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Sample records for immiscible fluids passing

  1. Immiscible multicomponent lattice Boltzmann model for fluids with ...

    Indian Academy of Sciences (India)

    College of Mechanical Engineering, Tongji University, 4800# Cao'an Road, ... was developed from a discretized fluid model known as the lattice gas automata ... of two immiscible fluids, several lattice Boltzmann (LB) models have been ...

  2. Multiphase flow of immiscible fluids on unstructured moving meshes

    DEFF Research Database (Denmark)

    Misztal, Marek Krzysztof; Erleben, Kenny; Bargteil, Adam

    2012-01-01

    In this paper, we present a method for animating multiphase flow of immiscible fluids using unstructured moving meshes. Our underlying discretization is an unstructured tetrahedral mesh, the deformable simplicial complex (DSC), that moves with the flow in a Lagrangian manner. Mesh optimization op...

  3. Mixed convective flow of immiscible viscous fluids confined between ...

    African Journals Online (AJOL)

    user

    International Journal of Engineering, Science and Technology ... finite difference methods to analyze the problem of natural convection boundary layer flow along a complex vertical surface ... analyzed the flow of two immiscible fluids in a parallel plate channel ... wavy and flat walls are maintained at constant temperatures w.

  4. Multiphase Flow of Immiscible Fluids on Unstructured Moving Meshes

    DEFF Research Database (Denmark)

    Misztal, Marek Krzysztof; Erleben, Kenny; Bargteil, Adam

    2013-01-01

    In this paper, we present a method for animating multiphase flow of immiscible fluids using unstructured moving meshes. Our underlying discretization is an unstructured tetrahedral mesh, the deformable simplicial complex (DSC), that moves with the flow in a Lagrangian manner. Mesh optimization op...

  5. Local lattice-gas model for immiscible fluids

    International Nuclear Information System (INIS)

    Chen, S.; Doolen, G.D.; Eggert, K.; Grunau, D.; Loh, E.Y.

    1991-01-01

    We present a lattice-gas model for two-dimensional immiscible fluid flows with surface tension that uses strictly local collision rules. Instead of using a local total color flux as Somers and Rem [Physica D 47, 39 (1991)], we use local colored holes to be the memory of particles of the same color. Interactions between walls and fluids are included that produce arbitrary contact angles

  6. Mixing of immiscible fluids in chaotic flows and related issues

    International Nuclear Information System (INIS)

    Ottino, J.M.

    1993-01-01

    The basis goal of this work was to obtain a basic understanding of mixing of immiscible fluids leading to the determination of flow conditions which result in efficient breakup and dispersion of one mass of fluid in the bulk of another. Related issues were the prediction of the morphological structures and drop size distribution for a given set of operating conditions. The primary motivation for these investigations was to produce basic knowledge leading to increased understanding of industrial processes involving blending, agitation, emulsification, and dissolution

  7. Immiscible two-phase fluid flows in deformable porous media

    Science.gov (United States)

    Lo, Wei-Cheng; Sposito, Garrison; Majer, Ernest

    Macroscopic differential equations of mass and momentum balance for two immiscible fluids in a deformable porous medium are derived in an Eulerian framework using the continuum theory of mixtures. After inclusion of constitutive relationships, the resulting momentum balance equations feature terms characterizing the coupling among the fluid phases and the solid matrix caused by their relative accelerations. These terms, which imply a number of interesting phenomena, do not appear in current hydrologic models of subsurface multiphase flow. Our equations of momentum balance are shown to reduce to the Berryman-Thigpen-Chen model of bulk elastic wave propagation through unsaturated porous media after simplification (e.g., isothermal conditions, neglect of gravity, etc.) and under the assumption of constant volume fractions and material densities. When specialized to the case of a porous medium containing a single fluid and an elastic solid, our momentum balance equations reduce to the well-known Biot model of poroelasticity. We also show that mass balance alone is sufficient to derive the Biot model stress-strain relations, provided that a closure condition for porosity change suggested by de la Cruz and Spanos is invoked. Finally, a relation between elastic parameters and inertial coupling coefficients is derived that permits the partial differential equations of the Biot model to be decoupled into a telegraph equation and a wave equation whose respective dependent variables are two different linear combinations of the dilatations of the solid and the fluid.

  8. Particle Swarm Transport through Immiscible Fluid Layers in a Fracture

    Science.gov (United States)

    Teasdale, N. D.; Boomsma, E.; Pyrak-Nolte, L. J.

    2011-12-01

    Immiscible fluids occur either naturally (e.g. oil & water) or from anthropogenic processes (e.g. liquid CO2 & water) in the subsurface and complicate the transport of natural or engineered micro- or nano-scale particles. In this study, we examined the effect of immiscible fluids on the formation and evolution of particle swarms in a fracture. A particle swarm is a collection of colloidal-size particles in a dilute suspension that exhibits cohesive behavior. Swarms fall under gravity with a velocity that is greater than the settling velocity of a single particle. Thus a particle swarm of colloidal contaminants can potentially travel farther and faster in a fracture than expected for a dispersion or emulsion of colloidal particles. We investigated the formation, evolution, and break-up of colloidal swarms under gravity in a uniform aperture fracture as hydrophobic/hydrophyllic particle swarms move across an oil-water interface. A uniform aperture fracture was fabricated from two transparent acrylic rectangular prisms (100 mm x 50 mm x 100 mm) that are separated by 1, 2.5, 5, 10 or 50 mm. The fracture was placed, vertically, inside a glass tank containing a layer of pure silicone oil (polydimethylsiloxane) on distilled water. Along the length of the fracture, 30 mm was filled with oil and 70 mm with water. Experiments were conducted using silicone oils with viscosities of 5, 10, 100, or 1000 cSt. Particle swarms (5 μl) were comprised of a 1% concentration (by mass) of 25 micron glass beads (hydrophilic) suspended in a water drop, or a 1% concentration (by mass) of 3 micron polystyrene fluorescent beads (hydrophobic) suspended in a water drop. The swarm behavior was imaged using an optical fluorescent imaging system composed of a CCD camera and by green (525 nm) LED arrays for illumination. Swarms were spherical and remained coherent as they fell through the oil because of the immiscibility of oil and water. However, as a swarm approached the oil-water interface, it

  9. A novel coarsening mechanism of droplets in immiscible fluid mixtures

    Science.gov (United States)

    Shimizu, Ryotaro; Tanaka, Hajime

    2015-06-01

    In our daily lives, after shaking a salad dressing, we see the coarsening of oil droplets suspended in vinegar. Such a demixing process is observed everywhere in nature and also of technological importance. For a case of high droplet density, domain coarsening proceeds with inter-droplet collisions and the resulting coalescence. This phenomenon has been explained primarily by the so-called Brownian-coagulation mechanism: stochastic thermal forces exerted by molecules induce random motion of individual droplets, causing accidental collisions and subsequent interface-tension-driven coalescence. Contrary to this, here we demonstrate that the droplet motion is not random, but hydrodynamically driven by the composition Marangoni force due to an interfacial tension gradient produced in each droplet as a consequence of composition correlation among droplets. This alters our physical understanding of droplet coarsening in immiscible liquid mixtures on a fundamental level.

  10. Experiments and MPS analysis of stratification behavior of two immiscible fluids

    Energy Technology Data Exchange (ETDEWEB)

    Li, Gen, E-mail: ligen@fuji.waseda.jp [Cooperative Major in Nuclear Energy, Waseda University, 3-4-1, Okubo, Shinjuku-ku, Tokyo 169-8555 (Japan); Oka, Yoshiaki [Cooperative Major in Nuclear Energy, Waseda University, 3-4-1, Okubo, Shinjuku-ku, Tokyo 169-8555 (Japan); Furuya, Masahiro; Kondo, Masahiro [Nuclear Technology Research Laboratory, Central Research Institute of Electric Power Industry (CRIEPI), 2-11-1 Iwado-kita, Komae, Tokyo 201-8511 (Japan)

    2013-12-15

    Highlights: • Improving numerical stability of MPS method. • Implicitly calculating viscous term in momentum equation for highly viscous fluids. • Validation of the enhanced MPS method by analyzing dam break problem. • Various stratification behavior analysis by experiments and simulations. • Sensitivity analysis of the effects of the fluid viscosity and density difference. - Abstract: Stratification behavior is of great significance in the late in-vessel stage of core melt severe accident of a nuclear reactor. Conventional numerical methods have difficulties in analyzing stratification process accompanying with free surface without depending on empirical correlations. The Moving Particle Semi-implicit (MPS) method, which calculates free surface and multiphase flow without empirical equations, is applicable for analyzing the stratification behavior of fluids. In the present study, the original MPS method was improved to simulate the stratification behavior of two immiscible fluids. The improved MPS method was validated through simulating classical dam break problem. Then, the stratification processes of two fluid columns and injected fluid were investigated through experiments and simulations, using silicone oil and salt water as the simulant materials. The effects of fluid viscosity and density difference on stratification behavior were also sensitively investigated by simulations. Typical fluid configurations at various parametric and geometrical conditions were observed and well predicted by improved MPS method.

  11. Seismoelectric couplings in a poroelastic material containing two immiscible fluid phases

    Science.gov (United States)

    Jardani, A.; Revil, A.

    2015-08-01

    A new approach of seismoelectric imaging has been recently proposed to detect saturation fronts in which seismic waves are focused in the subsurface to scan its heterogeneous nature and determine saturation fronts. Such type of imaging requires however a complete modelling of the seismoelectric properties of porous media saturated by two immiscible fluid phases, one being usually electrically insulating (for instance water and oil). We combine an extension of Biot dynamic theory, valid for porous media containing two immiscible Newtonian fluids, with an extension of the electrokinetic theory based on the notion of effective volumetric charge densities dragged by the flow of each fluid phase. These effective charge densities can be related directly to the permeability and saturation of each fluid phase. The coupled partial differential equations are solved with the finite element method. We also derive analytically the transfer function connecting the macroscopic electrical field to the acceleration of the fast P wave (coseismic electrical field) and we study the influence of the water content on this coupling. We observe that the amplitude of the co-seismic electrical disturbance is very sensitive to the water content with an increase in amplitude with water saturation. We also investigate the seismoelectric conversions (interface effect) occurring at the water table. We show that the conversion response at the water table can be identifiable only when the saturation contrasts between the vadose and saturated zones are sharp enough. A relatively dry vadose zone represents the best condition to identify the water table through seismoelectric measurements. Indeed, in this case, the coseismic electrical disturbances are vanishingly small compared to the seismoelectric interface response.

  12. Stability conditions of stationary rupture of liquid layers on an immiscible fluid surface

    Energy Technology Data Exchange (ETDEWEB)

    Viviani, A. [Seconda Univ. di Napoli, Aversa (Italy). Facolta di Ingegneria; Kostarev, K.; Shmyrov, A.; Zuev, A. [Inst. of Continuous Media Mechanics, Perm (Russian Federation)

    2009-07-01

    The stationary equilibrium shape of a 3-phase liquids-gas system was investigated. The system consisted of a horizontal liquid layer with an upper free boundary placed on the immiscible fluid interface. The study investigated the stability conditions of rupture of the liquid layer surface. The dependence of rupture parameters on the experimental cuvette diameter and layer thickness was investigated, as well as the difference in the values of surface tension of the examined fluids. The 2-layer system of horizontal fluid layers was formed in a glass cylindrical cuvette. The liquid substrate was tetrachloride carbon (CCI{sub 4}), while upper layers included water, glycerine, ethyleneglycol, and aqueous solutions of 1,4-butanediol C{sub 4}H{sub 10}O{sub 2} and isopropanol C{sub 3H8L}. Initially, the surface of the substrate fluid was overlaid with a horizontal liquid layer. The rupture was formed by subjecting the layer surface to short-time actions of a narrow directional air jet. After rupture formation, the layer thickness increased gradually. The measurements demonstrated that the rupture diameter depends on the initial thickness of the upper layer as well as the diameter of the cuvette, and the difference in the values of the surface tension of the examined fluids. Analysis of the experimental relationships indicated that the critical thickness of the breaking layer is a constant value for any specific pairs of fluids. 4 refs., 7 figs.

  13. Small and large amplitude movement of the unstable interface between two immiscible fluids

    Energy Technology Data Exchange (ETDEWEB)

    Aribert, J M; Thirriot, C

    1970-01-01

    The flow of immiscible fluids in a confined flow channel is accompanied by a deformation of the surface of separation when the stability conditions are not fulfilled. A simplified schematic for the problem is given, and the characteristic surface perturbation is calculated analytically and numerically. The perturbation is characterized by a wavelength, an amplitude, and the shape of the perturbation at a sufficient distance from the front. Two asymptotic cases are fully discussed: the creation of a wave in the surface, and the shape of a fully developed perturbation. Experimental results from 2 Hele-Shaw models are in satisfactory agreement with the theoretical predictions. Further studies will be concerned with variable rate flow, geometrically divergent flow, layered flow with variable viscosity between layers, and non-Newtonian flow.

  14. Lattice Boltzmann simulation of immiscible fluid displacement in porous media: Homogeneous versus heterogeneous pore network

    International Nuclear Information System (INIS)

    Liu, Haihu; Zhang, Yonghao; Valocchi, Albert J.

    2015-01-01

    Injection of anthropogenic carbon dioxide (CO 2 ) into geological formations is a promising approach to reduce greenhouse gas emissions into the atmosphere. Predicting the amount of CO 2 that can be captured and its long-term storage stability in subsurface requires a fundamental understanding of multiphase displacement phenomena at the pore scale. In this paper, the lattice Boltzmann method is employed to simulate the immiscible displacement of a wetting fluid by a non-wetting one in two microfluidic flow cells, one with a homogeneous pore network and the other with a randomly heterogeneous pore network. We have identified three different displacement patterns, namely, stable displacement, capillary fingering, and viscous fingering, all of which are strongly dependent upon the capillary number (Ca), viscosity ratio (M), and the media heterogeneity. The non-wetting fluid saturation (S nw ) is found to increase nearly linearly with logCa for each constant M. Increasing M (viscosity ratio of non-wetting fluid to wetting fluid) or decreasing the media heterogeneity can enhance the stability of the displacement process, resulting in an increase in S nw . In either pore networks, the specific interfacial length is linearly proportional to S nw during drainage with equal proportionality constant for all cases excluding those revealing considerable viscous fingering. Our numerical results confirm the previous experimental finding that the steady state specific interfacial length exhibits a linear dependence on S nw for either favorable (M ≥ 1) or unfavorable (M < 1) displacement, and the slope is slightly higher for the unfavorable displacement

  15. Low-frequency dilatational wave propagation through unsaturated porous media containing two immiscible fluids

    Energy Technology Data Exchange (ETDEWEB)

    Lo, W.-C.; Sposito, G.; Majer, E.

    2007-02-01

    An analytical theory is presented for the low-frequency behavior of dilatational waves propagating through a homogeneous elastic porous medium containing two immiscible fluids. The theory is based on the Berryman-Thigpen-Chin (BTC) model, in which capillary pressure effects are neglected. We show that the BTC model equations in the frequency domain can be transformed, at sufficiently low frequencies, into a dissipative wave equation (telegraph equation) and a propagating wave equation in the time domain. These partial differential equations describe two independent modes of dilatational wave motion that are analogous to the Biot fast and slow compressional waves in a single-fluid system. The equations can be solved analytically under a variety of initial and boundary conditions. The stipulation of 'low frequency' underlying the derivation of our equations in the time domain is shown to require that the excitation frequency of wave motions be much smaller than a critical frequency. This frequency is shown to be the inverse of an intrinsic time scale that depends on an effective kinematic shear viscosity of the interstitial fluids and the intrinsic permeability of the porous medium. Numerical calculations indicate that the critical frequency in both unconsolidated and consolidated materials containing water and a nonaqueous phase liquid ranges typically from kHz to MHz. Thus engineering problems involving the dynamic response of an unsaturated porous medium to low excitation frequencies (e.g. seismic wave stimulation) should be accurately modeled by our equations after suitable initial and boundary conditions are imposed.

  16. Structure-Preserving Methods for the Navier-Stokes-Cahn-Hilliard System to Model Immiscible Fluids

    KAUST Repository

    Sarmiento, Adel F.

    2017-12-03

    This work presents a novel method to model immiscible incompressible fluids in a stable manner. Here, the immiscible behavior of the flow is described by the incompressible Navier-Stokes-Cahn-Hilliard model, which is based on a diffuse interface method. We introduce buoyancy effects in the model through the Boussinesq approximation in a consistent manner. A structure-preserving discretization is used to guarantee the linear stability of the discrete problem and to satisfy the incompressibility of the discrete solution at every point in space by construction. For the solution of the model, we developed the Portable Extensible Toolkit for Isogeometric Analysis with Multi-Field discretizations (PetIGA-MF), a high-performance framework that supports structure-preserving spaces. PetIGA-MF is built on top of PetIGA and the Portable Extensible Toolkit for Scientific Computation (PETSc), sharing all their user-friendly, performance, and flexibility features. Herein, we describe the implementation of our model in PetIGA-MF and the details of the numerical solution. With several numerical tests, we verify the convergence, scalability, and validity of our approach. We use highly-resolved numerical simulations to analyze the merging and rising of droplets. From these simulations, we detailed the energy exchanges in the system to evaluate quantitatively the quality of our simulations. The good agreement of our results when compared against theoretical descriptions of the merging, and the small errors found in the energy analysis, allow us to validate our approach. Additionally, we present the development of an unconditionally energy-stable generalized-alpha method for the Swift-Hohenberg model that offers control over the numerical dissipation. A pattern formation example demonstrates the energy-stability and convergence of our method.

  17. Lattice Boltzmann simulation of immiscible fluid displacement in porous media: Homogeneous versus heterogeneous pore network

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Haihu, E-mail: haihu.liu@mail.xjtu.edu.cn [School of Energy and Power Engineering, Xi’an Jiaotong University, 28 West Xianning Road, Xi’an 710049 (China); James Weir Fluids Laboratory, Department of Mechanical and Aerospace Engineering, University of Strathclyde, Glasgow G1 1XJ (United Kingdom); Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Zhang, Yonghao [James Weir Fluids Laboratory, Department of Mechanical and Aerospace Engineering, University of Strathclyde, Glasgow G1 1XJ (United Kingdom); Valocchi, Albert J. [Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States)

    2015-05-15

    Injection of anthropogenic carbon dioxide (CO{sub 2}) into geological formations is a promising approach to reduce greenhouse gas emissions into the atmosphere. Predicting the amount of CO{sub 2} that can be captured and its long-term storage stability in subsurface requires a fundamental understanding of multiphase displacement phenomena at the pore scale. In this paper, the lattice Boltzmann method is employed to simulate the immiscible displacement of a wetting fluid by a non-wetting one in two microfluidic flow cells, one with a homogeneous pore network and the other with a randomly heterogeneous pore network. We have identified three different displacement patterns, namely, stable displacement, capillary fingering, and viscous fingering, all of which are strongly dependent upon the capillary number (Ca), viscosity ratio (M), and the media heterogeneity. The non-wetting fluid saturation (S{sub nw}) is found to increase nearly linearly with logCa for each constant M. Increasing M (viscosity ratio of non-wetting fluid to wetting fluid) or decreasing the media heterogeneity can enhance the stability of the displacement process, resulting in an increase in S{sub nw}. In either pore networks, the specific interfacial length is linearly proportional to S{sub nw} during drainage with equal proportionality constant for all cases excluding those revealing considerable viscous fingering. Our numerical results confirm the previous experimental finding that the steady state specific interfacial length exhibits a linear dependence on S{sub nw} for either favorable (M ≥ 1) or unfavorable (M < 1) displacement, and the slope is slightly higher for the unfavorable displacement.

  18. A study on the unsteady flow of two immiscible micropolar and Newtonian fluids through a horizontal channel: A numerical approach

    Science.gov (United States)

    Devakar, M.; Raje, Ankush

    2018-05-01

    The unsteady flow of two immiscible micropolar and Newtonian fluids through a horizontal channel is considered. In addition to the classical no-slip and hyper-stick conditions at the boundary, it is assumed that the fluid velocities and shear stresses are continuous across the fluid-fluid interface. Three cases for the applied pressure gradient are considered to study the problem: one with constant pressure gradient and the other two cases with time-dependent pressure gradients, viz. periodic and decaying pressure gradient. The Crank-Nicolson approach has been used to obtain numerical solutions for fluid velocity and microrotation for diverse sets of fluid parameters. The nature of fluid velocities and microrotation with various values of pressure gradient, Reynolds number, ratio of viscosities, micropolarity parameter and time is illustrated through graphs. It has been observed that micropolarity parameter and ratio of viscosities reduce the fluid velocities.

  19. Stochastic porous media modeling and high-resolution schemes for numerical simulation of subsurface immiscible fluid flow transport

    Science.gov (United States)

    Brantson, Eric Thompson; Ju, Binshan; Wu, Dan; Gyan, Patricia Semwaah

    2018-04-01

    This paper proposes stochastic petroleum porous media modeling for immiscible fluid flow simulation using Dykstra-Parson coefficient (V DP) and autocorrelation lengths to generate 2D stochastic permeability values which were also used to generate porosity fields through a linear interpolation technique based on Carman-Kozeny equation. The proposed method of permeability field generation in this study was compared to turning bands method (TBM) and uniform sampling randomization method (USRM). On the other hand, many studies have also reported that, upstream mobility weighting schemes, commonly used in conventional numerical reservoir simulators do not accurately capture immiscible displacement shocks and discontinuities through stochastically generated porous media. This can be attributed to high level of numerical smearing in first-order schemes, oftentimes misinterpreted as subsurface geological features. Therefore, this work employs high-resolution schemes of SUPERBEE flux limiter, weighted essentially non-oscillatory scheme (WENO), and monotone upstream-centered schemes for conservation laws (MUSCL) to accurately capture immiscible fluid flow transport in stochastic porous media. The high-order schemes results match well with Buckley Leverett (BL) analytical solution without any non-oscillatory solutions. The governing fluid flow equations were solved numerically using simultaneous solution (SS) technique, sequential solution (SEQ) technique and iterative implicit pressure and explicit saturation (IMPES) technique which produce acceptable numerical stability and convergence rate. A comparative and numerical examples study of flow transport through the proposed method, TBM and USRM permeability fields revealed detailed subsurface instabilities with their corresponding ultimate recovery factors. Also, the impact of autocorrelation lengths on immiscible fluid flow transport were analyzed and quantified. A finite number of lines used in the TBM resulted into visual

  20. Numerical simulations of negatively buoyant jets in an immiscible fluid using the Particle Finite Element Method

    Science.gov (United States)

    Mier-Torrecilla, Monica; Geyer, Adelina; Phillips, Jeremy C.; Idelsohn, Sergio R.; Oñate, Eugenio

    2010-05-01

    In this work we investigate numerically the injection of a negatively buoyant jet into a homogenous immiscible ambient fluid using the Particle Finite Element Method (PFEM), a newly developed tool that combines the flexibility of particle-based methods with the accuracy of the finite element discretization. In order to test the applicability of PFEM to the study of negatively buoyant jets, we have compared the two-dimensional numerical results with experiments investigating the injection of a jet of dyed water through a nozzle in the base of a cylindrical tank containing rapeseed oil. In both simulations and experiments, the fountain inlet flow velocity and nozzle diameter were varied to cover a wide range of Reynolds Re and Froude numbers Fr, such that 0.1 < Fr < 30, reproducing both weak and strong fountains in a laminar regime (8 < Re < 1350). Numerical results, together with the experimental observations, allow us to describe three different fountain behaviors that have not been previously reported. Based on the Re and Fr values for the numerical and experimental simulations, we have built a regime map to define how these values may control the occurrence of each of the observed flow types. Whereas the Fr number itself provides a prediction of the maximum penetration height of the jet, its combination with the Re number provides a prediction of the flow behavior for a specific nozzle diameter and injection velocity. Conclusive remarks concerning the dynamics of negatively buoyant jets may be applied later on to several geological situations, e.g. the flow structure of a fully submerged subaqueous eruptive vent discharging magma or the replenishment of magma chambers in the Earth's crust.

  1. Method and apparatus for purifying nucleic acids and performing polymerase chain reaction assays using an immiscible fluid

    Energy Technology Data Exchange (ETDEWEB)

    Koh, Chung-Yan; Light, Yooli Kim; Piccini, Matthew Ernest; Singh, Anup K.

    2017-10-31

    Embodiments of the present invention are directed toward devices, systems, and methods for purifying nucleic acids to conduct polymerase chain reaction (PCR) assays. In one example, a method includes generating complexes of silica beads and nucleic acids in a lysis buffer, transporting the complexes through an immiscible fluid to remove interfering compounds from the complexes, further transporting the complexes into a density medium containing components required for PCR where the nucleic acids disassociate from the silica beads, and thermocycling the contents of the density medium to achieve PCR. Signal may be detected from labeling agents in the components required for PCR.

  2. Flow of two immiscible fluids in a periodically constricted tube: Transitions to stratified, segmented, churn, spray or segregated flow

    Science.gov (United States)

    Tsamopoulos, John; Fraggedakis, Dimitris; Dimakopoulos, Yiannis

    2015-11-01

    We study the flow of two immiscible, Newtonian fluids in a periodically constricted tube driven by a constant pressure gradient. Our Volume-of-Fluid algorithm is used to solve the governing equations. First the code is validated by comparing its predictions to previously reported results for stratified and pulsing flow. Then it is used to capture accurately all the significant topological changes that take place. Initially, the fluids have a core-annular arrangement, which is found to either remain the same or change to a different arrangement depending on the fluid properties, the pressure driving the flow or the flow geometry. The flow-patterns that appear are the core-annular, segmented, churn, spray and segregated flow. The predicted scalings near pinching of the core fluid concur with similarity predictions and earlier numerical results (Cohen et al. (1999)). Flow-pattern maps are constructed in terms of the Reynolds and Weber numbers. Our results provide deeper insights in the mechanism of the pattern transitions and are in agreement with previous studies on core-annular flow (Kouris & Tsamopoulos (2001 & 2002)), segmented flow (Lac & Sherwood (2009)) and churn flow (Bai et al. (1992)). GSRT of Greece through the program ``Excellence'' (Grant No. 1918, entitled ``FilCoMicrA'').

  3. Multiphase flows of N immiscible incompressible fluids: A reduction-consistent and thermodynamically-consistent formulation and associated algorithm

    Science.gov (United States)

    Dong, S.

    2018-05-01

    We present a reduction-consistent and thermodynamically consistent formulation and an associated numerical algorithm for simulating the dynamics of an isothermal mixture consisting of N (N ⩾ 2) immiscible incompressible fluids with different physical properties (densities, viscosities, and pair-wise surface tensions). By reduction consistency we refer to the property that if only a set of M (1 ⩽ M ⩽ N - 1) fluids are present in the system then the N-phase governing equations and boundary conditions will exactly reduce to those for the corresponding M-phase system. By thermodynamic consistency we refer to the property that the formulation honors the thermodynamic principles. Our N-phase formulation is developed based on a more general method that allows for the systematic construction of reduction-consistent formulations, and the method suggests the existence of many possible forms of reduction-consistent and thermodynamically consistent N-phase formulations. Extensive numerical experiments have been presented for flow problems involving multiple fluid components and large density ratios and large viscosity ratios, and the simulation results are compared with the physical theories or the available physical solutions. The comparisons demonstrate that our method produces physically accurate results for this class of problems.

  4. Simulation results for a multirate mass transfer modell for immiscible displacement of two fluids in highly heterogeneous porous media

    Science.gov (United States)

    Tecklenburg, Jan; Neuweiler, Insa; Dentz, Marco; Carrera, Jesus; Geiger, Sebastian

    2013-04-01

    Flow processes in geotechnical applications do often take place in highly heterogeneous porous media, such as fractured rock. Since, in this type of media, classical modelling approaches are problematic, flow and transport is often modelled using multi-continua approaches. From such approaches, multirate mass transfer models (mrmt) can be derived to describe the flow and transport in the "fast" or mobile zone of the medium. The porous media is then modeled with one mobile zone and multiple immobile zones, where the immobile zones are connected to the mobile zone by single rate mass transfer. We proceed from a mrmt model for immiscible displacement of two fluids, where the Buckley-Leverett equation is expanded by a sink-source-term which is nonlocal in time. This sink-source-term models exchange with an immobile zone with mass transfer driven by capillary diffusion. This nonlinear diffusive mass transfer can be approximated for particular imbibition or drainage cases by a linear process. We present a numerical scheme for this model together with simulation results for a single fracture test case. We solve the mrmt model with the finite volume method and explicit time integration. The sink-source-term is transformed to multiple single rate mass transfer processes, as shown by Carrera et. al. (1998), to make it local in time. With numerical simulations we studied immiscible displacement in a single fracture test case. To do this we calculated the flow parameters using information about the geometry and the integral solution for two phase flow by McWorther and Sunnada (1990). Comparision to the results of the full two dimensional two phase flow model by Flemisch et. al. (2011) show good similarities of the saturation breakthrough curves. Carrera, J., Sanchez-Vila, X., Benet, I., Medina, A., Galarza, G., and Guimera, J.: On matrix diffusion: formulations, solution methods and qualitative effects, Hydrogeology Journal, 6, 178-190, 1998. Flemisch, B., Darcis, M

  5. Axisymmetric capillary-gravity waves at the interface of two viscous, immiscible fluids - Initial value problem

    Science.gov (United States)

    Farsoiya, Palas Kumar; Dasgupta, Ratul

    2017-11-01

    When the interface between two radially unbounded, viscous fluids lying vertically in a stable configuration (denser fluid below) at rest, is perturbed, radially propagating capillary-gravity waves are formed which damp out with time. We study this process analytically using a recently developed linearised theory. For small amplitude initial perturbations, the analytical solution to the initial value problem, represented as a linear superposition of Bessel modes at time t = 0 , is found to agree very well with results obtained from direct numerical simulations of the Navier-Stokes equations, for a range of initial conditions. Our study extends the earlier work by John W. Miles who studied this initial value problem analytically, taking into account, a single viscous fluid only. Implications of this study for the mechanistic understanding of droplet impact into a deep pool, will be discussed. Some preliminary, qualitative comparison with experiments will also be presented. We thank SERB Dept. Science & Technology, Govt. of India, Grant No. EMR/2016/000830 for financial support.

  6. Etude d'un modele de Boltzmann sur reseau pour la simulation assistee par ordinateur des fluides a plusieurs phases immiscibles

    Science.gov (United States)

    Leclaire, Sebastien

    The computer assisted simulation of the dynamics of fluid flow has been a highly rewarding topic of research for several decades now, in terms of the number of scientific problems that have been solved as a result, both in the academic world and in industry. In the fluid dynamics field, simulating multiphase immiscible fluid flow remains a challenge, because of the complexity of the interactions at the flow phase interfaces. Various numerical methods are available to study these phenomena, and, the lattice Boltzmann method has been shown in recent years to be well adapted to solving this type of complex flow. In this thesis, a lattice Boltzmann model for the simulation of two-phase immiscible flows is studied. The main objective of the thesis is to develop this promising method further, with a view to enhancing its validity. To achieve this objective, the research is divided into five distinct themes. The first two focus on correcting some of the deficiencies of the original model. The third generalizes the model to support the simulation of N-phase immiscible fluid flows. The fourth is aimed at modifying the model itself, to enable the simulation of immiscible fluid flows in which the density of the phases varies. With the lattice Boltzmann class of models studied here, this density variation has been inadequately modeled, and, after 20 years, the issue still has not been resolved. The fifth, which complements this thesis, is connected with the lattice Boltzmann method, in that it generalizes the theory of 2D and 3D isotropic gradients for a high order of spatial precision. These themes have each been the subject of a scientific article, as listed in the appendix to this thesis, and together they constitute a synthesis that explains the links between the articles, as well as their scientific contributions, and satisfy the main objective of this research. Globally, a number of qualitative and quantitative test cases based on the theory of multiphase fluid flows

  7. The force on an object passing through a magnetic fluid seal

    CERN Document Server

    Morton, G

    2002-01-01

    Forces on solid objects passed through a magnetic liquid plug in a tube are measured. A simple one-dimensional model is developed based on hydrostatic and magnetic pressures. The results demonstrate its potential to be used to separate two fluids while allowing solids to pass from one fluid to the other.

  8. Numerical simulations of natural or mixed convection in vertical channels: comparisons of level-set numerical schemes for the modeling of immiscible incompressible fluid flows

    International Nuclear Information System (INIS)

    Li, R.

    2012-01-01

    The aim of this research dissertation is at studying natural and mixed convections of fluid flows, and to develop and validate numerical schemes for interface tracking in order to treat incompressible and immiscible fluid flows, later. In a first step, an original numerical method, based on Finite Volume discretizations, is developed for modeling low Mach number flows with large temperature gaps. Three physical applications on air flowing through vertical heated parallel plates were investigated. We showed that the optimum spacing corresponding to the peak heat flux transferred from an array of isothermal parallel plates cooled by mixed convection is smaller than those for natural or forced convections when the pressure drop at the outlet keeps constant. We also proved that mixed convection flows resulting from an imposed flow rate may exhibit unexpected physical solutions; alternative model based on prescribed total pressure at inlet and fixed pressure at outlet sections gives more realistic results. For channels heated by heat flux on one wall only, surface radiation tends to suppress the onset of re-circulations at the outlet and to unify the walls temperature. In a second step, the mathematical model coupling the incompressible Navier-Stokes equations and the Level-Set method for interface tracking is derived. Improvements in fluid volume conservation by using high order discretization (ENO-WENO) schemes for the transport equation and variants of the signed distance equation are discussed. (author)

  9. Immiscibility of Fluid Phases at Magmatic-hydrothermal Transition: Formation of Various PGE-sulfide Mineralization for Layered Basic Intrusions

    Science.gov (United States)

    Zhitova, L.; Borisenko, A.; Morgunov, K.; Zhukova, I.

    2007-12-01

    Fluid inclusions in quartz of the Merensky Reef (Bushveld Complex, South Africa) and the Chineisky Pluton (Transbaikal Region, Russia) were studied using cryometry, microthermometry, Raman-spectroscopy, LA ICP- MS, scanning electronic microscopy, gas-chromatography and isotopic methods. This allowed us to document some examples of fluid phase separation resulting in formation of different types of PGE-sulfide mineralization for layered basic intrusions. The results obtained show at least three generations of fluid separated from boiling residual alumosilicate intercumulus liquid of the Merensky Reef. The earliest fluid phase composed of homogenous high-dense methane and nitrogen gas mixture was identified in primary gas and co-existing anomalous fluid inclusions from symplectitic quartz. The next generation, heterophase fluid, composed of brines containing a free low-dense (mostly of carbon dioxide) gas phase, was observed in primary multiphase and coexisting gas-rich inclusions of miarolitic quartz crystals. The latest generation was also a heterophase fluid (low salinity water-salt solution and free low-dense methane gas phase) found in primary water-salt and syngenetic gas inclusions from peripheral zones of miarolitic quartz crystals. For the Chineisky Pluton reduced endocontact magmatogene fluids changed to oxidized low salinity hydrothermal fluids in exocontact zone. This resulted in formation of sulfide-PGE enrichment marginal zones of intrusion. The results obtained give us a possibility to suggest that: 1) Fluid phase separation is a typical feature of magmatogene fluids for layered basic intrusions. 2) Reduced fluids can extract and transport substantial PGE and sulfide concentrations. 3) Oxidation of reduced fluids is one of the most important geochemical barriers causing abundant PGE minerals and sulfides precipitation. This in turn results in both formation of PGE reefs or enriched contact zones of layered basic intrusions. This work was supported by

  10. Fluid inclusion gas chemistry in east Tennessee Mississippi Valley-type districts: Evidence for immiscibility and implications for depositional mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Jones, H.D.; Kesler, S.E. (Univ. of Michigan, Ann Arbor (United States))

    1992-01-01

    Analyses of fluid inclusion gases from Mississippi Valley-type districts in east Tennessee reveal the presence of several distinct aqueous solutions and vapors that were part of the mineralizing process. Inclusion contents were released by crushing 5 to 25 mg mineral samples and by decrepitating individual inclusions; all analyses were obtained by quadrupole mass spectrometry. Most analyzed inclusion fluids consist of H{sub 2}O with significant amounts of CH{sub 4} (0.3 to 2.9 mol%), CO{sub 2} (0.1 to 4.7 mol%), and smaller amounts of C{sub 2}H{sub 6}, C{sub 3}H{sub 8}, H{sub 2}S, SO{sub 2}, N{sub 2}, and Ar. Compositional similarities in the inclusion fluids from three districts imply that mineralization probably formed from fluids that permeated the entire region. Saturation pressures calculated for these fluid compositions range from 300 to 2,200 bars. Burial depths for the host unit have been estimated to be about 2 to 3 km during Devonian time, the age of mineralization indicated by recent isotopic ages. Exsolution of a vapor phase from the mineralizing brines should cause precipitation of carbonate and sulfide minerals, but reaction path modeling indicates that the resulting sparry dolomite:sphalerite ratios would be too high to form an ore-grade deposit. If the vapor phase was from a preexisting sour gas cap that was intercepted by a Zn-rich brine, large amounts of spalerite would precipitate in a fairly small region. Preliminary mass balance calculations suggest that a gas cap of dimensions similar to the individual districts in east Tennessee could have contained enough H{sub 2}S to account for the total amount of sphalerite precipitated.

  11. Energy transfer between a passing vortex ring and a flexible plate in an ideal quiescent fluid

    Energy Technology Data Exchange (ETDEWEB)

    Hu, JiaCheng; Peterson, Sean D., E-mail: peterson@mme.uwaterloo.ca [Department of Mechanical and Mechatronics Engineering, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1 (Canada); Porfiri, Maurizio [Department of Mechanical and Aerospace Engineering, New York University Polytechnic School of Engineering, Brooklyn, New York 11201 (United States)

    2015-09-21

    Recent advancements in highly deformable smart materials have lead to increasing interest in small-scale energy harvesting research for powering low consumption electronic devices. One such recent experimental study by Goushcha et al. explored energy harvesting from a passing vortex ring by a cantilevered smart material plate oriented parallel to and offset from the path of the ring in an otherwise quiescent fluid. The present study focuses on modeling this experimental study using potential flow to facilitate optimization of the energy extraction from the passing ring to raise the energy harvesting potential of the device. The problem is modeled in two-dimensions with the vortex ring represented as a pair of counter-rotating free vortices. Vortex pair parameters are determined to match the convection speed of the ring in the experiments, as well as the imposed pressure loading on the plate. The plate is approximated as a Kirchhoff-Love plate and represented as a finite length vortex sheet in the fluid domain. The analytical model matches experimental measurements, including the tip displacement, the integrated force along the entire plate length as a function of vortex ring position, and the pressure along the plate. The potential flow solution is employed in a parametric study of the governing dimensionless parameters in an effort to guide the selection of plate properties for optimal energy harvesting performance. Results of the study indicate an optimal set of plate properties for a given vortex ring configuration, in which the time-scale of vortex advection matches that of the plate vibration.

  12. A novel method for passing cerebrospinal fluid shunt tubing: a proof of principle study.

    Science.gov (United States)

    Tubbs, R Shane; Goodrich, Dylan; Tubbs, Isaiah; Loukas, Marios; Cohen-Gadol, Aaron A

    2014-12-01

    Few innovations in the method of tunneling shunt tubing for cerebrospinal fluid (CSF) shunt diversion have been made since this treatment of hydrocephalus was first developed. Therefore, this feasibility study was performed with the hope of identifying an improved technique that could potentially carry fewer complications. On 10 cadaver sides and when placed in the supine position, small skin incisions were made at the clavicle and ipsilateral subcostal region, and magnets were used to pass standard shunt tubing between the two incisions. Nickel-plated magnets were less effective in pulling the shunt tubing below the skin compared with ceramic magnets. Of these, magnets with pull strengths of 150-200 lbs were the most effective in dragging the subcutaneous tubing between the two incisions. No obvious damage to the skin from the overlying magnet was seen in any specimen. Few options exist for tunneling distal shunt tubing for CSF shunt procedures. Future patient studies are needed to determine if the technique described herein is superior to current methods, particularly when examining patient groups that are at a greater risk for injury during tunneling shunt catheters.

  13. Ultrathin-skinned asymmetric membranes by immiscible solvents treatment

    Science.gov (United States)

    Friesen, Dwayne T.; Babcock, Walter C.

    1989-01-01

    Improved semipermeable asymmetric fluid separation membranes useful in gas, vapor and liquid separations are disclosed. The membranes are prepared by substantially filling the pores of asymmetric cellulosic semipermeable membranes having a finely porous layer on one side thereof with a water immiscible organic liquid, followed by contacting the finely porous layer with water.

  14. Contribution of experimental fluid mechanics to the design of vertical slot fish passes

    Directory of Open Access Journals (Sweden)

    Wang R.W.

    2010-02-01

    Full Text Available This paper presents the main results of an experimental study of mean and turbulent characteristics of flow in a scale model of a vertical slot fish pass with varying width and slope (from 5% to 15%. Experimental hydraulic modelling was combined with the study of fish behaviour in the model. The discharge coefficient, which significantly affects the design of such facilities, varied from 0.67 to 0.89 and was strongly influenced by the slope. Two distinct flow patterns were observed, depending on the slope and the fish pass width. The point of transition between the two states was determined. Low velocity areas are likely resting zones for fish and particular attention was paid to evaluating these areas. Slope was found to affect both the volume of the low velocity zone, and the value of turbulent kinetic energy in these areas. The statistical characteristics of turbulent kinetic energy in the pools were linked primarily to the maximum velocity in the jet. An analysis of the behaviour of juvenile brown trout (Salmo trutta in the scale model clearly showed that the fish avoided the areas of high velocities in the jet, except at the slot itself where they took advantage of the jet’s non-stationary character. Low-velocity areas were not frequented uniformly by fish, which stayed most frequently in the zone located just downstream from the slot and behind the small side baffle. It is suggested that future studies might investigate lower pool-length to slot-width ratios, which might make it possible to increase the slope significantly and should also examine ways of improving hydraulic conditions for fish by carefully distributing obstacles in pools.

  15. Earthquake wave propagation in immiscibly compressible porous soil

    International Nuclear Information System (INIS)

    Xue, S.; Kurita, S.; Izumi, M.

    1993-01-01

    This paper utilizes the formalism of the theory of immiscible compressible mixtures to formulate the wave propagation equation for the soil where the soil has been assumed as a binary mixture consisting of one solid phase and one fluid phase. The method is developed to solve the one dimensional wave equation by the above theory. The relations between the wave attenuating characteristic value Q and the volume fraction, the relative motion of two phases have been shown. It is concluded that based on such theory we can solve more precisely the soil behaviors while considering the interaction of structure and soil of immiscible mixture. (author)

  16. Stability of a radial immiscible drive

    Energy Technology Data Exchange (ETDEWEB)

    Bataille, J

    1968-11-01

    The stability of the displacement front between 2 immiscible fluids of radial flow between 2 parallel plates (Hele-Shaw model) is studied mathematically by superposing onto the circular displacement front a sinusoidal perturbation. The equations are reduced to dimensionless variables, and it is shown that the stable and unstable domains in a plot: dimensionless viscosity vs. dimensionless time are separated by a polygonal contour, each side of the contour being characterized by the (integer) number of perturbations along the circumference. There is a critical reduced time below which the perturbations are amortized but beyond which they are amplified. Experimental results have been in fair general agreement with theoretical results, the divergence between them being attributable to neglecting capillary phenomena, which may become very important at large radial distances. One test with miscible fluids has shown that even in this case, there is a critical time or an equivalent critical radius.

  17. Morphology development in immiscible polymer blends

    NARCIS (Netherlands)

    Cardinaels, R.M.; Moldenaers, P.; Guo, Qipeng

    This chapter discusses the morphology development of immiscible binary polymer blends. It first describes morphology development in droplet-matrix structures, the dynamics of fibrillar structures and cocontinuous structures. The chapter then considers binary immiscible polymer blends, such systems

  18. Numerical Simulation of Turbulent Fluid Flow and Heat Transfer in a Ribbed Rotating Two-Pass Square Duct

    Directory of Open Access Journals (Sweden)

    Liou Tong-Miin

    2005-01-01

    Full Text Available The local turbulent fluid flow and heat transfer in a rotating two-pass square duct with 19 pairs of in-line 90 ∘ ribs have been investigated computationally. A Reynolds-averaged Navier-Stokes equation (RANS with a two-layer k − ϵ turbulence model was solved. The in-line 90 ∘ ribs were arranged on the leading and trailing walls with rib height-to-hydraulic diameter ratio and pitch-to-height ratio of 0.136 and 10, respectively. The Reynolds number, based on duct hydraulic diameter and bulk mean velocity, was fixed at 1.0 × 10 4 whereas the rotational number varied from 0 to 0.2 . Results are validated with previous measured velocity field and heat transfer coefficient distributions. The validation shows that the effect of rotation on the passage-averaged Nusselt number ratio can be predicted reasonably well; nevertheless, the transverse mean velocity and, in turn, the distribution of regional-averaged Nusselt number ratio are markedly underpredicted in the regions toward which the Coriolis force is directed. Further CFD studies are needed.

  19. Lattice Boltzmann model for simulating immiscible two-phase flows

    International Nuclear Information System (INIS)

    Reis, T; Phillips, T N

    2007-01-01

    The lattice Boltzmann equation is often promoted as a numerical simulation tool that is particularly suitable for predicting the flow of complex fluids. This paper develops a two-dimensional 9-velocity (D2Q9) lattice Boltzmann model for immiscible binary fluids with variable viscosities and density ratio using a single relaxation time for each fluid. In the macroscopic limit, this model is shown to recover the Navier-Stokes equations for two-phase flows. This is achieved by constructing a two-phase component of the collision operator that induces the appropriate surface tension term in the macroscopic equations. A theoretical expression for surface tension is determined. The validity of this analysis is confirmed by comparing numerical and theoretical predictions of surface tension as a function of density. The model is also shown to predict Laplace's law for surface tension and Poiseuille flow of layered immiscible binary fluids. The spinodal decomposition of two fluids of equal density but different viscosity is then studied. At equilibrium, the system comprises one large low viscosity bubble enclosed by the more viscous fluid in agreement with theoretical arguments of Renardy and Joseph (1993 Fundamentals of Two-Fluid Dynamics (New York: Springer)). Two other simulations, namely the non-equilibrium rod rest and the coalescence of two bubbles, are performed to show that this model can be used to simulate two fluids with a large density ratio

  20. Experimental investigation of the characteristics of a laser beam passing through a fluid layer for surface quality in-process measurement

    International Nuclear Information System (INIS)

    Guo, Ruipeng; Tao, Zhengsu

    2010-01-01

    The optical characteristics of a laser beam passing through a fluid parallel layer are examined through a series of experimental tests in this project. The experimental apparatus consists of a bare surface quality measurement system and a fluid-supporting system. In the case of laser beam propagation through the static fluid layer, a modified Beckmann–Kirchhoff scattering model has been developed. Based on this model, the results of the surface quality in-process optical measurement can be amended. By extracting a ratio parameter from the image of the scattered light pattern to estimate surface roughness, the modified model can be verified quantitatively in the experimental system. As far as laser beam propagation through the flowing fluid layer is concerned, the deflection of the laser beam caused by fluid flow is small. The experiments are conducted to investigate the characteristics, and the results show that the resulting measurement error for surface quality optical measurement is in an acceptable range

  1. Effects of transpiration on unsteady MHD flow of an upper convected Maxwell (UCM) fluid passing through a stretching surface in the presence of a first order chemical reaction

    International Nuclear Information System (INIS)

    Mukhopadhyay, Swati; Arif, M. Golam; Pk M Wazed Ali

    2013-01-01

    The aim of this article is to present the effects of transpiration on the unsteady two-dimensional boundary layer flow of non-Newtonian fluid passing through a stretching sheet in the presence of a first order constructive/destructive chemical reaction. The upper-convected Maxwell (UCM) model is used here to characterize the non-Newtonian behavior of the fluid. Using similarity solutions, the governing nonlinear partial differential equations are transformed into ordinary ones and are then solved numerically by the shooting method. The flow fields and mass transfer are significantly influenced by the governing parameters. The fluid velocity initially decreases as the unsteadiness parameter increases and the concentration decreases significantly due to the increase in the unsteadiness. The effect of increasing values of transpiration (suction) and the Maxwell parameter is to suppress the velocity field; however, the concentration is enhanced as transpiration (suction) and the Maxwell parameter increase. Also, it is found that the fluid velocity decreases as the magnetic parameter increases; however, the concentration increases in this case. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  2. The thermal and chemical evolution of hydrothermal vent fluids in shale hosted massive sulphide (SHMS) systems from the MacMillan Pass district (Yukon, Canada)

    Science.gov (United States)

    Magnall, J. M.; Gleeson, S. A.; Blamey, N. J. F.; Paradis, S.; Luo, Y.

    2016-11-01

    At Macmillan Pass (YT, Canada), the hydrothermal vent complexes beneath two shale-hosted massive sulphide (SHMS) deposits (Tom, Jason) are well preserved within Late Devonian strata. These deposits provide a unique opportunity to constrain key geochemical parameters (temperature, salinity, pH, fO2, ΣS) that are critical for metal transport and deposition in SHMS systems, and to evaluate the interaction between hydrothermal fluids and the mudstone host rock. This has been achieved using a combination of detailed petrography, isotopic techniques (δ34S, δ13C and δ18O values), carbonate rare earth element analysis (LA-ICP-MS), fluid inclusion analysis (microthermometry, gas analysis via incremental crush fast scan mass spectrometry), and thermodynamic modelling. Two main paragenetic stages are preserved in both vent complexes: Stage 1 comprises pervasive ankerite alteration of the organic-rich mudstone host rock and crosscutting stockwork ankerite veining (±pyrobitumen, pyrite and quartz) and; Stage 2 consists of main stage massive sulphide (galena-pyrrhotite-pyrite ± chalcopyrite-sphalerite) and siderite (±quartz and barytocalcite) mineralisation. Co-variation of δ18O and δ13C values in ankerite can be described by temperature dependent fractionation and fluid rock interaction. Together with fluid inclusion microthermometry, this provides evidence of a steep thermal gradient (from 300 to ∼100 °C) over approximately 15 m stratigraphic depth, temporally and spatially constrained within the paragenesis of both vent complexes and developed under shallow lithostatic (28), characteristic of diagenetic fluids, are coupled with positive europium anomalies and variable light REE depletion, which are more consistent with chloride complexation in hot (>250 °C) hydrothermal fluids. In this shallow sub-seafloor setting, thermal alteration of organic carbon in the immature, chemically reactive mudstones also had an important role in the evolution of fluid chemistry

  3. A Variational Model for Two-Phase Immiscible Electroosmotic Flow at Solid Surfaces

    KAUST Repository

    Shao, Sihong

    2012-01-01

    We develop a continuum hydrodynamic model for two-phase immiscible flows that involve electroosmotic effect in an electrolyte and moving contact line at solid surfaces. The model is derived through a variational approach based on the Onsager principle of minimum energy dissipation. This approach was first presented in the derivation of a continuum hydrodynamic model for moving contact line in neutral two-phase immiscible flows (Qian, Wang, and Sheng, J. Fluid Mech. 564, 333-360 (2006)). Physically, the electroosmotic effect can be formulated by the Onsager principle as well in the linear response regime. Therefore, the same variational approach is applied here to the derivation of the continuum hydrodynamic model for charged two-phase immiscible flows where one fluid component is an electrolyte exhibiting electroosmotic effect on a charged surface. A phase field is employed to model the diffuse interface between two immiscible fluid components, one being the electrolyte and the other a nonconductive fluid, both allowed to slip at solid surfaces. Our model consists of the incompressible Navier-Stokes equation for momentum transport, the Nernst-Planck equation for ion transport, the Cahn-Hilliard phase-field equation for interface motion, and the Poisson equation for electric potential, along with all the necessary boundary conditions. In particular, all the dynamic boundary conditions at solid surfaces, including the generalized Navier boundary condition for slip, are derived together with the equations of motion in the bulk region. Numerical examples in two-dimensional space, which involve overlapped electric double layer fields, have been presented to demonstrate the validity and applicability of the model, and a few salient features of the two-phase immiscible electroosmotic flows at solid surface. The wall slip in the vicinity of moving contact line and the Smoluchowski slip in the electric double layer are both investigated. © 2012 Global-Science Press.

  4. BHR equations re-derived with immiscible particle effects

    Energy Technology Data Exchange (ETDEWEB)

    Schwarzkopf, John Dennis [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Horwitz, Jeremy A. [Stanford Univ., CA (United States)

    2015-05-01

    Compressible and variable density turbulent flows with dispersed phase effects are found in many applications ranging from combustion to cloud formation. These types of flows are among the most challenging to simulate. While the exact equations governing a system of particles and fluid are known, computational resources limit the scale and detail that can be simulated in this type of problem. Therefore, a common method is to simulate averaged versions of the flow equations, which still capture salient physics and is relatively less computationally expensive. Besnard developed such a model for variable density miscible turbulence, where ensemble-averaging was applied to the flow equations to yield a set of filtered equations. Besnard further derived transport equations for the Reynolds stresses, the turbulent mass flux, and the density-specific volume covariance, to help close the filtered momentum and continuity equations. We re-derive the exact BHR closure equations which include integral terms owing to immiscible effects. Physical interpretations of the additional terms are proposed along with simple models. The goal of this work is to extend the BHR model to allow for the simulation of turbulent flows where an immiscible dispersed phase is non-trivially coupled with the carrier phase.

  5. Comment on the treatment of residual water content in “A consistent set of parametric models for the two-phase flow of immiscible fluids in the subsurface” by L. Luckner et al.

    Science.gov (United States)

    Nimmo, John R.

    1991-01-01

    Luckner et al. [1989] (hereinafter LVN) present a clear summary and generalization of popular formulations used for convenient representation of porous media fluid flow characteristics, including water content (θ) related to suction (h) and hydraulic conductivity (K) related to θ or h. One essential but problematic element in the LVN models is the concept of residual water content (θr; in LVN, θw,r). Most studies using θr determine its value as a fitted parameter and make the assumption that liquid flow processes are negligible at θ values less than θr. While the LVN paper contributes a valuable discussion of the nature of θr, it leaves several problems unresolved, including fundamental difficulties in associating a definite physical condition with θr, practical inadequacies of the models at low θ values, and difficulties in designating a main wetting curve.

  6. Flow of miscible and immiscible hydrocarbons in heterogeneous porous media

    Energy Technology Data Exchange (ETDEWEB)

    Butts, M.B.

    1996-12-31

    A series of large-scale two-dimensional physical model studies has been carried out in order to better understand and predict the multiphase flow of hydrocarbon contaminants and the release of the water-soluble fraction of such contaminants into the groundwater stream. The detailed measurements of the fluid saturations within the bulk hydrocarbon plume as well as the aqueous concentrations recorded downstream should provide a useful data set for testing and improving numerical models of both multiphase flow and transport. Predictions of a numerical model of immiscible multiphase flow developed in the petroleum industry were found to compare favourably with the observed oil plume for the case of an immiscible oil spill. Nevertheless, subtle layering within the experimental flume altered the long-term development of the oil plume in a manner not predicted by the numerical model. A stochastic model for three-dimensional, two-phase incompressible flow in heterogeneous soil and rock formations is developed. Analytical solutions for the resulting stochastic differential equations are derived for asymptotic flows using a perturbation approach. These solutions were used to derive general expressions for the large-scale (effective) properties for large-scale two-phase flow in porous media. An important observation from this analysis is that general large-scale flow in heterogeneous soils cannot be predicted on the basis of simple averages of the soil hydraulic properties alone. The large-scale capillary pressure saturation relation is evaluated for imbibition into a wet soil or rock formation. (EG) 194 refs.

  7. Flow of miscible and immiscible hydrocarbons in heterogeneous porous media

    Energy Technology Data Exchange (ETDEWEB)

    Butts, M B

    1997-12-31

    A series of large-scale two-dimensional physical model studies has been carried out in order to better understand and predict the multiphase flow of hydrocarbon contaminants and the release of the water-soluble fraction of such contaminants into the groundwater stream. The detailed measurements of the fluid saturations within the bulk hydrocarbon plume as well as the aqueous concentrations recorded downstream should provide a useful data set for testing and improving numerical models of both multiphase flow and transport. Predictions of a numerical model of immiscible multiphase flow developed in the petroleum industry were found to compare favourably with the observed oil plume for the case of an immiscible oil spill. Nevertheless, subtle layering within the experimental flume altered the long-term development of the oil plume in a manner not predicted by the numerical model. A stochastic model for three-dimensional, two-phase incompressible flow in heterogeneous soil and rock formations is developed. Analytical solutions for the resulting stochastic differential equations are derived for asymptotic flows using a perturbation approach. These solutions were used to derive general expressions for the large-scale (effective) properties for large-scale two-phase flow in porous media. An important observation from this analysis is that general large-scale flow in heterogeneous soils cannot be predicted on the basis of simple averages of the soil hydraulic properties alone. The large-scale capillary pressure saturation relation is evaluated for imbibition into a wet soil or rock formation. (EG) 194 refs.

  8. Fully developed laminar flow of two immiscible liquids through horizontal pipes: a variational approach

    Energy Technology Data Exchange (ETDEWEB)

    Kurban, Adib Paulo Abdalla [PETROBRAS, Rio de Janeiro (Brazil). Centro de Pesquisas; Bannwart, Antonio Carlos [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Mecanica

    1990-12-31

    The fully developed laminar flow of two immiscible liquids with both different viscosities and densities through a horizontal round pipe is studied. The interface between the fluids as well as their flow fields are determined by the use of a variational principle: the so called viscous dissipation principle: The results foreseen by this paper are in agreement with the physical observation (e.g. Southern and Ballman) that the more viscous fluid is total or partially encapsulated by the less viscous one. (author) 8 refs., 4 figs.

  9. Fully developed laminar flow of two immiscible liquids through horizontal pipes: a variational approach

    Energy Technology Data Exchange (ETDEWEB)

    Kurban, Adib Paulo Abdalla [PETROBRAS, Rio de Janeiro (Brazil). Centro de Pesquisas; Bannwart, Antonio Carlos [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Mecanica

    1991-12-31

    The fully developed laminar flow of two immiscible liquids with both different viscosities and densities through a horizontal round pipe is studied. The interface between the fluids as well as their flow fields are determined by the use of a variational principle: the so called viscous dissipation principle: The results foreseen by this paper are in agreement with the physical observation (e.g. Southern and Ballman) that the more viscous fluid is total or partially encapsulated by the less viscous one. (author) 8 refs., 4 figs.

  10. Interfacial layering and capillary roughness in immiscible liquids.

    Science.gov (United States)

    Geysermans, P; Pontikis, V

    2010-08-21

    The capillary roughness and the atomic density profiles of extended interfaces between immiscible liquids are determined as a function of the interface area by using molecular dynamics and Lennard-Jones (12-6) potentials. We found that with increasing area, the interface roughness diverges logarithmically, thus fitting the theoretical mean-field prediction. In systems small enough for the interfacial roughness not to blur the structural details, atomic density profiles across the fluid interface are layered with correlation length in the range of molecular correlations in liquids. On increasing the system size, the amplitude of the thermally excited position fluctuations of the interface increases, thus causing layering to rapidly vanish, if density profiles are computed without special care. In this work, we present and validate a simple method, operating in the direct space, for extracting from molecular dynamics trajectories the "intrinsic" structure of a fluid interface that is the local density profile of the interface cleaned from capillary wave effects. Estimated values of interfacial properties such as the tension, the intrinsic width, and the lower wavelength limit of position fluctuations are in agreement with results collected from the literature.

  11. Heat transfer between immiscible liquids enhanced by gas bubbling

    International Nuclear Information System (INIS)

    Greene, G.A.; Schwarz, C.E.; Klages, J.; Klein, J.

