the vicissitudes, of microbial testing. This approach was demonstrated by comparing the helium leak rate method to vacuum decay testing. Additionally it was demonstrated that vacuum decay testing was a fast and reproducible method for detecting leaks of about 1 to 2 mm. Leaks were simulated by affixing micropipettes into glass vials. PMID:10754714

  12. Possibility of air ingress into a BWR containment during a LOCA in case of activation of containment venting system

    International Nuclear Information System (INIS)

    The pressure relief systems installed in BWRs protect the containment from overpressure in case of a Loss of Coolant Accident (LOCA). This paper analyzes the possibility of air ingress, which can cause hydrogen burn, through the rupture disks of the filtered and non-filtered venting systems. Two scenarios were considered: a LOCA without SBO (Station Blackout) and a LOCA with SBO. The thermal-hydraulic code GOTHIC® was used with 3D models of the drywell and wetwell of a Nordic-type BWR. In the LOCA event, we found no activation of the rupture disks within the considered transient simulation. Moreover, the containment spray ensured a low pressure in the drywell and induced a continuous mixing of the wetwell pool. In the LOCA with SBO event, the development of thermal stratification in the wetwell pool accelerated the pressure increase in the drywell, which led to activation of the rupture disk of the filtered venting system. However, no air ingress through the vent was found during the depressurization of the containment, and hence no risk of hydrogen burn under the given assumptions. (author)

  13. Thermodynamic calculation of self-diffusion in sodium chloride

    Science.gov (United States)

    Zhang, Baohua; Li, Chengbo; Shan, Shuangming

    2016-05-01

    Using the available pressure-volume-temperature equation of state of sodium chloride, we show that the self-diffusion coefficients of sodium and chloride in sodium chloride as a function of temperature and pressure can be successfully reproduced in terms of bulk elastic and expansivity data. We use a thermodynamic model that interconnects point-defect parameters with bulk properties. Our calculated diffusion coefficients and point-defect parameters, including activation enthalpy, activation entropy, and activation volume, well agree with reported experimental results when uncertainties are considered. Furthermore, the ionic conductivity of sodium chloride inferred from our predicted diffusivities of sodium through the Nernst-Einstein equation is compared with previous experimental data.

  14. In-reactor Hydrogen/Deuterium ingress in Zr-2.5Nb pressure tubes and their measurement in sliver metallic samples

    International Nuclear Information System (INIS)

    Deuterium (D)/Hydrogen (H) ingress in pressure tubes (PTs) of operating PHWRs beyond solubility limit will lead to deuteride/hydride precipitation and may result in delayed hydride cracking. In-reactor H/D ingress in PTs, is periodically monitored by measuring the H/D-content in the sliver metallic samples scraped from selected PTs during their service life. This paper describes some radio analytical works on sliver samples from PTs of some of the reactors of Nuclear Power Corporation of India Limited (NPCIL). (author)

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

    OpenAIRE

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

    1993-01-01

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

  16. Small-Scale Water Ingression and Crust Strength Tests (SSWICS) SSWICS-6 test data report : thermal hydraulic results, Rev. 0.

    Energy Technology Data Exchange (ETDEWEB)

    Lomperski, S.; Farmer, M. T.; Kilsdonk, D.; Aeschlimann, B. (Nuclear Engineering Division)

    2011-06-28

    The Melt Attack and Coolability Experiments (MACE) program at Argonne National Laboratory addressed the issue of the ability of water to cool and thermally stabilize a molten core/concrete interaction (MCCI) when the reactants are flooded from above. These tests provided data regarding the nature of corium interactions with concrete, the heat transfer rates from the melt to the overlying water pool, and the role of noncondensable gases in the mixing processes that contribute to melt quenching. However, due to the integral nature of these tests, several questions regarding the crust freezing behavior could not be adequately resolved. These questions include: (1) To what extent does water ingression into the crust increase the melt quench rate above the conduction-limited rate and how is this affected by melt composition and system pressure? (2) What is the fracture strength of the corium crust when subjected to a thermal-mechanical load and how does it depend upon the melt composition? A series of separate-effects experiments are being conducted to address these issues. The first employs an apparatus designed to measure the quench rate of a pool of corium ({approx} {phi} 30 cm; up to 20 cm deep). The main parameter to be varied in these quench tests is the melt composition since it is thought to have a critical influence on the crust cracking behavior which, in turn, alters quench rate. The issue of crust strength is being addressed with a second apparatus designed to mechanically load the crust produced by the quench tests. This apparatus measures the fracture strength of the crust while it is either at room temperature or above, the latter state being achieved with a heating element placed below the crust. The two apparatuses used to measure the melt quench rate and crust strength are jointly referred to as SSWICS (Small-Scale Water Ingression and Crust Strength). This report describes results of the sixth water ingression test, designated SSWICS-6. This test

  17. Small-Scale Water Ingression and Crust Strength Tests (SSWICS) SSWICS-6 test data report: thermal hydraulic results, Rev. 0

    International Nuclear Information System (INIS)

    The Melt Attack and Coolability Experiments (MACE) program at Argonne National Laboratory addressed the issue of the ability of water to cool and thermally stabilize a molten core/concrete interaction (MCCI) when the reactants are flooded from above. These tests provided data regarding the nature of corium interactions with concrete, the heat transfer rates from the melt to the overlying water pool, and the role of noncondensable gases in the mixing processes that contribute to melt quenching. However, due to the integral nature of these tests, several questions regarding the crust freezing behavior could not be adequately resolved. These questions include: (1) To what extent does water ingression into the crust increase the melt quench rate above the conduction-limited rate and how is this affected by melt composition and system pressure? (2) What is the fracture strength of the corium crust when subjected to a thermal-mechanical load and how does it depend upon the melt composition? A series of separate-effects experiments are being conducted to address these issues. The first employs an apparatus designed to measure the quench rate of a pool of corium (∼ φ 30 cm; up to 20 cm deep). The main parameter to be varied in these quench tests is the melt composition since it is thought to have a critical influence on the crust cracking behavior which, in turn, alters quench rate. The issue of crust strength is being addressed with a second apparatus designed to mechanically load the crust produced by the quench tests. This apparatus measures the fracture strength of the crust while it is either at room temperature or above, the latter state being achieved with a heating element placed below the crust. The two apparatuses used to measure the melt quench rate and crust strength are jointly referred to as SSWICS (Small-Scale Water Ingression and Crust Strength). This report describes results of the sixth water ingression test, designated SSWICS-6. This test investigated

  18. Chloride channels in stroke

    Institute of Scientific and Technical Information of China (English)

    Ya-ping ZHANG; Hao ZHANG; Dayue Darrel DUAN

    2013-01-01

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

  19. Analysis of diffusion process and influence factors in the air ingress accident of the HTR-PM

    International Nuclear Information System (INIS)

    Air ingress, one of the beyond design basis accidents for high temperature gas-cooled reactors, receives high attention during the design of the 250 MW pebble-bed modular high temperature gas-cooled reactor (HTR-PM), because it may result in severe consequence including the corrosion of the fuel element and graphite reflector. The diffusion process and the set-up time of the stable natural convection after the double-ended guillotine break of the hot-gas duct are studied in the paper. On the basis of the preliminary design of the HTR-PM and its DLOCA analysis results, the diffusion process, as well as the influence of the core temperature distribution and the length of the hot-gas duct, is studied with the DIFFLOW code, which adopts a one-dimension variable cross-section diffusion model with fixed wall temperature. To preliminarily estimate the influence of chemical reaction between oxygen and graphite, which will change the gas component of the mixture, the diffusion processes between the He/N2, He/O2, He/CO and He/CO2 are calculated, respectively. Furthermore, the code has been improved and the varying wall temperature can be simulated. The more accurate analysis is carried out with the changing temperature distribution from the DLOCA calculation. The analysis shows that there is enough time to adopt appropriate mitigation measures to stop the air ingress and the severe consequence of fuel element damage and large release of fission product can be avoided

  20. Numerical assessment of non-uniform corrosion scenarios of rebar in concrete exposed to natural chloride environment

    Indian Academy of Sciences (India)

    S Muthulingam; B N Rao

    2015-06-01

    Corrosion of embedded rebars is a classical deterioration mechanism that remains as one of the most significant problems limiting the service life of concrete structures exposed to chloride-laden environments. The primary objective of this study is to propose and verify a numerical framework that can efficiently quantify non-uniform corrosion penetration depth along the perimeter of the rebar in concrete exposed to chloride environment. This framework investigates the corrosion process during both the corrosion initiation and propagation phases by exploring the effects of not only the rebar existence but also its sizes and locations. The corrosion initiation phase is examined through a comprehensive chloride ingress model that identifies the most important parameters that influence the intrusion of chlorides into RC. The corrosion propagation phase is studied based on a decisive parameter, namely, the corrosion rate. In addition, the framework evaluates the non-uniform corrosion states that correspond to two scenarios of corrosion penetration depth: corrosion of segment of the rebar and uneven corrosion along the rebar perimeter. Numerical solution shows that, in general, chloride build-up along the perimeter of the corner bar is not only faster but also higher than that of the middle bar. Moreover, for the given values of cover thickness and water-to-binder ratio, time-to-corrosion initiation for the corner bar is faster than that for the middle bar. Furthermore, the larger the rebar, in general, the bigger the obstruction, and therefore, the higher the chloride build-up. Qualitative comparisons of the evaluated non-uniform corrosion scenarios with the variety of available laboratory and field data show good agreement.

  1. Stochastic Models for Chloride-Initiated Corrosion in Reinforced Concrete

    DEFF Research Database (Denmark)

    Engelund, S.; Sørensen, John Dalsgaard

    Corrosion of the reinforcement in concrete structures can lead to a substantial decrease of the load-bearing capacity. One mode of corrosion initiation is when the chloride content around the reinforcement exceeds a threshold value. In the present paper a statistical model is developed by which the...... chloride content in a reinforced concrete structure can be predicted. The model parameters are estimated on the basis of measurements. The distribution of the time to initiation of corrosion is estimated by FORM/SORM-analysis....

  2. Chloride in vesicular trafficking and function.

    Science.gov (United States)

    Stauber, Tobias; Jentsch, Thomas J

    2013-01-01

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

  3. Stability of succinylcholine chloride injection.

    Science.gov (United States)

    Schmutz, C W; Mühlebach, S F

    1991-03-01

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

  4. Chloride binding of cement-based materials subjected to external chloride environment - A review

    OpenAIRE

    Yuan, Q.; Shi, C; Schutter, G. de; Audenaert, K.; Deng, D.

    2009-01-01

    This paper reviews the chloride binding of cement-based materials subjected to external chloride environments. Chloride ion exist either in the pore solution, chemically bound to the hydration products, or physically held to the surface of the hydration products. Chloride binding of cement-based material is very complicated and influenced by many factors, such as chloride concentration, cement composition, hydroxyl concentration, cation of chloride salt, temperature, supplementary cementing m...

  5. OECD MCCI Small-Scale Water Ingression and Crust Strength tests (SSWICS) design report, Rev. 2 October 31, 2002.

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, M.; Lomperski, S.; Kilsdonk, D.; Aeschlimann, B.; Pfeiffer, P. (Nuclear Engineering Division); (NRC)

    2011-05-23

    The Melt Attack and Coolability Experiments (MACE) program at Argonne National Laboratory addressed the issue of the ability of water to cool and thermally stabilize a molten core/concrete interaction (MCCI) when the reactants are flooded from above. These tests provided data regarding the nature of corium interactions with concrete, the heat transfer rates from the melt to the overlying water pool, and the role of noncondensable gases in the mixing processes that contribute to melt quenching. However, due to the integral nature of these tests, several questions regarding the crust freezing behavior could not be adequately resolved. These questions include: (1) To what extent does water ingression into the crust increase the melt quench rate above the conduction-limited rate and how is this affected by melt composition and system pressure and (2) What is the fracture strength of the corium crust when subjected to a thermal-mechanical load and how does it depend upon the melt composition? A series of separate-effects experiments are planned to address these issues. The first employs an apparatus designed to measure the quench rate of a pool of corium ({approx}{phi}30 cm; up to 20 cm deep). The main parameter to be varied in these quench tests is the melt composition since it is thought to have a critical influence on the crust cracking behavior which, in turn, alters quench rate. A description of the test apparatus, instrumentation, data reduction, and test matrix are the subject of the first portion of this report. The issue of crust strength will be addressed with a second apparatus designed to mechanically load the crust produced by the quench tests. This apparatus will measure the fracture strength of the crust while under a thermal load created by a heating element beneath the crust. The introduction of a thermal gradient across the crust is thought to be important for these tests because of uncertainty in the magnitude of the thermal stresses and thus their

  6. 1,5-Diaminotetrazolium chloride

    Directory of Open Access Journals (Sweden)

    Ling-Qiao Meng

    2010-04-01

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

  7. Dynamic [Cl{sup -}]{sub i} measurement with chloride sensing quantum dots nanosensor in epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Wang Yuchi; Mao Hua; Wong, Lid B, E-mail: ywang@biotechplex.com [BioTechPlex Corporation, 1205 Linda Vista Drive Suite A, San Marcos, CA 92078 (United States); Cytoptics Corporation, 1205 Linda Vista Drive Suite B, San Marcos, CA 92078 (United States)

    2010-02-05

    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{sup -}]{sub 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{sup -}]{sub 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{sup -}]{sub 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{sup -}]{sub i}. These are the first data in using QD-based chloride ion sensors for dynamic measurements of intracellular chloride ion concentrations in epithelial cells.

  8. Effects of Implant Design Parameters on Fluid Convection, Potentiating 3rd Body Debris Ingress into the Bearing Surface during THA Impingement/Subluxation

    OpenAIRE

    Lundberg, Hannah J.; Pedersen, Douglas R.; Baer, Thomas E.; Muste, Marian; Callaghan, John J.; Brown, Thomas D.

    2007-01-01

    Aseptic loosening from polyethylene wear debris is the leading cause of failure for metal-on-polyethylene total hip implants. Third body debris ingress to the bearing space results in femoral head roughening and acceleration of polyethylene wear. How third body particles manage to enter the bearing space between the closely conforming articulating surfaces of the joint is not well understood. We hypothesize that one such mechanism is from convective fluid transport during subluxation of the t...

  9. Numerical simulation of the gas diffusion process during an air ingress accident in the HTR-PM

    International Nuclear Information System (INIS)

    The consequence of an air ingress accident can be greatly influenced by the gas-diffusion process. It is necessary to study the process of air diffusion in the cavity of the reactor through the rupture of hot gas ducts of the High Temperature Gas-cooled Reactor Pebble-bed Module (HTR-PM) until steady convection forms. The DIFFLOW code was used for the numerical simulation that illustrated the gas-diffusion process inside of the HTR-PM. In the sensitivity analysis, the core temperature, the diffusion coefficient, the frictional resistance coefficient and the surface coefficient of heat transfer proved to be the impact factors. Each factor was evaluated with three levels. The onset time of the steady convection, the velocity in the middle passage under steady convection, and the mass flow in the middle passage under steady convection were observed in the analysis. 32.78 hours after the accident occurs, the steady convection could be established. The flow in the middle passage under steady convection measured 0.32kg/s, while the velocity in the middle passage read 0.56m/s. The sensitivity analysis also showed that the core temperature had a remarkable impact on the onset time, the velocity and the flow of the steady convection. (author)

  10. Chloride sublimation of gold-arsenic concentrates

    International Nuclear Information System (INIS)

    Present article is devoted to chloride sublimation of gold-arsenic concentrates. The results of studies of chloride sublimation of gold-arsenic comprising concentrates of Chore deposit of Tajikistan are considered. It is found that by application sodium chloride for gold-arsenic comprising concentrates it is possible to extract gold and silver from flotation concentrates.

  11. 21 CFR 582.5446 - Manganese chloride.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Manganese chloride. 582.5446 Section 582.5446 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5446 Manganese chloride. (a) Product. Manganese chloride. (b) Conditions of use....

  12. Sulfate ingress and steam generator hideout at Saint Lucie Unit 1

    International Nuclear Information System (INIS)

    In March 1989, Florida Power and Light Company contracted with NUS Corporation to perform a secondary cycle mass balance study at the St. Lucie 1 Plant. St. Lucie Unit 1 has shown significant steam generator intergranular attack (IGA) since startup in 1974 in contrast to Unit 2 which has shown no significant problems since startup in 1978. Based on a number of evaluations including tube examinations, MULTEQ predictions, and cation/anion balances, acid sulfate induced IGA is suspected as the mechanism of attack by the FP ampersand L staff. The primary purpose of the NUS study was to attempt to identify a possible source or sources of sulfate by conducting mass balance determinations under various modes of plant operation. A secondary purpose was to compare impurity hideout data obtained under steady-state operating conditions using improved ion chromatography techniques with data previously reported by NWT Corporation using a feedwater spiking procedure. 18 refs., 29 figs., 27 tabs

  13. Perfluorocarbon Tracer Experiments on a 2 km Scale in Manchester Showing Ingress of Pollutants into a Building

    Science.gov (United States)

    Matthews, James; Wright, Matthew; Bacak, Asan; Silva, Hugo; Priestley, Michael; Martin, Damien; Percival, Carl; Shallcross, Dudley

    2016-04-01

    Cyclic perfluorocarbons (PFCs) have been used to measure the passage of air in urban and rural settings as they are chemically inert, non-toxic and have low background concentrations. The use of pre-concentrators and chemical ionisation gas chromatography enables concentrations of a few parts per quadrillion (ppq) to be measured in bag samples. Three PFC tracers were used in Manchester, UK in the summer of 2015 to map airflow in the city and ingress into buildings: perfluomethylcyclohexane (PMCH), perfluoro-2-4-dimethylcyclohexane (mPDMCH) and perfluoro-2-methyl-3-ethylpentene (PMEP). A known quantity of each PFC was released for 15 minutes from steel canisters using pre-prepared PFC mixtures. Release points were chosen to be upwind of the central sampling location (Simon Building, University of Manchester) and varied in distance up to 2.2 km. Six releases using one or three tracers in different configurations and under different conditions were undertaken in the summer. Three further experiments were conducted in the Autumn, to more closely investigate the rate of ingress and decay of tracer indoors. In each experiment, 10 litre samples were made over 30 minutes into Tedlar bags, starting at the same time the as PFC release. Samples were taken in 11 locations chosen from 15 identified areas including three in public parks, three outside within the University of Manchester area, seven inside and five outside of the Simon building and two outside a building nearby. For building measurements, receptors were placed inside the buildings on different floors; outside measurements were achieved through a sample line out of the window. Three of the sample positions inside the Simon building were paired with samplers outside to allow indoor-outdoor comparisons. PFC concentrations varied depending on location and height. The highest measured concentrations occurred when the tracer was released at sunrise; up to 330 ppq above background (11 ppq) of PMCH was measured at the 6

  14. Isotopic measurements in research on seawater ingression in the carbonate aquifer of the Salentine Peninsula, Southern Italy

    International Nuclear Information System (INIS)

    Cretaceous calcareous and dolomitic rocks, bedded, jointed and karstified, and hence generally very permeable, form the basement of the Salentine Peninsula. These rocks constitute a huge aquifer with fresh and brackish groundwaters that float on groundwaters of marine origin. Sea level constitutes the base level of the ground waters. A basic outline is first given of the hydrogeology and the paleohydrogeology, so as to provide the necessary background information on the seawater intrusion phenomenon and to permit comparison of the results of the isotope data with those obtained by the classical methods of hydrogeological investigation. This is followed by presentation of the results of the isotopic measurements on 18O, D, 13C and 14C. The δ13C contents indicate, in good agreement with the carbon dioxide and bicarbonate concentrations, that seawater ingression leads to the migration of carbon dioxide from the fresh and brackish waters towards the subjacent intrusive waters of marine origin. Along those stretches of coast where the seawaters are in direct communication with the groundwaters, all the isotope data point to very active renewal of groundwaters of marine origin by seawater. In the central parts of the peninsula and along those stretches of coast where direct communication between seawaters and groundwaters is impeded by impervious clays, the 14C contents indicate that the seawater intrusion and consequently the migration of carbon dioxide are either very slow and continuous in time or that they occurred relatively rapidly in the past. Taking into consideration the paleohydrogeology of the peninsula, and the fact that the δ18O and δD values are higher than those of the present seawaters, leads to the belief that seawater intrusion may well have occurred during major variations in the sea level in the past, when climatic conditions were different from those now prevailing. (author)

  15. Neutron diffraction study of aluminum chloride imidazolium chloride molten salts

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, S. [Nisshin Steel Co. Ltd., Tokyo (Japan); Saboungi, M.L.; Suzuya, K. [Argonne National Lab., IL (United States); Koura, N. [Tokyo University of Science, Tokyo (Japan). Faculty of Science and Technology

    1994-02-01

    The structure of molten mixtures of (AlCl{sub 3}){sub x}(1-ethyl-3-methylimidazolium chloride){sub 1-x} was investigated by neutron diffraction techniques for x=0.46, 0.50, 0.60 and 0.67. Results derived from earlier ab initio molecular orbital (6-31G* basis set) computations for AlCl{sub 4}{sup {minus}}, Al{sub 2}Cl{sub 7}{sup {minus}}, and EMI{sup +} were used to calculate the diffraction patterns; the calculated contributions of each species are thus obtained and overall results are in good agreement with measurements.

  16. Factors other than chloride level influencing rate of reinforcement

    Energy Technology Data Exchange (ETDEWEB)

    Castel, A.; Arliguie, G. [Paul Sabatier Univ., Toulouse (France); Francois, R. [Institut National Des Sciences Appliques, Toulouse (France)

    2000-07-01

    To evaluate the degree of corrosion a 14 year-old concrete member was completely bared and three meter-long beams were stored in three-point flexion in an aggressive environment by sequences of drying and wetting by a salt fog. Total chloride content was measured at the level of all reinforcements. Despite the small concrete cover of 10 mm at the stirrups and 16 mm for the longitudinal reinforcement, no evidence was found to relate corrosion to chloride content, since a large part of the reinforcement was not affected by corrosion. It was concluded that the steel-concrete interface had a major influence on being able to predict the onset of corrosion in relation to chloride content. Indeed, corrosion damage was only present when the steel-concrete interface was damaged. These results call into question the validity of the chloride threshold as the single determining criterion to forecast corrosion development. It is suggested that the nature of the interface between steel and concrete, which may be randomly distributed along the reinforcements, should also be considered. Experimental evidence shows that steel-concrete interface damage is linked to non-elastic behaviour of bond that occurs at a given level of mechanical loading. Therefore, corrosion damage is best considered as a deterministic phenomenon linked to a bonding damage. 25 refs., 2 tabs., 10 figs.

  17. Theoretical Study of the Kinetics of the Pyrolytic Elimination Reaction of Ethyl Chloride

    OpenAIRE

    Isaiah Ajibade Adejoro; Emmanuel Ekeh

    2010-01-01

    The products of the gas-phase elimination of ethyl chloride are hydrogen chloride and ethane. Using AM1, MNDO and PM3 Hamiltonians of quantum mechanical computer code called MOPAC, a procedure for the kinetics and computation of the Arrhenius parameters for the pyrolytic elimination reaction of ethyl chloride was devised in order to evaluate the predictive ability of the three Hamiltonians used. The first-order rate coefficient for the three Hamiltonians are 1.15x10-8s-1, 4.55x10-15s-1 and 5....

  18. Synthesis of Zirconium Lower Chlorides

    International Nuclear Information System (INIS)

    This research is accurately related to the Halox concept of research reactor spent fuel element treatment.The aim of this project is to work the conditioning through selected chlorination of the element that make the spent fuel element. This research studied the physical chemistry conditions which produce formation of the lower zirconium chlorides through the reaction between metallic Zr and gaseous ZrCl4 in a silica reactor.This work focused special attention in the analysis and confrontation of the published results among the different authors in order to reveal coincidences and contradictions.Experimental section consisted in a set of synthesis with different reaction conditions and reactor design. After reaction were analyzed the products on Zr shavings and the deposit growth on wall reactor.The products were strongly dependent of reactor design. It was observed that as the distance between Zr and wall reactor increased greater was tendency to lower chlorides formation.In reactors with small distance the reaction follows other way without formation of lower chlorides.Analysis on deposit growth on reactor showed that may be formed to a mixture of SixZry intermetallics and zirconium oxides.Presence of oxygen in Zr and Zr-Si compounds on wall reactor reveals that there is an interaction between quartz and reactants.This interaction is in gaseous phase because contamination is observed in experiences where Zr was not in contact with reactor.Finally, it was made a global analysis of all experiences and a possible mechanism that interprets reaction ways is proposed

  19. A Thermo-Hygro-Coupled Model for Chloride Penetration in Concrete Structures

    OpenAIRE

    Nattapong Damrongwiriyanupap; Suchart Limkatanyu; Yunping Xi

    2015-01-01

    Corrosion damage due to chloride attack is one of the most concerning issues for long term durability of reinforced concrete structures. By developing the reliable mathematical model of chloride penetration into concrete structures, it can help structural engineers and management agencies with predicting the service life of reinforced concrete structures in order to effectively schedule the maintenance, repair, and rehabilitation program. This paper presents a theoretical and computational mo...

  20. Cooper hydrometallurgy and extraction from chloride media

    International Nuclear Information System (INIS)

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

  1. Modeling of Multi-Layered Protection Systems for Chloride Penetration in Concrete Bridge Decks

    Science.gov (United States)

    Harajli, Ali A.

    Modeling of Multi-Layered Protection Systems for Chloride Penetration in Concrete Bridge Decks. This paper covers the development of a new methodology for predicting the chloride concentration and corrosion initiation times for a multi-layer protection overlay system. The first topic will be presenting an innovative method to predict the chloride concentrations using different diffusion coefficients for each protective layer. The new method covers the cases where the applied surface chloride concentrations are either a constant or linear functions with time. The second topic will implement the results from field data about the chloride variations due to the presence of applied topical layers for comparison with the theoretical models. This section will also apply damage factors that are time-dependent to simulate external factors such as traffic loading or vibrations. The third topic will investigate the sensitivity of the single and multi-layer systems due to diffusivity parameter changes. The fourth topic will analyze the random variation of the diffusivity values to predict the mean and standard deviation of chloride concentrations. The diffusivity values are selected from published values by NIST and are based on certain water cement (w/c) ratios.

  2. Dechlorinating reaction of organic chlorides

    International Nuclear Information System (INIS)

    Dechlorination has been examined by the reaction between iron, aluminum powder or CaO and organic chlorides such as C2HCl3 and CH2Cl2. Progress of the reaction was analyzed with mass spectrometer. The reaction between iron and organic chloride was rapidly occurred at the temperature between 350 and 440degC in an atmosphere of argon. Above 380degC, more than 99.5% of C2HCl3 was decomposed within approximately 100 minutes. At 440degC, approximately 60% of C2HCl3 was decomposed by the reaction with aluminium powder within approximately 100 minutes. At 440degC, reaction between C2HCl3 and CaO powder were occurred rapidly in an atmosphere of argon to form CaCl2 and free carbon. Also in an atmosphere of air, nearly the same result was obtained. In this reaction, CaCl2, CO and CO2 were formed. CH2Cl2 was also decomposed by the reaction with iron at the temperature between 380 and 440degC. In the reaction, FeCl2, carbon and hydrogen were formed. CH3+ and CH4 were observed during the dechlorinating reaction of CH2Cl2. Variation in particle size of iron powder such as 100, 150 and 250 mesh did not affect the reaction rate. (author)

  3. Method of processing chloride waste

    International Nuclear Information System (INIS)

    In a method of applying molten salt electrolysis to chloride wastes discharged from a electrolytic refining step of a dry reprocessing step for spent fuels, and removed with transuranium elements of long half-decaying time, metals capable of alloying with alkali and alkaline earth metals under melting by electrolysis are used as a cathode material, and an electrolytic temperature is made higher than the melting point of salts in a molten salt electrolysis bath, to recover Li, Ca and Na as alloys with the cathode material in a first electrolysis step. Then, the electrolytic temperature is made higher than the melting point of the chloride salts remained in the bath after the electrolysis step described above by using the cathode material, to recover Ba, Rb, Sr and Cs of nuclear fission products also as alloys with the cathode material in a second electrolysis step. Accordingly, the amount of wastes formed can be reduced, and the wastes contain no heat generating nuclear fission elements. (T.M.)

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

    Institute of Scientific and Technical Information of China (English)

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

    2008-01-01

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

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

    OpenAIRE

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

    2010-01-01

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

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

    OpenAIRE

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

    2010-01-01

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

  7. Evaluation of corrosion effect in reinforced concrete by chloride exposure

    Science.gov (United States)

    Loreto, G.; Di Benedetti, M.; Iovino, R.; Nanni, A.; Gonzalez, M. A.

    2011-04-01

    Durability is generally described as the ability of a material to maintain its physical and mechanical properties over time. In reinforced concrete (RC) structures, concrete is the ideal material to protect the steel reinforcement given its high alkalinity. In environments subjected to highly aggressive conditions, mostly due to the presence of chlorides, concrete may lose its protective characteristics and allow for accelerated ageing. Concrete degradation and steel reinforcement corrosion are phenomena closely connected. The aim of this research work is the characterization of the relationship between steel reinforcement corrosion and concrete degradation under accelerated ageing in a 3% sodium chloride solution. The method of linear polarization is used for identification of the corrosion rate of the steel bar. Additionally, the values of concrete residual strength are obtained, and correlated to both the corrosion rate and width of concrete cracks. Finally, the prediction of the concrete cover useful life is estimated.

