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Sample records for isothermal plug flow

  1. Lunar ash flows - Isothermal approximation.

    Science.gov (United States)

    Pai, S. I.; Hsieh, T.; O'Keefe, J. A.

    1972-01-01

    Suggestion of the ash flow mechanism as one of the major processes required to account for some features of lunar soil. First the observational background and the gardening hypothesis are reviewed, and the shortcomings of the gardening hypothesis are shown. Then a general description of the lunar ash flow is given, and a simple mathematical model of the isothermal lunar ash flow is worked out with numerical examples to show the differences between the lunar and the terrestrial ash flow. The important parameters of the ash flow process are isolated and analyzed. It appears that the lunar surface layer in the maria is not a residual mantle rock (regolith) but a series of ash flows due, at least in part, to great meteorite impacts. The possibility of a volcanic contribution is not excluded. Some further analytic research on lunar ash flows is recommended.

  2. Flow induced vibration studies on PFBR control plug components

    Energy Technology Data Exchange (ETDEWEB)

    Prakash, V., E-mail: prakash@igcar.gov.in [Fast Reactor Technology Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamilnadu (India); Kumar, P. Anup; Anandaraj, M.; Thirumalai, M.; Anandbabu, C.; Rajan, K.K. [Fast Reactor Technology Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamilnadu (India)

    2012-09-15

    Highlights: Black-Right-Pointing-Pointer Flow induced vibration studies on Prototype Fast Breeder Reactor control plug model carried out. Black-Right-Pointing-Pointer Velocity similitude was followed for the study. Black-Right-Pointing-Pointer Frequencies and amplitude of vibrations of various control plug components measured. Black-Right-Pointing-Pointer Overall values of vibration are well within permissible limits. - Abstract: The construction of Prototype Fast Breeder Reactor (PFBR), a 500 MWe liquid sodium cooled reactor, is in progress at Kalpakkam in India. Control plug (CP) is located right above the core subassemblies in the hot pool. Control plug is an important component as many of the critical reactor parameters are sensed and controlled by the components housed in the control plug assembly. In PFBR primary circuit, components are basically thin walled, slender shells with diameter to thickness ratio ranging from 100 to 650. These components are prone to flow induced vibrations. The existence of free liquid (sodium) surfaces, which is the source of sloshing phenomenon and the operation of primary sodium pump in the primary pool are other potential sources of vibration of reactor components. Control plug is a hollow cylindrical shell structure and provides passages and support for 12 absorber rod drive mechanisms (ARDM) which consists of 9 control and safety rods and 3 diverse safety rods, 210 thermo wells to measure the sodium temperature at the exit of various fuel subassemblies, three failed fuel localization modules (FFLM) and acoustic detectors. It consists of a core cover plate (CCP), which forms the bottom end, two intermediate supports plate, i.e. lower stay plate (LSP) and upper stay plate (USP) and an outer shell. The CCP is located at a distance of 1.3 m from the core top. With such a gap, there will be long free hanging length of the thermocouple sleeves, Delayed neutron detector (DND) sampling tubes and ARDM shroud tubes and hence they are

  3. Self-similar drag reduction in plug-flow of suspensions of macroscopic fibers

    NARCIS (Netherlands)

    Gillissen, J.J.J.; Hoving, J.P.

    2012-01-01

    Pipe flow experiments show that turbulent drag reduction in plug-flow of concentrated suspensions of macroscopic fibers is a self-similar function of the wall shear stress over the fiber network yield stress. We model the experimental observations, by assuming a central fiber network plug, whose

  4. Mass flow and velocity profiles in Neurospora hyphae: partial plug flow dominates intra-hyphal transport.

    Science.gov (United States)

    Abadeh, Aryan; Lew, Roger R

    2013-11-01

    Movement of nuclei, mitochondria and vacuoles through hyphal trunks of Neurospora crassa were vector-mapped using fluorescent markers and green fluorescent protein tags. The vectorial movements of all three were strongly correlated, indicating the central role of mass (bulk) flow in cytoplasm movements in N. crassa. Profiles of velocity versus distance from the hyphal wall did not match the parabolic shape predicted by the ideal Hagen-Poiseuille model of flow at low Reynolds number. Instead, the profiles were flat, consistent with a model of partial plug flow due to the high concentration of organelles in the flowing cytosol. The intra-hyphal pressure gradients were manipulated by localized external osmotic treatments to demonstrate the dependence of velocity (and direction) on pressure gradients within the hyphae. The data support the concept that mass transport, driven by pressure gradients, dominates intra-hyphal transport. The transport occurs by partial plug flow due to the organelles in the cytosol.

  5. Plugging of drinking water flow into horizontal high diameter pipeline with artificial ice plug

    International Nuclear Information System (INIS)

    Gyongyosi, T.; Valeca, S.; Panaitescu, V. N.; Prisecaru, I.

    2013-01-01

    Local isolation of a pipeline section, placed horizontally into a loop of drinking water supply network, can be made with an ice plug resulting after controlled process inside of pipeline without stopping the consumer supply. The technique is applying in order to perform repairs or items replacement, without closing the drinking water supply network at the same time decreasing the fluid loss resulted after discharge of the affected loop. In facts, the technique is simple one and assumes to apply a special device sized for each case using a freezing liquid agent injected continuously. The paper contains a constructive description of the experimental technological facilities and of the experimental model for ice plugging device used. The test, the first results get and some conclusion are following. The paper is dedicated to the specialists working in the research and technological engineering. (authors)

  6. Transition from annular flow to plug/slug flow in condensation of steam in microchannels

    Energy Technology Data Exchange (ETDEWEB)

    Quan, Xiaojun; Cheng, Ping; Wu, Huiying [School of Mechanical and Power Engineering, Shanghai Jiaotong University, 800 Dong Chuan Road, Shanghai 200240 (China)

    2008-02-15

    A visualization study has been conducted to investigate the transition from annular flow to plug/slug flow in the condensation of steam in two different sets of parallel microchannels, having hydraulic diameters of 90 {mu}m and 136 {mu}m, respectively. The steam in the parallel microchannels was cooled on the bottom by forced convection of water and by natural convection of air from the top. It is found that the location, where the transition from annular flow to plug/slug flow takes place, depends on mass flux and cooling rate of steam. The effects of mass flux and cooling rate on the occurrence frequency of the injection flow in a single microchannel, having a hydraulic diameter of 120 {mu}m and 128 {mu}m, respectively, are investigated. It is found that two different shapes of injection flow occur in the smooth annular flow in microchannels: injection flow with unsteady vapor ligament occurring at low mass flux (or high cooling rate) and injection flow with steady vapor ligament occurring at high mass flux (or low cooling rate). It is also found that increase of steam mass flux, decrease of cooling rate, or decrease of the microchannel diameter tends to enhance instability of the condensate film on the wall, resulting in occurrence of the injection flow further toward the outlet with an increase in occurrence frequency. (author)

  7. Thermistor based, low velocity isothermal, air flow sensor

    International Nuclear Information System (INIS)

    Cabrita, Admésio A C M; Mendes, Ricardo; Quintela, Divo A

    2016-01-01

    The semiconductor thermistor technology is applied as a flow sensor to measure low isothermal air velocities (<2 ms −1 ). The sensor is subjected to heating and cooling cycles controlled by a multifunctional timer. In the heating stage, the alternating current of a main AC power supply source guarantees a uniform thermistor temperature distribution. The conditioning circuit assures an adequate increase of the sensors temperature and avoids the thermal disturbance of the flow. The power supply interruption reduces the consumption from the source and extends the sensors life time. In the cooling stage, the resistance variation of the flow sensor is recorded by the measuring chain. The resistive sensor parameters proposed vary significantly and feature a high sensitivity to the flow velocity. With the aid of a computer, the data transfer, storage and analysis provides a great advantage over the traditional local anemometer readings. The data acquisition chain has a good repeatability and low standard uncertainties. The proposed method measures isothermal air mean velocities from 0.1 ms −1 to 2 ms −1 with a standard uncertainty error less than 4%. (paper)

  8. Simulation of non-isothermal transient flow in gas pipeline

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira Junior, Luis Carlos; Soares, Matheus; Lima, Enrique Luis; Pinto, Jose Carlos [Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Quimica; Muniz, Cyro; Pires, Clarissa Cortes; Rochocz, Geraldo [ChemTech, Rio de Janeiro, RJ (Brazil)

    2009-07-01

    Modeling of gas pipeline usually considers that the gas flow is isothermal (or adiabatic) and that pressure changes occur instantaneously (quasi steady state approach). However, these assumptions are not valid in many important transient applications (changes of inlet and outlet flows/pressures, starting and stopping of compressors, changes of controller set points, among others). Besides, the gas properties are likely to depend simultaneously on the pipe position and on the operation time. For this reason, a mathematical model is presented and implemented in this paper in order to describe the gas flow in pipeline when pressure and temperature transients cannot be neglected. The model is used afterwards as a tool for reconciliation of available measured data. (author)

  9. A plug flow reactor model of a vanadium redox flow battery considering the conductive current collectors

    Science.gov (United States)

    König, S.; Suriyah, M. R.; Leibfried, T.

    2017-08-01

    A lumped-parameter model for vanadium redox flow batteries, which use metallic current collectors, is extended into a one-dimensional model using the plug flow reactor principle. Thus, the commonly used simplification of a perfectly mixed cell is no longer required. The resistances of the cell components are derived in the in-plane and through-plane directions. The copper current collector is the only component with a significant in-plane conductance, which allows for a simplified electrical network. The division of a full-scale flow cell into 10 layers in the direction of fluid flow represents a reasonable compromise between computational effort and accuracy. Due to the variations in the state of charge and thus the open circuit voltage of the electrolyte, the currents in the individual layers vary considerably. Hence, there are situations, in which the first layer, directly at the electrolyte input, carries a multiple of the last layer's current. The conventional model overestimates the cell performance. In the worst-case scenario, the more accurate 20-layer model yields a discharge capacity 9.4% smaller than that computed with the conventional model. The conductive current collector effectively eliminates the high over-potentials in the last layers of the plug flow reactor models that have been reported previously.

  10. Extended forward sensitivity analysis of one-dimensional isothermal flow

    International Nuclear Information System (INIS)

    Johnson, M.; Zhao, H.

    2013-01-01

    Sensitivity analysis and uncertainty quantification is an important part of nuclear safety analysis. In this work, forward sensitivity analysis is used to compute solution sensitivities on 1-D fluid flow equations typical of those found in system level codes. Time step sensitivity analysis is included as a method for determining the accumulated error from time discretization. The ability to quantify numerical error arising from the time discretization is a unique and important feature of this method. By knowing the relative sensitivity of time step with other physical parameters, the simulation is allowed to run at optimized time steps without affecting the confidence of the physical parameter sensitivity results. The time step forward sensitivity analysis method can also replace the traditional time step convergence studies that are a key part of code verification with much less computational cost. One well-defined benchmark problem with manufactured solutions is utilized to verify the method; another test isothermal flow problem is used to demonstrate the extended forward sensitivity analysis process. Through these sample problems, the paper shows the feasibility and potential of using the forward sensitivity analysis method to quantify uncertainty in input parameters and time step size for a 1-D system-level thermal-hydraulic safety code. (authors)

  11. Isothermal and Reactive Turbulent Jets in Cross-Flow

    Science.gov (United States)

    Gutmark, Ephraim; Bush, Scott; Ibrahim, Irene

    2004-11-01

    Jets in cross flow have numerous applications including vertical/short takeoff/landing (V/STOL) aircraft, cooling jets for gas turbine blades and combustion air supply inlets in gas turbine engine. The properties exhibited by these jets are dictated by complex three dimensional turbulence structures which form due to the interaction of the jet with the freestream. The isothermal tests are conducted in a wind tunnel measuring the characteristics of air jets injected perpendicular into an otherwise undisturbed air stream. Different nozzle exit geometries of the air jets were tested including circular, triangular and elongated configurations. Jets are injected in single and paired combinations with other jets to measure the effect of mutual interaction on the parameters mentioned. Quantitative velocity fields are obtained using PIV. The data obtained allows the extraction of flow parameters such as jet structure, penetration and mixing. The reacting tests include separate and combined jets of fuel/air mixture utilized to explore the stabilization of combustion at various operating conditions. Different geometrical configurations of transverse jets are tested to determine the shape and combination of jets that will optimize the jets ability to successfully stabilize a flame.

  12. Multiple stable isotope fronts during non-isothermal fluid flow

    Science.gov (United States)

    Fekete, Szandra; Weis, Philipp; Scott, Samuel; Driesner, Thomas

    2018-02-01

    Stable isotope signatures of oxygen, hydrogen and other elements in minerals from hydrothermal veins and metasomatized host rocks are widely used to investigate fluid sources and paths. Previous theoretical studies mostly focused on analyzing stable isotope fronts developing during single-phase, isothermal fluid flow. In this study, numerical simulations were performed to assess how temperature changes, transport phenomena, kinetic vs. equilibrium isotope exchange, and isotopic source signals determine mineral oxygen isotopic compositions during fluid-rock interaction. The simulations focus on one-dimensional scenarios, with non-isothermal single- and two-phase fluid flow, and include the effects of quartz precipitation and dissolution. If isotope exchange between fluid and mineral is fast, a previously unrecognized, significant enrichment in heavy oxygen isotopes of fluids and minerals occurs at the thermal front. The maximum enrichment depends on the initial isotopic composition of fluid and mineral, the fluid-rock ratio and the maximum change in temperature, but is independent of the isotopic composition of the incoming fluid. This thermally induced isotope front propagates faster than the signal related to the initial isotopic composition of the incoming fluid, which forms a trailing front behind the zone of transient heavy oxygen isotope enrichment. Temperature-dependent kinetic rates of isotope exchange between fluid and rock strongly influence the degree of enrichment at the thermal front. In systems where initial isotope values of fluids and rocks are far from equilibrium and isotope fractionation is controlled by kinetics, the temperature increase accelerates the approach of the fluid to equilibrium conditions with the host rock. Consequently, the increase at the thermal front can be less dominant and can even generate fluid values below the initial isotopic composition of the input fluid. As kinetics limit the degree of isotope exchange, a third front may

  13. Dispersed plug flow model for upflow anaerobic sludge bed reactors with focus on granular sludge dynamics

    NARCIS (Netherlands)

    Kalyuzhnyi, S.V.; Fedorovich, V.V.; Lens, P.N.L.

    2006-01-01

    A new approach to model upflow anaerobic sludge bed (UASB)-reactors, referred to as a one-dimensional dispersed plug flow model, was developed. This model focusses on the granular sludge dynamics along the reactor height, based on the balance between dispersion, sedimentation and convection using

  14. Tube plug

    International Nuclear Information System (INIS)

    Zafred, P. R.

    1985-01-01

    The tube plug comprises a one piece mechanical plug having one open end and one closed end which is capable of being inserted in a heat exchange tube and internally expanded into contact with the inside surface of the heat exchange tube for preventing flow of a coolant through the heat exchange tube. The tube plug also comprises a groove extending around the outside circumference thereof which has an elastomeric material disposed in the groove for enhancing the seal between the tube plug and the tube

  15. Effect of shear-thinning behaviour on liquid-liquid plug flow in microchannels

    Science.gov (United States)

    Roumpea, Evangelia; Chinaud, Maxime; Weheliye, Weheliye Hashi; Angeli, Panagiota; Kahouadji, Lyes; Matar, Omar K.

    2016-11-01

    The present work investigates the dynamics of plug formation of shear-thinning solutions in a 200 μm microchannel using a two-colour micro-PIV system. Measurements, including phase-averaged velocity fields, have been conducted both at the T-junction inlet and the main channel to enhance understanding of non-Newtonian liquid-liquid flows. Two aqueous glycerol solutions containing xanthan gum are used as the non-Newtonian fluids while 5 cSt silicone oil is the Newtonian phase. The current experimental results revealed a pronounced impact of the xanthan gum (shear-thinning behaviour) on the flow pattern transition boundaries, and enhance the fluid flowrates where plug flow occurred. The addition of polymer resulted also in different hydrodynamic characteristics such as a bullet-shaped plug and an increased film thickness between the plug and the wall. In the present work, the technique allows to capture the velocity field of both phases simultaneously. Experimental results are compared with the numerical simulations provided by the code BLUE. Project funded under the UK Engineering and Physical Sciences Research Council (EPSRC) Programme Grant MEMPHIS.

  16. Negative Saturation Approach for Non-Isothermal Compositional Two-Phase Flow Simulations

    NARCIS (Netherlands)

    Salimi, H.; Wolf, K.H.; Bruining, J.

    2011-01-01

    This article deals with developing a solution approach, called the non-isothermal negative saturation (NegSat) solution approach. The NegSat solution approach solves efficiently any non-isothermal compositional flow problem that involves phase disappearance, phase appearance, and phase transition.

  17. Comparative study of incompressible and isothermal compressible flow solvers for cavitating flow dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sun Ho [Korea Maritime and Ocean University, Busan (Korea, Republic of); Rhee, Shin Hyung [Seoul National University, Seoul (Korea, Republic of)

    2015-08-15

    Incompressible flow solvers are generally used for numerical analysis of cavitating flows, but with limitations in handling compressibility effects on vapor phase. To study compressibility effects on vapor phase and cavity interface, pressure-based incompressible and isothermal compressible flow solvers based on a cell-centered finite volume method were developed using the OpenFOAM libraries. To validate the solvers, cavitating flow around a hemispherical head-form body was simulated and validated against the experimental data. The cavity shedding behavior, length of a re-entrant jet, drag history, and the Strouhal number were compared between the two solvers. The results confirmed that computations of the cavitating flow including compressibility effects improved the reproduction of cavitation dynamics.

  18. The sound field of a rotating dipole in a plug flow.

    Science.gov (United States)

    Wang, Zhao-Huan; Belyaev, Ivan V; Zhang, Xiao-Zheng; Bi, Chuan-Xing; Faranosov, Georgy A; Dowell, Earl H

    2018-04-01

    An analytical far field solution for a rotating point dipole source in a plug flow is derived. The shear layer of the jet is modelled as an infinitely thin cylindrical vortex sheet and the far field integral is calculated by the stationary phase method. Four numerical tests are performed to validate the derived solution as well as to assess the effects of sound refraction from the shear layer. First, the calculated results using the derived formulations are compared with the known solution for a rotating dipole in a uniform flow to validate the present model in this fundamental test case. After that, the effects of sound refraction for different rotating dipole sources in the plug flow are assessed. Then the refraction effects on different frequency components of the signal at the observer position, as well as the effects of the motion of the source and of the type of source are considered. Finally, the effect of different sound speeds and densities outside and inside the plug flow is investigated. The solution obtained may be of particular interest for propeller and rotor noise measurements in open jet anechoic wind tunnels.

  19. Simulation and scaling for natural convection flow in a cavity with isothermal boundaries

    International Nuclear Information System (INIS)

    Jiracheewanun, S.; Armfield, S.W.; McBain, G.D.; Behnia, M.

    2005-01-01

    A numerical study of the transient two-dimensional natural convection flow within a differentially heated square cavity with iso-flux side walls and adiabatic top and bottom boundaries is presented. The governing equations are discretized using a non-staggered mesh and solved using a non-iterative fractional-step pressure correction method which provides second-order accuracy in both time and space. Results are obtained with the iso-flux boundary condition for Ra = 5.8 x 10 9 and Pr = 7.5. The results show that the transient flow features obtained for the iso-flux cavity are similar to the flow features for the isothermal case. However, the fully developed flow features of the iso-flux cavity are very different from the isothermal case. The scalings for the fully developed iso-flux boundary condition flow have been found to be different to those of the isothermal boundary condition flow. (authors)

  20. Computation of two-dimensional isothermal flow in shell-and-tube heat exchangers

    International Nuclear Information System (INIS)

    Carlucci, L.N.; Galpin, P.F.; Brown, J.D.; Frisina, V.

    1983-07-01

    A computational procedure is outlined whereby two-dimensional isothermal shell-side flow distributions can be calculated for tube bundles having arbitrary boundaries and flow blocking devices, such as sealing strips, defined in arbitrary locations. The procedure is described in some detail and several computed results are presented to illustrate the robustness and generality of the method

  1. Solution of weakly compressible isothermal flow in landfill gas collection networks

    Energy Technology Data Exchange (ETDEWEB)

    Nec, Y [Thompson Rivers University, Kamloops, British Columbia (Canada); Huculak, G, E-mail: cranberryana@gmail.com, E-mail: greg@gnhconsulting.ca [GNH Consulting, Delta, British Columbia (Canada)

    2017-12-15

    Pipe networks collecting gas in sanitary landfills operate under the regime of a weakly compressible isothermal flow of ideal gas. The effect of compressibility has been traditionally neglected in this application in favour of simplicity, thereby creating a conceptual incongruity between the flow equations and thermodynamic equation of state. Here the flow is solved by generalisation of the classic Darcy–Weisbach equation for an incompressible steady flow in a pipe to an ordinary differential equation, permitting continuous variation of density, viscosity and related fluid parameters, as well as head loss or gain due to gravity, in isothermal flow. The differential equation is solved analytically in the case of ideal gas for a single edge in the network. Thereafter the solution is used in an algorithm developed to construct the flow equations automatically for a network characterised by an incidence matrix, and determine pressure distribution, flow rates and all associated parameters therein. (paper)

  2. Solution of weakly compressible isothermal flow in landfill gas collection networks

    Science.gov (United States)

    Nec, Y.; Huculak, G.

    2017-12-01

    Pipe networks collecting gas in sanitary landfills operate under the regime of a weakly compressible isothermal flow of ideal gas. The effect of compressibility has been traditionally neglected in this application in favour of simplicity, thereby creating a conceptual incongruity between the flow equations and thermodynamic equation of state. Here the flow is solved by generalisation of the classic Darcy-Weisbach equation for an incompressible steady flow in a pipe to an ordinary differential equation, permitting continuous variation of density, viscosity and related fluid parameters, as well as head loss or gain due to gravity, in isothermal flow. The differential equation is solved analytically in the case of ideal gas for a single edge in the network. Thereafter the solution is used in an algorithm developed to construct the flow equations automatically for a network characterised by an incidence matrix, and determine pressure distribution, flow rates and all associated parameters therein.

  3. Solution of weakly compressible isothermal flow in landfill gas collection networks

    International Nuclear Information System (INIS)

    Nec, Y; Huculak, G

    2017-01-01

    Pipe networks collecting gas in sanitary landfills operate under the regime of a weakly compressible isothermal flow of ideal gas. The effect of compressibility has been traditionally neglected in this application in favour of simplicity, thereby creating a conceptual incongruity between the flow equations and thermodynamic equation of state. Here the flow is solved by generalisation of the classic Darcy–Weisbach equation for an incompressible steady flow in a pipe to an ordinary differential equation, permitting continuous variation of density, viscosity and related fluid parameters, as well as head loss or gain due to gravity, in isothermal flow. The differential equation is solved analytically in the case of ideal gas for a single edge in the network. Thereafter the solution is used in an algorithm developed to construct the flow equations automatically for a network characterised by an incidence matrix, and determine pressure distribution, flow rates and all associated parameters therein. (paper)

  4. A high-pressure plug flow reactor for combustion chemistry investigations

    International Nuclear Information System (INIS)

    Lu, Zhewen; Cochet, Julien; Leplat, Nicolas; Yang, Yi; Brear, Michael J

    2017-01-01

    A plug flow reactor (PFR) is built for investigating the oxidation chemistry of fuels at up to 50 bar and 1000 K. These conditions include those corresponding to the low temperature combustion (i.e. the autoignition) that commonly occurs in internal combustion engines. Turbulent flow that approximates ideal, plug flow conditions is established in a quartz tube reactor. The reacting mixture is highly diluted by excess air to reduce the reaction rates for kinetic investigations. A novel mixer design is used to achieve fast mixing of the preheated air and fuel vapour at the reactor entrance, reducing the issue of reaction initialization in kinetic modelling. A water-cooled probe moves along the reactor extracting gases for further analysis. Measurement of the sampled gas temperature uses an extended form of a three-thermocouple method that corrects for radiative heat losses from the thermocouples to the enclosed PFR environment. Investigation of the PFR’s operation is first conducted using non-reacting flows, and then with isooctane oxidation at 900 K and 10 bar. Mixing of the non-reacting temperature and species fields is shown to be rapid. The measured fuel consumption and CO formation are then closely reproduced by kinetic modelling using an extensively validated iso-octane mechanism from the literature and the corrected gas temperature. Together, these results demonstrate the PFR’s utility for chemical kinetic investigations. (paper)

  5. A high-pressure plug flow reactor for combustion chemistry investigations

    Science.gov (United States)

    Lu, Zhewen; Cochet, Julien; Leplat, Nicolas; Yang, Yi; Brear, Michael J.

    2017-10-01

    A plug flow reactor (PFR) is built for investigating the oxidation chemistry of fuels at up to 50 bar and 1000 K. These conditions include those corresponding to the low temperature combustion (i.e. the autoignition) that commonly occurs in internal combustion engines. Turbulent flow that approximates ideal, plug flow conditions is established in a quartz tube reactor. The reacting mixture is highly diluted by excess air to reduce the reaction rates for kinetic investigations. A novel mixer design is used to achieve fast mixing of the preheated air and fuel vapour at the reactor entrance, reducing the issue of reaction initialization in kinetic modelling. A water-cooled probe moves along the reactor extracting gases for further analysis. Measurement of the sampled gas temperature uses an extended form of a three-thermocouple method that corrects for radiative heat losses from the thermocouples to the enclosed PFR environment. Investigation of the PFR’s operation is first conducted using non-reacting flows, and then with isooctane oxidation at 900 K and 10 bar. Mixing of the non-reacting temperature and species fields is shown to be rapid. The measured fuel consumption and CO formation are then closely reproduced by kinetic modelling using an extensively validated iso-octane mechanism from the literature and the corrected gas temperature. Together, these results demonstrate the PFR’s utility for chemical kinetic investigations.

  6. Maximum production rate optimization for sulphuric acid decomposition process in tubular plug-flow reactor

    International Nuclear Information System (INIS)

    Wang, Chao; Chen, Lingen; Xia, Shaojun; Sun, Fengrui

    2016-01-01

    A sulphuric acid decomposition process in a tubular plug-flow reactor with fixed inlet flow rate and completely controllable exterior wall temperature profile and reactants pressure profile is studied in this paper by using finite-time thermodynamics. The maximum production rate of the aimed product SO 2 and the optimal exterior wall temperature profile and reactants pressure profile are obtained by using nonlinear programming method. Then the optimal reactor with the maximum production rate is compared with the reference reactor with linear exterior wall temperature profile and the optimal reactor with minimum entropy generation rate. The result shows that the production rate of SO 2 of optimal reactor with the maximum production rate has an increase of more than 7%. The optimization of temperature profile has little influence on the production rate while the optimization of reactants pressure profile can significantly increase the production rate. The results obtained may provide some guidelines for the design of real tubular reactors. - Highlights: • Sulphuric acid decomposition process in tubular plug-flow reactor is studied. • Fixed inlet flow rate and controllable temperature and pressure profiles are set. • Maximum production rate of aimed product SO 2 is obtained. • Corresponding optimal temperature and pressure profiles are derived. • Production rate of SO 2 of optimal reactor increases by 7%.

  7. Non-isothermal effects on multi-phase flow in porous medium

    DEFF Research Database (Denmark)

    Singh, Ashok; Wang, W; Park, C. H.

    2010-01-01

    In this paper a ppT -formulation for non-isothermal multi-phase flow is given including diffusion and latent heat effects. Temperature and pressure dependencies of governing parameters are considered, in particular surface tension variation on phase interfaces along with temperature changes. A we...

  8. Computational Fluid Dynamics simulation of hydrothermal liquefaction of microalgae in a continuous plug-flow reactor.

    Science.gov (United States)

    Ranganathan, Panneerselvam; Savithri, Sivaraman

    2018-06-01

    Computational Fluid Dynamics (CFD) technique is used in this work to simulate the hydrothermal liquefaction of Nannochloropsis sp. microalgae in a lab-scale continuous plug-flow reactor to understand the fluid dynamics, heat transfer, and reaction kinetics in a HTL reactor under hydrothermal condition. The temperature profile in the reactor and the yield of HTL products from the present simulation are obtained and they are validated with the experimental data available in the literature. Furthermore, the parametric study is carried out to study the effect of slurry flow rate, reactor temperature, and external heat transfer coefficient on the yield of products. Though the model predictions are satisfactory in comparison with the experimental results, it still needs to be improved for better prediction of the product yields. This improved model will be considered as a baseline for design and scale-up of large-scale HTL reactor. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. A comparison of three turbulence models for axisymmetric isothermal swirling flows in the near burner zone

    Energy Technology Data Exchange (ETDEWEB)

    Ahlstedt, H [Tampere Univ. of Technology (Finland). Energy and Process Engineering

    1998-12-31

    In this work three different turbulence models, the k - {epsilon}, RNG k - {epsilon} and Reynolds stress model, have been compared in the case of confined swirling flow. The flow geometries are the isothermal swirling flows measured by International Flame Research Foundation (IFRF). The inlet boundary profiles have been taken from the measurements. At the outlet the effect of furnace end contraction has been studied. The k - {epsilon} model falls to predict the correct flow field. The RNG k - {epsilon} model can provide improvements, although it has problems near the symmetry axis. The Reynolds stress model produces the best agreement with measured data. (author) 13 refs.

  10. A comparison of three turbulence models for axisymmetric isothermal swirling flows in the near burner zone

    Energy Technology Data Exchange (ETDEWEB)

    Ahlstedt, H. [Tampere Univ. of Technology (Finland). Energy and Process Engineering

    1997-12-31

    In this work three different turbulence models, the k - {epsilon}, RNG k - {epsilon} and Reynolds stress model, have been compared in the case of confined swirling flow. The flow geometries are the isothermal swirling flows measured by International Flame Research Foundation (IFRF). The inlet boundary profiles have been taken from the measurements. At the outlet the effect of furnace end contraction has been studied. The k - {epsilon} model falls to predict the correct flow field. The RNG k - {epsilon} model can provide improvements, although it has problems near the symmetry axis. The Reynolds stress model produces the best agreement with measured data. (author) 13 refs.

  11. Use of anaerobic plug flow biodigesters in Cuba's Guaniguanico Mountains

    Energy Technology Data Exchange (ETDEWEB)

    Sosa, R.; Chao, R.; Perez, A.; Cairo, G.; Garcia, A.; Macias, M. [Swine Research Inst., Habana (Cuba). Dept. of Environmental Protection

    2004-07-01

    This study presented a solution to an environmental pollution problem facing pig farms in Cuba. A new variant of anaerobic plug flow biodigester for producing methane from organic waste was described. The stable biodigester has a width/length relationship of 1:8.8 and is suitable for all animal wastes, including pig manure. Chemical analysis were performed in the digester effluents. Wastewaters from the biodigester were analyzed for total solids, total volatile solids, ashes, total nitrogen, phosphorous and potassium. Reduction in organic matter in terms of total solids and total volatile solids was 65 per cent and 68 per cent respectively. The waste material was rendered useful as an organic fertilizer due to its high content of ash, nitrogen, phosphorous and potassium. The quality of the biogas was acceptable with no stench. The methane proportion was higher than 50 per cent. The amount of biogas produced was sufficient for cooking purposes. 9 refs., 2 tabs., 1 fig.

  12. Isothermal Amplification and Lateral-Flow Assay for Detecting Crown-Gall-Causing Agrobacterium spp.

    Science.gov (United States)

    Fuller, Skylar L; Savory, Elizabeth A; Weisberg, Alexandra J; Buser, Jessica Z; Gordon, Michael I; Putnam, Melodie L; Chang, Jeff H

    2017-09-01

    Agrobacterium is a genus of soilborne gram-negative bacteria. Members carrying oncogenic plasmids can cause crown gall disease, which has significant economic costs, especially for the orchard and nursery industries. Early and rapid detection of pathogenic Agrobacterium spp. is key to the management of crown gall disease. To this end, we designed oligonucleotide primers and probes to target virD2 for use in a molecular diagnostic tool that relies on isothermal amplification and lateral-flow-based detection. The oligonucleotide tools were tested in the assay and evaluated for detection limit and specificity in detecting alleles of virD2. One set of primers that successfully amplified virD2 when used with an isothermal recombinase was selected. Both tested probes had detection limits in picogram amounts of DNA. Probe 1 could detect all tested pathogenic isolates that represented most of the diversity of virD2. Finally, the coupling of lateral-flow detection to the use of these oligonucleotide primers in isothermal amplification helped to reduce the onerousness of the process, and alleviated reliance on specialized tools necessary for molecular diagnostics. The assay is an advancement for the rapid molecular detection of pathogenic Agrobacterium spp.

  13. Drill pipe bridge plug

    International Nuclear Information System (INIS)

    Winslow, D.W.; Brisco, D.P.

    1991-01-01

    This patent describes a method of stopping flow of fluid up through a pipe bore of a pipe string in a well. It comprises: lowering a bridge plug apparatus on a work string into the pipe string to a position where the pipe bore is to be closed; communicating the pipe bore below a packer of the bridge plug apparatus through the bridge plug apparatus with a low pressure zone above the packer to permit the fluid to flow up through the bridge plug apparatus; engaging the bridge plug apparatus with an internal upset of the pipe string; while the fluid is flowing up through the bridge plug apparatus, pulling upward on the work string and the bridge plug apparatus and thereby sealing the packer against the pipe bore; isolating the pipe bore below the packer from the low pressure zone above the packer and thereby stopping flow of the fluid up through the pipe bore; disconnecting the work string from the bridge plug apparatus; and maintaining the bridge plug apparatus in engagement with the internal upset and sealed against the pipe bore due to an upward pressure differential applied to the bridge plug apparatus by the fluid contained therebelow

  14. Use of the Amplatzer Type 2 Plug for Flow Redirection in Failing Autogenous Hemodialysis Fistulae

    International Nuclear Information System (INIS)

    Bozkurt, Alper; Kırbaş, İsmail; Kasapoglu, Benan; Teber, Mehmet Akif

    2015-01-01

    PurposeTo present our experience with redirecting the outflow of mature arteriovenous fistulae (AVFs) in patients with cannulation and/or suboptimal flow problems by percutaneous intervention using the Amplatzer Vascular Plug II (AVP II).MethodsWe retrospectively reviewed patients who presented with difficulty in cannulation and/or suboptimal flow in the puncture zone of the AVF and who underwent intervention using the AVP II to redirect the outflow through a better cannulation zone from March 2009 to November 2012. The mean survival rate of all AVFs was estimated, and the effects of patient age, sex, and AVF age on the AVF survival time were determined.ResultsIn total, 31 patients (17 male and 14 female) with a mean age of 57.8 years (range, 20–79 years) were included. In 2 patients, the AVF failed within the first 15 days because of rapid thrombosis. In 9 patients, the new AVF route was working effectively until unsalvageable thrombosis developed. One of the 31 patients died 9 months before the last radiologic evaluation. The new AVF route was still being used for dialysis in the remaining 19 patients. The mean AVF survival rate was 1,061.4 ± 139.4 days (range, 788–1,334 days). Patient age, sex, and AVF age did not affect the survival time.ConclusionWe suggest that the AVP II is useful for redirecting the outflow of AVFs with cannulation problems and suboptimal flow. Patency of existing AVFs may be extended, thereby extending surgery-free or catheter intervention-free survival period

  15. Use of the Amplatzer Type 2 Plug for Flow Redirection in Failing Autogenous Hemodialysis Fistulae

    Energy Technology Data Exchange (ETDEWEB)

    Bozkurt, Alper, E-mail: bozkurtalper@yahoo.com; Kırbaş, İsmail, E-mail: drismailk@yahoo.com [Turgut Ozal University Hospital, Radiology Department (Turkey); Kasapoglu, Benan, E-mail: benankasapoglu@hotmail.com [Turgut Ozal University Hospital, Internal Medicine Department (Turkey); Teber, Mehmet Akif, E-mail: drteberma@hotmail.com [Ataturk Education and Training Hospital, Radiology Department (Turkey)

    2015-08-15

    PurposeTo present our experience with redirecting the outflow of mature arteriovenous fistulae (AVFs) in patients with cannulation and/or suboptimal flow problems by percutaneous intervention using the Amplatzer Vascular Plug II (AVP II).MethodsWe retrospectively reviewed patients who presented with difficulty in cannulation and/or suboptimal flow in the puncture zone of the AVF and who underwent intervention using the AVP II to redirect the outflow through a better cannulation zone from March 2009 to November 2012. The mean survival rate of all AVFs was estimated, and the effects of patient age, sex, and AVF age on the AVF survival time were determined.ResultsIn total, 31 patients (17 male and 14 female) with a mean age of 57.8 years (range, 20–79 years) were included. In 2 patients, the AVF failed within the first 15 days because of rapid thrombosis. In 9 patients, the new AVF route was working effectively until unsalvageable thrombosis developed. One of the 31 patients died 9 months before the last radiologic evaluation. The new AVF route was still being used for dialysis in the remaining 19 patients. The mean AVF survival rate was 1,061.4 ± 139.4 days (range, 788–1,334 days). Patient age, sex, and AVF age did not affect the survival time.ConclusionWe suggest that the AVP II is useful for redirecting the outflow of AVFs with cannulation problems and suboptimal flow. Patency of existing AVFs may be extended, thereby extending surgery-free or catheter intervention-free survival period.

  16. Wall modeling for the simulation of highly non-isothermal unsteady flows

    International Nuclear Information System (INIS)

    Devesa, A.

    2006-12-01

    Nuclear industry flows are most of the time characterized by their high Reynolds number, density variations (at low Mach numbers) and a highly unsteady behaviour (low to moderate frequencies). High Reynolds numbers are un-affordable by direct simulation (DNS), and simulations must either be performed by solving averaged equations (RANS), or by solving only the large eddies (LES), both using a wall model. A first investigation of this thesis dealt with the derivation and test of two variable density wall models: an algebraic law (CWM) and a zonal approach dedicated to LES (TBLE-ρ). These models were validated in quasi-isothermal cases, before being used in academic and industrial non-isothermal flows with satisfactory results. Then, a numerical experiment of pulsed passive scalars was performed by DNS, were two forcing conditions were considered: oscillations are imposed in the outer flow; oscillations come from the wall. Several frequencies and amplitudes of oscillations were taken into account in order to gain insights in unsteady effects in the boundary layer, and to create a database for validating wall models in such context. The temporal behaviour of two wall models (algebraic and zonal wall models) were studied and showed that a zonal model produced better results when used in the simulation of unsteady flows. (author)

  17. Improved nonlinear fault detection strategy based on the Hellinger distance metric: Plug flow reactor monitoring

    KAUST Repository

    Harrou, Fouzi

    2017-03-18

    Fault detection has a vital role in the process industry to enhance productivity, efficiency, and safety, and to avoid expensive maintenance. This paper proposes an innovative multivariate fault detection method that can be used for monitoring nonlinear processes. The proposed method merges advantages of nonlinear projection to latent structures (NLPLS) modeling and those of Hellinger distance (HD) metric to identify abnormal changes in highly correlated multivariate data. Specifically, the HD is used to quantify the dissimilarity between current NLPLS-based residual and reference probability distributions obtained using fault-free data. Furthermore, to enhance further the robustness of these methods to measurement noise, and reduce the false alarms due to modeling errors, wavelet-based multiscale filtering of residuals is used before the application of the HD-based monitoring scheme. The performances of the developed NLPLS-HD fault detection technique is illustrated using simulated plug flow reactor data. The results show that the proposed method provides favorable performance for detection of faults compared to the conventional NLPLS method.

  18. A horizontal plug-flow baffled bioelectrocatalyzed reactor for the reductive decolorization of Alizarin Yellow R.

    Science.gov (United States)

    Sun, Qian; Li, Zhiling; Wang, Youzhao; Cui, Dan; Liang, Bin; Thangavel, Sangeetha; Chung, Jong Shik; Wang, Aijie

    2015-11-01

    An application-oriented membrane-free, continuous plug-flow baffled bioelectrocatalyzed reactor (PFB-BER), was designed and testified for the decolorization of Alizarin Yellow R. Decolorization efficiency (DE) with an external power source of 0.5 V was higher than without electrolysis, i.e. 93.4% versus 73.6% (HRT of 24 h). Product formation efficiencies of p-phenylenediamine and 5-aminosalicylic acid were above 95% and 50%, respectively. When HRT decreased to 8 h and 4 h, DE reduced to 69.9% and 44.9%, respectively. An additional electrode assembly improved DE to 96.4% (HRT of 8 h) and 80% (HRT of 4 h), while energy consumption (HRT of 4 h) was lower than that of HRT of 12 h with single electrode assembly under comparable DE. The PFB-BER with higher removal capacity, lower internal resistance and energy consumption provides a new solution to treat the high loading azo dye-containing wastewaters. Copyright © 2015. Published by Elsevier Ltd.

  19. Low-temperature anaerobic digestion of swine manure in a plug-flow reactor.

    Science.gov (United States)

    Massé, Daniel I; Gilbert, Yan; Saady, N M C; Liu, Charle

    2013-01-01

    A low-temperature (25 degrees C) anaerobic eight-compartment (PF01 to PF08) cascade reactor simulating a plug-flow reactor (PFR) treating pig manure was monitored for a year. The bioreactor was fed at an average loading rate of 2.4 +/- 0.2 g of total chemical oxygen demand (TCOD) per litre of reactor per day for a theoretical hydraulic retention time (HRT) of 67 +/- 7 d. An average of 79% of TCOD was removed from pig manure (converted into biogas and in sediments), whereas specific methane yields ranging from 397 to 482 NL CH4 kg(-1) VS (148.6 to 171.4 NL CH4 kg(-1) TCOD) were obtained. After 150 d, fluctuating performances of the process were observed, associated with solids accumulation in the upstream compartments, preventing the complete anaerobic digestion of swine manure in the compartments PF01 to PF04. Low-temperature anaerobic PFR represents an interesting alternative for the treatment of pig manure and recovery of green energy. Further investigations regarding a modified design, with better accumulating solids management, are needed to optimize the performance of this low-temperature PFR treating pig manure.

  20. Rarefied gas flow in a rectangular enclosure induced by non-isothermal walls

    Energy Technology Data Exchange (ETDEWEB)

    Vargas, Manuel; Tatsios, Giorgos; Valougeorgis, Dimitris, E-mail: diva@mie.uth.gr [Department of Mechanical Engineering, University of Thessaly, 38334 Volos (Greece); Stefanov, Stefan [Institute of Mechanics, Bulgarian Academy of Sciences, Sofia (Bulgaria)

    2014-05-15

    The flow of a rarefied gas in a rectangular enclosure due to the non-isothermal walls with no synergetic contributions from external force fields is investigated. The top and bottom walls are maintained at constant but different temperatures and along the lateral walls a linear temperature profile is assumed. Modeling is based on the direct numerical solution of the Shakhov kinetic equation and the Direct Simulation Monte Carlo (DSMC) method. Solving the problem both deterministically and stochastically allows a systematic comparison and verification of the results as well as the exploitation of the numerical advantages of each approach in the investigation of the involved flow and heat transfer phenomena. The thermally induced flow is simulated in terms of three dimensionless parameters characterizing the problem, namely, the reference Knudsen number, the temperature ratio of the bottom over the top plates, and the enclosure aspect ratio. Their effect on the flow configuration and bulk quantities is thoroughly examined. Along the side walls, the gas flows at small Knudsen numbers from cold-to-hot, while as the Knudsen number is increased the gas flows from hot-to-cold and the thermally induced flow configuration becomes more complex. These flow patterns with the hot-to-cold flow to be extended to the whole length of the non-isothermal side walls may exist even at small temperature differences and then, they are enhanced as the temperature difference between the top and bottom plates is increased. The cavity aspect ratio also influences this flow configuration and the hot-to-cold flow is becoming more dominant as the depth compared to the width of the cavity is increased. To further analyze the flow patterns a novel solution decomposition into ballistic and collision parts is introduced. This is achieved by accordingly modifying the indexing process of the typical DSMC algorithm. The contribution of each part of the solution is separately examined and a physical

  1. Porous plug phase separator and superfluid film flow suppression system for the soft x-ray spectrometer onboard Hitomi

    Science.gov (United States)

    Ezoe, Yuichiro; DiPirro, Michael; Fujimoto, Ryuichi; Ishikawa, Kumi; Ishisaki, Yoshitaka; Kanao, Kenichi; Kimball, Mark; Mitsuda, Kazuhisa; Mitsuishi, Ikuyuki; Murakami, Masahide; Noda, Hirofumi; Ohashi, Takaya; Okamoto, Atsushi; Satoh, Yohichi; Sato, Kosuke; Shirron, Peter; Tsunematsu, Shoji; Yamaguchi, Hiroya; Yoshida, Seiji

    2018-01-01

    When using superfluid helium in low-gravity environments, porous plug phase separators are commonly used to vent boil-off gas while confining the bulk liquid to the tank. Invariably, there is a flow of superfluid film from the perimeter of the porous plug down the vent line. For the soft x-ray spectrometer onboard ASTRO-H (Hitomi), its approximately 30-liter helium supply has a lifetime requirement of more than 3 years. A nominal vent rate is estimated as ˜30 μg/s, equivalent to ˜0.7 mW heat load. It is, therefore, critical to suppress any film flow whose evaporation would not provide direct cooling of the remaining liquid helium. That is, the porous plug vent system must be designed to both minimize film flow and to ensure maximum extraction of latent heat from the film. The design goal for Hitomi is to reduce the film flow losses to knife-edge devices. Design, on-ground testing results, and in-orbit performance are described.

  2. Large eddy simulations of isothermal confined swirling flow in an industrial gas-turbine

    International Nuclear Information System (INIS)

    Bulat, G.; Jones, W.P.; Navarro-Martinez, S.

    2015-01-01

    Highlights: • We conduct a large eddy simulation of an industrial gas turbine. • The results are compared with measurements obtained under isothermal conditions. • The method reproduces the observed precessing vortex and central vortex cores. • The profiles of mean and rms velocities are found to be captured to a good accuracy. - Abstract: The paper describes the results of a computational study of the strongly swirling isothermal flow in the combustion chamber of an industrial gas turbine. The flow field characteristics are computed using large eddy simulation in conjunction with a dynamic version of the Smagorinsky model for the sub-grid-scale stresses. Grid refinement studies demonstrate that the results are essentially grid independent. The LES results are compared with an extensive set of measurements and the agreement with these is overall good. The method is shown to be capable of reproducing the observed precessing vortex and central vortex cores and the profiles of mean and rms velocities are found to be captured to a good accuracy. The overall flow structure is shown to be virtually independent of Reynolds number

  3. Study of flow past an exponentially accelerated isothermal vertical plate in the presence of chemical reaction

    Directory of Open Access Journals (Sweden)

    Muthucumaraswamy R.

    2010-01-01

    Full Text Available Theoretical study of unsteady flow past an exponentially accelerated infinite isothermal vertical plate with variable mass diffusion has been presented in the presence of homogeneous chemical reaction of first order. The plate temperature is raised to Tw and species concentration level near the plate is made to rise linearly with time. The dimensionless governing equations are solved using Laplace-transform technique. The velocity profiles are studied for different physical parameters like chemical reaction parameter, thermal Grashof number, mass Grashof number, a and time. It is observed that the velocity increases with increasing values of a or t. But the trend is just reversed with respect to K.

  4. Non-isothermal compositional gas flow during carbon dioxide storage and enhanced gas recovery

    DEFF Research Database (Denmark)

    Singh, Ashok; Böettcher, N.; Wang, W.

    2011-01-01

    In this work we present the conceptual modeling and the numerical scheme for carbon dioxide storage into nearly depleted gas reservoirs for enhanced gas recovery reasons. For this we develop non-isothermal compositional gas flow model. We used a combined monolithic / staggered coupling scheme...... to solve mass balance equation for the gaseous mixture with heat and fractional mass transport equations. Temperature change resulting from fluid expansion and viscous heat dissipation is included in heat transport in addition to advection and conduction. We have used a modified version of the Peng...

  5. High-Flow Renal Arteriovenous Fistula Treated with the Amplatzer Vascular Plug: Implementation of an Arterial and Venous Approach

    International Nuclear Information System (INIS)

    Brountzos, Elias N.; Ptohis, Nikolaos; Grammenou-Pomoni, Maria; Panagiotou, Irini; Kelekis, Dimitrios; Gouliamos, Athanasios; Kelekis, Nikolaos

    2009-01-01

    We present a 28-year-old man with a large symptomatic arteriovenous fistula (AVF) treated with embolization using the Amplatzer vascular plug (AVP). Although embolization may be considered the first-line therapy in the treatment of AVFs, there is an inherent high risk of migration of the embolic agents into the venous and pulmonary circulations. This case is illustrative of the ease and safety of using this device in high-flow renal AVFs.

  6. PIV Measurement of Isothermal Flow in the Moderator Circulation Test (MCT) Facility

    Energy Technology Data Exchange (ETDEWEB)

    Im, Sunghyuk; Sung, Hyung Jin [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Seo, Han; Bang, In Cheol [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of); Kim, Hyoung Tae [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    One of the important design features of a CANDU reactor (a pressurize heavy water reactor) is the use of moderator as a heat sink during some postulated accidents such as a large break Loss Of Coolant Accident (LOCA). If the moderator available subcooling at the onset of a large LOCA is greater than the subcooling requirements, a sustained calandria tube dryout is avoided. The subcooling requirements are determined from a set of experiments known as the fuel channel contact boiling experiments. The difference between available subcooling and required subcooling is called subcooling margins. The local temperature of the moderator is a key parameter in determining the available subcooling. To predict the local temperature in the calandria, Korea Atomic Energy Research Institute (KAERI) started the experimental research on moderator circulation as one of a national R and D research programs from 2012. In the present work the test vessel is equipment with 380 acrylic pipes instead of the heater rods and a preliminary measurement of velocity field using PIV is performed under the iso-thermal test conditions. The 2D velocity is measured on the cross-sectional plane normal to the axial direction of the tank. The PIV measurement results could capture the same flow pattern as that expected in the CANDU6 calandria tank under momentum dominant flow condition, where the inlet jets penetrate to the top of the tank and produce a downward flow through the center of the tube columns towards the outlet nozzle and the flow fields are in symmetric distributions. The measurements of downward velocities are performed at different locations. The velocity is shown to be axially uniform. The velocity is rapidly decreased as the measurement location is far from the center of tank, since the downward flow is dominant along the center of the tube columns. More experimental works for the iso-thermal conditions as well as the heating conditions will be performed using PIV measurement in the

  7. PIV Measurement of Isothermal Flow in the Moderator Circulation Test (MCT) Facility

    International Nuclear Information System (INIS)

    Im, Sunghyuk; Sung, Hyung Jin; Seo, Han; Bang, In Cheol; Kim, Hyoung Tae

    2014-01-01

    One of the important design features of a CANDU reactor (a pressurize heavy water reactor) is the use of moderator as a heat sink during some postulated accidents such as a large break Loss Of Coolant Accident (LOCA). If the moderator available subcooling at the onset of a large LOCA is greater than the subcooling requirements, a sustained calandria tube dryout is avoided. The subcooling requirements are determined from a set of experiments known as the fuel channel contact boiling experiments. The difference between available subcooling and required subcooling is called subcooling margins. The local temperature of the moderator is a key parameter in determining the available subcooling. To predict the local temperature in the calandria, Korea Atomic Energy Research Institute (KAERI) started the experimental research on moderator circulation as one of a national R and D research programs from 2012. In the present work the test vessel is equipment with 380 acrylic pipes instead of the heater rods and a preliminary measurement of velocity field using PIV is performed under the iso-thermal test conditions. The 2D velocity is measured on the cross-sectional plane normal to the axial direction of the tank. The PIV measurement results could capture the same flow pattern as that expected in the CANDU6 calandria tank under momentum dominant flow condition, where the inlet jets penetrate to the top of the tank and produce a downward flow through the center of the tube columns towards the outlet nozzle and the flow fields are in symmetric distributions. The measurements of downward velocities are performed at different locations. The velocity is shown to be axially uniform. The velocity is rapidly decreased as the measurement location is far from the center of tank, since the downward flow is dominant along the center of the tube columns. More experimental works for the iso-thermal conditions as well as the heating conditions will be performed using PIV measurement in the

  8. Non-isothermal modelling of the all-vanadium redox flow battery

    International Nuclear Information System (INIS)

    Al-Fetlawi, H.; Shah, A.A.; Walsh, F.C.

    2009-01-01

    An non-isothermal model for the all-vanadium redox flow battery (RFB) is presented. The two-dimensional model is based on a comprehensive description of mass, charge, energy and momentum transport and conservation, and is combined with a global kinetic model for reactions involving vanadium species. Heat is generated as a result of activation losses, electrochemical reaction and ohmic resistance. Numerical simulations demonstrate the effects of changes in the operating temperature on performance. It is shown that variations in the electrolyte flow rate and the magnitude of the applied current substantially alter the charge/discharge characteristics, the temperature rise and the distribution of temperature. The influence of heat losses on the charge/discharge behaviour and temperature distribution is investigated. Conditions for localised heating and membrane degradation are discussed.

  9. Hydrodynamic boundary conditions for one-component liquid-gas flows on non-isothermal solid substrates

    KAUST Repository

    Xu, Xinpeng; Liu, Chun; Qian, Tiezheng

    2012-01-01

    profiles of liquid-gas flows on non-isothermal, heterogeneous solid substrates is still absent. The purpose of this work is to construct a continuum model for simulating the liquid-gas flows on solid surfaces that are flat and rigid, and may involve

  10. Wall modeling for the simulation of highly non-isothermal unsteady flows; Modelisation de paroi pour la simulation d'ecoulements instationnaires non-isothermes

    Energy Technology Data Exchange (ETDEWEB)

    Devesa, A

    2006-12-15

    Nuclear industry flows are most of the time characterized by their high Reynolds number, density variations (at low Mach numbers) and a highly unsteady behaviour (low to moderate frequencies). High Reynolds numbers are un-affordable by direct simulation (DNS), and simulations must either be performed by solving averaged equations (RANS), or by solving only the large eddies (LES), both using a wall model. A first investigation of this thesis dealt with the derivation and test of two variable density wall models: an algebraic law (CWM) and a zonal approach dedicated to LES (TBLE-{rho}). These models were validated in quasi-isothermal cases, before being used in academic and industrial non-isothermal flows with satisfactory results. Then, a numerical experiment of pulsed passive scalars was performed by DNS, were two forcing conditions were considered: oscillations are imposed in the outer flow; oscillations come from the wall. Several frequencies and amplitudes of oscillations were taken into account in order to gain insights in unsteady effects in the boundary layer, and to create a database for validating wall models in such context. The temporal behaviour of two wall models (algebraic and zonal wall models) were studied and showed that a zonal model produced better results when used in the simulation of unsteady flows. (author)

  11. Studies of non-isothermal flow in saturated and partially saturated porous media

    International Nuclear Information System (INIS)

    Ho, C.K.; Maki, K.S.; Glass, R.J.

    1993-01-01

    Physical and numerical experiments have been performed to investigate the behavior of nonisothermal flow in two-dimensional saturated and partially saturated porous media. The physical experiments were performed to identify non-isothermal flow fields and temperature distributions in fully saturated, half-saturated, and residually saturated two-dimensional porous media with bottom heating and top cooling. Two counter-rotating liquid-phase convective cells were observed to develop in the saturated regions of all three cases. Gas-phase convection was also evidenced in the unsaturated regions of the partially saturated experiments. TOUGH2 numerical simulations of the saturated case were found to be strongly dependent on the assumed boundary conditions of the physical system. Models including heat losses through the boundaries of the test cell produced temperature and flow fields that were in better agreement with the observed temperature and flow fields than models that assumed insulated boundary conditions. A sensitivity analysis also showed that a reduction of the bulk permeability of the porous media in the numerical simulations depressed the effects of convection, flattening the temperature profiles across the test cell

  12. Isothermal flow measurement using planar PIV in the 1/4 scaled model of CANDU reactor

    Energy Technology Data Exchange (ETDEWEB)

    Im, Sunghyuk; Sung, Hyung Jin [KAIST, Daejeon (Korea, Republic of); Seo, Han; Bang, In Cheol [UNIST, Ulsan (Korea, Republic of); Kim, Hyoung Tae [KAERI, Daejeon (Korea, Republic of)

    2015-05-15

    The local temperature of the moderator is a key parameter in determining the available subcooling. To predict the flow field and local temperature distribution in the calandria, Korea Atomic Energy Research Institute (KAERI) started the experimental research on moderator circulation as one of a national R and D research programs from 2012. This research program includes the construction of the Moderator Circulation Test (MCT) facility, production of the validation data for self-reliant CFD tools, and development of optical measurement system using the Particle Image Velocimetry (PIV) and Laser Induced Fluorescence (LIF) techniques. Small-scale 1/40 and 1/8 small-scale model tests were performed prior to installation of the main MCT facility to identify the potential problems of the flow visualization and measurement expected in the 1/4 scale MCT facility. In the 1/40 scale test, a flow field was measured with a PIV measurement technique under an iso-thermal state, and the temperature field was visualized using a LIF technique. In this experiment, the key point was to illuminate the region of interest as uniformly as possible since the velocity and temperature fields in the shadow regions were distorted and unphysical. In the 1/8 scale test, the flow patterns from the inlet nozzles to the top region of the tank were investigated using PIV measurement at two different positions of the inlet nozzle. For each position of laser beam exposure the measurement sections were divided to 7 groups to overcome the limitation of the laser power to cover the relatively large test section. The MCT facility is the large-scale facility designed to reproduce the important characteristics of moderator circulation in a CANDU6 calandria under a range of operating conditions. It is reduced in a 1/4 scale and a moderator test vessel is built to the specifications of the CANDU6 reactor design, where a working fluid is sub-cooled water with atmospheric pressure. Previous studies were

  13. Isothermal flow measurement using planar PIV in the 1/4 scaled model of CANDU reactor

    International Nuclear Information System (INIS)

    Im, Sunghyuk; Sung, Hyung Jin; Seo, Han; Bang, In Cheol; Kim, Hyoung Tae

    2015-01-01

    The local temperature of the moderator is a key parameter in determining the available subcooling. To predict the flow field and local temperature distribution in the calandria, Korea Atomic Energy Research Institute (KAERI) started the experimental research on moderator circulation as one of a national R and D research programs from 2012. This research program includes the construction of the Moderator Circulation Test (MCT) facility, production of the validation data for self-reliant CFD tools, and development of optical measurement system using the Particle Image Velocimetry (PIV) and Laser Induced Fluorescence (LIF) techniques. Small-scale 1/40 and 1/8 small-scale model tests were performed prior to installation of the main MCT facility to identify the potential problems of the flow visualization and measurement expected in the 1/4 scale MCT facility. In the 1/40 scale test, a flow field was measured with a PIV measurement technique under an iso-thermal state, and the temperature field was visualized using a LIF technique. In this experiment, the key point was to illuminate the region of interest as uniformly as possible since the velocity and temperature fields in the shadow regions were distorted and unphysical. In the 1/8 scale test, the flow patterns from the inlet nozzles to the top region of the tank were investigated using PIV measurement at two different positions of the inlet nozzle. For each position of laser beam exposure the measurement sections were divided to 7 groups to overcome the limitation of the laser power to cover the relatively large test section. The MCT facility is the large-scale facility designed to reproduce the important characteristics of moderator circulation in a CANDU6 calandria under a range of operating conditions. It is reduced in a 1/4 scale and a moderator test vessel is built to the specifications of the CANDU6 reactor design, where a working fluid is sub-cooled water with atmospheric pressure. Previous studies were

  14. Heat transfer analysis for unsteady MHD flow past a non-isothermal stretching surface

    International Nuclear Information System (INIS)

    Mukhopadhyay, Swati

    2011-01-01

    Highlights: ► Unsteady boundary layer flow and heat transfer over a non-isothermal stretching sheet in a magnetic field are studied. ► Fluid velocity and temperature decrease for increasing unsteadiness parameter. ► Fluid velocity decreases but temperature increases with the increasing values of the Hartman number. ► The sheet temperature in respect of distance and time has analogous effects on the heat transfer. - Abstract: An analysis is made for the unsteady two-dimensional magneto-hydrodynamic flow of an incompressible viscous and electrically conducting fluid over a stretching surface having a variable and general form of surface temperature which removes the restrictions of the particular forms of prescribed surface temperature. Similarity solutions for the transformed governing equations are obtained. The transformed boundary layer equations are solved numerically for some values of the involved parameters, namely the unsteadiness parameter, magnetic parameter, the temperature exponent parameters. The features of the flow and heat transfer characteristics for different values of the governing parameters are analysed and discussed. It is found that the fluid velocity and temperature decrease for increasing unsteadiness parameter. Fluid velocity decreases with the increasing values of the Hartman number resulting an increase in the temperature field in steady as well in unsteady case. It is observed that the variation of the sheet temperature in respect of distance and time has analogous effects both on the free surface temperature and on the heat transfer rate (Nusselt number) at the sheet.

  15. Demineralized water flow cancelling experiments with ice plug into high diameter horizontal tube (300 nominal diameter)

    International Nuclear Information System (INIS)

    Gyongyosi, T.; Valeca, S.; Corbescu, B.; Puiu, D.; Panaitescu, V. N.

    2015-01-01

    The isolation with ice plug of a high diameter horizontal pipeline section is a specific technique for repairs activities/ replacements of components owning to thermo-hydraulic installations working with liquid agents. The application of such technique don.t assumes stopping of the entire system. The ice plugging inside of the pipeline assumes using of a special device and of an own specific technology for application. The paper contains a brief description of the experimental technological facilities used, followed by setting off the main moments in evolution of two experimental tests carried out on the test section with 300 mm nominal diameter for demineralized water and, finally, by a brief results analysis and some conclusions. The paper is dedicated to the specialists working in the research and technological engineering. (authors)

  16. Comparison of reynolds averaged navier stokes based simulation and large eddy simulation for one isothermal swirling flow

    DEFF Research Database (Denmark)

    Yang, Yang; Kær, Søren Knudsen

    2012-01-01

    The flow structure of one isothermal swirling case in the Sydney swirl flame database was studied using two numerical methods. Results from the Reynolds-averaged Navier-Stokes (RANS) approach and large eddy simulation (LES) were compared with experimental measurements. The simulations were applied...

  17. Isothermal Recombinase Polymerase amplification (RPA) of Schistosoma haematobium DNA and oligochromatographic lateral flow detection.

    Science.gov (United States)

    Rosser, A; Rollinson, D; Forrest, M; Webster, B L

    2015-09-04

    Accurate diagnosis of urogenital schistosomiasis is vital for surveillance/control programs. Amplification of schistosome DNA in urine by PCR is sensitive and specific but requires infrastructure, financial resources and skilled personnel, often not available in endemic areas. Recombinase Polymerase Amplification (RPA) is an isothermal DNA amplification/detection technology that is simple, rapid, portable and needs few resources. Here a Schistosoma haematobium RPA assay was developed and adapted so that DNA amplicons could be detected using oligochromatographic Lateral Flow (LF) strips. The assay successfully amplified S. haematobium DNA at 30-45 °C in 10 mins and was sensitive to a lower limit of 100 fg of DNA. The assay was also successful with the addition of crude urine, up to 5% of the total reaction volume. Cross amplification occurred with other schistosome species but not with other common urine microorganisms. The LF-RPA assay developed here can amplify and detect low levels of S. haematobium DNA. Reactions are rapid, require low temperatures and positive reactions are interpreted using lateral flow strips, reducing the need for infrastructure and resources. This together with an ability to withstand inhibitors within urine makes RPA a promising technology for further development as a molecular diagnostic tool for urogenital schistosomiasis.

  18. Modeling of isothermal bubbly flow with interfacial area transport equation and bubble number density approach

    Energy Technology Data Exchange (ETDEWEB)

    Sari, Salih [Hacettepe University, Department of Nuclear Engineering, Beytepe, 06800 Ankara (Turkey); Erguen, Sule [Hacettepe University, Department of Nuclear Engineering, Beytepe, 06800 Ankara (Turkey); Barik, Muhammet; Kocar, Cemil; Soekmen, Cemal Niyazi [Hacettepe University, Department of Nuclear Engineering, Beytepe, 06800 Ankara (Turkey)

    2009-03-15

    In this study, isothermal turbulent bubbly flow is mechanistically modeled. For the modeling, Fluent version 6.3.26 is used as the computational fluid dynamics solver. First, the mechanistic models that simulate the interphase momentum transfer between the gas (bubbles) and liquid (continuous) phases are investigated, and proper models for the known flow conditions are selected. Second, an interfacial area transport equation (IATE) solution is added to Fluent's solution scheme in order to model the interphase momentum transfer mechanisms. In addition to solving IATE, bubble number density (BND) approach is also added to Fluent and this approach is also used in the simulations. Different source/sink models derived for the IATE and BND models are also investigated. The simulations of experiments based on the available data in literature are performed by using IATE and BND models in two and three-dimensions. The results show that the simulations performed by using IATE and BND models agree with each other and with the experimental data. The simulations performed in three-dimensions give better agreement with the experimental data.