    1982-08-01

    The phenomena of core-concrete interactions impact upon containment integrity of light water reactors (LWR) following postulated complete meltdown of the core by containment pressurization, production of combustible gases, and basemat penetration. Experiments have been performed with non-reactor materials to investigate one aspect of this problem, heat transfer between overlying immiscible liquids whose interface is disturbed by a transverse non-condensable gas flux emanating from below. Hydrodynamic studies have been performed to test a criterion for onset of entrainment due to bubbling through the interface and subsequent heat transfer studies were performed to assess the effect of bubbling on interfacial heat transfer rates, both with and without bubble induced entrainment. Non-entraining interfacial heat transfer data with mercury-water/oil fluid pairs were observed to be bounded from below within a factor of two to three by the Szekeley surface renewal heat transfer model. However heat transfer data for fluid pairs which are found to entrain (water-oil), believed to be characteristic of molten reactor core-concrete conditions, were measured to be up to two orders of magnitude greater than surface renewal predictions and are calculated by a simple entrainment heat transfer model

  12. Evaporative mass transfer behavior of a complex immiscible liquid.

    Science.gov (United States)

    McColl, Colleen M; Johnson, Gwynn R; Brusseau, Mark L

    2008-09-01

    A series of laboratory experiments was conducted with a multiple-component immiscible liquid, collected from the Picillo Farm Superfund Site in Rhode Island, to examine liquid-vapor mass-transfer behavior. The immiscible liquid, which comprises solvents, oils, pesticides, PCBs, paint sludges, explosives, and other compounds, was characterized using gas chromatography and gas chromatography/mass spectrometry to determine mole fractions of selected constituents. Batch experiments were conducted to evaluate equilibrium phase-partitioning behavior. Two sets of air-stripping column studies were conducted to examine the mass-transfer dynamics of five selected target compounds present in the immiscible-liquid mixture. One set of column experiments was designed to represent a system with free-phase immiscible liquid present; the other was designed to represent a system with a residual phase of immiscible liquid. Initial elution behavior of all target components generally appeared to be ideal for both systems, as the initial vapor-phase concentrations were similar to vapor-phase concentrations measured for the batch experiment and those estimated using Raoult's law (incorporating the immiscible-liquid composition data). Later-stage removal of 1,2-dichlorobenzene appeared to be rate limited for the columns containing free-phase immiscible liquid and no porous medium. Conversely, evaporative mass transfer appeared to be ideal throughout the experiment conducted with immiscible liquid distributed relatively uniformly as a residual phase within a sandy porous medium.

  13. Low gravity containerless processing of immiscible gold rhodium alloys

    Science.gov (United States)

    Andrews, J. Barry

    1986-01-01

    Under normal one-g conditions immiscible alloys segregate extensively during solidification due to sedementation of the more dense of the immiscible liquid phases. However, under low-g conditions it should be possible to form a dispersion of the two immiscible liquids and maintain this dispersed structure during solidification. Immiscible (hypermonotectic) gold-rhodium alloys were processed in the Marshall Space Flight Center 105 meter drop tube in order to investigate the influence of low gravity, containerless solidification on their microstructure. Hypermonotectic alloys composed of 65 atomic % rhodium exhibited a tendency for the gold rich liquid to wet the outer surface of the containerless processed samples. This tendency led to extensive segregation in several cases. However, well dispersed microstructures consisting of 2 to 3 micron diameter rhodium-rich spheres in a gold-rich matrix were produced in 23.4 atomic % rhodium alloys. This is one of the best dispersions obtained in research on immiscible alloy-systems to data.

  14. Modified analytic EAM potentials for the binary immiscible alloy systems

    International Nuclear Information System (INIS)

    Fang, F.; Shu, X.L.; Deng, H.Q.; Hu, W.Y.; Zhu, M.

    2003-01-01

    Modified analytic embedded atom method (MAEAM) type potentials have been constructed for seven binary immiscible alloy systems: Al-Pb, Ag-Ni, Fe-Cu, Ag-Cu, Cu-Ta, Cu-W and Cu-Co. The potentials are fitted to the lattice constant, cohesive energy, unrelaxed monovacancy formation energy and elastic constants for only pure metals which consist the immiscible alloy systems. In order to test the reliability of the constructed MAEAM potentials, formation enthalpies of disordered alloys for those seven binary immiscible alloy systems have been calculated. The calculated results are in general agreement with the experimental data available and those theoretical results calculated by other authors. As only very limited experimental information is available for alloy properties in immiscible alloy systems, the MAEAM is demonstrated to be a reasonable method to construct the interatomic potentials for immiscible alloy systems because only the properties of pure elements are needed in calculation

  15. Passing excellence

    Science.gov (United States)

    Tsoupikova, Daria

    2007-02-01

    This paper describes the research and development of a virtual reality visualization project "Passing excellence" about the world famous architectural ensemble "Kizhi". The Kizhi Pogost is located on an island in Lake Onega in northern Karelia in Russia. It is an authentic museum of an ancient wood building tradition which presents a unique artistic achievement. This ensemble preserves a concentration of masterpieces of the Russian heritage and is included in the List of Most Endangered Sites of the World Monuments Watch protected by World Heritage List of UNESCO. The project strives to create a unique virtual observation of the dynamics of the architectural changes of the museum area beginning from the 15th Century up to the 21st Century. The visualization is being created to restore the original architecture of Kizhi island based on the detailed photographs, architectural and geometric measurements, textural data, video surveys and resources from the Kizhi State Open-Air Museum archives. The project is being developed using Electro, an application development environment for the tiled display high-resolution graphics visualization system and can be shown on the virtual reality systems such as the GeoWall TM and the C-Wall.

  16. Viscous Flow with Large Fluid-Fluid Interface Displacement

    DEFF Research Database (Denmark)

    Rasmussen, Henrik Koblitz; Hassager, Ole; Saasen, Arild

    1998-01-01

    The arbitrary Lagrange-Euler (ALE) kinematic description has been implemented in a 3D transient finite element program to simulate multiple fluid flows with fluid-fluid interface or surface displacements. The description of fluid interfaces includes variable interfacial tension, and the formulation...... is useful in the simulation of low and intermediate Reynolds number viscous flow. The displacement of two immiscible Newtonian fluids in a vertical (concentric and eccentric) annulus and a (vertical and inclined)tube is simulated....

  17. Numerical analysis of natural convection in a double-layer immiscible system

    International Nuclear Information System (INIS)

    Gubaidullin, A.A.; Sehgal, B.R.

    2001-01-01

    In the present paper numerical analysis has been applied to study the natural convection heat transfer in a system composed of two immiscible fluids with uniform internal heat generation in the lower layer or in both layers enclosed in a rectangular or in a semi-circular vessel. The objective of the work is to perform a parametric study to assess the effect of physical properties on the heat transfer characteristics as well as to complement results obtained from experiments by means of CFD simulations for a range of lower Rayleigh number and combine the experimental data and the computational results. (author)

  18. Ensemble distribution for immiscible two-phase flow in porous media.

    Science.gov (United States)

    Savani, Isha; Bedeaux, Dick; Kjelstrup, Signe; Vassvik, Morten; Sinha, Santanu; Hansen, Alex

    2017-02-01

    We construct an ensemble distribution to describe steady immiscible two-phase flow of two incompressible fluids in a porous medium. The system is found to be ergodic. The distribution is used to compute macroscopic flow parameters. In particular, we find an expression for the overall mobility of the system from the ensemble distribution. The entropy production at the scale of the porous medium is shown to give the expected product of the average flow and its driving force, obtained from a black-box description. We test numerically some of the central theoretical results.

  19. Gravity Effect on Two-Phase Immiscible Flows in Communicating Layered Reservoirs

    DEFF Research Database (Denmark)

    Zhang, Xuan; Shapiro, Alexander; Stenby, Erling Halfdan

    2012-01-01

    An upscaling method is developed for two-phase immiscible incompressible flows in layered reservoirs with good communication between the layers. It takes the effect of gravity into consideration. Waterflooding of petroleum reservoirs is used as a basic example for application of this method....... An asymptotic analysis is applied to a system of 2D flow equations for incompressible fluids at high-anisotropy ratios, but low to moderate gravity ratios, which corresponds to the most often found reservoir conditions. The 2D Buckley–Leverett problem is reduced to a system of 1D parabolic equations...

  20. Continuous Solidification of Immiscible Alloys and Microstructure Control

    Science.gov (United States)

    Jiang, Hongxiang; Zhao, Jiuzhou

    2018-05-01

    Immiscible alloys have aroused considerable interest in last few decades due to their excellent physical and mechanical characteristics as well as potential industrial applications. Up to date, plenty of researches have been carried out to investigate the solidification of immiscible alloys on the ground or in space and great progress has been made. It is demonstrated that the continuous solidification technique have great future in the manufacturing of immiscible alloys, it also indicates that the addition of surface active micro-alloying or inoculants for the nucleation of the minority phase droplets and proper application of external fields, e.g., static magnetic field, electric current, microgravity field, etc. may promote the formation of immiscible alloys with an expected microstructure. The objective of this article is to review the research work in this field.

  1. A variational theory of immiscible mixtures with mechanic constraints

    International Nuclear Information System (INIS)

    Carmo, E.G.D. do.

    1982-02-01

    A variational formulation for immiscible mixtures with mechanical restrictions is put forward and the arbitrary parts of the interactional force and stress tensor of the constituents are determined. (Author) [pt

  2. Binary Polymer Brushes of Strongly Immiscible Polymers.

    Science.gov (United States)

    Chu, Elza; Babar, Tashnia; Bruist, Michael F; Sidorenko, Alexander

    2015-06-17

    The phenomenon of microphase separation is an example of self-assembly in soft matter and has been observed in block copolymers (BCPs) and similar materials (i.e., supramolecular assemblies (SMAs) and homo/block copolymer blends (HBCs)). In this study, we use microphase separation to construct responsive polymer brushes that collapse to generate periodic surfaces. This is achieved by a chemical reaction between the minor block (10%, poly(4-vinylpyridine)) of the block copolymer and a substrate. The major block of polystyrene (PS) forms mosaic-like arrays of grafted patches that are 10-20 nm in size. Depending on the nature of the assembly (SMA, HBC, or neat BCP) and annealing method (exposure to vapors of different solvents or heating above the glass transition temperature), a range of "mosaic" brushes with different parameters can be obtained. Successive grafting of a secondary polymer (polyacrylamide, PAAm) results in the fabrication of binary polymer brushes (BPBs). Upon being exposed to specific selective solvents, BPBs may adopt different conformations. The surface tension and adhesion of the binary brush are governed by the polymer occupying the top stratum. The "mosaic" brush approach allows for a combination of strongly immiscible polymers in one brush. This facilitates substantial contrast in the surface properties upon switching, previously only possible for substrates composed of predetermined nanostructures. We also demonstrate a possible application of such PS/PAAm brushes in a tunable bioadhesion-bioadhesive (PS on top) or nonbioadhesive (PAAm on top) surface as revealed by Escherichia coli bacterial seeding.

  3. Flow split characterization of two immiscible phases with different wettability scenarios: a numerical investigation using a coupled Cahn-Hilliard and Navier-Stokes system

    KAUST Repository

    Bao, Kai; Salama, Amgad; Sun, Shuyu

    2017-01-01

    Numerical investigation of flow branching of two-phase immiscible fluids in a Y-shaped, planner channel is conducted by solving the coupled Cahn-Hilliard and Naiver-Stokes system with finite element method. In this system a horizontal channel

  4. A review on rising bubble dynamics in viscosity-stratified fluids

    Indian Academy of Sciences (India)

    Kirti Chandra Sahu

    Multiphase flow; non-Newtonian; immiscible fluids; bubbles; numerical simulations. 1. Introduction. The fluid dynamics of a gas bubble rising due to buoyancy in a surrounding .... Figure 2. Behaviour of a single bubble rising in quiescent liquid.

  5. Process to remove turbidity-causing components from a fluid by micro-filtration - passes the fluid across an asymmetric membrane with inlet pores larger than those of nominal size, and cleans the membrane by backwashing

    DEFF Research Database (Denmark)

    1995-01-01

    turbidity-causing components from beer, wine, fruit juice, milk and blood, and from bacterial and enzyme suspensions. ADVANTAGE-The process greatly reduces the lost production time associated with earlier filtration methods, and beneficial components can pass through the membrane, thereby improving...

  6. Many-Body Potentials For Binary Immiscible liquid Metal Alloys

    International Nuclear Information System (INIS)

    Karaguelle, H.

    2004-01-01

    The modified analytic embedded atom method (MAEAM) type many- body potentials have been constructed for three binary liquid immiscible alloy systems: Al-Pb, Ag-Ni, Ag- Cu. The MAEAM potential functions are fitted to both solid and liquid state properties for only liquid pure metals which consist the immiscible alloy. In order to test the reliability of the constructed MAEAM effective potentials, partial structure factors and pair distribution functions of these binary liquid metal alloys have been calculated using the thermodynamically self-consistent variational modified hypernetted chain (VMHNC) theory of liquids. A good agreement with the available experimental data for structure has

  7. Serious Fun: Using Toys to Demonstrate Fluid Mechanics Principles

    Science.gov (United States)

    Saviz, Camilla M.; Shakerin, Said

    2014-01-01

    Many students have owned or seen fluids toys in which two immiscible fluids within a closed container can be tilted to generate waves. These types of inexpensive and readily available toys are fun to play with, but they are also useful for provoking student learning about fluid properties or complex fluid behavior, including drop formation and…

  8. Interfaces and fluctuations in confined polymeric liquid mixtures: from immiscible to near critical systems

    International Nuclear Information System (INIS)

    Sferrazza, Michele; Carelli, Clara

    2007-01-01

    In this paper the structure of the interface between polymer films is discussed to elucidate fluctuations and confinement effects in fluid polymer mixtures. The neutron reflectivity technique has been employed to investigate the dependence of the structure of the interface on the degree of immiscibility of the polymers over a wide range, as criticality is approached, and to characterize it in terms of intrinsic width, as calculated by mean field theories, and capillary fluctuations. For more immiscible systems, as the degree of incompatibility between the polymers is decreased, the width of the interface increases slowly, and it is independent of the molecular weight of the polymers. Closer to the critical point the dependence on the degree of miscibility becomes stronger and the way in which the interfacial width diverges, as criticality is approached, is related to both chain length and Flory-Huggins interaction parameter (χ). The results have been compared to the predictions of mean field theories. Self-consistent field numerical calculations, with the additional contribution due to capillary waves, provide a good description of the width of the interface between two polymer bulk phases, in particular at higher and intermediate degrees of immiscibility-the product of the Flory-Huggins interaction parameter χ and the number N of monomers of the chain, χN. For more miscible systems a crossover is observed to a region where the square gradient theory in the weak segregation limit better approximates the experimental results. Moreover, the mechanisms by which confinement affects the interface have been investigated. To understand the relative importance of the long ranged van der Waals forces and short ranged 'truncation forces' in modifying thermally excited fluctuations at the polymer/polymer interface, the thickness dependence of the interfacial width has been studied for different degrees of miscibility, approaching criticality. The results show a gradual

  9. Evaluation of miscible and immiscible CO2 injection in one of the Iranian oil fields

    Directory of Open Access Journals (Sweden)

    Aref Hashemi Fath

    2014-09-01

    Full Text Available Carbon dioxide (CO2 flooding is one of the most important methods for enhanced oil recovery (EOR because it not only increases oil recovery efficiency but also causes a reduction of greenhouse gas emissions. It is a very complex system, involving phase behavior that could increase the recovery of oil by means of swelling, evaporation and decreasing viscosity of the oil. In this study, a reservoir modeling approach was used to evaluate immiscible and miscible CO2 flooding in a fractured oil field. To reduce simulation time, we grouped fluid components into 10 pseudo-components. The 3-parameter, Peng–Robinson Equation of State (EOS was used to match PVT experimental data by using the PVTi software. A one-dimensional slim-tube model was defined using ECLIPSE 300 software to determine the minimum miscibility pressure (MMP for injection of CO2. We used FloGrid software for making a reservoir static model and the reservoir model was calibrated using manual and assisted history matching methods. Then various scenarios of natural depletion, immiscible and miscible CO2 injection have been simulated by ECLIPSE 300 software and then the simulation results of scenarios have been compared. Investigation of simulation results shows that the oil recovery factor in miscible CO2 injection scenario is more than other methods.

  10. Experimental study on immiscible jet breakup using refractive index matched oil-water pair

    Science.gov (United States)

    Xue, Xinzhi; Katz, Joseph

    2016-11-01

    A subsea oil well blowout creates an immiscible crude oil jet. This jet fragments shortly after injection, resulting in generation of a droplet cloud. Detailed understanding of the processes involved is crucial for modeling the fragmentation and for predicting the droplet size distribution. High density of opaque droplets near nozzle limits our ability to visualize and quantify the breakup process. To overcome this challenge, two immiscible fluids: silicone oil and sugar water with the same index of refraction (1.4015) are used as surrogates for crude oil and seawater, respectively. Their ratios of kinematic viscosity (5.64), density (0.83) and interfacial tension are closely matched with those of crude oil and seawater. Distribution of the oil phase is visualized by fluorescent tagging. Both phases are also seeded with particles for simultaneous PIV measurements. The measurements are performed within atomization range of Ohnesorge and Reynolds numbers. Index matching facilitates undistorted view of the phase distribution in illuminated section. Ongoing tests show that the jet surface initially rolls up into Kelvin-Helmholtz rings, followed by development of dispersed phase ligaments further downstream, which then break into droplets. Some of these droplets are re-entrained into the high momentum core, resulting in secondary breakup. As the oil layer and ligaments evolve, they often entrain water, resulting in generation of multiple secondary water droplets encapsulated within the oil droplets. This research is made possible by a Grant from Gulf of Mexico Research Initiative.

  11. Measurement of interfacial tension of immiscible liquid pairs in microgravity

    Science.gov (United States)

    Weinberg, Michael C.; Neilson, George F.; Baertlein, Carl; Subramanian, R. Shankar; Trinh, Eugene H.

    1994-01-01

    A discussion is given of a containerless microgravity experiment aimed at measuring the interfacial tension of immiscible liquid pairs using a compound drop rotation method. The reasons for the failure to execute such experiments in microgravity are described. Also, the results of post-flight analyses used to confirm our arguments are presented.

  12. Facile and rapid DNA extraction and purification from food matrices using IFAST (immiscible filtration assisted by surface tension).

    Science.gov (United States)

    Strotman, Lindsay N; Lin, Guangyun; Berry, Scott M; Johnson, Eric A; Beebe, David J

    2012-09-07

    Extraction and purification of DNA is a prerequisite to detection and analytical techniques. While DNA sample preparation methods have improved over the last few decades, current methods are still time consuming and labor intensive. Here we demonstrate a technology termed IFAST (Immiscible Filtration Assisted by Surface Tension), that relies on immiscible phase filtration to reduce the time and effort required to purify DNA. IFAST replaces the multiple wash and centrifugation steps required by traditional DNA sample preparation methods with a single step. To operate, DNA from lysed cells is bound to paramagnetic particles (PMPs) and drawn through an immiscible fluid phase barrier (i.e. oil) by an external handheld magnet. Purified DNA is then eluted from the PMPs. Here, detection of Clostridium botulinum type A (BoNT/A) in food matrices (milk, orange juice), a bioterrorism concern, was used as a model system to establish IFAST's utility in detection assays. Data validated that the DNA purified by IFAST was functional as a qPCR template to amplify the bont/A gene. The sensitivity limit of IFAST was comparable to the commercially available Invitrogen ChargeSwitch® method. Notably, pathogen detection via IFAST required only 8.5 μL of sample and was accomplished in five-fold less time. The simplicity, rapidity and portability of IFAST offer significant advantages when compared to existing DNA sample preparation methods.

  13. Upscaling of Two-Phase Immiscible Flows in Communicating Stratified Reservoirs

    DEFF Research Database (Denmark)

    Zhang, Xuan; Shapiro, Alexander; Stenby, Erling Halfdan

    2011-01-01

    A semi-analytical method for upscaling two-phase immiscible flows in heterogeneous porous media is described. This method is developed for stratified reservoirs with perfect communication between layers (the case of vertical equilibrium), in a viscous dominant regime, where the effects of capillary...... forces and gravity may be neglected. The method is discussed on the example of its basic application: waterflooding in petroleum reservoirs. We apply asymptotic analysis to a system of two-dimensional (2D) mass conservation equations for incompressible fluids. For high anisotropy ratios, the pressure...... and piston-like displacement, and it presumes non-zero exchange between layers. The method generalizes also the study of Yortsos (Transp Porous Media 18:107–129, 1995), taking into account in a more consistent way the interactions between the layers....

  14. Predicting liquid immiscibility in multicomponent nuclear waste glasses

    International Nuclear Information System (INIS)

    Peeler, D.K.; Hrma, P.R.

    1994-01-01

    Taylor's model for predicting amorphous phase separation in complex, multicomponent systems has been applied to high-level (simulated) radioactive waste glasses at the U.S. Department of Energy's Hanford site. Taylor's model is primarily based on additions of modifying cations to a Na 2 O-B 2 O 3 -SiO 2 (NBS) submixture of the multicomponent glass. The position of the submixture relative to the immiscibility dome defines the development probability of amorphous phase separation. Although prediction of amorphous phase separation in Hanford glasses (via experimental SEM/TEM analysis) is the primary thrust of this work; reported durability data is also provides limited insight into the composition/durability relationship. Using a modified model similar to Taylor's, the results indicate that immiscibility may be predicted for multicomponent waste glasses by the addition of Li 2 O to the open-quotes alkaliclose quotes corner of the NBS submixture

  15. Development of injection moulded, ultrasonically welded immiscible phase filtration devices

    DEFF Research Database (Denmark)

    Kistrup, Kasper

    for ultrasonic welding, suitable for microfluidic systems. A methodology has been established where energy directors can be quickly added to existing mould inserts, using laser micromachining. The produced device was performance tested by isolating methicillin-resistant Staphylococcus aureus from bovine whole....... The device appliesmagnetic bead-based solid-phase extraction for nucleic acid extraction from biological samples, using the immiscible phase filtration (IPF) approach. Device development has employed injection moulding for part fabrication and ultrasonic welding for bonding. Rapid prototyping...

  16. Characteristic impedance of a microchannel with two immiscible microfluids

    Science.gov (United States)

    Jaramillo Raquejo, Daniela

    2014-05-01

    Consider the case of a microcapillary of radius R with two microfluidic immiscible. The micro-capillary region 0 expressed in terms of Bessel functions. Similarly, the characteristic impedance of the microcapillary is expressed by a complex formula Bessel functions. Obtain the analytical results are important for designing engineering microdevices with applications in pharmaceutical, food engineering, nanotechnology and biotechnology in general in particular. For future research it is interesting to consider the case of boundary conditions with memory effects.

  17. Lattice Boltzmann simulation of immiscible displacement in the cavity with different channel configurations

    Science.gov (United States)

    Lou, Qin; Zang, Chenqiang; Yang, Mo; Xu, Hongtao

    In this work, the immiscible displacement in a cavity with different channel configurations is studied using an improved pseudo-potential lattice Boltzmann equation (LBE) model. This model overcomes the drawback of the dependence of the fluid properties on the grid size, which exists in the original pseudo-potential LBE model. The approach is first validated by the Laplace law. Then, it is employed to study the immiscible displacement process. The influences of different factors, such as the surface wettability, the distance between the gas cavity and liquid cavity and the surface roughness of the channel are investigated. Numerical results show that the displacement efficiency increases and the displacement time decreases with the increase of the surface contact angle. On the other hand, the displacement efficiency increases with increasing distance between the gas cavity and the liquid cavity at first and finally reaches a constant value. As for the surface roughness, two structures (a semicircular cavity and a semicircular bulge) are studied. The comprehensive results show that although the displacement processes for both the structures depend on the surface wettability, they present quite different behaviors. Specially, for the roughness structure constituted by the semicircular cavity, the displacement efficiency decreases and displacement time increases evidently with the size of the semicircular cavity for the small contact angle. The trend slows down as the increase of the contact angle. Once the contact angle exceeds a certain value, the size of the semicircular cavity almost has no influence on the displacement process. While for the roughness structure of a semicircular bulge, the displacement efficiency increases with the size of bulge first and then it decreases for the small contact angle. The displacement efficiency increases first and finally reaches a constant for the large contact angle. The results also show that the displacement time has an

  18. A novel numerical approach for the solution of the problem of two-phase, immiscible flow in porous media: Application to LNAPL and DNAPL

    KAUST Repository

    Salama, Amgad

    2012-06-17

    The flow of two immiscible fluids in porous media is ubiquitous particularly in petroleum exploration and extraction. The displacement of one fluid by another immiscible with it represents a very important aspect in what is called enhanced oil recovery. Another example is related to the long-term sequestration of carbon dioxide, CO2 , in deep geologic formations. In this technique, supercritical CO2 is introduced into deep saline aquifer where it displaces the hosting fluid. Furthermore, very important classes of contaminants that are very slightly soluble in water and represent a huge concern if they get introduced to groundwater could basically be assumed immiscible. These are called light non-aqueous phase liquids (LNAPL) and dense non-aqueous phase liquids (DNAPL). All these applications necessitate that efficient algorithms be developed for the numerical solution of these problems. In this work we introduce the use of shifting matrices to numerically solving the problem of two-phase immiscible flows in the subsurface. We implement the cell-center finite difference method which discretizes the governing set of partial differential equations in conservative manner. Unlike traditional solution methodologies, which are based on performing the discretization on a generic cell and solve for all the cells within a loop, in this technique, the cell center information for all the cells are obtained all at once without loops using matrix oriented operations. This technique is significantly faster than the traditional looping algorithms, particularly for larger systems when coding using languages that require repeating interpretation each time a loop is called like Mat Lab, Python and the like. We apply this technique to the transport of LNAPL and DNAPL into a rectangular domain.

  19. TPG bus passes

    CERN Multimedia

    Staff Association

    2013-01-01

    The CERN Staff Association will stop selling TPG bus passes. All active and retired members of the CERN personnel will be able to purchase Unireso bus passes from the CERN Hostel - Building 39 (Meyrin site) from 1st February 2013. For more information: https://cds.cern.ch/journal/CERNBulletin/2013/04/Announcements/1505279?ln=en

  20. Pore-scale observation and 3D simulation of wettability effects on supercritical CO2 - brine immiscible displacement in drainage

    Science.gov (United States)

    Hu, R.; Wan, J.; Chen, Y.

    2016-12-01

    Wettability is a factor controlling the fluid-fluid displacement pattern in porous media and significantly affects the flow and transport of supercritical (sc) CO2 in geologic carbon sequestration. Using a high-pressure micromodel-microscopy system, we performed drainage experiments of scCO2 invasion into brine-saturated water-wet and intermediate-wet micromodels; we visualized the scCO2 invasion morphology at pore-scale under reservoir conditions. We also performed pore-scale numerical simulations of the Navier-Stokes equations to obtain 3D details of fluid-fluid displacement processes. Simulation results are qualitatively consistent with the experiments, showing wider scCO2 fingering, higher percentage of scCO2 and more compact displacement pattern in intermediate-wet micromodel. Through quantitative analysis based on pore-scale simulation, we found that the reduced wettability reduces the displacement front velocity, promotes the pore-filling events in the longitudinal direction, delays the breakthrough time of invading fluid, and then increases the displacement efficiency. Simulated results also show that the fluid-fluid interface area follows a unified power-law relation with scCO2 saturation, and show smaller interface area in intermediate-wet case which suppresses the mass transfer between the phases. These pore-scale results provide insights for the wettability effects on CO2 - brine immiscible displacement in geologic carbon sequestration.

  1. Regularized lattice Boltzmann model for immiscible two-phase flows with power-law rheology

    Science.gov (United States)

    Ba, Yan; Wang, Ningning; Liu, Haihu; Li, Qiang; He, Guoqiang

    2018-03-01

    In this work, a regularized lattice Boltzmann color-gradient model is developed for the simulation of immiscible two-phase flows with power-law rheology. This model is as simple as the Bhatnagar-Gross-Krook (BGK) color-gradient model except that an additional regularization step is introduced prior to the collision step. In the regularization step, the pseudo-inverse method is adopted as an alternative solution for the nonequilibrium part of the total distribution function, and it can be easily extended to other discrete velocity models no matter whether a forcing term is considered or not. The obtained expressions for the nonequilibrium part are merely related to macroscopic variables and velocity gradients that can be evaluated locally. Several numerical examples, including the single-phase and two-phase layered power-law fluid flows between two parallel plates, and the droplet deformation and breakup in a simple shear flow, are conducted to test the capability and accuracy of the proposed color-gradient model. Results show that the present model is more stable and accurate than the BGK color-gradient model for power-law fluids with a wide range of power-law indices. Compared to its multiple-relaxation-time counterpart, the present model can increase the computing efficiency by around 15%, while keeping the same accuracy and stability. Also, the present model is found to be capable of reasonably predicting the critical capillary number of droplet breakup.

  2. Electric-double-layer potential distribution in multiple-layer immiscible electrolytes

    NARCIS (Netherlands)

    Das, S.; Hardt, Steffen

    2011-01-01

    In this Brief Report, we calculate the electric-double-layer (EDL) electrostatic potential in a system of several layers of immiscible electrolytes. Verwey-Niessen theory predicts that at the interface between two immiscible electrolytes back-to-back EDLs are formed. The present analysis extends

  3. Passing and Catching in Rugby.

    Science.gov (United States)

    Namudu, Mike M.

    This booklet contains the fundamentals for rugby at the primary school level. It deals primarily with passing and catching the ball. It contains instructions on (1) holding the ball for passing, (2) passing the ball to the left--standing, (3) passing the ball to the left--running, (4) making a switch pass, (5) the scrum half's normal pass, (6) the…

  4. On the efficiency of a fluid-fluid centrifugal separation

    International Nuclear Information System (INIS)

    Apazidis, N.

    1984-05-01

    Efficiency of a separation process of two immiscible incompressible fluids of different densities occuring under the influence of a combined centrifugal and gravitational force field is investigated. The analysis is based on the set of equations for a rotating two-phase flow of a mixture as presented by Greenspan (1983). The geometry of the separation process is considered and the total flow of the separated phases evaluated. (author)

  5. Predicting liquid immiscibility in multicomponent nuclear waste glasses

    International Nuclear Information System (INIS)

    Peeler, D.K.; Hrma, P.R.

    1994-04-01

    Taylor's model for predicting amorphous phase separation in complex, multicomponent systems has been applied to high-level (simulated) radioactive waste glasses at the US Department of Energy's Hanford site. Taylor's model is primarily based on additions of modifying cations to a Na 2 O-B 2 O 3 -SiO 2 (NBS) submixture of the multicomponent glass. The position of the submixture relative to the miscibility dome defines the development probability of amorphous phase separation. Although prediction of amorphous phase separation in Hanford glasses (via experimental SEM/TEM analysis) is the primary thrust of this work; reported durability data is also provides limited insight into the composition/durability relationship. Using a modified model similar to Taylor's, the results indicate that immiscibility may be predicted for multicomponent waste glasses by the addition of Li 2 O to the ''alkali'' corner of the NBS submixture

  6. Immiscible three-dimensional fingering in porous media: A weakly nonlinear analysis

    Science.gov (United States)

    Brandão, Rodolfo; Dias, Eduardo O.; Miranda, José A.

    2018-03-01

    We present a weakly nonlinear theory for the development of fingering instabilities that arise at the interface between two immiscible viscous fluids flowing radially outward in a uniform three-dimensional (3D) porous medium. By employing a perturbative second-order mode-coupling scheme, we investigate the linear stability of the system as well as the emergence of intrinsically nonlinear finger branching events in this 3D environment. At the linear stage, we find several differences between the 3D radial fingering and its 2D counterpart (usual Saffman-Taylor flow in radial Hele-Shaw cells). These include the algebraic growth of disturbances and the existence of regions of absolute stability for finite values of viscosity contrast and capillary number in the 3D system. On the nonlinear level, our main focus is to get analytical insight into the physical mechanism resulting in the occurrence of finger tip-splitting phenomena. In this context, we show that the underlying mechanism leading to 3D tip splitting relies on the coupling between the fundamental interface modes and their first harmonics. However, we find that in three dimensions, in contrast to the usual 2D fingering structures normally encountered in radial Hele-Shaw flows, tip splitting into three branches can also be observed.

  7. Displacement of one Newtonian fluid by another: density effects in axial annular flow

    DEFF Research Database (Denmark)

    Szabo, Peter; Hassager, Ole

    1997-01-01

    The arbitrary Lagrange-Euler (ALE) finite elementtechnique is used to simulate 3D displacement oftwo immiscible Newtonian fluids in vertical annular wells. For equally viscous fluids the effect of distinct fluid densities is investigated in the region of low to intermediate Reynolds numbers......, the efficiency of the displacement is analysed for various flow situations....

  8. Specific interface area in a thin layer system of two immiscible liquids with vapour generation at the contact interface

    Science.gov (United States)

    Pimenova, Anastasiya V.; Gazdaliev, Ilias M.; Goldobin, Denis S.

    2017-06-01

    For well-stirred multiphase fluid systems the mean interface area per unit volume, or “specific interface area” SV, is a significant characteristic of the system state. In particular, it is important for the dynamics of systems of immiscible liquids experiencing interfacial boiling. We estimate the value of parameter SV as a function of the heat influx {\\dot{Q}}V to the system or the average system overheat above the interfacial boiling point. The derived results can be reformulated for the case of an endothermic chemical reaction between two liquid reagents with the gaseous form of one of the reaction products. The final results are restricted to the case of thin layers, where the potential gravitational energy of bubbles leaving the contact interface is small compared to their surface tension energy.

  9. A Variational Model for Two-Phase Immiscible Electroosmotic Flow at Solid Surfaces

    KAUST Repository

    Shao, Sihong; Qian, Tiezheng

    2012-01-01

    We develop a continuum hydrodynamic model for two-phase immiscible flows that involve electroosmotic effect in an electrolyte and moving contact line at solid surfaces. The model is derived through a variational approach based on the Onsager

  10. Laboratory and numerical investigations of kinetic interface sensitive tracers transport for immiscible two-phase flow porous media systems

    Science.gov (United States)

    Tatomir, Alexandru Bogdan A. C.; Sauter, Martin

    2017-04-01

    A number of theoretical approaches estimating the interfacial area between two fluid phases are available (Schaffer et al.,2013). Kinetic interface sensitive (KIS) tracers are used to describe the evolution of fluid-fluid interfaces advancing in two phase porous media systems (Tatomir et al., 2015). Initially developed to offer answers about the supercritical (sc)CO2 plume movement and the efficiency of trapping in geological carbon storage reservoirs, KIS tracers are tested in dynamic controlled laboratory conditions. N-octane and water, analogue to a scCO2 - brine system, are used. The KIS tracer is dissolved in n-octane, which is injected as the non-wetting phase in a fully water saturated porous media column. The porous system is made up of spherical glass beads with sizes of 100-250 μm. Subsequently, the KIS tracer follows a hydrolysis reaction over the n-octane - water interface resulting in an acid and phenol which are both water soluble. The fluid-fluid interfacial area is described numerically with the help of constitutive-relationships derived from the Brooks-Corey model. The specific interfacial area is determined numerically from pore scale calculations, or from different literature sources making use of pore network model calculations (Joekar-Niasar et al., 2008). This research describes the design of the laboratory setup and compares the break-through curves obtained with the forward model and in the laboratory experiment. Furthermore, first results are shown in the attempt to validate the immiscible two phase flow reactive transport numerical model with dynamic laboratory column experiments. Keywords: Fluid-fluid interfacial area, KIS tracers, model validation, CCS, geological storage of CO2

  11. Satellite formation during bubble transition through an interface between immiscible liquids

    KAUST Repository

    Li, Erqiang

    2014-03-12

    When a bubble rises to an interface between two immiscible liquids, it can pass through the interface, if this is energetically favourable, i.e. The bubble preferring the side of the interface with the lower air-liquid surface tension. Once the intermediate film between the bubble and the interface has drained sufficiently, the bubble makes contact with the interface, forming a triple-line and producing strong capillary waves which travel around the bubble and can pinch off a satellite on the opposite side, akin to the dynamics in the coalescence cascade. We identify the critical Ohnesorge numbers where such satellites are produced and characterize their sizes. The total transition time scales with the bubble size and differential surface tension, while the satellite pinch-off time scales with the capillary-inertial time of the pool liquid, which originally surrounds the bubble. We also use high-speed video imaging to study the motion of the neck of the contact. For low viscosity we show that it grows in time with a power-law exponent between 0.44 and 0.50, with a prefactor modified by the net sum of the three interfacial tensions. Increasing the viscosity of the receiving liquid drop drastically slows down the motion of the triple-line, when the Ohnesorge number exceeds ${\\\\sim }$0.08. This differs qualitatively from the coalescence of two miscible drops of different viscosities, where the lower viscosity sets the coalescence speed. We thereby propose a strong resistance from the triple-line. © 2014 Cambridge University Press.

  12. RBS/NRA/channeling analysis of implanted immiscible species

    International Nuclear Information System (INIS)

    Naramoto, H.; Yamamoto, S.; Narumi, K.

    2000-01-01

    Ion implantation of immiscible elements was performed to prepare supersaturated substance for further heat treatment. 63 Cu ion implantation was made at low temperature into Nb(1 0 0), (1 1 0) and (1 1 1) single crystal films on sapphire, and the induced lattice damage and the lattice location of implanted Cu atoms were analyzed by 2.7 MeV 4 He + RBS/channeling. The coherent segregation of 63 Cu atoms with specific crystallographic orientations was found in the near surface region (Cu(1 0 0)/Nb(1 0 0), Cu(1 1 1)/Nb(1 1 0) and Cu(1 1 0)/Nb(1 1 1)). The same kind of study was also made in Ir(1 0 0)/MgO(1 0 0) implanted with 50 keV 12 C + ions. In addition to 2 MeV 4 He + RBS/channeling, 1.22 MeV d + RBS/NRA/channeling was employed to detect implanted 12 C atoms. The results suggest that 12 C atoms are aligned along Ir direction at least by low temperature implantation followed by thermal annealing

  13. Dissociation of dilute immiscible copper alloy thin films

    International Nuclear Information System (INIS)

    Barmak, K.; Lucadamo, G. A.; Cabral, C. Jr.; Lavoie, C.; Harper, J. M. E.

    2000-01-01

    The dissociation behavior of dilute, immiscible Cu-alloy thin films is found to fall into three broad categories that correlate most closely with the form of the Cu-rich end of the binary alloy phase diagrams. Available thermodynamic and tracer diffusion data shed further light on alloy behavior. Eight alloying elements were selected for these studies, with five elements from groups 5 and 6, two from group 8, and one from group 11 of the periodic table. They are respectively V, Nb, Ta, Cr, Mo, Fe, Ru, and Ag. The progress of precipitation in approximately 500-nm-thick alloy films, containing 2.5-3.8 at. % solute, was followed with in situ resistance and stress measurements as well as with in situ synchrotron x-ray diffraction. In addition, texture analysis and transmission electron microscopy were used to investigate the evolution of microstructure and texture of Cu(Ta) and Cu(Ag). For all eight alloys, dissociation occurred upon heating, with the rejection of solute and evolution of microstructure often occurring in multiple steps that range over several hundred degrees between approximately 100 and 900 degree sign C. However, in most cases, substantial reductions in resistivity of the films took place below 400 degree sign C, at temperatures of interest to copper metallization schemes for silicon chip technology. (c) 2000 American Institute of Physics

  14. Introduction: Mirrors of Passing

    DEFF Research Database (Denmark)

    Seebach, Sophie Hooge; Willerslev, Rane

    How is death, time, and materiality interconnected? How to approach an understanding of the world of the dead? In this introduction, we seek to understand how the experience of material decay, of the death of those around us, makes us aware of the passing of time. Through the literary lens of Neil...... Gaiman’s The Graveyard Book, we explore how the world of the dead and the world of the living can intersect; how time and materiality shifts and changes depending on who experiences it. These revelations, based on fiction, provide a mirror through which the reader can experience the varied chapters...

  15. Passing the baton

    CERN Multimedia

    2011-01-01

    It was not only in South Korea that batons were being passed last week. While the cream of the world’s athletes were competing in the World Athletics Championships, the cream of the world’s accelerator scientists were on their way to San Sebastian in Spain for the International Particle Accelerator Conference.  One of them was carrying a rather special baton for a handover of a different kind.   When Fermilab’s Vladimir Shiltsev handed the high-energy frontier baton to CERN’s Mike Lamont on Tuesday, it marked the end of an era: a time to look back on the phenomenal contribution the Tevatron has made to particle physics over its 25-year operational lifetime, and the great contribution Fermilab has made over that period to global collaboration in particle physics. There’s always a lot of emotion involved in passing the baton. In athletics, it’s the triumph of wining or the heartbreak of losing. But for this special baton, the...

  16. TRT Barrel milestones passed

    CERN Multimedia

    Ogren, H

    2004-01-01

    The barrel TRT detector passed three significant milestones this spring. The Barrel Support Structure (BSS) was completed and moved to the SR-1 building on February 24th. On March 12th the first module passed the quality assurance testing in Building 154 and was transported to the assembly site in the SR-1 building for barrel assembly. Then on April 21st the final production module that had been scanned at Hampton University was shipped to CERN. TRT Barrel Module Production The production of the full complement of barrel modules (96 plus 9 total spares) is now complete. This has been a five-year effort by Duke University, Hampton University, and Indiana University. Actual construction of the modules in the United States was completed in the first part of 2004. The production crews at each of the sites in the United States have now completed their missions. They are shown in the following pictures. Duke University: Production crew with the final completed module. Indiana University: Module producti...

  17. Study of void fraction and mixing of immiscible liquids in a pool configuration by an upward gas flow

    International Nuclear Information System (INIS)

    Casas, J.C.; Corradini, M.L.

    1992-01-01

    In this paper, investigations are performed to study the mixing between immiscible liquids in a pool configuration due to an upward gas flow. A water-R113 system is sued in the bubbly/churn-turbulent regimes to determine the effects of the unagitated pool depth on layer mixing. The superficial gas velocity at which full mixing is attained is observed to increase with the pool depth, although it is concluded that this is a weak dependency. Mixing in the churn-turbulent regime is studied with Wood's metal-water and Wood's metal-silicone fluid (100 cS) as pairs of fluids. Additional past mixing data from six other fluids are also included in the data base. A criterion is proposed to determine if two liquids will entrain in bubbly or churn-turbulent flow. Correlations are derived that, for a set of given conditions, allow prediction of the mixing state (mixed or segregated) of a system. Because of the indirect method of measuring the mixed layer thickness, pool void fraction experiments are also performed. For the case of water and R113, the effect of unagitated pool depth on the void fraction is studied

  18. Riemann-problem and level-set approaches for two-fluid flow computations I. Linearized Godunov scheme

    NARCIS (Netherlands)

    B. Koren (Barry); M.R. Lewis; E.H. van Brummelen (Harald); B. van Leer

    2001-01-01

    textabstractA finite-volume method is presented for the computation of compressible flows of two immiscible fluids at very different densities. The novel ingredient in the method is a two-fluid linearized Godunov scheme, allowing for flux computations in case of different fluids (e.g., water and

  19. Deuterium pass through target

    International Nuclear Information System (INIS)

    Alger, D.L.

    1975-01-01

    A neutron emitting target is described for use in neutron generating apparatus including a deuteron source and an accelerator vacuum chamber. The target consists of a tritium-containing target layer, a deuteron accumulation layer, and a target support containing passages providing communication between the accumulation layer and portions of the surface of the support exposed to the accelerator vacuum chamber. With this arrangement, deuterons passing through the target layer and implanting in and diffusing through the accumulation layer, diffuse into the communicating passages and are returned to the accelerator vacuum chamber. The invention allows the continuous removal of deuterons from the target in conventional water cooled neutron generating apparatus. Preferably, the target is provided with thin barrier layers to prevent undesirable tritium diffusion out of the target layer, as well as deuteron diffusion into the target layer

  20. Numerical Study of the Influence of Cavity on Immiscible Liquid Transport in Varied-Wettability Fractures

    Directory of Open Access Journals (Sweden)

    Zhi Dou

    2015-01-01

    Full Text Available Field evidence indicates that cavities often occur in fractured rocks, especially in a Karst region. Once the immiscible liquid flows into the cavity, the cavity has the immiscible liquid entrapped and results in a low recovery ratio. In this paper, the immiscible liquid transport in cavity-fractures was simulated by Lattice Boltzmann Method (LBM. The interfacial and surface tensions were incorporated by Multicomponent Shan-Chen (MCSC model. Three various fracture positions were generated to investigate the influence on the irreducible nonwetting phase saturation and displacement time. The influences of fracture aperture and wettability on the immiscible liquid transport were discussed and analyzed. It was found that the cavity resulted in a long displacement time. Increasing the fracture aperture with the corresponding decrease in displacement pressure led to the long displacement time. This consequently decreased the irreducible nonwetting phase saturation. The fracture positions had a significant effect on the displacement time and irreducible saturation. The distribution of the irreducible nonwetting phase was strongly dependent on wettability and fracture position. Furthermore, this study demonstrated that the LBM was very effective in simulating the immiscible two-phase flow in the cavity-fracture.

  1. Structure-Preserving Methods for the Navier-Stokes-Cahn-Hilliard System to Model Immiscible Fluids

    KAUST Repository

    Sarmiento, Adel

    2017-01-01

    in the energy analysis, allow us to validate our approach. Additionally, we present the development of an unconditionally energy-stable generalized-alpha method for the Swift-Hohenberg model that offers control over the numerical dissipation. A pattern formation

  2. A New Appraoch to Modeling Immiscible Two-phase Flow in Porous Media

    DEFF Research Database (Denmark)

    Yuan, Hao; Shapiro, Alexander; Stenby, Erling Halfdan

    In this work we present a systematic literature review regarding the macroscopic approaches to modeling immiscible two-phase flow in porous media, the formulation process of the incorporate PDE based on Film Model(viscous coupling), the calculation of saturation profile around the transition zone...... to modeling immiscible two-phase flow in porous media. The suggested approach to immiscible two-phase flow in porous media describes the dispersed mesoscopic fluids’ interfaces which are highly influenced by the injected interfacial energy and the local interfacial energy capacity. It reveals a new...... possibility of modeling two-phase flow through energy balance. The saturation profile generated through the suggested approach is different from those through other approaches....

  3. Immiscible iron- and silica-rich melt in basalt petrogenesis documented in the Skaergaard intrusion

    DEFF Research Database (Denmark)

    Jakobsen, Jakob Kløve; Veksler, Ilya; Tegner, Christian

    2005-01-01

    colored type contains 30.9 6 4.2 wt% FeOt and 40.7 6 3.6 wt% SiO2, whereas the light colored type contains 8.6 6 5.9 wt% FeOt and 65.6 6 7.3 wt% SiO2. Similar light colored melt inclusions in olivine and fine grained dark and light colored interstitial pockets also give evidence of crystallization from......Silicate liquid immiscibility in basalt petrogenesis is a contentious issue. Immiscible iron and silica-rich liquids were reported in melt inclusions of lunar basalt and in groundmass glasses of terrestrial volcanics. In fully crystallized plutonic rocks, however, silicate liquid immiscibility has...

  4. Growth kinetics in multicomponent fluids

    International Nuclear Information System (INIS)

    Chen, S.; Lookman, T.

    1995-01-01

    The hydrodynamic effects on the late-stage kinetics in spinodal decomposition of multicomponent fluids are examined using a lattice Boltzmann scheme with stochastic fluctuations in the fluid and at the interface. In two dimensions, the three- and four-component immiscible fluid mixture (with a 1024 2 lattice) behaves like an off-critical binary fluid with an estimated domain growth of t 0.4 +/= 0.03 rather than t 1/3 as previously estimated, showing the significant influence of hydrodynamics. In three dimensions (with a 256 3 lattice), we estimate the growth as t 0.96 +/= 0.05 for both critical and off-critical quenches, in agreement with phenomenological theory

  5. Layered interfaces between immiscible liquids studied by density-functional theory and molecular-dynamics simulations.

    Science.gov (United States)

    Geysermans, P; Elyeznasni, N; Russier, V

    2005-11-22

    We present a study of the structure in the interface between two immiscible liquids by density-functional theory and molecular-dynamics calculations. The liquids are modeled by Lennard-Jones potentials, which achieve immiscibility by suppressing the attractive interaction between unlike particles. The density profiles of the liquids display oscillations only in a limited part of the simple liquid-phase diagram (rho,T). When approaching the liquid-vapor coexistence, a significant depletion appears while the layering behavior of the density profile vanishes. By analogy with the liquid-vapor interface and the analysis of the adsorption this behavior is suggested to be strongly related to the drying transition.

  6. Mechanical alloying of an immiscible α-Fe2O3-SnO2 ceramic

    DEFF Research Database (Denmark)

    Jiang, Jianzhong; Lin, Rong; Mørup, Steen

    1997-01-01

    in the immiscible ceramic oxide system. X-ray diffraction and Mossbauer spectroscopy investigations show that mechanical milling of alpha-Fe2O3 and SnO2 involves alloying on an atomic scale and that true solid solution formation occurs. We suggest that the high defect concentration and the chemical enthalpy of Fe3......+-O2--Sn4+ interfaces between nanostructured alpha-Fe2O3 and SnO2 regions may serve as a driving force for the formation of a solid solution in the immiscible ceramic system....

  7. 'The words will pass with the blowing wind': staff and parent views of the deferred consent process, with prior assent, used in an emergency fluids trial in two African hospitals.

    Directory of Open Access Journals (Sweden)

    Sassy Molyneux

    Full Text Available To document and explore the views and experiences of key stakeholders regarding the consent procedures of an emergency research clinical trial examining immediate fluid resuscitation strategies, and to discuss the implications for similar trials in future.A social science sub-study of the FEAST (Fluid Expansion As Supportive Therapy trial. Interviews were held with trial team members (n = 30, health workers (n = 15 and parents (n = 51 from two purposively selected hospitals in Soroti, Uganda, and Kilifi, Kenya.Overall, deferred consent with prior assent was seen by staff and parents as having the potential to protect the interests of both patients and researchers, and to avoid delays in starting treatment. An important challenge is that the validity of verbal assent is undermined when inadequate initial information is poorly understood. This concern needs to be balanced against the possibility that full prior consent on admission potentially causes harm through introducing delays. Full prior consent also potentially imposes worries on parents that clinicians are uncertain about how to proceed and that clinicians want to absolve themselves of any responsibility for the child's outcome (some parents' interpretation of the need for signed consent. Voluntariness is clearly compromised for both verbal assent and full prior consent in a context of such vulnerability and stress. Further challenges in obtaining verbal assent were: what to do in the absence of the household decision-maker (often the father; and how medical staff handle parents not giving a clear agreement or refusal.While the challenges identified are faced in all research in low-income settings, they are magnified for emergency trials by the urgency of decision making and treatment needs. Consent options will need to be tailored to particular studies and settings, and might best be informed by consultation with staff members and community representatives using a deliberative

  8. A note on the standard electron transfer potential at the interface between two immiscible electrolyte solutions

    Czech Academy of Sciences Publication Activity Database

    Samec, Zdeněk

    2009-01-01

    Roč. 55, č. 2 (2009), s. 75-81 ISSN 0034-6691 R&D Projects: GA ČR(CZ) GA203/07/1257 Institutional research plan: CEZ:AV0Z40400503 Keywords : interface between two immiscible electrolyte solutions * interfacial electron transfer * standard electron trasfer potential * homogeneous electron transfer Subject RIV: CG - Electrochemistry

  9. The Cauchy problem for a model of immiscible gas flow with large data

    Energy Technology Data Exchange (ETDEWEB)

    Sande, Hilde

    2008-12-15

    The thesis consists of an introduction and two papers; 1. The solution of the Cauchy problem with large data for a model of a mixture of gases. 2. Front tracking for a model of immiscible gas flow with large data. (AG) refs, figs

  10. Supercritical fluid reverse micelle separation

    Science.gov (United States)

    Fulton, J.L.; Smith, R.D.

    1993-11-30

    A method of separating solute material from a polar fluid in a first polar fluid phase is provided. The method comprises combining a polar fluid, a second fluid that is a gas at standard temperature and pressure and has a critical density, and a surfactant. The solute material is dissolved in the polar fluid to define the first polar fluid phase. The combined polar and second fluids, surfactant, and solute material dissolved in the polar fluid is maintained under near critical or supercritical temperature and pressure conditions such that the density of the second fluid exceeds the critical density thereof. In this way, a reverse micelle system defining a reverse micelle solvent is formed which comprises a continuous phase in the second fluid and a plurality of reverse micelles dispersed in the continuous phase. The solute material is dissolved in the polar fluid and is in chemical equilibrium with the reverse micelles. The first polar fluid phase and the continuous phase are immiscible. The reverse micelles each comprise a dynamic aggregate of surfactant molecules surrounding a core of the polar fluid. The reverse micelle solvent has a polar fluid-to-surfactant molar ratio W, which can vary over a range having a maximum ratio W[sub o] that determines the maximum size of the reverse micelles. The maximum ratio W[sub o] of the reverse micelle solvent is then varied, and the solute material from the first polar fluid phase is transported into the reverse micelles in the continuous phase at an extraction efficiency determined by the critical or supercritical conditions. 27 figures.

  11. WebPASS Explorer (HR Personnel Management)

    Data.gov (United States)

    US Agency for International Development — WebPass Explorer (WebPASS Framework): USAID is partnering with DoS in the implementation of their WebPass Post Personnel (PS) Module. WebPassPS does not replace...

  12. Multi-pass spectroscopic ellipsometry

    International Nuclear Information System (INIS)

    Stehle, Jean-Louis; Samartzis, Peter C.; Stamataki, Katerina; Piel, Jean-Philippe; Katsoprinakis, George E.; Papadakis, Vassilis; Schimowski, Xavier; Rakitzis, T. Peter; Loppinet, Benoit

    2014-01-01

    Spectroscopic ellipsometry is an established technique, particularly useful for thickness measurements of thin films. It measures polarization rotation after a single reflection of a beam of light on the measured substrate at a given incidence angle. In this paper, we report the development of multi-pass spectroscopic ellipsometry where the light beam reflects multiple times on the sample. We have investigated both theoretically and experimentally the effect of sample reflectivity, number of reflections (passes), angles of incidence and detector dynamic range on ellipsometric observables tanΨ and cosΔ. The multiple pass approach provides increased sensitivity to small changes in Ψ and Δ, opening the way for single measurement determination of optical thickness T, refractive index n and absorption coefficient k of thin films, a significant improvement over the existing techniques. Based on our results, we discuss the strengths, the weaknesses and possible applications of this technique. - Highlights: • We present multi-pass spectroscopic ellipsometry (MPSE), a multi-pass approach to ellipsometry. • Different detectors, samples, angles of incidence and number of passes were tested. • N passes improve polarization ratio sensitivity to the power of N. • N reflections improve phase shift sensitivity by a factor of N. • MPSE can significantly improve thickness measurements in thin films

  13. Variable flexure-based fluid filter

    Science.gov (United States)

    Brown, Steve B.; Colston, Jr., Billy W.; Marshall, Graham; Wolcott, Duane

    2007-03-13

    An apparatus and method for filtering particles from a fluid comprises a fluid inlet, a fluid outlet, a variable size passage between the fluid inlet and the fluid outlet, and means for adjusting the size of the variable size passage for filtering the particles from the fluid. An inlet fluid flow stream is introduced to a fixture with a variable size passage. The size of the variable size passage is set so that the fluid passes through the variable size passage but the particles do not pass through the variable size passage.

  14. A comparative study of ternary Al-Sn-Cu immiscible alloys prepared by conventional casting and casting under high-intensity ultrasonic irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kotadia, H.R., E-mail: hiren.kotadia@kcl.ac.uk [Department of Physics, King' s College London, Strand, London WC2R 2LS (United Kingdom); Das, A. [Materials Research Centre, College of Engineering, Swansea University, Singleton Park, Swansea, SA2 8PP (United Kingdom); Doernberg, E.; Schmid-Fetzer, R. [Clausthal University of Technology, Institute of Metallurgy, Robert-Koch-Str. 42, D-38678 Clausthal-Zellerfeld (Germany)

    2011-12-15

    Highlights: Black-Right-Pointing-Pointer Systematic investigation on the solidification microstructure of ternary Al-Sn-Cu immiscible system aided by computational thermodynamics calculations. Black-Right-Pointing-Pointer Comparative study of conventional casting and casting under high-intensity ultrasonic irradiation. Black-Right-Pointing-Pointer Demonstrated the high effectiveness of ultrasound exposure during solidification. Black-Right-Pointing-Pointer Effect of cavitation on nucleation and the relative effects of cavitation and acoustic streaming on the dispersion of Sn-rich liquid phases have been explained from the experimental observation. Cavitation was found to promote fragmentation and dispersion of Sn-rich liquid leading to homogeneous dispersion of refined Sn phase. Microstructural modification was found to be contributed by cavitation and associated shockwave generation while bulk fluid flow under acoustic streaming was found to be less effective on the microstructure evolution. Black-Right-Pointing-Pointer Globular and highly refined {alpha}-Al formed near the radiator through enhanced heterogeneous nucleation in contrast to dendritic {alpha}-Al observed in conventional solidification. - Abstract: A comparative study on the microstructure of four ternary Al-Sn-Cu immiscible alloys, guided by the recent thermodynamic assessment of the system, was carried out with specific focus on the soft Sn particulate distribution in hard Al-rich matrix in the presence and absence of ultrasonic irradiation during solidification. The results clearly demonstrate high effectiveness of ultrasonication in promoting significantly refined and homogeneously dispersed microstructure, probably aided by enhanced nucleation and droplet fragmentation under cavitation. While conventional solidification produced highly segregated Sn phase at the centre and bottom of Sn-rich alloy ingots, ultrasonic treatment produced effective dispersion irrespective of the alloy constitution in

  15. An efficient IMPES-based, shifting matrix algorithm to simulate two-phase, immiscible flow in porous media with application to CO 2 sequestration in the subsurface

    KAUST Repository

    Salama, Amgad

    2012-01-01

    The flow of two or more immiscible fluids in porous media is ubiquitous particularly in oil industry. This includes secondary and tertiary oil recovery, CO2 sequestration, etc. Accurate predictions of the development of these processes are important in estimating the benefits, e.g., in the form of increased oil extraction, when using certain technology. However, this accurate prediction depends to a large extent on two things; the first is related to our ability to correctly characterize the reservoir with all its complexities and the second depends on our ability to develop robust techniques that solve the governing equations efficiently and accurately. In this work, we introduce a new robust and efficient numerical technique to solving the governing conservation laws which govern the movement of two immiscible fluids in the subsurface. This work will be applied to the problem of CO2 sequestration in deep saline aquifer; however, it can also be extended to incorporate more cases. The traditional solution algorithms to this problem are based on discretizing the governing laws on a generic cell and then proceed to the other cells within loops. Therefore, it is expected that, calling and iterating these loops several times can take significant amount of CPU time. Furthermore, if this process is done using programming languages which require repeated interpretation each time a loop is called like Matlab, Python or the like, extremely longer time is expected particularly for larger systems. In this new algorithm, the solution is done for all the nodes at once and not within loops. The solution methodology involves manipulating all the variables as column vectors. Then using shifting matrices, these vectors are sifted in such a way that subtracting relevant vectors produces the corresponding difference algorithm. It has been found that this technique significantly reduces the amount of CPU times compared with traditional technique implemented within the framework of

  16. Plagiogranites as late-stage immiscible liquids in ophiolite and mid-ocean ridge suites - An experimental study

    Science.gov (United States)

    Dixon, S.; Rutherford, M. J.

    1979-01-01

    A study of relationships between basic and acidic rocks was made by fractionating primitive basalt at low pressure anhydrous conditions at various fugacities. Fractionally crystallized basalt became increasingly enriched in iron which became silicate liquid immiscible, producing Fe-enriched basaltic and granitic liquids. The latter is similar to plagiogranites found in mid-oceanic rift (MOR) regions, showing that silicate liquid immiscibility could be the petrogenic process which produces plagiogranites in some MOR regions and ophiolites. The major problem in considering plagiogranites as products of silicate liquid immiscibility is absence of any description of the Fe-enriched conjugate liquid in the ophiolite or MOR literature, and the identification of this magma is essential for a definite case of silicate liquid immiscibility.