  8. Does Infrared Multiphoton Dissociation of Vinyl Chloride Yield Cold Vinylidene?

    Science.gov (United States)

    Fernando, Ravin; Qu, Chen; Bowman, Joel M; Field, Robert W; Suits, Arthur G

    2015-07-01

    Velocity map imaging of the infrared multiphoton dissociation of vinyl chloride shows the formation of HCl in rotational levels below J = 10 that are associated with the three-center elimination pathway. The total translational energy release is observed to peak at 3-5 kcal/mol, which is consistent with the low reverse barrier predicted for the formation of HCl with vinylidene coproducts. Direct dynamics trajectory studies from the three-center transition state reproduce the observed distributions and show that the associated vinylidene is formed with only modest rotational excitation, precluding Coriolis-induced mixing among the excited vibrational levels of acetylene that would lead to distribution of vinylidene character into many vibrationally mixed acetylene vibrational levels. The results suggest that infrared multiphoton dissociation of vinyl chloride is an efficient route to synthesis of stable, cold vinylidene. PMID:26266719

  9. Calibration of Yucca Mountain unsaturated zone flow and transport model using porewater chloride data.

    Science.gov (United States)

    Liu, Jianchun; Sonnenthal, Eric L; Bodvarsson, Gudmundur S

    2003-01-01

    In this study, porewater chloride data from Yucca Mountain, NV are analyzed and modeled by three-dimensional chemical transport simulation and analytical methods. The simulation modeling approach is based on a continuum formulation of coupled multiphase fluid flow and tracer transport processes through fractured porous rock using a dual-continuum concept. Infiltration rate calibrations were performed using the porewater chloride data. Model results of chloride distributions were improved in matching the observed data with the calibrated infiltration rates. Statistical analyses of the frequency distribution for overall percolation fluxes and chloride concentration in the unsaturated zone system demonstrate that the use of the calibrated infiltration rates had an insignificant effect on the distribution of simulated percolation fluxes but significantly changed the predicted distribution of simulated chloride concentrations. An analytical method was also applied to model transient chloride transport. The method was verified by three-dimensional simulation results to be capable of capturing major chemical transient behavior and trends. Effects of lateral flow in the Paintbrush nonwelded unit on percolation fluxes and chloride distribution were studied by three-dimensional simulations with increased horizontal permeability. The combined results from these model calibrations furnish important information for the UZ model studies, contributing to performance assessment of the potential repository. PMID:12714292

  10. Electrochemical Chloride extraction using external electrodes?

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Pedersen, Anne Juul

    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...

  11. Chloride binding site of neurotransmitter sodium symporters

    DEFF Research Database (Denmark)

    Kantcheva, Adriana Krassimirova; Quick, Matthias; Shi, Lei;

    2013-01-01

    Neurotransmitter:sodium symporters (NSSs) play a critical role in signaling by reuptake of neurotransmitters. Eukaryotic NSSs are chloride-dependent, whereas prokaryotic NSS homologs like LeuT are chloride-independent but contain an acidic residue (Glu290 in LeuT) at a site where eukaryotic NSSs...

  12. Reliability-Based Planning of Chloride Measurements

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Engelund, S.

    1996-01-01

    on measurements of the chloride content obtained from the given structure. In the present paper optimal planning of measurements of the chloride content in reinforced concrete structures is considered. It is shown how optimal experimental plans can be obtained using FORM-analysis. Bayesian statistics...

  13. Properties of silver chloride track detectors

    International Nuclear Information System (INIS)

    The experiments on preparation of silver chloride track detectors and their properties are described. The results of X-ray structural analysis and data on sensitivity to charged particles and actinic light of silver chloride crystals, doped with several elements, are presented. (orig.)

  14. Experiments on the transfer of heat and mass as a result of natural convection in the event of an air ingress accident in a high-temperature reactor

    International Nuclear Information System (INIS)

    To facilitate nuclear technology with high-temperature reactors without any risk of serious accidents, it is necessary to ensure that even the largest accidents will not have any significant effect on the area around the power station. In this case, it is vital to ensure the chemical stability of those reactors if there is an ingress of air as a result of an accident. A large-scale test installation is currently in operation at the Institute of Safety Research and Reactor Technology in the Research Centre Juelich. It is used to investigate the sequence of events and consequences of air ingress accidents of that kind. The experiments are designed to ascertain what the possible extent of the damage will be in certain scenarios and also to develop possible concepts for counteracting the damage and safeguarding the chemical stability of the system. Numerous experiments have been conducted on flow and mass transfer in the course of this study. These experiments describe the individual physical processes within the test installation. The findings derived from this on plant-specific loss of pressure, transfer of heat and material allow to interpret accident simulation experiments reliably and ensure that this data can be applied to the situation in high-temperature reactors using computer programs. (orig.)

  15. Containment Performance Evaluation of a Sodium Fire Event Due to Air Ingress into the Cover Gas Region of the Reactor Vessel in the PGSFR

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Sang June; Chang, Won-Pyo; Kang, Seok Hun; Choi, Chi-Woong; Yoo, Jin; Lee, Kwi Lim; Jeong, Jae-Ho; Lee, Seung Won; Jeong, Taekyeong; Ha, Kwi-Seok [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    Comparing with the light water reactor, sodium as a reactor coolant violently reacts with oxygen in the containment atmosphere. Due to this chemical reaction, heat generated from the combustion heat increases the temperature and pressure in the containment atmosphere. The structural integrity of the containment building which is a final radiological defense barrier is threaten. A sodium fire event in the containment due to air ingress into the cover gas region in the reactor vessel is classified as one of the design basis events in the PGSFR. This event comes from a leak or crack on the reactor upper closure header surface. It accompanys an event of the radiological fission products release to the inside the containment. In this paper, evaluation for the sodium fire and radiological influence due to air ingress into the cover gas region of the reactor vessel is described. To evaluate this event, the CONTAIN-LMR, MACCS-II and OR-IGEN-II codes are used. For the sodium pool fire event in the containment, the performance evaluation and radiological influence are carried out. In the thermal hydraulic aspects, the 1 cell containment yields the most conservative result. In this event, the maximum temperature and pressure in the containment are calculated 0.185 MPa, 280.0 .deg. C, respectively. The radiological dose at the EAB and LPZ are below the acceptance criteria specified in the 10CFR100.

  16. Numerical simulation of the facility behaviour of a high temperature reactor under water ingress accidents at the example of the AVR

    International Nuclear Information System (INIS)

    Detailed analysis of massive water ingress accidents in high temperature reactors supposes a numerical simulation of the whole facility behaviour. For the AVR-reactor such a model was developed to describe both, the graphite corrosion processes and the accident transients for different releasing events as well as resulting accident profiles. The variable consideration of regulating facilities of the safety circuit being influenced in reality, enables an optimization of the accident profiles in the way of a least possible facility damage. It results that in spite of extremely conservative input data with authorization legal relevance even the possible water ingress accidents can safely be controlled after 15 years of operation with steadily increasing safety requirements. First investigations on a selected facility concept for the AVR-reequipment show, that with the definition up to now of the AVR-steam generator failure the accident profiles ''reactor under pressure'' are conservatively coped with. An increasing degree of detail of the concept proposals, however, requires an examination of this statement. (orig.)

  17. Containment Performance Evaluation of a Sodium Fire Event Due to Air Ingress into the Cover Gas Region of the Reactor Vessel in the PGSFR

    International Nuclear Information System (INIS)

    Comparing with the light water reactor, sodium as a reactor coolant violently reacts with oxygen in the containment atmosphere. Due to this chemical reaction, heat generated from the combustion heat increases the temperature and pressure in the containment atmosphere. The structural integrity of the containment building which is a final radiological defense barrier is threaten. A sodium fire event in the containment due to air ingress into the cover gas region in the reactor vessel is classified as one of the design basis events in the PGSFR. This event comes from a leak or crack on the reactor upper closure header surface. It accompanys an event of the radiological fission products release to the inside the containment. In this paper, evaluation for the sodium fire and radiological influence due to air ingress into the cover gas region of the reactor vessel is described. To evaluate this event, the CONTAIN-LMR, MACCS-II and OR-IGEN-II codes are used. For the sodium pool fire event in the containment, the performance evaluation and radiological influence are carried out. In the thermal hydraulic aspects, the 1 cell containment yields the most conservative result. In this event, the maximum temperature and pressure in the containment are calculated 0.185 MPa, 280.0 .deg. C, respectively. The radiological dose at the EAB and LPZ are below the acceptance criteria specified in the 10CFR100

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

    International Nuclear Information System (INIS)

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

  19. Diffusion behavior of chloride ions in concrete

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-06-01

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

  20. Simple chloride sensors for continuous groundwater monitoring

    DEFF Research Database (Denmark)

    Thorn, Paul; Mortensen, John

    2012-01-01

    The development of chloride sensors which can be used for continuous, on-line monitoring of groundwater could be very valuable in the management of our coastal water resources. However, sensor stability, drift, and durability all need to be addressed in order for the sensors to be used in continu......The development of chloride sensors which can be used for continuous, on-line monitoring of groundwater could be very valuable in the management of our coastal water resources. However, sensor stability, drift, and durability all need to be addressed in order for the sensors to be used...... sensor remained responsive even at low chloride concentrations, where the conductivity electrode was no longer responding to changing chloride levels. With the results, it is believed that the simple chloride sensor could be used for continuous monitoring of groundwater quality....

  1. NEXAFS and XPS studies of nitrosyl chloride.

    Science.gov (United States)

    Schio, Luca; Li, Cui; Monti, Susanna; Salén, Peter; Yatsyna, Vasyl; Feifel, Raimund; Alagia, Michele; Richter, Robert; Falcinelli, Stefano; Stranges, Stefano; Zhaunerchyk, Vitali; Carravetta, Vincenzo

    2015-04-14

    The electronic structure of nitrosyl chloride (ClNO) has been investigated in the gas phase by X-ray Photoelectron (XPS) and Near Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy at the Cl 2p, Cl 2s, N 1s and O 1s edges in a combined experimental and theoretical study. The theoretical calculations at different levels of approximation predict ionization potential values in good agreement with the experimental data and allow us to assign the main features of the absorption spectra. An unexpected failure of the density functional model is, however, observed in the calculation of the Cl 2s binding energy, which is related to a large self-interaction error. Largely different photoabsorption cross-section patterns are experimentally observed in core excitations from the investigated quantum shells (n = 1, 2). This finding is confirmed by the oscillator strength distributions calculated at different absorption edges; in the case of the n = 2 shell the bands below the threshold are extremely weak and most of the absorption intensity is due to excitations in the continuum. PMID:25754872

  2. Membrane chloride transport measured using a chloride-sensitive fluorescent probe

    International Nuclear Information System (INIS)

    Transport of chloride across cell membranes through exchange, cotransport, or conductive pathways is a subject of great biological importance. Current methods of measurement are restricted in their sensitivity, time resolution, and applicability. A new transport measurement technique has been developed on the basis of the fluorescence quenching by chloride of the dye 6-methoxy-N-(3-sulfopropyl)quinolinium (SPQ). SPQ fluorescence quenching by chloride is rapid and sensitive, with a greater than 50% decrease in fluorescence at 10 mM chloride. SPQ fluorescence is not altered by other physiological anions or by pH and can be used to measure both neutral and conductive transport processes. The high water solubility and membrane permeability properties of SPQ make it ideal for use in both membrane vesicles and cells. Chloride transport determined with SPQ was validated by measurement of erythrocyte chloride/anion exchange and membrane vesicle chloride conductance using 35SO4 uptake

  3. Shelf life of unrefrigerated succinylcholine chloride injection.

    Science.gov (United States)

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

    1984-02-01

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

  4. 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.

  5. Chloride substitution in sodium borohydride

    Science.gov (United States)

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

    2011-07-01

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

  6. Amperometric Sensor for Detection of Chloride Ions

    OpenAIRE

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

    2008-01-01

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

  7. Binary Nucleation of Water and Sodium Chloride

    Energy Technology Data Exchange (ETDEWEB)

    Nemec, Thomas [Institute of Thermomechanics ASCR, Prague, Czech Republic; Marsik, Frantisek [Institute of Thermomechanics ASCR, Prague, Czech Republic; Palmer, Donald [ORNL

    2005-01-01

    Nucleation processes in the binary water-sodium chloride system are investigated in the sense of the classical nucleation theory (CNT). The CNT is modified to be able to handle the electrolytic nature of the system and is employed to investigate the acceleration of the nucleation process due to the presence of sodium chloride in the steam. This phenomenon, frequently observed in the Wilson zone of steam turbines, is called early condensation. Therefore, the nucleation rates of the water-sodium chloride mixture are of key importance in the power cycle industry.

  8. OECM MCCI Small-Scale Water Ingression and Crust Strength Tests (SSWICS) SSWICS-2 final data report, Rev. 0 February 12, 2003.

    Energy Technology Data Exchange (ETDEWEB)

    Lomperski, S.; Farmer, M. T.; Kilsdonk, D.; Aeschlimann, B. (Nuclear Engineering Division)

    2011-05-23

    The Melt Attack and Coolability Experiments (MACE) program at Argonne National Laboratory addressed the issue of the ability of water to cool and thermally stabilize a molten core/concrete interaction (MCCI) when the reactants are flooded from above. These tests provided data regarding the nature of corium interactions with concrete, the heat transfer rates from the melt to the overlying water pool, and the role of noncondensable gases in the mixing processes that contribute to melt quenching. However, due to the integral nature of these tests, several questions regarding the crust freezing behavior could not be adequately resolved. These questions include: (1) To what extent does water ingression into the crust increase the melt quench rate above the conduction-limited rate and how is this affected by melt composition and system pressure and (2) What is the fracture strength of the corium crust when subjected to a thermal-mechanical load and how does it depend upon the melt composition? A series of separate-effects experiments are being conducted to address these issues. The first employs an apparatus designed to measure the quench rate of a pool of corium ({approx}{phi}30 cm; up to 20 cm deep). The main parameter to be varied in these quench tests is the melt composition since it is thought to have a critical influence on the crust cracking behavior which, in turn, alters quench rate. The issue of crust strength will be addressed with a second apparatus designed to mechanically load the crust produced by the quench tests. This apparatus will measure the fracture strength of the crust while under a thermal load created by a heating element beneath the crust. The two apparatuses used to measure the melt quench rate and crust strength are jointly referred to as SSWICS (Small-Scale Water Ingression and Crust Strength). This report describes results of the second water ingression test, designated SSWICS-2. The test investigated the quench behavior of a 15 cm deep

  9. OECD MMCI Small-Scale Water Ingression and Crust Strength tests (SSWICS) SSWICS-1 final data report, Rev. 1 February 10, 2003.; Report, Rev. 1

    Energy Technology Data Exchange (ETDEWEB)

    Lomperski, S.; Farmer, M. T.; Kilsdonk, D.; Aeschlimann, B. (Nuclear Engineering Division)

    2011-05-23

    The Melt Attack and Coolability Experiments (MACE) program at Argonne National Laboratory addressed the issue of the ability of water to cool and thermally stabilize a molten core/concrete interaction (MCCI) when the reactants are flooded from above. These tests provided data regarding the nature of corium interactions with concrete, the heat transfer rates from the melt to the overlying water pool, and the role of noncondensable gases in the mixing processes that contribute to melt quenching. However, due to the integral nature of these tests, several questions regarding the crust freezing behavior could not be adequately resolved. These questions include: (1) To what extent does water ingression into the crust increase the melt quench rate above the conduction-limited rate and how is this affected by melt composition and system pressure; and (2) What is the fracture strength of the corium crust when subjected to a thermal-mechanical load and how does it depend upon the melt composition? A series of separate-effects experiments are being conducted to address these issues. The first employs an apparatus designed to measure the quench rate of a pool of corium ({approx}{phi}30 cm; up to 20 cm deep). The main parameter to be varied in these quench tests is the melt composition since it is thought to have a critical influence on the crust cracking behavior which, in turn, alters quench rate. The issue of crust strength will be addressed with a second apparatus designed to mechanically load the crust produced by the quench tests. This apparatus will measure the fracture strength of the crust while under a thermal load created by a heating element beneath the crust. The two apparatuses used to measure the melt quench rate and crust strength are jointly referred to as SSWICS (Small-Scale Water Ingression and Crust Strength). This report describes results of the first water ingression test, designated SSWICS-1. The test investigated the quench behavior of a 15 cm deep

  10. OECD MCCI Small-Scale Water Ingression and Crust Strength Tests (SSWICS) SSWICS-3 test data report : thermal Hydraulic results, Rev. 0 February 19, 2003.

    Energy Technology Data Exchange (ETDEWEB)

    Lomperski, S.; Farmer, M. T.; Kilsdonk, D.; Aeschlimann, B. (Nuclear Engineering Division)

    2011-05-23

    The Melt Attack and Coolability Experiments (MACE) program at Argonne National Laboratory addressed the issue of the ability of water to cool and thermally stabilize a molten core/concrete interaction (MCCI) when the reactants are flooded from above. These tests provided data regarding the nature of corium interactions with concrete, the heat transfer rates from the melt to the overlying water pool, and the role of noncondensable gases in the mixing processes that contribute to melt quenching. However, due to the integral nature of these tests, several questions regarding the crust freezing behavior could not be adequately resolved. These questions include: (1) To what extent does water ingression into the crust increase the melt quench rate above the conduction-limited rate and how is this affected by melt composition and system pressure and (2) What is the fracture strength of the corium crust when subjected to a thermal-mechanical load and how does it depend upon the melt composition? A series of separate-effects experiments are being conducted to address these issues. The first employs an apparatus designed to measure the quench rate of a pool of corium ({approx}{phi}30 cm; up to 20 cm deep). The main parameter to be varied in these quench tests is the melt composition since it is thought to have a critical influence on the crust cracking behavior which, in turn, alters quench rate. The issue of crust strength will be addressed with a second apparatus designed to mechanically load the crust produced by the quench tests. This apparatus will measure the fracture strength of the crust while under a thermal load created by a heating element beneath the crust. The two apparatuses used to measure the melt quench rate and crust strength are jointly referred to as SSWICS (Small-Scale Water Ingression and Crust Strength). This report describes results of the third water ingression test, designated SSWICS-3. This test investigated the quenching behavior of a fully

  11. OECD MMCI Small-Scale Water Ingression and Crust Strength Tests (SSWICS) SSWICS-2 test data report : thermal hydraulic results, Rev. 0 September 20, 2002.

    Energy Technology Data Exchange (ETDEWEB)

    Lomperski, S.; Farmer, M. T.; Kilsdonk, D. J.; Aeschlimann, R. W.; Basu, S. (Nuclear Engineering Division); (NRC)

    2011-05-23

    The Melt Attack and Coolability Experiments (MACE) program at Argonne National Laboratory addressed the issue of the ability of water to cool and thermally stabilize a molten core/concrete interaction (MCCI) when the reactants are flooded from above. These tests provided data regarding the nature of corium interactions with concrete, the heat transfer rates from the melt to the overlying water pool, and the role of noncondensable gases in the mixing processes that contribute to melt quenching. However, due to the integral nature of these tests, several questions regarding the crust freezing behavior could not be adequately resolved. These questions include: (1) To what extent does water ingression into the crust increase the melt quench rate above the conduction-limited rate and how is this affected by melt composition and system pressure and (2) What is the fracture strength of the corium crust when subjected to a thermal-mechanical load and how does it depend upon the melt composition? A series of separate-effects experiments are being conducted to address these issues. The first employs an apparatus designed to measure the quench rate of a pool of corium ({approx}{phi}30 cm; up to 20 cm deep). The main parameter to be varied in these quench tests is the melt composition since it is thought to have a critical influence on the crust cracking behavior which, in turn, alters quench rate. The issue of crust strength will be addressed with a second apparatus designed to mechanically load the crust produced by the quench tests. This apparatus will measure the fracture strength of the crust while under a thermal load created by a heating element beneath the crust. The two apparatuses used to measure the melt quench rate and crust strength are jointly referred to as SSWICS (Small-Scale Water Ingression and Crust Strength). This report describes results of the second water ingression test, designated SSWICS-2. The report includes a description of the test apparatus, the

  12. OECD MCCI project Small-Scale Water Ingression and Crust Strength Tests (SSWICS) SSWICS-1 test data report : thermal hydraulic results. Rev. 0 September 20, 2002.

    Energy Technology Data Exchange (ETDEWEB)

    Lomperski, S.; Farmer, M. T.; Kilsdonk, D. J.; Aeschlimann, R. W.; Basu, S. (Nuclear Engineering Division); (NRC)

    2011-05-23

    The Melt Attack and Coolability Experiments (MACE) program at Argonne National Laboratory addressed the issue of the ability of water to cool and thermally stabilize a molten core/concrete interaction (MCCI) when the reactants are flooded from above. These tests provided data regarding the nature of corium interactions with concrete, the heat transfer rates from the melt to the overlying water pool, and the role of noncondensable gases in the mixing processes that contribute to melt quenching. However, due to the integral nature of these tests, several questions regarding the crust freezing behavior could not be adequately resolved. These questions include: (1) To what extent does water ingression into the crust increase the melt quench rate above the conduction-limited rate and how is this affected by melt composition and system pressure and (2) What is the fracture strength of the corium crust when subjected to a thermal-mechanical load and how does it depend upon the melt composition? A series of separate-effects experiments are being conducted to address these issues. The first employs an apparatus designed to measure the quench rate of a pool of corium ({approx}{phi}30 cm; up to 20 cm deep). The main parameter to be varied in these quench tests is the melt composition since it is thought to have a critical influence on the crust cracking behavior which, in turn, alters quench rate. The issue of crust strength will be addressed with a second apparatus designed to mechanically load the crust produced by the quench tests. This apparatus will measure the fracture strength of the crust while under a thermal load created by a heating element beneath the crust. The two apparatuses used to measure the melt quench rate and crust strength are jointly referred to as SSWICS (Small-Scale Water Ingression and Crust Strength). This report describes results of the first water ingression test, designated SSWICS-1. The report includes a description of the test apparatus, the

  13. Catastrophic event modeling. [lithium thionyl chloride batteries

    Science.gov (United States)

    Frank, H. A.

    1981-01-01

    A mathematical model for the catastrophic failures (venting or explosion of the cell) in lithium thionyl chloride batteries is presented. The phenomenology of the various processes leading to cell failure is reviewed.

  14. A mathematical model of a lithium/thionyl chloride primary cell

    Science.gov (United States)

    Evans, T. I.; Nguyen, T. V.; White, R. E.

    1987-01-01

    A 1-D mathematical model for the lithium/thionyl chloride primary cell was developed to investigate methods of improving its performance and safety. The model includes many of the components of a typical lithium/thionyl chloride cell such as the porous lithium chloride film which forms on the lithium anode surface. The governing equations are formulated from fundamental conservation laws using porous electrode theory and concentrated solution theory. The model is used to predict 1-D, time dependent profiles of concentration, porosity, current, and potential as well as cell temperature and voltage. When a certain discharge rate is required, the model can be used to determine the design criteria and operating variables which yield high cell capacities. Model predictions can be used to establish operational and design limits within which the thermal runaway problem, inherent in these cells, can be avoided.

  15. Reinforcement Corrosion: Numerical Simulation and Service Life Prediction

    DEFF Research Database (Denmark)

    Michel, Alexander

    substances in concrete a heat and mass transport model was applied, which is based on thermodynamic principles. To incorporate the influence of temperature and chloride on the moisture sorption extensions were made using experimental results. The impact ofchlorides on the moisture sorption was accounted for...... concrete specimens was demonstrated comparing experimental ingress results and numerical simulations. The corrosion model, which is coupled to the transport model, was used to describe electrochemical processes at the reinforcement surface. The corrosion model was based on generally accepted physical laws...... describing thermodynamics and kinetics of electrochemical processes. The applicabilityof the model to capture various reinforcement corrosion phenomena, such as activation, resistance, and concentration polarisation as well as the impact of temperature and relative humidity was demonstrated comparing...

  16. Monoclonal antibodies to the apical chloride channel in Necturus gallbladder inhibit the chloride conductance.

    OpenAIRE

    Finn, A L; Tsai, L M; Falk, R J

    1989-01-01

    Monoclonal antibodies raised by injecting Necturus gallbladder cells into mice were tested for their ability to inhibit the apical chloride conductance induced by elevation of cellular cAMP. Five of these monoclonal antibodies bound to the apical cells, as shown by indirect immunofluorescence microscopy, and inhibited the chloride conductance; one antibody that bound only to subepithelial smooth muscle, by indirect immunofluorescence microscopy, showed no inhibition of chloride transport. The...

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

    OpenAIRE

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

    2009-01-01

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

  18. Telomerization of Vinyl Chloride with Chloroform Initiated by Ferrous Chloride-Dimethylacetamide under Ultrasonic Conditions

    Directory of Open Access Journals (Sweden)

    Hua Qian

    2015-01-01

    Full Text Available Telomerization of vinyl chloride with chloroform was investigated using ferrous chloride-dimethylacetamide system, and 42.1% yield, more than four times the one reported before, was achieved. The addition of ultrasound further improved the reaction and yield was raised to 51.9% with trace byproducts at highly reduced reaction time and temperature. Ferrous chloride-dimethylacetamide under ultrasonic irradiation acts as a very efficient catalyst system for the 1 : 1 telomerization.

  19. The kinetics of the hydrogen chloride oxidation

    Directory of Open Access Journals (Sweden)

    Gonzalez Martinez Isai

    2013-01-01

    Full Text Available Hydrogen chloride (HCl oxidation has been investigated on technical membrane electrode assemblies in a cyclone flow cell. Influence of Nafion loading, temperature and hydrogen chloride mole fraction in the gas phase has been studied. The apparent kinetic parameters like reaction order with respect to HCl, Tafel slope and activation energy have been determined from polarization data. The apparent kinetic parameters suggest that the recombination of adsorbed Cl intermediate is the rate determining step.

  20. Estimating the chloride transport in cement paste

    OpenAIRE

    Princigallo, A.

    2012-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

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

  2. Reduction in cobalt ingress from fuelling machine stellite wear products into primary heat transport system: results from modeling assessment of ion exchange clean-up

    International Nuclear Information System (INIS)

    This paper presents an analysis of the benefit of installing ion exchange capability in the heavy water auxiliary system of a Darlington fuelling machine. An overall mass balance model was developed to estimate the potential reduction in cobalt ingress from the fuelling machine into the primary heat transport system. The analysis considered generation terms from a) on-going ram ball wear and b) dissolution from the surfaces of trapped filter particulates as well as from ram ball surfaces and removal terms arising from a) flow injection into the reactor system, b) filtration and c) ion exchange. Model equations were solved for each activity in the fueling cycle to determine the aggregate behavior over an extended period of operation. Results from model calculations suggest that, without ion exchange provisions, about 16.7 g/year of cobalt enters the reactor system from each fuelling machine. The majority of this cobalt (66%) is in particulate form with the balance being in dissolved form (soluble as well as colloidal). Most of the dissolved cobalt (80 %) is generated from the surfaces of the ram balls, the remainder being from the surfaces of the trapped filter particulates. The potential reduction in cobalt ingress from ion exchange operation was estimated to be 21% or 3.5 g/year per fuelling machine. Based on a postulated growth curve for the Co-60 reactor face fields, estimates were also obtained for the net plant dose savings that would result from ion exchange operation. This was estimated for the period 2010 - 2022 to exceed 480 rem. Based on the analysis performed, installation of ion exchange purification capability in the heavy water auxiliary system is strongly recommended. (author)

  3. Experimental investigations of graphite corrosion and aerosol formation during air ingress into the core of a high temperature pebble bed reactor

    International Nuclear Information System (INIS)

    A High Temperature Reactor can be designed to remove the decay heat without using any active systems. For most accident scenarios a release of radioactive fission products can be excluded by design. However, during operation of a HTR some accidents are principally possible, which can result in a release of fission products out of the fuel elements and of the reactor system. One of these accidents is a hypothetical massive air ingress into the hot graphite reactor core. After a pressure drop caused by leakages in the primary circuit a gas mass flow may be able to stream through the core according to free natural convection leading to a corrosion of the graphite fuel elements and reflector structures. With the VELUNA-experiment a testing device was installed, which allows to investigate the corrosion process on parts of a reactor core under real accident conditions. With regard to the experimental results already existing equations to calculate the chemical reaction rate in a pebble bed were modified and the applicability was demonstrated. These equations consider the chemical reaction in the porous graphite as well as diffusion processes to the graphite surface. Equivalent correlations were developed for different flow geometries and for the graphite material of the bottom reflector. The corrosion process forms an aerosol, which consists of graphite particles and a reaction gas phase. The formatted aerosol was characterized concerning its chemical and physical properties. Because the aerosol particles can support the release of fission products, measurements of aerosol parameters like particle mass concentration and particle size distribution provide important information to estimate the radiologic consequences of such an hypothetical air ingress accident. (orig.)

  4. 49 CFR 179.102-17 - Hydrogen chloride, refrigerated liquid.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Hydrogen chloride, refrigerated liquid. 179.102-17...) § 179.102-17 Hydrogen chloride, refrigerated liquid. Each tank car used to transport hydrogen chloride... on or after March 16, 2009 used for the transportation of hydrogen chloride, refrigerated...

  5. 21 CFR 178.3290 - Chromic chloride complexes.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Chromic chloride complexes. 178.3290 Section 178... SANITIZERS Certain Adjuvants and Production Aids § 178.3290 Chromic chloride complexes. Myristo chromic chloride complex and stearato chromic chloride complex may be safely used as release agents in the...

  6. Sensitivity Analysis of Chloride Ion Diffusion in Concrete Subjected to Marine Environment%海工环境混凝土中氯离子扩散敏感性分析

    Institute of Scientific and Technical Information of China (English)

    郝风田; 路影

    2013-01-01

    The sufficient attention may be paid attention to the durability of reinforced concrete structure all over the world at present .The concrete structures would be subjected to chloride ingress ,resulting in the corrosion of reinforcing bars ,inducing early deterioration and losing their durability ,and this is a main problem in engineering practices .Based on the second Fick’s law ,and taking into account the surface chloride concentration ,temperature ,water cement ratio , and initial chloride content ,the chloride ion diffusion is calculated and analyzed here .The sensitivity analysis shows that the influence factors of surface chloride concentration ,temperature ,water cement ratio of concrete are obvious ,and the influence of initial chloride content is weaker .%混凝土结构耐久性问题是当今世界普遍关注的问题。由于氯离子侵蚀,导致钢筋锈蚀,使结构发生早期破坏,丧失了结构的耐久性能,已成为实际工程中的重要问题。基于 Fick 第二定律,分别考虑表面氯离子浓度、温度、水灰比、初始氯离子含量,计算氯离子扩散。敏感性分析表明表面氯离子浓度、温度、水灰比对混凝土中氯离子扩散影响较大,初始氯离子含量影响较小。

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

    Directory of Open Access Journals (Sweden)

    H. Guan

    2009-09-01

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

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

    Science.gov (United States)

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

    1980-01-01

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

  9. 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.

