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Sample records for two-equation closure modelling

  1. A Note on Two-Equation Closure Modelling of Canopy Flow

    DEFF Research Database (Denmark)

    Sogachev, Andrey

    2009-01-01

    The note presents a rational approach to modelling the source/sink due to vegetation or buoyancy effects that appear in the turbulent kinetic energy, E, equation and a supplementary equation for a length-scale determining variable, φ, when two-equation closure is applied to canopy and atmospheric...

  2. Consistent Two-Equation Closure Modelling for Atmospheric Research: Buoyancy and Vegetation Implementations

    DEFF Research Database (Denmark)

    Sogachev, Andrey; Kelly, Mark C.; Leclerc, Monique Y.

    2012-01-01

    A self-consistent two-equation closure treating buoyancy and plant drag effects has been developed, through consideration of the behaviour of the supplementary equation for the length-scale-determining variable in homogeneous turbulent flow. Being consistent with the canonical flow regimes of gri...

  3. Non-Equilibrium Turbulence and Two-Equation Modeling

    Science.gov (United States)

    Rubinstein, Robert

    2011-01-01

    Two-equation turbulence models are analyzed from the perspective of spectral closure theories. Kolmogorov theory provides useful information for models, but it is limited to equilibrium conditions in which the energy spectrum has relaxed to a steady state consistent with the forcing at large scales; it does not describe transient evolution between such states. Transient evolution is necessarily through nonequilibrium states, which can only be found from a theory of turbulence evolution, such as one provided by a spectral closure. When the departure from equilibrium is small, perturbation theory can be used to approximate the evolution by a two-equation model. The perturbation theory also gives explicit conditions under which this model can be valid, and when it will fail. Implications of the non-equilibrium corrections for the classic Tennekes-Lumley balance in the dissipation rate equation are drawn: it is possible to establish both the cancellation of the leading order Re1/2 divergent contributions to vortex stretching and enstrophy destruction, and the existence of a nonzero difference which is finite in the limit of infinite Reynolds number.

  4. Two-equation turbulence modeling for 3-D hypersonic flows

    Science.gov (United States)

    Bardina, J. E.; Coakley, T. J.; Marvin, J. G.

    1992-01-01

    An investigation to verify, incorporate and develop two-equation turbulence models for three-dimensional high speed flows is presented. The current design effort of hypersonic vehicles has led to an intensive study of turbulence models for compressible hypersonic flows. This research complements an extensive review of experimental data and the current development of 2D turbulence models. The review of experimental data on 2D and 3D flows includes complex hypersonic flows with pressure profiles, skin friction, wall heat transfer, and turbulence statistics data. In a parallel effort, turbulence models for high speed flows have been tested against flat plate boundary layers, and are being tested against the 2D database. In the present paper, we present the results of 3D Navier-Stokes numerical simulations with an improved k-omega two-equation turbulence model against experimental data and empirical correlations of an adiabatic flat plate boundary layer, a cold wall flat plate boundary layer, and a 3D database flow, the interaction of an oblique shock wave and a thick turbulent boundary layer with a free stream Mach number = 8.18 and Reynolds number = 5 x 10 to the 6th.

  5. Multigrid solution of incompressible turbulent flows by using two-equation turbulence models

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, X.; Liu, C. [Front Range Scientific Computations, Inc., Denver, CO (United States); Sung, C.H. [David Taylor Model Basin, Bethesda, MD (United States)

    1996-12-31

    Most of practical flows are turbulent. From the interest of engineering applications, simulation of realistic flows is usually done through solution of Reynolds-averaged Navier-Stokes equations and turbulence model equations. It has been widely accepted that turbulence modeling plays a very important role in numerical simulation of practical flow problem, particularly when the accuracy is of great concern. Among the most used turbulence models today, two-equation models appear to be favored for the reason that they are more general than algebraic models and affordable with current available computer resources. However, investigators using two-equation models seem to have been more concerned with the solution of N-S equations. Less attention is paid to the solution method for the turbulence model equations. In most cases, the turbulence model equations are loosely coupled with N-S equations, multigrid acceleration is only applied to the solution of N-S equations due to perhaps the fact the turbulence model equations are source-term dominant and very stiff in sublayer region.

  6. Application of two-equation turbulence models to turbulent gas flow heated by a high heat flux

    International Nuclear Information System (INIS)

    Kawamura, Hiroshi

    1978-01-01

    Heat transfer in heated turbulent gas flow is analyzed using two-equation turbulence models. Four kinds of two-equation models are examined; that is, k-epsilon model by Jones-Launder, k-w model by Wilcox-Traci, k-kL model by Rotta, k-ω model by Saffman-Wilcox. The results are compared with more than ten experiments by seven authors. The k-kL model proposed originally by Rotta and modified by the present author is found to give relatively the best results. It well predicts the decrease in the heat transfer coefficient found in the heated turbulent gas flow; however, it fails to predict the laminarization due to a strong heating. (author)

  7. Two-equation and multi-fluid turbulence models for Rayleigh–Taylor mixing

    International Nuclear Information System (INIS)

    Kokkinakis, I.W.; Drikakis, D.; Youngs, D.L.; Williams, R.J.R.

    2015-01-01

    Highlights: • We present a new improved version of the K–L model. • The improved K–L is found in good agreement with the multi-fluid model and ILES. • The study concerns Rayleigh–Taylor flows at initial density ratios 3:1 and 20:1. - Abstract: This paper presents a new, improved version of the K–L model, as well as a detailed investigation of K–L and multi-fluid models with reference to high-resolution implicit large eddy simulations of compressible Rayleigh–Taylor mixing. The accuracy of the models is examined for different interface pressures and specific heat ratios for Rayleigh–Taylor flows at initial density ratios 3:1 and 20:1. It is shown that the original version of the K–L model requires modifications in order to provide comparable results to the multi-fluid model. The modifications concern the addition of an enthalpy diffusion term to the energy equation; the formulation of the turbulent kinetic energy (source) term in the K equation; and the calculation of the local Atwood number. The proposed modifications significantly improve the results of the K–L model, which are found in good agreement with the multi-fluid model and implicit large eddy simulations with respect to the self-similar mixing width; peak turbulent kinetic energy growth rate, as well as volume fraction and turbulent kinetic energy profiles. However, a key advantage of the two-fluid model is that it can represent the degree of molecular mixing in a direct way, by transferring mass between the two phases. The limitations of the single-fluid K–L model as well as the merits of more advanced Reynolds-averaged Navier–Stokes models are also discussed throughout the paper.

  8. Correspondence Between One- and Two-Equation Models for Solute Transport in Two-Region Heterogeneous Porous Media

    KAUST Repository

    Davit, Y.

    2012-07-26

    In this work, we study the transient behavior of homogenized models for solute transport in two-region porous media. We focus on the following three models: (1) a time non-local, two-equation model (2eq-nlt). This model does not rely on time constraints and, therefore, is particularly useful in the short-time regime, when the timescale of interest (t) is smaller than the characteristic time (τ 1) for the relaxation of the effective macroscale parameters (i. e., when t ≤ τ 1); (2) a time local, two-equation model (2eq). This model can be adopted when (t) is significantly larger than (τ 1) (i.e., when t≫τ 1); and (3) a one-equation, time-asymptotic formulation (1eq ∞). This model can be adopted when (t) is significantly larger than the timescale (τ 2) associated with exchange processes between the two regions (i. e., when t≫τ 2). In order to obtain insight into this transient behavior, we combine a theoretical approach based on the analysis of spatial moments with numerical and analytical results in several simple cases. The main result of this paper is to show that there is only a weak asymptotic convergence of the solution of (2eq) towards the solution of (1eq ∞) in terms of standardized moments but, interestingly, not in terms of centered moments. The physical interpretation of this result is that deviations from the Fickian situation persist in the limit of long times but that the spreading of the solute is eventually dominating these higher order effects. © 2012 Springer Science+Business Media B.V.

  9. Turbulence modeling for mass transfer enhancement by separation and reattachment with two-equation eddy-viscosity models

    International Nuclear Information System (INIS)

    Xiong Jinbiao; Koshizuka, Seiichi; Sakai, Mikio

    2011-01-01

    Highlights: → We selected and evaluated five two-equation eddy-viscosity turbulence models for modeling the separated and reattaching flow. → The behavior of the models in the simple flow is not consistent with that in the separated and reattaching flow. → The Abe-Kondoh-Nagano model is the best one among the selected model. → Application of the stress limiter and the Kato-Launder modification in the Abe-Kondoh-Nagano model helps to improve prediction of the peak mass transfer coefficient in the orifice flow. → The value of turbulent Schmidt number is investigated. - Abstract: The prediction of mass transfer rate is one of the key elements for estimation of the flow accelerated corrosion (FAC) rate. Three low Reynolds number (LRN) k-ε models (Lam-Bremhorst (LB), Abe-Kondoh-Nagano (AKN) and Hwang-Lin (HL)), one LRN k-ω (Wilcox, WX) model and the k-ω SST model are tested for the computation of the high Schmidt number mass transfer, especially in the flow through an orifice. The models are tested in the computation of three types of flow: (1) the fully developed pipe flow, (2) the flow over a backward facing step, (3) the flow through an orifice. The HL model shows a good performance in predicting mass transfer in the fully developed pipe flow but fails to give reliable prediction in the flow through an orifice. The WX model and the k-ω SST model underpredict the mass transfer rate in the flow types 1 and 3. The LB model underestimates the mass transfer in the flow type 1, but shows abnormal behavior at the reattaching point in type 3. Synthetically evaluating all the models in all the computed case, the AKN model is the best one; however, the prediction is still not satisfactory. In the evaluation in the flow over a backward facing step shows k-ω SST model shows superior performance. This is interpreted as an implication that the combination of the k-ε model and the stress limiter can improve the model behavior in the recirculation bubble. Both the

  10. Moment Closure for the Stochastic Logistic Model

    National Research Council Canada - National Science Library

    Singh, Abhyudai; Hespanha, Joao P

    2006-01-01

    ..., which we refer to as the moment closure function. In this paper, a systematic procedure for constructing moment closure functions of arbitrary order is presented for the stochastic logistic model...

  11. One-dimensional wave bottom boundary layer model comparison: specific eddy viscosity and turbulence closure models

    Science.gov (United States)

    Puleo, J.A.; Mouraenko, O.; Hanes, D.M.

    2004-01-01

    Six one-dimensional-vertical wave bottom boundary layer models are analyzed based on different methods for estimating the turbulent eddy viscosity: Laminar, linear, parabolic, k—one equation turbulence closure, k−ε—two equation turbulence closure, and k−ω—two equation turbulence closure. Resultant velocity profiles, bed shear stresses, and turbulent kinetic energy are compared to laboratory data of oscillatory flow over smooth and rough beds. Bed shear stress estimates for the smooth bed case were most closely predicted by the k−ω model. Normalized errors between model predictions and measurements of velocity profiles over the entire computational domain collected at 15° intervals for one-half a wave cycle show that overall the linear model was most accurate. The least accurate were the laminar and k−ε models. Normalized errors between model predictions and turbulence kinetic energy profiles showed that the k−ω model was most accurate. Based on these findings, when the smallest overall velocity profile prediction error is required, the processing requirements and error analysis suggest that the linear eddy viscosity model is adequate. However, if accurate estimates of bed shear stress and TKE are required then, of the models tested, the k−ω model should be used.

  12. Hamiltonian closures in fluid models for plasmas

    Science.gov (United States)

    Tassi, Emanuele

    2017-11-01

    This article reviews recent activity on the Hamiltonian formulation of fluid models for plasmas in the non-dissipative limit, with emphasis on the relations between the fluid closures adopted for the different models and the Hamiltonian structures. The review focuses on results obtained during the last decade, but a few classical results are also described, in order to illustrate connections with the most recent developments. With the hope of making the review accessible not only to specialists in the field, an introduction to the mathematical tools applied in the Hamiltonian formalism for continuum models is provided. Subsequently, we review the Hamiltonian formulation of models based on the magnetohydrodynamics description, including those based on the adiabatic and double adiabatic closure. It is shown how Dirac's theory of constrained Hamiltonian systems can be applied to impose the incompressibility closure on a magnetohydrodynamic model and how an extended version of barotropic magnetohydrodynamics, accounting for two-fluid effects, is amenable to a Hamiltonian formulation. Hamiltonian reduced fluid models, valid in the presence of a strong magnetic field, are also reviewed. In particular, reduced magnetohydrodynamics and models assuming cold ions and different closures for the electron fluid are discussed. Hamiltonian models relaxing the cold-ion assumption are then introduced. These include models where finite Larmor radius effects are added by means of the gyromap technique, and gyrofluid models. Numerical simulations of Hamiltonian reduced fluid models investigating the phenomenon of magnetic reconnection are illustrated. The last part of the review concerns recent results based on the derivation of closures preserving a Hamiltonian structure, based on the Hamiltonian structure of parent kinetic models. Identification of such closures for fluid models derived from kinetic systems based on the Vlasov and drift-kinetic equations are presented, and

  13. Comparison of two equation-of-state models for partially ionized aluminum: Zel'dovich and Raizer's model versus the activity expansion code

    Energy Technology Data Exchange (ETDEWEB)

    Harrach, R.J.; Rogers, F.J.

    1981-09-01

    Two equation-of-state (EOS) models for multipy ionized matter are evaluated for the case of an aluminum plasma in the temperature range from about one eV to several hundred eV, spanning conditions of weak to strong ionization. Specifically, the simple analytical mode of Zel'dovich and Raizer and the more comprehensive model comprised by Rogers' plasma physics avtivity expansion code (ACTEX) are used to calculate the specific internal energy epsilon and average degree of ionization Z-bar*, as functons of temperature T and density rho. In the absence of experimental data, these results are compared against each other, covering almost five orders-of-magnitude variation in epsilon and the full range of Z-bar* We find generally good agreement between the two sets of results, especially for low densities and for temperatures near the upper end of the rage. Calculated values of epsilon(T) agree to within +- 30% over nearly the full range in T for densities below about 1 g/cm/sup 3/. Similarly, the two models predict values of Z-bar*(T) which track each other fairly well; above 20 eV the discrepancy is less than +- 20% fpr rho< or approx. =1 g/cm/sup 3/. Where the calculations disagree, we expect the ACTEX code to be more accurate than Zel'dovich and Raizer's model, by virtue of its more detailed physics content.

  14. Comparison of two equation-of-state models for partially ionized aluminum: Zel'dovich and Raizer's model versus the activity expansion code

    Science.gov (United States)

    Harrach, Robert J.; Rogers, Forest J.

    1981-09-01

    Two equation-of-state (EOS) models for multipy ionized matter are evaluated for the case of an aluminum plasma in the temperature range from about one eV to several hundred eV, spanning conditions of weak to strong ionization. Specifically, the simple analytical mode of Zel'dovich and Raizer and the more comprehensive model comprised by Rogers' plasma physics avtivity expansion code (ACTEX) are used to calculate the specific internal energy ɛ and average degree of ionization Z¯*, as functons of temperature T and density ρ. In the absence of experimental data, these results are compared against each other, covering almost five orders-of-magnitude variation in ɛ and the full range of Z¯* We find generally good agreement between the two sets of results, especially for low densities and for temperatures near the upper end of the rage. Calculated values of ɛ(T) agree to within ±30% over nearly the full range in T for densities below about 1 g/cm3. Similarly, the two models predict values of Z¯*(T) which track each other fairly well; above 20 eV the discrepancy is less than ±20% fpr ρ≲1 g/cm3. Where the calculations disagree, we expect the ACTEX code to be more accurate than Zel'dovich and Raizer's model, by virtue of its more detailed physics content.

  15. Improving a two-equation eddy-viscosity turbulence model to predict the aerodynamic performance of thick wind turbine airfoils

    Science.gov (United States)

    Bangga, Galih; Kusumadewi, Tri; Hutomo, Go; Sabila, Ahmad; Syawitri, Taurista; Setiadi, Herlambang; Faisal, Muhamad; Wiranegara, Raditya; Hendranata, Yongki; Lastomo, Dwi; Putra, Louis; Kristiadi, Stefanus

    2018-03-01

    Numerical simulations for relatively thick airfoils are carried out in the present studies. An attempt to improve the accuracy of the numerical predictions is done by adjusting the turbulent viscosity of the eddy-viscosity Menter Shear-Stress-Transport (SST) model. The modification involves the addition of a damping factor on the wall-bounded flows incorporating the ratio of the turbulent kinetic energy to its specific dissipation rate for separation detection. The results are compared with available experimental data and CFD simulations using the original Menter SST model. The present model improves the lift polar prediction even though the stall angle is still overestimated. The improvement is caused by the better prediction of separated flow under a strong adverse pressure gradient. The results show that the Reynolds stresses are damped near the wall causing variation of the logarithmic velocity profiles.

  16. Eigenspace perturbations for structural uncertainty estimation of turbulence closure models

    Science.gov (United States)

    Jofre, Lluis; Mishra, Aashwin; Iaccarino, Gianluca

    2017-11-01

    With the present state of computational resources, a purely numerical resolution of turbulent flows encountered in engineering applications is not viable. Consequently, investigations into turbulence rely on various degrees of modeling. Archetypal amongst these variable resolution approaches would be RANS models in two-equation closures, and subgrid-scale models in LES. However, owing to the simplifications introduced during model formulation, the fidelity of all such models is limited, and therefore the explicit quantification of the predictive uncertainty is essential. In such scenario, the ideal uncertainty estimation procedure must be agnostic to modeling resolution, methodology, and the nature or level of the model filter. The procedure should be able to give reliable prediction intervals for different Quantities of Interest, over varied flows and flow conditions, and at diametric levels of modeling resolution. In this talk, we present and substantiate the Eigenspace perturbation framework as an uncertainty estimation paradigm that meets these criteria. Commencing from a broad overview, we outline the details of this framework at different modeling resolution. Thence, using benchmark flows, along with engineering problems, the efficacy of this procedure is established. This research was partially supported by NNSA under the Predictive Science Academic Alliance Program (PSAAP) II, and by DARPA under the Enabling Quantification of Uncertainty in Physical Systems (EQUiPS) project (technical monitor: Dr Fariba Fahroo).

  17. A systematic comparison of two-equation Reynolds-averaged Navier-Stokes turbulence models applied to shock-cloud interactions

    Science.gov (United States)

    Goodson, Matthew D.; Heitsch, Fabian; Eklund, Karl; Williams, Virginia A.

    2017-07-01

    Turbulence models attempt to account for unresolved dynamics and diffusion in hydrodynamical simulations. We develop a common framework for two-equation Reynolds-averaged Navier-Stokes turbulence models, and we implement six models in the athena code. We verify each implementation with the standard subsonic mixing layer, although the level of agreement depends on the definition of the mixing layer width. We then test the validity of each model into the supersonic regime, showing that compressibility corrections can improve agreement with experiment. For models with buoyancy effects, we also verify our implementation via the growth of the Rayleigh-Taylor instability in a stratified medium. The models are then applied to the ubiquitous astrophysical shock-cloud interaction in three dimensions. We focus on the mixing of shock and cloud material, comparing results from turbulence models to high-resolution simulations (up to 200 cells per cloud radius) and ensemble-averaged simulations. We find that the turbulence models lead to increased spreading and mixing of the cloud, although no two models predict the same result. Increased mixing is also observed in inviscid simulations at resolutions greater than 100 cells per radius, which suggests that the turbulent mixing begins to be resolved.

  18. Three-Dimensional Navier-Stokes Simulations with Two-Equation Turbulence Models of Intersecting Shock-Waves/Turbulent Boundary Layer at Mach 8.3

    Science.gov (United States)

    Bardina, J. E.; Coakley, T. J.

    1994-01-01

    An investigation of the numerical simulation with two-equation turbulence models of a three-dimensional hypersonic intersecting (SWTBL) shock-wave/turbulent boundary layer interaction flow is presented. The flows are solved with an efficient implicit upwind flux-difference split Reynolds-averaged Navier-Stokes code. Numerical results are compared with experimental data for a flow at Mach 8.28 and Reynolds number 5.3x10(exp 6) with crossing shock-waves and expansion fans generated by two lateral 15 fins located on top of a cold-wall plate. This experiment belongs to the hypersonic database for modeling validation. Simulations show the development of two primary counter-rotating cross-flow vortices and secondary turbulent structures under the main vortices and in each corner singularity inside the turbulent boundary layer. A significant loss of total pressure is produced by the complex interaction between the main vortices and the uplifted jet stream of the boundary layer. The overall agreement between computational and experimental data is generally good. The turbulence modeling corrections show improvements in the predictions of surface heat transfer distribution and an increase in the strength of the cross-flow vortices. Accurate predictions of the outflow flowfield is found to require accurate modeling of the laminar/turbulent boundary layers on the fin walls.

  19. Nonperturbative quantization ‘a la Heisenberg for non-Abelian gauge theories: two-equation approximation. Applications: a flux tube solution and a scalar model of glueball

    Directory of Open Access Journals (Sweden)

    Dzhunushaliev Vladimir

    2017-01-01

    Full Text Available The nonperturbative quantization technique à la Heisenberg is applied for the SU(3 gauge theory. The operator Yang-Mills equation and corresponding infinite set of equations for all Green’s functions are considered. Gauge degrees of freedom are splitted into two groups: (1 Aμa ∈ SU (2 × U(1 ⊂ SU(3; (2 coset degrees of freedom SU(3/SU(2 × U(1. Using some assumptions about 2- and 4-point Green’s functions, the infinite set of equations is truncated to two equations. The first equation is the SU(2 × U(1 Yang-Mills equation, and the second equation describes a gluon condensate formed by coset fields. A flux tube solution describing longitudinal color electric fields stretched between quark and antiquark located at the ± infinities is obtained. It is shown that the dual Meissner effect appears in this solution: the electric field is pushed out from the gluon condensate.

  20. Modeling closure of circular wounds through coordinated collective motion

    Science.gov (United States)

    Li, David S.; Zimmermann, Juliane; Levine, Herbert

    2016-02-01

    Wound healing enables tissues to restore their original states, and is achieved through collective cell migration into the wound space, contraction of the wound edge via an actomyosin filament ‘purse-string,’ as well as cell division. Recently, experimental techniques have been developed to create wounds with various regular morphologies in epithelial monolayers, and these experiments of circular closed-contour wounds support coordinated lamellipodial cell crawling as the predominant driver of gap closure. Through utilizing a particle-based mechanical tissue simulation, exhibiting long-range coordination of cell motility, we computationally model these closed-contour experiments with a high level of agreement between experimentally observed and simulated wound closure dynamics and tissue velocity profiles. We also determine the sensitivity of wound closure time in the model to changes in cell motility force and division rate. Our simulation results confirm that circular wounds can close due to collective cell migration without the necessity for a purse-string mechanism or for cell division, and show that the alignment mechanism of cellular motility force with velocity, leading to collective motion in the model, may speed up wound closure.

  1. Superresolving Black Hole Images with Full-Closure Sparse Modeling

    Science.gov (United States)

    Crowley, Chelsea; Akiyama, Kazunori; Fish, Vincent

    2018-01-01

    It is believed that almost all galaxies have black holes at their centers. Imaging a black hole is a primary objective to answer scientific questions relating to relativistic accretion and jet formation. The Event Horizon Telescope (EHT) is set to capture images of two nearby black holes, Sagittarius A* at the center of the Milky Way galaxy roughly 26,000 light years away and the other M87 which is in Virgo A, a large elliptical galaxy that is 50 million light years away. Sparse imaging techniques have shown great promise for reconstructing high-fidelity superresolved images of black holes from simulated data. Previous work has included the effects of atmospheric phase errors and thermal noise, but not systematic amplitude errors that arise due to miscalibration. We explore a full-closure imaging technique with sparse modeling that uses closure amplitudes and closure phases to improve the imaging process. This new technique can successfully handle data with systematic amplitude errors. Applying our technique to synthetic EHT data of M87, we find that full-closure sparse modeling can reconstruct images better than traditional methods and recover key structural information on the source, such as the shape and size of the predicted photon ring. These results suggest that our new approach will provide superior imaging performance for data from the EHT and other interferometric arrays.

  2. Multivariate moment closure techniques for stochastic kinetic models

    Energy Technology Data Exchange (ETDEWEB)

    Lakatos, Eszter, E-mail: e.lakatos13@imperial.ac.uk; Ale, Angelique; Kirk, Paul D. W.; Stumpf, Michael P. H., E-mail: m.stumpf@imperial.ac.uk [Department of Life Sciences, Centre for Integrative Systems Biology and Bioinformatics, Imperial College London, London SW7 2AZ (United Kingdom)

    2015-09-07

    Stochastic effects dominate many chemical and biochemical processes. Their analysis, however, can be computationally prohibitively expensive and a range of approximation schemes have been proposed to lighten the computational burden. These, notably the increasingly popular linear noise approximation and the more general moment expansion methods, perform well for many dynamical regimes, especially linear systems. At higher levels of nonlinearity, it comes to an interplay between the nonlinearities and the stochastic dynamics, which is much harder to capture correctly by such approximations to the true stochastic processes. Moment-closure approaches promise to address this problem by capturing higher-order terms of the temporally evolving probability distribution. Here, we develop a set of multivariate moment-closures that allows us to describe the stochastic dynamics of nonlinear systems. Multivariate closure captures the way that correlations between different molecular species, induced by the reaction dynamics, interact with stochastic effects. We use multivariate Gaussian, gamma, and lognormal closure and illustrate their use in the context of two models that have proved challenging to the previous attempts at approximating stochastic dynamics: oscillations in p53 and Hes1. In addition, we consider a larger system, Erk-mediated mitogen-activated protein kinases signalling, where conventional stochastic simulation approaches incur unacceptably high computational costs.

  3. Data-driven non-Markovian closure models

    Science.gov (United States)

    Kondrashov, Dmitri; Chekroun, Mickaël D.; Ghil, Michael

    2015-03-01

    This paper has two interrelated foci: (i) obtaining stable and efficient data-driven closure models by using a multivariate time series of partial observations from a large-dimensional system; and (ii) comparing these closure models with the optimal closures predicted by the Mori-Zwanzig (MZ) formalism of statistical physics. Multilayer stochastic models (MSMs) are introduced as both a generalization and a time-continuous limit of existing multilevel, regression-based approaches to closure in a data-driven setting; these approaches include empirical model reduction (EMR), as well as more recent multi-layer modeling. It is shown that the multilayer structure of MSMs can provide a natural Markov approximation to the generalized Langevin equation (GLE) of the MZ formalism. A simple correlation-based stopping criterion for an EMR-MSM model is derived to assess how well it approximates the GLE solution. Sufficient conditions are derived on the structure of the nonlinear cross-interactions between the constitutive layers of a given MSM to guarantee the existence of a global random attractor. This existence ensures that no blow-up can occur for a broad class of MSM applications, a class that includes non-polynomial predictors and nonlinearities that do not necessarily preserve quadratic energy invariants. The EMR-MSM methodology is first applied to a conceptual, nonlinear, stochastic climate model of coupled slow and fast variables, in which only slow variables are observed. It is shown that the resulting closure model with energy-conserving nonlinearities efficiently captures the main statistical features of the slow variables, even when there is no formal scale separation and the fast variables are quite energetic. Second, an MSM is shown to successfully reproduce the statistics of a partially observed, generalized Lotka-Volterra model of population dynamics in its chaotic regime. The challenges here include the rarity of strange attractors in the model's parameter

  4. Work zone lane closure analysis model.

    Science.gov (United States)

    2009-10-01

    At the Alabama Department of Transportation (ALDOT), the tool used by traffic engineers to predict whether a queue will form at a freeway work zone is the Excel-based "Lane Rental Model" developed at the Oklahoma Department of Transportation (OkDOT) ...

  5. Modeling Effects of Groundwater Basin Closure, and Reversal of Closure, on Groundwater Quality

    Science.gov (United States)

    Pauloo, R.; Guo, Z.; Fogg, G. E.

    2017-12-01

    Population growth, the expansion of agriculture, and climate uncertainties have accelerated groundwater pumping and overdraft in aquifers worldwide. In many agricultural basins, a water budget may be stable or not in overdraft, yet disconnected ground and surface water bodies can contribute to the formation of a "closed" basin, where water principally exits the basin as evapotranspiration. Although decreasing water quality associated with increases in Total Dissolved Solids (TDS) have been documented in aquifers across the United States in the past half century, connections between water quality declines and significant changes in hydrologic budgets leading to closed basin formation remain poorly understood. Preliminary results from an analysis with a regional-scale mixing model of the Tulare Lake Basin in California indicate that groundwater salinization resulting from open to closed basin conversion can operate on a decades-to-century long time scale. The only way to reverse groundwater salinization caused by basin closure is to refill the basin and change the hydrologic budget sufficiently for natural groundwater discharge to resume. 3D flow and transport modeling, including the effects of heterogeneity based on a hydrostratigraphic facies model, is used to explore rates and time scales of groundwater salinization and its reversal under different water and land management scenarios. The modeling is also used to ascertain the extent to which local and regional heterogeneity need to be included in order to appropriately upscale the advection-dispersion equation in a basin scale groundwater quality management model. Results imply that persistent managed aquifer recharge may slow groundwater salinization, and complete reversal may be possible at sufficiently high water tables.

  6. Assessment of closure coefficients for compressible-flow turbulence models

    Science.gov (United States)

    Huang, P. G.; Bradshaw, P.; Coakley, T. J.

    1992-01-01

    A critical assessment is made of the closure coefficients used for turbulence length scale in existing models of the transport equation, with reference to the extension of these models to compressible flow. It is shown that to satisfy the compressible 'law of the wall', the model coefficients must actually be functions of density gradients. The magnitude of the errors that result from neglecting this dependence on density varies with the variable used to specify the length scale. Among the models investigated, the k-omega model yields the best performance, although it is not completely free from errors associated with density terms. Models designed to reduce the density-gradient effect to an insignificant level are proposed.

  7. Modeling elephant-mediated cascading effects of water point closure.

    Science.gov (United States)

    Hilbers, Jelle P; Van Langevelde, Frank; Prins, Herbert H T; Grant, C C; Peel, Mike J S; Coughenour, Michael B; De Knegt, Henrik J; Slotow, Rob; Smit, Izak P J; Kiker, Greg A; De Boer, Willem F

    2015-03-01

    Wildlife management to reduce the impact of wildlife on their habitat can be done in several ways, among which removing animals (by either culling or translocation) is most often used. There are, however, alternative ways to control wildlife densities, such as opening or closing water points. The effects of these alternatives are poorly studied. In this paper, we focus on manipulating large herbivores through the closure of water points (WPs). Removal of artificial WPs has been suggested in order to change the distribution of African elephants, which occur in high densities in national parks in Southern Africa and are thought to have a destructive effect on the vegetation. Here, we modeled the long-term effects of different scenarios of WP closure on the spatial distribution of elephants, and consequential effects on the vegetation and other herbivores in Kruger National Park, South Africa. Using a dynamic ecosystem model, SAVANNA, scenarios were evaluated that varied in availability of artificial WPs; levels of natural water; and elephant densities. Our modeling results showed that elephants can indirectly negatively affect the distributions of meso-mixed feeders, meso-browsers, and some meso-grazers under wet conditions. The closure of artificial WPs hardly had any effect during these natural wet conditions. Under dry conditions, the spatial distribution of both elephant bulls and cows changed when the availability of artificial water was severely reduced in the model. These changes in spatial distribution triggered changes in the spatial availability of woody biomass over the simulation period of 80 years, and this led to changes in the rest of the herbivore community, resulting in increased densities of all herbivores, except for giraffe and steenbok, in areas close to rivers. The spatial distributions of elephant bulls and cows showed to be less affected by the closure of WPs than most of the other herbivore species. Our study contributes to ecologically

  8. 488-4D ASH LANDFILL CLOSURE CAP HELP MODELING

    Energy Technology Data Exchange (ETDEWEB)

    Phifer, M.

    2014-11-17

    At the request of Area Completion Projects (ACP) in support of the 488-4D Landfill closure, the Savannah River National Laboratory (SRNL) has performed Hydrologic Evaluation of Landfill Performance (HELP) modeling of the planned 488-4D Ash Landfill closure cap to ensure that the South Carolina Department of Health and Environmental Control (SCDHEC) limit of no more than 12 inches of head on top of the barrier layer (saturated hydraulic conductivity of no more than 1.0E-05 cm/s) in association with a 25-year, 24-hour storm event is not projected to be exceeded. Based upon Weber 1998 a 25-year, 24-hour storm event at the Savannah River Site (SRS) is 6.1 inches. The results of the HELP modeling indicate that the greatest peak daily head on top of the barrier layer (i.e. geosynthetic clay liner (GCL) or high density polyethylene (HDPE) geomembrane) for any of the runs made was 0.079 inches associated with a peak daily precipitation of 6.16 inches. This is well below the SCDHEC limit of 12 inches.

  9. Models for the closure of a coastal latent heat polynya

    Science.gov (United States)

    Biggs, N.; Willmott, A.; Austin, L.

    2003-04-01

    "Polynya flux models" approximate the evolution of a coastal latent heat polynya by assuming that the position of the polynya edge (P) is determined by a balance between the flux of frazil ice arriving at P and the flux of consolidated new ice removed at P by the offshore ice sheet. If the fluxes are equal, then the polynya is in equilibrium; if they are not, then the polynya is in a state of evolution. Flux models have mostly been used to investigate polynya opening events. In this talk however, we first summarise our findings concerning the closure due to an onshore wind stress of a coastal polynya which lies adjacent to an infinite straight coastline, and thus is effectively one-dimensional. In particular, we note that for one-dimensional polynyas, opening times typically exceed closing times. This asymmetry occurs since the two processes governing polynya evolution, frazil ice pile-up at the "convergence boundary" (i.e. the consolidated ice during opening or the stationary coastal wall during closing) and transport of consolidated new ice from the polynya, are in competition during opening, but complement one another during closing. We then address the closure of a fully two-dimensional coastal polynya lying adjacent to a straight coastline of finite extent, and identify parameter regimes for which the one-dimensional asymmetry in opening and closing times carries over to the two-dimensional case.

  10. Paradigm for Subgrid Scale Closure Modeling in Multiphase Geophysical Flows

    Science.gov (United States)

    Calantoni, J.; Simeonov, J.; Penko, A. M.; Bateman, S. P.; Palmsten, M. L.; Holland, K.

    2012-12-01

    We present a new paradigm for modeling multiphase geophysical flows to produce highly accurate and highly efficient forecasting of the complexity of the natural environment across the full range of relevant length and time scales. The assumption that computing technology will never allow us to perform direct numerical simulations (DNS) of the natural environment often limits our ambition in forward thinking model development and produces only incremental improvements in the state-of-the-art technology. Regional and global forecasting models for earth, ocean, and atmospheric processes based on averaged equations (e.g. RANS) must advance beyond simple closures relations obtained for single-phase fluid turbulence (e.g., k-epsilon, k-omega, and Mellor-Yamada). We propose using a hierarchy of computationally intensive, high fidelity simulations to resolve subgrid processes across a range of cascading length and time scales in the model domain to generate numerical interpolations for the unresolved physical processes. Further, we believe that it is possible to use the cumulative results of these subgrid scale simulations to develop a Bayesian network, for example, which may eventually replace the computationally intensive simulations with a highly efficient probabilistic closure model for the unresolved physical processes. The success of our approach will be greatly enhanced through rigorous validation of our subgrid scale models using three-dimensional laboratory and field measurements of fluid-particle turbulence at the scales of interest. Recent advances in optical imaging techniques have made it possible to make highly resolved three-dimensional measurements of fluid-particle turbulent interactions in the laboratory with spatial and temporal resolutions at or near the Kolmogorov scales. Additional work must be done to transition these technologies for use in the field. As a pilot test case we introduce our new paradigm using a hierarchy of models we have developed

  11. Development of a risk-based mine closure cost calculation model

    CSIR Research Space (South Africa)

    Du

    2006-06-01

    Full Text Available The study summarised in this paper focused on expanding existing South African mine closure cost calculation models to provide a new model that incorporates risks, which could have an effect on the closure costs during the life cycle of the mine...

  12. Volume Averaging Theory (VAT) based modeling and closure evaluation for fin-and-tube heat exchangers

    Science.gov (United States)

    Zhou, Feng; Catton, Ivan

    2012-10-01

    A fin-and-tube heat exchanger was modeled based on Volume Averaging Theory (VAT) in such a way that the details of the original structure was replaced by their averaged counterparts, so that the VAT based governing equations can be efficiently solved for a wide range of parameters. To complete the VAT based model, proper closure is needed, which is related to a local friction factor and a heat transfer coefficient of a Representative Elementary Volume (REV). The terms in the closure expressions are complex and sometimes relating experimental data to the closure terms is difficult. In this work we use CFD to evaluate the rigorously derived closure terms over one of the selected REVs. The objective is to show how heat exchangers can be modeled as a porous media and how CFD can be used in place of a detailed, often formidable, experimental effort to obtain closure for the model.

  13. An Analytical Model for Fatigue Life Prediction Based on Fracture Mechanics and Crack Closure

    DEFF Research Database (Denmark)

    Ibsø, Jan Behrend; Agerskov, Henning

    1996-01-01

    test specimens are compared with fatigue life predictions using a fracture mechanics approach. In the calculation of the fatigue life, the influence of the welding residual stresses and crack closure on the fatigue crack growth is considered. A description of the crack closure model for analytical...

  14. Modeling and Simulating Passenger Behavior for a Station Closure in a Rail Transit Network

    Science.gov (United States)

    Yin, Haodong; Han, Baoming; Li, Dewei; Wu, Jianjun; Sun, Huijun

    2016-01-01

    A station closure is an abnormal operational situation in which the entrances or exits of a rail transit station have to be closed for some time due to an unexpected incident. A novel approach is developed to estimate the impacts of the alternative station closure scenarios on both passenger behavioral choices at the individual level and passenger demand at the disaggregate level in a rail transit network. Therefore, the contributions of this study are two-fold: (1) A basic passenger behavior optimization model is mathematically constructed based on 0–1 integer programming to describe passengers’ responses to alternative origin station closure scenarios and destination station closure scenarios; this model also considers the availability of multi-mode transportation and the uncertain duration of the station closure; (2) An integrated solution algorithm based on the passenger simulation is developed to solve the proposed model and to estimate the effects of a station closure on passenger demand in a rail transit network. Furthermore, 13 groups of numerical experiments based on the Beijing rail transit network are performed as case studies with 2,074,267 records of smart card data. The comparisons of the model outputs and the manual survey show that the accuracy of our proposed behavior optimization model is approximately 80%. The results also show that our model can be used to capture the passenger behavior and to quantitatively estimate the effects of alternative closure scenarios on passenger flow demand for the rail transit network. Moreover, the closure duration and its overestimation greatly influence the individual behavioral choices of the affected passengers and the passenger demand. Furthermore, if the rail transit operator can more accurately estimate the closure duration (namely, as g approaches 1), the impact of the closure can be somewhat mitigated. PMID:27935963

  15. Model-Based Comprehensive Analysis of School Closure Policies for Mitigating Influenza Epidemics and Pandemics.

    Science.gov (United States)

    Fumanelli, Laura; Ajelli, Marco; Merler, Stefano; Ferguson, Neil M; Cauchemez, Simon

    2016-01-01

    School closure policies are among the non-pharmaceutical measures taken into consideration to mitigate influenza epidemics and pandemics spread. However, a systematic review of the effectiveness of alternative closure policies has yet to emerge. Here we perform a model-based analysis of four types of school closure, ranging from the nationwide closure of all schools at the same time to reactive gradual closure, starting from class-by-class, then grades and finally the whole school. We consider policies based on triggers that are feasible to monitor, such as school absenteeism and national ILI surveillance system. We found that, under specific constraints on the average number of weeks lost per student, reactive school-by-school, gradual, and county-wide closure give comparable outcomes in terms of optimal infection attack rate reduction, peak incidence reduction or peak delay. Optimal implementations generally require short closures of one week each; this duration is long enough to break the transmission chain without leading to unnecessarily long periods of class interruption. Moreover, we found that gradual and county closures may be slightly more easily applicable in practice as they are less sensitive to the value of the excess absenteeism threshold triggering the start of the intervention. These findings suggest that policy makers could consider school closure policies more diffusely as response strategy to influenza epidemics and pandemics, and the fact that some countries already have some experience of gradual or regional closures for seasonal influenza outbreaks demonstrates that logistic and feasibility challenges of school closure strategies can be to some extent overcome.

  16. Flow simulation in piping system dead legs using second moment, closure and k-epsilon model

    International Nuclear Information System (INIS)

    Deutsch, E.; Mechitoua, N.; Mattei, J.D.

    1996-01-01

    This paper deals with an industrial application of second moment closure turbulence model in in numerical simulation of 3D turbulent flows in piping system dead legs. Calculations performed with the 3D ESTET code are presented which contrast the performance of k-epsilon eddy viscosity model and second moment closure turbulence models. Coarse (100 000), medium (400 000) and fine (1 500 000) meshes were used. The second moment closure performs significantly better than eddy viscosity model and predicts with a good agreement the vortex penetration in dead legs provided to use sufficiently refined meshes. The results point out the necessity to be able to perform calculations using fine mesh before introducing refined physical models such as second moment closure turbulence model in a numerical code. This study illustrates the ability of second moment closure turbulence model to simulate 3D turbulent industrial flows. Reynolds stress model computation does not require special care, the calculation is carried on as simply as the k-ξ one. The CPU time needed is less that twice the CPU time needed using k-ξ model. (authors)

  17. Comparison of two canopy reflectance models inversion for mapping forest crown closure using imaging spectroscopy

    NARCIS (Netherlands)

    Zeng, Y.; Schaepman, M.E.; Huang, H.A.; Bruin, de S.; Clevers, J.G.P.W.

    2008-01-01

    We compare the inversion of two canopy reflectance models to estimate forest crown closure (CC) using an EO-1 Hyperion image: the Kuusk¿Nilson forest reflectance and transmittance (FRT) model, and the Li¿Strahler geometric¿optical model. For predicting CC on a per-pixel basis, the FRT model

  18. Suture Choice in Lumbar Dural Closure Contributes to Variation in Leak Pressures: Experimental Model.

    Science.gov (United States)

    Ghobrial, George M; Maulucci, Christopher M; Viereck, Matthew J; Beygi, Sara; Chitale, Ameet; Prasad, Srinivas; Jallo, Jack; Heller, Joshua; Sharan, Ashwini D; Harrop, James S

    2017-07-01

    Open-label laboratory investigational study; non-animal surgical simulation. The authors perform a comparison of dural closure strength in a durotomy simulator across 2 different suture materials. Incidental durotomy leading to persistent cerebrospinal fluid leak adds considerable morbidity to spinal procedures, often complicating routine elective lumbar spinal procedures. Using an experimental durotomy simulation, the authors compare the strength of closure using Gore-Tex with other suture types and sizes, using various closure techniques. A comparison of dural closures was performed through an analysis of the peak pressure at which leakage occurred from a standardized durotomy closure in an established cerebrospinal fluid repair model with a premade L3 laminectomy. Nurolon was compared with Gore-Tex sutures sizes (for Gore-Tex, CV-6/5-0 and CV-5/4-0 was compared with Nurolon 4-0, 5-0, and 6-0). Thirty-six trials were performed with Nurolon 4-0, 5-0, and 6-0, whereas 21 trials were performed for 4-0 and 5-0 Gore-Tex. The mean peak pressure at which fluid leakage was observed was 21 cm H2O for Nurolon and 34 cm H2O for Gore-Tex. Irrespective of suture choice, all trials were grouped by closure technique: running suture, locked continuous, and interrupted suture. No significant difference was noted between the groups. For each of the 3 trials groups by closure technique, running, locked continuous, and interrupted, Gore-Tex closures had a significantly higher peak pressure to failure. Interrupted Gore-Tex was significantly higher than Interrupted Nurolon (P=0.007), running Gore-Tex was significantly higher than running Nurolon (P=0.034), and locked Gore-Tex was significantly higher than locked Nurolon (P=0.014). Durotomy closure in the lumbar spine with Gore-Tex suture may be a reasonable option for providing a watertight closure. In this laboratory study, Gore-Tex suture provided watertight dural closures that withstood higher peak pressures.

  19. A finite-element model for healing of cutaneous wounds combining contraction, angiogenesis and closure

    NARCIS (Netherlands)

    Vermolen, F.J.; Javierre, E.

    2011-01-01

    A simplified finite-element model for wound healing is proposed. The model takes into account the sequential steps of dermal regeneration, wound contraction, angiogenesis and wound closure. An innovation in the present study is the combination of the aforementioned partially overlapping processes,

  20. Modeling Carbonation of High-Level Waste Tank Integrity and Closure

    Directory of Open Access Journals (Sweden)

    Meeussen J.C.L.

    2013-07-01

    Full Text Available The Cementitious Barriers Partnership (CBP is focused on reducinguncertainties in current methodologies for assessing cementitious barrier performanceand increasing the consistency and transparency in the assessment process. Oneimportant set of US Department of Energy challenges is assessing the integrity andclosure of the high-level waste (HLW tanks that currently store millions of gallons ofhighly radioactive wastes. Many of these tanks are decades past their design lives, haveleaked or been overfilled, and must be emptied and closed to satisfy regulatoryagreements. Carbonation-induced corrosion has been identified as a primary degradationand possible failure mechanism for the HLW tanks prior to closure. After closure theimpact of carbonation (and concurrent oxidation may be to increase the release andshort-range transport of contaminants of concern. HLW tanks may be significantlyempty for many years (and possibly decades prior to closure; the performance of theclosed tank over centuries, if not millennia, must be assessed to evaluate the potentialrelease of residual radionuclides to the environment. CBP is developing models to evaluate a representative HLW tank closure scenarioincluding the potential impacts of carbonation on waste tanks prior to and post closure.CBP modeling tools, including LeachXS™/ORCHESTRA, are being used to simulatewaste tank carbonation, major constituent leaching, and contaminant releases to evaluatethe source term and near-field conditions. Simulations presented here include sensitivityanalysis for uncracked concrete to varying input parameters including composition,effective diffusivities, and thermodynamic parameters.

  1. An Analytical Model for Fatigue Life Prediction Based on Fracture Mechanics and Crack Closure

    DEFF Research Database (Denmark)

    Ibsø, Jan Behrend; Agerskov, Henning

    1996-01-01

    test specimens are compared with fatigue life predictions using a fracture mechanics approach. In the calculation of the fatigue life, the influence of the welding residual stresses and crack closure on the fatigue crack growth is considered. A description of the crack closure model for analytical...... of the analytical fatigue lives. Both the analytical and experimental results obtained show that the Miner rule may give quite unconservative predictions of the fatigue life for the types of stochastic loading studied....... determination of the fatigue life is included. Furthermore, the results obtained in studies of the various parameters that have an influence on the fatigue life, are given. A very good agreement between experimental and analytical results is obtained, when the crack closure model is used in determination...

  2. Complete hierarchies of SIR models on arbitrary networks with exact and approximate moment closure.

    Science.gov (United States)

    Sharkey, Kieran J; Wilkinson, Robert R

    2015-06-01

    We first generalise ideas discussed by Kiss et al. (2015) to prove a theorem for generating exact closures (here expressing joint probabilities in terms of their constituent marginal probabilities) for susceptible-infectious-removed (SIR) dynamics on arbitrary graphs (networks). For Poisson transmission and removal processes, this enables us to obtain a systematic reduction in the number of differential equations needed for an exact 'moment closure' representation of the underlying stochastic model. We define 'transmission blocks' as a possible extension of the block concept in graph theory and show that the order at which the exact moment closure representation is curtailed is the size of the largest transmission block. More generally, approximate closures of the hierarchy of moment equations for these dynamics are typically defined for the first and second order yielding mean-field and pairwise models respectively. It is frequently implied that, in principle, closed models can be written down at arbitrary order if only we had the time and patience to do this. However, for epidemic dynamics on networks, these higher-order models have not been defined explicitly. Here we unambiguously define hierarchies of approximate closed models that can utilise subsystem states of any order, and show how well-known models are special cases of these hierarchies. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  3. Closures and mergers of VNA home care agencies: a model for the study of causal factors.

    Science.gov (United States)

    Scalzi, C C; Meyer, M

    1991-01-01

    Recent closures and mergers of visiting nurses associations (VNAs) raise some potentially serious questions regarding access to home care for the elderly Medicare and Medicaid populations. While VNAs comprise less than 10 percent of the nation's certified home health agencies, they provide approximately 31 percent of all medicare home care (HCFA, 1989). In March of 1986 there were 524 visiting nurses associations nationally whereas today there remain only 495 (HCFA, 1990). A model identifying potential causes of VNA mortality is presented along with some preliminary results. VNA mortality is defined and measured by the date that Medicare certification is terminated as a result of VNA closure or merger.

  4. Comparison of pharyngocutaneous fistula closure with and without bacterial cellulose in a rat model.

    Science.gov (United States)

    Demir, Berat; Sarı, Murat; Binnetoglu, Adem; Yumusakhuylu, Ali Cemal; Filinte, Deniz; Tekin, İshak Özel; Bağlam, Tekin; Batman, Abdullah Çağlar

    2018-04-01

    The present study aimed to compare the effects of bacterial cellulose used for closure of pharyngocutaneous fistulae, a complication of total laryngectomy, with those of primary sutures in a rat model. Thirty female Sprague-Dawley underwent experimental pharyngoesophagotomy and were grouped depending on the material used for pharyngocutaneous fistula closure: group I, which received primary sutures alone, group II, which received bacterial cellulose alone; and group III, which received both. After 7 days, the rats were sacrificed. Pharyngocutaneous fistula development was assessed, the gross wound was inspected, and histological examination was conducted. Pharyngocutaneous fistulae developed in 12 rats (41%) in all: 6 from group I (21%), 4 from group II (14%) and 2 from group III (7%). Fibroblast density and inflammatory cell infiltration were significantly greater in group III than group I. We concluded that bacterial cellulose may be useful for pharyngocutaneous fistula closure. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Towards a transport model for epistemic UQ in RANS closures

    Science.gov (United States)

    Edeling, Wouter; Iaccarino, Gianluca

    2016-11-01

    Due to their computational efficiency, Reynold-Averaged Navier-Stokes (RANS) turbulence models remain a vital tool for modeling turbulent flows. However, it is well known that RANS predictions are locally corrupted by epistemic model-form uncertainty. Whereas some Uncertainty Quantification (UQ) approaches attempt to quantify this uncertainty by considering the model coefficients as random variables, we directly perturb the Reynold-stress tensor at locations in the flow domain where the modeling assumptions are likely to be invalid. Inferring the perturbations on a point-by-point basis would lead to a high-dimensional problem. To reduce the dimensionality, we propose separate model equations based on the transport of linear invariants of the anisotropy tensor. This provides us with a low-dimensional UQ framework where the invariant transport model decides on the magnitude and direction of the perturbations. Where the perturbations are small, the RANS result is recovered. Using traditional turbulence modeling practices we derive weak realizability constraints, and we will rely on Bayesian inference to calibrate the model on high-fidelity data. We will demonstrate our framework on a number of canonical flow problems where RANS models are prone to failure.

  6. Machine Learning-based discovery of closures for reduced models of dynamical systems

    Science.gov (United States)

    Pan, Shaowu; Duraisamy, Karthik

    2017-11-01

    Despite the successful application of machine learning (ML) in fields such as image processing and speech recognition, only a few attempts has been made toward employing ML to represent the dynamics of complex physical systems. Previous attempts mostly focus on parameter calibration or data-driven augmentation of existing models. In this work we present a ML framework to discover closure terms in reduced models of dynamical systems and provide insights into potential problems associated with data-driven modeling. Based on exact closure models for linear system, we propose a general linear closure framework from viewpoint of optimization. The framework is based on trapezoidal approximation of convolution term. Hyperparameters that need to be determined include temporal length of memory effect, number of sampling points, and dimensions of hidden states. To circumvent the explicit specification of memory effect, a general framework inspired from neural networks is also proposed. We conduct both a priori and posteriori evaluations of the resulting model on a number of non-linear dynamical systems. This work was supported in part by AFOSR under the project ``LES Modeling of Non-local effects using Statistical Coarse-graining'' with Dr. Jean-Luc Cambier as the technical monitor.

  7. An Economical PDF-Based Turbulence Closure Model for Cloud-Resolving Models and Global Climate Models

    Science.gov (United States)

    Krueger, S. K.; Bogenschutz, P.

    2011-12-01

    The representation of boundary layer clouds in GCMs has long been a challenge to climate modelers. The Multiscale Modeling Framework (MMF) embeds a coarse-grid 2D cloud-resolving model (CRM) in every GCM grid column. In MMF, the challenge becomes improving boundary layer cloud representation in coarse-grid CRMs in an economical way. Our solution has been to integrate several existing components: a prognostic SGS TKE equation, the assumed joint PDF method of Golaz et al. (2002), the diagnostic second-moment closure of Redelsperger and Sommeria (1986), the diagnostic closure for /line{w'w'w'} by Canuto et al. (2001), and a turbulence length scale related to the square root of subgrid-scale (SGS) turbulence kinetic energy (TKE) (Teixeira and Cheinet 2004) and eddy length scales. In comparison to the implementation of Golaz et al. (2002), our turbulence closure requires only one extra prognostic instead of seven. This makes our closure more economical, more portable, and better behaved. Our closure also uses a novel turbulence length scale that produces excellent scalablity with horizontal resolution. We implemented our approach in a CRM and and tested it against large-eddy simulation (LES) results. We also implemented it in a MMF and evaluated the results using global observations. The CRM that we used is SAM (System for Atmospheric Modeling) developed by Marat Khairoutdinov (Khairoutdinov and Randall 2003). SAM-PDF incorporates our new turbulence closure model. In SAM-PDF, the SGS TKE is prognosed, the turbulence length scale is related to the SGS TKE and eddy length scales, SGS condensation is diagnosed from the assumed joint PDF, the SGS buoyancy flux is diagnosed from the assumed joint PDF, and additional moments required by the PDF closure are diagnosed, so no additional prognostic equations are needed. The turbulence length scale is needed to parameterize the TKE dissipation rate and the eddy diffusivity. Cheng et al. (2010) showed that eddy diffusivity schemes

  8. Crack Closure Effects on Fatigue Crack Propagation Rates: Application of a Proposed Theoretical Model

    Directory of Open Access Journals (Sweden)

    José A. F. O. Correia

    2016-01-01

    Full Text Available Structural design taking into account fatigue damage requires a thorough knowledge of the behaviour of materials. In addition to the monotonic behaviour of the materials, it is also important to assess their cyclic response and fatigue crack propagation behaviour under constant and variable amplitude loading. Materials whenever subjected to fatigue cracking may exhibit mean stress effects as well as crack closure effects. In this paper, a theoretical model based on the same initial assumptions of the analytical models proposed by Hudak and Davidson and Ellyin is proposed to estimate the influence of the crack closure effects. This proposal based further on Walker’s propagation law was applied to the P355NL1 steel using an inverse analysis (back-extrapolation of experimental fatigue crack propagation results. Based on this proposed model it is possible to estimate the crack opening stress intensity factor, Kop, the relationship between U=ΔKeff/ΔK quantity and the stress intensity factor, the crack length, and the stress ratio. This allows the evaluation of the influence of the crack closure effects for different stress ratio levels, in the fatigue crack propagation rates. Finally, a good agreement is found between the proposed theoretical model and the analytical models presented in the literature.

  9. West Closure Complex Pump Intake Model, New Orleans, Louisiana

    Science.gov (United States)

    2013-02-01

    in Q/(d5 g)1/2 of 1.0. S/d = 1.3. No information on velocity uniformity at the pump impeller was available. 7. The Davis Pond pump station in New... Pond have successful operation at Q/(d5 g)1/2 of 1.35, 0.87, 1.0, and 1.3, respectively, but no velocity information at the pump impeller was...simulation, it was necessary to mini - mize head loss in the model discharge lines. The WCC model had long ERDC/CHL TR-13-1 23 Figure 17. Approach walls

  10. Elastic instability model of rapid beak closure in hummingbirds.

    Science.gov (United States)

    Smith, M L; Yanega, G M; Ruina, A

    2011-08-07

    The hummingbird beak, specialized for feeding on floral nectars, is also uniquely adapted to eating flying insects. During insect capture the beak often appears to close at a rate that cannot be explained by direct muscular action alone. Here we show that the lower jaw of hummingbirds has a shape and compliance that allows for a controlled elastic snap. Furthermore, hummingbirds have the musculature needed to independently bend and twist the sides of the lower jaw. According to both our simple physical model and our elastic instability calculation, the jaw can be smoothly opened and then snapped closed through an appropriate sequence of bending and twisting actions by the muscles of the lower jaw. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. Simulated precipitation diurnal cycles over East Asia using different CAPE-based convective closure schemes in WRF model

    Science.gov (United States)

    Yang, Ben; Zhou, Yang; Zhang, Yaocun; Huang, Anning; Qian, Yun; Zhang, Lujun

    2018-03-01

    Closure assumption in convection parameterization is critical for reasonably modeling the precipitation diurnal variation in climate models. This study evaluates the precipitation diurnal cycles over East Asia during the summer of 2008 simulated with three convective available potential energy (CAPE) based closure assumptions, i.e. CAPE-relaxing (CR), quasi-equilibrium (QE), and free-troposphere QE (FTQE) and investigates the impacts of planetary boundary layer (PBL) mixing, advection, and radiation on the simulation by using the weather research and forecasting model. The sensitivity of precipitation diurnal cycle to PBL vertical resolution is also examined. Results show that the precipitation diurnal cycles simulated with different closures all exhibit large biases over land and the simulation with FTQE closure agrees best with observation. In the simulation with QE closure, the intensified PBL mixing after sunrise is responsible for the late-morning peak of convective precipitation, while in the simulation with FTQE closure, convective precipitation is mainly controlled by advection cooling. The relative contributions of different processes to precipitation formation are functions of rainfall intensity. In the simulation with CR closure, the dynamical equilibrium in the free troposphere still can be reached, implying the complex cause-effect relationship between atmospheric motion and convection. For simulations in which total CAPE is consumed for the closures, daytime precipitation decreases with increased PBL resolution because thinner model layer produces lower convection starting layer, leading to stronger downdraft cooling and CAPE consumption. The sensitivity of the diurnal peak time of precipitation to closure assumption can also be modulated by changes in PBL vertical resolution. The results of this study help us better understand the impacts of various processes on the precipitation diurnal cycle simulation.

  12. Accelerated wound closure in a diabetic mouse model after exposure to phenanthrenequinone.

    Science.gov (United States)

    Polack, Glenda; McCray, Victor; Tyner, Tim; Kane, Saben; Vu, Kennedy; Yamaguchi, Kent; Merriman, Jarrad; Ishimoto, Michael; Hasson, Alam; Sian, Kenty; Yamaguchi, Kent T

    2013-06-01

    Reactive oxygen species (ROS) have been shown to be important in wound healing by promoting angiogenesis (also mentioned by Ushio-Fukai and Nakamura). Likewise ROS have been implicated by toxicological studies as a primary mechanism of air pollution-associated morbidity. We sought to determine how exposure to a reactive diesel exhaust chemical (phenanthrenequinone [PQ]), which promotes formation of ROS and is considered an air pollutant, would affect wound healing. Since wound healing is compromised in diabetic (db) individuals, we examined the effects of PQ on wound healing in a db mouse model. db mice consumed PQ-containing chow for a short period (2 weeks) before wounding and through generations. Wound closure rates and wound vascularization were evaluated 10 days after wounding. The effects of PQ on endothelial cell proliferation and ROS generation in vitro were also measured. db mice exposed to short-term PQ and PQ-exposed first-generation db mice demonstrated the highest closure rates, significantly better than control db mice (P < 0.05). Furthermore, a higher concentration of PQ in sera of db mice coincides with the higher rate of closure. PQ was also shown to produce ROS in cell culture and stimulate endothelial cell proliferation at nanomolar concentrations. Second- and third-generation db mice exposed to PQ did not show improved wound healing. This study suggests that the free radical-generating air pollutant PQ enhances wound closure in the db mouse model possibly by stimulating angiogenesis, as suggested by in vitro results. We speculate that PQ may increase oxidation levels systemically and therefore help modulate inflammation at the wound site. Alternatively, antioxidant mechanisms recruited for wound healing may interfere with PQ metabolism and elimination as it accumulates in sera. Generational resistance to improve wound healing in PQ-exposed db mice could also be due to disturbances in metabolism caused by continuous exposure. In either case

  13. Floating Node Method and Virtual Crack Closure Technique for Modeling Matrix Cracking-Delamination Migration

    Science.gov (United States)

    DeCarvalho, Nelson V.; Chen, B. Y.; Pinho, Silvestre T.; Baiz, P. M.; Ratcliffe, James G.; Tay, T. E.

    2013-01-01

    A novel approach is proposed for high-fidelity modeling of progressive damage and failure in composite materials that combines the Floating Node Method (FNM) and the Virtual Crack Closure Technique (VCCT) to represent multiple interacting failure mechanisms in a mesh-independent fashion. In this study, the approach is applied to the modeling of delamination migration in cross-ply tape laminates. Delamination, matrix cracking, and migration are all modeled using fracture mechanics based failure and migration criteria. The methodology proposed shows very good qualitative and quantitative agreement with experiments.

  14. A model for prioritizing landfills for remediation and closure: A case study in Serbia.

    Science.gov (United States)

    Ubavin, Dejan; Agarski, Boris; Maodus, Nikola; Stanisavljevic, Nemanja; Budak, Igor

    2018-01-01

    The existence of large numbers of landfills that do not fulfill sanitary prerequisites presents a serious hazard for the environment in lower income countries. One of the main hazards is landfill leachate that contains various pollutants and presents a threat to groundwater. Groundwater pollution from landfills depends on various mutually interconnected factors such as the waste type and amount, the amount of precipitation, the landfill location characteristics, and operational measures, among others. Considering these factors, lower income countries face a selection problem where landfills urgently requiring remediation and closure must be identified from among a large number of sites. The present paper proposes a model for prioritizing landfills for closure and remediation based on multicriteria decision making, in which the hazards of landfill groundwater pollution are evaluated. The parameters for the prioritization of landfills are the amount of waste disposed, the amount of precipitation, the vulnerability index, and the rate of increase of the amount of waste in the landfill. Verification was performed using a case study in Serbia where all municipal landfills were included and 128 landfills were selected for prioritization. The results of the evaluation of Serbian landfills, prioritizing sites for closure and remediation, are presented for the first time. Critical landfills are identified, and prioritization ranks for the selected landfills are provided. Integr Environ Assess Manag 2018;14:105-119. © 2017 SETAC. © 2017 SETAC.

  15. Modelling of Non-Premixed Turbulent Combustion of Hydrogen using Conditional Moment Closure Method

    International Nuclear Information System (INIS)

    Noor, M M; Hairuddin, A Aziz; Wandel, Andrew P; Yusaf, T F

    2012-01-01

    Most of the electricity generation and energy for transport is still generated by the conversion of chemical to mechanical energy by burning the fuels in the combustion chamber. Regulation for pollution and the demand for more fuel economy had driven worldwide researcher to focus on combustion efficiency. In order to reduce experimental cost, accurate modelling and simulation is very critical step. Taylor series expansion was utilised to reduce the error term for the discretization. FORTRAN code was used to execute the discretized partial differential equation. Hydrogen combustion was simulated using Conditional Moment Closure (CMC) model. Combustion of hydrogen with oxygen was successfully simulated and reported in this paper.

  16. A new discrete dynamic model of ABA-induced stomatal closure predicts key feedback loops.

    Directory of Open Access Journals (Sweden)

    Réka Albert

    2017-09-01

    Full Text Available Stomata, microscopic pores in leaf surfaces through which water loss and carbon dioxide uptake occur, are closed in response to drought by the phytohormone abscisic acid (ABA. This process is vital for drought tolerance and has been the topic of extensive experimental investigation in the last decades. Although a core signaling chain has been elucidated consisting of ABA binding to receptors, which alleviates negative regulation by protein phosphatases 2C (PP2Cs of the protein kinase OPEN STOMATA 1 (OST1 and ultimately results in activation of anion channels, osmotic water loss, and stomatal closure, over 70 additional components have been identified, yet their relationships with each other and the core components are poorly elucidated. We integrated and processed hundreds of disparate observations regarding ABA signal transduction responses underlying stomatal closure into a network of 84 nodes and 156 edges and, as a result, established those relationships, including identification of a 36-node, strongly connected (feedback-rich component as well as its in- and out-components. The network's domination by a feedback-rich component may reflect a general feature of rapid signaling events. We developed a discrete dynamic model of this network and elucidated the effects of ABA plus knockout or constitutive activity of 79 nodes on both the outcome of the system (closure and the status of all internal nodes. The model, with more than 1024 system states, is far from fully determined by the available data, yet model results agree with existing experiments in 82 cases and disagree in only 17 cases, a validation rate of 75%. Our results reveal nodes that could be engineered to impact stomatal closure in a controlled fashion and also provide over 140 novel predictions for which experimental data are currently lacking. Noting the paucity of wet-bench data regarding combinatorial effects of ABA and internal node activation, we experimentally confirmed

  17. Influence of Embedded Fibers and an Epithelium Layer on the Glottal Closure Pattern in a Physical Vocal Fold Model

    Science.gov (United States)

    Xuan, Yue; Zhang, Zhaoyan

    2014-01-01

    Purpose: The purpose of this study was to explore the possible structural and material property features that may facilitate complete glottal closure in an otherwise isotropic physical vocal fold model. Method: Seven vocal fold models with different structural features were used in this study. An isotropic model was used as the baseline model, and…

  18. 488-1D Ash Basin closure cap help modeling- Microdrain® liner option

    Energy Technology Data Exchange (ETDEWEB)

    Dyer, J. A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-08-03

    At the request of Area Completion Engineering and in support of the 488-1D Ash Basin closure, the Savannah River National Laboratory (SRNL) performed hydrologic simulations of the revised 488-1D Ash Basin closure cap design using the Hydrologic Evaluation of Landfill Performance (HELP) model. The revised design substitutes a MicroDrain Liner®—60-mil low-density polyethylene geomembrane structurally integrated with 130-mil drainage layer—for the previously planned drainage/barrier system—300-mil geosynthetic drainage layer (GDL), 300-mil geosynthetic clay liner (GCL), and 6-inch common fill soil layer. For a 25-year, 24-hour storm event, HELP model v3.07 was employed to (1) predict the peak maximum daily hydraulic head for the geomembrane layer, and (2) ensure that South Carolina Department of Health and Environmental Control (SCDHEC) requirements for the barrier layer (i.e., ≤ 12 inches hydraulic head on top of a barrier having a saturated hydraulic conductivity ≤ 1.0E-05 cm/s) will not be exceeded. A 25-year, 24-hour storm event at the Savannah River Site (SRS) is 6.1 inches rainfall (Weber 1998). HELP model v3.07 results based upon the new planned cap design suggest that the peak maximum daily hydraulic head on the geomembrane barrier layer will be 0.15 inches for a minimum slope equal to 3%, which is two orders of magnitude below the SCDHEC upper limit of 12 inches.