  17. Metal Immiscibility Route to Synthesis of Ultrathin Carbides, Borides, and Nitrides.

    Science.gov (United States)

    Wang, Zixing; Kochat, Vidya; Pandey, Prafull; Kashyap, Sanjay; Chattopadhyay, Soham; Samanta, Atanu; Sarkar, Suman; Manimunda, Praveena; Zhang, Xiang; Asif, Syed; Singh, Abhisek K; Chattopadhyay, Kamanio; Tiwary, Chandra Sekhar; Ajayan, Pulickel M

    2017-08-01

    Ultrathin ceramic coatings are of high interest as protective coatings from aviation to biomedical applications. Here, a generic approach of making scalable ultrathin transition metal-carbide/boride/nitride using immiscibility of two metals is demonstrated. Ultrathin tantalum carbide, nitride, and boride are grown using chemical vapor deposition by heating a tantalum-copper bilayer with corresponding precursor (C 2 H 2 , B powder, and NH 3 ). The ultrathin crystals are found on the copper surface (opposite of the metal-metal junction). A detailed microscopy analysis followed by density functional theory based calculation demonstrates the migration mechanism, where Ta atoms prefer to stay in clusters in the Cu matrix. These ultrathin materials have good interface attachment with Cu, improving the scratch resistance and oxidation resistance of Cu. This metal-metal immiscibility system can be extended to other metals to synthesize metal carbide, boride, and nitride coatings. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Inhomogeneity of block copolymers at the interface of an immiscible polymer blend

    Science.gov (United States)

    Ryu, Ji Ho; Kim, YongJoo; Lee, Won Bo

    2018-04-01

    We present the effects of structure and stiffness of block copolymers on the interfacial properties of an immiscible homopolymer blend. Diblock and two-arm grafted copolymers with variation in stiffness are modeled using coarse-grained molecular dynamics to compare the compatibilization efficiency, i.e., reduction of interfacial tension. Overall, grafted copolymers are located more compactly at the interface and show better compatibilization efficiency than diblock copolymers. In addition, an increase in the stiffness for one of the blocks of the diblock copolymers causes unusual inhomogeneous interfacial coverage due to bundle formation. However, an increase in the stiffness for one of blocks of the grafted copolymers prevents the bundle formation due to the branched chain. As a result, homogeneous interfacial coverage of homopolymer blends is realized with significant reduction of interfacial tension which makes grafted copolymer a better candidate for the compatibilizer of immiscible homopolymer blend.

  19. Subsurface migration of petroleum hydrocarbons: A case study of immiscible migration and chromatographic separation

    International Nuclear Information System (INIS)

    Dawson, H.E.

    1991-01-01

    The subsurface distribution of a leaked crude oil illustrates the combined influence of both the chemical and physical properties of soil and free product on the migration of petroleum hydrocarbons. Immiscible phase behavior was observed, as well as chromatographic-like separation of the lighter constituents of the crude oil from the heavier constituents. After downward migration through approximately 50 ft of unsaturated, heterogeneous alluvial sediments, the crude oil formed a horizontal plume on top of a perched, saturated zone. Immiscible phase trapping is evident from the occurrence of very high concentration of hydrocarbons in both the vertical and horizontal plumes. Samples taken from the vertical zone of contamination indicate a transition from heavier hydrocarbons near the surface to lighter hydrocarbons at depth. This phenomenon is attributed to chromatographic-like separation of the heavier hydrocarbons by the soil, possibly due to preferential solubility of the lighter hydrocarbons in percolating ran water

  20. Boiling of the Interface between Two Immiscible Liquids below the Bulk Boiling Temperatures of Both Components

    OpenAIRE

    Pimenova, Anastasiya V.; Goldobin, Denis S.

    2014-01-01

    We consider the problem of boiling of the direct contact of two immiscible liquids. An intense vapour formation at such a direct contact is possible below the bulk boiling points of both components, meaning an effective decrease of the boiling temperature of the system. Although the phenomenon is known in science and widely employed in technology, the direct contact boiling process was thoroughly studied (both experimentally and theoretically) only for the case where one of liquids is becomin...

  1. A Membrane‐Free Redox Flow Battery with Two Immiscible Redox Electrolytes

    OpenAIRE

    Navalpotro, Paula; Palma, Jesus; Anderson, Marc; Marcilla, Rebeca

    2017-01-01

    Abstract Flexible and scalable energy storage solutions are necessary for mitigating fluctuations of renewable energy sources. The main advantage of redox flow batteries is their ability to decouple power and energy. However, they present some limitations including poor performance, short‐lifetimes, and expensive ion‐selective membranes as well as high price, toxicity, and scarcity of vanadium compounds. We report a membrane‐free battery that relies on the immiscibility of redox electrolytes ...

  2. Gas Separation Membranes Derived from High-Performance Immiscible Polymer Blends Compatibilized with Small Molecules.

    Science.gov (United States)

    Panapitiya, Nimanka P; Wijenayake, Sumudu N; Nguyen, Do D; Huang, Yu; Musselman, Inga H; Balkus, Kenneth J; Ferraris, John P

    2015-08-26

    An immiscible polymer blend comprised of high-performance copolyimide 6FDA-DAM:DABA(3:2) (6FDD) and polybenzimidazole (PBI) was compatibilized using 2-methylimidazole (2-MI), a commercially available small molecule. Membranes were fabricated from blends of 6FDD:PBI (50:50) with and without 2-MI for H2/CO2 separations. The membranes demonstrated a matrix-droplet type microstructure as evident with scanning electron microscopy (SEM) imaging where 6FDD is the dispersed phase and PBI is the continuous phase. In addition, membranes with 2-MI demonstrated a uniform microstructure as observed by smaller and more uniformly dispersed 6FDD domains in contrast to 6FDD:PBI (50:50) blend membranes without 2-MI. This compatibilization effect of 2-MI was attributed to interfacial localization of 2-MI that lowers the interfacial energy similar to a surfactant. Upon the incorporation of 2-MI, the H2/CO2 selectivity improved remarkably, compared to the pure blend, and surpassed the Robeson's upper bound. To our knowledge, this is the first report of the use of a small molecule to compatibilize a high-performance immiscible polymer blend. This approach could afford a novel class of membranes in which immiscible polymer blends can be compatibilized in an economical and convenient fashion.

  3. A chemical approach toward low temperature alloying of immiscible iron and molybdenum metals

    Energy Technology Data Exchange (ETDEWEB)

    Nazir, Rabia [Department of Chemistry, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Applied Chemistry Research Centre, Pakistan Council of Scientific and Industrial Research Laboratories Complex, Lahore 54600 (Pakistan); Ahmed, Sohail [Department of Chemistry, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Mazhar, Muhammad, E-mail: mazhar42pk@yahoo.com [Department of Chemistry, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur (Malaysia); Akhtar, Muhammad Javed; Siddique, Muhammad [Physics Division, PINSTECH, P.O. Nilore, Islamabad (Pakistan); Khan, Nawazish Ali [Material Science Laboratory, Department of Physics, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Shah, Muhammad Raza [HEJ Research Institute of Chemistry, University of Karachi, Karachi 75270 (Pakistan); Nadeem, Muhammad [Physics Division, PINSTECH, P.O. Nilore, Islamabad (Pakistan)

    2013-11-15

    Graphical abstract: - Highlights: • Low temperature pyrolysis of [Fe(bipy){sub 3}]Cl{sub 2} and [Mo(bipy)Cl{sub 4}] homogeneous powder. • Easy low temperature alloying of immiscible metals like Fe and Mo. • Uniform sized Fe–Mo nanoalloy with particle size of 48–68 nm. • Characterization by EDXRF, AFM, XRPD, magnetometery, {sup 57}Fe Mössbauer and impedance. • Alloy behaves as almost superparamagnetic obeying simple –R(CPE)– circuit. - Abstract: The present research is based on a low temperature operated feasible method for the synthesis of immiscible iron and molybdenum metals’ nanoalloy for technological applications. The nanoalloy has been synthesized by pyrolysis of homogeneous powder precipitated, from a common solvent, of the two complexes, trisbipyridineiron(II)chloride, [Fe(bipy){sub 3}]Cl{sub 2}, and bipyridinemolybedenum(IV) chloride, [Mo(bipy)Cl{sub 4}], followed by heating at 500 °C in an inert atmosphere of flowing argon gas. The resulting nanoalloy has been characterized by using EDXRF, AFM, XRD, magnetometery, {sup 57}Fe Mössbauer and impedance spectroscopies. These results showed that under provided experimental conditions iron and molybdenum metals, with known miscibility barrier, alloy together to give (1:1) single phase material having particle size in the range of 48–66 nm. The magnetism of iron is considerably reduced after alloy formation and shows its trend toward superparamagnetism. The designed chemical synthetic procedure is equally feasible for the fabrication of other immiscible metals.

  4. A chemical approach toward low temperature alloying of immiscible iron and molybdenum metals

    International Nuclear Information System (INIS)

    Nazir, Rabia; Ahmed, Sohail; Mazhar, Muhammad; Akhtar, Muhammad Javed; Siddique, Muhammad; Khan, Nawazish Ali; Shah, Muhammad Raza; Nadeem, Muhammad

    2013-01-01

    Graphical abstract: - Highlights: • Low temperature pyrolysis of [Fe(bipy) 3 ]Cl 2 and [Mo(bipy)Cl 4 ] homogeneous powder. • Easy low temperature alloying of immiscible metals like Fe and Mo. • Uniform sized Fe–Mo nanoalloy with particle size of 48–68 nm. • Characterization by EDXRF, AFM, XRPD, magnetometery, 57 Fe Mössbauer and impedance. • Alloy behaves as almost superparamagnetic obeying simple –R(CPE)– circuit. - Abstract: The present research is based on a low temperature operated feasible method for the synthesis of immiscible iron and molybdenum metals’ nanoalloy for technological applications. The nanoalloy has been synthesized by pyrolysis of homogeneous powder precipitated, from a common solvent, of the two complexes, trisbipyridineiron(II)chloride, [Fe(bipy) 3 ]Cl 2 , and bipyridinemolybedenum(IV) chloride, [Mo(bipy)Cl 4 ], followed by heating at 500 °C in an inert atmosphere of flowing argon gas. The resulting nanoalloy has been characterized by using EDXRF, AFM, XRD, magnetometery, 57 Fe Mössbauer and impedance spectroscopies. These results showed that under provided experimental conditions iron and molybdenum metals, with known miscibility barrier, alloy together to give (1:1) single phase material having particle size in the range of 48–66 nm. The magnetism of iron is considerably reduced after alloy formation and shows its trend toward superparamagnetism. The designed chemical synthetic procedure is equally feasible for the fabrication of other immiscible metals

  5. Two compressible and immiscible flow in porous media: mathematical and numerical analysis

    International Nuclear Information System (INIS)

    Khalil, Z.

    2010-01-01

    The aim of this thesis is the study of Cauchy problem (existence of weak solutions) for three degenerate highly coupled parabolic systems modeling compressible immiscible flow in porous media. The motivation of this work is a benchmark of the GNR MoMaS, to study the impact of the gas flow due to the corrosion of ferrous materials in a radioactive waste storage site. This thesis is divided into three independent chapters. Firstly, we look at a problem modeling the flow of two immiscible phases and considering one phase is compressible and the other is incompressible (water/gas). Secondly, we consider the problem modeling two-compressible immiscible flow in porous media. An existence results for both problems established by a semi-discretization method. Finally, The fourth chapter is devoted to the construction and convergence of a multi-dimensional finite volume method (upwind scheme) for the gas-water model under the assumption that the gas density is a function of a global pressure. (author)

  6. Microfluidics with fluid walls.

    Science.gov (United States)

    Walsh, Edmond J; Feuerborn, Alexander; Wheeler, James H R; Tan, Ann Na; Durham, William M; Foster, Kevin R; Cook, Peter R

    2017-10-10

    Microfluidics has great potential, but the complexity of fabricating and operating devices has limited its use. Here we describe a method - Freestyle Fluidics - that overcomes many key limitations. In this method, liquids are confined by fluid (not solid) walls. Aqueous circuits with any 2D shape are printed in seconds on plastic or glass Petri dishes; then, interfacial forces pin liquids to substrates, and overlaying an immiscible liquid prevents evaporation. Confining fluid walls are pliant and resilient; they self-heal when liquids are pipetted through them. We drive flow through a wide range of circuits passively by manipulating surface tension and hydrostatic pressure, and actively using external pumps. Finally, we validate the technology with two challenging applications - triggering an inflammatory response in human cells and chemotaxis in bacterial biofilms. This approach provides a powerful and versatile alternative to traditional microfluidics.The complexity of fabricating and operating microfluidic devices limits their use. Walsh et al. describe a method in which circuits are printed as quickly and simply as writing with a pen, and liquids in them are confined by fluid instead of solid walls.

  7. North Texas Sediment Budget: Sabine Pass to San Luis Pass

    Science.gov (United States)

    2006-09-01

    concrete units have been placed over sand-filled fabric tube . .......................................33 Figure 28. Sand-filled fabric tubes protecting...system UTM Zone 15, NAD 83 Longshore drift directions King (in preparation) Based on wave hindcast statistics and limited buoy data Rollover Pass...along with descriptions of the jetties and limited geographic coordinate data1 (Figure 18). The original velum or Mylar sheets from which the report

  8. Mechanics of couple-stress fluid coatings

    Science.gov (United States)

    Waxman, A. M.

    1982-01-01

    The formal development of a theory of viscoelastic surface fluids with bending resistance - their kinematics, dynamics, and rheology are discussed. It is relevant to the mechanics of fluid drops and jets coated by a thin layer of immiscible fluid with rather general rheology. This approach unifies the hydrodynamics of two-dimensional fluids with the mechanics of an elastic shell in the spirit of a Cosserat continuum. There are three distinct facets to the formulation of surface continuum mechanics. Outlined are the important ideas and results associated with each: the kinematics of evolving surface geometries, the conservation laws governing the mechanics of surface continua, and the rheological equations of state governing the surface stress and moment tensors.

  9. Wave propagation in fluids models and numerical techniques

    CERN Document Server

    Guinot, Vincent

    2012-01-01

    This second edition with four additional chapters presents the physical principles and solution techniques for transient propagation in fluid mechanics and hydraulics. The application domains vary including contaminant transport with or without sorption, the motion of immiscible hydrocarbons in aquifers, pipe transients, open channel and shallow water flow, and compressible gas dynamics. The mathematical formulation is covered from the angle of conservation laws, with an emphasis on multidimensional problems and discontinuous flows, such as steep fronts and shock waves. Finite

  10. Heat Transfer Characteristics during Boiling of Immiscible Liquids Flowing in Narrow Rectangular Heated Channels

    Directory of Open Access Journals (Sweden)

    Yasuhisa Shinmoto

    2017-11-01

    Full Text Available The use of immiscible liquids for cooling of surfaces with high heat generation density is proposed based on the experimental verification of its superior cooling characteristics in fundamental systems of pool boiling and flow boiling in a tube. For the purpose of practical applications, however, heat transfer characteristics due to flow boiling in narrow rectangular channels with different small gap sizes need to be investigated. The immiscible liquids employed here are FC72 and water, and the gap size is varied as 2, 1, and 0.5 mm between parallel rectangular plates of 30 mm × 175 mm, where one plate is heated. To evaluate the effect of gap size, the heat transfer characteristics are compared at the same inlet velocity. The generation of large flattened bubbles in a narrow gap results in two opposite trends of the heat transfer enhancement due to thin liquid film evaporation and of the deterioration due to the extension of dry patch in the liquid film. The situation is the same as that observed for pure liquids. The latter negative effect is emphasized for extremely small gap sizes if the flow rate ratio of more-volatile liquid to the total is not reduced. The addition of small flow rate of less-volatile liquid can increase the critical heat flux (CHF of pure more-volatile liquid, while the surface temperature increases at the same time and assume the values between those for more-volatile and less-volatile liquids. By the selection of small flow rate ratio of more-volatile liquid, the surface temperature of pure less-volatile liquid can be decreased without reducing high CHF inherent in the less-volatile liquid employed. The trend of heat transfer characteristics for flow boiling of immiscible mixtures in narrow channels is more sensitive to the composition compared to the flow boiling in a round tube.

  11. Connecticut church passes genetics resolution.

    Science.gov (United States)

    Culliton, B J

    1984-11-09

    The Connecticut Conference of the United Church of Christ, which represents the largest Protestant denomination in the state, has passed a resolution affirming an ethical duty to do research on human gene therapy and is planning to form local church groups to study the scientific and ethical issues involved. The resolution is intended to counter an earlier one proposed by Jeremy Rifkin to ban all efforts at engineering specific traits into the human germline. The Rifkin proposal had been endorsed by a large number of religious leaders, including the head of the U.S. United Church of Christ, but was subsequently characterized by many of the church leaders as overly restrictive.

  12. Atomic arrangement in immiscible Ag–Cu alloys synthesized far-from-equilibrium

    International Nuclear Information System (INIS)

    Elofsson, V.; Almyras, G.A.; Lü, B.; Boyd, R.D.; Sarakinos, K.

    2016-01-01

    Physical attributes of multicomponent materials of a given chemical composition are determined by atomic arrangement at property-relevant length scales. A potential route to access a vast array of atomic configurations for material property tuning is by synthesis of multicomponent thin films using vapor fluxes with their deposition pattern modulated in the sub-monolayer regime. However, the applicability of this route for creating new functional materials is impeded by the fact that a fundamental understanding of the combined effect of sub-monolayer flux modulation, kinetics and thermodynamics on atomic arrangement is not available in the literature. Here we present a research strategy and verify its viability for addressing the aforementioned gap in knowledge. This strategy encompasses thin film synthesis using a route that generates multi-atomic fluxes with sub-monolayer resolution and precision over a wide range of experimental conditions, deterministic growth simulations and nanoscale microstructural probes. Investigations are focused on structure formation within the archetype immiscible Ag-Cu binary system, revealing that atomic arrangement at different length scales is governed by the arrival pattern of the film forming species, in conjunction with diffusion of near-surface Ag atoms to encapsulate 3D Cu islands growing on 2D Ag layers. The knowledge generated and the methodology presented herein provides the scientific foundation for tailoring atomic arrangement and physical properties in a wide range of miscible and immiscible multinary systems.

  13. Experimental Investigation of Extensional Deformation of Immiscible Droplets in a Laminar, Converging Flow

    Science.gov (United States)

    Sangli, Aditya; Arispe-Guzman, Marcelo; Armstrong, Connor; Bigio, David

    2017-11-01

    The deformation of an immiscible droplet in an extensional flow has been widely studied by researchers using experimental four-roll mills where the bulk liquid imposes a stagnation extensional deformation on the droplet. However, it is of vital interest to study the behavior of an immiscible droplet in a non-stagnant extensional flow which can be produced using a converging channel. A hyperbolic converging channel was built, which could produce a constant extensional rate in the center of the channel, and deformation of droplets of Castor oil injected in a matrix of Silicone oil was observed. Droplets injected in the center of the channel experienced a pure extensional deformation while the droplets injected at an offset position attained the affine state. The nature of the droplet deformation and the critical Capillary numbers are compared with the four-roll mill experiments. Additional experiments were performed with the initial position of the droplet being vertically off center. Higher strain rates were exhibited compared to the pure extensional flow condition. An analysis of the flow field helps explaining the phenomenon and provides insight into the droplet behavior.

  14. Fabrication of tissue engineering scaffolds through solid-state foaming of immiscible polymer blends

    International Nuclear Information System (INIS)

    Zhou Changchun; Li Wei; Ma Liang; Yao Donggang

    2011-01-01

    In scaffold-based tissue engineering, the fabrication process is important for producing suitable microstructures for seeded cells to grow and reformulate. In this paper, we present a new approach to scaffold fabrication by combining the solid-state foaming and the immiscible polymer-blending method. The proposed approach has the advantage of being versatile and able to create a wide range of pore size and porosity. The proposed method is studied with polylactic acid (PLA) and polystyrene (PS) blends. The interconnected porous structure was created by first foaming the PLA/PS blend and then extracting the PS phase. The solid-state foaming experiments were conducted under various conditions to achieve the desired pore sizes. It is shown that the PS phase of the PLA/PS blend can be extracted much faster in the foamed samples and the pore size of the scaffolds can be easily controlled with proper gas foaming parameters. The average pore size achieved in the foaming process ranged from 20 to 70 μm. After PS extraction, both pore size and porosity can be further improved. For example, the pore size and porosity increased from 48 μm and 49% to 59 μm and 67%, respectively, after the PS extraction process. The fabricated porous scaffolds were used to culture human osteoblast cells. Cells grew well and gradually formed a fibrous structure. The combined solid-state foaming and immiscible polymer blending method provides a new technique for fabricating tissue-engineering scaffolds.

  15. The immiscible aqueous solutions of alkyl phosphates. Study for the purpose of uranium extraction from phosphoric acid solutions

    International Nuclear Information System (INIS)

    Mauborgne, Bernard

    1979-01-01

    Systems of immiscible aqueous solutions composed by a phase rich in mineral salt and by another phase almost totally containing an organic salt, have been studied for years, with quaternary ammonium salts with an organic cation. The objective of this research is to study systems symmetric to the previous ones, i.e. with organic anions such as alkyl phosphates, and then to try to understand mechanisms of extraction of metals in these environments. Based on properties of immiscible aqueous solutions, an original three-phase process of liquid-liquid extraction has been developed, and is used to separate uranium in phosphoric acids with better performance than the existing industrial processes [fr

  16. The Swedish Blood Pass project.

    Science.gov (United States)

    Berglund, B; Ekblom, B; Ekblom, E; Berglund, L; Kallner, A; Reinebo, P; Lindeberg, S

    2007-06-01

    Manipulation of the blood's oxygen carrying capacity (CaO(2)) through reinfusion of red blood cells, injections of recombinant erythropoietin or by other means results in an increased maximal oxygen uptake and concomitantly enhanced endurance performance. Therefore, there is a need to establish a system--"A Blood Pass"--through which such illegal and unethical methods can be detected. Venous blood samples were taken under standardized conditions from 47 male and female Swedish national and international elite endurance athletes four times during the athletic year of the individual sport (beginning and end of the preparation period and at the beginning and during peak performance in the competition period). In these samples, different hematological values were determined. ON(hes) and OFF(hre) values were calculated according to the formula of Gore et al. A questionnaire regarding training at altitude, alcohol use and other important factors for hematological status was answered by the athletes. There were some individual variations comparing hematological values obtained at different times of the athletic year or at the same time in the athletic year but in different years. However, the median values of all individual hematological, ON(hes) and OFF(hre), values taken at the beginning and the end of the preparation or at the beginning and the end of the competition period, respectively, as well as median values for the preparation and competition periods in the respective sport, were all within the 95% confidence limit (CI) of each comparison. It must be mentioned that there was no gender difference in this respect. This study shows that even if there are some individual variations in different hematological values between different sampling times in the athletic year, median values of important hematological factors are stable over time. It must be emphasized that for each blood sample, the 95% CI in each athlete will be increasingly narrower. The conclusion is that

  17. Hazardous fluid leak detector

    Science.gov (United States)

    Gray, Harold E.; McLaurin, Felder M.; Ortiz, Monico; Huth, William A.

    1996-01-01

    A device or system for monitoring for the presence of leaks from a hazardous fluid is disclosed which uses two electrodes immersed in deionized water. A gas is passed through an enclosed space in which a hazardous fluid is contained. Any fumes, vapors, etc. escaping from the containment of the hazardous fluid in the enclosed space are entrained in the gas passing through the enclosed space and transported to a closed vessel containing deionized water and two electrodes partially immersed in the deionized water. The electrodes are connected in series with a power source and a signal, whereby when a sufficient number of ions enter the water from the gas being bubbled through it (indicative of a leak), the water will begin to conduct, thereby allowing current to flow through the water from one electrode to the other electrode to complete the circuit and activate the signal.

  18. The PASS project architectural model

    International Nuclear Information System (INIS)

    Day, C.T.; Loken, S.; Macfarlane, J.F.

    1994-01-01

    The PASS project has as its goal the implementation of solutions to the foreseen data access problems of the next generation of scientific experiments. The architectural model results from an evaluation of the operational and technical requirements and is described in terms of an abstract reference model, an implementation model and a discussion of some design aspects. The abstract reference model describes a system that matches the requirements in terms of its components and the mechanisms by which they communicate, but does not discuss policy or design issues that would be necessary to match the model to an actual implementation. Some of these issues are discussed, but more detailed design and simulation work will be necessary before choices can be made

  19. WebPASS ICASS (HR Personnel Management)

    Data.gov (United States)

    US Agency for International Development — WebPASS Joint Administrative Support Platforms Post Administrative Software Suite - U.S. Department of State Executive Officers application suite. Web.PASS is the...

  20. Inducing conductivity in immiscible PS/PP blends by a percolated polyaniline/PA filler selectively localised by specific interactions

    NARCIS (Netherlands)

    Bharatia, A.; Hejmady, P.; Cardinaels, R.; Seo, Jin Won; Moldenaers, P.; Maazouz, A.

    2017-01-01

    We describe an approach to develop conducting immiscible blends of polystyrene (PS) and polypropylene (PP) with a percolated polyaniline/polyamide (PANI/PA) filler in the presence of a SEBS-g-MA compatibilizer. The underlying principle of the work is the ability of the compatibilizer to concurrently

  1. The thermal performance of the two-pass, two-glass-cover solar air heater

    Energy Technology Data Exchange (ETDEWEB)

    Persad, P.; Sateunanathan, S.

    1983-08-01

    Analytic models are developed for the performance prediction of a two-glass-cover solar air heater operated in both the single-pass and two-pass modes. It is shown that the two-pass mode of operation is superior to the single-pass mode of operation over the range of collector inlet temperatures considered. This is seen to be mainly due to the fact that, in the two-pass mode of operation, the outer glass cover is cooled by the working fluid, thereby reducing the top losses. It is also shown that the performance in the two-pass mode of operation is independent of length, over the range of collector lengths considered, and that a critical plate spacing, dependent on the temperature level of operation of the collector, is indicated. Predicted values of performance are in good agreement with experimental results.

  2. Triplets pass their pressure test

    CERN Multimedia

    2007-01-01

    All the LHC inner triplets have now been repaired and are in position. The first ones have passed their pressure tests with flying colours. The repaired inner triplet at LHC Point 1, right side (1R). Ranko Ostojic (on the right), who headed the team responsible for repairing the triplets, shows the magnet to Robert Zimmer, President of the University of Chicago and of Fermi Research Alliance, who visited CERN on 20th August.Three cheers for the triplets! All the LHC inner triplets have now been repaired and are in position in the tunnel. Thanks to the mobilisation of a multidisciplinary team from CERN and Fermilab, assisted by the KEK Laboratory and the Lawrence Berkeley National Laboratory (LBNL), a solution has been found, tested, validated and applied. At the end of March this year, one of the inner triplets at Point 5 failed to withstand a pressure test. A fault was identified in the supports of two out of the three quadruple magne...

  3. Vertical vibration dynamics of acoustically levitated drop containing two immiscible liquids

    Science.gov (United States)

    Zang, Duyang; Zhai, Zhicong; Li, Lin; Lin, Kejun; Li, Xiaoguang; Geng, Xingguo

    2016-09-01

    We have studied the levitation and oscillation dynamics of complex drops containing two immiscible liquids. Two types of drops, core-shell drop and abnormal-shaped drop, have been obtained depending on the levitation procedures. The oscillation dynamics of the drops have been studied using a high speed camera. It has been found that the oscillation of the abnormal-shaped drop has a longer oscillation period and decays much faster than that of the core-shell drop, which cannot be accounted for by the air resistance itself. The acoustic streaming induced by ultrasound may bring an additional force against the motion of the drop due to the Bernoulli effect. This is responsible for the enhanced damping during the oscillation in acoustic levitation.

  4. Forced chemical mixing in immiscible alloys during severe plastic deformation at elevated temperatures

    International Nuclear Information System (INIS)

    Vo, Nhon Q.; Odunuga, Samson; Bellon, Pascal; Averback, Robert S.

    2009-01-01

    The forced chemical mixing of atoms in model immiscible alloys during severe plastic deformation (SPD) has been investigated as a function of temperature and the heat of mixing using molecular dynamics computer simulations. At low temperatures, A 75 B 25 alloys form solid solutions during SPD for heats of mixing less than ∼20 kJ mol -1 , but tend to phase separate at larger values. At high temperatures these alloys show more extensive precipitation, with the precipitate morphology dependent on the heat of mixing. Analysis of the high-temperature mixing kinetics reveals that the precipitation process involves two separate mechanisms. The first derives from long-range diffusion mediated by shear-induced vacancies, while the second is due to local rearrangements of atoms induced by the forced mixing of atoms.

  5. Anomalous Behaviors of Block Copolymers at the Interface of an Immiscible Polymer Blend

    Science.gov (United States)

    Ryu, Ji Ho; Lee, Won Bo

    We investigate the effects of structure and stiffness of block copolymers on the interface of an immiscible polymer blend using coarse-grained molecular dynamics (CGMD) simulation. The diblock and grafted copolymers, which are described by Kremer and Grest bead spring model, are used to compare the compatibilization efficiency, that is, reduction of the interfacial tension. It is found that, overall, the grafted copolymers are located more compactly at the interface and show better compatibilization efficiency than diblock copolymers. In addition, it is noted that an increase in the stiffness of one block of diblock copolymer causes inhomogeneous interfacial coverage due to bundle formation among the stiff blocks and orientational constraint on bundled structures near the interface, which makes copolymers poor compatibilizers. The dependence of anomalous orientational constraint on the chain length of homopolymers is also investigated. Theoretical and Computational Soft Matters Lab.

  6. A Navier-Stokes/Cahn-Hilliard model for the simulation of three phase immiscible incompressible flows

    International Nuclear Information System (INIS)

    Celine Lapuerta; Bruno Piar; Franck Boyer; Philippe Angot; Michel Quintard

    2005-01-01

    This paper presents a Navier-Stokes/Cahn-Hilliard model designed for incompressible flows of three immiscible phases, characterized by different surface tensions and without phase change. This physical context is relevant to study the late phase of a hypothetical severe accident in a nuclear pressurized water reactor. Thanks to a suitable choice of a free energy and a particular form of the Cahn-Hilliard equation, the evolution of the three phases is described by only two order parameters. Moreover, this model allows the simulation of purely two phase flows as a limiting case: no artificial apparition of the third phase occurs if this later is physically absent which contrasts with others models of the literature. We examine the spreading of a liquid lens at the interface between two stratified phases. We present results showing that the method gives correct contact angles and pressure jumps, at equilibrium. (authors)

  7. Investigation of metastable immiscibility in nuclear-waste-glasses. I-III

    International Nuclear Information System (INIS)

    Egnell, J.; Larsen, J.G.; Moeller, L.; Roed, G.

    1981-12-01

    Metastable liquid-liquid separation in glasses can often cause significant changes in physical and chemical properties of the original homogeneous glass. In some technical borosilicate glasses this phenomenon is used to change the chemical durability of the glass. For potential nuclear-waste-glasses the slow cooling through the temperature range 550 0 C - 700 0 C may lead to such a liquid-liquid phase separation. In order to investigate the susceptibility of phase separation of nuclear-waste-glasses, two KBS model glasses, ABS-39 and ABS-41, were investigated. Two of the subsequent reports are concerned with this problem. The third report also takes into consideration the effects of MoO 3 on the immiscibility gap. The maximum amount of MoO 3 that can be dissolved in ABS-39 and ABS 41 is also determined. (Auth.)

  8. A Study on the Violent Interactions of an Immiscible Drop impacting on a Superheated Pool

    KAUST Repository

    Alchalabi, Mohamad

    2014-05-01

    ABSTRACT A Study on the Violent Interactions of an Immiscible Drop Impacting on a Superheated Pool Mohamad Alchalabi The interactions between two immiscible liquids of different temperatures can be violent to the extent of causing harm to individuals, or damage to equipment, especially when used in the industry. Only a few studies investigated these interactions but they could not produce the violent interactions often reported by the industry, and therefore their results did not help much to develop clear understanding of the dynamics of these interactions. In this work, a high speed imaging system operated at 100,000 frames per second was utilized to record the events and phenomena taking place upon the impact of Perfluorohexane droplet at room temperature onto a hot soybean oil pool at temperatures as high as 300 ºC. The impact velocity was varied by varying the height of the droplet before it pinches off under its own weight. The recorded events identified the occurrence of vortex ring vapor explosions, weak and strong nucleate boiling, and film boiling. An impact velocity vs. oil temperature diagram identifying the regions in which each of these phenomena takes place was generated, and the dynamics driving their occurrences were explored. The vortex ring vapor explosions were found to become less violent as the impact velocity was increased, which was attributed to the existence of a smaller amount of liquid Perfluorohexane within the rings at high speed impacts, which does evaporate but does not expand violently. Weak nucleate boiling occurred at very high impact velocities relatively. As the temperature is increased, however, they start 5 turning into strong nucleate boiling. The strong nucleate boiling usually starts right upon impact, and when the temperature of the oil at one impact velocity is increased, it starts turning into film boiling, in which the liquid Perfluorohexane is covered by a vapor layer of its own vapor.

  9. On Numerical Methods for Including the Effect of Capillary Pressure Forces on Two-phase, Immiscible Flow in a Layered Porous Medium

    Energy Technology Data Exchange (ETDEWEB)

    Ersland, B.G.

    1996-05-01

    This mathematical doctoral thesis contains the theory, algorithms and numerical simulations for a heterogeneous oil reservoir. It presents the equations, which apply to immiscible and incompressible two-phase fluid flow in the reservoir, including the effect of capillary pressure forces, and emphasises in particular the interior boundary conditions at the interface between two sediments. Two different approaches are discussed. The first approach is to decompose the computational domain along the interior boundary and iterate between the subdomains until mass balance is achieved. The second approach accounts for the interior boundary conditions in the basis in which the solution is expanded, the basis being discontinuous over the interior boundaries. An overview of the construction of iterative solvers for partial differential equations by means of Schwartz methods is given, and the algorithm for local refinement with Schwartz iterations as iterative solver is described. The theory is then applied to a core plug problem in one and two space dimensions and the results of different methods compared. A general description is given of the computer simulation model, which is implemented in C++. 64 refs., 49 figs., 7 tabs.

  10. Oil price pass-through into inflation

    International Nuclear Information System (INIS)

    Chen, Shiu-Sheng

    2009-01-01

    This paper uses data from 19 industrialized countries to investigate oil price pass-through into inflation across countries and over time. A time-varying pass-through coefficient is estimated and the determinants of the recent declining effects of oil shocks on inflation are investigated. The appreciation of the domestic currency, a more active monetary policy in response to inflation, and a higher degree of trade openness are found to explain the decline in oil price pass-through. (author)

  11. Photoacoustic Soot Spectrometer (PASS) Instrument Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Dubey, M [Los Alamos National Laboratory; Springston, S [Brookhaven National Laboratory; Koontz, A [Pacific Northwest National Laboratory; Aiken, A [Los Alamos National Laboratory

    2013-01-17

    The photoacoustic soot spectrometer (PASS) measures light absorption by aerosol particles. As the particles pass through a laser beam, the absorbed energy heats the particles and in turn the surrounding air, which sets off a pressure wave that can be detected by a microphone. The PASS instruments deployed by ARM can also simultaneously measure the scattered laser light at three wavelengths and therefore provide a direct measure of the single-scattering albedo. The Operator Manual for the PASS-3100 is included here with the permission of Droplet Measurement Technologies, the instrument’s manufacturer.

  12. Possibilities of the fish pass restoration

    Science.gov (United States)

    Čubanová, Lea

    2018-03-01

    According to the new elaborated methodology of the Ministry of Environment of the Slovak Republic: Identification of the appropriate fish pass types according to water body typology (2015) each barrier on the river must be passable. On the barriers or structures without fish passes new ones should be design and built and on some water structures with existed but nonfunctional fish passes must be realized reconstruction or restoration of such objects. Assessment should be done in terms of the existing migratory fish fauna and hydraulic conditions. Fish fauna requirements resulting from the ichthyological research of the river section with barrier. Hydraulic conditions must than fulfil these requirements inside the fish pass body.

  13. An efficient implicit-pressure/explicit- saturation-method-based shifting-matrix algorithm to simulate two-phase, immiscible flow in porous media with application to CO2 sequestration in the subsurface

    KAUST Repository

    Salama, Amgad

    2013-07-04

    The flow of two or more immiscible fluids in porous media is widespread, particularly in the oil industry. This includes secondary and tertiary oil recovery and carbon dioxide (CO2) sequestration. Accurate predictions of the development of these processes are important in estimating the benefits and consequences of the use of certain technologies. However, this accurate prediction depends--to a large extent--on two things. The first is related to our ability to correctly characterize the reservoir with all its complexities; the second depends on our ability to develop robust techniques that solve the governing equations efficiently and accurately. In this work, we introduce a new robust and efficient numerical technique for solving the conservation laws that govern the movement of two immiscible fluids in the subsurface. As an example, this work is applied to the problem of CO2 sequestration in deep saline aquifers; however, it can also be extended to incorporate more scenarios. The traditional solution algorithms to this problem are modeled after discretizing the governing laws on a generic cell and then proceed to the other cells within loops. Therefore, it is expected that calling and iterating these loops multiple times can take a significant amount of computer time. Furthermore, if this process is performed with programming languages that require repeated interpretation each time a loop is called, such as Matlab, Python, and others, much longer time is expected, particularly for larger systems. In this new algorithm, the solution is performed for all the nodes at once and not within loops. The solution methodology involves manipulating all the variables as column vectors. By use of shifting matrices, these vectors are shifted in such a way that subtracting relevant vectors produces the corresponding difference algorithm. It has been found that this technique significantly reduces the amount of central-processing-unit (CPU) time compared with a traditional

  14. Formation of disorder aluminium zones in an immiscible lead-aluminium system

    International Nuclear Information System (INIS)

    Huang, R Z; Zhang, L H; Sui, M L; Wang, Y M

    2004-01-01

    High resolution transmission electron microscopy (HRTEM) observations show evidence for the formation of disorder Al zones around some faceted Pb inclusions embedded in an Al matrix in immiscible lead-aluminium samples, which were prepared by a melt-spun method and then aged for about two months at room temperature. Furthermore, it is found that, both before and after ageing, all such Pb inclusions have a cube-cube orientation relationship with the Al matrix. The results of molecular dynamics (MD) simulations give an extensive analysis of the formation of the disorder Al zones and provide a reasonable explanation for the HRTEM finding: the existence of oxygen soluted in the Pb inclusions at higher temperatures may lead to the formation of the disorder Al zone in the aged sample. The dependence of the thickness of the disorder Al zone on the amount of oxygen soluted in the Pb inclusion at higher temperatures, and the average stress in the equilibrium configuration of a MD cell, is discussed

  15. Electrochemical alloying of immiscible Ag and Co for their structural and magnetic analyses

    Energy Technology Data Exchange (ETDEWEB)

    Santhi, Kalavathy [Material Science Centre, Department of Nuclear Physics, University of Madras, Guindy Campus, Chennai 600025 (India); Department of Physics, Women’s Christian College, Chennai 600006 (India); Kumarsan, Dhanapal [Material Science Centre, Department of Nuclear Physics, University of Madras, Guindy Campus, Chennai 600025 (India); Vengidusamy, Naryanan [Department of Inorganic Chemistry, University of Madras, Guindy Campus, Chennai 600025 (India); Arumainathan, Stephen, E-mail: stephen_arum@hotmail.com [Material Science Centre, Department of Nuclear Physics, University of Madras, Guindy Campus, Chennai 600025 (India)

    2017-07-01

    Highlights: • Ag-Co alloy has been prepared using pulsed electrodeposition method. • Wide range of Ag composition in the alloy was obtained. • XPS measurement evident the Ag and Co in metallic nature. • The electrodeposition method develop dendrite like morphology. • Detailed analysis of magnetic behaviour is carried out. - Abstract: Electrochemical alloying of immiscible Ag and Co was carried out at different current densities from electrolytes of two different concentrations, after optimizing the electrolytic bath and operating conditions. The samples obtained were characterized using X-ray diffraction to confirm the simultaneous deposition of Ag and Co and to determine their crystallographic structure. The atomic percentage of Ag and Co contents in the granular alloy was determined by ICP-OES analysis. The XPS spectra were observed to confirm the presence of Ag and Co in the metallic form in the granular alloy samples. The micrographs observed using scanning and transmission electron microscopes threw light on the surface morphology and the size of the particles. The magnetic nature of the samples was analyzed at room temperature by a vibration sample magnetometer. Their magnetic phase transition while heating was also studied to provide further evidence for the magnetic behaviour and the structure of the deposits.

  16. Atomistic study of self-diffusion in Cu-Ag immiscible alloy system

    International Nuclear Information System (INIS)

    Zhang Jianmin; Chen Gouxiang; Xu Kewei

    2006-01-01

    Combining molecular dynamic (MD) simulation with modified analytic embedded-atom method (MAEAM) potential, the formation, migration and activation energies have been calculated for four-kind migrations of Cu vacancy and three-kind migrations of Ag vacancy in Cu-Ag immiscible alloy system. The equilibrium concentration of Cu vacancies is greater than that of Ag vacancies owing to the formation energy of Cu vacancy (1.012 eV) is lower than that of Ag vacancy (1.169 eV). Comparing the migration or activation energy needed for four-kind migrations of Cu vacancy and three-kind migrations of Ag vacancy show that the favorable migration mechanism is the nearest-neighbor (NN) jump for Cu vacancy, while the straight [0 1 0] six-jump cycle (6JC) for Ag vacancy. Furthermore, the activation energy of the NN jump of Cu vacancy (2.164 eV) is lower than that of straight [0 1 0] 6JC of Ag vacancy (2.404 eV) also show that the former is more favorable. We conclude accordingly that the primary migration mechanism is the NN jump of an abundance of Cu vacancies

  17. The effect of additives interaction on the miscibility and crystal structure of two immiscible biodegradable polymers

    Directory of Open Access Journals (Sweden)

    Ahmed Mohamed El-Hadi

    2014-01-01

    Full Text Available Poly lactic acid (PLLA is a promising biopolymer, obtained from polymerization of lactic acid that is derived from renewable resources through fermentation. The characteristic brittleness of PLLA is attributed to slow crystallization rates, which results in the formation of the large spherulites. Its glass temperature is relative high, above room temperature and close to 60 ºC, and therefore its applications are limited. The additives poly((R-3-hydroxybutyrate (PHB, poly(vinyl acetate (PVAc and tributyl citrate (TBC were used as compatibilizers in the biodegradable polymer blend of (PLLA/PPC. Results from DSC and POM analysis indicated that the blends of PLLA and PPC are immiscible. However, the blends with additives are miscible. TBC as plasticizer was added to PLLA to reduce its Tg. PVAc was used as compatibilizer to improve the miscibility between PLLA and PPC. FT-IR showed about 7 cm-1 shift in the C=O peak in miscible blends due to physical interactions. POM experiments together with the results of DSC and WAXD showed that PHB enhances the crystallization behavior of PLLA by acting as bio nuclei and the crystallization process can occur more quickly. Consequently an increase was observed in the peak intensity in WAXD.

  18. Immiscible silicate liquids at high pressure: the influence of melt structure on elemental partitioning

    Energy Technology Data Exchange (ETDEWEB)

    Vicenzi, E [Princeton Materials Laboratory, Princeton, NJ (United States); Green, T H [Macquarie Univ., North Ryde, NSW (Australia); Sie, S H [Commonwealth Scientific and Industrial Research Organisation (CSIRO), North Ryde, NSW (Australia). Div. of Exploration Geoscience

    1994-12-31

    Micro-PIXE analyses have been applied to study partitioning of trace elements between immiscible silicate melts stabilised at 0.5 and 1.0 GPa over a temperature range of 1160-1240 deg C in the system SiO{sub 2}-FeO-Al{sub 2}0{sub 3}-K{sub 2}0 (+P{sub 2}0{sub 5}). The system was doped with a suite of trace elements of geochemical interest: Rb, Ba, Pb, Sr, La, Ce, Sm, Ho, Y, Lu, Th, U, Zr, Hf, Nb and Ta at approximately 200 ppm level for all elements except for the REE`s, Ba and Ta (600-1200 ppm). Trace element partitioning was found to be a complex function of cation field strength (charge/radius{sup 2}). Although field strength is important in determining the nature and degree of partitioning, the authors emphasised that it is only one component of the underlying mechanism for the way in which elements distribute themselves between two silicate liquids. 8 refs., 2 figs.

  19. Solid State Self-Healing System: Effects of Using Immiscible Healing Agents

    International Nuclear Information System (INIS)

    Noor Nabilah Muhamad; Mohd Suzeren Mohd Jamil

    2015-01-01

    The solid state self-healing system was obtained by employs a thermosetting epoxy resin, into which a thermoplastic is dissolved. The aim of this study is to identify the effect of using immiscible healing agents, which are polyvinyl chloride and polyvinyl alcohol, on solid state self-healing system. Healing was achieved by heating the fractured resins to a specific temperature; above their glass transition temperature (Tg) which obtained from dynamic mechanical analysis (DMA) in order for thermal expansion to occur. The thermal properties and bonding formed in the epoxy resins were characterized by means of Fourier Transform Infrared Spectroscopy (FTIR). Izod impact test was performed in preliminary work. Further work then has been done using compact tension test to demonstrate details self-healing capability of the different specimens. Under compact tension test, it was found that healable resin with PVC has highest healing efficiency followed PVA with 7.4 % and 3 % of average percentage healing efficiencies respectively. These results are due to the different solubility parameters of the thermoset/ network and thermoplastic polymer which led to the phase separation. Morphological studies using microscope optic prove the fracture-healing process and morphological properties of the resins. (author)

  20. Immiscible silicate liquids at high pressure: the influence of melt structure on elemental partitioning

    Energy Technology Data Exchange (ETDEWEB)

    Vicenzi, E. [Princeton Materials Laboratory, Princeton, NJ (United States); Green, T.H. [Macquarie Univ., North Ryde, NSW (Australia); Sie, S.H. [Commonwealth Scientific and Industrial Research Organisation (CSIRO), North Ryde, NSW (Australia). Div. of Exploration Geoscience

    1993-12-31

    Micro-PIXE analyses have been applied to study partitioning of trace elements between immiscible silicate melts stabilised at 0.5 and 1.0 GPa over a temperature range of 1160-1240 deg C in the system SiO{sub 2}-FeO-Al{sub 2}0{sub 3}-K{sub 2}0 (+P{sub 2}0{sub 5}). The system was doped with a suite of trace elements of geochemical interest: Rb, Ba, Pb, Sr, La, Ce, Sm, Ho, Y, Lu, Th, U, Zr, Hf, Nb and Ta at approximately 200 ppm level for all elements except for the REE`s, Ba and Ta (600-1200 ppm). Trace element partitioning was found to be a complex function of cation field strength (charge/radius{sup 2}). Although field strength is important in determining the nature and degree of partitioning, the authors emphasised that it is only one component of the underlying mechanism for the way in which elements distribute themselves between two silicate liquids. 8 refs., 2 figs.

  1. Solution of the equations for one-dimensional, two-phase, immiscible flow by geometric methods

    Science.gov (United States)

    Boronin, Ivan; Shevlyakov, Andrey

    2018-03-01

    Buckley-Leverett equations describe non viscous, immiscible, two-phase filtration, which is often of interest in modelling of oil production. For many parameters and initial conditions, the solutions of these equations exhibit non-smooth behaviour, namely discontinuities in form of shock waves. In this paper we obtain a novel method for the solution of Buckley-Leverett equations, which is based on geometry of differential equations. This method is fast, accurate, stable, and describes non-smooth phenomena. The main idea of the method is that classic discontinuous solutions correspond to the continuous surfaces in the space of jets - the so-called multi-valued solutions (Bocharov et al., Symmetries and conservation laws for differential equations of mathematical physics. American Mathematical Society, Providence, 1998). A mapping of multi-valued solutions from the jet space onto the plane of the independent variables is constructed. This mapping is not one-to-one, and its singular points form a curve on the plane of the independent variables, which is called the caustic. The real shock occurs at the points close to the caustic and is determined by the Rankine-Hugoniot conditions.

  2. Interfacial transport characteristics in a gas-liquid or an immiscible liquid-liquid stratified flow

    International Nuclear Information System (INIS)

    Inoue, A.; Aoki, S.; Aritomi, M.; Kozawa, Y.

    1982-01-01

    This paper is a review for an interfacial transport characteristics of mass, momentum and energy in a gas-liquid or a immiscible liquid-liquid stratified flow with wavy interface which have been studied in our division. In the experiment, a characteristic of wave motion and its effect to the turbulence near the interface as well as overall flow characteristics like pressure drop, position of the interface were investigated in an air-water, an air-mercury and a water-liquid metal stratified flow. On the other hand, several models based on the mixing length model and a two-equation model of turbulence, with special interfacial boundary conditions in which the wavy surface was regarded as a rough surface correspond to the wavy height, a source of turbulent energy equal to the wave energy and a damped-turbulence due to the surface tension, were proposed to predict the flow characteristics and the interfacial heat transfer in a fully developed and an undeveloped stratified flow and examined by the experimental data. (author)

  3. Non-traditional stable isotope behaviors in immiscible silica-melts in a mafic magma chamber.

    Science.gov (United States)

    Zhu, Dan; Bao, Huiming; Liu, Yun

    2015-12-01

    Non-traditional stable isotopes have increasingly been applied to studies of igneous processes including planetary differentiation. Equilibrium isotope fractionation of these elements in silicates is expected to be negligible at magmatic temperatures (δ(57)Fe difference often less than 0.2 per mil). However, an increasing number of data has revealed a puzzling observation, e.g., the δ(57)Fe for silicic magmas ranges from 0‰ up to 0.6‰, with the most positive δ(57)Fe almost exclusively found in A-type granitoids. Several interpretations have been proposed by different research groups, but these have so far failed to explain some aspects of the observations. Here we propose a dynamic, diffusion-induced isotope fractionation model that assumes Si-melts are growing and ascending immiscibly in a Fe-rich bulk magma chamber. Our model offers predictions on the behavior of non-traditional stable isotope such as Fe, Mg, Si, and Li that are consistent with observations from many A-type granitoids, especially those associated with layered intrusions. Diffusion-induced isotope fractionation may be more commonly preserved in magmatic rocks than was originally predicted.

  4. Solidification of Al-Sn-Cu Based Immiscible Alloys under Intense Shearing

    Science.gov (United States)

    Kotadia, H. R.; Doernberg, E.; Patel, J. B.; Fan, Z.; Schmid-Fetzer, R.

    2009-09-01

    The growing importance of Al-Sn based alloys as materials for engineering applications necessitates the development of uniform microstructures with improved performance. Guided by the recently thermodynamically assessed Al-Sn-Cu system, two model immiscible alloys, Al-45Sn-10Cu and Al-20Sn-10Cu, were selected to investigate the effects of intensive melt shearing provided by the novel melt conditioning by advanced shear technology (MCAST) unit on the uniform dispersion of the soft Sn phase in a hard Al matrix. Our experimental results have confirmed that intensive melt shearing is an effective way to achieve fine and uniform dispersion of the soft phase without macro-demixing, and that such dispersed microstructure can be further refined in alloys with precipitation of the primary Al phase prior to the demixing reaction. In addition, it was found that melt shearing at 200 rpm and 60 seconds will be adequate to produce fine and uniform dispersion of the Sn phase, and that higher shearing speed and prolonged shearing time can only achieve minor further refinement.

  5. Development of an Inclined Plate Extractor-Separator for Immiscible Liquids

    Directory of Open Access Journals (Sweden)

    Syed Zahoor ul Hassan Rizvi

    2009-10-01

    Full Text Available A new inclined plates extractor-separator is developed for operation with immiscible liquids in which extraction and separation is achieved in one unit contrary to mixer settlers. The inclined plates extractor-separator combines turbulent jets for contacting, and an inclined plate for separation of the two phases. The inclined plates extractor-separator does not have any moving part inside the vessel. This feature makes it free from the mechanical problems associated with conventional apparatus. The proposed inclined plates extractor-separator was operated in batch mode under various operating conditions to evaluate its performance on the basis of extraction efficiency. Water (light phase was used as solvent to extract ethyl acetate from a heavy phase pool of tetrachloroethylene and ethyl acetate. The ethyl acetate content was analysed using chromatography. A hydrodynamic study was carried out using high speed photography to understand the mechanisms occurring during mass transfer across the two phases. Furthermore, it was found that the proposed inclined plate extractor-separator reduces the overall operating time by 67% and consumes only 13% of the power in comparison to a mixer-settler. A hydraulic power consumption comparison with a mixer settler and a gullwing extractor-separator is also presented.

  6. A planar lens based on the electrowetting of two immiscible liquids

    International Nuclear Information System (INIS)

    Liu Chaoxuan; Park, Jihwan; Choi, Jin-Woo

    2008-01-01

    This paper reports the development and characterization of a planar liquid lens based on electrowetting. The working concept of electrowetting two immiscible liquids is demonstrated with measurement and characterization of contact angles with regard to externally applied electric voltages. Consequently, a planar liquid lens is designed and implemented based on this competitive electrowetting. A droplet of silicone oil confined in an aqueous solution (1% KCl) works as a liquid lens. Electrowetting then controls the shape of the confined silicone oil and the focal length of the liquid lens varies depending upon an applied dc voltage. A unique feature of this lens design is the double-ring planar electrodes beneath the hydrophobic substrate. While an outer ring electrode provides an initial boundary for the silicone oil droplet, an inner ring works as the actuation electrode for the lens. Further, the planar electrodes, instead of vertical or out-of-plane wall electrodes, facilitate the integration of liquid lenses into microfluidic systems. With the voltage applied in the range of 50–250 V, the confined silicone oil droplet changed its shape and the optical magnification of a 3 mm-diameter liquid lens was clearly demonstrated. Moreover, focal lengths of liquid lenses with diameters of 2 mm, 3 mm and 4 mm were characterized, respectively. The obtained results suggest that a larger lens diameter yields a longer focal length and a wider range of focal length change in response to voltage. The demonstrated liquid lens has a simple structure and is easy to fabricate

  7. A Membrane‐Free Redox Flow Battery with Two Immiscible Redox Electrolytes

    Science.gov (United States)

    Navalpotro, Paula; Palma, Jesus; Anderson, Marc

    2017-01-01

    Abstract Flexible and scalable energy storage solutions are necessary for mitigating fluctuations of renewable energy sources. The main advantage of redox flow batteries is their ability to decouple power and energy. However, they present some limitations including poor performance, short‐lifetimes, and expensive ion‐selective membranes as well as high price, toxicity, and scarcity of vanadium compounds. We report a membrane‐free battery that relies on the immiscibility of redox electrolytes and where vanadium is replaced by organic molecules. We show that the biphasic system formed by one acidic solution and one ionic liquid, both containing quinoyl species, behaves as a reversible battery without any membrane. This proof‐of‐concept of a membrane‐free battery has an open circuit voltage of 1.4 V with a high theoretical energy density of 22.5 Wh L−1, and is able to deliver 90 % of its theoretical capacity while showing excellent long‐term performance (coulombic efficiency of 100 % and energy efficiency of 70 %). PMID:28658538

  8. A Membrane-Free Redox Flow Battery with Two Immiscible Redox Electrolytes.

    Science.gov (United States)

    Navalpotro, Paula; Palma, Jesus; Anderson, Marc; Marcilla, Rebeca

    2017-10-02

    Flexible and scalable energy storage solutions are necessary for mitigating fluctuations of renewable energy sources. The main advantage of redox flow batteries is their ability to decouple power and energy. However, they present some limitations including poor performance, short-lifetimes, and expensive ion-selective membranes as well as high price, toxicity, and scarcity of vanadium compounds. We report a membrane-free battery that relies on the immiscibility of redox electrolytes and where vanadium is replaced by organic molecules. We show that the biphasic system formed by one acidic solution and one ionic liquid, both containing quinoyl species, behaves as a reversible battery without any membrane. This proof-of-concept of a membrane-free battery has an open circuit voltage of 1.4 V with a high theoretical energy density of 22.5 Wh L -1 , and is able to deliver 90 % of its theoretical capacity while showing excellent long-term performance (coulombic efficiency of 100 % and energy efficiency of 70 %). © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  9. Electrochemical alloying of immiscible Ag and Co for their structural and magnetic analyses

    International Nuclear Information System (INIS)

    Santhi, Kalavathy; Kumarsan, Dhanapal; Vengidusamy, Naryanan; Arumainathan, Stephen

    2017-01-01

    Highlights: • Ag-Co alloy has been prepared using pulsed electrodeposition method. • Wide range of Ag composition in the alloy was obtained. • XPS measurement evident the Ag and Co in metallic nature. • The electrodeposition method develop dendrite like morphology. • Detailed analysis of magnetic behaviour is carried out. - Abstract: Electrochemical alloying of immiscible Ag and Co was carried out at different current densities from electrolytes of two different concentrations, after optimizing the electrolytic bath and operating conditions. The samples obtained were characterized using X-ray diffraction to confirm the simultaneous deposition of Ag and Co and to determine their crystallographic structure. The atomic percentage of Ag and Co contents in the granular alloy was determined by ICP-OES analysis. The XPS spectra were observed to confirm the presence of Ag and Co in the metallic form in the granular alloy samples. The micrographs observed using scanning and transmission electron microscopes threw light on the surface morphology and the size of the particles. The magnetic nature of the samples was analyzed at room temperature by a vibration sample magnetometer. Their magnetic phase transition while heating was also studied to provide further evidence for the magnetic behaviour and the structure of the deposits.

  10. Density and adiabatic compressibility of the immiscible molten AgBr+LiCl mixture

    Energy Technology Data Exchange (ETDEWEB)

    Stepanov, Victor P. [Russian Academy of Sciences, Yekaterinburg (Russian Federation). Inst. of High-Temperature Electrochemistry; Ural Federal Univ., Yekaterinburg (Russian Federation); Kulik, Nina P. [Russian Academy of Sciences, Yekaterinburg (Russian Federation). Inst. of High-Temperature Electrochemistry

    2017-07-01

    The adiabatic compressibility, β, of the immiscible liquid mixture 0.52 LiCl+0.48 AgBr (the top of the miscibility gap) was experimentally investigated in the temperature range from the melting point to the critical mixing temperature using the sound velocity values, u, measured by the pulse method, and the density quantities, ρ, which were determined using the hydrostatic weight procedure based on the relationship β = u{sup -2}ρ{sup -1}. It is shown that the coefficients of the temperature dependencies for the compressibility and density of the upper and lower equilibrium phases have opposite signs because of the superposition of the intensity of the thermal motion of the ions and the change in the composition of the phases. The differences, Δβ and Δρ, in the magnitudes of the compressibility and density for the equilibrium phases decrease with temperature elevation. The temperature dependencies of the compressibility and density difference are described using the empirical equations Δβ ∼ (T{sub c}-T){sup 0.438} and Δρ ∼ (T{sub c}-T){sup 0.439}.

  11. Nanoparticle Assemblies at Fluid Interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Russell, Thomas P. [Univ. of Massachusetts, Amherst, MA (United States). Dept. of Polymer Science and Engineering

    2015-03-10

    A systematic study of the structure and dynamics of nanoparticles (NP) and NP-surfactants was performed. The ligands attached to both the NPs and NP-surfactants dictate the manner in which the nanoscopic materials assemble at fluid interfaces. Studies have shown that a single layer of the nanoscpic materials form at the interface to reduce the interactions between the two immiscible fluids. The shape of the NP is, also, important, where for spherical particles, a disordered, liquid-like monolayer forms, and, for nanorods, ordered domains at the interface is found and, if the monolayers are compressed, the orientation of the nanorods with respect to the interface can change. By associating end-functionalized polymers to the NPs assembled at the interface, NP-surfactants are formed that increase the energetic gain in segregating each NP at the interface which allows the NP-surfactants to jam at the interface when compressed. This has opened the possibility of structuring the two liquids by freezing in shape changes of the liquids.