  10. Chloride Migration in Heterogeneous Soil - 2. Stohastic Modeling

    DEFF Research Database (Denmark)

    Destouni, Geogia; Sassner, Mona; Jensen, Karsten Høgh

    1994-01-01

    The observed statistics of chloride breakthrough presented by Sassner et al. (this issue) were compared with predictions of a stochastic-advective modeling approach. The stochastic-advective model based on the observed spatial distribution of flow rates and on transport parameters consistent with...... parameter values obtained from local breakthrough curves (BTCs) agreed well with the observations. Alternative models that agreed well with the local BTCs failed to predict the large-scale BTC with realistic parameter values. The results support the assumption that compared to advection variability, local...... dispersion within the mobile water will often have a second-order effect on field scale solute transport. The stochastic-advective model is robust with regard to the rate of mass transfer between mobile and immobile water zones. This robustness implies that order of magnitude estimates may be sufficient for...

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

    International Nuclear Information System (INIS)

    Highlights: ► A kinetic model was used to predict the radical species and their distributions. ► The generated radical species were identified by EPR. ► The second-order rate constants of sulfate radical with PCBs were determined. - Abstract: Advanced oxidation processes (AOPs) based on sulfate radical (SO4·−) 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′-CB (PCB28) and biphenyl (BP) by persulfate, based on the produced SO4·−. 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 SO4·− 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.

  12. Hydrolysis of ferric chloride in solution

    International Nuclear Information System (INIS)

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

  13. Chloride equilibrium potential in salamander cones

    Directory of Open Access Journals (Sweden)

    Bryson Eric J

    2004-12-01

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

  14. Durability of concrete in saline environment

    OpenAIRE

    1996-01-01

    Contents: - Systematic collection of field data for service life prediction of concrete structures. - Moisture in marine concrete structures - Studies in the BMV-project 1992-1996. - Scaling resistence of concrete field exposure tests. - Chloride induced corrosion in marine concrete structures. - Chloride threshold values in reinforced concrete. - A new method for determing chloride thresholds as a function of potential in field exposure tests. - Estimation of chloride ingress into concrete a...

  15. Modeling of the ionic transfers in saturated porous media: application to the penetration of chlorides through cementing materials

    International Nuclear Information System (INIS)

    In this work, the problem of ionic species transport through concrete porous media has been documented. Chloride ions penetration in cementitious materials is one of the processes widely responsible for the degradation of concrete structures. Therefore there exists an immense need for its correct understanding and quantification. Different research groups worldwide have proposed different chloride ingress models. Here, a one-dimensional model based on a multi-species approach of the ionic transport is presented. It is the new version of a previous model MsDiff developed a few years ago in our group that describes the diffusion of ionic species with the Nernst-Planck equation instead of Fick's laws. This newer version is named, the package version of MsDiff after it requires a package of five input data at any given age of concrete. With a multi-species approach, it is possible to take into account the interactions, which exist among different ionic species in pore solution of concrete. The numerical scheme of the model is based on finite difference method with Crank-Nickolson and Law-Wendroff techniques. In order to run MsDiff, we do need an input data. Several experiments were performed accordingly to provide experimental feedback to MsDiff. Standard immersion tests were conducted to validate the outcomes of MsDiff. Special attention is given to the diffusion coefficients of the ions and the interactions between the ionic species and the solid phase. In addition to MsDiff, some other existing models were also tried for the sake of comparison with the experimental chloride profiles. Certain experimentation was conducted to watch the effect of exposure period, concrete age at exposure and concentration in the environmental solution. In the end, the simulations were performed with MsDiff in order to calculate the chloride-induced corrosion initiation time using the experimental data already achieved while making use of different criteria adopted by different research

  16. Combining sulfate electrowinning with chloride leaching

    Science.gov (United States)

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

    1991-08-01

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

  17. Determination of persimmon leaf chloride contents using near-infrared spectroscopy (NIRS).

    Science.gov (United States)

    de Paz, José Miguel; Visconti, Fernando; Chiaravalle, Mara; Quiñones, Ana

    2016-05-01

    Early diagnosis of specific chloride toxicity in persimmon trees requires the reliable and fast determination of the leaf chloride content, which is usually performed by means of a cumbersome, expensive and time-consuming wet analysis. A methodology has been developed in this study as an alternative to determine chloride in persimmon leaves using near-infrared spectroscopy (NIRS) in combination with multivariate calibration techniques. Based on a training dataset of 134 samples, a predictive model was developed from their NIR spectral data. For modelling, the partial least squares regression (PLSR) method was used. The best model was obtained with the first derivative of the apparent absorbance and using just 10 latent components. In the subsequent external validation carried out with 35 external data this model reached r (2) = 0.93, RMSE = 0.16 % and RPD = 3.6, with standard error of 0.026 % and bias of -0.05 %. From these results, the model based on NIR spectral readings can be used for speeding up the laboratory determination of chloride in persimmon leaves with only a modest loss of precision. The intermolecular interaction between chloride ions and the peptide bonds in leaf proteins through hydrogen bonding, i.e. N-H···Cl, explains the ability for chloride determinations on the basis of NIR spectra. Graphical Abstract The NIRS-PLSR alternative to the wet reference analytical method for chloride determination in persimmon leaves saves lab work in exchange of a modest loss of precissionᅟ. PMID:26935930

  18. Degradation of benzalkonium chloride coupling photochemical advanced oxidation technologies with biological processes

    International Nuclear Information System (INIS)

    The combination of Advanced Oxidation Technologies (AOTs) and biological processes can be visualized as a very successful technological option for treatment of effluents, because it combines high oxidizing technologies with a conventional, low-cost and well-established treatment technology.Photochemical AOTs, like UV-C with or without H2O2, photo-Fenton (PF, UV/H2O2/Fe(II-III)) and UV/TiO2 heterogeneous photo catalysis involve the generation and use of powerful oxidizing species, mainly the hydroxyl radical.In almost all AOTs, it is possible to use sunlight. Benzalkonium chloride (dodecyldimetylbencylammonium chloride, BKC) is a widely used surfactant, which has many industrial applications.Due to its antibacterial effect, it cannot be eliminated from effluents by a biological treatment, and the complexity of its chemical structure makes necessary the use of drastic oxidizing treatments to achieve complete mineralization and to avoid the formation of byproducts even more toxic than the initial compound.In this study, different alternatives for BKC treatment using photochemical AOTs followed by bio catalytic techniques are presented.Three AOTs were tested: a) UV-C (254 nm, germicide lamp) with and without H2O2, b) PF (366 nm), c) UV/TiO2 (254 and 366 nm). PF at a 15:1:1 H2O2total/BKC0/Fe0 molar ratio at 55 degree C was the most efficient treatment in order to decrease the tensioactivity and the total organic carbon of the solution . The biocatalysis was studied in a reactor fitted with a biofilm of microorganisms coming from a sludge-water treatment plant. To evaluate the maximal BKC concentration that could be allowed to ingress to the biological reactor after the AOT treatment, the toxicity of solutions of different BKC concentrations was analyzed. The study of the relevant parameters of both processes and their combination allowed to establish the preliminary conditions for optimizing the pollutant degradation

  19. Alkali metal and ammonium chlorides in water and heavy water (binary systems)

    CERN Document Server

    Cohen-Adad, R

    1991-01-01

    This volume surveys the data available in the literature for solid-fluid solubility equilibria plus selected solid-liquid-vapour equilibria, for binary systems containing alkali and ammonium chlorides in water or heavy water. Solubilities covered are lithium chloride, sodium chloride, potassium chloride, rubidium chloride, caesium chloride and ammonium chloride in water and heavy water.

  20. Hydrogenation of Tasmanian alginite in the presence of tin (II) chloride and zinc chloride

    Energy Technology Data Exchange (ETDEWEB)

    Russell, N.J.

    1981-10-01

    A Mersey River (Tasmanian) algnite concentrate was heated (3 Cmin$SUP$-$SUP$1 to temperatures of 200-480 C in a small capacity, high-pressure, single-cell differential thermal analysis, batch autoclave under nitrogen or hydrogen (initial pressure 9.8 MPa) with or without 10 wt% zinc chloride or tin (II) chloride. An organic solvent (vehicle) was not used in these experiments. Although there is an almost complete conversion of alginite to gaseous and liquid products between 425 and 450 C, the compositions of the autoclave gas samples, the yields and compositions of the hexane-soluble material derived from the autoclave products, and the optical properties of the hexane-soluble residues, reflect the experimental conditions, in particular the influence of the metal chlorides. Principal phases of hydrogen uptake by alginite occur at different temperatures in a hydrogen atmosphere depending on the presence and nature of the metal chloride. The autoclave gas compositions reveal a clear distinction between the uncatalysed and catalysed experiments. The hydrocarbon gas ratios permit a distinction to be made between catalytic (carbonium ion mechanism) reactions and thermal (free radical mechanism) reactions; at higher temperatures the latter are dominant, even in the catalysed experiments. The metal chlorides lower the organic sulphur and nitrogen contents of the hexane-soluble material; zinc chloride being more effective than tin (II) chloride. Incident light fluorescence microscopy suggests that zinc chloride and tin (II) chloride give rise to different hydrogenation reactions between 300 and 425 C. Incident light fluorescence microscopy is a most useful method of studying the petrography of alignite in the hexane-insoluble residues. (28 refs.)

  1. Meso-scale modeling of chloride diffusion in concrete with consideration of effects of time and temperature

    Institute of Scientific and Technical Information of China (English)

    Li-cheng WANG; Tamon UEDA

    2009-01-01

    A meso-scale truss network model was developed to predict chloride diffusion in concrete.The model regards concrete as a three-phase composite of mortar matrix,coarse aggregates,and the interfacial transition zone (ITZ) between the mortar matrix and the aggregates.The diffusion coefficient of chloride in the mortar and the ITZ can be analytically determined with only the water-to-cement ratio and volume fraction of fine aggregates.Fick's second law of diffusion was used as the governing equation for chloride diffusion in a homogenous medium (e.g.,mortar);it was discretized and applied to the truss network model.The solution procedure of the truss network model based on the diffusion law and the meso-scale composite structure of concrete is outlined.Additionally,the dependence of the diffusion coefficient of chloride in the mortar and the ITZ on exposure duration and temperature is taken into account to illustrate their effect on chloride diffusion coefficient.The numerical results show that the exposure duration and environmental temperature play important roles in the diffusion rate of chloride ions in concrete.It is also concluded that the meso-scale truss network model can be applied to chloride transport analysis of damaged (or cracked) concrete.

  2. Method for preparation of melts of alkali metal chlorides with highly volatile polyvalent metal chlorides

    International Nuclear Information System (INIS)

    A method for production of alkali metal (Cs, Rb, K) chloride melts with highly volatile polyvalent metal chlorides is suggested. The method consists, in saturation of alkali metal chlorides, preheated to the melting point, by volatile component vapours (titanium tetrachloride, molybdenum or tantalum pentachloride) in proportion, corresponding to the composition reguired. The saturation is realized in an evacuated vessel with two heating areas for 1-1.5 h. After gradual levelling of temperature in both areas the product is rapidly cooled. 1 fig.; 1 tab

  3. A Thermo-Hygro-Coupled Model for Chloride Penetration in Concrete Structures

    Directory of Open Access Journals (Sweden)

    Nattapong Damrongwiriyanupap

    2015-01-01

    Full Text Available Corrosion damage due to chloride attack is one of the most concerning issues for long term durability of reinforced concrete structures. By developing the reliable mathematical model of chloride penetration into concrete structures, it can help structural engineers and management agencies with predicting the service life of reinforced concrete structures in order to effectively schedule the maintenance, repair, and rehabilitation program. This paper presents a theoretical and computational model for chloride diffusion in concrete structures. The governing equations are taking into account the coupled transport process of chloride ions, moisture, and temperature. This represents the actual condition of concrete structures which are always found in nonsaturated and nonisothermal conditions. The fully coupled effects among chloride, moisture, and heat diffusion are considered and included in the model. The coupling parameters evaluated based on the available material models and test data are proposed and explicitly incorporated in the governing equations. The numerical analysis of coupled transport equations is performed using the finite element method. The model is validated by comparing the numerical results against the available experimental data and a good agreement is observed.

  4. Oral cadmium chloride intoxication in mice

    DEFF Research Database (Denmark)

    Andersen, O; Nielsen, J B; Svendsen, P

    1988-01-01

    Diethyldithiocarbamate (DDC) is known to alleviate acute toxicity due to injection of cadmium salts. However, when cadmium chloride was administered by the oral route, DDC enhanced rather than alleviated the acute toxicity; both oral and intraperitoneal (i.p.) administration of DDC had this effec...

  5. Liquid crystalline critical dynamics in decylammonium chloride

    CERN Document Server

    Lee, K W; Lee, C E; Kang, K H; Rhee, C; Kang, J K

    1999-01-01

    Collective chain dynamics and phase transitions in a model biomembrane, decylammonium chloride (C sub 1 sub 0 H sub 2 sub 1 NH sub 3 Cl), were studied by means of proton nuclear magnetic resonance. Our measurements sensitively reflect the critical dynamics associated with the smectic C to smectic A transition of the lipid bilayer.

  6. Liquid crystalline critical dynamics in decylammonium chloride

    International Nuclear Information System (INIS)

    Collective chain dynamics and phase transitions in a model biomembrane, decylammonium chloride (C10H21NH3Cl), were studied by means of proton nuclear magnetic resonance. Our measurements sensitively reflect the critical dynamics associated with the smectic C to smectic A transition of the lipid bilayer

  7. Chloride diffusion in partially saturated cementitious material

    DEFF Research Database (Denmark)

    Nielsen, Erik Pram; Geiker, Mette Rica

    2003-01-01

    The paper proposes a combined application of composite theory and Powers' model for microstructural development for the estimation of the diffusion coefficient as a function of the moisture content of a defect-free cementitious material. Measurements of chloride diffusion in mortar samples (440 kg...

  8. 75 FR 19657 - Barium Chloride From China

    Science.gov (United States)

    2010-04-15

    ... Commission found that the domestic interested party group response to its notice of institution (74 FR 31757... COMMISSION Barium Chloride From China AGENCY: United States International Trade Commission. ACTION: Notice of Commission determination to conduct a full five-year review concerning the antidumping duty order on...

  9. 75 FR 20625 - Barium Chloride From China

    Science.gov (United States)

    2010-04-20

    ... established a schedule for the conduct of this review (74 FR 62587, November 30, 2010). Subsequently, counsel... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Barium Chloride From China AGENCY: United States International Trade Commission. ACTION:...

  10. Chloride concentration affects soil microbial community

    Czech Academy of Sciences Publication Activity Database

    Gryndler, Milan; Rohlenová, Jana; Kopecký, Jan; Matucha, Miroslav

    2008-01-01

    Roč. 71, č. 7 (2008), s. 1401-1408. ISSN 0045-6535 R&D Projects: GA ČR GA526/05/0636 Institutional research plan: CEZ:AV0Z50200510; CEZ:AV0Z50380511 Keywords : soil chloride * terminal restriction fragments * soil microorganisms Subject RIV: EE - Microbiology, Virology Impact factor: 3.054, year: 2008

  11. Determination of chloride in uranium solutions

    Energy Technology Data Exchange (ETDEWEB)

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

    1967-05-15

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

  12. Amperometric Sensor for Detection of Chloride Ions

    Directory of Open Access Journals (Sweden)

    Rene Kizek

    2008-09-01

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

  13. Polyvinyl chloride filled with bismuth oxychloride powder

    Czech Academy of Sciences Publication Activity Database

    Polášková, M.; Sedláček, T.; Kharlamov, Alexander; Pivokonský, Radek; Saha, P.

    Larnaca : Polymer Processing Society, 2009, s. 242. [Polymer Processing Society Europe/Africa Regional Meeting. Larnaca (GR), 18.10.2009-21.10.2009] Institutional research plan: CEZ:AV0Z20600510 Keywords : olyvinyl chloride * bismuth oxychloride * radiopaque agents Subject RIV: BK - Fluid Dynamics

  14. Regulated trafficking of the CFTR chloride channel

    NARCIS (Netherlands)

    Braakman, L.J.; Kleizen, B.; Jonge, H.R. de

    2000-01-01

    The cystic fibrosis transmembrane conductance regulator (CFTR), the ABC transporter encoded by the cystic fibrosis gene, is localized in the apical membrane of epithelial cells where it functions as a cyclic AMP-regulated chloride channel and as a regulator of other ion channels and transporters. Wh

  15. Binary nucleation of water and sodium chloride

    Czech Academy of Sciences Publication Activity Database

    Němec, Tomáš; Maršík, František; Palmer, A.

    2006-01-01

    Roč. 124, č. 4 (2006), 0445091-0445096. ISSN 0021-9606 R&D Projects: GA ČR(CZ) GA101/05/2536 Institutional research plan: CEZ:AV0Z20760514 Keywords : binary nucleation * sodium chloride * water Subject RIV: BJ - Thermodynamics Impact factor: 3.166, year: 2006

  16. 21 CFR 184.1446 - Manganese chloride.

    Science.gov (United States)

    2010-04-01

    ..., and crystallized. (b) The ingredient meets the specifications of the Food Chemicals Codex, 3d Ed... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Manganese chloride. 184.1446 Section 184.1446 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD...

  17. Some perspective decisions for the regeneration system equipment of the thermal and nuclear power plants decreasing the probability of water ingress into the turbine and rotor acceleration by return steam flow

    Science.gov (United States)

    Trifonov, N. N.; Svyatkin, F. A.; Sintsova, T. G.; Ukhanova, M. G.; Yesin, S. B.; Nikolayenkova, E. K.; Yurchenko, A. Yu.; Grigorieva, E. B.

    2016-03-01

    The regeneration system heaters are one of the sources of possible ingress of the water into the turbine. The water penetrates into the turbine either at the heaters overflow or with the return flow of steam generated when the water being in the heater boils up in the dynamic operation modes or at deenergization of the power-generating unit. The return flow of steam and water is dangerous to the turbine blades and can result in the rotor acceleration. The known protective devices used to prevent the overflow of the low-pressure and high-pressure heaters (LPH and HPH), of the horizontal and vertical heaters of heating-system water (HWH and VWH), as well as of the deaerators and low-pressure mixing heaters (LPMH) were considered. The main protective methods of the steam and water return flows supplied by the heaters in dynamic operation modes or at deenergization of the power-generating unit are described. Previous operating experience shows that the available protections do not fully prevent water ingress into the turbine and the rotor acceleration and, therefore, the development of measures to decrease the possibility of ingress of the water into the turbine is an actual problem. The measures allowing eliminating or reducing the water mass in the heaters are expounded; some of them were designed by the specialists of OAO Polzunov Scientific and Development Association on Research and Design of Power Equipment (NPO CKTI) and are efficiently introduced at heat power plants and nuclear power plants. The suggested technical solutions allow reducing the possibility of the water ingress into the turbine and rotor acceleration by return steam flow in the dynamic operation modes or in the case of power generating unit deenergization. Some of these solutions have been tested in experimental-industrial exploitation and can be used in industry.

  18. Hydrolysis of ferric chloride in solution

    Energy Technology Data Exchange (ETDEWEB)

    Lussiez, G.; Beckstead, L.

    1996-11-01

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

  19. Marine Ingressive Events Recorded in Epicontinental Sequences:Example from the Cretaceous Songliao Basin of NE China in Comparison with the Triassic Central Europe Basin of SW Germany

    Institute of Scientific and Technical Information of China (English)

    WANG Pujun; LIU Wanzhu; YIN Xiuzhen; SCHNEIDER Werner; MATTERN Frank

    2002-01-01

    Songliao Basin is filled predominantly with continental facies sediments including alluvial fan, fluvial plain, fan delta, lacustrine delta, shore - shallow lacustrine, beach salty flat, semi - deep to deep lacustrine, subaqueous gravity flow,lacustrine swamp and pyroclastic sediments. However, some event units were formed during lake - marine linking periods of the Mid - Cretaceous in the basin, which include black shales with high values for salinity (Sr/Ba) , alkalinity ( Ca + Mg)/(Si + Al) , reducibility (Ni + Zn)/Ga and sulfide sulfur as well as heavy isotopes. The Breitenholz -section to be represented for facies comparison with the Cretaceous evaporitic series in Northeast China is localized in Southwest Germany. Stratigraphically it belongs to the Crabfeld Formation of Keuper of the Germanic Triassic corresponding to Ladinian - Carnian of the international reference scale, and is generally called Lower Gipskeuper. The Germanic Triassic was deposited in the epicontinental (cratonic) central Europe Basin. It covered the area in between Great Britain, North Sea, Poland and Southern Germany. It is composed of cyclic deposits of multicolored mudstones, gypsum/anhydrite, and dolomite beds. The two cases of marine ingression - influenced sequences share some common features.

  20. Viscosity and density tables of sodium chloride solutions

    Energy Technology Data Exchange (ETDEWEB)

    Fair, J.A.; Ozbek, H. (comps.)

    1977-04-01

    A file is presented containing tabulated data extracted from the scientific literature on the density and viscosity of aqueous sodium chloride solutions. Also included is a bibliography of the properties of aqueous sodium chloride solutions. (MHR)

  1. Removal of iron contaminant from zirconium chloride solution

    International Nuclear Information System (INIS)

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

  2. Kinetics of Vinyl Chloride Polymerization with Mixture of Initiators

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Kinetic models for the rate constants of vinyl chloride polymerization in the presence of initiator mixtures were proposed. They may be used to design the initiator recipes for the vinyl chloride polymerization with uniform rate at different temperatures at which various grades of poly(vinyl chloride) will be prepared.

  3. STABILISATION OF SILTY CLAY SOIL USING CHLORIDE

    Directory of Open Access Journals (Sweden)

    TAMADHER T. ABOOD

    2007-04-01

    Full Text Available The object of this paper is to investigate the effect of adding different chloride compounds including (NaCl, MgCl2, CaCl2 on the engineering properties of silty clay soil. Various amounts of salts (2%, 4%, and 8% were added to the soil to study the effect of salts on the compaction characteristics, consistency limits and compressive strength. The main findings of this study were that the increase in the percentage of each of the chloride compounds increased the maximum dry density and decrease the optimum moisture content. The liquid limit, plastic limit and plasticity index decreased with the increase in salt content. The unconfinedcompressive strength increased as the salt content increased.

  4. BARRIER PROPERTIES OF VINYLIDENE CHLORIDE COPOLYMERS

    Institute of Scientific and Technical Information of China (English)

    LI Yuesheng; WENG Zhixue; HUANG Zhiming; PAN Zuren

    1996-01-01

    The permeability coefficients of a series of copolymers of vinylidene chloride (VDC)with methyl acrylate (MA), butyl acrylate (BA) or vinyl chloride (VC) (as comonomer)to oxygen and carbon dioxide have been measured at 1.0 MPa and 30℃, while those to water vapor have been measured at 30℃ and 100% relative humidity. All the copolymers are semicrystalline. VDC/MA copolymers have lower melting temperature compared with VDC/BA copolymers, while that melting temperature of VDC/VC copolymer is higher than that of VDC/acrylate copolymers with the same VDC content. The barrier property of the copolymers is predominantly controlled by crystallite, free volume fraction, and cohesive energy. The permeability coefficients of VDC/MA copolymers to oxygen, carbon dioxide, and water vapor were successfully correlated with the ratio of free volume to cohesive energy.

  5. Chloride migration in concrete with superabsorbent polymers

    DEFF Research Database (Denmark)

    Hasholt, Marianne Tange; Jensen, Ole Mejlhede

    2015-01-01

    Superabsorbent polymers (SAP) can be used as a means for internal curing of concrete. In the present study, the development of transport properties of concrete with SAP is investigated. The chloride migration coefficient according to NT BUILD 492 is used as a measure of this. Twenty concrete...... mixtures are tested 7, 14, and 28 days after casting. The development of degree of hydration is followed for 20 corresponding paste mixtures. Both when SAP is added with extra water to compensate the SAP water absorption in fresh concrete and without extra water, the internal curing water held by SAP may...... contribute to increase the degree of hydration. No matter if SAP is added with or without extra water, it appears that the so-called gel space ratio can be used as a key parameter to link age and mixture proportions (water-to-cement ratio and SAP dosage) to the resulting chloride migration coefficient; the...

  6. Influence of chloride admixtures on cement matrix durability

    International Nuclear Information System (INIS)

    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 500C, 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

  7. Acylation of Toluene with Isobutyryl Chloride

    Czech Academy of Sciences Publication Activity Database

    Čejka, Jiří; Klisáková, Jana; Žilková, Naděžda; Červený, L.

    Cape Town, 2004 - ( Steen van, E.), s. 2717-2723 ISBN 0-958-46636-X. [International Zeolite Conference /14./. Cape Town (ZA), 25.04.2004-30.04.2004] R&D Projects: GA ČR GA203/03/0804 Institutional research plan: CEZ:AV0Z4040901 Keywords : acylation of toluene * isobutyryl chloride * zeolites Subject RIV: CF - Physical ; Theoretical Chemistry

  8. Chloride migration in concrete with superabsorbent polymers

    OpenAIRE

    Hasholt, Marianne Tange; Jensen, Ole Mejlhede

    2015-01-01

    Superabsorbent polymers (SAP) can be used as a means for internal curing of concrete. In the present study, the development of transport properties of concrete with SAP is investigated. The chloride migration coefficient according to NT BUILD 492 is used as a measure of this. Twenty concrete mixtures aretested 7, 14, and 28 days after casting. The development of degree of hydration is followed for 20 corresponding paste mixtures.Both when SAP is added with extra water to compensate the SAP wa...

  9. Gasometric titration for dimethylaluminum chloride analysis.

    Science.gov (United States)

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

    2016-06-01

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

  10. A Duplex Stainless Steel for Chloride Environments

    Science.gov (United States)

    Sridhar, N.; Kolts, J.; Flasche, L. H.

    1985-03-01

    This paper examines the effects of microstructural changes on the corrosion, stress corrosion cracking and corrosion fatigue resistance of a duplex stainless steel to chloride environments. The microstructural changes can be precipitation of phases such as sigma and carbides, or changes in the distribution of austenite and ferrite. The former can be important in hot forming operations while the latter is important in welding. The methods of minimizing these deleterious effects can sometimes be different from those used for austenitic stainless steel.

  11. Electrodeposition of Zinc from Chloride Solution

    OpenAIRE

    NAIK, Yanjerappa Arthoba; VENKATESHA, Thimmappa Venkatarangaiah

    2002-01-01

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

  12. Electrochemical behaviours of scandium in chloride melts

    International Nuclear Information System (INIS)

    Electrochemical behaviour of scandium(3) ions in an eutectic melt of NaCl-KCl-CsCl at 810-850 K is studied by cyclic voltammetry and chronoamperometry. The process of cathodic reduction of scandium complex ions in chloride melts is found to proceed according to the scheme: Sc(3) → Sc(0) and to be controlled by the rate of ScCl63- complex dissociation

  13. (tert-Butyl(2-hydroxyethylammonium chloride

    Directory of Open Access Journals (Sweden)

    Cintya Valerio-Cárdenas

    2014-07-01

    Full Text Available In the cation of the title molecular salt, C6H16NO+·Cl−, the N—C—C—O torsion angle is 176.5 (2°. In the crystal, the cations and chloride ions are linked by N—H...O and O—H...O hydrogen bonds, generating a two-dimensional network parallel to (100.

  14. Manganese laser using manganese chloride as lasant

    Science.gov (United States)

    Chen, C. J.

    1974-01-01

    A manganese vapor laser utilizing manganese chloride as a lasant has been observed and investigated. Lasing is attained by means of two consecutive electrical discharges. The maximum laser output is obtained at a vapor pressure of about 3 torr, a temperature of 680 C, and a time delay between electrical discharges of 150 microsec. The maximum energy density is 1.3 microjoule per cu cm.

  15. Chloride Channel Myotonia: Study of Five Cases

    Directory of Open Access Journals (Sweden)

    M Ghofrani

    2002-09-01

    Full Text Available Chloride channel Myotonia is a form of channelopathy, and Myotonia is its manifestation. Myotonia may be defined as delayed relaxation of skeletal muscle after its contraction. Decreased chloride conductance across the transverse tubular system, renders the muscle membrane hyper-excitable and leads to repetitive firing, creating Myotonia. Myotonia congenital is another name for chloride channel Myotonia. Myotonia congenital appears in autosomal dominant type called Thomson disease, autosomal recessive type called Becker disease, and a type with sporadic occurrence. Symptoms appear in the first or second decade of life. Repeated muscle contraction, the so called warm up, result in resolution of the Myotonia stiffness. Muscle stiffness and hypertrophy is another finding at physical examination. In this study we report on 5 patients, which had clinical and electrical signs of Myotonia. Muscle hypertrophy and warm up phenomena were present in all cases. CPK measurement of all cases were normal. 2 patients underwent muscle biopsy that showed only atrophy and increased central nuclei. In three cases autosomal recessive inheritance (Becker, in one case autosomal dominant inheritance (Thomsen and in one case sporadic occurrence was suggested. With respect to successful results of carbamazepine therapy in 4 patients, and being excellent in one of them, we suggest carbamazepine for the first choice of Myotonia treatment.