  19. Modeling of isothermal bubbly flow with interfacial area transport equation and bubble number density approach

    International Nuclear Information System (INIS)

    Sari, Salih; Erguen, Sule; Barik, Muhammet; Kocar, Cemil; Soekmen, Cemal Niyazi

    2009-01-01

    In this study, isothermal turbulent bubbly flow is mechanistically modeled. For the modeling, Fluent version 6.3.26 is used as the computational fluid dynamics solver. First, the mechanistic models that simulate the interphase momentum transfer between the gas (bubbles) and liquid (continuous) phases are investigated, and proper models for the known flow conditions are selected. Second, an interfacial area transport equation (IATE) solution is added to Fluent's solution scheme in order to model the interphase momentum transfer mechanisms. In addition to solving IATE, bubble number density (BND) approach is also added to Fluent and this approach is also used in the simulations. Different source/sink models derived for the IATE and BND models are also investigated. The simulations of experiments based on the available data in literature are performed by using IATE and BND models in two and three-dimensions. The results show that the simulations performed by using IATE and BND models agree with each other and with the experimental data. The simulations performed in three-dimensions give better agreement with the experimental data

  20. Vascular plugs - A key companion to Interventionists - 'Just Plug it'.

    Science.gov (United States)

    Ramakrishnan, Sivasubramanian

    2015-01-01

    Vascular plugs are ideally suited to close extra-cardiac, high flowing vascular communications. The family of vascular plugs has expanded. Vascular plugs in general have a lower profile and the newer variants can be delivered even through a diagnostic catheter. These features make them versatile and easy to use. The Amplatzer vascular plugs are also used for closing intracardiac defects including coronary arterio-venous fistula and paravalvular leakage in an off-label fashion. In this review, the features of currently available vascular plugs are reviewed along with tips and tricks of using them in the cardiac catheterization laboratory. Copyright © 2015. Published by Elsevier B.V.

  1. Development Characteristics of Velocity Transports in An Isothermal Heated Drag-Reducing Surfactant Solution Flow

    Science.gov (United States)

    Zhang, Hongxia; Wang, Dezhong; Chen, Hanping; Wang, Yanping

    2007-06-01

    The development characteristics, turbulence transports for stresses and kinetic energy of a cetyltrimethyl ammonium chloride (CTAC) surfactant solution for a two-dimensional channel flow have been experimentally investigated. Time mean velocity and fluctuating velocity are measured using a Phase Doppler Anemometry (PDA) at the Reynolds number 1.78×104 and isothermal heated temperature 31°C. Although mean velocity profiles at three cross sections show that the fluid is almost fully developed, the peak location of fluctuating intensity for the CTAC solution is slightly away from the wall downstream from the fluid and the peak location of fluctuating intensity is observed at far away from the wall than that of water. The location where the velocity gradient has its maximum, the fluctuating intensity does not get the high value. The elastic shear stress contribution to the total shear stress is 15 percents to 36 percents and it gets to the maximum near to the wall. The surfactant elastic shear stress is almost a liner function of the height of the channel, which means that the elastic stress contribution of the different cross locations is approximately the same. The fluctuating surfactant stress work is negative and the fluctuating elastic shear stresses produce rather than dissipate kinetic energy.

  2. Simple system for isothermal DNA amplification coupled to lateral flow detection.

    Directory of Open Access Journals (Sweden)

    Kristina Roskos

    Full Text Available Infectious disease diagnosis in point-of-care settings can be greatly improved through integrated, automated nucleic acid testing devices. We have developed an early prototype for a low-cost system which executes isothermal DNA amplification coupled to nucleic acid lateral flow (NALF detection in a mesofluidic cartridge attached to a portable instrument. Fluid handling inside the cartridge is facilitated through one-way passive valves, flexible pouches, and electrolysis-driven pumps, which promotes a compact and inexpensive instrument design. The closed-system disposable prevents workspace amplicon contamination. The cartridge design is based on standard scalable manufacturing techniques such as injection molding. Nucleic acid amplification occurs in a two-layer pouch that enables efficient heat transfer. We have demonstrated as proof of principle the amplification and detection of Mycobacterium tuberculosis (M.tb genomic DNA in the cartridge, using either Loop Mediated Amplification (LAMP or the Exponential Amplification Reaction (EXPAR, both coupled to NALF detection. We envision that a refined version of this cartridge, including upstream sample preparation coupled to amplification and detection, will enable fully-automated sample-in to answer-out infectious disease diagnosis in primary care settings of low-resource countries with high disease burden.

  3. Effects of mixing technologies on continuous methyl ester production: Comparison of using plug flow, static mixer, and ultrasound clamp

    International Nuclear Information System (INIS)

    Somnuk, Krit; Prasit, Tanongsak; Prateepchaikul, Gumpon

    2017-01-01

    Highlights: • Four types of continuous reactors were compared with methyl ester conversion. • Plug flow, static mixer, ultrasound clamp, SM with ultrasound reactors were tested. • The 16 × 400 W ultrasound clamps were operated at 20 kHz frequency for US reactor. • The US reactor was clearly superior over the other types of continuous reactor. • The US reactor was the most effective alternative with short reactor length. - Abstract: Four types of continuous reactors, namely plug flow reactor (PF), static mixer reactor (SM), ultrasound clamp on tubular reactor (US), and static mixer combined with ultrasound (SM/US) were compared for their purities of methyl ester in biodiesel production from refined palm oil (RPO). The reactor conditions were: KOH 4, 6, 8, 10, and 12 g L −1 , methanol content 20 vol.%, and under 20 L h −1 RPO flow rate at 60 °C temperature. The highest purity of methyl esters: 81.99 wt.% for PF, 95.70 wt.% for SM, 98.98 wt.% for US, and 97.67 wt.% for SM/US, were achieved with 900 mm, 900 mm, 700 mm, and 900 mm reactor lengths respectively, and 12 g L −1 of KOH was used in all cases. The 16 × 400 W ultrasound clamp was operated at 20 kHz frequency, and among short length reactors the US case was more effective than PF, SM, or SM/US. Moreover, ester purity from the US reactor was slightly decreased by the lowest 4 g L −1 KOH. The US reactor was clearly superior over the other types of continuous reactor, and had the potential to reduce KOH consumption by sonochemical effects on the base-catalyzed transesterification reaction.

  4. Dry fermentation of manure with straw in continuous plug flow reactor: Reactor development and process stability at different loading rates.

    Science.gov (United States)

    Patinvoh, Regina J; Kalantar Mehrjerdi, Adib; Sárvári Horváth, Ilona; Taherzadeh, Mohammad J

    2017-01-01

    In this work, a plug flow reactor was developed for continuous dry digestion processes and its efficiency was investigated using untreated manure bedded with straw at 22% total solids content. This newly developed reactor worked successfully for 230days at increasing organic loading rates of 2.8, 4.2 and 6gVS/L/d and retention times of 60, 40 and 28days, respectively. Organic loading rates up to 4.2gVS/L/d gave a better process stability, with methane yields up to 0.163LCH 4 /gVS added /d which is 56% of the theoretical yield. Further increase of organic loading rate to 6gVS/L/d caused process instability with lower volatile solid removal efficiency and cellulose degradation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Photocatalytic mineralization of glyphosate in a small-scale plug flow simulation reactor by UV/TiO2.

    Science.gov (United States)

    Chen, Jian Q; Hu, Zhi J; Wang, Nan X

    2012-01-01

    The present work involves the photocatalytic mineralization of glyphosate on a plug flow reactor by UV/TiO(2). The effect of catalyst loading shows an optimal value (0.4 g L(-1)) which is necessary to mineralize glyphosate. The kinetic rate of glyphosate mineralization decreases with the increasing initial concentration of glyphosate, and the data can be described using the first-order model. An alkaline environment is conducive to glyphosate mineralization. The mineralization efficiency increases with elevated flow rate to 114 mL min(-1), which is followed by a decrease with a further increase in flow rate due to the reduction of the residence time. The presence of external oxidants (K(2)S(2)O(8), H(2)O(2) and KBrO(3)) and photosencitizer (humic acid) can significantly enhance glyphosate mineralization. Photocatalysis oxidation ability of the three studied oxidants decrease in the order of: S(2)O(8)(2-) > BrO(3)(-) > H(2)O(2). Finally, the Langmuir-Hinshelwood (L-H) model was used to rationalize the mechanisms of reactions occurring on TiO(2) surfaces and L-H model constants were also determined. Copyright © Taylor & Francis Group, LLC

  6. Pressure loss coefficient and flow rate of side hole in a lower end plug for dual-cooled annular nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Chang-Hwan, E-mail: shinch@kaeri.re.kr; Park, Ju-Yong, E-mail: juyong@kaeri.re.kr; In, Wang-Kee, E-mail: wkin@kaeri.re.kr

    2013-12-15

    Highlights: • A lower end plug with side flow holes is suggested to provide alternative flow paths of the inner channel. • The inlet loss coefficient of the lower end plug is estimated from the experiment. • The flow rate through the side holes is estimated in a complete entrance blockage of inner channel. • The consequence in the reactor core condition is evaluated with a subchannel analysis code. - Abstract: Dual-cooled annular nuclear fuel for a pressurized water reactor (PWR) has been introduced for a significant increase in reactor power. KAERI has been developing a dual-cooled annular fuel for a power uprate of 20% in an optimized PWR in Korea, the OPR1000. This annular fuel can help decrease the fuel temperature substantially relative to conventional cylindrical fuel at a power uprate. Annular fuel has dual flow channels around itself; however, the inner flow channel has a weakness in that it is isolated unlike the outer flow channel, which is open to other neighbouring outer channels for a coolant exchange in the reactor core. If the entrance of the inner channel is, as a hypothetical event, completely blocked by debris, the inner channel will then experience a rapid increase in coolant temperature such that a departure from nucleate boiling (DNB) may occur. Therefore, a remedy to avoid such a postulated accident is indispensable for the safety of annular fuel. A lower end plug with side flow holes was suggested to provide alternative flow paths in addition to the central entrance of the inner channel. In this paper, the inlet loss coefficient of the lower end plug and the flow rate through the side holes were estimated from the experimental results even in a complete entrance blockage of the inner channel. An optimization for the side hole was also performed, and the results are applied to a subchannel analysis to evaluate the consequence in the reactor core condition.

  7. Application Of Lean Strategy To Redesign The Assembly Process Flow Of Glow Plug

    Directory of Open Access Journals (Sweden)

    Rahul Vylen

    2013-06-01

    Full Text Available Lean manufacturing is an applied methodology of scientific objective techniques which will improve the tasks in a process to be performed with a minimum of non-value-added activities. It is being increasingly adopted as a potential solution for many automotive manufacturing industries. This paper addresses the implementation of lean principles in an automotive component manufacturing company with a focus on current manufacturing practices and visual identification of non-value-added time, such as bottle necking, waiting time and material handling, etc. The typical operations involved in making the Glow Plug are caulking, tig welding, MgO filling & O-ring pressing, swaging, facing, thread rolling, inspection and assembly. The facing operation can be eliminated by stabilizing the variations generated during the MgO filling machine. The MgO filling activity contains various forms of non-value-added activities such as worn-out gripper, insufficient clamping tension, physical shaking of the WPC on the agitation unit instead of fine vibration, Jerky insertion of the WPC shank into the agitation locator. It was identified that approximately 15mm material was wasted per piece, though there is no value addition on the part. This project utilizes Lean tools such as “Six Sigma” and “Value Stream Mapping” procedures. Resolving and improving the above problems resulted in drastic increase in productivity by 87% from 82%, reduction in the rejections by 13% from 18%, reduction in the manufacturing lead time by 2.62 days/annum, reduction in the utilization of shop floor space by 6m2 and also the manufacturing cost by 1.16 million INR/ annum.

  8. A capillary-based multiplexed isothermal nucleic acid-based test for sexually transmitted diseases in patients.

    Science.gov (United States)

    Xu, Gaolian; Zhao, Hang; Cooper, Jonathan M; Reboud, Julien

    2016-10-06

    We demonstrate a multiplexed loop mediated isothermal amplification (LAMP) assay for infectious disease diagnostics, where the analytical process flow of target pathogens genomic DNA is performed manually by moving magnetic beads through a series of plugs in a capillary. Heat is provided by a water bath and the results are read by the naked eye, enabling applications in low resource settings.

  9. Start-up adjustment of a plug-flow digester for cassava wastewater (manipueira treatment Processo de partida de um biodigestor do tipo plug-flow para tratamento da manipueira

    Directory of Open Access Journals (Sweden)

    Maria Magdalena Ferreira Ribas

    2003-01-01

    Full Text Available Manipueira, wastewater of cassava (Manihot esculenta processing, can be treated by anaerobic biodigestion. To study the start-up process of a plug-flow digester for manipueira treatment, this work consisted of two stages: gradual decrease of the hydraulic retention time (HRT to the preset time of 4 days or maintaining a fixed HRT of 4 days with gradual increase of the substrate concentration. A digester of 1980 mL capacity was opperated, at constant temperature (32 ± 1º C, with substrate pH corrected between 5.5 and 6.0. The first stage had durations of 16.6; 13.6; 11.6; and 9.6 days and the organic loads were 3.1; 2.0; 2.3; and 2.9 COD L-1 d-1, (chemical oxigen demand respectively. The second stage was characterized by a fixed HRT (4 days and organic loads of 0.48; 0.86; 1.65; and 2.46 g COD L-1 d-1. Total solids (TS, volatile solids (VS, COD, alkalinity and volatile acidity were determined in the substrate and in the effluent. During the first stage, the HRT of 9.6 days and organic load of 2.9 g COD L-1 d-1 resulted in the best performence; reductions in COD, total and volatile solids were 60, 44 and 60%, respectively. During the second stage, with a 4-day HRT, the best results were achieved with the 0.86 g COD L-1 d-1 organic load, which provided reductions in COD, total and volatile solids of 71, 58 and 79%, respectively. The start-up of the plug-flow digester for manipueira treatment can be made by gradually by decreasing the HRT, or fixing HRT and increasing substrate concentration.Um dos resíduos gerados no processamento da mandioca (Manihot esculenta é a manipueira, passível de tratamento por biodigestão anaeróbia. Este trabalho objetivou estudar o processo de partida de um biodigestor tipo plug-flow, tratando manipueira de duas maneiras: diminuindo-se gradativamente o tempo de retenção hidráulica (TRH até se chegar ao tempo pré-estabelecido, quatro dias; ou mantendo-se o TRH fixo em quatro dias e aumentando-se gradativamente

  10. Mechanics Model of Plug Welding

    Science.gov (United States)

    Zuo, Q. K.; Nunes, A. C., Jr.

    2015-01-01

    An analytical model has been developed for the mechanics of friction plug welding. The model accounts for coupling of plastic deformation (material flow) and thermal response (plastic heating). The model predictions of the torque, energy, and pull force on the plug were compared to the data of a recent experiment, and the agreements between predictions and data are encouraging.

  11. Rotary plug

    International Nuclear Information System (INIS)

    Yamada, Keiji.

    1979-01-01

    Purpose: In a rotating plug of a reactor using a liquid metal as a coolant as in the case of a fbr type reactor, to prevent the ingress of Na vapor into the sliding surface of the rotating plug. Constitution: A rotating plug comprising a large disc covering the upper part of a reactor pressure vessel containing therein a liquid metal and forming surfaces for mounting a shielding device and various other devices, and at least one or more of small discs provided rotatably and eccentrically within said large disc, which is characterized in that an elastic member consisting of bellows and a sealing is interposed between said large disc and said small discs. (Nakamura, S.)

  12. Assessing the degree of plug flow in oxidation flow reactors (OFRs): a study on a potential aerosol mass (PAM) reactor

    Science.gov (United States)

    Mitroo, Dhruv; Sun, Yujian; Combest, Daniel P.; Kumar, Purushottam; Williams, Brent J.

    2018-03-01

    Oxidation flow reactors (OFRs) have been developed to achieve high degrees of oxidant exposures over relatively short space times (defined as the ratio of reactor volume to the volumetric flow rate). While, due to their increased use, attention has been paid to their ability to replicate realistic tropospheric reactions by modeling the chemistry inside the reactor, there is a desire to customize flow patterns. This work demonstrates the importance of decoupling tracer signal of the reactor from that of the tubing when experimentally obtaining these flow patterns. We modeled the residence time distributions (RTDs) inside the Washington University Potential Aerosol Mass (WU-PAM) reactor, an OFR, for a simple set of configurations by applying the tank-in-series (TIS) model, a one-parameter model, to a deconvolution algorithm. The value of the parameter, N, is close to unity for every case except one having the highest space time. Combined, the results suggest that volumetric flow rate affects mixing patterns more than use of our internals. We selected results from the simplest case, at 78 s space time with one inlet and one outlet, absent of baffles and spargers, and compared the experimental F curve to that of a computational fluid dynamics (CFD) simulation. The F curves, which represent the cumulative time spent in the reactor by flowing material, match reasonably well. We value that the use of a small aspect ratio reactor such as the WU-PAM reduces wall interactions; however sudden apertures introduce disturbances in the flow, and suggest applying the methodology of tracer testing described in this work to investigate RTDs in OFRs to observe the effect of modified inlets, outlets and use of internals prior to application (e.g., field deployment vs. laboratory study).

  13. Assessing the degree of plug flow in oxidation flow reactors (OFRs: a study on a potential aerosol mass (PAM reactor

    Directory of Open Access Journals (Sweden)

    D. Mitroo

    2018-03-01

    Full Text Available Oxidation flow reactors (OFRs have been developed to achieve high degrees of oxidant exposures over relatively short space times (defined as the ratio of reactor volume to the volumetric flow rate. While, due to their increased use, attention has been paid to their ability to replicate realistic tropospheric reactions by modeling the chemistry inside the reactor, there is a desire to customize flow patterns. This work demonstrates the importance of decoupling tracer signal of the reactor from that of the tubing when experimentally obtaining these flow patterns. We modeled the residence time distributions (RTDs inside the Washington University Potential Aerosol Mass (WU-PAM reactor, an OFR, for a simple set of configurations by applying the tank-in-series (TIS model, a one-parameter model, to a deconvolution algorithm. The value of the parameter, N, is close to unity for every case except one having the highest space time. Combined, the results suggest that volumetric flow rate affects mixing patterns more than use of our internals. We selected results from the simplest case, at 78 s space time with one inlet and one outlet, absent of baffles and spargers, and compared the experimental F curve to that of a computational fluid dynamics (CFD simulation. The F curves, which represent the cumulative time spent in the reactor by flowing material, match reasonably well. We value that the use of a small aspect ratio reactor such as the WU-PAM reduces wall interactions; however sudden apertures introduce disturbances in the flow, and suggest applying the methodology of tracer testing described in this work to investigate RTDs in OFRs to observe the effect of modified inlets, outlets and use of internals prior to application (e.g., field deployment vs. laboratory study.

  14. Plugging solution

    Energy Technology Data Exchange (ETDEWEB)

    Sharipov, A U; Yangirov, I Z

    1982-01-01

    A clay-powder, cement, and water-base plugging solution is proposed having reduced solution viscosity characteristics while maintaining tensile strength in cement stone. This solution utilizes silver graphite and its ingredients, by mass weight, are as follows: cement 51.2-54.3%; claypowder 6.06-9.1%; silver graphite 0.24-0.33%; with water making up the remainder.

  15. Water circulation in non-isothermal droplet-laden turbulent channel flow

    NARCIS (Netherlands)

    Russo, E; Kuerten, Johannes G.M.; van der Geld, C.W.M.; Geurts, Bernardus J.; Simos, T.; Psihoyios, G.; Tsitouras, Ch.

    2013-01-01

    We propose a point-particle model for two-way coupling of water droplets dispersed in turbulent flow of a carrier gas consisting of air and water vapor. An incompressible flow formulation is applied for direct numerical simulation (DNS) of turbulent channel flow with a warm and a cold wall. Compared

  16. Development of porous plug phase separator and superfluid film flow suppression system for the Soft X-ray Spectrometer onboard ASTRO-H

    Science.gov (United States)

    Ezoe, Yuichiro; Ishikawa, Kumi; Ohashi, Takaya; Yamaguchi, Hiroya; Mitsuda, Kazuhisa; Fujimoto, Ryuichi; Murakami, Masahide; Kanao, Kenichi; Yoshida, Seiji; Tsunematsu, Shoji; DiPirro, Michael; Shirron, Peter; the SXS Team

    2012-04-01

    ASTRO-H is the sixth Japanese astronomy satellite scheduled for launch in 2014. The Soft X-ray Spectrometer instrument is onboard ASTRO-H. This is a 6 × 6 array of X-ray microcalorimeters with an energy resolution of gravity, a porous plug phase separator made of sintered stainless is used. Since the vapor mass flow rate is only 29 μg/s, any additional superfluid film loss influences the lifetime of the liquid helium. Therefore, a film flow suppression system consisting of an orifice, a heat exchanger, and knife edge devices is adopted based on the design used for the X-ray Spectrometer onboard Suzaku. The film flow will be suppressed to <2 μg/s, sufficiently smaller than the vapor flow rate. In the present investigation, the design and ground experiments of a helium vent system composed of the porous plug and film flow suppression system are presented. The results show that the phase separation and the film flow suppression are satisfactorily achieved.

  17. Numerical modeling of isothermal and nonisothermal flow in unsaturated fractured rock: A review

    International Nuclear Information System (INIS)

    Pruess, K.; Wang, J.S.Y.

    1986-01-01

    The tuff formations at and near the Nevada Test Site are comprised of fractured-porous material, with hydrologic properties quite different from those encountered in most previous unsaturated flow studies dealing with soils. In the vicinity of the waste packages, flow is driven by high temperatures (exceeding 100 0 C) and large temperature gradients. The approximations developed in soil science for weakly nonisothermal flow are not applicable to this situation, and a multiphase description of flow is required, similar to approaches used in modeling of geothermal reservoirs and thermally enhance oil recovery. The conventional approach to unsaturated flow is applicable, however, to a variety of problems relating to natural (undisturbed) and far-field flow conditions. This paper reviews recent work on numerical modeling of unsaturated flow undertaken in the context of nuclear waste isolation studies. Concepts and applications of broader interest are summarized, and important issues are identified that have not been adequately explored. 84 refs, 8 figs

  18. Core barrel plug

    International Nuclear Information System (INIS)

    Tolino, R.W.; Hopkins, R.J.; Congleton, R.L.; Popalis, C.H.

    1986-01-01

    A plug is described for preventing flow through a port in a core barrel of a pressurized water nuclear reactor which consists of: a substantially cylindrical body formed with a cylindrical portion and a flange and defining a tapered leading open end with the other end being closed by an end plug attached to the flange, the body defining a bore therein extending from the open end to the end plug with the bore having a smaller diameter near the open end than near the end plug, the cylindrical portion having a lip near the open end and being formed with longitudinal slots extending from the open end toward the flange and extending entirely through the thickness of the cylindrical portion, the cylindrical portion having a circumferential first groove on the outer surface thereof located near the forwardmost portion of the cylindrical portion but not in the section of the cylindrical portion that has the slots therein, and a plurality of circumferential second grooves on the outer surface thereof located in the section of the cylindrical portion that has the slots therein, the first and second grooves establishing a seal between the cylindrical portion and the inside surface of the port when the cylindrical portion is expanded, and the flange and the end plug having a passageway defined therein for introducing a fluid into the body; a metal ring disposed in each of the second grooves; a mandrel slidably disposed and captured in the body and capable of being moved toward the open end of the body when the fluid is introduced through the passageway, thereby causing the cylindrical portion to be expanded into contact with the inside surface of the port; and a locking mechanism disposed in the end plug for preventing inadvertent movement of the mandrel

  19. Plug Power

    Energy Technology Data Exchange (ETDEWEB)

    Marsh, A. [Plug Power Inc., New York, NY (United States)

    2009-07-01

    This presentation described Plug Power's GenDrive hydrogen fuel cell unit that supplies the power needs for folk lift trucks used in high-throughput distribution and high-volume manufacturing operations. The system offers an alternative to lead acid batteries, providing maximum performance at all times during use. The system is particularly useful in the material handling industry, where the revenue generated is based on operator uptime and lift truck productivity. The use of the system allows customers to reduce operational costs and expand valuable floor space by eliminating batteries and associated recharging infrastructure. Fuel cell units also reduce the wear on truck motors. Truck operators can easily and safely refuel at hydrogen fueling stations in 1-5 minutes. GenDrive works with all major OEM lift trucks, making the transition seamless. Commercial customers are investing in this solution to improve their current operations. In 2008, Plug Power sold to Wal-Mart, Bridgestone Firestone and Nestle. Most notably, Central Grocers purchased 220 fuel cell units for a new greenfield distribution center. Plug Power currently has more than 380 systems in operation.

  20. Shielding plugs

    International Nuclear Information System (INIS)

    Makishima, Kenji.

    1986-01-01

    Purpose: In shielding plugs of an LMFBR type reactor, to restrain natural convection of heat in an annular space between a thermal shield layer and a shield shell, to prevent the lowering of heat-insulation performance, and to alleviate a thermal stress in a reactor container and the shield shell. Constitution: A ring-like leaf spring split in the direction of height is disposed in an annular space between a thermal shield layer and a shield shell. In consequence, the space is partitioned in the direction of height and, therefore, if axial temperature conditions and space width are the same and the space is low, the natural convection is hard to occur. Thus the rise of upper surface temperature of the shielding plugs can prevent the lowering of the heat insulation performance which will result in the increment of shielding plug cooling capacity, thereby improving reliability. In the meantime, since there is mounted an earthquake-resisting support, the thermal shield layer will move for a slight gap in case of an earthquake, being supported by the earthquake-resisting support, and the movement of the thermal shield layer is restricted, thereby maintaining integrity without increasing the stroke of the ring-like spring. (Kawakami, Y.)

  1. Evaluation of piping heat transfer, piping flow regimes, and steam generator heat transfer for the Semiscale Mod-1 isothermal tests

    International Nuclear Information System (INIS)

    French, R.T.

    1975-08-01

    Selected experimental data pertinent to piping heat transfer, transient fluid flow regimes, and steam generator heat transfer obtained during the Semiscale Mod-1 isothermal blowdown test series (Test Series 1) are analyzed. The tests in this first test series were designed to provide counterparts to the LOFT nonnuclear experiments. The data from the Semiscale Mod-1 intact and broken loop piping are evaluated to determine the surface heat flux and average heat transfer coefficients effective during the blowdown transient and compared with well known heat transfer correlations used in the RELAP4 computer program. Flow regimes in horizontal pipe sections are calculated and compared with data obtained from horizontal and vertical densitometers and with an existing steady state flow map. Effects of steam generator heat transfer are evaluated quantitatively and qualitatively. The Semiscale Mod-1 data and the analysis presented in this report are valuable for evaluating the adequacy and improving the predictive capability of analytical models developed to predict system response to piping heat transfer, piping flow regimes, and steam generator heat transfer during a postulated loss-of-coolant accident (LOCA) in a pressurized water reactor (PWR). 16 references. (auth)

  2. Experimental investigation on isothermal stratified flow mixing in a horizontal T-junction

    Energy Technology Data Exchange (ETDEWEB)

    Isaev, Alexander; Kulenovic, Rudi; Laurien, Eckart [Stuttgart Univ. (Germany). Inst. fuer Kernenergetik und Energiesysteme (IKE)

    2016-10-15

    Turbulent and stratified flows can lead to thermal fatigue in piping systems of nuclear power plants (NPP). Such flows can be investigated in the University of Stuttgart Fluid-Structure-Interaction (FSI) facility with a T-Junction at thermal conditions with temperature differences of up to 255 K and at pressures of maximum 75 bars.

  3. Effects of rotation on MHD flow past an accelerated isothermal vertical plate with heat and mass diffusion

    Directory of Open Access Journals (Sweden)

    Muthucumaraswamy R.

    2010-01-01

    Full Text Available An exact analysis of rotation effects on unsteady flow of an incompressible and electrically conducting fluid past a uniformly accelerated infinite isothermal vertical plate, under the action of transversely applied magnetic field has been presented. The plate temperature is raised to Tw and the concentration level near the plate is also raised to C′w . The dimensionless governing equations are solved using Laplace-transform technique. The velocity profiles, temperature and concentration are studied for different physical parameters like thermal Grashof number, mass Grashof number, Schmidt number, Prandtl number and time. It is observed that the velocity increases with increasing values of thermal Grashof number or mass Grashof number. It is also observed that the velocity increases with decreasing magnetic field parameter.

  4. A two-phase flow and non-isothermal agglomerate model for a proton exchange membrane (PEM) fuel cell

    International Nuclear Information System (INIS)

    Xing, Lei; Liu, Xiaoteng; Alaje, Taiwo; Kumar, Ravi; Mamlouk, Mohamed; Scott, Keith

    2014-01-01

    A two dimensional, across the channel, steady-state model for a proton exchange membrane fuel cell (PEMFC) is presented in which the non-isothermal model for temperature distribution, the two-phase flow model for liquid water transport and the agglomerate model for oxygen reduction reaction are fully coupled. This model is used to investigate thermal transport within the membrane electrode assembly (MEA) associated with the combinational water phase-transfer and transport mechanisms. Effective temperature distribution strategies are established aim to enhance the cell performance. Agglomerate assumption is adopted in which the ionomer and liquid water in turn cover the agglomerate to form the ionomer and liquid water films. Ionomer swelling is associated with the non-uniform distribution of the water content. The modelling results show that heat accumulates within the cathode catalyst layer under the channel. Higher operating temperature improves the cell performance by increasing the kinetics, reducing the liquid water saturation on the cathode and increasing the water carrying capacity of the anode gas. Applying higher temperature on the anode and enlarging the width ratio of the channel/rib could improve the cell performance. Higher cathode temperature decreases the oxygen mole fraction, resulting in an insufficient oxygen supply and a limitation of the cell performance. - Highlights: • The two-phase flow and non-isothermal model couple with the agglomerate model. • Oxygen diffusivity and solubility in Nafion ® relate to water content and temperature. • Higher anode operating temperature improves the fuel cell performance. • Insufficient oxygen supply limits cell performance at higher current densities

  5. Modelling and Simulation of Structural Deformation of Isothermal Subsurface Flow and Carbon Dioxide Injection

    KAUST Repository

    El-Amin, Mohamed; Negara, Ardiansyah; Salama, Amgad; Sun, Shuyu

    2011-01-01

    force term. The flux continuity condition is used at interfaces between different permeability layers of the heterogeneous medium. We analyze the vertical migration of a CO2 plume injected into a 2D layered reservoir. Analysis of distribution of flow

  6. [Effect of different sludge retention time (SRT) on municipal sewage sludge bioleaching continuous plug flow reaction system].

    Science.gov (United States)

    Liu, Fen-Wu; Zhou, Li-Xiang; Zhou, Jun; Jiang, Feng; Wang, Dian-Zhan

    2012-01-01

    A plug-flow bio-reactor of 700 L working volume for sludge bioleaching was used in this study. The reactor was divided into six sections along the direction of the sludge movement. Fourteen days of continuous operation of sludge bioleaching with different sludge retention time (SRT) under the condition of 1.2 m3 x h(-1) aeration amount and 4 g x L(-1) of microbial nutritional substance was conducted. During sludge bioleaching, the dynamic changes of pH, DO, dewaterability (specific resistance to filtration, SRF) of sewage sludge in different sections were investigated in the present study. The results showed that sludge pH were maintained at 5.00, 3.00, 2.90, 2.70, 2.60 and 2.40 from section 1 to section 6 and the SRF of sludge was drastically decreased from initial 0.64 x 10(13) m x kg(-1) to the final 0.33 x 10(13) m x kg(-1) when bioleaching system reached stable at hour 72 with SRT 2.5d. In addition, the sludge pH were maintained at 5.10, 4.10, 3.20, 2.90, 2.70 and 2.60, the DO value were 0.43, 1.47, 3.29, 4.76, 5.75 and 5.88 mg x L(-1) from section 1 to section 6, and the SRF of sludge was drastically decreased from initial 0.56 x 10(13) to the final 0.20 x 10(13) m x kg(-1) when bioleaching system reached stable at hour 120 with SRT 2 d. The pH value was increased to 3.00 at section 6 at hour 48 h with SRT 1.25 d. The bioleaching system imbalanced in this operation conditions because of the utilization efficiency of microbial nutritional substance by Acidibacillus spp. was decreased. The longer sludge retention time, the easier bioleaching system reached stable. 2 d could be used as the optimum sludge retention time in engineering application. The bioleached sludge was collected and dewatered by plate-and-frame filter press to the moisture content of dewatered sludge cake under 60%. This study would provide the necessary data to the engineering application on municipal sewage sludge bioleaching.

  7. Analytic solutions to linear, time-dependent fission product deposition models for isothermal laminar, slug, or multiregion flow conditions

    International Nuclear Information System (INIS)

    Durkee, J.W. Jr.

    1983-01-01

    The time-dependent convective-diffusion equation with radioactive decay is solved analytically in axisymmetric cylindrical geometry for laminar and slug velocity profiles under isothermal conditions. Concentration dependent diffusion is neglected. The laminar flow solution is derived using the method of separation of variables and Frobenius' technique for constructing a series expansion about a regular singular point. The slug flow multiregion solution is obtained using the method of separation of variables. The Davidon Variable Metric Minimization algorithm is used to compute the coupling coefficients. These solutions, which describe the transport of fission products in a flowing stream, are then used to determine the concentration of radioactive material deposited on a conduit wall using a standard mass transfer model. Fission product deposition measurements for five diffusion tubes in a Fort St. Vrain High-Temperature Gas-Cooled reactor plateout probe are analyzed. Using single region slug and laminar models, the wall mass transfer coefficients, diffusion coefficients, and inlet concentrations are determined using least squares analysis. The diffusion coefficients and inlet concentrations are consistent between tubes. The derived diffusion coefficients and wall mass transfer coefficients are in relative agreement with known literature values

  8. Air Distribution in Rooms with Ceiling-mounted Obstacles and Three-Dimensional Isothermal Flow

    DEFF Research Database (Denmark)

    Nielsen, Peter V.; Evensen, Louis; Grabau, Peter

    The air supply openings in ventilated rooms are often placed close to the ceiling. A recirculating flow is generated in the room, and the region between the ceiling and the occupied zone serves as an entrainment and velocity decay area for the wall jets. Ceiling-mounted obstacles may disturb...

  9. TOUGHREACT Version 2.0: A simulator for subsurface reactive transport under non-isothermal multiphase flow conditions

    Energy Technology Data Exchange (ETDEWEB)

    Xu, T.; Spycher, N.; Sonnenthal, E.; Zhang, G.; Zheng, L.; Pruess, K.

    2010-08-01

    TOUGHREACT is a numerical simulation program for chemically reactive non-isothermal flows of multiphase fluids in porous and fractured media, and was developed by introducing reactive chemistry into the multiphase fluid and heat flow simulator TOUGH2 V2. The first version of TOUGHREACT was released to the public through the U.S. Department of Energy's Energy Science and Technology Software Center (ESTSC) in August 2004. It is among the most frequently requested of ESTSC's codes. The code has been widely used for studies in CO{sub 2} geological sequestration, nuclear waste isolation, geothermal energy development, environmental remediation, and increasingly for petroleum applications. Over the past several years, many new capabilities have been developed, which were incorporated into Version 2 of TOUGHREACT. Major additions and improvements in Version 2 are discussed here, and two application examples are presented: (1) long-term fate of injected CO{sub 2} in a storage reservoir and (2) biogeochemical cycling of metals in mining-impacted lake sediments.

  10. Propagation of a cylindrical shock wave in a rotational axisymmetric isothermal flow of a non-ideal gas in magnetogasdynamics

    Directory of Open Access Journals (Sweden)

    G. Nath

    2012-12-01

    Full Text Available Self-similar solutions are obtained for unsteady, one-dimensional isothermal flow behind a shock wave in a rotational axisymmetric non-ideal gas in the presence of an azimuthal magnetic field. The shock wave is driven out by a piston moving with time according to power law. The fluid velocities and the azimuthal magnetic field in the ambient medium are assumed to be varying and obeying a power law. The density of the ambient medium is assumed to be constant. The gas is assumed to be non-ideal having infinite electrical conductivity and the angular velocity of the ambient medium is assumed to be decreasing as the distance from the axis increases. It is expected that such an angular velocity may occur in the atmospheres of rotating planets and stars. The effects of the non-idealness of the gas and the Alfven-Mach number on the flow-field are obtained. It is shown that the presence of azimuthal magnetic field and the rotation of the medium has decaying effect on the shock wave. Also, a comparison is made between rotating and non-rotating cases.

  11. The flow behavior and constitutive equation in isothermal compression of FGH4096-GH4133B dual alloy

    International Nuclear Information System (INIS)

    Liu, Yanhui; Yao, Zekun; Ning, Yongquan; Nan, Yang; Guo, Hongzhen; Qin, Chun; Shi, Zhifeng

    2014-01-01

    Highlights: • Hot compression behaviors of the FGH4096-GH4133B dual alloy were investigated. • Constitutive equation also represented deformation behavior of a dual alloy. • The effects of deformation activation energy on the microstructures were discussed. • Constitutive equation represented an accurate and precise estimate of flow stress. - Abstract: The electron beam welding of superalloy FGH4096 and GH4133B was conducted, and the cylindrical compression specimens were machined from the central part of the electron beam weldments. Isothermal compression tests were carried out on electron beam weldments FGH4096-GH4133B alloy at the temperatures of 1020–11140 °C (the nominal γ′-transus temperature is about 1080 °C) and the strain rates of 0.001–1.0 s −1 with the height reduction of 50%. True stress–true strain curves are sensitive to the deformation temperature and strain rate, and the flow stress decreases with the increasing deformation temperature and the decreasing strain rate. The true stress–true strain curves can indicate the intrinsic relationship between the flow stress and the thermal-dynamic behavior. The apparent activation energy of deformation at the strain of 0.6 was calculated to be 550 kJ/mol, and the apparent activation energy has a great effect on the microstructure. The constitutive equation that describes the flow stress as a function of strain rate and deformation temperature was proposed for modeling the hot deformation process of FGH4096-GH4133B electron beam weldments. The constitutive equation at the strain of 0.6 was established using the hyperbolic law. The relationship between the strain and the values of parameters was studied, and the cubic functions were built. The constitutive equation during the whole process can be obtained based on the parameters under different strains. Comparing the experimental flow stress and the calculated flow stress, the constitutive equation obtained in this paper can be very good

  12. Simulation and modeling of turbulent non isothermal vapor-droplet dispersed flow

    International Nuclear Information System (INIS)

    Baalbaki, Daoud

    2011-01-01

    One of the reference accident that may occur in PWR (Pressurized Water Reactor) is LOCA (Loss of Coolant Accident). The LOCA is studied to design some emergency systems implemented in the basic nuclear installations. The LOCA corresponds to the break of a pipe in the primary loop. This accident is associated with a loss of pressure which leads to the vaporization of the water in the reactor core and then to the rise of the temperature of the assemblies. In this study, we focus on the area of vapor-droplet flow, where the cooling effectiveness of such a mixture is a major concern. The droplets act as heat sinks for the vapor and control the vapor temperature profile which, in turn, determines the wall heat transfer rate. Our general objective is to ameliorate the modeling of the vapor-droplet flow (i.e. at CFD scale). Particularly the estimation of the radial distribution of the droplets. The volume fraction distribution of the two phases depends on the size and dispersion of the droplets in the flow. The size of the droplets is controlled by the rupture and coalescence mechanisms and the interfacial mass transfer (evaporation/condensation). The distribution of the droplets is controlled by the transfer of momentum between the two phases. Our study focuses particularly on the latter point. We are restricted to flows where the liquid water flows under the form of non-deformable spherical droplets that do not interact with each other. Both phases are treated by a two-fluid approach Euler-Euler. In chapter 2, a description of two-phase flow model is presented, using separate mass, momentum, and energy equations for the two phases. These separate balance equations are obtained in an averaging process starting from the local instantaneous conservation equations of the individual phases. During the averaging process, important information on local flow processes are lost and, consequently, additional correlations are needed in order to close the system of equations. The

  13. Modelling and Simulation of Structural Deformation of Isothermal Subsurface Flow and Carbon Dioxide Injection

    KAUST Repository

    El-Amin, Mohamed

    2011-05-15

    Injection of CO2 in hydrocarbon reservoir has double benefit. On the one hand, it is a profitable method due to issues related to global warming, and on the other hand it is an effective mechanism to enhance hydrocarbon recovery. Such injection associates complex processes involving, e.g., solute transport of dissolved materials, in addition to local changes in density of the phases. Also, increasing carbon dioxide injection may cause a structural deformation of the medium, so it is important to include such effect into the model. The structural deformation modelling in carbon sequestration is important to evaluate the medium stability to avoid CO2 leakage to the atmosphere. On the other hand, geologic formation of the medium is usually heterogeneous and consists of several layers of different permeability. In this work we conduct numerical simulation of two-phase flow in a heterogeneous porous medium domain with dissolved solute transport as well as structural deformation effects. The solute transport of the dissolved component is described by concentration equation. The structural deformation for geomechanics is derived from a general local differential balance equation with neglecting the local mass balance of solid phase and the inertial force term. The flux continuity condition is used at interfaces between different permeability layers of the heterogeneous medium. We analyze the vertical migration of a CO2 plume injected into a 2D layered reservoir. Analysis of distribution of flow field components such as saturation, pressures, velocities, and CO2 concentration are presented.

  14. Numerical modelling of an isothermal flow in a mixing Tee using large eddy simulation

    International Nuclear Information System (INIS)

    Ndombo, Jean-Marc

    2013-01-01

    Thermal fatigue in Pressurized Water Reactor plants has been found to be very acute in some hot/cold Tee junction mixing zones (CIVAUX, 1998). Large Eddy Simulation (LES) can be used to capture the unsteadiness which is responsible for the large mechanical stresses associated with thermal fatigue. Firstly, we analyze some results obtained using the EDF R and D Code Saturne applied to the Vattenfall Tee junction benchmark (version 2006) and we look at the effect of including synthetic turbulence at the Tee junction pipe inlets. Then we analyze high-order turbulent statistics in the T-junction using LES, to gain a better understanding of the heat exchange near the junction walls. The configuration of the T-junction used is that of the MOTHER project. The bulk Reynolds number is 30,000. The study shows the structure of the mean flow, budgets of the kinetic energy, temperature variance and the thermal heat flux are made in the internal flow and near the walls. Two kinds of computations are made. One with an adiabatic condition and the other with a non adiabatic condition (steel walls). The EDF R and D Code Saturne is coupled with SYRTHES to analyze the temperature in the wall (SYRTHES is also developed by EDF R and D). (author)

  15. Achieve efficient nitrogen removal from real sewage in a plug-flow integrated fixed-film activated sludge (IFAS) reactor via partial nitritation/anammox pathway.

    Science.gov (United States)

    Yang, Yandong; Zhang, Liang; Cheng, Jun; Zhang, Shujun; Li, Baikun; Peng, Yongzhen

    2017-09-01

    This study tested the feasibility of plug-flow integrated fixed-film activated sludge (IFAS) reactor in applying sewage partial nitritation/anammox (PN/A) process. The IFAS reactor was fed with real pre-treated sewage (C/N ratio=1.3) and operated for 200days. High nitrogen removal efficiency of 82% was achieved with nitrogen removal rates of 0.097±0.019kgN/(m 3 ·d). Therefore, plug-flow IFAS reactor could be an alternative to applying sewage PN/A process. Besides, it was found that the stability of sewage PN/A process was significantly affected by residual ammonium. Nitrate accumulated in effluent and PN/A performance deteriorated when residual ammonium was below 1mg/L. On the contrary, long-term stable PN/A operation was achieved when residual ammonium was over 3mg/L. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Numerical modelling of isothermal gas-liquid two-phase bubbly flow in vertical pipes

    International Nuclear Information System (INIS)

    Yamoah, S.

    2014-07-01

    In order to qualify CFD codes for accurate numerical predictions of transient evolution of flow regimes in a vertical gas-liquid two-phase flow, suitable closure models are needed. The current study focuses on detailed numerical investigation of the interfacial driving force models and assessment of two population balance model approaches viz. the MUltiple-Size-Group (MUSIG) and one-group Interfacial Area Transport Equation (lATE) using the two-fluid modelling approach. Numerical predictions of five primitive variables: gas volume fraction, interfacial area concentration, Sauter mean bubble diameter, gas velocity and liquid velocity; have been validated against experimental data of Monros et al., (2013). Three specific objectives have been completed in this study. Firstly, under the assumption of mono-disperse bubbles, a consistent set of interfacial force models have been investigated. The effect of drag, lift, wall lubrication and turbulent dispersion forces has been assessed. New parameters have been introduced in the wall lubrication force models of Antal et al., (1991) and Frank et al., (2004, 2008) as well as implementing additional drag coefficient models using CFX Expression Language (CEl). The Tomiyama, (1998) lift coefficient model has been modified in this study. In general, the predictions from the sets of interfacial force models yielded satisfactory agreement with the experimental data. A set of Grace drag coefficient model, Tomiyama lift coefficient model, Antal wall force model, and Favre averaged turbulent dispersion force were found to provide the best agreement with the experimental data. Secondly, a model validation study to assess the performance of existing coalescence and breakup models of the MUSIG model in simulating bubbly flow in vertical configuration has been conducted. The breakup model of Luo and Svendsen, (1996) and coalescence model of Prince and Blanch, (1990) have been implemented. Detailed analysis has been performed for the wall

  17. MATHEMATICAL MODEL NON-ISOTHERMAL FLOW HIGHLY VISCOUS MEDIA CHANNELS MATRIX EXTRUDER

    Directory of Open Access Journals (Sweden)

    A. S. Sidorenko

    2015-01-01

    Full Text Available We consider a one-dimensional steady flow of highly viscous medium in a cylindrical channel with Dissipation and dependence of the viscosity on the temperature. It is assumed that a relatively small intervals of temperature variation of the dynamic viscosity with a sufficient degree of accuracy can be assumed to be linear. The model was based on the equations of hydrodynamics and the heat transfer fluid. In the task channel wall temperature is assumed constant. An approximate solution of the problem, according to which the distribution of velocity, pressure and temperature is sought in the form of an expansion in powers of the dimensionless transverse coordinates. A special case, when the ratio of the velocity distribution, pressure and temperature is allowed to restrict the number of terms in the expansion as follows: for speed - the first 3 to the pressure - the first two for the temperature - the first 5. The expressions to determine the temperature profile of the medium in the channel and characterization dissipative heating. To simulate the process of heat transfer highly viscous media developed a program for personal electronic computers. The calculation was performed using experimental research data melt flow grain mixture of buckwheat and soybeans for the load speed of 0.08 mm / s. The method of computer simulation carried out checks on the adequacy of the solutions to the real process of heat transfer. Analysis of the results indicates that for small values of the length of the channel influence dissipation function appears mainly at the wall. By increasing the reduced length of this phenomenon applies to all section of the channel. At high temperature profile along the channel length is determined entirely by dissipation. In the case of heat transfer due to frictional heat only, the form of curves of temperature distribution is a consequence of the interaction effects of heating due to viscous shear effects cooling by conduction. The

  18. Large scale organized motion in isothermal swirling flow through an axisymmetric dump combustor

    International Nuclear Information System (INIS)

    Daddis, E.D.; Lieber, B.B.; Nejad, A.S.; Ahmed, S.A.

    1990-01-01

    This paper reports on velocity measurements that were obtained in a model axisymmetric dump combustor which included a coaxial swirler by means of a two component laser Doppler velocimeter (LDV) at a Reynolds number of 125,000. The frequency spectrum of the velocity fluctuations is obtained via the Fast Fourier Transform (FFT). The velocity field downstream of the dump plane is characterized, in addition to background turbulence, by large scale organized structures which are manifested as sharp spikes of the spectrum at relatively low frequencies. The decomposition of velocity disturbances to background turbulence and large scale structures can then be achieved through spectral methods which include matched filters and spectral factorization. These methods are demonstrated here for axial velocity obtained one step height downstream of the dump plane. Subsequent analysis of the various velocity disturbances shows that large scale structures account for about 25% of the apparent normal stresses at this particular location. Naturally, large scale structures evolve spatially and their contribution to the apparent stress tensor may vary depending on the location in the flow field

  19. Natural Convection Flow of Fractional Nanofluids Over an Isothermal Vertical Plate with Thermal Radiation

    Directory of Open Access Journals (Sweden)

    Constantin Fetecau

    2017-03-01

    Full Text Available The studies of classical nanofluids are restricted to models described by partial differential equations of integer order, and the memory effects are ignored. Fractional nanofluids, modeled by differential equations with Caputo time derivatives, are able to describe the influence of memory on the nanofluid behavior. In the present paper, heat and mass transfer characteristics of two water-based fractional nanofluids, containing nanoparticles of CuO and Ag, over an infinite vertical plate with a uniform temperature and thermal radiation, are analytically and graphically studied. Closed form solutions are determined for the dimensionless temperature and velocity fields, and the corresponding Nusselt number and skin friction coefficient. These solutions, presented in equivalent forms in terms of the Wright function or its fractional derivatives, have also been reduced to the known solutions of ordinary nanofluids. The influence of the fractional parameter on the temperature, velocity, Nusselt number, and skin friction coefficient, is graphically underlined and discussed. The enhancement of heat transfer in the natural convection flows is lower for fractional nanofluids, in comparison to ordinary nanofluids. In both cases, the fluid temperature increases for increasing values of the nanoparticle volume fraction.

  20. Hydrodynamic boundary conditions for one-component liquid-gas flows on non-isothermal solid substrates

    KAUST Repository

    Xu, Xinpeng

    2012-01-01

    Recently, liquid-gas flows related to droplets, bubbles, and thin films on solid surfaces with thermal and wettability gradients have attracted widespread attention because of the many physical processes involved and their promising potential applications in biology, chemistry, and industry. Various new physical effects have been discovered at fluid-solid interfaces by experiments and molecular dynamics simulations, e.g., fluid velocity slip, temperature slip (Kapitza resistance), mechanical-thermal cross coupling, etc. There have been various models and theories proposed to explain these experimental and numerical observations. However, to the best of our knowledge,a continuum hydrodynamic model capable of predicting the temperature and velocity profiles of liquid-gas flows on non-isothermal, heterogeneous solid substrates is still absent. The purpose of this work is to construct a continuum model for simulating the liquid-gas flows on solid surfaces that are flat and rigid, and may involve wettability gradients and thermal gradients. This model is able to describe fluid velocity slip, temperature slip, and mechanical-thermal coupling that may occur at fluid-solid interfaces. For this purpose, we first employ the diffuse interface modeling to formulate the hydrodynamic equations for one-component liquid-gas flows in the bulk region. This reproduces the dynamic van der Waals theory of Onuki [Phys. Rev. Lett., 94: 054501, 2005]. We then extendWaldmann\\'s method [Z. Naturforsch. A, 22: 1269-1280, 1967] to formulate the boundary conditions at the fluid-solid interface that match the hydrodynamic equations in the bulk. The effects of the solid surface curvature are also briefly discussed in the appendix. The guiding principles of our model derivation are the conservation laws and the positive definiteness of entropy production together with the Onsager reciprocal relation. The derived model is self-consistent in the sense that the boundary conditions are

  1. Parallel numerical modeling of hybrid-dimensional compositional non-isothermal Darcy flows in fractured porous media

    Science.gov (United States)

    Xing, F.; Masson, R.; Lopez, S.

    2017-09-01

    This paper introduces a new discrete fracture model accounting for non-isothermal compositional multiphase Darcy flows and complex networks of fractures with intersecting, immersed and non-immersed fractures. The so called hybrid-dimensional model using a 2D model in the fractures coupled with a 3D model in the matrix is first derived rigorously starting from the equi-dimensional matrix fracture model. Then, it is discretized using a fully implicit time integration combined with the Vertex Approximate Gradient (VAG) finite volume scheme which is adapted to polyhedral meshes and anisotropic heterogeneous media. The fully coupled systems are assembled and solved in parallel using the Single Program Multiple Data (SPMD) paradigm with one layer of ghost cells. This strategy allows for a local assembly of the discrete systems. An efficient preconditioner is implemented to solve the linear systems at each time step and each Newton type iteration of the simulation. The numerical efficiency of our approach is assessed on different meshes, fracture networks, and physical settings in terms of parallel scalability, nonlinear convergence and linear convergence.

  2. Attempts to isolate a horizontal high diameter (300 mm nominal diameter) pipeline with an ice plug at minimum water flow and without water flow

    International Nuclear Information System (INIS)

    Corbescu, B.; Gyongyosi, T.; Puiu, D.; Panaitescu, V. N.

    2016-01-01

    The ice plug isolation technique used for high diameter horizontal pipes is used for repair and maintenance activities on hydraulic installations that use liquid working agents. These techniques do not require shutting down the entire plant. The ice plug development inside the pipe requires using custom specialized equipment for each individual application. This paper briefly describes the experimental technological facilities used for conducting the experiments and highlights the important aspects in an experiment conducted on a horizontal NPS 12 testing section running demineralized water followed by the result analysis and conclusions. The paper is dedicated to specialists working in research and technological engineering. (authors)

  3. Dual continuum models of fully coupled non-isothermal multiphase flow and reactive transport in porous media

    International Nuclear Information System (INIS)

    Zheng, L.; Samper, J.

    2005-01-01

    Full text of publication follows: Double porosity, double permeability and dual continuum models (DCM) are widely used for modeling preferential water flow and mass transport in unsaturated and fractured media. Here we present a DCM of fully coupled non-isothermal multiphase flow and reactive transport model for the FEBEX compacted bentonite, a material which exhibits a double porosity behavior.. FEBEX (Full-scale Engineered Barrier EXperiment) is a demonstration and research project dealing with the bentonite engineered barrier designed for sealing and containment of a high level radioactive waste repository. Our DCM considers inter-aggregate macro-pores, and intra-aggregate and interlayer micro-pores. Two types of DCMs are tested: the dual continuum connected matrix (DCCM) and the dual continuum dis connected matrix (DCDM). Liquid flow in macro-pores is described with a mass conservation equation accounting for Darcian flow, chemical and thermal osmosis. In DCCM, water flux in micropores is calculated with a modified Darcy's law by adding a chemical osmosis term. A simple mass balance equation is used for DCDM which contains a storage and a water exchange term for water in micropores. A mixed type of water exchange term is adopted which includes a second order term accounting for water transfer due to the difference in liquid pressure and a first order term accounting for the gradient in chemical osmosis pressure. Equations of mass conservation for liquid, gas and heat in macro-pores and liquid mass conservation in micropores are solved by using a Newton-Raphson method. Two transport equations with a coupling interaction term are used to describe solute transport in macro- and micro-pores. The coupling term contains a first order diffusion term and a convection term (solute exchange due to water exchange). Transport equations as well as chemical reactions in the two domains are solved by means of a sequential iteration method. All these feature have been

  4. Flow of magnetic particles in blood with isothermal heating: A fractional model for two-phase flow

    Science.gov (United States)

    Ali, Farhad; Imtiaz, Anees; Khan, Ilyas; Sheikh, Nadeem Ahmad

    2018-06-01

    In the sixteenth century, medical specialists were of the conclusion that magnet can be utilized for the treatment or wipe out the illnesses from the body. On this basis, the research on magnet advances day by day for the treatment of different types of diseases in mankind. This study aims to investigate the effect of magnetic field and their applications in human body specifically in blood. Blood is a non-Newtonian fluid because its viscosity depends strongly on the fraction of volume occupied by red cells also called the hematocrit. Therefore, in this paper blood is considered as an example of non-Newtonian Casson fluid. The blood flow is considered in a vertical cylinder together with heat transfer due to mixed conviction caused by buoyancy force and the external pressure gradient. Effect of magnetic field on the velocities of blood and magnetic particles is also considered. The problem is modelled using the Caputo-Fabrizio derivative approach. The governing fractional partial differential equations are solved using Laplace and Hankel transformation techniques and exact solutions are obtained. Effects of different parameters such as Grashof number, Prandtl number, Casson fluid parameter and fractional parameters, and magnetic field are shown graphically. Both velocity profiles increase with the increase of Grashoff number and Casson fluid parameter and reduce with the increase of magnetic field.

  5. A facile and efficient method of enzyme immobilization on silica particles via Michael acceptor film coatings: immobilized catalase in a plug flow reactor.

    Science.gov (United States)

    Bayramoglu, Gulay; Arica, M Yakup; Genc, Aysenur; Ozalp, V Cengiz; Ince, Ahmet; Bicak, Niyazi

    2016-06-01

    A novel method was developed for facile immobilization of enzymes on silica surfaces. Herein, we describe a single-step strategy for generating of reactive double bonds capable of Michael addition on the surfaces of silica particles. This method was based on reactive thin film generation on the surfaces by heating of impregnated self-curable polymer, alpha-morpholine substituted poly(vinyl methyl ketone) p(VMK). The generated double bonds were demonstrated to be an efficient way for rapid incorporation of enzymes via Michael addition. Catalase was used as model enzyme in order to test the effect of immobilization methodology by the reactive film surface through Michael addition reaction. Finally, a plug flow type immobilized enzyme reactor was employed to estimate decomposition rate of hydrogen peroxide. The highly stable enzyme reactor could operate continuously for 120 h at 30 °C with only a loss of about 36 % of its initial activity.

  6. Complete nitrogen removal from municipal wastewater via partial nitrification by appropriately alternating anoxic/aerobic conditions in a continuous plug-flow step feed process.

    Science.gov (United States)

    Ge, Shijian; Peng, Yongzhen; Qiu, Shuang; Zhu, Ao; Ren, Nanqi

    2014-05-15

    This study assessed the technical feasibility of removing nitrogen from municipal wastewater by partial nitrification (nitritation) in a continuous plug-flow step feed process. Nitrite in the effluent accumulated to over 81.5  ± 9.2% but disappeared with the transition of process operation from anoxic/oxic mode to the anaerobic/anoxic/oxic mode. Batch tests showed obvious ammonia oxidizing bacteria (AOB) stimulation (advanced ammonia oxidation rate) and nitrite (NOB) oxidizing bacteria inhibition (reduced nitrite oxidation rate) under transient anoxic conditions. Two main factors contributed to nitritation in this continuous plug-flow process: One was the alternating anoxic and oxic operational condition; the step feed strategy guaranteed timely denitrification in anoxic zones, allowing a reduction in energy supply (nitrite) to NOB. Fluorescence in Situ Hybridization and quantitative real-time polymerase chain reaction analysis indicated that NOB population gradually decreased to 1.0  ± 0.1% of the total bacterial population (dominant Nitrospira spp., 1.55 × 10(9) copies/L) while AOB increased approximately two-fold (7.4  ± 0.9%, 1.25 × 10(10) copies/L) during the above anoxic to anaerobic transition. Most importantly, without addition of external carbon sources, the above wastewater treatment process reached 86.0  ± 4.2% of total nitrogen (TN) removal with only 7.23 ± 2.31 mg/L of TN in the effluent, which met the discharge requirements. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. The effect of fluid flow due to the crystal-melt density change on the growth of a parabolic isothermal dendrite

    Science.gov (United States)

    Mcfadden, G. B.; Coriell, S. R.

    1986-01-01

    The Ivantsov (1947) analysis of an isolated isothermal dendrite (with zero surface tension) growing into a supercooled liquid is extended to include the effects of the fluid flow due to volume contraction or expansion upon solidification. For an axisymmetric paraboloidal dendrite, an analytic solution to the Navier-Stokes equations is obtained. The magnitude of the flow is proportional to the relative density change epsilon, and the flow becomes negligible far from the surface of the dendrite. The temperature field consistent with this flow can also be found explicitly. The well-known expression that relates the dimensionless supercooling to the Peclet number in the absence of fluid flow is modified for nonzero epsilon, but the effect is of order epsilon and hence is seen to be minor for most values of epsilon and dimensionless supercooling that occur in practice.

  8. Shielding plug device

    International Nuclear Information System (INIS)

    Orii, Shoichi; Hasegawa, Satoshi; Makishima, Kenji.

    1976-01-01

    Object: To reduce the size of and extend the life of a revolving bearing and facilitate the laying of driving cables and duct lines, this being accomplished by providing plug raising means of a fast breeder on a stationary plug mounting base so as to prevent the shearing force of sodium from acting upon the revolving bearing. Structure: The shield plug means comprises a stationary plug secured to the open end of the reactor container, a rotary plug rotatable with respect to the stationary plug, an annular base formed on top of the stationary plug so as to cover the rotary plug, a bearing secured to the rotary plug edge lower face and upper and lower locking plates. At the time of the rotation of the rotary plug, the upper locking plate is withdrawn, the stationary plug is raised to release the seal structure, and the lower locking plate is inserted between the bearing and stationary plug. In this way, smooth rotation of the rotary plug can be obtained. (Horiuchi, T.)

  9. Reactor vessel sealing plug

    International Nuclear Information System (INIS)

    Dooley, R.A.

    1986-01-01

    This invention relates to an apparatus and method for sealing the cold leg nozzles of a nuclear reactor pressure vessel from a remote location during maintenance and inspection of associated steam generators and pumps while the pressure vessel and refueling canal are filled with water. The apparatus includes a sealing plug for mechanically sealing the cold leg nozzle from the inside of a reactor pressure vessel. The sealing plugs include a primary and a secondary O-ring. An installation tool is suspended within the reactor vessel and carries the sealing plug. The tool telescopes to insert the sealing plug within the cold leg nozzle, and to subsequently remove the plug. Hydraulic means are used to activate the sealing plug, and support means serve to suspend the installation tool within the reactor vessel during installation and removal of the sealing plug

  10. A numerical study on the forced convection heat transfer from an isothermal and isoflux sphere in the steady symmetric flow regime

    Energy Technology Data Exchange (ETDEWEB)

    Dhole, S.D.; Chhabra, R.P. [Department of Chemical Engineering, Indian Institute of Technology, Kanpur 208 016 (India); Eswaran, V. [Department of Mechanical Engineering, Indian Institute of Technology, Kanpur 208 016 (India)

    2006-03-15

    The effects of Reynolds and Prandtl numbers on the heat transfer characteristics of an unconfined sphere for different thermal boundary conditions (isothermal and isoflux) on the sphere surface have been investigated numerically by using a finite volume method for the range of conditions as 5=flow regime. The variation of local Nusselt number on the sphere surface shows the effect of Prandtl number on heat transfer from a sphere in this flow regime. In addition, this work also demonstrates an approach to solve such flow problems using the Cartesian form of the field equations. (author)

  11. Analytical solutions for hydromagnetic natural convection flow of a particulate suspension through isoflux-isothermal channels in the presence of a heat source or sink

    International Nuclear Information System (INIS)

    Chamkha, Ali J.; Al-Rashidi, Seham S.

    2010-01-01

    This work considers the problem of steady natural convection hydromagnetic flow of a particulate suspension through an infinitely long channel in the presence of heat generation or absorption effects. The channel walls are maintained at isoflux-isothermal condition. That is, the thermal boundary conditions are such that one of the channel walls is maintained at constant heat flux while the other is maintained at a constant temperature. Various closed-form solutions of the governing equations for different special cases are obtained. A parametric study of the physical parameters involved in the problem is done to illustrate the influence of these parameters on the velocity and temperature profiles of both phases.

  12. Velocity of a single gas plug rising through a particle-gas-liquid three-phase flow (In the case that particles updrift in a stagnant liquid column)

    International Nuclear Information System (INIS)

    Koizumi, Yasuo; Shimada, Jun; Ohtake, Hiroyasu

    1999-01-01

    The velocity of a single air plug rising through a stagnant water column in a pipe with updrifting particles has been examined at atmospheric pressure and room temperature. The particles used were polymer balls with a diameter of 3.18 mm and a density of 0.835 x 10 -3 kg/m 3 . The water velocity in a film around the plug and a wake region behind the plug was measured by a laser Doppler velocimeter. The thickness of the film was also measured with a dye-fluoresce-method by a laser ray. When the updrifting particles were introduced, the rising velocity of the plug became fast a little. However, the velocity was considerably slower than that in the falling particle case and independent on the particle introduction rate. The film around the plug was thicker a little than that in the no particle case, however considerably thinner than that in the falling particle case. The water velocity in the film around the plug was slower a little than that in the no particle case, and not dependent on the particle introduction rate contrary to that in the falling particle case. The vortex size behind the plug was almost the same as that in the no particle case although the vortex region was spread downward in the falling particle case. (author)

  13. Tube plug removal machine

    International Nuclear Information System (INIS)

    Hawkins, P.J.

    1987-01-01

    In a nuclear steam generator wherein some faulty tubes have been isolated by mechanical plugging, to remove a selected plug without damaging the associated tube, a plug removal machine is used. The machine drills into a plug portion with a tap drill bit having a drill portion a tap portion and a threaded portion, engaging that plug portion with the threaded portion after the drilled hole has been threaded by the tap portion thereof, and removing a portion of the plug in the tube with a counterbore drill bit mounted concentrically about the tap drill bit. A trip pin and trip spline disengage the tap drill bit from the motor. The counterbore drill bit is thereafter self-centered with respect to the tube and plug about the now stationary tap drill bit. After a portion of the plug has been removed by the counterbore drill bit, pulling on the top drill bit by grippers on slots will remove the remaining plug portion from the tube. (author)

  14. Experimental and numerical investigation of the iso-thermal flow characteristics within a cylindrical chamber with multiple planar-symmetric impinging jets

    Science.gov (United States)

    Long, Shen; Lau, Timothy C. W.; Chinnici, Alfonso; Tian, Zhao Feng; Dally, Bassam B.; Nathan, Graham J.

    2017-10-01

    We present a joint experimental and numerical study of the flow structure within a cylindrical chamber generated by planar-symmetric isothermal jets, under conditions of relevance to a wide range of practical applications, including the Hybrid Solar Receiver Combustor (HSRC) technology. The HSRC features a cavity with a coverable aperture to allow it to be operated as either a combustion chamber or a solar receiver, with multiple burners to direct a flame into the chamber and a heat exchanger that absorbs the heat from both energy sources. In this study, we assess the cases of two or four inlet jets (simulating the burners), configured in a planar-symmetric arrangement and aligned at an angle to the axis (αj) over the range of 0°-90°, at a constant inlet Reynolds number of ReD = 10 500. The jets were positioned in the same axial plane near the throat and interact with each other and the cavity walls. Measurements obtained with particle image velocimetry were used together with numerical modeling employing Reynolds-averaged Navier-Stokes methods to characterize the large-scale flow field within selected configurations of the device. The results reveal a significant dependence of the mean flow-field on αj and the number of inlet jets (Nj). Four different flow regimes with key distinctive features were identified within the range of αj and Nj considered here. It was also found that αj has a controlling influence on the extent of back-flow through the throat, the turbulence intensity, the flow stability, and the dominant recirculation zone, while Nj has a secondary influence on the turbulence intensity, the flow stability, and the transition between each flow regime.