  12. Message passing for quantified Boolean formulas

    International Nuclear Information System (INIS)

    Zhang, Pan; Ramezanpour, Abolfazl; Zecchina, Riccardo; Zdeborová, Lenka

    2012-01-01

    We introduce two types of message passing algorithms for quantified Boolean formulas (QBF). The first type is a message passing based heuristics that can prove unsatisfiability of the QBF by assigning the universal variables in such a way that the remaining formula is unsatisfiable. In the second type, we use message passing to guide branching heuristics of a Davis–Putnam–Logemann–Loveland (DPLL) complete solver. Numerical experiments show that on random QBFs our branching heuristics give robust exponential efficiency gain with respect to state-of-the-art solvers. We also manage to solve some previously unsolved benchmarks from the QBFLIB library. Apart from this, our study sheds light on using message passing in small systems and as subroutines in complete solvers

  13. How to pass higher English colour

    CERN Document Server

    Bridges, Ann

    2009-01-01

    How to Pass is the Number 1 revision series for Scottish qualifications across the three examination levels of Standard Grade, Intermediate and Higher! Second editions of the books present all of the material in full colour for the first time.

  14. Message Passing Framework for Globally Interconnected Clusters

    International Nuclear Information System (INIS)

    Hafeez, M; Riaz, N; Asghar, S; Malik, U A; Rehman, A

    2011-01-01

    In prevailing technology trends it is apparent that the network requirements and technologies will advance in future. Therefore the need of High Performance Computing (HPC) based implementation for interconnecting clusters is comprehensible for scalability of clusters. Grid computing provides global infrastructure of interconnecting clusters consisting of dispersed computing resources over Internet. On the other hand the leading model for HPC programming is Message Passing Interface (MPI). As compared to Grid computing, MPI is better suited for solving most of the complex computational problems. MPI itself is restricted to a single cluster. It does not support message passing over the internet to use the computing resources of different clusters in an optimal way. We propose a model that provides message passing capabilities between parallel applications over the internet. The proposed model is based on Architecture for Java Universal Message Passing (A-JUMP) framework and Enterprise Service Bus (ESB) named as High Performance Computing Bus. The HPC Bus is built using ActiveMQ. HPC Bus is responsible for communication and message passing in an asynchronous manner. Asynchronous mode of communication offers an assurance for message delivery as well as a fault tolerance mechanism for message passing. The idea presented in this paper effectively utilizes wide-area intercluster networks. It also provides scheduling, dynamic resource discovery and allocation, and sub-clustering of resources for different jobs. Performance analysis and comparison study of the proposed framework with P2P-MPI are also presented in this paper.

  15. Generation of micro- and nano-droplets containing immiscible solutions in view of optical studies

    Science.gov (United States)

    Nastasa, V.; Karapantsios, T.; Samaras, K.; Dafnopatidou, E.; Pradines, V.; Miller, R.; Pascu, M. L.

    2010-08-01

    The multiple resistances to treatment, developed by bacteria and malignant tumors require finding alternatives to the existing medicines and treatment procedures. One of them is strengthening the effects of cytostatics by improving the delivery method. Such a method is represented by the use of medicines as micro/nano-droplets. This method can reduce the substance consumption by generating drug micro-droplets incorporated in substances that can favour a faster localization, than the classical mode of medicine administration, to the tumor tissues. This paper contains the results concerning the generation and study of micro/nano-droplets and the generation of micro-droplets with an inner core (medicine) and a thin layer covering it. We have measured the surface tension at water/air interface and water/oil interface for a medicine (Vancomycin) and we have generated and measured droplets of medicine containing a layer of Vitamin A by using a double capillary system. The micro/nano-droplets may be produced by mixing of two immiscible solutions in particular conditions (high rotating speed and/or high pressure difference). For this we have studied the generation of emulsions of vitamin A diluted in sunflower oil and a solution of a surfactant Tween 80 in distilled water. The concentration of surfactant in water was typically 4*10-5M. We have studied in a batch stirred tank system the dependence of the droplet dimensions in emulsion, function of the mixing rotation speed, agitation time and components ratio. The droplet diameters were measured using a Malvern light scattering instrument type Mastersizer Hydro 2000M. We have obtained droplets with diameters smaller than 100 nm; the diameters distribution exhibited a peak at 65 nm.

  16. Effects of shear during the cooling on the rheology and morphology of immiscible polymer blends

    International Nuclear Information System (INIS)

    Hammani, S; Moulai-Mostefa, N; Benyahia, L; Tassin, J F

    2014-01-01

    The aim of this work was the generation of a microfibrillar structure in immiscible polymer blends using a new technique. The blend polymer model is the emulsion formed by a mixture of polypropylene (PP) with polystyrene (PS) in the proportion of PP10/PS90. In the first case the pellets of polystyrene and polypropylene were blended on the twin-screw mini extruder in the classical manner with different shear rates. In the second case, the same blend was prepared in the same way followed by a dynamic cooling at different shear rates. The phase morphologies of PP in the blend were determined by Scanning Electron Microscopy on two directions (transversal and longitudinal direction to the flow). In the two cases, the dispersed phase size decreased with the increase of the shear rate in the extruder. An anomaly was registered in the classical method at 200 rpm, where the size of the dispersed phase increases with the increase of the shear rate. The dynamic cooling technique recorded smaller diameters (4 to 5 times) of the dispersed phase compared to the conventional technique. In addition, the reappearance of the microfilaments at 200rpm was observed. The rheological properties were determined by RS100 (Thermo Scientific Haake). Using this new technique, it was noticed that he elastic modulus increases with one decade compared to the classical method and the complex viscosity decreases with the increase of the shear rate. An anomaly was registered in the classical technique, where the dynamic viscosity at 200rpm increases with increasing the shear rate in the extruder

  17. Flow split characterization of two immiscible phases with different wettability scenarios: a numerical investigation using a coupled Cahn-Hilliard and Navier-Stokes system

    KAUST Repository

    Bao, Kai

    2017-12-23

    Numerical investigation of flow branching of two-phase immiscible fluids in a Y-shaped, planner channel is conducted by solving the coupled Cahn-Hilliard and Naiver-Stokes system with finite element method. In this system a horizontal channel is branched into two identical and symmetric branches with the walls of the channels assigned several different wettability values. The studied scenarios consider a blob of one phase initially encompassed by the other phase. When an applied pressure difference induces flow, it is found that the motion of the blob in the two branches is significantly influenced by the wettability conditions at the channel walls. For the scenarios in which symmetric wettability configurations are applied, the blob divides equally among the two branches. For all the other scenarios in which the wettability configurations are asymmetric, the blob splits unequally. Comparisons between the different scenarios are performed in terms of the volume of the blob in each branch to investigate the percentage of the blob volume moving in each branch. In addition, we also considered the effect of the flow rate on the branching scenarios. In this work it is demonstrated that even though the pressure gradient is the same among the two symmetric branches, the phases partition differently when asymmetric wettability conditions are applied. The significance of this work may be that it provides evidences that relative permeability (a concept that has been introduced in the study of multiphase flow in porous media) may be more complex than just a mere scalar quantity function of saturation. It also highlights the importance of including the effects of wettability conditions in capillary pressure relationships

  18. Lattice Boltzmann model for three-phase viscoelastic fluid flow

    Science.gov (United States)

    Xie, Chiyu; Lei, Wenhai; Wang, Moran

    2018-02-01

    A lattice Boltzmann (LB) framework is developed for simulation of three-phase viscoelastic fluid flows in complex geometries. This model is based on a Rothman-Keller type model for immiscible multiphase flows which ensures mass conservation of each component in porous media even for a high density ratio. To account for the viscoelastic effects, the Maxwell constitutive relation is correctly introduced into the momentum equation, which leads to a modified lattice Boltzmann evolution equation for Maxwell fluids by removing the normal but excess viscous term. Our simulation tests indicate that this excess viscous term may induce significant errors. After three benchmark cases, the displacement processes of oil by dispersed polymer are studied as a typical example of three-phase viscoelastic fluid flow. The results show that increasing either the polymer intrinsic viscosity or the elastic modulus will enhance the oil recovery.

  19. INVESTIGATION OF SINGLE-PASS/DOUBLE-PASS TECHNIQUES ON FRICTION STIR WELDING OF ALUMINIUM

    Directory of Open Access Journals (Sweden)

    N.A.A. Sathari

    2014-12-01

    Full Text Available The aim of this research is to study the effects of single-pass/ double-pass techniques on friction stir welding of aluminium. Two pieces of AA1100 with a thickness of 6.0 mm were friction stir welded using a CNC milling machine at rotational speeds of 1400 rpm, 1600 rpm and 1800 rpm respectively for single-pass and double-pass. Microstructure observations of the welded area were studied using an optical microscope. The specimens were tested by using a tensile test and Vickers hardness test to evaluate their mechanical properties. The results indicated that, at low rotational speed, defects such as ‘surface lack of fill’ and tunnels in the welded area contributed to a decrease in mechanical properties. Welded specimens using double-pass techniques show increasing values of tensile strength and hardness. From this investigation it is found that the best parameters of FSW welded aluminium AA1100 plate were those using double-pass techniques that produce mechanically sound joints with a hardness of 56.38 HV and 108 MPa strength at 1800 rpm compared to the single-pass technique. Friction stir welding, single-pass/ double-pass techniques, AA1100, microstructure, mechanical properties.

  20. Identification of immiscible NAPL contaminant sources in aquifers by a modified two-level saturation based imperialist competitive algorithm

    Science.gov (United States)

    Ghafouri, H. R.; Mosharaf-Dehkordi, M.; Afzalan, B.

    2017-07-01

    A simulation-optimization model is proposed for identifying the characteristics of local immiscible NAPL contaminant sources inside aquifers. This model employs the UTCHEM 9.0 software as its simulator for solving the governing equations associated with the multi-phase flow in porous media. As the optimization model, a novel two-level saturation based Imperialist Competitive Algorithm (ICA) is proposed to estimate the parameters of contaminant sources. The first level consists of three parallel independent ICAs and plays as a pre-conditioner for the second level which is a single modified ICA. The ICA in the second level is modified by dividing each country into a number of provinces (smaller parts). Similar to countries in the classical ICA, these provinces are optimized by the assimilation, competition, and revolution steps in the ICA. To increase the diversity of populations, a new approach named knock the base method is proposed. The performance and accuracy of the simulation-optimization model is assessed by solving a set of two and three-dimensional problems considering the effects of different parameters such as the grid size, rock heterogeneity and designated monitoring networks. The obtained numerical results indicate that using this simulation-optimization model provides accurate results at a less number of iterations when compared with the model employing the classical one-level ICA. A model is proposed to identify characteristics of immiscible NAPL contaminant sources. The contaminant is immiscible in water and multi-phase flow is simulated. The model is a multi-level saturation-based optimization algorithm based on ICA. Each answer string in second level is divided into a set of provinces. Each ICA is modified by incorporating a new knock the base model.

  1. Fluid Mechanics.

    Science.gov (United States)

    Drazin, Philip

    1987-01-01

    Outlines the contents of Volume II of "Principia" by Sir Isaac Newton. Reviews the contributions of subsequent scientists to the physics of fluid dynamics. Discusses the treatment of fluid mechanics in physics curricula. Highlights a few of the problems of modern research in fluid dynamics. Shows that problems still remain. (CW)

  2. Setting pass scores for clinical skills assessment.

    Science.gov (United States)

    Liu, Min; Liu, Keh-Min

    2008-12-01

    In a clinical skills assessment, the decision to pass or fail an examinee should be based on the test content or on the examinees' performance. The process of deciding a pass score is known as setting a standard of the examination. This requires a properly selected panel of expert judges and a suitable standard setting method, which best fits the purpose of the examination. Six standard setting methods that are often used in clinical skills assessment are described to provide an overview of the standard setting process.

  3. Setting Pass Scores for Clinical Skills Assessment

    Directory of Open Access Journals (Sweden)

    Min Liu

    2008-12-01

    Full Text Available In a clinical skills assessment, the decision to pass or fail an examinee should be based on the test content or on the examinees' performance. The process of deciding a pass score is known as setting a standard of the examination. This requires a properly selected panel of expert judges and a suitable standard setting method, which best fits the purpose of the examination. Six standard setting methods that are often used in clinical skills assessment are described to provide an overview of the standard setting process.

  4. Single beam pass migmacell method and apparatus

    International Nuclear Information System (INIS)

    Maglich, B.C.; Nering, J.E.; Mazarakis, M.G.; Miller, R.A.

    1976-01-01

    The invention provides improvements in migmacell apparatus and method by dispensing with the need for metastable confinement of injected molecular ions for multiple precession periods. Injected molecular ions undergo a 'single pass' through the reaction volume. By preconditioning the injected beam such that it contains a population distribution of molecules in higher vibrational states than in the case of a normal distribution, injected molecules in the single pass exper-ience collisionless dissociation in the migmacell under magnetic influence, i.e., so-called Lorentz dissociation. Dissociationions then form atomic migma

  5. Ultrastructural evaluation of multiple pass low energy versus single pass high energy radio-frequency treatment.

    Science.gov (United States)

    Kist, David; Burns, A Jay; Sanner, Roth; Counters, Jeff; Zelickson, Brian

    2006-02-01

    The radio-frequency (RF) device is a system capable of volumetric heating of the mid to deep dermis and selective heating of the fibrous septa strands and fascia layer. Clinically, these effects promote dermal collagen production, and tightening of these deep subcutaneous structures. A new technique of using multiple low energy passes has been described which results in lower patient discomfort and fewer side effects. This technique has also been anecdotally described as giving more reproducible and reliable clinical results of tissue tightening and contouring. This study will compare ultrastructural changes in collagen between a single pass high energy versus up to five passes of a multiple pass lower energy treatment. Three subjects were consented and treated in the preauricular region with the RF device using single or multiple passes (three or five) in the same 1.5 cm(2) treatment area with a slight delay between passes to allow tissue cooling. Biopsies from each treatment region and a control biopsy were taken immediately, 24 hours or 6 months post treatment for electron microscopic examination of the 0-1 mm and 1-2 mm levels. Sections of tissue 1 mm x 1 mm x 80 nm were examined with an RCA EMU-4 Transmission Electron Microscope. Twenty sections from 6 blocks from each 1 mm depth were examined by 2 blinded observers. The morphology and degree of collagen change in relation to area examined was compared to the control tissue, and estimated using a quantitative scale. Ultrastructural examination of tissue showed that an increased amount of collagen fibril changes with increasing passes at energies of 97 J (three passes) and 122 J (five passes), respectively. The changes seen after five multiple passes were similar to those detected after much more painful single pass high-energy treatments. This ultrastructural study shows changes in collagen fibril morphology with an increased effect demonstrated at greater depths of the skin with multiple low-fluence passes

  6. XNBR-grafted halloysite nanotube core-shell as a potential compatibilizer for immiscible polymer systems

    International Nuclear Information System (INIS)

    Paran, S.M.R.; Naderi, G.; Ghoreishy, M.H.R.

    2016-01-01

    Highlights: • Attached an utilitarian silane coupling agent to the HNT via a sol-gel method. • Developed and analyzed the HNT/XNBR core-shell particles via sol-gel technique. • Enhanced the reactivity of the surface of HNT through XNBR grafting. • The act of HNT/XNBR as a compatibilizer in PA6/NBR TPEs. • Immiscible Polymer System with a good balanced physical and mechanical properties. - Abstract: Halloysite nanotubes (HNTs) grafted with carboxylated nitrile byutadiene rubber (XNBR) were synthesized via a sol-gel method. The HNTs as an inorganic cores were pre-treated with 3-Glycidoxypropyl trimethoxysilane, then successfully coated with the XNBR as an organic shell. The properties of XNBR-grafted HNTs were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The results suggested that the XNBR grafted to the surfaces of HNTs successfully. Then the TPE nanocomposites based on polyamide-6 (PA6) and nitrile butadiene rubber (NBR) containing various XNBR-grafted and pristine HNTs were prepared via a direct melt mixing method. The morphology, mechanical, dynamic mechanical and rheological properties of the prepared TPE nanocomposites were investigated. The results show that the XNBR-grafted HNTs can effectively improve the morphology and mechanical properties of the PA6/NBR TPEs. The morphology study of the prepared nanocomposites show that the effect of XNBR-grafted HNTs on the size reduction of NBR phase is markedly more effective than the pristine HNTs and rose by 50% in the same concentrations. Mechanical measurements show that the Young’s modulus of the TPE nanocomposites rose by 60% in just 7 wt% of XNBR-grafted HNT loading. The results indicate that the introduction of HNT/XNBR core-shells into the PA6/NBR TPEs can enhances the interfacial interactions

  7. Evolution of Immiscibly Blended Functionalized Polymers with Respect to Cure Parameters and Formulation

    Science.gov (United States)

    Heller, Nicholas Walter Medicus

    Powder coatings are becoming ubiquitous in the coating marketplace due to the absence of solvents in their formulation, but they have yet to see implementation in low-reflectance outdoor applications. This demand could be met by utilizing polymer blends formulated with low loadings of matting agents and pigments. The goal of this research is a thorough characterization of prototype low-reflectance coatings through several analytical techniques. Prototypical thermoset blends consist of functionalized polyurethanes rendered immiscible by differences in polar and hydrogen bonding characteristics, resulting in a surface roughened by droplet domains. Analysis of both pigmented and control clear films was performed. This research project had three primary aims: (1) determine the composition of the resin components of the polymer blend; (2) to monitor the evolution of domains before and during curing of clear polymer blends; (3) to monitor the evolution of these domains when pigments are added to these blends. The clear films enabled unhindered analysis by Fourier transform infrared (FTIR) and Raman spectroscopy on the binder. However, these domains provided no spectroscopic signatures despite their observation by optical microscopy. This necessitated the development of a new procedure for cross-section preparation that leaves no contamination from polishing media, which enabled Raman mapping of the morphology via an introduced marker peak from styrene monomer. The clears were analyzed as a powder and as films that were quenched at various cure-times using FTIR, Raman, transmission electron microscopy (TEM), and thermomechanical methods to construct a model of coating evolution based on cure parameters and polymer dynamics. Domains were observed in the powder, and underwent varying rates of coarsening as the cure progressed. TEM, scanning electron microscopy and thermomechanical methods were also used on pigmented systems at different states of the cure, including in

  8. XNBR-grafted halloysite nanotube core-shell as a potential compatibilizer for immiscible polymer systems

    Energy Technology Data Exchange (ETDEWEB)

    Paran, S.M.R.; Naderi, G., E-mail: g.naderi@ippi.ac.ir; Ghoreishy, M.H.R.

    2016-09-30

    Highlights: • Attached an utilitarian silane coupling agent to the HNT via a sol-gel method. • Developed and analyzed the HNT/XNBR core-shell particles via sol-gel technique. • Enhanced the reactivity of the surface of HNT through XNBR grafting. • The act of HNT/XNBR as a compatibilizer in PA6/NBR TPEs. • Immiscible Polymer System with a good balanced physical and mechanical properties. - Abstract: Halloysite nanotubes (HNTs) grafted with carboxylated nitrile byutadiene rubber (XNBR) were synthesized via a sol-gel method. The HNTs as an inorganic cores were pre-treated with 3-Glycidoxypropyl trimethoxysilane, then successfully coated with the XNBR as an organic shell. The properties of XNBR-grafted HNTs were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The results suggested that the XNBR grafted to the surfaces of HNTs successfully. Then the TPE nanocomposites based on polyamide-6 (PA6) and nitrile butadiene rubber (NBR) containing various XNBR-grafted and pristine HNTs were prepared via a direct melt mixing method. The morphology, mechanical, dynamic mechanical and rheological properties of the prepared TPE nanocomposites were investigated. The results show that the XNBR-grafted HNTs can effectively improve the morphology and mechanical properties of the PA6/NBR TPEs. The morphology study of the prepared nanocomposites show that the effect of XNBR-grafted HNTs on the size reduction of NBR phase is markedly more effective than the pristine HNTs and rose by 50% in the same concentrations. Mechanical measurements show that the Young’s modulus of the TPE nanocomposites rose by 60% in just 7 wt% of XNBR-grafted HNT loading. The results indicate that the introduction of HNT/XNBR core-shells into the PA6/NBR TPEs can enhances the interfacial interactions

  9. Problems in Microgravity Fluid Mechanics: G-Jitter Convection

    Science.gov (United States)

    Homsy, G. M.

    2005-01-01

    This is the final report on our NASA grant, Problems in Microgravity Fluid Mechanics NAG3-2513: 12/14/2000 - 11/30/2003, extended through 11/30/2004. This grant was made to Stanford University and then transferred to the University of California at Santa Barbara when the PI relocated there in January 2001. Our main activity has been to conduct both experimental and theoretical studies of instabilities in fluids that are relevant to the microgravity environment, i.e. those that do not involve the action of buoyancy due to a steady gravitational field. Full details of the work accomplished under this grant are given below. Our work has focused on: (i) Theoretical and computational studies of the effect of g-jitter on instabilities of convective states where the convection is driven by forces other than buoyancy (ii) Experimental studies of instabilities during displacements of miscible fluid pairs in tubes, with a focus on the degree to which these mimic those found in immiscible fluids. (iii) Theoretical and experimental studies of the effect of time dependent electrohydrodynamic forces on chaotic advection in drops immersed in a second dielectric liquid. Our objectives are to acquire insight and understanding into microgravity fluid mechanics problems that bear on either fundamental issues or applications in fluid physics. We are interested in the response of fluids to either a fluctuating acceleration environment or to forces other than gravity that cause fluid mixing and convection. We have been active in several general areas.

  10. Experimental study of extent and rate of gravity drainage of oil from matrix into fractures in presence of miscible and immiscible CO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Asghari, K.; Torabi, F. [Regina Univ., SK (Canada)

    2007-07-01

    The use of miscible carbon dioxide (CO{sub 2}) injection to improve oil recovery in naturally fractured reservoirs was discussed. The main production mechanism in fractured reservoirs is gravity drainage. The performance of this process is a function of a series of parameters such as fracture-matrix geometry, size, and matrix-fracture flow interaction. Both viscosity and density of oil and injected CO{sub 2} play important roles in the case of miscible CO{sub 2}. This paper presented the results of an experimental study of the effect of injecting CO{sub 2} into fractured media and its influence on the performance of gravity drainage and ultimate oil production. Both miscible and immiscible schemes for CO{sub 2} were examined in this study. In order to simulate a matrix with surrounding fractures, a steel holder was specifically designed to allow for an open space around a core of 30 cm long and 5 cm in diameter. CO{sub 2} and normal decane were used as solvent and oil, respectively. All experiments were conducted at constant temperature of 35 degrees C, and six series of experiments were carried out at 250, 500, 750, 1000, 1250, and 1500 psi. The produced oil was collected and measured continuously under the pressure and temperature conditions of the experiments. It was shown that injecting CO{sub 2} at higher pressures substantially improves the recovery factor of gravity drainage mechanism in fractured media. The injection of CO{sub 2} in fractures at pressures below minimum miscibility pressures (MMP) can recover up to 19 per cent of oil in-place (OIP). However, at miscible conditions, oil recovery can increase to more than 50 per cent of OIP. At a pressure much above MMP of CO{sub 2}, ultimate recovery may decrease due to the presence of denser fluid in fractures, which could prevent flow of fluid from matrix into fractures. It was concluded that CO{sub 2} injection in fractured reservoir may be a viable option for combined CO{sub 2} EOR and storage projects

  11. Generalizing Galileo's Passe-Dix Game

    Science.gov (United States)

    Hombas, Vassilios

    2012-01-01

    This article shows a generalization of Galileo's "passe-dix" game. The game was born following one of Galileo's [G. Galileo, "Sopra le Scoperte dei Dadi" (Galileo, Opere, Firenze, Barbera, Vol. 8). Translated by E.H. Thorne, 1898, pp. 591-594] explanations on a paradox that occurred in the experiment of tossing three fair "six-sided" dice.…

  12. Message passing with parallel queue traversal

    Science.gov (United States)

    Underwood, Keith D [Albuquerque, NM; Brightwell, Ronald B [Albuquerque, NM; Hemmert, K Scott [Albuquerque, NM

    2012-05-01

    In message passing implementations, associative matching structures are used to permit list entries to be searched in parallel fashion, thereby avoiding the delay of linear list traversal. List management capabilities are provided to support list entry turnover semantics and priority ordering semantics.

  13. TREsPASS Book 3: Creative Engagements

    NARCIS (Netherlands)

    Coles-Kemp, Lizzie; Hall, Peter

    2016-01-01

    In this book we examine the role that creative security engagements have played in the TREsPASS project. These engagements are part of a wider creative securities approach that explores the contributions that social practices make to protection of data and information. Our most popular creative

  14. Passing the Bond Issue (with Related Video)

    Science.gov (United States)

    Erickson, Paul W.

    2011-01-01

    When a bond referendum comes around for a school district, it often is the culmination of years of planning, strategizing and communicating to the public. Especially in these economic times, passing a building referendum is challenging. Complete transparency among the superintendent, school board and community is essential to communicate the…

  15. Modeling drivers' passing duration and distance in a virtual environment

    Directory of Open Access Journals (Sweden)

    Haneen Farah

    2013-07-01

    The main contribution of this paper is in the empirical models developed for passing duration and distance which highlights the factors that affect drivers' passing behavior and can be used to enhance the passing models in simulation programs.

  16. Interface-driven alloying and metallic glass formation in nano-multilayers in an immiscible Y-Nb system

    International Nuclear Information System (INIS)

    Chen, Y.G.; Liu, B.X.; Nanjing Univ.

    1999-01-01

    Several new amorphous alloys were obtained in an immiscible Y-Nb system by room temperature 190 keV xenon ion mixing of Y-Nb multilayered films, which were designed to include a sufficient fraction of interfacial atoms and thus possessed a high free energy comparable to that of the amorphous state. In addition, two metastable f.c.c. phases were formed in Y-rich and Nb-rich multilayered films, respectively. The growth kinetics of the f.c.c. phases and their effect on the composition range of amorphization are also discussed. To understand the observed unusual alloying behaviors, a Gibbs free-energy diagram was constructed based on Miedema's model. The diagram included the free-energy curves of all the involved phases as well as that of the Y-Nb multilayered films including the extra interfacial free energy and thus gave a qualitative and reasonable interpretation to the formation of metastable alloys upon ion mixing. Furthermore, some multilayered films with a sufficient fraction of interfacial atoms were subjected to steady-state thermal annealing, which also resulted in the formation of the Y-Nb amorphous phases, suggesting that alloying in this immiscible system was actually driven by the interfacial free energy

  17. Smart candle soot coated membranes for on-demand immiscible oil/water mixture and emulsion switchable separation.

    Science.gov (United States)

    Li, Jian; Zhao, Zhihong; Li, Dianming; Tian, Haifeng; Zha, Fei; Feng, Hua; Guo, Lin

    2017-09-21

    Oil/water separation is of great importance for the treatment of oily wastewater, including immiscible light/heavy oil-water mixtures, oil-in-water or water-in-oil emulsions. Smart surfaces with responsive wettability have received extensive attention especially for controllable oil/water separation. However, traditional smart membranes with a switchable wettability between superhydrophobicity and superhydrophilicity are limited to certain responsive materials and continuous external stimuli, such as pH, electrical field or light irradiation. Herein, a candle soot coated mesh (CSM) with a larger pore size and a candle soot coated PVDF membrane (CSP) with a smaller pore size with underwater superoleophobicity and underoil superhydrophobicity were successfully fabricated, which can be used for on-demand immiscible oil/water mixtures and surfactants-stabilized oil/water emulsion separation, respectively. Without any continuous external stimulus, the wettability of our membranes could be reversibly switched between underwater superoleophobicity and underoil superhydrophobicity simply by drying and washing alternately, thus achieving effective and switchable oil/water separation with excellent separation efficiency. We believe that such smart materials will be promising candidates for use in the removal of oil pollutants in the future.

  18. Fundamental problems on immiscibility, crystallization, and chemical interaction between stainless steel 304 and glasses for radioactivewaste glasses

    International Nuclear Information System (INIS)

    Inoue, Tadashi; Yokoyama, Hayaichi

    1982-01-01

    Immiscibility and crystallization, and chemical interaction with stainless steel, SUS 304, which is designed as a canister material, were investigated on non-radioactive glasses with simulated waste of 26.4 wt%. Although glasses whose initial color was black changed to yellow or yellow-brown by heat-treatment at 600 0 C, the change of color was hardly observed by the treatment at 850 0 C. Molybdenum oxide and molybdate were detected in all heat-treated glasses. It was deduced that the compounds were existing as meta-stable particle corresponding to immiscibility particle at 600 0 C and as stable crystallized particle at 850 0 C. The chemical interaction occurred at the interface between glasses and SUS 304, whose surface was attacked by boundary corrosion proceeding to uniform corrosion with increasing temperature and time. Chromium oxide layer was mainly formed in the region suffered chemical interaction. It was deduced that the chemical interaction was moderated due to the formation of protective layer, which mainly consisted of nickel oxide, at the same time as the formation of Cr 2 O 3 layer. (author)

  19. Salinity effects during immiscible displacement in porous media: electrokinetic stabilization of viscous fingering

    Science.gov (United States)

    Mirzadeh, Mohammad; Bazant, Martin

    2017-11-01

    Interfacial instabilities are ubiquitous in Fluid Mechanics and have been one of the main the subjects of pattern formation. However, these instabilities could lead to inefficiencies which are undesired in many applications. For instance, viscous fingering results in residual trapping of oil during secondary recovery when a low-viscosity fluid, e.g. water, is used for injection. In their seminal work, Saffman and Taylor showed that the onset of this instability is controlled by the viscosity ratio of the two fluids. However, other physiochemical processes could enhance or suppress viscous fingering. Here we consider the role of salinity effects on the front stability. Our recent theory suggests that viscous fingering could be controlled, and even suppressed, by appropriately injecting electric currents. However, even in the absence of any external currents, strong electrokinetic coupling (present in small pores when the electric double layers overlap) can reduce viscous fingering by increasing the ``effective viscosity'' of the injected fluid. These findings suggest that it might be possible to improve extraction efficiencies by appropriately controlling the salt concentration of the injected fluid.

  20. Fluids engineering

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    Fluids engineering has played an important role in many applications, from ancient flood control to the design of high-speed compact turbomachinery. New applications of fluids engineering, such as in high-technology materials processing, biotechnology, and advanced combustion systems, have kept up unwaining interest in the subject. More accurate and sophisticated computational and measurement techniques are also constantly being developed and refined. On a more fundamental level, nonlinear dynamics and chaotic behavior of fluid flow are no longer an intellectual curiosity and fluid engineers are increasingly interested in finding practical applications for these emerging sciences. Applications of fluid technology to new areas, as well as the need to improve the design and to enhance the flexibility and reliability of flow-related machines and devices will continue to spur interest in fluids engineering. The objectives of the present seminar were: to exchange current information on arts, science, and technology of fluids engineering; to promote scientific cooperation between the fluids engineering communities of both nations, and to provide an opportunity for the participants and their colleagues to explore possible joint research programs in topics of high priority and mutual interest to both countries. The Seminar provided an excellent forum for reviewing the current state and future needs of fluids engineering for the two nations. With the Seminar ear-marking the first formal scientific exchange between Korea and the United States in the area of fluids engineering, the scope was deliberately left broad and general

  1. Convective boiling heat transfer of mixture of immiscible two-liquids

    International Nuclear Information System (INIS)

    Hijikata, K.; Ito, H.; Mori, Y.

    1987-01-01

    Thermal energy conversion of low or middle temperature difference to electric power is conventionally made by the Rankine cycle using the organic compound as a working fluid. However, the energy conversion efficiency from thermal energy to electric power is limited by the pinch point temperature difference in the high temperature side heat exchanging. In order to avoid the efficiency ceiling due to the pinch point temperature difference, utilization of mixture of miscible two liquids as the working fluid of the Rankine cycle has been proposed and its cycle efficiency has been calculated. However, in the miscible mixture, mutual diffusion process is considered to greatly affect the thermo-fluid characteristics, but has not been clarified yet because of its complexity

  2. Buffer fluid

    Energy Technology Data Exchange (ETDEWEB)

    Mirzadzhanzade, A Kh; Dedusanko, G Ya; Dinaburg, L S; Markov, Yu M; Rasizade, Ya N; Rozov, V N; Sherstnev, N M

    1979-08-30

    A drilling fluid is suggested for separating the drilling and plugging fluids which contains as the base increased solution of polyacrylamide and additive. In order to increase the viscoelastic properties of the liquid with simultaneous decrease in the periods of its fabrication, the solution contains as an additive dry bentonite clay. In cases of the use of a buffer fluid under conditions of negative temperatures, it is necessary to add to it table salt or ethylene glycol.

  3. Contact conditions in skin-pass rolling

    DEFF Research Database (Denmark)

    Kijima, Hideo; Bay, Niels

    2007-01-01

    The special contact conditions in skin-pass rolling of steel strip is analysed by studying plane strain upsetting of thin sheet with low reduction applying long narrow tools and dry friction conditions. An extended sticking region is estimated by an elasto-plastic FEM analysis of the plane strain...... upsetting. This sticking region causes a highly inhomogeneous elasto-plastic deformation with large influence of work-hardening and friction. A numerical analysis of skin-pass rolling shows the same contact conditions, i.e. an extended sticking region around the center of the contact zone. The calculated...... size of the sticking region with varying contact length and pressure/reduction is experimentally verified by plane strain upsetting tests measuring the local surface deformation of the work pieces after unloading....

  4. Two-pass greedy regular expression parsing

    DEFF Research Database (Denmark)

    Grathwohl, Niels Bjørn Bugge; Henglein, Fritz; Nielsen, Lasse

    2013-01-01

    We present new algorithms for producing greedy parses for regular expressions (REs) in a semi-streaming fashion. Our lean-log algorithm executes in time O(mn) for REs of size m and input strings of size n and outputs a compact bit-coded parse tree representation. It improves on previous algorithms...... by: operating in only 2 passes; using only O(m) words of random-access memory (independent of n); requiring only kn bits of sequentially written and read log storage, where k ... and not requiring it to be stored at all. Previous RE parsing algorithms do not scale linearly with input size, or require substantially more log storage and employ 3 passes where the first consists of reversing the input, or do not or are not known to produce a greedy parse. The performance of our unoptimized C...

  5. Single Pass Albumin Dialysis in Hepatorenal Syndrome

    Directory of Open Access Journals (Sweden)

    Rahman Ebadur

    2008-01-01

    Full Text Available Hepatorenal syndrome (HRS is the most appalling complication of acute or chronic liver disease with 90% mortality rate. Single pass albumin dialysis (SPAD can be considered as a noble liver support technique in HRS. Here, we present a case of a young healthy patient who developed hyperacute fulminant liver failure that progressed to HRS. The patient was offered SPAD as a bridge to liver transplantation, however, it resulted in an excellent recovery.

  6. Calibrating the Shan-Chen lattice Boltzmann model for immiscible displacement in porous media

    DEFF Research Database (Denmark)

    Christensen, Britt Stenhøj Baun; Schaap, M.G.; Wildenschild, D.

    2006-01-01

    The lattice Boltzmann (LB) modeling technique is increasingly being applied in a variety of fields where computational fluid dynamics are investigated. In our field of interest, environmentally related flow processes in porous media, the use of the LB method is still not common. For the LB...

  7. Blind sensor calibration using approximate message passing

    International Nuclear Information System (INIS)

    Schülke, Christophe; Caltagirone, Francesco; Zdeborová, Lenka

    2015-01-01

    The ubiquity of approximately sparse data has led a variety of communities to take great interest in compressed sensing algorithms. Although these are very successful and well understood for linear measurements with additive noise, applying them to real data can be problematic if imperfect sensing devices introduce deviations from this ideal signal acquisition process, caused by sensor decalibration or failure. We propose a message passing algorithm called calibration approximate message passing (Cal-AMP) that can treat a variety of such sensor-induced imperfections. In addition to deriving the general form of the algorithm, we numerically investigate two particular settings. In the first, a fraction of the sensors is faulty, giving readings unrelated to the signal. In the second, sensors are decalibrated and each one introduces a different multiplicative gain to the measurements. Cal-AMP shares the scalability of approximate message passing, allowing us to treat large sized instances of these problems, and experimentally exhibits a phase transition between domains of success and failure. (paper)

  8. Double-pass quantum volume hologram

    International Nuclear Information System (INIS)

    Vasilyev, Denis V.; Sokolov, Ivan V.

    2011-01-01

    We propose a scheme for parallel, spatially multimode quantum memory for light. The scheme is based on the propagation in different directions of a quantum signal wave and strong classical reference wave, like in a classical volume hologram and the previously proposed quantum volume hologram [D. V. Vasilyev et al., Phys. Rev. A 81, 020302(R) (2010)]. The medium for the hologram consists of a spatially extended ensemble of cold spin-polarized atoms. In the absence of the collective spin rotation during the interaction, two passes of light for both storage and retrieval are required, and therefore the present scheme can be called a double-pass quantum volume hologram. The scheme is less sensitive to diffraction and therefore is capable of achieving a higher density of storage of spatial modes as compared to the previously proposed thin quantum hologram [D. V. Vasilyev et al., Phys. Rev. A 77, 020302(R) (2008)], which also requires two passes of light for both storage and retrieval. However, the present scheme allows one to achieve a good memory performance with a lower optical depth of the atomic sample as compared to the quantum volume hologram. A quantum hologram capable of storing entangled images can become an important ingredient in quantum information processing and quantum imaging.

  9. Particles at fluid-fluid interfaces: A new Navier-Stokes-Cahn-Hilliard surface- phase-field-crystal model.

    Science.gov (United States)

    Aland, Sebastian; Lowengrub, John; Voigt, Axel

    2012-10-01

    Colloid particles that are partially wetted by two immiscible fluids can become confined to fluid-fluid interfaces. At sufficiently high volume fractions, the colloids may jam and the interface may crystallize. The fluids together with the interfacial colloids form an emulsion with interesting material properties and offer an important route to new soft materials. A promising approach to simulate these emulsions was presented in Aland et al. [Phys. Fluids 23, 062103 (2011)], where a Navier-Stokes-Cahn-Hilliard model for the macroscopic two-phase fluid system was combined with a surface phase-field-crystal model for the microscopic colloidal particles along the interface. Unfortunately this model leads to spurious velocities which require very fine spatial and temporal resolutions to accurately and stably simulate. In this paper we develop an improved Navier-Stokes-Cahn-Hilliard-surface phase-field-crystal model based on the principles of mass conservation and thermodynamic consistency. To validate our approach, we derive a sharp interface model and show agreement with the improved diffuse interface model. Using simple flow configurations, we show that the new model has much better properties and does not lead to spurious velocities. Finally, we demonstrate the solid-like behavior of the crystallized interface by simulating the fall of a solid ball through a colloid-laden multiphase fluid.

  10. Fluid properties control degassing or storage of abiogenic CH4 during slab exhumation: the fluid inclusion record from the Western Alps.

    Science.gov (United States)

    Ferrando, S.; Castelli, D.; Frezzotti, M. L.

    2017-12-01

    Abiogenic CH4 can be produced by interaction between carbonates and reducing fluids derived from the hydration of ultramafics (e.g., mantle peridotite or HP Ol-serpentinite). This process occurs during slab exhumation because cooling promotes serpentinization of olivine in presence of water (Fo + H2O = Atg + Brc and the linked reactions: Fa + H2O = Fe-Atg + Mag + H2 and Atg + CaCO3 + H2 = Di + Brc + CH4 + H2O) at ca. 500-375°C (P=2.0-0.2 GPa). Experiments in the CH4-H2O-NaCl system indicate that, at these conditions, fluids are immiscible even for very low salinity (ca. 3 wt%) and that the NaCl content in the aqueous part of the fluid increases with temperature whereas the CH4 content in the gaseous part shows an opposite trend (Lamb et al., 2002; Li, 2017).In HP rodingite from the Piemonte ophiolite Zone (W Alps), primary fluid inclusions consisting of a brine (6 wt% CaCl2 + 6 wt% NaCl) with H2 + CH4 ≤ 1 mol % [CH4/(H2+CH4) = 0.37-10] occur in vesuvianite veins that formed at P=0.2 GPa and T=375°C. We interpret them as the aqueous part of an immiscible reducing fluid produced during late Alpine serpentinization of the surrounding ultramafics. Interestingly, CH4-H2 gaseous fluids are never reported in rodingite, whereas early CH4-H2O-H2±graphite and CH4-H2±graphite fluid inclusions, with variable gas-water proportions, trapped in calcite at P≤1.0 GPa and T≤450°C, are recently reported from HP "graphitized" ophicarbonate from the Lanzo peridotite Massif (W Alps; Vitale Brovarone et al., 2017).Both HP ophiolites and partially-serpentinized peridotite massifs are, thus, efficient lithologies to produce CH4 during exhumation. The amount of released CH4 depends on the amount of water available during exhumation. However, when fluids immiscibility occurs, the gaseous-rich part (CH4-H2) of the immiscible fluid produced in ultramafics likely remains confined in the slab because it is less mobile with respect to the aqueous-rich part due to its high dihedral

  11. Schroedinger fluid

    International Nuclear Information System (INIS)

    Kan, K.K.

    1983-01-01

    The relationship of nuclear internal flow and collective inertia, the difference of this flow from that of a classical fluid, and the approach of this flow to rigid flow in independent-particle model rotation are elucidated by reviewing the theory of Schroedinger fluid and its implications for collective vibration and rotation. (author)

  12. "Which pass is better?" Novel approaches to assess passing effectiveness in elite soccer.

    Science.gov (United States)

    Rein, Robert; Raabe, Dominik; Memmert, Daniel

    2017-10-01

    Passing behaviour is a key property of successful performance in team sports. Previous investigations however have mainly focused on notational measurements like total passing frequencies which provide little information about what actually constitutes successful passing behaviour. Consequently, this has hampered the transfer of research findings into applied settings. Here we present two novel approaches to assess passing effectiveness in elite soccer by evaluating their effects on majority situations and space control in front of the goal. Majority situations are assessed by calculating the number of defenders between the ball carrier and the goal. Control of space is estimated using Voronoi-diagrams based on the player's positions on the pitch. Both methods were applied to position data from 103 German First division games from the 2011/2012, 2012/2013 and 2014/2015 seasons using a big data approach. The results show that both measures are significantly related to successful game play with respect to the number of goals scored and to the probability of winning a game. The results further show that on average passes from the mid-field into the attacking area are most effective. The presented passing efficiency measures thereby offer new opportunities for future applications in soccer and other sports disciplines whilst maintaining practical relevance with respect to tactical training regimes or game performances analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. On Energy Inequality for the Problem on the Evolution of Two Fluids of Different Types Without Surface Tension

    Science.gov (United States)

    Denisova, Irina Vlad.

    2015-03-01

    The paper deals with the motion of two immiscible viscous fluids in a container, one of the fluids being compressible while another one being incompressible. The interface between the fluids is an unknown closed surface where surface tension is neglected. We assume the compressible fluid to be barotropic, the pressure being given by an arbitrary smooth increasing function. This problem is considered in anisotropic Sobolev-Slobodetskiǐ spaces. We show that the L 2-norms of the velocity and deviation of compressible fluid density from the mean value decay exponentially with respect to time. The proof is based on a local existence theorem (Denisova, Interfaces Free Bound 2:283-312, 2000) and on the idea of constructing a function of generalized energy, proposed by Padula (J Math Fluid Mech 1:62-77, 1999). In addition, we eliminate the restrictions for the viscosities which appeared in Denisova (Interfaces Free Bound 2:283-312, 2000).

  14. Silicate liquid immiscibility in magmas and in the system K2O-FeO-AI2O3-SiO2: an example of serendipity

    Science.gov (United States)

    Roedder, E.

    1978-01-01

    The concept of silicate liquid immiscibility was invoked early in the history of petrology to explain certain pairs of compositionally divergent rocks, but. as a result of papers by Greig (Am. J. Sci. 13, 1-44, 133-154) and Bowen (The Evolution of the Igneous Rocks), it fell into disfavor for many years. The discovery of immiscibility in geologically reasonable temperature ranges and compositions in experimental work on the system K2O-FeO-Al2O3-SiO2, and of evidence for immiscibility in a variety of lunar and terrestrial rocks, has reinstated the process. Phase equilibria in the high-silica corner of the tetrahedron representing the system K2O- FeO-Al2O3-SiO2 are presented, in the form of constant FeO sections through the tetrahedron, at 10% increments. Those sections, showing the tentative relationships of the primary phase volumes, are based on 5631 quenching runs on 519 compositions, made in metallic iron containers in pure nitrogen. Thirteen crystalline compounds are involved, of which at least six show two or more crystal modifica-tions. Two separate phase volumes, in each of which two immiscible liquids, one iron-rich and the other iron-poor, are present at the liquidus. One of these volumes is entirely within the quaternary system, astride the 1:1 K2O:Al2O3 plane. No quaternary compounds as such have been found, but evidence does point toward at least partial quaternary solid solution, with rapidly lowering liquidus temperatures, from K2O??Al2O3?? 2SiO2 ('potash nepheline', kalsilite. kaliophilite) to the isostructural compound K2O??FeO??3SiO2, and from K2O??Al2O3??4SiO2 (leucite) to the isostructural compound K2O??FeO??5SiO2, Both of these series apparently involve substitution, in tetrahedral coordination. of a ferrous iron and a silicon ion for two aluminum ions. Some of the 'impurities' found in analyses of the natural phases may reflect these substitutions. As a result of the geometry of the immiscibility volume located entirely within the quaternary

  15. Modeling technique for optimal recovery of immiscible light hydrocarbons as free product from contaminated aquifer

    OpenAIRE

    Cooper, Grant S., Jr.; Peralta, R. C.; Kaluarachchi, J. J.

    1993-01-01

    Contamination sites associated with light non-aqueous phase liquids {LNAPL) are numerous and represent difficult cleanup problems. Remediation methods for cleanup of LNAPL fluids in subsurface systems are continuously evolving with the development of various technologies for pump.-and~treat, soil venting, and in-situ bioremediation. Evaluating the effectiveness of remediation techniques as well as attempting to improve their efficiency has been a focus of many researchers, These efforts have ...

  16. Approximate model for calculating overall heat transfer between overlying immiscible liquid layers with bubble-induced liquid entrainment

    International Nuclear Information System (INIS)

    Greene, G.A.; Schwarz, C.E.

    1982-01-01

    In the event a commercial power reactor is subjected to a Class 9 accident resulting in gross core melting and reactor pressure vessel penetration, it has been shown that the containment integrity may subsequently be threatened by steam overpressurization, combustible gas reactions, and basemat penetration. A major contributor to these events would be the interaction of molten core debris with the structural concrete. Modeling of core-concrete interactions involves many poorly understood and complicated heat transfer phenomena for which there exists a sparse data base. One of these phenomena, which has been shown to have significant impact upon code calculations of core-concrete interactions, is the rate of heat transfer between overlying immiscible layers of core oxides and molten metals whose interface is agitated by transverse gas flow. A mathematical model is developed to analyze this heat transfer

  17. Modeling and simulations for molecular scale hydrodynamics of the moving contact line in immiscible two-phase flows

    KAUST Repository

    Qian, Tiezheng

    2009-10-29

    This paper starts with an introduction to the Onsager principle of minimum energy dissipation which governs the optimal paths of deviation and restoration to equilibrium. Then there is a review of the variational approach to moving contact line hydrodynamics. To demonstrate the validity of our continuum hydrodynamic model, numerical results from model calculations and molecular dynamics simulations are presented for immiscible Couette and Poiseuille flows past homogeneous solid surfaces, with remarkable overall agreement. Our continuum model is also used to study the contact line motion on surfaces patterned with stripes of different contact angles (i.e. surfaces of varying wettability). Continuum calculations predict the stick-slip motion for contact lines moving along these patterned surfaces, in quantitative agreement with molecular dynamics simulation results. This periodic motion is tunable through pattern period (geometry) and contrast in wetting property (chemistry). The consequence of stick-slip contact line motion on energy dissipation is discussed. © 2009 IOP Publishing Ltd.

  18. Investigation of the impact of immiscible oils on direct evaporation of ammonia; Ermittlung der Rolle von nicht-mischbaren Oelen bei der Direktverdampfung von Ammoniak

    Energy Technology Data Exchange (ETDEWEB)

    Aecherli, P.; Boyman, T.

    2004-07-01

    The direct evaporation of the refrigerant inside the tubes allows an important minimisation of the plant refrigerant charge. The present research project summarises the experimental data on the flow boiling of ammonia inside smooth horizontal tubes and the decrease of the heat transfer coefficient due to the presence of an immiscible oil. The use of ammonia in direct expansion systems is limited due to its immiscibility with the conventional lubricating oils. The immiscible oil forms a layer with a poor conductivity, thus causing a strong reduction of the heat transfer coefficient. The present work is an experimental contribution to the direct evaporation of ammonia with the frequently used synthetic oil Mobil Gargoyle Arctic SHC 326 (viscosity grade ISO-VG 68) which is immiscible with ammonia. The results of the mean heat transfer coefficient measurements during the flow boiling are summarised with a short description of the visual observations at critical stages of the in-tube boiling. The tests have been carried out with plain tubes (with 14 mm inner diameter) at evaporation saturation temperatures from -10 {sup o}C to +10 {sup o}C for mass fluxes from G=40 to 170 kg/(m{sup 2}s) with heat fluxes from q{sub dot}=10 to 50 kW/m{sup 2}. Experiments run with a frequently used immiscible synthetic oil without any oil injection and then with oil contents from 0.1 to 3.5% (by weight) showed a significant decrease of the flow boiling heat transfer coefficient mainly at high mass fluxes. The decrease of the heat transfer coefficient is more significant in the sector of the evaporator where boiling with annular flow pattern occurs. (author)

  19. Pass-transistor asynchronous sequential circuits

    Science.gov (United States)

    Whitaker, Sterling R.; Maki, Gary K.

    1989-01-01

    Design methods for asynchronous sequential pass-transistor circuits, which result in circuits that are hazard- and critical-race-free and which have added degrees of freedom for the input signals, are discussed. The design procedures are straightforward and easy to implement. Two single-transition-time state assignment methods are presented, and hardware bounds for each are established. A surprising result is that the hardware realizations for each next state variable and output variable is identical for a given flow table. Thus, a state machine with N states and M outputs can be constructed using a single layout replicated N + M times.

  20. Compatibility of manufacturing process fluids with R-134a and polyolester lubricant. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Cavestri, R.C.; Schooley, D.L. [Imagination Resources, Inc., Dublin, OH (United States)

    1996-07-01

    This report includes a broad list of processing fluids that are known to be used to manufacture air conditioning and refrigeration products. Sixty-four process fluids from this list were selected for compatibility studies with R-134a and ICI EMKARATE RL32H (32 ISO) polyolester lubricant. Solutions or suspensions of the process fluid residues in polyolester lubricant were heated for 14 days at 175{degrees}C (347{degrees}F) in evacuated sealed glass tubes containing only valve steel coupons. Miscibility tests were performed at 90 wt.% R-134a, 10 wt.% polyolester lubricant with process fluid residue contaminate and were scanned in 10{degrees}C (18{degrees}F) increments over a temperature range of ambient to -40{degrees}C (-40{degrees}F). Any sign of turbidity, haze formation or oil separation was considered the immiscibility point.

  1. Fabrication of seamless calandria tubes by cold pilgering route using 3-pass and 2-pass schedules

    Science.gov (United States)

    Saibaba, N.

    2008-12-01

    Calandria tube is a large diameter, extremely thin walled zirconium alloy tube which has diameter to wall thickness ratio as high as 90-95. Such tubes are conventionally produced by the 'welded route', which involves extrusion of slabs followed by a series of hot and cold rolling passes, intermediate anneals, press forming of sheets into circular shape and closing the gap by TIG welding. Though pilgering is a well established process for the fabrication of seamless tubes, production of extremely thin walled tubes offers several challenges during pilgering. Nuclear fuel complex (NFC), Hyderabad, has successfully developed a process for the production of Zircaloy-4 calandria tubes by adopting the 'seamless route' which involves hot extrusion of mother blanks followed by three-pass pilgering or two-pass pilgering schedules. This paper deals with standardization of the seamless route processes for fabrication of calandria tubes, comparison between the tubes produced by 2-pass and 3-pass pilgering schedules, role of ultrasonic test charts for control of process parameters, development of new testing methods for burst testing and other properties.

  2. Fabrication of seamless calandria tubes by cold pilgering route using 3-pass and 2-pass schedules

    International Nuclear Information System (INIS)

    Saibaba, N.

    2008-01-01

    Calandria tube is a large diameter, extremely thin walled zirconium alloy tube which has diameter to wall thickness ratio as high as 90-95. Such tubes are conventionally produced by the 'welded route', which involves extrusion of slabs followed by a series of hot and cold rolling passes, intermediate anneals, press forming of sheets into circular shape and closing the gap by TIG welding. Though pilgering is a well established process for the fabrication of seamless tubes, production of extremely thin walled tubes offers several challenges during pilgering. Nuclear fuel complex (NFC), Hyderabad, has successfully developed a process for the production of Zircaloy-4 calandria tubes by adopting the 'seamless route' which involves hot extrusion of mother blanks followed by three-pass pilgering or two-pass pilgering schedules. This paper deals with standardization of the seamless route processes for fabrication of calandria tubes, comparison between the tubes produced by 2-pass and 3-pass pilgering schedules, role of ultrasonic test charts for control of process parameters, development of new testing methods for burst testing and other properties

  3. A free-surface lattice Boltzmann method for modelling the filling of expanding cavities by Bingham fluids.

    Science.gov (United States)

    Ginzburg, Irina; Steiner, Konrad

    2002-03-15

    The filling process of viscoplastic metal alloys and plastics in expanding cavities is modelled using the lattice Boltzmann method in two and three dimensions. These models combine the regularized Bingham model for viscoplastic fluids with a free-interface algorithm. The latter is based on a modified immiscible lattice Boltzmann model in which one species is the fluid and the other one is considered to be a vacuum. The boundary conditions at the curved liquid-vacuum interface are met without any geometrical front reconstruction from a first-order Chapman-Enskog expansion. The numerical results obtained with these models are found in good agreement with available theoretical and numerical analysis.

  4. Common pass decentered annular ring resonator

    Energy Technology Data Exchange (ETDEWEB)

    Holmes, D. A.; Waite, T. R.

    1985-04-30

    An optical resonator having an annular cylindrical gain region for use in a chemical laser or the like in which two ring-shaped mirrors having substantially conical reflecting surfaces are spaced apart along a common axis of revolution of the respective conical surfaces. A central conical mirror reflects incident light directed along said axis radially outwardly to the reflecting surface of a first one of the ring-shaped mirrors. The radial light rays are reflected by the first ring mirror to the second ring mirror within an annular cylindrical volume concentric with said common axis and forming a gain region. Light rays impinging on the second ring mirror are reflected to diametrically opposite points on the same conical mirror surfaces and back to the first ring mirror through the same annular cylindrical volume. The return rays are then reflected by the conical mirror surface of the first ring mirror back to the central conical mirror. The mirror surfaces are angled such that the return rays are reflected back along the common axis by the central mirror in a concentric annular cylindrical volume. A scraper mirror having a central opening centered on said axis and an offset opening reflects all but the rays passing through the two openings in an output beam. The rays passing through the second opening are reflected back through the first opening to provide feedback.

  5. Comparison of cryogenic low-pass filters

    Science.gov (United States)

    Thalmann, M.; Pernau, H.-F.; Strunk, C.; Scheer, E.; Pietsch, T.

    2017-11-01

    Low-temperature electronic transport measurements with high energy resolution require both effective low-pass filtering of high-frequency input noise and an optimized thermalization of the electronic system of the experiment. In recent years, elaborate filter designs have been developed for cryogenic low-level measurements, driven by the growing interest in fundamental quantum-physical phenomena at energy scales corresponding to temperatures in the few millikelvin regime. However, a single filter concept is often insufficient to thermalize the electronic system to the cryogenic bath and eliminate spurious high frequency noise. Moreover, the available concepts often provide inadequate filtering to operate at temperatures below 10 mK, which are routinely available now in dilution cryogenic systems. Herein we provide a comprehensive analysis of commonly used filter types, introduce a novel compact filter type based on ferrite compounds optimized for the frequency range above 20 GHz, and develop an improved filtering scheme providing adaptable broad-band low-pass characteristic for cryogenic low-level and quantum measurement applications at temperatures down to few millikelvin.

  6. Comparison of cryogenic low-pass filters.

    Science.gov (United States)

    Thalmann, M; Pernau, H-F; Strunk, C; Scheer, E; Pietsch, T

    2017-11-01

    Low-temperature electronic transport measurements with high energy resolution require both effective low-pass filtering of high-frequency input noise and an optimized thermalization of the electronic system of the experiment. In recent years, elaborate filter designs have been developed for cryogenic low-level measurements, driven by the growing interest in fundamental quantum-physical phenomena at energy scales corresponding to temperatures in the few millikelvin regime. However, a single filter concept is often insufficient to thermalize the electronic system to the cryogenic bath and eliminate spurious high frequency noise. Moreover, the available concepts often provide inadequate filtering to operate at temperatures below 10 mK, which are routinely available now in dilution cryogenic systems. Herein we provide a comprehensive analysis of commonly used filter types, introduce a novel compact filter type based on ferrite compounds optimized for the frequency range above 20 GHz, and develop an improved filtering scheme providing adaptable broad-band low-pass characteristic for cryogenic low-level and quantum measurement applications at temperatures down to few millikelvin.

  7. Fluid dynamics

    CERN Document Server

    Bernard, Peter S

    2015-01-01

    This book presents a focused, readable account of the principal physical and mathematical ideas at the heart of fluid dynamics. Graduate students in engineering, applied math, and physics who are taking their first graduate course in fluids will find this book invaluable in providing the background in physics and mathematics necessary to pursue advanced study. The book includes a detailed derivation of the Navier-Stokes and energy equations, followed by many examples of their use in studying the dynamics of fluid flows. Modern tensor analysis is used to simplify the mathematical derivations, thus allowing a clearer view of the physics. Peter Bernard also covers the motivation behind many fundamental concepts such as Bernoulli's equation and the stream function. Many exercises are designed with a view toward using MATLAB or its equivalent to simplify and extend the analysis of fluid motion including developing flow simulations based on techniques described in the book.

  8. An experimental evaluation of multi-pass solar air heaters

    Energy Technology Data Exchange (ETDEWEB)

    Satcunanathan, S.; Persad, P.

    1980-12-01

    Three collectors of identical dimensions but operating in the single-pass, two-pass and three-pass modes were tested simultaneously under ambient conditions. It was found that the two-pass air heater was consistently better than the single-pass air heater over the day for the range of mass flow rates considered. It was also found that at a mass flow rate of 0.0095 kg s/sup -1/ m/sup -2/, the thermal performances of the two-pass and three-pass collectors were identical, but at higher flow rates the two-pass collector was superior to the three-pass collector, the superiority decreasing with increasing mass flow rate.

  9. 3D characterization of a Great Basin geothermal system: Astor Pass, NV

    Science.gov (United States)

    Siler, D. L.; Mayhew, B.; Faulds, J. E.

    2012-12-01

    The Great Basin exhibits both anomalously high heat flow (~75±5 mWm-2) and active faulting and extension resulting in robust geothermal activity. There are ~430 known geothermal systems in the Great Basin, with evidence suggesting that undiscovered blind geothermal systems may actually represent the majority of geothermal activity. These systems employ discrete fault intersection/interaction areas as conduits for geothermal circulation. Recent studies show that steeply dipping normal faults with step-overs, fault intersections, accommodation zones, horse-tailing fault terminations and transtensional pull-aparts are the most prominent structural controls of Great Basin geothermal systems. These fault geometries produce sub-vertical zones of high fault and fracture density that act as fluid flow conduits. Structurally controlled fluid flow conduits are further enhanced when critically stressed with respect to the ambient stress conditions. The Astor Pass blind geothermal system, northwestern Nevada, lies along the boundary between the Basin and Range to the east and the Walker Lane to the west. Along this boundary, strain is transferred from dextral shear in the Walker Lane to west-northwest directed extension in the Basin and Range. As such, the Astor Pass area lies in a transtensional setting consisting of both northwest-striking, left-stepping dextral faults and more northerly striking normal faults. The Astor Pass tufa tower implies the presence of a blind geothermal system. Previous studies suggest that deposition of the Astor Pass tufa was controlled by the intersection of a northwest-striking dextral normal fault and north-northwest striking normal fault. Subsequent drilling (to ~1200 m) has revealed fluid temperatures of ~94°C, confirming the presence of a blind geothermal system at Astor Pass. Expanding upon previous work and employing additional detailed geologic mapping, interpretation of 2D seismic reflection data and analysis of well cuttings, a 3

  10. The Pension Fund passes important milestones

    CERN Document Server

    2012-01-01

    In this column, the Chairman of the Pension Fund Governing Board (PFGB) presents the Board's latest main decisions, initiatives and accomplishments to the Fund's members and beneficiaries.   Since my last report in October, the PFGB has passed several milestones in actuarial, technical and investment matters. The PFGB has completed an analysis of a request by the European Organisation for Astronomical Research in the Southern Hemisphere (ESO) to reduce the increased cost of pension insurance for new ESO recruits that has been caused by the increased CHF/€ exchange ratio. Currently the staff of ESO are admitted to the CERN Pension Fund, pursuant to a co-operation agreement between CERN and ESO dating back to 1968. This analysis assessed the actuarial, financial, administrative and legal implications, and is scheduled to be presented to the CERN Council and the Finance Committee in December. After an open tendering process the PFGB has selected Buck Consultants Limited...