  16. An autopsy case of zinc chloride poisoning.

    Science.gov (United States)

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

    2016-07-01

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

  17. Potassium chloride production by microcline chlorination

    International Nuclear Information System (INIS)

    Highlights: • Use of chlorination for the KCl production. • The reagents used were microcline, hydromagnesite and chlorine. • Isothermal and non-isothermal assays were performed in Cl2–N2 mixture. • The chlorination generated KCl at 700 °C. • The chlorination products promote KCl formation. - Abstract: The potassium chloride is one of the most important fertilizers used in agriculture. The current demand of this salt makes interesting the study of potassium chloride production from unconventional potassium resources. In this work the potassium chloride production by chlorination of microcline was investigated. The starting reagents were microcline, hydromagnesite and chlorine. Non-isothermal and isothermal chlorination assays were carried out in a thermogravimetric device adapted to work in corrosive atmospheres. The temperature effect on potassium extraction and the phase transformations produced during chlorination of microcline were studied. The reagents and reaction products were analyzed by X-ray fluorescence (XRF) and X-ray diffraction (XRD). The experimental results indicated that by chlorination of microcline an important extraction of potassium in the temperature range from 800 to 900 °C was produced. Moreover, at 800 °C the forsterite, enstatite and magnesium aluminate spinel phases were generated

  18. Microwave spectrum and structure of nitrosyl chloride

    International Nuclear Information System (INIS)

    The microwave spectra of 15N isotopic species of nitrosyl chloride, 15NO35Cl and 15NO37Cl, have been assigned between 8 and 26 GHz, and the following rotational constants have been obtained: A = 81600 MHz, B = 5693.80 MHz, and C = 5322.44 MHz for 15NO35Cl, A = 81520 MHz, B = 5556.07 MHz, and C = 5201.56 MHz for 15NO37Cl. The microwave spectra of the normal species of nitrosyl chloride as well as the 37Cl species and the 18O species have already been measured by Millen et al. (1961). An analysis of both the rotational constants obtained in this study and the constants by Millen et al. has given the following bond lengths and angle as the complete r sub(s) structural parameters of nitrosyl chloride. r(N-O) = 1.143 +- 0.006 A, r(N-Cl) = 1.973 +- 0.003 A, and 0 +- 0.50. The nuclear quadrupole coupling constants in the N-Cl bond axis system of 15NO35Cl are X sub(zz) = -57.8 MHz and eta = -0.311. (author)

  19. Boldine action against the stannous chloride effect.

    Science.gov (United States)

    Reiniger, I W; Ribeiro da Silva, C; Felzenszwalb, I; de Mattos, J C; de Oliveira, J F; da Silva Dantas, F J; Bezerra, R J; Caldeira-de-Araújo, A; Bernardo-Filho, M

    1999-12-15

    Peumus boldus extract has been used in popular medicine in the treatment of biliar litiase, hepatic insufficiency and liver congestion. Its effects are associated to the substance boldine that is present in its extract. In the present work, we evaluated the influence of boldine both in: (i) the structural conformation of a plasmid pUC 9.1 through gel electrophoresis analysis; and in (ii) the survival of the strain of Escherichia coli AB1157 submitted to reactive oxygen species (ROS), generated by a Fenton like reaction, induced by stannous chloride. Our results show a reduction of the lethal effect induced by stannous chloride on the survival of the E. coli culture in the presence of boldine. The supercoiled form of the plasmid is not modified by stannous chloride in the presence of boldine. We suggest that the protection induced by boldine could be explained by its anti-oxidant mechanism. In this way, the boldine could be reacting with stannous ions, protecting them against the oxidation and, consequently, avoiding the generation of ROS. PMID:10624900

  20. Potassium chloride production by microcline chlorination

    Energy Technology Data Exchange (ETDEWEB)

    Orosco, Pablo, E-mail: porosco@unsl.edu.ar [Instituto de Investigaciones en Tecnología Química (INTEQUI), Chacabuco y Pedernera, San Luis (Argentina); Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis, Chacabuco y Pedernera, San Luis (Argentina); Ruiz, María del Carmen [Instituto de Investigaciones en Tecnología Química (INTEQUI), Chacabuco y Pedernera, San Luis (Argentina)

    2015-08-10

    Highlights: • Use of chlorination for the KCl production. • The reagents used were microcline, hydromagnesite and chlorine. • Isothermal and non-isothermal assays were performed in Cl{sub 2}–N{sub 2} mixture. • The chlorination generated KCl at 700 °C. • The chlorination products promote KCl formation. - Abstract: The potassium chloride is one of the most important fertilizers used in agriculture. The current demand of this salt makes interesting the study of potassium chloride production from unconventional potassium resources. In this work the potassium chloride production by chlorination of microcline was investigated. The starting reagents were microcline, hydromagnesite and chlorine. Non-isothermal and isothermal chlorination assays were carried out in a thermogravimetric device adapted to work in corrosive atmospheres. The temperature effect on potassium extraction and the phase transformations produced during chlorination of microcline were studied. The reagents and reaction products were analyzed by X-ray fluorescence (XRF) and X-ray diffraction (XRD). The experimental results indicated that by chlorination of microcline an important extraction of potassium in the temperature range from 800 to 900 °C was produced. Moreover, at 800 °C the forsterite, enstatite and magnesium aluminate spinel phases were generated.

  1. Solubility of sodium chloride in superheated steam

    International Nuclear Information System (INIS)

    The solubility of sodium chloride in superheated steam was investigated in laboratory-scale experiments up to 20 MPa and 475 C. These experiments were carried out using a dynamic method where deionized steam was passed through a packed bed of salt crystals in a 500 mL Hastelloy autoclave. The residence time of the steam in the salt bed was sufficient to saturate the steam with the salt. The steam samples were cooled and analyzed by ion chromatography. Correlations based on temperature and density were selected to describe the solubility of sodium chloride in superheated steam. The density dependence is much stronger than the temperature dependence. By using these correlations, it is possible to estimate the solubility of salt in steam at lower densities than those used in the experiments. Enthalpy-entropy diagrams are given that show the steam expansion line in turbines, including curves for constant concentration of sodium chloride solubility in steam. These can be used to analyze where in the steam cycle this salt may deposit. (orig.)

  2. The Accelerated Test of Chloride Permeability of Concrete

    Institute of Scientific and Technical Information of China (English)

    TAN Ke-feng; ODD E Gjφrv

    2003-01-01

    The availability of accelerated chloride permeability test and the effect of w/c ratio, incorporation of silica fume, maximum aggregate size and aggregate type on the chloride permeability were studied. The mathematic analysis certifies that there is a linear relationship between accelerated test and natural diffusion. Test results show that the chloride permeability of concrete increases as w/c ratio increases whilst a limited amount of replacement of cement with silica fume, the chloride permeability decreases dramatically. The maximum aggregate size in the range of 8 to 25 mm seems also affect chloride permeability but with a much less significant level. The chloride permeability of silica fume lightweight aggregate concrete is very low, especially the concrete made with dry lightweight concrete. The chloride permeability can be evaluated by this accelerated test method.

  3. Diffusion of tritiated water and chloride in basalt-bentonite mixtures

    International Nuclear Information System (INIS)

    Effective diffusion coefficients of tritiated water and chloride (/sup 36/Cl) were measured in mixtures of crushed basalt and bentonite as functions of temperature (20 to 900C) and mixture bulk density (1.5 to 1.9 Mg/m/sup 3/). A quick-freeze technique was used to halt the diffusion process so the tracer distributions could be determined by slicing the core and analyzing slices by liquid scintillation methods. Linear and multiple-linear regression analyses were performed on both data sets. The regression equations were then used to predict diffusion coefficient values outside the range of densities used in these experiments. The predicted values agree very well with published data. Correlation of diffusion coefficients with temperature was highly significant for both elements. Dependence of chloride diffusion on clay density was much larger than for tritium

  4. Relation between chloride exchange diffusion and a conductive chloride pathway across the isolated skin of the toad (Bufo bufo)

    DEFF Research Database (Denmark)

    Kristensen, P; Larsen, Erik Hviid

    1978-01-01

    Substitution of chloride in the outside bathing medium of the toad skin with bromide, iodide, nitrate and sulphate leads to a reduction in the apparent exchange diffusion of chloride across this tissue, and also to a reduction of the chloride current recorded during hyperpolarization. A series of...... systems could be explained as secondary effects due to a primary interaction with the sodium transport mechanisms. A correlation was found between the clamping current recorded during hyperpolarization and the efflux of chloride under short circuit conditions with chloride Ringer's on both sides. On the...

  5. Secretion by the nasal salt glands of two insectivorous lizard species is initiated by an ecologically relevant dietary ion, chloride.

    Science.gov (United States)

    Hazard, Lisa C; Lechuga, Claudia; Zilinskis, Stephanie

    2010-08-01

    Salt glands are used by some vertebrates to excrete hyperosmotic NaCl or KCl solutions in response to dietary salt loads. Control of secretion varies across taxa; some secrete in response to osmotic challenges while others secrete in response to specific dietary ions. We hypothesized that differences in control could be related to different diet-related selective pressures on herbivorous, marine, and insectivorous species. We studied control of secretion and flexibility of cation (sodium or potassium) and anion (chloride or bicarbonate) secretion in two insectivorous lizard species, Schneider's skinks (Eumeces schneideri, Scincidae) and green anoles (Anolis carolinensis, Polychrotidae). Lizards were injected daily for four days with combinations of cations (potassium, sodium, and histidine control) and anions (chloride and acetate control), isoosmotic saline, or sham injection. Secretions were collected daily and analyzed for sodium, potassium, and chloride. Both species secreted only in response to chloride; sodium appeared to have a slight inhibitory effect. Regardless of cation load, skinks secreted a combination of potassium and sodium, while anoles secreted solely potassium. In both species, total cation secretion was matched closely by chloride; very little bicarbonate was secreted. As predicted, secretion in insectivorous lizards was initiated by the dietary ion ecologically most important for these species, chloride, which otherwise cannot be excreted without significant water loss (unlike the cations, which may be excreted as insoluble urate salts). This gives further support to the hypothesis that ecological factors drive the evolution of control mechanisms in lizard salt glands. PMID:20623801

  6. Evaluation of DUSTRAN Software System for Modeling Chloride Deposition on Steel Canisters

    Energy Technology Data Exchange (ETDEWEB)

    Tran, Tracy T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Jensen, Philip J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Fritz, Brad G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Rutz, Frederick C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Devanathan, Ram [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-07-29

    The degradation of steel by stress corrosion cracking (SCC) when exposed to atmospheric conditions for decades is a significant challenge in the fossil fuel and nuclear industries. SCC can occur when corrosive contaminants such as chlorides are deposited on a susceptible material in a tensile stress state. The Nuclear Regulatory Commission has identified chloride-induced SCC as a potential cause for concern in stainless steel used nuclear fuel (UNF) canisters in dry storage. The modeling of contaminant deposition is the first step in predictive multiscale modeling of SCC that is essential to develop mitigation strategies, prioritize inspection, and ensure the integrity and performance of canisters, pipelines, and structural materials. A multiscale simulation approach can be developed to determine the likelihood that a canister would undergo SCC in a certain period of time. This study investigates the potential of DUSTRAN, a dust dispersion modeling system developed by Pacific Northwest National Laboratory, to model the deposition of chloride contaminants from sea salt aerosols on a steel canister. Results from DUSTRAN simulations run with historical meteorological data were compared against measured chloride data at a coastal site in Maine. DUSTRAN’s CALPUFF model tended to simulate concentrations higher than those measured; however, the closest estimations were within the same order of magnitude as the measured values. The decrease in discrepancies between measured and simulated values as the level of abstraction in wind speed decreased suggest that the model is very sensitive to wind speed. However, the influence of other parameters such as the distinction between open-ocean and surf-zone sources needs to be explored further. Deposition values predicted by the DUSTRAN system were not in agreement with concentration values and suggest that the deposition calculations may not fully represent physical processes. Overall, results indicate that with parameter

  7. Evaluation of DUSTRAN Software System for Modeling Chloride Deposition on Steel Canisters

    International Nuclear Information System (INIS)

    The degradation of steel by stress corrosion cracking (SCC) when exposed to atmospheric conditions for decades is a significant challenge in the fossil fuel and nuclear industries. SCC can occur when corrosive contaminants such as chlorides are deposited on a susceptible material in a tensile stress state. The Nuclear Regulatory Commission has identified chloride-induced SCC as a potential cause for concern in stainless steel used nuclear fuel (UNF) canisters in dry storage. The modeling of contaminant deposition is the first step in predictive multiscale modeling of SCC that is essential to develop mitigation strategies, prioritize inspection, and ensure the integrity and performance of canisters, pipelines, and structural materials. A multiscale simulation approach can be developed to determine the likelihood that a canister would undergo SCC in a certain period of time. This study investigates the potential of DUSTRAN, a dust dispersion modeling system developed by Pacific Northwest National Laboratory, to model the deposition of chloride contaminants from sea salt aerosols on a steel canister. Results from DUSTRAN simulations run with historical meteorological data were compared against measured chloride data at a coastal site in Maine. DUSTRAN's CALPUFF model tended to simulate concentrations higher than those measured; however, the closest estimations were within the same order of magnitude as the measured values. The decrease in discrepancies between measured and simulated values as the level of abstraction in wind speed decreased suggest that the model is very sensitive to wind speed. However, the influence of other parameters such as the distinction between open-ocean and surf-zone sources needs to be explored further. Deposition values predicted by the DUSTRAN system were not in agreement with concentration values and suggest that the deposition calculations may not fully represent physical processes. Overall, results indicate that with parameter

  8. High levan production by Bacillus licheniformis NS032 using ammonium chloride as the sole nitrogen source.

    Science.gov (United States)

    Kekez, B D; Gojgic-Cvijovic, G D; Jakovljevic, D M; Stefanovic Kojic, J R; Markovic, M D; Beskoski, V P; Vrvic, M M

    2015-03-01

    In this study, levan production by Bacillus licheniformis NS032 isolated from a petroleum sludge sample was investigated. High levan yield was obtained in a wide range of sucrose concentrations (up to 400 g/L) and, contrary to most levan-producing strains, using ammonium chloride as the sole N source. Interaction between sucrose, ammonium chloride, and initial pH of the medium in a low sucrose (60-200 g/L) and a high sucrose (300-400 g/L) system was analyzed by response surface methodology. According to the calculated model in the low sucrose system, maximum predicted levan yield was 47.8 g/L (sucrose 196.8 g/L, ammonium chloride 2.4 g/L, pH 7.0), while in the high sucrose system, levan yield was 99.2 g/L (sucrose 397.6 g/L, ammonium chloride 4.6 g/L, pH 7.4). In addition, protective effect of microbial levan against copper toxicity to Daphnia magna is observed for the first time. The acute toxicity (48 h EC50) of copper decreased from 0.14 to 0.44 mg/L by levan in concentration of 50 ppm. PMID:25592434

  9. Durability of sea-sand containing concrete: Effects of chloride ion penetration

    Institute of Scientific and Technical Information of China (English)

    Yin Huiguang; Li Yan; Lv Henglin; Gao Quan

    2011-01-01

    This paper describes an orthogonal experiment on the effect of water/cement ratio, water consumptionper cubic meter, curing time, and type of sand on the response "resistance to chloride ion penetration".A sea-sand containing concrete was used for the trials. An analysis of chloride ion diffusion coefficients at different factor levels was performed. A predictive model of chloride ion diffusion in concrete is developed through regression analysis. The experimental results show that when the water/cement ratio varies from 0.45 to 0.60, and the water consumption per cubic meter varies from 185 to 215 kg. and the curing time varies from 30 to 180 d then the size of the effects fall in the order (most significant first):curing time, type of sand, water consumption per cubic meter, and water/cement ratio. Chloride ion penetration is reduced, and better durability of the concrete is observed, with longer curing times, less water consumption per cubic meter, and a smaller water/cement ratio.

  10. Durability assessment of concrete bridge deck considering waterproof membrane and epoxy-coated reinforcement

    OpenAIRE

    Petr Konečný; Petr Lehner

    2016-01-01

    The effect of waterproof membrane and steel reinforcement protection on the concrete bridge deck is modeled. The attention is paid to the durability prediction related to steel reinforcement corrosion initiation based on the chloride penetration. Thus 2-D finite element chloride ingress model is applied. The transient finite element model serves to solve Fick's second diffusion law using the computer tool compatible with the Matlab environment. The model focuses on the transport of chloride i...

  11. Molecular mechanisms of carcinogenesis by vinyl chloride.

    Science.gov (United States)

    Dogliotti, Eugenia

    2006-01-01

    In 1974 vinyl chloride (VC), a gas used in the plastics industry, was shown to be a human carcinogen, inducing a very rare type of tumor, angiosarcoma of the liver. The same type of tumor was induced in rodents exposed to VC thus providing an excellent model for mechanistic studies. Here, we review the numerous studies on the mechanism of action of VC with particular emphasis on the DNA products induced by this strong alkylating agent. In particular, the genotoxicity, repair mechanisms, in vivo formation and tumor mutation spectra by etheno-adducts will be analysed and possible approaches for future research suggested. PMID:17033136

  12. Solidification of supercooled molten zinc chloride

    Czech Academy of Sciences Publication Activity Database

    Rodová, Miroslava; Cihlář, Antonín; Nitsch, Karel

    Bratislava: x, 2005 - (Koman, M.; Mikloš, D.), s. 5-9 ISBN 80-89088-42-2. [Development of Materials Science in Research and Education - DMS -RE 2005 /15./. Kežmarské Žĺaby (SK), 05.09.2005-09.09.2005] R&D Projects: GA ČR(CZ) GA202/03/0428 Institutional research plan: CEZ:AV0Z10100521 Keywords : molten zinc chloride * thermal analysis * crystallization * glass formation Subject RIV: BM - Solid Matter Physics ; Magnetism

  13. Benzalkonium Chloride Intoxication Mimicking Herpes Zoster Encephalitis

    Directory of Open Access Journals (Sweden)

    Ekrem Güler

    2011-06-01

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

  14. Chloride regulates afferent arteriolar contraction in response to depolarization

    DEFF Research Database (Denmark)

    Hansen, P B; Jensen, B L; Skott, O

    1998-01-01

    afferent arterioles. In 70% of vessels examined, K+-induced contraction was abolished by acute substitution of bath chloride. Consecutive addition of Cl- (30, 60, 80, 100, 110, and 117 mmol/L) restored the sensitivity to K+, and half-maximal response was observed at 82 mmol/L chloride. The calcium channel...... results show that K+-induced contraction of smooth muscle cells in the afferent arteriole is highly sensitive to chloride, whereas neurotransmitter release and ensuing contraction is not dependent on chloride. Thus, there are different activation pathways for depolarizing vasoconstrictors and for the......-Renal vascular reactivity is influenced by the level of dietary salt intake. Recent in vitro data suggest that afferent arteriolar contractility is modulated by extracellular chloride. In the present study, we assessed the influence of chloride on K+-induced contraction in isolated perfused rabbit...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-05-13

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

  16. Damage development, phase changes, transport properties, and freeze-thaw performance of cementitious materials exposed to chloride based salts

    Science.gov (United States)

    Farnam, Yaghoob

    Recently, there has been a dramatic increase in premature deterioration in concrete pavements and flat works that are exposed to chloride based salts. Chloride based salts can cause damage and deterioration in concrete due to the combination of factors which include: increased saturation, ice formation, salt crystallization, osmotic pressure, corrosion in steel reinforcement, and/or deleterious chemical reactions. This thesis discusses how chloride based salts interact with cementitious materials to (1) develop damage in concrete, (2) create new chemical phases in concrete, (3) alter transport properties of concrete, and (4) change the concrete freeze-thaw performance. A longitudinal guarded comparative calorimeter (LGCC) was developed to simultaneously measure heat flow, damage development, and phase changes in mortar samples exposed to sodium chloride (NaCl), calcium chloride (CaCl 2), and magnesium chloride (MgCl2) under thermal cycling. Acoustic emission and electrical resistivity measurements were used in conjunction with the LGCC to assess damage development and electrical response of mortar samples during cooling and heating. A low-temperature differential scanning calorimetry (LT-DSC) was used to evaluate the chemical interaction that occurs between the constituents of cementitious materials (i.e., pore solution, calcium hydroxide, and hydrated cement paste) and salts. Salts were observed to alter the classical phase diagram for a salt-water system which has been conventionally used to interpret the freeze-thaw behavior in concrete. An additional chemical phase change was observed for a concrete-salt-water system resulting in severe damage in cementitious materials. In a cementitious system exposed to NaCl, the chemical phase change occurs at a temperature range between -6 °C and 8 °C due to the presence of calcium sulfoaluminate phases in concrete. As a result, concrete exposed to NaCl can experience additional freeze-thaw cycles due to the chemical

  17. Surface Chloride Concentration of Concrete under Shallow Immersion Conditions

    OpenAIRE

    Jun Liu; Kaifeng Tang; Dong Pan; Zongru Lei; Weilun Wang; Feng Xing

    2014-01-01

    Deposition of chloride ions in the surface layer of concrete is investigated in this study. In real concrete structure, chloride ions from the service environment can penetrate into concrete and deposit in the surface layer, to form the boundary condition for further diffusion towards the interior. The deposit amount of chloride ions in the surface layer is normally a function of time, rather than a constant. In the experimental investigation, concrete specimens with different mix proportions...

  18. Chemical aspects of hydrogen ingress in zirconium and zircaloy pressure tubes: ageing management of Indian PHWR coolant channels - determination of hydrogen and deuterium

    International Nuclear Information System (INIS)

    Pressurized heavy water reactors (PHWRs) use zirconium and zirconium based alloys as clad and coolant tubes since its beginning. The first ever zircaloy-2 pressure tube failure occurred in 1983 at Ontario Hydro's Pickering Unit 2 in Canada which necessitated a thorough examination of causes of such failure. The failure was attributed to massive hydriding at the failed spot of pressure tube. Continuous usage of zirconium alloys could result in their hydrogen and deuterium pick-up leading to hydrogen/ deuterium embrittlement. The life of the zircaloy coolant channels is dictated by hydrogen/deuterium content and hence ageing management of the pressure tubes is essential for ensuring their trouble-free usage. It is desirable to have a sound knowledge on the chemical aspects of zirconium and zirconium based alloys metallurgy, the mechanistic principles of hydrogen ingress into the pressure tubes during in reactor service, and identifying suitable analytical methodologies for precise and accurate determination of hydrogen in wafer thin sliver samples carved out from insides of pressure tubes without causing any structural damage so that it can continue to remain in service. This is desirable so that the ageing management does not result in cost-escalation. This report is divided in to three main parts. The first part deals with the chemical aspects of zirconium and zirconium based alloy metallurgy, the mechanism of hydrogen pick-up and hydride formation in zirconium matrix. The second part describes various methodologies and their limitations, available for hydrogen/deuterium determination. The third part deals in detail, about the extensive investigations carried out at Radioanalytical Chemistry Division (RACD) in Radiochemistry and Isotope Group for establishing an indigenously developed hot vacuum extraction system in combination with quadrupole mass spectrometry for precise determination of hydrogen and deuterium in wafer thin sliver sample of zircaloy. The

  19. N,N-Dimethyldehydroabietylammonium chloride ethanol monosolvate

    Directory of Open Access Journals (Sweden)

    Xiu-Zhi Huang

    2013-06-01

    Full Text Available The title compound {systematic name: 1-[(1R,4aS,10aR-7-isopropyl-1,4a-dimethyl-1,2,3,4,4a,9,10,10a-octahydrophenanthren-1-yl]-N,N-dimethylmethanaminium chloride ethanol monosolvate}, C22H36N+·Cl−·C2H6O, was synthesized from dehydroabietylamine by N-methylation with formaldehyde/formic acid and transformation into the hydrochloride. The dehydroabietyl moiety exhibits the usual conformation with the two cyclohexane rings in chair and half-chair conformations and a trans-ring junction. The crystal structure is built up from columns of the dehydroabietyl moieties stacked along the a axis. These columns are held together by the chloride ions via N—H...Cl and C—H...Cl interactions, which establish a two-dimensional network parallel to (010. The ethanol solvent molecules are located between the columns and anchored via O—H...Cl hydrogen bonds.

  20. Radiolytic preparation of anhydrous tin (2) chloride

    Science.gov (United States)

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

    1973-01-01

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

  1. Synthesis and structure characterization of diethyldiallylammonium chloride

    Institute of Scientific and Technical Information of China (English)

    刘立华; 龚竹青; 郑雅杰

    2003-01-01

    The unsaturated quaternary ammonium salt diethyldiallylammonium chloride(DEDAAC) was synthesized in a two-step synthetic method. The influences of the adding method of raw materials and temperature on the yields of diethylallylamine (DEAA), and drying and temperature on the synthesis of DEDAAC were investigated. The content of in-process product DEAA was determined by non-aqueous titration. The structure of product DEDAAC was identified with IR, 1 H NMR and elemental analysis. The results show that adding allyl chloride and sodium hydroxide alternately can increase the yield of DEAA and decrease by-products. In further synthesizing of DEDAAC from DEAA, the step of drying DEAA is very necessary. When DEAA is dried by solid sodium hydroxide, good columnar crystals with a high purity(mp 199.5-201.0 ℃) are obtained; when DEAA is undried or the content of water in DEAA is above 20%, only platelets with bad quality are obtained even without crystals. The suitable synthesis conditions for DEAA and DEDAAC are 35 ℃, 6 h and 40 ℃, 36 h, respectively, and their yields are 69.7% and 67.3%, respectively.

  2. Cobalt electrodeposition using urea and choline chloride

    International Nuclear Information System (INIS)

    The electrochemical behavior of Co(II) in urea-choline chloride-CoCl2 melt was investigated by cyclic voltammetry at 373 K. The results show that the reaction of Co(II) to Co is irreversible and it proceeds via a one-step two electrons transfer process. The diffusion coefficient of Co(II) was estimated to be 1.7 × 10−6 cm2 s−1 at 373 K. Electrodeposition of cobalt was studied at different cathodic potentials (-0.80 to -0.95 V) and at different temperatures (353 to 383 K) in eutectic mixture of choline chloride and urea (1:2 molar ratio). The deposits were characterized using scanning electron microscope (SEM), energy-dispersive spectroscopy (EDS), and X-ray diffraction (XRD). SEM images show that uniform, dense, and compact deposits were obtained at -0.80 V within a temperature range of 353 K to 373 K. EDS and XRD analysis confirm that high-purity metallic Co deposits were obtained

  3. The electrodeposition of lead from chloride electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Wright, A.

    1986-11-28

    At low current densities, lead was deposited onto a lead substrate as a fine powder that did not adhere well to the substrate. At higher current densities dendritic growth occurred. Lead does not adhere to a graphite substrate and, since copper and titanium substrates require higher cell voltages than lead substrates, these three substrates were rejected. The temperature of the electrolyte must be maintained above 69/sup 0/C to avoid the precipitation of lead chloride in the cell. Optimum current efficiencies at the anode and cathode were obtained at 80/sup 0/C, and no improvement in the morphology of the deposit was observed at higher temperatures. A combination of Quebracho extract and cuprous ions achieved the greatest improvement in the morphology of the deposit, while maintaining high current efficiencies at the anode and cathode. However, when the deposition time was increased, dendritic growth was much in evidence. A compact, adherent deposit of lead could not be obtained from chloride electrolytes. 22 refs., 21 figs., 11 tabs.

  4. Open cycle lithium chloride cooling system

    Science.gov (United States)

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

    1983-05-01

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

  5. Fault locator of an allyl chloride plant

    Directory of Open Access Journals (Sweden)

    Savković-Stevanović Jelenka B.

    2004-01-01

    Full Text Available Process safety analysis, which includes qualitative fault event identification, the relative frequency and event probability functions, as well as consequence analysis, was performed on an allye chloride plant. An event tree for fault diagnosis and cognitive reliability analysis, as well as a troubleshooting system, were developed. Fuzzy inductive reasoning illustrated the advantages compared to crisp inductive reasoning. A qualitative model forecast the future behavior of the system in the case of accident detection and then compared it with the actual measured data. A cognitive model including qualitative and quantitative information by fuzzy logic of the incident scenario was derived as a fault locator for an ally! chloride plant. The obtained results showed the successful application of cognitive dispersion modeling to process safety analysis. A fuzzy inductive reasoner illustrated good performance to discriminate between different types of malfunctions. This fault locator allowed risk analysis and the construction of a fault tolerant system. This study is the first report in the literature showing the cognitive reliability analysis method.

  6. Estimation of trace chloride in nuclear grade sodium

    International Nuclear Information System (INIS)

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

  7. 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. PMID:27105154

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

    DEFF Research Database (Denmark)

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

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

  9. 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.

  10. Meso-scale modeling of chloride diffusion in concrete with consideration of effects of time and temperature

    OpenAIRE

    Li-cheng WANG; Ueda, Tamon

    2009-01-01

    A meso-scale truss network model was developed to predict chloride diffusion in concrete. The model regards concrete as a three-phase composite of mortar matrix, coarse aggregates, and the interfacial transition zone (ITZ) between the mortar matrix and the aggregates. The diffusion coefficient of chloride in the mortar and the ITZ can be analytically determined with only the water-to-cement ratio and volume fraction of fine aggregates. Fick’s second law of diffusion was used as the governing ...