  19. Internal vacuum-assisted closure device in the swine model of severe liver injury

    Directory of Open Access Journals (Sweden)

    Everett Christopher B

    2012-12-01

    Full Text Available Abstract Objectives The authors present a novel approach to nonresectional therapy in major hepatic trauma utilizing intraabdominal perihepatic vacuum assisted closure (VAC therapy in the porcine model of Grade V liver injury. Methods A Grade V injury was created in the right lobe of the liver in a healthy pig. A Pringle maneuver was applied (4.5 minutes total clamp time and a vacuum assisted closure device was placed over the injured lobe and connected to suction. The device consisted of a perforated plastic bag placed over the liver, followed by a 15 cm by 15cm VAC sponge covered with a nonperforated plastic bag. The abdomen was closed temporarily. Blood loss, cardiopulmonary parameters and bladder pressures were measured over a one-hour period. The device was then removed and the animal was euthanized. Results Feasibility of device placement was demonstrated by maintenance of adequate vacuum suction pressures and seal. VAC placement presented no major technical challenges. Successful control of ongoing liver hemorrhage was achieved with the VAC. Total blood loss was 625 ml (20ml/kg. This corresponds to class II hemorrhagic shock in humans and compares favorably to previously reported estimated blood losses with similar grade liver injuries in the swine model. No post-injury cardiopulmonary compromise or elevated abdominal compartment pressures were encountered, while hepatic parenchymal perfusion was maintained. Conclusion These data demonstrate the feasibility and utility of a perihepatic negative pressure device for the treatment of hemorrhage from severe liver injury in the porcine model.

  20. Road Closures

    Data.gov (United States)

    Montgomery County of Maryland — This is an up to date map of current road closures in Montgomery County.This dataset is updated every few minutes from the Department of Transportation road closure...

  1. Engineering sustainable ecosystems: using GIS-based habitat modeling for oil sands mine reclamation and closure planning

    International Nuclear Information System (INIS)

    Seel, K.

    1997-01-01

    A GIS model was built to predict the climax vegetation habitat types on reclaimed mine surfaces in the Fort McMurray region of the Mid-Boreal Mixedwood Ecoregion of northwestern Alberta. Regional vegetation habitat types were classified by digital remote sensing using Landsat Thematic Mapper satellite data. Terrain data was derived from a high-resolution digital elevation model. The validated model was applied to the GIS database of Syncrude Canada's Mildred Lake Mine to predict future vegetation patterns based on the final closure mine surface. The results were compared to revegetation and closure plans created by experts to analyze performance and sustainability of reclamation efforts

  2. Sutureless closure of scleral wounds in animal models by the use of laser welded biocompatible patches

    Science.gov (United States)

    Rossi, Francesca; Matteini, Paolo; Menabuoni, Luca; Lenzetti, Ivo; Pini, Roberto

    2011-03-01

    The common procedures used to seal the scleral or conjunctival injuries are based on the traditional suturing techniques, that may induce foreign body reaction during the follow up, with subsequent inflammation and distress for the patient. In this work we present an experimental study on the laser welding of biocompatible patches onto ocular tissues, for the closure of surgical or trauma wounds. The study was performed ex vivo in animal models (porcine eyes). A penetrating perforation of the ocular tissue was performed with a surgical knife. The wound walls were approximated, and a biocompatible patch was put onto the outer surface of the tissue, in order to completely cover the wound as a plaster. The patches were prepared with a biocompatible and biodegradable polymer, showing high mechanical strength, good elasticity, high permeability for vapour and gases and rather low biodegradation. During preparation, Indocyanine Green (ICG) was included in the biopolymeric matrix, so that the films presented high absorption at 810 nm. Effective adhesion of the membranes to the ocular tissues was obtained by using diode laser light emitted from an 810 nm diode laser and delivered by means of a 300 μm core diameter optical fiber, to produce spots of local film/tissue adhesion, due to the photothermal effect at the interface. The result is an immediate closure of the wound, thus reducing post-operative complications due to inflammation.

  3. A Dual Regime Reactive Transport Model for Simulation of High Level Waste Tank Closure Scenarios - 13375

    International Nuclear Information System (INIS)

    Sarkar, Sohini; Kosson, David S.; Brown, Kevin; Garrabrants, Andrew C.; Meeussen, Hans; Van der Sloot, Hans

    2013-01-01

    A numerical simulation framework is presented in this paper for estimating evolution of pH and release of major species from grout within high-level waste tanks after closure. This model was developed as part of the Cementitious Barriers Partnership. The reactive transport model consists of two parts - (1) transport of species, and (2) chemical reactions. The closure grout can be assumed to have varying extents of cracking and composition for performance assessment purposes. The partially or completely degraded grouted tank is idealized as a dual regime system comprising of a mobile region having solid materials with cracks and macro-pores, and an immobile/stagnant region having solid matrix with micropores. The transport profiles of the species are calculated by incorporating advection of species through the mobile region, diffusion of species through the immobile/stagnant region, and exchange of species between the mobile and immobile regions. A geochemical speciation code in conjunction with the pH dependent test data for a grout material is used to obtain a mineral set that best describes the trends in the test data of the major species. The dual regime reactive transport model predictions are compared with the release data from an up-flow column percolation test. The coupled model is then used to assess effects of crack state of the structure, rate and composition of the infiltrating water on the pH evolution at the grout-waste interface. The coupled reactive transport model developed in this work can be used as part of the performance assessment process for evaluating potential risks from leaching of a cracked tank containing elements of human health and environmental concern. (authors)

  4. Quantitative modelling of the closure of meso-scale parallel currents in the nightside ionosphere

    Directory of Open Access Journals (Sweden)

    A. Marchaudon

    2004-01-01

    Full Text Available On 12 January 2000, during a northward IMF period, two successive conjunctions occur between the CUTLASS SuperDARN radar pair and the two satellites Ørsted and FAST. This situation is used to describe and model the electrodynamic of a nightside meso-scale arc associated with a convection shear. Three field-aligned current sheets, one upward and two downward on both sides, are observed. Based on the measurements of the parallel currents and either the conductance or the electric field profile, a model of the ionospheric current closure is developed along each satellite orbit. This model is one-dimensional, in a first attempt and a two-dimensional model is tested for the Ørsted case. These models allow one to quantify the balance between electric field gradients and ionospheric conductance gradients in the closure of the field-aligned currents. These radar and satellite data are also combined with images from Polar-UVI, allowing for a description of the time evolution of the arc between the two satellite passes. The arc is very dynamic, in spite of quiet solar wind conditions. Periodic enhancements of the convection and of electron precipitation associated with the arc are observed, probably associated with quasi-periodic injections of particles due to reconnection in the magnetotail. Also, a northward shift and a reorganisation of the precipitation pattern are observed, together with a southward shift of the convection shear. Key words. Ionosphere (auroral ionosphere; electric fields and currents; particle precipitation – Magnetospheric physics (magnetosphere-ionosphere interactions

  5. Predicting acute copper toxicity to valve closure behavior in the freshwater clam Corbicula fluminea supports the biotic ligand model.

    Science.gov (United States)

    Liao, Chung-Min; Jou, Li-John; Lin, Chieh-Ming; Chiang, Kuo-Chin; Yeh, Ching-Hung; Chou, Berry Yun-Hua

    2007-06-01

    The objective of this paper is to employ biotic ligand model (BLM) to link between acute copper (Cu) toxicity and its effect on valve closure behavior of freshwater clam Corbicula fluminea in order to further support for the BLM that potentially offers a rapid and cost-effective method to conduct the acute toxicity tests for freshwater clam exposed to waterborne Cu. Reanalysis of published experimental data of C. fluminea closure daily rhythm and dose-response profiles based on the laboratory-acclimated clams showed that a BLM-based Hill model best described the free Cu(2+)-activity-valve closure response relationships. Our proposed Cu-BLM-Corbicula model shows that free ionic form of waterborne Cu binds specifically to a biotic ligand (i.e., clam gills) and impairs normal valve closure behavior, indicating that a fixed-level of metal accumulation at a biotic ligand is required to elicit specific biological effects. With derived mechanistic-based Cu-BLM-Corbicula model, we show that the site-specific EC50(t) and valve closure behavior at any integrated time can be well predicted, indicating that our model has the potential to develop a biomonitoring system as a bioassay tool to on-line measure waterborne Cu levels in aquatic systems. Our results confirm that BLM can be improved to analytically and rigorously describe the bioavailable fraction of metal causing toxicity to valve closure behavior in freshwater C. fluminea. We suggest that the Cu-BLM-Corbicula model can be used to assist in developing technically defensible site-specific water quality criteria and performing ecological risk assessment and to promote more focused and efficient uses of resources in the regulation and control of metals and the protection of the aquatic ecosystems.

  6. Using agent-based modeling to depict basin closure in the Naivasha basin, Kenya: a framework of analysis

    NARCIS (Netherlands)

    van Oel, P.R.; van der Veen, A.

    2011-01-01

    A spatially-explicit agent-based modeling (ABM) approach is applied for depicting the processes leading to basin closure in the Naivasha basin by representing interdependencies between water availability and water use. Modeling the dynamics of water use and water availability yields patterns of

  7. Cloud-turbulence interactions: Sensitivity of a general circulation model to closure assumptions

    International Nuclear Information System (INIS)

    Brinkop, S.; Roeckner, E.

    1993-01-01

    Several approaches to parameterize the turbulent transport of momentum, heat, water vapour and cloud water for use in a general circulation model (GCM) have been tested in one-dimensional and three-dimensional model simulations. The schemes differ with respect to their closure assumptions (conventional eddy diffusivity model versus turbulent kinetic energy closure) and also regarding their treatment of cloud-turbulence interactions. The basis properties of these parameterizations are discussed first in column simulations of a stratocumulus-topped atmospheric boundary layer (ABL) under a strong subsidence inversion during the KONTROL experiment in the North Sea. It is found that the K-models tend to decouple the cloud layer from the adjacent layers because the turbulent activity is calculated from local variables. The higher-order scheme performs better in this respect because internally generated turbulence can be transported up and down through the action of turbulent diffusion. Thus, the TKE-scheme provides not only a better link between the cloud and the sub-cloud layer but also between the cloud and the inversion as a result of cloud-top entrainment. In the stratocumulus case study, where the cloud is confined by a pronounced subsidence inversion, increased entrainment favours cloud dilution through enhanced evaporation of cloud droplets. In the GCM study, however, additional cloud-top entrainment supports cloud formation because indirect cloud generating processes are promoted through efficient ventilation of the ABL, such as the enhanced moisture supply by surface evaporation and the increased depth of the ABL. As a result, tropical convection is more vigorous, the hydrological cycle is intensified, the whole troposphere becomes warmer and moister in general and the cloudiness in the upper part of the ABL is increased. (orig.)

  8. Evaluation of in vivo biocompatibility of different devices for interventional closure of the patent ductus arteriosus in an animal model

    OpenAIRE

    Sigler, M; Handt, S; Seghaye, M; von Bernuth, G; Grabitz, R

    2000-01-01

    OBJECTIVE—To evaluate the in vivo biocompatibility of three different devices following interventional closure of a patent ductus arteriosus (PDA) in an animal model.
MATERIALS AND METHODS—A medical grade stainless steel coil (n = 8), a nickel/titanium coil (n = 10), and a polyvinylalcohol foam plug knitted on a titanium wire frame (n = 11) were used for interventional closure of PDA in a neonatal lamb model. The PDA had been maintained by repetitive angioplasty. Between one and 278 days afte...

  9. An analytical model which combines roughness- and plasticity- induced fatigue crack closure

    Science.gov (United States)

    Chen, Nong

    In this study an analytical PICC-RICC Model was developed to describe better the near-threshold fatigue behavior. The PICC-RICC Model was built upon a strip-yield type PICC model originally proposed by Newman and later modified by Hou and Lawrence. A zigzag crack growth path was introduced to simulate surface roughness. The two opposing crack surfaces were considered to be translated and thus mismatched by the mixed-mode displacements occurring near the deflected crack tip. The model is powerful and unique in that it combines the effects of RICC and PICC. Thus, the gradual transition from RICC to PICC dominated crack closure is handled naturally by this model. The influences of the geometrical features of the surface roughness, R-ratio and the cyclic load range on RICC were examined using the PICC-RICC Model. Near-threshold fatigue behavior of various materials was predicted. The effect of microstructure on the RICC level was studied. The predicted results compared favorably with experimental data. The fatigue notch size effect was investigated using the PICC-RICC model. The initial crack length (asb{i}) for propagation was estimated. The predicted notch fatigue strength compared favorably with the Initiation-Propagation (I-P) Model prediction and test data. The existence of a "worst case notch" previously postulated using the I-P Model was confirmed.

  10. 488-1D Ash basin closure cap help modeling-Microdrain® liner option

    Energy Technology Data Exchange (ETDEWEB)

    Dyer, J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-09-06

    At the request of Area Completion Engineering and in support of the 488-1D Ash Basin closure, the Savannah River National Laboratory (SRNL) performed hydrologic simulations of the revised 488-1D Ash Basin closure cap design using the Hydrologic Evaluation of Landfill Performance (HELP) model. The revised design substitutes a MicroDrain Liner®—50-mil linear low-density polyethylene geomembrane structurally integrated with 130-mil drainage layer—for the previously planned drainage/barrier system—300-mil geosynthetic drainage layer (GDL), 300-mil geosynthetic clay liner (GCL), and 6-inch common fill soil layer. For a 25-year, 24-hour storm event, HELP model v3.07 was employed to (1) predict the peak maximum daily hydraulic head for the geomembrane layer, and (2) ensure that South Carolina Department of Health and Environmental Control (SCDHEC) requirements for the barrier layer (i.e., ≤ 12 inches hydraulic head on top of a barrier having a saturated hydraulic conductivity ≤ 1.0E-05 cm/s) will not be exceeded. A 25-year, 24-hour storm event at the Savannah River Site (SRS) is 6.1 inches rainfall (Weber 1998). HELP model v3.07 results based upon the new planned cap design suggest that the peak maximum daily hydraulic head on the geomembrane barrier layer will be 0.179 inches for a minimum slope equal to 3%, which is approximately two orders of magnitude below the SCDHEC upper limit of 12 inches.

  11. Towards closure between measured and modelled UV under clear skies at four diverse sites

    Science.gov (United States)

    Badosa, J.; McKenzie, R. L.; Kotkamp, M.; Calbó, J.; González, J. A.; Johnston, P. V.; O'Neill, M.; Anderson, D. J.

    2007-06-01

    The purpose of this work is determine the extent of closure between measurements and models of UV irradiances at diverse sites using state of the art instruments, models, and the best available data as inputs to the models. These include information about aerosol optical depth (unfortunately not extending down as far into the UVB region as desirable because such information is not generally available), ozone column amounts, as well as vertical profiles of temperature. We concentrate on clear-sky irradiances, and report the results in terms of UV Index (UVI). Clear-sky data from one year of measurements at each of four diverse sites (Lauder - New Zealand, Mauna Loa Observatory - Hawaii, Boulder - Colorado, and Melbourne - Australia) have been analysed in detail, also taking account of different measurements of ozone, including satellite-derived values, as well as ground measured values, both from Dobson instruments and as retrieved from the UV spectra under study. Previous studies have generally focussed on data from a single site, and for shorter periods. As such, it is the most comprehensive study of its kind to date. At Lauder, which is the cleanest low altitude site, we obtained agreement between measurement and model at 5% level, which is consistent with the best agreement found previously. At Mauna Loa Observatory, similar agreement was achieved, but model calculations need to allow for reflections from cloud that are present below the observatory. At this site, there are occasional problems with using satellite-derived ozone. At Boulder, mean agreements were similar but the dispersion around the mean was slightly larger, corresponding to larger uncertainties in the aerosol inputs to the model. However, at Melbourne, which is the only non-NDACC (Network for the Detection of Atmospheric Composition Change) site, there remain unexplained discrepancies. The measured values are significantly lower than the calculated values. We investigate the extent to which this

  12. Modelling the closure-related geochemical evolution of groundwater at a former uranium mine.

    Science.gov (United States)

    Bain, J G; Mayer, K U; Blowes, D W; Frind, E O; Molson, J W; Kahnt, R; Jenk, U

    2001-11-01

    A newly developed reactive transport model was used to evaluate the potential effects of mine closure on the geochemical evolution in the aquifer downgradient from a mine site. The simulations were conducted for the Königstein uranium mine located in Saxony, Germany. During decades of operation, uranium at the former mine site had been extracted by in situ acid leaching of the ore underground, while the mine was maintained in a dewatered condition. One option for decommissioning is to allow the groundwater level to rise to its natural level, flooding the mine workings. As a result, pore water containing high concentrations of dissolved metals, radionuclides, and sulfate may be released. Additional contamination may arise due to the dissolution of minerals contained in the aquifer downgradient of the mine. On the other hand, dissolved metals may be attenuated by reactions within the aquifer. The geochemical processes and interactions involved are highly non-linear and their impact on the quality of the groundwater and surface water downstream of the mine is not always intuitive. The multicomponent reactive transport model MIN3P, which can describe mineral dissolution-precipitation reactions, aqueous complexation, and oxidation-reduction reactions, is shown to be a powerful tool for investigating these processes. The predictive capabilities of the model are, however, limited by the availability of key geochemical parameters such as the presence and quantities of primary and secondary mineral phases. Under these conditions, the model can provide valuable insight by means of sensitivity analyses.

  13. Development and validation of a laparoscopic hysterectomy cuff closure simulation model for surgical training.

    Science.gov (United States)

    Tunitsky-Bitton, Elena; Propst, Katie; Muffly, Tyler

    2016-03-01

    The number of robotically assisted hysterectomies is increasing, and therefore, the opportunities for trainees to become competent in performing traditional laparoscopic hysterectomy are decreasing. Simulation-based training is ideal for filling this gap in training. The objective of the study was to design a surgical model for training in laparoscopic vaginal cuff closure and to present evidence of its validity and reliability as an assessment and training tool. Participants included gynecology staff and trainees at 2 tertiary care centers. Experienced surgeons were also recruited at the combined International Urogynecologic Association and American Urogynecologic Society scientific meeting. Participants included 19 experts and 21 trainees. All participants were recorded using the laparoscopic hysterectomy cuff closure simulation model. The model was constructed using the an advanced uterine manipulation system with a sacrocolopexy tip/vaginal stent, a vaginal cuff constructed from neoprene material and lined with a swimsuit material (nylon and spandex) secured to the vaginal stent with a plastic cable tie. The uterine manipulation system was attached to the fundamentals of laparoscopic surgery laparoscopic training box trainer using a metal bracket. Performance was evaluated using the Global Operative Assessment of Laparoscopic Skills scale. In addition, needle handling, knot tying, and incorporation of epithelial edge were also evaluated. The Student t test was used to compare the scores and the operating times between the groups. Intrarater reliability between the scores by the 2 masked experts was measured using the interclass correlation coefficient. Total and annual experience with laparoscopic suturing and specifically vaginal cuff closure varied greatly among the participants. For the construct validity, the participants in the expert group received significantly higher scores in each of the domains of the Global Operative Assessment of Laparoscopic Skills

  14. Development of high fidelity soot aerosol dynamics models using method of moments with interpolative closure

    KAUST Repository

    Roy, Subrata P.

    2014-01-28

    The method of moments with interpolative closure (MOMIC) for soot formation and growth provides a detailed modeling framework maintaining a good balance in generality, accuracy, robustness, and computational efficiency. This study presents several computational issues in the development and implementation of the MOMIC-based soot modeling for direct numerical simulations (DNS). The issues of concern include a wide dynamic range of numbers, choice of normalization, high effective Schmidt number of soot particles, and realizability of the soot particle size distribution function (PSDF). These problems are not unique to DNS, but they are often exacerbated by the high-order numerical schemes used in DNS. Four specific issues are discussed in this article: the treatment of soot diffusion, choice of interpolation scheme for MOMIC, an approach to deal with strongly oxidizing environments, and realizability of the PSDF. General, robust, and stable approaches are sought to address these issues, minimizing the use of ad hoc treatments such as clipping. The solutions proposed and demonstrated here are being applied to generate new physical insight into complex turbulence-chemistry-soot-radiation interactions in turbulent reacting flows using DNS. © 2014 Copyright Taylor and Francis Group, LLC.

  15. Hamiltonian fluid closures of the Vlasov-Ampère equations: From water-bags to N moment models

    Energy Technology Data Exchange (ETDEWEB)

    Perin, M.; Chandre, C.; Tassi, E. [Aix-Marseille Université, Université de Toulon, CNRS, CPT UMR 7332, 13288 Marseille (France); Morrison, P. J. [Department of Physics and Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712-1060 (United States)

    2015-09-15

    Moment closures of the Vlasov-Ampère system, whereby higher moments are represented as functions of lower moments with the constraint that the resulting fluid system remains Hamiltonian, are investigated by using water-bag theory. The link between the water-bag formalism and fluid models that involve density, fluid velocity, pressure and higher moments is established by introducing suitable thermodynamic variables. The cases of one, two, and three water-bags are treated and their Hamiltonian structures are provided. In each case, we give the associated fluid closures and we discuss their Casimir invariants. We show how the method can be extended to an arbitrary number of fields, i.e., an arbitrary number of water-bags and associated moments. The thermodynamic interpretation of the resulting models is discussed. Finally, a general procedure to derive Hamiltonian N-field fluid models is proposed.

  16. Closure requirements

    International Nuclear Information System (INIS)

    Hutchinson, I.P.G.; Ellison, R.D.

    1992-01-01

    Closure of a waste management unit can be either permanent or temporary. Permanent closure may be due to: economic factors which make it uneconomical to mine the remaining minerals; depletion of mineral resources; physical site constraints that preclude further mining and beneficiation; environmental, regulatory or other requirements that make it uneconomical to continue to develop the resources. Temporary closure can occur for a period of several months to several years, and may be caused by factors such as: periods of high rainfall or snowfall which prevent mining and waste disposal; economic circumstances which temporarily make it uneconomical to mine the target mineral; labor problems requiring a cessation of operations for a period of time; construction activities that are required to upgrade project components such as the process facilities and waste management units; and mine or process plant failures that require extensive repairs. Permanent closure of a mine waste management unit involves the provision of durable surface containment features to protect the waters of the State in the long-term. Temporary closure may involve activities that range from ongoing maintenance of the existing facilities to the installation of several permanent closure features in order to reduce ongoing maintenance. This paper deals with the permanent closure features

  17. A New Acute Attack of Angle Closure Glaucoma Animal Model with Healon 5

    Directory of Open Access Journals (Sweden)

    Silvania Y. F. Lau

    2011-05-01

    Full Text Available Acute angle closure glaucoma (AACG is an ocular emergency and sight -threatening disease in which the intraocular ocular pressure (IOP rises suddenly due to blockage of aqueous humor outflow. It can cause permanent loss in visual acuity and visual field. In animal study, the well-established model to study AACG is by fluid infusion and by adjusting the bottle level, a high IOP can be induced in a few seconds. However, there is no blockage of aqueous outflow and the pressure rise is unrealistically fast. To mimic human AACG, we suggest to use Healon 5, an ophthalmic viscosurgical device, which is injected intracamerally to block the aqueous outflow. The IOP is allowed to build up naturally. We found that, with this technique, the IOP elevated at a rate of 0.57 mmHg/min before it hit 40 mmHg, which is considered as AACG in human. The maximum IOP registered was above 70 mmHg. Thinning of retinal nerve fiber layer (RNFL and neural cells lost were seen. Visual function evaluated by ERG showed reduction in a-wave, b-wave, photopic negative response (PhNR and oscillatory potentials (OPs activities. In conclusion, Healon 5 is effective in inducing acute transient rise in IOP which mimics human AACG.

  18. Implementation of second moment closure turbulence model for incompressible flows in the industrial finite element code N3S

    International Nuclear Information System (INIS)

    Pot, G.; Laurence, D.; Rharif, N.E.; Leal de Sousa, L.; Compe, C.

    1995-12-01

    This paper deals with the introduction of a second moment closure turbulence model (Reynolds Stress Model) in an industrial finite element code, N3S, developed at Electricite de France.The numerical implementation of the model in N3S will be detailed in 2D and 3D. Some details are given concerning finite element computations and solvers. Then, some results will be given, including a comparison between standard k-ε model, R.S.M. model and experimental data for some test case. (authors). 22 refs., 3 figs

  19. Measuring and modeling the effect of time and temperature on removal torque and sealing force of a continuous thread closure

    Science.gov (United States)

    Pisuchpen, Supachai

    A new technique for measuring the sealing force of a container-closure system was developed by employing a strain gage based transducer. The sealing force is considered a direct indicator for monitoring the mechanical seal integrity of the container-closure systems. A sealing force measuring device and a torque meter were used to investigate the effect of environmental conditions on the relaxation behavior of a 28--400 closure system. The responses from both devices during storage over time were transformed to the percent (%) force retention (FRT) and percent (%) torque retention (TRT) and used to analyze the effect. The high temperature and relative humidity of tropical conditions showed significant effect on the relaxation of the systems studied. It was found that the % TRT over time data were less consistent than the % FRT due to the nature of torque measurement and effect of environmental conditions. The % TRT data were higher than the % FRT indicating less relaxation of torque than of force. Therefore, using the removal torque or % TRT may be misleading in the interpretation of the seal integrity of the container-closure systems. The apparent seal integrity is less when measured by force retention. Mathematical modeling of the relaxation behavior of the systems revealed that the theoretical models derived from spring and dashpot are not applicable. Empirical models using the curve fitting techniques were then applied and excellent agreement with the experimental data was found. The mathematical models developed were extended to long-term prediction for 3 years; the predicted values of the % FRT and % TRT were in the acceptable range for agreement among the models.

  20. Closure system

    International Nuclear Information System (INIS)

    Kube, L.J.

    1978-01-01

    This invention relates generally to gas-cooled nuclear reactor systems and, more particularly, to an improved closure system for a pressure vessel in such a system wherein a penetration is provided for accommodating a heat exchanger. (author)

  1. On the feasibility of the computational modelling of the endoluminal vacuum-assisted closure of an oesophageal anastomotic leakage.

    Science.gov (United States)

    Comellas, Ester; Bellomo, Facundo J; Rosales, Iván; Del Castillo, Luis F; Sánchez, Ricardo; Turon, Pau; Oller, Sergio

    2018-02-01

    Endoluminal vacuum-assisted closure (E-VAC) is a promising therapy to treat anastomotic leakages of the oesophagus and bowel which are associated with high morbidity and mortality rates. An open-pore polyurethane foam is introduced into the leakage cavity and connected to a device that applies a suction pressure to accelerate the closure of the defect. Computational analysis of this healing process can advance our understanding of the biomechanical mechanisms at play. To this aim, we use a dual-stage finite-element analysis in which (i) the structural problem addresses the cavity reduction caused by the suction and (ii) a new constitutive formulation models tissue healing via permanent deformations coupled to a stiffness increase. The numerical implementation in an in-house code is described and a qualitative example illustrates the basic characteristics of the model. The computational model successfully reproduces the generic closure of an anastomotic leakage cavity, supporting the hypothesis that suction pressure promotes healing by means of the aforementioned mechanisms. However, the current framework needs to be enriched with empirical data to help advance device designs and treatment guidelines. Nonetheless, this conceptual study confirms that computational analysis can reproduce E-VAC of anastomotic leakages and establishes the bases for better understanding the mechanobiology of anastomotic defect healing.

  2. Role of pseudo-turbulent stresses in shocked particle clouds and construction of surrogate models for closure

    Science.gov (United States)

    Sen, O.; Gaul, N. J.; Davis, S.; Choi, K. K.; Jacobs, G.; Udaykumar, H. S.

    2018-02-01

    Macroscale models of shock-particle interactions require closure terms for unresolved solid-fluid momentum and energy transfer. These comprise the effects of mean as well as fluctuating fluid-phase velocity fields in the particle cloud. Mean drag and Reynolds stress equivalent terms (also known as pseudo-turbulent terms) appear in the macroscale equations. Closure laws for the pseudo-turbulent terms are constructed in this work from ensembles of high-fidelity mesoscale simulations. The computations are performed over a wide range of Mach numbers (M) and particle volume fractions (φ ) and are used to explicitly compute the pseudo-turbulent stresses from the Favre average of the velocity fluctuations in the flow field. The computed stresses are then used as inputs to a Modified Bayesian Kriging method to generate surrogate models. The surrogates can be used as closure models for the pseudo-turbulent terms in macroscale computations of shock-particle interactions. It is found that the kinetic energy associated with the velocity fluctuations is comparable to that of the mean flow—especially for increasing M and φ . This work is a first attempt to quantify and evaluate the effect of velocity fluctuations for problems of shock-particle interactions.

  3. A small community model for the transmission of infectious diseases: comparison of school closure as an intervention in individual-based models of an influenza pandemic.

    Directory of Open Access Journals (Sweden)

    George J Milne

    Full Text Available BACKGROUND: In the absence of other evidence, modelling has been used extensively to help policy makers plan for a potential future influenza pandemic. METHOD: We have constructed an individual based model of a small community in the developed world with detail down to exact household structure obtained from census collection datasets and precise simulation of household demographics, movement within the community and individual contact patterns. We modelled the spread of pandemic influenza in this community and the effect on daily and final attack rates of four social distancing measures: school closure, increased case isolation, workplace non-attendance and community contact reduction. We compared the modelled results of final attack rates in the absence of any interventions and the effect of school closure as a single intervention with other published individual based models of pandemic influenza in the developed world. RESULTS: We showed that published individual based models estimate similar final attack rates over a range of values for R(0 in a pandemic where no interventions have been implemented; that multiple social distancing measures applied early and continuously can be very effective in interrupting transmission of the pandemic virus for R(0 values up to 2.5; and that different conclusions reached on the simulated benefit of school closure in published models appear to result from differences in assumptions about the timing and duration of school closure and flow-on effects on other social contacts resulting from school closure. CONCLUSION: Models of the spread and control of pandemic influenza have the potential to assist policy makers with decisions about which control strategies to adopt. However, attention needs to be given by policy makers to the assumptions underpinning both the models and the control strategies examined.

  4. Simulated Leaching (Migration) Study for a Model Container-Closure System Applicable to Parenteral and Ophthalmic Drug Products.

    Science.gov (United States)

    Jenke, Dennis; Egert, Thomas; Hendricker, Alan; Castner, James; Feinberg, Tom; Houston, Christopher; Hunt, Desmond G; Lynch, Michael; Nicholas, Kumudini; Norwood, Daniel L; Paskiet, Diane; Ruberto, Michael; Smith, Edward J; Holcomb, Frank; Markovic, Ingrid

    2017-01-01

    A simulating leaching (migration) study was performed on a model container-closure system relevant to parenteral and ophthalmic drug products. This container-closure system consisted of a linear low-density polyethylene bottle (primary container), a polypropylene cap and an elastomeric cap liner (closure), an adhesive label (labeling), and a foil overpouch (secondary container). The bottles were filled with simulating solvents (aqueous salt/acid mixture at pH 2.5, aqueous buffer at pH 9.5, and 1/1 v/v isopropanol/water), a label was affixed to the filled and capped bottles, the filled bottles were placed into the foil overpouch, and the filled and pouched units were stored either upright or inverted for up to 6 months at 40 °C. After storage, the leaching solutions were tested for leached substances using multiple complementary analytical techniques to address volatile, semi-volatile, and non-volatile organic and inorganic extractables as potential leachables.The leaching data generated supported several conclusions, including that (1) the extractables (leachables) profile revealed by a simulating leaching study can qualitatively be correlated with compositional information for materials of construction, (2) the chemical nature of both the extracting medium and the individual extractables (leachables) can markedly affect the resulting profile, and (3) while direct contact between a drug product and a system's material of construction may exacerbate the leaching of substances from that material by the drug product, direct contact is not a prerequisite for migration and leaching to occur. LAY ABSTRACT: The migration of container-related extractables from a model pharmaceutical container-closure system and into simulated drug product solutions was studied, focusing on circumstances relevant to parenteral and ophthalmic drug products. The model system was constructed specifically to address the migration of extractables from labels applied to the outside of the

  5. Large-eddy simulation of stable atmospheric boundary layers to develop better turbulence closures for climate and weather models

    Science.gov (United States)

    Bou-Zeid, Elie; Huang, Jing; Golaz, Jean-Christophe

    2011-11-01

    A disconnect remains between our improved physical understanding of boundary layers stabilized by buoyancy and how we parameterize them in coarse atmospheric models. Most operational climate models require excessive turbulence mixing in such conditions to prevent decoupling of the atmospheric component from the land component, but the performance of such a model is unlikely to be satisfactory under weakly and moderately stable conditions. Using Large-eddy simulation, we revisit some of the basic challenges in parameterizing stable atmospheric boundary layers: eddy-viscosity closure is found to be more reliable due to an improved alignment of vertical Reynolds stresses and mean strains under stable conditions, but the dependence of the magnitude of the eddy viscosity on stability is not well represented by several models tested here. Thus, we propose a new closure that reproduces the different stability regimes better. Subsequently, tests of this model in the GFDL's single-column model (SCM) are found to yield good agreement with LES results in idealized steady-stability cases, as well as in cases with gradual and sharp changes of stability with time.

  6. Direct numerical simulation of natural convection in a vertical channel: a tool for second moment closure modeling

    Energy Technology Data Exchange (ETDEWEB)

    Maupu, V.; Laurence, D. [Electricite de France (EDF), 78 - Chatou (France). Lab. National d`Hydraulique; Boudjemadi, E.; Le Quere, P. [Centre National de la Recherche Scientifique (CNRS), 91 - Orsay (France)

    1996-12-31

    Natural turbulent convection in a differentially heated infinite vertical slot is computed with a mixed finite differences/Fourier code. At a Rayleigh number of 10{sup 5}, in the case without mean stratification, periodic perturbations from the laminar solution develop and transition to a fully turbulent flow occurs. From then on, a database of one-point statistics is presented: mean velocity and temperature, Reynolds stress components, turbulent heat fluxes and variance of temperature, but also budgets of second moment equations. This database is then used for testing of a second moment closure based on the Launder-Reece-Rodi model on an elliptic relaxation for near wall effects on pressure redistribution. This level of modelling is required by the presence of counter gradient fluxes, which cannot be accounted for eddy viscosity and eddy diffusivity assumptions. Furthermore, an algebraic third order moment closure was found necessary because of counter gradient turbulent transport terms which appear to mainly originate from the mean velocity and temperature gradient terms usually neglected in conventional transport models, such as the standard Daly-Harlow or Hanjalic-Launder models. (authors). 18 refs.

  7. Direct numerical simulation of natural convection in a vertical channel: a tool for second moment closure modeling

    International Nuclear Information System (INIS)

    Maupu, V.; Laurence, D.

    1996-01-01

    Natural turbulent convection in a differentially heated infinite vertical slot is computed with a mixed finite differences/Fourier code. At a Rayleigh number of 10 5 , in the case without mean stratification, periodic perturbations from the laminar solution develop and transition to a fully turbulent flow occurs. From then on, a database of one-point statistics is presented: mean velocity and temperature, Reynolds stress components, turbulent heat fluxes and variance of temperature, but also budgets of second moment equations. This database is then used for testing of a second moment closure based on the Launder-Reece-Rodi model on an elliptic relaxation for near wall effects on pressure redistribution. This level of modelling is required by the presence of counter gradient fluxes, which cannot be accounted for eddy viscosity and eddy diffusivity assumptions. Furthermore, an algebraic third order moment closure was found necessary because of counter gradient turbulent transport terms which appear to mainly originate from the mean velocity and temperature gradient terms usually neglected in conventional transport models, such as the standard Daly-Harlow or Hanjalic-Launder models. (authors)

  8. Restaurant closures

    CERN Multimedia

    Novae Restauration

    2012-01-01

    Christmas Restaurant closures Please note that the Restaurant 1 and Restaurant 3 will be closed from Friday, 21 December at 5 p.m. to Sunday, 6 January, inclusive. They will reopen on Monday, 7 January 2013.   Restaurant 2 closure for renovation To meet greater demand and to modernize its infrastructure, Restaurant 2 will be closed from Monday, 17 December. On Monday, 14 January 2013, Sophie Vuetaz’s team will welcome you to a renovated self-service area on the 1st floor. The selections on the ground floor will also be expanded to include pasta and pizza, as well as snacks to eat in or take away. To ensure a continuity of service, we suggest you take your break at Restaurant 1 or Restaurant 3 (Prévessin).

  9. Tight closure and vanishing theorems

    International Nuclear Information System (INIS)

    Smith, K.E.

    2001-01-01

    applications of tight closure include Frobenius characterizations of certain singularities arising in the minimal model program and uniform bounds for global generation of adjoint linear series. Both of these applications are closely tied to vanishing theorems, and indeed, the Kodaira vanishing theorem itself has an equivalent formulation in terms of tight closure

  10. Carpe diem, Carpe ampulla: a numerical model as an aid to the design of child-resistant closures.

    Science.gov (United States)

    Yoxall, A; Rodriguez-Falcon, E M; Luxmoore, J

    2013-01-01

    The population of most developed countries is ageing. Despite continuing medical advances, ageing brings with it a host of issues, not least a loss in strength and dexterity. One major area of concern is the ability of elderly consumers to access packaged goods such as food and medicines. In previous studies, the authors developed a numerical model of a human hand that was used to investigate the effect of physical dimensions and choice of grip on joint stresses to aid the understanding between physical effort, ability and discomfort. This previous work was supported by ethnographic studies and led to recommendations for packaging design. In this paper, a small ethnographic study is undertaken which identifies the grip types used to access to a product that is known to cause particular difficulties for the elderly, the "squeeze and turn" child-resistant closure or CRC, commonly used on medicines and cleaning products. One of the grip types used was chosen to be modelled using the numerical model developed in previous studies by the author. Model geometry and loading were adapted to simulate the "squeeze and turn" nature of the initial opening for closures of this type. A series of studies were then undertaken using different hand geometries; an average male hand, an average female hand and a fifth percentile female hand. The prediction from the model here is that female users with smaller hands will experience more discomfort when accessing squeeze and turn CRC's and that the turn process whilst maintaining the squeeze is problematic. Copyright © 2012 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  11. Design of closure works

    NARCIS (Netherlands)

    Van Duivedijk, H.; Verhagen, H.J.

    2007-01-01

    This chapter discusses the design aspects of estuary and river closures and those of reservoir dams and certain other hydraulic structures. The focus of this chapter is on closures, not on the situation after the closure has been completed.

  12. Reference interaction site model investigation of homonuclear hard dumbbells under simple fluid theory closures: comparison with Monte Carlo simulations.

    Science.gov (United States)

    Munaò, G; Costa, D; Caccamo, C

    2009-04-14

    We revisit the thermodynamic and structural properties of fluids of homonuclear hard dumbbells in the framework provided by the reference interaction site model (RISM) theory of molecular fluids. Besides the previously investigated Percus-Yevick (PY) approximation, we test the accuracy of other closures to the RISM equations, imported from the theory of simple fluids; specifically, we study the hypernetted chain (HNC), the modified HNC (MHNC) and, less extensively, the Verlet approximations. We implement our approach for models characterized by several different elongations, up to the case of tangent diatomics, and investigate the whole fluid density range. The theoretical predictions are assessed against Monte Carlo simulations, either available from literature or newly generated by us. The HNC and PY equations of state, calculated via different routes, share on the whole the same level of accuracy. The MHNC is applied by enforcing an internal thermodynamic consistency constraint, leading to good predictions for the equation of state as the elongation of the dumbbell increases. As for the radial distribution function, the MHNC appears superior to other theories, especially for tangent diatomics in the high density limit; the PY approximation is better than the HNC and Verlet closures in the high density or elongation regime. Our structural analysis is supplemented by an accurate inversion procedure to reconstruct from Monte Carlo data and RISM the "exact" direct correlation function. In agreement with such calculations and consistent with the forecast of rigorous diagrammatic analysis, all theories predict the occurrence in the direct correlation function of a first cusp inside the dumbbell core and (with the obvious exception of the PY) of a second cusp outside; the cusps' heights are also qualitatively well reproduced by the theories, except at high densities.

  13. The impact of rural hospital closures on equity of commuting time for haemodialysis patients: simulation analysis using the capacity-distance model

    Directory of Open Access Journals (Sweden)

    Matsumoto Masatoshi

    2012-07-01

    Full Text Available Abstract Background Frequent and long-term commuting is a requirement for dialysis patients. Accessibility thus affects their quality of lives. In this paper, a new model for accessibility measurement is proposed in which both geographic distance and facility capacity are taken into account. Simulation of closure of rural facilities and that of capacity transfer between urban and rural facilities are conducted to evaluate the impacts of these phenomena on equity of accessibility among dialysis patients. Methods Post code information as of August 2011 of all the 7,374 patients certified by municipalities of Hiroshima prefecture as having first or third grade renal disability were collected. Information on post code and the maximum number of outpatients (capacity of all the 98 dialysis facilities were also collected. Using geographic information systems, patient commuting times were calculated in two models: one that takes into account road distance (distance model, and the other that takes into account both the road distance and facility capacity (capacity-distance model. Simulations of closures of rural and urban facilities were then conducted. Results The median commuting time among rural patients was more than twice as long as that among urban patients (15 versus 7 minutes, p  Conclusions Closures of dialysis facilities in rural areas have a substantially larger impact on equity of commuting times among dialysis patients than closures of urban facilities. The accessibility simulations using thecapacity-distance model will provide an analytic framework upon which rational resource distribution policies might be planned.

  14. RELAP-7 Closure Correlations

    Energy Technology Data Exchange (ETDEWEB)

    Zou, Ling [Idaho National Lab. (INL), Idaho Falls, ID (United States); Berry, R. A. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Martineau, R. C. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Andrs, D. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Zhang, H. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Hansel, J. E. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Sharpe, J. P. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Johns, Russell C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-04-01

    The RELAP-7 code is the next generation nuclear reactor system safety analysis code being developed at the Idaho National Laboratory (INL). The code is based on the INL’s modern scientific software development framework, MOOSE (Multi-Physics Object Oriented Simulation Environment). The overall design goal of RELAP-7 is to take advantage of the previous thirty years of advancements in computer architecture, software design, numerical integration methods, and physical models. The end result will be a reactor systems analysis capability that retains and improves upon RELAP5’s and TRACE’s capabilities and extends their analysis capabilities for all reactor system simulation scenarios. The RELAP-7 code utilizes the well-posed 7-equation two-phase flow model for compressible two-phase flow. Closure models used in the TRACE code has been reviewed and selected to reflect the progress made during the past decades and provide a basis for the colure correlations implemented in the RELAP-7 code. This document provides a summary on the closure correlations that are currently implemented in the RELAP-7 code. The closure correlations include sub-grid models that describe interactions between the fluids and the flow channel, and interactions between the two phases.

  15. New device for closure of muscular ventricular septal defects in a canine model.

    Science.gov (United States)

    Amin, Z; Gu, X; Berry, J M; Bass, J L; Titus, J L; Urness, M; Han, Y M; Amplatz, K

    1999-07-20

    Repair of muscular ventricular septal defects (MVSDs) has always been challenging to the surgeon. Long-term morbidity and mortality are significantly increased if the defects are closed via left ventriculotomy or if they are associated with other complex congenital anomalies. The purpose of this study was to close MVSDs with the Amplatz ventricular septal defect device. This device is constructed from 0.004-in nitinol wire mesh filled with polyester fibers. It is retrievable, repositionable, self-centering, and of low profile. MVSDs were created with the help of a sharp punch in 10 dogs. The location of the defects was anterior muscular (n=3), midmuscular (n=3), apical (n=3), and inlet muscular (n=1). The diameter of the defects ranged from 6 to 14 mm. All defects were closed in the catheterization laboratory. The device was placed with the help of transesophageal echocardiography and fluoroscopy. A 7F sheath was used to deploy the device from the right ventricular side in 8 and the left ventricular side in 2 dogs. Placement was successful in all animals. The complete closure rate was 30% (3/10) immediately after placement and 100% at 1-week follow-up. Pathological examination of the heart revealed complete endothelialization of the device in dogs killed after 3 months. The Amplatz ventricular septal defect device appears highly efficacious in closing MVSDs. The advantages include a small delivery sheath, complete retrievability before release, and the fact that it is self-centering and self-expanding, thereby making it an attractive option in smaller children.

  16. Enhancing Understanding of Magnetized High Energy Density Plasmas from Solid Liner Implosions Using Fluid Modeling with Kinetic Closures

    Science.gov (United States)

    Masti, Robert; Srinivasan, Bhuvana; King, Jacob; Stoltz, Peter; Hansen, David; Held, Eric

    2017-10-01

    Recent results from experiments and simulations of magnetically driven pulsed power liners have explored the role of early-time electrothermal instability in the evolution of the MRT (magneto-Rayleigh-Taylor) instability. Understanding the development of these instabilities can lead to potential stabilization mechanisms; thereby providing a significant role in the success of fusion concepts such as MagLIF (Magnetized Liner Inertial Fusion). For MagLIF the MRT instability is the most detrimental instability toward achieving fusion energy production. Experiments of high-energy density plasmas from wire-array implosions have shown the requirement for more advanced physics modeling than that of ideal magnetohydrodynamics. The overall focus of this project is on using a multi-fluid extended-MHD model with kinetic closures for thermal conductivity, resistivity, and viscosity. The extended-MHD model has been updated to include the SESAME equation-of-state tables and numerical benchmarks with this implementation will be presented. Simulations of MRT growth and evolution for MagLIF-relevant parameters will be presented using this extended-MHD model with the SESAME equation-of-state tables. This work is supported by the Department of Energy Office of Science under Grant Number DE-SC0016515.

  17. Comparison of Hydrological Cycle and Sensitivity Between Multiscale Modeling Frameworks with and without a Higher-order Turbulence Closure

    Science.gov (United States)

    Xu, Kuan-Man; Li, Zhujun

    2017-04-01

    Current conventional global climate models (GCMs) produce a weak increase in global mean precipitation with anthropogenic warming in comparison with the lower-tropospheric moisture increases. The motive of this study is to understand the relatively small differences in the hydrological sensitivity between two multiscale modeling frameworks (MMFs) that arise from the different treatments of turbulence in order to aid to the understanding of the large model spread among conventional GCMs. We compare the hydrological sensitivity and its energetic constraint from MMFs with (SPCAM-IPHOC) or without (SPCAM) an advanced higher-order turbulence closure. SPCAM-IPHOC simulates higher global hydrological sensitivity (3.7%/K) than SPCAM (3.0%/K) and GCMs (2.52±0.22%/K). This is mostly related to the higher sensitivity of surface sensible and latent heat fluxes and radiative cooling to surface warming and a higher ratio of latent heating to radiative cooling. The two MMFs differ greatly in the hydrological sensitivity over the tropical lands, where the simulated sensitivity of surface sensible heat fluxes to surface warming and CO2 increase in SPCAM-IPHOC is weaker than in SPCAM. Furthermore, the different divergences of dry static energy flux simulated by the two MMFs contribute to the difference in regional precipitation sensitivity between the two models. Implications of these results to conventional GCMs will be discussed at the meeting.

  18. Extending the bounds of ‘steady’ RANS closures: Toward an instability-sensitive Reynolds stress model

    International Nuclear Information System (INIS)

    Jakirlić, S.; Maduta, R.

    2015-01-01

    Highlights: • A grid-spacing free, instability-sensitive Reynolds stress model is formulated. • The model is capable of capturing turbulence fluctuations. • Substantial improvement concerning proper turbulence activity enhancement is achieved. • The model is intensively validated in a series of 2D and 3D separating flows. • The model feasibility is also checked in some attached flows. - Abstract: The incapability of the conventional Unsteady RANS (Reynolds–Averaged Navier Stokes) models to adequately capture turbulence unsteadiness presents the prime motivation of the present work, which focuses on formulating an instability-sensitive, eddy-resolving turbulence model on the Second-Moment Closure level. The model scheme adopted, functioning as a ‘sub-scale’ model in the Unsteady RANS framework, represents a differential near-wall Reynolds stress model formulated in conjunction with the scale-supplying equation governing the homogeneous part of the inverse turbulent time scale ω h (ω h = ε h /k). The latter equation was straightforwardly obtained from the model equation describing the dynamics of the homogeneous part of the total viscous dissipation rate ε, defined as ε h = ε − 0.5ν∂ 2 k/(∂x j ∂x j ) (Jakirlic and Hanjalic, 2002), by applying the derivation rules to the expression for ω h . The model capability to account for vortex length and time scales variability was enabled through an additional term in the corresponding length-scale determining equation, providing a selective enhancement of its production, pertinent particularly to the highly unsteady separated shear layer region, modeled in terms of the von Karman length scale (comprising the second derivative of the velocity field) in line with the SAS (Scale-Adaptive Simulation) proposal (Menter and Egorov, 2010). The present model formulation, termed as SRANS model (Sensitized RANS), does not comprise any parameter depending explicitly on grid spacing. The predictive

  19. Evaluating the Performance of the Mixture Model Coupled with High and Low Reynolds Turbulence Closures in the Numerical Description of Concentrated Solid-Liquid Flows of Settling Particles

    Directory of Open Access Journals (Sweden)

    R. Silva

    2015-12-01

    Full Text Available In this manuscript, Computational Fluid Dynamics (CFD studies applying the Mixture Model coupled with both a High Reynolds and a Low Reynolds k-ε turbulence closures, were used to describe experimental pressure gradients and particle concentration profiles from the literature, for concentrated solid-liquid flows of settling particles in a horizontal pipe above the critical deposition velocity. With this work a new Mixture Model formulation is presented, incorporating the Jones-Launder Low Reynolds k-ε turbulence closure, to overcome the excessive turbulence production observed in the numerical studies using the High Reynolds k-ε turbulence model. Additionally, this formulation provides a more accurate representation of the wall turbulence damping phenomena, observed in the experimental testing for the flow of higher particle concentrations suspensions and higher flow velocities. Knowledge on the conditions that cause turbulence attenuation on solid-liquid flows is still scarce in the literature and of considerable value for industrial applications.

  20. Differences in the hydrological cycle and sensitivity between multiscale modeling frameworks with and without a higher-order turbulence closure

    Science.gov (United States)

    Xu, Kuan-Man; Li, Zhujun; Cheng, Anning; Blossey, Peter N.; Stan, Cristiana

    2017-09-01

    Current conventional global climate models (GCMs) produce a weak increase in global-mean precipitation with anthropogenic warming in comparison with the lower tropospheric moisture increases. The motive of this study is to understand the differences in the hydrological sensitivity between two multiscale modeling frameworks (MMFs) that arise from the different treatments of turbulence and low clouds in order to aid to the understanding of the model spread among conventional GCMs. We compare the hydrological sensitivity and its energetic constraint from MMFs with (SPCAM-IPHOC) or without (SPCAM) an advanced higher-order turbulence closure. SPCAM-IPHOC simulates higher global hydrological sensitivity for the slow response but lower sensitivity for the fast response than SPCAM. Their differences are comparable to the spreads of conventional GCMs. The higher sensitivity in SPCAM-IPHOC is associated with the higher ratio of the changes in latent heating to those in net atmospheric radiative cooling, which is further related to a stronger decrease in the Bowen ratio with warming than in SPCAM. The higher sensitivity of cloud radiative cooling resulting from the lack of low clouds in SPCAM is another major factor in contributing to the lower precipitation sensitivity. The two MMFs differ greatly in the hydrological sensitivity over the tropical lands, where the simulated sensitivity of surface sensible heat fluxes to surface warming and CO2 increase in SPCAM-IPHOC is weaker than in SPCAM. The difference in divergences of dry static energy flux simulated by the two MMFs also contributes to the difference in land precipitation sensitivity between the two models.

  1. Predictions for heat transfer characteristics in a natural draft reactor cooling system using a second moment closure turbulence model

    International Nuclear Information System (INIS)

    Nishimura, M.; Maekawa, I.

    2004-01-01

    A numerical study is performed on the natural draft reactor cavity cooling system (RCCS). In the cooling system, buoyancy driven heated upward flow could be in the mixed convection regime that is accompanied by heat transfer impairment. Also, the heating wall condition is asymmetric with regard to the channel cross section. These flow regime and thermal boundary conditions may invalidate the use of design correlation. To precisely simulate the flow and thermal fields within the RCCS, the second moment closure turbulence model is applied. Two types of the RCCS channel geometry are selected to make a comparison: an annular duct with fins on the outer surface of the inner circular wall, and a multi-rectangular duct. The prediction shows that the local heat transfer coefficient on the RCCS with finned annular duct is less than 1/6 of that estimated with Dittus-Boelter correlation. Much portion of the natural draft airflow does not contribute cooling at all because mainstream escapes from the narrow gaps between the fins. This result and thus the finned annulus design are unacceptable from the viewpoint for structural integrity of the RCCS wall boundary. The performance of the multi-rectangular duct design is acceptable that the RCCS maximum temperature is less than 400 degree centigrade even when the flow rate is halved from the designed condition. (author)

  2. Post-closure biosphere assessment modelling: comparison of complex and more stylised approaches.

    Science.gov (United States)

    Walke, Russell C; Kirchner, Gerald; Xu, Shulan; Dverstorp, Björn

    2015-10-01

    Geological disposal facilities are the preferred option for high-level radioactive waste, due to their potential to provide isolation from the surface environment (biosphere) on very long timescales. Assessments need to strike a balance between stylised models and more complex approaches that draw more extensively on site-specific information. This paper explores the relative merits of complex versus more stylised biosphere models in the context of a site-specific assessment. The more complex biosphere modelling approach was developed by the Swedish Nuclear Fuel and Waste Management Co (SKB) for the Formark candidate site for a spent nuclear fuel repository in Sweden. SKB's approach is built on a landscape development model, whereby radionuclide releases to distinct hydrological basins/sub-catchments (termed 'objects') are represented as they evolve through land rise and climate change. Each of seventeen of these objects is represented with more than 80 site specific parameters, with about 22 that are time-dependent and result in over 5000 input values per object. The more stylised biosphere models developed for this study represent releases to individual ecosystems without environmental change and include the most plausible transport processes. In the context of regulatory review of the landscape modelling approach adopted in the SR-Site assessment in Sweden, the more stylised representation has helped to build understanding in the more complex modelling approaches by providing bounding results, checking the reasonableness of the more complex modelling, highlighting uncertainties introduced through conceptual assumptions and helping to quantify the conservatisms involved. The more stylised biosphere models are also shown capable of reproducing the results of more complex approaches. A major recommendation is that biosphere assessments need to justify the degree of complexity in modelling approaches as well as simplifying and conservative assumptions. In light of

  3. A Fibrocontractive Mechanochemical Model of Dermal Wound Closure Incorporating Realistic Growth Factor Kinetics

    KAUST Repository

    Murphy, Kelly E.

    2012-01-13

    Fibroblasts and their activated phenotype, myofibroblasts, are the primary cell types involved in the contraction associated with dermal wound healing. Recent experimental evidence indicates that the transformation from fibroblasts to myofibroblasts involves two distinct processes: The cells are stimulated to change phenotype by the combined actions of transforming growth factor β (TGFβ) and mechanical tension. This observation indicates a need for a detailed exploration of the effect of the strong interactions between the mechanical changes and growth factors in dermal wound healing. We review the experimental findings in detail and develop a model of dermal wound healing that incorporates these phenomena. Our model includes the interactions between TGFβ and collagenase, providing a more biologically realistic form for the growth factor kinetics than those included in previous mechanochemical descriptions. A comparison is made between the model predictions and experimental data on human dermal wound healing and all the essential features are well matched. © 2012 Society for Mathematical Biology.

  4. On the use of the post-closure methods uncertainty band to evaluate the performance of land surface models against eddy covariance flux data

    Science.gov (United States)

    Ingwersen, Joachim; Imukova, Kristina; Högy, Petra; Streck, Thilo

    2017-04-01

    The energy balance of eddy covariance (EC) flux data is normally not closed. Therefore, at least if used for modeling, EC flux data are usually post-closed, i.e. the measured turbulent fluxes are adjusted so as to close the energy balance. At the current state of knowledge, however, it is not clear how to partition the missing energy in the right way. Eddy flux data therefore contain some uncertainty due to the unknown nature of the energy balance gap, which should be considered in model evaluation and the interpretation of simulation results. We propose to construct the post-closure method uncertainty band (PUB), which essentially designates the differences between non-adjusted flux data and flux data adjusted with the three post-closure methods (Bowen ratio, latent heat flux (LE) and sensible heat flux (H) method). To demonstrate this approach, simulations with the NOAH-MP land surface model were evaluated based on EC measurements conducted at a winter wheat stand in Southwest Germany in 2011, and the performance of the Jarvis and Ball-Berry stomatal resistance scheme was compared. The width of the PUB of the LE was up to 110 W/m2 (21% of net radiation). Our study shows that it is crucial to account for the uncertainty of EC flux data originating from lacking energy balance closure. Working with only a single post-closing method might result in severe misinterpretations in model-data comparisons.

  5. A New Coated Nitinol Occluder for Transcatheter Closure of Ventricular Septal Defects in a Canine Model

    Directory of Open Access Journals (Sweden)

    Yong Zhou

    2013-01-01

    Full Text Available Aims. This study evaluated feasibility and safety of implanting the polyester-coated nitinol ventricular septal defect occluder (pcVSDO in the canine model. Methods and Results. VSD models were successfully established by transseptal ventricular septal puncture via the right jugular vein in 15 out of 18 canines. Two types of VSDOs were implanted, either with pcVSDOs (n=8 as the new type occluder group or with the commercial ventricular septal defect occluders (VSDOs, n=7, Shanghai Sharp Memory Alloy Co. Ltd. as the control group. Sheath size was 10 French (10 Fr in two groups. Then the general state of the canines was observed after implantation. ECG and TTE were performed, respectively, at 7, 30, 90 days of follow-up. The canines were sacrificed at these time points for pathological and scanning electron microscopy examination. The devices were successfully implanted in all 15 canines and were retrievable and repositionable. There was no thrombus formation on the device or occurrence of complete heart block. The pcVSDO surface implanted at day 7 was already covered with neotissue by gross examination, and it completed endothelialization at day 30, while the commercial VSDO was covered with the neotissue in 30th day and the complete endothelialization in 90th day. Conclusion. The study shows that pcVSDO is feasible and safe to close canine VSD model and has good biocompatibility and shorter time of endothelialization.

  6. Full closure strategic analysis.

    Science.gov (United States)

    2014-07-01

    The full closure strategic analysis was conducted to create a decision process whereby full roadway : closures for construction and maintenance activities can be evaluated and approved or denied by CDOT : Traffic personnel. The study reviewed current...

  7. Sternal exploration or closure

    Science.gov (United States)

    VAC - vacuum-assisted closure - sternal wound; Sternal dehiscence; Sternal infection ... in the wound to look for signs of infection Remove dead or infected ... use a VAC (vacuum-assisted closure) dressing. It is a negative ...

  8. 40 CFR 265.113 - Closure; time allowed for closure.

    Science.gov (United States)

    2010-07-01

    ... DISPOSAL FACILITIES Closure and Post-Closure § 265.113 Closure; time allowed for closure. (a) Within 90... assessment required under RCRA section 3019, and closure and post-closure plans, and updated cost estimates... sludges to the extent practicable without impairing the integrity of the liner(s), if any. (3) Removal of...

  9. Rehabilitation Closure Criteria Assessment Using High Resolution Photogrammetrically Derived Surface Models

    Science.gov (United States)

    Fletcher, A. T.; Erskine, P. D.

    2013-08-01

    Relinquishment of mined land is unlikely to occur without compelling evidence that post mine landforms have a sustainable vegetation cover and represent a minimal liability to subsequent land users. Gully and rill erosion result in unstable landforms create unsafe landscapes for commonly targeted post mine land uses, such as grazing. The photogrammetric products of two small Unmanned Aerial Vehicle (UAV) platforms were compared as a means of delineating erosion gullies and comparing vegetation in rehabilitation at an open cut coal mine in the Bowen Basin, Queensland. Erosion gullies were clearly visible in both UAV products at 5 cm resolution; however, target illumination and photogrammetric processing methods largely determined the ability to identify erosion from surface models. Individual tree canopies were clearly visible in both products, as were phenological traits such as leaf flushing and flowering. The high spatial resolution resulted in unreliable detection of tree crowns in both processing methods.

  10. REHABILITATION CLOSURE CRITERIA ASSESSMENT USING HIGH RESOLUTION PHOTOGRAMMETRICALLY DERIVED SURFACE MODELS

    Directory of Open Access Journals (Sweden)

    A. T. Fletcher

    2013-08-01

    Full Text Available Relinquishment of mined land is unlikely to occur without compelling evidence that post mine landforms have a sustainable vegetation cover and represent a minimal liability to subsequent land users. Gully and rill erosion result in unstable landforms create unsafe landscapes for commonly targeted post mine land uses, such as grazing. The photogrammetric products of two small Unmanned Aerial Vehicle (UAV platforms were compared as a means of delineating erosion gullies and comparing vegetation in rehabilitation at an open cut coal mine in the Bowen Basin, Queensland. Erosion gullies were clearly visible in both UAV products at 5 cm resolution; however, target illumination and photogrammetric processing methods largely determined the ability to identify erosion from surface models. Individual tree canopies were clearly visible in both products, as were phenological traits such as leaf flushing and flowering. The high spatial resolution resulted in unreliable detection of tree crowns in both processing methods.

  11. [Retrieval of crown closure of moso bamboo forest using unmanned aerial vehicle (UAV) remotely sensed imagery based on geometric-optical model].

    Science.gov (United States)

    Wang, Cong; Du, Hua-qiang; Zhou, Guo-mo; Xu, Xiao-jun; Sun, Shao-bo; Gao, Guo-long

    2015-05-01

    This research focused on the application of remotely sensed imagery from unmanned aerial vehicle (UAV) with high spatial resolution for the estimation of crown closure of moso bamboo forest based on the geometric-optical model, and analyzed the influence of unconstrained and fully constrained linear spectral mixture analysis (SMA) on the accuracy of the estimated results. The results demonstrated that the combination of UAV remotely sensed imagery and geometric-optical model could, to some degrees, achieve the estimation of crown closure. However, the different SMA methods led to significant differentiation in the estimation accuracy. Compared with unconstrained SMA, the fully constrained linear SMA method resulted in higher accuracy of the estimated values, with the coefficient of determination (R2) of 0.63 at 0.01 level, against the measured values acquired during the field survey. Root mean square error (RMSE) of approximate 0.04 was low, indicating that the usage of fully constrained linear SMA could bring about better results in crown closure estimation, which was closer to the actual condition in moso bamboo forest.

  12. Printshop closure

    CERN Multimedia

    2012-01-01

    Please note that the CERN Printshop will be closed to replace the printers with new models and enhance the functions from: Monday 17 December 2012 until at least Friday 11 January 2013. Please take this into consideration for your forthcoming printing needs and check our website for any updates. Thank you in advance for your understanding.

  13. Closure The Definitive Guide

    CERN Document Server

    Bolin, Michael

    2010-01-01

    If you're ready to use Closure to build rich web applications with JavaScript, this hands-on guide has precisely what you need to learn this suite of tools in depth. Closure makes it easy for experienced JavaScript developers to write and maintain large and complex codebases -- as Google has demonstrated by using Closure with Gmail, Google Docs, and Google Maps. Author and Closure contributor Michael Bolin has included numerous code examples and best practices, as well as valuable information not available publicly until now. You'll learn all about Closure's Library, Compiler, Templates, tes

  14. Off-pump atrial septal defect closure using the universal cardiac introducer®: creation of models of atrial septal defects in the pig access and surgical technique.

    Science.gov (United States)

    Guiraudon, Gerard M; Jones, Douglas L; Bainbridge, Daniel; Moore, John T; Wedlake, Chris; Linte, Cristian; Wiles, Andrew; Peters, Terry M

    2009-01-01

    : Optimal atrial septal defect (ASD) closure should combine off-pump techniques with the effectiveness and versatility of open-heart techniques. We report our experience with off-pump ASD closure using the Universal Cardiac Introducer (UCI) in a porcine model. The goal was to create an ASD over the fossa ovale (FO) and position a patch over the ASD under ultrasound (US) imaging and augmented virtual reality guidance. : An US probe (tracked with a magnetic tracking system) was positioned into the esophagus (transesophageal echocardiographic probe) for real-time image-guidance. The right atrium (RA) of six pigs was exposed via a right lateral thoracotomy or medial sternotomy. The UCI was attached to the RA wall. A punching tool was introduced via the UCI, navigated and positioned, under US guidance, to create an ASD into the FO. A patch with its holder and a stapling device were introduced into the RA via the UCI. The patch was positioned on the ASD. Occlusion of the ASD was determined using US and Doppler imaging. : The FO membrane was excised successfully in all animals. US image-guidance provided excellent visualization. The patch was positioned in all cases with complete occlusion of the ASD. The stapling device proved too bulky, impeding circumferential positioning. : Using the UCI, ASD closure was safe and feasible. US imaging, combined with virtual and augmented reality provided accurate navigating and positioning. This study also provided valuable information on the future design of anchoring devices for intracardiac procedures.

  15. Validation of CTF Droplet Entrainment and Annular/Mist Closure Models using Riso Steam/Water Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Wysocki, Aaron J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Salko, Robert K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-02-01

    This report summarizes the work done to validate the droplet entrainment and de-entrainment models as well as two-phase closure models in the CTF code by comparison with experimental data obtained at Riso National Laboratory. The Riso data included a series of over 250 steam/water experiments that were performed in both tube and annulus geometries over a range of various pressures and outlet qualities. Experimental conditions were set so that the majority of cases were in the annular/mist ow regime. Measurements included liquid lm ow rate, droplet ow rate, lm thickness, and two-phase pressure drop. CTF was used to model 180 of the tubular geometry cases, matching experimental geometry, outlet pressure, and outlet ow quality to experimental values. CTF results were compared to the experimental data at the outlet of the test section in terms of vapor and entrained liquid ow fractions, pressure drop per unit length, and liquid lm thickness. The entire process of generating CTF input decks, running cases, extracting data, and generating comparison plots was scripted using Python and Matplotlib for a completely automated validation process. All test cases and scripting tools have been committed to the COBRA-TF master repository and selected cases have been added to the continuous testing system to serve as regression tests. The dierences between the CTF- and experimentally-calculated ow fraction values were con- sistent with previous calculations by Wurtz, who applied the same entrainment correlation to the same data. It has been found that CTF's entrainment/de-entrainment predictive capability in the annular/mist ow regime for this particular facility is comparable to the licensed industry code, COBRAG. While lm and droplet predictions are generally good, it has been found that accuracy is diminished at lower ow qualities. This nding is consistent with the noted deciencies in the Wurtz entrainment model employed by CTF. The CTF predicted two-phase pressure drop in

  16. Reflood completion report: Volume 1. A phenomenological thermal-hydraulic model of hot rod bundles experiencing simultaneous bottom and top quenching and an optimization methodology for closure development

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, R.A. Jr.; Pimentel, D.A.; Jolly-Woodruff, S.; Spore, J.