  11. The baton passes to the LHC

    CERN Multimedia

    CERN Bulletin

    2011-01-01

    Held in the picturesque mountain setting of La Thuile in the Italian Alps, the international conference “Rencontres de Moriond” showed how the baton of discovery in the field of high-energy physics is definitely passing to the LHC experiments. In the well-known spirit of Moriond, the conference was an important platform for young students to present their latest results. The Higgs boson might well be within reach this year and the jet-quenching phenomenon might reveal new things soon…   New physics discussed over the Italian Alps during the "Les rencontres de Moriond" conference.  (Photographer: Paul Gerritsen. Adapted by Katarina Anthony) Known by physicists as one of the most important winter conferences, “Les rencontres de Moriond” are actually a series of conferences spread over two weeks covering the main themes of electroweak interactions, QCD and high-energy interactions, cosmology, gravitation, astropar...

  12. Fluid Dynamics And Mass Transfer In Two-Fluid Taylor-Couette Flow

    International Nuclear Information System (INIS)

    Baier, G.; Graham, M.D.

    1998-01-01

    The Taylor-Couette instability of a single liquid phase can be used to enhance mass transfer processes such as filtration and membrane separations. We consider here the possibility of using this instability to enhance interphase transport in a two-fluid systems, with a view toward improved liquid-liquid extractions for biotechnology applications. We investigate the centrifugal instability of a pair of radially stratified immiscible liquids in the annular gap between concentric, corotating cylinders: two-fluid Taylor-Couette flow. Experiments show that a two-layer flow with a well-defined interface and Taylor vortices in each phase can be obtained. The experimental results are in good agreement with predictions of inviscid arguments based on a two-phase extension of Rayleigh's criterion, as well as with detailed linear stability calculations. For a given geometry, the most stable configuration occurs for fluids of roughly (exactly in the inviscid limit) equal dynamic viscosities. A number of preliminary mass transfer experiments have also been performed, in the presence of axial counterflow. The onset of Taylor vortices coincides with a clear decrease in the extent of axial dispersion and an increase in the rate of interphase transport, thus suggesting that this flow geometry may provide an effective means for countercurrent chromatographic separations

  13. Retail Bank Interest Rate Pass-Through; Is Chile Atypical?

    OpenAIRE

    Alessandro Rebucci; Marco A Espinosa-Vega

    2003-01-01

    This paper investigates empirically the pass-through of money market interest rates to retail banking interest rates in Chile, the United States, Canada, Australia, New Zealand, and five European countries. Overall, Chile's pass-through does not appear atypical. Based on a standard error-correction model, we find that, as in most countries considered, Chile's measured pass-through is incomplete. But Chile's pass-through is also faster than in many other countries considered and is comparable ...

  14. Three-dimensional lattice Boltzmann model for immiscible two-phase flow simulations.

    Science.gov (United States)

    Liu, Haihu; Valocchi, Albert J; Kang, Qinjun

    2012-04-01

    We present an improved three-dimensional 19-velocity lattice Boltzmann model for immisicible binary fluids with variable viscosity and density ratios. This model uses a perturbation step to generate the interfacial tension and a recoloring step to promote phase segregation and maintain surfaces. A generalized perturbation operator is derived using the concept of a continuum surface force together with the constraints of mass and momentum conservation. A theoretical expression for the interfacial tension is determined directly without any additional analysis and assumptions. The recoloring algorithm proposed by Latva-Kokko and Rothman is applied for phase segregation, which minimizes the spurious velocities and removes lattice pinning. This model is first validated against the Laplace law for a stationary bubble. It is found that the interfacial tension is predicted well for density ratios up to 1000. The model is then used to simulate droplet deformation and breakup in simple shear flow. We compute droplet deformation at small capillary numbers in the Stokes regime and find excellent agreement with the theoretical Taylor relation for the segregation parameter β=0.7. In the limit of creeping flow, droplet breakup occurs at a critical capillary number 0.35fluids for a wide range of Eötvös and Morton numbers. Numerical results are compared with theoretical predictions and experimental results, and satisfactory agreement is shown.

  15. Vortex-induced morphology on a two-fluid interface and the transitions.

    Science.gov (United States)

    Tsai, J-C; Tao, C-Y; Sun, Y-C; Lai, C-Y; Huang, K-H; Juan, W-T; Huang, J-R

    2015-09-01

    We investigate experimentally the steady flows in a cylinder containing two immiscible liquids, with the primary fluid being driven by the upper boundary rotating at constant speeds. The system exhibits interesting interplays between the flow fields and the morphology of the interface, with evidence showing that the remarkable flattop structure is a consequence of the vortex breakdown discovered decades ago, and that the deformability of the interface also feedbacks positively to the development of the vortices. Monitoring the topological structure of the flow fields defines the base states and transitions behind the morphology, whereas our survey over different aspect ratios also reveals rich phenomena of surface instabilities accompanying these steady states.

  16. 36 CFR 13.918 - Sable Pass Wildlife Viewing Area.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Sable Pass Wildlife Viewing... Preserve General Provisions § 13.918 Sable Pass Wildlife Viewing Area. (a) Entry into the Sable Pass Wildlife Viewing Area is prohibited from May 1 to September 30 unless authorized by the Superintendent. (b...

  17. PASS Student Leader and Mentor Roles: A Tertiary Leadership Pathway

    Science.gov (United States)

    Skalicky, Jane; Caney, Annaliese

    2010-01-01

    In relation to developing leadership skills during tertiary studies, this paper considers the leadership pathway afforded by a Peer Assisted Study Sessions (PASS) program which includes the traditional PASS Leader role and a more senior PASS Mentor role. Data was collected using a structured survey with open-ended questions designed to capture the…

  18. Fluid Shifts

    Science.gov (United States)

    Stenger, M. B.; Hargens, A. R.; Dulchavsky, S. A.; Arbeille, P.; Danielson, R. W.; Ebert, D. J.; Garcia, K. M.; Johnston, S. L.; Laurie, S. S.; Lee, S. M. C.; hide

    2017-01-01

    Introduction. NASA's Human Research Program is focused on addressing health risks associated with long-duration missions on the International Space Station (ISS) and future exploration-class missions beyond low Earth orbit. Visual acuity changes observed after short-duration missions were largely transient, but now more than 50 percent of ISS astronauts have experienced more profound, chronic changes with objective structural findings such as optic disc edema, globe flattening and choroidal folds. These structural and functional changes are referred to as the visual impairment and intracranial pressure (VIIP) syndrome. Development of VIIP symptoms may be related to elevated intracranial pressure (ICP) secondary to spaceflight-induced cephalad fluid shifts, but this hypothesis has not been tested. The purpose of this study is to characterize fluid distribution and compartmentalization associated with long-duration spaceflight and to determine if a relation exists with vision changes and other elements of the VIIP syndrome. We also seek to determine whether the magnitude of fluid shifts during spaceflight, as well as any VIIP-related effects of those shifts, are predicted by the crewmember's pre-flight status and responses to acute hemodynamic manipulations, specifically posture changes and lower body negative pressure. Methods. We will examine a variety of physiologic variables in 10 long-duration ISS crewmembers using the test conditions and timeline presented in the figure below. Measures include: (1) fluid compartmentalization (total body water by D2O, extracellular fluid by NaBr, intracellular fluid by calculation, plasma volume by CO rebreathe, interstitial fluid by calculation); (2) forehead/eyelids, tibia, and calcaneus tissue thickness (by ultrasound); (3) vascular dimensions by ultrasound (jugular veins, cerebral and carotid arteries, vertebral arteries and veins, portal vein); (4) vascular dynamics by MRI (head/neck blood flow, cerebrospinal fluid

  19. Method and apparatus for injecting fluid

    Energy Technology Data Exchange (ETDEWEB)

    Hyde, W E

    1966-07-05

    A method and apparatus are described for injecting grouting material into porous, fractured, unconsolidated, or other formations, whose cohesion is to be increased and/or whose permeability is to be decreased. A tool for injecting the fluid consists of a packer and valves through which the pressurized fluid may pass from the interior of the tool to the packer to expand it. Another valve allows pressure fluid to be vented so as to allow contraction of the packer. A third valve allows a flow of pressurized flow out of the tool and into the material when a predetermined pressure within the tool has been attained. (9 claims)

  20. Astor Pass Seismic Surveys Preliminary Report

    Energy Technology Data Exchange (ETDEWEB)

    Louie, John [UNR; Pullammanappallil, Satish [Optim; Faulds, James; Eisses, Amy; Kell, Annie; Frary, Roxanna; Kent, Graham

    2011-08-05

    In collaboration with the Pyramid Lake Paiute Tribe (PLPT), the University of Nevada, Reno (UNR) and Optim re-processed, or collected and processed, over 24 miles of 2d seismic-reflection data near the northwest corner of Pyramid Lake, Nevada. The network of 2d land surveys achieved a near-3d density at the Astor Pass geothermal prospect that the PLPT drilled during Nov. 2010 to Feb. 2011. The Bureau of Indian Affairs funded additional seismic work around the Lake, and an extensive, detailed single-channel marine survey producing more than 300 miles of section, imaging more than 120 ft below the Lake bottom. Optim’s land data collection utilized multiple heavy vibrators and recorded over 200 channels live, providing a state-of-the-art reflection-refraction data set. After advanced seismic analysis including first-arrival velocity optimization and prestack depth migration, the 2d sections show clear fault-plane reflections, in some areas as deep as 4000 ft, tying to distinct terminations of the mostly volcanic stratigraphy. Some lines achieved velocity control to 3000 ft depth; all lines show reflections and terminations to 5000 ft depth. Three separate sets of normal faults appear in an initial interpretation of fault reflections and stratigraphic terminations, after loading the data into the OpendTect 3d seismic visualization system. Each preliminary fault set includes a continuous trace more than 3000 ft long, and a swarm of short fault strands. The three preliminary normal-fault sets strike northerly with westward dip, northwesterly with northeast dip, and easterly with north dip. An intersection of all three fault systems documented in the seismic sections at the end of Phase I helped to locate the APS-2 and APS-3 slimholes. The seismic sections do not show the faults connected to the Astor Pass tufa spire, suggesting that we have imaged mostly Tertiary-aged faults. We hypothesize that the Recent, active faults that produced the tufa through hotspring

  1. Fluid mechanics

    International Nuclear Information System (INIS)

    Granger, R.A.

    1985-01-01

    This text offers the most comprehensive approach available to fluid mechanics. The author takes great care to insure a physical understanding of concepts grounded in applied mathematics. The presentation of theory is followed by engineering applications, helping students develop problem-solving skills from the perspective of a professional engineer. Extensive use of detailed examples reinforces the understanding of theoretical concepts

  2. Analysis of Biomechanical Structure and Passing Techniques in Basketball

    OpenAIRE

    Ricardo E. Izzo; Luca Russo

    2011-01-01

    The basketball is a complex sport, which these days has become increasingly linked to its’ psychophysical aspects rather than to the technical ones. Therefore, it is important to make a through study of the passing techniques from the point of view of the type of the pass and its’ biomechanics. From the point of view of the type of the used passes, the most used is the two-handed chest pass with a frequency of 39.9%. This is followed, in terms of frequency, by one-handed passes – the baseball...

  3. Nanomechanical characterization by double-pass force-distance mapping

    Energy Technology Data Exchange (ETDEWEB)

    Dagdas, Yavuz S; Tekinay, Ayse B; Guler, Mustafa O; Dana, Aykutlu [UNAM Institute of Materials Science and Nanotechnology, Bilkent University, 06800 Ankara (Turkey); Necip Aslan, M, E-mail: aykutlu@unam.bilkent.edu.tr [Department of Physics, Istanbul Technical University, Istanbul (Turkey)

    2011-07-22

    We demonstrate high speed force-distance mapping using a double-pass scheme. The topography is measured in tapping mode in the first pass and this information is used in the second pass to move the tip over the sample. In the second pass, the cantilever dither signal is turned off and the sample is vibrated. Rapid (few kHz frequency) force-distance curves can be recorded with small peak interaction force, and can be processed into an image. Such a double-pass measurement eliminates the need for feedback during force-distance measurements. The method is demonstrated on self-assembled peptidic nanofibers.

  4. Nanomechanical characterization by double-pass force-distance mapping

    International Nuclear Information System (INIS)

    Dagdas, Yavuz S; Tekinay, Ayse B; Guler, Mustafa O; Dana, Aykutlu; Necip Aslan, M

    2011-01-01

    We demonstrate high speed force-distance mapping using a double-pass scheme. The topography is measured in tapping mode in the first pass and this information is used in the second pass to move the tip over the sample. In the second pass, the cantilever dither signal is turned off and the sample is vibrated. Rapid (few kHz frequency) force-distance curves can be recorded with small peak interaction force, and can be processed into an image. Such a double-pass measurement eliminates the need for feedback during force-distance measurements. The method is demonstrated on self-assembled peptidic nanofibers.

  5. Anon-Pass: Practical Anonymous Subscriptions.

    Science.gov (United States)

    Lee, Michael Z; Dunn, Alan M; Katz, Jonathan; Waters, Brent; Witchel, Emmett

    2013-12-31

    We present the design, security proof, and implementation of an anonymous subscription service. Users register for the service by providing some form of identity, which might or might not be linked to a real-world identity such as a credit card, a web login, or a public key. A user logs on to the system by presenting a credential derived from information received at registration. Each credential allows only a single login in any authentication window, or epoch . Logins are anonymous in the sense that the service cannot distinguish which user is logging in any better than random guessing. This implies unlinkability of a user across different logins. We find that a central tension in an anonymous subscription service is the service provider's desire for a long epoch (to reduce server-side computation) versus users' desire for a short epoch (so they can repeatedly "re-anonymize" their sessions). We balance this tension by having short epochs, but adding an efficient operation for clients who do not need unlinkability to cheaply re-authenticate themselves for the next time period. We measure performance of a research prototype of our protocol that allows an independent service to offer anonymous access to existing services. We implement a music service, an Android-based subway-pass application, and a web proxy, and show that adding anonymity adds minimal client latency and only requires 33 KB of server memory per active user.

  6. Distributed Programming via Safe Closure Passing

    Directory of Open Access Journals (Sweden)

    Philipp Haller

    2016-02-01

    Full Text Available Programming systems incorporating aspects of functional programming, e.g., higher-order functions, are becoming increasingly popular for large-scale distributed programming. New frameworks such as Apache Spark leverage functional techniques to provide high-level, declarative APIs for in-memory data analytics, often outperforming traditional "big data" frameworks like Hadoop MapReduce. However, widely-used programming models remain rather ad-hoc; aspects such as implementation trade-offs, static typing, and semantics are not yet well-understood. We present a new asynchronous programming model that has at its core several principles facilitating functional processing of distributed data. The emphasis of our model is on simplicity, performance, and expressiveness. The primary means of communication is by passing functions (closures to distributed, immutable data. To ensure safe and efficient distribution of closures, our model leverages both syntactic and type-based restrictions. We report on a prototype implementation in Scala. Finally, we present preliminary experimental results evaluating the performance impact of a static, type-based optimization of serialization.

  7. How My Program Passed the Turing Test

    Science.gov (United States)

    Humphrys, Mark

    In 1989, the author put an ELIZA-like chatbot on the Internet. The conversations this program had can be seen - depending on how one defines the rules (and how seriously one takes the idea of the test itself) - as a passing of the Turing Test. This is the first time this event has been properly written. This chatbot succeeded due to profanity, relentless aggression, prurient queries about the user, and implying that they were a liar when they responded. The element of surprise was also crucial. Most chatbots exist in an environment where people expectto find some bots among the humans. Not this one. What was also novel was the onlineelement. This was certainly one of the first AI programs online. It seems to have been the first (a) AI real-time chat program, which (b) had the element of surprise, and (c) was on the Internet. We conclude with some speculation that the future of all of AI is on the Internet, and a description of the "World- Wide-Mind" project that aims to bring this about.

  8. Notes on basis band-pass circuits; Notes sur les circuits de base passe-bande

    Energy Technology Data Exchange (ETDEWEB)

    Ailloud, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1959-07-01

    Resistor load amplifier stages, basic band-pass RC networks, conventional single-tuned circuits, have the same transfer function. Common properties and differences because diverse magnitude of parameters with proposed problems are exposed. Next the case of several cascaded stages (or networks) is examined when there is no reaction ones to another. (author) [French] Les etages amplificateurs a resistances, les circuits passe-bande RC elementaires, le circuit resonnant classique possedent la meme fonction de transfert. On fait ressortir les proprietes communes et les differences de comportement dues aux ordres de grandeur qu'il est possible de donner aux parametres en fonction des problemes a resoudre. On examine ensuite le cas de plusieurs etages (ou de plusieurs circuits) en cascade lorsqu'ils ne reagissent pas les uns sur les autres. (auteur)

  9. Carbon-based nanomaterial synthesis using nanosecond electrical discharges in immiscible layered liquids: n-heptane and water

    Science.gov (United States)

    Hamdan, Ahmad; Cha, Min Suk

    2018-06-01

    Plasmas in- or in-contact with liquids have been extensively investigated due to their high potential for a wide range of applications including, but not limited to, water treatment, material synthesis and functionalization, bio-medical applications, and liquid fuel reformation. Recently, we successfully developed a discharge using two immiscible liquids, having very different electrical permittivities, which could significantly intensify the electric field intensity. Here, we establish nanosecond discharges at the interface n-heptane-water (with respective relative dielectric permittivities of 2 and 80) to enable the synthesis of carbon-based nanomaterials. A characterization of the as-synthesized material and the annealed (500 °C) material, using various techniques (Fourier-transform, infra-red, scanning and transmission electron microscopes, etc), shows that the as-synthesized material is a mixture of two carbon-based phases: a crystalline phase (graphite like) embedded into a phase of hydrogenated amorphous carbon. The existence of two-phases may be explained by the non-homogeneity of the discharge that induces various chemical reactions in the plasma channel.

  10. Carbon-based nanomaterial synthesis using nanosecond electrical discharges in immiscible layered liquids: n-heptane and water

    KAUST Repository

    Hamdan, Ahmad

    2018-05-14

    Plasmas in- or in-contact with liquids have been extensively investigated due to their high potential for a wide range of applications including but not limited to, water treatment, material synthesis and functionalization, bio-medical applications, and liquid fuel reformation. Recently, we successfully developed a discharge using two immiscible liquids, having very different electrical permittivities, which could significantly intensify the electric field intensity. Here, we establish nanosecond discharges at the interface n-heptane-water (with respective relative dielectric permittivities of 2 and 80) to enable the synthesis of carbon-based nanomaterials. A characterization of the as-synthesized material and the annealed (500 °C) material, using various techniques (Fourier-Transform, Infra-Red, Scanning and Transmission electron microscopes, etc.), shows that the as-synthesized material is a mixture of two carbon-based phases: a crystalline phase (graphite like) embedded into a phase of hydrogenated amorphous carbon. The existence of two-phases may be explained by the non-homogeneity of the discharge that induces various chemical reactions in the plasma channel.

  11. New field of actinides solution chemistry; electrochemical study on actinide ion transfer at the interface of two immiscible electrolyte solutions

    Energy Technology Data Exchange (ETDEWEB)

    Kitatsuji, Yoshihiro; Yoshida, Zenko [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Kudo, Hiroshi [Tohoku Univ., Graduate School of Science, Sendai, Miyagi (Japan); Kihara, Sorin [Kyoto Inst. of Technolgy, Dept. of Chemistry, Kyoto (Japan)

    2002-04-01

    A novel electrochemical method on the basis of a controlled electrolysis has been developed for the study of the ion transfer at the interface of two immiscible electrolyte solutions (ITIES). The controlled-potential electrolysis for ITIES (CPEITIES) was applied to the transfer of actinide ions, and Gibbs energies for the transfer of UO{sub 2}{sup 2+} and Am{sup 3+} from aqueous solution (w) to nitrobenzene solution (nb) were determined to be 71.7 and 113 kJ mol{sup -1}, respectively. The ion transfer potentials for the facilitated transfer of UO{sub 2{sup +}} and Am{sup 3+} from w to nb in the presence of bis(diphenylphosphoryl)methane were determined, from which the stability constants of UO{sub 2}(BDPPM){sub 3}{sup 2+} and Am(BDPPM){sub 3}{sup 3+} complexes involved in the facilitated ion transfer reaction, were calculated to be 10{sup 23.9} and 10{sup 27.5}, respectively. On the basis of the results of CPEITIES, a feasibility of a new separation method, i.e., an electrolytic ion transfer separation, of actinide ions is evaluated. (author)

  12. Sol-Gel synthesis of MgO-SiO2 glass compositions having stable liquid-liquid immiscibility

    Science.gov (United States)

    Bansal, Narottam P.

    1987-01-01

    MgO-SiO2 glasses containing up to 15 mol % MgO, which could not have been prepared by the conventional glass melting method due to the presence of stable liquid-liquid immiscibility, were synthesized by the sol-gel technique. Clear and transparent gels were obtained from the hydrolysis and polycondensation of silicon tetraethoxide (TEOS) and magnesium nitrate hexahydrate when the water/TEOS mole ratio was four or more. The gelling time decreased with increase in magnesium content, water/TEOS ratio, and reaction temperature. Magnesium nitrate hexahydrate crystallized out of the gels containing 15 and 20 mol % MgO on slow drying. This problem was partially alleviated by drying the gels quickly at higher temperatures. Monolithic gel samples were prepared using glycerol as the drying control additive. The gels were subjected to various thermal treatments and characterized by several methods. No organic groups could be detected in the glasses after heat treatments to approx. 800 C, but trace amounts of hydroxyl groups were still present. No crystalline phase was found from X-ray diffraction in the gel samples to approx. 890 C. At higher temperatures, alpha quartz precipitated out as the crystalline phase in gels containing up to 10 mol % MgO. The overall activation energy for gel formation in 10MgO-90SiO2 (mol %) system for water/TEOS mole ratio of 7.5 was calculated to be 58.7 kJ/mol.

  13. Fluid dynamics of dilatant fluid

    DEFF Research Database (Denmark)

    Nakanishi, Hiizu; Nagahiro, Shin-ichiro; Mitarai, Namiko

    2012-01-01

    of the state variable, we demonstrate that the model can describe basic features of the dilatant fluid such as the stress-shear rate curve that represents discontinuous severe shear thickening, hysteresis upon changing shear rate, and instantaneous hardening upon external impact. An analysis of the model...

  14. Portsmouth Atmospheric Science School (PASS) Project

    Science.gov (United States)

    Coleman, Clarence D.; Hathaway, Roger (Technical Monitor)

    2002-01-01

    The Portsmouth Atmospheric Science School Project (PASS) Project was granted a one-year no cost extension for 2001-2002. In year three of the project, objectives and strategies were modified based on the previous year-end evaluation. The recommendations were incorporated and the program was replicated within most of the remaining elementary schools in Portsmouth, Virginia and continued in the four middle schools. The Portsmouth Atmospheric Science School Project is a partnership, which includes Norfolk State University, Cooperating Hampton Roads Organizations for Minorities in Engineering (CHROME), NASA Langley Research Center, and the City of Portsmouth, Virginia Public Schools. The project seeks to strengthen the knowledge of Portsmouth Public Schools students in the field of atmospheric sciences and enhance teacher awareness of hands on activities in the atmospheric sciences. The project specifically seeks to: 1) increase the interest and participation of elementary and middle school students in science and mathematics; 2) strengthen existing science programs; and 3) facilitate greater achievement in core subjects, which are necessary for math, science, and technical careers. Emphasis was placed on providing training activities, materials and resources for elementary students (grades 3 - 5) and middle school students (grades 6 - 8), and teachers through a CHROME club structure. The first year of the project focused on introducing elementary students to concepts and activities in atmospheric science. Year two of the project built on the first year's activities and utilizes advanced topics and activities appropriate for middle school students. During the third year of the project, in addition to the approaches used in years one and two, emphasis was placed on activities that enhanced the Virginia Standards of Learning (SOL).

  15. Physics, mathematics and numerics of particle adsorption on fluid interfaces

    Science.gov (United States)

    Schmuck, Markus; Pavliotis, Grigorios A.; Kalliadasis, Serafim

    2012-11-01

    We study two arbitrary immiscible fuids where one phase contains small particles of the size of the interface and smaller. We primarily focus on charge-free particles with wetting characteristics described by the contact angle formed at the interface between the two phases and the particles. Based on the experimental observation that particles are adsorbed on the interface to reduce the interfacial energy and hence the surface tension as well, we formulate a free-energy functional that accounts for these physical effects. Using elements from calculus of variations and formal gradient flow theory, we derive partial differential equations describing the location of the interface and the density of the particles in the fluid phases. Via numerical experiments we analyse the time evolution of the surface tension, the particle concentration, and the free energy over time and reflect basic experimentally observed phenomena.

  16. Fluid dynamics

    CERN Document Server

    Ruban, Anatoly I

    This is the first book in a four-part series designed to give a comprehensive and coherent description of Fluid Dynamics, starting with chapters on classical theory suitable for an introductory undergraduate lecture course, and then progressing through more advanced material up to the level of modern research in the field. The present Part 1 consists of four chapters. Chapter 1 begins with a discussion of Continuum Hypothesis, which is followed by an introduction to macroscopic functions, the velocity vector, pressure, density, and enthalpy. We then analyse the forces acting inside a fluid, and deduce the Navier-Stokes equations for incompressible and compressible fluids in Cartesian and curvilinear coordinates. In Chapter 2 we study the properties of a number of flows that are presented by the so-called exact solutions of the Navier-Stokes equations, including the Couette flow between two parallel plates, Hagen-Poiseuille flow through a pipe, and Karman flow above an infinite rotating disk. Chapter 3 is d...

  17. Conservative multigrid methods for Cahn-Hilliard fluids

    International Nuclear Information System (INIS)

    Kim, Junseok; Kang, Kyungkeun; Lowengrub, John

    2004-01-01

    We develop a conservative, second-order accurate fully implicit discretization of the Navier-Stokes (NS) and Cahn-Hilliard (CH) system that has an associated discrete energy functional. This system provides a diffuse-interface description of binary fluid flows with compressible or incompressible flow components [R. Soc. Lond. Proc. Ser. A Math. Phys. Eng. Sci. 454 (1998) 2617]. In this work, we focus on the case of flows containing two immiscible, incompressible and density-matched components. The scheme, however, has a straightforward extension to multi-component systems. To efficiently solve the discrete system at the implicit time-level, we develop a nonlinear multigrid method to solve the CH equation which is then coupled to a projection method that is used to solve the NS equation. We demonstrate convergence of our scheme numerically in both the presence and absence of flow and perform simulations of phase separation via spinodal decomposition. We examine the separate effects of surface tension and external flow on the decomposition. We find surface tension driven flow alone increases coalescence rates through the retraction of interfaces. When there is an applied external shear, the evolution of the flow is nontrivial and the flow morphology repeats itself in time as multiple pinchoff and reconnection events occur. Eventually, the periodic motion ceases and the system relaxes to a global equilibrium. The equilibria we observe appears has a similar structure in all cases although the dynamics of the evolution is quite different. We view the work presented in this paper as preparatory for a detailed investigation of liquid-liquid interfaces with surface tension where the interfaces separate two immiscible fluids [On the pinchoff of liquid-liquid jets with surface tension, in preparation]. To this end, we also include a simulation of the pinchoff of a liquid thread under the Rayleigh instability at finite Reynolds number

  18. Study of two-phase flow redistribution between two passes of a heat exchanger

    International Nuclear Information System (INIS)

    Mendes de Moura, L.F.

    1989-04-01

    The object of the present thesis deals with the study of two-phase flow redistribution between two passes of a heat exchanger. Mass flow rate measurements of each component performed at each channel outlet of the second pass allowed us to determine the influence of mass flow, gas quality, flow direction (upward or downward) and common header geometry upon flow redistribution. Local void fraction inside common header was measured with an optical probe. A two-dimensional two-phase flow computational code was developed from a two-fluid model. Modelling of interfacial momentum transfer was used in order to take into account twp-phase flow patterns in common headers. Numerical simulation results show qualitative agreement with experimental results. Present theoretical model limitations are analysed and future improvements are proposed [fr

  19. Chelyabinsk fireball and Dyatlov pass tragedy

    Science.gov (United States)

    Kochemasov, G. G.

    2013-09-01

    The Chelyabinsk bolide as well as the Kunashak meteorite in 1949 (Fig. 3, black square) hit ground in ectonically peculiar place in the Ural Mountains. The main explosion was followed by a series of weaker bangs. The long Uralian fold belt (Pz) separates two subsectors (1 & 2, Fig. 1) of the Eurasian sector (1+2) of the Eastern hemisphere sectoral structure (Fig. 1). At the Pamirs-Hindukush massif (the "Pamirs' cross") meet four tectonic sectors of this structure: two opposite differently uplifted (Africa-Mediterranean ++ and Asian +) and separating them two opposite differently subsided (Eurasian - and Indooceanic - -). Tectonic bisectors divide the sectors into two differently tectonically elevated subsectors. The Ural Mountains is one of these bisectors dividing the somewhat risen East-European subsector and the relatively fallen West-Siberian one. Even more important is the sharp tectonic boundary between subsided Eurasian sector and uplifted Asian one (between 2 and 3, Fig. 1). Fig. 3 shows distribution of electrophonic bolides over USSR [1]. Observations numbers are in circles. The total of 343 observations is distributed at relevant districts; accompanied meteorites were found only in 23-24 cases; in the chart are excluded background values of 1-2 observations per district. Two areas are obviously anomalous. These of the Urals, and the Eurasia-Asia sectoral contact (Novosibirsk - Yenisei R. - Tunguska). A location in the long Uralian belt is determined by its intersection with the Timan fold belt coming from the northwest (Fig. 3). The catastrophic Dyatlov pass where nine people mysteriously died at once occurs there (triangle in Fig. 3). Mancy aborigines know this place as deadly where killing white shining spheres appear. Moreover this belt intersection is well known among hunters for UFO as the Permian triangle (Fig. 2). They meet there to observe unusual atmospheric shining and other anomalous phenomena. In the Yenisei-Tunguska-Baikal region lightning

  20. Spanish validation of the Premorbid Adjustment Scale (PAS-S).

    Science.gov (United States)

    Barajas, Ana; Ochoa, Susana; Baños, Iris; Dolz, Montse; Villalta-Gil, Victoria; Vilaplana, Miriam; Autonell, Jaume; Sánchez, Bernardo; Cervilla, Jorge A; Foix, Alexandrina; Obiols, Jordi E; Haro, Josep Maria; Usall, Judith

    2013-02-01

    The Premorbid Adjustment Scale (PAS) has been the most widely used scale to quantify premorbid status in schizophrenia, coming to be regarded as the gold standard of retrospective assessment instruments. To examine the psychometric properties of the Spanish version of the PAS (PAS-S). Retrospective study of 140 individuals experiencing a first episode of psychosis (n=77) and individuals who have schizophrenia (n=63), both adult and adolescent patients. Data were collected through a socio-demographic questionnaire and a battery of instruments which includes the following scales: PAS-S, PANSS, LSP, GAF and DAS-sv. The Cronbach's alpha was performed to assess the internal consistency of PAS-S. Pearson's correlations were performed to assess the convergent and discriminant validity. The Cronbach's alpha of the PAS-S scale was 0.85. The correlation between social PAS-S and total PAS-S was 0.85 (p<0.001); while for academic PAS-S and total PAS-S it was 0.53 (p<0.001). Significant correlations were observed between all the scores of each age period evaluated across the PAS-S scale, with a significance value less than 0.001. There was a relationship between negative symptoms and social PAS-S (0.20, p<0.05) and total PAS-S (0.22, p<0.05), but not with academic PAS-S. However, there was a correlation between academic PAS-S and general subscale of the PANSS (0.19, p<0.05). Social PAS-S was related to disability measures (DAS-sv); and academic PAS-S showed discriminant validity with most of the variables of social functioning. PAS-S did not show association with the total LSP scale (discriminant validity). The Spanish version of the Premorbid Adjustment Scale showed appropriate psychometric properties in patients experiencing a first episode of psychosis and who have a chronic evolution of the illness. Moreover, each domain of the PAS-S (social and academic premorbid functioning) showed a differential relationship to other characteristics such as psychotic symptoms, disability

  1. Parallel multigrid methods: implementation on message-passing computers and applications to fluid dynamics. A draft

    International Nuclear Information System (INIS)

    Solchenbach, K.; Thole, C.A.; Trottenberg, U.

    1987-01-01

    For a wide class of problems in scientific computing, in particular for partial differential equations, the multigrid principle has proved to yield highly efficient numerical methods. However, the principle has to be applied carefully: if the multigrid components are not chosen adequately with respect to the given problem, the efficiency may be much smaller than possible. This has been demonstrated for many practical problems. Unfortunately, the general theories on multigrid convergence do not give much help in constructing really efficient multigrid algorithms. Although some progress has been made in bridging the gap between theory and practice during the last few years, there are still several theoretical approaches which are misleading rather than helpful with respect to the objective of real efficiency. The research in finding highly efficient algorithms for non-model applications therefore is still a sophisticated mixture of theoretical considerations, a transfer of experiences from model to real life problems and systematical experimental work. The emphasis of the practical research activity today lies - among others - in the following fields: - finding efficient multigrid components for really complex problems, - combining the multigrid approach with advanced discretizative techniques: - constructing highly parallel multigrid algorithms. In this paper, we want to deal mainly with the last topic

  2. Calculation of trajectory parameters of long pass in basketball.

    Directory of Open Access Journals (Sweden)

    Charikova K.M.

    2011-08-01

    Full Text Available Values of a ball's flight trajectory parameters depending on a distance of long pass, a corner of a ball's start and height of a throwing point are submitted in article. Coordinates of reference points installation for training to long pass with an optimum trajectory of a ball's flight are designed. Requirements to simulators design are determined. Corners of ball's long pass performance in various game situations are recommended.

  3. Pass-Through to Import Prices: Evidence from Developing Countries

    OpenAIRE

    Miguel Fuentes

    2007-01-01

    In this paper I study the pass-through of nominal exchange rate changes to the price of imported goods in four developing countries. The results indicate that 75% of changes in the exchange rate are passed-through to the domestic currency price of imported goods within one quarter. Complete pass-through is attained within one year. There is no evidence that exchange rate pass-through to the price of imported goods has declined over time even in those countries that have managed to reduce infl...

  4. Fluid mechanics

    International Nuclear Information System (INIS)

    Paraschivoiu, I.; Prud'homme, M.; Robillard, L.; Vasseur, P.

    2003-01-01

    This book constitutes at the same time theoretical and practical base relating to the phenomena associated with fluid mechanics. The concept of continuum is at the base of the approach developed in this work. The general advance proceeds of simple balances of forces as into hydrostatic to more complex situations or inertias, the internal stresses and the constraints of Reynolds are taken into account. This advance is not only theoretical but contains many applications in the form of solved problems, each chapter ending in a series of suggested problems. The major part of the applications relates to the incompressible flows

  5. Tuning structural motifs and alloying of bulk immiscible Mo-Cu bimetallic nanoparticles by gas-phase synthesis

    Science.gov (United States)

    Krishnan, Gopi; Verheijen, Marcel A.; Ten Brink, Gert H.; Palasantzas, George; Kooi, Bart J.

    2013-05-01

    Nowadays bimetallic nanoparticles (NPs) have emerged as key materials for important modern applications in nanoplasmonics, catalysis, biodiagnostics, and nanomagnetics. Consequently the control of bimetallic structural motifs with specific shapes provides increasing functionality and selectivity for related applications. However, producing bimetallic NPs with well controlled structural motifs still remains a formidable challenge. Hence, we present here a general methodology for gas phase synthesis of bimetallic NPs with distinctively different structural motifs ranging at a single particle level from a fully mixed alloy to core-shell, to onion (multi-shell), and finally to a Janus/dumbbell, with the same overall particle composition. These concepts are illustrated for Mo-Cu NPs, where the precise control of the bimetallic NPs with various degrees of chemical ordering, including different shapes from spherical to cube, is achieved by tailoring the energy and thermal environment that the NPs experience during their production. The initial state of NP growth, either in the liquid or in the solid state phase, has important implications for the different structural motifs and shapes of synthesized NPs. Finally we demonstrate that we are able to tune the alloying regime, for the otherwise bulk immiscible Mo-Cu, by achieving an increase of the critical size, below which alloying occurs, closely up to an order of magnitude. It is discovered that the critical size of the NP alloy is not only affected by controlled tuning of the alloying temperature but also by the particle shape.Nowadays bimetallic nanoparticles (NPs) have emerged as key materials for important modern applications in nanoplasmonics, catalysis, biodiagnostics, and nanomagnetics. Consequently the control of bimetallic structural motifs with specific shapes provides increasing functionality and selectivity for related applications. However, producing bimetallic NPs with well controlled structural motifs still

  6. A double Fe-Ti oxide and Fe-sulphide liquid immiscibility in the Itsindro Gabbro Complex, Madagascar

    Science.gov (United States)

    Augé, Thierry; Bailly, Laurent; Roig, Jean-Yves

    2017-11-01

    main mineralized zone is located in the upper part of this unit, about 70 m above this discontinuity. The highly differentiated Fe-Ti-P facies of the Lanjanina series in the Itsindro Gabbro Complex have been interpreted as corresponding to the Fe-Ti-P rich, Si-poor member remaining after an immiscible segregation of an evolved mafic magma. The granite dykes and the overlying granite unit represent the second, Si-rich member of the immiscibility process. The presence of large amounts of sulphide is attributed to sulphur contamination of the Fe-Ti-rich liquid. Fe-Ti oxides will tend to crystallize on the sulphide droplets and the accumulation of dense Fe-sulphides (liquid) and associated Fe-Ti oxides (solid) will result in this complex and unusual association taking the form of a net texture.

  7. Investigation of Chemical-Foam Design as a Novel Approach toward Immiscible Foam Flooding for Enhanced Oil Recovery.

    Science.gov (United States)

    Hosseini-Nasab, S M; Zitha, P L J

    2017-10-19

    Strong foam can be generated in porous media containing oil, resulting in incremental oil recovery; however, oil recovery factor is restricted. A large fraction of oil recovered by foam flooding forms an oil-in-water emulsion, so that costly methods may need to be used to separate the oil. Moreover, strong foam could create a large pressure gradient, which may cause fractures in the reservoir. This study presents a novel chemical-foam flooding process for enhanced oil recovery (EOR) from water-flooded reservoirs. The presented method involved the use of chemically designed foam to mobilize the remaining oil after water flooding and then to displace the mobilized oil to the production well. A blend of two anionic surfactant formulations was formulated for this method: (a) IOS, for achieving ultralow interfacial tension (IFT), and (b) AOS, for generating a strong foam. Experiments were performed using Bentheimer sandstone cores, where X-ray CT images were taken during foam generation to find the stability of the advancing front of foam propagation and to map the gas saturation for both the transient and the steady-state flow regimes. Then the proposed chemical-foam strategy for incremental oil recovery was tested through the coinjection of immiscible nitrogen gas and surfactant solutions with three different formulation properties in terms of IFT reduction and foaming strength capability. The discovered optimal formulation contains a foaming agent surfactant, a low IFT surfactant, and a cosolvent, which has a high foam stability and a considerably low IFT (1.6 × 10 -2 mN/m). Coinjection resulted in higher oil recovery and much less MRF than the same process with only using a foaming agent. The oil displacement experiment revealed that coinjection of gas with a blend of surfactants, containing a cosolvent, can recover a significant amount of oil (33% OIIP) over water flooding with a larger amount of clean oil and less emulsion.

  8. Conductivity and phase morphology of carbon black-filled immiscible polymer blends under creep: an experimental and theoretical study.

    Science.gov (United States)

    Pan, Yamin; Liu, Xianhu; Hao, Xiaoqiong; Schubert, Dirk W

    2016-11-30

    Blends of carbon black (CB)-filled co-continuous immiscible polystyrene/poly(methyl-methacrylate) (PS/PMMA) with a PS/PMMA ratio of 50/50 and CB selectively located in the PS phase have been prepared by melt blending. The simultaneous evolution of conductivity and phase morphology of blend composites was investigated under shear and in the quiescent state at 200 °C. It was found that shear deformation had a significant influence on the conductivity of the unfilled PS/PMMA blend and its composites, which was attributed to the change of phase morphology during shear. After the shear stress of 10 kPa, the conductivity of PS/PMMA blends filled with 2 vol% of CB decreased by about two orders of magnitude and the phase morphology transformed from a fine co-continuous structure into a highly elongated lamellar structure. The deformation of phase morphology and the decrease of conductivity were weakened upon decreasing the shear stress or increasing the CB concentration. During subsequent recovery, pronounced phase structure coarsening was observed in the mixture and the conductivity increased as well. A simple model describing the behavior of conductivity under shear deformation was derived and utilized for the description of the experimental data. For the first time, the Burgers model was used to describe the conductivity, and the viscoelastic and viscoplastic parameters were deduced by fitting the conductivity under shear. The results obtained in this study provide a deeper insight into the evolution of phase structure in the conductive polymer blend composite induced by shear deformation.

  9. Principles of fluid mechanics

    International Nuclear Information System (INIS)

    Kreider, J.F.

    1985-01-01

    This book is an introduction on fluid mechanics incorporating computer applications. Topics covered are as follows: brief history; what is a fluid; two classes of fluids: liquids and gases; the continuum model of a fluid; methods of analyzing fluid flows; important characteristics of fluids; fundamentals and equations of motion; fluid statics; dimensional analysis and the similarity principle; laminar internal flows; ideal flow; external laminar and channel flows; turbulent flow; compressible flow; fluid flow measurements

  10. Disappearing fluid?

    International Nuclear Information System (INIS)

    Graney, K.; Chu, J.; Lin, P.C.

    2002-01-01

    Full text: A 78-year old male in end stage renal failure (ESRF) with a background of NIDDM retinopathy, nephropathy, and undergoing continuous ambulatory peritoneal dialysis (CAPD) presented with anorexia, clinically unwell, decreased mobility and right scrotal swelling. There was no difficulty during CAPD exchange except there was a positive fluid balance Peritoneal dialysates remained clear A CAPD peritoneal study was requested. 100Mbq 99mTc Sulphur Colloid was injected into a standard dialysate bag containing dialysate. Anterior dynamic images were acquired over the abdomen pelvis while the dialysate was infused Static images with anatomical markers were performed 20 mins post infusion, before and after patient ambulation and then after drainage. The study demonstrated communication between the peritoneal cavity and the right scrotal sac. Patient underwent right inguinal herniaplasty with a marlex mesh. A repeat CAPD flow study was performed as follow up and no abnormal connection between the peritoneal cavity and the right scrotal sac was demonstrated post operatively. This case study shows that CAPD flow studies can be undertaken as a simple, minimally invasive method to evaluate abnormal peritoneal fluid flow dynamics in patients undergoing CAPD, and have an impact on dialysis management. Copyright (2002) The Australian and New Zealand Society of Nuclear Medicine Inc

  11. Auxillary Fluid Flowmeter

    DEFF Research Database (Denmark)

    RezaNejad Gatabi, Javad; Forouzbakhsh, Farshid; Ebrahimi Darkhaneh, Hadi

    2010-01-01

    The Auxiliary Fluid Flow meter is proposed to measure the fluid flow of any kind in both pipes and open channels. In this kind of flow measurement, the flow of an auxiliary fluid is measured Instead of direct measurement of the main fluid flow. The auxiliary fluid is injected into the main fluid ...

  12. Study and discretization of kinetic models and fluid models at low Mach number

    International Nuclear Information System (INIS)

    Dellacherie, Stephane

    2011-01-01

    This thesis summarizes our work between 1995 and 2010. It concerns the analysis and the discretization of Fokker-Planck or semi-classical Boltzmann kinetic models and of Euler or Navier-Stokes fluid models at low Mach number. The studied Fokker-Planck equation models the collisions between ions and electrons in a hot plasma, and is here applied to the inertial confinement fusion. The studied semi-classical Boltzmann equations are of two types. The first one models the thermonuclear reaction between a deuterium ion and a tritium ion producing an α particle and a neutron particle, and is also in our case used to describe inertial confinement fusion. The second one (known as the Wang-Chang and Uhlenbeck equations) models the transitions between electronic quantified energy levels of uranium and iron atoms in the AVLIS isotopic separation process. The basic properties of these two Boltzmann equations are studied, and, for the Wang-Chang and Uhlenbeck equations, a kinetic-fluid coupling algorithm is proposed. This kinetic-fluid coupling algorithm incited us to study the relaxation concept for gas and immiscible fluids mixtures, and to underline connections with classical kinetic theory. Then, a diphasic low Mach number model without acoustic waves is proposed to model the deformation of the interface between two immiscible fluids induced by high heat transfers at low Mach number. In order to increase the accuracy of the results without increasing computational cost, an AMR algorithm is studied on a simplified interface deformation model. These low Mach number studies also incited us to analyse on cartesian meshes the inaccuracy at low Mach number of Godunov schemes. Finally, the LBM algorithm applied to the heat equation is justified

  13. Installations having pressurised fluid circuits

    International Nuclear Information System (INIS)

    Rigg, S.; Grant, J.

    1977-01-01

    Reference is made to nuclear installations having pressurised coolant flow circuits. Breaches in such circuits may quickly result in much damage to the plant. Devices such as non-return valves, orifice plates, and automatically operated shut-off valves have been provided to prevent or reduce fluid flow through a breached pipe line, but such devices have several disadvantages; they may present large restrictions to normal flow of coolant, and may depend on the operation of ancillary equipment, with consequent delay in bringing them into operation in an emergency. Other expedients that have been adopted to prevent or reduce reverse flow through an upstream breach comprise various forms of hydraulic counter flow brakes. The arrangement described has at least one variable fluid brake comprising a fluidic device connected into a duct in the pressurised circuit, the device having an inlet, an outlet, a vortex chamber between the inlet and outlet, a control jet for introducing fluid into the vortex chamber, connections communicating the inlet and the outlet into one part of the circuit and the control jet into another region at a complementary pressure so that, in the event of a breach in the circuit in one region, fluid passes from the other region to enter the vortex chamber to stimulate pressure to create a flow restricting vortex in the chamber that reduces flow through the breach. The system finds particular application to stream generating pressure tube reactors, such as the steam generating heavy water reactor at UKAEA, Winfrith. (U.K.)

  14. Mouse myocardial first-pass perfusion MR imaging

    NARCIS (Netherlands)

    Coolen, Bram F.; Moonen, Rik P. M.; Paulis, Leonie E. M.; Geelen, Tessa; Nicolay, Klaas; Strijkers, Gustav J.

    2010-01-01

    A first-pass myocardial perfusion sequence for mouse cardiac MRI is presented. A segmented ECG-triggered acquisition combined with parallel imaging acceleration was used to capture the first pass of a Gd-DTPA bolus through the mouse heart with a temporal resolution of 300-400 msec. The method was

  15. Mouse myocardial first-pass perfusion MR imaging

    NARCIS (Netherlands)

    Coolen, B.F.; Moonen, R.P.M.; Paulis, L.E.M.; Geelen, T.; Nicolay, K.; Strijkers, G.J.

    2010-01-01

    A first-pass myocardial perfusion sequence for mouse cardiac MRI is presented. A segmented ECG-triggered acquisition combined with parallel imaging acceleration was used to capture the first pass of a Gd-DTPA bolus through the mouse heart with a temporal resolution of 300–400 msec. The method was

  16. Teaching Strategies for the Forearm Pass in Volleyball

    Science.gov (United States)

    Casebolt, Kevin; Zhang, Peng; Brett, Christine

    2014-01-01

    This article shares teaching strategies for the forearm pass in the game of volleyball and identifies how they will help students improve their performance and development of forearm passing skills. The article also provides an assessment rubric to facilitate student understanding of the skill.

  17. Safety analysis of passing maneuvers using extreme value theory

    Directory of Open Access Journals (Sweden)

    Haneen Farah

    2017-04-01

    The results indicate that this is a promising approach for safety evaluation. On-going work of the authors will attempt to generalize this method to other safety measures related to passing maneuvers, test it for the detailed analysis of the effect of demographic factors on passing maneuvers' crash probability and for its usefulness in a traffic simulation environment.

  18. Analysis of Biomechanical Structure and Passing Techniques in Basketball

    Directory of Open Access Journals (Sweden)

    Ricardo E. Izzo

    2011-06-01

    Full Text Available The basketball is a complex sport, which these days has become increasingly linked to its’ psychophysical aspects rather than to the technical ones. Therefore, it is important to make a through study of the passing techniques from the point of view of the type of the pass and its’ biomechanics. From the point of view of the type of the used passes, the most used is the two-handed chest pass with a frequency of 39.9%. This is followed, in terms of frequency, by one-handed passes – the baseball, with 20.9 % – and by the two-handed over the head pass, with 18.2 %, and finally, one- or two-handed indirect passes (bounces, with 11.2 % and 9.8 %. Considering the most used pass in basketball, from the biomechanical point of view, the muscles involved in the correct movement consider all the muscles of the upper extremity, adding also the shoulder muscles as well as the body fixators (abdominals, hip flexors, knee extensors, and dorsal flexors of the foot. The technical and conditional analysis considers the throwing speed, the throw height and the air resistance. In conclusion, the aim of this study is to give some guidelines to improve the mechanical execution of the movements in training, without neglecting the importance of the harmony of the movements themselves.

  19. 9 CFR 381.79 - Passing of carcasses and parts.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Passing of carcasses and parts. 381.79 Section 381.79 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE... Carcasses and Parts § 381.79 Passing of carcasses and parts. Each carcass and all organs and other parts of...

  20. 12 CFR 560.32 - Pass-through investments.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Pass-through investments. 560.32 Section 560.32 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY LENDING AND INVESTMENT Lending and Investment Powers for Federal Savings Associations § 560.32 Pass-through investments. (a) A...

  1. Self-Assembling, Stable Photonic Bend-Gap Phases in Emulsions of Chiral Nematics with Isotropic Fluids

    Science.gov (United States)

    Huang, Chien-Yueh; Petschek, R. G.

    1998-03-01

    We investigate the possible mesophases in emulsions of chiral nematic liquid crystals with immiscible isotropic fluids and surfactants. The interactions between the orientational fields of the chiral nematics and the surfactant membranes together with the topological constraints affect stability of micellar geometries and produce a new phase diagram. We compare the free energies of various candidate phases. Appropriate, likely realizable conditions on the surfactant and the pitch of the liquid crystal result in thermodynamically stable blue-phase like phases for a relatively wide range of parameters. Processing such emulsions may result in materials with photonic band gaps.

  2. Gyroelastic fluids

    Energy Technology Data Exchange (ETDEWEB)

    Kerbel, G.D.

    1981-01-20

    A study is made of a scale model in three dimensions of a guiding center plasma within the purview of gyroelastic (also known as finite gyroradius-near theta pinch) magnetohydrodynamics. The (nonlinear) system sustains a particular symmetry called isorrhopy which permits the decoupling of fluid modes from drift modes. Isorrhopic equilibria are analyzed within the framework of geometrical optics resulting in (local) dispersion relations and ray constants. A general scheme is developed to evolve an arbitrary linear perturbation of a screwpinch equilibrium as an invertible integral transform (over the complete set of generalized eigenfunctions defined naturally by the equilibrium). Details of the structure of the function space and the associated spectra are elucidated. Features of the (global) dispersion relation owing to the presence of gyroelastic stabilization are revealed. An energy principle is developed to study the stability of the tubular screwpinch.

  3. Gyroelastic fluids

    International Nuclear Information System (INIS)

    Kerbel, G.D.

    1981-01-01

    A study is made of a scale model in three dimensions of a guiding center plasma within the purview of gyroelastic (also known as finite gyroradius-near theta pinch) magnetohydrodynamics. The (nonlinear) system sustains a particular symmetry called isorrhopy which permits the decoupling of fluid modes from drift modes. Isorrhopic equilibria are analyzed within the framework of geometrical optics resulting in (local) dispersion relations and ray constants. A general scheme is developed to evolve an arbitrary linear perturbation of a screwpinch equilibrium as an invertible integral transform (over the complete set of generalized eigenfunctions defined naturally by the equilibrium). Details of the structure of the function space and the associated spectra are elucidated. Features of the (global) dispersion relation owing to the presence of gyroelastic stabilization are revealed. An energy principle is developed to study the stability of the tubular screwpinch

  4. Numerical Modelling of Three-Fluid Flow Using The Level-set Method

    Science.gov (United States)

    Li, Hongying; Lou, Jing; Shang, Zhi

    2014-11-01

    This work presents a numerical model for simulation of three-fluid flow involving two different moving interfaces. These interfaces are captured using the level-set method via two different level-set functions. A combined formulation with only one set of conservation equations for the whole physical domain, consisting of the three different immiscible fluids, is employed. Numerical solution is performed on a fixed mesh using the finite volume method. Surface tension effect is incorporated using the Continuum Surface Force model. Validation of the present model is made against available results for stratified flow and rising bubble in a container with a free surface. Applications of the present model are demonstrated by a variety of three-fluid flow systems including (1) three-fluid stratified flow, (2) two-fluid stratified flow carrying the third fluid in the form of drops and (3) simultaneous rising and settling of two drops in a stationary third fluid. The work is supported by a Thematic and Strategic Research from A*STAR, Singapore (Ref. #: 1021640075).

  5. Resolution of through tubing fluid flow and behind casing fluid flow in multiple completion wells

    International Nuclear Information System (INIS)

    Arnold, D.M.

    1977-01-01

    A method is provided for resolving undesired fluid flow in cement channels behind casing in one producing zone of a multi zone completion well operating on gas lift from the fluid flow from lower producing zones in the same well which is contained in production tubing passing through the producing zone being investigated. Gamma rays which are characteristic of the decay of the unstable isotope nitrogen 16 produced by activation of elemental oxygen nuclei comprising the molecular structure of both the tubing fluid flow and the undesired fluid flow are detected in at least two energy bonds at two longitudinally spaced detectors in a well borehole. By appropriately combining the four count rate signals so producing according to predetermined relationships the two fluid flow components in the same direction may be uniquely distinguished on the basis of their differing distances from the gamma ray detectors. 9 claims, 17 figures

  6. Nano- and microparticles at fluid and biological interfaces

    Science.gov (United States)

    Dasgupta, S.; Auth, T.; Gompper, G.

    2017-09-01

    Systems with interfaces are abundant in both technological applications and biology. While a fluid interface separates two fluids, membranes separate the inside of vesicles from the outside, the interior of biological cells from the environment, and compartmentalize cells into organelles. The physical properties of interfaces are characterized by interface tension, those of membranes are characterized by bending and stretching elasticity. Amphiphilic molecules like surfactants that are added to a system with two immiscible fluids decrease the interface tension and induce a bending rigidity. Lipid bilayer membranes of vesicles can be stretched or compressed by osmotic pressure; in biological cells, also the presence of a cytoskeleton can induce membrane tension. If the thickness of the interface or the membrane is small compared with its lateral extension, both can be described using two-dimensional mathematical surfaces embedded in three-dimensional space. We review recent work on the interaction of particles with interfaces and membranes. This can be micrometer-sized particles at interfaces that stabilise emulsions or form colloidosomes, as well as typically nanometer-sized particles at membranes, such as viruses, parasites, and engineered drug delivery systems. In both cases, we first discuss the interaction of single particles with interfaces and membranes, e.g. particles in external fields, non-spherical particles, and particles at curved interfaces, followed by interface-mediated interaction between two particles, many-particle interactions, interface and membrane curvature-induced phenomena, and applications.

  7. Continuous Reduced Graphene Oxide Film Prepared by Stitching of Nanosheets at the Interface of Two Immiscible Solutions

    International Nuclear Information System (INIS)

    Sohn, Young Ku; Kim, Seog K.; Min, Bong Ki

    2011-01-01

    RGO sheets dispersed in water are prepared by chemical reduction of GO using ascorbic acid. By mixing and sonication of submicron-size RGO sheets in two immiscible liquids (e. g., chloroform and water) for the first time we have prepared a continuous large-area RGO film at the interface. In other words, we have shown that aggregated RGO sheets could be fully stretched at the interface to form a continuous film. The RGO film has been characterized by SEM, TEM, UV-vis absorption, XPS and Raman. The film exhibits high flexibility, transparency, and very long-term stability without forming aggregations. Without requiring vapor deposition, a special instrument, or a filtration followed by a removing the filter paper one could easily achieve a continuous RGO-film in any laboratories. Our solution-based method is much simpler and cost-effective, and very good for large scale mass production. This finding could boost real applications of graphene in laboratory and industry, and provide a new methodology for the fabrication of large-area continuous graphene films. Graphene, an atom-thick two-dimensional (2D) honeycomb lattice sheet of sp 2 -bonded carbon atoms, has recently been emerged as a new promising material in various fields. Because of its gigantic charge carrier mobility it could be applied to field-effect transistors as a substitute of silicon. Due to its transparency and high electrical conductivity, it could be used as a substitute of ITO electrode in solar cells and light-emitting diodes. Other superior properties include large surface area, flexibility, strength, stiffness, and thermal conductivity. These provides wide applications of graphene including supercapa-citor, battery, sensor, storage and drug delivery. For real applications, large-scale of graphene sheets or films needs to be prepared. Large-area (orders of centimeters) graphene films have recently been fabricated using a chemical vapor deposition (CVD) method on various metal substrates. This

  8. ASSESSMENT OF THE ABILITY OF STANDARD SLURRY PUMPS TO MIX MISCIBLE AND IMMISCIBLE LIQUIDS IN TANK 50H

    Energy Technology Data Exchange (ETDEWEB)

    Poirier, M.

    2011-06-15

    Tank 50H is the feed tank for the Saltstone Production Facility (SPF). At present, Tank 50H contains two standard slurry pumps and two Quad Volute slurry pumps. Current requirements and mixing operation is to run three pumps for one hour prior to initiating a feed transfer to SPF. Savannah River Site (SRS) Liquid Waste would like to move one or both of the Quad Volute pumps from Tank 50H to Tank 51H to replace pumps in Tank 51H that are failing. In addition, one of the standard pumps in Tank 50H exhibits high seal leakage and vibration. SRS Liquid Waste requested Savannah River National (SRNL) to conduct a study to evaluate the feasibility of mixing the contents of Tank 50H with one to three standard slurry pumps. To determine the pump requirements to blend miscible and immiscible liquids in Tank 50H, the author reviewed the pilot-scale blending work performed for the Salt Disposition Integration Project (SDIP) and the technical literature, and applied the results to Tank 50H to determine the number, size, and operating parameters needed to blend the tank contents. The conclusions from this analysis are: (1) A single rotating standard slurry pump (with a 13.6 ft{sup 2}/s U{sub 0}D) will be able to blend miscible liquids (i.e., salt solution) in Tank 50H within 4.4 hours. (2) Two rotating standard slurry pumps will be able to blend miscible liquids in Tank 50H within 3.1 hours. (3) Three rotating standard slurry pumps will be able to blend miscible liquids in Tank 50H within 2.5 hours. (4) A single rotating standard slurry pump (with a 13.6 ft{sup 2}/s U{sub 0}D) will disperse Isopar L{reg_sign} droplets that are less than or equal to 15 micron in diameter. If the droplets are less than 15 micron, they will be dispersed within 4.4 hours. Isopar L{reg_sign} provides a lower bound on the maximum size of droplets that will be dispersed by the slurry pumps in Tank 50H. (5) Two rotating standard slurry pumps will disperse Isopar L{reg_sign} droplets less than 15 micron

  9. Three-Dimensional Geologic Characterization of a Great Basin Geothermal System: Astor Pass, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Mayhew, Brett; Siler, Drew L; Faulds, James E

    2013-09-30

    The Great Basin, western USA, exhibits anomalously high heat flow (~75±5 mWm-2) and active faulting and extension, resulting in ~430 known geothermal systems. Recent studies have shown that steeply dipping normal faults in transtensional pull-aparts are a common structural control of these Great Basin geothermal systems. The Astor Pass blind (no surface expression) geothermal system, Nevada, lies along the boundary between the Basin and Range to the east and the Walker Lane to the west. Across this boundary, strain is transferred from dextral shear in the Walker Lane to west-northwest directed extension in the Basin and Range, resulting in a transtensional setting consisting of both northwest-striking, left-stepping dextral faults and northerly striking normal faults. Previous studies indicate that Astor Pass was controlled by the intersection of a northwest-striking dextral normal fault and north-northwest striking normal-dextral fault bounding the western side of the Terraced Hills. Drilling (to ~1200 m) has revealed fluid temperatures of ~94°C, confirming a blind geothermal system. Expanding upon previous work and employing interpretation of 2D seismic reflection data, additional detailed geologic mapping, and well cuttings analysis, a 3-dimensional geologic model of the Astor Pass geothermal system was constructed. The 3D model indicates a complex interaction/intersection area of three discrete fault zones: a northwest-striking dextral-normal fault, a north-northwest-striking normal-dextral fault, and a north-striking west-dipping normal fault. These two discrete, critically-stressed intersection areas plunge moderately to steeply to the NW-NNW and probably act as conduits for upwelling geothermal fluids.