  11. Effect of application of ammonium chloride and calcium chloride on alfalfa cation-anion content and yield.

    Science.gov (United States)

    Goff, J P; Brummer, E C; Henning, S J; Doorenbos, R K; Horst, R L

    2007-11-01

    A major factor predisposing the cow to periparturient hypocalcemia, or milk fever, is being fed a prepartum ration with a high dietary cation-anion difference (DCAD). The DCAD can be favorably altered to prevent milk fever by decreasing K and Na or increasing Cl and S in forages for cows in late gestation. The objective of this study was to test the hypothesis that application of Cl to alfalfa could increase Cl in forage, thereby lowering DCAD. We conducted a field experiment at 2 Iowa locations in which established plots of alfalfa were treated in April 2001 with 0, 56, 112, or 168 kg of Cl/ha using ammonium chloride, calcium chloride, or a mix of the 2 sources with equal amounts of chloride coming from each source. Plots were harvested 4 times in 2001 and once in 2002 and plant tissue analyzed for mineral composition. Applying chloride from either source once in the spring resulted in increased plant chloride content over all 4 cuttings for that year. Averaged across both locations, chloride levels were elevated from 0.52% in control plots to 0.77, 0.87, and 0.89% Cl in plots treated with 56, 112, and 168 kg of Cl/ha, respectively. Chloride application had no effect on plant potassium, sodium, calcium, magnesium, or phosphorus. These results suggest chloride application can elevate chloride content and lower DCAD values of alfalfa, and also maintain crop yield. PMID:17954756

  12. THE COMPATIBILITY OF BLENDS OF POLY(VINYL CHLORIDE) OR CHLORINATED POLY(VINYL CHLORIDE) WITH POLY(METHYL METHACRYLATE)

    Institute of Scientific and Technical Information of China (English)

    WANG Qingguo; CHENG Rongshi

    1988-01-01

    IR spectral shifts of carbonyl vibrational absorption for ethyl acetate, which acts analogically as the structural unit of poly(methyl methacrylate), in cyclohexane, chloroform, chlorinated paraffins, poly(vinyl chloride) and chlorinated poly(vinyl chloride) were measured. The results suggest that there are specific interactions between the carbonyl groups and the chlorinated hydrocarbons which could be responsible for the apparent compatibility of poly(vinyl chloride) -poly(methyl methacrylate) and chlorinated poly(vinyl chloride) -poly(methyl methacrylate) blends. Additionally, the effects of the preparation mode of blend films on phase separation and observed compatibility are discussed.

  13. Aspects of the magnetism of ferrous chloride

    International Nuclear Information System (INIS)

    This work is a critical review of the existing work on ferrous chloride and presents, as well, a number of new experimental results. First, a careful analysis of the level structure of ferrous ions in the crystalline field shows that the crystalline anisotropy is of the same order of magnitude as the exchange interactions, a feature which gives rise to some particular effects, such as an upward curvature of the magnetization curve at 0 K in a perpendicular magnetic field. Further, the very low temperature (T > 0.4 K) thermal variation of both the specific heat and magnetic susceptibility evidences a magnetic component in elementary excitations. This result suggests the presence of a large magneto-elastic coupling. Finally, an experimental study of the H-T phase diagram near TN and of the critical behaviour of the specific heat and parallel susceptibility was performed. (author)

  14. Phosphates behaviours in conversion of FP chlorides

    International Nuclear Information System (INIS)

    The spent electrolyte of the pyroprocessing by metal electrorefining method should be considered for recycling after removal of fission products (FP) such as, alkali metals (AL), alkaline earth metals (ALE), and/or rare earth elements (REE), to reduce the volume of high-level radioactive waste. Among the various methods suggested for this purpose is precipitation by converting FP from chlorides to phosphates. Authors have been carrying out the theoretical analysis and experiment showing the behaviours of phosphate precipitates so as to estimate the feasibility of this method. From acquired results, it was found that AL except lithium and ALE are unlikely to form phosphate precipitates. However their conversion behaviours including REE were compatible with the theoretical analysis; in the case of LaPO4 as one of the REE precipitates, submicron-size particles could be observed while that of Li3PO4 was larger; the precipitates were apt to grow larger at higher temperature; etc.

  15. 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.

  16. Durability Evolution of RC Bridge under Coupling Action of Chloride Corrosion and Carbonization Based on DLA Model

    Directory of Open Access Journals (Sweden)

    Haoxiang He

    2015-01-01

    Full Text Available Chloride attack and carbonization are the main factors which affect the durability of concrete structures, and the respective theoretical models are systematically established. However, the quantitative analysis and models about the coupling effect of chloride attack and carbonization are less, so the precision and level of durability analysis of reinforced concrete are restricted. Diffusion-limited aggregation (DLA model can finely simulate the process of gas diffusion and condensation with randomness and fractal characteristics, which is suitable for revealing the durability evolution process of the chloride attack, carbonization, and the coupling action in concrete. Based on the principle of DLA, considering the factors such as diffusion depth, concrete properties, and exposure conditions which influence the characteristics of chloride diffusion and carbonization, as well as the coupling effect, an integrated DLA model is established. The concentration of carbon dioxide and chloride at any time and any location can be obtained and dynamically displayed based on the DLA model. The performance predict method for concrete and steel bars considering fatigue effect is presented based on DLA, according to the demand for bridge durability analysis. Numerical examples show that the method can dynamically and intensively simulate the durability evolution process of reinforced concrete bridge.

  17. Coordination compounds of transition metal chlorides with tetrazoles

    International Nuclear Information System (INIS)

    Coordination compounds (CC) of Co(2), Ni(2), Cu(2), Cd(2) chlorides with tetrazole and Ni(2) and Cd(2) chloride CC with tetrazolylhydrazone benzaldehyde are synthesized. The compounds are characterized by electron- and IR-spectroscopy, magnetic measurements (78-300 K), radiography. Conclusions are made on polynuclear structure of coordination compounds and Msup((2)) octahedron coordination

  18. Microwave Mapping Demonstration Using the Thermochromic Cobalt Chloride Equilibrium

    Science.gov (United States)

    Nguyen, Vu D.; Birdwhistell, Kurt R.

    2014-01-01

    An update to the thermochromic cobalt(II) chloride equilibrium demonstration is described. Filter paper that has been saturated with aqueous cobalt(II) chloride is heated for seconds in a microwave oven, producing a color change. The resulting pink and blue map is used to colorfully demonstrate Le Châtelier's principle and to illuminate the…

  19. Prostaglandin synthetase inhibitor in an infant with congenital chloride diarrhoea.

    OpenAIRE

    Minford, A M; Barr, D G

    1980-01-01

    Hyper-reninaemia, hypokaluria, and hypokalaemia in an infant with congenital chloride diarrhoea improved during treatment with a prostaglandin synthetase inhibitor, ketoprofen. There was evidence of increased activity of therenin-aldosterone system when ketoprofen was stopped. It is suggested that prostaglandins may be involved in stimulating the renin-aldosterone system in congenital chloride diarrhoea.

  20. Chlorides behavior in raw fly ash washing experiments

    International Nuclear Information System (INIS)

    Chloride in fly ash from municipal solid waste incinerators (MSWIs) is one of the obstructive substances in recycling fly ash as building materials. As a result, we have to understand the behavior of chlorides in recycling process, such as washing. In this study, we used X-ray absorption near edge structure (XANES) and X-ray diffraction (XRD) to study the chloride behavior in washed residue of raw fly ash (RFA). We found that a combination of XRD and XANES, which is to use XRD to identify the situation of some compounds first and then process XANES data, was an effective way to explain the chlorides behavior in washing process. Approximately 15% of the chlorine in RFA was in the form of NaCl, 10% was in the form of KCl, 51% was CaCl2, and the remainder was in the form of Friedel's salt. In washing experiments not only the mole percentage but also the amount of soluble chlorides including NaCl, KCl and CaCl2 decreases quickly with the increase of liquid to solid (L/S) ratio or washing frequency. However, those of insoluble chlorides decrease slower. Moreover, Friedel's salt and its related compound (11CaO.7Al2O3.CaCl2) were reliable standards for the insoluble chlorides in RFA, which are strongly related to CaCl2. Washing of RFA promoted the release of insoluble chlorides, most of which were in the form of CaCl2.

  1. Stability constants of the Europium complexes with the chloride ions

    International Nuclear Information System (INIS)

    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)

  2. Monte Carlo calculation of chloride diffusion in concrete

    International Nuclear Information System (INIS)

    Coefficient of chloride diffusion is calculated by applying the Fick's second law of diffusion to a chloride concentration profile. Then from the signal strength for various chlorine gamma-ray energies was then calculated at the detector of the portable D-D neutron generator based PGNAA setup. (author)

  3. Phosphatase inhibitors activate normal and defective CFTR chloride channels.

    OpenAIRE

    Becq, F; Jensen, T J; Chang, X B; Savoia, A.; Rommens, J M; Tsui, L C; Buchwald, M; Riordan, J R; Hanrahan, J W

    1994-01-01

    The cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel is regulated by phosphorylation and dephosphorylation at multiple sites. Although activation by protein kinases has been studied in some detail, the dephosphorylation step has received little attention. This report examines the mechanisms responsible for the dephosphorylation and spontaneous deactivation ("rundown") of CFTR chloride channels excised from transfected Chinese hamster ovary (CHO) and human airway epi...

  4. Contribution on creep polygonization study in crystals. Creep of single crystalline silver chloride and sodium chloride

    International Nuclear Information System (INIS)

    Subgrain formation and their influence on plastic behavior of materials has been studied in the case of single crystals of silver chloride and sodium chloride crept at high temperature (T > 0.5 Tmelting). It is shown that the creep rate ε is a function of the mean subgrain diameter d. For secondary creep ε ∝ dk with k = 2 for NaCl and AgCl. During secondary creep, the substructure changes continuously: sub-boundaries migrate and sub-grains rotate. We find that sub-boundaries migration accounts for 35 pc of the total strain and that subgrain misorientation θ increases linearly with strain ε: θ ∝ 0.14 ε. The stability of permanent creep seems related to the power that the substructure is able to dissipate. The possible subgrain formation mechanisms are examined. It is shown that subgrain formation is closely related to the geometrical conditions of deformation and to the heterogeneities of this later. (author)

  5. Monoclonal Antibodies to the Apical Chloride Channel in Necturus Gallbladder Inhibit the Chloride Conductance

    Science.gov (United States)

    Finn, Arthur L.; Tsai, Lih-Min; Falk, Ronald J.

    1989-10-01

    Monoclonal antibodies raised by injecting Necturus gallbladder cells into mice were tested for their ability to inhibit the apical chloride conductance induced by elevation of cellular cAMP. Five of these monoclonal antibodies bound to the apical cells, as shown by indirect immunofluorescence microscopy, and inhibited the chloride conductance; one antibody that bound only to subepithelial smooth muscle, by indirect immunofluorescence microscopy, showed no inhibition of chloride transport. The channel or a closely related molecule is present in the membrane whether or not the pathway is open, since, in addition to inhibiting the conductance of the open channel, the antibody also bound to the membrane in the resting state and prevented subsequent opening of the channel. The antibody was shown to recognize, by ELISA, epitopes from the Necturus gallbladder and small intestine. Finally, by Western blot analysis of Necturus gallbladder homogenates, the antibody was shown to recognize two protein bands of Mr 219,000 and Mr 69,000. This antibody should permit isolation and characterization of this important ion channel.

  6. Molten Chloride Salts for Heat Transfer in Nuclear Systems

    Science.gov (United States)

    Ambrosek, James Wallace

    2011-12-01

    A forced convection loop was designed and constructed to examine the thermal-hydraulic performance of molten KCl-MgCl2 (68-32 at %) salt for use in nuclear co-generation facilities. As part of this research, methods for prediction of the thermo-physical properties of salt mixtures for selection of the coolant salt were studied. In addition, corrosion studies of 10 different alloys were exposed to the KCl-MgCl2 to determine a suitable construction material for the loop. Using experimental data found in literature for unary and binary salt systems, models were found, or developed to extrapolate the available experimental data to unstudied salt systems. These property models were then used to investigate the thermo-physical properties of the LINO3-NaNO3-KNO 3-Ca(NO3), system used in solar energy applications. Using these models, the density, viscosity, adiabatic compressibility, thermal conductivity, heat capacity, and melting temperatures of higher order systems can be approximated. These models may be applied to other molten salt systems. Coupons of 10 different alloys were exposed to the chloride salt for 100 hours at 850°C was undertaken to help determine with which alloy to construct the loop. Of the alloys exposed, Haynes 230 had the least amount of weight loss per area. Nickel and Hastelloy N performed best based on maximum depth of attack. Inconel 625 and 718 had a nearly uniform depletion of Cr from the surface of the sample. All other alloys tested had depletion of Cr along the grain boundaries. The Nb in Inconel 625 and 718 changed the way the Cr is depleted in these alloys. Grain-boundary engineering (GBE) of Incoloy 800H improved the corrosion resistance (weight loss and maximum depth of attack) by nearly 50% as compared to the as-received Incoloy 800H sample. A high temperature pump, thermal flow meter, and pressure differential device was designed, constructed and tested for use in the loop, The heat transfer of the molten chloride salt was found to

  7. Caesium-137 Chloride Retention following Accidental Ingestion

    International Nuclear Information System (INIS)

    Four men became contaminated with caesium-137 chloride due to leaks in a 100 c source. The source was believed to be completely leak proof, since the caesium chloride was contained in a welded stainless-steel capsule which was covered with an outer steel jacket of standard Oak Ridge design. Most of the contamination occurred while the men were cleaning the components of a pneumatic device used to move the source. The most heavily- contaminated individual placed his mouth over the end of a transport tube and attempted to blow some ''dust'' out of the tube. The other men handled various parts of the transport mechanism and wiped ''dust'' out of holes with their fingers. None of the men washed their hands before eating lunch. When radioactive contamination was discovered on the following day, immediate efforts were made to decontaminate the men. Arrangements for whole-body counts were also made and, on the fifth day following contamination, the men reported to the Radiation Exposure Evaluation laboratory. The body burdens on the fifth day ranged from 35 - 970 nc of caesium-137. During the next five to six days the burdens dropped rapidly and on the eleventh day ranged from 28- 780 nc. After the eleventh day the body burdens of caesium-137 changed much more slowly. Whole-body counts made between the 11th and 160th day yielded biological half-lives of 76, 95 and 126 d for the three most heavily-contaminated individuals. During the period of rapid excretion all urine and faeces were collected and counted. These counts indicated a considerable superficial contamination prior to the eleventh day since only a portion of the removed caesium-137 was found in the urine and stool specimens. The body burdens of the four men are compared with normals of the same size, build, age and diet habits. A short discussion of normal burdens is included. A brief description of the counting system, data handling techniques and calibration procedures is also included. (author)

  8. Oxidation kinetics of innovative carbon materials with respect to severe air ingress accidents in HTRs and graphite disposal or processing; Oxidationskinetik innovativer Kohlenstoffmaterialien hinsichtlich schwerer Lufteinbruchstoerfaelle in HTR's und Graphitentsorgung oder Aufbereitung

    Energy Technology Data Exchange (ETDEWEB)

    Schloegel, Baerbel

    2010-07-01

    Currently future nuclear reactor concepts of the Fourth Generation (Gen IV) are under development. To some extend they apply with new, innovative materials developed just for this purpose. This thesis work aims at a concept of Generation IV Very High Temperature Reactors (VHTR) in the framework of the European project RAPHAEL (ReActor for Process heat, Hydrogen And ELectricity generation). The concept named ANTARES (AREVA New Technology based on advanced gas-cooled Reactors for Energy Supply) was developed by AEVA NP. It is a helium cooled, graphite moderated modular reactor for electricity and hydrogen production, by providing the necessary process heat due to its high working temperature. Particular attention is given here to oxidation kinetics of newly developed carbon materials (NBG-17) with still unknown but needed information in context of severe air ingress accident in VHTR's. Special interest is paid to the Boudouard reaction, the oxidation of carbon by CO{sub 2}. In case of an air ingress accident, carbon dioxide is produced in the primary reaction of atmospheric oxygen with reflector graphite. From there CO{sub 2} could flow into the reactor core causing further damage by conversion into CO. The purpose of this thesis is to ascertain if and to what degree this could happen. First of all oxidation kinetic data of the Boudouard reaction with NBG-17 is determined by experiments in a thermo gravimetric facility. The measurements are evaluated and converted into a common formula and a Langmuir-Hinshelwood similar oxidation kinetic equation, as input for the computer code REACT/THERMIX. This code is then applied to analyse severe air ingress accidents for several air flow rates. The results are discussed for two accident situations, in which a certain graphite burn off is achieved. All cases show much more damage to the graphite bottom reflector than to the reactor core. Thus the bottom reflector will lose its structural integrity much earlier than the

  9. Regulation of neuronal chloride homeostasis by neuromodulators.

    Science.gov (United States)

    Mahadevan, Vivek; Woodin, Melanie A

    2016-05-15

    KCC2 is the central regulator of neuronal Cl(-) homeostasis, and is critical for enabling strong hyperpolarizing synaptic inhibition in the mature brain. KCC2 hypofunction results in decreased inhibition and increased network hyperexcitability that underlies numerous disease states including epilepsy, neuropathic pain and neuropsychiatric disorders. The current holy grail of KCC2 biology is to identify how we can rescue KCC2 hypofunction in order to restore physiological levels of synaptic inhibition and neuronal network activity. It is becoming increasingly clear that diverse cellular signals regulate KCC2 surface expression and function including neurotransmitters and neuromodulators. In the present review we explore the existing evidence that G-protein-coupled receptor (GPCR) signalling can regulate KCC2 activity in numerous regions of the nervous system including the hypothalamus, hippocampus and spinal cord. We present key evidence from the literature suggesting that GPCR signalling is a conserved mechanism for regulating chloride homeostasis. This evidence includes: (1) the activation of group 1 metabotropic glutamate receptors and metabotropic Zn(2+) receptors strengthens GABAergic inhibition in CA3 pyramidal neurons through a regulation of KCC2; (2) activation of the 5-hydroxytryptamine type 2A serotonin receptors upregulates KCC2 cell surface expression and function, restores endogenous inhibition in motoneurons, and reduces spasticity in rats; and (3) activation of A3A-type adenosine receptors rescues KCC2 dysfunction and reverses allodynia in a model of neuropathic pain. We propose that GPCR-signals are novel endogenous Cl(-) extrusion enhancers that may regulate KCC2 function. PMID:26876607

  10. Design of zirconium tetra chloride purification apparatus

    International Nuclear Information System (INIS)

    Design of zirconium tetrachloride purification apparatus was done. The purification was done by sublimation and desublimation of zirconium tetrachloride compound. Zirconium tetrachloride,which was produced by the chlorination processes, was sublimated at 600oC then was desublimated at 331oC. The impurities could be separated. Zirconium tetra chloride was put at the tray in the column heated by the furnace, so that it sublimated. Ferri and Chromi salt was reduced to be ferro and chromo which could not be sublimated. Desublimation, was done in the cooler from pipe which was flowed by water. Cooler mode from 6 pieces of pipe, 1/4 inch in diameter and 30 cm in length. The water flow was 2.8 l/minute. Air was entered in the annulus surrounding the column. From the 80 cm length of the column, 50 cm was used for sublimation, and 30 cm for desublimation. Heat requirement was supplied by a furnace outside of the column. Heat flux could be arranged by the controller. (author)

  11. Redetermination of 1-carboxycyclohexan-1-aminium chloride

    Directory of Open Access Journals (Sweden)

    Teresa González

    2009-02-01

    Full Text Available The crystal structure of the title compound, C7H14NO2+·Cl−, was reported previously [Chacko, Srinivasan & Zand (1975. J. Cryst. Mol. Struct. 5, 353–357] from Weissenberg photographic data with R = 0.113. It has now been redetermined, providing a significant increase in the precision of the derived geometric parameters, viz. mean σ(C—C = 0.003 Å in the present work compared with 0.021 Å for the previous work. The complete cation is generated by crystallographic mirrror symmetry, with three C atoms, two O atoms and the N atom lying on the reflecting plane; the chloride anion also has m site symmetry. The crystal structure is established by a two-dimensional network of O—H...Cl and N—H...Cl hydrogen bonds, generating C12(4 and C12(7 chains, and R24(8 and R24(14 rings.

  12. NQR in tert-butyl chloride

    Science.gov (United States)

    Brunetti, Aldo H.

    2004-03-01

    Tert-butyl chloride has been broadly studied experimentally through various techniques such as X-ray crystallography, DTA, and NMR. It was also studied experimentally through nuclear quadrupole resonance (NQR), but this study was limited and incomplete. In this paper, we present a more detailed study of TBC through the NQR of 35Cl. Our results show that near 120 K, the onset of the CH 3 groups semirotations around symmetry axis C3 takes place with an activation energy U=16.1 kJ mol -1. This intramolecular movement produces a T1 minimum near 148 K and is the dominant mechanism of the nuclear spin-lattice relaxation in phase III of this compound. In phase II of TBC, we show that there are not only methyl groups semirotations, but also semirotations of the whole molecule around a different axis from the symmetry axis C' 3 (C-Cl bond) with an activation energy of E=10.4 kJ mol -1.

  13. Formation of plutonium phosphates in chloride melts

    Energy Technology Data Exchange (ETDEWEB)

    Burnaeva, A.A.; Kryukova, A.I.; Kazanstev, G' N.; Skiba, O.V.; Korshunov, I.A.

    1984-01-01

    Introduction of sodium- and potassium phosphates Na/sub 3/PO/sub 4/ and K/sub 3/PO/sub 4/ in the PuCl/sub 3/-NaCl, PuCl/sub 3/-KCl melts results in reduction of plutonium amount in the liquid phase. Low-soluble plutonium (3) phosphates, of assumed Na/sub 3/Pu/sub 2/ composition (PO/sub 4/)/sub 3/ are transported into the solid phase. Using the methods of radiographical and radiometric analyses the phases of plutonium phosphates separated by precipitation from chloride melt and also prepared from PuO/sub 2/ and NaH/sub 2/PO/sub 4/ at 1200 deg C are investigated. Their solubility in the NaCl-KCl melt and stability to these melts during a long-term contact, and also under the effect of CCl/sub 4/ are evaluated. The data are compared with similar data for thorium-, uranium-, americium-, curium-, zirconium-, rare earth phosphates.

  14. Durability Analysis of Subway Station in Chloride Environment

    Directory of Open Access Journals (Sweden)

    Yang LuFeng

    2013-02-01

    Full Text Available In this study, a finite element model for chloride ions transport in saturated concrete was proposed based on the Fick’s second law of diffusion. The governing partial differential equation was solved numerically in space as a boundary-value problem and in time as an initial-value problem by means of the finite element formulations. The maximum allowable value of chloride diffusion coefficient within different locations of subway station with service life of 100a was achieved and suggestions for durability analysis of subway station in chloride environment were also proposed.

  15. Molten Triazolium Chloride Systems as New Aluminum Battery Electrolytes

    DEFF Research Database (Denmark)

    Vestergaard, B.; Bjerrum, Niels; Petrushina, Irina;

    1993-01-01

    The possibility of using molten mixtures of 1,4-dimethyl-1,2,4-triazolium chloride (DMTC) and aluminum chloride (AlCl3) as secondary battery electrolytes was studied, in some cases extended by the copresence of sodium chloride. DMTC-AlCl, mixtures demonstrated high specific conductivity in a wide...... of milliamperes per square centimeter) was observed at 0.344 V on the acidic sodium tetrachloroaluminate background, involving a free triazolium radical mechanism. Molten DMTC-AlCl3 electrolytes are acceptable for battery performance and both the aluminum anode and the triazolium electrolyte can be...

  16. Denitrification of fertilizer wastewater at high chloride concentration

    DEFF Research Database (Denmark)

    Ucisik, Ahmed Süheyl; Henze, Mogens

    Wastewater from fertilizer industry is characterized by high contents of chloride concentration, which normally vary between 60 and 76 g/l. Experiments with bilogical denitrification were performed in lab-scale "fill and draw" reactors with synthetic wastewater with chloride concentrations up to 77.......4 g/l. The results of the experiments showed that biological denitrification was feasible at the extreme environmental conditions prevailing in fertilizer wastewater. Stable continuous biological denitrfication of the synthetic high chloride wastewater was performed up to 77.4 g Cl/l at 37 degree C...

  17. Alkyl substituent effect on density, viscosity and chemical behavior of 1-alkyl-3-methylimidazolium chloride.

    Science.gov (United States)

    Olmo, Lourdes del; Lage-Estebanez, Isabel; López, Rafael; García de la Vega, José M

    2014-09-01

    Molecular structure of the conformers of 1-C n -3-methylimidazolium chloride (n = 1 to 4) ionic liquids has been explored and the relationships with density and viscosity have been studied using COSMO related methodologies. Effects of the number of conformers, ionic character, anion-cation relative positions and the alkyl chain length of the cation on predictions of properties have been analyzed. The quality of the predictions has been tested by comparing with experimental results. Moreover, COSMO polarization charge densities, σ-profiles and σ-potentials of the conformers have been analyzed. Predictions on the chemical behavior based on the values of these properties in the conformers have been used to elucidate the affinity for electrophilic and nucleophilic reagents of ionic liquids. PMID:25149437

  18. Applicability of boron-doped diamond electrode to the degradation of chloride-mediated and chloride-free wastewaters

    International Nuclear Information System (INIS)

    The electrochemical degradation of chloride-mediated and chloride-free dye wastewaters was investigated on a boron-doped diamond (BDD) electrode in comparison with that on a dimensionally stable anode (DSA), and the applicability of BDD electrode to the degradation of these two kinds of wastewaters was explored. In chloride-free wastewater, the electrochemical degradation efficiency of dye on BDD electrode was much higher than that on DSA, with a chemical oxygen demand (COD) removal of 100% and 26% for BDD and DSA, respectively. In chloride-mediated dye wastewater, COD removal was faster than that in chloride-free wastewater on both BDD and DSA electrodes with COD removal efficiencies higher than 95%, whereas the rate of COD removal on DSA was faster than that on BDD electrode. The investigation indicates that DSA is more suitable than BDD electrode in degradation of originally chloride contained dye wastewaters for the sake of energy and time saving. However, for chloride-free dye wastewaters, with the aim of environmental protection, BDD electrode is more appropriate to realize complete mineralization. At the same time, the secondary pollution can be avoided

  19. Impact behaviour of an innovative plasticized poly(vinyl chloride) for the automotive industry

    Science.gov (United States)

    Bernard, C. A.; Bahlouli, N.; Wagner-Kocher, C.; Ahzi, S.; Rémond, Y.

    2015-09-01

    Plasticized poly(vinyl chloride) (PPVC) is widely used in the automotive industry in the design of structural parts for crashworthiness applications. Thus, it is necessary to study and understand the influence of the mechanical response and mechanical properties of PPVC over a wide range of strain rate, from quasi-static to dynamic loadings. The process is also investigated using different sample thicknesses. In this work, the strain rate effect of a new PPVC is investigated over a wide range of strain rates at three temperatures and for three thicknesses. A modelling of the yield stress is also proposed. The numerical prediction is in good agreement with the experimental results.

  20. Computational prediction of dust production in pebble bed reactors

    International Nuclear Information System (INIS)

    Highlights: ► Finite element analysis of frictional contact. ► Plasticity taken into account for nuclear graphite at room temperature. ► Prediction of order of magnitude for dust loading in PBRs. ► Archard wear model for wear mass calculations. - Abstract: This paper describes the computational modeling and simulation of graphite pebbles in frictional contacts as anticipated in a pebble bed reactor. For the high temperature gas-cooled reactor, the potential dust generation from frictional contact at the surface of pebbles and the subsequent lift-off and transport of dust and absorbed fission products are of safety concern at elevated temperatures under an air ingress accident. The aim of this work is to perform a computational study to estimate the quantity of the nuclear grade graphite dust produces from a typical anticipated configuration.

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

    OpenAIRE

    Fujio, Katsuhiko; Hayashi, Koji; Suzuki, Maki

    2014-01-01

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

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

    OpenAIRE

    Fujio, Katsuhiko; TAKEUCHI, Kumiko; Suzuki, Maki

    2012-01-01

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

  3. A synthetic chloride channel restores chloride conductance in human cystic fibrosis epithelial cells.

    Directory of Open Access Journals (Sweden)

    Bing Shen

    Full Text Available Mutations in the gene-encoding cystic fibrosis transmembrane conductance regulator (CFTR cause defective transepithelial transport of chloride (Cl(- ions and fluid, thereby becoming responsible for the onset of cystic fibrosis (CF. One strategy to reduce the pathophysiology associated with CF is to increase Cl(- transport through alternative pathways. In this paper, we demonstrate that a small synthetic molecule which forms Cl(- channels to mediate Cl(- transport across lipid bilayer membranes is capable of restoring Cl(- permeability in human CF epithelial cells; as a result, it has the potential to become a lead compound for the treatment of human diseases associated with Cl(- channel dysfunction.

  4. Nickel Chloride Promoted Glaser Coupling Reaction in Hot Water

    Institute of Scientific and Technical Information of China (English)

    Pin Hua LI; Lei WANG; Min WANG; Jin Can YAN

    2004-01-01

    A Glaser coupling reaction of terminal alkynes in the presence of nickel chloride without any organics and bases in hot water has been developed, which produces the corresponding homo-coupling products in good yields.

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

    Science.gov (United States)

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

    2011-10-28

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

  6. Catalytic Decomposition of Methylene Chloride by Sulfated Titania Catalysts

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Catalytic decomposition of methylene chloride in air below 300℃ was studied.Sulfated titania was very effective in converting 959ppm methylene chloride selectively to CO,CO2 and HCl.Complete decomposition of methylene chloride was achieved at low temperature(275℃).It was found that the acidic property of catalyst was a determinant factor for the catalytic activity.The presence of water vapor in the feed stream remarkably reduced the catalytic activity,which could be due to the blockage of acidic sites on the surface of catalyst by water molecules.A bifunctional catalyst comprising copper oxide was developed to improve the selectivity of catalytic oxidation,which indicated that copper oxide can promote the deep oxidation of methylene chloride.The crystal form of TiO2 imposes an important influence upon the catalytic oxidation.

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

    Energy Technology Data Exchange (ETDEWEB)

    Baylor, V.B.

    1985-10-01

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

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

    Directory of Open Access Journals (Sweden)

    A. Al-Saraj

    2010-01-01

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

  9. Solidification of spent TBP solvent with aluminium chloride compounds

    International Nuclear Information System (INIS)

    The new techniques for processing spent TBP was investigated. It was proved that treatment of TBP containing DBP with aluminium chloride resulted in the formation of aluminium phosphate suitable for long term storage and final disposal

  10. Methyltrioctylammonium chloride catalysed sonochemical synthesis of acridine diones

    Indian Academy of Sciences (India)

    Bhupinder Kaur; Harish Kumar

    2013-09-01

    The greener, clean and efficient protocol for the synthesis of acridine diones derivatives has been achieved by reacting aromatic aldehyde, dimedone and amines using methyltrioctylammonium chloride (Aliquate 336) as a catalyst under ultrasonic irradiations.