    1998-04-01

    In this report, a phenomenological model of simultaneous bottom-up and top-down quenching is developed and discussed. The model was implemented in the TRAC-PF1/MOD2 computer code. Two sets of closure relationships were compared within the study, the Absolute set and the Conditional set. The Absolute set of correlations is frequently viewed as the pure set because the correlations is frequently viewed as the pure set because the correlations utilize their original coefficients as suggested by the developer. The Conditional set is a modified set of correlations with changes to the correlation coefficient only. Results for these two sets indicate quite similar results. This report also summarizes initial results of an effort to investigate nonlinear optimization techniques applied to the closure model development. Results suggest that such techniques can provide advantages for future model development work, but that extensive expertise is required to utilize such techniques (i.e., the model developer must fully understand both the physics of the process being represented and the computational techniques being employed). The computer may then be used to improve the correlation of computational results with experiments.

  17. Combining data sets of satellite-retrieved products for basin-scale water balance study: 2. Evaluation on the Mississippi Basin and closure correction model

    Science.gov (United States)

    Munier, Simon; Aires, Filipe; Schlaffer, Stefan; Prigent, Catherine; Papa, Fabrice; Maisongrande, Philippe; Pan, Ming

    2014-11-01

    In this study, we applied the integration methodology developed in the companion paper by Aires (2014) by using real satellite observations over the Mississippi Basin. The methodology provides basin-scale estimates of the four water budget components (precipitation P, evapotranspiration E, water storage change ΔS, and runoff R) in a two-step process: the Simple Weighting (SW) integration and a Postprocessing Filtering (PF) that imposes the water budget closure. A comparison with in situ observations of P and E demonstrated that PF improved the estimation of both components. A Closure Correction Model (CCM) has been derived from the integrated product (SW+PF) that allows to correct each observation data set independently, unlike the SW+PF method which requires simultaneous estimates of the four components. The CCM allows to standardize the various data sets for each component and highly decrease the budget residual (P - E - ΔS - R). As a direct application, the CCM was combined with the water budget equation to reconstruct missing values in any component. Results of a Monte Carlo experiment with synthetic gaps demonstrated the good performances of the method, except for the runoff data that has a variability of the same order of magnitude as the budget residual. Similarly, we proposed a reconstruction of ΔS between 1990 and 2002 where no Gravity Recovery and Climate Experiment data are available. Unlike most of the studies dealing with the water budget closure at the basin scale, only satellite observations and in situ runoff measurements are used. Consequently, the integrated data sets are model independent and can be used for model calibration or validation.

  18. MNC Subsidiary Closures

    DEFF Research Database (Denmark)

    Sofka, Wolfgang; Torres Preto, Miguel; de Faria, Pedro

    2014-01-01

    displacement model for foreign MNC subsidiaries that integrates insights from the labor economics and international business literatures. We argue that a new employer will pay higher wages when signals indicate that potential employees have valuable, foreign human capital (e.g., the closed subsidiary......We investigate the consequences of MNC subsidiary closures for employees who lose their jobs. In particular, we examine the extent to which the human capital that these employees acquired while employed by the MNC influences the wages they receive in their new jobs. We propose an employee...... was highly productive by host-country standards), and lower wages when signals indicate that potential employees have highly MNC-specific human capital (e.g., the employee had a long tenure in the closed subsidiary). We provide empirical evidence based on a sample of 110,133 displaced employees of closed MNC...

  19. Revisiting the Landau fluid closure.

    Science.gov (United States)

    Hunana, P.; Zank, G. P.; Webb, G. M.; Adhikari, L.

    2017-12-01

    Advanced fluid models that are much closer to the full kinetic description than the usual magnetohydrodynamic description are a very useful tool for studying astrophysical plasmas and for interpreting solar wind observational data. The development of advanced fluid models that contain certain kinetic effects is complicated and has attracted much attention over the past years. Here we focus on fluid models that incorporate the simplest possible forms of Landau damping, derived from linear kinetic theory expanded about a leading-order (gyrotropic) bi-Maxwellian distribution function f_0, under the approximation that the perturbed distribution function f_1 is gyrotropic as well. Specifically, we focus on various Pade approximants to the usual plasma response function (and to the plasma dispersion function) and examine possibilities that lead to a closure of the linear kinetic hierarchy of fluid moments. We present re-examination of the simplest Landau fluid closures.

  20. Borehole closure in salt

    International Nuclear Information System (INIS)

    Fuenkajorn, K.; Daemen, J.J.K.

    1988-12-01

    Constitutive law parameters are determined from salt behavior characterization experiments. The results are applied to predict creep (time-dependent) closure of boreholes in salt specimens subjected to various loading configurations. Rheological models (linear and nonlinear viscoelastic and viscoplastic models), empirical models, and physical theory models have been formulated from the results of uniaxial creep tests, strain and stress rate controlled uniaxial tests, constant strain rate triaxial tests, cyclic loading tests, and seismic velocity measurements. Analytical solutions for a thick-walled cylinder subjected to internal and external pressures and for a circular hole in an infinite plate subjected to a biaxial or uniaxial stressfield have been derived from each of the linear viscoelastic models and from one of the empirical laws. The experimental results indicate that the salt samples behave as an elastic-viscoplastic material. The elastic behavior tends to be linear and time-independent. The plastic deformation is time-dependent. The stress increment to strain rate increment ratio gradually decreases as the stress level increases. The transient potential creep law seems to give the simplest satisfactory governing equation describing the viscoplastic behavior of salt during the transient phase. 204 refs., 27 figs., 29 tabs

  1. Eyelid closure at death

    Directory of Open Access Journals (Sweden)

    A D Macleod

    2009-01-01

    Full Text Available Aim: To observe the incidence of full or partial eyelid closure at death. Materials and Methods: The presence of ptosis was recorded in 100 consecutive hospice patient deaths. Results: Majority (63% of the patients died with their eyes fully closed, however, 37% had bilateral ptosis at death, with incomplete eye closure. In this study, central nervous system tumor involvement and/or acute hepatic encephalopathy appeared to be pre-mortem risk factors of bilateral ptosis at death. Conclusion: Organicity and not psychogenicity is, therefore, the likely etiology of failure of full eyelid closure at death.

  2. Impact of the controlled release of a connexin 43 peptide on corneal wound closure in an STZ model of type I diabetes.

    Directory of Open Access Journals (Sweden)

    Keith Moore

    Full Text Available The alpha-carboxy terminus 1 (αCT1 peptide is a synthetically produced mimetic modified from the DDLEI C-terminus sequence of connexin 43 (Cx43. Previous research using various wound healing models have found promising therapeutic effects when applying the drug, resulting in increased wound healing rates and reduced scarring. Previous data suggested a rapid metabolism rate in vitro, creating an interest in long term release. Using a streptozotocin (STZ type I diabetic rat model with a surgically induced corneal injury, we delivered αCT1 both directly, in a pluronic gel solution, and in a sustained system, using polymeric alginate-poly-l-ornithine (A-PLO microcapsules (MC. Fluorescent staining of wound area over a 5 day period indicated a significant increase in wound closure rates for both αCT1 and αCT1 MC treated groups, withαCT1 MC groups showing the most rapid wound closure overall. Analysis of inflammatory reaction to the treatment groups indicated significantly lower levels of both Interferon Inducible T-Cell Alpha Chemoattractant (ITAC and Tumor Necrosis Factor Alpha (TNFα markers using confocal quantification and ELISA assays. Additional analysis examining genes selected from the EMT pathway using RT-PCR and Western blotting suggested αCT1 modification of Transforming Growth Factor Beta 2 (TGFβ2, Keratin 8 (Krt8, Estrogen Receptor 1 (Esr1, and Glucose Transporter 4 (Glut4 over a 14 day period. Combined, this data indicated a possible suppression of the inflammatory response by αCT1, leading to increased wound healing rates.

  3. Intestinal epithelial restitution. Involvement of specific laminin isoforms and integrin laminin receptors in wound closure of a transformed model epithelium

    DEFF Research Database (Denmark)

    Lotz, M M; Nusrat, A; Madara, J L

    1997-01-01

    laminins 5, 6, and 7 as indicated by immunostaining using laminin subunit-specific monoclonal antibodies (MAbs). A MAb (BM2) specific for the laminin alpha 3 subunit, a component of laminins 5, 6, and 7, completely inhibited the closure of mechanical wounds in T84 monolayers. Confocal microscopy using MAbs...... BM2 (laminin alpha 3 subunit) and 6F12 (laminin beta 3 subunit) revealed that laminin-5 is deposited in a basal matrix that extends into the wound. The MAbs 4E10 (laminin beta 1 subunit) and C4 (laminin beta 2 subunit) stained the lateral membranes between T84 cells. This staining was enhanced...... in cells adjoining wounds. Because T84 cells stained faintly with MAbs 4C7 (laminin alpha 1 subunit) and with MAbs 4F11 and 1B4 (laminin alpha 2 subunit), we suggest that expression of laminins 6 and 7 is enhanced in response to wounding. The alpha 3 beta 1 integrin and the alpha 6-containing integrins...

  4. Balloon sizing and transcatheter closure of acute atrial septal defects guided by magnetic resonance fluoroscopy: assessment and validation in a large animal model.

    Science.gov (United States)

    Schalla, Simon; Saeed, Maythem; Higgins, Charles B; Weber, Oliver; Martin, Alastair; Moore, Phillip

    2005-03-01

    To quantitatively assess atrial septal defects (ASDs) with small shunts using MRI followed by transcatheter closure monitored by MR fluoroscopy. Acute ASDs were created in 14 pigs under x-ray fluoroscopy. Six animals were studied in order to select MR-compatible delivery systems and imaging strategies. ASDs in eight animals were examined with balloon sizing under MR fluoroscopy, flow measurements, and contrast media injections, after which transcatheter closure was performed under MR fluoroscopy. The delivery system was assembled from commercially available materials. The ratio of pulmonary to systemic flow (Qp/Qs) was reduced from 1.23 +/- 0.15 before ASD closure to 1.07 +/- 0.11 after ASD closure (P animals Qp/Qs was close to 1.0 before closure despite the presence of defects >15 mm. The ASDs were measurable with MR balloon sizing in all of the animals. Balloon sizing was identical with MR (16.9 +/- 2.3 mm) and x-ray fluoroscopy (17.1 +/- 1.3 mm). The in-house-assembled delivery system allowed successful placement of closure devices under MR guidance. Assessment and closure of small shunts with MR fluoroscopy is feasible. A barrier to the rapid implementation of transcatheter closure in patients is uncertainty about the MR safety of guidewires and device delivery systems. (c) 2005 Wiley-Liss, Inc.

  5. Development of an arid site closure plan

    International Nuclear Information System (INIS)

    Nyhan, J.W.; Barnes, F.J.

    1987-01-01

    This document describes the development of a prototype plan for the effective closure and stabilization of an arid low-level waste disposal site. This plan will provide demonstrated closure techniques for a trench in a disposal site at Los Alamos. The accuracy of modeling soil water storage by two hydrologic models, CREAMS and HELP, was tested by comparing simulation results with field measurements of soil moisture in eight experimental landfill cover systems having a range of well-defined soil profiles and vegetative covers. Regression analysis showed that CREAMS generally represented soil moisture more accurately than HELP simulations. Precautions for determining parameter values for model input and for interpreting simulation results are discussed. A specific example is presented showing how the field-validated hydrologic models can be used to develop a final prototype closure plan. 15 refs., 13 figs., 3 tabs

  6. An Energy-Equivalent d⁺/d-Damage Model with Enhanced Microcrack Closure-Reopening Capabilities for Cohesive-Frictional Materials.

    Science.gov (United States)

    Cervera, Miguel; Tesei, Claudia

    2017-04-20

    In this paper, an energy-equivalent orthotropic d ⁺/ d - damage model for cohesive-frictional materials is formulated. Two essential mechanical features are addressed, the damage-induced anisotropy and the microcrack closure-reopening (MCR) effects, in order to provide an enhancement of the original d ⁺/ d - model proposed by Faria et al. 1998, while keeping its high algorithmic efficiency unaltered. First, in order to ensure the symmetry and positive definiteness of the secant operator, the new formulation is developed in an energy-equivalence framework. This proves thermodynamic consistency and allows one to describe a fundamental feature of the orthotropic damage models, i.e., the reduction of the Poisson's ratio throughout the damage process. Secondly, a "multidirectional" damage procedure is presented to extend the MCR capabilities of the original model. The fundamental aspects of this approach, devised for generic cyclic conditions, lie in maintaining only two scalar damage variables in the constitutive law, while preserving memory of the degradation directionality. The enhanced unilateral capabilities are explored with reference to the problem of a panel subjected to in-plane cyclic shear, with or without vertical pre-compression; depending on the ratio between shear and pre-compression, an absent, a partial or a complete stiffness recovery is simulated with the new multidirectional procedure.

  7. Achieving closure at Fernald

    Energy Technology Data Exchange (ETDEWEB)

    Bradburne, John; Patton, Tisha C.

    2001-02-25

    When Fluor Fernald took over the management of the Fernald Environmental Management Project in 1992, the estimated closure date of the site was more than 25 years into the future. Fluor Fernald, in conjunction with DOE-Fernald, introduced the Accelerated Cleanup Plan, which was designed to substantially shorten that schedule and save taxpayers more than $3 billion. The management of Fluor Fernald believes there are three fundamental concerns that must be addressed by any contractor hoping to achieve closure of a site within the DOE complex. They are relationship management, resource management and contract management. Relationship management refers to the interaction between the site and local residents, regulators, union leadership, the workforce at large, the media, and any other interested stakeholder groups. Resource management is of course related to the effective administration of the site knowledge base and the skills of the workforce, the attraction and retention of qualified a nd competent technical personnel, and the best recognition and use of appropriate new technologies. Perhaps most importantly, resource management must also include a plan for survival in a flat-funding environment. Lastly, creative and disciplined contract management will be essential to effecting the closure of any DOE site. Fluor Fernald, together with DOE-Fernald, is breaking new ground in the closure arena, and ''business as usual'' has become a thing of the past. How Fluor Fernald has managed its work at the site over the last eight years, and how it will manage the new site closure contract in the future, will be an integral part of achieving successful closure at Fernald.

  8. Tank closure reducing grout

    Energy Technology Data Exchange (ETDEWEB)

    Caldwell, T.B.

    1997-04-18

    A reducing grout has been developed for closing high level waste tanks at the Savannah River Site in Aiken, South Carolina. The grout has a low redox potential, which minimizes the mobility of Sr{sup 90}, the radionuclide with the highest dose potential after closure. The grout also has a high pH which reduces the solubility of the plutonium isotopes. The grout has a high compressive strength and low permeability, which enhances its ability to limit the migration of contaminants after closure. The grout was designed and tested by Construction Technology Laboratories, Inc. Placement methods were developed by the Savannah River Site personnel.

  9. Tank closure reducing grout

    International Nuclear Information System (INIS)

    Caldwell, T.B.

    1997-01-01

    A reducing grout has been developed for closing high level waste tanks at the Savannah River Site in Aiken, South Carolina. The grout has a low redox potential, which minimizes the mobility of Sr 90 , the radionuclide with the highest dose potential after closure. The grout also has a high pH which reduces the solubility of the plutonium isotopes. The grout has a high compressive strength and low permeability, which enhances its ability to limit the migration of contaminants after closure. The grout was designed and tested by Construction Technology Laboratories, Inc. Placement methods were developed by the Savannah River Site personnel

  10. Evaluation of the Momentum Closure Schemes in MPAS-Ocean

    Science.gov (United States)

    Zhao, Shimei; Liu, Yudi; Liu, Wei

    2018-04-01

    In order to compare and evaluate the performances of the Laplacian viscosity closure, the biharmonic viscosity closure, and the Leith closure momentum schemes in the MPAS-Ocean model, a variety of physical quantities, such as the relative reference potential energy (RPE) change, the RPE time change rate (RPETCR), the grid Reynolds number, the root mean square (RMS) of kinetic energy, and the spectra of kinetic energy and enstrophy, are calculated on the basis of results of a 3D baroclinic periodic channel. Results indicate that: 1) The RPETCR demonstrates a saturation phenomenon in baroclinic eddy tests. The critical grid Reynolds number corresponding to RPETCR saturation differs between the three closures: the largest value is in the biharmonic viscosity closure, followed by that in the Laplacian viscosity closure, and that in the Leith closure is the smallest. 2) All three closures can effectively suppress spurious dianeutral mixing by reducing the grid Reynolds number under sub-saturation conditions of the RPETCR, but they can also damage certain physical processes. Generally, the damage to the rotation process is greater than that to the advection process. 3) The dissipation in the biharmonic viscosity closure is strongly dependent on scales. Most dissipation concentrates on small scales, and the energy of small-scale eddies is often transferred to large-scale kinetic energy. The viscous dissipation in the Laplacian viscosity closure is the strongest on various scales, followed by that in the Leith closure. Note that part of the small-scale kinetic energy is also transferred to large-scale kinetic energy in the Leith closure. 4) The characteristic length scale L and the dimensionless parameter D in the Leith closure are inherently coupled. The RPETCR is inversely proportional to the product of D and L. When the product of D and L is constant, both the simulated RPETCR and the inhibition of spurious dianeutral mixing are the same in all tests using the Leith

  11. Mail Office annual closure

    CERN Multimedia

    2013-01-01

    On the occasion of the annual closure of CERN, there will be no mail distributed on Friday 20 December 2013 but mail will be collected in the morning. Nevertheless, you will still be able to bring your outgoing mail to Building 555-R-002 until 12 noon.  

  12. ROCKET PORT CLOSURE

    Science.gov (United States)

    Mattingly, J.T.

    1963-02-12

    This invention provides a simple pressure-actuated closure whereby windowless observation ports are opened to the atmosphere at preselected altitudes. The closure comprises a disk which seals a windowless observation port in rocket hull. An evacuated instrument compartment is affixed to the rocket hull adjacent the inner surface of the disk, while the outer disk surface is exposed to the atmosphere through which the rocket is traveling. The pressure differential between the evacuated instrument compartment and the relatively high pressure external atmosphere forces the disk against the edge of the observation port, thereby effecting a tight seai. The instrument compartment is evacuated to a pressure equal to the atmospheric pressure existing at the altitude at which it is desiretl that the closure should open. When the rocket reaches this preselected altitude, the inwardly directed atmospheric force on the disk is just equaled by the residual air pressure force within the instrument compartment. Consequently, the closure disk falls away and uncovers the open observation port. The separation of the disk from the rocket hull actuates a switch which energizes the mechanism of a detecting instrument disposed within the instrument compartment. (AE C)

  13. Simulating school closure policies for cost effective pandemic decision making

    Directory of Open Access Journals (Sweden)

    Araz Ozgur M

    2012-06-01

    Full Text Available Abstract Background Around the globe, school closures were used sporadically to mitigate the 2009 H1N1 influenza pandemic. However, such closures can detrimentally impact economic and social life. Methods Here, we couple a decision analytic approach with a mathematical model of influenza transmission to estimate the impact of school closures in terms of epidemiological and cost effectiveness. Our method assumes that the transmissibility and the severity of the disease are uncertain, and evaluates several closure and reopening strategies that cover a range of thresholds in school-aged prevalence (SAP and closure durations. Results Assuming a willingness to pay per quality adjusted life-year (QALY threshold equal to the US per capita GDP ($46,000, we found that the cost effectiveness of these strategies is highly dependent on the severity and on a willingness to pay per QALY. For severe pandemics, the preferred strategy couples the earliest closure trigger (0.5% SAP with the longest duration closure (24 weeks considered. For milder pandemics, the preferred strategies also involve the earliest closure trigger, but are shorter duration (12 weeks for low transmission rates and variable length for high transmission rates. Conclusions These findings highlight the importance of obtaining early estimates of pandemic severity and provide guidance to public health decision-makers for effectively tailoring school closures strategies in response to a newly emergent influenza pandemic.

  14. Simulating school closure policies for cost effective pandemic decision making.

    Science.gov (United States)

    Araz, Ozgur M; Damien, Paul; Paltiel, David A; Burke, Sean; van de Geijn, Bryce; Galvani, Alison; Meyers, Lauren Ancel

    2012-06-18

    Around the globe, school closures were used sporadically to mitigate the 2009 H1N1 influenza pandemic. However, such closures can detrimentally impact economic and social life. Here, we couple a decision analytic approach with a mathematical model of influenza transmission to estimate the impact of school closures in terms of epidemiological and cost effectiveness. Our method assumes that the transmissibility and the severity of the disease are uncertain, and evaluates several closure and reopening strategies that cover a range of thresholds in school-aged prevalence (SAP) and closure durations. Assuming a willingness to pay per quality adjusted life-year (QALY) threshold equal to the US per capita GDP ($46,000), we found that the cost effectiveness of these strategies is highly dependent on the severity and on a willingness to pay per QALY. For severe pandemics, the preferred strategy couples the earliest closure trigger (0.5% SAP) with the longest duration closure (24 weeks) considered. For milder pandemics, the preferred strategies also involve the earliest closure trigger, but are shorter duration (12 weeks for low transmission rates and variable length for high transmission rates). These findings highlight the importance of obtaining early estimates of pandemic severity and provide guidance to public health decision-makers for effectively tailoring school closures strategies in response to a newly emergent influenza pandemic.

  15. Stress and Fatigue Life Modeling of Cannon Breech Closures Including Effects of Material Strength and Residual Stress

    National Research Council Canada - National Science Library

    Underwood, John

    2000-01-01

    ...; overload residual stress. Modeling of applied and residual stresses at the location of the fatigue failure site is performed by elastic-plastic finite element analysis using ABAQUS and by solid...

  16. Summer season | Cafeteria closures

    CERN Multimedia

    2013-01-01

    Please note the following cafeteria closures over the summer season: Bldg. 54 closed from 29/07/2013 to 06/09/2013. Bldg. 13: closed from 13/07/2013 to 06/09/2013. Restaurant No. 2, table service (brasserie and restaurant): closed from 01/08/2013 to 06/09/2013. Bldg. 864: closed from 29/07/2013 to 06/09/2013. Bldg. 865: closed from 29/07/2013 to 06/09/2013.

  17. Influence of Superparameterization and a Higher-Order Turbulence Closure on Rainfall Bias Over Amazonia in Community Atmosphere Model Version 5: How Parameterization Changes Rainfall

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Kai [Jackson School of Geosciences, University of Texas at Austin, Austin TX USA; Fu, Rong [Jackson School of Geosciences, University of Texas at Austin, Austin TX USA; Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles CA USA; Shaikh, Muhammad J. [Jackson School of Geosciences, University of Texas at Austin, Austin TX USA; Ghan, Steven [Pacific Northwest National Laboratory, Richland WA USA; Wang, Minghuai [Institute for Climate and Global Change Research and School of Atmospheric Sciences, Nanjing University, Nanjing China; Collaborative Innovation Center of Climate Change, Nanjing China; Leung, L. Ruby [Pacific Northwest National Laboratory, Richland WA USA; Dickinson, Robert E. [Jackson School of Geosciences, University of Texas at Austin, Austin TX USA; Marengo, Jose [Centro Nacional de Monitoramento e Alertas aos Desastres Naturais, São Jose dos Campos Brazil

    2017-09-21

    We evaluate the Community Atmosphere Model Version 5 (CAM5) with a higher-order turbulence closure scheme, named Cloud Layers Unified By Binomials (CLUBB), and a Multiscale Modeling Framework (MMF) with two different microphysics configurations to investigate their influences on rainfall simulations over Southern Amazonia. The two different microphysics configurations in MMF are the one-moment cloud microphysics without aerosol treatment (SAM1MOM) and two-moment cloud microphysics coupled with aerosol treatment (SAM2MOM). Results show that both MMF-SAM2MOM and CLUBB effectively reduce the low biases of rainfall, mainly during the wet season. The CLUBB reduces low biases of humidity in the lower troposphere with further reduced shallow clouds. The latter enables more surface solar flux, leading to stronger convection and more rainfall. MMF, especially MMF-SAM2MOM, unstablizes the atmosphere with more moisture and higher atmospheric temperatures in the atmospheric boundary layer, allowing the growth of more extreme convection and further generating more deep convection. MMF-SAM2MOM significantly increases rainfall in the afternoon, but it does not reduce the early bias of the diurnal rainfall peak; LUBB, on the other hand, delays the afternoon peak time and produces more precipitation in the early morning, due to more realistic gradual transition between shallow and deep convection. MMF appears to be able to realistically capture the observed increase of relative humidity prior to deep convection, especially with its two-moment configuration. In contrast, in CAM5 and CAM5 with CLUBB, occurrence of deep convection in these models appears to be a result of stronger heating rather than higher relative humidity.

  18. Primary closure after carotid endarterectomy is not inferior to other closure techniques.

    Science.gov (United States)

    Avgerinos, Efthymios D; Chaer, Rabih A; Naddaf, Abdallah; El-Shazly, Omar M; Marone, Luke; Makaroun, Michel S

    2016-09-01

    Primary closure after carotid endarterectomy (CEA) has been much maligned as an inferior technique with worse outcomes than in patch closure. Our purpose was to compare perioperative and long-term results of different CEA closure techniques in a large institutional experience. A consecutive cohort of CEAs between January 1, 2000, and December 31, 2010, was retrospectively analyzed. Closure technique was used to divide patients into three groups: primary longitudinal arteriotomy closure (PRC), patch closure (PAC), and eversion closure (EVC). End points were perioperative events, long-term strokes, and restenosis ≥70%. Multivariate regression models were used to assess the effect of baseline predictors. There were 1737 CEA cases (bilateral, 143; mean age, 71.4 ± 9.3 years; 56.2% men; 35.3% symptomatic) performed during the study period with a mean clinical follow-up of 49.8 ± 36.4 months (range, 0-155 months). More men had primary closure, but other demographic and baseline symptoms were similar between groups. Half the patients had PAC, with the rest evenly distributed between PRC and EVC. The rate of nerve injury was 2.7%, the rate of reintervention for hematoma was 1.5%, and the length of hospital stay was 2.4 ± 3.0 days, with no significant differences among groups. The combined stroke and death rate was 2.5% overall and 3.9% and 1.7% in the symptomatic and asymptomatic cohort, respectively. Stroke and death rates were similar between groups: PRC, 11 (2.7%); PAC, 19 (2.2%); EVC, 13 (2.9%). Multivariate analysis showed baseline symptomatic disease (odds ratio, 2.4; P = .007) and heart failure (odds ratio, 3.1; P = .003) as predictors of perioperative stroke and death, but not the type of closure. Cox regression analysis demonstrated, among other risk factors, no statin use (hazard ratio, 2.1; P = .008) as a predictor of ipsilateral stroke and severe (glomerular filtration rate <30 mL/min/1.73 m(2)) renal insufficiency (hazard ratio, 2.6; P

  19. Uncertainty Quantification of Multi-Phase Closures

    Energy Technology Data Exchange (ETDEWEB)

    Nadiga, Balasubramanya T. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Baglietto, Emilio [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2017-10-27

    In the ensemble-averaged dispersed phase formulation used for CFD of multiphase ows in nuclear reactor thermohydraulics, closures of interphase transfer of mass, momentum, and energy constitute, by far, the biggest source of error and uncertainty. Reliable estimators of this source of error and uncertainty are currently non-existent. Here, we report on how modern Validation and Uncertainty Quanti cation (VUQ) techniques can be leveraged to not only quantify such errors and uncertainties, but also to uncover (unintended) interactions between closures of di erent phenomena. As such this approach serves as a valuable aide in the research and development of multiphase closures. The joint modeling of lift, drag, wall lubrication, and turbulent dispersion|forces that lead to tranfer of momentum between the liquid and gas phases|is examined in the frame- work of validation of the adiabatic but turbulent experiments of Liu and Banko , 1993. An extensive calibration study is undertaken with a popular combination of closure relations and the popular k-ϵ turbulence model in a Bayesian framework. When a wide range of super cial liquid and gas velocities and void fractions is considered, it is found that this set of closures can be validated against the experimental data only by allowing large variations in the coe cients associated with the closures. We argue that such an extent of variation is a measure of uncertainty induced by the chosen set of closures. We also nd that while mean uid velocity and void fraction pro les are properly t, uctuating uid velocity may or may not be properly t. This aspect needs to be investigated further. The popular set of closures considered contains ad-hoc components and are undesirable from a predictive modeling point of view. Consequently, we next consider improvements that are being developed by the MIT group under CASL and which remove the ad-hoc elements. We use non-intrusive methodologies for sensitivity analysis and calibration (using

  20. Application of GRAM model for estimating groundwater rebound after mine closure: a case study at abandoned underground mines in Korea

    Science.gov (United States)

    Choi, Yosoon; Baek, Jieun; Kim, Dukmin

    2017-04-01

    Cessation of dewatering usually results in groundwater rebound after closing an underground mine because the mine voids and surrounding strata flood up to the levels of decant points such as shafts and drifts. The objective of this study was to develop a program for analyzing groundwater rebound in abandoned underground mines. Several numerical models have been developed to predict the timing, magnitude and location of discharges resulting from groundwater rebound. This study reviewed the numerical models such as MODFLOW, GRAM and MINEDW, and compares their scopes of assessment at different spatial and time scales. In addition, a GRAM(Groundwater Rebound in Abandoned Mine workings) model-based program, named GRAM for Windows, was developed using Visual Studio.NET 2012. The program, GRAM for Windows, is comprised of the graphic user interface and the simulation engine modules. Input and output files of the program were designed by considering the characteristics of GRAM model. Some case studies were performed to analyze groundwater rebound at abandoned underground mines in Korea. The comparisons of simulated and observed groundwater levels at the shaft of underground mine showed that the developed program can be used effectively to analyze and estimate the groundwater rebound in the abandoned underground mine.

  1. SPAM Detection Server Model Inspired by the Dionaea Muscipula Closure Mechanism: An Alternative Approach for Natural Computing Challenges

    Science.gov (United States)

    de Souza Pereira Lopes, Rodrigo Arthur; Carrari R. Lopes, Lia; Mustaro, Pollyana Notargiacomo

    Natural computing has been an increasingly evolving field in the last few years. Focusing on the interesting behaviours offered by nature and biological processes, this work intends to apply the metaphor of the carnivorous plant "Dionaea muscipula" as a complementary defence system against a recurring problem regarding internet and e-mails: spam. The metaphor model presents relevant aspects for further implementation and debate.

  2. How Difficult is it to Reduce Low-Level Cloud Biases With the Higher-Order Turbulence Closure Approach in Climate Models?

    Science.gov (United States)

    Xu, Kuan-Man

    2015-01-01

    Low-level clouds cover nearly half of the Earth and play a critical role in regulating the energy and hydrological cycle. Despite the fact that a great effort has been put to advance the modeling and observational capability in recent years, low-level clouds remains one of the largest uncertainties in the projection of future climate change. Low-level cloud feedbacks dominate the uncertainty in the total cloud feedback in climate sensitivity and projection studies. These clouds are notoriously difficult to simulate in climate models due to its complicated interactions with aerosols, cloud microphysics, boundary-layer turbulence and cloud dynamics. The biases in both low cloud coverage/water content and cloud radiative effects (CREs) remain large. A simultaneous reduction in both cloud and CRE biases remains elusive. This presentation first reviews the effort of implementing the higher-order turbulence closure (HOC) approach to representing subgrid-scale turbulence and low-level cloud processes in climate models. There are two HOCs that have been implemented in climate models. They differ in how many three-order moments are used. The CLUBB are implemented in both CAM5 and GDFL models, which are compared with IPHOC that is implemented in CAM5 by our group. IPHOC uses three third-order moments while CLUBB only uses one third-order moment while both use a joint double-Gaussian distribution to represent the subgrid-scale variability. Despite that HOC is more physically consistent and produces more realistic low-cloud geographic distributions and transitions between cumulus and stratocumulus regimes, GCMs with traditional cloud parameterizations outperform in CREs because tuning of this type of models is more extensively performed than those with HOCs. We perform several tuning experiments with CAM5 implemented with IPHOC in an attempt to produce the nearly balanced global radiative budgets without deteriorating the low-cloud simulation. One of the issues in CAM5-IPHOC

  3. A kinematic view of loop closure.

    Science.gov (United States)

    Coutsias, Evangelos A; Seok, Chaok; Jacobson, Matthew P; Dill, Ken A

    2004-03-01

    We consider the problem of loop closure, i.e., of finding the ensemble of possible backbone structures of a chain segment of a protein molecule that is geometrically consistent with preceding and following parts of the chain whose structures are given. We reduce this problem of determining the loop conformations of six torsions to finding the real roots of a 16th degree polynomial in one variable, based on the robotics literature on the kinematics of the equivalent rotator linkage in the most general case of oblique rotators. We provide a simple intuitive view and derivation of the polynomial for the case in which each of the three pair of torsional axes has a common point. Our method generalizes previous work on analytical loop closure in that the torsion angles need not be consecutive, and any rigid intervening segments are allowed between the free torsions. Our approach also allows for a small degree of flexibility in the bond angles and the peptide torsion angles; this substantially enlarges the space of solvable configurations as is demonstrated by an application of the method to the modeling of cyclic pentapeptides. We give further applications to two important problems. First, we show that this analytical loop closure algorithm can be efficiently combined with an existing loop-construction algorithm to sample loops longer than three residues. Second, we show that Monte Carlo minimization is made severalfold more efficient by employing the local moves generated by the loop closure algorithm, when applied to the global minimization of an eight-residue loop. Our loop closure algorithm is freely available at http://dillgroup. ucsf.edu/loop_closure/. Copyright 2004 Wiley Periodicals, Inc. J Comput Chem 25: 510-528, 2004

  4. Fatigue crack closure: A review

    Science.gov (United States)

    Kemp, R. M. J.

    1990-09-01

    The phenomenon of fatigue crack closure is now recognized as one of the most influential mechanisms operating during fatigue. This literature survey traces the development of research into fatigue crack closure and has been divided to present the two major approaches. The first part covers early work carried out between 1970 to 1980 which, broadly speaking, adopted a 'continuum' approach. The second part covers the period 1980 to 1988 when a mechanistic approach was widely adopted. The survey has highlighted, firstly, the critical nature of experimental technique in the achievement of a meaningful measurement of crack closure load and secondly, that a diversity of mechanisms may operate to produce closure. Particular attention has been given to crack closure in aluminum alloys and also to work relating crack closure to the corrosion fatigue situation.

  5. Delayed Macular Hole Closure

    Directory of Open Access Journals (Sweden)

    Peter Distelmaier

    2014-04-01

    Full Text Available Purpose: The presented case raises questions regarding the favorable scheduling of planned postoperative care and the ideal observation interval to decide for reoperations in macular hole surgery. Furthermore a discussion about the use of short- and long-acting gas tamponades in macular hole surgery is encouraged. Methods: We present an interventional case report and a short review of the pertinent literature. Results: We report a case of spontaneous delayed macular hole closure after vitreoretinal surgery had been performed initially without the expected success. A 73-year-old male Caucasian patient presented at our clinic with a stage 2 macular hole in his left eye. He underwent 23-gauge pars plana vitrectomy and internal limiting membrane peeling with a 20% C2F6-gas tamponade. Sixteen days after the procedure, an OCT scan revealed a persistent stage 2 macular hole, and the patient was scheduled for reoperation. Surprisingly, at the date of planned surgery, which was another 11 days later, the macular hole had resolved spontaneously without any further intervention. Conclusions: So far no common opinion exists regarding the use of short- or long-acting gas in macular hole surgery. Our case of delayed macular hole closure after complete resorption of the gas tamponade raises questions about the need and duration of strict prone positioning after surgery. Furthermore short-acting gas might be as efficient as long-acting gas. We suggest to wait with a second intervention at least 4 weeks after the initial surgery, since a delayed macular hole closure is possible.

  6. Friction or Closure

    DEFF Research Database (Denmark)

    Lundahl, Mikela

    2014-01-01

    Heritage is a discourse that aims at closure. It fixates the narrative of the past through the celebration of specific material (or sometimes immaterial non-) ob-jects. It organizes temporality and construct events and freezes time. How does this unfold in the case of the UNESCO World Heritage site...... is Stone Town in Zanzibar and the de-velopment and dissolution going on under the shadow of the UNESCO World Heritage flag; a growing tourism; a global and local increase in islamisation; and the political tension within the Tanzanian union. My main focus is narratives of the identity of Zanzibar since...

  7. 40 CFR 264.113 - Closure; time allowed for closure.

    Science.gov (United States)

    2010-07-01

    ... (CONTINUED) STANDARDS FOR OWNERS AND OPERATORS OF HAZARDOUS WASTE TREATMENT, STORAGE, AND DISPOSAL FACILITIES..., and closure and post-closure plans, and updated cost estimates and demonstrations of financial..., and removing all hazardous sludges to the extent practicable without impairing the integrity of the...

  8. RECENT PROGRESS IN DOE WASTE TANK CLOSURE

    Energy Technology Data Exchange (ETDEWEB)

    Langton, C

    2008-02-01

    The USDOE complex currently has over 330 underground storage tanks that have been used to process and store radioactive waste generated from the production of weapons materials. These tanks contain over 380 million liters of high-level and low-level radioactive waste. The waste consists of radioactively contaminated sludge, supernate, salt cake or calcine. Most of the waste exists at four USDOE locations, the Hanford Site, the Savannah River Site, the Idaho Nuclear Technology and Engineering Center and the West Valley Demonstration Project. A summary of the DOE tank closure activities was first issued in 2001. Since then, regulatory changes have taken place that affect some of the sites and considerable progress has been made in closing tanks. This paper presents an overview of the current regulatory changes and drivers and a summary of the progress in tank closures at the various sites over the intervening six years. A number of areas are addressed including closure strategies, characterization of bulk waste and residual heel material, waste removal technologies for bulk waste, heel residuals and annuli, tank fill materials, closure system modeling and performance assessment programs, lessons learned, and external reviews.

  9. Closedure - Mine Closure Technologies Resource

    Science.gov (United States)

    Kauppila, Päivi; Kauppila, Tommi; Pasanen, Antti; Backnäs, Soile; Liisa Räisänen, Marja; Turunen, Kaisa; Karlsson, Teemu; Solismaa, Lauri; Hentinen, Kimmo

    2015-04-01

    Closure of mining operations is an essential part of the development of eco-efficient mining and the Green Mining concept in Finland to reduce the environmental footprint of mining. Closedure is a 2-year joint research project between Geological Survey of Finland and Technical Research Centre of Finland that aims at developing accessible tools and resources for planning, executing and monitoring mine closure. The main outcome of the Closedure project is an updatable wiki technology-based internet platform (http://mineclosure.gtk.fi) in which comprehensive guidance on the mine closure is provided and main methods and technologies related to mine closure are evaluated. Closedure also provides new data on the key issues of mine closure, such as performance of passive water treatment in Finland, applicability of test methods for evaluating cover structures for mining wastes, prediction of water effluents from mine wastes, and isotopic and geophysical methods to recognize contaminant transport paths in crystalline bedrock.

  10. Tubular closure mechanism

    International Nuclear Information System (INIS)

    Kalen, D.D.; Mitchem, J.W.

    1981-01-01

    An apparatus is provided for closing the bore of a tube and releasably securing articles within the tube under longitudinal load. A latching member has a cylindrical section and several circumferentially-spaced elongated latches hanging down from one end of the cylinder. An elongated actuator has integral cam and spline and is partly located within the latch with the cam radially contacting the latches and the spline projecting into the circumferential spaces between the latches. The actuator is axially movable between a position in which the latches are locked to the tube walls and a position in which the latches are secured from contact with the tube walls. Means are provided for axially moving the actuator such that the cam positions the latches; and means are also provided for engaging the articles within the tube. The closure is particularly applicable to tubular irradiation surveillance specimen assembly holders used in reactors

  11. Airport Movement Area Closure Planner, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR research develops an automation tool improving temporary and permanent runway closure management. The Movement Area Closure Planner (MACP) provides airport...

  12. Turbulence modeling for hypersonic flows

    Science.gov (United States)

    Marvin, J. G.; Coakley, T. J.

    1992-01-01

    Turbulence modeling for high-speed compressible flows is described and discussed. Starting with the compressible Navier-Stokes equations, methods of statistical averaging are described by means of which the Reynolds-averaged Navier-Stokes equations are developed. Unknown averages in these equations are approximated using various closure concepts. Zero-, one-, and two-equation eddy viscosity models, algebraic stress models, and Reynolds stress transport models are discussed. Computations of supersonic and hypersonic flows obtained using several of the models are discussed and compared with experimental results. Specific examples include attached boundary-layer flows, shock-wave boundary-layer interactions, and compressible shear layers. From these examples, conclusions regarding the status of modeling and recommendations for future studies are discussed.

  13. Turbulence closure: turbulence, waves and the wave-turbulence transition – Part 1: Vanishing mean shear

    Directory of Open Access Journals (Sweden)

    H. Z. Baumert

    2009-03-01

    Full Text Available This paper extends a turbulence closure-like model for stably stratified flows into a new dynamic domain in which turbulence is generated by internal gravity waves rather than mean shear. The model turbulent kinetic energy (TKE, K balance, its first equation, incorporates a term for the energy transfer from internal waves to turbulence. This energy source is in addition to the traditional shear production. The second variable of the new two-equation model is the turbulent enstrophy (Ω. Compared to the traditional shear-only case, the Ω-equation is modified to account for the effect of the waves on the turbulence time and space scales. This modification is based on the assumption of a non-zero constant flux Richardson number in the limit of vanishing mean shear when turbulence is produced exclusively by internal waves. This paper is part 1 of a continuing theoretical development. It accounts for mean shear- and internal wave-driven mixing only in the two limits of mean shear and no waves and waves but no mean shear, respectively.

    The new model reproduces the wave-turbulence transition analyzed by D'Asaro and Lien (2000b. At small energy density E of the internal wave field, the turbulent dissipation rate (ε scales like ε~E2. This is what is observed in the deep sea. With increasing E, after the wave-turbulence transition has been passed, the scaling changes to ε~E1. This is observed, for example, in the highly energetic tidal flow near a sill in Knight Inlet. The new model further exhibits a turbulent length scale proportional to the Ozmidov scale, as observed in the ocean, and predicts the ratio between the turbulent Thorpe and Ozmidov length scales well within the range observed in the ocean.

  14. Closure report for N Reactor

    Energy Technology Data Exchange (ETDEWEB)

    1994-01-01

    This report has been prepared to satisfy Section 3156(b) of Public Law 101-189 (Reports in Connection with Permanent Closures of Department of Energy Defense Nuclear Facilities), which requires submittal of a Closure Report to Congress by the Secretary of Energy upon the permanent cessation of production operations at a US Department of Energy (DOE) defense nuclear facility (Watkins 1991). This closure report provides: (1) A complete survey of the environmental problems at the facility; (2) Budget quality data indicating the cost of environmental restoration and other remediation and cleanup efforts at the facility; (3) A proposed cleanup schedule.

  15. Closure report for N Reactor

    International Nuclear Information System (INIS)

    1994-01-01

    This report has been prepared to satisfy Section 3156(b) of Public Law 101-189 (Reports in Connection with Permanent Closures of Department of Energy Defense Nuclear Facilities), which requires submittal of a Closure Report to Congress by the Secretary of Energy upon the permanent cessation of production operations at a US Department of Energy (DOE) defense nuclear facility (Watkins 1991). This closure report provides: (1) A complete survey of the environmental problems at the facility; (2) Budget quality data indicating the cost of environmental restoration and other remediation and cleanup efforts at the facility; (3) A proposed cleanup schedule

  16. Evaluation of a novel trocar-site closure and comparison with a standard Carter-Thomason closure device.

    Science.gov (United States)

    del Junco, Michael; Okhunov, Zhamshid; Juncal, Samuel; Yoon, Renai; Landman, Jaime

    2014-07-01

    The aim of this study was to evaluate and compare a novel trocars-site closure device, the WECK EFx™ Endo Fascial Closure System (EFx) with the Carter-Thomason CloseSure System® (CT) for the closure of laparoscopic trocar site defects created by a 12-mm dilating trocar. We created standardized laparoscopic trocars-site abdominal wall defects in cadaver models using a standard 12-mm laparoscopic dilating trocar. Trocar defects were closed in a randomized fashion using one of the two closure systems. We recorded time and number of attempts needed for complete defect closure. In addition, we recorded the ability to maintain pneumoperitoneum, endoscopic visualization, safety, security, and facility based on the surgeon's subjective evaluations. We compared outcomes for the EFx and CT closure systems. We created 72 standardized laparoscopic trocars-site abdominal wall defects. The mean time needed for complete defect closure was 98.53 seconds (±28.9) for the EFx compared with 133.61 seconds (±54.61) for the CT (Psafety were 2.92 for EFx vs 2.19 for CT (Pvs 1.83 for EFx and CT, respectively (Pvs 2.33 for CT (P=0.022). No significant difference was observed between the EFx and the CT systems for endoscopic visualization (2.28 vs 2.50, P=0.080). In this in vitro cadaver trial, the EFx was superior in terms of time needed to complete defect closure, safety, and facility. CT was superior in terms of maintenance of pneumoperitoneum. Both systems were equal in the number of attempts needed to complete the defect closure and endoscopic visualization.

  17. Closure and Sealing Design Calculation

    International Nuclear Information System (INIS)

    T. Lahnalampi; J. Case

    2005-01-01

    The purpose of the ''Closure and Sealing Design Calculation'' is to illustrate closure and sealing methods for sealing shafts, ramps, and identify boreholes that require sealing in order to limit the potential of water infiltration. In addition, this calculation will provide a description of the magma that can reduce the consequences of an igneous event intersecting the repository. This calculation will also include a listing of the project requirements related to closure and sealing. The scope of this calculation is to: summarize applicable project requirements and codes relating to backfilling nonemplacement openings, removal of uncommitted materials from the subsurface, installation of drip shields, and erecting monuments; compile an inventory of boreholes that are found in the area of the subsurface repository; describe the magma bulkhead feature and location; and include figures for the proposed shaft and ramp seals. The objective of this calculation is to: categorize the boreholes for sealing by depth and proximity to the subsurface repository; develop drawing figures which show the location and geometry for the magma bulkhead; include the shaft seal figures and a proposed construction sequence; and include the ramp seal figure and a proposed construction sequence. The intent of this closure and sealing calculation is to support the License Application by providing a description of the closure and sealing methods for the Safety Analysis Report. The closure and sealing calculation will also provide input for Post Closure Activities by describing the location of the magma bulkhead. This calculation is limited to describing the final configuration of the sealing and backfill systems for the underground area. The methods and procedures used to place the backfill and remove uncommitted materials (such as concrete) from the repository and detailed design of the magma bulkhead will be the subject of separate analyses or calculations. Post-closure monitoring will not

  18. Amnioserosa cell constriction but not epidermal actin cable tension autonomously drives dorsal closure.

    Science.gov (United States)

    Pasakarnis, Laurynas; Frei, Erich; Caussinus, Emmanuel; Affolter, Markus; Brunner, Damian

    2016-11-01

    Tissue morphogenesis requires coordination of multiple force-producing components. During dorsal closure in fly embryogenesis, an epidermis opening closes. A tensioned epidermal actin/MyosinII cable, which surrounds the opening, produces a force that is thought to combine with another MyosinII force mediating apical constriction of the amnioserosa cells that fill the opening. A model proposing that each force could autonomously drive dorsal closure was recently challenged by a model in which the two forces combine in a ratchet mechanism. Acute force elimination via selective MyosinII depletion in one or the other tissue shows that the amnioserosa tissue autonomously drives dorsal closure while the actin/MyosinII cable cannot. These findings exclude both previous models, although a contribution of the ratchet mechanism at dorsal closure onset remains likely. This shifts the current view of dorsal closure being a combinatorial force-component system to a single tissue-driven closure event.

  19. Levels of control and closure in complex semiotic systems

    Science.gov (United States)

    Joslyn

    2000-01-01

    It is natural to advance closures as atomic processes of universal evolution, and to analyze this concept specifically. Real complex systems like organisms and complex mechanisms cannot exist at either extreme of complete closure or lack of closure, nevertheless we should consider the properties of closures in general, the introduction of boundaries, a corresponding stability, the establishment of system autonomy and identity, and thereby the introduction of emergent new system of potentially new types. Our focus should move from simple physical closure of common objects and classical self-organizing systems to semiotically closed systems that maintain cyclic relations of perception, interpretation, decision, and action with their environments. Thus, issues arise concerning the use and interpretation of symbols, representations, and/or internal models (whether explicit or implicit) by the system; and the syntactic, semantic, and pragmatic relations among the sign tokens, their interpretations, and their use or function for the systems in question. Primitive semiotic closures are hypothesized as equivalent to simple control systems, and in turn equivalent to simple organisms. This leads us directly to the grand hierarchical control theories of Turchin, Powers, and Albus, which provide an explicit mechanism for the formation of new levels within complex semiotically closed systems.

  20. Fuel channel closure and adapter

    International Nuclear Information System (INIS)

    Cashen, W.S.

    1985-01-01

    This invention provides a mechanical closure/actuating ram combination particularly suited for use in sealing the ends of the pressure tubes when a CANDU-type reactor is refueled. It provides a cluster that may be inserted into a fuel channel end fitting to provide at least partial closing off of a pressure tube while permitting the disengagement of the fueling machine and its withdrawal from the closure for other purposes. The invention also provides a ram/closure combination wherein the application of loading force to a deformable sealing disk is regulated by a massive load bar component forming part of the fueling machine and being therefore accessible for maintenance or replacement

  1. Organisational closure in biological organisms.

    Science.gov (United States)

    Mossio, Matteo; Moreno, Alvaro

    2010-01-01

    The central aim of this paper consists in arguing that biological organisms realize a specific kind of causal regime that we call "organisational closure"; i.e., a distinct level of causation, operating in addition to physical laws, generated by the action of material structures acting as constraints. We argue that organisational closure constitutes a fundamental property of biological systems since even its minimal instances are likely to possess at least some of the typical features of biological organisation as exhibited by more complex organisms. Yet, while being a necessary condition for biological organization, organisational closure underdetermines, as such, the whole set of requirements that a system has to satisfy in order to be taken as a paradigmatic example of organism. As we suggest, additional properties, as modular templates and control mechanisms via dynamical decoupling between constraints, are required to get the complexity typical of full-fledged biological organisms.

  2. 40 CFR 265.280 - Closure and post-closure.

    Science.gov (United States)

    2010-07-01

    ... contaminants caused by wind erosion; and (4) Compliance with § 265.276 concerning the growth of food-chain... and post-closure care objectives of paragraph (a) of this section: (1) Type and amount of hazardous..., including amount, frequency, and pH of precipitation; (5) Geological and soil profiles and surface and...

  3. Outcome of colostomy closure with different skin closure techniques ...

    African Journals Online (AJOL)

    of colostomy closure were recorded, 70 in Group A and 81 in Group B. Results: Statistical analysis of the data showed no statistically significant difference in wound infection and anastomotic leak between the two groups. On postoperative follow-up, wound assessment showed significantly better cosmesis in the no drain ...

  4. 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.

  5. Vacuum assisted closure in coloproctology

    NARCIS (Netherlands)

    Bemelman, W. A.

    2009-01-01

    Vacuum-assisted closure has earned its indications in coloproctology. It has been described with variable results in the treatment of large perineal defects after abdominoperineal excision, in the treatment of stoma dehiscence and perirectal abscesses. The most promising indication for

  6. An improvised wound closure system

    NARCIS (Netherlands)

    Lapid, Oren

    2006-01-01

    BACKGROUND: Skin stretching harnesses the same viscoelastic properties of the skin as expansion, with the difference that the forces are applied externally and not internally. An improvised system for wound closure is presented. METHOD: The system is assembled using silicone vascular loops used as

  7. Abdominal wound closure: current perspectives

    Directory of Open Access Journals (Sweden)

    Williams ZF

    2015-12-01

    Full Text Available Zachary F Williams, William W Hope Department of Surgery, South East Area Health Education Center, New Hanover Regional Medical Center, Wilmington, NC, USA Abstract: This review examines both early and late wound complications following laparotomy closure, with particular emphasis on technical aspects that reduce hernia formation. Abdominal fascial closure is an area of considerable variation within the field of general surgery. The formation of hernias following abdominal wall incisions continues to be a challenging problem. Ventral hernia repairs are among the most common surgeries performed by general surgeons, and despite many technical advances in the field, incisional hernia rates remain high. Much attention and research has been directed to the surgical management of hernias. Less focus has been placed on prevention of hernia formation despite its obvious importance. This review examines the effects of factors such as the type of incision, suture type and size, closure method, patient risk factors, and the use of prophylactic mesh. Keywords: incisional, abdominal, hernia, prevention, wound closure techniques 

  8. Telephone switchboard closure | 19 December

    CERN Document Server

    2014-01-01

    Exceptionally, the telephone switchboard will close at 4 p.m. on Friday, 19 December, instead of the usual time of 6 p.m., to allow time for closing all systems properly before the annual closure. Therefore, switchboard operator assistance to transfer calls from/to external lines will stop. All other phone services will run as usual.

  9. CIRSE Vascular Closure Device Registry

    International Nuclear Information System (INIS)

    Reekers, Jim A.; Müller-Hülsbeck, Stefan; Libicher, Martin; Atar, Eli; Trentmann, Jens; Goffette, Pierre; Borggrefe, Jan; Zeleňák, Kamil; Hooijboer, Pieter; Belli, Anna-Maria

    2011-01-01

    Purpose: Vascular closure devices are routinely used after many vascular interventional radiology procedures. However, there have been no major multicenter studies to assess the safety and effectiveness of the routine use of closure devices in interventional radiology. Methods: The CIRSE registry of closure devices with an anchor and a plug started in January 2009 and ended in August 2009. A total of 1,107 patients were included in the registry. Results: Deployment success was 97.2%. Deployment failure specified to access type was 8.8% [95% confidence interval (95% CI) 5.0–14.5] for antegrade access and 1.8% (95% CI 1.1–2.9) for retrograde access (P = 0.001). There was no difference in deployment failure related to local PVD at the access site. Calcification was a reason for deployment failure in only 5.9 cm, and two vessel occlusions. Conclusion: The conclusion of this registry of closure devices with an anchor and a plug is that the use of this device in interventional radiology procedures is safe, with a low incidence of serious access site complications. There seems to be no difference in complications between antegrade and retrograde access and other parameters.

  10. Fatigue testing of three peristernal median sternotomy closure techniques.

    Science.gov (United States)

    Wangsgard, Cameron; Cohen, David J; Griffin, Lanny V

    2008-09-24

    Failure of a sternotomy closure because of closure system fatigue is a complication that may result in dehiscence and put the individual at risk for serious complications. The purpose of this study was to assess the fatigue performance of three peristernal median sternotomy closure techniques (figure-of-eight stainless-steel wires, figure-of-eight stainless-steel cables, or Pectofix Dynamic Sternal Fixation [DSF] stainless-steel plates) in order to quantify the potential risk of fatigue failure of these devices when subject to cyclic loads in physiologically relevant loading directions. All tests were conducted on polyurethane foam sternal models. A cardiothoracic surgeon divided each sternal model longitudinally and repaired it with a closure device. Tests were performed using a materials testing system that applied cyclic loading in a uniaxial direction until the test model catastrophically broke or data run-out occurred. For each loading direction (lateral distraction and longitudinal shear), five trials of each closure technique were tested. Life data and location of device failure (if present) were evaluated. Statistical analysis was performed using regression with life data allowed for correlation between life data and the various closure techniques to develop risk assessment curves for each device. The data show that the figure-of-eight stainless-steel cable and the DSF plate systems are considerably less likely to fail under both lateral distraction and longitudinal shear cyclic loading conditions as compared to the figure-of-eight stainless-steel wire system. Moreover, the figure-of-eight stainless-steel cable system is the most resistant to failure, particularly for high cycle counts. This study in addition to Cohen and Griffin's earlier published biomechanical comparison of the ultimate strength of these same three closure techniques provide extensive experimental evidence regarding the mechanical differences among these three peristernal median

  11. Fatigue testing of three peristernal median sternotomy closure techniques

    Directory of Open Access Journals (Sweden)

    Griffin Lanny V

    2008-09-01

    Full Text Available Abstract Background Failure of a sternotomy closure because of closure system fatigue is a complication that may result in dehiscence and put the individual at risk for serious complications. The purpose of this study was to assess the fatigue performance of three peristernal median sternotomy closure techniques (figure-of-eight stainless-steel wires, figure-of-eight stainless-steel cables, or Pectofix Dynamic Sternal Fixation [DSF] stainless-steel plates in order to quantify the potential risk of fatigue failure of these devices when subject to cyclic loads in physiologically relevant loading directions. Study Design All tests were conducted on polyurethane foam sternal models. A cardiothoracic surgeon divided each sternal model longitudinally and repaired it with a closure device. Tests were performed using a materials testing system that applied cyclic loading in a uniaxial direction until the test model catastrophically broke or data run-out occurred. For each loading direction (lateral distraction and longitudinal shear, five trials of each closure technique were tested. Life data and location of device failure (if present were evaluated. Statistical analysis was performed using regression with life data allowed for correlation between life data and the various closure techniques to develop risk assessment curves for each device. Results The data show that the figure-of-eight stainless-steel cable and the DSF plate systems are considerably less likely to fail under both lateral distraction and longitudinal shear cyclic loading conditions as compared to the figure-of-eight stainless-steel wire system. Moreover, the figure-of-eight stainless-steel cable system is the most resistant to failure, particularly for high cycle counts. Conclusion This study in addition to Cohen and Griffin's earlier published biomechanical comparison of the ultimate strength of these same three closure techniques provide extensive experimental evidence regarding the

  12. 27 CFR 27.62 - Affixing closures.

    Science.gov (United States)

    2010-04-01

    ... OF THE TREASURY LIQUORS IMPORTATION OF DISTILLED SPIRITS, WINES, AND BEER General Requirements Closures for Containers of Distilled Spirits § 27.62 Affixing closures. Closures or other devices on containers of imported distilled spirits having a capacity of 1 gallon (3.785 liters) or less shall be...

  13. 75 FR 29322 - Base Closure and Realignment

    Science.gov (United States)

    2010-05-25

    ... DEPARTMENT OF DEFENSE Office of the Secretary Base Closure and Realignment AGENCY: Office of...)(ii) of the Defense Base Closure and Realignment Act of 1990. It provides a partial list of military installations closing or realigning pursuant to the 2005 Base Closure and Realignment (BRAC) Report. It also...

  14. Long-term cavity closure in non-linear rocks

    Science.gov (United States)

    Cornet, Jan; Dabrowski, Marcin; Schmid, Daniel Walter

    2017-08-01

    The time dependent closure of pressurized cavities in viscous rocks due to far-field loads is a problem encountered in many applications like drilling, cavity abandonment and porosity closure. The non-linear nature of the flow of rocks prevents the use of simple solutions for hole closure and calls for the development of appropriate expressions reproducing all the dependencies observed in nature. An approximate solution is presented for the closure velocity of a pressurized cylindrical cavity in a non-linear viscous medium subjected to a combined pressure and shear stress load in the far field. The embedding medium is treated as homogeneous, isotropic, and incompressible and follows a Carreau viscosity model. We derive analytical solutions for the end-member cases of the pressure and shear loads. The exact analytical solution for pressure loads shows that the closure velocity vR is given by the implicit expression {Δ p}/{2{μ _0D_{II}^*}} = - 1/2B( {v_R^2}/{RD_{II^* + v_R^2}};1/2, - 1/{2n}} ), where Δp is the pressure load, R is the hole radius, B is the incomplete beta function, and μ0, D_{II}^*, n are, respectively, the threshold viscosity, transition rate and stress exponent of the Carreau model. The closure velocity is dominated by the linear mechanism under pressure loads smaller than 1.8{μ _0}D_{II}^* and by the non-linear one under large pressure loads. In the non-linear regime, pressure variations support an increasing part of the load with increasing degree of non-linearity. The decay of the stress perturbation in the non-linear zone varies as r- 2/n where r is the radial distance to the hole. A solution for the maximum closure velocity at the cavity rim vRmax under far-field shear is given: v_{R\\max} = ( {1 + {\\overline {M_s}}^{-1/2})R\\overline D_{II}, where \\overline M_s = (1 +{\\overline{D_{II}}^2} \\big nD_{II}^*^2} ) \\big ( 1 + {\\overline {D_{II}}^2} \\big D{_{II}^*}^2 ) and \\overline D_{II} is the second invariant of the far

  15. The effects of school closures on influenza outbreaks and pandemics: systematic review of simulation studies.

    Science.gov (United States)

    Jackson, Charlotte; Mangtani, Punam; Hawker, Jeremy; Olowokure, Babatunde; Vynnycky, Emilia

    2014-01-01

    School closure is a potential intervention during an influenza pandemic and has been investigated in many modelling studies. To systematically review the effects of school closure on influenza outbreaks as predicted by simulation studies. We searched Medline and Embase for relevant modelling studies published by the end of October 2012, and handsearched key journals. We summarised the predicted effects of school closure on the peak and cumulative attack rates and the duration of the epidemic. We investigated how these predictions depended on the basic reproduction number, the timing and duration of closure and the assumed effects of school closures on contact patterns. School closures were usually predicted to be most effective if they caused large reductions in contact, if transmissibility was low (e.g. a basic reproduction number 90% reductions or even increases under certain assumptions). This partly reflected differences in model assumptions, such as those regarding population contact patterns. Simulation studies suggest that school closure can be a useful control measure during an influenza pandemic, particularly for reducing peak demand on health services. However, it is difficult to accurately quantify the likely benefits. Further studies of the effects of reactive school closures on contact patterns are needed to improve the accuracy of model predictions.

  16. The effects of school closures on influenza outbreaks and pandemics: systematic review of simulation studies.

    Directory of Open Access Journals (Sweden)

    Charlotte Jackson

    Full Text Available School closure is a potential intervention during an influenza pandemic and has been investigated in many modelling studies.To systematically review the effects of school closure on influenza outbreaks as predicted by simulation studies.We searched Medline and Embase for relevant modelling studies published by the end of October 2012, and handsearched key journals. We summarised the predicted effects of school closure on the peak and cumulative attack rates and the duration of the epidemic. We investigated how these predictions depended on the basic reproduction number, the timing and duration of closure and the assumed effects of school closures on contact patterns.School closures were usually predicted to be most effective if they caused large reductions in contact, if transmissibility was low (e.g. a basic reproduction number 90% reductions or even increases under certain assumptions. This partly reflected differences in model assumptions, such as those regarding population contact patterns.Simulation studies suggest that school closure can be a useful control measure during an influenza pandemic, particularly for reducing peak demand on health services. However, it is difficult to accurately quantify the likely benefits. Further studies of the effects of reactive school closures on contact patterns are needed to improve the accuracy of model predictions.

  17. Combination therapy accelerates diabetic wound closure.

    Directory of Open Access Journals (Sweden)

    Robert J Allen

    Full Text Available Non-healing foot ulcers are the most common cause of non-traumatic amputation and hospitalization amongst diabetics in the developed world. Impaired wound neovascularization perpetuates a cycle of dysfunctional tissue repair and regeneration. Evidence implicates defective mobilization of marrow-derived progenitor cells (PCs as a fundamental cause of impaired diabetic neovascularization. Currently, there are no FDA-approved therapies to address this defect. Here we report an endogenous PC strategy to improve diabetic wound neovascularization and closure through a combination therapy of AMD3100, which mobilizes marrow-derived PCs by competitively binding to the cell surface CXCR4 receptor, and PDGF-BB, which is a protein known to enhance cell growth, progenitor cell migration and angiogenesis.Wounded mice were assigned to 1 of 5 experimental arms (n = 8/arm: saline treated wild-type, saline treated diabetic, AMD3100 treated diabetic, PDGF-BB treated diabetic, and AMD3100/PDGF-BB treated diabetic. Circulating PC number and wound vascularity were analyzed for each group (n = 8/group. Cellular function was assessed in the presence of AMD3100. Using a validated preclinical model of type II diabetic wound healing, we show that AMD3100 therapy (10 mg/kg; i.p. daily alone can rescue diabetes-specific defects in PC mobilization, but cannot restore normal wound neovascularization. Through further investigation, we demonstrate an acquired trafficking-defect within AMD3100-treated diabetic PCs that can be rescued by PDGF-BB (2 μg; topical supplementation within the wound environment. Finally, we determine that combination therapy restores diabetic wound neovascularization and accelerates time to wound closure by 40%.Combination AMD3100 and PDGF-BB therapy synergistically improves BM PC mobilization and trafficking, resulting in significantly improved diabetic wound closure and neovascularization. The success of this endogenous, cell-based strategy to

  18. Nursing home closures: effects on capacity and reasons for closure.

    Science.gov (United States)

    Netten, Ann; Darton, Robin; Williams, Jacquetta

    2003-05-01

    to identify the rate of closure of nursing homes for older people, the types of homes closing and the reasons for closure. mixed method study including a census and telephone survey of registration and inspection units and interviews with independent providers. 81 of 96 health authority and joint registration and inspection unit managers in England completed the census and 39 managers participated in a further telephone survey. Twenty-five independent providers were interviewed. closures resulted in a net loss of 6% of nursing homes and 4.9% of nursing places during 2000-2001. Smaller homes were more likely to close and were increasingly seen as unviable. The majority of closed homes were reported to have provided good quality care. Shortages of nursing staff were of widespread concern. The dominant combination of factors identified by providers was low fees and concerns about the cost implications of the new care standards. Changes in demand were reflected in the placement of high dependency residents in residential rather than nursing homes. in the absence of policy interventions capacity will continue to reduce, with smaller homes most likely to disappear. There is an urgent need to address the supply and efficient use of nursing staff skills in care homes. While fee levels are the primary concern the effect of the proposed care standards was clearly having an effect. Even with subsequent amendment to these standards, unless authorities use capacity funding to raise fees and improve expectations, providers are likely to continue to exit the market.