  15. Removable pipeline plug

    International Nuclear Information System (INIS)

    Vassalotti, M.; Anastasi, F.

    1984-01-01

    A removable plugging device for a pipeline, and particularly for pressure testing a steam pipeline in a boiling water reactor, wherein an inflatable annular sealing member seals off the pipeline and characterized by radially movable shoes for holding the plug in place, each shoe being pivotally mounted for self-adjusting engagement with even an out-of-round pipeline interior

  16. Retained Herrick Plug

    Directory of Open Access Journals (Sweden)

    Justin B. Hellman

    2018-05-01

    Full Text Available A 79-year-old female with a history of keratoconjunctivitis sicca presented with several years of epiphora of both eyes. Thirteen years earlier, intracanalicular Herrick lacrimal plugs (Lacrimedics, Eastsound, WA, USA had been placed in both eyes to treat her dry eye syndrome. After 13 years the patient felt the epiphora was intolerable and underwent endoscopic dacryocystorhinostomy (DCR of the left, then the right side. Intraoperatively, during the right endoscopic DCR, a Herrick lacrimal plug was found in the common canaliculus into the lacrimal sac. Postoperatively, the patient did well with improved epiphora. The Herrick plug is designed to be intracanalicular, and this case illustrates that the plug can migrate and be retained for many years. Collared punctal plugs have a lower risk of this type of complication.

  17. Heat transfer at microscopic level in a MHD fractional inertial flow confined between non-isothermal boundaries

    Science.gov (United States)

    Shoaib Anwar, Muhammad; Rasheed, Amer

    2017-07-01

    Heat transfer through a Forchheimer medium in an unsteady magnetohydrodynamic (MHD) developed differential-type fluid flow is analyzed numerically in this study. The boundary layer flow is modeled with the help of the fractional calculus approach. The fluid is confined between infinite parallel plates and flows by motion of the plates in their own plane. Both the plates have variable surface temperature. Governing partial differential equations with appropriate initial and boundary conditions are solved by employing a finite-difference scheme to discretize the fractional time derivative and finite-element discretization for spatial variables. Coefficients of skin friction and local Nusselt numbers are computed for the fractional model. The flow behavior is presented for various values of the involved parameters. The influence of different dimensionless numbers on skin friction and Nusselt number is discussed by tabular results. Forchheimer medium flows that involve catalytic converters and gas turbines can be modeled in a similar manner.

  18. The Microstructural Evolution and Special Flow Behavior of Ti-5Al-2Sn-2Zr-4Mo-4Cr During Isothermal Compression at a Low Strain Rate

    Science.gov (United States)

    Sun, J. Z.; Li, M. Q.; Li, H.

    2017-09-01

    The microstructural evolution and special flow behavior of Ti-5Al-2Sn-2Zr-4Mo-4Cr during isothermal compression at a strain rate of 0.0001 s-1 were investigated. The dislocation climbs in elongated α grains resulted in the formation of low-angle boundaries that transform into high-angle boundaries with greater deformation, and the elongated α grains subsequently separated into homogenous globular α grains with the penetration of the β phase. The simultaneous occurrence of discontinuous dynamic recrystallization and continuous dynamic recrystallization in the primary β grains resulted in a trimode grain distribution. The β grains surrounded by dislocations presented an equilateral-hexagonal morphology, which suggests that grain boundary sliding through dislocation climbs was the main deformation mechanism. The true stress-strain curves for 1073 and 1113 K abnormally intersect at a strain of 0.35, related to the α → β phase transformation and distinct growth of the β grain size.

  19. HEAT AND MASS TRANSFER EFFECTS ON FLOW PAST PARABOLIC STARTING MOTION OF ISOTHERMAL VERTICAL PLATE IN THE PRESENCE OF FIRST ORDER CHEMICAL REACTION

    Directory of Open Access Journals (Sweden)

    R. Muthucumaraswamy

    2013-06-01

    Full Text Available An exact solution of unsteady flow past a parabolic starting motion of the infinite isothermal vertical plate with uniform mass diffusion, in the presence of a homogeneous chemical reaction of the first order, has been studied. The plate temperature and the concentration level near the plate are raised uniformly. The dimensionless governing equations are solved using the Laplace transform technique. The effect of velocity profiles are studied for different physical parameters, such as chemical reaction parameter, thermal Grashof number, mass Grashof number, Schmidt number, and time. It is observed that velocity increases with increasing values of thermal Grashof number or mass Grashof number. The trend is reversed with respect to the chemical reaction parameter.

  20. Plug Load Data

    Data.gov (United States)

    National Aeronautics and Space Administration — We provide MATLAB binary files (.mat) and comma separated values files of data collected from a pilot study of a plug load management system that allows for the...

  1. Challenging and improving conceptual models for isothermal flow in unsaturated, fractured rock through exploration of small-scale processes

    International Nuclear Information System (INIS)

    Glass, R.J.; Nicholl, M.J.; Tidwell, V.C.

    1996-01-01

    Over the past several years, the authors have performed experimental studies focused on understanding small-scale flow processes within discrete fractures and individual matrix blocks; much of the understanding gained in that time differs from that underlying the basic assumptions used in effective media representations. Here they synthesize the process level understanding gained from their laboratory studies to explore how such small-scale processes may influence the behavior of fluid flow in fracture networks and ensembles of matrix blocks at levels sufficient to impact the formulation of intermediate-scale effective media properties. They also explore, by means of a thought experiment, how these same small-scale processes could couple to produce a large-scale system response inconsistent with current conceptual models based on continuum representations of flow through unsaturated, fractured rock. Based on their findings, a number of modifications to existing dual permeability models are suggested that should allow them improved applicability; however, even with these modifications, it is likely that continuum representations of flow through unsaturated fractured rock will have limited validity and must therefore be applied with caution

  2. Biomass plug development and propagation in porous media.

    Science.gov (United States)

    Stewart, T L; Fogler, H S

    2001-02-05

    Exopolymer-producing bacteria can be used to modify soil profiles for enhanced oil recovery or bioremediation. Understanding the mechanisms associated with biomass plug development and propagation is needed for successful application of this technology. These mechanisms were determined from packed-bed and micromodel experiments that simulate plugging in porous media. Leuconostoc mesenteroides was used, because production of dextran, a water-insoluble exopolymer, can be controlled by using different carbon sources. As dextran was produced, the pressure drop across the porous media increased and began to oscillate. Three pressure phases were identified under exopolymer-producing conditions: the exopolymer-induction phase, the plugging phase, and the plug-propagation phase. The exopolymer-induction phase extended from the time that exopolymer-producing conditions were induced until there was a measurable increase in pressure drop across the porous media. The plugging phase extended from the first increase in pressure drop until a maximum pressure drop was reached. Changes in pressure drop in these two phases were directly related to biomass distribution. Specifically, flow channels within the porous media filled with biomass creating a plugged region where convective flow occurred only in water channels within the biofilm. These water channels were more restrictive to flow causing the pressure drop to increase. At a maximum pressure drop across the porous media, the biomass yielded much like a Bingham plastic, and a flow channel was formed. This behavior marked the onset of the plug-propagation phase which was characterized by sequential development and breakthrough of biomass plugs. This development and breakthrough propagated the biomass plug in the direction of nutrient flow. The dominant mechanism associated with all three phases of plugging in porous media was exopolymer production; yield stress is an additional mechanism in the plug-propagation phase. Copyright

  3. PLUGGING AND UNPLUGGING OF WASTE TRANSFER PIPELINES

    International Nuclear Information System (INIS)

    Ebadian, M.A.

    1999-01-01

    This project, which began in FY97, involves both the flow loop research on plugging and unplugging of waste transfer pipelines, and the large-scale industrial equipment test of plugging locating and unplugging technologies. In FY98, the related work was performed under the project name ''Mixing, Settling, and Pipe Unplugging of Waste Transfer Lines.'' The mixing, settling, and pipeline plugging and unplugging are critical to the design and maintenance of a waste transfer pipeline system, especially for the High-Level Waste (HLW) pipeline transfer. The major objective of this work is to recreate pipeline plugging conditions for equipment testing of plug locating and removal and to provide systematic operating data for modification of equipment design and enhancement of performance of waste transfer lines used at DOE sites. As the waste tank clean-out and decommissioning program becomes active at the DOE sites, there is an increasing potential that the waste slurry transfer lines will become plugged and unable to transport waste slurry from one tank to another or from the mixing tank to processing facilities. Transfer systems may potentially become plugged if the solids concentration of the material being transferred increases beyond the capability of the prime mover or if upstream mixing is inadequately performed. Plugging can occur due to the solids' settling in either the mixing tank, the pumping system, or the transfer lines. In order to enhance and optimize the slurry's removal and transfer, refined and reliable data on the mixing, sampling, and pipe unplugging systems must be obtained based on both laboratory-scale and simulated in-situ operating conditions

  4. Development of multiplex loop mediated isothermal amplification (m-LAMP) label-based gold nanoparticles lateral flow dipstick biosensor for detection of pathogenic Leptospira.

    Science.gov (United States)

    Nurul Najian, A B; Engku Nur Syafirah, E A R; Ismail, Nabilah; Mohamed, Maizan; Yean, Chan Yean

    2016-01-15

    In recent years extensive numbers of molecular diagnostic methods have been developed to meet the need of point-of-care devices. Efforts have been made towards producing rapid, simple and inexpensive DNA tests, especially in the diagnostics field. We report on the development of a label-based lateral flow dipstick for the rapid and simple detection of multiplex loop-mediated isothermal amplification (m-LAMP) amplicons. A label-based m-LAMP lateral flow dipstick assay was developed for the simultaneous detection of target DNA template and a LAMP internal control. This biosensor operates through a label based system, in which probe-hybridization and the additional incubation step are eliminated. We demonstrated this m-LAMP assay by detecting pathogenic Leptospira, which causes the re-emerging disease Leptospirosis. The lateral flow dipstick was developed to detect of three targets, the LAMP target amplicon, the LAMP internal control amplicon and a chromatography control. Three lines appeared on the dipstick, indicating positive results for all representative pathogenic Leptospira species, whereas two lines appeared, indicating negative results, for other bacterial species. The specificity of this biosensor assay was 100% when it was tested with 13 representative pathogenic Leptospira species, 2 intermediate Leptospira species, 1 non-pathogenic Leptospira species and 28 other bacteria species. This study found that this DNA biosensor was able to detect DNA at concentrations as low as 3.95 × 10(-1) genomic equivalent ml(-1). An integrated m-LAMP and label-based lateral flow dipstick was successfully developed, promising simple and rapid visual detection in clinical diagnostics and serving as a point-of-care device. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Core2D. A code for non-isothermal water flow and reactive solute transport. Users manual version 2

    International Nuclear Information System (INIS)

    Samper, J.; Juncosa, R.; Delgado, J.; Montenegro, L.

    2000-01-01

    Understanding natural groundwater quality patterns, quantifying groundwater pollution and assessing the effects of waste disposal, require modeling tools accounting for water flow, and transport of heat and dissolved species as well as their complex interactions with solid and gases phases. This report contains the users manual of CORE ''2D Version V.2.0, a COde for modeling water flow (saturated and unsaturated), heat transport and multicomponent Reactive solute transport under both local chemical equilibrium and kinetic conditions. it is an updated and improved version of CORE-LE-2D V0 (Samper et al., 1988) which in turns is an extended version of TRANQUI, a previous reactive transport code (ENRESA, 1995). All these codes were developed within the context of Research Projects funded by ENRESA and the European Commission. (Author)

  6. Core 2D. A code for non-isothermal water flow and reactive solute transport. Users manual version 2

    Energy Technology Data Exchange (ETDEWEB)

    Samper, J; Juncosa, R; Delgado, J; Montenegro, L [Universidad de A Coruna (Spain)

    2000-07-01

    Understanding natural groundwater quality patterns, quantifying groundwater pollution and assessing the effects of waste disposal, require modeling tools accounting for water flow, and transport of heat and dissolved species as well as their complex interactions with solid and gases phases. This report contains the users manual of CORE ''2D Version V.2.0, a COde for modeling water flow (saturated and unsaturated), heat transport and multicomponent Reactive solute transport under both local chemical equilibrium and kinetic conditions. it is an updated and improved version of CORE-LE-2D V0 (Samper et al., 1988) which in turns is an extended version of TRANQUI, a previous reactive transport code (ENRESA, 1995). All these codes were developed within the context of Research Projects funded by ENRESA and the European Commission. (Author)

  7. Core 2D. A code for non-isothermal water flow and reactive solute transport. Users manual version 2

    Energy Technology Data Exchange (ETDEWEB)

    Samper, J.; Juncosa, R.; Delgado, J.; Montenegro, L. [Universidad de A Coruna (Spain)

    2000-07-01

    Understanding natural groundwater quality patterns, quantifying groundwater pollution and assessing the effects of waste disposal, require modeling tools accounting for water flow, and transport of heat and dissolved species as well as their complex interactions with solid and gases phases. This report contains the users manual of CORE ''2D Version V.2.0, a COde for modeling water flow (saturated and unsaturated), heat transport and multicomponent Reactive solute transport under both local chemical equilibrium and kinetic conditions. it is an updated and improved version of CORE-LE-2D V0 (Samper et al., 1988) which in turns is an extended version of TRANQUI, a previous reactive transport code (ENRESA, 1995). All these codes were developed within the context of Research Projects funded by ENRESA and the European Commission. (Author)

  8. Development of multiplex loop mediated isothermal amplification (m-LAMP) label-based gold nanoparticles lateral flow dipstick biosensor for detection of pathogenic Leptospira

    International Nuclear Information System (INIS)

    Nurul Najian, A.B.; Engku Nur Syafirah, E.A.R.; Ismail, Nabilah; Mohamed, Maizan; Yean, Chan Yean

    2016-01-01

    In recent years extensive numbers of molecular diagnostic methods have been developed to meet the need of point-of-care devices. Efforts have been made towards producing rapid, simple and inexpensive DNA tests, especially in the diagnostics field. We report on the development of a label-based lateral flow dipstick for the rapid and simple detection of multiplex loop-mediated isothermal amplification (m-LAMP) amplicons. A label-based m-LAMP lateral flow dipstick assay was developed for the simultaneous detection of target DNA template and a LAMP internal control. This biosensor operates through a label based system, in which probe-hybridization and the additional incubation step are eliminated. We demonstrated this m-LAMP assay by detecting pathogenic Leptospira, which causes the re-emerging disease Leptospirosis. The lateral flow dipstick was developed to detect of three targets, the LAMP target amplicon, the LAMP internal control amplicon and a chromatography control. Three lines appeared on the dipstick, indicating positive results for all representative pathogenic Leptospira species, whereas two lines appeared, indicating negative results, for other bacterial species. The specificity of this biosensor assay was 100% when it was tested with 13 representative pathogenic Leptospira species, 2 intermediate Leptospira species, 1 non-pathogenic Leptospira species and 28 other bacteria species. This study found that this DNA biosensor was able to detect DNA at concentrations as low as 3.95 × 10 −1 genomic equivalent ml −1 . An integrated m-LAMP and label-based lateral flow dipstick was successfully developed, promising simple and rapid visual detection in clinical diagnostics and serving as a point-of-care device. - Highlights: • We develop multiplex LAMP label-based lateral flow dipstick biosensor for detection of pathogenic Leptospira. • We design primers for multiplex LAMP targeting the conserved LipL32 gene of pathogenic Leptospira and LAMP internal

  9. Development of multiplex loop mediated isothermal amplification (m-LAMP) label-based gold nanoparticles lateral flow dipstick biosensor for detection of pathogenic Leptospira

    Energy Technology Data Exchange (ETDEWEB)

    Nurul Najian, A.B.; Engku Nur Syafirah, E.A.R.; Ismail, Nabilah [Department of Medical Microbiology & Parasitology, School of Medical Sciences, Health Campus, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan (Malaysia); Mohamed, Maizan [Faculty of Veterinary Medicine, Universiti Malaysia Kelantan, City Campus, Pengkalan Chepa, Locked Bag 36, 16100 Kota Bharu, Kelantan (Malaysia); Yean, Chan Yean, E-mail: yeancyn@yahoo.com [Department of Medical Microbiology & Parasitology, School of Medical Sciences, Health Campus, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan (Malaysia); Institute for Research in Molecular Medicine (INFORMM), Health Campus, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan (Malaysia)

    2016-01-15

    In recent years extensive numbers of molecular diagnostic methods have been developed to meet the need of point-of-care devices. Efforts have been made towards producing rapid, simple and inexpensive DNA tests, especially in the diagnostics field. We report on the development of a label-based lateral flow dipstick for the rapid and simple detection of multiplex loop-mediated isothermal amplification (m-LAMP) amplicons. A label-based m-LAMP lateral flow dipstick assay was developed for the simultaneous detection of target DNA template and a LAMP internal control. This biosensor operates through a label based system, in which probe-hybridization and the additional incubation step are eliminated. We demonstrated this m-LAMP assay by detecting pathogenic Leptospira, which causes the re-emerging disease Leptospirosis. The lateral flow dipstick was developed to detect of three targets, the LAMP target amplicon, the LAMP internal control amplicon and a chromatography control. Three lines appeared on the dipstick, indicating positive results for all representative pathogenic Leptospira species, whereas two lines appeared, indicating negative results, for other bacterial species. The specificity of this biosensor assay was 100% when it was tested with 13 representative pathogenic Leptospira species, 2 intermediate Leptospira species, 1 non-pathogenic Leptospira species and 28 other bacteria species. This study found that this DNA biosensor was able to detect DNA at concentrations as low as 3.95 × 10{sup −1} genomic equivalent ml{sup −1}. An integrated m-LAMP and label-based lateral flow dipstick was successfully developed, promising simple and rapid visual detection in clinical diagnostics and serving as a point-of-care device. - Highlights: • We develop multiplex LAMP label-based lateral flow dipstick biosensor for detection of pathogenic Leptospira. • We design primers for multiplex LAMP targeting the conserved LipL32 gene of pathogenic Leptospira and LAMP

  10. Natural convective flows in a horizontal channel provided with heating isothermal blocks: Effect of the inter blocks spacing

    International Nuclear Information System (INIS)

    Bakkas, M.; Hasnaoui, M.; Amahmid, A.

    2010-01-01

    A numerical study of laminar steady natural convection induced in a two dimensional horizontal channel provided with rectangular heating blocks, periodically mounted on its lower wall, is carried out. The blocks' surface temperature, T H ' , is maintained constant and the former are connected with adiabatic surfaces. The upper wall of the channel is maintained cold at a temperature T C ' H ' . Fluid flow, temperature fields and heat transfer rates are presented for different combinations of the governing parameters which are the Rayleigh number (10 2 ≤Ra≤2x10 6 ), the blocks' spacing (1/4≤C=l ' /H ' ≤1), the blocks' height (1/8≤B=h ' /H ' ≤1/2) and the relative width of the blocks (A=(L ' -l ' )/H ' =1/2). The results obtained in the case of air (Pr = 0.72) show that the flow structure and the heat transfer are significantly influenced by the control parameters. It is found that there are situations where the increase of the blocks' spacing leads to a reduction of heat transfer.

  11. Meshless Lagrangian SPH method applied to isothermal lid-driven cavity flow at low-Re numbers

    Science.gov (United States)

    Fraga Filho, C. A. D.; Chacaltana, J. T. A.; Pinto, W. J. N.

    2018-01-01

    SPH is a recent particle method applied in the cavities study, without many results available in the literature. The lid-driven cavity flow is a classic problem of the fluid mechanics, extensively explored in the literature and presenting a considerable complexity. The aim of this paper is to present a solution from the Lagrangian viewpoint for this problem. The discretization of the continuum domain is performed using the Lagrangian particles. The physical laws of mass, momentum and energy conservation are presented by the Navier-Stokes equations. A serial numerical code, written in Fortran programming language, has been used to perform the numerical simulations. The application of the SPH and comparison with the literature (mesh methods and a meshless collocation method) have been done. The positions of the primary vortex centre and the non-dimensional velocity profiles passing through the geometric centre of the cavity have been analysed. The numerical Lagrangian results showed a good agreement when compared to the results found in the literature, specifically for { Re} < 100.00 . Suggestions for improvements in the SPH model presented are listed, in the search for better results for flows with higher Reynolds numbers.

  12. Rotary plug seal

    International Nuclear Information System (INIS)

    Ito, Koji; Abiko, Yoshihiro.

    1981-01-01

    Purpose: To enable fuel exchange even upon failure of regular seals and also to enable safety seal exchange by the detection of the reduction in the contact pressure of a rotary plug seal. Constitution: If one of a pair of regular tube seals for the rotary plug is failed during ordinary operation of a FBR type reactor, the reduction in the contact pressure of the seal to the plug gibbousness is detected by a pressure gauge and a solenoid valve is thereby closed. Thus, a back-up-tube seal provided above or below the tube seal is press-contacted by way of argon gas to the gibbousness to enter into operation state and lubricants are supplied from an oil tank. In such a structure, the back-up-tube seal is operated before the failure of the tube seal to enable to continue the fuel exchange work, as well as safety exchange for the tube seal. (Moriyama, K.)

  13. Laboratory Investigation of Rheology and Infiltration Process of Non-Newtonian Fluids through Porous Media in a Non-Isothermal Flow Regime for Effective Remediation of Contaminants

    Science.gov (United States)

    Naseer, F.

    2017-12-01

    Contamination of soil and groundwater by adsorbent (persistent) contaminants have been a major concern. Mine tailings, Acid mine drainage, waste disposal areas, active or abandoned surface and underground mines are some major causes of soil and water contamination. It is need of the hour to develop cost effective and efficient remediation techniques for clean-up of soil and aquifers. The objective of this research is to study a methodology of using non-Newtonian fluids for effective remediation of adsorbent contaminants in porous media under non-isothermal flow regimes. The research comprises of three components. Since, non-Newtonian fluid rheology has not been well studied in cold temperatures, the first component of the objective is to expose a non-Newtonian fluid (Guar gum solution) to different temperatures ranging from 30 °C through -5 °C to understand the change in viscosity, shear strength and contact angle of the fluid. Study of the flow characteristic of non-Newtonian fluids in complex porous media has been limited. Hence, the second component of this study will focus on a comparison of flow characteristics of a Newtonian fluid, non-Newtonian fluid and a combination of both fluids in a glass-tube-bundle setup that will act as a synthetic porous media. The study of flow characteristics will also be done for different thermal regimes ranging from -5 °C to 30 °C. The third component of the research will be to compare the effectiveness Guar gum to remediate a surrogate adsorbed contaminant at a certain temperature from the synthetic porous media. Guar gum is biodegradable and hence it is benign to the environment. Through these experiments, the mobility and behavior of Guar gum under varying temperature ranges will be characterized and its effectiveness in removing contaminants from soils will be understood. The impact of temperature change on the fluid and flow stability in the porous medium will be examined in this research. Guar gum is good suspension

  14. Entropy stable modeling of non-isothermal multi-component diffuse-interface two-phase flows with realistic equations of state

    KAUST Repository

    Kou, Jisheng; Sun, Shuyu

    2018-01-01

    In this paper, we consider mathematical modeling and numerical simulation of non-isothermal compressible multi-component diffuse-interface two-phase flows with realistic equations of state. A general model with general reference velocity is derived rigorously through thermodynamical laws and Onsager's reciprocal principle, and it is capable of characterizing compressibility and partial miscibility between multiple fluids. We prove a novel relation among the pressure, temperature and chemical potentials, which results in a new formulation of the momentum conservation equation indicating that the gradients of chemical potentials and temperature become the primary driving force of the fluid motion except for the external forces. A key challenge in numerical simulation is to develop entropy stable numerical schemes preserving the laws of thermodynamics. Based on the convex-concave splitting of Helmholtz free energy density with respect to molar densities and temperature, we propose an entropy stable numerical method, which solves the total energy balance equation directly, and thus, naturally satisfies the first law of thermodynamics. Unconditional entropy stability (the second law of thermodynamics) of the proposed method is proved by estimating the variations of Helmholtz free energy and kinetic energy with time steps. Numerical results validate the proposed method.

  15. An analytic solution to the time-dependent first-daughter fission-product plateout problem for multi-region isothermal slug flow

    International Nuclear Information System (INIS)

    Durkee, J.W. Jr.; Lee, C.E.

    1985-01-01

    The time-dependent, axisymmetric, isothermal slug flow convective-diffusion equation with radioactive decay is solved analytically to predict the behavior of a first-daughter fission-product undergoing gaseous transport through multiple materials in a cylindrical pipe. The integration coefficients are determined using the Davidon variable metric minimization method. The behavior of fission-product material deposited on the conduit wall is described by a standard mass-transfer model. The time-dependent plateout rate behavior, determined previously for parent fission-product deposition, is again evident for daughter product plateout. Dominance of the daughter plateout by parent deposition characteristics is apparent. The determination of the daughter wall mass-transfer and diffusion coefficient using a least-squares analysis of measured data depends upon a reasonably low ratio of parent/daughter half-lives. This is illustrated with 137 Cs/ 137 Ba(=2x10 5 ) and 140 Ba/ 140 La(=7.6), where for 137 Cs/ 137 Ba the solution sensitivity to the 137 Ba deposition parameters is small and for 140 Ba/ 140 La a reasonable solution is readily obtained. (author)

  16. Entropy stable modeling of non-isothermal multi-component diffuse-interface two-phase flows with realistic equations of state

    KAUST Repository

    Kou, Jisheng

    2018-02-25

    In this paper, we consider mathematical modeling and numerical simulation of non-isothermal compressible multi-component diffuse-interface two-phase flows with realistic equations of state. A general model with general reference velocity is derived rigorously through thermodynamical laws and Onsager\\'s reciprocal principle, and it is capable of characterizing compressibility and partial miscibility between multiple fluids. We prove a novel relation among the pressure, temperature and chemical potentials, which results in a new formulation of the momentum conservation equation indicating that the gradients of chemical potentials and temperature become the primary driving force of the fluid motion except for the external forces. A key challenge in numerical simulation is to develop entropy stable numerical schemes preserving the laws of thermodynamics. Based on the convex-concave splitting of Helmholtz free energy density with respect to molar densities and temperature, we propose an entropy stable numerical method, which solves the total energy balance equation directly, and thus, naturally satisfies the first law of thermodynamics. Unconditional entropy stability (the second law of thermodynamics) of the proposed method is proved by estimating the variations of Helmholtz free energy and kinetic energy with time steps. Numerical results validate the proposed method.

  17. Visual detection of West Nile virus using reverse transcription loop-mediated isothermal amplification combined with a vertical flow visualization strip

    Directory of Open Access Journals (Sweden)

    Zengguo eCao

    2016-04-01

    Full Text Available West Nile virus (WNV causes a severe zoonosis, which can lead to a large number of casualties and considerable economic losses. A rapid and accurate identification methodfor WNV for use in field laboratories is urgently needed. Here, a method utilizing reverse transcription loop-mediated isothermal amplification combined with a vertical flow visualization strip (RT-LAMP-VF was developed to detect the envelope (E gene of WNV. The RT-LAMP-VF assay could detect 102 copies/μl ofan WNV RNA standard using a 40 min amplification reaction followed by a 2 min incubationof the amplification product on the visualization strip, and no cross-reaction with other closely related members of theFlavivirus genus was observed. The assay was further evaluated using cells and mouse brain tissues infected with a recombinant rabies virus expressing the E protein of WNV.The assay produced sensitivities of 101.5TCID50/ml and 101.33 TCID50/ml for detection of the recombinant virus in the cells and brain tissues, respectively. Overall, the RT-LAMP-VF assay developed in this study is rapid, simple and effective, and it is therefore suitable for clinical application in the field.

  18. Visual Detection of Canine Parvovirus Based on Loop-Mediated Isothermal Amplification Combined with Enzyme-Linked Immunosorbent Assay and with Lateral Flow Dipstick

    Science.gov (United States)

    SUN, Yu-Ling; YEN, Chon-Ho; TU, Ching-Fu

    2013-01-01

    ABSTRACT Loop-mediated isothermal amplification (LAMP) combined with enzyme-linked immunosorbent assay (LAMP–ELISA) and with lateral flow dipstick (LAMP–LFD) are rapid, sensitive and specific methods for the visual detection of clinical pathogens. In this study, LAMP–ELISA and LAMP–LFD were developed for the visual detection of canine parvovirus (CPV). For LAMP, a set of four primers (biotin-labeled forward inner primers) was designed to specifically amplify a region of the VP2 gene of CPV. The optimum time and temperature for LAMP were 60 min and 65°C, respectively. The specific capture oligonucleotide probes, biotin-labeled CPV probe for LAMP–ELISA and fluorescein isothiocyanate-labeled CPV probe for LAMP–LFD were also designed for hybridization with LAMP amplicons on streptavidin-coated wells and LFD strips, respectively. For the comparison of detection sensitivity, conventional PCR and LAMP for CPV detection were also performed. The CPV detection limits by PCR, PCR–ELISA, LAMP, LAMP–ELISA and LAMP–LFD were 102, 102, 10−1, 10−1 and 10−1 TCID50/ml, respectively. In tests using artificially contaminated dog fecal samples, the samples with CPV inoculation levels of ≥1 TCID50/ml gave positive results by both LAMP–ELISA and LAMP–LFD. Our data indicated that both LAMP–ELISA and LAMP–LFD are promising as rapid, sensitive and specific methods for an efficient diagnosis of CPV infection. PMID:24334855

  19. Providing free autopoweroff plugs

    DEFF Research Database (Denmark)

    Jensen, Carsten Lynge; Hansen, Lars Gårn; Fjordbak, Troels

    2012-01-01

    Experimental evidence of the effect of providing households with cheap energy saving technology is sparse. We present results from a field experiment in which autopoweroff plugs were provided free of charge to randomly selected households. We use propensity score matching to find treatment effects...

  20. Fuel rod end plug

    International Nuclear Information System (INIS)

    McGeary, R.K.; Bucher, G.D.

    1989-01-01

    This patent describes an end plug for welded disposition within the end of a tube. It comprises a circumferentially extending, axially oriented land surface, having a radial extent defined by means of a first predetermined dimension, for disposition within the end of the tube; a circumferentially extending, axially oriented land surface, having a radial extent defined by means of a second predetermined dimension which is greater than the first predetermined dimension, for disposition outside of the end of the tube. The second land surface being disposed upstream of the first land surface; an annularly extending, radially oriented shoulder portion, defined at the downstream end of the second land surface and having a radially inward depth which is greater than the difference defined between the first and second radial dimensions of the first and second land surfaces, for engaging the end of the tube in a butt contact fashion; and annular groove means defined between the upstream end of the first land surface and the shoulder portion of the end plug, for eliminating porosity defects normally developed within a weldment defined between the tube end and the end plug when the end plug is welded within the tube end, and including a conical surface which extends radially outwardly from the innermost radial depth extent of the shoulder portion to the upstream end of the first land surface

  1. Consistent lattice Boltzmann modeling of low-speed isothermal flows at finite Knudsen numbers in slip-flow regime: Application to plane boundaries

    Science.gov (United States)

    Silva, Goncalo; Semiao, Viriato

    2017-07-01

    The first nonequilibrium effect experienced by gaseous flows in contact with solid surfaces is the slip-flow regime. While the classical hydrodynamic description holds valid in bulk, at boundaries the fluid-wall interactions must consider slip. In comparison to the standard no-slip Dirichlet condition, the case of slip formulates as a Robin-type condition for the fluid tangential velocity. This makes its numerical modeling a challenging task, particularly in complex geometries. In this work, this issue is handled with the lattice Boltzmann method (LBM), motivated by the similarities between the closure relations of the reflection-type boundary schemes equipping the LBM equation and the slip velocity condition established by slip-flow theory. Based on this analogy, we derive, as central result, the structure of the LBM boundary closure relation that is consistent with the second-order slip velocity condition, applicable to planar walls. Subsequently, three tasks are performed. First, we clarify the limitations of existing slip velocity LBM schemes, based on discrete analogs of kinetic theory fluid-wall interaction models. Second, we present improved slip velocity LBM boundary schemes, constructed directly at discrete level, by extending the multireflection framework to the slip-flow regime. Here, two classes of slip velocity LBM boundary schemes are considered: (i) linear slip schemes, which are local but retain some calibration requirements and/or operation limitations, (ii) parabolic slip schemes, which use a two-point implementation but guarantee the consistent prescription of the intended slip velocity condition, at arbitrary plane wall discretizations, further dispensing any numerical calibration procedure. Third and final, we verify the improvements of our proposed slip velocity LBM boundary schemes against existing ones. The numerical tests evaluate the ability of the slip schemes to exactly accommodate the steady Poiseuille channel flow solution, over

  2. Consistent lattice Boltzmann modeling of low-speed isothermal flows at finite Knudsen numbers in slip-flow regime: Application to plane boundaries.

    Science.gov (United States)

    Silva, Goncalo; Semiao, Viriato

    2017-07-01

    The first nonequilibrium effect experienced by gaseous flows in contact with solid surfaces is the slip-flow regime. While the classical hydrodynamic description holds valid in bulk, at boundaries the fluid-wall interactions must consider slip. In comparison to the standard no-slip Dirichlet condition, the case of slip formulates as a Robin-type condition for the fluid tangential velocity. This makes its numerical modeling a challenging task, particularly in complex geometries. In this work, this issue is handled with the lattice Boltzmann method (LBM), motivated by the similarities between the closure relations of the reflection-type boundary schemes equipping the LBM equation and the slip velocity condition established by slip-flow theory. Based on this analogy, we derive, as central result, the structure of the LBM boundary closure relation that is consistent with the second-order slip velocity condition, applicable to planar walls. Subsequently, three tasks are performed. First, we clarify the limitations of existing slip velocity LBM schemes, based on discrete analogs of kinetic theory fluid-wall interaction models. Second, we present improved slip velocity LBM boundary schemes, constructed directly at discrete level, by extending the multireflection framework to the slip-flow regime. Here, two classes of slip velocity LBM boundary schemes are considered: (i) linear slip schemes, which are local but retain some calibration requirements and/or operation limitations, (ii) parabolic slip schemes, which use a two-point implementation but guarantee the consistent prescription of the intended slip velocity condition, at arbitrary plane wall discretizations, further dispensing any numerical calibration procedure. Third and final, we verify the improvements of our proposed slip velocity LBM boundary schemes against existing ones. The numerical tests evaluate the ability of the slip schemes to exactly accommodate the steady Poiseuille channel flow solution, over

  3. FY-1979 progress report. Hydrotransport plugging study.

    Energy Technology Data Exchange (ETDEWEB)

    Eyler, L.L.; Lombardo, N.J.

    1980-01-01

    The objective of the Hydrotransport Plugging Study is to investigate phenomena associated with predicting the onset and occurrence of plugging in pipeline transport of coal. This study addresses large particle transport plugging phenomena that may be encountered in run-of-mine operations. The project is being conducted in four tasks: review and analysis of current capabilities and available data, analytical modeling, experimental investigations, and unplugging and static start-up. This report documents work completed in FY-1979 as well as work currently in progress. A review of currently available prediction methods was completed. Applicability of the methods to large particle hydrotransport and the prediction of plugging was evaluated. It was determined that available models were inadequate, either because they are empirical and tuned to a given solid or because they are simplified analytical models incapable of accounting for a wide range of parameters. Complicated regression curve fit models lacking a physical basis cannot be extrapolated with confidence. Several specific conclusions were reached: Recent developments in mechanistic modeling, describing flow conditions at the limit of stationary deposition, provide the best basis for prediction and extrapolation of large particle flow. Certain modeled phenomena require further analytical and experimental investigation to improve confidence levels. Experimental work needs to be performed to support modeling and to provide an adequate data base for comparison purposes. No available model permits treatment of solids mixtures such as coal and rock.

  4. Reactor vessel sealing plug

    International Nuclear Information System (INIS)

    Dooley, R.A.

    1986-01-01

    An apparatus is described for sealing a cold leg nozzle of a nuclear reactor pressure vessel from a remote location comprising: at least one sealing plug for mechanically sealing the nozzle from the inside of the reactor pressure vessel. The sealing plug includes a plate and a cone assembly having an end part receptive in the nozzle, the plate being axially moveable relative to the cone assembly. The plate and cone assembly have confronting bevelled edges defining an opening therebetween. A primary O-ring is disposed about the opening and is supported on the bevelled edges, the plate being guidably mounted to the cone assembly for movement toward the cone assembly to radially expand the primary O-ring into sealing engagement with the nozzle. A means is included for providing relative movement between the outer plate and the cone assembly

  5. Eulerian-Lagrangian simulation of non-isothermal gas-solid flows: particle-turbulence interactions in pipe flows; Simulation eulerienne-lagrangienne d'ecoulements gaz-solide non isothermes: interactions particules-turbulence, application aux ecoulements en conduite

    Energy Technology Data Exchange (ETDEWEB)

    Chagras, V.

    2004-03-15

    The aim of this work is to contribute to the numerical modeling of turbulent gas-solid flows in vertical or horizontal non isothermal pipes, which can be found in many industrial processes (pneumatic transport, drying, etc). The model is based on an Eulerian-Lagrangian approach allowing a fine description of the interactions between the two phases (action of the fluid upon the particles (dispersion), action of the particles upon the fluid (two way coupling) and between particles (collisions)), more or less influential according to the characteristics of the flow. The influence of the gas phase turbulence on the particle motion is taken into account using a non-isotropic dispersion model, which allows the generation of velocity and temperature fluctuations of the fluid seen by the particles. The numerical developments brought to the model for vertical and horizontal pipe flow have been validated by comparison with available experimental results from the literature. The sensitivity tests highlight the influence of the dispersion model, collisions and turbulence modulation (direct and non direct modifications ) on the dynamic and thermal behavior of the suspension. The model is able to predict the heat exchanges in the presence of particles for a wide range of flows in vertical and horizontal pipes. However numerical problems still exist in two-way coupling for very small particles and loading ratios above one. This is related to the problems encountered when modeling the coupling terms between the two phases (parameters C{sub {epsilon}}{sub 2} and C{sub {epsilon}}{sub 3} ) involved in the turbulence dissipation balance. (author)

  6. A plugging solution

    Energy Technology Data Exchange (ETDEWEB)

    Gen, O P; Azhigaliyev, G K; Dodonova, S Ye; Dyaltlova, N M; Novokhatskaya, I D; Ryabova, L I

    1984-01-01

    The purpose of the invention is to increase the durability of cement stone at 150 to 200C. The patent covers a plugging solution which consists of Portlandcement, sand and water. It additionally contains metal organic complexes of nitrylotrimethylphosphonic acid and organosiliconates of alkali or alkaline earth metals with the following component relationship in percent by mass: Portland cement, 42 to 43; sand, 27 to 28; metal organic complexes of nitrylotrimethylphosphonic acid, 0.01 to 1.5; organosiliconates of alkaline or alkaline earthmetals, 0.0025 to 0.375 and water, the remainder.

  7. Double-plug seismic connector

    International Nuclear Information System (INIS)

    Annoot, I.R.

    1984-01-01

    The double-plug seismic electric connector comprises an elongated insulating body. A male connector plug is at one end of the body and a female connector plug is at the opposite end of the body. Each plug has a pair of male and female contacts. A pair of spaced axial conductors is embedded within the insulating body for interconnecting the opposite male and female contacts. The inner end of a double-wire cable is embedded within the insulating body and each wire inner end is connected to one of the conductors

  8. Grooved tube plug rolls in

    International Nuclear Information System (INIS)

    Krausser, P.

    1991-01-01

    The removable plugs used to date by the Power Generation Group (KWU) of Siemens to seal defective steam generator tubes have a good track record. Their sealing principle is based on the elastic tensioning of three seal disks against the inside wall of the tube. Now a further removable plug is available -a roll-in plug with a metal-coated surface. It is particularly suitable for use in the roller-expanded zone of the tubes at the tube sheet. The plugs can be used in both Siemens-KWU steam generators and in steam generators manufactured in compliance with the guidelines of the ASME Code. (author)

  9. Installation of the backfill and plug test

    International Nuclear Information System (INIS)

    Gunnarsson, D.; Borgesson, L.; Hokmark, H.; Hohannesson, L.E.; Sanden, T.

    2003-01-01

    The Backfill and Plug Test is a full scale test of backfill material, backfilling technique and a tunnel plug. The main objectives of the Backfill and Plug Test are: - to develop and test different materials and compaction techniques for backfilling of tunnels excavated by blasting; - to test the function of the backfill and its interaction with the surrounding rock in a tunnel excavated by blasting; - to develop technique for building tunnel plugs and to test the function. The installation was made in the Swedish underground laboratory, Aspo HRL, during 1999. The inner part of the tunnel is not used for the test but was filled with drainage material. The test volume, which is about 28 m long, can be divided into the following three parts: - the inner part filled with backfill containing 30% bentonite; - the outer part filled with backfill without bentonite and bentonite blocks and pellets at the roof; - the plug. Permeable layers divide the test volume into 11 test sections. The permeable layers are used for increasing the water saturation rate in the backfill and for applying hydraulic gradients between the layers for studying the flow of water in the backfill and in the near field rock. The permeable layers were installed every 2.2 m and each layer is divided into three units in order to separately measure the flow close to the roof, in the central areas of the tunnel and close to the floor. The outer part ends with a wall of prefabricated concrete beams that were used for temporary support of the backfill during the casting of the plug. The upper volume close to the plug is filled with bentonite pellets and blocks consisting of 20% bentonite and 80% sand. The backfill is instrumented with 34 pore water pressure cells, 21 total pressure cells, 57 sensors for monitoring the water saturation and 13 gauges for measuring the local hydraulic conductivity. The water pressures in the permeable mats are measured in all sections. Four pressure cylinders, 2 in the roof

  10. Time and spatial heat transfer performance around an isothermally heated sphere placed in a uniform, downwardly directed flow (in relation to the enhancement of latent heat storage rate in a spherical capsule)

    International Nuclear Information System (INIS)

    Koizumi, H.

    2004-01-01

    The aim of this study is to reveal the temporal and spatial heat transfer performance of an isothermally heated sphere placed in a uniform, downwardly directed flow using a micro-foil heat flow sensor (HFS). A HFS, whose response time is about 0.02 s, was pasted on the surface of a heated copper sphere. Experiments were carried out using air with a Grashof number of 3.3 x 10 5 and with several Reynolds numbers (Re) up to 1800. Three flow patterns appeared: a chaotic flow at Re<240; a two-dimensional steady separated flow at 240 ≤ Re<500, and a three-dimensional unsteady separated flow at Re ≥ 500. In addition, the instantaneous and time-averaged heat transfer performance around the sphere in each of the three regions was clarified. Next, enhancement of the latent heat storage rate of a solid phase change material (PCM) in a spherical capsule was performed. The flow around the spherical capsule, in which the solid PCM was filled and placed in a heated, upwardly directed flow, is the approximate adverse flow phenomenon around the heated sphere which was placed in a downwardly directed flow. In other words, the buoyant flow and the forced flow are in the opposite directions in these two cases. Tests of latent heat storage were run for two Reynolds numbers which represented different flow characteristics in the heat transfer experiments, Re=150 and 1800. Furthermore, copper plates were inserted into the solid PCM, of which thermal conductivity was considerably low, to enhance the latent heat storage rate for the two Reynolds number flows

  11. Convective heat transport of high-pressure flows inside active, thick walled-tubes with isothermal outer surfaces: usage of Nusselt correlation equations for an inactive, thin walled-tube

    Energy Technology Data Exchange (ETDEWEB)

    Campo, Antonio [Idaho State Univ., Nuclear Engineering Dept., Pocatello, ID (United States); Sanchez, Alejo [Universidad de los Andes, Depto. de Ingenieria Mecanica, Merida (Venezuela)

    1998-03-01

    A semi-analytical analysis was conducted for the prediction of the mean bulk- and interface temperatures of gaseous and liquid fluids moving laminarly at high pressures inside thick-walled metallic tubes. The outer surfaces of the tubes are isothermal. The central goal of this article is to critically examine the thermal response of this kind of in-tube flows utilizing two versions of the 1-D lumped model: one is differential-numerical while the other is differential-algebraic. For the former, the local Nusselt number characterizing an inactive, isothermal tube was taken from correlation equations reported in the heat transfer literature. For the latter, a streamwise-mean Nusselt number associated with an active, isothermal tube was taken from standard correlation equations that appear in text-books on basic heat transfer. For the two different versions of the 1-D lumped model tested, the computed results consistently demonstrate that the differential-algebraic, provides accurate estimates of both the mean bulk- and the interface temperatures when compared with those temperature results computed with formal 2-D differential models. (author)

  12. Caught in-between: System for in-flow inactivation of enzymes as an intermediary step in “plug-and-play” microfluidic platforms

    DEFF Research Database (Denmark)

    Fernandes, Ana C.; Petersen, Benjamin; Møller, Lars

    2018-01-01

    for rapidenzyme inactivation. The thermal inactivation platform developed is compared with a standard benchtop ThermoMixer in terms of inactivation efficiency for glucose oxidase and catalase. A higher activity loss was observed for enzyme inactivation under flow conditions (inactivation achieved at 120 s...

  13. Generalized isothermic lattices

    International Nuclear Information System (INIS)

    Doliwa, Adam

    2007-01-01

    We study multi-dimensional quadrilateral lattices satisfying simultaneously two integrable constraints: a quadratic constraint and the projective Moutard constraint. When the lattice is two dimensional and the quadric under consideration is the Moebius sphere one obtains, after the stereographic projection, the discrete isothermic surfaces defined by Bobenko and Pinkall by an algebraic constraint imposed on the (complex) cross-ratio of the circular lattice. We derive the analogous condition for our generalized isothermic lattices using Steiner's projective structure of conics, and we present basic geometric constructions which encode integrability of the lattice. In particular, we introduce the Darboux transformation of the generalized isothermic lattice and we derive the corresponding Bianchi permutability principle. Finally, we study two-dimensional generalized isothermic lattices, in particular geometry of their initial boundary value problem

  14. 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.

  15. Borehole Plugging Program. Plugging of ERDA No. 10 drill hole

    International Nuclear Information System (INIS)

    Gulick, C.W. Jr.

    1979-06-01

    A requirement exists to plug exploratory drill holes located in the proposed Waste Isolation Pilot Plant area of Southeastern New Mexico. Sandia Laboratories, in cooperation with the US Army Corps of Engineers, Waterways Experiment Station, Concrete Laboratory, developed pumpable and durable cement grouts. These grouts were successfully used to plug an existing drill hole in the area. Results of this project are presented, along with comments and conclusions

  16. Mechanism of Randall’s Plugs Development

    Directory of Open Access Journals (Sweden)

    Felix Grases

    2017-09-01

    Full Text Available Mechanism of formation and development of intraluminal concretion, also called Randall's plug, extracted from a female patient forming calcium oxalate dihydrate (COD calculi was examined. Some of these calculi were connected to the papillary tip, and had connections with the interior of the papilla with finger-like extensions in the collecting duct (CD. The intraluminal concretion consisted of inter-grown COD crystals of irregular size (30–100 μm, approximately 5% of biological hydroxyapatite (BHAP and an organic matter. Urine of the patient was moderately supersaturated with respect to COD and amorphous calcium phosphate (ACP. Model of kidney, recently refined by Robertson, was used in calculations. Calculated Reynolds number indicated that the flow of liquid through tubules was purely laminar with parabolic velocity profile. COD crystals formed at the beginning of ascending loop of Henle by heterogeneous nucleation. Concentration of COD crystals in urine was limited and considered equal to concentration of crystals during crystaluria. The free particle and the fixed particle mechanisms were considered. The free particle mechanism assumes formation of a single crystal or agglomerate of crystals blocking the CD by virtue of size. The growth of COD crystals at concrete urinary supersaturation was too slow for a single crystal to attain size with settling velocity faster than the translation flow rate of liquid. Hydrodynamic shear caused aggregation of COD solid particles dispersed in a liquid flowing in the nephron. Number of COD crystals present in urine was not sufficient for formation of fractal agglomerate blocking the Bellini duct. Similarly, a fractal agglomerate of urinary phosphate present in the form of Posner's clusters was not large enough to obstruct the Bellini duct. The opening of the CD could not be obstructed by a single crystal of COD or fractal agglomerate composed of either COD crystals or calcium phosphate clusters, formed

  17. Evaluation of the efficiency of a plug-flow digester to produce biogas from swine waste water; Avaliacao da eficiencia de um biodigestor tubular na producao de biogas a partir de aguas residuarias de suinocultura

    Energy Technology Data Exchange (ETDEWEB)

    Feiden, Armin [Universidade Estadual do Oeste do Parana (UNIOESTE), Marechal Candido Rondon, PR (Brazil). Centro de Ciencias Agrarias; Reichl, Johann [Escola de Energia Biolsolar, Quatro Pontes, PR (Brazil); Schwab, Jair; Schwab, Vera [Colegio Estadual Entre Rios do Oeste, PR (Brazil)

    2004-07-01

    The performance of a plug-flow digester, type Reichl, was evaluated with and without mixing. The digester, treating swine wastewater, had a capacity of 800 m{sup 3} and were operated at a loading rate of 0,931 kg and 0,634 kg of total solids and volatile solids per day, respectively. With mixing, the daily average biogas production was 289,50 m{sup 3} day{sup -1}, the specific volume production of 0,362 m{sup 3} biogas m{sup -3} reactor day{sup -1} and a specific biogas production of 0,389 m{sup 3} and 0,571 m{sup 3} biogas kg{sup -1} total solids and volatile solids added, respectively. Without mixing, was observed a reduction of 17,69% on the daily average biogas production, to only 238,30 m{sup 3} day{sup -1}. It correspond to a specific volume production of 0,298 m{sup 3} biogas m{sup -3} reactor day{sup -1} and a specific biogas production of 0,320 m{sup 3} and 0,470 m{sup 3} biogas kg{sup -1} total solids and volatile solids added, respectively. With mixing, a reduction of 68,67% total solids was achieved, compared to 52,11% without mixing. Considering volatile solids, it was achieved 80,16% with mixing, compared to 58,77% without mixing. (author)

  18. Experimental and numerical modeling of sulfur plugging in carbonate reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Abou-Kassem, J.H. [Chemical and Petroleum Engineering Department, UAE University, PO Box 17555, Al-Ain (United Arab Emirates)

    2000-05-01

    Sour gas, mainly in the form of hydrogen sulfide, is produced in large amounts from many oil and gas reservoirs in the United Arab Emirates. In addition to creating problems in production lines, the precipitation of elemental sulfur in vicinity of the wellbore is often reported to cause wellbore damage. While there have been several studies performed on the role of solid deposition in gas reservoirs, the role of sulfur deposition in oil reservoirs has not been investigated. This paper presents experimental results along with a comprehensive wellbore model that predicts sulfur precipitation as well as plugging. Two separate sets of experiments, one for a gas phase system and another for a crude oil system, were conducted to investigate the deposition of elemental sulfur in (linear) carbonate cores. The gas flow tests were conducted with elemental sulfur being carried with nitrogen through limestone cores. Changes in gas flow rate were monitored while the injection pressure was held constant. A series of experiments generated valuable data for plugging with elemental sulfur. X-ray diffraction tests provided evidence of sulfur deposition along the cores. The oil flow tests were carried out to observe sulfur precipitation and plugging in a carbonate core. The crude oil was de-asphalted before conducting these tests in order to isolate the effect of asphaltene plugging. Significant plugging was observed and was found to be dependent on flow rate and initial sulfur concentration. This information was used in a phenomenological model that was incorporated in the wellbore numerical model. The data for the numerical model were obtained from both test tube and oil flow experiments. By using a phenomenological model, the wellbore plugging was modeled with an excellent match (with experimental results)

  19. Bypass flow rate control method

    International Nuclear Information System (INIS)

    Kiyama, Yoichi.

    1997-01-01

    In a PWR type reactor, bypass flow rate is controlled by exchanging existent jetting hole plugs of a plurality of nozzles disposed to the upper end of incore structures in order to flow a portion of primary coolants as a bypass flow to the upper portion of the pressure vessel. Two kinds of exchange plugs, namely, a first plug and a second plug each having a jetting out hole of different diameter are used as exchange plugs. The first plug has the diameter as that of an existent plug and the second plug has a jetting out hole having larger diameter than that of the existent plug. Remained extent plugs are exchanged to a combination of the first and the second plugs without exchanging existent plugs having seizing with the nozzles, in which the number and the diameter of the jetting out holes of the second plugs are previously determined based on predetermined total bypass flow rate to be jetted from the entire plugs after exchange of plugs. (N.H.)

  20. Plug testing and removal tool

    International Nuclear Information System (INIS)

    Baric, T.J.; Kauric, C.E.; Garcia, C.N.

    1987-01-01

    This patent describes an apparatus for testing and removing a plug from an aperture in the cylindrical core barrel wall of a nuclear reactor. The plug has an enlarged head disposed along the wall in a narrow annular access space between the wall and a surrounding cylindrical thermal neutron shield. The apparatus comprises: fixed jaw means; movable jaw means pivotally connected to the fixed jaw means for movement with respect thereto between an open position accommodating reception of the plug head between the fixed and movable jaw means and a closed position for securely gripping the plug head between the fixed and movable jaw means; drive means carried by the fixed jaw means and coupled to the movable jaw means for effecting movement thereof between the open and closed positions thereof; and tensioning means carried by the jaw means for engagement with the core barrel when the jaw means are disposed in gripping engagement with the plug head for exerting on the jaw means and the gripped plug a predetermined force in a direction radially outwardly of the wall. The jaw means and the drive means and the tensioning means all have dimensions radially of the wall substantially less than the radial thickness of the access space to permit insertion into, movement within and removal from the access space

  1. Isothermal Martensite Formation

    DEFF Research Database (Denmark)

    Villa, Matteo

    Isothermal (i.e. time dependent) martensite formation in steel was first observed in the 40ies of the XXth century and is still treated as an anomaly in the description of martensite formation which is considered as a-thermal (i.e. independent of time). Recently, the clarification of the mechanism...... of lattice strains provided fundamental information on the state of stress in the material and clarified the role of the strain energy on martensite formation. Electron backscatter diffraction revealed that the microstructure of the material and the morphology of martensite were independent on the cooling...... leading to isothermal kinetics acquired new practical relevance because of the identification of isothermal martensite formation as the most likely process responsible for enhanced performances of sub-zero Celsius treated high carbon steel products. In the present work, different iron based alloys...

  2. Adiabatic and isothermal resistivities

    International Nuclear Information System (INIS)

    Fishman, R.S.

    1989-01-01

    The force-balance method is used to calculate the isothermal resistivity to first order in the electric field. To lowest order in the impurity potential, the isothermal resistivity disagrees with the adiabatic results of the Kubo formula and the Boltzmann equation. However, an expansion of the isothermal resistivity in powers of the impurity potential is divergent, with two sets of divergent terms. The first set arises from the density matrix of the relative electron-phonon system. The second set arises from the explicit dependence of the density matrix on the electric field, which was ignored by force-balance calculations. These divergent contributions are calculated inductively, by applying a recursion relation for the Green's functions. Using the λ 2 t→∞ limit of van Hove, I show that the resummation of these divergent terms yields the same result for the resistivity as the adiabatic calculations, in direct analogy with the work of Argyres and Sigel, and Huberman and Chester

  3. Instabilities of isothermal liquid films

    International Nuclear Information System (INIS)

    Solesio, J.N.

    1977-04-01

    The integral forms of the mass and linear momentum balances are given for a two-phase flow system with surface tension and without material surface properties. The instantaneous local laws for each phase and the jump conditions for the interface are derived from these balance laws. Then, these laws are systematically simplified by means of dimensional analysis for an isothermal liquid film flowing down a plane. The stability studies of films are critically reviewed. The different methods are divided into two groups: the first one deals with the global approach, the second one with the perturbation theory. This group includes a new technique based upon the method of quadrature by differentiation. Finally, the different methods are compared [fr

  4. Dialysis grafts arterial plug: Retrieval using the tulip sheath device in vitro

    International Nuclear Information System (INIS)

    Sharafuddin, Melhem J.; Titus, Jack L.; Gu Xiaoping; Hunter, David W.; Amplatz, Kurt

    1997-01-01

    The 'arterial plug' is a resistant thrombus that frequently persists at the arterial anastomosis of clotted hemodialysis grafts following thrombolytic therapy. We studied the physical and morphological characteristics of the plug and determined the feasibility of transcatheter removal in vitro using the tulip compression thrombectomy system. Sixteen thrombus plugs were recovered during surgical thrombectomy of clotted human dialysis grafts. The physical and gross physical characteristics of all plugs were analyzed. Eight specimens were evaluated microscopically. Transcatheter compression thrombectomy of eight plugs was attempted in vitro. Each plug was embedded in a polyvinyl tube filled with newly clotted blood and connected to a flow circuit. First, balloon-assisted aspiration thrombectomy (BAT) of soft thrombus was performed, while sparing the distal-most segment containing the plug. The tulip sheath was then introduced facing the 'arterial end' of the tube. The thrombus segment containing the plug was pulled back into the tulip mesh using either a 3 Fr Fogarty balloon catheter or a self-expanding rake. The tulip was closed to compress and remove the trapped plug. Near-complete thrombectomy of soft clot was achieved in all tested tubes. Compression and retrieval of the entire arterial plug was successful in all except one, where only partial compression of the plug occurred, presumably due to fibrotic changes. No fragmentation or embolization occurred in the remaining procedures. Spongy consistency was noted in 94% of the specimens. Microscopic evaluation showed organized layered thrombus with compaction in five plugs. Transcatheter removal of a thrombus plug is feasible in vitro using the tulip compression-thrombectomy system

  5. Preparation and Characterization of Chemical Plugs Based on Selected Hanford Waste Simulants

    International Nuclear Information System (INIS)

    Mattigod, Shas V.; Wellman, Dawn M.; Parker, Kent E.; Cordova, Elsa A.; Gunderson, Katie M.; Baum, Steven R.; Crum, Jarrod V.; Poloski, Adam P.

    2008-01-01

    This report presents the results of preparation and characterization of chemical plugs based on selected Hanford Site waste simulants. Included are the results of chemical plug bench testing conducted in support of the M1/M6 Flow Loop Chemical Plugging/Unplugging Test (TP-RPP-WTP-495 Rev A). These results support the proposed plug simulants for the chemical plugging/ unplugging tests. Based on the available simulant data, a set of simulants was identified that would likely result in chemical plugs. The three types of chemical plugs that were generated and tested in this task consisted of: 1. Aluminum hydroxide (NAH), 2. Sodium aluminosilicate (NAS), and 3. Sodium aluminum phosphate (NAP). While both solvents, namely 2 molar (2 M) nitric acid (HNO3) and 2 M sodium hydroxide (NaOH) at 60 C, used in these tests were effective in dissolving the chemical plugs, the 2 M nitric acid was significantly more effective in dissolving the NAH and NAS plugs. The caustic was only slightly more effecting at dissolving the NAP plug. In the bench-scale dissolution tests, hot (60 C) 2 M nitric acid was the most effective solvent in that it completely dissolved both NAH and NAS chemical plugs much faster (1.5 - 2 x) than 2 M sodium hydroxide. So unless there are operational benefits for the use of caustic verses nitric acid, 2 M nitric acid heated to 60 C should be the solvent of choice for dissolving these chemical plugs. Flow-loop testing was planned to identify a combination of parameters such as pressure, flush solution, composition, and temperature that would effectively dissolve and flush each type of chemical plug from preformed chemical plugs in 3-inch-diameter and 4-feet-long pipe sections. However, based on a review of the results of the bench-top tests and technical discussions, the Waste Treatment Plant (WTP) Research and Technology (R and T), Engineering and Mechanical Systems (EMS), and Operations concluded that flow-loop testing of the chemically plugged pipe sections

  6. A study on thimble plug removal for PWR plants

    Energy Technology Data Exchange (ETDEWEB)

    Song, Dong Soo; Lee, Chang Sup; Lee, Jae Yong; Jun, Hwang Yong [Korea Electric Power Research Institute, Taejon (Korea, Republic of)

    1997-12-31

    The thermal-hydraulic effects of removing the RCC guide thimble plugs are evaluated for 8 Westinghouse type PWR plants in Korea as a part of feasibility study: core outlet loss coefficient, thimble bypass flow, and best estimate flow. It is resulted that the best estimate thimble bypass flow increases about by 2% and the best estimate flow increases approximately by 1.2%. The resulting DNBR penalties can be covered with the current DNBR margin. Accident analyses are also investigated that the dropped rod transient is shown to be limiting and relatively sensitive to bypass flow variation. 8 refs., 5 tabs. (Author)

  7. A study on thimble plug removal for PWR plants

    Energy Technology Data Exchange (ETDEWEB)

    Song, Dong Soo; Lee, Chang Sup; Lee, Jae Yong; Jun, Hwang Yong [Korea Electric Power Research Institute, Taejon (Korea, Republic of)

    1998-12-31

    The thermal-hydraulic effects of removing the RCC guide thimble plugs are evaluated for 8 Westinghouse type PWR plants in Korea as a part of feasibility study: core outlet loss coefficient, thimble bypass flow, and best estimate flow. It is resulted that the best estimate thimble bypass flow increases about by 2% and the best estimate flow increases approximately by 1.2%. The resulting DNBR penalties can be covered with the current DNBR margin. Accident analyses are also investigated that the dropped rod transient is shown to be limiting and relatively sensitive to bypass flow variation. 8 refs., 5 tabs. (Author)

  8. (CSTR) and 1-plug flow reactor (PFR)

    African Journals Online (AJOL)

    Administrator

    2010-12-27

    Dec 27, 2010 ... 2Department of Chemical Engineering, Obafemi Awolowo University, Ile Ife, Osun State, Nigeria. ... modeled as PFR and described by Michaelis. Menten equation. Designed equations derived from the two equations are used for the reactor sizing of ... Herbivores make a living on cellulose by possessing.

  9. Cyclic variation of heat flux on spark plug; Tenka plug bu no netsuryusoku hendo no sokutei

    Energy Technology Data Exchange (ETDEWEB)

    Ishii, K.; Sasaki, T.; Urata, Y. [Honda Motor Co. Ltd., Tokyo (Japan); Kagawa, J.; Matsutani, W. [NGK Spark Plug Co. Ltd., Nagoya (Japan)

    1998-02-25

    This paper examines the relationship between the magnitude of the heat flux to the spark plug ground electrode, averaged over an 80` crank angle (CA) of early compression stroke, and the initial burning rate, defined as the CA at which 5% of mass is burned. The heat flux was measured by a thin-film thermocouple with the hot junction on the surface of ground electrode. The results demonstrate that faster initial burning rate correlated well with increasing heat flux from the spark plug to the mixture. The difference in the magnitude and direction of the heat flux is associated with the amount of residual gas concentration and thus the results show the effect of residual gas concentration. The cycle-averaged heat flux from the hot junction is 0.367 MW/m{sup 2}, corresponding to a total heat flow of 20 W from the total surface area of ground electrode. This value is about an order of magnitude larger than that previously reported in the literature for locations away from the spark plug, e. g. at the cylinder wall. 11 refs., 9 figs., 1 tab.

  10. Design approaches for access plugs in a basalt repository

    International Nuclear Information System (INIS)

    O'Rourke, J.; Allirot, D.; O'Connor, K.

    1982-01-01

    This paper describes research, laboratory testing, and analytical approaches taken toward the development of designs for sealing boreholes, shafts, and tunnels penetrating from ground surface to a deep, mined nuclear waste repository in basalt. A material selection process leading to identification of preferred sealing materials is discussed, and the laboratory testing program to define the geochemical and geotechnical performance of these materials is described. Analysis of the environmental conditions in the Columbia Plateau basalt flows leads to identification of tentative design criteria for plug systems. These design criteria include performance of the plug as a hydraulic barrier and as a radionuclide barrier. An important problem for effective performance of a plug system as a hydraulic barrier is shown to be a potentially disturbed zone surrounding the excavation in the stressed and jointed host rock. An idealized one-dimensional numerical model is described for analyzing the performance of the plug as a barrier to radionuclide transport. The preliminary analyses led to the conclusion that the composition and dimensions of practical candidate plugs can satisfy both hydraulic and radionuclide barrier criteria. Examples of candidate designs are shown for boreholes, shafts, and tunnels. 9 references, 6 figures, 6 tables

  11. Aspergillus fumigatus colonization of punctal plugs.

    Science.gov (United States)

    Tabbara, Khalid F

    2007-01-01

    Punctal plugs are used in patients with dry eye syndrome to preserve the tears. In this report, I present two cases of Aspergillus fumigatus colonization of punctal plugs. Observational series of two cases. Approval was obtained from the institutional review board. Two men aged 29 and 31 years developed black spots inside the hole of punctal plug, which looked like eyeliner deposits. The deposits inside the hole of the plug in each patient were removed and cultured. Cultures of the two punctal plugs black deposits grew A fumigatus. Bacterial cultures were negative. Colonization of the punctal plug hole with A fumigatus was observed in two cases. It is recommended that punctal plugs be removed in patients undergoing refractive or intraocular procedures or in patients who are receiving topical corticosteroids. Current punctal plugs should be redesigned to avoid the presence of an inserter hole.