  11. Mechanisms of chloride decomposition in upgrading oil sands bitumen

    Energy Technology Data Exchange (ETDEWEB)

    Le, T.; Diaz, D.; Gray, M. [Alberta Univ., Edmonton, AB (Canada). Dept. of Chemical and Materials Engineering; Eaton, P. [Champion Technologies, Fresno, TX (United States); Wu, A. [Syncrude Canada Ltd., Edmonton, AB (Canada). Edmonton Research Centre

    2004-07-01

    In addition to clay minerals, bitumens from mining operations contain chloride salts because of the salinity of the extraction process water and the connate water in the ore. These chlorides form corrosive hydrochloric acid. High concentrations of organic acid components known as naphthenic acids are also found in bitumen from Alberta's oil sands. These also cause corrosion. Chloride salts, clays and organic acids may interact in the presence of steam to promote hydrochloric acid formation causing major corrosion problems in downstream facilities. This study examined the behaviour of these components under upgrading conditions. In particular, it examined the rate and the extent of the hydrolysis reactions for salts found in bitumen. Mixtures of bitumen, salts and organic acids were exposed to flowing steam at 100 to 400 degrees C under nitrogen purge. Ion chromatography was used to analyze the condensed vapours for chloride.

  12. Purification and reconstitution of chloride channels from kidney and trachea

    International Nuclear Information System (INIS)

    Chloride channels mediate absorption and secretion of fluid in epithelia, and the regulation of these channels is now known to be defective in cystic fibrosis. Indanyl-oxyacetic acid 94 (IAA-94) is a high-affinity ligand for the chloride channel, and an affinity resin based on that structure was developed. Solubilized proteins from kidney and trachea membranes were applied to the affinity matrix, and four proteins with apparent molecular masses of 97, 64, 40, and 27 kilodaltons were eluted from the column by excess IAA-94. A potential-dependent 36Cl- uptake was observed after reconstituting these proteins into liposomes. Three types of chloride channels with single-channel conductances of 26, 100, and 400 picosiemens were observed after fusion of these liposomes with planar lipid bilayers. Similar types of chloride channels have been observed in epithelia

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1990-07-01

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

  15. Electromagnetic-induction logging to monitor changing chloride concentrations

    Science.gov (United States)

    Metzger, Loren F.; Izbicki, John A.

    2013-01-01

    Water from the San Joaquin Delta, having chloride concentrations up to 3590 mg/L, has intruded fresh water aquifers underlying Stockton, California. Changes in chloride concentrations at depth within these aquifers were evaluated using sequential electromagnetic (EM) induction logs collected during 2004 through 2007 at seven multiple-well sites as deep as 268 m. Sequential EM logging is useful for identifying changes in groundwater quality through polyvinyl chloride-cased wells in intervals not screened by wells. These unscreened intervals represent more than 90% of the aquifer at the sites studied. Sequential EM logging suggested degrading groundwater quality in numerous thin intervals, typically between 1 and 7 m in thickness, especially in the northern part of the study area. Some of these intervals were unscreened by wells, and would not have been identified by traditional groundwater sample collection. Sequential logging also identified intervals with improving water quality—possibly due to groundwater management practices that have limited pumping and promoted artificial recharge. EM resistivity was correlated with chloride concentrations in sampled wells and in water from core material. Natural gamma log data were used to account for the effect of aquifer lithology on EM resistivity. Results of this study show that a sequential EM logging is useful for identifying and monitoring the movement of high-chloride water, having lower salinities and chloride concentrations than sea water, in aquifer intervals not screened by wells, and that increases in chloride in water from wells in the area are consistent with high-chloride water originating from the San Joaquin Delta rather than from the underlying saline aquifer.

  16. Local impermeant anions establish the neuronal chloride concentration

    DEFF Research Database (Denmark)

    Glykys, J; Dzhala, V; Egawa, K;

    2014-01-01

    Neuronal intracellular chloride concentration [Cl(-)](i) is an important determinant of γ-aminobutyric acid type A (GABA(A)) receptor (GABA(A)R)-mediated inhibition and cytoplasmic volume regulation. Equilibrative cation-chloride cotransporters (CCCs) move Cl(-) across the membrane, but accumulat...... anions determine the homeostatic set point for [Cl(-)], and hence, neuronal volume and the polarity of local GABA(A)R signaling....

  17. Influence of cracks on chloride penetration and corrosion initiation time

    OpenAIRE

    Audenaert, K.; De Schutter, G.; L. Marsavina

    2009-01-01

    Chloride initiated reinforcement corrosion is the main durability problem for concrete structures in a marine environment. If the chlorides reach the reinforcement steel, it will depassivate and start to corrode in presence of air and water. Since the corrosion products have a larger volume than the intial products, concrete stresses are induced, leading to spalling and degradation of the concrete structures. If cracks, caused by early drying, thermal effects, shrinkage or overstress, are pre...

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

    OpenAIRE

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

    2013-01-01

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

  19. Recovering germanium from coal ash by chlorination with ammonium chloride

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A new process of enriching germanium from coal ash was developed. The process involves in mixing the coal ash and ammonium chloride and then roasting the mixture to produce germanium chloride that is then absorbed by dilute hydrochloric acid and hydrolyzed to germanium oxide. The germanium recovery reached to 80.2% at the optimum condition: mass ratio of NH4Cl/coal ash is 0.15, roasting temperature 400℃ and roasting time 90 min.

  20. Polarization and Charge Transfer in the Hydration of Chloride Ions

    OpenAIRE

    Zhao, Zhen; Rogers, David M.; Beck, Thomas L.

    2009-01-01

    A theoretical study of the structural and electronic properties of the chloride ion and water molecules in the first hydration shell is presented. The calculations are performed on an ensemble of configurations obtained from molecular dynamics simulations of a single chloride ion in bulk water. The simulations utilize the polarizable AMOEBA force field for trajectory generation, and MP2-level calculations are performed to examine the electronic structure properties of the ions and surrounding...

  1. Effect of kaolin treatment temperature on mortar chloride permeability

    OpenAIRE

    Puertas, F.; Mejía de Gutiérrez, R.; J. Torres

    2007-01-01

    The present paper discusses the results of chloride resistance tests conducted on ordinary Portland cement (OPC) mortars containing a Colombian kaolin pre-treated at temperatures of from 600 to 800 ºC. The resulting metakaolin (MK) was added to OPC mortar mixes in proportions of 10 and 20% by cement weight. The mortars were compared for physical and chemical properties, including capillary absorption, chloride permeability and pore microstructure as assessed by mercury porosimetry....

  2. Extraction and immobilization of simulated pyrometallurgical chloride waste in Zeolite

    International Nuclear Information System (INIS)

    Zeolites are effective media for the removal and immobilization of fission products waste from pyrometallurgical reprocessing of nuclear fuels. In the present study, equilibration experiments between zeolite 4A and a simulated: pyrometallurgical chloride waste were carried out. Several batches of equilibration were carried out by varying the zeolite to salt (Z/S) ratio. The effects of Z/S on the extraction behaviour of the waste chloride salts were explored. (author)

  3. Intracellular chloride concentration of the mouse vomeronasal neuron

    OpenAIRE

    Kim, Sangseong; Ma, Limei; Unruh, Jay; McKinney, Sean; Yu, C. Ron

    2015-01-01

    Background The vomeronasal organ (VNO) is specialized in detecting pheromone and heterospecific cues in the environment. Recent studies demonstrate the involvement of multiple ion channels in VNO signal transduction, including the calcium-activated chloride channels (CACCs). Opening of CACCs appears to result in activation of VNO neuron through outflow of Cl− ions. However, the intracellular Cl− concentration remains undetermined. Results We used the chloride ion quenching dye, MQAE, to measu...

  4. Large Scale Synthesis of Carbon Nanofibres on Sodium Chloride Support

    OpenAIRE

    Ravindra Rajarao; Badekai Ramachandra Bhat

    2012-01-01

    Large scale synthesis of carbon nanofibres (CNFs) on a sodium chloride support has been achieved. CNFs have been synthesized using metal oxalate (Ni, Co and Fe) as catalyst precursors at 680 C by chemical vapour deposition method. Upon pyrolysis, this catalyst precursors yield catalyst nanoparticles directly. The sodium chloride was used as a catalyst support, it was chosen because of its non‐toxic and water soluble nature. Problems, such as the detrimental effect of CNFs, the detrimental ef...

  5. Durability Analysis of Subway Station in Chloride Environment

    OpenAIRE

    Yang LuFeng; Yu Bo; Hong Bin

    2013-01-01

    In this study, a finite element model for chloride ions transport in saturated concrete was proposed based on the Fick’s second law of diffusion. The governing partial differential equation was solved numerically in space as a boundary-value problem and in time as an initial-value problem by means of the finite element formulations. The maximum allowable value of chloride diffusion coefficient within different locations of subway station with service life of 100a was achieved and suggestions ...

  6. Influence of cracks on chloride penetration in concrete

    OpenAIRE

    Audenaert, K.; Schutter, G. de; MARSAVINA, L

    2009-01-01

    Chloride initiated reinforcement corrosion is the main durability problem for concrete structures in a marine environment. If the chlorides reach the reinforcement steel, it will depassivate and start to corrode in presence of air and water. Since the corrosion products have a larger volume than the initial products, concrete stresses are induced, leading to spalling and degradation of the concrete structures. If cracks, caused by early drying, thermal effects, shrinkage movements or overstre...

  7. 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.

  8. Density Functional Theory Study on Conformers of Benzoylcholine Chloride

    OpenAIRE

    Mustafa Karakaya; Fatih Ucun; Ahmet Tokatlı

    2013-01-01

    The optimized molecular structures and vibrational frequencies and also gauge including atomic orbital (GIAO) 1H and 13C NMR shift values of benzoylcholine chloride [(2-benzoyloxyethyl) trimethyl ammonium chloride] have been calculated using density functional theory (B3LYP) method with 6-31++G(d) basis set. The comparison of the experimental and calculated infrared (IR), Raman, and nuclear magnetic resonance (NMR) spectra has indicated that the experimental spectra are formed from the superp...

  9. Stabilizing Plutonium oxide material containing Chloride salts at PFP

    International Nuclear Information System (INIS)

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

  10. Congenital chloride diarrhea: a review of twelve Arabian children

    Directory of Open Access Journals (Sweden)

    Elrefae F

    2013-06-01

    Full Text Available Fawaz Elrefae,1 Ahmed Farag Elhassanien,2 Hesham Abdel-Aziz Alghiaty3 1Pediatric Gastroenterology, Al-Adan Hospital, Kuwait; 2Faculty of Medicine, Elmansoura University, El Mansoura, El Dakahleya, Egypt; 3Faculty of Medicine, Benha University, Egypt Background: Congenital chloride diarrhea (CCD, a rare autosomal recessive disorder, is characterized by sustained watery diarrhea (due to defect of active Chloride/HCO3 exchange in the ileum and colon with high fecal chloride. Objective: To spotlight the common presentation of CCD for early management and prevention of complications. Subjects and methods: This is a retrospective case series study of patients diagnosed as CCD who were followed up in the pediatric department of Al-Adan Hospital, Kuwait. Results: Twelve patients diagnosed with CCD were born to consanguineous parents; had antenatal history of intrauterine growth retardation (IUGR; polyhydramnios; and distended hypoechoic fetal bowel; and presented with abdominal distension, hypotonia and muscle wasting. 90% of patients had maternal hypertension and 75% of patients had absence of normal meconium at birth. Our patients showed a decrease in serum sodium, potassium, chloride and urine chloride. Conclusion: A high level of suspicion for an early diagnosis of CCD should be considered for any infant presenting with chronic diarrhea, especially in the presence of consanguineous marriage, and the characteristic features in antenatal ultrasound. Thus, allowing for early investigations and appropriate management. Keywords: congenital chloride diarrhea, children, chronic diarrhea, metabolic alkalosis, prenatal diagnosis

  11. Selective process of zinc extraction from spent Zn–MnO2 batteries by ammonium chloride leaching

    OpenAIRE

    Nogueira, C. A.; Margarido, F.

    2015-01-01

    Recycling of spent Zn-MnO2 batteries by hydrometallurgy is usually carried out by leaching in acid media, mainly with sulphuric acid solutions. Another type of leachant was used in this work, specifically solutions of concentrated ammonium chloride. The development of this study has relied on the prediction of the chemical behavior of the constituting phases based on data obtained from theoretical and experimental equilibrium values. The assessment of the effects of factors on leaching effici...

  12. FIRST DETECTION OF HYDROGEN CHLORIDE TOWARD PROTOSTELLAR SHOCKS

    International Nuclear Information System (INIS)

    We present the first detection of hydrogen chloride in a protostellar shock by observing the fundamental transition at 626 GHz with the HIFI spectrometer. We detected two of the three hyperfine lines from which we derived a line opacity ≤1. Using a non-local thermodynamic equilibrium large velocity gradient code, we constrained the HCl column density, temperature, and density of the emitting gas. The hypothesis that the emission originates in the molecular cloud is ruled out because it would imply a very dense gas. Conversely, assuming that the emission originates in the 10''-15'' size shocked gas previously observed at the IRAM Plateau de Bure Interferometer, we obtain N(HCl) = 0.7-2 × 1013 cm–2, temperature >15 K, and density >3 × 105 cm–3. Combining these with the Herschel HIFI CO(5-4) observations allows us to further constrain the gas density and temperature, 105-106 cm–3 and 120-250 K, respectively, as well as the HCl column density, 2 × 1013 cm–2, and, finally, the abundance ∼3-6 × 10–9. The estimated HCl abundance is consistent with that previously observed in low- and high-mass protostars. This puzzling result in the L1157-B1 shock, where species from volatile and refractory grain components are enhanced, suggests either that HCl is not the main reservoir of chlorine in the gas phase, which goes against previous chemical model predictions, or that the elemental chlorine abundance is low in L1157-B1. Astrochemical modeling suggests that HCl is in fact formed in the gas phase at low temperatures prior to the occurrence of the shock; the latter does not enhance its abundance.

  13. FIRST DETECTION OF HYDROGEN CHLORIDE TOWARD PROTOSTELLAR SHOCKS

    Energy Technology Data Exchange (ETDEWEB)

    Codella, C.; Vasta, M. [INAF, Osservatorio Astrofisico di Arcetri, Largo Enrico Fermi 5, I-50125 Firenze (Italy); Ceccarelli, C.; Lefloch, B.; Faure, A.; Wiesenfeld, L. [UJF-Grenoble 1/CNRS-INSU, Institut de Planetologie et d' Astrophysique de Grenoble (IPAG) UMR 5274, Grenoble, F-38041 (France); Bottinelli, S.; Caux, E. [Universite de Toulouse (France); UPS-OMP, CNRS, IRAP, Toulouse, BP 44346, F-31028 (France); Salez, M.; Cabrit, S. [Observatoire de Paris-Meudon, LERMA UMR CNRS 8112, Meudon (France); Viti, S., E-mail: codella@rcetri.astro.it [Department of Physics and Astronomy, University College London, London (United Kingdom)

    2012-01-10

    We present the first detection of hydrogen chloride in a protostellar shock by observing the fundamental transition at 626 GHz with the HIFI spectrometer. We detected two of the three hyperfine lines from which we derived a line opacity {<=}1. Using a non-local thermodynamic equilibrium large velocity gradient code, we constrained the HCl column density, temperature, and density of the emitting gas. The hypothesis that the emission originates in the molecular cloud is ruled out because it would imply a very dense gas. Conversely, assuming that the emission originates in the 10''-15'' size shocked gas previously observed at the IRAM Plateau de Bure Interferometer, we obtain N(HCl) = 0.7-2 Multiplication-Sign 10{sup 13} cm{sup -2}, temperature >15 K, and density >3 Multiplication-Sign 10{sup 5} cm{sup -3}. Combining these with the Herschel HIFI CO(5-4) observations allows us to further constrain the gas density and temperature, 10{sup 5}-10{sup 6} cm{sup -3} and 120-250 K, respectively, as well as the HCl column density, 2 Multiplication-Sign 10{sup 13} cm{sup -2}, and, finally, the abundance {approx}3-6 Multiplication-Sign 10{sup -9}. The estimated HCl abundance is consistent with that previously observed in low- and high-mass protostars. This puzzling result in the L1157-B1 shock, where species from volatile and refractory grain components are enhanced, suggests either that HCl is not the main reservoir of chlorine in the gas phase, which goes against previous chemical model predictions, or that the elemental chlorine abundance is low in L1157-B1. Astrochemical modeling suggests that HCl is in fact formed in the gas phase at low temperatures prior to the occurrence of the shock; the latter does not enhance its abundance.

  14. Optimal control of batch emulsion polymerization of vinyl chloride

    Energy Technology Data Exchange (ETDEWEB)

    Damslora, Andre Johan

    1998-12-31

    The highly exothermic polymerization of vinyl chloride (VC) is carried out in large vessels where the heat removal represents a major limitation of the production rate. Many emulsion polymerization reactors are operated in such a way that a substantial part of the heat transfer capacity is left unused for a significant part of the total batch time. To increase the reaction rate so that it matches the heat removal capacity during the course of the reaction, this thesis proposes the use of a sufficiently flexible initiator system to obtain a reaction rate which is high throughout the reaction and real-time optimization to compute the addition policy for the initiator. This optimization based approach provides a basis for an interplay between design and control and between production and research. A simple model is developed for predicting the polymerization rate. The model is highly nonlinear and open-loop unstable and may serve as an interesting case for comparison of nonlinear control strategies. The model is fitted to data obtained in a laboratory scale reactor. Finally, the thesis discusses optimal control of the emulsion polymerization reactor. Reduction of the batch cycle time is of major economic importance, as long as the quality parameters are within their specifications. The control parameterization had a major influence on the performance. A differentiable spline parameterization was applied and the optimization is illustrated in a number of cases. The best performance is obtained when the reactor temperature is obtained when the optimization is combined with some form of closed-loop control of the reactor temperature. 112 refs., 48 figs., 4 tabs.

  15. Investigation of chloride-release of nuclear grade resin in PWR primary system coolant

    International Nuclear Information System (INIS)

    A new preparation technique is developed for making the low-chloride nuclear-grade resin by commercial resin. The chloride remained in nuclear grade resin may release to PWR primary coolant. The amount of released chloride is depended on the concentration of boron, lithium, other anion impurities, and remained chloride concentration in resin

  16. Ab initio Investigations of the Equilibria between Trichlorothioacetyl Chloride, Tetrachlorothiirane, and Trichloroethenesulfenyl Chloride, their Reactants and Decomposition Products

    DEFF Research Database (Denmark)

    Pedersen, Kim Vestergaard; Christensen, Henrik; Shim, Irene;

    2004-01-01

    Trichlorothioacetyl chloride 1, tetrachlorothiirane 2, and trichloroethenesulfenyl chloride 3 and the equilibria between them have been investigated by ab initio Hartree-Fock (HF), Møller-Plesset second order perturbation (MP2) calculations, and by Gaussian-3 theory, G3(MP2). The transition state...... of the isomerization reactions have been identified. Also investigated were possible reactions leading to the isomers and their possible decomposition products. The results show that the unobserved isomerization reactions are feasible....

  17. A small synthetic molecule functions as a chloride-bicarbonate dual-transporter and induces chloride secretion in cells.

    Science.gov (United States)

    Liu, Peng-Yun; Li, Shing-To; Shen, Fang-Fang; Ko, Wing-Hung; Yao, Xiao-Qiang; Yang, Dan

    2016-05-31

    A C2 symmetric small molecule composed of l-phenylalanine and isophthalamide was found to function as a Cl(-)/HCO3(-) dual transporter and self-assemble into chloride channels. In Ussing-chamber based short-circuit current measurements, this molecule elicited chloride-dependent short-circuit current (Isc) increase in both Calu-3 cell and CFBE41o-cell (with F508del mutant CFTR) monolayers. PMID:27188496

  18. Technical note: Could benzalkonium chloride be a suitable alternative to mercuric chloride for preservation of seawater samples?

    OpenAIRE

    Gloël, J.; Robinson, C.; Tilstone, G. H.; Tarran, G.; J. Kaiser

    2015-01-01

    Instrumental equipment unsuitable or unavailable for fieldwork as well as lack of ship space can necessitate the preservation of seawater samples prior to analysis in a shore-based laboratory. Mercuric chloride (HgCl2) is routinely used for such preservation, but its handling and subsequent disposal incur environmental risks and significant expense. There is therefore a strong motivation to find less hazardous alternatives. Benzalkonium chloride (BAC) has been used previousl...

  19. Technical Note: Could benzalkonium chloride be a suitable alternative to mercuric chloride for preservation of seawater samples?

    OpenAIRE

    Gloël, J.; Robinson, C.; Tilstone, G. H.; Tarran, G.; J. Kaiser

    2015-01-01

    Instrumental equipment unsuitable or unavailable for fieldwork as well as lack of ship space can necessitate the preservation of seawater samples prior to analysis in a shore-based laboratory. Mercuric chloride (HgCl2) is routinely used for such preservation, but its handling and subsequent disposal incur significant risks and expense. Benzalkonium chloride (BAC) has been used previously for freshwater samples. Here, we assess BAC as a less hazardous alterna...

  20. Reliability-based service life prediction of existing concrete structures under marine environment

    Institute of Scientific and Technical Information of China (English)

    吴灵杰; 周拥军; 寇新建; 蒋萌

    2015-01-01

    Chloride-induced corrosion of the reinforcement is considered as one of the major mechanisms resulting in the reduction of structural resistance of reinforced concrete structural elements located in marine and other aggressive environments. A study of reinforced concrete structures located at the Fangcheng dock in the Beibu Gulf port, China, was present. The result from field survey indicates that the concrete cover depth and chloride diffusion coefficient fit best normal distribution and lognormal distribution, respectively. The service life of structure is about 55 a, while initiation time is 45 a. Sensitivity analysis indicates that the most influential factor of the structure service life prediction is concrete cover, followed by diffusion coefficient, diffusion decay index, critical chloride concentration, surface chloride concentration, current density and localized pitting corrosion. Finally, the effects of diffusion decay index and critical chloride concentration on structure service life prediction are discussed.

  1. Characterization of the lanthanum chloride scintillation detector

    International Nuclear Information System (INIS)

    This paper reports about the investigations on the performance of the new earth-rare halide Scintillator, the LaCl3:10%Ce, which has been discovered with attractive scintillation properties: fast, efficient, and high-energy resolution. The combination of good brightness and linear response has naturally resulted in a very good energy resolution, whereas the fast decay time promoted counting applications at very high rate and very fast timing resolution. Energy resolutions of (2.99±0.02) %, (8.66±0.02) %, and (2.05±0.01) % have been achieved by exciting the detector with 662 keV 137Cs, 122 keV 152Eu, and 1332.5 keV 60Co sources respectively, at room temperature. The variations of the resolution as a function of both shaping time and high voltage have been studied and found to be relatively linear. The timing resolution was also studied. The value of 1.07 ns FWHM has been recorded with LaCl3:10%Ce and BaF2 detectors operating in coincidence mode, using 1333.5 keV γ-ray 60Co peak. Compared to similar studies, this timing resolution was worse than expected even if the exciting radioactive sources used in the two experiments were different. The efficiency values of (0.24±0.01)%, (0.01±0.01)% and (0.09±0.01)% were obtained with laboratory 137Cs, 152Eu, 60Co isotopes respectively. These detector efficiency values were very low, due to the smaller detector sizes used in these earlier crystals and to the large detector-source-distance used in this experiment. The Lanthanum Chloride Scintillator detector is hygroscopic and relatively expensive compared to established scintillators. In addition, it carries internal contamination in 138La and 227Ac for larger thicknesses. Nevertheless, the energy resolution figures achieved, twice as good as that of NaI(Tl), are in good agreement with those reported elsewhere. They credit the scintillation detectors as good challengers of semiconductor-based detectors, allowing their application fields to be extended. (author)

  2. Effects of Cations on Corrosion of Inconel 625 in Molten Chloride Salts

    Science.gov (United States)

    Zhu, Ming; Ma, Hongfang; Wang, Mingjing; Wang, Zhihua; Sharif, Adel

    2016-04-01

    Hot corrosion of Inconel 625 in sodium chloride, potassium chloride, magnesium chloride, calcium chloride and their mixtures with different compositions is conducted at 900°C to investigate the effects of cations in chloride salts on corrosion behavior of the alloy. XRD, SEM/EDS were used to analyze the compositions, phases, and morphologies of the corrosion products. The results showed that Inconel 625 suffers more severe corrosion in alkaline earth metal chloride molten salts than alkaline metal chloride molten salts. For corrosion in mixture salts, the corrosion rate increased with increasing alkaline earth metal chloride salt content in the mixture. Cations in the chloride molten salts mainly affect the thermal and chemical properties of the salts such as vapor pressure and hydroscopicities, which can affect the basicity of the molten salt. Corrosion of Inconel 625 in alkaline earth metal chloride salts is accelerated with increasing basicity.

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

    International Nuclear Information System (INIS)

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

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

    OpenAIRE

    Joon Woo Park; Ki Yong Ann; Chang-Geun Cho

    2015-01-01

    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 ...

  5. Effect of n-tetradecanol on the extraction of iron(III), cobalt(II), and zinc(II) chlorides with tri-n-dodecylammonium chloride

    International Nuclear Information System (INIS)

    Equations are proposed to describe the reduction in the partition coefficients of metal chlorides in amine extractant systems following the addition of alcohols. The equations include two empirical factors: solvation parameters for amine chloride and the compound undergoing extraction. These parameters can be found from independent data. The equations have been used to describe the extraction of micro amounts of iron(III), cobalt(II), and zinc(II) chlorides by tridodecylammonium chloride in the presence of n-tetradecanol

  6. Inhibiting properties of benzimidazole films for Cu(II)/Cu(I) reduction in chloride media studied by RDE and EQCN techniques

    International Nuclear Information System (INIS)

    The effects of benzimidazole (BIM) and 2-methylbenzimidazole (MBIM) on the electroreduction of Cu(II) on a rotating Pt disk electrode in chloride media were investigated. These studies were undertaken in conjunction with earlier observation that these imidazole derivatives act as inhibitors of copper corrosion processes and are non-toxic. We have found that BIM and MBIM also form adsorption films on Pt, which are able to inhibit one-electron reduction of Cu(II) to Cu(I) and prevent the development of convective diffusion limiting current wave. The inhibition was found to be controlled by field-assisted mass transfer in the film. The ingress of Cu(II) species into the film was detected using the EQCN technique. The EQCN measurements indicate that small fraction of Cu(I) formed in the film by reduction of Cu(II) is retained in the film, most likely in the form of CuCl. The uptake of CuCl by inhibitor films diminishes in strongly inhibiting films (e.g., in acidic medium). The inhibition effectiveness of Cu(II) reduction process by Pt vertical bar BIM and Pt vertical bar MBIM films increases strongly with increasing acidity of the medium in the pH range from 3.0 to 1.0. The mechanism of this remarkable pH effect has been proposed. It is based on charge and pH-induced film restructuring, including changes in orientation and protonation of BIM molecules in the film

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

    International Nuclear Information System (INIS)

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

  8. VOCl as a Cathode for Rechargeable Chloride Ion Batteries.

    Science.gov (United States)

    Gao, Ping; Reddy, M Anji; Mu, Xiaoke; Diemant, Thomas; Zhang, Le; Zhao-Karger, Zhirong; Chakravadhanula, Venkata Sai Kiran; Clemens, Oliver; Behm, R Jürgen; Fichtner, Maximilian

    2016-03-18

    A novel room temperature rechargeable battery with VOCl cathode, lithium anode, and chloride ion transporting liquid electrolyte is described. The cell is based on the reversible transfer of chloride ions between the two electrodes. The VOCl cathode delivered an initial discharge capacity of 189 mAh g(-1) . A reversible capacity of 113 mAh g(-1) was retained even after 100 cycles when cycled at a high current density of 522 mA g(-1) . Such high cycling stability was achieved in chloride ion batteries for the first time, demonstrating the practicality of the system beyond a proof of concept model. The electrochemical reaction mechanism of the VOCl electrode in the chloride ion cell was investigated in detail by ex situ X-ray diffraction (XRD), infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The results confirm reversible deintercalation-intercalation of chloride ions in the VOCl electrode. PMID:26924132

  9. Bone marrow scintigraphy with 111In-chloride

    International Nuclear Information System (INIS)

    It is assumed that 111In-chloride is bound to serum transferrin and then transported into reticulocyte in erythropoietic marrow. However, several biochemical differences between radioiron and 111In have been reported since these years. In present study, clinical usefulness of 111In-chloride bone marrow scintigraphy was examined especially by comparing 111In-chloride image with sup(99m)Tc-colloid. Obtained results are as follows: 1) In most cases, both 111In-chloride and sup(99m)Tc-colloid images showed similar bone marrow distributions. 2) In three out of 7 cases with hypoplastic anemia and two patients with bone marrow irradiation (700-1,000 rad), the central marrow or irradiated marrow showed marked decreased uptake of 111In, and showed normal uptake of sup(99m)Tc. 3) In two out of 3 cases with chronic myelogenous leucemia, central marrow showed normal uptake of 111In, and showed decreased uptake of sup(99m)Tc. From the present study, the same dissociation findings as those between radioiron and radiocolloid could be obtained in hypoplastic anemia and bone marrow irradiation. 111In-chloride would appear to be a useful erythropoietic imaging agent, although further study of exact comparison with radioiron should be necessary. (auth.)

  10. Cystic fibrosis with normal sweat chloride concentration: case report

    Directory of Open Access Journals (Sweden)

    Silva Filho Luiz Vicente Ferreira da

    2003-01-01

    Full Text Available Cystic fibrosis is a genetic disease usually diagnosed by abnormal sweat testing. We report a case of an 18-year-old female with bronchiectasis, chronic P. aeruginosa infection, and normal sweat chloride concentrations who experienced rapid decrease of lung function and clinical deterioration despite treatment. Given the high suspicion ofcystic fibrosis, broad genotyping testing was performed, showing a compound heterozygous with deltaF508 and 3849+10kb C->T mutations, therefore confirming cystic fibrosis diagnosis. Although the sweat chloride test remains the gold standard for the diagnosis of cystic fibrosis, alternative diagnostic tests such as genotyping and electrophysiologic measurements must be performed if there is suspicion of cystic fibrosis, despite normal or borderline sweat chloride levels.