  10. ICRF heating of passing ions in TMX-U

    International Nuclear Information System (INIS)

    Molvik, A.W.; Dimonte, G.; Barter, J.; Campbell, R.; Cummins, W.F.; Falabella, S.; Ferguson, S.W.; Poulsen, P.

    1986-04-01

    By placing ion-cyclotron resonant frequency (ICRF) antennas on both sides of a midplane gas-feed system in the central cell of the Tandem Mirror Experiment-Upgrade (TMX-U), our results have improved in the following areas: (a) The end losses out both ends show a factor of 3 to 4 increase in passing-ion temperatures and a factor of 2 to 3 decrease in passing-ion densities. (b) The passing-ion heating is consistent with Monte Carlo predictions. (c) The plasma density can be sustained by ICRF plus gas fueling as observed on other experiments

  11. Effect of passing vessels on a moored ship

    Energy Technology Data Exchange (ETDEWEB)

    Lean, G H; Price, W A

    1977-11-01

    The effect of passing vessels on a moored ship was investigated by a series of model tests carried out at the Hydraulics Research Station for the Esso Petroleum Co. Ltd., transportation department in connection with their oil jetty at Milford Haven. A main conclusion was that the forces appeared to be due to the pressure gradients associated with the pattern of flow that accompanies the passing ship rather than with the wave system. Slack lines are to be avoided, and some relief in maximum line loads can be achieved by increasing the pretension. The results included the effects of passing vessel speed and ship clearance and draft.

  12. Performance of a Sequential and Parallel Computational Fluid Dynamic (CFD) Solver on a Missile Body Configuration

    National Research Council Canada - National Science Library

    Hisley, Dixie

    1999-01-01

    .... The goals of this report are: (1) to investigate the performance of message passing and loop level parallelization techniques, as they were implemented in the computational fluid dynamics (CFD...

  13. Chaos analysis of viscoelastic chaotic flows of polymeric fluids in a micro-channel

    Energy Technology Data Exchange (ETDEWEB)

    Lim, C. P.; Lam, Y. C., E-mail: myclam@ntu.edu.sg [School of Mechanical and Aerospace Engineering, Nanyang Technological University, 639798 (Singapore); BioSystems and Micromechanics (BioSyM) IRG, Singapore-MIT Alliance for Research and Technology (SMART) Centre, 138602 (Singapore); Han, J. [BioSystems and Micromechanics (BioSyM) IRG, Singapore-MIT Alliance for Research and Technology (SMART) Centre, 138602 (Singapore); Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

    2015-07-15

    Many fluids, including biological fluids such as mucus and blood, are viscoelastic. Through the introduction of chaotic flows in a micro-channel and the construction of maps of characteristic chaos parameters, differences in viscoelastic properties of these fluids can be measured. This is demonstrated by creating viscoelastic chaotic flows induced in an H-shaped micro-channel through the steady infusion of a polymeric fluid of polyethylene oxide (PEO) and another immiscible fluid (silicone oil). A protocol for chaos analysis was established and demonstrated for the analysis of the chaotic flows generated by two polymeric fluids of different molecular weight but with similar relaxation times. The flows were shown to be chaotic through the computation of their correlation dimension (D{sub 2}) and the largest Lyapunov exponent (λ{sub 1}), with D{sub 2} being fractional and λ{sub 1} being positive. Contour maps of D{sub 2} and λ{sub 1} of the respective fluids in the operating space, which is defined by the combination of polymeric fluids and silicone oil flow rates, were constructed to represent the characteristic of the chaotic flows generated. It was observed that, albeit being similar, the fluids have generally distinct characteristic maps with some similar trends. The differences in the D{sub 2} and λ{sub 1} maps are indicative of the difference in the molecular weight of the polymers in the fluids because the driving force of the viscoelastic chaotic flows is of molecular origin. This approach in constructing the characteristic maps of chaos parameters can be employed as a diagnostic tool for biological fluids and, more generally, chaotic signals.

  14. Plea to lower English test pass marks for EEA nurses.

    Science.gov (United States)

    Longhurst, Chris

    2017-08-09

    Nurses from a group campaigning for the rights of EU citizens in the UK after Brexit are meeting the Nursing and Midwifery Council (NMC) to press for the pass mark for English language tests to be lowered.

  15. The relationships between rugby ground pass accuracy and ...

    African Journals Online (AJOL)

    Kathryn van Boom

    2 Department of Physiotherapy, School of Therapeutic Sciences, Faculty of. Health Sciences ... upper body kinematics of the players, specifically the rotations of the torso and ..... relationships between the body movements and pass accuracy ...

  16. A distributed lumped active all-pass network configuration.

    Science.gov (United States)

    Huelsman, L. P.; Raghunath, S.

    1972-01-01

    In this correspondence a new and interesting distributed lumped active network configuration that realizes an all-pass network function is described. A design chart for determining the values of the network elements is included.

  17. Number of Migration Scenarios Passing through each HUC (future)

    Data.gov (United States)

    U.S. Environmental Protection Agency — Forest dwelling neotropical migratory birds require intact forested stopovers during migration. The number of paths that pass through a HUC highlight that huc's...

  18. Number of Migration Scenarios Passing through each HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Forest dwelling neotropical migratory birds require intact forested stopovers during migration. The number of paths that pass through a HUC highlight that huc's...

  19. Axioms for behavioural congruence of single-pass instruction sequences

    NARCIS (Netherlands)

    Bergstra, J.A.; Middelburg, C.A.

    2017-01-01

    In program algebra, an algebraic theory of single-pass instruction sequences, three congruences on instruction sequences are paid attention to: instruction sequence congruence, structural congruence, and behavioural congruence. Sound and complete axiom systems for the first two congruences were

  20. Applicability estimation of flowmeter logging for detecting hydraulic pass

    International Nuclear Information System (INIS)

    Miyakawa, Kimio; Tanaka, Yasuji; Tanaka, Kazuhiro

    1997-01-01

    Estimation of the hydraulic pass governing hydrogeological structure contributes significantly to the siting HLW repository. Flowmeter logging can detect hydraulic passes by measuring vertical flow velocity of groundwater in the borehole. We reviewed application of this logging in situ. The hydraulic pass was detected with combination of ambient flow logging, with pumping and/or injecting induced flow logging. This application showed that the flowmeter logging detected hydraulic passes conveniently and accurately compared with other hydraulic tests. Hydraulic conductivity by using flowmeter logging was assessed above 10 -6 m/sec and within one order from comparison with injection packer tests. We suggest that appropriate application of the flowmeter logging for the siting is conducted before hydraulic tests because test sections and monitoring sections are decided rationally for procurement of quantitative hydraulic data. (author)

  1. Upaya Meningkatkan Kemampuan Passing Bawah Bola Voli Pada

    OpenAIRE

    Irawan, Dedi

    2017-01-01

    This research uses research "Classroom Action Research" (Classroom Action Research) with variables: Improved Passing Down volleyball through media modified rubber ball. Subjects in this study were fifth grade students of State Elementary School 23 Palus Hulu subdistrict Belimbing Melawi totaling 28 students. This research technique using test and measurement, a test with a grating instrument measuring learning outcomes passing down the volleyball game. Analysis of data using percentages. Thes...

  2. Battle of Kasserine Pass: Defeat is a Matter of Scale

    Science.gov (United States)

    2016-05-26

    a ga inst Germany in World War II ; some historians even go so far as to anticipate defeat in the first battles of all major Ameri can wars. Martin ...the battle of Kasserine Pass prove the conventional wisdom that America is doomed to defeat in its first battles? Martin Blumenson, a prominent...Much study of the battle of Kasserine Pass has been done since Martin Blumenson wrote the original history in 1966. The ULTRA and MAGIC intercepts

  3. Terrorismihirm sunnib muretsema kalleid mikrokiibiga passe / Andrus Karnau

    Index Scriptorium Estoniae

    Karnau, Andrus

    2005-01-01

    Alates 1. septembrist 2006 peavad kõik EL-i liikmesriigid hakkama väljastama mikrokiibiga varustatud passe, mille hinnaks võib kujuneda kuni 1000 krooni ja kehtivus lüheneb viiele aastale. Mikrokiip sisaldab inimese biomeetrilisi andmeid - esialgu vaid näokujutist, alates 2008. aastast näpujälgi ning hiljem ka andmeid silmaiirise ja juuksevärvi kohta. Lisa: Biomeetriline pass peidab intiimseid isikuandmeid. Kommenteerib Kohtuekspertiisi ja Kriminalistika Keskuse infojuht Aivar Pau

  4. Transient analysis of the double pass photovoltaic thermal solar collector

    International Nuclear Information System (INIS)

    Alfegi, Ebrahim M.; Sopian, Kamaruzzaman; Abakr, Yousif A.

    2006-01-01

    A mathematical model of a double pass photovoltaic thermal (PV/T) solar collector is reported in this work. It is composed of five couple unsteady nonlinear partial differential equations which are solved by using Gear implicit numerical scheme. That model was validated against experimental data and was found to accurately predict the temperature of the circulated air as well as the temperature distribution of every static elements in a two-pass PV/T solar collector.(Author)

  5. Imaging techniques applied to the study of fluids in porous media

    Energy Technology Data Exchange (ETDEWEB)

    Tomutsa, L.; Doughty, D.; Mahmood, S.; Brinkmeyer, A.; Madden, M.P.

    1991-01-01

    A detailed understanding of rock structure and its influence on fluid entrapment, storage capacity, and flow behavior can improve the effective utilization and design of methods to increase the recovery of oil and gas from petroleum reservoirs. The dynamics of fluid flow and trapping phenomena in porous media was investigated. Miscible and immiscible displacement experiments in heterogeneous Berea and Shannon sandstone samples were monitored using X-ray computed tomography (CT scanning) to determine the effect of heterogeneities on fluid flow and trapping. The statistical analysis of pore and pore throat sizes in thin sections cut from these sandstone samples enabled the delineation of small-scale spatial distributions of porosity and permeability. Multiphase displacement experiments were conducted with micromodels constructed using thin slabs of the sandstones. The combination of the CT scanning, thin section, and micromodel techniques enables the investigation of how variations in pore characteristics influence fluid front advancement, fluid distributions, and fluid trapping. Plugs cut from the sandstone samples were investigated using high resolution nuclear magnetic resonance imaging permitting the visualization of oil, water or both within individual pores. The application of these insights will aid in the proper interpretation of relative permeability, capillary pressure, and electrical resistivity data obtained from whole core studies. 7 refs., 14 figs., 2 tabs.

  6. Synovial fluid analysis

    Science.gov (United States)

    Joint fluid analysis; Joint fluid aspiration ... El-Gabalawy HS. Synovial fluid analysis, synovial biopsy, and synovial pathology. In: Firestein GS, Budd RC, Gabriel SE, McInnes IB, O'Dell JR, eds. Kelly's Textbook of ...

  7. The role of liquid-liquid immiscibility and crystal fractionation in the genesis of carbonatite magmas: insights from Kerimasi melt inclusions

    Science.gov (United States)

    Guzmics, Tibor; Zajacz, Zoltán; Mitchell, Roger H.; Szabó, Csaba; Wälle, Markus

    2015-02-01

    We have reconstructed the compositional evolution of the silicate and carbonate melt, and various crystalline phases in the subvolcanic reservoir of Kerimasi Volcano in the East African Rift. Trace element concentrations of silicate and carbonate melt inclusions trapped in nepheline, apatite and magnetite from plutonic afrikandite (clinopyroxene-nepheline-perovskite-magnetite-melilite rock) and calciocarbonatite (calcite-apatite-magnetite-perovskite-monticellite-phlogopite rock) show that liquid immiscibility occurred during the generation of carbonatite magmas from a CO2-rich melilite-nephelinite magma formed at relatively high temperatures (1,100 °C). This carbonatite magma is notably more calcic and less alkaline than that occurring at Oldoinyo Lengai. The CaO-rich (32-41 wt%) nature and alkali-"poor" (at least 7-10 wt% Na2O + K2O) nature of these high-temperature (>1,000 °C) carbonate melts result from strong partitioning of Ca (relative to Mg, Fe and Mn) in the immiscible carbonate and the CaO-rich nature (12-17 wt%) of its silicate parent (e.g., melilite-nephelinite). Evolution of the Kerimasi carbonate magma can result in the formation of natrocarbonatite melts with similar composition to those of Oldoinyo Lengai, but with pronounced depletion in REE and HFSE elements. We suggest that this compositional difference results from the different initial parental magmas, e.g., melilite-nephelinite at Kerimasi and a nephelinite at Oldoinyo Lengai. The difference in parental magma composition led to a significant difference in the fractionating mineral phase assemblage and the element partitioning systematics upon silicate-carbonate melt immiscibility. LA-ICP-MS analysis of coeval silicate and carbonate melt inclusions provides an opportunity to infer carbonate melt/silicate melt partition coefficients for a wide range of elements. These data show that Li, Na, Pb, Ca, Sr, Ba, B, all REE (except Sc), U, V, Nb, Ta, P, Mo, W and S are partitioned into the carbonate

  8. Validation of the one pass measure for motivational interviewing competence.

    Science.gov (United States)

    McMaster, Fiona; Resnicow, Ken

    2015-04-01

    This paper examines the psychometric properties of the OnePass coding system: a new, user-friendly tool for evaluating practitioner competence in motivational interviewing (MI). We provide data on reliability and validity with the current gold-standard: Motivational Interviewing Treatment Integrity tool (MITI). We compared scores from 27 videotaped MI sessions performed by student counselors trained in MI and simulated patients using both OnePass and MITI, with three different raters for each tool. Reliability was estimated using intra-class coefficients (ICCs), and validity was assessed using Pearson's r. OnePass had high levels of inter-rater reliability with 19/23 items found from substantial to almost perfect agreement. Taking the pair of scores with the highest inter-rater reliability on the MITI, the concurrent validity between the two measures ranged from moderate to high. Validity was highest for evocation, autonomy, direction and empathy. OnePass appears to have good inter-rater reliability while capturing similar dimensions of MI as the MITI. Despite the moderate concurrent validity with the MITI, the OnePass shows promise in evaluating both traditional and novel interpretations of MI. OnePass may be a useful tool for developing and improving practitioner competence in MI where access to MITI coders is limited. Copyright © 2015. Published by Elsevier Ireland Ltd.

  9. Self lubricating fluid bearings

    International Nuclear Information System (INIS)

    Kapich, D.D.

    1980-01-01

    The invention concerns self lubricating fluid bearings, which are used in a shaft sealed system extending two regions. These regions contain fluids, which have to be isolated. A first seal is fluid tight for the first region between the carter shaft and the shaft. The second seal is fluid tight between the carter and the shaft, it communicates with the second region. The first fluid region is the environment surrounding the shaft carter. The second fluid region is a part of a nuclear reactor which contains the cooling fluid. The shaft is conceived to drive a reactor circulating and cooling fluid [fr

  10. Modern fluid dynamics

    CERN Document Server

    Kleinstreuer, Clement

    2018-01-01

    Modern Fluid Dynamics, Second Edition provides up-to-date coverage of intermediate and advanced fluids topics. The text emphasizes fundamentals and applications, supported by worked examples and case studies. Scale analysis, non-Newtonian fluid flow, surface coating, convection heat transfer, lubrication, fluid-particle dynamics, microfluidics, entropy generation, and fluid-structure interactions are among the topics covered. Part A presents fluids principles, and prepares readers for the applications of fluid dynamics covered in Part B, which includes computer simulations and project writing. A review of the engineering math needed for fluid dynamics is included in an appendix.

  11. Efforts to reduce mortality to hydroelectric turbine-passed fish: locating and quantifying damaging shear stresses.

    Science.gov (United States)

    Cada, Glenn; Loar, James; Garrison, Laura; Fisher, Richard; Neitzel, Duane

    2006-06-01

    Severe fluid forces are believed to be a source of injury and mortality to fish that pass through hydroelectric turbines. A process is described by which laboratory bioassays, computational fluid dynamics models, and field studies can be integrated to evaluate the significance of fluid shear stresses that occur in a turbine. Areas containing potentially lethal shear stresses were identified near the stay vanes and wicket gates, runner, and in the draft tube of a large Kaplan turbine. However, under typical operating conditions, computational models estimated that these dangerous areas comprise less than 2% of the flow path through the modeled turbine. The predicted volumes of the damaging shear stress zones did not correlate well with observed fish mortality at a field installation of this turbine, which ranged from less than 1% to nearly 12%. Possible reasons for the poor correlation are discussed. Computational modeling is necessary to develop an understanding of the role of particular fish injury mechanisms, to compare their effects with those of other sources of injury, and to minimize the trial and error previously needed to mitigate those effects. The process we describe is being used to modify the design of hydroelectric turbines to improve fish passage survival.

  12. Security analysis and improvements to the PsychoPass method.

    Science.gov (United States)

    Brumen, Bostjan; Heričko, Marjan; Rozman, Ivan; Hölbl, Marko

    2013-08-13

    In a recent paper, Pietro Cipresso et al proposed the PsychoPass method, a simple way to create strong passwords that are easy to remember. However, the method has some security issues that need to be addressed. To perform a security analysis on the PsychoPass method and outline the limitations of and possible improvements to the method. We used the brute force analysis and dictionary attack analysis of the PsychoPass method to outline its weaknesses. The first issue with the Psychopass method is that it requires the password reproduction on the same keyboard layout as was used to generate the password. The second issue is a security weakness: although the produced password is 24 characters long, the password is still weak. We elaborate on the weakness and propose a solution that produces strong passwords. The proposed version first requires the use of the SHIFT and ALT-GR keys in combination with other keys, and second, the keys need to be 1-2 distances apart. The proposed improved PsychoPass method yields passwords that can be broken only in hundreds of years based on current computing powers. The proposed PsychoPass method requires 10 keys, as opposed to 20 keys in the original method, for comparable password strength.

  13. Geometrical influences on multi-pass laser forming

    International Nuclear Information System (INIS)

    Edwardson, S P; Abed, E; Bartkowiak, K; Dearden, G; Watkins, K G

    2006-01-01

    Laser forming (LF) offers the industrial promise of controlled shaping of metallic and non-metallic components for prototyping, the correction of design shape or distortion and precision adjustment applications. The potential process advantages include precise incremental adjustment, flexibility of application and no mechanical 'spring-back' effect. To date there has been a considerable amount of work carried out on two-dimensional LF, using multi-pass straight line scan strategies to produce a reasonably controlled bend angle in a number of materials, including aerospace alloys. A key area, however, where there is a limited understanding, is the variation in bend angle per pass during multi-pass LF along a single irradiation track; in particular, the decrease in bend angle per pass after many irradiations for a given set of process parameters. Understanding this is essential if the process is to be fully controlled in a manufacturing environment. The research presented in this paper highlights the current theories as to why this occurs and proposes a further reason based on the geometrical effects of the component deformation, which in turn influences the process parameters per pass. This theory is confirmed through empirical analysis of the 2D LF process

  14. A prototype for the PASS Permanent All Sky Survey

    Science.gov (United States)

    Deeg, H. J.; Alonso, R.; Belmonte, J. A.; Horne, K.; Alsubai, K.; Collier Cameron, A.; Doyle, L. R.

    2004-10-01

    A prototype system for the Permanent All Sky Survey (PASS) project is presented. PASS is a continuous photometric survey of the entire celestial sphere with a high temporal resolution. Its major objectives are the detection of all giant-planet transits (with periods up to some weeks) across stars up to mag 10.5, and to deliver continuously photometry that is useful for the study of any variable stars. The prototype is based on CCD cameras with short focal length optics on a fixed mount. A small dome to house it at Teide Observatory, Tenerife, is currently being constructed. A placement at the antarctic Dome C is also being considered. The prototype will be used for a feasibility study of PASS, to define the best observing strategies, and to perform a detailed characterization of the capabilities and scope of the survey. Afterwards, a first partial sky surveying will be started with it. That first survey may be able to detect transiting planets during its first few hundred hours of operation. It will also deliver a data set around which software modules dealing with the various scientific objectives of PASS will be developed. The PASS project is still in its early phase and teams interested in specific scientific objectives, in providing technical expertise, or in participating with own observations are invited to collaborate.

  15. Regenerative beam breakup in multi-pass electron accelerators

    International Nuclear Information System (INIS)

    Vetter, A.M. Jr.

    1980-01-01

    Important electron coincidence experiments in the 1 to 2 GeV range require electron beams of high intensity and high duty factor. To provide such beams, multi-pass electron accelerator systems are being developed at many laboratories. The beam current in multi-pass electron machines is limited by bean breakup which arises from interaction of the electron beam with deflection modes of the accelerator structure. Achieving high beam intensity (50 to 100 μA) will require detailed understanding and careful control of beam breakup phenomena, and is the subject of this thesis. The TM 11 -like traveling wave theory is applied to obtain a physical understanding of beam-mode interactions and the principles of focussing in simple two-pass systems, and is used as a basis for general studies of the dependence of starting current on accelerator parameters in systems of many passes. The concepts developed are applied in analyzing beam breakup in the superconducting recyclotron at Stanford. Measurements of beam interactions with selected breakup modes are incorporated in a simple model in order to estimate relative strengths of breakup modes and to predict starting currents in five-pass operation. The improvement over these predicted currents required in order to obtain 50 to 100 μA beams is shown to be achievable with a combination of increased breakup mode loading and improved beam optics

  16. Fluid mechanics in fluids at rest.

    Science.gov (United States)

    Brenner, Howard

    2012-07-01

    Using readily available experimental thermophoretic particle-velocity data it is shown, contrary to current teachings, that for the case of compressible flows independent dye- and particle-tracer velocity measurements of the local fluid velocity at a point in a flowing fluid do not generally result in the same fluid velocity measure. Rather, tracer-velocity equality holds only for incompressible flows. For compressible fluids, each type of tracer is shown to monitor a fundamentally different fluid velocity, with (i) a dye (or any other such molecular-tagging scheme) measuring the fluid's mass velocity v appearing in the continuity equation and (ii) a small, physicochemically and thermally inert, macroscopic (i.e., non-Brownian), solid particle measuring the fluid's volume velocity v(v). The term "compressibility" as used here includes not only pressure effects on density, but also temperature effects thereon. (For example, owing to a liquid's generally nonzero isobaric coefficient of thermal expansion, nonisothermal liquid flows are to be regarded as compressible despite the general perception of liquids as being incompressible.) Recognition of the fact that two independent fluid velocities, mass- and volume-based, are formally required to model continuum fluid behavior impacts on the foundations of contemporary (monovelocity) fluid mechanics. Included therein are the Navier-Stokes-Fourier equations, which are now seen to apply only to incompressible fluids (a fact well-known, empirically, to experimental gas kineticists). The findings of a difference in tracer velocities heralds the introduction into fluid mechanics of a general bipartite theory of fluid mechanics, bivelocity hydrodynamics [Brenner, Int. J. Eng. Sci. 54, 67 (2012)], differing from conventional hydrodynamics in situations entailing compressible flows and reducing to conventional hydrodynamics when the flow is incompressible, while being applicable to both liquids and gases.

  17. Reduced abrasion drilling fluid

    NARCIS (Netherlands)

    2010-01-01

    A reduced abrasion drilling fluid system and method of drilling a borehole by circulating the reduced abrasion drilling fluid through the borehole is disclosed. The reduced abrasion drilling fluid comprises a drilling fluid, a first additive and a weighting agent, wherein the weighting agent has a

  18. Reduced abrasion drilling fluid

    NARCIS (Netherlands)

    2012-01-01

    A reduced abrasion drilling fluid system and method of drilling a borehole by circulating the reduced abrasion drilling fluid through the borehole is disclosed. The reduced abrasion drilling fluid comprises a drilling fluid, a first additive and a weighting agent, wherein the weighting agent has a

  19. Process fluid cooling system

    International Nuclear Information System (INIS)

    Farquhar, N.G.; Schwab, J.A.

    1977-01-01

    A system of heat exchangers is disclosed for cooling process fluids. The system is particularly applicable to cooling steam generator blowdown fluid in a nuclear plant prior to chemical purification of the fluid in which it minimizes the potential of boiling of the plant cooling water which cools the blowdown fluid

  20. A First-Order One-Pass CPS Transformation

    DEFF Research Database (Denmark)

    Danvy, Olivier; Nielsen, Lasse Reichstein

    2001-01-01

    We present a new transformation of λ-terms into continuation-passing style (CPS). This transformation operates in one pass and is both compositional and first-order. Previous CPS transformations only enjoyed two out of the three properties of being first-order, one-pass, and compositional......, but the new transformation enjoys all three properties. It is proved correct directly by structural induction over source terms instead of indirectly with a colon translation, as in Plotkin's original proof. Similarly, it makes it possible to reason about CPS-transformed terms by structural induction over...... source terms, directly.The new CPS transformation connects separately published approaches to the CPS transformation. It has already been used to state a new and simpler correctness proof of a direct-style transformation, and to develop a new and simpler CPS transformation of control-flow information....

  1. A First-Order One-Pass CPS Transformation

    DEFF Research Database (Denmark)

    Danvy, Olivier; Nielsen, Lasse Reichstein

    2002-01-01

    We present a new transformation of call-by-value lambdaterms into continuation-passing style (CPS). This transformation operates in one pass and is both compositional and first-order. Because it operates in one pass, it directly yields compact CPS programs that are comparable to what one would...... write by hand. Because it is compositional, it allows proofs by structural induction. Because it is first-order, reasoning about it does not require the use of a logical relation. This new CPS transformation connects two separate lines of research. It has already been used to state a new and simpler...... correctness proof of a direct-style transformation, and to develop a new and simpler CPS transformation of control-flow information....

  2. A First-Order One-Pass CPS Transformation

    DEFF Research Database (Denmark)

    Danvy, Olivier; Nielsen, Lasse Reichstein

    2003-01-01

    We present a new transformation of λ-terms into continuation-passing style (CPS). This transformation operates in one pass and is both compositional and first-order. Previous CPS transformations only enjoyed two out of the three properties of being first-order, one-pass, and compositional......, but the new transformation enjoys all three properties. It is proved correct directly by structural induction over source terms instead of indirectly with a colon translation, as in Plotkin's original proof. Similarly, it makes it possible to reason about CPS-transformed terms by structural induction over...... source terms, directly.The new CPS transformation connects separately published approaches to the CPS transformation. It has already been used to state a new and simpler correctness proof of a direct-style transformation, and to develop a new and simpler CPS transformation of control-flow information....

  3. PENINGKATAN HASIL BELAJAR PASSING SEPAK BOLA MELALUI PERMAINAN PEMBURU BINATANG

    Directory of Open Access Journals (Sweden)

    Agung Setiawan

    2015-10-01

    Full Text Available The purpose of this study was to determine the learning outcome approach passing through playing soccer Beast Hunter on fourth grade students of SD Negeri Batuagung 1 Balapulang District of Tegal 2014. This study was conducted in PTK SD Negeri Batuagung 1 Balapulang District of Tegal, the samples in this study were fourth graders, amounting to 24 students. This research method is Classroom Action Research. This study uses 2 cycles. The results showed that the learning outcomes passing football played by using the approach of animals hunters have a positive impact as seen on mastery learning outcomes of students who exceed the predetermined KKM 75 has increased the mastery learning in the first cycle reaches 70.83%, while the second cycle mastery learning reaches 95.83%. It is concluded that learning football passing play tracker approach has a positive impact, which can improve learning outcomes, interest and motivation to learn.

  4. Future-based Static Analysis of Message Passing Programs

    Directory of Open Access Journals (Sweden)

    Wytse Oortwijn

    2016-06-01

    Full Text Available Message passing is widely used in industry to develop programs consisting of several distributed communicating components. Developing functionally correct message passing software is very challenging due to the concurrent nature of message exchanges. Nonetheless, many safety-critical applications rely on the message passing paradigm, including air traffic control systems and emergency services, which makes proving their correctness crucial. We focus on the modular verification of MPI programs by statically verifying concrete Java code. We use separation logic to reason about local correctness and define abstractions of the communication protocol in the process algebra used by mCRL2. We call these abstractions futures as they predict how components will interact during program execution. We establish a provable link between futures and program code and analyse the abstract futures via model checking to prove global correctness. Finally, we verify a leader election protocol to demonstrate our approach.

  5. Preliminary results on the petrology and fluid inclusions of the Rossing uraniferous alaskites

    International Nuclear Information System (INIS)

    Cuney, M.

    1980-01-01

    Petrography, radioactivity distribution and fluid inclusions have been studied in three samples of the Rossing alaskites from the S.H. anomaly outside of the Rossing deposit. After the crystallization of the alaskitic magma which involved oligoclase, biotite, orthoclase and quartz, a deuteric alteration produced a quartz, microcline, albite, muscovite, calcite plus minus chlorite mineral association similar to those observed in several French uraniferous granites. Uranium redistribution occurred during this alteration. From fluid inclusions data, the pressure at the time of the intrusion is estimated to have been at least 6kbar for a temperature of 625 degrees Celsius. Reaction of the magma with the marbles of the Rossing formation led to the boiling of the magma by an increase in the CO 2 partial pressure as well as to its crystallization. Immiscibility between a dense saline (more than 30 per cent NaCl) and CO 2 -rich fluid is proposed to have occurred simultaneously or after the fluid oversaturation of the magma. Part of uraninite is formed at the magmatic stage, another part crystallized from the magmatic fluids in the biotite-rich selvages of the alaskites or in the uraninite-fluorite veins. Uraninite crystallization appears to be mainly controlled by the oxygen fugacity prevailing in the magma and in the surrounding rocks

  6. The serial message-passing schedule for LDPC decoding algorithms

    Science.gov (United States)

    Liu, Mingshan; Liu, Shanshan; Zhou, Yuan; Jiang, Xue

    2015-12-01

    The conventional message-passing schedule for LDPC decoding algorithms is the so-called flooding schedule. It has the disadvantage that the updated messages cannot be used until next iteration, thus reducing the convergence speed . In this case, the Layered Decoding algorithm (LBP) based on serial message-passing schedule is proposed. In this paper the decoding principle of LBP algorithm is briefly introduced, and then proposed its two improved algorithms, the grouped serial decoding algorithm (Grouped LBP) and the semi-serial decoding algorithm .They can improve LBP algorithm's decoding speed while maintaining a good decoding performance.

  7. Delay Bound: Fractal Traffic Passes through Network Servers

    Directory of Open Access Journals (Sweden)

    Ming Li

    2013-01-01

    Full Text Available Delay analysis plays a role in real-time systems in computer communication networks. This paper gives our results in the aspect of delay analysis of fractal traffic passing through servers. There are three contributions presented in this paper. First, we will explain the reasons why conventional theory of queuing systems ceases in the general sense when arrival traffic is fractal. Then, we will propose a concise method of delay computation for hard real-time systems as shown in this paper. Finally, the delay computation of fractal traffic passing through severs is presented.

  8. EXIT Chart Analysis of Binary Message-Passing Decoders

    DEFF Research Database (Denmark)

    Lechner, Gottfried; Pedersen, Troels; Kramer, Gerhard

    2007-01-01

    Binary message-passing decoders for LDPC codes are analyzed using EXIT charts. For the analysis, the variable node decoder performs all computations in the L-value domain. For the special case of a hard decision channel, this leads to the well know Gallager B algorithm, while the analysis can...... be extended to channels with larger output alphabets. By increasing the output alphabet from hard decisions to four symbols, a gain of more than 1.0 dB is achieved using optimized codes. For this code optimization, the mixing property of EXIT functions has to be modified to the case of binary message......-passing decoders....

  9. A double-pass interferometer for measurement of dimensional changes

    International Nuclear Information System (INIS)

    Ren, Dongmei; Lawton, K M; Miller, J A

    2008-01-01

    A double-pass interferometer was developed for measuring dimensional changes of materials in a nanoscale absolute interferometric dilatometer. This interferometer realized the double-ended measurement of a sample using a single-detection double-pass interference system. The nearly balanced design, in which the measurement beam and the reference beam have equal optical path lengths except for the path difference caused by the sample itself, makes this interferometer have high stability, which is verified by the measurement of a quasi-zero-length sample. The preliminary experiments and uncertainty analysis show that this interferometer should be able to measure dimensional changes with characteristic uncertainty at the nanometer level

  10. Loss of European silver eel passing a hydropower station

    DEFF Research Database (Denmark)

    Pedersen, Michael Ingemann; Jepsen, Niels; Aarestrup, Kim

    2012-01-01

    The aim of this study was to assess escapement success of silver eels, Anguilla anguilla (L.), in a lowland river while passing a reservoir and a hydropower station. It was hypothesized that passage success would be lowest at the hydropower station and that survival and migration speed would...... that within the study period, only 23% of the tagged eels reached the tidal limit, mainly due to difficulties in passing the hydropower dam. With such high loss-rates, the escapement goals set in the management plan cannot be achieved...

  11. Increase of the dynamic range of catchup experiments by high-pass filtering

    Energy Technology Data Exchange (ETDEWEB)

    Erskine, D.J.

    1995-08-01

    The release-catchup shock experiment is an important tool for measuring the speed of sound in compressed matter. The catchup of the release wave to the leading shock is sensitively detected optically, through an indicating fluid which produces light approximately to the 4th power of the shock pressure. However, this sensitivity demands a dynamic range which exceeds the capabilities of our digitizer. The catchup signature lies at the top of a flat pulse, thus any signal clipping is a catastrophic loss of data. We have invented a simple and accurate method for recording the catchup signature that is insensitive to signal clipping. A high pass circuit prior to the digitizer is used with post experiment integration. The insensitivity to clipping allows recording the catchup signature at higher gain, and thus with an improved signal to noise ratio.

  12. Solar-blind ultraviolet band-pass filter based on metal—dielectric multilayer structures

    International Nuclear Information System (INIS)

    Wang Tian-Jiao; Xu Wei-Zong; Lu Hai; Ren Fang-Fang; Chen Dun-Jun; Zhang Rong; Zheng You-Dou

    2014-01-01

    Solar-blind ultraviolet (UV) band-pass filter has significant value in many scientific, commercial, and military applications, in which the detection of weak UV signal against a strong background of solar radiation is required. In this work, a solar-blind filter is designed based on the concept of “transparent metal”. The filter consisting of Al/SiO 2 multilayers could exhibit a high transmission in the solar-blind wavelength region and a wide stopband extending from near-ultraviolet to infrared wavelength range. The central wavelength, bandwidth, Q factor, and rejection ratio of the passband are numerically studied as a function of individual layer thickness and multilayer period. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  13. Liquid carry-over in an injection moulded all-polymer chip system for immiscible phase magnetic bead-based solid-phase extraction

    DEFF Research Database (Denmark)

    Kistrup, Kasper; Sørensen, Karen Skotte; Wolff, Anders

    2014-01-01

    We present an all-polymer, single-use microfluidic chip system produced by injection moulding and bonded by ultrasonic welding. Both techniques are compatible with low-cost industrial mass-production. The chip is produced for magnetic bead-based solid-phase extraction facilitated by immiscible......-binding buffer for nucleic acid extraction (0.1 (v/v)% Triton X-100 in 5 M guanidine hydrochloride). A linear relationship was found between the liquid carry-over and mass of magnetic beads used. Interestingly, similar average carry-overs of 1.74(8) nL/µg and 1.72(14) nL/µg were found for Milli-Q water and lysis...

  14. A mass-conserving lattice Boltzmann method with dynamic grid refinement for immiscible two-phase flows

    International Nuclear Information System (INIS)

    Fakhari, Abbas; Geier, Martin; Lee, Taehun

    2016-01-01

    A mass-conserving lattice Boltzmann method (LBM) for multiphase flows is presented in this paper. The proposed LBM improves a previous model (Lee and Liu, 2010 [21]) in terms of mass conservation, speed-up, and efficiency, and also extends its capabilities for implementation on non-uniform grids. The presented model consists of a phase-field lattice Boltzmann equation (LBE) for tracking the interface between different fluids and a pressure-evolution LBM for recovering the hydrodynamic properties. In addition to the mass conservation property and the simplicity of the algorithm, the advantages of the current phase-field LBE are that it is an order of magnitude faster than the previous interface tracking LBE proposed by Lee and Liu (2010) [21] and it requires less memory resources for data storage. Meanwhile, the pressure-evolution LBM is equipped with a multi-relaxation-time (MRT) collision operator to facilitate attainability of small relaxation rates thereby allowing simulation of multiphase flows at higher Reynolds numbers. Additionally, we reformulate the presented MRT-LBM on nonuniform grids within an adaptive mesh refinement (AMR) framework. Various benchmark studies such as a rising bubble and a falling drop under buoyancy, droplet splashing on a wet surface, and droplet coalescence onto a fluid interface are conducted to examine the accuracy and versatility of the proposed AMR-LBM. The proposed model is further validated by comparing the results with other LB models on uniform grids. A factor of about 20 in savings of computational resources is achieved by using the proposed AMR-LBM. As a more demanding application, the Kelvin–Helmholtz instability (KHI) of a shear-layer flow is investigated for both density-matched and density-stratified binary fluids. The KHI results of the density-matched fluids are shown to be in good agreement with the benchmark AMR results based on the sharp-interface approach. When a density contrast between the two fluids exists, a

  15. A mass-conserving lattice Boltzmann method with dynamic grid refinement for immiscible two-phase flows

    Energy Technology Data Exchange (ETDEWEB)

    Fakhari, Abbas, E-mail: afakhari@nd.edu [Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, Notre Dame, IN 46556 (United States); Geier, Martin [TU Braunschweig, Institute for Computational Modeling in Civil Engineering (iRMB), TU-Braunschweig, Pockelsstr. 3, 38106 Braunschweig (Germany); Lee, Taehun [Department of Mechanical Engineering, The City College of the City University of New York, New York, NY 10031 (United States)

    2016-06-15

    A mass-conserving lattice Boltzmann method (LBM) for multiphase flows is presented in this paper. The proposed LBM improves a previous model (Lee and Liu, 2010 [21]) in terms of mass conservation, speed-up, and efficiency, and also extends its capabilities for implementation on non-uniform grids. The presented model consists of a phase-field lattice Boltzmann equation (LBE) for tracking the interface between different fluids and a pressure-evolution LBM for recovering the hydrodynamic properties. In addition to the mass conservation property and the simplicity of the algorithm, the advantages of the current phase-field LBE are that it is an order of magnitude faster than the previous interface tracking LBE proposed by Lee and Liu (2010) [21] and it requires less memory resources for data storage. Meanwhile, the pressure-evolution LBM is equipped with a multi-relaxation-time (MRT) collision operator to facilitate attainability of small relaxation rates thereby allowing simulation of multiphase flows at higher Reynolds numbers. Additionally, we reformulate the presented MRT-LBM on nonuniform grids within an adaptive mesh refinement (AMR) framework. Various benchmark studies such as a rising bubble and a falling drop under buoyancy, droplet splashing on a wet surface, and droplet coalescence onto a fluid interface are conducted to examine the accuracy and versatility of the proposed AMR-LBM. The proposed model is further validated by comparing the results with other LB models on uniform grids. A factor of about 20 in savings of computational resources is achieved by using the proposed AMR-LBM. As a more demanding application, the Kelvin–Helmholtz instability (KHI) of a shear-layer flow is investigated for both density-matched and density-stratified binary fluids. The KHI results of the density-matched fluids are shown to be in good agreement with the benchmark AMR results based on the sharp-interface approach. When a density contrast between the two fluids exists, a

  16. Continuum Mechanical Modelling of Skin-pass Rolling

    DEFF Research Database (Denmark)

    Kijima, Hideo; Bay, Niels

    2007-01-01

    The special contact conditions in skin-pass rolling of steel strip is analyzed by studying plane strain upsetting of thin sheet with low reduction applying long narrow tools and dry friction conditions. An extended sticking region is estimated by an elasto-plastic FEM analysis of the plane strain...

  17. Academic performance and pass rates: Comparison of three first ...

    African Journals Online (AJOL)

    First year students' academic performance in three Life Science courses (Botany, Zoology and Bioscience) was compared. Pass rates, as well as the means and distributions of final marks were analysed. Of the three components (coursework, practical and theory examinations) contributing to the final mark of each course, ...

  18. Parallel imaging for first-pass myocardial perfusion

    NARCIS (Netherlands)

    Irwan, Roy; Lubbers, Daniel D.; van der Vleuten, Pieter A.; Kappert, Peter; Gotte, Marco J. W.; Sijens, Paul E.

    Two parallel imaging methods used for first-pass myocardial perfusion imaging were compared in terms of signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and image artifacts. One used adaptive Time-adaptive SENSitivity Encoding (TSENSE) and the other used GeneRalized Autocalibrating

  19. Protocol-Based Verification of Message-Passing Parallel Programs

    DEFF Research Database (Denmark)

    López-Acosta, Hugo-Andrés; Eduardo R. B. Marques, Eduardo R. B.; Martins, Francisco

    2015-01-01

    We present ParTypes, a type-based methodology for the verification of Message Passing Interface (MPI) programs written in the C programming language. The aim is to statically verify programs against protocol specifications, enforcing properties such as fidelity and absence of deadlocks. We develo...

  20. Variation of rolling noise during train pass-bys

    NARCIS (Netherlands)

    Dittrich, M.G.

    2013-01-01

    Railway pass-by noise measurements on different types of tracks sometimes display a significant difference between the rise and decrease in rolling noise at the front and the back of the train. This can potentially have different causes. Whilst this may not necessarily be relevant for the total

  1. exchange rate pass-through to import and consumer prices

    African Journals Online (AJOL)

    Eyerusalem

    degree of pass-through is estimated by the means of impulse response functions. ..... through from exchange rate fluctuations to each stage of the distribution chain ..... exclusion test (which is asymptotically chi-square distributed) and the results ...... Endogenous variables: DLWCPI YGap DLNEER DLMPI DLCPI DLM2. Root.

  2. Standardized Testing Practices: Effect on Graduation and NCLEX® Pass Rates.

    Science.gov (United States)

    Randolph, Pamela K

    The use standardized testing in pre-licensure nursing programs has been accompanied by conflicting reports of effective practices. The purpose of this project was to describe standardized testing practices in one states' nursing programs and discover if the use of a cut score or oversight of remediation had any effect on (a) first time NCLEX® pass rates, (b) on-time graduation (OTG) or (c) the combination of (a) and (b). Administrators of 38 nursing programs in one Southwest state were sent surveys; surveys were returned by 34 programs (89%). Survey responses were compared to each program's NCLEX pass rate and on-time graduation rate; t-tests were conducted for significant differences associated with a required minimum score (cut score) and oversight of remediation. There were no significant differences in NCLEX pass or on-time graduation rates related to establishment of a cut score. There was a significant difference when the NCLEX pass rate and on-time graduation rate were combined (Outcome Index "OI") with significantly higher program outcomes (P=.02.) for programs without cut-scores. There were no differences associated with faculty oversight of remediation. The results of this study do not support establishment of a cut-score when implementing a standardized testing. Copyright © 2016. Published by Elsevier Inc.

  3. 78 FR 18479 - Drawbridge Operation Regulations; Pass Manchac, LA

    Science.gov (United States)

    2013-03-27

    ... governing the operation of the Canadian National (CN) Railroad automated bascule span drawbridge across Pass....gov . Type the docket number in the ``SEARCH'' box and click ``SEARCH.'' Click on Open Docket Folder... Operations, telephone 202-366-9826. SUPPLEMENTARY INFORMATION: The CN Railroad has requested a temporary...

  4. The ISO 5-pass authentication in χ-Spaces

    DEFF Research Database (Denmark)

    Cáccamo, Mario J.; Crazzolara, Federico; Milicia, Giuseppe

    2002-01-01

    We implement the ISO 5-pass authentication protocol and study its correctness using the χ-Space framework. χ-Spaces is a novel domain specific programming language designed for developing protocols and in particular security protocols. χ-Spaces programming language is an implementation of SPL...

  5. Plants profile of Malakand Pass Hills, District Malakand, Pakistan

    African Journals Online (AJOL)

    use

    2011-11-21

    Nov 21, 2011 ... famous Malakand fort guards the road on both sides of the pass. Malakand is a ... Underneath Malakand Hills, the waters of the River Swat ... southern sloping faces of the hills. They speak ...... Pinus roxburghii Sarg. Antidote ...

  6. Notational analysis on tactical passing skills used by collegiate ...

    African Journals Online (AJOL)

    Notational analysis on tactical passing skills used by collegiate players in an indoor hockey masum tournament. K.N. Hasnor, H Hizan, M.I. Shahril, N.A. Kosni, M.R. Abdullah, A.B.H.M. Maliki, S.M. Mat-Rasid ...

  7. A New One-Pass Transformation into Monadic Normal Form

    DEFF Research Database (Denmark)

    Danvy, Olivier

    2003-01-01

    We present a translation from the call-by-value λ-calculus to monadic normal forms that includes short-cut boolean evaluation. The translation is higher-order, operates in one pass, duplicates no code, generates no chains of thunks, and is properly tail recursive. It makes a crucial use of symbolic...

  8. Track-stitching using graphical models and message passing

    CSIR Research Space (South Africa)

    Van der Merwe, LJ

    2013-07-01

    Full Text Available In order to stitch tracks together, two tasks are required, namely tracking and track stitching. In this study track stitching is performed using a graphical model and message passing (belief propagation) approach. Tracks are modelled as nodes in a...

  9. Vehicle dynamic effects in the course of passing over turnouts

    Directory of Open Access Journals (Sweden)

    Zelenka J.

    2007-11-01

    Full Text Available For the quantification of vehicle dynamic effects at passing over turnouts at a higher speed there was developed a methodology for evaluating of acceleration measured on vehicle axle boxes in the year 2003. The methodology is based on statistical evaluation of lateral and vertical acceleration measured values at passing over both critical parts of a turnout (tongue, frog. The created methodology was used for investigation of vehicle dynamic effects by running at speed up to 230 km/h in the year 2004 in terms of high speed tests of tilting-body unit class 680 CD. There was found relatively high values of dynamic effects already at a speed 160 km/h. In terms of tilting-body unit class 680 tests at a higher speed in curves of chosen track lines of 1st and 2nd corridor of Czech Railways there was carried out also verification of curved turnouts state according to methodology mentioned above with a view to possibility of speed increasing at curved throats of chosen stations. Lateral vehicle dynamic effects at passing over a curved turnout frog area were evaluated. There were carried out simulation calculations of vehicle passing over a turnout based on measured geometric parameters of wheelset as well as chosen turnouts. Results of the calculations were compared with measurements. The increased vehicle dynamic effects found in pulsed beats character influence negatively the turnouts part (not only wheel contacting parts as well as operating life all unsuspended parts of vehicles.

  10. 20 CFR 416.2096 - Basic pass-along rules.

    Science.gov (United States)

    2010-04-01

    ... residents of Medicaid facilities where Medicaid pays more than 50 percent of the cost of their care (see..., unless the State furnishes us satisfactory evidence to the contrary. (b) Meeting the pass-along... was in compliance for such preceding 12-month period. The combined Federal/State payment level for...

  11. Stream capture to form Red Pass, northern Soda Mountains, California

    Science.gov (United States)

    Miller, David; Mahan, Shannon

    2014-01-01

    Red Pass, a narrow cut through the Soda Mountains important for prehistoric and early historic travelers, is quite young geologically. Its history of downcutting to capture streams west of the Soda Mountains, thereby draining much of eastern Fort Irwin, is told by the contrast in alluvial fan sediments on either side of the pass. Old alluvial fan deposits (>500 ka) were shed westward off an intact ridge of the Soda Mountains but by middle Pleistocene time, intermediate-age alluvial fan deposits (~100 ka) were laid down by streams flowing east through the pass into Silurian Valley. The pass was probably formed by stream capture driven by high levels of groundwater on the west side. This is evidenced by widespread wetland deposits west of the Soda Mountains. Sapping and spring discharge into Silurian Valley over millennia formed a low divide in the mountains that eventually was overtopped and incised by a stream. Lessons include the importance of groundwater levels for stream capture and the relatively youthful appearance of this ~100-200 ka feature in the slowly changing Mojave Desert landscape.

  12. Buffels (Wes), Elsies, Sir Lowry's pass, Steenbras and Buffels (Oos)

    CSIR Research Space (South Africa)

    Heinecken, TJE

    1982-06-01

    Full Text Available This report is a synthesis of all available information on five of the smaller rivers discharging in to False bay combined as a single volume. The rivers dealt with are the Buffels (Wes), Elsies, Sir Lowry' Pass, Steenbras and Buffels (Oos). False...

  13. 48 CFR 652.237-71 - Identification/Building Pass.

    Science.gov (United States)

    2010-10-01

    ..., Information Security Programs Division, Industrial Security Branch (DS/ISP/INB) on its cleared employees..., Information Security Programs Division, Industrial Security Branch (DS/ISP/INB): (i) SF-85P, Questionnaire for... Pass (APR 2004) (a) Contractors working in domestic facilities who already possess a security clearance...

  14. A message passing algorithm for the evaluation of social influence

    NARCIS (Netherlands)

    Vassio, Luca; Fagnani, Fabio; Frasca, Paolo; Ozdaglar, Asuman

    2014-01-01

    In this paper, we define a new measure of node centrality in social networks, the Harmonic Influence Centrality, which emerges naturally in the study of social influence over networks. Next, we introduce a distributed message passing algorithm to compute the Harmonic Influence Centrality of each

  15. 20 CFR 416.2099 - Compliance with pass-along.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Compliance with pass-along. 416.2099 Section 416.2099 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SUPPLEMENTAL SECURITY INCOME FOR THE AGED, BLIND, AND DISABLED State Supplementation Provisions; Agreement; Payments § 416.2099 Compliance with...

  16. Note Passing and Gendered Discipline in Vietnamese Schools

    Science.gov (United States)

    Horton, Paul

    2015-01-01

    While researchers agree that note passing is predominantly an activity engaged in by girls, there has been relatively little consideration of why this is the case. In this article, I argue that gendered expectations about the appropriate characters of boys and girls in Vietnam are incorporated into the disciplinary framework of schools, and that…

  17. Evaluating low pass filters on SPECT reconstructed cardiac orientation estimation

    Science.gov (United States)

    Dwivedi, Shekhar

    2009-02-01

    Low pass filters can affect the quality of clinical SPECT images by smoothing. Appropriate filter and parameter selection leads to optimum smoothing that leads to a better quantification followed by correct diagnosis and accurate interpretation by the physician. This study aims at evaluating the low pass filters on SPECT reconstruction algorithms. Criteria for evaluating the filters are estimating the SPECT reconstructed cardiac azimuth and elevation angle. Low pass filters studied are butterworth, gaussian, hamming, hanning and parzen. Experiments are conducted using three reconstruction algorithms, FBP (filtered back projection), MLEM (maximum likelihood expectation maximization) and OSEM (ordered subsets expectation maximization), on four gated cardiac patient projections (two patients with stress and rest projections). Each filter is applied with varying cutoff and order for each reconstruction algorithm (only butterworth used for MLEM and OSEM). The azimuth and elevation angles are calculated from the reconstructed volume and the variation observed in the angles with varying filter parameters is reported. Our results demonstrate that behavior of hamming, hanning and parzen filter (used with FBP) with varying cutoff is similar for all the datasets. Butterworth filter (cutoff > 0.4) behaves in a similar fashion for all the datasets using all the algorithms whereas with OSEM for a cutoff < 0.4, it fails to generate cardiac orientation due to oversmoothing, and gives an unstable response with FBP and MLEM. This study on evaluating effect of low pass filter cutoff and order on cardiac orientation using three different reconstruction algorithms provides an interesting insight into optimal selection of filter parameters.

  18. STRUCTURE OF ECAP ALUMINIUM AFTER DIFFERENT NUMBER OF PASSES

    Directory of Open Access Journals (Sweden)

    Lucia Ilucová

    2011-05-01

    Full Text Available The structure of high purity (99.99% aluminium processed by equal channel angular pressing in the as pressed state after different number of passes was examined using various stereological methods. An extreme inhomogeneity and complicated anisotropy was observed along the body of rod-like specimens.

  19. Single Pass Collider Memo: Gradient Perturbations of the SLC arc

    Energy Technology Data Exchange (ETDEWEB)

    Weng, W.T.; Sands, M.; /SLAC

    2016-12-16

    As the beam passes through the arcs, the gradient it encounters at each magnet differs from the design value. This deviation may be in part random and in part systematic. In this note we make estimates of the effects to be expected from both kinds of errors.

  20. PENGATURAN PASSING OFF DALAM PENGGUNAAN DOMAIN NAME TERKAIT DENGAN MEREK

    Directory of Open Access Journals (Sweden)

    Herti Yunita Putri

    2016-09-01

    Full Text Available In cyber world we often hear about domain name’s term. Domain name is a unique name to identify the server computer’s name like a web server or email server on a computer network or Internet. Passing off also make causes confusion in using merk from a famous brand or merk on the goods and services. Selected domain name in the internet media often creates the similar domain name with the other parties. This similar domain name are often used by people who are not responsible to take advantages of the domain name for themself. This can be caused by the presence of competition from Internet media business. This things called passing off. This research is a normative juridical research with a qualitative analysis. The legal materials include primary legal, secondary law and tertiary legal materials. Collection technique applied is literary study. Legal materials were analyzed to see the argument implementation of the definition of merk, the definition of domain name, definition of passing off, passing off in use related by merk and domain name and the rules of law in Indonesia related by merk, domain name and passing off. Big wishes in the future it can assist as a basic reference and legal considerations which are useful in Indonesian law practice. There are two passing off related to the merk and domain name, called Crybersquatting and Tiposquatting. Domain name rules are not regulated clearly in merk regulation named Act No. 15 of 2001. It regulated in PP 24 Year 1993 about The Class List of Goods or Services In Merk, Telecommunications are included in the goods or services in merk. Domain name are regulated in UDRP (Uniform Dispute Resolution Policy with competent institutions called ICANN (Internet Corporation for Assigned Names and Numbers. Dalam dunia maya (cyber world, kita sering mendengar istilah domain name. Domain name adalah nama unik yang diberikan untuk mengidentifikasi nama server komputer seperti web server atau email server di

  1. FOREWORD Fluid Mechanics and Fluid Power (FMFP)

    Indian Academy of Sciences (India)

    This section of the Special Issue carries selected articles from the Fluid Mechanics and Fluid. Power Conference held during 12–14 December 2013 at the National Institute of Technology,. Hamirpur (HP). The section includes three review articles and nine original research articles. These were selected on the basis of their ...

  2. Influence of welding passes on grain orientation – The example of a multi-pass V-weld

    International Nuclear Information System (INIS)

    Ye, Jing; Moysan, Joseph; Song, Sung-Jin; Kim, Hak-Joon; Chassignole, Bertrand; Gueudré, Cécile; Dupond, Olivier

    2012-01-01

    The accurate modelling of grain orientations in a weld is important, when accurate ultrasonic test predictions of a welded assembly are needed. To achieve this objective, Electricité de France (EDF) and the Laboratoire de Caractérisation Non Destructive (LCND) have developed a dedicated code, which makes use of information recorded in the welding procedure. Among the welding parameters recorded, although the order in which the welding passes are made is of primary importance in the welding process, this information is not always well known or accurately described. In the present paper we analyse in greater detail the influence of the order of welding passes, using data obtained from the Centre for Advanced Non Destructive Evaluation (CANDE), derived from a dissimilar metal weld (DMW) with buttering. Comparisons are made using grain orientation measurements on a macrograph. - Highlights: ► Influence of welding process on grain structure is studied using the MINA model. ► For the first time the importance of a slight slope of the layers is evaluated. ► Two orders of passes are compared for the modelling approach. ► A major effect is observed due to a change in the order of passes.

  3. Failure probabilities of SiC clad fuel during a LOCA in public acceptable simple SMR (PASS)

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Youho, E-mail: euo@kaist.ac.kr; Kim, Ho Sik, E-mail: hskim25@kaist.ac.kr; NO, Hee Cheon, E-mail: hcno@kaist.ac.kr

    2015-10-15

    Highlights: • Graceful operating conditions of SMRs markedly lower SiC cladding stress. • Steady-state fracture probabilities of SiC cladding is below 10{sup −7} in SMRs. • PASS demonstrates fuel coolability (T < 1300 °C) with sole radiation in LOCA. • SiC cladding failure probabilities of PASS are ∼10{sup −2} in LOCA. • Cold gas gap pressure controls SiC cladding tensile stress level in LOCA. - Abstract: Structural integrity of SiC clad fuels in reference Small Modular Reactors (SMRs) (NuScale, SMART, IRIS) and a commercial pressurized water reactor (PWR) are assessed with a multi-layered SiC cladding structural analysis code. Featured with low fuel pin power and temperature, SMRs demonstrate markedly reduced incore-residence fracture probabilities below ∼10{sup −7}, compared to those of commercial PWRs ∼10{sup −6}–10{sup −1}. This demonstrates that SMRs can serve as a near-term deployment fit to SiC cladding with a sound management of its statistical brittle fracture. We proposed a novel SMR named Public Acceptable Simple SMR (PASS), which is featured with 14 × 14 assemblies of SiC clad fuels arranged in a square ring layout. PASS aims to rely on radiative cooling of fuel rods during a loss of coolant accident (LOCA) by fully leveraging high temperature tolerance of SiC cladding. An overarching assessment of SiC clad fuel performance in PASS was conducted with a combined methodology—(1) FRAPCON-SiC for steady-state performance analysis of PASS fuel rods, (2) computational fluid dynamics code FLUENT for radiative cooling rate of fuel rods during a LOCA, and (3) multi-layered SiC cladding structural analysis code with previously developed SiC recession correlations under steam environments for both steady-state and LOCA. The results show that PASS simultaneously maintains desirable fuel cooling rate with the sole radiation and sound structural integrity of fuel rods for over 36 days of a LOCA without water supply. The stress level of

  4. Statistics of Epidemics in Networks by Passing Messages

    Science.gov (United States)

    Shrestha, Munik Kumar

    Epidemic processes are common out-of-equilibrium phenomena of broad interdisciplinary interest. In this thesis, we show how message-passing approach can be a helpful tool for simulating epidemic models in disordered medium like networks, and in particular for estimating the probability that a given node will become infectious at a particular time. The sort of dynamics we consider are stochastic, where randomness can arise from the stochastic events or from the randomness of network structures. As in belief propagation, variables or messages in message-passing approach are defined on the directed edges of a network. However, unlike belief propagation, where the posterior distributions are updated according to Bayes' rule, in message-passing approach we write differential equations for the messages over time. It takes correlations between neighboring nodes into account while preventing causal signals from backtracking to their immediate source, and thus avoids "echo chamber effects" where a pair of adjacent nodes each amplify the probability that the other is infectious. In our first results, we develop a message-passing approach to threshold models of behavior popular in sociology. These are models, first proposed by Granovetter, where individuals have to hear about a trend or behavior from some number of neighbors before adopting it themselves. In thermodynamic limit of large random networks, we provide an exact analytic scheme while calculating the time dependence of the probabilities and thus learning about the whole dynamics of bootstrap percolation, which is a simple model known in statistical physics for exhibiting discontinuous phase transition. As an application, we apply a similar model to financial networks, studying when bankruptcies spread due to the sudden devaluation of shared assets in overlapping portfolios. We predict that although diversification may be good for individual institutions, it can create dangerous systemic effects, and as a result

  5. Trace elements in migrating high-temperature fluids: Effects of diffusive exchange with the adjoining solid

    Science.gov (United States)

    Kenyon, Patricia M.