  12. Oscillation of an isolated liquid plug inside a dry capillary

    Science.gov (United States)

    Srinivasan, Vyas; Kumar, Siddhartha; Asfer, Mohammed; Khandekar, Sameer

    2017-11-01

    The present work reports an experimental study on the dynamics of partially wetting isolated liquid plug (DI water), which is made to oscillate inside a square, glass capillary tube (1 mm × 1 mm; 60 mm length). The liquid plug is made to oscillate pneumatically at two different frequencies (0.25 and 0.35 Hz), using a cam-follower mechanism. Bright field imaging is used to visualize the three-phase contact line behavior, while, micro-Particle Imaging Velocimetry (PIV) apparatus is used to discern the nature of flow inside the oscillating liquid plug. During a cycle, due to the partial wetting nature of DI water, the three-phase contact line at the menisci gets pinned at the extreme end of each stroke, where the dynamic apparent contact angle gets drastically altered before the initiation of the next stroke. The difference between the apparent contact angle of the front and rear meniscus are seen to be a function of the oscillating frequency; the difference increasing with increasing frequency. The flow inside the liquid plug reveals unique non-Poiseuille flow features near the meniscus, due to free-slip boundary condition, which leads to formation of distinct vortex pairs behind it. The vortices too change their direction during each stroke of the oscillation, eventually leading to an alternating recirculation pattern inside the plug. The results clearly indicate that improved mathematical models are required for predicting transport parameters in such flows, which are important in engineering systems such as pulsating heat pipes, lab-on-chip devices and PEM fuel cells.

  13. Simulation of steam generator plugging tubes in a PWR to analyze the operating impact

    Energy Technology Data Exchange (ETDEWEB)

    Pla, Patricia, E-mail: patricia.pla-freixa@ec.europa.eu [Nuclear Reactor Safety Assessment Unit, Institute for Energy and Transport, Joint Research Centre (JRC) of the European Commission, Petten (Netherlands); Reventos, Francesc, E-mail: francesc.reventos@upc.edu [Technical University of Catalonia (UPC), Barcelona (Spain); Martin Ramos, Manuel, E-mail: manuel.martin-ramos@ec.europa.eu [Nuclear Safety and Security Coordination Unit, Policy Support Coordination, Joint Research Centre of the European Commission, Brussels (Belgium); Sol, Ismael, E-mail: isol@anacnv.com [Asociación Nuclear Ascó-Vandellós-II (ANAV), Tarragona (Spain); Strucic, Miodrag, E-mail: miodrag.strucic@ec.europa.eu [Nuclear Reactor Safety Assessment Unit, Institute for Energy and Transport, Joint Research Centre (JRC) of the European Commission, Petten (Netherlands)

    2016-08-15

    Highlights: • Plugging a fraction of the SG tubes does not affect power output of the plant. • There is a limit to SG plugging in the range of 10–15%. • The rupture of a SG tube in a 12% plugged SG has shown no significant differences in operator actions. • A SBLOCA in a 12% plugged SG has shown no significant differences in operator actions. - Abstract: A number of nuclear power plants (NPPs) with pressurized water reactors (PWR) in the world have replaced their steam generators (SG) due to degradation of the SG tubes caused by different problems. Several methods were attempted to correct the defects of the tubes, but eventually the only permanent solution was to plug them. The consequences of plugging the tubes are the decrease of heat transfer surface, the reduction of the flow area and subsequent reduction of the primary system mass flow and for a fraction of plugged tubes higher than a given value, the reduction of reactor output and economic losses. The objective of this paper is to analyze whether steam generator tube plugging has an impact in the effectiveness of accident management actions. An analysis with Relap5 Mod 3.3 patch03 for the Spanish reactor Ascó-2, a 3-loop 2940.6 MWth Westinghouse PWR, in which plugging of steam generator tubes are simulated, is presented in order to find the limit for the adequate operation of the plant. Several steady state calculations were performed with different fractions of plugged SG tubes, by modeling the reduction of the primary to secondary heat transfer surface and the reduction of the primary coolant mass flow area in the tubes as well. The results of the analysis yield that plugging 12% of the SG tubes is around the limit for optimal reactor operation. To complete the study two events, in which the steam generators are used to cooldown the plant, were simulated to find out if the plugging of SGs tubes could influence the efficiency of the operator actions described in the emergency operating

  14. Simultaneous resolution of reactive radioactive decay, non-isothermal flow, and migration with application to the performance assessment for HLW repositories

    International Nuclear Information System (INIS)

    Juncosa, R.; Delgado, J.; Font, I.

    2010-01-01

    Radioactive decay is an important subject to take into account when studying the thermo-hydro-dynamic behavior of the buffer clay material used in the containment of radioactive waste. The modern concepts for the multibarrier design of a repository of high level waste in deep geologic formations consider that once canisters have failed, the buffer clay material must ensure the retention and/or delay of radionuclides within the time framework given in the assessment studies. Within the clay buffer, different chemical species are retarded/fixed according to several physicochemical processes (ion exchange, surface complexation, precipitation, matrix diffusion,..) but typical approaches do not consider the eventuality that radioactive species change their chemical nature (i.e. phase) thereby affecting their reactive behavior. The radioactive decay of an element takes place independently of the phase (aqueous, solid or gaseous) to which it belongs. This means that, in terms of radionuclide fixation, some geochemical processes will be effective scavengers (for instance mineral precipitation of crystal growth) while others will not (for instance ion exchange and/or sorption). In this contribution we present a reactive radioactive decay model of any number of chemical components including those that belong to decay series. The model, which is named FLOW-DECAY, also takes into account flow and isotopic migration and it has been applied considering a hypothetical model scenario provided by the project ENRESA 2000 and direct comparison with the results generated by the probabilistic code GoldSim. Results indicate that FLOW-DECAY may simulate the decay processes in a similar way that GoldSim, being the differences related to factors associated to code architecture. (orig.)

  15. Shielding plug for LMFBR type reactors

    International Nuclear Information System (INIS)

    Hashiguchi, Ko.

    1979-01-01

    Purpose: To enable effective removal of liquid metals deposited, if any, in the gaps between a rotary plug and a fixed plug in LMFBR type reactors. Constitution: A plate incorporated with a heater and capable of projecting in a gap between a rotary plug and a fixed plug, and a scraper connected in perpendicular to it are provided to the rotary plug. Solidified liquid metals such as sodium deposited in the gap are effectively removed by the heating with the heater and the scraping action due to the rotation. (Horiuchi, T.)

  16. Experimental investigation of liquid-liquid plug formation in a T-junction microchannel

    Science.gov (United States)

    Angeli, Panagiota; Chinaud, Maxime; Roumpea, Eynagelia-Panagiota; Weheliye, Weheliye; Omar. K. Matar Collaboration; Lyes Kahouadji Collaboration

    2015-11-01

    Plug formation mechanism of two immiscible liquids was studied experimentally in a 200 μm microchannel using two innovative micro Particle Image Velocimetry (μ PIV) techniques i.e. two-colour μ PIV and high speed bright field μ PIV. The aqueous phase was a water/glycerol solution whereas the organic phase was silicon oil with a range of viscosities from 5 to 155 cSt. Experiments were conducted for different fluid flow rate combinations in the T-junction inlet and it was observed that velocity profiles within the forming plugs depend on the flow rate ratios. The velocity field studies provided insight into the plug mechanism revealing that the interface curvature at the rear of the forming plug changes sign at the later stages of plug formation and accelerates the thinning of the meniscus leading to plug breakage. Results from the two-colour PIV show that the continuous phase resists the flow of the dispersed phase into the main channel at the rear of the plug meniscus and causes the change in the interface curvature. Department of Chemical Engineering South Kensington Campus Imperial College London SW7 2AZ.

  17. Pore-scale investigation of biomass plug development and propagation in porous media.

    Science.gov (United States)

    Stewart, Terri L; Scott Fogler, H

    2002-03-05

    Biomass plugging of porous media finds application in enhanced oil recovery and bioremediation. An understanding of biomass plugging of porous media was sought by using a porous glass micromodel through which biomass and nutrient were passed. This study describes the pore-scale physics of biomass plug propagation of Leuconostoc mesenteroides under nutrient-rich conditions. It was found that, as the nutrient flowed through the micromodel, the initial biomass plug occurred at the nutrient-inoculum interface due to growth in the larger pore throats. As growth proceeded, biomass filled and closed these larger pore throats, until only isolated groupings of pore throats with smaller radii remained empty. As nutrient flow continued, a maximum pressure drop was reached. At the maximum pressure drop, the biomass yielded in a manner similar to a Bingham plastic to form a breakthrough channel consisting of a path of interconnected pore throats. The channel incorporated the isolated groupings of empty pore throats that had been present before breakthrough. As the nutrient flow continued, subsequent plugs developed as breakthrough channels refilled with biomass and in situ growth was stimulated in the region just downstream of the previous plug. The downstream plugs had a higher fraction of isolated groupings of empty pore throats, which can be attributed to depletion of nutrient downstream. When the next breakthrough channel formed, it incorporated these isolated groupings, causing the breakthrough channels to be branched. It was observed that the newly formed plug could be less stable with this higher fraction of empty pore throats and that the location of breakthrough channels changed in subsequent plugs. This change in breakthrough channel location could be attributed to the redistribution of nutrient flow and the changes in flowrate in the pore throats. Copyright 2002 John Wiley & Sons, Inc. Biotechnol Bioeng 77: 577-588, 2002; DOI 10.1002/bit.10044

  18. Loop-Mediated Isothermal Amplification-Lateral-Flow Dipstick (LAMP-LFD) to detect Toxoplasma gondii oocyst in ready-to-eat salad.

    Science.gov (United States)

    Lalle, Marco; Possenti, Alessia; Dubey, Jitender P; Pozio, Edoardo

    2018-04-01

    The apicomplexan parasite Toxoplasma gondii is the causative agent of toxoplasmosis, a foodborne zoonosis with a global distribution and estimated to cause up to 20% of the total foodborne disease burden in Europe. Association between T. gondii infection and the consumption of unwashed raw fruits and vegetables contaminated with oocysts has been reported and the increasing habit to eat pre-washed ready-to-eat salads poses a new potential risk for consumers. It is therefore important to trace the occurrence of potential contamination with this parasite to guarantee the safety of ready-to-eat vegetables. Detection of T. gondii in vegetables by molecular techniques has been achieved but low sensitivity (PCR) or expensive equipments (qPCR) limit routine applicability. Here, we describe the development and validation of a sensitive and robust method relying on a LAMP assay, targeting the 529 bp locus, to detect T. gondii oocysts down to 25 oocysts/50 g in ready-to-eat baby lettuce. The LAMP has been also adapted for a faster visualization of the result by a lateral flow dipstick chromatographic detection method. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Refueling system with small diameter rotatable plugs

    International Nuclear Information System (INIS)

    Ritz, W.C.

    1987-01-01

    This patent describes a liquid-metal fastbreeder nuclear reactor comprising a reactor pressure vessel and closure head therefor, a reactor core barrel disposed within the reactor vessel and enclosing a reactor core having therein a large number of closely spaced fuel assemblies, and the reactor core barrel and the reactor core having an approximately concentric circular cross-sectional configuration with a geometric center in predetermined location within the reactor vessel. The improved refueling system described here comprises: a large controllably rotatable plug means comprising the substantial portion of the closure head, a reactor upper internals structure mounted from the large rotatable plug means. The large rotatable plug means has an approximately circular configuration which approximates the cross-sectional configuration of the reactor core barrel with a center of rotation positioned a first predetermined distance from the geometric center of the reactor core barrel so that the large rotatable plug means rotates eccentrically with respect to the reactor core barrel; a small controllably rotatable plug means affixed to the large rotatable plug means and rotatable with respect thereto. The small rotatable plug means has a center of rotation which is offset a second predetermined distance from the rotational center of the large rotatable plug means so that the small rotatable plug means rotates eccentrically with respect to the large rotatable plug means

  20. Biodegradable microfabricated plug-filters for glaucoma drainage devices.

    Science.gov (United States)

    Maleki, Teimour; Chitnis, Girish; Park, Jun Hyeong; Cantor, Louis B; Ziaie, Babak

    2012-06-01

    We report on the development of a batch fabricated biodegradable truncated-cone-shaped plug filter to overcome the postoperative hypotony in nonvalved glaucoma drainage devices. Plug filters are composed of biodegradable polymers that disappear once wound healing and bleb formation has progressed past the stage where hypotony from overfiltration may cause complications in the human eye. The biodegradable nature of device eliminates the risks associated with permanent valves that may become blocked or influence the aqueous fluid flow rate in the long term. The plug-filter geometry simplifies its integration with commercial shunts. Aqueous humor outflow regulation is achieved by controlling the diameter of a laser-drilled through-hole. The batch compatible fabrication involves a modified SU-8 molding to achieve truncated-cone-shaped pillars, polydimethylsiloxane micromolding, and hot embossing of biodegradable polymers. The developed plug filter is 500 μm long with base and apex plane diameters of 500 and 300 μm, respectively, and incorporates a laser-drilled through-hole with 44-μm effective diameter in the center.

  1. Mitigation of Syngas Cooler Plugging and Fouling

    Energy Technology Data Exchange (ETDEWEB)

    Bockelie, Michael J. [Reaction Engineering International, Salt Lake City, UT (United States)

    2015-06-29

    This Final Report summarizes research performed to develop a technology to mitigate the plugging and fouling that occurs in the syngas cooler used in many Integrated Gasification Combined Cycle (IGCC) plants. The syngas cooler is a firetube heat exchanger located downstream of the gasifier. It offers high thermal efficiency, but its’ reliability has generally been lower than other process equipment in the gasification island. The buildup of ash deposits that form on the fireside surfaces in the syngas cooler (i.e., fouling) lead to reduced equipment life and increased maintenance costs. Our approach to address this problem is that fouling of the syngas cooler cannot be eliminated, but it can be better managed. The research program was funded by DOE using two budget periods: Budget Period 1 (BP1) and Budget Period 2 (BP2). The project used a combination of laboratory scale experiments, analysis of syngas cooler deposits, modeling and guidance from industry to develop a better understanding of fouling mechanisms and to develop and evaluate strategies to mitigate syngas cooler fouling and thereby improve syngas cooler performance. The work effort in BP 1 and BP 2 focused on developing a better understanding of the mechanisms that lead to syngas cooler plugging and fouling and investigating promising concepts to mitigate syngas cooler plugging and fouling. The work effort focused on the following: • analysis of syngas cooler deposits and fuels provided by an IGCC plant collaborating with this project; • performing Jet cleaning tests in the University of Utah Laminar Entrained Flow Reactor to determine the bond strength between an ash deposit to a metal plate, as well as implementing planned equipment modifications to the University of Utah Laminar Entrained Flow Reactor and the one ton per day, pressurized Pilot Scale Gasifier; • performing Computational Fluid Dynamic modeling of industrially relevant syngas cooler configurations to develop a better

  2. The impact of NPP Krsko steam generator tube plugging on minimum DNBR at nominal conditions

    International Nuclear Information System (INIS)

    Lajtman, S.

    1996-01-01

    Typically, steam generator tube plugging (SGTP) both decreases the reactor coolant system (RCS) flow rate and the heat transfer surface area of the steam generator. At a constant thermal power and vessel outlet temperature, as tube plugging increases, the vessel average temperature, vessel inlet temperature and steam generator secondary side steam pressure decrease. This paper presents the analysis of impact of SGTP on Minimum Departure from Nucleate Boiling Ratio (MDNBR) at NPP Krsko (NEK), using the Improved Thermal Design Procedure (ITDP), WRB-1 correlation, and COBRA-III-C computer code. No credit was given to high plugging percentage region power reduction resulting from turbine volumetric flow limitations. MDNBR is found to be decreasing with increasing plugging, but not under the limiting values. (author)

  3. Plug Load Behavioral Change Demonstration Project

    Energy Technology Data Exchange (ETDEWEB)

    Metzger, I.; Kandt, A.; VanGeet, O.

    2011-08-01

    This report documents the methods and results of a plug load study of the Environmental Protection Agency's Region 8 Headquarters in Denver, Colorado, conducted by the National Renewable Energy Laboratory. The study quantified the effect of mechanical and behavioral change approaches on plug load energy reduction and identified effective ways to reduce plug load energy. Load reduction approaches included automated energy management systems and behavioral change strategies.

  4. Nuclear fuel rod end plug weld inspection

    International Nuclear Information System (INIS)

    Parker, M. A.; Patrick, S. S.; Rice, G. F.

    1985-01-01

    Apparatus and method for testing TIG (tungsten inert gas) welds of end plugs on a sealed nuclear reactor fuel rod. An X-ray fluorescent spectrograph testing unit detects tungsten inclusion weld defects in the top end plug's seal weld. Separate ultrasonic weld inspection system testing units test the top end plug's seal and girth welds and test the bottom end plug's girth weld for penetration, porosity and wall thinning defects. The nuclear fuel rod is automatically moved into and out from each testing unit and is automatically transported between the testing units by rod handling devices. A controller supervises the operation of the testing units and the rod handling devices

  5. Multimeediaetendus : Opera Gets Plugged / Eve Arpo

    Index Scriptorium Estoniae

    Arpo, Eve

    2008-01-01

    Eesti Muusika- ja Teatriakadeemia lühiooperite õhtul "Opera Gets Plugged" etendunud lavastustest - Monika Mattieseni "DMeeter" ja Age Hirve "Tuleloitsija": Mõlema lavastaja ja projektijuht Liis Kolle

  6. Friction Pull Plug and Material Configuration for Anti-Chatter Friction Pull Plug Weld

    Science.gov (United States)

    Littell, Justin Anderson (Inventor)

    2016-01-01

    A friction pull plug is provided for use in forming a plug weld in a hole in a material. The friction pull plug includes a shank and a series of three frustoconical sections. The relative sizes of the sections assure that a central one of the sections defines the initial contact point between the hole's sides. The angle defined by the central one of the sections reduces or eliminates chatter as the plug is pulled into the hole.

  7. From catastrophic acceleration to deceleration of liquid plugs in prewetted capillary tubes

    Science.gov (United States)

    Magniez, Juan; Baudoin, Michael; Zoueshtiagh, Farzam; Lemac/Lics Team

    2016-11-01

    Liquid/gas flows in capillaries are involved in a multitude of systems including flow in porous media, petroleum extraction, imbibition of paper or flows in pulmonary airways in pathological conditions. Liquid plugs, witch compose the biphasic flows, can have a dramatic impact on patients with pulmonary obstructive diseases, since they considerably alter the circulation of air in the airways and thus can lead to severe breathing difficulties. Here, the dynamics of liquid plugs in prewetted capillary tube is investigated experimentally and theoretically, with a particular emphasis on the role of the prewetting films and of the driving condition (constant flow rate, constant pressure). For both driving conditions, the plugs can either experience a continuous increase or decrease of their size. While this phenomenon is regular in the case of imposed flow rate, a constant pressure head can lead to a catastrophic acceleration of the plug and eventually its rupture or a dramatic increase of the plug size. A theoretical model is proposed to explain the transition between theses two regimes. These results give a new insight on the critical pressure required for airways obstruction and reopening. IEMN, International Laboratory LEMAC/LICS, UMR CNRS 8520, University of Lille.

  8. AN INVESTIGATION OF THE EFFECT OF THE HOT END PLUGS ON THE EFFICIENCY OF THE RANQUE-HILSCH VORTEX TUBE

    Directory of Open Access Journals (Sweden)

    MAZIAR ARJOMANDI

    2007-12-01

    Full Text Available The phenomenon of temperature distribution in confined steady rotating gas flows is called Ranque-Hilsch effect. The simple counter-flow vortex tube consists of a long hollow cylinder with tangential nozzle at one end for injecting compressed air. The flow inside the vortex tube can be described as rotating air, which moves in a spring-shaped vortex track. The peripheral flow moves toward the hot end where a hot end plug is placed and the axial flow, which is forced back by the plug, moves in the opposite direction toward the cold end. This paper focuses on the effect of the size of hot nozzle on the performance of the Ranque–Hilsch vortex tube. Series of plugs were used in the experiment in order to find the relationship between the diameter of hot end plug and the performance of the vortex tube.

  9. Rapid and sensitive detection of novel avian-origin influenza A (H7N9 virus by reverse transcription loop-mediated isothermal amplification combined with a lateral-flow device.

    Directory of Open Access Journals (Sweden)

    Yiyue Ge

    Full Text Available A severe disease in humans caused by a novel avian-origin influenza A (H7N9 virus emerged in China recently, which has caused at least 128 cases and 26 deaths. Rapid detection of the novel H7N9 virus is urgently needed to differentiate the disease from other infections, and to facilitate infection control as well as epidemiologic investigations. In this study, a reverse transcription loop-mediated isothermal amplification combined with a lateral flow device (RT-LAMP-LFD assay to rapidly detect H7N9 virus was developed and evaluated. The RT-LAMP primers were designed to target the haemagglutinin (HA and neuraminidase (NA genes of H7N9 virus. Results of 10-fold dilution series assays showed that analysis of RT-LAMP products by the LFD method was as sensitive as real-time turbidity detection, and that the analytic sensitivities of the HA and NA RT-LAMP assays were both 10 copies of synthetic RNA. Furthermore, both the assays showed 100% clinical specificity for identification of H7N9 virus. The performance characteristics of the RT-LAMP-LFD assay were evaluated with 80 clinical specimens collected from suspected H7N9 patients. The NA RT-LAMP-LFD assay was more sensitive than real time RT-PCR assay. Compared with a combination of virus culture and real-time RT-PCR, the sensitivity, specificity, positive predictive value, and negative predictive value of the RT-LAMP-LFD assay were all 100%. Overall, The RT-LAMP-LFD assay established in this study can be used as a reliable method for early diagnosis of the avian-origin influenza A (H7N9 virus infection.

  10. Preliminary validation of direct detection of foot-and-mouth disease virus within clinical samples using reverse transcription loop-mediated isothermal amplification coupled with a simple lateral flow device for detection.

    Directory of Open Access Journals (Sweden)

    Ryan A Waters

    Full Text Available Rapid, field-based diagnostic assays are desirable tools for the control of foot-and-mouth disease (FMD. Current approaches involve either; 1 Detection of FMD virus (FMDV with immuochromatographic antigen lateral flow devices (LFD, which have relatively low analytical sensitivity, or 2 portable RT-qPCR that has high analytical sensitivity but is expensive. Loop-mediated isothermal amplification (LAMP may provide a platform upon which to develop field based assays without these drawbacks. The objective of this study was to modify an FMDV-specific reverse transcription-LAMP (RT-LAMP assay to enable detection of dual-labelled LAMP products with an LFD, and to evaluate simple sample processing protocols without nucleic acid extraction. The limit of detection of this assay was demonstrated to be equivalent to that of a laboratory based real-time RT-qPCR assay and to have a 10,000 fold higher analytical sensitivity than the FMDV-specific antigen LFD currently used in the field. Importantly, this study demonstrated that FMDV RNA could be detected from epithelial suspensions without the need for prior RNA extraction, utilising a rudimentary heat source for amplification. Once optimised, this RT-LAMP-LFD protocol was able to detect multiple serotypes from field epithelial samples, in addition to detecting FMDV in the air surrounding infected cattle, pigs and sheep, including pre-clinical detection. This study describes the development and evaluation of an assay format, which may be used as a future basis for rapid and low cost detection of FMDV. In addition it provides providing "proof of concept" for the future use of LAMP assays to tackle other challenging diagnostic scenarios encompassing veterinary and human health.

  11. Principle plug design for deposition tunnels

    International Nuclear Information System (INIS)

    Haaramo, M.; Lehtonen, A.

    2009-06-01

    This report examines the plug structures to be built in the deposition tunnels of the repository. The deposition tunnels located below the depth of 400 metres have been used as input data. Each plug consists of a massive concrete structure. The planned maximum pressure acting on the plug is 7.5 MPa. It consists of 4.5 MPa of groundwater pressure and 3 MPa of swelling pressure of the backfill. Five different plug types have been examined. Two of them (butt and irregular plug) turned out to be difficult from the point of view of other works in the central and deposition tunnels. One type (straight plug) requires a lot of construction material. Wedge-shaped and dome plugs have been examined more carefully. The wedge shaped plug has advantageous properties in comparison with the dome plug, such as a three dimensional state of stress, the wedging effect which increases strength as pressure increases and larger tolerances for the excavation of the slot. Leakage water has a longer path through the wedge shaped plug than through the dome plug. Pressure load affects the wedge shaped plug, creating normal stresses, which are compressive along each coordinate axis. The long-term rise in temperature in the deposition tunnels can produce high extra stresses in all the plug alternatives. These stresses make it necessary to increase the strength of the concrete or the distance between the plug and the nearest deposition hole. The stability effects of different plug distances and deposition tunnel orientations have been examined. The plug does not significantly affect stresses in the surrounding bedrock or the stability of the bedrock. Stresses caused by excavation and temperature rise are decisive factors. A groundwater chloride content of 0-3% in the environment of the repository is used as input data. It affects the tightness of the concrete and the quality of the cement. Cement has to be sulphate resistant with a low pH value. Low pH results in the weakening of the corrosion

  12. Staged fracturing of horizontal shale gas wells with temporary plugging by sand filling

    Directory of Open Access Journals (Sweden)

    Xing Liang

    2017-03-01

    Full Text Available Due to downhole complexities, shale-gas horizontal well fracturing in the Sichuan Basin suffered from casing deformation and failure to apply the technique of cable-conveyed perforation bridge plug. In view of these problems, a new technique of staged volume fracturing with temporary plugging by sand filling is employed. Based on theoretical analyses and field tests, a design of optimized parameters of coiled tubing-conveyed multi-cluster sand-blasting perforation and temporary plugging by sand filling was proposed. It was applied in the horizontal Well ZJ-1 in which casing deformation occurred. The following results are achieved in field operations. First, this technique enables selective staged fracturing in horizontal sections. Second, this technique can realize massive staged fracturing credibly without mechanical plugging, with the operating efficiency equivalent to the conventional bridge plug staged fracturing. Third, full-hole is preserved after fracturing, thus it is possible to directly conduct an open flow test without time consumption of a wiper trip. The staged volume fracturing with temporary plugging by sand filling facilitated the 14-stage fracturing in Well ZJ-1, with similar SRV to that achieved by conventional bridge plug staged fracturing and higher gas yield than neighboring wells on the same well pad. Thus, a new and effective technique is presented in multi-cluster staged volume fracturing of shale gas horizontal wells.

  13. A direct digital controller for an automatic sodium plugging meter

    International Nuclear Information System (INIS)

    Tobias, A.

    1977-07-01

    A plugging meter is a device for monitoring the impurity level of liquid sodium. It is used to measure the temperature at which an impurity precipitates or re-dissolves at a restricting orifice. The concentration of the impurity may be then deduced from known solubility/temperature relationships. A software controller for a sodium plugging meter has been implemented on a PDP-11 using SWEPSPEED. The algorithm used to perform both flow and temperature control functions is based on a modified standard three-term controller. Both design and operation of the controller are described. The functions which may be performed by the controller are: (i) maintain a steady temperature at the restricting orifice, (ii) perform a temperature ramp at a rate defined by the operator, and (iii) maintain a partial plug of impurities at the orifice by appropriate manipulation of the temperature. Accuracies so far achieved are approximately +- 5% for flow control and better that +- 1 0 C for temperature control. (author)

  14. Mastering Eclipse plug-in development

    CERN Document Server

    Blewitt, Alex

    2014-01-01

    If you are a Java developer who is familiar with the Eclipse plug-in environment, this book covers the advanced concepts that you need to know to achieve true expertise. Prior experience in creating Eclipse plug-ins is assumed for this book.

  15. Plugging regime in the pump limiter throat

    International Nuclear Information System (INIS)

    Ghendrih, P.; Grosman, A.; Samain, A.; Capes, H.; Morera, J.P.

    1988-08-01

    The plugging regime -with no outstreaming neutral flux- is studied for a closed configuration pump limiter (throat). We derive the plugging length and the neutral density build-up at the neutralizer plate. The analytical expressions are supported by numerical evidence. We find an improved efficiency related to the throat effect mainly due to neutral-sidewall interactions

  16. Plug-In Tutor Agents: Still Pluggin'

    Science.gov (United States)

    Ritter, Steven

    2016-01-01

    "An Architecture for Plug-in Tutor Agents" (Ritter and Koedinger 1996) proposed a software architecture designed around the idea that tutors could be built as plug-ins for existing software applications. Looking back on the paper now, we can see that certain assumptions about the future of software architecture did not come to be, making…

  17. Multiservice utility plug for remote fuel reprocessing

    International Nuclear Information System (INIS)

    Goldmann, L.H. Jr.; Jensen, D.A.

    1979-10-01

    This paper presents the design of a multiservice utility plug and drive system to be used for reliably engaging and disengaging all utility connections automatically that serve large portable equipment modules. The modules are arranged into a fuel processing production line within the Fuels and Materials Examination Laboratory. The utility plugs allow the modules to be easily replaced, rearranged or removed for maintenance

  18. Explosive plugging of nuclear heat exchangers

    International Nuclear Information System (INIS)

    Crossland, B.; Bahrani, A.S.; Townsley, W.J.

    1977-01-01

    Explosive welding is a well established process for cladding one metal on another or for welding tubes to tubeplates or lap welding, etc. Recently, the process has been adapted to plugging of heat exchangers in conventional and nuclear power plant, where it has already been accepted especially in situations where the access is difficult and remote from the site of plugging. The paper describes the explosive plugging techniques developed in the Department of Mechanical and Industrial Engineering of The Queen's University of Belfast for the reheater and superheater of the PFR, and for the reheater of the AGR. For the PFR a point charge system has been used which causes a spherical expansion of the plug, which gives two zones of welding. Initially for the much larger plug required for the AGR it was proposed to use a parallel stand-off welding set-up, but it proved difficult or impossible to avoid a crevice. Consequently, a rim charge set-up has been developed which gives a circular ring expansion of the plug with two zones of welding. Besides the problem of the design of the plug and explosive charge geometry it has also been necessary to consider the distortion of holes adjoining the hole in which a plug is welded. Bunging of adjoining holes in order to reduce the distortion has also been investigated

  19. Mixture for plugging absorption zones

    Energy Technology Data Exchange (ETDEWEB)

    Sitinkov, G V; Kovalenko, N G; Makarov, L V; Zinnatulchin, Ts Kh

    1981-01-17

    A mixture is proposed for plugging absorption zones. The mixture contains synthetic polymer and a solvent. So as to increase the penetrability of the mixture through a reduction in its viscosity and an increase in insulation properties, the compound contains either Capron or Neilon as the synthetic polyamide resin polmyer, and concentrated chloride as the solvent. The mixture is prepared in a special AzINMASh-30 unit (acid cart). After the mixture has been produced, it is injected into the borehole by means of an acid cart pump. So as to prevent coaggulation at the point when the mixture in injected into the stratum through tubes, the mixture is placed betwen chemically inert fluids, for example, a clay mortar. The inert and compressed fluids are injected by means of a cementing unit. The entire process of production and application of the mixture is simple and fully automated through the use of well-known equipment.

  20. Plug-in Hybrid Initiative

    Energy Technology Data Exchange (ETDEWEB)

    Goodman, Angie; Moore, Ray; Rowden, Tim

    2013-09-27

    Our main project objective was to implement Plug-in Electric Vehicles (PEV) and charging infrastructure into our electric distribution service territory and help reduce barriers in the process. Our research demonstrated the desire for some to be early adopters of electric vehicles and the effects lack of education plays on others. The response of early adopters was tremendous: with the initial launch of our program we had nearly 60 residential customers interested in taking part in our program. However, our program only allowed for 15 residential participants. Our program provided assistance towards purchasing a PEV and installation of Electric Vehicle Supply Equipment (EVSE). The residential participants have all come to love their PEVs and are more than enthusiastic about promoting the many benefits of driving electric.

  1. Plugging criteria for steam generator tubes with axial cracks near tube support plates

    International Nuclear Information System (INIS)

    Mattar Neto, Miguel

    2000-01-01

    Stress corrosion cracking with intergranular attack occurs on the secondary side of steam generator (SG) tubes where impurities concentrate due to boiling under restricted flow conditions. In the most of cases, it can be called ODSCC (Outer Diameter Stress Corrosion Cracking). The typical locations are areas near support plates, in sludge piles and at top of tubesheet crevices. Though it can also occur on free spans under the relatively thin deposits that build up on the tube surfaces. ODSCC near tube plate supports have been the cause of plugging of many tubes. Thus, studies on SG tubes plugging criteria related to this degradation mechanism are presented in this paper. Th purpose is to avoid unnecessary tube plugging from either safety or reliability standpoint. Based on these studies some conclusions on the plugging criteria and on the difficulties to apply them are addressed. (author)

  2. Ford Plug-In Project: Bringing PHEVs to Market Demonstration and Validation Project

    Energy Technology Data Exchange (ETDEWEB)

    D' Annunzio, Julie [Ford Motor Company, Dearborn, MI (United States); Slezak, Lee [U.S. DOE Office of Energy Efficiency & Renewable Energy, Washington, DC (United States); Conley, John Jason [National Energy Technology Lab. (NETL), Albany, OR (United States)

    2014-03-26

    This project is in support of our national goal to reduce our dependence on fossil fuels. By supporting efforts that contribute toward the successful mass production of plug-in hybrid electric vehicles, our nation’s transportation-related fuel consumption can be offset with energy from the grid. Over four and a half years ago, when this project was originally initiated, plug-in electric vehicles were not readily available in the mass marketplace. Through the creation of a 21 unit plug-in hybrid vehicle fleet, this program was designed to demonstrate the feasibility of the technology and to help build cross-industry familiarity with the technology and interface of this technology with the grid. Ford Escape PHEV Demonstration Fleet 3 March 26, 2014 Since then, however, plug-in vehicles have become increasingly more commonplace in the market. Ford, itself, now offers an all-electric vehicle and two plug-in hybrid vehicles in North America and has announced a third plug-in vehicle offering for Europe. Lessons learned from this project have helped in these production vehicle launches and are mentioned throughout this report. While the technology of plugging in a vehicle to charge a high voltage battery with energy from the grid is now in production, the ability for vehicle-to-grid or bi-directional energy flow was farther away than originally expected. Several technical, regulatory and potential safety issues prevented progressing the vehicle-to-grid energy flow (V2G) demonstration and, after a review with the DOE, V2G was removed from this demonstration project. Also proving challenging were communications between a plug-in vehicle and the grid or smart meter. While this project successfully demonstrated the vehicle to smart meter interface, cross-industry and regulatory work is still needed to define the vehicle-to-grid communication interface.

  3. Friction Pull Plug Welding in Aluminum Alloys

    Science.gov (United States)

    Brooke, Shane A.; Bradford, Vann

    2012-01-01

    NASA's Marshall Space Flight Center (MSFC) has recently invested much time and effort into the process development of Friction Pull Plug Welding (FPPW). FPPW, is a welding process similar to Friction Push Plug Welding in that, there is a small rotating part (plug) being spun and simultaneously pulled (forged) into a larger part. These two processes differ, in that push plug welding requires an internal reaction support, while pull plug welding reacts to the load externally. FPPW was originally conceived as a post proof repair technique for the Space Shuttle fs External Tank. FPPW was easily selected as the primary weld process used to close out the termination hole on the Constellation Program's ARES I Upper Stage circumferential Self-Reacting Friction Stir Welds (SR-FSW). The versatility of FPPW allows it to also be used as a repair technique for both SR-FSW and Conventional Friction Stir Welds. To date, all MSFC led development has been concentrated on aluminum alloys (2195, 2219, and 2014). Much work has been done to fully understand and characterize the process's limitations. A heavy emphasis has been spent on plug design, to match the various weldland thicknesses and alloy combinations. This presentation will summarize these development efforts including weld parameter development, process control, parameter sensitivity studies, plug repair techniques, material properties including tensile, fracture and failure analysis.

  4. Plug cementing: Horizontal to vertical conditions

    Energy Technology Data Exchange (ETDEWEB)

    Calvert, D.G.; Heathman, J.F.; Griffith, J.E.

    1995-12-31

    This paper presents an in-depth study of cement plug placement that was conducted with large-scale models for the improvement of plug cementing practices and plug integrity. Common hole and workstring geometries were examined with various rheology and density ratios between the drilling fluid and cement. The critical conditions dictating the difference between success and failure for various wellbore angles and conditions were explored, and the mechanisms controlling slurry movement before and after placement are now better understood. An understanding of these mechanisms allows the engineer to better tailor a design to specific hole conditions. Controversial concepts regarding plug-setting practices have been examined and resolved. The cumulative effects of density, rheology, and hole angle are major factors affecting plug success. While the Boycott effect and an extrusion effect were observed to be predominant in inclined wellbores, a spiraling or {open_quotes}roping{close_quotes} effect controls slurry movement in vertical wellbores. Ultimate success of a cement plug can be obtained if allowances are made for these effects in the job design, provided all other previously published recommended placement practices are followed. Results of this work can be applied to many sidetracking and plug-to-abandon operations. Additionally, the understanding of the fluid movement (creep) mechanisms holds potential for use in primary and remedial cementing work, and in controlling the placement of noncementitious fluids in the wellbore.

  5. Amplatzer vascular plugs in congenital cardiovascular malformations

    International Nuclear Information System (INIS)

    Barwad, Parag; Ramakrishnan, Sivasubramanian; Kothari, Shyam S; Saxena, Anita; Gupta, Saurabh K; Juneja, Rajnish; Gulati, Gurpreet Singh; Jagia, Priya; Sharma, Sanjiv

    2013-01-01

    Amplatzer vascular plugs (AVPs) are devices ideally suited to close medium-to-large vascular communications. There is limited published literature regarding the utility of AVPs in congenital cardiovascular malformations (CCVMs). To describe the use of AVPs in different CCVMs and to evaluate their safety and efficacy. All patients who required an AVP for the closure of CCVM were included in this retrospective review of our catheterization laboratory data. The efficacy and safety of AVPs are reported. A total of 39 AVPs were implanted in 31 patients. Thirteen (33%) were AVP type I and 23 (59%) were AVP type II. AVP type III were implanted in two patients and type IV in one patient. The major indications for their use included closure of pulmonary arteriovenous malformation (AVM) (n = 7), aortopulmonary collaterals (n = 7), closure of a patent Blalock-Taussig shunt (n = 5), systemic AVM (n = 5), coronary AVM (n = 4), patent ductus arteriosus (PDA) (n = 3), pulmonary artery aneurysms (n = 3), and venovenous collaterals (n = 2). Deployment of the AVP was done predominantly via the 5 – 7F Judkin's right coronary guide catheter. Overall 92% of the AVPs could be successfully deployed and resulted in occlusion of the target vessel in all cases, within 10 minutes. No procedure-related or access site complication occurred. AVPs are versatile, easy to use, and effective devices to occlude the vascular communications in a variety of settings. AVP II is especially useful in the closure of tubular structures with a high flow

  6. EBR-II rotating plug seal maintenance

    International Nuclear Information System (INIS)

    Allen, K.J.

    1986-01-01

    The EBR-II rotating plug seals require frequent cleaning and maintenance to keep the plugs from sticking during fuel handling. Time consuming cleaning on the cover gas and air sides of the dip ring seal is required to remove oxidation and sodium reaction products that accumulate and stop plug rotation. Despite severely limited access, effective seal cleaning techniques have removed 11 800 lb (5 352 kg) of deposits from the seals since 1964. Temperature control modifications and repairs have also required major maintenance work. Suggested seal design recommendations could significantly reduce maintenance on future similar seals

  7. Wear on Plugged Tube due to the Foreign Objects on the Secondary Side of Steam Generator

    International Nuclear Information System (INIS)

    Kim, Hyung Nam; Cho, Nam Cheoul; Nam, Min Woo

    2013-01-01

    In this paper, the changes of the tube frequency and amplitude are introduced before and after plugging. The amplitude of the bottom span for the steam generator tube is not much changed after tube plugging. Moreover, the contact force between the plugged tube and the foreign object is the same as that of intact tube and the foreign object. However, the frequencies of plugged tubes are about 9∼12% higher than those of intact tubes. That means the wear due to the foreign object would be accelerated after the tube plugging. Therefore, the tube stabilizer should be installed when the tube is plugged due to the foreign object wear. The tube wall of steam generator is a pressure boundary between the coolant of the primary system and the feedwater of the secondary system. It is very important to insure the structural integrity of the tubes because the radioactive coolant is flow into the feedwater due to the pressure difference as the result of tube failure. The degradations of steam generator tubes are corrosion, wear, fatigue and foreign object wear, etc. The foreign object wear is one of mechanical degradation due to materials flew into the secondary side of steam generator. The steam generator tubes, estimated not to insure structural integrity from the results of the nondestructive evaluation such as eddy current test and visual inspection, are excluded from the service with plugging. However, the tube wear is still being progressed after the plugging because the relative motion between the tube and structure is still existed due to the secondary side flow in the steam generator. If the tube is completely cut because of the degradation, the tube can be a stress or of failure of tubes around the plugged tube. The contact force between the structure and tube is lowered as the wear is progressed. However, the contact force between the foreign object and tube is not changed as the wear is progressed. Therefore, the structural integrity of tubes around the foreign

  8. Three dimensional calculations of the primary coolant flow in a 900 MW PWR vessel. Steady state and transients computations

    International Nuclear Information System (INIS)

    Martin, A.; Alvarez, D.; Cases, F.

    1996-03-01

    The paper explains the chronological account and the first results obtained in the R and D program on the mixing in the 900 MW PWR vessels. After the presentation of the plant type simulated, we define the numerical tool, the (Finite Element Modelling) FEM N3S code. Two results are presented with a comparison with the experiment results issued of the BORA BORA mock up. The first case is dealing with the isothermal steady state mixing in the vessel with the three loops mass flow rate balanced. This case identified as a validation of our numerical tool shows a good agreement. The second case is dealing with the transient mixing of a clear plug in the vessel when one primary pump starts-up. We compare the numerical and experiment results giving the mean boron concentration at the core inlet for several clear water plugs. The results show again a good agreement. (authors). 12 refs., 10 figs., 1 tab

  9. Storage shaft definitive closure plug and method

    International Nuclear Information System (INIS)

    Dardaine, M.

    1992-01-01

    A definitive closure plug system for radioactive waste storage at any deepness, is presented. The inherent weight of the closure materials is used to set in the plug: these materials display an inclined sliding surface in such a way that when the closure material rests on a stable surface of the shaft storage materials, the relative sliding of the different materials tends to spread them towards the shaft internal wall so as to completely occlude the shaft

  10. Plug-In Hybrid Electric Vehicle Basics | NREL

    Science.gov (United States)

    Plug-In Hybrid Electric Vehicle Basics Plug-In Hybrid Electric Vehicle Basics Imagine being able to one that's in a standard hybrid electric vehicle. The larger battery pack allows plug-in hybrids to between fill-ups) that's very similar to the range of a conventional vehicle. A plug-in hybrid vehicle's

  11. Test plan: Potash Core Test. WIPP experimental program borehole plugging

    International Nuclear Information System (INIS)

    Christensen, C.L.

    1979-09-01

    The Potash Core Test will utilize a WIPP emplaced plug to obtain samples of an in-situ cured plug of known mix constituents for bench scale testing. An earlier effort involved recovery at the salt horizon of Plug 217, a 17 year old plug in a potash exploration hole for bond testing, but the lack of particulars in the emplacement precluded significant determination of plug performance

  12. Acoustic and aerodynamic performance investigation of inverted velocity profile coannular plug nozzles. [variable cycle engines

    Science.gov (United States)

    Knott, P. R.; Blozy, J. T.; Staid, P. S.

    1981-01-01

    The results of model scale parametric static and wind tunnel aerodynamic performance tests on unsuppressed coannular plug nozzle configurations with inverted velocity profile are discussed. The nozzle configurations are high-radius-ratio coannular plug nozzles applicable to dual-stream exhaust systems typical of a variable cycle engine for Advanced Supersonic Transport application. In all, seven acoustic models and eight aerodynamic performance models were tested. The nozzle geometric variables included outer stream radius ratio, inner stream to outer stream ratio, and inner stream plug shape. When compared to a conical nozzle at the same specific thrust, the results of the static acoustic tests with the coannular nozzles showed noise reductions of up to 7 PNdB. Extensive data analysis showed that the overall acoustic results can be well correlated using the mixed stream velocity and the mixed stream density. Results also showed that suppression levels are geometry and flow regulation dependent with the outer stream radius ratio, inner stream-to-outer stream velocity ratio and inner stream velocity ratio and inner stream plug shape, as the primary suppression parameters. In addition, high-radius ratio coannular plug nozzles were found to yield shock associated noise level reductions relative to a conical nozzle. The wind tunnel aerodynamic tests showed that static and simulated flight thrust coefficient at typical takeoff conditions are quite good - up to 0.98 at static conditions and 0.974 at a takeoff Mach number of 0.36. At low inner stream flow conditions significant thrust loss was observed. Using an inner stream conical plug resulted in 1% to 2% higher performance levels than nozzle geometries using a bent inner plug.

  13. Amplatzer vascular plugs in congenital cardiovascular malformations

    Directory of Open Access Journals (Sweden)

    Parag Barwad

    2013-01-01

    Full Text Available Background: Amplatzer vascular plugs (AVPs are devices ideally suited to close medium-to-large vascular communications. There is limited published literature regarding the utility of AVPs in congenital cardiovascular malformations (CCVMs. Aims: To describe the use of AVPs in different CCVMs and to evaluate their safety and efficacy. Materials and Methods: All patients who required an AVP for the closure of CCVM were included in this retrospective review of our catheterization laboratory data. The efficacy and safety of AVPs are reported. Results: A total of 39 AVPs were implanted in 31 patients. Thirteen (33% were AVP type I and 23 (59% were AVP type II. AVP type III were implanted in two patients and type IV in one patient. The major indications for their use included closure of pulmonary arteriovenous malformation (AVM (n = 7, aortopulmonary collaterals (n = 7, closure of a patent Blalock-Taussig shunt (n = 5, systemic AVM (n = 5, coronary AVM (n = 4, patent ductus arteriosus (PDA (n = 3, pulmonary artery aneurysms (n = 3, and venovenous collaterals (n = 2. Deployment of the AVP was done predominantly via the 5 - 7F Judkin′s right coronary guide catheter. Overall 92% of the AVPs could be successfully deployed and resulted in occlusion of the target vessel in all cases, within 10 minutes. No procedure-related or access site complication occurred. Conclusions: AVPs are versatile, easy to use, and effective devices to occlude the vascular communications in a variety of settings. AVP II is especially useful in the closure of tubular structures with a high flow.

  14. Flow patterns in vertical two-phase flow

    International Nuclear Information System (INIS)

    McQuillan, K.W.; Whalley, P.B.

    1985-01-01

    This paper is concerned with the flow patterns which occur in upwards gas-liquid two-phase flow in vertical tubes. The basic flow patterns are described and the use of flow patter maps is discussed. The transition between plug flow and churn flow is modelled under the assumption that flooding of the falling liquid film limits the stability of plug flow. The resulting equation is combined with other flow pattern transition equations to produce theoretical flow pattern maps, which are then tested against experimental flow pattern data. Encouraging agreement is obtained

  15. Understand rotating isothermal collapses yet

    International Nuclear Information System (INIS)

    Tohline, J.E.

    1985-01-01

    A scalar virial equation is used to describe the dynamic properties of equilibrium gas clouds, taking into account the relative effects of surface pressure, rotation, self gravity and internal isothermal pressure. Details concerning the internal structure of the clouds are ignored in order to obtain a globalized analytical expression. The obtained solution to the equation is found to agree with the surface-pressure-dominated model of Stahler (1983), and the rotation-dominated model of Hayashi, Narita, and Miyama (1982). On the basis of the analytical expression of virial equilibrium in the clouds, some of the limiting properties of isothermal clouds are described, and a realistic starting model for cloud collapse is proposed. 18 references

  16. Tube Plugging Criteria for the High-pressure Heaters of Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyungnam; Cho, Nam-Cheoul; Lee, Kuk-hee [KHNP Central Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    In this paper, a method to establish the tube plugging criteria of BOP heat exchangers is introduced and the tube plugging criteria for the high pressure heaters of a nuclear power plant. This method relies on the similar plugging criteria used in the steam generator tubes. Power generation field urges nuclear power plants to reduce operating and maintaining costs to remain competitive. To reduce the cost by means of preventing the lowering thermal efficiency, the inspection of balance-of-plant heat exchanger, which was treated as not important work, becomes important. The tubing materials and tube thickness of heat exchangers in nuclear power plants are selected to withstand system temperature, pressure, and corrosion. But tubes have experienced leaks and failures and plugged based upon eddy current testing (ET) results. There are some problems for plugging the heat exchanger tubes since the criterion and its basis are not clearly described. For this reason, the criteria for the tube wall thickness are addressed in order to operate the heat exchangers in nuclear power plant without trouble during the cycle. The feed water heater is a kind of heat exchanger which raises the temperature of water supplied from the condenser. The heat source of high-pressure heaters is the extraction steam from the high-pressure turbine and moisture separator re-heater. If the tube wall of the heater is broken, the feed water flowing inside the tube intrudes to shell side. This forces the turbine to be stop in order to protect it. There are many codes and standards to be referred for calculating the minimum thickness of the heat exchanger tube in the designing stage. However, the codes and standards related to show the tube plugging criteria may not exist currently. A method to establish the tube plugging criteria of BOP heat exchangers is introduced and the tube plugging criteria for the high pressure heaters of Ulchin NPP No. 3 and 4. This method relies on the similar plugging

  17. Tube Plugging Criterion for the TPCCW Heat Exchanger of Yonggwang NPP 1 and 2

    International Nuclear Information System (INIS)

    Kim, Hyung Nam; Yoo, Hyun Ju; Choi, Sung Nam; Song, Seok Yoon

    2009-01-01

    The turbine plant component cooling water(TPCCW) system circulates the cooling water to cool the components in the turbine building and discharges the heat from the components through the TPCCW heat exchanger. Recently, Yonggwang NPP 1 and 2 replaced the TPCCW heat exchanger because of tube degradation. The tubing material of new TPCCW heat exchanger of Yonggwang NPP 1 and 2 is titanium. If the tube wall cannot withstand the pressure, the cooling water with the chemicals flows into the tube side and it is discharged to the open water. The chemicals can pollute the open water. Therefore, the tubes of the TPCCW heat exchanger should be inspected and degraded tubes should be plugged. It is inevitable for the materials of the components to be degraded as the power plants become older. The degradation accompanies increasing maintenance cost as well as creating safety issues. The materials and wall thickness of heat exchanger tubes in nuclear power plants are selected to withstand system temperature, pressure, and corrosion. However, tubes have experienced leaks and failures and plugged based upon eddy current testing (ET) results. There are some problems for plugging the heat exchanger tubes since the criterion and its basis are not clearly described. For this reason, the criteria for the tube wall thickness are addressed in order to operate the heat exchangers in nuclear power plant without trouble during the cycle. There are many codes and standards to be referred for calculating the minimum thickness of the heat exchanger tube in the designing stage. However, the codes and standards related to show the tube plugging criteria may not exist currently. In this paper, a method to establish the tube plugging criteria of BOP heat exchangers, which is based on the USNRC Regulatory Guide 1.121, is introduced and the tube plugging criteria for the TPCCW heat exchanger of Yonggwang NPP No. 1 and 2. This method relies on the similar plugging criteria used in the steam generator

  18. Tube Plugging Criterion for the TPCCW Heat Exchanger of Yonggwang NPP 1 and 2

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyung Nam; Yoo, Hyun Ju; Choi, Sung Nam; Song, Seok Yoon [Korea Electric Power Research Institute, Daejeon (Korea, Republic of)

    2009-05-15

    The turbine plant component cooling water(TPCCW) system circulates the cooling water to cool the components in the turbine building and discharges the heat from the components through the TPCCW heat exchanger. Recently, Yonggwang NPP 1 and 2 replaced the TPCCW heat exchanger because of tube degradation. The tubing material of new TPCCW heat exchanger of Yonggwang NPP 1 and 2 is titanium. If the tube wall cannot withstand the pressure, the cooling water with the chemicals flows into the tube side and it is discharged to the open water. The chemicals can pollute the open water. Therefore, the tubes of the TPCCW heat exchanger should be inspected and degraded tubes should be plugged. It is inevitable for the materials of the components to be degraded as the power plants become older. The degradation accompanies increasing maintenance cost as well as creating safety issues. The materials and wall thickness of heat exchanger tubes in nuclear power plants are selected to withstand system temperature, pressure, and corrosion. However, tubes have experienced leaks and failures and plugged based upon eddy current testing (ET) results. There are some problems for plugging the heat exchanger tubes since the criterion and its basis are not clearly described. For this reason, the criteria for the tube wall thickness are addressed in order to operate the heat exchangers in nuclear power plant without trouble during the cycle. There are many codes and standards to be referred for calculating the minimum thickness of the heat exchanger tube in the designing stage. However, the codes and standards related to show the tube plugging criteria may not exist currently. In this paper, a method to establish the tube plugging criteria of BOP heat exchangers, which is based on the USNRC Regulatory Guide 1.121, is introduced and the tube plugging criteria for the TPCCW heat exchanger of Yonggwang NPP No. 1 and 2. This method relies on the similar plugging criteria used in the steam generator

  19. Numerical studies of pulsating buoyant plume in isothermal and non isothermal situations

    International Nuclear Information System (INIS)

    Sharma, Pavan K.; Singh, R.K.; Mohanty, Ananya; Das, D.

    2014-01-01

    A computational study has been carried out for predicting the behaviour of buoyant plume in isothermal and non isothermal configuration. General simulation objectives of any buoyant flow simulation are macroscopic in nature and deals with the grass data in respect of buoyancy induced scalar transport. However, the accuracy of predicting such macroscopic parameters is a strong function of several other microscopic parameters which govern the overall macroscopic behaviour. Some of the microscopic parameters for analysis could be buoyancy induced stable/unstable flows, relative plume behaviour, baroclinic velocity distribution etc. Only the CFD based flow modelling approach is capable of calculating several of these aspects. LES based modelling scores over the conventional RANS based computational modelling. The primary objective of the present study was to model buoyant plume simulation of different types in order to explore the details regarding plume and flow structure, instabilities and puffing behaviour. One of the influencing parameters on the overall plume behaviour is the buoyancy resolution index i.e. fineness of chosen grid in relation to the buoyancy intensity and other hydrodynamic parameters. The grid sensitivity studies have been carried out to find out the optimum value grid size by way of buoyant pool fire simulations. Comparative simulation has also been made for a square and round pool fire and it was found that for engineering simulations equivalent area square pool modeling is sufficient. Using the optimum value of grid size and square pool shape simulations have been carried out for different value of fire intensity. The flame puffing frequency as calculated by the reported correlation was compared against the computationally observed puffing frequency and the agreement was generally found to be excellent. Besides these results the comparisons of predicted peak flames temperatures data for various case studies with the available experimental data

  20. Experimental and numerical modeling of sulfur plugging in a carbonate oil reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Al-Awadhy, F. [ADMA-OPCO, Abudhabi (United Arab Emirates); Kocabas, I.; Abou-Kassem, J.H. [UAE University, Al Ain (United Arab Emirates); Islam, M.R. [Dalhousie University, Halifax, NS (United States)

    2005-01-15

    Many oil and gas reservoirs in the United Arab Emirates produce large amounts of sour gas, mainly in the form of hydrogen sulfide. In addition to creating problems in the production line, wellbore damage is often reported due to the precipitation of elemental sulfur in the vicinity of the wellbore. While there have been several studies performed on the role of solid deposition in a gas reservoir, the role of sulfur deposition in oil reservoirs has not been investigated. This article presents experimental results along with a comprehensive wellbore model that predicts sulfur precipitation as well as plugging. The experiments were conducted in a core (linear) system. Both analytical and numerical modelings were performed in a linear coordinate system. Data for the numerical model was obtained from both test tube and coreflood experiments. By using a phenomenological model, the wellbore plugging was modeled with an excellent match (with experimental results). The crude oil was de-asphalted prior to conducting the experiment in order to isolate the effect of asphaltene plugging. A series of coreflood tests was carried out to observe sulfur precipitation and plugging in a carbonate rock. Significant plugging was observed and was found to be dependent on flow rate and initial sulfur concentration. This information was used in the phenomenological model and can be incorporated in the wellbore numerical model. (author)

  1. Thermo-hydraulic analysis of the generic equatorial port plug design

    International Nuclear Information System (INIS)

    Rodríguez, E.; Guirao, J.; Ordieres, J.; Cortizo, J.L.; Iglesias, S.

    2012-01-01

    Highlights: ► Thermo-hydraulic transient performance evaluation and optimization of the GEPP structure cooling/heating system under neutronic heating and baking conditions. ► The optimization of the GEPP box structure's cooling system includes positioning and minimization of number and size of gun drilled channels, complying with the flow and functional requirements during operating and baking conditions. - Abstract: The port-based ITER diagnostic systems are housed primarily in two locations, the equatorial and upper port plugs. The port plug structure provides confinement function, maintains ultra-high vacuum quality and the first confinement barrier for radioactive materials at the ports. The port plug structure design, from the ITER International Organisation (IO), is cooled and heated by pressurized water which flows through a series of gun-drilled water channels and water pipes. The cooling function is required to remove nuclear heating due to radiation during operation of ITER, while the heating function is intended to heat up uniformly the machine during baking condition. The work presented provides coupled thermo-hydraulic analysis and optimization of a Generic Equatorial Port Plug (GEPP) structure cooling and heating system. The optimization performed includes positioning, minimization of number and size of gun drilled channels, complying with the flow and functional requirements during operating and baking conditions.

  2. Sorption isotherms: A review on physical bases, modeling and measurement

    Energy Technology Data Exchange (ETDEWEB)

    Limousin, G. [Atomic Energy Commission, Tracers Technology Laboratory, 38054 Grenoble Cedex (France) and Laboratoire d' etude des Transferts en Hydrologie et Environnement (CNRS-INPG-IRD-UJF), BP 53, 38041 Grenoble Cedex (France)]. E-mail: guillaumelimousin@yahoo.fr; Gaudet, J.-P. [Laboratoire d' etude des Transferts en Hydrologie et Environnement (CNRS-INPG-IRD-UJF), BP 53, 38041 Grenoble Cedex (France); Charlet, L. [Laboratoire de Geophysique Interne et Techtonophysique - CNRS-IRD-LCPC-UJF-Universite de Savoie, BP 53, 38041 Grenoble Cedex (France); Szenknect, S. [Atomic Energy Commission, Tracers Technology Laboratory, 38054 Grenoble Cedex (France); Barthes, V. [Atomic Energy Commission, Tracers Technology Laboratory, 38054 Grenoble Cedex (France); Krimissa, M. [Electricite de France, Division Recherche et Developpement, Laboratoire National d' Hydraulique et d' Environnement - P78, 6 quai Watier, 78401 Chatou (France)

    2007-02-15

    The retention (or release) of a liquid compound on a solid controls the mobility of many substances in the environment and has been quantified in terms of the 'sorption isotherm'. This paper does not review the different sorption mechanisms. It presents the physical bases underlying the definition of a sorption isotherm, different empirical or mechanistic models, and details several experimental methods to acquire a sorption isotherm. For appropriate measurements and interpretations of isotherm data, this review emphasizes 4 main points: (i) the adsorption (or desorption) isotherm does not provide automatically any information about the reactions involved in the sorption phenomenon. So, mechanistic interpretations must be carefully verified. (ii) Among studies, the range of reaction times is extremely wide and this can lead to misinterpretations regarding the irreversibility of the reaction: a pseudo-hysteresis of the release compared with the retention is often observed. The comparison between the mean characteristic time of the reaction and the mean residence time of the mobile phase in the natural system allows knowing if the studied retention/release phenomenon should be considered as an instantaneous reversible, almost irreversible phenomenon, or if reaction kinetics must be taken into account. (iii) When the concentration of the retained substance is low enough, the composition of the bulk solution remains constant and a single-species isotherm is often sufficient, although it remains strongly dependent on the background medium. At higher concentrations, sorption may be driven by the competition between several species that affect the composition of the bulk solution. (iv) The measurement method has a great influence. Particularly, the background ionic medium, the solid/solution ratio and the use of flow-through or closed reactor are of major importance. The chosen method should balance easy-to-use features and representativity of the studied

  3. Hydrate plugs in subsea pipelines and non-invasive methodology for localization

    OpenAIRE

    Joachim, Sannes

    2013-01-01

    Master's thesis in Offshore technology With the growth in global energy demand and the lack of new shallow-water and onshore opportunities, there is growing emphasis on oil and gas production in deep-water environments. A particular challenge for flow assurance engineers is to ensure pipelines remain free from restrictions created during operation. Hydrate plugging, in particular is, one of the major flow assurance challenge, and as oil and gas production moves into harsh and challengin...

  4. Downhole television (DHTV) applications in borehole plugging

    International Nuclear Information System (INIS)

    Christensen, C.L.; Statler, R.D.; Peterson, E.W.

    1980-05-01

    The Borehole Plugging (BHP) Program is a part of the Sandia experimental program to support the Waste Isolation Pilot Plant (WIPP). The Sandia BHP program is an Office of Nuclear Waste Isolation (ONWI)-funded program designed to provide inputs to the generic plugging program while simultaneously acquiring WIPP-specific data. For this reason a close liaison is maintained between the Sandia WIPP project and the ONWI generic program. Useful technology developed within the Sandia BHP to support WIPP is made available and considered for further development and application to the generic Borehole Plugging and Repository Sealing Program at ONWI. The purpose of this report is to illustrate the usefulness of downhole television (DHTV) observations of a borehole to plan plugging operations. An indication of the wellbore conditions observed is provided. The equipment and setup procedure used in the evaluation of AEC-7 for the Bell Canyon test series are illustrated. A sequence of pictures at various depths as the DHTV rig is lowered through the wellbore is presented. Sample photographs taken with both dry and underwater lamps for illumination are included. The caliper logs for the same depth are included for comparison. General comments are provided on the illustrations

  5. An Overview of the HomePlug AV2 Technology

    Directory of Open Access Journals (Sweden)

    Larry Yonge

    2013-01-01

    Full Text Available HomePlug AV2 is the solution identified by the HomePlug Alliance to achieve the improved data rate performance required by the new generation of multimedia applications without the need to install extra wires. Developed by industry-leading participants in the HomePlug AV Technical Working Group, the HomePlug AV2 technology provides Gigabit-class connection speeds over the existing AC wires within home. It is designed to meet the market demands for the full set of future in-home networking connectivity. Moreover, HomePlug AV2 guarantees backward interoperability with other HomePlug systems. In this paper, the HomePlug AV2 system architecture is introduced and the technical details of the key features at both the PHY and MAC layers are described. The HomePlug AV2 performance is assessed, through simulations reproducing real home scenarios.

  6. Plug-in hybrid electric vehicle R&D plan

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2007-06-01

    FCVT, in consultation with industry and other appropriate DOE offices, developed the Draft Plug-In Hybrid Electric Vehicle R&D Plan to accelerate the development and deployment of technologies critical for plug-in hybrid vehicles.

  7. An optimal design for millimeter-wide facture plugging zone

    Directory of Open Access Journals (Sweden)

    Yili Kang

    2015-01-01

    Full Text Available Lost circulation control in millimeter-wide fractures has been a challenge in well drilling all the time. Low pressure-bearing capacity of a plugging zone will result in excessive consumption of lost circulation materials (LCMs and extra down time. In this study, laboratory experiments were conducted on the plugging of millimeter-wide fractures to evaluate the plugging effects of different types of LCM including rigid granules, elastic particles and fiber. Maximum plugging pressure, total loss volume before sealing and plugging time were taken as the evaluation index of the LCM plugging effect. According to the experimental results, the synergistic plugging mechanisms of different LCM combinations were also analyzed. Experimental results showed that the total loss volume of the plugging zone formed by rigid and elastic particle combination was generally greater than 400 mL, and the maximum plugging pressure of the plugging zone formed by elastic particle and fiber combination was generally less than 6 MPa. In contrast, the plugging zone formed by the combination of the three types of LCMs has the maximum plugging pressure of up to 13 MPa and total loss volume before sealing of 75 mL. In the synergistic plugging process, rigid granules form a frame with high pressure-bearing capacity in the narrower parts of the fractures; elastic particles generate elastic force through elastic deformation to increase the friction between a fracture and a plugging zone to make the plugging zone more stable; fibers filling in the pore space between the particles increase the tightness and integrity of the plugging zone. The experimental results can provide guidance for the optimal design of LCMs used in the field.

  8. Bond strength of cementitious borehole plugs in welded tuff

    International Nuclear Information System (INIS)

    Akgun, H.; Daemen, J.J.K.