  11. Aluminum chloride restoration of in-situ leached uranium ores

    Energy Technology Data Exchange (ETDEWEB)

    Grant, D.C.; Burgman, H.A.

    1984-01-01

    During in-situ uranium mining using ammonium bicarbonate lixiviant, the ammonium exchanges with cations on the ore's clay. After mining is complete, the ammonium may desorb into post-leach ground water. For the particular ore studied, other elements (uranium and selenium) that are mobilized during the leaching process, have also been found in post-leach ground water. Laboratory column tests, used to simulate the leaching process, have shown that aluminum chloride can rapidly remove ammonium from the ore and, thus, greatly reduce the subsequent ammonium leakage level into ground water. The aluminum chloride has also been found to reduce the leakage levels of uranium and selenium. In addition, the aluminum chloride treatment produces a rapid increase in permeability.

  12. Aluminum chloride restoration of in situ leached uranium ores

    International Nuclear Information System (INIS)

    During in situ uranium mining using ammonium bicarbonate lixiviant, the ammonium exchanges with cations on the ore's clay. After mining is complete, the ammonium may desorb into post-leach ground water. For the particular ore studied, other chemicals (i.e., uranium and selenium) which are mobilized during the leach process, have also been found in the post-leach ground water. Laboratory column tests, used to simulate the leaching process, have shown that aluminum chloride can rapidly remove ammonium from the ore and thus greatly reduce the subsequent ammonium leakage level into ground water. The aluminum chloride has also been found to reduce the leakage levels of uranium and selenium. In addition, the aluminum chloride treatment produces a rapid improvement in permeability

  13. Aluminum chloride restoration of in situ leached uranium ores

    Energy Technology Data Exchange (ETDEWEB)

    Grant, D.C.; Burgman, M.A.

    1982-09-01

    During in situ uranium mining using ammonium bicarbonate lixiviant, the ammonium exchanges with cations on the ore's clay. After mining is complete, the ammonium may desorb into post-leach ground water. For the particular ore studied, other chemicals (i.e., uranium and selenium) which are mobilized during the leach process, have also been found in the post-leach ground water. Laboratory column tests, used to simulate the leaching process, have shown that aluminum chloride can rapidly remove ammonium from the ore and thus greatly reduce the subsequent ammonium leakage level into ground water. The aluminum chloride has also been found to reduce the leakage levels of uranium and selenium. In addition, the aluminum chloride treatment produces a rapid improvement in permeability.

  14. A 3-D hydrologic transport model of a water recharge system using carbamazepine and chloride as tracers

    Science.gov (United States)

    Rona, Michael; Gasser, Guy; Negev, Ido; Pankratov, Irena; Elhanany, Sara; Lev, Ovadia; Gvirtzman, Haim

    2014-05-01

    Wastewater recharge facilities are often used as a final water treatment before the discharge to the sea or before water reclamation. These facilities are often located in active aquifers that supply drinking water. Thus, leakage from the water recharge facility and gradual expansion of the underground wastewater plume are of considerable health concern. Hydrological modeling of water recharge systems are widely used as operational and predictive tools. These models rely on distributed water head monitoring and at least one chemical or physical tracer to model solutes' transport. Refractory micropollutants have proven useful in qualitative identification of pollution leakages and for quantification of pollution to a specific site near water recharge facilities. However, their usefulness as tracers for hydrological modeling is still questionable. In this article, we describe a long term, 3-D hydraulic model of a large-scale wastewater effluents recharge system in which a combination of chloride and a refractory micropollutant, carbamazepine is used to trace the solute transport. The combination of the two tracers provides the model with the benefits of the high specificity of the carbamazepine and the extensive historic data base that is available for chloride. The model predicts westward expansion of the pollution plume, whereas a standing front is formed at the east. These trends can be confirmed by the time trace of the carbamazepine concentrations at specific locations. We show that the combination of two tracers accounts better (at least at some locations) for the evolution of the pollution plume than a model based on chloride or carbamazepine alone.

  15. Chloride channels of platelets%血小板氯通道

    Institute of Scientific and Technical Information of China (English)

    陈晓琳; 尹松梅

    2004-01-01

    Chloride channels distribute widely in the body, and participate in many physiological actions and regulatory processes. Based on their physiological roles and molecular structures, six kinds of chloride channels have been identified: (1) The chloride channels family; (2) Cystic fibrosis transmembrane conductance regulator; (3) Swelling-activated chloride channels; (4) Calcium-activated chloride channels; (5) The p64 (CLIC) gene family; (6) γ-aminobutyric acid and glycine receptors. The chloride channels do exist in platelets, and their appearances are dependent on the presence of intracellular calcium. Blocking agents of chloride channels inhibit the thrombin-activated platelet aggregation and the elevation of the intracellular calcium concentration in a dose-dependent manner. It is suggested that chloride channels play a role in the activation of platelets. In addition, chloride channels act on both the cell volume regulation and the intracellular pH regulation in platelets.

  16. Climate prediction and predictability

    Science.gov (United States)

    Allen, Myles

    2010-05-01

    Climate prediction is generally accepted to be one of the grand challenges of the Geophysical Sciences. What is less widely acknowledged is that fundamental issues have yet to be resolved concerning the nature of the challenge, even after decades of research in this area. How do we verify or falsify a probabilistic forecast of a singular event such as anthropogenic warming over the 21st century? How do we determine the information content of a climate forecast? What does it mean for a modelling system to be "good enough" to forecast a particular variable? How will we know when models and forecasting systems are "good enough" to provide detailed forecasts of weather at specific locations or, for example, the risks associated with global geo-engineering schemes. This talk will provide an overview of these questions in the light of recent developments in multi-decade climate forecasting, drawing on concepts from information theory, machine learning and statistics. I will draw extensively but not exclusively from the experience of the climateprediction.net project, running multiple versions of climate models on personal computers.

  17. SiC epitaxy growth using chloride-based CVD

    International Nuclear Information System (INIS)

    The growth of thick epitaxial SiC layers needed for high-voltage, high-power devices is investigated with the chloride-based chemical vapor deposition. High growth rates exceeding 100 μm/h can be obtained, however to obtain device quality epilayers adjustments of the process parameters should be carried out appropriately for the chemistry used. Two different chemistry approaches are compared: addition of hydrogen chloride to the standard precursors or using methyltrichlorosilane, a molecule that contains silicon, carbon and chlorine. Optical and electrical techniques are used to characterize the layers.

  18. Microreactor Technology for On-Site Production of Methyl Chloride

    OpenAIRE

    Schmidt, S A.; Vajglová, Z. (Zuzana); Eränen, K.; Murzin, D.Y.; Salmi, T

    2014-01-01

    A reactor setup consisting of two stainless steel microreactors [gas-phase microreactor (GPMR)-mix from the Institut für Mikrotechnik Mainz (IMM)] coupled in series was used for production of methyl chloride by hydrochlorination of methanol. The catalyst was γ-alumina on microreactor platelets. The influence of temperature on the methanol conversion and methyl chloride selectivity was investigated. A maximum conversion of 97.6% and a selectivity of 98.8% were reached at 340°C, which is c...

  19. Venous uptake of 201Tl as thallous chloride

    International Nuclear Information System (INIS)

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

  20. Steel corrosion in anoxic mediums with high chloride concentrations

    International Nuclear Information System (INIS)

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

  1. Production and mitigation of acid chlorides in geothermal steam

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-06-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2008-01-01

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

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

    International Nuclear Information System (INIS)

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

  4. The compatibility of steel and aluminium with calcium chloride/ammonia, magnesium chloride/methylamine and magnesium chloride/methylamine/decane

    International Nuclear Information System (INIS)

    The use of pairs of substances such as calcium chloride/ammonia or magnesium chloride/methylamine for distant heating or heat storage requires compatibility between these substances and the structural materials of the reactor vessels, transport-containers, and/or heat exchangers. Readily weldable mild steel or aluminium are considered likely candidates for the structural materials for transport containers or heat exchangers. In these compatibility investigations the metal samples have been held in contact with the chemical substances under different conditions (temperature, pressure, time) and after the compatibility treatments, the samples were tested. When there is no detectable change in the properties of the samples after the compatibility treatments (in comparison with the as received status) the compatibility is deemed good. Weight changes, surface investigations, fatigue strength tests and metallographical investigations were performed for determining this compatibility. (Auth.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-01-01

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

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

    International Nuclear Information System (INIS)

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

  7. The precipitation of radioactive radium-226 from acidic chloride leach liquors with barium chloride

    International Nuclear Information System (INIS)

    The conventional barium chloride (BaClsub(2)) precipitation has been effective in the 99+ percent removal of radium-226 as radium-barium sulphate [RaBa(SOsub(4))sub(2)] sludge, from HCl liquors produced by laboratory and pilot leaches of Canadian uranium ores. Radium-226, due to its low-level radiation characteristics, is removed as it has been identified as an environmental and long-term health problem. The formation of the RaBa(SOsub(4))sub(2) sludge was aided due to adequate sulphate (SOsub(4)) concentrations in the HCl pilot liquors produced. Recyclable Rasup(226) concentrations of about 66 pCi/L, in treated effluents, will cost about 1/10 that of effluents below federal environmental guidelines of 10 pCi Rasup(226)/L. Toxic barium (Ba) will potentially build up in effluents as recyclable Rasup(226) concentrations around 66 pCi/L. Barium, in addition to being added to liquors as BaClsub(2) precipitant, is present in the radioactive ore and HCl leach liquors

  8. Ion exchange in a zeolite-molten chloride system

    International Nuclear Information System (INIS)

    Electrometallurgical treatment of spent nuclear fuel results in a secondary waste stream of radioactive fission products dissolved in chloride salt. Disposal plans include a waste form that can incorporate chloride forms featuring one or more zeolites consolidated with sintered glass. A candidate method for incorporating fission products in the zeolites is passing the contaminated salt over a zeolite column for ion exchange. To date, the molten chloride ion-exchange properties of four zeolites have been investigated for this process: zeolite A, IE95 reg-sign, clinoptilolite, and mordenite. Of these, zeolite A has been the most promising. Treating zeolite 4A, the sodium form of zeolite A , with the solvent salt for the waste stream-lithium-potassium chloride of eutectic melting composition, is expected to provide a material with favorable ion-exchange properties for the treatment of the waste salt. The authors constructed a pilot-plant system for the ion-exchange column. Initial results indicate that there is a direct relationship between the two operating variable of interest, temperature, and initial sodium concentration. Also, the mass ratio has been about 3--5 to bring the sodium concentration of the effluent below 1 mol%

  9. 4-(1H-Tetrazol-5-ylpyridinium chloride

    Directory of Open Access Journals (Sweden)

    Yan-Wei Zhang

    2010-12-01

    Full Text Available In the cation of the title compound, C6H6N5+·Cl−, the tetrazole and pyridine rings are nearly coplanar, making a dihedral angle of 5.58 (11°. The organic cations are linked to the chloride anions via N—H...Cl hydrogen bonds, forming chains along [110].

  10. Reaction of uranium dioxide with copper-containing chloride melts

    International Nuclear Information System (INIS)

    Cermet composition materials consisting of metallic copper and uranium dioxide can be used for manufacturing fuel rods of nuclear power reactors. Reprocessing of such irradiated fuel of dispersive type can be done employing non-aqueous pyrochemical methods and developing such technology requires information on interaction of uranium dioxide with chloride melts containing copper ions

  11. REMOVAL OF CHLORIDE FROM ACIDIC SOLUTIONS USING NO2

    International Nuclear Information System (INIS)

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

  12. 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.

  13. Sulfation of Condensed Potassium Chloride by SO2

    DEFF Research Database (Denmark)

    Sengeløv, Louise With; Hansen, Troels Bruun; Bartolomé, Carmen; Wu, Hao; Pedersen, Kim H.; Jappe Frandsen, Flemming; Jensen, Anker Degn; Glarborg, Peter

    2013-01-01

    The interaction between alkali chloride and sulfur oxides has important implications for deposition and corrosion in combustion of biomass. In the present study, the sulfation of particulate KCl (90–125 μm) by SO2 was studied in a fixed bed reactor in the temperature range 673–1023 K and with rea...

  14. Sodium Chloride Dihydrate - A Potential Cause of Slippery Accidents

    DEFF Research Database (Denmark)

    Mejlholm, Morten; Thomsen, Kaj; Rasmussen, Peter;

    From a thermodynamic point of view, it can be expected that sodium chloride dihydrate (hydrohalite, NaCl2H2O) will form on winter roads under certain conditions at temperatures below 0.1¢®C. In order to elucidate whether or not the formation of hydrohalite on the pavement can explain the phenomenon...

  15. Analysis of Yucca Mountain Pore-Water Chloride Data

    International Nuclear Information System (INIS)

    Distribution of chemical constituents in the unsaturated zone (UZ) system of Yucca Mountain, Nevada, depends on many factors, such as hydrological and geochemical processes of surface precipitation, evapotranspiration, the water-fracture-matrix interactions, large-scale mixing via lateral flow and transport, and the history of climate changes. This study analyzes pore-water chloride-concentration data and models the transport processes. The model results are then used to calibrate the UZ flow model with the aim of refining the infiltration distribution and percolation fluxes to the potential repository. The major chemical data used in this study were pore-water chloride (Cl) concentrations. The sensitivity of this conservative tracer to the UZ flow system is well known. This constituent was directly incorporated into a three-dimensional dual-permeability flow model. Chemical transport properties were taken into account. The surface flux of chloride was determined by the total amount of precipitation reaching the surface and chemical concentration in the precipitation. The entire flow system was divided into domains based on the distribution of pore-water chemical data, infiltration data, hydrogeological and hydrostructural features. Model calibration proceeded by adjusting the site-scale infiltration map and anisotropy permeabilities to reach a satisfying agreement between the simulated subsurface chloride distribution and measured data

  16. Electrodeposition of cerium from aqueous cerous chloride solutions

    International Nuclear Information System (INIS)

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

  17. Synthesis and characterization of uranium(VI) chloride fluorides

    International Nuclear Information System (INIS)

    Uranium (VI) chloride fluorides were synthesized by the reaction of liquid HCl and solid UF6 between -80 and -114 deg C. These dark red compounds are unstable above -40 to -60 deg C. The simplest formulas derived from compositional analysis are UF5Cl and UF4Cl2. (author)

  18. 21 CFR 862.1170 - Chloride test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Chloride test system. 862.1170 Section 862.1170 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems §...

  19. Mass-spectrometric investigation of thermochemical properties of lanthanide chlorides

    Energy Technology Data Exchange (ETDEWEB)

    Sapegin, A.M.; Baluev, A.V.; Evdokimov, V.I. (AN SSSR, Chernogolovka. Inst. Novykh Khimicheskikh Problem)

    1984-12-01

    Ionization potentials are measured for ions formed during lanthanide chloride molecules ionization by an electron shock with the use of the improved technique of mass-spectral data processing. Energies of atomization and atomic bond scission in molecules of tri-, di-, and monochlorides are defined along with enthalpies of formation of these molecules in a gaseous state.

  20. Mass-spectrometric investigation of thermochemical properties of lanthanide chlorides

    International Nuclear Information System (INIS)

    Ionization potentials are measured for ions formed during lanthanide chloride molecules ionization by an electron shock with the use of the improved technique of mass-spectral data processing. Energies of atomization and atomic bond scission in molecules of tri-, di-, and monochlorides are defined along with enthalpies of formation of these molecules in a gaseous state

  1. Study on the Reaction Mechanism of Naphthalene with Oxalyl Chloride

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The reaction of naphthalene with oxalyl chloride in the presence of anhydrous AlCl3 was investigated. The homolog of dinaphthyl methanone can be obtained mainly from this reaction. Naphthalene conversion does not have evident correlation with the amount of AlCl3. The results show that the reaction proceeds via carbon cation electrophilic substitution reaction-free radical substitution reaction pathway.

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

    DEFF Research Database (Denmark)

    Skøtt, O; Jensen, B L

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

  3. Polyvinyl chloride catheters with repressed migration of plasticizers

    Czech Academy of Sciences Publication Activity Database

    Sedláček, T.; Polášková, M.; Kašpárková, V.; Filip, Petr; Sáha, P.

    Larnaca : Polymer Processing Society, 2009, s. 243. [Polymer Processing Society Europe/Africa Regional Meeting. Larnaca (GR), 18.10.2009-21.10.2009] Institutional research plan: CEZ:AV0Z20600510 Keywords : Polyvinyl chloride * catheter * repressed migration of plasticizers Subject RIV: BK - Fluid Dynamics

  4. Disposable sensor for electrochemical determination of chloride ions.

    Science.gov (United States)

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

    2016-08-01

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

  5. (tert-Butyl)(2-hydroxyethyl)ammonium chloride

    OpenAIRE

    Cintya Valerio-Cárdenas; Simón Hernández-Ortega; David Morales-Morales

    2014-01-01

    In the cation of the title molecular salt, C6H16NO+·Cl−, the N—C—C—O torsion angle is 176.5 (2)°. In the crystal, the cations and chloride ions are linked by N—H...O and O—H...O hydrogen bonds, generating a two-dimensional network parallel to (100).

  6. Aqueous Chloride Operations Overview: Plutonium and Americium Purification/Recovery

    Energy Technology Data Exchange (ETDEWEB)

    Kimball, David Bryan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Skidmore, Bradley Evan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-06-22

    Acqueous Chloride mission is to recover plutonium and americium from pyrochemical residues (undesirable form for utilization and storage) and generate plutonium oxide and americium oxide. Plutonium oxide is recycled into Pu metal production flowsheet. It is suitable for storage. Americium oxide is a valuable product, sold through the DOE-OS isotope sales program.

  7. A chronopotentiometric approach for measuring chloride ion concentration

    NARCIS (Netherlands)

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

    2013-01-01

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

  8. Preparation of pure uranyl chloride from crude yellow cake

    International Nuclear Information System (INIS)

    A process is described for the preparation of pure uranyl chloride solution from crude yellow cake. The process involves dissolution of the latter in hydrochloric acid followed by uranium extraction using TBP-kerosene mixture. A series of experiments were carried out in order to determine the optimum conditions for both the dissolution and the extraction steps

  9. 21 CFR 184.1845 - Stannous chloride (anhydrous and dihydrated).

    Science.gov (United States)

    2010-04-01

    .... (b) Both forms of the ingredient meet the specifications of the Food Chemicals Codex, 3d Ed. (1981... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Stannous chloride (anhydrous and dihydrated). 184.1845 Section 184.1845 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND...

  10. Application and comparison of cocrystallization techniques on trospium chloride cocrystals

    Czech Academy of Sciences Publication Activity Database

    Sládková, V.; Cibulková, J.; Eigner, V.; Šturc, A.; Kratochvíl, B.; Rohlíček, Jan

    2014-01-01

    Roč. 14, č. 6 (2014), s. 2931-2936. ISSN 1528-7483 Institutional support: RVO:68378271 Keywords : cocrystal * cocrystallization methods * x-ray diffraction * x-ray powder diffraction * trospium chloride Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 4.891, year: 2014

  11. Barium borohydride chlorides: synthesis, crystal structures and thermal properties.

    Science.gov (United States)

    Grube, Elisabeth; Olesen, Cathrine H; Ravnsbæk, Dorthe B; Jensen, Torben R

    2016-05-10

    Here we report the synthesis, mechanism of formation, characterization and thermal decomposition of new barium borohydride chlorides prepared by mechanochemistry and thermal treatment of MBH4-BaCl2, M = Li, Na or K in ratios 1 : 1 and 1 : 2. Initially, orthorhombic barium chloride, o-BaCl2 transforms into o-Ba(BH4)xCl2-x, x ∼ 0.15. Excess LiBH4 leads to continued anion substitution and a phase transformation into hexagonal barium borohydride chloride h-Ba(BH4)xCl2-x, which accommodates higher amounts of borohydride, possibly x ∼ 0.85 and resembles h-BaCl2. Thus, two solid solutions are in equilibrium during mechano-chemical treatment of LiBH4-BaCl2 (1 : 1) whereas LiBH4-BaCl2 (2 : 1) converts to h-Ba(BH4)0.85Cl1.15. Upon thermal treatment at T > ∼200 °C, h-Ba(BH4)0.85Cl1.15 transforms into another orthorhombic barium borohydride chloride compound, o-Ba(BH4)0.85Cl1.15, which is structurally similar to o-BaBr2. The samples with M = Na and K have lower reactivity and form o-Ba(BH4)xCl2-x, x ∼ 0.1 and a solid solution of sodium chloride dissolved in solid sodium borohydride, Na(BH4)1-xClx, x = 0.07. The new compounds and reaction mechanisms are investigated by in situ synchrotron radiation powder X-ray diffraction (SR-PXD), Fourier transform infrared spectroscopy (FT-IR) and simultaneous thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), mass spectroscopy (MS) and temperature programmed photographic analysis (TPPA). PMID:27109871

  12. Chloride channels and the reactions of cells to topography

    Directory of Open Access Journals (Sweden)

    Tobasnick G.

    2001-12-01

    Full Text Available The reactions of rat epitenon cells to substratum topography on the micrometric and nanometric scale such as groove-ridge structures include cell extension, elongation and orientation reactions. In this paper we report that stretch-sensitive chloride channels may be involved in the earliest stages of these reactions in epitenon fibroblast-like cells. We report that rat epitenon-cells can develop appreciable lateral mechanical tension that could stretch both the force generating cells themselves and those nearby. We show that cells in medium in which more than 80% of the chloride has been replaced by nitrate show little reaction to topography. Spreading of the cells takes place but is much reduced along the direction of the groove-ridge topography but enhanced across the topography. The chloride channel inhibitors NPPB (5-Nitro-2- (3phenylpropylamino benzoicacid 4,4'-disothiocyanostilbene-2, 2' sulphonic acid (DIDS and Chlorotoxin produce similar results which are further accentuated when these inhibitors are presented in low chloride medium. An antibody against ClC3, which has close homology to ClC5/6 also, blocked reaction to topography. These treatments have no significant effect on cell spreading on planar surfaces nor do they lead to changes in internal pH in the cells. There is a slight inhibition of rates of cell movement . Experiments using antisense oligoribonucleotides to ClC-5 or ClC-6 channel m-RNA also inhibit topographic reactions, which provides further confirmation of the hypothesis. Since the ClC-3,4 and 5 share considerable sequence similarities in the genes and in their proteins it has not been possible to make an unambigous determination of which precise chloride channel(s is (are involved.

  13. Reconnaissance Estimates of Recharge Based on an Elevation-dependent Chloride Mass-balance Approach

    Energy Technology Data Exchange (ETDEWEB)

    Charles E. Russell; Tim Minor

    2002-08-31

    Significant uncertainty is associated with efforts to quantity recharge in arid regions such as southern Nevada. However, accurate estimates of groundwater recharge are necessary to understanding the long-term sustainability of groundwater resources and predictions of groundwater flow rates and directions. Currently, the most widely accepted method for estimating recharge in southern Nevada is the Maxey and Eakin method. This method has been applied to most basins within Nevada and has been independently verified as a reconnaissance-level estimate of recharge through several studies. Recharge estimates derived from the Maxey and Eakin and other recharge methodologies ultimately based upon measures or estimates of groundwater discharge (outflow methods) should be augmented by a tracer-based aquifer-response method. The objective of this study was to improve an existing aquifer-response method that was based on the chloride mass-balance approach. Improvements were designed to incorporate spatial variability within recharge areas (rather than recharge as a lumped parameter), develop a more defendable lower limit of recharge, and differentiate local recharge from recharge emanating as interbasin flux. Seventeen springs, located in the Sheep Range, Spring Mountains, and on the Nevada Test Site were sampled during the course of this study and their discharge was measured. The chloride and bromide concentrations of the springs were determined. Discharge and chloride concentrations from these springs were compared to estimates provided by previously published reports. A literature search yielded previously published estimates of chloride flux to the land surface. {sup 36}Cl/Cl ratios and discharge rates of the three largest springs in the Amargosa Springs discharge area were compiled from various sources. This information was utilized to determine an effective chloride concentration for recharging precipitation and its associated uncertainty via Monte Carlo simulations

  14. Chloride transport in a glioma cell line

    Energy Technology Data Exchange (ETDEWEB)

    Wolpaw, E.W.

    1984-01-01

    Maintenance of the extracellular environment is a major function of central nervous system astroglia. The transport of Cl/sup -/ across the cell membrane may be an integral part of this function, since Cl/sup -/ transport has been implicated in homeostasis of cell volume, pH, and extracellular K/sup +/ concentration. The work presented here investigated Cl/sup -/ transport in the glioma cell line LRM55. Results indicate that LRM55 cells are a good model for astroglia and that these cells contain three Cl/sup -/ transporters; a Cl/sup -//HCO/sub 3//sup -/ exchanger, a K/sup +//Cl/sup -/ cotransporter, and a Cl/sup -//SO/sub 4//sup 2 -/ exchanger. Ion transport studies measured the fluxes of Cl/sup -/ (as /sup 36/Cl/sup -/), K/sup +/ (as /sup 86/Rb/sup +/), and SO/sub 4//sup 2 -/ (as /sup 35/SO/sub 4//sup 2 -/). Cl/sup -/ flux was trans-simulated by Cl/sup -/ or HCO/sub 3//sup -/ and was inhibited by SITS or furosemide. External K/sup +/ stimulated Cl/sup -/ influx and external Cl/sup -/ stimulated Rb/sup +/ influx. Furosemide, but not SITS, inhibited the K/sup +//Cl/sup -/ cotransporter. High K/sup +/ medium increased cell volume and Cl/sup -/ content. Steady-state Cl/sup -/ concentration was at least twice that predicted from passive equilibration according to the Nernst equation. SO/sub 4//sup 2 -/ flux was trans-stimulated by SO/sub 4//sup 2 -/ or by Cl/sup -/. Cl/sup -/ was a competitive inhibitor of SO/sub 4//sup 2 -/ influx, but SO/sub 4//sup 2 -/ had no detectable effect on Cl/sup -/ influx or efflux. SO/sub 4//sup 2 -/ flux was inhibited by SITS or furosemide.

  15. Properties of a conductive cellular chloride pathway in the skin of the toad (Bufo bufo)

    DEFF Research Database (Denmark)

    Larsen, Erik Hviid; Kristensen, P

    1978-01-01

    -compartment model indicate that the strong steady-state chloride current rectification cannot be obtained if only the intracellular chloride concentration and the membrane potentials are allowed to vary ("Goldman-rectification"). It is suggested, therefore, that the premeability of the chloride pathway varies...... steady-state conductance and the steady-state chloride current reveal that the chloride pathway has maximum conductance for V approximately -80 mV (outside of the skin being negative) and approaches a non-conducting safe for V greater than 0 mV. This strong outward going rectification is a steady......-state phenomenon: In skins hyperpolarized for a few minutes, the "instantaneous" I-V curves show that the chloride pathway in the conducting state allows a large inward chloride current (outward chloride flux) to pass in the voltage range 40 mV greater than V greater than 0 mV. Calculations based on a three...

  16. The chloride channel inhibitor NS3736 [corrected] prevents bone resorption in ovariectomized rats without changing bone formation

    DEFF Research Database (Denmark)

    Schaller, Sophie; Henriksen, Kim; Sveigaard, Christina;

    2004-01-01

    Chloride channel activity is essential for osteoclast function. Consequently, inhibition of the osteoclastic chloride channel should prevent bone resorption. Accordingly, we tested a chloride channel inhibitor on bone turnover and found that it inhibits bone resorption without affecting bone form...

  17. SEPARATION OF MAGNESIUM CHLORIDE FROM SEA WATER BY PREFERENTIAL SALT SEPARATION (PSS)

    OpenAIRE

    Khaled Zohdy, Maha Abdel Kareem and Hussein Abdel-Aal*

    2013-01-01

    Magnesium chloride is typically extracted from sea water on an industrial scale by precipitating it as magnesium hydroxide, then converting it to the chloride by adding hydrochloric acid. This process is known as the Dow process which uses the chemical approach in producing magnesium chloride. Kettani and Abdel-Aal [1], proposed a physical separation procedure known as the Preferential Salt Separation (PSS) to obtain magnesium chloride directly from sea water. In principle, the PSS concept is...

  18. ENHANCEMENT OF CHLORIDE RESISTANCE OF PRE-STRESSED CONCRETE SHEET PILE BY BLAST FURNACE SLAG

    OpenAIRE

    Irmawaty, Rita

    2012-01-01

    Chloride-induced corrosion is one of the main mechanisms of deterioration affecting the long-term performance of concrete structures. In Japan, a large majority of structures are built either near the costal or indirect contact with seawater. The durability of reinforced or pre-stressed concrete structure depends on the resistance of concrete to chloride penetration. Naturally concrete provides physical and chemical protection to the reinforcing steel from chloride penetrating. The chloride ...

  19. Higher serum chloride concentrations are associated with acute kidney injury in unselected critically ill patients

    OpenAIRE

    Zhang, Zhongheng; Xu, Xiao; Fan, Haozhe; Li, Danyu; Deng, Hongsheng

    2013-01-01

    Background Chloride administration has been found to be harmful to the kidney in critically ill patients. However the association between plasma chloride concentration and renal function has never been investigated. Methods This was a retrospective study conducted in a tertiary 24-bed intensive care unit from September 2010 to November 2012. Data on serum chloride for each patient during their ICU stay were abstracted from electronic database. Cl0 referred to the initial chloride on ICU entry...