  19. Innovation Processes and Closure

    DEFF Research Database (Denmark)

    Darsø, Lotte; Austin, Robert

    2009-01-01

    Artiklen beskriver, diskuterer og illustrerer en lang række forskellige innovationsprocesmodeller med fokus på hvordan (og hvornår) innovative teams håndterer at stoppe processen. Sommetider er der tale om forceret lukning fx pga deadlines eller andet, andre gange sker der en tydelig krystalliser...... krystallisering af et koncept. Der peges også på nye typer af modeller, hvor udviklingsprocessen holdes åben, fordi produktet aldrig bliver "færdigt". Endelig sammenholdes innovationsprocessen med kunstneriske og kreative processer....

  20. Stomatal closure by ultraviolet radiation

    International Nuclear Information System (INIS)

    Negash, L.; Björn, L.O.

    1986-01-01

    The effect of ultraviolet radiation (UV) (255–325 nm) on stomatal closure was investigated on tef [Eragrostis tef (Zucc) Trotter] in the presence of white light (ca 50 ·mol m −2 s −1 ). The action spectrum showed that UV (ca 2 ·mol m −2 s −1 , half band width about 10 nm) of 285 nm or shorter wavelengths was very efficient in causing stomatal closure. The effectiveness decreased sharply towards longer wavelengths. Radiation of 313 nm or longer wavelengths was practically without effect. Increasing UV intensity increased stomatal resistance. When stronger white light (5 to 9 times stronger than the one used during irradiation) was administered, stomates re-opened rapidly irrespective of whether the UV was on or off, although a subsequent gradual closing tendency was observed when the UV was on. (author)

  1. 304 Concretion Facility Closure Plan

    International Nuclear Information System (INIS)

    1991-10-01

    The Hanford Site, located northwest of Richland, Washington, houses reactors, chemical-separation systems, and related facilities used for the production of special nuclear materials. The 300 Area of the Hanford Site contains reactor fuel manufacturing facilities and several research and development laboratories. Recyclable scrap uranium with Zircaloy-2 and copper silicon allo , uranium-titanium alloy, beryllium/Zircaloy-2 alloy, and Zircaloy-2 chips and fines were secured in concrete billets (7.5-gal containers) in the 304 Concretion Facility (304 Facility), located in the 300 Area. The beryllium/Zircaloy-2 alloy and Zircaloy-2 chips and fines are designated as low-level radioactive mixed waste (LLRMW) with the characteristic of ignitability. The concretion process reduced the ignitability of the fines and chips for safe storage and shipment. This process has been discontinued and the 304 Concretion Facility is now undergoing closure as defined in the Resource Conservation and Recovery Act of 1976 (RCRA) and the Washington Administrative Code (WAC) Dangerous Waste Regulations, WAC 173-303-040 (Ecology 1991). This closure plan presents a description of the facility, the history of materials and wastes managed, and the procedures that will be followed to close the 304 Facility. The strategy for closure of the 304 Facility is presented in Section 6.0

  2. Ocular biometry in angle closure.

    Science.gov (United States)

    Razeghinejad, Mohammad Reza; Banifatemi, Mohammad

    2013-01-01

    To compare ocular biometric parameters in primary angle closure suspects (PACS), primary angle closure glaucoma (PACG) and acute primary angle closure (APAC). This cross-sectional study was performed on 113 patients including 33 cases of PACS, 45 patients with PACG and 35 subjects with APAC. Central corneal thickness (CCT), axial length (AL), anterior chamber depth (ACD) and lens thickness (LT) were measured with an ultrasonic biometer. Lens-axial length factor (LAF), relative lens position, corrected ACD (CACD) and corrected lens position were calculated. The parameters were measured bilaterally but only data from the right eyes were compared. In the APAC group, biometric parameters were also compared between affected and unaffected fellow eyes. Logistic regression analysis was performed to identify risk factors. No statistically significant difference was observed in biometric parameters between PACS and PACG eyes, or between affected and fellow eyes in the APAC group (P>0.05 for all comparisons). However, eyes with APAC had thicker cornea (P=0.001), thicker lens (PAPAC. In the APAC group, LAF (PAPAC.

  3. Repository Closure and Sealing Approach

    International Nuclear Information System (INIS)

    A.T. Watkins

    2000-01-01

    The scope of this analysis will be to develop the conceptual design of the closure seals and their locations in the Subsurface Facilities. The design will be based on the recently established program requirements for transitioning to the Site Recommendation (SR) design as outlined by ''Approach to Implementing the Site Recommendation Baseline'' (Stroupe 2000) and the ''Monitored Geologic Repository Project Description Document'' (CRWMS M andO 1999b). The objective of this analysis will be to assist in providing a description for the Subsurface Facilities System Description Document, Section 2 and finally to document any conclusions reached in order to contribute and provide support to the SR. This analysis is at a conceptual level and is considered adequate to support the SR design. The final closure barriers and seals for the ventilation shafts, and the north and south ramps will require these openings to be permanently sealed to limit excessive air and water inflows and prevent human intrusion. The major tasks identified with closure in this analysis are: (1) Developing the overall subsurface seal layout and identifying design and operational interfaces for the Subsurface Facilities. (2) Summarizing the general site conditions and general rock characteristic with respect to seal location and describing the seal selected. (3) Identify seal construction materials, methodology of construction and strategic locations including design of the seal and plugs. (4) Discussing methods to prevent human intrusion

  4. Closure of open wellbores in creeping salt sheets

    NARCIS (Netherlands)

    Weijermars, R.; Jackson, M.P.A.; Van Harmelen, A.

    2013-01-01

    Safe exploration and production of pre-salt (or subsalt) hydrocarbons require that drilling operations be optimized. We introduce analytical models of wellbore closure, accounting for variations in both the wellbore net pressure and far-field flow rate of an autochthonous or allochthonous salt sheet

  5. Distraction osteogenesis for cleft palate closure: A finite element analysis

    Directory of Open Access Journals (Sweden)

    Majid Ghasemianpour

    2014-01-01

    Full Text Available Background: Current methods of closure of the cleft palate result in the formation of scars and impairment of growth. Distraction osteogenesis (DO might be an effective means to repair or at least reduce the size of wide clefts. This study investigates the biomechanical aspects of this process. Materials and Methods: DO simulation was applied to reduce the size of a unilateral hard palate cleft on a three-dimensional (3D model of the maxilla. For the position of osteotomy lines, two different models were assumed, with the osteotomy line on the affected side in model A and on the intact side in model B. In each model, DO screws were placed on two different positions, anteriorly (models A1 and B1 and posteriorly (models A2 and B2. Displacement pattern of the bony island in each of the four models, reaction forces at DO locations, and von Mises stress were estimated. Mesh generation and data processing were carried out in the 3D finite element analysis package (ABAQUS V6.7-1; Simulia Corp., Providence, RI, USA. Results: In model B2, the island moved almost evenly, assuring a more complete closure of the cleft. The most uniform stress distribution was found in model B1. Conclusion: The results suggest that the best positions for the DO screw and the osteotomy line for closure of the cleft palate are posteriorly and on the intact side, respectively.

  6. Distraction osteogenesis for cleft palate closure: A finite element analysis.

    Science.gov (United States)

    Ghasemianpour, Majid; Ehsani, Sara; Tahmasbi, Soodeh; Bayat, Mohammad; Ghorbanpour, Maedeh; Safavi, Seyed Mohammadreza; Mirhashemi, Fatemeh Sadat

    2014-01-01

    Current methods of closure of the cleft palate result in the formation of scars and impairment of growth. Distraction osteogenesis (DO) might be an effective means to repair or at least reduce the size of wide clefts. This study investigates the biomechanical aspects of this process. DO simulation was applied to reduce the size of a unilateral hard palate cleft on a three-dimensional (3D) model of the maxilla. For the position of osteotomy lines, two different models were assumed, with the osteotomy line on the affected side in model A and on the intact side in model B. In each model, DO screws were placed on two different positions, anteriorly (models A1 and B1) and posteriorly (models A2 and B2). Displacement pattern of the bony island in each of the four models, reaction forces at DO locations, and von Mises stress were estimated. Mesh generation and data processing were carried out in the 3D finite element analysis package (ABAQUS V6.7-1; Simulia Corp., Providence, RI, USA). In model B2, the island moved almost evenly, assuring a more complete closure of the cleft. The most uniform stress distribution was found in model B1. The results suggest that the best positions for the DO screw and the osteotomy line for closure of the cleft palate are posteriorly and on the intact side, respectively.

  7. Angle closure glaucoma secondary to psychotropic medications

    Directory of Open Access Journals (Sweden)

    John Ross Rocke

    2017-07-01

    Full Text Available Background Psychotropic medications are commonly associated anticholinergic side-effects. In susceptible patients, this can result in angle closure induced permanent loss of vision Aims To review the mechanism of angle closure and which psychotropics are most likely to precipitate this complication. Methods Literature review surrounding the mechanism of angle closure and pharmacology of various psychotropics Results Mydriasis, forward-displacement of the lens-iris diaphragm and ciliary body swelling are the mechanisms by which angle closure occurs. Anticholinergic side effects of psychotropic medications are most implicated in causing this. Conclusion Screening patients for risk factors of angle closure and either having them formally assessed or choosing psychotropics with minimal anticholinergic effects may avoid inducing angle closure.

  8. Primary closure of equine laryngotomy incisions

    DEFF Research Database (Denmark)

    Lindegaard, C.; Karlsson, L.; Ekstrøm, Claus Thorn

    2016-01-01

    The objective was to report healing characteristics and complications after primary closure of equine laryngotomies and analyse factors potentially associated with complications. This retrospective case series of the medical records of horses (n = 180) undergoing laryngoplasty and laryngotomy...... after primary closure of equine laryngotomy incisions are infrequent and considered of minimal severity and can be performed safely when paying careful attention to the closure of the cricothyroid membrane....

  9. Storage shaft definitive closure plug and method

    International Nuclear Information System (INIS)

    Dardaine, M.

    1992-01-01

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

  10. 2727-S Nonradioactive Dangerous Waste Storage Facility clean closure evaluation report

    Energy Technology Data Exchange (ETDEWEB)

    Luke, S.N.

    1994-07-14

    This report presents the analytical results of 2727-S NRDWS facility closure verification soil sampling and compares these results to clean closure criteria. The results of this comparison will determine if clean closure of the unit is regulatorily achievable. This report also serves to notify regulators that concentrations of some analytes at the site exceed sitewide background threshold levels (DOE-RL 1993b) and/or the limits of quantitation (LOQ). This report also presents a Model Toxics Control Act Cleanup (MTCA) (WAC 173-340) regulation health-based closure standard under which the unit can clean close in lieu of closure to background levels or LOQ in accordance with WAC 173-303-610. The health-based clean closure standard will be closure to MTCA Method B residential cleanup levels. This report reconciles all analyte concentrations reported above background or LOQ to this health-based cleanup standard. Regulator acceptance of the findings presented in this report will qualify the TSD unit for clean closure in accordance with WAC 173-303-610 without further TSD unit soil sampling, or soil removal and/or decontamination. Nondetected analytes require no further evaluation.

  11. Economic Evaluation of Individual School Closure Strategies: The Hong Kong 2009 H1N1 Pandemic.

    Directory of Open Access Journals (Sweden)

    Zoie Shui-Yee Wong

    Full Text Available School closures as a means of containing the spread of disease have received considerable attention from the public health community. Although they have been implemented during previous pandemics, the epidemiological and economic effects of the closure of individual schools remain unclear.This study used data from the 2009 H1N1 pandemic in Hong Kong to develop a simulation model of an influenza pandemic with a localised population structure to provide scientific justifications for and economic evaluations of individual-level school closure strategies.The estimated cost of the study's baseline scenario was USD330 million. We found that the individual school closure strategies that involved all types of schools and those that used a lower threshold to trigger school closures had the best performance. The best scenario resulted in an 80% decrease in the number of cases (i.e., prevention of about 830,000 cases, and the cost per case prevented by this intervention was USD1,145; thus, the total cost was USD1.28 billion.This study predicts the effects of individual school closure strategies on the 2009 H1N1 pandemic in Hong Kong. Further research could determine optimal strategies that combine various system-wide and district-wide school closures with individual school triggers across types of schools. The effects of different closure triggers at different phases of a pandemic should also be examined.

  12. Ocular Biometry in Angle Closure

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Razeghinejad

    2013-01-01

    Full Text Available Purpose: To compare ocular biometric parameters in primary angle closure suspects (PACS, primary angle closure glaucoma (PACG and acute primary angle closure (APAC. Methods: This cross-sectional study was performed on 113 patients including 33 cases of PACS, 45 patients with PACG and 35 subjects with APAC. Central corneal thickness (CCT, axial length (AL, anterior chamber depth (ACD and lens thickness (LT were measured with an ultrasonic biometer. Lens-axial length factor (LAF, relative lens position, corrected ACD (CACD and corrected lens position were calculated. The parameters were measured bilaterally but only data from the right eyes were compared. In the APAC group, biometric parameters were also compared between affected and unaffected fellow eyes. Logistic regression analysis was performed to identify risk factors. Results: No statistically significant difference was observed in biometric parameters between PACS and PACG eyes, or between affected and fellow eyes in the APAC group (P>0.05 for all comparisons. However, eyes with APAC had thicker cornea (P=0.001, thicker lens (P<0.0001, shallower ACD (P=0.009, shallower CACD (P=0.003 and larger LAF (P<0.0001. Based on ROC curve analysis, lower ACD, and larger LT, LAF and CCT values were associated with APAC. In the APAC group, LAF (P<0.0001 and CCT (P=0.001 were significant risk factors. Conclusion: This study revealed no significant difference in biometric characteristics in eyes with PACS and PACG. However, larger LAF and CCT were predictive of APAC.

  13. 100-D Ponds closure plan. Revision 1

    International Nuclear Information System (INIS)

    Petersen, S.W.

    1997-09-01

    The 100-D Ponds is a Treatment, Storage, and Disposal (TSD) unit on the Hanford Facility that received both dangerous and nonregulated waste. This Closure Plan (Rev. 1) for the 100-D Ponds TSD unit consists of a RCRA Part A Dangerous Waste Permit Application (Rev. 3), a RCRA Closure Plan, and supporting information contained in the appendices to the plan. The closure plan consists of eight chapters containing facility description, process information, waste characteristics, and groundwater monitoring data. There are also chapters containing the closure strategy and performance standards. The strategy for the closure of the 100-D Ponds TSD unit is clean closure. Appendices A and B of the closure plan demonstrate that soil and groundwater beneath 100-D Ponds are below cleanup limits. All dangerous wastes or dangerous waste constituents or residues associated with the operation of the ponds have been removed, therefore, human health and the environment are protected. Discharges to the 100-D Ponds, which are located in the 100-DR-1 operable unit, were discontinued in June 1994. Contaminated sediment was removed from the ponds in August 1996. Subsequent sampling and analysis demonstrated that there is no contamination remaining in the ponds, therefore, this closure plan is a demonstration of clean closure

  14. 100-D Ponds closure plan. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Petersen, S.W.

    1997-09-01

    The 100-D Ponds is a Treatment, Storage, and Disposal (TSD) unit on the Hanford Facility that received both dangerous and nonregulated waste. This Closure Plan (Rev. 1) for the 100-D Ponds TSD unit consists of a RCRA Part A Dangerous Waste Permit Application (Rev. 3), a RCRA Closure Plan, and supporting information contained in the appendices to the plan. The closure plan consists of eight chapters containing facility description, process information, waste characteristics, and groundwater monitoring data. There are also chapters containing the closure strategy and performance standards. The strategy for the closure of the 100-D Ponds TSD unit is clean closure. Appendices A and B of the closure plan demonstrate that soil and groundwater beneath 100-D Ponds are below cleanup limits. All dangerous wastes or dangerous waste constituents or residues associated with the operation of the ponds have been removed, therefore, human health and the environment are protected. Discharges to the 100-D Ponds, which are located in the 100-DR-1 operable unit, were discontinued in June 1994. Contaminated sediment was removed from the ponds in August 1996. Subsequent sampling and analysis demonstrated that there is no contamination remaining in the ponds, therefore, this closure plan is a demonstration of clean closure.

  15. Parameterization of the 3-PG model for Pinus elliottii stands using alternative methods to estimate fertility rating, biomass partitioning and canopy closure

    Science.gov (United States)

    Carlos A. Gonzalez-Benecke; Eric J. Jokela; Wendell P. Cropper; Rosvel Bracho; Daniel J. Leduc

    2014-01-01

    The forest simulation model, 3-PG, has been widely applied as a useful tool for predicting growth of forest species in many countries. The model has the capability to estimate the effects of management, climate and site characteristics on many stand attributes using easily available data. Currently, there is an increasing interest in estimating biomass and assessing...

  16. Leaf-on canopy closure in broadleaf deciduous forests predicted during winter

    Science.gov (United States)

    Twedt, Daniel J.; Ayala, Andrea J.; Shickel, Madeline R.

    2015-01-01

    Forest canopy influences light transmittance, which in turn affects tree regeneration and survival, thereby having an impact on forest composition and habitat conditions for wildlife. Because leaf area is the primary impediment to light penetration, quantitative estimates of canopy closure are normally made during summer. Studies of forest structure and wildlife habitat that occur during winter, when deciduous trees have shed their leaves, may inaccurately estimate canopy closure. We estimated percent canopy closure during both summer (leaf-on) and winter (leaf-off) in broadleaf deciduous forests in Mississippi and Louisiana using gap light analysis of hemispherical photographs that were obtained during repeat visits to the same locations within bottomland and mesic upland hardwood forests and hardwood plantation forests. We used mixed-model linear regression to predict leaf-on canopy closure from measurements of leaf-off canopy closure, basal area, stem density, and tree height. Competing predictive models all included leaf-off canopy closure (relative importance = 0.93), whereas basal area and stem density, more traditional predictors of canopy closure, had relative model importance of ≤ 0.51.

  17. Accelerating cleanup: Paths to closure

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, C.

    1998-06-30

    This document was previously referred to as the Draft 2006 Plan. As part of the DOE`s national strategy, the Richland Operations Office`s Paths to Closure summarizes an integrated path forward for environmental cleanup at the Hanford Site. The Hanford Site underwent a concerted effort between 1994 and 1996 to accelerate the cleanup of the Site. These efforts are reflected in the current Site Baseline. This document describes the current Site Baseline and suggests strategies for further improvements in scope, schedule and cost. The Environmental Management program decided to change the name of the draft strategy and the document describing it in response to a series of stakeholder concerns, including the practicality of achieving widespread cleanup by 2006. Also, EM was concerned that calling the document a plan could be misconstrued to be a proposal by DOE or a decision-making document. The change in name, however, does not diminish the 2006 vision. To that end, Paths to Closure retains a focus on 2006, which serves as a point in time around which objectives and goals are established.

  18. Review on improved seismic imaging with closure phase

    KAUST Repository

    Schuster, Gerard T.

    2014-08-13

    The timing and amplitudes of arrivals recorded in seismic traces are influenced by velocity variations all along the associated raypaths. Consequently, velocity errors far from the target can lead to blurred imaging of the target body. To partly remedy this problem, we comprehensively reviewed inverting differential traveltimes that satisfied the closure-phase condition. The result is that the source and receiver statics are completely eliminated in the data and velocities far from the target do not need to be known. We successfully used the phase closure equation for traveltime tomography, refraction statics, migration, refraction tomography, and earthquake location, all of which demonstrated the higher resolution achievable by processing data with differential traveltimes rather than absolute traveltimes. More generally, the stationary version of the closure-phase equation is equivalent to Fermat’s principle and can be derived from the equations of seismic interferometry. In summary, the general closure-phase equation is the mathematical foundation for approximately redatuming sources and/or receivers to the target of interest without the need to accurately know the statics or the velocity model away from the target.

  19. Sustainable closure of construction materials quarries in Cuba

    Directory of Open Access Journals (Sweden)

    Julio Montero-Matos

    2017-10-01

    Full Text Available The inclusion of effective mine closure plans in the exploitation project is the way to compensate for the harmful effect of this activity. Based on a diagnosis carried out in 11 sites in operation, belonging to the company Canteras, a methodology was designed with a systemic and integral approach that consists of five stages and allows the execution of quarry closures in a sustainable manner. The Delphi method was applied to select the criteria that directly affect the sustainable closure of quarries in such a way that it considers the essential postulates of the Cuban Economic Model (MEC. The proposed methodology represents a contribution to the planning and design of the mining closure in Cuban non-metallic deposits to guarantee the reduction of the environmental impacts caused during its operation and the reduction, to the lesser extent possible, of negative socio-economic effects for the workers and the community located in the area of influence of the quarries. Currently applied in the quarry of San José, in Mayabeque province.

  20. Development of an Insight Model for Post-closure Radiological Risks from the Disposal of High-level Waste and Spent Fuel

    Science.gov (United States)

    Kelly, M.; Carter, A.; Bailey, L.; Wellstead, M.

    2012-04-01

    Geological disposal is the UK policy for the long-term management of higher activity radioactive wastes. The Radioactive Waste Management Directorate (RWMD) of the Nuclear Decommissioning Authority (NDA) has been given the responsibility for implementing geological disposal in the UK. The approach adopted for building confidence in long-term safety of the GDF is to use multiple barriers to isolate and contain the wastes. NDA-RWMD proposes to develop a safety case based on varied and different lines of reasoning, including both quantitative aspects and qualitative safety arguments. This paper describes the development of a simplified model for high-level waste (HLW) and spent fuel (SF). Assessments of HLW and SF disposals need to reflect a number of physical and chemical processes that govern the release and transport of the disposed wastes. Physical processes include container failure, release of radionuclides from the wasteform, diffusion through bentonite barriers and transport in fractured rock. Chemical processes include solubility limitation and sorption. HLW and SF assessments are generally based on numerical models of these processes, implemented in software tools such as GoldSim. The results of such assessments can be complex to understand, especially in situations where no single release or transport process is dominant. A simplified model of the release and transport of radionuclides for disposals of HLW and SF has been developed. The objectives of the model are to identify the key physical and chemical processes that govern radiological risk, and to enable numerical estimates of risk (and other intermediate quantities) to be made. The model is based on the notion that the properties of the time-dependent model outputs can be characterised in terms of "moments". The moments are easy to compute since they are related in a simple way to the Laplace transforms of the functions under consideration. The Laplace transform method is a standard technique for

  1. Discrete objects, splitting closure and connectedness | Castellini ...

    African Journals Online (AJOL)

    Notions of discrete and indiscrete classes with respect to a closure operator are introduced and studied. These notions are strongly related to splitting and cosplitting closure operators. By linking the above concepts, two Galois connections arise whose composition provides a third Galois connection that can be used as a ...

  2. Hanford Patrol Academy Demolition Sites Closure Plan

    International Nuclear Information System (INIS)

    1992-11-01

    From 1975 to 1991 the Hanford Patrol Academy Demolition Sites (HPADS) were used for demolition events. These demolition events were a form of thermal treatment for spent or abandoned chemical waste. Because the HPADS will no longer be used for this thermal activity, the sites will be closed. Closure will be conducted pursuant to the requirements of the Washington State Department of Ecology (Ecology) Dangerous Waste Regulations, Washington Administrative Code (WAC) 173-303-610 and 40 CFR 270.1. Closure also will satisfy closure requirements of WAC 173-303-680 and for the thermal treatment closure requirements of 40 CFR 265.381. This closure plan presents a description of the HPADS, the history of the waste treated, and the approach that will be followed to close the HPADS. Because dangerous waste does not include the source, special nuclear, and by-product material components of mixed waste, radionuclides are not within the scope of WAC 173-303 or of this closure plan. The information on radionuclides is provided only for general knowledge where appropriate. Only dangerous constituents derived from HPADS operations will be addressed in this closure plan in accordance with WAC 173-303-610(2)(b)(i). The HPADS are actually two distinct soil closure areas within the Hanford Patrol Academy training area

  3. Spontaneous closure of traumatic tympanic membrane perforations

    DEFF Research Database (Denmark)

    Jellinge, Marlene Ersgaard; Kristensen, S.; Larsen, K

    2015-01-01

    BACKGROUND: The treatment of traumatic tympanic membrane perforations varies in different investigations, ranging from observation to early surgical repair. The present study aimed to focus on the closure rate and the closure time in a group of patients treated with a watchful waiting policy. MET...

  4. Acute angle closure glaucoma following ileostomy surgery

    Directory of Open Access Journals (Sweden)

    Mariana Meirelles Lopes

    2015-02-01

    Full Text Available Angle-closure glaucoma can be induced by drugs that may cause pupillary dilatation. We report a case of a patient that developed bilateral angle closure glaucoma after an ileostomy surgery because of systemic atropine injection. This case report highlights the importance of a fast ophthalmologic evaluation in diseases with ocular involvement in order to make accurate diagnoses and appropriate treatments.

  5. Energy balance closure at FLUXNET sites

    NARCIS (Netherlands)

    Wilson, K.B.; Goldstein, A.; Falge, E.; Aubinet, M.; Baldocchi, D.D.; Berbigier, P.; Bernhofer, C.; Ceulemans, R.; Dolman, A.J.; Field, C.; Grelle, A.; Ibrom, A.; Law, B.E.; Kowalski, A.; Meyers, T.; Monchieff, J.; Monson, R.; Oechel, W.; Tenhunen, J.; Valentini, R.; Verma, S.

    2002-01-01

    A comprehensive evaluation of energy balance closure is performed across 22 sites and 50 site-years in FLUXNET, a network of eddy covariance sites measuring long-term carbon and energy fluxes in contrasting ecosystems and climates. Energy balance closure was evaluated by statistical regression of

  6. Triadic closure dynamics drives scaling laws in social multiplex networks

    International Nuclear Information System (INIS)

    Klimek, Peter; Thurner, Stefan

    2013-01-01

    Social networks exhibit scaling laws for several structural characteristics, such as degree distribution, scaling of the attachment kernel and clustering coefficients as a function of node degree. A detailed understanding if and how these scaling laws are inter-related is missing so far, let alone whether they can be understood through a common, dynamical principle. We propose a simple model for stationary network formation and show that the three mentioned scaling relations follow as natural consequences of triadic closure. The validity of the model is tested on multiplex data from a well-studied massive multiplayer online game. We find that the three scaling exponents observed in the multiplex data for the friendship, communication and trading networks can simultaneously be explained by the model. These results suggest that triadic closure could be identified as one of the fundamental dynamical principles in social multiplex network formation. (paper)

  7. Watertight dural closure! An in vitro study to explore the myth

    Directory of Open Access Journals (Sweden)

    Sudipkumar Sengupta

    2013-01-01

    Full Text Available Aim: The watertight closure of the dura mater is fundamental to intracranial supratentorial procedures in neurosurgery. Controversies exist claiming the superiority of one closure technique over another. But is ′Water-tight′ dural closure really achievable ? An in vitro study system was developed to test the pressures at which dural incisions, closed with sutures, leaked. Materials and Methods: Bovine dura was secured to the lower end of an open ended calibrated plastic cylinder. Multiple interrupted stitches were applied over a two 2 cm length of the dura without any incision. Similarly a 2 cm incision was made and closed with interrupted and continuous stitches. Cylinder was filled with colored saline gradually. Height of the water column at which sutured dura leaked was recorded. The tests were conducted with the dura both in lax and tense conditions. Inlay closure technique was also tested on the same model using a dural substitute. Results: Even without an incision, needle puncture sites over a dura, leak, at a very low hydrostatic pressure (30 < mm of H2O, though a continuous interlocking suture performs slightly better than an interrupted suture technique. If the needle puncture sites are closed with glue, both the suture techniques can achieve a watertight closure against a hydrostatic pressure of 240 mm of H2O. Conclusion : In the experimental model described, ′Water-tight′ dural closure appears to be impossible with suture closure of a dural defect.

  8. Nursing home closures and quality of care.

    Science.gov (United States)

    Castle, Nicholas G

    2005-02-01

    The purpose of this research is to examine the relationship between quality of care in nursing homes and their likelihood of closure. We hypothesize that lower-quality facilities will be more likely to close than higher-quality facilities. Using the rates of physical restraint use, urethral catheterization, contractures, pressure ulcers, and psychotropic medication use as quality measures from approximately 12,000 facilities from 1992 to 1998, the author examine cross-sectional and change score relationships between these measures and a nursing home's likelihood of closure. The descriptive analysis shows that 621 nursing homes closed in this time period, and the results for physical restraint use were robust in their positive association with closures in most analyses lending some support for this study's hypothesis. However, overall, the author concludes that nursing facility closures are relatively rare events. And the likelihood of closure, even for poor-quality facilities, is low.

  9. Closure of Microcosm for refurbishment

    CERN Multimedia

    2014-01-01

    Since 1994, the Microcosm exhibition has given the opportunity to visitors of all ages and backgrounds to have a first glimpse into the secrets of physics.   To ensure that Microcosm can continue fulfilling its educational aims at the same level of quality for many years to come, it is closing for renovation work on 8 December 2014 and is expected to reopen during Summer 2015. During the closure, the “Fun with Physics” workshop will not take place, but the Universe of Particles exhibition in the Globe and the Passport to the Big Bang circuit will remain accessible to the public, free of charge and with no need to book in advance.  Guided tours of CERN are also available (advance booking required via this page).

  10. Physical simulations of cavity closure in a creeping material

    Energy Technology Data Exchange (ETDEWEB)

    Sutherland, H.J.; Preece, D.S.

    1985-09-01

    The finite element method has been used extensively to predict the creep closure of underground petroleum storage cavities in rock salt. Even though the numerical modeling requires many simplifying assumptions, the predictions have generally correlated with field data from instrumented wellheads, however, the field data are rather limited. To gain an insight into the behavior of three-dimensional arrays of cavities and to obtain a larger data base for the verification of analytical simulations of creep closure, a series of six centrifuge simulation experiments were performed using a cylindrical block of modeling clay, a creeping material. Three of the simulations were conducted with single, centerline cavities, and three were conducted with a symmetric array of three cavities surrounding a central cavity. The models were subjected to body force loading using a centrifuge. For the single cavity experiments, the models were tested at accelerations of 100, 125 and 150 g's for 2 hours. For the multi-cavity experiments, the simulations were conducted at 100 g's for 3.25 hours. The results are analyzed using dimensional analyses. The analyses illustrate that the centrifuge simulations yield self-consistent simulations of the creep closure of fluid-filled cavities and that the interaction of three-dimensional cavity layouts can be investigated using this technique.

  11. Corporate strategy and viable future land use: Planning for closure from the outset of mining

    International Nuclear Information System (INIS)

    Warhurst, A.

    2000-01-01

    This paper provides an overview of the environmental impact of mining on viable future land use and underlines the imperative of improved environmental management and closure planning. It argues that pollution prevention, through planning for closure, can lead to cost-effective strategies for sustainable minerals development and viable future land use. This seems to be most true for greenfield sites since, generally, the earlier closure planning and pollution prevention is built into a project, the more cost-effective and environmentally benign closure will be. Further, for greenfield sites, pollution prevention techniques can be employed from the outset, at the stages of exploration and mine development, and then monitored and improved through the operation stage to closure, and can be kept in place to manage future land use. The paper discusses how global changes in the industry, following the liberalisation of investment regimes, and mergers and strategic alliances between key firms, has, by virtue of the diffusion of new technology, led to further opportunities to prevent pollution and optimise future land use through planning for closure from the outset. The objectives and components of closure plans are also reviewed as the paper draws on case studies to highlight some of the possible constraints and challenges to pollution prevention that may be faced at the level of both public policy and corporate strategy. The article concludes by suggesting a forward-looking approach to integrated environmental management and viable future land-use planning based on a dynamic model for environmental management. (author)

  12. Factors associated with increasing nursing home closures.

    Science.gov (United States)

    Castle, Nicholas G; Engberg, John; Lave, Judith; Fisher, Andrew

    2009-06-01

    We determine the rate of nursing home closures for 7 years (1999-2005) and examine internal (e.g., quality), organizational (e.g., chain membership), and external (e.g., competition) factors associated with these closures. The names of the closed facilities and dates of closure from state regulators in all 50 states were obtained. This information was linked to the Online Survey, Certification, and Reporting data, which contains information on internal, organizational, and market factors for almost all nursing homes in the United States. One thousand seven hundred and eighty-nine facilities closed over this time period (1999-2005). The average annual rate of closure was about 2 percent of facilities, but the rate of closure was found to be increasing. Nursing homes with higher rates of deficiency citations, hospital-based facilities, chain members, small bed size, and facilities located in markets with high levels of competition were more likely to close. High Medicaid occupancy rates were associated with a high likelihood of closure, especially for facilities with low Medicaid reimbursement rates. As states actively debate about how to redistribute long-term care services/dollars, our findings show that they should be cognizant of the potential these decisions have for facilitating nursing home closures.

  13. Complications of bladder closure in cloacal exstrophy: Do osteotomy and reoperative closure factor in?

    Science.gov (United States)

    Friedlander, Daniel A; Di Carlo, Heather N; Sponseller, Paul D; Gearhart, John P

    2017-11-01

    The aims of surgical management in cloacal exstrophy (CE) have shifted to optimizing outcomes and quality of life while minimizing morbidity. This report reviews the single-institution experience of complications of bladder closure in CE. Patients with CE were identified from a prospectively-maintained bladder exstrophy-epispadias complex database. Operative and follow-up data were analyzed to compare complications and failure rates of bladder closure between closures performed with and without osteotomy and primary versus reoperative closures. Of 134 patients followed with CE, 112 met inclusion criteria. Median follow-up time was 3.05years. The failure rate among 112 primary closures (mean age 8.4months) was 31.3% versus 51.9% in reoperative closures (mean age 19.7months) (p=0.044). Complication rate among primary and reoperative closures was 17.9% and 33.3%, respectively (p=0.076). For closures with pelvic osteotomy, failure rate was 24.0% versus 45.9% without osteotomy (p=0.018). Among primary closures with osteotomy, the complication rate was 21.3% versus 10.8% without osteotomy (p=0.171). Complications of bladder closure are common in CE. Pelvic osteotomy reduces failure rates without a significant rise in complications, which are often minor. There was no statistically significant difference in complication rates between reoperative and primary closures. However, reoperative closures were more likely to fail, emphasizing the importance of a successful primary closure. II: retrospective study. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. AX Tank farm closure settlement estimates and soil testing; TOPICAL

    International Nuclear Information System (INIS)

    BECKER, D.L.

    1999-01-01

    This study provides a conservative three-dimensional settlement study of the AX Tank Farm closure with fill materials and a surface barrier. The finite element settlement model constructed included the interaction of four tanks and the surface barrier with the site soil and bedrock. Also addressed are current soil testing techniques suitable for the site soil with recommendations applicable to the AX Tank Farm and the planned cone penetration testing

  15. Closure technique after carotid endarterectomy influences local hemodynamics.

    Science.gov (United States)

    Harrison, Gareth J; How, Thien V; Poole, Robert J; Brennan, John A; Naik, Jagjeeth B; Vallabhaneni, S Rao; Fisher, Robert K

    2014-08-01

    Meta-analysis supports patch angioplasty after carotid endarterectomy (CEA); however, studies indicate considerable variation in practice. The hemodynamic effect of a patch is unclear and this study attempted to elucidate this and guide patch width selection. Four groups were selected: healthy volunteers and patients undergoing CEA with primary closure, trimmed patch (5 mm), or 8-mm patch angioplasty. Computer-generated three-dimensional models of carotid bifurcations were produced from transverse ultrasound images recorded at 1-mm intervals. Rapid prototyping generated models for flow visualization studies. Computational fluid dynamic studies were performed for each model and validated by flow visualization. Mean wall shear stress (WSS) and oscillatory shear index (OSI) maps were created for each model using pulsatile inflow at 300 mL/min. WSS of OSI >0.3 were considered pathological, predisposing to accretion of intimal hyperplasia. The resultant WSS and OSI maps were compared. The four groups comprised 8 normal carotid arteries, 6 primary closures, 6 trimmed patches, and seven 8-mm patches. Flow visualization identified flow separation and recirculation at the bifurcation increased with a patch and was related to the patch width. Computational fluid dynamic identified that primary closure had the fewest areas of low WSS or elevated OSI but did have mild common carotid artery stenoses at the proximal arteriotomy that caused turbulence. Trimmed patches had more regions of abnormal WSS and OSI at the bifurcation, but 8-mm patches had the largest areas of deleteriously low WSS and high OSI. Qualitative comparison among the four groups confirmed that incorporation of a patch increased areas of low WSS and high OSI at the bifurcation and that this was related to patch width. Closure technique after CEA influences the hemodynamic profile. Patching does not appear to generate favorable flow dynamics. However, a trimmed 5-mm patch may offer hemodynamic benefits over an 8

  16. In vitro comparison and evaluation of seven gastric closure modalities for natural orifice transluminal endoscopic surgery (NOTES)

    NARCIS (Netherlands)

    Voermans, R. P.; Worm, A. M.; van Berge Henegouwen, M. I.; Breedveld, P.; Bemelman, W. A.; Fockens, P.

    2008-01-01

    BACKGROUND AND STUDY AIMS: Secure transluminal closure is the most fundamental prerequisite for the safe introduction of natural orifice transluminal endoscopic surgery (NOTES). The aim was to compare acute strength of various gastrotomy closure techniques in an in vitro porcine stomach model by

  17. Yucca Mountain Waste Package Closure System

    Energy Technology Data Exchange (ETDEWEB)

    Herschel Smartt; Arthur Watkins; David Pace; Rodney Bitsoi; Eric Larsen; Timothy McJunkin; Charles Tolle

    2006-04-01

    The current disposal path for high-level waste is to place the material into secure waste packages that are inserted into a repository. The Idaho National Laboratory has been tasked with the development, design, and demonstration of the waste package closure system for the repository project. The closure system design includes welding three lids and a purge port cap, four methods of nondestructive examination, and evacuation and backfill of the waste package, all performed in a remote environment. A demonstration of the closure system will be performed with a full-scale waste package.

  18. Yucca Mountain Waste Package Closure System

    Energy Technology Data Exchange (ETDEWEB)

    shelton-davis; Colleen Shelton-Davis; Greg Housley

    2005-10-01

    The current disposal path for high-level waste is to place the material into secure waste packages that are inserted into a repository. The Idaho National Laboratory has been tasked with the development, design, and demonstration of the waste package closure system for the repository project. The closure system design includes welding three lids and a purge port cap, four methods of nondestructive examination, and evacuation and backfill of the waste package, all performed in a remote environment. A demonstration of the closure system will be performed with a full-scale waste package.

  19. Social and macro economic impact of closure

    International Nuclear Information System (INIS)

    Medeliene, D.

    1999-01-01

    The social consequences of closure of Ignalina NPP will largely depend on the actions the Government takes. If it puts in place the conditions which enable the International Financial Institutions to assist Lithuania, both in providing loans and grants for decommissioning and (in the case of the EU) providing Structural Adjustment Funds for the regional economic development of the Visaginas area, then solutions to the problems of closure can be found. But if the Government delays putting into place the necessary conditions, then Lithuania will be left to solve the problems of - inter alia necessary - closure of Ignalina NPP on its own. (author)

  20. Signaling pathways and cell mechanics involved in wound closure by epithelial cell sheets.

    Science.gov (United States)

    Fenteany, G; Janmey, P A; Stossel, T P

    2000-07-13

    Sheets of cells move together as a unit during wound healing and embryonic tissue movements, such as those occurring during gastrulation and neurulation. We have used epithelial wound closure as a model system for such movements and examined the mechanisms of closure and the importance of the Rho family of Ras-related small GTPases in this process. Wounds induced in Madin-Darby canine kidney (MDCK) epithelial cell monolayers close by Rac- and phosphoinositide-dependent cell crawling, with formation of lamellipodia at the wound margin, and not by contraction of a perimarginal actomyosin purse-string. Although Rho-dependent actin bundles usually form at the margin, neither Rho activity nor formation of these structures is required for wound closure to occur at a normal rate. Cdc42 activity is also not required for closure. Inhibition of Rho or Cdc42 results, however, in statistically significant decreases in the regularity of wound closure, as determined by the ratio of wound margin perimeter over the remaining denuded area at different times. The Rac-dependent force generation for closure is distributed over several rows of cells from the wound margin, as inhibition of motility in the first row of cells alone does not inhibit closure and can be compensated for by generation of motile force in cells behind the margin. Furthermore, we observed high levels of Rac-dependent actin assembly in the first few rows of cells from the wound margin. Wounds in MDCK cell sheets do not close by purse-string contraction but by a crawling behavior involving Rac, phosphoinositides and active movement of multiple rows of cells. This finding suggests a new distributed mode of signaling and movement that, nevertheless, resembles individual cell motility. Although Rho and Cdc42 activities are not required for closure, they have a role in determining the regularity of closure.

  1. A randomized clinical trial to compare three methods of orthodontic space closure.

    Science.gov (United States)

    Dixon, V; Read, M J F; O'Brien, K D; Worthington, H V; Mandall, N A

    2002-03-01

    To compare the rates of orthodontic space closure for: Active ligatures, polyurethane powerchain (Rocky Mountain Orthodontics, RMO Europe, Parc d'Innovation, Rue Geiler de Kaysersberg, 67400 Illkirch-Graffenstaden, Strasbourg, France) and nickel titanium springs. Patients entering the space closure phase of fixed orthodontic treatment attending six orthodontic providers. Twelve patients received active ligatures (48 quadrants), 10 patients received powerchain (40 quadrants) and 11 patients, nickel-titanium springs (44 quadrants). Patients were randomly allocated for treatment with active ligatures, powerchain or nickel titanium springs. Upper and lower study models were collected at the start of space closure (T(o)) and 4 months later (T(1)). We recorded whether the patient wore Class II or Class III elastics. Space present in all four quadrants was measured, by a calibrated examiner, using Vernier callipers at T(o) and T(1.) The rate of space closure, in millimetres per month (4 weeks) and a 4-monthly rate, was then calculated. Examiner reliability was assessed at least 2 weeks later. Mean rates of space closure were 0.35 mm/month for active ligatures, 0.58 mm/month for powerchain, and 0.81 mm/month for NiTi springs. No statistically significant differences were found between any methods with the exception of NiTi springs showing more rapid space closure than active ligatures (P space closure. NiTi springs gave the most rapid rate of space closure and may be considered the treatment of choice. However, powerchain provides a cheaper treatment option that is as effective. The use of inter-arch elastics does not appear to influence rate of space closure.

  2. [Abdominal wall closure in laparotomy].

    Science.gov (United States)

    Bellón-Caneiro, Juan M

    2005-03-01

    The midline laparotomy is among the most common ways of accessing the peritoneal cavity. This approach is not only used for surgery of the digestive tract but is also extensively applied in vascular, gynecology and urological surgery. When this surgical procedure is conducted in an emergency setting, and depending on the type of surgery (clean and /or contaminated), the incidence of complications may be particularly high, especially when acute dehiscence of the wall occurs (evisceration). Furthermore, the rate of herniation related to midline laparotomy is still high at approximately 16% of cases. Despite efforts to evaluate different suture techniques, suture threads (reabsorbable or non-reabsorbable) and general factors that may interfere with the repair process, the incidence of complications associated with this approach has not been reduced. After multiple studies including meta-analyses, the outcome of laparotomy closure has not essentially improved. We should therefore consider the use of new ways of closing the abdomen in selected patients that might somehow reinforce the surgical wound and notably reduce the incidence of short- and medium-term complications. One such method could perhaps be the use of a biomaterial to support and strengthen conventional sutures.

  3. Extender for securing a closure

    Science.gov (United States)

    Thomas, II, Patrick A.

    2012-10-02

    An apparatus for securing a closure such as door or a window that opens and closes by movement relative to a fixed structure such as a wall or a floor. Many embodiments provide a device for relocating a padlock from its normal location where it secures a fastener (such as a hasp) to a location for the padlock that is more accessible for locking and unlocking the padlock. Typically an extender is provided, where the extender has a hook at a first end that is disposed through the eye of the staple of the hasp, and at an opposing second end the extender has an annulus, such as a hole in the extender or a loop or ring affixed to the extender. The shackle of the padlock may be disposed through the annulus and may be disposed through the eye of a second staple to secure the door or window in a closed or open position. Some embodiments employ a rigid sheath to enclose at least a portion of the extender. Typically the rigid sheath has an open state where the hook is exposed outside the sheath and a closed state where the hook is disposed within the sheath.

  4. 2101-M pond closure plan

    International Nuclear Information System (INIS)

    1993-06-01

    This document describes activities for the closure of a surface impoundment (2101-M Pond) at the Hanford Site. The 2101-H Pond was initially constructed in 1953 to serve as a drainage collection area for the 2101-H Building. (Until the Basalt Waste Isolation Project (BWIP) Laboratory was constructed in the 2101-M Building in 1979--1981, the only source contributing discharge to the pond was condensate water from the 2101-H Building heating, ventilation, and air conditioning (HVAC) system. The drains for the BWIP Laboratory rooms were plumbed into a 4-in., cast-iron, low-pressure drain pipe that carries waste water from the HVAC system to the pond. During the active life of the BWIP Laboratory, solutions of dissolved barium in groundwater samples were discharged to the 2101-M Pond via the laboratory drains. As a result of the discharges, a Part A permit application was initially submitted to the Washington State Department of Ecology (Ecology) in August 1986 which designates the 2101-M Pond as a surface impoundment

  5. Cyanoacrylate for Intraoral Wound Closure: A Possibility?

    Directory of Open Access Journals (Sweden)

    Parimala Sagar

    2015-01-01

    Full Text Available Wound closure is a part of any surgical procedure and the objective of laceration repair or incision closure is to approximate the edges of a wound so that natural healing process may occur. Over the years new biomaterials have been discovered as an alternate to conventional suture materials. Cyanoacrylate bioadhesives are one among them. They carry the advantages of rapid application, patient comfort, resistance to infection, hemostatic properties, and no suture removal anxiety. Hence this study was undertaken to study the effect of long chain cyanoacrylate as an adhesive for intraoral wound closure and also to explore its hemostatic and antibacterial effects. Isoamyl-2-cyanoacrylate (AMCRYLATE was used as the adhesive in the study. In conclusion isoamyl cyanoacrylate can be used for intraoral wound closure, as an alternative to sutures for gluing the mucoperiosteum to bone, for example, after impaction removal, periapical surgeries, and cleft repair. Its hemostatic and antibacterial activity has to be further evaluated.

  6. Landfill closure with dredged materials - desktop analysis.

    Science.gov (United States)

    2014-08-01

    This report describes a Rutgers University project for the New Jersey Department of : Transportation (NJDOT) designed to analyze the potential for closure of New Jersey : landfills using dredge material from existing Confined Disposal Facilities (CDF...

  7. 49 CFR 195.124 - Closures.

    Science.gov (United States)

    2010-10-01

    ... comply with the ASME Boiler and Pressure Vessel Code, section VIII, Pressure Vessels, Division 1, and must have pressure and temperature ratings at least equal to those of the pipe to which the closure is...

  8. 32 CFR 989.25 - Base closure and realignment.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Base closure and realignment. 989.25 Section 989... PROTECTION ENVIRONMENTAL IMPACT ANALYSIS PROCESS (EIAP) § 989.25 Base closure and realignment. Base closure or realignment may entail special requirements for environmental analysis. The permanent base closure...

  9. Nursing home closures, changes in ownership, and competition.

    Science.gov (United States)

    Castle, Nicholas G

    2005-01-01

    This research examines the relationship of competition among nursing homes and the likelihood of their closure or change in ownership. The study uses nationally representative data from the 1992-1998 Online Survey, Certification, and Reporting system, and is supplemented with several other primary and secondary data sources. It is hypothesized that facilities located in more competitive environments will be more likely to close. Multinomial logistic regression analyses are employed to examine this hypothesis in a model containing organizational and aggregate resident characteristics, and market factors. The Herfindahl index is used as a measure of competition. The descriptive analysis shows that 621 nursing homes closed and 6,471 changed ownership from 1992 to 1998. The incidence rate of closures was .7% of facilities per year. The multivariate analysis shows that facilities located in more competitive environments were significantly more likely to close.

  10. Exceptional closure of UNIQA office at CERN

    CERN Multimedia

    HR Department

    2009-01-01

    The UNIQA office at CERN will be closed from Wednesday 18 February to Friday 20 February due to painting work. During this closure, the Headquarters of UNIQA in Geneva will remain at the disposal of the members. See details https://cern.ch/chis/UNIQA_Offices.asp The CERN office will re-open on Monday 23 February according to the normal schedule. We apologise for any inconvenience caused by this closure.

  11. Possibility of space closure without initial alignment

    OpenAIRE

    Amit Jain; Saugat Ray; Rajat Mitra; S S Chopra

    2015-01-01

    Orthodontic space closure had always remained in focus due to complex biomechanics involved in almost all the treatment modalities. Although lot of efforts have been made from time to time to control the anchorage by complex wire bending or surgical methods like temporary anchorage devices (TAD′s), but all have some added inherent disadvantage. An effort has been made to do carry out orthodontic space closure without any complex archwire bending or any surgically assisted method including TAD...

  12. Factors affecting closure of a temporary stoma.

    Science.gov (United States)

    Taylor, Claire; Varma, Sarah

    2012-01-01

    The purpose of the study was to examine time to reversal of a temporary ostomy, reasons for delayed closure, and patient satisfaction with the scheduling of their closure and related hospital care. Cross-sectional, descriptive study. The target population comprised patients who underwent creation of a temporary ostomy and reversal surgery within one National Health System Hospital Trust in the United Kingdom. The population served by this Trust are ethnically and socioeconomically diverse, predominantly living in urban areas around Greater London. Sixty-one persons who met inclusion criteria were identified. A two-step analytical process was undertaken. First, a literature review examining incidence and causes of delayed stoma closure was undertaken. Second, a postal survey of all patients who had had their stoma closed in 2009 was conducted. Respondents were allowed 2 weeks to complete and return the questionnaire. The survey instrument was developed locally and subjected to content validation using ostomy patients, surgical and nursing colleagues. It consisted of 9 questions querying time from original surgery to closure, reasons for delaying closure surgery beyond 12 weeks, and satisfaction with care. Twenty-seven patients returned their questionnaires, indicating they consented to participate; a response rate of 44%. Half of the respondents (n = 14 [52%]) underwent closure surgery within 6 months of stoma formation; the remaining 48% waited more than 6 months (median: 6.5 months, range: 1.5-26 months). Thirteen patients (48%) reported a delay in receiving their stoma closure; the main reason cited was the need for a course of adjuvant postoperative chemotherapy. Three quarters of respondents (22 [74%]) were satisfied with the overall care they received. Findings from this study suggest that stoma closure may be associated with fewest complications if performed before 12 weeks.

  13. Theater gateway closure: a strategic level barricade

    Science.gov (United States)

    logistical planners at the strategic level can anticipate or mitigate the effects of a theater gateway closure on military operations. Through two...the national elements of power was used to find the strategic level effects of the anomaly, that is an unexpected theater gateway closure. It was found...operations. A detailed analysis of the theater gateways location is critical to mitigate or anticipate the sustainment impacts on military operations

  14. Special closures for steel drum shipping containers

    International Nuclear Information System (INIS)

    Bonzon, L.L.; Otts, J.V.

    1976-01-01

    The objective of this program was to develop special lid closures for typical, steel drum, radioactive material shipping containers. Previous experience and testing had shown that the existing container was adequate to withstand the required environmental tests for certification, but that the lid and closure were just marginally effective. Specifically, the lid closure failed to consistently maintain a tight seal between the container and the lid after drop tests, thus causing the package contents to be vulnerable in the subsequent fire test. Recognizing the deficiency, the United States Energy Research and Development Administration requested the development of new closure(s) which would: (1) be as strong and resistant to a drop as the bottom of the container; (2) have minimal economic impact on the overall container cost; (3) maximize the use of existing container designs; (4) consider crush loads; and (5) result in less dependence on personnel and loading procedures. Several techniques were evaluated and found to be more effective than the standard closure mechanism. Of these, three new closure techniques were designed, fabricated, and proven to be structurally adequate to provide containment when a 454-kg drum was drop tested from 9.14-m onto an unyielding surface. The three designs were: (1) a 152-mm long lid extension or skirt welded to the standard drum lid, (2) a separate inner lid, with 152-mm long skirt and (3) C-clamps used at the container-lid interface. Based upon structural integrity, economic impact, and minimal design change, the lid extension is the recommended special closure

  15. The determinants of care home closure.

    Science.gov (United States)

    Allan, Stephen; Forder, Julien

    2015-03-01

    This study investigates the causes of full closure of care homes in the English care home/nursing home market. We develop theoretical arguments about two causes for closure that are triggered by errors or external shocks: poor economic sustainability and regulatory action. Homes aiming to operate with lower quality in the market are argued for a number of reasons to be more susceptible to errors/shocks in setting quality, especially negative errors, leading to an empirical hypothesis that observed quality should negatively affect closure chance. In addition, given quality, homes facing relatively high levels of local competition should also have an increased chance of closure. We use a panel of care homes from 2008 and 2010 to examine factors affecting their closure status in subsequent years. We allow for the potential endogeneity of home quality and use multiple imputation to replace missing data. Results suggest that homes with comparatively higher quality and/or lower levels of competition have less chance of closure than other homes. We discuss that the results provide some support for the policy of regulators providing quality information to potential purchasers in the market. © 2015 The Authors. Health Economics published by John Wiley & Sons Ltd.

  16. Real closures of models of weak arithmetic

    Czech Academy of Sciences Publication Activity Database

    Jeřábek, Emil; Kolodziejczyk, L. A.

    2013-01-01

    Roč. 52, 1-2 (2013), s. 143-157 ISSN 0933-5846 R&D Projects: GA AV ČR IAA100190902; GA MŠk(CZ) 1M0545 Institutional support: RVO:67985840 Keywords : bounded arithmetic * real-closed field * recursive saturation Subject RIV: BA - General Mathematics http://link.springer.com/article/10.1007%2Fs00153-012-0311-x

  17. Effect of gender and Frankfort mandibular plane angle on orthodontic space closure: a randomized controlled trial.

    Science.gov (United States)

    Ireland, A J; Songra, G; Clover, M; Atack, N E; Sherriff, M; Sandy, J R

    2016-05-01

    To determine the effect of gender and Frankfort mandibular plane angle (FMPA) on extraction space closure. A single district general hospital. The sample population were 11- to 18-year-olds undergoing upper and lower fixed appliance therapy following the loss of a premolar in each quadrant. A total of 100 patients undergoing upper and lower fixed appliance therapy following the loss of four premolars were randomized with stratification on two age ranges (11-14 years and 15-18 years) and three FMPAs (high, medium and low). Allocation was to one of three treatment groups: conventional, active or passive self-ligating brackets, with an allocation ratio of 1:2:2. All subjects were treated using the same archwire sequence and space closing mechanics. Space closure was measured on models taken every 12 weeks throughout treatment. All measurements were taken by one operator, blinded to bracket type. A total of 98 patients were followed to completion. Data were analysed using linear mixed models and demonstrated no statistically significant difference between bracket types with respect to space closure. Therefore, the data were pooled to determine the effect of gender and FMPA on space closure. At all stages of space closure, there was a significant effect of gender (results are presented as effect size, lower and upper 95% confidence intervals and probability), that is passive [1.064, 0.521, 1.607, 0.001], active [0.825, 0.312, 1.339, 0.002] and total space closure [1.029, 0.527, 1.531, 0.001]. There was no statistically significant effect of FMPA on space closure. Space closure during fixed appliance therapy is affected by gender but is unaffected by FMPA. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  18. A comparison between mass closure and layered closure of midline abdominal incisions

    Directory of Open Access Journals (Sweden)

    Gurjit Singh

    2012-01-01

    Full Text Available Background: Traditionally, a laparotomy wound is closed in layers co-opting the various layers anatomically. A new method of closure, namely single layer closure technique (mass closure technique has come into vogue. Aims: This study aims to evaluate the benefits or otherwise between single layer closure and layered closure after comparing it with studies available in literature. Settings and Design: This study was performed in a teaching institute in patients undergoing laparotomy, either planned or emergency. Materials and Methods: A total of 80 cases were selected at random and the study was carried out over a period of 2 years. The cases were equally divided into two groups of 40. In both groups, vertical midline incision was used. In the first group, abdomen was closed using the single layer closure technique. Continuous suturing with burial of the knots was done in 20 patients and interrupted mass closure was done in another 20 patients. In the other group, the abdomen was closed in layers. The patients were followed up for minimum 6 months. Patients who did not turn up for follow up were asked to notify the development of any wound complication through postal correspondence. Results: The time required for closure was considerably less when continuous suture technique was used. One patient in the mass closure group and four in the layered group developed post-operative wound infections. One patient in the layered closure group developed a stitch sinus. There were two cases of burst abdomen with the layered closure technique. Two patients in the layered closure group developed incisional hernias 6 months post-operatively. Conclusions: Single layer closure technique offers certain definite advantage over the layered closure technique with respect to the time required for closure of the incision, incidence of wound dehiscence and the incidence of incisional hernia. However, the true incidence of wound dehiscence (burst abdomen and incisional

  19. Accelerating cleanup: Paths to closure

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-06-01

    This report describes the status of Environmental Management`s (EM`s) cleanup program and a direction forward to complete achievement of the 2006 vision. Achieving the 2006 vision results in significant benefits related to accomplishing EM program objectives. As DOE sites accelerate cleanup activities, risks to public health, the environment, and worker safety and health are all reduced. Finding more efficient ways to conduct work can result in making compliance with applicable environmental requirements easier to achieve. Finally, as cleanup activities at sites are completed, the EM program can focus attention and resources on the small number of sites with more complex cleanup challenges. Chapter 1 describes the process by which this report has been developed and what it hopes to accomplish, its relationship to the EM decision-making process, and a general background of the EM mission and program. Chapter 2 describes how the site-by-site projections were constructed, and summarizes, for each of DOE`s 11 Operations/Field Offices, the projected costs and schedules for completing the cleanup mission. Chapter 3 presents summaries of the detailed cleanup projections from three of the 11 Operations/Field Offices: Rocky Flats (Colorado), Richland (Washington), and Savannah River (South Carolina). The remaining eight Operations/Field Office summaries are in Appendix E. Chapter 4 reviews the cost drivers, budgetary constraints, and performance enhancements underlying the detailed analysis of the 353 projects that comprise EM`s accelerated cleanup and closure effort. Chapter 5 describes a management system to support the EM program. Chapter 6 provides responses to the general comments received on the February draft of this document.

  20. Accelerating cleanup: Paths to closure

    International Nuclear Information System (INIS)

    1998-06-01

    This report describes the status of Environmental Management's (EM's) cleanup program and a direction forward to complete achievement of the 2006 vision. Achieving the 2006 vision results in significant benefits related to accomplishing EM program objectives. As DOE sites accelerate cleanup activities, risks to public health, the environment, and worker safety and health are all reduced. Finding more efficient ways to conduct work can result in making compliance with applicable environmental requirements easier to achieve. Finally, as cleanup activities at sites are completed, the EM program can focus attention and resources on the small number of sites with more complex cleanup challenges. Chapter 1 describes the process by which this report has been developed and what it hopes to accomplish, its relationship to the EM decision-making process, and a general background of the EM mission and program. Chapter 2 describes how the site-by-site projections were constructed, and summarizes, for each of DOE's 11 Operations/Field Offices, the projected costs and schedules for completing the cleanup mission. Chapter 3 presents summaries of the detailed cleanup projections from three of the 11 Operations/Field Offices: Rocky Flats (Colorado), Richland (Washington), and Savannah River (South Carolina). The remaining eight Operations/Field Office summaries are in Appendix E. Chapter 4 reviews the cost drivers, budgetary constraints, and performance enhancements underlying the detailed analysis of the 353 projects that comprise EM's accelerated cleanup and closure effort. Chapter 5 describes a management system to support the EM program. Chapter 6 provides responses to the general comments received on the February draft of this document

  1. Endoscopic closure of duodenal perforations by using an over-the-scope clip: a randomized, controlled porcine study.

    Science.gov (United States)

    von Renteln, Daniel; Rudolph, Hans-Ulrich; Schmidt, Arthur; Vassiliou, Melina C; Caca, Karel

    2010-01-01

    Duodenal perforations during diagnostic upper endoscopy are rare; however, when therapeutic techniques are performed, the reported incidence is as great as 2.8%. Surgical repair is usually mandated, but it is associated with significant morbidity and mortality. To compare closure of duodenal perforations by using an over-the-scope clip (OTSC) with a surgical closure. Randomized, controlled animal study. Animal facility laboratory. Domestic pigs (24 females). Large (10-mm) duodenal perforations were created by using an endoscopic needle-knife. The animals were randomly assigned to either open surgical repair (n=12) or endoscopic closure by using the OTSC system (n=12). Pressurized leak tests were performed during necropsy. One major bleed occurred because of a liver injury during creation of the duodenotomy. Mean time for endoscopic closure was 5 minutes (range, 3-8 min; SD +/- 2). No complications occurred during any of the closure procedures. At necropsy, all OTSC and surgical closures demonstrated complete sealing of duodenotomy sites. Pressurized leak tests demonstrated a mean burst pressure of 166 mm Hg (range, 80-260; SD +/- 65) for OTSC closures and 143 mm Hg (range, 30-300, SD +/- 83) for surgical sutures. Ex vivo intact duodenal specimens exhibited a mean burst pressure of 247 mm Hg (range, 200-300; SD +/- 35), which was significantly higher compared with in vivo OTSC and surgical closures (P < .01). There were no significant differences between burst pressures of OTSC and surgical closures (P = .461). Nonsurvival setting. Endoscopic closure of duodenal perforations by using the OTSC system is comparable with surgical closure in a nonsurvival porcine model. This technique is easy to perform and seems suitable for repairing duodenal perforations. 2010 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.

  2. Predicting Financial Distress and Closure in Rural Hospitals.

    Science.gov (United States)

    Holmes, George M; Kaufman, Brystana G; Pink, George H

    2017-06-01

    Annual rates of rural hospital closure have been increasing since 2010, and hospitals that close have poor financial performance relative to those that remain open. This study develops and validates a latent index of financial distress to forecast the probability of financial distress and closure within 2 years for rural hospitals. Hospital and community characteristics are used to predict the risk of financial distress 2 years in the future. Financial and community data were drawn for 2,466 rural hospitals from 2000 through 2013. We tested and validated a model predicting a latent index of financial distress (FDI), measured by unprofitability, equity decline, insolvency, and closure. Using the predicted FDI score, hospitals are assigned to high, medium-high, medium-low, and low risk of financial distress for use by practitioners. The FDI forecasts 8.01% of rural hospitals to be at high risk of financial distress in 2015, 16.3% as mid-high, 46.8% as mid-low, and 28.9% as low risk. The rate of closure for hospitals in the high-risk category is 4 times the rate in the mid-high category and 28 times that in the mid-low category. The ability of the FDI to discriminate hospitals experiencing financial distress is supported by a c-statistic of .74 in a validation sample. This methodology offers improved specificity and predictive power relative to existing measures of financial distress applied to rural hospitals. This risk assessment tool may inform programs at the federal, state, and local levels that provide funding or support to rural hospitals. © 2016 National Rural Health Association.

  3. Post-operative analgesic requirement in non-closure and closure of peritoneum during open appendectomy

    International Nuclear Information System (INIS)

    Khan, A.W.; Maqsood, R.; Saleem, M.M.

    2017-01-01

    To compare the mean post-operative analgesic requirement in non-closure and closure of peritoneum during open appendectomy. Study Design: Randomized controlled trial. Place and Duration of Study: Department of General Surgery Combined Military Hospital Quetta, from 1st August 2014 to 30th April 2015. Material and Methods: A total of 60 patients were included in this study and were divided into two groups of 30 each. Patients in group A underwent open appendectomy with closure of peritoneum while patients in group B had non-closure of peritoneum during the same procedure. Post-operatively, pain severity was assessed on visual analogue scale (VAS) numeric pain distress scale. On presence of VAS numeric pain distress scale between 5 to 7, intramuscular (IM) diclofenac sodium was given and on score >7, intravascular (IV) tramadol was given. The final outcome was measured at day 0 and day 1. Results: Pain score and analgesic requirements were significantly less in non-closure group than closure group on day 0 and day 1, showing statistically significant difference between the two groups. Conclusion: Mean post-operative analgesic requirement is significantly less in non-closure group as compared to closure group during open appendectomy. (author)

  4. Natural orifice transluminal endoscopic surgery gastrotomy closure with an over-the-endoscope clip: a randomized, controlled porcine study (with videos).

    Science.gov (United States)

    von Renteln, Daniel; Schmidt, Arthur; Vassiliou, Melina C; Gieselmann, Maria; Caca, Karel

    2009-10-01

    surgical closure in a nonsurvival porcine model. This technique is easy to perform and is suitable for NOTES gastrotomy closure.

  5. Endoscopic full-thickness resection and defect closure in the colon.

    Science.gov (United States)

    von Renteln, Daniel; Schmidt, Arthur; Vassiliou, Melina C; Rudolph, Hans-Ulrich; Caca, Karel

    2010-06-01

    Endoscopic full-thickness resection (eFTR) is a minimally invasive method for en bloc resection of GI lesions. The aim of this pilot study was to evaluate the feasibility of a grasp-and-snare technique for eFTR combined with an over-the-scope clip (OTSC) for defect closure. Nonsurvival animal study. Animal laboratory. Fourteen female domestic pigs. The eFTR was performed in porcine colons using a novel tissue anchor in combination with a standard monofilament snare and 14 mm OTSC. In the first group (n = 20), closure of the colonic defects with OTSC was attempted after the resection. In the second group (n = 8), an endoloop was used to secure the resection base before eFTR was performed. In the first group (n = 20), eFTR specimens ranged from 2.4 to 5.5 cm in diameter. Successful closure was achieved in 9 out of 20 cases. Mean burst pressure for OTSC closure was 29.2 mm Hg (range, 2-90; SD, 29.92). Injury to adjacent organs occurred in 3 cases. Lumen obstruction due to the OTSC closure occurred in 3 cases. In the second group (n = 8), the diameter of specimens ranged from 1.2 to 2.2 cm. Complete closure was achieved in all cases, with a mean burst pressure of 76.6 mm Hg (range, 35-120; SD, 31). Lumen obstruction due to the endoloop closure occurred in one case. No other complications or injuries were observed in the second group. Nonsurvival setting. Colonic eFTR using the grasp-and-snare technique is feasible in an animal model. Ligation of the resection base with an endoloop before eFTR seems to reduce complication rates and improve closure success and leak test results despite yielding smaller specimens. Copyright 2010 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.