    1991-02-01

    Axial loads on plugs or seals in an underground repository due to gas, water pressures and temperature changes induced subsequent to waste and plug emplacement lead to shear stresses at the plug/rock contact. Therefore, the bond between the plug and rock is a critical element for the design and effectiveness of plugs in boreholes, shafts or tunnels. This study includes a systematic investigation of the bond strength of cementitious borehole plugs in welded tuff. Analytical and numerical analysis of borehole plug-rock stress transfer mechanics is performed. The interface strength and deformation are studied as a function of Young's modulus ratio of plug and rock, plug length and rock cylinder outside-to-inside radius ratio. The tensile stresses in and near an axially loaded plug are analyzed. The frictional interface strength of an axially loaded borehole plug, the effect of axial stress and lateral external stress, and thermal effects are also analyzed. Implications for plug design are discussed. The main conclusion is a strong recommendation to design friction plugs in shafts, drifts, tunnels or boreholes with a minimum length to diameter ratio of four. Such a geometrical design will reduce tensile stresses in the plug and in the host rock to a level which should minimize the risk of long-term deterioration caused by excessive tensile stresses. Push-out tests have been used to determine the bond strength by applying an axial load to cement plugs emplaced in boreholes in welded tuff cylinders. A total of 130 push-out tests have been performed as a function of borehole size, plug length, temperature, and degree of saturation of the host tuff. The use of four different borehole radii enables evaluation of size effects. 119 refs., 42 figs., 20 tabs

  9. On intermittent flow characteristics of gas–liquid two-phase flow

    Energy Technology Data Exchange (ETDEWEB)

    Thaker, Jignesh; Banerjee, Jyotirmay, E-mail: jbaner@gmail.com

    2016-12-15

    Highlights: • Unified correlations for intermittent flow characteristics are developed. • Influence of inflow conditions on intermittent flow characteristics is analysed. • Developed correlations can be used for effective design of piping components. - Abstract: Flow visualisation experiments are reported for intermittent regime of gas–liquid two-phase flow. Intermittent flow characteristics, which include plug/slug frequency, liquid plug/slug velocity, liquid plug/slug length, and plug/slug bubble length are determined by image processing of flow patterns captured at a rate of 1600 frames per second (FPS). Flow characteristics are established as a function of inlet superficial velocity of both the phases (in terms of Re{sub SL} and Re{sub SG}). The experimental results are first validated with the existing correlations for slug flow available in literature. It is observed that the correlations proposed in literature for slug flow do not accurately predict the flow characteristics in the plug flow regime. The differences are clearly highlighted in this paper. Based on the measured database for both plug and slug flow regime, modified correlations for the intermittent flow regime are proposed. The correlations reported in the present paper, which also include plug flow characteristics will aid immensely to the effective design and optimization of operating conditions for safer operation of two-phase flow piping systems.

  10. Development and application of microbial selective plugging processes

    Energy Technology Data Exchange (ETDEWEB)

    Jenneman, G.E. [Phillips Petroleum Co., Bartlesville, OK (United States); Gevertz, D.; Davey, M.E. [Agouron Institute, La Jolla, CA (United States)] [and others

    1995-12-31

    Phillips Petroleum Company recently completed a microbial selective plugging (MSP) pilot at the North Burbank Unit (NBU), Shidler, Oklahoma. Nutrients were selected for the pilot that could stimulate indigenous microflora in the reservoir brine to grow and produce exopolymer. It was found that soluble corn starch polymers (e.g., maltodextrins) stimulated the indigenous bacteria to produce exopolymer, whereas simple sugars (e.g., glucose and sucrose), as well as complex media (e.g., molasses and Nutrient Broth), did not. Injection of maltodextrin into rock cores in the presence of indigenous NBU bacteria resulted in stable permeability reductions (> 90%) across the entire length, while injection of glucose resulted only in face plugging. In addition, it was found that organic phosphate esters (OPE) served as a preferable source of phosphorus for the indigenous bacteria, since orthophosphates and condensed phosphates precipitated in NBU brine at reservoir temperature (45{degrees}C). Injection of maltodextrin and ethyl acid phosphate into a producing well stimulated an increase in maltodextrin utilizing bacteria (MUB) in the back-flowed, produced fluid. Additional screens of indigenous and nonindigenous bacteria yielded several nonindigenous isolates that could synthesize polymer when growing in brine containing 6% NaCl at 45{degrees}C.

  11. Room temperature isotherms for Mo and Ni

    International Nuclear Information System (INIS)

    Masse, J.L.

    1986-11-01

    Isotherms at room temperature for Mo and Ni are proposed. They are of three types: BIRCH, KEANE and BORN-MIE. The adjustable constants appearing in these isotherms have been determined from experimental quantities at zero pressure. An evaluation of the limit of (δB T /δP) T as P #-> # ∞, where B T is the isothermal bulk modulus, has been also used. These three isotherms obtained for Mo and Ni are compared with isotherms derived from shock-wave data according to the PRIETO's model. There is a good agreement between these and these derived from shock-wave data. The three isotherms proposed for Mo and Ni can be considered as valid until pressures of several B To , where B To is the bulk modulus B T at P = o [fr

  12. Recent developments in plugging of steam generator tubes

    International Nuclear Information System (INIS)

    Buhay, S.; Abucay, R.C.

    1995-01-01

    Mechanical Plugging capability has been developed for Bruce Nuclear Generating Station (BNGS) steam generator (SG) tubes and Darlington Nuclear Generating Station (DNGS) SG tubes and tubesheet holes. The plug concept was a modified ABB/Combustion Engineering Inconel 690 plug with a nickel band, rolled into the tube or tubesheet hole from the primary side of the tubesheet. The qualification program included analytical justification of the plug body and experimental testing to verify the leak tightness of the rolled joint under conditions which meet or exceed all service or design requirements. Tools and procedures were developed and tested for manual and remote/robotic installation and removal of the mechanical plugs. Additionally, tools and procedures were developed to plug tubes/tubesheet holes at DNGS in the event the steam generator is recalled to service to act as a heat sink. A crew of Ontario Hydro personnel were trained and qualified for the installation of mechanical plugs for permanent and recall applications. During the DNGS Unit 4 spring 1995 outage, 6 tubes were plugged and the 'Recall Plugging Capability' was deployed and ready for use during a primary side SG tube removal. The mechanical plugs were installed manually with a typical 3 minute/plug in-bowl duration time with an average radiation dose of 12.5 mrem per plug. This compares favourably with manual plug welding during the same outage in the same SG bowl at approximately 15-30 minutes/plug in-bowl duration with an average radiation dose of 117 mrem/plug. (author)

  13. Plugging of feed inlet tube upstands with Ni/Ti shape memory alloy plugs - Heysham 1 power station

    International Nuclear Information System (INIS)

    Mathews, A.J.

    1988-01-01

    The paper contains a description of a new approach for Plugging feed inlet tubes of Gas-Cooled Reactors. Instead of utilizing the original explosive method plugging by fitting a shape memory alloy plug into the upstand is being described. (author)

  14. Bubbling and foaming assisted clearing of mucin plugs in microfluidic Y-junctions.

    Science.gov (United States)

    Abdula, Daner; Lerud, Ryan; Rananavare, Shankar

    2017-11-07

    Microfluidic Y-junctions were used to study mechanical mechanisms involved in pig gastric mucin (PGM) plug removal from within one of two bifurcation branches with 2-phase air and liquid flow. Water control experiments showed moderate plug removal due to shear from vortex formation in the blockage branch and suggest a PGM yield stress of 35Pa, as determined by computational fluid dynamics. Addition of hexadecyltrimethylammonium bromide (CTAB) surfactant improved clearing effectiveness due to bubbling in 1mm diameter channels and foaming in 500μm diameter channels. Plug removal mechanisms have been identified as vortex shear, bubble scouring, and then foam scouring as air flow rate is increased with constant liquid flow. The onset of bubbling and foaming is attributed to a flow regime transition from slug to slug-annular. Flow rates explored for 1mm channels are typically experienced by bronchioles in generations 8 and 9 of lungs. Results have implications on treatment of cystic fibrosis and other lung diseases. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Industry perspectives on Plug-& -Play Spacecraft Avionics

    Science.gov (United States)

    Franck, R.; Graven, P.; Liptak, L.

    This paper describes the methodologies and findings from an industry survey of awareness and utility of Spacecraft Plug-& -Play Avionics (SPA). The survey was conducted via interviews, in-person and teleconference, with spacecraft prime contractors and suppliers. It focuses primarily on AFRL's SPA technology development activities but also explores the broader applicability and utility of Plug-& -Play (PnP) architectures for spacecraft. Interviews include large and small suppliers as well as large and small spacecraft prime contractors. Through these “ product marketing” interviews, awareness and attitudes can be assessed, key technical and market barriers can be identified, and opportunities for improvement can be uncovered. Although this effort focuses on a high-level assessment, similar processes can be used to develop business cases and economic models which may be necessary to support investment decisions.

  16. CDF End Plug calorimeter Upgrade Project

    International Nuclear Information System (INIS)

    Apollinari, G.; de Barbaro, P.; Mishina, M.

    1994-01-01

    We report on the status of the CDF End Plug Upgrade Project. In this project, the CDF calorimeters in the end plug and the forward regions will be replaced by a single scintillator based calorimeter. After an extensive R ampersand D effort on the tile/fiber calorimetry, we have now advanced to a construction phase. We review the results of the R ampersand D leading to the final design of the calorimeters and the development of tooling devised for this project. The quality control program of the production of the electromagnetic and hadronic calorimeters is described. A shower maximum detector for the measurement of the shower centroid and the shower profile of electrons, γ and π 0 has been designed. Its performance requirements, R ampersand D results and mechanical design are discussed

  17. Cost estimate for electrostatically plugged cusp reactor

    International Nuclear Information System (INIS)

    Dolan, T.J.

    1977-01-01

    A preliminary design of an electrostatically plugged cusp reactor was presented in (UCRL-52142(1976)). The capital costs of the various components of this reactor are estimated and totaled for two different blanket configurations: one having an energy multiplication factor M = 1.2, and the other having M = 1.68. The unoptimized direct capital costs for these cases are found to be about 1400 and 950 $/kWe, respectively

  18. Borehole plugging by hydrothermal transport. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Roy, D.M.; White, W.B.

    1976-02-28

    Calcium silicate--and aluminosilicate--compositions based on mixtures of fine grained quartz with various cements or calcium silicate compounds have been investigated under hydrothermal conditions in the temperature range 110-250/sup 0/C and pressure range 1,000-10,000 psi, pressures which are always in excess of that required to maintain liquid H/sub 2/O, and approximate the confining pressures which might be anticipated in deep boreholes. All silicate cement combinations investigated produce materials having adequate strength after reaction times of 1 day or longer. The calcium aluminate cement was also adequate with respect to strength but would need to be investigated more extensively for overall properties because of its highly reactive chemistry. The mini-rock cylinder-cement plug hydrothermal experiments in both limestone and sandstone resulted in reasonable magnitudes of bonding strength. The typical shear strength of a hydrothermally treated cement-sandstone plug is 1030 psi, and the compressive strength of the extruded cement plug is 9550 psi. Reactions having a potential for producing calcium carbonate plugs in holes drilled in carbonate rocks were studied. It should be noted that most cements are calcium silicate systems and are chemically compatible with the CaCO/sub 3/ and CaMg(CO/sub 3/)/sub 2/ in the rock walls of the hole. A side benefit from this research is some insight into the suitability of massive carbonate rocks as disposal sites. Carbonate rocks by themselves are highly impermeable, have low exchange capacity, and a low water content--all properties that are desirable in the storage medium. A major drawback is the presence of secondary permeability in the form of solutionally modified joints, fractures, and bedding planes.

  19. Borehole plugging by hydrothermal transport. Final report

    International Nuclear Information System (INIS)

    Roy, D.M.; White, W.B.

    1976-01-01

    Calcium silicate--and aluminosilicate--compositions based on mixtures of fine grained quartz with various cements or calcium silicate compounds have been investigated under hydrothermal conditions in the temperature range 110-250 0 C and pressure range 1,000-10,000 psi, pressures which are always in excess of that required to maintain liquid H 2 O, and approximate the confining pressures which might be anticipated in deep boreholes. All silicate cement combinations investigated produce materials having adequate strength after reaction times of 1 day or longer. The calcium aluminate cement was also adequate with respect to strength but would need to be investigated more extensively for overall properties because of its highly reactive chemistry. The mini-rock cylinder-cement plug hydrothermal experiments in both limestone and sandstone resulted in reasonable magnitudes of bonding strength. The typical shear strength of a hydrothermally treated cement-sandstone plug is 1030 psi, and the compressive strength of the extruded cement plug is 9550 psi. Reactions having a potential for producing calcium carbonate plugs in holes drilled in carbonate rocks were studied. It should be noted that most cements are calcium silicate systems and are chemically compatible with the CaCO 3 and CaMg(CO 3 ) 2 in the rock walls of the hole. A side benefit from this research is some insight into the suitability of massive carbonate rocks as disposal sites. Carbonate rocks by themselves are highly impermeable, have low exchange capacity, and a low water content--all properties that are desirable in the storage medium. A major drawback is the presence of secondary permeability in the form of solutionally modified joints, fractures, and bedding planes

  20. Plug and abandonment operations and tool positioning

    OpenAIRE

    Saad, Idrees

    2014-01-01

    Master's thesis in Petroleum engineering With aging oil fields, the Norwegian petroleum authorities are focusing on Plug and Abandonment (P&A) plans. Therefore efforts are being made, by relevant authorities, to improve standards and procedures for the P&A operations. Regulations for UK part of the North Sea define the P&A operation plans and execution phases in a way that may help improve the standards on the Norwegian Continental Shelf. Halliburton like its competitors is focusing on ...

  1. Development of simplified rotating plug seal structure

    International Nuclear Information System (INIS)

    Ueta, M.; Ichimiya, M.; Kanaoka, T.; Sekiya, H.; Ueda, S.; Ishibashi, S.

    1991-01-01

    We studied a compact and simplified rotating plug seal structure and conducted experiments for key elements of the concept such us the mechanical seal structure and sodium deposit prevention system. Good characteristics were confirmed for the mechanical seal structure, which utilizes an elastomer seal and thin lathe bearing. Applicability of the density barrier concept was also confirmed as the sodium deposit prevention system. This concept can be applied to actual plants. (author)

  2. Ice plugging of pipes using liquid nitrogen

    International Nuclear Information System (INIS)

    Twigg, R.J.

    1987-03-01

    This report presents a study on the ice plugging of pipe using liquid nitrogen, and is based on a literature review and on discussions with individuals who use the technique. Emphasis is placed on ferritic alloys, primarily carbon steels, in pipe sized up to 60 cm in diameter and on austenitic stainless steels in pipe sizes up to 30 cm in diameter. This technique is frequently used for leak testing in nuclear facilities

  3. Borehole Plugging-Materials Development Program

    International Nuclear Information System (INIS)

    Gulick, C.W. Jr.

    1978-06-01

    This report discusses the background and first year's results of the grouting materials development program for plugging boreholes associated with the Nuclear Waste Isolation Pilot Plant. The grouts are to be pumpable, impermeable, and durable for many thousands of years. The work was done at the Concrete Laboratory of the U.S. Army Engineer Waterways Experiment Station (WES), Vicksburg, Mississippi. The workability, strength, porosity, bonding, expansion, and permeability data are summarized and discussed. The work is continuing at WES

  4. Mechanistic Understanding of Microbial Plugging for Improved Sweep Efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Steven Bryant; Larry Britton

    2008-09-30

    Microbial plugging has been proposed as an effective low cost method of permeability reduction. Yet there is a dearth of information on the fundamental processes of microbial growth in porous media, and there are no suitable data to model the process of microbial plugging as it relates to sweep efficiency. To optimize the field implementation, better mechanistic and volumetric understanding of biofilm growth within a porous medium is needed. In particular, the engineering design hinges upon a quantitative relationship between amount of nutrient consumption, amount of growth, and degree of permeability reduction. In this project experiments were conducted to obtain new data to elucidate this relationship. Experiments in heterogeneous (layered) beadpacks showed that microbes could grow preferentially in the high permeability layer. Ultimately this caused flow to be equally divided between high and low permeability layers, precisely the behavior needed for MEOR. Remarkably, classical models of microbial nutrient uptake in batch experiments do not explain the nutrient consumption by the same microbes in flow experiments. We propose a simple extension of classical kinetics to account for the self-limiting consumption of nutrient observed in our experiments, and we outline a modeling approach based on architecture and behavior of biofilms. Such a model would account for the changing trend of nutrient consumption by bacteria with the increasing biomass and the onset of biofilm formation. However no existing model can explain the microbial preference for growth in high permeability regions, nor is there any obvious extension of the model for this observation. An attractive conjecture is that quorum sensing is involved in the heterogeneous bead packs.

  5. Remote Handling behind port plug in ITER

    International Nuclear Information System (INIS)

    Bede, O.; Neuberger, H.

    2006-01-01

    Different Test Blanket Modules (TBM) will be used in succession in the same equatorial ports of ITER. The remote handling operations for connection/disconnection of an interface between the port plug of the EU-HCPB-TBM and the port cell equipment are investigated with the goal to reach a quick and simple TBM exchange procedure. This paper describes the operations and systems which are required for connection of the TBM to its supply lines at this interface. The interface is located inside the free space of the port plug flange between the port plug shield and the bioshield of the port cell behind. The approach of the operation place is only available through a narrow gate in the bioshield opened temporarily during maintenance periods. This gate limits the dimensions of the whole system and its tools. The current design of the EU-HCPB-TBM foresees up to 9 supply lines which have to be connected inside the free space of one half of the port plug flange. The connection operations require positioning and adjustment of the tools for each pipe separately. Despite the strict circumstances it is still possible to find such an industrial jointed-arm robot with sufficient payload, which can penetrate into the working area. A mechanical system is necessary to move the robot from its storing place in the hot cell to the port plug on 6 m distance. Each operation requires different end-of-arm tools. The most special one is a pipe positioner tool, which can position and pull the pipe ends to each other and align the tool before welding and hold them in proper position during the welding process. Weld seams can be made by orbital welding tool. The pipe positioner tool has to provide place for welding tool. Using of inbore tool is impossible because pipes have no open ends where the tool could leave it. Orbital tool must be modified to meet requirements of remote handling because it is designed for human handling. The coolant is helium, so for eliminating the leak of helium it is

  6. THERMODYNAMICS AND ADSORPTION ISOTHERMS FOR THE ...

    African Journals Online (AJOL)

    BAFFA

    data were tested using Freundlich and Langmuir adsorption isotherms. The values of the numeric constants ... Keywords: Adsorbate, Adsorbent, Adsorption isotherms, Maize cob, Thermodynamics. INTRODUCTION. Maize (Zea mays) ... several times with water, air – dried and ground to. 850μm particle size and finally kept ...

  7. Borehole plugging experiment in OL-KR24 at Olkiluoto, Finland

    International Nuclear Information System (INIS)

    Rautio, T.

    2006-04-01

    Sealing of investigation boreholes has been studied by Svensk Koernbroenslehantering AB (SKB) and Posiva Oy (Posiva) as a part of final disposal research. The proposed principle is that investigation boreholes drilled at a site must not act as a continuous flow path for groundwater but be sealed to become as tight as the surrounding rock. As a part of the investigations SKB and Posiva started the third phase of the joint project 'Cleaning and sealing of investigation boreholes' in 2005. One of the sub-projects was the plugging experiment in borehole OL-KR24 at Olkiluoto. The aim of the experiment was to test all main procedures of borehole sealing concept in practise in a deep borehole. Borehole KR24 was drilled to the depth of 551.11 metres in 2003 and it was located inside the shaft profile in Onkalo. From the surface to the depth of about 120 m the borehole diameter is 98 mm. The rest of the borehole is 75.7 mm in diameter. The borehole is vertical and the inclination is quite accurately 90 degrees. The plugging experiment in borehole OL-KR24 consisted of four main activities: (1) cleaning of the borehole, (2) characterization of the borehole (3) selective stabilisation of the borehole, and (4) emplacement of plugs. The comprehensive cleaning of the borehole was to be done in the first stage to provide the basis for other activities. The aim of characterization was to study the borehole in order to determine the sections for selective stabilisation and the locations for plugs. The characterization phase consisted of caliper measurements, dummy probing and optical borehole imaging (OBI). The aim of selective stabilisation was to show that selected borehole sections can be stabilised using new techniques and methods. One borehole section was reamed from Ω 76 mm to Ω 98 mm. The reamed borehole section should have been filled with sufficient amount of cement-based material to achieve a stable 'concrete tube' after redrilling, but due to encountered problems and

  8. Isothermal transitions of a thermosetting system

    Science.gov (United States)

    Gillham, J. K.; Benci, J. A.; Noshay, A.

    1974-01-01

    A study of the curing reactions of a cycloaliphatic epoxy resin/anhydride system by torsional braid analysis showed the existence of two critical isothermal temperatures - namely, the maximum glass transition temperature of the thermoset system and the glass transition temperature of the material at its gel point. Two rheologically active kinetic transitions occur during isothermal cure which correspond to gelation and vitrification. Three types of isothermal behavior occur. Methods for determining the time to gel and the time to vitrify, and also the two above-mentioned critical isothermal temperatures, have been developed. The time to gel obeyed the Arrhenius relationship, whereas the time to vitrify passed through a minimum. Application of these results to thermosetting systems in general is discussed in terms of the influence of molecular structure on the values of the critical isothermal temperatures.

  9. Assessing the Potential of Plug-in Electric Vehicles in Active Distribution Networks

    DEFF Research Database (Denmark)

    Kordheili, Reza Ahmadi; Pourmousavi, Seyyed Ali; Savaghebi, Mehdi

    2016-01-01

    A multi-objective optimization algorithm is proposed in this paper to increase the penetration level of renewable energy sources (RESs) in distribution networks by intelligent management of plug-in electric vehicle (PEV) storage. The proposed algorithm is defined to manage the reverse power flow ...... demonstrate the capability of the algorithm in increasing solar power penetration in the grid up to 50%, depending on the PEV penetration level and the freedom of the system operator in managing the available PEV storage....

  10. A study on stress corrosion cracking of explosive plugged part

    International Nuclear Information System (INIS)

    Kaga, Seiichi; Fujii, Katsuhiro; Yamamoto, Yoshiaki; Sakuma, Koosuke; Hibi, Seiji; Morimoto, Hiroyoshi.

    1986-01-01

    Studies on the stress corrosion cracking of explosive plugged part are conducted. SUS 304 stainless steel is used as testing material. The distribution of residual stress in plug and tube plate after plugging is obtained. The effect of residual stress on the stress corrosion cracking is studied. Residual stress in tube plate near the plug is compressive and stress corrosion cracking dose not occur in the tube plate there, and it occurs on the inner surface of plug because of residual tensile stress in axial direction of the plug. Stress corrosion test in MgCl 2 solution under constant load is conducted. The susceptibility to stress corrosion cracking of the explosive bonded boundary is lower than that of base metal because of greater resistance to plastic deformation. Stress corrosion test in high temperature and high pressure pure water is also conducted by means of static type of autoclave but stress corrosion cracking does not occur under the testing condition used. (author)

  11. Mucous plug syndrome. A pulmonary embolism mimic

    International Nuclear Information System (INIS)

    Bray, S.T.; Johnstone, W.H.; Dee, P.M.; Pope, T.L. Jr.; Teates, C.D.; Tegtmeyer, C.J.

    1984-01-01

    Reported are ten instances of major bronchial obstruction by mucous plugs in eight patients during which the clinical features resembled pulmonary embolism. Perfusion lung studies showed significantly diminished perfusion of the involved portions of the lungs. The chest radiographs generally did not, however, reflect the severity of the airway obstruction and in some instances were completely normal. The ventilation studies indicated the extent and severity of the obstruction and matched with the perfusion scans. Pulmonary arteriograms were performed in three patients and gave direct evidence of focally diminished lung perfusion without embolism. The physiologic mechanisms underlying the condition are discussed

  12. Plug ‘n’ Play with DNA

    DEFF Research Database (Denmark)

    Lund, Anne Mathilde; Andreasen, Elisa W.; Korgaard, Jaide V.

    Synthetic biology has evolved dramatically within the past decade, which calls for a revolution of the Standard Assembly method that makes the foundation of BioBricks. We believe that iGEM should be about fast assembly of BioBricks, where any thinkable part, device or existing BioBrick can be com...... be combined for any type of organism within one day. Therefore, we have designed a new BioBrick Kit based on a novel assembly standard; called “Plug 'n' Play with DNA”....

  13. Thermographic study of the preheating plugs in diesel engines

    OpenAIRE

    Royo Pastor, Rafael; Albertos Arranz, M.A.; CÁRCEL CUBAS, JUAN ANTONIO; Payá Herrero, Jorge

    2012-01-01

    The use of direct injection diesel engines has been widely applied during the past ten years. In such engines, the preheating plugs are a key element which has a significant contribution in the pollutant emissions. In this paper, two different plug designs from Renault are analyzed. The new plug reduces substantially the required electrical consumption. Nevertheless, the pollutant emissions are higher (fundamentally CO and HCs) and hereby a thorough analysis is required to underst...

  14. Diagnostic Devices for Isothermal Nucleic Acid Amplification

    Directory of Open Access Journals (Sweden)

    Chia-Chen Chang

    2012-06-01

    Full Text Available Since the development of the polymerase chain reaction (PCR technique, genomic information has been retrievable from lesser amounts of DNA than previously possible. PCR-based amplifications require high-precision instruments to perform temperature cycling reactions; further, they are cumbersome for routine clinical use. However, the use of isothermal approaches can eliminate many complications associated with thermocycling. The application of diagnostic devices for isothermal DNA amplification has recently been studied extensively. In this paper, we describe the basic concepts of several isothermal amplification approaches and review recent progress in diagnostic device development.

  15. Diagnostic devices for isothermal nucleic acid amplification.

    Science.gov (United States)

    Chang, Chia-Chen; Chen, Chien-Cheng; Wei, Shih-Chung; Lu, Hui-Hsin; Liang, Yang-Hung; Lin, Chii-Wann

    2012-01-01

    Since the development of the polymerase chain reaction (PCR) technique, genomic information has been retrievable from lesser amounts of DNA than previously possible. PCR-based amplifications require high-precision instruments to perform temperature cycling reactions; further, they are cumbersome for routine clinical use. However, the use of isothermal approaches can eliminate many complications associated with thermocycling. The application of diagnostic devices for isothermal DNA amplification has recently been studied extensively. In this paper, we describe the basic concepts of several isothermal amplification approaches and review recent progress in diagnostic device development.

  16. Knowledge-Based System to Support Plug Load Management

    Data.gov (United States)

    National Aeronautics and Space Administration — Electrical plug loads comprise an increasingly larger share of building energy consumption as improvements have been made to Heating, Ventilation, and Air...

  17. Mechanical Properties of Plug Welds after Micro-Jet Cooling

    OpenAIRE

    Hadryś D.

    2016-01-01

    New technology of micro-jet welding could be regarded as a new way to improve mechanical properties of plug welds. The main purpose of that paper was analyzing of mechanical properties of plug welds made by MIG welding method with micro-jet cooling. The main way for it was comparison of plug welds made by MIG welding method with micro-jet cooling and plug welds made by ordinary MIG welding method. It is interesting for steel because higher amount of acicular ferrite (AF) in weld metal deposit...

  18. An Overview of the HomePlug AV2 Technology

    OpenAIRE

    Yonge, Larry; Abad, Jose; Afkhamie, Kaywan; Guerrieri, Lorenzo; Katar, Srinivas; Lioe, Hidayat; Pagani, Pascal; Riva, Raffaele; Schneider, Daniel M.; Schwager, Andreas

    2013-01-01

    HomePlug AV2 is the solution identified by the HomePlug Alliance to achieve the improved data rate performance required by the new generation of multimedia applications without the need to install extra wires. Developed by industry-leading participants in the HomePlug AV Technical Working Group, the HomePlug AV2 technology provides Gigabit-class connection speeds over the existing AC wires within home. It is designed to meet the market demands for the full set of future in-home networking co...

  19. Ford C-Max plug-in hybrid; Ford C-Max mit Plug-in-Hybridtechnik

    Energy Technology Data Exchange (ETDEWEB)

    Schamel, Andreas; D' Annunzio, Julie; Iorio, Rob [Ford Motor Company, Dearborn, MI (United States); Schmitz, Peter [Ford-Forschungszentrum Aachen GmbH, Aachen (Germany)

    2013-03-01

    Ford provides consumers a broad choice of electrified vehicles globally, including full hybrids, plug-in hybrids and all-electric vehicles. The all-new 2013 model year C-Max Energi Plug-in Hybrid utilises the third generation of Ford hybrid technology. This article discusses the hybrid powersplit architecture and components, as well as the charging capability and human-machine interfaces, used in the C-Max Energi Plug-In Hybrid. (orig.)

  20. Deep Space Habitat Wireless Smart Plug

    Science.gov (United States)

    Morgan, Joseph A.; Porter, Jay; Rojdev, Kristina; Carrejo, Daniel B.; Colozza, Anthony J.

    2014-01-01

    NASA has been interested in technology development for deep space exploration, and one avenue of developing these technologies is via the eXploration Habitat (X-Hab) Academic Innovation Challenge. In 2013, NASA's Deep Space Habitat (DSH) project was in need of sensors that could monitor the power consumption of various devices in the habitat with added capability to control the power to these devices for load shedding in emergency situations. Texas A&M University's Electronic Systems Engineering Technology Program (ESET) in conjunction with their Mobile Integrated Solutions Laboratory (MISL) accepted this challenge, and over the course of 2013, several undergraduate students in a Capstone design course developed five wireless DC Smart Plugs for NASA. The wireless DC Smart Plugs developed by Texas A&M in conjunction with NASA's Deep Space Habitat team is a first step in developing wireless instrumentation for future flight hardware. This paper will further discuss the X-Hab challenge and requirements set out by NASA, the detailed design and testing performed by Texas A&M, challenges faced by the team and lessons learned, and potential future work on this design.

  1. Integrated nozzle - flapper valve with piezoelectric actuator and isothermal chamber: a feedback linearization multi control device

    Energy Technology Data Exchange (ETDEWEB)

    Kamali, Mohammadreza; Jazayeri, Seyed Ali [K. N.Toosi University of Technology, Tehran (Iran, Islamic Republic of); Najafi, Farid [University of Guilan, Rasht (Iran, Islamic Republic of); Kawashima, Kenji [Tokyo Medical and Dental University, Tokyo (Japan); Kagawa, Toshiharu [Tokyo Institute of Technology, Tokyo (Japan)

    2016-05-15

    This paper introduces a new nozzle-flapper valve with isothermal chamber using piezoelectric actuator. It controls the pressure and flow rate simply, effectively and separately. The proposed valve uses isothermal chamber presenting practical isothermal condition due to its large heat transfer interfaces filled by metal wool. The valve uses stacked type piezoelectric actuator with unique advantages. By using this valve, a simple method has been fulfilled to control flow rate or pressure of ideal gases in a pneumatic actuators. Experimental results demonstrated applications of the proposed valve to control either pressure or flow rate in pneumatic circuits. This valve can be also used in the pilot stage valve to actuate the main stage of a much bigger pneumatic valve. Designated structure contains only one pressure sensor installed on the isothermal control chamber, capable of controlling both pressure and flow rate. The desired output mass flow rate of the valve is controlled by the pressure changes during positioning of piezoelectric actuator at proper position. The proposed valve can control steady and unsteady oscillatory flow rate and pressure effectively, using nonlinear control method such as feedback linearization approach. Its effectiveness is demonstrated and validated through simulation and experiments.

  2. Initial Clinical Experience Using the Amplatzer Vascular Plug

    International Nuclear Information System (INIS)

    Tuite, David J.; Kessel, David O.; Nicholson, Anthony A.; Patel, Jai V.; McPherson, Simon J.; Shaw, David R.

    2007-01-01

    Background and purpose. The Amplatzer Vascular Plug (AVP) is a self-expanding nitinol wire mesh vascular embolization device derived from the Amplatz septal occluder. We assessed the results of vascular embolization obtained using the AVP. Methods. A retrospective review was carried out of 23 consecutive cases of vascular embolization using the AVP in a variety of different clinical settings. The AVP was chosen to have a diameter approximately 30-50% greater than the target vessel. The device was delivered via an appropriately sized guide catheter and was released when satisfactorily positioned. Additional embolic agents were used in some cases. Results. All target vessels were successfully occluded with no device malpositioning or malfunction. In 14 (61%) patients the AVP was the sole embolic material. In the remaining patients additional agents were used, particularly in preoperative embolization of highly vascular renal tumors. The AVP does not cause instantaneous thrombosis and in high-flow situations thrombosis typically takes up to 15 min. Conclusion. The AVP is a safe, effective embolization device that provides a useful adjunct to the therapeutic armamentarium. It is particularly suited to the treatment of short high-flow vessels where coil migration and catheter dislodgment might occur. In the majority of cases no additional embolic agents are necessary but it may take up to 15 min for complete thrombosis to occur

  3. Model-free method for isothermal and non-isothermal decomposition kinetics analysis of PET sample

    International Nuclear Information System (INIS)

    Saha, B.; Maiti, A.K.; Ghoshal, A.K.

    2006-01-01

    Pyrolysis, one possible alternative to recover valuable products from waste plastics, has recently been the subject of renewed interest. In the present study, the isoconversion methods, i.e., Vyazovkin model-free approach is applied to study non-isothermal decomposition kinetics of waste PET samples using various temperature integral approximations such as Coats and Redfern, Gorbachev, and Agrawal and Sivasubramanian approximation and direct integration (recursive adaptive Simpson quadrature scheme) to analyze the decomposition kinetics. The results show that activation energy (E α ) is a weak but increasing function of conversion (α) in case of non-isothermal decomposition and strong and decreasing function of conversion in case of isothermal decomposition. This indicates possible existence of nucleation, nuclei growth and gas diffusion mechanism during non-isothermal pyrolysis and nucleation and gas diffusion mechanism during isothermal pyrolysis. Optimum E α dependencies on α obtained for non-isothermal data showed similar nature for all the types of temperature integral approximations

  4. Isothermal calorimeter for reactor radiation dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Radak, B; Markovic, V [Institute of Nuclear Sciences Boris Kidric, Odeljenje za radijacionu hemiju, Vinca, Beograd (Serbia and Montenegro)

    1961-12-15

    An isothermal calorimeter with thermistors for measuring absorbed dose rates from 10{sup 4}-5-6.10{sup 5} rad/h in reactor experimental holes has been designed. A kinetics method for determining the equilibrium temperature difference has been developed, and its application in isothermal calorimetry proved. The expected accuracy in measurements within {+-} 2-5% has been proved by measurements carried out in the reactor. Some data obtained by measurements in the reactor RA are presented (author)

  5. Isotherms clustering in cosmic microwave background

    International Nuclear Information System (INIS)

    Bershadskii, A.

    2006-01-01

    Isotherms clustering in cosmic microwave background (CMB) has been studied using the 3-year WMAP data on cosmic microwave background radiation. It is shown that the isotherms clustering could be produced by the baryon-photon fluid turbulence in the last scattering surface. The Taylor-microscale Reynolds number of the turbulence is estimated directly from the CMB data as Re λ ∼10 2

  6. Intraprocedural Safety and Technical Success of the MVP Micro Vascular Plug for Embolization of Pulmonary Arteriovenous Malformations.

    Science.gov (United States)

    Conrad, Miles B; Ishaque, Brandon M; Surman, Andrew M; Kerlan, Robert K; Hope, Michael D; Dickey, Melissa A; Hetts, Steven W; Wilson, Mark W

    2015-11-01

    This case series describes early experience, intraprocedural safety, and technical success of the MVP Micro Vascular Plug (MVP; Covidien, Irvine, California) for embolization of 20 pulmonary arteriovenous malformations (PAVMs) using 23 plugs in seven patients with hereditary hemorrhagic telangiectasia. There was no device migration, and all devices were successfully detached electrolytically. Immediate cessation of flow through the feeding artery was achieved in 21 of 23 (91%) deployments. There was one minor complication. This series demonstrates the MVP to be safe and technically successful in the treatment of PAVMs. Copyright © 2015 SIR. Published by Elsevier Inc. All rights reserved.

  7. Miniaturized isothermal nucleic acid amplification, a review.

    Science.gov (United States)

    Asiello, Peter J; Baeumner, Antje J

    2011-04-21

    Micro-Total Analysis Systems (µTAS) for use in on-site rapid detection of DNA or RNA are increasingly being developed. Here, amplification of the target sequence is key to increasing sensitivity, enabling single-cell and few-copy nucleic acid detection. The several advantages to miniaturizing amplification reactions and coupling them with sample preparation and detection on the same chip are well known and include fewer manual steps, preventing contamination, and significantly reducing the volume of expensive reagents. To-date, the majority of miniaturized systems for nucleic acid analysis have used the polymerase chain reaction (PCR) for amplification and those systems are covered in previous reviews. This review provides a thorough overview of miniaturized analysis systems using alternatives to PCR, specifically isothermal amplification reactions. With no need for thermal cycling, isothermal microsystems can be designed to be simple and low-energy consuming and therefore may outperform PCR in portable, battery-operated detection systems in the future. The main isothermal methods as miniaturized systems reviewed here include nucleic acid sequence-based amplification (NASBA), loop-mediated isothermal amplification (LAMP), helicase-dependent amplification (HDA), rolling circle amplification (RCA), and strand displacement amplification (SDA). Also, important design criteria for the miniaturized devices are discussed. Finally, the potential of miniaturization of some new isothermal methods such as the exponential amplification reaction (EXPAR), isothermal and chimeric primer-initiated amplification of nucleic acids (ICANs), signal-mediated amplification of RNA technology (SMART) and others is presented.

  8. A study on development of a plugging margin evaluation method taking into account the fouling of shell-and tube heat exchangers

    International Nuclear Information System (INIS)

    Hwang, Kyeong Mo; Jin, Tae Eun; Kim, Kyung Hoon

    2006-01-01

    As the operating time of heat exchangers progresses, fouling caused by water-borne deposits and the number of plugged tubes increase and thermal performance decreases. Both fouling and tube plugging are known to interfere with normal flow characteristics and to reduce thermal efficiencies of heat exchangers. The heat exchangers of Korean nuclear power plants have been analyzed in terms of heat transfer rate and overall heat transfer coefficient as a means of heat exchanger management. Except for fouling resulting from the operation of heat exchangers, all the tubes of heat exchangers have been replaced when the number of plugged tubes exceeded the plugging criteria based on design performance sheet. This paper describes a plugging margin evaluation method taking into account the fouling of shell-and-tube heat exchangers. The method can evaluate thermal performance, estimate future fouling variation, and consider current fouling level in the calculation of plugging margin. To identify the effectiveness of the developed method, fouling and plugging margin evaluations were performed at a component cooling heat exchanger in a Korean nuclear power plant

  9. Preliminary Plugging tests in Narrow Sodium Channels by Sodium and Carbon Dioxide reaction

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sun Hee; Wi, Myung-Hwan; Min, Jae Hong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    This report is on the investigation of the physical/chemical phenomena that a slow loss of CO{sub 2} inventory into sodium after the sodium-CO{sub 2} boundary failure in PCHEs in realistic operating conditions. The first phenomenon is potential channel plugging inside the narrow PCHE channel. Unlike a conventional shell and- tube type HXs, failures in a PCHE are expected to be small cracks. If the faulted channel is blocked, it may have a positive function for plant safety because the pressure boundary would automatically recover due to this self-plugging. The other one is damage propagation on pressure boundary, which is referred to as potential wastage with combined corrosion/erosion effect. Physical/chemical phenomena that a slow loss of CO{sub 2} inventory into sodium after the sodium-CO{sub 2} boundary failure in printed circuit heat exchangers (PCHEs) were investigated. Our preliminary experimental results of plugging show that sodium flow immediately stopped as CO{sub 2} was injected through the nozzle at 300-400 .deg. C in 3 mm sodium channels, whereas sodium flow stopped about 60 min after CO{sub 2} injection in 5 mm sodium channels.

  10. Developing quality standards for physical properties of mineral wool plugs

    NARCIS (Netherlands)

    Blok, C.; Berg, van den C.C.; Winkel, van A.

    2014-01-01

    The KIWA certification guidelines for mineral wool products contain standards for slabs and blocks. Propagators would like to introduce quality standards for mineral wool plugs as well. Main concerns were effects of too dense plugs on plant growth, and handling problems with too fluffy or broken

  11. Plug and Play Process Control of a District Heating System

    DEFF Research Database (Denmark)

    Trangbaek, Klaus; Knudsen, Torben; Skovmose Kallesøe, Carsten

    2009-01-01

    The main idea of plug and play process control is to initialise and reconfigure control systems automatically. In this paper these ideas are applied to a scaled laboratory model of a district heating pressure control system.  First of all this serves as a concrete example of plug and play control...

  12. Capillarity Induced Negative Pressure of Water Plugs in Nanochannels

    NARCIS (Netherlands)

    Tas, Niels Roelof; Mela, P.; Kramer, Tobias; Berenschot, Johan W.; van den Berg, Albert

    2003-01-01

    We have found evidence that water plugs in hydrophilic nanochannels can be at significant negative pressure due to tensile capillary forces. The negative pressure of water plugs in nanochannels induces bending of the thin channel capping layer, which results in a visible curvature of the liquid

  13. Plug-in hybrid electric vehicles in dynamical energy markets

    NARCIS (Netherlands)

    Kessels, J.T.B.A.; Bosch, P.P.J. van den

    2008-01-01

    The plug-in hybrid electric vehicle allows vehicle propulsion from multiple internal power sources. Electric energy from the grid can be utilized by means of the plug-in connection. An on-line energy management (EM) strategy is proposed to minimize the costs for taking energy from each power source.

  14. Analyzing the Risk of Well Plug Failure after Abandonment

    International Nuclear Information System (INIS)

    Mainguy, M.; Longuemare, P.; Audibert, A.; Lecolier, E.

    2007-01-01

    All oil and gas wells will have to be plugged and abandoned at some time. The plugging and abandonment procedure must provide an effective isolation of the well fluids all along the well to reduce environmental risks of contamination and prevent from costly remedial jobs. Previous works have analyzed the plug behavior when submitted to local pressure or thermal changes but no work has looked to the effects of external pressure, thermal and stress changes resulting from a global equilibrium restoration in a hydrocarbon reservoir once production has stopped. This work estimates those changes after abandonment on a reservoir field case using a reservoir simulator in conjunction with a geomechanical simulator. Such simulations provide the pressure and thermal changes and the maximum effective stress changes in the reservoir cap rock where critical plugs are put in place for isolating the production intervals. These changes are used as loads in a well bore stress model that explicitly models an injector well and predict stress rearrangements in the plug after abandonment. Results obtained with the well bore stress model for a conventional class G cement plug show that the main risk of failure is tensile failure because of the low tensile strength of the cement. Actually, soft sealing materials or initially pre-stressed plug appears to be more adapted to the downhole conditions changes that may occurs after well plugging and abandonment. (authors)

  15. Dual Spark Plugs For Stratified-Charge Rotary Engine

    Science.gov (United States)

    Abraham, John; Bracco, Frediano V.

    1996-01-01

    Fuel efficiency of stratified-charge, rotary, internal-combustion engine increased by improved design featuring dual spark plugs. Second spark plug ignites fuel on upstream side of main fuel injector; enabling faster burning and more nearly complete utilization of fuel.

  16. California Statewide Plug-In Electric Vehicle Infrastructure Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Melaina, Marc; Helwig, Michael

    2014-05-01

    The California Statewide Plug-In Electric Vehicle Infrastructure Assessment conveys to interested parties the Energy Commission’s conclusions, recommendations, and intentions with respect to plug-in electric vehicle (PEV) infrastructure development. There are several relatively low-risk and high-priority electric vehicle supply equipment (EVSE) deployment options that will encourage PEV sales and

  17. National Plug-In Electric Vehicle Infrastructure Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Wood, Eric [National Renewable Energy Lab. (NREL), Golden, CO (United States); Rames, Clement [National Renewable Energy Lab. (NREL), Golden, CO (United States); Muratori, Matteo [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2017-09-15

    This report addresses the fundamental question of how much plug-in electric vehicle (PEV) charging infrastructure—also known as electric vehicle supply equipment (EVSE)—is needed in the United States to support both plug-in hybrid electric vehicles (PHEVs) and battery electric vehicles (BEVs).

  18. Eddy current inspection of steam generator tubing plugs

    International Nuclear Information System (INIS)

    Cullen, W.K.

    1990-01-01

    In response to the issues raised regarding the integrity of nuclear steam generator tubing plugs manufactured from certain heats of Inconel 600, Westinghouse engineers have developed, qualified and implemented an eddy current inspection system for the in-place assessment of these plugs. The heart of the system is a robotic and effector which delivers an eddy current sensor through the reduced diameter of the plug expander and actuates the coil to physical contact with the expanded inside bore of the plug. Once deployed, the eddy current sensor is rotated along a helical path to produce a detailed scan of the plug surface above the final position of the expander. This testing produces an isometric display of degradation due to primary water stress corrosion cracking, on the inside surface of the plug. To date, successful inspections have been conducted at two nuclear units with two different robotic delivery systems. While designed specifically for mechanical plugs with a bottle bore cavity, the inspection system can also be used for expanded straight bore plugs. Details of the inspection system along with a discussion of qualification activities and actual field results are presented in this paper

  19. Conceptual design on structure and cooling channel of ITER upper port plug

    International Nuclear Information System (INIS)

    Pak, Sunil; Lee, Hyeon Gon; Jung, Ki Jung; Walker, C.; Kim, Doo Gi; Choi, Kwang Suk; Eo, Sang Gon

    2007-01-01

    This study has performed conceptual design on structure and cooling channel for the upper port plug of the International Thermonuclear Experimental Reactor (ITER), in which electron cyclotron heating (ECH) launcher and various diagnostic modules will be installed with the same structure. There are twelve diagnostic plugs and four ECH plugs at the upper port in ITER Tokamak. The use of the same port plug structure is beneficial for installation of diagnostic modules and ECH launcher from the viewpoint of cost reduction and simple RH maintenance. The diagnostic modules have rectangular cross-section and ECH modules have trapezoidal crosssection with the lower part wider. Here was suggested the bolt-jointed common structure of inverted-U shape beam and bottom plate, where the diagnostic and ECH modules are installed onto the bottom plate and then the assembly is bolted to the inverted-U beam from the bottom. The common structure of Inverted-U type was evaluated by considering several aspects, such as installation, remote handling (RH) maintenance, cooling line connection, manufacturing, and structural stiffness. For the inverted-U port plug structure developed here, this paper proposed a network of water channel for cooling and baking. Pressurized water as working fluid has to be supplied into the whole port plug. It consists of the structure, diagnostic/shielding modules fixed onto the bottom plate, and the blanket shield module (BSM) attached to the front. The internal water ways for these three components were designed in the direction that would not only minimize the RH connections, flow restrictors, and the length of water-vacuum welding, but also make the welding reliable. Independent coolant loops were composed for three parts of the structure, BSM, and diagnostic/shielding modules with bottom plate. These loops, therefore, make it possible to perform the leakage test for each one separately. Finally hydraulic analysis has been performed with ANSYS in order to

  20. Development of the Simulation Program for the In-Vessel Fuel Handling System of Double Rotating Plug Type

    International Nuclear Information System (INIS)

    Kim, S. H.; Kim, J. B.

    2011-01-01

    In-vessel fuel handling machines are the main equipment of the in-vessel fuel handling system, which can move the core assembly inside the reactor vessel along with the rotating plug during refueling. The in vessel fuel handling machines for an advanced sodium cooled fast reactor(SFR) demonstration plant are composed of a direct lift machine(DM) and a fixed arm machine(FM). These machines should be able to access all areas above the reactor core by means of the rotating combination of double rotating plugs. Thus, in the in vessel fuel handling system of the double rotating plug type, it is necessary to decide the rotating plug size and evaluate the accessibility of in-vessel fuel handling machines in given core configuration. In this study, the simulation program based on LABVIEW which can effectively perform the arrangement design of the in vessel fuel handling system and simulate the rotating plug motion was developed. Fig. 1 shows the flow chart of the simulation program

  1. Proceedings of the workshop on borehole and shaft plugging

    International Nuclear Information System (INIS)

    1980-01-01

    Geologic disposal of radioactive waste relies on the capability of many geological formations to provide long-term containment of the waste. The disposal operations could significantly modify the original conditions. In addition to the underground excavations and the thermal input of the waste their is the problem of boreholes and shafts that constitute a potential by-pass of the geological barriers. It is therefore essential to develop techniques and procedures for effective plugging of all penetrations connecting the disposal zone with the surface or with water bearing layers. It will be necessary to produce plugs which effectively restore the original characteristics of the isolating formations. In addition these plugs must be chemically stable in the existing geochemical environment in order to remain effective for very long periods of time and the plugs of disposal holes can be exposed to high temperatures and radiation doses. All countries with geologic disposal programmes will have to face the problem of borehole and shapt plugging

  2. Development of sealing plug for sweep gas line

    International Nuclear Information System (INIS)

    Kikuchi, Taiji; Yamada, Hirokazu; Saitoh, Takashi; Nakamichi, Masaru; Tsuchiya, Kunihiko; Kawamura, Hiroshi

    2004-03-01

    On the irradiation capsule for neutron irradiation test of the tritium breeder, the sealing plug is necessary to prevent a leak of tritium gas when the tritium breeder is picked up from the irradiation capsule after irradiation test. However, the general valve and plug cannot apply to sealing of the sweep gas line because of the following factors, the neutron irradiation effect, limited space in the irradiation capsule, high sealing efficiency, simple method and operation for control. Therefore, the sealing plug for sweep gas line has to be developed. This paper reports the development of the sealing plug for sweep gas line and the operating procedure of the sealing plug in the irradiation capsule. (author)

  3. A Genre Classification Plug-in for Data Collection

    DEFF Research Database (Denmark)

    Lehn-Schiøler, Tue; Arenas-García, Jerónimo; Petersen, Kaare Brandt

    2006-01-01

    This demonstration illustrates how the methods developed in the MIR community can be used to provide real-time feedback to music users. By creating a genre classifier plug-in for a popular media player we present users with relevant information as they play their songs. The plug-in can furthermor...... be used as a data collection platform. After informed consent from a selected set of users the plug-in will report on music consumption behavior back to a central server.......This demonstration illustrates how the methods developed in the MIR community can be used to provide real-time feedback to music users. By creating a genre classifier plug-in for a popular media player we present users with relevant information as they play their songs. The plug-in can furthermore...

  4. Borehole plugging by compaction process. Final report

    International Nuclear Information System (INIS)

    Fernandez, R.; MacGowan, C.; Nolan, E.; Morey, R.; Palty, A.

    1976-08-01

    The requirements of an overall program to preserve the integrity of a repository formation are documented. The repository is intended to be in stable earth stratum used as a safe and permanent storage area for nuclear waste material. These wastes represent an environmental hazard for a period of up to 200,000 years. An engineering analysis, a reliability and quality-assurance program, and a development program for borehole plugging by compaction process, using natural earthen materials, are presented. Part 1 provides the engineering analysis of downhole compaction methods and related instrumentation along with a recommended development plan from concept through a pilot in-situ experiment. Part 2 provides a reliability and quality-assurance program from laboratory testing of materials through an in-situ experiment

  5. Plugging criteria for WWER SG tubes

    Energy Technology Data Exchange (ETDEWEB)

    Papp, L.; Wilam, M. [Vitkovice NPP Services (Switzerland); Herman, M. [Vuje, Trnava (Slovakia)

    1997-12-31

    At operated Czech and Slovak nuclear power plants the 80 % criteria for crack or other bulk defect depth is used for steam generator heat exchanging tubes plugging. This criteria was accepted as the recommendation of designer of WWER steam generators. Verification of this criteria was the objective of experimental program performed by Vitkovice, J.S.C., UJV Rez, J.S.C. and Vuje Trnava, J.S.C .. Within this program the following factors were studied: (1) Influence of secondary water chemistry on defects initiation and propagation, (2) Statistical evaluation of corrosion defects progression at operated SG, and (3) Determination of critical pressure for tube rupture as a function of eddy current indications. In this presentation items (2) and (3) are considered.

  6. Welding nuclear reactor fuel rod end plugs

    International Nuclear Information System (INIS)

    Yeo, D.

    1984-01-01

    Apparatus for applying a vacuum to a nuclear fuel rod cladding tube's interior through its open end while girth welding an inserted end plug to its other end. An airtight housing has an orifice with a seal which can hermetically engage the tube's open end. A vacuum hose has one end connected to the housing and the other end connected to a vacuum pump. A mechanized device which moves the housing to engage or disengage its seal with the tube's open end includes at least one arm having one end attached to the housing and the other end pivotally attached to a movable table; an arm rotating device to coaxially align the housing's orifice with the welding-positioned tube; and a table moving device to engage the seal of the coaxially aligned orifice with the tube's open end. (author)

  7. Experimental plug and play quantum coin flipping

    Science.gov (United States)

    Pappa, Anna; Jouguet, Paul; Lawson, Thomas; Chailloux, André; Legré, Matthieu; Trinkler, Patrick; Kerenidis, Iordanis; Diamanti, Eleni

    2014-04-01

    Performing complex cryptographic tasks will be an essential element in future quantum communication networks. These tasks are based on a handful of fundamental primitives, such as coin flipping, where two distrustful parties wish to agree on a randomly generated bit. Although it is known that quantum versions of these primitives can offer information-theoretic security advantages with respect to classical protocols, a demonstration of such an advantage in a practical communication scenario has remained elusive. Here we experimentally implement a quantum coin flipping protocol that performs strictly better than classically possible over a distance suitable for communication over metropolitan area optical networks. The implementation is based on a practical plug and play system, developed by significantly enhancing a commercial quantum key distribution device. Moreover, we provide combined quantum coin flipping protocols that are almost perfectly secure against bounded adversaries. Our results offer a useful toolbox for future secure quantum communications.

  8. Plugging criteria for WWER SG tubes

    Energy Technology Data Exchange (ETDEWEB)

    Papp, L; Wilam, M [Vitkovice NPP Services (Switzerland); Herman, M [Vuje, Trnava (Slovakia)

    1998-12-31

    At operated Czech and Slovak nuclear power plants the 80 % criteria for crack or other bulk defect depth is used for steam generator heat exchanging tubes plugging. This criteria was accepted as the recommendation of designer of WWER steam generators. Verification of this criteria was the objective of experimental program performed by Vitkovice, J.S.C., UJV Rez, J.S.C. and Vuje Trnava, J.S.C .. Within this program the following factors were studied: (1) Influence of secondary water chemistry on defects initiation and propagation, (2) Statistical evaluation of corrosion defects progression at operated SG, and (3) Determination of critical pressure for tube rupture as a function of eddy current indications. In this presentation items (2) and (3) are considered.

  9. Strategies for Controlling Plug Loads. A Tool for Reducing Plug Loads in Commercial Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Torcellini, Paul [National Renewable Energy Lab. (NREL), Golden, CO (United States); Bonnema, Eric [National Renewable Energy Lab. (NREL), Golden, CO (United States); Sheppy, Michael [National Renewable Energy Lab. (NREL), Golden, CO (United States); Pless, Shanti [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-09-01

    Plug loads are often not considered as part of the energy savings measures in Commercial Buildings; however, they can account for up to 50% of the energy used in the building. These loads are numerous and often scattered throughout a building. Some of these loads are purchased by the owner and some designed into the building or the tenant finishes for a space. This document provides a strategy and a tool for minimizing these loads.

  10. Cloud computing-based energy optimization control framework for plug-in hybrid electric bus

    International Nuclear Information System (INIS)

    Yang, Chao; Li, Liang; You, Sixiong; Yan, Bingjie; Du, Xian

    2017-01-01

    Considering the complicated characteristics of traffic flow in city bus route and the nonlinear vehicle dynamics, optimal energy management integrated with clustering and recognition of driving conditions in plug-in hybrid electric bus is still a challenging problem. Motivated by this issue, this paper presents an innovative energy optimization control framework based on the cloud computing for plug-in hybrid electric bus. This framework, which includes offline part and online part, can realize the driving conditions clustering in offline part, and the energy management in online part. In offline part, utilizing the operating data transferred from a bus to the remote monitoring center, K-means algorithm is adopted to cluster the driving conditions, and then Markov probability transfer matrixes are generated to predict the possible operating demand of the bus driver. Next in online part, the current driving condition is real-time identified by a well-trained support vector machine, and Markov chains-based driving behaviors are accordingly selected. With the stochastic inputs, stochastic receding horizon control method is adopted to obtain the optimized energy management of hybrid powertrain. Simulations and hardware-in-loop test are carried out with the real-world city bus route, and the results show that the presented strategy could greatly improve the vehicle fuel economy, and as the traffic flow data feedback increases, the fuel consumption of every plug-in hybrid electric bus running in a specific bus route tends to be a stable minimum. - Highlights: • Cloud computing-based energy optimization control framework is proposed. • Driving cycles are clustered into 6 types by K-means algorithm. • Support vector machine is employed to realize the online recognition of driving condition. • Stochastic receding horizon control-based energy management strategy is designed for plug-in hybrid electric bus. • The proposed framework is verified by simulation and hard

  11. Modeling of Experimental Adsorption Isotherm Data

    Directory of Open Access Journals (Sweden)

    Xunjun Chen

    2015-01-01

    Full Text Available Adsorption is considered to be one of the most effective technologies widely used in global environmental protection areas. Modeling of experimental adsorption isotherm data is an essential way for predicting the mechanisms of adsorption, which will lead to an improvement in the area of adsorption science. In this paper, we employed three isotherm models, namely: Langmuir, Freundlich, and Dubinin-Radushkevich to correlate four sets of experimental adsorption isotherm data, which were obtained by batch tests in lab. The linearized and non-linearized isotherm models were compared and discussed. In order to determine the best fit isotherm model, the correlation coefficient (r2 and standard errors (S.E. for each parameter were used to evaluate the data. The modeling results showed that non-linear Langmuir model could fit the data better than others, with relatively higher r2 values and smaller S.E. The linear Langmuir model had the highest value of r2, however, the maximum adsorption capacities estimated from linear Langmuir model were deviated from the experimental data.

  12. Evaluation of preconceptual plug designs using experts' judgement

    International Nuclear Information System (INIS)

    Sioshansi, F.P.; O'Rourke, J.E.

    1980-03-01

    A number of preconceptual plug designs for an underground nuclear waste repository were to be evaluated based on the available information on plug materials and placement techniques. Because of complex environment and loading conditions, long time frame under consideration, rigid performance characteristics and considerable uncertainties present in preconceptual design and material properties, a qualitative and judgmental evaluation procedure was needed to supplement technical studies. A structured procedure was developed to qualitatively capture evaluator's views and reservations on the proposed preconceptual schemes. Since a thorough evaluation of each proposed plug scheme required in-depth experience and familiarity with many components of the plug, three knowledgeable experts with specialties in the most relevant aspects of the problem were independently interviewed. Each plug scheme was broken down into three subcomponents and each subcomponent was evaluated separately. The proposed schemes were then rated taking their subcomponents into consideration. Because the experts had different specialties, their subcomponent and overall ratings were not in full agreement. Each plug scheme's lowest overall rating was used as the most significant determinant of the judgmental preference categories reported in this study. The approach used discriminated between the proposed schemes for those with highest probability of being successful. The most preferred schemes were then reviewed with respect to the data produced in the technical analysis performed during the project. The results of the judgmental analysis were then synthesized and modified with results of the technical analysis to produce the preconceptual plug designs

  13. Development of weld plugging for steam generator tubes of FBR

    International Nuclear Information System (INIS)

    Shimoyama, T.; Matsuyama, T.; Matsumoto, O.; Nagura, Y.; Nakamura, H.; Tohguchi, Y.; Kurokawa, M.; Fukada, T.

    2002-01-01

    This study was undertaken to develop a method of weld plugging of the heat-exchanger tubes of steam generator of Prototype FBR 'MONJU' in case these tubes are damaged for some reason. We studied mainly the shape of plug, welding procedure and effect of postweld heat treatment (PWHT). Evaporator tube sheet, tube and plug are made of 2-1/4Cr-1Mo steel and usually preheating and PWHT will be required for welding of this steel. The results of this study is as follows. 1) Plug was designed to make butt joint welding with grooved tube sheet around the tube hole to satisfy the requirements of plug designing, stress analysis, and good weldability. 2) TIG welding process was selected and certified its good weldability and good performance. 3) PWHT can be done by using high frequency induction heating method locally and also designing the plug to weld joint with tube sheet which was grooved around the tube hole. 4) Mock up test was done and it was certified that this plugging procedure has good weldability and good performance ability for Non Destructive Inspection. (author)

  14. Borehole plugging by hydrothermal transport. A feasibility report

    International Nuclear Information System (INIS)

    Roy, D.M.; White, W.B.

    1975-01-01

    The possibility of forming borehole plugs by hydrothermal transport was examined with respect to five systems, utilizing available literature data. In general, it would appear possible to create plugs with hydrothermal cements, with hydrothermally transported quartz, and with carbonates precipitated in-situ using carbon dioxide or carbon dioxide and water as reacting fluids. Hydrothermal cements appear to be most feasible from an engineering and economic point of view using a slurry with a lime-alumina-silica composition carried into the hole in a single pipe at temperatures in the range of 200 0 C and requiring only enough pressure to drive the mixture into the hole. Quartz or chalcedony plugs would be the most impervious, have the lowest chemical reactivity with groundwater, the lowest thermal expansion, and be most compatible with the wall rock. Deposition is likely to be slow, and there are severe engineering problems associated with a single pipe system carrying silica-rich solutions at temperatures in excess of 500 0 C at pressure of 2000 bars (30,000 psi). Calcite plugs could be formed as compatible plug materials in contact with a limestone or dolomite wall rock. It is not known whether non-porous plugs can be readily formed and there is also a problem of chemical reaction with percolating groundwater. The clay-water and sulfur-water systems do not appear to be viable plug systems. In-situ reconstitution of the wall rock does not appear to be an economically feasible possibility

  15. Final design of ITER port plug test facility

    Energy Technology Data Exchange (ETDEWEB)

    Cerisier, Thierry, E-mail: thierry.cerisier@yahoo.fr [ITER Organization, Route de Vinon-sur-Verdon, CS 90046, St Paul-lez-Durance Cedex, 13067 (France); Levesy, Bruno [ITER Organization, Route de Vinon-sur-Verdon, CS 90046, St Paul-lez-Durance Cedex, 13067 (France); Romannikov, Alexander [Institution “Project Center ITER”, Kurchatov sq. 1, Building 3, Moscow 123182 (Russian Federation); Rumyantsev, Yuri [JSC “Cryogenmash”, Moscow reg., Balashikha 143907 (Russian Federation); Cordier, Jean-Jacques; Dammann, Alexis [ITER Organization, Route de Vinon-sur-Verdon, CS 90046, St Paul-lez-Durance Cedex, 13067 (France); Minakov, Victor; Rosales, Natalya; Mitrofanova, Elena [JSC “Cryogenmash”, Moscow reg., Balashikha 143907 (Russian Federation); Portone, Sergey; Mironova, Ekaterina [Institution “Project Center ITER”, Kurchatov sq. 1, Building 3, Moscow 123182 (Russian Federation)

    2016-11-01

    Highlights: • We introduce the port plug test facility (purpose and status of the design). • We present the PPTF sub-systems. • We present the environmental and functional tests. • We present the occupational and nuclear safety functions. • We conclude on the achievements and next steps. - Abstract: To achieve the overall ITER machine availability target, the availability of diagnostics and heating port plugs shall be as high as 99.5%. To fulfill this requirement, it is mandatory to test the port plugs at operating temperature before installation on the machine and after refurbishment. The ITER port plug test facility (PPTF) is composed of several test stands that can be used to test the port plugs whereas at the end of manufacturing (in a non-nuclear environment), or after refurbishment in the ITER hot cell facility. The PPTF provides the possibility to perform environmental (leak tightness, vacuum and thermo-hydraulic performances) and functional tests (radio frequency acceptance tests, behavior of the plugs’ steering mechanism and calibration of diagnostics) on upper and equatorial port plugs. The final design of the port plug test facility is described. The configuration of the standalone test stands and the integration in the hot cell facility are presented.

  16. Maintenance and plugging technology for CANDU steam generator tubing

    International Nuclear Information System (INIS)

    Prince, J.; Nicholson, A.; Hare, J.; McGoey, L.; Stafford, T.; Gowthorpe, P.

    2006-01-01

    In order to keep aging steam generators in service and to successfully manage the life of these critical components, the capability must exist to perform tube plugging and other complex maintenance activities in-situ. In the early days of CANDU steam generator operation, the only option was to perform these activities manually, which had inherent safety and quality risks. The challenge was to be able to perform these activities remotely thus eliminating some of the confined space and radiological exposure risks. The additional challenge was to develop equipment and techniques which would result in significantly improved quality, particularly for the completed plug welds which would be returned to service. Over the past fifteen years, this technology has matured and has produced remarkable results in field application. Some 14000 tube plugs have been successfully installed to date using automated plugging techniques. This paper presents an overview of the development of techniques available to utilities for steam generator tube plugging as well as some highlights of other steam generator tube maintenance activities such as primary side tube removal and tube end damage repair. Aspects covered in the paper include plug and procedure development, automated equipment and manipulators for tool deployment, process controls and personnel requirements. Recently, the steam generator tube plugging performed by OPG has been incorporated into a formal quality program under the requirements of ASME NCA 4000. An overview of the quality program will be presented and details of some of the important aspects of the quality program will be discussed. (author)

  17. Relativistic sonic geometry for isothermal accretion in the Kerr metric

    Science.gov (United States)

    Arif Shaikh, Md

    2018-03-01

    We linearly perturb advective isothermal transonic accretion onto rotating astrophysical black holes to study the emergence of the relativistic acoustic spacetime and to investigate how the salient features of this spacetime is influenced by the spin angular momentum of the black hole. We have perturbed three different quantities—the velocity potential, the mass accretion rate and the relativistic Bernoulli’s constant to show that the acoustic metric obtained for these three cases are the same up to a conformal factor. By constructing the required causal structures, it has been demonstrated that the acoustic black holes are formed at the transonic points of the flow and the acoustic white holes are formed at the shock location. The corresponding acoustic surface gravity has been computed in terms of the relevant accretion variables and the background metric elements. We have performed a linear stability analysis of the background stationary flow.