    1993-01-01

    Trace element concentrations and isotopic ratios are frequently used to study the behavior of high-temperature fluids in both metamorphic and igneous systems. Many theoretical formulations of the effects of fluid migration on trace elements have assumed instantaneous reequilibration between the migrating fluid and the solid material through which it is passing. This paper investigates the additional effects which arise when equilibration is not instantaneous due to a limited rate of diffusion in the solid, using an analytical steady state solution to a set of partial differential equations describing the exchange of trace elements between the fluid and the solid during the migration of the fluid.

  6. Numerical modeling of frozen wave instability in fluids with high viscosity contrast

    Energy Technology Data Exchange (ETDEWEB)

    Lyubimov, D V; Ivantsov, A O; Lyubimova, T P [Theoretical Physics Department, Perm State University, Perm (Russian Federation); Khilko, G L, E-mail: lyubimovat@mail.ru [Institute of Continuous Media Mechanics UB RAS, Perm (Russian Federation)

    2016-12-15

    This paper deals with the direct numerical simulation of quasi-stationary (frozen) wave formation at the interface of two immiscible fluids with large viscosity contrast, in a rectangular container subjected to the horizontal vibrations of finite frequency and amplitude. The critical conditions for the origination of a frozen wave as well as the dependences of the frozen wave height and wavelength on the vibration intensity are obtained. The time-evolution of the interface shape during the vibration period is analyzed. Numerical results are found to be in a good agreement with known experimental and linear stability results. The average deformation of the interface and the structure of average flows are calculated for different vibration intensities. It is shown that a change in the dependencies of the frozen wave characteristics on the vibration intensity follows a change in average flow structure. (paper)

  7. Lectures on fluid mechanics

    CERN Document Server

    Shinbrot, Marvin

    2012-01-01

    Readable and user-friendly, this high-level introduction explores the derivation of the equations of fluid motion from statistical mechanics, classical theory, and a portion of the modern mathematical theory of viscous, incompressible fluids. 1973 edition.

  8. Synovial Fluid Analysis

    Science.gov (United States)

    ... Plasma Free Metanephrines Platelet Count Platelet Function Tests Pleural Fluid Analysis PML-RARA Porphyrin Tests Potassium Prealbumin ... is being tested? Synovial fluid is a thick liquid that acts as a lubricant for the body's ...

  9. Electric fluid pump

    Science.gov (United States)

    Van Dam, Jeremy Daniel; Turnquist, Norman Arnold; Raminosoa, Tsarafidy; Shah, Manoj Ramprasad; Shen, Xiaochun

    2015-09-29

    An electric machine is presented. The electric machine includes a hollow rotor; and a stator disposed within the hollow rotor, the stator defining a flow channel. The hollow rotor includes a first end portion defining a fluid inlet, a second end portion defining a fluid outlet; the fluid inlet, the fluid outlet, and the flow channel of the stator being configured to allow passage of a fluid from the fluid inlet to the fluid outlet via the flow channel; and wherein the hollow rotor is characterized by a largest cross-sectional area of hollow rotor, and wherein the flow channel is characterized by a smallest cross-sectional area of the flow channel, wherein the smallest cross-sectional area of the flow channel is at least about 25% of the largest cross-sectional area of the hollow rotor. An electric fluid pump and a power generation system are also presented.

  10. Cerebrospinal fluid culture

    Science.gov (United States)

    ... Alternative Names Culture - CSF; Spinal fluid culture; CSF culture Images Pneumococci organism References Karcher DS, McPherson RA. Cerebrospinal, synovial, serous body fluids, and alternative specimens. In: McPherson RA, Pincus ...

  11. Cerebrospinal fluid leak (image)

    Science.gov (United States)

    ... brain and spinal cord by acting like a liquid cushion. The fluid allows the organs to be buoyant protecting them from blows or other trauma. Inside the skull the cerebrospinal fluid is contained by the dura which covers ...

  12. Computational Fluid Dynamics

    International Nuclear Information System (INIS)

    Myeong, Hyeon Guk

    1999-06-01

    This book deals with computational fluid dynamics with basic and history of numerical fluid dynamics, introduction of finite volume method using one-dimensional heat conduction equation, solution of two-dimensional heat conduction equation, solution of Navier-Stokes equation, fluid with heat transport, turbulent flow and turbulent model, Navier-Stokes solution by generalized coordinate system such as coordinate conversion, conversion of basic equation, program and example of calculation, application of abnormal problem and high speed solution of numerical fluid dynamics.

  13. Flow of two stratified fluids in an open channel with addition of fluids along the channel length

    International Nuclear Information System (INIS)

    Gardner, G.C.

    1980-01-01

    It is shown that two stably stratified fluids flowing in an open channel have two critical flow conditions. The one at higher flowrates is equivalent to the choked flow condition of a single fluid over a broad-crested weir, when the Froude number is unity. The lower critical condition imposes restrictions, which define the system if fluids are added progressively along the channel length and the flowrates increase from low to high values. However, if the flowrate does not become sufficiently large to pass through the lower critical condition, this condition will then define a form of choking, which again determines the system. It is shown that an important special case, with the proportional flowrates of the two fluids kept constant, has an analytical solution in which the relative depths of the fluids is a constant along the channel. Other systems must be solved numerically. (orig.)

  14. Fluid Statics and Archimedes

    Indian Academy of Sciences (India)

    librium of a vertical slice fluid (Figure Id) of height H and again using the fact .... same fluid having the same shape and same volume as the body. This fluid volume .... example, can be caused by the heating of air near the ground by the sun ...

  15. Fullerol ionic fluids

    KAUST Repository

    Fernandes, Nikhil; Dallas, Panagiotis; Rodriguez, Robert; Bourlinos, Athanasios B.; Georgakilas, Vasilios; Giannelis, Emmanuel P.

    2010-01-01

    ®). The ionic fluid was compared to a control synthesized by mixing the partially protonated form (sodium form) of the fullerols with the same oligomeric amine in the same ratio as in the ionic fluids (20 wt% fullerol). In the fullerol fluid the ionic bonding

  16. Free surface modelling with two-fluid model and reduced numerical diffusion of the interface

    International Nuclear Information System (INIS)

    Strubelj, Luka; Tiselj, Izrok

    2008-01-01

    Full text of publication follows: The free surface flows are successfully modelled with one of existing free surface models, such as: level set method, volume of fluid method (with/without surface reconstruction), front tracking, two-fluid model (two momentum equations) with modified interphase force and others. The main disadvantage of two-fluid model used for simulations of free surface flows is numerical diffusion of the interface, which can be significantly reduced using the method presented in this paper. Several techniques for reduction of numerical diffusion of the interface have been implemented in the volume of fluid model and are based on modified numerical schemes for advection of volume fraction near the interface. The same approach could be used also for two-fluid method, but according to our experience more successful reduction of numerical diffusion of the interface can be achieved with conservative level set method. Within the conservative level set method, continuity equation for volume fraction is solved and after that the numerical diffusion of the interface is reduced in such a way that the thickness of the interface is kept constant during the simulation. Reduction of the interface diffusion can be also called interface sharpening. In present paper the two-fluid model with interface sharpening is validated on Rayleigh-Taylor instability. Under assumptions of isothermal and incompressible flow of two immiscible fluids, we simulated a system with the fluid of higher density located above the fluid of smaller density in two dimensions. Due to gravity in the system, fluid with higher density moves below the fluid with smaller density. Initial condition is not a flat interface between the fluids, but a sine wave with small amplitude, which develops into a mushroom-like structure. Mushroom-like structure in simulation of Rayleigh-Taylor instability later develops to small droplets as result of numerical dispersion of interface (interface sharpening

  17. Pass-band reconfigurable spoof surface plasmon polaritons

    Science.gov (United States)

    Zhang, Hao Chi; He, Pei Hang; Gao, Xinxin; Tang, Wen Xuan; Cui, Tie Jun

    2018-04-01

    In this paper, we introduce a new scheme to construct the band-pass tunable filter based on the band-pass reconfigurable spoof surface plasmon polaritons (SPPs), whose cut-off frequencies at both sides of the passband can be tuned through changing the direct current (DC) bias of varactors. Compared to traditional technology (e.g. microstrip filters), the spoof SPP structure can provide more tight field confinement and more significant field enhancement, which is extremely valuable for many system applications. In order to achieve this scheme, we proposed a specially designed SPP filter integrated with varactors and DC bias feeding structure to support the spoof SPP passband reconfiguration. Furthermore, the full-wave simulated result verifies the outstanding performance on both efficiency and reconfiguration, which has the potential to be widely used in advanced intelligent systems.

  18. Testing the Turing Test — do Men Pass It?

    Science.gov (United States)

    Adam, Ruth; Hershberg, Uri; Schul, Yaacov; Solomon, Sorin

    We are fascinated by the idea of giving life to the inanimate. The fields of Artificial Life and Artificial Intelligence (AI) attempt to use a scientific approach to pursue this desire. The first steps on this approach hark back to Turing and his suggestion of an imitation game as an alternative answer to the question "can machines think?".1 To test his hypothesis, Turing formulated the Turing test1 to detect human behavior in computers. But how do humans pass such a test? What would you say if you would learn that they do not pass it well? What would it mean for our understanding of human behavior? What would it mean for our design of tests of the success of artificial life? We report below an experiment in which men consistently failed the Turing test.

  19. Belief propagation decoding of quantum channels by passing quantum messages

    International Nuclear Information System (INIS)

    Renes, Joseph M

    2017-01-01

    The belief propagation (BP) algorithm is a powerful tool in a wide range of disciplines from statistical physics to machine learning to computational biology, and is ubiquitous in decoding classical error-correcting codes. The algorithm works by passing messages between nodes of the factor graph associated with the code and enables efficient decoding of the channel, in some cases even up to the Shannon capacity. Here we construct the first BP algorithm which passes quantum messages on the factor graph and is capable of decoding the classical–quantum channel with pure state outputs. This gives explicit decoding circuits whose number of gates is quadratic in the code length. We also show that this decoder can be modified to work with polar codes for the pure state channel and as part of a decoder for transmitting quantum information over the amplitude damping channel. These represent the first explicit capacity-achieving decoders for non-Pauli channels. (fast track communication)

  20. Belief propagation decoding of quantum channels by passing quantum messages

    Science.gov (United States)

    Renes, Joseph M.

    2017-07-01

    The belief propagation (BP) algorithm is a powerful tool in a wide range of disciplines from statistical physics to machine learning to computational biology, and is ubiquitous in decoding classical error-correcting codes. The algorithm works by passing messages between nodes of the factor graph associated with the code and enables efficient decoding of the channel, in some cases even up to the Shannon capacity. Here we construct the first BP algorithm which passes quantum messages on the factor graph and is capable of decoding the classical-quantum channel with pure state outputs. This gives explicit decoding circuits whose number of gates is quadratic in the code length. We also show that this decoder can be modified to work with polar codes for the pure state channel and as part of a decoder for transmitting quantum information over the amplitude damping channel. These represent the first explicit capacity-achieving decoders for non-Pauli channels.

  1. Research on optimizing pass schedule of tandem cold mill

    International Nuclear Information System (INIS)

    Lu, C.; Wang, J.S.; Zhao, Q.L.; Liu, X.H.; Wang, G.D.

    2000-01-01

    In this paper, research on pass schedule of tandem cold mill (TCM) is carried out. According to load (reduction, rolling force, motor power) balance, non-linear equations set with variables of inter-stand thickness is constructed. The pass schedule optimization is carried out by solving the non-linear equations set. As the traditional method, the Newton-Raphson method is used for solving the non-linear equations set. In this paper a new simple method is brought up. On basis of the monotone relations between thickness and load, the inter-stands thickness is adjusted dynamically. The solution of non-linear equations set can be converged by iterative calculation. This method can avoid the derivative calculation used by traditional method. So, this method is simple and calculation speed is high. It is suitable for on-line control. (author)

  2. Analysis and Design of Binary Message-Passing Decoders

    DEFF Research Database (Denmark)

    Lechner, Gottfried; Pedersen, Troels; Kramer, Gerhard

    2012-01-01

    Binary message-passing decoders for low-density parity-check (LDPC) codes are studied by using extrinsic information transfer (EXIT) charts. The channel delivers hard or soft decisions and the variable node decoder performs all computations in the L-value domain. A hard decision channel results...... message-passing decoders. Finally, it is shown that errors on cycles consisting only of degree two and three variable nodes cannot be corrected and a necessary and sufficient condition for the existence of a cycle-free subgraph is derived....... in the well-know Gallager B algorithm, and increasing the output alphabet from hard decisions to two bits yields a gain of more than 1.0 dB in the required signal to noise ratio when using optimized codes. The code optimization requires adapting the mixing property of EXIT functions to the case of binary...

  3. TM-pass polarizer based on multilayer graphene polymer waveguide

    Science.gov (United States)

    Cai, Ke-su; Li, Yue-e.; Wei, Wen-jing; Mu, Xi-jiao; Ma, A.-ning; Wang, Zhong; Song, Dan-ming

    2018-05-01

    A TM-pass polarizer based on multilayer graphene polymer waveguide is proposed and theoretically analyzed. The mode properties, the extinction ratio, the insertion loss and the bandwidth are also discussed. The results show that a TM-pass polarizer, which only guides the TM mode, can be achieved by multilayer graphene polymer waveguide. With length of 150 μm, the proposed polarizer can achieve extinction ratio of 33 dB and insertion loss of 0.5 dB at optical wavelength of 1.55 μm. This device has an excellent performance, including large extinction ratio and low insertion loss within the spectral range from 1.45 μm to 1.6 μm.

  4. A Dynamic Continuation-Passing Style for Dynamic Delimited Continuations

    DEFF Research Database (Denmark)

    Biernacki, Dariusz; Danvy, Olivier; Millikin, Kevin Scott

    2005-01-01

    We present a new abstract machine that accounts for dynamic delimited continuations. We prove the correctness of this new abstract machine with respect to a pre-existing, definitional abstract machine. Unlike this definitional abstract machine, the new abstract machine is in defunctionalized form......, which makes it possible to state the corresponding higher-order evaluator. This evaluator is in continuation+state passing style and threads a trail of delimited continuations and a meta-continuation. Since this style accounts for dynamic delimited continuations, we refer to it as `dynamic continuation......-passing style.' We show that the new machine operates more efficiently than the definitional one and that the notion of computation induced by the corresponding evaluator takes the form of a monad. We also present new examples and a new simulation of dynamic delimited continuations in terms of static ones....

  5. Beam dynamics simulation of a double pass proton linear accelerator

    Directory of Open Access Journals (Sweden)

    Kilean Hwang

    2017-04-01

    Full Text Available A recirculating superconducting linear accelerator with the advantage of both straight and circular accelerator has been demonstrated with relativistic electron beams. The acceleration concept of a recirculating proton beam was recently proposed [J. Qiang, Nucl. Instrum. Methods Phys. Res., Sect. A 795, 77 (2015NIMAER0168-900210.1016/j.nima.2015.05.056] and is currently under study. In order to further support the concept, the beam dynamics study on a recirculating proton linear accelerator has to be carried out. In this paper, we study the feasibility of a two-pass recirculating proton linear accelerator through the direct numerical beam dynamics design optimization and the start-to-end simulation. This study shows that the two-pass simultaneous focusing without particle losses is attainable including fully 3D space-charge effects through the entire accelerator system.

  6. Fish pass assessment by remote control: a novel framework for quantifying the hydraulics at fish pass entrances

    Science.gov (United States)

    Kriechbaumer, Thomas; Blackburn, Kim; Gill, Andrew; Breckon, Toby; Everard, Nick; Wright, Ros; Rivas Casado, Monica

    2014-05-01

    Fragmentation of aquatic habitats can lead to the extinction of migratory fish species with severe negative consequences at the ecosystem level and thus opposes the target of good ecological status of rivers defined in the EU Water Framework Directive (WFD). In the UK, the implementation of the EU WFD requires investments in fish pass facilities of estimated 532 million GBP (i.e. 639 million Euros) until 2027 to ensure fish passage at around 3,000 barriers considered critical. Hundreds of passes have been installed in the past. However, monitoring studies of fish passes around the world indicate that on average less than half of the fish attempting to pass such facilities are actually successful. There is a need for frameworks that allow the rapid identification of facilities that are biologically effective and those that require enhancement. Although there are many environmental characteristics that can affect fish passage success, past research suggests that variations in hydrodynamic conditions, reflected in water velocities, velocity gradients and turbulences, are the major cues that fish use to seek migration pathways in rivers. This paper presents the first steps taken in the development of a framework for the rapid field-based quantification of the hydraulic conditions downstream of fish passes and the assessment of the attractivity of fish passes for salmonids and coarse fish in UK rivers. For this purpose, a small-sized remote control platform carrying an acoustic Doppler current profiler (ADCP), a GPS unit, a stereo camera and an inertial measurement unit has been developed. The large amount of data on water velocities and depths measured by the ADCP within relatively short time is used to quantify the spatial and temporal distribution of water velocities. By matching these hydraulic features with known preferences of migratory fish, it is attempted to identify likely migration routes and aggregation areas at barriers as well as hydraulic features that

  7. Radiation of ultrarelativistic particles passing through ideal and mosaic crystals

    International Nuclear Information System (INIS)

    Afanas'ev, A.M.

    1977-01-01

    When a charged particle passes through an ideal crystal, then besides the transition radiation, a new kind of radiation, connected with the periodic structure of the crystal is produced. The influence of mosaic structure of a crystal on the intensity of this radiation is considered. Simple analytical expressions for the integral intensity of this radiation for the case of an ideal crystal are obtained. The results show, that the integral radiation intensity depends weakly on the degree of crystal perfection

  8. Verification-Based Interval-Passing Algorithm for Compressed Sensing

    OpenAIRE

    Wu, Xiaofu; Yang, Zhen

    2013-01-01

    We propose a verification-based Interval-Passing (IP) algorithm for iteratively reconstruction of nonnegative sparse signals using parity check matrices of low-density parity check (LDPC) codes as measurement matrices. The proposed algorithm can be considered as an improved IP algorithm by further incorporation of the mechanism of verification algorithm. It is proved that the proposed algorithm performs always better than either the IP algorithm or the verification algorithm. Simulation resul...

  9. Forest Analysis by Single-Pass Millimeterwave SAR Tomography

    OpenAIRE

    Schmitt, Michael; Zhu, Xiao Xiang

    2016-01-01

    Recent investigations show that millimeterwave SAR tomography provides an interesting means for the analysis of forested areas, especially if single-pass systems are employed. Providing very high resolutions in the decimeter domain and highly coherent data also for slightly windy conditions, even individual trees can be considered. Besides, it has been shown that a certain amount of canopy penetration is possible in spite of the short wavelength.

  10. Basic rules for various liquids passing through nuclear track membranes

    International Nuclear Information System (INIS)

    Guo Shilun; Hao Xiuhong; Wang Yulan; Fan Zhongjun; Zhao Yuhua; Zhao Chongde

    1995-01-01

    The authors describes the new understanding obtained from the studies of NTM for various liquid media, including: (1) basic rule of pure liquids passing through NTM; (2) various methods for the determination of viscosity of liquids by NTM; (3) determination of solute concentration in various solutions by NTM; (4) rapid separation of mixed liquids and chemical separation by NTM; (5) blocking phenomenon of NTM by solid particles in liquids and the blocking formula; and (6) basic rules of filtration of bacteria by NTM

  11. Endogenous trade participation with incomplete exchange rate pass-through

    OpenAIRE

    Imura, Yuko

    2013-01-01

    This paper investigates the implications of endogenous trade participation for international business cycles, trade flow dynamics and exchange rate pass-through when price adjustments are staggered across firms. I develop a two-country dynamic stochastic general equilibrium model wherein firms make state-dependent decisions on entry and exit in the export market and the frequency of price adjustment is time-dependent. Consistent with recent empirical findings, producers of traded goods in thi...

  12. Interest Rate Pass-through in Sri Lanka

    OpenAIRE

    Amarasekara, Chandranath

    2005-01-01

    The Central Bank of Sri Lanka has increasingly been relying on interest rates as the instrument for conducting monetary policy. Changes to the key monetary policy variables, the Repo and the Reverse Repo rates, are initially expected to be reflected in the OMO rates and the call money market rates, before being passedthrough to commercial bank retail interest rates. It is important to obtain a good understanding of the speed and magnitude of the interest rate pass-through to make timely monet...

  13. Tropical field performance of dual-pass PV tray dryer

    Science.gov (United States)

    Iskandar, A. Noor; Ya'acob, M. E.; Anuar, M. S.

    2017-09-01

    Solar Photovoltaic technology has become the preferable solution in many countries around the globe to solve the ever increasing energy demand of the consumers. In line with the consumer need, food processing technology has huge potentials of integration with the renewable energy resources especially in drying process which consumes the highest electricity loads. Traditionally, the solar dryer technology was applied in agriculture and food industries utilizing the sun's energy for drying process, but this is highly dependable on the weather condition and surrounding factors. This work shares some field performance of the new design of portable dual-pass PV tray dryer for drying crops in an enclosed system. The dual-pass PV tray dryer encompass a lightweight aluminium box structure with dimensions of 1.1m (L) x 0.6m (W) x 0.2m (H) and can hold a load capacity of 300g - 3kg of crop depending on the types of the crops. Experiments of field performance monitoring were conducted in October -November 2016 which justifies a considerable reduction in time and crops quality improvement when using the dual-pass PV tray dryer as compared to direct-sun drying.

  14. Incentive Pass-through for Residential Solar Systems in California

    Energy Technology Data Exchange (ETDEWEB)

    Dong, C. G. [Univ. of Texas, Austin, TX (United States); Wiser, Ryan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Rai, Varun [Univ. of Texas, Austin, TX (United States)

    2014-10-01

    The deployment of solar photovoltaic (PV) systems has grown rapidly over the last decade, partly because of various government incentives. In the United States, among the largest and longest-running incentives have been those established in California. Building on past research, this report addresses the still-unanswered question: to what degree have the direct PV incentives in California been passed through from installers to consumers? This report helps address this question by carefully examining the residential PV market in California (excluding a certain class of third-party-owned PV systems) and applying both a structural-modeling approach and a reduced-form regression analysis to estimate the incentive pass-through rate. The results suggest an average pass-through rate of direct incentives of nearly 100%, though with regional differences among California counties. While these results could have multiple explanations, they suggest a relatively competitive market and well-functioning subsidy program. Further analysis is required to determine whether similar results broadly apply to other states, to other customer segments, to all third-party-owned PV systems, or to all forms of financial incentives for solar (considering not only direct state subsidies, but also utility electric bill savings and federal tax incentives).

  15. Incremental first pass technique to measure left ventricular ejection fraction

    International Nuclear Information System (INIS)

    Kocak, R.; Gulliford, P.; Hoggard, C.; Critchley, M.

    1980-01-01

    An incremental first pass technique was devised to assess the acute effects of any drug on left ventricular ejection fraction (LVEF) with or without a physiological stress. In particular, the effects of the vasodilater isosorbide dinitrate on LVEF before and after exercise were studied in 11 patients who had suffered cardiac failure. This was achieved by recording the passage of sup(99m)Tc pertechnetate through the heart at each stage of the study using a gamma camera computer system. Consistent values for four consecutive first pass values without exercise or drug in normal subjects illustrated the reproducibility of the technique. There was no significant difference between LVEF values obtained at rest and exercise before or after oral isosorbide dinitrate with the exception of one patient with gross mitral regurgitation. The advantages of the incremental first pass technique are that the patient need not be in sinus rhythm, the effects of physiological intervention may be studied and tests may also be repeated at various intervals during long term follow-up of patients. A disadvantage of the method is the limitation in the number of sequential measurements which can be carried out due to the amount of radioactivity injected. (U.K.)

  16. Fluid and particle mechanics

    CERN Document Server

    Michell, S J

    2013-01-01

    Fluid and Particle Mechanics provides information pertinent to hydraulics or fluid mechanics. This book discusses the properties and behavior of liquids and gases in motion and at rest. Organized into nine chapters, this book begins with an overview of the science of fluid mechanics that is subdivided accordingly into two main branches, namely, fluid statics and fluid dynamics. This text then examines the flowmeter devices used for the measurement of flow of liquids and gases. Other chapters consider the principle of resistance in open channel flow, which is based on improper application of th

  17. Fluid inclusion geothermometry

    Science.gov (United States)

    Cunningham, C.G.

    1977-01-01

    Fluid inclusions trapped within crystals either during growth or at a later time provide many clues to the histories of rocks and ores. Estimates of fluid-inclusion homogenization temperature and density can be obtained using a petrographic microscope with thin sections, and they can be refined using heating and freezing stages. Fluid inclusion studies, used in conjunction with paragenetic studies, can provide direct data on the time and space variations of parameters such as temperature, pressure, density, and composition of fluids in geologic environments. Changes in these parameters directly affect the fugacity, composition, and pH of fluids, thus directly influencing localization of ore metals. ?? 1977 Ferdinand Enke Verlag Stuttgart.

  18. Fluid Mechanics and Fluid Power (FMFP)

    Indian Academy of Sciences (India)

    Amitabh Bhattacharya

    of renewable energy (e.g., via wind, hydrokinetic generators), creating low-cost healthcare ... multiphase flow, turbulence, bio-fluid dynamics, atmospheric flows, microfluidic flows, and ... study the challenging problem of entry of solids in water.

  19. Gain claming in single-pass and double-pass L-band erbium-doped fiber amplifiers

    International Nuclear Information System (INIS)

    Harun, S.W.; Ahmad, H.

    2004-01-01

    Gain clamping is demonstrated in single-pass and double-pass long wavelength band erbium-doped fiber amplifiers. A C/L-band wavelength division multiplexing coupler is used in single-pass system to generate a laser at 1566 nm. The gain for the amplifier is clamped at 15.5 dB with gain variation of less than 0.2 dB from input signal power of -40 to -14 dBm with almost negligible noise figure penalty. However, the flatness of gain spectrum is slightly degraded due to the un-optimisation of erbium-doped fiber length. The advantage of this configuration is that the oscillating light does not appear at the output of the amplifier. A highly efficient gain-clamped long wavelength band erbium-doped fiber amplifiers with improved noise figure characteristic is demonstrated by simply adding a broadband conventional band fiber Bragg grating in double pass system. The combination of the fiber Bragg grating and optical circulator has created laser in the cavity for gain clamping. By adjusting the power combination of pumps 1 and 2, the clamped gain level can be controlled. The amplifier gain is clamped at 28.1 dB from -40 to -25 dBm with gain variation of less than 0.5 dB by setting the pumps 1 and 2 at 59.5 and 50.6 mW, respectively. The gain is also flat from 1574 nm to 1604 nm with gain variation of less than 3 dB. The corresponding noise figure varies from 5.6 to 7.6 dB, which is 0.8 to 2.6 dB reduced compared to those of unclamped amplifier (Authors)

  20. Immobilization of Colloidal Monolayers at Fluid–Fluid Interfaces

    Directory of Open Access Journals (Sweden)

    Peter T. Bähler

    2016-07-01

    Full Text Available Monolayers of colloidal particles trapped at an interface between two immiscible fluids play a pivotal role in many applications and act as essential models in fundamental studies. One of the main advantages of these systems is that non-close packed monolayers with tunable inter-particle spacing can be formed, as required, for instance, in surface patterning and sensing applications. At the same time, the immobilization of particles locked into desired structures to be transferred to solid substrates remains challenging. Here, we describe three different strategies to immobilize monolayers of polystyrene microparticles at water–decane interfaces. The first route is based on the leaking of polystyrene oligomers from the particles themselves, which leads to the formation of a rigid interfacial film. The other two rely on in situ interfacial polymerization routes that embed the particles into a polymer membrane. By tracking the motion of the colloids at the interface, we can follow in real-time the formation of the polymer membranes and we interestingly find that the onset of the polymerization reaction is accompanied by an increase in particle mobility determined by Marangoni flows at the interface. These results pave the way for future developments in the realization of thin tailored composite polymer-particle membranes.

  1. Double-layer optical fiber coating analysis in MHD flow of an elastico-viscous fluid using wet-on-wet coating process

    Directory of Open Access Journals (Sweden)

    Zeeshan Khan

    Full Text Available Modern optical fibers require a double-layer coating on the glass fiber in order to provide protection from signal attenuation and mechanical damage. The most important plastic resins used in wires and optical fibers are plastic polyvinyl chloride (PVC and low and high density polyethylene (LDPE/HDPE, nylon and Polysulfone. One of the most important things which affect the final product after processing is the design of the coating die. In the present study, double-layer optical fiber coating is performed using melt polymer satisfying Oldroyd 8-constant fluid model in a pressure type die with the effect of magneto-hydrodynamic (MHD. Wet-on-wet coating process is applied for double-layer optical fiber coating. The coating process in the coating die is modeled as a simple two-layer Couette flow of two immiscible fluids in an annulus with an assigned pressure gradient. Based on the assumptions of fully developed laminar and MHD flow, the Oldroyd 8-constant model of non-Newtonian fluid of two immiscible resin layers is modeled. The governing nonlinear equations are solved analytically by the new technique of Optimal Homotopy Asymptotic Method (OHAM. The convergence of the series solution is established. The results are also verified by the Adomian Decomposition Method (ADM. The effect of important parameters such as magnetic parameter Mi, the dilatant constant α, the Pseodoplastic constant β, the radii ratio δ, the pressure gradient Ω, the speed of fiber optics V, and the viscosity ratio κ on the velocity profiles, thickness of coated fiber optics, volume flow rate, and shear stress on the fiber optics are investigated. At the end the result of the present work is also compared with the experimental results already available in the literature by taking non-Newtonian parameters tends to zero. Keywords: Non-Newtonian fluid, Oldroyd 8-constant fluid, MHD flow, Double-layer fiber coating, OHAM, ADM, Wet-on-wet coating process

  2. Numerical Investigation on the Effects of a Precursor Wetting Film on the Displacement of Two Immiscible Phases Along a Channel

    KAUST Repository

    Bao, Kai; Salama, Amgad; Sun, Shuyu

    2015-01-01

    A set of numerical experiments has been conducted to study the effect of a precursor fluid layer on the motion of two phase system in a channel. This system is characterized by coupled Cahn-Hillard and Navier-Stokes system together with slip boundary conditions. The solution of the governing equation involves first the solution of Cahn-Hillard equation with semi-implicit and Mixed finite element discritization with a convex splitting scheme. The Navier-Stokes equations are then solved with a P2-P0 mixed finite element method. Three cases have been investigated; in the first the effect of different wettability scenarios with no precursor layer has been investigated. In the second scenario, the effect of the precursor layer for different wettability conditions is investigated. In the third case, the effect of the thickness of the precursor layer is investigated. It is found that, wettability conditions have considerable effect on the flow of the considered two-phase system. Furthermore the existence of the precursor layer has additional influence on the breakthrough of the phases.

  3. Numerical Investigation on the Effects of a Precursor Wetting Film on the Displacement of Two Immiscible Phases Along a Channel

    KAUST Repository

    Bao, Kai

    2015-10-08

    A set of numerical experiments has been conducted to study the effect of a precursor fluid layer on the motion of two phase system in a channel. This system is characterized by coupled Cahn-Hillard and Navier-Stokes system together with slip boundary conditions. The solution of the governing equation involves first the solution of Cahn-Hillard equation with semi-implicit and Mixed finite element discritization with a convex splitting scheme. The Navier-Stokes equations are then solved with a P2-P0 mixed finite element method. Three cases have been investigated; in the first the effect of different wettability scenarios with no precursor layer has been investigated. In the second scenario, the effect of the precursor layer for different wettability conditions is investigated. In the third case, the effect of the thickness of the precursor layer is investigated. It is found that, wettability conditions have considerable effect on the flow of the considered two-phase system. Furthermore the existence of the precursor layer has additional influence on the breakthrough of the phases.

  4. Pass it On – The Path is the Goal

    Directory of Open Access Journals (Sweden)

    Kempf, Petra

    2013-10-01

    Full Text Available Our history is infused with human movement – a phenomenon that has given rise to an imperative relationship between the subject, the environment, and the journeys that unfold while moving. Passing through space is therefore one of the oldest and most practiced forms of human movement. One of our great challenges, however, is the communication and documentation of that experience. This article explores the unfolding of place through the act of mapping by employing storytelling as a means of recording our movements.

  5. Modelling of a one pass smoke tube boiler

    DEFF Research Database (Denmark)

    Karstensen, Claus M. S.; Sørensen, Kim

    2004-01-01

    A nonlinear state-space model with five states describing a one pass smoke tube boiler has been formulated. By means of mass- and energy-balance the model describes the dynamics of the Furnace, the Convection Zone and the Water/Steam Part and the three sub models are merged into an overall model....... The model is further linearized for use in a linear control design. The simulations have been carried out by means of MATLAB/SIMULINK and the models have been verified with measurements from a full scale boiler plant. Parameters in the model that are difficult to calculate have been estimated and the method...

  6. Establishing Pass/Fail Criteria for Bronchoscopy Performance

    DEFF Research Database (Denmark)

    Konge, Lars; Clementsen, Paul; Larsen, Klaus Richter

    2012-01-01

    Background: Several tools have been created to assess competence in bronchoscopy. However, educational guidelines still use an arbitrary number of performed procedures to decide when basic competency is acquired. Objectives: The purpose of this study was to define pass/fail scores for two...... method. In the first we compared bronchoscopy performance scores of 14 novices with the scores of 14 experienced consultants to find the score that best discriminated between the two groups. In the second we asked an expert group of 7 experienced bronchoscopists to judge how a borderline trainee would...

  7. A Calculus of Communicating Systems with Label Passing

    DEFF Research Database (Denmark)

    Engberg, Uffe Henrik; Nielsen, Mogens

    Milner's Calculus of Communicating Systems (CCS) is extended with a mechanism for label passing - as an attempt to remedy some of the shortcomings of CCS w.r.t. dynamic change of agent interconnections. In the extended calculus, restriction is viewed formally as a binder, and the calculus allows...... dynamic change of scope (of label) in connection with communication. It is proved that algebraic properties of strong (and observational) equivalence for CCS are preserved by the extension. Examples illustrating the expressive power of the calculus and its methods for reasoning are given....

  8. Low-pass sequencing for microbial comparative genomics

    Directory of Open Access Journals (Sweden)

    Kennedy Sean

    2004-01-01

    Full Text Available Abstract Background We studied four extremely halophilic archaea by low-pass shotgun sequencing: (1 the metabolically versatile Haloarcula marismortui; (2 the non-pigmented Natrialba asiatica; (3 the psychrophile Halorubrum lacusprofundi and (4 the Dead Sea isolate Halobaculum gomorrense. Approximately one thousand single pass genomic sequences per genome were obtained. The data were analyzed by comparative genomic analyses using the completed Halobacterium sp. NRC-1 genome as a reference. Low-pass shotgun sequencing is a simple, inexpensive, and rapid approach that can readily be performed on any cultured microbe. Results As expected, the four archaeal halophiles analyzed exhibit both bacterial and eukaryotic characteristics as well as uniquely archaeal traits. All five halophiles exhibit greater than sixty percent GC content and low isoelectric points (pI for their predicted proteins. Multiple insertion sequence (IS elements, often involved in genome rearrangements, were identified in H. lacusprofundi and H. marismortui. The core biological functions that govern cellular and genetic mechanisms of H. sp. NRC-1 appear to be conserved in these four other halophiles. Multiple TATA box binding protein (TBP and transcription factor IIB (TFB homologs were identified from most of the four shotgunned halophiles. The reconstructed molecular tree of all five halophiles shows a large divergence between these species, but with the closest relationship being between H. sp. NRC-1 and H. lacusprofundi. Conclusion Despite the diverse habitats of these species, all five halophiles share (1 high GC content and (2 low protein isoelectric points, which are characteristics associated with environmental exposure to UV radiation and hypersalinity, respectively. Identification of multiple IS elements in the genome of H. lacusprofundi and H. marismortui suggest that genome structure and dynamic genome reorganization might be similar to that previously observed in the

  9. S-AMP: Approximate Message Passing for General Matrix Ensembles

    DEFF Research Database (Denmark)

    Cakmak, Burak; Winther, Ole; Fleury, Bernard H.

    2014-01-01

    the approximate message-passing (AMP) algorithm to general matrix ensembles with a well-defined large system size limit. The generalization is based on the S-transform (in free probability) of the spectrum of the measurement matrix. Furthermore, we show that the optimality of S-AMP follows directly from its......We propose a novel iterative estimation algorithm for linear observation models called S-AMP. The fixed points of S-AMP are the stationary points of the exact Gibbs free energy under a set of (first- and second-) moment consistency constraints in the large system limit. S-AMP extends...

  10. Fault-tolerant Agreement in Synchronous Message-passing Systems

    CERN Document Server

    Raynal, Michel

    2010-01-01

    The present book focuses on the way to cope with the uncertainty created by process failures (crash, omission failures and Byzantine behavior) in synchronous message-passing systems (i.e., systems whose progress is governed by the passage of time). To that end, the book considers fundamental problems that distributed synchronous processes have to solve. These fundamental problems concern agreement among processes (if processes are unable to agree in one way or another in presence of failures, no non-trivial problem can be solved). They are consensus, interactive consistency, k-set agreement an

  11. PENN PASS: a program for graduates of foreign dental schools.

    Science.gov (United States)

    Berthold, P; Lopez, N

    1994-01-01

    An increasing number of graduates of foreign dental schools who enroll in advanced standing programs to qualify for licensure calls for dental schools to be prepared to handle not only the curricular demands but also the growing cultural diversity among its student population. The "reeducation" of this student group not only meets the need of foreign dentists for an American degree but may also provide health professionals to service various ethnic populations whose language and culture they are able to understand and identify with. A survey of students and graduates of a two-year Program for Advanced Standing Students (PASS) for graduates of foreign dental schools representing 34 countries aimed to arrive at an understanding of this student group through characterization of the foreign dentists and identification of their attitudes and feelings toward various aspects of the program, the school and faculty and their experience of stress. This report includes description of the distinctive features of the program which cater to specific needs and concerns of this non-traditional group of dental students. PASS students are accepted on the basis of their grades in dental school in home country, scores in the National Dental Board Examination Part I, Test of English as Foreign Language (TOEFL), and ratings in personal interviews. They complete an intensive summer program consisting of didactic and laboratory courses which prepares them for integration with four-year students for the last two years of didactic and clinical curriculum. Cultural diversity seminars, a special English class, PASS class meetings and seminars are unique additions to their program and aim to assist them adjust to the educational, social and cultural systems in an American school. Results of the survey show a majority of the PASS students feel that they are part of the school and that there is someone in the school whom they can approach for problems. An understanding of their ethnic and

  12. Energy and exergy analysis of a two pass photovoltaic –thermal (PV/T) air heater

    Energy Technology Data Exchange (ETDEWEB)

    Srinivas, M.; Jayaraj, S. [Department of Mechanical Engineering, National Institute of Technology, Calicut-673601 (India)

    2013-07-01

    A double pass hybrid solar air (PV/T) heater with slats is designed and fabricated to study elaborately its thermal and electrical performance corresponding to the warm and humid environment. Air as a heat removing fluid is made to flow through upper and lower channels of the collector. The collector is designed in such way that the absorber plate is partially covered by solar cells. Thin metallic strips (called slats) are attached longitudinally at the bottom side of the absorber plate to improve the overall system performance (by increasing the cooling rate of the absorber plate). Thermal and electrical performances of the whole system at different cooling rates are presented. The exergy analysis of double pass hybrid solar air (PV/T) heater with slats has also been carried out. The instantaneous overall energy and overall exergy efficiency of the double pass hybrid (PV/T) solar air heater varies between 29 – 37 percent and 14-17 percent respectively. These obtained values are comparable with that of published results.

  13. Touch sensitive electrorheological fluid based tactile display

    Science.gov (United States)

    Liu, Yanju; Davidson, Rob; Taylor, Paul

    2005-12-01

    A tactile display is programmable device whose controlled surface is intended to be investigated by human touch. It has a great number of potential applications in the field of virtual reality and elsewhere. In this research, a 5 × 5 tactile display array including electrorheological (ER) fluid has been developed and investigated. Force responses of the tactile display array have been measured while a probe was moved across the upper surface. The purpose of this was to simulate the action of touch performed by human finger. Experimental results show that the sensed surface information could be controlled effectively by adjusting the voltage activation pattern imposed on the tactels. The performance of the tactile display is durable and repeatable. The touch sensitivity of this ER fluid based tactile display array has also been investigated in this research. The results show that it is possible to sense the touching force normal to the display's surface by monitoring the change of current passing through the ER fluid. These encouraging results are helpful for constructing a new type of tactile display based on ER fluid which can act as both sensor and actuator at the same time.

  14. Fullerol ionic fluids

    Science.gov (United States)

    Fernandes, Nikhil; Dallas, Panagiotis; Rodriguez, Robert; Bourlinos, Athanasios B.; Georgakilas, Vasilios; Giannelis, Emmanuel P.

    2010-09-01

    We report for the first time an ionic fluid based on hydroxylated fullerenes (fullerols). The ionic fluid was synthesized by neutralizing the fully protonated fullerol with an amine terminated polyethylene/polypropylene oxide oligomer (Jeffamine®). The ionic fluid was compared to a control synthesized by mixing the partially protonated form (sodium form) of the fullerols with the same oligomeric amine in the same ratio as in the ionic fluids (20 wt% fullerol). In the fullerol fluid the ionic bonding significantly perturbs the thermal transitions and melting/crystallization behavior of the amine. In contrast, both the normalized heat of fusion and crystallization of the amine in the control are similar to those of the neat amine consistent with a physical mixture of the fullerols/amine with minimal interactions. In addition to differences in thermal behavior, the fullerol ionic fluid exhibits a complex viscoelastic behavior intermediate between the neat Jeffamine® (liquid-like) and the control (solid-like).

  15. Fiber optic fluid detector

    Science.gov (United States)

    Angel, S.M.

    1987-02-27

    Particular gases or liquids are detected with a fiber optic element having a cladding or coating of a material which absorbs the fluid or fluids and which exhibits a change of an optical property, such as index of refraction, light transmissiveness or fluoresence emission, for example, in response to absorption of the fluid. The fluid is sensed by directing light into the fiber optic element and detecting changes in the light, such as exit angle changes for example, that result from the changed optical property of the coating material. The fluid detector may be used for such purposes as sensing toxic or explosive gases in the atmosphere, measuring ground water contamination or monitoring fluid flows in industrial processes, among other uses. 10 figs.

  16. Fiber optic fluid detector

    Science.gov (United States)

    Angel, S. Michael

    1989-01-01

    Particular gases or liquids are detected with a fiber optic element (11, 11a to 11j) having a cladding or coating of a material (23, 23a to 23j) which absorbs the fluid or fluids and which exhibits a change of an optical property, such as index of refraction, light transmissiveness or fluoresence emission, for example, in response to absorption of the fluid. The fluid is sensed by directing light into the fiber optic element and detecting changes in the light, such as exit angle changes for example, that result from the changed optical property of the coating material. The fluid detector (24, 24a to 24j) may be used for such purposes as sensing toxic or explosive gases in the atmosphere, measuring ground water contamination or monitoring fluid flows in industrial processes, among other uses.

  17. Eutectic, monotectic and immiscibility systems of nimesulide with water-soluble carriers: phase equilibria, solid-state characterisation and in-vivo/pharmacodynamic evaluation.

    Science.gov (United States)

    Abdelkader, Hamdy; Abdallah, Ossama Y; Salem, Hesham; Alani, Adam W G; Alany, Raid G

    2014-10-01

    The solid-state interactions of fused mixtures nimesulide (ND) with polyethylene glycol (PEG) 4000, urea or mannitol were studied through constructing thaw-melt phase equilibrium diagrams. The solid-state characteristics were investigated using differential scanning calorimetry (DSC) and X-ray diffraction (XRD). Various types of interactions were identified such as the formation of a eutectic system of ND-PEG 4000, monotectic system of ND-urea and complete solid immiscibility of ND with mannitol. The effects of carrier concentrations on the equilibrium solubility and in-vitro dissolution characteristics were studied. Linear increases (R(2)  > 0.99) in the aqueous solubility of ND in various concentrations of PEG 4000 and urea were obtained, whereas mannitol did not exhibit any effect on the solubility of ND. Similar trends were obtained with the dissolution efficiency of the fused mixtures of ND with PEG 4000 and urea compared with the corresponding physical mixtures and untreated drug. The analgesic effects of untreated ND and the selected formulations were investigated by evaluating the drug's ability to inhibit the acetic acid-induced writhing response. The analgesic effect of ND in a eutectic mixture with PEG 4000 and a monotectic mixture with urea was potentiated by 3.2 and 2.7-fold respectively compared with the untreated drug. © 2014 Royal Pharmaceutical Society.

  18. Radiation effects on the immiscible polymer blend of nylon1010 and high-impact polystyrene (HIPS) I: Gel/dose curves, mathematical expectation theorem and thermal behaviour

    International Nuclear Information System (INIS)

    Dong, W.; Zhang, W.; Chen, G.; Liu, J.

    2000-01-01

    This paper studies the radiation properties of the immiscible blend of nylon1010 and HIPS. The gel fraction increased with increasing radiation dose. The network was found mostly in nylon1010, the networks were also found in both nylon1010 and HIPS when the dose reaches 0.85 MGy or more. We used the equation and the modified Zhang-Sun-Qian equation to simulate the relationship with the dose and the sol fraction. The latter equation fits well with these polymer blends and the relationship used by it showed better linearity than the one by the equation. We also studied the conditions of formation of the network by the mathematical expectation theorem for the binary system. Thermal properties of polymer blend were observed by DSC curves. The crystallization temperature decreases with increasing dose because the cross-linking reaction inhibited the crystallization procession and destroyed the crystals. The melting temperature also reduced with increasing radiation dose. The dual melting peak gradually shifted to single peak and the high melting peak disappeared at high radiation dose. However, the radiation-induced crystallization was observed by the heat of fusion increasing at low radiation dose. On the other hand, the crystal will be damaged by radiation. A similar conclusion may be drawn by the DSC traces when the polymer blends were crystallized. When the radiation dose increases, the heat of fusion reduces dramatically and so does the heat of crystallization. (author)

  19. Liquid carry-over in an injection moulded all-polymer chip system for immiscible phase magnetic bead-based solid-phase extraction

    Energy Technology Data Exchange (ETDEWEB)

    Kistrup, Kasper, E-mail: kkis@nanotech.dtu.dk [Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech, Building 345 East, DK-2800 Kongens Lyngby (Denmark); Skotte Sørensen, Karen, E-mail: karen@nanotech.dtu.dk [Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech, Building 345 East, DK-2800 Kongens Lyngby (Denmark); Center for Integrated Point of Care Technologies (CiPoC), DELTA, Venlighedsvej 4, DK-2870 Hørsholm (Denmark); Wolff, Anders, E-mail: anders.wolff@nanotech.dtu.dk [Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech, Building 345 East, DK-2800 Kongens Lyngby (Denmark); Fougt Hansen, Mikkel, E-mail: mikkel.hansen@nanotech.dtu.dk [Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech, Building 345 East, DK-2800 Kongens Lyngby (Denmark)

    2015-04-15

    We present an all-polymer, single-use microfluidic chip system produced by injection moulding and bonded by ultrasonic welding. Both techniques are compatible with low-cost industrial mass-production. The chip is produced for magnetic bead-based solid-phase extraction facilitated by immiscible phase filtration and features passive liquid filling and magnetic bead manipulation using an external magnet. In this work, we determine the system compatibility with various surfactants. Moreover, we quantify the volume of liquid co-transported with magnetic bead clusters from Milli-Q water or a lysis-binding buffer for nucleic acid extraction (0.1 (v/v)% Triton X-100 in 5 M guanidine hydrochloride). A linear relationship was found between the liquid carry-over and mass of magnetic beads used. Interestingly, similar average carry-overs of 1.74(8) nL/µg and 1.72(14) nL/µg were found for Milli-Q water and lysis-binding buffer, respectively. - Highlights: • We present an all-polymer mass producible passive filled microfluidic chip system. • Rapid system fabrication is obtained by injection moulding and ultrasonic welding. • The system is made for single-use nucleic acid extraction using magnetic beads. • We systematically map compatibility of the chip system with various surfactants. • We quantify the volume carry-over of magnetic beads in water and 0.1% triton-X solution.

  20. Liquid carry-over in an injection moulded all-polymer chip system for immiscible phase magnetic bead-based solid-phase extraction

    Science.gov (United States)

    Kistrup, Kasper; Skotte Sørensen, Karen; Wolff, Anders; Fougt Hansen, Mikkel

    2015-04-01

    We present an all-polymer, single-use microfluidic chip system produced by injection moulding and bonded by ultrasonic welding. Both techniques are compatible with low-cost industrial mass-production. The chip is produced for magnetic bead-based solid-phase extraction facilitated by immiscible phase filtration and features passive liquid filling and magnetic bead manipulation using an external magnet. In this work, we determine the system compatibility with various surfactants. Moreover, we quantify the volume of liquid co-transported with magnetic bead clusters from Milli-Q water or a lysis-binding buffer for nucleic acid extraction (0.1 (v/v)% Triton X-100 in 5 M guanidine hydrochloride). A linear relationship was found between the liquid carry-over and mass of magnetic beads used. Interestingly, similar average carry-overs of 1.74(8) nL/μg and 1.72(14) nL/μg were found for Milli-Q water and lysis-binding buffer, respectively.

  1. Parallel simulation of two-phase incompressible and immiscible flows in porous media using a finite volume formulation and a modified IMPES approach

    International Nuclear Information System (INIS)

    Da Silva, R S; De Carvalho, D K E; Antunes, A R E; Lyra, P R M; Willmersdorf, R B

    2010-01-01

    In this paper a finite volume method with a 'Modified Implicit Pressure, Explicit Saturation' (MIMPES) approach is used to model the 3-D incompressible and immiscible two-phase flow of water and oil in heterogeneous and anisotropic porous media. A vertex centered finite volume method with an edge-based data structure is adopted to discretize both the elliptic pressure and the hyperbolic saturation equations using parallel computers with distributed memory. Due to the explicit solution of the saturation equation in the IMPES method, severe time step restrictions are imposed on the simulation. In order to circumvent this problem, an edge-based implementation of the MIMPES method was used. In this method, the pressure equation is solved and the velocity field is computed much less frequently than the saturation field. Following the work of Hurtado, a mean relative variation of the velocity field throughout the simulation is used to automatically control the updating process, allowing for much larger time-steps in a very simple way. In order to run large scale problems, we have developed a parallel implementation using clusters of PC's. The simulator uses open source parallel libraries like FMDB, ParMetis and PETSc. Results of speed-up and efficiency are presented to validate the performance of the parallel simulator.

  2. Low temperature synthesis of CaO-SiO2 glasses having stable liquid-liquid immiscibility by sol-gel process

    Science.gov (United States)

    Bansal, Narottam P.

    1990-01-01

    Calcium silicate glass compositions lying within the liquid-liquid immiscibility dome of the phase diagram, which could not have been prepared by the conventional melting method, were synthesized by the sol-gel process. Hydrolysis and polycondensation of tetraethyl orthosilicate (TEOS) solutions containing up to 20 mol percent calcium nitrate resulted in the formation of clear and transparent gels. The gel formation time decreased with increase in water:TEOS mole ratio, calcium content, and the reaction temperature. Smaller values of gel times in the presence of calcium nitrate are probably caused by lowering of the ionic charge on the sol particles by the salt present. The gelation activation energy, E(sub gel), was evaluated from temperature dependence of the gel time. Presence of Ca(2+) ions or the water:TEOS mole ratio did not have an appreciable effect on the value of E(sub gel). Presence of glycerol in the solution helped in the formation of crack-free monolithic gel specimens. Chemical and structural changes occurring in the gels, as a function of the heat treatments, have been monitored using DTA, TGA, IR-spectroscopy, x ray diffraction, surface area and pore size distribution measurements.

  3. Low temperature synthesis of CaO-SiO2 glasses having stable liquid-liquid immiscibility by the sol-gel process

    Science.gov (United States)

    Bansal, N. P.

    1992-01-01

    Calcium silicate glass compositions lying within the liquid-liquid immiscibility dome of the phase diagram, which could not have been prepared by the conventional melting method, were synthesized by the sol-gel process. Hydrolysis and polycondensation of tetraethyl orthosilicate (TEOS) solutions containing up to 20 mol percent calcium nitrate resulted in the formation of clear and transparent gels. The gel formation time decreased with increase in water: TEOS mole ratio, calcium content, and the reaction temperature. Smaller values of gel times in the presence of calcium nitrate are probably caused by lowering of the ionic charge on the sol particles by the salt present. The gelation activation energy, E(sub gel), was evaluated from temperature dependence of the gel time. Presence of Ca(2+) ions or the water:TEOS mole ratio did not have an appreciable effect on the value of E(sub gel). Presence of glycerol in the solution helped in the formation of crack-free monolithic gel specimens. Chemical and structural changes occurring in the gels, as a function of the heat treatments, have been monitored using DTA, TGA, IR-spectroscopy, X-ray diffraction, surface area and pore size distribution measurements.

  4. Liquid carry-over in an injection moulded all-polymer chip system for immiscible phase magnetic bead-based solid-phase extraction

    International Nuclear Information System (INIS)

    Kistrup, Kasper; Skotte Sørensen, Karen; Wolff, Anders; Fougt Hansen, Mikkel

    2015-01-01

    We present an all-polymer, single-use microfluidic chip system produced by injection moulding and bonded by ultrasonic welding. Both techniques are compatible with low-cost industrial mass-production. The chip is produced for magnetic bead-based solid-phase extraction facilitated by immiscible phase filtration and features passive liquid filling and magnetic bead manipulation using an external magnet. In this work, we determine the system compatibility with various surfactants. Moreover, we quantify the volume of liquid co-transported with magnetic bead clusters from Milli-Q water or a lysis-binding buffer for nucleic acid extraction (0.1 (v/v)% Triton X-100 in 5 M guanidine hydrochloride). A linear relationship was found between the liquid carry-over and mass of magnetic beads used. Interestingly, similar average carry-overs of 1.74(8) nL/µg and 1.72(14) nL/µg were found for Milli-Q water and lysis-binding buffer, respectively. - Highlights: • We present an all-polymer mass producible passive filled microfluidic chip system. • Rapid system fabrication is obtained by injection moulding and ultrasonic welding. • The system is made for single-use nucleic acid extraction using magnetic beads. • We systematically map compatibility of the chip system with various surfactants. • We quantify the volume carry-over of magnetic beads in water and 0.1% triton-X solution

  5. Study of immiscibilities in the trilaurylamine - dodecane - nitric acid - plutonium system; Etude des immiscibilites dans le systeme trilaurylamine - dodecane - acide nitrique - plutonium

    Energy Technology Data Exchange (ETDEWEB)

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

    1968-07-01

    Phase equilibrium in systems made up of trilaurylamine, dodecane, nitric acid tetravalent plutonium is shown by drawing the triangular diagrams. the study of these diagrams provides informations concerning the causes of immiscibility. Heterogeneity of the organic mixtures can be related to some characteristics of the components- dipole moment, molecular polarizability and hydrogen bond exchanging ability-Depending on these, some rules may be established which can be used to make a proper choice of an additive in order to improve the miscibility. As an application a study on the partial substitution of dodecane with decalin, in plutonium extraction experiments, has been done showing a possible improvement of the extraction process. (author) [French] L equilibre des phases dans les systemes formes a partir de trilaurylamine, de dodecane, d'acide nitrique et de plutonium tetravalent est represente en tracant les diagrammes triangulaires. L'examen de ces diagrammes permet d'apporter certaines precisions en ce qui concerne l'origine des immiscibilites. Celles ci sont ensuite reliees a certaines caracteristiques des constituants: le moment dipolaire, la polarisabilite moleculaire et la tendance a former des liaisons hydrogene. Sur les memes bases, il est possible d'etablir un certain nombre de regles pouvant servir a guider le choix d'un additif ameliorant la miscibilite. En application, une etude sur le remplacement partiel du dodecane par la decaline montre l'interet de l'emploi de ce compose dans le procede de purification du plutonium. (auteur)

  6. Numerical investigation of the deformation mechanism of a bubble or a drop rising or falling in another fluid

    International Nuclear Information System (INIS)

    Wang Han; Yang Yongming; Hu Yüe; Zhang Huisheng; Zhang Zhenyu

    2008-01-01

    A numerical method for simulating the motion and deformation of an axisymmetric bubble or drop rising or falling in another infinite and initially stationary fluid is developed based on the volume of fluid (VOF) method in the frame of two incompressible and immiscible viscous fluids under the action of gravity, taking into consideration of surface tension effects. A comparison of the numerical results by this method with those by other works indicates the validity of the method. In the frame of inviscid and incompressible fluids without taking into consideration of surface tension effects, the mechanisms of the generation of the liquid jet and the transition from spherical shape to toroidal shape during the bubble or drop deformation, the increase of the ring diameter of the toroidal bubble or drop and the decrease of its cross-section area during its motion, and the effects of the density ratio of the two fluids on the deformation of the bubble or drop are analysed both theoretically and numerically. (condensed matter: structure, thermal and mechanical properties)

  7. Metalworking and machining fluids

    Science.gov (United States)

    Erdemir, Ali; Sykora, Frank; Dorbeck, Mark

    2010-10-12

    Improved boron-based metal working and machining fluids. Boric acid and boron-based additives that, when mixed with certain carrier fluids, such as water, cellulose and/or cellulose derivatives, polyhydric alcohol, polyalkylene glycol, polyvinyl alcohol, starch, dextrin, in solid and/or solvated forms result in improved metalworking and machining of metallic work pieces. Fluids manufactured with boric acid or boron-based additives effectively reduce friction, prevent galling and severe wear problems on cutting and forming tools.

  8. Disposing of fluid wastes

    International Nuclear Information System (INIS)

    Bradley, J.S.

    1984-01-01

    Toxic liquid waste, eg liquid radioactive waste, is disposed of by locating a sub-surface stratum which, before removal of any fluid, has a fluid pressure in the pores thereof which is less than the hydrostatic pressure which is normal for a stratum at that depth in the chosen area, and then feeding the toxic liquid into the stratum at a rate such that the fluid pressure in the stratum never exceeds the said normal hydrostatic pressure. (author)

  9. Fluid dynamics transactions

    CERN Document Server

    Fiszdon, W

    1965-01-01

    Fluid Dynamics Transactions, Volume 2 compiles 46 papers on fluid dynamics, a subdiscipline of fluid mechanics that deals with fluid flow. The topics discussed in this book include developments in interference theory for aeronautical applications; diffusion from sources in a turbulent boundary layer; unsteady motion of a finite wing span in a compressible medium; and wall pressure covariance and comparison with experiment. The certain classes of non-stationary axially symmetric flows in magneto-gas-dynamics; description of the phenomenon of secondary flows in curved channels by means of co

  10. Electrorheological fluids and methods

    Science.gov (United States)

    Green, Peter F.; McIntyre, Ernest C.

    2015-06-02

    Electrorheological fluids and methods include changes in liquid-like materials that can flow like milk and subsequently form solid-like structures under applied electric fields; e.g., about 1 kV/mm. Such fluids can be used in various ways as smart suspensions, including uses in automotive, defense, and civil engineering applications. Electrorheological fluids and methods include one or more polar molecule substituted polyhedral silsesquioxanes (e.g., sulfonated polyhedral silsesquioxanes) and one or more oils (e.g., silicone oil), where the fluid can be subjected to an electric field.