  6. FGFR3 promotes synchondrosis closure and fusion of ossification centers through the MAPK pathway

    Science.gov (United States)

    Matsushita, Takehiko; Wilcox, William R.; Chan, Yuk Yu; Kawanami, Aya; Bükülmez, Hülya; Balmes, Gener; Krejci, Pavel; Mekikian, Pertchoui B.; Otani, Kazuyuki; Yamaura, Isakichi; Warman, Matthew L.; Givol, David; Murakami, Shunichi

    2009-01-01

    Activating mutations in FGFR3 cause achondroplasia and thanatophoric dysplasia, the most common human skeletal dysplasias. In these disorders, spinal canal and foramen magnum stenosis can cause serious neurologic complications. Here, we provide evidence that FGFR3 and MAPK signaling in chondrocytes promote synchondrosis closure and fusion of ossification centers. We observed premature synchondrosis closure in the spine and cranial base in human cases of homozygous achondroplasia and thanatophoric dysplasia as well as in mouse models of achondroplasia. In both species, premature synchondrosis closure was associated with increased bone formation. Chondrocyte-specific activation of Fgfr3 in mice induced premature synchondrosis closure and enhanced osteoblast differentiation around synchondroses. FGF signaling in chondrocytes increases Bmp ligand mRNA expression and decreases Bmp antagonist mRNA expression in a MAPK-dependent manner, suggesting a role for Bmp signaling in the increased bone formation. The enhanced bone formation would accelerate the fusion of ossification centers and limit the endochondral bone growth. Spinal canal and foramen magnum stenosis in heterozygous achondroplasia patients, therefore, may occur through premature synchondrosis closure. If this is the case, then any growth-promoting treatment for these complications of achondroplasia must precede the timing of the synchondrosis closure. PMID:18923003

  7. Material balance and diet in bioregenerative life support systems: Connection with coefficient of closure

    Science.gov (United States)

    Manukovsky, N. S.; Kovalev, V. S.; Somova, L. A.; Gurevich, Yu. L.; Sadovsky, M. G.

    Bioregenerative life support systems (BLSS) with different coefficients of closure are considered. The 66.2% coefficient of closure achieved in "BIOS-3" facility experiments has been taken as a base value. The increase in coefficient of closure up to 72.6-93.0% is planned due to use of soil-like substrate (SLS) and concentrating of urine. Food values were estimated both in a base variant ("BIOS-3"), and with increases in the coefficient of closure. It is shown that food requirements will be more fully satisfied by internal crop production with an increase in the coefficient of closure of the BLSS. Changes of massflow rates on an 'input-output' and inside BLSS are considered. Equations of synthesis and degradation of organic substances in BLSS were examined using a stoichiometric model. The paper shows that at incomplete closure of BLSS containing SLS there is a problem of nitrogen balancing. To compensate for the removal of nitrogen from the system in urine and feces, it is necessary to introduce food and a nitrogen-containing additive.

  8. Radiographic prognostic factors determining spontaneous space closure after loss of the permanent first molar.

    Science.gov (United States)

    Patel, Sameer; Ashley, Paul; Noar, Joseph

    2017-04-01

    Permanent first molars (PFM) with a poor prognosis are routinely extracted in children throughout the United Kingdom. National guidelines suggest that to achieve spontaneous closure for the mandibular arch, the PFM should be extracted at 8 to 10 years of age, during bifurcation formation of the second molar. The literature is of limited quality and has suggested alternative variables that may be associated with successful space closure. Our aim was to investigate the radiographic prognostic factors associated with space closure after extraction of PFM. Two objectives of the research are reported in this article: to determine factors that might predict space closure of the second molar after extraction of the PFM, and to develop a tool kit to aid clinical decision making. We assessed 148 maxillary and 153 mandibular PFM extracted from 81 participants retrospectively. Dental age, second molar developmental stage, second premolar and second molar angulations, and presence or absence of the third molar were assessed on the preextraction orthopantomograms. Outcome was assessed via visual examination, study models, or radiographs. Closure occurred in 89.9% of the maxillary and 49.0% of the mandibular quadrants. Dental age was statistically, but not clinically, significant in the maxillary arch (P space closure. The developed tool kit requires further validity testing. Copyright © 2016 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

  9. The computation of turbulent recirculating flow using curvilinear finite differences. Application of the k - epsilon model to the flow in dredged trenches

    International Nuclear Information System (INIS)

    Alfrink, B.J.

    1981-08-01

    The report treats the computation of turbulent recirculating flow in dredged trenches. The mathematical model consists of the full two-dimensional unsteady Reynolds equations, formulated in primitive variables. Turbulence closure is obtained by means of a two-equation (k - epsilon) model. The numerical technique is based on the use of curvilinear finite differences in space and of fractional steps in time. A procedure is proposed to apply the model for varying roughness circumstances. The value of the Von Karman constant can be determined from geometric information. Afterwards, only the c 1 -constant is adapted by means of a degenerated epsilon-equation. The report describes an extensive sensitivity study for the inlet conditions and the empirical constants. Ultimately, the results of the mathematical model are very satisfactory. Compared with laboratory experiments, the recirculation length is only underpredicted with 10%

  10. Baseline factors affecting closure of venous leg ulcers.

    Science.gov (United States)

    Marston, William A; Ennis, William J; Lantis, John C; Kirsner, Robert S; Galiano, Robert D; Vanscheidt, Wolfgang; Eming, Sabine A; Malka, Marcin; Cargill, D Innes; Dickerson, Jaime E; Slade, Herbert B

    2017-11-01

    The objective of this study was to characterize factors associated with closure of venous leg ulcers (VLUs) in a pooled analysis of subjects from three randomized clinical trials. Closure of VLUs after treatment with HP802-247, an allogeneic living cell therapy consisting of growth-arrested human keratinocytes and fibroblasts, vs standard therapy with compression bandaging was evaluated in three phase 3 clinical trials of similar design. Two trials enrolled subjects with VLUs ranging from 2 cm 2 to 12 cm 2 in area with 12-week treatment periods; the third trial enrolled subjects with VLUs between >12 cm 2 and ≤36 cm 2 with a 16-week treatment period. The first trial went to completion but failed to demonstrate a benefit to therapy with HP802-247 compared with placebo, and because of this, the remaining trials were terminated before completion. On the basis of no differences in outcomes between groups, subjects from both HP802-247 and control groups were pooled across all three studies. Cox proportional hazards regression analysis was employed to evaluate factors associated with VLU closure. This analysis included data from 716 subjects with VLU. Factors evaluated for association with healing included age, gender, race, diabetes, glycated hemoglobin level, body mass index, treatment (HP802-247 vs compression alone), and ulcer characteristics including location and area and duration at baseline. In an initial model including all of these putative factors, the following were significant at the P < .10 level: diagnosis of diabetes mellitus, gender, wound location (ankle or leg), baseline wound area, and wound duration at baseline. In a final model including only these factors, all but diabetes mellitus were significant at the P < .05 level. Effect sizes were as follows (hazard ratio [95% confidence interval]): female gender (1.384 [1.134-1.690]), wound location on the leg (1.490 [1.187-1.871]), smaller wound area at baseline (0.907 [0.887-0.927]), and shorter

  11. Closure of shallow underground injection wells

    International Nuclear Information System (INIS)

    Veil, J.A.; Grunewald, B.

    1993-01-01

    Shallow injection wells have long been used for disposing liquid wastes. Some of these wells have received hazardous or radioactive wastes. According to US Environmental Protection Agency (EPA) regulations, Class IV wells are those injection wells through which hazardous or radioactive wastes are injected into or above an underground source of drinking water (USDW). These wells must be closed. Generally Class V wells are injection wells through which fluids that do not contain hazardous or radioactive wastes are injected into or above a USDW. Class V wells that are responsible for violations of drinking water regulations or that pose a threat to human health must also be closed. Although EPA regulations require closure of certain types of shallow injection wells, they do not provide specific details on the closure process. This paper describes the regulatory background, DOE requirements, and the steps in a shallow injection well closure process: Identification of wells needing closure; monitoring and disposal of accumulated substances; filling and sealing of wells; and remediation. In addition, the paper describes a major national EPA shallow injection well enforcement initiative, including closure plan guidance for wells used to dispose of wastes from service station operations

  12. Stomal Closure: Strategies to Prevent Incisional Hernia

    Directory of Open Access Journals (Sweden)

    Rhiannon L. Harries

    2018-04-01

    Full Text Available Incisional hernias following ostomy reversal occur frequently. Incisional hernias at the site of a previous stoma closure can cause significant morbidity, impaired quality of life, lead to life-threatening hernia incarceration or strangulation and result in a significant financial burden on health care systems Despite this, the evidence base on the subject is limited. Many recognised risk factors for the development of incisional hernia following ostomy reversal are related to patient factors such as age, malignancy, diabetes, COPD, hypertension and obesity, and are not easily correctable. There is a limited amount of evidence to suggest that prophylactic mesh reinforcement may be of benefit to reduce the post stoma closure incisional hernia rate but a further large scale randomised controlled trial is due to report in the near future. There appears to be weak evidence to suggest that surgeons should favour circular, or “purse-string” closure of the skin following stoma closure in order to reduce the risk of SSI, which in turn may reduce incisional hernia formation. There remains the need for further evidence in relation to suture technique, skin closure techniques, mechanical bowel preparation and oral antibiotic prescription focusing on incisional hernia development as an outcome measure. Within this review, we discuss in detail the evidence base for the risk factors for the development of, and the strategies to prevent ostomy reversal site incisional hernias.

  13. Stomal Closure: Strategies to Prevent Incisional Hernia

    Science.gov (United States)

    Harries, Rhiannon L.; Torkington, Jared

    2018-01-01

    Incisional hernias following ostomy reversal occur frequently. Incisional hernias at the site of a previous stoma closure can cause significant morbidity, impaired quality of life, lead to life-threatening hernia incarceration or strangulation and result in a significant financial burden on health care systems Despite this, the evidence base on the subject is limited. Many recognised risk factors for the development of incisional hernia following ostomy reversal are related to patient factors such as age, malignancy, diabetes, COPD, hypertension and obesity, and are not easily correctable. There is a limited amount of evidence to suggest that prophylactic mesh reinforcement may be of benefit to reduce the post stoma closure incisional hernia rate but a further large scale randomised controlled trial is due to report in the near future. There appears to be weak evidence to suggest that surgeons should favour circular, or “purse-string” closure of the skin following stoma closure in order to reduce the risk of SSI, which in turn may reduce incisional hernia formation. There remains the need for further evidence in relation to suture technique, skin closure techniques, mechanical bowel preparation and oral antibiotic prescription focusing on incisional hernia development as an outcome measure. Within this review, we discuss in detail the evidence base for the risk factors for the development of, and the strategies to prevent ostomy reversal site incisional hernias. PMID:29670882

  14. Strategic Planning for Hot Cell Closure

    International Nuclear Information System (INIS)

    LANGSTAFF, D.C.

    2001-01-01

    The United States Department of Energy (DOE) and its contractor were remediating a large hot cell complex to mitigate the radiological hazard. A Resource Conservation and Recovery Act (RCRA) closure unit was determined to be located within the complex. The regulator established a challenge to develop an acceptable closure plan on a short schedule (four months). The scope of the plan was to remove all excess equipment and mixed waste from the closure unit, establish the requirements of the legally binding Closure Plan and develop an acceptable schedule. The complex has several highly radioactive tanks, tank vaults, piping, and large hot cells containing complex chemical processing equipment. Driven by a strong need to develop an effective strategy to meet cleanup commitments, three principles were followed to develop an acceptable plan: (1) Use a team approach, (2) Establish a buffer zone to support closure, and (3) Use good practice when planning the work sequence. The team was composed of DOE, contractor, and Washington State Department of Ecology (Regulator) staff. The team approach utilized member expertise and fostered member involvement and communication. The buffer zone established an area between the unregulated parts of the building and the areas that were allegedly not in compliance with environmental standards. Introduction of the buffer zone provided simplicity, clarity, and flexibility into the process. Using good practice means using the DOE Integrated Safety Management Core Functions for planning and implementing work safely. Paying adequate attention to detail when the situation required contributed to the process credibility and a successful plan

  15. Hanford Patrol Academy demolition sites closure plan

    Energy Technology Data Exchange (ETDEWEB)

    1993-09-30

    The Hanford Site is owned by the U.S. Government and operated by the U.S. Department of Energy, Richland Operations Office. Westinghouse Hanford Company is a major contractor to the U.S. Department of Energy, Richland Operations Office and serves as co-operator of the Hanford Patrol Academy Demolition Sites, the unit addressed in this paper. This document consists of a Hanford Facility Dangerous Waste Part A Permit Application, Form 3 (Revision 4), and a closure plan for the site. An explanation of the Part A Form 3 submitted with this closure plan is provided at the beginning of the Part A section. This Hanford Patrol Academy Demolition Sites Closure Plan submittal contains information current as of December 15, 1994.

  16. Mine closures yield fields of green

    International Nuclear Information System (INIS)

    Jones, S.

    1993-01-01

    The cleanup and reclamation of North America's defunct mines or those set for closure will be extremely costly, estimated to be over one trillion dollars within the next ten to twenty years. In Canada, mines are controlled by the provinces and British Columbia began reclamation of major coal mines and hard rock metal mines in 1969. Other provinces have followed suit and in 1991, Ontario ruled that new and existing mines and advanced exploration projects must be designed for closuer. Many US states are enacting similar laws and the EPA plans to require mines to submit closure plans with their permit applications. Cleanup includes the sale of usable equipment, salvage of the rest, dismantling buildings, treatment and disposal of process chemicals, hazardous materials and tainted soils as well as recontouring and revegetation of the sites. Currently, at Elliot Lake in Canada, three of Canada's largest underground uranium mines are undergoing the process of closure

  17. Biological constraints do not entail cognitive closure.

    Science.gov (United States)

    Vlerick, Michael

    2014-12-01

    From the premise that our biology imposes cognitive constraints on our epistemic activities, a series of prominent authors--most notably Fodor, Chomsky and McGinn--have argued that we are cognitively closed to certain aspects and properties of the world. Cognitive constraints, they argue, entail cognitive closure. I argue that this is not the case. More precisely, I detect two unwarranted conflations at the core of arguments deriving closure from constraints. The first is a conflation of what I will refer to as 'representation' and 'object of representation'. The second confuses the cognitive scope of the assisted mind for that of the unassisted mind. Cognitive closure, I conclude, cannot be established from pointing out the (uncontroversial) existence of cognitive constraints. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Long-term outcomes after acute primary angle closure of Caucasian chronic angle closure glaucoma patients.

    Science.gov (United States)

    Fea, Antonio Maria; Dallorto, Laura; Lavia, Carlo; Pignata, Giulia; Rolle, Teresa; Aung, Tin

    2017-07-19

    There is a lack of information about long-term results of chronic angle closure glaucoma following an acute primary angle closure attack in Caucasian patients. The aim of the study was to report morphological and functional long-term data of chronic angle closure eyes following a monolateral primary angle closure attack and to provide a comparison with their fellow eyes. Observational retrospective case series. Fifty-seven consecutive patients (114 eyes) underwent long-term follow-up analysis. Patients underwent ophthalmic assessment more than 5 years since the angle closure attack. Intraocular pressure, best-corrected visual acuity, angle assessment, vertical C/D ratio and standard automated perimetry were the main outcome measures. Comparisons were made between angle closure attack eyes and fellow eyes and between phakic and pseudophakic eyes. Mean follow-up time was 5.86 ± 1.19 years. A significant greater damage in the angle closure eyes compared with fellow eyes in both structural (mean C/D 0.61 ± 0.16; P APAC attack to prevent potential glaucoma damage in both APAC and fellow eye. © 2017 The Authors Clinical & Experimental Ophthalmology published by John Wiley & Sons Australia, Ltd on behalf of Royal Australian and New Zealand College of Ophthalmologists.

  19. Reactor vessel closure head replacements in 1997

    International Nuclear Information System (INIS)

    Anon.

    1997-01-01

    The Framatome-Jeumont Industrie consortium have completed in 1997 28 reactor vessel (RV) closure head replacements, including five on 1300 MWe class PWR units. Framatome manages the operations and handles removal and reinstallation of equipment (not including the control rod drive mechanisms (CRDM)) and the requalification tests, while JI, which manufactures the CRDMs, is involved in the CRDM cutting, re-machining and welding operations, using tools of original design, in order to optimize the RV closure head operation in terms of costs, schedule and dosage

  20. Straight line closure of congenital macrostomia

    Directory of Open Access Journals (Sweden)

    Schwarz Richard

    2004-01-01

    Full Text Available The results of patients operated on by Nepal Cleft Lip and Palate Association (NECLAPA surgeons for congenital macrostomia were prospectively studied between January 2000 and December 2002. There were four males and three females with a median age of 10 years. Three had an associated branchial arch syndrome. In all patients an overlapping repair of orbicularis oris was done. Six patients had a straight line closure with excellent cosmetic results and one a Z-plasty with a more obvious scar. All had a normal appearing commissure. Overlapping orbicularis repair with straight line skin closure for this rare congenital anomaly is recommended.

  1. Environmental considerations in mine closure planning

    International Nuclear Information System (INIS)

    Ricks, G.

    1997-01-01

    Mine closure planning considers the best ways to plan and manage the environmental changes and socio-economic effects associated with the closing of mines. While the criteria for judging successful closures may vary, it is particularly important for physical, chemical and biological stability to be achieved and for final land use to be appropriate. Trust funds are increasingly favoured as a practical means of fulfilling the requirement for a financial surety and of ensuring that financial provision is available at the end of the mine's life. (author)

  2. Possibility of space closure without initial alignment

    Directory of Open Access Journals (Sweden)

    Amit Jain

    2015-01-01

    Full Text Available Orthodontic space closure had always remained in focus due to complex biomechanics involved in almost all the treatment modalities. Although lot of efforts have been made from time to time to control the anchorage by complex wire bending or surgical methods like temporary anchorage devices (TAD′s, but all have some added inherent disadvantage. An effort has been made to do carry out orthodontic space closure without any complex archwire bending or any surgically assisted method including TAD′s.

  3. Laser peripheral iridoplasty for angle-closure.

    Science.gov (United States)

    Ng, Wai Siene; Ang, Ghee Soon; Azuara-Blanco, Augusto

    2012-02-15

    Angle-closure glaucoma is a leading cause of irreversible blindness in the world. Treatment is aimed at opening the anterior chamber angle and lowering the IOP with medical and/or surgical treatment (e.g. trabeculectomy, lens extraction). Laser iridotomy works by eliminating pupillary block and widens the anterior chamber angle in the majority of patients. When laser iridotomy fails to open the anterior chamber angle, laser iridoplasty may be recommended as one of the options in current standard treatment for angle-closure. Laser peripheral iridoplasty works by shrinking and pulling the peripheral iris tissue away from the trabecular meshwork. Laser peripheral iridoplasty can be used for crisis of acute angle-closure and also in non-acute situations.   To assess the effectiveness of laser peripheral iridoplasty in the treatment of narrow angles (i.e. primary angle-closure suspect), primary angle-closure (PAC) or primary angle-closure glaucoma (PACG) in non-acute situations when compared with any other intervention. In this review, angle-closure will refer to patients with narrow angles (PACs), PAC and PACG. We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2011, Issue 12), MEDLINE (January 1950 to January 2012), EMBASE (January 1980 to January 2012), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to January 2012), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). There were no date or language restrictions in the electronic searches for trials. The electronic databases were last searched on 5 January 2012. We included only randomised controlled trials (RCTs) in this review. Patients with narrow angles, PAC or PACG were eligible. We excluded studies that included only patients with acute presentations

  4. Closure properties of Watson-Crick grammars

    Science.gov (United States)

    Zulkufli, Nurul Liyana binti Mohamad; Turaev, Sherzod; Tamrin, Mohd Izzuddin Mohd; Azeddine, Messikh

    2015-12-01

    In this paper, we define Watson-Crick context-free grammars, as an extension of Watson-Crick regular grammars and Watson-Crick linear grammars with context-free grammar rules. We show the relation of Watson-Crick (regular and linear) grammars to the sticker systems, and study some of the important closure properties of the Watson-Crick grammars. We establish that the Watson-Crick regular grammars are closed under almost all of the main closure operations, while the differences between other Watson-Crick grammars with their corresponding Chomsky grammars depend on the computational power of the Watson-Crick grammars which still need to be studied.

  5. Alterations of papilla dimensions after orthodontic closure of the maxillary midline diastema: a retrospective longitudinal study.

    Science.gov (United States)

    Jeong, Jin-Seok; Lee, Seung-Youp; Chang, Moontaek

    2016-06-01

    The aim of this study was to evaluate alterations of papilla dimensions after orthodontic closure of the diastema between maxillary central incisors. Sixty patients who had a visible diastema between maxillary central incisors that had been closed by orthodontic approximation were selected for this study. Various papilla dimensions were assessed on clinical photographs and study models before the orthodontic treatment and at the follow-up examination after closure of the diastema. Influences of the variables assessed before orthodontic treatment on the alterations of papilla height (PH) and papilla base thickness (PBT) were evaluated by univariate regression analysis. To analyze potential influences of the 3-dimensional papilla dimensions before orthodontic treatment on the alterations of PH and PBT, a multiple regression model was formulated including the 3-dimensional papilla dimensions as predictor variables. On average, PH decreased by 0.80 mm and PBT increased after orthodontic closure of the diastema (Porthodontic treatment influenced the alteration of PH. With respect to the alteration of PBT, the diastema width (P=0.045) and PBT (P=0.000) were found to be influential factors. PBT before the orthodontic treatment significantly influenced the alteration of PBT in the multiple regression model. PH decreased but PBT increased after orthodontic closure of the diastema. The papilla dimensions before orthodontic treatment influenced the alterations of PH and PBT after closure of the diastema. The PBT increased more when the diastema width before the orthodontic treatment was larger.

  6. Profile of angle closure in a tertiary care center in north India

    Directory of Open Access Journals (Sweden)

    Ichhpujani Parul

    2010-01-01

    Full Text Available Purpose: To study the demographic and clinical profile of the types of primary angle closure patients presenting at a tertiary care center in North India. Materials and Methods: Clinic records of patients diagnosed as primary angle closure were reviewed. International Society of Geographical and Epidemiological Ophthalmology (ISGEO classification scheme was used to categorize patients. Demographic and clinical data including prior management was collected and analyzed. Main Outcome measures were age, sex, symptomatology, best corrected visual acuity (BCVA, intraocular pressure (IOP, gonioscopy, optic disc assessment and visual field defects. Logistic regression model and receiver operating curve (ROC were calculated for predictors of type of glaucoma. Results: Eight hundred and fourteen patients (1603 eyes; males: 380, females: 434 were diagnosed to have various subtypes of angle closure. Mean (±SD age at presentation was significantly higher for males (57.57 ± 11.62 years as compared to females (53.64 ± 10.67 years ( P < 0001. Primary angle closure glaucoma (PACG was most frequently diagnosed subtype (49.38% followed by Primary angle closure (PAC (39.68% and Primary angle closure suspect (PACS (10.93% respectively. The three subtypes differed significantly among their mean IOP (on ANOVA, F = 14.04; P < 0001 using Greenhouse-Geisser correction. Univariate analysis was done to find significant predictors for the outcome of PACG. Logistic regression model and ROC containing the significant predictors yielded a very high AUC of 0.93 with strong discriminatory ability for PACG. Conclusion: In our hospital-based study, the significant predictors for the outcome of PACG included male gender, diminution of vision, the presence of pain and worsening grades of BCVA. Nearly half of PACG presented with advanced disease. In spite of one-third of the patients being diagnosed as angle closure prior to referral, only 8.34% had iridotomy (laser or surgical

  7. Post-closure resaturation of a deep radioactive waste repository

    International Nuclear Information System (INIS)

    Cox, I.C.S.; Rodwell, W.R.

    1989-03-01

    The post-closure resaturation of a deep radioactive waste repository has been modelled for a number of generic disposal concepts. A combination of numerical ground water flow simulations and analytical calculations has been used to investigate the variation of repository fluid pressure and degree of water saturation with time, and to determine the factors influencing resaturation times. The host rock permeability was found to be the most important determining factor. For geological environments regarded as likely for a waste repository, resaturation is predicted to be a short term process compared with gas generation and contaminant migration timescales. (author)

  8. Performance Assessment of a Post-Closure Pyrophoric Event

    International Nuclear Information System (INIS)

    Duguid, J.O.; Senger, R.K.; Leem, J.

    2002-01-01

    This paper describes analyses of a potential post-closure pyrophoric event in a waste package containing uranium metal spent fuel. The analyses include temperature at adjacent waste packages caused by the event and the dose to humans due to the event. The thermal analyses show that the event would not be expected to damage the adjacent waste packages. The dose analyses show that the doses due to the event are small. These analyses provide support to screening arguments used to demonstrate that the pyrophoric event should not be considered in the total system performance assessment model

  9. Opening up closure. Semiotics across scales

    Science.gov (United States)

    Lemke

    2000-01-01

    The dynamic emergence of new levels of organization in complex systems is related to the semiotic reorganization of discrete/continuous variety at the level below as continuous/discrete meaning for the level above. In this view both the semiotic and the dynamic closure of system levels is reopened to allow the development and evolution of greater complexity.

  10. VACUUM ASSISTED CLOSURE IN DIABETIC FOOT MANAGEMENT

    OpenAIRE

    Moganakannan; `Prema; Arun Sundara Rajan

    2014-01-01

    Comparision of vacuum assisted closure vs conventional dressing in management of diabetic foot patients. 30 patients were taken in that 15 underwent vacuum therapy and remaining 15 underwent conventional dressing.They were analysed by the development of granulation tissue and wound healing.The study showed Vac therapy is the best modality for management of diabetic foot patients.

  11. Spontaneous closure of traumatic CSF otorrhoea following ...

    African Journals Online (AJOL)

    We present a 40 year-old male who sustained a head injury with left cerebrospinal fluid otorrhoea following a road traffic accident. Plain radiograph revealed a defect in the temporal bone extending in to the tympanomastoid area. Patient was managed conservatively with closure of the fistula and resolution of the leakage ...

  12. School choice, segregation, and forced school closure

    NARCIS (Netherlands)

    Ong, C.; de Witte, K.

    2014-01-01

    We exploit the forced closure of three segregated primary schools in Amsterdam to establish the determinants of school choice of ethnic minority pupils. The schools were closed due to mismanagement and poor assessment from the Education Inspectorate. Most of the affected students were of socially

  13. Transcatheter Device Closure of Patent Ductus Arteriosus

    International Nuclear Information System (INIS)

    Sultan, M.; Ullah, M.; Sadiq, N.; Akhtar, K.; Akbar, H.

    2014-01-01

    Objective: To determine the efficacy, safety and immediate complications encountered during percutaneous device closure of patent ductus arteriosus (PDA). Study Design: Case series. Place and Duration of Study: Department of Paediatric Cardiology, AFIC/NIHD, Rawalpindi, from January 2005 to December 2010. Methodology: Consecutive 500 patients who underwent attempted transcatheter PDA device closure were included in the study. Device type position, success of closure and complications were described as frequency percentage. Results: In 491 cases (98.2%), PDA was successfully occluded including 4 cases (0.8%) where devices were dislodged but retrieved and redeployed in Cath laboratory. PDA occluder devices used in 448 cases (91%) while coils (single or multiple) were used in 42 cases (8.5%) and in one case (0.2%) ASD occluder device was used to occlude the PDA. There were 09 (1.8%) unsuccessful cases, 06 (1.2%) were abandoned as ducts were considered unsuitable for device closure, 02 (0.4%) devices dislodged and needed surgical retrieval and one case (0.2%) was abandoned due to faulty equipment. The narrowest PDA diameter ranged from 0.5 - 14 mm with mean of 4.5 +- 2.4 mm. There was a single (0.2%) mortality. Conclusion: Transcatheter occlusion of PDA by coil or occluder device is an effective therapeutic option with high success rate. Complication rate is low in the hands of skilled operators yet paediatric cardiac surgical back-up cover is mandatory. (author)

  14. Synthesis of azaphenanthridines via anionic ring closure

    DEFF Research Database (Denmark)

    Hansen, Henriette Møller; Lysén, M.; Begtrup, M.

    2005-01-01

    A new and convergent synthesis of azaphenanthridines via an anionic ring closure is reported. Ortho-lithiation/in situ borylation of cyanopyridines produces the corresponding cyanopyridylboronic esters, which undergo a Suzuki-Miyaura cross-coupling to give the key intermediates. Addition of lithium...

  15. Flower opening and closure: a review

    NARCIS (Netherlands)

    Doorn, van W.G.; Meeteren, van U.

    2003-01-01

    Flower opening and closure are traits of a reproductive syndrome, as it allows pollen removal and/or pollination. Various types of opening can be distinguished such as nocturnal and diurnal and single or repetitive. Opening is generally due to cell expansion. Osmotic solute levels increase by the

  16. Complementary techniques of percutaneous closure of ductus ...

    African Journals Online (AJOL)

    Background: Patent Ductus Arteriosus (PDA) is a common cardiac malformation whose treatment locally has been surgical ligation via a lateral thoracotomy. Device closure of the ductus was first performed at the Mater hospital in 1999 in a ten year old male using a five millilitre detachable cook coil. In 2000 the Amplatzer ...

  17. Hexone Storage and Treatment Facility closure plan

    International Nuclear Information System (INIS)

    1992-11-01

    The HSTF is a storage and treatment unit subject to the requirements for the storage and treatment of dangerous waste. Closure is being conducted under interim status and will be completed pursuant to the requirements of Washington State Department of Ecology (Ecology) Dangerous Waste Regulations, Washington Administrative Code (WAC) 173-303-610 and WAC 173-303-640. Because dangerous waste does not include the source, special nuclear, and by-product material components of mixed waste, radionuclides are not within the scope of WAC 173-303 or of this closure plan. The information on radionuclides is provided only for general knowledge where appropriate. The known hazardous/dangerous waste remaining at the site before commencing other closure activities consists of the still vessels, a tarry sludge in the storage tanks, and residual contamination in equipment, piping, filters, etc. The treatment and removal of waste at the HSTF are closure activities as defined in the Resource Conservation and Recovery Act (RCRA) of 1976 and WAC 173-303

  18. Biomechanics Strategies for Space Closure in Deep Overbite

    OpenAIRE

    Harryanto Wijaya; Isnani Jenie; Himawan Halim

    2013-01-01

    Space closure is an interesting aspect of orthodontic treatment related to principles of biomechanics. It should be tailored individually based on patient’s diagnosis and treatment plan. Understanding the space closure biomechanics basis leads to achieve the desired treatment objective. Overbite deepening and losing posterior anchorage are the two most common unwanted side effects in space closure. Conventionally, correction of overbite must be done before space closure resulted in longer tre...

  19. Smoke without fire: nursing facility closures in California, 1997-2001.

    Science.gov (United States)

    Kitchener, Martin; Bostrom, Alan; Harrington, Charlene

    2004-01-01

    This paper draws from a rich longitudinal California data set to analyze the scope and nature of nursing home closures between 1997 and 2001, and to present a Cox proportionate hazards model of the risks of closure that arise from a range of facility and market characteristics. When compared with the sample total of 1,482 facilities operating in the baseline year of 1997, only 56 facilities closed through 2001, involving the loss of 3.8% of facilities and 2,915 beds (2.3%). The multivariate Cox model of factors associated with closure reports that: 1) hospital-based facilities are 600% more likely to close than are free-standing homes; 2) reducing bed size by one standard deviation (52 beds) increases the risk of closure by 460%; 3) facilities with losses of 5% or worse are more than twice as likely to close; and 4) a one-standard deviation increase in the spare bed capacity measure of county competition raises the risk of facility closure by 140%.

  20. Software Review: A program for testing capture-recapture data for closure

    Science.gov (United States)

    Stanley, Thomas R.; Richards, Jon D.

    2005-01-01

    Capture-recapture methods are widely used to estimate population parameters of free-ranging animals. Closed-population capture-recapture models, which assume there are no additions to or losses from the population over the period of study (i.e., the closure assumption), are preferred for population estimation over the open-population models, which do not assume closure, because heterogeneity in detection probabilities can be accounted for and this improves estimates. In this paper we introduce CloseTest, a new Microsoft® Windows-based program that computes the Otis et al. (1978) and Stanley and Burnham (1999) closure tests for capture-recapture data sets. Information on CloseTest features and where to obtain the program are provided.

  1. Permanent Closure of the TAN-664 Underground Storage Tank

    Energy Technology Data Exchange (ETDEWEB)

    Bradley K. Griffith

    2011-12-01

    This closure package documents the site assessment and permanent closure of the TAN-664 gasoline underground storage tank in accordance with the regulatory requirements established in 40 CFR 280.71, 'Technical Standards and Corrective Action Requirements for Owners and Operators of Underground Storage Tanks: Out-of-Service UST Systems and Closure.'

  2. 10 CFR 60.51 - License amendment for permanent closure.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false License amendment for permanent closure. 60.51 Section 60.51 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) DISPOSAL OF HIGH-LEVEL RADIOACTIVE WASTES IN GEOLOGIC REPOSITORIES Licenses Permanent Closure § 60.51 License amendment for permanent closure. (a) DOE...

  3. Weighted abdominal traction for assistance in abdominal closure

    Directory of Open Access Journals (Sweden)

    Wendy Jo Svetanoff

    2018-02-01

    Discussion: One of the concerns with temporary abdominal closure is retraction of the fascia. We report three cases where the fascia and abdominal wall were placed on weighted traction, which allowed for retention of abdominal domain and delayed primary closure without grafts or mesh. This approach adds to the options available to aid in closure of the complex abdomen.

  4. The potential migration effect of rural hospital closures

    DEFF Research Database (Denmark)

    Sørensen, Jens Fyhn Lykke

    2008-01-01

    Rural hospital closures are high on the current health care agenda in Denmark. One raised concern is that rural hospital closures may further decrease population numbers in rural areas, as closures may induce some residents to move away from affected areas, i.e. closer to health care services els...

  5. Delayed physeal closure associated with castration in cats

    International Nuclear Information System (INIS)

    May, C.; Bennett, D.; Downham, D.Y.

    1991-01-01

    Radiographs of 152 cats under four years of age were examined for evidence of physeal closure. Radiographic closure was compared between entire male, castrated male, and female (neutered and entire] cats. Physeal closure in castrated males was delayed when compared to that of entire males

  6. Risk and Performance Analyses Supporting Closure of WMA C at the Hanford Site in Southeast Washington

    International Nuclear Information System (INIS)

    Eberlein, Susan J.; Bergeron, Marcel P.; Kemp, Christopher J.; Hildebrand, R. Douglas; Aly, Alaa; Kozak, Matthew; Mehta, Sunil; Connelly, Michael

    2013-01-01

    The Office of River Protection under the U.S. Department of Energy (DOE) is pursuing closure of the Single-Shell Tank (SST) Waste Management Area (WMA) C as stipulated by the Hanford Federal Facility Agreement and Consent Order (HFFACO) under federal requirements and work tasks will be done under the State-approved closure plans and permits. An initial step in meeting the regulatory requirements is to develop a baseline risk assessment representing current conditions based on available characterization data and information collected at the WMA C location. The baseline risk assessment will be supporting a Resource Conservation and Recovery Act of 1976 (RCRA) Field Investigation (RFI)/Corrective Measures Study (CMS) for WMA closure and RCRA corrective action. Complying with the HFFACO conditions also involves developing a long-term closure Performance Assessment (PA) that evaluates human health and environmental impacts resulting from radionuclide inventories in residual wastes remaining in WMA C tanks and ancillary equipment. This PA is being developed to meet the requirements necessary for closure authorization under DOE Order 435.1 and Washington State Hazardous Waste Management Act. To meet the HFFACO conditions, the long-term closure risk analysis will include an evaluation of human health and environmental impacts from hazardous chemical inventories along with other performance Comprehensive Environmental Response, Compensation, and Liability Act Appropriate and Applicable Requirements (CERCLA ARARs) in residual wastes left in WMA C facilities after retrieval and removal. This closure risk analysis is needed to needed to comply with the requirements for permitted closure. Progress to date in developing a baseline risk assessment of WMA C has involved aspects of an evaluation of soil characterization and groundwater monitoring data collected as a part of the RFI/CMS and RCRA monitoring. Developing the long-term performance assessment aspects has involved the

  7. Risk and Performance Analyses Supporting Closure of WMA C at the Hanford Site in Southeast Washington

    Energy Technology Data Exchange (ETDEWEB)

    Eberlein, Susan J.; Bergeron, Marcel P.; Kemp, Christopher J.

    2013-11-11

    The Office of River Protection under the U.S. Department of Energy (DOE) is pursuing closure of the Single-Shell Tank (SST) Waste Management Area (WMA) C as stipulated by the Hanford Federal Facility Agreement and Consent Order (HFFACO) under federal requirements and work tasks will be done under the State-approved closure plans and permits. An initial step in meeting the regulatory requirements is to develop a baseline risk assessment representing current conditions based on available characterization data and information collected at the WMA C location. The baseline risk assessment will be supporting a Resource Conservation and Recovery Act of 1976 (RCRA) Field Investigation (RFI)/Corrective Measures Study (CMS) for WMA closure and RCRA corrective action. Complying with the HFFACO conditions also involves developing a long-term closure Performance Assessment (PA) that evaluates human health and environmental impacts resulting from radionuclide inventories in residual wastes remaining in WMA C tanks and ancillary equipment. This PA is being developed to meet the requirements necessary for closure authorization under DOE Order 435.1 and Washington State Hazardous Waste Management Act. To meet the HFFACO conditions, the long-term closure risk analysis will include an evaluation of human health and environmental impacts from hazardous chemical inventories along with other performance Comprehensive Environmental Response, Compensation, and Liability Act Appropriate and Applicable Requirements (CERCLA ARARs) in residual wastes left in WMA C facilities after retrieval and removal. This closure risk analysis is needed to needed to comply with the requirements for permitted closure. Progress to date in developing a baseline risk assessment of WMA C has involved aspects of an evaluation of soil characterization and groundwater monitoring data collected as a part of the RFI/CMS and RCRA monitoring. Developing the long-term performance assessment aspects has involved the

  8. Comparison of fasciotomy wound closures using traditional dressing changes and the vacuum-assisted closure device.

    Science.gov (United States)

    Zannis, John; Angobaldo, Jeff; Marks, Malcolm; DeFranzo, Anthony; David, Lisa; Molnar, Joseph; Argenta, Louis

    2009-04-01

    Fasciotomy wounds can be a major contributor to length of stay for patients as well as a difficult reconstructive challenge. Once the compartment pressure has been relieved and stabilized, the wound should be closed as quickly and early as possible to avoid later complications. Skin grafting can lead to morbidity and scarring at both the donor and fasciotomy site. Primary closure results in a more functional and esthetic outcome with less morbidity for the patient, but can often be difficult to achieve secondary to edema, skin retraction, and skin edge necrosis. Our objective was to examine fasciotomy wound outcomes, including time to definitive closure, comparing traditional wet-to-dry dressings, and the vacuum-assisted closure (VAC) device. This retrospective chart review included a consecutive series of patients over a 10-year period. This series included 458 patients who underwent 804 fasciotomies. Of these fasciotomy wounds, 438 received exclusively VAC. dressings, 270 received only normal saline wet-to-dry dressings, and 96 were treated with a combination of both. Of the sample, 408 patients were treated with exclusively VAC therapy or wet-to-dry dressings and 50 patients were treated with a combination of both. In comparing all wounds, there was a statistically significant higher rate of primary closure using the VAC versus traditional wet-to-dry dressings (P lower extremities and P extremities). The time to primary closure of wounds was shorter in the VAC. group in comparison with the non-VAC group. This study has shown that the use of the VAC for fasciotomy wound closure results in a higher rate of primary closure versus traditional wet-to-dry dressings. In addition, the time to primary closure of wounds or time to skin grafting is shorter when the VAC was employed. The VAC used in the described settings decreases hospitalization time, allows for earlier rehabilitation, and ultimately leads to increased patient satisfaction.

  9. Force-closure grasping with two hands

    Science.gov (United States)

    Caraza, Jose-Antonio Navarro

    1991-02-01

    This thesis addresses grasping of large (but not necessarily heavy) objects by using two hands. The objective is to determine force-closure grasps of rigid objects of unknown shape. A grasp is force-closure if it can completely constrain the movement of the object. In seeking force-closure conditions, the approach taken in this study is to establish useful sufficient conditions rather than necessary and sufficient conditions since the later requires the complete knowledge of the contact parameters. Based on the friction coefficient between hands and object, and on the grasp configuration (defined as the relative position and orientation of fingers and palms), a sufficient condition under which the two hands form a force-closure grasp has been established. The salient feature of this approach is that shape, orientation and location of the object, and contact points location are not assumed in this condition. This makes it possible to use simple sensors and algorithms. A configuration of two hands in contact with the object satisfying this condition is called force-closure grasp configuration (FCGC). The two hands in a FCGC are capable of picking up and moving the object by applying appropriate forces. The two-dimensional (2-D) case is initially studied. Later, the study is extended to the three-dimensional (3-D) case. The hands considered are either flat-surface palms or grippers with two angular-motion fingers. An algorithm has been developed to check the condition for FCGC in terms of the position and orientation of the hands. The algorithm was implemented on TRACS, an experimental multiagent robotic system developed at the GRASP Laboratory at the University of Pennsylvania. The results obtained are readily applicable to grasping large but lightweight objects. The simplicity of the conditions and the practical assumptions make it feasible to implement these results in real time.

  10. Device Closure of Patent Foramen Ovale after Stroke: Pooled Analysis of Completed Randomized Trials

    Science.gov (United States)

    Kent, David M.; Dahabreh, Issa J.; Ruthazer, Robin; Furlan, Anthony J.; Reisman, Mark; Carroll, John D.; Saver, Jeffrey L.; Smalling, Richard W.; Jüni, Peter; Mattle, Heinrich P.; Meier, Bernhard; Thaler, David E

    2015-01-01

    Background The comparative effectiveness of percutaneous closure of patent foramen ovale (PFO) plus medical therapy versus medical therapy alone for cryptogenic stroke is uncertain. Objectives We performed the first pooled analysis of individual participant data from completed randomized trials comparing PFO closure versus medical therapy in patients with cryptogenic stroke. Methods We analyzed data on 2 devices (STARFlex and Amplatzer PFO Occluder) evaluated in 3 trials. The primary composite outcome was stroke, transient ischemic attack (TIA), or death; the secondary outcome was stroke. We used log-rank tests and (unadjusted and covariate-adjusted) Cox regression models to compare device closure versus medical therapy. Results Among 2,303 patients, closure was not significantly associated with the primary composite outcome. The difference became significant after covariate adjustment (hazard ratio [HR]: 0.68; p = 0.049). For the outcome of stroke, all comparisons were statistically significant, with unadjusted and adjusted HRs of 0.58 (p = 0.043) and 0.58 (p = 0.044), respectively. In analyses limited to the 2 occluder device trials, the effect of closure was not significant for the composite outcome, but was for the stroke outcome (unadjusted HR: 0.39; p = 0.013. Subgroup analyses did not identify significant heterogeneity of treatment effects. Atrial fibrillation was more common among closure patients. Conclusions Among patients with PFO and cryptogenic stroke, closure reduced recurrent stroke and had a statistically significant effect on the composite of stroke, TIA, and death in adjusted but not unadjusted analyses. PMID:26916479

  11. Tools for Closure Project and Contract Management: Development of the Rocky Flats Integrated Closure Project Baseline

    International Nuclear Information System (INIS)

    Gelles, C. M.; Sheppard, F. R.

    2002-01-01

    This paper details the development of the Rocky Flats Integrated Closure Project Baseline - an innovative project management effort undertaken to ensure proactive management of the Rocky Flats Closure Contract in support of the Department's goal for achieving the safe closure of the Rocky Flats Environmental Technology Site (RFETS) in December 2006. The accelerated closure of RFETS is one of the most prominent projects within the Department of Energy (DOE) Environmental Management program. As the first major former weapons plant to be remediated and closed, it is a first-of-kind effort requiring the resolution of multiple complex technical and institutional challenges. Most significantly, the closure of RFETS is dependent upon the shipment of all special nuclear material and wastes to other DOE sites. The Department is actively working to strengthen project management across programs, and there is increasing external interest in this progress. The development of the Rocky Flats Integrated Closure Project Baseline represents a groundbreaking and cooperative effort to formalize the management of such a complex project across multiple sites and organizations. It is original in both scope and process, however it provides a useful precedent for the other ongoing project management efforts within the Environmental Management program

  12. Preliminary creep and pillar closure data for shales

    International Nuclear Information System (INIS)

    Lomenick, T.F.; Russell, J.E.

    1987-10-01

    The results of fourteen laboratory creep tests on model pillars of four different shales are reported. Initial pillar stresses range from 6.9 MPa (1000 psi) to 69 MPa (10,000 psi) and temperatures range from ambient to 100 0 C. Laboratory response data are used to evaluate the parameters in the transient power-law pillar closure equation similar to that previously used for model pillars of rock salt. The response of the model pillars of shale shows many of the same characteristics as for rock salt. Deformation is enhanced by higher stresses and temperatures, although the shale pillars are not as sensitive to either stress or temperature as are pillars of rock salt. These test results must be considered very preliminary since they represent the initial, or scoping, phase of a comprehensive model pillar test program that will lead to the development and validation of creep laws for clay-rich rocks. 11 refs., 9 figs., 7 tabs

  13. Creep closure of an opening in a deep potash mine

    International Nuclear Information System (INIS)

    Montgomery, S.T.

    1983-01-01

    The creep closure of an isolated opening in a deep potash mine at Esterhazy, Canada, has been simulated with finite element calculations. These were done to assess the plausibility of a creep model, developed from laboratory data, for natural rock salt. Since it is difficult to generate and interpret creep data at the low stresses likely to be encountered around underground excavations, the comparison of field measurements with model predictions is valuable in establishing the plausibility of constitutive models for creep over a long time at low stresses. The favorable comparison obtained in this study, between predicted wall convergences, and those measured over a period of eight years in the opening at Esterhazy, helps verify the creep model used. 2 figures

  14. Temporary Closure of the Open Abdomen: A Systematic Review on Delayed Primary Fascial Closure in Patients with an Open Abdomen

    NARCIS (Netherlands)

    Boele van Hensbroek, Pieter; Wind, Jan; Dijkgraaf, Marcel G. W.; Busch, Olivier R. C.; Goslings, J. Carel

    2009-01-01

    Background This study was designed to systematically review the literature to assess which temporary abdominal closure (TAC) technique is associated with the highest delayed primary fascial closure (FC) rate. In some cases of abdominal trauma or infection, edema or packing precludes fascial closure

  15. Resource Conservation and Recovery Act Closure Plan for the Y-12 9409-5 Tank Storage Facility

    International Nuclear Information System (INIS)

    1995-02-01

    This document presents information on the closure of the Y-12 9409-5 Tank Storage Facility. Topics discussed include: facility description; closure history; closure performance standard; partial closure; maximum waste inventory; closure activities; schedule; and postclosure care

  16. Comparison of maximum entropy and quadrature-based moment closures for shock transitions prediction in one-dimensional gaskinetic theory

    Science.gov (United States)

    Laplante, Jérémie; Groth, Clinton P. T.

    2016-11-01

    The Navier-Stokes-Fourier (NSF) equations are conventionally used to model continuum flow near local thermodynamic equilibrium. In the presence of more rarefied flows, there exists a transitional regime in which the NSF equations no longer hold, and where particle-based methods become too expensive for practical problems. To close this gap, moment closure techniques having the potential of being both valid and computationally tractable for these applications are sought. In this study, a number of five-moment closures for a model one-dimensional kinetic equation are assessed and compared. In particular, four different moment closures are applied to the solution of stationary shocks. The first of these is a Grad-type moment closure, which is known to fail for moderate departures from equilibrium. The second is an interpolative closure based on maximization of thermodynamic entropy which has previously been shown to provide excellent results for 1D gaskinetic theory. Additionally, two quadrature methods of moments (QMOM) are considered. One method is based on the representation of the distribution function in terms of a combination of three Dirac delta functions. The second method, an extended QMOM (EQMOM), extends the quadrature-based approach by assuming a bi-Maxwellian representation of the distribution function. The closing fluxes are analyzed in each case and the region of physical realizability is examined for the closures. Numerical simulations of stationary shock structures as predicted by each moment closure are compared to reference kinetic and the corresponding NSF-like equation solutions. It is shown that the bi-Maxwellian and interpolative maximum-entropy-based moment closures are able to closely reproduce the results of the true maximum-entropy distribution closure for this case very well, whereas the other methods do not. For moderate departures from local thermodynamic equilibrium, the Grad-type and QMOM closures produced unphysical subshocks and were

  17. Multi-purpose canister closure and welding: Potential automation and impacts

    International Nuclear Information System (INIS)

    Bennett, P.C.; Stringer, J.B.

    1995-01-01

    This paper describes the simulation of robotic closure and welding of multi-purpose canisters (MPCs) loaded with spent fuels. IGRIP simulation software was used to model the dimensional and kinematic characteristics of the robot, equipment, and MPC. A cost/benefit analysis was prepared, comparing manual and remote practices. Simulation of robotic closure and welding indicated the technical feasibility of automation. Benefit/cost analysis indicated the possibility of dose reductions of 6100 Rem and savings up to $274 million over a 30-year operational period with remote methods

  18. Relationships between basin architecture, basin closure, and occurrence of sulphide-bearing schists

    DEFF Research Database (Denmark)

    Kalliomäki, Henrik; Torvela, Taija; Moreau, Julien

    2014-01-01

    We present field observations from the Palaeoproterozoic volcano-sedimentary Tampere palaeobasin, where the primary structures have been exceptionally well preserved. We use the observations to construct a new tectonic model for the southeastern margin of the Tampere basin during its inversion...... and subsequent closure. The observed volcano-sedimentary and structural features suggest a change in the local structural style from thick-skinned inversion to thin-skinned thrusting, in order to accommodate the crustal shortening during basin closure. Furthermore, it is suggested that there is a genetic...

  19. The merits of non-tradable quotas as a domestic policy instrument to prevent firm closure

    International Nuclear Information System (INIS)

    Hagem, Cathrine

    2001-05-01

    There is a concern in many countries that a domestic tradable quota system for greenhouse gases, where all emitters must pay for their quotas, may lead to closures of emissions-intensive industrial companies. Allocating quotas free of charge to companies operating in competitive markets has been suggested as a means to reduce the likelihood of closures. Two different designs of quota systems are studied within a two-period model: one where the quotas given free of charge are tradable, and one where the quotas are non-tradable. The two quota systems are compared with respect to their ability both to induce the firms to implement investment in abatement technology and to prevent or postpone closures. (author)

  20. Study of relationship between clinical factors and velopharyngeal closure in cleft palate patients

    Science.gov (United States)

    Chen, Qi; Zheng, Qian; Shi, Bing; Yin, Heng; Meng, Tian; Zheng, Guang-ning

    2011-01-01

    BACKGROUND: This study was carried out to analyze the relationship between clinical factors and velopharyngeal closure (VPC) in cleft palate patients. METHODS: Chi-square test was used to compare the postoperative velopharyngeal closure rate. Logistic regression model was used to analyze independent variables associated with velopharyngeal closure. RESULTS: Difference of postoperative VPC rate in different cleft types, operative ages and surgical techniques was significant (P=0.000). Results of logistic regression analysis suggested that when operative age was beyond deciduous dentition stage, or cleft palate type was complete, or just had undergone a simple palatoplasty without levator veli palatini retropositioning, patients would suffer a higher velopharyngeal insufficiency rate after primary palatal repair. CONCLUSIONS: Cleft type, operative age and surgical technique were the contributing factors influencing VPC rate after primary palatal repair of cleft palate patients. PMID:22279464

  1. Application of electron closures in extended MHD

    Science.gov (United States)

    Held, Eric; Adair, Brett; Taylor, Trevor

    2017-10-01

    Rigorous closure of the extended MHD equations in plasma fluid codes includes the effects of electron heat conduction along perturbed magnetic fields and contributions of the electron collisional friction and stress to the extended Ohms law. In this work we discuss application of a continuum numerical solution to the Chapman-Enskog-like electron drift kinetic equation using the NIMROD code. The implementation is a tightly-coupled fluid/kinetic system that carefully addresses time-centering in the advance of the fluid variables with their kinetically-computed closures. Comparisons of spatial accuracy, computational efficiency and required velocity space resolution are presented for applications involving growing magnetic islands in cylindrical and toroidal geometry. The reduction in parallel heat conduction due to particle trapping in toroidal geometry is emphasized. Work supported by DOE under Grant Nos. DE-FC02-08ER54973 and DE-FG02-04ER54746.

  2. Post-closure performance assessment treatment of the biosphere

    International Nuclear Information System (INIS)

    Broderick, M.A.; Egan, M.J.; Thorne, M.C.; Williams, J.A.

    1996-01-01

    The Nirex strategy for radioactive waste disposal is based on a system of engineered and natural barriers, providing long-term isolation of the waste from those parts of the environment that are in contact with or readily available for use by humans (i.e. the biosphere). Even so, there remains the possibility that, on a timescale of thousands to tens of thousands of years, small quantities of poorly-sorbed, long-lived radionuclides may be released from the engineered disposal system, ultimately to emerge into the biosphere. Biosphere models are used in post-closure performance assessments to quantify the competing effects of dilution and accumulation processes on radionuclide concentrations in the accessible environment. Understanding biosphere processes and their time dependence is necessary not only to determine the radiological impact of possible future releases, but also to characterise the dynamics of transport in groundwater and the location, duration and extent of any such releases. Nirex is developing a new biosphere model for use in post-closure radiological assessments for the proposed Sellafield repository. A compartment modelling approach has been adopted, as in studies performed previously, but the system will be dynamic, allowing changes with time in both the properties of compartments and the transfers between compartments. The transport model considers both mass transport within the biosphere and the migration of radionuclides, thereby ensuring that a self-consistent description of the biosphere, in a spatially-extensive domain is maintained. The above approach is designed to link the assessment models used by the Nirex assessment team more closely into the Nirex biosphere research programme than has hitherto been possible with time-invariant assessment models. (author)

  3. Calcined solids storage facility closure study

    Energy Technology Data Exchange (ETDEWEB)

    Dahlmeir, M.M.; Tuott, L.C.; Spaulding, B.C. [and others

    1998-02-01

    The disposal of radioactive wastes now stored at the Idaho National Engineering and Environmental Laboratory is currently mandated under a {open_quotes}Settlement Agreement{close_quotes} (or {open_quotes}Batt Agreement{close_quotes}) between the Department of Energy and the State of Idaho. Under this agreement, all high-level waste must be treated as necessary to meet the disposal criteria and disposed of or made road ready to ship from the INEEL by 2035. In order to comply with this agreement, all calcined waste produced in the New Waste Calcining Facility and stored in the Calcined Solids Facility must be treated and disposed of by 2035. Several treatment options for the calcined waste have been studied in support of the High-Level Waste Environmental Impact Statement. Two treatment methods studied, referred to as the TRU Waste Separations Options, involve the separation of the high-level waste (calcine) into TRU waste and low-level waste (Class A or Class C). Following treatment, the TRU waste would be sent to the Waste Isolation Pilot Plant (WIPP) for final storage. It has been proposed that the low-level waste be disposed of in the Tank Farm Facility and/or the Calcined Solids Storage Facility following Resource Conservation and Recovery Act closure. In order to use the seven Bin Sets making up the Calcined Solids Storage Facility as a low-level waste landfill, the facility must first be closed to Resource Conservation and Recovery Act (RCRA) standards. This study identifies and discusses two basic methods available to close the Calcined Solids Storage Facility under the RCRA - Risk-Based Clean Closure and Closure to Landfill Standards. In addition to the closure methods, the regulatory requirements and issues associated with turning the Calcined Solids Storage Facility into an NRC low-level waste landfill or filling the bin voids with clean grout are discussed.

  4. Calcined solids storage facility closure study

    International Nuclear Information System (INIS)

    Dahlmeir, M.M.; Tuott, L.C.; Spaulding, B.C.

    1998-02-01

    The disposal of radioactive wastes now stored at the Idaho National Engineering and Environmental Laboratory is currently mandated under a open-quotes Settlement Agreementclose quotes (or open-quotes Batt Agreementclose quotes) between the Department of Energy and the State of Idaho. Under this agreement, all high-level waste must be treated as necessary to meet the disposal criteria and disposed of or made road ready to ship from the INEEL by 2035. In order to comply with this agreement, all calcined waste produced in the New Waste Calcining Facility and stored in the Calcined Solids Facility must be treated and disposed of by 2035. Several treatment options for the calcined waste have been studied in support of the High-Level Waste Environmental Impact Statement. Two treatment methods studied, referred to as the TRU Waste Separations Options, involve the separation of the high-level waste (calcine) into TRU waste and low-level waste (Class A or Class C). Following treatment, the TRU waste would be sent to the Waste Isolation Pilot Plant (WIPP) for final storage. It has been proposed that the low-level waste be disposed of in the Tank Farm Facility and/or the Calcined Solids Storage Facility following Resource Conservation and Recovery Act closure. In order to use the seven Bin Sets making up the Calcined Solids Storage Facility as a low-level waste landfill, the facility must first be closed to Resource Conservation and Recovery Act (RCRA) standards. This study identifies and discusses two basic methods available to close the Calcined Solids Storage Facility under the RCRA - Risk-Based Clean Closure and Closure to Landfill Standards. In addition to the closure methods, the regulatory requirements and issues associated with turning the Calcined Solids Storage Facility into an NRC low-level waste landfill or filling the bin voids with clean grout are discussed

  5. Stochastic particle acceleration and statistical closures

    International Nuclear Information System (INIS)

    Dimits, A.M.; Krommes, J.A.

    1985-10-01

    In a recent paper, Maasjost and Elsasser (ME) concluded, from the results of numerical experiments and heuristic arguments, that the Bourret and the direct-interaction approximation (DIA) are ''of no use in connection with the stochastic acceleration problem'' because (1) their predictions were equivalent to that of the simpler Fokker-Planck (FP) theory, and (2) either all or none of the closures were in good agreement with the data. Here some analytically tractable cases are studied and used to test the accuracy of these closures. The cause of the discrepancy (2) is found to be the highly non-Gaussian nature of the force used by ME, a point not stressed by them. For the case where the force is a position-independent Ornstein-Uhlenbeck (i.e., Gaussian) process, an effective Kubo number K can be defined. For K << 1 an FP description is adequate, and conclusion (1) of ME follows; however, for K greater than or equal to 1 the DIA behaves much better qualitatively than the other two closures. For the non-Gaussian stochastic force used by ME, all common approximations fail, in agreement with (2)

  6. Candida and Porphyromonas gingivalis: the effect on wound closure in vitro

    NARCIS (Netherlands)

    Haverman, Thijs M.; Laheij, Alexa M. G. A.; de Soet, Johannes J.; de Lange, Jan; Rozema, Frederik R.

    2017-01-01

    Microorganisms play a role in oral mucositis after cancer therapy. The current study explored the hypothesis that Candida spp. alone and together with Porphyromonas gingivalis cause delayed healing of oral ulcerations due to the inhibition of wound closure. An in vitro scratch assay model was used

  7. Fernald - Developing and Executing an Accelerated Closure Plan

    International Nuclear Information System (INIS)

    Nixon, D.A.

    2006-01-01

    In November 2000 the Department of Energy (DOE) and Fluor Fernald entered into a closure contract that incited Fluor Fernald to reduce the cost and schedule of the Fernald site cleanup. The contract established a target schedule and target cost and how Fluor Fernald performs against these targets determines the amount of fee the company earns. In response to these new challenges, Fluor Fernald developed a 13-part strategy to safely accelerate work and more efficiently utilize the available funding. Implementation of this strategy required a dramatic culture change at Fernald - from a 'government job mind set' to an entrepreneurial/commercial model. Fluor Fernald's strategy and culture change has proved to be successful as the company is on track to close the site ahead of the target schedule at a total project cost less than the target cost. The elements of Fluor Fernald's strategy and the lessons learned during implementation provide valuable information that could be utilized by other DOE sites that will be undergoing closure over the next decade. (authors)

  8. Hylomorphism and the metabolic closure conception of life.

    Science.gov (United States)

    DiFrisco, James

    2014-12-01

    This paper examines three exemplary theories of living organization with respect to their common feature of defining life in terms of metabolic closure: autopoiesis, (M, R) systems, and chemoton theory. Metabolic closure is broadly understood to denote the property of organized chemical systems that each component necessary for the maintenance of the system is produced from within the system itself, except for an input of energy. It is argued that two of the theories considered--autopoiesis and (M, R) systems--participate in a hylomorphist pattern of thinking which separates the "form" of the living system from its "matter." The analysis and critique of hylomorphism found in the work of the philosopher Gilbert Simondon is then applied to these two theories, and on the basis of this critique it is argued that the chemoton model offers a superior theory of minimal life which overcomes many of the problems associated with the other two. Throughout, the relationship between hylomorphism and the understanding of living things as machines is explored. The paper concludes by considering how hylomorphism as a background ontology for theories of life fundamentally influences the way life is defined.

  9. Femoral Artery Stenosis Following Percutaneous Closure Using a Starclose Closure Device

    International Nuclear Information System (INIS)

    Bent, Clare Louise; Kyriakides, Constantinos; Matson, Matthew

    2008-01-01

    Starclose (Abbott Vascular Devices, Redwood City, CA) is a new arterial closure device that seals a femoral puncture site with an extravascular star-shaped nitinol clip. The clip projects small tines into the arterial wall which fold inward, causing the arterial wall to pucker, producing a purse-string-like seal closing the puncture site. The case history is that of a 76-year-old female patient who underwent day-case percutaneous diagnostic coronary angiography. A Starclose femoral artery closure device was used to achieve hemostasis with subsequent femoral artery stenosis.

  10. Modelling turbulent vertical mixing sensitivity using a 1-D version of NEMO

    Science.gov (United States)

    Reffray, G.; Bourdalle-Badie, R.; Calone, C.

    2015-01-01

    Through two numerical experiments, a 1-D vertical model called NEMO1D was used to investigate physical and numerical turbulent-mixing behaviour. The results show that all the turbulent closures tested (k+l from Blanke and Delecluse, 1993, and two equation models: generic length scale closures from Umlauf and Burchard, 2003) are able to correctly reproduce the classical test of Kato and Phillips (1969) under favourable numerical conditions while some solutions may diverge depending on the degradation of the spatial and time discretization. The performances of turbulence models were then compared with data measured over a 1-year period (mid-2010 to mid-2011) at the PAPA station, located in the North Pacific Ocean. The modelled temperature and salinity were in good agreement with the observations, with a maximum temperature error between -2 and 2 °C during the stratified period (June to October). However, the results also depend on the numerical conditions. The vertical RMSE varied, for different turbulent closures, from 0.1 to 0.3 °C during the stratified period and from 0.03 to 0.15 °C during the homogeneous period. This 1-D configuration at the PAPA station (called PAPA1D) is now available in NEMO as a reference configuration including the input files and atmospheric forcing set described in this paper. Thus, all the results described can be recovered by downloading and launching PAPA1D. The configuration is described on the NEMO site (PAPA">http://www.nemo-ocean.eu/Using-NEMO/Configurations/C1D_PAPA). This package is a good starting point for further investigation of vertical processes.

  11. 3718-F Alkali Metal Treatment and Storage Facility Closure Plan

    Energy Technology Data Exchange (ETDEWEB)

    None

    1991-12-01

    Since 1987, Westinghouse Hanford Company has been a major contractor to the U.S. Department of Energy-Richland Operations Office and has served as co-operator of the 3718-F Alkali Metal Treatment and Storage Facility, the waste management unit addressed in this closure plan. The closure plan consists of a Part A Dangerous waste Permit Application and a RCRA Closure Plan. An explanation of the Part A Revision (Revision 1) submitted with this document is provided at the beginning of the Part A section. The closure plan consists of 9 chapters and 5 appendices. The chapters cover: introduction; facility description; process information; waste characteristics; groundwater; closure strategy and performance standards; closure activities; postclosure; and references.

  12. 3718-F Alkali Metal Treatment and Storage Facility Closure Plan

    International Nuclear Information System (INIS)

    1991-12-01

    Since 1987, Westinghouse Hanford Company has been a major contractor to the U.S. Department of Energy-Richland Operations Office and has served as co-operator of the 3718-F Alkali Metal Treatment and Storage Facility, the waste management unit addressed in this closure plan. The closure plan consists of a Part A Dangerous waste Permit Application and a RCRA Closure Plan. An explanation of the Part A Revision (Revision 1) submitted with this document is provided at the beginning of the Part A section. The closure plan consists of 9 chapters and 5 appendices. The chapters cover: introduction; facility description; process information; waste characteristics; groundwater; closure strategy and performance standards; closure activities; postclosure; and references

  13. Overview of mine closure in Minas Gerais, Brazil

    OpenAIRE

    Castro,Maíra Fonseca Moreira; Lima,Hernani Mota de; Flôres,José Cruz do Carmo

    2011-01-01

    Despite closure regulations being recent in Brazil, many mining companies are attempting to adopt best practice and are facing the challenge of closing their mines properly instead of simply complying with current legislation or abandoning the mine site. This paper summarizes mine closure according to both the Brazilian legislation and the "Deliberação Normativa" COPAM Nº 127, that establishes the directives and procedures for environmental assessment at the mine closure stage. Even with the ...

  14. Vacuum assisted closure in vascular surgery.

    Science.gov (United States)

    Beno, M; Martin, J; Sager, P

    2011-01-01

    Vacuum assisted closure (VAC-therapy) is a well established method in nearly all surgical disciplines. The aim is to present the efficiency of vacuum assisted closure in the treatment of acute and chronic wounds in patients admitted in the department of vascular surgery. Within the year 2008 there were 59 patients (44 men, 15 women) treated with VAC therapy in our Department of Vascular surgery (Landshut, Germany). VAC was used 22x (37.28 %) in therapy of ulcus cruris (venous, arterial, mixed genesis), 15x (25.42%) in patients with diabetic foot syndrome, 12x (20.33%) in secondary healing wounds and infected wounds, 5x (8.47%) in wounds after several injuries and soft skin tissue infections and 5x (8.47%) in wound infections connected with vascular graft infections after vascular revascularization. VAC therapy seems to be very effective in the management of patients with venous ulcers, especially after a proper surgical treatment (100%), patients with soft skin tissue infections (100%) and secondary healing wounds (100%) especially in combination with MESH-Grafting. In patients with diabetic foot syndrome (80%) and peripheral arterial occlusive disease (72.7%), an evaluation of peripheral blood perfusion and revascularization prior to VAC therapy is often necessary. Although VAC was used 5x in the therapy of infected vascular grafts, successful preservation of infected graft material was observed in only one case (infection of PTFE femoro-popliteal bypass graft). Vacuum assisted closure in vascular surgery proved to be simple and efficient method in therapy of acute and chronic wounds. The efficiency of VAC systems in therapy of infected graft material after revascularization needs further studies (Tab. 3, Ref. 10).