  18. Mechanical and thermo-mechanical analyses of the tapered plug for plugging of deposition tunnels. A feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Faelth, Billy (Clay Technology AB, Lund (Sweden)); Gatter, Patrik (Vattenfall Power Consultant AB, Stockholm (Sweden))

    2009-09-15

    This report presents results from a study that was carried out in order to examine the applicability of the tapered plug concept for plugging of deposition tunnels in the deep repository for spent nuclear fuel. The report presents results from mechanical and thermo-mechanical models of the tapered plug. The models were analyzed with 3DEC. The models included a portion of a deposition tunnel and its intersection with a main tunnel. In the deposition tunnel, a tapered concrete plug was installed. The plug was subjected to the combined load from the swelling backfill material and from pore pressure inside the deposition tunnel. The thermo-mechanical effects due to the heat generation in the spent fuel were also included in the analyses. Generic material parameter values for the concrete were used. The following items were studied: - Stresses and displacements in the plug. - Shear stresses and shear displacements in the rock-concrete interface. - Stress additions in the rock due to the loads. The sensitivity of the results to changes of constitutive models, to changes of the plug geometry and to pore water pressure in the rock-concrete interface was examined. The results indicate that the displacements in the plug will be within reasonable ranges but the stresses may locally be high enough that they exceed acceptable levels. However, they can be reduced by choice of advantageous plug geometry and by having a good rock-concrete bond. The results also show that the stress additions in the rock due to the thermal load may yield stresses that locally exceed the spalling strength of the rock. At most locations, however, the rock stresses will amount at lower levels. It was concluded that, with choice of an appropriate design, the tapered plug seems to be an applicable concept for plugging of deposition tunnels. It was also concluded that further studies of the tapered plug concept should use material properties parameter values for low-pH concrete. Further, they should also

  19. Adsorption isotherms of pear at several temperatures

    OpenAIRE

    Mitrevski Vangelče; Lutovska Monika; Mijakovski Vladimir; Pavkov Ivan S.; Babić Mirko M.; Radojčin Milivoje T.

    2015-01-01

    The moisture adsorption isotherms of pear were determined at 15ºC, 30ºC and 45ºC using the standard static gravimetric method over a range of water activity from 0.112 to 0.920. The experimental data were fitted with isotherm equations recommended in ASAE Standard D245.5. In order to find which equation gives the best results, large number of numerical experiments were performed. After that, several statistical criteria proposed in scientific literature for...

  20. DEMO port plug design and integration studies

    Science.gov (United States)

    Grossetti, G.; Boccaccini, L. V.; Cismondi, F.; Del Nevo, A.; Fischer, U.; Franke, T.; Granucci, G.; Hernández, F.; Mozzillo, R.; Strauß, D.; Tran, M. Q.; Vaccaro, A.; Villari, R.

    2017-11-01

    The EUROfusion Consortium established in 2014 and composed by European Fusion Laboratories, and in particular the Power Plant Physics and Technology department aims to develop a conceptual design for the Fusion DEMOnstration Power Plant, DEMO. With respect to present experimental machines and ITER, the main goals of DEMO are to produce electricity continuously for a period of about 2 h, with a net electrical power output of a few hundreds of MW, and to allow tritium self-sufficient breeding with an adequately high margin in order to guarantee its planned operational schedule, including all planned maintenance intervals. This will eliminate the need to import tritium fuel from external sources during operations. In order to achieve these goals, extensive engineering efforts as well as physics studies are required to develop a design that can ensure a high level of plant reliability and availability. In particular, interfaces between systems must be addressed at a very early phase of the project, in order to proceed consistently. In this paper we present a preliminary design and integration study, based on physics assessments for the EU DEMO1 Baseline 2015 with an aspect ratio of 3.1 and 18 toroidal field coils, for the DEMO port plugs. These aim to host systems like electron cyclotron heating launchers currently developed within the Work Package Heating and Current Drive that need an external radial access to the plasma and through in-vessel systems like the breeder blanket. A similar approach shown here could be in principle followed by other systems, e.g. other heating and current drive systems or diagnostics. The work addresses the interfaces between the port plug and the blanket considering the helium-cooled pebble bed and the water cooled lithium lead which are two of four breeding blanket concepts under investigation in Europe within the Power Plant Physics and Technology Programme: the required openings will be evaluated in terms of their impact onto the

  1. The viscoelastic properties of the cervical mucus plug

    DEFF Research Database (Denmark)

    Kjær Bastholm, Sara; Becher, Naja; Stubbe, Peter Reimer

    2013-01-01

    The objective of this study was to characterize the viscoelastic properties of cervical mucus plugs (CMPs) shed during labor at term. Spontaneously shed cervical mucus plugs from healthy women in active labor, were tested. The viscoelastic properties of cervical mucus plugs were investigated...... with using frequency and stress sweep experiments within the linear viscoelastic region. Random-effects regression was used for statistical analysis. The CMPs are solid-like viscoelastic structures and the elastic modulus dominated the viscous modulus at all frequencies. These rheological characteristics...

  2. Modelling isothermal fission gas release

    International Nuclear Information System (INIS)

    Uffelen, P. van

    2002-01-01

    The present paper presents a new fission gas release model consisting of two coupled modules. The first module treats the behaviour of the fission gas atoms in spherical grains with a distribution of grain sizes. This module considers single atom diffusion, trapping and fission induced re-solution of gas atoms associated with intragranular bubbles, and re-solution from the grain boundary into a few layers adjacent to the grain face. The second module considers the transport of the fission gas atoms along the grain boundaries. Four mechanisms are incorporated: diffusion controlled precipitation of gas atoms into bubbles, grain boundary bubble sweeping, re-solution of gas atoms into the adjacent grains and gas flow through open porosity when grain boundary bubbles are interconnected. The interconnection of the intergranular bubbles is affected both by the fraction of the grain face occupied by the cavities and by the balance between the bubble internal pressure and the hydrostatic pressure surrounding the bubbles. The model is under validation. In a first step, some numerical routines have been tested by means of analytic solutions. In a second step, the fission gas release model has been coupled with the FTEMP2 code of the Halden Reactor Project for the temperature distribution in the pellets. A parametric study of some steady-state irradiations and one power ramp have been simulated successfully. In particular, the Halden threshold for fission gas release and two simplified FUMEX cases have been computed and are summarised. (author)

  3. HEPA-filter smoke plugging problem

    International Nuclear Information System (INIS)

    Gaskill, J.R.; Magee, M.W.

    1975-01-01

    Actual experiences indicate that during the early stages of a fire, pyrolysis and incomplete combustion of organic materials used in the furnishings or interior finishes of laboratories yield copious quantities of smoke particulates, both liquid and solid. Furthermore, the use of fire retardants in materials used for the above purpose interferes with the combustion process, so that burning of such materials in later stages of a fire will yield dense smoke. These particulates can plug up a HEPA filter or even a more porous prefilter, and thus effectively shut off the exhaust ventilation. In this case, the fire room will pressurize and contamination may spread in an uncontrolled manner. Both small- and large-scale tests have been conducted to evaluate the nature and degree of the problem as a function of materials involved, rate of exposure to the fire, and kinds and temperatures of smoke so generated. Some test work has also been done on scrubbing of smoke. Proposed future work is described. (U.S.)

  4. Insights into head-column field-amplified sample stacking: Part II. Study of the behavior of the electrophoretic system after electrokinetic injection of cationic compounds across a short water plug.

    Science.gov (United States)

    Šesták, Jozef; Thormann, Wolfgang

    2017-08-25

    Part I on head-column field-amplified sample stacking comprised a detailed study of the electrokinetic injection of a weak base across a short water plug into a phosphate buffer at low pH. The water plug is converted into a low conductive acidic zone and cationic analytes become stacked at the interface between this and a newly formed phosphoric acid zone. The fundamentals of electrokinetic processes occurring thereafter were studied experimentally and with computer simulation and are presented as part II. The configuration analyzed represents a discontinuous buffer system. Computer simulation revealed that the phosphoric acid zone at the plug-buffer interface becomes converted into a migrating phosphate buffer plug which corresponds to the cationically migrating system zone of the phosphate buffer system. Its mobility is higher than that of the analytes such that they migrate behind the system zone in a phosphate buffer comparable to the applied background electrolyte. The temporal behaviour of the current and the conductivity across the water plug were monitored and found to reflect the changes in the low conductivity plug. Determination of the buffer flow in the capillary revealed increased pumping caused by the mismatch of electroosmosis within the low conductivity plug and the buffer. This effect becomes elevated with increasing water plug length. For plug lengths up to 1% of the total column length the flow quickly drops to the electroosmotic flow of the buffer and simulations with experimentally determined current and flow values predict negligible band dispersion and no loss of resolution for both low and large molecular mass components. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Diffuse boundary extraction of breast masses on ultrasound by leak plugging

    International Nuclear Information System (INIS)

    Cary, T.W.; Conant, E.F.; Arger, P.H.; Sehgal, C.M.

    2005-01-01

    We propose a semiautomated seeded boundary extraction algorithm that delineates diffuse region boundaries by finding and plugging their leaks. The algorithm not only extracts boundaries that are partially diffuse, but in the process finds and quantifies those parts of the boundary that are diffuse, computing local sharpness measurements for possible use in computer-aided diagnosis. The method treats a manually drawn seed region as a wellspring of pixel 'fluid' that flows from the seed out towards the boundary. At indistinct or porous sections of the boundary, the growing region will leak into surrounding tissue. By changing the size of structuring elements used for growing, the algorithm changes leak properties. Since larger elements cannot leak as far from the seed, they produce compact, less detailed boundary approximations; conversely, growing from smaller elements results in less constrained boundaries with more local detail. This implementation of the leak plugging algorithm decrements the radius of structuring disks and then compares the regions grown from them as they increase in both area and boundary detail. Leaks are identified if the outflows between grown regions are large compared to the areas of the disks. The boundary is plugged by masking out leaked pixels, and the process continues until one-pixel-radius resolution. When tested against manual delineation on scans of 40 benign masses and 40 malignant tumors, the plugged boundaries overlapped and correlated well in area with manual tracings, with mean overlap of 0.69 and area correlation R 2 of 0.86, but the algorithm's results were more reproducible

  6. Study on the isothermal forging process of MB26 magnesium alloy adaptor

    Directory of Open Access Journals (Sweden)

    Xu Wenchen

    2015-01-01

    Full Text Available The isothermal forging process is an effective method to manufacture complex-shaped components of hard-to-work materials, such as magnesium alloys. This study investigates the isothermal forging process of an MB26 magnesium alloy adaptor with three branches. The results show that two-step forging process is appropriate to form the adaptor forging, which not only improves the filling quality but also reduces the forging load compared with one-step forging process. Moreover, the flow line is distributed along the contour of the complex-shaped adaptor forging.

  7. Sequence crystallization during isotherm evaporation of southern ...

    African Journals Online (AJOL)

    Southern Algerian's natural brine sampled from chott Baghdad may be a source of mineral salts with a high economic value. These salts are recoverable by simple solar evaporation. Indeed, during isothermal solar evaporation, it is possible to recover mineral salts and to determine the precipitation sequences of different ...

  8. THERMODYNAMICS AND ADSORPTION ISOTHERMS FOR THE ...

    African Journals Online (AJOL)

    BAFFA

    The use of maize (Zea mays) cob for the biosorption of Cr(VI), Ni(II) and Cd(II) is ... Variations in the concentration of the different adsorbates during the adsorption process .... Langmuir isotherm is the dimensionless separation .... The use of Sago waste for the sorption of lead and copper. Water S. Afr., 24 (3), p251-256.

  9. Isothermal Titration Calorimetry in the Student Laboratory

    Science.gov (United States)

    Wadso, Lars; Li, Yujing; Li, Xi

    2011-01-01

    Isothermal titration calorimetry (ITC) is the measurement of the heat produced by the stepwise addition of one substance to another. It is a common experimental technique, for example, in pharmaceutical science, to measure equilibrium constants and reaction enthalpies. We describe a stirring device and an injection pump that can be used with a…

  10. Isothermal Gravitational Segregation: Algorithms and Specifications

    DEFF Research Database (Denmark)

    Halldórsson, Snorri; Stenby, Erling Halfdan

    2000-01-01

    New algorithms for calculating the isothermal equilibrium state of reservoir fluids under the influence of gravity are presented. Two types of specifications are considered: the specification of pressure and composition at a reference depth; and the specification of the total overall content of t...

  11. Mechanical Properties of Plug Welds after Micro-Jet Cooling

    Directory of Open Access Journals (Sweden)

    Hadryś D.

    2016-12-01

    Full Text Available New technology of micro-jet welding could be regarded as a new way to improve mechanical properties of plug welds. The main purpose of that paper was analyzing of mechanical properties of plug welds made by MIG welding method with micro-jet cooling. The main way for it was comparison of plug welds made by MIG welding method with micro-jet cooling and plug welds made by ordinary MIG welding method. It is interesting for steel because higher amount of acicular ferrite (AF in weld metal deposit (WMD is obtained in MIG welding method with micro-jet cooling in relation to ordinary MIG welding method. This article presents the influence of the cooling medium and the number of micro-jet streams on mechanical properties of the welded joint. Mechanical properties were described by force which is necessary to destroy weld joint.

  12. Waste isolation pilot plant (WIPP) borehole plugging program description

    International Nuclear Information System (INIS)

    Christensen, C.L.; Hunter, T.O.

    1979-08-01

    The tests and experiments described attempt to provide a mix of borehole (with limited access) and in-mine (with relatively unlimited access) environments in which assessment of the various issues involved can be undertaken. The Bell Canyon Test provides the opportunity to instrument and analyze a plug in a high pressure region. The Shallow Hole Test permits application of best techniques for plugging and then access to both the top and bottom of the plug for further analysis. The Diagnostic Test Hole permits recovery of bench scale size samples for analysis and establishes an in-borehole laboratory in which to conduct testing and analysis in all strata from the surface into the salt horizon. The additional in mine experiments provide the opportunity to investigate in more detail specific effects on plugs in the salt region and allows evaluation of instrumentation systems

  13. Rotary plug device for use in LMFBR type reactors

    International Nuclear Information System (INIS)

    Azuma, Kazuhiko; Imayoshi, Sho.

    1988-01-01

    Purpose: To prevent adhesion of sodium in the rotational gap of a rotational plug. Constitution: One of the walls of a cylindrical gap formed between the outer circumference of a small rotary plug and a large rotary plug that constitute a double rotary plug is cooled to lower than the sodium coagulation temperature, while a stater of a linear motor in a cylindrical shape and wound with linear coils around the iron core is attached to the inside of the other of the walls. Then, one of the walls of the gap to which sodium adheres is cooled to less than sodium coagulation temperature, so that sodium is or tends to be deposited to the wall. Then, eddy currents are resulted to sodium by the current supplied to the stater of the linear motor attached to the other of the walls, to produce thrusting force. Sodium on the wall surface is scraped off by this. (Yoshihara, H.)

  14. Application of Inductive Monitoring System to Plug Load Anomaly Detection

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA Ames Research Center’s Sustainability Base is a new 50,000 sq. ft. LEED Platinum office building. Plug loads are expected to account for a significant portion...

  15. Modular, Plug and Play, Distributed Avionics, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of this SBIR effort was to prove the viability of an Ethernet version of the MicroSat Systems, Inc. (MSI) modular, plug and play (PnP) spacecraft...

  16. Setting plug & abandonment barriers with minimum removal of tubulars

    OpenAIRE

    Nessa, Jon Olav

    2012-01-01

    Master's thesis in Petroleum engineering The useful life of an offshore well is determined by the reserves which it contacts, the pressure support within the reservoir and the continued integrity of the wellbore. When a well has reached the end of its lifetime, plugging operations have to be conducted before permanent abandonment. Conventional Plug and Abandonment (P&A) operations will often require removing a section of the casing in order to create cross sectional barriers for well aband...

  17. Engineering activities on the ITER representative diagnostic equatorial port plug

    International Nuclear Information System (INIS)

    Meunier, L.; Doceul, L.; Salasca, S.; Martins, J.-P.; Jullien, F.; Dechelle, Christian; Bidaud, Pierre; Pilard, Vincent; Terra, Alexis; Ogea, Mathieu; Ciattaglia, Emanuela; Walker, Christopher

    2009-01-01

    Most of ITER diagnostic systems are integrated in port plugs, which are water cooled stainless steel structures inserted into the vacuum vessel ports. The port plug must provide basic functions such as neutron and gamma shielding, supporting the first wall armour (BSM), closing the vacuum vessel ports, while supporting the diagnostic equipments. ITER diagnostic port plug must resist a severe environment like high temperature due to neutron interaction with the structures and high electromechanical loading during disruptions events. CEA has contributed to the design and integration tasks in the frame of the representative equatorial port plug EQ no. 01, in particular on the engineering, structural and thermal finite element analysis. These detailed analyses have highlighted some design issues which were worked out through different solutions. This paper contains a description of the engineering activities performed such as: -The static mechanical calculations of the top plate closure system under disruption load. -The static mechanical calculations of the BSM attachment to the port plug. These two first studies led to design changes proposals which significantly improved the behaviour of the structures but also showed that the safety margin with respect to design limits is quite low. -The design of a Diagnostic Shield Module (DSM) integrated inside the port plug and a proposition of attachment scheme, with respect to disruption loads. The manufacturing of the DSM has been taken into account, as well as diagnostic integration inside the structure and maintenance aspects. -The thermal assessment of the port plug under neutronic load during normal operation, with the optimization of the cooling system. The maximum temperature calculated in normal operation has been reduced from 900 deg. C to less than 400 deg. C in the front plate; and the cooling arrangement at the back of the port plug has been simplified without important temperature increase.

  18. Engineering activities on the ITER representative diagnostic equatorial port plug

    Energy Technology Data Exchange (ETDEWEB)

    Meunier, L. [Association Euratom CEA, CEA/DSM/IRFM (France)], E-mail: lmeunier@cea.fr; Doceul, L.; Salasca, S.; Martins, J.-P.; Jullien, F.; Dechelle, Christian; Bidaud, Pierre; Pilard, Vincent; Terra, Alexis; Ogea, Mathieu [Association Euratom CEA, CEA/DSM/IRFM (France); Ciattaglia, Emanuela [EFDA CSU, Garching (Germany); Walker, Christopher [ITER International Organisation (France)

    2009-06-15

    Most of ITER diagnostic systems are integrated in port plugs, which are water cooled stainless steel structures inserted into the vacuum vessel ports. The port plug must provide basic functions such as neutron and gamma shielding, supporting the first wall armour (BSM), closing the vacuum vessel ports, while supporting the diagnostic equipments. ITER diagnostic port plug must resist a severe environment like high temperature due to neutron interaction with the structures and high electromechanical loading during disruptions events. CEA has contributed to the design and integration tasks in the frame of the representative equatorial port plug EQ no. 01, in particular on the engineering, structural and thermal finite element analysis. These detailed analyses have highlighted some design issues which were worked out through different solutions. This paper contains a description of the engineering activities performed such as: -The static mechanical calculations of the top plate closure system under disruption load. -The static mechanical calculations of the BSM attachment to the port plug. These two first studies led to design changes proposals which significantly improved the behaviour of the structures but also showed that the safety margin with respect to design limits is quite low. -The design of a Diagnostic Shield Module (DSM) integrated inside the port plug and a proposition of attachment scheme, with respect to disruption loads. The manufacturing of the DSM has been taken into account, as well as diagnostic integration inside the structure and maintenance aspects. -The thermal assessment of the port plug under neutronic load during normal operation, with the optimization of the cooling system. The maximum temperature calculated in normal operation has been reduced from 900 deg. C to less than 400 deg. C in the front plate; and the cooling arrangement at the back of the port plug has been simplified without important temperature increase.

  19. Nanosatellite and Plug-and-Play Architecture 2 (NAPA 2)

    Science.gov (United States)

    2017-02-28

    development of a 6U- format Space Plug-and-play Architecture (SPA) Research Cubesat (SPARC). SPARC-1 (first and only pursued under this PA) demonstrates...development of a six unit (6U)- format Space Plug-and-play Architecture (SPA) Research Cubesat (SPARC). SPARC-1 (first and only pursued under this PA...computers – More capable, more centralized, bigger wiring bundle Elimination of central computers, distribution of intelligence in systems Rad- hard

  20. Motion of liquid plugs between vapor bubbles in capillary tubes: a comparison between fluids

    Science.gov (United States)

    Bertossi, Rémi; Ayel, Vincent; Mehta, Balkrishna; Romestant, Cyril; Bertin, Yves; Khandekar, Sameer

    2017-11-01

    Pulsating heat pipes (PHP) are now well-known devices in which liquid/vapor slug flow oscillates in a capillary tube wound between hot and cold sources. In this context, this paper focuses on the motion of the liquid plug, trapped between vapor bubbles, moving in capillary tubes, to try to better understand the thermo-physical phenomena involved in such devices. This study is divided into three parts. In the first part, an experimental study presents the evolution of the vapor pressure during the evaporation process of a liquid thin film deposited from a liquid plug flowing in a heated capillary tube: it is found that the behavior of the generated and removed vapor can be very different, according to the thermophysical properties of the fluids. In the second part, a transient model allows to compare, in terms of pressure and duration, the motion of a constant-length liquid plug trapped between two bubbles subjected to a constant difference of vapor pressure: the results highlight that the performances of the four fluids are also very different. Finally, a third model that can be considered as an improvement of the second one, is also presented: here, the liquid slug is surrounded by two vapor bubbles, one subjected to evaporation, the pressure in both bubbles is now a result of the calculation. This model still allows comparing the behaviors of the fluid. Even if our models are quite far from a complete model of a real PHP, results do indicate towards the applicability of different fluids as suitable working fluids for PHPs, particularly in terms of the flow instabilities which they generate.

  1. Coronal Loops: Evolving Beyond the Isothermal Approximation

    Science.gov (United States)

    Schmelz, J. T.; Cirtain, J. W.; Allen, J. D.

    2002-05-01

    Are coronal loops isothermal? A controversy over this question has arisen recently because different investigators using different techniques have obtained very different answers. Analysis of SOHO-EIT and TRACE data using narrowband filter ratios to obtain temperature maps has produced several key publications that suggest that coronal loops may be isothermal. We have constructed a multi-thermal distribution for several pixels along a relatively isolated coronal loop on the southwest limb of the solar disk using spectral line data from SOHO-CDS taken on 1998 Apr 20. These distributions are clearly inconsistent with isothermal plasma along either the line of sight or the length of the loop, and suggested rather that the temperature increases from the footpoints to the loop top. We speculated originally that these differences could be attributed to pixel size -- CDS pixels are larger, and more `contaminating' material would be expected along the line of sight. To test this idea, we used CDS iron line ratios from our data set to mimic the isothermal results from the narrowband filter instruments. These ratios indicated that the temperature gradient along the loop was flat, despite the fact that a more complete analysis of the same data showed this result to be false! The CDS pixel size was not the cause of the discrepancy; rather, the problem lies with the isothermal approximation used in EIT and TRACE analysis. These results should serve as a strong warning to anyone using this simplistic method to obtain temperature. This warning is echoed on the EIT web page: ``Danger! Enter at your own risk!'' In other words, values for temperature may be found, but they may have nothing to do with physical reality. Solar physics research at the University of Memphis is supported by NASA grant NAG5-9783. This research was funded in part by the NASA/TRACE MODA grant for Montana State University.

  2. Electric and Plug-In Hybrid Electric Fleet Vehicle Testing | Transportation

    Science.gov (United States)

    Research | NREL Electric and Plug-In Hybrid Electric Fleet Vehicle Evaluations Electric and Plug-In Hybrid Electric Fleet Vehicle Evaluations How Electric and Plug-In Hybrid Electric Vehicles plugging the vehicle into an electric power source. PHEVs are powered by an internal combustion engine that

  3. Reconstitutable control assembly having removable control rods with detachable split upper end plugs

    International Nuclear Information System (INIS)

    Gjertsen, R.K.; Knott, R.P.; Sparrow, J.A.

    1991-01-01

    This patent describes, for use in facilitating replacement of a neutron absorber control rod on a control assembly spider structure, an end plug. It comprises a pair of separate upper and lower plug portions; the upper section of the upper plug portion being configured for rigid attachment; the middle section of the upper plug portion having angularly displaced flat surfaces formed on the exterior

  4. Numerical simulation of ion confinement in the Phaedrus plugs

    International Nuclear Information System (INIS)

    Horne, S.F.

    1984-01-01

    Neutral beams of up to 60 amps were injected into the plugs of the tandem mirror Phaedrus. Substantial heating of the target RF-sustained plasma has been observed, but fueling has been negligible. In order to understand the lack of significant fueling, a model of the trapping and loss processes occurring in the Phaedrus plug was developed, and is presented in this thesis. The model includes neutral beam effects, RF trapping, Coulomb losses, and charge exchange on background gas, in a framework which includes finite gyro-orbit effects. A numerical simulation based on the model is compared to data from 2XIIB and TMX, and shows good agreement. The model is then applied to the Phaedrus plugs, and compared to RF-sustained and neutral-beam data obtained during machine operation in hydrogen and deuterium. The modeling of the Phaedrus plugs indicates that during beam injection, a two-step process occurs that results in the rapid loss of ions. Charge exchange of trapped plasma on the energetic neutral beam causes rapid radial diffusion of the plasma, which then charge exchanges on the background gas, or is lost to the limiter. Because this is a finite gyro-orbit effect, increasing the plug magnetic field should improve the net beam fueling by reducing this diffusion. Results from the model indicate that increasing the plug midplane field from 2600 to 4000 gauss will improve the beam fueling significantly

  5. Experimental study of natural convection adjacent to an isothermal vertical ice cylinder in cold pure water

    International Nuclear Information System (INIS)

    Riu, Kap Jong; Yea, Yong Taeg; Park, Sang Hee

    1991-01-01

    A natural convection adjacent to an isothermal vertical ice cylinder is studied experimentally in cold pure water. The experiments are carried out as changing the temperature of the ambient water and then the flow and heat transfer characteristics is visualized and observed. It is shown that flow patterns are steady state upflow, unsteady state flow, steady state dual flow, and steady state downflow. There is also obtained a heat transfer coefficient and mean Nusselt number at various ambient temperature. These results are in good agreement with the theoretical ones. (Author)

  6. Determination of the Darcy permeability of porous media including sintered metal plugs

    Science.gov (United States)

    Frederking, T. H. K.; Hepler, W. A.; Yuan, S. W. K.; Feng, W. F.

    1986-01-01

    Sintered-metal porous plugs with a normal size of the order of 1-10 microns are used to evaluate the Darcy permeability of laminar flow at very small velocities in laminar fluids. Porous media experiment results and data adduced from the literature are noted to support the Darcy law analog for normal fluid convection in the laminar regime. Low temperature results suggest the importance of collecting room temperature data prior to runs at liquid He(4) temperatures. The characteristic length diagram gives a useful picture of the tolerance range encountered with a particular class of porous media.

  7. Isothermal Kinetics of Catalyzed Air Oxidation of Diesel Soot

    Directory of Open Access Journals (Sweden)

    R. Prasad

    2011-01-01

    Full Text Available To comply with the stringent emission regulations on soot, diesel vehicles manufacturers more and more commonly use diesel particulate filters (DPF. These systems need to be regenerated periodically by burning soot that has been accumulated during the loading of the DPF. Design of the DPF requires rate of soot oxidation. This paper describes the kinetics of catalytic oxidation of diesel soot with air under isothermal conditions. Kinetics data were collected in a specially designed mini-semi-batch reactor. Under the high air flow rate assuming pseudo first order reaction the activation energy of soot oxidation was found to be, Ea = 160 kJ/ mol. ©2010 BCREC UNDIP. All rights reserved(Received: 14th June 2010, Revised: 18th July 2010, Accepted: 9th August 2010[How to Cite: R. Prasad, V.R. Bella. (2010. Isothermal Kinetics of Catalyzed Air Oxidation of Diesel Soot. Bulletin of Chemical Reaction Engineering and Catalysis, 5(2: 95-101. doi:10.9767/bcrec.5.2.796.95-101][DOI:http://dx.doi.org/10.9767/bcrec.5.2.796.95-101 || or local:  http://ejournal.undip.ac.id/index.php/bcrec/article/view/796]Cited by in: ACS 1 |

  8. Isothermal reaction calorimetry as a tool for kinetic analysis

    International Nuclear Information System (INIS)

    Zogg, Andreas; Stoessel, Francis; Fischer, Ulrich; Hungerbuehler, Konrad

    2004-01-01

    Reaction calorimetry has found widespread application for thermal and kinetic analysis of chemical reactions in the context of thermal process safety as well as process development. This paper reviews the most important reaction calorimetric principles (heat-flow, heat-balance, power-compensation, and Peltier principle) and their applications in commercial or scientific devices. The discussion focuses on the different dynamic behavior of the main calorimetric principles during an isothermal reaction measurement. Examples of available reaction calorimeters are further compared considering their detection limit, time constant as well as temperature range. In a second part, different evaluation methods for the isothermally measured calorimetric data are reviewed and discussed. The methods will be compared, focusing especially on the fact that reaction calorimetric data always contains additional informations not directly related to the actual chemical reaction such as heat of mixing, heat of phase-transfer/change processes or simple measurement errors. Depending on the evaluation method applied such disturbances have a significant influence on the calculated reaction enthalpies or rate constants

  9. Mathematical modelling of non-isothermal venturi scrubbers

    Energy Technology Data Exchange (ETDEWEB)

    Rahimi, A. [Isfahan Univ., Isfahan (Iran, Islamic Republic of). Dept. of Chemical Engineering; Taheri, M.; Fathikakajahi, J. [Shiraz Univ., Shiraz (Iran, Islamic Republic of). Dept. of Chemical Engineering

    2005-06-01

    Venturi scrubbers collect gaseous pollutants and particulate matter from industrial exhaust. This air pollution control device is highly efficient, easy to maintain and has a low initial cost. However, the high pressure drop through the device results in a high running cost. The main mechanism for collecting particulates is the inertial impaction of the particles on the droplets, which occurs due to high velocity between the gas stream and droplets. Droplet acceleration and irreversible drag-force which results from this high relative velocity are responsible for the high pressure drop in this type of scrubber. While several attempts have been made to mathematically model particulate removal in Venturi scrubbers, most models do not consider simultaneous heat and mass transfer. This factor is important because most Venturi scrubbers operate under non-isothermal conditions where the inlet gas is humidified in order to cool it before entering the scrubber. For that reason, the authors developed a more realistic model to determine the effects of heat and mass transfer on the particulate removal efficiency of a non-isothermal Venturi type scrubber. The model considers the effect of droplet size distribution and liquid film flow on the walls. It consists of differential equations for energy, momentum and material exchange. Model results were compared with data from experimental studies and industrial facilities. It was concluded that the removal efficiency of the scrubber is influenced by the inlet humidity temperature of the inlet gas. 26 refs., 1 tab., 10 figs.

  10. Reliable prediction of adsorption isotherms via genetic algorithm molecular simulation.

    Science.gov (United States)

    LoftiKatooli, L; Shahsavand, A

    2017-01-01

    Conventional molecular simulation techniques such as grand canonical Monte Carlo (GCMC) strictly rely on purely random search inside the simulation box for predicting the adsorption isotherms. This blind search is usually extremely time demanding for providing a faithful approximation of the real isotherm and in some cases may lead to non-optimal solutions. A novel approach is presented in this article which does not use any of the classical steps of the standard GCMC method, such as displacement, insertation, and removal. The new approach is based on the well-known genetic algorithm to find the optimal configuration for adsorption of any adsorbate on a structured adsorbent under prevailing pressure and temperature. The proposed approach considers the molecular simulation problem as a global optimization challenge. A detailed flow chart of our so-called genetic algorithm molecular simulation (GAMS) method is presented, which is entirely different from traditions molecular simulation approaches. Three real case studies (for adsorption of CO 2 and H 2 over various zeolites) are borrowed from literature to clearly illustrate the superior performances of the proposed method over the standard GCMC technique. For the present method, the average absolute values of percentage errors are around 11% (RHO-H 2 ), 5% (CHA-CO 2 ), and 16% (BEA-CO 2 ), while they were about 70%, 15%, and 40% for the standard GCMC technique, respectively.

  11. Complex anal fistulas: plug or flap?

    Science.gov (United States)

    Muhlmann, Mark D; Hayes, Julian L; Merrie, Arend E H; Parry, Bryan R; Bissett, Ian P

    2011-10-01

    Rectal mucosal advancement flaps (RMAF) and fistula plugs (FP) are techniques used to manage complex anal fistulas. The purpose of this study was to review and compare the results of these methods of repair. A retrospective review of all complex anal fistulas treated by either a RMAF or a FP at Auckland City Hospital from 2004 to 2008. Comparisons were made in terms of successful healing rates, time to failure and the use of magnetic resonance imaging. Overall, 70 operations were performed on 55 patients (55.7% male). The mean age was 44.9 years. Twenty-one patients (30%) had had at least one previous unsuccessful repair. Indications for repair included 57 high cryptoglandular anal (81%), 4 Crohn's anal (6%), 7 rectovaginal (10%), 1 rectourethral (1%) and 1 pouch-vaginal fistula (1%). All patients were followed up with a mean of 4.5 months. Forty-eight RMAFs (69% of total) were performed with 16 successful repairs (33%). Twenty-two FPs (31% of total) were performed with 7 successful repairs (32%, P = 0.9). In failed repairs, there was no difference in terms of mean time to failure (RMAF 4.8 months versus FP 4.1 months, P = 0.62). Magnetic resonance imaging was performed in 21 patients (37%) before the repair. The success rate in these patients was 20%. The results of treatment of complex anal fistulas are disappointing. The choice of operation of either a RMAF or a FP did not alter the poor healing rates of about one third of patients in each group.

  12. Fuel string supporting shield plug (f3sp) for Ontario Hydro - Bruce NGSA

    Energy Technology Data Exchange (ETDEWEB)

    Henry, P T [Canadian General Electric Co. Ltd., Peterborough, ON (Canada)

    1997-12-31

    A reactor `power pulse` problem was identified for the Ontario Hydro Bruce generating stations. On a postulated inlet header break, the fuel strings in a large number of channels could relocate toward the upstream end, resulting in a power pulse. The solution adopted for Bruce GSA is to change the direction of fuelling, from against the flow, to fuelling with the flow. In this revised fuelling scheme, given a postulated inlet header failure, the fuel bundle with the highest burnup would relocate into the reactor core and introduce a negative reactivity during the accident. However, this fuelling configuration results in a highly irradiated fuel bundle residing in the most downstream position against the latch. The latch supports only the outer ring of elements, not the end plate. A resulting high stress on the end plate coupled with high levels of hydrogen and deuterium may result in Zr hydride assisted cracking in the end plate during hot shutdown conditions. (In fuelling against flow, this is not a problem, since the latch supported bundle is not irradiated and has only low levels of hydrogen and deuterium.) A fuel string supporting shield plug (f3sp) which supports the bundle end plate has been developed as a solution to the fuel bundle end plate cracking problem. It would replace the existing outlet shield plug in all channels. This paper will describe the f3sp design, associated fuel handling, operation and qualification for reactor use. (author). 8 figs.

  13. Fuel string supporting shield plug (f3sp) for Ontario Hydro - Bruce NGSA

    International Nuclear Information System (INIS)

    Henry, P.T.

    1996-01-01

    A reactor 'power pulse' problem was identified for the Ontario Hydro Bruce generating stations. On a postulated inlet header break, the fuel strings in a large number of channels could relocate toward the upstream end, resulting in a power pulse. The solution adopted for Bruce GSA is to change the direction of fuelling, from against the flow, to fuelling with the flow. In this revised fuelling scheme, given a postulated inlet header failure, the fuel bundle with the highest burnup would relocate into the reactor core and introduce a negative reactivity during the accident. However, this fuelling configuration results in a highly irradiated fuel bundle residing in the most downstream position against the latch. The latch supports only the outer ring of elements, not the end plate. A resulting high stress on the end plate coupled with high levels of hydrogen and deuterium may result in Zr hydride assisted cracking in the end plate during hot shutdown conditions. (In fuelling against flow, this is not a problem, since the latch supported bundle is not irradiated and has only low levels of hydrogen and deuterium.) A fuel string supporting shield plug (f3sp) which supports the bundle end plate has been developed as a solution to the fuel bundle end plate cracking problem. It would replace the existing outlet shield plug in all channels. This paper will describe the f3sp design, associated fuel handling, operation and qualification for reactor use. (author). 8 figs

  14. A Comparative Study of Cycle Variability of Laser Plug Ignition vs Classical Spark Plug Ignition in Combustion Engines

    Science.gov (United States)

    Done, Bogdan

    2017-10-01

    Over the past 30 years numerous studies and laboratory experiments have researched the use of laser energy to ignite gas and fuel-air mixtures. The actual implementation of this laser application has still to be fully achieved in a commercial automotive application. Laser Plug Ignition as a replacement for Spark Plug Ignition in the internal combustion engines of automotive vehicles, offers several potential benefits such as extending lean burn capability, reducing the cyclic variability between combustion cycles and decreasing the total amount of ignition costs, and implicitly weight and energy requirements. The paper presents preliminary results of cycle variability study carried on a SI Engine equipped with laser Plug Ignition system. Versus classic ignition system, the use of the laser Plug Ignition system assures the reduction of the combustion process variability, reflected in the lower values of the coefficient of variability evaluated for indicated mean effective pressure, maximum pressure, maximum pressure angle and maximum pressure rise rate. The laser plug ignition system was mounted on an experimental spark ignition engine and tested at the regime of 90% load and 2800 rev/min, at dosage of λ=1.1. Compared to conventional spark plug, laser ignition assures the efficiency at lean dosage.

  15. Isotopically exchangeable phosphorus as a correction value to adsorption isotherms

    International Nuclear Information System (INIS)

    Lopez, S.C.; Barbaro, N.O.; Rojas de Tramontini, S.L.; Martini, O.

    1984-01-01

    Adsorption isotherms in evaluation and characterization of soils are studied. The quantity of phosphorus present at first in soil, evaluated by radioisotopic techniques and used in correction of Langmuir and Freundlich isotherms, is discussed. (M.A.C.) [pt

  16. Plug pattern optimization for gamma knife radiosurgery treatment planning

    International Nuclear Information System (INIS)

    Zhang Pengpeng; Wu, Jackie; Dean, David; Xing Lei; Xue Jinyue; Maciunas, Robert; Sibata, Claudio

    2003-01-01

    Purpose: To develop a novel dose optimization algorithm for improving the sparing of critical structures during gamma knife radiosurgery by shaping the plug pattern of each individual shot. Method and Materials: We first use a geometric information (medial axis) aided guided evolutionary simulated annealing (GESA) optimization algorithm to determine the number of shots and isocenter location, size, and weight of each shot. Then we create a plug quality score system that checks the dose contribution to the volume of interest by each plug in the treatment plan. A positive score implies that the corresponding source could be open to improve tumor coverage, whereas a negative score means the source could be blocked for the purpose of sparing normal and critical structures. The plug pattern is then optimized via the GESA algorithm that is integrated with this score system. Weight and position of each shot are also tuned in this procedure. Results: An acoustic tumor case is used to evaluate our algorithm. Compared to the treatment plan generated without plug patterns, adding an optimized plug pattern into the treatment planning process boosts tumor coverage index from 95.1% to 97.2%, reduces RTOG conformity index from 1.279 to 1.167, lowers Paddick's index from 1.34 to 1.20, and trims the critical structure receiving more than 30% maximum dose from 16 mm 3 to 6 mm 3 . Conclusions: Automated GESA-based plug pattern optimization of gamma knife radiosurgery frees the treatment planning team from the manual forward planning procedure and provides an optimal treatment plan

  17. Sealing performance assessments of bentonite and bentonite/crushed rock plugs

    International Nuclear Information System (INIS)

    Ouyang, Shoung.

    1990-01-01

    Bentonite and mixtures of bentonite and crushed rock are potential sealing materials for high level nuclear waste repositories. The materials have been used to form cap layers to reduce infiltration for mined waste tailings and can also be used to construct clay liners for municipal as well as industrial waste managements. American Colloid C/S granular dentonite and Apache Leap tuff have been mixed to prepare samples for laboratory flow testing. Bentonite weight percent and crushed tuff gradation are the major variables studied. The sealing performance assessments include high injection pressure flow tests, polyaxial flow tests, high temperature flow tests, and piping tests. The results indicate that an appropriate composition would have at least 25% bentonite by weight mixed with well-graded crushed rock. Hydraulic properties of the mixture plugs may be highly anisotropic if significant particle segregation occurs during sample installation and compaction. Temperature has no negative effects on the sealing performance within the test range from room temperature to 60C. The piping damage to the sealing performance is small if the maximum hydraulic gradient does not exceed 120 and 280 for 25 and 35% bentonite content, respectively. The hydraulic gradients above which flow of bentonite may take place are deemed critical. Analytical work includes the introduction of bentonite occupancy percentage and water content at saturation as two major parameters for the plug design. A permeability model developed is useful for the prediction of permeability in clays. A piping model permits the estimation of critical hydraulic gradient allowed before the flow of bentonite takes place. It can also be used to define the maximum allowable pore diameter of a protective filter layer

  18. Isothermal calorimetry on enzymatic biodiesel production

    DEFF Research Database (Denmark)

    Fjerbæk, Lene

    2008-01-01

    information about effects taking place when using lipases immobilized on an inert carrier for transesterification of a triglyceride and an alcohol as for biodiesel production. The biodiesel is produced by rapeseed oil and methanol as well as ethanol and a commercial biocatalyst Novozym 435 from Novozymes...... containing a Candida Antarctica B lipase immobilized on an acrylic resin. The reaction investigated is characterized by immiscible liquids (oil, methanol, glycerol and biodiesel) and enzymes imm. on an inert carrier during reaction, which allows several effects to take place that during normal reaction...... conditions can not be elucidated. These effects have been observed with isothermal calorimetry bringing forth new information about the reaction of enzymes catalyzing transesterification. Enzymatic biodiesel production has until now not been investigated with isothermal microcalorimetry, but the results...

  19. Moisture sorption isotherms of dehydrated whey proteins

    OpenAIRE

    Suzana Rimac Brnčić; Vesna Lelas; Zoran Herceg; Marija Badanjak

    2010-01-01

    Moisture sorption isotherms describe the relation between the moisture content of the dry material (food) and relative humidity of the surrounding environment. The data obtained are important in modelling of drying process conditions, packaging and shelf-life stability of food that will provide maximum retaining of aroma, colour and texture as well as nutritive and biological value. The objective of this research was to establish the equilibrium moisture content and water activity, as well as...

  20. Fragmentation in rotating isothermal protostellar clouds

    International Nuclear Information System (INIS)

    Bodenheimer, P.; Black, D.C.

    1980-01-01

    In this paper we report briefly the results of an extensive set of 3-D hydrodynamic calculations that have been performed during the past two and one-half years to investigate the susceptibility of rotating clouds to gravitational fragmentation. Because of the immensity of parameter space and the expense of computations, we have chosen to restrict this investigation to strictly isothermal collapse sequences. (orig./WL)

  1. Local galactic kinematics: an isothermal model

    International Nuclear Information System (INIS)

    Nunez, J.

    1983-01-01

    The kinematical parameters of galactic rotation in the solar neighborhood and the corrections to the precession have been calculated. For this purpose, an isothermal model for the solar neighborhood has been used together with the high order momenta of the local stellar velocity distribution and the Ogorodnikov-Milne model. Both have been calculated using some samples of the ''512 Distant FK4/FK4 Sup. Stars'' of Fricke (1977) and of Gliese's Gatalogue. (author)

  2. The Stellar IMF from Isothermal MHD Turbulence

    Science.gov (United States)

    Haugbølle, Troels; Padoan, Paolo; Nordlund, Åke

    2018-02-01

    We address the turbulent fragmentation scenario for the origin of the stellar initial mass function (IMF), using a large set of numerical simulations of randomly driven supersonic MHD turbulence. The turbulent fragmentation model successfully predicts the main features of the observed stellar IMF assuming an isothermal equation of state without any stellar feedback. As a test of the model, we focus on the case of a magnetized isothermal gas, neglecting stellar feedback, while pursuing a large dynamic range in both space and timescales covering the full spectrum of stellar masses from brown dwarfs to massive stars. Our simulations represent a generic 4 pc region within a typical Galactic molecular cloud, with a mass of 3000 M ⊙ and an rms velocity 10 times the isothermal sound speed and 5 times the average Alfvén velocity, in agreement with observations. We achieve a maximum resolution of 50 au and a maximum duration of star formation of 4.0 Myr, forming up to a thousand sink particles whose mass distribution closely matches the observed stellar IMF. A large set of medium-size simulations is used to test the sink particle algorithm, while larger simulations are used to test the numerical convergence of the IMF and the dependence of the IMF turnover on physical parameters predicted by the turbulent fragmentation model. We find a clear trend toward numerical convergence and strong support for the model predictions, including the initial time evolution of the IMF. We conclude that the physics of isothermal MHD turbulence is sufficient to explain the origin of the IMF.

  3. Adsorption isotherms of pear at several temperatures

    Directory of Open Access Journals (Sweden)

    Mitrevski Vangelče

    2015-01-01

    Full Text Available The moisture adsorption isotherms of pear were determined at 15ºC, 30ºC and 45ºC using the standard static gravimetric method over a range of water activity from 0.112 to 0.920. The experimental data were fitted with isotherm equations recommended in ASAE Standard D245.5. In order to find which equation gives the best results, large number of numerical experiments were performed. After that, several statistical criteria proposed in scientific literature for estimation and selection of the best sorption isotherm equations were used. For each equation and experimental data set, the average performance index was calculated and models were ranked afterwards. After that, some statistical rejection criteria were checked (D’Agostino-Pearson test of normality, single-sample run test and significance and precision of the model parameters. The performed statistical analysis shows that the Guggenheim-Anderson-de Boer (GAB equation has the highest value of average performance index, but higher correlation between pair of parameters leads to lower precision of estimated parameters.[Projekat Ministarstva nauke Republike Srbije, br. TR 31058

  4. Report on electric cars and plug-in hybrid cars; Redegoerelse - elbiler og plug-in hybridbiler

    Energy Technology Data Exchange (ETDEWEB)

    Elkjaer Toennesen, A.; Winther, K.; Noerregaard, K. (Teknologisk Institut, Taastrup (Denmark)); Larsen, Esben; Christensen, Linda; Kveiborg, O. (Danmarks Teknologiske Univ., Kgs. Lyngby (DTU) (Denmark))

    2010-04-15

    The Center for Green Transport at the Danish Transport Authority has prepared this statement in order to uncover driving technical aspects, user expectations and needs, and the environmental consequences of using electric and plug-in hybrid cars. An electric car is defined as a car driven by an electric motor that has a battery that can be charged with power from the grid. A plug-in hybrid car is defined as a car that combines gasoline or diesel engine with an electric motor with a battery which can be recharged with power from the grid. From an overall consideration related to the transport sector electric cars and plug-in hybrid cars have the major advantage that negative impacts on environment and climate from traffic can be reduced while the high mobility is maintained. Through an increased use of electric cars and plug-in hybrid cars, the many advantages attached to the car as an individual transportation form is maintained, while CO{sub 2} emissions etc. are reduced. Electric cars and plug-in hybrid cars is one of the technologies that are considered to have particularly great prospects in the medium term when it comes to promoting new technologies in transport. Another advantage of using electric vehicles is the power supply factor. An increased use of electricity in transport will reduce the need for and dependence on fossil fuels in the sector. Both electric cars and plug-in hybrid cars are expected to be used for storage of wind power, a possibility which is hardly available today. The plug-in hybrid car could meet some of the challenges facing the pure electric car, because it also can use conventional fuel. The report presents analyses based on three focus areas: a) Users' needs, expectations and economics in relation to vehicles; b) The technology - and hence the manufacturers' opportunities and challenges; c) Connection to the power grid. (ln)

  5. The Plug-in Concept: Technology and Aesthetics of Change

    Directory of Open Access Journals (Sweden)

    Peter Šenk

    2013-01-01

    Full Text Available The architecture concept of plug-in is based on the duality of the infrastructure system and units or elements connected to it. In the context of megastructures, the concept was most vividly characterised by works of Archigram and Japanese Metabolists in the 1960s and early 1970s. Blurring the boundary between the building and the city, the plug-in concept outgrew architectural boundaries and was slowly transformed into an urbanistic concept.The paper presents the cultural context relevant to contemporaneity, which influenced specific development of the technology-driven concept of plug-in in the British Archigram Group and Japanese Metabolists. Based on the aesthetics of change and incompleteness, which was characterised by similar architectural manifestations despite entirely different cultural backgrounds, the plug-in concept foreshadowed social transformation based on freedom, individualisation and mobility in an utopian manner and held a promise of urban development with adaptability to unpredictable needs and desires of residents, who would become its co-creators with an active approach.Although the revolutionary sixties are quite some time behind, the plug-in concept in its commodified form has become and remained operational and relevant at least on the metaphorical level; in the contemporary space it is evident primarily in urbanism and not as much in its original architectural form.

  6. RCC Plug Repair Thermal Tools for Shuttle Mission Support

    Science.gov (United States)

    Rodriguez, Alvaro C.; Anderson, Brian P.

    2010-01-01

    A thermal math model for the Space Shuttle Reinforced Carbon-Carbon (RCC) Plug Repair was developed to increase the confidence in the repair entry performance and provide a real-time mission support tool. The thermal response of the plug cover plate, local RCC, and metallic attach hardware can be assessed with this model for any location on the wing leading edge. The geometry and spatial location of the thermal mesh also matches the structural mesh which allows for the direct mapping of temperature loads and computation of the thermoelastic stresses. The thermal model was correlated to a full scale plug repair radiant test. To utilize the thermal model for flight analyses, accurate predictions of protuberance heating were required. Wind tunnel testing was performed at CUBRC to characterize the heat flux in both the radial and angular directions. Due to the complexity of the implementation of the protuberance heating, an intermediate program was developed to output the heating per nodal location for all OML surfaces in SINDA format. Three Design Reference Cases (DRC) were evaluated with the correlated plug thermal math model to bound the environments which the plug repair would potentially be used.

  7. Manitoba plug-in hybrid electric vehicle (PHEV) demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Hoemsen, R. [Red River College, Winnipeg, MB (Canada); Parsons, R. [Government of Manitoba, Winnipeg, MB (Canada). Centre for Emerging Renewable Energy

    2010-07-01

    Manitoba has low electricity rates, the highest proportion of renewables, and a legislated commitment to reduce greenhouse gases. However, the province still relies heavily on oil as everyone else. The mix of energy opportunities in Manitoba were highlighted in this presentation, with particular reference to the commercialization of electric vehicles. Several photographs were presented of the Toyota plug-in hybrid vehicle and a plug-in hybrid electric demonstration vehicle. A demonstration project overview was offered that used technology from A123 Systems Inc. The conversion module and vehicle users were profiled. Topics that were presented related to the demonstration project included monitoring; gasoline fuel economy results; fuel economy variability; cold weather operation; cold weather issues; battery upgrade solutions; and highly qualified personnel. It was concluded that in terms of follow-up, there is a need to combine findings of current plug-in hybrid electric vehicle demonstration with those for the new Toyota production plug-in hybrid vehicles. Key next steps for the demonstration are to address cabin heating requirements; better characterizing winter performance; and implementation of IPLC units on all plug-in hybrid electric vehicles for electricity consumption. figs.

  8. Method for preventing plugging of water wells by clay

    Energy Technology Data Exchange (ETDEWEB)

    Blazhkov, V I

    1966-01-01

    A method is suggested for preventing the plugging of water-bearing sands by clay from drilling fluids. It consists in placing a cement plug in the upper nipple above the filter, in order to prevent its plugging during the installation. The drilling mud passes through the rinsing windows and fills the internal void of the filter column, thus preventing further percolation and plugging of the filter during its lowering. When a 2-filter column is lowered, the clay solution is pumped into the interval between the cement plug and the next filter; this is done gradually in proportion to the addition of new pipes. When the drilling mud level lowers in the annular space between the pipes, the mud cake, together with water-saturated sand, passes through the rinsing windows into the pipes and is removed to the surface by airlift or other methods. This procedure is described in detail, discussed for various conditions of well structure, and illustrated by schematic drawings. Its advantage is in the possibility of separate testing and production of all water-bearing zones in the well, and it does not require the use of pure water for well washing.

  9. Plug-in electric vehicles integrating fluctuating renewable electricity

    Energy Technology Data Exchange (ETDEWEB)

    Dallinger, David

    2013-11-01

    This paper examines a method to model plug-in electric vehicles as part of the power system and presents results for the contribution of plug-in electric vehicles to balance the fluctuating electricity generation of renewable energy sources. The scientific contribution includes: - A novel approach to characterizing fluctuating generation. This allows the detailed comparison of results from energy analysis and is the basis to describe the effect of electricity from renewable energy sources and plug-in electric vehicles on the power system. - The characterization of mobile storage, which includes the description of mobility behavior using probabilities and battery discharging costs. - The introduction of an agent-based simulation approach, coupling energy markets and distributed grids using a price-based mechanism design. - The description of an agent with specific driving behavior, battery discharging costs and optimization algorithm suitable for real plug-in vehicles and simulation models. - A case study for a 2030 scenario describing the contribution of plug-in electric vehicles to balance generation from renewable energy sources in California and Germany.

  10. Interaction of clay and concrete plugs - Plugging of 5 m deep hole KA1621G01 at Aespoe

    Energy Technology Data Exchange (ETDEWEB)

    Pusch, Roland [Drawrite AB, Lund (Sweden); Luleaa Technical Univ., Luleaa (Sweden); Ramqvist, Gunnar [Eltekno AB, Figeholm (Sweden)

    2011-11-15

    Sealing of deep boreholes in repository rock is planned to be made by installing dense smectite clay plugs where the rock is low-permeable and casting concrete where the holes intersect water-bearing fracture zones. Such zones have to be stabilized before sealing starts because fragments of rock can otherwise fall off and make it difficult to bring equipment for concrete casting and clay plug units down. These parts of the holes are filled with concrete and clay plugs are then inserted up to the nearest fracture zone where concrete is filled to the required level etc. The role of the concrete in the hole and in the closest part of the surrounding fracture zone is to provide stable parts that are sufficiently fine-porous to prevent clay particles from contacting clay plugs to migrate into the fractures and be lost by erosion. While the larger parts of long clay plugs are believed to stay largely intact chemically for hundreds of thousands of years, the parts adjacent to concrete plugs may undergo changes and so can the concrete plugs themselves. The objective of the presently reported project was to identify the detailed processes and quantify associated changes in physical properties by investigating samples of clay and concrete from a 2.5 m long plug of clay over which an equally long concrete plug had been cast and left to rest for 3 years. The outcome of the investigations was that significant chemically induced changes in mineralogy and physical performance had occurred within a few centimetres distance from the clay/concrete contact but that virtually no changes had taken place at larger distance. A comprehensive laboratory study including X-ray diffraction (XRD), X-ray fluorescence (XRF) and electron microscopy study (SEM and TEM) on the sample material was performed including also dual beam (combined ion and electron) microscopy. It was found that the clay had infiltrated the contacting concrete plug after filling of the borehole since clay was detected both

  11. Interaction of clay and concrete plugs - Plugging of 5 m deep hole KA1621G01 at Aespoe

    International Nuclear Information System (INIS)

    Pusch, Roland; Ramqvist, Gunnar

    2011-11-01

    Sealing of deep boreholes in repository rock is planned to be made by installing dense smectite clay plugs where the rock is low-permeable and casting concrete where the holes intersect water-bearing fracture zones. Such zones have to be stabilized before sealing starts because fragments of rock can otherwise fall off and make it difficult to bring equipment for concrete casting and clay plug units down. These parts of the holes are filled with concrete and clay plugs are then inserted up to the nearest fracture zone where concrete is filled to the required level etc. The role of the concrete in the hole and in the closest part of the surrounding fracture zone is to provide stable parts that are sufficiently fine-porous to prevent clay particles from contacting clay plugs to migrate into the fractures and be lost by erosion. While the larger parts of long clay plugs are believed to stay largely intact chemically for hundreds of thousands of years, the parts adjacent to concrete plugs may undergo changes and so can the concrete plugs themselves. The objective of the presently reported project was to identify the detailed processes and quantify associated changes in physical properties by investigating samples of clay and concrete from a 2.5 m long plug of clay over which an equally long concrete plug had been cast and left to rest for 3 years. The outcome of the investigations was that significant chemically induced changes in mineralogy and physical performance had occurred within a few centimetres distance from the clay/concrete contact but that virtually no changes had taken place at larger distance. A comprehensive laboratory study including X-ray diffraction (XRD), X-ray fluorescence (XRF) and electron microscopy study (SEM and TEM) on the sample material was performed including also dual beam (combined ion and electron) microscopy. It was found that the clay had infiltrated the contacting concrete plug after filling of the borehole since clay was detected both

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

    International Nuclear Information System (INIS)

    Oh, Chang H.; Kim, Eung S.

    2010-01-01

    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.

  13. Energy efficiency of multiport power converters used in plug-in/V2G fuel cell vehicles

    International Nuclear Information System (INIS)

    Bizon, Nicu

    2012-01-01

    Highlights: ► It is proposed a new FC hybrid power source topology for plug-in FC vehicle (PFCV). ► An energy efficiency analysis of three architectures for Multiport Power Converter (MPC) of HPS is performed. ► The MPC energy efficiency features were shown by analytical computing in all PFCV regimes. -- Abstract: In this paper is presented an analysis of energy efficiency for the Multiport Power Converters (MPCs) used in Plug-in Fuel Cell Vehicles (PFCVs). A generic MPC architecture for PFCVs is proposed, which is analyzed for different operating modes of MPC in relation with PFCV operating regimes and the plug-in feature. The basic MPC architecture is described in relation with the PFCV operating regimes. Two MPC architectures are derived from the basic MPC architecture: (1) the MPC1 architecture, which is the MPC architecture without reverse power flow during regenerative braking process, and (2) the MPC2 architecture – MPC architecture without charging mode of Energy Storage System (ESS) from the FC system. Taking in account the imposed window for the ESS state-of-charge, the MPC can be connected to Plug-in Charging Stations (PCS) to exchange power with the Electric Power (EP) system, which will include renewable Distributed Generation (DG) systems. The Energy Management Unit (EMU) of MPC can communicate with the EP system to determine the moments that match the energy demand of plug-in vehicle with the supply availability of the EP system, stabilizing the EP system. The MPC features regarding its energy efficiency were shown by analytical computing performed and appropriate simulations presented in relation with the ESS that can be charged (discharged) from (to) the home/DG/EP system.

  14. Device for sealing a rotating plug in a nuclear reactor

    International Nuclear Information System (INIS)

    Brandstetter, R.

    1975-01-01

    The invention relates to the sealing of a rotating plug in a nuclear reactor. The sealing arrangement comprises a friction track which is formed along the periphery of the top of a ring mounted on a stationary element. An annular base coaxial with the plug is secured in sealing-tight manner to the stationary bearing around the ring and the track by means of a seal which rests on the annular base and also on the friction track of the ring and which comprises at least one friction ring and a clamping spring ring. The seal is clamped against the friction track to retractable clamping means when the plug is stationary, the retractable clamping means being carried by a ring secured to the first-mentioned ring. (U.S.)

  15. Revascularization and Apical Plug in an Immature Molar

    Science.gov (United States)

    Roghanizadeh, Leyla; Fazlyab, Mahta

    2018-01-01

    Managing of necrotic permanent teeth with immature apices is a treatment challenges. Treatment of such teeth includes apexification, apical plug and more recently, revascularization technique with the probable advantage of continuation of root development. In the present case report the referred patient had discomfort with a necrotic immature mandibular first molar. Periapical radiography showed a rather large apical lesion around immature roots. Revascularization protocol using calcium-enriched mixture (CEM) cement was indicated for the mesial root. However, in distal canal apical plug technique was applied. At 2-year follow-up, both procedures were successful in relieving patient’s symptoms. Dentin formation and increase in length of the mesial root was obvious. Apical plug and revascularization technique proved to be successful in management of necrotic immature teeth; moreover, revascularization carried the advantage of continuation of root development. PMID:29692851

  16. Flexible Plug Repair for Shuttle Wing Leading Edge

    Science.gov (United States)

    Camarda, Charles J.; Sikora, Joseph; Smith, Russel; Rivers, H.; Scotti, Stephen J.; Fuller, Alan M.; Klacka, Robert; Reinders, Martin; Schwind, Francis; Sullivan, Brian; hide

    2012-01-01

    In response to the Columbia Accident Investigation Board report, a plug repair kit has been developed to enable astronauts to repair the space shuttle's wing leading edge (WLE) during orbit. The plug repair kit consists of several 17.78- cm-diameter carbon/silicon carbide (C/SiC) cover plates of various curvatures that can be attached to the refractory carbon-carbon WLE panels using a TZM refractory metal attach mechanism. The attach mechanism is inserted through the damage in the WLE panel and, as it is tightened, the cover plate flexes to conform to the curvature of the WLE panel within 0.050 mm. An astronaut installs the repair during an extravehicular activity (EVA). After installing the plug repair, edge gaps are checked and the perimeter of the repair is sealed using a proprietary material, developed to fill cracks and small holes in the WLE.

  17. Structural integrity investigations of feeder pipe ice plugging procedures

    International Nuclear Information System (INIS)

    Flaman, M.T.; Shah, N.N.

    1985-03-01

    A procedure involving the use of a liquid nitrogen cooled heat exchanger to form internal ice plugs in feeder pipes is routinely used in nuclear generating stations. The use of this procedure has caused concerns with regard to the safety of station maintenance personnel, and in regard to the integrity of the feeder pipes. This report describes the results of laboratory stress and pressure measurements which were performed on a feeder pipe section during ice plugging operations to investigate these concerns. From the results of this study, and from the results of previous studies of material behaviour at low temperatures, it has been determined that the ice plugging procedure can be performed on feeder pipes in a safe and effective manner

  18. Plug and Play PV Systems for American Homes

    Energy Technology Data Exchange (ETDEWEB)

    Hoepfner, Christian [Fraunhofer USA, Inc., Boston, MA (United States)

    2016-12-22

    The core objectives of the Plug & Play PV Systems Project were to develop a PV system that can be installed on a residential rooftop for less than $1.50/W in 2020, and in less than 10 hours (from point of purchase to commissioning). The Fraunhofer CSE team’s approach to this challenge involved a holistic approach to system design – hardware and software – that make Plug & Play PV systems: • Quick, easy, and safe to install • Easy to demonstrate as code compliant • Permitted, inspected, and interconnected via an electronic process Throughout the three years of work during this Department of Energy SunShot funded project, the team engaged in a substantive way with inspectional services departments and utilities, manufacturers, installers, and distributors. We received iterative feedback on the system design and on ideas for how such systems can be commercialized. This ultimately led us to conceiving of Plug & Play PV Systems as a framework, with a variety of components compatible with the Plug & Play PV approach, including string or microinverters, conventional modules or emerging lightweight modules. The framework enables a broad group of manufacturers to participate in taking Plug & Play PV Systems to market, and increases the market size for such systems. Key aspects of the development effort centered on the system hardware and associated engineering work, the development of a Plug & Play PV Server to enable the electronic permitting, inspection and interconnection process, understanding the details of code compliance and, on occasion, supporting applications for modifications to the code to allow lightweight modules, for example. We have published a number of papers on our testing and assessment of novel technologies (e.g., adhered lightweight modules) and on the electronic architecture.

  19. MFTF-α+T end plug magnet design

    International Nuclear Information System (INIS)

    Srivastava, V.C.; O'Toole, J.A.

    1983-01-01

    The conceptual design of the end-plug magnets for MFTF-α+T is described. MFTF-α+ T is a near-term upgrade of MFTF-B, which features new end plugs to improve performance. The Fusion Engineering Design Center has performed the engineering design of MFTF-α+T under the overall direction of Lawrence Livermore National Laboratory. Each end plug consists of two Yin-Yang pairs, each with approx.2.5:1 mirror ratio and approx.5-T peak field on axis; two transition coils; and a recircularizing solenoid. This paper describes the end-plug magnet system functional requirements and presents a conceptual design that meets them. The peak field at the windings of the end-plug coils is approx.6-T. These coils are designed using the NbTi MFTF-B conductor and cooled by a 4.2K liquid helium bath. All the end-plug magnets are designed to operate in the cryostable mode with adequate quench protection for safety. Shielding requirements are stated and a summary of heat loads is provided. Field and force calculations are discussed. The field on axis is shown to meet the functional requirements. Force resultants are reported in terms of winding running loads and resultant coil forces are also given. The magnet structural support is described. A trade study to determine the optimum end-cell coil internal nuclear shield thickness and the resulting coil size based on minimizing the end-cell life cycle cost is summarized

  20. Versatile Friction Stir Welding/Friction Plug Welding System

    Science.gov (United States)

    Carter, Robert

    2006-01-01

    A proposed system of tooling, machinery, and control equipment would be capable of performing any of several friction stir welding (FSW) and friction plug welding (FPW) operations. These operations would include the following: Basic FSW; FSW with automated manipulation of the length of the pin tool in real time [the so-called auto-adjustable pin-tool (APT) capability]; Self-reacting FSW (SRFSW); SR-FSW with APT capability and/or real-time adjustment of the distance between the front and back shoulders; and Friction plug welding (FPW) [more specifically, friction push plug welding] or friction pull plug welding (FPPW) to close out the keyhole of, or to repair, an FSW or SR-FSW weld. Prior FSW and FPW systems have been capable of performing one or two of these operations, but none has thus far been capable of performing all of them. The proposed system would include a common tool that would have APT capability for both basic FSW and SR-FSW. Such a tool was described in Tool for Two Types of Friction Stir Welding (MFS- 31647-1), NASA Tech Briefs, Vol. 30, No. 10 (October 2006), page 70. Going beyond what was reported in the cited previous article, the common tool could be used in conjunction with a plug welding head to perform FPW or FPPW. Alternatively, the plug welding head could be integrated, along with the common tool, into a FSW head that would be capable of all of the aforementioned FSW and FPW operations. Any FSW or FPW operation could be performed under any combination of position and/or force control.