  11. Plasmas and fluids

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

    Plasma and fluid physics includes the fields of fusion research and space investigation. This book discusses the most important advances in these areas over the past decade and recommends a stronger commitment to basic research in plasma and fluid physics. The book recommends that plasma and fluid physics be included in physics curriculums because of their increasing importance in energy and defense. The book also lists recent accomplishments in the fields of general plasma physics, fusion plasma confinement and heating, space and astrophysical plasmas, and fluid physics and lists research opportunities in these areas. A funding summary explains how research monies are allocated and suggests ways to improve their effectiveness

  12. Theoretical Fluid Dynamics

    CERN Document Server

    Shivamoggi, Bhimsen K

    1998-01-01

    "Although there are many texts and monographs on fluid dynamics, I do not know of any which is as comprehensive as the present book. It surveys nearly the entire field of classical fluid dynamics in an advanced, compact, and clear manner, and discusses the various conceptual and analytical models of fluid flow." - Foundations of Physics on the first edition. Theoretical Fluid Dynamics functions equally well as a graduate-level text and a professional reference. Steering a middle course between the empiricism of engineering and the abstractions of pure mathematics, the author focuses

  13. Three dimensional multi-pass repair weld simulations

    International Nuclear Information System (INIS)

    Elcoate, C.D.; Dennis, R.J.; Bouchard, P.J.; Smith, M.C.

    2005-01-01

    Full 3-dimensional (3-D) simulation of multi-pass weld repairs is now feasible and practical given the development of improved analysis tools and significantly greater computer power. This paper presents residual stress results from 3-D finite element (FE) analyses simulating a long (arc length of 62 deg. ) and a short (arc length of 20 deg. ) repair to a girth weld in a 19.6 mm thick, 432 mm outer diameter cylindrical test component. Sensitivity studies are used to illustrate the importance of weld bead inter-pass temperature assumptions and to show where model symmetry can be used to reduce the analysis size. The predicted residual stress results are compared with measured axial, hoop and radial through-wall profiles in the heat affected zone of the test component repairs. A good overall agreement is achieved between neutron diffraction and deep hole drilling measurements and the prediction at the mid-length position of the short repair. These results demonstrate that a coarse 3-D FE model, using a 'block-dumped' weld bead deposition approach (rather than progressively depositing weld metal), can accurately capture the important components of a short repair weld residual stress field. However, comparisons of measured with predicted residual stress at mid-length and stop-end positions in the long repair are less satisfactory implying some shortcomings in the FE modelling approach that warrant further investigation

  14. Tools for PV (photovoltaic) plant operators: Nowcasting of passing clouds

    International Nuclear Information System (INIS)

    Paulescu, Marius; Badescu, Viorel; Brabec, Marek

    2013-01-01

    The response time of a PV (photovoltaic) plant is very short and its output power follows the abrupt change in solar irradiance level due to alternate shadow by clouds. The sunshine number (SSN) is a Boolean quantity stating whether the sun is covered by clouds or not, thus being an appropriate parameter to predict the occurrence of direct solar radiation at ground level. Various ARIMA (Autoregressive Integrated Moving Average) models for SSN nowcasting are inferred and discussed in this paper. Actinometric and meteorological data measured at 15 s lag during June 2010 in Timisoara (Romania) are used. The forecasting accuracy is studied as a function of season, of the procedure used to obtain a binary time series and of the type of white noise distribution, respectively. It is demonstrated that the ARIMA(0,1,0) model forecasts SSN with the same accuracy as higher order ARIMA models. The forecasting accuracy decreases when the instability of the radiative regime increases. - Highlights: • Nowcasting of passing clouds is modeled by using a 15 s lag database. • ARIMA (Autoregressive Integrated Moving Average) (0,1,0) model is mostly recommended for nowcasting of passing clouds. • Models accuracy increases by increasing the radiative regime stability

  15. PASS: a component of Desk Top PA for the WIPP

    International Nuclear Information System (INIS)

    Crawford, M.B.; Wilmot, R.D.; Galson, D.A.; Swift, P.N.; Fewell, M.E.

    1998-01-01

    There is a growing recognition internationally of the need to demonstrate comprehensiveness in order to build confidence in performance assessments (PAs) for radioactive waste disposal projects. This has resulted in a number of methodologies being developed to formalize the process of defining and documenting the decision basis that underlies a PA. Such methodologies include process influence diagrams and the rock engineering system (RES) matrix. However, these methodologies focus mainly on the conceptualization of the disposal system and do not provide a ready framework to document the decisions behind the model development and parameterization of the PA system. The Performance Assessment Support System (PASS) is a flexible electronic tool designed to increase the transparency and traceability of decision making in the entire PA process. An application of PASS has been developed for the Waste Isolation Pilot Plant (WIPP) where it forms an important component of Desk Top PA, a PC-based PA computational environment under development at Sandia National Laboratories to document, plan, and support management decisions and to assess performance for the WIPP recertification process. This desk-top PA environment is also aimed at providing scientifically-based decision support for assessing the performance of nuclear and hazardous waste management and environmental clean-up systems

  16. Drying of carrot slices in a triple pass solar dryer

    Directory of Open Access Journals (Sweden)

    Seshachalam Kesavan

    2017-01-01

    Full Text Available An indirect triple pass forced convection solar dryer was developed and its performance was evaluated for drying of carrot slices. The drying experiments were carried out under the meteorological conditions of Coimbatore city in India during the year 2016. The experimental set-up consists of a blower, triple pass packed bed air collector (using sand with wire mesh absorber plate, and a drying chamber. The air mass flow rate was optimized to 0.062 kg/s. The initial moisture content of the carrot slices was reduced from 87.5% (on wet basis to the final moisture content of 10% (wet basis in 6 h duration. The thin layer drying characteristics were analyzed using twelve mathematical models available in open literature. The results showed that the pick-up efficiency of the dryer was varied in the range between 14 and 43% with an average air collector thermal efficiency of 44% during the experimentation. The drying characteristics of carrot slices was predicted with good degree of accuracy using Wang and Singh drying model.

  17. Fluid mechanics of Windkessel effect.

    Science.gov (United States)

    Mei, C C; Zhang, J; Jing, H X

    2018-01-08

    We describe a mechanistic model of Windkessel phenomenon based on the linear dynamics of fluid-structure interactions. The phenomenon has its origin in an old-fashioned fire-fighting equipment where an air chamber serves to transform the intermittent influx from a pump to a more steady stream out of the hose. A similar mechanism exists in the cardiovascular system where blood injected intermittantly from the heart becomes rather smooth after passing through an elastic aorta. In existing haeodynamics literature, this mechanism is explained on the basis of electric circuit analogy with empirical impedances. We present a mechanistic theory based on the principles of fluid/structure interactions. Using a simple one-dimensional model, wave motion in the elastic aorta is coupled to the viscous flow in the rigid peripheral artery. Explicit formulas are derived that exhibit the role of material properties such as the blood density, viscosity, wall elasticity, and radii and lengths of the vessels. The current two-element model in haemodynamics is shown to be the limit of short aorta and low injection frequency and the impedance coefficients are derived theoretically. Numerical results for different aorta lengths and radii are discussed to demonstrate their effects on the time variations of blood pressure, wall shear stress, and discharge. Graphical Abstract A mechanistic analysis of Windkessel Effect is described which confirms theoretically the well-known feature that intermittent influx becomes continuous outflow. The theory depends only on the density and viscosity of the blood, the elasticity and dimensions of the vessel. Empirical impedence parameters are avoided.

  18. Fluid Dynamics of Carbon Dioxide Disposal into Saline Aquifers

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Julio Enrique [Univ. of California, Berkeley, CA (United States)

    2003-01-01

    Injection of carbon dioxide (CO2) into saline aquifers has been proposed as a means to reduce greenhouse gas emissions (geological carbon sequestration). Large-scale injection of CO2 will induce a variety of coupled physical and chemical processes, including multiphase fluid flow, fluid pressurization and changes in effective stress, solute transport, and chemical reactions between fluids and formation minerals. This work addresses some of these issues with special emphasis given to the physics of fluid flow in brine formations. An investigation of the thermophysical properties of pure carbon dioxide, water and aqueous solutions of CO2 and NaCl has been conducted. As a result, accurate representations and models for predicting the overall thermophysical behavior of the system CO2-H2O-NaCl are proposed and incorporated into the numerical simulator TOUGH2/ECO2. The basic problem of CO2 injection into a radially symmetric brine aquifer is used to validate the results of TOUGH2/ECO2. The numerical simulator has been applied to more complex flow problem including the CO2 injection project at the Sleipner Vest Field in the Norwegian sector of the North Sea and the evaluation of fluid flow dynamics effects of CO2 injection into aquifers. Numerical simulation results show that the transport at Sleipner is dominated by buoyancy effects and that shale layers control vertical migration of CO2. These results are in good qualitative agreement with time lapse surveys performed at the site. High-resolution numerical simulation experiments have been conducted to study the onset of instabilities (viscous fingering) during injection of CO2 into saline aquifers. The injection process can be classified as immiscible displacement of an aqueous phase by a less dense and less viscous gas phase. Under disposal conditions (supercritical CO2) the viscosity of carbon

  19. Space Station fluid management logistics

    Science.gov (United States)

    Dominick, Sam M.

    1990-01-01

    Viewgraphs and discussion on space station fluid management logistics are presented. Topics covered include: fluid management logistics - issues for Space Station Freedom evolution; current fluid logistics approach; evolution of Space Station Freedom fluid resupply; launch vehicle evolution; ELV logistics system approach; logistics carrier configuration; expendable fluid/propellant carrier description; fluid carrier design concept; logistics carrier orbital operations; carrier operations at space station; summary/status of orbital fluid transfer techniques; Soviet progress tanker system; and Soviet propellant resupply system observations.

  20. Time-varying exchange rate pass-through: experiences of some industrial countries

    OpenAIRE

    Toshitaka Sekine

    2006-01-01

    This paper estimates exchange rate pass-through of six major industrial countries using a time-varying parameter with stochastic volatility model. Exchange rate pass-through is divided into impacts of exchange rate fluctuations to import prices (first-stage pass-through) and those of import price movements to consumer prices (second-stage pass-through). The paper finds that both stages of pass-through have declined over time for all the sample countries. The decline in second-stage pass-throu...

  1. An Introduction to Computational Fluid Mechanics by Example

    CERN Document Server

    Biringen, Sedat

    2011-01-01

    This new book builds on the original classic textbook entitled: An Introduction to Computational Fluid Mechanics by C. Y. Chow which was originally published in 1979. In the decades that have passed since this book was published the field of computational fluid dynamics has seen a number of changes in both the sophistication of the algorithms used but also advances in the computer hardware and software available. This new book incorporates the latest algorithms in the solution techniques and supports this by using numerous examples of applications to a broad range of industries from mechanical

  2. Fluid dynamics of Ribbed Annuli

    International Nuclear Information System (INIS)

    McCreery, G. E.; Pink, R. J.; Condie, K. G.; McEligot, D. M.

    2003-01-01

    Typical advanced gas-cooled reactor designs use periodic spacer ribs to center rods in circular cooling channels, e.g., as for control rods (General Atomics and others) and fuel rods (HTTR). In contrast to classical studies of axisymmetric annuli, the flow becomes three-dimensional but is typically periodic in the circumferential direction and - in some cases - in the streamwise direction. Fundamental measurements have been obtained for two idealizations of these complex geometries: an annulus with three ribs circumferentially and one with four. Laser Doppler Velocimetry (LDV) was employed with INEEL's unique Matched-Index-of-Refraction (MIR) flow facility to determine the velocity and turbulence fields. The initial experiment was aimed at obtaining benchmark data to test the capabilities of CFD (Computational Fluid Dynamics) codes to handle ribbed annular geometries without the complications of turbulent transport. The Reynolds number was about 1120. These conditions correspond to some stages during a pressurized cooldown (LOFA) event. Power spectral densities were obtained to determine the eddy shedding frequency downstream of the ribs. For the second experiment LDV measurements were obtained in another ribbed-annular model at a higher flow rate. For this nominally turbulent flow, evidence of laminarization appears in the flow converging to pass between ribs. The measurements indicated flow details which could be useful for assessment of CFD codes

  3. Compressible generalized Newtonian fluids

    Czech Academy of Sciences Publication Activity Database

    Málek, Josef; Rajagopal, K.R.

    2010-01-01

    Roč. 61, č. 6 (2010), s. 1097-1110 ISSN 0044-2275 Institutional research plan: CEZ:AV0Z20760514 Keywords : power law fluid * uniform temperature * compressible fluid Subject RIV: BJ - Thermodynamics Impact factor: 1.290, year: 2010

  4. Pleural fluid smear

    Science.gov (United States)

    ... into the space around the lungs, called the pleural space. As fluid drains into a collection bottle, you may cough a bit. This is because your lung re-expands to fill the space where fluid had been. This sensation lasts for a few hours after the test.

  5. Peritoneal fluid culture

    Science.gov (United States)

    Culture - peritoneal fluid ... sent to the laboratory for Gram stain and culture. The sample is checked to see if bacteria ... The peritoneal fluid culture may be negative, even if you have ... diagnosis of peritonitis is based on other factors, in addition ...

  6. Tumor interstitial fluid

    DEFF Research Database (Denmark)

    Gromov, Pavel; Gromova, Irina; Olsen, Charlotta J.

    2013-01-01

    Tumor interstitial fluid (TIF) is a proximal fluid that, in addition to the set of blood soluble phase-borne proteins, holds a subset of aberrantly externalized components, mainly proteins, released by tumor cells and tumor microenvironment through various mechanisms, which include classical...

  7. Fluid control valves

    International Nuclear Information System (INIS)

    Rankin, J.

    1980-01-01

    A fluid control valve is described in which it is not necessary to insert a hand or a tool into the housing to remove the valve seat. Such a valve is particularly suitable for the control of radioactive fluids since maintenance by remote control is possible. (UK)

  8. Time Independent Fluids

    Science.gov (United States)

    Collyer, A. A.

    1973-01-01

    Discusses theories underlying Newtonian and non-Newtonian fluids by explaining flow curves exhibited by plastic, shear-thining, and shear-thickening fluids and Bingham plastic materials. Indicates that the exact mechanism governing shear-thickening behaviors is a problem of further study. (CC)

  9. Relativistic thermodynamics of fluids

    International Nuclear Information System (INIS)

    Souriau, J.-M.

    1977-05-01

    The relativistic covariant definition of a statistical equilibrium, applied to a perfect gas, involves a 'temperature four-vector', whose direction is the mean velocity of the fluid, and whose length is the reciprocal temperature. The hypothesis of this 'temperature four-vector' being a relevant variable for the description of the dissipative motions of a simple fluid is discussed. The kinematics is defined by using a vector field and measuring the number of molecules. Such a dissipative fluid is subject to motions involving null entropy generation; the 'temperature four-vector' is then a Killing vector; the equations of motion can be completely integrated. Perfect fluids can be studied by this way and the classical results of Lichnerowicz are obtained. In weakly dissipative motions two viscosity coefficient appear together with the heat conductibility coefficient. Two other coefficients perharps measurable on real fluids. Phase transitions and shock waves are described with using the model [fr

  10. All-Pass Filter Based Linear Voltage Controlled Quadrature Oscillator

    Directory of Open Access Journals (Sweden)

    Koushick Mathur

    2017-01-01

    Full Text Available A linear voltage controlled quadrature oscillator implemented from a first-order electronically tunable all-pass filter (ETAF is presented. The active element is commercially available current feedback amplifier (AD844 in conjunction with the relatively new Multiplication Mode Current Conveyor (MMCC device. Electronic tunability is obtained by the control node voltage (V of the MMCC. Effects of the device nonidealities, namely, the parasitic capacitors and the roll-off poles of the port-transfer ratios of the device, are shown to be negligible, even though the usable high-frequency ranges are constrained by these imperfections. Subsequently the filter is looped with an electronically tunable integrator (ETI to implement the quadrature oscillator (QO. Experimental responses on the voltage tunable phase of the filter and the linear-tuning law of the quadrature oscillator up to 9.9 MHz at low THD are verified by simulation and hardware tests.

  11. Complete genes may pass from food to human blood

    DEFF Research Database (Denmark)

    Spisák, Sándor; Solymosi, Norbert; Ittzés, Péter

    2013-01-01

    Our bloodstream is considered to be an environment well separated from the outside world and the digestive tract. According to the standard paradigm large macromolecules consumed with food cannot pass directly to the circulatory system. During digestion proteins and DNA are thought to be degraded...... into small constituents, amino acids and nucleic acids, respectively, and then absorbed by a complex active process and distributed to various parts of the body through the circulation system. Here, based on the analysis of over 1000 human samples from four independent studies, we report evidence that meal......-derived DNA fragments which are large enough to carry complete genes can avoid degradation and through an unknown mechanism enter the human circulation system. In one of the blood samples the relative concentration of plant DNA is higher than the human DNA. The plant DNA concentration shows a surprisingly...

  12. Public-channel cryptography based on mutual chaos pass filters.

    Science.gov (United States)

    Klein, Einat; Gross, Noam; Kopelowitz, Evi; Rosenbluh, Michael; Khaykovich, Lev; Kinzel, Wolfgang; Kanter, Ido

    2006-10-01

    We study the mutual coupling of chaotic lasers and observe both experimentally and in numeric simulations that there exists a regime of parameters for which two mutually coupled chaotic lasers establish isochronal synchronization, while a third laser coupled unidirectionally to one of the pair does not synchronize. We then propose a cryptographic scheme, based on the advantage of mutual coupling over unidirectional coupling, where all the parameters of the system are public knowledge. We numerically demonstrate that in such a scheme the two communicating lasers can add a message signal (compressed binary message) to the transmitted coupling signal and recover the message in both directions with high fidelity by using a mutual chaos pass filter procedure. An attacker, however, fails to recover an errorless message even if he amplifies the coupling signal.

  13. Milestone experiments for single pass UV/X-ray FELs

    International Nuclear Information System (INIS)

    Ben-Zvi, I.

    1994-01-01

    In the past decade, significant advances have been made in the theory and technology of high brightness electron beams and single pass FELS. These developments facilitate the construction of practical UV and X-ray FELs and has prompted proposals to the DOE for the construction of such facilities. There are several important experiments to be performed before committing to the construction of dedicated user facilities. Two experiments are under construction in the IR, the UCLA Self Amplified Spontaneous Emission experiment and the BNL laser seeded Harmonic Generation experiment. A multi-institution collaboration is being organized about a 210 MeV electron linac available at BNL and the 10 meter tong NISUS wiggler. This experiment will be done in the UV and will test various experimental aspects of electron beam dynamics, FEL exponential regime with gain guiding, start up from noise, seeding and harmonic generation. These experiments will advance the state of FEL research and lead towards future dedicated users' facilities

  14. Solidify, An LLVM pass to compile LLVM IR into Solidity

    Energy Technology Data Exchange (ETDEWEB)

    2017-07-12

    The software currently compiles LLVM IR into Solidity (Ethereum’s dominant programming language) using LLVM’s pass library. Specifically, his compiler allows us to convert an arbitrary DSL into Solidity. We focus specifically on converting Domain Specific Languages into Solidity due to their ease of use, and provable properties. By creating a toolchain to compile lightweight domain-specific languages into Ethereum's dominant language, Solidity, we allow non-specialists to effectively develop safe and useful smart contracts. For example lawyers from a certain firm can have a proprietary DSL that codifies basic laws safely converted to Solidity to be securely executed on the blockchain. In another example, a simple provenance tracking language can be compiled and securely executed on the blockchain.

  15. Study of charge exchanges of heavy ions passing through solids

    International Nuclear Information System (INIS)

    Baron, Eric.

    1975-01-01

    The charge state distributions of 1 to 6MeV/nucleon heavy ions (from oxygen to krypton) passing through thin targets of various materials (C, Cu, Ag, Au) are studied. The variation of the average charge state and of the charge state fractions as a function of the thickness of carbon targets ranging from zero to the equilibrium thickness is measured; this allows the calculation of effective cross-sections of the charge changing process. It is also shown that the lower the target atomic number, the higher the average charge state, which is explained by a decrease of the capture cross sections. Finally, a semi-empirical formula predicting the average charge state is proposed, as an extension of Betz's and Nikolaev and Dmitriev's formula [fr

  16. Parallelization of a hydrological model using the message passing interface

    Science.gov (United States)

    Wu, Yiping; Li, Tiejian; Sun, Liqun; Chen, Ji

    2013-01-01

    With the increasing knowledge about the natural processes, hydrological models such as the Soil and Water Assessment Tool (SWAT) are becoming larger and more complex with increasing computation time. Additionally, other procedures such as model calibration, which may require thousands of model iterations, can increase running time and thus further reduce rapid modeling and analysis. Using the widely-applied SWAT as an example, this study demonstrates how to parallelize a serial hydrological model in a Windows® environment using a parallel programing technology—Message Passing Interface (MPI). With a case study, we derived the optimal values for the two parameters (the number of processes and the corresponding percentage of work to be distributed to the master process) of the parallel SWAT (P-SWAT) on an ordinary personal computer and a work station. Our study indicates that model execution time can be reduced by 42%–70% (or a speedup of 1.74–3.36) using multiple processes (two to five) with a proper task-distribution scheme (between the master and slave processes). Although the computation time cost becomes lower with an increasing number of processes (from two to five), this enhancement becomes less due to the accompanied increase in demand for message passing procedures between the master and all slave processes. Our case study demonstrates that the P-SWAT with a five-process run may reach the maximum speedup, and the performance can be quite stable (fairly independent of a project size). Overall, the P-SWAT can help reduce the computation time substantially for an individual model run, manual and automatic calibration procedures, and optimization of best management practices. In particular, the parallelization method we used and the scheme for deriving the optimal parameters in this study can be valuable and easily applied to other hydrological or environmental models.

  17. A numerical performance assessment of a commercial cardiopulmonary by-pass blood heat exchanger.

    Science.gov (United States)

    Consolo, Filippo; Fiore, Gianfranco B; Pelosi, Alessandra; Reggiani, Stefano; Redaelli, Alberto

    2015-06-01

    We developed a numerical model, based on multi-physics computational fluid dynamics (CFD) simulations, to assist the design process of a plastic hollow-fiber bundle blood heat exchanger (BHE) integrated within the INSPIRE(TM), a blood oxygenator (OXY) for cardiopulmonary by-pass procedures, recently released by Sorin Group Italia. In a comparative study, we analyzed five different geometrical design solutions of the BHE module. Quantitative geometrical-dependent parameters providing a comprehensive evaluation of both the hemo- and thermo-dynamics performance of the device were extracted to identify the best-performing prototypical solution. A convenient design configuration was identified, characterized by (i) a uniform blood flow pattern within the fiber bundle, preventing blood flow shunting and the onset of stagnation/recirculation areas and/or high velocity pathways, (ii) an enhanced blood heating efficiency, and (iii) a reduced blood pressure drop. The selected design configuration was then prototyped and tested to experimentally characterize the device performance. Experimental results confirmed numerical predictions, proving the effectiveness of CFD modeling as a reliable tool for in silico identification of suitable working conditions of blood handling medical devices. Notably, the numerical approach limited the need for extensive prototyping, thus reducing the corresponding machinery costs and time-to-market. Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.

  18. Optimum Energy Extraction from Coherent Vortex Rings Passing Tangentially Over Flexible Plates

    Science.gov (United States)

    Pirnia, Alireza; Browning, Emily A.; Peterson, Sean D.; Erath, Byron D.

    2017-11-01

    Coherent vortical structures can incite self-sustained oscillations in flexible membranes. This concept has recently gained interest for energy extraction from ambient environments. In this study the special case of a vortex ring passing tangentially over a cantilevered flexible plate is investigated. This problem is governed by the Kirchhoff-Love plate equation, which can be expressed in terms of a non-dimensional mass parameter of the plate, non-dimensional pressure loading induced by the vortex ring, and a Strouhal (St) number which expresses the duration of pressure loading relative to the period of plate oscillation. For a plate with a fixed mass parameter immersed in a fluid environment, the St number specifies the beam dynamics and the energy exchange process. The aim of this study is to identify the St number corresponding to maximum energy exchange between plates and vortex rings. The energy exchange process between the vortex ring and the plate is investigated over a range of 0.3 transfer is reported in each case and an empirical correlation is provided for predictive purposes. Supported by the National Science Foundation (NSF) under Grant No. CBET-1511761, and the Natural Sciences and Engineering Research Council of Canada (NSERC), under Grant No. 05778-2015.

  19. Investigations on the performance of a double pass, hybrid - type (PV/T) solar air heater

    Energy Technology Data Exchange (ETDEWEB)

    Srinivas, M.; Jayaraj, S. [Department of Mechanical Engineering, National Institute of Technology, Calicut-673601 (India)

    2013-07-01

    A solar hybrid energy system having photovoltaic and thermal (PV/T) devices, which produces both thermal and electrical energies simultaneously is considered for analysis. A double pass hybrid solar air (PV/T) heater with slats is designed and fabricated to study its thermal and electrical performance. Air as a heat removing fluid is made to flow through upper and lower channels of the collector. The collector is designed in such a way that the absorber plate is partially covered by solar cells. The raise in temperature of the solar cell is expected to decrease its electrical performance. Thin metallic strips called slats are attached longitudinally at the bottom side of the absorber plate to improve the system performance by increasing the cooling rate of the absorber plate. Thermal and electrical performances of the whole system at varying cooling conditions are presented. An artificial neural network model is used for forecasting the system performance at any desired conditions. The proposed model can be successfully used for evaluating the effect of different operating parameters under different ambient conditions for predicting the overall performance of the system.

  20. Effects of Data Passing Semantics and Operating System Structure on Network I/O Performance

    National Research Council Canada - National Science Library

    Brustoloni, Jose

    1997-01-01

    .... Researchers have often proposed changing the semantics of I/O data passing, so as to make copying unnecessary, or the structure of the operating system, so as to reduce or eliminate data and control passing...

  1. Laser Welding-Brazing of Immiscible AZ31B Mg and Ti-6Al-4V Alloys Using an Electrodeposited Cu Interlayer

    Science.gov (United States)

    Zhang, Zequn; Tan, Caiwang; Wang, Gang; Chen, Bo; Song, Xiaoguo; Zhao, Hongyun; Li, Liqun; Feng, Jicai

    2018-03-01

    Metallurgical bonding between immiscible system AZ31B magnesium (Mg) and Ti-6Al-4V titanium (Ti) was achieved by adding Cu interlayer using laser welding-brazing process. Effect of the laser power on microstructure evolution and mechanical properties of Mg/Cu-coated Ti joints was studied. Visually acceptable joints were obtained at the range of 1300 to 1500 W. The brazed interface was divided into three parts due to temperature gradient: direct irradiation zone, intermediate zone and seam head zone. Ti3Al phase was produced along the interface at the direct irradiation zone. Ti-Al reaction layer grew slightly with the increase in laser power. A small amount of Ti2(Cu,Al) interfacial compounds formed at the intermediate zone and the ( α-Mg + Mg2Cu) eutectic structure dispersed in the fusion zone instead of gathering when increasing the laser power at this zone. At the seam head zone, Mg-Cu eutectic structure was produced in large quantities under all cases. Joint strength first increased and then decreased with the variation of the laser power. The maximum fracture load of Mg/Cu-coated Ti joint reached 2314 N at the laser power of 1300 W, representing 85.7% joint efficiency when compared with Mg base metal. All specimens fractured at the interface. The feature of fracture surface at the laser power of 1100 W was characterized by overall smooth surface. Obvious tear ridge and Ti3Al particles were observed at the fracture surface with increase in laser power. It suggested atomic diffusion was accelerated with more heat input giving rise to the enhanced interfacial reaction and metallurgical bonding in direct irradiation zone, which determined the mechanical properties of the joint.

  2. Effect of Exfoliated Graphene Nanoplatelets on Rheological, Morphological, Mechanical and Thermal Properties of Immiscible Polypropylene/Polystyrene (PP/PS Blends

    Directory of Open Access Journals (Sweden)

    Fatemeh Abbasi

    2016-11-01

    Full Text Available Polyolefin/polystyrene blends, prepared by mechanical mixing, were immiscible blends having two-phase structure with weak interface. An improvement in compatibility of PP and PS led to their enhanced blend properties and applications. The aim of this study was to investigate the effect of exfoliated graphene nanoplatelets (xGnP on the compatibility of PP/PS (80:20 blend by their rheological and mechanical behaviors. Samples of the blends were prepared using an internal mixer through simultaneous feeding of the components into the mixing chamber. The properties of blends were evaluated by rheometry, scanning electron microscopy (SEM, thermal gravimetric analysis (TGA, differential scanning calorimetry (DSC and mechanical tests. Rheological results showed that addition of xGnP, led to an increase in storage modulus and complex viscosity, especially at low frequencies, probably due to the confinement of polymer chain motions. SEM observations on the morphology of blends revealed that increasing the xGnP content obviously reduced the domain diameter of the dispersed PS phase, indicating a good compatibilizing effect for xGnP. The addition of xGnP into the PP/PS blend increased the tensile modulus and decreased the elongation-at-break, resulting from the rigidity and intrinsic mechanical characteristics of the grapheme nanoplatelets. Crystallinity of the samples also increased with higher xGnP content, which could be assigned to the nucleating effect of graphene platelets. Moreover, thermal stability of the blends were improved by increasing the xGnP level because xGnP as an efficient compatibilizing agent with high thermal conductivity provided a more uniform heat distribution profile.

  3. Fluid sampling tool

    Science.gov (United States)

    Garcia, A.R.; Johnston, R.G.; Martinez, R.K.

    1999-05-25

    A fluid sampling tool is described for sampling fluid from a container. The tool has a fluid collecting portion which is drilled into the container wall, thereby affixing it to the wall. The tool may have a fluid extracting section which withdraws fluid collected by the fluid collecting section. The fluid collecting section has a fluted shank with an end configured to drill a hole into a container wall. The shank has a threaded portion for tapping the borehole. The shank is threadably engaged to a cylindrical housing having an inner axial passageway sealed at one end by a septum. A flexible member having a cylindrical portion and a bulbous portion is provided. The housing can be slid into an inner axial passageway in the cylindrical portion and sealed to the flexible member. The bulbous portion has an outer lip defining an opening. The housing is clamped into the chuck of a drill, the lip of the bulbous section is pressed against a container wall until the shank touches the wall, and the user operates the drill. Wall shavings (kerf) are confined in a chamber formed in the bulbous section as it folds when the shank advances inside the container. After sufficient advancement of the shank, an o-ring makes a seal with the container wall. 6 figs.

  4. Fluid mechanics. Vol. 2

    International Nuclear Information System (INIS)

    Truckenbrodt, E.

    1980-01-01

    The second volume contains the chapter 4 to 6. Whereas chapter 1 deals with the introduction into the mechanics of fluids and chapter 2 with the fundamental laws of fluid and thermal fluid dynamics, in chapter 3 elementary flow phenomena in fluids with constant density are treated. Chapter 4 directly continues chapter 3 and describes elementary flow phenomena in fluids with varying density. Fluid statics again is treated as a special case. If compared with the first edition the treatment of unsteady laminar flow and of pipe flow for a fluid with varying density were subject to a substantial extension. In chapter 5 rotation-free and rotating potential flows are presented together. By this means it is achieved to explain the behaviour of the multidimensional fictionless flow in closed form. A subchapter describes some related problems of potential theory like the flow along a free streamline and seepage flow through a porous medium. The boundary layer flows in chapter 6 are concerned with the flow and temperature boundary layer in laminar and turbulent flows at a fired wall. In it differential and integral methods are applied of subchapter reports on boundary layer flows without a fixed boundary, occurring e.g. in an open jet and in a wake flow. The problems of intermittence and of the Coanda effect are briefly mentioned. (orig./MH)

  5. Fluid sampling tool

    Science.gov (United States)

    Garcia, Anthony R.; Johnston, Roger G.; Martinez, Ronald K.

    1999-05-25

    A fluid sampling tool for sampling fluid from a container. The tool has a fluid collecting portion which is drilled into the container wall, thereby affixing it to the wall. The tool may have a fluid extracting section which withdraws fluid collected by the fluid collecting section. The fluid collecting section has a fluted shank with an end configured to drill a hole into a container wall. The shank has a threaded portion for tapping the borehole. The shank is threadably engaged to a cylindrical housing having an inner axial passageway sealed at one end by a septum. A flexible member having a cylindrical portion and a bulbous portion is provided. The housing can be slid into an inner axial passageway in the cylindrical portion and sealed to the flexible member. The bulbous portion has an outer lip defining an opening. The housing is clamped into the chuck of a drill, the lip of the bulbous section is pressed against a container wall until the shank touches the wall, and the user operates the drill. Wall shavings (kerf) are confined in a chamber formed in the bulbous section as it folds when the shank advances inside the container. After sufficient advancement of the shank, an o-ring makes a seal with the container wall.

  6. FRACTURING FLUID CHARACTERIZATION FACILITY

    Energy Technology Data Exchange (ETDEWEB)

    Subhash Shah

    2000-08-01

    Hydraulic fracturing technology has been successfully applied for well stimulation of low and high permeability reservoirs for numerous years. Treatment optimization and improved economics have always been the key to the success and it is more so when the reservoirs under consideration are marginal. Fluids are widely used for the stimulation of wells. The Fracturing Fluid Characterization Facility (FFCF) has been established to provide the accurate prediction of the behavior of complex fracturing fluids under downhole conditions. The primary focus of the facility is to provide valuable insight into the various mechanisms that govern the flow of fracturing fluids and slurries through hydraulically created fractures. During the time between September 30, 1992, and March 31, 2000, the research efforts were devoted to the areas of fluid rheology, proppant transport, proppant flowback, dynamic fluid loss, perforation pressure losses, and frictional pressure losses. In this regard, a unique above-the-ground fracture simulator was designed and constructed at the FFCF, labeled ''The High Pressure Simulator'' (HPS). The FFCF is now available to industry for characterizing and understanding the behavior of complex fluid systems. To better reflect and encompass the broad spectrum of the petroleum industry, the FFCF now operates under a new name of ''The Well Construction Technology Center'' (WCTC). This report documents the summary of the activities performed during 1992-2000 at the FFCF.

  7. Exchange rate pass-through and the role of international distribution channels

    OpenAIRE

    Desiraju, Ramarao; Shrikhande, Milind

    1996-01-01

    Manufacturers selling in foreign markets often do not completely pass on the effects of fluctuations in exchange rates to the prices of their products. Our paper addresses this puzzle and studies the effects of the international distribution channel on exchange rate pass-through. We develop an exchange rate pass-through model that takes into account the role of an intermediary between a domestic manufacturer and its consumers in a foreign market. We find that the magnitude of the pass-through...

  8. Estimating the Exchange Rate Pass-Through to Prices in Mexico

    OpenAIRE

    Josué Fernando Cortés Espada

    2013-01-01

    This paper estimates the magnitude of the exchange rate pass-through to consumer prices in Mexico. Moreover, it analyzes if the pass-through dynamics have changed in recent years. In particular, it uses a methodology that generates results consistent with the hierarchy implicit in the cpi. The results suggest that the exchange rate pass-through to the general price level is low and not statistically significant. However, the pass-through is positive and significant for goods prices. Furthermo...

  9. An estimation of the exchange rate pass-through to prices in Mexico

    OpenAIRE

    Josué Fernando Cortés Espada

    2013-01-01

    This paper estimates the magnitude of the exchange rate pass-through to consumer prices in Mexico. Moreover, it analyzes if the pass-through dynamics have changed in recent years. In particular, it uses a methodology that generates results consistent with the hierarchy implicit in the CPI. The results suggest that the exchange rate pass-through to the general price level is low and not statistically significant. However, the pass-through is positive and significant for goods prices. Furthermo...

  10. Thermodynamics of Fluid Polyamorphism

    Directory of Open Access Journals (Sweden)

    Mikhail A. Anisimov

    2018-01-01

    Full Text Available Fluid polyamorphism is the existence of different condensed amorphous states in a single-component fluid. It is either found or predicted, usually at extreme conditions, for a broad group of very different substances, including helium, carbon, silicon, phosphorous, sulfur, tellurium, cerium, hydrogen, and tin tetraiodide. This phenomenon is also hypothesized for metastable and deeply supercooled water, presumably located a few degrees below the experimental limit of homogeneous ice formation. We present a generic phenomenological approach to describe polyamorphism in a single-component fluid, which is completely independent of the molecular origin of the phenomenon. We show that fluid polyamorphism may occur either in the presence or in the absence of fluid phase separation depending on the symmetry of the order parameter. In the latter case, it is associated with a second-order transition, such as in liquid helium or liquid sulfur. To specify the phenomenology, we consider a fluid with thermodynamic equilibrium between two distinct interconvertible states or molecular structures. A fundamental signature of this concept is the identification of the equilibrium fraction of molecules involved in each of these alternative states. However, the existence of the alternative structures may result in polyamorphic fluid phase separation only if mixing of these structures is not ideal. The two-state thermodynamics unifies all the debated scenarios of fluid polyamorphism in different areas of condensed-matter physics, with or without phase separation, and even goes beyond the phenomenon of polyamorphism by generically describing the anomalous properties of fluids exhibiting interconversion of alternative molecular states.

  11. Fluid Dynamics for Physicists

    Science.gov (United States)

    Faber, T. E.

    1995-08-01

    This textbook provides an accessible and comprehensive account of fluid dynamics that emphasizes fundamental physical principles and stresses connections with other branches of physics. Beginning with a basic introduction, the book goes on to cover many topics not typically treated in texts, such as compressible flow and shock waves, sound attenuation and bulk viscosity, solitary waves and ship waves, thermal convection, instabilities, turbulence, and the behavior of anisotropic, non-Newtonian and quantum fluids. Undergraduate or graduate students in physics or engineering who are taking courses in fluid dynamics will find this book invaluable.

  12. Thermal Fluid Engineering

    International Nuclear Information System (INIS)

    Jang, Byeong Ju

    1984-01-01

    This book is made up of 5 chapters. They are fluid mechanics, fluid machines, Industrial thermodynamics, steam boiler and steam turbine. It introduces hydrostatics, basic theory of fluid movement and law of momentum. It also deals with centrifugal pump, axial flow pump, general hydraulic turbine, and all phenomena happening in the pump. It covers the law of thermodynamics, perfect gas, properties of steam, and flow of gas and steam and water tube boiler. Lastly it explains basic format, theory, loss and performance as well as principle part of steam turbine.

  13. Shaping decisions in volleyball An ecological approach to decision-making in volleyball passing

    NARCIS (Netherlands)

    Barsingerhorn, Annemiek D.; Zaal, Frank T. J. M.; De Poel, Harjo J.; Pepping, Gert-Jan

    2013-01-01

    To extend research on decision-making in sport we addressed the choices volleyball-players are faced with in a simple volleyball pass-return task. We manipulated the distance that eight experienced volleyball players had to cover for successful ball passing, and mapped their passing technique (i.e.,

  14. 9 CFR 312.3 - Official marks and devices to identify inspected and passed equine products.

    Science.gov (United States)

    2010-01-01

    ... inspected and passed equine products. 312.3 Section 312.3 Animals and Animal Products FOOD SAFETY AND... § 312.3 Official marks and devices to identify inspected and passed equine products. (a) The official... § 317.2 of this subchapter to identify inspected and passed mule and other (nonhorse) equine carcasses...

  15. Integrated Cu-based TM-pass polarizer using CMOS technology platform

    KAUST Repository

    Ng, Tien Khee; Khan, Mohammed Zahed Mustafa; Ooi, Boon S.

    2010-01-01

    A transverse-magnetic-pass (TM-pass) copper (Cu) polarizer is proposed and analyzed using the previously published two-dimensional Method-of-Lines beam-propagation model. The proposed polarizer exhibits a simulated high-pass filter characteristics

  16. 9 CFR 310.6 - Carcasses and parts passed for cooking; marking.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Carcasses and parts passed for cooking... INSPECTION AND CERTIFICATION POST-MORTEM INSPECTION § 310.6 Carcasses and parts passed for cooking; marking. Carcasses and parts passed for cooking shall be marked conspicuously on the surface tissues thereof by a...

  17. The Effects on Soccer Passing Skills When Warming Up with Two Different Sized Soccer Balls

    Science.gov (United States)

    Burcak, Keskin

    2015-01-01

    The purpose of the present research is studying the effects of warm-up with two different sizes of balls on passing skills. Loughborough Soccer Passing Test (LSPT) was conducted on 28 non-elite football players, who participated in the present research for 10 training days. LSPT is a passing skill protocol established on completing 16 passes…

  18. Affordances shape pass kick behavior in association football : effects of distance and social context

    NARCIS (Netherlands)

    Pepping, Gert-Jan; Heijmerikx, Johan; de Poel, Harjo J.

    2011-01-01

    A prerequisite for accurate passing in association football is that a player perceives the affordances, that is, the opportunities for action, of a given situation. The present study examined how affordances shape passing in association football by comparing the performance of pass-kicks in two task

  19. Interface behavior of a multi-layer fluid configuration subject to acceleration in a microgravity environment, supplement 1. M.S. Thesis

    Science.gov (United States)

    Lyell, M. J.; Roh, Michael

    1991-01-01

    With the increasing opportunities for research in a microgravity environment, there arises a need for understanding fluid mechanics under such conditions. In particular, a number of material processing configurations involve fluid-fluid interfaces which may experience instabilities in the presence of external forcing. In a microgravity environment, these accelerations may be periodic or impulse-type in nature. This research investigates the behavior of a multi-layer idealized fluid configuration which is infinite in extent. The analysis is linear, and each fluid region is considered inviscid, incompressible, and immiscible. An initial parametric study of confiquration stability in the presence of a constant acceleration field is performed. The zero mean gravity limit case serves as the base state for the subsequent time-dependent forcing cases. A stability analysis of the multi-layer fluid system in the presence of periodic forcing is investigated. Floquet theory is utilized. A parameter study is performed, and regions of stability are identified. For the impulse-type forcing case, asymptotic stability is established for the configuration. Using numerical integration, the time response of the interfaces is determined.

  20. Fluids of the lower crust and upper mantle: deep is different

    Science.gov (United States)

    Manning, C. E.

    2017-12-01

    Deep fluids are important for the evolution and properties of the lower crust and upper mantle in tectonically active settings. Uncertainty about their chemistry has led past workers to use upper crustal fluids as analogues. However, recent results show that fluids at >15 km differ fundamentally from shallow fluids and help explain high-pressure metasomatism and resistivity patterns. Deep fluids are comprised of four components: H2O, non-polar gases (chiefly CO2), salts (mostly alkali chlorides), and rock-derived solutes (dominated by aluminosilicates and related components). The first three generally define the solvent properties of the fluid, and models must account for observations that H2O activity may be quite low. The contrasting behavior of H2O-gas and H2O-salt mixtures yields immiscibility in the ternary system, which can lead to separation of two phases with fundamentally different chemical and transport properties. Thermodynamic modeling of equilibrium between rocks and H2O using simple ionic species known from shallow-crustal systems yields solutions possessing total dissolved solids and ionic strength that are too low to be consistent with experiments and resistivity surveys. Addition of CO2 further lowers bulk solubility and conductivity. Therefore, additional species must be present in H2O, and H2O-salt solutions likely explain much of the evidence for fluid action in high-P settings. At low salinity, H2O-rich fluids are powerful solvents for aluminosilicate rock components that are dissolved as previously unrecognized polymerized clusters. Experiments show that, near H2O-saturated melting, Al-Si polymers comprise >80% of solutes. The stability of these species facilitates critical critical mixing in rock-H2O systems. Addition of salt (e.g., NaCl) changes solubility patterns, but aluminosilicate contents remain high. Thermodynamic models indicate that the ionic strength of fluids with Xsalt = 0.05 to 0.4 and equilibrated with model crustal rocks have

  1. Numerical simulation of travelling wave induced electrothermal fluid flow

    International Nuclear Information System (INIS)

    Perch-Nielsen, Ivan R; Green, Nicolas G; Wolff, Anders

    2004-01-01

    Many microdevices for manipulating particles and cells use electric fields to produce a motive force on the particles. The movement of particles in non-uniform electric fields is called dielectrophoresis, and the usual method of applying this effect is to pass the particle suspension over a microelectrode structure. If the suspension has a noticeable conductivity, one important side effect is that the electric field drives a substantial conduction current through the fluid, causing localized Joule-heating. The resulting thermal gradient produces local conductivity and permittivity changes in the fluid. Dielectrophoretic forces acting upon these pockets of fluid will then produce motion of both the fluid and the particles. This paper presents a numerical solution of the electrical force and the resulting electrothermal driven fluid flow on a travelling wave structure. This common electrode geometry consists of interdigitated electrodes laid down in a long array, with the phase of the applied potential shifted by 90 0 on each subsequent electrode. The resulting travelling electric field was simulated and the thermal field and electrical body force on the fluid calculated, for devices constructed from two typical materials: silicon and glass. The electrothermal fluid flow in the electrolyte over the electrode array was then numerically simulated. The model predicts that the thermal field depends on the conductivity and applied voltage, but more importantly on the geometry of the system and the material used in the construction of the device. The velocity of the fluid flow depends critically on the same parameters, with slight differences in the thermal field for glass and silicon leading to diametrically opposite flow direction with respect to the travelling field for the two materials. In addition, the imposition of slight external temperature gradients is shown to have a large effect on the fluid flow in the device, under certain conditions leading to a reversal of

  2. Hydrothermal Fluid evolution in the Dalli porphyry Cu-Au Deposit: Fluid Inclusion microthermometry studies

    Directory of Open Access Journals (Sweden)

    Alireza Zarasvandi

    2015-10-01

    from drill cores DH01, DH02, DH06, and DH07, and outcrop samples. Microthermometric data were obtained by freezing and heating of fluid inclusions on a Linkam THMSG600 mounted on an Olympus microscope at Lorestan University. Results 1 Five main veintypes were identified, belonging to three stages of mineralization:type (I: barren quartz, type (II: quartz + pyrite + chalcopyrite ± bornite ± chalcocite ± covelite, type (III: quartz + magnetite ± chalcopyrite, type (IV: K-feldspar± quartz ± chalcopyrite, type (V: chlorite + biotite. 2 Seven groups of fluid inclusionswere observed: (IA liquid-rich mono-phase, (IB vapor-rich mono-phase, (IIA liquid-rich two-phase (liquid + vapor, (IIB vapor-rich two-phase (vapor + liquid, (IIIA high salinity simple fluids (liquid + vapor + halite, (IIIB high salinity opaque mineral-bearing fluids (liquid + vapor + halite + pyrite + chalcopyrite + hematite, (IIIAB multi-phase fluids (liquid + vapor + halite + sylvite + hematite + magnetite + pyrite + chalcopyrite ± erythrosiderite 3 Multiphase fluid inclusions with predominant homogenization temperatures 420 to 620˚C and predominant salinities 70 to 75 wt.%NaCl, are thought to be the early fluids involved in mineralization. 4 The coexistence of high saline liquid and vapor rich fluid inclusions (IIIAB, IIIB, IIIA and IIA types resulted either from fluid entrapment during the boiling process or the co-presence of two immiscible fluids generated from the magma. 5 Dalliporphyry Cu-Au deposit was formed in a magmatic-meteoric system. Discussion Two conventional thermometric procedures, freezing and heating, were employed for the measurement of temperature of homogenization and approximate salinity. Freezing was conducted mainly for halite-under saturated inclusions (types IIA and IIB, to measure the initial melting temperature (Te and the last melting point (Tmice, whereas heating was carried out on the halite-bearing inclusions (types IIIA, IIIB and IIIAB. Based on the microthermometric

  3. Double Pass 595?nm pulsed dye laser at a 6 minute interval for the treatment of port-wine stains is not more effective than single pass

    NARCIS (Netherlands)

    Peters, M. A. D.; van Drooge, A. M.; Wolkerstorfer, A.; van Gemert, M. J. C.; van der Veen, J. P. W.; Bos, J. D.; Beek, J. F.

    2012-01-01

    Background Pulsed dye laser (PDL) is the first choice for treatment of port wine stains (PWS). However, outcome is highly variable and only a few patients achieve complete clearance. The objective of the study was to compare efficacy and safety of single pass PDL with double pass PDL at a 6 minute

  4. 77 FR 31725 - Safety Zone; Belle Pass Dredge Operations, Belle Pass, Mile Marker 1.0 to Mile Marker (−0.2...

    Science.gov (United States)

    2012-05-30

    ... Environmental Health Risks and Safety Risks. This rule is not an economically significant rule and does not create an environmental risk to health or risk to safety that may disproportionately affect children. 11...-AA00 Safety Zone; Belle Pass Dredge Operations, Belle Pass, Mile Marker 1.0 to Mile Marker (-0.2), Port...

  5. Windshield washer fluid

    Science.gov (United States)

    ... tests Chest x-ray CT (computerized tomography, or advanced imaging) scan EKG (electrocardiogram, or heart tracing) Fluids ... Stanton BF, St. Geme JW, Schor NF, eds. Nelson Textbook of Pediatrics . 20th ed. Philadelphia, PA: Elsevier; ...

  6. COUPLED CHEMOTAXIS FLUID MODEL

    KAUST Repository

    LORZ, ALEXANDER

    2010-01-01

    We consider a model system for the collective behavior of oxygen-driven swimming bacteria in an aquatic fluid. In certain parameter regimes, such suspensions of bacteria feature large-scale convection patterns as a result of the hydrodynamic

  7. Phoresis in fluids.

    Science.gov (United States)

    Brenner, Howard

    2011-12-01

    This paper presents a unified theory of phoretic phenomena in single-component fluids. Simple formulas are given for the phoretic velocities of small inert force-free non-Brownian particles migrating through otherwise quiescent single-component gases and liquids and animated by a gradient in the fluid's temperature (thermophoresis), pressure (barophoresis), density (pycnophoresis), or any combination thereof. The ansatz builds upon a recent paper [Phys. Rev. E 84, 046309 (2011)] concerned with slip of the fluid's mass velocity at solid surfaces--that is, with phenomena arising from violations of the classical no-slip fluid-mechanical boundary condition. Experimental and other data are cited in support of the phoretic model developed herein.

  8. Peritoneal Fluid Analysis

    Science.gov (United States)

    ... Get Tested? To help diagnose the cause of peritonitis, an inflammation of the membrane lining the abdomen, ... fever and your healthcare practitioner suspects you have peritonitis or ascites Sample Required? A peritoneal fluid sample ...

  9. Fluid flow control system

    International Nuclear Information System (INIS)

    Rion, Jacky.

    1982-01-01

    Fluid flow control system featuring a series of grids placed perpendicular to the fluid flow direction, characterized by the fact that it is formed of a stack of identical and continuous grids, each of which consists of identical meshes forming a flat lattice. The said meshes are offset from one grid to the next. This system applies in particular to flow control of the coolant flowing at the foot of an assembly of a liquid metal cooled nuclear reactor [fr

  10. Amniotic fluid inflammatory cytokines

    DEFF Research Database (Denmark)

    Abdallah, Morsi; Larsen, Nanna; Grove, Jakob

    2013-01-01

    The aim of the study was to analyze cytokine profiles in amniotic fluid (AF) samples of children developing autism spectrum disorders (ASD) and controls, adjusting for maternal autoimmune disorders and maternal infections during pregnancy.......The aim of the study was to analyze cytokine profiles in amniotic fluid (AF) samples of children developing autism spectrum disorders (ASD) and controls, adjusting for maternal autoimmune disorders and maternal infections during pregnancy....

  11. [Diagnosis: synovial fluid analysis].

    Science.gov (United States)

    Gallo Vallejo, Francisco Javier; Giner Ruiz, Vicente

    2014-01-01

    Synovial fluid analysis in rheumatological diseases allows a more accurate diagnosis in some entities, mainly infectious and microcrystalline arthritis. Examination of synovial fluid in patients with osteoarthritis is useful if a differential diagnosis will be performed with other processes and to distinguish between inflammatory and non-inflammatory forms. Joint aspiration is a diagnostic and sometimes therapeutic procedure that is available to primary care physicians. Copyright © 2014 Elsevier España, S.L. All rights reserved.

  12. Immunotherapy With Magentorheologic Fluids

    Science.gov (United States)

    2011-08-01

    anti-tumor effects are weakened by removal of the tumor antigen pool (i.e. surgery) or use of cytoreductive and immunosuppressive therapies (i.e...particles were injected as magneto -rheological fluid (MRF) into an orthotopic primary breast cancer and followed by application of a magnetic field to...SUBJECT TERMS MRF: Magneto -rehological fluid iron particles, IT: immunotherapy, necrotic death, DCs: dendritic cells, cytokines, chemokines

  13. Supercritical fluid chromatography

    Science.gov (United States)

    Vigdergauz, M. S.; Lobachev, A. L.; Lobacheva, I. V.; Platonov, I. A.

    1992-03-01

    The characteristic features of supercritical fluid chromatography (SCFC) are examined and there is a brief historical note concerning the development of the method. Information concerning the use of supercritical fluid chromatography in the analysis of objects of different nature is presented in the form of a table. The roles of the mobile and stationary phases in the separation process and the characteristic features of the apparatus and of the use of the method in physicochemical research are discussed. The bibliography includes 364 references.

  14. Pass-through of exchange rates and tariffs in Greek-US tobacco trade

    OpenAIRE

    Rezitis, Anthony N.; Brown, A. Blake

    1999-01-01

    The paper examines the extent to which exchange rate and unit tariff changes are passed-through in US import prices of unmanufactured Greek oriental tobacco. The results indicate partial pass-through of exchange rates and tariffs. Exchange rate pass-through is about 0.272 and tariff pass-through about 0.185. One possible reason for the partial pass-through is oligopoly in tobacco exporting. Oligopoly would imply that depreciation of the drachma relative to the US dollar benefits tobacco expor...

  15. Passing the NBCOT Examination: Preadmission, Academic, and Fieldwork Factors

    Directory of Open Access Journals (Sweden)

    Sharon D. Novalis

    2017-10-01

    Full Text Available All occupational therapy students are required to successfully complete the certification examination administered by the National Board for Certification in Occupational Therapy (NBCOT before they can practice independently. The need to repeat the examination can result in stress, anxiety, and financial hardship. This paper explores the relationship of preadmission factors, academic and fieldwork performance, and demographic variables to successful first-time attempts on the certification examination for occupational therapists. Data were gathered from 144 student files in a Master of Occupational Therapy (MOT Program at a single university. Of the sample, 82% passed and 18% failed their first NBCOT test trial. Considered independently, preadmission recommendation letters and writing sample scores, graduate MOT program GPA, lack of MOT program difficulty, fieldwork self-reports, and gender predicted NBCOT certification examination outcomes. When considered together in logistic regression models predicting outcome, this combination of factors correctly predicted 86.2% of student outcomes (or 20% to 32% of the variance in certification examination success, with OT program GPA and preadmission recommendation scores predicting unique outcome variance. This information may be helpful to admissions committees as well as to occupational therapy faculty as they identify strategies and practices to facilitate first-time test taking success on the NBCOT certification examination

  16. Continuous Surface Rendering, Passing from CAD to Physical Representation

    Directory of Open Access Journals (Sweden)

    Mario Covarrubias

    2013-06-01

    Full Text Available This paper describes a desktop-mechatronic interface that has been conceived to support designers in the evaluation of aesthetic virtual shapes. This device allows a continuous and smooth free hand contact interaction on a real and developable plastic tape actuated by a servo-controlled mechanism. The objective in designing this device is to reproduce a virtual surface with a consistent physical rendering well adapted to designers' needs. The desktop-mechatronic interface consists in a servo-actuated plastic strip that has been devised and implemented using seven interpolation points. In fact, by using the MEC (Minimal Energy Curve Spline approach, a developable real surface is rendered taking into account the CAD geometry of the virtual shapes. In this paper, we describe the working principles of the interface by using both absolute and relative approaches to control the position on each single control point on the MEC spline. Then, we describe the methodology that has been implemented, passing from the CAD geometry, linked to VisualNastran in order to maintain the parametric properties of the virtual shape. Then, we present the co-simulation between VisualNastran and MATLAB/Simulink used for achieving this goal and controlling the system and finally, we present the results of the subsequent testing session specifically carried out to evaluate the accuracy and the effectiveness of the mechatronic device.

  17. Collective behavior of mice passing through an exit under panic

    Science.gov (United States)

    Zhang, Teng; Zhang, Xuelin; Huang, Shenshi; Li, Changhai; Lu, Shouxiang

    2018-04-01

    Collective movement of animal in emergency condition has attracted growing attentions among researchers. However, many rules still need to be confirmed with adequate explanation. Study of collective behavior of mice can improve our understanding about the dynamics of pedestrian movement. However, its rules still need to be confirmed with adequate explanation. In this paper, collective behavior of mice passing through an exit under panic was investigated. The results showed that the total evacuation time decreased with exit width increasing in a certain range. Based on the different tendency of the curve in temporal evolution, the process of mice flow was divided into three stages. The density of mice near the exit peaks at a certain horizontal offset and starts to decrease over time. With the increase of the exit width, the duration of the higher density state decreased. We found that the frequency of time intervals obeyed a lognormal distribution or an exponential decay for different exit widths. In addition, the relationship between the group size and the group flow rate in different scenarios was analyzed. The phenomena found in our experiments show the collective behavioral characteristic of mice under panic. Our analysis in this paper will deepen our understanding of crowd dynamics in emergency condition.

  18. Behaviour of neutrons passing through the Bloch wall

    International Nuclear Information System (INIS)

    Schaerpf, O.

    1976-01-01

    In part I of the present paper the pertinent knowledge about Bloch walls is presented and developed insofar as it appears necessary for the experiments with neutrons, that is to say the direction of magnetization within the domains, the calculation of the variation of magnetization in the wall, the wall thickness, and the zigzag structure of the Bloch wall. In part II it is first clarified why the Bloch wall can be treated as a continuum problem. It shows that this is possible far away from Laue reflexes. For angles far away from Laure-reflex angles the interaction of the periodic structure of the magnetization can be described with the aid of an averaged magnetic flux density. The consequence of it is the possibility of treating the problem by means of a Schroedinger equation with continous interaction. This leads to a law of refraction. The question of the possibilities for explaining the intensity behavior is treated in part III. This part, from different aspects, describes the fact, which already was pointed out in Schaerpf, O., Vehoff, H., Schwink, Ch. 1973, that the spin of the neutrons in passing through the wall is partly taken along by the magnetization gradually rotating in the wall. (orig./WBU) [de

  19. Chaos-pass filtering in injection-locked semiconductor lasers

    International Nuclear Information System (INIS)

    Murakami, Atsushi; Shore, K. Alan

    2005-01-01

    Chaos-pass filtering (CPF) of semiconductor lasers has been studied theoretically. CPF is a phenomenon which occurs in laser chaos synchronization by injection locking and is a fundamental technique for the extraction of messages at the receiver laser in chaotic communications systems. We employ a simple theory based on driven damped oscillators to clarify the physical background of CPF. The receiver laser is optically driven by injection from the transmitter laser. We have numerically investigated the response characteristics of the receiver when it is driven by periodic (message) and chaotic (carrier) signals. It is thereby revealed that the response of the receiver laser in the two cases is quite different. For the periodic drive, the receiver exhibits a response depending on the signal frequency, while the chaotic drive provides a frequency-independent synchronous response to the receiver laser. We verify that the periodic and chaotic drives occur independently in the CPF response, and, consequently, CPF can be clearly understood in the difference of the two drives. Message extraction using CPF is also examined, and the validity of our theoretical explanation for the physical mechanism underlying CPF is thus verified

  20. Milestone experiments for single pass UV/X-ray FELs

    Science.gov (United States)

    Ben-Zvi, Ilan

    1995-04-01

    In the past decade, significant advances have been made in the theory and technology of high brightness electron beams and single pass FELs. These developments facilitate the construction of practical UV and X-ray FELs and has prompted proposals to the DOE for the construction of such facilities. There are several important experiments to be performed before committing to the construction of dedicated user facilities. Two experiments are under construction in the IR, the UCLA self-amplified spontaneous emission experiment and the BNL laser seeded harmonic generation experiment. A multi-institution collaboration is being organized about a 210 MeV electron linac available at BNL and the 10 m long NISUS wiggler. This experiment will be done in the UV and will test various experimental aspects of electron beam dynamics, FEL exponential regime with gain guiding, start-up from noise, seeding and harmonic generation. These experiments will advance the state of FEL research and lead towards future dedicated users' facilities.