  15. Economic and financial aspects of mine closure

    International Nuclear Information System (INIS)

    Kahn, James R.; Franceschi, Dina; Curi, Adilson; Vale, Eduardo

    2001-01-01

    Today, mine reclamation is a key component to a successful mine plan. Most of the industrialized nations have recognized the need to make mining activities relatively environmentally friendly, if they want to continue to benefit from the economic gains from mineral resource development. Countries such as the United States, Canada, Australia and South Africa are leaders in the field and have implemented relatively sophisticated legislation to ensure environmentally correct mine closure. These countries rely on a combination of strict control strategies and economic penalties to ensure compliance. Yet, from the firm's perspective, reclamation activities are counterproductive as they cut into properties. In order to attract economic development and earn much needed economic capital, most of the rest of the world, particularly the developing countries, lack effective mine closure legislation. The traditional command and control type of legislation that is sometimes used is either vague and therefore avoided, or not enforced appropriately, resulting in an undesirable level of environmental degradation. With the use of case studies from Brazil, this article shows that direct controls are effective in some instances and not in others. It proposes that economic and financial tools may be more effective than the traditional direct controls in getting firms to comply with environmental standards, particularly in developing countries where environmental compliance is more difficult to achieve. It explains the use of performance bonding as one type of economic incentive that has proven to be an effective environmental policy in mine planning and closure. The authors additionally push beyond the typical style of performance bonds to introduce a flexible bonding and insurance system that allows governments to maintain strict environmental standards but limits firms financial exposure during the mining process. Such a system learns from the successes of the industrialized

  16. The Relationship of Financial Pressures and Community Characteristics to Closure of Private Safety Net Clinics.

    Science.gov (United States)

    Li, Suhui; Dor, Avi; Pines, Jesse M; Zocchi, Mark S; Hsia, Renee Y

    2016-10-01

    In order to better understand what threatens vulnerable populations' access to primary care, it is important to understand the factors associated with closing safety net clinics. This article examines how a clinic's financial position, productivity, and community characteristics are associated with its risk of closure. We examine patterns of closures among private-run primary care clinics (PCCs) in California between 2006 and 2012. We use a discrete-time proportional hazard model to assess relative hazard ratios of covariates, and a random-effect hazard model to adjust for unobserved heterogeneity among PCCs. We find that lower net income from patient care, smaller amount of government grants, and lower productivity were associated with significantly higher risk of PCC closure. We also find that federally qualified health centers and nonfederally qualified health centers generally faced the same risk factors of closure. These results underscore the critical role of financial incentives in the long-term viability of safety net clinics. © The Author(s) 2015.

  17. Recurrent Stroke after Transcatheter PFO Closure in Cryptogenic Stroke or Tia: Long-Term Follow-Up

    Directory of Open Access Journals (Sweden)

    Elisabetta Mariucci

    2017-01-01

    Full Text Available Background. There are few data on the mechanism of recurrent neurological events after transcatheter closure of patent foramen ovale (PFO in cryptogenic stroke or TIA. Methods. We retrospectively reviewed PFO closure procedures for the secondary prevention of cryptogenic stroke/TIA performed between 1999 and 2014 in Bologna, Italy. Results. Written questionnaires were completed by 402 patients. Mean follow-up was 7 ± 3 years. Stroke recurred in 3.2% (0.5/100 patients-year and TIA in 2.7% (0.4/100 patients-year. Ninety-two percent of recurrent strokes were not cryptogenic. Recurrent stroke was noncardioembolic in 69% of patients, AF related in 15% of patients, device related in 1 patient, and cryptogenic in 1 patient. AF was diagnosed after the procedure in 21 patients (5.2%. Multivariate Cox’s proportion hazard model identified age ≥ 55 years at the time of closure (OR 3.16, p=0.007 and RoPE score < 7 (OR 3.21, p=0.03 as predictors of recurrent neurological events. Conclusion. Recurrent neurological events after PFO closure are rare, usually noncryptogenic and associated with conventional vascular risk factors or AF related. Patients older than 55 years of age and those with a RoPE score < 7 are likely to get less benefit from PFO closure. After transcatheter PFO closure, lifelong strict vascular risk factor control is warranted.

  18. 100-N Area underground storage tank closures

    Energy Technology Data Exchange (ETDEWEB)

    Rowley, C.A.

    1993-08-01

    This report describes the removal/characterization actions concerning underground storage tanks (UST) at the 100-N Area. Included are 105-N-LFT, 182-N-1-DT, 182-N-2-DT, 182-N-3-DT, 100-N-SS-27, and 100-N-SS-28. The text of this report gives a summary of remedial activities. In addition, correspondence relating to UST closures can be found in Appendix B. Appendix C contains copies of Unusual Occurrence Reports, and validated sampling data results comprise Appendix D.

  19. 100-N Area underground storage tank closures

    International Nuclear Information System (INIS)

    Rowley, C.A.

    1993-01-01

    This report describes the removal/characterization actions concerning underground storage tanks (UST) at the 100-N Area. Included are 105-N-LFT, 182-N-1-DT, 182-N-2-DT, 182-N-3-DT, 100-N-SS-27, and 100-N-SS-28. The text of this report gives a summary of remedial activities. In addition, correspondence relating to UST closures can be found in Appendix B. Appendix C contains copies of Unusual Occurrence Reports, and validated sampling data results comprise Appendix D

  20. Premature closure of the Trojan Nuclear Plant

    International Nuclear Information System (INIS)

    Kononetz, B.P.

    1995-01-01

    The premature closure of the Trojan Nuclear Plant is discussed in outline form. The topics discussed include: an overview of Trojan; events leading to shutdown decision; Trojan's lifetime O ampersand M performance; Trojan's Regulatory performance; historical Trojan regulatory versus economic performance; applicable Oregon law; least-cost planning process; 1992 least cost plan; 1993 LCP update; LCP limitations; comparative performance analysis; management assessments; Trojan O ampersand M analysis; steam generator issues; quantification of deficiencies; quantification of impact of steam generator degradation; 'net benefits' test; conclusions from net benefits analysis; total disallowances; and conclusions and ramifications

  1. Multiple coil closure of isolated aortopulmonary collateral

    Directory of Open Access Journals (Sweden)

    Padhi Sumanta

    2010-01-01

    Full Text Available A 7-month-old girl was diagnosed to have large aortopulmonary collateral during evaluation for congestive heart failure. There was no other evidence of cardiopulmonary disease. The collateral was successfully closed with multiple coils delivered sequentially. We describe the issues associated during closure of the aortopulmonary collateral in this case. To the best of our knowledge, this is the first reported case of large aortopulmonary collateral presenting with heart failure in an otherwise structurally normal heart that was closed successfully with multiple coils delivered sequentially.

  2. Post Closure Safety of the Morsleben Repository

    International Nuclear Information System (INIS)

    Preuss, J.; Eilers, G.; Mauke, R.; Moeller-Hoeppe, N.; Engelhardt, H.-J.; Kreienmeyer, M.; Lerch, C.; Schrimpf, C.

    2002-01-01

    After the completion of detailed studies of the suitability the twin-mine Bartensleben-Marie, situated in the Federal State of Saxony-Anhalt (Germany), was chosen in 1970 for the disposal of low and medium level radioactive waste. The waste emplacement started in 1978 in rock cavities at the mine's fourth level, some 500 m below the surface. Until the end of the operational phase in 1998 in total about 36,800 m 3 of radioactive waste was disposed of. The Morsleben LLW/ILW repository (ERAM) is now under licensing for closure. After completing the licensing procedure the repository will be sealed and backfilled to exclude any undue future impact onto man or the environment. The main safety objective is to protect the biosphere from the harmful effects of the disposed radionuclides. Furthermore, classical or conventional requirements call for ruling out or minimizing other unfavorable environmental effects. The ERAM is an abandoned rock salt and potash mine. As a consequence it has a big void volume, however small parts of the cavities are backfilled with crushed salt rocks. Other goals of the closure concept are therefore a long-term stabilization of the cavities to prevent a dipping or buckling of the ground surface. In addition, groundwater protection shall be assured. For the sealing of the repository a closure concept was developed to ensure compliance with the safety protection objectives. The concept anticipates the backfilling of the cavities with hydraulically setting backfill materials (salt concretes). The reduction of the remaining void volume in the mine causes in the case of brine intrusions a limitation of the leaching processes of the exposed potash seams. However, during the setting process the hydration heat of the concrete will lead to an increase of the temperature and hence to thermally induced stresses of the concrete and the surrounding rocks. Therefore, the influence of these stresses and deformations on the stability of the salt body and the

  3. Transcatheter closure of patent ductus arteriosus: past, present and future.

    Science.gov (United States)

    Baruteau, Alban-Elouen; Hascoët, Sébastien; Baruteau, Julien; Boudjemline, Younes; Lambert, Virginie; Angel, Claude-Yves; Belli, Emre; Petit, Jérôme; Pass, Robert

    2014-02-01

    This review aims to describe the past history, present techniques and future directions in transcatheter treatment of patent ductus arteriosus (PDA). Transcatheter PDA closure is the standard of care in most cases and PDA closure is indicated in any patient with signs of left ventricular volume overload due to a ductus. In cases of left-to-right PDA with severe pulmonary arterial hypertension, closure may be performed under specific conditions. The management of clinically silent or very tiny PDAs remains highly controversial. Techniques have evolved and the transcatheter approach to PDA closure is now feasible and safe with current devices. Coils and the Amplatzer Duct Occluder are used most frequently for PDA closure worldwide, with a high occlusion rate and few complications. Transcatheter PDA closure in preterm or low-bodyweight infants remains a highly challenging procedure and further device and catheter design development is indicated before transcatheter closure is the treatment of choice in this delicate patient population. The evolution of transcatheter PDA closure from just 40 years ago with 18F sheaths to device delivery via a 3F sheath is remarkable and it is anticipated that further improvements will result in better safety and efficacy of transcatheter PDA closure techniques. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  4. Mixed Waste Management Facility closure at the Savannah River Site

    International Nuclear Information System (INIS)

    Bittner, M.F.

    1991-08-01

    The Mixed Waste Management Facility of the Savannah River Plant received hazardous and solid low level radioactive wastes from 1972 until 1986. Because this facility did not have a permit to receive hazardous wastes, a Resource Conservation and Recovery Act closure was performed between 1987 and 1990. This closure consisted of dynamic compaction of the waste trenches and placement of a 3-foot clay cap, a 2-foot soil cover, and a vegetative layer. Operations of the waste disposal facility, tests performed to complete the closure design, and the construction of the closure cap are discussed herein

  5. U.S. Small Business HUBZone Base Closure Areas

    Data.gov (United States)

    Small Business Administration — HUBZone Qualitified Base Closure Areas - the lands within the boundaries of a military installation that was closed through a privatization process under the Federal...

  6. Digital signal processing of data from borehole creep closure

    International Nuclear Information System (INIS)

    Chakrabarti, S.; Patrick, W.C.; Duplancic, N.

    1987-01-01

    Digital signal processing, a technique commonly used in the fields of electrical engineering and communication technology, has been successfully used to analyze creep closure data obtained from a 0.91 m diameter by 5.13 deep borehole in bedded salt. By filtering the ''noise'' component of the closure data from a test borehole, important data trends were made more evident and average creep closure rates were able to be calculated. This process provided accurate estimates of closure rates that are used in the design of lined boreholes in which heat-generating transuranic nuclear wastes are emplaced at the Waste Isolation Pilot Plant

  7. Troughs on Martian Ice Sheets: Analysis of Their Closure and Mass Balance

    Science.gov (United States)

    Fountain, A.; Kargel, J.; Lewis, K.; MacAyeal, D.; Pfeffer, T.; Zwally, J.

    2000-01-01

    At the Copenhagen workshop on Martian polar processes, Ralf Greve commented that the flow regime surrounding scarps and troughs of the Martian polar ice sheets cannot be modeled using traditional "plan view" ice-sheet models. Such models are inadequate because they typically use reduced equations that embody certain simplifications applicable only to terrestrial ice sheets where the upper ice sheet surface is smooth. In response to this suggestion, we have constructed a 2-dimensional, time dependent "side view" (two spatial dimensions: one horizontal, one vertical) model of scarp closure that is designed to overcome the difficulties described by Greve. The purpose of the model is to evaluate the scales of stress variation and styles of flow closure so as to estimate errors that may be encountered by "plan view" models. We show that there may be avenues whereby the complications associated with scarp closure can be overcome in "plan view" models through appropriate parameterizations of 3-dimensional effects. Following this, we apply the flow model to simulate the evolution of a typical scarp on the North Polar Cap of Mars. Our simulations investigate: (a) the role of "radiation trapping" (see our companion abstract) in creating and maintaining "spiral-like" scarps on the ice sheet, (b) the consequences of different flowlaws and ice compositions on scarp evolution and, in particular, scarp age, and (c) the role of dust and debris in scarp evolution.

  8. Waste disposal facility closure concept and post-closure institutional control considerations in Germany

    International Nuclear Information System (INIS)

    Berg, H.P.

    1994-01-01

    Considerations of a waste repository concept in the Federal Republic of Germany are explained on the basis of the planned Konrad repository, a final disposal facility in a deep geological formation. The necessity of institutional control and surveillance in the post-closure phase as well as the marking of a waste repository in deep geological formations are discussed. (author) 3 figs., 6 refs

  9. Interim status of closure/post-closure plan for 183-H solar evaporation basins

    International Nuclear Information System (INIS)

    1988-03-01

    This report describes a plan for decommissioning several solar evaporation basins on the Hanford reservation. The document describes procedures for sampling during decommissioning and a plan for certification of the resulting completed landfill. Additional plans deal with the training, security of the site, and post-closure monitoring

  10. Cost-effectiveness of percutaneous patent foramen ovale closure as secondary stroke prevention.

    Science.gov (United States)

    Tirschwell, David L; Turner, Mark; Thaler, David; Choulerton, James; Marks, David; Carroll, John; MacDonald, Lee; Smalling, Richard W; Koullick, Maria; Gu, Ning Yan; Saver, Jeffrey L

    2018-04-13

    Compared to medical therapy alone, percutaneous closure of patent foramen ovale (PFO) further reduces risk of recurrent ischemic strokes in carefully selected young to middle-aged patients with a recent cryptogenic ischemic stroke. The objective of this study was to evaluate the cost-effectiveness of this therapy in the context of the United Kingdom (UK) healthcare system. A Markov cohort model consisting of four health states (Stable after index stroke, Post-Minor Recurrent Stroke, Post-Moderate Recurrent Stroke, and Death) was developed to simulate the economic outcomes of device-based PFO closure compared to medical therapy. Recurrent stroke event rates were extracted from a randomized clinical trial (RESPECT) with a median of 5.9-year follow-up. Health utilities and costs were obtained from published sources. One-way and probabilistic sensitivity analyses (PSA) were performed to assess robustness. The model was discounted at 3.5% and reported in 2016 Pounds Sterling. Compared with medical therapy alone and using a willingness-to-pay (WTP) threshold of £20,000, PFO closure reached cost-effectiveness at 4.2 years. Cost-effectiveness ratios (ICERs) at 4, 10, and 20 years were ₤20,951, ₤6,887, and ₤2,158, respectively. PFO closure was cost-effective for 89% of PSA iterations at year 10. Sensitivity analyses showed that the model was robust. Considering the UK healthcare system perspective, percutaneous PFO closure in cryptogenic ischemic stroke patients is a cost-effective stroke prevention strategy compared to medical therapy alone. Its cost-effectiveness was driven by substantial reduction in recurrent strokes and patients' improved health-related quality-of-life.

  11. Acculturation attitudes, need for cognitive closure, and adaptation of immigrants.

    Science.gov (United States)

    Kosic, Ankica

    2002-04-01

    The author validated Berry's model of acculturation (J. W. Berry, 1990a, 1990b, 1991; J. W. Berry, U. Kim, S. Power, M. Young, & M. Bujaki, 1989) and examined the relation between acculturation attitudes and sociocultural and psychological adaptation among Croatian and Polish immigrants to Italy, 2 groups whose cultures are not very different from the Italian culture. Moreover, the author investigated the relation between the need for cognitive closure (NCC; M. D. Webster & A. W. Kruglanski, 1994) and psychological and sociocultural adaptation. The participants completed a questionnaire including measures of sociocultural adaptation, psychological adaptation, social relationships, acculturation attitudes, and NCC. The results of a multivariate analysis of variance revealed main effects of acculturation strategies for both forms of adaptation and a main effect of NCC for psychological adaptation. The Croatian and Polish immigrants differed in the level of sociocultural adaptation but not in the level of psychological adaptation.

  12. Round window closure affects cochlear responses to suprathreshold stimuli.

    Science.gov (United States)

    Cai, Qunfeng; Whitcomb, Carolyn; Eggleston, Jessica; Sun, Wei; Salvi, Richard; Hu, Bo Hua

    2013-12-01

    The round window acts as a vent for releasing inner ear pressure and facilitating basilar membrane vibration. Loss of this venting function affects cochlear function, which leads to hearing impairment. In an effort to identify functional changes that might be used in clinical diagnosis of round window atresia, the current investigation was designed to examine how the cochlea responds to suprathreshold stimuli following round window closure. Prospective, controlled, animal study. A rat model of round window occlusion (RWO) was established. With this model, the thresholds of auditory brainstem responses (ABR) and the input/output (IO) functions of distortion product otoacoustic emissions (DPOAEs) and acoustic startle responses were examined. Round window closure caused a mild shift in the thresholds of the auditory brainstem response (13.5 ± 9.1 dB). It also reduced the amplitudes of the distortion product otoacoustic emissions and the slope of the input/output functions. This peripheral change was accompanied by a significant reduction in the amplitude, but not the threshold, of the acoustic startle reflex, a motor response to suprathreshold sounds. In addition to causing mild increase in the threshold of the auditory brainstem response, round window occlusion reduced the slopes of both distortion product otoacoustic emissions and startle reflex input/output functions. These changes differ from those observed for typical conductive or sensory hearing loss, and could be present in patients with round window atresia. However, future clinical observations in patients are needed to confirm these findings. Copyright © 2013 The American Laryngological, Rhinological and Otological Society, Inc.

  13. On Averaging Timescales for the Surface Energy Budget Closure Problem

    Science.gov (United States)

    Grachev, A. A.; Fairall, C. W.; Persson, O. P. G.; Uttal, T.; Blomquist, B.; McCaffrey, K.

    2017-12-01

    An accurate determination of the surface energy budget (SEB) and all SEB components at the air-surface interface is of obvious relevance for the numerical modelling of the coupled atmosphere-land/ocean/snow system over different spatial and temporal scales, including climate modelling, weather forecasting, environmental impact studies, and many other applications. This study analyzes and discusses comprehensive measurements of the SEB and the surface energy fluxes (turbulent, radiative, and ground heat) made over different underlying surfaces based on the data collected during several field campaigns. Hourly-averaged, multiyear data sets collected at two terrestrial long-term research observatories located near the coast of the Arctic Ocean at Eureka (Canadian Archipelago) and Tiksi (East Siberia) and half-hourly averaged fluxes collected during a year-long field campaign (Wind Forecast Improvement Project 2, WFIP 2) at the Columbia River Gorge (Oregon) in areas of complex terrain. Our direct measurements of energy balance show that the sum of the turbulent sensible and latent heat fluxes systematically underestimate the available energy at half-hourly and hourly time scales by around 20-30% at these sites. This imbalance of the surface energy budget is comparable to other terrestrial sites. Surface energy balance closure is a formulation of the conservation of energy principle (the first law of thermodynamics). The lack of energy balance closure at hourly time scales is a fundamental and pervasive problem in micrometeorology and may be caused by inaccurate estimates of the energy storage terms in soils, air and biomass in the layer below the measurement height and above the heat flux plates. However, the residual energy imbalance is significantly reduced at daily and monthly timescales. Increasing the averaging time to daily scales substantially reduces the storage terms because energy locally entering the soil, air column, and vegetation in the morning is

  14. Reinvestigation into Closure Predictions of Room D at the Waste Isolation Pilot Plant

    Energy Technology Data Exchange (ETDEWEB)

    Reedlunn, Benjamin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-10-01

    Room D was an in-situ, isothermal, underground experiment conducted at theWaste Isolation Pilot Plant between 1984 and 1991. The room was carefully instrumented to measure the horizontal and vertical closure immediately upon excavation and for several years thereafter. Early finite element simulations of salt creep around Room D under predicted the vertical closure by 4.5×, causing investigators to explore a series of changes to the way Room D was modeled. Discrepancies between simulations and measurements were resolved through a series of adjustments to model parameters, which were openly acknowledged in published reports. Interest in Room D has been rekindled recently by the U.S./German Joint Project III and Project WEIMOS, which seek to improve the predictions of rock salt constitutive models. Joint Project participants calibrate their models solely against laboratory tests, and benchmark the models against underground experiments, such as room D. This report describes updating legacy Room D simulations to today’s computational standards by rectifying several numerical issues. Subsequently, the constitutive model used in previous modeling is recalibrated two different ways against a suite of new laboratory creep experiments on salt extracted from the repository horizon of the Waste Isolation Pilot Plant. Simulations with the new, laboratory-based, calibrations under predict Room D vertical closure by 3.1×. A list of potential improvements is discussed.

  15. Reinvestigation into Closure Predictions of Room D at the Waste Isolation Pilot Plant

    Energy Technology Data Exchange (ETDEWEB)

    Reedlunn, Benjamin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-09-27

    Room D was an in-situ, isothermal, underground experiment conducted at the Waste Isolation Pilot Plant between 1984 and 1991. The room was carefully instrumented to measure the horizontal and vertical closure immediately upon excavation and for several years thereafter. Early finite element simulations of salt creep around Room D under-predicted the vertical closure by 4.5×, causing investigators to explore a series of changes to the way Room D was modeled. Discrepancies between simulations and measurements were resolved through a series of adjustments to model parameters, which were openly acknowledged in published reports. Interest in Room D has been rekindled recently by the U.S./German Joint Project III and Project WEIMOS, which seek to improve the predictions of rock salt constitutive models. Joint Project participants calibrate their models solely against laboratory tests, and benchmark the models against underground experiments, such as room D. This report describes updating legacy Room D simulations to today’s computational standards by rectifying several numerical issues. Subsequently, the constitutive model used in previous modeling is recalibrated two different ways against a suite of new laboratory creep experiments on salt extracted from the repository horizon of the Waste Isolation Pilot Plant. Simulations with the new, laboratory-based, calibrations under-predict Room D vertical closure by 3.1×. A list of potential improvements is discussed.

  16. IT SERVICES AVAILABILITY DURING CERN ANNUAL CLOSURE

    CERN Multimedia

    2002-01-01

    Mail, NICE 2000, Web, EDMS (in collaboration with EST Division), General purpose databases, lxbatch, lxplus, Automated tape devices, Castor, Backups, Campus Network, Remedy, Security and VPN services will be available during the CERN annual closure. Problems developing on these services should be addressed within about half a day except on Christmas and New Year evenings, December 25, 2002 and January 1st, 2003. All other services will be left running mostly unattended. No interruptions are scheduled but restoration of the service in case of failure cannot be guaranteed. It should be noted that the Helpdesk will be closed, that no file restores from backups will be possible and damaged tapes will not be processed. An operator service will be maintained and can be reached at extension 75011 or by email to computer.operations@cern.ch. Please remember to shutdown and power off any equipment in your office which is not foreseen to be used during the annual closure before you leave for the holiday.

  17. Vascular Closure Devices in Interventional Radiology Practice

    International Nuclear Information System (INIS)

    Patel, Rafiuddin; Muller-Hulsbeck, Stefan; Morgan, Robert; Uberoi, Raman

    2015-01-01

    Manual compression (MC) is a well-established technique for haemostasis following percutaneous arterial intervention. However, MC is labour and time intensive with potential limitations, particularly for patients who are coagulopathic, unable to comply with bed rest or obese and when large sheaths or anti-coagulants are used. There are a variety of vascular closure devices (VCDs) available to overcome these limitations. This review gives an overview of current VCDs, their mechanism of action, individual strengths and weaknesses, evidence base and utility in interventional radiology (IR) practice. The majority of the published evidence on VCDs is derived from patients undergoing cardiac interventions, which should be borne in mind when considering the applicability and transfer of this data for general IR practice. Overall, the evidence suggests that most VCDs are effective in achieving haemostasis with a similar rate of complications to MC although the complication profile associated with VCDs is distinct to that of MC. There is insufficient evidence to comparatively analyse the different types of VCDs currently available or reliably judge their cost-effectiveness. The interventional radiologist should have a thorough understanding of the available techniques for haemostasis and be able to identify and utilise the most appropriate strategy and closure technique for the individual patient

  18. Accelerating cleanup. Paths to closure Hanford Site

    International Nuclear Information System (INIS)

    Edwards, C.

    1998-01-01

    This document was previously referred to as the Draft 2006 Plan. As part of the DOE's national strategy, the Richland Operations Office's Paths to Closure summarizes an integrated path forward for environmental cleanup at the Hanford Site. The Hanford Site underwent a concerted effort between 1994 and 1996 to accelerate the cleanup of the Site. These efforts are reflected in the current Site Baseline. This document describes the current Site Baseline and suggests strategies for further improvements in scope, schedule and cost. The Environmental Management program decided to change the name of the draft strategy and the document describing it in response to a series of stakeholder concerns, including the practicality of achieving widespread cleanup by 2006. Also, EM was concerned that calling the document a plan could be misconstrued to be a proposal by DOE or a decision-making document. The change in name, however, does not diminish the 2006 vision. To that end, Paths to Closure retains a focus on 2006, which serves as a point in time around which objectives and goals are established

  19. Mixing in SRS Closure Business Unit Applications

    International Nuclear Information System (INIS)

    POIRIER, MICHAELR.

    2004-01-01

    The following equipment is commonly used to mix fluids: mechanical agitators, jets (pumps), shrouded axial impeller mixers (Flygt mixers), spargers, pulsed jet mixers, boiling, static mixers, falling films, liquid sprays, and thermal convection. This discussion will focus on mechanical agitators, jets, shrouded axial impeller mixers, spargers, and pulsed jet mixers, as these devices are most likely to be employed in Savannah River Site (SRS) Closure Business applications. In addressing mixing problems in the SRS Tank Farm, one must distinguish between different mixing objectives. These objectives include sludge mixing (e.g., Extended Sludge Processing), sludge retrieval (e.g., sludge transfers between tanks), heel retrieval (e.g., Tanks 18F and 19F), chemical reactions (e.g., oxalic acid neutralization) and salt dissolution. For example, one should not apply sludge mixing guidelines to heel removal applications. Mixing effectiveness is a function of both the mixing device (e.g., slurry pump, agitator, air sparger) and the properties of the material to be mixed (e.g., yield stress, viscosity, density, and particle size). The objective of this document is to provide background mixing knowledge for the SRS Closure Business Unit personnel and to provide general recommendations for mixing in SRS applications

  20. Closure plan for the proposed Millennium Project

    International Nuclear Information System (INIS)

    Tuttle, S.; Sisson, R.

    1999-01-01

    A $2.2 billion expansion of the current oil sands operation has been proposed by Suncor Energy Inc. The expansion would more than double the productive capacity of the present facility. As part of the application for this expansion, called Project Millennium, a comprehensive closure plan has been developed and filed by the Corporation. The Plan includes a systematic evaluation of the area to be developed, a description of the development activities planned, and the goals and objectives of the Corporation in re-establishing the landforms and ecosystems concurrently with running the operation. The Plan envisages surface contouring as early as practicable during the mine development, soil reconstruction, and re-establishment of vegetation, surface drainage and wetlands. The Corporation undertakes to monitor the performance of the reclaimed areas based on landform performance, the impact of chemical constituents on the landscape and ecosystem sustainability. An annual monitoring report assessing herbaceous vegetation growth, major species composition, tree and shrub survival and growth rate, groundwater conditions, amount of precipitation, the utility of constructed wetlands for treatment of reclamation area seepage and runoff waters, and wildlife population changes, will be prepared annually. A future research program associated with the Reclamation and Closure Plan will also examine the effectiveness of the reclamation drainage system as fish habitat, and the potential of the proposed end-pit lake to provide a viable aquatic ecosystem. 8 refs., 2 figs

  1. Container Closure Integrity Testing of Prefilled Syringes.

    Science.gov (United States)

    Peláez, Sarah S; Mahler, Hanns-Christian; Matter, Anja; Koulov, Atanas; Singh, Satish K; Germershaus, Oliver; Mathaes, Roman

    2018-04-04

    Prefilled syringes (PFSs) are increasingly preferred over vials as container closure systems (CCSs) for injectable drug products when facilitated or self-administration is required. However, PFSs are more complex compared to CCSs consisting of vial, rubber stopper and crimp cap. Container closure integrity (CCI) assurance and verification has been a specific challenge for PFSs as they feature several sealing areas. A comprehensive understanding of the CCS is necessary for an appropriate CCI assessment as well as for packaging development and qualification. A comprehensive CCI assessment of six different PFSs from three different manufacturers (including one polymeric PFS) was conducted using helium leak testing. PFS components were manipulated to systematically assess the contribution of the different sealing areas to CCI, namely rigid needle shield (RNS)/needle, RNS/tip cone and the individual ribs of a syringe plunger. The polymeric PFS required an equilibrium measurement for accurate CCIT. The different sealing areas and a single plunger rib were shown to provide adequate CCI. Acceptable tip cap movement until the point of CCI failure was estimated. The assessment of acceptable tip cap movement demonstrated the importance of considering the RNS/tip cone seal design to ensure CCI of the PFS upon post assembly possesses and shipment. Copyright © 2018. Published by Elsevier Inc.

  2. Ocular Biometry in Primary Angle-Closure Glaucoma Associated with Retinitis Pigmentosa

    Directory of Open Access Journals (Sweden)

    Jiangang Xu

    2017-01-01

    Full Text Available Background. Retinitis pigmentosa (RP comprises a group of inherited disorders in which patients typically lose night vision in adolescence and then lose peripheral vision in young adulthood before eventually losing central vision later in life. A retrospective case-control study was performed to evaluate differences in ocular biometric parameters in primary angle-closure glaucoma (PACG patients with and without concomitant RP to determine whether a relationship exists between PACG and RP. Methods. We used ultrasound biomicroscopy (UBM to measure anterior chamber depth (ACD. A-scan biometry was carried out to measure lens thickness (LT and axial length (AL. Propensity score matching and mixed linear regression model analysis were conducted. 23 patients with chronic primary angle-closure glaucoma (CPACG associated with RP, 21 patients with acute primary angle-closure glaucoma (APACG associated with RP, 270 patients with CPACG, and 269 patients with APACG were recruited for this study. Results. There were no significant differences on ACDs, ALs, and relative lens position (RLP (P>0.05 between patients with PACG associated with RP and patients with PACG; however, patients with APACG associated with RP had a significantly greater LT than patients with APACG (P<0.05. Conclusion. Patients with PACG associated with RP had the same biometric parameter characteristic as the patients with CPACG and APACG. This may suggest that RP is a coincidental relationship with angle-closure glaucoma.

  3. Wind-Ramp-Forecast Sensitivity to Closure Parameters in a Boundary-Layer Parametrization Scheme

    Science.gov (United States)

    Jahn, David E.; Takle, Eugene S.; Gallus, William A.

    2017-09-01

    Wind ramps are relatively large changes in wind speed over a period of a few hours and present a challenge for electric utilities to balance power generation and load. Failures of boundary-layer parametrization schemes to represent physical processes limit the ability of numerical models to forecast wind ramps, especially in a stable boundary layer. Herein, the eight "closure parameters" of a widely used boundary-layer parameterization scheme are subject to sensitivity tests for a set of wind-ramp cases. A marked sensitivity of forecast wind speed to closure-parameter values is observed primarily for three parameters that influence in the closure equations the depth of turbulent mixing, dissipation, and the transfer of kinetic energy from the mean to the turbulent flow. Reducing the value of these parameters independently by 25% or by 50% reduces the overall average in forecast wind-speed errors by at least 24% for the first two parameters and increases average forecast error by at least 63% for the third parameter. Doubling any of these three parameters increases average forecast error by at least 67%. Such forecast sensitivity to closure parameter values provides motivation to explore alternative values in the context of a stable boundary layer.

  4. Matching-range-constrained real-time loop closure detection with CNNs features.

    Science.gov (United States)

    Bai, Dongdong; Wang, Chaoqun; Zhang, Bo; Yi, Xiaodong; Tang, Yuhua

    2016-01-01

    The loop closure detection (LCD) is an essential part of visual simultaneous localization and mapping systems (SLAM). LCD is capable of identifying and compensating the accumulation drift of localization algorithms to produce an consistent map if the loops are checked correctly. Deep convolutional neural networks (CNNs) have outperformed state-of-the-art solutions that use traditional hand-crafted features in many computer vision and pattern recognition applications. After the great success of CNNs, there has been much interest in applying CNNs features to robotic fields such as visual LCD. Some researchers focus on using a pre-trained CNNs model as a method of generating an image representation appropriate for visual loop closure detection in SLAM. However, there are many fundamental differences and challenges involved in character between simple computer vision applications and robotic applications. Firstly, the adjacent images in the dataset of loop closure detection might have more resemblance than the images that form the loop closure. Secondly, real-time performance is one of the most critical demands for robots. In this paper, we focus on making use of the feature generated by CNNs layers to implement LCD in real environment. In order to address the above challenges, we explicitly provide a value to limit the matching range of images to solve the first problem; meanwhile we get better results than state-of-the-art methods and improve the real-time performance using an efficient feature compression method.

  5. Risk-based approach to appraise valve closure in the clam Corbicula fluminea in response to waterborne metals

    Energy Technology Data Exchange (ETDEWEB)

    Liao, C.-M. [Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, Taiwan 10617 (China)]. E-mail: cmliao@ntu.edu.tw; Jou, L.-J. [Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, Taiwan 10617 (China); Department of Biomechatronic Engineering, National Ilan University, Ilan, Taiwan 260 (China); Chen, B.-C. [Department of Post-Modern Agriculture, Mingdao University, Changhua, Taiwan 52345 (China)

    2005-05-01

    We developed a risk-based approach to assess how the valve closure behavior of Asiatic clam Corbicula fluminea responds to waterborne copper (Cu) and cadmium (Cd). We reanalyzed the valve closure response data from published literature to reconstruct the response time-dependent dose-response profiles based on an empirical three-parameter Hill equation model. We integrated probabilistic exposure profiles of measured environmental Cu and Cd concentrations in the western coastal areas of Taiwan with the reconstructed dose-response relationships at different integration times of response to quantitatively estimate the valve response risk. The risk assessment results implicate exposure to waterborne Cu and Cd may pose no significant risk to clam valve activity in the short-time response periods (e.g., <30 min), yet a relative high risk for valve closure response to waterborne Cu at response times greater than 120 min is alarming. We successfully linked reconstructed dose-response profiles and EC50-time relationships associated with the fitted daily valve opening/closing rhythm characterized by a three-parameter lognormal function to predict the time-varying bivalve closure rhythm response to waterborne metals. We parameterized the proposed predictive model that should encourage a risk-management framework for discussion of future design of biological monitoring systems. - A model was developed to link valve closure in clams to concentrations of metals in water.

  6. Vacuum-Assisted Abdominal Closure Is Safe and Effective

    DEFF Research Database (Denmark)

    Jensen, R O; Buchbjerg, T; Simonsen, R M

    2017-01-01

    with median 1 (0-16) dressing changes. Seventy per cent of the patients attended the intensive care unit. The 90-day mortality was 15%. A secondary closure of the fascia was obtained in 84% of the surviving patients. Only one patient developed an enteroatmospheric fistula. Patients with secondary closure were...

  7. 77 FR 55895 - Permanent Closure of Cincinnati Blue Ash Airport

    Science.gov (United States)

    2012-09-11

    ... Federal Aviation Administration Permanent Closure of Cincinnati Blue Ash Airport AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of permanent closure of Cincinnati Blue Ash Airport (ISZ). SUMMARY: The... Cincinnati advising that on August 29, 2012, it was permanently closing Cincinnati Blue Ash Airport (ISZ...

  8. The Impact of Mine Closures on Rural Population Dynamics: The ...

    African Journals Online (AJOL)

    The paper examines the demographic and socio-cultural impact of spontaneous population inflows into Zhombe following the closure of the Empress Mine in 1982. Data was collected using a questionnaire survey. Results of the study show that mine closures cause rural population change. The population directly grows ...

  9. Clinical trial comparing excision and primary closure with modified ...

    African Journals Online (AJOL)

    Walid Galal Elshazly

    2011-12-03

    Dec 3, 2011 ... hairy skin.1 It is more common in people aged 15–30 years after puberty due to the ... delayed wound healing, discomfort and high rate of recurrence which range ... tissue healing.4,5. Excision and primary closure involve excision of the entire sinus with closure of the wound. This procedure has the advan-.

  10. Decontamination Study for Mixed Waste Storage Tanks RCRA Closure

    International Nuclear Information System (INIS)

    Leaphart, D.M.; Reed, S.R.; Rankin, W.N.

    1995-01-01

    The Savannah River Site (SRS) plans to close six underground tanks storing mixed waste under RCRA regulations. In support of this closure effort, a study was performed to determine the optimal method of decontaminating these tanks to meet the closure requirements. Items consaidered in the evaluation of the decontamination methods included effectiveness, compatibility with existing waste residues, possible cleaning solution disposal methods, and cost

  11. T-tube vs Primary Common Bile Duct Closure

    Directory of Open Access Journals (Sweden)

    M R Joshi

    2010-09-01

    Full Text Available INTRODUCTION: Closure of the common bile duct over T-tube after exploration is a widely practiced traditional method. However, its use may give rise to many complications. We do primary closure of common bile duct after exploration. Aim of the study is to see the efficacy and safety of the primary closure. METHODS: Study was carried out to compare the results of both the techniques from 2006 to 2009 in the cases proven to have common bile duct stone with or without the features of obstructive jaundice. Post operative hospital stay and morbidities related to both the groups were recorded and analyzed. RESULTS: There were total 71 cases included in the study. Thirty one in T-tube group and 40 in primary closure group. T-tube was removed in most of the cases after three weeks where as average time of drain removal in primary closure group is 5.79 +/-1.79 days. Incidence of retained stone was equal in each group. Major complication in T-tube group is biliary peritonitis in four patients at the time of T-tube removal whereas none of the patient from primary closure group suffered from such major complication. CONCLUSIONS: Primary closure after the common bile duct exploration is safe and it helps to avoid the morbidities related to T-tube. Keywords: Choledocholithiasis, Primary closure, retained stone, T-tube, Ureterorenoscope.

  12. Neutron and proton shell closure in the superheavy region via ...

    Indian Academy of Sciences (India)

    ... = 162, 172 and 184. Isotopic and isobaric mass parabolas are studied for various cluster emissions and minima of parabola indicate neutron shell closure at = 162, 184 and proton shell closure at = 114. Our study shows that 162 276 114 is the deformed doubly magic and 184 298 114 is the spherical doubly magic ...

  13. Cracked Vases and Untidy Seams: Narrative Structure and Closure ...

    African Journals Online (AJOL)

    The TRC reveals a tension between a desire to open up the story of the past and to “close the chapter on our past”. I explore this tension by considering both the TRC's relation to closure and those of selected fictional narratives that explicitly respond to the TRC. I argue that the tidy closure of reconciliation both excludes the ...

  14. 50 CFR 600.511 - Fishery closure procedures.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Fishery closure procedures. 600.511 Section 600.511 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND... Fishery closure procedures. (a) Activity Codes 1 and 2 for a fishery are automatically canceled in the...

  15. WASTE PACKAGE OPERATIONS FY-99 CLOSURE METHODS REPORT

    International Nuclear Information System (INIS)

    M. C. Knapp

    1999-01-01

    The waste package (WP) closure weld development task is part of a larger engineering development program to develop waste package designs. The purpose of the larger waste package engineering development program is to develop nuclear waste package fabrication and closure methods that the Nuclear Regulatory Commission will find acceptable and will license for disposal of spent nuclear fuel (SNF), non-fuel components, and vitrified high-level waste within a Monitored Geologic Repository (MGR). Within the WP closure development program are several major development tasks, which, in turn, are divided into subtasks. The major tasks include: WP fabrication development, WP closure weld development, nondestructive examination (NDE) development, and remote in-service inspection development. The purpose of this report is to present the objectives, technical information, and work scope relating to the WP closure weld development.and NDE tasks and subtasks and to report results of the closure weld and NDE development programs for fiscal year 1999 (FY-99). The objective of the FY-99 WP closure weld development task was to develop requirements for closure weld surface and volumetric NDE performance demonstrations, investigate alternative NDE inspection techniques, and develop specifications for welding, NDE, and handling system integration. In addition, objectives included fabricating several flat plate mock-ups that could be used for NDE development, stress relief peening, corrosion testing, and residual stress testing

  16. Biomechanics Strategies for Space Closure in Deep Overbite

    Directory of Open Access Journals (Sweden)

    Harryanto Wijaya

    2013-07-01

    Full Text Available Space closure is an interesting aspect of orthodontic treatment related to principles of biomechanics. It should be tailored individually based on patient’s diagnosis and treatment plan. Understanding the space closure biomechanics basis leads to achieve the desired treatment objective. Overbite deepening and losing posterior anchorage are the two most common unwanted side effects in space closure. Conventionally, correction of overbite must be done before space closure resulted in longer treatment. Application of proper space closure biomechanics strategies is necessary to achieve the desired treatment outcome. This cases report aimed to show the space closure biomechanics strategies that effectively control the overbite as well as posterior anchorage in deep overbite patients without increasing treatment time. Two patients who presented with class II division 1 malocclusion were treated with fixed orthodontic appliance. The primary strategies included extraction space closure on segmented arch that employed two-step space closure, namely single canine retraction simultaneously with incisors intrusion followed by enmasse retraction of four incisors by using differential moment concept. These strategies successfully closed the space, corrected deep overbite and controlled posterior anchorage simultaneously so that the treatment time was shortened. Biomechanics strategies that utilized were effective to achieve the desired treatment outcome.

  17. Strengthening the closure concept in claw-free graphs

    NARCIS (Netherlands)

    Broersma, Haitze J.; Ryjacek, Zdenek

    2001-01-01

    We give a strengthening of the closure concept for claw-free graphs introduced by the second author in 1997. The new closure of a claw-free graph G defined here is uniquely determined and preserves the value of the circumference of G. We present an infinite family of graphs with n vertices and

  18. Strengthening the closure concept in claw-free graphs

    NARCIS (Netherlands)

    Broersma, Haitze J.; Ryjacek, Z.

    2000-01-01

    We give a strengthening of the closure concept for claw-free graphs introduced by the second author in 1997. The new closure of a claw-free graph $G$ defined here is uniquely determined and preserves the value of the circumference of $G$. We present an infinite family of graphs with $n$ vertices and

  19. Surgical Experience with Closure of an Isolated PDA at Muhimbili ...

    African Journals Online (AJOL)

    Results: A total of 52 patients with clinical diagnosis of PDA, 26 patients in each treatment group of either standard closure or new closure technique. ... string on the ampulla of the PDA followed by a silk ligature has proved to be efficient and reliable technique that leaves no residual lesion with no long term complications.

  20. Which Patent Foramen Ovales Need Closure to Prevent Cryptogenic Strokes?

    Science.gov (United States)

    Dalen, James E; Alpert, Joseph S

    2018-03-01

    Patients with cryptogenic strokes are more likely to have a patent foremen ovale than in the general population. It is speculated that these strokes are due to paradoxical embolism, that is, passage of a venous thrombus across the patent foremen ovale to enter the arterial circulation, resulting in an embolic stroke. Venous thromboembolism is rarely present in these cases of cryptogenic stroke. Thousands of patients with cryptogenic strokes have undergone transcatheter closure of their patent foremen ovale via a variety of devices. The first 3 randomized clinical trials comparing patent foremen ovale closure with medical therapy failed to show a significant advantage of patent foremen ovale closure. Three additional trials reported in 2017 had longer years of follow-up and demonstrated an advantage of patent foremen ovale closure versus medical therapy. Analysis of their data indicated that patent foremen ovale closure in patients with an atrial septal aneurysm in addition to a patent foremen ovale had a very significant decrease in cryptogenic strokes (P patent foremen ovale closure (P = .37). Aneurysms of the atrial septum are easily recognized by echocardiography and are present in approximately one-third of patients with patent foremen ovales. These data suggest that closure of patent foremen ovales in patients with an atrial septal aneurysm is indicated. In patients with a patent foremen ovale without an aneurysm of the atrial septum, patent foremen ovale closure is not indicated. Copyright © 2018 Elsevier Inc. All rights reserved.

  1. On the normality of orbit closures which are hypersurfaces

    Indian Academy of Sciences (India)

    Let be a quiver representation with non-zero admissible annihilator. In this paper, we prove the normality of the orbit closure O ¯ N when it is a hypersurface. The result thus gives new examples of normal orbit closures of quiver representations.

  2. Radiographic study of distal radial physeal closure in thoroughbred horses

    International Nuclear Information System (INIS)

    Vulcano, L.C.; Mamprim, M.J.; Muniz, L.M.R.; Moreira, A.F.; Luna, S.P.L.

    1997-01-01

    Monthly radiography was performed to study distal radial physeal closure in ten male and ten female Throughbred horses. The height, thoracic circumference and metacarpus circumference were also measured, Distal radial physeal closure time was sooner in females than males, and took 701 +/- 37 and 748 +/- 55 days respectively

  3. Responses of primary producers to mouth closure in the temporarily ...

    African Journals Online (AJOL)

    Responses of primary producers to mouth closure in the temporarily open/closed Great Brak Estuary in the warm-temperate region of South Africa. ... The response of primary producers to this prolonged period of mouth closure was investigated in 2010/2011. Urban and agricultural development in the river catchment and ...

  4. Vascularized fibular graft combined with vacuum assisted closure in ...

    African Journals Online (AJOL)

    The flowthrough fibular graft combined with Vacuum Assisted Closure (VAC) controlled the infection, shortened the course of treatment, and effectively restored limb function when applied to the treatment of tibial defects. Keywords: Tibial defect, Flow-through fibular graft, Vacuum Assisted Closure, Chronic Osteomyelitis ...

  5. The effectiveness of eye-closure in repeated interviews

    NARCIS (Netherlands)

    Vredeveldt, A.; Baddeley, A.D.; Hitch, G.J.

    2014-01-01

    Purpose Closing the eyes during recall can help witnesses remember more about a witnessed event. This study examined the effectiveness of eye-closure in a repeated recall paradigm with immediate free recall followed 1 week later by both free and cued recall. We examined whether eye-closure was more

  6. Mass extraction container closure integrity physical testing method development for parenteral container closure systems.

    Science.gov (United States)

    Yoon, Seung-Yil; Sagi, Hemi; Goldhammer, Craig; Li, Lei

    2012-01-01

    Container closure integrity (CCI) is a critical factor to ensure that product sterility is maintained over its entire shelf life. Assuring the CCI during container closure (C/C) system qualification, routine manufacturing and stability is important. FDA guidance also encourages industry to develop a CCI physical testing method in lieu of sterility testing in a stability program. A mass extraction system has been developed to check CCI for a variety of container closure systems such as vials, syringes, and cartridges. Various types of defects (e.g., glass micropipette, laser drill, wire) were created and used to demonstrate a detection limit. Leakage, detected as mass flow in this study, changes as a function of defect length and diameter. Therefore, the morphology of defects has been examined in detail with fluid theories. This study demonstrated that a mass extraction system was able to distinguish between intact samples and samples with 2 μm defects reliably when the defect was exposed to air, water, placebo, or drug product (3 mg/mL concentration) solution. Also, it has been verified that the method was robust, and capable of determining the acceptance limit using 3σ for syringes and 6σ for vials. Sterile products must maintain their sterility over their entire shelf life. Container closure systems such as those found in syringes and vials provide a seal between rubber and glass containers. This seal must be ensured to maintain product sterility. A mass extraction system has been developed to check container closure integrity for a variety of container closure systems such as vials, syringes, and cartridges. In order to demonstrate the method's capability, various types of defects (e.g., glass micropipette, laser drill, wire) were created in syringes and vials and were tested. This study demonstrated that a mass extraction system was able to distinguish between intact samples and samples with 2 μm defects reliably when the defect was exposed to air, water

  7. Closure of oroantral fistula using titanium plate with transalveolar wiring.

    Science.gov (United States)

    Ahmed, Wael Mohamed Said

    2015-03-01

    Alloplastic materials such as tantalum, gold plates and foils, hydroxyapatite blocks have been used for closure of oroantral fistula (OAF). However, these materials are not widely accepted in routine surgical closure of OAF due to cost, difficult handling, increased rate of infection, and exfoliation. To overcome the above drawbacks this study aimed to use titanium plates (0.3 mm) with transalveolar wiring fixation for closure of OAF. Ten patients with OAFs who consented to undergo this trial were selected and treated under an outpatient basis in the Oral Surgery Department, Faculty of Dentistry, Mansoura University, Egypt. All OAFs were successfully treated with no eventful complications. This study concludes that titanium plates with transalveolar wiring fixation is an excellent technique for closure of OAF. The high success rate with this technique warrants its use for closure of OAF.

  8. Bidirectional Barbed Sutures for Wound Closure: Evolution and Applications

    Science.gov (United States)

    Paul, Malcolm D.

    2009-01-01

    Traditionally, wound closure sutures have in common the need to tie knots with the inherent risk of extrusion, palpability, microinfarcts, breakage, and slippage. Bidirectional barbed sutures have barbs arrayed in a helical fashion in opposing directions on either side of an unbarbed midsegment. This suture is inserted at the midpoint of a wound and pulled through till resistance is encountered from the opposing barbs; each half of the suture is then advanced to the lateral ends of the wound. This design provides a method of evenly distributing tension along the incision line, a faster suture placement and closure time with no need to tie knots, and the possibility of improved cosmesis. Bidirectional barbed sutures, which are available in both absorbable and nonabsorbable forms, can be used for simple closures, multilayered closures, and closure of high-tension wounds in a variety of surgical settings. PMID:24527114

  9. 200 West Ash Pit Demolition Site closure plan

    International Nuclear Information System (INIS)

    1992-11-01

    The Hanford Facility is owned by the US Government and operated by the US Department of Energy, Richland Field Office. Dangerous waste and mixed waste (containing both radioactive and dangerous components) are managed and produced on the Hanford Facility. Westinghouse Hanford Company is a major contractor to the US Department of Energy, Richland Field Office and serves as cooperator of the 200 West Ash Pit Demolition Site, the unit addressed in this closure plan. The 200 West Ash Pit Demolition Site Closure Plan consists of a Part A Permit Application (Revision 3) and a closure plan. An explanation of the Part A Permit Application revision is provided at the beginning of the Part A section. The closure plan consists of nine chapters and three appendices. This 200 West Ash Pit Demolition Site Closure Plan submittal contains information current as of October 15, 1992

  10. Socket sclerosis--an obstacle for orthodontic space closure?

    Science.gov (United States)

    Baumgaertel, Sebastian

    2009-07-01

    Socket sclerosis is a rare reaction to tooth extraction resulting in high-density bone in the center of the alveolar process, where, under normal circumstances, cancellous bone is to be expected. In an adult orthodontic patient, routine extractions of the mandibular first permanent bicuspids were performed, resulting in socket sclerosis and unsuccessful orthodontic space closure. Orthodontic mini-implants were inserted to augment anchorage and aid in space closure. In the presence of socket sclerosis, conventional orthodontic mechanics failed to close the extraction spaces. However, with absolute anchorage in place, space closure occurred at a nearly normal rate. After treatment, no signs of socket sclerosis were discernible on the periapical radiographs. Socket sclerosis can be an obstacle for orthodontic space closure if traditional mechanics are employed. However, mini-implant-reinforced anchorage can lead to successful space closure, resulting in complete resolution of the sclerotic sites.

  11. Reliability in maintenance and design of elastomer sealed closures

    International Nuclear Information System (INIS)

    Lake, W.H.

    1978-01-01

    The methods of reliability are considered for maintenance and design of elastomer sealed containment closures. Component reliability is used to establish a replacement schedule for system maintenance. Reliability data on elastomer seals is used to evaluate the common practice of annual replacement, and to calculate component reliability values for several typical shipment time periods. System reliability methods are used to examine the relative merits of typical closure designs. These include single component and redundant seal closure, with and without closure verification testing. The paper presents a general method of quantifying the merits of closure designs through the use of reliability analysis, which is a probabilistic technique. The reference list offers a general source of information in the field of reliability, and should offer the opportunity to extend the procedures discussed in this paper to other design safety applications

  12. Single-site neural tube closure in human embryos revisited.

    Science.gov (United States)

    de Bakker, Bernadette S; Driessen, Stan; Boukens, Bastiaan J D; van den Hoff, Maurice J B; Oostra, Roelof-Jan

    2017-10-01

    Since the multi-site closure theory was first proposed in 1991 as explanation for the preferential localizations of neural tube defects, the closure of the neural tube has been debated. Although the multi-site closure theory is much cited in clinical literature, single-site closure is most apparent in literature concerning embryology. Inspired by Victor Hamburgers (1900-2001) statement that "our real teacher has been and still is the embryo, who is, incidentally, the only teacher who is always right", we decided to critically review both theories of neural tube closure. To verify the theories of closure, we studied serial histological sections of 10 mouse embryos between 8.5 and 9.5 days of gestation and 18 human embryos of the Carnegie collection between Carnegie stage 9 (19-21 days) and 13 (28-32 days). Neural tube closure was histologically defined by the neuroepithelial remodeling of the two adjoining neural fold tips in the midline. We did not observe multiple fusion sites in neither mouse nor human embryos. A meta-analysis of case reports on neural tube defects showed that defects can occur at any level of the neural axis. Our data indicate that the human neural tube fuses at a single site and, therefore, we propose to reinstate the single-site closure theory for neural tube closure. We showed that neural tube defects are not restricted to a specific location, thereby refuting the reasoning underlying the multi-site closure theory. Clin. Anat. 30:988-999, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  13. Comparing over-the-scope clip versus endoloop and clips (KING closure) for access site closure: a randomized experimental study

    Czech Academy of Sciences Publication Activity Database

    Martínek, J.; Ryska, O.; Tučková, I.; Filípková, T.; Doležel, R.; Juhás, Štefan; Motlík, Jan; Zavoral, M.; Ryska, M.

    2013-01-01

    Roč. 27, č. 4 (2013), s. 1203-1210 ISSN 0930-2794 R&D Projects: GA MZd NS9994 Institutional research plan: CEZ:AV0Z50450515 Keywords : NOTES * gastrotomy closure * rectotomy closure Subject RIV: FJ - Surgery incl. Transplants Impact factor: 3.313, year: 2013

  14. Occupational closure in nursing work reconsidered

    DEFF Research Database (Denmark)

    Traynor, Michael; Nissen, Nina; Lincoln, Carol

    2015-01-01

    In healthcare, occupational groups have adopted tactics to maintain autonomy and control over their areas of work. Witz described a credentialist approach to occupational closure adopted by nursing in the United Kingdom during the 19th and early 20th centuries. However, the recent advancement...... boundaries and a usurpatory stance towards these boundaries. Participants had usually been handpicked by managers and some were ambitious and confident in their abilities. Many aspired to train to be nurses claiming that they will gain recognition that they do not currently get but which they deserve....... Their scope of practice is based upon their managers' or supervisors' perception of their individual aptitude rather than on a credentialist claim. They 'usurp' nurses claim to be the healthcare worker with privileged access to patients, saying they have taken over what nursing has considered its core work...

  15. Automated Fuel Element Closure Welding System

    International Nuclear Information System (INIS)

    Wahlquist, D.R.

    1993-01-01

    The Automated Fuel Element Closure Welding System is a robotic device that will load and weld top end plugs onto nuclear fuel elements in a highly radioactive and inert gas environment. The system was developed at Argonne National Laboratory-West as part of the Fuel Cycle Demonstration. The welding system performs four main functions, it (1) injects a small amount of a xenon/krypton gas mixture into specific fuel elements, and (2) loads tiny end plugs into the tops of fuel element jackets, and (3) welds the end plugs to the element jackets, and (4) performs a dimensional inspection of the pre- and post-welded fuel elements. The system components are modular to facilitate remote replacement of failed parts. The entire system can be operated remotely in manual, semi-automatic, or fully automatic modes using a computer control system. The welding system is currently undergoing software testing and functional checkout

  16. Notice of car park and road closures

    CERN Multimedia

    2006-01-01

    The transfer of the two HF CMS detectors between Hall 186 and Point 5 (a convoy measuring 64 metres in length and weighing 440 tonnes) will result in the temporary closure of the following car parks: Building186: south entrance Building 613 Building 28 Building181 south entrance Building 600 Building 31 Route OPPENHEIMER The car parks concerned will be closed from Sunday 2 July until the evening of Tuesday 4 July and from Sunday 9 July until the evening of Tuesday 11 July 2006.Route FEYNMAN is also expected to be closed to traffic from mid-morning on Monday 3 July until the evening of Tuesday 4 July and from mid-morning on Monday 10 July until the evening of Tuesday 11 July (possible deviation via route FERMI and route RUTHERFORD).Thank you for your cooperation. TS-IC GroupTel. 163380 - 164043

  17. Notice of car park and road closures

    CERN Multimedia

    2006-01-01

    The transfer of the two HF CMS detectors between Hall 186 and Point 5 (a convoy measuring 64 metres in length and weighing 440 tonnes) will result in the temporary closure of the following car parks: Building186: south entrance Building 613 Building 28 Building181 south entrance Building 600 Building 31 Route OPPENHEIMER The car parks concerned will be closed from Sunday 2 July until the evening of Tuesday 4 July and from Sunday 9 July until the evening of Tuesday 11 July 2006. Route FEYNMAN is also expected to be closed to traffic from mid-morning on Monday 3 July until the evening of Tuesday 4 July and from mid-morning on Monday 10 July until the evening of Tuesday 11 July (possible deviation via route FERMI and route RUTHERFORD). Thank you for your cooperation. TS-IC Group Tel. 163380 - 164043

  18. Discursive Closure and Discursive Openings in Sustainability

    DEFF Research Database (Denmark)

    Christensen, Lars Thøger; Morsing, Mette; Thyssen, Ole

    2015-01-01

    Sustainability is an ambiguous and open-ended concept with many different meanings. Researchers as well as practitioners often express frustration with this fact and frequently call for more consistent, measurable, and univocal definitions of sustainability to ensure agreement, mutual understanding...... and explore new ideas and practices. Accepting conceptual ambiguity, in other words, is not necessarily to evade responsibility or critique. Whereas discursive closure may bind the concept to the past and make an organization blind to new and unexpected issues of sustainability problems, an open......, and collective action (Jahdi & Acikdilli, 2009; Kolk, 2003). This essay, by contrast, explores the potential of appreciating and embracing ambiguity in the sustainability arena. We argue that lack of a clear-cut sustainability definition has potential to mobilize stakeholders to challenge existing understandings...

  19. Closures for underground nuclear power plants

    International Nuclear Information System (INIS)

    1981-10-01

    This study demonstrates that, with the appropriate selection of an access concept on the underground nuclear power plant, it is possible to design a gate complying with the increased requirements of the construction of an underground nuclear power plant. The investigations revealed that a comparison leakage of 42 mm in diameter for the failure of seals is too conservative. When selecting suitable seals a leakage being more extensive than the above mentioned one can be prevented even in case of disturbance lasting several months. The closure structures of the personnel and material accesses do not represent any weak point within the concept of the construction method for underground nuclear power plants. (orig./HP)

  20. Closure head for a nuclear reactor

    International Nuclear Information System (INIS)

    Wade, E.E.

    1980-01-01

    A closure head for a nuclear reactor includes a stationary outer ring integral with the reactor vessel with a first rotatable plug disposed within the stationary outer ring and supported from the stationary outer ring by a bearing assembly. A sealing system is associated with the bearing assembly to seal the annulus defined between the first rotatable plug and the stationary outer ring. The sealing system comprises tubular seal elements disposed in the annulus with load springs contacting the tubular seal elements so as to force the tubular seal elements against the annulus in a manner to seal the annulus. The sealing system also comprises a sealing fluid which is pumped through the annulus and over the tubular seal elements causing the load springs to compress thereby reducing the friction between the tubular seal elements and the rotatable components while maintaining a gas-tight seal therebetween

  1. Frictionless segmented mechanics for controlled space closure.

    Science.gov (United States)

    Andrade, Ildeu

    2017-02-01

    Extraction spaces may be needed to achieve specific orthodontic goals of positioning the dentition in harmony with the craniofacial complex. However, the fundamental reality that determines the occlusion final position is the control exerted by the orthodontist while closing the extraction spaces. A specific treatment objective may require the posterior teeth to remain in a constant position anteroposteriorly as well as vertically, while the anterior teeth occupy the entire extraction site. Another treatment objective may require the opposite, or any number of intentional alternatives of extraction site closure. The present case report describes a simple controlled segmented mechanic system that permitted definable and predictable force systems to be applied and allowed to predict the treatment outcome with confidence. This case was presented to the Brazilian Board of Orthodontics and Dentofacial Orthopedics (BBO) in partial fulfillment of the requirements for Diplomate certification.

  2. Frictionless segmented mechanics for controlled space closure

    Directory of Open Access Journals (Sweden)

    Ildeu Andrade Jr

    Full Text Available ABSTRACT Extraction spaces may be needed to achieve specific orthodontic goals of positioning the dentition in harmony with the craniofacial complex. However, the fundamental reality that determines the occlusion final position is the control exerted by the orthodontist while closing the extraction spaces. A specific treatment objective may require the posterior teeth to remain in a constant position anteroposteriorly as well as vertically, while the anterior teeth occupy the entire extraction site. Another treatment objective may require the opposite, or any number of intentional alternatives of extraction site closure. The present case report describes a simple controlled segmented mechanic system that permitted definable and predictable force systems to be applied and allowed to predict the treatment outcome with confidence. This case was presented to the Brazilian Board of Orthodontics and Dentofacial Orthopedics (BBO in partial fulfillment of the requirements for Diplomate certification.

  3. Spontaneous closure of midline diastema following frenectomy

    Directory of Open Access Journals (Sweden)

    Koora Kiran

    2007-03-01

    Full Text Available Maxillary midline diastema is a common aesthetic problem in mixed and early permanent dentitions. The space can occur either as a transient malocclusion or created by developmental, pathological or iatrogenical factors. Many innovative therapies varying from restorative procedures such as composite build-up to surgery (frenectomies and orthodontics are available. Although literature says every frenectomy procedure should be preceded by orthodontic treatment, we opted for frenectomy technique without any orthodontic intervention. Presented herewith is a case report of a 9-year-old girl with a high frenal attachment that had caused spacing of the maxillary central incisors. A spontaneous closure of the midline diastema was noted within 2 months following frenectomy. The patient was followed up for 4 months after which the space remained closed and there was no necessity for an orthodontic treatment at a later stage.

  4. Mirtazapine-induced acute angle closure

    Directory of Open Access Journals (Sweden)

    Nilay Kahraman

    2015-01-01

    Full Text Available Acute angle closure (AAC is an ocular emergency with symptoms including blurred vision, eye pain, headache, nausea, vomiting and reddening of the eye those results from increased intraocular pressure. This clinical condition can lead to permanent damage in vision, thus causing blindness by generating progressive and irreversible optic neuropathy if left untreated. There are several reasons of AAC, including several types of local and systemic medications; mainly sympathomimetics, cholinergics, anti-cholinergics, mydriatics, anti-histamines, antiepileptics like topiramate, tricyclic and tetracyclic antidepressants, serotonin reuptake inhibitors, antipsychotics, sulfa-based drugs and anticoagulants. Mirtazapine, a noradrenergic and specific serotonergic antidepressant, is an atypical antidepressant with a complex pharmacological profile. This case report describes a patient with major depressive disorder, who experienced AAC after the first dosage of mirtazapine treatment, and highlights the importance of close monitoring of individuals under antidepressant treatment particularly immediately after initiation of the drug.

  5. Tonopah Test Range closure sites revegetation plan

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, D.C.; Hall, D.B.

    1997-05-01

    This document is a revegetation plan for long-term stabilization (revegetation) of land disturbed by activities associated with the closure of a Bomblet Pit and the Five Points Landfill. Both sites are on the Tonopah Test Range (TTR) located in south-central Nevada. This document contains general reclamation practices and procedures that will be followed during the revegetation of these sites. The revegetation procedures proposed have been developed over several years of research and include the results of reclamation trials at Area 11 and Area 19 on the Nevada Test Site (NTS), and more recently at the Double Tracks (Nellis Air Force Range) reclamation demonstration plots. In addition, the results of reclamation efforts and concurrent research efforts at the Yucca Mountain Project have been considered in the preparation of this revegetation plan.