  1. Plug the socket of the main closing valve in a nuclear power plant

    International Nuclear Information System (INIS)

    Neupauer, J.; Bednar, B.

    1988-01-01

    The plug is designed for closing the main closing valve socket during a refuelling shutdown of a nuclear power plant. The plug is fixed in the using jaws forced against the socket ring part. The socket is sealed by expanding a ring between two cone trays. A valve provided in the plug allows draining the pipe. The plug is inserted in the socket using a jib suspended on a rail. Following sealing both sockets the inner surfaces of the closing valve can be decontaminated. Following decontamination, a water-proof cover is slid over the plug protecting the plug moving mechanism from damage. (J.B.). 1 fig

  2. Isothermal CFD-model of Peirce-Smith converting process

    Energy Technology Data Exchange (ETDEWEB)

    Vaarno, J.; Pitkaelae, J.; Ahokainen, T.; Jokilaakso, A.

    1997-12-31

    The Peirce-Smith converter has been a dominating copper and nickel matte refining process since 1905. Due to extremely difficult process conditions, very little measured data has been available for studying interactions of the gas injection and molten sulphide matte. Detailed information on fluid dynamics of the gas injection is needed in solving gas injection related problems like refractory wear, accretion growth and tuyere blockage as well as optimising the efficiency of momentum and mass transfer created by the gas jets. A commercial CFD-code PHOENICS was used to solve isothermal flow field of gas and liquid in a Peirce-Smith converter. An Euler-Euler based algorithm was chosen for modelling fluid dynamics and evaluating controlling forces of a submerged gas injection generally. Predictions were made with a {kappa}-{epsilon} turbulence model in the body fitted co-ordinate system. The model has been verified with a 1/4 scale water model, and a parametric study with the mathematical model of submerged gas injection was made for the PS-process and the ladle injection processes. Limits of the modelling technique used were recognised, but calculated results indicates that the present model predicts the general flow field with reasonable accuracy and it can be used as input for more detailed mathematical models of gas plumes. Predicted bubble distribution, pattern of the flow field and magnitude of flow velocities were also used to evaluate scaling factors of physical models and general flow conditions of an industrial PS-converter. (orig.) 28 refs.

  3. Anomalous capillary flow of coal tar pitches

    Energy Technology Data Exchange (ETDEWEB)

    Saint Romain, J.L.; Lahaye, J.; Ehrburger, P.; Couderc, P.

    1986-06-01

    Capillary flow of liquid coal tar pitch into a coke bed was studied. Anomalies in the flow could not be attributed to a plugging effect for mesophase content lower than 20 wt%. The flow behaviour of small pitch droplets can be correlated with the change in physicochemical properties, as measured by the glass transition temperature, on penetration into the coke bed. 4 references.

  4. Warning: safety risk with some Apple AC Wall Plug Adapters

    CERN Multimedia

    CERN IT department

    2016-01-01

    Dear Mac and iOS Users, Apple has determined that some of its two prong Apple AC wall plug adapters may break and create a risk of electrical shock.   CERN users can now exchange their affected Apple wall plug adapters at the Service Desk. To find out if your adapter is affected and for any further information concerning the procedure to follow to exchange it, please check the following URL: https://cern.service-now.com/service-portal/view-outage.do?n=OTG0028639.

  5. The current status of theoretically based approaches to the prediction of the critical heat flux in flow boiling

    International Nuclear Information System (INIS)

    Weisman, J.

    1991-01-01

    This paper reports on the phenomena governing the critical heat flux in flow boiling. Inducts which vary with the flow pattern. Separate models are needed for dryout in annular flow, wall overheating in plug or slug flow and formation of a vapor blanket in dispersed flow. The major theories and their current status are described for the annular and dispersed regions. The need for development of the theoretical approach in the plug and slug flow region is indicated

  6. Sieve plugs in fenestrae of glomerular capillaries--site of the filtration barrier?

    DEFF Research Database (Denmark)

    Rostgaard, Jørgen; Qvortrup, Klaus

    2002-01-01

    The exact location of the filtration barrier of the glomerular capillary wall, which consists of an endothelium, a basement membrane and a visceral epithelium, has not yet been determined. Apparent discrepancies between different investigators in the past could be explained if postmortem...... and a filamentous surface coat about 60 nm thick covered the interfenestral domains of the endothelial cell. Based on these purely morphological data, we dare to suggest that the fenestral plugs are the primary site of the glomerular filtration barrier - albeit highly speculative, nevertheless a logical location...... - and consequently that the glomerular filtration process is a 'tangential-flow' as opposed to a 'dead-end' filtration process. A tangential-flow filtration would minimize 'clogging' and 'concentration polarization' in the 'filter'....

  7. Isothermal deformation of gamma titanium aluminide

    International Nuclear Information System (INIS)

    Srinivasan, R.; Singh, J.P.; Tuval, E.; Weiss, I.

    1996-01-01

    Gamma titanium aluminide has received considerable attention in recent years from the automotive industry as a potential material for making rotating and reciprocating components to produce a quieter and more efficient engine. The objectives of this study were to identify processing routes for the manufacture of automobile valves from gamma titanium aluminide. The issues considered were microstructure and composition of the material, and processing parameters such as deformation rates, temperatures, and total deformation. This paper examines isothermal deformation of gamma titanium aluminide in order to develop a processing window for this type of material

  8. Isothermal calorimetry of enzymatic biodiesel reaction

    DEFF Research Database (Denmark)

    Fjerbæk Søtoft, Lene; Westh, Peter; Christensen, Knud Villy

    2010-01-01

      Isothermal calorimetry ITC has been used to investigate enzymatic biodiesel production. The transesterification of rapeseed oil with methanol and ethanol was catalyzed by the immobilized lipase Novozym 435 at 40°C. The ITC-experiments clearly demonstrate the possibilities of investigating complex...... and composition change in the system, the heat of reaction at 40°C for the two systems has been determined to -9.8 ± 0.9 kJ/mole biodiesel formed from rapeseed oil and methanol, and - 9.3 ± 0.7 kJ/mole when rapeseed oil and ethanol is used....

  9. Integrated thermal control and system assessment in plug-chip spray cooling enclosure

    International Nuclear Information System (INIS)

    Zhang, Wei-Wei; Cheng, Wen-Long; Shao, Shi-Dong; Jiang, Li-Jia; Hong, Da-Liang

    2016-01-01

    Highlights: • A novel multi-heat source plug-chip spray cooling enclosure was designed. • Enhanced surfaces with different geometric were analyzed in integrated enclosure. • Overall thermal control with adjustable parameters in enclosure was studied. • Temperature disequilibrium of multi-heat source in enclosure was tested. • A comprehensive assessment system used to evaluate the practicality was proposed. - Abstract: Practical and integrated spray cooling system is urgently needed for the cooling of high-performance electronic chips due to the growth requirements of thermal management in workstation. The integration of multi heat sources and the management of integral system are particularly lacking. In order to fill the vacancies in the study of plug-chip spray cooling, an integrated cooling enclosure was designed in this paper. Multi heat sources were placed in sealed space and the heat was removed by spray. The printed circuit board plug-ins and radio frequency resistors were used as analog motherboards and chips, respectively. The enhanced surfaces with four different geometries and the plain surface were studied under the conditions of different inclination angles. The results were compared and the maximum critical heat flux (CHF) was obtained. Moreover, with the intention of the overall management of multi-heat source in integrated enclosure, the effect of the flow rate and the temperature disequilibrium, and the pulse heating in the process of transient cooling were also analyzed. In addition, a comprehensive assessment system, used to evaluate the practicality of spray cooling experimental devices, was proposed and the performance of enclosure was evaluated.

  10. Friction stir welding of F/M ODS steel plug and F/M steel tube

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Suk Hoon, E-mail: shkang77@kaeri.re.kr [Nuclear Materials Division, Korea Atomic Energy Research Institute (Korea, Republic of); Vasudevan, M. [Materials Technology Division, Indira Gandhi Centre for Atomic Research, Kalpakkam (India); Noh, Sanghoon; Jin, Hyun Ju; Jang, Jinsung; Kim, Tae Kyu [Nuclear Materials Division, Korea Atomic Energy Research Institute (Korea, Republic of)

    2016-11-01

    Highlights: • Friction stir welding (FSW) was used for joining of oxide dispersion strengthened (ODS) steel plug and F/M steel tube. • The curvature and smaller thickness of tube was the major limitation for applying FSW method, it was solved using specially designed jig. • Considerable hardening occurs in the joint because the cooling rate was sufficient to reproduce a martensitic microstructure. • The measured hoop strength of the FSWed joint was 70–90 MPa, the value was at around 70% of the tube. - Abstract: Friction stir welding (FSW) was used for joining of oxide dispersion strengthened (ODS) steel plug and F/M steel tube. The dimensions of the tube included outer diameter of 7 mm, wall thickness of 0.5 mm. The objective was to find suitable process variables for gaining enough frictional heat from those thin and curved pieces. A specially designed jig was used for stabilization and slow rotation of tube during FSW. Additionally, the plug was designed to overlap the tube. Inconel 718 was used as FSW tool, the diameter was 3.5 mm. The adequate rotation speed of the tool and jig were 1200 rpm and 1.5 rpm, respectively. The joining was successfully accomplished using above combination, showing a good possibility. The hoop stress tests of joint were conducted by blowing Ar gas into the tube, the flow rate of gas was 10 MPa/min. The measured hoop stress was 70–90 MPa, the value was at around 70% of the tube.

  11. Friction stir welding of F/M ODS steel plug and F/M steel tube

    International Nuclear Information System (INIS)

    Kang, Suk Hoon; Vasudevan, M.; Noh, Sanghoon; Jin, Hyun Ju; Jang, Jinsung; Kim, Tae Kyu

    2016-01-01

    Highlights: • Friction stir welding (FSW) was used for joining of oxide dispersion strengthened (ODS) steel plug and F/M steel tube. • The curvature and smaller thickness of tube was the major limitation for applying FSW method, it was solved using specially designed jig. • Considerable hardening occurs in the joint because the cooling rate was sufficient to reproduce a martensitic microstructure. • The measured hoop strength of the FSWed joint was 70–90 MPa, the value was at around 70% of the tube. - Abstract: Friction stir welding (FSW) was used for joining of oxide dispersion strengthened (ODS) steel plug and F/M steel tube. The dimensions of the tube included outer diameter of 7 mm, wall thickness of 0.5 mm. The objective was to find suitable process variables for gaining enough frictional heat from those thin and curved pieces. A specially designed jig was used for stabilization and slow rotation of tube during FSW. Additionally, the plug was designed to overlap the tube. Inconel 718 was used as FSW tool, the diameter was 3.5 mm. The adequate rotation speed of the tool and jig were 1200 rpm and 1.5 rpm, respectively. The joining was successfully accomplished using above combination, showing a good possibility. The hoop stress tests of joint were conducted by blowing Ar gas into the tube, the flow rate of gas was 10 MPa/min. The measured hoop stress was 70–90 MPa, the value was at around 70% of the tube.

  12. 环介导等温扩增联合横向流动试纸条可视化检测海豚链球菌方法的建立%Visual Detection of Streptococcus iniae Based on Loop- mediated Isothermal Amplification Combined with a Lateral Flow Dipstick

    Institute of Scientific and Technical Information of China (English)

    王瑞娜; 周前进; 陈炯

    2014-01-01

    海豚链球菌(Streptococcus iniae)是一种革兰氏阳性球菌,呈β溶血,可感染多种淡水和海洋鱼类。本研究利用环介导等温扩增技术(loop-mediated isothermal amplification, LAMP)进行核酸扩增,通过横向流动试纸条方法(lateral flow dipstick, LFD)实现检测,建立了一种可应用于海豚链球菌快速检测的LAMP-LFD技术。该技术以海豚链球菌促旋酶B亚单位(gyrase subunit B, gyrB)基因为检测靶标,设计3对引物进行由生物素标记的LAMP扩增反应,产物经异硫氰酸荧光素(fluorescein isothiocyanate, FITC)标记的探针杂交后,在LFD上完成检测。经优化的核酸扩增最适条件为65℃反应30 min,在此条件下,阳性扩增起始时间与模板浓度之间呈典型的线性相关性。从核酸扩增反应开始到LFD显色,整个检测时程只需40 min左右,比常规PCR技术缩短约2 h。LAMP-LFD能特异性地检出海豚链球菌,针对病原纯培养物的检测灵敏度为8.70×101 cfu/mL,是LAMP检测的10倍、常规PCR检测的100倍。以灵敏度浓度(8.70×101 cfu/mL)的海豚链球菌基因组DNA为模板进行的LAMP-LFD结果显示该方法具有良好的重复性。针对人工污染花鲈(Lateolabrax japonicus)肝组织的检测灵敏度为4.35×103 cfu/mL,同样为常规PCR检测方法的100倍。利用本方法可成功从患病花鲈的组织样品中检测出海豚链球菌,检测结果与常规的细菌分离鉴定方法结果一致。因此,利用LAMP-LFD能特异、准确、高效地检测出海豚链球菌,而且操作简单、费用低、耗时短,有望成为海豚链球菌的常规检测方法。%Streptococcus iniae is a species belonging to Gram-positive coccus and produces beta hemolysis, which can infect a broad range of freshwater and marine fish species and lead to seriously economic losses in the aquaculture industry worldwide. Thus, a diagnostic method for rapid and accurate detection of S. iniae was

  13. A new approach to non-isothermal models for nematic liquid crystals

    Czech Academy of Sciences Publication Activity Database

    Feireisl, Eduard; Frémond, M.; Rocca, E.; Schimperna, G.

    2012-01-01

    Roč. 205, č. 2 (2012), s. 651-672 ISSN 0003-9527 R&D Projects: GA ČR GA201/09/0917 Institutional research plan: CEZ:AV0Z10190503 Keywords : liquid crystals * non-isothermal model * flows Subject RIV: BA - General Mathematics Impact factor: 2.292, year: 2012 http://www.springerlink.com/content/cl205h73077jr810/

  14. An assessment of fuel freezing and drainage phenomena in a reactor shield plug following a core disruptive accident

    International Nuclear Information System (INIS)

    El-Genk, M.; Cronenberg, A.W.

    1978-01-01

    An important problem related to the assessment of the recriticality potential for an LMFBR following a core disruptive accident is an understanding of the freezing phenomena of molten fuel on a cold structure which may prevent fuel dispersal and sunsequent shutdown. Transient analytical freezing and drainage calculations have been applied to molten UO 2 travel through the rather cold lower shield plug of the Clinch River Breeder Reactor (CRBR). The successive approximation technique is used to obtain a solution of the non-linear freezing problem, where such effects as heat generation, viscous heat dissipation, temperature dependent thermophysical properties and a convective boundary condition at the solidification front have been incorporated into the present analytical formulation. Results indicate that previous steady-state analysis overestimate the rate of frozen layer build-up by about a factor of two. However, of primary importance is the driving force for drainage and the diameter of the shield plug flow channel. (Auth.)

  15. Internal performance of a 10 deg conical plug nozzle with a multispoke primary and translating external shroud

    Science.gov (United States)

    Bresnahan, D. L.

    1972-01-01

    An experimental investigation was conducted in a nozzle static test facility to determine the performance characteristics of a cold-flow, 21.59-centimeter-diameter plug nozzle with a multispoke primary. Two multispoke primary nozzles, a 12-spoke and a 24-spoke, were tested and compared with an annular plug nozzle. The supersonic cruise configurations for both spoke primaries performed about the same, with a gross thrust coefficient of 0.974, a decrease of approximately 1.5 percent from the reference nozzle. The takeoff configuration for the 12-spoke primary had a gross thrust coefficient of 0.957, a decrease of 1.5 percent from the reference nozzle, and the 24-spoke primary had a gross thrust coefficient of 0.95.

  16. Isothermal and non-isothermal conditions of isotope separation by chemical exchange method

    International Nuclear Information System (INIS)

    Khoroshilov, A.V.; Andreev, B.M.; Katalnikov, S.G.

    1992-01-01

    The published data about the effect of temperature on thermodynamic and mass transfer parameters of isotope separation by the chemical exchange method were used to examine the influence of iso- and non-isothermal conditions on the effectiveness of the separation process. It has been shown that simultaneous fulfillment of several optimization criteria is impossible in optimization of the isothermal process. If the limitation that temperature must be constant in the whole range of concentrational changes for an isolated isotope is removed, then it is possible to solve the problem of optimization with simultaneous fulfillment of several optimization criteria. When the separation process is carried out with non-isothermal conditions, that is, in temperature cascade, then the maximum concentration change takes place at every theoretical separation plate, and whole cascade is characterised by maximum throughput, minimum height and volume, and minimum cost for the stream reflux. From the results of our study, it was concluded that in the optimum temperature cascade, the cost of production of unity quantity of isotope can be decreased at least by a factor of two as compared with the optimal isothermal version of the separation process. (author)

  17. Plug-In Electric Vehicle Handbook for Consumers (Brochure)

    Energy Technology Data Exchange (ETDEWEB)

    2011-09-01

    Plug-in electric vehicles (PEVs) are entering the automobile market and are viable alternatives to conventional vehicles. This guide for consumers describes the basics of PEV technology, PEV benefits, how to select the right PEV, charging a PEV, and PEV maintenance.

  18. Alternative Fuels Data Center: Plug-In Hybrid Electric Vehicles

    Science.gov (United States)

    . Fueling and Driving Options Plug-in hybrid electric vehicle batteries can be charged by an outside sized hybrid electric vehicle. If the vehicle is driven a shorter distance than its all-electric range drives the wheels almost all of the time, but the vehicle can switch to work like a parallel hybrid at

  19. Height suppression of tomato plug seedlings by an environment ...

    African Journals Online (AJOL)

    Experiments were conducted to investigate appropriate concentrations of plant growth retardants (PGRs) and duration of seed soaking in order to suppress hypocotyl length and plug seedling height of 2 tomato cultivars ( Lycopersicum esculentum Mill. cv. Seogeon and Seokwang). Daminozide (B-9), uniconazole ...

  20. Project Gasbuggy well plugging and site restoration plan

    International Nuclear Information System (INIS)

    1978-07-01

    The operational plan for conducting the final restoration work at the site of the first U.S. underground nuclear experiment for the stimulation of low-productivity natural gas reservoirs is given. The plan includes well plugging procedures, surface facilities decontamination and removal procedures, radiological guidelines, and environmental considerations

  1. End plug welding of nuclear fuel elements-AFFF experience

    International Nuclear Information System (INIS)

    Bhatt, R.B.; Singh, S.; Aniruddha Kumar; Amit; Arun Kumar; Panakkal, J.P.; Kamath, H.S.

    2004-01-01

    Advanced Fuel Fabrication Facility is engaged in the fabrication of mixed oxide (U,Pu)O 2 fuel elements of various types of nuclear reactors. Fabrication of fuel elements involves pellet fabrication, stack making, stack loading and end plug welding. The requirement of helium bonding gas inside the fuel elements necessitates the top end plug welding to be carried out with helium as the shielding gas. The severity of the service conditions inside a nuclear reactor imposes strict quality control criteria, which demands for almost defect free welds. The top end plug welding being the last process step in fuel element fabrication, any rejection at this stage would lead to loss of effort prior to this step. Moreover, the job becomes all the more difficult with mixed oxide (MOX) as the entire fabrication work has to be carried out in glove box trains. In the case of weld rejection, accepted pellets are salvaged by cutting the clad tube. This is a difficult task and recovery of pellets is low (requiring scrap recovery operation) and also leads to active metallic waste generation. This paper discusses the experience gained at AFFF, in the past 12 years in the area of end plug welding for different types of MOX fuel elements

  2. Plug-In Electric Vehicle Handbook for Fleet Managers (Brochure)

    Energy Technology Data Exchange (ETDEWEB)

    2012-04-01

    Plug-in electric vehicles (PEVs) are entering the automobile market and are viable alternatives to conventional vehicles. This guide for fleet managers describes the basics of PEV technology, PEV benefits for fleets, how to select the right PEV, charging a PEV, and PEV maintenance.

  3. Axicell design for the end plugs of MFTF-B

    International Nuclear Information System (INIS)

    Thomassen, K.I.; Karpenko, V.N.

    1982-01-01

    Certain changes in the end-plug design in the Mirror Fusion Test Facility (MFTF-B) are described. The Laboratory (LLNL) proposes to implement these changes as soon as possible in order to construct the machine in an axicell configuration. The present physics and technology goals as well as the project cost and schedule will not be affected by these changes

  4. Nuclear determination of saturation profiles in core plugs

    International Nuclear Information System (INIS)

    Sletsgaard, J.; Oelgaard, P.L.

    1997-01-01

    A method to determine liquid saturations in core plugs during flooding is of importance when the relative permeability and capillary pressure function are to be determined. This part of the EFP-95 project uses transmission of γ-radiation to determine these saturations. In γ-transmission measurements, the electron density of the given substance is measured. This is an advantage as compared to methods that use electric conductivity, since neither oil nor gas conducts electricity. At the moment a single 137 Cs-source is used, but a theoretical investigation of whether it is possible to determine three saturations, using two radioactive sources with different γ-energies, has been performed. Measurements were made on three core plugs. To make sure that the measurements could be reproduced, all the plugs had a point of reference, i.e. a mark so that it was possible to place the plug same way every time. Two computer programs for calculation of saturation and porosity and the experimental setup are listed. (EG)

  5. Valley plugs, land use, and phytogeomorphic response: Chapter 14

    Science.gov (United States)

    Pierce, Aaron R.; King, Sammy L.; Shroder, John F.

    2013-01-01

    Anthropogenic alteration of fluvial systems can disrupt functional processes that provide valuable ecosystem services. Channelization alters fluvial parameters and the connectivity of river channels to their floodplains which is critical for productivity, nutrient cycling, flood control, and biodiversity. The effects of channelization can be exacerbated by local geology and land-use activities, resulting in dramatic geomorphic readjustments including the formation of valley plugs. Considerable variation in the response of abiotic processes, including surface hydrology, subsurface hydrology, and sedimentation dynamics, to channelization and the formation of valley plugs. Altered abiotic processes associated with these geomorphic features and readjustments influence biotic processes including species composition, abundance, and successional processes. Considerable interest exists for restoring altered fluvial systems and their floodplains because of their social and ecological importance. Understanding abiotic and biotic responses of channelization and valley-plug formation within the context of the watershed is essential to successful restoration. This chapter focuses on the primary causes of valley-plug formation, resulting fluvial-geomorphic responses, vegetation responses, and restoration and research needs for these systems.

  6. A Rotating Plug Model of Friction Stir Welding Heat Transfer

    Science.gov (United States)

    Raghulapadu J. K.; Peddieson, J.; Buchanan, G. R.; Nunes, A. C.

    2006-01-01

    A simplified rotating plug model is employed to study the heat transfer phenomena associated with the fiction stir welding process. An approximate analytical solution is obtained based on this idealized model and used both to demonstrate the qualitative influence of process parameters on predictions and to estimate temperatures produced in typical fiction stir welding situations.

  7. Choosing Wisely When It Comes to Eye Care: Punctal Plugs for Dry Eye

    Science.gov (United States)

    ... of Our 5-Part Series: Punctal Plugs for Dry Eye Making healthy lifestyle choices can help you protect ... discuss each item in detail. Punctal Plugs for Dry Eye Dry eye is a condition that millions of ...

  8. Instrumentation development for the Waste Isolation Pilot Plant (WIPP) borehole plugging program (BHP)

    International Nuclear Information System (INIS)

    Cook, C.W.

    1979-11-01

    This report discusses the instrumentation development needs of the borehole testing program as it now exists. Although requirements may change as the program progresses, the items indicated are basic to any borehole plugging program. Instrumentation is discussed both for the plug environment and for the plug itself. For the plug environment, a probe for measuring the disturbed region and a coordinate logging tool are required. For the plug itself, instrumentation includes measurements above, within, and below the plug. Instrumentation for most measurements above the plug is currently available; for measurements within and below the plug, however, further development is required. Specifically, resistivity, induction, and acoustic probes; an in situ stressmeter; and a hardwire, feedthrough system need to be developed

  9. Process and device for extracting a cylindrical element such a plug of a small diameter tube

    International Nuclear Information System (INIS)

    Ferlay, J.C.; Gente, D.; Jouin, D.

    1992-01-01

    The plug engaged in a steam generator tube is extracted by first machining away the expander and a part of its side wall then pulling the remainder of the plug from the tube with a tool engaging its closed end

  10. A numerical study of non-isothermal turbulent coaxial jets

    Energy Technology Data Exchange (ETDEWEB)

    Kriaa, Wassim; Abderrazak, Kamel; Mhiri, Hatem [Ecole Nationale d' Ingenieurs de Monastir, Laboratoire de Mecanique des Fluides et Thermique, Monastir (Tunisia); Palec, Georges le; Bournot, Philippe [Institut de Mecanique de Marseille, Marseille (France)

    2008-07-15

    In this work, we propose to study non isothermal air-air coaxial jets with two different approaches: parabolic and elliptic approaches. The standard k-{epsilon} model and the RSM model were applied in this study. The numerical resolution of the equations governing this flow type was carried out for: the parabolic approach, by a ''home-made'' CFD code based on a finite difference method, and the elliptic approach by an industrial code (FLUENT) based on a finite volume method. In forced convection mode (Fr={infinity}), the two turbulence models are valid for the prediction of the mean flow. But for turbulent sizes, k-{epsilon} model gives results closer to those achieved in experiments compared to RSM Model. Concerning the limit of validity of the parabolic and elliptic approaches, we showed that for velocities ratio r lower than 1, the results of the two approaches were satisfactory. On the other hand, for r>1, the difference between the results became increasingly significant. In mixed convection mode (Fr{approx_equal}20), the results obtained by the two turbulence models for the mean axial velocity were very different even in the plume region. For the temperature and the turbulent sizes the two models give satisfactory results which agree well with the correlations suggested by the experimenters for X{>=}20. Thus, the second order model with {sigma}{sub t}=0.85 is more effective for a coaxial jet study in a mixed convection mode. (orig.)

  11. Study on isothermal precision forging process of rare earth intensifying magnesium alloy

    International Nuclear Information System (INIS)

    Shan, Debin; Xu, Wenchen; Han, Xiuzhu; Huang, Xiaolei

    2012-01-01

    A three dimensional rigid-plastic finite element model is established to simulate the isothermal precision forging process of the magnesium alloy bracket based on DEFORM 3D in order to analyze the material flow rule and determine the forging process scheme. Some problems such as underfilling and too large forging pressure are predicted and resolved through optimizing the shapes of the billet successfully. Compared to the initial microstructure, the isothermal-forged microstructure of the alloy refines obviously and amounts of secondary phases precipitate on the matrix during isothermal forging process. In subsequent ageing process, large quantities of secondary phases precipitate from α-Mg matrix with increasing ageing time. The optimal comprehensive mechanical properties of the alloy have been obtained after aged at 473 K, 63 h with the ultimate tensile strength, tensile yield strength and elongation 380 MPa, 243 MPa and 4.07% respectively, which shows good potential for application of isothermal forging process of rare earth intensifying magnesium alloy.

  12. Fiscal Year 1993 Well Plugging and Abandonment Program Summary Report Y-12 Plant, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-09-01

    This report is a synopsis of the progress of the well plugging and abandonment program at the Y-12 Plant, Oak Ridge, Tennessee, from October 1993 through August 1994. A total of 57 wells and borings were plugged and abandoned during the period of time covered in this report. All wells and borings were plugged and abandoned in accordance with the Monitoring Well Plugging and Abandonment Plan for the U.S. Department of Energy, Y-12 Plant, Oak Ridge, Tennessee.

  13. Fiscal year 1993 well plugging and abandonment program, Y-12 Plant, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    1993-09-01

    This report is a synopsis of the progress of the well plugging and abandonment program at the Y-12 Plant, Oak Ridge, Tennessee, from December 1992 through August 20, 1993. A total of 70 wells and borings were plugged and abandoned during the period of time covered in this report. All wells and borings were plugged and abandoned in accordance with the Monitoring Well Plugging and Abandonment Plan for the US Department of Energy, Y-12 Plant, Oak Ridge, Tennessee (HSW, Inc. 1991).

  14. Polysaccharides and bacterial plugging. Final report, 1992--1993

    Energy Technology Data Exchange (ETDEWEB)

    Fogler, H.S.

    1995-02-01

    In situ core plugging experiments and transport experiments, using the model bacteria Leuconostoc m., have been conducted. Results demonstrated that cellular polysaccharide production increases cell distribution in porous media and caused an overall decrease in media permeability. Further, a parallel core plugging experiment was conducted and showed the feasibility of this system to divert injection fluid from high permeability zones into low permeability zones within porous media as is needed for profile modification. To implement this type of application, however, controlled placement of cells and rates of polymer production are needed. Therefore, kinetic studies were performed. A kinetic model was subsequently developed for Leuconostoc m. bacteria. This model is based on data generated from batch growth experiments and allows for the prediction of saccharide utilization, cell generation, and dextran production. These predictions can be used to develop injection strategies for field implementation. Transport and in situ growth micromodel experiments have shown how dextran allow cells to remain as clusters after cell division which enhanced cell capture and retention in porous media. Additional Damkohler experiments have been performed to determine the effects of the nutrient injection rate and nutrient concentration on the rate of porous media plugging. As shown experimentally and as predicted by a model for in situ growth, an increase in nutrient concentration and/or its injection rate will result in a faster rate of porous media plugging. Through continuum model simulations, it has been shown that the initial cell profiles play a key role on the core plugging rate. Controlling the location of the inoculating cells is thus another key factor in using bacteria for profile modification.

  15. Isothermal martensite formation at sub-zero temperatures

    DEFF Research Database (Denmark)

    Stojko, Allan; Hansen, Mikkel Fougt; Slycke, Jan

    2010-01-01

    austenitized and quenched in oil and thereafter investigated with vibrating sample agnetometry, which allows a quantitative assessment of the fraction of retained austenite as a function of the subzero temperature and time. Isothermal martensite formation was observed on interrupting the continuous cooling (5...... with a continuation of the martensitic transformation. On prolonged isothermal holding a volume reduction was observed for AISI 52100, but not for AISI 1070. A mechanism is proposed that explains the occurrence of isothermal martensite formation....

  16. Investigation of Plugging of Narrow Sodium Channels by Sodium and Carbon Dioxide Interaction

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sun Hee; Wi, Myung-Hwan; Min, Jae Hong; Kim, Tae-joon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    The supercritical CO{sub 2} Brayton cycle system is known to be a promising power conversion system for improving the efficiency and preventing the sodium water reaction (SWR) of the current SFR concept using a Rankine steam cycle. PCHEs are known to have potential for reducing the volume occupied by the sodium-to-CO{sub 2} exchangers as well as the heat exchanger mass relative to traditional shell-and-tube heat exchangers. Here, we report a study on a plugging test by the interaction of sodium and CO{sub 2} to investigate design parameters of sodium channels in the realistic operating conditions. We investigated a plugging test by an interaction of sodium and CO{sub 2} with different cross sectional areas of the sodium channels. It was found that the flow rate of sodium decreased earlier and faster with a narrower cross sectional area compared to a wider one. Our experimental results are expected to be used for determining the sodium channel areas of PCHEs.

  17. Alternative Fuels Data Center: Signage for Plug-In Electric Vehicle

    Science.gov (United States)

    Send a link to Alternative Fuels Data Center: Signage for Plug-In Electric Vehicle Charging Stations to someone by E-mail Share Alternative Fuels Data Center: Signage for Plug-In Electric Vehicle Charging Stations on Facebook Tweet about Alternative Fuels Data Center: Signage for Plug-In Electric Vehicle

  18. Alternative Fuels Data Center: Hybrid and Plug-In Electric Vehicle

    Science.gov (United States)

    Conversions Hybrid and Plug-In Electric Vehicle Conversions to someone by E-mail Share Alternative Fuels Data Center: Hybrid and Plug-In Electric Vehicle Conversions on Facebook Tweet about Alternative Fuels Data Center: Hybrid and Plug-In Electric Vehicle Conversions on Twitter Bookmark Alternative

  19. Test Confessions : A Study of Testing Practices for Plug-in Systems

    NARCIS (Netherlands)

    Greiler, M.; Van Deursen, A.; Storey, M.A.

    2011-01-01

    Testing plug-in-based systems is challenging due to complex interactions among many different plug-ins, and variations in version and configuration. The objective of this paper is to increase our understanding of what testers and developers think and do when it comes to testing plug-inbased systems.

  20. Rotating plug size study for liquid-metal fast breeder reactors

    International Nuclear Information System (INIS)

    Nemeth, L.J.

    1980-01-01

    A study was performed to evaluate possible rotating plug arrangements. The three-, two-, and one-rotating plug schemes were developed using a set of established restrictions and component sizes. The three-rotating plug configuration is the recommended reference design

  1. 30 CFR 250.1711 - When will MMS order me to permanently plug a well?

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false When will MMS order me to permanently plug a well? 250.1711 Section 250.1711 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE... Activities Permanently Plugging Wells § 250.1711 When will MMS order me to permanently plug a well? MMS will...

  2. Modeling and Prediction of Soil Water Vapor Sorption Isotherms

    DEFF Research Database (Denmark)

    Arthur, Emmanuel; Tuller, Markus; Moldrup, Per

    2015-01-01

    Soil water vapor sorption isotherms describe the relationship between water activity (aw) and moisture content along adsorption and desorption paths. The isotherms are important for modeling numerous soil processes and are also used to estimate several soil (specific surface area, clay content.......93) for a wide range of soils; and (ii) develop and test regression models for estimating the isotherms from clay content. Preliminary results show reasonable fits of the majority of the investigated empirical and theoretical models to the measured data although some models were not capable to fit both sorption...... directions accurately. Evaluation of the developed prediction equations showed good estimation of the sorption/desorption isotherms for tested soils....

  3. Isothermal and non-isothermal cure of a tri-functional epoxy resin (TGAP): a stochastic TMDSC study

    OpenAIRE

    Hutchinson, John M.; Shiravand, Fatemeh; Calventus Solé, Yolanda; Fraga Rivas, Iria

    2012-01-01

    The isothermal cure of a highly reactive tri-functional epoxy resin, tri-glycidyl para-amino phenol (TGAP), with diamino diphenyl sulphone (DDS), at two different cure temperatures Tc has been studied by both conventional differential scanning calorimetry (DSC) and by a stochastic temperature modulated DSC technique, TOPEM. From a series of isothermal cure experiments for increasing cure times, the glass transition temperature Tg as a function of isothermal cure time is determined by co...

  4. Tunneling in cosmology and isothermal inflation

    International Nuclear Information System (INIS)

    Brout, R.; Spindel, P.

    1991-01-01

    The wave function for the universe, as proposed by Hartle and Hawking, experiences tunneling for small values of the radius of the universe. This induces thermal effects and so a hot big bang. We first give a detailed analysis of the observer accelerating in Minkowski space in terms of the tunneling of his wave function beyond his turning point. Applied to cosmology one finds a temperature at the big bang equal to the Gibbons-Hawking value. The residual thermal effects which result in an isothermal inflationary expansion give rise to a renormalized self-consistently determined Hubble constant (and hence Gibbons-Hawking temperature) through the trace anomaly. A thermodynamic interpretation is given. These results militate against phase transitions as a motor for inflation. (orig.)

  5. Moisture sorption isotherms of dehydrated whey proteins

    Directory of Open Access Journals (Sweden)

    Suzana Rimac Brnčić

    2010-03-01

    Full Text Available Moisture sorption isotherms describe the relation between the moisture content of the dry material (food and relative humidity of the surrounding environment. The data obtained are important in modelling of drying process conditions, packaging and shelf-life stability of food that will provide maximum retaining of aroma, colour and texture as well as nutritive and biological value. The objective of this research was to establish the equilibrium moisture content and water activity, as well as monolayer value of two commercial powdered whey protein isolates before and after tribomechanical micronisation and enzymatic hydrolysis, respectively. At the same time it was necessary to evaluate the best moisture sorption isotherm equation to fit the experimental data. The equilibrium moisture contents in investigated samples were determined using standard gravimetric method at 20 °C. The range of water activities was 0.11 to 0.75. The monolayer moisture content was estimated from sorption data using Brunauer-Emmett-Teller (BET and Guggenheim-Anderson-de Boer (GAB models. The results have shown that tribomechanically treated whey protein isolates as well as protein hydrolizates had lower monolayer moisture content values as well as higher corresponding water activity. Therefore, in spite of the fact that they have lower moisture content, they can be storage at higher relative humidity compared to untreated samples. BET model gave better fit to experimental sorption data for a water activity range from 0.11-0.54, while GAB model gave the closest fit for a water activity to 0.75.

  6. ANALYTICAL SOLUTIONS OF SINGULAR ISOTHERMAL QUADRUPOLE LENS

    International Nuclear Information System (INIS)

    Chu Zhe; Lin, W. P.; Yang Xiaofeng

    2013-01-01

    Using an analytical method, we study the singular isothermal quadrupole (SIQ) lens system, which is the simplest lens model that can produce four images. In this case, the radial mass distribution is in accord with the profile of the singular isothermal sphere lens, and the tangential distribution is given by adding a quadrupole on the monopole component. The basic properties of the SIQ lens have been studied in this Letter, including the deflection potential, deflection angle, magnification, critical curve, caustic, pseudo-caustic, and transition locus. Analytical solutions of the image positions and magnifications for the source on axes are derived. We find that naked cusps will appear when the relative intensity k of quadrupole to monopole is larger than 0.6. According to the magnification invariant theory of the SIQ lens, the sum of the signed magnifications of the four images should be equal to unity, as found by Dalal. However, if a source lies in the naked cusp, the summed magnification of the left three images is smaller than the invariant 1. With this simple lens system, we study the situations where a point source infinitely approaches a cusp or a fold. The sum of the magnifications of the cusp image triplet is usually not equal to 0, and it is usually positive for major cusps while negative for minor cusps. Similarly, the sum of magnifications of the fold image pair is usually not equal to 0 either. Nevertheless, the cusp and fold relations are still equal to 0 in that the sum values are divided by infinite absolute magnifications by definition.

  7. Discovery Monday - Behind the plug: communication networks

    CERN Multimedia

    2004-01-01

    Ever wondered what happens to your email when you click "send"? And when you make a phone call, how does your voice travel down the wire? Find out more about communication networks and their applications at the next Discovery Monday in Microcosm on 1 March. At CERN, networks are used for a multitude of reasons. Mobile phones, for example, are used in the laboratory's underground areas. Optical fibre cabling ensures that CERN's computers are connected to the rest of the world. But how do optical fibres work and what does the future have in store? CERN's experiments also need networks. Particle detectors are made of many layers, each relays complex information to a computer analysis centre which reconstitutes the passage of the particles resulting from collisions. Many billions of bytes are transmitted every second from a multitude of sources, to many computers.  No single computer can handle such a huge flow of information. The next Discovery Monday is your chance to find out how this works.  Participate i...

  8. Reynolds number and geometry effects in laminar axisymmetric isothermal counterflows

    KAUST Repository

    Scribano, Gianfranco

    2016-12-29

    The counterflow configuration is a canonical stagnation flow, featuring two opposed impinging round jets and a mixing layer across the stagnation plane. Although counterflows are used extensively in the study of reactive mixtures and other applications where mixing of two streams is required, quantitative data on the scaling properties of the flow field are lacking. The aim of this work is to characterize the velocity and mixing fields in isothermal counterflows over a wide range of conditions. The study features both experimental data from particle image velocimetry and results from detailed axisymmetric simulations. The scaling laws for the nondimensional velocity and mixture fraction are obtained as a function of an appropriate Reynolds number and the ratio of the separation distance of the nozzles to their diameter. In the range of flow configurations investigated, the nondimensional fields are found to depend primarily on the separation ratio and, to a lesser extent, the Reynolds number. The marked dependence of the velocity field with respect to the separation ratio is linked to a high pressure region at the stagnation point. On the other hand, Reynolds number effects highlight the role played by the wall boundary layer on the interior of the nozzles, which becomes less important as the separation ratio decreases. The normalized strain rate and scalar dissipation rate at the stagnation plane are found to attain limiting values only for high values of the Reynolds number. These asymptotic values depend markedly on the separation ratio and differ significantly from the values produced by analytical models. The scaling of the mixing field does not show a limiting behavior as the separation ratio decreases to the smallest practical value considered.

  9. Computation of tokamak equilibria with steady flow

    International Nuclear Information System (INIS)

    Kerner, W.; Tokuda, Shinji

    1987-08-01

    The equations for ideal MHD equilibria with stationary flow are reexamined and addressed as numerically applied to tokamak configurations with a free plasma boundary. Both the isothermal (purely toroidal flow) and the poloidal flow cases are treated. Experiment-relevant states with steady flow (so far only in the toroidal direction) are computed by the modified SELENE40 code. (author)

  10. Field-test programs of borehole plugs in southeastern New Mexico

    International Nuclear Information System (INIS)

    Christensen, C.L.; Peterson, E.W.

    1981-01-01

    This paper gives a general overview of the repository-sealing field test effort being conducted by Sandia National Laboratories in support of the Waste Isolation Pilot Plant in southeast New Mexico. Summary descriptions of supporting activities, such as performance assessment and plugging materials development, are included to create the connection between modeling and laboratory activities as they relate to field results. Results of tests on a portion of a 17-year-old plug (Plug 217) recovered from a mine horizon and the Bell Canyon Test, in which a cement plug was emplaced to isolate a naturally pressurized aquifer, are given. Conclusions from these field plugging tests are included

  11. TOURGHREACT: A Simulation Program for Non-isothermal Multiphase Reactive Geochemical Transport in Variably Saturated Geologic Media

    OpenAIRE

    Xu, Tianfu; Sonnenthal, Eric; Spycher, Nicolas; Pruess, Karsten

    2004-01-01

    TOUGHREACT is a numerical simulation program for chemically reactive non-isothermal flows of multiphase fluids in porous and fractured media. The program was written in Fortran 77 and developed by introducing reactive geochemistry into the multiphase fluid and heat flow simulator TOUGH2. A variety of subsurface thermo-physical-chemical processes are considered under a wide range of conditions of pressure, temperature, water saturation, ionic strength, and pH and Eh. Interactions between ...

  12. The impact of non-isothermal soil moisture transport on evaporation fluxes in a maize cropland

    Science.gov (United States)

    Shao, Wei; Coenders-Gerrits, Miriam; Judge, Jasmeet; Zeng, Yijian; Su, Ye

    2018-06-01

    The process of evaporation interacts with the soil, which has various comprehensive mechanisms. Multiphase flow models solve air, vapour, water, and heat transport equations to simulate non-isothermal soil moisture transport of both liquid water and vapor flow, but are only applied in non-vegetated soils. For (sparsely) vegetated soils often energy balance models are used, however these lack the detailed information on non-isothermal soil moisture transport. In this study we coupled a multiphase flow model with a two-layer energy balance model to study the impact of non-isothermal soil moisture transport on evaporation fluxes (i.e., interception, transpiration, and soil evaporation) for vegetated soils. The proposed model was implemented at an experimental agricultural site in Florida, US, covering an entire maize-growing season (67 days). As the crops grew, transpiration and interception became gradually dominated, while the fraction of soil evaporation dropped from 100% to less than 20%. The mechanisms of soil evaporation vary depending on the soil moisture content. After precipitation the soil moisture content increased, exfiltration of the liquid water flow could transport sufficient water to sustain evaporation from soil, and the soil vapor transport was not significant. However, after a sufficient dry-down period, the soil moisture content significantly reduced, and the soil vapour flow significantly contributed to the upward moisture transport in topmost soil. A sensitivity analysis found that the simulations of moisture content and temperature at the soil surface varied substantially when including the advective (i.e., advection and mechanical dispersion) vapour transport in simulation, including the mechanism of advective vapour transport decreased soil evaporation rate under wet condition, while vice versa under dry condition. The results showed that the formulation of advective soil vapor transport in a soil-vegetation-atmosphere transfer continuum can

  13. Modeling and Validation of Sodium Plugging for Heat Exchangers in Sodium-cooled Fast Reactor Systems

    Energy Technology Data Exchange (ETDEWEB)

    Ferroni, Paolo [Westinghouse Electric Company LLC, Cranberry Township, PA (United States). Global Technology Development; Tatli, Emre [Westinghouse Electric Company LLC, Cranberry Township, PA (United States); Czerniak, Luke [Westinghouse Electric Company LLC, Cranberry Township, PA (United States); Sienicki, James J. [Argonne National Lab. (ANL), Argonne, IL (United States); Chien, Hual-Te [Argonne National Lab. (ANL), Argonne, IL (United States); Yoichi, Momozaki [Argonne National Lab. (ANL), Argonne, IL (United States); Bakhtiari, Sasan [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-06-29

    section and provided with Na2O deposition prediction capabilities, was developed. This state-of-the-art computational tool incorporates a first-principles Na2O deposition model developed by ANL, and combines it with predictive capabilities for the spatial and temporal variation of temperature, velocity, dissolved oxygen concentration, and wall temperature under flowing sodium conditions. The CFD model was validated under no-deposition conditions using experimental data collected with the SPPL, demonstrating the model’s capability to predict the thermal-hydraulics of the SPPL test section within the measurement uncertainty characterizing the SPPL instrumentation. The model’s deposition prediction capability was not, however, validated as the SPPL could not be operated under plugging conditions during the project, resulting in the lack of deposition data with adequate pedigree for a CFD model validation. Two novel diagnostic techniques to detect and characterize Na2O deposits, i.e. Ultrasonic Time Domain Reflectometry (UTDR) and Potential Drop (PD) techniques, were developed to ultimately assist in the validation effort under plugging conditions, which can be performed once the SPPL becomes operational. This development effort consisted first in demonstrating, analytically and/or computationally, the capability of these techniques to diagnose Na2O deposits inside of small channels (particularly the deposit’s thickness), and subsequently in the fabrication and testing of prototypical UTDR and PD instrumentation. The testing, performed on mockups of the SPPL test section, demonstrated the capability of these techniques to detect and characterize material discontinuities like those induced by sodium oxide deposition on stainless steel channel walls. Because of the mentioned impossibility to run the SPPL in a plugging mode, the developed instrumentation could not be tested in-situ, i.e. at the SPPL while deposits are being

  14. Experimental research on reinforced lightweight plugging composites.

    Directory of Open Access Journals (Sweden)

    BEKBAEV Arstan Abaevich

    2017-08-01

    Full Text Available Practical aspects of the well construction show that the use of conventional cementing materials do not always provide the necessary level of quality of well casing when the requirements to resources conservation are enhanced. This is true for such complex geological conditions as the alternation of beds with different formation pressures, low fracturing pressure gradients, drilling with ERD tc. The main problems in well casing under these conditions are the losses of cement slurries, low cement top, low-quality formation isolation, and as the result of this – the emergence of cross-flows. The high quality of well casing will be provided only by means of safe contact between cement stone and limiting surfaces (casing and rock, therefore to use expansion materials for cementing is a well-recognized method. Thus, it is obvious that their application does not give positive results for intervals with a thick filter cake or intervals with cavities, i.e. where space for expansion is greater than the magnitude of the expansion. At the same time it is very challenging to create high-quality cement in formations with abnormally low formation pressure or low fracture gradient. The solution of this problem is the use of lightweight cements, which scarcely expand while hardening. This is due to the fact that lightweight cement slurries are generally obtained by increasing the content of grouting fluid in the solution, resulting in increase of the distance between the crystal hydrates – hardening products, that leads to decrease of crystallization pressure of expansion agents on the space frame of the cement stone]. Moreover, such works as secondary reservoir developing (perforation, well completion and fracturing operations create high dynamic load on the cement stone, which leads to its destruction. The stone can be completely destroyed, that often causes premature flooding of wells and incurring additional costs. In this regard, it is necessary to

  15. Financial Statement Audit Report of Isothermal Community College.

    Science.gov (United States)

    Campbell, Ralph

    This report presents the results of the Isothermal Community College financial statement audit for the fiscal year ending on June 30, 1998. Isothermal Community College is a component of the State of North Carolina, thus the authority to audit is granted by Article 5A of G.S. 147. The accounts and operations of the institution were subject to…

  16. Adsorption isotherms and kinetics for dibenzothiophene on activated

    Indian Academy of Sciences (India)

    Adsorption isotherms were obtained and desulphurization kinetics were carried out on solutions of dibenzothiophene (DBT) and thiophene in a model fuel. The efficiencies of DBT and thiophene removal were reported. The adsorption isotherms fitted the Langmuir and Freundlich models. The highest adsorption capacity for ...

  17. Interpretation of Quasi-Isothermal Thermogravimetric Weight Curves

    DEFF Research Database (Denmark)

    Sørensen, Ole Toft

    1979-01-01

    Quasi-isothermal analysis (QIA) is a very useful technique. Compared to conventional non-isothermal thermogravimetry, close-lying reactions can easily be separated by use of this method and kinetic data can be obtained for each intermediate reaction in a single run. This paper discusses the shape...

  18. New Theoretical Expressions for the Five Adsorption Type Isotherms ...

    African Journals Online (AJOL)

    New Theoretical Expressions for the Five Adsorption Type Isotherms Classified by Bet Basing on Statistical Physics Treatment. ... that we have proposed, basing on statistical physics treatment, are rather powerful to better understand and interpret the various five physical adsorption Type isotherms at a microscopic level.

  19. Wireless Plug and Play Control Systems: Hardware, Networks, and Protocols

    DEFF Research Database (Denmark)

    Meybodi, Soroush Afkhami

    2012-01-01

    This dissertation reports the result of efforts to identify and solve the problems that arise when a control system is to be designed for various industrial case studies of the Plug and Play Process Control (P3C) project that require autonomous addition/removal of sensors, actuators and subsystems...... in only one of the P3C case studies where all of the nodes of the wireless networked control system are placed underground and should be able to transmit data among themselves. It is not a trivial problem because the well known radio frequency electromagnetic waves face serious difficulties penetrating...... is recommended for wireless plug and play control systems. Formation and maintenance of clusters of nodes are directly linked to the top level application layer via a novel application-based routing metric. The proposed routing metric facilitates implementation of the networking topology in accordance...

  20. [Plug-technique for umbilical hernia repair in the adult].

    Science.gov (United States)

    Brancato, G; Privitera, A; Gandolfo, L; Donati, M; Caglià, P

    2002-02-01

    Umbilical hernia represents 6% of all abdominal wall hernias in the adult. Surgical repair should always be carried out due to possible occurrence of complications. Aim of this paper is to evaluate the efficacy of the plug-technique. From October 1995 to April 2000, the authors performed 21 operations for acquired umbilical hernia with a defect smaller than 4 cm. Local anesthesia was used and a light intravenous sedation added in particularly anxious patients. The repair was achieved by insertion of a polypropylene dart plug sutured to the margins of the hernial defect. All patients were up and about straightaway and were discharged within 24 hours of surgery. Postoperative pain was mild and required hospital analgesia in only 19% of cases and domiciliary analgesia in 24%. During a follow-up ranging from 6 to 60 months (mean 30), only one recurrence has been recorded. This tension-free technique allows immediate rehabilitation, with few complications and a low recurrence rate.

  1. A Plug and Produce Framework for Industrial Collaborative Robots

    DEFF Research Database (Denmark)

    Schou, Casper; Madsen, Ole

    2017-01-01

    Collaborative robots are today ever more interesting in response to the increasing need for agile manufacturing equipment. Contrary to traditional industrial robots, collaborative robots are intended for working in dynamic environments alongside the production staff. To cope with the dynamic...... environment and workflow, new configuration and control methods are needed compared to those of traditional industrial robots. The new methods should enable shop floor operators to reconfigure the robot. This article presents a plug and produce framework for industrial collaborative robots. The article...... focuses on the control framework enabling quick and easy exchange of hardware modules as an approach to achieving plug and produce. To solve this, an agent-based system is proposed building on top of the robot operating system. The framework enables robot operating system packages to be adapted...

  2. Plug and Process Loads Capacity and Power Requirements Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Sheppy, M.; Gentile-Polese, L.

    2014-09-01

    This report addresses gaps in actionable knowledge that would help reduce the plug load capacities designed into buildings. Prospective building occupants and real estate brokers lack accurate references for plug and process load (PPL) capacity requirements, so they often request 5-10 W/ft2 in their lease agreements. Limited initial data, however, suggest that actual PPL densities in leased buildings are substantially lower. Overestimating PPL capacity leads designers to oversize electrical infrastructure and cooling systems. Better guidance will enable improved sizing and design of these systems, decrease upfront capital costs, and allow systems to operate more energy efficiently. The main focus of this report is to provide industry with reliable, objective third-party guidance to address the information gap in typical PPL densities for commercial building tenants. This could drive changes in negotiations about PPL energy demands.

  3. Strength and stability of microbial plugs in porous media

    Energy Technology Data Exchange (ETDEWEB)

    Sarkar, A.K. [NIPER/BDM-Oklahoma, Inc., Bartlesville, OK (United States); Sharma, M.M.; Georgiou, G. [Univ. of Texas, Austin, TX (United States)

    1995-12-31

    Mobility reduction induced by the growth and metabolism of bacteria in high-permeability layers of heterogeneous reservoirs is an economically attractive technique to improve sweep efficiency. This paper describes an experimental study conducted in sandpacks using an injected bacterium to investigate the strength and stability of microbial plugs in porous media. Successful convective transport of bacteria is important for achieving sufficient initial bacteria distribution. The chemotactic and diffusive fluxes are probably not significant even under static conditions. Mobility reduction depends upon the initial cell concentrations and increase in cell mass. For single or multiple static or dynamic growth techniques, permeability reduction was approximately 70% of the original permeability. The stability of these microbial plugs to increases in pressure gradient and changes in cell physiology in a nutrient-depleted environment needs to be improved.

  4. Plug and Play Framework for Theories of Social Group Dynamics

    DEFF Research Database (Denmark)

    Rehm, Matthias; Endrass, Birgit; André, Elisabeth

    2006-01-01

    We present an extensible framework for behavior control of social agents in a multi-agent system that has the following features. It implements a basic repertoire of socio-psychological models of behavior and interpersonal interactions that can be plugged and unplugged at will depending on the sp......We present an extensible framework for behavior control of social agents in a multi-agent system that has the following features. It implements a basic repertoire of socio-psychological models of behavior and interpersonal interactions that can be plugged and unplugged at will depending...... on the specific context of the application. This enables us to test several theories in isolation or combination to increase the transparency of the system and to investigate how the inclusion of a certain theory influences the behavior of the agents. Unlike earlier approaches, our approach is not bound...

  5. Integration of plug-in hybrid electric vehicles (PHEV) with grid connected residential photovoltaic energy systems

    Science.gov (United States)

    Nagarajan, Adarsh; Shireen, Wajiha

    2013-06-01

    This paper proposes an approach for integrating Plug-In Hybrid Electric Vehicles (PHEV) to an existing residential photovoltaic system, to control and optimize the power consumption of residential load. Control involves determining the source from which residential load will be catered, where as optimization of power flow reduces the stress on the grid. The system built to achieve the goal is a combination of the existing residential photovoltaic system, PHEV, Power Conditioning Unit (PCU), and a controller. The PCU involves two DC-DC Boost Converters and an inverter. This paper emphasizes on developing the controller logic and its implementation in order to accommodate the flexibility and benefits of the proposed integrated system. The proposed controller logic has been simulated using MATLAB SIMULINK and further implemented using Digital Signal Processor (DSP) microcontroller, TMS320F28035, from Texas Instruments

  6. Controlling nonspecific protein adsorption in a plug-based microfluidic system by controlling interfacial chemistry using fluorous-phase surfactants.

    Science.gov (United States)

    Roach, L Spencer; Song, Helen; Ismagilov, Rustem F

    2005-02-01

    Control of surface chemistry and protein adsorption is important for using microfluidic devices for biochemical analysis and high-throughput screening assays. This paper describes the control of protein adsorption at the liquid-liquid interface in a plug-based microfluidic system. The microfluidic system uses multiphase flows of immiscible fluorous and aqueous fluids to form plugs, which are aqueous droplets that are completely surrounded by fluorocarbon oil and do not come into direct contact with the hydrophobic surface of the microchannel. Protein adsorption at the aqueous-fluorous interface was controlled by using surfactants that were soluble in fluorocarbon oil but insoluble in aqueous solutions. Three perfluorinated alkane surfactants capped with different functional groups were used: a carboxylic acid, an alcohol, and a triethylene glycol group that was synthesized from commercially available materials. Using complementary methods of analysis, adsorption was characterized for several proteins (bovine serum albumin (BSA) and fibrinogen), including enzymes (ribonuclease A (RNase A) and alkaline phosphatase). These complementary methods involved characterizing adsorption in microliter-sized droplets by drop tensiometry and in nanoliter plugs by fluorescence microscopy and kinetic measurements of enzyme catalysis. The oligoethylene glycol-capped surfactant prevented protein adsorption in all cases. Adsorption of proteins to the carboxylic acid-capped surfactant in nanoliter plugs could be described by using the Langmuir model and tensiometry results for microliter drops. The microfluidic system was fabricated using rapid prototyping in poly(dimethylsiloxane) (PDMS). Black PDMS microfluidic devices, fabricated by curing a suspension of charcoal in PDMS, were used to measure the changes in fluorescence intensity more sensitively. This system will be useful for microfluidic bioassays, enzymatic kinetics, and protein crystallization, because it does not require

  7. Enhancements to the Redmine Database Metrics Plug in

    Science.gov (United States)

    2017-08-01

    management web application has been adopted within the US Army Research Laboratory’s Computational and Information Sciences Directorate as a database...project management web application.∗ The Redmine plug-in† enabled the use of the numerous, powerful features of the web application. The many...distribution is unlimited. 2 • Selectable export of citations/references by type, writing style , and FY • Enhanced naming convention options for

  8. "Plug-and-play" edge-preserving regularization

    DEFF Research Database (Denmark)

    Chen, Donghui; Kilmer, Misha E.; Hansen, Per Christian

    2014-01-01

    In many inverse problems it is essential to use regularization methods that preserve edges in the reconstructions, and many reconstruction models have been developed for this task, such as the Total Variation (TV) approach. The associated algorithms are complex and require a good knowledge of large...... cosine transform.hence the term "plug-and-play" . We do not attempt to improve on TV reconstructions, but rather provide an easy-to-use approach to computing reconstructions with similar properties....

  9. Plug-In Electric Vehicle Handbook for Workplace Charging Hosts

    Energy Technology Data Exchange (ETDEWEB)

    None

    2013-08-01

    Plug-in electric vehicles (PEVs) have immense potential for increasing the country's energy, economic, and environmental security, and they will play a key role in the future of U.S. transportation. By providing PEV charging at the workplace, employers are perfectly positioned to contribute to and benefit from the electrification of transportation. This handbook answers basic questions about PEVs and charging equipment, helps employers assess whether to offer workplace charging for employees, and outlines important steps for implementation.

  10. A Rigorous Methodology for Analyzing and Designing Plug-Ins

    DEFF Research Database (Denmark)

    Fasie, Marieta V.; Haxthausen, Anne Elisabeth; Kiniry, Joseph

    2013-01-01

    . This paper addresses these problems by describing a rigorous methodology for analyzing and designing plug-ins. The methodology is grounded in the Extended Business Object Notation (EBON) and covers informal analysis and design of features, GUI, actions, and scenarios, formal architecture design, including...... behavioral semantics, and validation. The methodology is illustrated via a case study whose focus is an Eclipse environment for the RAISE formal method's tool suite....

  11. Mesh Plug Repair of Inguinal Hernia; Single Surgeon Experience

    Directory of Open Access Journals (Sweden)

    Ahmet Serdar Karaca

    2013-10-01

    Full Text Available Aim: Mesh repair of inguinal hernia repairs are shown to be an effective and reliable method. In this study, a single surgeon%u2019s experience with plug-mesh method performs inguinal hernia repair have been reported. Material and Method: 587 patients with plug-mesh repair of inguinal hernia, preoperative age, body / mass index, comorbid disease were recorded in terms of form. All of the patients during the preoperative and postoperative hernia classification of information, duration of operation, antibiotics, perioperative complications, and later, the early and late postoperative complications, infection, recurrence rates and return to normal daily activity, verbal pain scales in terms of time and postoperative pain were evaluated. Added to this form of long-term pain ones. The presence of wound infection was assessed by the presence of purulent discharge from the incision. Visual analog scale pain status of the patients was measured. Results: 587 patients underwent repair of primary inguinal hernia mesh plug. One of the patients, 439 (74% of them have adapted follow-ups. Patients%u2019 ages ranged from 18-86. Was calculated as the mean of 47±18:07. Follow-up period of the patients was found to be a minimum of 3 months, maximum 55 months. Found an average of 28.2±13.4 months. Mean duration of surgery was 35.07±4.00 min (min:22mn-max:52mn, respectively. When complication rates of patients with recurrence in 2 patients (0.5%, hematoma development (1.4% in 6 patients, the development of infection in 11 patients (2.5% and long-term groin pain in 4 patients (0.9% appeared. Discussion: In our experience, the plug-mesh repair of primary inguinal hernia repair safe, effective low recurrence and complication rates can be used.

  12. Glow plug ignitor tests in H2 mixtures

    International Nuclear Information System (INIS)

    Liparulo, N.J.; Olhoeft, J.E.; Paddleford, D.F.

    1981-01-01

    The AEP, TVA and DUKE Electric Power companies, in cooperation with Westinghouse Electric Corporation have defined a testing program to determine the effectiveness of a glow plug hydrogen ignition system. The ignitor's capability was demonstrated for both static and dynamic conditions. Tests were performed with both spray addition and fan induced turbulence. It ignited hydrogen for all tests performed. The results of tests did not differ significantly from similar tests data previously reported. This report presents a discussion of the test results

  13. National Plug-In Electric Vehicle Infrastructure Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Wood, Eric W. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Rames, Clement L. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Muratori, Matteo [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Srinivasa Raghavan, Seshadri [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Melaina, Marc W. [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-09-15

    This document describes a study conducted by the National Renewable Energy Laboratory quantifying the charging station infrastructure required to serve the growing U.S. fleet of plug-in electric vehicles (PEVs). PEV sales, which include plug-in hybrid electric vehicles (PHEVs) and battery electric vehicles (BEVs), have surged recently. Most PEV charging occurs at home, but widespread PEV adoption will require the development of a national network of non-residential charging stations. Installation of these stations strategically would maximize the economic viability of early stations while enabling efficient network growth as the PEV market matures. This document describes what effective co-evolution of the PEV fleet and charging infrastructure might look like under a range of scenarios. To develop the roadmap, NREL analyzed PEV charging requirements along interstate corridors and within urban and rural communities. The results suggest that a few hundred corridor fast-charging stations could enable long-distance BEV travel between U.S. cities. Compared to interstate corridors, urban and rural communities are expected to have significantly larger charging infrastructure requirements. About 8,000 fast-charging stations would be required to provide a minimum level of coverage nationwide. In an expanding PEV market, the total number of non-residential charging outlets or 'plugs' required to meet demand ranges from around 100,000 to more than 1.2 million. Understanding what drives this large range in capacity requirements is critical. For example, whether consumers prefer long-range or short-range PEVs has a larger effect on plug requirements than does the total number of PEVs on the road. The relative success of PHEVs versus BEVs also has a major impact, as does the number of PHEVs that charge away from home. This study shows how important it is to understand consumer preferences and driving behaviors when planning charging networks.

  14. National Plug-In Electric Vehicle Infrastructure Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Muratori, Matteo [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Rames, Clement L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Srinivasa Raghavan, Sesha [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Melaina, Marc W [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Wood, Eric W [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2018-02-07

    This presentation describes a study conducted by the National Renewable Energy Laboratory quantifying the charging station infrastructure required to serve the growing U.S. fleet of plug-in electric vehicles (PEVs). PEV sales, which include plug-in hybrid electric vehicles (PHEVs) and battery electric vehicles (BEVs), have surged recently. Most PEV charging occurs at home, but widespread PEV adoption will require the development of a national network of non-residential charging stations. Installation of these stations strategically would maximize the economic viability of early stations while enabling efficient network growth as the PEV market matures. This document describes what effective co-evolution of the PEV fleet and charging infrastructure might look like under a range of scenarios. To develop the roadmap, NREL analyzed PEV charging requirements along interstate corridors and within urban and rural communities. The results suggest that a few hundred corridor fast-charging stations could enable long-distance BEV travel between U.S. cities. Compared to interstate corridors, urban and rural communities are expected to have significantly larger charging infrastructure requirements. About 8,000 fast-charging stations would be required to provide a minimum level of coverage nationwide. In an expanding PEV market, the total number of non-residential charging outlets or 'plugs' required to meet demand ranges from around 100,000 to more than 1.2 million. Understanding what drives this large range in capacity requirements is critical. For example, whether consumers prefer long-range or short-range PEVs has a larger effect on plug requirements than does the total number of PEVs on the road. The relative success of PHEVs versus BEVs also has a major impact, as does the number of PHEVs that charge away from home. This study shows how important it is to understand consumer preferences and driving behaviors when planning charging networks.