  20. Cytogenetic Effects of Copper Chloride on the Root Tip Cells of Helianthus annuus L.

    OpenAIRE

    İNCEER, Hüseyin; AYAZ, Sema; BEYAZOĞLU, Osman; ŞENTÜRK, Emine

    2003-01-01

    The cytogenetic effects of copper chloride on root tip cells of Helianthus annuus were investigated. Seeds were treated with 10, 25, 50 and 100 mg/L (ppm) of copper chloride for 24 h. It was found that copper chloride has a marked mitodepressive action on mitosis. Mitotic abnormalities were increased and the mitotic index was decreased depending on the concentration of the copper chloride applied.

  1. Selective Reduction of Active Metal Chlorides from Molten LiCl-KCl using Lithium Drawdown

    Energy Technology Data Exchange (ETDEWEB)

    Michael F. Simpson; Daniel LaBrier; Michael Lineberry; Tae-Sic Yoo

    2012-10-01

    In support of optimizing electrorefining technology for treating spent nuclear fuel, lithium drawdown has been investigated for separating actinides from molten salt electrolyte. Drawdown reaction selectivity is a major issue that needs to be investigated, since the goal is to remove actinides while leaving the fission products in the salt. A series of lithium drawdown tests with surrogate fission product chlorides was run to obtain selectivity data with non-radioactive salts, develop a predictive model, and draw conclusions about the viability of using this process with actinide-loadd salt. Results of tests with CsCl, LaCl3, CeCl3, and NdCl3 are reported here. An equilibrium model has been formulated and fit to the experimental data. Excellent fits to the data were achieved. Based on analysis and results obtained to date, it is concluded that clean separation between minor actinides and lanthanides will be difficult to achieve using lithium drawdown.

  2. Thermodynamic stability and structure of cuprous chloride surfaces: a DFT investigation.

    Science.gov (United States)

    Suleiman, Ibrahim A; Radny, Marian W; Gladys, Michael J; Smith, Phillip V; Mackie, John C; Kennedy, Eric M; Dlugogorski, Bogdan Z

    2015-03-14

    Density functional theory together with ab initio atomistic thermodynamics has been utilized to study the structures and stabilities of the low index CuCl surfaces. It is shown that the Cl-terminated structures are more stable than the Cu-terminated configurations, and that the defective CuCl(110)-Cu structure is more stable than the stoichiometric CuCl(110) surface. The equilibrium shape of a cuprous chloride nanostructure terminated by low-index CuCl surfaces has also been predicted using a Wulff construction. It was found that the (110) facets dominate at low chlorine concentration. As the chlorine concentration is increased, however, the contributions of the (100) and (111) facets to the Wulff construction also increase giving the crystal a semi-prism shape. At high chlorine concentration, and close to the rich limit, the (111) facets were found to be the only contributors to the Wulff construction, resulting in prismatic nanocrystals. PMID:25687716

  3. Modeling the Use of Sulfate Additives for Potassium Chloride Destruction in Biomass Combustion

    DEFF Research Database (Denmark)

    Wu, Hao; Pedersen, Morten Nedergaard; Jespersen, Jacob Boll;

    2014-01-01

    Potassium chloride, KCl, formed from biomass combustion may lead to ash deposition and corrosion problems in boilers. Sulfates are effective additives for converting KCl to the less harmful K2SO4 and HCl. In the present study, the rate constants for decomposition of ammonium sulfate and aluminum......-dependent distribution of SO2 and SO3 from ammonium sulfate decomposition. On the basis of these data as well as earlier results, a detailed chemical kinetic model for sulfation of KCl by a range of sulfate additives was established. Modeling results were compared to biomass combustion experiments in a bubbling...... fluidized-bed reactor using ammonium sulfate, aluminum sulfate, and ferric sulfate as additives. The simulation results for ammonium sulfate and ferric sulfate addition compared favorably to the experiments. The predictions for aluminum sulfate addition were only partly in agreement with the experimental...

  4. Shear performance of reinforced concrete beams with corroded stirrups in chloride environment

    International Nuclear Information System (INIS)

    Research highlights: → Simulation of the rebar corrosion in concrete in chloride aggressive environment. → The maximum corrosion-induced crack width increases with the average width. → The corrosion-induced crack width has a relationship with the corrosion level. → Shear capacity evaluation of the beam using the corrosion-induced crack width. - Abstract: Experiments were conducted for the investigation of the influence of reinforcing steel corrosion on the shear capacity of reinforced concrete beams. The shear performance of RC beams with different corrosion levels in both longitudinal reinforcing steel bars and stirrups was examined. Relationships of corrosion-induced crack widths in concrete cover with the corrosion level of the reinforcing steel bars were obtained. Engineering approaches were developed to predict the residual shear strength of the corroded beams.

  5. Shear performance of reinforced concrete beams with corroded stirrups in chloride environment

    Energy Technology Data Exchange (ETDEWEB)

    Xia Jin, E-mail: xiajin2008@gmail.co [Institute of Structural Engineering, Zhejiang University, Hangzhou 310058 (China); Jin Weiliang [Institute of Structural Engineering, Zhejiang University, Hangzhou 310058 (China); Li Longyuan [School of Civil Engineering, University of Birmingham, Birmingham B15 2TT (United Kingdom)

    2011-05-15

    Research highlights: Simulation of the rebar corrosion in concrete in chloride aggressive environment. The maximum corrosion-induced crack width increases with the average width. The corrosion-induced crack width has a relationship with the corrosion level. Shear capacity evaluation of the beam using the corrosion-induced crack width. - Abstract: Experiments were conducted for the investigation of the influence of reinforcing steel corrosion on the shear capacity of reinforced concrete beams. The shear performance of RC beams with different corrosion levels in both longitudinal reinforcing steel bars and stirrups was examined. Relationships of corrosion-induced crack widths in concrete cover with the corrosion level of the reinforcing steel bars were obtained. Engineering approaches were developed to predict the residual shear strength of the corroded beams.

  6. [Activity of Ca(2+)-dependent neutral proteinases in rat organs under cobalt and mercury chloride injection].

    Science.gov (United States)

    Kaliman, P A; Samokhin, A A; Samokhina, L M

    2003-01-01

    The activity of Ca(2+)-dependent neutral proteinases in rats under cobalt and mercury chloride injection was investigated. The calpains activity increase in the lungs, heart, liver and kidneys was revealed after 2 h cobalt chloride action. The mercury chloride gives a reliable increase of calcium-dependent neutral proteinases only in the kidneys. PMID:14574747

  7. 40 CFR 721.10154 - Quaternary ammonium compounds, dicoco alkyldimethyl, chlorides, reaction products with silica.

    Science.gov (United States)

    2010-07-01

    ... alkyldimethyl, chlorides, reaction products with silica. 721.10154 Section 721.10154 Protection of Environment..., dicoco alkyldimethyl, chlorides, reaction products with silica. (a) Chemical substance and significant..., dicoco alkyldimethyl, chlorides, reaction products with silica (PMN P-08-157; CAS No. 956147-76-5)...

  8. 46 CFR 154.1750 - Butadiene or vinyl chloride: Refrigeration system.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Butadiene or vinyl chloride: Refrigeration system. 154... and Operating Requirements § 154.1750 Butadiene or vinyl chloride: Refrigeration system. A refrigeration system for butadiene or vinyl chloride must not use vapor compression unless it: (a) Avoids...

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Liu Min, E-mail: panpanliumin@163.co [College of Chemistry and Chemical Engineering, Liao Cheng University, Liaocheng, Shandong 252059 (China); Wang Lili [College of Chemistry and Chemical Engineering, Liao Cheng University, Liaocheng, Shandong 252059 (China); Zhu Lanying [College of Life Science and Bioengineering, Liao Cheng University, Liaocheng, Shandong 252059 (China); Li Hui; Sun Dezhi; Di Youying; Li Linwei [College of Chemistry and Chemical Engineering, Liao Cheng University, Liaocheng, Shandong 252059 (China)

    2010-07-15

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

  11. Draft genome sequence of chloride-tolerant Leptospirillum ferriphilum Sp-Cl from industrial bioleaching operations in northern Chile.

    Science.gov (United States)

    Issotta, Francisco; Galleguillos, Pedro A; Moya-Beltrán, Ana; Davis-Belmar, Carol S; Rautenbach, George; Covarrubias, Paulo C; Acosta, Mauricio; Ossandon, Francisco J; Contador, Yasna; Holmes, David S; Marín-Eliantonio, Sabrina; Quatrini, Raquel; Demergasso, Cecilia

    2016-01-01

    Leptospirillum ferriphilum Sp-Cl is a Gram negative, thermotolerant, curved, rod-shaped bacterium, isolated from an industrial bioleaching operation in northern Chile, where chalcocite is the major copper mineral and copper hydroxychloride atacamite is present in variable proportions in the ore. This strain has unique features as compared to the other members of the species, namely resistance to elevated concentrations of chloride, sulfate and metals. Basic microbiological features and genomic properties of this biotechnologically relevant strain are described in this work. The 2,475,669 bp draft genome is arranged into 74 scaffolds of 74 contigs. A total of 48 RNA genes and 2,834 protein coding genes were predicted from its annotation; 55 % of these were assigned a putative function. Release of the genome sequence of this strain will provide further understanding of the mechanisms used by acidophilic bacteria to endure high osmotic stress and high chloride levels and of the role of chloride-tolerant iron-oxidizers in industrial bioleaching operations. PMID:26925196

  12. EVALUATION OF FERRIC CHLORIDE AND ALUM EFFICIENCIES IN ENHANCED COAGULATION FOR TOC REMOVAL AND RELATED RESIDUAL METAL CONCENTRATIONS

    Directory of Open Access Journals (Sweden)

    A. Mesdaghinia, M. T. Rafiee, F. Vaezi and A. H. Mahvi

    2005-07-01

    Full Text Available Although the removal of colloidal particles continues to be an important reason for using coagulation, a newer objective, the removal of natural organic matter (NOM to reduce the formation of disinfection by-products (DBPs, is growing in importance. Enhanced coagulation is thus introduced to most water utilities treating surface water. Bench-scale experiments were conducted to compare the effectiveness of alum and ferric chloride in removing DBPs precursors from eight synthetic water samples, each representing a different element of the USEPA’s 3×3 enhanced coagulation matrix. The effect of enhanced coagulation on the residual metal (aluminum/iron concentration in the treated water was assessed as well. The removal of total organic carbon (TOC was dependent on the coagulant type and was enhanced with increasing coagulant dose, but the latter had no further considerable effect in case of increasing to high levels. For all the treated samples coagulation with ferric chloride proved to be more effective than alum at similar doses and the mean values of treatment efficiencies were 51% and 32% for ferric chloride and alum, respectively. Ferric chloride was therefore considered the better chemical for enhancing the coagulation process. Besides, due to less production of sludge by this coagulant, it would be predicted that treatment plants would be confronted to fewer problems with respect to final sludge disposal. Measurements of residual metal in treated water indicated that iron and aluminum concentrations had been increased as expected but the quality of water concerning the residual metal deteriorated much more in cases of under-dosing. Despite expecting high residual Al and Fe concentrations under enhanced coagulation, metal concentrations were frequently remained low and were not increased appreciably.

  13. Density Functional Theory Study on Conformers of Benzoylcholine Chloride

    Directory of Open Access Journals (Sweden)

    Mustafa Karakaya

    2013-01-01

    Full Text Available The optimized molecular structures and vibrational frequencies and also gauge including atomic orbital (GIAO 1H and 13C NMR shift values of benzoylcholine chloride [(2-benzoyloxyethyl trimethyl ammonium chloride] have been calculated using density functional theory (B3LYP method with 6-31++G(d basis set. The comparison of the experimental and calculated infrared (IR, Raman, and nuclear magnetic resonance (NMR spectra has indicated that the experimental spectra are formed from the superposition of the spectra of two lowest energy conformers of the compound. So, it was concluded that the compound simultaneously exists in two optimized conformers in the ground state. Also the natural bond orbital (NBO analysis has supported the simultaneous exiting of two conformers in the ground state. The calculated optimized geometric parameters (bond lengths and bond angles and vibrational frequencies for both the lowest energy conformers were seen to be in a well agreement with the corresponding experimental data.

  14. 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.

  15. CPP-603 Chloride Removal System Decontamination and Decommissioning

    International Nuclear Information System (INIS)

    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

  16. INNA for interelement correlations in rats after mercuric chloride exposure

    International Nuclear Information System (INIS)

    In an animal model study, we exposed rats to mercuric chloride through drinking water continuously for eight to ten months. A group of these rats were then taken off mercuric chloride water and fed distilled water. A control group of rats was given distilled water. Rat brain, spinal cord, and kidney were analyzed to determine Hg and nine other elements by INAA. Significant imbalances were detected among the groups. Most of the mercury (Hg) was found to be eliminated from the tissues studied within the first thirty days. Implications of the data are discussed in light of observed trace element imbalances in amyotrophic lateral sclerosis and Alzheimer's disease. (author) 25 refs.; 1 fig.; 3 tabs

  17. CHLORIDE ION PERMEABILITY STUDIES OF METAKAOLIN BASED HIGH PERFORMANCE CONCRETE

    Directory of Open Access Journals (Sweden)

    Dr.Vaishali. G.Ghorpade,

    2011-02-01

    Full Text Available To increase the applications of HPC in India, greater under standing of HPC produced with locally available materials and indigenously produced mineral admixtures is essential. In the present investigation, HPC has been produced with locally available aggregates and metakaolin as the mineral admixture. Various metakaolin based HPC mixes were attained by absolute volume method. Cubes of 150X150X150 mm size were cast and cured for 28 days and then tested for compressive strength. Chloride ion permeability test as per ASTM C 1202 has been conducted on various HPC mixes to measure the permeability values of HPC produced with metakaolin. The experimental results indicate that metakaolin has the ability to considerably reduce the permeability of high performance concrete. The various details about the chloride ion permeability test have been presented in this paper.

  18. Sodium chloride's effect on self-assembly of diphenylalanine bilayer.

    Science.gov (United States)

    Kwon, Junpyo; Lee, Myeongsang; Na, Sungsoo

    2016-07-15

    Understanding self-assembling peptides becomes essential in nanotechnology, thereby providing a bottom-up method for fabrication of nanostructures. Diphenylalanine constitutes an outstanding building block that can be assembled into various nanostructures, including two-dimensional bilayers or nanotubes, exhibiting superb mechanical properties. It is known that the effect of the ions is critical in conformational and chemical interactions of bilayers or membranes. In this study, we analyzed the effect of sodium chloride on diphenylalanine bilayer using coarse-grained molecular dynamics simulations, and calculated the bending Young's modulus and the torsional modulus by applying normal modal analysis using an elastic network model. The results showed that sodium chloride dramatically increases the assembling efficiency and stability, thereby promising to allow the precise design and control of the fabrication process and properties of bio-inspired materials. © 2016 Wiley Periodicals, Inc. PMID:27241039

  19. Inhibition of intestinal chloride secretion by proanthocyanidins from Guazuma ulmifolia.

    Science.gov (United States)

    Hör, M; Rimpler, H; Heinrich, M

    1995-06-01

    The antisecretory activity of Guazuma ulmifolia bark was examined in rabbit distal colon mounted in an Ussing chamber. Chloride secretion was stimulated by cholera toxin and prostaglandin E2 (PGE2). Guazuma ulmifolia extract (GUE) completely inhibited cholera toxin-induced secretion if the extract was added to the mucosal bath prior to the toxin. Adding the extract after administration of the toxin had no effect on secretion. GUE did not inhibit PGE2-induced chloride secretion. These results indicate an indirect antisecretory mechanism. SDS-PAGE analysis of cholera toxin treated with GUE confirmed this presumption. GUE specifically interacted with the A subunit of the toxin. Preliminary phytochemical examinations showed that the most active fraction contains procyanidins with a degree of polymerisation higher than 8. PMID:7617760

  20. Electrochemical synthesis and characterization of chloride doped polyaniline

    Indian Academy of Sciences (India)

    A M Pharhad Hussain; A Kumar

    2003-04-01

    Chloride doped polyaniline conducting polymer films have been prepared in a protic acid medium (HCl) by potentiodynamic method in an electrochemical cell and studied by cyclic voltammetry and FTIR techniques. The FTIR spectra confirmed Cl– ion doping in the polymers. The polymerization rate was found to increase with increasing concentration of aniline monomer. But the films obtained at high monomer concentration were rough having a nonuniform flaky polyaniline distribution. Results showed that the polymerization rate did not increase beyond a critical HCl concentration. Cyclic voltammetry suggested that, the oxidation-reduction current increased with an increase in scan rate and that the undoped polyaniline films were not hygroscopic whereas chloride doped polyaniline films were found to be highly hygroscopic.

  1. Electrowinning of lead powder from chloride leach liquor

    Energy Technology Data Exchange (ETDEWEB)

    Owais, Ashour [Suez Canal Univ., Suez (Egypt). Metallurgical and Materials Engineering Dept.

    2012-11-15

    Electrowinning of lead powder from chloride leach liquor obtained from secondary lead slag leached in hydrochloric acid is the main aim of this work. The resulted lead chloride solution (leachate) containing 2.2 wt.-% Pb and 1.24 wt.-% HCl was electrowon in an electrolytic cell containing one graphite plate as inert anode and two lead sheets as starting permanent cathodes. Different electrolysis parameters such as current density, electrolyte temperature and electrolyte stirring rate were studied. As indicated by SEM, EDX and XRD analyses, fine and pure (100 % Pb) powders with a dispersed and needle-like shape were formed with cathodic current efficiency up to 67.9 % and electrical energy demand ranges from 0.809 to 4.998 kWh/kg Pb with productivity up to 2.63 g/Ah. (orig.)

  2. A software prototype for assessing the reliability of a concrete bridge superstructure subjected to chloride-induced reinforcement corrosion

    DEFF Research Database (Denmark)

    Schneider, Ronald; Thöns, Sebastian; Fischer, Johannes;

    2014-01-01

    through Bayesian updating on the basis of the DBN model. To demonstrate the effect of partial inspections, the software prototype is applied to a case study of a typical highway bridge with six spans. The case study illustrates that it is possible to infer the condition of uninspected parts of the......A software prototype is developed for assessing and updating the reliability of single-cell prestressed concrete box girders subjected to chloride-induced reinforcement corrosion. The underlying system model consists of two integrated sub-models: a condition model for predicting the deterioration...

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

    Institute of Scientific and Technical Information of China (English)

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

    2004-01-01

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

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

    Indian Academy of Sciences (India)

    J Mathiyarasu; N Palaniswamy; V S Muralidharan

    2001-02-01

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

  5. Processes of lithium chlorides purification from Salar de Atacama concentrated brines

    International Nuclear Information System (INIS)

    The results of research carried out to obtain lithium chloride, as a suitable electrolyte for the production of high purity lithium metal are presented. Concentrated lithium chloride brines from Salar de Atacama have been used as starting materials. The studied process requires the reduction of the boron content in the brines to levels below 5 ppm, followed by a crystallization process to obtain a crystallized lithium chloride. The elimination of the magnesium chloride co-crystallized with the lithium chloride, is achieved by a complementary washing step and the lixiviation of the impure LiCl crystals with ethanol. (author)

  6. Antidepressants and seizure-interactions at the GABA-receptor chloride-ionophore complex

    International Nuclear Information System (INIS)

    Convulsive seizures are a potential side effect of antidepressant drug treatment and can be produced by all classes of antidepressants. It is also know that some convulsant and anticonvulsant drug actions are mediated by the GABA-receptor chloride-ionophore complex. Drugs acting at this complex appear to induce convulsions by inhibiting chloride conductance through the associated chloride channel. Using the method of GABA-stimulated 36Cl-uptake by rat cerebral cortical vesicles, we show that some antidepressant drugs can inhibit the GABA-receptor chloride uptake, and that the degree of chloride channel inhibition by these drugs correlates with the frequency of convulsive seizures induced by them

  7. Structural and mechanistic studies of chloride induced activation of human pancreatic α-amylase

    OpenAIRE

    Maurus, Robert; Begum, Anjuman; Kuo, Hsin-Hen; Racaza, Andrew; Numao, Shin; Andersen, Carsten; Tams, Jeppe W.; Vind, Jesper; Overall, Christopher M.; Withers, Stephen G.; Brayer, Gary D

    2005-01-01

    The mechanism of allosteric activation of α-amylase by chloride has been studied through structural and kinetic experiments focusing on the chloride-dependent N298S variant of human pancreatic α-amylase (HPA) and a chloride-independent TAKA-amylase. Kinetic analysis of the HPA variant clearly demonstrates the pronounced activating effect of chloride ion binding on reaction rates and its effect on the pH-dependence of catalysis. Structural alterations observed in the N298S variant upon chlorid...

  8. Studies of Degradation of Plasticized Polyvinyl Chloride (PPVC)

    OpenAIRE

    Doina Elena Gavrilă

    2016-01-01

    Commercial plasticizers are introduced in Polyvinyl Chloride (PVC) to obtain flexibility, high elongation to break, durability, resistance to heat and chemicals. Very used plasticizers are phthalates, most commonly phthalate being di-2-ethyl hexyl phthalate (DEHP). The phthalates are not chemically bound to PVC and can migrate from different devices and objects due to the influence of temperature, or to other types of degradation. In article are presented the harm effects of phtha...

  9. Melt supercooling and growth of lead chloride single crystals

    Czech Academy of Sciences Publication Activity Database

    Nitsch, Karel; Cihlář, Antonín; Rodová, Miroslava

    Bratislava: NOI, 2003 - (Koman, M.; Miklos, D.), s. 49-50 ISBN 80-89088-16-3. [Joint Seminar DMS -RE 2003 /13./. Račkova dolina (SK), 15.09.2003-19.09.2003] R&D Projects: GA ČR GA202/03/0428 Institutional research plan: CEZ:AV0Z1010914 Keywords : crystal growth * lead chloride * Bridgman method * length of supercool region Subject RIV: BM - Solid Matter Physics ; Magnetism

  10. Bis[1,2-bis(dimethylphosphinoethane]dichloridonitrosyltungsten(0 chloride

    Directory of Open Access Journals (Sweden)

    Nataša Avramović

    2008-01-01

    Full Text Available In the crystal structure of the title compound, [WCl2(NO(C6H16P22]Cl, the seven-coordinated tungsten(II center displays a distorted pentagonal–bipyramidal geometry with trans nitrosyl and chloride ligands. The NO and Cl ligands are disordered over two positions; the site occupancy factors are 0.6 and 0.4.

  11. Influence of sodium chloride on wine yeast fermentation performance

    OpenAIRE

    Logothetis, Stelios

    2010-01-01

    Stilianos Logothetis1, Elias T Nerantzis2, Anna Gioulioti3, Tasos Kanelis2, Tataridis Panagiotis2, Graeme Walker11University of Abertay Dundee, School of Contemporary Sciences, Dundee, Scotland; 2TEI of Athens Department of Oenology and Spirit Technology, Biotechnology and Industrial Fermentations Lab Agiou Spiridonos, Athens, Greece; 3Ampeloiniki SA Industrial Park Thermi, Thessaloniki, GreeceAbstract: This paper concerns research into the influence of salt (sodium chloride) on growth, viabi...

  12. Sequential injection titration of chloride in milk with potentiometric detection

    OpenAIRE

    Lima, M.J. Reis; Fernandes, Sílvia M. V.; Rangel, António O.S.S.

    2004-01-01

    In this work, a sequential injection system for the pseudo-titration of chloride in milk is described. Milk was directly aspirated into the system and sandwiched between two silver nitrate plugs (titrant). The aspirated zones were then propelled to the detector (Ag2S/Ag tubular electrode), where the depletion in the titrant silver concentration (due to the formation of a AgCl precipitate) was monitored. The results obtained by the developed sequential injection titration method were ...

  13. Thionyl-chloride-induced lung injury and bronchiolitis obliterans

    Energy Technology Data Exchange (ETDEWEB)

    Konichezky, S.; Schattner, A.; Ezri, T.; Bokenboim, P.; Geva, D. (Kaplan Hospital, Rehovot (Israel))

    1993-09-01

    Thionyl-chloride (TCl) is used in the manufacture of lithium batteries, producing SO2 and HCl fumes on contact with water. We report two cases of accidental TCl exposure resulting in lung injury that may vary from a relatively mild and reversible interstitial lung disease to a severe form of bronchiolitis obliterans causing, after a latent period, an acute/chronic respiratory failure as well as other complications (spontaneous pneumothorax and bronchopleural fistula), previously unreported in TCl fume inhalation.

  14. Polarization and charge transfer in the hydration of chloride ions

    International Nuclear Information System (INIS)

    A theoretical study of the structural and electronic properties of the chloride ion and water molecules in the first hydration shell is presented. The calculations are performed on an ensemble of configurations obtained from molecular dynamics simulations of a single chloride ion in bulk water. The simulations utilize the polarizable AMOEBA force field for trajectory generation and MP2-level calculations are performed to examine the electronic structure properties of the ions and surrounding waters in the external field of more distant waters. The ChelpG method is employed to explore the effective charges and dipoles on the chloride ions and first-shell waters. The quantum theory of atoms in molecules (QTAIM) is further utilized to examine charge transfer from the anion to surrounding water molecules. The clusters extracted from the AMOEBA simulations exhibit high probabilities of anisotropic solvation for chloride ions in bulk water. From the QTAIM analysis, 0.2 elementary charges are transferred from the ion to the first-shell water molecules. The default AMOEBA model overestimates the average dipole moment magnitude of the ion compared to the quantum mechanical value. The average magnitude of the dipole moment of the water molecules in the first shell treated at the MP2-level, with the more distant waters handled with an AMOEBA effective charge model, is 2.67 D. This value is close to the AMOEBA result for first-shell waters (2.72 D) and is slightly reduced from the bulk AMOEBA value (2.78 D). The magnitude of the dipole moment of the water molecules in the first solvation shell is most strongly affected by the local water-water interactions and hydrogen bonds with the second solvation shell, rather than by interactions with the ion.

  15. Polarization and charge transfer in the hydration of chloride ions

    Science.gov (United States)

    Zhao, Zhen; Rogers, David M.; Beck, Thomas L.

    2010-01-01

    A theoretical study of the structural and electronic properties of the chloride ion and water molecules in the first hydration shell is presented. The calculations are performed on an ensemble of configurations obtained from molecular dynamics simulations of a single chloride ion in bulk water. The simulations utilize the polarizable AMOEBA force field for trajectory generation and MP2-level calculations are performed to examine the electronic structure properties of the ions and surrounding waters in the external field of more distant waters. The ChelpG method is employed to explore the effective charges and dipoles on the chloride ions and first-shell waters. The quantum theory of atoms in molecules (QTAIM) is further utilized to examine charge transfer from the anion to surrounding water molecules. The clusters extracted from the AMOEBA simulations exhibit high probabilities of anisotropic solvation for chloride ions in bulk water. From the QTAIM analysis, 0.2 elementary charges are transferred from the ion to the first-shell water molecules. The default AMOEBA model overestimates the average dipole moment magnitude of the ion compared to the quantum mechanical value. The average magnitude of the dipole moment of the water molecules in the first shell treated at the MP2-level, with the more distant waters handled with an AMOEBA effective charge model, is 2.67 D. This value is close to the AMOEBA result for first-shell waters (2.72 D) and is slightly reduced from the bulk AMOEBA value (2.78 D). The magnitude of the dipole moment of the water molecules in the first solvation shell is most strongly affected by the local water-water interactions and hydrogen bonds with the second solvation shell, rather than by interactions with the ion.

  16. Chloride transport through cementitious membranes using pulsed current

    OpenAIRE

    Diaz, B.; Novoa, X.Ramon; Puga, Beatriz; Vivier, Vincent

    2013-01-01

    International audience Microstructural changes and chloride transport in cement pastes are studied under DC current and pulsed electric fields. Impedance spectroscopy and ultrasonic pulse velocity measurements have been employed for quasi-real time monitoring of changes in the cement paste microstructure. The results show that the electric resistivity and ultrasound velocity (measured at 500 kHz) are modified during the migration experiments. At the end of test, mercury intrusion porosimet...

  17. Hibiscus sabdariffa Affects Ammonium Chloride-Induced Hyperammonemic Rats

    OpenAIRE

    Subramanian, P.; M. Mohamed Essa

    2007-01-01

    Hibiscus sabdariffa (HS) is an edible medicinal plant, indigenous to India, China and Thailand and is used in Ayurveda and traditional medicine. Alcoholic extract of HS leaves (HSEt) was studied for its anti-hyperammonemic and antioxidant effects in brain tissues of ammonium chloride-induced hyperammonemic rats. Oral administration of HSEt (250 mg kg−1 body weight) significantly normalizes the levels of ammonia, urea, uric acid, creatinine and non-protein nitrogen in the blood. HSEt significa...

  18. Intergranular Corrosion of 2024 Alloy in Chloride Solutions

    OpenAIRE

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

    2007-01-01

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

  19. A spontaneous, tonic chloride conductance in solitary glutamatergic hippocampal neurons

    OpenAIRE

    Eisenman, Lawrence N.; Kress, Geraldine; Charles F. Zorumski; Mennerick, Steven

    2006-01-01

    GABA-A receptors mediate both phasic synaptic inhibition and more recently appreciated tonic currents in the vertebrate central nervous system. We addressed discrepancies in the literature regarding the pharmacology of tonic currents by examining tonic currents in a controlled environment of dissociated, solitary glutamatergic neurons. We describe a novel tonically active, bicuculline-sensitive chloride conductance that is insensitive to gabazine and to picrotoxin and thus not mediated by con...

  20. Binary Nucleation in Aqueous Electrolyte Systems. Sodium Chloride

    Czech Academy of Sciences Publication Activity Database

    Němec, Tomáš; Maršík, František

    Gdansk: IFFM Publishers, 2005 - (Mikielewicz, J.; Butrymowicz, D.; Trela, M.; Cieslinski, J.), s. 395-400 ISBN 83-88237-90-X. [HEAT 2005 : International Conference on Transport Phenomena in Multiphase Systems. Gdansk (PL), 26.06.2005-30.06.2005] R&D Projects: GA ČR(CZ) GA101/05/2536 Institutional research plan: CEZ:AV0Z20760514 Keywords : binary nucleation * sodium chloride * water Subject RIV: BJ - Thermodynamics