  6. A clinical investigation of force delivery systems for orthodontic space closure.

    Science.gov (United States)

    Nightingale, C; Jones, S P

    2003-09-01

    To investigate the force retention, and rates of space closure achieved by elastomeric chain and nickel titanium coil springs. Randomized clinical trial. Eastman Dental Hospital, London and Queen Mary's University Hospital, Roehampton, 1998-2000. Twenty-two orthodontic patients, wearing the pre-adjusted edgewise appliance undergoing space closure in opposing quadrants, using sliding mechanics on 0.019 x 0.025-inch posted stainless steel archwires. Medium-spaced elastomeric chain [Durachain, OrthoCare (UK) Ltd., Bradford, UK] and 9-mm nickel titanium coil springs [OrthoCare (UK) Ltd.] were placed in opposing quadrants for 15 patients. Elastomeric chain only was used in a further seven patients. The initial forces on placement and residual forces at the subsequent visit were measured with a dial push-pull gauge [Orthocare (UK) Ltd]. Study models of eight patients were taken before and after space closure, from which measurements were made to establish mean space closure. The forces were measured in grammes and space closure in millimetres. Fifty-nine per cent (31/53) of the elastomeric sample maintained at least 50 per cent of the initial force over a time period of 1-15 weeks. No sample lost all its force, and the mean loss was 47 per cent (range: 0-76 per cent). Nickel titanium coil springs lost force rapidly over 6 weeks, following that force levels plateaued. Forty-six per cent (12/26) maintained at least 50 per cent of their initial force over a time period of 1-22 weeks, and mean force loss was 48 per cent (range: 12-68 per cent). The rate of mean weekly space closure for elastomeric chain was 0.21 mm and for nickel titanium coil springs 0.26 mm. There was no relationship between the initial force applied and rate of space closure. None of the sample failed during the study period giving a 100 per cent response rate. In clinical use, the force retention of elastomeric chain was better than previously concluded. High initial forces resulted in high force decay

  7. 303-K Storage Facility closure plan

    International Nuclear Information System (INIS)

    1993-01-01

    Recyclable scrap uranium with zircaloy-2 and copper silicon alloy, uranium-titanium alloy, beryllium/zircaloy-2 alloy, and zircaloy-2 chips and fines were secured in concrete billets (7.5-gallon containers) in the 303-K Storage Facility, located in the 300 Area. The beryllium/zircaloy-2 alloy and zircaloy-2 chips and fines are designated as mixed waste with the characteristic of ignitability. The concretion process reduced the ignitability of the fines and chips for safe storage and shipment. This process has been discontinued and the 303-K Storage Facility is now undergoing closure as defined in the Resource Conservation and Recovery Act (RCRA) of 1976 and the Washington Administrative Code (WAC) Dangerous Waste Regulations, WAC 173-303-040. This closure plan presents a description of the 303-K Storage Facility, the history of materials and waste managed, and the procedures that will be followed to close the 303-K Storage Facility. The 303-K Storage Facility is located within the 300-FF-3 (source) and 300-FF-5 (groundwater) operable units, as designated in the Hanford Federal Facility Agreement and Consent Order (Tri-Party Agreement) (Ecology et al. 1992). Contamination in the operable units 300-FF-3 and 300-FF-5 is scheduled to be addressed through the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) of 1980 remedial action process. Therefore, all soil remedial action at the 304 Facility will be conducted as part of the CERCLA remedial action of operable units 300-FF-3 and 300-FF-5

  8. ICPP tank farm closure study. Volume 1

    International Nuclear Information System (INIS)

    Spaulding, B.C.; Gavalya, R.A.; Dahlmeir, M.M.

    1998-02-01

    The disposition of INEEL radioactive wastes is now under a Settlement Agreement between the DOE and the State of Idaho. The Settlement Agreement requires that existing liquid sodium bearing waste (SBW), and other liquid waste inventories be treated by December 31, 2012. This agreement also requires that all HLW, including calcined waste, be disposed or made road ready to ship from the INEEL by 2035. Sodium bearing waste (SBW) is produced from decontamination operations and HLW from reprocessing of SNF. SBW and HLW are radioactive and hazardous mixed waste; the radioactive constituents are regulated by DOE and the hazardous constituents are regulated by the Resource Conservation and Recovery Act (RCRA). Calcined waste, a dry granular material, is produced in the New Waste Calcining Facility (NWCF). Two primary waste tank storage locations exist at the ICPP: Tank Farm Facility (TFF) and the Calcined Solids Storage Facility (CSSF). The TFF has the following underground storage tanks: four 18,400-gallon tanks (WM 100-102, WL 101); four 30,000-gallon tanks (WM 103-106); and eleven 300,000+ gallon tanks. This includes nine 300,000-gallon tanks (WM 182-190) and two 318,000 gallon tanks (WM 180-181). This study analyzes the closure and subsequent use of the eleven 300,000+ gallon tanks. The 18,400 and 30,000-gallon tanks were not included in the work scope and will be closed as a separate activity. This study was conducted to support the HLW Environmental Impact Statement (EIS) waste separations options and addresses closure of the 300,000-gallon liquid waste storage tanks and subsequent tank void uses. A figure provides a diagram estimating how the TFF could be used as part of the separations options. Other possible TFF uses are also discussed in this study

  9. ICPP tank farm closure study. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Spaulding, B.C.; Gavalya, R.A.; Dahlmeir, M.M. [and others

    1998-02-01

    The disposition of INEEL radioactive wastes is now under a Settlement Agreement between the DOE and the State of Idaho. The Settlement Agreement requires that existing liquid sodium bearing waste (SBW), and other liquid waste inventories be treated by December 31, 2012. This agreement also requires that all HLW, including calcined waste, be disposed or made road ready to ship from the INEEL by 2035. Sodium bearing waste (SBW) is produced from decontamination operations and HLW from reprocessing of SNF. SBW and HLW are radioactive and hazardous mixed waste; the radioactive constituents are regulated by DOE and the hazardous constituents are regulated by the Resource Conservation and Recovery Act (RCRA). Calcined waste, a dry granular material, is produced in the New Waste Calcining Facility (NWCF). Two primary waste tank storage locations exist at the ICPP: Tank Farm Facility (TFF) and the Calcined Solids Storage Facility (CSSF). The TFF has the following underground storage tanks: four 18,400-gallon tanks (WM 100-102, WL 101); four 30,000-gallon tanks (WM 103-106); and eleven 300,000+ gallon tanks. This includes nine 300,000-gallon tanks (WM 182-190) and two 318,000 gallon tanks (WM 180-181). This study analyzes the closure and subsequent use of the eleven 300,000+ gallon tanks. The 18,400 and 30,000-gallon tanks were not included in the work scope and will be closed as a separate activity. This study was conducted to support the HLW Environmental Impact Statement (EIS) waste separations options and addresses closure of the 300,000-gallon liquid waste storage tanks and subsequent tank void uses. A figure provides a diagram estimating how the TFF could be used as part of the separations options. Other possible TFF uses are also discussed in this study.

  10. [Vacuum assisted closure in open abdomen and deferred closure: experience in 23 patients].

    Science.gov (United States)

    Pérez Domínguez, Lucinda; Pardellas Rivera, Hermelinda; Cáceres Alvarado, Nieves; López Saco, Angel; Rivo Vázquez, Angel; Casal Núñez, Enrique

    2012-10-01

    We analyse our experience and the results obtained with the use of vacuum assisted closure (VAC(®), KCI Clinic Spain SL) in the management of open abdomen. We retrospectively reviewed the laparostomies performed between June 2006 and March 2011 using VAC(®) treatment in the Hospital Xeral-Cíes, Vigo. We included 23 consecutive patients (18 males and 5 females) on whom the VAC(®) was used in the open abdomen due to different indications (abdominal trauma, peritonitis, pancreatitis, ischaemic disease or abdominal compartmental syndrome). The VAC(®) needed changing a mean of 3.1 times per patient (range 1-7), with total mean treatment duration of 14.8 days (2-43) until closure, primary closure being achieved in 18 out of 21 patients (86%). The mean hospital stay was 110.1 days (8-163) and 6 patients (26%) died during their hospital stay due to problems related to their underlying disease. Seven cases (30%) had complications during the VAC® therapy: 3 intra-abdominal abscesses (13%), 4 fistulas or suture dehiscence (17%), and 1 evisceration (4%). VAC(®) therapy is simple to manage, with an acceptable rate of complication, particularly of intestinal fistulas, and a reduced mortality. Of the various systems available for the deferred closure of the abdomen, the VAC(®) has made considerable progress in the past few years, mainly due to its adaptable material, and its numerous advantages. Its use will possibly increase in the future. Copyright © 2011 AEC. Published by Elsevier Espana. All rights reserved.

  11. Performance Objective for Tank Farm Closure Risk Assessments

    International Nuclear Information System (INIS)

    MANN, F.M.; KNEPP, A.J.; BADDEN, J.

    2003-01-01

    To be meaningful, results from a numeric risk assessment of the consequences of an action must be compared against the standards for such an action. That is, before one disposes of waste or closes a facility with waste, one must show that the disposal or closure action protects the public health and safety and the environment. These standards are called performance objectives. Regulations requiring performing performance assessments, (whether federal ones like the Department of Energy [DOE] Order 435.1, Radioactive Waste Management and its implementing guides or Washington State ones like the regulations implementing the Washington Administrative Code [WAC] 173-340 ''Model Toxics Control Act - Cleanup''), usually require that the determination of performance objectives be one of the first steps performed. These performance objectives not only set comparison level for the numeric results, but also define the media, pathways, exposure scenarios (receptors), spatial locations, and times that the performance assessment must consider. Thus, a performance objective consists of a compliance level, place(s) of compliance, and time(s) of compliance. Performance objectives are not the levels that a regulatory agency will enforce in a permit or authorization. Those levels, often called enforcement levels, will be set in the permit or authorization. Rather, performance objectives are those levels against which the results of the numeric simulation will be compared to judge the success of the proposed cleanup or disposal actions. Additional comparison levels may be requested for information purposes, but are not officially part of the decision on the adequacy of the proposed action. To emphasize that the performance objectives discussed in this document are not regulatory performance objectives, the three components of the performance objective will be renamed in this document as assessment standard, point(s) of assessment, and time(s) of assessment. However, whenever

  12. Influence of embedded fibers and an epithelium layer on glottal closure pattern in a physical vocal fold modela)

    Science.gov (United States)

    Xuan, Yue; Zhang, Zhaoyan

    2013-01-01

    Purpose To explore the possible structural and material property features that may facilitate complete glottal closure in an otherwise isotropic physical vocal fold model. Method Seven vocal fold models with different structural features were used in this study. An isotropic model was used as the baseline model, and other models were modified from the baseline model by either embedding fibers aligned along the anterior-posterior direction in the body or cover layer, adding a stiffer outer layer simulating the epithelium layer, or a combination of the two features. Phonation tests were performed with both aerodynamic and acoustic measurements and high-speed imaging of vocal fold vibration. Results Compared to the isotropic one-layer model, the presence of a stiffer epithelium layer led to complete glottal closure along the anterior-posterior direction and strong excitation of high-order harmonics in the resulting acoustic spectra. Similar improvements were observed with fibers embedded in the cover layer, but to a lesser degree. Presence of fibers in the body layer did not yield noticeable improvements in glottal closure or harmonic excitation. Conclusions This study shows that the presence of collagen and elastin fibers and the epithelium layer may play a critical role in achieving complete glottal closure. PMID:24167236

  13. Soil sampling and analysis plan for the 3718-F Alkali Metal Treatment and Storage Facility closure activities

    Energy Technology Data Exchange (ETDEWEB)

    Sonnichsen, J.C.

    1997-05-01

    Amendment V.13.B.b to the approved closure plan (DOE-RL 1995a) requires that a soil sampling and analysis plan be prepared and submitted to the Washington State Department of Ecology (Ecology) for review and approval. Amendment V.13.B.c requires that a diagram of the 3718-F Alkali Metal Treatment and Storage Facility unit (the treatment, storage, and disposal [TSD] unit) boundary that is to be closed, including the maximum extent of operation, be prepared and submitted as part is of the soil sampling and analysis plan. This document describes the sampling and analysis that is to be performed in response to these requirements and amends the closure plan. Specifically, this document supersedes Section 6.2, lines 43--46, and Section 7.3.6 of the closure plan. Results from the analysis will be compared to cleanup levels identified in the closure plan. These cleanup levels will be established using residential exposure assumptions in accordance with the Model Toxics Control Act (MTCA) Cleanup Regulation (Washington Administrative Code [WAC] 173-340) as required in Amendment V.13.B.I. Results of all sampling, including the raw analytical data, a summary of analytical results, a data validation package, and a narrative summary with conclusions will be provided to Ecology as specified in Amendment V.13.B.e. The results and process used to collect and analyze the soil samples will be certified by a licensed professional engineer. These results and a certificate of closure for the balance of the TSD unit, as outlined in Chapter 7.0 of the approved closure plan (storage shed, concrete pad, burn building, scrubber, and reaction tanks), will provide the basis for a closure determination.

  14. Soil sampling and analysis plan for the 3718-F Alkali Metal Treatment and Storage Facility closure activities

    International Nuclear Information System (INIS)

    Sonnichsen, J.C.

    1997-01-01

    Amendment V.13.B.b to the approved closure plan (DOE-RL 1995a) requires that a soil sampling and analysis plan be prepared and submitted to the Washington State Department of Ecology (Ecology) for review and approval. Amendment V.13.B.c requires that a diagram of the 3718-F Alkali Metal Treatment and Storage Facility unit (the treatment, storage, and disposal [TSD] unit) boundary that is to be closed, including the maximum extent of operation, be prepared and submitted as part is of the soil sampling and analysis plan. This document describes the sampling and analysis that is to be performed in response to these requirements and amends the closure plan. Specifically, this document supersedes Section 6.2, lines 43--46, and Section 7.3.6 of the closure plan. Results from the analysis will be compared to cleanup levels identified in the closure plan. These cleanup levels will be established using residential exposure assumptions in accordance with the Model Toxics Control Act (MTCA) Cleanup Regulation (Washington Administrative Code [WAC] 173-340) as required in Amendment V.13.B.I. Results of all sampling, including the raw analytical data, a summary of analytical results, a data validation package, and a narrative summary with conclusions will be provided to Ecology as specified in Amendment V.13.B.e. The results and process used to collect and analyze the soil samples will be certified by a licensed professional engineer. These results and a certificate of closure for the balance of the TSD unit, as outlined in Chapter 7.0 of the approved closure plan (storage shed, concrete pad, burn building, scrubber, and reaction tanks), will provide the basis for a closure determination

  15. Suture Closure versus Non-Closure of Subcutaneous Fat and Cosmetic Outcome after Cesarean Section: A Randomized Controlled Trial.

    Directory of Open Access Journals (Sweden)

    Heinrich Husslein

    Full Text Available To investigate the effect of subcutaneous fat suture closure versus non-closure at cesarean section (CS on long-term cosmetic outcome.Women undergoing planned or unplanned CS were randomized to either subcutaneous fat suture closure or non-closure using a 1∶1 allocation algorithm. Participants and outcome assessors were blinded to group allocation. Scar evaluation was performed after two and six months. Primary outcome measures were Patient and Observer Scar Assessment Scale (POSAS summary scores six months after surgery. Secondary outcome measures were Vancouver Scar Scale (VSS summary scores, retraction of the scar below the level of the surrounding skin, duration of surgery, and development of hematoma, seroma, surgical site infection (SSI or wound disruption. Data were analyzed according to the intention to treat principle.A total of 116 women were randomized and 91 participants, 47 in the closure and 44 in the non-closure group, completed the trial and were analyzed. There were no differences in patient morphometrics or surgery indications between groups. At two and six months no significant differences were found with respect to POSAS or VSS scores between groups. After two months significantly more women in the non-closure group described their scar as being retracted below the level of the skin (36% vs. 15%, p = 0.02 whereas no difference was observed at six months. There were significantly more hematomas in the non-closure (25% compared to the closure group (4% (p = 0.005. There was no difference in duration of surgery, SSI, seroma formation or wound disruption between groups.Suture closure of the subcutaneous fat at CS does not affect long-term cosmetic outcome. (Level I evidence.ClinicalTrials.gov NCT01542346.

  16. In-Situ Testing and Performance Assessment of a Redesigned WIPP Panel Closure - 13192

    International Nuclear Information System (INIS)

    Klein, Thomas; Patterson, Russell; Camphouse, Chris; Herrick, Courtney; Kirchner, Thomas; Malama, Bwalya; Zeitler, Todd; Kicker, Dwayne

    2013-01-01

    operations and a greater understanding of the waste and the behavior of the underground salt formation, the DOE has established a revised panel closure design. This revised design meets both the short-term NMED Permit requirements for the operational period, and also the Federal requirements for long-term repository performance. This new design is simpler, easier to construct and has less of an adverse impact on waste disposal operations than the originally approved Option D design. The Panel Closure Redesign is based on: (1) the results of in-situ constructability testing performed to determine run-of-mine salt reconsolidation parameters and how the characteristics of the bedded salt formation affect these parameters and, (2) the results of air flow analysis of the new design to determine that the limit for the migration of Volatile Organic Compounds (VOCs) will be met at the compliance point. Waste panel closures comprise a repository feature that has been represented in WIPP performance assessment (PA) since the original Compliance Certification Application of 1996. Panel closures are included in WIPP PA models principally because they are a part of the disposal system, not because they play a substantive role in inhibiting the release of radionuclides to the outside environment. The 1998 rulemaking that certified WIPP to receive transuranic waste placed conditions on the panel closure design to be implemented in the repository. The revised panel closure design, termed the Run-of-Mine (ROM) Panel Closure System (ROMPCS), is comprised of 30.48 meters of ROM salt with barriers at each end. The ROM salt is generated from ongoing mining operations at the WIPP and may be compacted and/or moistened as it is emplaced in a panel entry. The barriers consist of bulkheads, similar to those currently used in the panels as room closures. A WIPP performance assessment has been completed that incorporates the ROMPCS design into the representation of the repository, and compares

  17. Influence of Closure & Non-Closure of the Visceral and Parietal Peritoneum on Post Cesarean Morbidity

    Directory of Open Access Journals (Sweden)

    Tabasi Z.

    2010-01-01

    Full Text Available AbstractBackground and Objectives: One of the most important issues in promoting mother and child health is reducing the morbidity rate after cesarean section. The aim of this study was to investigate the influence of closure and non-closure of the visceral and parietal peritoneum on post cesarean morbidity in women attending Shabihkhani Maternity Hospital in Kashan, Iran.Methods: This study was conducted with a single blind randomized clinical trial method on 100 parturient women that underwent emergency or elective cesarean section. Patients with previous cesarean section and or abdominal surgery, diseases such as hypertension, diabetes mellitus and premature rupture of membrane and pre operative bleeding, were excluded from this study. Then, the participants were randomly divided into two groups: in one group both peritoneal layers were closed while in the other group, they were not closed. Post operative morbidity including fever, bleeding, post operative pain, analgesic consumption and time of operation were assessed. Data were analyzed with t-tests, and χ2 and a P<0.05 were considered significant.Results: In this study, there were no significant differences between the two groups with respect to age, gestational age, the reason for caesarean section and gravidity, nor were there any differences with respect to the incidence of fever or bleeding and was similar between the two groups, but there was a significant difference between the two groups regarding to feeling of severe pain (P=0.0003, analgesic consumption (P=0.0003 and time of operation (P=0.004. In the non-closure group, dose of analgesic drugs, pain severity and time of operation were less than those of the other group.Conclusion: The Findings showed that non-closure of peritoneal layers as a shorter and simpler procedure has no influence on increasing post cesarean morbidity. Therefore, due to maternal health promotion and early neonatal breastfeeding, non closure of peritoneal

  18. Influence of Closure & Non-Closure of the Visceral and Parietal Peritoneum on Post Cesarean Morbidity

    Directory of Open Access Journals (Sweden)

    Z Tabasi

    2012-05-01

    Full Text Available

    Background and Objectives: One of the most important issues in promoting mother and child health is reducing the morbidity rate after cesarean section. The aim of this study was to investigate the influence of closure and non-closure of the visceral and parietal peritoneum on post cesarean morbidity in women attending Shabihkhani Maternity Hospital in Kashan, Iran.

    Methods: This study was conducted with a single blind randomized clinical trial method on 100 parturient women that underwent emergency or elective cesarean section. Patients with previous cesarean section and or abdominal surgery, diseases such as hypertension, diabetes mellitus and premature rupture of membrane and pre operative bleeding, were excluded from this study. Then, the participants were randomly divided into two groups: in one group both peritoneal layers were closed while in the other group, they were not closed. Post operative morbidity including fever, bleeding, post operative pain, analgesic consumption and time of operation were assessed. Data were analyzed with t-tests, and χ2 and a P<0.05 were considered significant.

    Results: In this study, there were no significant differences between the two groups with respect to age, gestational age, the reason for caesarean section and gravidity, nor were there any differences with respect to the incidence of fever or bleeding and was similar between the two groups, but there was a significant difference between the two groups regarding to feeling of severe pain (P=0.0003, analgesic consumption (P=0.0003 and time of operation (P=0.004. In the non-closure group, dose of analgesic drugs, pain severity and time of operation were less than those of the other group.

    Conclusion: The
  19. Secondary Intention Healing and Purse-String Closures.

    Science.gov (United States)

    Lam, Thomas K; Lowe, Christopher; Johnson, Ryan; Marquart, Jason D

    2015-10-01

    Secondary intention healing and purse-string closures are simple but extremely useful methods for the dermatologic surgeon to master. To review the literature on the use of these two types of closures and offer recommendations based on our collective experiences. A literature review was performed using the terms "secondary intention healing" and "purse-string closure." The evidence and recommendations from the resultant references were summarized in our article and synthesized with our own experiences. Twenty-eight sources were cited overall with fifteen related to secondary intention healing, eleven pertaining to purse-string closures, and one randomized, blind clinical trial comparing the two modalities. The art of dermatologic surgery often requires a tailored approach to the patient and can involve a spectrum of closures, from the simplest to most complex. This variety not only provides more reconstruction options, but are also necessary to keep dermatologic surgery cost-effective. Certain locations or situations are more amenable for these two types of closures than others. The use of secondary intention healing, either alone or in conjunction with purse-string closures, should be in every dermatologic surgeon's armamentarium.

  20. Comparison of Outcomes between Early Fascial Closure and Delayed Abdominal Closure in Patients with Open Abdomen: A Systematic Review and Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Yu Chen

    2014-01-01

    Full Text Available Up to the present, the optimal time to close an open abdomen remains controversial. This study was designed to evaluate whether early fascial abdominal closure had advantages over delayed approach for open abdomen populations. Medline, Embase, and Cochrane Library were searched until April 2013. Search terms included “open abdomen,” “abdominal compartment syndrome,” “laparostomy,” “celiotomy,” “abdominal closure,” “primary,” “delayed,” “permanent,” “fascial closure,” and “definitive closure.” Open abdomen was defined as “fail to close abdominal fascia after a laparotomy.” Mortality, complications, and length of stay were compared between early and delayed fascial closure. In total, 3125 patients were included for final analysis, and 1942 (62% patients successfully achieved early fascial closure. Vacuum assisted fascial closure had no impact on pooled fascial closure rate. Compared with delayed abdominal closure, early fascial closure significantly reduced mortality (12.3% versus 24.8%, RR, 0.53, P<0.0001 and complication incidence (RR, 0.68, P<0.0001. The mean interval from open abdomen to definitive closure ranged from 2.2 to 14.6 days in early fascial closure groups, but from 32.5 to 300 days in delayed closure groups. This study confirmed clinical advantages of early fascial closure over delayed approach in treatment of patients with open abdomen.

  1. Tracheocutaneous Fistula Closure with Turnover Flap and Polydioxanone Plate

    Directory of Open Access Journals (Sweden)

    Justin R. Bryant, DO, MBA

    2017-10-01

    Full Text Available Summary:. An alternative surgical treatment is proposed for closure of tracheocutaneous fistulas. The authors present a new technique for reconstruction of persistent tracheocutaneous fistula resultant from temporary tracheostomy. The single-stage closure under local anesthesia involves a fistulous tract turnover flap with a perforated 0.15 mm polydioxanone plate between the flap and the subcutaneous closure. This article presents 3 cases of persistent tracheocutaneous fistula treated by this method. At follow-up examination after follow-up, no recurrent fistula formation had occurred, and no respiratory deformity was present.

  2. Closure of a mixed waste landfill: Lessons learned

    International Nuclear Information System (INIS)

    Phifer, M.A.

    1990-01-01

    Much experience has been gained during the closure of the Mixed Waste Management Facility (MWMF) at the Savannah River Site (SRS) and many lessons were learned. This knowledge was applied to other closures at SRS yielding decreased costs, schedule enhancement, and increased overall project efficiency. The next major area of experience to be gained at SRS in the field of waste site closures will be in the upkeep, maintenance, and monitoring of clay caps. Further test programs will be required to address these requirements

  3. Progress on the social impact of Ignalina NPP closure

    International Nuclear Information System (INIS)

    Ryding, H.

    2002-01-01

    The Parliament has passed a closure plan, the Decommissioning Programme, which covers all the technical measures needed for closure and some of the other measures needed to deal with the social and economic impact of closure on the three towns nearby: Ignalina, Zarasai and Visaginas. For the social impact, considerable EU funds are now available under the Phare Programme to assist with planning and development in, Utena region. Bilateral donors are also active in this area, especially Sweden Denmark, UK and Germany. After EU entry, Lithuania will be eligible for billions of Euros in assistance from the Structural Funds

  4. Predictors of successful closure of patent ductus arteriosus with indomethacin.

    Science.gov (United States)

    Ahamed, M F; Verma, P; Lee, S; Vega, M; Wang, D; Kim, M; Fuloria, M

    2015-09-01

    To determine whether platelet counts can predict the likelihood of successful closure of patent ductus arteriosus (PDA) with indomethacin. This was a retrospective cohort study of infants gender (odds ratio=3.02; 95% confidence interval: 1.08 to 8.49) and higher platelet count (odds ratio=1.5; 95% confidence interval: 1.04 to 2.17) prior to indomethacin treatment were associated with successful ductal closure with indomethacin. Older GA, male gender and higher platelet count at time of treatment of hemodynamically significant PDA are predictors of successful ductal closure with indomethacin.

  5. History of Sandia National Laboratories` auxiliary closure mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Weydert, J.C. [Sandia National Labs., Albuquerque, NM (United States); Ponder, G.M. [Geo-Centers, Inc., Albuquerque, NM (United States)

    1993-12-01

    An essential component of a horizontal, underground nuclear test setup at the Nevada Test Site is the auxiliary closure system. The massive gates that slam shut immediately after a device has been detonated allow the prompt radiation to pass, but block debris and hot gases from continuing down the tunnel. Thus, the gates protect experiments located in the horizontal line-of-sight steel pipe. Sandia National Laboratories has been the major designer and developer of these closure systems. This report records the history of SNL`s participation in and contributions to the technology of auxiliary closure systems used in horizontal tunnel tests in the underground test program.

  6. Site closure management strategies and the responsiveness of conservation outcomes in recreational fishing.

    Science.gov (United States)

    Gao, Lei; Hailu, Atakelty

    2018-02-01

    We develop and use an empirically based model, which integrates fishing behaviour and a coral reef system, to evaluate outcomes from site closure strategies to manage the effects of recreational fishing. The model is designed to estimate management effects in complex settings with two-way feedback effects (between fishing and ecosystem dynamics) as well as spillover effects where the closure of a site (or sites) leads to the redistribution of fishing effort. An iconic coral reef system is used as a case study. The results demonstrate that some site closure strategies provide little incremental benefits over less stringent approaches. They also show that some strategies targeting more sites are actually inferior to more limited strategies, demonstrating that, in the analysis of complex problems involving feedback effects and substitutions, there is little substitute for the use of empirically based and sound modelling as the basis for informed conservation decision making and stakeholder consultation. These findings have direct relevance not only for policies aimed at improving recreational fishing management but also for securing the supply of marine ecosystem services. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Comparison of Anterior Segment-Optical Coherence Tomography Parameters in Phacomorphic Angle Closure and Acute Angle Closure Eyes.

    Science.gov (United States)

    Moghimi, Sasan; Ramezani, Farshid; He, Mingguang; Coleman, Anne L; Lin, Shan C

    2015-12-01

    The purpose of this study is to compare anterior segment-optical coherence tomography (AS-OCT) parameters in phacomorphic angle closure and acute primary angle closure (APAC) eyes. In this cross-sectional case series, a total of 134 patients with phacomorphic angle closure (28 eyes) or APAC (54 eyes), as well as normal control subjects (52 eyes), were enrolled. Patients underwent AS-OCT imaging and A-scan biometry of both eyes. Anterior chamber depth (ACD), anterior chamber area (ACA), iris thickness (IT), iris curvature, lens vault (LV), anterior vault (AV), and angle parameters including angle opening distance (AOD 500 and AOD750) and trabecular iris space area (TISA500 and TISA750) were measured in qualified images using the Zhongshan Angle Assessment Program and compared among eyes with phacomorphic angle closure, APAC, and normal control subjects. Phacomorphic angle closure and APAC eyes had smaller AOD, ACD, ACA, ACW, AV, and posterior corneal arc length and greater LV than normal controls (P APAC eyes: ACD 1042 μm (OR,12.12; P APAC eyes. In multivariate analysis, ACD, LV, AOD500, and axial length could significantly distinguish the two entities. Ocular biometric parameters can differentiate phacomorphic angle closure from APAC eyes. Shallower ACD and greater LV, axial length, and ACA are the main parameters that distinguish phacomorphic angle closure from APAC.

  8. Linking valve closure behavior and sodium transport mechanism in freshwater clam Corbicula fluminea in response to copper

    Energy Technology Data Exchange (ETDEWEB)

    Liao, C.-M. [Department of Bioenvironmental Systems Engineering, National Taiwan University, 1, Sec. 4, Roosevelt Road, Taipei, Taiwan 10617 (China)]. E-mail: cmliao@ntu.edu.tw; Lin, C.-M. [Department of Bioenvironmental Systems Engineering, National Taiwan University, 1, Sec. 4, Roosevelt Road, Taipei, Taiwan 10617 (China); Jou, L.-J. [Department of Bioenvironmental Systems Engineering, National Taiwan University, 1, Sec. 4, Roosevelt Road, Taipei, Taiwan 10617 (China); Department of Biomechatronic Engineering, National Ilan University, Ilan, Taiwan 260 (China); Chiang, K.-C. [Department of Bioenvironmental Systems Engineering, National Taiwan University, 1, Sec. 4, Roosevelt Road, Taipei, Taiwan 10617 (China)

    2007-06-15

    The purpose of this study is to develop a mechanistic model to describe a conceptually new 'flux-biological response' approach based on biotic ligand model (BLM) and Michaelis-Menten (M-M) kinetics to allow the linkage between valve closure behavior and sodium (Na) transport mechanism in freshwater clam Corbicula fluminea in response to waterborne copper (Cu). We test the proposed model against published data regarding Na uptake kinetics in rainbow trout and Na uptake profile in C. fluminea, confirming that the predictive model is robust. Here, we show that the predicted M-M maximum Cu internalization flux in C. fluminea is 0.369 {mu}mol g{sup -1} h{sup -1} with a half-saturation affinity constant of 7.87 x 10{sup -3} {mu}M. Dynamics of Na uptake and valve closure daily rhythm driven by external Cu can also be predicted simultaneously. We suggest that this 'Na transport-valve closure behavior' approach might provide the basis of a future design of biomonitoring tool. - A new flux-biological response model can link valve closure and sodium transport mechanisms in freshwater clam in response to copper.

  9. Ultrasound biomicroscopic features associated with angle closure in fellow eyes of acute primary angle closure after laser iridotomy.

    Science.gov (United States)

    Yao, Bao-qun; Wu, Ling-ling; Zhang, Chun; Wang, Xin

    2009-03-01

    To investigate the frequency of appositional angle closure and related anatomic characteristics in fellow eyes of Chinese subjects with acute primary angle closure (APAC) after laser peripheral iridotomy (LPI). Cross-sectional study. Consecutive subjects with APAC presenting from April 2006 to September 2006 at the Glaucoma Service of Peking University Eye Center, Peking University Third Hospital. Under dark conditions, fellow eyes were divided into 2 groups based on the detection of appositional angle closure by ultrasound biomicroscopy (UBM). For all subjects, UBM parameters were measured to evaluate the different anatomic features between the 2 groups. Darkroom provocative tests (DRPTs) and gonioscopy were performed to investigate the relationship between angle closure and intraocular pressure. Central anterior chamber depth (ACD); angle opening distance(500) (AOD(500)); angle recess area(750) (ARA(750)); trabecular-iris angle (T-I angle); trabecular-ciliary process distance (TCPD); peripheral iris thickness (IT(1)); iris-zonule distance (IZD); and the position of the iris insertion. Thirty-four post-LPI fellow eyes of 34 patients with APAC (8 men, 26 women; mean +/- standard deviation age 66.3+/-7.2 years, range 54-83) were included. Peripheral anterior synechiae (PAS) were not observed in any subject. Appositional angle closure was observed in at least 1 quadrant in 13 (38.2%) of the 34 patients. Compared with eyes without appositional closure, eyes with appositional closure showed significantly lower AOD(500), ARA(750), and T-I angle in 4 quadrants; shorter TCPD in the inferior and temporal quadrants; and thicker IT(1) in the superior and nasal quadrants (PAPAC showed appositional angle closure after LPI. The anatomic findings indicate a narrower angle, a more anterior position of the ciliary body, and a thicker peripheral iris in fellow eyes of APAC after LPI may be associated with an increased risk for progressive angle closure.

  10. Case Report: Rapid staged abdominal closure using Gore-Tex® mesh as a bridge to primary omphalocele sac closure

    Directory of Open Access Journals (Sweden)

    William C. Kethman

    2016-06-01

    Full Text Available Omphaloceles present an ongoing challenge due to significant variations in presentation and associated co-morbidities. Diverse management strategies have been described to tackle many of the fundamental challenges of closure and reconstruction of the abdominal wall – this fact demonstrates a need for increasingly individualized management options for this complex disease. We describe a novel method of rapid staged abdominal wall closure using Gore-Tex® mesh as a bridge to primary omphalocele closure in an infant with partial Pentalogy of Cantrell and giant ruptured omphalocele. This strategy can be used in management of some of the most complex abdominal wall defects.

  11. IT Services availability during CERN annual closure

    CERN Multimedia

    2003-01-01

    Mail, Cern Windows (NICE ),  Web services,  LXPLUS, LXBATCH, Automated tape devices, Castor, Backups, software license servers, Sundev, CVS and Print Servers, CDS and Agenda-Maker, EDMS (in collaboration with EST Division), CMS disc servers, Campus Network,  Remedy, Security and VPN services will be available during the CERN annual closure. The physics database cluster, replication location service as well as accdb, cerndb and admsdb are the only databases available, CCDB will be closed for public access. Problems developing on scheduled services should be addressed within about half a day except around  Christmas Eve and Christmas Day ( 24 and 25th December ) and New Year's Eve and New Years Day (31st December and 1st Janauary. All other services will be left running mostly unattended. No interruptions are scheduled but restoration of the service in case of failure cannot be guaranteed. Please note that the Helpdesk will be closed, that no file restores from backups will be possible and damaged tapes wi...

  12. Effect of Bronchial Thermoplasty on Airway Closure

    Directory of Open Access Journals (Sweden)

    Robert Brown

    2007-01-01

    Full Text Available Background Bronchial Thermoplasty, a procedure that applies thermal energy to the airway wall has been shown to impair the ability of airway to contract in response to methacholine chloride (Mch. The technique has been advocated as an alternative treatment for asthma that may permanently limit airway narrowing. In previous experimental studies in dogs and humans, it was shown that those airways treated with bronchial thermoplasty had significant impairment of Mch responsiveness. Methods In the present study, we investigated the ability of canine airways to close completely with very high concentrations of Mch after bronchial thermoplasty. Bronchial thermoplasty was performed on dogs using the Alair System, comprising a low power RF controller and a basket catheter with four electrodes. A local atomization of Mch agonist was delivered directly to the epithelium of the same airway locations with repeated challenges. Airway size was measured with computed tomography, and closure was considered to occur in any airway where the lumen fell below the resolution of the scanner (< 1 mm. Results Our results show that, while treated airways still have the capacity to close at very high doses of Mch, this ability is seriously impaired after treatment, requiring much higher doses. Conclusions Bronchial thermoplasty as currently applied seems to simply shift the entire dose response curve toward increasing airway size. Thus, this procedure simply serves to minimize the ability of airways to narrow under any level of stimulation.

  13. Effect of Bronchial Thermoplasty on Airway Closure.

    Science.gov (United States)

    Brown, Robert; Wizeman, William; Danek, Christopher; Mitzner, Wayne

    2007-10-12

    BACKGROUND: Bronchial Thermoplasty, a procedure that applies thermal energy to the airway wall has been shown to impair the ability of airway to contract in response to methacholine chloride (Mch). The technique has been advocated as an alternative treatment for asthma that may permanently limit airway narrowing. In previous experimental studies in dogs and humans, it was shown that those airways treated with bronchial thermoplasty had significant impairment of Mch responsiveness. METHODS: In the present study, we investigated the ability of canine airways to close completely with very high concentrations of Mch after bronchial thermoplasty. Bronchial thermoplasty was performed on dogs using the Alair System, comprising a low power RF controller and a basket catheter with four electrodes. A local atomization of Mch agonist was delivered directly to the epithelium of the same airway locations with repeated challenges. Airway size was measured with computed tomography, and closure was considered to occur in any airway where the lumen fell below the resolution of the scanner (Bronchial thermoplasty as currently applied seems to simply shift the entire dose response curve toward increasing airway size. Thus, this procedure simply serves to minimize the ability of airways to narrow under any level of stimulation.

  14. Don’t call it a closure!

    CERN Multimedia

    Rosaria Marraffino

    2015-01-01

    During the Laboratory’s annual closure, some members of the personnel joined their families, others seized the chance to travel the world. The Restaurants were closed, the corridors were dark and the heating was turned off in most of the buildings. However, a lot of people spent the Christmas break working on site and the Bulletin would like to dedicate this first article of the new year to them all!   In the CERN Control Centre (CCC), each shift had two people in position to guarantee regular 24/7 service and to intervene in case of need. Gildas Langlois and Rodolphe Maillet, CCC operators from the Beams Department, spent Christmas Eve there and celebrated it with a cake. “I volunteered to work during the holidays in order to allow colleagues to stay with their families,” says Maillet. On New Year’s Eve, it was Julien Pache and Jean-Michel Nonglaton’s turn to spend the night at work. They had a nice dinner with a CCC-made fondue and some desse...

  15. 300 Area waste acid treatment system closure plan. Revision 1

    International Nuclear Information System (INIS)

    1996-03-01

    This section provides a description of the Hanford Site, identifies the proposed method of 300 Area Waste Acid Treatment System (WATS) closure, and briefly summarizes the contents of each chapter of this plan

  16. 300 Area waste acid treatment system closure plan

    Energy Technology Data Exchange (ETDEWEB)

    LUKE, S.N.

    1999-05-17

    The Hanford Facility Dangerous Waste Permit Application is considered to be a single application organized into a General Information Portion (document number DOERL-91-28) and a Unit-Specific Portion. The scope of the Unit-Specific Portion includes closure plan documentation submitted for individual, treatment, storage, and/or disposal units undergoing closure, such as the 300 Area Waste Acid Treatment System. Documentation contained in the General Information Portion is broader in nature and could be used by multiple treatment, storage, and/or disposal units (e.g., the glossary provided in the General Information Portion). Whenever appropriate, 300 Area Waste Acid Treatment System documentation makes cross-reference to the General Information Portion, rather than duplicating text. This 300 Area Waste Acid Treatment System Closure Plan (Revision 2) includes a Hanford Facility Dangerous Waste Permit Application, Part A, Form 3. Information provided in this closure plan is current as of April 1999.

  17. Economic evaluation of closure cap barrier materials study

    Energy Technology Data Exchange (ETDEWEB)

    Serrato, M.G.; Bhutani, J.S.; Mead, S.M.

    1993-09-01

    Volume II of the Economic Evaluation of the Closure Cap Barrier Materials, Revision I contains detailed cost estimates for closure cap barrier materials. The cost estimates incorporate the life cycle costs for a generic hazardous waste seepage basin closure cap under the RCRA Post Closure Period of thirty years. The economic evaluation assessed six barrier material categories. Each of these categories consists of several composite cover system configurations, which were used to develop individual cost estimates. The information contained in this report is not intended to be used as a cost estimating manual. This information provides the decision makers with the ability to screen barrier materials, cover system configurations, and identify cost-effective materials for further consideration.

  18. Ownership conversion and closure in the nursing home industry.

    Science.gov (United States)

    Bowblis, John R

    2011-06-01

    Ownership conversions and closures in the nursing home literature have largely been treated as separate issues. This paper studies the predictors of nursing home ownership conversions and closure in a common framework after the implementation of the Prospective Payment System in Medicare skilled nursing facilities. The switch in reimbursement regimes impacted facilities with greater exposure to Medicare and lower efficiency. Facilities that faced greater financial difficulty were more likely to be involved in an ownership conversion or closure, but after controlling for other factors the effect of exposure to Medicare is small. Further, factors that predict conversion were found to vary between not-for-profit and for-profit facilities, while factors that predict closure were the same for each ownership type. 2010 John Wiley & Sons, Ltd.

  19. 300 Area waste acid treatment system closure plan

    International Nuclear Information System (INIS)

    LUKE, S.N.

    1999-01-01

    The Hanford Facility Dangerous Waste Permit Application is considered to be a single application organized into a General Information Portion (document number DOERL-91-28) and a Unit-Specific Portion. The scope of the Unit-Specific Portion includes closure plan documentation submitted for individual, treatment, storage, and/or disposal units undergoing closure, such as the 300 Area Waste Acid Treatment System. Documentation contained in the General Information Portion is broader in nature and could be used by multiple treatment, storage, and/or disposal units (e.g., the glossary provided in the General Information Portion). Whenever appropriate, 300 Area Waste Acid Treatment System documentation makes cross-reference to the General Information Portion, rather than duplicating text. This 300 Area Waste Acid Treatment System Closure Plan (Revision 2) includes a Hanford Facility Dangerous Waste Permit Application, Part A, Form 3. Information provided in this closure plan is current as of April 1999

  20. Patent Foramen Ovale Closure or Antiplatelet Therapy for Cryptogenic Stroke

    DEFF Research Database (Denmark)

    Søndergaard, Lars; Kasner, Scott E; Rhodes, John F

    2017-01-01

    BACKGROUND: The efficacy of closure of a patent foramen ovale (PFO) in the prevention of recurrent stroke after cryptogenic stroke is uncertain. We investigated the effect of PFO closure combined with antiplatelet therapy versus antiplatelet therapy alone on the risks of recurrent stroke and new...... incidence of new brain infarction, which was a composite of clinical ischemic stroke or silent brain infarction detected on imaging. RESULTS: We enrolled 664 patients (mean age, 45.2 years), of whom 81% had moderate or large interatrial shunts. During a median follow-up of 3.2 years, clinical ischemic...... stroke occurred in 6 of 441 patients (1.4%) in the PFO closure group and in 12 of 223 patients (5.4%) in the antiplatelet-only group (hazard ratio, 0.23; 95% confidence interval [CI], 0.09 to 0.62; P=0.002). The incidence of new brain infarctions was significantly lower in the PFO closure group than...

  1. Underground storage tank 253-D1U1 Closure Plan

    Energy Technology Data Exchange (ETDEWEB)

    Mancieri, S.; Giuntoli, N.

    1993-09-01

    This report is a closure plan for a diesel fuel tank at the Lawrence Livermore National Laboratory. Included are maps of the site, work plans, and personnel information regarding training and qualification.

  2. Guidance for closure of existing DOE LLW disposal sites

    International Nuclear Information System (INIS)

    Blanchfield, L.

    1987-01-01

    During FY 1986, a closure guidance document was developed. The purpose of this document is to provide guidance in support of DOE Order 5820.2 to site operating contractors for the stabilization and closure of existing low-level waste (LLW) shallow land disposal sites at US Department of Energy (DOE) facilities. Guidance is provided to aid operators in placing existing LLW sites in a closed conditions, i.e., a condition in which a nonoperational site meets postclosure performance requirements and can be shown, within a high degree of confidence, to perform as anticipated in the future, under the most cost-effective maintenance approach. Guidance is based on the philosophy that closure should be planned and performed using a systems approach. Plans for FY 1987 call for revision of the document to incorporate more information on closure of LLW sites also containing radioactive mixed waste and/or transuranic waste. 4 references, 3 figures, 2 tables

  3. IDP camp closure and gender inequality in Timor-Leste

    Directory of Open Access Journals (Sweden)

    Phyllis Ferguson

    2010-02-01

    Full Text Available The goal of humanitarian assistance in Timor-Leste during a seriesof crises from 2006 to 2008 became increasingly focused on IDPcamp closure, with the assisted return of IDPs to their communitiesor to alternative living situations.

  4. Procedures adopted by orthodontists for space closure and anchorage control

    Directory of Open Access Journals (Sweden)

    André da Costa Monini

    2013-12-01

    Full Text Available OBJECTIVE: The aim of this study was to identify the procedures adopted by Brazilian orthodontists in the following situations: extraction space closure, anchorage control in case of necessary anchorage for group A and frequency of skeletal anchorage use, especially in the upper jaw. METHOD: A questionnaire was sent to the e-mail address of all dentists registered in the Brazilian Federal Council of Dentistry. RESULTS: The results showed that most Brazilian orthodontists usually perform extraction space closure by means of sliding mechanics. The use of palatal bar, inclusion of second molars in the archwire and space closure performed in two phases are the most used techniques for anchorage control in the upper jaw. The skeletal anchorage is referenced by 36.5% of specialists as a routine practice for the upper jaw anchorage. CONCLUSIONS: There is a wide variety of procedures adopted by Brazilian orthodontists for orthodontic space closure and anchorage control.

  5. Procedures adopted by orthodontists for space closure and anchorage control.

    Science.gov (United States)

    Monini, André da Costa; Gandini Júnior, Luiz Gonzaga; dos Santos-Pinto, Ary; Maia, Luiz Guilherme Martins; Rodrigues, Willian Caetano

    2013-01-01

    The aim of this study was to identify the procedures adopted by Brazilian orthodontists in the following situations: extraction space closure, anchorage control in case of necessary anchorage for group A and frequency of skeletal anchorage use, especially in the upper jaw. A questionnaire was sent to the e-mail address of all dentists registered in the Brazilian Federal Council of Dentistry. The results showed that most Brazilian orthodontists usually perform extraction space closure by means of sliding mechanics. The use of palatal bar, inclusion of second molars in the archwire and space closure performed in two phases are the most used techniques for anchorage control in the upper jaw. The skeletal anchorage is referenced by 36.5% of specialists as a routine practice for the upper arch anchorage. There is a wide variety of procedures adopted by Brazilian orthodontists for orthodontic space closure and anchorage control.

  6. Stress analysis of closure bolts for shipping casks

    International Nuclear Information System (INIS)

    Mok, G.C.; Fischer, L.E.; Hsu, S.T.

    1993-01-01

    This report specifies the requirements and criteria for stress analysis of closure bolts for shipping casks containing nuclear spent fuels or high level radioactive materials. The specification is based on existing information conceming the structural behavior, analysis, and design of bolted joints. The approach taken was to extend the ASME Boiler and Pressure Vessel Code requirements and criteria for bolting analysis of nuclear piping and pressure vessels to include the appropriate design and load characteristics of the shipping cask. The characteristics considered are large, flat, closure lids with metal-to-metal contact within the bolted joint; significant temperature and impact loads; and possible prying and bending effects. Specific formulas and procedures developed apply to the bolt stress analysis of a circular, flat, bolted closure. The report also includes critical load cases and desirable design practices for the bolted closure, an in-depth review of the structural behavior of bolted joints, and a comprehensive bibliography of current information on bolted joints

  7. 10 CFR 61.28 - Contents of application for closure.

    Science.gov (United States)

    2010-01-01

    ... excavated areas, closure and sealing, waste migration and interaction with emplacement media, or any other... care. (b) An environmental report or a supplement to an environmental report prepared in accordance...

  8. Naturally deducing estimate for the coefficient of celss closure

    Science.gov (United States)

    Bartsev, S. I.

    The term Closed Ecological System (CES) is in wide use. However there is no generally accepted measure of the closure of ecological systems. In order to obtain reproducibility of experiments with natural and man-made CES (with respect to degree of closure) some universal estimate needs to be developed. Understanding ecological systems as a network and closure as the degree of matter recycling allows the use of matrix graphs. Graphs are very natural forms for the presentation of the network of matter flows in ecosystems. An estimate equal to the sum of products of weights of oriented edges that constitute contour is suggested as a measure of the degree of closure in ecosystems. It is shown that this estimate can be uniformly applied to ecosystems of arbitrary size and configuration of flows.

  9. 300 Area waste acid treatment system closure plan. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    This section provides a description of the Hanford Site, identifies the proposed method of 300 Area Waste Acid Treatment System (WATS) closure, and briefly summarizes the contents of each chapter of this plan.

  10. Economic evaluation of closure cap barrier materials study

    International Nuclear Information System (INIS)

    Serrato, M.G.; Bhutani, J.S.; Mead, S.M.

    1993-09-01

    Volume II of the Economic Evaluation of the Closure Cap Barrier Materials, Revision I contains detailed cost estimates for closure cap barrier materials. The cost estimates incorporate the life cycle costs for a generic hazardous waste seepage basin closure cap under the RCRA Post Closure Period of thirty years. The economic evaluation assessed six barrier material categories. Each of these categories consists of several composite cover system configurations, which were used to develop individual cost estimates. The information contained in this report is not intended to be used as a cost estimating manual. This information provides the decision makers with the ability to screen barrier materials, cover system configurations, and identify cost-effective materials for further consideration

  11. CLOSURE REPORT FOR CORRECTIVE ACTION UNIT 214: BUNKERS AND STORAGE AREAS NEVADA TEST SITE, NEVADA

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-09-01

    The purpose of this Closure Report is to document that the closure of CAU 214 complied with the Nevada Division of Environmental Protection-approved Corrective Action Plan closure requirements. The closure activities specified in the Corrective Action Plan were based on the approved corrective action alternatives presented in the CAU 214 Corrective Action Decision Document.

  12. 30 CFR 75.1204 - Mine closure; filing of map with Secretary.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Mine closure; filing of map with Secretary. 75... MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Maps § 75.1204 Mine closure... notify the Secretary of such closure. Within 60 days of the permanent closure or abandonment of the mine...

  13. Pressure disequilibria induced by rapid valve closure in noble gas extraction lines

    Science.gov (United States)

    Morgan, Leah; Davidheiser-Kroll, Brett

    2015-01-01

    Pressure disequilibria during rapid valve closures can affect calculated molar quantities for a range of gas abundance measurements (e.g., K-Ar geochronology, (U-Th)/He geochronology, noble gas cosmogenic chronology). Modeling indicates this effect in a system with a 10 L reservoir reaches a bias of 1% before 1000 pipette aliquants have been removed from the system, and a bias of 10% before 10,000 aliquants. Herein we explore the causes and effects of this problem, which is the result of volume changes during valve closure. We also present a solution in the form of an electropneumatic pressure regulator that can precisely control valve motion. This solution reduces the effect to ∼0.3% even after 10,000 aliquants have been removed from a 10 L reservoir.

  14. Alpha Decay Half-Lives of Exotic Nuclei around Shell Closures

    Science.gov (United States)

    Wang, Y. Z.; Gu, Q. F.; Dong, J. M.; Peng, B. B.

    In the framework of the generalized liquid drop model (GLDM) and improved Royer's formula with a set of new coefficients derived by N. D. Schubert et al. [Eur. Phys. J. A 42 (2009) 121], the favored and unfavored α-decay half-lives of exotic nuclei around closed shells Z = 82 and N = 126 are investigated. The calculated results are in good agreement with the experimental data. It is shown that our method can be used to study the α-decay half-lives of exotic nuclei around shell closures successfully and is helpful for future research on superheavy nuclei around the next proton and neutron shell closures. In addition, some α-decay half-lives for the cases where the experimental values are unavailable are predicted. We hope our predicted results are useful for future experiments.

  15. Student behavior during a school closure caused by pandemic influenza A/H1N1.

    Science.gov (United States)

    Miller, Joel C; Danon, Leon; O'Hagan, Justin J; Goldstein, Edward; Lajous, Martin; Lipsitch, Marc

    2010-05-05

    Many schools were temporarily closed in response to outbreaks of the recently emerged pandemic influenza A/H1N1 virus. The effectiveness of closing schools to reduce transmission depends largely on student/family behavior during the closure. We sought to improve our understanding of these behaviors. To characterize this behavior, we surveyed students in grades 9-12 and parents of students in grades 5-8 about student activities during a week long closure of a school during the first months after the disease emerged. We found significant interaction with the community and other students-though less interaction with other students than during school-with the level of interaction increasing with grade. Our results are useful for the future design of social distancing policies and to improving the ability of modeling studies to accurately predict their impact.

  16. Student behavior during a school closure caused by pandemic influenza A/H1N1.

    Directory of Open Access Journals (Sweden)

    Joel C Miller

    Full Text Available BACKGROUND: Many schools were temporarily closed in response to outbreaks of the recently emerged pandemic influenza A/H1N1 virus. The effectiveness of closing schools to reduce transmission depends largely on student/family behavior during the closure. We sought to improve our understanding of these behaviors. METHODOLOGY/PRINCIPAL FINDINGS: To characterize this behavior, we surveyed students in grades 9-12 and parents of students in grades 5-8 about student activities during a week long closure of a school during the first months after the disease emerged. We found significant interaction with the community and other students-though less interaction with other students than during school-with the level of interaction increasing with grade. CONCLUSIONS: Our results are useful for the future design of social distancing policies and to improving the ability of modeling studies to accurately predict their impact.

  17. Analysis of the correlative factors for velopharyngeal closure of patients with cleft palate after primary repair.

    Science.gov (United States)

    Chen, Qi; Li, Yang; Shi, Bing; Yin, Heng; Zheng, Guang-Ning; Zheng, Qian

    2013-12-01

    The objective of this study was to analyze the correlative factors for velopharyngeal closure of patients with cleft palate after primary repair. Ninety-five nonsyndromic patients with cleft palate were enrolled. Two surgical techniques were applied in the patients: simple palatoplasty and combined palatoplasty with pharyngoplasty. All patients were assessed 6 months after the operation. The postoperative velopharyngeal closure (VPC) rate was compared by χ(2) test and the correlative factors were analyzed with logistic regression model. The postoperative VPC rate of young patients was higher than that of old patients, the group with incomplete cleft palate was higher than the group with complete cleft palate, and combined palatoplasty with pharyngoplasty was higher than simple palatoplasty. Operative age, cleft type, and surgical technique were the contributing factors for postoperative VPC rate. Operative age, cleft type, and surgical technique were significant factors influencing postoperative VPC rate of patients with cleft palate. Copyright © 2013 Elsevier Inc. All rights reserved.

  18. Pressure disequilibria induced by rapid valve closure in noble gas extraction lines

    Science.gov (United States)

    Morgan, Leah E.; Davidheiser-Kroll, Brett

    2015-06-01

    Pressure disequilibria during rapid valve closures can affect calculated molar quantities for a range of gas abundance measurements (e.g., K-Ar geochronology, (U-Th)/He geochronology, noble gas cosmogenic chronology). Modeling indicates this effect in a system with a 10 L reservoir reaches a bias of 1% before 1000 pipette aliquants have been removed from the system, and a bias of 10% before 10,000 aliquants. Herein we explore the causes and effects of this problem, which is the result of volume changes during valve closure. We also present a solution in the form of an electropneumatic pressure regulator that can precisely control valve motion. This solution reduces the effect to ˜0.3% even after 10,000 aliquants have been removed from a 10 L reservoir.

  19. Patent Foramen Ovale Closure or Antiplatelet Therapy for Cryptogenic Stroke.

    Science.gov (United States)

    Søndergaard, Lars; Kasner, Scott E; Rhodes, John F; Andersen, Grethe; Iversen, Helle K; Nielsen-Kudsk, Jens E; Settergren, Magnus; Sjöstrand, Christina; Roine, Risto O; Hildick-Smith, David; Spence, J David; Thomassen, Lars

    2017-09-14

    The efficacy of closure of a patent foramen ovale (PFO) in the prevention of recurrent stroke after cryptogenic stroke is uncertain. We investigated the effect of PFO closure combined with antiplatelet therapy versus antiplatelet therapy alone on the risks of recurrent stroke and new brain infarctions. In this multinational trial involving patients with a PFO who had had a cryptogenic stroke, we randomly assigned patients, in a 2:1 ratio, to undergo PFO closure plus antiplatelet therapy (PFO closure group) or to receive antiplatelet therapy alone (antiplatelet-only group). Imaging of the brain was performed at the baseline screening and at 24 months. The coprimary end points were freedom from clinical evidence of ischemic stroke (reported here as the percentage of patients who had a recurrence of stroke) through at least 24 months after randomization and the 24-month incidence of new brain infarction, which was a composite of clinical ischemic stroke or silent brain infarction detected on imaging. We enrolled 664 patients (mean age, 45.2 years), of whom 81% had moderate or large interatrial shunts. During a median follow-up of 3.2 years, clinical ischemic stroke occurred in 6 of 441 patients (1.4%) in the PFO closure group and in 12 of 223 patients (5.4%) in the antiplatelet-only group (hazard ratio, 0.23; 95% confidence interval [CI], 0.09 to 0.62; P=0.002). The incidence of new brain infarctions was significantly lower in the PFO closure group than in the antiplatelet-only group (22 patients [5.7%] vs. 20 patients [11.3%]; relative risk, 0.51; 95% CI, 0.29 to 0.91; P=0.04), but the incidence of silent brain infarction did not differ significantly between the study groups (P=0.97). Serious adverse events occurred in 23.1% of the patients in the PFO closure group and in 27.8% of the patients in the antiplatelet-only group (P=0.22). Serious device-related adverse events occurred in 6 patients (1.4%) in the PFO closure group, and atrial fibrillation occurred in 29

  20. Monte Carlo closure for moment-based transport schemes in general relativistic radiation hydrodynamic simulations

    Science.gov (United States)

    Foucart, Francois

    2018-04-01

    General relativistic radiation hydrodynamic simulations are necessary to accurately model a number of astrophysical systems involving black holes and neutron stars. Photon transport plays a crucial role in radiatively dominated accretion discs, while neutrino transport is critical to core-collapse supernovae and to the modelling of electromagnetic transients and nucleosynthesis in neutron star mergers. However, evolving the full Boltzmann equations of radiative transport is extremely expensive. Here, we describe the implementation in the general relativistic SPEC code of a cheaper radiation hydrodynamic method that theoretically converges to a solution of Boltzmann's equation in the limit of infinite numerical resources. The algorithm is based on a grey two-moment scheme, in which we evolve the energy density and momentum density of the radiation. Two-moment schemes require a closure that fills in missing information about the energy spectrum and higher order moments of the radiation. Instead of the approximate analytical closure currently used in core-collapse and merger simulations, we complement the two-moment scheme with a low-accuracy Monte Carlo evolution. The Monte Carlo results can provide any or all of the missing information in the evolution of the moments, as desired by the user. As a first test of our methods, we study a set of idealized problems demonstrating that our algorithm performs significantly better than existing analytical closures. We also discuss the current limitations of our method, in particular open questions regarding the stability of the fully coupled scheme.

  1. A "typodont" study of rate of orthodontic space closure: self-ligating systems vs. conventional systems.

    Science.gov (United States)

    Saporito, I; Butti, A C; Salvato, A; Biagi, R

    2011-01-01

    The aim of this study was to compare the effectiveness of space closure of two bracket systems, self-ligating and conventional ones, considering two systems with the same design and prescription. The experimental model of this study aims to identify in general if one type of system is more suitable for planning the extractive therapy, without considering the clinical aspect necessary for an adequate orthodontic approach. A resin maxilla without the first premolars was used to test the self-ligating and conventional brackets system. Space closure was achieved on 0.016x0.022" in stainless steel wires with nickel-titanium coil springs 150 grams in strength and 10 mm in length. Two experiment settings have been prepared. The first setting was made bonding conventional bracket on the right side and self-ligating on the left; the last one was made bonding self-ligating bracket on the right side and conventional on the left. All measurements (runs) have been repeated seven times for both settings. During the closing phase of extraction spaces both systems are equable since there are no significant statistical differences (P=0.70). Our typodont model showed no significant difference in the efficiency of space closure between the self-ligating bracket and conventional bracket tied with stainless steel ligatures.

  2. DYNAMIC ANALYSIS OF THE BULK TRITIUM SHIPPING PACKAGE SUBJECTED TO CLOSURE TORQUES AND SEQUENTIAL IMPACTS

    International Nuclear Information System (INIS)

    Wu, T; Paul Blanton, P; Kurt Eberl, K

    2007-01-01

    This paper presents a finite-element technique to simulate the structural responses and to evaluate the cumulative damage of a radioactive material packaging requiring bolt closure-tightening torque and subjected to the scenarios of the Hypothetical Accident Conditions (HAC) defined in the Code of Federal Regulations Title 10 part 71 (10CFR71). Existing finite-element methods for modeling closure stresses from bolt pre-load are not readily adaptable to dynamic analyses. The HAC events are required to occur sequentially per 10CFR71 and thus the evaluation of the cumulative damage is desirable. Generally, each HAC event is analyzed separately and the cumulative damage is partially addressed by superposition. This results in relying on additional physical testing to comply with 10CFR71 requirements for assessment of cumulative damage. The proposed technique utilizes the combination of kinematic constraints, rigid-body motions and structural deformations to overcome some of the difficulties encountered in modeling the effect of cumulative damage. This methodology provides improved numerical solutions in compliance with the 10CFR71 requirements for sequential HAC tests. Analyses were performed for the Bulk Tritium Shipping Package (BTSP) designed by Savannah River National Laboratory to demonstrate the applications of the technique. The methodology proposed simulates the closure bolt torque preload followed by the sequential HAC events, the 30-foot drop and the 30-foot dynamic crush. The analytical results will be compared to the package test data

  3. Design Alternative Evaluation No. 3: Post-Closure Ventilation

    International Nuclear Information System (INIS)

    Logan, R.C.

    1999-01-01

    The objective of this study is to provide input to the Enhanced Design Alternatives (EDA) for License Application Design Selection (LADS). Its purpose is to develop and evaluate conceptual designs for post-closure ventilation alternatives that enhance repository performance. Post-closure ventilation is expected to enhance repository performance by limiting the amount of water contacting the waste packages. Limiting the amount of water contacting the waste packages will reduce corrosion

  4. Environmental aspects of hard coal mines closure in Poland

    International Nuclear Information System (INIS)

    Chaber, M.; Krogulski, K.; Gawlik, L.

    1998-01-01

    The environmental problems that arise during the closure processes of hard coal mines in Poland are undertaken in the paper. The problems of changes in water balance in rock mass are described with a stress put on underground water management. Regulation concerning ground reclamation and utilisation and removal of existing heat and power plants which after the mines closure will continue to supply surrounding consumers are stressed and the possible solutions are shown. 13 refs

  5. Shell closure in stable and unstable Fermion systems

    International Nuclear Information System (INIS)

    Lombard, R.J.

    1991-01-01

    Some of the findings of calculations performed with the density functional method in connection with shell closure are presented. In nuclei, some evidences seam to confirm the existence of a shell closure at N or Z=16, for Z or N<11. More data, particularly spectroscopic measurements would provide further information. Single particle energies for Z=16 isotopes as function of the neutron number N are given. (G.P.) 9 refs.; 6 figs

  6. Synthesis of Pyridoacridines through Anionic Cascade Ring Closure

    DEFF Research Database (Denmark)

    Petersen, I.N.; Kristensen, Jesper Langgaard

    2014-01-01

    A new synthesis of 13-deazaascididemin (AK-37) based on a recently developed anionic cascade ring closure is presented. Although the isolated yields are modest, the approach provides ready access to new substituted derivatives of 13-deazaascididemin.......A new synthesis of 13-deazaascididemin (AK-37) based on a recently developed anionic cascade ring closure is presented. Although the isolated yields are modest, the approach provides ready access to new substituted derivatives of 13-deazaascididemin....

  7. A NOTE ON FUZZY CLOSURE OF A FUZZY SET

    Directory of Open Access Journals (Sweden)

    Bhimraj Basumatary

    2015-10-01

    Full Text Available In this article fuzzy closure has been discussed with the help of extended definition of fuzzy set on the assumption that the union of a fuzzy set and its complement is universal set and intersection of a fuzzy set and its complement is empty set. Also we have discussed some proposition of fuzzy closure with the help of numerical example on the basis of extended definition of fuzzy set.

  8. The reading man flap for closure of large meningomyelocele defects.

    Science.gov (United States)

    Mutaf, Mehmet; Temel, Metin; Günal, Ertan

    2012-05-01

    Closure of the skin defect in myelomeningocele repair is an essential step that determines the quality of the surgical result. In large myelomeningoceles, however, adequate skin coverage may not be accomplished by direct closure or skin undermining. In such cases, the skin defect is best repaired using flaps. The aim of this study is to evaluate the reading man procedure for closure of large meningomyelocele defect. In this procedure, after neurosurgical repair and closure of the placode, the defect surgically becomes a circle in shape. Then, the circular defect is closed by transposition of two skin flaps designed in an unequal Z-plasty manner. Over 5 years, the reading man procedure was used for closure of large meningomyelocele defects in seven patients (four females and three males), aged between 1.5 and 6 months. The defect size was 10.5×7.25 cm (8.5×5.3 and 12.6×9.5 cm) on average. The localisation of the lesions was thoracolumbar in two patients and lumbosacral in five patients. In all patients, a successful tension-free one-stage closure was obtained without dog-ear formation. Except for one patient with minimal tip necrosis, healing was uneventful without any complications. There was no patient with late breakdown of the wound during 1.5 years (8 months-4 years) of mean follow-up. The reading man procedure enables the surgeon to achieve a tension-free defect closure of considerably large meningomyeleocele defects. Using two well-vascularised fasciocutaneous flaps, it provides a durable coverage and soft tissue padding over the neural tissues with no suture seam at midline. With these advantages, the Reading Man Procedure seems to be a useful and safe alternative for closure of large meningomyelocele defects. Copyright © 2011 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  9. Multipass mining sequence room closures: In situ data report

    International Nuclear Information System (INIS)

    Munson, D.E.; Jones, R.L.; Northrop-Salazar, C.L.; Woerner, S.J.