  15. Can Randall's plug composed of calcium oxalate form via the free particle mechanism?

    Science.gov (United States)

    Grases, F; Söhnel, O

    2017-09-08

    The likelihood of a Randall's plug composed of calcium oxalate monohydrate (COM) forming by the free particle mechanism in a model of kidney with a structure recently described by Robertson was examined at the most favourable conditions for the considered mechanism. The Robertson model of the kidney is used in the following development. The classical theory of crystallization was used for calculations. Initial COM nuclei were assumed to form at the beginning of the ascending loop of Henle where the supersaturation with respect to COM has been shown to reach the threshold level for spontaneous nucleation. Nucleation proceeds by a heterogeneous mechanism. The formed particles are transported in the nephron by a laminar flow of liquid with a parabolic velocity profile. Particles travel with a velocity dependent on their position in the cross-section of the nephron assumed to be straight tubule with smooth walls and without any sharp bends and kinks. These particles move faster with time as they grow as a result of being surrounded by the supersaturated liquid. Individual COM particles (crystals) can reach maximum diameter of 5.2 × 10 -6  m, i.e. 5.2 μm, at the opening of the CD and would thus always be washed out of the CD into the calyx regardless of the orientation of the CD. Agglomeration of COM crystals forms a fractal object with an apparent density lower than the density of solid COM. The agglomerate that can block the beginning of the CD is composed of more crystals than are available even during crystaluria. Moreover the settling velocity of agglomerate blocking the opening of the CD is lower than the liquid flow and thus such agglomerate would be washed out even from upward-draining CD. The free particle mechanism may be responsible for the formation of a Randall's plug composed by COM only in specific infrequent cases such as an abnormal structure of kidney. Majority of incidences of Randall's plug development by COM are caused by mechanism different

  16. Burst Test Qualification Analysis of DWPF Canister-Plug Weld

    International Nuclear Information System (INIS)

    Gupta, N.K.; Gong, Chung.

    1995-02-01

    The DWPF canister closure system uses resistance welding for sealing the canister nozzle and plug to ensure leak tightness. The welding group at SRTC is using the burst test to qualify this seal weld in lieu of the shear test in ASME B ampersand PV Code, Section IX, paragraph QW-196. The burst test is considered simpler and more appropriate than the shear test for this application. Although the geometry, loading and boundary conditions are quite different in the two tests, structural analyses show similarity in the failure mode of the shear test in paragraph QW-196 and the burst test on the DWPF canister nozzle Non-linear structural analyses are performed using finite element techniques to study the failure mode of the two tests. Actual test geometry and realistic stress strain data for the 304L stainless steel and the weld material are used in the analyses. The finite element models are loaded until failure strains are reached. The failure modes in both tests are shear at the failure points. Based on these observations, it is concluded that the use of a burst test in lieu of the shear test for qualifying the canister-plug weld is acceptable. The burst test analysis for the canister-plug also yields the burst pressures which compare favorably with the actual pressure found during burst tests. Thus, the analysis also provides an estimate of the safety margins in the design of these vessels

  17. End plug for fuel rod and welding method therefor

    International Nuclear Information System (INIS)

    Yoneda, Hiroshi; Murakami, Kazuo; Oyama, Jun-ichi.

    1996-01-01

    An end plug of a fuel rod comprises a pressure-insertion portion having a diameter somewhat greater than the inner diameter of a fuel cladding tube and a welding portion having a diameter substantially the same as the outer diameter of the cladding tube. A V-shaped recess having an outer diameter smaller than the greatest outer diameter of the pressure-insertion portion is formed over the entire circumferential surface of the outer circumference of the connection portion of the pressure-insertion portion and the welding portion. The pressure-insertion portion of the end plug is inserted to the end of the cladding tube till the end of the cladding tube abuts against the inclined surface of the V-shaped recess. The abutting surfaces of the end plug and the cladding tube are subjected to resistance welding in this state. The inner portion bulged from the inclined surface of the V-shaped recess is filled in the recess in a molten state. Lowering of temperature of the cladding tube in the vicinity of the welded portion is decreased by γ heat during reactor operation. Accordingly, lowering of ductility of the cladding tube and degradation of material of the welded region due to segregation of hydrogen in the cladding tube can be suppressed. (I.N.)

  18. Geochemical factors in borehole-shaft plug longevity

    International Nuclear Information System (INIS)

    Roy, D.M.

    1981-01-01

    Geochemical investigations that address factors controlling the longevity of repository sealing materials in a geochemical environment are discussed. Studies are being made of cement-based materials as major candidates for seals for borehole plugging, and shaft and tunnel sealing in certain potential repository environments. Factors controlling the extent of attainment of equilibrium of the plug components with time and the rate of approach to a state of stable equilibrium of the plug component chemical subsystem within the total system are discussed. The effect of these factors on changes in physical, mechanical and thermal properties of a seal system, and the consequent effectiveness of the seal in preventing transport of radioactive waste species are the dominant features to be determined. Laboratory experiments on the effects of anticipated temperature, pressure, and environmental factors (including chemical composition and specific rock type) are described. Thermodynamic studies are used to determine the potentially stable reaction products under conditions similar to those anticipated for the repository boreholes, shafts, and tunnels during and after the operating stage. Multitemperature reaction series are studied, and reaction kinetics are investigated for the purpose of predicting the course of likely reactions. Detailed studies of permeability, diffusion, and interfacial properties and chemical and microphase characterization of the products of experiments are carried out. Characterization studies of old and ancient cements, mortars, and concretes and prototype man-made seal materials are performed to further assess the factors associated with longevity

  19. Selecting a Control Strategy for Plug and Process Loads

    Energy Technology Data Exchange (ETDEWEB)

    Lobato, C.; Sheppy, M.; Brackney, L.; Pless, S.; Torcellini, P.

    2012-09-01

    Plug and Process Loads (PPLs) are building loads that are not related to general lighting, heating, ventilation, cooling, and water heating, and typically do not provide comfort to the building occupants. PPLs in commercial buildings account for almost 5% of U.S. primary energy consumption. On an individual building level, they account for approximately 25% of the total electrical load in a minimally code-compliant commercial building, and can exceed 50% in an ultra-high efficiency building such as the National Renewable Energy Laboratory's (NREL) Research Support Facility (RSF) (Lobato et al. 2010). Minimizing these loads is a primary challenge in the design and operation of an energy-efficient building. A complex array of technologies that measure and manage PPLs has emerged in the marketplace. Some fall short of manufacturer performance claims, however. NREL has been actively engaged in developing an evaluation and selection process for PPLs control, and is using this process to evaluate a range of technologies for active PPLs management that will cap RSF plug loads. Using a control strategy to match plug load use to users' required job functions is a huge untapped potential for energy savings.

  20. Predictions of hydrate plug dissociation with electrical heating

    Energy Technology Data Exchange (ETDEWEB)

    Davies, S.R.; Ivanic, J.; Sloan, E.D.

    2005-07-01

    The rate of dissociation for cylindrical hydrate plugs by the application of radial electrical heating was investigated for structure I and structure II hydrates for pressures of 7 MPa (1000 psia) and 14 MPa (2000 psia). Heating rates of 2.3 kWm{sup -3}, 4.5 kWm-3 and 6.8 kWm{sup -3} were investigated for a plug 91.4 cm (36 inches) in length and 2.54 cm (1 inch) in diameter. A heat transfer model was developed in cylindrical coordinates based on Fourier's Law with a boundary condition of constant heat flux at the pipe wall. The equation set was solved numerically using a finite difference grid and the standard explicit scheme. The model was found to replicate well the experimental observations with no fitted parameters. A computer program was formulated to allow the practicing engineer to simulate the dissociation of industrial hydrates with minimal complexity. This program was incorporated into the latest version of our CSMPlug program which has been used by a number of energy companies to predict hydrate plug dissociation rates in the field. (Author)

  1. An Energy Saving Green Plug Device for Nonlinear Loads

    Science.gov (United States)

    Bloul, Albe; Sharaf, Adel; El-Hawary, Mohamed

    2018-03-01

    The paper presents a low cost a FACTS Based flexible fuzzy logic based modulated/switched tuned arm filter and Green Plug compensation (SFC-GP) scheme for single-phase nonlinear loads ensuring both voltage stabilization and efficient energy utilization. The new Green Plug-Switched filter compensator SFC modulated LC-Filter PWM Switched Capacitive Compensation Devices is controlled using a fuzzy logic regulator to enhance power quality, improve power factor at the source and reduce switching transients and inrush current conditions as well harmonic contents in source current. The FACTS based SFC-GP Device is a member of family of Green Plug/Filters/Compensation Schemes used for efficient energy utilization, power quality enhancement and voltage/inrush current/soft starting control using a dynamic error driven fuzzy logic controller (FLC). The device with fuzzy logic controller is validated using the Matlab / Simulink Software Environment for enhanced power quality (PQ), improved power factor and reduced inrush currents. This is achieved using modulated PWM Switching of the Filter-Capacitive compensation scheme to cope with dynamic type nonlinear and inrush cyclical loads..

  2. Optimal control of a repowered vehicle: Plug-in fuel cell against plug-in hybrid electric powertrain

    Energy Technology Data Exchange (ETDEWEB)

    Tribioli, L., E-mail: laura.tribioli@unicusano.it; Cozzolino, R. [Dept. of Industrial Engineering, University of Rome Niccolo’ Cusano (Italy); Barbieri, M. [Engineering Dept., University of Naples Parthenope, Centro Direzionale-Isola C4, 80143 Naples (Italy)

    2015-03-10

    This paper describes two different powertrain configurations for the repowering of a conventional vehicle, equipped with an internal combustion engine (ICE). A model of a mid-sized ICE-vehicle is realized and then modified to model both a parallel plug-in hybrid electric powertrain and a proton electrolyte membrane (PEM) fuel cell (FC) hybrid powertrain. The vehicle behavior under the application of an optimal control algorithm for the energy management is analyzed for the different scenarios and results are compared.

  3. Optimal control of a repowered vehicle: Plug-in fuel cell against plug-in hybrid electric powertrain

    International Nuclear Information System (INIS)

    Tribioli, L.; Cozzolino, R.; Barbieri, M.

    2015-01-01

    This paper describes two different powertrain configurations for the repowering of a conventional vehicle, equipped with an internal combustion engine (ICE). A model of a mid-sized ICE-vehicle is realized and then modified to model both a parallel plug-in hybrid electric powertrain and a proton electrolyte membrane (PEM) fuel cell (FC) hybrid powertrain. The vehicle behavior under the application of an optimal control algorithm for the energy management is analyzed for the different scenarios and results are compared

  4. Isothermal Time-Temperature-Precipitation Diagram for an Aluminum Alloy 6005A by In Situ DSC Experiments

    Directory of Open Access Journals (Sweden)

    Benjamin Milkereit

    2014-03-01

    Full Text Available Time-temperature-precipitation (TTP diagrams deliver important material data, such as temperature and time ranges critical for precipitation during the quenching step of the age hardening procedure. Although the quenching step is continuous, isothermal TTP diagrams are often applied. Together with a so-called Quench Factor Analysis, they can be used to describe very different cooling paths. Typically, these diagrams are constructed based on mechanical properties or microstructures after an interrupted quenching, i.e., ex situ analyses. In recent years, an in situ calorimetric method to record continuous cooling precipitation diagrams of aluminum alloys has been developed to the application level by our group. This method has now been transferred to isothermal experiments, in which the whole heat treatment cycle was performed in a differential scanning calorimeter. The Al-Mg-Si-wrought alloy 6005A was investigated. Solution annealing at 540 °C and overcritical quenching to several temperatures between 450 °C and 250 °C were followed by isothermal soaking. Based on the heat flow curves during isothermal soaking, TTP diagrams were determined. An appropriate evaluation method has been developed. It was found that three different precipitation reactions in characteristic temperature intervals exist. Some of the low temperature reactions are not accessible in continuous cooling experiments and require isothermal studies.

  5. Adsorption isotherm special study. Final report

    International Nuclear Information System (INIS)

    1993-05-01

    The study was designed to identify methods to determine adsorption applicable to Uranium Mill Tailings Remedial Action (UMTRA) Project sites, and to determine how changes in aquifer conditions affect metal adsorption, resulting retardation factors, and estimated contaminant migration rates. EPA and ASTM procedures were used to estimate sediment sorption of U, As, and Mo under varying groundwater geochemical conditions. Aquifer matrix materials from three distinct locations at the DOE UMTRA Project site in Rifle, CO, were used as the adsorbents under different pH conditions; these conditions stimulated geochemical environments under the tailings, near the tailings, and downgradient from the tailings. Grain size, total surface area, bulk and clay mineralogy, and petrography of the sediments were characterized. U and Mo yielded linear isotherms, while As had nonlinear ones. U and Mo were adsorbed strongly on sediments acidified to levels similar to tailings leachate. Changes in pH had much less effect on As adsorption. Mo was adsorbed very little at pH 7-7.3, U was weakly sorbed, and As was moderately sorbed. Velocities were estimated for metal transport at different pHs. Results show that the aquifer materials must be characterized to estimate metal transport velocities in aquifers and to develop groundwater restoration strategies for the UMTRA project

  6. Isothermal thermogravimetric data acquisition analysis system

    Science.gov (United States)

    Cooper, Kenneth, Jr.

    1991-01-01

    The description of an Isothermal Thermogravimetric Analysis (TGA) Data Acquisition System is presented. The system consists of software and hardware to perform a wide variety of TGA experiments. The software is written in ANSI C using Borland's Turbo C++. The hardware consists of a 486/25 MHz machine with a Capital Equipment Corp. IEEE488 interface card. The interface is to a Hewlett Packard 3497A data acquisition system using two analog input cards and a digital actuator card. The system provides for 16 TGA rigs with weight and temperature measurements from each rig. Data collection is conducted in three phases. Acquisition is done at a rapid rate during initial startup, at a slower rate during extended data collection periods, and finally at a fast rate during shutdown. Parameters controlling the rate and duration of each phase are user programmable. Furnace control (raising and lowering) is also programmable. Provision is made for automatic restart in the event of power failure or other abnormal terminations. Initial trial runs were conducted to show system stability.

  7. Isothermal recovery rates in shape memory polyurethanes

    International Nuclear Information System (INIS)

    Azra, Charly; Plummer, Christopher J G; Månson, Jan-Anders E

    2011-01-01

    This work compares the time dependence of isothermal shape recovery in thermoset and thermoplastic shape memory polyurethanes (SMPUs) with comparable glass transition temperatures. In each case, tensile tests have been used to quantify the influence of various thermo-mechanical programming parameters (deformation temperature, recovery temperature, and stress and storage times following the deformation step) on strain recovery under zero load (free recovery) and stress recovery under fixed strain (constrained recovery). It is shown that the duration of the recovery event may be tuned over several decades of time with an appropriate choice of programming parameters, but that there is a trade-off between the rate of shape recovery and the recoverable stress level. The results are discussed in terms of the thermal characteristics of the SMPUs in the corresponding temperature range as characterized by modulated differential scanning calorimetry and dynamic mechanical analysis, with the emphasis on the role of the effective width of the glass transition temperature and the stability of the network that gives rise to the shape memory effect. (fast track communication)

  8. New Integrated Multilevel Converter for Switched Reluctance Motor Drives in Plug-in Hybrid Electric Vehicles with Flexible Energy Conversion

    DEFF Research Database (Denmark)

    Gan, Chun; Wu, Jianhua; Hu, Yihua

    2017-01-01

    This paper presents an integrated multilevel converter of switched reluctance motors (SRMs) fed by a modular front-end circuit for plug-in hybrid electric vehicle (PHEV) applications. Several operating modes can be achieved by changing the on-off states of the switches in the front-end circuit......, the battery can be charged by the external AC source or generator when the vehicle is in standstill condition. The SRM-based PHEV can operate at different speeds by coordinating power flow from the generator and battery. Simulation in MATLAB/Simulink and experiments on a three-phase 12/8 SRM confirm...

  9. Nanopore density effect of polyacrylamide gel plug on electrokinetic ion enrichment in a micro-nanofluidic chip

    Science.gov (United States)

    Wang, Jun-yao; Xu, Zheng; Li, Yong-kui; Liu, Chong; Liu, Jun-shan; Chen, Li; Du, Li-qun; Wang, Li-ding

    2013-07-01

    In this paper, the nanopore density effect on ion enrichment is quantitatively described with the ratio between electrophoresis flux and electroosmotic flow flux based on the Poisson-Nernst-Planck equations. A polyacrylamide gel plug is integrated into a microchannel to form a micro-nanofluidic chip. With the chip, electrokinetic ion enrichment is relatively stable and enrichment ratio of fluorescein isothiocyanate can increase to 600-fold within 120 s at the electric voltage of 300 V. Both theoretical research and experiments show that enrichment ratio can be improved through increasing nanopore density. The result will be beneficial to the design of micro-nanofluidic chips.

  10. Experimental study on flow pattern transitions for inclined two-phase flow

    Energy Technology Data Exchange (ETDEWEB)

    Kwak, Nam Yee; Lee, Jae Young [Handong Univ., Pohang (Korea, Republic of); Kim, Man Woong [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2007-07-01

    In this paper, experimental data on flow pattern transition of inclination angles from 0-90 are presented. A test section is constructed 2 mm long and I.D 1inch using transparent material. The test section is supported by aluminum frame that can be placed with any arbitrary inclined angles. The air-water two-phase flow is observed at room temperature and atmospheric condition using both high speed camera and void impedance meter. The signal is sampled with sampling rate 1kHz and is analyzed under fully-developed condition. Based on experimental data, flow pattern maps are made for various inclination angles. As increasing the inclination angels from 0 to 90, the flow pattern transitions on the plane jg-jf are changed, such as stratified flow to plug flow or slug flow or plug flow to bubbly flow. The transition lines between pattern regimes are moved or sometimes disappeared due to its inclined angle.

  11. Effect of aspect ratio on natural convective heat transfer adjacent to a vertival isothermal cylinder immersed in pure water

    International Nuclear Information System (INIS)

    Riu, Kap Jong; Eum, Yong Kyoon; Park, Sung Soon

    1990-01-01

    A numerical analysis is performed about the effect of aspect ratio on heat transfer adjacent to a vertical-isothermal cylinder of 0 deg C in pure water. The numerical results for the effect of aspect ratio are presented for ambient water temperature from 1.0 deg C to 15.0 deg C. They include velocity profiles, temperature profiles and mean Nusselt number for the entire flow field. The mean Nusselt numbers of vertival-isothermal cylinder are compared with that of vertival-isothermal plate in increasing aspect ratio of cylinder. Furthermore, the mean Nusselt numbers of unsteady region in the range of 0.084< R<0.328 are obtained by curve-fitting. The natural convection caused by phase change was investigated by experiments when the vertical ice cylinder was immersed in the pure water of which the tempetature range is from 2.0 to 10.0 deg C. Each figure shows a time-exposure photograph of flow occuring at the respective ambient water temperature conditions. As the ambient water temperature is increased from 2.0 to 10.0 deg C, the regimes of upward steady state flows, steady state dual flows and downward steady state flows are observed. Also, the variations of shapes of melting ice cylinder are investigated.(Author)

  12. Experimental investigation of non-Newtonian/Newtonian liquid-liquid flow in microchannel

    Science.gov (United States)

    Roumpea, Eynagelia-Panagiota; Weheliye, Weheliye; Chinaud, Maxime; Angeli, Panagiota; Lyes Kahouadji Collaboration; Omar. K. Matar Collaboration

    2015-11-01

    Plug flow of an organic phase and an aqueous non-Newtonian solution was investigated experimentally in a quartz microchannel with I.D. 200 μm. The aqueous phase was a glycerol solution where 1000 and 2000 ppm of xanthan gum was added while the organic phase was silicon oil with 155 and 5 cSt viscosity. The two phases were brought together in a T-junction and their flowrates varied from 0.3 to 6 ml/hr. High speed imaging was used to study the characteristics of the plugs and the effect of the liquid properties on the flow patterns while a two-colour micro-PIV technique was used to investigate velocity profiles and circulation patterns within the plugs. The experimental results revealed that plug length was affected by both flowrate and viscosity. In all cases investigated, a film of the continuous phase always surrounded the plugs and its thickness was compared with existing literature models. Circulation patterns inside plugs were obtained by subtracting the plug velocity and found to be depended on the plug length and the amount of xanthan gum in the aqueous phase. Finally, the dimensionless circulation time was calculated and plotted as a function of the plug length. Department of Chemical Engineering South Kensington Campus Imperial College London SW7 2AZ.

  13. Phase field modeling of dendritic coarsening during isothermal

    Directory of Open Access Journals (Sweden)

    Zhang Yutuo

    2011-08-01

    Full Text Available Dendritic coarsening in Al-2mol%Si alloy during isothermal solidification at 880K was investigated by phase field modeling. Three coarsening mechanisms operate in the alloy: (a melting of small dendrite arms; (b coalescence of dendrites near the tips leading to the entrapment of liquid droplets; (c smoothing of dendrites. Dendrite melting is found to be dominant in the stage of dendritic growth, whereas coalescence of dendrites and smoothing of dendrites are dominant during isothermal holding. The simulated results provide a better understanding of dendrite coarsening during isothermal solidification.

  14. Total Correlation Function Integrals and Isothermal Compressibilities from Molecular Simulations

    DEFF Research Database (Denmark)

    Wedberg, Rasmus; Peters, Günther H.j.; Abildskov, Jens

    2008-01-01

    Generation of thermodynamic data, here compressed liquid density and isothermal compressibility data, using molecular dynamics simulations is investigated. Five normal alkane systems are simulated at three different state points. We compare two main approaches to isothermal compressibilities: (1...... in approximately the same amount of time. This suggests that computation of total correlation function integrals is a route to isothermal compressibility, as accurate and fast as well-established benchmark techniques. A crucial step is the integration of the radial distribution function. To obtain sensible results...

  15. Program determines two-phase flow

    International Nuclear Information System (INIS)

    Yamashiro, C.E.; Espiell, L.G.S.; Farina, I.H.

    1986-01-01

    When a mixture of a gas and a liquid flows along a horizontal pipe, it is possible to have up to seven different flow patterns. These flow patterns are: 1. Dispersed. When nearly all the liquid is entrained as spray by the gas; 2. Annular. The liquid forms a film around the inside wall of the pipe, and the gas flows at a high velocity as a central core; 3. Bubble. Bubbles of gas move along at about the same velocity as the liquid; 4. Stratified. The liquid flows along the bottom of the pipe and the gas flows above over a smooth gas-liquid interface; 5. Wave. Is similar to stratified except the interface is disturbed by waves moving in the direction of flow; 6. Slug. Waves are picked up periodically in the form of frothy slugs that move at a much greater velocity than the average liquid velocity; 7. Plug. Alternate plugs of liquid and gas move along the pipe

  16. Computer Graphic Design Using Auto-CAD and Plug Nozzle Research

    Science.gov (United States)

    Rogers, Rayna C.

    2004-01-01

    The purpose of creating computer generated images varies widely. They can be use for computational fluid dynamics (CFD), or as a blueprint for designing parts. The schematic that I will be working on the summer will be used to create nozzles that are a part of a larger system. At this phase in the project, the nozzles needed for the systems have been fabricated. One part of my mission is to create both three dimensional and two dimensional models on Auto-CAD 2002 of the nozzles. The research on plug nozzles will allow me to have a better understanding of how they assist in the thrust need for a missile to take off. NASA and the United States military are working together to develop a new design concept. On most missiles a convergent-divergent nozzle is used to create thrust. However, the two are looking into different concepts for the nozzle. The standard convergent-divergent nozzle forces a mixture of combustible fluids and air through a smaller area in comparison to where the combination was mixed. Once it passes through the smaller area known as A8 it comes out the end of the nozzle which is larger the first or area A9. This creates enough thrust for the mechanism whether it is an F-18 fighter jet or a missile. The A9 section of the convergent-divergent nozzle has a mechanism that controls how large A9 can be. This is needed because the pressure of the air coming out nozzle must be equal to that of the ambient pressure other wise there will be a loss of performance in the machine. The plug nozzle however does not need to have an A9 that can vary. When the air flow comes out it can automatically sense what the ambient pressure is and will adjust accordingly. The objective of this design is to create a plug nozzle that is not as complicated mechanically as it counterpart the convergent-divergent nozzle.

  17. 环介导等温扩增联合横向流动试纸条可视化检测哈维氏弧菌的研究%Visual Detection ofVibrio harveyi Based on Loop-mediated Isothermal Amplification Combined with a Lateral Flow Dipstick

    Institute of Scientific and Technical Information of China (English)

    程蝶; 柴方超; 蔡怡; 周前进; 陈炯

    2016-01-01

    Based on nucleotide enrichment by a loop-mediated isothermal amplification(LAMP)and chromatographic visualization by a lateral flow dipstick(LFD)assay,this work aims to develop a novel LAMP-LFD method for the rapid detection of Vibrio harveyi. Three pairs of primers were designed using the hemolysin gene(vhhA)of V. harveyi as detection target,and used in LAMP reaction,among which the forward inner primer vhhA-FIP was biotinylated. Similarly,a fluorescein isothiocyanate(FITC)-labeled probe vhhA-HP was designed to specifically hybridize with LAMP products. And then the hybridized LAMP products were visually detected by LFD. The optimized LAMP was performed at 63℃ for 40 min;and visual detection via LFD took 50 min. The results indicated that LAMP-LFD was able to specifically identify V. harveyi from other 9 pathogenic bacteria commonly existing in the aquatic animals,such as V. vulnificus. The detection limit of LAMP-LFD was 1.0×102 CFU/mL for V. harveyi pure cultures(equivalent to 2 CFU per reaction),and 5×102 CFU/mL for V. harveyi contaminated tissues of large yellow croaker(equivalent to 20 CFU per reaction),both of which were 100 times lower than that of the conventional PCR method using both outer primers vhhA-F3/vhhA-B3. Therefore,this rapid and accurate LAMP-LFD method is a promising alternative in the surveillance and point-of-care test of V. harveyiin sea farming.%以哈维氏弧菌(Vibrio harveyi)为材料,利用环介导等温扩增技术(LAMP)进行核酸扩增,借助横向流动试纸条(LFD)完成产物检测,旨在建立一种可用于哈维氏弧菌快速检测的LAMP-LFD新技术。以哈维氏弧菌的溶血素基因(vhhA)为检测靶标设计了3对特异性引物(其中,上游内引物vhhA-FIP由生物素标记),进行由生物素标记的LAMP反应;同时设计1条异硫氰酸荧光素(FITC)标记的探针,与获得的LAMP产物进行特异性杂交,杂交产物经LFD完成检测。经

  18. Parametric Study of an Air Charged Franchot Engine with Novel Hot and Cold Isothermalizers

    Directory of Open Access Journals (Sweden)

    Jafar M. Daoud

    2017-12-01

    Full Text Available The Stirling engine is an external combustion engine that uses heat exchangers to enhance the addition and removal of energy. This makes the engine power-dense but expensive, less efficient and complicated. In this contribution, the Stirling engine based on the Franchot engine has novel cylindrical fins working as isothermalizers to improve heat transfer without the complications of heat exchangers. Enhancing the power density by isothermalizing work spaces is compared to the bare cylinder optimized by varying the phase angle. The theoretical analysis shows that both the adiabatic and isothermal fins increase the power and efficiency, achieving the Curzon and Ahlborn efficiency at the maximum power point. In comparison to the phase angle method, the finned engine resulted in much lower gas mass flow rate, which leads to a reduction in the regenerator pumping and enthalpy losses. Thus, the Stirling engine has the potential to be simple, cheap, efficient and power-dense, and thus can be used effectively for different applications.

  19. Erosion on spark plug electrodes; Funkenerosion an Zuendkerzenelektroden

    Energy Technology Data Exchange (ETDEWEB)

    Rager, J.

    2006-07-01

    Durability of spark plugs is mainly determined by spark gap widening, caused by electrode wear. Knowledge about the erosion mechanisms of spark plug materials is of fundamental interest for the development of materials with a high resistance against electrode erosion. It is therefore crucial to identify those parameters which significantly influence the erosion behaviour of a material. In this work, a reliable and reproducible testing method is presented which produces and characterizes electrode wear under well-defined conditions and which is capable of altering parameters specifically. Endurance tests were carried out to study the dependence of the wear behaviour of pure nickel and platinum on the electrode temperature, gas, electrode gap, electrode diameter, atmospheric pressure, and partial pressure of oxygen. It was shown that erosion under nitrogen is negligible, irrespective of the material. This disproves all common mechanism discussed in the literature explaining material loss of spark plug electrodes. Based on this observation and the variation of the mentioned parameters a new erosion model was deduced. This relies on an oxidation of the electrode material and describes the erosion of nickel and platinum separately. For nickel, electrode wear is caused by the removal of an oxide layer by the spark. In the case of platinum, material loss occurs due to the plasma-assisted formation and subsequent evaporation of volatile oxides in the cathode spot. On the basis of this mechanism a new composite material was developed whose erosion resistance is superior to pure platinum. Oxidation resistant metal oxide particles were added to a platinum matrix, thus leading to a higher erosion resistance of the composite. However, this can be decreased by a side reaction, the separation of oxygen from the metal oxides, which effectively assists the oxidation of the matrix. This reaction can be suppressed by using highly stable oxides, characterized by a large negative Gibbs

  20. Numerical research of two-phase flow in fractured-porous media based on discrete fracture fetwork model

    Science.gov (United States)

    Pyatkov, A. A.; Kosyakov, V. P.; Rodionov, S. P.; Botalov, A. Y.

    2018-03-01

    In this work was the study of the processes of isothermal and non-isothermal flow of high viscosity oil in a fractured-porous reservoir. The numerical experiment was done using our own reservoir simulator with the possibility of modeling of fluid motion in conditions of non-isothermal processes and long fractures in the formation.

  1. Isothermal, kinetic and thermodynamic studies on basic dye sorption ...

    African Journals Online (AJOL)

    Isothermal, kinetic and thermodynamic studies on basic dye sorption onto tartaric acid esterified wheat straw. ... African Journal of Biotechnology ... esterified wheat straw (EWS), was originally prepared by solid phase thermochemistry method.

  2. Isothermal, kinetic and thermodynamic studies on basic dye sorption ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-12-15

    Dec 15, 2009 ... The isothermal data correlated with the Langmuir model better than the. Freundlich model. ... there were two intra-particle diffusion steps in the dye sorption processes. .... rated monolayer of sorbate molecule on the sorbent.

  3. Improved Isotherm Data for Adsorption of Methane on Activated Carbons

    KAUST Repository

    Loh, Wai Soong

    2010-08-12

    This article presents the adsorption isotherms of methane onto two different types of activated carbons, namely, Maxsorb III and ACF (A-20) at temperatures from (5 to 75) °C and pressures up to 2.5 MPa. The volumetric technique has been employed to measure the adsorption isotherms. The experimental results presented herein demonstrate the improved accuracy of the uptake values compared with previous measurement techniques for similar adsorbate-adsorbent combinations. The results are analyzed with various adsorption isotherm models. The heat of adsorption, which is concentration and temperature dependent, has been calculated from the measured isotherm data. Henry\\'s law coefficients for these adsorbent-methane pairs are also evaluated at various temperatures. © 2010 American Chemical Society.

  4. Universality of isothermal fluid spheres in Lovelock gravity

    Science.gov (United States)

    Dadhich, Naresh; Hansraj, Sudan; Maharaj, Sunil D.

    2016-02-01

    We show universality of isothermal fluid spheres in pure Lovelock gravity where the equation of motion has only one N th order term coming from the corresponding Lovelock polynomial action of degree N . Isothermality is characterized by the equation of state, p =α ρ and the property, ρ ˜1 /r2 N . Then the solution describing isothermal spheres, which exist only for the pure Lovelock equation, is of the same form for the general Lovelock degree N in all dimensions d ≥2 N +2 . We further prove that the necessary and sufficient condition for the isothermal sphere is that its metric is conformal to the massless global monopole or the solid angle deficit metric, and this feature is also universal.

  5. Component sizing optimization of plug-in hybrid electric vehicles

    International Nuclear Information System (INIS)

    Wu, Xiaolan; Cao, Binggang; Li, Xueyan; Xu, Jun; Ren, Xiaolong

    2011-01-01

    Plug-in hybrid electric vehicles (PHEVs) are considered as one of the most promising means to improve the near-term sustainability of the transportation and stationary energy sectors. This paper describes a methodology for the optimization of PHEVs component sizing using parallel chaos optimization algorithm (PCOA). In this approach, the objective function is defined so as to minimize the drivetrain cost. In addition, the driving performance requirements are considered as constraints. Finally, the optimization process is performed over three different all electric range (AER) and two types of batteries. The results from computer simulation show the effectiveness of the approach and the reduction in drivetrian cost while ensuring the vehicle performance.

  6. The viscoelastic properties of the cervical mucus plug

    DEFF Research Database (Denmark)

    Bastholm, Sara K.; Becher, Naja; Stubbe, Peter Reimer

    2014-01-01

    labor. MethodsViscoelastic properties of CMPs were investigated with a dynamic oscillatory rheometer using frequency and stress sweep experiments within the linear viscoelastic region. Main outcome measuresThe rheological variables obtained were as follows: elastic modulus (G), viscous modulus (G......ObjectiveTo characterize the viscoelastic properties of cervical mucus plugs (CMPs) shed during labor at term. DesignExperimental research. SettingDepartment of Obstetrics and Gynecology, Aarhus University Hospital, Denmark. Population/SampleSpontaneously shed CMPs from 18 healthy women in active...

  7. Plug-and-Play Control – Modifying Control Systems Online

    DEFF Research Database (Denmark)

    Bendtsen, Jan Dimon; Trangbæk, K; Stoustrup, Jakob

    2013-01-01

    Often, when new sensor or actuator hardware be- comes available for use in a control system, it is desirable to retain the existing control system and apply the new control capabilities in a gradual fashion rather than decommissioning the entire existing system and replacing it with an altogether...... new control system. However, this requires that the existing controller remains in action, and the new control law component is added to the existing system. This paper formally introduces the concept of Plug-and-Play control and proposes two different methods of introducing new control components...

  8. Plug and Play Firms in the TNCs' Virtual Value Chain

    Directory of Open Access Journals (Sweden)

    Teresa Pakulska

    2016-04-01

    Full Text Available Growing virtualisation of the value chain appears to be an expression of implementation of ICT solutions in international business represented by TNCs. This creates new opportunities for cooperation within the value chain and its composition. The growing importance in this area can be attributed to companies integrating the value chain, known as plug and play. Their integration into the value creation chain gives a new dimension to TNCs' strategic choices from the fragmentation of activity and its integration on an international scale point of view.

  9. Plug-In Hybrid Vehicle Analysis (Milestone Report)

    Energy Technology Data Exchange (ETDEWEB)

    Markel, T.; Brooker, A.; Gonder, J.; O' Keefe, M.; Simpson, A.; Thornton, M.

    2006-11-01

    NREL's plug-in hybrid electric vehicle (PHEV) analysis activities made great strides in FY06 to objectively assess PHEV technology, support the larger U.S. Department of Energy PHEV assessment effort, and share technical knowledge with the vehicle research community and vehicle manufacturers. This report provides research papers and presentations developed in FY06 to support these efforts. The report focuses on the areas of fuel economy reporting methods, cost and consumption benefit analysis, real-world performance expectations, and energy management strategies.

  10. Compact Fluorescent Plug-In Ballast-in-a-Socket

    Energy Technology Data Exchange (ETDEWEB)

    Rebecca Voelker

    2001-12-21

    The primary goal of this program was to develop a ballast system for plug-in CFLs (compact fluorescent lamps) that will directly replace standard metal shell, medium base incandescent lampholders (such as Levition No. 6098) for use with portable lamp fixtures, such as floor, table and desk lamps. A secondary goal was to identify a plug-in CFL that is optimized for use with this ballast. This Plug-in CFL Ballastin-a-Socket system will allow fixture manufacturers to easily manufacture CFL-based high-efficacy portable fixtures that provide residential and commercial consumers with attractive, cost-effective, and energy-efficient fixtures for use wherever portable incandescent fixtures are used today. The advantages of this proposed system over existing CFL solutions are that the fixtures can only be used with high-efficacy CFLs, and they will be more attractive and will have lower life-cycle costs than screw-in or adapter-based CFL retrofit solutions. These features should greatly increase the penetration of CFL's into the North American market. Our work has shown that using integrated circuits it is quite feasible to produce a lamp-fixture ballast of a size comparable to the current Edison-screw 3-way incandescent fixtures. As for price points for BIAS-based fixtures, end-users polled by the Lighting Research Institute at RPI indicated that they would pay as much as an additional $10 for a lamp containing such a ballast. The ballast has been optimized to run with a 26 W amalgam triple biax lamp in the base-down position, yet can accept non-amalgam versions of the lamp. With a few part alterations, the ballast can be produced to support 32 W lamps as well. The ballast uses GE's existing L-Comp[1] power topology in the circuit so that the integrated circuit design would be a design that could possibly be used by other CFL and EFL products with minor modifications. This gives added value by reducing cost and size of not only the BIAS, but also possibly other

  11. Experiment on thermal insulation and sodium deposition of shield plug

    International Nuclear Information System (INIS)

    Hashiguchi, K.; Honda, M.; Shiratori, H.; Ozaki, O.; Suzuki, M.

    1986-01-01

    A series of experiments on temperature distribution and thermal insulation characteristics was conducted using a reduced scale model of LMFBR shield plug. Observation and measurement of sodium deposition were also conducted on the model after the experiment. The effect of annulus natural convection was clarified for temperature and the thermal insulation characteristics from evaluating the result. Temperature distribution analysis was conducted successfully by combining the general purpose structural analysis program NASTRAN and vertical annulus natural convection analysis program VANAC. Moreover, significant effect was substantiated for the annulus convection barrier to increase the thermal insulation performance, narrow horizontal gap structure to prevent sodium deposition and thermal insulation plates. (author)

  12. Numerical simulation of draining and drying procedure for the ITER Generic Equatorial Port Plug cooling system

    International Nuclear Information System (INIS)

    Tanchuk, Victor; Grigoriev, Sergey; Lyublin, Boris; Maquet, Philippe; Senik, Konstantin; Pak, Sunil; Udintsev, Victor

    2016-01-01

    Highlights: • The cooling system of the ITER Generic Equatorial Port Plug (GEPP) is of a complicated combination of horizontal and vertical channels. • The calculation model for the entire GEPP cooling circuit comprising 12 sub-circuits and built up of 2421 finite-volume elements has been developed. • Transient analysis of this model simulating the draining procedure by the KORSAR/B1 code has been performed. • Water in amount of 263 g of initial 531 kg in the GEPP remains in the dead-ends of the DSM and DFW channels in 150 s of draining procedure. • Almost 3 h are required to boil off 263 g of water trapped in the dead-ends. - Abstract: For effective vacuum leak testing all cooling circuits serving the ITER vessel and in-vessel components shall be drained and dried so that after this procedure taking less than 100 h the purge gas passing through a component has water content less than 100 ppm. This process is four-stage, with the first stage using a short blast of compressed nitrogen to blow most of water in the coolant channels out of the circuit. This process is hindered by volumes which trap water due to gravity. To remove the trapped water, it is necessary, first, to heat up the structure by hot and compressed nitrogen, and then water is evaporated by depressurized nitrogen. The cooling system of the ITER Diagnostic Equatorial Port Plugs is of a complicated hydraulic configuration. The system branching might make difficult removal of water from the piping in the scheduled draining mode. The authors have proposed the KORSAR computation code to simulate draining of the GEPP cooling circuit. The numerical simulation performed has made it possible to describe the process dynamics during draining of the entire GEPP cooling circuit and to define the process time, amount and location of residual water and evolution of two-phase flow regime.

  13. Numerical simulation of draining and drying procedure for the ITER Generic Equatorial Port Plug cooling system

    Energy Technology Data Exchange (ETDEWEB)

    Tanchuk, Victor, E-mail: Victor.Tanchuk@sintez.niiefa.spb.su [JSC “D.V. Efremov Institute of Electrophysical Apparatus”, 196641 St. Petersburg (Russian Federation); Grigoriev, Sergey; Lyublin, Boris [JSC “D.V. Efremov Institute of Electrophysical Apparatus”, 196641 St. Petersburg (Russian Federation); Maquet, Philippe [ITER Organization, Route de Vinon sur Verdon, 13115 St Paul-lez-Durance (France); Senik, Konstantin [JSC “D.V. Efremov Institute of Electrophysical Apparatus”, 196641 St. Petersburg (Russian Federation); Pak, Sunil [National Fusion Research Institute, Daejeon (Korea, Republic of); Udintsev, Victor [ITER Organization, Route de Vinon sur Verdon, 13115 St Paul-lez-Durance (France)

    2016-11-01

    Highlights: • The cooling system of the ITER Generic Equatorial Port Plug (GEPP) is of a complicated combination of horizontal and vertical channels. • The calculation model for the entire GEPP cooling circuit comprising 12 sub-circuits and built up of 2421 finite-volume elements has been developed. • Transient analysis of this model simulating the draining procedure by the KORSAR/B1 code has been performed. • Water in amount of 263 g of initial 531 kg in the GEPP remains in the dead-ends of the DSM and DFW channels in 150 s of draining procedure. • Almost 3 h are required to boil off 263 g of water trapped in the dead-ends. - Abstract: For effective vacuum leak testing all cooling circuits serving the ITER vessel and in-vessel components shall be drained and dried so that after this procedure taking less than 100 h the purge gas passing through a component has water content less than 100 ppm. This process is four-stage, with the first stage using a short blast of compressed nitrogen to blow most of water in the coolant channels out of the circuit. This process is hindered by volumes which trap water due to gravity. To remove the trapped water, it is necessary, first, to heat up the structure by hot and compressed nitrogen, and then water is evaporated by depressurized nitrogen. The cooling system of the ITER Diagnostic Equatorial Port Plugs is of a complicated hydraulic configuration. The system branching might make difficult removal of water from the piping in the scheduled draining mode. The authors have proposed the KORSAR computation code to simulate draining of the GEPP cooling circuit. The numerical simulation performed has made it possible to describe the process dynamics during draining of the entire GEPP cooling circuit and to define the process time, amount and location of residual water and evolution of two-phase flow regime.

  14. Specification for high voltage cable plug and socket connections for medical X-ray equipment

    International Nuclear Information System (INIS)

    1980-01-01

    Under the direction of the Light Engineering Standards Committee, a British Standard Specification has been prepared for three-conductor and four-conductor high-voltage cable plug and socket connections for medical X-ray equipment. The standard deals with the essential dimensions to ensure mechanical interchangeability, the recommended dimensions, the wiring connections to contacts of plug and socket and the marking of contacts of plug and socket. (U.K.)

  15. Plugging wells for abandonment: a state-of-the-art study and recommended procedures

    International Nuclear Information System (INIS)

    Herndon, J.; Smith, D.K.

    1976-09-01

    The state-of-the-art of borehole plugging of abandoned oil wells and the tools and materials used are discussed. Special problems encountered are considered and several case studies are outlined. The special procedures which must be followed if the plugged borehole is to be considered as a repository for radioactive wastes are discussed and special recommendations are made. A state-by-state summary is given of the regulatory requirements for borehole plugging

  16. Isothermal martensite formation at sub-zero temperatures

    DEFF Research Database (Denmark)

    Stojko, Allan; Hansen, Mikkel Fougt; Slycke, Jan

    2012-01-01

    , quenched in oil, and thereafter investigated with vibrating sample magnetometry, which allows a quantitative assessment of the fraction of retained austenite as a function of the sub-zero temperature and time. Isothermal martensite formation was observed on interrupting the continuous cooling (5 K...... with a continuation of the martensitic transformation. On prolonged isothermal holding, a volume reduction was observed for AISI 52100, but not for AISI 1070. Copyright © 2011 by ASTM International....

  17. Annular flow diverter valve

    International Nuclear Information System (INIS)

    Rider, R.L.

    1980-01-01

    A valve is described for diverting flow from the center of two concentric tubes to the annulus between the tubes or, operating in the reverse direction, for mixing fluids from concentric tubes into a common tube and for controlling the volume ratio of said flow. It consists of a toroidal baffle disposed in sliding engagement with the interior of the inner tube downstream of a plurality of ports in the inner tube, a plurality of gates in sliding engagement with the interior of the inner tube attached to the baffle for movement therewith, a servomotor having a bullet-shaped plug on the downstream end thereof, and drive rods connecting the servomotor to the toroidal baffle. The sevomotor is adapted to move the baffle into mating engagement with the bullet-shaped plug and simultaneously move the gates away from the ports in the inner tube and to move the baffle away from the bullet-shaped plug and simultaneously move the gates to cover the ports in the inner tube

  18. Effects of chemical reaction on moving isothermal vertical plate with variable mass diffusion

    Directory of Open Access Journals (Sweden)

    Muthucumaraswamy R.

    2003-01-01

    Full Text Available An exact solution to the problem of flow past an impulsively started infinite vertical isothermal plate with variable mass diffusion is presented here, taking into account of the homogeneous chemical reaction of first-order. The dimensionless governing equations are solved by using the Laplace - transform technique. The velocity and skin-friction are studied for different parameters like chemical reaction parameter, Schmidt number and buoyancy ratio parameter. It is observed that the veloc­ity increases with decreasing chemical reaction parameter and increases with increasing buoyancy ratio parameter.

  19. The Application of Simulation Method in Isothermal Elastic Natural Gas Pipeline

    Science.gov (United States)

    Xing, Chunlei; Guan, Shiming; Zhao, Yue; Cao, Jinggang; Chu, Yanji

    2018-02-01

    This Elastic pipeline mathematic model is of crucial importance in natural gas pipeline simulation because of its compliance with the practical industrial cases. The numerical model of elastic pipeline will bring non-linear complexity to the discretized equations. Hence the Newton-Raphson method cannot achieve fast convergence in this kind of problems. Therefore A new Newton Based method with Powell-Wolfe Condition to simulate the Isothermal elastic pipeline flow is presented. The results obtained by the new method aregiven based on the defined boundary conditions. It is shown that the method converges in all cases and reduces significant computational cost.

  20. Nonlinear Ion-Acoustic Waves in a Plasma Consisting of Warm Ions and Isothermal Distributed Electrons

    International Nuclear Information System (INIS)

    Abourabia, A.M.; Hassan, K.M.; Shahein, R.A.

    2008-01-01

    The formation of (1+1) dimensional ion-acoustic waves (IAWs) in an unmagnetized collisionless plasma consisting of warm ions and isothermal distributed electrons is investigated. The electrodynamics system of equations are solved analytically in terms of a new variable ξκ χ -φ τ, where k=k(ω) is a complex function, at a fixed position. The analytical calculations gives that the critical value σ = τ/τ ∼ 0.25 distinguishes between the linear and nonlinear characters of IAW within the nanosecond time scale. The flow velocity, pressure, number density, electric potential, electric field, mobility and the total energy in the system are estimated and illustrated

  1. Isothermal coarse mixing: experimental and CFD modelling

    International Nuclear Information System (INIS)

    Gilbertson, M.A.; Kenning, D.B.R.; Hall, R.W.

    1992-01-01

    A plane, two-dimensional flow apparatus has been built which uses a jet of solid 6mm diameter balls to model a jet of molten drops falling into a tank of water to study premixing prior to a vapour explosion. Preliminary experiments with unheated stainless steel balls are here compared with computational fluid dynamics (CFD) calculations by the code CHYMES. (6 figures) (Author)

  2. Fiscal year 1996 well plugging and abandonment program Y-12 Plant, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-04-01

    This report is a synopsis of the progress of the well plugging and abandonment program at the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee, from August 1995 through August 1996. A total of 27 wells, piezometers, and borings were plugged and abandoned during the period of time covered in this report. All wells and borings were plugged and abandoned in accordance with the Monitoring Well Plugging and Abandonment Plan for the U.S. Department of Energy, Y-12 Plant, Oak Ridge, Tennessee (HSW, Inc. 1991).

  3. Hydrological responses to channelization and the formation of valley plugs and shoals

    Science.gov (United States)

    Pierce, Aaron R.; King, Sammy L.

    2017-01-01

    Rehabilitation of floodplain systems focuses on restoring interactions between the fluvial system and floodplain, however, there is a paucity of information on the effects of valley plugs and shoals on floodplain hydrological processes. We investigated hydrologic regimes in floodplains at three valley plug sites, two shoal sites, and three unchannelized sites. Valley plug sites had altered surface and sub-surface hydrology relative to unchannelized sites, while only sub-surface hydrology was affected at shoal sites. Some of the changes were unexpected, such as reduced flood duration and flood depth in floodplains associated with valley plugs. Our results emphasize the variability associated with hydrologic processes around valley plugs and our rudimentary understanding of the effects associated with these geomorphic features. Water table levels were lower at valley plug sites compared to unchannelized sites, however, valley plug sites had a greater proportion of days when water table inundation was above mean root collar depth than both shoal and unchannelized sites as a result of lower root collar depths and higher deposition rates. This study has provided evidence that valley plugs can affect both surface and sub-surface hydrology in different ways than previously thought and illustrates the variability in hydrological responses to valley plug formation.

  4. Borehole plugging of man-made accesses to a basalt repository: a preliminary study

    International Nuclear Information System (INIS)

    Taylor, C.L.; Anttonen, G.J.; O'Rourke, J.E.; Niccum, M.R.

    1979-09-01

    This report describes the status of work currently in progress for the Basalt Borehole Plugging Program (BBPP). The primary objectives of the BBPP outlined in this report have been met during this first phase of work. These objectives included: (1) the preparation of a preliminary list of candidate plug materials; (2) a description of available machinery capable of placing candidate plug materials; and (3) the development of physical and geochemical testing programs to help evaluate the chemical stability and physical properties of candidate plug materials. The most significant finding from work to date is that given reasonable regulatory criteria, nothing has been identified which would prevent design of a plug system to seal manmade openings leading to a nuclear waste repository in Columbia River basalt for significantly long periods of time (on the order of thousands of years). Work accomplished to date indicates that this plug system can be designed using both natural and manufactured materials and can be emplaced with existing placement machinery and modifications of that machinery. The objectives of Task II are to conduct laboratory tests to evaluate the suitability of preferred candidate materials for plugging boreholes in the proposed repository, select plug system(s), initiate preconceptual machinery design for the placement of materials in plug system(s), and prepare a preliminary Task II report. As with Task I project organization, Task II is divided into subtasks that are identified by written subtask work summaries

  5. A Comparison of the Predicted Tube Plugging Rate for Alloy 600HTMA Steam Generator

    Energy Technology Data Exchange (ETDEWEB)

    Boo, Myung Hwan; Kang, Yong Seok [Korea Hydro and Nuclear Power Co., Daejeon (Korea, Republic of)

    2010-10-15

    To manage components that are used in long term operations such as steam generation, it is important to know the tube plugging rate, which can cause the performance degradation. The life of components can be predicted by the method using determinism and probability theory. With a method using probability theory, damage prediction of tube is possible. In this study, damage prediction for steam generation (SG) tube is performed using Weibull distribution and predicted plugging rate (life) is compared with the simple sum plugging number and case by case (failure cause) plugging number

  6. Apparatus for sealing a rotatable shield plug in a liquid metal nuclear reactor

    International Nuclear Information System (INIS)

    Winkleblack, R.K.

    1980-01-01

    An apparatus for sealing a rotatable shield plug in a nuclear reactor having liquid metal coolant is described. The apparatus includes a dip -ring seal adapted to provide a fluid barrier between the liquid metal and the atmosphere and to permit rotation of the shield plug. The apparatus also includes a static seal for the rotatable shield plug located between the dip-ring seal and the liquid metal. The static seal isolates the dip-ring seal from the liquid metal vapor during operation at power and can be disengaged for rotation of the shield plug

  7. Combustion aided by a glow plug in diesel engines under cold idling conditions

    OpenAIRE

    Li, Qile

    2016-01-01

    Glow plugs are widely used to promote the desired cold start and post-cold start combustion characteristics of light duty diesel engines. The importance of the glow plug becomes more apparent when the compression ratio is low. An experimental investigation of combustion initiation and development aided by the glow plug has been carried out on a single cylinder HPCR DI diesel engine with a low compression ratio of 15.5:1. High speed imaging of combustion initiated by the glow plug in a combust...

  8. A conceptual design of the ITER upper port plug structure and its cooling channels

    International Nuclear Information System (INIS)

    Pak, S.I.; Lee, H.G.; Jung, K.J.; Walker, C.I.; Kim, D.G.; Choi, K.S.

    2008-01-01

    A study is conducted on the conceptual design of the structure and cooling channels of the upper port plug of International Thermonuclear Experimental Reactor (ITER). Modification of the earlier port plug design is made and a simple fabrication method is proposed. It is shown that the newly designed port plug can accommodate the installation of both diagnostic and electron cyclotron heating (ECH) devices. Design assessment is carried out through structural and thermo-hydraulic analyses. Results of the analyses show that the port plug structure is stable against one of the most severe plasma events and the total pressure drop of the coolant is within the allowable level

  9. Potential formation in the plasma confinement region of a radio-frequency plugged linear device

    International Nuclear Information System (INIS)

    Fujita, Hideki; Kumazawa, Ryuhei; Howald, A.M.; Okamura, Shoichi; Sato, Teruyuki; Adati, Keizo; Garner, H.R.; Nishimura, Kiyohiko.

    1987-08-01

    Plasma potential formation in an open-ended plasma confinement system with RF plugging (the RFC-XX-M device) is investigated. The plasma potential in the central confinement region is measured with a heavy ion beam probe system and potentials at the RF plug section are measured with multi-grid energy analyzers. The measured plasma potential is compared with that deduced from the generalized Pastukhov formula. Results show that the plasma potential develops as an ambipolar potential to equate ion and electron end losses. During RF plugging, electrons are heated by Landau damping, while ions are not heated since adiabatic conditions apply during ion plugging in this experiment. (author)

  10. Reconstitutable control assembly having removable control rods with detachable split upper end plugs

    International Nuclear Information System (INIS)

    Gjertsen, R.K.; Knott, R.P.; Sparrow, J.A.

    1989-01-01

    This patent describes, in a reconstitutable control assembly for use with a nuclear fuel assembly, the control assembly including a spider structure and at least one control rod, an attachment joint for detachable fastening the control rod to the spider structure. The attachment joint comprising: a hollow connecting finger on the spider structure; and an elongated detachable split upper end plug on the control rod having a pair of separate upper and lower plug portions, the upper plug portion having integrally-connected tandemly- arranged upper, middle and lower sections. The lower plug portion having integrally-connected tandemly-arranged upper, middle and lower segments

  11. Development of expanded type plugging technique for leaky tubes of steam generators of Indian PHWRs

    International Nuclear Information System (INIS)

    Das, Nirupam; Samuel, K.A.; Joemon, V.; Rupani, B.B.

    2006-01-01

    Steam generators are very important component of Nuclear Power Plant (NPP), as they are part of Primary Heat Transport (PHT) system of Pressurised Heavy Water Reactors (PHWRs). A nuclear power plant of 220 MWe capacity has four mushroom type steam generators, each consisting of 1830 U-tubes (16 mm outside diameter and 1 mm wall thickness) made of Incoloy-800 material. The tubes of 'tube and shell type steam generator' act as the pressure boundary of PHT System. Any structural failure of these tubes may lead to release of radioactivity along with plant outage and significant economic loss. Hence, it is necessary to plug the leaky tubes for continued and safe operation of a steam generator. An expanded type plugging technique has been developed at Reactor Engineering Division to plug the leaky tubes. This plugging technique is selected because of low residual stress imparted in the adjacent 'tube to tube-sheet' joints. This plug meets the various codal requirements of steam generator. A number of qualification trials have been carried out with such plugs in the mock up facility. The expanded plugs meet the design requirements for pull out strength and leak-tightness. This paper describes the design concept of the plug, developmental aspects and qualification of the plugging technique. (author)

  12. Column Chromatography To Obtain Organic Cation Sorption Isotherms.

    Science.gov (United States)

    Jolin, William C; Sullivan, James; Vasudevan, Dharni; MacKay, Allison A

    2016-08-02

    Column chromatography was evaluated as a method to obtain organic cation sorption isotherms for environmental solids while using the peak skewness to identify the linear range of the sorption isotherm. Custom packed HPLC columns and standard batch sorption techniques were used to intercompare sorption isotherms and solid-water sorption coefficients (Kd) for four organic cations (benzylamine, 2,4-dichlorobenzylamine, phenyltrimethylammonium, oxytetracycline) with two aluminosilicate clay minerals and one soil. A comparison of Freundlich isotherm parameters revealed isotherm linearity or nonlinearity was not significantly different between column chromatography and traditional batch experiments. Importantly, skewness (a metric of eluting peak symmetry) analysis of eluting peaks can establish isotherm linearity, thereby enabling a less labor intensive means to generate the extensive data sets of linear Kd values required for the development of predictive sorption models. Our findings clearly show that column chromatography can reproduce sorption measures from conventional batch experiments with the benefit of lower labor-intensity, faster analysis times, and allow for consistent sorption measures across laboratories with distinct chromatography instrumentation.

  13. An Isothermal Steam Expander for an Industrial Steam Supplying System

    Directory of Open Access Journals (Sweden)

    Chen-Kuang Lin

    2015-01-01

    Full Text Available Steam is an essential medium used in the industrial process. To ensure steam quality, small and middle scale boilers are often adopted. However, because a higher steam pressure (compared to the necessary steam pressure is generated, the boiler’s steam pressure will be reduced via a pressure regulator before the steam is directed through the process. Unfortunately, pressure is somewhat wasted during the reducing process. Therefore, in order to promote energy efficiency, a pressure regulator is replaced by a steam expander. With this steam expander, the pressure will be transformed into mechanical energy and extracted during the expansion process. A new type of isothermal steam expander for an industrial steam supplying system will be presented in the paper. The isothermal steam expander will improve the energy efficiency of a traditional steam expander by replacing the isentropic process with an isothermal expansion process. With this, steam condensation will decrease, energy will increase, and steam quality will be improved. Moreover, the mathematical model of the isothermal steam expander will be established by using the Schmidt theory, the same principle used to analyze Stirling engines. Consequently, by verifying the correctness of the theoretical model for the isothermal steam expander using experimental data, a prototype of 100 c.c. isothermal steam expander is constructed.

  14. Integrated Microfluidic Nucleic Acid Isolation, Isothermal Amplification, and Amplicon Quantification

    Directory of Open Access Journals (Sweden)

    Michael G. Mauk

    2015-10-01

    Full Text Available Microfluidic components and systems for rapid (<60 min, low-cost, convenient, field-deployable sequence-specific nucleic acid-based amplification tests (NAATs are described. A microfluidic point-of-care (POC diagnostics test to quantify HIV viral load from blood samples serves as a representative and instructive example to discuss the technical issues and capabilities of “lab on a chip” NAAT devices. A portable, miniaturized POC NAAT with performance comparable to conventional PCR (polymerase-chain reaction-based tests in clinical laboratories can be realized with a disposable, palm-sized, plastic microfluidic chip in which: (1 nucleic acids (NAs are extracted from relatively large (~mL volume sample lysates using an embedded porous silica glass fiber or cellulose binding phase (“membrane” to capture sample NAs in a flow-through, filtration mode; (2 NAs captured on the membrane are isothermally (~65 °C amplified; (3 amplicon production is monitored by real-time fluorescence detection, such as with a smartphone CCD camera serving as a low-cost detector; and (4 paraffin-encapsulated, lyophilized reagents for temperature-activated release are pre-stored in the chip. Limits of Detection (LOD better than 103 virons/sample can be achieved. A modified chip with conduits hosting a diffusion-mode amplification process provides a simple visual indicator to readily quantify sample NA template. In addition, a companion microfluidic device for extracting plasma from whole blood without a centrifuge, generating cell-free plasma for chip-based molecular diagnostics, is described. Extensions to a myriad of related applications including, for example, food testing, cancer screening, and insect genotyping are briefly surveyed.

  15. The aspects regarding plugging the defective tubes of the steam generator using plastic deformation of the plug wall by conventional or unconventional techniques

    International Nuclear Information System (INIS)

    Gyongyosi, Tiberiu

    2006-01-01

    After a brief introduction the advantages and disadvantages of two plugging methods of the defective tubes from steam generator by plastic deformation of the wall of the plug, deformation performed by mechanical rolling (conventional technique) and by electrohydraulic shock (unconventional technique), respectively, are showed. The paper gives the results of the experimental tests to install the plugs at the end of the tube having the same geometry with those of the steam generator, the performance reached in this stage and some conclusions in the end

  16. Numerical study of inflow conditions on a turbulent isothermal or heated plane jet; Etude numerique des conditions d'emission sur un ecoulement de type jet plan turbulent isotherme ou chauffe

    Energy Technology Data Exchange (ETDEWEB)

    Mhiri, H.; Habli, S.; El Golli, S. [Ecole Nationale d' Ingenieurs de Monastir (Tunisia); Le Palec, G.; Bournot, Ph. [Institut de Mecanique de Marseille (France)

    1999-11-01

    We intend to solve equations governing turbulent plane-vertical isotherm and non isotherm jets by taking into account inflow conditions at the exit of the nozzle. The analysis is focused on the influence of these conditions on this type of flow. Two cases are considered (uniform and parabolic velocity and temperature profiles). A finite difference scheme is developed to solve the governing equations. This numeric model allows us to show that the region of fully developed regime begins much nearer the nozzle for the turbulent case than for the laminar flow case. Indeed, the turbulence increases the mixing between the incoming gas from the nozzle and the ambient fluid, and consequently the size of the potential core zone decreases. The results are compared to other works introducing mathematical variables based on the energy conservation for the case of the mixed convection and the momentum conservation for the forced convection, which allows the validation of our results. (authors)

  17. Critical flow rate in a single phase flow. Blocking concept

    International Nuclear Information System (INIS)

    Giot, Michel

    1978-01-01

    After referring to the phenomena accompanying the appearance of a critical flow rate in a nozzle and presenting equations governing single phase flows, the critical condition is defined. Several particular cases are then examined; the horizontal and vertical isentropic flow, Fanno's flow and Raleigh's and the isothermal flow. The entropy deviation is calculated on either side of a normal impact. To conclude, the link existing between the concepts of critical flow and the propagation rate of small perturbations is demonstrated. To do so, the method of perturbations, that of Prandtl and that of characteristic directions are applied in turn [fr

  18. Petrographic study of core plugs from lower goru sandstones

    International Nuclear Information System (INIS)

    Memon, M.K.; Tunio, A.; Leghari, A.

    2008-01-01

    Petrographic rock type description is a fundamental component in the reservoir description processes and typically included measurement to identify sediment source, texture, composition and mineralogy. Petroleum workers have long used the Petrographic microscope as an in put device to aid in the study of pore systems. Standard Petrographic thin sections are typically 30 micrometers thick and are usually illuminated by transmitted light. Experienced examiners have trained themselves to see information such as pore size, mineralogy, compaction, etc by disregarding artifacts produced by passing light through a section. This method is adequate for qualitative interpretation of data from thin sections. Rocks in thin section under a microscope display great complexity in pore sizes and shapes. Petrographic study provides measurement on rock texture. Texture deals with the size, shape and arrangement of the component minerals of a rock. It is essentially the micro geometry of the rock. Permeability of collected core plugs of lower Goru sandstones was measured. From this Petrographic study we have identified as the sandstone of Lower Goru constitute almost entirely of quartz. The grains range in size from very fine to medium, moderately well sorted to well sorted and rounded to sub rounded in shape. Particularly attention was paid to mineral content present in Lower Goru Sandstone. The mineral composition from these core plugs of Lower Goru Sandstone as identified contain about 70-80% Quartz with traces of feldspar, muscovite, biotite, Epidote and hornblende. Calcite was present as cementing material and it was about 15 -30% of the total rock. (author)

  19. The newly developed Toyota plug-in hybrid system

    Energy Technology Data Exchange (ETDEWEB)

    Takaoka, Toshifumi; Ichinose, Hiroki [Toyota Motor Corporation (Japan)

    2010-07-01

    Toyota has been introducing several hybrid vehicles (HV) as a countermeasure to the automobile's concerns, like CO2 reduction, energy security, and emission reduction in urban areas. A next step towards an even more effective solution for these concerns is a plug-in hybrid vehicle (PHV). This vehicle combines the advantages of electric vehicles (EV), which use clean electric energy, and HV, with it's high environmental potential and user- friendliness comparable to conventional vehicles, such as a long cruising range. This paper describes a newly developed plug-in hybrid system and its vehicle performance. This system uses a Li-ion battery with high energy density and has an affordable EV range without sacrificing cabin space. The vehicle achieves a CO2 emission of 59g/km and meets the most stringent emission regulations in the world. The new PHV is a forerunner of the large-scale mass production PHV two years later. PHVs have the potential to become popular as a realistic solution towards sustainable mobility by renewable electricity usage in the future. (orig.)

  20. Selecting Female Mice in Estrus and Checking Plugs.

    Science.gov (United States)

    Behringer, Richard; Gertsenstein, Marina; Nagy, Kristina Vintersten; Nagy, Andras

    2016-08-01

    The female mouse estrous cycle is divided into four phases: proestrus (development of ovarian follicles), estrus (ovulation), metestrus (formation of corpora lutea), and diestrus (beginning of follicle development for next ovulation and elimination of previous oocytes). The appearance of the epithelium of the external genitalia is used to identify the stage of the estrous cycle of a female mouse. This is usually easier to see in strains with either no or only light skin pigmentation. By examining the color, moistness, and degree of swelling of the vagina, females in estrus can readily be identified. To set up the matings, females are examined in the afternoon, and those in estrus are placed into the cages with males (one or two females in each cage with one male). Usually, 50% or more of the selected females will mate. The presence of a vaginal copulation plug next morning indicates that mating has occurred, but it does not mean that a pregnancy will result even if proven breeder fertile males were used. It is important to check vaginal plugs early in the morning because they fall out or are no longer detectable ~12 h after mating or sometimes earlier. © 2016 Cold Spring Harbor Laboratory Press.