    1992-12-01

    During the construction of the Thermal/Structural In Situ Test Rooms at the Waste Isolation Pilot Plant (WIPP) facility, measurements of the salt displacements were obtained at very early times, essentially concurrent with the mining activity. This was accomplished by emplacing manually read closure gage stations directly at the mining face, actually between the face and the mining machine, immediately upon mining of the intended gage location. Typically, these mining sequence closure measurements were taken within one hour of mining of the location and within one meter of the mining face. Readings were taken at these gage stations as the multipass mining continued, with the gage station reestablished as each successive mining pass destroyed the earlier gage points. Data reduction yields the displacement history during the mining operation. These early mining sequence closure data, when combined with the later data of the permanently emplaced closure gages, gives the total time-dependent closure displacements of the test rooms. This complete closure history is an essential part of assuring that the in situ test databases will provide an adequate basis for validation of the predictive technology of salt creep behavior, as required by the WIPP technology development program for disposal of radioactive waste in bedded salt

  10. Potential socio-economic consequences of mine closure

    Directory of Open Access Journals (Sweden)

    Marietjie Ackermann

    2018-01-01

    Full Text Available Background: Mine closures generally reveal negligence on the part of mining houses, not only in terms of the environment, but also the surrounding mining communities. Aim: This article reflects on the findings of research into the socio-economic consequences of mine closure. The research specifically explored how mineworkers’ dependency on their employment at a mine affects their ability to sustain their livelihood. Setting: The research was conducted at the Orkney Mine and the Grootvlei Mine (Springs. Methods: The research was conducted within a naturalistic domain, guided by a relativist orientation, a constructivist ontology and an interpretivist epistemology. Data were collected by means of document analysis, semi-structured interviews, focus group discussion and unstructured observation. Results: From the research findings, it is evident that mine closures, in general, have a devastating effect on the surrounding mining communities as well as on the employees. Mine closures in the case studies gradually depleted the mining communities’ livelihood assets and resulted in the collapse of their coping strategies and livelihood outcomes. It generally affected the communities’ nutrition, health, education, food security, water, shelter, levels of community participation and personal safety. Conclusion: If not managed efficiently and effectively, mine closures may pose significant challenges to the mining industry, government, the environment, national and local economic prosperity and communities in the peripheral areas of mines. This truly amplifies that mine closure, whether temporary or permanent, is an issue that needs to be addressed with responsibility towards all stakeholders, including the mining community and the labour force.

  11. CLOSURE REPORT FOR CORRECTIVE ACTION UNIT 528: POLYCHLORINATED BIPHENYLS CONTAMINATION NEVADA TEST SITE, NEVADA

    Energy Technology Data Exchange (ETDEWEB)

    BECHTEL NEVADA

    2006-09-01

    This Closure Report (CR) describes the closure activities performed at CAU 528, Polychlorinated Biphenyls Contamination, as presented in the Nevada Division of Environmental Protection (NDEP)-approved Corrective Action Plan (CAP) (US. Department of Energy, National Nuclear Security Administration Nevada Site Office [NNSAINSO], 2005). The approved closure alternative was closure in place with administrative controls. This CR provides a summary of the completed closure activities, documentation of waste disposal, and analytical data to confirm that the remediation goals were met.

  12. The Gore-Tex Suture in Periareolar Closure: A Modified Closure Technique.

    Science.gov (United States)

    Chapman, Jade; Ingram, Scott

    2016-12-01

    In breast reduction and mastopexy procedures, the periareolar closure forms a vital component of the surgery. Periareolar closures completed with an absorbable suture may be prone to significant widening, hypertrophy and/or areolar distortion. In an effort to avoid this, some surgeons use a non-absorbable/permanent suture material [Franco (Arch Plast Surg 41 (6): 728-733, 2014)]. Hammond (Plast Reconstr Surg 119 (3):804-809, 2007) recommends the use of a Gore-Tex® suture for this purpose in view of the supple, pliable nature of the material; however, there remain at least occasional instances of infection and extrusion of the knot used to tie off the Gore-Tex "purse-string" [Franco (Arch Plast Surg 41 (6): 728-733, 2014); Salgarello (Aesthet Plast Surg 37 (5):1061-1062, 2013)]. We describe a method of securing the suture ends, which avoids the creation of a bulky knot, thus minimising the risk of infection and suture extrusion. Level of Evidence V This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

  13. Phacoemulsification treatment of subjects with acute primary angle closure and chronic primary angle-closure glaucoma.

    Science.gov (United States)

    Zhuo, Ye-Hong; Wang, Mei; Li, Ying; Hao, Yuan-Tao; Lin, Min-Kai; Fang, Min; Ge, Jian

    2009-12-01

    To investigate and compare the effects of phacoemulsification as an initial procedure to control intraocular pressure (IOP) in eyes with acute primary angle closure (APAC) and chronic primary angle-closure glaucoma (CPACG) with coexisting cataracts and peripheral anterior synechiae (PAS) of greater than 180 degrees. Prospective, cross-sectional study. Thirteen patients (13 eyes) with APAC and 10 patients (10 eyes) with CPACG were enrolled in the study. IOP control in the 2 groups was compared at final follow-up. Other outcome measures included visual acuity, anterior chamber depth, gonioscopic appearance, and complications. The postoperative IOP was reduced in both the APAC and CPACG groups. As assessed at last follow-up (median 6 mo), IOP in the APAC group was significantly lower than that in the CPACG group. The absolute success rate was 100% in the APAC group and 80% in the CPACG group. The number of hypotensive medications decreased in both APAC and CPACG group. The postoperative degree of PAS was relieved in 11 of 12 eyes with APAC and 5 of 9 eyes with CPACG. Initial phacoemulsification performed to provide short-term control of IOP is more efficacious in patients with APAC than in those with CPACG, especially when PAS is greater than 180 degrees.

  14. 216-B-3 expansion ponds closure plan

    Energy Technology Data Exchange (ETDEWEB)

    1994-10-01

    This document describes the activities for clean closure under the Resource Conservation and Recovery Act of 1976 (RCRA) of the 216-B-3 Expansion Ponds. The 216-B-3 Expansion Ponds are operated by the US Department of Energy, Richland Operations Office (DOE-RL) and co-operated by Westinghouse Hanford Company (Westinghouse Hanford). The 216-B-3 Expansion Ponds consists of a series of three earthen, unlined, interconnected ponds that receive waste water from various 200 East Area operating facilities. The 3A, 3B, and 3C ponds are referred to as Expansion Ponds because they expanded the capability of the B Pond System. Waste water (primarily cooling water, steam condensate, and sanitary water) from various 200 East Area facilities is discharged to the Bypass pipe (Project X-009). Water discharged to the Bypass pipe flows directly into the 216-B-3C Pond. The ponds were operated in a cascade mode, where the Main Pond overflowed into the 3A Pond and the 3A Pond overflowed into the 3C Pond. The 3B Pond has not received waste water since May 1985; however, when in operation, the 3B Pond received overflow from the 3A Pond. In the past, waste water discharges to the Expansion Ponds had the potential to have contained mixed waste (radioactive waste and dangerous waste). The radioactive portion of mixed waste has been interpreted by the US Department of Energy (DOE) to be regulated under the Atomic Energy Act of 1954; the dangerous waste portion of mixed waste is regulated under RCRA.

  15. The impact of operational closure and reflection on juncture systems

    Directory of Open Access Journals (Sweden)

    Benjamin Kuch

    2016-11-01

    Full Text Available Business organisations can be seen as social systems encompassing multiple scales. The more functionally differentiated a system landscape becomes the higher the need to coordinate different processes between these systems is. This helps to develop sound business strategies supporting the identification of synergy potentials. Induced by turbulent markets, especially multinational enterprises have to continuously adapt their strategies and introduce new junctures between parts of their organisations. The current article contributes to the effective management of those junctures whilst adopting a systems theory perspective. Novel insights on the coordination of strategic change processes, which are most relevant to businesses in order to implement new strategies, are derived from a system dynamics model. They are subsequently applied to a single case study in the medical device industry for the purpose of discussing implications for international enterprises. It is shown how the concepts of operational closure and reflection impact on the junctures between complex social systems. Therefore, it is argued that the analysis of the systemic communication patterns should be considered an integral part of any strategic change process within multinational enterprises. Moreover, the findings are generic enough to be transferred to the regional level as well. The presented approach on the coordination of complex social systems provides valuable impulses, even if the involved systems come from the political or scientific sector. Hence, the investigation of mixed systems coordination is suggested to be part of a future research agenda.

  16. Field-scale water balance closure in seasonally frozen conditions

    Directory of Open Access Journals (Sweden)

    X. Pan

    2017-11-01

    Full Text Available Hydrological water balance closure is a simple concept, yet in practice it is uncommon to measure every significant term independently in the field. Here we demonstrate the degree to which the field-scale water balance can be closed using only routine field observations in a seasonally frozen prairie pasture field site in Saskatchewan, Canada. Arrays of snow and soil moisture measurements were combined with a precipitation gauge and flux tower evapotranspiration estimates. We consider three hydrologically distinct periods: the snow accumulation period over the winter, the snowmelt period in spring, and the summer growing season. In each period, we attempt to quantify the residual between net precipitation (precipitation minus evaporation and the change in field-scale storage (snow and soil moisture, while accounting for measurement uncertainties. When the residual is negligible, a simple 1-D water balance with no net drainage is adequate. When the residual is non-negligible, we must find additional processes to explain the result. We identify the hydrological fluxes which confound the 1-D water balance assumptions during different periods of the year, notably blowing snow and frozen soil moisture redistribution during the snow accumulation period, and snowmelt runoff and soil drainage during the melt period. Challenges associated with quantifying these processes, as well as uncertainties in the measurable quantities, caution against the common use of water balance residuals to estimate fluxes and constrain models in such a complex environment.

  17. Increased patient delays in care after the closure of Martin Luther King Hospital: implications for monitoring health system changes.

    Science.gov (United States)

    Walker, Kara Odom; Leng, Mei; Liang, Li-Jung; Forge, Nell; Morales, Leo; Jones, Loretta; Brown, Arleen

    2011-01-01

    The safety net system remains an important part of the health care system for uninsured and minority populations, however, the closure of safety net hospitals changes the availability of care. Using community-based participatory research methods, we explored the impact of hospital closure among late middle aged and elderly racial/ethnic minorities in South Los Angeles. Telephone survey of participants in both 2008, after hospital closure, and 2003, before hospital closure, who self-identified as African American or Latino, were over the age of 50 and lived in zip codes of South Los Angeles. We developed multiple logistic regression models on imputed data sets weighted for non-response and adjusted for self-reported measures of demographic and clinical characteristics to examine the odds of reporting delays in care. After adjusting for covariates known to influence access to care and distributed differently in the two survey samples, we found significantly greater delays in care. Following the closure of the Martin Luther King, Jr. safety net hospital, the adjusted odds ratios were 1.70 (95% CI 1.01, 2.87) for delays in care, 1.88 (95% Cl 1.06, 3.13) for problems receiving needed medical care, and 2.62 (95% CI 1.46, 4.67) for seeing a specialist. Our survey of older minority adults in South Los Angeles found increased delays in access to care for needed medical services after the closure of Martin Luther King, Jr. Hospital. As health care reform unfolds, monitoring for changes in access to care that may result from new policies will be important to address future disparities, particularly for vulnerable populations.

  18. Nickel titanium springs versus stainless steel springs: A randomized clinical trial of two methods of space closure.

    Science.gov (United States)

    Norman, Noraina Hafizan; Worthington, Helen; Chadwick, Stephen Mark

    2016-09-01

    To compare the clinical performance of nickel titanium (NiTi) versus stainless steel (SS) springs during orthodontic space closure. Two-centre parallel group randomized clinical trial. Orthodontic Department University of Manchester Dental Hospital and Orthodontic Department Countess of Chester Hospital, United Kingdom. Forty orthodontic patients requiring fixed appliance treatment were enrolled, each being randomly allocated into either NiTi (n = 19) or SS groups (n = 21). Study models were constructed at the start of the space closure phase (T0) and following the completion of space closure (T1). The rate of space closure achieved for each patient was calculated by taking an average measurement from the tip of the canine to the mesiobuccal groove on the first permanent molar of each quadrant. The study was terminated early due to time constraints. Only 30 patients completed, 15 in each study group. There was no statistically significant difference between the amounts of space closed (mean difference 0.17 mm (95%CI -0.99 to 1.34; P = 0.76)). The mean rate of space closure for NiTi coil springs was 0.58 mm/4 weeks (SD 0.24) and 0.85 mm/4 weeks (SD 0.36) for the stainless steel springs. There was a statistically significant difference between the two groups (P = 0.024), in favour of the stainless steel springs, when the mean values per patient were compared. Our study shows that stainless steel springs are clinically effective; these springs produce as much space closure as their more expensive rivals, the NiTi springs.

  19. The role of remote closure in the perception of occlusion at junctions and illusory contours.

    Science.gov (United States)

    Gillam, Barbara J; Grove, Philip M; Layden, Jessica

    2010-01-01

    Abstract. Perceived occlusion at T-junctions or illusory contours at implicit T-junctions are often modelled by using edge information without surface context. We explored the effect of closure on perceived occlusion at T-junctions. Two vertical lines separated by a gap each had six abutting horizontal lines on opposite sides forming T-junctions. These lines were either closed or not closed into pairs at the stem ends of the Ts. In experiment 1, closed T-junction stems gave a much stronger sense of occlusion at the vertical lines than unclosed ones, even though closure information was remote from the putative occlusion and local T-junction information remained constant. When the outer two T-junctions were converted to L-junctions, perceived occlusion considerably diminished. The effect of closure on illusory-contour strength for stimuli like those of experiment 1 but with the vertical lines omitted was explored in experiment 2. The two sets of horizontal lines, separated by a gap, were either closed or not closed into pairs at their outer ends. Illusory-contour strength along the vertical alignments was much greater for closed pairs. Line terminations on both sides of the gap enhanced illusory-contour strength, but whether they were collinear or not had little effect.

  20. Argon laser iridoplasty : A primary mode of therapy in primary angle closure glaucoma

    Directory of Open Access Journals (Sweden)

    Agarwal H

    1991-01-01

    Full Text Available Argon laser iridoplasty was performed in 40 eyes of 33 patients of primary angle closure glaucoma. There were 12 male and 21 female patients. The mean ages of the male and female patients were 51 years and 48.4 years respectively. Forty eyes were divided into two groups. Group I consisted of ten eyes of subacute angle closure glaucoma and group II included thirty eyes of chronic angle closure glaucoma. Argon laser iridoplasty was performed with Coherent 9000 model using laser settings of spot size 200 micron, duration 0.2 second and power 0.7 watt. A total of 80 spots were applied over 360 degree circumference. The intraocular pressure control (below 22 mm Hg was achieved after iridoplasty in all the eyes (100% in group I, where as in group II the intraocular pressure was controlled in 70% eyes. The follow up period varied from 3 months to one year with a mean of eight months. The success rate with iridoplasty was directly related to the extent of peripheral anterior synechiae, optic disc cupping and presence of visual field changes.

  1. Extreme precipitation and beach closures in the great lakes region: evaluating risk among the elderly.

    Science.gov (United States)

    Bush, Kathleen F; Fossani, Cheryl L; Li, Shi; Mukherjee, Bhramar; Gronlund, Carina J; O'Neill, Marie S

    2014-02-14

    As a result of climate change, extreme precipitation events are expected to increase in frequency and intensity. Runoff from these extreme events poses threats to water quality and human health. We investigated the impact of extreme precipitation and beach closings on the risk of gastrointestinal illness (GI)-related hospital admissions among individuals 65 and older in 12 Great Lakes cities from 2000 to 2006. Poisson regression models were fit in each city, controlling for temperature and long-term time trends. City-specific estimates were combined to form an overall regional risk estimate. Approximately 40,000 GI-related hospital admissions and over 100 beach closure days were recorded from May through September during the study period. Extreme precipitation (≥90th percentile) occurring the previous day (lag 1) is significantly associated with beach closures in 8 of the 12 cities (p < 0.05). However, no association was observed between beach closures and GI-related hospital admissions. These results support previous work linking extreme precipitation to compromised recreational water quality.

  2. Role of plasticity-induced crack closure in fatigue crack growth

    Directory of Open Access Journals (Sweden)

    Jesús Toribio

    2013-07-01

    Full Text Available The premature contact of crack surfaces attributable to the near-tip plastic deformations under cyclic loading, which is commonly referred to as plasticity induced crack closure (PICC, has long been focused as supposedly controlling factor of fatigue crack growth (FCG. Nevertheless, when the plane-strain near-tip constraint is approached, PICC lacks of straightforward evidence, so that its significance in FCG, and even the very existence, remain debatable. To add insights into this matter, large-deformation elastoplastic simulations of plane-strain crack under constant amplitude load cycling at different load ranges and ratios, as well as with an overload, have been performed. Modeling visualizes the Laird-Smith conceptual mechanism of FCG by plastic blunting and re-sharpening. Simulation reproduces the experimental trends of FCG concerning the roles of stress intensity factor range and overload, but PICC has never been detected. Near-tip deformation patterns discard the filling-in a crack with material stretched out of the crack plane in the wake behind the tip as supposed PICC origin. Despite the absence of closure, load-deformation curves appear bent, which raises doubts about the trustworthiness of closure assessment from the compliance variation. This demonstrates ambiguities of PICC as a supposedly intrinsic factor of FCG and, by implication, favors the stresses and strains in front of the crack tip as genuine fatigue drivers.

  3. Optimum cystic duct closure: a comparative study using metallic clips, ENSEAL, and ENDOLOOP in swine.

    Science.gov (United States)

    McVay, Derek; Nelson, Daniel; Porta, Christopher R; Blair, Kelly; Martin, Matthew

    2013-05-01

    Metal clips are commonly used to secure the cystic duct during cholecystectomy, although use of an ENDOLOOP (Ethicon Endo-Surgery, Blue Ash, OH) is often touted as a more secure closure when postoperative endoscopic retrograde cholangiopancreatography (ERCP) is anticipated. The objective of this study was to test the strength of 3 different cystic duct closure methods in a model simulating postoperative biliary insufflation. The extrahepatic biliary system, including common bile duct, gallbladder, and cystic duct, was harvested en bloc from 22 swine postmortem. A cholecystectomy was performed and the cystic duct was secured using 1 of 3 randomly assigned methods: metallic clips (Ethicon Endo-Surgery), an ENDOLOOP (Ethicon Endo-Surgery), or an ENSEAL tissue sealing device (Ethicon Endo-Surgery). The common bile duct was cannulated with a pressure-monitoring system and insufflated with air. The burst pressures, location of rupture, and size of the common bile duct and cystic duct were recorded and compared. There were 7 pigs each in the ENDOLOOP and ENSEAL groups and 8 in the metallic clip group, with no statistical significance between cystic and common bile duct size. Mean burst pressure was 432 mm Hg for metallic clips, 371 mm Hg for the ENDOLOOP, and 238 mm Hg for the ENSEAL device (P = .02). Post hoc analysis revealed clips to be statistically superior when compared with the ENSEAL (P= .01). There was no statistical difference between the ENDOLOOP and metal clips or between the ENDOLOOP and the ENSEAL. All 3 closure methods successfully secured the cystic duct, with mean burst pressures exceeding 195 mm Hg. Metallic clips demonstrated the highest burst pressures and no cystic duct stump leaks. This study challenges the traditional dogma of additionally securing the cystic duct with an ENDOLOOP when postoperative biliary instrumentation is expected and also suggests that an adequately secure closure may be obtained with thermal sealing devices. Published by

  4. Mitigation of social and environmental impacts resulting from final closure of uranium mines

    International Nuclear Information System (INIS)

    Cipriani, Moacir

    2002-11-01

    This thesis focus on the impact of uranium mines in Brazil. It is recent, in the order of the Brazilian mining, the concern with the impact of mining activities. The Federal Constitution of 1988 compels the miner to rehabilitate the degraded environment, in accordance with the technical solution demanded by the competent public agency, which makes use of a system of environmental norms conditioning the mining activity. However, the concern with the closure of mines is in an early stage, for whose achievement the public power still lacks of norms and regulations. The closure of the first uranium mining in Brazil assumes special meaning, because the possible environmental problems related to uranium mines are considered to be serious and the uranium industry is state owned. This thesis is divided in two sections. The first one describes the state of the art of the uranium industry and the rules and management practices regarding the final closure of uranium mining in Brazil and countries like Australia, Canada, USA and France, that have been selected on the basis of the following criteria: production, exportation, control of reserves and final consumption of uranium. In the second part, a case study of Pocos de Caldas mine is presented, with description of historical production, plant waste and the chemical treatment of the ore. This part also presents the research carried out since the beginning of the operations aiming to remedial actions, including the dismantling of surface structures, tailings reclamation, and ground-water restoration, following CNEN (Brazilian Nuclear Energy Commission) rules, as well as a survey of local press coverage of the impact of the industry. A final recommendation is made regarding a management model and strategies to mitigate social and environmental impacts resulting from final closure of the CIPC. (author)

  5. Association between school closure and subsequent absenteeism during a seasonal influenza epidemic.

    Science.gov (United States)

    Rodriguez, Carla V; Rietberg, Krista; Baer, Atar; Kwan-Gett, Tao; Duchin, Jeffrey

    2009-11-01

    Mathematical models suggest that social distancing measures, such as school closures, may mitigate community transmission during an influenza pandemic. Because closures are disruptive to schools and families, they are rarely employed during seasonal influenza outbreaks. A rare circumstance enabled us to examine the association between school closure and absenteeism during a seasonal influenza outbreak when half of King County, Washington public schools closed for a winter recess 19-23 February 2007, while half remained open for all or part of the week. Using absenteeism as a proxy for influenza activity, we tested the hypothesis that schools on break would experience lower rates of post-break absenteeism than schools remaining open. We conducted daily retrospective and prospective surveillance from 5 February-9 March 2007 in schools on break (n = 256) and in session (n = 205). We use generalized estimating equations with Poisson distribution to evaluate whether mean absenteeism after the break differed between schools on break and those in session, adjusting for baseline absenteeism and repeated measurements by schools over time. Results indicate no difference in post-break absenteeism in schools on break compared with schools that remained in session (relative risk = 1.07 [95% confidence interval = 0.96-1.20]). This result held in elementary schools (1.00 [0.91-1.10]), where absenteeism patterns are thought to be most representative of community influenza activity. We did not find that school closure during a seasonal influenza outbreak reduced subsequent absenteeism. However, limitations in this "natural experiment" hampered our ability to detect a benefit if one truly was present.

  6. Environmental analysis of closure options for waste sites at the Savannah River Plant

    International Nuclear Information System (INIS)

    Gordon, D.E.; King, C.M.; Looney, B.B.; Stephenson, D.E.; Johnson, W.F.

    1987-01-01

    Previously acceptable waste management practices (e.g., the use of unlined seepage basins) for discarding of wastes from nuclear materials production has resulted in occasional cases of groundwater contamination beneath some disposal sites, mainly in water-table aquifers. Groundwater contaminants include volatile organic compounds, heavy metals, radionuclides, and other chemicals. The closure of active and inactive waste sites that have received hazardous and/or low-level radioactive materials at the Savannah River Plant (SRP) is planned as part of an overall program to protect groundwater quality. DOE developed and submitted to Congress a groundwater protection plan for SRP. This initial plan and subsequent revisions provide the basis for closure of SRP waste sites to comply with applicable groundwater protection requirements. An environmental analysis of the closure options for the criteria waste sites that have received hazardous and/or low-level radioactive wastes was conducted to provide technical support. The several parts of this environmental analysis include description of geohydrologic conditions; determination of waste inventories; definition of closure options; modeling of environmental pathways; assessment of risk; and analysis of project costs. Each of these components of the overall analysis is described in turn in the following paragraphs. Production operations at SRP have generated a variety of solid, hazardous, and low-level radioactive waste materials. Several locations onplant have been used as waste disposal sites for solid and liquid wastes. Seventy-six individual waste sites at 45 distinct geographical locations on SRP have received hazardous, low-level radioactive, or mixed wastes. These waste sites can be categorized into 26 groupings according to the function of the waste disposed. 15 refs., 6 figs., 5 tabs

  7. Single-shell tank closure work plan. Revision A

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-06-01

    In January 1994, the Hanford Federal Facility Agreement and Conset Order (Tri-Party Agreement) was amended to reflect a revised strategy for remediation of radioactive waste in underground storage tanks. These amendments include milestones for closure of the single-shell tank (SST) operable units, to be initiated by March 2012 and completed by September 2024. This SST-CWP has been prepared to address the principal topical areas identified in Tri-Party Agreement Milestone M-45-06 (i.e., regulatory pathway, operable unit characterization, waste retrieval, technology development, and a strategy for achieving closure). Chapter 2.0 of this SST-CWP provides a brief description of the environmental setting, SST System, the origin and characteristics of SST waste, and ancillary equipment that will be remediated as part of SST operable unit closure. Appendix 2A provides a description of the hydrogeology of the Hanford Site, including information on the unsaturated sediments (vadose zone) beneath the 200 Areas Plateau. Chapter 3.0 provides a discussion of the laws and regulations applicable to closure of the SST farm operable units. Chapter 4.0 provides a summary description of the ongoing characterization activities that best align with the proposed regulatory pathway for closure. Chapter 5.0 describes aspects of the SST waste retrieval program, including retrieval strategy, technology, and sequence, potential tank leakage during retrieval, and considerations of deployment of subsurface barriers. Chapter 6.0 outlines a proposed strategy for closure. Chapter 7.0 provides a summary of the programs underway or planned to develop technologies to support closure. Ca. 325 refs.

  8. Association of iris crypts with acute primary angle closure.

    Science.gov (United States)

    Koh, Victor; Chua, Jacqueline; Shi, Yuan; Thakku, Sri Gowtham; Lee, Ryan; Nongpiur, Monisha E; Baskaran, Mani; Kumar, Rajesh S; Perera, Shamira; Aung, Tin; Cheng, Ching-Yu

    2017-10-01

    To determine the relationship between iris surface features and acute primary angle closure (APAC) in eyes with angle closure. Case-control study involving Asian patients diagnosed with previous APAC, primary angle closure suspect (PACS), primary angle closure (PAC) and primary angle closure glaucoma (PACG) at an eye centre in Singapore between August 2012 and January 2015. Participants underwent ophthalmic examination and digital slit-lamp iris photography. Iris surface features were graded based on crypts, furrows and colour. Fellow eyes of APAC were compared with PACS and PAC/PACG eyes with regard to their iris surface features. Occurrence of APAC. A total of 309 patients (71 APAC, 139 PACS, 47 PAC and 52 PACG) were included (mean age: 67.7±7.2 years and 36.6% male). Compared with PACS, higher crypt grade was significantly associated with lower odds of APAC (OR=0.58 for one grade higher in crypt grade; p=0.027, adjusted for age, gender, ethnicity and pupil diameter). The results remained similar when compared with PAC/PACG group (OR=0.58 for one grade higher in crypt grade; p=0.043). We did not observe any significant associations between iris furrows or colour with presence of APAC. Our study comprising Asian eyes with angle closure suggests that the presence of a higher crypt grading may be protective for APAC. As such, assessing iris surface architecture for crypts could be a new measure for risk stratification of developing APAC in eyes with angle closure. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  9. Single-shell tank closure work plan. Revision A

    International Nuclear Information System (INIS)

    1995-06-01

    In January 1994, the Hanford Federal Facility Agreement and Conset Order (Tri-Party Agreement) was amended to reflect a revised strategy for remediation of radioactive waste in underground storage tanks. These amendments include milestones for closure of the single-shell tank (SST) operable units, to be initiated by March 2012 and completed by September 2024. This SST-CWP has been prepared to address the principal topical areas identified in Tri-Party Agreement Milestone M-45-06 (i.e., regulatory pathway, operable unit characterization, waste retrieval, technology development, and a strategy for achieving closure). Chapter 2.0 of this SST-CWP provides a brief description of the environmental setting, SST System, the origin and characteristics of SST waste, and ancillary equipment that will be remediated as part of SST operable unit closure. Appendix 2A provides a description of the hydrogeology of the Hanford Site, including information on the unsaturated sediments (vadose zone) beneath the 200 Areas Plateau. Chapter 3.0 provides a discussion of the laws and regulations applicable to closure of the SST farm operable units. Chapter 4.0 provides a summary description of the ongoing characterization activities that best align with the proposed regulatory pathway for closure. Chapter 5.0 describes aspects of the SST waste retrieval program, including retrieval strategy, technology, and sequence, potential tank leakage during retrieval, and considerations of deployment of subsurface barriers. Chapter 6.0 outlines a proposed strategy for closure. Chapter 7.0 provides a summary of the programs underway or planned to develop technologies to support closure. Ca. 325 refs

  10. Plateau iris in Japanese patients with primary angle closure and primary angle closure glaucoma

    Directory of Open Access Journals (Sweden)

    Mizoguchi T

    2015-06-01

    Full Text Available Takanori Mizoguchi,1 Mineo Ozaki,2,3 Harumi Wakiyama,1,4 Nobuchika Ogino1,51Mizoguchi Eye Clinic, Nagasaki, Japan; 2Ozaki Eye Clinic Miyazaki, Japan; 3Department of Ophthalmology, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan; 4The Japanese Red Cross Nagasaki Genbaku Hospital, Nagasaki, Japan; 5Nishigaki Eye Clinic, Nagoya, JapanPurpose: To determine the prevalence of plateau iris in Japanese patients with primary angle closure (PAC and primary angle closure glaucoma (PACG and analyze the biometric parameters in patients with plateau iris using ultrasound biomicroscopy (UBM.Methods: In this cross-sectional observational study, subjects aged >50 years with PAC and PACG who had previously undergone a patent laser peripheral iridotomy underwent UBM in one eye. UBM images were qualitatively analyzed using standardized criteria. Plateau iris in a quadrant was defined by anteriorly directed ciliary body, absent ciliary sulcus, steep iris root from its point of insertion followed by a downward angulation, flat iris plane, and irido-angle contact. At least two quadrants had to fulfill these UBM criteria for an eye to be classified as having plateau iris. A-scan biometry was used to measure anterior segment parameters.Results: Ninety-one subjects with PAC (58 subjects or PACG (33 subjects and 68 normal controls were recruited. The mean (standard deviation ages of PAC and PACG patients and normal controls were 73.5 (6.2 and 72.6 (7.3, respectively. Based on UBM criteria, plateau iris was found in 16 eyes (17.6% of 91 eyes. In these 16 eyes, quadrant-wise analysis showed ten eyes (62.5% had plateau iris in two quadrants; four eyes (25% had plateau iris in three quadrants; and two eyes (12.5% had plateau iris in four quadrants. Anterior chamber depth, lens thickness, axial length, lens position, and relative lens position were not statistically significant between the group having plateau iris and that not having plateau iris

  11. Fusion measurements for the {}^{18}O+{}^{194}{Pt} reaction and search for neutron shell closure effects

    Science.gov (United States)

    Laveen, P. V.; Prasad, E.; Madhavan, N.; Pal, S.; Sadhukhan, J.; Nath, S.; Gehlot, J.; Jhingan, A.; Varier, K. M.; Thomas, R. G.; Vinodkumar, A. M.; Shamlath, A.; Varughese, T.; Sugathan, P.; Babu, B. R. S.; Appannababu, S.; Golda, K. S.; Behera, B. R.; Singh, Varinderjit; Sandal, Rohit; Saxena, A.; John, B. V.; Kailas, S.

    2015-09-01

    Evaporation residue (ER) and fission cross sections were measured for the reaction {}18O+{}194{Pt} forming the compound nucleus 212Rn. Fission fragment angular distributions and anisotropies are consistent with the saddle point model predictions. Measured ER cross sections were fitted with statistical model calculations assuming shell-corrected free energy fission barrier height. The non-zero dissipation strength required to fit the ER cross section supports the dissipative nature of fission dynamics in heavy ion fusion. In the present study shell closure effects are not observed in the dissipation strength.

  12. Protecting an island nation from extreme pandemic threats: Proof-of-concept around border closure as an intervention.

    Directory of Open Access Journals (Sweden)

    Matt Boyd

    Full Text Available Countries are well advised to prepare for future pandemic risks (e.g., pandemic influenza, novel emerging agents or synthetic bioweapons. These preparations do not typically include planning for complete border closure. Even though border closure may not be instituted in time, and can fail, there might still plausible chances of success for well organized island nations.To estimate costs and benefits of complete border closure in response to new pandemic threats, at an initial proof-of-concept level. New Zealand was used as a case-study for an island country.An Excel spreadsheet model was developed to estimate costs and benefits. Case-study specific epidemiological data was sourced from past influenza pandemics. Country-specific healthcare cost data, valuation of life, and lost tourism revenue were imputed (with lost trade also in scenario analyses.For a new pandemic equivalent to the 1918 influenza pandemic (albeit with half the mortality rate, "Scenario A", it was estimated that successful border closure for 26 weeks provided a net societal benefit (e.g., of NZ$11.0 billion, USD$7.3 billion. Even in the face of a complete end to trade, a net benefit was estimated for scenarios where the mortality rate was high (e.g., at 10 times the mortality impact of "Scenario A", or 2.75% of the country's population dying giving a net benefit of NZ$54 billion (USD$36 billion. But for some other pandemic scenarios where trade ceased, border closure resulted in a net negative societal value (e.g., for "Scenario A" times three for 26 weeks of border closure-but not for only 12 weeks of closure when it would still be beneficial.This "proof-of-concept" work indicates that more detailed cost-benefit analysis of border closure in very severe pandemic situations for some island nations is probably warranted, as this course of action might sometimes be worthwhile from a societal perspective.

  13. Decontamination and inspection plan for phase 2 closure of the 300 Area waste acid treatment system

    International Nuclear Information System (INIS)

    Hays, C.B.

    1998-01-01

    This decontamination and inspection plan (DIP) describes decontamination and verification activities in support of Phase 2 closure of the 300 Area Waste Acid Treatment System (WATS). Phase 2, the second phase of three proposed phases of closure for WATS, provides for closure of all WATS portions of the 334-A Building and some, but not all, WATS portions of the 333 and 303-F Buildings. Closure of the entire unit will not occur until all three closure phases have been completed. The DIP also describes the designation and management-process for waste and debris generated during Phase 2 closure activities. Information regarding the decontamination and verification methods for Phase 1 closure can be found in Decontamination and Inspection Plan, for Phase 1 closure of the 300 Area Waste Acid Treatment System, 21 WHC-SD-ENV-AP-001. Information regarding Phase 3 closure will be provided in later documents

  14. Cutaneous wound closure materials: An overview and update

    Directory of Open Access Journals (Sweden)

    Luluah Al-Mubarak

    2013-01-01

    Full Text Available Introduction: On a daily basis, dermasurgeons are faced with different kinds of wounds that have to be closed. With a plethora of skin closure materials currently available, choosing a solution that combines excellent and rapid cosmetic results with practicality and cost-effectiveness can be difficult, if not tricky. Objectives: We aimed to review the available skin closure materials over the past 20 years and the scientific claims behind their effectiveness in repairing various kinds of wounds. Materials and Methods: The two authors independently searched and scrutinised the literature. The search was performed electronically using Pub Med, the Cochrane Database, Google Scholar and Ovid as search engines to find articles concerning skin closure materials written since 1990. Conclusion: Many factors are involved in the choice of skin closure material, including the type and place of the wound, available materials, physician expertise and preferences, and patient age and health. Evidence-based main uses of different skin closure materials are provided to help surgeons choose the appropriate material for different wounds.

  15. Citalopram associated with acute angle-closure glaucoma: case report

    Directory of Open Access Journals (Sweden)

    Hassan Sabit

    2005-10-01

    Full Text Available Abstract Background Acute angle-closure glaucoma is a rare complication in patients receiving anti-depressant treatment. In the following case, we report the development of acute angle closure glaucoma in a patient who overdosed on Citalopram, an antidepressant, and discuss the possible etiological mechanisms for the condition. Case presentation We report a 54 year old, Caucasian lady, with depression and alcohol dependence syndrome, who developed acute angle-closure glaucoma after an overdose of Citalopram, along with alcohol. She was treated with medications and had bilateral Yag laser iridotomies to correct the glaucoma and has made complete recovery. In this case, the underlying cause for glaucoma appears to be related to the ingestion of Citalopram. Conclusion The patho-physiological basis for acute angle closure glaucoma in relation to antidepressant medications remains unclear. The authors suggest Citalopram may have a direct action on the Iris or Ciliary body muscle through serotonergic or anti-cholinergic mechanisms or both. This case highlights the importance of the awareness of the underlying risks, which may predispose an individual to develop acute angle-closure glaucoma, and reminds the clinicians the significance of history taking and examination of the eye before and after starting anti-depressants. This area needs to be further researched.

  16. Effectiveness of percutaneous closure of patent foramen ovale for hypoxemia.

    Science.gov (United States)

    Fenster, Brett E; Nguyen, Bryant H; Buckner, J Kern; Freeman, Andrew M; Carroll, John D

    2013-10-15

    The aim of this study was to evaluate the ability of percutaneous patent foramen ovale (PFO) closure to improve systemic hypoxemia. Although PFO-mediated right-to-left shunt (RTLS) is associated with hypoxemia, the ability of percutaneous closure to ameliorate hypoxemia is unknown. Between 2004 and 2009, 97 patients who underwent PFO closure for systemic hypoxemia and dyspnea that was disproportionate to underlying lung disease were included for evaluation. All patients exhibited PFO-mediated RTLS as determined by agitated saline echocardiography. Procedural success was defined as implantation of a device without major complications and mild or no residual shunt at 6 months. Clinical success was defined as a composite of an improvement in New York Heart Association (NYHA) functional class, reduction of dyspnea symptoms, or decreased oxygen requirement. Procedural success was achieved in 96 of 97 (99%), and clinical success was achieved in 68 of 97 (70%). The presence of any moderate or severe interatrial shunt by agitated saline study (odds ratio [OR] = 4.7; p gender (OR = 0.30; p <0.017) decreased the likelihood of success. In conclusion, based on the largest single-center experience of patients referred for PFO closure for systemic hypoxemia, PFO closure was a mechanically effective procedure with an associated improvement in echocardiographic evidence of RTLS, NYHA functional class, and oxygen requirement. Copyright © 2013 Elsevier Inc. All rights reserved.

  17. Interatrial shunt closure devices in patients with nickel allergy.

    Science.gov (United States)

    Reddy, Bhavananda T; Patel, Jeetendra B; Powell, Douglas L; Michaels, Andrew D

    2009-10-01

    We assessed outcomes in nickel allergic patients treated with percutaneous interatrial shunt device closure with the Helex device. Nickel toxicity has been well described in patients undergoing interatrial shunt closure with the Amplatzer device, which has a nitinol design. There have been no reports using Helex in nickel allergic patients. Ninety-five consecutive patients underwent percutaneous interatrial shunt closure at a single US center by one operator. In those with possible nickel allergy, patch testing with the North American Contact Dermatitis Group standard series and a metal series was performed. The mean age was 48 +/- 16 years (range 18-81), 48% were male, 21 (22%) had atrial septal defect, and 74 (78%) had patent foramen ovale. Six patients had a positive skin test to nickel and underwent successful closure with Helex. Of the remaining 89 patients, 88 were closed with Amplatzer and one with Helex. All procedures were successful with no deaths, myocardial infarctions, strokes, or systemic emboli at six-month followup. None of the Helex patients developed an allergic reaction, significant chest pain, or arrhythmia. Of those without pre-procedural known nickel allergy, 12% had palpitations, 5% had atrial fibrillation, and 13% had chest pain. When compared with a published report that 89% of nickel-allergic patients developing an allergic reaction to the Amplatzer or Premere device, Helex appeared far safer in nickel allergic patients (P nickel allergy, percutaneous interatrial shunt device closure with Helex device is safe, and is not associated with allergy to nickel.

  18. Cutaneous wound closure materials: an overview and update.

    Science.gov (United States)

    Al-Mubarak, Luluah; Al-Haddab, Mohammed

    2013-10-01

    On a daily basis, dermasurgeons are faced with different kinds of wounds that have to be closed. With a plethora of skin closure materials currently available, choosing a solution that combines excellent and rapid cosmetic results with practicality and cost-effectiveness can be difficult, if not tricky. We aimed to review the available skin closure materials over the past 20 years and the scientific claims behind their effectiveness in repairing various kinds of wounds. The two authors independently searched and scrutinised the literature. The search was performed electronically using Pub Med, the Cochrane Database, Google Scholar and Ovid as search engines to find articles concerning skin closure materials written since 1990. Many factors are involved in the choice of skin closure material, including the type and place of the wound, available materials, physician expertise and preferences, and patient age and health. Evidence-based main uses of different skin closure materials are provided to help surgeons choose the appropriate material for different wounds.

  19. Plateau iris in Japanese patients with primary angle closure and primary angle closure glaucoma.

    Science.gov (United States)

    Mizoguchi, Takanori; Ozaki, Mineo; Wakiyama, Harumi; Ogino, Nobuchika

    2015-01-01

    To determine the prevalence of plateau iris in Japanese patients with primary angle closure (PAC) and primary angle closure glaucoma (PACG) and analyze the biometric parameters in patients with plateau iris using ultrasound biomicroscopy (UBM). In this cross-sectional observational study, subjects aged >50 years with PAC and PACG who had previously undergone a patent laser peripheral iridotomy underwent UBM in one eye. UBM images were qualitatively analyzed using standardized criteria. Plateau iris in a quadrant was defined by anteriorly directed ciliary body, absent ciliary sulcus, steep iris root from its point of insertion followed by a downward angulation, flat iris plane, and irido-angle contact. At least two quadrants had to fulfill these UBM criteria for an eye to be classified as having plateau iris. A-scan biometry was used to measure anterior segment parameters. Ninety-one subjects with PAC (58 subjects) or PACG (33 subjects) and 68 normal controls were recruited. The mean (standard deviation) ages of PAC and PACG patients and normal controls were 73.5 (6.2) and 72.6 (7.3), respectively. Based on UBM criteria, plateau iris was found in 16 eyes (17.6%) of 91 eyes. In these 16 eyes, quadrant-wise analysis showed ten eyes (62.5%) had plateau iris in two quadrants; four eyes (25%) had plateau iris in three quadrants; and two eyes (12.5%) had plateau iris in four quadrants. Anterior chamber depth, lens thickness, axial length, lens position, and relative lens position were not statistically significant between the group having plateau iris and that not having plateau iris, respectively. Approximately 20% of Japanese subjects with PAC and PACG with a patent laser peripheral iridotomy were found to have plateau iris on UBM. No morphological difference was noted in the anterior segment of the eye between those with or without plateau iris.

  20. Closure versus non-closure of the peritoneum at caesarean section: short- and long-term outcomes.

    Science.gov (United States)

    Bamigboye, Anthony A; Hofmeyr, G Justus

    2014-08-11

    Caesarean section is a very common surgical procedure worldwide. Suturing the peritoneal layers at caesarean section may or may not confer benefit, hence the need to evaluate whether this step should be omitted or routinely performed. The objective of this review was to assess the effects of non-closure as an alternative to closure of the peritoneum at caesarean section on intraoperative and immediate- and long-term postoperative outcomes. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (1 November 2013). Randomised controlled trials comparing leaving the visceral or parietal peritoneum, or both, unsutured at caesarean section with a technique which involves suturing the peritoneum in women undergoing elective or emergency caesarean section. Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked it for accuracy. A total of 29 trials were included in this review and 21 trials (17,276 women) provided data that could be included in an analysis. The quality of the trials was variable. 1. Non-closure of visceral and parietal peritoneum versus closure of both parietal layersSixteen trials involving 15,480 women, were included and analysed, when both parietal peritoneum was left unclosed versus when both peritoneal surfaces were closed. Postoperative adhesion formation was assessed in only four trials with 282 women, and no difference was found between groups (risk ratio (RR) 0.99, 95% confidence interval (CI) 0.76 to 1.29). There was significant reduction in the operative time (mean difference (MD) -5.81 minutes, 95% CI -7.68 to -3.93). The duration of hospital stay in a total of 13 trials involving 14,906 women, was also reduced (MD -0.26, 95% CI -0.47 to -0.05) days. In a trial involving 112 women, reduced chronic pelvic pain was found in the peritoneal non-closure group. 2. Non-closure of visceral peritoneum only versus closure of both peritoneal surfacesThree trials involving 889 women

  1. Procedures and techniques for closure of near surface disposal facilities for radioactive waste

    International Nuclear Information System (INIS)

    2001-12-01

    The overall objective of this report is to provide Member States with guidance on planning and implementation of closure of near surface disposal facilities for low and intermediate level radioactive waste. The specific objectives are to review closure concepts, requirements, and components of closure systems; to discuss issues and approaches to closure, including regulatory, economic, and technical aspects; and to present major examples of closure techniques used and/or considered by Member States. Some examples of closure experience from Member States are presented in the Appendix and were indexed separately

  2. The 300 area waste acid treatment system closure plan

    International Nuclear Information System (INIS)

    Luke, S.N.

    1996-01-01

    The 300 Area Waste Acid Treatment System (WATS) is located within operable units 300-FF-2 (source) and 300-FF-5 (groundwater), as designated in the Hanford Federal Facility Agreement and Consent Order (Tri-Party Agreement) . Operable units 300-FF-2 and 300-FF-5 are scheduled to be remediated using the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) Remedial Investigation/Feasibility Study (RI/FS) process. Thus, any remediation of the 300 Area WATS with respect to contaminants not produced by those facilities and soils and groundwater will be deferred to the CERCLA RI/FS process. Final closure activities will be completed in 3 phases and certified in accordance with the 300 Area WATS closure plan by the Washington State Department of Ecology (Ecology) and the U.S. Environmental Protection Agency (EPA). It is anticipated that the 300 Area WATS closure would take 2 years to complete

  3. INTEC CPP-603 Basin Water Treatment System Closure: Process Design

    Energy Technology Data Exchange (ETDEWEB)

    Kimmitt, Raymond Rodney; Faultersack, Wendell Gale; Foster, Jonathan Kay; Berry, Stephen Michael

    2002-09-01

    This document describes the engineering activities that have been completed in support of the closure plan for the Idaho Nuclear Technology and Engineering Center (INTEC) CPP-603 Basin Water Treatment System. This effort includes detailed assessments of methods and equipment for performing work in four areas: 1. A cold (nonradioactive) mockup system for testing equipment and procedures for vessel cleanout and vessel demolition. 2. Cleanout of process vessels to meet standards identified in the closure plan. 3. Dismantlement and removal of vessels, should it not be possible to clean them to required standards in the closure plan. 4. Cleanout or removal of pipelines and pumps associated with the CPP-603 basin water treatment system. Cleanout standards for the pipes will be the same as those used for the process vessels.

  4. Evaluating the urethral closure mechanism after pelvic organ prolapse surgery

    DEFF Research Database (Denmark)

    Khayyami, Yasmine

    2017-01-01

    , the woman has occult SUI. However, only half of all women with occult SUI actually develop de novo SUI postoperatively and therefore, the usefulness of the test has been questioned. Studies investigating how POP reduction and POP surgery affect the urethral closure mechanism have used conventional urethral...... pressure profilometry, a method that has shown wide overlaps in the results of women with and without SUI. Urethral pressure reflectometry (UPR), a method that assesses the urethral closure mechanism by means of acoustic reflectometry, has proven highly reproducible in women with and without SUI....... By measuring urethral opening pressure at an abdominal pressure of 50 mmH2O (PO-Abd 50), it is the only method that has succeeded in distinguishing between women with and without SUI. The overall aim of this thesis was to evaluate the urethral closure mechanism before and after anterior and posterior...

  5. Space closure using the Hycon device. A case report.

    Science.gov (United States)

    Kachiwala, Viral A; Kalha, Anmol S; Vigneshwaran, J

    2007-05-01

    Space closure can be a difficult and uncomfortable procedure. Appliances able to be activated by the patient may reduce the number of visits for adjustment. To describe the closure of spaces with the Hycon device, an intra-oral screw that can be activated by the patient. Sliding mechanics were used to retract the upper and lower anterior teeth following extraction of the first premolars in a patient with bimaxillary protrusion. The active force for retraction was derived from the Hycon device activated twice a week by the patient. The rate of space closure achieved was of the order of 1.9 mm/month. The extraction spaces were closed by distal movement of the anterior teeth and mesial movement of the posterior teeth. The Hycon device proved to be an effective means of retracting the anterior teeth and protracting the posterior teeth. Because the device can be activated by the patient fewer visits for adjustment may be required.

  6. Overlay Technique for Transcatheter Left Atrial Appendage Closure.

    Science.gov (United States)

    Li, Shuang; Zhu, Mengyun; Lu, Yunlan; Tang, Kai; Zhao, Dongdong; Chen, Wei; Xu, Yawei

    2015-08-01

    The Overlay technique is popular in peripheral artery interventions, but not in coronary or cardiac structural procedures. We present an initial experience using three-episode overlays during a transcatheter left atrial appendage closure. The first overlay was applied to facilitate advancement of the delivery sheath into left atrium. The second overlay was used to navigate the advancement of prepped delivery system containing the compressed occluder into its optimal position in the left atrium. The third overlay facilitated the real-time deployment of the closure device. This case report demonstrates the effectiveness of the overlay technique in facilitating each step of the transcatheter left atrial appendage closure. Copyright © 2015 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

  7. Bilateral Acute Angle-closure after Intraocular Surgery.

    Science.gov (United States)

    Hoskens, Kirsten; Pinto, Luis Abegão; Vandewalle, Evelien; Verdonk, Nancy; Stalmans, Ingeborg

    2014-01-01

    We report the case of a 75-year-old woman who developed an acute bilateral angle-closure associated with choroidal effusion a day after an uneventful cataract surgery. The same patient had undergone a similarly uneventful cataract surgery two weeks before, under the same protocol, with no postoperative complication in the other eye. Medical treatment, including the use of oral sulfamide-related drugs (acetazolamide), topical beta-blockers and steroids led to a gradual decrease in intraocular pressure (IOP) and choroidal effusion. Despite initial reports suggesting a link between sulfamide-exposure and these rare forms of angle-closure, our report would suggest a more complex pathophysiology behind this intriguing phenomenon. How to cite this article: Hoskens K, Pinto LA, Vandewalle E, Verdonk N, Stalmans I. Bilateral Acute Angle-closure after Intraocular Surgery. J Curr Glaucoma Pract 2014;8(3):113-114.

  8. Closure versus non-closure of the visceral peritoneum (VP) in patients with gestational hypertension--an observational analysis.

    Science.gov (United States)

    Malvasi, Antonio; Tinelli, Andrea; Hudelist, Gernot; Vergara, Daniele; Martignago, Roberta; Tinelli, Raffaele

    2009-01-01

    Caesarean section (CS) is one of the most frequently performed surgical procedures worldwide. Surgical variants include closure and non-closure of the peritoneum: in case of non-suturing the visceral peritoneum (VP), abnormal fluid collections such as blood clots may lead to formation of a hematoperitoneum. In this retrospective, observational study we reviewed 1848 patients with gestational hypertension (GH) undergoing repeat and primary CS performed by non-closure of the visceral peritoneum (VP). Six of these patients had major early post-CS complications: 5 patients experienced hypovolaemic shock that required urgent operative intervention. Four patients underwent repeat laparotomy and one patient was treated by laparoscopy. As an early major post-CS complication, hematoperitoneum occurs in cases with poor haemostasis and/or with haemodynamic disorders such as GH. A decrease in blood pressure (BP) during CS caused by spinal/epidural anaesthesia and the following BP increase in GH patients may favour bleeding complications. Closure of the VP may facilitate early detection of a subperitoneal hematoma. In contrast, hematoperitoneum may develop in cases of non-closure of the VP followed by hypovolemic shock. Early and aggressive intervention results in excellent prognosis of this complication.

  9. A Multi-Fidelity Surrogate Model for Handling Real Gas Equations of State

    Science.gov (United States)

    Ouellet, Frederick; Park, Chanyoung; Rollin, Bertrand; Balachandar, S."bala"

    2016-11-01

    The explosive dispersal of particles is an example of a complex multiphase and multi-species fluid flow problem. This problem has many engineering applications including particle-laden explosives. In these flows, the detonation products of the explosive cannot be treated as a perfect gas so a real gas equation of state is used to close the governing equations (unlike air, which uses the ideal gas equation for closure). As the products expand outward from the detonation point, they mix with ambient air and create a mixing region where both of the state equations must be satisfied. One of the more accurate, yet computationally expensive, methods to deal with this is a scheme that iterates between the two equations of state until pressure and thermal equilibrium are achieved inside of each computational cell. This work strives to create a multi-fidelity surrogate model of this process. We then study the performance of the model with respect to the iterative method by performing both gas-only and particle laden flow simulations using an Eulerian-Lagrangian approach with a finite volume code. Specifically, the model's (i) computational speed, (ii) memory requirements and (iii) computational accuracy are analyzed to show the benefits of this novel modeling approach. This work was supported by the U.S. Department of Energy, National Nuclear Security Administration, Advanced Simulation and Computing Program, as a Cooperative Agreement under the Predictive Science Academic Alliance Program, under Contract No. DE-NA00023.

  10. Closure certification report: TA-35 TSL-125 surface impoundment

    International Nuclear Information System (INIS)

    1991-01-01

    This closure report documents closure activities for the TA-35 TSL-125 surface impoundment and associated structures at Los Alamos National Laboratory (the Laboratory). Prior to formal approval of the closure plan, the decision was made to proceed with closure activities to prevent any further releases from the site following informal discussions with New Mexico Environment Department (NMED) personnel. The closure plan is a revision of the previously submitted draft dated July 1988. Clean closure of the TSL-125 site was accomplished through: Removal and proper disposal of all wastes contained within the surface impoundment system; Decontamination and/or removal and proper disposal of the surface impoundment, its associated structures, and contaminated soil underlying the impoundment area; Sampling and analysis of soil to determine the presence and concentrations of any hazardous constituents remaining in the soil at the TSL-125 site; and Demonstration through a risk assessment that any constituents remaining in the soil at the TSL-125 site pose no threat to human health and the environment. All remaining soil concentrations of hazardous constituents were below health-based action levels. Analytical results indicated that benzidine, n-nitrosodimethylamine, and n-nitrosodi-n-propylamine were not detected at or above their limits of quantitation and beryllium was not present at or above its laboratory detection limit. However, the limits of quantitation and detection for these constituents were greater than their calculated health-based action levels. To demonstrate that these constituents were not present, historical data was researched and it was determined that the constituents were not utilized at the Building 125 site. 4 refs., 8 figs., 1 tab

  11. Nickel allergy in interatrial shunt device-based closure patients.

    Science.gov (United States)

    Rigatelli, Gianluca; Cardaioli, Paolo; Giordan, Massimo; Aggio, Silvio; Chinaglia, Mauro; Braggion, Gabriele; Roncon, Loris

    2007-01-01

    The possibility of nickel toxicity has been raised with interatrial shunt closure devices constructed of nitinol. This study is aimed to assess the potential adverse symptoms in terms of incidence, duration, and significance, in patients with interatrial shunt and nickel allergy who underwent nitinol device-based closure. We prospectively enrolled 46 consecutive patients (mean age 35 +/- 28.8 years, 30 female) over a 12-month period referred to our center for catheter-based closure of interatrial shunts. Patients were investigated for previous hypersensivity to nickel and were required to test potential nickel allergy with cutaneous patch test (TRUE test) before device implantation. Routinely, clinical visit with laboratory examinations, and TTE were scheduled at 1, 6, and 12 months. Nine patients (19.5%, mean age 31.3 +/- 13.2 years) had proved symptomatic and instrumental nickel allergy as showed by cutaneous patch skin test but preferred to be implanted. All patients underwent successful transcatheter closure with an immediate occlusion rate of 100% without intraoperative complications. Between the 2nd and 3rd postoperative day, 8 out of 9 patients developed a sort of 'device syndrome' that included concurrent chest discomfort, exertional dyspnea and asthenia, and mild leukocytosis. The syndrome was treated with Prednison and Clopidogrel and in all was resolved after 1-week therapy. Interestingly, none of the patients without nickel allergy developed postclosure symptoms (P nickel allergy is still a problematic issue in patients scheduled for transcatheter closure of intracardiac shunts; however, our brief study suggests that nickel allergy is not per se a contraindication to nitinol device closure.

  12. Safety Outcomes After Percutaneous Transcatheter Closure of Patent Foramen Ovale.

    Science.gov (United States)

    Merkler, Alexander E; Gialdini, Gino; Yaghi, Shadi; Okin, Peter M; Iadecola, Costantino; Navi, Babak B; Kamel, Hooman

    2017-11-01

    We sought to evaluate the real-world rate of safety outcomes after patent foramen ovale (PFO) closure in patients with ischemic stroke or transient ischemic attack (TIA). We performed a retrospective cohort study using administrative claims data on all hospitalizations from 2005 to 2013 in New York, California, and Florida. Using International Classification of Diseases, Ninth Revision, Clinical Modification codes, we identified patients who underwent percutaneous transcatheter PFO closure within 1 year of ischemic stroke or TIA. Our outcome was an adverse event occurring during the hospitalization for PFO closure, defined as in prior studies as atrial fibrillation or flutter, cardiac tamponade, pneumothorax, hemothorax, a vascular access complication, or death. Crude rates were reported with exact confidence intervals. We identified 1887 patients who underwent PFO closure after ischemic stroke or TIA. The rate of any adverse outcome during the hospitalization for PFO closure was 7.0% (95% confidence interval [CI], 5.9%-8.2%). Rates of adverse outcomes varied by age and type of preceding cerebrovascular event. In patients >60 years of age, the rate of adverse outcomes was 10.9% (95% CI, 8.6%-13.6%) versus 4.9% (95% CI, 3.8%-6.3%) in patients ≤60 years of age. The rate of adverse outcomes was 9.9% (95% CI, 7.3%-12.5%) in patients with preceding ischemic stroke versus 5.9% (95% CI, 4.7%-7.1%) after TIA. Approximately 1 in 14 patients who underwent percutaneous transcatheter PFO closure after ischemic stroke or TIA experienced a serious periprocedural adverse outcome or death. The risk of adverse outcomes was highest in older patients and in those with preceding ischemic stroke. © 2017 American Heart Association, Inc.

  13. Nitric oxide in guard cells as an important secondary messenger during stomatal closure

    Directory of Open Access Journals (Sweden)

    Gunja eGayatri

    2013-10-01

    Full Text Available he modulation of guard cell function is the basis of stomatal closure, essential for optimizing water use and CO2 uptake by leaves. Nitric oxide (NO in guard cells plays a very important role as a secondary messenger during stomatal closure induced by effectors, including hormones. For example, exposure to abscisic acid (ABA triggers a marked increase in NO of guard cells, well before stomatal closure. In guard cells of multiple species, like Arabidopsis, Vicia and pea, exposure to ABA or methyl jasmonate or even microbial elicitors (e.g. chitosan induces production of NO as well as reactive oxygen species (ROS. The role of NO in stomatal closure has been confirmed by using NO donors (e.g. SNP and NO scavengers (like cPTIO and inhibitors of NOS (L-NAME or NR (tungstate. Two enzymes: a L-NAME-sensitive, nitric oxide synthase (NOS-like enzyme and a tungstate-sensitive nitrate reductase (NR, can mediate ABA-induced NO rise in guard cells. However, the existence of true NOS in plant tissues and its role in guard cell NO-production are still a matter of intense debate. Guard cell signal transduction leading to stomatal closure involves the participation of several components, besides NO, such as cytosolic pH, ROS, free Ca2+ and phospholipids. Use of fluorescent dyes has revealed that the rise in NO of guard cells occurs after the increase in cytoplasmic pH and ROS. The rise in NO causes an elevation in cytosolic free Ca2+ and promotes the efflux of cations as well as anions from guard cells. Stomatal guard cells have become a model system to study the signalling cascade mechanisms in plants, particularly with NO as a dominant component. The interrelationships and interactions of NO with cytosolic pH, ROS, and free Ca2+ are quite complex and need further detailed examination. While assessing critically the available literature, the present review projects possible areas of further work related to NO-action in stomatal guard cells.

  14. [Laser Iridotomy - In Cases of Acute Angle Closure Only?

    Science.gov (United States)

    Handzel, Daniel M; Meyer, Carsten H; Wegener, Alfred

    2017-11-01

    The narrowing of the chamber angle-as a result of anatomic predispositions like high hyperopia or increasing lens thickness-poses the greatest risk for acute angle closure. A laser iridotomy counts as a standard procedure in cases of acute angle closure, whereas there are no coherent recommendations or guidelines for a prophylactic therapy. Modern imaging techniques, such as anterior segment optical coherence tomography or Scheimpflug photography, can give valuable information for the planning of treatment. This review presents traditional and modern imaging techniques and summarises recommendations for action in relation to recent publications. Georg Thieme Verlag KG Stuttgart · New York.

  15. Pulmonary edema following transcatheter closure of atrial septal defect

    Directory of Open Access Journals (Sweden)

    Keerthi Chigurupati

    2015-01-01

    Full Text Available We describe an incident of development of acute pulmonary edema after the device closure of a secundum atrial septal defect in a 52-year-old lady, which was treated with inotropes, diuretics and artificial ventilation. Possibility of acute left ventricular dysfunction should be considered after the defect closure in the middle-aged patients as the left ventricular compliance may be reduced due to increased elastic stiffness and diastolic dysfunction. Baseline left atrial pressure may be > 10 mmHg in these patients. Associated risk factors for the left ventricular dysfunction are a large Qp:Qs ratio, systemic hypertension, severe pulmonary hypertension and paroxysmal atrial fibrillation.

  16. Closure Plan for Active Low Level Burial Grounds

    Energy Technology Data Exchange (ETDEWEB)

    SKELLY, W.A.

    2000-11-16

    This plan has been prepared in response to direction from the U.S. Department of Energy. The purpose of the plan is to define approaches that will be implemented to ensure protection of the public and the environment when active Low-Level Burial Grounds (LLBGs) at the Hanford Site are closed. Performance assessments for active burial grounds in the 200 East and West 200 Areas provide current estimates of potential environmental contamination and doses to the ''maximum exposed individual'' from burial ground operation and closure and compare dose estimates to performance objective dose limits for the facilities. This is an Operational Closure Plan. The intent of the guidance in DOE Order 435.1 is that this plan will be a living document, like the facility performance assessments, and will be revised periodically through the operational life of the LLBGs to reflect updated information on waste inventory. management practices, facility transition planning, schedule dates, assessments of post-closure performance, and environmental consequences. Out year dates identified in this plan are tentative. A Final Closure Plan will be prepared in the future when the timing and extent of closure-related activities for LLBGs can be established with greater certainty. After current operations at the LLBGs are concluded, this plan proposes transitioning of these facilities to the Environmental Restoration Program. This action will enable the Environmental Restoration Program to design and implement consistent and coordinated final remedial actions for active and inactive LLBGs. Active and inactive burial grounds in the 200 West and 200 East Areas are commingled. This plan describes approaches that will be implemented during Interim Closure, Final Closure, and Institutional Control Periods to prepare LLBGs for surface barriers, and the construction of barriers, as well as the scope of inspection, monitoring and maintenance practices that will be performed during

  17. Jet schemes of the closure of nilpotent orbits

    OpenAIRE

    Moreau, Anne; Yu, Rupert W. T.

    2014-01-01

    39 pages in English. Final version, to appear in Pacific J. of Math.; We study in this paper the jet schemes of the closure of nilpotent orbits in a finite-dimensional complex reductive Lie algebra. For the nilpotent cone, which is the closure of the regular nilpotent orbit, all the jet schemes are irreducible. This was first observed by Eisenbud and Frenkel, and follows from a strong result of Musta ˘ t (2001). Using induction and restriction of "little" nilpotent orbits in reductive Lie alg...

  18. Transcatheter closure of Patent Ductus Arteriosus through only venous route.

    Science.gov (United States)

    Sheikh, Abdul Malik; Duke, Abdul Karim; Sattar, Hina

    2018-03-01

    Patent ductus arteriosus is a common congenital cardiac defect comprising 5-10% of all these defects in term neonates. Although open chest and video-assisted interruption are still in use, transcatheter occlusion has rapidly become the first choice for patent ductus arteriosus closure in the appropriate patient. Percutaneous closure of patent ductus arteriosus is widely done by transvenous approach guided by aortic access. We present the case of a 2 year old girl who underwent patent ductus arteriosus device occlusion with transvenous access only.

  19. Total System Performance Assessment- License Appication Design Selection (LADS) Phase 1 Analysis for Post-Closure Ventilation (Design Alternative 3)

    Energy Technology Data Exchange (ETDEWEB)

    N. Erb

    1999-06-21

    The objective of this report is to evaluate the effect of potential changes to the TSPA-VA base case design on long-term repository performance. The design changes that are evaluated in this report include two configurations for post-closure ventilation. bow tie and open loop (Design Alternative 3 or D3). The following paragraphs briefly describe the motivation for evaluating post-closure ventilation. The bow tie configuration for post closure ventilation has been identified as a design alternative to the TSPA-VA base case model (CRWMS M&O, 1998a) that may provide improved performance by reducing the temperature and relative humidity within the waste package drifts. The bow tie configuration for post-closure ventilation is a closed-loop design. In this design. cross drifts are placed in pairs with each drift angling up on opposite sides of the repository. From the side, the cross drifts and side drifts form the shape of a bow tie. Movement of air through the system is driven by convective heating from the waste packages in the cross drifts. The open loop configuration is also being considered for its potential to improve post-closure performance of the repository. As with the bow tie configuration, the open loop is designed to decrease temperature and relative humidity within the waste package drifts. For the open loop configuration, air is drawn into the drifts from outside the mountain. The configuration for the repository with open-loop ventilation is similar to the base case repository design with a few added shafts to increase air flow through the drifts. This report documents the modeling assumptions and calculations conducted to evaluate the long-term performance of Design Alternative 3. The performance measure for this evaluation is dose rate. Results are presented that compare the dose-rate time histories with the new design alternatives to that for the TSPA-VA base case calculation (CRWMS M&O, 1998a).

  20. Novi Han Radioactive Waste Repository post-closure safety assessment, ver.2

    International Nuclear Information System (INIS)

    Mateeva, M.

    2003-01-01

    The methodology for the post-closure safety assessment is presented. The assessment context includes regulatory framework (protection principles); scope and time frame; radiological and technical requirements; modeling etc. The description of the Novi Han disposal system contains site location. meteorological, hydrological and seismological characteristics; waste and repository description and human activities characteristics. The next step in the methodology is scenario development and justification. The systematic generation os exposure scenarios is considered as central to the post-closure safety assessment. The most important requirements for the systematic scenario generation approach are: transparency, comprehensiveness (all possible FEPs influencing the the disposal system and the radionuclide release should be considered); relevant future evolutions; identification of critical issues and investigation of the robustness of the system. For the source-pathway-receptor analysis the Process System is divided into near-field, geosphere/atmosphere and biosphere, describing the key facets controlling the potential radionuclide migration to the environment. The schematic division of the Novi Han near-field Process System into lower-level conceptual features is presented and discussed. As a result of the examinations of the FEPs three classes of scenarios are identified for the Novi Han post-closure safety assessment: Environmental evolution scenarios (geological change and climate change); future human action scenarios (human intrusion and archaeological action); Scenarios with very low probability (terrorism, crashes, explosions). The safety assessment iteration leads to identification of a modern scenario generation approach, assessment of key radionuclide releases, geological and hydrological evaluation, identification of the key parameters from sensitivity analysis etc. Examples of conceptual models are given. For the mathematical modeling the AMBER code is used